全文获取类型
收费全文 | 130030篇 |
免费 | 11850篇 |
国内免费 | 7858篇 |
专业分类
耳鼻咽喉 | 1411篇 |
儿科学 | 1573篇 |
妇产科学 | 1206篇 |
基础医学 | 15668篇 |
口腔科学 | 2194篇 |
临床医学 | 14966篇 |
内科学 | 19478篇 |
皮肤病学 | 1983篇 |
神经病学 | 6760篇 |
特种医学 | 6137篇 |
外国民族医学 | 39篇 |
外科学 | 13331篇 |
综合类 | 20672篇 |
现状与发展 | 40篇 |
一般理论 | 12篇 |
预防医学 | 8719篇 |
眼科学 | 3618篇 |
药学 | 14099篇 |
115篇 | |
中国医学 | 6671篇 |
肿瘤学 | 11046篇 |
出版年
2024年 | 341篇 |
2023年 | 1678篇 |
2022年 | 4318篇 |
2021年 | 5937篇 |
2020年 | 4319篇 |
2019年 | 3869篇 |
2018年 | 4123篇 |
2017年 | 3899篇 |
2016年 | 4100篇 |
2015年 | 6068篇 |
2014年 | 7423篇 |
2013年 | 7339篇 |
2012年 | 10659篇 |
2011年 | 11348篇 |
2010年 | 7770篇 |
2009年 | 6408篇 |
2008年 | 7911篇 |
2007年 | 7637篇 |
2006年 | 7120篇 |
2005年 | 6557篇 |
2004年 | 4868篇 |
2003年 | 4969篇 |
2002年 | 4165篇 |
2001年 | 2953篇 |
2000年 | 2387篇 |
1999年 | 2177篇 |
1998年 | 1347篇 |
1997年 | 1242篇 |
1996年 | 963篇 |
1995年 | 967篇 |
1994年 | 817篇 |
1993年 | 527篇 |
1992年 | 646篇 |
1991年 | 537篇 |
1990年 | 450篇 |
1989年 | 431篇 |
1988年 | 287篇 |
1987年 | 306篇 |
1986年 | 256篇 |
1985年 | 156篇 |
1984年 | 94篇 |
1983年 | 60篇 |
1982年 | 63篇 |
1981年 | 42篇 |
1980年 | 42篇 |
1979年 | 31篇 |
1974年 | 12篇 |
1973年 | 23篇 |
1972年 | 15篇 |
1969年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Wen Wang Yanmei Liu Chuan Yu Jing Tan Weiyi Xiong Duo Dong 《Expert opinion on drug safety》2020,19(3):339-347
ABSTRACTObjectives: Limited evidence has suggested that cefoperazone-sulbactam causes coagulation disorders and bleeding.Methods: The authors conducted a retrospective study to compare patients receiving cefoperazone-sulbactam versus those treated with cefoperazone-tazobactam or ceftazidime. Propensity-score matching was used to explore whether treatment with cefoperazone-sulbactam increased the risk of prothrombin time (PT) prolongation, coagulation disorders, and bleeding, or decreased platelets (PLT).Results: The cohort included 23,242 patients. Among patients receiving cefoperazone-sulbactam, the risk of PT prolongation, coagulation disorders, decreased PLT, and bleeding was 5.3%, 9.2%, 15.7%, and 4.2%, respectively. Propensity-score matching analyses suggested that cefoperazone-sulbactam increased the risk of PT prolongation (aOR 2.26, 95% CI 1.61–3.18), coagulation disorders (aOR 1.81, 95% CI 1.43–2.30), and decreased PLT (aOR 1.46, 95% CI 1.25–1.72), but not increase bleeding (aOR 1.05, 95% CI 0.79–1.40) compared with ceftazidime. Patients receiving cefoperazone-sulbactam had higher risk of PT prolongation (aOR 1.53, 95% CI 1.11–2.10), coagulation disorders (aOR 1.53, 95% CI 1.21–1.95), but not decreased PLT (aOR 0.93, 95% CI 0.81–1.07) or bleeding (aOR 1.11, 95% CI 0.87–1.42), compared with those receiving cefoperazone-tazobactam.Conclusion: Cefoperazone-sulbactam may be associated with a higher risk of PT prolongation and coagulation disorders compared with cefoperazone-tazobactam and ceftazidime. 相似文献
62.
