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91.
Polidori C  Luciani F  Fedeli A  Geary N  Massi M 《Peptides》2003,24(9):1441-1444
Leptin, a hormone secreted by the adipocytes and involved in feeding and energy balance control, has been proposed to modulate alcohol craving in mice and humans. This study evaluated whether leptin modulates alcohol intake in Marchigian Sardinian alcohol-preferring (msP) rats. Rats were offered 10% ethanol either 2h per day at the beginning of dark period of the 12:12h light/dark cycle, or 24h per day. Leptin was injected into the lateral ventricle (LV), the third ventricle (3V), or intraperitoneally (IP) once a day, 1h before the onset of the dark period. Neither acute nor chronic (9 days) leptin injections (1 or 8microg per rat) into the LV or 3V modified ethanol intake in male msP rats, offered ethanol 2h per day. Chronic LV injection of leptin (8 or 32 microg per rat in male rats and 8 or 16 microg per rat in female rats for 7 days), or chronic IP injections of leptin (1mg/kg in male rats for 5 days) failed to modify the intake of ethanol, offered 24h per day. Finally, chronic LV leptin injections (8 or 32 microg per rat for 12 days) did not modify ethanol intake in male msP rats, adapted to ad libitum access to ethanol and then tested after a 6-day period of ethanol deprivation. In contrast, in most of these conditions leptin significantly reduced food intake. These data do not support a role for leptin in alcohol intake, preference, or craving in msP rats.  相似文献   
92.
The selenoprotein phospholipid hydroperoxide glutathione peroxidase (PHGPx) accounts for almost the entire selenium content of mammalian testis. PHGPx is abundantly expressed in spermatids as active peroxidase but is transformed to an oxidatively inactivated protein in mature sperm, where it is a major constituent of the mitochondrial capsule in the midpiece. Male infertility in selenium-deficient animals, which is characterized by impaired sperm motility and morphological midpiece alterations, is considered to result from insufficient PHGPx content. We studied the relationship between sperm PHGPx, measured as rescued activity, and human fertility. Sperm specimens from 75 infertile men and 37 controls were analyzed for fertility-related parameters according to World Health Organization criteria. The PHGPx protein content was estimated after reductive solubilization of the spermatozoa by measuring the rescued PHGPx activity. Rescued PHGPx activity of infertile men ranged significantly below that of controls (93.2 +/- 60.1 units/mg sperm protein vs. 187.5 +/- 55.3 units/mg) and was particularly low in oligoasthenozoospermic specimens (61.93 +/- 45.42 units/mg; P < 0.001 compared with controls and asthenozoospermic samples). Rescued PHGPx activity was correlated positively with viability, morphological integrity, and most profoundly forward motility (r = 0.35, 0.44, and 0.45, respectively). In isolated motile samples, motility decreased faster with decreasing PHGPx content. In humans, PHGPx appears to be indispensable for structural integrity of spermatozoa and to codetermine sperm motility and viability. Because the content of PHGPx, irrespective of the cause of alteration, is correlated with fertility-related parameters, PHGPx can be considered a predictive measure for fertilization capacity.  相似文献   
93.
Rubus imperialis, Artemia salina, 3-O-methylellagic-4'-O-alpha-rhamnose Acid Screening of different extracts, fractions and compounds from Rubus imperialis Chum. Schl. (Rosaceae) has been conduced using the brine shrimp microwell cytotoxicity assay. Three parts of the plant (methanolic extract from leaves, roots and stems), three fractions from roots (hexane, ethyl acetate and butanol) and three isolated compounds (niga-ichigoside F1, 23-hydroxytormentic acid, ellagic acid derivative) were tested. The most promising material (LC50 <1000 microg/ml) were the methanolic extract and ethyl acetate fraction from roots. However, there was little correlation observed in the degree of toxicities observed between the isolated compounds. On the other hand, the cytotoxicity and in vivo assays confirmed the hypoglycemic activity of methanolic extract and validated the Brazilian popular use of R. imperialis as an antidiabetic agent.  相似文献   
94.
Severe influenza infections are complicated by acute lung injury, a syndrome of pulmonary microvascular leak. The pathogenesis of this complication is unclear. We hypothesized that human influenza could directly infect the lung microvascular endothelium, leading to loss of endothelial barrier function. We infected human lung microvascular endothelium with both clinical and laboratory strains of human influenza. Permeability of endothelial monolayers was assessed by spectrofluorimetry and by measurement of the transendothelial electrical resistance. We determined the molecular mechanisms of flu-induced endothelial permeability and developed a mouse model of severe influenza. We found that both clinical and laboratory strains of human influenza can infect and replicate in human pulmonary microvascular endothelium, leading to a marked increase in permeability. This was caused by apoptosis of the lung endothelium, since inhibition of caspases greatly attenuated influenza-induced endothelial leak. Remarkably, replication-deficient virus also caused a significant degree of endothelial permeability, despite displaying no cytotoxic effects to the endothelium. Instead, replication-deficient virus induced degradation of the tight junction protein claudin-5; the adherens junction protein VE-cadherin and the actin cytoskeleton were unaffected. Over-expression of claudin-5 was sufficient to prevent replication-deficient virus-induced permeability. The barrier-protective agent formoterol was able to markedly attenuate flu-induced leak in association with dose-dependent induction of claudin-5. Finally, mice infected with human influenza developed pulmonary edema that was abrogated by parenteral treatment with formoterol. Thus, we describe two distinct mechanisms by which human influenza can induce pulmonary microvascular leak. Our findings have implications for the pathogenesis and treatment of acute lung injury from severe influenza.  相似文献   
95.
