Assembly-oriented reliability analysis method for the top-connection structure of a nuclear fuel assembly

The nuclear fuel assembly is the core component of a nuclear reactor.In a pressurized water reactor fuel assembly,the top-connection structure connects the top nozzle to the guide thimble.Its performance reliability is essential for the stability of the nuclear fuel assembly.In this study,an assembly-oriented reliability analysis method for top-connection structures is presented by establishing an assembly-oriented top-connection structure parameter modeling method and a nonlinear contact gap and penetration correction method.A reliability model of the top-connection assembly structure,including multiple stochastic design variables,was constructed,and the overall reliability of the top-connection assembly structure was obtained via a Kriging model and Monte Carlo simulation.The acquired experimental data were consistent with real-world failure conditions,which verified the practicability and feasibility of the reliability analysis method proposed in this study.

Prediction of treatment response to antipsychotic drugs for precision medicine approach to schizophrenia:randomized trials and multiomics analysis

Background:Choosing the appropriate antipsychotic drug(APD)treatment for patients with schizophrenia(SCZ)can be challenging,as the treatment response to APD is highly variable and difficult to predict due to the lack of effective biomarkers.Previous studies have indicated the association between treatment response and genetic and epigenetic factors,but no effective biomarkers have been identified.Hence,further research is imperative to enhance precision medicine in SCZ treatment.Methods:Participants with SCZ were recruited from two randomized trials.The discovery cohort was recruited from the CAPOC trial(n=2307)involved 6 weeks of treatment and equally randomized the participants to the Olanzapine,Risperidone,Quetiapine,Aripiprazole,Ziprasidone,and Haloperidol/Perphenazine(subsequently equally assigned to one or the other)groups.The external validation cohort was recruited from the CAPEC trial(n=1379),which involved 8 weeks of treatment and equally randomized the participants to the Olanzapine,Risperidone,and Aripiprazole groups.Additionally,healthy controls(n=275)from the local community were utilized as a genetic/epigenetic reference.The genetic and epigenetic(DNA methylation)risks of SCZ were assessed using the polygenic risk score(PRS)and polymethylation score,respectively.The study also examined the genetic-epigenetic interactions with treatment response through differential methylation analysis,methylation quantitative trait loci,colocalization,and promoteranchored chromatin interaction.Machine learning was used to develop a prediction model for treatment response,which was evaluated for accuracy and clinical benefit using the area under curve(AUC)for classification,R^(2) for regression,and decision curve analysis.Results:Six risk genes for SCZ(LINC01795,DDHD2,SBNO1,KCNG2,SEMA7A,and RUFY1)involved in cortical morphology were identified as having a genetic-epigenetic interaction associated with treatment response.The developed and externally validated prediction model,which incorporated clinical information,PRS,genetic risk score(GRS),and proxy methylation level(proxyDNAm),demonstrated positive benefits for a wide range of patients receiving different APDs,regardless of sex[discovery cohort:AUC=0.874(95%CI 0.867-0.881),R^(2)=0.478;external validation cohort:AUC=0.851(95%CI 0.841-0.861),R^(2)=0.507].Conclusions:This study presents a promising precision medicine approach to evaluate treatment response,which has the potential to aid clinicians in making informed decisions about APD treatment for patients with SCZ.Trial registration Chinese Clinical Trial Registry(https://www.chictr.org.cn/),18 Aug 2009 retrospectively registered:CAPOC-ChiCTR-RNC-09000521(https://www.chictr.org.cn/showproj.aspx?proj=9014),CAPEC-ChiCTRRNC-09000522(https://www.chictr.org.cn/showproj.aspx?proj=9013).