Ye Gao Lei Xin Yu-Xin Wang Yuan-Hang Dong Zhuan Liao 《Scandinavian journal of gastroenterology》2020,55(1):105-113
AbstractBackground and aim: Capsule retention is the most common adverse event associated with video capsule endoscopy. The use of double-balloon enteroscopy-assisted capsule endoscope retrieval has been increasingly reported in recent years. However, evidence is limited regarding its success rate, associated factors, and subsequent clinical outcomes.Methods: A systematic review of relevant studies published before January 2019 was performed. Successful retrieval rate and associated factors, rate of endoscopic balloon dilation, and outcomes after double-balloon enteroscopy were summarized and pooled.Results: Within 154 associated original articles, 12 including 150 cases of capsule retrieval by double-balloon enteroscopy were included. The estimated pooled successful retrieval rate was 86.5% (95% confidence interval, 75.6–95.1%). Anterograde approach and capsules retained in the jejunum or trapped by malignant strictures were associated with a higher successful retrieval rate than the retrograde approach (62/83 [74.7%] vs. 10/38 [26.3%], p?<?.001) and capsules retained in the ileum (41/41 [100.0%] vs. 43/58 [74.1%], p?<?.001) or trapped by benign strictures (21/21 [100.0%] vs. 65/83 [78.3%], p?=?.043). Endoscopic balloon dilation was performed in 38.8% (95% confidence interval, 22.3–56.3%) of patients with benign strictures. Two perforations (1.3%) were reported as severe adverse events after double-balloon enteroscopy. A significantly lower surgery rate was found among cases with successful video capsule removal compared with unsuccessful cases (7.2% vs. 38.5%, p?=?.002).Conclusions: Double-balloon enteroscopy is feasible and safe for removing retained video capsule endoscopes, and its use could decrease the need for surgery in patients with benign strictures and facilitate subsequent surgery in patients with malignant strictures. 相似文献
63.
64.
65.
OBJECTIVES: To assess the effectiveness and safety of additional bedtime H2‐receptor antagonists (H2RAs) in suppressing nocturnal gastric acid breakthrough (NAB) via a systematic review. METHODS: Eligible trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library Issue 2, 2004), MEDLINE (January 1966–June 2004), EMBASE (January 1980–June 2004) and CINAHL (January 1982–June 2004). Additional hand‐searching was conducted on the proceedings of correlated conferences, eight important Chinese journals and references of all included trials. All randomized controlled trials evaluating H2RAs for the control of NAB were eligible for inclusion. The systematic review was conducted using methods recommended by The Cochrane Collaboration. RESULTS: Only two randomized crossover studies, comprising 32 participants, met the inclusion criteria. Because the design, dosage and duration of the treatments were different between the studies, it was not possible to conduct meta‐analysis. There were no consistent conclusions found between the two included studies in evaluating H2RAs for the control of NAB. CONCLUSIONS: No implications for practice at this stage can be concluded. Appropriately designed large‐scale randomized controlled trials with long‐term follow up are needed to determine the effects of additional bedtime H2RAs in suppressing NAB. 相似文献
66.
67.
Kei Kamide Yoshihiro Kokubo Hironori Hanada Junko Nagura Jin Yang Shin Takiuchi Chihiro Tanaka Mariko Banno Yoshikazu Miwa Masayoshi Yoshii Tetsutaro Matayoshi Hisayo Yasuda Takeshi Horio Akira Okayama Hitonobu Tomoike Yuhei Kawano Toshiyuki Miyata 《Hypertension research》2006,29(4):243-252
Mutations in the gene encoding 11beta-hydroxysteroid dehydrogenase type 2, HSD11B2, cause a rare monogenic juvenile hypertensive syndrome called apparent mineralocorticoid excess (AME). In AME, defective HSD11B2 enzyme activity results in overstimulation of the mineralocorticoid receptor (MR) by cortisol, causing sodium retention, hypokalemia, and salt-dependent hypertension. Here, we have studied whether genetic variations in HDS11B2 are implicated in essential hypertension in Japanese hypertensives and the general population. By sequencing the entire coding region and the promoter region of HDS11B2 in 953 Japanese hypertensives, we identified five missense mutations in 11 patients (L14F, n = 5; R74H, n = 1; R147H, n = 3; T156I, n = 1; R335H, n = 1) and one novel frameshift mutation (4884Gdel, n = 1) in a heterozygous state, in addition to 19 genetic variations. All genetic variations identified were rare, with minor allele frequencies less than 0.005. Four of 12 patients with the missense/frameshift mutations showed renal failure. Four missense mutations, L14F, R74H, R147H, and R335H, were successfully genotyped in the general population, with a sample size of 3,655 individuals (2,175 normotensives and 1,480 hypertensives). Mutations L14F, R74H, R147H, and R335H were identified in hypertensives (n = 6, 8, 3, and 0, respectively) and normotensives (n = 8, 12, 5, and 0, respectively) with a similar frequency, suggesting that these missense mutations may not strongly affect the etiology of essential hypertension. Since the allele frequency of all of the genetic variations identified in this study was rare, an association study was not conducted. Taken together, our results indicate that missense mutations in HSD11B2 do not substantially contribute to essential hypertension in Japanese. 相似文献
68.
