bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring perspectives on antimicrobial stewardship: a qualitative study of health managers in Kenya
Authors: Mbugua Samuel Mungai , Njoroge George , Kijogi Caroline , Kamita Moses , Kimani Rachel , Mwaura Peter , Aidi Bibianne Waiganjo , Gitaka Jesse
Published: November 2020

Background

Antimicrobial resistance is a significant public health concern with the establishment of antimicrobial stewardship in hospitals being increasingly obligatory. Perspectives and insights of health managers on antimicrobial stewardship (AMS), complementary health services and building blocks are imperative towards implementation of robust AMS programs. This study aimed to understand perspectives of hospital managers on AMS and identify areas of management engagement while addressing potential blockades to change.

Methods

A cross-sectional, qualitative, multicenter study was conducted in three hospitals in Kenya. Key-informant interviews on perspectives on AMS were administered to hospital managers. Qualitative data was captured using audio tapes and field notes, transcribed and managed using NVivo 12 software. An iterative process was used to develop the thematic framework and updated in two rounds of iteration analysis. Analysis charts for each emergent theme were developed and categorized across all participants.

Results

Perspectives on AMS are described in five thematic categories; Importance of antimicrobial stewardship and the role of medicines and therapeutics committee, availability of antimicrobial formulary and usage surveillance systems, laboratory competency and recommendations for infection prevention and management, educational resources and communications channels available, building blocks and low-lying fruits for Antimicrobial Stewardship Committees. The role of stewardship collaboration in diagnosis and antimicrobial prescription was alluded to with managers indicating a growing rise in occurrence of antimicrobial resistance. There lacked contextualized, hospital specific antimicrobial formulary and adequate laboratory competency. Staff training and communication channels were available in varying capacity across the three hospitals. Building blocks identified include medicines and therapeutics committee, education, and training platforms (Continuous Medical Education and Continuous Professional Development activities) and hospital leadership commitment.

Conclusions

The practice of antimicrobial stewardship is not implemented and well developed as demonstrated by lack of core AMS complementary health services. However, the health managers are aware of the fundamental importance of antimicrobial stewardship programs and the vast benefits of implementation and institutionalization of AMS to hospitals and their clients. The findings underpin the importance of understanding and incorporating perspectives of health managers on existing contextual mechanisms that can be leveraged on to establish robust AMS programs in the fight against antimicrobial resistance.
Contralateral pupillary dilatation and hemiparesis: Kernohan’s notch revisited
Authors: Agrawal Amit , Kumar V. A. Kiran , Moscote-Salazar Luis Rafael
Published: November 2020

Intracranial mass lesions can lead to transtentorial uncal herniation, and pupillary asymmetry is a well-recognized sign of impending cerebral herniation. Impending uncal herniation can lead to ipsilateral, bilateral, or uncommonly the contralateral pupillary dilatation. We report a case of a 22-year old, who had contralateral pupillary dilatation due to expanding intracranial mass lesion and recovered well after neurosurgical intervention. This case illustrates contralateral pupillary dilatation (“false-localizing” sign) in a sub-group of patients, and if untreated and ICP continues to rise, this is followed by ipsilateral pupil dilatation.
An English-language adaptation of the Interpersonal Trust Short Scale (KUSIV3)
Authors: Nießen Désirée , Beierlein Constanze , Rammstedt Beatrice , Lechner Clemens M.
Published: November 2020

The Interpersonal Trust Short Scale—the English-language adaptation of the Kurzskala Interpersonelles Vertrauen (KUSIV3)—measures interpersonal trust as a psychological disposition with just three items (completion time ~ 30 s). The items of the German-language source version were translated into English using the TRAPD approach. Our empirical validation based on a heterogeneous quota sample in the UK shows that all the reliability coefficients of the English-language adaptation and its correlations with external variables are satisfactory and comparable to those of the German-language source version. Moreover, the results of measurement invariance testing suggest that metric measurement invariance of the scale holds when comparing the UK and Germany, implying the comparability of correlations based on the latent factors across the two nations. As an ultra-short scale, KUSIV3 lends itself to the assessment of interpersonal trust particularly in survey contexts in which assessment time or questionnaire space are limited. It is applicable in a variety of research disciplines, including psychology, sociology, and economics.
Extending the global-direction stencil with “face-area-weighted centroid” to unstructured finite volume discretization from integral form
Authors: Kong Lingfa , Dong Yidao , Liu Wei , Zhang Huaibao
Published: November 2020

Accuracy of unstructured finite volume discretization is greatly influenced by the gradient reconstruction. For the commonly used k-exact reconstruction method, the cell centroid is always chosen as the reference point to formulate the reconstructed function. But in some practical problems, such as the boundary layer, cells in this area are always set with high aspect ratio to improve the local field resolution, and if geometric centroid is still utilized for the spatial discretization, the severe grid skewness cannot be avoided, which is adverse to the numerical performance of unstructured finite volume solver. In previous work [Kong, et al. Chin Phys B 29(10):100203, 2020], we explored a novel global-direction stencil and combined it with the face-area-weighted centroid on unstructured finite volume methods from differential form to realize the skewness reduction and a better reflection of flow anisotropy. Greatly inspired by the differential form, in this research, we demonstrate that it is also feasible to extend this novel method to the unstructured finite volume discretization from integral form on both second and third-order finite volume solver. Numerical examples governed by linear convective, Euler and Laplacian equations are utilized to examine the correctness as well as effectiveness of this extension. Compared with traditional vertex-neighbor and face-neighbor stencils based on the geometric centroid, the grid skewness is almost eliminated and computational accuracy as well as convergence rate is greatly improved by the global-direction stencil with face-area-weighted centroid. As a result, on unstructured finite volume discretization from integral form, the method also has superiorities on both computational accuracy and convergence rate.
Planning for change: Transformation labs for an alternative food system in Cape Town, South Africa
Authors: Pereira Laura , Drimie Scott , Zgambo Olive , Biggs Reinette
Published: November 2020

