全文获取类型
收费全文 | 20731篇 |
免费 | 1808篇 |
国内免费 | 466篇 |
专业分类
耳鼻咽喉 | 124篇 |
儿科学 | 1761篇 |
妇产科学 | 54篇 |
基础医学 | 5145篇 |
口腔科学 | 24篇 |
临床医学 | 1439篇 |
内科学 | 4773篇 |
皮肤病学 | 67篇 |
神经病学 | 46篇 |
特种医学 | 401篇 |
外科学 | 307篇 |
综合类 | 3457篇 |
现状与发展 | 3篇 |
预防医学 | 1397篇 |
眼科学 | 6篇 |
药学 | 2347篇 |
22篇 | |
中国医学 | 1490篇 |
肿瘤学 | 142篇 |
出版年
2024年 | 29篇 |
2023年 | 188篇 |
2022年 | 298篇 |
2021年 | 734篇 |
2020年 | 712篇 |
2019年 | 671篇 |
2018年 | 634篇 |
2017年 | 731篇 |
2016年 | 814篇 |
2015年 | 811篇 |
2014年 | 1272篇 |
2013年 | 2414篇 |
2012年 | 1249篇 |
2011年 | 1301篇 |
2010年 | 967篇 |
2009年 | 953篇 |
2008年 | 952篇 |
2007年 | 1112篇 |
2006年 | 1023篇 |
2005年 | 825篇 |
2004年 | 699篇 |
2003年 | 619篇 |
2002年 | 547篇 |
2001年 | 498篇 |
2000年 | 399篇 |
1999年 | 395篇 |
1998年 | 316篇 |
1997年 | 313篇 |
1996年 | 226篇 |
1995年 | 161篇 |
1994年 | 162篇 |
1993年 | 111篇 |
1992年 | 110篇 |
1991年 | 95篇 |
1990年 | 107篇 |
1989年 | 70篇 |
1988年 | 66篇 |
1987年 | 55篇 |
1986年 | 67篇 |
1985年 | 72篇 |
1984年 | 36篇 |
1983年 | 34篇 |
1982年 | 33篇 |
1981年 | 29篇 |
1980年 | 33篇 |
1979年 | 19篇 |
1978年 | 14篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
141.
BACKGROUND: Asthma affects males and females differently. Females have a higher incidence than males after the onset of puberty. This suggests a hormonal component to the development of the disease. Progesterone, a female hormone, has previously been shown to illicit a T-helper type 2 (TH2) immune response similar to that seen in allergic asthma. Previous studies performed by our laboratory have shown that exposure to environmental tobacco smoke (ETS) enhances the immune response to allergens. OBJECTIVE: To determine if the combination of exposure to ETS and progesterone would further exacerbate the immune response in a mouse model of allergic asthma. METHODS: Female mice were ovariectomized and then implanted with time-release progesterone pellets. Mice were housed in either filtered air (FA) or ETS chambers and half were exposed to aerosolized house dust mite allergen (HDMA). Bronchoalveolar lavage was performed for cell differentials; lung and spleen cells were harvested to compare IL-4 and IFN-gamma production by ELISPOT. RESULTS: Progesterone pellet implantation resulted in increased serum progesterone levels (28.3+/-8.43 vs. 13.5+/-7.22 ng/mL in placebo-treated mice, P<0.0001). Serum total IgE levels were significantly greater in progesterone vs. non-progesterone treated animals that were also exposed to HDMA. ETS exposure enhanced total IgE levels as well. Lung homogenate cells from HDMA/progesterone-treated animals stimulated with Concavalin A produced significantly more IL-4 compared with HDMA/placebo-treated animals (200+/-17.6 vs. 146+/-17.5 spots/well, P<0.01 in ETS exposed animals and 221+/-28.9 vs. 167+/-23.4 spots/well, P<0.01 in animals housed in FA). HDMA/ETS-treated animals had higher eosinophilia in lavage than all other groups. CONCLUSION: Increased serum progesterone levels exacerbate the allergic asthmatic phenotype in a mouse model. These effects are further exacerbated by the addition of environmental tobacco smoke. Progesterone provides a major contribution to the gender differences seen in the development and elicitation of the asthmatic response. 相似文献
142.
护理干预对哮喘患者疾病认知水平及肺功能的影响 总被引:1,自引:0,他引:1
目的评价护理干预对哮喘患者疾病认知水平和肺功能的影响。方法对中、重度哮喘住院患者78例进行针对性的护理干预,采用自行设计的哮喘疾病知识调查问卷,评估患者护理干预及综合治疗前后对哮喘基础理论知识、行为技巧的掌握情况和肺功能的改善状况。结果护理干预后,哮喘患者对各项疾病知识的掌握水平有明显提高(P〈0.05);经过综合治疗及护理干预,患者的肺功能也得到明显改善(P〈0.05)。结论护理干预不仅能促进哮喘患者对疾病理论知识和自我行为监控技巧的掌握,而且对患者肺功能的改善也有明显效果。 相似文献
143.