应用64层CT一次扫描完成心脏冠脉成像及心功能分析的可行性初步研究 总被引:1,自引:0,他引:1
目的研究64层CT一次扫描同时完成心脏冠脉成像及心功能分析的可行性。方法96例患者均行MSCT心脏成像扫描和MR心脏检查,数据分别按照冠脉成像和心功能分析要求进行重建和后处理,评估。结果1271段冠脉血管中有约99%血管显示清晰,达到诊断要求;心功能分析数据左室舒张末期容积(LVEDV)、左室收缩末期容积(LVESV)、左室每搏输出量(LVSV)、左室射血分数(LVEF)、左室心肌容积(LVMV)与MR相关数据的相关系数分别为0.84、0.91、0.94、0.89、0.88。结论MSCT可以在一次扫描中完成冠脉成像和心功能数据采集,具有极高应用价值。 相似文献
69.
小颗粒致密低密度脂蛋白氧化特性及对血管内皮细胞脂质过氧化的影响 总被引:6,自引:1,他引:5
了解小颗粒致密低密度脂蛋白中抗氧化维生素含量、氧化特性 ,探讨其对血管内皮细胞脂质过氧化的影响。采用二次密度梯度超速离心的方法分离制备小颗粒致密低密度脂蛋白 ,高压液相色谱测定其抗氧化物质维生素A、E和 β 胡萝卜素 ;连续监测小颗粒致密低密度脂蛋白在 2 34nm的吸光度以测定其氧化敏感曲线 ;在血管内皮培养液中分别加入不同浓度的小颗粒致密低密度脂蛋白 ,培养后测定培养液丙二醛的浓度。实验成功分离小颗粒致密低密度脂蛋白 ,与大而轻低密度脂蛋白相比 ,维生素A、E和 β 胡萝卜素等抗氧化物质及总抗氧化能力明显减少 ,只有大而轻低密度脂蛋白的 6 5 %、39%和 2 4 % ,故小颗粒致密低密度脂蛋白氧化的延迟时间只有大而轻低密度脂蛋白的 37.5 % ,但硫代巴比妥酸反应物质值及氧化速率分别是大而轻低密度脂蛋白的 1 .7倍和 1 .2 8倍 ;培养液中丙二醛含量随加入脂蛋白的浓度和作用时间而增高 ,2 4h时小颗粒致密低密度脂蛋白 5 0mg组、1 0 0mg组、1 5 0mg组与相同剂量大而轻低密度脂蛋白组比较丙二醛显著增高 (P <0 .0 5 )。上述结果提示 :小颗粒致密低密度脂蛋白中抗氧化物质及抗氧化能力下降 ,氧化敏感性增高 ,并促进内皮细胞过氧化损伤 相似文献
70.
管理人员职业紧张常模及转换表研制 总被引:1,自引:1,他引:0
目的中高层管理人员、一般管理人员职业紧张常模、应用表、分级标准研究。方法采用职业紧张量表(OSI-R),对中高层管理人员263例、一般管理人员569例,共计832例常模样本进行研究。结果首先,采用OSI-R量表分别研制了中高层管理人员、一般管理人员职业紧张常模;其次,在常模的基础上,分别研制了常模样本粗分转换为T分表。职业紧张程度分级职业任务和紧张反应问卷中,T分≥70分者,为高度职业紧张、紧张反应;T分在60分至69分范围内者,为中度职业紧张、紧张反应;T分在40分至59分范围内者,为适度职业紧张和紧张反应;处于正常范围。T分低于40分者,为相对缺乏职业紧张和紧张反应。在应对资源问卷中,T分低于30分者,表明高度缺乏应对资源;T分在30分至39分范围内者,表明中度缺乏应对资源;T分在40分至59分范围之间者,具有适度的应对资源,属于正常范围;T分≥60分者,表明有很强的应对资源。结论将职业紧张的模式结合中高层管理人员、一般管理人员职业紧张常模及应用表,分别针对不同个体主要紧张源、紧张反应、应对资源,采取有针对性的干预(组织、个体)措施,以降低中高层管理人员、一般管理人员职业紧张程度,保护和促进工作能力是职业卫生领域面临的重要任务之一。 相似文献