期刊文献+
共找到68,002篇文章
< 1 2 250 >
每页显示 20 50 100
Sex Determination in Homo sapiens as a Multi-Step Process: Potential for Development of Variants and Sex Differences in Disease Risk
1
作者 David A. Hart 《Journal of Biomedical Science and Engineering》 2024年第1期13-34,共22页
Reproduction via cis-binary mechanisms appears to have evolved fairly early in the evolution of complex organisms, and a system committed to prior to evolution of humans. While the evolution of a chromosomal-specific ... Reproduction via cis-binary mechanisms appears to have evolved fairly early in the evolution of complex organisms, and a system committed to prior to evolution of humans. While the evolution of a chromosomal-specific approach has been a successful strategy for survival of a large variety of species including humans, the fidelity of sex determination leading to 100% cis-binary outcomes is not achieved in many species, with evidence for homosexual or bisexual behaviour evident in more than 1500 species. Thus, such outcomes indicates that sex determination is a multi-step process and not a single event, and as such, could lead to the appearance of variants during the process which developed much earlier than humans. Variants could arise either due to intrinsic variation in the steps of determination, or also be influenced by environmental factors of a biological or psychological nature. In contrast to homosexual variants which do not require interventions such as hormone therapy or surgery, expression of gender dysphoria, is more based in psychology, but also has biological underpinnings and can be influenced by such hormonal interventions and surgery. While the numbers of those with gender dysphoria is small (~0.6% - 1.0% of population), the attention given to this issue raises the possibility of biological and psychological environmental factors impacting the emergence of some of those expressing gender dysphoria. Furthermore, transitioning from male-to-female or female-to-male can have consequences regarding disease risks latter in life, including the appearance of autoimmune diseases. This review will attempt to review some of the evidence regarding sex determination, discuss why the system has potentially not been improved upon during evolution, how a potential role for sex chromosome function on neurodevelopment may be central to variation in humans, and how commitment to the current strategy is likely integrated into other sex-related events such as puberty, pregnancy, and menopause to ensure species survival. It will also discuss how variants in sex determination could contribute to sex differences in disease risk and how epigenetic modifications could play a role in such risk. . 展开更多
关键词 Sex determination Variant Development Fidelity of Sex determination Biological Sex determination Species Variation
下载PDF
Silencing transformer and transformer-2 in Zeugodacus cucurbitae causes defective sex determination with inviability of most pseudomales
2
作者 Qin Ma Zizhen Fan +5 位作者 Ping Wang Siya Ma Jian Wen Fengqin Cao Xianwu Lin Rihui Yan 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第3期938-947,共10页
transformer is a switch gene for sex determination in many insects, which cooperates with transformer-2 that is expressed in both sexes to regulate female differentiation, particularly in dipterans. Zeugodacus cucurbi... transformer is a switch gene for sex determination in many insects, which cooperates with transformer-2 that is expressed in both sexes to regulate female differentiation, particularly in dipterans. Zeugodacus cucurbitae(Coquillett) is a very destructive pest worldwide, however, its sex determination pathway remains largely uncharacterized. Here, we show that the female sex ratio is sharply reduced with knockdown of either transformer or transformer-2 by RNA interference in early embryos of Z. cucurbitae. Most of the males grown from the embryos with transient transformer and transformer-2 suppression mated with wild-type females and produced mixed sex progeny, with one exception that produced only female progeny, and all of the few remaining males failed to mate with wild-type females and produced no progeny. The exceptional male and those males with mating failure were XX pseudomales as determined by the detection of Y chromosome-linked Maleness-on-the-Y, indicating that most XX pseudomales are not viable. The phenotypes of transformer and transformer-2 suggest that they play a key role in regulating sex determination and are required for female sexual development of Z. cucurbitae. Our results will be beneficial to the understanding of sex determination in Z. cucurbitae and can facilitate the development of genetic sexing strains for its biological control. 展开更多
