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Community dynamics during de novo colonization of the nascent peri-implant sulcus 被引量:1
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作者 Tamires Pereira Dutra Nicolas Robitaille +2 位作者 Khaled Altabtbaei Shareef M.Dabdoub Purnima S.Kumar 《International Journal of Oral Science》 2025年第3期361-367,共7页
Dental implants have restored masticatory function to over 100000000 individuals,yet almost 1000000 implants fail each year due to peri-implantitis,a disease triggered by peri-implant microbial dysbiosis.Our ability t... Dental implants have restored masticatory function to over 100000000 individuals,yet almost 1000000 implants fail each year due to peri-implantitis,a disease triggered by peri-implant microbial dysbiosis.Our ability to prevent and treat peri-implantitis is hampered by a paucity of knowledge of how these biomes are acquired and the factors that engender normobiosis.Therefore,we combined a 3-month interventional study of 15 systemically and periodontally healthy adults with whole genome sequencing,finescale enumeration and graph theoretics to interrogate colonization dynamics in the pristine peri-implant sulcus.We discovered that colonization trajectories of implants differ substantially from adjoining teeth in acquisition of new members and development of functional synergies.Source-tracking algorithms revealed that this niche is initially seeded by bacteria trapped within the coverscrew chamber during implant placement.These pioneer species stably colonize the microbiome and exert a sustained influence on the ecosystem by serving as anchors of influential hubs and by providing functions that enable cell replication and biofilm maturation.Unlike the periodontal microbiome,recruitment of new members to the peri-implant community occurs on nepotistic principles.Maturation is accompanied by a progressive increase in anaerobiosis,however,the predominant functionalities are oxygen-dependent over the 12-weeks.The peri-implant community is easily perturbed following crown placement,but demonstrates remarkable resilience;returning to pre-perturbation states within three weeks.This study highlights important differences in the development of the periodontal and peri-implant ecosystems,and signposts the importance of placing implants in periodontally healthy individuals or following the successful resolution of periodontal disease. 展开更多
关键词 whole genome sequencingfinescale enu masticatory function microbial dysbiosis de novo colonization peri implantitis dental implants peri implant sulcus whole genome sequencing
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The winter magic of trees: Dormancy
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作者 郝篆香 《疯狂英语(新悦读)》 2025年第3期44-46,77,共4页
1 Trees don't create their own heat like mammals do,and they don't have warm shelters or fur coats.So how do they survive the deep freeze of winter?In a way they do hibernate(冬眠)like bears—but in trees this... 1 Trees don't create their own heat like mammals do,and they don't have warm shelters or fur coats.So how do they survive the deep freeze of winter?In a way they do hibernate(冬眠)like bears—but in trees this is called dormancy and it's pretty amazing. 展开更多
关键词 dormancy trees winter survival
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EARLY BUD BREAK and SHORT VEGETATIVE PHASE 4 integrate abscisic acid(ABA)plant hormone signaling control of grape bud dormancy
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作者 Yang Dong Muhammad Khalil-Ur-Rehman +5 位作者 Yi Zhang Liyuan Huang Haoran Li Lina Yang Huan Zheng Jianmin Tao 《Journal of Integrative Agriculture》 2025年第12期4613-4629,共17页
Bud dormancy represents a critical adaptation mechanism in perennial fruit plants,enabling survival during unfavorable environmental conditions.While this adaptive strategy is essential for plant survival and reproduc... Bud dormancy represents a critical adaptation mechanism in perennial fruit plants,enabling survival during unfavorable environmental conditions.While this adaptive strategy is essential for plant survival and reproduction,its molecular mechanisms remain incompletely understood.This study investigated two grape transcription factors:EARLY BUD BREAK(VvEBB)and SHORT VEGETATIVE PHASE 4(VvSVP4).Through heterologous transformation in poplar,the research demonstrated that VvSVP4 functions as a negative regulator of bud break,while VvEBB serves as a positive regulator.Transcriptome analysis revealed significant enrichment of plant hormone signaling pathways particularly ABA,IAA,and CK in plants overexpressing VvSVP4(VvSVP4-OE)and VvEBB(VvEBB-OE)compared to controls.Endogenous hormone level changes correlated positively with transcriptome data.During endodormancy,VvSVP4 directly and positively regulated the ABA receptor gene Vv PYL9 expression,maintaining bud dormancy.Conversely,during ecodormancy,rapid upregulation of VvEBB negatively regulated the expression of sucrose nonfermenting 1-related protein kinase 2 gene(Vv SAPK2),facilitating dormancy release.This study provides comprehensive insights into how VvSVP4 and VvEBB genes regulate dormancy and bud break through cell cycle regulation and multiple hormone signaling pathways. 展开更多
