全文获取类型
收费全文 | 2868篇 |
免费 | 126篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 113篇 |
妇产科学 | 26篇 |
基础医学 | 563篇 |
口腔科学 | 78篇 |
临床医学 | 301篇 |
内科学 | 712篇 |
皮肤病学 | 114篇 |
神经病学 | 58篇 |
特种医学 | 289篇 |
外科学 | 230篇 |
综合类 | 57篇 |
预防医学 | 138篇 |
眼科学 | 34篇 |
药学 | 194篇 |
中国医学 | 1篇 |
肿瘤学 | 109篇 |
出版年
2016年 | 30篇 |
2015年 | 31篇 |
2014年 | 45篇 |
2013年 | 106篇 |
2012年 | 64篇 |
2011年 | 49篇 |
2010年 | 63篇 |
2009年 | 50篇 |
2008年 | 65篇 |
2007年 | 89篇 |
2006年 | 85篇 |
2005年 | 71篇 |
2004年 | 60篇 |
2003年 | 65篇 |
2002年 | 44篇 |
2001年 | 56篇 |
2000年 | 49篇 |
1999年 | 54篇 |
1998年 | 89篇 |
1997年 | 101篇 |
1996年 | 111篇 |
1995年 | 79篇 |
1994年 | 79篇 |
1993年 | 77篇 |
1992年 | 55篇 |
1991年 | 46篇 |
1990年 | 58篇 |
1989年 | 77篇 |
1988年 | 63篇 |
1987年 | 57篇 |
1986年 | 56篇 |
1985年 | 50篇 |
1984年 | 61篇 |
1983年 | 32篇 |
1982年 | 32篇 |
1981年 | 39篇 |
1980年 | 50篇 |
1978年 | 27篇 |
1977年 | 35篇 |
1976年 | 38篇 |
1975年 | 36篇 |
1972年 | 24篇 |
1971年 | 24篇 |
1970年 | 23篇 |
1965年 | 51篇 |
1964年 | 50篇 |
1963年 | 47篇 |
1962年 | 41篇 |
1961年 | 40篇 |
1960年 | 65篇 |
排序方式: 共有3024条查询结果,搜索用时 31 毫秒
61.
62.
The DNA of the human serum amyloid A (SAA) gene GSAA1 contains several repetitive regions within its introns. We have studied length variations at one such region in the 2nd intron by selective amplification using the polymerase chain reaction (PCR) and defined oligonucleotide primers. The lengths of the repetitive regions frequently differ between individual chromosomes and can be transmitted as Mendelian markers, making them useful for genetic linkage analysis. 相似文献
63.
64.
Incidence of and risk factors for lipoatrophy (abnormal fat loss) in ambulatory HIV-1-infected patients 总被引:4,自引:0,他引:4
Lichtenstein KA Delaney KM Armon C Ward DJ Moorman AC Wood KC Holmberg SD;HIV Outpatient Study Investigators 《Journal of acquired immune deficiency syndromes (1999)》2003,32(1):48-56
To identify clinical factors associated with the incidence of HIV-1-associated lipoatrophy, HIV-1-infected patients in the HIV Outpatient Study (HOPS) were prospectively evaluated for clinical signs of lipoatrophy at two visits about 21 months apart. Development of lipoatrophy was analyzed in stratified and multivariate analyses for its relationship to immunologic, virologic, clinical, and drug treatment information for each patient. Of 337 patients with no lipoatrophy at Survey 1, 44 (13.1%) developed moderate or severe lipoatrophy between the two surveys. In multivariate analyses, significant risk factors for incident lipoatrophy were white race (OR = 5.2; 95% CI: 1.9-17.1; =.003), CD4 T-lymphocyte count at Survey 2 less than 100 cells/mm3 (OR = 4.2; 95% CI: 1.3-13.1; =.013), and body mass index (BMI) less than 24 kg/m2 (OR = 2.4; 95% CI: 1.1-5.4; =.024). Analyses that controlled for the severity of HIV illness demonstrated no significant association with use of or time on any antiretroviral agent or class of agents and the development of lipoatrophy. Some host factors and factors associated with previous or current severity of HIV infection, especially CD4 T-lymphocyte cell count, appeared to have the strongest association with incidence of lipoatrophy. 相似文献
65.
Peter A. Shapiro Richard P. Sloan Emilia Bagiella J. Thomas Bigger JR. Jack M. Gorman 《Psychophysiology》1996,33(1):54-62
Heart rate reactivity to mental stress is substantially blunted early after heart transplantation, suggesting that the loss of neural modulation limits the cardiovascular response to mental stress. We tested whether reactivity to mental stress recovers during the first year after heart transplantation. Hemodynamic and respiratory responses to mental arithmetic challenge were studied in 20 heart transplant recipients 3, 6, and 12 months after surgery. A normal comparison group was studied at equivalent intervals. Heart rate reactivity to mental arithmetic was significantly reduced in the cardiac transplant group compared to the normal subjects. This effect persisted up to 1 year after transplantation. Heart period variability in the heart transplant recipients was minimal in all three-test sessions. The findings suggest that no functional reinnervation or other compensatory adaptation occurs up to 1 year after heart transplantation. 相似文献
66.
