华北克拉通中元古代A型花岗岩的成因及其构造意义

华北克拉通保存有与Columbia超大陆裂解相关的中元古代岩浆记录。本文综述了华北克拉通中元古代A型花岗岩的时空分布、岩石学和地球化学等特征,讨论了各期次A型花岗岩的成因及构造背景,论述了其对华北克拉通中元古代裂解事件的指示意义。华北克拉通主要发育4期A型花岗岩:1)~1.78 Ga A型花岗岩主要分布于南缘熊耳裂陷槽和晋陕地区;2)~1.70 Ga A型花岗岩主要分布于北缘渣尔泰—白云鄂博和燕辽裂陷槽;3)~1.60 Ga A型花岗岩主要分布于南缘熊耳裂陷槽;4)~1.32 Ga A型花岗岩主要分布于北缘渣尔泰—白云鄂博和燕辽裂陷槽。这4期A型花岗岩均来源于地壳物质的部分熔融,可能与同期伸展作用导致岩浆底侵提供热源有关。整体具有造山后伸展到陆内裂谷环境的演化序列,且存在明显的时空差异。华北克拉通中元古代A型花岗岩记录了4期主要的裂解事件,为华北克拉通参与了Columbia超大陆裂解提供了依据。

Recent advances in two-dimensional photovoltaic devices

Two-dimensional(2D)materials have attracted tremendous interest in view of the outstanding optoelectronic properties,showing new possibilities for future photovoltaic devices toward high performance,high specific power and flexibility.In recent years,substantial works have focused on 2D photovoltaic devices,and great progress has been achieved.Here,we present the review of recent advances in 2D photovoltaic devices,focusing on 2D-material-based Schottky junctions,homojunctions,2D−2D heterojunctions,2D−3D heterojunctions,and bulk photovoltaic effect devices.Furthermore,advanced strategies for improving the photovoltaic performances are demonstrated in detail.Finally,conclusions and outlooks are delivered,providing a guideline for the further development of 2D photovoltaic devices.

Safety assessment of a novel marine multi-stress-tolerant yeast Meyerozyma guilliermondii GXDK6 according to phenotype and whole genome-sequencing analysis

The application of microorganisms as probiotics is limited due to lack of safety evaluation.Here,a novel multi-stress-tolerant yeast Meyerozyma guilliermondii GXDK6 with aroma-producing properties was identified from marine mangrove microorganisms.Its safety and probiotic properties were assessed in accordance with phenotype and whole-genome sequencing analysis.Results showed that the genes and phenotypic expression of related virulence,antibiotic resistance and retroelement were rarely found.Hyphal morphogenesis genes(SIT4,HOG1,SPA2,ERK1,ICL1,CST20,HSP104,TPS1,and RHO1)and phospholipase secretion gene(VPS4)were annotated.True hyphae and phospholipase were absent.Only one retroelement(Tad1-65_BG)was found.Major biogenic amines(BAs)encoding genes were absent,except for spermidine synthase(JA9_002594),spermine synthase(JA9_004690),and tyrosine decarboxylase(inx).The production of single BAs and total BAs was far below the food-defined thresholds.GXDK6 had no resistance to common antifungal drugs.Virulence enzymes,such as gelatinase,DNase,hemolytic,lecithinase,and thrombin were absent.Acute toxicity test with mice demonstrated that GXDK6 is safe.GXDK6 has a good reproduction ability in the simulation gastrointestinal tract.GXDK6 also has a strong antioxidant ability,β-glucosidase,and inulinase activity.To sum up,GXDK6 is considered as a safe probiotic for human consumption and food fermentation.

