Sensitive visualization of SARS-CoV-2 RNA with CoronaFISH

The current COVID-19 pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The positive-sense single-stranded RNA virus contains a single linear RNA segment that serves as a template for transcription and replication, leading to the synthesis of positive and negative-stranded viral RNA (vRNA) in infected cells. Tools to visualize vRNA directly in infected cells are critical to analyze the viral replication cycle, screen for therapeutic molecules, or study infections in human tissue. Here, we report the design, validation, and initial application of FISH probes to visualize positive or negative RNA of SARS-CoV-2 (CoronaFISH). We demonstrate sensitive visualization of vRNA in African green monkey and several human cell lines, in patient samples and human tissue. We further demonstrate the adaptation of CoronaFISH probes to electron microscopy. We provide all required oligonucleotide sequences, source code to design the probes, and a detailed protocol. We hope that CoronaFISH will complement existing techniques for research on SARS-CoV-2 biology and COVID-19 pathophysiology, drug screening, and diagnostics.

Hiệu quả của phương pháp oxy hóa qua màng ngoài cơ thể (ECMO) trong hỗ trợ điều trị hội chứng suy hô hấp cấp nguy kịch trên bệnh nhân Covid

TÓM TẮT Sự bùng phát của hội chứng viêm đường hô hấp cấp do coronavirus 2 (SARS-CoV-2) nhanh chóng trở thành đại dịch trên toàn thế giới với hơn 40 triệu người mắc và hơn 1 triệu người chết tính đến ngày 17 tháng 10 năm 2020. Nhiều bệnh nhân COVID-19 được báo cáo cho thấy rằng có thể dẫn đến suy hô hấp cấp cần chăm sóc đặc biệt (ICU) và thiết bị hỗ trợ thở và bệnh cảnh có thể nhanh chóng tiến triển thành chứng suy hô hấp cấp (ARDS) với thiếu oxy ở mức độ nặng và gây ra tử vong dù đã có sự hỗ trợ của thiết bị hỗ trợ thở, cả 2 khả năng này thậm chí có thể cùng xảy ra. Các tổ chức quốc tế và các chuyên gia trong lĩnh vực này khuyến nghị sử dụng ECMO cho những bệnh nhân ARDS bị bệnh nặng có COVID-19. Tuy nhiên, tỷ lệ sống sót là rất thấp trong những trường hợp được sử dụng ECMO với COVID-19 trong đợt đầu tiên. Nghiên cứu của chúng tôi nhằm đánh giá kết quả bước đầu ứng dụng kỹ thuật ECMO trong hỗ trợ điều trị hội chứng suy hô hấp cấp nguy kịch trên bệnh nhân COVID-19 tại trung tâm hồi sức bệnh viện Trung ương Huế. ABSTRACT EFFECTIVENESS OF EXTRACORPOREAL MEMBRANE OXYGENATION (ECMO) IN THE TREATMENT OF ACUTE RESPIRATORY DISTRESS SYNDROME IN PATIENTS WITH COVID-19 The outbreak of acute respiratory syndrome caused by coronavirus 2 (SARS-CoV-2) quickly developed into a worldwide pandemic with more than 40 million people infected and more than 1 million dead as of October 17, 2020. Numerous patient reports COVID-19 can lead to acute respiratory failure requiring intensive care (ICU) and ventilators, and it can rapidly evolve into a certificate of acute respiratory failure (ARDS) with red oxygen in the heavy and death, despite the protective ventilator, even both. International organizations and experts in the field recommend ECMO for critically ill ARDS patients with COVID-19. However, survival is very low in the ECMO - corrected case series with COVID-19 during the first COVID-19 wave. Our study aimed to evaluate the results of the initial application of transmembrane oxygenation (ECMO) technique in the support of critical acute respiratory distress syndrome on COVID-19 patients at the hospital resuscitation center of Hue central hospital. Keywords: ECMO, ARDS, COVID-19.

