10,572 research outputs found
Robust fermionic-mode entanglement of a nanoelectronic system in non-Markovian environments
A maximal steady-state fermionic entanglement of a nanoelectronic system is
generated in finite temperature non-Markovian environments. The fermionic
entanglement dynamics is presented by connecting the exact solution of the
system with an appropriate definition of fermionic entanglement. We prove that
the two understandings of the dissipationless non-Markovian dynamics, namely
the bound state and the modified Laplace transformation are completely
equivalent. For comparison, the steady-state entanglement is also studied in
the wide-band limit and Born-Markovian approximation. When the environments
have a finite band structure, we find that the system presents various kinds of
relaxation processes. The final states can be: thermal or thermal-like states,
quantum memory states and oscillating quantum memory states. Our study provide
an analytical way to explore the non-Markovian entanglement dynamics of
identical fermions in a realistic setting, i.e., finite temperature reservoirs
with a cutoff spectrum
Electroneutrality Breakdown and Specific Ion Effects in Nanoconfined Aqueous Electrolytes Observed by NMR
Ion distribution in aqueous electrolytes near the interface plays critical
roles in electrochemical, biological and colloidal systems and is expected to
be particularly significant inside nanoconfined regions. Electroneutrality of
the total charge inside nanoconfined regions is commonly assumed a priori in
solving ion distribution of aqueous electrolytes nanoconfined by uncharged
hydrophobic surfaces with no direct experimental validation. Here, we use a
quantitative nuclear magnetic resonance approach to investigate the properties
of aqueous electrolytes nanoconfined in graphitic-like nanoporous carbon.
Substantial electroneutrality breakdown in nanoconfined regions and very
asymmetric responses of cations and anions to the charging of nanoconfining
surfaces are observed. The electroneutrality breakdown is shown to depend
strongly on the propensity of anions toward the water-carbon interface and such
ion-specific response follows generally the anion ranking of the Hofmeister
series. The experimental observations are further supported by numerical
evaluation using the generalized Poisson-Boltzmann equationComment: 26 pages, 3 figure
Media coverage of stand your ground laws deters crime in some cities, but not in others
So-called ‘stand your ground laws’ – which give people the right to use deadly force to defend themselves – have now been in place for a decade. In new research which uses a Texas shooting incident as a case study, Ling Ren, Yan Zhang, and Jihong “Solomon” Zhao examine whether or not the publicity over shooting incidents where the law is invoked helps to deter crime – specifically residential and business burglaries. They find that such media coverage of high-profile incidents does have a deterrent effect in some nearby cities, but not in others
Intramolecular Torque, an Indicator of the Internal Rotation Direction of Rotor Molecules and Similar Systems
Torque is ubiquitous in many molecular systems, including collisions,
chemical reactions, vibrations, electronic excitations and especially rotor
molecules. We present a straightforward theoretical method based on forces
acting on atoms and obtained from atomistic quantum mechanics calculations, to
quickly and qualitatively determine whether a molecule or sub-unit thereof has
a tendency to rotation and, if so, around which axis and in which sense:
clockwise or counterclockwise. The method also indicates which atoms, if any,
are predominant in causing the rotation. Our computational approach can in
general efficiently provide insights into the rotational ability of many
molecules and help to theoretically screen or modify them in advance of
experiments or before analyzing their rotational behavior in more detail with
more extensive computations guided by the results from the torque approach. As
an example, we demonstrate the effectiveness of the approach using a specific
light-driven molecular rotary motor which was successfully synthesized and
analyzed in prior experiments and simulations.Comment: 11 pages, 4 figures, 1 SI fil
Progressive decay of Ca2+ homeostasis in the development of diabetic cardiomyopathy
