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排序方式: 共有219条查询结果,搜索用时 31 毫秒
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Rehman MU Tahir M Ali F Qamar W Lateef A Khan R Quaiyoom A Oday-O-Hamiza Sultana S 《Molecular and cellular biochemistry》2012,365(1-2):119-127
Cyclophosphamide (CPM), an alkylating agent is used as an immunosuppressant in rheumatoid arthritis and in the treatment of several cancers as well. In this study, Ellagic acid (EA), a naturally occurring plant polyphenol, was evaluated for its antigenotoxicity and antioxidant efficacy against the CPM-induced renal oxidative stress and genotoxicity in Swiss albino mice. The mice were given a prophylactic treatment of EA orally at a dose of 50 and 100 mg/kg body weight (b wt) for seven consecutive days before the administration of a single intraperitoneal (i.p.) injection of CPM at 50 mg/kg b wt. The modulatory effects of EA on CPM-induced nephrotoxicity and genotoxicity were investigated by assaying oxidative stress biomarkers, serum kidney toxicity markers, DNA fragmentation, alkaline unwinding assay, micronuclei (MN) assay, and by histopathological examination of kidney tissue. A single intraperitoneal administration of CPM in mice increased malondialdehyde level with depletion in glutathione content, antioxidant enzymes activities, viz. glutathione peroxidase, glutathione reductase, catalase, quinone reductase, induced DNA strand breaks, and MN induction. EA oral administration at both doses caused significant reduction in their levels, restoration in the activities of antioxidant enzymes, reduction in MN formation, and DNA fragmentation. Serum toxicity marker enzymes like BUN, creatinine, and LDH were also increased after CPM treatment which was significantly decreased in EA pretreated groups. Present findings suggest a prominent role of EA against CPM-induced renal injury, DNA damage, and genotoxicity. 相似文献
54.
Maqsood Qamar Dilnawaz Ahmed Gardezi Muhammad Iqbal 《Journal of Phytopathology》2012,160(11-12):628-636
The non‐durable nature of hypersensitive (race‐specific) resistance has stimulated scientists to search for other options such as race‐non‐specific resistance to provide long‐lasting protection against plant diseases. Adult plant resistance gene complex Lr34/Yr18 confers a dual race‐non‐specific type of resistance to wheat against stripe rust (Puccinia striiformis f. sp. tritici) and leaf rust (P. triticina Eriks). This study was conducted to evaluate 59 spring bread wheat (Triticum aestivum L.) genotypes for the presence of the Lr34/Yr18‐linked csLV34 allele using STS marker csLV34 and to determine the effect of this gene complex on the components of partial resistance in wheat to leaf/stripe rust. Lr34/Yr18‐linked csLV34 allele was detected only in 12 genotypes, namely Iqbal 2000, NR‐281, NR 354, NR 363, NR 364, NR 366, NR 367, NR 370, NR 376, 4thEBWYT 509, 4thEBWYT 510 and 4thEBWYT 518. Eleven genotypes showing the amplified Lr34/Yr18‐linked allele were further studied for the assessment of the effect of Lr34/Yr18 on components of partial resistance along with nine genotypes lacking this gene complex. Both stripe and leaf rusts were studied separately. The components of partial resistance including latency period (LP) and infection frequency (IF) were studied on primary leaf (seedling stage), fourth leaf and fully expanded young flag leaf (adult plant stage). Both the stripe and leaf rust fungi showed a prolonged LP and reduced IF on genotypes carrying Lr34/Yr18 gene complex. Generally, a longer LP was associated with a reduced IF at all growth stages. Although significant effect of Lr34/Yr18 gene complex on LP and IF was observed almost at all three growth stages, the effect was more pronounced at flag leaf. This suggested that Lr34/Yr18 gene complex is more effective at later stages of plant growth. 相似文献
55.
Qamar AA Burke SK Lafleur JD Ding BC Bland KS Wong MD Gustafson PN Blair AT Franano FN 《Biotechnology and applied biochemistry》2012,59(1):22-28
PRT-201 is a recombinant human pancreatic elastase under development as a treatment for blood vessels to promote hemodialysis access patency. Proteases such as elastase are normally inactivated by antiproteases such as alpha 1-antitrypsin. It is unknown if serum from patients with alpha 1-antitrypsin deficiency will inhibit PRT-201 elastase activity. An assay for PRT-201 elastase activity in the presence of serum was developed and validated. PRT-201 elastase activity inhibition curves were developed using serum and also using purified alpha 1-antitrypsin and alpha 2-macroglobulin. Serum from 15 patients with documented alpha 1-antitrypsin deficiency, some of whom were receiving alpha 1-antitrypsin augmentation therapy, and four normal volunteers was analyzed. Serum from normal volunteers and patients with alpha 1-antitrypsin deficiency completely inactivated PRT-201 elastase activity in vitro. In the alpha 1-antitrypsin-deficient patients, the volume of serum necessary to inhibit elastase activity was related to the serum concentration of alpha 1-antitrypsin and augmentation therapy. Purified alpha 1-antitrypsin and alpha 2-macroglobulin were each alone capable of completely inhibiting PRT-201 elastase activity. It is unlikely that the use of PRT-201 will be associated with negative outcomes in patients with alpha 1-antitrypsin deficiency. 相似文献
56.
