全文获取类型
收费全文 | 2790篇 |
免费 | 226篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 104篇 |
妇产科学 | 112篇 |
基础医学 | 417篇 |
口腔科学 | 88篇 |
临床医学 | 347篇 |
内科学 | 553篇 |
皮肤病学 | 170篇 |
神经病学 | 154篇 |
特种医学 | 43篇 |
外科学 | 190篇 |
综合类 | 52篇 |
一般理论 | 4篇 |
预防医学 | 227篇 |
眼科学 | 71篇 |
药学 | 224篇 |
中国医学 | 50篇 |
肿瘤学 | 200篇 |
出版年
2024年 | 8篇 |
2023年 | 54篇 |
2022年 | 169篇 |
2021年 | 224篇 |
2020年 | 167篇 |
2019年 | 190篇 |
2018年 | 191篇 |
2017年 | 108篇 |
2016年 | 147篇 |
2015年 | 119篇 |
2014年 | 164篇 |
2013年 | 194篇 |
2012年 | 251篇 |
2011年 | 240篇 |
2010年 | 121篇 |
2009年 | 86篇 |
2008年 | 117篇 |
2007年 | 104篇 |
2006年 | 87篇 |
2005年 | 91篇 |
2004年 | 59篇 |
2003年 | 35篇 |
2002年 | 30篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 9篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 5篇 |
1987年 | 7篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1980年 | 1篇 |
1979年 | 4篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1973年 | 2篇 |
1936年 | 1篇 |
排序方式: 共有3027条查询结果,搜索用时 31 毫秒
81.
Zahra?MA?MohammedEmail author Donald?C?McMillan Joanne?Edwards Elizabeth?Mallon Julie?C?Doughty Clare?Orange James?J?Going 《BMC clinical pathology》2013,13(1):31
Background
Several well-established tumour prognostic factors are used to guide the clinical management of patients with breast cancer. Lymphovascular invasion and angiogenesis have also been reported to have some promise as prognostic factors. The aim of the present study was to examine the prognostic value of tumour lymphovascular invasion and microvessel density compared with that of established prognostic factors in invasive ductal breast cancer.Methods
In addition to hormone receptor status and Ki-67 proliferative activity, lymphovascular invasion and microvessel density and their relationship with survival were examined in patients with invasive ductal breast cancer. Full sections and tissue microarrays (n?=?384 patients) were utilised to assess these factors and were scored by appropriate methods.Results
On univariate analysis tumour size (P?<?0.05), lymph node involvement (P?<?0.01), lymphovascular invasion (P?<?0.05), microvessel density (P?<?0.05) and local- regional treatment (P?<?0.01) were associated with poorer survival in ER negative tumours. On multivariate analysis in ER negative tumours lymph node involvement (P?<?0.01) and local- regional treatment (P?<?0.05) were independently associated with poorer cancer-specific survival. On univariate analysis tumour grade (P?<?0.05), lymph node involvement (P?<?0.001), HER-2 (P?<?0.05), Ki-67 (P?<?0.01) and lymphovascular invasion (P?<?0.001) were associated with poorer survival in ER positive tumours. On multivariate analysis lymph node involvement (P?<?0.001), Ki-67 (P?<?0.001) and lymphovascular invasion (P?<?0.05) were independently associated with poorer cancer-specific survival in ER positive tumours.Conclusion
Lymphovascular invasion but not microvessel density was independently associated with poorer survival in patients with ER positive but not ER negative invasive ductal breast cancer.82.
Maryam Zarrabi Mohammadali Nazarinia Abbas Rahimi Jaberi Nasser Gholijani Zahra Amirghofran 《Medical principles and practice》2021,30(2):146
ObjectiveInterleukin (IL)-38 is a newly discovered member of the IL-1 cytokine family with a proposed anti-inflammatory profile. We studied the probable role of this cytokine in the pathogenesis of two autoimmune diseases: multiple sclerosis (MS) and systemic sclerosis (SSc).Subjects and MethodsA total of 87 MS patients and 86 SSc patients (40 new and recently untreated cases and 46 treated cases) were selected for this study. Eighty-seven and 80 age- and sex-matched healthy subjects were included as controls for MS and SSc, respectively. Clinical and paraclinical features of the patients were recorded at the time of sampling. Serum IL-38 was measured by ELISA.ResultsLevels of serum IL-38 did not significantly differ between the total MS or SSc patients compared to controls. However, levels of IL-38 were significantly higher in newly diagnosed patients of MS (206.43 ± 38.97 pg/mL, p < 0.0001) than in those previously treated (158.04 ± 39.45 pg/mL). Similarly, new/recently untreated cases of SSc patients showed increased IL-38 levels (185.19 ± 36.27 pg/mL, p = 0.001) compared to treated patients (166.82 ± 33.08 pg/mL). IL-38 levels in newly diagnosed MS patients (p = 0.007) and new/recently untreated SSc patients (p = 0.032) were significantly higher than those in healthy controls.ConclusionThe higher serum levels of IL-38 in new or recently untreated cases of MS and SSc patients than in treated patients and healthy controls suggest the possible role of this cytokine in the development of these diseases or as part of a feedback loop to attenuate the inflammatory conditions in early stages of these diseases. 相似文献
83.