关键词 Zeugodacus cucurbitae TRANSFORMER transformer-2 sex determination RNA interference biological control
下载PDF
Relative orbit determination algorithm of space targets with passive observation
3
作者 DAI Chenchao QIANG Hongfu +2 位作者 ZHANG Degang HU Shaolei GONG Baichun 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第3期793-804,共12页
Angles-only relative orbit determination for space non-cooperative targets based on passive sensor is subject to weakly observable problem of the relative state between two spacecraft. Previously, the evidence for ang... Angles-only relative orbit determination for space non-cooperative targets based on passive sensor is subject to weakly observable problem of the relative state between two spacecraft. Previously, the evidence for angles-only observability was found by using cylindrical dynamics, however, the solution of orbit determination is still not provided. This study develops a relative orbit determination algorithm with the cylindrical dynamics based on differential evolution. Firstly, the relative motion dynamics and line-of-sight measurement model for nearcircular orbit are established in cylindrical coordinate system.Secondly, the observability is qualitatively analyzed by using the dynamics and measurement model where the unobservable geometry is found. Then, the angles-only relative orbit determination problem is modeled into an optimal searching frame and an improved differential evolution algorithm is introduced to solve the problem. Finally, the proposed algorithm is verified and tested by a set of numerical simulations in the context of highEarth and low-Earth cases. The results show that initial relative orbit determination(IROD) solution with an appropriate accuracy in a relative short span is achieved, which can be used to initialize the navigation filter. 展开更多
关键词 angles-only measurement relative orbit determination cylindrical coordinate differential evolution
下载PDF
The Impact of Sleep Determination on Procrastination before Bedtime:The Role of Anxiety
4
作者 Na Liu Junxiu Wang Wanli Zang 《International Journal of Mental Health Promotion》 2024年第5期377-387,共11页
Objective:The importance of good sleep for energy recovery and overall physical and mental health cannot be overstated.However,the increasing competitiveness of society,diversifying lifestyles,and the rapid spread of ... Objective:The importance of good sleep for energy recovery and overall physical and mental health cannot be overstated.However,the increasing competitiveness of society,diversifying lifestyles,and the rapid spread of the internet and electronic devices have significantly impacted people’s sleep patterns,particularly through bedtime procrastination.Therefore,this study aims to investigate the relationship and underlying mechanisms between sleep determination,anxiety,and bedtime procrastination among the Chinese population.Method:The study utilized data from a national survey—the China Residents’Sleep Condition Survey(November 2021,with 6,037 participants).By constructing mediation and moderation models,it analyzed the relationship and mechanisms between sleep determination and bedtime procrastination,highlighting the dual role of anxiety:as a mediator between sleep determination and bedtime procrastination,and as a moderator of their relationship.Results:There was a negative correlation between sleep determination and bedtime procrastination;anxiety was related to an increase in bedtime procrastination behaviors;In the interplay between sleep determination and pre-bedtime procrastination,the regulatory effect of anxiety is found to be more pronounced than its intermediary role,with anxiety significantly diminishing the inverse relationship between sleep determination and procrastination before bedtime.Conclusion:Bedtime procrastination can lead to sleep issues,thus reducing sleep quality.Enhancing sleep determination or alleviating pre-sleep anxiety can help inhibit bedtime procrastination behaviors.Intervening and reducing bedtime procrastination is one of the effective measures to improve sleep quality. 展开更多
