全文获取类型
收费全文 | 1743篇 |
免费 | 127篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 102篇 |
妇产科学 | 20篇 |
基础医学 | 201篇 |
口腔科学 | 41篇 |
临床医学 | 142篇 |
内科学 | 396篇 |
皮肤病学 | 35篇 |
神经病学 | 93篇 |
特种医学 | 270篇 |
外科学 | 182篇 |
综合类 | 59篇 |
预防医学 | 88篇 |
眼科学 | 23篇 |
药学 | 69篇 |
中国医学 | 9篇 |
肿瘤学 | 136篇 |
出版年
2021年 | 12篇 |
2020年 | 10篇 |
2019年 | 18篇 |
2018年 | 47篇 |
2017年 | 32篇 |
2016年 | 15篇 |
2015年 | 32篇 |
2014年 | 56篇 |
2013年 | 84篇 |
2012年 | 56篇 |
2011年 | 56篇 |
2010年 | 44篇 |
2009年 | 74篇 |
2008年 | 57篇 |
2007年 | 81篇 |
2006年 | 44篇 |
2005年 | 47篇 |
2004年 | 52篇 |
2003年 | 35篇 |
2002年 | 49篇 |
2001年 | 27篇 |
2000年 | 36篇 |
1999年 | 32篇 |
1998年 | 82篇 |
1997年 | 59篇 |
1996年 | 70篇 |
1995年 | 49篇 |
1994年 | 57篇 |
1993年 | 53篇 |
1992年 | 24篇 |
1991年 | 16篇 |
1990年 | 26篇 |
1989年 | 48篇 |
1988年 | 36篇 |
1987年 | 33篇 |
1986年 | 38篇 |
1985年 | 26篇 |
1984年 | 23篇 |
1983年 | 25篇 |
1982年 | 17篇 |
1981年 | 26篇 |
1980年 | 15篇 |
1979年 | 18篇 |
1978年 | 10篇 |
1977年 | 18篇 |
1976年 | 14篇 |
1975年 | 20篇 |
1973年 | 10篇 |
1970年 | 14篇 |
1969年 | 11篇 |
排序方式: 共有1879条查询结果,搜索用时 0 毫秒
61.
BACKGROUND & AIMS: The functional significance of intestinal hyperplasia stimulated by insulin-like growth factor (IGF)-I is unclear and has not been studied in a model of mucosal atrophy induced by total parenteral nutrition (TPN). The aim of this study was to determine how IGF-I affects intestinal structure and epithelial function in the absence of luminal nutrition caused by TPN. METHODS: Rats were maintained with TPN with or without IGF-I (800 micrograms/day), and jejunal histology and epithelial ion transport were measured after 5 days. In a third TPN group without IGF-I, a short-term dose of IGF-I was added during in vitro flux chamber experiments. RESULTS: Rats given TPN with IGF-I had greater jejunal mucosal weight, greater protein and DNA content, and increased villus height and crypt depth compared with rats given TPN only. TPN increased ionic permeability and ion transport responses to secretory and absorptive agents. IGF-I in vivo reversed most of these changes; IGF-I in vitro enhanced sodium-dependent glucose absorption but had no other effects. CONCLUSIONS: Coinfusion of recombinant human IGF-I with TPN solution stimulates intestinal hyperplasia and attenuates transport changes induced by TPN. The latter effect seems to be primarily associated with the growth state of the epithelium. (Gastroenterology 1996 Dec;111(6):1501-8) 相似文献
62.
Corzo D; Yunis JJ; Salazar M; Lieberman JA; Howard A; Awdeh Z; Alper CA; Yunis EJ 《Blood》1995,86(10):3835-3840
Genes of the major histocompatibility complex (MHC) have been associated with susceptibility to drug-induced adverse reactions. We previously found that clozapine-induced agranulocytosis (CA) is associated with the HLA-DRB1*0402, DRB4*0101, DQB1*0302, DQA1*0301 haplotype in Ashkenazi Jewish patients and with the HLA-DRB1*1601, DRB5*02, DQB1*0502, DQA1*0102 haplotype in non-Jewish patients. In the present study, we tested the hypothesis that the variants of the heat- shock protein 70 (HSP-70) encoded by the HSP-70 loci located within the MHC region and known to be involved in apoptosis and regulation of cell proliferation could play an important role in molecular mechanisms of CA. First, we analyzed HSP70-2 polymorphism in risk-associated haplotypes from HLA homozygous cells and normal individuals and confirmed that the HSP70-2 9-kb variant was associated invariably with DR4 (HLA-DRB1*0402, DQB1*0302) and DR2 (HLA-DRB1*01601, DQB1*0502, DQA1*0102 and HLA-DRB1*1501, DQB1*0602) haplotypes, which were the haplotypes found increased in Jewish and non-Jewish patients with CA, respectively. The 9.0-kb variant was also found to be associated with HLA-B44, DRB1*0401 and HLA-B44, DRB1*07 haplotypes. Second, in patients with CA (12 Ashkenazi Jewish and 20 non-Jewish patients), HSP70-1 A and HSP70-2 9.0-kb variants were associated with the MHC haplotypes found by us to be markers of susceptibility to CA. The clozapine-treated control group had an excess number of HSP70-1 C and HSP70-2 8.5-kb variants, consistent with genetic resistance to CA associated with those variants. This finding supports our hypothesis that a dominant gene within the MHC region (marked by HSP70-1 and HSP70-2), but not necessarily HLA, is associated with CA in two different ethnic groups. 相似文献
63.
64.
65.