There has been a call for more participatory processes to feed into urban planning for more resilient food systems. This paper describes a process of knowledge co-production for transforming towards an alternative food system in Cape Town, South Africa. A ‘transformative space’ was created though a T-Lab process involving change-agents advocating for an alternative food system, and was designed to discuss challenges in the local food system from a range of perspectives, in order to co-develop potentially transformative innovations that could feed into government planning. In this paper, we describe and reflect on the T-lab in order to consider whether its design was able to meet its objective: to initiate an experimental phase of coalition-building by diverse actors that could feed into the provincial government’s strategic focus on food and nutrition security. Our findings indicate that T-labs have the potential to be important mechanisms for initiating and sustaining transformative change. They can be complementary to urban planning processes seeking to transform complex social-ecological systems onto more sustainable development pathways. However, as with all experimental co-production processes, there is significant learning and refinement that is necessary to ensure the process can reach its full potential. A key challenge we encountered was how to foster diversity and difference in opinions in the context of significant historical legacies of inequality, whilst simultaneously acting for ‘the common good’ and seeking ways to scale impact across different contexts. The paper concludes with deliberations on the nature of planning and navigating towards systemic transformative change.
Molecular docking and QSAR theoretical model for prediction of phthalazinone derivatives as new class of potent dengue virus inhibitors
Authors: Adawara Samuel Ndaghiya , Shallangwa Gideon Adamu , Mamza Paul Andrew , Ibrahim Abdulkadir
Published: November 2020

Background

Dengue fever is a key public health unease in various tropical and sub-tropical regions. The improvement of existing agents that can inhibit the dengue virus is therefore of utmost importance. In this work, the QSAR study was carried out on 25 molecules of phthalazinone derivatives which have been reported to possess excellent dengue virus inhibitory activity. Density functional computational technique was used in the optimisation of the molecules with the basis set at theory level (B3LYP, 6-31G*) respectively. The multiple linear regression (MLR) model was built using genetic function approximation (GFA) in the material studio software package. Also, in this study, molecular docking simulation was carried between dengue virus serotype 2 protease (PDB CODE: 6mol) and some selected phthalazinone derivatives (compounds 1, 2, 7, 11, and 21).

Results

The model was robust as evidenced by validation and robustness statistical parameter which include predicted R2pred., adjusted R2adj., cross-validated Q2 and R2 regression coefficient, etc (R2pred. = 0.71922, R2adj. = 0.939699, Q2CV = 0.905909, R2 = 0.955567) respectively. The molecular docking studies conducted in this study have outlined the binding affinities of the selected compounds (1, 2, 7 11, and 21) which are all in good correlation with their respective pIC50 values. The free binding affinities of the selected compounds were found to be (− 8.7, − 8.8, − 8.7, − 8.3, and − 8.9 kcal/mol) respectively, compound 21 with the binding affinity of − 8.9 kcal/mol had the best binding free energy with the protease relative to other compounds under consideration.

Conclusion

The MLR-GFA model study alongside with the molecular docking analysis has essentially provided a valuable and in-depth understanding as well as knowledge for the development of novel chemical compounds with enhanced inhibitory potential against the dengue virus serotype 2 (DNV-2). Hence, the developed model can be applicable in predicting the anti-dengue activity of a new set of chemical compounds that fall within its applicability domain.
Comparison between male and female teachers in Egyptian primary schools regarding the effect of teaching on their voice
Authors: Zaky E. A. , Mamdouh H. , Maher A. , Khalaf Z.
Published: November 2020

Background

Teachers are more likely to develop voice disorders compared to non-teachers in other occupations. Teachers are often cited as a high-risk group for vocal dysfunction as they use their voices extensively over their profession for instructing and managing students, also due to other extra loading factors, such as background noise, long speaking distance, poor room acoustics, and lack of adequate equipment, like voice amplifiers. The primary school teachers are particularly at risk as they have little opportunity for voice rest during the working day. Gender is another factor affecting incidence of voice disorders. Female teachers seem to be more affected by voice disorders than male teachers. The aim of our study was to compare between genders (male–female teachers) in primary schools to show the effect of teaching and other risk factors on their voice for proper management.

Results

The study showed that there were statistically significant differences between male teachers and female teachers regarding history of voice change; female teachers had history of voice change more than male teachers. Female teachers suffered from emotional stress more than male teachers, and this affects their voice. In addition, study showed a significant association between the grade of dysphonia and VHI.

