bluuebunny/crossref_metadata_2025 huggingface dataset:
An Africa point of view on quality and safety in imaging
Authors: Kawooya Michael G. , Kisembo Harriet Nalubega , Remedios Denis , Malumba Richard , del Rosario Perez Maria , Ige Taofeeq , Hasford Francis , Brown Joanna Kasznia , Lette Miriam Mikhail , Mansouri Boudjema , Salama Dina H. , Peer Fozy , Nyabanda Rose
Published: March 2022

Africa has seen an upsurge in diagnostic imaging utilization, with benefits of efficient and accurate diagnosis, but these could easily be offset by undesirable effects attributed to unjustified, unoptimized imaging and poor quality examinations. This paper aims to present Africa’s position regarding quality and safety in imaging, give reasons for the rising interest in quality and safety, define quality and safety from an African context, list drivers for quality and safety in Africa, discuss the impact of COVID-19 on quality and safety, and review Africa’s progress using the Bonn Call for Action framework while proposing a way forward for imaging quality and safety in Africa. In spite of a healthcare setting characterized by meagre financial, human and technology resources, a rapidly widening disease-burden spectrum, growing proportion of non-communicable diseases and resurgence of tropical and global infections, Africa has over the last ten years made significant strides in quality and safety for imaging. These include raising radiation-safety awareness, interest and application of evidence-based radiation safety recommendations and guidance tools, establishing facility and national diagnostic reference levels (DRLs) and strengthening end-user education and training. Major challenges are: limited human resource, low prioritization of imaging in relation to other health services, low level of integration of imaging into the entire health service delivery, insufficient awareness for radiation safety awareness, a radiation safety culture which is emerging, insufficient facilities and opportunities for education and training. Solutions to these challenges should target the entire hierarchy of health service delivery from prioritization, policy, planning, processes to procedures.
Euglycemic diabetic ketoacidosis induced by sodium-glucose cotransporter 2 inhibitor in the setting of prolonged fasting: a case report
Authors: Alkatheeri Abrar , Alseddeeqi Eiman
Published: March 2022

Background

We describe a case report of a patient with type 2 diabetes on sodium-glucose cotransporter 2 inhibitor and metformin therapy fasting for Ramadan (a holy month observed in the Islamic nation) diagnosed with euglycemic diabetic ketoacidosis.

Case presentation

The patient was a 51-year-old Moroccan male with history of type 2 diabetes mellitus on dapagliflozin and metformin. He presented with abdominal pain, vomiting, loss of appetite, and shortness of breath. He observed Ramadan month by fasting an average of 14 hours daily for 30 days. The patient was admitted with severe metabolic acidosis with a high anion gap and positive ketonuria in the setting of serum glucose of 13.5 mmol/L (243 mg/dL).

The patient was rehydrated and started on insulin infusion according to the diabetic ketoacidosis protocol following the diagnosis of euglycemic diabetic ketoacidosis.

Conclusion

Dapagliflozin is associated with euglycemic diabetic ketoacidosis in the setting of prolonged fasting. Counseling and possible medication adjustment should be added to clinical practice in those planning to decrease caloric intake through dedicated fasting including Ramadan or weight-loss-directed behavioral modifications, especially if taking sodium-glucose cotransporter 2 inhibitors.
A noninteger order SEITR dynamical model for TB
Authors: Panchal Jitendra , Acharya Falguni , Joshi Kanan
Published: March 2022

This research paper designs the noninteger order SEITR dynamical model in the Caputo sense for tuberculosis. The authors of the article have classified the infection compartment into four different compartments such as newly infected unrecognized individuals, diagnosed patients, highly infected patients, and patients with delays in treatment which provide better detail of the TB infection dynamic. We estimate the model parameters using the least square curve fitting and demonstrate that the proposed model provides a good fit to tuberculosis confirmed cases of India from the year 2000 to 2020. Further, we compute the basic reproduction number as$\Re _{0} \approx 1.73$ℜ0≈1.73of the model using the next-generation matrix method and the model equilibria. The existence and uniqueness of the approximate solution for the SEITR model is validated using the generalized Adams–Bashforth–Moulton method. The graphical representation of the fractional order model is given to validate the result using the numerical simulation. We conclude that the fractional order model is more realistic than the classical integer order model and provide more detailed information about the real data of the TB disease dynamics.
Antimicrobial stewardship in high-risk febrile neutropenia patients
Authors: Contejean Adrien , Abbara Salam , Chentouh Ryme , Alviset Sophie , Grignano Eric , Gastli Nabil , Casetta Anne , Willems Lise , Canouï Etienne , Charlier Caroline , Pène Frédéric , Charpentier Julien , Reboul-Marty Jeanne , Batista Rui , Bouscary Didier , Kernéis Solen
Published: March 2022

Background

The 2011 4th European Conference on Infections in Leukemia (ECIL4) guidelines recommend antibiotics de-escalation/discontinuation in selected febrile neutropenia (FN) patients. We aimed to assess the impact of an antimicrobial stewardship (AMS) program based on these guidelines on antibiotics use and clinical outcomes in high-risk FN patients.

