Multi-Stage Tuberculosis Subunit Vaccine Candidate LT69 Provides High Protection against Mycobacterium tuberculosis Infection in Mice

Effective tuberculosis (TB) vaccine should target tubercle bacilli with various metabolic states and confer long-term protective immunity. In this study, we constructed a novel multi-stage TB subunit vaccine based on fusion protein ESAT6-Ag85B-MPT64(190-198)-Mtb8.4-HspX (LT69 for short) which combined early expressed antigens and latency-associated antigen. The fusion protein was mixed with an adjuvant being composed of N, N’-dimethyl-N, N’-dioctadecylammonium bromide (DDA) and polyriboinosinic polyribocytidylic acid (PolyI:C) to construct subunit vaccine, whose immunogenicity and protective ability were evaluated in C57BL/6 mice. The results showed that LT69 had strong immunogenicity and high protective effect against Mycobacterium tuberculosis (M. tuberculosis) H37Rv aerosol challenge. Low-dose (2 μg) of LT69 generated long-term immune memory responses and provided effective protection, which was even higher than traditional vaccine BCG did at 30 weeks post the last vaccination. In conclusion, multistage subunit vaccine LT69 showed high and long-term protection against M. tuberculosis infection in mice, whose effect could be enhanced by using a relative low dosage of antigen.National Major Science and Technology Projects (China) (2012ZX10003-008-006)National Natural Science Foundation (China) (31470895)National Natural Science Foundation (China) (81072499)China. Ministry of Education (Doctoral Fund 20120211110038

Biological Synthesis of Size-Controlled Cadmium Sulfide Nanoparticles Using ImmobilizedRhodobacter sphaeroides

Size-controlled cadmium sulfide nanoparticles were successfully synthesized by immobilizedRhodobacter sphaeroidesin the study. The dynamic process that Cd2+was transported from solution into cell by livingR. sphaeroideswas characterized by transmission electron microscopy (TEM). Culture time, as an important physiological parameter forR. sphaeroidesgrowth, could significantly control the size of cadmium sulfide nanoparticles. TEM demonstrated that the average sizes of spherical cadmium sulfide nanoparticles were 2.3 ± 0.15, 6.8 ± 0.22, and 36.8 ± 0.25 nm at culture times of 36, 42, and 48 h, respectively. Also, the UV–vis and photoluminescence spectral analysis of cadmium sulfide nanoparticles were performed

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Transfert bio-colloïdal dans des milieux poreux saturés et non-saturés : influence de l’hétérogénéité physique du milieu et des propriétés de cellules sur les mécanismes de transport et de dépôt bactérien

