全文获取类型
收费全文 | 11537篇 |
免费 | 1072篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 83篇 |
儿科学 | 462篇 |
妇产科学 | 171篇 |
基础医学 | 1639篇 |
口腔科学 | 399篇 |
临床医学 | 1250篇 |
内科学 | 2166篇 |
皮肤病学 | 256篇 |
神经病学 | 774篇 |
特种医学 | 706篇 |
外科学 | 1434篇 |
综合类 | 256篇 |
一般理论 | 4篇 |
预防医学 | 1026篇 |
眼科学 | 210篇 |
药学 | 716篇 |
1篇 | |
中国医学 | 15篇 |
肿瘤学 | 1077篇 |
出版年
2021年 | 145篇 |
2020年 | 95篇 |
2019年 | 133篇 |
2018年 | 174篇 |
2017年 | 141篇 |
2016年 | 154篇 |
2015年 | 183篇 |
2014年 | 217篇 |
2013年 | 418篇 |
2012年 | 451篇 |
2011年 | 481篇 |
2010年 | 314篇 |
2009年 | 331篇 |
2008年 | 410篇 |
2007年 | 512篇 |
2006年 | 468篇 |
2005年 | 446篇 |
2004年 | 443篇 |
2003年 | 408篇 |
2002年 | 385篇 |
2001年 | 312篇 |
2000年 | 349篇 |
1999年 | 315篇 |
1998年 | 219篇 |
1997年 | 234篇 |
1996年 | 206篇 |
1995年 | 173篇 |
1994年 | 163篇 |
1993年 | 193篇 |
1992年 | 290篇 |
1991年 | 263篇 |
1990年 | 228篇 |
1989年 | 265篇 |
1988年 | 203篇 |
1987年 | 219篇 |
1986年 | 217篇 |
1985年 | 240篇 |
1984年 | 148篇 |
1983年 | 145篇 |
1982年 | 117篇 |
1981年 | 120篇 |
1980年 | 106篇 |
1979年 | 141篇 |
1978年 | 97篇 |
1977年 | 111篇 |
1976年 | 113篇 |
1974年 | 87篇 |
1973年 | 93篇 |
1972年 | 92篇 |
1971年 | 92篇 |
排序方式: 共有10000条查询结果,搜索用时 5 毫秒
91.
The monoclonal antibody NCRC-11, which has epithelial membrane antigen (EMA)-like immunoreactivity, was used to identify intracytoplasmic lumina in a series of 105 adenocarcinomas from various sites and in 283 breast carcinomas; 55% of the non-breast carcinomas and all breast carcinomas except one of spindle cell type contained intracytoplasmic lumina. The highest frequency (16.4% of tumour cells) was found in invasive lobular carcinoma of the breast. The use of antibodies with EMA reactivity is advocated in the routine investigation of metastatic and undifferentiated tumours. 相似文献
92.
The present investigation was conducted to determine whether norepinephrine or acetylcholine systems of the amygdala could be involved in two adaptive feeding behaviors in the rat: development of taste aversion and recovery from neophobia. In a taste aversion paradigm, a single bilateral injection of physostigmine directly into the amygdala at the onset of an apomorphine-induced illness experience produced a time-dependent attenuation in the development of taste aversion; in contrast, norepinephrine had no disruptive effects. In a neophobia paradigm, norepinephrine injected directly into the amygdala after a novel taste experience resulted in a time-dependent attenuation in recovery from neophobia; however, physostigmine produced no disruptive effects. Hence, acetylcholine appears to mediate taste-illness associations, while norepinephrine plays an important role in recovery from neophobia, i.e., taste-“learned safety” associations. 相似文献
93.
