Bouncing Dynamics of Drops' Successive Off-Center Impact.

Bouncing dynamics of a trailing drop off-center impacting a leading drop with varying time intervals and Weber numbers are investigated experimentally. Whether the trailing drop impacts during the spreading or receding process of the leading drop is determined by the time interval. For a short time interval of 0.15 ≤ Δt* ≤ 0.66, the trailing drop impacts during the spreading of the leading drop, and the drops completely coalesce and rebound; for a large time interval of 0.66 < Δt* ≤ 2.21, the trailing drop impacts during the receding process, and the drops partially coalesce and rebound. Whether the trailing drop directly impacts the surface or the liquid film of the leading drop is determined by the Weber number. The trailing drop impacts the surface directly at moderate Weber numbers of 16.22 ≤ We ≤ 45.42, while it impacts the liquid film at large Weber numbers of 45.42 < We ≤ 64.88. Intriguingly, when the trailing drop impacts the surface directly or the receding liquid film, the contact time increases linearly with the time interval but independent of the Weber number; when the trailing drop impacts the spreading liquid film, the contact time suddenly increases, showing that the force of the liquid film of the leading drop inhibits the receding of the trailing drop. Finally, a theoretical model of the contact time for the drops is established, which is suitable for different impact scenarios of the successive off-center impact. This study provides a quantitative relationship to calculate the contact time of drops successively impacting a superhydrophobic surface, facilitating the design of anti-icing surfaces.

Redox Relay-Induced C-S Radical Cross-Coupling Strategy: Application in Nontraditional Site-Selective Thiocyanation of Quinoxalinones.

Oxidative cross-coupling is a powerful strategy to form C-heteroatom bonds. However, oxidative cross-coupling for constructing C-S bond is still a challenge due to sulfur overoxidation and poisoning transition-metal catalysts. Now, electrochemical redox relay using sulfur radicals formed in situ from inorganic sulfur source offers a solution to this problem. Herein, electrochemical redox relay-induced C-S radical cross-coupling of quinoxalinones and ammonium thiocyanate with bromine anion as mediator is presented. The electrochemical redox relay comprised initially the formation of sulfur radical via indirect electrochemical oxidation, simultaneous electrochemical reduction of the imine bond, electro-oxidation-triggered radical coupling involving dearomatization-rearomatization, and the reformation of the imine bond through anodic oxidation. Applying this strategy, various quinoxalinones bearing multifarious electron-deficient/-rich substituents at different positions were well compatible with moderate to excellent yields and good steric hindrance compatibility under constant current conditions in an undivided cell without transition-metal catalysts and additional redox reagents. Synthetic applications of this methodology were demonstrated through gram-scale preparation and follow-up transformation. Notably, such a unique strategy may offer new opportunities for the development of new quinoxalinone-core leads.

Development and validation of a machine learning model to predict prognosis in liver failure patients treated with non-bioartificial liver support system.

Background and objectives: The prognosis of liver failure treated with non-bioartificial liver support systems is poor. Detecting its risk factors and developing relevant prognostic models still represent the top priority to lower its death risk. Methods: All 215 patients with liver failure treated with non-bioartificial liver support system were retrospectively analyzed. Potential prognostic factors were investigated, and the Nomogram and the Random Survival Forests (RSF) models were constructed, respectively. Notably, we evaluated the performance of models and calculated the risk scores to divide patients into low-risk and high-risk groups. Results: In the training set, multifactorial Cox regression analysis showed that etiology, hepatic encephalopathy, total bilirubin, serum alkaline phosphatase, platelets, and MELD score were independent factors of short-term prognosis. The RSF model (AUC: 0.863, 0.792) performed better in prediction than the Nomogram model (AUC: 0.816, 0.756) and MELD (AUC: 0.658, 0.700) in the training and validation groups. On top of that, patients in the low-risk group had a significantly better prognosis than those in the high-risk group. Conclusion: We constructed the RSF model with etiology, hepatic encephalopathy, total bilirubin, serum alkaline phosphatase, platelets, and MELD score, which showed better prognostic power than the Nomogram model and MELD score and could help physicians make optimal treatment decisions.

Constructing the Polymer Molecules to Regulate the Electrode/Electrolyte Interface to Enhance Lithium-Metal Battery Performance.

