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Sex Determination in Homo sapiens as a Multi-Step Process: Potential for Development of Variants and Sex Differences in Disease Risk
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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
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Silencing transformer and transformer-2 in Zeugodacus cucurbitae causes defective sex determination with inviability of most pseudomales
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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
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Relative orbit determination algorithm of space targets with passive observation
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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
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The Impact of Sleep Determination on Procrastination before Bedtime:The Role of Anxiety
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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
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Research Progress on Purification Process, Content Determination and Pharmacological Action of Atractylodin
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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
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Determination of Chlorogenic Acid,Geniposide,Total Flavonoids and Total Triterpenes in Wulan-13
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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
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Overexpression of Kdm6b induces testicular differentiation in a temperature-dependent sex determination system
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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
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Determination of Benzoylaconitine Compounds in the Decoctions of Aconiti Lateralis Radix Praeparata(Heishun Pieces),Trichosanthis Fructus and Their Combination
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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
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Frequentist and Bayesian Sample Size Determination for Single-Arm Clinical Trials Based on a Binary Response Variable: A Shiny App to Implement Exact Methods
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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
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TLC Identification of Yao Medicine Pileostegia tomentellal and Extraction Technology and Content Determination of Umbelliferone
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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
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Field Load Test Based SHM System Safety Standard Determination for Rigid Frame Bridge
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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
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Determination of Salvianolic Acid B in Yiqi Huayu Prescription by HPLC
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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
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Maleness-on-the-Y(MoY) orthologue is a key regulator of male sex determination in Zeugodacus cucurbitae(Diptera:Tephritidae) 被引量:2
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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
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Soxllb regulates the migration and fate determination of Müller glia-derived progenitors during retina regeneration in zebrafish 被引量:4
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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
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Classifier for centrality determination with zero-degree calorimeter at the cooling-storage-ring external-target experiment
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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
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Revisiting the determination of Mount Olympus Height(Greece)
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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
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TLE orbit determination using simplex method
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作者 Jinghong Liu Wanting Long +3 位作者 Yunchen Wu Jin Xu Jizhang Sang Xiangxu Lei 《Geodesy and Geodynamics》 EI CSCD 2023年第5期438-455,共18页
Two-Line Element(TLE)datasets are the only orbital data source of Earth-orbiting space objects for many civil users for their research and applications.The datasets have uneven qualities that may affect the reliabilit... Two-Line Element(TLE)datasets are the only orbital data source of Earth-orbiting space objects for many civil users for their research and applications.The datasets have uneven qualities that may affect the reliability of the propagated positions of space objects using a single TLE.The least squares approach to use multiple TLEs also suffers from the poor quality of some TLEs,and reliable error information cannot be available.This paper proposes a simplex algorithm to estimate an optimal TLE from multiple TLEs and obtain the uncertainty of each element.It is a derivative-free technique that can deal with various orbit types.Experiments have demonstrated that using the TLE estimated from the simplex method is more reliable,stable,and effective than those from the batch least squares method.As an application example,the optimal TLE and its uncertainty are used for predicting the fallen area,keeping the actual fallen site in the prediction areas. 展开更多