关键词 bud dormancy cell cycle GRAPE HORMONE VvSVP4 VvEBB
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Tumor dormancy and relapse:understanding the molecular mechanisms of cancer recurrence
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作者 Muhammad Tufail Can-Hua Jiang Ning Li 《Military Medical Research》 2025年第9期1456-1491,共36页
Cancer recurrence,driven by the phenomenon of tumor dormancy,presents a formidable challenge in oncology.Dormant cancer cells have the ability to evade detection and treatment,leading to relapse.This review emphasizes... Cancer recurrence,driven by the phenomenon of tumor dormancy,presents a formidable challenge in oncology.Dormant cancer cells have the ability to evade detection and treatment,leading to relapse.This review emphasizes the urgent need to comprehend tumor dormancy and its implications for cancer recurrence.Despite notable advancements,significant gaps remain in our understanding of the mechanisms underlying dormancy and the lack of reliable biomarkers for predicting relapse.This review provides a comprehensive analysis of the cellular,angiogenic,and immunological aspects of dormancy.It highlights the current therapeutic strategies targeting dormant cells,particularly combination therapies and immunotherapies,which hold promise in preventing relapse.By elucidating these mechanisms and proposing innovative research methodologies,this review aims to deepen our understanding of tumor dormancy,ultimately facilitating the development of more effective strategies for preventing cancer recurrence and improving patient outcomes. 展开更多
关键词 Tumor dormancy Cancer recurrence Signaling pathways Biomarkers Therapeutic approaches
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Metabolic Profile Analysis and Key Metabolic Pathways Identification in Different Embryo Parts Regulating Dormancy and Germination in Pinus koraiensis
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作者 Xinghuan Li Binxi Hao +2 位作者 Shimin Cheng Ju Zhang Yuan Song 《Phyton-International Journal of Experimental Botany》 2025年第8期2499-2513,共15页
Pinus koraiensis is the dominant and constructive species of the zonal vegetation in Northeast China,known as the mixed broadleaf-Korean pine forest.Although carbohydrate metabolism pathways in the seed embryo are kno... Pinus koraiensis is the dominant and constructive species of the zonal vegetation in Northeast China,known as the mixed broadleaf-Korean pine forest.Although carbohydrate metabolism pathways in the seed embryo are known to play crucial roles during seed dormancy and germination in P.koraiensis,it remains unclear whether these metabolic pathways function differentially across tissues.P.koraiensis seeds that had undergone different durations of moist chilling in their natural environment,yielding seeds with relatively deeper primary physiological dormancy(DDS)and seeds with released primary physiological dormancy(RDS).A non-targeted metabolomic analysis was conducted on the radicle and hypocotyl-cotyledon portions of both DDS and RDS,before and after a two-week incubation under favorable conditions.Under germination conditions,RDS and DDS showed divergent metabolic profiles,especially regarding carbohydrate metabolism.Specifically,RDS seeds showed significantly reduced substrates of respiratory metabolic pathways in both radicles and hypocotyl-cotyledons.Conversely,the intermediates of the carbohydrate metabolism pathway(particularly the tricarboxylic acid cycle)accumulating in radicles of DDS seeds under germination conditions.Moreover,in RDS,the carbohydrate metabolic pathways were more prevalent in the hypocotyl-cotyledon,while lysine degradation and ascorbate and aldarate metabolism were the dominant metabolic pathways in radicles.In contrast,the tricarboxylic acid cycle showed higher activity in DDS radicles compared to hypocotyl-cotyledons.We further demonstrated that carbohydratemetabolic pathways continue to play a dominant role in both dormancy maintenance and germination processes of P.koraiensis seeds.Notably,the carbohydratemetabolism in radicles likely exerts more critical regulatory functions in these two physiological processes compared to that in cotyledon and hypocotyl tissues. 展开更多
关键词 Seed germination seed dormancy metabolism RADICLE hypocotyl-cotyledon Pinus koraiensis
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ZmL75 is required for colonization by arbuscular mycorrhizal fungi and for saline-alkali tolerance in maize
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作者 Jie Liu Boming Yang +9 位作者 Xunji Chen Tengfei Zhang Huairen Zhang Yimo Du Qian Zhao Zhaogui Zhang Darun Cai Juan Liu Huabang Chen Li Zhao 《Journal of Genetics and Genomics》 2025年第3期334-345,共12页