关键词 Sleep determination bedtime procrastination ANXIETY MEDIATION moderation
下载PDF
Research Progress on Purification Process, Content Determination and Pharmacological Action of Atractylodin
5
作者 Xin SUN Jingwen WANG +1 位作者 Yang XI Chenghao JIN 《Asian Agricultural Research》 2024年第3期33-35,40,共4页
Atractylodis Rhizoma comes from the dry rhizome of Atractylis lancea or Atractylodes chinensis in the Compositae family,and it is suitable for preventing and treating diseases such as cold,edema,night blindness and rh... Atractylodis Rhizoma comes from the dry rhizome of Atractylis lancea or Atractylodes chinensis in the Compositae family,and it is suitable for preventing and treating diseases such as cold,edema,night blindness and rheumatic arthralgia.Atractylodin is the main active component extracted and isolated from Atractylodis Rhizoma.A large number of studies have found that atractylodin has excellent drug activity in improving gastrointestinal emptying,anti-inflammation,inhibiting malignant tumor and reducing blood lipid.In this paper,the purification process and pharmacological activity of Atractylodin were summarized to provide a theoretical basis for basic research,clinical application and further development and utilization of atractylodin. 展开更多
关键词 ATRACTYLODIN PHARMACOLOGICAL action PURIFICATION PROCESS CONTENT determination
下载PDF
Determination of Chlorogenic Acid,Geniposide,Total Flavonoids and Total Triterpenes in Wulan-13
6
作者 Xiaohua WU Burenbatu 《Medicinal Plant》 2024年第2期6-9,共4页
[Objectives]This study was conducted to establish a method for the determination of chlorogenic acid,geniposide,total flavonoids and total triterpenes in Wulan-13.[Methods]The contents of chlorogenic acid and geniposi... [Objectives]This study was conducted to establish a method for the determination of chlorogenic acid,geniposide,total flavonoids and total triterpenes in Wulan-13.[Methods]The contents of chlorogenic acid and geniposide were determined by HPLC,and the contents of total flavonoids and total triterpenes were determined by an ultraviolet spectrophotometer.[Results]There was a good linear relation between the mass of chlorogenic acid reference substance and the peak area in the range of 0.05-0.45μg,and the regression equation was Y=2524.1X+3.1943,(r=0.9998).A good linear relationship was found between the mass of gardenoside reference substance and the peak area in the range of 0.776-6.984μg,and the regression equation was Y=1670.5X+64.804,(r=0.9998).There was also a good linear relation between the mass of rutin reference substance and its absorbance in the range of 0.00808-0.04848 mg,and the regression equation was Y=12.916X+0.014,(r=0.999).The mass of oleanolic acid reference substance had a good linear relation with its absorbance in the range of 0.00418-0.0209 mg,and the regression equation was Y=51.89X-0.0839,(r=0.9991).[Conclusions]The content determination method is simple,reliable and reproducible,and suitable for controlling the contents of chlorogenic acid,geniposide,total flavonoids and total triterpenes in Wulan-13. 展开更多
关键词 Wulan-13 HPLC Ultraviolet spectrophotometer Content determination
下载PDF
Overexpression of Kdm6b induces testicular differentiation in a temperature-dependent sex determination system
7
作者 Qiran Chen Wei Sun +3 位作者 Lin Jin Yingjie Zhou Fang Li Chutian Ge 《Zoological Research》 SCIE CSCD 2024年第5期1108-1115,共8页
