全文获取类型
收费全文 | 2737篇 |
免费 | 196篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 85篇 |
妇产科学 | 64篇 |
基础医学 | 293篇 |
口腔科学 | 183篇 |
临床医学 | 259篇 |
内科学 | 575篇 |
皮肤病学 | 101篇 |
神经病学 | 154篇 |
特种医学 | 137篇 |
外科学 | 311篇 |
综合类 | 82篇 |
一般理论 | 4篇 |
预防医学 | 247篇 |
眼科学 | 138篇 |
药学 | 145篇 |
中国医学 | 12篇 |
肿瘤学 | 138篇 |
出版年
2023年 | 32篇 |
2022年 | 55篇 |
2021年 | 124篇 |
2020年 | 74篇 |
2019年 | 108篇 |
2018年 | 91篇 |
2017年 | 68篇 |
2016年 | 81篇 |
2015年 | 96篇 |
2014年 | 114篇 |
2013年 | 169篇 |
2012年 | 167篇 |
2011年 | 153篇 |
2010年 | 115篇 |
2009年 | 86篇 |
2008年 | 125篇 |
2007年 | 139篇 |
2006年 | 107篇 |
2005年 | 104篇 |
2004年 | 84篇 |
2003年 | 75篇 |
2002年 | 55篇 |
2001年 | 37篇 |
2000年 | 36篇 |
1999年 | 44篇 |
1998年 | 39篇 |
1997年 | 49篇 |
1996年 | 34篇 |
1995年 | 23篇 |
1994年 | 24篇 |
1993年 | 17篇 |
1992年 | 26篇 |
1991年 | 22篇 |
1990年 | 21篇 |
1989年 | 37篇 |
1988年 | 26篇 |
1987年 | 23篇 |
1986年 | 18篇 |
1985年 | 26篇 |
1984年 | 16篇 |
1983年 | 13篇 |
1982年 | 14篇 |
1981年 | 15篇 |
1980年 | 15篇 |
1979年 | 18篇 |
1978年 | 10篇 |
1977年 | 13篇 |
1975年 | 11篇 |
1971年 | 13篇 |
1969年 | 15篇 |
排序方式: 共有2948条查询结果,搜索用时 15 毫秒
91.
Autoantibody against erythrocyte protein 4.1 in a patient with autoimmune hemolytic anemia 总被引:1,自引:0,他引:1
Wakui H; Imai H; Kobayashi R; Itoh H; Notoya T; Yoshida K; Nakamoto Y; Miura AB 《Blood》1988,72(2):408-412
We observed the presence of a new autoantibody, anti-erythrocyte protein 4.1, in a patient with autoimmune hemolytic anemia (AIHA). Western blotting analysis revealed that IgG from the patient's plasma reacted with erythrocyte protein 4.1. However, among other patients with hemolytic diseases (six having AIHA and three each having either hereditary spherocytosis, elliptocytosis, or lead poisoning) as well as among control subjects, no antibody activity to protein 4.1 was observed. In addition to the anti-protein 4.1 antibody, two different kinds of anti-erythrocyte antibodies were detected by conventional serological studies in this patient. One of them was an anti-Ena-like antibody in the eluate from the patient's erythrocytes, while another was the anti-S-specific antibody in the plasma. An elution study and an absorption study using S antigen-positive erythrocytes demonstrated that the anti-protein 4.1 antibody differed from both the anti-Ena-like antibody and the anti-S antibody. Familial analysis of the patient revealed the same antibody in her brother, who did not have hemolytic anemia. These results demonstrate that anti-protein 4.1 antibody is considered to be included in the spectrum of anti-cytoskeleton autoantibodies, which have been observed in patients having increased cell lysis as well as in healthy subjects. 相似文献
92.