La compréhension du transport et du dépôt bio-colloïdal dans un milieu poreux présente un grand intérêt dans les applications environnementales, en particulier pour le contrôle de la bio-remédiation des sols et la protection des ressources en eau souterraine. Afin de mieux évaluer et prévenir les risques de contamination de la nappe phréatique et de proposer des solutions adéquates de remédiation, il est nécessaire d’avoir une bonne compréhension des mécanismes qui contrôlent le transport et le dépôt des bactéries dans les milieux poreux saturés et non saturés. L’objectif des ces travaux de thèse est d’étudier le rôle de l’hétérogénéité physique du milieu poreux (distribution granulométrique, porosité…) et de l’hydrodynamique du milieu sur les mécanismes de transport et de dépôt de particules bio-colloïdales, tout en prenant en compte l’impact des propriétés de cellules bactériennes sur ces mécanismes. Des expériences de traçage et d’injection de suspensions bactériennes ont été menées à l’échelle de colonnes de laboratoire dans trois milieux poreux avec une porosité et une distribution de taille de pore distincte. Afin de caractériser l’écoulement dans les milieux poreux, un soluté non-réactif a été utilisé comme traceur de l’eau. Trois souches bactériennes ont été utilisées pour préparer les suspensions bactériennes : une bactérie mobile (Escherichia coli), et deux non mobiles (Klebsiella sp. et R. rhodochrous). La caractérisation des propriétés cellulaires (telles que la taille et la forme des cellules, le potentiel zêta, la motilité et l'hydrophobicité) a été effectuée pour chaque souche. Des simulations numériques ont été réalisées en utilisant le code de calcul HYDRUS-1D afin de modéliser l’écoulement et d’estimer les paramètres de transport et de dépôt des bactéries. Ces derniers ont été explorés afin d'identifier le mode de transport bactérien et les mécanismes physico-chimiques ou physiques impliqués dans le dépôt des bactéries. Des expériences supplémentaires à l'échelle des pores ont été réalisées à l'aide de dispositifs microfluidiques conçus à cet effet. Un calcul théorique des différentes interactions entre les bactéries et le milieu poreux aux interfaces air/eau/solide a été effectué pour compléter les résultats expérimentaux ainsi que ceux issus de la modélisation numérique. Ainsi, les énergies d’interactions telles que les forces de van der Waals, électrostatiques de double couche, hydrophobes, stériques, capillaires et hydrodynamiques, impliquées dans le dépôt de bactéries ont été calculées pour décrire les interactions bactéries-interfaces afin d'identifier leur impact relatif sur le dépôt physico-chimique et physique des bactéries. Les résultats expérimentaux et la modélisation numérique ont mis en évidence un écoulement non uniforme, dépendant de la taille des grains ainsi que de la distribution de la taille des pores du milieu poreux. Pour un milieu poreux donné, l’écoulement devient plus dispersif quand la teneur en eau du milieu diminue. Ceci est dû à l’augmentation de la tortuosité du milieu, du fait de la présence de l’air dans les pores. Le transport des bactéries diffère de celui du traceur de l’eau. Le dépôt bactérien a été fortement influencé par la géométrie du réseau poral du milieu, les propriétés cellulaires et le degré de saturation en eau. Le piégeage physique et physico-chimique sont des mécanismes qui doivent être pris en compte pour bien décrire le dépôt bactérien, mais leur importance sur les mécanismes de dépôt est étroitement liée aux propriétés du milieu poreux et des cellules. Ces travaux mettent en évidence l’effet simultané des propriétés cellulaires, des propriétés physiques (granulométrie et distribution de taille de pores) et de l'hydrodynamique du milieu poreux sur les mécanismes de transport et de dépôt bactérien. Le calcul des différentes énergies d’interaction a permis d’identifier leur importance sur les mécanismes de dépôt bactérien.The investigation of the transport and retention of bacteria in porous media has a great practical importance in environmental applications, such as protection of the surface and groundwater supplies from contamination, risk assessment from microorganisms in groundwater, and soil bioremediation. The aim of this study is to gain a fundamental understanding of the mechanisms that control bacteria transport and deposition in saturated and unsaturated porous media. Laboratory tracer and bacteria transport experiments at Darcy scale were performed in three porous media with distinct pore size distribution in order to investigate and quantify water and bacteria transport process under steady state flow conditions. A conservative solute was used as water tracer to characterize water flow pathways through porous media. A gram negative, motile Escherichia coli, a gram negative, non-motile Klebsiella sp. and a gram positive, non-motile R. rhodochrous were selected for the transport experiments. Characterization of cell properties (such as cell size and shape, zeta potential, motility and hydrophobicity) was performed for each strain. Numerical simulations with HYDRUS-1D code were performed to characterize water flow and to estimate bacteria transport and deposition parameters. The later were explored to identify bacteria flow patterns and physicochemical or physical mechanisms involved in bacteria deposition. To provide a better understanding of the mechanisms involved on bacteria transport and deposition, pore scale experiments were carried out by using microfluidic devices, designed for this purpose. The information obtained from laboratory experiments and numerical modeling was improved by theoretical calculation of different interactions between bacteria and porous media at air/water/solid interfaces. DLVO and non-DLVO interactions such as hydrophobic, steric, capillary and hydrodynamic forces involved in bacteria deposition were considered to describe bacteria-interface interactions in order to identify their relative impact on physicochemical and physical deposition of bacteria. Results obtained through both laboratory experiments and numerical simulationsoutlined non-uniform flow pathways, which were dependent on both grain/pore size as well as pore size distribution of the porous media. For a given porous medium, water flow patterns became more non-uniform and dispersive with decreasing water saturation due to the presence of air phase, which lead to an increase of the tortuosity of the flow pathways under unsaturated conditions. Bacteria transport pathways were different from the tracer transport, due to size exclusion of bacteria from smaller pore spaces and bacteria motility. Bacteria deposition was greatly influenced by pore network geometry, cell properties and water saturation degree. Both physical straining and physicochemical attachment should be taken into account to well describe bacteria deposition, but their importance on bacteria deposition is closely linked to porous media and cell properties. The results obtained in this work highlighted the simultaneous role of cell properties, pore size distribution and hydrodynamics of the porous media on bacteria transport and deposition mechanisms. The calculation of DLVO and non-DLVO interactions showed that bacteria deposition in saturated and unsaturated porous media was influenced by both kinds of interactions

