全文获取类型
收费全文 | 473篇 |
免费 | 39篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 6篇 |
妇产科学 | 2篇 |
基础医学 | 73篇 |
口腔科学 | 3篇 |
临床医学 | 61篇 |
内科学 | 120篇 |
皮肤病学 | 13篇 |
神经病学 | 56篇 |
特种医学 | 4篇 |
外科学 | 56篇 |
综合类 | 2篇 |
预防医学 | 29篇 |
眼科学 | 6篇 |
药学 | 27篇 |
肿瘤学 | 54篇 |
出版年
2024年 | 1篇 |
2023年 | 12篇 |
2022年 | 11篇 |
2021年 | 28篇 |
2020年 | 18篇 |
2019年 | 21篇 |
2018年 | 29篇 |
2017年 | 23篇 |
2016年 | 22篇 |
2015年 | 25篇 |
2014年 | 25篇 |
2013年 | 34篇 |
2012年 | 33篇 |
2011年 | 35篇 |
2010年 | 21篇 |
2009年 | 17篇 |
2008年 | 25篇 |
2007年 | 32篇 |
2006年 | 38篇 |
2005年 | 19篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 14篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1974年 | 1篇 |
1972年 | 2篇 |
1971年 | 2篇 |
排序方式: 共有515条查询结果,搜索用时 31 毫秒
1.
Comparison of two urinary antigen tests for establishment of pneumococcal etiology of adult community-acquired pneumonia 总被引:4,自引:0,他引:4
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Strålin K Kaltoft MS Konradsen HB Olcén P Holmberg H 《Journal of clinical microbiology》2004,42(8):3620-3625
The Binax NOW immunochromatographic test (ICT) detecting the pneumococcal C polysaccharide and a serotype-specific latex agglutination (LA) test detecting 23 pneumococcal capsular antigens were evaluated for establishing pneumococcal etiology in community-acquired pneumonia (CAP) by use of nonconcentrated urine. ICT was considered to be strongly positive for result lines at least as intense as the control line and weakly positive for less intense result lines. When 215 adult CAP patients were tested, strong ICT, weak ICT, and LA positivity were found in 28, 24, and 16 patients, respectively; of these patients, 13 (46%), 6 (25%), and 13 (81%), respectively, had pneumococcal bacteremia and 27 (96%), 17 (71%), and 15 (94%), respectively, had Streptococcus pneumoniae isolated from blood, sputum, and/or nasopharynx. Among 108 controls tested, 2 (1.9%) were weakly ICT positive. When weak positivity was considered negative, the sensitivity of ICT decreased from 79% (19 of 24) to 54% (13 of 24), while the specificity increased from 83% (158 of 191) to 92% (176 of 191); no controls were false positive. The sensitivity and specificity of LA were 54% (13 of 24) and 98% (188 of 191), respectively. Eight of nine LA serotypes corresponded to culture serotypes. In conclusion, using nonconcentrated urine and dividing ICT-positive results into strongly and weakly positive results is a suitable way of performing ICT. While weak ICT positivity should be interpreted with caution, strong ICT positivity and LA positivity should be considered supportive of pneumococcal etiology in adult CAP. As such, these assays might have implications for antibiotic use in CAP. LA has promising potential for pneumococcal serotyping, although further evaluation is required. 相似文献
2.