IgG antibody to gE, the Fc gamma-binding herpes simplex 1 (HSV-1) viral glycoprotein, was studied in 49 rheumatoid arthritis (RA) patients and 43 normal controls. Antibody to gD, another important HSV-1 antigen, was assayed in parallel. No difference between RA patients and normal controls was found in levels of anti-gE antibody measured by reactivity of IgG F(ab')2 fragments reacting with gE coated to ELISA plates. No difference in anti-gD antibody was recorded between normals and patients with RA. Levels of IgG anti-IgE antibody did not correlate with quantitative elevations of serum rheumatoid factor (RF) in RA patients. When IgG anti-gE and anti-gD were assayed in 20 patients with juvenile rheumatoid arthritis and 22 children controls, no significant differences were noted. However, when individual RFs from patients with RA were tested for reactivity against a panel of affinity-isolated F(ab')2 antibodies to gE, some evidence for individual autospecificity was obtained. Four of 20 monoclonal IgM RFs produced from RA patients' B cells showed marked elevations of reactivity with some RA patients' F(ab')2 antibodies to gE. All four of the monoclonal RFs showing this specificity were derived from RA synovial tissue B cells. These findings may provide support for the concept that some RFs in patients with RA show individual specificity for internal image determinants of IgG antibodies to viral Fc gamma-binding proteins. 相似文献
67.
68.
Myotonic dystrophy, a progressive autosomal dominant disorder, is associated with an expansion of a CTG repeat tract located in the 3'-untranslated region of a serine/threonine protein kinase, DMPK. DMPK modulates skeletal muscle Na channels in vitro, and thus we hypothesized that mice deficient in DMPK would have altered muscle Na channel gating. We measured macroscopic and single channel Na currents from cell-attached patches of skeletal myocytes from mice heterozygous (DMPK(+/-)) and homozygous (DMPK(-/-)) for DMPK loss. In DMPK(-/-) myocytes, Na current amplitude was reduced because of reduced channel number. Single channel recordings revealed Na channel reopenings, similar to the gating abnormality of human myotonic muscular dystrophy (DM), which resulted in a plateau of Na current. The gating abnormality deteriorated with increasing age. In DMPK(+/-) muscle there was reduced Na current amplitude and increased Na channel reopenings identical to those in DMPK(-/-) muscle. Thus, these mouse models of complete and partial DMPK deficiency reproduce the Na channel abnormality of the human disease, providing direct evidence that DMPK deficiency underlies the Na channel abnormality in DM. 相似文献
69.
van den Brink JL Moorman PW de Boer MF Pruyn JF Verwoerd CD van Bemmel JH 《International journal of medical informatics》2005,74(10):839-849
OBJECTIVE: To determine use, appreciation and effectiveness of an electronic health information support system in head and neck (H&N) cancer care. DESIGN: A prospective evaluation study. The evaluated system has four different functions: (1) communication amongst health care providers and between health care providers and patients, (2) information for health care providers and patients, (3) contact with fellow sufferers and (4) monitoring of discharged patients by means of electronic questionnaires. Evaluation of the system was done both objectively using automatically created log files and stored messages, and subjectively by using paper questionnaires from patients and general practitioners (GPs). SETTING: Department of Otorhinolaryngology and Head and Neck Surgery of a tertiary health care centre in the Netherlands. The system was put at patients' disposal for a period of 6 weeks following discharge from the hospital after surgery for H&N cancer, and was additional to standard care. PARTICIPANTS: Head and neck cancer patients, hospital physicians, members of a hospital-based support team, GPs, district nurses and speech therapists. MAIN OUTCOME MEASURES: Actual use of the system by patients and health care providers. Patients' appreciation for each of the system's four different functions. GPs' appreciation for the system. Capability to detect potential patient problems with the system. RESULTS: The system was used by 36 H&N cancer patients, 10 hospital physicians, 2 members of the support team, 8 GPs, 2 district nurses and 2 speech therapists. The total number of patient-sessions was 982: an average of 27.3 sessions per patient during the 6 weeks study period. In total, 456 monitoring questionnaires were completed. The support team in hospital responded with 231 actions. In 16 cases, an extra appointment was made for a patient with the hospital physician. Out of these cases, immediate action was considered necessary eight times. Patients appreciated the system highly, rating it with an average score of 8.0 on a 10-point scale. All patients used the monitoring function, and rated 'monitoring' with a mean score of 8.0 on a 10-point scale. Least used and appreciated was the 'contact with fellow sufferers' function. Only 8 out of possible 36 GPs used the system, rating it with an average of 5.6 on a 10-point scale. CONCLUSIONS: The electronic health information support system was used intensively and highly appreciated by H&N cancer patients. The system enabled the early detection of occurring health problems that required direct intervention. ICT can play an additional role in the management of patients, also in a relatively elderly and computer illiterate patient population. 相似文献
70.