全文获取类型
收费全文 | 778篇 |
免费 | 92篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 42篇 |
妇产科学 | 16篇 |
基础医学 | 125篇 |
口腔科学 | 8篇 |
临床医学 | 81篇 |
内科学 | 187篇 |
皮肤病学 | 23篇 |
神经病学 | 13篇 |
特种医学 | 229篇 |
外科学 | 42篇 |
综合类 | 40篇 |
预防医学 | 39篇 |
眼科学 | 4篇 |
药学 | 12篇 |
中国医学 | 1篇 |
肿瘤学 | 22篇 |
出版年
2022年 | 2篇 |
2021年 | 9篇 |
2020年 | 7篇 |
2019年 | 2篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 11篇 |
2015年 | 9篇 |
2014年 | 6篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 15篇 |
2010年 | 23篇 |
2009年 | 29篇 |
2008年 | 18篇 |
2007年 | 19篇 |
2006年 | 21篇 |
2005年 | 24篇 |
2004年 | 14篇 |
2003年 | 32篇 |
2002年 | 16篇 |
2001年 | 5篇 |
2000年 | 13篇 |
1999年 | 22篇 |
1998年 | 52篇 |
1997年 | 49篇 |
1996年 | 39篇 |
1995年 | 24篇 |
1994年 | 43篇 |
1993年 | 29篇 |
1992年 | 15篇 |
1991年 | 17篇 |
1990年 | 24篇 |
1989年 | 33篇 |
1988年 | 27篇 |
1987年 | 25篇 |
1986年 | 31篇 |
1985年 | 24篇 |
1984年 | 18篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 25篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1976年 | 11篇 |
1975年 | 10篇 |
排序方式: 共有886条查询结果,搜索用时 15 毫秒
71.
The recognition of genital chlamydial infection as an important public health problem was made first by the recognition of its role in acute clinical syndromes, as well as in serious reproductive and ocular complications, and secondly by our awareness of its prevalence when diagnostic tests became widely accessible. The recent availability of effective single dose oral antimicrobial therapy and sensitive molecular amplification tests that allow the use of noninvasive specimens for diagnosis and screening is expected to have a major impact in reducing the prevalence of disease in the next decade. Clinical manifestations associated with Chlamydia pneumoniae infection continue to emerge beyond respiratory illness. In particular, its association with atherosclerosis deserves further investigation. Chlamydia pecorum, a pathogen of ruminants, was recently recognized as a new species. The continued application of molecular techniques will likely elucidate an expanding role for chlamydiae in human and animal diseases, delineate the phylogenetic relationships among chlamydial species and within the eubacteria domain, and provide tools for detection and control of chlamydial infections. 相似文献
72.
73.
74.
Prostatic evaluation by transrectal sonography with histopathologic correlation: the echopenic appearance of early carcinoma 总被引:6,自引:0,他引:6
Fifty-two patients with clinical stage A and B carcinomas of the prostate were imaged by ultrasound (US) transrectally with a 5-MHz linear array transducer and transabdominally with a 3-MHz sector scanner prior to radical prostatectomy. The fresh specimens of 44 prostate glands were scanned in a water bath with a 5-MHz linear array transducer in multiple planes. In all cases, histopathologic correlation was obtained. Prostatic carcinoma presented as an echopenic lesion in 54% of the specimens, as a slightly hypoechoic area in 22%, and could not be identified in 24% because of its isoechoic characteristics. In contrast to many previous reports, no instance of echogenic cancer was observed. 相似文献
75.
Tartrate-resistant acid phosphatase (TRAcP) is used as a marker for osteoclasts, which are believed to be derived from phagocytic cells or phagocyte stem cell precursors. To further investigate the relationship between monocytic phagocytes and osteoclasts, acid phosphatase (AcP) activity was measured by three different techniques in human peripheral blood monocytes, monocyte-derived macrophages, and the U937 cell line. We found that cytochemistry and gel electrophoresis led to similar results, but that the colorimetric assay was inconsistent. Normal human peripheral monocytes expressed both tartrate-sensitive and -resistant AcP. In culture these cells formed polykaryons and expressed TRAcP activity that was further identified as an isoenzyme associated with bone tissue. In contrast, the U937 cells did not express TRAcP activity as measured by gel electrophoresis. Both U937 cells and monocytes possess material that interferes with interpretation of the colorimetric assay of AcP. The presence of TRAcP in monocyte-derived macrophages further supports the relationship between phagocytic cells and bone osteoclasts. 相似文献
76.
77.
