bluuebunny/crossref_metadata_2025 huggingface dataset:
Soaking of Autologous Tendon Grafts in Vancomycin Before Implantation Does Not Lead to Tenocyte Cytotoxicity
Authors: Xiao Michelle , Leonardi Erika A. , Sharpe Orr , Sherman Seth L. , Safran Marc R. , Robinson William H. , Abrams Geoffrey D.
Published: September 2020

Background:

Surgical site infections (SSIs) after anterior cruciate ligament (ACL) reconstruction procedures are an unfortunate complication. Soaking grafts in vancomycin before implantation has been reported to reduce the incidence of postoperative SSI after ACL reconstruction. There is potential for vancomycin to compromise graft integrity because of tenocyte toxicity.

Purpose:

To examine the in vitro toxicity of varying doses of vancomycin on human tenocytes.

Study Design:

Controlled laboratory study.

Methods:

Human patellar tenocytes were isolated and expanded in vitro. Tenocytes in culture were exposed to vancomycin at 5 different concentrations (400, 1600, 3200, 6400, and 12,800 μg/mL) and 3 time intervals (2, 6, and 24 hours). The control for all series was tenocyte exposure to only culture medium for each time interval. After treatment, a 10% Cell Counting Kit-8 solution in cellular growth medium was applied to the cells to examine cytotoxicity. A live/dead assay was used to assess tenocyte viability through fluorescence microscopy and flow cytometry. Results were analyzed statistically using multivariable logistic regression models with Tukey honest significant difference post hoc tests.

Results:

Vancomycin did not cause significant changes in tenocyte viability after 2 and 6 hours of incubation at any concentration between 0 and 12,800 µg/mL. Incubation with vancomycin for 24 hours led to a significant decrease in cell viability at higher concentrations.

Conclusion:

Tenocytes derived from human patellar tendons exposed to relatively high concentrations of vancomycin for short periods of time do not demonstrate significant cell death and toxicity.

Clinical Relevance:

Exposing tendons to vancomycin for a short period of time, such as before ACL reconstruction, is not likely to cause tenocyte toxicity because of vancomycin administration.
An overview of the key principles and guidelines in the management of pelvic fractures
Authors: Mostafa Ahmed M H A M , Kyriacou Harry , Chimutengwende-Gordon Mukai , Khan Wasim S
Published: September 2020

Pelvic fractures are complex injuries with a range of different presentations depending on the mechanism of trauma. Due to the morbidity and mortality of pelvic fractures, patients require thorough investigation and timely management with multidisciplinary input. Various surgical and non-surgical techniques can be used to treat pelvic fractures, as well as any associated visceral injuries. Following repair, it is important to remain vigilant for postoperative complications such as infection, sexual and urinary dysfunction, chronic pain and adverse psychological health. This article summarises the relevant UK guidance and literature and presents them in a format that follows the patient’s journey. In doing so, it highlights the key perioperative factors that need to be considered in cases of pelvic fracture.
COVID-19: Indian Society of Neuroradiology (ISNR) Consensus Statement and Recommendations for Safe Practice of Neuroimaging and Neurointerventions
Authors: Sebastian Leve Joseph Devarajan , Ahuja Chirag , Sekar Sabarish , Senthilvelan Santhakumar , Kulanthaivelu Karthik , Lanka Vivek , Goel Vinay , Mohapatra Sarita , Jain Chirag , Senthilkumaran S. , Garg Ajay , Balasundaram Parthiban , Kumar Ajay , Kapil Aarti , Kesavadas Chandrasekharan , Gupta Vivek
Published: September 2020

The ongoing COVID-19 pandemic has forced every radiology set-up to evolve and formulate guidelines for day-to-day functioning. The sub-speciality of neuroradiology, both diagnostic and neuro-intervention, forms a very important part of any radiology or ‘neuro-care’ set-up. The present document is a consensus statement of the Indian Society of Neuroradiology, prepared after reviewing the available data and working experience. It scientifically tries to answer many questions faced by neuroradiologists everyday in practice. It encompasses simple things such as which patients need to be imaged, what precautions are essential, the work-flows, cleaning of radiology equipment, how to carry out neuro-interventions in COVID-suspect patients, and what procedures/tests to avoid, or their alternatives, to minimise the spread of COVID infection both to the patients and health care personnel. As radiology set-ups can be large, every sub-speciality may have certain precautions which will not be covered in general guidelines, and this document tries to answer those for neuroradiologists. Carefully evolved Standards of Operating Procedure (SOPs) and guidelines are the need of the hour to guide in providing uninterrupted and adequate services to the needy without compromising the safety of the specialised work force and facilities involved.
Computational framework for detection of subtypes of neuropsychiatric disorders based on DTI-derived anatomical connectivity
Authors: Chen Rong , Lee Kyunghun , Herskovits Edward H
Published: September 2020

