During the coronavirus disease 2019 (COVID-19) pandemic, COVID-19 testing is crucial, as it enables early detection and halting the spread of infection throughout the community. Real-time reverse-transcriptase polymerase chain reaction (Real-time RT-PCR) testing is the predominant method for COVID-19 testing, and the cycle threshold value (Ct value) is used to determine COVID-19 positivity. There are many ongoing studies using Ct value, and the present study aims to examine time series distribution during the pandemic using Ct values at the national level and analyze the association with time-varying reproduction number (Rt) to discuss the utilization of laboratory-based COVID-19 test results. We used Real-time RT-PC results collected by Seegene Medical Foundation from the index case in Korea in February 2020 to January 2022 in Korea. The distribution of daily Ct value ( RdRp/S target) was examined, and it was compared with the daily count of newly diagnosed cases and Rt to determine the usability of Ct values. Moreover, time lag was applied to the daily count of newly diagnosed cases to analyze the association between Ct values and Rt. During the COVID-19 pandemic, Ct values declined in general, while viral load increased progressively. After Ct values dropped markedly, the number of newly diagnosed cases rose substantially, and the association analysis also confirmed that the daily count of newly diagnosed cases declined with increasing Ct values. The time series trend of the Ct values was also similar to that of Rt, a classic marker used as a predictor of the trends of the pandemic, and when compared to the actual count of newly diagnosed cases, Ct values can be used to predict new diagnoses earlier than Rt. The fact that the Ct values were more sensitive to a substantial rise of new COVID-19 cases than Rt was in the early days of the pandemic also support this. We examined the potential of Ct values as a predictor of new COVID-19 cases in real-time using nationally collected Ct value data. Further, we proposed the use of Ct values as an index reflecting the degree of viral load, so the findings of this study can be used as valuable evidence to support public health decisions for response and resource distribution.

A document by Manh Tuan Hoang. Click on the document to view its contents.

This is a case of a 37-year-old man suffering from worsening exertional dyspnea detected left artial myxoma 92×43 mm. Radical mass resection and mitral annuloplasty were performed simultaneously. Giant left atrial myxoma causing mitral regurgitation through mitral annulus dilatation without affecting leaflet function is rarely reported.

Background: There has been a strong demand for N95 filtering facepiece respirators and surgical masks during respiratory infection pandemics, particularly for the frontline healthcare workers who are at risk of high exposure to biological hazards and for the patients seeking care who may be potentially transmitting the respiratory viruses through air. Respirators and masks are pivotal to meet the requirements of filtration efficiency and fitting characteristics for the users’ protection. Objective: The goals of this study were to systematically review the fit testing passing rates and identify the factors influencing the fitting characteristics. Methods Potentially relevant studies were identified using PubMed, Scopus, Web of Science, Science Direct, one scientific website (cdc.gov), and one scientific journal (ISRP.com) during the COVID-19 pandemic from February 5, 2020 to January 2, 2023. Meantime, the gray literature search was performed. Results: A number of studies conducted regarding the fit testing showed that low proportions of passing quantitative fit testing among the studied masks or respirators. Factors such brand, style, and gender were found to be influenced the respirator fit testing. Conclusion: This systematic review supports the importance of optimal fit testing for the healthcare workers with high-risk procedures. Manufacturers supply a variety of the mask/ respirator brands, models, styles, and sizes to ensure the expected respiratory protection for the end-users. The proper donning and doffing and reliable fit testing are other affective strategies for improving fitting. Some modifications / substitutions on components of fit testing procedures could be considered during pandemics of respiratory infections.

