期刊文献+
共找到14,389篇文章
< 1 2 250 >
每页显示 20 50 100
Studies of the Variability of Primary Metabolites in the Epicarp, Mesocarp and Seed of Dacryodes edulis Fruit at Taste Maturity
1
作者 Etou Ossibi Grace Jokael Mbon Nguékou Chrichina +2 位作者 Ongouya Mouekouba Dalcantara Liana Mpika Joseph Attibayeba   《Advances in Biological Chemistry》 CAS 2024年第2期64-72,共9页
The fruits of Dacryodes edulis are rich in biologically active substances, which makes them of great interest in terms of validation. In this study, we targeted the primary metabolites in the epicarp, the mesocarp and... The fruits of Dacryodes edulis are rich in biologically active substances, which makes them of great interest in terms of validation. In this study, we targeted the primary metabolites in the epicarp, the mesocarp and the seed of the fruit of Dacryodes edulis at taste maturity, which were selected for their nutritional quality and its appreciation throughout the Gulf of Guinea area, which is very popular because of its large size, texture and special taste. The evaluation of total carbohydrates, total lipids and soluble proteins in the epicarp, mesocarp and seed of the fruit at taste maturity was made from spectrophotometer measurements. The overall analysis of the results of the present study shows that total carbohydrates, total lipids and proteins accumulate more in the seed with respectively 251.33 ± 1.15 mg/g DM;9.92 ± 0.201 mg/g DM and 55.075 ± 0.024 mg/g DM. Likewise, the results indicate low concentrations of total carbohydrates and total lipids in the epicarp with respectively 245 ± 1 mg/g DM and 4.77 ± 0.047 mg/g DM, on the other hand, it is the mesocarp which presents the lowest content of soluble proteins: 28.075 ± 3.231 mg/g DM. This variation could be linked to the nature of the compartment, more particularly to the storage location. This comparative study could lead to the valorization of the seed of the fruit of Dacryodes edulis for its richness in metabolites and arouse significant interest in nutrition. 展开更多
关键词 Dacryodes edulis FRUIT Taste maturity Epicarp MESOCARP SEED
下载PDF
A Proposed Approach for Measuring Maturity Level of Software Delivery
2
作者 Osama Hassan Mansour Atef Raslan Nagy Ramadan 《Journal of Software Engineering and Applications》 2024年第5期228-245,共18页
Software delivery is vital for modern organizations, driving innovation and competitiveness. Measuring an organization’s maturity in software delivery is crucial for efficiency and quality. The Capability Maturity Mo... Software delivery is vital for modern organizations, driving innovation and competitiveness. Measuring an organization’s maturity in software delivery is crucial for efficiency and quality. The Capability Maturity Model (CMM) framework provides a roadmap for improvement but assessing an organization’s CMM Level is challenging. This paper offers a quantitative approach tailored to the CMM framework, using Goal-Question-Metric (GQM) frame-works for each key process area (KPA). These frameworks include metrics and questions to compute maturity scores effectively. The study also refines practices into questions for a thorough assessment. The result is an Analysis Matrix that calculates weighted scores and an overall maturity score. This approach helps organizations assess and enhance their software delivery processes systematically, aiming for improved practices and growth. 展开更多
关键词 CMM CMMI Software Delivery maturity KPAs GQM PRACTICES
下载PDF
Correlation analysis of interstitial maturity and prognosis of colorectal cancer:Meta-analysis
3
作者 Zhen-Jun Liu Xu-Wen Zhang +1 位作者 Qi-Qi Liu Shao-Zhao Wang 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第6期2816-2825,共10页
BACKGROUND To investigate the relationship between interstitial maturity and prognosis of colorectal cancer.AIM To examine the correlation between interstitial maturity and the prognosis of colorectal cancer.METHODS T... BACKGROUND To investigate the relationship between interstitial maturity and prognosis of colorectal cancer.AIM To examine the correlation between interstitial maturity and the prognosis of colorectal cancer.METHODS The paper database PubMed,EMBASE,Cochranelibrary,Springerlink,CNKI,and Wanfang database were searched until December 2023."tumor stroma maturity""desmoplastic stroma reaction""desmoplastic reaction""stroma reaction""degree of stroma reaction""stroma classification""stroma density""colorectal cancer""colon cancer""rectal cancer""prognosis"were searched for the search terms.Two system assessors independently screened the literature quality according to the inclusion exclusion criteria,Quality evaluation and data extraction were performed for the included literatures,and meta-analysis was performed for randomized control trials included at using Review Manager 5.2 software.RESULTS Finally,data of 9849 patients with colorectal cancer from 19 cosets in 15 literatures were included,including 4339 patients with mature type(control group),3048 patients with intermediate type(intermediate group)and 2456 patients with immature type(immature group).The results of meta-analysis showed:Relapse-free survival[hazard ratio(HR)=2.66,95%confidence interval(CI):2.30-3.08;P<0.00001],disease-free survival(HR=3.68,95%CI:2.33-5.81;P<0.00001)and overall survival(HR=1.70,95%CI:1.53-1.87;P<0.00001)were significantly lower than those in mature group(control group);relapse-free survival(HR=1.36,95%CI:1.17-1.59;P<0.0001)and disease-free survival rate(HR=1.85,95%CI:1.53-2.24;P<0.0001)was significantly lower than the mature group(control group).CONCLUSION There is the correlation between tumor interstitial maturity and survival prognosis of colorectal cancer,and different degrees of tumor interstitial maturity have a certain impact on the quality of life of colorectal cancer patients. 展开更多
