全文获取类型
收费全文 | 233116篇 |
免费 | 20803篇 |
国内免费 | 5017篇 |
专业分类
耳鼻咽喉 | 3519篇 |
儿科学 | 4369篇 |
妇产科学 | 3812篇 |
基础医学 | 18221篇 |
口腔科学 | 7483篇 |
临床医学 | 25002篇 |
内科学 | 21507篇 |
皮肤病学 | 2489篇 |
神经病学 | 11650篇 |
特种医学 | 6908篇 |
外国民族医学 | 11篇 |
外科学 | 22217篇 |
综合类 | 39701篇 |
现状与发展 | 10篇 |
一般理论 | 26篇 |
预防医学 | 31341篇 |
眼科学 | 2225篇 |
药学 | 21543篇 |
595篇 | |
中国医学 | 27063篇 |
肿瘤学 | 9244篇 |
出版年
2024年 | 1117篇 |
2023年 | 4788篇 |
2022年 | 8925篇 |
2021年 | 11696篇 |
2020年 | 11516篇 |
2019年 | 12552篇 |
2018年 | 10934篇 |
2017年 | 9655篇 |
2016年 | 8558篇 |
2015年 | 8061篇 |
2014年 | 16164篇 |
2013年 | 16539篇 |
2012年 | 14375篇 |
2011年 | 15294篇 |
2010年 | 12375篇 |
2009年 | 10680篇 |
2008年 | 9913篇 |
2007年 | 9907篇 |
2006年 | 8399篇 |
2005年 | 6968篇 |
2004年 | 5655篇 |
2003年 | 5030篇 |
2002年 | 3882篇 |
2001年 | 3216篇 |
2000年 | 2860篇 |
1999年 | 2306篇 |
1998年 | 1851篇 |
1997年 | 1668篇 |
1996年 | 1377篇 |
1995年 | 1291篇 |
1994年 | 1172篇 |
1993年 | 1043篇 |
1992年 | 964篇 |
1991年 | 854篇 |
1990年 | 754篇 |
1989年 | 719篇 |
1988年 | 675篇 |
1987年 | 611篇 |
1986年 | 569篇 |
1985年 | 1817篇 |
1984年 | 2132篇 |
1983年 | 1340篇 |
1982年 | 1766篇 |
1981年 | 1244篇 |
1980年 | 1053篇 |
1979年 | 942篇 |
1978年 | 770篇 |
1977年 | 583篇 |
1976年 | 728篇 |
1975年 | 501篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
急诊抗菌药物的使用调查与分析 总被引:1,自引:0,他引:1
目的考察了解急诊抗菌药物的使用情况。方法随机抽取2008年7—12月的急诊处方2700张,对其中抗菌药物的应用情况进行统计分析。结果急诊抗菌药物使用率49.1%,药物应用形式以单用为主(占66.3%);给药途径以口服和静脉注射为主。不合理用药处方占抗菌药物处方的10.8%,分别在选药方案、给药方案、溶媒使用、联合应用等方面存在问题。结论我院急诊抗菌药物的应用基本合理,但仍存在一定问题,需进一步加强管理。 相似文献
22.
23.
Diseases like rotavirus afflict both upper- and lower-income countries, but most serious illnesses and deaths occur among the latter. It is a vital public health issue that vaccines for these types of global diseases can recover research and development (R&D) costs from high-priced markets quickly so that manufacturers can offer affordable prices to lower-income nations. Cost recovery depends on how high R&D costs are, and this study attempts to replace high, unverified estimates with lower, more verifiable estimates for two new vaccines, RotaTeq (Merck) and Rotarix (GlaxoSmithKline or GSK), based on detailed searches of public information and follow-up interviews with senior informants. We also offer a new perspective on “cost of capital” as a claim for recovery from public bodies. Our estimates suggest that companies can recover all fixed costs quickly from affluent markets and thus can offer these vaccines to lower-income countries at prices they can afford. Better vaccines are a shared project between companies and public health agencies; greater transparency and consistency in reporting of R&D costs is needed so that fair prices can be established. 相似文献
24.
