A Design of Digital Microfluidic Biochip along with Structural and Behavioural Features in Triangular Electrode Based Array

AbstractDigital microfluidic based biochip manoeuvres on the theory of microfluidic technology, having a broad variety of applications in chemistry, biology, environmental monitoring, military etc. Being concerned about the technological advancement in this domain, we have focused on equilateral triangular electrodes based DMFB systems. Accepting the associated design issues, here, we have addressed many facets of such electrodes regarding their structural and behavioural issues in comparison to the existing square electrodes. As the requisite voltage reduction is a key challenging design issues, to implement all the tasks using triangular electrodes that are possible in square electrode arrays as well, is a tedious job. Furthermore, to deal with this new design deploying triangular electrodes, we have analyzed all the necessary decisive factors including fluidic constraints to ensure safe droplet movements and other modular operations together with mixing and routing. Moreover, an algorithm has been developed to find a route for a given source and destination pair in this newly designed DMFB. Finally, we have included a comparative study between this new design and the existing one while encountering the above mentioned issues

Analysis of Free and Bound NADPH in Aqueous Extract of Human placenta Used as Wound Healer.

NADPH is an important biomolecule involved in cellular regeneration. The distribution of free and bound NADPH in aqueous extract of human placenta used as a potent wound healer has been analyzed. Quantification from fluorescence and immuno-affinity chromatography indicates that 75.1±2.2% of NADPH present in the extract exists as free nucleotide or bound to very small peptides or amino acids whereas the rest remains bound to large peptides. Inability to dissociate the bound form of the nucleotide from the large peptides using urea or guanidium hydrochloride indicates that the binding is covalent. Identification of a fragmented mass of m/z 382.94 (nicotinamide + sugar + phosphate) from the NADPH-peptide conjugates supported the intactness of the nicotinamide moiety. Glutathione reductase assay indicated that 95.2±3.5% of the total NADPH pool of the extract can act as cosubstrate of the enzyme. This indicates that while a major fraction of free NADPH of the extract is easily available for cellular processes, the rest can also function locally where the conjugated peptides are deposited

Ventilator-associated pneumonia: Its incidence, the risk factor and drug resistance pattern in a tertiary care hospital

Background: Ventilator-associated pneumonia (VAP) is an infection of the lung that develops 48 h or longer after mechanical ventilation. Objectives: The present study was aimed to find out the bacteriological profile of VAP along with the resistance pattern of bacteriological isolates. Materials and Methods: A prospective observational study was conducted from January 2013 to May 2014 among 791 patients admitted in critical care units of our tertiary care hospital. After selection by applying inclusion and exclusion criteria endotracheal aspirates were collected from ventilated patients. Samples were subjected to further processing by Gram-staining, culture, biochemical testing and antibiogram. Results : Out of 791 patients admitted in intensive care unit in this tertiary care hospital with VAP 540 (68.2%) patients were culture positive. Pseudomonas aeruginosa was most commonly isolated pathogen of both early onset and late onset VAP. In early VAP Acinetobacter baumannii showed 62.5% metallo-beta-lactamase (MBL) positivity. P. aeruginosa showed 27.5% MBL positivity, whereas in late onset VAP, 71.4% A. baumannii isolates and 75.8% P. aeruginosa isolates showed MBL positivity, respectively. Conclusion : Simple prevention of aspiration, sterilization of equipments, hand washing of personnel can reduce VAP in hospital care setting

In vitro induction of nitric oxide by mouse peritoneal macrophages treated with human placental extract

Nitric oxide (NO) is an important cellular mediator of tissue repair. It is produced in macrophages by the enzyme inducible nitric oxide synthase (iNOS) during wound healing. An aqueous extract of human placenta used as wound healer, has been investigated in terms of induction of NO by mouse peritoneal macrophages as well as human monocyte derived macrophages. NO production was estimated in macrophages culture supernatants. Incubation of 0.1 to 20 mg/ml of placental extract with 2 × 106 cells in vitro produced 10 to 100 μ M of nitrite (n = 4) in a dose dependent manner suggesting production of NO. With increase of NO production, NADPH present in the applied extract decreased proportionately. Application of L-NG monomethyl arginine (L-NMMA), an NO synthase (NOS) inhibitor, reduced the production of NO at the basal level. Dose dependent release of IFN-γ with respect to placental extract by the mouse macrophages was observed. It has been observed that human monocytes derived macrophages also produced significant amount of NO by induction of the extract. Similar induction of NO by placental extract in presence and absence of polymyxin B suggested that this property is not likely to be mediated by the endotoxin/LPS

