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301.
302.
Populations of Oriental White-backed Vulture (Gyps bengalensis) and Long-billed Vulture (Gyps indicus) declined dramatically by 95–100% on the Indian subcontinent in during the mid-1990s. The study reported here was conducted
in Pakistan to compare the population size, breeding success, patterns of mortality and sex ratios among dead vultures and
newly hatched nestlings of G. bengalensis and G. indicus at Toawala (TW) and Nagar Parkar (NP), respectively, during the breeding seasons 2005/2006 and 2006/2007. At TW, diclofenac
poisoning was most likely responsible for the high mortality and sex ratio imbalance among dead G. bengalensis, where vulture counts and breeding success declined quickly during the study period. However, at NP no significant difference
in population size, breeding success and annual mortality of G. indicus was recorded during the study period. A sex ratio imbalance was detected among nestlings of G. bengalensis, with 68% males and 32% females. In contrast, the sex ratio did not differ significantly in G. indicus. 相似文献
303.
Marie-Claude Senut Seema Azher Frank L. Margolis Kamakshi Patel Ahmad Mousa Arshad Majid 《Cell and tissue research》2009,337(1):45-61
Carnosine-like peptides (carnosine-LP) are a family of histidine derivatives that are present in the nervous system of various
species and that exhibit antioxidant, anti-matrix-metalloproteinase, anti-excitotoxic, and free-radical scavenging properties.
They are also neuroprotective in animal models of cerebral ischemia. Although the function of carnosine-LP is largely unknown,
the hypothesis has been advanced that they play a role in the developing nervous system. Since the zebrafish is an excellent
vertebrate model for studying development and disease, we have examined the distribution pattern of carnosine-LP in the adult
and developing zebrafish. In the adult, immunoreactivity for carnosine-LP is specifically concentrated in sensory neurons
and non-sensory cells of the olfactory epithelium, the olfactory nerve, and the olfactory bulb. Robust staining has also been
observed in the retinal outer nuclear layer and the corneal epithelium. Developmental studies have revealed immunostaining
for carnosine-LP as early as 18 h, 24 h, and 7 days post-fertilization in, respectively, the olfactory, corneal, and retinal
primordia. These data suggest that carnosine-LP are involved in olfactory and visual function. We have also investigated the
effects of chronic (7 days) exposure to carnosine on embryonic development and show that 0.01 μM to 10 mM concentrations of
carnosine do not elicit significant deleterious effects. Conversely, treatment with 100 mM carnosine results in developmental
delay and compromised larval survival. These results indicate that, at lower concentrations, exogenously administered carnosine
can be used to explore the role of carnosine in development and developmental disorders of the nervous system.
This research was supported in part by an Intramural Research Grant Program Award from Michigan State University (no. 06-IRGP-899
to M.C.S.) and a grant from the National Institutes of Health (no. DC-03112 to F.L.M.). 相似文献
304.
Aparna Asok Esha Arshad C. Jasmin S. Somnath Pai I. S. Bright Singh A. Mohandas Abdulaziz Anas 《Microbial biotechnology》2012,5(1):59-68
We propose antimicrobial photodynamic therapy (aPDT) as an alternative strategy to reduce the use of antibiotics in shrimp larviculture systems. The growth of a multiple antibiotic resistant Vibrio harveyi strain was effectively controlled by treating the cells with Rose Bengal and photosensitizing for 30 min using a halogen lamp. This resulted in the death of > 50% of the cells within the first 10 min of exposure and the 50% reduction in the cell wall integrity after 30 min could be attributed to the destruction of outer membrane protein of V. harveyi by reactive oxygen intermediates produced during the photosensitization. Further, mesocosm experiments with V. harveyi and Artemia nauplii demonstrated that in 30 min, the aPDT could kill 78.9% and 91.2% of heterotrophic bacterial and Vibrio population respectively. In conclusion, the study demonstrated that aPDT with its rapid action and as yet unreported resistance development possibilities could be a propitious strategy to reduce the use of antibiotics in shrimp larviculture systems and thereby, avoid their hazardous effects on human health and the ecosystem at large. 相似文献
305.
Long-term field metal extraction by Pelargonium: phytoextraction efficiency in relation to plant maturity 总被引:2,自引:0,他引:2
Shahid M Arshad M Kaemmerer M Pinelli E Probst A Baque D Pradere P Dumat C 《International journal of phytoremediation》2012,14(5):493-505
The long length of periods required for effective soil remediation via phytoextraction constitutes a weak point that reduces its industrial use. However, these calculated periods are mainly based on short-term and/or hydroponic controlled experiments. Moreover, only a few studies concern more than one metal, although soils are scarcely polluted by only one element. In this scientific context, the phytoextraction of metals and metalloids (Pb, Cd, Zn, Cu, and As) by Pelargonium was measured after a long-term field experiment. Both bulk and rhizosphere soils were analyzed in order to determine the mechanisms involved in soil-root transfer. First, a strong increase in lead phytoextraction was observed with plant maturity, significantly reducing the length of the period required for remediation. Rhizosphere Pb, Zn, Cu, Cd, and As accumulation was observed (compared to bulk soil), indicating metal mobilization by the plant, perhaps in relation to root activity. Moreover, metal phytoextraction and translocation were found to be a function of the metals' nature. These results, taken altogether, suggest that Pelargonium could be used as a multi-metal hyperaccumulator under multi-metal soil contamination conditions, and they also provide an interesting insight for improving field phytoextraction remediation in terms of the length of time required, promoting this biological technique. 相似文献
306.
