全文获取类型
收费全文 | 4109篇 |
免费 | 174篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 154篇 |
儿科学 | 241篇 |
妇产科学 | 209篇 |
基础医学 | 341篇 |
口腔科学 | 110篇 |
临床医学 | 326篇 |
内科学 | 1017篇 |
皮肤病学 | 138篇 |
神经病学 | 270篇 |
特种医学 | 151篇 |
外科学 | 662篇 |
综合类 | 71篇 |
预防医学 | 91篇 |
眼科学 | 162篇 |
药学 | 137篇 |
中国医学 | 8篇 |
肿瘤学 | 237篇 |
出版年
2024年 | 5篇 |
2023年 | 31篇 |
2022年 | 51篇 |
2021年 | 95篇 |
2020年 | 73篇 |
2019年 | 82篇 |
2018年 | 117篇 |
2017年 | 86篇 |
2016年 | 148篇 |
2015年 | 177篇 |
2014年 | 188篇 |
2013年 | 231篇 |
2012年 | 328篇 |
2011年 | 350篇 |
2010年 | 175篇 |
2009年 | 155篇 |
2008年 | 346篇 |
2007年 | 361篇 |
2006年 | 331篇 |
2005年 | 277篇 |
2004年 | 249篇 |
2003年 | 184篇 |
2002年 | 154篇 |
2001年 | 26篇 |
2000年 | 18篇 |
1999年 | 16篇 |
1998年 | 13篇 |
1997年 | 7篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有4325条查询结果,搜索用时 0 毫秒
1.
Senem Maral Muradiye Acar Ozlem Sahin Balcik Eyyup Uctepe Omer Faruk Hatipoglu Derya Akdeniz Hatice Uludag Altun Ali Kosar Mehmet Gunduz Esra Gunduz 《Medicine》2015,94(16)
Chronic myeloproliferative disorders such as polycythemia vera (PV), essential thrombocytosis (ET), and idiopathic myelofibrosis arise from clonal proliferation of neoplastic stem cells in the bone marrow. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that have potential to degrade all types of extracellular matrix (ECM) and also play a role in remodeling of the ECM. It is known that MMPs play a role in bone marrow remodeling.The primary goal of our study is to explore the relationship between chronic myeloproliferative diseases and some of MMP gene polymorphisms. The demonstration of a relationship will help to understand whether these polymorphisms may be a potential early diagnosis marker of the diseases.Patients were selected from outpatient clinics of Turgut Ozal University Hospital, Ankara, Turkey, between December 2010 and May 2011. Twenty-eight patients that previously diagnosed and followed-up with PV, 17 with secondary polycythemia (SP), and 12 with ET were enrolled in the study, along with a control group of 22 healthy people.DNA was isolated from peripheral blood. Using polymerase chain reaction–restriction fragment length polymorphism method, MMP2 and MMP9 gene polymorphisms were analyzed with agarose gel electrophoresis. There was a statistically significant difference between the study groups and the control group in terms of Gln279Arg polymorphisms rates of MMP9. The highest MMP9 Gln279Arg polymorphism rate was observed in the ET group. But nobody from the control group had polymorphic MMP9. There was no statistically significant difference between the groups in terms of MMP2-735 C > T polymorphism rates.In conclusion, MMP9 gene Gln279Arg polymorphism was associated with ET, SP, and PV diseases. Hence, we believe that these gene polymorphisms may play a role in the mechanism of bone marrow fibrosis and may be a factor that increases the risk of thrombosis. Illumination of the molecular basis of the relationship between MMP-thrombosis and MMP-fibrosis provides a better understanding of the pathophysiology of PV and ET diseases and will allow new approaches to diagnosis and treatment. 相似文献
2.
3.