关键词 Colorectal tumor Survival prognosis Tumor interstitial maturity Systematic review META-ANALYSIS
下载PDF
High-resolution genome-wide association study of a large Czech collection of sweet cherry (Prunus avium L.) on fruit maturity and quality traits 被引量:2
4
作者 Kateřina Holušová JanaČmejlová +4 位作者 Pavol Suran RadekČmejla JiříSedlák Lubor Zelený Jan Bartoš 《Horticulture Research》 SCIE CSCD 2023年第1期113-127,共15页
In sweet cherry(Prunus avium L.),quantitative trait loci have been identified for fruit maturity,colour,firmness,and size to develop markers for marker-assisted selection.However,resolution is usually too low in those... In sweet cherry(Prunus avium L.),quantitative trait loci have been identified for fruit maturity,colour,firmness,and size to develop markers for marker-assisted selection.However,resolution is usually too low in those analyses to directly target candidate genes,and some associations are missed.In contrast,genome-wide association studies are performed on broad collections of accessions,and assemblies of reference sequences from Tieton and Satonishiki cultivars enable identification of single nucleotide polymorphisms after whole-genome sequencing,providing high marker density.Two hundred and thirty-five sweet cherry accessions were sequenced and phenotyped for harvest time and fruit colour,firmness,and size.Genome-wide association studies were used to identify single nucleotide polymorphisms associated with each trait,which were verified in breeding material consisting of 64 additional accessions.A total of 1767106 single nucleotide polymorphisms were identified.At that density,significant single nucleotide polymorphisms could be linked to co-inherited haplotype blocks(median size∼10 kb).Thus,markers were tightly associated with respective phenotypes,and individual allelic combinations of particular single nucleotide polymorphisms provided links to distinct phenotypes.In addition,yellow-fruit accessions were sequenced,and a∼90-kb-deletion on chromosome 3 that included five MYB10 transcription factors was associated with the phenotype.Overall,the study confirmed numerous quantitative trait loci from bi-parental populations using high-diversity accession populations,identified novel associations,and genome-wide association studies reduced the size of trait-associated loci from megabases to kilobases and to a few candidate genes per locus.Thus,a framework is provided to develop molecular markers and evaluate and characterize genes underlying important agronomic traits. 展开更多
关键词 FIR BREEDING maturity
下载PDF
ETL Maturity Model for Data Warehouse Systems:A CMMI Compliant Framework
5
作者 Musawwer Khan Islam Ali +6 位作者 Shahzada Khurram Salman Naseer Shafiq Ahmad Ahmed T.Soliman Akber Abid Gardezi Muhammad Shafiq Jin-Ghoo Choi 《Computers, Materials & Continua》 SCIE EI 2023年第2期3849-3863,共15页
The effectiveness of the Business Intelligence(BI)system mainly depends on the quality of knowledge it produces.The decision-making process is hindered,and the user’s trust is lost,if the knowledge offered is undesir... The effectiveness of the Business Intelligence(BI)system mainly depends on the quality of knowledge it produces.The decision-making process is hindered,and the user’s trust is lost,if the knowledge offered is undesired or of poor quality.A Data Warehouse(DW)is a huge collection of data gathered from many sources and an important part of any BI solution to assist management in making better decisions.The Extract,Transform,and Load(ETL)process is the backbone of a DW system,and it is responsible for moving data from source systems into the DW system.The more mature the ETL process the more reliable the DW system.In this paper,we propose the ETL Maturity Model(EMM)that assists organizations in achieving a high-quality ETL system and thereby enhancing the quality of knowledge produced.The EMM is made up of five levels of maturity i.e.,Chaotic,Acceptable,Stable,Efficient and Reliable.Each level of maturity contains Key Process Areas(KPAs)that have been endorsed by industry experts and include all critical features of a good ETL system.Quality Objectives(QOs)are defined procedures that,when implemented,resulted in a high-quality ETL process.Each KPA has its own set of QOs,the execution of which meets the requirements of that KPA.Multiple brainstorming sessions with relevant industry experts helped to enhance the model.EMMwas deployed in two key projects utilizing multiple case studies to supplement the validation process and support our claim.This model can assist organizations in improving their current ETL process and transforming it into a more mature ETL system.This model can also provide high-quality information to assist users inmaking better decisions and gaining their trust. 展开更多
关键词 ETL maturity model CMMI data warehouse maturity model
下载PDF
Resin composition: An indicator of oil maturity as revealed by fourier transform ion cyclotron resonance mass spectrometry
6
作者 Tian Liang Zhao-Wen Zhan +1 位作者 Guo-Xiang Wang Yan-Rong Zou 《Petroleum Science》 SCIE EI CAS CSCD 2023年第2期769-775,共7页
