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   1142篇
  免费   102篇
  国内免费   25篇
耳鼻咽喉   32篇
儿科学   79篇
妇产科学   4篇
基础医学   491篇
口腔科学   3篇
临床医学   59篇
内科学   249篇
皮肤病学   65篇
神经病学   6篇
特种医学   2篇
外科学   7篇
综合类   125篇
预防医学   14篇
眼科学   11篇
药学   73篇
中国医学   45篇
肿瘤学   4篇
  2023年   19篇
  2022年   16篇
  2021年   41篇
  2020年   45篇
  2019年   41篇
  2018年   34篇
  2017年   31篇
  2016年   24篇
  2015年   25篇
  2014年   47篇
  2013年   69篇
  2012年   52篇
  2011年   37篇
  2010年   29篇
  2009年   44篇
  2008年   43篇
  2007年   60篇
  2006年   48篇
  2005年   38篇
  2004年   54篇
  2003年   42篇
  2002年   36篇
  2001年   43篇
  2000年   48篇
  1999年   47篇
  1998年   46篇
  1997年   48篇
  1996年   43篇
  1995年   15篇
  1994年   22篇
  1993年   17篇
  1992年   11篇
  1991年   6篇
  1990年   6篇
  1989年   4篇
  1988年   8篇
  1987年   1篇
  1985年   3篇
  1984年   3篇
  1983年   6篇
  1982年   3篇
  1981年   3篇
  1980年   2篇
  1979年   3篇
  1978年   4篇
  1975年   1篇
  1974年   1篇
排序方式: 共有1269条查询结果,搜索用时 31 毫秒
21.
Background Seasonal allergic conjunctivitis (SAC) is the most common allergic disease to affect the eye. occurring alone or in association with allergic rhinitis. Infiltration with mast cells and eosinophils is characteristic of the chronic forms of allergic conjunctivitis such as vernal and atopic keratoconjunctivitis. and these cell types also contribute significantly to allergic inflammation in the skin. Indirect evidence for a similar pattern of cellular events in SAC comes from studies which demonstrate raised eosinophil and neutrophil numbers in conjunctival scrapings and elevated levels of mast cell tryptase in tears following allergen challenge. Objective To directly characterize the inflammatory cell infiltrate in SAC and to determine its clinical relevance. Methods We employed specific immunohistochemical staining to count masi cells, eosinophiis and neutrophiis in the conjunctival epithelium and lamina propria of eight atopic patients with SAC in, and 12 SAC patients out of the hay fever season. Sixteen patients with no history of ocular allergy were used as control subjects. Results Mast cells were absent from normal epithelium. During the pollen season median mast cell numbers in the lamina propria were found to be increased by 6I'J(in patients with SAC compared with normals (P= 0.012). Eosinophils were found in the lamina propria in less than half of the symptomatic patients with SAC and in only three patients were eosinophils present in the epithelium. The neutrophil numbers in the lamina propria of patients with SAC tended to be higher than normals but these changes did not reach statistical significance. Conclusion Conclusion These data based on the direct assessment of conjunctival tissue provide evidence that symptoms occur in SAC in the absence of detectable recruitment of eosinophils or neutrophils. This suggests that this disorder is related to mast cell-mediated changes.  相似文献   
22.
Objective and design: A simple method for preparing mouse eosinophils was established, and the characteristics of the eosinophils were assessed including their responses to anti-allergic drugs. Materials or subjects: Mouse eosinophils were prepared from peritoneal exudate cells of BALB/c mice primed and boosted with antigen ovalbumin (OVA). Methods: Surface phenotypes, migration activities and leukotriene C4 (LTC4) production abilities of these eosinophils were examined. In addition, the effects of anti-allergic drugs, oxatomide and tranilast, on generation of LTC4 from mouse eosinophils were examined. Results: Eosinophils of mice boosted with OVA were phenotypically and functionally identical with human eosinophils. Around 1 × 107 eosinophils were obtained from mouse peritoneal exudate. It was found that these mouse eosinophils enabled to migrate in response to eotaxin as well as platelet-activating factor (PAF), and generated LTC4 by IL-5 stimulation. Moreover, it was revealed that clinically used anti-allergic drugs inhibited LTC4-production dose-dependently. Conclusions: The present study provides a convenient method to obtain fully functional mouse eosinophils that are useful for drug screening and for evaluating implications of eosinophils in allergic responses. Received 20 April 2006; returned for revision 6 July 2006; returned for final revision 29 August 2006; accepted by M. Katori 29 September 2006  相似文献   
23.