S. Süreyya
zbek Remide Arkun Refik Killi Ayenur Memi Aynur Dadeviren Erkan Sevin 《Journal of clinical ultrasound : JCU》1995,23(4):233-238
Image-directed color Doppler ultrasonography (ICDUS) studies of 86 patients with superficial solid masses yielded significantly lower resistive index (RI) values in acute inflammatory lesions, but no significant difference between the maximum systolic flow velocities (S) of the patient groups with malignant, benign, and acute inflammatory lesions. When analyzed separately, the malignant soft-tissue tumor subgroup was shown to have significantly higher mean RI compared to that of the malignant node subgroup. We conclude that RI may be useful in the differentiation of acute inflammatory masses from other pathological entities. Malignant soft-tissue tumors, especially sarcomas, may have different Doppler features from those of carcinomatous tumors. © 1995 John Wiley & Sons, Inc. 相似文献
4.
Esra Baltacio?lu Ferda Alev Akalin Eda Topalo?lu Erkan Süküro?lu Umit Cobano?lu 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(6):803-808
Ligneous periodontitis (LP) is a rare periodontal disease in which plasminogen deficiency and fibrin deposition both play a part, resulting in characteristic gingival enlargement and periodontal breakdown. Recent data suggest that oxidant/antioxidant changes are significant in the pathology of oral diseases. This study examines the gingival histopathology in 2 cases with LP. To examine the antioxidant (AO) status, the activity of the major AOs glutathione (GSH), catalase (CAT), and glutathione S-transferase (GST) and the malondialdehyde (MDA) levels, a product of lipid peroxidation, were measured and compared with healthy control subjects. The histopathologic examination of the gingiva revealed subepithelial fibrin accumulation and irregular extensive downward proliferation of the epithelium. Biochemical analysis showed that the CAT, GST, and MDA levels were higher in LP patients than in the control subjects, and the GSH level was lower. Our preliminary findings show that in LP, the AO capacity of the gingiva changes or decreases and lipid peroxidation increases, which suggests that oxidative stress is involved in the pathology of the periodontal breakdown observed in this disease. 相似文献
5.
Erkan Yildirim Erkan Kaptanoglu Kanat Ozisik Ethem Beskonakli Ozerk Okutan Mustafa F Sargon Kamer Kilinc Unal Sakinci 《European journal of cardio-thoracic surgery》2004,25(4):523-529
OBJECTIVE: We aimed to demonstrate the time-dependent ultrastructural changes in pneumocyte type II cells following brain injury, and to propose an electron microscopic scoring model for the damage. METHODS: Forty Wistar-Albino female rats weighing 170-200 g were used. The rats were allocated into five groups. The first group was the control and the second was the craniotomy without trauma. The others were trauma groups. Weight-drop method was used for achieving head trauma. Samples were obtained from the right and left pulmonary lobes at 2-, 8-, and 24-h intervals after transcardiac perfusion. An electron microscopic scoring model was used to reveal the changes. RESULTS: There were no ultrastructural pathological findings pointing to lung injury in any rat of the control groups. There was intense intracellular oedema in type II pneumocyte and interstitial oedema in the adjacent tissue in trauma groups. Oedema in mitochondria and dilatation in both smooth endoplasmic reticulum and Golgi apparatus was more evident in the 8- and 24-h trauma groups. The chromatin dispersion was disintegrated in the nucleus in all trauma groups. Scores of all trauma groups were significantly different from the controls (P<0.05). All trauma groups were different from each other at significant levels (P<0.05 for each trauma groups). CONCLUSIONS: The data suggested that ultrastructural damage is obvious at 2 h and deteriorates with time. The electron microscopic scoring model worked well in depicting the traumatic changes, which were supported by lipid peroxidation. Further experiments are needed to determine the exact outcome after brain death model. 相似文献
6.