Catalytic Enantioselective Hydrogenolysis of [Cr(CO)3(5,8-Dibromonaphthalene)]

Split and run: A study of the asymmetric hydrogenolysis of an aryl-carbon-bromine bond in a naphthalene chromiumtricarbonyl complex shows the use of a new bulky phosphoramidite ligand to yield the product in highly enantiomerically enriched form (see scheme)

CHIKUNGUNYA, SCRUB TYPHUS MONO, AND CO-INFECTION AMONG PATIENTS WITH UNDIFFERENTIATED FEBRILE ILLNESS: A HOSPITAL-BASED STUDY

Objectives: Chikungunya virus is a common arthropod-related acute febrile disease and it is transmitted by Aedes aegypti or Aedes albopictus species. On the other hand, the bacterium Orientia tsutsugamushi causes scrub typhus, which is also an acute febrile illness with multiple organ involvement. Coinfection of chikungunya and scrub typhus may lead to severe manifestation including severe respiratory and central nervous system (CNS) complications. Coinfection of chikungunya and scrub typhus may lead to severe manifestation including severe respiratory and CNS complications. Therefore, the proper diagnosis can prevent the clinical complications. The aim and objective of our study is to find the seroprevalence of chikungunya and scrub typhus and coinfection of both through medical assessment and serological research of these patients presented with acute febrile infection at Diamond Harbour Government Medical College and Hospital. Methods: A prospective study was conducted from August 2022 to January 2023 at VRDL, Department of Microbiology, Diamond Harbour Government Medical College and Hospital. Serum was collected for IgM antibody enzyme-linked immunosorbent assay (ELISA) for scrub typhus (In bios kit) and Chikungunya (NIV Chikungunya IgM Capture ELISA Kit) test. Four hundred and eighty-seven samples were tested for IgM antibody by chikungunya and scrub typhus ELISA kit. Result: The present study demonstrated that, from the month of August 2022 to January 2023, 67% of chikungunya cases, 25% cases with only scrub typhus, and 8% cases with both chikungunya and scrub typhus presented positive. A present study shows that chikungunya is slightly more prevalent in males as compared to females, where scrub typhus is equally positive in both male and female patients. Conclusion: Laboratory testing of both of the diseases can prevent the complication of other suspected disease in coinfected patients

Glycosylation of the core of the HIV-1 envelope subunit protein gp120 is not required for native trimer formation or viral infectivity

The gp120 subunit of the HIV-1 envelope (Env) protein is heavily glycosylated at similar to 25 glycosylation sites, of which similar to 7-8 are located in the V1/V2 and V3 variable loops and the others in the remaining core gp120 region. Glycans partially shield Env from recognition by the host immune system and also are believed to be indispensable for proper folding of gp120 and for viral infectivity. Previous attempts to alter glycosylation sites in Env typically involved mutating the glycosylated asparagine residues to structurally similar glutamines or alanines. Here, we confirmed that such mutations at multiple glycosylation sites greatly diminish viral infectivity and result in significantly reduced binding to both neutralizing and non-neutralizing antibodies. Therefore, using an alternative approach, we combined evolutionary information with structure-guided design and yeast surface display to produce properly cleaved HIV-1 Env variants that lack all 15 core gp120 glycans, yet retain conformational integrity and multiple-cycle viral infectivity and bind to several broadly neutralizing antibodies (bNAbs), including trimer-specific antibodies and a germline-reverted version of the bNAb VRC01. Our observations demonstrate that core gp120 glycans are not essential for folding, and hence their likely primary role is enabling immune evasion. We also show that our glycan removal approach is not strain restricted. Glycan-deficient Env derivatives can be used as priming immunogens because they should engage and activate a more divergent set of germlines than fully glycosylated Env. In conclusion, these results clarify the role of core gp120 glycosylation and illustrate a general method for designing glycan-free folded protein derivatives