全文获取类型
收费全文 | 178篇 |
免费 | 3篇 |
专业分类
林业 | 10篇 |
农学 | 15篇 |
基础科学 | 1篇 |
40篇 | |
综合类 | 1篇 |
农作物 | 60篇 |
水产渔业 | 15篇 |
畜牧兽医 | 24篇 |
园艺 | 3篇 |
植物保护 | 12篇 |
出版年
2023年 | 2篇 |
2022年 | 10篇 |
2021年 | 14篇 |
2020年 | 12篇 |
2019年 | 13篇 |
2018年 | 10篇 |
2017年 | 14篇 |
2016年 | 12篇 |
2015年 | 12篇 |
2014年 | 12篇 |
2013年 | 19篇 |
2012年 | 9篇 |
2011年 | 12篇 |
2010年 | 9篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 2篇 |
排序方式: 共有181条查询结果,搜索用时 15 毫秒
101.
The anticonvulsant activities of Crocus sativus stigma constituents, safranal and crocin, were evaluated in mice using pentylenetetrazole (PTZ)-induced convulsions in mice. Safranal (0.15 and 0.35 ml/kg, i.p.) reduced the seizure duration, delayed the onset of tonic convulsions and protected mice from death. Crocin (200 mg/kg, i.p.) did not show anticonvulsant activity. 相似文献
102.
In this study, viral pathogens associated with nine outbreaks of naturally occurring dairy calf pneumonia in Mashhad area
of Khorasan Razavi province from September 2008 to May 2009 were assessed. Five diseased calves from each farm were chosen
for examination. Acute and convalescent serum samples were taken from calves with signs of respiratory disease. Sera were
analyzed for antibodies to bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1 (BHV-1), bovine respiratory syncytial
virus (BRSV), parainfluenza virus type 3 (PI-3V), and bovine adenovirus-3 (BAV-3) by indirect ELISA kits. Among 42 serum samples
collected at sample 1, seroprevalence values for viruses BHV-1, BVDV, BRSV, PI-3V, and BAV-3 were 61.9% (26), 57.1% (24),
64.2% (27), 90% (38), and 61.9% (26), respectively. Seroconversion to BVDV, BRSV, PI-3V, and BAV-3 occurred in 11.9% (5),
16.6% (7), 26.1% (11), and 21.4% (9) of animals, and 52.3% (22) had generated antibodies against one or more viral infections
at sample 2. In addition, no significant relationship between seroprevalence of BHV-1, BVDV, BRSV, PI-3V, and BAV-3 and dairy
herd size was observed (P > 0.05). According to serological findings, BHV-1, BVDV, BRSV, PI-3V, and BAV-3 are common pathogens of the dairy calf pneumonia
in dairy herds in Mashhad area of Khorasan Razavi province, Iran. 相似文献
103.
