Efficacy and safety of auto-cross-linked hyaluronic gel to prevent intrauterine adhesion after hysteroscopic electrosurgical resection: a multi-center randomized controlled trial.

Background: The electrothermal effect of hysteroscopic bipolar electrosurgical resection may cause damage to the endometrium, leading to intrauterine adhesion (IUA). Although some studies have demonstrated the efficacy and feasibility of auto-cross-linked hyaluronic (ACP) gel in preventing IUAs, controversy over its use continues. In this randomized controlled multi-center 2-arm parallel trial, we aimed to examine the efficacy and safety of ACP gel in preventing IUA after hysteroscopic electrosurgical resection and facilitate pregnancy in patients. Methods: Patients from 4 centers in China were randomly assigned (1:1) to receive an intrauterine infusion of ACP gel or nothing after hysteroscopic electrosurgical resection. The randomization assignment was generated by computer and kept in a sealed envelope. A second-look hysteroscopy was performed within 3 months of the surgery. Results: From June 2018 to May 2021, 200 patients were recruited. Ultimately, 82 patients in both groups were included in the result analysis. The baseline characteristics were comparable. The outcomes were assessed by using per-protocol analysis. The incidence of IUA in the ACP gel group was lower than that in the control group [3.66% vs. 10.98%, risk ratio (RR) =0.333, 95% confidence interval (CI): 0.094-1.187, P=0.072], and the planned pregnancy rate was higher than that of the control group (60.98% vs. 40.54%, RR =1.504, 95% CI: 0.949-2.384, P=0.071), but the difference was not statistically significant. There was no significant difference in menstruation change. Menstrual volume remained unchanged in most cases (86.59% in ACP gel group vs. 89.02% in the control group, RR =0.877, 95% CI: 0.877-1.109, P=0.815). Menstrual volume decreased in 10 women in the ACP gel group and 8 in the control group (12.20% vs. 9.76%, RR =1.250, 95% CI: 0.520-3.007, P=0.617). No adverse effects were observed after the ACP administration. Conclusions: The present study showed that the use of ACP gel appeared to reduce both the tendency of IUA and American Fertility Society (AFS) scores and improve the subsequent pregnancy rate during hysteroscopic electrosurgical resection when treating polyps, fibroids, and uterine septum. ACP might be recommended to prevent IUA after such surgery. Further studies should be conducted with larger numbers of participants. Trial Registration: Chinese Clinical Trial Registry ChiCTR2100047165.

A human iPSC-array-based GWAS identifies a virus susceptibility locus in the NDUFA4 gene and functional variants.

Population-based studies to identify disease-associated risk alleles typically require samples from a large number of individuals. Here, we report a human-induced pluripotent stem cell (hiPSC)-based screening strategy to link human genetics with viral infectivity. A genome-wide association study (GWAS) identified a cluster of single-nucleotide polymorphisms (SNPs) in a cis-regulatory region of the NDUFA4 gene, which was associated with susceptibility to Zika virus (ZIKV) infection. Loss of NDUFA4 led to decreased sensitivity to ZIKV, dengue virus, and SARS-CoV-2 infection. Isogenic hiPSC lines carrying non-risk alleles of SNPs or deletion of the cis-regulatory region lower sensitivity to viral infection. Mechanistic studies indicated that loss/reduction of NDUFA4 causes mitochondrial stress, which leads to the leakage of mtDNA and thereby upregulation of type I interferon signaling. This study provides proof-of-principle for the application of iPSC arrays in GWAS and identifies NDUFA4 as a previously unknown susceptibility locus for viral infection.

Undiagnosed HIV Infections May Drive HIV Transmission in the Era of "Treat All": A Deep-Sampling Molecular Network Study in Northeast China during 2016 to 2019.