Conclusion

There is evidence that female teachers are complaining more of voice change and suffering from voice disorders than males. Besides, female teachers are showing a higher degree of emotional stress. This may necessitate a combined assessment of the voice and psychological profile of all teachers with voice change.
High-flow nasal oxygen therapy versus conventional oxygen therapy and non-invasive mechanical ventilation in patients with acute respiratory failure and post-mechanical ventilation
Authors: Abo-Galala Mona M. A. , Galal Iman H. E. , Abdel-Fattah Eman B. , Kamel Basel B. M.
Published: November 2020

Background

Oxygen therapy is essential in the management of patients with respiratory problem, including after endotracheal extubation. Conventional oxygen devices may be inadequate in patients requiring high inspiratory flow. HFNC has a growing place in the repertoire of respiratory therapies. The purpose of this study was to compare the efficiency, tolerability, and outcome of HFNC in patients with respiratory failure and post-mechanical ventilation patients in comparison to NIV and conventional oxygen devices.

Results

In case of respiratory failure patients, there was non-significant statistical difference between HFNC, conventional oxygen therapy and NIV, regarding the difference in ABGs, vital data, and dyspnea scores, at successive time points, except for PO2 after 30 min in patients received NIV, which was significantly higher. There was non-significant statistical difference between the three mentioned modalities of oxygen therapy regarding comfort and clinical outcome.

In case of post-extubation patients, there was non-significant statistical difference between the HFNC and conventional oxygen therapy regarding clinical parameters, comfort and outcome.

Conclusions

HFNC is comparable to conventional oxygen therapy in respiratory failure and post-extubation patients. HFNC is comparable to NIV in respiratory failure patients.
Quality care metrics (QC-M) in nursing and midwifery care processes: a rapid realist review (RRR) protocol
Authors: O'Connor Laserina , Coffey Alice , Lambert Veronica , Casey Mary , McNamara Martin , Teeling Sean Paul , O'Doherty Jane , Barnard Marlize , Corcoran Yvonne , Davies Carmel , Doody Owen , Frawley Timothy , O'Brien Denise , Redmond Catherine , Smith Rita , Somanadhan Suja , Noonan Maria , Bradshaw Carmel , Tuohy Dympna , Gallen Anne
Published: November 2020

Background: In 2018, the Office of the Nursing and Midwifery Services Director (ONMSD) completed phase one of work which culminated in the development and launch of seven research reports with defined suites of quality care process metrics (QC-Ms) and respective indicators for the practice areas – acute care, midwifery, children’s, public health nursing, older persons, mental health and intellectual disability nursing in Ireland. This paper presents a rapid realist review protocol that will systematically review the literature that examines QC-M in practice; what worked, or did not work for whom, in what contexts, to what extent, how and why?

Methods: The review will explore if there are benefits of using the QC-Ms and what are the contexts in which these mechanisms are triggered. The essence of this rapid realist review is to ascertain how a change in context generates a particular mechanism that produces specific outcomes. A number of steps will occur including locating existing theories on implementation of quality care metrics, searching the evidence, selecting relevant documents, data extraction, validation of findings, synthesising and refining programme theory. This strategy may help to describe potential consequences resulting from changes in context and their interactions with mechanisms. Initial theories will be refined throughout the process by the local reference panel, comprised of eight key intervention stakeholders, knowledge users such as healthcare professionals and an expert panel. Ethical approval is not required for this rapid realist review.

Conclusion: It is anticipated that the final programme theory will help to explain how QC-Ms work in practice; for whom, why and in what circumstances. Findings of this review could help to give insights into realism as a framework and how nursing and midwifery QC-Ms have been implemented previously.
The potential for linking cohort participants to official criminal records: a pilot study using the Avon Longitudinal Study of Parents and Children (ALSPAC)
Authors: Boyd Andy , Teyhan Alison , Cornish Rosie P. , Croft Jazz , Thomas Richard , Brennan Iain , Macleod John
Published: November 2020

Introduction: Linking longitudinal cohort resources with police-recorded records of criminal activity has the potential to inform public health style approaches and may reduce potential sources of bias from self-reported criminal data collected by cohort studies. A pilot linkage to police records in the Avon Longitudinal Study of Parents and Children (ALSPAC) allows us to consider the acceptability of this linkage, its utility as a data resource, differences in self-reported crime according to consent status for data linkage, and the appropriate governance mechanism to support such a linkage.

Methods: We carried out a pilot study that linked data from the ALSPAC birth cohort to Ministry of Justice (MoJ) records on criminal cautions and convictions. This pilot was conducted on a fully anonymous basis, meaning we cannot link the identified records to any participant or the wider information within the dataset. Using ALSPAC data, we used summary statistics to investigate differences in self-reported criminal activity according to socio-economic background and consent status. We used MoJ records to identify the geographic and temporal concentration of criminality in the ALSPAC cohort.

Results: We found that the linkage appears acceptable to participants (4% of the sample opted out), levels of criminality are high enough to support research and that the majority of crimes occurred in Avon & Somerset (the policing area local to ALSPAC). Both those who opted out of linkage or did not respond to consent requests had higher levels of self-reported criminal behaviour compared to participants who provided explicit consent.