Methods

We conducted an observational study in the hematology department of Cochin University Hospital in Paris, France. An ECIL4-based antibiotics de-escalation and discontinuation strategy was implemented jointly by the hematologists and the AMS team. The pre-intervention (January–October 2018) and post-intervention (January-October 2019) periods were compared. We retrospectively collected clinical and microbiological data. We compiled antibiotics consumptions via hospital pharmacy data and standardized them by calculating defined daily doses per 1000 patient-days. We analyzed the two-monthly antibiotic consumption using an interrupted time series method and built a composite endpoint for clinical outcomes based on transfer to the intensive care unit (ICU) and/or hospital death.

Results

Overall, 273 hospital stays (164 patients) in the pre-intervention and 217 (148 patients) in the post-intervention periods were analyzed. Patients were mainly hospitalized for intensive chemotherapy for acute leukemia or autologous stem-cell transplant for myeloma. Patients were slightly younger in the pre-intervention compared to the post-intervention period (median age 60.4 vs 65.2 years, p = 0.049), but otherwise comparable. After implementation of the AMS program, glycopeptide and carbapenem use decreased by 85% (p = 0.03) and 72% (p = 0.04), respectively. After adjustment on confounders, the risk of transfer to the ICU/death decreased significantly after implementation of the AMS program (post-intervention period: odds-ratio = 0.29, 95% Confidence Interval: 0.15–0.53, p < 0.001).

Conclusion

Implementation of a multidisciplinary AMS program for high-risk neutropenic patients was associated with lower carbapenem and glycopeptide use and improved clinical outcomes.
The Effect of Rebar Embedment and CFRP Confinement on the Compressive Strength of Low-Strength Concrete
Authors: Hashemi Nima , Hassanpour Sina , Vatani Oskoei Asghar
Published: March 2022

Low-strength concrete (LSC) elements are prone to several seismic and static loads and are one of the priorities to be considered for FRP strengthening. However, certain provisions should be taken into account according to provisions, as elements with considerably low compressive strength are not eligible for FRP confinement. This experimental study investigates (1) the effect of rebar planting on increasing the initial compressive strength of LSC to achieve allowable compressive strength for FRP strengthening, and (2) the effect of CFRP confinement on increasing the strength of rebar-embedded specimens and determining the most effective factor for strength improvement. For this purpose, 38 standard concrete cylinders were tested under compressive load. The variables of this study were rebar length and diameter, the compressive strength of concrete, and the number of CFRP sheets. Two initial compressive strengths below the designated compressive strength of 17 MPa (12.5 and 14.5 MPa) were selected. After determining rebar-reinforced specimens with compressive strength of more than 17 MPa, CFRP confinement and compressive tests of these cylinders were utilized. A statistical single-factor ANOVA analysis is performed to determine the most effective variable for ultimate strength and strain, individually. In the end, available models in the literature were utilized to predict experimental data. The results indicated the effectiveness of rebar planting for strength enhancement up to 53%, also showing that specimens with initial compressive strength of 14.77 MPa were suitable for CFRP confinement after rebar planting. The experimental and statistical ANOVA results demonstrated the CFRP confinement and its interaction with rebar embedment as the most effective factors with respect to increasing the load-bearing capacity of LSC concrete.
Personality as a mediator of autistic traits and internalizing symptoms in two community samples
Authors: Grella Olivia N. , Dunlap Amanda , Nicholson Alycia M. , Stevens Kimberly , Pittman Brian , Corbera Silvia , Diefenbach Gretchen , Pearlson Godfrey , Assaf Michal
Published: March 2022

Background

Autism spectrum disorder (ASD) is characterized by deficits in social functioning and is comorbid with internalizing disorders and symptoms. While personality is associated with these symptoms and social functioning in non-ASD samples, its role mediating the relationship between ASD traits and internalizing symptoms is not clear.

Methods

We studied the mediating effect of personality on the correlations between ASD traits and internalizing symptoms (i.e., depression, anxiety, stress) in two samples. Additionally, we explored the moderating effect of gender. Analyses were applied to a small (Study 1; N = 101) undergraduate sample. A broader sample recruited via an online crowdsourcing platform (Study 2; N = 371) was used to validate the results.

Results

Study 1’s mediation analyses revealed that neuroticism was the only significant mediator. Study 2 replicated these results by finding extraversion to be an additional mediator for anxiety and extraversion, openness, and agreeableness as additional mediators for stress. Moderation analyses revealed that gender was never a significant moderator.

Conclusions

These results support the effects of personality on the relationship between autism traits and internalizing symptoms. Future research should explore these effects in clinical samples to better understand the role of personality in symptomatology and the need to address it as part of intervention.
A comparison of healing and complication rates between common flaps utilized in total knee arthroplasty: a review of the literature
Authors: Chandra Akhil A. , Romanelli Filippo , Tang Alex , Menken Luke , Zhang Maximilian , Feintisch Adam , Liporace Frank A. , Yoon Richard S.
Published: March 2022

Background

Flap reconstruction with perforator, fasciocutaneous, muscular, and/or free microvascular flaps is utilized to cover wound defects and improve vascularization and antibiotic/nutrient delivery. Flap use in revision procedures for total knee arthroplasty has been explored previously; however, current data are limited and studies comparing healing and complication rates between different flap types are lacking.

Methods

A literature review was performed using PubMed on 13 January 2022. Studies were included if they reported healing and complication rates for either gastrocnemius, rectus abdominis, latissimus dorsi, fasciocutaneous, chimeric, or gracilis flaps in the setting of revision total knee arthroplasty (TKA).

