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What evidence is there for the existence of individual genes with antagonistic pleiotropic effects? 总被引:6,自引:0,他引:6
Leroi AM Bartke A De Benedictis G Franceschi C Gartner A Gonos ES Gonos E Fedei ME Feder ME Kivisild T Lee S Kartaf-Ozer N Kartal-Ozer N Schumacher M Sikora E Slagboom E Tatar M Yashin AI Vijg J Zwaan B 《Mechanisms of ageing and development》2005,126(3):421-429
Classical evolutionary theory predicts the existence of genes with antagonistic effects on longevity and various components of early-life fitness. Quantitative genetic studies have provided convincing evidence that such genes exist. However, antagonistic pleiotropic effects have rarely been attributed to individual loci. We examine several classes of longevity-assurance genes: those involved in regulation of the gonad; the insulin-like growth factor pathway; free-radical scavenging; heat shock proteins and apoptosis. We find initial evidence that antagonistic pleiotropic effects are pervasive in each of these classes of genes and in various model systems--although most studies lack explicit studies of fitness components. This is particularly true of human studies. Very little is known about the early-life fitness effects of longevity loci. Given the possible medical importance of such effects we urge their future study. 相似文献
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Kellis E 《European journal of applied physiology》2003,89(3-4):271-280
The examination of the moment exerted by the hamstrings during maximum isokinetic knee extensor tests is useful when comparing
isokinetic strength and muscle activity patterns between children and adults. The purpose of this study was to examine the
effect of antagonist moment of the hamstrings on the isokinetic moment of the knee extensors in pubertal children and to determine
whether this effect is altered following a fatigue task. Eighteen healthy pubertal males [age 14.3 (0.5) years] performed
34 maximal isokinetic concentric efforts of the knee extensors at 60°·s−1. The average moment of force and electromyographic (aEMG) signal of vastus medialis (VM), vastus lateralis (VL) and biceps
femoris (BF) at 11–30°, 31–50°, 51–70° and 71–90° of knee flexion were calculated for each repetition. The hamstrings antagonist
moment was determined before and after the fatigue task by fitting the aEMG–moment relationship at different levels of muscle
effort using second-degree polynomials. The percentage contribution of the antagonist moment to the resultant joint moment
ranged from 7.1 % to 60.4 % throughout the range of motion, with the highest percentage observed close to full knee extension
(11–30°). The antagonist effect was significantly greater during concentric tests of the knee extensors compared to the corresponding
eccentric tests (p<0.05). Following the fatigue test, there was an overall decline of the resultant joint moment, but no changes in the predicted
hamstrings moment were observed. These results indicate that when testing maximal knee extensor isokinetic strength in pubertal
boys, activity of the hamstrings implies a reduction of the net extensor moment as compared to the isolated capacity of the
knee extensors. However, this antagonist effect is not altered following the performance of an isokinetic fatigue knee extension
task.
Electronic Publication 相似文献
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Evangelia Katsouri Emmanuella Magriplis Antonis Zampelas Eleftherios H. Drosinos George-John Nychas 《Nutrients》2021,13(2)
Gravieras are ‘gruyere’ type hard cheeses with a variety of different products and the second highest consumption in Greece. In this study, we present a dietary intake assessment and a nutritional characterization of pre-packed graviera products sold in the Greek market using Nutri-Score Front of Pack Label (FoPL). The nutrient contents of 92 pre-packed graviera products were combined with daily individual consumption data extracted from the Hellenic National Nutrition Health Survey (n = 93), attempting to evaluate the contribution of graviera’s consumption to the Greek diet. The analysis of nutrients’ intake as a Reference Intake (RI) percentage ranked saturated fat first on the nutrients’ intake list, with RI percentage ranging from 36.1 to 109.2% for the 95th percentile of consumption. The respective % RI for energy, total fat, carbohydrates, sugars, proteins and salt ranged from 12.7–20.7%, 21.6–50.4%, 0–3.1%, 0–6.1%, 37–57.1% and 6.3–42%. Nutri-Score classified 1% of the products to C—light orange class, 62% to D—orange and 37% to E—dark orange, while no products were classified to A—dark green or B—green classes. The comparison between the Nutri-Score classification and the nutrients’ intake assessment, also separately conducted within the classes, showed a higher salt intake after the consumption of products classified as D—orange and E—dark orange. 相似文献
6.
Erna Busch MD Miguel Rodriguez-Bigas MD Eleftherios Mamounas MD Maurice Barcos MD Dr. Nicholas J. Petrelli MD 《Annals of surgical oncology》1994,1(3):222-228
Background: The gastrointestinal tract is the most common site of extranodal involvement in non-Hodgkin's lymphoma (NHL). Primary colorectal NHL comprises 13–18% of all gastrointestinal NHL but is not commonly reported as a separate entity.
Methods: This was a retrospective review of the medical records of 19 patients over a 16-year period to evaluate the clinical features and behavior of colorectal NHL.