Many brain disorders – such as Alzheimer’s disease, Parkinson’s disease, schizophrenia and autism – are heterogeneous, that is, they may have several subtypes. Traditionally, clinicians have identified subtypes, such as subtypes of psychosis, using clinical criteria. Neuroimaging has the potential to detect subtypes based on objective biomarker-based criteria; however, there are no studies that evaluate the application of combining unsupervised machine learning and anatomical connectivity analysis to accomplish this goal. We propose a computational framework to detect subtypes based on anatomical connectivity computed from diffusion tensor imaging data, in a data-driven and fully automated way. The proposed method exhibits excellent performance on simulated data. We also applied this approach to a real-world dataset: the Nathan Kline Institute data set. The Nathan Kline Institute study consists of 137 normal adult subjects (mean age 41 years (standard deviation 18), male/female 85/52). We examined the association between detected subtypes and the impulsive behavior scale. We found that a subtype characterized by lower connectivity scores was associated with a higher positive urgency score; positive urgency is a vulnerability marker for drug addiction. The top-ranked connections characterizing subtypes involve several brain regions, including the anterior cingulate gyrus, median cingulate gyrus, thalamus, superior frontal gyrus (medial), middle frontal gyrus (orbital part), inferior frontal gyrus (triangular part), superior frontal gyrus, precuneus and putamen. The proposed framework is extendable, and can be used to detect subtypes from other features, including clinical and genomic biomarkers.
Sterilization regret in India: Is quality of care a matter of concern?
Authors: Bansal Anjali , Dwivedi Laxmi Kant
Published: September 2020

Background

According to United Nations, 19% of females in the world relied only on the permanent method of family planning, with 37% in India according to NFHS-4. Limited studies tried to measure the sterilization regret, and its correlated factors. The study tried to explore the trend of sterilization regret in India from 1992 to 2015 and to elicit the determining effects of various factors on sterilization regret, especially in context to perceived quality of care in the sterilization operations and type of providers.

Data and methods

The pooled data from NFHS-1, NFHS-3 and NFHS-4 was used to explore the regret by creating interaction between time and all the predictors. Predicted probabilities were calculated to show the trend of sterilization regret amounting to quality of care, type of health provider at the three time periods.

Results

The sterilization regret was increased from 5 % in NFHS-1 to 7 % in NFHS-4. According to NFHS-4, for those whose sterilization was performed in private health facility the regret was found to be less (OR-0.937; 95% CI- (0.882–0.996)) compared to public health facility. Also, the results show a two-fold increase in regret when women reported bad quality of care. The results from predicted probabilities provide enough evidence that the regret due to bad quality of care in sterilization operation had increased with each subsequent round of NFHS.

Conclusion

Many socio-economic and demographic factors have influenced the regret, but the poor quality of care contributed maximum to the regret from 1992 to 2015. The health facilities have seriously strayed from improving the health and well-being of women in providing the family planning methods. In addition, to public facilities, the regret amounting to private facilities have also increased from NFHS-1 to 4. The quality of care provided in the family planning operation should be standardized in every hospital to strengthen the health systems in the country. The couple should be motivated to adopt more of spacing methods.
Evaluation of the prognostic value of the neutrophil to lymphocyte ratio, lactate dehydrogenase enzyme, and proteinuria in patients with acute pancreatitis admitted at Assiut University Hospitals and its correlation with Ranson’s criteria scoring system
Authors: Ahmed Lobna Abdel-wahid , Kelani Abd-Alla Ismail Ali , Nasr-Allah Fady Refaat Edwar
Published: September 2020

Background

Acute pancreatitis is a relatively common acute medical presentation that may progress beyond the pancreas to cause multi-organ failure or death. It is associated with high morbidity and mortality with mortality rates changing little in the past few decades despite advances in intensive care and surgical management. Early evaluation of acute pancreatitis severity is essential to allow the clinician to predict the patient’s clinical course, estimate the prognosis, determine the need for intensive care unit admission, and prevent complications. So, the purpose of our study is to evaluate the prognostic value of the neutrophil to lymphocyte ratio, lactate dehydrogenase enzyme, and proteinuria in patients with acute pancreatitis and its correlation with Ranson’s criteria scoring system as new, rapid, and easy parameters to predict severity of acute pancreatitis.

Results

The mean age of patients in years was 47.97, and the median was 52 with a range of ages between 18 and 87; 38% of the patients included were males, and 61% were females. The mean Ranson’s score was 2.77 ± 1.4, and the median was 3 with a range of 0–6; 44.5% of patients included have low severity, 42.4% have mild severity, and 13.1% of patients have high severity. Neutrophil to lymphocyte ratio both at the time of admission and after 48 h of admission was significantly increasing with an increase in disease severity with a P value of < 0.001 that was statistically significant. Lactate dehydrogenase enzyme at the time of admission was also significantly increasing with diseased severity with a P value of 0.001 that was statistically significant and the same for lactate dehydrogenase enzyme level after 48 h of admission with a P value of 0.002 that was also statistically significant. Proteinuria is positive only in 15.2% of patients and with the same result after 48 h of admission.

Conclusion

The neutrophil to lymphocyte ratio gives a rapid impression of the extent of the inflammatory process, and it can effectively predict severity at the time of admission and even after 48 h of admission and can also differentiate between patients with mild and severe acute pancreatitis in both calcular and non-calcular cause-dependent acute pancreatitis patients. Lactate dehydrogenase can be used to predict severity in calcular cause-dependent acute pancreatitis patients only at the time of admission and after 48 h of admission. Proteinuria in urine analysis on admission and after 48 h does not seem to be a reliable predictor for disease severity in acute pancreatitis.
Subclinical hepatitis C virus infection in Egyptian patients with rheumatic diseases: a multi-center study
Authors: Mahran Safaa Ali , Mohamed Alaa A. A. , Nigm Dalia A. , Rahma M. Z. A. Abu , Abd-Elsalam S. , Hamoud Hesham , Hamdy M. , Risha M. I. , Hamdy Ahmad , Abdelkareem Mohamed M. , Ghanem Saad , Hanafy Mohamed , Moshrif Abdelhafeez , Fehr A. , ElNouby Fatma H. , Osman A. , Hassanien Manal M.
Published: September 2020

