全文获取类型
收费全文 | 1948篇 |
免费 | 118篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 80篇 |
妇产科学 | 97篇 |
基础医学 | 146篇 |
口腔科学 | 93篇 |
临床医学 | 217篇 |
内科学 | 477篇 |
皮肤病学 | 66篇 |
神经病学 | 176篇 |
特种医学 | 98篇 |
外科学 | 307篇 |
综合类 | 18篇 |
一般理论 | 2篇 |
预防医学 | 78篇 |
眼科学 | 61篇 |
药学 | 69篇 |
中国医学 | 1篇 |
肿瘤学 | 61篇 |
出版年
2024年 | 2篇 |
2023年 | 32篇 |
2022年 | 45篇 |
2021年 | 69篇 |
2020年 | 60篇 |
2019年 | 70篇 |
2018年 | 85篇 |
2017年 | 80篇 |
2016年 | 74篇 |
2015年 | 88篇 |
2014年 | 98篇 |
2013年 | 129篇 |
2012年 | 159篇 |
2011年 | 147篇 |
2010年 | 80篇 |
2009年 | 89篇 |
2008年 | 151篇 |
2007年 | 150篇 |
2006年 | 138篇 |
2005年 | 134篇 |
2004年 | 89篇 |
2003年 | 63篇 |
2002年 | 24篇 |
2001年 | 8篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有2088条查询结果,搜索用时 15 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.
4.
5.
Sevcan A Bakkaloglu Necla Buyan Tohru Funahashi Hatice Pasaoglu Atilla H Elhan Enver Hasanoglu Oguz Soylemezoglu 《Peritoneal dialysis international》2005,25(4):357-361
BACKGROUND: Atherosclerotic vascular diseases are the major cause of mortality in patients with end-stage renal disease (ESRD) treated with chronic peritoneal dialysis (CPD), even in children. Adiponectin (ADPN) is a recently discovered adipocyte-derived plasma protein having anti-atherogenic properties. ADPN levels are elevated in ESRD but it has been reported that ESRD patients with low plasma ADPN levels have a high risk of cardiovascular death. OBJECTIVE: To clarify the atherosclerotic risk and especially the significance of ADPN levels in pediatric patients on CPD. DESIGN: Cross-sectional studyin the pediatric peritoneal dialysis unit of a university hospital. PATIENTS: 18 children, aged 12.6 +/- 5.6 years, being treated with CPD and 20 healthy age- and sex-matched control subjects were enrolled in this study. METHODS: Serum ADPN levels and other risk factors, including blood pressure, blood glucose, serum lipid/lipoprotein fractions, apolipoprotein B, C-reactive protein (CRP), lipoprotein(a), and homocysteine levels, were studied in CPD patients and compared to the controls. RESULTS: Serum ADPN levels were three times higher in the CPD group compared to the control subjects, as was previously reported. Apolipoprotein B and CRP levels were also high in the CPD group. No significant difference was found in other atherosclerotic parameters, including lipoprotein(a) and homocysteine levels. Interestingly, we found a negative correlation between log ADPN and creatinine levels among the CPD patients (r = -0.54, p < 0.05). There was no correlation between log ADPN and duration of CPD. Creatinine and low-density lipoprotein levels could account for 54% of the total variation in ADPN levels. CONCLUSION: Among pediatric CPD patients, serum levels of the anti-atherogenic protein, ADPN, were inversely associated with creatinine. ADPN level might be a novel marker to predict prognosis in pediatric CPD patients. 相似文献
6.
Porcine circovirus type 1 (PCV1) encodes two major ORFs. The cap gene comprises the major structural protein of PCV, the rep gene specifies Rep and Rep', which are both essential for initiating the replication of the viral DNA. Rep corresponds to the full-length protein, whereas Rep' is a truncated splice product that is frame-shifted in its C-terminal sequence. In this study, the cellular localization of PCV1-encoded proteins was investigated by immune fluorescence techniques using antibodies against Rep, Rep' and Cap and by expression of viral proteins fused to green and red fluorescence proteins. Rep and Rep' protein co-localized in the nucleus of infected cells as well as in cells transfected with plasmids expressing Rep and Rep' fused to fluorescence proteins, but no signal was seen in the nucleoli. Rep and Rep' carry three potential nuclear localization signals in their identical N-termini, and the contribution of these motifs to nuclear import was experimentally dissected. In contrast to the rep gene products, the localization of the Cap protein varied. While the Cap protein was restricted to the nucleoli in plasmid-transfected cells and was also localized in the nucleoli at an early stage of PCV1 infection, it was seen in the nucleoplasm and the cytoplasm later in infection, suggesting that a shuttling between distinct cellular compartments occurs. 相似文献
7.