Results: A pediatric group of seven male patients presented at an early stage with acute symptomatology. The primary tumor was located in the ileocecum in all cases and intussusception was common. An adult group of 12 patients presented at a later stage with chronic symptomatology. Staging study results were positive by bone marrow biopsy in four of 16 patients (25%), by lymphangiography in six of 11 patients (54.5%), and by gallium scan in eight of 10 patients (80%). Seven patients relapsed a median of 8 months after treatment. Three other patients died during treatment, one died of other causes, and one died without receiving treatment. The remaining seven patients are alive from 41 to 231 months without evidence of disease. Five of these patients are in the pediatric group, where the median survival was >72 months. The overall median survival was 45 months.
Conclusion: Colorectal NHL is a disease that affects both the pediatric and adult population. Although pediatric patients have an excellent prognosis with anticipated long-term survival after treatment, long-term survival can be expected in 50% of adult patients. In both groups of patients, multimodality therapy with surgery, chemotherapy, and radiation is the treatment of choice.Presented at the 46th Annual Cancer Symposium of The Society of Surgical Oncology, Los Angeles, California, March 18–21, 1993. 相似文献
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Human kallikrein 6 (hK6): a new potential serum biomarker for diagnosis and prognosis of ovarian carcinoma. 总被引:12,自引:0,他引:12
Eleftherios P Diamandis Andreas Scorilas Stefano Fracchioli Marleen Van Gramberen Henk De Bruijn Alfthan Henrik Antoninus Soosaipillai Linda Grass George M Yousef Ulf-Hakan Stenman Marco Massobrio Ate G J Van Der Zee Ignace Vergote Dionyssios Katsaros 《Journal of clinical oncology》2003,21(6):1035-1043
PURPOSE: The discovery of new ovarian cancer biomarkers that are suitable for early disease diagnosis and prognosis may ultimately lead to improved patient management and outcomes. PATIENTS AND METHODS: We measured, by immunoassay, human kallikrein 6 (hK6) concentration in serum of 97 apparently healthy women, 141 women with benign abdominal diseases, and 146 women with histologically proven primary ovarian carcinoma. We then calculated the diagnostic sensitivity and specificity of this test and examined the association of serum hK6 concentration with various clinicopathologic variables and patient survival. RESULTS: Serum hK6 concentration between normal and benign disease patients was not different (mean, 2.9 and 3.1 micro g/L, respectively). However, hK6 in presurgical serum of ovarian cancer patients was highly elevated (mean, 6.8 micro g/L; P <.001). Serum hK6 decreased after surgery (to a mean of 3.9 micro g/L) in 68% of patients. The diagnostic sensitivity of serum hK6 at 90% and 95% specificity is 52% and 47%, respectively, in the whole patient population. For early stage disease (stage I or II), sensitivity is approximately 21% to 26%. When combined with CA-125, at 90% specificity, sensitivity increases to 72% (for all patients) and to 42% in stage I or II disease. Serum hK6 concentration correlates moderately with CA-125 and is higher in patients with late-stage, higher-grade disease and in patients with serous histotype. Preoperative serum hK6 concentration is a powerful predictor of disease-free and overall survival in both univariate and multivariate analyses. CONCLUSIONS: Serum hK6 concentration seems to be a new biomarker for ovarian carcinoma and may have value for disease diagnosis and prognosis. 相似文献
9.
Eleftherios P Mamounas Ann Brown Stewart Anderson Roy Smith Thomas Julian Barbara Miller Harry D Bear Christopher B Caldwell Alonzo P Walker Wendy M Mikkelson Jay S Stauffer Andre Robidoux Heather Theoret Atilla Soran Atilla Sovan Bernard Fisher D Lawrence Wickerham Norman Wolmark 《Journal of clinical oncology》2005,23(12):2694-2702
PURPOSE: Experience with sentinel node biopsy (SNB) after neoadjuvant chemotherapy is limited. We examined the feasibility and accuracy of this procedure within a randomized trial in patients treated with neoadjuvant chemotherapy. PATIENTS AND METHODS: During the conduct of National Surgical Adjuvant Breast and Bowel Project trial B-27, several participating surgeons attempted SNB before the required axillary dissection in 428 patients. All underwent lymphatic mapping and an attempt to identify and remove a sentinel node. Lymphatic mapping was performed with radioactive colloid (14.7%), with lymphazurin blue dye alone (29.9%), or with both (54.7%). RESULTS: Success rate for the identification and removal of a sentinel node was 84.8%. Success rate increased significantly with the use of radioisotope (87.6% to 88.9%) versus with the use of lymphazurin alone (78.1%, P = .03). There were no significant differences in success rate according to clinical tumor size, clinical nodal status, age, or calendar year of random assignment. Of 343 patients who had SNB and axillary dissection, the sentinel nodes were positive in 125 patients and were the only positive nodes in 70 patients (56.0%). Of the 218 patients with negative sentinel nodes, nonsentinel nodes were positive in 15 (false-negative rate, 10.7%; 15 of 140 patients). There were no significant differences in false-negative rate according to clinical patient and tumor characteristics, method of lymphatic mapping, or breast tumor response to chemotherapy. CONCLUSION: These results are comparable to those obtained from multicenter studies evaluating SNB before systemic therapy and suggest that the sentinel node concept is applicable following neoadjuvant chemotherapy. 相似文献