全文获取类型
收费全文 | 250篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
林业 | 30篇 |
农学 | 16篇 |
基础科学 | 1篇 |
50篇 | |
综合类 | 18篇 |
农作物 | 20篇 |
水产渔业 | 46篇 |
畜牧兽医 | 50篇 |
园艺 | 8篇 |
植物保护 | 16篇 |
出版年
2024年 | 6篇 |
2023年 | 8篇 |
2022年 | 10篇 |
2021年 | 12篇 |
2020年 | 8篇 |
2019年 | 14篇 |
2018年 | 18篇 |
2017年 | 14篇 |
2016年 | 13篇 |
2015年 | 12篇 |
2014年 | 12篇 |
2013年 | 19篇 |
2012年 | 17篇 |
2011年 | 15篇 |
2010年 | 12篇 |
2009年 | 8篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 9篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2000年 | 3篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1945年 | 1篇 |
排序方式: 共有255条查询结果,搜索用时 582 毫秒
101.
Syed Sultan Beevi Lakshmi Narasu Mangamoori Murugan Subathra Jyotheeswara Reddy Edula 《Plant foods for human nutrition (Dordrecht, Netherlands)》2010,65(3):200-209
Raphanus sativus, a common cruciferous vegetable has been attributed to possess a number of pharmacological and therapeutic properties. It
has been used in indigenous system of medicine for the treatment of various human ailments in India. This present study evaluated
the chemopreventive efficacy of different parts of R. sativus such as root, stem and leaves, extracted with solvents of varying polarity and investigated the molecular mechanism leading
to growth arrest and apoptotic cell death in human cancer cell lines. Of the different parts, significant growth inhibitory
effect was observed with hexane extract of R. sativus root. Analysis of hexane extract by GC-MS revealed the presence of several isothiocyanates (ITCs) such as 4-(methylthio)-3-butenyl
isothiocyanate (MTBITC), 4-(methylthio)-3-butyl isothiocyanate (erucin), 4-methylpentyl isothiocyanate, 4-pentenyl isothiocyanate
and sulforaphene. R. sativus root extract induced cell death both in p53 proficient and p53 deficient cell lines through induction of apoptotic signaling
pathway regardless of the p53 status of cells. The molecular mechanisms underlying R. sativus-induced apoptosis may involve interactions among Bcl2 family genes, as evidenced by up-regulation of pro-apoptotic genes and down-regulation of anti-apoptotic genes along with
activation of Caspase-3. Our findings present the first evidence that hexane extract of R. sativus root exerts potential chemopreventive efficacy and induces apoptosis in cancer cell lines through modulation of genes involved
in apoptotic signaling pathway. 相似文献
102.
Vikash Babu Syed Khalid Pasha Govind Gupta C. B. Majumdar Bijan Choudhury 《Fibers and Polymers》2014,15(1):24-29
Polyacrylonitrile (PAN) is a widely used polymer in the textile industry. PAN contains cyano groups on the surface due to which it possess low hydrophilicity and limits its application. Thus, there is a need to modify the functional groups on the surface of PAN for its industrial demand to improve moisture uptake, dyeability with ionic dyes, without affecting mechanical properties. A number of strategies such as chemical treatment, plasma treatment, enzymatic treatment etc. have been applied for the surface modification of polymer but enzymatic treatment are advantageous over plasma treatment and chemical treatment. In enzymatic treatment, reaction is limited to polymer surface only, and provides milder condition with less damage to polymer. In present study, it was found that enzyme system of Amycolatopsis sp.IITR215 was effective enzyme system for modification of surface nitrile groups of polyacrylonitrile. PAN powder was treated with the cell free extract of Amycolatopsis sp.IITR215 and it was found that the nitrile metabolizing enzymes of this strain were efficiently able to transform -CN to -COOH groups present on the surfaces of PAN powder. The formation of carboxyl group was quantified by ammonia released and dye binding assay. Further, confirmation of carboxyl group on polymer was done by FTIR and XPS. This study indicates that, specific adsorption of enzyme probably plays an important role in the enzymatic surface modification of polymer. 相似文献
103.
