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Can phenology and plasticity prevent adaptive clines in tolerance limits across tempe...
Luis Gutiérrez-Pesquera
Miguel Tejedo

Luis Gutiérrez-Pesquera

and 7 more

August 06, 2021
Critical thermal limits (CTmax and CTmin) are predicted to decrease with elevation, with greater change in CTmin, and the risk to suffer heat and cold stress increasing at the gradient ends. A central prediction is that populations will adapt to the prevailing climatic conditions. Yet, reliable support for such expectation is scant because of the complexity of integrating phenotypic and molecular divergence. We propose that phenotypic plasticity and breeding phenology may hinder local adaptation cancelling the appearance of adaptive patterns. We examined intraspecific variation of CTmax/CTmin in 11 populations of an amphibian across an elevational gradient, and assessed (1) the existence of local adaptation through a PST-FST comparison, (2) the acclimation scope in both thermal limits, and (3) the vulnerability to suffer acute heat (CTmax–tmax) and cold (tmin–CTmin) thermal stress, measured at both macro- and microclimatic scales. Our study revealed significant microgeographic variation in CTmax/CTmin, and unexpected elevation gradients in pond temperatures. However, variation in CTmax/CTmin could not be attributed to selection because critical thermal limits were not correlated to elevation or temperatures. Differences in breeding phenology among populations resulted in exposure to higher and more variable temperatures at mid and high elevations. Accordingly, mid- and high-elevation populations had higher CTmax and CTmin plasticities than lowland populations, but not more extreme CTmax/CTmin. Thus, we confirm our prediction that plasticity and phenological shifts may hinder local adaptation, promoting thermal niche conservatism and a higher vulnerability to climate change. This contradicts some of the existing predictions on adaptive thermal clines.
Behcet’s Disease in an Adult Male From Nepal: A Case Report
Madan Basnet
Abisha Phudong

Madan Basnet

and 6 more

August 06, 2021
Behcet's Disease is a rare systemic vasculitis characterized by recurrent episodes of acute inflammation affecting blood vessels of all sizes. Symptoms include orogenital apthosis, cutaneous skin lesions, and uveitis. We present the case of a 38-year-old Nepalese man with Behcet's Disease. In Nepal, Behcet's Disease may still be under-reported.
Perimedullary Spinal Arteriovenous Malformation in an Elderly Female: A Case Report
Madan Basnet
Suman Gaire

Madan Basnet

and 6 more

August 06, 2021
Perimedullary spinal AVM is a rare type of spinal arteriovenous malformations. We present a case of 70 yrs female who presented with motor weakness in her bilateral limbs. Initial MRI was misinterpreted as ependymal myxoma; however, histopathology revealed spinal AVM. MRA or DSA should be conducted if AVM is suspected.
Presenting symptoms and diagnosis of vulvar lichen sclerosus in premenopausal women:...
Jill  Krapf
Alyssa Smith

Jill Krapf

and 3 more

August 06, 2021
Objective: Characterize the presentation of vulvar lichen scleorsus (LS) among premenopausal women. Design: Cross-sectional study. Setting: An international web-based survey distributed on social media support groups and in two urban gynecology offices specializing in LS. Population: A total of 503 premenopausal women with biopsy-confirmed vulvar LS between the ages of 18-50. Methods: Participants completed an anonymous 28-question web-based survey between January to March 2021. Main Outcome Measures: Symptoms, timing and accuracy of diagnosis, and presence of concomitant autoimmune conditions. Results: Symptoms reported to be most present and affect the individual were dyspareunia (68%; 44%) and tearing with intercourse or vaginal insertion (63%; 39%). Symptoms that most frequently prompted patients to seek medical attention were dyspareunia (35%), pruritus (31%), and tearing with intercourse or vaginal insertion (26%). Most common skin changes included hypopigmentation (81%), vulvar fissures (72%) and labial resorption (60%), with fissures affecting the individual the most (48%). There was a 4-year delay in diagnosis with an average age of symptom onset of 27 years and average age of diagnosis of 32 years. Sixty-six percent of respondents initially received an alternative diagnosis, most commonly vulvovaginal yeast infection (49%). There is an increased incidence of hypothyroidism, vitiligo, pernicious anemia, and celiac disease. Conclusion: Premenopausal women with vulvar LS more commonly present with dyspareunia and tearing with intercourse, less often than vulvar pruritis. This condition should be considered and evaluated in women of all ages presenting with vulvar symptoms and sexual pain. Funding: None Keywords: lichen sclerosus; vulvar dermatoses; vulvar pruritis; dyspareunia
Uncertainty Quantification in Machine Learning and Nonlinear Least Squares Regression...
Ni Zhan
John R. Kitchin

