全文获取类型
收费全文 | 2981篇 |
免费 | 213篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 48篇 |
儿科学 | 229篇 |
妇产科学 | 93篇 |
基础医学 | 472篇 |
口腔科学 | 34篇 |
临床医学 | 279篇 |
内科学 | 698篇 |
皮肤病学 | 11篇 |
神经病学 | 277篇 |
特种医学 | 230篇 |
外国民族医学 | 1篇 |
外科学 | 328篇 |
综合类 | 59篇 |
一般理论 | 2篇 |
预防医学 | 144篇 |
眼科学 | 100篇 |
药学 | 113篇 |
中国医学 | 2篇 |
肿瘤学 | 105篇 |
出版年
2021年 | 25篇 |
2019年 | 30篇 |
2018年 | 42篇 |
2017年 | 27篇 |
2016年 | 39篇 |
2015年 | 44篇 |
2014年 | 52篇 |
2013年 | 71篇 |
2012年 | 117篇 |
2011年 | 120篇 |
2010年 | 75篇 |
2009年 | 56篇 |
2008年 | 101篇 |
2007年 | 128篇 |
2006年 | 101篇 |
2005年 | 93篇 |
2004年 | 108篇 |
2003年 | 96篇 |
2002年 | 85篇 |
2001年 | 105篇 |
2000年 | 118篇 |
1999年 | 101篇 |
1998年 | 56篇 |
1997年 | 42篇 |
1996年 | 30篇 |
1995年 | 35篇 |
1994年 | 35篇 |
1993年 | 31篇 |
1992年 | 83篇 |
1991年 | 93篇 |
1990年 | 57篇 |
1989年 | 68篇 |
1988年 | 70篇 |
1987年 | 65篇 |
1986年 | 71篇 |
1985年 | 60篇 |
1984年 | 40篇 |
1983年 | 44篇 |
1982年 | 24篇 |
1981年 | 29篇 |
1980年 | 25篇 |
1979年 | 37篇 |
1978年 | 26篇 |
1977年 | 35篇 |
1976年 | 23篇 |
1974年 | 24篇 |
1971年 | 22篇 |
1926年 | 23篇 |
1925年 | 28篇 |
1924年 | 22篇 |
排序方式: 共有3225条查询结果,搜索用时 31 毫秒
1.
Intratemporal vascular tumors: detection with CT and MR imaging 总被引:1,自引:0,他引:1
Lo WW; Shelton C; Waluch V; Solti-Bohman LG; Carberry JN; Brackmann DE; Wade CT 《Radiology》1989,171(2):445-448
The diagnostic contributions of computed tomography (CT) and magnetic resonance (MR) imaging were compared in 12 patients with benign intratemporal vascular tumors (hemangioma or vascular malformation). The tumors included six in the internal acoustic canal and six in the geniculate ganglion region. Clinical and histologic correlations were made. Two of the six patients with tumors in the internal acoustic canal underwent CT, and both required gas cisternography to show the tumor. Five patients in that group underwent MR imaging, and all five studies showed the tumor. All six patients with geniculate ganglion tumors underwent CT. Results in one study were questionable, and five showed the tumor. Five patients in this group underwent MR imaging, but the MR findings were positive in only two cases. MR imaging should therefore be performed before CT in the evaluation of facial nerve dysfunction, as it demonstrated all tumors in the internal acoustic canal and some in the geniculate ganglion region. If MR findings are negative, CT should then be performed to rule out a possible geniculate ganglion lesion. 相似文献
2.
Insulin-like growth factors (IGF-I and -II) are peptide growth factors that may be important for neonatal development. Specific high affinity IGF binding proteins (BPs) have been characterized in serum and extracellular fluids. The major serum binding complex in the adult has an apparent Mr of 150 K, while the predominant BP in the neonate is approximately 30 K. In the rat, the transition from the neonatal BP to the adult form occurs during the third postnatal week, concomitant with an increase in serum IGF-I and a decrease in serum IGF-II concentrations. Using specific RIAs and Western ligand blot analyses we have characterized the changes in serum IGF and IGF BPs, respectively, during the early postnatal period. Seven BPs were identified in serum with apparent Mr values of 42, 41, 40, 38, 28, 26, and 22 K. After deglycosylation, the 42, 41, 40, and 38 K BPs were reduced to two bands with apparent Mr values of 35 and 32 K, while the 28, 26, and 22 K BP were unchanged. In the neonate, the 28, 26, and 22 K BPs were present, with the 28 K BP in highest concentration. With increasing age, the 28 K BP decreased and the 42, 41, 40, and 38 K BPs appeared at approximately 19 days of age. Comparison of Western ligand blots of neonatal serum, BRL-3A conditioned media, rat amniotic fluid, and rat cerebrospinal fluid (CSF) demonstrated that all contained a prominent 28 K BP. A polyclonal antibody (alpha Hec 1) developed against the 31 K human IGF-BP (hBP-31) immunoprecipitated the 28 K BP from neonatal rat serum, BRL-3A media, rat amniotic fluid, and rat CSF, but did not react with adult rat serum. These findings suggest that, in the rat, the predominant neonatal serum BP is structurally and immunologically similar to the major BRL-3A, amniotic fluid, and CSF BPs, but distinct from the predominant adult serum BP. 相似文献
3.
4.
