全文获取类型
收费全文 | 11614篇 |
免费 | 653篇 |
国内免费 | 105篇 |
专业分类
耳鼻咽喉 | 108篇 |
儿科学 | 226篇 |
妇产科学 | 327篇 |
基础医学 | 1491篇 |
口腔科学 | 464篇 |
临床医学 | 932篇 |
内科学 | 2877篇 |
皮肤病学 | 139篇 |
神经病学 | 970篇 |
特种医学 | 473篇 |
外国民族医学 | 1篇 |
外科学 | 1930篇 |
综合类 | 34篇 |
预防医学 | 506篇 |
眼科学 | 125篇 |
药学 | 713篇 |
中国医学 | 31篇 |
肿瘤学 | 1025篇 |
出版年
2024年 | 8篇 |
2023年 | 85篇 |
2022年 | 231篇 |
2021年 | 382篇 |
2020年 | 224篇 |
2019年 | 329篇 |
2018年 | 400篇 |
2017年 | 276篇 |
2016年 | 337篇 |
2015年 | 397篇 |
2014年 | 601篇 |
2013年 | 658篇 |
2012年 | 968篇 |
2011年 | 983篇 |
2010年 | 532篇 |
2009年 | 512篇 |
2008年 | 785篇 |
2007年 | 792篇 |
2006年 | 665篇 |
2005年 | 665篇 |
2004年 | 657篇 |
2003年 | 526篇 |
2002年 | 433篇 |
2001年 | 84篇 |
2000年 | 59篇 |
1999年 | 76篇 |
1998年 | 77篇 |
1997年 | 70篇 |
1996年 | 58篇 |
1995年 | 52篇 |
1994年 | 61篇 |
1993年 | 53篇 |
1992年 | 39篇 |
1991年 | 41篇 |
1990年 | 31篇 |
1989年 | 32篇 |
1988年 | 25篇 |
1987年 | 19篇 |
1986年 | 22篇 |
1985年 | 12篇 |
1984年 | 13篇 |
1983年 | 12篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1977年 | 6篇 |
1975年 | 7篇 |
1974年 | 7篇 |
1973年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
G. Bonaspetti S. Di Fabio R. Fenu L. Costa U. E. Pazzaglia 《Journal of orthopaedics and traumatology》2005,6(1):15-20
Abstract
Polyethylene (PE) wear is a focal issue in joint replacement, so it is essential to understand how it takes place in vivo. PE wear is a multifactorial process with a complex interaction of variables related to the materials used, the mechanical conditions, operative procedures for implantation, activity of the patient and use of prosthesis. We retrieved 65 PE inserts with the respective femoral and tibial components (50 inserts of total knee prostheses and 15 monocompartmental prostheses) from first revision surgeries. The average age of the patients was 68.3 years; the average time to revision was 41.5 months. Macroscopic observation considered the grade, topography and type of wear. Degradation was also studied with scanning electron microscopy. No direct relationship was found between the level of wear and the survival of total or monocompartmental knee prostheses. The duration of 11 (22%) total prosthetic inserts with grade 2 wear was 42.6 months vs. 51.5 months of 17 (34%) total inserts with grade 1 wear. However, study of the relationship between wear grade and wear topography in total inserts suggested that there was a significant connection. In fact, the 22 (44%) prostheses with central and symmetrical wear never showed wear greater than grade 1. Instead, of the remaining 28 prostheses (56%) without central and symmetric wear, only 3 had grade 0 wear. Finally, considering the relationship between wear grade and type of wear, all 18 inserts (27.7%) with grade 2 or 3 wear had 100% delamination. In conclusion, this study suggests that the correct positioning of the prosthetic components, besides its quality, is an important cause of polyethylene wear. 相似文献
92.