BACKGROUND: Cardiac dysfunction in diabetic cardiomyopathy may be associated with abnormal Ca(2+) homeostasis. This study investigated the effects of alterations in Ca(2+) homeostasis and sarcoplasmic reticulum Ca(2+)-associated proteins on cardiac function in the development of diabetic cardiomyopathy. METHODS: Sprague–Dawley rats were divided into 4 groups (n = 12, each): a control group, and streptozotocin-induced rat models of diabetes groups, examined after 4, 8, or 12 weeks. Evaluations on cardiac structure and function were performed by echocardiography and hemodynamic examinations, respectively. Cardiomyocytes were isolated and spontaneous Ca(2+) spark images were formed by introducing fluorescent dye Fluo-4 and obtained with confocal scanning microscopy. Expressions of Ca(2+)-associated proteins were assessed by Western blotting. RESULTS: Echocardiography and hemodynamic measurements revealed that cardiac dysfunction is associated with the progression of diabetes, which also correlated with a gradual but significant decline in Ca(2+) spark frequency (in the 4-, 8- and 12-week diabetic groups). However, Ca(2+) spark decay time constants increased significantly, relative to the control group. Expressions of ryanodine receptor 2 (RyR2), sarcoplasmic reticulum Ca(2+)-2ATPase (SERCA) and Na(+)/Ca(2+) exchanger (NCX1) were decreased, together with quantitative alterations in Ca(2+)regulatory proteins, FKBP12.6 and phospholamban progressively and respectively in the diabetic rats. CONCLUSIONS: Ca(2+) sparks exhibited a time-dependent decay with progression of diabetic cardiomyopathy, which may partly contribute to cardiac dysfunction. This abnormality may be attributable to alterations in the expressions of some Ca(2+)-associated proteins
The role of globular heads of the C1q receptor in HPV 16 E2-induced human cervical squamous carcinoma cell apoptosis is associated with p38 MAPK/JNK activation
BACKGROUND Human papillomavirus type 16 (HPV 16) E2 protein is a multifunctional DNA-binding protein. HPV 16 E2 regulates many biological responses, including DNA replication, gene expression, and apoptosis. The purpose of this study was to investigate the relationship among the receptor for globular heads of the human C1q (gC1qR) gene expression, HPV 16 E2 transfection and apoptosis regulation in human cervical squamous carcinoma cells (C33a and SiHa). METHODS gC1qR expression was examined in C33a and SiHa cells using real-time PCR and Western blot analysis. Apoptosis of C33a and SiHa cells was assessed by flow cytometry. C33a and SiHa cell viability, migration and proliferation were detected using the water-soluble tetrazolium salt (WST-1) assay, a transwell assay and 3H-thymidine incorporation into DNA (3H-TdR), respectively. RESULTS C33a and SiHa cells that were transfected with a vector encoding HPV 16 E2 displayed significantly increased gC1qR gene expression and p38 mitogen-activated protein kinase (p38 MAPK)/c-jun N-terminal kinase (JNK) activation as well as up-regulation of cellular apoptosis, which was abrogated by the addition of gC1qR small interfering RNA (siRNA). Furthermore, the changes in C33a and SiHa cell viability, migration and proliferation that were observed upon HPV 16 E2 transfection were abrogated by SB203580 (a p38 MAPK inhibitor) or SP600125 (a JNK inhibitor) treatment. CONCLUSION These data support a mechanism whereby HPV 16 E2 induces apoptosis by silencing the gC1qR gene or inhibiting p38 MAPK/JNK signalling in cervical squamous cell carcinoma.This study was supported by grants from the National Natural Science Foundation of China (No. 81000251) and the Nanjing Medical Science and Technique Development Foundation
Subglottic secretion suction for preventing ventilator-associated pneumonia: an updated meta-analysis and trial sequential analysis
BACKGROUND: Potential benefits of subglottic secretion suction for preventing ventilator-associated pneumonia (VAP) are not fully understood. METHODS: We searched Cochrane Central, PubMed, and EMBASE up to March 2016 to identify randomized controlled trials (RCTs) that compared subglottic secretion suction versus non-subglottic secretion suction in adults with mechanical ventilation. Meta-analysis was conducted using Revman 5.3, trial sequential analysis (TSA) 0.9 and STATA 12.0. The primary outcome was incidence of VAP. