全文获取类型
收费全文 | 28880篇 |
免费 | 1871篇 |
国内免费 | 91篇 |
专业分类
耳鼻咽喉 | 436篇 |
儿科学 | 1317篇 |
妇产科学 | 729篇 |
基础医学 | 3035篇 |
口腔科学 | 507篇 |
临床医学 | 2634篇 |
内科学 | 6620篇 |
皮肤病学 | 526篇 |
神经病学 | 1953篇 |
特种医学 | 986篇 |
外科学 | 4522篇 |
综合类 | 521篇 |
一般理论 | 4篇 |
预防医学 | 1846篇 |
眼科学 | 1022篇 |
药学 | 2100篇 |
1篇 | |
中国医学 | 112篇 |
肿瘤学 | 1971篇 |
出版年
2023年 | 260篇 |
2022年 | 544篇 |
2021年 | 1129篇 |
2020年 | 651篇 |
2019年 | 863篇 |
2018年 | 999篇 |
2017年 | 706篇 |
2016年 | 772篇 |
2015年 | 825篇 |
2014年 | 1148篇 |
2013年 | 1486篇 |
2012年 | 2208篇 |
2011年 | 2083篇 |
2010年 | 1260篇 |
2009年 | 1030篇 |
2008年 | 1564篇 |
2007年 | 1518篇 |
2006年 | 1429篇 |
2005年 | 1353篇 |
2004年 | 1187篇 |
2003年 | 1018篇 |
2002年 | 935篇 |
2001年 | 523篇 |
2000年 | 543篇 |
1999年 | 439篇 |
1998年 | 230篇 |
1997年 | 180篇 |
1996年 | 152篇 |
1995年 | 148篇 |
1994年 | 137篇 |
1993年 | 103篇 |
1992年 | 294篇 |
1991年 | 263篇 |
1990年 | 232篇 |
1989年 | 225篇 |
1988年 | 190篇 |
1987年 | 185篇 |
1986年 | 161篇 |
1985年 | 176篇 |
1984年 | 162篇 |
1983年 | 153篇 |
1982年 | 84篇 |
1981年 | 81篇 |
1980年 | 70篇 |
1979年 | 121篇 |
1978年 | 97篇 |
1974年 | 77篇 |
1973年 | 114篇 |
1972年 | 105篇 |
1971年 | 71篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
31.
The aim of this article is to provide clinicians and researchers a comprehensive overview of the development and functions of gesture in childhood and in select populations with developmental language impairments. Of significance is the growing body of evidence that gesture enhances, not hinders, language development. In both normal and impaired populations, gesture and language development parallel each other and share underlying symbolic abilities. Gesture serves several functions, including those of communication, compensation, and transition to spoken language. In clinical practice, gesture may play a valuable role in diagnosis, prognosis, goal selection, and intervention for children with language impairments. Where available, supporting evidence is presented. Needs for additional research on gesture are also highlighted. 相似文献
32.
33.
Childhood poverty is common in Canada: 1,114,000 children under 16 years of age live below the poverty line. The incidence is highest among children of single mothers, unemployed parents, Canadian native peoples and recent immigrants, particularly refugees. Compared with the national average, the infant mortality rate is twice as high, deaths from infectious diseases are 2.5 times more common and accidental deaths are twice as common among children of low-income families. Other problems associated with poverty are iron deficiency anemia, dental caries, chronic ear infections, mental retardation, learning disabilities, poor school performance and increased suicide rates. Health care professionals can help address the poor physical and mental health associated with poverty in children by promoting a broad range of public policies. 相似文献
34.
35.