The In-Flight Realtime Trigger and Localization Software of GECAM

Realtime trigger and localization of bursts are the key functions of GECAM,an all-sky gamma-ray monitor launched on 2020 December 10.We developed a multifunctional trigger and localization software operating in the CPU of the GECAM Electronic Box.This onboard software has the following features:high trigger efficiency for real celestial bursts with a suppression of false triggers caused by charged particle bursts and background fluctuation,dedicated localization algorithm optimized for both short and long bursts,and low time latency of the trigger information which is downlinked through the Global Short Message Communication service of the global BeiDou navigation system.This paper provides a detailed description of the design and development of the trigger and localization software system for GECAM.It covers the general design,workflow,the main functions,and the algorithms used in the system.The paper also includes on-ground trigger tests using simulated gamma-ray bursts generated by a dedicated X-ray tube,as well as an overview of the performance for real celestial bursts during its in-orbit operation.

龟鹿二仙胶通过Keap1/Nrf2通路抑制自噬、减轻小鼠GC-1精原细胞氧化损伤

目的:探讨龟鹿二仙胶(Guilu Erxian glue,GLEXG)对氧化损伤小鼠GC-1精原(mouse GC-1 spermatogonial,MGS)细胞模型的影响及潜在作用机制。方法:过氧化氢(H_(2)O_(2))处理MGS细胞构建氧化损伤细胞模型。通过细胞计数试剂盒-8测定法评估细胞活力。运用流式细胞术和酶联免疫吸附测定分别检测活性氧(ROS)和丙二醛(MDA)水平。通过蛋白印迹和免疫荧光测定sequestosome-1(p62)、核因子红细胞相关因子2(Nrf2)、微管相关蛋白轻链3β(LC3B)和Kelch样ECH相关蛋白1(Keap1)的表达。通过实时定量聚合酶链反应评估Keap1相对mRNA的表达。通过透射电子显微镜(TEM)观察自噬相关囊泡的结构变化。结果:H_(2)O_(2)诱导的氧化损伤细胞模型表现出细胞活力下降,ROS和MDA水平升高。10%浓度GLEXG含药血清治疗后细胞活力显著上升(P=0.0002),ROS和MDA水平显著下降(P=0.0105和P=0.0033)。在雷帕霉素处理的MGS细胞中,GLEXG治疗可显著上调p-mTOR、Nrf2和p62蛋白表达(均P<0.01),下调Keap1蛋白表达和LC3B-II/LC3B-1比值(P=0.002和P=0.0043),并可降低细胞内ROS和MDA水平。TEM分析显示GLEXG治疗显著减少雷帕霉素处理的MGS细胞中异常增大的自溶体数量。在Keap1-siRNA转染的MGS细胞中,siRNA-Keap1-2311敲除位点显示出更高的效率。此外,在这些Keap1-siRNA转染的细胞中,GLEXG治疗可显著上调Nrf2和p62的蛋白表达,下调Keap1蛋白表达和LC3B-II/LC3B-I比值,并降低细胞内ROS和MDA水平。结论:GLEXG通过Keap1/Nrf2通路抑制自噬,有效减轻MGS细胞模型的氧化损伤。

金属硫化物在电催化二氧化碳还原反应中的应用

金属硫化物作为催化剂材料具有高稳定性、金属边缘活性和硫空位的协同效应等特点,特别是对二氧化碳(CO_(2))电还原反应表现出良好的活性和选择性,有望成为高效的CO_(2)电还原催化剂.鉴于此,综述了金属硫化物在电催化CO_(2)还原反应中的研究进展,分别归纳了第四周期、第五周期及第六周期中主要的金属硫化物电催化CO_(2)还原反应的性能、还原产物特点及影响因素等;特别分析了金属硫化物中S组分调控对催化性能的影响规律,以期实现更高效的电催化CO_(2)还原转化过程.此外,总结分析了目前金属硫化物催化剂存在的主要问题和瓶颈,并展望未来的研究重点和发展方向.