Carlo Gazzera Paolo Fonio Riccardo Faletti Maria Chiara Dotto Fabio Gobbi Pierpaolo Donadio Giovanni Gandini 《La Radiologia medica》2014,119(8):549-557
Purpose
This paper discusses the technique and preliminary results of right thoracic paravertebral block (TPVB) for percutaneous thermal ablation of liver tumours.Materials and methods
Between October 2011 and August 2012 we treated 36 lesions (25 hepatocellular carcinoma and 11 metastases) in 30 patients aged 47–85 years (mean 67.5). Patients received ultrasound (US)-guided injection of 7 ml of naropin 0.75 % in T7, T9 and T11 levels, below the costo-vertebral ligament, until we observed an anterior displacement of the parietal pleura. For the subcapsular lesions, a cervical right phrenic nerve block was associated. The level of analgesia was evaluated during and after the percutaneous procedures with the Numerical Rating Scale. Finally, we investigated statistical correlations between pain and lesions (histological type, site, dimensions), and ablation time and technique (microwave or radiofrequency ablation).Results
Technical success was achieved in all patients. Despite the correct anaesthetic diffusion during the ablation, 10 patients (33.3 %) reported medium/severe pain and intravenous sedation was required. Pain was not found to correlate with any variable. No complications were observed.Conclusions
In most cases, TPVB is a safe and effective technique for conscious anaesthesia during percutaneous thermal ablation of liver tumours. Failures probably derive from left sympathetic and parasympathetic fibre stimulation. We recommend performing a TPVB in the presence of the anaesthetist. 相似文献93.
Giangaspare Mineo Domenico Attinà Martina Mughetti Caterina Balacchi Fiorella De Luca Fabio Niro Federica Ciccarese Luigi Lovato Vincenzo Russo Francesco Buia Cecilia Modolon Alessandra Manes Massimiliano Palazzini Nazareno Galiè Maurizio Zompatori 《La Radiologia medica》2014,119(9):667-673
Objective
The authors sought to evaluate the diagnostic accuracy of high-resolution computed tomography (HRCT) in the detection of pulmonary veno-occlusive disease (PVOD) in patients with pre-capillary pulmonary arterial hypertension (PAH) of unknown aetiology, and to identify the role of CT in diagnosis and therapy.Materials and methods
The CT scans of 96 patients were retrospectively reviewed and assessed for specific HRCT findings: ground-glass opacities, septal lines and mediastinal lymph nodal enlargement (short diameter ≥1 cm). According to the HRCT findings, patients were divided into PVOD-suspicious and not PVOD-suspicious. Subsequently, a clinical-instrumental evaluation was performed, and the response to therapy and histopathological reports were evaluated.Results
Radiological evaluation based on HRCT findings revealed 29 patients as PVOD-suspicious and 67 as not PVOD-suspicious. The final diagnosis was PVOD in 22 patients and idiopathic PAH in 74 patients. The CT scan showed 95.5 % sensitivity, 89 % specificity, 72.5 % positive predictive value, and 98.5 % negative predictive value, with a diagnostic accuracy of 90.5 % in identifying patients with PVOD.Conclusions
Chest CT can be considered a screening test in the assessment of patients with PAH of unknown aetiology, and the radiologist can help the clinician to identify patients with CT findings that make PVOD highly probable. 相似文献94.
Fabio Tortora Mariaevelina Prudente Mario Cirillo Andrea Elefante Maria Paola Belfiore Francesco Romano Salvatore Cappabianca Carlo Carella Sossio Cirillo 《Neuroradiology》2014,56(5):353-361
Introduction
In Graves’ Ophthalmopathy, it is important to distinguish active inflammatory phase, responsive to immunosuppressive treatment, from fibrotic unresponsive inactive one. The purpose of this study is, first, to identify the relevant orbital magnetic resonance imaging signal intensities before treatment, so to classify patients according to their clinical activity score (CAS), discriminating inactive (CAS?<?3) from active Graves’ Ophthalmopathy (GO) (CAS?>?3) subjects and, second, to follow post-steroid treatment disease.Methods
An observational study was executed on 32 GO consecutive patients in different phases of disease, based on clinical and orbital Magnetic Resonance Imaging parameters, compared to 32 healthy volunteers. Orbital Magnetic Resonance Imaging was performed on a 1.5 tesla Magnetic Resonance Unit by an experienced neuroradiologist blinded to the clinical examinations.Results
In pre-therapy patients, compared to controls, a medial rectus muscle statistically significant signal intensity ratio (SIR) in short-time inversion recovery (STIR) (long TR/TE) sequence was found, as well as when comparing patients before and after treatment, both medial and inferior rectus muscle SIR resulted significantly statistically different in STIR. These increased outcomes explain the inflammation oedematous phase of disease, moreover after steroid administration, compared to controls; patients presented lack of that statistically significant difference, thus suggesting treatment effectiveness.Conclusion
In our study, we proved STIR signal intensities increase in inflammation oedematous phase, confirming STIR sequence to define active phase of disease with more sensibility and reproducibility than CAS alone and to evaluate post-therapy involvement. 相似文献95.
