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The short-circuit ratio is an important indicator to measure the risk of subsynchronous oscillation induced by the access of the wind farm to alternating current system. The current short-circuit ratio does not have a clear definition and a detailed calculation formula for the short-circuit ratio of wind-fire bundled and grid-connected operation has not been given. Therefore, for an actual planning scenario of dual offshore wind power clusters and thermal power bundling system, a short-circuit ratio calculation method was proposed to reveal the influence of the interaction of dual wind power clusters on subsynchronous oscillation. The research results show that the wind-fire bundling and grid connection can improve the short-circuit ratio of the system. Compared with pure wind power, the speed of reducing the short-circuit ratio is slowed down and the stability of subsynchronous oscillation is improved. From the analysis of the formula, the three influencing factors of the short-circuit ratio of wind-fire bundling are system impedance, fan ratio, and wind-fire ratio. The analysis results show that the fan ratio has the least impact on the subsynchronous oscillation, and the wind-fire ratio has the greatest impact. Finally, a model of an actual planning offshore wind power cluster and thermal power bundling system was built in PSCAD/EMTDC to verify the rationality of the above research results.

Aimed at the fact that the chirplet rate parameter of the chirplet transform (CT) cannot match the instantaneous frequency of the signal completely, and that the anti-noise performance of the algorithm is poor, this paper proposes a high-quality local maximum synchrosqueezing chirplet transform (LMSCT) algorithm to improve the deviation of energy diffusion amplitude in CT time-frequency (TF)distribution. The main idea of this algorithm is to reallocate CT frequency points by local maximum synchrosqueezing operation. The experiment results show that the LMSCT algorithm has a higher TF concentration and a strong ability to suppress the interference of noise. The method can maintain a better resolution of TF representation at a low signal-to-noise ratio. In the application analysis of IPIX processing radar signals, the LMSCT algorithm can clearly describe the TF joint distribution characteristic of target signal and determine the distance unit of target, which provides the judgement basis for small target detection of IPIX radar signal in the background of sea clutter.

The experiment took the broccoli (Brassica oleracea var. italica) as the research object, 1-methylcyclopropene (1-MCP), mustard essential oil (MEO) and 1-MCP combined MEO (1-MCP+MEO) were used to treat fresh green broccoli. The effects of physiological and biochemical indexes such as sensory quality, relative conductivity, chlorophyll, vitamin C and malondialdehyde (MDA) content on the quality of broccoli were investigated during storage. The result showed that with the increase of storage time, all groups of preservative treatments could effectively maintain the quality of broccoli during storage, among which 1-MCP+MEO treatment had the best storage effect on broccoli, effectively maintained the appearance of broccoli, avoided yellows and mildew, and slowed down the chlorophyll content and vitamin C degradation rate and made the chlorophyll content of broccoli always higher than that of other treatment groups. 1-MCP+MEO inhibited the increase of relative conductivity and MDA content in broccoli. On the 28th day of storage, the relative conductivity and MDA of the combined treatment group were 14.94% and 9.1 µmol/g, respectively, which were 43.1% and 27.6% lower than that of the control group respectively, and there was a significant difference (P<0.05), so that the cell integrity of the broccoli was maintained and the senescence of the broccoli was inhibited. After 28 days of storage, 1-MCP+MEO treatment group could effectively reduce the decrease of total phenol and total flavonoid contents, and combined treatment was 51.9% higher than that of control group, and total flavonoid content was 38.4% higher than that of control group. In addition, the activity of polyphenoloxidase (PPO) and peroxidase (POD) related to enzymatic browning was significantly inhibited, and the activity of PPO and POD were 23.6% and 48.1% lower than that of control group, respectively. Significantly lowered than control group (P<0.05). This study aims to provide a theoretical basis for the development of broccoli preservation technology and a new idea for the research and development of preservatives. [ABSTRACT FROM AUTHOR]

He'nan Medical Team has stationed in Lin county(now Linzhou City) of He'nan Province for 60 years since November 1959 to carry out prevention and treatment research on high incidence of esophageal cancer. In the past 60 years, three generations of medical experts in He'nan Province have made a series of remarkable scientific research achievements in the molecular mechanism and early detection of esophageal cancer, intervention and prevention methods of precancerous lesions, and benefited thousands of patients. Based on the 34-year research of esophageal cancer prevention and treatment in our research group, this paper focuses on the understanding and thinking about the epidemic characteristics, key scientific issues and important research directions of esophageal cancer in China, so as to provide a reference for the prevention and treatment of esophageal cancer.

Aiming at the low efficiency and low carrying capacity of NGWN（Ⅱ） planetary transmission,a design method which improve the efficiency and carrying capacity of the system by using low-loss and asymmetric gears is given. The efficiency influenced by contact ratios and the strength influenced by pressure angles and profile-shift coefficient are studied. On this basis,an optimization model aimed at highest efficiency and power density is described,which is subject to the conditions such as teeth,interference and strength. The research results show that the design method and the optimized design parameters can improve the transmission efficiency and carrying capacity of the system effectively.