A pyrolysis experiment was carried out on a Dongying Depression kerogen sample to separate the resin from the oil. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with a positive-ion detector w... A pyrolysis experiment was carried out on a Dongying Depression kerogen sample to separate the resin from the oil. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with a positive-ion detector was used to detect the relative proportional changes in the compounds of the resin. During the whole pyrolysis experiment, the relative ratio of resin exceed 10% of the soluble component at each temperature point. Five compounds were detected from the resin: N1, N1O1, N1O_(2), O1, and O_(2). To research the changes in the proportions of the compounds during pyrolysis clearly, these five compounds were divided into three classes: N1, N1Ox, and Ox. The N1 class has the largest proportion in resin at the beginning of the pyrolysis, while Ox class has the least proportion. And the relationship between the number and the molecular mass of three classes compound was researched. With increasing maturity, the proportion of N1 and the N1Ox class decreased rapidly, while the Ox class increased slowly. Through researching these resin compounds, it was found that an inversion in the proportions of above three compounds appeared at the end of the oil window. At the same time, we found that the DBE and carbon number of resin compounds have changed obviously during the pyrolysis: the DBE increased, while the carbon number decreased significantly. And the details of the change of each compound have been researched. This research extends our knowledge of judging the maturity of crude oil during the pyrolysis through the characteristics of compounds in resin and provides the new index based on resin for the evaluation of thermal evolution stage and hydrocarbon generation capacity of source rocks. 展开更多
关键词 RESIN PYROLYSIS FT-ICR MS Heteroatom compound maturity DBE
下载PDF
Impact of stage-specific limb function exercises guided by a selfmanagement education model on arteriovenous fistula maturation status 被引量:1
7
作者 Yi Li Li-Jun Huang +1 位作者 Jian-Wen Hou Dan-Dan Hu 《World Journal of Clinical Cases》 SCIE 2024年第14期2316-2323,共8页
BACKGROUND The exercise of limb function is the most economical and safe method to promote the maturation of arteriovenous fistula(AVF).However,due to the lack of a uni-fied exercise standard in China,many patients ha... BACKGROUND The exercise of limb function is the most economical and safe method to promote the maturation of arteriovenous fistula(AVF).However,due to the lack of a uni-fied exercise standard in China,many patients have insufficient awareness of the importance of AVF,leading to poor effectiveness of limb function exercise.The self-management education model can effectively promote patients to take pro-active health-related actions.This study focuses on the characteristics of patients during the peri-AVF period and conducts a phased limb function exercise under the guidance of the self-management education model to observe changes in fac-tors such as the maturity of AVF.AIM To assess the impact of stage-specific limb function exercises,directed by a self-management education model,on the maturation status of AVFs.METHODS This study is a randomized controlled trial involving 74 patients with forearm AVFs from the Nephrology Department of a tertiary hospital in Sichuan Province,China.Patients were randomly divided into an observation group and a control group using a random number table method.The observation group underwent tailored stage-specific limb func-tion exercises,informed by a self-management education model which took into account the unique features of AVF at various stages,in conjunction with routine care.Conversely,the control group was given standard limb function exercises along with routine care.The assessment involves the maturity of AVFs post-intervention,post-operative complications,and the self-management level of the fistula in both groups patients.Analyses were conducted using SPSS version 23.0.Count data were represented by frequency and percentage and subjected to chi-square test comparisons.Measurement data adhering to a normal distribution were presented as mean±SD.The independent samples t-test was utilized for inter-group comparisons,while the paired t-test was used for intra-group comparisons.For measurement data not fitting a normal distribution,the median and interquartile range were presented and analyzed using the Wilcoxon rank sum test.RESULTS At the 8-wk postoperative mark,the observation group demonstrated significantly higher scores in AVF symptom recognition,symptom prevention,and self-management compared to the control group(P<0.05).However,the variance in symptom management scores between the observation and control groups lacked statistical signi-ficance(P>0.05).At 4 wk after the operation,the observation group displayed a superior vessel diameter and depth from the skin of the drainage vessels in comparison to the control group(P<0.05).While the observation group did manifest elevated blood flow rates in the drainage vessels relative to the control group,this distinction was not statistically significant(P>0.05).By the 8-wk postoperative interval,the observation group outperformed the control group with notable enhancements in blood flow rates,vessel diameter,and depth from the skin of drainage vessels(P<0.01).Seven days following the procedure,the observation group manifested significantly diminished limb swelling and an overall reduced complication rate in contrast to the control group(P<0.05).The evaluation of infection,thrombosis,embolism,arterial aneurysm stenosis,and incision bleeding showed no notable differences between the two groups(P>0.05).By the 4-wk postoperative juncture,complications between the observation and control groups were statistically indistinguishable(P>0.05).CONCLUSION Stage-specific limb function exercises,under the guidance of a self-management education model,amplify the capacity of AVF patients to discern and prevent symptoms.Additionally,they expedite AVF maturation and miti-gate postoperative limb edema,underscoring their efficacy as a valuable method for the care and upkeep of AVF in hemodialysis patients. 展开更多