Ni Zhan

and 1 more

August 05, 2021
Machine learning (ML) models are valuable research tools for making accurate predictions. However, ML models often unreliably extrapolate outside their training data. We propose an uncertainty quantification method for ML models (and generally for other nonlinear models) with parameters trained by least squares regression. The uncertainty measure is based on the multiparameter delta method from statistics, which gives the standard error of the prediction. The uncertainty measure requires the gradient of the model prediction and the Hessian of the loss function, both with respect to model parameters. Both the gradient and Hessian can be readily obtained from most ML software frameworks by automatic differentiation. We show that the uncertainty measure is larger for input space regions that are not part of the training data. Therefore this method can be used to identify extrapolation and to aid in selecting training data or assessing model reliability.
Continuous synthesis of TiO2-supported noble metal NPs and their application in ammon...
Lamei Luo
Mei Yang

Lamei Luo

and 2 more

August 05, 2021
A stabilizer-free method based on segmented flow for the continuous synthesis of TiO2 supported noble metal nanoparticles (M/TiO2-MR, M = Pd, Pt or Au) was proposed. Due to the enhanced mixing performance arising from the internal convection in the discrete plugs, the particle size of noble metal nanoparticles could be well controlled by reducing the metal precursors with NaBH4 just in the presence of TiO2 without using any stabilizer. In comparison with the batch method, the as-prepared M/TiO2-MR had smaller noble metal particle size and better dispersity. Experimental results showed that adjusting the oil-to-water phase ratio or increasing the total volume flow rate and synthetic temperature could lead to smaller average particle size with narrower distribution. The as-prepared M/TiO2-MR possessed higher catalytic activities in the hydrolysis of ammonia borane than those prepared by the batch method, which could be ascribed to smaller noble metal nanoparticles, exposing more active sites.
Progression of Aortic Stenosis in Patients with Bicuspid Aortic Valve
Michael Shang
Arianna Kahler-Quesada

Michael Shang

and 5 more

August 05, 2021
Background: Bicuspid aortic valve is the most common congenital heart defect and predisposes patients to developing aortic stenosis more frequently and at a younger age than the general population. However, the influence of bicuspid aortic valve on the rate of progression of aortic stenosis remains unclear. Methods: In 236 patients (177 tricuspid aortic valve, 59 bicuspid aortic valve) matched by initial severity of mild or moderate aortic stenosis, we retrospectively analyzed baseline echocardiogram at diagnosis with latest available follow-up echocardiogram. Baseline comorbidities, annualized progression rate of hemodynamic parameters, and hazard of aortic valve replacement were compared between valve phenotypes. Results: Median echocardiographic follow-up was 2.6 (IQR 1.6-4.2) years. Patients with tricuspid aortic stenosis were significantly older with more frequent comorbid hypertension and congestive heart failure. Median annualized progression rate of mean gradient was 2.3 (IQR 0.6-5.0) mmHg/year vs. 1.5 (IQR 0.5-4.1) mmHg/year (p=0.5), and that of peak velocity was 0.14 (IQR 0-0.31) m/s/year vs. 0.10 (IQR 0.04-0.26) m/s/year (p=0.7) for tricuspid vs. bicuspid aortic valve, respectively. On multivariate analyses, bicuspid aortic valve was not significantly associated with more rapid progression of aortic stenosis. In a stepwise Cox proportional hazards model adjusted for baseline mean gradient, bicuspid aortic valve was associated with increased hazard of aortic valve replacement (HR: 1.7, 95% CI [1.0, 3.0], p=0.049). Conclusion: Bicuspid aortic valve may not significantly predispose patients to more rapid progression of mild or moderate aortic stenosis. Guidelines for echocardiographic surveillance of aortic stenosis need not be influenced by valve phenotype.
Pharmacogenomic alerts: developing guidance for use by healthcare professionals
John-Paul Carter
James Critchlow