24.
目的:探讨嗜酸性粒细胞在鼻息肉发病机理中的意义。方法:用增殖细胞核抗原(PCNA)免疫组化方法对鼻息肉组织76例和正常鼻腔粘膜组织32例进行定量测定,同时对鼻息肉组织中嗜酸性粒细胞定量计数。结果:(1)鼻息肉上皮组织中PCNA阳性细胞表达数明显高于正常鼻腔粘膜(P<0.001),(2)嗜酸性粒细胞浸润程度与鼻息肉上皮细胞增殖相关(P<0.05)。结论:上皮细胞增殖活跃在鼻息肉发病机理中占重要地位,而嗜酸性粒细胞的多少与其上皮细胞增殖相关,说明嗜酸性粒细胞与鼻息肉发病过程有直接相关性。  相似文献   
25.
Currently, the clinical factors affecting immune responses to influenza vaccines have not been systematically explored. The mechanism of low responsiveness to influenza vaccination (LRIV) is complicated and not thoroughly elucidated. Thus, we integrate our in-house genome-wide association studies (GWAS) analysis result of LRIV (N = 111, Ncase [Low Responders] = 34, Ncontrol [Responders] = 77) with the GWAS summary of 10 blood-based biomarkers (sample size ranging from 62 076−108 794) deposited in BioBank Japan (BBJ) to comprehensively explore the shared genetics between LRIV and blood-based biomarkers to investigate the causal relationships between blood-based biomarkers and LRIV by Mendelian randomization (MR). The applications of four MR approaches (inverse-variance-weighted [IVW], weighted median, weighted mode, and generalized summary-data-based MR [GSMR]) suggested that the genetically instrumented LRIV was associated with decreased eosinophil count (β = −5.517 to −4.422, p = 0.004−0.039). Finally, we conclude that the low level of eosinophil count is a suggestive risk factor for LRIV.  相似文献   
26.
There is currently interest in the potential use of selective inhibitors of cyclic nucleotide phosphodiesterases (PDE) in the treatment of asthma. In this study we examined the effects of three selective PDE inhibitors, milrinone (PDE III), rolipram (PDE IV) and zaprinast (PDE V), on the broncoconstriction produced by antigen and histamine, the airway hyperreactivity and microvascular leakage after aerosol exposure to platelet-activating factor (PAF) and antigen, and the antigen-induced eosinophil infiltration in guinea-pig lung. Inhaled rolipram (0.01–10 mg ml–1) inhibited dose dependently the bronchospasm produced by aerosol antigen (5 mg ml–1) an anaesthetised, ventilated guinea-pigs. Rolipram (10 mg ml–1) produced maximal inhibition of antigen-induced bronchoconstriction but only partial inhibition of the response to aerosol histamine (1 mg ml–1). Milrinone and zaprinast (each 10 mg ml–1) showed weak, or no, inhibitory effects against bronchoconstriction produced by aerosol antigen or histamine. Pretreatment with rolipram (10 mg kg–1, i.p.) prevented airway hyperreactivity to histamine which develops 24 h after exposure of conscious guinea-pigs to aerosol PAF (500 g ml–1) or antigen (5 mg ml–1). The pulmonary eosinophil infiltration obtained with 24 h of antigen-exposure was inhibited by rolipram. In contrast, milrinone and zaprinast (each 10 mg kg–1, i.p.) failed to reduce either the airway hyperreactivity of the eosinophil accumulation in these animals. Rolipram (1–10 mg ml–1) reduced the extravasation of Evans blue after aerosol PAF (500 g ml–1) at all airway levels while a lower dose (0.1 mg ml–1) was only effective at intrapulmonary airways. Rolipram (0.01–1 mg ml–1) markedly reduced airway extravasation produced by inhaled antigen (5 mg ml–1). Zaprinast (1–10 mg ml–1) was also effective against airway microvascular leakage produced by aerosol PAF or antigen while milrinone (10 mg ml–1) had no antiexudative effect. These data support previous suggestions that pharmacological inhibition of PDE IV results in anti-spasmogenic and anti-inflammatory effects in the airways and may be useful in the treatment of asthma.  相似文献   
27.