Aim: The objective of this study was to evaluate the safety, pharmacokinetics, and pharmacodynamics of SHR2285, a novel small molecule FXIa inhibitor, in Chinese healthy volunteers. Methods: The study consisted of single ascending doses part (part A: 25 - 600 mg) and multiple ascending doses part (part B: 100, 200, 300, and 400 mg). In both parts, subjects were randomized in a 3:1 ratio to receive SHR2285 or placebo. Plasma and urine samples were collected to describe its pharmacokinetics and pharmacodynamics (PD) profile. Results: SHR2285 were well tolerated. SHR2285 was absorbed rapidly with median Tmax of 1.50 to 3.00 h. The geometric median of t1/2 of SHR2285 varied from 8.74-12.1 h across 25 to 600 mg single dose. Total systemic exposure of metabolite SHR164471 was approximately 1.77-3.61 fold that of the parent drug. The plasma concentration of SHR2285 and SHR164471 reached steady state by the morning of Day 7 with low accumulation ratio (0.956-1.20 and 1.18-1.56 respectively). The increase in PK exposure of SHR2285 and SHR164471 was less than dose proportional. Food has minimal effect on the pharmacokinetics of SHR2285 and SHR164471. SHR2285 produced an exposure dependent prolongation of APTT, and decrease in FXI activity. The maximum FXI activity inhibition rate (geometric mean) at steady state was 73.27%, 85.58%, 87.77% and 86.27% for 100 to 400 mg, respectively. Conclusions: SHR2285 exhibit a predictable PK profile and exposure related PD profile. These results suggest that SHR2285 is a promising novel oral FXI inhibitor warranting further evaluation.

Dear Editor, We read with great interest the article recently published in Journal of Cardiovascular Electrophysiology, “Left atrial appendage dimension predicts elevated brain natriuretic peptide in nonvalvular atrial fibrillation” by Cook JA. et al. 1 The authors have studied the relation between Brain natriuretic peptide (BNP) elevations and left atrial appendage measurements in patients who referred for left atrial appendage (LAA) occlusion in patients with nonvalvular atrial fibrillation (AF). BNP release is largely from the ventricles and it is also dynamically dependent on myocardial stretch and fluid volume status. However, it seems difficult to prove that BNP levels are directly related to the LAA measurements. Correlating BNP elevation only with left atrial or LAA measurements means ignoring left ventricular strain. Considering that these patients were referred for LAA occlusion and had a high CHA 2DS 2-VASc score, and not taking heart failure with preserved ejection fraction into account may lead to errors in interpreting the results. Moreover, it should be evaluated that the left atrial appendage may undergo remodeling or enlargement as a result of the left ventricular end-diastolic pressure increase. In this case, although the study is valuable, remains a cross-sectional study and a snapshot of the correlation of BNP and LAA. Second, it should be disclosed whether patients have paroxysmal or chronic AF and how long the patient has had AF. A relationship was established between LAA dimensions and BNP in the study, it is essential that the duration of AF should be considered and subgroup analyses should be evaluated if possible, since AF has a significant effect on BNP release. We appreciate this study and believe that a more detailed evaluation including left ventricular evaluation and prospectively monitored LAA and BNP would yield more realistic results. In addition, we think that it would be useful to evaluate midregional pro-A-type natriuretic (MR-proANP) in LAA studies, which is specific to the left atrial enlargement and similar physiology to BNP. 2

In this study, a generalized nonlinear local fractional Lighthill-Whitham-Richards (LFLWR) model has been developed. The local fractional variational iteration method (LFVIM) solves and analyzes the proposed model. Numerous works have been described in past to address linear LWR and linear LFLWR models. This research highlighted on generalized nonlinear LFLWR model and LFVIM is employed to derive non-differentiable solutions of the suggested model. The existence and uniqueness of the resolution of LFLWR model have also been established. Furthermore, several exemplary instances are discussed to demonstrate the success of implementing LFVIM to the proposed model. The numerical simulations for each of the cases have also been shown. Additionally, the obtained solutions of the suggested model have been compared with the solutions of the classical LWR model with non-differentiable conditions in few examples. The study demonstrates that the employed iterative scheme is quite efficient and can be utilized for obtaining the non-differentiable solution to proposed generalized nonlinear LFLWR model of traffic flow.