Lithium-ion batteries, with high energy density and long cycle life, have become the battery of choice for most vehicles and portable electronic devices; however, energy density, safety and cycle life require further improvements. Single-functional group electrolyte additives are very limited in practical applications, a ternary polymer bifunctional electrolyte additive copolymer (acrylonitrile-butyl hexafluoro methacrylate- poly (ethylene glycol) methacrylate- methyl ether) (PMANHF) was synthesized by free radical polymerization of acrylonitrile, 2, 2, 3, 4, 4, 4-hexafluorobutyl methacrylate and poly (ethylene glycol) methyl ether methacrylate. A series of characterizations show that in Li metal anodes, the preferential reduction of PMANHF is conducive to the formation of a uniform and stable solid electrolyte interphase layer, and Li deposition is uniform and dense. At the NCM811 cathode, a film composed of LiF- and Li3N-rich is formed at the cathode-electrolyte interface, mitigating the side reaction at the interface. At 1.0 mA cm-2, the Li/Li cell can be stabilized for 1000 cycles. In addition, the Li/NCM811 cell can stabilize 200 cycles with a cathode capacity of 153.7 mAh g-1, with the capacity retention of 89.93 %, at a negative/positive capacity ratio of 2.5. This study brings to light essential ideas for the fabrication of additives for lithium-metal batteries.

Development and validation of a diagnostic nomogram in pulmonary hypertension due to left heart disease.

BACKGROUND: Pulmonary hypertension (pH) due to left heart disease (pH-LHD) is the most common form of pH in clinical practice. OBJECTIVES: The purpose of the study is to develop a diagnostic nomogram predictive model combining conventional noninvasive examination and detection indicators. METHODS: Our study retrospectively included 361 patients with left heart disease (LHD) who underwent right heart catheterization between 2013 and 2020. All patients were randomly divided into a training cohort (253, 70 %) and a validation cohort (108, 30 %). pH was defined as resting mean pulmonary arterial pressure (mPAP) ≥25 mmHg measured by RHC examination. Data dimension reduction and feature selection were used by Lasso regression model. The nomogram was constructed based on multivariable logistic regression. RESULTS: A total of 175 patients with LHD were diagnosed with pH during their hospitalization, representing 48.5 % of the cohort. The mean age of the overall group was 55.6 years, with 76.7 % being male patients. Excessive resting heart rate, elevated New York Heart Association functional class, increased red blood cell distribution width, right ventricular end-diastolic diameter, and pulmonary artery systolic pressure measured by echocardiography were independently associated with the prevalence of pH-LHD. The inclusion of these 5 variables in the nomogram showed good discrimination (AUC = 0.866 [95 % CI, 0.820-0.911]) and optimal calibration (Hosmer-Lemeshow test, P = 0.791) for the validation cohort. CONCLUSIONS: The noninvasive nomogram of pH-LHD developed in this study has excellent diagnostic value and clinical applicability, and can more accurately evaluate the presence risk of pH in patients with LHD.

MIBPred: Ensemble Learning-Based Metal Ion-Binding Protein Classifier.

In biological organisms, metal ion-binding proteins participate in numerous metabolic activities and are closely associated with various diseases. To accurately predict whether a protein binds to metal ions and the type of metal ion-binding protein, this study proposed a classifier named MIBPred. The classifier incorporated advanced Word2Vec technology from the field of natural language processing to extract semantic features of the protein sequence language and combined them with position-specific score matrix (PSSM) features. Furthermore, an ensemble learning model was employed for the metal ion-binding protein classification task. In the model, we independently trained XGBoost, LightGBM, and CatBoost algorithms and integrated the output results through an SVM voting mechanism. This innovative combination has led to a significant breakthrough in the predictive performance of our model. As a result, we achieved accuracies of 95.13% and 85.19%, respectively, in predicting metal ion-binding proteins and their types. Our research not only confirms the effectiveness of Word2Vec technology in extracting semantic information from protein sequences but also highlights the outstanding performance of the MIBPred classifier in the problem of metal ion-binding protein types. This study provides a reliable tool and method for the in-depth exploration of the structure and function of metal ion-binding proteins.

Sestrin2 reduces ferroptosis via the Keap1/Nrf2 signaling pathway after intestinal ischemia-reperfusion.

