208 research outputs found
Generating artificial homologous proteins according to the representative family character in molecular mechanics properties – an attempt in validating an underlying rule of protein evolution
AbstractThe molecular mechanics property is the foundation of many characters of proteins. Based on intramolecular hydrophobic force network, the representative family character underlying a protein’s mechanics property is described by a simple two-letter scheme. The tendency of a sequence to become a member of a protein family is scored according to this mathematical representation. Remote homologs of the WW-domain family could be easily designed using such a mechanistic signature of protein homology. Experimental validation showed that nearly all artificial homologs have the representative folding and bioactivity of their assigned family. Since the molecular mechanics property is the only consideration in this study, the results indicate its possible role in the generation of new members of a protein family during evolution
Dynamic stability of electrostatic torsional actuators with van der Waals effect
AbstractThe influence of van der Waals (vdW) force on the stability of electrostatic torsional nano-electro-mechanical systems (NEMS) actuators is analyzed in the paper. The dependence of the critical tilting angle and voltage is investigated on the sizes of structure with the consideration of vdW effects. The pull-in phenomenon without the electrostatic torque is studied, and a critical pull-in gap is derived. A dimensionless equation of motion is presented, and the qualitative analysis of it shows that the equilibrium points of the corresponding autonomous system include center points, stable focus points, and unstable saddle points. The Hopf bifurcation points and fork bifurcation points also exist in the system. The phase portraits connecting these equilibrium points exhibit periodic orbits, heteroclinic orbits, as well as homoclinic orbits
Topography-induced symmetry transition of droplets on quasi-periodically patterned surfaces
Quasi-periodic structures of quasicrystals yield novel effects in diverse
systems. However, there is little investigation on employing quasi-periodic
structures in the morphology control. Here, we show the use of quasi-periodic
surface structures in controlling the transition of liquid droplets. Although
surface structures seem random-like, we find that on these surfaces, droplets
spread to well-defined 5-fold symmetric shapes and the symmetry of droplet
shapes spontaneously restore during spreading, hitherto unreported in the
morphology control of droplets. To obtain physical insights into these symmetry
transitions, we conduct energy analysis and perform systematic experiments by
varying properties of both liquid droplet and patterned surface. The results
show the dominant factors in determining droplet shapes to be surface
topography and the self-similarity of the surface structure. Our findings
significantly advance the control capability of the droplet morphology. Such a
quasi-periodic patterning strategy can offer a new method to achieve complex
patterns
"A continuous awaking movement". Note sul choreocinema di Maya Deren
Maya Deren ha prodotto tra gli anni quaranta e la metà degli anni cinquanta del secolo scorso un cinema visionario in cui la danza e i danzatori diventano i protagonisti della trasfigurazione del reale in arte, del viaggio dal mondo visibile a quello invisibile delle forme sottili dell’inconscio e della mente. Il saggio si incentra sul ciclo di film di Maya Deren che John Martin, critico di danza del New York Times e teorico di punta della modern dance, definì come choreocinema: >, soffermandosi principalmente su A Study in Choreography for Camera del 1945 che Deren creò collaborando con il danzatore afro-americano Talley Beatty
Meta-Analysis of Randomized Controlled Trials on the Efficacy and Safety of Donepezil, Galantamine, Rivastigmine, and Memantine for the Treatment of Alzheimer’s Disease
To study the impact of donepezil, rivastigmine, galantamine, and memantine on cognitive, functional, behavioral, global changes and adverse effects in patients with mild, moderate and severe Alzheimer’s disease (AD), we screened the literature published before September 2017 in the Pubmed, Embase, Cochrane library and Web of Science Electronic databases according to the inclusion criteria. Thirty-six studies were finally determined from 1560 preliminary screened articles. The AD Assessment Scale-cognitive Subscale (ADAS-cog), AD Cooperative Study-Activities of Daily Living (ADCS-ADL), Neuropsychiatric Inventory (NPI), and Clinician’s Interview-Based Impression of Change Plus Caregiver Input scale (CIBIC+) were used as valid endpoints. Of the 36 trials included, meta-analyses of these placebo-control trials showed that there were significant differences between the donepezil, rivastigmine and placebo groups using ADAS-cog, ADCS-ADL, and CIBIC+. Meta-analyses of these placebo-controlled trials showed that there were significant differences between the galantamine and placebo groups using ADAS-cog, ADCS-ADL, NPI, and CIBIC+. These observations suggest that memantine is beneficial for stabilizing or slowing the decline in ADAS-cog and ADCS-ADL19 changes in AD patients. However, there was no significant effect according to the ADCS-ADL23, NPI, and CIBIC+ tests, which indicated that memantine treatment has no significant effect on these cognitive aspects of AD patients. Different effects of donepezil, rivastigmine, galantamine, or memantine on AD were found in this study. According to the results, we conclude that galantamine is effective in treating all aspects of AD and is the first choice for the treatment of AD. However, due to limited data, we should consider additional data to obtain more stable results
