纤维素/二氧化钛复合纳米纤维膜的制备及对Cu^(2+)吸附性能

采用静电纺丝技术与水解后处理的方法相结合,制备了纤维素/TiO_2复合纳米纤维膜。通过扫描电镜、红外光谱、X射线衍射、接触角及力学性能测试对复合纳米纤维膜进行了表征。结果表明,复合纳米纤维膜表面光滑,纤维呈三维杂乱排列;加入TiO_2后,纳米纤维的平均直径略有下降,纤维素的结晶度减小,断裂强度降低;但亲水性大幅提升。Cu^(2+)吸附试验结果表明,溶液pH、Cu^(2+)初始浓度和吸附时间是影响吸附效果的重要因素,Cu^(2+)的最大平衡吸附量可达66.54mg/g。Cu^(2+)在纤维素/TiO_2复合纳米纤维膜上的等温吸附规律可以用Langmuir和Freundlich吸附等温模型进行描述,从相关系数来看,纤维素/TiO_2复合纳米纤维对Cu^(2+)的吸附行为用Freundlich模型描述更为合理。

经尿道前列腺等离子双极电切术与剜除术治疗良性前列腺增生的有效性和安全性的系统评价和Meta分析

目的评估经尿道前列腺等离子双极电切术(TUPKP)与剜除术(TUPEP)治疗良性前列腺增生(BPH)的有效性与安全性。方法计算机检索PubMed、Embase、Web of Science、The Cochrane Library、中国知网、维普、中国生物医学文献数据库及万方数据库中相关的随机对照试验,检索至2020年9月15日,同时手动检索参考文献。由两名研究者独立进行文献筛选、资料提取与质量评价。采用Stata 13.0软件进行Meta分析。结果共纳入30项研究,包括3218例BPH患者,其中1626例接受TUPKP,1592例接受TUPEP。Meta分析结果显示:有效性方面治疗普通体积(<80 mL)前列腺时,TUPKP组比TUPEP组切除组织量更少,但术后6、12个月的残余尿量(PVR)更多,术后3、6个月的国际勃起功能指数-5(IIEF-5)更低,差异有统计学意义(P<0.05);术后1、3、6、12个月的国际前列腺症状评分(IPSS)、最大尿流率(Q_(max))、生活质量(QoL)及术后1、3个月的PVR在两组间无统计学差异(P>0.05)。治疗大体积(≥80 mL)前列腺时,相较于TUPEP组,TUPKP组切除组织量更少,但术后6个月的IPSS更高,3个月的Q_(max)更小且PVR更多,差异有统计学意义(P<0.05);术后1、3个月的IPSS,术后1、6个月的Q_(max),术后1、3、6个月的QoL,术后6个月的PVR和IIEF-5在两组间无统计学差异(P>0.05)。安全性方面治疗普通体积前列腺时,相较于TUPEP组,TUPKP组手术时间、住院时间、术后导尿管留置时间、膀胱冲洗时间更长,术中出血量更多,发生包膜穿孔、膀胱痉挛的风险更高,差异有统计学意义(P<0.05);尿道狭窄、暂时性尿失禁、逆行射精、尿潴留、尿路感染的风险在两组间无统计学差异(P>0.05)。治疗大体积前列腺时,与TUPEP组相比,TUPKP组手术时间、住院时间、术后导尿管留置时间、膀胱冲洗时间更长,差异有统计学意义(P<0.05);术中出血量,以及发生包膜穿孔、尿道狭窄、暂时性尿失禁、逆行射精、膀胱痉挛、尿潴留、尿路感染的风险在两组间无统计学差异(P>0.05)。结论对于普通体积和大体积BPH患者,TUPKP和TUPEP的有效性整体相当,但TUPEP在安全性方面优于TUPKP。

Epidemiological trends of urinary tract infections,urolithiasis and benign prostatic hyperplasia in 203 countries and territories from 1990 to 2019