Sestrins are metabolic regulators that respond to stress by reducing the levels of reactive oxygen species (ROS) and inhibiting the activity of target of rapamycin complex 1 (mTORC1). Previous research has demonstrated that Sestrin2 mitigates ischemia-reperfusion (IR) injury in the heart, liver, and kidneys. However, its specific role in intestinal ischemia-reperfusion (IIR) injury remains unclear. To elucidate the role of Sestrin2 in IIR injury, we conducted an experimental study using a C57BL/6J mouse model of IIR. We noticed an increase in the levels of Sestrin2 expression and indicators associated with ferroptosis. Our study revealed that manipulating Sestrin2 expression in Caco-2 cells through overexpression or knockdown resulted in a corresponding decrease or increase, respectively, in ferroptosis levels. Furthermore, our investigation revealed that Sestrin2 alleviated ferroptosis caused by IIR injury through the activation of the Keap1/Nrf2 signal pathway. This finding highlights the potential of Sestrin2 as a therapeutic target for alleviating IIR injury. These findings indicated that the modulation of Sestrin2 could be a promising strategy for managing prolonged IIR injury.

Discovery of the first ataxia telangiectasia and Rad3-related (ATR) degraders for cancer treatment.

The first examples of ataxia telangiectasia and Rad3-related (ATR) PROTACs were designed and synthesized. Among them, the most potent degrader, ZS-7, demonstrated selective and effective ATR degradation in ATM-deficient LoVo cells, with a DC50 value of 0.53 µM. Proteasome-mediated ATR degradation by ZS-7 lasted approximately 12 h after washout in the LoVo cell lines. Notably, ZS-7 demonstrated reasonable PK profiles and, as a single agent or in combination with cisplatin, showed improved antitumor activity and safety profiles compared with the parent inhibitor AZD6738 in a xenograft mouse model of LoVo human colorectal cancer cells upon intraperitoneal (i.p.) administration.

Correlation of ventricle epicardial fat volume and triglyceride-glucose index in patients with chronic heart failure.

To explore the association of ventricle epicardial fat volume (EFV) calculated by cardiac magnetic resonance (CMR) and the insulin resistance indicator of triglyceride-glucose (TyG) index in patients with chronic HF (CHF), this retrospective cohort study included adult CHF patients with confirmed diagnosis of heart failure from January 2018 to December 2020. All patients underwent 3.0T CMR, and EFV were measured under short-axis cine. Spearman correlation, multivariate linear regression, and restricted cubic spline (RCS) regression were used to analyze their association. There were 516 patients with CHF, of whom 69.8% were male. Median EFV was 57.14mL and mean TyG index was 8.48. Spearman correlation analysis showed that TyG index was significantly correlated with the EFV in CHF patients (r = 0.247, P < 0.001). Further analysis showed that TyG index levels were significantly associated with EFV as both continuous variables (Unstandardized ß = 6.556, P < 0.001) and across the increasing quartiles (ß = 7.50, 95% CI [1.41, 13.59], P < 0.05). RCS demonstrated there were a positive trend and linear association between EFV and TyG index in CHF patients (P for nonliearity = 0.941). In patients with CHF, the TyG index was positively and linearly associated with the EFV, which supports the metabolic roles of epicardial adipose tissue regarding insulin resistance.

Mangiferin alleviates diabetic pulmonary fibrosis in mice via inhibiting endothelial-mesenchymal transition through AMPK/FoxO3/SIRT3 axis.