Chronic viral hepatitis is the main cause of chronic liver disease, cirrhosis and hepatocellular carcinoma throughout the world. Hepatitis B virus (HBV) has mutagenic effects on somatic cells. HBV may be showing these mutagenic effects through its viral proteins or through integrating into host DNA. The aim of this study was to determine whether HBV has a genotoxic effect on host DNA or not. Peripheral blood lymphocytes of 31 chronic HBV patients and 20 chronic HBV carriers were cultured in order to make cytogenetic evaluation by observing chromosome breakage and cytological evaluation by the micronucleus (MN) test. Their results were compared with 20 healthy controls. For each individual, 100 metaphase chromosome spreads were analysed. Around 190-1091 binucleated cells were observed and MN were scored for each individual. Our results showed significantly higher frequencies of chromosome breaks in chronic HBV patients and in HBV carriers than in the control group. There was no difference in MN scores among HBV patients, HBV carriers and healthy carriers. Based on our data, we conclude that chronic HBV patients and carriers have chromosomal instability and that HBV carriers are as affected as patients because of their same chromosome breakage levels. 相似文献
8.
Asiye İzem Sandal Hatice Şenlikci Merve Yılmazer Burcu Kartal Bedia Palabıyık Özen Banu Özdaş 《Andrologia》2021,53(5):e14032
The aim of the study was to investigate the efficiency of ram seminal plasma and fetal calf serum on freezing of buck semen. Twenty ejaculates were collected using an electro-ejaculator and split into six groups. While FCS additive was not used in A1, A2 and A3 groups, 10% FCS was added to B1, B2 and B3 groups. These groups were then edited according to whether the buck or ram SP was involved. The design of the groups was done as follows: Group A1 (control 1), group A2 without buck SP, group A3 containing ram SP instead of buck SP. Groups B1 (control 2), B2 and B3 were the FCS added forms of these groups. Progressive sperm motility percentages in Group A1 and Group B2 were found to be higher when compared to the lowest Group B3. There were no significant differences between the groups in neither the levels of reactive oxygen species nor the enzyme and glutathione activities. In conclusion, the lack of statistical difference between the groups suggested that despite the supplements used but only when the buck spermatozoa structure was healthy, the cell could preserve acrosome, DNA and the integrity of membrane. 相似文献
9.
Emrah Caliskan Salih Suha Koparal Volkan Igdir Emre Alp Ozgur Dogan 《Foot and Ankle Surgery》2021,27(4):457-462
BackgroundThe measurement of plantar fascia thickness with ultrasonography can be used for both for diagnosis and as a response-to-treatment parameter in plantar fasciitis. Furthermore, with the recent studies, red cell distribution width may be used as an inflammatory marker. Aim of this study is to investigate the association of red cell distribution width and ultrasonography on diagnosis and monitoring of treatment in patients with plantar fasciitis.MethodsClinically diagnosed 102 patients with plantar fasciitis between the dates January 2016 to July 2018 were analysed. Hemogram, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and plantar fascial ultrasonography were obtained on initial evaluation and in 1 month, 2 months and 3 months of the standard nonoperative treatment; American Orthopaedic Foot & Ankle Hindfoot Score (AOFAS) and Visual Analog Scale (VAS) scores were recorded. Posthoc and multivariate logistic regression analysis were used for statistical analysis on SPSS 21.0.ResultsRed cell distribution width was correlated with plantar fascia thickness by the end of the 1 month (r = 0.26, P = .013). Female sex, BMI over 30 kg/m2, higher red cell distribution width and higher plantar fascia thickness were associated with plantar fasciitis on initial evaluation. Higher red cell distribution width together with higher plantar fascia thickness were also found to be a risk factor for both on initial evaluation and 1 month after treatment in plantar fasciitis.ConclusionThis study shows that association of red cell distribution width and plantar fascia thickness can be not only a diagnostic predictor but also an indicator of treatment response in plantar fasciitis.Level of clinical evidenceLevel IV 相似文献
10.
Zeliha Hayvalı Hüseyin Güler Hatice Öğütcü Nurşen Sarı 《Medicinal chemistry research》2014,23(8):3652-3661
A series of new compounds containing formyl and imine group were synthesized. New formyl-substituted compounds were prepared by the reaction of 1,2-bis(bromomethyl)benzene with benzaldehyde derivatives in the presence of NaOH. New bis-crown ether imine compounds were prepared by the condensation of corresponding aldehydes with 4′-aminobenzo-15-crown-5. Sodium complexes of the bis-crown ethers form crystalline 2:1 (Na+:ligand) stoichiometries were also been synthesized. The prepared compounds were structurally confirmed by analytical and spectral data and evaluated for their antibacterial and antifungal activities. The results show that the antibacterial activity of compounds including o-methoxy group was significantly higher against S. epidermis compared to the other studied antimicrobial group. 相似文献