Results

The final cohort included gastrocnemius (n = 421, healing rate 73.8%, complication rate 59.9%), gracilis (n = 9, healing rate 93%, complication rate 55.6%), latissimus dorsi (n = 41, healing rate 67%, complication rate 46.3%), rectus abdominis (n = 3, healing rate 100%, complication rate 0%), fasciocutaneous (n = 78, healing rate 70%, complication rate 19.2%), and chimeric flaps (n = 4, healing rate 100%, complication rate 25%). There was no significant difference when comparing healing rates across flap types (p = 0.39). There was a significant difference when comparing complication rates across flap types (p < 0.0001), with a significant difference being noted between gastrocnemius and fasciocutaneous complication rates (p < 0.0001). All other comparisons between flap types by complication rate were not significantly different.

Conclusions

Gastrocnemius flaps are the workhorse flap in the setting of revision TKA, as evidenced by this review. Healing rates did not vary significantly across flap types, which suggests that determining the appropriate flap for coverage of soft-tissue defects in revision TKA should be driven by defect size and location as well as physician experience and patient tolerance.
Combined effects of pioglitazone and doxorubicin on migration and invasion of MDA-MB-231 breast cancer cells
Authors: Malakouti Parisa , Mohammadi Mobin , Boshagh Mohammad Amin , Amini Abbasali , Rezaee Mohammad Ali , Rahmani Mohammad Reza
Published: March 2022

Background

Despite antitumor properties, chemotherapy medication can create conditions in tumor cells that work in favor of the tumor. Doxorubicin, commonly prescribed chemotherapy agents, can increase the risk of migration and invasion of tumor cells through overexpression of the CXCR4 gene by affecting downstream signaling pathways. The regulatory role of CXCR7 on CXCR4 function has been demonstrated. Therefore, it is hypothesized that combining doxorubicin with another anticancer drug could be a promising approach.

Methods

In this research, we evaluated the anti-invasive property of pioglitazone along with antitumor effects of doxorubicin on MDA-MB-231 breast cancer cell lines.

Results

There was no significant difference between two treatment groups in neither the expression nor changes in the expression of CXCR7 and CXCR4 genes (P < 0.05). Pioglitazone-doxorubicin combination reduced cell migration in tumor cells to a significantly higher extent compared to doxorubicin alone (P < 0.05).

Conclusions

Co-administration of pioglitazone and doxorubicin might reduce cell migration in breast cancer tumor cells, and that cell migration function is independent of some specific proteins.
Built heritage and planning laws in Africa: the Nigerian Experience
Authors: Adewumi Afolasade
Published: March 2022

Built heritage has been and is being threatened by natural and man-made factors such as urbanisation, climate change, civil unrest, and activities of extractive industries among others. These factors have led to the destruction of built heritage culminating in a gap in the cultural history and identity of the people. Over the years, in every country, there have been different regimes that have regulated the preservation and sustainability of built heritage sites, ranging from the traditional pre-colonial era, the colonial era and the post-colonial era. This article from the perspective of law and history, examines the trajectory of the heritage management systems over the years in Nigeria to identify necessary areas of improvements that are needed to adequately manage and protect built heritage against the identified endangering factor of urban development. From its comprehensive analysis, this paper argues that in-order to adequately manage built heritage, it is important to adopt a holistic approach that will require the harmonisation of the various heritage management systems while taking steps to document indigenous conservation methods. On the other hand, harmonisation of all heritage laws with town planning laws is essential for sustainability.
Observation and a simple model of plumose pattern on fracture surfaces of drying pastes
Authors: Sakaguchi Hidetsugu , Yamada Kazuki , Shimokawa Michiko
Published: March 2022

Plumose pattern often appears on the fracture surface of drying pastes. We show a few experimental results of the crack propagation in the drying pastes. We find that the crack propagation sometimes exhibits jump motions. We have also performed an experiment of the crack propagation in a tilted container where the crack propagates from the deeper to shallower sides. This experimental result suggests the importance of the movement of water content. We propose a simple coupled map lattice model. In the numerical simulation, a plumose-like pattern appears owing to the instability of the flat surface of the fracture. The numerical simulation reproduces the jump motions in the crack propagation. We have performed another experiment where a vertical streak pattern appears when the crack propagates downward by cutting into the top surface of the drying paste.
Spine Stereotactic Body Radiotherapy for Prostate Cancer Metastases and the Impact of Hormone Sensitivity Status on Local Control
Authors: Abugharib Ahmed , Zeng K. Liang , Tseng Chia-Lin , Soliman Hany , Myrehaug Sten , Husain Zain , Maralani Pejman Jabehdar , Larouche Jeremie , Cheung Patrick , Emmenegger Urban , Atenafu Eshetu G. , Sahgal Arjun , Detsky Jay S.
Published: March 2022

BACKGROUND:

Stereotactic body radiotherapy (SBRT) is used to deliver ablative dose of radiation to spinal metastases.

OBJECTIVE:

To report the first dedicated series of spine SBRT specific to prostate cancer (PCa) metastases with outcomes reported according to hormone sensitivity status.

METHODS:

A prospective database was reviewed identifying patients with PCa treated with spine SBRT. This included those with hormone-sensitive PCa (HSPC) and castrate-resistant PCa (CRPC). The primary end point was MRI-based local control (LC).