Diabetes mellitus results in numerous complications. Diabetic pulmonary fibrosis (DPF), a late pulmonary complication of diabetes, has not attracted as much attention as diabetic nephropathy and cardiomyopathy. Mangiferin (MF) is a natural small molecular compound that exhibits a variety of pharmacological effects including anti-inflammatory, anti-cancer, anti-diabetes, and anti-fibrosis effects. In this study, we investigated whether long-term diabetes shock induces DPF, and explored whether MF had a protective effect against DPF. We first examined the lung tissues and sections of 20 diabetic patients obtained from discarded lung surgical resection specimens and found that pulmonary fibrosis mainly accumulated around the pulmonary vessels, accompanied by significantly enhanced endothelial-mesenchymal transition (EndMT). We established a mouse model of DPF by STZ injections. Ten days after the final STZ injection, the mice were administered MF (20, 60 mg/kg, i.g.) every 3 days for 4 weeks, and kept feeding until 16 weeks and euthanized. We showed that pulmonary fibrotic lesions were developed in the diabetic mice, which began around the pulmonary vessels, while MF administration did not affect long-term blood glucose levels, but dose-dependently alleviated diabetes-induced pulmonary fibrosis. In human umbilical vein endothelial cells (HUVECs), exposure to high glucose (33.3 mM) induced EndMT, which was dose-dependently inhibited by treatment with MF (10, 50 µM). Furthermore, MF treatment promoted SIRT3 expression in high glucose-exposed HUVECs by directly binding to AMPK to enhance the activity of FoxO3, which finally reversed diabetes-induced EndMT. We conclude that MF attenuates DPF by inhibiting EndMT through the AMPK/FoxO3/SIRT3 axis. MF could be a potential candidate for the early prevention and treatment of DPF.

Impact of frailty on outcomes of elderly patients undergoing percutaneous coronary intervention: A systematic review and meta-analysis.

BACKGROUND: Frailty is a common condition in elderly patients who receive percutaneous coronary intervention (PCI). However, how frailty affects clinical outcomes in this group is unclear. AIM: To assess the link between frailty and the outcomes, such as in-hospital complications, post-procedural complications, and mortality, in elderly patients post-PCI. METHODS: The PubMed/MEDLINE, EMBASE, Cochrane Library, and Web of Science databases were screened for publications up to August 2023. The primary outcomes assessed were in-hospital and all-cause mortality, major adverse cardiovascular events (MACEs), and major bleeding. The Newcastle-Ottawa Scale was used for quality assessment. RESULTS: Twenty-one studies with 739693 elderly patients undergoing PCI were included. Frailty was consistently associated with adverse outcomes. Frail patients had significantly higher risks of in-hospital mortality [risk ratio: 3.45, 95% confidence interval (95%CI): 1.90-6.25], all-cause mortality [hazard ratio (HR): 2.08, 95%CI: 1.78-2.43], MACEs (HR: 2.92, 95%CI: 1.85-4.60), and major bleeding (HR: 4.60, 95%CI: 2.89-7.32) compared to non-frail patients. CONCLUSION: Frailty is a pivotal determinant in the prediction of risk of mortality, development of MACEs, and major bleeding in elderly individuals undergoing percutaneous coronary intervention.

Increased serum visfatin level is associated with fat deposition of the lumbar spine in ankylosing spondylitis patients.

Objectives: To assess the serum visfatin levels in patients with ankylosing spondylitis (AS), as well as its correlation with fat deposition of the lumbar spine. Methods: Serum visfatin levels were detected by enzyme-linked immunosorbent assay (ELISA) in 50 AS patients and 75 sex-and age-matched healthy controls. The clinical and laboratory indexes of AS patients were recorded, and the lumbar spine magnetic resonance scan was performed to evaluate the lumbar spine fat deposition in AS patients. The level of serum visfatin and its correlation with lumbar fat deposition were analyzed, and the risk factors of AS lumbar MRI fat deposition were evaluated by Logistic regression. Results: Serum visfatin levels in AS patients were elevated compared with that in healthy controls (p < 0.001), and were more significant in patients with fat deposition and syndesmophyte formation (p = 0.017 and p = 0.014, respectively). Serum visfatin levels were positively correlated with CRP, BASDAI, mSASSS and fat deposition (all p < 0.05). Age (OR = 1.085, 95% CI: 1.005-1.173, p = 0.038), disease duration (OR = 1.267, 95% CI: 1.017-1.578, p = 0.035), and visfatin (OR = 1.846, 95% CI: 1.004-3.393, p = 0.048) were risk factors for fat deposition in AS patients. Conclusions: The level of serum visfatin in AS patients is significantly increased, which is associated with fat deposition on lumbar MRI. Elevated visfatin level is an independent risk factor for AS lumbar fat deposition.

Targeting Cartilage miR-195/497 Cluster for Osteoarthritis Treatment Regulates the Circadian Clock.

