全文获取类型
收费全文 | 8423篇 |
免费 | 372篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 178篇 |
儿科学 | 271篇 |
妇产科学 | 138篇 |
基础医学 | 913篇 |
口腔科学 | 188篇 |
临床医学 | 559篇 |
内科学 | 2288篇 |
皮肤病学 | 54篇 |
神经病学 | 865篇 |
特种医学 | 394篇 |
外国民族医学 | 4篇 |
外科学 | 1206篇 |
综合类 | 27篇 |
预防医学 | 377篇 |
眼科学 | 91篇 |
药学 | 491篇 |
中国医学 | 16篇 |
肿瘤学 | 768篇 |
出版年
2023年 | 88篇 |
2022年 | 145篇 |
2021年 | 292篇 |
2020年 | 158篇 |
2019年 | 182篇 |
2018年 | 260篇 |
2017年 | 170篇 |
2016年 | 200篇 |
2015年 | 232篇 |
2014年 | 320篇 |
2013年 | 358篇 |
2012年 | 601篇 |
2011年 | 581篇 |
2010年 | 304篇 |
2009年 | 321篇 |
2008年 | 503篇 |
2007年 | 501篇 |
2006年 | 482篇 |
2005年 | 457篇 |
2004年 | 388篇 |
2003年 | 354篇 |
2002年 | 299篇 |
2001年 | 138篇 |
2000年 | 112篇 |
1999年 | 120篇 |
1998年 | 59篇 |
1997年 | 54篇 |
1996年 | 42篇 |
1995年 | 48篇 |
1994年 | 33篇 |
1993年 | 34篇 |
1992年 | 73篇 |
1991年 | 71篇 |
1990年 | 63篇 |
1989年 | 64篇 |
1988年 | 63篇 |
1987年 | 59篇 |
1986年 | 47篇 |
1985年 | 42篇 |
1984年 | 35篇 |
1983年 | 28篇 |
1981年 | 23篇 |
1980年 | 19篇 |
1979年 | 41篇 |
1978年 | 19篇 |
1975年 | 18篇 |
1974年 | 22篇 |
1973年 | 19篇 |
1971年 | 20篇 |
1968年 | 16篇 |
排序方式: 共有8828条查询结果,搜索用时 15 毫秒
1.
Marco Maruzzo Umberto Basso Eugenio Borsatti Laura Evangelista Filippo Alongi Orazio Caffo Francesca Maines Sara Galuppo Rocco De Vivo Fable Zustovich Dario Palleschi Andrea Zivi Teodoro Sava Mariella Sorarù Roberto Iacovelli Maurizio Nicodemo Susanne Baier Lucia Fratino Vittorina Zagonel 《Clinical genitourinary cancer》2019,17(1):e187-e194
Background
Radium 223 was introduced for metastatic castration-resistant prostate cancer based on the results of a randomized controlled trial showing risk reduction for death and skeletal events. Our aim was to evaluate the outcome of patients receiving radium 223 in a real-world setting.Patients and Methods
We conducted a multicenter retrospective analysis in the Triveneto region of Italy.Results
One hundred fifty-eight patients received radium 223 in our region. After a median follow-up of 9.5 months, 75 patients died. The median overall survival (OS) was 14.2 months, and the median progression-free survival (PFS) was 6.2 months. Seventy-one (45%) patients achieved progression as best response. Thirty-seven (23%) patients stopped the treatment early because of progression. Eastern Cooperative Oncology Group performance status was prognostic for OS (18.4 vs. 12.3 vs. 7.5 months; 0 vs. 1, P = .0062; 0 vs. 2, P = .0002), whereas previous prostatectomy or docetaxel exposure were not. A neutrophil to lymphocytes ratio ≥ 3 significantly impacted OS (18.1 vs. 9.7 months; P < .001) and slightly impacted PFS (6.6 vs. 5.6 months; P = .05). Patients with a baseline alkaline phosphatase (ALP) value ≥ 220 U/L had worse OS and PFS (24.1 vs. 10.5 months; 7.2 vs. 5.5 months; P < .001). Patients with changes in ALP value achieved better OS (P = .029) and PFS (P = .002). There was no difference according to the line of therapy (0 vs. ≥ 1; P = .490). The main grade 3/4 toxicities were anemia, asthenia, and thrombocytopenia.Conclusion
This large real-world report confirms comparable OS and PFS data when compared with the pivotal study, as well as the predictive role of ALP and neutrophil to lymphocytes ratio. The definition of the optimal position of radium 223 in the treatment of metastatic castration-resistant prostate cancer has still to be defined. 相似文献2.