K.A. Eaton F.M. Rimini E. Zak D.J. Brookman L.M.A. Hopkins P. J. Carmell LG. Yates C. A. Morrice B.A. Lall H. N. Newman 《Journal of clinical periodontology》1997,24(3):189-197
Abstract Several previous studies have evaluated the effects of 0.12% chlorhexidine digluconate (ChD) mouthrinses on plaque and gingival inflammation. However, previously, none have been based in general dental practices. The aim of this study was to evaluate the potential to conduct controlled periodontal clinical trials in co-operation with general dental practitioners (gdps). The project took place in 5 general dental practices in the South of England. 121 healthy subjects (24 at 4 sites and 25 at the 5th). aged 18-65 years, mean 35 ± 12) years participated in a double-blind, randomised study during which they received full mouth assessments for plaque and gingival bleeding at baseline, 6 and 12 weeks. 60 subjects were randomly asigned to use the 0.12% ChD mouth wash and 6i the placebo. The assessments were carried out by 5 gpds, who had previously achieved inter-examiner κ scores of 0.78–0.85 (mean 0.81) for the plaque index (PlI), and of 0.73–0.94 (mean 0.87) for a modified gingival index (mGI), and who maintained κ scores of 0.51–0.90 for PII and of 0.73–1.00 for mGI during the 12 months required to complete the study. 98 subjects (48 ChD and 50 placebo) completed the study. Even though the baseline levels of plaque and gingivitis were low, by week 12, mean whole mouth piaque score of the ChD mouthwash users had fallen from 1.33 at baseline to 0.96 and was significantly lower (p < 0.001) than for the placebo users, 1.31 at baseline to 1.13. Whole-mouth gingival bleeding score fell from 0.56 to 0.42 in the ChD mouthwash group but was unchanged (0.54–0.55) in the placebo group. A subsidiary data analysis which considered the effects at sites indicated that within these overall differences, the ChD users experienced almost 2× the reduction from plaque score 2 at baseline at proximal molar sites over a 12-week period (50.6% ChD versus 27.6% placebo). It was concluded that 0.12% ChD mouthwash reduced plaque accumulation fay 28% and gingival inflammation by 25% over a 12–week period, that it is feasible for a group of gdps to maintain high levels of inter–examiner consistency in the use of PlI and mGI, that it is also feasible to carry out such a multicentre study in general dental practice, and that the use of mean mouth scores per subject to analyse the effects of mouthrinses may well mask variations in response throughout the mouth. 相似文献
5.
Pyloromyotomy of Ramstedt: experience of a nonspecialized centre 总被引:2,自引:0,他引:2
In a general hospital over a period of 6 years 57 infants with congenital hypertrophic stenosis underwent a Ramstedt pylorotomy. In most cases a surgical resident-in-training performed the operation under the direct supervision of a general surgeon. There were no complications of anesthesia, no deaths and no substantial morbidity. The majority of infants left the hospital within 48 hours. The results in this series compared favourably with those reported from more specialized centres. 相似文献
6.
7.
R M Rosenfeld 《Archives of otolaryngology--head & neck surgery》1992,118(4):445-447
8.
Jeffrey V. Rosenfeld MS FRACS FRCS 《Journal of clinical neuroscience》1994,1(4):231-242
Great advances in neurobiology have resulted from 100 years of neural transplantation research. In the last 20 years, there has been a focus on using neural transplantation to repair the damaged central nervous system (CNS) utilising experimental animal models of various human neurodegenerative disease and CNS injury. Since 1985, there has been a rapid proliferation of adrenal medullary autograft transplantation to the caudate nucleus of humans with Parkinson's disease. However, this operation proved to be unsuccessful and was associated with unacceptable morbidity. Implantation of human fetal mesencephalon into patients with severe parkinsonism has supplanted the adrenal operation and has produced promising results, with some patients reported to improve markedly and some evidence of graft survival noted on positron emission tomography (PET). Host tissue recovery appears to be an important mechanism for this clinical improvement. The optimal technique is to use three to four fetuses from induced abortions of 6.5 to 8 weeks gestation, with multiple stereotactic implants into the putamen and caudate nucleus. Many biological questions still remain and the community remains troubled by the ethical problems of using fetal tissue obtained from abortions. This procedure is still experimental and should be restricted to a few centres with excellence in cell and molecular biology. A multicentre study is needed to more carefully evaluate CNS transplantation. Cloned neural precursor cells or immortalized embryonic cell lines genetically modified to manufacture selected growth factors or neurotransmitters may offer an alternative to the use of human fetal tissue. Much more experimental animal research is necessary before transplantation can be used to treat other CNS maladies. 相似文献
9.
Impact of pediatricians' attire on children and parents 总被引:1,自引:0,他引:1
R V Marino W Rosenfeld P Narula M Karakurum 《Journal of developmental and behavioral pediatrics : JDBP》1991,12(2):98-101
To evaluate perceptions of a pediatrician's attire, 50 children and parents in an outpatient facility were shown five photographs of a female or a male physician dressed differently (formal to informal). A list of positive and negative attributes was presented to the parents and children who were to match each picture to the attributes. Parents had a strong positive preference for the formally dressed female (short white coat and skirt), and the formally dressed male (short white coat and tie). More than 50% of the parents least preferred the most informal attire. Children had no clear preferences for males and preferred the female in the blouse and skirt. Children assigned negative attributes to informal attire but not to the same degree as did their parents. This study demonstrates that parents have stronger preferences than do their children. Although children had no strong positive preferences, they may feel negatively about informal attire. 相似文献
10.
LG Dortmund 《MedR Medizinrecht》2007,25(8):493-494
Abstrakt Vergibt ein behandelnder Arzt eine Laboruntersuchung an einen externen Laborarzt, kommt entweder direkt ein Vertragsverh?ltnis
zwischen dem Laborarzt und dem Patienten zustande oder der Patient haftet dem Laborarzt aus den Grunds?tzen der Gesch?ftsführung
ohne Auftrag. 相似文献