全文获取类型
收费全文 | 47684篇 |
免费 | 3174篇 |
国内免费 | 138篇 |
专业分类
耳鼻咽喉 | 615篇 |
儿科学 | 1138篇 |
妇产科学 | 667篇 |
基础医学 | 6202篇 |
口腔科学 | 776篇 |
临床医学 | 5300篇 |
内科学 | 9465篇 |
皮肤病学 | 715篇 |
神经病学 | 4107篇 |
特种医学 | 1781篇 |
外国民族医学 | 1篇 |
外科学 | 7632篇 |
综合类 | 598篇 |
一般理论 | 47篇 |
预防医学 | 4013篇 |
眼科学 | 983篇 |
药学 | 3528篇 |
1篇 | |
中国医学 | 45篇 |
肿瘤学 | 3382篇 |
出版年
2024年 | 201篇 |
2023年 | 285篇 |
2022年 | 454篇 |
2021年 | 1124篇 |
2020年 | 697篇 |
2019年 | 1060篇 |
2018年 | 1198篇 |
2017年 | 886篇 |
2016年 | 966篇 |
2015年 | 1042篇 |
2014年 | 1620篇 |
2013年 | 1919篇 |
2012年 | 3296篇 |
2011年 | 3282篇 |
2010年 | 1828篇 |
2009年 | 1558篇 |
2008年 | 2831篇 |
2007年 | 2979篇 |
2006年 | 2857篇 |
2005年 | 2881篇 |
2004年 | 2638篇 |
2003年 | 2474篇 |
2002年 | 2391篇 |
2001年 | 742篇 |
2000年 | 590篇 |
1999年 | 634篇 |
1998年 | 548篇 |
1997年 | 451篇 |
1996年 | 379篇 |
1995年 | 438篇 |
1994年 | 312篇 |
1993年 | 293篇 |
1992年 | 504篇 |
1991年 | 433篇 |
1990年 | 373篇 |
1989年 | 362篇 |
1988年 | 392篇 |
1987年 | 344篇 |
1986年 | 331篇 |
1985年 | 271篇 |
1984年 | 323篇 |
1983年 | 260篇 |
1982年 | 227篇 |
1981年 | 182篇 |
1980年 | 178篇 |
1979年 | 223篇 |
1978年 | 150篇 |
1976年 | 148篇 |
1975年 | 145篇 |
1974年 | 143篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
The age-dependence of the incidence of magnocellular neurosecretory neurons containing abnormal accumulations of peptide in the rough endoplasmic reticulum was examined in homozygous Brattleboro rats and in their wild-type Long Evans counterparts. Neurons in which the immunophenotype of the peptide aggregates indicate that somatic cross-over mutations involving the 5' end of the vasopressin gene and the 3' end of the oxytocin gene have occurred, increased with age in homozygous Brattleboro rats, reaching a maximum of 24 cells per hypothalamus (approximately 0.6% of the vasopressin neurons). The increase occurred in both male and female animals but was significantly greater in females. The average incidence of such cells was 6 times greater in the supraoptic than in the paraventricular nucleus. No such cells could be detected in either nucleus of Long Evans rats despite the evidence for hybrid mRNA in these animals. Moreover, no accumulation of peptide translated from the hybrid mRNAs derived from the 5' end of the oxytocin gene and the 3' end of the vasopressin gene could be detected in either Brattleboro or Long Evans animals. These results strongly suggest that the accumulation of peptide in the rough endoplasmic reticulum of vasopressin neurons in homozygous Brattleboro rats is due to an abnormality other than the somatic crossing-over mutation. A second type of abnormal magnocellular neuron with accumulations of peptide in the rough endoplasmic reticulum, in which the immunophenotype of the peptide reveals products derived only from the oxytocin precursor, was present in both Long Evans and Brattleboro rats, but did not increase with age in Brattleboro rats. The incidence of these cells was similar in the supraoptic and paraventricular nuclei. 相似文献
73.
Background. Craniocervical necrotizing fasciitis (CCNF) is a rapidly progressive, severe bacterial infection of the superficial fascial planes of the head and neck. Group A beta–hemolytic Streptococcus, staphylococcus aureus, and obligate anaerobic bacteria are common pathogens. The disease usually results from a dental source or facial trauma. Extensive fascial necrosis and severe systemic toxicity are common manifestations of CCNF. Recently the lay press has referred to necrotizing fasciitis in several articles about “flesh eating” bacteria, which have resulted in several deaths. Methods. We report the first case of a fatality in an otherwise immunocompetent patient. The patient was a 66-year-old black man with no identifiable source of infection and no history or evidence of immunocompromising disorders. Results. Despite aggressive surgical debridement and broad-spectrum antibiotic coverage, he died 30 hours after admission from multisystem organ failure secondary to overwhelming sepsis. Conclusion. Treatment consists of early recognition of CCNF combined with aggressive surgical debridement and drainage of the involved necrotic fascia and tissue along with broad-spectrum intravenous antibiotic coverage. Although 11 other fatal cases of CCNF have been previously reported, all had an underlying medical problem which created an immunocompromised state, usually diabetes mellitus or chronic alcoholism. We present a case report and literature review along with a discussion of the related anatomy. © 1995 Jons Wiley & Sons, Inc. 相似文献
74.
