全文获取类型
收费全文 | 207篇 |
免费 | 18篇 |
专业分类
林业 | 17篇 |
农学 | 8篇 |
基础科学 | 1篇 |
47篇 | |
综合类 | 12篇 |
农作物 | 24篇 |
水产渔业 | 30篇 |
畜牧兽医 | 56篇 |
园艺 | 5篇 |
植物保护 | 25篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 8篇 |
2021年 | 16篇 |
2020年 | 8篇 |
2019年 | 16篇 |
2018年 | 14篇 |
2017年 | 15篇 |
2016年 | 12篇 |
2015年 | 7篇 |
2014年 | 13篇 |
2013年 | 16篇 |
2012年 | 11篇 |
2011年 | 19篇 |
2010年 | 11篇 |
2009年 | 10篇 |
2008年 | 8篇 |
2007年 | 6篇 |
2006年 | 8篇 |
2005年 | 6篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1994年 | 1篇 |
排序方式: 共有225条查询结果,搜索用时 0 毫秒
31.
Samira Gilanchi Banafshe Esmaeilzade Akram Eidi Mahmood Barati Soraya Mehrabi Fatima Moghani Ghoroghi Maliheh Nobakht 《Iranian Biomedical Journal》2014,18(3):136-142
Background: The seladin-1 (selective Alzheimer disease indicator-1), also known as DHCR24, is a gene found to be down-regulated in brain region affected by Alzheimer disease (AD). Whereas, hair follicle stem cells (HFSC), which are affected in with neurogenic potential, it might to hypothesize that this multipotent cell compartment is the predominant source of seladin-1. Our aim was to evaluate seladin-1 gene expression in hair follicle stem cells. Methods: In this study, bulge area of male Wistar rat HFSC were cultured and then characterized with Seladin-1 immunocytochemistry and flow cytometry on days 8 to 14. Next, 9-11-day cells were evaluated for seladin-1 gene expression by real-time PCR. Results: Our results indicated that expression of the seladin-1 gene (DHCR24) on days 9, 10, and 11 may contribute to the development of HFSC. However, the expression of this gene on day 11 was more than day 10 and on 10th day was more than day 9. Also, we assessed HFSC on day 14 and demonstrated these cells were positive for β-ш tubulin, and seladin-1 was not expressed in this day. Conclusion: HFSC express seladin-1 and this result demonstrates that these cells might be used to cell therapy for AD in future. Key Words: Seladin-1 (selective Alzheimer disease indicator-1), Alzheimer disease (AD), Hair follicle stem cells 相似文献
32.
Mohammed F. Aldawsari Mohammed Muqtader Ahmed Farhat Fatima Md. Khalid Anwer Prakash Katakam Abdullah Khan 《Marine drugs》2021,19(8)
The objective of this work was to develop sustained-release Ca-alginate beads of apigenin using sodium alginate, a natural polysaccharide. Six batches were prepared by applying the ionotropic gelation technique, wherein calcium chloride was used as a crosslinking agent. The beads were evaluated for particle size, drug loading, percentage yield, and in vitro drug release. Particle size was found to decrease, and drug entrapment efficiency was enhanced with an increase in the polymer concentration. The dissolution study showed sustained drug release from the apigenin-loaded alginate beads with an increase in the polymer proportion. Based on the dissolution profiles, BD6 formulation was optimized and characterized for FTIR, DSC, XRD, and SEM, results of which indicated successful development of apigenin-loaded Ca alginate beads. MTT assay demonstrated a potential anticancer effect against the breast cancer MCF-7 cell lines. The antimicrobial activity exhibited effective inhibition in the bacterial and fungal growth rate. The DPPH measurement revealed that the formulation had substantial antioxidant activity, with EC50 value slightly lowered compared to pure apigenin. A stability study demonstrated that the BD6 was stable with similar (f2) drug release profiles in harsh condition. In conclusion, alginate-based beads could be used for sustaining the drug release of poorly water-soluble apigenin while also improving in vitro antitumor, antimicrobial, and antioxidant activity. 相似文献
33.