J. M. McGree J. A. Eccleston S. B. Duffull 《Journal of pharmacokinetics and pharmacodynamics》2009,36(2):101-123
We consider nested multiple response models which are used extensively in the area of pharmacometrics. Given the conditional
nature of such models, differences in predicted responses are a consequence of different assumptions about how the models
interact. As such, sequential versus simultaneous and First Order (FO) versus First Order Conditional Estimation (FOCE) techniques
have been explored in the literature where it was found that the sequential and FO approaches can produce biased results.
It is therefore of interest to determine any design consequences between the various methods and approximations. As optimal
design for nonlinear mixed effects models is dependent upon initial parameter estimates and an approximation to the expected
Fisher information matrix, it is necessary to incorporate any influence of nonlinearity (or parameter-effects curvature) into
our exploration. Hence, sequential versus simultaneous design with FO and FOCE considerations are compared under low, typical
and high degrees of nonlinearity. Additionally, predicted standard errors of parameters are also compared to empirical estimates
formed via a simulation/estimation study in NONMEM. Initially, design theory for nested multiple response models is developed
and approaches mentioned above are investigated by considering a pharmacokinetic–pharmacodynamic model found in the literature.
We consider design for situations where all responses are continuous and extend this methodology to the case where a response
may be a discrete random variable. In particular, for a binary response pharmacodynamic model, it is conjectured that such
responses will offer little information about all parameters and hence a sequential optimization, in the form of product design
optimality, may yield near optimal designs. 相似文献
25.
Massimo Porena Sauro Biscotto Elisabetta Costantini Ettore Mearini Livio Verdini 《Neurourology and urodynamics》2003,22(3):206-222
AIMS: The aim of this study is to compare PUMA curves with different pathologic conditions causing bladder dysfunction in 158 men and 83 women. METHODS: PUMA results in terms of bladder outlet obstruction and detrusor contractility were compared in 92 men with benign prostatic hypertrophy (BPH) and p(ves) congruent with p(det) (i.e., p(abd) congruent with 0) with the results of the urodynamics operator's opinion, the provisional International Continence Society method, Abrams and Griffith's diagram, urethral resistence factor (URA), Sch?fer's diagram, and Watt factor. PUMA curves correlated reliably with different pathologic conditions such as obstructive BPH, orthotopic bladder, cystocele, the neurological bladder, and bladder diverticulum. Statistical analysis indicated excellent agreement between PUMA and URA; agreement with other methods was good in cases of obstruction and nonobstruction. In doubtful cases, as diagnosed by standard methods, PUMA agreed only with the Abrams and Griffith's diagram. PUMA and Wmax were in good agreement on detrusor con traction force. Agreement between PUMA and Sch?fer's diagram was excellent for patients with detrusor hypercontractility and good for patients with detrusor hypocontractility and normocontractility. PUMA is the only method applicable to women. It is easy to perform. When integrated with other diagnostic tests, it provides realistic data for diagnosis, medical or surgical therapy, and outcome. 相似文献
26.
Teng-Yi Huang Hsiao-Wen Chung Fu-Nien Wang Cheng-Wen Ko Cheng-Yu Chen 《Magnetic resonance in medicine》2004,51(2):243-247
In this work the feasibility of separating fat and water signals using the balanced steady-state free precession (SSFP) technique is demonstrated. The technique is based on the observation (Scheffler and Hennig, Magnetic Resonance in Medicine 2003;49:395-397) that at the nominal values of TE = TR/2 in SSFP imaging, phase coherence can be achieved at essentially only two orientations (0 degrees and 180 degrees ) relative to the RF pulses in the rotating frame, under the assumption of TR < T2, and independently of the SSFP angle. This property allows in-phase and out-of-phase SSFP images to be obtained by proper choices of the center frequency offset, and thus allows the Dixon subtraction method to be utilized for effective fat-water separation. The TR and frequency offset for optimal fat-water separation are derived from theories. Experimental results from healthy subjects, using a 3.0 Tesla system, show that nearly complete fat suppression can be accomplished. 相似文献
27.
中风毒邪论是一种与传统中医中风病理有所不同的理论 ,在中风毒邪论指导下形成解毒通络方是较为理想的神经保护剂 ,可解决目前神经保护治疗的主要障碍 ,有望成为提高中医治疗中风急性期疗效的关键 相似文献
28.