关键词 Two-line element Reentry prediction Orbit determination Simplex method Least squares
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The impacts of ambiguity in preparation of 80% sulfuric acid solution and shaking time control of calibration solution on the determination of transparent exopolymer particles
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作者 Congcong Guo Guicheng Zhang +2 位作者 Shan Jian Wei Ma Jun Sun 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第4期50-58,共9页
The quantification of transparent exopolymer particles(TEP) by colorimetric method is of large error and low repeatability,one major reason of which is related to the absence of clear definition and evaluation for par... The quantification of transparent exopolymer particles(TEP) by colorimetric method is of large error and low repeatability,one major reason of which is related to the absence of clear definition and evaluation for part steps of the original method.It is obscure that the 80% sulfuric acid solution,acted as the extraction solution in the determination of TEP,is prepared based on a volume ratio or mass ratio.Furthermore,the change of solubility of recently available Gum Xanthan(GX) from the market means that the original protocol is no longer applicable,and the grinding of GX stock solution with a tissue grinder is replaced by shaking with a rotating shaker in the study to prevent the excessive dissolution of GX.We found that different preparation techniques could result in the varied concentrations of 80% H_(2)SO_(4).The duration of shaking during the preparation of standard solution significantly affected the slope of the calibration curve,which caused different correction results of TEP.The impacts of different extraction solution concentrations and shaking time of GX solution on the quantification of TEP were investigated based on the field sampling and laboratory analysis.The extraction capacities of H_(2)SO_(4) with different concentrations for Alcian Blue were distinct,but had limited effect on the final measuring result of TEP.The change of the standard curve slope came along with the variation of shaking time,which markedly altered the detection limit and calibration result,and the extended shaking time was in favor of the determination of low-concentration TEP.It was suggested that the extraction solution concentration,shaking time and filtration volume of standard solution are required to be well controlled and selected to obtain more accurate results for TEP with different concentrations. 展开更多
关键词 transparent exopolymer particles determination method method improvement sulfuric acid shaking time
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Simultaneous Determination of Six Components in Cortex Phellodendri by HPLC
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作者 Lian LIAN Guosheng WAN +1 位作者 Weili JIA Huiyuan GAO 《Agricultural Biotechnology》 CAS 2023年第2期87-90,共4页
[Objectives]This study was conducted to establish the method for simultaneous determination of six active components.[Methods]Simultaneous determination of chlorogenic acid,phellodendrine,magnoflorine,jatrorrhizine,pa... [Objectives]This study was conducted to establish the method for simultaneous determination of six active components.[Methods]Simultaneous determination of chlorogenic acid,phellodendrine,magnoflorine,jatrorrhizine,palmatine and berberine in Cortex Phellodendri was carried out by HPLC with a Diamonsil C18(4.6 mm×250 mm,5μm)column was used.The mobile phase was acetonitrile-water(1‰acetic acid,2 mmol ammonium acetate)solution in gradient elution.The detection wavelength was set at 280 nm,and the column temperature was kept at 25℃and the flow rate was 1 ml/min.[Results]The linear ranges of chlorogenic acid,phellodendrine,magnoflorine,jatrorrhizine,palmatine and berberine were 20.00-320.00,18.75-130.00,25.00-200.00,5.00-100.00,20.00-200.00,and 0.09-1.80 mg/L,respectively.The average recovery was 98.1%,99.4%,97.5%,97.3%,104.0%,and 98.5%,respectively;and the RSDs were 0.5%,0.6%,0.8%,1.0%,1.4%,and 0.9%,respectively.[Conclusions]The method is convenient,stable,reliable and suitable for quality control of Cortex Phellodendri. 展开更多
关键词 Cortex Phellodendri Chlorogenic acid Phellodendrine MAGNOFLORINE JATRORRHIZINE PALMATINE BERBERINE determination
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Research Progress on Purification Process Optimization and Content Determination of Zeaxanthin
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作者 Jian LIU Jinglong CAO +3 位作者 Hui XUE Yannan LI Wenshuang HOU Chenghao JIN 《Asian Agricultural Research》 2023年第3期37-39,46,共4页
At present,the purification process of zeaxanthin mainly includes organic solvent extraction,ultrasonic-assisted extraction and enzyme extraction,and the content determination technology mainly includes ultraviolet-sp... At present,the purification process of zeaxanthin mainly includes organic solvent extraction,ultrasonic-assisted extraction and enzyme extraction,and the content determination technology mainly includes ultraviolet-spectrophotometry and high performance liquid chromatography.In this paper,the purification process and content determination technology of zeaxanthin in recent years are reviewed in order to provide ideas and theoretical basis for further research and application of zeaxanthin. 展开更多
关键词 ZEAXANTHIN CAROTENOID Purification process Content determination
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