The development of mega constellations inevitably brings various problems for the development of routing techniques. Most of the existing work considers end-to-end delay and load balancing problems, while the analysis of routing strategies in case of link performance degradation is neglected, and an optimization approach applicable to mega satellite networks is not developed. In this letter, we propose a robust routing strategy based on deep reinforcement learning (RRS-DRL) that regards the Age of Information (AoI) of packets as an optimization target, and ensures the effectiveness of message transmission throughout the network. Extensive simulation results show that our proposed RRS-DRL algorithm obtains a lower average AoI across the network and better utilization of the resources than the traditional shortest path algorithm, significantly increasing the robustness of the constellation.

The tracking and data relay satellite (TDRS) in the geosynchronous orbit (GEO) is capable of providing ranging and communication services for user spacecraft in low Earth orbit (LEO) through the inter-satellite link (ISL). The time delay of TDRS’ ISL transponder in orbit differs from that before launch and changes due to complex space environment, which contributes non-negligible errors to user spacecraft’s orbit determination based on the four-way ranging data. We construct a calibration system and propose an efficient on-orbit calibration method for time delay of ISL transponder in TDRS. Experimental results verify the effectiveness of the proposed method and the RMS of calibration residuals is less than 0.5 meters.

A document by Celine Galleani. Click on the document to view its contents.

In this paper, a 2-bit digital reflection-type phase shifter working at 120 GHz is presented. It uses a compact coupled-lines coupler with low insertion loss and high isolation over a wide bandwidth. The loads are made by a microstrip-line loaded by three PIN diodes whose states are tuned ON/OFF to obtain 90°, 180° and 270° phase shift relative to the reference (0°). Measurement results show RMS phase and amplitude error equal to 10.3° and 1.2 dB, respectively. The maximum insertion loss is equal to 8.6 dB, leading to a figure of merit of 31°/dB. As shown by simulation, by flipping PIN diodes and use negative voltage for biasing, the maximum insertion loss could be reduced to 3.6 dB (figure of merit of 75°/dB) along with a great improvement in RMS phase and amplitude errors, thus showing the potential of the proposed architecture.

Aims: To improve the countermeasures of clinical trial institutions against major public health events such as COVID-19. Methods: A questionnaire was created to investigate the effects of the global static management policy against COVID-19 on clinical trials in Shanghai in 2022. And the convenience sampling combined with snowball sampling were adopted to interview clinical research coordinators (CRC) and clinical research associates(CRA) on the platform of SOJUMP as well as WeChat. Results: 156 valid questionnaires were collected, with an effective recovery rate of 93.98%. 98.07% of the respondents believed that the effects was severe. The extent of effects on different links of clinical trials was different (rank sum test P<0.01), being great on medication/follow-up (76.28% of significant effects), monitoring/audit (74.36%) and screening/admission (71.79%).The protocol deviations associated with out of visit window (experienced by 94.23% of respondents, during the static management policy), inspection (78.85%), medication (67.95%) and withdrawal (62.82%). And the interviewees reported 49.66% of the exclusion should blame the epidemic situation. The development of online-office or remote-ethics meetings alleviated the impact of lockdown policy on approval/ethics/contract and data cleaning/site closing. 90.98% of oral drugs could be sent by express delivery, but only 1.28% had the experience of online informed consent and remote inspection. Conclusions: We shall speed up the application of the intelligent clinical trial system and remote monitoring system, realize the transformation to a new model of patient-centered clinical trial, and improve the ability to cope with major public health events such as COVID-19.

Comprehending speech in noisy situations is difficult and suffers with aging, hearing loss, and cognitive decline. Using visual speech cues improves perception and comprehension of speech in noise (SiN) in older adults with hearing impairment. In the current study we investigated neurofunctional correlates (i.e., neural tracking of speech) of the visual enhancement effect in a naturalistic setting in which older adults with hearing impairment (N=67) listened to sentences in babble noise in audio-only and audiovisual conditions and performed an intelligibility and a comprehension task, while EEG was recorded. Behaviorally, we found that visual speech cues improved intelligibility and comprehension of speech presented in babble noise and that particularly individuals with high working memory capacity benefitted. Furthermore, we found that the visual enhancement effect was accompanied by increased cortical tracking of the speech envelope particularly in individuals who were low performers in the audio-only condition (i.e., < 70% correct) leading to improved speech in noise comprehension in an audiovisual setting. Further, these low auditory-only performers showed deficient neural speech tracking in a right auditory topographical cluster, which improved significantly when visual speech cues were presented leading to more bilateral processing of speech. Overall, our results show that older adults with hearing impairment who have difficulties with speech in noise perception use visual speech cues to improve performance which is reflected in more bilateral processing of speech.