Background

Hepatitis C virus (HCV) infection is highly prevalent in Egypt. It was found to be 7.0% in a study done in 2015. There are some studies on the prevalence of HCV in rheumatoid arthritis, but to our knowledge, no previous study was done to detect it in other rheumatologic diseases. This study aims at detecting the prevalence of subclinical HCV infection in Egyptian patients with different rheumatic diseases. In the current study, eight hundred and three patients with different rheumatic diseases collected from five—geographically different—Egyptian rheumatology departments were studied. Patients with known current or previous HCV infection were excluded from the study. Screening for the positive anti-HCV antibodies was done for all patients. Screening for the presence of HCV ribonucleic acid (RNA) was done in patients with positive serology by reverse transcriptase-polymerase chain reaction.

Results

In the studied population, 675 (84.1%) patients were women. The mean age [± SD] was 44.2 [± 12.9] years. Hepatitis C antibody positivity was found in 73 (9.1%) of the patients, while 67 (8.3%) were having positive HCV-RNA quantitative PCR tests. The highest prevalence of seropositive HCV was found in drug-induced vasculitis (DIV) and cryo-vasculitis (100%), while in RA, HCV antibodies and PCR were found to be positive in 9.1% and 8.3% of patients, respectively.

Conclusions

Detection of the presence of HCV infection in 9.1 % of the studied middle-aged Egyptian patients with rheumatologic conditions points to the importance of screening for HCV in such population for early detection and intervention especially for those patients that are planned to start biologic therapy.
Using a Chatbot to Assess Hereditary Cancer Risk
Authors: Welch Brandon M. , Allen Caitlin G. , Ritchie Jordon B. , Morrison Heath , Hughes-Halbert Chanita , Schiffman Joshua D.
Published: September 2020

PURPOSE

We developed a Web-based chatbot (ItRunsInMyFamily.com) to help individuals collect their family health history (FHx) and determine their risk for hereditary cancer. The purpose of the current study was to assess the characteristics of users and identify opportunities to improve the FHx collection tool.

METHODS

During Family Health History Month (November 2019) we launched an FHx campaign using social media advertisements to raise awareness about hereditary cancers and encourage individuals in the general population to use ItRunsInMyFamily to collect their FHx. Through this campaign, we were able to gather information about users and identify opportunities to improve the tool.

RESULTS

We reached 14,140 users in November 2019 through online marketing campaigns—Facebook, Google, previous ItRuns users, and Web site marketing. Of those, 3,204 completed the full FHx assessment and received risk recommendations. The campaign targeted women between age 40 and 60 years. Users came from 3,783 counties around the United States, 48 unique cancers were reported among probands, and 79 unique cancers were reported among family members, an average of two and a half cancers per family.

CONCLUSION

Our results demonstrate that it is possible to gather FHx information at the population level, with high levels of engagement and interest in the topic. There is room for future enhancements and improvements to ItRunsInMyFamily to broaden its reach and encourage individuals to learn about and record their health information.
A novel hypomorphic allele of Spag17 causes primary ciliary dyskinesia phenotypes in mice
Authors: Abdelhamed Zakia , Lukacs Marshall , Cindric Sandra , Omran Heymut , Stottmann Rolf W.
Published: September 2020

Primary ciliary dyskinesia (PCD) is a human condition of dysfunctional motile cilia characterized by recurrent lung infection, infertility, organ laterality defects and partially penetrant hydrocephalus. We recovered a mouse mutant from a forward genetic screen that developed many of the hallmark phenotypes of PCD. Whole-exome sequencing identified this primary ciliary dyskinesia only (Pcdo) allele to be a nonsense mutation (c.5236A>T) in the Spag17 coding sequence creating a premature stop codon (K1746*). The Pcdo variant abolished several isoforms of SPAG17 in the Pcdo mutant testis but not in the brain. Our data indicate differential requirements for SPAG17 in different types of motile cilia. SPAG17 is essential for proper development of the sperm flagellum and is required for either development or stability of the C1 microtubule structure within the central pair apparatus of the respiratory motile cilia, but not the brain ependymal cilia. We identified changes in ependymal ciliary beating frequency, but these did not appear to alter lateral ventricle cerebrospinal fluid flow. Aqueductal stenosis resulted in significantly slower and abnormally directed cerebrospinal fluid flow, and we suggest that this is the root cause of the hydrocephalus. The Spag17Pcdo homozygous mutant mice are generally viable to adulthood but have a significantly shortened lifespan, with chronic morbidity. Our data indicate that the c.5236A>T Pcdo variant is a hypomorphic allele of Spag17 that causes phenotypes related to motile, but not primary, cilia. Spag17Pcdo is a useful new model for elucidating the molecular mechanisms underlying central pair PCD pathogenesis in the mouse.