关键词 SELF-MANAGEMENT Education model Stage-specific Limb function exercises Arteriovenous fistula maturation status
下载PDF
Enrichment conditions and distribution characteristics of lacustrine medium-to-high maturity shale oil in China
8
作者 ZHAO Wenzhi ZHU Rukai +2 位作者 LIU Wei BIAN Congsheng WANG Kun 《地学前缘》 EI CAS CSCD 北大核心 2023年第1期242-259,共18页
Successful breakthroughs have been made in shale oil exploration in several lacustrine basins in China,indicating a promising future for shale oil exploration and production.Current exploration results have revealed t... Successful breakthroughs have been made in shale oil exploration in several lacustrine basins in China,indicating a promising future for shale oil exploration and production.Current exploration results have revealed the following major conditions of lacustrine shale oil accumulation:(1)stable and widely distributed shale with a high organic abundance and appropriate thermal maturity acts as a fundamental basis for shale oil retention.This shale exhibits several critical parameters,such as total organic carbon content greater than 2%,with optimal values ranging from 3% to 4%,kerogen Ⅰ and Ⅱ_(1) as the dominant organic matter types,and vitrinite reflectance(R_(o))values greater than 0.9%(0.8% for brackish water environments).(2)Various types of reservoirs exhibiting brittleness and a certain volume of micro-nanoscale pores are critical conditions for shale oil accumulation,and these reservoirs have porosities greater than 3% to 6%.Moreover,when diagenesis is incipient,pure shales are not favorable for medium-to-high maturity shale oil enrichment,whereas tight sandstone and hybrid rocks with clay content less than 20% are favorable;however,for medium-to-late-stage diagenesis,pure shales with a clay content of 40% are favorable.(3)The retention of a large amount of high-quality hydrocarbons is the factor that best guarantees shale oil accumulation with good mobility.Free hydrocarbon content exceeding a threshold value of 2 mg/g is generally required,and the optimum value is 4 mg/g to 6 mg/g.Moreover,a gas-oil ratio exceeding a threshold value of 80 m^(3)/m^(3) is required,with the optimal value ranging from 150 m^(3)/m^(3) to 300 m^(3)/m^(3).(4)High-quality roof and floor sealing conditions are essential for the shale oil enrichment interval to maintain the overpressure and retain a sufficient amount of hydrocarbons with good quality.Lacustrine shale oil distributions exhibit the following characteristics:(1)major enrichment areas of shale oil are located in semi-deep to deep lacustrine depositional areas with external materials,such as volcanic ash fallout,hydrothermal solutions,and radioactive substances with catalytic action,as inputs;(2)intervals with“four high values and one preservation condition”govern the distribution of shale oil enrichment intervals;and(3)favorable assemblages of lithofacies/lithologies determine the distribution of enrichment area.According to preliminary estimates,China has 131×10^(8) to 163×10^(8) t of total shale oil resources with medium-to-high thermal maturity,among which 67×10^(8) to 84×10^(8) t is commercial.These resources are primarily located in the Chang 7^(1+2) interval in the Ordos Basin,Qing 1+2 members in Gulong sag in the Songliao Basin,Kongdian and Shahejie formations of Cangdong sag,Qikou sag and the Jiyang depression in the Bohai Bay Basin,and Lucaogou Formation in the Junggar Basin. 展开更多
关键词 medium-to-high maturity shale oil sweet-spot zone enrichment conditions distributional characteristics assessment standard onshore China
下载PDF
Lamellar Bodies Count (LBC) as a Predictor of Fetal Lung Maturity in Preterm Premature Rupture of Membranes Compared to Neonatal Assessment
9
作者 Malames Mahmoud Faisal Noha Hamed Rabei +1 位作者 Hoda Ezz El-Arab Abd El-Wahab Abeer Hosny El-Zakkary 《Open Journal of Obstetrics and Gynecology》 2023年第6期1047-1057,共11页
Background: Respiratory distress syndrome (RDS) is a major cause of neonatal morbidity and mortality, affecting approximately 1% of all live births and 10% of all preterm infants. Lamellar bodies represent a storage f... Background: Respiratory distress syndrome (RDS) is a major cause of neonatal morbidity and mortality, affecting approximately 1% of all live births and 10% of all preterm infants. Lamellar bodies represent a storage form of pulmonary surfactant within Type II pneumocytes, secretion of which increases with advancing gestational age, thus enabling prediction of the degree of FLM. Preterm premature rupture of membranes (PPROM) complicates approximately 1/3 of all preterm births. Birth within 1 week is the most likely outcome for any patient with PPROM in the absence of adjunctive treatments. Respiratory distress has been reported to be the most common complication of preterm birth. Sepsis, intraventricular haemorrhage, and necrotizing enterocolitis also are associated with prematurity, but these are less common near to term. Objective: To assess the efficacy of the amniotic fluid lamellar body counting from a vaginal pool in predicting fetal lung maturity in women with preterm premature rupture of membranes. Methods: This study was conducted at Ain Shams University Maternity Hospital in the emergency ward from January 2019 to September 2019. It