Objective: To evaluate patient and healthcare system factors in telemedicine utilization in a large, diverse population. Data Sources and Study Setting: Retrospective study of patient visits across Kaiser Permanente Southern California between January 1, 2019, and June 30, 2021. Study Design: Patient factors included age, gender, ethnicity, median household income, primary spoken/written language, marital status, and registration on kp.org. Healthcare factors included type of visit, provider age, gender, specialty, number of years in practice and primary language. Data Collection/Extraction Methods: Rates of utilization compared between office and virtual visits, prior to and after March 2020, with an interrupted time series and slope analysis. Principal Findings: There were 177,171,288 visits during the study period. There was a decrease in patient visits after March 2020 (lockdown), driven by a sharp decline in office visits. Within three months of lockdown, total visits increased until the end of study, at 2.8 million/month, compared to 2.5 million/month prior to lockdown, driven by office visits that approached pre-lockdown and high telemedicine visits. In a multivariate regression analysis, there were no significant differences in patient age, race, gender, income, marital status, language, and kp.org registration in telemedicine utilization. Providers with 6-10 years in practice, aged < 30 utilized the most telemedicine (p=.01). General surgery, medical specialties, OBGYN, pediatrics and psychiatry utilized more telemedicine compared to primary care, but podiatry and surgical specialties utilized less (p < 0.01). Conclusions: In a large, diverse patient population, no significant healthcare disparities were found in telemedicine utilization, contrary to what most current literature shows. Results of this study may prompt more investigation to the role of telemedicine in various populations.

The 18O enrichment (Δ 18O) of leaf water affects the Δ 18O of photosynthetic products such as sucrose, generating an isotopic archive of plant function and past climate. However, uncertainty remains regarding how leaf water compartmentation between photosynthetic and non-photosynthetic tissue affects the relationship between Δ 18O of bulk leaf water (Δ 18O LW) and leaf sucrose (Δ 18O Sucrose). We grew Lolium perenne (a C 3 grass) in mesocosm-scale, replicated experiments with daytime relative humidity (RH 50 or 75%) and CO 2 level (200, 400 or 800 μmol mol -1) as factors, and determined Δ 18O LW, Δ 18O Sucrose and morpho-physiological leaf parameters, including transpiration ( E leaf), stomatal conductance ( g s) and mesophyll conductance to CO 2 ( g m). The Δ 18O of photosynthetic medium water (Δ 18O SSW) was estimated from Δ 18O Sucrose and the equilibrium fractionation between water and carbonyl groups (ε bio). Δ 18O SSW was well predicted by theoretical estimates of leaf water at the evaporative site (Δ 18O e) with adjustments that correlated with gas exchange parameters ( g s or total conductance to CO 2). Isotopic mass balance and published work indicated that non-photosynthetic tissue water was a large fraction (~0.53) of bulk leaf water. Δ 18O LW was a poor proxy for Δ 18O Sucrose, mainly due to opposite Δ 18O responses of non-photosynthetic tissue water (Δ 18O non-SSW) relative to Δ 18O SSW, driven by atmospheric conditions.

