全文获取类型
收费全文 | 295篇 |
免费 | 19篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 14篇 |
妇产科学 | 2篇 |
基础医学 | 35篇 |
口腔科学 | 18篇 |
临床医学 | 50篇 |
内科学 | 63篇 |
皮肤病学 | 3篇 |
神经病学 | 16篇 |
特种医学 | 13篇 |
外科学 | 22篇 |
综合类 | 6篇 |
预防医学 | 14篇 |
眼科学 | 3篇 |
药学 | 30篇 |
中国医学 | 1篇 |
肿瘤学 | 22篇 |
出版年
2023年 | 5篇 |
2022年 | 7篇 |
2021年 | 17篇 |
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 11篇 |
2017年 | 4篇 |
2016年 | 13篇 |
2015年 | 11篇 |
2014年 | 14篇 |
2013年 | 20篇 |
2012年 | 20篇 |
2011年 | 25篇 |
2010年 | 23篇 |
2009年 | 9篇 |
2008年 | 16篇 |
2007年 | 20篇 |
2006年 | 18篇 |
2005年 | 11篇 |
2004年 | 6篇 |
2003年 | 14篇 |
2002年 | 12篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有314条查询结果,搜索用时 15 毫秒
31.
Cases of congenital dyserythropoietic anemia (CDA) that do not conform to any of the three classical types often present diagnostic difficulties and are at risk of developing secondary hemochromatosis. Here, we report a case of a six year old boy with transfusion dependency and gross abnormalities of the erythroblasts. 相似文献
32.
33.
34.
Sabnavis Sowmya Aruna Ramaiah Tella Sunitha Pratibha Nallari Akka Jyothy Ananthapur Venkateshwari 《Inflammation》2014,37(4):1022-1027
—Preeclampsia is a severe complication of pregnancy characterized by an excessive maternal systemic inflammatory response with activation of both the innate and adaptive immune system. Interleukin-10 affects maternal intravascular inflammation, as well as endothelial dysfunction. The aim of the study was to investigate the association between IL-10 T-819 C polymorphism and preeclampsia. A total of 120 pregnant women with preeclampsia and 120 women with normal pregnancy attending the Gynecological Unit of Government Maternity Hospital, Petlaburz, Hyderabad, India, were considered for the present study. A standard amplification refractory mutation system (ARMS) PCR was carried out for genotyping of IL-10 T-819 C promoter polymorphism in all the participants. Genotypic distribution of the control and patient groups was compared with values predicted by the Hardy-Weinberg equilibrium using χ2 test. Odds ratios (OR) and their respective 95 % confidence intervals were used to measure the strength of association between IL-10 gene polymorphism and preeclampsia. The frequencies of IL-10 T-819 C genotypes, CC, CT, and TT, were 47.5, 28.3, and 24.2 % in women with preeclampsia and 20.8, 48.3, and 30.8 % in the controls, respectively. There is a significant difference in the distribution of genotypes and alleles of IL-10 T-819 C between the two groups (test power?=?0.66). The present study suggests that the IL-10 T-819 C gene promoter polymorphism can be a major genetic regulator in the etiology of preeclampsia 相似文献
35.
J Oral Pathol Med (2010) 39 : 223–229 Background: The aim of this study was to assess the expression, distribution and comparison of tenascin, a glycoprotein of the extracellular matrix in ameloblastoma and ameloblastic fibroma, both odontogenic neoplasms with diverse biological behavior and to understand the proliferative activity by using the morphometric analysis. Methods: Paraffin embedded tissue from 25 cases of odontogenic tumors i.e., ameloblastoma (n = 15) and ameloblastic fibroma (n = 10) were used. The expression of tenascin was evaluated using immunohistochemistry. Morphometric analysis of nucleolar organizer regions (NORs) from ameloblastoma and ameloblastic fibroma was carried out by silver staining. Results: A heterogeneous expression of tenascin was found in ameloblastoma which was mainly localized at the epithelial–mesenchymal interface and a patchy distribution was observed in the stroma (80%), while strong positivity was observed in the stroma and at the basement membrane zone of ameloblastic fibroma (100%). argyrophilic nucleolar organizer regions (AgNORs) revealed higher mean counts in ameloblastoma (3.093 ± 0.902) when compared with those of ameloblastic fibroma (1.553 ± 0.250). Ameloblastoma presented more than two NORs (two to five) per nucleus in majority of the cells, while ameloblastic fibroma exhibited only one NORs per nucleus. Conclusions: Expression of tenascin in these neoplasms suggest that it could play a role in epithelial‐ mesenchymal interaction, while AgNORs reveal that ameloblastomas are more aggressive when compared with ameloblastic fibromas. 相似文献
36.
Herbert Sandstrm Anders Wahlin Mikael Eriksson Ingmar Bergstrm Sunitha N. Wickramasinghe 《European journal of haematology》1994,52(1):42-46
Abstract: A family with congenital dyserythropoietic anaemia type III was studied. Twenty patients and 10 of their healthy siblings were clinically examined and questioned about their medical history. Blood sampling and bone marrow aspirations were also performed. Forty-five percent of the patients reported symptoms of anaemia and 35% regularly felt weakness, fatigue, or headache. However, the majority of the patients regarded themselves as healthy. The bone marrow showed a uniform picture of erythroid hyperplasia with multinuclear erythroblasts and gigantoblasts with up to 12 nuclei. There was laboratory evidence of intravascular haemolysis and mild anaemia. We also observed a high prevalence of monoclonal gammopathy of undetermined significance (3 cases) and myeloma (1 case) among the patients. 相似文献
37.
