117 research outputs found
Construction of a Recombinant Eukaryotic Expression Plasmid Containing Human Calcitonin Gene and Its Expression in NIH3T3 Cells
Aim. To construct a recombinant eukaryotic expression plasmid containing human calcitonin (hCT) gene and express the gene in murine fibroblast NIH3T3 cells. Materials and Methods. A murine Igκ-chain leader sequence and hCT gene were synthesized and cloned into pCDNA3.0 to form the pCDNA3.0-Igκ-hCT eukaryotic expression vector, which was transfected into NIH3T3 cells. The mRNA and protein expressions and secretion of hCT were detected. Primarily cultured osteoclasts were incubated with the supernatant of pCDNA3.0-Igk-hCT-transfected NIH3T3 cells, and their numbers were counted and morphology observed.
Results. The expression and secretion of hCT were successfully detected in pCDNA3.0-Igk-hCT-transfected NIH3T3 cells. The number of osteoclasts was decreased and the cells became crumpled when they were incubated with the supernatant of pCDNA3.0-Igk-hCT-transfected NIH3T3 cells.
Conclusion. A recombinant eukaryotic expression vector containing hCT gene was successfully constructed and expressed in NIH3T3 cells. The secreted recombinant hCT inhibited the growth and morphology of osteoclasts
Synthesis and Characterization of One-Dimensional Porous (Zn,Cd)S/SiO 2
One-dimensional (1D) porous (Zn,Cd)S/SiO2 composite nanostructural materials were synthesized by thermal evaporation of ZnS and CdS mixture powder at 950°C. The nanomaterials were collected from silicon wafers which were coated with 10 nm thick gold and were set apart from the source about 10 cm away. The diameter of the as-prepared 1D porous composite nanostructures is in the range of 1–1.5 μm and their lengths are up to tens to hundreds of micrometers. The photoluminescence spectra measured at different temperatures of the prepared nanostructures display a similar broadband signature, which can be fitted by Gaussian function into three emission peaks centered at 477, 536, and 588 nm and attributed to band edge emission, neutral oxygen vacancies, and antisymmetric stretching of Si–O–Si and nonstoichiometric SiOx (1<x<2), respectively
Surrogate-based optimization with improved support vector regression for non-circular vent hole on aero-engine turbine disk
Abstract(#br)This paper investigates a structural optimization for the non-circular vent hole on an aero-engine turbine disk. A novel optimization approach, namely SO-ISVR (the surrogate-based optimization using an improved support vector regression), for the vent hole design is developed. ISVR (the improved support vector regression) is proposed to extract some ignored valuable information from the existing training data by using the least squares method, so as to improve the performance of SVR (support vector regression). To validate the advantages of SO-ISVR, another two optimization approaches are also developed. They are SO-SVR (the surrogate-based optimization using SVR) and FEMO (the finite element method based optimization). The results show that ISVR is suitable and valuable in engineering optimization. Compared to the initial scheme, the maximum von Mises stress of the optimal scheme obtained by SO-ISVR is reduced from 1189.488 MPa to 948.530 MPa. Further comparative study for SO-ISVR, SO-SVR, and FEMO demonstrates that SO-ISVR possesses some advantages in both computational efficiency and optimization effect
Structural, Antigenic, and Evolutionary Characterizations of the Envelope Protein of Newly Emerging Duck Tembusu Virus
Since the first reported cases of ducks infected with a previously unknown flavivirus in eastern China in April 2010, the virus, provisionally designated Duck Tembusu Virus (DTMUV), has spread widely in domestic ducks in China and caused significant economic losses to poultry industry. In this study, we examined in detail structural, antigenic, and evolutionary properties of envelope (E) proteins of six DTMUV isolates spanning 2010–2012, each being isolated from individual farms with different geographical locations where disease outbreaks were documented. Structural analysis showed that E proteins of DTMUV and its closely related flavivirus (Japanese Encephalitis Virus) shared a conserved array of predicted functional domains and motifs. Among the six DTMUV strains, mutations were observed only at thirteen amino acid positions across three separate domains of the E protein. Interestingly, these genetic polymorphisms resulted in no detectable change in viral neutralization properties as demonstrated in a serum neutralization assay. Furthermore, phylogenetic analysis of the nucleotide sequences of the E proteins showed that viruses evolved into two distinct genotypes, termed as DTMUV.I and DTMUV.II, with II emerging as the dominant genotype. New findings described here shall give insights into the antigenicity and evolution of this new pathogen and provide guidance for further functional studies of the E protein for which no effective vaccine has yet been developed
