首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1424篇
  免费   68篇
  国内免费   4篇
耳鼻咽喉   17篇
儿科学   104篇
妇产科学   27篇
基础医学   205篇
口腔科学   28篇
临床医学   150篇
内科学   226篇
皮肤病学   25篇
神经病学   75篇
特种医学   45篇
外国民族医学   1篇
外科学   120篇
综合类   37篇
一般理论   1篇
预防医学   106篇
眼科学   69篇
药学   126篇
中国医学   7篇
肿瘤学   127篇
  2023年   13篇
  2022年   29篇
  2021年   68篇
  2020年   33篇
  2019年   50篇
  2018年   46篇
  2017年   36篇
  2016年   47篇
  2015年   53篇
  2014年   73篇
  2013年   96篇
  2012年   139篇
  2011年   122篇
  2010年   64篇
  2009年   42篇
  2008年   90篇
  2007年   93篇
  2006年   79篇
  2005年   56篇
  2004年   77篇
  2003年   51篇
  2002年   62篇
  2001年   9篇
  2000年   5篇
  1999年   7篇
  1998年   10篇
  1997年   5篇
  1996年   3篇
  1995年   1篇
  1994年   4篇
  1993年   6篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1989年   5篇
  1988年   2篇
  1987年   4篇
  1984年   1篇
  1983年   2篇
  1981年   2篇
  1980年   2篇
  1977年   1篇
  1948年   1篇
  1930年   1篇
  1929年   1篇
  1922年   1篇
排序方式: 共有1496条查询结果,搜索用时 15 毫秒
121.
122.
Pneumonia due to H1N1 infection is now very common. We report a case of ischemic stroke which arose subsequently to H1N1 influenza. The patient was a female who developed acute respiratory distress syndrome (ARDS) after H1N1 influenza, was ventilated as per standard protocol and started treatment with oseltamivir. When sedation was stopped during weaning from the ventilator, she was found to have left hemiparesis resulting from multiple infarctions in the brain. Contrary to thrombocytosis usually seen in acute influenza, the platelet counts in our patient actually dropped. We suspected that increased interleukin release or stickiness of the platelets might have caused this ischemic stroke. In the course of time, she had acceptable neurological recovery following treatment with aspirin and neuro-rehabilitation. This case report provides evidence that a rare, debilitating complication like stroke can occur in H1N1 infection. A high index of suspicion of the probability of a cerebrovascular event should be borne in mind and regular neurological assessment should be done in such cases.  相似文献   
123.
Mitomycin C (MMC) is an antineoplastic agent used to fight a number of different cancers including cancer of the stomach, colon, rectum, pancreas, breast, lung, uterus, cervix, bladder, head, neck, eye and oesophagus. It is a potent DNA cross-linker. The prolonged use of the drug may result in permanent bone marrow damage and other various types of secondary tumors in normal cells. The toxic effect of anticancerous drugs may be reduced if supplemented with natural antioxidants/plant products. With this view, the effect of 5, 10 and 15 μM of curcumin was studied against the genotoxic doses of MMC, i.e. 10 and 20 μM, in cultured human lymphocytes using cell viability, lipid peroxidation and DNA damage quantification as parameters. The treatment of curcumin with MMC results in a significant dose-dependent increase in cell viability and decrease in lipid peroxidation and DNA damage suggesting a protective role of curcumin against the anticancerous drug mitomycin C.  相似文献   
124.
Microglia are implicated in multiple neurodegenerative disorders, many of which display sexual dimorphisms and have symptom onsets at different ages. P2 purinergic receptors are critical for regulating various microglial functions, but little is known about how their expression varies with age or sex. Therefore, comprehensive information about purinergic receptor expression in normal microglia, in both sexes, over age is necessary if we are to better understand their roles in the healthy and diseased CNS. We analyzed the expression of all fourteen rodent P2X and P2Y receptors in CD11b+ cells freshly-isolated from the brains of C57Bl/6 mice at five different ages ranging from postnatal day 3 to 12 months, in males and females, using quantitative RT-PCR. We also compared purinergic receptor expression in microglia freshly-isolated from 3 day-old pups to that in primary neonatal microglial cultures created from mice of the same age. We observed patterns in P2 receptor expression with age, most notably increased expression with age and age-restricted expression. There were also several receptors that showed sexually dimorphic expression. Lastly, we noted that in vitro culturing of neonatal microglia greatly changed their P2 receptor expression profiles. These data represent the first complete and systematic report of changes in purinergic receptor expression of microglia with age and sex, and provide important information necessary for accurate in vitro modeling of healthy animals.  相似文献   
125.
