The Infiuence of Velocity-dependent Correction Factor on Proton Decay Reactions in Massive White Dwarfs

Twenty-five typical massive white dwarfs(WDs)are selected and the proton decay reaction catalyzed by magnetic monopoles(MMs)for these WDs is discussed.A velocity-dependent correction factor strongly affects the cross-section.We find that a strong suppression controls the monopole catalysis of nucleon decay by the correction factor.The maximum number of MMs is captured and the luminosity can be 2.235×10^(21)and 1.7859×10^(32)erg s^(-1)(e.g.,for the O+Ne core mass WD J055631.17+130639.78).The luminosities of most massive WDs agree well with the observations at relatively low temperatures(e.g.,T_(6)=0.1),but can be three and two orders of magnitude higher than those of the observations for model(Ⅰ)and(Ⅱ)at relatively high temperatures(e.g.,T_(6)=10),respectively.The luminosities of model(Ⅰ)are about one order of magnitude higher than those of model(Ⅱ).Since we consider the effect of the number of MMs captured on the mass–radius relation and the suppression of the proton decay by the correction factor,the study by model(Ⅱ)may be an improved estimation.

Predicting visual acuity with machine learning in treated ocular trauma patients

AIM:To predict best-corrected visual acuity(BCVA)by machine learning in patients with ocular trauma who were treated for at least 6mo.METHODS:The internal dataset consisted of 850 patients with 1589 eyes and an average age of 44.29y.The initial visual acuity was 0.99 log MAR.The test dataset consisted of 60 patients with 100 eyes collected while the model was optimized.Four different machine-learning algorithms(Extreme Gradient Boosting,support vector regression,Bayesian ridge,and random forest regressor)were used to predict BCVA,and four algorithms(Extreme Gradient Boosting,support vector machine,logistic regression,and random forest classifier)were used to classify BCVA in patients with ocular trauma after treatment for 6mo or longer.Clinical features were obtained from outpatient records,and ocular parameters were extracted from optical coherence tomography images and fundus photographs.These features were put into different machine-learning models,and the obtained predicted values were compared with the actual BCVA values.The best-performing model and the best variable selected were further evaluated in the test dataset.RESULTS:There was a significant correlation between the predicted and actual values[all Pearson correlation coefficient(PCC)>0.6].Considering only the data from the traumatic group(group A)into account,the lowest mean absolute error(MAE)and root mean square error(RMSE)were 0.30 and 0.40 log MAR,respectively.In the traumatic and healthy groups(group B),the lowest MAE and RMSE were 0.20 and 0.33 log MAR,respectively.The sensitivity was always higher than the specificity in group A,in contrast to the results in group B.The classification accuracy and precision were above 0.80 in both groups.The MAE,RMSE,and PCC of the test dataset were 0.20,0.29,and 0.96,respectively.The sensitivity,precision,specificity,and accuracy of the test dataset were 0.83,0.92,0.95,and 0.90,respectively.CONCLUSION:Predicting BCVA using machine-learning models in patients with treated ocular trauma is accurate and helpful in the identification of visual dysfunction.

多焦点人工晶状体植入的研究进展

白内障是导致患者视力下降乃至失明的主要原因之一,手术是治疗白内障确切有效的手段。随着科学技术的进步,传统的复明性白内障手术逐渐过渡到屈光性白内障手术。各种屈光性人工晶状体也应运而生,传统的单焦点人工晶状体(single focus intraocular lens, SIOL)不再是患者的唯一选择,多焦点人工晶状体(multifocal intraocular lens, MIOL)越来越被患者接受和认可。本文对现有的多焦点人工晶状体进行了归纳总结,通过分类列举,简述不同类型多焦点人工晶状体的多种特点及评估患者术后临床效果的方法,以期为眼科医生提供参考。

The association between the baseline bone resorption marker CTX and incident dysglycemia after 4 years