Guido Lammering Theodore H Hewit Mathew Holmes Kristoffer Valerie William Hawkins Peck-Sun Lin Ross B Mikkelsen Rupert K Schmidt-Ullrich 《Clinical cancer research》2004,10(19):6732-6743
PURPOSE: The commonly expressed variant epidermal growth factor receptor (EGFR), the type III EGFR variant (EGFRvIII), functions as an oncoprotein promoting neoplastic transformation and tumorigenicity. The role of EGFRvIII in cellular responses to genotoxic stress, such as ionizing radiation, is only minimally defined. Thus, we have investigated EGFRvIII as a potential modulator of cellular radiation responses and explored the feasibility of adenovirus (Ad)-mediated expression of dominant-negative EGFR-CD533 as a gene therapeutic approach for inhibiting EGFRvIII function in vitro and in vivo. EXPERIMENTAL DESIGN AND RESULTS: EGFR-CD533 and EGFRvIII were expressed in vitro and in vivo in malignant U-373 MG glioma cells through transduction with an Ad vector, Ad-EGFR-CD533 and Ad-EGFRvIII, respectively. In vivo studies defined the importance of EGFRvIII as a modulator of radiation responses, demonstrating a 2.6-fold activation of EGFRvIII in U-373 malignant glioma tumors. Concomitant expression of EGFR-CD533 inhibited the radiation-induced activation of EGFRvIII in vitro and completely abolished the enhanced clonogenic survival conferred by EGFRvIII. The ability of EGFR-CD533 to inhibit EGFRvIII function was further confirmed in vivo through complete inhibition of EGFRvIII-mediated increased tumorigenicity and radiation-induced activation of EGFRvIII. Growth delay assays with U-373 xenograft tumors demonstrated that the expression of EGFR-CD533 significantly enhanced radiosensitivity of tumor cells under conditions of intrinsic and Ad-mediated EGFRvIII expression. CONCLUSIONS: We conclude that EGFRvIII confers significant radioresistance to tumor cells through enhanced cytoprotective responses, and we have demonstrated that dominant-negative EGFR-CD533 effectively inhibits EGFRvIII function. These data affirm the broad potential of EGFR-CD533 to radiosensitize human malignant glioma cells. 相似文献
3.
Anne Marie Asemissen Carmen Scheibenbogen Anne Letsch Kristoffer Hellstrand Fredrik Thorén Kurt Gehlsen Alexander Schmittel Eckhard Thiel Ulrich Keilholz 《Clinical cancer research》2005,11(1):290-297
PURPOSE: Preclinical investigations suggest that histamine dihydrochloride (HDC) protects T cells and natural killer cells from inhibition by monocyte-derived reactive oxygen metabolites and synergizes with interleukin (IL) 2 in inducing T-cell activation. Here, we investigate whether this mechanism is operational in patients with melanoma treated with HDC as an adjunct to IL-2. EXPERIMENTAL DESIGN: Melanoma patients having liver metastases were treated with IL-2 with or without HDC within a randomized, multicenter, phase III trial. The effect of HDC on type 1 and type 2 T-cell cytokine production was investigated in peripheral blood samples from 19 patients with the use of intracellular cytokine flow cytometry. Melanoma-specific T-cell responses were analyzed in eight HLA-A2-positive patients. RESULTS: Frequencies of CD3+ T cells producing IFN-gamma (type 1 T cells) in response to phorbol myristate acetate/ionomycin increased (median, 1.8-fold) in patients receiving IL-2 plus HDC but not in those receiving IL-2 alone (P < 0.01 for comparison between arms). In contrast, the number of IL-13-producing type 2 T cells that increased in patients after treatment with IL-2 was not modulated by HDC. Melanoma- and tyrosinase-specific IFN-gamma and IL-13-producing T cells were detected in two of four HLA-A2-positive patients with melanoma following treatment with HDC + IL-2. CONCLUSIONS: Treatment of patients with stage IV melanoma with HDC in combination with IL-2 increases type 1 T-cell responses and may promote induction of melanoma-specific T cells. These effects are of relevance for tumor immunotherapy and provide a potential mechanism for the clinical efficacy of HDC added to IL-2. 相似文献
4.