John-Paul Carter

and 7 more

August 05, 2021
Background: For diseases with a genetic cause genomics can deliver improved diagnostics and facilitate access to targeted treatments. Drug pharmacodynamics and pharmacokinetics are often dependent on genetic variation underlying these processes. As pharmacogenomics comes of age it may be the first way in which genomics is utilised at a population level. Still required is guidance and standards of how genomic information can be communicated within the health record, and how clinicians should be alerted to variation impacting the use of medicines. Methods: The Professional Record Standards Body commissioned by National Health Service England developed guidance on using pharmacogenomics information in clinical practice. We conducted research with those implementing pharmacogenomics in England and internationally to produce guidance and recommendations for a systems-based approach. Results: A consensus viewpoint is that systems need to be in place to ensure the safe provision of pharmacogenomics information that is curated, actionable and up-to-date. Standards should be established with respect to notification and information exchange, which could impact new or existing prescribing and these must be in keeping with routine practice. Alerting systems should contribute to safer practices. Conclusion: Ensuring pharmacogenetics information is available to make use of medicines safer will require major effort of which this guidance is a beginning. Standards are required to ensure useful genomic information within the health record can be communicated to clinicians in the right format and times to be actioned successfully. A multidisciplinary group of stakeholders must be engaged in developing pharmacogenomic standards to support the most appropriate prescribing.
An efficient noninvasive method for simultaneous species, individual, and sex identif...
Lillian D. Parker, Ph.D.

Lillian D. Parker

and 10 more

August 05, 2021
A document by Lillian D. Parker, Ph.D.. Click on the document to view its contents.
An efficient noninvasive method for simultaneous species, individual, and sex identif...

Lillian D Parker

and 10 more

August 05, 2021
A document by Lillian D. Parker, Ph.D.. Click on the document to view its contents.
Primary bladder amyloidosis mimicking bladder cancer complicated by bladder rupture:...
Rayan Sibira
Ahmed Albakr

Rayan Sibira

and 4 more

August 05, 2021
Primary bladder amyloidosis is a rare pathological finding. The clinical importance of this finding is that it may clinically mimic bladder cancer. The only accurate diagnostic method available till now is the histopathologic examination of tissue samples usually obtained through transurethral resection.
Estimating the burden of adult hospital admissions due to RSV and other respiratory p...
Ashley Sharp
Mehdi Minaji

Ashley Sharp

and 5 more

August 05, 2021
Respiratory Syncytial Virus (RSV) is a common seasonal respiratory virus and an important cause of illness among infants, but the burden of RSV disease is not well described among the older population. The objective of this study was to estimate the age-specific incidence of hospital admission among over 65s due to respiratory illnesses attributable to RSV in England to inform optimal vaccine and therapeutic interventions. We used linear multiple regression to examine the effect of changes in weekly counts of respiratory pathogens on the weekly counts of respiratory hospital admissions. The study population was all patients aged 65 years or over admitted to English hospitals between 2nd August 2010 and 30th July 2017. RSV was estimated to account for a seasonal annual average of 71 (95% CI 52-90) respiratory admissions per 100,000 in adults age 65-74 and 251 (95% CI 186-316) admissions per 100,000 adults age 75+. Pneumococcus was the pathogen responsible for highest annual average respiratory admission with 448 (95% CI 310-587) admissions per 100,000 adults age 65-74 and 1010 (95%CI 527-1493) admissions per 100,000 adults aged 75+. This study shows that RSV continues to exert a significant burden of disease among older adults in England. These findings will support development of policy for the use of RSV therapeutics and vaccines in this age group.
A latitudinal signal in the relationship between species geographic range size and cl...
Tad Dallas
Andrew Kramer