Saline-alkali soil severely reduces the productivity of crops,including maize(Zea mays).Although several genes associated with saline-alkali tolerance have been identified in maize,the underlying regulatory mechanism ... Saline-alkali soil severely reduces the productivity of crops,including maize(Zea mays).Although several genes associated with saline-alkali tolerance have been identified in maize,the underlying regulatory mechanism remains elusive.Here,we report a direct link between colonization by arbuscular mycorrhizal fungi(AMF)and saline-alkali tolerance in maize.We identify s75,a natural maize mutant that cannot survive under moderate saline-alkali soil conditions or establish AM symbioses.The saline-alkali hypersensitive phenotype of s75 is caused by a 1340-bp deletion in Zm00001d033915,designated as ZmL75.This gene encodes a glycerol-3-phosphate acyltransferase localized in the endoplasmic reticulum,and is responsible for AMF colonization.ZmL75 expression levels in roots correspond with the root length colonization(RLC)rate during early vegetative development.Notably,the s75 mutant line shows a complete loss of AMF colonization,along with alterations in the diversity and structure of its root fungal microbiota.Conversely,overexpression of ZmL75 increases the RLC rate and enhances tolerance to saline-alkali soil conditions.These results suggest that ZmL75 is required for symbiosis with AMF,which directly improves saline-alkali tolerance.Our findings provide insights into maize-AMF interactions and offer a potential strategy for maize improvement. 展开更多
关键词 MAIZE SALINE-ALKALI ZmL75 AMF colonization TOLERANCE
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Inoculation and Colonization:British Medical Activities in Xizang and Their Significance(1900-1907)
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作者 TANG Yiyun 《Cultural and Religious Studies》 2025年第3期131-134,共4页
In the early years of the 20th century,Britain sought to compete with Russia for dominance in East Asia,and set its sights on the strategic location of Xizang.Smallpox virus epidemics have been documented in Xizang si... In the early years of the 20th century,Britain sought to compete with Russia for dominance in East Asia,and set its sights on the strategic location of Xizang.Smallpox virus epidemics have been documented in Xizang since the 7th century,and smallpox remained a major public health issue in Xizang until the early 20th century.The British colonizers learned from their experience of passing on biological science and technology in India and carried out a series of medical activities in Xizang,the most influential of which was the smallpox vaccination for the people of Gyantse and other places.This paper examines the history of the fight against smallpox in Xizang from 1900 to 1907,and studies the historical process of British colonial expansion in Xizang,as well as the interaction between the Qing government and the British invaders in medical and healthcare events such as vaccination in Xizang. 展开更多
关键词 smallpox vaccination British colonization Xizang Qing government medical diplomacy
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Case report:minimally invasive management of two major complications of colonic perforation and pseudoaneurysm formation following nephrostomy tube placement
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作者 Marie-Lou Letouche Aideen Madden +2 位作者 Mariela Corralles Steeve Doizi Olivier Traxer 《The Canadian Journal of Urology》 2026年第1期227-232,共6页
Background:We present a case of two major complications following insertion of a nephrostomy managed in a minimally invasive way.Our case is the first in the literature to describe this minimally invasive treatment te... Background:We present a case of two major complications following insertion of a nephrostomy managed in a minimally invasive way.Our case is the first in the literature to describe this minimally invasive treatment technique for colon perforation in a completely asymptomatic patient.Case Description:A 75-year-old female patient with a history of bilateral obstructive uropathy secondary to bilateral radiation-induced ureteric strictures attended for bilateral nephrostomy placement.The patient had a history of endometrial cancer,treated previously by total hysterectomy and bilateral salpingo-oophorectomy with adjuvant chemo-radiotherapy and brachytherapy.Her recovery had been further complicated by the development of radiation cystitis,small bowel resection,and short gut syndrome.The strictures had previously been managed with bilateral double J stents,which have now failed.A left-sided nephrostomy insertion was performed.ACT-scan prompted by a repeat deterioration in renal function revealed a right-sided hydronephrosis and suggested transcolic passage of the previously placed leftsided nephrostomy.She had remained clinically well and apyretic.A right-sided nephrostomy was inserted,and the left re-sited following a colonoscopy-guided nephrostomy removal and clip occlusion of the nephrostomy tract.The patient then developed a pseudoaneurysm,which was managed with embolization.The patient was able to return home with corrected kidney function.The three-monthly checks for changes in nephrostomy catheters did not reveal any complications.Conclusions:The patient therefore presented with two major complications of nephrostomy placement:colonic perforation and pseudoaneurysm,classified as Clavien IIIb and IIIa,respectively.Multidisciplinary management,including urologists,gastroenterologists,general surgeons,and radiologists,enabled a minimally invasive management.Minimally invasive management with endoscopic clip placement appears to be a safe alternative to directed fistula of colonic perforation. 展开更多
