全文获取类型
收费全文 | 1609篇 |
免费 | 107篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 38篇 |
儿科学 | 57篇 |
妇产科学 | 74篇 |
基础医学 | 127篇 |
口腔科学 | 104篇 |
临床医学 | 186篇 |
内科学 | 391篇 |
皮肤病学 | 59篇 |
神经病学 | 168篇 |
特种医学 | 87篇 |
外科学 | 171篇 |
综合类 | 15篇 |
一般理论 | 1篇 |
预防医学 | 75篇 |
眼科学 | 56篇 |
药学 | 60篇 |
中国医学 | 1篇 |
肿瘤学 | 60篇 |
出版年
2024年 | 1篇 |
2023年 | 26篇 |
2022年 | 34篇 |
2021年 | 60篇 |
2020年 | 50篇 |
2019年 | 62篇 |
2018年 | 62篇 |
2017年 | 69篇 |
2016年 | 67篇 |
2015年 | 77篇 |
2014年 | 85篇 |
2013年 | 111篇 |
2012年 | 135篇 |
2011年 | 124篇 |
2010年 | 61篇 |
2009年 | 69篇 |
2008年 | 133篇 |
2007年 | 114篇 |
2006年 | 95篇 |
2005年 | 108篇 |
2004年 | 77篇 |
2003年 | 55篇 |
2002年 | 22篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 9篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1986年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有1730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.
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
5.
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
6.
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
7.
8.
9.
Cosar E Sahin FK Köken G Toy H Basarali K Büyükbas S 《The Australian & New Zealand journal of obstetrics & gynaecology》2007,47(6):499-503
BACKGROUND: We investigated the effect of alpha-lipoic acid (LA) on reperfusion injury in a rat ovarian torsion-detorsion model. The changes in tissue and plasma levels of malondialdehyde (MDA), end-product of lipid peroxidation, superoxide dismutase (SOD), xanthine oxidase (XO) and nitric oxide (NO), were determined. Ovarian histopathological findings were scored and compared among groups. MATERIALS AND METHODS: Thirty-two female Sprague-Dawley rats were divided into four groups. Sham operation was performed in group I; in group II only ovarian torsion was performed. Group III received intraperitoneal injections of saline, and group IV received LA via intraperitoneal injections (LA group: aqueous solution at 36 mg/kg of body weight per day, saline group: equal volume of saline) 21, nine, and one hour before torsion of the ovary. Rats in the torsion group were killed after 360 degrees clockwise adnexial torsion for three hours, and ovaries were harvested. After three hours of adnexial detorsion, the rats in saline group and LA group were killed and adnexa were surgically removed. RESULTS: Ovarian tissue damage scores were significantly different among groups and were seen to correlate with tissue MDA levels. Ovarian tissue and serum MDA, NO and serum XO levels in the group III were significantly higher than those of the groups I and IV (P<0.05). The serum levels of SOD in the group III were significantly lower than those of the groups I and IV (P<0.05). CONCLUSION: These results suggest that LA pretreatment has beneficial effects in the prevention of ischaemia-reperfusion injury of the ovaries. 相似文献
10.
The aim of this study was to examine the effect of chronotype on addictive eating behavior and BMI in university students. A questionnaire on their sociodemographic characteristics and eating habits, as well as the three-factor eating questionnaire (TFEQ) and the morningness-eveningness questionnaire (MEQ), were given to students at Üsküdar University. Data were analyzed with IBM SPSS 26.0. This study included a total of 850 students, 46.8% of whom were male and 53.2% were female. The mean BMI was 22.94 ± 3.30 kg/m2. As the BMI values of students increased, there was a decrease of 25.6% in the TFEQ scores, regardless of gender (s = −0.256; p < 0.001), and an increase of 10.6% in their chronotype scores, meaning that the students tended to be morning types (s = 0.106; p < 0.01). A significantly negative, very weak correlation was found between the students’ TFEQ and MEQ scores (s = −0.123; p < 0.001). The students’ BMI (p < 0.01) and TFEQ scores (p < 0.001) were affected by their MEQ scores in a statistically significant way. It was found that each 1-point increase in the MEQ score led to a 4.0% increase in the BMI score and a 15.8% decrease in the TFEQ score. It was observed that the morning-type students tended to be obese in terms of their BMI, and these students demonstrated fewer addictive eating behaviors. 相似文献