This article has an associated First Person interview with the first author of the paper.
Progenitor death drives retinal dysplasia and neuronal degeneration in a mouse model of ATRIP-Seckel syndrome
Authors: Matos-Rodrigues Gabriel E. , Tan Pedro B. , Rocha-Martins Maurício , Charlier Clara F. , Gomes Anielle L. , Cabral-Miranda Felipe , Grigaravicius Paulius , Hofmann Thomas G. , Frappart Pierre-Olivier , Martins Rodrigo A. P.
Published: September 2020

Seckel syndrome is a type of microcephalic primordial dwarfism (MPD) that is characterized by growth retardation and neurodevelopmental defects, including reports of retinopathy. Mutations in key mediators of the replication stress response, the mutually dependent partners ATR and ATRIP, are among the known causes of Seckel syndrome. However, it remains unclear how their deficiency disrupts the development and function of the central nervous system (CNS). Here, we investigated the cellular and molecular consequences of ATRIP deficiency in different cell populations of the developing murine neural retina. We discovered that conditional inactivation of Atrip in photoreceptor neurons did not affect their survival or function. In contrast, Atrip deficiency in retinal progenitor cells (RPCs) led to severe lamination defects followed by secondary photoreceptor degeneration and loss of vision. Furthermore, we showed that RPCs lacking functional ATRIP exhibited higher levels of replicative stress and accumulated endogenous DNA damage that was accompanied by stabilization of TRP53. Notably, inactivation of Trp53 prevented apoptosis of Atrip-deficient progenitor cells and was sufficient to rescue retinal dysplasia, neurodegeneration and loss of vision. Together, these results reveal an essential role of ATRIP-mediated replication stress response in CNS development and suggest that the TRP53-mediated apoptosis of progenitor cells might contribute to retinal malformations in Seckel syndrome and other MPD disorders.

This article has an associated First Person interview with the first author of the paper.
Recommendations of the Polish Sexological Society on medical care in transgender adults – position statement of the expert panel
Authors: Grabski Bartosz , Rachoń Dominik , Czernikiewicz Wiesław , Dulko Stanisław , Jakima Sławomir , Muldenr-Nieckowski Łukasz , Trofimiuk- Muldner Małgorzata , Baran Dorota , Dora Marta , Iniewicz Grzegorz , Mijas Magdalena , Stankiewicz Sylwia , Adamczewska-Stachura Milena , Mazurczak Anna
Published: September 2020

Próby ujednolicenia postępowania diagnostyczno-terapeutycznego wobec osób transpłciowych doświadczających dysforii płciowej po raz pierwszy podejmowane były w Polsce w latach osiemdziesiątych XX wieku. Nie zostały jednak uwieńczone publikacją w postaci odpowiednich wytycznych. Taki stan rzeczy był i wciąż jest źródłem odmiennej praktyki klinicznej realizowanej przez różnych specjalistów, którzy różnią się między innymi zakresem proponowanych badań diagnostycznych i kryteriami, które przyjmują jako przesłankę do wdrożenia medycznych działań afirmujących płeć (MDAP). Dodatkowo, w ostatnim dziesięcioleciu mamy do czynienia ze zmianą w postrzeganiu transpłciowości o niemal paradygmatycznym charakterze wyrażoną w kolejnych edycjach systemów diagnostycznych (DSM, ICD), z czym związane są równie fundamentalne zmiany w zasadach prowadzenia opieki zdrowotnej nad osobami transpłciowymi, które znalazły wyraz między innymi w Standardach Opieki opublikowanych przez WPATH w 2012 roku. Zrodziło to potrzebę sformułowania zaleceń dla specjalistów praktykujących w Polsce, aby przynajmniej częściowo uwzględnić wspomnianą ewolucję poglądów i zasad postępowania w odniesieniu do osób transpłciowych poszukujących pomocy w związku z doświadczaną dysforią płciową.
Exact Multiple Sequence Alignment by Synchronized Decision Diagrams
Authors: Hosseininasab Amin , van Hoeve Willem-Jan
Published: September 2020

This paper develops an exact solution algorithm for the multiple sequence alignment (MSA) problem. In the first step, we design a dynamic programming model and use it to construct a novel multivalued decision diagram (MDD) representation of all pairwise sequence alignments (PSA). PSA MDDs are then synchronized using side constraints to model the MSA problem as a mixed-integer program (MIP), for the first time, in polynomial space complexity. Two bound-based filtering procedures are developed to reduce the size of the MDDs, and the resulting MIP is solved using logic-based Benders decomposition. For a more effective algorithm, we develop a two-phase solution approach. In the first phase, we use optimistic filtering to quickly obtain a near-optimal bound, which we then use for exact filtering in the second phase to prove or obtain an optimal solution. Numerical results on benchmark instances show that our algorithm solves several instances to optimality for the first time, and, in case optimality cannot be proven, considerably improves upon a state-of-the-art heuristic MSA solver. Comparison with an existing state-of-the-art exact MSA algorithm shows that our approach is more time efficient and yields significantly smaller optimality gaps.
PENGELOLAAN KAIN TENUN SONGKET KHAS PALEMBANG DI DESA PEDU KABUPATEN JEJAWI KECAMATAN OGAN KOMERING ILIR (OKI)
Authors: Hidayat Hidayat , Gunadi Gunadi , Arlangga Lazi , Yulianti Firda
Published: September 2020