Mahmoud A. A. Ibrahim Alaa H. M. Abdelrahman Mohamed A. M. Atia Tarik A. Mohamed Mahmoud F. Moustafa Abdulrahim R. Hakami Shaden A. M. Khalifa Fahad A. Alhumaydhi Faris Alrumaihi Syed Hani Abidi Khaled S. Allemailem Thomas Efferth Mahmoud E. Soliman Paul W. Par Hesham R. El-Seedi Mohamed-Elamir F. Hegazy 《Marine drugs》2021,19(7)
104.
Chickpea (Cicer arietinum L.) roots exude carboxylates. While chickpea commonly grows where the topsoil dries out during crop growth, the importance of carboxylate exudation by the roots and mobilization of soil P from below the dry topsoil has not been examined. The study investigates the response of carboxylate exudation and soil P mobilization by this crop to subsoil P fertilizer rate. In constructed soil columns in the glasshouse, the P levels (high, low, and nil P) were varied in the well‐watered subsoil (10–30 cm), while a low level of P in the dry topsoil (0–10 cm) was maintained. At flowering, rhizosphere carboxylates and rhizosphere soil from topsoil and subsoil roots were collected separately and analyzed. The concentration of total carboxylates per unit rhizosphere mass in the subsoil was nearly double that of the topsoil. Plants depleted sparingly soluble inorganic P (Pi), NaOH‐Pi, and HCl‐Pi, along with the labile Pi (water soluble and NaHCO3‐Pi). The P depletion by plants was greater from the subsoil than the topsoil. The study concluded that depletion of sparingly soluble P from the chickpea rhizosphere in the subsoil was linked with the greater levels of carboxylates in the rhizosphere. These findings indicate that chickpea, with its deep rooting pattern, can increase its access to subsoil P when the topsoil dries out during crop growth by subsoil rhizosphere modification. 相似文献
105.
Shahzad Ali Qurban Ali Falk Melzer Iahtasham Khan Shamim Akhter Heinrich Neubauer Syed M. Jamal 《Tropical animal health and production》2014,46(1):73-78
Brucellosis is endemic in bovines in Pakistan. The Brucella species and biovars involved, however, are unknown. The objectives of the present study were to isolate and characterize brucellae from seropositive milk samples, aborted fetuses, and vaginal swabs of cattle and buffaloes which had recently aborted. The seropositive milk samples, aborted fetuses, and vaginal swabs of cattle and buffaloes were collected from the Potohar Plateau, Pakistan. Isolation of brucellae was done on modified Farrell’s serum dextrose agar. Isolates were characterized by conventional biotyping methods, while molecular typing was done by genus (B4/B5) and species-specific (Brucella abortus, Brucella melitensis, Brucella ovis, and Brucella suis) polymerase chain reaction (PCR). A total of 30 isolates were recovered from milk (n?=?5), aborted fetuses (n?=?13), and vaginal swabs (n?=?12). Most isolates were from cattle (56.7 %). All of them were identified as B. abortus biovar 1 based on conventional biotyping methods and genus and species-specific PCR. This preliminary study provides the first report on the prevalence of B. abortus biovar 1 in cattle and buffaloes in Pakistan. 相似文献
106.
Adamu S. G. Kabir J. Umoh J. U. Raji M. A. 《Tropical animal health and production》2018,50(7):1583-1589
Tropical Animal Health and Production - A cross sectional study was conducted to determine the seroprevalence and risk factors of brucellosis and Q fever in cattle in Maigana and Birnin Gwari... 相似文献
107.
