全文获取类型
收费全文 | 629篇 |
免费 | 43篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 13篇 |
妇产科学 | 3篇 |
基础医学 | 91篇 |
口腔科学 | 12篇 |
临床医学 | 85篇 |
内科学 | 153篇 |
皮肤病学 | 1篇 |
神经病学 | 40篇 |
特种医学 | 64篇 |
外科学 | 64篇 |
综合类 | 9篇 |
预防医学 | 39篇 |
眼科学 | 7篇 |
药学 | 69篇 |
肿瘤学 | 33篇 |
出版年
2023年 | 7篇 |
2022年 | 6篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 18篇 |
2018年 | 15篇 |
2017年 | 19篇 |
2016年 | 9篇 |
2015年 | 12篇 |
2014年 | 15篇 |
2013年 | 33篇 |
2012年 | 20篇 |
2011年 | 37篇 |
2010年 | 24篇 |
2009年 | 13篇 |
2008年 | 23篇 |
2007年 | 27篇 |
2006年 | 28篇 |
2005年 | 18篇 |
2004年 | 17篇 |
2003年 | 15篇 |
2002年 | 7篇 |
2001年 | 9篇 |
2000年 | 16篇 |
1999年 | 27篇 |
1998年 | 23篇 |
1997年 | 16篇 |
1996年 | 26篇 |
1995年 | 12篇 |
1994年 | 15篇 |
1993年 | 20篇 |
1992年 | 12篇 |
1991年 | 13篇 |
1990年 | 11篇 |
1989年 | 18篇 |
1988年 | 17篇 |
1987年 | 13篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 9篇 |
1981年 | 5篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1975年 | 5篇 |
1971年 | 4篇 |
1970年 | 3篇 |
1969年 | 3篇 |
排序方式: 共有690条查询结果,搜索用时 15 毫秒
51.
K. D. Hove C. Brøns K. Færch S. S. Lund J. S. Petersen A. E. Karlsen P. Rossing J. F. Rehfeld A. Vaag 《Diabetologia》2013,56(1):22-30
Aims/hypothesis
Recent studies suggest that proton pump inhibitor treatment may increase insulin secretion and improve glucose metabolism in type 2 diabetes. In a randomised double-blind prospective placebo-controlled 2 × 2 factorial study, we examined the effect of esomeprazole on insulin secretion, HbA1c and cardiovascular risk factors in type 2 diabetes.Methods
Forty-one patients with type 2 diabetes using dietary control or oral glucose-lowering treatment were randomised to receive add-on esomeprazole 40 mg (n?=?20) or placebo (n?=?21) for 12 weeks. Randomisation was carried out prior to inclusion on the basis of a computer-generated random-number list. The allocation sequence was concealed in sealed envelopes from the researcher enrolling and assessing participants. The study was undertaken at Steno Diabetes Center, Gentofte, Denmark. The primary outcome was change in AUC for insulin levels during a meal test. Secondary outcomes were the levels of HbA1c and biochemical markers of cardiovascular risk, including lipids, coagulation factors, inflammation markers, markers of endothelial function and 24 h ambulatory BP measurements.Results
Forty-one participants were analysed. In the esomeprazole-treated group the AUC for insulin did not change (before vs after treatment: 28,049?±?17,659 vs 27,270?±?32,004 pmol/l × min (p?=?0.838). In the placebo group AUC for insulin decreased from 27,392?±?14,348 pmol/l × min to 22,938?±?11,936 pmol/l × min (p?=?0.002). Esomeprazole treatment (n?=?20) caused a ninefold increase in the AUC for gastrin. HbA1c increased from 7.0?±?0.6% (53?±?5 mmol/mol) to 7.3?±?0.8% (56?±?6 mmol/mol) in the esomeprazole-treated group and from 7.0?±?0.6% (53?±?5 mmol/mol) to 7.4?±?0.8% (57?±?6 mmol/mol) in the placebo group (n?=?21) (p for difference in change >0.05). Except for BP, there were no differences between the groups in the markers of cardiovascular risk (p?>?0.05). Monitoring of 24 h ambulatory BP showed a significant decrease in daytime systolic BP, daytime diastolic BP and 24 h diastolic BP in the placebo group (p?<?0.05). No change in BP was seen in the patients treated with esomeprazole.Conclusions/interpretation
Treatment with esomeprazole over 12 weeks did not improve insulin secretion, glycaemic control or cardiovascular disease biomarkers in patients with type 2 diabetes.Trial registration
ClinicalTrials.gov NCT00699426Funding
The study was funded by Novo Nordisk A/S and Christian Hansen A/S. 相似文献52.
可逆性胆硷酯酶抑制剂二甲氨基甲酸-5-二氢吲哚酯的合成 总被引:1,自引:0,他引:1
为了深入研究催醒宁类化合物的结构与抑酶活性的关系,设计合成了-系列1-,3-或5-位不同取代的二氢吲哚类衍生物(中间体和终产物共24个新化合物)。中间体1,3-二甲基-5-烷氧基-2-二氢吲哚酮(A)的C3烷化。采用相转移催化方法进行;反应中还分离到三个副产物(Ⅶ~Ⅸ)。初筛结果表明:这些化合物大多有较强的抑酶活性;1,3-或5-位取代基的改变均明显影响其活性。 相似文献
53.