Dixon J Ellis I Bottani A Temple K Dixon MJ 《American journal of medical genetics. Part A》2004,(3):244-248
Treacher Collins syndrome (TCS) is an autosomal dominant disorder of facial development, which results from mutations in TCOF1. TCS comprises conductive hearing loss, hypoplasia of the mandible and maxilla, downward sloping palpebral fissures and cleft palate. Although, there is usually a reasonable degree of bilateral symmetry, a high degree of both inter- and intrafamilial variability is characteristic of TCS. The wide variation in the clinical presentation of different patients, together with the fact that more than 60% of cases arise de novo, can complicate the diagnosis of mild cases and genetic counselling. In the current study, we describe how molecular techniques have been used to facilitate pre- and postnatal disease diagnoses in 13 TCS families. 相似文献
94.
Treatment of chronic plaque psoriasis by selective targeting of memory effector T lymphocytes 总被引:41,自引:0,他引:41
Ellis CN Krueger GG;Alefacept Clinical Study Group 《The New England journal of medicine》2001,345(4):248-255
BACKGROUND: Psoriatic plaques are characterized by infiltration with CD4+ CD45RO+ and CD8+ CD45RO+ memory effector T lymphocytes. The recombinant protein alefacept binds to CD2 on memory effector T lymphocytes, inhibiting their activation. METHODS: In a multicenter, randomized, placebo-controlled, double-blind study, we evaluated alefacept as a treatment for psoriasis. Two hundred twenty-nine patients with chronic psoriasis received intravenous alefacept (0.025, 0.075, or 0.150 mg per kilogram of body weight) or placebo weekly for 12 weeks, with follow-up for 12 additional weeks. Before treatment, the median scores on the psoriasis area-and-severity index were between 14 and 20 in all groups (0 denotes no psoriasis and 72 the most severe disease possible). RESULTS: Alefacept was well tolerated and nonimmunogenic. The mean reduction in the score on the psoriasis area-and-severity index two weeks after treatment was greater in the alefacept groups (38, 53, and 53 percent in the groups receiving 0.025, 0.075, and 0.150 mg per kilogram, respectively) than in the placebo group (21 percent, P<0.001). Twelve weeks after treatment, 28 patients who had received alefacept alone were clear or almost clear of psoriasis. Three patients in the placebo group were clear or almost clear; all three had received additional systemic therapy for psoriasis. Alefacept reduced peripheral-blood memory effector T-lymphocyte (CD45RO+) counts, and the reduction in the number of memory-effector T lymphocytes was correlated with the improvement in psoriasis. CONCLUSIONS: Treatment with alefacept for 12 weeks is associated with improvement in chronic plaque psoriasis; some patients have a sustained clinical response after the cessation of treatment. Alefacept selectively targets CD45RO+ memory effector T lymphocytes, suggesting that they have a role in the pathogenesis of psoriasis. 相似文献
95.
Lei Li Christine Eng Robert J. Desnick James German Nathan A. Ellis 《Molecular genetics and metabolism》1998,64(4):286-290
Bloom syndrome is more common in individuals of Ashkenazi Jewish descent than in any other population, and one particular mutation in the Bloom syndrome gene,blmAsh,is homozygous in nearly all Ashkenazi Jewish persons with Bloom syndrome. We have determined the frequency ofblmAshin 1491 Ashkenazi Jewish persons with no known history of Bloom syndrome and found that 1 in 107 persons was heterozygous. Although not common, genetic screening for Bloom syndrome is feasible in this population. 相似文献
96.
Helen G. Morris M.D. Ittai Neuman M.D. Elliot F. Ellis M.D. 《The Journal of allergy and clinical immunology》1974,54(6):350-358
Plasma steroid concentrations were measured in asthmatic children 24 and 48 hours after administration of alternate-day treatment with prednisone, and the results were compared with those of control patients who did not receive corticosteroid treatment as well as those of patients who were treated with prednisone each day. It was found that 24 hours after administration of prednisone in any dose, plasma steroid concentrations were significantly lower than those of the control group. The degree of suppression in plasma steroid concentration was less marked in patients who received treatment on alternate days than in those who received the same doses of prednisone each day. Within 48 hours after administration of alternate-day treatment, plasma steroid concentrations approached the values observed in the control group and were independent of the magnitude of the prednisone dose. Although alternateday steroid treatment was associated with transient and incomplete suppression of pituitary-adrenal function, patients whose therapy was changed from a daily to an alternate-day regimen sometimes exhibited prolonged suppression of adrenal cortical function. 相似文献
97.
