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   590篇
  免费   16篇
  国内免费   5篇
耳鼻咽喉   8篇
儿科学   9篇
妇产科学   17篇
基础医学   87篇
口腔科学   2篇
临床医学   32篇
内科学   163篇
皮肤病学   10篇
神经病学   49篇
特种医学   14篇
外科学   32篇
综合类   3篇
预防医学   62篇
眼科学   12篇
药学   75篇
肿瘤学   36篇
  2023年   5篇
  2022年   39篇
  2021年   71篇
  2020年   17篇
  2019年   24篇
  2018年   29篇
  2017年   19篇
  2016年   29篇
  2015年   19篇
  2014年   22篇
  2013年   37篇
  2012年   39篇
  2011年   42篇
  2010年   23篇
  2009年   12篇
  2008年   30篇
  2007年   32篇
  2006年   25篇
  2005年   26篇
  2004年   28篇
  2003年   20篇
  2002年   11篇
  2001年   2篇
  1997年   1篇
  1996年   1篇
  1992年   1篇
  1989年   2篇
  1986年   1篇
  1980年   1篇
  1976年   1篇
  1973年   1篇
  1966年   1篇
排序方式: 共有611条查询结果,搜索用时 15 毫秒
1.
2.
(1) Background: The aim of this study was to assess the concentrations of selected elements in female patients with cancer of the reproductive organs, taking into account the stage of treatment. (2) Methods: The study sample consisted of 51 patients with advanced endometrial cancer and ovarian cancer, undergoing chemotherapy. The median age of the studied patients with endometrial cancer was 66.0 years (IQR: from 60.75 to 70.25), and with ovarian cancer―60.0 years (IQR: from 49.0 to 64.0). Each of the qualified women, after consent to participate in the study, had her blood drawn several times (before surgery, the first course of chemotherapy, the third course of chemotherapy, and the sixth course of chemotherapy) in order to determine serum levels of macro- and micronutrients (Na, Mg, Ca, Zn, P, Cu, Fe, Cd, Ni, and Sr). (3) Results: In the study group of patients with cancer of the reproductive tract, the concentrations of iron (<0.001), magnesium (0.038), sodium (0.014), and nickel (0.037) varied significantly over the course of the study. The analysis showed that the interaction between the stage of chemotherapy and the type of cancer had an effect on the concentrations of magnesium and cadmium (p < 0.05). (4) Conclusions: In the studied group of patients with ovarian and endometrial cancer, the applied chemotherapy significantly changed the concentrations of Fe, Na, and Ni, regardless of the type of tumor. Changes in Mg and Cd concentrations resulted from the interaction between the stage of chemotherapy and the type of cancer. The results of serum concentrations of selected elements in women with cancer of the reproductive organs may help understand the physiological changes resulting from the applied chemotherapy.  相似文献   
3.
Introduction: The risk of obesity in children with Down syndrome is high. Undoubtedly, proper nutrition plays an important role in the prevention of excess body weight and is associated with a reduction of metabolic complications. The aim of the study was to assess the problem of disturbances in the nutritional status and eating habits of children with DS. Methods: A total of 39 patients were included in the study. The nutritional status was assessed by anthropometric tests and Dual X-ray Absorptiometry. Eating habits were assessed using the Child Eating Behavior Questionnaire and the Food Frequency Questionnaire. Blood samples were taken to determine the oxidative stress and lipid parameters. Results: Obesity was recognized in 15% of subjects and 23% were overweight. Children that were overweight were characterized by higher levels of triglycerides, atherogenic index of plasma, and apoA2 and apoE levels. Fat mass, fat mass/height2 index, and visceral fat mass correlated with thiobarbituric acid reactive substances and advanced oxidative protein product level. The analysis of the Child Eating Behavior Questionnaire showed that children struggling with being overweight were more interested in food compared to those with normal body weight. A positive correlation was identified between waist circumference and food interest