关键词 NEPHROSTOMY colonic injuries conservative treatment PSEUDOANEURYSM EMBOLIZATION
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Dietary supplementation with sodium isobutyrate enhances growth performance and colonic barrier function in weaned piglets via microbiota-metabolite-host interactions
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作者 Xiuyu Fang Zihan Chi +6 位作者 Zhengyi Wang Xinlin Wang Xingrui Qu Shuang Zhang Feng Gao Baoming Shi Xuan Zhao 《Journal of Animal Science and Biotechnology》 2026年第1期404-425,共22页
Background Weaning-induced diarrhoea and growth retardation in piglets are associated with impaired intestinal barrier function and decreased levels of colonic short-chain fatty acids(SCFAs).Although SCFA supplementat... Background Weaning-induced diarrhoea and growth retardation in piglets are associated with impaired intestinal barrier function and decreased levels of colonic short-chain fatty acids(SCFAs).Although SCFA supplementation has been proposed to mitigate these issues,the efficacy and optimal dosage of sodium isobutyrate remain unclear.Results We investigated the effects of sodium isobutyrate supplementation(500,1,000,2,000,and 4,000 mg/kg diet)on weaned piglets(Duroc×Landrace×Yorkshire,28 d of age;n=8).After a 28-d feeding trial,supplementation at 500–2,000 mg/kg significantly improved average daily gain and feed efficiency and reduced diarrhoea frequency,with maximal benefits observed at 1,000 mg/kg(P<0.0001).Additionally,500–1,000 mg/kg sodium isobutyrate supplementation increased the apparent digestibility of crude protein,organic matter,and crude fibre(P<0.05).Serum biochemical parameters were unaffected,although secretory immunoglobulin A(SIgA)levels significantly increased upon supplementation with 500–1,000 mg/kg(P<0.05).16S rRNA gene sequencing indicated that sodium isobutyrate increased the abundance of beneficial colonic microbiota.The 1,000 mg/kg group presented the most pronounced effect,with a significant increase of the relative abundance of Prevotella and the greatest improvement in SCFA concentrations(P<0.05).Metabolomics revealed elevated levels of colonic indole-3-lactic acid and 3-hydroxybutyrate upon supplementation with 1,000 mg/kg(P<0.05).Transcriptomic analyses indicated activation of protein digestion and absorption pathways,and PI3K-Akt signalling,marked by TSG-6 upregulation and the suppression of ISG15 and DDIT4 expression(P<0.05).Supplementation with 1,000 mg/kg was associated with improved intestinal barrier-related markers,including reduced serum D-lactate,diamine oxidase,and lipopolysaccharide levels,increased tight junction protein expression;activation of G protein-coupled receptors;and inhibition of TLR4/MyD88/NF-κB signalling(P<0.05),suggesting enhanced barrier function.Conclusions In conclusion,dietary supplementation with 1,000 mg/kg sodium isobutyrate was associated with improved intestinal morphology,reduced serum permeability,increased expression of tight junction proteins,and enhanced immune function in weaned piglets,suggesting enhanced colonic barrier function and providing dosage guidance and mechanistic insights for future applications. 展开更多
关键词 colonic barrier function DIARRHOEA Intestinal microbiota Sodium isobutyrate Weaned piglets
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Unusual recurrence of colon cancer with isolated axillary lymph node metastasis:A case report
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作者 Ali Toffaha Mahmood Al-Dhaheri +5 位作者 Mohammad AL.Zoubi Arwa Abdelrahim Mahir Petkar Ahmed Badr Mohamed Abunada Ayman Ahmed 《Laparoscopic, Endoscopic and Robotic Surgery》 2026年第1期58-61,共4页
The metastatic pattern of colon cancer is typically well characterized,with initial dissemination occurring through regional lymphatics,followed by hematogenous spread.The most frequent sites of metastasis in colorect... The metastatic pattern of colon cancer is typically well characterized,with initial dissemination occurring through regional lymphatics,followed by hematogenous spread.The most frequent sites of metastasis in colorectal cancer(CRC)include regional lymph nodes(50%–70%),liver(35%–50%),lungs(21%),peritoneum(15%),and ovaries(13%).1 Isolated distant lymph node metastasis,particularly in the absence of concurrent systemic disease,is exceedingly rare in CRC.To date,only six cases of isolated axillary lymph node metastasis(ALNM)from colorectal primaries have been documented in the literature.1–6 Even more uncommon is the incidental discovery of malignant cells in anastomotic doughnuts following stoma reversal procedures.Herein,we report a rare case involving both the incidental histopathological detection of tumor cells within doughnuts during stoma closure and the subsequent development of isolated ALNM after curative resection of sigmoid colon carcinoma. 展开更多