儿童慢性轻度哮喘治疗的临床研究 总被引:1,自引:0,他引:1
目的 探讨 3~ 8岁儿童慢性轻度哮喘的早期干预治疗方法。方法 将 12 0例 3~ 8岁慢性轻度哮喘患儿随机均分为治疗组 1、2和对照组。治疗组 1:3~ 5岁患儿口服孟鲁司特 (顺尔宁 ) 4 .0mg/d ,5~ 8岁服5 .0mg/d ,疗程 3~ 6个月 ;治疗组 2 :予口服盐酸西替利嗪 2 .5~ 5 .0mg/d ,疗程 3~ 6个月 ;对照组 :口服安慰剂。均于每日睡前服用。结果 与治疗组 2及对照组相比 ,治疗组 1的日间及夜间症状出现率、急性加重发生率、月均 β 受体激动剂使用率、峰值呼气流速 (PEF)变化、嗜酸性粒细胞计数 (EC)下降率的差异有显著性 (P <0 .0 1) ,而住院率、药物不良反应率的差异无显著性 (P >0 .0 5 )。治疗组 2与对照组EC值的差异有显著性 (P <0 .0 1) ,其余指标的差异均无显著性 (P值均 >0 .0 5 )。结论 白三烯受体拮抗剂孟鲁司特单独用于慢性轻型哮喘儿童的早期干预治疗具有疗效好、不良反应小及患儿依从性高的特点 相似文献
144.
平喘合剂治疗小儿哮喘发作期的临床研究 总被引:2,自引:0,他引:2
马婷 《山东中医药大学学报》2004,28(2):121-125
认为哮喘是外因作用于内因的结果 ,痰瘀伏肺为其宿根 ,外邪引触伏痰、痰瘀胶结、阻塞气道、痰阻气逆为其病机 ,寒热夹杂为其病性。具有宣肺化痰、降气平喘、清热活血功效的中药平喘合剂可明显改善哮喘发作期患儿的肺通气功能 ,明显降低患儿血浆中sICAM 1、IgE水平 ,与对照组比较有显著性差异 (P <0 .0 1,P <0 .0 5 ) ,推测其作用机制可能与减轻气道阻塞、调节免疫反应及抑制气道炎症等多个环节有关 相似文献
145.
Immunotherapy vs inhaled budesonide in bronchial asthma: an open, parallel, comparative trial 总被引:1,自引:0,他引:1
W. A. SHAIKH 《Clinical and experimental allergy》1997,27(11):1279-1284
Background Budesonide, an inhaled corticosteroid and specific immunotherapy, are both routinely used in the treatment of bronchial asthma. However, there are as yet, no studies comparing the effects of budesonide vs immunotherapy. Objective The aim of this study is to compare the effects of budesonide with immunotherapy in patients having perennial asthma. Methods This study is an open, parallel, comparative trial, in which 51 young patients were administered either immunotherapy or budesonide for 1 year and their global symptom scores and FEV1, values assessed. Both treatments were abruptly discontinued after 12 months and the effects of cessation analysed. Results The use of budesonide resulted in a faster and more striking improvement during the first few months as compared to immunotherapy, with an even more rapid decline in benefits on cessation of budesonide. Immunotherapy on the other hand, resulted in slow but steady improvement which did not decline as rapidly as budesonide on cessation. Conclusion Although this was an open trial, it could be concluded that relief with inhaled corticosteroids in bronchial asthma is more rapid than immunotherapy; however the decline in benefit on cessation of inhaled cortieosteroid is even more rapid, a phenomenon not seen with immunotherapy. 相似文献
146.
147.
L. M. TERAN M. G. CAMPOS B. T. BEGISHVILLI J.-M. SCHRÖDER R. DJUKANOVIC J. K. SHUTE M. K. CHURCH S. T. HOLGATE D. E. DAVIES† 《Clinical and experimental allergy》1997,27(4):396-405
Background Although neutrophils have been implicated in bronchial asthma, the mechanism(s) which bring these cells into the airways is poorly understood. Objective To investigate the presence and identity of neutrophil chemotactic factors in bronchoalveolar lavage (BAL) fluid from atopic asthmatic subjects. Method BAL fluid was obtained from 13 subjects (seven asthmatics and six normals). aged 19 to 60 yr, at bronchoscopy. Separation of neutrophil chemotactic activity (NCA) was achieved by FPLC cation exchange chromatography. Fractions were collected and assayed for chemotaxis multiwell micro-chemotaxes chambers using polycarbonate filters, for the complement peptide C5a/C5a des Arg by radioimmunoassay (RIA) and for interleukin-8 (IL-8) by ELISA. Results NCA was found in FPLC fractions of BAL samples in four out of seven asthmatics and each of these subjects had at least three similar peaks of NCA. The major peak of NCA was found to contain immunoreactive C5a/C5a des Arg and chemotaxis. In response to this NCA could be blocked by desensitization of the neutrophils with recombinant C5a. Purified serum derived C5a/C5a des Arg was found to have altered chromatographic properties when added to BAL fluid; this suggested that BAL fluid contained proteins which interacted with the C5a/C5a des Arg. Immunoreactive IL-8 (iIL-8) was also detected but its concentration or chemical form was insufficient to induce neutropbil chemotaxis. Conclusion This study demonstrates that bronchial asthmatic lavage fluid contains C5a/C5a des/Arg and iL-8, together with other as yet unidentified factors which may contribute to neutropbil recruitment in this disease. 相似文献
148.