RESULTS:

A total of 183 spine segments in 93 patients were identified; 146 segments had no prior radiation and 37 had been previously radiated; 27 segments were postoperative. The median follow-up was 31 months. At the time of SBRT, 50 patients had HSPC and the remaining 43 had CRPC. The most common fractionation scheme was 24-28 Gy in 2 SBRT fractions (76%). LC rates at 1 and 2 years were 99% and 95% and 94% and 78% for the HSPC and CRPC cohorts, respectively. For patients treated with de novo SBRT, a higher risk of local failure was observed in patients with CRPC (P = .0425). The 1-year and 2-year overall survival rates were significantly longer at 98% and 95% in the HSPC cohort compared with 79% and 65% in the CRPC cohort (P = .0005). The cumulative risk of vertebral compression fracture at 2 years was 10%.

CONCLUSION:

Favorable LC rates were observed after spine SBRT for PCa metastases; strategies to improve long-term LC in patients with CRPC require further investigation.
Dysregulated mitochondrial metabolism upon cigarette smoke exposure in various human bronchial epithelial cell models
Authors: Tulen Christy B. M. , Wang Ying , Beentjes Daan , Jessen Phyllis J. J. , Ninaber Dennis K. , Reynaert Niki L. , van Schooten Frederik-Jan , Opperhuizen Antoon , Hiemstra Pieter S. , Remels Alexander H. V.
Published: March 2022

Exposure to cigarette smoke (CS) is the primary risk factor for developing chronic obstructive pulmonary disease. The impact of CS exposure on the molecular mechanisms involved in mitochondrial quality control in airway epithelial cells is incompletely understood. Undifferentiated or differentiated primary bronchial epithelial cells were acutely/chronically exposed to whole CS (WCS) or CS extract (CSE) in submerged or air–liquid interface conditions. Abundance of key regulators controlling mitochondrial biogenesis, mitophagy and mitochondrial dynamics was assessed. Acute exposure to WCS or CSE increased the abundance of components of autophagy and receptor-mediated mitophagy in all models. Although mitochondrial content and dynamics appeared to be unaltered in response to CS, changes in both the molecular control of mitochondrial biogenesis and a shift toward an increased glycolytic metabolism were observed in particular in differentiated cultures. These alterations persisted, at least in part, after chronic exposure to WCS during differentiation and upon subsequent discontinuation of WCS exposure. In conclusion, smoke exposure alters the regulation of mitochondrial metabolism in airway epithelial cells, but observed alterations may differ between various culture models used.

This article has an associated First Person interview with the joint first authors of the paper.
Enterprise resource planning implementation within science and technology park (STP) organisations: an avenue for future research. A systematic review.
Authors: Harun Sharbani , Dorasamy Magiswary , Bin Ahmad Abdul Aziz , Yap Ching Seng , Harguem Saida
Published: March 2022

Background: Enterprise resource planning (ERP) is critical to enhancing the ability to control commercial activities and results in a competitive advantage when combined with an organisation's existing competitive advantages. However, our practise review reveals that end users resist ERP implementation because the resulting changes will alter the current status quo. The implementation of an ERP system in an organisation is complex as it affects multiple areas of the business. Resistance to change is cited as a factor of ERP failure.

Methods: In this study, we conducted a systematic literature review using Transfield’s five stages and established a conceptual framework for ERP system implementation in science and technology parks (STPs). Articles collected from Emerald, Science Direct, ProQuest and Scopus databases between 1st June 2021 and 15th June 2021. Two authors were assigned to check the suitability of the articles in order to avoid risk of bias. Articles were analysed based on components of a research paper and the data was tabulated using MS Excel.

Results: Only eight papers (0.011% of all the papers) appeared when we searched for papers related to ERP with a focus on post ERP Implementation, end-user behaviours, organisational performance, and the accelerated SAP (system application and product) methodology. We found that there are hardly any articles on ERP post implementations in STP context particularly based on the evaluation part of accelerated SAP.  

Conclusions: Results indicate the lack of studies in this field, particularly those addressing issues related to STP. This study attempted to broaden the understanding of the ERP's effectiveness, particularly in terms of an organisation's operational performance.
Managing Relationships Between Restaurants and Food Delivery Platforms: Conflict, Contracts, and Coordination
Authors: Feldman Pnina , Frazelle Andrew E. , Swinney Robert
Published: March 2022

Restaurant delivery platforms collect customer orders via the Internet, transmit them to restaurants, and deliver the orders to customers. They provide value to restaurants by expanding their markets, but critics claim they destroy restaurant profits by taking a percentage of revenues and generating congestion that negatively impacts dine-in customers. We consider these tensions using a model of a restaurant as a congested service system. We find that the predominant industry contract, in which the platform takes a percentage cut of each delivery order (a “commission”), fails to coordinate the system because the platform does not internalize its effect on dine-in revenues; this leads to prices that are too low, reducing the restaurant’s margins and leaving money on the table for both firms. Two commonly proposed remedies to this problem (commission caps and allowing the restaurant to set a price floor on the platform) can increase restaurant revenue but do not solve the coordination issue. We thus propose an alternative, practical coordinating contract that is a variation of the current industry standard: for each delivery order, the platform pays the restaurant a percentage revenue share and a fixed fee. We show that this contract, appropriately designed, coordinates the system, protects restaurant margins by ensuring a lower bound on its revenue per delivery order, and allocates revenue between the restaurant and the platform with a high degree of flexibility.

This paper was accepted by Victor Martinez-de-Albeniz, operations management.

