全文获取类型
收费全文 | 62159篇 |
免费 | 6834篇 |
国内免费 | 1927篇 |
专业分类
耳鼻咽喉 | 148篇 |
儿科学 | 1775篇 |
妇产科学 | 264篇 |
基础医学 | 4841篇 |
口腔科学 | 121篇 |
临床医学 | 7482篇 |
内科学 | 9489篇 |
皮肤病学 | 147篇 |
神经病学 | 370篇 |
特种医学 | 2401篇 |
外国民族医学 | 98篇 |
外科学 | 5281篇 |
综合类 | 12397篇 |
现状与发展 | 10篇 |
预防医学 | 2963篇 |
眼科学 | 50篇 |
药学 | 5528篇 |
55篇 | |
中国医学 | 2972篇 |
肿瘤学 | 14528篇 |
出版年
2024年 | 508篇 |
2023年 | 1221篇 |
2022年 | 2349篇 |
2021年 | 3187篇 |
2020年 | 2848篇 |
2019年 | 2278篇 |
2018年 | 2149篇 |
2017年 | 2621篇 |
2016年 | 2885篇 |
2015年 | 2924篇 |
2014年 | 4370篇 |
2013年 | 4221篇 |
2012年 | 3921篇 |
2011年 | 4206篇 |
2010年 | 3306篇 |
2009年 | 3046篇 |
2008年 | 2934篇 |
2007年 | 3206篇 |
2006年 | 2823篇 |
2005年 | 2513篇 |
2004年 | 1983篇 |
2003年 | 1627篇 |
2002年 | 1293篇 |
2001年 | 1169篇 |
2000年 | 954篇 |
1999年 | 747篇 |
1998年 | 644篇 |
1997年 | 655篇 |
1996年 | 570篇 |
1995年 | 459篇 |
1994年 | 424篇 |
1993年 | 330篇 |
1992年 | 366篇 |
1991年 | 297篇 |
1990年 | 282篇 |
1989年 | 237篇 |
1988年 | 211篇 |
1987年 | 194篇 |
1986年 | 159篇 |
1985年 | 138篇 |
1984年 | 123篇 |
1983年 | 86篇 |
1982年 | 99篇 |
1981年 | 70篇 |
1980年 | 81篇 |
1979年 | 57篇 |
1978年 | 41篇 |
1977年 | 32篇 |
1976年 | 16篇 |
1975年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
121.
黄建安 《苏州大学学报(自然科学版)》1999,19(6):653
应用小潮气量通气致容许性高碳酸血症方法对11例急性呼吸窘迫综合征(ARDS)进行临床观察。设定潮气量为6.4±1.1ml/kg,保持动脉血二氧化碳(PaCQ2)为5.97±1.41kPa,血氧分压8.54±3.19kPa。结果7例存活,未发现气压伤。说明小潮气量通气致一定程度高碳酸血症是临床上值得推荐使用的方法。 相似文献
122.
BACKGROUND: Nitric oxide [NOexp] is present in exhaled air in many species. During experiments on pressure-controlled inverse ratio ventilation (PCIRV) in rabbits, increased [NOexp] was observed during PCIRV. The present study was undertaken to clarify which component of PCIRV increased [NOexp]. METHODS: Three groups of six New Zealand White rabbits were anaesthetised and mechanically ventilated. Exhaled nitric oxide, lung mechanics and gas exchange were measured using an experimental protocol designed to assess the effects of variations in 1) flow profile, 2) inspiratory time and 3) time-weighted tidal volume. Ventilator settings used were volume and pressure control ventilation at I:E ratios of 1:2 and 4:1. RESULTS: Constant and decelerating flow gave comparable [NOexp] levels (20.0 +/- 6.4 vs. 21.9 +/- 7.7 ppb, n.s.) when time-weighted tidal volume was kept constant. Using conventional (I:E 1:2) or inverted (I:E 4:1) I:E ratios in combination with decelerating flow and constant time-weighted tidal volumes did not alter [NOexp] (26.0 +/- 3.6 vs. 24.0 +/- 5.8 ppb, n.s.). An increased time-weighted tidal volume produced by pressure control with an I:E ratio of 4:1 increased [NOexp] (29.6 +/- 7.4) in comparison to constant (19.3 +/- 4.1, P < 0.05) and decelerating flow ventilation (19.6 +/- 3.6, P < 0.05) with I:E ratios of 1:2. CONCLUSION: The exhaled NO concentration was affected by ventilator setting. Increased levels of [NOexp] were observed with increases in time-weighted tidal volume, whereas changes in flow pattern and inspiratory time did not seem to influence airway NO production or release. 相似文献
123.
