全文获取类型
收费全文 | 8969篇 |
免费 | 564篇 |
国内免费 | 64篇 |
专业分类
耳鼻咽喉 | 100篇 |
儿科学 | 246篇 |
妇产科学 | 324篇 |
基础医学 | 1003篇 |
口腔科学 | 362篇 |
临床医学 | 764篇 |
内科学 | 1808篇 |
皮肤病学 | 215篇 |
神经病学 | 428篇 |
特种医学 | 304篇 |
外国民族医学 | 5篇 |
外科学 | 1552篇 |
综合类 | 173篇 |
现状与发展 | 2篇 |
一般理论 | 5篇 |
预防医学 | 518篇 |
眼科学 | 250篇 |
药学 | 959篇 |
中国医学 | 61篇 |
肿瘤学 | 518篇 |
出版年
2023年 | 111篇 |
2022年 | 337篇 |
2021年 | 487篇 |
2020年 | 328篇 |
2019年 | 428篇 |
2018年 | 525篇 |
2017年 | 324篇 |
2016年 | 347篇 |
2015年 | 330篇 |
2014年 | 394篇 |
2013年 | 537篇 |
2012年 | 705篇 |
2011年 | 679篇 |
2010年 | 399篇 |
2009年 | 290篇 |
2008年 | 442篇 |
2007年 | 394篇 |
2006年 | 370篇 |
2005年 | 390篇 |
2004年 | 325篇 |
2003年 | 289篇 |
2002年 | 241篇 |
2001年 | 79篇 |
2000年 | 46篇 |
1999年 | 65篇 |
1998年 | 57篇 |
1997年 | 37篇 |
1996年 | 40篇 |
1995年 | 30篇 |
1994年 | 25篇 |
1993年 | 27篇 |
1992年 | 36篇 |
1991年 | 40篇 |
1990年 | 31篇 |
1989年 | 31篇 |
1988年 | 26篇 |
1987年 | 32篇 |
1986年 | 24篇 |
1985年 | 38篇 |
1984年 | 29篇 |
1983年 | 26篇 |
1982年 | 19篇 |
1981年 | 20篇 |
1980年 | 19篇 |
1979年 | 22篇 |
1978年 | 11篇 |
1977年 | 12篇 |
1976年 | 21篇 |
1975年 | 14篇 |
1972年 | 13篇 |
排序方式: 共有9597条查询结果,搜索用时 15 毫秒
1.
Mahmoud R Hussein Dalia A Elsers Sabah A Fadel Abd-Elhady M Omar 《European journal of cancer prevention》2006,15(1):64-68
Although melanocytic skin lesions have been recognized since antiquity, their literature was limited to Caucasians. To date, the clinicopathologic features of these lesions in Egyptians are still unknown. To define these features, diagnostic records of the melanocytic skin lesions received at the Pathology Department, Assuit University Hospitals (1989-2004) were reviewed. The lesions examined included 12 benign naevi (BN), 10 dysplastic naevi (DN), and 21 cutaneous malignant melanomas (CMMs). The DN and CMMs were more common in men than in women (2 : 1 and 1.5 : 1, respectively) while BN were more common in women (2 : 1). The average age incidence was 33+/-5, 38+/-7 and 54+/-3 years, for BN, DN and CMM, respectively. The lower limb (13/21, 62%), head and neck (7/21, 33%) were the most common sites for CMMs. The average size (mm) was 2+/-0.3, 4+/-0.6 and 21+/-0.3 for BN, DN and CMMs, respectively. Recurrence occurred in 10% of CMMs. Histologically, CMMs were of nodular type and composed of epithelioid (7/21, 33%), spindle cells (1/21, 5%), or mixed cells (13/21, 62%). The mean tumour thickness (Breslow) was 6+/-0.5 mm. CMMs included two of 21(9%), three of 21(14%), six of 21(38%), and 10 of 21(38%) with Clark level II, III, IV and V. In Egypt, CMM is the third most common cutaneous neoplasm following squamous and basal cell carcinomas. Compared with Western societies, melanoma has a male sex predilection, similar histological features but different topographical distribution and rare incidence. The striking difference from Western series is the incidence of nodular melanoma - in the West this represents 15-30% of melanomas, with superficial spreading being the majority. Another key difference from the West is the 'sun-bed' culture of the West and the desire to have suntans. This is the first study that reports the clinicopathologic features of melanocytic skin lesions in Egypt. 相似文献
2.
Tarek A. Amer Tarek F. Elwakil Mahmoud S. Elbasiouny 《European journal of plastic surgery》2007,30(2):67-73
Haemangiomas are the most common tumours of infancy. They typically proliferate then involute with considerable variation
as regards to their rates of proliferation and involution. Haemangioma of the nasal tip is a lesion of special characteristics.