Ozlem Coskun Serap Ucler Leyla Cavdar Levent E Inan 《Journal of clinical neuroscience》2007,14(4):334-339
Discontinuation of medication is the treatment of choice for patients with chronic daily headache (CDH) who overuse their medications. This treatment may be difficult due to increased headache severity observed in patients immediately after withdrawal. We retrospectively evaluated the efficacy of valproic acid therapy in 66 patients with overuse of CDH medication during withdrawal therapy. Patients were all withdrawn from medications and valproic acid started at 250 mg or 500 mg daily. Forty-two (63.6%) patients had decreased headache severity, including 27.3% objective responses in the first week. At the last visit in the 12th week, 50 patients were headache-free and only one patient had persistent headache. Fifteen patients withdrew from therapy due to side effects and lost to follow-up within this timeframe. Thus, low dose valproic acid appears to be safe and effective in the management of withdrawal therapy. 相似文献
7.
Samet Ozlugedik Muge Ozcan Olca Basturk Orgun Deren Erkan Kaptanoglu G?khan Adanali Adnan Unal 《Skull base》2005,15(4):269-72; discussion 273
Ameloblastic carcinoma (AC) is an aggressive malignant epithelial odontogenic tumor. It may appear de novo or originate from a pre-existing ameloblastoma or odontogenic cyst. To our knowledge, an AC that originates from the anterior skull base has not been reported before in the English literature. We report a case of an AC that originated from the anterior skull base and invaded the dura of the anterior fossa and discuss its clinical course and treatment. 相似文献
8.
Birsen Uçar Ayten Yakut Nurdan Kural Ferit Büyükaşık Erkan Vardareli 《Pediatric nephrology (Berlin, Germany)》1997,11(1):31-35
.We report five patients with Laurence-Moon-Bardet-Biedl syndrome (LMBBS) who had renal involvement. Intravenous pyelography
showed bilateral or unilateral calyceal clubbing and blunting in all patients. In addition, one patient had a parapelvic cyst
in the left kidney and another had bilateral lobulated renal outlines of the fetal type. One patient had a urinary concentrating
defect and two patients showed increased fractional sodium excretion. Estimated tubular phosphate reabsorption values were
in normal limits in all of five patients. No patient had a urine acidification defect, proteinuria, glycosuria, or hyperaminoaciduria.
One patient died from end-stage renal failure. The remaining four patients had normal serum creatinine values and estimated
creatinine clearances. 99mTechnetium-diethylenetriamine pentaacetate renal scanning showed prolonged and delayed concentration and delayed excretion
in three of the four patients who survived. A focal scar was determined on the left kidney of one of four patients by 99mtechnetium-dimercaptosuccinic acid renal scanning. All LMBBS cases with or without renal symptoms should be routinely evaluated
for renal abnormalities. Renal scanning is a valuable method, especially for determining the renal involvement in the early
stage of disease.
Received November 14, 1995; received in revised form and accepted May 23, 1996 相似文献
9.
Cankurtaran Ozlem Olgac Guven Kutlu Cemal Asim 《Indian Journal of Thoracic and Cardiovascular Surgery》2004,20(2):91-92
Indian Journal of Thoracic and Cardiovascular Surgery - 相似文献
10.
Haci Akar Erkan Iriz Fer?at Kolbakir Atilla Sarac Olcay Sagkan 《Annals of thoracic and cardiovascular surgery》2005,11(3):201-203
We describe a case of congenitally corrected transposition of great arteries (CCTGA). Tricuspid valve replacement was performed due to valve dysfunction following bacterial endocarditis. After two weeks' antibiotic therapy haemodynamic stabilisation was obtained and the patient was operated in the third week. On cardiopulmonary bypass with 28 degrees C degree systemic hypothermia, the left atrium was approached transeptally. At exploration, the systemic atrioventricular valve was tricuspid valve and pulmonary atrioventricular valve was in shape of a mitral valve. The posterior leaflet of the tricuspid valve was ruptured and vegetations above it were observed. The valve was excised and a 29 mm St-Jude mechanical heart valve prosthesis implanted using a teflon reinforced separated suture technique. After operation the patient recovered rapidly and following six weeks' antibiotic therapy, the patient was discharged. 相似文献