全文获取类型
收费全文 | 50608篇 |
免费 | 4069篇 |
国内免费 | 399篇 |
专业分类
耳鼻咽喉 | 815篇 |
儿科学 | 1014篇 |
妇产科学 | 957篇 |
基础医学 | 8055篇 |
口腔科学 | 773篇 |
临床医学 | 4739篇 |
内科学 | 10178篇 |
皮肤病学 | 1670篇 |
神经病学 | 4400篇 |
特种医学 | 2835篇 |
外科学 | 5913篇 |
综合类 | 510篇 |
现状与发展 | 1篇 |
一般理论 | 16篇 |
预防医学 | 3258篇 |
眼科学 | 1340篇 |
药学 | 4284篇 |
中国医学 | 424篇 |
肿瘤学 | 3894篇 |
出版年
2023年 | 297篇 |
2022年 | 814篇 |
2021年 | 1331篇 |
2020年 | 729篇 |
2019年 | 1135篇 |
2018年 | 1285篇 |
2017年 | 1003篇 |
2016年 | 1484篇 |
2015年 | 1928篇 |
2014年 | 2272篇 |
2013年 | 2686篇 |
2012年 | 3819篇 |
2011年 | 3697篇 |
2010年 | 2263篇 |
2009年 | 1879篇 |
2008年 | 2656篇 |
2007年 | 2641篇 |
2006年 | 2374篇 |
2005年 | 2248篇 |
2004年 | 1921篇 |
2003年 | 1705篇 |
2002年 | 1572篇 |
2001年 | 971篇 |
2000年 | 942篇 |
1999年 | 808篇 |
1998年 | 384篇 |
1997年 | 347篇 |
1996年 | 298篇 |
1995年 | 296篇 |
1994年 | 245篇 |
1993年 | 263篇 |
1992年 | 593篇 |
1991年 | 617篇 |
1990年 | 531篇 |
1989年 | 583篇 |
1988年 | 585篇 |
1987年 | 580篇 |
1986年 | 494篇 |
1985年 | 500篇 |
1984年 | 400篇 |
1983年 | 325篇 |
1982年 | 244篇 |
1981年 | 221篇 |
1980年 | 200篇 |
1979年 | 295篇 |
1978年 | 256篇 |
1977年 | 183篇 |
1974年 | 201篇 |
1973年 | 219篇 |
1972年 | 174篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
91.
B Young 《Neurologic Clinics》1988,6(3):639-644
Appropriate treatment of an intracranial lesion is based upon establishing a definitive diagnosis. CT-stereotactic biopsy procedures are highly accurate, are associated with few complications, and are usually performed only with local anesthesia. Stereotactic biopsy is the preferred method for histologically confirming the nature of an intracranial lesion in the immunocompromised patient. The mortality and morbidity approach 1 per cent, respectively. In the large reported series of stereotactic surgery for biopsy, diagnostic accuracy is over 95 per cent. Stereotactic techniques can also be used to aspirate abscesses or localize abscesses or neoplastic lesions excised by craniotomy. 相似文献
92.
The frequency properties of arterial beds in organs were studied by temporarily ligating the renal, the gastric, the splenic or the superior mesenteric arteries of rats. Blood-pressure waves of the tail arteries were recorded before and during the ligations, and were analysed by Fourier's transformation. Their frequency spectra have been found to change profiles following specific patterns with the ligations of different arteries. The results were significant with regard to the frequency selectivities of the organic arterial beds. Such frequency properties can be clearly explained when the circulation system is viewed as an electrical circuit network in which the organic arterial beds work as filters. 相似文献
93.
S Young Yim S Young Yim W O Walker J F McLaughlin 《Zeitschrift für Kinderchirurgie》2004,14(2):108-111
The clinical records of twenty-five children with exstrophy of the cloaca (EC) were retrospectively reviewed to evaluate the prevalence and the clinical characteristics of iron deficiency anemia (IDA). Five of the 25 children with EC (20 %) exhibited IDA at some point. Their ages at the time of diagnosis were between 1.9 and 13.0 years. In the four cases where IDA was thought to be related to iron malabsorption secondary to short-bowel syndrome, its treatment required longer periods of iron supplementation to correct the anemia and to restore the total body iron stores. Physicians caring for children with EC should monitor for and treat IDA as part of a comprehensive management plan. 相似文献
94.
Lara Kevorkian David A. Young Clare Darrah Simon T. Donell Lee Shepstone Sarah Porter Sarah Brockbank Dylan R. Edwards rew E. Parker Ian M. Clark 《International journal of experimental pathology》2004,85(1):A23-A23
Objective To profile the expression of all known members of the matrix metalloproteinase ( MMP ), a disintegrin and metalloproteinase with thrombospondin motifs ( ADAMTS ), and tissue inhibitor of metalloproteinases ( TIMP s) gene families in normal cartilage and that from patients with osteoarthritis (OA).