Unraveling the Role of Nitrogen-Doped Carbon Nanowires Incorporated with MnO_(2)Nanosheets as High Performance Cathode for Zinc-Ion Batteries

Manganese-based cathode materials are considered as a promising candidate for rechargeable aqueous zinc-ion batteries(ZIBs).Suffering from poor conductive and limited structure tolerance,various carbon matrix,especially N-doped carbon,were employed to incorporate with MnO_(2)for greatly promoted electrochemical performances.However,the related underlying mechanism is still unknown,which is unfavorable to guide the design of high performance electrode.Herein,by incorporating layered MnO_(2)with N-doped carbon nanowires,a free-standing cathode with hierarchical core-shell structure(denoted as MnO_(2)@NC)is prepared.Benefiting from the N-doped carbon and rational architecture,the MnO_(2)@NC electrode shows an enhanced specific capacity(325 mAh g^(−1)at 0.1 A g^(−1))and rate performance(90 mAh g^(−1)at 2 A g^(−1)),as well as improved cycling stability.Furthermore,the performance improvement mechanism of MnO_(2)incorporated by N-doped carbon is investigated by X-ray photoelectron spectroscopy(XPS),Raman spectrums and density functional theory(DFT)calculation.The N atom elongates the Mn-O bond and reduces the valence of Mn^(4+)ion in MnO_(2)crystal by delocalizing its electron clouds.Thus,the electrostatic repulsion will be weakened when Zn^(2+)/H^(+)insert into the host MnO_(2)lattices,which is profitable to more cation insertion and faster ion transfer kinetics for higher capacity and rate capability.This work elucidates a fundamental understanding of the functions of N-doped carbon in composite materials and shed light on a practical pathway to optimize other electrode materials.

Recycling Carbon Resources from Waste PET to Reduce Carbon Dioxide Emission:Carbonization Technology Review and Perspective

Greenhouse gas emissions from waste plastics have caused global warming all over the world,which has been a central threat to the ecological environment for humans,flora and fauna.Among waste plastics,waste polyethylene terephthalate(PET)is attractive due to its excellent stability and degradation-resistant.Therefore,merging China’s carbon peak and carbon neutrality goals would be beneficial.In this review,we summarize the current state-of-the-art of carbon emission decrease from a multi-scale perspective technologically.We suggest that the carbon peak for waste PET can be achieved by employing the closed-loop supply chain,including recycling,biomass utilization,carbon capture and utilization.Waste PET can be a valuable and renewable resource in the whole life cycle.Undoubtedly,all kinds of PET plastics can be ultimately converted into CO_(2),which can also be feedstock for various kinds of chemical products,including ethyl alcohol,formic acid,soda ash,PU,starch and so on.As a result,the closed-loop supply chain can help the PET plastics industry drastically reduce its carbon footprint.

A gap-free reference genome reveals structural variations associated with flowering time in rapeseed(Brassica napus)

Allopolyploid oilseed rape(Brassica napus)is an important oil crop and vegetable.However,the latest version of its reference genome,with collapsed duplications,gaps,and other issues,prevents comprehensive genomic analysis.Herein,we report a gap-free assembly of the rapeseed cv.Xiang5A genome using a combination of ONT(Oxford Nanopore Technologies)ultra-long reads,PacBio high-fidelity reads,and Hi-C datasets.It includes gap-free assemblies of all 19 chromosomes and telomere-to-telomere assemblies of eight chromosomes.Compared with previously published genomes of B.napus,our gap-free genome,with a contig N50 length of 50.70 Mb,has complete assemblies of 9 of 19 chromosomes without manual intervention,and greatly improves contiguity and completeness,thereby representing the highest quality genome assembly to date.Our results revealed that B.napus Xiang5A underwent nearly complete triplication and allotetraploidy relative to Arabidopsis thaliana.Using the gap-free assembly,we found that 917 flowering-related genes were affected by structural variation,including BnaA03.VERNALIZATION INSENSITIVE 3 and BnaC04.HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES 1.These genes may play crucial roles in regulating flowering time and facilitating the adaptation of Xiang5A in the Yangtze River Basin of China.This reference genome provides a valuable genetic resource for rapeseed functional genomic studies and breeding.

