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991.
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993.
AIM:To investigate the key molecular mechanism of inflammatory response in alveolar epithelial cells induced by nontypeable haemophilus influenzae (NTHi). METHODS: A549 cells were co-cultured with NTHi (multiplicity of infection, MOI: 10) and harvested 15 min and 30 min after stimulation. The phosphorylation of p38 mitogen activated protein kinase (p38 MAPK) in A549 cells was detected by Western blotting. The intracellular expression of nuclear factor-κB (NF-κB) p65 was examined by flow cytometry 4 h after stimulation. A549 cells were preincubated with p38 inhibitor (SB203580) or NF-κB inhibitor (PDTC) for 1 h and then stimulated with NTHi for 24 h. The level of interleukin 8 (IL-8) in the supernatants was determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: The phosphorylation of p38 MAPK was rapidly induced by NTHi stimulation. The expression of NF-κB p65 in A549 cells after NTHi stimulation was significantly up-regulated compared with control group (P<0.05). The level of IL-8 in the supernatants was increased 24 h after bacterial stimulation compared with control group (P<0.05). Blockage of p38 MAPK or NF-κB remarkably decreased IL-8 secretion in A549 cells (P<0.05). CONCLUSION:NTHi induces inflammatory response in alveolar epithelial cells in a p38 MAPK and NF-κB dependent manner. 相似文献
994.
AIM: To study the changes of zinc transporter gene expression in A-549 cell line exposed to ZnCl2 and N,N,N’,N’-tetrakis 2-pyridylmethyl ethylenediamine (TPEN).METHODS: Human lung cancer cell line A-549 was exposed to different concentrations of ZnCl2 (0, 50, 100, 150, 200 μmol/L) and TPEN (0, 5, 10, 15, 20 μmol/L), respectively. Twelve hours later, the cell viability was measured by MTT (methyl thiazolyl tetrazolium) and levels of zinc transporter mRNA was detected by RT-PCR. Zinquin was used to estimate the intracellular zinc concentrations.RESULTS: A-549 cell viability rate was significantly decreased when exposed to ZnCl2 at concentrations of 150 and 200 μmol/L, and to TPEN. The intracellular zinc concentration was significantly increased when exposed to ZnCl2 and decreased when exposed to TPEN. Zinc transporter (ZnT-1) mRNA level was increased along with the increase in the concentration of ZnCl2 but decreased when exposed to TPEN. The expressions of ZIP-1 and ZIP-10 (Zrt-and Irt-like protein) were increased along with the increase in the concentration of TPEN but decreased when exposed to ZnCl2.CONCLUSION: ZnT-1 expression is induced by zinc supplement. ZIP-1 and ZIP-10 expressions are induced by zinc deficiency and repressed by zinc supplement. 相似文献
995.
996.
Effects of fruit bagging on coloring and related physiology,and qualities of red Chinese sand pears during fruit maturation 总被引:1,自引:0,他引:1
Chunhui Huang Bo Yu Yuanwen Teng Jun Su Qun Shu Zaiquan Cheng Liqiong Zeng 《Scientia Horticulturae》2009
Red Chinese sand pears (Pyrus pyrifolia Nakai) are particular to China. In order to determine the effects of fruit bagging treatments (including bag types, bag removal patterns and dates) on fruit qualities and to understand the mechanism of coloring of red Chinese sand pears, two experiments were carried out. In the first experiment, fruit of ‘Meirensu’ were firstly covered by light-impermeable paper bags with different levels of light permeable liners during their early development stage, then, the whole bag were/not removed or only the outer layer of bags were removed 3, 2 or 1 weeks before harvest. Thus, the fruit were/not totally re-exposed or were under different levels of sunlight transmission (80.31% or 34.71%). Non-bagged fruit were used as the control. Bagging treatments significantly affected the concentration of anthocyanin and the visual qualities of pear fruit. Compared to control, fruit re-exposed totally for 2 or 3 weeks accumulated the largest amount of anthocyanin and fruit receiving 80.31% and 34.71% of sunlight for 1–3 weeks could synthesize a little anthocyanin, indicating that high light intensity is imperative for coloring in red Chinese sand pears. Bagging treatments did not affect contents of total soluble sugars, but decreased organic acids contents in fruit. In the second experiment, fruit of ‘Meirensu’ and ‘Yunhongli No. 1’ were covered with only one type of light-impermeable bag during the early development stage and totally re-exposed after the bag removal 15 days before harvest. Fruit were then collected at different intervals to trace the time-course of coloring, and related physiology and inner qualities. With increasing time after the bag removal, the concentration of chlorophyll, carotenoid, flavonoid and total phenols changed little, but the concentration of anthocyanin accumulated extremely fast within 10 days after the bag removal in both cultivars and thereafter kept constant. ‘Yunhongli No. 1’ had higher anthocyanin contents and lower hue angle than ‘Meirensu’, indicating a higher potential of anthocyanin synthesis. After the bag removal, the sucrose contents and PAL activities increased gradually and correlation analysis revealed that they were highly correlated with anthocyanin accumulation in two cultivars. This study suggests that anthocyanin biosynthesis in red Chinese sand pears is a highly light dependent process and modified by genotypes. Based on the current results, in order to obtain red Chinese sand pear fruit with attractive appearance and good inner qualities, fruit must be covered with light-impermeable bags at the early stage of fruit development and the bag should be removed totally at least 10 days before harvest. 相似文献
997.