Vidar Andersen Helene Pedersen Marius Steiro Fimland Matthew Shaw Tom Erik Jorung Solstad Nicolay Stien Kristoffer Toldnes Cumming Atle Hole Saeterbakken 《Journal of Sports Science and Medicine》2021,20(2):181
The aim of the study was to compare neuromuscular activation in the gluteus maximus, the biceps femoris and the erector spinae from the Romanian deadlift, the 45-degree Roman chair back extension and the seated machine back extension. Fifteen resistance-trained females performed three repetitions with 6-RM loading in all exercises in a randomized and counterbalanced order. The activation in the whole movement as well as its lower and upper parts were analyzed. The results showed that the Romanian deadlift and the Roman chair back extension activated the gluteus maximus more than the seated machine back extension (94-140%, p < 0.01). For the biceps femoris the Roman chair elicited higher activation compared to both the Romanian deadlift and the seated machine back extension (71-174%). Further, the Romanian deadlift activated the biceps femoris more compared to the seated machine back extension (61%, p < 0.01). The analyses of the different parts of the movement showed that the Roman chair produced higher levels of activation in the upper part for both the gluteus maximus and the biceps femoris, compared to the other exercises. There were no differences in activation of the erector spinae between the three exercises (p = 1.00). In conclusion, both the Roman deadlift and the Roman chair back extension would be preferable to the seated machine back extension in regards to gluteus maximus activation. The Roman chair was superior in activating the biceps femoris compared to the two other exercises. All three exercises are appropriate selections for activating the lower back muscles. For overall lower limb activation, the Roman chair was the best exercise.Key points
- In general, the Roman chair back extension lead to superior muscle activation compared to the Romanian deadlift and the seated machine back extension
- The seated machine back extension showed the lowest gluteus and hamstring activation
- All three exercises are appropriate selections for activating the lower back muscles
- The differences in muscle activation are most likely caused by biomechanical differences.
5.
Andreas Hjelm Brandt Kristoffer Lindskov Hansen Caroline Ewertsen Simon Holbek Jacob Bjerring Olesen Ramin Moshavegh Carsten Thomsen Jørgen Arendt Jensen Michael Bachmann Nielsen 《Ultrasound in medicine & biology》2018,44(8):1751-1761
Magnetic resonance phase contrast angiography (MRA) is the gold standard for blood flow evaluation. Spectral Doppler ultrasound (SDU) is the first clinical choice, although the method is angle dependent. Vector flow imaging (VFI) is an angle-independent ultrasound method. The aim of the study was to compare VFI- and SDU-estimated peak systolic velocities (PSV) of the common carotid artery (CCA) with PSV obtained by MRA. Furthermore, intra- and inter-observer agreement was determined. MRA estimates were significantly different from SDU estimates (left CCA: p?<?0.001, right CCA: p?<?0.001), but not from VFI estimates (left CCA: p?=?0.28, right CCA: p?=?0.18). VFI measured lower PSV in both CCAs compared with SDU (p?<?0.001) with improved precision (VFI: left: 24%, right: 18%; SDU: left 38%, right: 23%). Intra- and inter-observer agreement was almost perfect for VFI and SDU (inter-observer correlation coefficient: VFI 0.88, SDU 0.91; intra-observer correlation coefficient: VFI 0.96, SDU 0.97). VFI is more accurate than SDU in evaluating PSV compared with MRA. 相似文献
6.
Kristoffer S. Berlin PhD W. Hobart Davies Alan H. Silverman Douglas W. Woods Elizabeth A. Fischer Colin D. Rudolph 《Children's Health Care》2013,42(2):142-156
A caregiver questionnaire that assesses mealtime problems in children aged 2 to 6 years old was developed. Community caregivers (n = 712) completed the Mealtime Behavior Questionnaire (MBQ) and measures of child behavior and family mealtime behaviors and environment. Exploratory and confirmatory factor analyses revealed and validated the MBQ's 4 subscales (food refusal/avoidance; food manipulation; mealtime aggression/distress; and choking/, gagging/vomiting). Mealtime problems occurred from “sometimes” to “always” for 1% to 61% of the sample. The MBQ demonstrated excellent to fair internal consistencies, and preliminary evidence for validity was found. 相似文献
7.
Kristoffer Jarlov Jensen Victor Raúl Gómez Román Sanne Skov Jensen Christian Leo-Hansen Ingrid Karlsson Terese Lea Katzenstein Candida Medina Rodrigues Sanne Jespersen Christoph Mikkel Janitzek David da Silva Té Peter Hayes Anders Fomsgaard 《Clinical and Vaccine Immunology : CVI》2012,19(12):1999-2001
8.