Marco Vivarelli Alessandro Cucchetti Fabio Piscaglia Giuliano La Barba Luigi Bolondi Antonino Cavallari Antonio Daniele Pinna 《Liver transplantation》2005,11(5):497-503
To confirm recent observations about the relationship between immunosuppression and the recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT), we retrospectively analyzed 70 consecutive HCC patients who underwent LT and received cyclosporine (CsA)-based immunosuppression. CsA trough blood levels, measured with the same technique (fluorescence polarization immunoassay), were analyzed at different time points after transplantation. The exposure to the drug was calculated with the trapezoidal rule in each patient. CsA was associated with steroids in 26 patients and steroids and azathioprine in 44 patients. HCC recurred in 7 patients (10.0%). Different immunosuppressive schedules (CsA and steroids vs. CsA, steroids, and azathioprine) or the cumulative dosage of steroids and azathioprine did not influence HCC recurrence that was associated instead with CsA exposure (278.3 +/- 86.4 ng/mL in recurrent vs. 169.9 +/- 33.3 in tumor-free patients; P < 0.001); CsA exposure above 189.6 ng/mL was related to HCC recurrence at the receiver operating characteristic analysis (ROC). The relationship between CsA exposure; various clinical (sex, age, viral- vs. non-viral-related cirrhosis, preoperative vs. incidental diagnosis of HCC, alpha-fetoprotein [AFP] blood level), pathologic (pathologic tumor staging [pT] stage, presence of Milan criteria), and histologic (grading, presence of microvascular tumor invasion) parameters; and tumor recurrence were assessed. AFP (P = 0.032), microvascular tumor invasion (P = 0.044), and CsA exposure (P < 0.001) influenced recurrence-free survival at the univariate analysis; CsA exposure was the only independent prognostic determinant at multivariate analysis (P < 0.001). High CsA exposure favors tumor recurrence; CsA blood levels should be kept to the effective minimum in HCC patients. In the presence of pathologic and histologic risk factors, specific immunosuppressive protocols should be considered. 相似文献
96.