Tad Dallas

and 1 more

August 05, 2021
Species with broader niches may have the opportunity to occupy larger geographic areas, assuming no limitations on dispersal and a relatively homogeneous environmental space. While there is general support for positive \textit{geographic range size – climatic niche area} relationships, a great deal of variation exists across taxonomic and spatial gradients. Here, we use data on a large set of mammal ($n$ = 1225), bird ($n$ = 1829), and tree ($n$ = 341) species distributed across the Americas to examine the \textbf{1}) relationship between geographic range size and climatic niche area, \textbf{2}) influence of species traits on species departures from the best fit geographic range size – climatic niche area relationship, and \textbf{3}) how detection of these relationships is sensitive to how species range size and climatic niche area are estimated. We find positive \textit{geographic range size – climatic niche area} relationships for all taxa. Residual variation in this relationship contained a strong latitudinal signal. Subsampling the occurrence data to create a null expectation, we found that residual variation did not strongly deviate from the null expectation. Together, we provide support for the generality of \textit{geographic range size – climatic niche area} relationships, which may be constrained by latitude but are agnostic to species identity, suggesting that species traits are far less responsible than geographic barriers and the distribution of land area and available environmental space.
Infective endocarditis late after patent foramen ovale percutaneous closure in an add...
Walter Vignaroli
Angelo De Luca

Walter Vignaroli

and 5 more

August 05, 2021
We report an uncommon case of late infective endocarditis, in a patient with a history of intravenous drug abuse and HIV positivity, 9 years after a percutaneous closure of a patent foramen ovale. Despite a target and prolonged intravenous antibiotic therapy, he was then referred for surgical device and vegetation removal. Given the high risk associated with drug addiction lifestyle, especially in HIV positive cases, it is mandatory to observe this group of patients with lifelong follow-up and support. Furthermore, it may be considered a multidisciplinary-team approach to find the best option for these patients, also evaluating a surgical correction.
Reproductive colonization of land by frogs: embryos and larvae excrete urea to avoid...
Javier Mendez Narvaez
Karen Warkentin

Javier Mendez Narvaez

and 1 more

August 05, 2021
Vertebrate colonization of land occurred multiple times, including over 50 origins of terrestrial eggs in frogs. Some environmental factors and phenotypic responses that facilitated these transitions are known, but responses to water constraints and risk of ammonia toxicity during early development are poorly understood. We tested if ammonia accumulation and dehydration risk induce a shift from ammonia to urea excretion during in early stages of four anurans, from three origins of terrestrial development. We quantified ammonia and urea concentrations during early development on land, under well-hydrated and dry conditions. Where we found urea excretion, we tested for a plastic increase under dry conditions and with ammonia accumulation in developmental environments. We assessed the potential adaptive role of urea excretion by comparing ammonia tolerance measured in 96h-LC50 tests with ammonia levels in developmental environments. Ammonia accumulated in foam nests and perivitelline fluid, increasing over development and reaching higher concentrations under dry conditions. All four species showed high ammonia tolerance, compared to fishes and aquatic-breeding frogs. Both nest-dwelling larvae of Leptodactylus fragilis and late embryos of Hyalinobatrachium fleischmanni excreted urea, showing a plastic increase under dry conditions. These two species can develop the longest on land and urea excretion appears adaptive, preventing their exposure to potentially lethal levels of ammonia. Neither late embryos of Agalychnis callidryas nor nest-dwelling larvae of Engystomops pustulosus risked toxic ammonia levels under dry conditions, and neither excreted urea. Our results suggests that an early onset of urea excretion, its increase under dry conditions, and elevated ammonia tolerance, can all help prevent ammonia toxicity during terrestrial development. High ammonia represents a general risk for development that can be exacerbated as climate change increases dehydration risk for terrestrial-breeding frogs. It may also be a cue that elicits adaptive physiological responses during early development.
The Evaluation of Flow Mediated Dilatation and Blood Parameters in Raynaud Phenomenon
Suheyla UZUN
Ilker KAYA