Supplemental Material: The e-companion is available at https://doi.org/10.1287/mnsc.2022.4390 .
Spatial Price Integration in Commodity Markets with Capacitated Transportation Networks
Authors: Birge John R. , Chan Timothy C. Y. , Pavlin J. Michael , Zhu Ian Yihang
Published: March 2022

The impact of transportation constraints in commodity markets has become increasingly relevant as many markets experience demand and supply growth that continues to outpace the growth in transportation infrastructure. In “Spatial Price Integration in Commodity Markets with Capacitated Transportation Networks,” Birge, Chan, Pavlin, and Zhu examine the relationship between the spatial distribution of commodity prices and the underlying transportation network that supports the flow of these commodities. The authors show that under mild assumptions, the prices between all locations must be bounded when there are no bottlenecks in the network. Conversely, a bottleneck can cause different locations to incur a congestion surcharge that pushes prices out of these bounds. The authors propose a time series analysis technique using mixed integer optimization that estimates the value of these surcharges from commodity prices and then apply the technique to study how gasoline prices changed after a series of well-documented supply chain disruptions in the Southeastern U.S. gasoline market.
Phentermine-Associated Atrial Fibrillation: Case Report and Literature Review
Authors: Manasrah Nouraldeen , Herath Chandima J , Al Sbihi Ali , Alqasem Sarah , Kao Andrew S , Chaudhary Ahmed J , Ismail Rana
Published: March 2022

Obesity has become a major public health problem with increased prevalence. It is associated with cardiovascular mortality. Phentermine is approved for short-term obesity treatment in conjunction with lifestyle modifications. Palpitation is a well-documented side effect of phentermine. However atrial fibrillation (AF) is rarely reported. We present a case of new-onset AF in a healthy woman who was recently started on phentermine for weight loss.
Kariyere İlişkin Ebeveyn Destek Algısı Ölçeği (KİEDAÖ): Geçerlik ve Güvenirlik Çalışması
Authors: KARAMENDERES Ayşegül , SİYEZ Diğdem Müge
Published: March 2022

Bu çalışmanın amacı, Kariyere İlişkin Ebeveyn Destek Algısı Ölçeği’nin (KİEDAÖ) Türkçeye uyarlanması ve psikometrik özelliklerinin incelenmesidir. Araştırmanın çalışma grubunu ortaokul ve lisede öğrenim gören 351 ergen (196 kız, 144 erkek ve 11 herhangi bir cinsiyet belirtmeyen katılımcı) oluşturmaktadır. KİEDAÖ’nün geçerlik çalışması kapsamında yapılan doğrulayıcı faktör analizine göre ölçek orijinalinde olduğu gibi Destekleyici, Müdahale Edici ve İlgisiz olmak üzere üç alt boyuttan oluşmaktadır. Benzer ölçek geçerliği kapsamında Kariyer Seçiminde Aile Etkisi Ölçeği (KSAEÖ) ile KİEDAÖ’nün Destekleyici ve Müdahale Edici alt boyutları arasında pozitif yönlü, KSAEÖ ile KİEDAÖ’nün İlgisiz alt boyutu arasında negatif yönlü anlamlı ilişkiler olduğu görülmüştür. Ölçeğin Cronbach’s Alpha (α) ve McDonald’s Omega (ω) iç tutarlık katsayıları Destekleyici alt boyutu için .86, Müdahale Edici alt boyutu için .84, İlgisiz alt boyutu için .83 bulunmuştur. Sonuç olarak bu bulgular, Kariyere İlişkin Ebeveyn Destek Algısı Ölçeği’nin ortaokul ve lise öğrencilerinin kariyere ilişkin ebeveynlerinden algıladıkları desteği değerlendirebilmek için geçerli ve güvenilir bir ölçme aracı olduğunu ortaya koymaktadır.
Deciding the Future of Healthcare Leadership: A Call for Undergraduate and Graduate Healthcare Administration Education
Authors:   Phoenix Pulmonary and Critical Care Research and Education Foundation, Gilbert, AZ USA, Robbins Richard , Willis Brigham
Published: March 2022

No abstract available. Manuscript truncated after 150 words. Good medical leadership is the cornerstone of quality healthcare. However, leadership education for physicians has traditionally been largely ignored, with a focus instead on technical competence. As a result, physicians in many cases have abdicated their role as medical leaders to others, usually businessmen without medical training or expertise, and often a lack of understanding of the human issues inherent to healthcare. Recently, the Southwest Journal of Pulmonary, Critical Care & Sleep published a manuscript, “Leadership in Action: A Student-Run Designated Emphasis in Healthcare Leadership”, describing a curriculum designed to develop future healthcare leaders (1). Hopefully this and similar curricula will prepare physicians in setting direction, demonstrating personal qualities, working with others, managing services, and improving services (2). The US suffers from a crisis in healthcare partially rooted in a lack of physician- and patient-oriented leadership which has led to “hyperfinancialization” in many instances. Beginning in the 1980’s there has …
Efficient multiplexed illumination and imaging approach for Fourier ptychographic microscopy
Authors: Lin Binbin , Zhao Jufeng , Cui Guangmang , Zhang Peiwei , Wu Xiaohui
Published: March 2022

