Long-term predictions of current confirmed and dead cases of COVID-19 in China by the non-autonomous delayed epidemic models

In this paper, we make long-term predictions based on numbers of current confirmed cases, accumulative dead cases of COVID-19 in different regions in China by modeling approach. Firstly, we use the SIRD epidemic model (S-Susceptible, I-Infected, R-Recovered, D-Dead) which is a non-autonomous dynamic system with incubation time delay to study the evolution of the COVID-19 in Wuhan City, Hubei Province and China Mainland. According to the data in the early stage issued by the National Health Commission of China, we can accurately estimate the parameters of the model, and then accurately predict the evolution of the COVID-19 there. From the analysis of the issued data, we find that the cure rates in Wuhan City, Hubei Province and China Mainland are the approximately linear increasing functions of time t and their death rates are the piecewisely decreasing functions. These can be estimated by finite difference method. Secondly, we use the delayed SIRD epidemic model to study the evolution of the COVID-19 in the Hubei Province outside Wuhan City. We find that its cure rate is an approximately linear increasing function and its death rate is nearly a constant. Thirdly, we use the delayed SIR epidemic model (S-Susceptible, I-Infected, R-Removed) to predict those of Beijing, Shanghai, Zhejiang and Anhui Provinces. We find that their cure rates are the approximately linear increasing functions and their death rates are the small constants. The results indicate that it is possible to make accurate long-term predictions for numbers of current confirmed, accumulative dead cases of COVID-19 by modeling. In this paper the results indicate we can accurately obtain and predict the turning points, the end time and the maximum numbers of the current infected and dead cases of the COVID-19 in China. In spite of our simple method and small data, it is rather effective in the long-term prediction of the COVID-19.     

Sidt2 is a key protein in the autophagy-lysosomal degradation pathway and is essential for the maintenance of kidney structure and filtration function

The regulation and homeostasis of autophagy are essential for maintaining organ morphology and function. As a lysosomal membrane protein, the effect of Sidt2 on kidney structure and renal autophagy is still unknown. In this study, we found that the kidneys of Sidt2^−/− mice showed changes in basement membrane thickening, foot process fusion, and mitochondrial swelling, suggesting that the structure of the kidney was damaged. Increased urine protein at 24 h indicated that the kidney function was also damaged. At the same time, the absence of Sidt2 caused a decrease in the number of acidic lysosomes, a decrease in acid hydrolase activity and expression in the lysosome, and an increase of pH in the lysosome, suggesting that lysosomal function was impaired after Sidt2 deletion. The accumulation of autophagolysosomes, increased LC3-II and P62 protein levels, and decreased P62 mRNA levels indicated that the absence of the Sidt2 gene caused abnormal autophagy pathway flow. Chloroquine experiment, immunofluorescence autophagosome, and lysosome fusion assay, and Ad-mcherry-GFP-LC3B further indicated that, after Sidt2 deletion, the production of autophagosomes did not increase, but the fusion of autophagosomes and lysosomes and the degradation of autophagolysosomes were impaired. When incubating Sidt2^−/− cells with the autophagy activator rapamycin, we found that it could activate autophagy, which manifested as an increase in autophagosomes, but it could not improve autophagolysosome degradation. Meanwhile, it further illustrated that the Sidt2 gene plays an important role in the smooth progress of autophagolysosome processes. In summary, the absence of the Sidt2 gene caused impaired lysosome function and a decreased number of acidic lysosomes, leading to formation and degradation disorders of the autophagolysosomes, which eventually manifested as abnormal kidney structure and function. Sidt2 is essential in maintaining the normal function of the lysosomes and the physiological stability of the kidneys.Subject terms: Macroautophagy, Kidney diseases     

USP3 promotes gastric cancer progression and metastasis by deubiquitination-dependent COL9A3/COL6A5 stabilisation

As an important regulator of intracellular protein degradation, the mechanism of the deubiquitinating enzyme family in tumour metastasis has received increasing attention. Our previous study revealed that USP3 promotes tumour progression and is highly expressed in gastric cancer (GC). Herein, we report two critical targets, COL9A3 and COL6A5, downstream of USP3, via the isobaric tags for relative and absolute quantification technique. Mechanistically, we observed that USP3 interacted with and stabilised COL9A3 and COL6A5 via deubiquitination in GC. Importantly, we found that COL9A3 and COL6A5 were essential mediators of USP3-modulated oncogenic activity in vitro and in vivo. Examination of clinical samples confirmed that elevated expression of USP3, concomitant with increased COL9A3 and COL6A5 abundance, correlates with human GC progression. These data suggest that USP3 promotes GC progression and metastasis by deubiquitinating COL9A3 and COL6A5. These findings identify a mechanism of GC metastasis regarding USP3-mediated deubiquitinating enzyme activity and suggest potential therapeutic targets for GC management.Subject terms: Gastric cancer, Ubiquitylation     

小麦成熟胚无性系后代的性状表现

观察了来源于小麦成熟胚培养再生植株中R2代无性系农艺性状的变异。结果表明,R2无性系的株高、穗粒数、千粒重、抽穗期和穗长都发生了不同变异,每个农艺性状的变异频代率较高,并且穗系间也有变异,还对无性系的变异和利用进行了讨沦。     

Isolation and Characterization of Total DNA from Several Endangered Species and Their Allies

A low pH extraction medium with high salts, which avoids ionization and subsequent oxidation of phenolic compounds during tissue grinding and precipitation of large amounts of materials, were successfully used to obtain total DNA from Cathaya argyrophylla Chun et Kuang, Paeonia suffruticosa var. spontanea, Cimici fuga nanchuanensis Hsiao, Adenophora potaninii (Congeneric species with A. lobophylla) etc. The DNA yields, quality and purity were characterized. These isolated DNA could be used directly for RFLP and RAPD analysis which are useful as molecular genetic markers without sedimentation in cesium chloride gradient or column chromatography. A fast, inexpensive and reliable procedure has been developed for detecting the genetic diversity of endangered plants.     

Design and synthesis of amidino-tyrosine derivatives as non-peptide fibrinogen receptor antagonists.

The design, synthesis and antiaggregation activity of amidino-tyrosine derivatives based on Arg-Gly-Asp (RGD) tripeptide sequence as non-peptide fibrinogen receptor antagonists is described. Optimization of the spacer and the substituent at the C-terminal is reported.     

我国D2-43病毒株PrM-E基因的重组SFV的制备及生物学鉴定

 为构建含PrM E基因的重组SFV病毒 ,将含我国登革 2型病毒PrM E基因的SFV表达载体和辅助载体DNA线性化后 ,进行体外转录 .然后将获得的 2种RNA转录物共转染BHK2 1细胞 ,以RT PCR法证明转染后的细胞培养上清中含有重组SFV .进一步将该重组病毒经蛋白酶激活后可使BHK2 1细胞产生细胞病变 ,并且以间接免疫荧光法在感染细胞内可检测到登革 2型病毒所特有的蛋白 .含我国登革 2型病毒PrM E基因的重组SFV的获得 ,为进一步观察该重组病毒的免疫原性奠定了基础 ,从而为登革新型疫苗的研制提供新途径     

阳原石核的动态类型学研究及其工艺思想分析

本文从动态类型学角度把阳原石核的工艺程序划分为四道工序和两个亚类型,论证了这种石核发生形态变化的机制。在工艺特征上,阳原石核与日本北海道的(山上下)下型细石核相当,从而证明两地在旧石器时代晚期曾有共同的工艺思想。