全文获取类型
收费全文 | 920篇 |
免费 | 115篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 88篇 |
妇产科学 | 12篇 |
基础医学 | 48篇 |
口腔科学 | 20篇 |
临床医学 | 51篇 |
内科学 | 239篇 |
皮肤病学 | 3篇 |
神经病学 | 9篇 |
特种医学 | 127篇 |
外科学 | 185篇 |
综合类 | 99篇 |
预防医学 | 80篇 |
眼科学 | 28篇 |
药学 | 35篇 |
肿瘤学 | 9篇 |
出版年
2021年 | 14篇 |
2020年 | 7篇 |
2019年 | 11篇 |
2018年 | 17篇 |
2017年 | 8篇 |
2016年 | 14篇 |
2015年 | 17篇 |
2014年 | 22篇 |
2013年 | 26篇 |
2012年 | 27篇 |
2011年 | 44篇 |
2010年 | 24篇 |
2009年 | 21篇 |
2008年 | 30篇 |
2007年 | 42篇 |
2006年 | 42篇 |
2005年 | 49篇 |
2004年 | 33篇 |
2003年 | 36篇 |
2002年 | 32篇 |
2001年 | 36篇 |
2000年 | 34篇 |
1999年 | 39篇 |
1998年 | 14篇 |
1997年 | 30篇 |
1996年 | 16篇 |
1995年 | 15篇 |
1994年 | 9篇 |
1992年 | 11篇 |
1991年 | 18篇 |
1990年 | 19篇 |
1989年 | 15篇 |
1988年 | 10篇 |
1987年 | 13篇 |
1986年 | 18篇 |
1985年 | 13篇 |
1984年 | 9篇 |
1982年 | 7篇 |
1980年 | 13篇 |
1979年 | 24篇 |
1978年 | 19篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 11篇 |
1974年 | 14篇 |
1973年 | 18篇 |
1972年 | 13篇 |
1970年 | 9篇 |
1969年 | 8篇 |
1967年 | 9篇 |
排序方式: 共有1035条查询结果,搜索用时 0 毫秒
1.
2.
3.
Regnier V; Meddeb M; Lecointre G; Richard F; Duverger A; Nguyen VC; Dutrillaux B; Bernheim A; Danglot G 《Human molecular genetics》1997,6(1):9-16
Type 1 neurofibromatosis (NF1) gene encodes for a member of the GTPase
activating protein family and is considered to be a tumor suppressor gene.
Its very high rate of de novo mutation in humans led us to study a specific
feature of this gene: the presence of numerous NF1-related sequences.
According to our results, the human genome contains at least 11 NF1-related
sequences, nine of which are scattered near centromeric sequences of seven
different chromosomes. These NF1-related sequences, whose extent is quite
varied according to loci, are unprocessed copies of the NF1 gene, and bear
numerous mutations. A phylogenetic analysis of the six largest sequences
indicates that they are all derived from a common ancestor, which would
have appeared 22-33 million years ago, and was subsequently duplicated
several times during hominoid evolution. The most recent duplication and
interchromosomal transposition occurred in the last million years
suggesting that the process could still be ongoing. Intriguing similarities
between the evolution of alpha- satellite DNA and NF1-related sequences
suggest the involvement of a common genetic mechanism for the generation
and pericentric spreading of these NF1 partial copies.
相似文献
4.
Mass media campaign--A Su Salud 总被引:2,自引:0,他引:2
A mass media health promotion program directed toward reducing future cancer trends among Mexican Americans, the largest subgroup of Hispanics in the United States, by decreasing smoking and encouraging smoking prevention and other health practices is described. Included is an outline of the program design and its significant features and a discussion of social modeling, the theoretical approach which provides a framework for the program. The development of the program, including the role focus groups played in the identification of areas to be targeted by the program, and the production and implementation of the mass media campaign based upon the targeted program areas are also discussed. 相似文献
5.