In reptiles,such as the red-eared slider turtle(Trachemys scripta elegans),gonadal sex determination is highly dependent on the environmental temperature during embryonic stages.This complex process,which leads to dif... In reptiles,such as the red-eared slider turtle(Trachemys scripta elegans),gonadal sex determination is highly dependent on the environmental temperature during embryonic stages.This complex process,which leads to differentiation into either testes or ovaries,is governed by the finely tuned expression of upstream genes,notably the testis-promoting gene Dmrt1 and the ovary-promoting gene Foxl2.Recent studies have identified epigenetic regulation as a crucial factor in testis development,with the H3K27me3 demethylase KDM6B being essential for Dmrt1 expression in T.s.elegans.However,whether KDM6B alone can induce testicular differentiation remains unclear.In this study,we found that overexpression of Kdm6b in T.s.elegans embryos induced the male development pathway,accompanied by a rapid increase in the gonadal expression of Dmrt1 at 31°C,a temperature typically resulting in female development.Notably,this sex reversal could be entirely rescued by Dmrt1 knockdown.These findings demonstrate that Kdm6b is sufficient for commitment to the male pathway,underscoring its role as a critical epigenetic regulator in the sex determination of the red-eared slider turtle. 展开更多
关键词 Temperature-dependent sex determination Sex reversal Kdm6b DMRT1 T.s.elegans
下载PDF
Determination of Benzoylaconitine Compounds in the Decoctions of Aconiti Lateralis Radix Praeparata(Heishun Pieces),Trichosanthis Fructus and Their Combination
8
作者 Luyao XIE Xiaoxia LI +7 位作者 Jing FU Jinhua LIU Yaobin HUANG Xuri WEI Tingting MO Shaomian PAN Lin HUANG Jiabao MA 《Medicinal Plant》 2024年第3期1-3,22,共4页
[Objectives]This study was conducted to determine the contents of benzoylmesaconine,benzoylaconitine and benzoylhypacoitine in the decoctions of Heishun pieces,Trichosanthis Fructus and their combination.[Methods]Heis... [Objectives]This study was conducted to determine the contents of benzoylmesaconine,benzoylaconitine and benzoylhypacoitine in the decoctions of Heishun pieces,Trichosanthis Fructus and their combination.[Methods]Heishun pieces,Trichosanthis Fructus and their combination were extracted for different time periods,and then grouped.HPLC was performed using an Agilent ZORBAX SB-C 18 chromatographic column(4.6 mm×250 mm,5μm)and acetonitrile-0.02 mol/L sodium dihydrogen phosphate as the mobile phase at a flow rate of 1 mL/min and a column temperature of 30℃,and the sample volume was 20μL.The detection wavelength was 230 nm.[Results]The total amounts of benzoylmesaconine,benzoylaconitine and benzoylhypacoitine in the single decoction group of Heishun pieces were all significantly different from those in the combined decoction group at corresponding time.[Conclusions]The total content of the benzoylaconitine type increased significantly after the combined decoction of Heishun pieces and Fructus Trichosanthis,which proves the scientificity of"eighteen incompatible medicaments,19 counteraction"in traditional Chinese medicine to some extent. 展开更多
关键词 Aconiti Lateralis RADIX Praeparata Trichosanthis Fructus Benzoylaconitine COMPOUND CONTENT determination
下载PDF
Frequentist and Bayesian Sample Size Determination for Single-Arm Clinical Trials Based on a Binary Response Variable: A Shiny App to Implement Exact Methods
9
作者 Susanna Gentile Valeria Sambucini 《Open Journal of Statistics》 2024年第1期90-105,共16页
Sample size determination typically relies on a power analysis based on a frequentist conditional approach. This latter can be seen as a particular case of the two-priors approach, which allows to build four distinct ... Sample size determination typically relies on a power analysis based on a frequentist conditional approach. This latter can be seen as a particular case of the two-priors approach, which allows to build four distinct power functions to select the optimal sample size. We revise this approach when the focus is on testing a single binomial proportion. We consider exact methods and introduce a conservative criterion to account for the typical non-monotonic behavior of the power functions, when dealing with discrete data. The main purpose of this paper is to present a Shiny App providing a user-friendly, interactive tool to apply these criteria. The app also provides specific tools to elicit the analysis and the design prior distributions, which are the core of the two-priors approach. 展开更多
关键词 Binomial Proportion Frequentist and Bayesian Power Functions Exact Sample Size determination Shiny App Two-Priors Approach