included 106 women with singleton pregnancies, gestational age from 28 - 36 weeks with preterm premature rupture of membranes. This study is designed to assess the efficacy of the amniotic fluid lamellar body counting (LBC) from a vaginal pool in predicting fetal lung maturity in women with preterm premature rupture of membranes. Results: The current study revealed a highly significant increase in the lamellar body count in cases giving birth to neonates without RDS compared to that cases giving birth to neonates with RDS. Also, no statistically significant difference between LBC and age, parity and number of previous miscarriages in the mother was found. Gestational age at delivery was significantly lower among cases with respiratory distress. Steroid administration was significantly less frequent among cases with respiratory distress. However, lamellar bodies had high diagnostic performance in the prediction of respiratory distress. Conclusion: Lamellar body count (LBC) is an effective, safe, easy, and cost-effective method to assess fetal lung maturity (FLM). It does not need a highly equipped laboratory or specially trained personnel, it just needs the conventional blood count analyzer. Measurement of LBC is now replacing the conventional Lecithin/Sphyngomyelin L/S ratio. LBC cut-off value of ≤42.5 × 10<sup>3</sup>/μL can be used safely to decide fetal lung maturity with sensitivity of 95.7% and specificity of 97.6%. 展开更多
关键词 Fetal Lung maturity Lamellar Bodies Count Preterm Premature Rupture of Membranes Respiratory Distress Syndrome
下载PDF
Feasibility study of assessing cotton fiber maturity from near infrared hyperspectral imaging technique
10
作者 LIU Yongliang TAO Feifei +1 位作者 YAO Haibo KINCAID Russell 《Journal of Cotton Research》 CAS 2023年第4期266-276,共11页
Background Fiber maturity is a key cotton quality property,and its variability in a sample impacts fiber processing and dyeing performance.Currently,the maturity is determined by using established protocols in laborat... Background Fiber maturity is a key cotton quality property,and its variability in a sample impacts fiber processing and dyeing performance.Currently,the maturity is determined by using established protocols in laboratories under a controlled environment.There is an increasing need to measure fiber maturity using low-cost(in general less than $20000)and small portable systems.In this study,a laboratory feasibility was performed to assess the ability of the shortwave infrared hyperspectral imaging(SWIR HSI)technique for determining the conditioned fiber maturity,and as a comparison,a bench-top commercial and expensive(in general greater than $60000)near infrared(NIR)instrument was used.Results Although SWIR HSI and NIR represent different measurement technologies,consistent spectral characteristics were observed between the two instruments when they were used to measure the maturity of the locule fiber samples in seed cotton and of the well-defined fiber samples,respectively.Partial least squares(PLS)models were established using different spectral preprocessing parameters to predict fiber maturity.The high prediction precision was observed by a lower root mean square error of prediction(RMSEP)(<0.046),higher R_(p)^(2)(>0.518),and greater percentage(97.0%)of samples within the 95% agreement range in the entire NIR region(1000-2500 nm)without the moisture band at 1940 nm.Conclusion SWIR HSI has a good potential for assessing cotton fiber maturity in a laboratory environment. 展开更多
关键词 Near infrared spectroscopy Near infrared hyperspectral imaging Fiber maturity Seed cotton Partial least squares regression
下载PDF
Endogenous biosynthesis of docosahexaenoic acid(DHA)regulates fish oocyte maturation by promoting pregnenolone production
11
作者 Yi Li Xuehui Li +6 位作者 Ding Ye Ru Zhang Chengjie Liu Mudan He Houpeng Wang Wei Hu Yonghua Sun 《Zoological Research》 SCIE CSCD 2024年第1期176-188,共13页
Omega-3 polyunsaturated fatty acids(n-3 PUFAs),particularly docosahexaenoic acid(22:6n-3,DHA),play crucial roles in the reproductive health of vertebrates,including humans.Nevertheless,the underlying mechanism related... Omega-3 polyunsaturated fatty acids(n-3 PUFAs),particularly docosahexaenoic acid(22:6n-3,DHA),play crucial roles in the reproductive health of vertebrates,including humans.Nevertheless,the underlying mechanism related to this phenomenon remains largely unknown.In this study,we employed two zebrafish genetic models,i.e.,elovl2^(-/-)mutant as an endogenous DHAdeficient model and fat1(omega-3 desaturase encoding gene)transgenic zebrafish as an endogenous DHA-rich model,to investigate the effects of DHA on oocyte maturation and quality.Results show that the elovl2^(-/-)mutants had much lower fecundity and poorer oocyte quality than the wild-type controls,while the fat1 zebrafish had higher fecundity and better oocyte quality than wildtype controls.DHA deficiency in elovl2^(-/-)embryos led to defects in egg activation,poor microtubule stability,and reduced pregnenolone levels.Further study revealed that DHA promoted pregnenolone synthesis by enhancing transcription of cyp11a1,which encodes the cholesterol side-chain cleavage enzyme,thereby stabilizing microtubule assembly during oogenesis.In turn,the hypothalamic-pituitary-gonadal axis was enhanced by DHA.In conclusion,using two unique genetic models,our findings demonstrate that endogenously synthesized DHA promotes oocyte maturation and quality by promoting pregnenolone production via transcriptional regulation of cyp11a1. 展开更多
关键词 Docosahexaenoic acid Oocyte maturation Oocyte quality PREGNENOLONE MICROTUBULE