The growth factor progranulin binds to TNF receptors and is therapeutic against inflammatory arthritis in mice 总被引:1,自引:0,他引:1
Tang W Lu Y Tian QY Zhang Y Guo FJ Liu GY Syed NM Lai Y Lin EA Kong L Su J Yin F Ding AH Zanin-Zhorov A Dustin ML Tao J Craft J Yin Z Feng JQ Abramson SB Yu XP Liu CJ 《Science (New York, N.Y.)》2011,332(6028):478-484
The growth factor progranulin (PGRN) has been implicated in embryonic development, tissue repair, tumorigenesis, and inflammation, but its receptors remain unidentified. We report that PGRN bound directly to tumor necrosis factor receptors (TNFRs) and disturbed the TNFα-TNFR interaction. PGRN-deficient mice were susceptible to collagen-induced arthritis, and administration of PGRN reversed inflammatory arthritis. Atsttrin, an engineered protein composed of three PGRN fragments, exhibited selective TNFR binding. PGRN and Atsttrin prevented inflammation in multiple arthritis mouse models and inhibited TNFα-activated intracellular signaling. Collectively, these findings demonstrate that PGRN is a ligand of TNFR, an antagonist of TNFα signaling, and plays a critical role in the pathogenesis of inflammatory arthritis in mice. They also suggest new potential therapeutic interventions for various TNFα-mediated pathologies and conditions, including rheumatoid arthritis. 相似文献
108.
Jeremy B. Foote Farruk M. Lutful Kabir Emily C. Graff Russell C. Cattley Patricia DeInnocentes Bruce F. Smith R. Curtis Bird 《Veterinary immunology and immunopathology》2014,157(3-4):131-141
To study the canine immune system we generated a mouse model engrafted with canine lymphocytes using NOD SCID IL2R common gamma chain ?/? (NSG) mice as recipients (Ca-PBL-SCID). Engraftment of canine peripheral blood lymphocytes (PBLs) was determined post-injection with 107 peripheral blood mononuclear cells (PBMCs) into irradiated NSG mice using flow cytometry and fluorescently labeled antibodies specific to canine helper T cells (CD45+ CD4+), cytotoxic lymphocytes (CD45+ CD8+), regulatory T cells (CD45+ CD4+ Foxp3+), and B cells (CD45+ Ig+ CD21lo). Canine CD45+ lymphocytes were detectable as early as day 1 in the peritoneal cavity, and beginning at 9 days in the blood, bone marrow, and spleen. CD4+ T cells, of which Foxp-3+ CD25hi cells constituted a minor percentage, were the predominant lymphocyte population at 9 days post engraftment contrasting with increasing proportions of CD8+ CTL's and Ig+ B cells beginning at 16 days. Canine immunoglobulin was initially detected in the serum of Ca-PBL-SCID mice at 9 days post-engraftment and peaked in concentration at day 36. From day 28 to 52 post-engraftment 30% of the Ca-PBL-SCID mice became markedly anemic and thrombocytopenic, yet gross and histopathologic examination of bone marrow, kidneys, spleen, liver, and intestine revealed no obvious lesions. Blood smear evaluation revealed agglutination of mature red blood cells, reticulocytes and a regenerative anemia. These findings demonstrate that NSG mice are capable of engraftment of canine PBLs yet develop graft versus host disease similar to Hu-PBL-SCID mice. 相似文献
109.
Baktiar O. Karim Syed Z. Ali Jennifer A. Landolfi Jill F. Mann Guosheng Liu Archie Christian John F. Dicello Dorothy L. Rosenthal David L. Huso 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2008,37(2):229-236
Background: Fine needle aspiration (FNA) offers a rapid and minimally invasive means to distinguish malignant from benign neoplasms. However, few studies have been published regarding the cytopathology of mammary tumors in rats despite widespread use of the rat model for breast cancer formation and inhibition.
Objective: The purpose of this study was to determine the diagnostic accuracy of FNA cytology and to develop distinguishing cytologic criteria for the diagnosis of radiation-induced benign and malignant mammary tumors in rats.