Hexachlorocyclohexanes, the organochlorine pesticide, can have toxic response effects to the sensitive microbial flora in soil, resulting in changes of the type and numbers of the sensitive microbial flora. This paper analyzed the response and changes of microorganisms in HCHs polluted soil and the soil after the corresponding ex-situ thermal desorption remediation at different concentration levels, and screened out the microorganisms that can be used as indicator organisms in HCHs contaminated soil. In this paper, the clean soil samples (CK), soil samples, contaminated by HCHs of different levels (H1, H2 and H3) and the soil samples after being remediated (AR) were used as test soil samples. Based on the number of bacteria and the biological indicators of diversity, the differences between soils with different contaminated concentrations and the microbes before and after remediation are explored. The results of the studies showed that compared with CK, the number of bacteria in gradient contaminated soil H1, H2 and H3 was reduced by 95.31%, 94.17% and 94.06%, respectively (P<0.05), and the number of bacteria in AR recovered to some extent but was still notably lower than that of CK, 98.86% lower (P<0.05). There were significant differences in the bacterial diversity of clean soil, contaminated soil and the soil after being remediated. In H3 soil, the characteristic bacteria Proteobacteria and the characteristic bacteria Pseudomonas were significantly enriched, and the proportion reached 99.43% and 97.97%, respectively and the other species'proportion below 1%. Compared with H3, the microbial species composition in AR had been restored to a certain extent, and the diversity of community composition increased, but it was still lower than that of uncontaminated soil in the short term. The average relative abundance of Methylomirabilota, Nitrospira and Planctomycota in clean soil was significantly lower than that in contaminated soil, and in the most contaminated soil H3 their relative abundance was equal to zero, which implied that the above three species bacteria, being rather sensitive to HCHs pollution, could be used as HCHs pollution-sensitive indicator bacteria, and as a new auxiliary detection method. The analysis of environmental factors showed that HCHs noticeably exerted impacts on the bacterial community structure of soil, especially on that of the group H3. [ABSTRACT FROM AUTHOR]

In order to solve the problems of insufficient boost capability and large input current ripple of traditional Boost circuit, a novel DC/DC converter based on coupled inductance is proposed. The zero input current ripple is achieved by combining coupling inductance and capacitance in the front stage of the converter, and voltage gain of the converter is expanded by using coupled inductance voltage doubling unit in the back stage of the converter. A clamping circuit with diode and capacitor is introduced to suppress the voltage spike caused by leakage inductance, thus forming a new converter topology. Based on the circuit theory, the working principle and working characteristics of the converter are analyzed, and by taking the DC boost stage in the photovoltaic power generation system as the application background, experimental verification and analysis are carried out on the Simulink simulation platform. The results show that the converter has the characteristics of the high voltage gain, zero input ripple and low voltage stress. [ABSTRACT FROM AUTHOR]

Aiming at the lack of fault induction motor model in simulation software, an induction motor model with interturn short circuit fault ( ISC) was proposed for virtual simulation experiment. Firstly, based on the characteristics of ISC fault, the quantitative relationship between stator winding coil and motor parameters was used to deduce the resistance matrix and inductance matrix, so as to realize the mathematical modeling of the induction motor with ISC fault. Then the mathematical model was programmed by Simulink simulation software, and it was compared with the actual fault motor for verification. The results showed that the fault motor model could not only accurately simulate the various physical quantities of the motor under ISC fault condition, but also had some advantages, such as simple structure, easy to understand and convenient implementation. Finally, taking the comprehensive practical training of relevant courses as an example, the teaching process of "Virtual and Real Combination" based on the Simulink model was designed . The development and application of fault motor model extend the application scope of simulation experiment platform m practical teaching and improves the teaching effect. [ABSTRACT FROM AUTHOR]

Objective In MEF eukaryotic cells, it was stimulated with NiCl2 with different concentrations and times. It is investigated the change of SOD2 and its potential mechanisms. Methods Cultivating MEF cells line and preparing Nicl2 solutions, it was observed the change of SOD2 stimulated by NiCl2 of different concentrations and times by Western blotting and then judged the potential mechanism. Results After stimulating MEF for continuous 12 hours with different-concentration NiCl2, the expression of SOD2 was orientated to declining and p-Stat3 and p-Akt rising respectively in general. After stimulating MEF for different time period with the same-concentration NiCl2, the expressions of SOD2 and p-Stat3 were both orientated to decline and rising respectively generally. The overall change of SOD2 and p-Stat3 were in consistent. Conclusion Stimulated by NiCl2,SOD2 showed a trend of decline, p-Stat3, probably as the transcription factor, adjusted SOD2 on the transcriptional level. [ABSTRACT FROM AUTHOR]