Visual function and academic performance 总被引:1,自引:0,他引:1
E M Helveston J C Weber K Miller K Robertson G Hohberger R Estes F D Ellis N Pick B H Helveston 《American journal of ophthalmology》1985,99(3):346-355
Evaluation of 1,910 first-, second-, and third-grade students indicated that visual function and academic performance as measured by reading were not positively related. Visual function tests included visual acuity, muscle balance, preferred eye and hand, color vision, refraction, sensory and motor function, and a writing and drawing task. Academic tests included the Metropolitan Readiness Test, the Cognitive Abilities Test, the Iowa Test of Basic Skills, and the teacher's assessment of reading level. A simple test which can be completed during the office visit and interpreted by the ophthalmologist in the office included drawing, copying, and writing. A segment of this test, the "draw a bicycle test," can be used by an ophthalmologist to demonstrate the difference between vision and performance when examining a child up to third-grade level who is referred because of school failure. 相似文献
98.
Naproxen in prophylaxis of migraine 总被引:2,自引:0,他引:2
Naproxen sodium is an inhibitor of platelet aggregation and prostaglandin synthesis and is also a potent anti-inflammatory agent. Because of these properties, it was evaluated in prophylaxis of migraine by a double-blind, placebo-controlled crossover study in 34 patients. Drug "preference" and therapeutic effect were rated by both patient and investigator. Overall, both preferred drug over placebo. An index of migraine activity was calculated from a daily record kept by the patient; it demonstrated a significant reduction in headache severity, duration, disability, and medication needed. Adverse effects were minimal and similar in drug and placebo. Naproxen is a promising agent in the prophylaxis of migraine. 相似文献
99.
S Jenkins C J Dickinson M A Heasman B W Ellis 《British medical journal (Clinical research ed.)》1986,292(6515):254-256
Four physicians comment on an issue paper from the Department of Health and Social Security about provisions of the Data Protection Act that would permit patient access to computerized health records in 1987 unless the Secretary of State rules otherwise. S. Jenkins, a general practitioner, fears that patient access would refocus the record on the doctor's best interests rather than the patient's. C.J. Dickinson, a medical professor, welcomes access as fostering trust. M.A. Heasman, a health administrator, opposes unrestricted access but urges physicians to reveal more to patients. B.W. Ellis, a consultant surgeon, holds that patients have a right to see their records, subject to physician discretion in disclosing information to the patient's general practitioner or other third party. An interprofessional working group's "Statement on subject access to personal health information" rejects unrestricted access lest it inhibit health professionals from recording sensitive data. 相似文献
100.
The challenge of rehabilitating young, healthy transfemoral amputees may extend beyond the boundaries of teaching them to adapt to functional activities of daily living. The goal for several of these amputees is to participate and sometimes even compete in recreational activities, including running. These amputee runners require prosthetic adaptations as well as a comprehensive individualized training programme to ensure that their running is as safe and energy efficient as possible. To help amputees achieve this, clinicians must understand normal and prosthetic locomotion. This paper compares the biomechanical differences between walking and running in normal locomotion and analyses the running modes used by transfemoral amputees. The modified running mode achieved with the Terry Fox Running Prosthesis subjectively "looks" more energy efficient to the observer and "feels" more energy efficient to the user. These assumptions have yet to be confirmed or refuted by a rigorous scientific research study. An outline of the proposed physiotherapy protocol includes the familiarization, treatment, and training phases. Physiotherapists involved in amputation rehabilitation may not be commonly confronted with this level of patient expectation. It is their responsibility to give realistic guidance to these amputees so that they can safely and independently pursue their recreational running activities. This need can best be fulfilled by providing sound clinical advice which has been validated by research findings. 相似文献