S Hovland M Arbyn A K Lie W Ryd B Borge E J Berle H Skomedal T M Kadima L Kyembwa E M Billay D Mukwege R B Chirimwami T M Mvula P J Snijders C J L M Meijer F Karlsen 《British journal of cancer》2010,102(6):957-965
Background:
Given the high burden of cervical cancer in low-income settings, there is a need for a convenient and affordable method for detecting and treating pre-cancerous lesions.Methods:
Samples for comparing the accuracy of cytology, virology and histology were collected. Identification of HPV E6/E7 mRNA was performed using PreTect HPV-Proofer. HPV DNA detection was performed by GP5+/6+ PCR, followed by reverse line blot (RLB) for typing.Results:
A total of 343 women, aged 25–60 years, attending gynaecological polyclinics in DR Congo were included for sample enrolment. The test positivity rate was conventional and liquid-based cytology (LBC) at cutoff ASCUS+ of 6.9 and 6.6%, respectively; PreTect HPV-Proofer of 7.3% and consensus DNA PCR for 14 HR types of 18.5%. Sixteen cases of CIN2+ lesions were identified. Of these, conventional cytology identified 66.7% with a specificity of 96.2%, LBC identified 73.3% with a specificity of 96.9%, all at cutoff ASCUS+. HR-HPV DNA detected all CIN2+ cases with a specificity of 85.9%, whereas PreTect HPV-Proofer gave a sensitivity of 81.3% and a specificity of 96.6%.Conclusion:
Both HPV detection assays showed a higher sensitivity for CIN2+ than did cytological methods. Detecting E6/E7 mRNA from only a subset of HR HPVs, as is the case with PreTect HPV-Proofer, resulted in a similar specificity to cytology and a significantly higher specificity than consensus HR HPV DNA (P<0.0001). 相似文献54.
Braffman BH; Coleman BG; Ramchandani P; Arger PH; Nodine CF; Dinsmore BJ; Louie A; Betsch SE 《Radiology》1994,190(3):797
55.
In order to study the pattern of B cell involvement in acute nonlymphocytic leukemia (ANLL), multiple B lymphoid cell lines were established by Epstein-Barr virus transformation of peripheral blood mononuclear cells from two patients with the disease who were heterozygous for the X chromosome-linked glucose-6-phosphate dehydrogenase (G6PD). In one patient, the progenitor cells involved by the leukemia exhibited multipotent differentiative expression, whereas in the other patient the cells showed differentiative expression restricted to the granulocytic pathway. In the patient whose abnormal clone showed multipotent expression, the ratio of B-A G6PD in B lymphoid cell lines was skewed in the direction of type B (the enzyme characteristic of the leukemia clone) and significantly different from the 1:1 ratio expected. It is, therefore, likely that the neoplastic event occurred in a stem cell common to the lymphoid series as well as to the myeloid series. In contrast, evidence for B cell involvement was not detected in the patient whose ANLL progenitor cells exhibited restricted differentiative expression. These findings underscore the heterogeneity of ANLL. Clinically and morphologically similar malignancies in these two patients originated in progenitors with different patterns of stem cell differentiative expression. This difference may reflect differences in cause and pathogenesis. 相似文献
56.
Mueller PR; Silverman SG; Tung G; Brink JA; Cardenosa G; Saini S; Forman BH; Hahn PF 《Radiology》1989,173(1):278-279
A new tray has been designed for use during procedures involving needles and other sharp objects. The tray includes a foam adhesive pad, marked into 10 sections, into which the sharp objects can be placed point first. After the procedure, the objects can be safely withdrawn by their handles and then discarded. The tray has been used in more than 250 procedures. 相似文献
57.
Clinical problems in non-fluctuating patients with Parkinson's disease: a community-based study. 总被引:2,自引:0,他引:2
OBJECTIVE: To investigate the frequency of nonfluctuators in a community-based prevalence study of Parkinson's disease (PD) and to describe disability, non-motor problems, and health-related quality of life in patients with PD with and without motor fluctuations, and compare the findings to those of two control groups. METHODS: The study involved 245 patients with PD who were participating in a prevalence study and two control groups (100 healthy elderly individuals and 100 patients with diabetes mellitus [DM]). Data were obtained through neurologic examination and a semistructured interview, and by the use of several questionnaires. RESULTS: In this group of unselected patients with PD, 78% did not experience motor fluctuations. Mean duration of treatment with levodopa was 6.3 years. Patients with motor fluctuations had a lower age at onset of disease, longer duration of disease, and a higher daily levodopa dose than patients without fluctuations. Among the non-fluctuating patients, we found more dementia and a higher age at prevalence day. Disability (assessed by the Unified Parkinson's Disease Rating Scale subscales for activities of daily living and motor function and the Hoehn and Yahr stage) was similar in fluctuators and nonfluctuators. Depression, sleep disturbances, and fatigue were equally frequent in both patient groups. The occurrence of these difficulties was clearly more frequent among non-fluctuating patients with PD than among the control subjects. CONCLUSION: Most patients in the general population who have PD do not experience dose-dependent motor fluctuations. Severity of motor disability and neuropsychiatric manifestations are as important in non-fluctuators as in fluctuators. Patients without motor fluctuations have more depression, sleep disturbances, fatigue, and a poorer health-related quality of life than patients with DM and healthy elderly individuals. This also underlines the importance of developing better management and treatment strategies for this group of patients with PD. 相似文献
58.
