全文获取类型
收费全文 | 2106篇 |
免费 | 109篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 18篇 |
妇产科学 | 94篇 |
基础医学 | 313篇 |
口腔科学 | 15篇 |
临床医学 | 198篇 |
内科学 | 339篇 |
皮肤病学 | 24篇 |
神经病学 | 221篇 |
特种医学 | 103篇 |
外科学 | 297篇 |
综合类 | 9篇 |
一般理论 | 2篇 |
预防医学 | 80篇 |
眼科学 | 139篇 |
药学 | 115篇 |
中国医学 | 8篇 |
肿瘤学 | 222篇 |
出版年
2023年 | 21篇 |
2022年 | 37篇 |
2021年 | 41篇 |
2020年 | 34篇 |
2019年 | 38篇 |
2018年 | 43篇 |
2017年 | 25篇 |
2016年 | 53篇 |
2015年 | 51篇 |
2014年 | 82篇 |
2013年 | 102篇 |
2012年 | 128篇 |
2011年 | 151篇 |
2010年 | 95篇 |
2009年 | 99篇 |
2008年 | 152篇 |
2007年 | 143篇 |
2006年 | 136篇 |
2005年 | 158篇 |
2004年 | 134篇 |
2003年 | 146篇 |
2002年 | 132篇 |
2001年 | 31篇 |
2000年 | 17篇 |
1999年 | 24篇 |
1998年 | 17篇 |
1997年 | 22篇 |
1996年 | 15篇 |
1995年 | 12篇 |
1994年 | 11篇 |
1993年 | 6篇 |
1992年 | 12篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1969年 | 2篇 |
1966年 | 1篇 |
1926年 | 1篇 |
排序方式: 共有2221条查询结果,搜索用时 14 毫秒
81.
I. Everall F. Vaida N. Khanlou D. Lazzaretto C. Achim S. Letendre D. Moore R. Ellis M. Cherner B. Gelman S. Morgello E. Singer I. Grant E. Masliah 《Journal of neurovirology》2009,15(5-6):360-370
The objective of this study was to examine the spectrum of human immunodeficiency virus (HIV) brain pathology and its clinical correlates in the antiretroviral era. We carried out a cross-sectional survey, analyzing prospective clinical and neuropathological data collected by the National NeuroAIDS Tissue Consortium (NNTC), comprising 589 brain samples from individuals with advanced HIV disease collected from 1999 onwards. We assessed gender, ethnicity/race, mode of transmission, age, year of death, nadir CD4, plasma viral load, last antiretroviral regimen, presence of parenchymal HIV brain pathology, HIV-associated neurocognitive disorder, and major depressive disorder. We compared cohort demographic variables with Centers for Disease Control and Prevention US HIV/AIDS statistics and examined associations of parenchymal HIV brain pathology with demographic, clinical, and HIV disease factors. With regard to Centers for Disease Control and Prevention US data, the NNTC was similar in age distribution, but had fewer females and African Americans and more Hispanics and men who have sex with men. Only 22% of the brains examined were neuropathologically normal. Opportunistic infections occurred in 1% to 5% of the cohort. Parenchymal HIV brain pathology was observed in 17.5% of the cohort and was associated with nadir CD4 and plasma viral load. Brains without parenchymal HIV brain pathology often had other noninfectious findings or minimal nondiagnostic abnormalities that were associated with HIV-associated neurocognitive disorder. Clinically, 60% of the cohort reported a lifetime episode of major depressive disorder and 88% had a HIV-associated neurocognitive disorder. No pathological finding correlated with major depressive disorder. Both antiretroviral treatment regimen and elevated plasma HIV viral load were associated with presence of parenchymal HIV brain pathology; however, multivariate analyses suggest a stronger association with plasma viral load. The frequency of HIV brain pathology was lower than previous pre-antiretroviral reports, and was predicted by lower nadir CD4 and higher plasma viral load. Noninfectious pathologies and minimal changes correlated with HIV-associated neurocognitive disorder, suggesting a shift in pathogenesis from florid HIV replication to other, diverse mechanisms. 相似文献
82.
Mannion Anne F. Mariaux Francine Reitmeir Raluca Fekete Tamas F. Haschtmann Daniel Loibl Markus Jeszenszky Dezsö Kleinstück Frank S. Porchet François Elfering Achim 《European spine journal》2020,29(8):1935-1952
European Spine Journal - Depression, anxiety, catastrophising, and fear-avoidance beliefs are key "yellow flags" (YFs) that predict a poor outcome in back patients. Most surgeons... 相似文献
83.