下载PDF
Effect of thermal maturation and organic matter content on oil shale fracturing
12
作者 Fatemeh Saberi Mahboubeh Hosseini‑Barzi 《International Journal of Coal Science & Technology》 EI CAS CSCD 2024年第2期16-34,共19页
The Pabdeh Formation represents organic matter enrichment in some oil fields,which can be considered a source rock.This study is based on the Rock–Eval,Iatroscan,and electron microscopy imaging results before and aft... The Pabdeh Formation represents organic matter enrichment in some oil fields,which can be considered a source rock.This study is based on the Rock–Eval,Iatroscan,and electron microscopy imaging results before and after heating the samples.We discovered this immature shale that undergoes burial and diagenesis,in which organic matter is converted into hydro-carbons.Primary migration is the process that transports hydrocarbons in the source rock.We investigated this phenomenon by developing a model that simulates hydrocarbon generation and fluid pressure during kerogen-to-hydrocarbon conversion.Microfractures initially formed at the tip/edge of kerogen and were filled with hydrocarbons,but as catagenesis progressed,the pressure caused by the volume increase of kerogen decreased due to hydrocarbon release.The transformation of solid kerogen into low-density bitumen/oil increased the pressure,leading to the development of damage zones in the source rock.The Pabdeh Formation’s small porethroats hindered effective expulsion,causing an increase in pore fluid pressure inside the initial microfractures.The stress accumulated due to hydrocarbon production,reaching the rock’s fracture strength,further contributed to damage zone development.During the expansion process,microfractures preferentially grew in low-strength pathways such as lithology changes,laminae boundaries,and pre-existing microfractures.When the porous pressure created by each kerogen overlapped,individual microfractures interconnected,forming a network of microfractures within the source rock.This research sheds light on the complex interplay between temperature,hydrocarbon generation,and the development of expulsion fractures in the Pabdeh Formation,providing valuable insights for understanding and optimizing hydrocarbon extraction in similar geological settings. 展开更多
关键词 Oil shale MICROFRACTURE Hydrocarbon generation Organic matter Thermal maturation Primary migration
下载PDF
A New Micropropagation Technology of Tilia amurensis:In VitroMicropropagation of Mature Zygotic Embryos and the Establishment of a PlantRegeneration System
13
作者 Shijie Lin Zimo Wang +8 位作者 Hongbo Zhu Conghui Wang Hongfeng Wang Dawei Zhang Tianbing Gou Guangdao Bao Ye Luo Huaijiang He Zhonghui Zhang 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第2期277-289,共13页
Tilia amurensis is an economically valuable broadleaf tree species in Northeast China.The production of highqualityT.amurensis varieties at commercial scales has been greatly limited by the low germination rates.There... Tilia amurensis is an economically valuable broadleaf tree species in Northeast China.The production of highqualityT.amurensis varieties at commercial scales has been greatly limited by the low germination rates.Thereis thus a pressing need to develop an organogenesis protocol for in vitro propagation of T.amurensis to alleviate ashortage of high-quality T.amurensis seedlings.Here,we established a rapid in vitro propagation system forT.amurensis from mature zygotic embryos and analyzed the effects of plant growth regulators and culture mediain different stages.We found that Woody plant medium(WPM)was the optimal primary culture medium formature zygotic embryos.The highest callus induction percentage(68.76%)and number of axillary buds induced(3.2)were obtained in WPM+0.89μmol/L 6-benzyladenine(6-BA)+0.46μmol/L kinetin(KT)+0.25μmol/Lindole-3-butryic acid(IBA)+1.44μmol/L gibberellin A_(3)(GA_(3)).The multiple shoot bud development achievedthe highest percentage(83.32%)in the Murashige and Skoog(MS)+2.22μmol/L 6-BA+0.25μmol/L IBA+1.44μmol/L GA_(3).The rooting percentage(96.70%)was highest in 1/2 MS medium+1.48μmol/L IBA.Thesurvival percentage of transplanting plantlets was 82.22%in soil:vermiculite:perlite(5:3:1).Our study is the firstto establish an effective organogenesis protocol for T.amurensis using mature zygotic embryos. 展开更多
关键词 Tilia amurensis Rupr. mature zygotic embryo MICROPROPAGATION adventitious bud multiplication ROOTING
下载PDF
Emma's Growth from Innocence to Maturity
14
作者 周道凤 《海外英语》 2013年第21期245-247,共3页
Emma is one of the most successful novels by Jane Austen.This thesis analyzed the background of its heroine Emma’s growth background,her growth from conceit,snobbery,domination to maturity,and the causes of her chara... Emma is one of the most successful novels by Jane Austen.This thesis analyzed the background of its heroine Emma’s growth background,her growth from conceit,snobbery,domination to maturity,and the causes of her character transformation.Her psychological growth process from innocence to maturity demonstrates women’s growth and progress in the early 19th cen tury,and inspires modern women to gradually improve in personality and better present their charms of maturity. 展开更多
关键词 EMMA GROWTH INNOCENCE maturity
下载PDF
Microbiological parameters and maturity degree during composting of Posidonia oceanica residues mixed with vegetable wastes in semi-arid pedo-climatic condition 被引量:35
15
作者 SAIDI Neyla KOUKI Soulwene +4 位作者 M'HIRI Fadhel JEDIDI Naceur MAHROUK Meriam HASSEN Abdennaceur OUZARI Hadda 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第10期1452-1458,共7页