Gaya Spolverato Fabio Bagante Matthew Weiss Jin He Christopher L. Wolfgang Fabian Johnston Martin A. Makary Will Yang Steven M. Frank Timothy M. Pawlik 《Journal of gastrointestinal surgery》2016,20(12):2010-2020
Background
Delta hemoglobin (ΔHb) is defined as the difference between the preoperative Hb and the lowest post-operative Hb level. We sought to define the impact of ΔHb relative to nadir Hb levels on the likelihood of transfusion, as well as characterize the impact of ΔHb and nadir Hb on morbidity among a large cohort of patients undergoing complex hepatopancreatobiliary (HPB) surgery.Methods
Patients who underwent pancreatic or hepatic resection between January 1, 2009 and June 30, 2015 at Johns Hopkins Hospital were identified. Data on the perioperative ΔHb, nadir Hb, as well as blood utilization were obtained and analyzed. Multivariable logistic regression models were used to identify the factors associated with ΔHb and the impact of ΔHb on perioperative morbidity. A Bayesian model was used to evaluate the correlation of ΔHb and nadir Hb with the likelihood of transfusion, as well as the impact on morbidity.Results
A total of 4363 patients who underwent hepatobiliary (n?=?2200, 50.4 %) or pancreatic (n?=?2163, 49.6 %) surgery were identified. More than one quarter of patients received at least one unit of packed red blood cells (PRBC) (n?=?1187, 27.2 %). The median nadir Hb was 9.2 (IQR 7.9–10.5)?g/dL resulting in an average ΔHb of 3.4 mg/dL (IQR 2.2–4.7) corresponding to 26.3 %. Both ΔHb and nadir Hb strongly influenced provider behavior with regards to use of transfusion. Among patients with the same nadir Hb, ΔHb was strongly associated with use of transfusion; among patients who had a nadir Hb ≤6 g/dL, the use of transfusion was only 17.9 % when the ΔHb?=?10 % versus 49.1 and 80.9 % when the ΔHb was 30 or 50 %, respectively. Perioperative complications occurred in 584 patients (13.4 %) and were more common among patients with a higher value of ΔHb, as well as patients who received PRBC (both P?<?0.001).Conclusions
The combination of the Hb trigger with ΔHb was associated with transfusion practices among providers. Larger ΔHb values, as well as receipt of transfusion, were strongly associated with risk of perioperative complication following HPB surgery.97.
Fabio Rodi Emmanouil Theodorakis Georgios Touloupakis Angelo Ventura 《中华创伤杂志(英文版)》2016,19(3):156-159
Purpose: The optimal surgical treatment of displaced type B and C fractures of the proximal humerus in the elderly remains controversial. Good clinical results have been reported by plating these fractures as well as a high rate of complications. Our retrospective study aims to evaluate clinical recovery and complications using the S3 locking plate in elderly patients.Methods: Fifty-one patients older than 65 years of age, with a complex proximal humeral fracture type B or C (AO classification system), were included. Patients have been followed up for a minimum of 12months. We assessed callus formation, radiological results, clinical outcome (according to the Constant Shoulder Score System) and complications. Any difference in the clinical recovery among the 2 types of fracture pattern (B and C) was investigated.Results: The mean time of fracture healing was 12.4 weeks. The mean Constant score at 3, 6 and 12months was 68, 73 and 75 respectively. No statistically significant difference in the clinical outcome was observed between the B and C fracture patterns (p > 0.05). We noticed an overall of 5 complications (9.8%). There was no need to revision any of the implants.Conclusion: Anatomic reduction and proper plate positioning are essential for minimizing implantrelated complications. In our experience the S3 angular stability system offers a proper osteosyntesis and a good clinical recovery with a low rate of complications. 相似文献
98.
Alessandro Cucchetti MD Fabio Piscaglia MD Eugenio Caturelli MD Luisa Benvegnù MD Marco Vivarelli MD Giorgio Ercolani MD Matteo Cescon MD Matteo Ravaioli MD Gian Luca Grazi MD Luigi Bolondi MD Antonio Daniele Pinna MD 《Annals of surgical oncology》2009,16(2):413-422
The presence of cirrhosis is the only risk factor that is advocated for recurrence of hepatocellular carcinoma (HCC) 2 years
after hepatic resection compared with noncirrhotic control subjects; however, data for cohorts of exclusively patients with
cirrhosis are lacking. This study was designed to assess risk factors and annual incidence of early (<2 years) and late (>2 years)
recurrence after resection of cirrhosis and to compare these findings with those of patients with cirrhosis enrolled in HCC
surveillance programs (HCC occurrence). Data from 204 patients with cirrhosis resected for HCC and 150 surveilled for cirrhosis
were retrospectively collected and compared using propensity score matching to overcome biases of nonrandomized study. Risk
factors for early recurrence (incidence = 21.8%/year) were higher serum alpha-fetoprotein (AFP) levels, poorly differentiated
tumor, and presence of microvascular invasion (P < 0.05). Risk factors for both late recurrence (18.4%/year) and HCC occurrence (3.3%/year) were male gender, older age, and
higher serum transaminase levels; multiple primary tumors and higher AFP were additional risk factors for late recurrence
and HCC occurrence respectively (P < 0.05). After propensity adjustment, resected patients with less than two risk factors for late recurrence showed an annual
incidence of HCC (6.2%/year) similar to that of surveilled patients with ≥2 risk factors (5.8%/year; P = 0.898). Early and late recurrence of HCC for patients with cirrhosis after resection have distinct risk factors. Annual
incidence of HCC 2 years or more after resection may be similar to that of general patients because the same risk factors
are involved; assessment of these characteristics could be useful in tailoring clinical management. 相似文献
99.