Sana Eybpoosh Yeganeh Talebkhan Samaneh Saberi Maryam Esmaeili Akbar Oghalaie Fatemeh Ebrahimzadeh Toktam Karimi Afshin Abdirad Azin Nahvijou Mohammad Ali Mohagheghi Mahmoud Eshagh Hosseini Marjan Mohammadi 《Iranian Biomedical Journal》2015,19(3):133-142
Background:
Serologic screening of gastric cancer (GC) by serum pepsinogens (sPG) levels and Helicobacter pylori (Hp) sero-status, though highly informative, has provided heterogeneous results. Here, we have evaluated the modifying effects of demographic factors on the risk impact of Hp sero-status/sPG levels in gastric cancer, with particular emphasis on age.Methods:
A cross-sectional study was carried out on 1341 individuals (GC = 578, healthy = 763), who were stratified into two age groups: 35-59 years (middle-aged, n = 830) and ≥ 60 years (60 years-plus, n = 511). Demographic factors and serological states (Hp sero-staus and sPG levels) were recorded by subject interview and serum ELISAs, respectively. Covariate-specific odds ratios were calculated by multivariable logistic regression.Results:
Hp infection was consistently associated with increased sPGI and sPGII levels in the 60 year-plus, but not the middle-aged group. The joint examination of the variable states of the three serum biomarkers (Hp serology, sPGI, and sPGI/II ratio), in the 60 year-plus age group, demonstrated a stepwise escalation of risk from the single (sPGIlow; OR = 2.6), to double (sPGIlow/sPGI/IIlow; OR = 3.55, and Hppositive/sPGIlow; OR = 5.0) and ultimately triple (Hppositive/PGIlow/PGI/IIlow; OR = 10.48) positive states, in reference to the triple negatives. However, this pattern was not exhibited in the middle-aged subjects.Conclusion:
Age was clearly identified as a modifying factor on the risk projection of the combined states of Hp serology and sPG levels in gastric cancer screening, reflected by the augmented (~10.5 fold) risk of GC in the triple positive (Hppositive/sPGIlow/sPGI/IIlow) 60 year-plus subjects, which was not evident in the middle-aged group. Key Words: Biomarkers, Demography, Age Distribution 相似文献104.
Reza Moazzami Hasan Mirzahoseini Leila Nematollahi Farzaneh Barkhordari Mozhgan Raigani Fatemeh Hajari Taheri Fereidoun Mahboudi Fatemeh Davami 《Iranian Biomedical Journal》2021,25(4):275
Background:Bispecific antibodies represent an important class of mAbs, with great therapeutic potentials due to their ability to target simultaneously two distinct epitopes. The generation of functional bispecific antibodies with the highest possible yields is particularly critical for the production of these compounds on industrial scales. Anti- CD3 × CD19 bsAb is a bispecific T-cell engager (BiTE) currently used for treating ALL. Herein, we have tried to optimize the expression level of this antibody in mammalian hosts. Methods:WPRE sequence was incorporated at the 3’ end of the expression cassette. This modification resulted in a notable about two-fold increase in the expression of the bsAb in the Expi293 cell line. Results & Conclusion:Follow-up flow cytometry analysis demonstrated the binding properties of the produced antibody at acceptable levels, and in vitro bioactivity assays showed that this product is potent enough for targeting and destroying CD19-positive cells. Our findings show that WPRE enhances the expression of this type of bispecific mAbs in HEK-293 family cell lines. This approach can be used in biopharma industry for the mass production of anti-CD3 × CD19 bispecific antibody. Key Words: Acute lymphoblastic leukemia, Bispecific antibodies, Monoclonal antibody 相似文献
105.
Sharifa Sultana Dipti Christine Bergman Siti Dewi Indrasari Theja Herath Robert Hall Hueihong Lee Fatemeh Habibi Priscila Zaczuk Bassinello Eduardo Graterol Julie P Ferraz Melissa Fitzgerald 《Rice》2011,5(1):1-18
Elevated Na+ levels in agricultural lands are increasingly becoming a serious threat to the world agriculture. Plants suffer osmotic and ionic stress under high salinity due to the salts accumulated at the outside of roots and those accumulated at the inside of the plant cells, respectively. Mechanisms of salinity tolerance in plants have been extensively studied and in the recent years these studies focus on the function of key enzymes and plant morphological traits. Here, we provide an updated overview of salt tolerant mechanisms in glycophytes with a particular interest in rice (Oryza sativa) plants. Protective mechanisms that prevent water loss due to the increased osmotic pressure, the development of Na+ toxicity on essential cellular metabolisms, and the movement of ions via the apoplastic pathway (i.e. apoplastic barriers) are described here in detail. 相似文献
106.
107.
