全文获取类型
收费全文 | 9993篇 |
免费 | 486篇 |
国内免费 | 116篇 |
专业分类
耳鼻咽喉 | 48篇 |
儿科学 | 224篇 |
妇产科学 | 299篇 |
基础医学 | 1090篇 |
口腔科学 | 133篇 |
临床医学 | 738篇 |
内科学 | 2525篇 |
皮肤病学 | 274篇 |
神经病学 | 961篇 |
特种医学 | 408篇 |
外科学 | 1815篇 |
综合类 | 23篇 |
一般理论 | 1篇 |
预防医学 | 324篇 |
眼科学 | 138篇 |
药学 | 622篇 |
中国医学 | 27篇 |
肿瘤学 | 945篇 |
出版年
2024年 | 16篇 |
2023年 | 77篇 |
2022年 | 229篇 |
2021年 | 281篇 |
2020年 | 184篇 |
2019年 | 212篇 |
2018年 | 283篇 |
2017年 | 195篇 |
2016年 | 262篇 |
2015年 | 329篇 |
2014年 | 417篇 |
2013年 | 548篇 |
2012年 | 838篇 |
2011年 | 801篇 |
2010年 | 532篇 |
2009年 | 431篇 |
2008年 | 699篇 |
2007年 | 700篇 |
2006年 | 630篇 |
2005年 | 622篇 |
2004年 | 585篇 |
2003年 | 469篇 |
2002年 | 447篇 |
2001年 | 46篇 |
2000年 | 40篇 |
1999年 | 43篇 |
1998年 | 89篇 |
1997年 | 56篇 |
1996年 | 59篇 |
1995年 | 53篇 |
1994年 | 60篇 |
1993年 | 42篇 |
1992年 | 38篇 |
1991年 | 39篇 |
1990年 | 32篇 |
1989年 | 18篇 |
1988年 | 20篇 |
1987年 | 15篇 |
1986年 | 13篇 |
1985年 | 11篇 |
1984年 | 21篇 |
1983年 | 19篇 |
1982年 | 11篇 |
1981年 | 9篇 |
1980年 | 11篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1975年 | 4篇 |
1926年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Sebastiano Mercadante Paolo Marchetti Arturo Cuomo Augusto Caraceni Rocco Domenico Mediati Massimo Mammucari Silvia Natoli Marzia Lazzari Mario Dauri Mario Airoldi Giuseppe Azzarello Mauro Bandera Livio Blasi Giacomo Cartenì Bruno Chiurazzi Benedetta Veruska Pierpaola Costanzo Daniela Degiovanni Flavio Fusco Vittorio Guardamagna Vincenzo Iaffaioli Simeone Liguori Vito Lorusso Sergio Mameli Rodolfo Mattioli Teresita Mazzei Rita Maria Melotti Valentino Menardo Danilo Miotti Stefano Moroso Stefano De Santis Remo Orsetti Alfonso Papa Sergio Ricci Alessandro Fabrizio Sabato Elvira Scelzi Michele Sofia Giuseppe Tonini Federica Aielli Alessandro Valle On behalf of the IOPS MS study group 《Advances in therapy》2017,34(1):120-135
Introduction
An ongoing national multicenter survey [Italian Oncologic Pain multiSetting Multicentric Survey (IOPS-MS)] is evaluating the characteristics of breakthrough cancer pain (BTP) in different clinical settings. Preliminary data from the first 1500 cancer patients with BTP enrolled in this study are presented here.Methods
Thirty-two clinical centers are involved in the survey. A diagnosis of BTP was performed by a standard algorithm. Epidemiological data, Karnofsky index, stage of disease, presence and sites of metastases, ongoing oncologic treatment, and characteristics of background pain and BTP and their treatments were recorded. Background pain and BTP intensity were measured. Patients were also questioned about BTP predictability, BTP onset (≤10 or >10 min), BTP duration, background and BTP medications and their doses, time to meaningful pain relief after BTP medication, and satisfaction with BTP medication. The occurrence of adverse reactions was also assessed, as well as mucosal toxicity.Results
Background pain was well controlled with opioid treatment (numerical rating scale 3.0 ± 1.1). Patients reported 2.5 ± 1.6 BTP episodes/day with a mean intensity of 7.5 ± 1.4 and duration of 43 ± 40 min; 977 patients (65.1%) reported non-predictable BTP, and 1076 patients (71.7%) reported a rapid onset of BTP (≤10 min). Higher patient satisfaction was reported by patients treated with fast onset opioids.Conclusions
These preliminary data underline that the standard algorithm used is a valid tool for a proper diagnosis of BTP in cancer patients. Moreover, rapid relief of pain is crucial for patients’ satisfaction. The final IOPS-MS data are necessary to understand relationships between BTP characteristics and other clinical variables in oncologic patients.Funding
Molteni Farmaceutici, Italy.992.