The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues (VR) collected from markets of Tunis City with ... The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues (VR) collected from markets of Tunis City with residues of Posidonia oceanica (PoR), collected from Tunis beaches. The accumulation in beaches (as well as their removal) constitutes a serious environmental problem in all Mediterranean countries particularly in Tunisia. Aerobic-thermophilic composting is the most reasonable way to profit highly-valuable content of organic matter in these wastes for agricultural purposes. The physical, chemical, and biological parameters were monitored during composting over 150 d. The most appropriate parameters were selected to establish the maturity degree. The main result of this research was the deduction of the following maturity criterion: (a) C/N ratio 〈 15; (b) NH4^+-N 〈 400 mg/kg; (c) CO2-C 〈 2000 mg CO2-C/kg; (d) dehydrogenase activity 〈 1 mg TPF/g dry matter; (e) germination index (GI) 〉 80%. These five parameters, considered jointly are indicative of a high maturity degree and thus of a high-quality organic amendment which employed in a rational way, may improve soil fertility and soil quality. The mature compost was relatively rich in N (13.0 g/kg), P (4.74 g/kg) and MgO (15.80 g/kg). Thus composting definitively constitutes the most optimal option to exploit these wastes. 展开更多
关键词 soil degradation RECYCLING COMPOSTING organic amendment maturity degree
下载PDF
Oil maturity assessment using maturity indicators based on methylated dibenzothiophenes 被引量:15
16
作者 Li Meijun Wang T.-G +2 位作者 Shi Shengbao Zhu Lei Fang Ronghui 《Petroleum Science》 SCIE CAS CSCD 2014年第2期234-246,共13页
Aromatic fractions of 140 oils and condensates that originated from different types of source rocks (marine shale,terrestrial shale and marine carbonate) were analyzed using gas chromatographymass spectrometry (GC... Aromatic fractions of 140 oils and condensates that originated from different types of source rocks (marine shale,terrestrial shale and marine carbonate) were analyzed using gas chromatographymass spectrometry (GC-MS) to investigate the relative distributions of methylated dibenzothiophenes with respect to thermal maturity.The positions of methyl groups of trimethyldibenzothiophene isomers (TMDBTs) including those used in the definition of maturity indicator TMDBT index in previous studies were firmly identified by co-elution of internal standards in GC-MS analysis and by comparing with reported retention indices.A new maturity ratio related to dimethyldibenzothiophenes (DMDBTs) is proposed on the basis of the differences in thermodynamic stability among different DMDBT isomers.Another maturity index (TMDBT-I2) based on TMDBTs is also suggested on the basis of our empirical observations and presumed thermodynamic stability of TMDBT isomers.These two newly proposed (2,6 + 3,6)-/1,4-DMDBT ratio and TMDBT-I2 correlate well with MDR (4-/1-methyldibenzothiophene)and 2,4-/1,4-DMDBT ratios,suggesting their common chemical reaction mechanisms and similar behavior with increasing maturity.Therefore,they can be effectively applied for maturity assessments.Furthermore,the TMDBTs related maturity parameters are more reliable for over-mature oils and condensates due to the relatively higher concentrations of thermodynamically unstable TMDBT isomers,i.e.1,4,6-,1,4,8-and 3,4,6-TMDBT in this study than those of 1-methyldibenzothiophene (1-MDBT) or 1,4-DMDBT.In contrast with 4,6-/1,4-DMDBT,the newly proposed (2,6 + 3,6)-/1,4-DMDBT ratios for oils that originated from different types of source rocks have approximately same relationship with the oil maturity (Rc %).This suggests that the lithology and organic facies may have relatively less influence on (2,6 + 3,6)-/1,4-DMDBT ratio compared to 4,6-/1,4-DMDBT.The maturity parameters based on methylated dibenzothiophenes are particularly useful in the maturity assessments of post-and over-mature oils and condensates and can complement maturity indicators based on steranes and terpanes. 展开更多
关键词 DIBENZOTHIOPHENE maturity indicator molecular thermodynamic stability sedimentaryorganic matter
下载PDF
The Occurrence of Oleananes in the Beibuwan Basin and Its Application to the Study of Maturity and Oil-Source Rock Correlation 被引量:9
17
作者 LI Meijun WANG Tieguan +4 位作者 LIU Ju ZHANG Meizhu LU Hong MA Qinglin GAO Lihui 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2008年第3期585-595,共11页
The oleanane parameter, i.e., OP (oleananes/(oleananes+C30hopanes)) in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro (/%) o... The oleanane parameter, i.e., OP (oleananes/(oleananes+C30hopanes)) in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro (/%) of 0.53 in Well M1 and 0.55 in Wells H1/Hd1/Hd2, respectively. Comparing with vitrinite reflectance (Ro/%), the OP features a dynamic range and can indicate the oil generation window more precisely. By using OP and other geochemical indices, the oil-source correlation is also conducted. It suggests that the oils in wells M1 and M2 are derived from the source rocks in situ. The mudstone in Huachang uplift is not the main source rocks for oils in this area, The OP is also a useful oil-source correlation parameter in some Tertiary lacustrine basins. 展开更多
关键词 oleanane parameter (OP) BIOMARKER maturity oil-source correlation Fushan Depression
下载PDF
Origin and accumulation of high-maturity oil and gas in deep parts of the Baxian Depression, Bohai Bay Basin, China 被引量:11
18
作者 Zhao Xianzheng Jin Qiang +5 位作者 Jin Fengming Ma Peng Wang Quan Wang Jing Ren Chunling Xi Qiuling 《Petroleum Science》 SCIE CAS CSCD 2013年第3期303-313,共11页