Nephrocalcinosis (NC) detected by ultrasound is a recognized abnormality for some patients with X-linked hypophosphatemia (XLH) who received vitamin D2 and inorganic phosphate therapy, but is commonly observed in XLH patients treated with 1,25-dihydroxyvitamin D3 and inorganic phosphate supplementation. Nevertheless, long-term follow-up of kidney function in XLH patients with NC detected ultrasonographically has not been reported. We investigated two women with XLH, ages 31 (patient 1) and 39 (patient 2) years, each of whom had suffered at least one documented episode of vitamin D2-induced hypercalcemia and renal azotemia during childhood. Patient 2 had also been treated with inorganic phosphate. No medications for XLH had been taken during adulthood. Renal ultrasonography at our institution demonstrated marked bilateral medullary NC in both women. No other explanation was found for their NC that apparently occurred several decades earlier from medical therapy for XLH. Detailed studies (including creatinine clearance, β2-microglobulin excretion, and fasting urinary osmolality and acidification) revealed no impairment of kidney function in either patient. Our findings indicate that subradiographic medullary NC acquired during medical therapy for XLH may persist for decades, but with no adverse renal sequelae. Definitive (long-term) assessment of kidney function in the XLH population with NC, however, will be necessary to fully understand the risk of current medical treatment for this most common heritable form of rickets. 相似文献
6.
Talo-patello-scaphoid osteolysis,synovitis, and short fourth metacarpals in sisters: a new syndrome?
Osteolysis syndromes are characterized by resorption of affected bones with associated swelling and pain. Various forms of multicentric osteolysis syndromes including autosomal dominant and recessive carpal-tarsal osteolysis, Torg, Fran?ois, Whyte-Hemingway, Hajdu-Cheney, Winchester, and other forms have been described. Most present in pre-school years with extensive involvement and destruction of multiple bones. We present a sister-pair, both of whom presented in early teenage, i.e., 13 and 15.5 years, respectively, with bilateral ankle, knee, and later, wrist pain. Radiological examination revealed bilateral osteolysis of tali, scaphoids, and patellae, and short fourth metacarpals in both sisters. Further investigation revealed absence of renal involvement, a normal excretion of amino acids, mucopolysaccharides and oligosaccharides, and presence of chronic synovitis in both sisters. Both parents and a younger brother were without radiographic or clinical evidence of the disease and there was no history of consanguinity. Thus, our sister-pair presented with the same carpal and tarsal bone involvement at a much later age, with evidence of chronic synovitis, along with short fourth metacarpals (brachydactyly type E changes) and without renal disease, suggesting a new syndrome with probable autosomal recessive inheritance. 相似文献
7.
Heike CL Cunningham ML Steiner RD Wenkert D Hornung RL Gruss JS Gannon FH McAlister WH Mumm S Whyte MP 《American journal of medical genetics. Part A》2005,(2):67-77
Epidermal nevus syndrome (ENS) is a rare, sporadic, congenital disorder of unknown etiology featuring a complex and highly variable phenotype that can include focal or generalized skeletal disease. We describe a young man with ENS manifesting right-sided linear skin lesions, generalized weakness, diffuse osteopenia associated with hypophosphatemic rickets, and distinctive focal bone lesions ipsilateral to the skin findings. Review of the literature concerning ENS-associated skeletal disease suggested such focal bone defects are fibrous dysplasia, but our patient did not have the typical radiographic or histopathologic findings of fibrous dysplasia. Nevertheless, his circulating fibroblast growth factor 23 (FGF-23) level was elevated, likely functioning as a "phosphatonin," yet no activating mutations in GNAS previously reported in fibrous dysplasia or McCune-Albright syndrome were detected in his leukocytes or affected skin. We postulate that the focal skeletal disease, although different than fibrous dysplasia, may be a source of FGF-23 in ENS. 相似文献
8.