Abstract: Management in general can be said that the stages in carrying out or carrying out management include: planning, organizing, implementing, and controlling. The method of implementation is a general strategy adopted in the collection and analysis of data needed to answer the problem being investigated or investigated. The approach used is a qualitative approach with a descriptive method, which provides a great opportunity for researchers to describe field findings in Pedu Village. Type of qualitative research. Data collection techniques, as follows: observation, documentation, interviews. The results of this community service activity are Pedu village people who manage varied songket cloths, this activity is an effort of craftsmen to increase the attractiveness of buyers by selling songket cloth at low prices but not at a loss and changing yarn variations and motifs used in making songket. Palembang Typical Songket Woven Fabric in Pedu Village, Jejawi District, Ogan Komering Ili Regency (OKI) 2020, is expected to be one of the efforts to empower songket cloth better in the future so that it can develop rapidly.
Germination and Early Seedling Growth of Two Rice Varieties as Affected by Invasive Ageratina adenophora
Authors: Khatri Kavita , Bargali Kiran , Negi Bhawana , Bargali S.S.
Published: September 2020

Ageratina adenophora is a perennial herb of family Asteraceae expanding as a serious threat to ecological integrity and biodiversity. This study aims to assess the allelopathic potential of fresh and dry leaf and root aqueous extracts of this invasive species on germination, early seedling growth, seedling biomass and seed vigor of two rice (Oryza sativa L.) varieties namely 6444 and 2245. The result revealed that with increasing concentration of extract, inhibition effect also increases. Leaf extract was more inhibitory than root extract and dry plant extracts had higher allelopathic impact in comparison to fresh plant extracts. Among the two investigated rice varieties 6444 was more resistant to the fresh and dry leaf extract while 2245 was more resistant to fresh and dry root extract. This study will be helpful in assessing the effect caused by A. adenophora to rice crop and could be used in devising weed control strategy.
Understanding evidence use from a programmatic perspective: conceptual development and empirical insights from national malaria control programmes
Authors: Parkhurst Justin , Ghilardi Ludovica , Webster Jayne , Hoyt Jenna , Hill Jenny , Lynch Caroline A.
Published: September 2020

Background:

Conceptualisations of what it means to use evidence in policymaking often appear divided between two extremes. On the one side are works presenting it as the implementation of research findings – particularly evaluations of intervention effect. In contrast stand theoretically informed works exploring the multiple meanings of evidence use, political complexities, and the constructed nature of research evidence itself. The first perspective has been criticised as over-simplistic, while the latter can make it difficult to answer questions of what might be good, or improved, uses of evidence in policymaking.

Methods:

To further debate, this paper develops a ‘programmatic approach’ to evidence use, drawing on theories of institutional decision making and empirical work on evidence use within 11 National Malaria Control Programmes in Africa. We apply the programmatic approach by investigating the key goals and tasks of programme officials, recognising that these will shape the routines and logics followed affecting evidence utilisation. We then map out the forms, sources, features, and applications of evidence that serve programme officials in their goals.

Findings:

In the case of malaria programmes, evidence use was understood in relation to tasks including: advocacy for funding, budget allocation, regulation development, national planning, and identification of information gaps – all of which might require different evidence sources, forms, and applications.

Discussion and conclusions:

Ultimately the programmatic approach aims to facilitate clearer understanding of what uses of evidence are appropriate to policymakers, while also allowing critical reflection on whether such uses are ‘good’ from both programme and broader social perspectives.
Effect of vascular structure on laser speckle contrast imaging
Authors: Jafari Chakameh Z. , Sullender Colin T. , Miller David R. , Mihelic Samuel A. , Dunn Andrew K.
Published: September 2020

Laser speckle contrast imaging (LSCI) is a powerful tool for non-invasive, real-time imaging of blood flow in tissue. However, the effect of tissue geometry on the form of the electric field autocorrelation function and speckle contrast values is yet to be investigated. In this paper, we present an ultrafast forward model for simulating a speckle contrast image with the ability to rapidly update the image for a desired illumination pattern and flow perturbation. We demonstrate the first simulated speckle contrast image and compare it against experimental results. We simulate three mouse-specific cerebral cortex decorrelation time images and implement three different schemes for analyzing the effects of homogenization of vascular structure on correlation decay times. Our results indicate that dissolving structure and assuming homogeneous geometry creates up to ∼ 10x shift in the correlation function decay times and alters its form compared with the case for which the exact geometry is simulated. These effects are more pronounced for point illumination and detection imaging schemes, highlighting the significance of accurate modeling of the three-dimensional vascular geometry for accurate blood flow estimates.
Mechanism study of terahertz radiation regulation in a multi-color laser field
Authors: Wang Shengfeng , Xiao Haicheng , Peng Yan
Published: September 2020

By establishing a theoretical model for terahertz (THz) generation from a laser-induced air plasma filament and the subsequent propagation process, we study the physical mechanisms of THz wave radiation regulation in the multi-color femtosecond laser field. It is proved that the total THz radiation in the far field is affected by three factors: the ionized electron density, transient current distribution along the laser filament, and coherent superposition between THz waves generated by each point along the filament. The results show that the wavelength, relative phase, energy ratio, pulse width, laser frequency ratio, and frequency combination of the multi-color laser are all correlated to their radiated THz energy with different changing laws. The proper regulation of a three-color filament can realize a 4 orders of magnitude increase in the generated THz pulse energy as compared with the conventional THz generation by a two-color filament. These results provide the theoretical basis for the enhancement of THz radiation energy, and they are of great significance for clarifying the physical process of laser filament.
Non-stationary testing of avalanche-like behavior of up-conversion luminescence
Authors: Korolkov M. V.
Published: September 2020