Bone is an endocrine organ involved in modulating glucose homeostasis. The role of the bone formation marker osteocalcin （OCN） in predicting diabetes was reported, but with conflicting results. No study has explored the association between baseline bone resorption activity and incident diabetes or prediabetes during follow-up. Our objective was to examine the relationship between the baseline bone resorption marker crosslinked C-telopeptide of type I collagen （CTX） and glycemic dysregulation after 4 years. This longitudinal study was conducted in a university teaching hospital. A total of 195 normal glucose tolerant （NGT） women at baseline were invited for follow-up. The incidence of diabetes and prediabetes （collectively defined as dysglycemia） was recorded. A total of 128 individuals completed the 4-year study. The overall conversion rate from NGT to dysglycemia was 31.3%. The incidence of dysglycemia was lowest in the middle tertile [16.3% （95% confidence interval （CI）, 6.8%-30.70/0）] compared with the lower [31.0% （95% CI, 17.2%-46.1%）] and upper [46.5% （95% CI, 31.2%-62.6%）] tertiles of CTX, with a significant difference seen between the middle and upper tertiles （P = 0.002 5）. After adjusting for multiple confounding variables, the upper tertile of baseline CTX was associated with an increased risk of incident dysglycemia, with an odds ratio of 7.09 （95% CI, 1.73-28.99） when the middle tertile was the reference. Osteoclasts actively regulate glucose homeostasis in a biphasic model that moderately enhanced bone resorption marker CTX at baseline provides protective effects against the deterioration of glucose metabolism, whereas an overactive osteoclastic function contributes to an increased risk of subsequent dysglycemia.

Kinetics of discontinuous precipitation in Cu–20Ni–20Mn alloy

The morphology and growth kinetics of discontinuous precipitation （DP） in a Cu-20Ni-20Mn alloy were investigated in the tem- perature range of523-573 K by optical microscopy, scanning electron microscopy, and transmission electron microscopy. A lamellar mixed structure consisting of alternating larnellae of a matrix and NiMn phase was observed in DP colonies. The volume fraction of regions formed by a DP reaction was determined by quantitative metallographic measurements. The kinetics of DP was evaluated on the basis of the John- son-MehI-Avrami Kohnogorov equation, which resulted in a time exponent of approximately 1.5. We confirmed that the nucleation of the discontinuous precipitate was confined to grain edges or boundaries at an early stage of the reaction. The activation energy of DP process was determined to be approximately （72.7 ± 7.2） kJ/mol based on the Arrhenius equation; this result suggests that DP is controlled by gn-ain boundary diffusion. The hardness values exhibited good correlation with the volume fraction of DP; this correlation was attributed to the plvsence of the ordered N iMn phase.

Strongly screened electron capture rates of chromium isotopes in presupernova evolution

Taking into account the effect of electron screening on electron energy and electron capture threshold energy, by using the method of Shell-Model Monte Carlo and random phase approximation theory, we investigate the capture rates of chromium isotopes with strong electron screening according to the linear response theory screening model. Strong screening rates can decrease by about 40.43% （e.g., for 6Cr at T9 = 3.44, Ye = 0.43）. Our conclusions may be helpful to researches on supernova explosions and related numerical simulation methods.

Dementia-related contact experience,attitudes,and the level of knowledge in medical vocational college students

BACKGROUND Dementia is a severe neurological and psychological disease that occurs in older adults worldwide.The knowledge and attitude of medical-vocational college students play an important role in supporting primary healthcare systems.AIM To investigate the level of knowledge,contact experience,and attitudes toward dementia among medical-vocational college students in China.METHODS A cross-sectional survey was conducted,and 3-year medical and medical-related students from eight vocational colleges in Anhui province were recruited.The contact experience,attitudes,and knowledge level of students toward dementia were assessed using a questionnaire designed according to the Chinese version of the Alzheimer’s Disease Knowledge Scale(ADKS).RESULTS A total of 2444 medical and medical-related students completed the survey,of whom 86.7% of respondents had interests and concerns regarding Alzheimer’s disease(AD),and 29.2% of respondents had experiences of contact with dementia patients.Overall attitudes toward dementia were negative.Only 35.4% of students were interested in participating in the caregiving of dementia patients.The mean score of students’ knowledge about AD as assessed by the ADKS was 21.16(standard deviation,3.43) out of 30.CONCLUSION Dementia-related knowledge of medical-vocational college students was at a medium level,and their overall attitudes toward dementia were negative.