下载PDF
TLC Identification of Yao Medicine Pileostegia tomentellal and Extraction Technology and Content Determination of Umbelliferone
10
作者 Jiangcun WEI Xiumei MA +5 位作者 Meiyan QIU Bing QING Jingrong LU Hong LEI Xiaodong HUANG Wen ZHONG 《Medicinal Plant》 2024年第2期15-17,20,共4页
[Objectives]To establish a TLC and content determination method of Pileostegia tomentellal,with umbelliferone as the indicator component.[Methods]TLC identification was performed by silica gel G thin layer plate with ... [Objectives]To establish a TLC and content determination method of Pileostegia tomentellal,with umbelliferone as the indicator component.[Methods]TLC identification was performed by silica gel G thin layer plate with n-hexane-ethyl acetate(4:3)as the developing agent,and the plate was examined by UV lamp(365 nm).The umbelliferone content was determined by HPLC:Inertsil ODS-3 C 18 column(4.60 mm×250 mm,5μm);mobile phase acetonitrile-0.2%phosphoric acid gradient elution;detection wavelength 320 nm,flow rate 1.0 mL/min,column temperature 30℃,injection volume 10μL.[Results]The chromatogram of P.tomentellal showed the same color spot in the same position as that of reference medicinal material,and the spot was clear with good specificity.Umbelliferone showed a good linear relationship when the injection volume was 2.63-131.27μg/mL(R^(2)=0.9997).The average recovery of umbelliferone in the low,middle and high adding groups of P.tomentellal was 99.57%and the RSD was 2.15%.[Conclusions]The method can effectively identify Yao medicine P.tomentellal and accurately determine the content of umbelliferone in medicinal materials,which will provide a scientific basis for the development and utilization of medicinal resources of Yao medicine P.tomentellal. 展开更多
关键词 Pileostegia tomentellal TLC identification Extraction technology UMBELLIFERONE Content determination
下载PDF
Field Load Test Based SHM System Safety Standard Determination for Rigid Frame Bridge
11
作者 Xilong Zheng Qiong Wang Di Guan 《Structural Durability & Health Monitoring》 EI 2024年第3期361-376,共16页
The deteriorated continuous rigid frame bridge is strengthened by external prestressing. Static loading tests wereconducted before and after the bridge rehabilitation to verify the effectiveness of the rehabilitation ... The deteriorated continuous rigid frame bridge is strengthened by external prestressing. Static loading tests wereconducted before and after the bridge rehabilitation to verify the effectiveness of the rehabilitation process. Thestiffness of the repaired bridge is improved, and the maximum deflection of the load test is reduced from 37.9 to27.6 mm. A bridge health monitoring system is installed after the bridge is reinforced. To achieve an easy assessmentof the bridge’s safety status by directly using transferred data, a real-time safety warning system is createdbased on a five-level safety standard. The threshold for each safety level will be determined by theoretical calculationsand the outcomes of static loading tests. The highest risk threshold will be set at the ultimate limit statevalue. The remaining levels, namely middle risk, low risk, and very low risk, will be determined usingreduction coefficients of 0.95, 0.9, and 0.8, respectively. 展开更多
关键词 Continuous rigid frame bridge REHABILITATION long-term monitoring field load test safety standard determination
下载PDF
Determination of Salvianolic Acid B in Yiqi Huayu Prescription by HPLC
12
作者 Yingjing WANG Licheng SU +1 位作者 Yuliang HU Zhuqiang WANG 《Medicinal Plant》 2024年第1期32-34,共3页
[Objectives]To determine the content of salvianolic acid B in Yiqi Huayu Prescription by HPLC.[Methods]The chromatographic column was ZORBAX Eclipse Plus C 18(4.6 nm×250 nm,5μm);the mobile phase was acetonitrile... [Objectives]To determine the content of salvianolic acid B in Yiqi Huayu Prescription by HPLC.[Methods]The chromatographic column was ZORBAX Eclipse Plus C 18(4.6 nm×250 nm,5μm);the mobile phase was acetonitrile-0.1%phosphoric acid(21:79),the detection wavelength was 286 nm,the column temperature was 30℃,and the flow rate was 1.0 mL/min.A method for determination of salvianolic acid B in Yiqi Huayu Prescription was established.[Results]The linear relationship of salvianolic acid B was good in the range of 0.0214-0.4064 mg/mL.The regression equation was Y=5995.98984 X-0.07332,r=0.9999.The average recovery rate was 98.88%(RSD=1.6%).[Conclusions]The method is reliable,accurate and specific,and can be used for the determination of salvianolic acid B in Yiqi Huayu Prescription. 展开更多