Zeb D. Tonkin Paul Humphries Peter A. Pridmore 《Environmental Biology of Fishes》2006,76(2-4):303-315
Investigations into the feeding of the early stages of fishes can provide insights into processes influencing recruitment. In this study, we examined ontogenetic changes in morphology and feeding behaviour of two native Australian freshwater species, Murray cod, Maccullochella peelii peelii, and golden perch, Macquaria ambigua, and the alien species, common carp, Cyprinus carpio. Murray cod free embryos are large and well developed at the onset of feeding, whereas the other two species begin exogenous feeding much younger and are smaller and less-developed. Carp commence exogenous feeding 3 days earlier than golden perch, and show more advanced development of the eyes and ingestive apparatus. We conducted feeding experiments, presenting larvae of the three species with a standardised prey mix (comprising equal numbers of small calanoid copepods, large calanoid copepods, small Daphnia, and large Daphnia). Larvae of most tested ages and species showed a preference for mid-sized prey (300–500 μm wide). This was true even when their gapes substantially exceeded the largest prey offered. Daphnia were consumed more than similar-sized copepods. The results of this study suggest that survival through their larval period will be threatened in all three species if catchable prey <500 μm in width are not available throughout such time. They also suggest that interspecific competition for prey may occur, especially when larvae are very young. The precocious development of structures involved in feeding and the extended transition from endogenous to exogenous feeding of early carp larvae are likely to have contributed to the success of this species since its introduction to Australia. 相似文献
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Zerjal T Xue Y Bertorelle G Wells RS Bao W Zhu S Qamar R Ayub Q Mohyuddin A Fu S Li P Yuldasheva N Ruzibakiev R Xu J Shu Q Du R Yang H Hurles ME Robinson E Gerelsaikhan T Dashnyam B Mehdi SQ Tyler-Smith C 《American journal of human genetics》2003,72(3):717-721
We have identified a Y-chromosomal lineage with several unusual features. It was found in 16 populations throughout a large region of Asia, stretching from the Pacific to the Caspian Sea, and was present at high frequency: approximately 8% of the men in this region carry it, and it thus makes up approximately 0.5% of the world total. The pattern of variation within the lineage suggested that it originated in Mongolia approximately 1,000 years ago. Such a rapid spread cannot have occurred by chance; it must have been a result of selection. The lineage is carried by likely male-line descendants of Genghis Khan, and we therefore propose that it has spread by a novel form of social selection resulting from their behavior. 相似文献
59.
Most mammalian species express high concentrations of ALDH3A1 in corneal epithelium with the exception of the rabbit, which expresses high amounts of ALDH1A1 rather than ALDH3A1. Several hypotheses that involve catalytic and/or structural functions have been postulated regarding the role of these corneal ALDHs. The aim of the present study was to characterize the biochemical properties of the rabbit ALDH1A1. We have cloned and sequenced the rabbit ALDH1A1 cDNA, which is 2,073 bp in length (excluding the poly(A+) tail), and has 5' and 3' nontranslated regions of 46 and 536 bp, respectively. This ALDH1A1 cDNA encodes a protein of 496 amino acids (Mr = 54,340) that is: 86-91% identical to mammalian ALDH1A1 proteins, 83-85% identical to phenobarbital-inducible mouse and rat ALDH1A7 proteins, 84% identical to elephant shrew ALDH1A8 proteins (eta-crystallins), 69-73% identical to vertebrate ALDH1A2 and ALDH1A3 proteins, 65% identical to scallop ALDH1A9 protein (omega-crystallin), and 55-57% to cephalopod ALDH1C1 and ALDH1C2 (omega-crystallins). Recombinant rabbit ALDH1A1 protein was expressed using the baculovirus system and purified to homogeneity with affinity chromatography. We found that rabbit ALDH1A1 is catalytically active and efficiently oxidizes hexanal (Km = 3.5 microM), 4-hydroxynonenal (Km = 2.1 microM) and malondialdehyde (Km = 14.0 microM), which are among the major products of lipid peroxidation. Similar kinetic constants were observed with the human recombinant ALDH1A1 protein, which was expressed and purified using similar experimental conditions. These data suggest that ALDH1A1 may contribute to corneal cellular defense against oxidative damage by metabolizing toxic aldehydes produced during UV-induced lipid peroxidation. 相似文献
60.
Enclosure design and the use of enclosure space influence the activity budget of captive leopards. The study laid out in grids all enclosures on the base map and segregated these grids into 4 zones. Every 5 min, the study recorded the proportion of time spent in these zones with the leopards' behavior. Captive leopards most frequently used the “edge ”zone. Almost all leopards used the edge zone for stereotypic pacing, the “back ”zone for resting, and the “other ”zone for activity. The study positively correlated the proportion of time spent in the “enriched ”zone with activity levels exhibited by leopards housed in some enclosures and with resting in others. Thus, the study segregated structural objects in the enriched zone into activity-related features (e.g., logs) and rest-related features (e.g., trees and sleeping platforms). Compared with individuals housed in barren enclosures, leopards housed in structurally enriched on-exhibit enclosures exhibited higher levels of activity. Enclosure design was found to be an important factor influencing the welfare of leopards in captivity. 相似文献