Nonlinear coupling of pumping rates in pump channels can produce effects very similar to the photon avalanche in up-conversion luminescence in the absence of a true avalanche. Stationary luminescence intensity can depend on the pump intensity practically in the same way. Here we show that time-dynamics for true avalanche and for avalanche-like processes are drastically different. Based on measuring the development times of stationary luminescence for several pump intensities, a simple test is proposed to reveal the nonlinear process underlying the observed avalanche-like effect.
Spoof surface plasmon analysis based on Marcatili’s method
Authors: Khosrovani-Moghaddam Mohammad Ali , Shishegar Amir Ahmad
Published: September 2020

Motivated by surface plasmon polariton waveguides in the optical regime, spoof surface plasmon (SSP) waveguides have received a lot of attention in terahertz and millimeter wave frequencies. Most research on these kinds of waveguides is numerical. However, some limited analytical work can be seen in the literature. In this paper, one type of SSP waveguide that is composed of a rectangular corrugation with finite lateral width on the ground is considered, and an analytical method, which is inspired by Marcatili’s method, is proposed in order to calculate the dispersion curve of the first mode. The results of this analytical method and a numerical commercial eigenmode solver are compared. The accuracy of this method by varying different geometrical parameters is shown. Finally, it is shown that this method works well in predicting the electromagnetic fields of the first mode.
Nonlinear dynamics of a laser diode with an injection of an optical frequency comb
Authors: Doumbia Yaya , Malica Tushar , Wolfersberger Delphine , Panajotov Krassimir , Sciamanna Marc
Published: September 2020

We experimentally and theoretically demonstrate the variety of the nonlinear dynamics exhibited by a single frequency semiconductor laser subjected to optical injection from a frequency comb. The injection parameters (the detuning and the injection strength) and the comb properties (comb spacing and the amplitude of the injected comb lines) are varied to unveil several dynamics such as injection locking, wave-mixing, chaotic dynamics, and unlocked time-periodic dynamics corresponding to new comb solutions. The asymmetry of the injected comb is shown to modify the size of the injection locking region in the parameter space, as well as the common properties between the new comb solutions observed and the injected comb.
Loss measurement of each mode in few-mode fiber links with crosstalk-inducing points based on optical time domain reflectometry
Authors: Nakamura Atsushi , Oda Tomokazu , Iida Daisuke
Published: September 2020

We propose a novel technique based on optical time domain reflectometry for characterizing the losses of transmission modes along few-mode fiber links. The technique estimates the transfer matrix at a crosstalk-inducing point from the measured backscattered waveforms and then eliminates the crosstalk influence of the point on the waveforms. Waveforms that are free from the crosstalk influence enable us to obtain the true losses independently of the crosstalk-inducing point. A proof-of-concept demonstration is performed on an optical fiber with a crosstalk-inducing splice and a bend, and the results show the usefulness of the proposed technique.
Dual-wavelength Mach-Zehnder interferometry-assisted photothermal spectroscopy for characterization of surface contaminants
Authors: Dong Jingtao , Yan Peizheng , Yang Lei , Zhang Yuzhong , Zhang Tengda , Zhang Lei , Zhou Sheng , Li Jingsong
Published: September 2020

Photothermal spectroscopy (PTS) working in the mid-infrared region is an effective technique for in-situ characterization of the chemical composition of surface contaminants. The sensitivity relies on the way that the laser-induced response of the sample is detected. We present a highly-sensitive PTS assisted with a dual-wavelength Mach-Zehnder interferometer (MZI), MZI-PST in short. The MZI aims to sense all the phase delays taking place at the sample and air when the heat produced by resonance absorption of the contaminant is transferred into its surroundings and further to amplify the total phase delay to a large intensity difference of a probe beam. To guarantee a stable quadrature phase bias of the MZI working in the balanced detection mode, we employ two separate wavelengths, one for sensing and the other for phase bias feedback, to lock the working point to the quadrature point in real time. The MZI is expected to have a 7.8-fold sensitivity enhancement compared with the conventional phase-sensitive PTS in theory. The results of the proof-of-concept experiment on the olive oil contaminated on a wafer surface verify the spectral fidelity and the sensitivity enhancement as well as the capability of photothermal spectral imaging of the MZI-PST.
Admissible surfaces in progressive addition lenses
Authors: Barbero Sergio , González María del Mar
Published: September 2020

Progressive addition lenses (PALs) contain a surface of spatially varying curvature, which supplies variable optical power for different viewing areas over the lens. We derive complete compatibility equations providing the exact magnitude of a cylinder along lines of curvature on any arbitrary PAL smooth surface. These equations reveal that, contrary to current knowledge, the cylinder and its derivative depend not only on the principal curvature and its derivatives along the principal line but also on the geodesic curvature and its derivatives along the line orthogonal to the principal line. We quantify the relevance of the geodesic curvature through numerical computations. We also derive an extended and exact Minkwitz theorem restricted only to be applied along lines of curvature, but excluding umbilical points.
Gas sensing with mode-phase-difference photothermal spectroscopy assisted by a long period grating in a dual-mode negative-curvature hollow-core optical fiber
Authors: Zhao Pengcheng , Ho Hoi Lut , Jin Wei , Fan Shangchun , Gao Shoufei , Wang Yingying , Wang Pu
Published: September 2020

We demonstrate sensitive gas detection with mode-phase-difference photothermal spectroscopy assisted by a long period grating (LPG) inscribed on a dual-mode negative-curvature hollow-core fiber (NC-HCF). The LPG is inscribed using a pulsed

