318 research outputs found
Nonzero Sum Differential Game of Mean-Field BSDEs with Jumps under Partial Information
This paper is concerned with a kind of nonzero sum differential game of mean-field backward stochastic differential equations with jump (MF-BSDEJ), in which the coefficient contains not only the state process but also its marginal distribution. Moreover, the cost functional is also of mean-field type. It is required that the control is adapted to a subfiltration of the filtration generated by the underlying Brownian motion and Poisson random measure. We establish a necessary condition in the form of maximum principle with Pontryagin’s type for open-loop Nash equilibrium point of this type of partial information game and then give a verification theorem which is a sufficient condition for Nash equilibrium point. The theoretical results are applied to study a partial information linear-quadratic (LQ) game
Estimation of affinities of ligands in mixtures via magnetic recovery of target-ligand complexes and chromatographic analyses: chemometrics and an experimental model
<p>Abstract</p> <p>Background</p> <p>The combinatorial library strategy of using multiple candidate ligands in mixtures as library members is ideal in terms of cost and efficiency, but needs special screening methods to estimate the affinities of candidate ligands in such mixtures. Herein, a new method to screen candidate ligands present in unknown molar quantities in mixtures was investigated.</p> <p>Results</p> <p>The proposed method involves preparing a processed-mixture-for-screening (PMFS) with each mixture sample and an exogenous reference ligand, initiating competitive binding among ligands from the PMFS to a target immobilized on magnetic particles, recovering target-ligand complexes in equilibrium by magnetic force, extracting and concentrating bound ligands, and analyzing ligands in the PMFS and the concentrated extract by chromatography. The relative affinity of each candidate ligand to its reference ligand is estimated <it>via </it>an approximation equation assuming (a) the candidate ligand and its reference ligand bind to the same site(s) on the target, (b) their chromatographic peak areas are over five times their intercepts of linear response but within their linear ranges, (c) their binding ratios are below 10%. These prerequisites are met by optimizing primarily the quantity of the target used and the PMFS composition ratio.</p> <p>The new method was tested using the competitive binding of biotin derivatives from mixtures to streptavidin immobilized on magnetic particles as a model. Each mixture sample containing a limited number of candidate biotin derivatives with moderate differences in their molar quantities were prepared <it>via </it>parallel-combinatorial-synthesis (PCS) without purification, or <it>via </it>the pooling of individual compounds. Some purified biotin derivatives were used as reference ligands. This method showed resistance to variations in chromatographic quantification sensitivity and concentration ratios; optimized conditions to validate the approximation equation could be applied to different mixture samples. Relative affinities of candidate biotin derivatives with unknown molar quantities in each mixture sample were consistent with those estimated by a homogenous method using their purified counterparts as samples.</p> <p>Conclusions</p> <p>This new method is robust and effective for each mixture possessing a limited number of candidate ligands whose molar quantities have moderate differences, and its integration with PCS has promise to routinely practice the mixture-based library strategy.</p
The cosmic ray test of MRPCs for the BESIII ETOF upgrade
In order to improve the particle identification capability of the Beijing
Spectrometer III (BESIII),t is proposed to upgrade the current endcap
time-of-flight (ETOF) detector with multi-gap resistive plate chamber (MRPC)
technology. Aiming at extending ETOF overall time resolution better than 100ps,
the whole system including MRPC detectors, new-designed Front End Electronics
(FEE), CLOCK module, fast control boards and time to digital modules (TDIG),
was built up and operated online 3 months under the cosmic ray. The main
purposes of cosmic ray test are checking the detectors' construction quality,
testing the joint operation of all instruments and guaranteeing the performance
of the system. The results imply MRPC time resolution better than 100,
efficiency is about 98 and the noise rate of strip is lower than
1() at normal threshold range, the details are discussed and
analyzed specifically in this paper. The test indicates that the whole ETOF
system would work well and satisfy the requirements of upgrade
Triptolide modulates adriamycin sensitivity via regulating Mir-21 and Bcl-2 expression in K562/A02 cell line
Drug resistance is a major obstacle for successful treatment of leukemia. Increasing evidence suggests that microRNA-21 (miR-21) is over-expressed in K562/A02 cell line, promoting drug resistance. The aim of our present study is to investigate the reversal effects of triptolide on drug resistance in adriamycin-resistant cells. Cell viability was measured by MTT assays and adriamycin induced apoptosis was evaluated by flow cytometry. Levels of miR-21 quantified by real-time PCR. Bcl-2 protein level were measured by western blot. TPL enhanced sensitivity of K562/A02 cells to adriamycin and promoted adriamycin–induced apoptosis. Levels of miR-21 and Bcl-2 was significantly decreased after triptolide treatment. Transfection with anti-miR-21, a significant up-regulation of sensitivity to adriamycin and a significant down-regulation of Bcl-2 protein level was noted in K562/A02 cells. Our study suggests that triptolide significantly sensitizes K562/A02 cell to adriamycin by inducing apoptosis and these effects of triptolide may be due to its down-regulation of miR-21.Colegio de Farmacéuticos de la Provincia de Buenos Aire