Lung cancer is the leading cause of cancer deaths in both men and women in the United States. Treatment depends on the type and stage of lung cancer. For stage I and II cancer, surgery is usually the treatment of choice. Radiation therapy is used in patients who are considered poor risks for surgical resection. Intraoperative brachytherapy is an effective alternative to external irradiation in this group of patients. From 1958 to 1984, 55 patients with non-small-cell lung cancer were explored at Memorial Sloan Kettering Cancer Center and found to have surgical stage I or II tumors, which were considered to be unresectable mainly because of severe obstructive pulmonary disease precluding adequate resection. All these patients were treated with intraoperative brachytherapy at the time of the thoracotomy. Forty-four percent of these patients received in addition external irradiation, mainly to the mediastinum. The overall 5-year survival calculated by the Kaplan-Meier Method was 32%, and the local disease-free survival was 63%. Cox regression multivariant analysis demonstrated that there is a distinct subgroup with a better prognosis based on tumor site and patient's age--ie, patients who were younger than 58 years of age and had right-side lesions. 相似文献
3.
Fernanda Martini Alfredo Corallini Veronica Balatti Silvia Sabbioni Cecilia Pancaldi Mauro Tognon 《Infectious agents and cancer》2007,2(1):13-12
Simian virus 40 (SV40) is a monkey virus that was administered to human populations by contaminated vaccines which were produced
in SV40 naturally infected monkey cells. 相似文献
4.
Testicular biopsy specimens from infertile men (sperm count, less than 10(6)/ml) were evaluated on 1-micron thick sections, and counts of stem cells and differentiated spermatogonia, primary spermatocytes, early and late spermatids, and Sertoli cells were compared to counts in six fertile men. Biopsy specimens were also compared for the appearance of seminiferous tubule wall, blood vessels, and interstitium. Infertile men were grouped according to the following diagnoses: hypospermatogenesis (n = 5), spermatocyte arrest of spermatogenesis (n = 5), and obstruction of the genital tract (n = 7). A low productivity of spermatogenesis in cases of hypospermatogenesis appeared to be due to an exaggerated degeneration of primary spermatocytes and to a yield of abnormal spermatids. A block of meiosis in spermatocyte arrest was associated with a degeneration of primary spermatocytes and with a reduced number of staminal spermatogonia. Abnormal spermiogenesis was observed in cases of obstruction of the genital tract and was associated with an increase in stem cell spermatogonia. A thickening of seminiferous tubule and blood vessel walls could be responsible for the limited functional capacity of Sertoli cells, causing altered spermiogenesis in cases of excretory azoospermia. A severe primitive failure of Sertoli cells in secretory oligoazoospermia could account for a deranged maturation and degeneration of premeiotic and postmeiotic germ cells. 相似文献
5.
Luigi La Vecchia Paolo Vincenzi Luca Favero Manuela Martini Andrea Rubboli Filippo Ottani Leonardo Varotto Alessandro Fontanelli 《Italian heart journal》2004,5(10):749-754
BACKGROUND: Recent studies evaluated the technique of direct coronary stenting as compared to stenting-after-predilation in selected anatomic and clinical settings. However, the impact of direct stenting in routine interventional practice remains poorly elucidated. METHODS: From April 1999 to March 2001, all percutaneous coronary interventions performed at our Center were prospectively analyzed to determine the frequency of direct stenting, the success rate and the variables associated with its utilization. RESULTS: 1151 lesions were treated in 835 procedures. Stenting was attempted in 835/1151 lesions (72.5%), 309 (37%) with direct stenting and 526 (63%) with stenting-after-predilation. Direct stenting was successful in 300/309 (97%) and stenting-after-predilation in 515/526 (98%). The success rate of direct stenting was significantly lower in small vessels (< or = 2.75 mm) (89.2 vs 98.5%, p = 0.005). Patients treated with direct stenting were younger (63 +/- 11 vs 65 +/- 11 years, p = 0.024). Direct stenting was preferentially used in saphenous vein grafts and at the ostium of the left anterior descending coronary artery, while it was avoided in bifurcation lesions and with increasing calcium burden. Operators with a caseload > 140 interventions per year were significantly more likely to perform direct stenting than less experienced operators (p = 0.017). In direct stenting, the total contrast medium and the fluoroscopy and procedural times were all significantly (p < 0.0001) lower than those observed in case of stenting-after-predilation. CONCLUSIONS: Direct coronary stenting is currently performed in about one third of the overall caseload. Variables pertaining to the operator's experience, lesion morphology and length, vessel size, and the clinical presentation are all important factors determining the selection of candidates suitable for direct stenting. 相似文献
6.
Noel R. Fajardo Filippo Cremonini Dr Nicholas J. Talley 《American Journal of Cancer》2006,5(5):319-330
In patients with cancer, constipation is a common complication. However, unlike in the general population, the impact of the symptoms of constipation on the quality of life in cancer patients is often greater. More importantly, in patients who are in the more advanced stages of the disease, constipation may also be suggestive of disease progression. Constipation as a symptom in this population is of significant importance as it may lead to life-threatening complications, i.e. bowel perforation due to fecal impaction. Therefore, in this regard, this problem deserves particular attention, as early recognition and management of complications may prevent further physical deterioration. This review aims to provide an overview of the management of constipation in patients with cancer. A symptom-based criteria definition for chronic constipation and prevalence of the problem in cancer patients provides a brief introduction. For the initial assessment and evaluation of constipation in cancer patients, an algorithm is described. The different possible etiologies of constipation in cancer patients are also discussed. Regarding therapeutic management, guidelines and recommendations for the use of different types of laxatives, stool softeners, suppositories and rectal enemas, prokinetic agents, antidepressant medications, and miscellaneous agents are succinctly discussed. Management of fecal impaction and opioid-induced bowel dysfunction are also described. Lastly, a brief overview of the management of acute colonic pseudo-obstruction and surgical or endoscopic options for large bowel obstruction are described. 相似文献
7.