S. Chatterjee T. A. Sunitha A. Velayudhan S. Khanna 《Acta psychiatrica Scandinavica》1997,95(6):544-550
The aim of the present study was to explore a psychobiological perspective in the aetiology of social phobia. The emphasis was on serotonergic function and personality. A total of 20 social phobics according to ICD-10 DCR criteria were assessed with the Schedule for Clinical Assessment in Neuropsychiatry and the International Personality Disorder Examination. They were compared with an age-matched normal population with regard to scores on the Fear of Negative Evaluation Scale, the Social Avoidance and Distress Scale, the Temperament and Character Inventory, and platelet 5HT2 receptor function. Other Axis-I disorders and cluster C personality disorders were frequently encountered. The social phobia group was characterized by high levels of harm avoidance, and low levels of novelty seeking, co-operativeness and self-directedness. Platelet 5HT2 receptor density did not differentiate between the groups, but was associated with severity of social phobia. An integrated psychobiological model is presented. 相似文献
38.
Metformin-associated lactic acidosis (MALA) is a serious metabolic complication that occurs because of metformin accumulation in patients who become dehydrated or developed acute renal failure. Bicarbonate hemodialysis treatment should take place early in the course of management, especially in patients with severe metabolic acidosis who fail to respond to intravenous bicarbonate therapy or in whom renal failure is present. We report a case of MALA in which acute renal failure resulting from dehydration secondary to diarrhea and poor oral intake likely caused MALA. Early recognition of this condition and initiation of effective treatment can improve outcome. 相似文献
39.
Folate deficiency causes uracil misincorporation into human DNA
and chromosome breakage: Implications for cancer and neuronal damage 下载免费PDF全文
Benjamin C. Blount Matthew M. Mack Carol M. Wehr James T. MacGregor Robert A. Hiatt Gene Wang Sunitha N. Wickramasinghe Richard B. Everson Bruce N. Ames 《Proceedings of the National Academy of Sciences of the United States of America》1997,94(7):3290-3295
Folate deficiency causes massive incorporation of uracil into human DNA (4 million per cell) and chromosome breaks. The likely mechanism is the deficient methylation of dUMP to dTMP and subsequent incorporation of uracil into DNA by DNA polymerase. During repair of uracil in DNA, transient nicks are formed; two opposing nicks could lead to chromosome breaks. Both high DNA uracil levels and elevated micronucleus frequency (a measure of chromosome breaks) are reversed by folate administration. A significant proportion of the U.S. population has low folate levels, in the range associated with elevated uracil misincorporation and chromosome breaks. Such breaks could contribute to the increased risk of cancer and cognitive defects associated with folate deficiency in humans. 相似文献
40.
Schecter A Szabo DT Miller J Gent TL Malik-Bass N Petersen M Paepke O Colacino JA Hynan LS Harris TR Malla S Birnbaum LS 《Environmental health perspectives》2012,120(9):1260-1264
Background: Hexabromocyclododecane (HBCD) is a brominated flame retardant used in polystyrene foams in thermal insulation and electrical equipment. The HBCD commercial mixture consists mainly of α, β, and γ stereoisomers. Health concerns of HBCD exposure include alterations in immune and reproductive systems, neurotoxic effects, and endocrine disruption. Stereoisomer-specific levels of HBCD have not been measured previously in U.S. food.Objectives: We measured HBCD stereoisomer levels in U.S. foods from Dallas, Texas, supermarkets.Methods: Convenience samples of commonly consumed foods were purchased from supermarkets in Dallas in 2009-2010. Food samples included a wide variety of lipid-rich foods: fish, peanut butter, poultry, pork, and beef. Thirty-six individual food samples were collected in 2010 and analyzed for α-, β-, and γ-HBCD stereoisomers using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Ten pooled food samples previously collected in 2009 for a study of total HBCD levels using gas chromatography-mass spectrometry (GC-MS), were reanalyzed for α-, β-, and γ-HBCD stereoisomers using LC-MS/MS.Results: Of the 36 measured individual foods, 15 (42%) had detectable levels of HBCD. Median (ranges) of α- and γ-HBCD concentrations were 0.003 (< 0.005-1.307) and 0.005 (< 0.010-0.143) ng/g wet weight (ww), respectively; β-HBCD was present in three samples with a median (range) of 0.003 (< 0.005-0.019) ng/g ww. Median levels (range) for α-, β-, and γ-HBCD, in pooled samples were 0.077 (0.010-0.310), 0.008 (< 0.002-0.070), and 0.024 (0.012-0.170) ng/g ww, respectively.Conclusions: α-HBCD was detected most frequently and at highest concentrations, followed by γ-, and then β-HBCD, in food samples from Dallas, Texas. Food may be a substantial contributor to the elevated α-HBCD levels observed in humans. These data suggest that larger and more representative sampling should be conducted. 相似文献