全文获取类型
收费全文 | 2706篇 |
免费 | 121篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 204篇 |
妇产科学 | 109篇 |
基础医学 | 201篇 |
口腔科学 | 95篇 |
临床医学 | 187篇 |
内科学 | 506篇 |
皮肤病学 | 39篇 |
神经病学 | 160篇 |
特种医学 | 142篇 |
外科学 | 665篇 |
综合类 | 33篇 |
一般理论 | 2篇 |
预防医学 | 84篇 |
眼科学 | 119篇 |
药学 | 157篇 |
中国医学 | 6篇 |
肿瘤学 | 109篇 |
出版年
2023年 | 11篇 |
2022年 | 8篇 |
2021年 | 32篇 |
2020年 | 31篇 |
2019年 | 36篇 |
2018年 | 45篇 |
2017年 | 44篇 |
2016年 | 69篇 |
2015年 | 67篇 |
2014年 | 68篇 |
2013年 | 162篇 |
2012年 | 179篇 |
2011年 | 179篇 |
2010年 | 99篇 |
2009年 | 89篇 |
2008年 | 168篇 |
2007年 | 197篇 |
2006年 | 203篇 |
2005年 | 197篇 |
2004年 | 154篇 |
2003年 | 153篇 |
2002年 | 102篇 |
2001年 | 78篇 |
2000年 | 71篇 |
1999年 | 38篇 |
1996年 | 7篇 |
1992年 | 20篇 |
1991年 | 13篇 |
1990年 | 15篇 |
1989年 | 17篇 |
1988年 | 29篇 |
1987年 | 17篇 |
1986年 | 19篇 |
1985年 | 18篇 |
1984年 | 10篇 |
1983年 | 14篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 6篇 |
1979年 | 13篇 |
1978年 | 14篇 |
1974年 | 12篇 |
1973年 | 14篇 |
1972年 | 10篇 |
1971年 | 10篇 |
1969年 | 18篇 |
1968年 | 9篇 |
1967年 | 7篇 |
1966年 | 6篇 |
1965年 | 6篇 |
排序方式: 共有2841条查询结果,搜索用时 31 毫秒
1.
Ozkan Kanat Hulya Ertas Burcu Caner 《World journal of gastrointestinal oncology》2020,12(10):1080-1090
The treatment of metastatic colorectal cancer (mCRC) harboring BRAF V600 mutations is challenging. These tumors are often refractory to standard treatment. Therefore, the patients may exhibit rapid clinical deterioration, depriving them of the chance to receive salvage therapy. In newly diagnosed patients with good performance status, the administration of an intensive chemotherapy regimen like FOLFOXIRI (5-fluorouracil, leucovorin, oxaliplatin, and irinotecan) along with the antiangiogenic agent bevacizumab can modify this aggressive behavior of the disease and improve patient clinical outcomes. The recently published results of the BEACON (Binimetinib, Encorafenib, and Cetuximab Combined to Treat BRAF-Mutant Colorectal Cancer) study demonstrated that a combination therapy consisting of BRAF, epidermal growth factor receptor, and mitogen-activated protein kinase kinase inhibitors could be a useful second-or third-line alternative. This review summarizes the current treatment strategies for BRAF-mutant mCRC. 相似文献
2.
Kirchner Sophie K. Ozkan Selen Musil Richard Spellmann Ilja Kannayian Nirmal Falkai Peter Rossner Moritz Papiol Sergi 《European archives of psychiatry and clinical neuroscience》2020,270(4):425-431
European Archives of Psychiatry and Clinical Neuroscience - Cognitive deficits are increasingly recognized as a core dimension rather than a consequence of schizophrenia (SCZ). The previous... 相似文献
3.
4.
5.
6.