We studied seed morphometric characters, oil content and azadirachtin content in a medicinally important and insect repellent tree species Azadirachta indica A.Juss. Ten populations were selected from two central Indian states of Madhya Pradesh and Chhattisgarh and twenty candidate plus trees were selected from each population based on tree attributes. Azadirachtin content was estimated in seeds, in vitro shoots and callus cultures through HPLC. Significant variation(p \ 0.05) was observed in seed morphometric characters, oil content and azadirachtin content among the ten populations. Maximum value for 100 seed weight was obtained in seeds of Raigarh(30.51 g) which was on par with seeds of Bargi(28.37 g)and Chhatarpur(26.36 g). The ratio of highest kernel to seed was also obtained in seeds of Raigarh(60.11%).Kernels from Chhatarpur population recorded the highest oil content(24.20%), which was equal to that in Sihore(23.75%) and Katni(21.75%). We recorded highly significant variation in azadirachtin content in seed samples,in vitro shoot samples and callus cultures. Maximum azadirachtin was present in the seeds of Gwalior(0.882%)which was on par with azadirachtin content in seeds of Chhatarpur, Katni, Sihore, Shahdol and Chhindwara.Maximum azadirachtin in the in vitro shoots was present in the cultures of Gwalior(0.218%) which was statistically on par with Sihore(0.176%). Similarly, in callus cultures of nodal segments maximum azadirachtin was recorded in the Gwalior population(0.033%) which was statistically on par with Sihore(0.028%). The trees of Gwalior and Sihore populations can be produced in large numbers through vegetative propagation to obtain seeds with higher azadirachtin content. 相似文献
34.
Relationships between Quarter Milk Cell Count (QMCC) and Tank Milk Cell Count (TMCC) with milk biochemical and technological parameters in milk and dairy products were investigated. All parameters measured were affected by the increase of TMCC and QMCC between 0 and 600 000 cells/mL. The variable effect of lactation stage which is different for different authors, is discussed. The three mechanisms, measured during the inflammation of the udder, implicated in the modification of milk quality are described (a decrease in synthesis, a decrease in the milk barrier permeability and an increase in proteolytic activities). The direct effect of plasmin in caseinolysis is well known; the specific role of the increase of somatic cells (especially PMN) in the modification of milk quality is described. Several specific proteolytic activities of PMN are described and the impact of these activities on caseinolysis is evaluated. Two hypothetical mechanisms of caseinolysis by PMN are suggested and a synthetic scheme of the role of plasmin, bacteria and somatic cells in caseinolysis is discussed. 相似文献
35.
Miriam Sanz Ana Paula Dini Andreote Marli Fatima Fiore Felipe Augusto D?rr Ernani Pinto 《Marine drugs》2015,13(6):3892-3919
Cyanobacteria from underexplored and extreme habitats are attracting increasing attention in the search for new bioactive substances. However, cyanobacterial communities from tropical and subtropical regions are still largely unknown, especially with respect to metabolite production. Among the structurally diverse secondary metabolites produced by these organisms, peptides are by far the most frequently described structures. In this work, liquid chromatography/electrospray ionization coupled to high resolution quadrupole time-of-flight tandem mass spectrometry with positive ion detection was applied to study the peptide profile of a group of cyanobacteria isolated from the Southeastern Brazilian coastal forest. A total of 38 peptides belonging to three different families (anabaenopeptins, aeruginosins, and cyanopeptolins) were detected in the extracts. Of the 38 peptides, 37 were detected here for the first time. New structural features were proposed based on mass accuracy data and isotopic patterns derived from full scan and MS/MS spectra. Interestingly, of the 40 surveyed strains only nine were confirmed to be peptide producers; all of these strains belonged to the order Nostocales (three Nostoc sp., two Desmonostoc sp. and four Brasilonema sp.). 相似文献
36.