Phospho-akt expression is associated with a favorable outcome in non-small cell lung cancer. 总被引:3,自引:0,他引:3
Amit Shah William A Swain Donna Richardson John Edwards Duncan J Stewart Catherine M Richardson Daniel E B Swinson Dipika Patel J Louise Jones Kenneth J O'Byrne 《Clinical cancer research》2005,11(8):2930-2936
Akt, a Serine/Threonine protein kinase, mediates growth factor-associated cell survival. Constitutive activation of Akt (phosphorylated Akt, P-Akt) has been observed in several human cancers, including lung cancer and may be associated with poor prognosis and chemotherapy and radiotherapy resistance. The clinical relevance of P-Akt in non-small cell lung cancer (NSCLC) is not well described. In the present study, we examined 82 surgically resected snap-frozen and paraffin-embedded stage I to IIIA NSCLC samples for P-Akt and Akt by Western blotting and for P-Akt by immunohistochemistry. P-Akt protein levels above the median, measured using reproducible semiquantitative band densitometry, correlated with a favorable outcome (P = 0.007). Multivariate analysis identified P-Akt as a significant independent favorable prognostic factor (P = 0.004). Although associated with a favorable prognosis, high P-Akt levels correlated with high tumor grade (P = 0.02). Adenocarcinomas were associated with low P-Akt levels (P = 0.039). Akt was not associated with either outcome or clinicopathologic variables.Cytoplasmic (CP-Akt) and nuclear (NP-Akt) P-Akt tumor cell staining was detected in 96% and 42% of cases, respectively. Both CP-Akt and NP-Akt correlated with well-differentiated tumors (P = 0.008 and 0.017, respectively). NP-Akt also correlated with nodal metastases (P = 0.022) and squamous histology (P = 0.037).These results suggest P-Akt expression is a favorable prognostic factor in NSCLC. Immunolocalization of P-Akt, however, may be relevant as NP-Akt was associated with nodal metastases, a known poor prognostic feature in this disease. P-Akt may be a potential novel therapeutic target for the management of NSCLC. 相似文献
36.
We present the findings of clean intermittent self-catheterisation (CISC) as a long term method of bladder management for 36 quadriplegic spinal cord injured patients, primarily at C6/C7 level, who were taught CISC between 1983 and 1987. Success in CISC was assessed by a mail survey, a telephone interview, and current sterile urine status. Twenty nine (81%) of 36 patients continued to use CISC after a mean discharge period of 2.9 years (p less than 0.001) with high levels of acceptance. Rao's V discriminant analysis showed success in CISC was affected by the interval between injury and initial self-catheterisation (Canonical Correlation Co-efficient = 1.34). Results of urinalysis for patients continuing CISC were obtained for 18 (62%) patients, 16 (88%) of whom had sterile urine. Implications of these and other findings along with reasons for cessation of CISC are discussed. 相似文献
37.
Bela Prajapaty Bharat Shah 《Indian journal of otolaryngology and head and neck surgery》1997,49(4):391-393
The pyriform sinus fistula is rare congenital anomaly of either third or fourth branchial pouch, which most frequently presented itself by recurrent episodes of neck abscess for long time. Majority of patients with this anomaly presented with symptoms before 10 years and it is more common than has previously been commonly found on leftside (93%). Clinically high index of suspicion, cannulation of the tract under general anaesthesia, Direct laryngoscopy and fistulogram have freequently been successful in identifying the presence of these embryological remnants. Surgical exploration of sinus tract with its total excision, guided with cannula inside its lumen is the definitive treatment. 相似文献
38.
39.
40.
Hans-Jürgen Möller Horst Müller Richard L. Borison Nina R. Schooler Guy Chouinard 《European archives of psychiatry and clinical neuroscience》1995,245(1):45-49
The hypothesis that differences in drug effects of risperidone and haloperidol on negative symptoms in schizophrenia are secondary to effects on positive, extrapyramidal, and depressive symptoms was investigated by means of an analysis of the data from the USA-Canada risperidone double-blind randomized clinical trial of 523 chronic schizophrenic patients. Regression analyses in the total sample and within treatment groups confirmed a strong relationship between changes in negative symptoms and the other variables studied (R2=0.50–0.51,p<0.001). Only depressive symptoms did not contribute significantly to these results (p>0.10). Path analysis showed that the greater mean change (p<0.05) of negative symptoms with risperidone compared to haloperidol could not be fully explained by correlations with favourable effects on positive and extrapyramidal symptoms. The relationship between shift in extrapyramidal symptoms and shift in negative symptoms failed to reach statistical significance; however, there was a clear tendency in the expected direction in both treatment groups. 相似文献