Sylvie Di Filippo Bertrand Semiond Ricardo Roriz Francois Sassolas Marie José Raboisson André Bozio 《The Journal of heart and lung transplantation》2003,22(8):876-882
BACKGROUND: Coronary vasculopathy is the main cause of cardiac graft failure. Because yearly coronary angiography is invasive in children, a non-invasive method for detecting graft vasculopathy is needed. The aim of this study was to test dobutamine-stress echocardiography in a pediatric population to determine its feasibility, safety and reliability in the detection of graft coronary artery disease. METHODS: Eighteen patients, aged 2 days to 16.8 years at transplantation (mean 8.4 years), underwent 44 dobutamine-stress echocardiography (DSE) exams, at a follow-up of 1.1 to 11.8 years (mean 5.1 years). Selective coronary angiography was performed for comparison. Echocardiographic recordings were obtained in 4 standard views of the left ventricle and measurements carried out within the frames of a 16-segment model. Segmental scores of contractility were obtained for each segment and a total segmental contractility index was calculated at each stage. RESULTS: All patients reached the maximum dose stage. Maximum heart rate was 57% to 90% of predicted maximum. Maximum systolic blood pressure reached 190 mmHg. Segmental scores were normal in 37 and abnormal in 7 cases. Echographic results were concordant with angiography in 82% and discordant in 18% of the cases (4 negative DSEs with minor angiographic lesions, 2 positive DSEs with normal angiography), but there was no significant angiographic lesion with normal DSE. CONCLUSIONS: DSE is a safe and highly feasible non-invasive technique in transplanted children. A normal DSE study successfully predicts the absence of significant coronary artery disease in the post-transplant population. 相似文献
8.
Vincenzo La Milia Salvatore Di Filippo Monica Crepaldi Simeone Andrulli Lucia Del Vecchio Pietro Scaravilli Giovambattista Virga Francesco Locatelli 《Nephrology, dialysis, transplantation》2004,19(7):1849-1855
BACKGROUND: Sodium removal (NaR) may have a major impact on the survival of peritoneal dialysis patients. The dialysate/plasma sodium concentration ratio (D/P(Na)) is an indirect index of transcellular water transport by aquaporin channels, and thus of ultrafiltration. Sodium concentration can be assessed by means of flame photometry (F), and direct (D-ISE) or indirect ion-selective electrodes (I-ISE), but these methods have different properties. I-ISE is being used increasingly in clinical laboratories. The aim of this study was to evaluate NaR and D/P(Na) using the three different measurement methods. METHODS: We performed peritoneal equilibration tests (PETs) in 44 peritoneal dialysis patients and calculated the NaR. We also calculated D/P(Na) during the test; plasma and dialysate sodium concentrations were measured by F, D-ISE and I-ISE. RESULTS: NaR was lower (P<0.001) with D-ISE (69+/-29 mmol) than with F (81+/-29 mmol) or I-ISE (79+/-28 mmol). D/P(Na) was also lower at baseline (0.92+/-0.02 vs 0.95+/-0.02 and 0.95+/-0.02; P<0.001), after 60 min (0.87+/-0.03 vs 0.90+/-0.03 and 0.90+/-0.03; P<0.001) and at the end of PET (0.88+/-0.04 vs 0.92+/-0.04 and 0.92+/-0.04; P<0.001) when measured by D-ISE in comparison with F and I-ISE, respectively. CONCLUSIONS: NaR and D/P(Na) were lower when measured by the D-ISE method compared with the F and I-ISE methods. NaR and D/P(Na) were similar when measured by F or I-ISE. I-ISE can be used reliably in the evaluation of NaR and D/P(Na) in everyday clinical practice of peritoneal dialysis. 相似文献
9.
10.
G Biagi O Livi A Lucacchini C Martini V Scartoni 《Journal of pharmaceutical sciences》1992,81(6):543-545
Certain 1,2,3-triazole derivatives were prepared and tested for their ability to displace [3H]diazepam that was bound to bovine brain membrane protein. All the tested compounds are essentially lacking in this ability, except for B.1, which inhibited binding of [3H]diazepam in 50% of the trials at 2.5 microM. The structure of B.1, with a 1,2,3-triazole ring with acidic properties, supports the hypothesis proposed for binding to the benzodiazepine receptor site. Comparison of B.1 with 1,2,3-triazole derivatives bearing a bicyclic substituent in position 1 of the heterocyclic ring suggests that a high steric hindrance increases the affinity of a compound for the benzodiazepine receptor. 相似文献