Background:Urinary tract infections(UTI),urolithiasis,and benign prostatic hyperplasia(BPH)are three of the most common nonmalignant conditions in urology.However,there is still a lack of comprehensive and updated epidemiological data.This study aimed to investigate the disease burden of UTI,urolithiasis,and BPH in 203 countries and territories from 1990 to 2019.Methods:Data were extracted from the Global Burden of Disease 2019,including incident cases,deaths,disabilityadjusted life-years(DALYs)and corresponding age-standardized rate(ASR)from 1990 to 2019.Estimated annual percentage changes(EAPC)were calculated to evaluate the trends of ASR.The associations between disease burden and social development degrees were analyzed using a sociodemographic index(SDI).Results:Compared with 1990,the incident cases of UTI,urolithiasis,and BPH increased by 60.40%,48.57%,and 105.70%in 2019,respectively.The age-standardized incidence rate(ASIR)of UTI increased(EAPC=0.08),while urolithiasis(EAPC=–0.83)and BPH(EAPC=–0.03)decreased from 1990 to 2019.In 2019,the age-standardized mortality rate(ASMR)of UTI and urolithiasis were 3.13/100,000 and 0.17/100,000,respectively.BPH had the largest increase(110.56%)in DALYs in the past three decades,followed by UTI(68.89%)and urolithiasis(16.95%).The burden of UTI was mainly concentrated in South Asia and Tropical Latin America,while the burden of urolithiasis and BPH was recorded in Asia and Eastern Europe.Moreover,the ASIR and SDI of urolithiasis in high-SDI regions from 1990to 2019 were negatively correlated,while the opposite trend was seen in low-SDI regions.In 2019,the ASIR of UTI in females was 3.59 times that of males,while the ASIR of urolithiasis in males was 1.96 times higher than that in females.The incidence was highest in the 30–34,55–59,and 65–69 age groups among the UTI,urolithiasis,and BPH groups,respectively.Conclusions:Over the past three decades,the disease burden has increased for UTI but decreased for urolithiasis and BPH.The allocation of medical resources should be based more on the epidemiological characteristics and geographical distribution of diseases.

Anisotropy of mechanical properties of 2297-T87 Al–Li alloy thick plates

The tensile properties of 2297-T87 Al–Li alloy thick plates at different thickness position and in different direction were analyzed via tensile testing,optical microscopy(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectrometry(EDS),and transmission electron microscopy(TEM).Results indicated that the ultimate tensile strength(UTS)and yield strength(YS)of the alloy decreased firstly and then increased from the 1/8T position to the 1/2T position,whereas elongation to failure(Ef)decreased gradually such that its value along the rolling direction(RD)was higher than those along the transverse direction(TD)at the same thickness position.From the 1/8T position to the 3/8T position of the alloy,the UTS and YS along the TD were higher than those along the RD.At the 1/2T position of the alloy,the UTS,YS,and Ef along the RD were the highest,whereas those along the normal direction(ND)were the lowest.Microstructural observations further revealed that the anisotropy of tensile properties was related to grain morphology,crystal texture,second-phase particles,and Li atom segregation.

Global,regional,and national burden of kidney,bladder,and prostate cancers and their attributable risk factors,1990–2019

Background:The burden of kidney,bladder,and prostate cancers has changed in recent decades.This study aims to investigate the global and regional burden of,and attributable risk factors for genitourinary cancers during the past 30 years.Methods:We extracted data of kidney,bladder,and prostate cancers from the Global Burden of Disease 2019 database,including incidence,mortality,disability-adjusted life-years(DALYs),and attributable risk factors from 1990 to 2019.Estimated annual percentage changes(EAPC)were calculated to assess the changes in age-standardized incidence rate,age-standardized mortality rate(ASMR),and age-standardized DALYs rate(ASDR).The associations between cancers burden and socio-demographic index(SDI)were also analyzed.Results:Compared with 1990,the global incident cases in 2019 were higher by 154.78%,123.34%,and 169.11%for kidney,bladder,and prostate cancers,respectively.During the 30-year study period,there was a downward trend in ASMR and ASDR for bladder cancer(EAPC=–0.68 and–0.83,respectively)and prostate cancer(EAPC=–0.75 and–0.71,respectively),but an upward trend for kidney cancer(EAPC=0.35 and 0.12,respectively).Regions and countries with higher SDI had higher incidence,mortality,and DALYs for all three types of cancers.The burden of bladder and prostate cancers was mainly distributed among older men,whereas the burden of kidney cancer increased among middle-aged men.Smoking related mortality and DALYs decreased,but high body mass index(BMI)and high fasting plasma glucose(FPG)related mortality and DALYs increased among kidney,bladder,and prostate cancers during the study period.Conclusions:Kidney,bladder,and prostate cancers remain major global public health challenges,but with distinct trend for different disease entity across different regions and socioeconomic status.More proactive intervention strategies,at both the administrative and academic levels,based on the dynamic changes,are needed.