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1H NMR-based metabolic profiling combined with multivariate data analysis was used to explore the metabolic phenotype of functional dyspepsia (FD) in stressed rats and evaluate the intervention effects of the Chinese medicine Weikangning (WKN). After a 7-day period of model establishment, a 14-day drug administration schedule was conducted in a WKN-treated group of rats, with the model and normal control groups serving as negative controls. Based on 1H NMR spectra of urine and serum from rats, PCA, PLS-DA, and OPLS-DA were performed to identify changing metabolic profiles. According to the key metabolites determined by OPLS-DA, alterations in energy metabolism, stress-related metabolism, and gut microbiota were found in FD model rats after stress stimulation, and these alterations were restored to normal after WKN administration. This study may provide new insights into the relationship between FD and psychological stress and assist in research into the metabolic mechanisms involved in Chinese medicine
Stability of SARS-CoV-2 in cold-chain transportation environments and the efficacy of disinfection measures
BackgroundLow temperature is conducive to the survival of COVID-19. Some studies suggest that cold-chain environment may prolong the survival of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and increase the risk of transmission. However, the effect of cold-chain environmental factors and packaging materials on SARS-CoV-2 stability remains unclear.MethodsThis study aimed to reveal cold-chain environmental factors that preserve the stability of SARS-CoV-2 and further explore effective disinfection measures for SARS-CoV-2 in the cold-chain environment. The decay rate of SARS-CoV-2 pseudovirus in the cold-chain environment, on various types of packaging material surfaces, i.e., polyethylene plastic, stainless steel, Teflon and cardboard, and in frozen seawater was investigated. The influence of visible light (wavelength 450 nm-780 nm) and airflow on the stability of SARS-CoV-2 pseudovirus at -18°C was subsequently assessed.ResultsExperimental data show that SARS-CoV-2 pseudovirus decayed more rapidly on porous cardboard surfaces than on nonporous surfaces, including polyethylene (PE) plastic, stainless steel, and Teflon. Compared with that at 25°C, the decay rate of SARS-CoV-2 pseudovirus was significantly lower at low temperatures. Seawater preserved viral stability both at -18°C and with repeated freeze−thaw cycles compared with that in deionized water. Visible light from light-emitting diode (LED) illumination and airflow at -18°C reduced SARS-CoV-2 pseudovirus stability.ConclusionOur studies indicate that temperature and seawater in the cold chain are risk factors for SARS-CoV-2 transmission, and LED visible light irradiation and increased airflow may be used as disinfection measures for SARS-CoV-2 in the cold-chain environment
Encephalitozoon hellem infection after haploidentical allogeneic hematopoietic stem cell transplantation in children: a case report
BackgroundEncephalitozoon hellem (E. hellem) infection is a zoonotic disease, rarely observed in individuals, causing various clinical manifestations including diarrhea, keratoconjunctivitis, cystitis, etc. E. hellem infection after hematopoietic stem-cell transplantation (HSCT) is a rare, serious complication.Case presentationHerein, we present a case of E. hellem infection developing during HLA-haploidentical HSCT in a 9-year-old boy who suffered from aplastic anemia. On 15 days after HSCT, the patient developed recurrent and prolonged fever, diarrhea and hematuria. It is challenging to differentiate whether the symptoms mentioned in this case are caused by graft-versus-host disease (GVHD) or a specific infection. Based on the result of metagenomic next-generation sequencing (mNGS) and clinical observation, the patient was diagnosed as E. hellem infection, and received albendazole and decreased the immunosuppressive treatment. Finally, he had recovered.ConclusionWe should pay attention to the uncommon disease caused by the E. hellem infection after HSCT, especially in cases with immune reconstitution unrecovered. Among those rare infection, mNGS can be performed for better understanding the source of infection and targeted therapy, which can benefit the patients
Shufeng Jiedu Capsules Alleviate Lipopolysaccharide-Induced Acute Lung Inflammatory Injury via Activation of GPR18 by Verbenalin
Background/Aims: Acute respiratory tract infection (ARTI) is the most common reason for outpatient physician office visits. Although powerful and significant in the treatment of infections, antibiotics used for ARTI inappropriately have been an important contributor to antibiotic resistance. We previously reported that Shufeng Jiedu Capsule (SJC) can effectively amplify anti-inflammatory signaling during infection. In this study, we aimed to systematically explore its composition and the mechanism of its effects in ARTI. Methods: Pseudomonas aeruginosa (PAK) strain was used to generate a mouse model of ARTI, which were then treated with different drugs or compounds to determine the corresponding anti-inflammatory roles. High-performance liquid chromatography-quadrupole time of flight-tandem mass spectrometry. was conducted to detect the chemical compounds in SJC. RNAs from the lung tissues of mice were prepared for microarray analysis to reveal globally altered genes and the pathways involved after SJC treatment. Results: SJC significantly inhibited the expression and secretion of inflammatory factors from PAK-induced mouse lung tissues or lipopolysaccharide-induced peritoneal macrophages. Verbenalin, one of the bioactive compounds identified in SJC, also showed notable anti-inflammatory effects. Microarray data revealed numerous differentially expressed genes among the different treatment groups; here, we focused on studying the role of GPR18. We found that the anti-inflammatory role of verbenalin was attenuated in GPR18 knockout mice compared with wild-type mice, although no statistically significant difference was observed in the untreated PAK-induced mice types. Conclusion: Our data not only showed the chemical composition of SJC, but also demonstrated that verbenalin was a significant anti-inflammatory compound, which may function through GPR18
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