Seyed Mojtaba Hosseini Attiyeh Vasaghi Newsha Nakhlparvar Reza Roshanravan Tahereh Talaei-khozani Zahra Razi 《中国神经再生研究》2015,10(8):1312-1316
Alginate scaffold has been considered as an appropriate biomaterial for promoting the differentiation of embryonic stem cells toward neuronal cell lineage. We hypothesized that alginate scaffold is suitable for culturing Wharton's jelly mesenchymal stem cells(WJMSCs) and can promote the differentiation of WJMSCs into neuron-like cells. In this study, we cultured WJMSCs in a three-dimensional scaffold fabricated by 0.25% alginate and 50 m M Ca Cl2 in the presence of neurogenic medium containing 10 μM retinoic acid and 20 ng/m L basic fibroblast growth factor. These cells were also cultured in conventional two-dimensional culture condition in the presence of neurogenic medium as controls. After 10 days, immunofluorescence staining was performed for detecting β-tubulin(marker for WJMSCs-differentiated neuron) and CD271(motor neuron marker). β-Tubulin and CD271 expression levels were significantly greater in the WJMSCs cultured in the three-dimensional alginate scaffold than in the conventional two-dimensional culture condition. These findings suggest that three-dimensional alginate scaffold cell culture system can induce neuronal differentiation of WJMSCs effectively. 相似文献
84.
Seyed Mojtaba Hosseini Mohammad Farahmandnia Zahra Razi Somayeh Delavarifar Benafsheh Shakibajahromi 《中国神经再生研究》2015,10(6):904-908
Cell therapy using stem cell transplantation against cerebral ischemia has been reported. However, it remains controversial regarding the optimal time for cell transplantation and the transplantation route. Rat models of cerebral ischemia were established by occlusion of the middle cerebral artery. At 1, 12 hours, 1, 3, 5 and 7 days after cerebral ischemia, bone marrow mesenchymal stem cells were injected via the tail vein. At 28 days after cerebral ischemia, rat neurological function was evaluated using a 6-point grading scale and the pathological change of ischemic cerebral tissue was observed by hematoxylin-eosin staining. Under the fluorescence microscope, the migration of bone marrow mesenchymal stem cells was examined by PKH labeling. Caspase-3 activity was measured using spectrophotometry. The optimal neurological function recovery, lowest degree of ischemic cerebral damage, greatest number of bone marrow mesenchymal stem cells migrating to peri-ischemic area, and lowest caspase-3 activity in the ischemic cerebral tissue were observed in rats that underwent bone marrow mesenchymal stem cell transplantation at 12 hours after cerebral ischemia. These findings suggest that 12 hours after cerebral ischemia is the optimal time for tail vein injection of bone marrow mesenchymal stem cell transplantation against cerebral ischemia, and the strongest neuroprotective effect of this cell therapy appears at this time. 相似文献
85.
86.
Sima Rostami Shams Shariat Torbaghan Shahriar Dabiri Zahra Babaei Mohammad Ali Mohammadi Mitra Sharbatkhori Majid Fasihi Harandi 《The American journal of tropical medicine and hygiene》2015,92(3):588-594
Cystic echinococcosis (CE), caused by the larval stage of Echinococcus granulosus, presents an important medical and veterinary problem globally, including that in Iran. Different genotypes of E. granulosus have been reported from human isolates worldwide. This study identifies the genotype of the parasite responsible for human hydatidosis in three provinces of Iran using formalin-fixed paraffin-embedded tissue samples. In this study, 200 formalin-fixed paraffin-embedded tissue samples from human CE cases were collected from Alborz, Tehran, and Kerman provinces. Polymerase chain reaction amplification and sequencing of the partial mitochondrial cytochrome c oxidase subunit 1 gene were performed for genetic characterization of the samples. Phylogenetic analysis of the isolates from this study and reference sequences of different genotypes was done using a maximum likelihood method. In total, 54.4%, 0.8%, 1%, and 40.8% of the samples were identified as the G1, G2, G3, and G6 genotypes, respectively. The findings of the current study confirm the G1 genotype (sheep strain) to be the most prevalent genotype involved in human CE cases in Iran and indicates the high prevalence of the G6 genotype with a high infectivity for humans. Furthermore, this study illustrates the first documented human CE case in Iran infected with the G2 genotype. 相似文献
87.