单次大剂量观察壮瑶药提取物对STZ所致高血糖小鼠的降血糖作用研究

目的:复制链脲佐菌素(STZ)所致高血糖小鼠模型,用于筛选单次大剂量条件下壮瑶药提取物和活性单体对高血糖小鼠的降血糖作用,为壮瑶药降血糖药物的开发提供实验和理论依据。方法:采用腹腔注射(ip.)STZ(剂量150 mg/kg,10 m L/kg)复制高血糖小鼠模型。72 h后,来源于壮瑶药的9种市售提取物、11种实验室制备提取物、5种产品制剂和30种活性单体被用于初筛,其中55种提取物或活性单体中有15种被认为具有潜在的降血糖作用,用于下一步检测。铁皮石斛多糖(1.6 g/kg),石仙桃多糖(1.6 g/kg),凤尾草水提物(100 g/kg),香砂水提物(200 g/kg),银花牛蒡茶(200 g/kg),蒲丁茶(200 g/kg),采用灌胃单次给药,9种活性单体(ZYDC1、ZYDC3、ZYDC5、ZYDD2、ZYDD3、ZYDD4、ZYDD5、ZYDD6和ZYDF1,采用同一剂量120 mg/kg)采用颈背部皮下注射单次给药,药后2 h,采血检测血糖值,并计算血糖差值、血糖下降率和降血糖积分。结果:与模型组比较,除活性单体ZYDC1和ZYDD5外,其余提取物或活性单体均被认为有明显的降血糖作用,石仙桃多糖和ZYDC3药后可显著降低药后血糖值(P<0.05或P<0.01),除ZYDC1、ZYDD5和铁皮石斛多糖外,其余提取物或活性单体均可显著增加血糖差值(P<0.05或P<0.01),石仙桃多糖、凤尾草水提物、香砂水提物、银花牛蒡茶、ZYDC3、ZYDC5、ZYDD2和ZYDD4均可显著增加血糖下降率(P<0.05或P<0.01),除ZYDC1、ZYDD5和ZYDF1外,其余提取物或活性单体均可显著增加降血糖积分(P<0.05或P<0.01)。与药前血糖值比较,石仙桃多糖、凤尾草水提物和香砂水提物均可降低药后血糖值(P<0.05或P<0.01)。结论:在本实验条件下,13种壮瑶药提取物或活性单体有明显的降血糖作用,依照降血糖积分大小顺序排列分别为ZYDC3、石仙桃多糖、铁皮石斛多糖、蒲丁茶、ZYDD6、ZYDD3、ZYDD4、凤尾草水提物、ZYDF1、ZYDD2、香砂水提物、银花牛蒡茶和ZYDC5。

Establishment and study of a polarized X-ray radiation facility

With the advancement in X-ray astronomical detection technology,various celestial polarization detection projects have been initiated.To meet the calibration requirements of polarimeters on the ground,a polarized X-ray radiation facility was designed for this study.The design was based on the principle that X-rays incident at 45°on a crystal produce polarized X-rays,and a second crystal was used to measure the polarization of the X-rays produced by the facility after rotation.The effects of different diaphragm sizes on the degree of polarization were compared,and the facility produced X-rays with polarization degrees of up to 99.55±0.96%using LiF200 and LiF220 crystals.This result revealed that the polarization of incident X-rays is one of the factors affecting the diffraction efficiency of crystals.The replacement of different crystals can satisfy the calibration requirements of polarized X-ray detectors with more energy points in the energy range(4-10)keV.In the future,the facility should be placed in a vacuum environment to meet the calibration requirements at lower energies.