Universal antiretroviral therapy (ART, "treat all") was recommended by the World Health Organization in 2015; however, HIV-1 transmission is still ongoing. This study characterizes the drivers of HIV transmission in the "treat all" era. Demographic and clinical information and HIV pol gene were collected from all newly diagnosed cases in Shenyang, the largest city in Northeast China, during 2016 to 2019. Molecular networks were constructed based on genetic distance and logistic regression analysis was used to assess potential transmission source characteristics. The cumulative ART coverage in Shenyang increased significantly from 77.0% (485/630) in 2016 to 93.0% (2598/2794) in 2019 (p < 0.001). Molecular networks showed that recent HIV infections linked to untreated individuals decreased from 61.6% in 2017 to 28.9% in 2019, while linking to individuals with viral suppression (VS) increased from 9.0% to 49.0% during the same time frame (p < 0.001). Undiagnosed people living with HIV (PLWH) hidden behind the links between index cases and individuals with VS were likely to be male, younger than 25 years of age, with Manchu nationality (p < 0.05). HIV transmission has declined significantly in the era of "treat all". Undiagnosed PLWH may drive HIV transmission and should be the target for early detection and intervention.

High-fidelity Cas13 variants for targeted RNA degradation with minimal collateral effects.

CRISPR-Cas13 systems have recently been used for targeted RNA degradation in various organisms. However, collateral degradation of bystander RNAs has limited their in vivo applications. Here, we design a dual-fluorescence reporter system for detecting collateral effects and screening Cas13 variants in mammalian cells. Among over 200 engineered variants, several Cas13 variants including Cas13d and Cas13X exhibit efficient on-target activity but markedly reduced collateral activity. Furthermore, transcriptome-wide off-targets and cell growth arrest induced by Cas13 are absent for these variants. High-fidelity Cas13 variants show similar RNA knockdown activity to wild-type Cas13 but no detectable collateral damage in transgenic mice or adeno-associated-virus-mediated somatic cell targeting. Thus, high-fidelity Cas13 variants with minimal collateral effects are now available for targeted degradation of RNAs in basic research and therapeutic applications.

Lysozyme Protects Against Severe Acute Respiratory Syndrome Coronavirus 2 Infection and Inflammation in Human Corneal Epithelial Cells.

Purpose: The purpose of this study was to investigate the effects of lysozyme, an antimicrobial enzyme found in tears that protects the eye against pathogens, on pseudotyped severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection through corneal epithelial cells. Methods: The expression of the angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease (TMPRSS2) in human corneal epithelial cells (HCECs) was measured by RT-PCR and Western blotting. The altered expression of the pro-inflammatory molecules induced by spike protein and lysozyme was analyzed by RT-PCR. Cell toxicity was tested by CCK8 assay. The cell entry of SAR-CoV-2 in HCECs and primary rabbit corneal epithelial cells (RbCECs) was detected by luciferase assay. Results: ACE2 and TMPRSS2 were highly expressed in HCECs. The spike proteins of SARS-CoV-2 stimulated a robust inflammatory response in HCECs, characterized by increased secretion of pro-inflammatory molecules, including IL-6, TNF-α, iNOS, and MCP-1, and pretreatment with lysozyme in HCECs markedly decreased the production of proinflammatory molecules induced by spike proteins. In addition, the inflammatory cytokine TNF-α enhanced the entry of SARS-CoV-2 into HCECs, which can be mitigated by pretreatment with lysozyme. Conclusions: In this study, we analyzed the susceptibility of human corneal epithelial cells to SARS-CoV-2 infection and suggested the protective effects of lysozyme on SARS-CoV-2 infection.

Highly Sensitive Detection Method for HV69-70del in SARS-CoV-2 Alpha and Omicron Variants Based on CRISPR/Cas13a.