Deisseroth AB; Zu Z; Claxton D; Hanania EG; Fu S; Ellerson D; Goldberg L; Thomas M; Janicek K; Anderson WF 《Blood》1994,83(10):3068-3076
Relapse after autologous bone marrow transplantation for chronic myelogenous leukemia (CML) can be due either to the persistence of leukemia cells in systemic tissues following preparative therapy, or due to the persistence of leukemia cells in the autologous marrow used to restore marrow function after intensive therapy. To help distinguish between these two possible causes of relapse, we used safety-modified retroviruses, which contain the bacterial resistance gene NEO, to mark autologous marrow cells that had been collected from patients early in the phase of hematopoietic recovery after in vivo chemotherapy. The cells were then subjected to ex vivo CD34 selection following collection and 30% of the bone marrow were exposed to a safety-modified virus. This marrow was infused after delivery of systemic therapy, which consisted of total body irradiation (1,020 cGy), cyclophosphamide (120 mg/kg), and VP-16 (750 mg/m2). RT PCR assays specific for the bacterial NEO mRNA, which was coded for by the virus, and the bcr-abl mRNA showed that in two evaluable CML patients transplanted with marked cells, sufficient numbers of leukemia cells remained in the infused marrow to contribute to systemic relapse. In addition, both normal and leukemic cells positive for the retroviral transgenome persisted in the systemic circulation of the patients for at least 280 days posttransplant showing that the infused marrow was responsible for the return of hematopoiesis following the preparative therapy. This observation shows that it is possible to use a replication-incompetent safety-modified retrovirus in order to introduce DNA sequences into the hematopoietic cells of patients undergoing autologous bone marrow transplantation. Moreover, this data suggested that additional fractionation procedures will be necessary to reduce the probability of relapse after bone marrow transplantation in at least the advanced stages of the disease in CML patients undergoing autologous bone marrow transplantation procedures. 相似文献
93.
Marcelo F Vela Joel E Richter Farah Khandwala Eugene H Blackstone Don Wachsberger Mark E Baker Thomas W Rice 《Clinical gastroenterology and hepatology》2006,4(5):580-587
BACKGROUND & AIMS: Studies comparing long-term success after pneumatic dilatation (PD) and laparoscopic Heller myotomy (HM) are lacking. This study compares long-term outcome of PD (single dilatation and graded approach) and laparoscopic HM and identifies risk factors for treatment failure. METHODS: A cross-sectional follow-up evaluation of an achalasia cohort treated between 1994 and 2002 was followed-up for a mean of 3.1 years. There was a total of 106 patients treated by graded PD (1-3 dilatations with progressively larger balloons) and 73 patients treated by HM (20 had failed graded PD and crossed over to HM). A symptom assessment (structured telephone interview or clinic visit) was performed and patients were given freedom from alternative therapies to determine treatment outcome. Endoscopy, manometry, and timed barium esophagram were performed to determine the cause of treatment failure. RESULTS: The success of single PD was defined as freedom from additional PDs: 62% at 6 months and 28% at 6 years (risk factors for failure: younger age, male sex, wider esophagus, and poor emptying on posttreatment timed barium esophagram). Freedom from subsequent PDs increased with each dilatation (graded PD). The success of graded PD and HM, defined as dysphagia/regurgitation less than 3 times/wk or freedom from alternative treatment, was similar: 90% vs 89% at 6 months and 44% vs 57% at 6 years (no risk factors for failure were identified). Causes of symptom recurrence were incompletely treated achalasia (96% after PD vs 64% after HM) and gastroesophageal reflux disease (4% after PD vs 36% after HM). CONCLUSIONS: No treatment cures achalasia. Short- and long-term success is similar for graded PD and laparoscopic HM. Therapeutic success decreases steadily over time. Achalasia patients need careful long-term follow-up evaluation. 相似文献
94.
95.
96.