Daniel le Grange Jason Tibbs Timothy D. Noakes 《The International journal of eating disorders》1994,15(4):369-376
Competitive pressures to achieve a slim body shape may be of importance in the etiology of eating disorders in ballet dancers. This study examines the presence of anorexia nervosa-like symptoms in a group of 49 female ballet students (mean age = 18.9 years, SD ± 1.9). All students were assessed for certain physical (weight and height) and psychological (Eating Attitude Test [EAT]) indices at the start of their academic training year. Thereafter, all subjects who presented with anorexia nervosa-like symptoms (EAT ≥ 30, and/or with current secondary amenorrhea or primary amenorrhea if aged 16 years or over) at the initial assessment, were invited for a semistructured interview (Morgan-Russel scales) to determine their diagnostic status. Another aim of the study was to assess the prognostic implications of a diagnosis of anorexia nervosa in this sample. All subjects previously interviewed were invited for a follow-up assessment at 10 months. Anorexia nervosa could be diagnosed in 2 students (4.1%), whilst another 4 students (8.2%) presented with “partial syndrome” anorexia nervosa. All diagnosed students managed to complete their academic training year. The development and implications of a diagnosis of anorexia nervosa in the ballet students are discussed. 相似文献
75.
ATP as an Osteoclast Regulator? 总被引:1,自引:1,他引:0
76.
R Dixon AM Hughes K Nairn M Sellers JV Kemp RA Yates 《Cephalalgia : an international journal of headache》1998,18(7):468-475
Zolmitriptan (ZomigTM ) is a 5HT1B/1D agonist which has the ability to cross the intact blood-brain barrier to access central as well as peripheral receptors. Because of the potential for central nervous system side effects, this randomized, double-blind, placebo-controlled, 6-period crossover study evaluated the effects of 2.5 and 5 mg doses of zolmitriptan on psychomotor performance and investigated any pharmacodynamic or pharmacokinetic interaction with diazepam. Twelve healthy volunteers received the following "treatments" as single doses: zolmitriptan 2.5 mg, zolmitriptan 5 mg, diazepam 10 mg, zolmitriptan 2.5 mg+diazepam 10 mg, zolmitriptan 5 mg+diazepam 10 mg and placebo. Pre-dose and at 1, 4, 8, and 24 h post-dose, the following validated battery of psychomotor tests was performed: Bond-Lader visual analogue scales (calmness, contentedness, and alertness factors), critical flicker fusion test, choice reaction time (recognition, motor, and total reaction times), finger-tapping test, number cancellation test and digit symbol substitution test. Plasma concentrations of zolmitriptan, its active metabolite, and diazepam and its active metabolites were measured at the same timepoints. Zolmitriptan 2.5 and 5 mg had no effect on psychomotor function when given alone. In contrast, diazepam 10 mg had profound effects, consistent with its sedative properties, but there was no synergism on concomitant administration of either dose of zolmitriptan. Plasma concentrations of zolmitriptan, diazepam, and their respective active metabolites were similar when the two drugs were given alone or in combination. 相似文献
77.
C. J. English W. M. Maclaren C. Court-Brown S. P. F. Hughes R. W. Porter W. A. Wallace R. J. Graves A. J. Pethick C. A. Soutar 《American journal of industrial medicine》1995,27(1):75-90
To make a preliminary assessment of whether upper limb soft tissue disorders might be associated with activities at work, we have conducted a case-control study of subjects attending orthopedic clinics in three cities. All subjects between the ages of 16 and 65 years, in whom defined soft tissue conditions of the upper limb were diagnosed by the participating orthopedic surgeons, were invited to take part. Controls were subjects attending the same clinics within the same age range whose clinical diagnosis did not include disease of the upper limb, cervical or thoracic spine. Information concerning repetitive movements of the upper limbs at work was elicited by questionnaire. Five hundred eighty cases and 996 controls were studied, representing 96% and 93%, respectively, of those invited to participate. The diagnoses of the cases included soft tissue conditions affecting the shoulder, elbow, forearm, wrist, thumb, hand, and fingers. The diagnoses of the controls included traumatic, degenerative, and inflammatory conditions, mostly of the legs and lower back. Women predominated among the cases (70%) and men among the controls (56%). Of 221 female cases with injury to the wrist and forearm, 32 were cleaner/domestics (14.5%) compared to 35 of 439 controls (8%), a difference statistically significant at the 2 1/2% level. Other jobs significantly overrepresented (5% level) among female cases with injuries at various anatomical sites included hairdressers, secretary/temps, assembly line workers, and machine operators (type unspecified). Among male cases, electricians were significantly overrepresented (5% level). Jobs for which there was a suggestion (p < 0.1) of overrepresentation among cases included butchers and teacher/ lecturers (both males only) and the combined job groups (chosen a priori for analysis) of keyboard operators, machine operators, and music teachers (all three jobs, females only). 相似文献
78.
79.
80.
Jonathan H. Waters MD Timothy B. Watson MD Michael G. Ward MD 《Journal of clinical anesthesia》1996,8(8):656-658
Multiple reports of cauda equina syndrome and transient radicular nerve root irritation have suggested that lidocaine spinal anesthesia may be responsible. In this case report, a patient with a preexisting diabetic neuropathy received a partial block following a tetracaine spinal, which was followed by a lidocaine spinal. Following block resolution, a new conus medullaris syndrome was diagnosed. Because of the close proximity of the cauda equina and the conus medullaris, differentiation between these syndromes can be difficult. The preexisting diabetic neuropathy may have predisposed this patient to neurologic injury. The choice of a different local anesthetic drug with less neurotoxic potential such as bupivacaine may have prevented this injury. 相似文献