A proteomic analysis of Psychrobacter articus 273-4 adaptation to low temperature and salinity using a 2-D liquid mapping approach

Psychrobacter 273-4 was isolated from a 20 000–40 000–year-old Siberian permafrost core, which is characterized by low temperature, low water activity, and high salinity. To explore how 273-4 survives in the permafrost environment, proteins in four 273-4 samples cultured at 4 and 22°C in media with and without 5% 14sodium chloride were profiled and comparatively studied using 2-D HPLC and MS. The method used herein involved fractionation via a pH gradient using chromatofocusing followed by nonporous silica 14(NPS) RP-HPLC and on-line electrospray mass mapping. It was observed that 33 14proteins were involved in the adaptation to low temperature in the cells grown in the nonsaline media while there were only 14 proteins involved in the saline media. There were 45 14proteins observed differentially expressed in response to salt at 22°C while there were 22 14proteins at 4°C. In addition, 5% 14NaCl and 4°C showed a combination effect on protein expression. A total of 56 14proteins involved in the adaptation to low temperature and salt were identified using MS and database searching. The differentially expressed proteins were classified into different functional categories where the response of the regulation system to stress appears to be very elaborate. The evidence shows that the adaptation of 273-4 is based primarily on the control of translation and transcription, the synthesis of proteins (chaperones) to facilitate RNA and protein folding, and the regulation of metabolic pathways.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55939/1/467_ftp.pd

Attitudes of developing world physicians to where medical research is performed and reported

Background: Little is known about the influence of the site of research or publication on the impact of the research findings on clinical practice, particularly in developing countries. The International Clinical Epidemiology Network (INCLEN) is dedicated to improving the quality of health research in the Developing World through institutional capacity building for evidence based medicine, and provided the opportunity to examine the likely impact of research location and journal location on physicians\u27 practice in a number of the participating countries. Methods: Physicians from secondary and tertiary hospitals in six cities located in China, Thailand, India, Egypt and Kenya were enrolled in a cross-sectional questionnaire survey. The primary outcome measures were scores on a Likert scale reflecting stated likelihood of changing clinical practice depending on the source of the research or its publication. Results: Overall, local research and publications were most likely to effect change in clinical practice, followed by North American, European and regional research/publications respectively, although there were significant variations between countries. The impact of local and regional research would be greater if the perceived research quality improved in those settings. Conclusion: Conducting high quality local research is likely to be an effective way of getting research findings into practice in developing countries

Effect of Protamex Hydrolysis on Foaming Properties and Structural Properties of Corn Glutelin

The effects of different durations of hydrolysis with Protemex on the foaming properties, surface tension, physicochemical properties and static rheological properties of corn glutelin were determined. The results showed that the solubility and foaming properties of corn glutelin were significantly improved by Protamex hydrolysis. The foaming capacity of the 120 min hydrolysate was highest, which was 2.8 times higher than that of corn glutelin, and its foam stability was also good. The hydrolysate had the lowest surface tension and the highest apparent viscosity. The microscopic morphology of the foam formed was fine and uniform, with a thick protein film. With the prolongation of hydrolysis time, the average particle size of corn glutelin hydrolysates decreased continuously, the endogenous fluorescence intensity and surface hydrophobicity increased gradually, while the surface net charge decreased first and then increased. The results of Raman spectroscopy showed that after appropriate hydrolysis, the α-helix content decreased, and the random coil and β-angle contents increased; the peak intensity ratio of tyrosine residues (I850/I830) increased, and the peak intensity of tryptophan residues (I760) decreased. Nevertheless, the β-folding content changed little. Long-time hydrolysis significantly increased the content of random coil and decreased the peak intensity ratio of tyrosine residues (I850/I830). Therefore, restricted hydrolysis can change the structure and interface properties of corn glutelin, improve its foam properties, and consequently increase the potential utilization rate of corn gluten meal in the food field

Dual antiplatelet therapy for ischemic stroke with intracranial arterial stenosis: a systematic review and meta-analysis

BackgroundThe safety and efficacy of dual antiplatelet therapy (DAPT) in ischemic stroke patients with intracranial artery stenosis (ICAS) remain contentious.AimsThis study evaluates DAPT’s effectiveness and safety for these patients.MethodsThis review was reported following PRISMA 2020 guidelines. A comprehensive search was conducted in PubMed, Embase, Cochrane Library, ClinicalTrials.gov, CNKI, WanFang, VIP, and SinoMed up to June 20, 2023, for randomized controlled trials comparing efficacy and safety of DAPT against single antiplatelet therapy (SAPT) in ischemic stroke patients with ICAS. The primary outcome was a composite of ischemic and bleeding events. Secondary outcomes included stroke (cerebral infarction and hemorrhage), ischemic events, and cerebral infarction. Safety outcomes assessed were bleeding events, cerebral hemorrhage, and mortality. Risk ratios (RRs) with 95% confidence intervals (CIs) were synthesized using Review Manager 5.4.ResultsAnalysis of 21 randomized controlled trials involving 3,591 patients revealed that DAPT significantly lowered the rate of ischemic and bleeding events (RR = 0.52; 95% CI: 0.46–0.59, p < 0.001) and recurrent stroke (RR = 0.37; 95% CI: 0.30–0.44, p < 0.001) compared to SAPT. There was no significant increase in bleeding events (RR = 1.34; 95% CI: 0.97–1.85, p = 0.07) or cerebral hemorrhage (RR = 0.47; 95% CI: 0.17–1.31, p = 0.15).ConclusionDAPT proveed to be effective and safe for ischemic stroke patients with ICAS and significantly reduced stroke and the composite endpoint of ischemic and bleeding events without elevating bleeding risks

