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21.
Ito S Ihara T Tamura H Tanaka S Ikeda T Kajihara H Dissanayake C Abdel-Motaal FF El-Sayed MA 《FEBS letters》2007,581(17):3217-3222
The tomato saponin alpha-tomatine has been proposed to kill sensitive cells by binding to cell membranes followed by leakage of cell components. However, details of the modes of action of the compound on fungal cells are poorly understood. In the present study, mechanisms involved in alpha-tomatine-induced cell death of fungi were examined using a filamentous pathogenic fungus Fusarium oxysporum. alpha-Tomatine-induced cell death of F. oxysporum (TICDF) occurred only under aerobic conditions and was blocked by the mitochondrial F(0)F(1)-ATPase inhibitor oligomycin, the caspase inhibitor D-VAD-fmk, and protein synthesis inhibitor cycloheximide. Fungal cells exposed to alpha-tomatine showed TUNEL-positive nuclei, depolarization of transmembrane potential of mitochondria, and reactive oxygen species (ROS) accumulation. These results suggest that TICDF occurs through a programmed cell death process in which mitochondria play a pivotal role. Pharmacological studies using inhibitors suggest that alpha-tomatine activates phosphotyrosine kinase and monomeric G-protein signaling pathways leading to Ca(2+) elevation and ROS burst in F. oxysporum cells. 相似文献
22.
Ben Fredj R Gross E Chouchen L B'Chir F Ben Ahmed S Neubauer S Kiechle M Saguem S 《Comptes rendus biologies》2007,330(10):764-769
Dihydropyrimidine dehydrogenase enzyme (DPD) deficiency is a pharmacogenetic syndrome leading to severe side-effects in patients receiving therapies containing the anticancer drug 5-fluorouracil (5-FU). The aim of this population study is to evaluate gene variations in the coding region of the dihydropyrimidine dehydrogenase gene (DPYD) in the Tunisian population. One hundred and six unrelated healthy Tunisian volunteers were genotyped by denaturing HPLC (DHPLC). Twelve variants in the coding region of the DPYD were detected. Allele frequencies of DPYD*5 (A1627G), DPYD*6 (G2194A), DPYD*9A (T85C), A496G, and G1218A were 12.7%, 7.1%, 13.7%, 5.7%, and 0.5%, respectively. The DPYD alleles DPYD*2A (IVS 14+1g>1), DPYD*3 (1897 del C) and DPYD*4 (G1601A) associated with DPD deficiency were absent from the examined subjects. We describe for the first time a new intronic polymorphism IVS 6-29 g>t, found in an allelic frequency of 4.7% in the Tunisian population. Comparing our data with that obtained in Caucasian, Egyptian, Japanese and African-American populations, we found that the Tunisian population resembles Egyptian and Caucasian populations with regard to their allelic frequencies of DPYD polymorphisms. This study describes for the first time the spectrum of DPYD sequence variations in the Tunisian population. 相似文献
23.
Abdenaceur Reghmit Farida Benzina-tihar Mourad Djeziri Rima Hadjouti Zahia Oukali Fatma Sahir-Halouane 《International microbiology》2022,25(4):817-829
International Microbiology - Trichoderma species have been widely recognized as biofertilizer fungi for their ability to produce phytohormones and enhance plant growth. In our current study,... 相似文献
24.
Jiang G Akar F Cobbs SL Lomashvilli K Lakkis R Gordon FJ Sutliff RL O'Neill WC 《American journal of physiology. Heart and circulatory physiology》2004,286(4):H1552-H1557
The Na-K-2Cl cotransporter (NKCC1) is one of several transporters that have been linked to hypertension, and its inhibition reduces vascular smooth muscle tone and blood pressure. NKCC1 in the rat aorta is stimulated by vasoconstrictors and inhibited by nitrovasodilators, and this is linked to the contractile state of the smooth muscle. To determine whether blood pressure also regulates NKCC1, we examined the acute effect of hypertension on NKCC1 in rats after aortic coarctation. In the hypertensive aorta (28-mmHg rise in mean blood pressure), an increase in NKCC1 activity (measured as bumetanide-sensitive (86)Rb efflux) was apparent by 16 h and reached a plateau of 62% greater than control at 48 h. In contrast, there was a slight decrease in NKCC1 activity in the hypotensive aorta (21% decrease in mean blood pressure). Measurement of NKCC1 mRNA by real-time PCR revealed a fivefold increase in the hypertensive aorta compared with the hypotensive aorta or sham aorta. The inhibition by bumetanide of isometric force response to phenylephrine was significantly greater in the hypertensive aorta than in the control aorta or hypotensive aorta. We conclude that NKCC1 in rat aortic smooth muscle is regulated by blood pressure, most likely through changes in transporter abundance. This upregulation of NKCC1 is associated with a greater contribution to force generation in the hypertensive aorta. This is the first demonstration that NKCC1 in vascular smooth muscle is regulated by blood pressure and indicates that this transporter is important in the acute response of vascular smooth muscle to hypertension. 相似文献
25.