Flow field fusion simulation method based on model features and its application in CRDM

The control rod drive mechanism(CRDM)is an essential part of the control and safety protection system of pressurized water reactors.Current CRDM simulations are mostly performed collectively using a single method,ignoring the influence of multiple motion units and the differences in various features among them,which strongly affect the efficiency and accuracy of the simulations.In this study,we constructed a flow field fusion simulation method based on model features by combining key motion unit analysis and various simulation methods and then applied the method to the CRDM simulation process.CRDM performs motion unit decomposition through the structural hierarchy of function-movement-action method,and the key meta-actions are identified as the nodes in the flow field simulation.We established a fused feature-based multimethod simulation process and processed the simulation methods and data according to the features of the fluid domain space and the structural complexity to obtain the fusion simulation results.Compared to traditional simulation methods and real measurements,the simulation method provides advantages in terms of simulation efficiency and accuracy.

生物钟基因Rev-erb和ROR在抗炎及免疫调节中的作用研究进展

生物钟广泛存在于生物体,调节生物的生长发育。随着生物钟分子机制的逐步明确,学者发现生物钟基因Rev-erb和ROR参与许多生理过程,并在抗炎及免疫调节过程中发挥重要作用。针对该类受体的靶向研究可用于调控机体免疫。该文重点介绍生物钟基因Rev-erb和ROR在抗炎及免疫调节中的作用,包括该受体的相关作用机制及针对该受体的配体研究。

Interfacial microstructure and mechanical properties of GH99 superalloy and Nb brazed joint using Cu75Pt25 filler

Cu75Pt25 brazing filler was applied to brazing GH99 superalloy to Nb,and the sound joints were obtained by adjusting brazing parameters.The typical interfacial microstructure of the brazed joint was Nb/Nb7Ni6+NbNi3/Ni(s,s)+Cr-rich NbNi3+(NbCr2+NbNi3)/GH99.The effects of brazing temperature and holding time on the interfacial microstructure of GH99/Cu75Pt25/Nb joints were studied.The results showed that the solution and diffusion of Ni atoms from GH99 substrate into brazing seam played a critical role in the interfacial microstructure evolution.As the brazing temperature rose,the Nb−Ni reaction layer was formed instead of the initial Nb3Pt layer,and the thickness increased firstly and then remained constant.The highest shear strength of the joint reached 152 MPa when brazed at 1150℃ for 15 min.All of the joints presented a brittle fracture mode during shear test,and the fracture location changed from Nb3Pt layer to Nb−Ni compounds layer.

Transcriptomic analyses of humans and mice provide insights into depression

Accumulating studies have been conducted to identify risk genes and relevant biological mechanisms underlying major depressive disorder(MDD).In particular,transcriptomic analyses in brain regions engaged in cognitive and emotional processes,e.g.,the dorsolateral prefrontal cortex(DLPFC),have provided essential insights.Based on three independent DLPFC RNA-seq datasets of 79 MDD patients and 75 healthy controls,we performed differential expression analyses using two alternative approaches for cross-validation.We also conducted transcriptomic analyses in mice undergoing chronic variable stress(CVS)and chronic social defeat stress(CSDS).We identified 12 differentially expressed genes(DEGs)through both analytical methods in MDD patients,the majority of which were also dysregulated in stressed mice.Notably,the mRNA level of the immediate early gene FOS(Fos proto-oncogene)was significantly decreased in both MDD patients and CVS-exposed mice,and CSDSsusceptible mice exhibited a greater reduction in Fos expression compared to resilient mice.These findings suggest the potential key roles of this gene in the pathogenesis of MDD related to stress exposure.Altered transcriptomes in the DLPFC of MDD patients might be,at least partially,the result of stress exposure,supporting that stress is a primary risk factor for MDD.

