全文获取类型
收费全文 | 527078篇 |
免费 | 57572篇 |
国内免费 | 7170篇 |
专业分类
耳鼻咽喉 | 7942篇 |
儿科学 | 11439篇 |
妇产科学 | 13166篇 |
基础医学 | 61448篇 |
口腔科学 | 17667篇 |
临床医学 | 61687篇 |
内科学 | 110363篇 |
皮肤病学 | 12369篇 |
神经病学 | 41439篇 |
特种医学 | 19621篇 |
外国民族医学 | 116篇 |
外科学 | 83953篇 |
综合类 | 18879篇 |
现状与发展 | 56篇 |
一般理论 | 78篇 |
预防医学 | 34027篇 |
眼科学 | 12775篇 |
药学 | 37878篇 |
54篇 | |
中国医学 | 5237篇 |
肿瘤学 | 41626篇 |
出版年
2023年 | 6337篇 |
2022年 | 4248篇 |
2021年 | 7947篇 |
2020年 | 8732篇 |
2019年 | 6390篇 |
2018年 | 12927篇 |
2017年 | 12169篇 |
2016年 | 12775篇 |
2015年 | 14017篇 |
2014年 | 18622篇 |
2013年 | 21981篇 |
2012年 | 17531篇 |
2011年 | 17733篇 |
2010年 | 15545篇 |
2009年 | 16946篇 |
2008年 | 15730篇 |
2007年 | 15570篇 |
2006年 | 16424篇 |
2005年 | 13857篇 |
2004年 | 12220篇 |
2003年 | 11504篇 |
2002年 | 10928篇 |
2001年 | 31347篇 |
2000年 | 31171篇 |
1999年 | 26506篇 |
1998年 | 7879篇 |
1997年 | 6826篇 |
1996年 | 6321篇 |
1995年 | 5617篇 |
1994年 | 4596篇 |
1993年 | 4006篇 |
1992年 | 17156篇 |
1991年 | 15752篇 |
1990年 | 14954篇 |
1989年 | 14720篇 |
1988年 | 13277篇 |
1987年 | 12613篇 |
1986年 | 11585篇 |
1985年 | 10715篇 |
1984年 | 7236篇 |
1983年 | 5956篇 |
1982年 | 2982篇 |
1979年 | 5586篇 |
1978年 | 3495篇 |
1977年 | 3103篇 |
1975年 | 2723篇 |
1974年 | 3164篇 |
1973年 | 2942篇 |
1972年 | 2928篇 |
1971年 | 2839篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
Intracranial pathology is a common and important complication in extremely low birth weight babies. Lenticulostriate vasculopathy (LSV) is an abnormal finding on cranial ultrasounds of sick babies and has been associated with congenital infection, chromosomal aberration and twin-to-twin transfusion. We describe a previously unreported situation of LSV being detected in both donor and recipient twin. This pair of monochorionic, diamniotic twins was admitted to the Neonatal Intensive Care Unit at 28 weeks of gestation. The mother underwent an emergency caesarean section because ultrasound and Doppler studies showed stage III twin-to-twin transfusion syndrome. The first twin weighed 998 g and second twin weighed 600 g. The first twin had an uneventful stay, whereas the second twin needed prolonged continuous positive airway pressure and indomethacin for patent ductus arteriosus. Both of them developed LSV. The clinical significance of this condition on the neuro-developmental outcome of a neonate has not yet been fully determined. 相似文献
92.
Y. Graif A. Goldberg R. Tamir D. Vigiser S. Melamed 《Clinical and experimental allergy》2006,36(12):1532-1537
BACKGROUND: In allergic conditions, the degree of skin test reactivity does not always correlate with the severity of clinical symptoms. Additional factors may contribute to the reported symptom severity. OBJECTIVES: To investigate the association between the magnitude of the skin prick test (SPT) response and the reported symptom severity in patients with allergic rhinitis and the possible modifying role of psychological factors. METHODS: One hundred four patients with allergic rhinitis and 23 with non-allergic rhinitis, classified according to their SPT response to 19 aeroallergens, were asked to rate the severity of five symptoms and to indicate whether their symptoms intensified on exposure to five common aeroallergens. They also completed a psychological questionnaire. Results Reported symptom severity of allergic rhinitis did not correlate with weal size for any of the aeroallergens tested or with the number of positive responses on SPT. It was not related to patient age, sex, or education. The reported symptoms severity correlated positively (0.29, P < 0.01) with reported symptom intensification on exposure to allergens. Moreover, both outcomes were positively associated with the psychological factors of hypochondriasis (0.20, P < 0.05 and 0.18, P < 0.05, respectively), and somatic awareness (0.24, P < 0.05 and 0.33, P < 0.01, respectively), but not with neuroticism. CONCLUSIONS: The severity of symptoms experienced by patients with allergic rhinitis is apparently not related to the magnitude of SPT response, but rather to psychological factors of hypochondriasis and somatic awareness. Physicians should be aware of the contribution of psychological factors to patient perceptions of the intensity of symptoms and of the intensification of symptoms on their exposure to allergens. 相似文献
93.