The distribution of FCoV Types I and II in a Portuguese cat population was studied by a RT-PCR assay targeting the 3′-end of the viral RNA. For a period of 3 years, 120 samples were collected and 57 were found positive for FCoV RNA. Within the positive samples the presence of FCoV Type I was found in 79%. Type II was only detected in 3.5% in animals with Feline Infectious Peritonitis. The remaining 17.5% could not be differentiated. These viral sequences, comprising a region within gene S were further subjected to a heteroduplex mobility assay (HMA) detecting the presence of viral quasispecies in 17% of the samples. Phylogenetic analysis for FCoV Type I revealed high genetic diversity between the Portuguese sequences and other previously characterized strains, while Type II tree showed a higher genetic homogeneity. This study confirmed the presence of FCoV Types I and II circulating in Portugal and detected high genetic diversity between circulating strains suggesting that the virus persists within the host as mixed viral populations. 相似文献
37.
Moulay Chrif Smaili Lahcen El Ghadraoui Fatima Gaboun Rachid Benkirane Abdelali Blenzar 《Phytoparasitica》2014,42(3):421-436
Aphid control in Moroccan citrus orchards is based mainly on carbamate and neonicotinoid sprays, especially methomyl and imidacloprid. The extensive use of these insecticides may have side effects on natural enemies and environment quality and raises human health concerns. This research aimed to assess the control of aphids with insecticidal soap, kaolin and augmentative biological control using the indigenous predator Adalia decempunctata L. (Coleoptera: Coccinellidae). The insecticides were applied and the predators were released in April 2009 and 2010. Under field experimentation, the methomyl and imidacloprid foliar pulverization were very effective against aphids. In contrast, the insecticidal soap and kaolin application were less efficient while A. decempunctata adults were effective only in the first week after release. The side effects on beneficial insects were also assessed and discussed. The possibility of employing A. decempunctata in an integrated pest management package in citrus groves is discussed in relation to effectiveness and side effects on beneficial arthropods. 相似文献
38.
Host differentiation and variability of Orobanche crenata populations from legume species in Morocco as revealed by cross‐infestation and molecular analysis 下载免费PDF全文
39.
用10年生丛生竹的节片通过离体腋笋增殖和生根产生出府竹小苗。不同季节对无菌培养物的建立、腋芽发萌和初代培养的影响很大。3片丛生林中,无菌培养物的建立有差别,但腋芽发萌没有差别。用加有31.06uM BA和2.85um IAA的MS液体介质,最大的增值率为3.18;用加有20~25um IBA MS液体介质,离体生根率为66.7~77.8%。用不同的植物生长素,生根所用的天数也不同,而IBA液能在短期促进生根,仅仅为2-3周。成功炼苗后,在装有土壤、沙子和农家肥塑料袋里,离体繁殖的小苗成活率为90%,大约有2000株小苗用于野外栽植。 相似文献
40.
Danilo Henrique Nass Eduardo Luiz Tavares Gonçalves Mônica Yumi Tsuzuki 《Aquaculture International》2016,24(5):1255-1261
Amphiprion clarkii, a popular marine ornamental fish, despite having an already established reproduction technology, still presents divergences regarding the feeding protocol used for its larviculture in what concerns the ideal day of transition from rotifers to Artemia. This study aimed to determine the optimum time to start supplying Artemia to larvae. Survival, growth, weight gain and metamorphosis of treatments: (T2) start of Artemia supply at the 2nd day after hatching (DAH); (T4) start at the 4th DAH; and (T6) start at the 6th DAH were evaluated. Survival rates ranged from 60 to 66 %. Fish in T2 had a number of metamorphosed fish statistically higher than T6 and began to metamorphose 1 day sooner than other treatments. The positive results obtained for T2 can be related to the premature ability of this species to capture large live food, which can provide many benefits to the larvae. It is concluded that it is possible to offer Artemia nauplii to yellowtail clownfish at 2 DAH. 相似文献