A simulation study on the measurement of D0-D0bar mixing parameter y at BES-III
We established a method on measuring the \dzdzb mixing parameter for
BESIII experiment at the BEPCII collider. In this method, the doubly
tagged events, with one decays to
CP-eigenstates and the other decays semileptonically, are used to
reconstruct the signals. Since this analysis requires good separation,
a likelihood approach, which combines the , time of flight and the
electromagnetic shower detectors information, is used for particle
identification. We estimate the sensitivity of the measurement of to be
0.007 based on a fully simulated MC sample.Comment: 6 pages, 7 figure
Serum ASGR2 level: an efficacy biomarker for balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension
BackgroundThis study aimed to employ plasma proteomics to investigate the molecular changes, pathway alterations, and potential novel biochemical markers associated with balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH).MethodsPre- and post-BPA plasma samples from five CTEPH patients in the PRACTICE study were analyzed to identify differentially expressed proteins. Proteomic and bioinformatics analyses were conducted, and the identified proteins were further validated using ELISA assays in a separate cohort of the same study. Correlation and multivariate regression analyses were performed to investigate the associations between these differentially expressed proteins and clinical parameters.ResultsSignificantly higher serum levels of asialoglycoprotein receptor 2 (ASGR2) were detected in 5 CTEPH patients compared to those in healthy individuals but decreased significantly after successful BPA procedures. The decrease in serum levels of ASGR2 after the completion of BPA procedures was further validated in a separate cohort of 48 patients with CTEPH [0.70 (0.51, 1.11) ng/mL vs. 0.38 (0.27, 0.59) ng/mL, P < 0.001]. Significant associations were found between the pre-BPA ASGR2 level and clinical parameters, including neutrophil percentage (R = 0.285, P < 0.05), platelet (PLT) count (R = 0.386, P < 0.05), and high-density lipoprotein cholesterol (HDL-C) before BPA (R = -0.285, P < 0.05). Significant associations were detected between post-BPA serum ASGR2 levels and lymphocyte percentage (LYM%) (R = 0.306, P < 0.05), neutrophil-to-lymphocyte ratio (R = -0.294, P < 0.05), and pulmonary vascular resistance after BPA (R = -0.35, P < 0.05). Multivariate stepwise regression analysis revealed that pre-BPA ASGR2 levels were associated with HDL-C and PLT count (both P < 0.001), while post-BPA ASGR2 levels were associated with LYM% (P < 0.05).ConclusionSerum levels of ASGR2 may be a biomarker for the effectiveness of BPA treatment in CTEPH patients. The pre-BPA serum level of ASGR2 in CTEPH patients was associated with HDL-C and the PLT count. The post-BPA serum level of ASGR2 was correlated with the LYM%, which may reflect aspects of immune and inflammatory status
Interactive effects of nutrients and salinity on zooplankton in subtropical plateau lakes with contrasting water depth
Both eutrophication and salinization are growing global environmental problems in freshwater ecosystems, threatening the water quality and various aquatic organisms. However, little is known about their interactive effects on theses stressors and the role of lake depth on these interactions. We used field surveys to compared zooplankton assemblages over four seasons in eight Yunnan Plateau lakes with different trophic states, salinization levels, and water depths. The results showed that: 1) the species number (S), density (DZoop), and biomass (BZoop) of zooplankton exhibited strong seasonal dynamics, being overall higher in the warm seasons. 2) Data collected over four seasons and summer data both revealed highly significant positive relationships of S, DZoop, and BZoop with total nitrogen (TN), total phosphorus (TP), and phytoplankton chlorophyll a (Chl a). 3) S, DZoop, and BZoop displayed a unimodal relationship with salinity, peaking at 400–1000 μS/cm (conductivity, to reflect salinity). 4) The two large-sized taxa (cladocerans and copepods) generally increased at low-moderate levels of TN, TP, Chl a, and Cond and was constant or decreased at high levels. The average body mass (biomass/density) of crustaceans decreased with increasing TN, TP, Chl a, and conductivity. Our findings indicate that zooplankton may be more vulnerable in deep lakes than in shallow lakes when exposed to conductivity stress even under mesotrophic conditions, and the overall decrease in size in zooplankton assemblages under the combined stress of eutrophication and salinization may result in a lowered grazing effect on phytoplankton
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