During proliferation, it expands, contracts and deviates the nasal cartilages. Particularly, it regresses slowly and frequently
involutes incompletely. That is why excision of the lesion is frequently suggested. The present study was conducted to evaluate
open rhinoplasty after initial non-excision treatment modalities namely, intra-lesional corticosteroid injections and laser
treatment, as a protocol of treatment for nasal tip haemangiomas. Twelve patients with nasal tip haemangiomas were included
in the present study. Patients of both sexes, of different ages, with deep and mixed haemangiomas were studied. Disfigurement
was the constant presenting symptom. Initial non-excision treatment reported different responses as denoted by the regression
of the lesions’ size. Haemangiomas constantly extended between the medial crura of the alar cartilages as noted by the constant
widening of the columella pre-operatively and the obvious separation of the nasal cartilages intra-operatively. This separation
was constantly found to require approximation by sutures. The results of the present study concluded that whenever an early
presentation with nasal tip haemangioma could be established, initial non-excision treatment followed by open rhinoplasty
could be a useful protocol of treatment. Within the limitations of the present study, this protocol could achieve an early,
safe and effective treatment for nasal tip haemangiomas with provisionally acceptable cosmetic outcomes so far. 相似文献
3.
4.
5.
Abbas Pardakhty Alireza Foroumadi Mehdi Hashemi Saeed Rajabalian Mahmoud Reza Heidari 《Toxicology in vitro》2007,21(6):1031-1038
We examined the cytotoxic potential of nine N-[2-substituted-2-(2-thienyl)ethyl] piperazinyl quinolone derivatives on human oral epithelial mouth carcinoma (KB) and human squamous carcinoma (A431) cell lines. Phototoxic properties of these compounds were also evaluated by mouse 3T3 fibroblast under ultraviolet-A (UVA) irradiation. The percent of cell viability was evaluated by MTT assay. Compound 6 having a 4-[2-(phenylmethoxyimino)-2-(2-thienyl)ethyl] group attached to N4 position of piperazine ring of enoxacin showed the highest cytotoxicity potential on both A431 and KB cell lines (IC50 of 3.11+/-0.52 and 4.91+/-1.94 microg/ml, respectively). While some of the other tested compounds exhibited clear phototoxic potential in 3T3 cell line, compound 6 showed only a minor potential of phototoxicity. These findings suggest the high potential of 4-[2-(phenylmethoxyimino)-2-(2-thienyl)ethyl] derivative of enoxacin as a cytotoxic compound with low potency of phototoxic reactions. The mentioned chemical was identified to be of special interest for further characterization. 相似文献
6.
Daphna Mezad Mordechai Hallak Mahmoud Huleihel Limor Gortzak-Uzan Ana Smolin Moshe Mazor 《Magnesium research》2002,15(3-4):247-252
Our objective was to evaluate the effect of intravenous magnesium sulphate administration to patients with preterm labour on maternal serum and amniotic fluid IL-1beta, IL-6, IL-10 and TNFalpha concentrations. Thirty-six patients at 24-34 weeks of singleton gestation, who presented with contractions (> or = 8 in 60 min) had amniocentesis to rule out intrauterine infection. The patients received intravenous MgSO4 for tocolysis. Twenty-six patients had amniocentesis performed before initiation of MgSO4 (controls) while 10 others had the procedure during tocolytic therapy (study patients). Magnesium, IL-1beta, IL-6, TNFalpha and IL-10 concentrations were measured. Study and control groups were statistically compared using Student t test. Mean magnesium levels were significantly higher in the study group (P < 0.01). There were no significant differences between the cytokines levels in maternal serum and in amniotic fluid between the groups. Our results suggest that the mechanism of magnesium as a tocolytic agent may not be mediated via the examined cytokines. 相似文献
7.
Carcinoma of the urinary bladder is a common malignancy in many tropical and subtropical countries. There is a well documented sequela of chronic urinary schistosomal infection and bladder cancer associated with schistosomiasis is a major cause of morbidity and mortality in the endemic areas. Experimental bladder cancer can be induced in schistosome-infected animals. Multiple factors have been suggested as causative agents in schistosome-associated bladder carcinogenesis and the N-nitroso compounds appear to be of particular importance. These agents have long been suspected to play a major role in the aetiology of a variety of human cancers. A model for the induction of bladder cancer associated with schistosomiasis is proposed which takes into account the interrelationships between different factors resulting from the infection, especially the role of alkylating agents that can contribute to the induction of this neoplasm. 相似文献
8.
9.
10.
Determination of hepatitis C virus genotype by Pyrosequencing 总被引:4,自引:0,他引:4
Elahi E Pourmand N Chaung R Rofoogaran A Boisver J Samimi-Rad K Davis RW Ronaghi M 《Journal of virological methods》2003,109(2):171-176
A simple sequencing-based assay is described for genotyping of hepatitis C virus (HCV). RT-PCR was employed to amplify a 237-nucleotide-long fragment from the 5' untranslated region (UTR) of the genome using one biotinylated and one normal primer. Subsequent to capture of the PCR products on streptavidin-coated beads, single-stranded DNA separation, and hybridization of sequencing primer, Pyrosequencing was performed. The genotype of 98 samples out of which 77 samples were from American veterans and 21 samples were from Iran was determined. The samples from the American veterans contained six different subtypes, while five subtypes were found in Iranian samples. For rapid population-specific HCV subtyping, a multiplex assay was developed. This study demonstrates the suitability of this technology for low-cost, high throughput and accurate microbial genotyping. 相似文献