全文获取类型
收费全文 | 554730篇 |
免费 | 43545篇 |
国内免费 | 23838篇 |
专业分类
耳鼻咽喉 | 5490篇 |
儿科学 | 9347篇 |
妇产科学 | 9262篇 |
基础医学 | 68580篇 |
口腔科学 | 9779篇 |
临床医学 | 68819篇 |
内科学 | 98038篇 |
皮肤病学 | 6267篇 |
神经病学 | 41657篇 |
特种医学 | 21960篇 |
外国民族医学 | 226篇 |
外科学 | 69620篇 |
综合类 | 52345篇 |
现状与发展 | 77篇 |
一般理论 | 196篇 |
预防医学 | 35963篇 |
眼科学 | 15004篇 |
药学 | 47896篇 |
335篇 | |
中国医学 | 17754篇 |
肿瘤学 | 43498篇 |
出版年
2024年 | 1140篇 |
2023年 | 6313篇 |
2022年 | 15138篇 |
2021年 | 21502篇 |
2020年 | 14997篇 |
2019年 | 15775篇 |
2018年 | 17293篇 |
2017年 | 14251篇 |
2016年 | 14083篇 |
2015年 | 19882篇 |
2014年 | 25902篇 |
2013年 | 26327篇 |
2012年 | 39619篇 |
2011年 | 43332篇 |
2010年 | 25760篇 |
2009年 | 21379篇 |
2008年 | 32549篇 |
2007年 | 33366篇 |
2006年 | 32978篇 |
2005年 | 32535篇 |
2004年 | 25501篇 |
2003年 | 23366篇 |
2002年 | 21440篇 |
2001年 | 9380篇 |
2000年 | 9687篇 |
1999年 | 10995篇 |
1998年 | 8235篇 |
1997年 | 7686篇 |
1996年 | 6243篇 |
1995年 | 5674篇 |
1994年 | 4727篇 |
1993年 | 3583篇 |
1992年 | 3799篇 |
1991年 | 3335篇 |
1990年 | 2897篇 |
1989年 | 2599篇 |
1988年 | 2239篇 |
1987年 | 1963篇 |
1986年 | 1740篇 |
1985年 | 1586篇 |
1984年 | 1432篇 |
1983年 | 1159篇 |
1982年 | 1275篇 |
1981年 | 1202篇 |
1980年 | 1023篇 |
1979年 | 685篇 |
1978年 | 596篇 |
1977年 | 533篇 |
1976年 | 488篇 |
1974年 | 412篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
Barry L Eppley A Michael Sadove David Hennon John A van Aalst 《The Cleft palate-craniofacial journal》2006,43(3):374-378
OBJECTIVE: A series of nasopharyngeal appliance designs is presented that represents our evolving experience over a 20-year period in the adjunctive use of prosthetic stents in the surgical correction of nasopharyngeal stenosis. DESIGN: Retrospective assessment of effectiveness of two nasopharyngeal stenosis hollow stent designs in a consecutive series of patients for relief of nasal obstructive symptoms. SETTING: Tertiary academic medical center, Craniofacial Program at Children's Hospital. PATIENTS: Four patients with nasopharyngeal stenosis were treated with a preoperatively fabricated stent made from a clasped palatal appliance onto which hollow acrylic conduits were extended through surgically re-created pharyngeal ports. A subsequent set of four patients with nasopharyngeal stenosis were treated with intraoperatively-fashioned silastic grommets, as opposed to palatal appliances. INTERVENTIONS: Postoperative intraoral stenting of nasopharyngeal ports. MAIN OUTCOME MEASURES: Maintenance of pharyngeal port opening after 1 year, improvement in nasal airway obstructive symptoms. RESULTS: The palatal appliance stents were less well tolerated and had a lower maintenance of port patency after device removal (4 of 8, 50%). The silastic grommets provided better retention into the ports and increased patient tolerance, as well as better 1-year port maintenance (6 of 8, 75%). CONCLUSIONS: The grommet stent appliance offers numerous advantages over a conventional dental-clasped appliance for prosthetic nasopharyngeal stenting, including obviation of extensive preoperative preparation, ease of insertion and removal, and exchange of air during the stenting period. Improved nasopharyngeal patency with this device may be due to greater patient tolerance and subsequent longer use. 相似文献
13.
Hideki Kawaguchi Kazuko Masuo Tomohiro Katsuya Ken Sugimoto Hiromi Rakugi Toshio Ogihara Michael L Tuck 《Hypertension research》2006,29(12):951-959
High blood pressure (BP) is a major determinant of cardiovascular events in obesity. The beta2- and beta3-adrenoceptor polymorphisms are associated with obesity and hypertension. In the present study, we examine the relationships of beta2- and beta3-adrenoceptor polymorphisms with further weight gain-induced BP elevation in obese subjects. Changes in BP, body weight, total body fat-mass, waist-to-hip ratio, plasma norepinephrine (NE) and leptin levels, and beta2(Arg16Gly)- and beta3(Trp64Arg)-adrenoceptor polymorphisms were measured periodically over a 5-year period in 55 entry obese (body mass index [BMI]> or =25.0 kg/m(2)) normotensive (BP<140/90 mmHg) men. BP elevation and weight gain were defined as > or =10% increases from entry levels over 5 years in mean BP or BMI. Obese subjects with weight gain, BP elevation or weight gain-induced BP elevation had higher frequencies of the Gly16 allele of Arg16GIy and Arg64 allele of Trp64Arg. Subjects carrying the Gly16 or Arg64 alleles had significantly greater total fat-mass and waist-to-hip ratio at entry and over a 5-year period compared to the subjects who did not carry these polymorphisms. Subjects carrying the Gly16 allele had similar levels of plasma NE, higher levels of plasma leptin and a lower slope of the regression lines between plasma leptin and NE levels. Those carrying the Arg64 allele had higher plasma NE levels at entry and over a 5-year period compared to the subjects without the Arg64 allele, but plasma leptin levels and slopes were similar. The findings demonstrate that the Arg64 allele of the beta3-adrenoceptor polymorphisms relates to weight gain-induced BP elevation accompanying high plasma NE (heightened sympathetic activity) in obese men. The Gly16 allele of the beta2-adrenoceptor polymorphisms links to weight gain-induced BP elevation associated with leptin resistance. beta2- and beta3-adrenoceptor polymorphisms could predict the future BP elevation and further weight gain-induced BP elevation in originally obese subjects. 相似文献
14.