L Cigliano†‡ B Maresca§ A Salvatore† M Nino§ G Monfrecola§ F Ayala§ A Carlucci† RC Pugliese§ C Pedone† P Abrescia† 《Journal of the European Academy of Dermatology and Venereology》2008,22(4):417-425
Objective The aim of this work was to assess whether psoriasis is associated with phenotype prevalence and altered activity of haptoglobin (Hpt). Background Hpt is a plasma acute‐phase glycoprotein, displaying in humans three phenotypes. Phenotype prevalence or structure modification of Hpt was associated with several diseases. The Hpt main function is to bind and carry to the liver free haemoglobin for degradation and iron recycling. Hpt was recently found able to bind the apolipoprotein A‐I (ApoA‐I), thus impairing its stimulation on the activity of the enzyme lecithin‐cholesterol acyl‐transferase (LCAT). Study design Hpt was isolated from patients with psoriasis vulgaris, and its activity in haemoglobin or ApoA‐I binding and LCAT inhibition was compared with that of normal protein. Methods Two affinity chromatography steps, the first using resin‐coupled haemoglobin and the second anti‐Hpt antibodies, were used to purify Hpt. The protein phenotype was assessed by electrophoresis. Binding experiments were performed by Enzyme‐linked immunosorbent assay with stationary haemoglobin or ApoA‐I, Hpt in solution and anti‐Hpt antibodies for detection of bound Hpt. Standard LCAT assays were carried out in the presence of Hpt purified from patients or healthy subjects. Results Phenotype prevalence of Hpt in psoriasis was not found. After affinity chromatography by haemoglobin, albumin and ApoA‐I were routinely found heavily contaminating only Hpt from normal subjects. Isolated Hpt from patients had lower activity than normal protein in both haemoglobin binding and LCAT inhibition. Conclusions In psoriasis, Hpt displays some structure modification(s), which might be associated with the protein function in the disease. 相似文献
78.
Antimicrobial susceptibility testing and phenotyping of Neisseria gonorrhoeae isolated from patients with ophthalmia neonatorum in Nairobi, Kenya. 下载免费PDF全文
R C Brunham L Fransen F Plummer P Piot L Slaney S Bygdeman H Nsanze 《Antimicrobial agents and chemotherapy》1985,28(3):393-396
Antimicrobial susceptibility testing, auxotyping-serotyping, and plasmid analysis were performed on 41 ocular isolates, 7 nasopharyngeal isolates, and 18 cervical isolates of Neisseria gonorrhoeae obtained during a recent treatment trial of gonococcal ophthalmia neonatorum in Nairobi, Kenya. Fourteen distinct serovar-auxotype patterns were observed with IB-1/Pro-strains which accounted for 59% of the isolates. Infection with multiple types of gonococci appeared to occur in 22% of the mothers since 4 of 18 paired maternal cervical and neonatal ocular isolates had mismatched serovar-auxotype patterns. Among 10 treatment failure isolates only 1 had a mismatched serovar-auxotype pattern. Six (15%) of the ocular isolates were penicillinase-producing N. gonorrhoeae (PPNG). Five had the 4.4-megadalton (Md) beta-lactamase plasmid and one had the 3.2-Md beta-lactamase plasmid. The 24.5-Md plasmid was found in 5 of 6 PPNG strains and in 8 of 35 non-PPNG strains (P less than 0.02). For most antimicrobial agents, PPNG and non-PPNG strains showed similar patterns of susceptibility. Ceftriaxone was the most active of the antibiotics tested, with all strains having an MIC less than or equal to 0.06 mg/liter. Among non-PPNG strains, 15 (43%) had a penicillin MIC greater than or equal to 2 mg/liter and were considered intrinsically resistant to penicillin. Overall, non-PPNG intrinsically resistant strains had greater resistance to other antibiotics than did non-intrinsically resistant strains (P less than or equal to 0.006). The Mtr phenotype was found in 53% of these strains. 相似文献
79.
Growth hormone therapy for protein catabolism 总被引:5,自引:0,他引:5
GH and IGF-I have shown remarkable consistency of effect in a wide range of
catabolic conditions. Doses of around 10 IU/m2/day of GH and 80
micrograms/kg/day of IGF-I over short periods of time can improve net
protein synthesis and preserve lean body mass. Most studies have reported
metabolic endpoints, but favorable clinical effects have included decreased
hospital stay and mortality in burns, improved respiratory muscle function
in COAD, preserved grip strength post- operatively, and improvements in
cardiac and bowel failure. Adverse effects of GH treatment are uncommon and
usually related to glycaemic control. GH and IGF-I have differential
effects on insulin concentrations--increasing or decreasing concentrations,
respectively. The hypoglycaemic effects of IGF-I are dependent on route of
administration and are avoided by subcutaneous delivery. Occasional
patients have needed to discontinue GH treatment due to hyperglycaemia,
although the anabolic action of GH may be partially mediated by increased
insulin levels. The co-administration of GH and IGF-I has theoretical
advantages by both increasing IGF binding-protein concentrations and
balancing glycaemic control. An initial study with combination therapy in
calorically-restricted volunteers has shown anabolic effects greater than
with either agent alone. This approach requires further study in catabolic
patients. There is a need for large, well-designed trials with clinical
rather than purely metabolic end-points, and some of these are already
underway. Should these studies confirm the early findings, financial
considerations will become paramount, although it remains possible that
treatment may be self-financing if lengths of hospital admissions are
shortened.
相似文献
80.