目的明确Angiomemor(美国Simbionix公司生产)血管介入仿真模拟器是否有助于冠状动脉造影技术的掌握和提高。方法选取16名无血管放射介入经验的心血管医生,接受相同课时的冠状动脉介入造影理论培训后,按随机表编码随机分为模拟器培训组与非培训组各8名,模拟器培训组8名医生接受Angiomemor血管介入仿真模拟器培训,模拟冠状动脉造影操作,非培训组8名心血管医生未接受仿真模拟器培训。在随后的真实临床环境中操作冠状动脉造影时,评价2组医生冠状动脉造影操作过程中错误的频数、平均造影时间、造影剂使用量及术中放射线剂量。结果相对于非培训组,模拟器培训组医生在冠状动脉造影操作中错误频数减少62.5%、平均造影时间减少44.0%、造影剂使用量减少44.0%,术中平均放射线曝光时间减少了57.7%,平均X线累计曝光剂量减少51.6%,单位面积X线累计曝光剂量减少了52.4%。结论Angiomemor血管介入仿真模拟器有助于医生较快地熟练掌握冠状动脉造影技术,是冠状动脉介入规范化培训的重要辅助手段之一。 相似文献
29.
Robert M. Levy Roman Saikovsky Evgeniya Shmidt Alexander Khokhlov Bruce P. Burnett 《Nutrition Research》2009
Flavocoxid (Limbrel), a proprietary mixture of flavonoid molecules (baicalin and catechin), was tested against a traditional nonsteroidal anti-inflammatory drug, naproxen, for the management of the signs and symptoms of moderate osteoarthritis (OA) in humans. Discomfort and global disease activity were used as the primary end points, and safety assessments were also taken for both treatments as a secondary endpoint. In this double-blind study, 103 subjects were randomly assigned to receive either flavocoxid [500 mg twice daily (BID)] or naproxen (500 mg BID) in a 1-month onset of action trial. Outcome measures included the short Western Ontario and McMaster University Osteoarthritis Index, subject Visual Analogue Scale for discomfort and global response, and investigator Visual Analogue Scale for global response and fecal occult blood. Both flavocoxid and naproxen showed significant reduction in the signs and symptoms of knee OA (P ≤ .001). There were no statistically detectable differences between the flavocoxid and naproxen groups with respect to any of the outcome variables. Similarly, there were no statistically detectable differences between the groups with respect to any adverse event, although there was a trend toward a higher incidence of edema and nonspecific musculoskeletal discomfort in the naproxen group. In this short-term pilot study, flavocoxid was as effective as naproxen in controlling the signs and symptoms of OA of the knee and would present a safe and effective option for those individuals on traditional nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 inhibitors. A low incidence of adverse events was reported for both groups. 相似文献
30.
大学新生心理健康状况的调查研究 总被引:2,自引:0,他引:2
赵可军 《山东医学高等专科学校学报》2004,26(3):209-211
目的 了解大学新生的心理健康状况 ,探讨提高其心理健康水平的措施。方法 采用大学生人格问卷(UPI) ,以班级为单位 ,在新生正式上课两周以后进行测试。结果 学生一类筛选率 9.2 4 %。UPI关键题选择中 ,以常常失眠占的比例最高 ,想轻生的比例最低 (P <0 .0 5 )。UPI附加题选择中 ,以自身健康方面有问题及有健康或心理卫生方面想要咨询的问题较多 (P <0 .0 5 )。选择“想轻生”的男生的比例略高于女生 ,选择“常常失眠”的女生的比例却明显高于男生 (P <0 .0 5 ) ;选择“常常失眠”、“对任何事情都不感兴趣”和“感觉自己的过去及家庭不幸”的农村学生的比例都高于城市学生 (P <0 .0 5 )。选择“想轻生”和“对任何事情都不感兴趣”的独生子女的比例明显高于非独生子女 ,而选择“自己的过去和家庭是不行的”和“常常失眠”的非独生子女的比例又明显高于独生子女 (P <0 .0 5 )。结论 单亲家庭学生、残疾学生、家庭经济困难学生、独生子女学生是心理问题高危人群 相似文献