首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   868篇
  免费   48篇
  国内免费   28篇
耳鼻咽喉   24篇
儿科学   29篇
妇产科学   36篇
基础医学   70篇
口腔科学   13篇
临床医学   94篇
内科学   166篇
皮肤病学   17篇
神经病学   23篇
特种医学   48篇
外科学   137篇
综合类   63篇
预防医学   32篇
眼科学   1篇
药学   23篇
中国医学   7篇
肿瘤学   161篇
  2023年   15篇
  2022年   41篇
  2021年   39篇
  2020年   28篇
  2019年   32篇
  2018年   39篇
  2017年   28篇
  2016年   28篇
  2015年   33篇
  2014年   68篇
  2013年   75篇
  2012年   40篇
  2011年   55篇
  2010年   28篇
  2009年   34篇
  2008年   40篇
  2007年   43篇
  2006年   39篇
  2005年   30篇
  2004年   25篇
  2003年   16篇
  2002年   11篇
  2001年   14篇
  2000年   16篇
  1999年   12篇
  1998年   12篇
  1997年   5篇
  1996年   9篇
  1995年   10篇
  1994年   9篇
  1993年   13篇
  1992年   5篇
  1991年   7篇
  1990年   6篇
  1989年   4篇
  1988年   1篇
  1987年   4篇
  1986年   3篇
  1985年   3篇
  1984年   6篇
  1982年   2篇
  1981年   4篇
  1980年   3篇
  1979年   1篇
  1978年   4篇
  1977年   1篇
  1973年   1篇
  1972年   2篇
排序方式: 共有944条查询结果,搜索用时 15 毫秒
1.
2.
回盲部恶性肿瘤的诊治   总被引:1,自引:0,他引:1  
目的:分析回盲部恶性肿瘤的诊断和治疗过程,总结经验.以期提高早期确诊率和患者生存率。方法:回顾性分析近5年53例住院治疗的回盲部恶性肿瘤患者的临床资料。结果:53例患者中腺癌、黏液腺癌50例,恶性淋巴瘤3例。首次确诊率为75.5%。误诊或延迟诊断的疾病主要为阑尾炎、阑尾脓肿,胆囊炎、胆石症、下消化道出血、贫血待查等。结论:60岁以上的老年患者为回盲部恶性肿瘤的主要人群,肿瘤类型主要为腺癌。尽管首发症状缺乏特异性,但提高警觉性,详细询问病史,通过大便隐血试验、钡灌肠或气钡双重造影、纤维结肠镜检查仍能有效的提高首次确诊率,积极手术冶疗,可显著改善患者的预后。  相似文献   
3.
Diabetic control after total pancreatectomy   总被引:3,自引:0,他引:3  
BACKGROUND: Diabetes after total pancreatectomy is commonly described as 'brittle' with most series reporting outcomes after resection for pancreatitis alone. The aim of this study was to determine glycaemic control in patients resected for benign and malignant disease. METHODS: A retrospective analysis of all patients undergoing total pancreatectomy (1989-2003) from a single institution was done. Data of diabetic control were obtained from case notes, general practitioners and telephonic consultation. Comparison was made against a matched type 1 diabetic population. RESULTS: Forty-seven patients with a median age of 59 years (range 17-85 years) and median follow-up of 50 months (range 5-136 months) were identified. Thirty-five underwent primary resection with 11 receiving completion procedures. Thirty were for malignancy (19 deceased) and 17 for benign/indeterminate histology (2 deceased). Thirty-three patients were available for detailed follow-up. There was no significant difference between median HbA(1c) of the study group and the control (8.2% versus 8.1%). The majority of patients reported diabetic control and daily performance as excellent or good. Resection for pancreatitis gave poorer subjective control (p < 0.05) than those resected for malignancy. Two patients required in-patient treatment for diabetic complications, with no deaths related to diabetes observed. CONCLUSION: Diabetes after total pancreatectomy is not necessarily associated with poor glycaemic control and in the majority results in equivalent biochemical control compared to a normal type 1 diabetic population.  相似文献   
4.
The relationship between the histological grade of dedifferentiation of thyroid cancer and estrogen receptors (ER) was examined immunohistochemically. Thyroid cancers were from postmenopausal females of almost the same mean age (69-73 years old) and within the same period of time (1974–1983). ER immunoreactivity located in the nucleus of the epithelium was found in all 6 well differentiated papillary cancers, and 5 of them (83.3%) showed ER-immunoreactive (ER-IR) cells amounting to 20 or more per visual field (x 100) under a light microscope. Of the 6 cases of poorly differentiated papillary cancer, 5 (83.3%) had 1-19 ER-IR cells per visual field. ER-IR cells were negative in 5 out of 6 cases (83.3%) of anaplastic cancers. Thus, the number of ER-IR cells tended to decrease with the degree of atypism of thyroid cancer (P < 0.001).  相似文献   
5.
