全文获取类型
收费全文 | 2590篇 |
免费 | 135篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 35篇 |
儿科学 | 138篇 |
妇产科学 | 21篇 |
基础医学 | 308篇 |
口腔科学 | 72篇 |
临床医学 | 225篇 |
内科学 | 633篇 |
皮肤病学 | 6篇 |
神经病学 | 320篇 |
特种医学 | 110篇 |
外科学 | 391篇 |
综合类 | 11篇 |
预防医学 | 131篇 |
眼科学 | 62篇 |
药学 | 114篇 |
中国医学 | 2篇 |
肿瘤学 | 166篇 |
出版年
2023年 | 14篇 |
2022年 | 32篇 |
2021年 | 72篇 |
2020年 | 45篇 |
2019年 | 77篇 |
2018年 | 89篇 |
2017年 | 59篇 |
2016年 | 76篇 |
2015年 | 82篇 |
2014年 | 103篇 |
2013年 | 143篇 |
2012年 | 167篇 |
2011年 | 124篇 |
2010年 | 83篇 |
2009年 | 83篇 |
2008年 | 134篇 |
2007年 | 117篇 |
2006年 | 140篇 |
2005年 | 125篇 |
2004年 | 127篇 |
2003年 | 123篇 |
2002年 | 108篇 |
2001年 | 52篇 |
2000年 | 68篇 |
1999年 | 52篇 |
1998年 | 29篇 |
1997年 | 20篇 |
1996年 | 13篇 |
1995年 | 27篇 |
1994年 | 16篇 |
1993年 | 16篇 |
1992年 | 36篇 |
1991年 | 35篇 |
1990年 | 26篇 |
1989年 | 16篇 |
1988年 | 31篇 |
1987年 | 45篇 |
1986年 | 16篇 |
1985年 | 14篇 |
1984年 | 13篇 |
1983年 | 16篇 |
1982年 | 13篇 |
1981年 | 5篇 |
1979年 | 9篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1971年 | 4篇 |
1968年 | 4篇 |
1967年 | 6篇 |
1965年 | 4篇 |
排序方式: 共有2745条查询结果,搜索用时 15 毫秒
1.
2.
Maria Ricci Agostino Chiaravalloti Alessandro Martorana Giacomo Koch Vincenzo De lucia Gaetano Barbagallo Orazio Schillaci 《Annals of nuclear medicine》2020,34(4):254-262
The aim of our study was to investigate the impact of the epsilon phenotype in brain glucose consumption in a population with Alzheimer’s disease. Statistical Parametric Mapping (SPM8) was used to investigate differences in brain glucose consumption (as detectable by means of 18F FDG-PET/CT) in the population examined. A total of 129 patients (72 females and 57 males) with a diagnosis of probable AD according to the NINCDS-ADRDA criteria underwent the PET/CT examination. The mean (SD) age of the patients was 70 (± 7) years; the mean Mini-Mental State Examination was 19(± 5.6). 59 expressed epsilon 4 phenotype (E4) and 70 expressed the epsilon 3 phenotype (E3). Cerebral spinal fluid amyloid, tau, and t-tau have been measured resulting equal to 367.4 (± 149.1), 584.7 (± 312.1), and 79.2(± 45.9) pg/ml, respectively. Patients with confirmed amyloid and Tau changes were classified as AD. Patients with amyloid changes but negative Tau, considered as high risk of AD, were classified as IAD. Age, sex, MMSE, scholarship, and CSF parameters were used as a covariate in the SPM analyses. We did not find significant differences in age, gender, and MMSE and CSF parameters among groups. In the analysis of the AD group as compared to AD-E3, AD-E4 subjects show a significant reduction of brain glucose consumption in inferior frontal gyrus bilaterally (BA 45, BA 47). In the analysis of the IAD group as compared to IAD-E3, IAD-E4 subjects show a significant reduction of brain glucose consumption in right in medial, middle, and superior frontal gyrus (BA10, BA11), and in left medial and middle frontal gyrus (BA10, BA11). The differences between IAD-E3 and AD-E3 and between IAD-E4 and AD-E4 (and vice versa analysis) resulted not significant. APO-e4 is related to a major involvement of the frontal cortex confirming its role of risk factor in AD, while APO-3 seems not related to a specific pattern, supporting the hypothesis of neutral/protective role in AD. 相似文献
3.