关键词 Yiqi Huayu Prescription Salvianolic acid B High performance liquid chromatography Content determination
下载PDF
低盐水体Na^(+)/K^(+)对凡纳滨对虾生长、体成分与肝胰腺、鳃组织结构的影响 被引量:2
13
作者 祝华萍 苏家齐 +4 位作者 张子军 朱长波 张博 李婷 陈素文 《水产学报》 CAS CSCD 北大核心 2024年第3期87-95,共9页
缺钾在内陆低盐度盐碱水中经常发生,为探究低盐水体中不同钾缺乏程度对凡纳滨对虾生长、存活、体成分以及鳃和肝胰腺组织结构的影响,实验参照海水离子组成配置盐度为2的低盐度水体,在Na^(+)/K^(+)(mg/mg)比值为27、47、67、87、107 (分... 缺钾在内陆低盐度盐碱水中经常发生,为探究低盐水体中不同钾缺乏程度对凡纳滨对虾生长、存活、体成分以及鳃和肝胰腺组织结构的影响,实验参照海水离子组成配置盐度为2的低盐度水体,在Na^(+)/K^(+)(mg/mg)比值为27、47、67、87、107 (分别记为A、B、C、D、E组)的条件下,对体重为(1.04±0.23) g的凡纳滨对虾幼虾开展了为期60 d的养殖实验。结果显示,E组对虾的存活率为44.64%±20.95%,显著低于A、B、D三组;E组体重为(4.86±0.66) g,显著低于其他4组;A~D组之间的湿重、增重率、特定生长率差异不显著,但均大于E组且差异显著;在饲料系数上,E组最高并与A、D组差异显著。在体成分上,各组全虾钾含量、灰分含量差异不显著,E组的水分含量高于其他组,并与A、B组差异显著;E组粗蛋白含量最低,且与B组差异显著。E组对虾鳃组织角质层明显受损,红细胞数量减少,空泡增多,肝胰腺B细胞及其内部转运泡体积增大,肝小管结构受损。研究表明,低盐条件下严重缺钾引起了对虾鳃和肝胰腺损伤,降低了对虾的存活率和生长率;水体缺钾在前期即可对对虾的生长产生明显影响,而对存活的影响随养殖时间的增加而增大。实验结果有助于为内陆低盐度盐碱水养殖凡纳滨对虾提供理论依据。 展开更多
关键词 凡纳滨对虾 Na^(+)/K^(+) 生长 体成分 组织结构
下载PDF
Maleness-on-the-Y(MoY) orthologue is a key regulator of male sex determination in Zeugodacus cucurbitae(Diptera:Tephritidae) 被引量:2
14
作者 FAN Zi-zhen MA Qin +3 位作者 MA Si-ya CAO Feng-qin YAN Ri-hui LIN Xian-wu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第2期505-513,共9页
The initiation of sex differentiation in insects is regulated by primary sex determination signals.In the Medfly Ceratitis capitata and other tephritids,Maleness-on-the-Y(MoY) is the master gene for male sex determina... The initiation of sex differentiation in insects is regulated by primary sex determination signals.In the Medfly Ceratitis capitata and other tephritids,Maleness-on-the-Y(MoY) is the master gene for male sex determination.However,the primary signal in Zeugodacus cucurbitae(Coquillett),a very destructive tephritid pest across the world,remains ambiguous.In this study,we have isolated and characterized the Medfly MoY homolog in Z.cucurbitae,ZcMoY.ZcMOY protein shows high sequence conservation to its homologs in Bactrocera species.ZcMoY transcription begins and peaks at very early embryonic stages and then becomes undetectable except the testes and heads of day 1 male adults.Silencing ZcMoY in early embryos by RNAi causes abnormal external genitalia and interior reproductive organs,giving rise to intersexes and feminization of XY individuals.The expression pattern and knockdown phenotypes of ZcMoY indicate that ZcMoY plays a key role in regulating sex determination of Z.cucurbitae males.Our findings will help the understanding of sex determination in Z.cucurbitae and facilitate the development of genetic sexing strains in its biological control. 展开更多
关键词 MoY Zeugodacus cucurbitae sex determination RNA interference reproductive system
下载PDF
Soxllb regulates the migration and fate determination of Müller glia-derived progenitors during retina regeneration in zebrafish 被引量:4
15
作者 Kaida Song Zihao Lin +5 位作者 Lining Cao Bowen Lu Yuxi Chen Shuqiang Zhang Jianfeng Lu Hui Xu 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第2期445-450,共6页
The transcription factor Sox11 plays important roles in retinal neurogenesis during vertebrate eye development.However,its function in retina regeneration remains elusive.Here we report that Sox11 b,a zebrafish Sox11 ... The transcription factor Sox11 plays important roles in retinal neurogenesis during vertebrate eye development.However,its function in retina regeneration remains elusive.Here we report that Sox11 b,a zebrafish Sox11 homolog,regulates the migration and fate determination of Müller glia-derived progenitors(MGPCs)in an adult zebrafish model of mechanical retinal injury.Following a stab injury,the expression of Sox11 b was induced in proliferating MGPCs in the retina.Sox11 b knockdown did not affect MGPC formation at 4 days post-injury,although the nuclear morphology and subsequent radial migration of MGPCs were alte red.At 7 