Histoplasmosis is a rarely reported deep mycotic infection in the Indian context. Oral or oropharyngeal manifestation can occur as an isolated symptom or as part of a disseminated process associated with immunosuppression especially with HIV and diabetes. Five cases of head and neck histoplasmosis accrued over 6 years in a tertiary referral cancer institute were reviewed. All these patients presented clinically as cancer. In three patients, the marked pseudoepitheliomatous hyperplasia led to a mistaken biopsy diagnosis of malignancy following which definitive surgical treatment was performed. The subsequent excision revealed typical features of histoplasmosis. Isolated oral presentation of histoplasmosis can mimic malignancy both clinically as well as pathologically, leading to potentially disastrous consequences. A high index of suspicion in those with overt or hidden immunosuppression and a deep wedge biopsy to demonstrate the organisms in the subepithelial tissue is recommended. This work has been presented in the “Slide seminar on Infections and Infestations” in the IAP-ID pre conference CME in APCON 2006.  相似文献   
6.
Summary In various primary brain tumours of neuroepithelial tissue recombinant DNA techniques were used to demonstrate changes of the epidermal growth factor receptor gene, which is homologous to the c-erbB oncogene. Twenty-one of 40 grade III/IV tumours, but only 1 of 16 grade I/II tumours were found to contain amplified and/or rearranged c-erbB sequences. This highly significant difference suggest that c-erbB amplification, rearrangement, or both, are important steps in malignant transformation in a subset of patients with neuroepithelial tumours.  相似文献   
7.
本文报告了手术治疗肝外恶性梗阻性黄疸212例。根据B超(BUS)检查结果与术中所见进行对照研究,认为BUS对肝外恶性梗阻性黄疸与内科黄疸的鉴别诊断(正确率99%)、梗阻部位的定位(准确率95.3%),提供了可靠的依据;对恶性梗阻性黄疸的病因诊断仍不理想(阳性率59.4%)。因此BUS检查应列为常规或首选方法,对于确诊或定性有困难者,再选用ERCP或PTC。  相似文献   
8.
Summary Polyploidy — the doubling of chromosome sets of cells caused by a stop of mitosis at different levels of the mitotic cycle — is a phenomenon widely observed in plants, protozoa, metazoa, and animals. In man obligate polyploid tissues are found in liver parenchyma, heart muscle cells, and bone marrow megakaryocytes. Polyploidy occurs mostly in stable and highly differentiated cells and tissues. Besides age, stimulation of proliferation and increased metabolic function lead to polyploidization in these organs. Aneuploidy, however, is exclusively found in tumor cells.Megakaryocyte differentiation and polyploidy are controlled by thrombopoietin-like activities, of which the loci of production are still unknown. Megakaryocytes are unique among polyploid mammal cells. On the precursor level they maintain their proliferative activity independently of the mammal's age. Once having entered the incomplete mitotic cycle they stop cytokinesis and develop into highly polyploid cells. Polyploidization of megakaryocytes is the basic requirement for establishing highly effective hemostasis in mammals, which exhibit blood circulation based on high blood pressures.Every polyploidization results in increased production of membrane materials with which the platelet becomes endowed. By shedding cytoplasmic fragments approximately 3000 platelets are set free from a 32c megakaryocyte, compared with only 16 nucleated thrombocytes by mitotic division. There is further evidence that the heterogeneity of platelets mostly depends on the different polyploidy classes of the megakaryocytes from which they are derived. Changes in the polyploidy pattern of megakaryocytes could therefore have consequences for hemostatic disorders in several human diseases, particularly in malignancy.Abbreviations n haploid chromosome set (number of chromosomes actually counted) - c haploid DNA content (measured by cytophotometry) - M mitosis - C-Mitosis colchicine mitosis - G0, G1, G2, S phases of the mitotic cycle - Meg CSF megakaryocyte colony stimulating factor(s) - TSF thrombocytopoiesis stimulating factor(s) - CFU-Meg megakaryocyte colony forming unit This work was supported by Deutsche Forschungsgemeinschaft, grant Wi 806/1-1  相似文献   
9.
IntroductionAbdominal wall endometrioma (AWE) is a rare encountered condition with a prevalence of 1–2%. Multiple diagnostic and treatment modalities are available; however, no clear guidelines exist. On occasions muscle and fascia excision might be necessary to achieve a clear margin. To avoid mesh complications, we believe the treatment should depend on tumor location in relation to the abdominal wall fascia. As far as we know this approach has not been previously discussed.PresentationA 29-year old female with a surgical history of 3 C-sections presented to us with 6 months of cyclical abdominal pain in the left lower quadrant. Imaging studies confirmed the presence of a mass overlying the left lower rectus abdominis muscle. After imaging studies, the mass was surgically excised. Pathology confirmed a benign endometrioma.DiscussionUnfortunately, the surgical literature has not established a consensus on the best approach for diagnosis and management of this condition. The purpose of this report is to not only to present another case of this rare phenomenon, but to address the need for guidelines and review the current diagnostic and treatment available options. We also attempt to increase the awareness of this condition, it’s unlikely malignant degeneration and potential morbidity of surgical excision.ConclusionSurgical excision remains the standard of care for AWEs. In those patients where the fascia and muscle must be excised, we recommend less invasive modalities to avoid mesh complications. The need for guidelines remains.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号