Mair P Hoermann C Mair J Margreiter J Puschendorf B Balogh D 《Acta anaesthesiologica Scandinavica》1999,43(4):452-457
BACKGROUND: Proteolytic enzymes and oxygen free radicals released from activated leucocytes contribute significantly to the organ dysfunction associated with cardiopulmonary bypass. Leucocyte depletion during extracorporeal circulation should reduce the release of these toxic compounds and thereby improve postbypass myocardial and pulmonary function. Recently, a leucocyte-specific arterial line filter to achieve leucocyte depletion during clinical perfusion has become commercially available. The aim of this study, therefore, was to evaluate the influence of the leucocyte depleting arterial line filter on proteolytic enzyme release, oxygen free radical release and postbypass pulmonary and myocardial function in patients undergoing bypass surgery. METHODS: Forty patients undergoing elective aortocoronary bypass surgery were included into this prospective, randomized clinical study, 20 in the leucocyte depletion (LG-6 group, leucocyte-specific arterial line filter) and 20 in the control group (AV-6 group, standard arterial line filter). White cell count, differential white cell count, plasma elastase concentration, plasma malondialdehyde concentration and C-reactive protein were determined before, twice during and immediately after cardiopulmonary bypass, at the end of surgery and 6 and 20 h thereafter. RESULTS: White cell count, differential white cell count, malondialdehyde and C-reactive protein were not significantly different between LG-6 and control patients. Plasma elastase concentrations were significantly (P < or = 0.03) higher during and immediately after extracorporeal circulation in LG-6 group patients. Need for inotropic support, arterial pO2 after extracorporeal circulation and perioperative CK MB mass and troponin I release were not different between the two groups of patients. CONCLUSION: The use of a leucocyte depleting arterial line filter is associated with an increased release of the proteolytic enzyme elastase, but does not reliably and consistently achieve effective leucocyte depletion during clinical perfusion. In contrast to previous studies, we could not demonstrate any significant difference in postbypass pulmonary or myocardial function between patients perfused with the leucocyte-specific arterial line filter and control patients. Our data do not support the routine use of a leucocyte depleting arterial line filter during clinical perfusion in patients undergoing elective aortocoronary bypass surgery. 相似文献
124.
A 45-year-old male was admitted to our hospital for investigation of a nodular shadow in segment 5 of the right lung on a
chest computed tomogram. A right middle lobectomy with mediastinal lymph node dissection was performed under a diagnosis of
lung cancer, and histologic examination confirmed small cell carcinoma. There were sarcoid reactions in the resected lymph
nodes and the lung parenchyma, but no signs of systemic sarcoidosis were evident. Sarcoid reactions are rarely observed in
the regional lymph nodes draining malignant tumors. Moreover, while they are most common in squamous cell carcinoma of the
lung, they extremely rare in small cell carcinoma. To our knowledge, this is only the third report of this unusual entity
in the English and Japanese literature. 相似文献
125.
Charles M. Haskell Evelyn Mendoza Katherine M.W. Pisters Frank V. Fossella Robert A. Figlin 《Investigational new drugs》1999,16(1):81-85
Fifteen patients with Stage IIIB or IV non-small cell lung cancer gave informed consent to receive three or more 96-hour infusions of ATP at a dose of 50 mcg/kg/min or higher to determine whether ATP has antineoplastic activity against this tumor type and to better define the spectrum of toxicity for ATP given as a single agent. There were no objective complete or partial responses observed. The median survival of the overall group was 187 days and the median time to tumor progression was 113 days. The major toxic side effects were chest pain and dyspnea, leading to the cessation of treatment in 5 patients. We conclude that ATP at this dose and schedule of administration is an inactive agent in patients with advanced non-small cell lung cancer. 相似文献
126.
Joseph D. Tobias 《Journal canadien d'anesthésie》1996,43(4):353-357
Purpose
To evaluate prospectively the efficacy and dose requirements of rocuronium administered by continuous infusion for neuromuscular blockade in a paediatric ICU population. 相似文献127.
Naohiro Kajiwara Masahiko Taguchi Hiroshi Saito Shin Nakajima Aeru Hayashi Norihiko Kawate Chimori Konaka Hiromi Wada Harubumi Kato 《Transplant international》1996,9(3):194-200
We examined the efficacy of two new preservation solutions containing trehalose-an extracellular type (ET-K) of solution and an intracellular type (IT-K) of solution — in relation to that of Euro-Collins (EC) solution in 20-h canine lung preservation. Canine lungs were flushed with one of the three solutions (n=5 for each solution) after pretreatment with PGE1 (20 g/kg) and were stored for 20 h at 4°C. The left lungs were transplanted and evaluated to 6 h post transplant. In the ET-K group, the arterial oxygen tension after reperfusion was significantly higher than in the IT-K and EC groups. The pulmonary vascular resistance, wet/dry weight ratio, and histological evaluation of each transplanted lung in the ET-K group were also better than in the IT-K and EC groups. This indicates that ET-K solution is useful for 20-h preservation of canine lung grafts. 相似文献
128.