Piccirillo G Naso C Moisè A Lionetti M Nocco M Di Carlo S De Laurentis T Magrì D Cacciafesta M Marigliano V 《Clinical science (London, England : 1979)》2004,107(1):55-61
Autonomic nervous system control in subjects with vasovagal syncope is controversial. In the present study, we used short-term spectral analysis to evaluate autonomic control in subjects with recurrent vasovagal syncope. We assessed the ability of spectral indices of HR (heart rate) variability to predict tilt-test responses. A series of 47 outpatients with recurrent vasovagal syncope and with positive responses to head-up tilt testing underwent a further study of RR variability during controlled breathing at rest and during tilt testing. During controlled breathing, RR interval variability of total power (TP(RR); P<0.001), low-frequency power (LF(RR); P<0.05), high-frequency power (HF(RR); P<0.001) and HF expressed in normalized units (HFnu(RR); P<0.001) were all higher, and LF expressed in normalized units (LFnu(RR)) and LF/HF ratio were lower in subjects with vasovagal syncope than in controls (P<0.001). To assess the ability of spectral components of RR variability to predict tilt-test responses, we prospectively studied 109 subjects with recurrent vasovagal syncope. The two normalized measures, HFnu(RR) and LFnu(RR), determined during controlled breathing alone predicted a positive tilt-test response (sensitivity, 76%; specificity, 99%; positive predictive value, 96%; and negative predictive value, 90%). During tilting, subjects with vasovagal syncope had lower SBP (systolic blood pressure; P<0.05), LF component of peak SBP variability (LF(SBP)) and LFnu(RR) than controls, and higher TP(RR), HF(RR), HFnu(RR) and alpha HF (P<0.001). These spectral data indicate that vagal sinus modulation is increased at rest in subjects with vasovagal syncope. Spectral analysis of RR variability during controlled breathing, a procedure that predicts tilt-test responses, could be a useful guide in choosing the method of tilt testing. 相似文献
993.
Lorenzo Loffredo Vincenzo Arienti Gianpaolo Vidili Chiara Cogliati Simona Battaglia Ludovica Perri Rosella Di Giulio Sciaila Bernardini Maria Luna Summa Angela Sciacqua Francesco Perticone Maria Boddi Giovanni Di Minno Corrado Lodigiani Antonello Pietrangelo Alessio Farcomeni Francesco Violi 《Mayo Clinic proceedings. Mayo Clinic》2019,94(1):37-43
Objective
To evaluate the effect of hospitalization on deep venous thrombosis (DVT) rate by the cumulative incidence of DVT in the proximal venous tract of the lower limbs at admission and discharge.Methods
The AURELIO (rAte of venoUs thRombosis in acutEly iLl patIents hOspitalized in internal medicine wards) multicenter observational study was carried out in hospital-university internal medicine wards including consecutive acutely ill medical patients. Patients underwent compression ultrasonography (CUS) of proximal lower limb veins at admission and discharge. The occurrence of DVT was the primary end point of the study.Results
Among 1340 patients, 26 (1.9%; 95% CI, 1.3%-2.8%) had asymptomatic DVT at admission and were excluded. During the follow-up, 144 patients were excluded because of hospitalization less than 5 days. The remaining 1170 patients underwent a CUS at discharge. Two hundred fifty (21%) underwent prophylaxis with parenteral anticoagulants; the remaining 920 (79%) were not treated with anticoagulants. The mean length of hospitalization was 13±8 days. Compared with patients without prophylaxis, those treated with parenteral anticoagulants had a higher incidence of active cancer, heart and respiratory failure, pneumonia, renal failure, previous venous thromboembolism, reduced mobility, and elderly age. During the hospital stay, 3 patients with a negative CUS at admission experienced DVT in the proximal tract (0.025%, rate of 1 per 5017 patient-days); 2 of them were in prophylaxis with parenteral anticoagulants.Conclusion
We provide evidence that in the real world acutely ill medical patients display more than 90% (1.9%) asymptomatic DVT at admission, whereas the intrahospital DVT occurrence is very low. This suggests a novel diagnostic workup and a careful reanalysis of anticoagulant prophylaxis. 相似文献994.