Suheyla UZUN

and 1 more

August 05, 2021
Introduction: Raynaud phenomenon (RP) is a multifactorial disorder. If any underlying disease cannot be detected responsible for RP then it considered as primary RP (pRP). We aimed to investigate the differences between laboratory markers and impaired endothelial function in pRP. Material and Methods: Forty-two pRP patients included as study and control groups were created from 30 healthy individuals. The endothelial function was evaluated with flow-mediated dilatation (FMD) of the brachial artery. The blood samples were obtained both groups and white blood cell [WBC], hemoglobin, platelet, mean platelet volume [MPV], creatinine, alanine aminotransferase [ALT], aspartate aminotransferase[AST], D-dimer, fibrinogen, albumin, fibrinogen to albumin ratio [FAR], Neutrophil to Lymphocyte ratio [NLR], D-dimer to albumin ratio [DDAR] and monocyte chemo-attractant protein-1 [MCP-1]. Obtained blood parameters and FMD values were compared between groups. Results: The groups were found as similar in regards to age, gender, smoking history (p<0.05). There was no difference between the two groups in regards to hemoglobin, platelet, MPV, creatinine, ALT, D-dimer, albumin, FAR, NLR, DDAR levels (p<0.05). AST levels were slightly higher in pRP group (p=0.027). Markedly increased WBC, fibrinogen, MPV and MCP-1 values were detected in pRP group (p=0.000). Additionally, higher abnormal FMD responses were detected in pRP group (p=0.000). There was a direct correlation between abnormal FMD response and serum MCP-1 values in patients with pRP (R: 0.308, R2: 0.095, p: 0.044). Conclusion: It seems to be that MCP-1 levels are higher in patients with pRP and increased values of MCP-1 levels seem to be related to impaired endothelial functions
Adaptive monitoring of coral health at Scott Reef where data exhibit nonlinear and di...
Pubudu Thilan Abeysiri Wickrama Liyanaarachchige
Rebecca Fisher

Pubudu Thilan Abeysiri Wickrama Liyanaarachchige

and 5 more

August 05, 2021
Time series data are often observed in ecological monitoring. Frequently such data exhibit nonlinear trends over time potentially due to complex relationships between observed and auxiliary variables, and there may also be sudden declines over time due to major disturbances. This poses substantial challenges for modelling such data and also for model-based adaptive monitoring. We propose novel methods for finding adaptive designs for monitoring when historical data show such nonlinear patterns and sudden declines over time. This work is motivated by a coral reef monitoring program that has been established at Scott Reef; a coral reef off the Western coast of Australia. Data collected for monitoring the health of Scott Reef are considered, and semiparametric and interrupted time series modelling approaches are adopted to describe how these data vary over time. New methods are then proposed that enable adaptive monitoring designs to be found based on such modelling approaches. These methods are then applied to find future monitoring designs at Scott Reef and form a set of recommendations for future monitoring. Through applying the proposed methods, it was found that future information gain is expected to be similar across a variety of different sites, suggesting that no particular location needed to be prioritised at Scott Reef for the next monitoring phase. In addition, it was found that omitting some sampling sites/reef locations was possible without substantial loss in expected information gain, depending upon the disturbances that were observed. The resulting adaptive designs are used to provide recommendations for future monitoring in this region, and for reefs where changes to the current monitoring practices are being sought. Furthermore, as the methods used and developed throughout this study are generic in nature, this research has the potential to improve ecological monitoring more broadly where complex data are being collected over time.
Web-Crawling of Social Media to Analyze Backyard Poultry Owners Responses to the 2018...
Joseph  Gendreau
Shayne Ramsubeik