A Fourier ptychographic microscope (FPM) can obtain images with high resolution and a wide field of view (FOV). However, the time-consuming process of image acquisition and computation leads to low reconstruction efficiency. Therefore, we propose a state-multiplexed method through an optimized illumination pattern to accelerate FPM. First, to reduce the redundancy of the spectrum and analyze the impact of missing a certain sub-spectrum on overall spectrum reconstruction, we use an image quality evaluation method to obtain the differential expression between missing a certain LED lighting and all LED lighting. Second, we use the difference expression to select the important LEDs and obtain an optimized illumination pattern that lights up only the LEDs in the central area and the edge LEDs. Then, we update the multiplexing method with the new, to the best of our knowledge, illumination pattern and obtain satisfactorily reconstructed images. Finally, we validate the effectiveness and efficiency of our method with both simulation and experiments. Compared with the traditional method, our method accelerates the reconstruction speed of FPM while ensuring a large FOV and high resolution, saving about 73% of time.
2021 JOSA A Emerging Researcher Best Paper Prize: editorial
Authors: Courtial Johannes , Fischer David , Hexley Allie C. , Larina Irina V. , Marino Antigone , Korotkova Olga
Published: March 2022

JOSA A Editor-in-Chief, Olga Korotkova, Feature Editor, Johannes
Courtial, and members of the 2021 Emerging Researcher Best Paper Prize
Committee announce the recipient of the 2021 prize for the best paper
published by an emerging researcher in the Journal.
Frequency-comb-induced radiation pressure force in dense atomic clouds
Authors: Kruljac Mateo , Buhin Danijel , Kovačić Domagoj , Vulić Vjekoslav , Aumiler Damir , Ban Ticijana
Published: March 2022

We investigate the frequency-comb-induced radiation pressure force acting on a cloud of cold

87

R
b

atoms. Reduction and spectral broadening of the frequency comb force are observed as the cloud’s optical thickness is increased. Since the radiation pressure force is uniquely determined by light scattered by an atomic cloud, we discuss different scattering mechanisms and point to the shadow effect as the dominant mechanism affecting the FC-induced force in resonantly excited dense atomic clouds. Our results improve the understanding of the interaction of frequency comb light with many-atom ensembles, which is essential for novel frequency comb applications in simultaneous multispecies cooling and self-ordering, multimode quantum memories, and quantum computing.
Polarization-controlled terahertz generation by bicircular longer-wavelength laser fields
Authors: Wang Guo-Li , Qi Hai-Xia , Li Ya-Ning , Jiao Zhi-Hong , Zhao Song-Feng , Zhang Lei
Published: March 2022

When compared with other laser configurations, stronger terahertz (THz) waves can be generated from gaseous plasmas driven using two-color

ω
+
2
ω

circularly polarized laser fields with the same helicity (CP-S), but consideration of the THz polarization state shows that these waves are linearly polarized. Here, we show that polarization-controlled THz radiation, including circularly polarized radiation, can be generated using CP-S pump fields. Unlike the conventional multi-cycle

800

n
m

+

400

n
m

combination, we use longer-wavelength or few-cycle laser pulses to generate nonzero net currents along two orthogonal directions with a

∼

±

π

/

2

phase difference between them because of laser field symmetry breaking. When the current distribution’s axis of symmetry is ascertained, the THz polarization direction can be confirmed.
Joint communication and radar sensing functions system based on photonics at the W-band
Authors: Wang Yanyi , Liu Jiaxuan , Ding Junjie , Wang Mingxu , Zhao Feng , Yu Jianjun
Published: March 2022

The photonics-based technology has the advantages of wide bandwidth in millimeter wave (mm-wave) communication and radar sensing systems. In the present work, we propose a novel joint communication and radar sensing functions system based on photonics at the W-band. In the proposed system, the broadband linear frequency modulated (LFM) signal and high-speed M-quadrature amplitude modulation (MQAM) signal are simultaneously obtained by heterodyning two free-running external cavity lasers (ECLs). Based on this system, a communication rate of 78 Gbit/s and a radar with a 5-GHz bandwidth is achieved. This is a good solution to incorporate a high-speed communication and high-resolution radar sensing functions system.
Real-time measurement of parametric influences on the refractive index and length changes in silica optical fibers
Authors: Rana Sohel , Fleming Austin , Subbaraman Harish , Kandadai Nirmala
Published: March 2022

In this paper, we present a simple cascaded Fabry-Perot interferometer (FPI) that can be used to measure in real-time the refractive index (RI) and length variation in silica optical fibers caused due to external physical parameters, such as temperature, strain, and radiation. As a proof-of-concept, we experimentally demonstrate real-time monitoring of temperature effects on the RI and length and measure the thermo-optic coefficient (TOC) and thermal expansion coefficient (TEC) by using the cascaded FPI within a temperature range of 21–486°C. The experimental results provide a TEC of 5.53 × 10−7/°C and TOC of 4.28 × 10−6/°C within the specified temperature range. Such a simple cascaded FPI structure will enable the design of optical sensors to correct for measurement errors by understanding the change in RI and length of optical fiber caused by environment parameters.
Efficient high-charge Laguerre-Gaussian mode conversion by using a periscopic axicon mirror
Authors: Zhang S. J. , Zhuo H. B. , Yin Y. , Zou D. B. , Zhao N. , Zhou W. M.
Published: March 2022