Initial application of deep learning to borescope detection of endoscope working channel damage and residue

Background and study aims Outbreaks of endoscopy-related infections have prompted evaluation for potential contributing factors. We and others have demonstrated the utility of borescope inspection of endoscope working channels to identify occult damage that may impact the adequacy of endoscope reprocessing. The time investment and training necessary for borescope inspection have been cited as barriers preventing implementation. We investigated the utility of artificial intelligence (AI) for streamlining and enhancing the value of borescope inspection of endoscope working channels. Methods We applied a deep learning AI approach to borescope inspection videos of the working channels of 20 endoscopes in use at our academic institution. We evaluated the sensitivity, accuracy, and reliability of this software for detection of endoscope working channel findings. Results Overall sensitivity for AI-based detection of borescope inspection findings identified by gold standard endoscopist inspection was 91.4 %. Labels were accurate for 67 % of these working channel findings and accuracy varied by endoscope segment. Read-to-read variability was noted to be minimal, with test-retest correlation value of 0.986. Endoscope type did not predict accuracy of the AI system (P = 0.26). Conclusions Harnessing the power of AI for detection of endoscope working channel damage and residue could enable sterile processing department technicians to feasibly assess endoscopes for working channel damage and perform endoscope reprocessing surveillance. Endoscopes that accumulate an unacceptable level of damage may be flagged for further manual evaluation and consideration for manufacturer evaluation/repair.

Fluoride formed on enamel by fluoride varnish or gel application: A randomized controlled clinical trial

Although fluoride varnish (FV) and acidulated phosphate fluoride gel (APF-gel) are considered clinically effective to reduce caries, in vitro studies have shown that FV reacts slowly with enamel because most NaF present in the formulation is not solubilized in the FV. Therefore, we conducted a clinical study to evaluate if the time that FV remains on dental surfaces could overcome its slower chemical reactivity when compared with APF-gel. Sixty-eight volunteers were randomly allocated into four groups: Negative control (Control, no treatment), APF -gel application (1.23% F applied for 4 min), and FV application (Duraphat®, 2.26 % F) for 4 h (FV-4h) or 24 h (FV-24h). To evaluate fluoride formed and retained on enamel, acid biopsies were made on the buccal surfaces of the maxillary central incisors before, at the end of the application of fluoride products (immediately after gel application, or after 4 or 24 h of varnish application) and after 7 and 28 days. Fluoride concentration in dental biofilm was also analyzed before and up to 28 days after initial application. The data were analyzed by 2-way ANOVA, considering treatment and time as factors. The APF-gel and FV-24h groups formed greater fluoride concentration on enamel than the FV-4h and the control group at the end of application (p=0.0001), with no difference from each other (p=0.99). The groups did not differ regarding fluoride in biofilm, fluid (p=0.73) and solids (0.40). In conclusion, fluoride varnish needs to remain in contact with the teeth for prolonged times (>4 h) to reach the same reactivity obtained by a 4-min application of APF-gel.

Antimicrobial property of recombinant Lactolisterin BU in vitro and its initial application in pork refrigerated storage

Lactolisterin BU is a novel bacteriocin identified from Lactococcus lactis in 2017. It exhibits antimicrobial activity against food spoilage and foodborne pathogens. In this study, Lactolisterin BU was expressed in Pichia pastoris (P.pastoris) and isolated from the supernatant of yeast culture for the first time. It was found to exhibit a broad antimicrobial spectrum and rapid bactericidal activity against foodborne bacterial pathogens, both gram-positive and gram-negative ones, with minimum inhibition concentrations ranging within 10–60 μg/mL. The recombinant Lactolisterin BU (rLactolisterin BU) also had an antioxidant effect and was resistant to heating, acid–base, and high-dose-saline treatments and barely had any hemolytic activity or cytotoxicity. Moreover, rLactolisterin BU effectively suppressed the growth of bacterial pathogens; suppressed the increases in pH, total volatile basic nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS) of pork samples; and maintained a high quality of fresh pork during storage at 4 ℃. Furthermore, rLactolisterin BU effectively inhibited the growth of three kinds of bacteria in a pork-spoilage model. Taken together, rLactolisterin BU could be a promising preservative for food storage.