CA Tan D. del Gaudio M.A. Dempsey K. Arndt S. Botes A. Reeder S. Das 《Clinical genetics》2014,85(4):353-358
Primary Autosomal Recessive Microcephaly (MCPH) is characterized by congenital microcephaly usually without additional clinical findings. The most common gene implicated in MCPH is ASPM and a large percentage of mutations described have been homozygous and in consanguineous families primarily of East Asian and Middle Eastern origin. ASPM sequencing was performed on 400 patients between the years 2009 and 2012. Seventy of the patient samples were also analyzed for copy number changes in the ASPM gene. Forty protein truncating mutations, including 29 novel mutations, were identified in 39 patients with MCPH. Approximately one third of patients were compound heterozygotes, indicative of non‐consanguinity in these patients. In addition, 46 non‐synonymous variants were identified and interpreted as variants of uncertain significance. No deletion/duplication in ASPM was identified in the patients analyzed. A wide ethnic distribution was observed, including the first reported patients with ASPM‐related MCPH of Hispanic descent. Clinical information was collected for 26 of the ASPM‐positive patients and 41 of the ASPM‐negative patients. As more individuals are identified with MCPH, we anticipate that we will continue to identify ASPM mutation‐positive patients from all ethnic origins supporting the occurrence of this genetic condition beyond that of consanguineous families of certain ethnic populations. 相似文献
66.
Flora Maria Lorenzo Fortes Ney Boa Sorte Victor D Mariano La la D Andrade Fernanda A Oliveira Monique CA Santos Cl udia Ivanilda N dos Santos Catharina A Passos Mila P Pacheco Valdiana C Surlo Neog lia P de Almeida Jaciane AM Fontes r a M Pimentel Raquel Rocha Genoile Oliveira Santana 《World journal of gastroenterology : WJG》2020,26(44):6993-7004
BACKGROUNDThere has been an increase in cases of inflammatory bowel disease (IBD) in recent years. There is also greater access and availability of immunosuppressive and biological agents, which increase the risk of opportunistic infection despite improving the quality of life and promoting mucosal healing. Tuberculosis (TB) remains a public health problem, and it has a high incidence in several countries. Therefore, knowledge of the risk of developing TB in patients with IBD is important.AIMTo evaluate the risk of active TB in patients with IBD under treatment from an endemic area in Latin America.METHODSA standard questionnaire included demographic variables, clinical aspects of IBD disease, history of active TB during treatment, active TB characteristics and evolution, initial screening and results and time from the start of anti-tumor necrosis factor alpha (TNFα) to TB development.RESULTSAzathioprine, anti-TNFα and the combination of these two drugs were associated with a higher risk of active TB incidence. The TNFα blockers increased the relative risk of developing active TB compared to other treatments. All four multivariable models showed that the use of TNFα blockers alone or in combination with azathioprine was an important risk factor for the incidence of active TB. After adjustment for sex, age, type of IBD and latent TB, anti-TNFα with azathioprine increased the relative risk to 17.8 times more than conventional treatment. Late TB, which was diagnosed 3 mo after the start of anti-TNFα, was the most frequent.CONCLUSIONTreatment with anti-TNFα increased the risk of active TB in IBD patients from an endemic area in Latin America. This risk was increased when anti-TNFα was combined with azathioprine. The time from the beginning of the treatment to the active TB diagnosis suggests a new TB infection. 相似文献
67.
68.
69.
目的探讨金属对金属(金对金)大头径假体微创全髋关节置换术(THA)治疗青中年股骨头坏死Ⅲ、Ⅳ期的临床疗效。方法本组32例(35髋)青中年股骨头缺血性坏死Ⅲ、Ⅳ期患者,年龄24~59岁,平均45岁,术前髋关节Harris评分平均(37.9±7.5)分;以改良后外侧小切口、肌间隙人路、充分保留关节动力性组织结构为特征的金对金大头径微创THA治疗。术中严格采取正确的假体植入技术,术中保留完整的软骨下骨和髋臼横韧带,击入臼杯时一次性安装成功,正确运用万古霉素预防感染。术后口服利伐沙班片抗凝,术后12h开放负压引流及卧床行功能锻炼,术后第2天拔除引流管后扶拐下地部分负重行走,术后2—3周患者即可弃拐完全负重行走。结果本组32例35髋患者均获随访,随访时间为12个月~6年,平均为4年。所有患者切口均一期愈合,无深静脉血栓形成、关节脱位、坐骨神经损伤、髋臼及股骨疲劳骨折、关节疼痛等严重并发症,X线片示髋关节假体位置均良好,无松动、移位、股骨柄下沉、假体周围骨折等表现。末次随访Harris评分由术前平均(37.9±7.5)分,提高至术后平均(92.2±4.6)分,前后比较有统计学意义(t=44.341,P〈0.05)。所有患者末次随访时髋关节功能明显优于术前,均对治疗效果满意,完全恢复正常生活及工作。结论采用金对金大头径微创THA治疗青中年股骨头坏死Ⅲ、Ⅳ期患者,能够明显降低手术风险,缩短卧床时问,迅速恢复髋关节功能,减少手术并发症,取得了满意的近期临床疗效。随着基础和临床研究的不断深入,金对金大头径髋关节假体的长期疗效还需要进一步探讨。 相似文献
70.
目的提高对巨大前列腺囊腺瘤的认识。方法回顾性分析收治的1例巨大前列腺囊腺瘤并成功进行腹腔镜切除的临床资料,结合文献复习进行讨论。结果本例患者成功行腹腔镜完整切除,手术时间125min,出血量60ml,术中双侧精囊输精管完整保留,术后会阴部坠胀不适消失,复查精液常规精子数目及活动度正常。已随诊12个月,肿瘤无复发。结论巨大前列腺囊腺瘤罕见,最终确诊要依靠病理诊断,其最有效的治疗是手术完整切除,而腹腔镜途径可作为完整切除的微创手段。 相似文献