S J Karlsen T Bull-Njaa A Krokstad 《Journal of endourology / Endourological Society》2001,15(8):821-826
BACKGROUND: There is concern about applying intraureteral lithotripsy in pregnant patients, as the sound created by the equipment may damage fetal hearing. MATERIALS AND METHODS: The sound intensities produced by electrokinetic, pneumomechanic, holmium laser, ultrasound, and electrohydraulic intraluminal lithotripters were measured in an in vitro model. RESULTS: The purely mechanical modalities (electrokinetic and pneumomechanic) generated lower peak pressures than the other devices. Theoretical calculations were performed based on the fact that in vivo, the sound path and the fetal middle ear cavities are filled with fluid. Calculated pressure levels that give displacement amplitudes of the tympanic membrane, the ossicles, and the basilar membrane comparable to hearing loss risk criteria for airborne impulsive noise are greater than measured for all of the lithotripters. The fluid-filled middle ear thus seems to give the fetus protection against sound. The fluid also improves the symmetry of the cochlea structure, reducing the influence of direct bone transmission. CONCLUSIONS: The peak pressure of the sound emitted by lithotripsy in the ureter during pregnancy is unlikely to be harmful to fetal hearing. Other risk factors, such as the form of the sound waves and the pulse duration were not evaluated. The theoretical assessments are simplified, and one should be careful about drawing conclusions from theoretical considerations and calculations alone. 相似文献
59.
The objective of this study was to evaluate the impact of pre-analytical factors on the short and long term stability of ascorbic acid (AA), the main form of vitamin C in whole blood and plasma. The effects of various anticoagulants, acidification, storage temperature and time were tested. A recently developed fast and sensitive HPLC method was used to measure AA levels. AA baseline values observed in heparin plasma were significantly higher than values observed in EDTA, citrate and Stabilyte plasma, as well as in serum. pH and temperature were identified as additional critical pre-analytical factors during the short, medium and long term handling and storage. Thus, assessment of reliable and accurate AA status in biological samples demonstrates to be highly dependent on whether the initial conditions during sample handling are controlled. In conclusion, heparin tubes should be used for blood sample collection. As AA is rapidly degraded, sample collection should be followed by immediate centrifugation and plasma acidification. To avoid further degradation during sample handling, samples should be stored at -70 degrees C without delay and analyzed within 80 days. 相似文献
60.
Detection of fetal red cells in fetomaternal hemorrhage using a fetal hemoglobin monoclonal antibody by flow cytometry 总被引:4,自引:0,他引:4
BACKGROUND: The laboratory determination of the level of fetal cells in maternal circulation remains an important support in the obstetrical management of women with suspected uterine trauma and in the proper dose administration of anti-D for prevention of Rh hemolytic disease of the newborn. Limitations in the sensitivity and precision of the widely used manual Kleihauer-Betke test have prompted an increased utilization of flow cytometric methods for fetal cell detection in maternal blood samples. STUDY DESIGN AND METHODS: Murine monoclonal antibodies directed against fetal hemoglobin (HbF) were developed, conjugated to fluorescein isothiocyanate, and used in a multiparametric flow cytometric assay developed for the quantitation of fetal red cells. A rapid intracellular staining method using brief glutaraldehyde fixation and Triton X-100 permeabilization prior to monoclonal antibody incubation was developed, along with optimization of the flow cytometric analysis protocol for the analysis of 50,000 cells. The performance of the assay was assessed for linearity and precision and correlated with the Kleihauer-Betke acid elution method. RESULTS: The anti-HbF flow cytometric method showed good correlation with the Kleihauer-Betke method (r2 = 0.86) and superior precision with a CV < 15 percent for blood samples with > 0.1 percent fetal cells. Analysis of 150 blood samples from nonpregnant adults, including individuals with elevated HbF due to hemoglobinopathies and hereditary persistence of HbF, gave a mean value of 0.02 percent fetal cells, and all results were less than 0.1 percent. CONCLUSIONS: The anti-HbF flow cytometric method for detection of fetal cells offers a simple, reliable, and more precise alternative to the Kleihauer-Betke manual technique for the assessment of fetomaternal hemorrhage. The method has additional potential applications for the study of HbF levels or frequency of adult red cells with low levels of HbF (F cells) in individuals with hemoglobinopathies. 相似文献