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P

01

mode to achieve maximum photothermal phase modulation while exciting both the

L
P

01

and

L
P

11

modes at the probe wavelength to form a dual-mode interferometer for detection of the phase difference. With a 1533 nm pump and a 1620 nm probe, a noise equivalent concentration of

∼

2.2

ppb acetylene is achieved with an 85-cm-long NC-HCF gas cell and 1 s lock-in time constant.
Higher-order dispersion and the spectral behavior in a doubly resonant optical parametric oscillator
Authors: Dietrich Christian M. , Babushkin Ihar , Cardoso de Andrade José R. , Rao Han , Demircan Ayhan , Morgner Uwe
Published: September 2020

In doubly resonant optical parametric oscillators (DROPOs), it is possible to generate, enhance, and phase lock two frequencies at once. Following intracavity phase conditions, a complex tuning behavior of the signal and idler spectra takes place in DROPOs, cumulating into degeneracy with phase self-locking and coherent wavelength doubling. In this work, we identify group delay matching as the important parameter determining the global tuning behavior and demonstrate the key role of higher-order dispersion in the spectral dependencies. Applicationwise, we suggest a simple way to control the phase self-locking region by varying the intracavity third-order dispersion.
Efficient solid-state Raman yellow laser at 579.5  nm
Authors: Chen Y. F. , Chen C. M. , Lee C. C. , Huang H. Y. , Li D. , Hsiao J. Q. , Tsou C. H. , Liang H. C.
Published: September 2020

A highly efficient diode-pumped

N
d

:

Y
V
O

4

/

K
G
W

Raman yellow laser is developed to produce a 6.8 W yellow light at 579.5 nm accompanied by a 3.2 W Stokes wave at 1159 nm under an incident pump power of 30 W. The intracavity stimulated Raman scattering with the shift of

768

c

m

−
1

is generated by setting the polarization of the fundamental wave along the

N
g

direction of an

N
p

-cut KGW crystal. The

N
d

:

Y
V
O

4

gain medium is coated as a cavity mirror to reduce the cavity losses for the fundamental wave. More importantly, the KGW crystal is specially coated to prevent the Stokes wave from propagating through the gain medium to minimize the cavity losses for the Stokes wave.
High-power diode-pumped Nd:GdVO4/KGW Raman laser at 578  nm
Authors: Chen Y. F. , Huang H. Y. , Lee C. C. , Hsiao J. Q. , Tsou C. H. , Liang H. C.
Published: September 2020

A diode-pumped neodymium-doped gadolinium vanadate (

N
d

:

G
d
V

O

4

) laser is developed as a compact efficient yellow light at 578 nm by means of intracavity stimulated Raman scattering (SRS) in a potassium gadolinium tungstate (KGW) crystal and the second-harmonic generation in a lithium triborate crystal. The SRS process with a shift of

768

c

m

−
1

is achieved by setting the polarization of the fundamental wave along the

N
g

axis of the KGW crystal. The self-Raman effect arising from the

N
d

:

G
d
V

O

4

crystal is systematically explored by employing two kinds of coating specification for the output coupler. With a specific coating on the output coupler to suppress the self-Raman effect, the maximum output power at 578 nm can reach 3.1 W at a pump power of 32 W. Moreover, two different lengths for the

N
d

:

G
d
V

O

4

crystal are individually used to verify the influence of the self-Raman effect on the lasing efficiency.
Trapped excited electrons in Ni2+-doped perovskite KZnF3 nanocrystals in KF–ZnF2–SiO2 glass ceramics: publisher’s note
Authors: Ding Dashuang , Wang Yanlong , Lin Changgui , Zhang Shaoqian , Duo Liping
Published: September 2020

This publisher’s note contains a correction to Opt. Lett. 45, 4984 (2020)OPLEDP0146-959210.1364/OL.402229.
Nanomechanical test of quantum linearity
Authors: Forstner Stefan , Zych Magdalena , Basiri-Esfahani Sahar , Khosla Kiran E. , Bowen Warwick P.
Published: September 2020

Spontaneous wavefunction collapse theories provide the possibility to resolve the measurement problem of quantum mechanics. However, the best experimental tests have been limited by thermal fluctuations and have operated at frequencies far below those conjectured to allow the proposed cosmological origin of collapse to be identified. Here we propose to use high-frequency nanomechanical resonators to surpass these limitations. We consider a specific implementation that uses a breathing mode of a quantum optomechanical system cooled to near its motional ground state. The scheme combines phonon counting with efficient mitigation of technical noise, including nonlinear photon conversion and photon coincidence counting. It can resolve the exquisitely small phonon fluxes required for a conclusive test of collapse models as well as testing the hypothesis of a cosmological origin of the collapse noise.
Ultra-high-resolution software-defined photonic terahertz spectroscopy
Authors: Hermans Rodolfo I. , Seddon James , Shams Haymen , Ponnampalam Lalitha , Seeds Alwyn J. , Aeppli Gabriel
Published: September 2020

A novel technique for high-resolution

1.5

µ

m

photonics-enabled terahertz (THz) spectroscopy using software control of the illumination spectral line shape (SLS) is presented. The technique enhances the performance of a continuous-wave THz spectrometer to reveal previously inaccessible details of closely spaced spectral peaks. We demonstrate the technique by performing spectroscopy on

L
i
Y
F

4

:

H
o

3
+

, a material of interest for quantum science and technology, where we discriminate between inhomogeneous Gaussian and homogeneous Lorentzian contributions to absorption lines near 0.2 THz. Ultra-high-resolution (