categories. Insufficient consumption of dairy products, vegetables, whole grain products, as well as fruits, seeds, nuts, and fatty fish was noted. Patients were less likely to consume products that are a good source of mono- and polyunsaturated fatty acids. Conclusions: In children with Down syndrome and obesity, disturbances in lipid and oxidative stress parameters are observed. Abnormal eating habits in all children with Down syndrome regardless of their nutritional status were noted. Proper nutritional education, nutritional control, and management of metabolic problems are essential in this group of patients.  相似文献   
4.
The process of platinum recovery from used car catalysts is highly desirable for both economic and environmental reasons. From the many available methods of processing used car catalysts, the article conducted both numerical and experimental studies using a device based on the collector metal method with lead as a modified medium through a magnetohydrodynamic pump for washing platinum from the channels of the ceramic catalyst carrier. It was assumed that lead alloys with the addition of lithium increase the extraction of platinum from thin catalytic layers and accelerate the platinum dissolution reaction in the Pb-Li alloy, which is the result of a greater affinity of lithium for platinum compared to lead. This assumption was verified by numerical simulations as well as laboratory tests. Tests were carried out for the secondary supply voltage range between 40 and 60 V and the catalyst flushing time between 240 and 480 s. Graphical results of the research were discussed.  相似文献   
5.
Lake Szmaragdowe and Czarnog?owy Reservoir are both characterized by atypical origin as both were formed when quarries were flooded. The geological substrates of the two basins are unique, and they are both highly valued as recreational and tourist destinations. These two basins are among the most interesting in northwestern Poland. Studies of their thermal regimes confirmed that water mass mixing in Lake Szmaragdowe is bradymictic. The waters in the Czarnog?owy Reservoir mix entirely to a depth of 20 m, and this layer is also characterized by bradymixia. Deeper waters do not mix. This indicates that mixing in this basin is of the meromictic type.  相似文献   
6.
Modification of ultrasmall gold nanoparticles (AuNPs) with the lipoic acid derivative of folic acid was found to enhance their accumulation in the cancer cell, as compared to AuNPs without addressing units. The application of lipoic acid enabled the control of the gold nanoparticle functionalities leading to enhanced solubility and allowing for attachment of both the folic acid and the cytotoxic drug, doxorubicin. More robust attachment of doxorubicin to the nanoparticle through the amide bond resulted in toxicity comparable with that of the drug alone, opening a new perspective for designing more potent, but less toxic nanopharmaceuticals. The increased uptake was accompanied by pronounced nuclear accumulation and observable cytotoxicity. Doxorubicin binding via covalent amide bonds enhanced stability of the whole drug vehicle and provided much better control over doxorubicin release in the cell environment, as compared to physical adsorption or pH sensitive bonding commonly used for anthracycline carriers. Confocal microscopy revealed that the bond was stable in the cytoplasm for 22 h. The ability to slow down the rate of drug release may be crucial for the application in sustained anticancer drug delivery. Biological analyses performed using MTT assay and confocal microscopy confirmed that the ultrasmall AuNPs with the lipoic acid derivative of folic acid exhibit relatively low cytotoxicity, however when loaded with a chemotherapeutic, they cause a significant reduction in the cell viability.