As SARS-CoV-2 variants continue to evolve, identifying variants with adaptive diagnostic tool is critical to containing the ongoing COVID-19 pandemic. Herein, we establish a highly sensitive and portable on-site detection method for the HV69-70del which exist in SARS-CoV-2 Alpha and Omicron variants using a PCR-based CRISPR/Cas13a detection system (PCR-CRISPR). The specific crRNA (CRISPR RNA) targeting the HV69-70del is screened using the fluorescence-based CRISPR assay, and the sensitivity and specificity of this method are evaluated using diluted nucleic acids of SARS-CoV-2 variants and other pathogens. The results show that the PCR-CRISPR detection method can detect 1 copies/µL SARS-CoV-2 HV69-70del mutant RNA and identify 0.1% of mutant RNA in mixed samples, which is more sensitive than the RT-qPCR based commercial SARS-CoV-2 variants detection kits and sanger sequencing. And it has no cross reactivity with ten other pathogens nucleic acids. Additionally, by combined with our previously developed ERASE (Easy-Readout and Sensitive Enhanced) lateral flow strip suitable for CRISPR detection, we provide a novel diagnosis tool to identify SARS-CoV-2 variants in primary and resource-limited medical institutions without professional and expensive fluorescent detector.

SARS-CoV-2 Infection Induces Ferroptosis of Sinoatrial Node Pacemaker Cells.

BACKGROUND: Increasing evidence suggests that cardiac arrhythmias are frequent clinical features of coronavirus disease 2019 (COVID-19). Sinus node damage may lead to bradycardia. However, it is challenging to explore human sinoatrial node (SAN) pathophysiology due to difficulty in isolating and culturing human SAN cells. Embryonic stem cells (ESCs) can be a source to derive human SAN-like pacemaker cells for disease modeling. METHODS: We used both a hamster model and human ESC (hESC)-derived SAN-like pacemaker cells to explore the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on the pacemaker cells of the heart. In the hamster model, quantitative real-time polymerase chain reaction and immunostaining were used to detect viral RNA and protein, respectively. We then created a dual knock-in SHOX2:GFP;MYH6:mCherry hESC reporter line to establish a highly efficient strategy to derive functional human SAN-like pacemaker cells, which was further characterized by single-cell RNA sequencing. Following exposure to SARS-CoV-2, quantitative real-time polymerase chain reaction, immunostaining, and RNA sequencing were used to confirm infection and determine the host response of hESC-SAN-like pacemaker cells. Finally, a high content chemical screen was performed to identify drugs that can inhibit SARS-CoV-2 infection, and block SARS-CoV-2-induced ferroptosis. RESULTS: Viral RNA and spike protein were detected in SAN cells in the hearts of infected hamsters. We established an efficient strategy to derive from hESCs functional human SAN-like pacemaker cells, which express pacemaker markers and display SAN-like action potentials. Furthermore, SARS-CoV-2 infection causes dysfunction of human SAN-like pacemaker cells and induces ferroptosis. Two drug candidates, deferoxamine and imatinib, were identified from the high content screen, able to block SARS-CoV-2 infection and infection-associated ferroptosis. CONCLUSIONS: Using a hamster model, we showed that primary pacemaker cells in the heart can be infected by SARS-CoV-2. Infection of hESC-derived functional SAN-like pacemaker cells demonstrates ferroptosis as a potential mechanism for causing cardiac arrhythmias in patients with COVID-19. Finally, we identified candidate drugs that can protect the SAN cells from SARS-CoV-2 infection.

The Impact of COVID-19-Related Work Stress on the Mental Health of Primary Healthcare Workers: The Mediating Effects of Social Support and Resilience.

