μ4-Sulfido-bis­{(μ-2-furyl­methane­thiol­ato)bis­[tricarbonyl­iron](Fe—Fe)}

The title compound, [Fe4(C5H5OS)2S(CO)12], was prepared by the direct reaction of Fe3(CO)12 and 2-furyl­methane­thiol in tetra­hydro­furan. Desulfurization took place readily to form an Fe4S3 cluster. The mol­ecule consists of two similar [(μ-2-C4H3O—CH2S)Fe2(CO)6] moieties joined to a spiro-type four-coordinate μ4-S atom such that this bridging sulfur is tetra­hedrally coordinated to the four Fe atoms. In each diiron subcluster core, the 2-furyl­methane­thiol­ate ligand bridges the two Fe atoms

Mean square stabilization of discrete-time switching Markov jump linear systems

This paper consider a special class of hybrid system called switching Markov jump linear system. The system transition is governed by two rules. One is Markov chain and the other is a deterministic rule. Furthermore, the transition probability of the Markov chain is not only piecewise but also orchestrated by a deterministic switching rule. In this paper the mean square stability of the systems is studied when the deterministic switching is subject to two different dwell time conditions: having a lower bound and having both lower and high bounds. The main contributions of this paper are two relevant stability theorems for the systems under study. A numerical example is provided to demonstrate the theoretical results

Establishment of a nomogram model for acute chest pain triage in the chest pain center

BackgroundAcute myocardial infarction (AMI) is the leading life-threatening disease in the emergency department (ED), so rapid chest pain triage is important. This study aimed to establish a clinical prediction model for the risk stratification of acute chest pain patients based on the Point-of-care (POC) cardiac troponin (cTn) level and other clinical variables.MethodsWe conducted a post-hoc analysis of the database from 6,019 consecutive patients (excluding prehospital-diagnosed non-cardiac chest pain patients) attending a local chest pain center (CPC) in China between October 2016 and January 2019. The plasma concentration of cardiac troponin I (cTnI) was measured using a POC cTnI (Cardio Triage, Alere) assay. All the eligible patients were randomly divided into training and validation cohorts by a 7:3 ratio. We performed multivariable logistic regression to select variables and build a nomogram based on the significant predictive factors. We evaluated the model's generalization ability of diagnostic accuracy in the validation cohort.ResultsWe analyzed data from 5,397 patients that were included in this research. The median turnaround time (TAT) of POC cTnI was 16 min. The model was constructed with 6 variables: ECG ischemia, POC cTnI level, hypotension, chest pain symptom, Killip class, and sex. The area under the ROC curve (AUC) in the training and validation cohorts was 0.924 and 0.894, respectively. The diagnostic performance was superior to the GRACE score (AUC: 0.737).ConclusionA practical predictive model was created and could be used for rapid and effective triage of acute chest pain patients in the CPC

Thermal stability and inactivation of hepatitis C virus grown in cell culture

<p>Abstract</p> <p>Background</p> <p>Hepatitis C virus (HCV) is a blood-borne flavivirus that infects many millions of people worldwide. Relatively little is known, however, concerning the stability of HCV and reliable procedures for inactivating this virus.</p> <p>Methods</p> <p>In the current study, the thermostability of cell culture-derived HCV (HCVcc, JFH-1 strain) under different environmental temperatures (37°C, room temperature, and 4°C) and the ability of heat, UVC light irradiation, and aldehyde and detergent treatments to inactivate HCVcc were evaluated. The infectious titers of treated viral samples were determined by focus-forming unit (FFU) assay using an indirect immunofluorescence assay for HCV NS3 in hepatoma Huh7-25-CD81 cells highly permissive for HCVcc infection. MTT cytotoxicity assay was performed to determine the concentrations of aldehydes or detergents at which they were no longer cytotoxic.</p> <p>Results</p> <p>HCVcc in culture medium was found to survive 37°C and room temperature (RT, 25 ± 2°C) for 2 and 16 days, respectively, while the virus was relatively stable at 4°C without drastic loss of infectivity for at least 6 weeks. HCVcc in culture medium was sensitive to heat and could be inactivated in 8 and 4 min when incubated at 60°C and 65°C, respectively. However, at 56°C, 40 min were required to eliminate HCVcc infectivity. Addition of normal human serum to HCVcc did not significantly alter viral stability at RT or its susceptibility to heat. UVC light irradiation (wavelength = 253.7 nm) with an intensity of 450 μW/cm²efficiently inactivated HCVcc within 2 min. Exposures to formaldehyde, glutaraldehyde, ionic or nonionic detergents all destroyed HCVcc infectivity effectively, regardless of whether the treatments were conducted in the presence of cell culture medium or human serum.</p> <p>Conclusions</p> <p>The results provide quantitative evidence for the potential use of a variety of approaches for inactivating HCV. The ability of HCVcc to survive ambient temperatures warrants precautions in handling and disposing of objects and materials that may have been contaminated with HCV.</p

A Survey on Off-chain Networks: Frameworks, Technologies, Solutions and Challenges

Blockchain has received increasing attention in academia and industry. However, the increasing transaction volumes and limited on-chain storage underscore scalability as a key challenge hindering the widespread adoption of blockchain. Fortunately, off-chain networks that enable transactions outside the blockchain show promising potential to mitigate the scalability challenge. Off-chain solutions that address blockchain scalability hurdles, such as payment channel networks, facilitate secure and fast off-chain transactions, thus relieving the main chain's strain. In this article, we provide a comprehensive review of key technologies, solutions, and challenges of off-chain networks. First, we introduce the background of off-chain networks encompassing design motivation, framework, overview, and application scenarios. We then review the key issues and technologies associated with off-chain networks. Subsequently, we summarize the mainstream solutions for the corresponding key issues. Finally, we discuss some research challenges and open issues in this area.Comment: 30 pages, 5 figure

Structural and functional analysis of amphioxus HIFα reveals ancient features of the HIFα family

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154538/1/fsb2028004032.pd

Application of problem based learning steered by constructivism in Ophthalmologic teaching

AIM: To investigate the application of problem based learning(PBL)steered by constructivism. <p>METHODS: The 120 students were appointed as the routine teaching group and the PBL steered by constructivism group separately, who were coming from the department of clinical medicine and clinical pharmacy in grade 94, China Medical University. They were divided into PBL steered by constructivism group(60 students)and the routine teaching group(60 students). The students' feedbacks and teaching effects were compared by the questionnaire after teaching. <p>RESULTS: The feedback of the students in the PBL steered by constructivism group were significant better than that in the routine teaching group, including interest, referring data, self-study, thought process, obtaining and spreading knowledge, computer utilization, studying independently, concerted struggling, appreciating and magnanimous ability, discussion and communication(<i>P</i><0.05).<p>CONCLUSION: Application of problem based learning steered by constructivism interests the students in Ophthalmologic teaching and is helpful in their self-study, which is benefit to elevate the teaching level and train the qualified scientists