Joseph Gendreau

and 2 more

August 04, 2021
As social media becomes an ever-increasing staple of everyday life and a growing percentage of people turn to community driven platforms as a primary source of information, the data created from these posts can provide a new source of information from which to better understand an event in near real-time. The 2018-2020 outbreak of virulent Newcastle Disease (vND) in Southern California is the third outbreak of vND in Southern California within a 50-year time span. These outbreaks are thought to be primarily driven by non-commercial poultry (i.e. backyard and game fowl) in the region. Here we employed a commercial “web crawling” tool between June of 2018 and July of 2020 which encompassed the majority of the outbreak in order to collect all available online mentions of virulent Newcastle Disease (vND) in relation to the outbreak. A total of 2,498 posts in English and Spanish were returned using a Boolean logic-based string search. While the number of posts was relatively small, their impact as measured by the number of visitors to the website and the number of people viewing the post (where provided) was much larger. Using views as a metric, Twitter was identified as the most significant source of comments over blogs, forums and other news sites. Posts with negative sentiment were found to have a larger audience relative to posts with a positive sentiment. In addition, posts with negative sentiment peaked in May of 2019 which preceded the formation of the anti-depopulation group Save Our Birds (SOB). As the usage and impact of social media grows, the ability to utilize tools to analyze social media may improve both response and outreach-based strategies for various disease outbreaks including vND in Southern California which has a large non-commercial poultry population.
Low value Injury Care in the Adult Orthopaedic Trauma Population: A Systematic Review
Mélanie Bérubé
Lynne Moore

Mélanie Bérubé

and 6 more

August 04, 2021
Objectives. Fifteen potentially low value practices in adult orthopaedic trauma care were previously identified in a scoping review. The aim of this study was to synthesize the evidence on these practices. Methods. We searched four databases for systematic reviews, randomized controlled trials (RCTs), cohort studies and case series that assessed the effectiveness of selected practices. Methodological quality was evaluated using the Measurement Tool to Assess Systematic Reviews version 2 (AMSTAR-2) for systematic reviews and the Critical Appraisal Checklist for Case Series. We evaluated risk of bias with the Cochrane revised tool for RCTs and the risk of bias in non-randomized studies of interventions tool for observational studies. We summarized findings with measures of frequency and association for primary outcomes. Results. Of the 30,670 records screened, 70 studies were retained. We identified high-level evidence of lack of effectiveness or harm for routine initial imaging of ankle injury, orthosis for A0-A3 thoracolumbar burst fracture in patients < 60 years of age, cast or splint immobilization for suspected scaphoid fracture negative on MRI or confirmed fifth metacarpal neck fracture, and routine follow-up imaging for distal radius and ankles fractures. However, evidence was mostly based on studies of low methodological quality or high risk of bias. Conclusion. In this review, we identified clinical practices in orthopedic injury care which are not supported by current evidence and whose use may be questioned. In future research we should measure their frequency, assess practice variations and evaluate root causes to identify practices that could be targeted for de-implementation.
Effectiveness of Closed-PICU Perioperative Management of Children with Congenital Tra...
Kazunori Aoki
Hiroshi Kurosawa

Kazunori Aoki

and 5 more

August 04, 2021
Perioperative management of congenital tracheal stenosis (CTS) is challenging. Objectives: We investigated the effect of closed-pediatric intensive care unit (PICU) perioperative management by pediatric intensivists, compared with open-PICU management by surgeons, on the ventilator-free days (VFD) and length of postoperative PICU stay in children with CTS. Methods: This retrospective cohort study was conducted in a PICU in Japan. Children with CTS who underwent slide tracheoplasty were grouped according to whether they were perioperatively managed in an open (January 2015 to April 2016) or a closed (May 2016 to July 2019) PICU. Data were extracted from patient medical records. Results: In total, 13 and 38 patients were included in the open- and closed-PICU groups, respectively. Compared to the open-PICU group, the closed-PICU group had shorter durations of muscle relaxant administration (median: 4 vs. 5 days; P < 0.001); earlier initiation of enteral feeding (median: postoperative day 1 vs. postoperative day 7; P < 0.001); more 28-day VFD (median: 21 vs. 20 days; P = 0.04); and shorter duration of postoperative PICU stay (median: 16 vs. 36 days; P = 0.002), but the mortality did not differ significantly (0/38 [0%] vs. 1/13 [8%]; P = 0.25). Conclusions: Closed-PICU perioperative management with pediatric intensivists’ participation significantly increased 28-day VFD and reduced the length of postoperative PICU stay in patients with CTS.
Postoperative recurrence of myxoid liposarcoma of left thigh with pericardial metasta...
Wenpeng Huang
Jianbo Gao