Conclusions: These findings suggest that data linkage in ALSPAC provides opportunities to study criminal behaviour and that linked individual-level records can provide robust research in the area. Our findings also suggest the potential for bias when only using samples that have explicitly consented to data linkage, highlighting the limitations of opt-in consent strategies.
Recent advances in understanding RNA polymerase II structure and function
Authors: Reines Daniel
Published: November 2020

More than 50 years after the identification of RNA polymerase II, the enzyme responsible for the transcription of most eukaryotic genes, studies have continued to reveal fresh aspects of its structure and regulation. New technologies, coupled with years of development of a vast catalog of RNA polymerase II accessory proteins and activities, have led to new revelations about the transcription process. The maturation of cryo-electron microscopy as a tool for unraveling the detailed structure of large molecular machines has provided numerous structures of the enzyme and its accessory factors. Advances in biophysical methods have enabled the observation of a single polymerase’s behavior, distinct from work on aggregate population averages. Other recent work has revealed new properties and activities of the general initiation factors that RNA polymerase II employs to accurately initiate transcription, as well as chromatin proteins that control RNA polymerase II’s firing frequency, and elongation factors that facilitate the enzyme’s departure from the promoter and which control sequential steps and obstacles that must be navigated by elongating RNA polymerase II. There has also been a growing appreciation of the physical properties conferred upon many of these proteins by regions of each polypeptide that are of low primary sequence complexity and that are often intrinsically disordered. This peculiar feature of a surprisingly large number of proteins enables a disordered region of the protein to morph into a stable structure and creates an opportunity for pathway participants to dynamically partition into subcompartments of the nucleus. These subcompartments host designated portions of the chemical reactions that lead to mRNA synthesis. This article highlights a selection of recent findings that reveal some of the resolved workings of RNA polymerase II and its ensemble of supporting factors.
Clinical Guideline Highlights for the Hospitalist: Therapeutic Monitoring of Vancomycin
Authors: Murphy Mark , Girdwood Sonya Tang , Scheetz Marc H
Published: November 2020

GUIDELINE TITLE

Therapeutic monitoring of vancomycin for serious methicillin‐resistant Staphylococcus aureus infections: A revised consensus guideline and review by the American Society of Health‐System Pharmacists, the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the Society of Infectious Diseases Pharmacists

RELEASE DATE

Online: March 19, 2020

PRIOR VERSION

2009

DEVELOPERS

American Society of Health‐System Pharmacists (ASHP), the Infectious Diseases Society of America (IDSA), the Pediatric Infectious Diseases Society (PIDS), and the Society of Infectious Diseases Pharmacists (SIDP)

FUNDING SOURCE

ASHP, IDSA, PIDS, SIDP

TARGET POPULATION

Adults, children, and neonates treated for documented or presumed methicillin‐resistant Staphylococcus aureus infection
Safety Assessment of a Noninvasive Respiratory Protocol for Adults With COVID‐19
Authors: III William E Soares , Schoenfeld Elizabeth M , Visintainer Paul , Elia Tala , Medarametla Venkatrao , Schoenfeld David A , Deutsch Ashley , Salvador Doug , Dietzen Diane , Tidswell Mark A , II Peter A DePergola , Marie Peter St. , Westafer Lauren M
Published: November 2020

As evidence emerged supporting noninvasive strategies for coronavirus disease 2019 (COVID‐19)–related respiratory distress, we implemented a noninvasive COVID‐19 respiratory protocol (NCRP) that encouraged high‐flow nasal cannula (HFNC) and self‐proning across our healthcare system. To assess safety, we conducted a retrospective chart review evaluating mortality and other patient safety outcomes after implementation of the NCRP protocol (April 3, 2020, to April 15, 2020) for adult patients hospitalized with COVID‐19, compared with preimplementation outcomes (March 15, 2020, to April 2, 2020). During the study, there were 469 COVID‐19 admissions. Fewer patients underwent intubation after implementation (10.7% [23 of 215]), compared with before implementation (25.2% [64 of 254]) (P < .01). Overall, 26.2% of patients died (24% before implementation vs 28.8% after implementation; P = .14). In patients without a do not resuscitate/do not intubate order prior to admission, mortality was 21.8% before implementation vs 21.9% after implementation. Overall, we found no significant increase in mortality following implementation of a noninvasive respiratory protocol that decreased intubations in patients with COVID‐19.
Leadership in a crisis: doing things differently, doing different things
Authors: Paixão Graça , Mills Chloe , McKimm Judy , Hassanien Mohammed A , Al-Hayani Abdulmonem A
Published: November 2020

This article summarises the findings from a review of publications related to healthcare leadership that were published during the first wave of the COVID-19 crisis in 2020. The review discusses a range of strategies for leaders to adopt in challenging situations and identifies three aspects of leadership which are considered essential when leading teams during a crisis: 1) communication, 2) decision making and 3) mental health and wellbeing. This article identifies key principles for each of these three aspects and provides practical tips for how leaders can use the lessons learned from the pandemic in their own contexts.
Families experiencing homelessness: Concerns and solutions
Authors: Cockman Charlotte , Cockman Sarah
Published: November 2020

This article explains how a clinician-led third sector organisation in Greater Manchester has issued a call to action requiring healthcare providers and service commissioners to adapt to improve health outcomes
Two new species of the genus Cohicaleyrodes Bink-Moenen, 1983 (Hemiptera: Aleyrodidae) from India

