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131.
132.
Cellobiase from Termitomyces clypeatus: activity and secretion in presence of glycosylation inhibitors 总被引:2,自引:0,他引:2
In presence of the glycosylation inhibitors, 2-deoxy-d-glucose (1 mg/ml), tunicamycin (30 μg/ml), 1-deoxynojirimycin (30 μg/ml) and d-glucono-δ-lactone (1 mg/ml), total cellobiase activity, in the extracellular, intracellular and cell bound fractions, of the fungus Termitomyces clypeatus grown in 20 ml cellobiose medium (1%, w/v) increased by 50-, 1.8-, 2.4-, 1.3-fold, respectively, with respect to control medium (16.3 U). The inhibitors also stimulated secretion of 95% of the total protein in culture medium, except d-glucono-δ-lactone which released 60% of the total protein. 2-Deoxy-d-glucose (1 mg/ml) led to production of extracellular cellobiase up to 40 U/ml, whereas in absence of the inhibitors only 0.59 U/ml enzyme was detected. 相似文献
133.
Kar A Saha D Purohit G Singh A Kumar P Yadav VK Kumar P Thakur RK Chowdhury S 《Nucleic acids research》2012,40(6):2554-2565
Analysis of chromatin-immunoprecipitation followed by sequencing (ChIP-seq) usually disregards sequence reads that do not map within binding positions (peaks). Using an unbiased approach, we analysed all reads, both that mapped and ones that were not included as part of peaks. ChIP-seq experiments were performed in human lung adenocarcinoma and fibrosarcoma cells for the metastasis suppressor non-metastatic 2 (NME2). Surprisingly, we identified sequence reads that uniquely represented human telomere ends in both cases. In vivo presence of NME2 at telomere ends was validated using independent methods and as further evidence we found intranuclear association of NME2 and the telomere repeat binding factor 2. Most remarkably, results demonstrate that NME2 associates with telomerase and reduces telomerase activity in vitro and in vivo, and sustained NME2 expression resulted in reduced telomere length in aggressive human cancer cells. Anti-metastatic function of NME2 has been demonstrated in human cancers, however, mechanisms are poorly understood. Together, findings reported here suggest a novel role for NME2 as a telomere binding protein that can alter telomerase function and telomere length. This presents an opportunity to investigate telomere-related interactions in metastasis suppression. 相似文献
134.
135.
Hepatitis C Virus Infection Modulates Expression of Interferon Stimulatory Gene IFITM1 by Upregulating miR-130A 总被引:1,自引:0,他引:1
J Bhanja Chowdhury S Shrivastava R Steele AM Di Bisceglie R Ray RB Ray 《Journal of virology》2012,86(18):10221-10225
We have examined the underlying mechanism of hepatitis C virus (HCV)-mediated IFITM1 regulation. IFITM1 is a potential target of miR-130a. Our results demonstrated that miR-130a expression was significantly higher in HCV-infected hepatocytes and liver biopsy specimens than in controls. Introduction of anti-miR-130a in hepatocytes increased IFITM1 expression. Hepatocytes stably expressing IFITM1 reduced HCV replication. Together, these results suggested that HCV infection of hepatocytes upregulates miR-130a and that use of anti-miR-130a may have potential for restriction of HCV replication. 相似文献
136.
Chowdhury MM Dosche C Löhmannsröben HG Leimkühler S 《The Journal of biological chemistry》2012,287(21):17297-17307
We studied two pathways that involve the transfer of persulfide sulfur in humans, molybdenum cofactor biosynthesis and tRNA thiolation. Investigations using human cells showed that the two-domain protein MOCS3 is shared between both pathways. MOCS3 has an N-terminal adenylation domain and a C-terminal rhodanese-like domain. We showed that MOCS3 activates both MOCS2A and URM1 by adenylation and a subsequent sulfur transfer step for the formation of the thiocarboxylate group at the C terminus of each protein. MOCS2A and URM1 are β-grasp fold proteins that contain a highly conserved C-terminal double glycine motif. The role of the terminal glycine of MOCS2A and URM1 was examined for the interaction and the cellular localization with MOCS3. Deletion of the C-terminal glycine of either MOCS2A or URM1 resulted in a loss of interaction with MOCS3. Enhanced cyan fluorescent protein and enhanced yellow fluorescent protein fusions of the proteins were constructed, and the fluorescence resonance energy transfer efficiency was determined by the decrease in the donor lifetime. The cellular localization results showed that extension of the C terminus with an additional glycine of MOCS2A and URM1 altered the localization of MOCS3 from the cytosol to the nucleus. 相似文献
137.