OBJECTIVE: The psychological condition of healthcare workers since the COVID-19 pandemic has attracted the attention of many studies. However, few have reported on psychosocial problems of primary healthcare workers in the COVID-19 pandemic. This study aimed to examine the mediating roles of social support and resilience in COVID-19-related work stress and symptoms of anxiety and depression. METHODS: A total of 840 primary healthcare workers in 17 community health centers in Guangzhou, China, were recruited from May to July 2021. Data on demographic characteristics, COVID-19-related work stress, social support, resilience, anxiety and depression were collected. A structural equation model was used for mediation analysis. RESULTS: More than half of participants reported mild or more severe (at least borderline abnormal) symptoms of anxiety (68.1%) and depression (55.6%). Social support and resilience mediate the association between COVID-19-related work stress and symptoms of anxiety and depression, respectively. Furthermore, the association between work stress and symptoms of anxiety and depression was also mediated by an accumulation of social support and resilience. The indirect effect of COVID-19-related work stress on anxiety and depression through resilience was much greater than other indirect effects. CONCLUSION: Anxiety and depression were prevalent among primary healthcare workers. This study highlights the psychological impact of the COVID-19-related psychosocial work environment on primary healthcare workers. There is an urgent need to improve working conditions for primary healthcare workers in the COVID-19 and to implement intervention strategies aimed at increasing individual resilience alongside the establishment of external supportive work environments.

Fluorescence Enhanced Optical Resonator Constituted of Quantum Dots and Thin Film Resonant Cavity for High-Efficiency Reflective Color Filter.

Conventional color filters selectively absorb a part of the backlight while reflecting or transmitting other light, resulting in the problem of low efficiency and energy wasting. For this problem, a new concept of fluorescence enhanced optical resonator was proposed and verified in this paper. The new structure consists of structural color filter and light-conversion material. Specially, a thin film resonant cavity was designed, and InP/ZnSe/ZnS quantum dots were inserted inside the resonator. When illuminated by sunlight, the novel fluorescence enhanced optical resonator could not only reflect the specific light, but also convert absorbed energy into desired light, leading to the utilization efficiency improvement of solar energy. An all-dielectric red fluorescence enhanced optical resonator was fabricated, with peak equivalent reflectance up to 105%. Compared with a thin film resonator, the enhancement coefficient of the as-proposed structure is about 124%. The new optical structure can utilize solar source efficiently, showing application potential as the next generation of reflective color filters for display.

Survey on Public Psychological Intervention Demand and Influence Factors Analysis.

Major public health emergencies would have a negative influence on the psychology of the public, and an effective psychological intervention can help them to relieve some emotions, such as tension and panic. However, differences in individual environments affect people's psychological intervention demands and intervention mode choices. Therefore, it is of great theoretical and practical value to analyze and identify the key factors affecting these demands and choices. Based on a nationwide sample of 24,188 respondents from the "Internet Survey of Residents' Behavioral Changes and Psychological Conditions during the Epidemic," the different characteristics of public psychological intervention demands and choices under different factors are explored in this paper. The results demonstrate that: (1) the psychological status of Chinese people was relatively stable during the epidemic period, and there were 1016 respondents who had subjective demands for a psychological intervention, (2) age, gender, occupation type, residence, family size, risk perception, psychological status, education level, and fixed expenditure all significantly affect public psychological intervention demands, and (3) risk perception, psychological status, age, gender, and family size will impact the choice of psychological intervention methods. The above results can provide a decision-making basis for the construction of a psychological intervention system in psychological crisis management during the post-epidemic prevention and control period, as well as reference and suggestions for handling psychological stress of similar sudden crisis events in the future.

Sensitive and Easy-Read CRISPR Strip for COVID-19 Rapid Point-of-Care Testing.

Rapid and clinically sensitive detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) play an important role in the contact tracing and containment of the COVID-19 pandemic. A recently developed field-deployable clustered regularly interspaced short palindromic repeats (CRISPR) detection assay with lateral flow strips shows promise for point-of-care detection of SARS-CoV-2. However, the limit of detection of paper strip-based assays (10-100 copies/µL) is much lower than that of fluorescence-based detection methods. In this study, we developed an easy-readout and sensitive enhanced (ERASE) strip to visualize the results of CRISPR detection and improve the sensitivity to 1 copy/µL with an unambiguous easy-read result. Using 649 clinical samples from blind specimens collected from patients in China, we validated our ERASE assay for SARS-CoV-2 RNA detection with 90.67% positive predictive agreement and 99.21% negative predictive agreement. In conclusion, our study provided a customized CRISPR strip for use in a simple, rapid, ultrasensitive, and highly specific assay for SARS-CoV-2 detection. (Clinical Trial Registration number: 2020-008-01; [2020]IEC(ZD01); PJ-NBEY-2020-009-01; 2020#34).