关键词 axillary lymph node hematogenous spreadthe axillary lymph node metastasis distant lymph node metastasisparticularly colon cancer regional lymph nodes liver lungs peritoneum colorectal cancer crc include regional lymphaticsfollowed
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Effect of Different Soak Treatments on Breaking Seed Dormancy in Soil Seed Bank from Different Degraded Grasslands 被引量:6
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作者 魏学红 格桑卓玛 《Agricultural Science & Technology》 CAS 2010年第8期173-175,共3页
[Objective] The aim was to study the effect of different soak treatments on breaking seed dormancy in soil seed bank from different degraded grasslands. [Method] Different concentrations of H2SO4,GA3 and KNO3 were use... [Objective] The aim was to study the effect of different soak treatments on breaking seed dormancy in soil seed bank from different degraded grasslands. [Method] Different concentrations of H2SO4,GA3 and KNO3 were used for soaking the seeds in the soil seed bank from different degraded grasslands,and the germination number of seeds was detected. [Result] When the seeds from soil seed bank were soaked with 60%,70%,80% and 90% H2SO4,the germination number of seeds was 0,indicating that the germination of seeds was inhibited; when the seeds were soaked with GA3,the germination number of seeds increased with the concentration of GA3 increasing. When the concentration of GA3 increased to 0.10%,the germination of seeds was inhibited; when the seeds were soaked with 0.2% KNO3,the germination number of seeds was greater than the blank control. [Conclusion] The number of remaining seeds was more in the soil seed banks collected from moderately degraded grassland and heavily degraded grassland; while the number of remaining seeds was small in the soil seed banks collected from lightly degraded grassland and extremely degraded grassland. 展开更多
关键词 Different degraded grasslands Soil seed bank Soak dormancy
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Colonization Pattern of Azospirillum brasilense Yu62 on Maize Roots 被引量:7
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作者 刘元 陈三凤 李季伦 《Acta Botanica Sinica》 CSCD 2003年第6期748-752,共5页
Plasmid pVK1001 which carried the gfp gene of GFPmut2, a mutant of GFP, was introduced into Azospirillum brasilense Yu62 by electroporation. Maize seedlings were inoculated with the GFP-labelled baeteria and grown gno... Plasmid pVK1001 which carried the gfp gene of GFPmut2, a mutant of GFP, was introduced into Azospirillum brasilense Yu62 by electroporation. Maize seedlings were inoculated with the GFP-labelled baeteria and grown gnotobiotically in flask with semi-solid agar medium. Observations were performed with confocal laser scanning microscopy (CLSM) and electron microscopy, respectively, at 8 d and 12 d after inoculation. Confocal laser scanning microscopy showed that A. brasilense Yu62 could penetrate into the cortex tissue, colonizing in the intercellular spaces of the parenchyma cells of the cortex tissue. Transmission and scanning electron microscopy (TEM) showed that the majority of the bacteria colonized on the root surface and only a minority of them resided in the root interior. 展开更多
关键词 green fluorescent protein (GFP) Azospirillum brasilense Yu62 colonization confocal laser scanning microscopy ( CLSM) transmission electron microscopy (TEM) scanning electron microscopy (SEM)
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Study on Characters of Hard Seeds of Amphicarpaea edgeworthii Benth. (Leguminosae) and Methods for Breaking Dormancy
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作者 张立峰 吴兴文 佘跃辉 《Agricultural Science & Technology》 CAS 2012年第9期1885-1890,共6页