Simon Holbek Kristoffer Lindskov Hansen Hamed Bouzari Caroline Ewertsen Matthias Bo Stuart Carsten Thomsen Michael Bachmann Nielsen Jørgen Arendt Jensen 《Ultrasound in medicine & biology》2017,43(10):2213-2220
Ultrasound (US) examination of the common carotid artery was compared with a through-plane magnetic resonance imaging (MRI) sequence to validate a recently proposed technique for 3-D US vector flow imaging. Data from the first volunteer examined were used as the training set, before volume flow and peak velocities were calculated for the remaining eight volunteers. Peak systolic velocities (PSVs) and volume flow obtained with 3-D US were, on average, 34% higher and 24% lower than those obtained with MRI, respectively. A high correlation was observed for PSV (r = 0.79), whereas a lower correlation was observed for volume flow (r = 0.43). The overall standard deviations were ±5.7% and ±5.7% for volume flow and PSV with 3-D US, compared with ±2.7% and ±3.2% for MRI. Finally, the data were re-processed with a change in the parameter settings for the echo-canceling filter to investigate its influence on overall performance. PSV was less affected by the re-processing, whereas the difference in volume flow between 3-D vector flow imaging and MRI was reduced to ?9%, and with an improved overall standard deviation of ±4.7%. The results illustrate the feasibility of using 3-D US for precise and angle-independent volume flow and PSV estimation in vivo. 相似文献
9.
Hansen Mads Kingo Guldberg Kjærgaard Kristoffer Eriksen Lotte Lindgreen Grønkjær Lea Ladegaard Mikkelsen Anne Catrine Daugaard Sandahl Thomas Damgaard Vilstrup Hendrik Thomsen Karen Louise Lauridsen Mette Munk Enok 《Metabolic brain disease》2022,37(3):589-605
Metabolic Brain Disease - Hepatic encephalopathy (HE) is cerebral dysfunction caused by liver failure and inflicts 30-40% of patients with liver cirrhosis during their disease course. Clinically... 相似文献
10.
Neutrophils are thought to orchestrate myocardial remodeling during the early progression to cardiac failure through the release of reactive oxygen species, antimicrobial peptides, and proteases. Although neutrophil activation may be beneficial at early stages of disease, excessive neutrophil infiltration can induce cardiomyocyte death and tissue damage. The neutrophil-derived serine protease cathepsin G (Cat.G) has been shown to induce neonatal rat cardiomyocyte detachment and apoptosis by anoikis. However, the involved signaling mechanisms for Cat.G are not well understood. This study identifies epidermal growth factor receptor (EGFR) transactivation as a mechanism whereby Cat.G induces signaling in cardiomyocytes. Cat.G induced a rapid and transient increase in EGFR tyrosine phosphorylation, and inhibition of EGFR kinase activity, either with AG1478 or by expression of kinase inactive EGFR mutants (EGFR-CD533), markedly attenuated EGFR downstream signaling and myocyte anoikis induced by Cat.G. Consistent with this effect of EGFR, high level expression of wild-type EGFR was sufficient to promote myocyte apoptosis. We also found that matrix metalloproteinase-dependent membrane shedding of heparin-binding EGF was involved in Cat.G signaling and that membrane type 1 matrix metalloproteinase activation may constitute a potential target that entails matrix metalloproteinase activation induced by Cat.G. The paradoxical proapoptotic effect of EGFR appeared to be dependent on protein tyrosine phosphatase SHP2 (Src homology domain 2-containing tyrosine phosphatase 2) activation and focal adhesion kinase downregulation. These results show that Cat.G-induced cardiomyocyte apoptosis involves an increase in EGFR-dependent activation of SHP2 that promotes focal adhesion kinase dephosphorylation and subsequent cardiomyocyte anoikis. 相似文献