Authors: SUNDARARAJ RAMACHANDRAN , VIMALA DURAISAMY
Published: November 2020

Two new aleyrodids of the genus Cohicaleyrodes Bink-Moenen, 1983 viz., C. grewiae sp. nov. on Grewia tiliifolia Vahl (Malvaceae) and C. ixorae sp. nov. on Ixora nigricans R.Br. ex Wight & Arn. (Rubiaceae) are described and illustrated. List for all known species from India and a workable key to the Indian specie of the genus Cohicaleyrodes are given. The descriptions of two new species bring the number of known Indian species of Cohicaleyrodes to ten. Key words: Taxonomy, whitefly, Grewia tiliifolia, Ixora nigricans
Contribution to the Iranian Buprestidae (Coleoptera) with one genus new for the country

Authors: GHAHARI HASSAN , VOLKOVITSH MARK G.
Published: November 2020

This paper deals with additional data on Iranian Buprestidae (Coleoptera) which appeared after the publication of the Annotated Catalogue of Iranian Buprestidae. Sternocera (Sternocera) chrysis Fabricius, 1775 as a new country record, and 22 species from 11 genera published by other authors are listed for the fauna of Iran. Totally, 502 species and subspecies from 41 genera belonging to 20 tribes and six subfamilies are reported from Iran so far. Key words: Buprestidae, new record, fauna, catalogue, Iran
Devoted work without limits? Activities and premises of home visit work at the margins of community care
Authors: Juhila Kirsi , Hansen Löfstrand Cecilia , Raitakari Suvi
Published: November 2020

Community care provided through home visits is an increasingly common way to respond to adult citizens’ complex needs due to, for example, mental health and substance abuse problems. This study explores the activities and core premises that this work entails. The data contain six focus group interviews with practitioners in five service settings in Finland and Sweden at the margins of community care. Through a two-stage coding process, 11 activities and three premises – situationality, boundlessness and empathy – were identified. The findings show that home visit work at the margins of community care is comprehensive and flexible, requiring reflexivity.
Deep-learning super-resolution light-sheet add-on microscopy (Deep-SLAM) for easy isotropic volumetric imaging of large biological specimens
Authors: Zhao Fang , Zhu Lanxin , Fang Chunyu , Yu Tingting , Zhu Dan , Fei Peng
Published: November 2020

Isotropic 3D histological imaging of large biological specimens is highly desired but remains highly challenging to current fluorescence microscopy technique. Here we present a new method, termed deep-learning super-resolution light-sheet add-on microscopy (Deep-SLAM), to enable fast, isotropic light-sheet fluorescence imaging on a conventional wide-field microscope. After integrating a minimized add-on device that transforms an inverted microscope into a 3D light-sheet microscope, we further integrate a deep neural network (DNN) procedure to quickly restore the ambiguous z-reconstructed planes that suffer from still insufficient axial resolution of light-sheet illumination, thereby achieving isotropic 3D imaging of thick biological specimens at single-cell resolution. We apply this easy and cost-effective Deep-SLAM approach to the anatomical imaging of single neurons in a meso-scale mouse brain, demonstrating its potential for readily converting commonly-used commercialized 2D microscopes to high-throughput 3D imaging, which is previously exclusive for high-end microscopy implementations.
Fluorescent bacterial biosensor E. coli/pTdcR-TurboYFP sensitive to terahertz radiation
Authors: Serdyukov Danil S. , Goryachkovskaya Tatiana N. , Mescheryakova Irina A. , Kuznetsov Sergei A. , Popik Vasiliy M. , Peltek Sergey E.
Published: November 2020

A fluorescent biosensor E. coli/pTdcR-TurboYFP sensitive to terahertz (THz) radiation was developed via transformation of Escherichia coli (E. coli) cells with plasmid, in which the promotor of the tdcR gene controls the expression of yellow fluorescent protein TurboYFP. The biosensor was exposed to THz radiation in various vessels and nutrient media. The threshold and dynamics of fluorescence were found to depend on irradiation conditions. Heat shock or chemical stress yielded the absence of fluorescence induction. The biosensor is applicable to studying influence of THz radiation on the activity of tdcR promotor that is involved in the transport and metabolism of threonine and serine in E. coli.
Quantitative phase retrieval with low photon counts using an energy resolving quantum detector
Authors: Vazquez Ivan , Harmon Ian E. , Luna J. C. Rodriguez , Das Mini
Published: November 2020

X-ray phase contrast imaging (PCI) combined with phase retrieval has
the potential to improve soft-material visibility and discrimination.
This work examined the accuracy, image quality gains, and robustness
of a spectral phase retrieval method proposed by our group.
Spectroscopic PCI measurements of a physical phantom were obtained
using state-of-the-art photon-counting detectors in combination with a
polychromatic x-ray source. The phantom consisted of four poorly
attenuating materials. Excellent accuracy was demonstrated in
simultaneously retrieving the complete refractive properties
(photoelectric absorption, attenuation, and phase) of these materials.
Approximately 10 times higher SNR was achieved in retrieved images
compared to the original PCI intensity image. These gains are also
shown to be robust against increasing quantum noise, even for
acquisition times as low as 1 s with a low-flux microfocus x-ray tube
(average counts of 250 photons/pixels). We expect that this spectral
phase retrieval method, adaptable to several PCI geometries, will
allow significant dose reduction and improved material discrimination
in clinical and industrial x-ray imaging applications.
High-energy diode-pumped alexandrite amplifier development with applications in satellite-based lidar
Authors: Coney Alexander T. , Damzen Michael J.
Published: November 2020