INTRODUCTION: Osteoarthritis (OA) is the most prevalent and debilitating joint disease without an effective therapeutic option. Multiple risk factors for OA have been identified, including abnormal chondrocyte miRNA secretion and circadian rhythms disruption, both of which have been found to cause progressive damage and loss of articular cartilage. Environmental disruption of circadian rhythms in mice predisposes animals to cartilage injury and OA. METHODS: The role of miR-195/497 cluster during OA progression was verified by mouse OA model with intra-articular injection of Agomir and Antagomir. We performed micro-CT analysis, Osteoarthritis Research Society International scores, and histological analysis in mouse knee joints. RNA sequencing was performed on the mouse cartilage cell line to explore the molecular mechanism of the miR-195/497 cluster and proteins in signaling pathway were evaluated using Western blot. Senescence-associated phenotypes were detected by Western blot, senescence ß-galactosidase staining, and immunofluorescence. RESULTS: This study demonstrated that miR-195/497-5p expression is disrupted in OA with senescent chondrocytes. In addition, miR-195/497-5p influenced the circadian rhythm of mice chondrocytes by modulating the expression of the Per2 protein, resulting in the gradual degradation of articular cartilage. We found that the miR-195/497 cluster targets DUSP3 expression. The deletion of the miR-195/497 cluster increased the level of DUSP3 expression and decreased the levels of phosphorylated ERK 1/2 and CREB. Per2 transcription is upregulated by stimulating CREB and ERK 1/2 phosphorylation. CONCLUSION: Our findings identify a regulatory mechanism connecting chondrocyte miR-195/497-5p to cartilage maintenance and repair and imply that circadian rhythm disturbances affected by miR-195/497-5p are risk factors for age-related joint diseases such as OA.

Ethnomedicinal plants in Champadevi rural municipality, Okhaldhunga district, Nepal.

BACKGROUND: Okhaldhunga is a hilly district with fragile socioeconomic conditions, limited access to health care, social stigma, and poor resource management, where most people rely on medicinal plants for primary health care. The use of medicinal plants for primary health care varies with socioeconomic attributes. Following the intra-cultural analysis, we documented and tested the hypothesis that use of medicinal plants in Champadevi, Okhaldhunga, Nepal, depends on socioeconomic variables. METHODS: We interviewed 224 respondents, 53.12% female and 46.88% male, including 31 Brahmin, 157 Chhetri, 13 Dalit, and 23 Janajati, and conducted three focused group discussions and seven key informant interviews to record the ethnomedicinal plants used in Champadevi rural municipality, Okhaldhunga District. The relative frequency of citation (RFC) was computed to know the importance of the species. A generalized linear model (GLM) was used to see the relationship between medicinal plants reported with the sociocultural variables, which include age, gender, occupation, education, ethnicity, and religion. RESULTS: We documented 149 medicinal plants, including 69 herbs, 22 shrubs, nine climbers, 48 trees, and one parasitic plant, belonging to 68 families and 130 genera, and used to treat 48 distinct diseases and ailments. Plant parts, leaf, and digestive disorders were frequently treated during healing. Curcuma angustifolia was the most cited species with RFC 0.9554. The respondents' knowledge of medicinal plant use varied significantly with age (p = 0.0001) and occupation (p = 0.003). Changes in land use, population decline of medicinal plant species, and unsustainable harvesting practices constituted the local threats to medicinal plants and associated knowledge. Elders died without passing on their knowledge to the younger generations during sociocultural transformation, and youth disinterest coupled with the free availability of allopathic medicine led to knowledge erosion. CONCLUSIONS: The use of medicinal plants in Champadevi, Okhaldhunga, was significantly depended on two socioeconomic variables age and occupation. Ethnomedicinal plants are essential in the primary healthcare system in Nepal; however, their availability and practices are declining. Thus, plans regulating land use change and human migration, acknowledging traditional healthcare practices, and raising awareness of the significance of traditional medical practices as complementary healthcare practices should be strengthened.

Hydroxycitric Acid Alleviated Lung Ischemia-Reperfusion Injury by Inhibiting Oxidative Stress and Ferroptosis through the Hif-1α Pathway.