Chowdhury N Dasgupta S Pradeep Singh ND 《Bioorganic & medicinal chemistry letters》2012,22(14):4668-4671
Two different series of naphthalene and anthracene based hydroxamic acids having amino acid derivatives were synthesized. Single strand DNA cleavage was achieved on irradiation of newly synthesized hydroxamic acids by UV light (≥350nm). Both reactive oxygen species (ROS) and generated radicals from hydroxamic acids were shown to be responsible for the DNA cleavage. Further, DNA cleaving ability of hydroxamic acids was found to be dependent on its concentration and on its structure. 相似文献
138.
139.
DB Haque DK Rahman DA Hoque DA Hasan DR Chowdhury DS Khan DM Alam PM Habib PQ Mohammad 《BMC neurology》2012,12(1):82
ABSTRACT: BACKGROUND: To determine the differences of precipitating and relieving factors between migraine and tension type headache METHODS: This is a cross sectional study. We retrospectively reviewed the records of 250 migraine patients and 250 patients diagnosed as tension type headache from the specialized headache clinic in Dept. of Neurology, Dhaka Medical College Hospital. Data were collected through a predesigned questionnaire containing information on age, sex, social status and a predetermined list of precipitating and relieving factors. RESULTS: In this study, the female patients predominated (67%). Most of the patients were within 21--30 years age group (58.6%). About 58% of them belonged to middle class families. The common precipitating factors like stress, anxiety, activity, journey, reading, cold and warm were well distributed among both the migraine and tension type headache (TTH) patients. But significant difference was demonstrated for fatigue (p < 0.05), sleep deprivation (p < 0.05), sunlight (p < 0.01) and food (p < 0.05), which were common among migraineurs. In consideration of relieving factors of pain, different maneuvers were commonly tried by migraineurs and significant difference were observed for both analgesic drug and massage (p < 0.05), which relieved migraine headache. But maneuvers like sleep, rest and posture were used by both groups. CONCLUSION: The most frequent precipitating factors for headache appear to be identical for both migraine and TTH patients. Even though some factors like fatigue, sleep deprivation, sunlight and food significantly precipitate migraine and drug, massage are effective maneuver for relieving pain among migrianeurs. 相似文献
140.
Shakhawat Chowdhury 《人类与生态风险评估》2012,18(5):1051-1068
Dermal exposure to volatile compounds (VC) in municipal water while showering is typically estimated using a steady-state condition between VC in water impacting on skin and skin exposed to water. The lag times to achieve steady-state between VC and skin can vary in the range of 7.5–218.3 min, while shower duration is often less than these values. Estimates of dermal exposure to VC using steady-state while showering may misinterpret exposure. This study developed models and estimated exposure to some disinfection byproducts (DBPs) through dermal pathway by considering lag times while showering. Dermal uptakes of VC were compared using different approaches. In the proposed approach, uptakes of trihalomethanes were estimated between 9.55 × 10?10–1.43 × 10?8 mg/cm2 of skin during the lag times from exposure to water with trihalomethanes of 50 μg/L. These values were higher than the steady-state estimates (1.37 × 10?10–4.34 × 10?9 mg/cm2), and lower than the average exposure analysis (4.12 × 10-8–1.93 × 10?6 mg/cm2). Using the Drinking Water Surveillance Program data in Ontario, chronic daily intakes of trihalomethanes were estimated to be 9.40 × 10?7 (1.85 × 10?7–1.65 × 10?6), 3.89 × 10?6 (7.11 × 10?7–2.33 × 10?5), and 1.40 × 10?6 (4.0 × 10?7–1.77 × 10?6) mg/kg/day in Toronto, Ottawa, and Hamilton, respectively. The findings can be useful in understanding THMs exposure and risk through dermal pathway. 相似文献