Stepped-up development of accelerator mass spectrometry method for the detection of ^(60)Fe with the HI-13 tandem accelerator

The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)Fe.In this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy degrader.For particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph.Finally,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS system.These results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)Ni.The sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.

Extracellular vesicles from iPSC-MSCs alleviate chemotherapy-induced mouse ovarian damage via the ILK-PI3K/AKT pathway

Chemotherapy can significantly reduce follicle counts in ovarian tissues and damage ovarian stroma,causing endocrine disorder,reproductive dysfunction,and primary ovarian insufficiency(POI).Recent studies have suggested that extracellular vesicles(EVs)secreted from mesenchymal stem cells(MSCs)exert therapeutic effects in various degenerative diseases.In this study,transplantation of EVs from human induced pluripotent stem cell-derived MSCs(iPSC-MSC-EVs)resulted in significant restoration of ovarian follicle numbers,improved granulosa cell proliferation,and inhibition of apoptosis in chemotherapy-damaged granulosa cells,cultured ovaries,and in vivo ovaries in mice.Mechanistically,treatment with i PSC-MSC-EVs resulted in up-regulation of the integrinlinked kinase(ILK)-PI3K/AKT pathway,which is suppressed during chemotherapy,most likely through the transfer of regulatory microRNAs(miRNAs)targeting ILK pathway genes.This work provides a framework for the development of advanced therapeutics to ameliorate ovarian damage and POI in female chemotherapy patients.

Factors influencing quality of life in Chinese patients with dementia: a systematic review

Background:Dementia is a group of nervous system diseases characterized by progressive cognitive decline,leading to a loss of self-care ability and a decline in well-being.This places a significant burden on the global healthcare system,with Chinese patients accounting for approximately one-quarter of the world’s dementia cases.Therefore,it is crucial to identify factors that impact the quality of life(QOL)among elderly Chinese individuals with dementia.Method:To achieve this,we conducted a comprehensive search of several databases,including PubMed,Embase,Web of Science,the Cochrane Library,China National Knowledge Infrastructure,Wanfang Data,China VIP Database and China Biomedical Literature Database.We reviewed cross-sectional studies from the inception of these databases until March 27,2022.QOL outcomes were assessed using standardized scales in the studies included in this review.Results:The search yielded a total of 1,235 relevant articles,from which we finally included 21 cross-sectional studies and one longitudinal study after rigorous quality assessment.Among these,10 studies were classified as high quality,while 12 were classified as fair quality.Through our analysis,we identified 28 patient-rated QOL factors and 14 caregiver-rated QOL factors.These factors were categorized into three groups:patient,disease-related and caregiver.Factors commonly found to influence patient-rated QOL included age,education,marital status,depression,self-care ability,dementia severity,cognitive function,behavioral and psychological symptoms of dementia and caregiver burden.Similarly,factors commonly influencing caregiver-rated QOL included economic status,depression,self-care ability,dementia severity,cognitive function,behavioral and psychological symptoms of dementia and caregiving time.Conclusion:This review clarifies the factors that influence the QOL of Chinese individuals with dementia.When implementing interventions,it is crucial to consider the differences between patient-rated QOL and caregiver-proxy-rated QOL,as well as their respective influencing factors.

Effect of SARS-CoV-2 infection on semen parameters in sperm bank volunteers with normal sperm concentration

In this study,we aimed to assess the effect of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection on semenparameters.The study comprised 110 sperm volunteers who self-reported SARS-CoV-2 infection from the Human Sperm Bank ofthe Center for Reproductive Medicine,Shandong University(Jinan,China).The volunteers had normal sperm concentration beforeinfection.Each volunteer provided semen samples before and after infection.We selected 90 days after infection as the cutoff point.Semen parameters within 90 days after infection of 109 volunteers(group A)were compared with semen parameters before infection.Moreover,semen parameters on or after 90 days after infection of 36 volunteers(group B)were compared with semen parameters beforeinfection.Furthermore,based on whether the volunteers had completed the three-dose SARS-CoV-2 vaccination booster,volunteersin group A and B were further divided into two subgroups separately.Semen parameters were compared before and after infection ineach subgroup.Our results showed that in this cohort population,the semen quality in volunteers with normal sperm concentrationsbefore infection decreased after SARS-CoV-2 infection within 90 days,while the semen quality returned to preinfection levels after 90days.The completion of a three-dose SARS-CoV-2 vaccination booster may exert a protective effect on semen quality after infection.

Macro and Micro Behaviors of Low Alloyed TRIP780 Steel with Different Biaxial Proportional Loading

To investigate the macro and micro behaviors of TRIP （transformation induced plasticity） steel under biaxial loading, experiment and finite element simulation were carried out for TRIP780 steel under proportional biaxial tension with displacement ratio of 1 ： 1, 2 ： 1, 3 ： 1 and 4 ： 1, respectively. The results show that cruciform specimens of TRIP780 steel fractured under proportional biaxial stretching when effective strain was about L 5 %, and fracture was always generated on the cross arm or cross links. During biaxial tension, stress and strain components in x and y directions of the center of the samples have the same nonlinear developing tendency, decreasing in one direction and increasing in another direction. Equal biaxial stretching stress state was helpful for retained austenite-martensite transformation than the other biaxial stress state. With increasing displacement ratio （DR） from 1 ： 1 to 4 ： 1, corresponding stress distributed unevenly on the yield ellipse from 30° to 60° in the first quadrant of stress space and corresponding retained austenite volume fraction distributed symmetrically in bow tie format.

Mutational analysis of the GATA4 gene in Chinese men with nonobstructive azoospermia

As a crucial transcription factor for spermatogenesis,GATA-binding protein 4(GATA4)plays important roles in the functioning of Sertoli and Leydig cells.Conditional knockout of GATA4 in mice results in age-dependent testicular atrophy and loss of fertility.However,whether GATA4 is associated with human azoospermia has not been reported.Herein,we analyzed the GATA4 gene by direct sequencing of samples obtained from 184 Chinese men with idiopathic nonobstructive azoospermia(NOA).We identified a missense mutation(c.191G>A,p.G64E),nine single-nucleotide polymorphisms(SNPs),and one rare variant(c.^(*)84C>T)in the 3′untranslated region(UTR).Functional studies demonstrated that the p.G64E mutation did not affect transactivation ability of GATA4 for spermatogenesis-related genes(claudin-11 and steroidogenic acute regulatory protein,Star),and the 3′UTR rare variant c.^(*)84C>T did not generate microRNA-binding sites to repress GATA4 expression.To our knowledge,this is the first report to investigate the association between GATA4 and azoospermia;our results indicate that mutations in GATA4 may not be pathogenic for NOA in Chinese men.