Efficient, wavelength-tunable diode-pumped alexandrite laser systems
offer the potential for a more versatile, satellite-based lidar source
compared to fixed wavelength Nd:YAG systems and non-space compliant
lamp-pumped alexandrite. In this paper, we develop a strategy to
enable the high-energy operation required for atmospheric lidar based
on an efficient diode-pumped master oscillator power amplifier (MOPA)
system design. A novel multipass “diamond” slab amplifier geometry is
introduced alongside the experimental results of the world’s first
diode-pumped alexandrite amplifier producing a gain of 2.13 in a
demonstration system. A diode-pumped

Q

-switched alexandrite oscillator is
presented with a record-highest pulse energy of 3.80 mJ. Detailed
optimization of a two-stage amplifier design is studied numerically
and maximized with temperature, wavelength, and pump pulse duration to
produce 50 mJ pulse energy. This forms part of an optimized
alexandrite MOPA design capable of high pulse energy, showing the
future potential of diode-pumped alexandrite for satellite-based
atmospheric lidar.
Dark-field ghost imaging
Authors: Dou Ling-Yu , Cao De-Zhong , Gao Lu , Song Xin-Bing
Published: November 2020

Ghost imaging is a promising technique for shape reconstruction using two spatially correlated beams: one beam interacts with a target and is collected with a bucket detector, and the other beam is measured with a pixelated detector. However, orthodox ghost imaging always provides unsatisfactory results for unstained samples, phase objects, or highly transparent objects. Here we present a dark-field ghost imaging technique that can work well for these “bad” targets. The only difference from orthodox ghost imaging is that the bucket signals rule out the target’s unscattered beam. As experimental proof, we demonstrate images of fine copper wires, quartz fibers, scratched and damaged glass plates, a pure phase object, and biospecimens.
Inverse design of optical needles with central zero-intensity points by artificial neural networks
Authors: Xin Wei , Zhang Qiming , Gu Min
Published: November 2020

Optical needles with central zero-intensity points have attracted much attention in the field of 3D super-resolution microscopy, optical lithography, optical storage and Raman spectroscopy. Nevertheless, most of the studies create few types of optical needles with central zero-intensity points based on the theory and intuition with time-consuming parameter sweeping and complex pre-select of parameters. Here, we report on the inverse design of optical needles with central zero-intensity points by dipole-based artificial neural networks (DANNs), permitting the creation of needles which are close to specific length and amplitude. The resolution of these optical needles with central zero-intensity points is close to axial diffraction limit (∼1λ). Additionally, the DANNs can realize the inverse design of several types on-axis distributions, such as optical needles and multifocal distributions.
Scanning two-photon continuous flow lithography for the fabrication of multi-functional microparticles
Authors: Chizari Samira , Udani Shreya , Farzaneh Amin , Stoecklein Daniel , Carlo Dino Di , Hopkins Jonathan B.
Published: November 2020

In this work, we demonstrate the high-throughput fabrication of 3D microparticles using a scanning two-photon continuous flow lithography (STP-CFL) technique in which microparticles are shaped by scanning the laser beam at the interface of laminar co-flows. The results demonstrate the ability of STP-CFL to manufacture high-resolution complex geometries of cell carriers that possess distinct regions with different functionalities. A new approach is presented for printing out-of-plane features on the microparticles. The approach eliminates the use of axial scanning stages, which are not favorable since they induce fluctuations in the flowing polymer media and their scanning speed is slower than the speed of galvanometer mirror scanners.
Time multiplexing super-resolved imaging without a priori knowledge of the spatial distribution of the encoding structured illumination
Authors: Chen Gal , Sanjeev Abhijit , Trivedi Vismay , Garcia Javier , Rubio Ricardo , Zalevsky Zeev
Published: November 2020

Time multiplexing is a super-resolution technique that sacrifices time to overcome the resolution reduction obtained because of diffraction. There are many super resolution methods based on time multiplexing, but all of them require a priori knowledge of the time changing encoding mask, which is projected on the object and used to encode and decode the high-resolution information. In this paper, we present a time multiplexing technique that does not require the a priori knowledge on the projected encoding mask. First, the theoretical concept of the technique is demonstrated; then, numerical simulations and experimental results are presented.
Joint linear and nonlinear noise monitoring techniques based on spectrum analysis
Authors: Lu Jianing , Zhou Gai , Zhou Jing , Lu Chao
Published: November 2020