days post-injury,Sox11 b knockdown res ulted in an increased proportion of MGPCs in the inner retina and a decreased propo rtion of MGPCs in the outer nuclear layer,compared with controls.Furthermore,Sox11 b knockdown led to reduced photoreceptor regeneration,while it increased the numbe rs of newborn amacrines and retinal ganglion cells.Finally,quantitative polymerase chain reaction analysis revealed that Sox11 b regulated the expression of Notch signaling components in the retina,and Notch inhibition partially recapitulated the Sox11 b knockdown phenotype,indicating that Notch signaling functions downstream of Sox11 b.Our findings imply that Sox11 b plays key roles in MGPC migration and fate determination during retina regeneration in zebrafish,which may have critical im plications for future explorations of retinal repair in mammals. 展开更多
关键词 cell migration fate determination Müllerglia Müller glia-derived progenitor Notch signaling photoreceptor retina regeneration Sox11 transcription factor ZEBRAFISH
下载PDF
普通烟草外向整流Shaker K^(+)通道NtSKOR1的组织表达分析
16
作者 农童嘉 徐方正 +8 位作者 袁佳苹 向海英 王学瑛 袁光 OLUWASEYI Setonji Hunpatin 崔萌萌 宁扬 王倩 戴培刚 《中国烟草科学》 CSCD 北大核心 2024年第2期90-98,共9页
外向整流Shaker K^(+)通道SKOR(Stelar K^(+)outward rectifier)是一类定位于植物根部中柱细胞质膜的外向整流Shaker K^(+)通道。为探究普通烟草NtSKOR1的启动子活性和不同时期组织表达情况,克隆该基因上游2439 bp的启动子序列,创制启... 外向整流Shaker K^(+)通道SKOR(Stelar K^(+)outward rectifier)是一类定位于植物根部中柱细胞质膜的外向整流Shaker K^(+)通道。为探究普通烟草NtSKOR1的启动子活性和不同时期组织表达情况,克隆该基因上游2439 bp的启动子序列,创制启动子驱动β-葡萄糖苷酸酶基因(GUS)的烟草材料并进行组织化学染色,通过RT-qPCR验证该基因的表达。结果表明NtSKOR1启动子含有光响应、逆境胁迫和激素等相关的顺式作用元件;转ProNtSKOR1::GUS烟草的组织化学染色试验表明:萌发期至子叶展平期未检测到GUS活性;小十字期,在真叶叶脉和茎尖分生组织开始检测到GUS活性;生根期,除茎和叶脉的维管组织外,在根部维管组织也开始检测到明显GUS活性,且活性随烟株生长而逐渐增强;盛花期,主要在烟草的根、茎和叶脉维管组织检测到活性,且上部叶叶脉中的GUS活性高于下部叶叶脉。RT-qPCR与GUS活性检测结果基本一致。综上可知,NtSKOR1主要在烟草小十字期及后续发育阶段的根、茎、叶的维管组织中表达,烟草进入盛花期后,该基因在光合作用较强的上部叶中的表达高于下部叶,推测该基因可能参与烟草K^(+)转运和同化产物协同运输。 展开更多
关键词 NtSKOR1 Shaker K^(+)通道 GUS活性 烟草 基因表达
下载PDF
K^(+)掺杂双钙钛矿Cs_(2)AgInCl_(6)的发光性质
17
作者 徐锦锃 高辉 +2 位作者 陈国庆 王可可 胡金辉 《无机化学学报》 SCIE CAS CSCD 北大核心 2024年第2期405-411,共7页
采用固相球磨法制备了K^(+)掺杂双钙钛矿Cs_(2)AgInCl_(6)纳米材料,该方法无需配体辅助,绿色环保。通过X射线衍射和拉曼光谱对晶体结构进行研究,通过激发光谱、发射光谱和时间分辨光谱对其发光性能进行研究。结果表明,Cs_(2)AgInCl_(6)... 采用固相球磨法制备了K^(+)掺杂双钙钛矿Cs_(2)AgInCl_(6)纳米材料,该方法无需配体辅助,绿色环保。通过X射线衍射和拉曼光谱对晶体结构进行研究,通过激发光谱、发射光谱和时间分辨光谱对其发光性能进行研究。结果表明,Cs_(2)AgInCl_(6)为立方晶体,属于Fm3m空间群,由于宇称禁戒跃迁,其荧光量子产率(PLQY)低,小于0.1%。低于60%的K^(+)掺杂主要取代Ag^(+)的位置,引起Cs_(2)AgInCl_(6)的晶格膨胀,消除了晶格结构的反演对称性,打破了宇称禁戒跃迁,掺杂后Cs_(2)AgInCl_(6)的光致发光强度显著增强。K^(+)的最佳掺杂比例为40%,Cs_(2)Ag_(0.6)K_(0.4)InCl_(6)材料发射中心波长为640 nm,半高宽为180 nm,平均荧光寿命达到29.2 ns,PLQY达到10.5%。当K^(+)掺杂比例超过60%,K^(+)开始取代Cs+的位置,产物发生相变,出现立方相的Cs_(2-x)K_(1+x+y)AgyInCl_(6)和单斜相的Cs_(2-x)K_(1+x)InCl_(6)产物,这些产物由于强电子-声子耦合,非辐射复合占据主导地位。 展开更多
关键词 双钙钛矿 K^(+)掺杂 宇称禁戒跃迁 球磨法
下载PDF
Classifier for centrality determination with zero-degree calorimeter at the cooling-storage-ring external-target experiment
18
作者 Biao Zhang Li‑Ke Liu +3 位作者 Hua Pei Shu‑Su Shi Nu Xu Ya‑Ping Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第11期168-173,共6页
The zero-degree calorimeter(ZDC)plays a crucial role toward determining the centrality in the Cooling-Storage-Ring External-target Experiment(CEE)at the Heavy Ion Research Facility in Lanzhou.A boosted decision tree(B... The zero-degree calorimeter(ZDC)plays a crucial role toward determining the centrality in the Cooling-Storage-Ring External-target Experiment(CEE)at the Heavy Ion Research Facility in Lanzhou.A boosted decision tree(BDT)multi-classification algorithm was employed to classify the centrality of the collision events based on the raw features from ZDC such as the number of fired channels and deposited energy.The data from simulated^(238)U+^(238)U collisions at 500 MeV∕u,generated by the IQMD event generator and subsequently modeled using the GEANT4 package,were employed to train and test the BDT model.The results showed the high accuracy of the multi-classification model adopted in ZDC for centrality determination,which is robust against variations in different factors of detector geometry and response.This study demon-strates the good performance of CEE-ZDC in determining the centrality in nucleus-nucleus collisions. 展开更多
关键词 ZDC Boosted decision trees MULTI-CLASSIFICATION IQMD Centrality determination
下载PDF