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to evaluate the level of evidence. RESULTS: Twenty RCTs (N = 3544) were identified. Subglottic secretion suction was associated with reduction of VAP incidence in four high quality trials (relative risk (RR) 0.54, 95 % confidence interval (CI) 0.40–0.74; p < 0.00001) and in all trials (RR = 0.55, 95 % CI 0.48– 0.63; p < 0.00001). Sensitivity analyses did not show differences in the pooled results. Additionally, the results of the above-mentioned analyses were confirmed in TSA. GRADE level was high. Subglottic secretion suction significantly reduced incidence of early onset VAP, gram-positive or gram-negative bacteria causing VAP, and duration of mechanical ventilation. It delayed the time-to-onset of VAP. However, no significant differences in late onset VAP, intensive care unit (ICU) mortality, hospital mortality, or ICU length of stay were found. CONCLUSIONS: Subglottic secretion suction decreased VAP incidence and duration of mechanical ventilation and delayed VAP onset. However, subglottic secretion suction did not reduce mortality and length of ICU stay. Subglottic secretion suction is recommended for preventing VAP and for reducing ventilation length, especially in the population at high risk of early onset VAP. TRIAL REGISTRATION: A protocol of this meta-analysis has been registered on PROSPERO (registration number: CRD42015015715); registered on 5 January 2015. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13054-016-1527-7) contains supplementary material, which is available to authorized users
Scaling behavior of an artificial traffic model on scale-free networks
In this article, we investigate an artificial traffic model on scale-free
networks. Instead of using the routing strategy of the shortest path, a
generalized routing algorithm is introduced to improve the transportation
throughput, which is measured by the value of the critical point disjoining the
free-flow phase and the congested phase. By using the detrended fluctuation
analysis, we found that the traffic rate fluctuation near the critical point
exhibits the -type scaling in the power spectrum. The simulation results
agree very well with the empirical data, thus the present model may contribute
to the understanding of the underlying mechanism of network traffics.Comment: 6 pages, 5 figure
High remission and low relapse with prolonged intensive DMARD therapy in rheumatoid arthritis (PRINT): A multicenter randomized clinical trial
Objectives: To determine whether prolonged intensive disease-modifying antirheumatic drug (DMARD) treatment (PRINT) leads to high remission and low relapse rates in patients with severe rheumatoid arthritis (RA).
Methods: In this multicenter, randomized and parallel treatment trial, 346 patients with active RA (disease activity score (28 joints) [DAS28] (erythrocyte sedimentation rate [ESR]) > 5.1) were enrolled from 9 centers. In phase 1, patients received intensive treatment with methotrexate, leflunomide, and hydroxychloroquine, up to 36 weeks, until remission (DAS28 ≤ 2.6) or a low disease activity (2.6 < DAS28 ≤ 3.2) was achieved. In phase 2, patients achieving remission or low disease activity were followed up with randomization to 1 of 2 step-down protocols: leflunomide plus hydroxychloroquine combination or leflunomide monotherapy. The primary endpoints were good European League Against Rheumatism (EULAR) response (DAS28 (ESR) < 3.2 and a decrease of DAS28 by at least 1.2) during the intensive treatment and the disease state retention rate during step-down maintenance treatment. Predictors of a good EULAR response in the intensive treatment period and disease flare in the maintenance period were sought.
Results: A good EULAR response was achieved in 18.7%, 36.9%, and 54.1% of patients at 12, 24, and 36 weeks, respectively. By 36 weeks, 75.4% of patients achieved good and moderate EULAR responses. Compared with those achieving low disease activity and a high health assessment questionnaire (HAQ > 0.5), patients achieving remission (DAS28 ≤ 2.6) and low HAQ (≤ 0.5) had a significantly higher retention rate when tapering the DMARDs treatment (P = 0.046 and P = 0.01, respectively). There was no advantage on tapering to combination rather than monotherapy.
Conclusions: Remission was achieved in a proportion of patients with RA receiving prolonged intensive DMARD therapy. Low disease activity at the start of disease taper leads to less subsequent flares. Leflunomide is a good maintenance treatment as single treatment
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