Methods: In a study of radiation-induced mammary carcinogenesis, 100 Sprague–Dawley rats with cutaneous masses were randomly chosen for FNA. The aspirates were smeared, fixed, and stained with a modified Papanicolaou procedure for diagnostic evaluation. Cytologic and histologic diagnoses (benign vs malignant) were compared, and diagnostic accuracy was calculated using the histologic diagnosis as the criterion standard. FNA smears were scored semiquantitatively on a scale of 1–4 for cellularity, atypia, nuclear size, chromatin pattern, nuclear membrane thickness, nucleoli, and mitoses. The background was evaluated for necrosis, hemorrhage, inflammation, and mucosecretory material. Cytomorphologic features were compared statistically between benign and malignant tumors, based on the histologic diagnosis.
Results: The sensitivity of FNA was 92.3% and specificity was 89.4% for the detection of malignancy. However, 14% of specimens, all fibroadenomas by histology, had insufficient cells for cytologic evaluation, for an overall accuracy rate of 78.0%. Malignant tumors had significantly higher scores for all cytomorphologic features, and were significantly more likely to contain cell clusters and necrotic debris.
Conclusions: FNA is an accurate method for differentiating benign and malignant rat mammary tumors. 相似文献
Objective: The purpose of this study was to determine the diagnostic accuracy of FNA cytology and to develop distinguishing cytologic criteria for the diagnosis of radiation-induced benign and malignant mammary tumors in rats.
Methods: In a study of radiation-induced mammary carcinogenesis, 100 Sprague–Dawley rats with cutaneous masses were randomly chosen for FNA. The aspirates were smeared, fixed, and stained with a modified Papanicolaou procedure for diagnostic evaluation. Cytologic and histologic diagnoses (benign vs malignant) were compared, and diagnostic accuracy was calculated using the histologic diagnosis as the criterion standard. FNA smears were scored semiquantitatively on a scale of 1–4 for cellularity, atypia, nuclear size, chromatin pattern, nuclear membrane thickness, nucleoli, and mitoses. The background was evaluated for necrosis, hemorrhage, inflammation, and mucosecretory material. Cytomorphologic features were compared statistically between benign and malignant tumors, based on the histologic diagnosis.
Results: The sensitivity of FNA was 92.3% and specificity was 89.4% for the detection of malignancy. However, 14% of specimens, all fibroadenomas by histology, had insufficient cells for cytologic evaluation, for an overall accuracy rate of 78.0%. Malignant tumors had significantly higher scores for all cytomorphologic features, and were significantly more likely to contain cell clusters and necrotic debris.
Conclusions: FNA is an accurate method for differentiating benign and malignant rat mammary tumors. 相似文献
110.
Ilyas Ali Syed Muhammad Suhail Muhammad Shafiq 《Reproduction in domestic animals》2019,54(7):1026-1033
Inheritance of economic traits and their genetic correlation was studied in different breeds and their various grades (crossbred’s cattle) under the subtropical condition. Data on principal parameters comprising 10 years, that is 2004–2014, were utilized for the present study. Different grades of dairy cows comprising Holstein Friesian (HF), Sahiwal x Friesian (SxHF), Jersey (J), Jersey x Achai (JxAC) and Achai (AC) were included in the study. Heritability estimates and genetic correlations of some important productive and reproductive traits were worked out. Heritability estimates of certain economic traits were found to be: birthweight, 0.32 ± 0.181; age at maturity, 0.11 ± 0.136; age at first calving, 0.19 ± 0.162; days open, 0.09 ± 0.121; calving interval, 0.14 ± 0.211; dry period, 0.11 ± 0.124; lactation length, 0.04 ± 0.212 and lactation yield, 0.46 ± 0.206. Genetic correlation showed that body weight was significantly and positively correlated with lactation length (0.30) and lactation yield (0.81), while negatively correlated with age at maturity, age at first calving, days open, calving interval and dry period (?0.09, ?0.07, ?0.16, ?0.34 and ?0.002, respectively). Calving interval was positively and significantly correlated with the dry period (0.56), lactation length (0.72) and lactation yield (0.37). Moderate to higher heritability estimates with adequate genetic variance was found for body weight and lactation yield. The moderate to higher heritability estimates of birthweight in the present study revealed that this important trait might be considered in selection criteria. 相似文献