Aims: This review aims to evaluate prospective controlled trials of primary prevention of anthracycline cardiotoxicity in paediatric cancer patients. Methods and Results: Prospective controlled trials in which any cardioprotective agent was compared to no additional therapy or placebo in paediatric cancer patients receiving anthracyclines (PROSPERO: CRD42022367791). Outcomes were assessed using random and fixed-effects meta-analysis models as well as a synthesis without meta-analysis approach. A total of 24 reports of 19 trials were included in our review, 11 trials administered dexrazoxane, two trials administered the angiotensin converting enzyme inhibitor enalapril, one trial administered the beta-blocker carvedilol, one omega-3 fatty acids, one coenzyme Q10, one amifostine, one silymarin and one black seed oil. A total of 1333 paediatric patients receiving anthracyclines were included in meta-analysis of the cardio-protective effect of dexrazoxane in reducing the risk of developing significant systolic dysfunction. A risk ratio of 0.44 (95% CI: 0.33 to 0.61; I2 = 0%) was found, showing that the administration of dexrazoxane was highly effective. Overall, enalapril, carvedilol and dexrazoxane resulted in less left ventricular dysfunction and fewer cardiac biomarker abnormalities compared to placebo. Omega-3 fatty acids, silymarin and black seed oil each demonstrated benefit through less reduction of systolic function and fewer cardiac biomarker abnormalities. Conclusion: Enalapril and dexrazoxane are highly effective in preventing the anthracycline-induced cardiotoxicity in paediatric cancer patients with a highly acceptable safety profile. More randomised-controlled trials are required to reach a conclusion on the efficacy of omega-3 fatty acids, co-enzyme Q10 and amifostine.

Childhood cancer survivors are at risk for late effects related to their cancer treatment, but little is known about clinical, and demographic associated with substance use behaviors. The purpose of this study is to examine the associations between substance use behaviors (tobacco, marijuana, e-cigarette, and alcohol) and cancer-related follow-up care, treatment intensity, late effects, depressive symptoms, self-rated health, race/ethnicity, and neighborhood socioeconomic status (nSES). Participants were from the Project Forward cohort, a population-based study of young adult survivors of childhood cancer. Participants (N=1,166, Mage=25.1 years) were recruited through the Los Angeles Cancer Surveillance Program (Cancer Registry covering Los Angeles County, California). Multivariate path analyses were performed with substance use as the outcome variables and clinical and demographic factors as independent variables. Covariates included age and gender. Substance use was positively associated with depressive symptoms, and inversely associated with cancer-related follow-up care, female gender, age, Hispanic ethnicity, treatment intensity, and self-rated health. Neighborhood SES was inversely associated with tobacco use, while being positively associated with binge drinking and e-cigarette use. The results highlight the interrelationship among the clinical and demographic variables and their associations with different substance use. Findings support effective interventions targeting integrative care and health promotion efforts for polysubstance use behavior among CCS. This will help improve long-term outcomes and mitigate the risk for early morbidity.

Hematological involvement in sarcoidosis is widely presented by lymphopenia and splenomegaly. However, the auto-immune hemolytic anemia associated to sarcoidosis is exceptionally reported in the literature. In this report we describe a novel observation of this situation.

The influence of pre-strain on the tensile and fatigue properties of a dual phase DP600 was studied. The material was pre-strained by uni-axial tension in rolling and transverse direction. Thereafter, specimens were cut from the deformed plates in parallel or orthogonal to pre-strain direction. It was found that pre-strain increases yield and tensile strength. Results suggested that strain path change primarily affects the elastic-plastic transition during early stage of reloading. Pre-strained specimens showed an increase in high cycle regimes as a consequence of yield strength increment, irrespective of imposed pre-straining direction. A modified stress life equation which accounts for pre-strain was proposed and showed good agreement with experimental data. Bake hardening enhanced both tensile and high cycle fatigue resistance. Walker equation was successfully fitted to account tensile mean stress. In low cycle fatigue, negligible influence of pre-strain was observed due to cyclic softening and residual stress relaxation.