Biochemical evaluation of inflammation may be a useful adjunct to measures of pulmonary function and symptoms in children with asthma. However, little data have been provided to validate the markers in children. The aim of the present study was to assess circadian variations in serum eosinophil cationic protein (ECP), and serum and urine eosinophil protein X (EPX) in children. Five girls and two boys aged 10–14 years were studied. The first sample of urine consisted of urine collected from 24.00 hours the night before until 08.00 hours on the morning of the day of investigation. Thereafter urine was collected at 4-h intervals until 24.00 hours and in another 8-h interval from 24.00 to 08.00 hours. Blood samples for assessment of serum ECP and serum EPX were collected every 2 h during the 24 h. Statistically significant circadian variations in serum ECP (F=3.2, p=0.002), serum EPX (F=3.1, p=0.002) and in urine EPX/creatinine (F=5.4, p=0.003) were detected. The concentrations were higher during the night compared to daytime. Peak levels of serum ECP (mean [± SEM]) were found at 06.00 hours (16.3 [5.3] µg/l), trough levels at 08.00 hours (3.9 [0.7] µg/l) (p=0.01). Peak levels of serum EPX were seen at 06.00 (43.7 [9.5] µg/l) with trough levels at 12.00 hours (22.0 [3.5] µg/l) (p=0.01). Peak levels of urine EPX/creatinine occurred in urine collected from 24.00 to 08.00 hours (90.0 [27.7] µg/mmol), trough levels in the 16.00–20.00 hours sample (29.7 [8.9] µg/mmol) (p=0.02). Serum ECP, serum EPX and urine EPX exhibit a circadian variation in children with nocturnal and early morning peak levels. To avoid confounding influence from circadian variations in ECP and EPX in clinical studies blood or urine should be sampled at consistent times.  相似文献   
28.
The role of serum eosinophil cationic protein levels in allergic rhinitis is controversial. It is also unclear whether with immunotherapy it is possible to reduce these serum levels in allergic diseases. We studied serum eosinophil cationic protein levels in patients with cedar-induced allergic rhinitis and compared them with non-atopic controls. The second aim of this study was to elucidate whether immunotherapy is capable of decreasing the seasonal elevation in serum eosinophil cationic protein levels in seasonal allergic rhinitis. The serum eosinophil cationic protein levels of the untreated patient group were significantly higher than those of the non-atopic controls. The levels in patients who received immunotherapy for 2 yr were also significantly higher than those of the non-atopic controls. However, the levels were not different between the patients undergoing immunotherapy for over 3 yr and the non-atopic controls. The serum levels of the 31 patients treated with immunotherapy correlated with the duration of immunotherapy. In conclusion, the serum eosinophil cationic protein levels are higher in untreated patients with seasonal allergic rhinitis and this seasonal activation in circulating eosinophils decreases gradually during immunotherapy, but this inhibitory effect becomes apparent only after a number of years of immunotherapy. This prevention of seasonal eosinophil activation is one of the mechanisms responsible for the clinical effect of immunotherapy.  相似文献   
29.
六君子汤加黄芪增强肝癌化疗栓塞术后患者细胞免疫功能和疗效观察程惠华,郑立昇,陈樟树,涂小煌,吴昌信,王雯,戴西湖近年来,肝动脉化疗栓塞术(TranscatheterArterialChemoembolization,TACE)已成为非手术治疗肝癌,特...  相似文献   
30.
This study evaluated the outcome of 33 children with asthma-like symptoms without objective evidence of asthma, and the role of certain factors in predicting the development of clinical asthma in these children. Data on symptom histories, lung functions (flow-volume spirometry, free running test and methacholine inhalation challenge test) and atopic sensitization (skin prick tests and markers of eosinophilic inflammation) were collected twice with an interval of 2 y, and the diagnoses were re-evaluated after the follow-up period. Based on the results, it was concluded that one-third of the children with prolonged or recurrent lower airway symptoms, such as cough or wheeze, either have mild asthma or will develop asthma in the near future. Children who had a significant response [≥ 10% fall in forced expiratory volume in 1 s (FEV1)] in the free running test formed a risk group for active asthma, whereas other baseline characteristics seemed not to predict the outcome.  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