Beta decay of nuclides ^(56)Fe,^(62)Ni,^(64)Ni and ^(68)Ni in the crust of magnetars

By introducing the Dirac δ-function and Pauli exclusion principle in the presence of superstrong magnetic fields （SMFs）, we investigate the influence of SMFs on beta decay and the change rates of electron fraction （CREF） of nuclides 56Fe, 62Ni, 64Ni and 6SNi in magnetars, which are powered by magnetic field energy. We find that the magnetic fields have a great influence on the beta decay rates, and the beta decay rates can decrease by more than six orders of magnitude in the presence of SMFs. The CREF also decreases by more than seven orders of magnitude in the presence of SMFs.

Supernova β^- decay of nuclides ^(53)Fe,^(54)Fe,^(55)Fe and ^(56)Fe in strongly screened plasma

Electron screening has strong effects on electron energy and threshold energy of the beta decay reaction.In this paper,we study β~-decay rates of some iron isotopes.The beta decay rates increase by about two orders of magnitude due to electron screening.Strongly screened beta decay rates due to Q-value correction are more than one order of magnitude higher than those without Q-value correction.

Iron group nuclei electron capture in super-Chandrasekhar superstrong magnetic white dwarfs

Using the theory of relativistic mean-field effective interactions,the influences of superstrong magnetic fields(SMFs)on electron Fermi energy,binding energy per nucleus and single-particle level structure are discussed in super-Chandrasekhar magnetic white dwarfs.Based on the relativistical SMFs theory model of Potekhin et al.,the electron chemical potential is corrected in SMFs,and the electron capture(EC)of iron group nuclei is investigated by using the Shell-Model Monte Carlo method and Random Phase Approximation theory.The EC rates can increase by more than three orders of magnitude due to the increase of the electron Fermi energy and the change of single-particle level structure by SMFs.However,the EC rates can decrease by more than four orders of magnitude due to increase of the nuclei binding energy by SMFs.We compare our results with those of FFNs(Fuller et al.),AUFDs(Aufderheide et al.)and Nabi(Nabi et al.).Our rates are higher by about four orders of magnitude than those of FFN,AUFD and Nabi due to SMFs.Our study may have important reference value for subsequent studies of the instability,mass radius relationship,and thermal and magnetic evolution of super-Chandrasekhar magnetic white dwarfs.

Microstructure and physical properties of Cu-2.3Ni-0.5Si alloy with thermo-mechanical treatment

For Cu-Ni-Si alloys,cold rolling is usually performed after solution treatment to enhance physical properties such as strength and electrical conductivity during the aging process.This paper reports the variation in microstructure and physical properties during the aging process of Cu-2.3Ni-0.5Si alloy cold-rolled at room temperature(RT) and cryogenic temperature(CT).When aged at 450℃ for 2 h,RT-rolled samples exhibited a maximum hardness of HV5234 with an electric conductivity of 39.9% IACS.For CTrolled samples,the peak hardness was achieved when the samples were aged at 450% for 1 h.

New insights into the limit of the magnetic monopole flux and the heatingsource in white dwarfs

Based on the magnetic monopole(MM)catalytic nuclear decay(Rubakov-Callan(RC)effect),we propose five new models to discuss the limit of the MM flux and the heating energy resources of white dwarfs(WDs)based on observations of 13 red giant branch(RGB)stars.We find that the number of MMs captured can reach a maximum value of 9.1223×10^(24)when m=10^(17)GeV,nB=5.99×10^(31)cm^(-3),Φ=7.59×10^(-26)cm^(-2)s^(-1)sr^(-1).The good agreement of our calculated luminosities for WDs with observation provides support for our model based on the RC effect by MMs.We obtain a new limit of the MM flux of ξ=Φ(σ_(m)^(v)T)_(-28)≤9.0935×10^(-13)cm^(-2)s^(-1)sr^(-1),and≤4.9950×10^(-13)cm^(-2)s^(-1)sr^(-1)at nB=5.99×1031cm-3 when m=1015GeV,β=9.4868×10^(-3),and m=1017Gev,β=10^(-3),respectively.Our results show that the RC effect could cause heating that prevents white dwarfs from cooling down into a stellar graveyard.Our results will also provide a new idea for further research on the upper limit of MM flow(note:nB,σ_(m),m,φ,ξ,are the baryon number density,reaction cross section,mass,MM flux,and the new limit of the MM flux,respectively,andβ=v_(T/C)is the ratio of the speed of MMs to that of light).