Programmable RNA editing with compact CRISPR-Cas13 systems from uncultivated microbes.

Competitive coevolution between microbes and viruses has led to the diversification of CRISPR-Cas defense systems against infectious agents. By analyzing metagenomic terabase datasets, we identified two compact families (775 to 803 amino acids (aa)) of CRISPR-Cas ribonucleases from hypersaline samples, named Cas13X and Cas13Y. We engineered Cas13X.1 (775 aa) for RNA interference experiments in mammalian cell lines. We found Cas13X.1 could tolerate single-nucleotide mismatches in RNA recognition, facilitating prophylactic RNA virus inhibition. Moreover, a minimal RNA base editor, composed of engineered deaminase (385 aa) and truncated Cas13X.1 (445 aa), exhibited robust editing efficiency and high specificity to induce RNA base conversions. Our results suggest that there exist untapped bacterial defense systems in natural microbes that can function efficiently in mammalian cells, and thus potentially are useful for RNA-editing-based research.

Colorimetric isothermal nucleic acid detection of SARS-CoV-2 with dye combination.

RT-LAMP detection of SARS-CoV-2 has been demonstrated to be a valuable diagnostic method for the diagnosis of COVID-191,2, which can rapidly screen carriers of the virus to effectively control the spread of the SARS-CoV-2. Here, we present a combination of dyes for isothermal detection of SARS-CoV-2 as a commercial alternative, with expanded colorimetric spectrum. We compared them with commercial reagents and proved their suitability and sensitivity through clinical RNA samples. In addition, together with commercial single dye indicators, we believe the expanded color spectrum developed here as an indicator of rapid detection will promote the diagnosis of COVID-19.

Distributed Link Removal Strategy for Networked Meta-Population Epidemics and its Application to the Control of the COVID-19 Pandemic (preprint)

In this paper, we investigate the distributed link removal strategy for networked meta-population epidemics. In particular, a deterministic networked susceptible-infected-recovered (SIR) model is considered to describe the epidemic evolving process. In order to curb the spread of epidemics, we present the spectrum-based optimization problem involving the Perron-Frobenius eigenvalue of the matrix constructed by the network topology and transition rates. A modified distributed link removal strategy is developed such that it can be applied to the SIR model with heterogeneous transition rates on weighted digraphs. The proposed approach is implemented to control the COVID-19 pandemic by using the reported infected and recovered data in each state of Germany. The numerical experiment shows that the infected percentage can be significantly reduced by using the distributed link removal strategy.

A Universal Model for Prediction of COVID-19 Pandemic Based on Machine Learning (preprint)

Background: With the current worldwide spreading of the coronary virus (COVID-19) pandemic, accurately predicting the rate of spread of the virus has become an urgent need. Methods: In this article we propose a universal COVID-19 prediction model that is independent of country-specific factors in this paper. By analyzing the pandemic data in China, we combined the advantages of Gaussian function with that of chi-square distribution function, to render an innovative mathematical model named the H-Gaussian with five parameters to be learned, and solved the parameters by a gradient descent algorithm. Results: We trained the model with partial historical pandemic data to predict subsequent pandemic trends in several regions, and validated the predictions with real data. The H-Gaussian model was experimentally shown to correctly predict the pandemic trends, and the parameters had good interpretability. Conclusions: On this basis, the global trends of the pandemic are given based on the data currently available, as well as suggestions for subsequent prevention strategies.