Rapamycin stimulates apoptosis of childhood acute lymphoblastic leukemia cells 总被引:6,自引:1,他引:6 下载免费PDF全文
Avellino R Romano S Parasole R Bisogni R Lamberti A Poggi V Venuta S Romano MF 《Blood》2005,106(4):1400-1406
The phosphatidyl-inositol 3 kinase (PI3k)/Akt pathway has been implicated in childhood acute lymphoblastic leukemia (ALL). Because rapamycin suppresses the oncogenic processes sustained by PI3k/Akt, we investigated whether rapamycin affects blast survival. We found that rapamycin induces apoptosis of blasts in 56% of the bone marrow samples analyzed. Using the PI3k inhibitor wortmannin, we show that the PI3k/Akt pathway is involved in blast survival. Moreover, rapamycin increased doxorubicin-induced apoptosis even in nonresponder samples. Anthracyclines activate nuclear factor kappaB (NF-kappaB), and disruption of this signaling pathway increases the efficacy of apoptogenic stimuli. Rapamycin inhibited doxorubicin-induced NF-kappaB in ALL samples. Using a short interfering (si) RNA approach, we demonstrate that FKBP51, a large immunophilin inhibited by rapamycin, is essential for drug-induced NF-kappaB activation in human leukemia. Furthermore, rapamycin did not increase doxorubicin-induced apoptosis when NF-kappaB was overexpressed. In conclusion, rapamycin targets 2 pathways that are crucial for cell survival and chemoresistance of malignant lymphoblasts--PI3k/Akt through the mammalian target of rapamycin and NF-kappaB through FKBP51--suggesting that the drug could be beneficial in the treatment of childhood ALL. 相似文献
995.
996.
Piccirillo G Nocco M Lionetti M Moisè A Naso C Marigliano V Cacciafesta M 《American heart journal》2002,143(4):703-710
Background Cases of sudden death associated with sildenafil citrate use have been reported in men with coronary artery disease. The aim of this study was to investigate the drug's effect on cardiac repolarization and sinus autonomic and vascular control in men with mild chronic heart failure (CHF; New York Heart Association classification II). Changes in these variables could predispose patients to malignant ventricular arrhythmias. Method We measured QT dispersion, the QT-RR slope, and the index of QT variability (QTVI) and analyzed spectral power of RR and systolic blood pressure variability in 10 men with dilated cardiomyopathy and in 10 control subjects after administration of a single 50-mg oral dose of sildenafil citrate or placebo at rest (not followed with any attempt at intercourse). Results In both groups, oral sildenafil citrate decreased the systolic blood pressure (P <.05) and increased the heart rate (P <.05). In subjects with CHF, it also increased the QT-RR (P <.001) and QTVI (from −0.45 ± 0.07 to −0.27 ± 0.07; P <.001), but in controls, it increased the QTVI (from −1.20 ± 0.08 to −0.78 ± .014; P < .001). In these subjects and controls, oral sildenafil citrate induced a significant reduction in high frequency, expressed in absolute power (subjects with CHF: from 4.04 ± 0.14 to 3.43 ± 0.16 natural logarithm ms2; P <.001; controls: from 5.61 ± 0.44 to 4.98 ± 0.32 natural logarithm ms2; P <.05) and in normalized units (P <.05). In subjects with CHF but not in controls, it also significantly increased the low frequency to high frequency ratio (from 1.3 ± 0.12 to 1.89 ± 0.16; P <.001) and low frequency expressed in normalized units (P <.05).Sildenafil citrate caused no significant changes in the QT interval or dispersion. Conclusion These findings indicate that, in men with heart failure, sildenafil citrate reduces vagal modulation and increases sympathetic modulation, probably through its reflex vasodilatory action. The autonomic system changes induced with sildenafil citrate could alter QT dynamics. Both changes could favor the onset of lethal ventricular arrhythmias. At the dose usually taken for erectile dysfunction, sildenafil citrate has no direct effect on cardiac repolarization (QT interval or dispersion). (Am Heart J 2002;143:703-10.) 相似文献
997.