Fetal Hemodynamics and Fetal Growth Indices by Ultrasound in Late Pregnancy and Birth Weight in Gestational Diabetes Mellitus

Background： The offspring of women with gestational diabetes mellitus （GDM） are prone to macrosomia. However, birth weight is difficult to be correctly estimated by ultrasound because of fetal asymmetric growth characteristics. This study aimed to investigate the correlations between fetal hemodynamics, fetal growth indices in late pregnancy, and birth weight in GDM. Methods： A total of 147 women with GDM and 124 normal controls （NC） were enrolled in this study. Fetal hemodynamic indices, including the systolic/diastolic ratio （S/D）, resistance index （RI）, pulsatility index （PI） of umbilical artery （UA）, middle cerebral artery （MCA）, and renal artery （RA）, were collected. Fetal growth indices, including biparietal diameter （BPD）, head circumference （HC）, abdominal circumference （AC）, and femur length, were also measured by ultrasound. Birth weight, newborn gender, and maternal clinical data were collected. Results： The independent samples t-test showed that BPD, HC, and AC were larger in GDM than in NC （P 〈 0.05）. Fetal hemodynamic indices of the UA and MCA were lower （P 〈 0.05）, but those of the RA were higher （P 〈 0.001 ） in GDM than in NC. Birth weight was higher in GDM than in NC （P 〈 0.001）. Pearson＇s correlation analysis showed that hemodynamic indices of the UA were negatively correlated with birth weight, BPD, HC, and AC in both groups （P 〈 0.05）. MCA （S/D, PI, and RI） was negatively correlated with birth weight, HC, and AC in GDM （i- = -0.164, -0.206, -0.200, -0.226, -0.189, -0.179, -0.196, -0.177, and - 0.172, respectively, P 〈 0.05）, but there were no correlations in NC （P 〉 0.05）. RA （S/D, PI, and RI） was positively correlated with birth weight in GDM （r = 0.168, 0.207, and 0.184, respectively, P 〈 0.05）, but there were no correlations in NC （P 〉 0.05）. Conclusion： Fetal hemodynamic indices in late pregnancy might be helpful for estimating newborn birth weight in women with GDM.

Species diversity of Basidiomycota

Fungi are eukaryotes that play essential roles in ecosystems.Among fungi,Basidiomycota is one of the major phyla with more than 40,000 described species.We review species diversity of Basidiomycota from five groups with different lifestyles or habitats:saprobic in grass/forest litter,wood-decaying,yeast-like,ectomycorrhizal,and plant parasitic.Case studies of Agaricus,Cantharellus,Ganoderma,Gyroporus,Russula,Tricholoma,and groups of lichenicolous yeast-like fungi,rust fungi,and smut fungi are used to determine trends in discovery of biodiversity.In each case study,the number of new species published during 2009–2020 is analysed to determine the rate of discovery.Publication rates differ between taxa and reflect different states of progress for species discovery in different genera.The results showed that lichenicolous yeast-like taxa had the highest publication rate for new species in the past two decades,and it is likely this trend will continue in the next decade.The species discovery rate of plant parasitic basidiomycetes was low in the past ten years,and remained constant in the past 50 years.We also found that the establishment of comprehensive and robust taxonomic systems based on a joint global initiative by mycologists could promote and standardize the recognition of taxa.We estimated that more than 54,000 species of Basidiomycota will be discovered by 2030,and estimate a total of 1.4–4.2 million species of Basidiomycota glob-ally.These numbers illustrate a huge gap between the described and yet unknown diversity in Basidiomycota.

PPARγ2 functions as a tumor suppressor in a translational mouse model of human prostate cancer

Peroxisome proliferator-activated receptorsγ(PPARγ)is a master regulator that controls energy metabolism and cell fate.PPARγ2,a PPARγisoform,is highly expressed in the normal prostate but expressed at lower levels in prostate cancer tissues.In the present study,PC3 and LNCaP cells were used to examine the benefits of restoring PPARγ2 activity.PPARγ2 was overexpressed in PC3 and LNCaP cells,and cell proliferation and migration were detected.Hematoxylin and eosin(H&E)staining was used to detect pathological changes.The genes regulated by PPARγ2 overexpression were detected by microarray analysis.The restoration of PPARγ2 in PC3 and LNCaP cells inhibited cell proliferation and migration.PC3-PPARγ2 tissue recombinants showed necrosis in cancerous regions and leukocyte infiltration in the surrounding stroma by H&E staining.We found higher mixed lineage kinase domain-like(MLKL)and lower microtubule-associated protein 1 light chain 3(LC3)expression in cancer tissues compared to controls by immunohistochemistry(IHC)staining.Microarray analysis showed that PPARγ2 gain of function in PC3 cells resulted in the reprogramming of lipid-and energy metabolism-associated signaling pathways.These data indicate that PPARγ2 exerts a crucial tumor-suppressive effect by triggering necrosis and an inflammatory reaction in human prostate cancer.