Sibel Ozkan Gurdal Ayse Nilufer Ozaydin Erkin Aribal Beyza Ozcinar Neslihan Cabiolu Cennet Sahin Vahit Ozmen 《Diagnostic and interventional radiology (Ankara, Turkey)》2021,27(2):157
PURPOSEWe aimed to show the effects of long-term screening on clinical, pathologic, and survival outcomes in patients with screen-detected breast cancer and compare these findings with breast cancer patients registered in the National Breast Cancer Registry Data (NBCRD).METHODSWomen aged 40–69 years, living in Bahcesehir county, Istanbul, Turkey, were screened every 2 years using bilateral mammography. The Bahcesehir National Breast Cancer Registry Data (BMSP) data were collected during a 10-year screening period (five rounds of screening). BMSP data were compared with the NBCRD regarding age, cancer stage, types of surgery, tumor size, lymph node status, molecular subtypes, and survival rates.RESULTSDuring the 10-year screening period, 8758 women were screened with 22621 mammograms. Breast cancer was detected in 130 patients; 51 (39.2%) were aged 40–49 years. The comparison of breast cancer patients in the two programs revealed that BMSP patients had earlier stages, higher breast-conserving surgery rates, smaller tumor size, more frequent negative axillary nodal status, lower histologic grade, and higher ductal carcinoma in situ rates than NBCRD patients (p = 0.001, for all).CONCLUSIONThese results indicate the feasibility of successful population-based screening in middle-income countries.Breast cancer is the most frequent cancer and cause of cancer-related deaths among Turkish women, as well as globally (1–5). Although the incidence of breast cancer increases every year, mortality rates are decreasing in developed countries because of nationwide screening programs and modern treatment options (5, 6). An invited mammography screening program for women aged between 40 and 69 years revealed a 60% reduction in cancer-related 10-year mortality in a landmark study (7). A systematic review of Myers et al. (8) showed that breast cancer screening reduced mortality by 20% in average-risk women of all age groups. However, this review did not evaluate the differences between annual and biannual mammographic screening.In 2004, the Cancer Control Department of Turkey recommended biannual mammographic screening for women aged 50–69 years, based on European Guidelines. The population of Turkey is relatively young, and almost half of all breast cancer patients in Turkey are younger than 50 years. According to and National Breast Cancer Registry Data (NBCRD) reports, the starting age for mammography screening was set as 40 years. The Bahcesehir Mammographic Screening Program (BMSP) was the first organized population-based 10-year (2009–2019) mammography screening program in Turkey, a middle-income country.Turkish Federation of Breast Diseases Societies started a voluntary data registry program that was provided by breast surgeons working in secondary or tertiary hospitals. This program aimed to collect detailed information of breast cancer patients and to pool comprehensive country-specific breast cancer data. This registry, namely the NBCRD, was the first specified database on breast cancer in the country and was started in 2005, before the BMSP (9). Data from 36 centers were collected for 10 years. However, the cancer registry is a standard database containing general information as defined by the International Agency for Research on Cancer standards.The aim of this study was to show the feasibility of a population-based breast cancer screening program in an emerging, middle-income country, Turkey. The objective of our study was to evaluate the effectiveness of a population-based breast cancer screening program by comparing it with NBCRD data. 相似文献
7.
8.
O. Esim A. Savaser C.K. Ozkan Z. Bayrak C. Tas Y. Ozkan 《Saudi Pharmaceutical Journal》2018,26(1):53-63
A two factor three level factorial design was used to investigate the effects of carbopol and cationic hydrophilic polymers which have a common use in buccal drug formulations. Statistical models with interaction terms were derived to evaluate influence of carbopol (X1) and chitosan (X2) on tablet disintegration (Y1) and dissolution (Y2), mechanical properties (Y3), swelling (Y4). Tablet disintegration studies were carried out using two different pH environments within buccal region pH limits and also two different commonly used dissolution methods for buccal tablets were also investigated to compare the effect of polymer type on dissolution. Polymer type and ratio affect the characteristics of the buccal tablets due to their different physicochemical behavior at buccal pH. Also significant variances between dissolution profiles for buccal tablets, using either USP Paddle or flow through cell methods were found. These results indicate that both polymer type and ratio as well as combination of them effects the drug behavior in different ways. 相似文献
9.