Methods Human cartilage was obtained from femoral heads at joint replacement for either osteoarthritis or following fracture to the neck of femur. Total RNA was purified and expression of genes assayed using quantitative real-time PCR.
Results Several members of the above gene families were regulated in OA. Genes increasing in expression in OA were: at P < 0.001, MMP-13 , MMP-28 , ADAMTS-16 ; at P < 0.01, MMP-9 , MMP-16 , ADAMTS-2 , ADAMTS-14 and at P < 0.05, MMP-2 , TIMP-3 , ADAMTS-12 . Genes decreasing in expression in OA were: at P < 0.001, MMP-1 , MMP-3 , ADAMTS-1 ; at P < 0.01, MMP-10 , TIMP-1 , ADAMTS-9 and at P < 0.05, TIMP-4 , ADAMTS-5 , ADAMTS-15 . Correlation analysis revealed that groups of genes across the gene families are co-expressed in cartilage.
Conclusion This is the first comprehensive expression profile of all known MMP , ADAMTS and TIMP genes in cartilage. Patterns of expression provide a foundation on which to understand mechanisms of gene regulation in OA and potentially for refining the specificity of anti-proteolytic therapies. 相似文献
Methods Human cartilage was obtained from femoral heads at joint replacement for either osteoarthritis or following fracture to the neck of femur. Total RNA was purified and expression of genes assayed using quantitative real-time PCR.
Results Several members of the above gene families were regulated in OA. Genes increasing in expression in OA were: at P < 0.001, MMP-13 , MMP-28 , ADAMTS-16 ; at P < 0.01, MMP-9 , MMP-16 , ADAMTS-2 , ADAMTS-14 and at P < 0.05, MMP-2 , TIMP-3 , ADAMTS-12 . Genes decreasing in expression in OA were: at P < 0.001, MMP-1 , MMP-3 , ADAMTS-1 ; at P < 0.01, MMP-10 , TIMP-1 , ADAMTS-9 and at P < 0.05, TIMP-4 , ADAMTS-5 , ADAMTS-15 . Correlation analysis revealed that groups of genes across the gene families are co-expressed in cartilage.
Conclusion This is the first comprehensive expression profile of all known MMP , ADAMTS and TIMP genes in cartilage. Patterns of expression provide a foundation on which to understand mechanisms of gene regulation in OA and potentially for refining the specificity of anti-proteolytic therapies. 相似文献
95.
96.
97.
Laurence J Kirmayer Morton Weinfeld Giovani Burgos Guillaume Galbaud du Fort Jean-Claude Lasry Allan Young 《Revue canadienne de psychiatrie》2007,52(5):295-304
OBJECTIVE: Research in the United States tends to attribute low rates of use of mental health services by immigrants to economic barriers. The purpose of our study was to examine this issue in the context of Canada's universal health care system. METHODS: A survey of the catchment area of a comprehensive clinic in Montreal interviewed random samples of 924 Canadian-born individuals and 776 immigrants born in the Caribbean (n = 264), Vietnam (n = 234), or the Philippines (n = 278) to assess their health care use for somatic symptoms, psychological distress, and recent life events. RESULTS: Overall rates of use of medical services in the past year were similar in immigrant (78.5%) and nonimmigrant (76.5%) groups. Rates of use of health care services for psychological distress were significantly lower among immigrants (5.5% compared with 14.7%, P < 0.001). This difference was attributable both to a lower rate of use of specialty mental health services by immigrants (2.5% compared with 11.7%, P < 0.001) and to differential use of medical services for psychological distress (3.5% compared with 5.8%, P = 0.02). When level of psychological distress was controlled, Vietnamese and Filipino immigrants were one-third as likely as Canadian-born residents to make use of mental health services. The lower rate of use by immigrants could not be explained by differences in sociodemographics, somatic or psychological symptoms, length of stay in Canada, or use of alternative sources of help. CONCLUSION: Immigrant status is associated with lower rates of use of mental health services, even with universal health insurance. This lower rate of use likely reflects cultural and linguistic barriers to care. 相似文献
98.