Theoretical Predictions on Superconducting Phase above Room Temperature in Lutetium-Beryllium Hydrides at High Pressures

High-pressure structural search was performed on the hydrogen-rich compound LuBeH8at pressures up to 200 GPa.We found an Fm3m structure that exhibits stability and superconductivity above 100 GPa.Our phonon dispersion,electronic band structure,and superconductivity analyses in the 100–200 GPa pressure range reveal a strong electron–phonon coupling in Lu Be H8,while the superconducting critical temperature Tcshows a decreasing trend as the pressure increases,with T_(c)=255 K at 200 GPa and maximal T_(c)=355 K at 100 GPa.This study demonstrated the room-temperature superconductivity in Fm3m thus enriching the family of ternary hydrides.These findings provide valuable guidance for identifying new high-temperature superconducting hydrides.

牛樟芝免疫调节蛋白的过量表达及活性分析

【目的】用大肠杆菌高效表达牛樟芝免疫调节蛋白(Antrodia camphorata immunomodulatory protein,ACA)。【方法】借助DNAworks3.2.4设计引物合成大肠杆菌密码子偏好性的ACA基因,构建于pET-32a和pGEX-4t-2,转化大肠杆菌,测序后分别命名为pET-32a-ACA/BL21和pGEX-4t-2-ACA/BL21;探索密码子偏好性、载体、培养基种类和诱导条件对ACA表达的影响并使用响应面法优化蛋白表达。纯化重组ACA(recombinant ACA,rACA)并干预小鼠巨噬细胞RAW264.7,通过测定rACA对巨噬细胞增殖能力、吞噬能力、细胞形态及产NO、肿瘤坏死因子α(tumor necrosis factor-α,TNFα)、白介素lβ(interleukin-1β,IL-1β)等细胞因子能力的影响来评估rACA的活性。【结果】pET-32a-ACA/BL21更适合ACA表达;在优化的SOB(酵母粉8.92 g/L)中培养pET-32a-ACA/BL21,添加0.42 mmol/L IPTG 25℃诱导7 h时rACA以可溶性表达为主,产量达187.122μg/mL,是目前大肠杆菌表达真菌免疫调节蛋白的最高报道。纯化的rACA能显著促进小鼠巨噬细胞增殖、提高细胞的吞噬活性和改变细胞形态,显著诱导巨噬细胞分泌NO、TNF-α和IL-1β。【结论】rACA的高效可溶性表达及类似天然ACA的活性使它可以替代天然ACA作为制药行业的食品添加剂或者免疫调节剂,甚至可以用于药物研究。

Accurate and explainable machine learning for the power factors of diamond-like thermoelectric materials

The application of machine learning(ML)-based methods to the study of thermoelectric(TE)materials is promising.Although conventional ML algorithms can achieve high prediction performance,their lack of interpretability severely obstructs researchers from extracting material-oriented insights from ML models.In this work,high ML-based prediction performance was achieved with respect to TE power factors(PFs),and the results were well understood by the SHapley Additive exPlanations(SHAP),a method to identify the correlations between targets and descriptors.We designed a robust PF prediction model for diamond-like compounds via a stacking technique,and the model achieved a coefficient of determination value above 0.95 on the test set.From the SHAP analysis,the PFs were negatively correlated with electronegativity and positively correlated with the descriptor“volume per atom”based on the previously reported dataset.TE domain knowledge was adopted to understand these correlations.This work shows that ML models can achieve high accuracy while exhibiting good interpretability,making them useful for materials scientists.