Estimating cloud condensation nuclei concentrations from CALIPSO lidar measurements

We present a novel methodology to estimate cloud condensation nuclei (CCN) concentrations from spaceborne CALIPSO lidar measurements. The algorithm utilizes (i) the CALIPSO-derived backscatter and extinction coefficient, depolarization ratio, and aerosol subtype information, (ii) the normalized volume size distributions and refractive indices from the CALIPSO aerosol model, and (iii) the MOPSMAP optical modelling package. For each CALIPSO height bin, we first select the aerosol-type specific size distribution and then adjust it to reproduce the extinction coefficient derived from the CALIPSO retrieval. The scaled size distribution is integrated to estimate the aerosol number concentration which is then used in the CCN parameterizations to calculate CCN concentrations at different supersaturations. To account for the hygroscopicity of continental and marine aerosols, we use the kappa parameterization and correct the size distributions before the scaling step. We have studied the sensitivity of the thus derived CCN concentration to the effect of variations of the initial size distributions. It is found that the uncertainty associated with the algorithm can range between a factor of 2 and 3. We have also compared our results with the POLIPHON and found comparable results for extinction coefficients larger than 0.05 km−1. An initial application to a case with coincident airborne in-situ measurements for independent validation shows promising results and illustrates the potential of CALIPSO for constructing a global height-resolved CCN climatology.

Reactive Hyperemia-Triggered Wrist Pulse Analysis for Early Monitoring of Young Men with High Atherosclerotic Risk

The high prevalence of cardiovascular disease in young adults has raised significant concern regarding the early identification of risk factors to allow for timely intervention. This study aimed to identify young males at risk of atherosclerosis using a noninvasive instrument and an initial application percussion entropy analysis of the wrist pressure pulse (WPP). In total, 49 young males aged 18 to 28, without any known history of vascular disease, were recruited. Blood samples were obtained whereby a TC/HDL cutoff value of 4 was used to divide the young men into low-risk (Group 1, TC/HDL < 4, N = 32) and high-risk (Group 2, TC/HDL ≥ 4, N = 17) groups regarding atherosclerosis. The reactive hyperemia-triggered WPPs were measured using a modified air-pressure-sensing system (MAPSS). The dilation index (DI) of the endothelial function and percussion entropy index (PEI) of the heart rate variability (HRV) assessments, calculated using pragmatic signal-processing techniques, were compared between the two groups. The nonparametric Mann–Whitney U test showed that the DI and PEI of the two groups showed statistical differences (both p < 0.05). Not only could the MAPSS assess endothelial function and HRV in young males, but the results also showed that waist circumference and PEI may serve as indicators for the early identification of young males at risk of atherosclerosis.

Hollow Glass Spheres HGS in Drilling Fluid: Case Study of Preventing and Mitigating Total Losses

The paper describes the first deployment of HGS in Eastern Siberia as a mud additive. The technology was utilized for reducing drilling fluid density for prevention and mitigation of losses; while drilling through a producing reservoir section with low pore pressure, unconsolidated and fractured sands. The engineering considerations, fundamentals of the approach and major risks involved were reviewed with application to the Sredneboutobinskoye Oilfield as a pilot field application for broader future plans. Key planning, delivery and execution principles of the initial application will be reported in the paper. Initially deployed on three wells, including multi-laterals (Rylance et al., 2021), the paper will walk through the engineering considerations during the planning and execution phases. Key sections include the data gathered and the many lessons learned during the incremental and stepwise deployment. The paper will also report on post drilling productivity and comparisons with the offset wells drilled with conventional mud systems, which suffered severe losses. The results of this pilot have exceeded expectations. There have been many insights and the Team are now looking to set a timetable to scale-up across the Taas-Yuryakh Neftegazodobycha (TYNGD). After many hours of laboratories study and preparation works, the general plan was to reduce the static density and ECD to mitigate fluid losses. However, the applied results showed additional effects from HGS. Data will be provided that demonstrated loss-free drilling was achieved where this had not been the case before, with a material reduction in NPT, lost circulation material (LCM) needs and costs. Much has been learned, recovered HGS material has been demonstrated to be an effective LCM pill and centralization of mud processing may offer additional cost savings and improvements. Further efficiencies are also expected to be achieved and future potential is considerable. HGS for cementing is well documented, yet application for drilling fluids has been less well reported and almost exclusively related to single wells. The TYNGD application is innovative as this is a major development with 10 active drilling rigs. The application is on multi-laterals and offset wells are available for direct comparison. The results of the approach demonstrate a new way of performing well construction in an effective manner for major field developments where losses are prevalent.