Attitudes of developing world physicians to where medical research is performed and reported

Background Little is known about the influence of the site of research or publication on the impact of the research findings on clinical practice, particularly in developing countries. The International Clinical Epidemiology Network (INCLEN) is dedicated to improving the quality of health research in the Developing World through institutional capacity building for evidence based medicine, and provided the opportunity to examine the likely impact of research location and journal location on physicians' practice in a number of the participating countries. Methods Physicians from secondary and tertiary hospitals in six cities located in China, Thailand, India, Egypt and Kenya were enrolled in a cross-sectional questionnaire survey. The primary outcome measures were scores on a Likert scale reflecting stated likelihood of changing clinical practice depending on the source of the research or its publication. Results Overall, local research and publications were most likely to effect change in clinical practice, followed by North American, European and regional research/publications respectively, although there were significant variations between countries. The impact of local and regional research would be greater if the perceived research quality improved in those settings. Conclusion Conducting high quality local research is likely to be an effective way of getting research findings into practice in developing countries

Proteomic methods development and analysis of proteomic response of <italic>Psychrobacter 273-4</italic> and <italic>Escherichia coli</italic> in extreme environments.

This thesis focuses on proteomic methods development, analysis of proteomic response of Psychrobacter 273-4 and Escherichia coli in extreme environments and differential proteomic analysis of normal and O157:H7 Escherichia coli using two-dimensional HPLC combined with mass spectrometry. On-probe digestion was developed to perform protein digestion in 5 minutes with 5-18% improvement of protein sequence coverage. It was further integrated with monolithic column HPLC and off-line MALDI to identify proteins in breast cancer cells using only 120ng of proteins. Li-CHCA provides homogeneous spots on the MALDI plate when used with CHCA as a matrix. Lithium ions can not only be selectively attached to certain amino acid residues also selectively regulate the relative abundance of peaks in the MALDI spectrum, which allows more peptides detected in mass spectrometry analysis in certain fractions of E. coli. Four lines of Psychrobacter 273-4 cultured at 22&deg;C and 4&deg;C in the media with or without 5% sodium chloride were comparatively studied. Fifty-six proteins associated with given extreme environment, including five environment specific proteins, were identified. Combination effect of salinity and 4&deg;C on protein expression has been observed. The mechanism of the adaptation to low temperature and salinity relies on the control of translation and transcription, the synthesis of proteins (chaperones) to facilitate RNA and protein folding, and the regulation of metabolic pathways. Six lines of E. coli propagated for 2,000 generations at 20&deg;C were compared with their ancestors to provide the proteomic basis of evolutionary adaptation to low temperature. The differences of protein profiles between ancestor and descendants varied significantly with the origin and batch number of samples even they were developed from the same ancestor. This result suggests that the adaptation of E. coli to 20&deg;C is achieved through multiple pathways. Analysis of differential protein expression between one normal and twoO157:H7 E. coli reveals that no significant differential protein expression is exhibited between the two O157:H7 strains examined over a pH range of 4.0-7.0, and O157:H7 could be distinguished from nonvirulent E. coli using a 2D UV map pattern as a fingerprint. Several potential markers are identified for detection and treatment of O157:H7 infection.Ph.D.Analytical chemistryBiological SciencesMicrobiologyPure SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/125787/2/3208588.pd

GPU-acceleration 3D rotated-staggered-grid solutions to microseismic anisotropic wave equation with moment tensor implementation

To improve the accuracy of microseismic inversion, seismic anisotropy and moment tensor source should be carefully considered in the forward modelling stage. In this study, 3D microseismic anisotropy wave forward modelling with a moment tensor source was proposed. The modelling was carried out based on a rotated-staggered-grid (RSG) scheme. In contrast to staggered-grids, the RSG scheme defines the velocity components and densities at the same grid, as do the stress components and elastic parameters. Therefore, the elastic moduli do not need to be interpolated. In addition, the detailed formulation and implementation of moment-tensor source loaded on the RSG was presented by equating the source to the stress increments. Meanwhile, the RSG-based 3D wave equation forward modelling was performed in parallel using compute unified device architecture (CUDA) programming on a graphics processing unit (GPU) to improve its efficiency. Numerical simulations including homogeneous and anisotropic models were carried out using the method proposed in this paper, and compared with other methods to prove the reliability of this method. Furthermore, the high efficiency of the proposed approach was evaluated. The results show that the computational efficiency of proposed method can be improved by about two orders of magnitude compared with traditional central processing unit (CPU) computing methods. It could not only help the analysis of microseismic full wavefield records, but also provide support for passive source inversion, including location and focal mechanism inversion, and velocities inversion

Adsorption of Lead Ion from Wastewater Using Non-Crystal Hydrated Calcium Silicate Gel

In order to obtain low-cost and excellent adsorption materials, this paper used calcium acetate and water glass as raw materials to synthesis hydrated calcium silicate gel by precipitation method. The performance and structure of hydrated calcium silicate gel were systematically studied by X-ray photoelectron spectroscopy, fourier transform infrared spectroscopy, specific surface area analyzer and scanning electron microscope. Studies have shown that, non-crystal hydrated calcium silicate gel (CSH) were successfully prepared, and the removal rate of lead ion using CSH reached more than 90%. The adsorption process is consistent with the pseudo-second-order kinetic model and Langmuir adsorption isotherm model, and the limit adsorption capacity reaches 263.17 mg·g−1. The acid treatment experiment proved that the adsorption capacity of lead ion using CSH was satisfactory, and the adsorption rate remained at >60% after 5 cycles. The research may provide a low-cost, high-efficiency and high stability adsorbent