Recombinant proteins A29L, M1R, A35R, and B6R vaccination protects mice from mpox virus challenge
Since May 2022, mutant strains of mpox (formerly monkeypox) virus (MPXV) have been rapidly spreading among individuals who have not traveled to endemic areas in multiple locations, including Europe and the United States. Both intracellular and extracellular forms of mpox virus have multiple outer membrane proteins that can stimulate immune response. Here, we investigated the immunogenicity of MPXV structural proteins such as A29L, M1R, A35R, and B6R as a combination vaccine, and the protective effect against the 2022 mpox mutant strain was also evaluated in BALB/c mice. After mixed 15 μg QS-21 adjuvant, all four virus structural proteins were administered subcutaneously to mice. Antibody titers in mouse sera rose sharply after the initial boost, along with an increased capacity of immune cells to produce IFN-γ alongside an elevated level of cellular immunity mediated by Th1 cells. The vaccine-induced neutralizing antibodies significantly inhibited the replication of MPXV in mice and reduced the pathological damage of organs. This study demonstrates the feasibility of a multiple recombinant vaccine for MPXV variant strains
Tuberous Sclerosis Complex With Multiple Organ Tumors: Case Report and Literature Review
Pancreatic neuroendocrine neoplasms (PNEN) are tumors that originate from neuroendocrine cells. Only about 1% patients are related to mutation of tuberous sclerosis complex gene. Here, we reported a rare case with involvement of multiple organs and space-occupying lesions. Initially, the patient was thought to have metastasis of a pancreatic tumor. However, the patient was diagnosed as pancreatic neuroendocrine tumors, liver perivascular epithelioid tumors, splenic hamartoma, and renal angiomyolipoma by pathological examination after surgery. We performed genetic mutation detection to identify that tuberous sclerosis complex 2 gene presented with a heterozygous variant. Tuberous sclerosis often presents with widespread tumors, but it is less common to present with pancreatic neuroendocrine tumors and liver perivascular tumors as highlighted in the case. So we analyzed the relationship between TSC gene mutations and related tumors. And we also reviewed the current molecular mechanisms and treatments for tuberous sclerosis complex
Availability of essential medicines, progress and regional distribution in China: a systematic review and meta-analysis
BackgroundEssential medicines are the backbone of healthcare and meet the priority healthcare needs of the population. However, approximately one-third of the global population does not have access to essential medicines. Although China formulated essential medicine policies in 2009, the progress of availability of essential medicines and regional variations remains unknown. Therefore, this study was conducted to evaluate the availability of essential medicines, their progress, and regional distribution in China in the last decade.MethodsWe searched eight databases from their inception to February 2022, relevant websites, and reference lists of included studies. Two reviewers selected studies, extracted data, and evaluated the risk of bias independently. Meta-analyses were performed to quantify the availability of essential medicines, their progress, and regional distribution.ResultsOverall 36 cross-sectional studies conducted from 2009 to 2019 were included, with regional data for 14 provinces. The availability of essential medicines in 2015–2019 [28.1%, 95% confidence interval (CI): 26.4–29.9%] was similar to that in 2009–2014 (29.4%, 95% CI: 27.5–31.3%); lower in the Western region (19.8%, 95% CI: 18.1–21.5%) than Eastern (33.8%, 95% CI: 31.6–36.1%) and Central region (34.5%, 95% CI: 30.6–38.5%); very low for 8 Anatomical Therapeutic Chemical (ATC) categories (57.1%), and low for 5 categories (35.7%) among all ATC groups.ConclusionThe availability of essential medicines in China is low compared with the World Health Organization goal, has not changed much in the last decade, is unequal across regions, and lacks data for half of provinces. For policy-making, the monitoring system of the availability of essential medicines is to be strengthened to enable long-term surveillance, especially in provinces where the data has been missing. Meanwhile, Joint efforts from all stakeholders are warranted to improve the availability of essential medicines in China toward the universal health coverage target.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=315267, identifier: PROSPERO CRD42022315267
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