Modification of ultrasmall gold nanoparticles (AuNPs) with the lipoic acid derivative of folic acid was found to enhance their accumulation in the cancer cell, as compared to AuNPs without addressing units.  相似文献   
7.

Objective

Since over forty years structuralized interviews for clinical and epidemiological research in child and adolescent psychiatry are being developed that should increase validity and reliability of diagnoses according to classification systems (DSM and ICD). The aim of the study is to assess the validity of the Polish version of MINI-KID (Mini International Neuropsychiatric Interview for Children and Adolescents) in comparison to clinical diagnosis made by a specialist in the field of child and adolescent psychiatry.

Materials and methods

There were 140 patients included in the study (93 boys, 66.4%, mean age 11.8 ± 3.0 and 47 girls 33.5%, mean age 14.0 ± 2.9). All the patients were diagnosed by the specialist in the field of child and adolescent psychiatry according to ICD-10 criteria and by the independent interviewer with the Polish version of MINI-KID (version 2.0, 2001).

Results

There was higher agreement between clinical diagnoses and diagnoses based on MINI-KID interview with respect to eating disorders and externalizing disorders (κ 0.43–0.56) and lower in internalizing disorders (κ 0.13–0.45). In the clinical interview, there was smaller number of diagnostic categories (maximum 3 diagnoses per one patient) in comparison to MINI-KID (maximum 10 diagnoses per one patient), and the smaller percentage of patients with one diagnosis (65,7%) in comparison to MINI-KID interview (72%).

Conclusion

Our study has shown satisfactory validity parameters of MINI-KID questionnaire, promoting its use for clinical and epidemiological settings.

Implications and contribution

The Mini International Neuropsychiatry Interview for Children and Adolescent (MINI-KID) is the first structuralized diagnostic interview for assessing mental status in children and adolescents, which has been translated into Polish language. Our validation study demonstrated satisfactory psychometric properties of the questionnaire, enabling its use in clinical practice and in research projects.  相似文献   
8.

Background

Chronic kidney disease (CKD) is becoming a serious health problem; the number of people with impaired renal function is rapidly rising, especially in industrialized countries. A major complication of CKD is cardiovascular disease. Accelerated atherosclerosis has been observed in early stages of renal dysfunction. The purpose of this study was to examine the relationship between the degree of renal insufficiency and both the prevalence and intensity of coronary artery disease (assessed on the basis of number of vessels with stenosis).

Methods

446 individuals with both serum creatinine >120 μmol/l (men) or >96 μmol/l (women) and acute coronary syndrome were included in the study. All patients included in this analysis underwent urgent coronarography. Data concerning glomerular filtration rate (GFR), number of vessels with stenosis, hypertension, lipid disorders, creatinine concentration, C-reactive protein, glucose and lipid profile were analyzed.

Results

This study confirmed that moderate to severe renal impairment is associated with accelerated atherosclerosis. Moreover, patients with GFR values below 60 ml/min/1.73 m2 are predisposed to accelerated, multivessel cardiovascular disease.

Conclusions

GFR seems to be an independent risk factor for multivessel cardiovascular disease. Due to the fact that patients with renal dysfunction are at high risk of cardiovascular events, they should obtain optimal treatment resulting not only in kidney protection but also in the elimination of cardiovascular risk factors.  相似文献   
9.
The main aim of the present study was the synthesis of an oligonucleotide-based material with high chemical stability, repeatability and specificity to complementary oligonucleotides. The oligonucleotides were attached to a silica gel surface modified with amino acids during one-step synthesis. The amount of the oligonucleotides immobilized on the support surface had an impact on adsorption effectiveness, due to steric interference. The adsorption capacity corresponds to 4.7 μg of complementary oligonucleotide per 1 mg of material, which reflects 50% of immobilized oligonucleotides. The presented results contain comprehensive studies on hybridization and release of fully complementary, partially complementary, non-complementary and antisense oligonucleotides from the newly synthesized adsorbent. The salt concentration and time period were the most influential parameters in the case of adsorption, while high temperature and low salt content were indispensable for effective desorption. Selectivity studies revealed that the adsorption percentage increases with the decreasing number of base mismatches. Consequently, the desorption of low complementarity oligonucleotides was always greater in comparison with the fully complementary sequence. Furthermore, it was shown that oligonucleotide-based materials may be successfully used for the extraction of antisense oligonucleotides and their metabolites from serum samples with recoveries ranging between 65 and 73%.

The main aim of the present study was the synthesis of an oligonucleotide-based material with high chemical stability, repeatability and specificity to complementary oligonucleotides.  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