Revisiting the determination of Mount Olympus Height(Greece)
19
作者 Dimitrios AMPATZIDIS Georgios MOSCHOPOULOS +7 位作者 Antonios MOURATIDIS Michael STYLLAS Alexandros TSIMERIKAS Vasileios-Klearchos DELIGIANNIS Nikolaos VOUTSIS Triantafyllia-Maria PERIVOLIOTI Georgios S.VERGOS Alexandra PLACHTOVA 《Journal of Mountain Science》 SCIE CSCD 2023年第4期1026-1034,共9页
The present study deals with the determination of Mount Olympus summit(Mytikas),exploiting modern observations such as Global Navigation Satellite Systems(GNSS)and existing geodetic information.The last official Olymp... The present study deals with the determination of Mount Olympus summit(Mytikas),exploiting modern observations such as Global Navigation Satellite Systems(GNSS)and existing geodetic information.The last official Olympus height determination goes back 102 years by the Swiss surveyor M.Kurz.Since then,only unofficial measurement campaigns have taken place.There is a variety of released heights,which range from 2917 to 2919 meters.In September and October of 2022,we conducted a GNSS campaign,focusing on the area of highest Olympus peaks.Employing precise GNSS measurements(accuracy of 1-3 cm),in conjunction with height information from Greece’s National Triangulation Network(5-10 cm accuracy)and an appropriate,recent geoid model(5-6 cm accuracy),we estimate through the so-called GNSS-levelling,the height of Olympus to 2917.727 m with respect to Greece’s officially accepted mean sea level and 2918.390 m with respect to the global vertical datum.Our estimation of Olympus highest peak shows remarkable consistency at the level of 12.8 cm to that of M.Kurz in 1921. 展开更多
关键词 OLYMPUS Greece Mountain height determination GNSS leveling SURVEYING
下载PDF
Na^(+)/K^(+)-ATPase:ion pump,signal transducer,or cytoprotective protein,and novel biological functions 被引量:2
20
作者 Songqiang Huang Wanting Dong +1 位作者 Xiaoqian Lin Jinsong Bian 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第12期2684-2697,共14页
Na^(+)/K^(+)-ATPase is a transmembrane protein that has important roles in the maintenance of electrochemical gradients across cell membranes by transporting three Na^(+)out of and two K^(+)into cells.Additionally,Na^... Na^(+)/K^(+)-ATPase is a transmembrane protein that has important roles in the maintenance of electrochemical gradients across cell membranes by transporting three Na^(+)out of and two K^(+)into cells.Additionally,Na^(+)/K^(+)-ATPase participates in Ca^(2+)-signaling transduction and neurotransmitter release by coordinating the ion concentration gradient across the cell membrane.Na^(+)/K^(+)-ATPase works synergistically with multiple ion channels in the cell membrane to form a dynamic network of ion homeostatic regulation and affects cellular communication by regulating chemical signals and the ion balance among different types of cells.Therefo re,it is not surprising that Na^(+)/K^(+)-ATPase dysfunction has emerged as a risk factor for a variety of neurological diseases.However,published studies have so far only elucidated the important roles of Na^(+)/K^(+)-ATPase dysfunction in disease development,and we are lacking detailed mechanisms to clarify how Na^(+)/K^(+)-ATPase affects cell function.Our recent studies revealed that membrane loss of Na^(+)/K^(+)-ATPase is a key mechanism in many neurological disorders,particularly stroke and Parkinson's disease.Stabilization of plasma membrane Na^(+)/K^(+)-ATPase with an antibody is a novel strategy to treat these diseases.For this reason,Na^(+)/K^(+)-ATPase acts not only as a simple ion pump but also as a sensor/regulator or cytoprotective protein,participating in signal transduction such as neuronal autophagy and apoptosis,and glial cell migration.Thus,the present review attempts to summarize the novel biological functions of Na^(+)/K^(+)-ATPase and Na^(+)/K^(+)-ATPase-related pathogenesis.The potential for novel strategies to treat Na^(+)/K^(+)-ATPase-related brain diseases will also be discussed. 展开更多
关键词 ANTIBODY biological functions cellular communication electrochemical gradient ion balance ion channels Na^(+)/K^(+)-ATPase neurological diseases neurotransmitter release signal transduction
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部