M Zuber KM Zia IA Bhatti Z Ali MU Arshad MJ Saif 《International journal of biological macromolecules》2012,51(5):743-748
This work presents the comparative study on the dyeing behavior of cellulose fibers in alkaline solutions and under the influence of UV radiation. The cellulosic fabrics were pretreated followed by conventional mercerization technique or treatment with UV irradiation. For different time duration the reorganization of cellulose fibers by swelling treatments in alkaline solutions results in numerous structural modifications, causing changes of their accessibility and/or reactivity. The results revealed that the swelling of the cellulosic fibers depends on type of pre-treatment, dose of the radiation and the concentration of alkaline solution used. SEM analysis confirmed that UV irradiation of the cellulosic fibers leads to a higher swelling in comparison with any concentration of NaOH treatment. In comparison of both the treatments, the mercerized cellulosic fibers have shown better tear and tensile strength as compared to the untreated and UV irradiated one. There is adverse effect of UV radiation on the mechanical properties of UV radiation. Moreover, no loss in weight was observed after exposing the cellulose fabrics surface to UV radiation. 相似文献
307.
K. D. Simon Y. Bakar A. G. Mazlan C. C. Zaidi A. Samat A. Arshad S. E. Temple N. J. Brown-Peterson 《Environmental Biology of Fishes》2012,93(4):491-503
Various aspects of the reproductive biology of two archer fishes Toxotes chatareus and Toxotes jaculatrix were studied to describe gonad development, spawning season, sex ratio, and fecundity. Spawning season was assessed using
monthly changes in gonadosomatic index (GSI) and histological inspection of the gonads. Both species exhibit two modes of
oocytes; a mode of small primary growth oocytes and a single mode that increases with size as oocytes sequester vitellogenin
and undergo maturation, showing the synchronous oocyte development typical of total spawners. Based on GSI values and advanced
stages of oocyte maturity, T. chatareus and T. jaculatrix, females appear to spawn from November to December. The average fecundity of female T. chatareus was 55 000 ± 5538 eggs, and T. jaculatrix was 50 000 ± 3440 eggs; fecundity ranged from 20 000 to 150 000 eggs for both species, with relative fecundities of 600 to
1100 eggs/g body weight, and a mean value of 800 ± 32 for T. chatareus; relative fecundity ranged from 500 to 1100 with a mean value of 700 ± 23 for T. jaculatrix. Sex ratio, defined as the proportion of males to females, was 2.2 and 2.5 in T. chatareus and T. jaculatrix, respectively. The apparent abundance of males in samples could be due to females being positioned lower in the water column
and therefore being sampled less frequently. Our results indicate that in both species, spawning occurs between the months
of November and December during the monsoon season, which provides the mangrove coastal waters inhabited by these species
with an abundance of food resources and additional floodplain nursery habitat for larvae and juveniles. 相似文献
308.
RNA silencing technology has become the tool of choice for inducing resistance against viruses in plants. A significant discovery
of this technology is that double-stranded RNA (dsRNA), which is diced into small interfering RNAs (siRNAs), is a potent trigger
for RNA silencing. By exploiting this phenomenon in transgenic plants, it is possible to confer high level of virus resistance
by specific targeting of cognate viral RNA. In order to maximize the efficiency and versatility of the vector-based siRNA
approach, we have constructed a chimeric expression vector containing three partial gene sequences derived from the ORF2 gene
of Potato virus X, Helper Component Protease gene of Potato virus Y and Coat protein gene of Potato leaf roll virus. Solanum tuberosum cv. Desiree and Kuroda were transformed with this chimeric gene cassette via Agrobacterium tumefaciens-mediated transformation and transgenic status was confirmed by PCR, Southern and double antibody sandwich ELISA detection.
Due to simultaneous RNA silencing, as demonstrated by accumulation of specific siRNAs, the expression of partial triple-gene
sequence cassette depicted 20% of the transgenic plants are immune against all three viruses. Thus, expression of a single
transgene construct can effectively confer resistance to multiple viruses in transgenic plants. 相似文献
309.
Arshad Desai Elizabeth A. Holleran John P. Incardona Orion Weiner Robert O. J. Weinzierl Vas Ponnambalam Paul A. Slesinger Joe William Ramos Michelle L. Matter Richard Benton Neil Hukriede Michael Tsang 《Current opinion in cell biology》2001,13(6):649
A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in cell biology. 相似文献
310.
KC Lødrup Carlsen S Roll KH Carlsen P Mowinckel AH Wijga B Brunekreef M Torrent G Roberts SH Arshad I Kull U Krämer A von Berg E Eller A Høst C Kuehni B Spycher J Sunyer CM Chen A Reich A Asarnoj C Puig O Herbarth JM Mahachie John K Van Steen SN Willich U Wahn S Lau T Keil;GALEN WP . ‘Birth Cohorts’ working group 《PloS one》2012,7(8):e43214