全文获取类型
收费全文 | 11138篇 |
免费 | 584篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 181篇 |
儿科学 | 152篇 |
妇产科学 | 88篇 |
基础医学 | 1465篇 |
口腔科学 | 321篇 |
临床医学 | 620篇 |
内科学 | 2788篇 |
皮肤病学 | 251篇 |
神经病学 | 845篇 |
特种医学 | 531篇 |
外科学 | 2078篇 |
综合类 | 66篇 |
一般理论 | 1篇 |
预防医学 | 335篇 |
眼科学 | 98篇 |
药学 | 611篇 |
中国医学 | 23篇 |
肿瘤学 | 1344篇 |
出版年
2023年 | 101篇 |
2022年 | 174篇 |
2021年 | 347篇 |
2020年 | 155篇 |
2019年 | 240篇 |
2018年 | 305篇 |
2017年 | 236篇 |
2016年 | 316篇 |
2015年 | 311篇 |
2014年 | 379篇 |
2013年 | 414篇 |
2012年 | 658篇 |
2011年 | 762篇 |
2010年 | 426篇 |
2009年 | 405篇 |
2008年 | 633篇 |
2007年 | 721篇 |
2006年 | 671篇 |
2005年 | 687篇 |
2004年 | 623篇 |
2003年 | 586篇 |
2002年 | 591篇 |
2001年 | 188篇 |
2000年 | 167篇 |
1999年 | 187篇 |
1998年 | 136篇 |
1997年 | 147篇 |
1996年 | 91篇 |
1995年 | 99篇 |
1994年 | 54篇 |
1993年 | 69篇 |
1992年 | 88篇 |
1991年 | 90篇 |
1990年 | 88篇 |
1989年 | 69篇 |
1988年 | 73篇 |
1987年 | 71篇 |
1986年 | 58篇 |
1985年 | 56篇 |
1984年 | 35篇 |
1983年 | 30篇 |
1982年 | 18篇 |
1980年 | 14篇 |
1979年 | 29篇 |
1978年 | 31篇 |
1977年 | 14篇 |
1974年 | 19篇 |
1970年 | 12篇 |
1968年 | 14篇 |
1967年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
K Takeuchi K Matsubayashi S Kimura A Kawamoto T Ozawa K Shimada 《Nihon Ronen Igakkai zasshi. Japanese journal of geriatrics》1992,29(7-8):549-553
Lacunes on brain MRI, causal blood pressure, 24-hour ambulatory blood pressure and common carotid blood flow measured by the doppler method were studied in 31 elderly patients with Parkinson's disease (mean age 67.5 +/- 7.3 years). Nineteen patients with Parkinson's disease (61%) had at least one lacune. Patients with lacunes (P(+)) were significantly higher in age than patients without lacune (P(-)). The difference of casual blood pressure between patients in the two groups was not significant. On the other hand, the average of ambulatory blood pressure measurements during a 24-hour period was significantly higher in the P(+) group than in the P(-) group. The average of carotid blood flow was also significantly lower in the P(+) group than in the P(-) group, however, after adjustment for age, the difference between them became insignificant. In conclusion, the incidence of silent lacunes on brain MRI was fairly common in elderly patients with Parkinson's disease. A high average 24-hour ambulatory blood pressure was suggested to be one of the risk factors of lacunar stroke in elderly cases of Parkinson's disease. The concept of "combine type" in Parkinsonism was supposed to be suitable as well as in senile dementia of Alzheimer type. 相似文献
32.
K Matsubayashi S Kimura T Iwasaki K Okumiya T Hamada M Fujisawa K Takeuchi T Kawamoto T Ozawa 《Nihon Ronen Igakkai zasshi. Japanese journal of geriatrics》1992,29(11):823-828
Visual analogue scale of happiness (VAS-H) was applied to elderly Himalayan highlanders to investigate the influence of life-style and socio-cultural background on subjective happiness. The score of "VAS-H" and neuropsychological function tests in 733 Himalayan highlanders who belonged to 5 separate villages were compared with those in 313 Japanese elderly subjects. The places of study consisted of 4 villages (Khalimabad; K, Gulmit; G, Pasu; P, Shimshal; S) in Hunza area in Pakistan, and Namche Bazar; N in Nepal. Degree of modern civilization was highest in K, followed by N, G, P and lowest was that in S by historical and sociological aspects. The mean VAS-H sore in Himalayan highlanders and the degree of modern civilization in the area was in inverse proportion. Himalayan elderly women showed a significant lower score on VAS-H compared with elderly Himalayan men or elderly Japanese subjects. The VAS-H score in the Japanese elderly correlated significantly with the stability of posture and walk, and that of Himalayan highlanders correlated significantly with manual skill. In conclusion, the life style or socio-cultural background strongly affected subjective happiness in the elderly. The VAS-H was useful in comparing subjective happiness in different cultures. 相似文献
33.