Treatment of congenital cystic adenomatoid malformation-does resection in the early postnatal period increase surgical risk? 总被引:1,自引:0,他引:1
Young Tae Kim Jun Sung Kim June Dong Park Chang Hyun Kang Sook Whan Sung Joo Hyun Kim 《European journal of cardio-thoracic surgery》2005,27(4):658-661
OBJECTIVE: The recent development of fetal ultrasonography has allowed for an increasing number of prenatal diagnoses for congenital cystic adenomatoid malformation (CCAM). However, the appropriate surgical timing of these patients has not been studied as of yet. The aim of this study is to suggest a safe strategy for the treatment of CCAM by identifying the relationship between the timing of surgery and postoperative outcome. METHODS: Between 1987 and 2003, 40 patients (28 males, 12 females) underwent surgical resection for CCAM. The mean age was 38.6+/-9.1 (2 days-13 years) months. CCAM was diagnosed by prenatal ultrasonography in eight patients. Early operations were performed in four out of the eight. Operation was deferred until 2-12 months of age for the remaining four patients. RESULTS: Type I CCAM was found in 20 patients, type II in 20 and no patient exhibited type III. Five patients had associated pectus excavatum anomaly. There were no cases of operative mortality. Seventeen minor postoperative complications developed in 16 patients (40.0%): prolonged chest tube drain in 10, wound infection in 4, and 1 case of pneumonia, empyema and pleural space, respectively. The average hospital stay was 11.8 (6-29) days. During the mean follow-up period of 67.5 months, one patient died of accidental aspiration 7 months after operation during the postoperative recovery course of Ravich operation for pectus excavatum. The remaining patients reported doing well with normal physical activity. All five patients who underwent surgery at the age of under 1 month did not exhibit increased postoperative morbidity. CONCLUSIONS: We concluded that surgery for CCAM could be safely performed in all age groups with satisfactory long-term outcomes. It is suggested that early elective surgical correction can be recommended for a patient whose diagnosis was made in utero. 相似文献
99.
Guk-Hee Suh Hyun Gyun Son Young-Su Ju Kyeong Hyeong Jcho Byeong Kil Yeon Young Min Shin Baik Seok Kee Sung-Ku Choi 《The American journal of geriatric psychiatry》2004,12(5):509-516
OBJECTIVE: Behavioral disturbances in dementia are extremely prominent and distressful, and often result in serious physical, social, and economic consequences. The authors compared the efficacy and tolerability of risperidone and haloperidol in the treatment of behavioral and psychological symptoms of dementia (BPSD) in institutionalized elderly Korean patients with Alzheimer disease, vascular dementia, or mixed dementia. METHODS: This was an 18-week double-blind, crossover study involving 120 patients who were randomly assigned to receive flexible doses (0.5-1.5 mg/day) of risperidone or haloperidol. BPSD were assessed using the Korean version of the Behavioral Pathology in Alzheimer's Disease Rating Scale (BEHAVE-AD-K), the Korean version of the Cohen-Mansfield Agitation Inventory (CMAI-K), and the Clinical Global Impression of Change scale (CGI-C). Safety and tolerability assessments included the Extrapyramidal Symptom Rating Scale and the incidence of adverse events. RESULTS: Both risperidone and haloperidol were efficacious in alleviating BPSD. However, when receiving risperidone, patients showed significantly greater improvement than when receiving haloperidol in the total and subscale scores of the BEHAVE-AD-K, the total and subscale scores of the CMAI-K, and the scores on the CGI-C scale. Also, risperidone had an additional benefit on aggressiveness and anxieties/phobias. The risk of antipsychotic-induced parkinsonism throughout this study was significantly lower with risperidone than with haloperidol. CONCLUSION: Risperidone had a favorable efficacy and tolerability profile compared with haloperidol in the treatment of BPSD in this patient population. 相似文献
100.
J M G Crane T Delaney K D Butt K A Bennett D Hutchens D C Young 《The journal of maternal-fetal & neonatal medicine》2004,15(5):319-323
OBJECTIVE: To identify independent predictors of successful labor induction with oral or vaginal misoprostol. METHODS: Women enrolled in four previous randomized trials involving oral or vaginal misoprostol for cervical ripening and labor induction were included in the present cohort study, with dosing of 25-50 microg every 4 to 6 h vaginally (n = 574) or 50 microg every 4 h orally (n = 207). Multiple logistic regression was performed to identify factors independently associated with successful labor induction -- defined as vaginal delivery within 12 h, vaginal delivery within 24 h and spontaneous vaginal delivery. Predictors of Cesarean birth and the need for only one dose of misoprostol were also identified. Variables included in the models were maternal age, weight, height, parity, gravidity, membrane status, route of misoprostol, gestational age, birth weight, and Bishop score and its individual components. RESULTS: Maternal age, height, weight, parity, birth weight, dilatation, effacement and cervical station were associated with vaginal delivery within 24 h of induction. Maternal age, height, weight, nulliparity, birth weight and route of misoprostol were associated with Cesarean birth, with oral misoprostol being associated with a lower rate of Cesarean birth. The need for only one dose of misoprostol was predicted by maternal height, weight, parity, gestational age, Bishop score and route of misoprostol. CONCLUSION: Characteristics of the woman (height, weight, parity), the fetus (birth weight) and some of the individual components of the Bishop score, were associated with successful labor induction, with oral misoprostol being associated with a lower rate of Cesarean birth. 相似文献