Basak Isildar Serbay Ozkan Mahmut Oncul Zafer Baslar Semih Kaleli Mustafa Tasyurekli Meral Koyuturk 《Acta histochemica》2019,121(3):361-367
The main purpose of this study is to establish an effective cryopreservation protocol for the umbilical cord tissue as a source of mesenchymal stem cells (MSCs). In this context, it was aimed to use a cryoprotectant that could be an alternative to dimethyl sulfoxide (DMSO) which is commonly used despite the toxic side effects. Therefore, two different cryopreservation solutions were prepared using 10% DMSO and 10% 1,2 propanediol (PrOH). The fresh tissue group that was not performed cryopreservation was used as the control group. Following the cryopreservation step, MSCs were isolated from all groups and compared with each other to assess the efficiency of the cryopreservation solutions. The comparison was performed in terms of followings: morphology, immunophenotypes, growth kinetics, differentiation, and ultrastructural features. Based on the results, there were no significant morphological and immunophenotypic differences between the MSCs isolated from cryopreserved tissue groups and the MSCs isolated from the fresh tissue group. According to the growth kinetic analysis, the cells isolated from the PrOH group had a lower proliferation rate than the cells isolated from the fresh tissue. However, there was no significant difference between the cryopreserved groups in this respect. Osteogenic and adipogenic differentiation was observed in all groups. Upon comparison of the cryopreserved groups, PrOH group was discovered to hold a minor superiority in terms of these modes of differentiation. These results suggest that PrOH, which is considered as a cryoprotectant with low toxicity, could be used as a preferred cryoprotectant instead of DMSO concerning the process of cryopreservation of the umbilical cord. 相似文献
10.
β‐adrenergic Receptor Blocker ICI 118,551 Selectively Increases Intermediate‐Conductance Calcium‐Activated Potassium Channel (IKCa)‐Mediated Relaxations in Rat Main Mesenteric Artery 下载免费PDF全文
Endothelial IKCa and/or SKCa channels play an important role in the control of vascular tone by participating in endothelium‐dependent relaxation. Whether β‐AR antagonists, mainly used in hypertension, affect endothelial KCa channel function is unknown. In this study, we examined the effect of the β2‐AR antagonist and inverse agonist ICI 118,551 on the IKCa/SKCa channel activity by assessing functional relaxation responses to several agonists that stimulate these channels. Mesenteric arterial rings isolated from male Sprague Dawley mounted to organ baths. Acetylcholine elicited IKCa‐ and SKCa‐mediated relaxations that were abolished by TRAM‐34 and apamin, respectively. ICI 118,551, which did not dilate the arteries per se, increased the IKCa‐mediated relaxations, whereas SKCa‐mediated relaxations remained unaltered. Same potentiating effect was also detected on the IKCa‐mediated relaxations to carbachol and A23187, but not to NS309. Neither acetylcholine‐induced nitric oxide‐mediated relaxations nor SNP relaxations changed with ICI 118,551. The PKA inhibitor KT‐5720, the selective β2‐AR agonist salbutamol, the selective β2‐AR antagonist butoxamine, the non‐selective β‐AR antagonist propranolol, and the inverse agonists carvedilol or nadolol failed to affect the IKCa‐mediated relaxations. ICI 118,551‐induced increase was not reversed by salbutamol or propranolol as well. Besides, low potassium‐induced relaxations in endothelium‐removed arteries remained the same in the presence of ICI 118,551. These data demonstrate a previously unrecognized action of ICI 118,551, the ability to potentiate endothelial IKCa channel‐mediated vasodilation, through a mechanism independent of β2‐AR antagonistic or inverse agonistic action. Instead, the enhancement of acetylcholine relaxation seems likely to occur by a mechanism secondary to endothelial calcium increase. 相似文献