As one of the key indicators of signal quality in fiber communication systems, optical signal-to-noise ratio (OSNR) needs to be accurately monitored to ensure reliable network planning, operation, and reconfiguration. OSNR monitoring techniques considering only accumulated amplified spontaneous emission (ASE) noise are no longer suitable for dispersion unmanaged long-haul and dense wavelength division multiplexing (WDM) systems, where the contribution of fiber nonlinearity to total SNR cannot be neglected. In this paper, we propose a modulation-format-transparent, accurate joint linear and nonlinear noise monitoring scheme based on calculation of correlation between two spectral components at the upper and lower sideband of the signal spectrum. Different characteristics of flat linear noise spectrum and non-flat nonlinear noise spectrum are used to distinguish the influences on the correlation value from both noise sources. Simulation results show that the proposed scheme can accurately monitor SNRlinear and SNRnonlinear within a wide launch power range from −5 dBm to 5 dBm per channel for multi-channel WDM systems with a 915-km single mode fiber (SMF) link. The performance of the proposed scheme is further experimentally verified in up-to-7 channel WDM systems over a 915 km SMF link.
Ultra-high quality graphene perfect absorbers for high performance switching manipulation
Authors: Zhong Haozong , Liu Zhengqi , Liu Xiaoshan , Fu Guolan , Liu Guiqiang , Chen Jing , Tang Chaojun
Published: November 2020

Wavelength-selective light absorption and the related switching operations are highly desired in optical devices. Herein, we report the approach for ultra-high quality (Q) graphene perfect optical absorption, which possesses impressive performance in switching manipulation. A record-breaking Q-factor (up to 105) is observed, suggesting one or two orders of magnitude larger than that of the conventional graphene absorbers. The ultra-low external leakage loss rate of quasi-bound states in the continuum (BIC) resonator and the ultra-low intrinsic absorption loss rate in the resonant mode volume are the main contributions for the ultra-high Q perfect absorption. By introducing a Kerr nonlinear medium, spectral relative intensity can be changed from 0 to 100% when an ultra-low pump light with the intensity of only 5 kW cm−2 is used. After a rather slight tuning of the refractive index (Δn = 5×10−4) for the resonators, the absorption contrast ratio reaches 31 dB. The switching related spectral wavelength shift sensitivity is up to 915 nm/RIU and the figure of merit (FOM) is 50 833. These features confirm the ultra-high tunability and switching manipulation. It is believed that the ultra-high Q-factor absorption offered by all-dielectric configuration provides plentiful potential applications for graphene-based devices in the all-optical switch, modulator, notch filter, etc.
Beyond the 2D limit: étendue-squeezing line-focus solar concentrators
Authors: Johnsen Håkon J. D. , Aksnes Astrid , Torgersen Jan
Published: November 2020

Line-focus solar concentrators are commonly designed by extruding a two-dimensional concentrator in the third dimension. For concentration in air, these concentrators are, by the nature of their design, limited by the two-dimensional solar concentration limit of

. This limit is orders of magnitude lower than the

concentration limit for three-dimensional solar concentrators. Through the use of étendue squeezing, we conceptually show that it is possible to design line-focus solar concentrators beyond this 2D limit. This allows a concentrator to benefit from a line focus suitable for heat extraction through a tubular receiver, while reaching concentration ratios and acceptance angles previously unseen for line-focus concentrators. We show two design examples, achieving simulated

concentration and

concentration ratios, with a

acceptance angle. For comparison, the 2D concentration limit is

at this acceptance angle. Étendue-squeezing line-focus solar concentrators, combined with recent developments in tracking integration, may enable the development of a new class of concentrated solar power systems.
Cryogenic microwave-to-optical conversion using a triply resonant lithium-niobate-on-sapphire transducer
Authors: McKenna Timothy P. , Witmer Jeremy D. , Patel Rishi N. , Jiang Wentao , Van Laer Raphaël , Arrangoiz-Arriola Patricio , Wollack E. Alex , Herrmann Jason F. , Safavi-Naeini Amir H.
Published: November 2020

Quantum networks are likely to have a profound impact on the way we compute and communicate in the future. In order to wire together superconducting quantum processors over kilometer-scale distances, we need transducers that can generate entanglement between the microwave and optical domains with high fidelity. We present an integrated electro-optic transducer that combines low-loss lithium niobate photonics with superconducting microwave resonators on a sapphire substrate. Our triply resonant device operates in a dilution refrigerator and converts microwave photons to optical photons with an on-chip efficiency of

6.6
×

10

−
6

and a conversion bandwidth of 20 MHz. We discuss design trade-offs in this device, including strategies to manage acoustic loss, and outline ways to increase the conversion efficiency in the future.
Nonlinear and low-loss tantalum pentoxide based micro-ring resonator by ion-assisted electron-beam deposition
Authors: Chiu Yi-Jen , Yan Fu-Yan , Liu Jia-Wei , Lan Jia-Chi , Wang Te-Keng , Lin Chao-Hong , Chen Sung-Wen Huang , Kuo Hao-Chung , Wang Huai-Yung , Cheng Chih-Hsien , Lin Gong-Ru , Shih Min-Hsiung , Hung Yung-Jr , Lee Chao-Kuei
Published: November 2020