Laguerre-Gaussian (LG) modes can be converted from fundamental Gaussian mode by using phase optical elements such as spiral phase plates (SPP), but the conversion efficiency is strongly reduced in high charge plates because of the transverse intensity deviation. In this paper, a three-step scheme is proposed to dramatically improve the conversion efficiency. First, a fundamental Gaussian beam is converted to a 1st-order LG beam via a 1st-order SPP and a spatial filtering system. Then, by using a periscopic axicon mirror (PAM), the lst-order LG beam is transformed into an annular beam with larger beam radius. Finally, by using a second high-order SPP, this intensity-matched ring beam can be effectively converted to a high-charge LG
0l
beam. Through optimization of the PAM's parameter, the total conversion efficiency from fundamental Gaussian beam to LG
0l
mode as high as 91.85% is obtained, which is much higher than the case without PAM. Numerical simulations are carried out by the particle-in-cell (PIC) code EPOCH to verify the effectiveness of the scheme.
Dual-band chiral metasurface for independent controls of spin-selective reflections
Authors: Gou Yue , Ma Hui Feng , Wang Zheng Xing , Wu Liang Wei , Wu Rui Yuan , Cui Tie Jun
Published: March 2022

The development of chiral metasurfaces with spin-selective reflection or transmission provides a new way to control the circularly polarized (CP) waves. However, it is still a great challenge to independently manipulate the polarization, frequency, and phase of the spin-selective reflected waves in different operating bands, which may have potential applications in improving the data capacity of microwave and optical communication systems. Here, a dual-band chiral metasurface is proposed to generate gigantic intrinsic chirality with strong circular dichroism (CD) in two different frequency bands by piecing two typical mono-chiral units together. The polarization, frequency and phase of the spin-selective reflected waves can also be independently designed in the two operating bands by adjusting the configuration of the chiral unit structures. Based on the proposed chiral structures, a dual-band chiral metasurface with spin-selective anomalous reflections is designed and demonstrated by both simulations and experiments. The results show that the polarization of spin-selective reflected waves can be customized by selecting appreciate chiral structures, while the wavefront of the spin-selective reflected waves can be further controlled by designing their arrangement.
Freeform measurement method based on differential confocal and real-time comparison
Authors: Tang Yingqi , Liu Yuhan , Wang Wenbin , Liu Chao , Li Yun , Song Yin , Xu Kemi , Qiu Lirong , Zhao Weiqian
Published: March 2022

To meet the need for the high-precision contactless measurement of the freeform surface profile during the manufacturing, we propose a high-precision measurement method that combines the laser differential confocal trigger sensor (LDCTS) and the real-time comparison method using reference planes (RCMRP). LDCTS is used to measure the freeform surface under test (FSUT), which enables the high-precision measurement of the surface profile with the large roughness and local inclination. Through the real-time comparisons of the coordinate changes of the reference planes and FSUT, the dominant straightness and rotation errors can be separated based on the error model and thus the spatial motion errors can be significantly reduced along all three axes. Combing these two strategies, we find that the inclination measurement capacity becomes larger than 25° and the repeated measurement accuracy is improved to be better than 10 nm within the horizontal scanning range of 150 mm × 150 mm. Compared with the non-RCMRP method, the repeated measurement accuracy is improved by at least 5 times. We believe the proposed method provides a strategy for the high-precision measurement of freeform surface profile with large local inclination and roughness during different manufacturing periods.
Estimation of turbulence parameters in the atmospheric boundary layer of the Bohai Sea, China, by coherent Doppler lidar and mesoscale model
Authors: Jin Xiang , Song Xiaoquan , Yang Yawen , Wang Mian , Shao Shiyong , Zheng Haitao
Published: March 2022

Obtaining turbulence parameters in the marine atmospheric boundary layer (MABL) is limited by the observation environment and cost. Therefore, estimating based on the weather forecast model or combining the model output with limited observations is a more flexible choice. We conducted cruise observation experiments in the Bohai Sea, China, from May 17 to June 4, 2021. On the basis of the wind profile observed by the coherent Doppler lidar and the temperature, as well as pressure profiles output by the Weather Research and Forecasting (WRF) model, we implemented the Tatarskii turbulence model to estimate the refractive index structure constant

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2

in the atmospheric boundary layer of the Bohai Sea under clear sky. The temporal and spatial variations of turbulence in the Bohai Sea atmospheric boundary layer are studied by combining the vertical velocity variance

σ

w

2

, skewness Ske and kurtosis Kur. The performance of simulated

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2

and meteorological parameters in the WRF in the atmospheric boundary layer at the Bohai Sea is evaluated through the experimental measurements of UAV-borne (unmanned aerial vehicle) radiosonde and lidar. Finally, we give the model of the

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variation with height in the atmospheric boundary layer at the Bohai Sea. The results show that WRF can better simulate

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in most cases. The bias between the measured and simulated

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is within one order of magnitude, and the root mean square error ( RMSE ) is within two orders of magnitude. Due to the potential uncertainty of the WRF, the RMSE between the measured and simulated wind speed is 4 ms−1 to 6 ms−1, which is almost two times of the result in previous studies on the underlying land surface. The overall changes of