Giorgio Gandaglia Guillaume Ploussard Massimo Valerio Agostino Mattei Cristian Fiori Nicola Fossati Armando Stabile Jean-Baptiste Beauval Bernard Malavaud Mathieu Roumiguié Daniele Robesti Paolo Dell’Oglio Marco Moschini Stefania Zamboni Arnas Rakauskas Francesco De Cobelli Francesco Porpiglia Francesco Montorsi Alberto Briganti 《European urology》2019,75(3):506-514
Background
Available models for predicting lymph node invasion (LNI) in prostate cancer (PCa) patients undergoing radical prostatectomy (RP) might not be applicable to men diagnosed via magnetic resonance imaging (MRI)-targeted biopsies.Objective
To assess the accuracy of available tools to predict LNI and to develop a novel model for men diagnosed via MRI-targeted biopsies.Design, setting, and participants
A total of 497 patients diagnosed via MRI-targeted biopsies and treated with RP and extended pelvic lymph node dissection (ePLND) at five institutions were retrospectively identified.Outcome measurements and statistical analyses
Three available models predicting LNI were evaluated using the area under the receiver operating characteristic curve (AUC), calibration plots, and decision curve analyses. A nomogram predicting LNI was developed and internally validated.Results and limitations
Overall, 62 patients (12.5%) had LNI. The median number of nodes removed was 15. The AUC for the Briganti 2012, Briganti 2017, and MSKCC nomograms was 82%, 82%, and 81%, respectively, and their calibration characteristics were suboptimal. A model including PSA, clinical stage and maximum diameter of the index lesion on multiparametric MRI (mpMRI), grade group on targeted biopsy, and the presence of clinically significant PCa on concomitant systematic biopsy had an AUC of 86% and represented the basis for a coefficient-based nomogram. This tool exhibited a higher AUC and higher net benefit compared to available models developed using standard biopsies. Using a cutoff of 7%, 244 ePLNDs (57%) would be spared and a lower number of LNIs would be missed compared to available nomograms (1.6% vs 4.6% vs 4.5% vs 4.2% for the new nomogram vs Briganti 2012 vs Briganti 2017 vs MSKCC).Conclusions
Available models predicting LNI are characterized by suboptimal accuracy and clinical net benefit for patients diagnosed via MRI-targeted biopsies. A novel nomogram including mpMRI and MRI-targeted biopsy data should be used to identify candidates for ePLND in this setting.Patient summary
We developed the first nomogram to predict lymph node invasion (LNI) in prostate cancer patients diagnosed via magnetic resonance imaging-targeted biopsy undergoing radical prostatectomy. Adoption of this model to identify candidates for extended pelvic lymph node dissection could avoid up to 60% of these procedures at the cost of missing only 1.6% patients with LNI. 相似文献4.
Najat C Daw Wayne L Furman Clinton F Stewart Lisa C Iacono Mark Krailo Mark L Bernstein Janet E Dancey Rose Anne Speights Susan M Blaney James M Croop Gregory H Reaman Peter C Adamson 《Journal of clinical oncology》2005,23(25):6172-6180
PURPOSE: Epidermal growth factor receptor is expressed in pediatric malignant solid tumors. We conducted a phase I trial of gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, in children with refractory solid tumors. PATIENTS AND METHODS: Gefitinib (150, 300, 400, or 500 mg/m2) was administered orally to cohorts of three to six patients once daily continuously until disease progression or significant toxicity. Pharmacokinetic studies were performed during course one (day 1 through 28). RESULTS: Of the 25 enrolled patients, 19 (median age, 15 years) were fully evaluable for toxicity and received 54 courses. Dose-limiting toxicity was rash in two patients treated with 500 mg/m2 and elevated ALT and AST in one patient treated with 400 mg/m2. The maximum-tolerated dose was 400 mg/m2/d. The most frequent non-dose-limiting toxicities were grade 1 or 2 dry skin, anemia, diarrhea, nausea, and vomiting. One patient with Ewing's sarcoma had a partial response. Disease stabilized for 8 to > or = 60 weeks in two patients with Wilms' tumor and two with brainstem glioma (one exophytic). At 400 mg/m2, the median peak gefitinib plasma concentration was 2.2 microg/mL (range, 1.2 to 3.6 microg/mL) and occurred at a median of 2.3 hours (range, 2.0 to 8.3 hours) after drug administration. The median apparent clearance and median half-life were 14.8 L/h/m2 (range, 3.8 to 24.8 L/h/m2) and 11.7 hours (range, 5.6 to 22.8 hours), respectively. Gefitinib systemic exposures were comparable with those associated with antitumor activity in adults. CONCLUSION: Oral gefitinib is well tolerated in children. Development of the drug in combination with cytotoxic chemotherapy will be pursued. 相似文献
5.
V Caverni M Rastrelli R Aufieri R Agostino 《The journal of maternal-fetal & neonatal medicine》2004,15(2):126-128
OBJECTIVE: To assess whether dedicated ambulances would improve the efficiency of the neonatal emergency transport service (NETS). METHODS: The efficiency of NETS was investigated in the Lazio region, Italy, by comparing data collected during the first 6 months of 1997 (from 1 January to 30 June), with those collected during the same months of 2000, using NETS availability and time investment as indicators. The data yielded by the study were reported as number and percentage, and were analyzed by SPSS 10.1 software; chi2 analysis with Pearson's correction was used to assess the statistical significance of the differences between the two groups; p < 0.05 was considered statistically significant. RESULTS: Our investigation showed a reduced availability of the service in 2000, compared to 1997 (90.4% vs. 95%; p < 0.03). We also noted that in 2000 all dedicated ambulances remained off duty for 26 days, owing to engine failure. The response time and the total transfer time where much longer in 2000 than in 1997 (response time > 30 min in 8% vs. 3%, p < 0.008; total transfer time > 120 min in 37% vs. 30%, p < 0.04). CONCLUSIONS: The reduced efficiency in 2000 was mainly due to the lack of ambulances used to replace the dedicated ambulances. However, the type of ambulance that may provide the best replacement for NETS remains an unsolved question. 相似文献
6.
