Prevalence,characterization, and genetic diversity of Listeria monocytogenes isolated from foods of animal origin in North East India

Listeria monocytogenes is a pathogenic microorganism infects man mostly through food. A total of 1615 samples of foods of animal origin and water were collected from retail meat shops of North-Eastern India and processed. Sixty-three (3.9%) samples were positive for L. monocytogenes. Animal origin foods showing the highest prevalence was chevon (9.8%) followed by beef (8.9%), chicken (8.5%), pork (2.8%) and milk (1.8%). The prevalence rate in water from retail meat shops was 10%. Recovered L. monocytogenes were distributed into 3 serogroups, of which 74.6% fit in to 1/2a, 3a serogroup, 17.5% to 1/2b, 3b and 7.9 % to 4b, 4d, 4e serogroups. Thirty-five isolates out of 63 possessed all the tested four virulence genes. RAPD- and ERIC -PCR based analyses jointly revealed a discriminative genetic profile for the L. monocytogenes. On the whole, the occurrence of L. monocytogenes in foods of animal origin of North Eastern India displays public health hazard.     

再生纤维的能效筛选

当今的高速印刷机械和造纸机械对纤维质量和浆料的洁净度提出了更严格的要求。借助于优化的筛选工艺可以以高的生产效率和低的能耗达到所要求的浆料质量。     

Bioelectric Responses of Conjunctival Goblet Cells to Dry Eye: Impact of Ion Channels on Exocytotic Function and Viability

How ion channels impact the response of the ocular surface to dry eye is only beginning to be explored. Here, we review recent progress and provide new experimental data clarifying the exocytosis-altering actions of ion channels in conjunctival goblet cells whose release of tear-stabilizing mucin is a key adaptive response to the pre-ocular hyperosmolarity that characterizes dry eye. Patch-clamp recordings of goblet cells located in freshly excised rat conjunctiva reveal that these mucin-releasing cells respond to sustained hyperosmolarity by sequentially activating their ATP-sensitive potassium (K_ATP), nonspecific cation (NSC), voltage-gated calcium (VGCC), and P2X₇ channels; each of which modulates exocytosis. Based on these and other new findings, we now identify four stages in the bioelectric response of conjunctival goblet cells to extracellular hyperosmolarity. To better characterize these stages, we report that high-resolution membrane capacitance (Cm) measurements of the exocytotic activity of single goblet cells demonstrate that the replenishment of mucin-filled granules after neural-evoked exocytosis is a multi-hour process, which VGCCs markedly accelerate. Yet, we also discovered that VGCC activation is high-risk since hyperosmotic-induced goblet cell death is boosted. With dry eye treatments being far from optimal, elucidating the physiologic and pathobiologic impact of the K_ATP/NSC/VGCC/P2X₇ pathway provides a new opportunity to identify novel therapeutic strategies.     

Impact of P2X7 Purinoceptors on Goblet Cell Function: Implications for Dry Eye

By providing ~70% of the eye’s refractive power, the preocular tear film is essential for optimal vision. However, its integrity is often jeopardized by environmental and pathologic conditions that accelerate evaporation and cause sight-impairing dry eye. A key adaptive response to evaporation-induced tear film hyperosmolarity is the reflex-triggered release of tear-stabilizing mucin from conjunctival goblet cells. Here, we review progress in elucidating the roles of ion channels in mediating this important exocytotic response. Much is now known about the modulatory impact of ATP-sensitive potassium channels, nonspecific cation channels and voltage-gated calcium channels. Recently, we discovered that during unremitting extracellular hyperosmolarity, P2X₇ receptor/channels also become activated and markedly impair goblet cell viability. However, our understanding of possible adaptive benefits of this P2X₇ activation remains limited. In the present study, we utilized high-temporal resolution membrane capacitance measurements to monitor the exocytotic activity of single goblet cells located in freshly excised rat conjunctiva. We now report that activation of P2X₇ purinoceptors boosts neural-evoked exocytosis and accelerates replenishment of mucin-filled granules after exocytotic depletion. Thus, P2X₇ activation exerts a yin-yang effect on conjunctival goblet cells: the high-gain benefit of enhancing the supply of tear-stabilizing mucin is implemented at the high-risk of endangering goblet cell survival.     

