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51.
Nonylphenols (NP) are endocrine-disruptors known to be widely present in our environment. This study evaluated the effects of 4-n-NP on neurobehavioral development and memory capacity after perinatal exposure on the offspring rats. Dams were gavaged with 4-n-NP (0, 50 and 200 mg/kg/day) from gestational day 5 to postnatal day (PND) 21. Dams exposed to the higher dose lost weight during gestation and had a longer gestational duration. Juvenile female pups of the 200 mg 4-n-NP/kg/day group were lighter. Their thyroid somatic index (TSI) was also affected. For male pups, a decrease of TSI at weaning for the 200 mg 4-n-NP/kg/day group and an increase of GSI for the 50 mg 4-n-NP/kg/day group were observed. Physical maturation (incisives and eyes) were likewise affected. In open field (OF) tests, females were more active than males. In the first OF (PND 36), a treatment effect was observed only for males, particularly for the high dose group, which became as active as females. The second OF (PND 71) showed few differences between groups (treated vs control), the gender difference whatever the dose was not abolished. In the Morris Water Maze test, the study of the first 30 s showed that females (200 mg/kg/day) were mainly affected. Their performances were improved by 4-n-NP. These effects were particularly important for the first short-term memory test and observed to a lesser extent in the second evaluation of the long-term memory (PND 69). These data showed that perinatal 4-n-NP exposure induced behavioral and neuro-developmental impairments from 50 mg/kg/day.  相似文献   
52.
To explore an efficient photocatalyst for NO pollution, a direct Z-scheme photocatalytic system is successfully fabricated by coupling Bi2WO6 with NH2-UiO-66 via a simple hydrothermal synthesis technique. The Z-scheme system promotes the NO photocatalytic oxidation activity with an optimum NO removal rate of 79%, which is 2.7 and 1.2 times that obtained by using only pristine Bi2WO6 and NH2-UiO-66, respectively. Simultaneously, superior selectivity for converting NO to NO3/NO2 is observed. The enhanced photocatalytic performance of the Bi2WO6/NH2-UiO-66 hybrids is attributed to the following two aspects: (i) large specific area of NH2-UiO-66, which exposes more active sites and is beneficial to the adsorption and activation of NO; (ii) outstanding Z-scheme structure constructed between BiWO6 and NH2-UiO-66, which can improve the efficiency of the separation of electron–hole pairs and preserves the strong oxidation ability of hybrids. ESR analysis shows that ·O2 and ·OH contribute to NO removal. A possible photocatalytic mechanism of NO oxidation on the direct Z-scheme photocatalyst (BWO/2NU) under visible light irradiation is proposed. This work displays the BWO/2NU hybrid''s potential for treating low-concentration air pollutants, and the proposed Z-scheme photocatalyst design and promotion mechanism may inspire more rational synthesis of highly efficient photocatalysts for NO removal.

To explore an efficient photocatalyst for NO pollution, a direct Z-scheme photocatalytic system is successfully fabricated by coupling Bi2WO6 with NH2-UiO-66 via a simple hydrothermal synthesis technique.  相似文献   
53.
This paper reports on oocyte cryopreservation efficacy in Italy with respect to successful IVF from 2005 to 2007, presenting data from 193 centres collected by the Italian National Register. Post-thawing survival rates, number of transferred embryos, implantation rates and clinical pregnancy rates per transfer with respect to frozen/vitrified oocytes (FVO) were analysed. These numbers were compared with those obtained using frozen embryos or fresh oocytes. A total of 121,708 cycles were initiated, of which, 7.1% (8682) were FVO cycles and 2.4% (2952) were frozen embryo cycles. Of the 81,786 FVO, 52.5% (42,917) were thawed and 26.9% (22,005) inseminated. Of those inseminated, 68.0% (14,966) yielded good embryos. These numbers were significantly lower than those using fresh oocytes in which 77.9% (197,242; fresh oocytes versus FVO P < 0.001) of inseminated oocytes generated good embryos. Implantation rate using FVO was 6.9%, which was significantly lower than that using fresh oocytes (13.5%; P < 0.001) and frozen embryos (8.8%; P < 0.001). Pregnancy rate per transfer using FVO was 12.5% and significantly lower than that using fresh oocytes (24.9%; P < 0.001) or frozen embryos (16.4%; P < 0.001). There were 505 deliveries after IVF with FVO and 582 babies.  相似文献   
54.
Industrial frying oils continuously evolve as efforts are made to improve their overall quality because of health concerns. The objectives of this study were to determine fatty acids, tocopherols, sterols, and phytosterol oxidation products (POPs) in French fries, which are commonly consumed in Sweden. Five different commercial prefried French fries and four samples of French fries prepared in different fast food restaurants were studied. POPs were determined with transesterification, purification of oxides by solid-phase extraction, quantification by GC and identification by GC–MS. The method of POPs analysis was validated by spiking with standard samples of cholesterol oxidation products which showed good recoveries of those compounds. The results showed that the samples were generally prepared in frying oils dominated by saturated and monounsaturated fatty acids, except for two prefried samples which were dominated by a di-unsaturated fatty acid. In prefried samples, only α-tocopherol could be quantified whereas restaurant samples generally contained both α- and γ-tocopherols. Sitosterol was the dominating sterol in the all samples. The POPs content in prefried commercial French fries ranged from 0.01 to 0.21 mg/100 g, and the values in restaurant samples were considerably higher, ranging from 0.15 to 0.81 mg/100 g. The increased levels of POPs in the restaurant samples may be partially due to higher contents of fat, saturated and monounsaturated fatty acids and sterols. Further studies are required to identify other factors for the formation of POPs in French fries and their long-term implications to human health.  相似文献   
55.