15.
16.
Harvey A. Siegal PhD ; Paul J. Draus PhD ; Robert G. Carlson PhD ; Russel S. Falck MA ; Jichuan Wang PhD 《The Journal of rural health》2006,22(2):169-173
CONTEXT: Although the nonmedical use of stimulant drugs such as cocaine and methamphetamine is increasingly common in many rural areas of the United States, little is known about the health beliefs of people who use these drugs. PURPOSE: This research describes illicit stimulant drug users' views on health and health-related concepts that may affect their utilization of health care services. METHODS: A respondent-driven sampling plan was used to recruit 249 not-in-treatment, nonmedical stimulant drug users who were residing in 3 rural counties in west central Ohio. A structured questionnaire administered by trained interviewers was used to collect information on a range of topics, including current drug use, self-reported health status, perceived need for substance abuse treatment, and beliefs about health and health services. FINDINGS: Participants reported using a wide variety of drugs nonmedically, some by injection. Alcohol and marijuana were the most commonly used drugs in the 30 days prior to the interview. Powder cocaine was used by 72.3% of the sample, crack by 68.3%, and methamphetamine by 29.7%. Fair or poor health status was reported by 41.3% of the participants. Only 20.9% of the sample felt they needed drug abuse treatment. Less than one third of the sample reported that they would feel comfortable talking to a physician about their drug use, and 65.1% said they preferred taking care of their problems without getting professional help. CONCLUSIONS: Stimulant drug users in rural Ohio are involved with a range of substances and hold health beliefs that may impede health services utilization. 相似文献
17.
We report clinical, neuroradiologic features, and neuropathologic findings of a 76‐year‐old man with coexistent Pick’s disease and progressive supranuclear palsy. The patient presented with loss of recent memory, abnormal behavior and change in personality at the age of 60. The symptoms were progressive. Three years later, repetitive or compulsive behavior became prominent. About 9 years after onset, he had difficulty moving and became bed‐ridden because of a fracture of his left leg. His condition gradually deteriorated and he developed mutism and became vegetative. The patient died from pneumonia 16 years after the onset of symptoms. Serial MRI scans showed progressive cortex atrophy, especially in the bilateral frontal and temporal lobes. Macroscopic inspection showed severe atrophy of the whole brain, including cerebrum, brainstem and cerebellum. Microscopic observations showed extensive superficial spongiosis and severe neuronal loss with gliosis in the second and third cortical layers in the frontal, temporal and parietal cortex. There were Pick cells and argyrophilic Pick bodies, which were tau‐ and ubiquitin‐positive in neurons of layers II–III of the above‐mentioned cortex. Numerous argyrophilic Pick bodies were observed in the hippocampus, especially in the dentate fascia. In addition, moderate to severe loss of neurons was found with gliosis and a lot of Gallyas/tau‐positive globus neurofibrillary tangles in the caudate nucleus, globus pallidus, thalamus, substantia nigra, locus coeruleus and dentate nucleus. Numerous thorned‐astrocytes and coiled bodies but no‐tuft shaped astrocytes were noted in the basal ganglion, brainstem and cerebellar white matter. In conclusion, these histopathological features were compatible with classical Pick’s disease and coexistence with progressive supranuclear palsy without tuft‐shaped astrocytes. 相似文献
18.
Shao-Liang Chen Tim-Mo Chen Hsian-Jenn Wang 《Journal of plastic, reconstructive & aesthetic surgery》2006,59(8):846-855
Finding appropriate soft-tissue to cover a wound located over the middle or distal portion of the foot can be challenging. A distally based sural fasciomusculocutaneous flap including the sural nerve and a midline cuff of the gastrocnemius muscle can be used for this purpose. This flap is designed on the proximal third of the posterior calf and is nourished in a retrograde manner by the lower peroneal septocutaneous perforators, through the vascular axis of the sural nerve to the musculocutaneous perforators of the gastrocnemius muscle. Between October of 2002 and January of 2004, this flap was applied in nine individuals, including four diabetic patients. The skin defects all resulted from trauma, osteomyelitis or chronic ulcer, and combined with bone or tendon exposure. One flap developed distal necrosis. The other flaps survived fully and provided good contour. In our series, diabetes mellitus seemed not to compromise the vascularity of the flap. The distally based sural fasciomusculocutaneous flap is very useful for lower limb reconstruction, particularly for the foot, because of its long vascular pedicle and the availability of the skin portion of the proximal calf based on direct branches between the musculocutaneous perforators and the neurovascular axis of the sural nerve. This is an important variant of the sural neurocutaneous flap and it appears to be a good alternative to free flaps for resurfacing the foot. 相似文献
19.
20.
Dear Sir In the recently published Task force report, under section Fibrinolyticregimens, the authors recommend not to re-administerstreptokinase for at least 10 years. The reference supportingthis statement is Ref. 51. After evaluating this paper and lookinginto the literature my comments 相似文献