Objective: To develop and evaluate a nomogram prediction model for the 3-month mortality risk of patients with sepsis-associated acute kidney injury (S-AKI)., Methods: Based on the American Medical Information Mart for Intensive Care- IV (MIMIC- IV), clinical data of S-AKI patients from 2008 to 2021 were collected. Initially, 58 relevant predictive factors were included, with all-cause mortality within 3 months as the outcome event. The data were divided into training and testing sets at a 7 : 3 ratio. In the training set, univariate Logistic regression analysis was used for preliminary variable screening. Multicollinearity analysis, Lasso regression, and random forest algorithm were employed for variable selection, combined with the clinical application value of variables, to establish a multivariable Logistic regression model, visualized using a nomogram. In the testing set, the predictive value of the model was evaluated through internal validation. The receiver operator characteristic curve (ROC curve) was drawn, and the area under the curve (AUC) was calculated to evaluate the discrimination of nomogram model and Oxford acute severity of illness score (OASIS), sequential organ failure assessment (SOFA), and systemic inflammatory response syndrome score (SIRS). The calibration curve was used to evaluate the calibration, and decision curve analysis (DCA) was performed to assess the net benefit at different probability thresholds., Results: Based on the survival status at 3 months after diagnosis, patients were divided into 7 768 (68.54%) survivors and 3 566 (31.46%) death. In the training set, after multiple screenings, 7 variables were finally included in the nomogram model: Logistic organ dysfunction system (LODS), Charlson comorbidity index, urine output, international normalized ratio (INR), respiratory support mode, blood urea nitrogen, and age. Internal validation in the testing set showed that the AUC of nomogram model was 0.81 [95% confidence interval (95%CI) was 0.80-0.82], higher than the OASIS score's 0.70 (95%CI was 0.69-0.71) and significantly higher than the SOFA score's 0.57 (95%CI was 0.56-0.58) and SIRS score's 0.56 (95%CI was 0.55-0.57), indicating good discrimination. The calibration curve demonstrated that the nomogram model's calibration was better than the OASIS, SOFA, and SIRS scores. The DCA curve suggested that the nomogram model's clinical net benefit was better than the OASIS, SOFA, and SIRS scores at different probability thresholds., Conclusions: A nomogram prediction model for the 3-month mortality risk of S-AKI patients, based on clinical big data from MIMIC- IV and including seven variables, demonstrates good discriminative ability and calibration, providing an effective new tool for assessing the prognosis of S-AKI patients.

Objective: To investigate the clinical features and genetic variant of a child with X-linked dominant Alport syndrome (XLAS)., Methods: A child who had presented at the First Affiliated Hospital of Zhengzhou University in May 2019 was selected as the study subject. Clinical data of the child was collected. Next generation sequencing (NGS) was carried out for the child. Candidate variants were validated by Sanger sequencing of his family members., Results: The child, a 12-year-old boy, had mainly manifested gross hematuria, proteinuria, nephrotic syndrome, and progressive renal impairment in conjunct with hearing loss. Kidney biopsy has revealed uneven glomerular basement membrane thickness. DNA sequencing revealed that the child and his mother have both carried a heterozygous c.2632G>A (p.G878R) variant of the COL4A5 gene, for which his father and brother were of the wild type. This variant was unreported previously. Based on the guidelines from the American College of Medical Genetics and Genomics, the variant was classified as pathogenic (PS1+PM1+PM2&#95;Supporting+PP3)., Conclusion: The maternally derived hemizygous c.2632G>A (p.G878R) variant of the COL4A5 gene probably underlay the XLAS in this child. Above finding has enriched the mutational spectrum of the COL4A5 gene.

Systemic lupus erythematosus (SLE) is a multiorgan-involved autoimmune disease, and it can overlap organ-specific autoimmune diseases such as autoimmune thyroid diseases, autoimmune hepatitis and inflammatory bowel disease. There may be some association between SLE and these autoimmune diseases, such as common immunological and genetic basis, but the pathogenic mechanism is still unclear. This review focuses on current knowledge regarding the prevalence and possible pathogenesis of SLE overlapping the above three autoimmune diseases.

Objective: To investigate the expression and the distribution of human beta defensin (hBD)-4 in healthy gingiva., Methods: Healthy gingival specimens were collected. The expression of hBD-4 peptides in 18 gingival specimens were detected by immunohistochemistry. The hBD-4 mRNA were determined in freshly isolated gingival tissue by real time reverse transcription-polymerase chain reaction (real time RT-PCR) in 30 gingival specimens., Results: In 18 gingival specimens, hBD-4 peptides were expressed in 13 gingival specimens. In 30 gingival specimens, hBD-4 were detected in 4 gingival specimens by real time RT-PCR., Conclusion: The distribution and the expression levels of hBD-4 are different in healthy gingiva. This result may suggest that the hBD-4 play a role in maintaining the periodontal health.