Comparison of transport between two bacteria in saturated porous media with distinct pore size distribution

International audienc

An Online Fault Pre-warning System of the Rolling Mill Screw-down Device Based on Virtual Instrument

Abstract: A traditional off-line screw-down monitoring system performs not well on real-time signal analysis or process, which cannot provide simultaneous fault pre-warning either. A diagnostic monitoring system as well as a remotely accessible graphic user interface is presented in this paper. The main objective of this work is to develop an online and available technique for monitoring the kinetic, hydrodynamic and electrical parameters of the rolling mill screw-down device, and analyze these figures to support online fault pre-warning. A series of transducers are installed in suitable locations to measure parameters decried above including the vibration acceleration of a rolling mill stand, the rolling force of a screw-down device, the stroke of a hydraulic cylinder, the system source pressure, the in-cylinder stress and the output value of an electro-hydraulic servo valve. An industrial personal computer picks up the information transformed by an extra high-speed data acquisition board embedded inside, processes the signals via a software designed by means of Laboratory Virtual Instrument Engineering Workbench (LabVIEW) and indicates fault conditions through the graphic user interface. Besides, the data of the overall system can be published over the Internet using LabVIEW Web Server capabilities. The results of experiments suggest that the system works well on real-time data acquisition and online fault prewarning. The statistics saved contributes to the research of vibration performance and malfunction analysis of a rolling mill. Copyright © 2014 IFSA Publishing, S. L

Use of Oxalic Acid-Modified Rice Husk for the Adsorption of Neutral Red from Aqueous Solutions

Rice husk modified with oxalic acid (MRH) was tested as a lowcost adsorbent for the removal of Neutral Red (NR) dye from aqueous solutions employing batch adsorption procedures. Such studies were conducted by varying various parameters such as the pH, the adsorbent dosage, the salt concentration, the contact time, the concentration of the adsorbate and the temperature. The kinetic experimental data were analyzed using three kinetic equations, viz. the pseudo-first-order equation, the pseudo-second-order equation and the intra-particle diffusion model equation, to examine the mechanism of adsorption and the potential rate-controlling step. The mechanism of the process was found to be complex, consisting of both surface adsorption and pore diffusion. The values of the effective diffusion parameter, D eff , were estimated to be of the order of 10 −8 cm 2 /s, indicated that intra-particle diffusion was not the rate-controlling step. The equilibrium adsorption data obtained at various temperatures were analyzed using the Langmuir, Freundlich and Redlich–Peterson isotherm models using non-linear regressive analysis. The equilibrium adsorption results were better fitted by the Langmuir and Redlich–Peterson isotherms relative to the Freundlich model. Calculated thermodynamic parameters showed that the adsorption of NR onto MRH was feasible, spontaneous and endothermic under the studied conditions. The carboxyl groups on the surface of the modified rice husk (MRH) were primarily responsible for the sorption of NR. It is suggested that MRH may be suitable as an adsorbent material for adsorbing NR from aqueous solutions