94.
Directors of nursing at 23 nursing homes with Alzheimer's units in Southwestern Pennsylvania completed a self‐reported survey of 12 questions. Responses from the self‐administered questionnaires (100% response rate) revealed a wide variation in the staff categories assessing the oral health status of newly admitted residents with AD. The respondents described oral examinations that were incomplete when compared to the oral indicators listed in the Minimum Data Set. All nursing homes reported that oral hygiene was provided each day. The number of residents in a facility had a significant effect on the frequency of oral hygiene provided. Only 52% of the facilities reported yearly oral examinations for this population. According to the respondents, dental treatment was typically performed on‐site. The oral health care costs were paid by Medicare, Medicaid, the residents/family members, or by other undescribed resources. Insufficient time, staff, and training, as well as uncooperative behavior, were identified as barriers to optimum oral health care for residents with AD. Additional staff, specialized training, and increased government reimbursement were suggested to improve the oral health care for this group of older adults. For future studies, review of medical records and on‐site evaluation of the oral health care at these facilities should be required to verify the reported practices. 相似文献
95.
96.
97.
Weaver mutant mice are characterized by a decrease in striatal dopamine (DA), which is associated with a progressive loss of DA neurones in the substantia nigra. This mutant thus provides the opportunity to examine the functional effects of DA neurones grafted to the striatum in a genetic model of parkinsonism. Ventral mesencephalic tissue from normal foetuses was placed on the surface of the right dorsal striatum of adult weaver mutants. After grafting, animals were tested for methamphetamine-induced circling behaviour. Mutants with DA containing grafts displayed a significant circling bias toward the left, non-grafted side. Mutants without grafts did not display any rotational bias to either side. These results demonstrate that grafted DA containing neurones establish a functional innervation of the weaver striatum and suggest that grafting of neural tissue is a viable approach in restoring function in genetic degenerative disorders of the nigrostriatal system. 相似文献
98.
S Kawata S Noda Y Imai S Tamura R Saitoh S Miyoshi Y Minami S Tarui 《Gastroenterologia Japonica》1987,22(1):55-62
The pharmacokinetics of 1-(tetrahydro-2-furanyl)-5-fluorouracil (FT) and its conversion into 5-fluorouracil (FUra) in liver tissue were studied in ten patients with hepatocellular carcinoma (HCC). The plasma concentration of FT after its intravenous injection (dosage: 800 mg) was computerfitted to a bi-exponential function (C = Ae-alpha t + Be-beta t), indicating a two-compartment disposition. The pharmacokinetic parameters did not significantly differ between the five patients with, and the five without cirrhosis of the liver. The plasma concentrations of FUra likewise showed no significant difference between the two groups. The rates of FT degradation in the liver tissue homogenate were similar for four of the patients with cirrhosis (0.10 +/- 0.05 mumol/g liver protein/30 min) and four of those without it (0.13 +/- 0.05). The rates of cytochrome P-450-dependent FUra formation in the microsomal fraction of liver tissue from two patients (1.1 and 1.3 nmol/mg microsomal protein/30 min) were dramatically reduced to less than half of those of two control subjects (2.4 and 2.7). The estimated rates of FUra formation in the soluble fraction (105,000 X g supernatant fraction) from the two patients (0.1 and 0.13 nmol/mg protein/30 min) were almost identical to those from the controls (0.12 and 0.14), suggesting that the rate in the soluble fraction from HCC patients may not be as strongly affected as the rate in the microsomal fraction.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
99.
100.
A case of Ullrich disease was presented. The patient was a 3-year-old girl with torticollis, generalized muscle weakness and acroatonia since birth. High-arched palate, protruded calcaneus, and mild contracture of proximal joints were also recognized. Intellectual development was normal. Serum level of CPK was slightly increased. In histological and histochemical examinations of quadriceps femoris muscle, proliferated connective tissue, marked variation in the muscle fiber diameter, and a lot of degenerated and regenerated fibers were recognized. Minimal injury easily causes subcutaneous hemorrhage, but no abnormality was found in the structure of collagen. 相似文献