Reference values of gait parameters in healthy Chinese university students: A cross-sectional observational study

BACKGROUND Gait is influenced by race,age,and diseases type.Reference values for gait are closely related to numerous health outcomes.To gain a comprehensive understanding of gait patterns,particularly in relation to race-related pathologies and disorders,it is crucial to establish reference values for gait in daily life considering sex and age.Therefore,our objective was to present sex and age-based reference values for gait in daily life,providing a valuable foundation for further research and clinical applications.AIM To establish reference values for lower extremity joint kinematics and kinetics during gait in asymptomatic adult women and men.METHODS Spatiotemporal,kinematics and kinetics parameters were measured in 171 healthy adults(70 males and 101 females)using the computer-aided soft tissue foot model.Full curve statistical parametric mapping was performed using independent and paired-samples t-tests.RESULTS Compared with females,males required more time(cycle time,double-limb support time,stance time,swing time,and stride time),and the differences were statistically significant.In addition,the step and stride lengths of males were longer.Compared to males,female cadence was faster,and statures-per-second and stride-per-minute were higher.There were no statistical differences in speed and stride width between the two groups.After adjusting for height,it was observed that women walked significantly faster than men,and they also had a higher cadence.However,in terms of step length,stride length,and stride width,both genders exhibited similarities.CONCLUSION We established reference values for gait speed and spatiotemporal gait parameters in Chinese university students.This contributes to a valuable database for gait assessment and evaluation of preventive or rehabilitative programs.

豫西偃龙地区本溪组铝土矿成矿物质来源分析

豫西偃(师)龙(门)地区本溪组铝土矿是华北陆块南部铝土矿成矿区的重要组成部分,与世界其他地区的岩溶型铝土矿一样,其成矿物质来源争议较大。本文选取偃龙地区本溪组铝土矿中具有代表性的豆鲕(碎屑)状铝土矿和铝土质泥岩两种岩性进行LA-ICP-MS碎屑锆石U-Pb测年,并辅以Hf同位素测定,分析了偃龙地区铝土矿的物质来源及其性质。结果表明,偃龙地区本溪组铝土矿碎屑锆石年龄可分为两组,第一组378~544Ma,峰值为443Ma,除378Ma一颗锆石为泥盆纪外,其余为早古生代,对应加里东期的年龄,占73%;第二组629~3116Ma,为前寒武纪年龄,占27%,具有三个较明显的年龄峰值,992Ma、1817Ma和2500Ma,分别对应四堡期—晋宁期、吕梁期和五台期的年龄。加里东期和四堡期—晋宁期碎屑锆石具有明显的岩浆锆石特征,吕梁期和五台期的碎屑锆石主要为岩浆锆石的变质增生锆石。加里东期和四堡期—晋宁期碎屑锆石(占85.3%)来源于北秦岭造山带,少量的(占6.4%)吕梁期和五台期的碎屑锆石可能来源于下伏马家沟组灰岩的岩溶不溶物。

河南省巩义地区本溪组铝土矿成矿物质来源——来自碎屑锆石LA-ICP-MS U-Pb年龄的证据

巩义地区是河南省本溪组铝土矿发现最早的地区,也是豫西铝土矿成矿带的重要组成部分,但对其成矿物质来源尚不清晰。选取该区一个露天采坑内的豆鲕状铝土矿样品,进行岩石薄片观察、X衍射分析和LA-ICP-MS碎屑锆石U-Pb测年。结果表明,该区铝土矿主要矿物成分为硬水铝石、锐钛矿和伊利石;碎屑锆石年龄可以分成2组,第一组介于393—484 Ma间,峰值约为442 Ma,占86%,主要为早古生代岩浆锆石,第二组介于555—2 714 Ma间,具有约901 Ma,约1 718 Ma,约2 440 Ma的峰值年龄,占14%,主要为前寒武纪岩浆锆石或为岩浆成因的变质增生锆石;早古生代碎屑锆石主要来自于北秦岭造山带加里东期中-酸性花岗质侵入岩,前寒武纪碎屑锆石可能主要来源于北秦岭地区的变质地层,它们与侵入其中的加里东期岩浆岩一同被剥蚀,共同为研究区提供物源;该区铝土矿中缺少晚古生代碎屑锆石的原因可能与远离内蒙古隆起,靠近北秦岭造山带有关。