[Objective] This study aimed to understand the characters of hard seeds of Amphicarpaea edgeworthii Benth. (Leguminosae) and explore the methods for break- ing dormancy. [Method] For both aerial and subterranean see... [Objective] This study aimed to understand the characters of hard seeds of Amphicarpaea edgeworthii Benth. (Leguminosae) and explore the methods for break- ing dormancy. [Method] For both aerial and subterranean seeds of A. edgeworthii, the morphological characteristics were observed and the appropriate temperature for germination was explored. For aerial seeds of A. edgeworthii, the characters of hard seeds were studied, and concentrated sulfuric acid treatment, hot water soak treat- ment and mechanical damage treatment were compared to explore the methods for breaking seed dormancy. [Result] The aerial seeds were oblate and averaged 3.38 mm in length, 3.02 mm in width, 1.88 mm in thickness, 15.32 g in thousand grain weight, with a hard seed rate after of up to 98% natural maturation. The subter- ranean seeds were approximately oblate with a maximum diameter of 15 mm and a hundred grain weight of (50.08-58.26 g); among all the treatments for breaking hardseededness, cutting seed coat treatment and concentrated sulfuric acid treatment for 20 minutes were the most effective methods, whereas hot water soak treatment was the least effective method; constant temperature between 20 and 30 ℃ was optimum for the germination of aerial seeds, and alternative temperature of 30/20 ℃ was most appropriate for the germination of subterranean seeds. [Conclusion] Cutting seed coat treatment and concentrated sulfuric acid treatment for 20 minutes were the most effective methods to break the hardseededness of A. edgeworthii. 展开更多
关键词 Amphicarpaea edgeworthii Benth. (Leguminosae) Breaking dormancy GERMINATION Hardseededness SEEDS
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Research Progress of Molecular Regulation Mechanism of Seed Dormancy 被引量:5
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作者 黄玲玲 张得芳 夏涛 《Agricultural Science & Technology》 CAS 2016年第4期786-791,848,共7页
Dormancy is the biological adaptation behavior for seed, and it is regulated by many factors. A lot of studies have been done on various aspects of seed dormancy, and the breadth and width of these studies are in cons... Dormancy is the biological adaptation behavior for seed, and it is regulated by many factors. A lot of studies have been done on various aspects of seed dormancy, and the breadth and width of these studies are in constant expanding and deepening. With the wide application of means of quantitative genetics method and mutant in the study on seed dormancy, a large number of quantitative trait loci(QTL) and mutant genes related with dormancy have been identified, which is of great significance for the further revelation of the detail mechanisms of plant seed dormancy and germination. This paper briefly introduced the genetic variation of seed dormancy in recent years, described the inductive formation of plant seed dormancy from the four aspects of dormancy specific gene, chromatin, seed growth development and hormone, and stated the action mechanism of environmental factors on seed dormancy from genetic and molecular levels, as well as the regulation and control mechanism of dormancy release, with the aim to provide certain references for the study on seed dormancy. 展开更多
关键词 Seed dormancy MUTANT QTL CONTROL
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Effect of different seed treatments on dormancy breaking and germination in three species in arid and semi-arid lands 被引量:11
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作者 Seyed Mohammad Hosseini NASR Sekineh Kiani SAVADKOOHI Elahe AHMADI 《Forestry Studies in China》 CAS 2013年第2期130-136,共7页
Seeds of many woody plant species have one of several types of dormancy. They do not germinate unless ,specific environmental signals are in place or events occur. This study was conducted to evaluate the effects of s... Seeds of many woody plant species have one of several types of dormancy. They do not germinate unless ,specific environmental signals are in place or events occur. This study was conducted to evaluate the effects of scarification treatments on seed dormancy and germination of Acacia nilotica (L.) Willd. ex Del., Prosopis juliflora (Sw.) DC. :and Dodonaea viscosa (L.) Jacq. The following treatments were applied: T1, untreated seed (control); T2, sulphuric acid (97%) for 45 min; T3, boiling water for 5 min. The seeds were cultured on a Murashige and Skoog (MS) medium after sterilization. The responses of seeds to treatments were compared with each other and with the control treatment. Germination was observed daily for a 30-day period. Results indicated positive responses to treatments, while impermeable Seed coats may be responsible for low germination rates in intact seeds as seen experimentally in the untreated control. The highest germination was obtained for P. juliflora and D. viscosa acid-scarified seeds (80.8%-90.8%) and for scarified seeds of A. nilotica (50.2%) boiled in water. The germination indices, i.e., final germination percentage (FG), mean daily germination (MDG) and germination rate (GR), were significantly affected by treatments and species (p 〈 0.01). 展开更多
关键词 GERMINATION MEDIUM PRETREATMENT seed dormancy
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Changes in the biochemical composition and enzyme activity during dormancy release of Cyclocarya paliurus seeds 被引量:12
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作者 Fang Sheng-zuo Wang Jia-yuan 《Forestry Studies in China》 CAS 2007年第1期7-13,共7页