<

100

H
z

full-width at half maximum) frequency-domain spectroscopy with quality factor

Q
>
2
×

10
9

is achieved using an exact frequency spacing comb source in the optical communications band, with a custom uni-traveling-carrier photodiode mixer and coherent down-conversion detection. Software-defined time-domain modulation of one of the comb lines is demonstrated and used to resolve the sample SLS and to obtain a magnetic field-free readout of the electronuclear spectrum for the

H
o

3
+

ions in

L
i
Y
F

4

:

H
o

3
+

. In particular, homogeneous and inhomogeneous contributions to the spectrum are readily separated. The experiment reveals previously unmeasured information regarding the hyperfine structure of the first excited state in the

5

I
8

manifold complementing the results reported in Phys. Rev. B 94, 205132 (2016)PRBMDO0163-182910.1103/PhysRevB.94.205132.
On BER analysis of nonlinear VLC systems under ambient light and imperfect/outdated CSI
Authors: Jain Sandesh , Mitra Rangeet , Bhatia Vimal
Published: September 2020

Visible light communication (VLC) has emerged as a promising supplement to the existing radio frequency (RF) technology, which facilitates high speed communication for next generation communication systems. Although promising, the performance in a practical VLC system is severely impaired by ambient light interference. Furthermore, nonlinearity of light emitting diodes (LEDs) and imperfect/oudated channel state information (CSI) are other factors that degrade the achievable bit error rate (BER) performance. In this work, an analytical framework for analyzing the expression for BER of a wide class of modulation techniques is derived for an impaired VLC system considering: (a) ambient light interference, (b) LED nonlinearity, and (c) imperfect and outdated CSI. The derived analytical expressions for BER are validated through extensive computer simulations performed over typical VLC channels. Lastly, the utility of the derived analytical framework is demonstrated in the context of high data-rate VLC systems, wherein the performance of DC biased optical orthogonal frequency division multiplexing (DCO-OFDM) is quantified for VLC links impaired by the aforementioned degradations.
Life story and the arts: A didactic crossroad
Authors: Schwartz Samuel , Lieblich Amia , Speiser Vivien Marcow , Lakh Elana , Cohen Tsiky , Dushi Pazit , Gilad Anat , Vaisvaser Sharon
Published: September 2020

The following notes from the field introduces an original approach to working with narrative, storytelling and artistic expression in the framework of the creative and expressive arts therapies. Using an interview methodology developed by Amia Lieblich, a team of creative and expressive arts therapists teaching at The Academic College of Society and the Arts in Netanya, Israel, shares their theoretical observations and practical perspectives about moving from verbal to non-verbal expression of personal and collective stories. These insights emerged during an introductory course that the authors taught to creative and expressive arts therapists. We posit that life story work, both in regard to oneself and to others, from single episode memory or the documentation of the entire life course, may be of tremendous worth in the training of creative and expressive art therapists.
HEMORRHAGIC NEUROLOGICAL MANIFESTATIONS IN A PATIENT WITH COVID - 19: CASE REPORT
Authors: Oliveira Ramille Gonçalves , Clementino Constantino Felipe Leandro , Dias Priscila Teixeira , Albuquerque Lucas Tavares Cruz de , Passos Filho Marcus Vinicius Maia , Cavalcante Raphael Justo , Pinheiro Raphael Xenofonte Morais
Published: September 2020

Abstract: SARS-CoV-2 infection has had a major impact on global health, affecting from the respiratory system to the central nervous system, generating a wide spectrum of clinical manifestations.  Stroke has been reported in the recent literature when addressing the neurological repercussions in patients affected by COVID-19, with unfavorable outcomes when compared to those not infected by SARS-CoV-2.  There are multiple theories that try to elucidate neural clinical manifestations, from hematogenous infection to direct entry through the cribiform blade.  This article shows a case report of a patient with COVID-19 and neurological involvement with diagnostic hypotheses of acute necrotizing encephalopathy, a rare post-viral infection condition in adults and ischemic stroke with subsequent hemorrhagic transformation, correlating the aspects observed in the image and  in the patient's clinic with the current literature and theories. Keywords: Coronavirus infections, Acute necrotizing encephalopathy, Hemorrhagic transformation, Ischemic stroke.
Bioremoval of Zinc Using the Tomato Plant, Lycopersicon esculentum
Authors: Devi S Yamuna Devi S , A Surendran , A.J Thatheyus
Published: September 2020

Effluents discharged from various industries contain heavy metals. They reach the environment and affect the quality of air, water and soil. Though they are needed in trace quantities for living organisms, they become toxic when they exceed the threshold concentrations. Hence the present study has been designed to test the efficiency of Lycopersicon esculentum in removing zinc from soil. The tomato plants were grown in soil applied with 100, 200, 300, 400 and 500ppm of zinc sulphate for 60 days. Every fortnight, soil samples were taken and analysed for the levels of Cu, Zn, Fe and Mn. Percent removal of zinc by the plant was calculated from the residual concentration. More removal was noticed in higher concentrations of zinc. After 60 days of treatment, levels of Cu, Zn, Fe and Mn were analysed in the above ground and below ground parts of the tomato plant. Zinc level was 90 ppm in both cases and the same in plants grown in all the concentrations of zinc sulphate. Fluctuations in chlorophyll content were noticed while decline was observed in microbial colonies. The data were subjected to two way analysis of variance and the results are discussed.