Incidental brain lesions on magnetic resonance imaging and neurobehavioral functions in the apparently healthy elderly. 总被引:9,自引:0,他引:9
K Matsubayashi K Shimada A Kawamoto T Ozawa 《Stroke; a journal of cerebral circulation》1992,23(2):175-180
BACKGROUND AND PURPOSE: Controversies exist whether incidental neuroradiological brain lesions in the elderly are associated with depressed neuropsychological function. To address this important issue in a cross-sectional study, we related brain lesions on magnetic resonance imaging to a variety of cognitive and neurobehavioral function tests in an independent, normal elderly population. METHODS: We studied 73 independent asymptomatic elderly individuals (mean +/- SD age 70 +/- 6 years) to determine the relations between degree of brain atrophy, location and number of "lacunes," and grade of periventricular hyperintense lesions with a variety of cognitive and neurobehavioral function scores. RESULTS: We found that severity of neuroradiological changes increased while neuropsychological function scores declined with age. After adjustment for the effect of age, advanced periventricular hyperintensities, but not brain atrophy or patchy "lacunar" lesions, were associated with declines in all neuropsychological functions tested. CONCLUSION: We conclude that incidental advanced periventricular diffuse or patchy white matter changes may play a role in the development of cognitive and neurobehavioral impairments in apparently normal elderly persons. 相似文献
34.
Gao HZ Kobayashi K Tabata A Tsuge H Iijima M Yasuda T Kalkanoglu HS Dursun A Tokatli A Coskun T Trefz FK Skladal D Mandel H Seidel J Kodama S Shirane S Ichida T Makino S Yoshino M Kang JH Mizuguchi M Barshop BA Fuchinoue S Seneca S Zeesman S Knerr I Rodés M Wasant P Yoshida I De Meirleir L Abdul Jalil M Begum L Horiuchi M Katunuma N Nakagawa S Saheki T 《Human mutation》2003,22(1):24-34
Classical citrullinemia (CTLN1), a rare autosomal recessive disorder, is caused by mutations of the argininosuccinate synthetase (ASS) gene, localized on chromosome 9q34.1. ASS functions as a rate-limiting enzyme in the urea cycle. Previously, we identified 32 mutations in the ASS gene of CTLN1 patients mainly in Japan and the United States, and to date 34 different mutations have been described in 50 families worldwide. In the present study, we report ASS mutations detected in 35 additional CTLN1 families from 11 countries. By analyzing the entire coding sequence and the intron-exon boundaries of the ASS gene using RT-PCR and/or genomic DNA-PCR, we have identified 16 novel mutations (two different 1-bp deletions, a 67-bp insertion, and 13 missense) and have detected 12 known mutations. Altogether, 50 different mutations (seven deletion, three splice site, one duplication, two nonsense, and 37 missense) in 85 CTLN1 families were identified. On the basis of primary sequence comparisons with the crystal structure of E. coli ASS protein, it may be concluded that any of the 37 missense mutations found at 30 different positions led to structural and functional impairments of the human ASS protein. It has been found that three mutations are particularly frequent: IVS6-2A>G in 23 families (Japan: 20 and Korea: three), G390R in 18 families (Turkey: six, U.S.: five, Spain: three, Israel: one, Austria: one, Canada: one, and Bolivia: one), and R304W in 10 families (Japan: nine and Turkey: one). Most mutations of the ASS gene are "private" and are distributed throughout the gene, except for exons 5 and 12-14. It seems that the clinical course of the patients with truncated mutations or the G390R mutation is early-onset/severe. The phenotype of the patients with certain missense mutations (G362V or W179R) is more late-onset/mild. Eight patients with R86H, A118T, R265H, or K310R mutations were adult/late-onset and four of them showed severe symptoms during pregnancy or postpartum. However, it is still difficult to prove the genotype-phenotype correlation, because many patients were compound heterozygotes (with two different mutations), lived in different environments at the time of diagnosis, and/or had several treatment regimes or various knowledge of the disease. 相似文献
35.
36.
37.
Development of a high-level expression system for deuterium-labeled human serum albumin 总被引:1,自引:0,他引:1
Tomida M Kimura M Kuwata K Hayashi T Okano Y Era S 《The Japanese journal of physiology》2003,53(1):65-69
We have developed an expression system for recombinant human serum albumin (rHSA) using methylotrophic yeast Pichia pastoris Mut(+) transformants together with the multiple cross-over integration of the vector containing human serum albumin (HSA). After 86 h of methanol induction, the secreted rHSA reached levels of approximately 320 mg/l in 100% H(2)O medium and approximately 180 mg/l in 70% D(2)O/30% H(2)O (v/v) medium in a fed-batch fermenter. The structures of the obtained rHSA and plasma-derived HSA (pHSA) were virtually identical as viewed from various physicochemical techniques such as HPLC, SDS gel electrophoresis, and CD. NMR peaks of the partially deuterium (D)-labeled rHSA (DrHSA) were quite sharp compared to those of pHSA due to suppression of the intramolecular nuclear Overhauser effect, promising further structural studies of the whole HSA molecule in the solution state using the recent NMR techniques. 相似文献
38.