G Zamboni G Franzin F Bonetti A Scarpa M Chilosi R Colombari F Menestrina M Pea C Iacono G Serio 《The American journal of surgical pathology》1990,14(8):703-713
We report the clinicopathologic, immunohistochemical, and ultrastructural features of three small-cell neuroendocrine carcinomas of the ampullary region of the duodenum. All patients were men; their ages were 51, 62, and 66 years. The therapy consisted of pancreatoduodenectomy. All patients died of the disease; median survival was 10 months from the diagnosis. The histological appearance was identical to pulmonary and extrapulmonary small-cell carcinoma. The neuroendocrine differentiation was demonstrated ultrastructurally by the presence of dense-core granules, and by the positive immunoreaction for neuron-specific enolase and Leu-7 in each case. One case expressed a focal positivity for chromogranin A (PHE-5) and argyrophilic granules. The same case showed the presence of neurofilaments on frozen material. Neurofilament proteins could not be demonstrated in any case in paraffin sections. Neoplastic cells exhibited cytoplasmic immunostaining for cytokeratins (CAM 5.2) in all cases. In one case, a large number of neoplastic cells (60-70%) exhibited nuclear Ki-67 positivity. We postulate that the disease's histogenesis was from epithelial stem cell expressing both epithelial and neuroendocrine characteristics. The clinical behavior of small-cell neuroendocrine carcinomas of the ampullary region appears to be extremely aggressive, with early metastases and fatal outcome. 相似文献
7.
G Iacono A Carroccio F Cavataio G Montalto M Soresi V Balsamo 《Journal of pediatric gastroenterology and nutrition》1992,14(2):177-181
We report a study of realimentation techniques in 9 unweaned infants with multiple food hypersensitivity. The patients had presented severe symptoms of cow's milk allergy and successive attempts using milk containing soy protein and/or a semielemental formula in their alimentation did not improve their clinical condition, due to the onset of hypersensitivity to these allergens as well. After a short period of parenteral alimentation the infants were refed per os with ass' milk (250 ml/kg/day) + medium chain triglycerides (40 ml/L milk). This food was well tolerated by all patients. No negative clinical reactions were recorded and during hospitalisation average weight increase was 39.8 g/day. The follow-up of the patients showed that ass' milk was tolerated without any problems up to an age ranging from 15 to 20 months, when cow's milk was reintroduced in some patients. 相似文献
8.
Novel heteroplasmic mtDNA mutation in a family with heterogeneous clinical presentations. 总被引:1,自引:0,他引:1
P Corona E Lamantea M Greco F Carrara A Agostino D Guidetti M T Dotti C Mariotti M Zeviani 《Annals of neurology》2002,51(1):118-122
The protean manifestations of a novel maternally inherited point mutation of the mitochondrial genome are reported. The proband showed isolated, spastic paraparesis. A brother, who had suffered from a multisystem progressive disorder, ultimately died of cardiomyopathy. Another brother is healthy. The proband's mother showed truncal ataxia, dysarthria, severe hearing loss, mental regression, ptosis, ophthalmoparesis, distal cyclones, and diabetes mellitus. A muscle biopsy performed in the proband failed to show the morphological abnormalities typical of mitochondrial disorders; the activities of respiratory chain complexes were normal. However, complex I and IV activities were low in the muscle homogenate of the affected mother and brother. Sequence analysis of mtDNA showed a heteroplasmic mutation of the tRNA(Ile) gene (G4284A). The mutation load was approximately 55%, 80%, and 90% in the muscle mtDNA of the proband, his mother, and his affected brother, respectively. Mutation was undetected in the healthy brother, as well as in 100 control samples. Several cybrid clones containing homoplasmic mutant mtDNA from the proband showed significant reductions of complex IV activity and maximum oxygen consumption rate, compared with homoplasmic wild-type clones derived from the same subject. 相似文献
9.
Intra-amniotic inflammation in human gastroschisis: possible aetiology of postnatal bowel dysfunction 总被引:1,自引:0,他引:1
John J. Morrison Lecturer/Senior Registrar Nigel Klein Consultant † Lyn S. Chitty Consultant Gabriella Kocjan Consultant Denise Walshe Laboratory Assistant † Mark Goulding Laboratory Assistant † Michael P. Geary Research Fellow Agostino Pierro Consultant § Charles H. Rodeck Professor 《BJOG : an international journal of obstetrics and gynaecology》1998,105(11):1200-1204
10.