Tantalum pentoxide (Ta2O5) is a promising material for optical waveguide applications of photonics integration due to its excellent linear and nonlinear optical properties, such as high refractive index, large bandgap, and high nonlinearity. The quality of thin film deposition will then be critical for realizing optical waveguide devices and modules. In this work, an ion-assisted electron-beam evaporation system has been used to deposit such thin film. As low as 0.73 nm thickness roughness has been demonstrated in a 700 nm thick film, indicating it as a candidate for fabricating a low-loss waveguide. An optical waveguide-based ring resonator was made for examining the optical waveguide performance. Through the flat surface morphology, a low propagation loss of 1.4 dB/cm with an unloaded quality factor of 3 × 105 ring resonance has been realized. The nonlinear index of refraction (n2) in as-deposited Ta2O5 film was found to be in an order of magnitude of 10−14 cm2/W, which was also confirmed by both Z-scan technique and all-optical modulation technique. By such high bandgap properties, a nonlinear absorption threshold of few TW/cm2 was also observed for the first time. The measured device performances are comparable to the state-of-the-art results from up-to-date counterparts.
Effect of pemafibrate (K-877), a novel selective peroxisome proliferator-activated receptor α modular (SPPARMα), in atherosclerosis model using low density lipoprotein receptor knock-out swine with balloon injury
Authors: Konishi Hirokazu , Miyauchi Katsumi , Onishi Akira , Suzuki Shunichi , Fuchimoto Daiichiro , Shitara Jun , Endo Hirohisa , Wada Hideki , Doi Shinichiro , Naito Ryo , Ogita Manabu , Dohi Tomotaka , Kasai Takatoshi , Daida Hiroyuki
Published: November 2020

Background

Peroxisome proliferator-activated receptor α (PPARα) is a nuclear receptor that has key roles of lipid metabolism and inflammation. The PPARα may affects the initiation and progression of atherosclerosis by reducing inflammatory responses. Pemafibrate (K-877) is a novel selective PPARα modulator (SPPARMα), which was designed to possess higher PPARα potency and selectivity than existing PPARα agonists. The aim of this study is to evaluate the effect of pemafibrate on vascular response in coronary atherosclerosis model using low density lipoprotein receptor knock-out (LDLR-KO) pigs with balloon injury.

Methods and results

Ten LDLR-KO pigs were randomly allocated to two groups [pemafibrate (n = 5) and control (n = 5)] and fed with a diet containing 2.0% cholesterol and 20% lard throughout the study. Balloon injury was created in 40 coronary segments two weeks after starting the oral administration of pemafibrate or placebo. Necropsy was conducted 8 weeks later. Coronary artery sections were reviewed to evaluate lesion progression and the mRNA expression levels for C-Jun, NFκ B, CCL2, CCR7, CD163 and MMP9 determined using real-time RT-PCR. LDL cholesterol at baseline was about 700 mg/dL. The mean ratio of macrophages to plaque area was significantly lower in pemafibrate group compared with control one (7.63±1.16 vs 14.04±4.51, P = 0.02) whereas no differences were observed in intimal area between groups. The mRNA levels of C-Jun, NFκB and MMP9 were significantly decreased in pemafibrate group.

Conclusions

Pemafibrate was associated with inhibition of inflammatory responses in coronary artery atherosclerosis model using LDLR-KO swine with balloon injury.
Employee burnout and positive dimensions of well-being: A latent workplace spirituality profile analysis
Authors: Dal Corso Laura , De Carlo Alessandro , Carluccio Francesca , Colledani Daiana , Falco Alessandra
Published: November 2020

In recent years, a new and promising construct has attracted the attention of organizational research: Workplace spirituality. To investigate the role of workplace spirituality in organizational contexts, two studies were carried out. Study 1 explored the mediation role of workplace spirituality in the relationship between positive supervisor behaviors and employee burnout. Results showed that workplace spirituality strongly contributes to reduce burnout and mediates the effect of supervisor integrity in reducing this threat. Study 2 considered the relationships of workplace spirituality with positive affectivity, resilience, self-efficacy, and work engagement. In particular, workplace spirituality profiles were investigated through latent profile analysis (LPA). Findings showed that workplace spirituality is related to higher positive affectivity, resilience, self-efficacy, and work engagement. In contrast, a workplace spirituality profile characterized by a low-intensity spiritual experience is associated with higher negative feelings. The practical implications of these findings are discussed.
Association of SARS-CoV-2 genomic load trends with clinical status in COVID-19: A retrospective analysis from an academic hospital center in New York City
Authors: Zacharioudakis Ioannis M. , Zervou Fainareti N. , Prasad Prithiv J. , Shao Yongzhao , Basu Atreyee , Inglima Kenneth , Weisenberg Scott A. , Aguero-Rosenfeld Maria E.
Published: November 2020

The Infectious Diseases Society of America has identified the use of SARS-CoV-2 genomic load for prognostication purposes as a key research question. We designed a retrospective cohort study that included adult patients with COVID-19 pneumonia who had at least 2 positive nasopharyngeal tests at least 24 hours apart to study the correlation between the change in the genomic load of SARS-CoV-2, as reflected by the Cycle threshold (Ct) value of the RT-PCR, with change in clinical status. The Sequential Organ Failure Assessment (SOFA) score was used as a surrogate for patients’ clinical status. Among 457 patients with COVID-19 pneumonia between 3/31/2020-4/10/2020, we identified 42 patients who met the inclusion criteria. The median initial SOFA score was 2 (IQR 2–3). 20 out of 42 patients had a lower SOFA score on their subsequent tests. We identified a statistically significant inverse correlation between the change in SOFA score and change in the Ct value with a decrease in SOFA score by 0.05 (SE 0.02; p<0.05) for an increase in Ct values by 1. This correlation was independent of the duration of symptoms. Our findings suggest that an increasing Ct value in sequential tests may be of prognostic value for patients diagnosed with COVID-19 pneumonia.