Cyclocarya paliurus is only propagated from seeds which have pronounced dormancy. Overcoming seed dormancy is an important component of efficient and cost-effective seedling production of Cyclocarya paliurus. Changes ... Cyclocarya paliurus is only propagated from seeds which have pronounced dormancy. Overcoming seed dormancy is an important component of efficient and cost-effective seedling production of Cyclocarya paliurus. Changes in biochemical composition and enzyme activity were investigated during dormancy release. The activities of all the studied enzymes in the stratified seeds increased significantly, compared to those in the control samples. Of the enzymes examined, the activities of protease increased the most (413.8%), followed by peroxidase (278.7%), lipase (161.0%), glucose-6-phosphate dehydrognase (149.1%) and amylase (60.6%) after 8 months of stratification. Crude fat and protein constituted the bulk of the storage reserves in mature seeds of C. pal# urus. Compared with the seeds before stratification, about 45% of the starch, 46% of the protein and 11% of the crude fat were depleted during dormancy release of C. paliurus seeds, while the soluble sugar content was enhanced by 101.5% in the germinating seeds. Correlation analysis showed, during dormancy release of C. paliurus seeds, a close positive relationship between POD and G6PDH activity as well as soluble sugar content and amylase activity, while there was a significant negative relationship between storage substances and their related enzyme activities. 展开更多
关键词 Cyclocaryapaliurus enzyme activity seed dormancy soluble sugar storage substances STRATIFICATION
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Seed dormancy and germination characteristics of two Rheum species in the Himalaya-Hengduan Mountains 被引量:5
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作者 Deli Peng Zhe Chen +3 位作者 Xiaojian Hu Zhimin Li Bo Song Hang Sun 《Plant Diversity》 SCIE CAS CSCD 北大核心 2017年第4期180-186,共7页
Seed dormancy and germination characteristics are important factors determining plant reproductive success, and may be expected to have a major influence on plant distribution. In this study, we aimed to explore the c... Seed dormancy and germination characteristics are important factors determining plant reproductive success, and may be expected to have a major influence on plant distribution. In this study, we aimed to explore the characteristics of seed dormancy and germination in two endemic Rheum species(Rheum nobile and Rheum alexandrae) in the Himalaya-Hengduan Mountains. To determine the type of dormancy,fresh seeds of the two species(one population each) were incubated in light at 25/15 and 15/5℃, and then dry after-ripening(DAR) seeds were incubated on water agar substrate with or without GA_3. To determine the effect of temperature and light on germination, DAR seeds of the two species(two populations each) were incubated both in the light and in the dark at several temperatures, including constant and alternating temperatures. Base temperature(T_b) and thermal times for 50% germination(θ_(50)) were calculated. DAR released physiological dormancy(PD), increasing final germination at 15/5℃ and widening the range of germination temperatures from higher to lower, indicative of type 2 non-deep PD for the two Rheum species. Light had no significant effect on germination of seeds from the two species(two populations each). Seeds of the two species germinated significantly better(>80%) at medium temperatures(10-25℃) than at extreme low(5℃) or high(35℃) temperatures. Alternating temperatures(25/15 and 15/5℃) did not significantly increase the final germination of the two species either in the light and in the dark, but it promoted seed germination more quickly than corresponding constant temperatures in the light in both Rh. alexandrae populations, especially at 15/5℃. Germination in response to temperature was well described by the thermal-time model at suboptimal temperatures. The estimated Tbvalues were 1 and 0.9℃, respectively, in two Rh. nobile populations; 4 and 4.1℃,respectively, in two Rh. alexandrae populations; θ_(50)(thermal time) were 100 and 125℃d, respectively in two Rh. nobile populations; 76.92 and 83.33℃d, respectively in two Rh. alexandrae populations. The dormancy type, and germination responses to temperature and light condition does not explain why the two Rheum species are distributed in contrasting habitats. However, these findings reflect an advantageous germination strategy of these two Rheum species to adapt to the same alpine environments. 展开更多
关键词 GERMINATION LIGHT Rheum alexandrae Rheum nobile dormancy Temperature
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Factors that mediate colonization of the human stomach by Helicobacter pylori 被引量:9
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作者 Ciara Dunne Brendan Dolan Marguerite Clyne 《World Journal of Gastroenterology》 SCIE CAS 2014年第19期5610-5624,共15页