Suppression of tumor growth and cell proliferation by p13II, a mitochondrial protein of human T cell leukemia virus type 1 下载免费PDF全文
Silic-Benussi M Cavallari I Zorzan T Rossi E Hiraragi H Rosato A Horie K Saggioro D Lairmore MD Willems L Chieco-Bianchi L D'Agostino DM Ciminale V 《Proceedings of the National Academy of Sciences of the United States of America》2004,101(17):6629-6634
Human T cell leukemia virus type 1 encodes an "accessory" protein named p13(II) that is targeted to mitochondria and triggers a rapid flux of K(+) and Ca(2+) across the inner membrane. In this study, we investigated the effects of p13(II) on tumorigenicity in vivo and on cell growth in vitro. Results showed that p13(II) significantly reduced the incidence and growth rate of tumors arising from c-myc and Ha-ras-cotransfected rat embryo fibroblasts. Consistent with these findings, HeLa-derived cell lines stably expressing p13(II) exhibited markedly reduced tumorigenicity, as well as reduced proliferation at high density in vitro. Mixed culture assays revealed that the phenotype of the p13(II) cell lines was dominant over that of control lines and was mediated by a heat-labile soluble factor. The p13(II) cell lines exhibited an enhanced response to Ca(2+)-mediated stimuli, as measured by increased sensitivity to C2-ceramide-induced apoptosis and by cAMP-responsive element-binding protein (CREB) phosphorylation in response to histamine. p13(II)-expressing Jurkat T cells also exhibited reduced proliferation, suggesting that the protein might exert similar effects in T cells, the primary target of HTLV-1 infection. These findings provide clues into the function of p13(II) as a negative regulator of cell growth and underscore a link between mitochondria, Ca(2+) signaling, and tumorigenicity. 相似文献
998.
Efficacy of main pancreatic-duct endoscopic drainage in patients with chronic pancreatitis, continuous pain, and dilated duct 总被引:4,自引:0,他引:4
Gabbrielli A Pandolfi M Mutignani M Spada C Perri V Petruzziello L Costamagna G 《Gastrointestinal endoscopy》2005,61(4):576-581
BACKGROUND: The aim of endoscopic treatment in patients with chronic pancreatitis is to achieve decompression of the pancreatic duct, because duct obstruction with increased pressure within the duct is one of the leading causes of pain in these patients. The majority of patients suffer from relapsing pain, thus making it difficult to evaluate the efficacy of therapy. The outcome of endoscopic treatment on pain has been evaluated in patients with continuous pain (present for more than 1 month, at least 5 days per week, requiring daily analgesic therapy) and dilated duct. METHODS: Of 343 patients who underwent endotherapy for chronic pancreatitis in a 15-year period, 22 (6.4%)(19 men, mean age 48 years, alcohol abuse 14) had continuous pain and a dilated pancreatic duct. RESULTS: Endotherapy was successful in all patients, with no procedure-related mortality and only mild complications. Pain disappeared, and analgesics could be discontinued in all patients immediately after endotherapy. Six patients are pain free after a mean period of 5.5 years. One pain-free patient died after 3.4 years from myocardial infarction. Five patients were successfully endoscopically re-treated for pain relapses. Four patients underwent surgery for frequent pain relapses after a mean period of 2.5 years. Six patients were lost to follow-up. CONCLUSIONS: Endotherapy should be considered as the initial treatment of choice in patients with chronic pancreatitis, dilated duct, and continuous pain. 相似文献
999.