豫西偃龙地区本溪组含铝岩系的原岩恢复及其地质意义

为了揭示华北陆块上古生界最底部上石炭统-下二叠统本溪组含铝岩系承载的地质信息,以华北陆块南部豫西偃龙地区ZK0008钻孔为研究对象,系统采集本溪组含铝岩系样品,利用多种测试方法,确定含铝岩系矿物成分、矿物赋存状态、元素含量及其垂向变化,并依据土壤化学基本原理,分析本溪组含铝岩系矿物成因及矿物垂向变化的原因,进而恢复该区含铝岩系的原岩并讨论其地质意义。结果表明:该区本溪组含铝岩系矿物成分主要为硬水铝石矿物和黏土矿物,多为隐晶质集合体;相对难迁移元素主要富集在豆鲕状铝土矿中,相对易迁移元素主要富集在铝土质泥岩中;含铝岩系中矿物成分垂向上的变化是原岩不同程度富铁铝化的结果,原岩主要为来自北秦岭造山带、成分成熟度很低的长石和/或岩屑粉砂岩;本溪组原岩沉积时,海平面抬升可抵达北秦岭造山带的山前地区,可能由突发式的快速海侵引起,缓慢的海退可将来自北秦岭造山带的长石和/或岩屑带到离物源区较远的区域沉积;湿热多雨气候条件下,本溪组原始沉积物暴露地表时迅速彻底富铁铝化,形成一个典型的富铁铝化剖面,海平面多次升降旋回造成本溪组含铝岩系多个富铁铝化剖面叠置。

Detection and Clinical Significance of Peripheral Blood CTC, CA125, CA153, and CEA Levels in Patients with Ductal Carcinoma in situ

Objective:To explore the detection and clinical significance of peripheral blood CTC,CA125,CA153,and CEA levels in patients with DCIS.Methods:210 patients who received surgical treatment for breast cancer in our hospital from January 2019 to December 2022 were selected as the research subjects.According to the postoperative pathology,100 cases were divided into breast cancer and 110 benign breast tumor groups.One hundred ten healthy patients undergoing physical examination during the same period were selected as the control group.CA153,CA125,and CEA levels were observed in the three groups.Results:The levels of CA153,CA125,and CEA in the breast cancer group were significantly higher than those in the benign breast tumor group and the control group(P<0.05);the levels of CA153,CA125,and CEA in the benign breast tumor group were all higher than those in the control group,but the differences were not statistically significant;among the three tumor markers,CA153 has the highest sensitivity at 39.00%,CA125 has the second highest sensitivity at 18.00%,and CEA has the lowest sensitivity at 17.00%;The sensitivity of the two joint tests of CA153+CA125,CA153+CEA,and CA125+CEA for the diagnosis of breast cancer were 50.00%,48.00%,and 26.00%respectively;the sensitivity of the three joint tests is the highest,reaching 53.00%,while the specificity of the joint tests was lower than the individual tests.Conclusion:Detection of peripheral blood CTC,CA125,CA153,and CEA levels has specific reference significance for the treatment and prognosis of DCIS patients.