Helicobacter pylori(H.pylori)colonizes the stomach of humans and causes chronic infection.The majority of bacteria live in the mucus layer overlying the gastric epithelial cells and only a small proportion of bacteria... Helicobacter pylori(H.pylori)colonizes the stomach of humans and causes chronic infection.The majority of bacteria live in the mucus layer overlying the gastric epithelial cells and only a small proportion of bacteria are found interacting with the epithelial cells.The bacteria living in the gastric mucus may act as a reservoir of infection for the underlying cells which is essential for the development of disease.Colonization of gastric mucus is likely to be key to the establishment of chronic infection.How H.pylori manages to colonise and survive in the hostile environment of the human stomach and avoid removal by mucus flow and killing by gastric acid is the subject of this review.We also discuss how bacterial and host factors may together go some way to explaining the susceptibility to colonization and the outcome of infection in different individuals.H.pylori infection of the gastric mucosa has become a paradigm for chronic infection.Understanding of why H.pylori is such a successful pathogen may help us understand how other bacterial species colonise mucosal surfaces and cause disease. 展开更多
关键词 Helicobacter pylori colonization Infection Gastric mucosa UREASE FLAGELLA Polymorphisms ADHESINS CAGA Type IV secretion system
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Overcoming seed dormancy of mooseer(Allium hirtifolium) through cold stratification,gibberellic acid,and acid scarification 被引量:3
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作者 Farshad Dashti Hojat Ghahremani-Majd Mahmood Esna-Ashari 《Journal of Forestry Research》 CAS CSCD 2012年第4期707-710,共4页
Mooseer (Allium hirtifolium Boiss.) is bulbous perennial herb widely used in pharmaceutical and food industry in Iran. We studied germination of mooseer seeds in two separate experiments. In the first experiment, we... Mooseer (Allium hirtifolium Boiss.) is bulbous perennial herb widely used in pharmaceutical and food industry in Iran. We studied germination of mooseer seeds in two separate experiments. In the first experiment, we evaluated four treatments: sulfuric acid scarification, sandpaper scarification, cold stratification, and gibberellic acid (GA3) application. In the second experiment, we evaluated combinations of these treatments. All treatments in the first experiment had no effect on seed germination, suggesting that mooseer seeds have physical and physiological dormancy. In the second experiment, the highest germina- tion percentage (86.6%) was observed after five minutes scarification with sulfuric acid (75% v/v), followed by 60 days of cold stratification. Duration of sulfuric acid scarification (5, 10, and 20 min) did not affect germination rates, but increasing duration of cold stratification (from 15 to 60 days), increased germination from 28.3% to 86.6%. Our study showed that mooseer seeds have both physical and physiological dormancy. 展开更多
关键词 physical dormancy physiological dormancy GERMINATION sulfuric acid sand paper Allium hirtifolium
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Maternal imprinting of the neonatal microbiota colonization in intrauterine growth restricted piglets:a review 被引量:7
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作者 Lili Jiang Cuiping Feng +4 位作者 Shiyu Tao Na Li Bin Zuo Dandan Han Junjun Wang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2020年第1期1-8,共8页
Early colonization of intestinal microbiota during the neonatal stage plays an important role on the development of intestinal immune system and nutrients absorption of the host.Compared to the normal birth weight(NBW... Early colonization of intestinal microbiota during the neonatal stage plays an important role on the development of intestinal immune system and nutrients absorption of the host.Compared to the normal birth weight(NBW)piglets,intrauterine growth restricted(IUGR)piglets have a different intestinal microbiota during their early life,which is related to maternal imprinting on intestinal microbial succession during gestation,at birth and via suckling.Imbalanced allocation of limited nutrients among fetuses during gestation could be one of the main causes for impaired intestinal development and microbiota colonization in neonatal IUGR piglets.In this review,we summarized the potential impact of maternal imprinting on the colonization of the intestinal microbiota in IUGR piglets,including maternal undernutrition,imbalanced allocation of nutrients among fetuses,as well as vertical microbial transmission from mother to offspring during gestation and lactation.At the same time,we give information about the current maternal nutritional strategies(mainly breastfeeding,probiotics and prebiotics)to help colonization of the advantageous intestinal microbiota for IUGR piglets. 展开更多
关键词 IUGR PIGLET Microbial colonization MATERNAL IMPRINTING Nutritional intervention
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