M. M. Moens A. V. Mertens L. S. De Clerck H. P. Van Bever C. H. Bridts W. J. Stevens 《Pediatric allergy and immunology》1993,4(2):89-92
In patients with allergic asthma and rhinitis high numbers of hypodense eosinophils (HE) have been demonstrated. In a previous study we reported that asthmatic and healthy children had more HE than their adult counterparts. We assumed that this might, in part, he due to the presence of immature eosinophils in children. To distinguish between immature and activated eosinophils, determination of eosinophil cationic protein (ECP) might be interesting as it is known that high serum levels of ECP are associated with increased activation of eosinophiis. In this study we determined (he levels of ECP in scrum in asthmatic and healthy children and adults trying to distinguish activated from immature eosinophils. We found that ECP levels were not increased in children (healthy and asthmatic) compared to adults (healthy and asthmatic). This supports the hypothesis that increased numbers of HE in childhood are, at least in part, immature eosinophils. Nevertheless, we could confirm that inflammation was present in children because soluble interleukin-2-receptor (slL-2R), a marker of lymphocyte activation, was higher in asthmatic children as compared to healthy children. IL-6, a marker of macrophage/monocyte activation, was not different in the different patient groups. We conclude that although signs of inflammation are present in childhood asthma, the increased numbers of HE in children are in part due to the presence of immature eosinophils. 相似文献
149.
目的:探讨哮喘吸入二丙酸倍氯米松治疗哮喘时血糖和相关激素的改变及其,方法:将研究对象分成四组:正常对照组、哮喘组、短期吸入(二丙酸倍氯米松)、组和长期吸入(二丙酸倍氯米松)组,应用放射免疫法分别测定上述四组儿童的胰岛不,胰高血糖素水平,氧化法测定血糖水平并做糖耐量实验。结果:四组儿童的胰岛素、胰高血糖素和血糖之间差异无显性意义;糖耐量试验也证明,在哮喘和吸入二丙酸倍氯米松治疗的情况下血糖水平差异无显性。结论:轻中度哮喘患糖代谢基本正常,吸入小剂量糖皮质素不会引起机体糖代谢紊乱。 相似文献
150.
Th. Junginger S. Walgenbach H. Pichlmaier 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1989,374(6):323-328
Zusammenfassung Experimentelle Untersuchungen haben für den maschinellen Bronchusverschluß nach Lobektomie und Pneumonektomie im Vergleich zu anderen Nahtmaterialien die geringste Entzündungsrate und die höchste Zugfestigkeit ergeben. In einer konsekutiven Serie von 233 Lungenresektionen der Chirurgischen Kliniken Köln-Lindenthal und der Klinik für Allgemein- und Abdominalchirurgie der Johannes Gutenberg-Universität Mainz ging die Häufigkeit einer Bronchus-stumpfinsuffizienz von 7,1% nach manuellem Bronchusverschluß auf 2,0% und die insuffizienzbedingte Letalität auf 0,7% bei Anwendung des Klammergeräts zurück. Die wesentlichen Vorteile des maschinellen Bronchusverschlusses sind die Einfachheit der Anwendung, die Schnelligkeit und die Gleichmäßigkeit des Verschlusses. Damit stellen die Klammernahtgeräte bei Lungenresektionen eine wertvolle Ergänzung der Operationstechnik dar.
Mechanical and manual bronchial closure —results of a consecutive trial
Summary After lobectomy and pneumonectomy in experimental evaluations stapled bronchial closures showed the lowest incidence of inflammatory reaction and the highest strength determined by leakage pressure compared with other suture material. A total of 233 lung resections - performed at Surgical University Clinic Köln-Lindenthal and the Clinic for General and Abdominal Surgery of the Johannes-Gutenberg-Universität Mainz — were reviewed. Mechanical stapling reduced the rate of bronchopleural fistulas to 2.0% compared with 7.1 % after manual suturing. In parallel, mortality related to bronchial stump leakage decreased to 0.7%. Main advantages of bronchial closure with staplers are the simplicity of their use, the speed and the uniformity of the closure. Thereby stapling devices are valuable completions in pulmonary surgery.相似文献