88 research outputs found
Z-source matrix rectifier
This paper presents a novel Z-source matrix rectifier(ZSMR). To overcome the inherent disadvantage that the voltage transfer ratio for traditional matrix rectifier cannot be more than 0.866, a Z-source network has been combined with the matrix rectifier. The proposed rectifier realizes a voltage-boost function and the Z-source network also serves as power storage and guarantees double filtration grade at the output of the rectifier. The open-circuit zero state is required to obtain the voltage-boost function and ensure the output angle of the current vector to be invariant to obtain the expected power factor. In addition, to widely extend the voltage transfer ratio of the proposed rectifier, this paper presents the switched-inductor matrix rectifier(SL-ZSMR) and tapped-inductor matrix rectifier(TL-ZSMR). The corresponding circuit topologies, control strategies and operating principles are introduced. Both simulation and experiment results are shown to verify the theoretical analysis
Treatment of Esophagogastric Anastomotic Leak with Perianastomotic Drain
IntroductionThe most efficient treatment of such anastomotic leaks after esophagectomy remains controversial. Our objective was to evaluate the effectiveness of perianastomotic drains in anastomotic leaks.MethodsFive patients with intrathoracic anastomotic leaks had placement of perianastomotic drains through remanet esophagus and fitula into infected area. The other conservative methods of treatment were also chosen simultaneously.ResultsThe perianastomotic drains were placed successfully in all five patients. None of the patients underwent rethoracotomy. They were all cured. The median period to clinical healing was 33 days. The median hospital stay after the perianastomotic drainage procedure was 37 days.ConclusionThis procedure proved to be safe and effective in the treatment of esophagogastric anastomotic leak with perianastomotic drain through fistula
Comparative Metabolomics Revealed Metabolite Differences in Bamboo Shoots (Chimonobambusa tumidissinoda Hsueh & T. P. Yi ex Ohrnberger) at Different Growth Stages
In order to explore the dynamic changes and stage specificity of metabolites in bamboo shoots during its growth, widely targeted metabolomics based on ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was used to analyze fresh bamboo shoots harvested at heights of 10 and 25 cm. The results showed that a total of 875 metabolites belonging to 13 categories were identified from bamboo shoots, including sugars, alcohols and flavonoids, whose relative contents significantly increased in 25 cm-high bamboo shoots. Moreover, the results of multivariate statistical analyses showed that the metabolites in bamboo shoots had an obvious stage specificity. Totally 283 significantly differential metabolites were identified between the two growth stages, of which 102 metabolites were annotated to 82 metabolic pathways. The contents of 20 major nutrients did not significantly differ between the two growth stages; however, the contents of metabolites related to taste, flavor and bioactive function were higher, while the content of bitter compounds was lower in the 25 cm-high bamboo shoots. Therefore, compared with the 10 cm-high bamboo shoots, the 25 cm-high bamboo shoots have a higher comprehensive economic value and are more suitable for harvesting. The results of this study can provide a theoretical reference for the comprehensive development and sustainable utilization of Chimonobambusa tumidissinoda
Corrigendum: The prospective outcome of the Monkeypox outbreak in 2022 and characterization of monkeypox disease immunobiology
The prospective outcome of the monkeypox outbreak in 2022 and characterization of monkeypox disease immunobiology
A new threat to global health re-emerged with monkeypox’s advent in early 2022. As of November 10, 2022, nearly 80,000 confirmed cases had been reported worldwide, with most of them coming from places where the disease is not common. There were 53 fatalities, with 40 occurring in areas that had never before recorded monkeypox and the remaining 13 appearing in the regions that had previously reported the disease. Preliminary genetic data suggest that the 2022 monkeypox virus is part of the West African clade; the virus can be transmitted from person to person through direct interaction with lesions during sexual activity. It is still unknown if monkeypox can be transmitted via sexual contact or, more particularly, through infected body fluids. This most recent epidemic’s reservoir host, or principal carrier, is still a mystery. Rodents found in Africa can be the possible intermediate host. Instead, the CDC has confirmed that there are currently no particular treatments for monkeypox virus infection in 2022; however, antivirals already in the market that are successful against smallpox may mitigate the spread of monkeypox. To protect against the disease, the JYNNEOS (Imvamune or Imvanex) smallpox vaccine can be given. The spread of monkeypox can be slowed through measures such as post-exposure immunization, contact tracing, and improved case diagnosis and isolation. Final Thoughts: The latest monkeypox epidemic is a new hazard during the COVID-19 epidemic. The prevailing condition of the monkeypox epidemic along with coinfection with COVID-19 could pose a serious condition for clinicians that could lead to the global epidemic community in the form of coinfection
Evaluation of an identification method for the SARS-CoV-2 Delta variant based on the amplification-refractory mutation system
The Delta variant of SARS-CoV-2 dominated the COVID-19 pandemic due to its high viral replication capacity and immune evasion, causing massive outbreaks of cases, hospitalizations, and deaths. Currently, variant identification is performed mainly by sequencing. However, the high requirements for equipment and operators as well as its high cost have limited its application in underdeveloped regions. To achieve an economical and rapid method of variant identification suitable for undeveloped areas, we applied an amplification-refractory mutation system (ARMS) based on PCR for the detection of novel coronavirus variants. The results showed that this method could be finished in 90 min and detect as few as 500 copies/mL and not react with SARS-Coronavirus, influenza A H1N1(2009), and other cross-pathogens or be influenced by fresh human blood, α- interferon, and other interfering substances. In a set of double-blind trials, tests of 262 samples obtained from patients confirmed with Delta variant infection revealed that our method was able to accurately identify the Delta variant with high sensitivity and specificity. In conclusion, the ARMS-PCR method applied in Delta variant identification is rapid, sensitive, specific, economical, and suitable for undeveloped areas. In our future study, ARMS-PCR will be further applied in the identification of other variants, such as Omicron
Optimization of Stakeholder Relation Network of the Qingdao Elderly Livable Community Construction Project
Due to the population ageing, building an elderly livable community has become an urgent task of social welfare development. This Public-Private Partnership construction project faces a variety of pressures from its complex stakeholders. Based on the Qingdao elderly livable community construction project, this paper builds up interpretations about its relationship governance by conducting stakeholder analysis. The paper aims to explore the relationship governance mechanism of multiple connections between related stakeholders. On the basis of complex network theory, this paper establishes a stakeholder relationship network model and describes different modes of different stakeholder relationship in the Qingdao construction project. The paper analyzes the optimal decision-making behavior and interaction of different stakeholders, constructs the objective functions of stakeholder relationship network, applies centrality measure and dominant-set clustering to analyze the optimal conditions of the whole network, and finally carries out simulation calculation. The results show that it is feasible and effective to apply network analysis method to the study of stakeholder relationship in Public-Private Partnership construction projects
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