Nitrogen-doped pyrogenic carbonaceous matter facilitates azo dye decolorization by sulfide: The important role of graphitic nitrogen

Pyrogenic carbonaceous matter(PCM) catalyzes azo dye decolorization by sulfide, but the nitrogen doping catalytic mechanisms are poorly understood. In this study, we found that stagnate time of azo dye methyl orange(MO) decolorization was reduced to 0.54-18.28 min in the presence of various nitrogen-doped graphenes(NGs), remarkably lower compared to graphene itself. Particularly, graphitic nitrogen played a critical role in NGs-catalyzed MO decolorization by sulfide. Gas chromatography-mass spectrometry and in-situ surface Raman analysis demonstrated that doping nitrogen, especially graphite one facilitated reactive intermediate polysulfides formation. This is attributed to the improved electron conductivity through graphitic nitrogen doping, and the enhanced interactions between sulfide and carbon atoms bonded to graphitic nitrogen. This study not only provides a better understanding of PCM impact on transformations and fates of organic pollutants in natural environments, but also offer a new regulation strategy for more efficient wastewater treatment processes in PCM-catalyzed engineering systems.

Zirconium oxide ceramic foam: a promising supporting biomaterial for massive production of glial cell line-derived neurotrophic factor

This study investigated the potential application of a zirconium oxide （ZrO2） ceramic foam culturing system to the production of glial cell line-derived neurotrophic factor （GDNF）. Three sets of ZrO2 ceramic foams with different pore densities of 10, 20, and 30 pores per linear inch （PPI） were prepared to support a 3D culturing system. After primary astrocytes were cultured in these systems, production yields of GDNF were evaluated. The biomaterial bio- compatibility, cell proliferation and activation of cellular signaling pathways in GDNF synthesis and secretion in the culturing systems were also assessed and compared with a conventional culturing system. In this study, we found that the ZrO2 ceramic foam culturing system was biocompatible, using which the GDNF yields were elevated and sustained by stimulated cell proliferation and activation of signaling pathways in astrocytes cultured in the system. In conclusion, the ZrO2 ceramic foam is promising for the development of a GDNF mass production device for Parkinson＇s disease treatment.

Enhancing transjugular intrahepatic portosystemic shunt procedure efficiency with digital subtraction angiography image overlay technology in esophagogastric variceal bleeding

BACKGROUND Transjugular intrahepatic portosystemic shunt(TIPS)is a pivotal intervention for managing esophagogastric variceal bleeding in patients with chronic hepatic schistosomiasis.AIM To evaluate the efficacy of digital subtraction angiography image overlay tech-nology(DIT)in guiding the TIPS procedure.METHODS We conducted a retrospective analysis of patients who underwent TIPS at our hospital,comparing outcomes between an ultrasound-guided group and a DIT-guided group.Our analysis focused on the duration of the portosystemic shunt puncture,the number of punctures needed,the total surgical time,and various clinical indicators related to the surgery.RESULTS The study included 52 patients with esophagogastric varices due to chronic hepatic schistosomiasis.Results demonstrated that the DIT-guided group expe-rienced significantly shorter puncture times(P<0.001)and surgical durations(P=0.022)compared to the ultrasound-guided group.Additionally,postoperative assessments showed significant reductions in aspartate aminotransferase,B-type natriuretic peptide,and portal vein pressure in both groups.Notably,the DIT-guided group also showed significant reductions in total bilirubin(P=0.001)and alanine aminotransferase(P=0.023).CONCLUSION The use of DIT for guiding TIPS procedures highlights its potential to enhance procedural efficiency and reduce surgical times in the treatment of esophagogastric variceal bleeding in patients with chronic hepatic schistoso-miasis.

Review of optical tweezers in vacuum

As a versatile tool for trapping and manipulating neutral particles, optical tweezers have been studied in a broad range of fields such as molecular biology, nanotechnology, and experimentally physics since Arthur Ashkin pioneered the field in the early 1970 s. By levitating the "sensor" with a laser beam instead of adhering it to solid components, excellent environmental decoupling is achieved. Furthermore, unlike levitating particles in liquid or air, optical tweezers operating in vacuum are isolated from environmental thermal noise, thus eliminating the primary source of dissipation present for most inertial sensors. This attracted great attention in both fundamental and applied physics. In this paper we review the history and the basic concepts of optical tweezers in vacuum and provide an overall understanding of the field.