The inhibitory effect of the thoracic duct lymph of a patient with lung cancer on the "one-way" mixed lymphocyte reaction without cytoxicity is unequivocally demonstrated. The effect seems to be dose related. A moderate inhibition of mixed lymphocyte reaction is still observed, even if the responding cells are preincubated in the thoracic duct lymph for 1 hr only prior to the addition of stimulating cells. The inhibitory effect of thoracic duct lymph on the mixed lymphocyte reaction is no longer evident when the material is added 1-4 days after the beginning of culture. These observations suggest that the mechanism of the inhibitory effect of thoracic duct lymph may be a simple attachment of inhibitory factors to the receptor sites on the responding lymphocytes, causing interference in cell to cell interaction. The inhibitory effect of thoracic duct lymph collected 1 week after the thoracic duct drainage on mixed lymphocyte reaction is significantly lower than that of thoracic duct lymph collected at the beginning of the procedure. This indicates that the blocking effect of thoracic duct lymph can be easily removed by this technique; which is technically feasible in man. The interrelationship of the tumor-specific blocking factor, thoracic duct drainage, and tumor growth pattern are discussed with respect to the potential usefulness of this procedure as adjuvant immunotherapy in the management of patients with neoplastic diseases. 相似文献
129.
高频振荡通气及联合硫酸镁治疗新生猪重症胎粪吸入综合征的实验研究 总被引:1,自引:0,他引:1
目的 探讨高频振荡通气 (HFOV)及联合硫酸镁 (Mg SO4 )治疗合并持续肺动脉高压(PPH)的重症胎粪吸入综合征 (MAS)模型氧合、循环功能 ,血镁浓度及肺组织病理改变。 方法 以2 0 %胎粪混悬液制备重症 MAS模型 ,健康新生猪随机分为 3组 ,即模型 HFOV治疗组 (HFOV组 ,n= 6 ) ,HFOV+Mg SO4 治疗组 (HFOV+Mg SO4 组 ,n=7) ,HFOV对照组 (对照组 ,n=5 ) ,HFOV+Mg SO4 组同时静脉持续泵入 Mg SO4 。监测生命体征、血气、血镁浓度。 结果 (1) HFOV和 HFOV+Mg SO4 治疗均使 MAS模型动脉血氧分压 (Pa O2 )、动脉血氧 /肺泡血氧分压比 (a/ APO2 )增加 ,肺泡-动脉血氧分压差 (A- a DO2 )、肺内分流 (Qs/ Qt)降低 ,治疗 30 min与治疗前比差异有非常显著性 (P<0 .0 1)。HFOV组各时间点 Pa O2 、a/ APO2 低于对照组 ,A- a DO2 、Qs/ Qt高于对照组 (P<0 .0 5 )。HFOV+Mg SO4 组治疗 12 0 m in后上述指标与对照组差异无显著性 (P>0 .0 5 )。 (2 )尽管氧合功能改善 ,单独 HFOV对重症 MAS的 PPH无降低作用 ,联合 Mg SO4 治疗 30 min即可有效降低 PPH(P<0 .0 5 ) ,并保持疗效。(3) HFOV组较 HFOV+Mg SO4 组有明显肺出血 ,出血沿肺段、小叶分布 ,两组病理评分差异有显著性 (P<0 .0 5 )。 (4) HFOV+Mg SO4 组血镁浓度较治疗 相似文献
130.
三维适形低分割放射治疗老年非小细胞肺癌疗效观察 总被引:19,自引:1,他引:19
目的 探讨三维适形低分割放射治疗老年非小细胞肺癌的疗效。方法 4 5例患者均采用低分割治疗 ,处方剂量为 4~ 5Gy,隔日 1次 ,总量 4 8~ 5 5Gy。结果 CR 2 3例 ( 5 1.1% ) ,PR 15例( 33.3% ) ,NC 5例 ( 11.1% ) ,PD 2例 ( 4 .4 % ) ,RR 38例 ( 84 .4 % )。 1、2、3年生存率分别为 6 6 .7%、4 8.9%、39.1%。结论 三维适形放射治疗对于老年非小细胞肺癌是一种反应较小 ,痛苦较轻 ,安全有效的治疗措施 相似文献