Zahra Khazaeipour Seyedeh-Mohadeseh Taheri-Otaghsara Maryam Naghdi 《Topics in spinal cord injury rehabilitation》2015,21(2):149-155
Background:
Depression is a common psychological problem that decreases life satisfaction and quality of life in people with spinal cord injury (SCI).Objective:
The aim of this study was to investigate the prevalence of depression after SCI and its association with pathophysiological, demographic, and socioeconomic factors, including sex, age, level of injury, financial status, and suicidal thoughts.Methods:
This was a cross-sectional study of 134 adults (≥18 years old) with SCI who were referred to the Brain and Spinal Cord Injury Research Center (BASIR) clinic, Tehran University of Medical Sciences, for outpatient rehabilitation. The Beck Depression Inventory (BDI-II Persian), a 21-question multiple-choice inventory, was used to measure the presence and severity of depression. Data were collected by interview.Results:
Sixty-six (49.3%) participants had mild to severe depression. There was a higher probability of depression in individuals with SCI who were female, had tetraplegia, had suicidal thoughts, had a history of suicide attempt, had a low education level, or were taken cared for by a family member other than a spouse or parents.Conclusion:
Depression was highly prevalent in individuals with SCI and was related to some demographic, pathophysiological, and socioeconomic indicators. The primary predictive indicators and the factors influencing depression should be determined to provide early detection and timely treatment to prevent more complications and improve quality of life for individuals with SCI. 相似文献88.
Majid Haghjoo MD Mehrdad Saravi MD Mohammad Jafar Hashemi MD Saeid Hosseini MD Nader Givtaj MD Mohammad Hassan Ghafarinejad MD Amir Jamshid Khamoushi MD Zahra Emkanjoo MD Amir Farjam Fazelifar MD Abolfath Alizadeh MD Mohammad Ali Sadr-Ameli MD 《Heart rhythm》2007,4(9):1170-1174
BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmia after coronary artery bypass graft (CABG) surgery. It has been shown that prophylactic oral beta-blocker administration reduces the incidence of post-CABG AF. However, the optimal beta-blocker has not been identified. OBJECTIVE: This study sought to determine whether oral carvedilol (with its unique anti-inflammatory and antioxidant properties) is more effective than oral metoprolol for prevention of AF after CABG surgery. METHODS: Between April 2006 and December 2006, 120 patients (63 men, mean age 61 +/- 9.4 years) who were scheduled to undergo their first on-pump CABG were enrolled in this study. The patients were randomized in a prospective 1:1 manner to receive either oral carvedilol (n = 60) or oral metoprolol (n = 60). The end point of the study was the occurrence of the new-onset AF during the first 5 days after CABG. RESULTS: AF occurred in 29 of 120 patients (24.0%). The incidence of postoperative AF was 15.0% (9 of 60) in the carvedilol group and 33% (20 of 60) in the metoprolol group (P = .022). The carvedilol group was treated with mean daily dose of 46 +/- 9 mg and metoprolol group with mean daily dose of 93 +/- 11 mg. There were no differences between the study groups regarding any known preoperative, perioperative, or postoperative characteristics (all values were P >.05). No significant adverse effect was observed in either group. CONCLUSION: This prospective study suggested that oral carvedilol is more effective than oral metoprolol in the prevention of AF after on-pump CABG. It is well tolerated when started before and continued after the surgery. However, further prospective studies are needed to clarify this issue. 相似文献
89.
Karimi M Hadi Imanieh M Ghiam AF Hashemi Z 《European journal of gastroenterology & hepatology》2005,17(12):1363-1367
BACKGROUND: Recurrent abdominal pain (RAP) affects many children, especially those affected by beta-thalassaemia major. The role of Helicobacter pylori is still unclear in children with RAP. OBJECTIVES: The aim of the present study was the comparison of beta-thalassaemia major patients and normal controls with RAP in H. pylori infection. The factors influencing H. pylori prevalence were also investigated. METHODS: A series of 50 beta-thalassaemia major cases (30 female, 20 male; aged 6-25 years) and 50 age-matched and sex-matched controls, both presenting with RAP, were recruited during a period of 18 months. The study participants were obtained through a multistage random sampling method among those that met Apley's criteria. All the patients and controls had undergone diagnostic oesophagogastroduodenoscopy with biopsy. H. pylori infection was confirmed by two histopathological examinations on an endoscopy sample and a rapid urease test. RESULTS: H. pylori infection in thalassaemic patients was more common than in controls [34/50 (68%) versus 30/50 (60%)], but this higher frequency was not statistically significant. A clear relationship was found between the prevalence of H. pylori and age, duration of transfusion/chelation programmes, pain duration and splenectomy. In contrast, H. pylori did not correlate with abdominal pain characteristics, blood group, serum ferritin level and pathology of the upper gastrointestinal tract. The most frequent endoscopy abnormality was gastritis (72%). Nausea and heartburn were the leading associated symptoms. CONCLUSION: The high prevalence of H. pylori infection suggests that H. pylori should be remembered as a probable cause of RAP in beta-thalassaemia major patients. 相似文献
90.