Filippo Catalano Antonello Trecca Luca Rodella Francesco Lombardo Anna Tomezzoli Serena Battista Marco Silano Fabio Gaj Giovanni de Manzoni 《Surgical endoscopy》2009,23(7):1581-1586
Background Endoscopic submucosal dissection (ESD) has been developed as treatment for early gastric cancer (EGC) by Japanese authors.
However, there are no reports about its possible implementation in the Western setting. The aim of the present work is to
determine the safety and efficacy of the endoscopic treatments for EGC in an Italian cohort.
Methods Forty-five patients for a total of 48 gastric lesions were enrolled in the study. Thirty-six EMR procedures were performed
with the strip biopsy technique using a double-channel endoscope. En bloc resection refers to resection in one piece, while
piecemeal refers to resections in which the lesion was removed in multiple fragments. A total of 12 ESD were performed and
completed with IT knife. We define as curative treatment lateral and vertical margins of the resected specimens free of cancer
and repeat endoscopic finding of no recurrent disease.
Results Out of 36 EMR procedures, 10 were piecemeal resections (28%), while 26 were en bloc (72%). ESD led to en bloc resection in
11/12 cases (92%). Histological assessment of curability in the EMR group was achieved in 56% of the cases, and in 92% of
the ESD group. Mean follow-up period was 31 months (range: 12–71 months). There was no local recurrence or distant metastasis
in the curative group patients.
Conclusions These results seem to confirm the safety and the clinical efficacy of the ESD procedure in the Western world too. 相似文献
100.
Luciano Potena Francesco Grigioni Gaia Magnani Paolo Ortolani Fabio Coccolo Simonetta Sassi Koen Koessels Cinzia Marrozzini Antonio Marzocchi Samuela Carigi Anna C. Musuraca Antonio Russo Carlo Magelli Angelo Branzi 《American journal of transplantation》2005,5(9):2258-2264
Although observational studies suggest that hyperhomocysteinemia may be a risk factor for coronary allograft vasculopathy (CAV), prospective data on homocysteine-lowering interventions and CAV development are lacking. We, therefore, randomized 44 de novo heart transplant (HT) recipients to 15 mg/day of 5-methyl-tetrahydrofolate (n=22), or standard therapy (control group, n=22) to investigate the effect of homocysteine lowering on the change in coronary intimal hyperplasia during the first 12 months after transplant, as detected by intra-vascular ultrasound (IVUS). Although 12 months after HT, homocysteinemia was lower in folate-treated patients (p<0.001), coronary intimal area increased similarly in the two groups (p>0.4). Conversely, hypercholesterolemia and cytomegalovirus infection were both associated with increased intimal hyperplasia (p<0.04), independently from folate intake. Sub-group analysis revealed that folate therapy reduced intimal hyperplasia in patients with hyperhomocysteinemia before randomization (n=19; p=0.02), but increased intimal hyperplasia in patients with normal homocysteine plasma concentrations (p=0.02). This bimodal effect of folate therapy persisted significantly after adjusting for cytomegalovirus infection and hypercholesterolemia. Despite effective in prevent hyperhomocysteinemia after heart transplantation, folate therapy does not seem to affect early CAV onset. However, sub-group analysis suggests that folate therapy may delay CAV development only in patients with baseline hyperhomocysteinemia, while may favor CAV progression in recipients with normal baseline homocysteinemia. 相似文献