Lung ischemia-reperfusion injury (LIRI) is a prevalent occurrence in various pulmonary diseases and surgical procedures, including lung resections and transplantation. LIRI can result in systemic hypoxemia and multi-organ failure. Hydroxycitric acid (HCA), the primary acid present in the peel of Garcinia cambogia, exhibits anti-inflammatory, antioxidant, and anticancer properties. However, the effects of HCA on LIRI remain unknown. To investigate the impact of HCA on LIRI in mice, the mice were randomly divided into four groups: the control group, the I/R model group, and the I/R + low- or high-dose HCA groups. Human umbilical vein endothelial cells (HUVECs) were subjected to hypoxia for 12 h followed by reoxygenation for 6 h to simulate in vitro LIRI. The results demonstrated that administration of HCA effectively attenuated lung injury, inflammation, and edema induced by ischemia reperfusion. Moreover, HCA treatment significantly reduced malondialdehyde (MDA) and reactive oxygen species (ROS) levels while decreasing iron content and increasing superoxide dismutase (SOD) levels after ischemia-reperfusion insult. Mechanistically, HCA administration significantly inhibited Hif-1α and HO-1 upregulation both in vivo and in vitro. We found that HCA could also alleviate endothelial barrier damage in H/R-induced HUVECs in a concentration-dependent manner. In addition, overexpression of Hif-1α counteracted HCA-mediated inhibition of H/R-induced endothelial cell ferroptosis. In summary, these results indicate that HCA alleviated LIRI by inhibiting oxidative stress and ferroptosis through the Hif-1α pathway.

Improvement of the conjugation transfer of N. gerenzanensis based on the synergistic effect of quorum sensing and antibiotic interference.

Nonomuraea gerenzanensis (N. gerenzanensis) is known for its ability to biosynthesize A40926, the precursor of the glycopeptide antibiotic (GPA) Dalbavancin. However, challenges and uncertainties related to the genetic manipulation of the rare actinomycetes remain. In order to improve the conjugation transfer of N. gerenzanensis, the crucial factors affecting conjugal transfer were evaluated, including agar medium, mycelial state, donor-recipient ratio, magnesium ion concentration, and antibiotic coverage time firstly. Additionally, γ-butyrolactone (GBL) for quorum sensing (QS) and antibiotics targeting bacterial walls were applied to evaluate their effects on conjugation transfer. As a result, the optimal conditions of 5%TSB of liquid medium, 24 h of the period time, V0.1 of agar medium, 30 mM of magnesium ion, the ratio 10:1 of donor-to-recipient, and 27 h of the overlaying time of antibiotic were determined. Furthermore, the results showed that autoinducer GBL and GPA teicoplanin had a synergetic effect on the conjugation transfer of N. gerenzanensis at a working concentration of 60 µM and 0.5 µg mL-1, respectively. The highest conjugation efficiency could reach about 1.3 depending on the optimal process conditions and the interference of QS and antibiotics.

Carpets with visual cues can improve gait in Parkinson's disease patients: may be independent of executive function.

BACKGROUND: Gait impairment is common in Parkinson's disease (PD) patients, which greatly reduces their quality of life. Executive dysfunction is associated with gait impairment. Compensatory strategies, including visual cues, have been shown to be effective in improving PD gait. In this study, we aimed to understand whether carpets with visual cues could improve PD gait, and how the improvement varies across patients with different executive function state. METHODS: We designed carpets with chessboard and stripe cues. A total of 65 Chinese PD patients were recruited. Movement Disorder Society Unified Parkinson's Disease Rating Scale, L-dopa equivalent daily dosage, Hoehn & Yahr stage, Frontal Assessment Battery, Mini Mental State Examination Scale, Hamilton Anxiety Scale, and Hamilton Depression Scale were evaluated. Gait parameters including stride length, gait speed and fall risk were recorded by a wearable electronic device. RESULTS: The stride length and gait speed were significantly improved and the fall risk was significantly mitigated when PD patients walked on carpets with chessboard and stripe patterns. Further analysis showed the amelioration of gait parameters was independent of executive dysfunction. CONCLUSIONS: Our study demonstrates that carpets with visual cues can improve the gait of PD patients even in those with mild executive dysfunction.

Divergent and Selective Light Alkene Cross-Coupling.