Arbour NC; Zlotogora J; Knowlton RG; Merin S; Rosenmann A; Kanis AB; Rokhlina T; Stone EM; Sheffield VC 《Human molecular genetics》1997,6(5):689-694
Achromatopsia is an autosomal recessive disease of the retina,
characterized clinically by an inability to distinguish colors, impaired
visual acuity, nystagmus and photophobia. A genome-wide search for linkage
was performed using an inbred Jewish kindred from Iran. To facilitate the
genome-wide search, we utilized a DNA pooling strategy which takes
advantage of the likelihood that the disease in this inbred kindred is
inherited by all affected individuals from a common founder. Equal molar
amounts of DNA from all affected individuals were pooled and used as the
PCR template for short tandem repeat polymorphic markers (STRPs). Pooled
DNA from unaffected members of the kindred was used as a control. A
reduction in the number of alleles in the affected versus control pool was
observed at several loci. Upon genotyping of individual family members,
significant linkage was established between the disease phenotype and
markers localized on chromosome 2. The highest LOD score observed was 5.4
(theta = 0). When four additional small unrelated families were genotyped,
the combined peak LOD score was 8.2. Analysis of recombinant chromosomes
revealed that the disease gene lies within a 30 cM interval which spans the
centromere. Additional fine-mapping studies identified a region of
homozygosity in all affected individuals, narrowing the region to 14 cM. A
candidate gene for achromatopsia was excluded from this disease interval by
radiation hybrid mapping. Linkage of achromatopsia to chromosome 2 is an
essential first step in the identification of the disease-causing gene.
相似文献
9.
The management of hypertension in Canada: a review of current guidelines, their shortcomings and implications for the future 总被引:3,自引:1,他引:2
下载免费PDF全文
![点击此处可从《Canadian Medical Association journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Finlay A. McAlister Norman R.C. Campbell Kelly Zarnke Mitchell Levine Ian D. Graham 《Canadian Medical Association journal》2001,164(4):517-522
CLINICIANS ARE EXPOSED to numerous hypertension guidelines. However, their enthusiasm for these guidelines, and the impact of the guidelines, appears modest at best. Barriers to the successful implementation of a guideline can be identified at the level of the clinician, the patient or the practice setting; however, the shortcomings of the guidelines themselves have received little attention. In this paper, we review the hypertension guidelines that are most commonly encountered by Canadian clinicians: the “1999 Canadian Recommendations for the Management of Hypertension,” “The Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure” in the United States and the “1999 World Health Organization–International Society of Hypertension Guidelines for the Management of Hypertension.” The key points of these guidelines are compared and the shortcomings that may impede their ability to influence practice are discussed. The main implications for future guideline developers are outlined. 相似文献
10.
S Don C F Hildebolt T L Sharp G D Shackelford D M Lau T E Herman W H McAlister 《Radiology》1999,213(2):455-460
PURPOSE: To determine if computed radiography is equivalent to screen-film radiography in depicting pulmonary edema and to determine if radiation exposure can be reduced with computed radiography while maintaining equivalent diagnostic accuracy for pulmonary edema. MATERIALS AND METHODS: Oleic acid was intravenously injected into three rabbits at each of four doses: 0, 0.02, 0.04, and 0.06 mL/kg. Two hours later, chest computed radiographs and screen-film radiographs were obtained at 60 kVp and 1.1 mAs. Additional computed radiographs were obtained after reducing milliampere seconds or by reducing milliampere seconds and increasing the kilovolt peak, which reduced bone marrow exposure by up to 20%. The presence of pulmonary opacities, "truth," was established by the wet-dry weight ratio and by chest computed tomography (CT). The radiographs were masked and randomized. Four observers rated the images for the presence of parenchymal opacities with a dichotomous score and judged the quality of the radiographs on a scale from 1 (worst) to 6 (best). Cochran Q tests and McNemar tests were used to analyze the differences in paired comparisons. Image quality was evaluated with logistic regression analysis. RESULTS: There was no significant difference between truth and observer ability to detect opacity for either modality or for any exposure (P > .05). There was no significant difference between computed radiography and screen-film radiography for image quality (P > .05). CONCLUSION: Computed radiography is equivalent to screen-film radiography in the detection of pulmonary edema. Radiation exposure reduction of 20% can be achieved without affecting pulmonary edema detection or image quality. 相似文献