Great quantities of light oil and gas are produced from deep buried hill reservoirs at depths of 5,641 m to 6,027 m and 190 ℃ to 201 ℃ in the Niudong-1 Well, representing the deepest and hottest commercial hydrocarb... Great quantities of light oil and gas are produced from deep buried hill reservoirs at depths of 5,641 m to 6,027 m and 190 ℃ to 201 ℃ in the Niudong-1 Well, representing the deepest and hottest commercial hydrocarbons discovered in the Bohai Bay Basin in eastern China. This discovery suggests favorable exploration prospects for the deep parts of the basin. However, the discovery raises questions regarding the genesis and accumulation of hydrocarbons in deep reservoirs. Based on the geochemical features of the hydrocarbons and characteristics of the source rocks as well as thermal simulation experiments of hydrocarbon generation, we conclude that the oil and gas were generated from the highly mature Sha-4 Member (Es4) source rocks instead of thermal cracking of crude oils in earlier accumulations. The source kitchen with abnormal pressures and karsted carbonate reservoirs control the formation of high-maturity hydrocarbon accumulations in the buried hills (i.e., Niudong-1) in conjunction with several structural-lithologic traps in the ES4 reservoirs since the deposition of the upper Minghuazhen Formation. This means the oil and gas exploration potential in the deep parts of the Baxian Depression is probably high. 展开更多
关键词 High mature oil and gas ORIGIN ACCUMULATION deep part of Baxian Depression
下载PDF
Mapping QTL underlying tuber starch content and plant maturity in tetraploid potato 被引量:4
19
作者 Jianwu Li Yihang Wang +6 位作者 Guohong Wen Gaofeng Li Zhang Li Rong Zhang Sheng Ma Jun Zhou Conghua Xie 《The Crop Journal》 SCIE CAS CSCD 2019年第2期261-272,共12页
Tuber starch content and plant maturity are two important agronomic traits of potato. To investigate the complex genetic basis of these traits in the cultivated potato, as well as the relationship between them, we dev... Tuber starch content and plant maturity are two important agronomic traits of potato. To investigate the complex genetic basis of these traits in the cultivated potato, as well as the relationship between them, we developed a linkage map in a tetraploid population of 192 clones derived from the cross Longshu 8 × Zaodabai and mapped quantitative trait loci(QTL) for tuber starch content and plant maturity using data collected in three diverse environments over two years. We detected eleven QTL for tuber starch content distributed on seven chromosomes, of which four, on chromosomes I, II, and VIII, were expressed in at least three environments. For plant maturity, we identified six QTL on chromosomes II, IV,V, VII, and XI, one of which, on chromosome V, showed LOD peaks ranging from 45.2 to 62.5 cM and explained 21.6%–26.6% of phenotypic variation was expressed in five of the six environments. Because the reproducible QTL for plant maturity and tuber starch content mapped to different chromosomes and neither overlapping QTL, nor any genetic interaction between QTL were detected, we infer that tuber starch content and plant maturity are controlled by independent genetic loci. This inference supports the prospect of breeding potato for both early maturity and high starch content. 展开更多
关键词 POTATO QTL TETRAPLOID TUBER starch content PLANT maturity
下载PDF
Distribution of sterane maturity parameters in a lacustrine basin and their control factors:A case study from the Dongying Sag,East China 被引量:4
20
作者 Chen Zhonghong Zha Ming Jin Qiang Ren Yongjun 《Petroleum Science》 SCIE CAS CSCD 2011年第3期290-301,共12页
Fifty samples from the source rocks in Member 3 and Member 4 of the Paleogene Shahejie Formation in the Bohai Bay Basin, East China, were analyzed to investigate the distribution, evolution of the molecular maturity r... Fifty samples from the source rocks in Member 3 and Member 4 of the Paleogene Shahejie Formation in the Bohai Bay Basin, East China, were analyzed to investigate the distribution, evolution of the molecular maturity ratios C29ββ/(ββ+αα) and C2920S/(20S+20R) and their control factors in the natural geological profile and sequence. The results showed that progressive changes in molecular maturity parameters are associated with major changes in thermal evolution of related biomarkers. Increases in the C29ββ/(ββ+αα) and C2920S/(20S+20R) ratios result from the difference in the relative rate between generation and thermal degradation of isomers involved. The samples from a hyper-saline environment below 3.5 km in which evaporitic rocks deposited shows high response of Sr/Ba, Sr/Ca, Fe/ Mn, Pr/n-C17, Ph/n-C18 and gammacerane and low response of Pr/Ph. There presents negative reversal of biomarker maturity C29ββ/(ββ+αα, C29ββ/(ββ+αα) and Ts/(Ts+Ym) in the samples from hypersaline environment, reflecting that the gypsum- halite have negative effect on the isomerization of biomarker and thermal evolution of organic matter. The minerals in evaporites also retard the conventional thermal indicators including vitrinite reflectance (Ro) and pyrolysis peak temperature Tmax at the depth below 3.4 km (i.e. 〉3.4 km), and these parameters also show the inhibition from overpressure in the range of 2.4-3.4 kin. This result will be helpful in the interpretation and application of molecular maturity parameters for similar saline lacustrine basins. 展开更多
关键词 C29 24-ethyl cholestane BIOMARKER thermal maturity parameters saline basins Dongying Sag
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部