Light olefins are abundantly manufactured in the petroleum industry and thus represent ideal starting materials for modern chemical synthesis. Selective and divergent transformations of feedstock light olefins to value-added chemicals are highly sought-after but remain challenging. Herein we report an exceptionally regioselective carbonickelation of light alkenes followed by in situ trapping with three types of nucleophiles, namely a reductant, base, or Grignard reagent. This protocol enables efficient 1,2-hydrofunctionalization, dicarbofunctionalization, and branched-selective Heck-type cross-coupling of light alkenes with aryl and alkenyl reagents to streamline access to diverse alkyl arenes and complex alkenes. Harnessing bulky N-heterocyclic carbene ligands with acenaphthyl backbones for nickel catalysts is crucial to attain high reactivity and selectivity. This strategy provides a rare, modular, and divergent platform for upgrading feedstock alkenes and is expected to find broad applications in medicinal chemistry and industrial processes.

Spatial-temporal V-Net for automatic segmentation and quantification of right ventricle on gated myocardial perfusion SPECT images.

BACKGROUND: Functional assessment of right ventricle (RV) using gated myocardial perfusion single-photon emission computed tomography (MPS) heavily relies on the precise extraction of right ventricular contours. PURPOSE: In this paper, we present a new deep-learning-based model integrating both the spatial and temporal features in gated MPS images to perform the segmentation of the RV epicardium and endocardium. METHODS: By integrating the spatial features from each cardiac frame of the gated MPS and the temporal features from the sequential cardiac frames of the gated MPS, we developed a Spatial-Temporal V-Net (ST-VNet) for automatic extraction of RV endocardial and epicardial contours. In the ST-VNet, a V-Net is employed to hierarchically extract spatial features, and convolutional long-term short-term memory (ConvLSTM) units are added to the skip-connection pathway to extract the temporal features. The input of the ST-VNet is ECG-gated sequential frames of the MPS images and the output is the probability map of the epicardial or endocardial masks. A Dice similarity coefficient (DSC) loss which penalizes the discrepancy between the model prediction and the manual annotation was adopted to optimize the segmentation model. RESULTS: Our segmentation model was trained and validated on a retrospective dataset with 45 subjects, and the cardiac cycle of each subject was divided into eight gates. The proposed ST-VNet achieved a DSC of 0.8914 and 0.8157 for the RV epicardium and endocardium segmentation, respectively. The mean absolute error, the mean squared error, and the Pearson correlation coefficient of the RV ejection fraction (RVEF) between the manual annotation and the model prediction were 0.0609, 0.0830, and 0.6985. CONCLUSION: Our proposed ST-VNet is an effective model for RV segmentation. It has great promise for clinical use in RV functional assessment.

Contamination dynamics of personal protective equipment (PPE) by SARS-CoV-2 RNA in a makeshift hospital with COVID-19 positive occupants.

Background: Personal protective equipment (PPE) helps protect healthcare workers (HCWs) from infection and prevents cross-contamination. Knowledge of the contamination dynamics of PPE during the management of COVID-19 patients in a makeshift hospital is limited. Aim: To describe the rate of SARS-CoV-2 contamination in PPE and to assess the change of contamination at different time points. Methods: HCWs were followed up for up to 4 hours with hourly collection of swab samples from PPE surfaces in a makeshift COVID-19 hospital setting. Swabs were tested using quantitative reverse transcription polymerase chain reaction (RT-qPCR) for SARS-CoV-2 RNA. Results: SARS-CoV-2 was detected on 50.9% of the 1620 swabbed samples from 9 different sites of full-body PPE worn by HCWs. The proportion of sites contaminated with SARS-CoV-2 RNA varied from 10.6% to 95.6%. Viral RNA was most frequently detected from the sole of the outer foot cover (95.6%) and least frequently on the face shield (10.6%). The median Ct values among positive samples were 34.20 (IQR, 32.61-35.22) and 34.05 (IQR, 32.20-35.39) for ORF1ab and N genes, respectively. The highest rate of contamination with SARS-CoV-2 RNA for the PPE swab samples was found after 3 hours of use. The positive rate of outer surface of HEPA filters from air supply device was 82.1% during the full capacity period of the makeshift hospital. Conclusion: A higher rate of contamination was identified at 3 hours after the entrance to the COVID-19 patient care area. Virus-containing aerosols were trapped in the HEPA filter of air supply equipment, representing a potential protective factor against infection to HCWs.