To study the impact of Positron emission tomography (PET) and its incremental value in diagnosing an unknown primary tumour with secondaries in the head and neck; recurrent head and neck cancers (confirmation of suspected recurrences and re-staging); and staging of head and neck tumours. This was a prospective observational study where 60 patients of head and neck tumours under the clinical settings as described above were evaluated. Thorough clinical examination and necessary radiological and histopathological investigations were done. All patients underwent a PET scan, the results of which were correlated with histopathological examination. Sensitivities, specificities, positive and negative predictive values, false positives and false negatives of PET scan in the different indications were calculated. The study included 11 patients of unknown primary, 28 patients with suspected recurrent tumours and 21 patients where PET scan was done for initial staging. PETCT scan was able to detect the primary in 3 out of 11 patients (27.27 %) who presented with cervical metastases with an unknown primary. In 2 of the 8 patients where a primary tumour was not found, PETCT detected distant metastases. For recurrent tumours, PETCT scan showed sensitivity, specificity, positive predictive value and negative predictive value as 100, 72.72, 85 and 100 % respectively. In restaging of recurrent disease, 4 out of 28 patients were detected to have distant metastases. In 7 cases of locoregionally advanced tumors, where PETCT scan was used for pre-treatment staging, it detected distant metastases in 4 of 7 patients. In the patients with N0 neck status PETCT scan showed a sensitivity, specificity, positive predictive value and negative predictive value of 100, 66.67, 50 and 100 % respectively. PETCT scan was able to alter the plan of management in 15 out of 60 patients. Thus, in carefully selected patients PETCT scan can provide incremental information that proves invaluable in these circumstances even in a developing country like India. In all the settings, PETCT scan demonstrated a very high negative predictive value. Hence, negative PETCT scan could be interpreted as absence of disease with reasonable assurance.  相似文献   
126.
Malignant Otitis Externa, though a misnomer, definitely alarms the surgeon, the idea that it behaves and spreads like a malignancy, in elderly diabetics, and if not treated deligently, can be fatal. Though the main line of treatment is medical, surgical intervention should not be deferred if indicated. We are presenting one such case where we have not only saved the patient's life but also controlled the pain adequately.  相似文献   
127.
Cowper’s syringocele is cystic dilatation of the excretory bulbourethral gland duct. It is an uncommon condition and is usually reported in children. There are only ten previous case reports of late presentation in adulthood to the best of our knowledge. We present the imaging findings of such a case manifesting at 30 years of age.  相似文献   
128.
129.
Pulsed, mid-infrared lasers were recently investigated as a method to stimulate neural activity. There are significant benefits of optically stimulating nerves over electrically stimulating, in particular the application of more spatially confined neural stimulation. We report results from experiments in which the gerbil auditory system was stimulated by optical radiation, acoustic tones, or electric current. Immunohistochemical staining for the protein c-FOS revealed the spread of excitation. We demonstrate a spatially selective activation of neurons using a laser; only neurons in the direct optical path are stimulated. This pattern of c-FOS labeling is in contrast to that after electrical stimulation. Electrical stimulation leads to a large, more spatially extended population of labeled, activated neurons. In the auditory system, optical stimulation of nerves could have a significant impact on the performance of cochlear implants, which can be limited by the electric current spread.  相似文献   
130.
A study was conducted to explore the effect of arsenic causing conjunctivitis, neuropathy and respiratory illness in individuals, with or without skin lesions, as a result of exposure through drinking water, contaminated with arsenic to similar extent. Exposed study population belongs to the districts of North 24 Parganas and Nadia, West Bengal, India. A total of 725 exposed (373 with skin lesions and 352 without skin lesions) and 389 unexposed individuals were recruited as study participants. Participants were clinically examined and interviewed. Arsenic content in drinking water, urine, nail and hair was estimated. Individuals with skin lesion showed significant retention of arsenic in nail and hair and lower amount of urinary arsenic compared to the group without any skin lesion. Individuals with skin lesion also showed higher risk for conjunctivitis ((odd's ratio) OR: 7.33, 95% CI: 5.05-10.59), peripheral neuropathy (OR: 3.95, 95% CI: 2.61-5.93) and respiratory illness (OR: 4.86, 95% CI: 3.16-7.48) compared to the group without any skin lesion. The trend test for OR of the three diseases in three groups was found to be statistically significant. Again, individuals without skin lesion in the exposed group showed higher risk for conjunctivitis (OR: 4.66, 95% CI: 2.45-8.85), neuropathy (OR: 3.99, 95% CI: 1.95-8.09), and respiratory illness (OR: 3.21, 95% CI: 1.65-6.26) when compared to arsenic unexposed individuals. Although individuals with skin lesions were more susceptible to arsenic-induced toxicity, individuals without skin lesions were also subclinically affected and are also susceptible to arsenic-induced toxicity and carcinogenicity when compared to individuals not exposed to arsenic.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号