CD44 variant 6 in endometrioid carcinoma of the uterus: its expression in the adenocarcinoma component is an independent prognostic marker 总被引:10,自引:0,他引:10
Hoshimoto K Yamauchi N Takazawa Y Onda T Taketani Y Fukayama M 《Pathology, research and practice》2003,199(2):71-77
The expression of variant isoforms of CD44 (CD44v) correlates with the metastatic potential of various carcinomas. In endometrial cancer, however, the significance of CD44v-expression as a prognostic indicator has not been fully investigated, nor has it been compared with that of p53, estrogen receptor or Ki67. Surgical material consisted of 14 atypical endometrial hyperplasias (AEH) and 163 endometrial carcinomas (EC). Expression of CD44s, v3 and v6 in carcinoma tissue, and other prognostic markers were immunohistochemically evaluated. The expression in the squamous differentiation was strictly excluded for the evaluation of immunohistochemistry, because the significance was different from that in the adenocarcinoma component. CD44s was frequently expressed in AEH and EC. On the other hand, CD44v3- and v6-positivities were rare or nonexistent in AEH, but were observed in 8 and 35% of EC, respectively. CD44v3-expression correlated significantly with histologic grade and lymph node metastasis. However, there was no correlation between CD44v6 expression and any clinicopathologic factor, nor were other prognostic markers expressed. Univariate analysis revealed that each CD44 was a prognostic determinant in the patients with EC. However, employing multivariate analysis, there were only three independent factors: p53 overexpression, CD44v6 expression and myometrial invasion. CD44v6 expression in the adenocarcinoma component may directly affect the behavior of carcinoma and the prognosis of patients with EC. 相似文献
39.
Namiki T Yanagawa S Izumo T Ishikawa M Tachibana M Kawakami Y Yokozeki H Nishioka K Kaneko Y 《Cancer Genetics and Cytogenetics》2005,157(1):1-11
To clarify the correlation of genomic alterations with clinical and histological features, we performed metaphase comparative genomic hybridization analysis on 20 primary cutaneous melanomas, which were obtained by laser capture or manual microdissection, and 16 melanoma cell lines. There were no differences in the average number of aberrations between acral melanomas (AM) and non-AM, although gains of 5q and 11q13 were more frequent (P=0.05) and 10q loss was less frequent (P=0.01) in AM than in non-AM. Although tumor thickness is considered a measurable estimate of clinical expression, there were no differences in the average number of aberrations among 4 groups, classified by thickness of the tumor. While the majority of aberrations were equally distributed among the 4 groups, 6p gains were found only in the thickest tumors. Patients with 6p or 1q gains had a lower overall survival rate than those without them (P=0.0002 or P=0.013). While gains of 1q, 2q, 3p, 3q, 7q, 20p, and 20q were more frequent in the cell lines than in the primary tumors (P<0.01), losses of 6q, 9p, 10p, and 10q were equally found in both cell lines and primary tumors. The present study showed that chromosomal aberrations had already occurred in the thinner tumors, and that 6p and 1q gains may be a prognostic factor. 相似文献
40.
Takahiro Tsujimura Masashi Takeda Nobuyuki Terada Hiroshi Uramoto 《Pathology international》1991,41(8):642-646
Two cases of peritoneal papillary carcinoma are reported. The patient in the first case was a 71-year-old woman with symptoms of obstructive ileus. Laparotomy revealed a tumor in the omentum involving the transverse colon, and several small tumors in the peritoneum and pelvic wall. However, no primary site of the tumor was seen in the ovary, pancreas, or gastrointestinal tract. The patient in the second case was a 44-year-old woman with carcinomatous peritonitis. Postmortem examination revealed multiple tumors in the peritoneum, omentum, and pelvic wall. Tumors were also found in the cortex with mild invasion of the underlying parenchyma of the bilateral ovaries, although these lesions were thought to be metastatic. The histologic features of the tumor in both cases were those of tubulopapillary adenocarcinoma containing scattered psammoma bodies. The cells were positive with the PAS D technique, but negative with alcian blue staining. In both cases, the serum levels of CA-125 were considerably elevated, and the tumor cells showed positivity for CA-125, S 100 protein, cytokeratin and EMA by im-munohistochemistry. The present cases were most likely peritoneal serous papillary adenocarcinoma derived from extraovarian peritoneal mesothelium with miillerian potential, being different from the usual type of diffuse malignant mesothelioma. Acta Pathol Jpn 41: 642-646, 1991. 相似文献