998.
XIAO Xiao-ping LI Yue-qin XU Bin LI Hong-jian ZHANG Xin ZHOU Tian-hong ZOU Yi 《园艺学报》2009,25(7):1254-1261
AIM: To study the anti-proliferation effect of overexpressed SSTR2 in experimental cancer with different profiles of endogenous SSTRs expressions and the possible signaling pathways involved. METHODS: In the first experiment, the growth of the tumor xenografts of the inoculated capan-2 cells and A549 cells overexpressing SSTR2 or LacZ was investigated in nude mice. In the second experiment, the adenoviral vector expressing SSTR2 were introduced into experimental capan-2 xenografts by intratumoral injection. The growth inhibition of these experiment tumors was observed and the potential influences on different signaling pathways were analyzed by immunoassays. RESULTS: Overexpression of SSTR2 inhibited the growth of tumors with different profiles of endogenous SSTRs, including experimental capan-2 xenografts that had endogenous SSTR2 expression. Overexpression significantly affected a number of components in apoptotic pathway, MAPK pathway and angiogenesis. CONCLUSION: SSTR2 is a promising candidate for gene therapy in a wide spectrum of cancers. 相似文献
999.
AIM: To explore whether A3 adenosine receptor plays a role in the modulation of vascular reactivity after hemorrhagic shock in rat, and to find out the prospective drug target to restore the decreased vascular reactivity following hemorrhagic shock. METHODS: The hemorrhagic shock (40 mmHg) model was established in rat, and the reactivity of superior mesenteric artery (SMA) to norepinephrine (NE) was observed. A3AR expression at protein level and mRNA level were measured by Western blotting and RT-PCR respectively. RESULTS: The vascular reactivity of SMA to NE after hemorrhagic shock (40 mmHg) was decreased significantly in a biphasic response manner. The expression of A3AR mRNA in SMA after hemorrhagic shock decreased without significant difference. The expression of A3AR protein has a slight increase without statistical difference after 30 min of hemorrhagic shock and then has a significant decrease (especially at 2 h and 4 h after hemorrhagic shock). The usage of IB-MECA, a selective A3AR agonist, significantly increased the responsiveness of SMA to NE in hemorrhagic shock in rat. MRS1523, the selective A3AR antagonist, significantly abolished the restoration of the vascular reactivity to NE by IB-MECA in hemorrhagic shock in rat. CONCLUSION: A3AR plays a role in the modulation of vascular responsiveness to NE in hemorrhagic shock in rat, and the selective agonist of A3AR could restore the reactivity of SMA to NE in hemorrhagic shock in rat. 相似文献
1000.
ZHANG Ying CHENG Hua LUO Zhao-fan XU Ming-tong ZHANG Shao-ling LI Feng YAN Li LI Yan 《园艺学报》2009,25(7):1376-1380
AIM: To evaluate the role of G protein-coupled receptor 40 (GPR40) mediates the effects of free fatty acids (FFAs) on lipoapoptosis in mouse β-cell line NIT-1 and the mechanisms involved in this process.METHODS: NIT-1 cells were supplemented with palmitate (500 μmol/L) or oleate (500 μmol/L) for 48 h, then apoptosis of the cells was determined by the methods of Hoechst 33342, TUNEL and flow cytometry (Annexin V/PI). The small interfering RNA technique was used to inhibit the expression of GPR40 in NIT-1 cell. The mock, control siRNA and GPR40 siRNA transfected cells were either supplemented with palmitate (500 μmol/L) or co-incubated with palmitate and oleate (500 μmol/L for each) for 48 h. The percentages of apoptotic cells were quantified. The expression of p-c-Jun, Bcl-2 and Bax were detected by Western blotting.RESULTS: Palmitate induced β cell lipoapoptosis, whereas oleate inhibited NIT-1 cells from palmitate-induced lipoapoptosis. No significant difference of the percentages of apoptotic cells was indicated among the mock, control siRNA and GPR40 siRNA transfected cells treated with palmitate (P>0.05). However, after co-incubated with palmitate and oleate (500 μmol/L for each) for 48 h, the percentage of apoptotic cells in GPR40 siRNA transfected cells was greater than that in mock (P<0.05), while the expression of p-c-Jun was decreased. The expressions of Bcl-2 and Bax were not affected.CONCLUSION: Palmitate induced β cell lipoapoptosis might not be mediated through GPR40, whereas oleate inhibits NIT-1 cells from palmitate-induced lipoapoptosis, which is mediated at least in part through GPR40, the change of c-Jun expression may play an role in this process, suggesting that GPR40 might be implicated in the control of β cell mass plasticity and GPR40 probably provides a link between obesity and type 2 diabetes. 相似文献