1.1 Background Early in the SARS-CoV-2 pandemic, polymerase chain reaction (PCR) testing was reserved for symptomatic patients. However, many infections were asymptomatic or mildly symptomatic. Positive serologic antibody (Ab) testing is theorized to be a marker of prior infection, allowing for identification of true burden of disease and establishing links between outbreaks. 1.2 Objective Assess serologic testing in subjects after PCR testing and compare seropositivity rates of household vs. non-household close contacts. 1.3 Methods We identified subjects who were PCR-positive between March 2020 and May 2021. Index cases and close contacts then underwent serologic testing for IgG against SARS-CoV-2 nucleocapsid N-protein. 1.4 Results One-hundred-and-thirteen subjects underwent serologic testing with a sensitivity of 65.0%, specificity of 78.9%, positive predictive value of 92.9%, and negative predictive value of 34.9%. Index cases comprised 20.5% of subjects, and 73.9% were seropositive (p=0.01). Close contacts included 72% household contacts and 28% non-household contacts. One seropositive case had no prior PCR and four were PCR negative. No statistical difference existed in seropositivity between household and non-household contact (53.1% vs. 43.8%, p=0.4). 1.5 Conclusions Testing for IgG against SARS-CoV-2 N-protein may identify previously unrecognized infections in the community. Seropositivity rates of household vs. non-household contacts were not significantly different, and >50% of household contacts were seropositive.

Proactive antipredator behavior results from a mental construct of perceived predation risk, and drives prey’s strategies to avoid being killed while minimizing constraints to their activities. Under this reasoning, resource specialists may suppress antipredator strategies to access scarcely available key resources, while proactive antipredator behavior should be privileged by generalists or when resources are abundant. We quantified the relative effects of predation- (top-down) and resource-driven (bottom-up) constraints to spatiotemporal patterns of landscape use by a prey community in a dynamic system under low predator abundance, and investigated how prey manage the risk posed by predators with different hunting strategies. We fitted Royle-Nichols co-abundance models to camera trapping data collected between 2017 and 2019 in Bicuar National Park (Angola) to assess spatial association/segregation across predator-prey dyads, while accounting for the effects of water and food availability during dry and wet seasons. We further estimated pairwise seasonal differences in diel activity overlap between predator and prey.Our results depict a generalized pattern of predator-prey spatial co-abundance, independent of predator’s hunting strategy or prey’s importance in the predator’s diet, even overriding the effects of water and forage availability. Further, we found prey to have higher activity overlap with the ambush than with the cursorial predator, with little influence of the season or prey preference. We failed to detect spatiotemporal proactive antipredator responses either towards the cursorial or ambush predator. The community-wide predator-prey association patterns we found support that predation pressure is insufficient to displace prey from their preferred habitats or to adjust their endogenous clock, and support predominantly bottom-up regulated behaviors. We suggest that, in landscapes where predator density is low, limited perception of risk may prevent the employment of proactive antipredator behavior, likely relegating prey to rely on reactive responses to short-term predation risk.

Rabies, a fatal zoonotic viral encephalitis kills tens of thousands of people each year in India, representing one third of the estimated global rabies burden. A detailed understanding of the molecular epidemiology of the Rabies lyssavirus (RABV) in India is limited due to the low availability of sequences from the country. In this study we examined the feasibility of direct sequencing of clinical samples (archived human and canine brain tissues, 10 each), for detection and recovery of whole genome sequences of RABV, on the MinION – single molecule nanopore sequencing device. Using an amplicon-based approach, complete RABV genomes were recovered from all the 20 samples, archived from 2003 to 2019, from 4 southern states of India. Phylogenetic analysis revealed that all 20 sequences from this study belonged to the Arctic-like (AL) 1a lineage. Divergence estimation of sequences revealed that all the circulating RABV strains within India are diverged in last 60 years from the previous ancestor. The genetic relatedness and close clustering of the sequences in the study suggests the continued propagation of AL1a in the region, across state boundaries. Genomic surveillance can provide unique insights into rabies spread and persistence that can direct control efforts in India.

We reported the first case of Guillain-Barré syndrome that is associated with COVID-19 and malaria coinfection. The current report demonstrates diagnostic challenge to identify GBS case in a country like Sudan that is endemic with several infectious diseases associated with developing GBS.

Trauma or surgery to the lower limbs can cause fat from the marrow within the leg bones to enter the bloodstream and form an embolus. However, if there is cerebral involvement without any pulmonary or dermatological manifestations at diagnosis, it could delay identifying cerebral fat embolism (CFE).