The plasma and erythrocyte levels of zinc, copper, and magnesium and the activities of red-cell copper-zinc superoxide dismutase
(Cu/Zn-SOD) and catalase (CAT) were determined in patients with benign and malignant tumors of the larynx. Blood samples from
patients and healthy controls were drawn using heparinized tubes. The erythrocyte Cu/Zn-SOD and CAT activities were determined
spectrophotometrically and the zinc, copper, and magnesium concentrations were determined in erythrocyte and plasma by atomic
absorption spectrometry. Variance analysis was employed in the statistical evaluation of the findings.
There was a significant increase in red-cell Cu/Zn-SOD activity in the subjects with malignant and benign tumors compared
to controls (p<0.001). The CAT activity increased only in the benign tumor group (p<0.01). The plasma zinc concentrations were significantly lower in the malignant tumor group (p<0.05) and significantly higher in the benign tumor group (p<0.01). The erythrocyte copper concentrations were significantly lower in both benign and malignant tumor groups (p<0.001). The plasma copper and magnesium and the erythrocyte magnesium concentrations did not show significant differences
relative to controls (p>0.05).
The increases in the activities of SOD and CAT activities and the changes in trace elements concentrations can indicate the
presence of increased reactive oxygen species that might play a part in the pathogenesis larynx tumors.
Presented at the IX Asian-Pacific Congress of Clinical Biochemistry, March 9–14, 2002, New Delhi, India. 相似文献
26.
Some new 2-alkoxy-3-cyano-4,6-diarylpyridines 3,4 were synthesized by condensation of different alpha,beta-unsaturated ketones 1 with malononitrile 2, followed by cyclization in sodium alkoxide/alcohol system. Lewis acid-catalyzed reaction of 4 with hydrazine afforded the corresponding 1H-pyrazolo[3,4-b]pyridines 5. The potency of the results as antimicrobial agents has been evaluated. The structure of the newly prepared compounds was assessed by microanalysis, IR and NMR spectra. Molecular mechanics (MM2) and semiemperical (AM1) molecular orbital calculations have been performed for the most biologically active compounds 5b and c to get insight into their molecular structures and to learn more about their stable molecular conformations. 相似文献
27.
Uyanik F 《Biological trace element research》2001,84(1-3):93-101
The effects of dietary inorganic chromium on some biochemical parameters were determined in lambs fed either a control diet
or a 200-ppb or 400-ppb chromium-supplemented diet. The live weight of the animals were measured and jugular blood samples
were collected prior to supplementation (d 0) and on d 20, 40, and 55. On d 55, three animals from each group were slaughtered
to measure subcutaneous fat. Sera were analyzed for glucose, triglyceride, total cholesterol, high-density lipoprotein (HDL)
and low-density lipoprotein (LDL) cholesterol, total protein, albumin, ALT, AST, and GGT levels. Chromium supplementation
had no significant effect on live weight, but subcutaneous fat was reduced significantly in both chromium groups. There was
a slight decrease in glucose concentrations in the 200-ppb chromium group, although only the differences on d 55 were significant.
Triglyceride levels in both chromium groups were lower than the control group with marked differences in the 400-ppb chromium
group. HDL cholesterol levels increased in both treatment groups compare to control, although the differences in the 400-ppb
chromium group on d 40 were significant. Serum Cr concentrations slightly but not significantly increased in both chromium
groups. No significant differences were found in total and LDL cholesterol, total protein, albumin, ALT, AST, and GGT levels.
In conclusion, chromium supplementation may affect carbohydrate and lipid metabolisms and lipid deposition in lambs. 相似文献
28.
Activation of MAPK homologues by elicitors in tobacco cells 总被引:20,自引:3,他引:17
Angela Lebrun-Garcia Fatma Ouaked Annick Chiltz Alain Pugin 《The Plant journal : for cell and molecular biology》1998,15(6):773-781
Elicitors of plant defence reactions (such as cryptogein, an elicitin produced by Phytophthora cryptogea , or oligogalacturonides (OGs)), induced in tobacco cell suspensions ( Nicotiana tabacum var Xanthi) a rapid and transient activation of two protein kinases (PKs) with apparent molecular masses of 50 and 46 kDa, respectively. These PKs activated and phosphorylated at tyrosine residues, phosphorylated myelin basic protein (MBP) at serine/threonine residues. Both are recognized by anti-MAPK antibodies. The two MBP kinases possessed the same kinetics of activation, and their activation depended, to the same extent, on different exogenously applied compounds (staurosporine, lanthanum, EGTA). We demonstrate here that the activation of the MBP kinases is calcium dependent and sensitive to staurosporine, a protein kinase inhibitor which annihilates all known responses of tobacco cells to cryptogein. The activation of MBP kinases appeared to be independent of the production of active oxygen species (AOS) and insensitive to calyculin A, a protein phosphatase type 1 and 2A inhibitor. The activation of MAPKs is discussed in relation to the early responses induced by cryptogein. 相似文献
29.