Wenpeng Huang

and 2 more

August 04, 2021
We report a rare case of postoperative recurrence of MLS in the left thigh with ectopic and metachronous pericardial metastases. He was found to have a cardiac abnormality that was initially thought to be a pericardial cyst, but was later pathologically confirmed to be MLS metastasis.
Prophylactic negative pressure wound dressing (NPWD) after caesarean – an extended de...
Shashikant Sholapurkar

Shashikant Sholapurkar

August 04, 2021
Letter to the Editor, BJOG Title:Prophylactic negative wound pressure dressing (NWPD) after caesarean – an extended debate to include surgical aspectsRe: Hyldig N, Joergensen JS, Lamont RF, Moller S, Vinter CA. Prophylactic negative pressure wound therapy in obese women undergoing caesarean section: a commentary on new evidence that fuels the debate. BJOG 2021; https://doi.org/10.1111/1471-0528.16750.Author: Mr. Shashikant L SHOLAPURKARMD, DNB, MRCOGDept of Obstetrics & Gynaecology,Royal United Hospital, Bath, BA1 3NG, UKEmail: s.sholapurkar@nhs.netTel: 07906620662Word count: 500Corresponding Author: Mr. Shashikant L SHOLAPURKARMD, DNB, MRCOGDept of Obstetrics & Gynaecology,Royal United Hospital, Bath, BA1 3NG, UKStatement of interest: The author has no conflict of interest or funding to declare.
Nanobody-Functionalized Cellulose for Capturing and Containing SARS-CoV-2
Xin Sun
Shaobo Yang

Xin Sun

and 6 more

August 04, 2021
The highly transmissible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected more than 196 million people, claiming ~ 4.2 million lives to date. Although mandatory quarantines, lockdowns, and vaccinations help curb viral transmission, safe and effective preventative measures remain urgently needed. Here, we present a generic strategy for containing SARS-CoV-2 by cellulose materials. Specifically, we developed a bifunctional fusion protein consisting of a cellulose-binding domain and a nanobody (Nb) targeting the receptor-binding domain of SARS-CoV-2. The immobilization of the fusion proteins on cellulose substrates enhanced the capture efficiency of Nbs against SARS-CoV-2 pseudoviruses of both the wildtype and the D614G variant, the latter of which has been shown to confer higher infectivity. Furthermore, the fusion protein was integrated into a customizable chromatography with highly porous cellulose for neutralizing virus from contaminated fluids in a continuous and cost-effective fashion. Taken together, our work leverages low-cost cellulose materials and recently developed Nbs to provide a complementary approach to addressing the pandemic.
Thermal decomposition and fire extinguishing mechanism of CF3I: a combined theoretica...
Rourou Yu
Wenhao Hu

Rourou Yu

and 4 more

August 04, 2021
The urgent desire for Halon substitution propels the exploration of potential alternatives, because of the severe damage of Halons to the stratospheric ozone layer. In this paper, the thermal decomposition mechanism, as well as fire-extinguishing mechanism and performance of Trifluoroiodomethane (CF3I) were studied by density functional theory (DFT) calculation and experimental measurements, to analyze the practicability of this proposed Halon substitute. The thermal decomposition products of CF3I can react with active OH· and H· radicals to achieve the purpose of rapidly fire-extinguishing. Besides, through DFT calculation and reaction kinetics analysis, the fire-extinguishing radicals CF3· and I· are more easily generated during the interaction between CF3I and flame, which indicates the chemical- extinguishing mechanism and pronounced fire-extinguishing performance of CF3I. To explore its actual fire-extinguishing effect, the fire-extinguishing concentration (FEC) of CF3I was measured in cup burner. The FEC value of this proposed Halon substitute is 3.42vol% for extinguishment of methane-air flame, which is smaller than those of three HFCs and HFO-1336mzz(Z) and is comparable to that of Halon 1301. These findings suggest the promising applicability of CF3I in practical Halon replacement and the necessity of further evaluation.
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