Elevated myocardial and lymphocyte GRK2 expression and activity in human heart failure. 总被引:8,自引:0,他引:8
Guido Iaccarino Emanuele Barbato Ersilia Cipolletta Vincenzo De Amicis Kenneth B Margulies Dario Leosco Bruno Trimarco Walter J Koch 《European heart journal》2005,26(17):1752-1758
AIMS: The G protein-coupled receptor kinase-2 (GRK2 or beta-ARK1) regulates beta-adrenergic receptors (beta-ARs) in the heart, and its cardiac expression is elevated in human heart failure (HF). We sought to determine whether myocardial levels and activity of GRK2 could be monitored using white blood cells, which have been used to study cardiac beta-ARs. Moreover, we were interested in determining whether GRK2 levels in myocardium and lymphocytes may be associated with beta-AR dysfunction and HF severity. METHODS AND RESULTS: In myocardial biopsies from explanted failing human hearts, GRK activity was inversely correlated with beta-AR-mediated cAMP production (R(2)=-0.215, P<0.05, n=24). Multiple regression analysis confirmed that GRK activity participates with beta-AR density to regulate catecholamine-sensitive cAMP responses. Importantly, there was a direct correlation between myocardial and lymphocytes GRK2 activity (R(2)=0.5686, P<0.05, n=10). Lymphocyte GRK activity was assessed in HF patients with various ejection fractions (EFs) (n=33), and kinase activity was significantly higher in patients with lower EFs and was higher with increasing NYHA class (P<0.001). CONCLUSION: Myocardial GRK2 expression and activity are mirrored by lymphocyte levels of this kinase, and its elevation in HF is associated with the loss of beta-AR responsiveness and appears to increase with disease severity. Therefore, lymphocytes may provide a surrogate for monitoring cardiac GRK2 in human HF. 相似文献
1000.
Pola E Gaetani E Pola R Papaleo P Flex A Aloi F De Santis V Santoliquido A Pola P 《Journal of the American Geriatrics Society》2002,50(12):2025-2028
OBJECTIVES: To evaluate how angiotensin-converting enzyme (ACE) gene polymorphism is associated with perioperative blood loss in hip arthroplasty in a geriatric population. DESIGN: A case-control study of subjects consecutively undergoing total hip arthroplasty. SETTING: A department of orthopedic surgery in Italy. PARTICIPANTS: One hundred five patients, mean age +/- standard deviation 68.6 +/- 10.4, undergoing total hip arthroplasty. MEASUREMENTS: ACE gene polymorphism was analyzed using polymerase chain reaction. Decrement of hemoglobin (Hb) and hematocrit (Ht) was calculated as the difference between the preoperative and the lowest postoperative value, measured 1, 2, and 3 days after surgery. Total blood loss was calculated as the sum of intra- and postoperative blood loss. RESULTS: Patients carrying the deletion homozygous and insertion/deletion heterozygous genotypes of the ACE gene show a higher decrement of Hb (P <.01) and Ht (P <.01) and higher total blood loss (P <.007) after hip surgery than subjects carrying the insertion (II) homozygous. The role of ACE gene polymorphism seems hypertension independent. Logistic regression analysis showed that II genotype reduces total blood loss. CONCLUSIONS: This is the largest study evaluating the distribution of ACE gene genotypes in patients undergoing hip arthroplasty and the first investigating the association between bleeding and ACE gene polymorphism. Our data suggest that II genotype is associated with lower total blood loss. 相似文献