Jeske C Raedler C von Goedecke A Mayr A Hinterberger G Aspoeck Ch Lass-Floerl C Benzer A 《Anesthesia and analgesia》2003,97(4):940-3, table of contents
Catheter-related bloodstream infections (CRBSI) are a common problem in patients after central venous catheterization. Using DNA analysis we compared bacteria found on the tip of central venous catheters removed because of clinical signs of CRBSI with bacteria found on needle, dilator, and guidewire used for insertion of these catheters. In five of seven central venous catheters removed because of clinical signs of CRBSI, bacteria on the catheter tip were genetically identical to bacteria found on the insertion device, proving that catheter contamination in these cases was caused by contacting bacteria during the initial puncture. These findings may be important for antibiotic prophylaxis or therapy in patients at risk for CRBSI. IMPLICATIONS: In five of seven central venous catheters removed because of clinical signs of catheter-related blood infections, DNA analysis showed bacteria found on the catheter tip to be identical with bacteria found on the puncture kits used for insertion of these catheters. 相似文献
84.
Achim Seeger Michael Fenchel Ulrich Kramer Christiane Bretschneider Florian Grimm Bernhard Klumpp Albertus Scheule Bernd Balletshofer Claus D. Claussen Stephan Miller 《European radiology》2010,20(4):838-845
Objectives
To longitudinally assess the value of cardiac functional and viability imaging as a supplement to MR angiography in patients with atherosclerotic disease.Methods
Cardiac MRI was performed in 195 consecutive patients with symptomatic peripheral arterial disease. Of these, 186 patients were followed for 22?±?5 months for the presence of cardiac events (cardiac death, acute coronary syndrome and hospitalisation as a result of congestive heart failure).Results
Myocardial viability imaging showed a high prevalence of known (n?=?31) and occult myocardial infarctions (MI) (n?=?26). Cardiac events occurred more often in patients with reduced ventricular function (ejection fraction (EF) less than 40%, cardiac event in 4/8 patients; EF 40–55%, cardiac event in 10/40 patients; EF greater than 55%, cardiac event in 15/138 patients) as well as in patients with occult MI (8/25 patients) and known MI (11/30 patients). In patients with normal function, the detection of a previous MI was of high relevance to prognosis.Conclusions
Both reduced EF and the presence of MI influence patients’ prognoses. Performing cardiac MRI in this patient population may influence further patient management including intensified risk factor intervention. 相似文献85.
Janusz Witowski Katarzyna Korybalska Krzysztof Ksiazek Justyna Wisniewska-Elnur Achim J?rres Cristina Lage Thomas P Schaub Jutta Passlick-Deetjen Andrzej Breborowicz Alicja Grzegorzewska Andrzej Ksiazek Tomasz Liberek Monika Lichodziejewska-Niemierko Maria Majdan Boleslaw Rutkowski Tomasz Stompór Wladyslaw Sulowicz 《Nephrology, dialysis, transplantation》2004,19(4):917-924
BACKGROUND: In vitro experiments point to a better biocompatibility profile of new pH-neutral peritoneal dialysis fluids (PDFs) containing low levels of glucose degradation products (GDPs). The present study examines the impact on human peritoneal mesothelial cells (HPMCs) of equilibrated dialysates obtained during dialysis with either conventional or new PDFs. METHODS: Peritoneal dialysate was collected from 17 patients participating in a randomized, controlled, cross-over trial comparing a pH-neutral low-GDP solution (Balance) to a conventional solution (S-PDF). All patients were treated sequentially for 3 months with both PDFs. At the end of each treatment phase, peritoneal effluent was drained after a timed 10 h dwell. Samples of dialysate were then mixed with standard culture medium and added to in vitro cultures of HPMCs from healthy donors. Cells were assessed for proliferation, viability and cytokine release. RESULTS: Proliferation and viability of HPMCs were better preserved in the presence of effluent obtained during dialysis with Balance (P<0.046 and P<0.035, respectively). The proliferative response of HPMCs correlated with the concentration of fibronectin in dialysates (P = 0.0024). Effluent drained following a 3 month dialysis with Balance contained significantly increased levels of fibronectin (P = 0.004) and CA125 antigen (P = 0.0004) compared with S-PDF. There was no significant difference in constitutive and stimulated cytokine (IL-6, MCP-1, VEGF) synthesis by HPMCs treated with either Balance- or S-PDF-derived effluents. CONCLUSIONS: These results suggest that therapy with new pH-neutral low-GDP solutions contribute to an intraperitoneal milieu that improves mesothelial cell proliferation and viability. It may positively impact on the preservation of the peritoneal membrane integrity during long-term dialysis. 相似文献
86.