Delimiting species in Basidiomycota:a review

Species delimitation is one of the most fundamental processes in biology.Biodiversity undertakings,for instance,require explicit species concepts and criteria for species delimitation in order to be relevant and translatable.However,a perfect species concept does not exist for Fungi.Here,we review the species concepts commonly used in Basidiomycota,the second largest phylum of Fungi that contains some of the best known species of mushrooms,rusts,smuts,and jelly fungi.In general,best practice is to delimitate species,publish new taxa,and conduct taxonomic revisions based on as many independent lines of evidence as possible,that is,by applying a so-called unifying(or integrative)conceptual framework.However,the types of data used vary considerably from group to group.For this reason we discuss the different classes of Basidiomycota,and for each provide:(i)a general introduction with difficulties faced in species recognition,(ii)species concepts and methods for species delimitation,and(iii)community recommendations and conclusions.

Factors influencing the formation of chlorination brominated trihalomethanes in drinking water

The formation of brominated trihalomethanes (THMs-Br) which is proved more carcinogenic than their chlorinated analogues reported was very different at various water qualities.This study was performed to assess the effects of water quality parameters (bromide concentration,pH value and ammonia concentration),chlorination conditions (chlorine dose,reaction time) and ratios of Br-/DOC and Br-/Cl2 consumption on the formation and distribution of THMs-Br in chlorination.The results showed good correlation between the bromine incorporation factor (BIF) n(Br) and Br-/Cl2 consumption ratio.The formation of total THM (TTHM) was found to decrease with increasing ammonia concentration but to increase with bromide concentration and pH value.The n(Br) trends were significantly affected by the presence of bromide concentration.The effects on the molar yields of THMs were more strongly influenced by bromide concentration and dissolved organic carbon (DOC) concentration than pH value and natural organic matter (NOM) source.High Br-/DOC and Br-/Cl2 favor the formation of THMs-Br over chlorinated THMs (THMs-Cl).The experimental data including the main parameters such as bromide,DOC,ammonia,pH and reaction time were used for developing the predictive model for THMs-Br.

Strongly screening β^- decay antineutrino energy loss in presupernova

In this study, we investigate the ion-ball screening model(model(I)), focused on the screening electrostatic potential per electron under the Wigner-Seitz approximation and the Q-value correction. By considering the changes of the Coulomb free energy and the effects of strong electron screening(SES) on the Q-value and the Coulomb chemical potential, we discuss the linear-response screening model(model(Ⅱ)). We also analyze the influence of the SES on the β^- decay antineutrino energy loss rate by considering the corrections of the Q-value, the electron chemical potential, and electron energy, as well as the shell and pair effects. The antineutrino energy loss rate is found to increase by two orders of magnitude(e.g., the SES enhancement factor reaches 651.9 for model(Ⅱ)) due to the SES effect.

Fluvastatin and the Breast Cancer Risk:A Meta-analysis of Observational Studies

Multiple studies have investigated the associations between fluvatatin and the risk of breast cancer(BC),but their results were conflicting.A meta-analysis of observational studies published regarding this subject was conducted in the present study.It aims to estimate the associations between fluvastatin use and the risk of BC.Pubmed and chinese national knowledge infrastructure(CNKI) database was searched up to January,2015 to identify eligible observational studies,and the Newcastle-Ottawa Scale(NOS) was used to assess quality of the studies.Pooled relative risk(RR) estimates and 95% confidence intervals(CIs) were calculated(fixed effect model:Mantel-Haenszel).Heterogeneities were evaluated before the calculation.A sensitivity analysis was also conducted.In total,four studies contributed to the analysis.Overall,fluvastatin use negatively correlated with BC risk(RR = 0.74,95 % CI = 0.58,0.95).In conclusion,fluvastatin use may reduce the risk of BC,but more research is needed to confirm this finding.