The elucidation of the structure and stereochemistry of cynanchoside, a new highly oxygenated iridoid glucoside isolated from Macfadyena cynanchoides (Bignoniaceae), has been accomplished using mainly 1H and 13C NMR spectral data and further confirmed by simple chemical transformations.  相似文献   
96.
The amino acid sequence of wheatwin1, a monomeric protein of 125 residues isolated from wheat kernel (variety S. Pastore), is reported. Wheatwin1 is highly homologous (95%) to barwin, a protein from barley seed, which was shown to be related to the C-terminal domain of two proteins encoded by the wound-induced geneswin1 andwin2 in potato and to a protein encoded by the same domain of the hevein gene (hev1) in rubber tree. Similarly to barwin, wheatwin1 contains six cysteine residues all linked in disulfide bridges and the N-terminal residue is pyroglutamate. Moreover, structural studies performed on wheatwin1 andwin1 protein by predictive methods demonstrated that these proteins and barwin are closely related in the secondary structure also. The high level of homology found with the product ofwin1,win2, andhev1 genes strongly suggests that barwin and wheatwin1 play a common role in the mechanism of plant defence.  相似文献   
97.
Abstract A combined polymerase chain reaction and restriction endonuclease (RE) enzyme assay was developed to discriminate between Campylobacter coli and Campylobacter jejuni . Amplimers of the FlaA gene obtained by PCR were digested with Alu I and Hin fI to distinguish C. coli from C. jejuni . With Alu I digestion C. jejuni -specific bands were observed at 110, 140 and 160 bp and C. coli -specific bands at 293 and 147 bp. C. jejuni -specific bands of 349 and 109 bp were found by Hin fI digestion but Hin fI did not digest the Fla A amplimer of C. coli . This combined technique is fast and easy to perform, and distinguishes the two campylobacters unequivocally.  相似文献   
98.
This study describes the GC‐FID, GC/MS, GC‐O, and enantioselective GC analysis of the essential oil hydrodistilled from leaves of Lepechinica mutica (Lamiaceae), collected in Ecuador. GC‐FID and GC/MS analyses allowed the characterization and quantification of 79 components, representing 97.3% of the total sample. Sesquiterpene hydrocarbons (38.50%) and monoterpene hydrocarbons (30.59%) were found to be the most abundant volatiles, while oxygenated sesquiterpenes (16.20%) and oxygenated monoterpenes (2.10%) were the minor components. In order to better characterize the oil aroma, the most important odorants, from the sensorial point of view, were identified by Aroma Extract Dilution Analysis (AEDA) GC‐O. They were α‐Pinene, β‐Phellandrene, and Dauca‐5,8‐diene, exhibiting the characteristic woody, herbaceus, and earthy odors, respectively. Enantioselective GC analysis of Lmutica essential oil revealed the presence of twelve couples and two enantiomerically pure chiral monoterpenoids. Their enantiomeric excesses were from a few percent units to 100%. Moreover, the essential oil exhibited moderate in vitro activity against five fungal strains, being especially effective against Mcanis, which is a severe zoophilic dermatophyte causal agent of pet and human infections.  相似文献   
99.
The effect of environmental factors is essential to the success of parasitoids as biological control agents, as it determines their foraging activity, development, and survival. The larval‐pupal parasitoid wasp Aganaspis daci (Weld) (Hymenoptera: Figitidae) is known to have a very low fertility (i.e., offspring production) in the field in certain Mediterranean areas, probably due to its inability to efficiently oviposit under such climatic conditions. In this study, the percentage of parasitism and induced mortality (mortality of host pupae attributed to parasitoids, from which adults do not emerge) caused by this wasp to the Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), was assessed under field conditions across 1 year, using medfly‐infested apples and parasitoid‐confined release in a lemon orchard of southeastern Spain. As A. daci is known to have very few emergences in the field, fertility was assessed in the laboratory from parasitized pupae recovered from the field. We found average parasitism rates of 27% and high induced mortality rates of 66% under field conditions. Consequently, medfly population reduction (total mortality of C. capitata caused by A. daci, i.e., induced mortality + % parasitism) was, on average, 87%. Parasitism and induced mortality varied throughout the year, depending on the average temperature and relative humidity. The interaction of these factors resulted in the highest parasitism rates at low mean temperature and humidity values; likewise, the highest percentages of induced mortality were obtained with a combination of high mean temperature and low mean humidity values. In conclusion, A. daci may exert a strong impact on medfly populations, being a good candidate for inundative field releases for the management of C. capitata in the Mediterranean Basin.  相似文献   
100.
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