目的探讨醋酸铅及NF-κB抑制剂吡咯烷二硫氨基甲酸(PDTC)对核转录因子-kappaB(NF-κB)转录活性的影响。方法将大鼠肾上腺嗜铬细胞瘤细胞(PC12细胞)暴露于不同浓度的醋酸铅0、12.5、25、50、100、200、400、800和1600μmol/L,采用四唑盐比色实验(MTT)检测IC50值。用脂质体将pNF-κB-Luc报告基因质粒转染入PC12细胞,转染后的PC12细胞分别暴露于不同浓度的醋酸铅(100、200和400μmol/L)及不同浓度醋酸铅加PDTC100μmol/L,24小时后采用萤光素酶检测试剂盒检测萤光素酶活性。结果用不同浓度的醋酸铅处理细胞24小时,其生长增殖受到不同程度的抑制,且呈现出剂量-反应关系,其IC50值为(533.966±100.830)μmol/L。用不同浓度的醋酸铅处理转染后的PC12细胞24小时,结果显示:PDTC对照组萤光素酶活性较空白对照组降低(P<0.01);铅处理组萤光素酶活性较空白对照组高(P<0.01),且具有剂量依赖性;铅 PDTC联合作用组与PDTC对照组相比,PC12细胞内萤光素酶活性增高(P<0.01)。结论醋酸铅可诱导PC12细胞的NF-κB转录活性升高。  相似文献   
56.
Objective To observe the morphological changes in in vitro growth of preantral follicle isolated from prepuberal mice and to assess impacts of gonadotropin (Gn), insulin transferrin selenium (ITS) and epidermal growth factor (EGF) on their development. Methods Early preantral mice follicles (90-130μm diameter) were mechanical isolated and selected from 2 weeks' old mice and then cultured in alpha-minimal essential medium (α-MEM) with or without Gn, ITS and EGF. The preantral follicles were cultured singly in 20 miovliters droplets for up to 14 d. The medium was replaced and the .follicles were observed everyday. Granulosa cells (GC) prolification, antrum formation and oocyte maturation were recorded. Results The medium with Gn supported preantral follicle culture in vitro, during which they retained a three-dimensional structure, maintained oocytes viability and increased in diameter and number of somatic cells'. Preantral follicles cultured in Gn medium grew obviously, while those without Gn grew slowly and after 6 d's culture began to shrink and blacken. Significant increase in survival rate and maturation rate of oocytes was observed in Gn group (P〈0.01), with 92.9% survived and 28.7%formed an antrum. Further supplementation of the Gn medium with ITS and rLH, resulted in the significant increase in survival and maturation of preantral follicle (P〈0.05) Conclusions α-MEM can be the medium for in vitro culture (IVC) of preantral follicles, but need to be added with rLH/rFSH, rHCG/rEGF to facilitate thecal cell attachment, GC proliferation and oocyte maturation.  相似文献   
57.
《Vaccine》2006,24(44-46):6793-6795
Influenza vaccinations and antiviral drugs are the foundation of epidemic and pandemic preparedness, but only close collaboration between public health authorities and industry can achieve the necessary production levels and ensure the smooth distribution necessary to protect European citizens from this public health scourge. To focus the minds of all public health stakeholders, ESWI has translated these simple facts into clear achievable goals: it recommends that EU governments vaccinate one-third of their populations by 2010 and stockpile antiviral drugs for 20% of their citizens while promoting public-private partnerships. The scientific justification behind this objective is easily understood namely that while the annual flu shot protects against three viral strains,the pandemic vaccine will focus on only the one highly lethal virus. As a result if countries succeed in meeting the target to vaccine one-third of the EU-25 population with a trivalent vaccine, sufficient monovalent pandemic vaccine could be produced to vaccinate almost the entire EU-25 population at least once. Achieving these objectives would go far to containing the pandemic and ensuring necessary treatment to avoid needless deaths and social and economic disruption. It would also signal that influenza preparedness had become part of the European mindset. Relying on the technique of force-field analysis organised by professional facilitators the session asked government representatives and policy makers to identify existing factors that either provide support for the objectives or hinder progress.  相似文献   
58.
59.
Six thermophilic extremophiles, Anoxybacillus amylolyticus, Geobacillus thermoleovorans, Geobacillus thermoleovorans subspecies stromboliensis, Geobacillus toebii subspecies decanicus, Bacillus thermantarcticus and Thermus oshimai, isolated from different environmental sites, were studied for their heavy metal resistance. The effects of heavy metals on microorganism growth were studied here in a pilot fermenter tank spiked with various trace metals, (Ni2+, Zn2+, Co2+, Hg2+, Mn2+, Cr6+, Cu2+, Fe3+ and Cd2+) at concentrations spanning from 0.01 to 20 mM. Trace metal toxicity varied depending on the species and metal considered. Among the tested microorganisms, attention was focused on α-amylase producing-A. amylolyticus, an acidothermophilic bacterium recently isolated from geothermal soil samples from Mount Rittmann in Antarctica. The effect of heavy metals on the biosynthesis and activity of α-amylase of A. amylolyticus was investigated. When bacteria were grown in the presence of heavy metals, a decrease in α-amylase activity, correlated with a decrease in α-amylase production, was observed, suggesting an effect on the biosynthesis of the enzyme. A decrease in enzyme activity was also noted when the assay was performed in the presence of heavy metals. Thus, α-amylase could represent a potential sensitive bioassay for detecting trace heavy metals.  相似文献   
60.
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