Lars Richter Peter Trillenberg Achim Schweikard Alexander Schlaefer 《Brain stimulation》2013,6(3):315-321
BackgroundTranscranial Magnetic Stimulation (TMS) is based on a changing magnetic field inducing an electric field in the brain. Conventionally, the TMS coil is mounted to a static holder and the subject is asked to avoid head motion. Additionally, head resting frames have been used. In contrast, our robotized TMS system employs active motion compensation (MC) to maintain the correct coil position.Objective/hypothesisWe study the effect of patient motion on TMS. In particular, we compare different coil positioning techniques with respect to the induced electric field.MethodsWe recorded head motion for six subjects in three scenarios: (a) avoiding head motion, (b) using a head rest, and (c) moving the head freely. Subsequently, the motion traces were replayed using a second robot to move a sensor to measure the electric field in the target region. These head movements were combined with 2 types of coil positioning: (1) using a coil holder and (2) using robotized TMS with MC.ResultsAfter 30 min the induced electric field was reduced by 32.0% and 19.7% for scenarios (1a) and (1b), respectively. For scenarios (2a)–(2c) it was reduced by only 4.9%, 1.4% and 2.0%, respectively, which is a significant improvement (P < 0.05). Furthermore, the orientation of the induced field changed by 5.5°, 7.6°, 0.4°, 0.2°, 0.2° for scenarios (1a)–(2c).ConclusionWhile none of the scenarios required rigid head fixation, using a simple holder to position a coil during TMS can lead to substantial deviations in the induced electric field. In contrast, robotic motion compensation results in clinically acceptable positioning throughout treatment. 相似文献
87.
Wyss MT Honer M Späth N Gottschalk J Ametamey SM Weber B von Schulthess GK Buck A Kaim AH 《Nuclear medicine and biology》2004,31(7):875-882
Our aim was to determine the influence of antibiotic treatment using ceftriaxone on [18F]-fluorodeoxyglucose (FDG) uptake in experimental soft tissue infections. PET scans were performed in two groups (treated n=4; non-treated n=4) at days 3, 5, and 6 after inoculation of the infection. Additional autoradiography was performed in four animals at day 7 and in three animals at day 11. The difference of FDG uptake on day 5 (after three days of antibiotic treatment) between both groups proved to be significant (df=6; T=2.52; p=0.045). FDG uptake determined at the other days did not reveal significant difference between the two groups. It seems to be possible that the effect of antibiotic treatment on FDG uptake is less evident than reported for therapy monitoring of cancer treatment. The change of FDG uptake over time in treated and untreated infections is complex and further in vivo experiments have to be initiated to investigate the potential value of clinical FDG PET in therapy monitoring of infection. 相似文献
88.
Weranja Ranasinghe Daniel D. Shapiro Hyunsoo Hwang Xuemei Wang Chad A. Reichard Mohamed Elsheshtawi Mary F. Achim Tharakeswara Bathala Chad Tang Ana Aparicio Shi-Ming Tu Nora Navone Timothy C. Thompson Louis Pisters Patricia Troncoso John W. Davis Brian F. Chapin 《European urology》2021,79(2):298-306
BackgroundDuctal prostate adenocarcinoma (DAC) is a rare, aggressive, histologic variant of prostate cancer that is treated with conventional therapies, similar to high-risk prostate adenocarcinoma (PAC).ObjectiveTo assess the outcomes of men undergoing definitive therapy for DAC or high-risk PAC and to explore the effects of androgen deprivation therapy (ADT) in improving the outcomes of DAC.Design, setting, and participantsA single-center retrospective review of all patients with cT1–4/N0–1 DAC from 2005 to 2018 was performed. Those undergoing radical prostatectomy (RP) or radiotherapy (RTx) for DAC were compared with cohorts of high-risk PAC patients.Outcome measurements and statistical analysisMetastasis-free survival (MFS) and overall survival (OS) rates were analyzed using Kaplan-Meier and Cox regression models.Results and limitationsA total of 228 men with DAC were identified; 163 underwent RP, 34 underwent RTx, and 31 had neoadjuvant therapy prior to RP. In this study, 163 DAC patients and 155 PAC patients undergoing RP were compared. Similarly, 34 DAC patients and 74 PAC patients undergoing RTx were compared. DAC patients undergoing RP or RTx had worse 5-yr MFS (75% vs 95% and 62% vs 93%, respectively, p < 0.001) and 5-yr OS (88% vs 97% and 82% vs 100%, respectively, p < 0.05) compared with PAC patients. In the 76 men who received adjuvant/salvage ADT after RP, DAC also had worse MFS and OS than PAC (p < 0.01). A genomic analysis revealed that 10/11 (91%) DACs treated with ADT had intrinsic upregulation of androgen-resistant pathways. Further, none of the DAC patients (0/15) who received only neoadjuvant ADT prior to RP had any pathologic downgrading. The retrospective nature was a limitation.ConclusionsMen undergoing RP or RTx for DAC had worse outcomes than PAC patients, regardless of the treatment modality. Upregulation of several intrinsic resistance pathways in DAC rendered ADT less effective. Further evaluation of the underlying biology of DAC with clinical trials is needed.Patient summaryThis study demonstrated worse outcomes among patients with ductal adenocarcinoma of the prostate than among high-grade prostate adenocarcinoma patients, regardless of the treatment modality. 相似文献
89.
Schnake Klaus John Pumberger Matthias Rappert Denis Götz Achim Zolotoverkh Oleksandr Waligora Rita Scheyerer Max Joseph 《European spine journal》2022,31(5):1331-1331
European Spine Journal - 相似文献
90.
Richter-Ehrenstein C Tombokan F Fallenberg EM Schneider A Denkert C 《Breast (Edinburgh, Scotland)》2011,20(6):501-504