Effect of nickel (Ni) in the nutrient solution on yield, N metabolism, and nitrate content of leafy vegetables is poorly understood. The aim of this nutrient solution culture experiment was to investigate the effects of Ni supplementation on the nitrogen (N) metabolism and growth of lettuce (Lactuca sativa L. cv. Baker) with either urea or nitrate as the N source. Nickel supplement at 0.04 μM reduced urea toxicity to the urea-fed plants. Addition of Ni to the nutrient solution significantly increased the leaves and root growth of the urea-fed lettuce plants while it increased the growth of lettuce plants fed with nitrate only at N level of 20 mM. At N level of 20 mM, the leaves fresh weight of the urea-fed plants promoted by Ni supplement was comparable with the nitrate-fed plants untreated with Ni. Nickel supplementation increased the leaf total N concentrations in the urea-fed plants, although the nitrate-fed plants accumulated greater N in their leaves compared with urea treated plants at without Ni treatment. Nickel addition decreased the concentrations of leaf urea-N in the urea-fed plants and NO3-N in the nitrate-fed plants. Nickel addition enhanced urease activity in the leaves of urea-fed plants. The results indicated Ni supplementation enhances the growth of the urea-fed lettuce plants while it has role in decreasing leaf nitrate concentration and thus, improving the health quality of the nitrate-fed plants. 相似文献
108.
109.
The electrospinnability of aloe vera gel and the release mechanism as well as the kinetic of its release from poly vinyl alcohol (PVA) nanofibrous matrix is reported. Addition of PVA by an amount of only 1 % (w/w) to aloe vera solution made its electrospinning possible leading, to the fabrication of aloe vera nanofiber (99 %) with an average diameter of around 80 nm. Electrospinning of aloe vera-PVA solutions (25-75, 50-50, 75-25) led to the fabrication of nanofibers with average diameter of around 55, 105 and 110 nm, respectively. FTIR analysis showed no reaction between aloe vera and PVA. X-ray diffraction patterns showed no considerable effect from aloe vera on the amorphous structure of PVA. The release mechanism of aloe vera from PVA matrix in phosphate buffer solution was of Ficki type and the kinetic of the release followed Higuchi model. Aloe vera or aloe vera-PVA electrospun nanofibers may be used as an aloe vera release system in wound care. In a phosphate buffer solution, at least 60 percent of aloe vera is released in the first hour and about 90 % of aloe vera is released in 2-4 hours depending on the diameter of the nanofibers. 相似文献
110.
Fatemeh Emami Shahla Shekarriz Zahra Shariatinia Zahra Moridi Mahdieh 《Fibers and Polymers》2018,19(5):1014-1023
Nylon 6 fabric with self-cleaning properties was prepared by corona discharge pre-treatment and coating with TiO2 nanoparticles (NPs) using pad-dry-cure technique. The self-cleaning property was studied by discoloration of methylene blue (MB), ketchup, tea and coffee stains from the corona+TiO2 treated nylon-6 fabric. Color difference (ΔΕ*), reflectance (R) and K/S of MB stain were investigated by diffuse reflectance spectrophotometry. The MB stain was almost completely removed from the corona+TiO2 treated nylon surface after 24 h under UV light/daylight irradiation. Both of these phenomena (corona and TiO2) led to an increase in the discoloration of stains under UV and daylight irradiations. The EDS analysis showed an increase in the concentration of deposited TiO2 NPs coating after corona treatment. The FE-SEM images revealed that the surface of nylon 6 was coarser after the corona treatment. Also, the FE-SEM micrographs exhibited that a uniform layer of TiO2 NPs was formed on the corona treated nylon fabric. The corona+TiO2 treated nylon illustrated antibacterial activity against E. coli and B. subtillis microorganisms. The EDS and FE-SEM analysis confirmed that after 5 washing cycles, the amount of TiO2 NPs was higher on the surface of corona+TiO2 treated nylon than that of the fabric only treated with TiO2 without corona pretreatment. This result justifies that the corona+TiO2 treated nylon fabric with appropriate self-cleaning property can be applied cost-effectively in the textile industry. 相似文献