Activation of NMDA receptor-channels in human retinal Müller glial cells inhibits inward-rectifying potassium currents

No reliable culture system exists for B-lineage acute lymphoblastic leukaemia (ALL). Recently we found that many different mature B-cell malignancies proliferate upon stimulation via the CD40 antigen, and this led us to investigate whether a similar CD40 activation on ALL cells could also induce proliferation. First, we measured CD40 expression in 21 ALL cases; all were CD40+, although mostly weak. Next, we triggered the CD40 antigen by anti-CD40 antibodies and by a CD40 ligand-expressing cell line. In addition, we measured the influence of IL-3, IL-4 and IL-7 with and without these stimuli. In 8/10 cases proliferation, measured by 3H-thymidine incorporation, could be induced after CD40 crosslinking, especially in the presence of IL-3. Stimulation via the CD40 ligand was more successful than using crosslinked anti-CD40 antibodies. IL-4 inhibited the spontaneous proliferation found in three cases, but stimulated proliferation after CD40 crosslinking. IL-7 did not contribute to proliferation. Morphology, immunophenotyping and surface marker analysis, combined with DNA flow cytometry confirmed that the proliferation found could be ascribed to the ALL cells. In conclusion, B-lineage ALL cases are CD40+, and many can be cultured using CD40 stimulation and IL-3.     

Learning game for improving forklift drivers’ safety awareness

Cognition, Technology & Work - Forklift drivers in in-house logistics are at a high risk of occupational injuries. This study piloted a video-based learning game for forklift drivers, designed...     

Performance of RC and PES ultrafiltration membranes in filtration of pulp mill process waters

Issues of fouling and effective cleaning limit the adoption of UF in pulp and paper mill applications. The choice of an optimal membrane for a specific filtration application is a challenging task due to the fact that fouling is a complex phenomenon. This study compares regenerated cellulose (RC) and polyethersulphone (PES) membranes in UF of two chemithermomechanical pulp mill process waters. The process waters originated from hardwood and softwood pulping. Based on their flux recovery, PES membranes sustained greater fouling than RC membranes even though the hydrophobicity of RC membranes was increased remarkably by adsorptive fouling. The process water affected the performance of the membranes. The membrane characteristics were more important in determining fouling when softwood process water was used than when hardwood process water was used. Hydrophilicity and morphology of the membranes were seen to have a clear influence on fouling.     

Plasma-induced changes in the physiology of mammalian retinal glial cells: role of glutamate

Plasma can leak into the nervous system when the vascular endothelial barrier is compromised. Although this occurs commonly, little is known about the effects of plasma on the function of cells in the central nervous system. In this study, we focused on the responses of glial cells, which, because they ensheathe the blood vessels, are the first cells exposed to leaking plasma. We used the perforated-patch configuration of the patch-clamp technique to assess the effects of plasma on freshly dissociated bovine and human Müller cells, the principal glia of the retina. To monitor the function of Müller cells in situ, we recorded electroretinograms from isolated retinas. We found that plasma activates an electrogenic glutamate transporter and inhibits inward-rectifying K+ channels, as well as a transient outward current. Glutamate, a normal constituent of the blood, mimicked these effects. Unlike our recent findings with serum, which contains molecules generated by the clotting process, plasma neither activated a nonspecific cation conductance nor inhibited the slow P(III) component of the electroretinogram, which is generated by Müller cells responding to light-evoked changes in the extracellular potassium concentration ([K+]o). Taken together, our observations indicate that a leakage of serum into the retina compromises the regulation of [K+]o by Müller cells; however, when plasma enters the retina at sites of a breakdown in the blood-retinal barrier, these glia can maintain K+ homeostasis while reducing the potentially neurotoxic levels of glutamate.     

Complete determination of stress in fiber preforms of arbitrarycross section

An algorithm for determination of all the stress components in fiber preforms is presented. Complete stress distribution in a bow-tie type fiber preform has been determined. The reliability of the results has been checked using macro static equilibrium conditions     

Inverse problem of thermoelasticity of fiber gratings

Photoelasticity permits measurement of the axial stress distribution in optical fibers and fiber preforms of arbitrary cross section. Determination of other components of stress tensor is possible only with the use of additional information. The aim of this publication is to develop an algorithm for reconstructing stresses in circular waveguides based on the thermoelasticity model. Thus, it is assumed that there exists a temperature field T(x, y, z), which causes a stress field, equal to the stress pattern. The algorithm of reconstruction of stresses in fiber gratings is presented in the frame of nonhomogeneous elasticity.