PBL联合CBL教学法在外科实习中的实践

目的探索问题为导向的教学法(PBL)联合案例为导向的教学法(CBL)在外科临床实习中的应用效果。方法将实习生分为传统教学法组(对照组)及PBL联合CBL教学(PBL+CBL组),以外科出科考成绩以及问卷调查评估两种教学法在外科临床实习中的应用价值。结果 PBL+CBL组学生在外科出科考试中理论知识和技能操作成绩均高于对照组(P <0.05),PBL+CBL组在激发学习兴趣、提高学习自主性、巩固基础知识及总体满意度方面高于对照组(P <0.05)。结论 PBL联合CBL教学法对提高外科实习生理论知识和实践能力有很大的作用。

乌伦古坳陷东北侧油苗地化特征及其意义

准噶尔盆地东北缘乌伦古坳陷尚没有实质性的油气勘探突破,缺失准噶尔盆地普遍具有的二叠系生油岩,被认为是其主要原因,尽管乌伦古坳陷的基底石炭系被认为是最有可能的潜在烃源岩,但能否形成具有现实意义的油气源,仍有疑问。在乌伦古坳陷东北侧地表露头上,发现了固体沥青油苗,油苗呈侵染状、火焰状和树枝状,侵入第四系土黄色未固结的沙土沉积物和花岗岩风化壳中。利用有机碳含量、岩石热解、氯仿沥青A、镜质体反射率、干酪根碳同位素和甾烷、萜烷类生物标志化合物分析,确认了油苗的存在,并与研究区烃源岩和已发现原油进行了对比。研究表明,油苗中有机碳含量高,具有典型的煤成油碳同位素比值,油源为油苗分布区的石炭系黑色泥岩;与准东地区以二叠系、中—上三叠统和侏罗系为烃源岩的原油差异较大,而与石炭系原油具有较好的类比性。根据区域构造分析,乌伦古坳陷所在区域的基底是中亚巨型复合造山系的一部分,与油苗所在位置石炭系的组成和构造特征相似,因此,油苗的发现及研究,不仅对研究区的油气勘探具有重要意义,同时也可为准噶尔盆地东北缘乌伦古坳陷的油气勘探提供参考。

Clinical Value of cfDNA Content in Peripheral Blood of Patients with Triple-Negative Breast Cancer

Objective:To explore the value of circulating free(cfDNA)content in the clinical diagnosis and treatment of triple-negative breast cancer(TNBC).Methods:A total of 39 TNBC patients,45 non-TNBC patients,and 50 healthy individuals admitted to the Baoding First Central Hospital during 2019-2022 were recruited.The clinical data,peripheral blood cfDNA concentration,and clinicopathological indicators of the patients were observed and analyzed.Results:The difference in clinical indicators such as age,age range,tumor size,clinical stage,and lymph node metastasis between patients with TNBC and non-TNBC was insignificant(P>0.05).The cfDNA concentrations(ng/mL)of the TNBC group,non-TNBC group,and healthy group were 24.12±4.98,15.36±4.12,and 3.12±1.02,respectively,and they are statistically different(P<0.05).The difference in cfDNA concentration was insignificant between TNBC patients with tumors≤2 cm and>2 cm(P>0.05)but was significant between TNBC patients with clinical stages I+II and III+IV(P<0.05).The cfDNA concentration in TNBC patients with lymph node metastasis was significantly higher than those without lymph node metastasis(P<0.05).Conclusion:cfDNA has an important application value in the diagnosis and treatment of breast cancer.By detecting the cfDNA level and its gene variation,valuable information about the progress and treatment effects of breast cancer can be obtained.This non-invasive detection method has a wide range of applications and can be used for early screening,auxiliary diagnosis,efficacy evaluation,and recurrence monitoring of breast cancer.

基于试验和数值方法的轴流压缩机噪声研究

基于试验结合数值方法对某轴流压缩机进行了噪声研究,并分别得到了该压缩机声压的幅频曲线和总声压级。两种方法得到的动叶频率,2倍叶频和3倍叶频幅值的相对关系基本一致;由于机械噪声的影响,试验方法所得到总声压级大于数值模拟法结果。通过对比两种方法所得到的结果,不仅证明了数值方法预测轴流压缩机噪声的可行性,还证明了数值方法可在轴流压缩机设计阶段为低噪声机组选型提供理论基础。