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and

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2

are similar when the turbulence is well mixed and developed, which shows the consistency in both of optical and dynamics turbulence. But this consistency is not absolute. The temperature difference between the sea surface and the atmosphere leads to the widespread existence of an inversion layer from the sea surface to hundreds of meters in the Bohai Sea. The suppression of the inversion layer weakens the near sea surface turbulence. There is an enhancement of turbulence intensity below the inversion layer and a decrease from the upper inversion layer to top of the boundary layer among the entire boundary layer, also, the position of the inflection point is determined by the height of top of the inversion layer. The main results of this study are the reference significance for further understanding the development and change characteristics of turbulence in the MABL.
Mutual dynamics between synchronous solitons in a bidirectional mode-locked fiber laser
Authors: Li Yujia , Wang Chao , Huang Dongmei , Chen Hongjie , Li Feng
Published: March 2022

In this Letter, the mutual dynamics between synchronous solitons in a bidirectional mode-locked fiber laser are studied via dispersive Fourier transform methodology. We explore the spectral evolution and the statistical correlations between solitons with bidirectional propagation, indicating the low and high mutual linear dependences of the spectral energy jitters in stable and breathing mode-locking states, respectively. Moreover, to the best of our knowledge, the oscillating and sliding phase dynamics are experimentally revealed by the interference between bidirectional breathing solitons in ultrafast fiber lasers for the first time. Our findings enrich the understanding of the internal mutual dynamics between bidirectional solitons, which guides the extension of their potential applications, such as Sagnac-effect-based optical sensing.
Fabrication and characterization of a gadolinium-doped terbium gallium garnet crystal with an enhanced Verdet constant
Authors: Chen Zhe , Zhu Ling , Yi Jiyong , Yang Chao
Published: March 2022

Magneto-optical materials based on Tb3Ga5O12 (TGG) crystals offer promising opportunities when used in modern Faraday isolators (FIs). Gadolinium (Gd)-doped TGG (Gd:TGG) crystals with high transmittance were prepared using the Czochralski (Cz) method. The as-prepared crystal presented a high optical transmittance of up to 80.0% in the range from 520 nm to 1520 nm. The Verdet constants of the as-grown crystal at 405.0, 533.0, 632.0, and 1064.0 nm were −583.0, −230.1, −150.3, and −50.3 rad m−1 T−1, respectively. The measured value at 1064 nm was about 1.3 times stronger than that of TGG. Thus, it could minimize the strength of the magnet of Faraday rotators. These excellent characteristics make Gd:TGG single crystal an attractive magneto-optical material.
Vectorial spin Hall effect of light upon tight focusing
Authors: Khonina Svetlana N. , Golub Ilya
Published: March 2022

The spin Hall effect of light is a manifestation of angular momentum conservation in the process of spin–orbit interaction of light. This optical Hall effect is exhibited in tight focusing of a circularly polarized asymmetric input beam as a shift of the center of gravity of the focal spot in the transverse plane, perpendicular to the direction/axis of symmetry breaking. It is commonly established that the direction of this shift depends on the sign of the spin. Here we show, for the first time, to the best of our knowledge, both analytically and by numerical simulation, that different Cartesian components of an asymmetric circularly polarized focused beam shift in opposite directions by different amounts. Moreover, these shifts depend on the type and degree of the asymmetry and thus can be tuned/controlled. We show how these field components’ shifts are related to spin and orbital angular momentum shifts. These findings shed new light on the spin optical Hall effect, facilitate new/simpler ways to measure it, and may broaden the gamut of its applications in manipulation and trapping of particles by light and precision metrology.
Pooled testing of traced contacts under superspreading dynamics
Authors: Tsirtsis Stratis , De Abir , Lorch Lars , Gomez-Rodriguez Manuel
Published: March 2022

Testing is recommended for all close contacts of confirmed COVID-19 patients. However, existing pooled testing methods are oblivious to the circumstances of contagion provided by contact tracing. Here, we build upon a well-known semi-adaptive pooled testing method, Dorfman’s method with imperfect tests, and derive a simple pooled testing method based on dynamic programming that is specifically designed to use information provided by contact tracing. Experiments using a variety of reproduction numbers and dispersion levels, including those estimated in the context of the COVID-19 pandemic, show that the pools found using our method result in a significantly lower number of tests than those found using Dorfman’s method. Our method provides the greatest competitive advantage when the number of contacts of an infected individual is small, or the distribution of secondary infections is highly overdispersed. Moreover, it maintains this competitive advantage under imperfect contact tracing and significant levels of dilution.
Survival analysis of pathway activity as a prognostic determinant in breast cancer
Authors: Jeuken Gustavo S. , Tobin Nicholas P. , Käll Lukas
Published: March 2022

High throughput biology enables the measurements of relative concentrations of thousands of biomolecules from e.g. tissue samples. The process leaves the investigator with the problem of how to best interpret the potentially large number of differences between samples. Many activities in a cell depend on ordered reactions involving multiple biomolecules, often referred to as pathways. It hence makes sense to study differences between samples in terms of altered pathway activity, using so-called pathway analysis. Traditional pathway analysis gives significance to differences in the pathway components’ concentrations between sample groups, however, less frequently used methods for estimating individual samples’ pathway activities have been suggested. Here we demonstrate that such a method can be used for pathway-based survival analysis. Specifically, we investigate the pathway activities’ association with patients’ survival time based on the transcription profiles of the METABRIC dataset. Our implementation shows that pathway activities are better prognostic markers for survival time in METABRIC than the individual transcripts. We also demonstrate that we can regress out the effect of individual pathways on other pathways, which allows us to estimate the other pathways’ residual pathway activity on survival. Furthermore, we illustrate how one can visualize the often interdependent measures over hierarchical pathway databases using sunburst plots.