Breno Quintella Farah Raphael Mendes Ritti-Dias Polly Montgomery Gabriel Grizzo Cucato Andrew Gardner 《Arquivos brasileiros de cardiologia》2020,114(3):486
Background Non-supervised ground walking has been recommended for patients with symptomatic peripheral artery disease (PAD). However, the magnitude of the effort required by this activity and the characteristics of patients whose ground walking is more intense are unclear.Objectives To determine whether ground walking exceeds the ventilatory threshold (VT), a recognized marker of exercise intensity, in patients with symptomatic PAD.Methods Seventy patients (61.4% male and aged 40 to 85 years old) with symptomatic PAD were recruited. Patients performed a graded treadmill test for VT determination. Then, they were submitted to a 6-minute walk test so the achievement of VT during ground ambulation could be identified. Multiple logistic regression was conducted to identify predictors of VT achievement during the 6-minute walk test. The significance level was set at p < 0.05 for all analyses.Results Sixty percent of patients achieved VT during the 6-minute walk test. Women (OR = 0.18 and 95%CI = 0.05 to 0.64) and patients with higher cardiorespiratory fitness (OR = 0.56 and 95%CI = 0.40 to 0.77) were less likely to achieve VT during ground walking compared to men and patients with lower cardiorespiratory fitness, respectively.Conclusion More than half of patients with symptomatic PAD achieved VT during the 6-minute walk test. Women and patients with higher cardiorespiratory fitness are less likely to achieve VT during the 6-minute walk test, which indicates that ground walking may be more intense for this group. This should be considered when prescribing ground walking exercise for these patients. (Arq Bras Cardiol. 2020; 114(3):486-492) 相似文献
97.
98.
Nadeem Noor Mohammad khan Farah F. Jijina Amita S. Joshi Prajakta A. Gupte Rachana A. Chaturvedi 《Indian journal of hematology & blood transfusion》2014,30(1):21-23
A 26 year old lady came with intermittent fever since eight months. She also complained of abdominal pain and decreased appetite for six months. She had swelling of feet and distension of abdomen due to ascites since one month. There was history of jaundice one month back. On radiological examination, hepatomegaly with dilated portal vein, massive splenomegaly and ascites without any lymphadenopathy was noted. Chest X-ray was normal. Blood examination and bone marrow studies were inconclusive. We received her liver biopsy, which showed normal architecture and sinusoidal infiltration by a monomorphic population of small to intermediate sized lymphoid cells. Portal tracts were free of such infiltrate. These lymphoid cells were LCA, CD3, CD43 positive and negative for CD20, CD34, CD4, CD8 and c-kit. Based on all these features, a diagnosis of Hepatosplenic T cell lymphoma was made. She was treated symptomatically, however she died within two months of diagnosis. 相似文献
99.
100.
Anthony P. Lombardo PhD Jan E. Angus RN PhD Ruth Lowndes RN PhD Naomi Cechetto RN BScN Shamal Khattak Farah Ahmad PhD Arlene S. Bierman MD MS 《Health & social care in the community》2014,22(6):575-587
As part of a mixed methods study on women's access to the healthcare system in Ontario, Canada, we undertook a qualitative meta‐synthesis to better understand the contextual conditions under which women access healthcare. An earlier phase of the synthesis demonstrated a series of factors that complicate women's access to healthcare in Ontario. Here, we consider women's agency in responding to these factors. We used meta‐study methods to synthesise findings from qualitative studies published between January 2002 and December 2010. Studies were identified by searches of numerous databases, including CINAHL, MEDLINE, Scopus, Gender Studies Database and LGBT Life. Inclusion criteria included use of a qualitative research design; published in a peer‐reviewed journal during the specified time period; included a sample at least partially recruited in Ontario; included distinct findings for women participants; and in English language. Studies were included in the final sample after appraisals using a qualitative research appraisal tool. We found that women utilised a spectrum of responses to forces limiting access to healthcare: mobilising financial, social and interpersonal resources; living out shortfalls by making do, doing without, and emotional self‐management; and avoiding illness and maintaining health. Across the studies, women described their efforts to overcome challenges to accessing healthcare. However, there were evident limits to women's agency and many of their strategies represented temporary measures rather than viable long‐term solutions. While women can be resourceful and resilient in overcoming access disparities, systemic problems still need to be addressed. Women need to be involved in designing and implementing interventions to improve access to healthcare, and to address the root problems of these issues. 相似文献