Minimum and Maximum Limit to Number of Myosin II Motors Participating in an Ensemble Motility

Extensive research on centrifugal compressors has been planned to define diffuser stall limits for a group of stages characterized by low blade-outlet-width-to-impeller-radius-ratio. Very little data is available on this centrifugal compressor family, especially for the last stage configuration. In addition, the most important stall diffuser prediction criteria barely cover this machine type. Many experimental tests have been planned to investigate several geometry variations. A simulated stage with a backward channel upstream, a 2D impeller with a vaneless diffuser and a constant cross section volute downstream constitute the basic geometry. Several diffuser geometries with different widths, pinch shapes, diffusion ratios were tested. Test results and conclusions are shown in the paper in terms of critical diffuser inlet flow angles, flow coefficients at stall inception and stage working ranges. The main task of the present work is to increase the knowledge and the amount of available data to characterize rotating stall phenomena, in particular for very narrow stages

Antimicrobial resistance in patients with suspected urinary tract infections in primary care in Assam, India

OBJECTIVES: We investigated the prevalence and diversity of antimicrobial resistance in bacteria isolated from urine samples of community-onset urinary tract infection (UTI) patients in southern Assam, India. METHODS: Freshly voided midstream urine samples were collected from patients attending primary healthcare centres, with the patients’ epidemiological data also recorded. Species identification was confirmed using a VITEK 2 compact automated system. Phenotypic confirmation of ESBLs was performed using the combined disc diffusion method (CLSI 2017) and carbapenemase production was phenotypically characterized using a modified Hodge test. Common ESBLs and carbapenem-resistance mechanisms were determined in Escherichia coli isolates using PCR assays. Incompatibility typing of the conjugable plasmids was determined by PCR-based replicon typing; the phylotypes and MLSTs were also analysed. RESULTS: A total of 301 (59.7%) samples showed significant bacteriuria along with symptoms of UTI and among them 103 isolates were identified as E. coli of multiple STs (ST3268, ST3430, ST4671 and others). Among them, 26.2% (27/103) were phenotypically ESBL producers whereas 12.6% (13/103) were carbapenemase producers. This study describes the occurrence of diverse ESBL genes—bla(CTX-M-15), bla(SHV-148), bla(PER-1) and bla(TEM)—and two E. coli isolates carrying the bla(NDM-1) carbapenemase gene. ESBL genes were located within transconjugable plasmids of IncP and IncF type whereas bla(NDM-1) was carried in an IncF(repB) type plasmid. CONCLUSIONS: This study illustrates the high rate of MDR in E. coli causing UTI in primary care in rural Assam. UTIs caused by ESBL- or MBL-producing bacteria are very difficult to treat and can often lead to treatment failure. Thus, future research should focus on rapid diagnostics to enable targeted treatment options and reduce the treatment failure likely to occur with commonly prescribed antibiotics, which will help to combat antimicrobial resistance and the burden of UTIs

New perspectives on photosynthetic phosphorylation in the light of a torsional mechanism of energy transduction and ATP synthesis.

Abstract New perspectives on photophosphorylation have been offered from the standpoint of the torsional mechanism of energy transduction and ATP synthesis. New experimental data on the involvement of malate anions in ATP synthesis in an acid-base malate bath procedure has been reported on spinach chloroplast thylakoids as the model system. The data cannot be reconciled with the chemiosmotic theory but has been shown to be naturally explained by the torsional mechanism. The path of malic acid in the acid and base stages of the experiment has been traced, offering further strong support to the new paradigm. Classical observations in the field have been re-interpreted in the light of these findings. A new concept of ion translocation, energy transduction and coupling at the overall physiological level in photophosphorylation has been presented and a large number of novel experimentally testable predictions have been made and shown to arise as logical consequences of the new perspectives

Fructooligosaccharides: Production by recombinant fructosyltransferase from Festuca arundinacea in a continuous reactor and kinetic modeling profile

In the quest for maximum conversion of sucrose into 1-kestose using fructosyltransferases in a continuous reactor, consideration of the reversible reactions at competing concentrations of sucrose and 1-kestose is crucial. In this study, a kinetic model based on a combined approach of rapid equilibrium and steady-state kinetics was developed to predict the profile of FOS production using recombinant sucrose: sucrose 1-fructosyltransferase from Festuca arundinacea produced in Pichia pastoris. The purified enzyme selectively converted sucrose into 1-kestose with a final yield of 0.66 g/g sucrose consumed. The reaction rate laws adequately described the kinetic profile of the substrate and the products and accurately predicted the composition of the reaction mixture. The model was fitted to experimental data obtained at three enzyme dosages and three initial sucrose concentrations. The model could predict the effect of substrate concentration on initial rate kinetics, half-saturation constant, and transferase to hydrolase ratio. For the known values of initial sucrose and enzyme concentration, the optimum reaction time and the required dilution rate were predicted for the development of a continuous process to produce 1-kestose-enriched short-chain FOS. A volumetric productivity of ∼110 g/L/h of 1-kestose with 40 % carbohydrate composition in the permeate flux was demonstrated

Correction: Highly-sensitive detection of Salmonella typhi in clinical blood samples by magnetic nanoparticle-based enrichment and in-situ measurement of isothermal amplification of nucleic acids.

[This corrects the article DOI: 10.1371/journal.pone.0194817.]

Genotypes and phenotypes of methicillin‐resistant staphylococci isolated from shrimp aquaculture farms

Not AvailableThe population of methicillin-resistant (MR) staphylococci in aquatic environment is rarely investigated. Here, we characterized a collection of MR staphylococci recovered from shrimp aquaculture farms (n = 37) in Kerala, India. A total of 261 samples yielded 47 MR isolates (16 S. aureus, 13 S. haemolyticus, 11 S. epidermidis, 3 S. saprophytics and 2 each of S.intermedius and S. kloosii). Multi-drug resistance was evident in 72.3 % of the isolates, with resistance mainly towards erythromycin (78.7 % ), norfloxacin and trimethoprim-sulfamethoxazole (53.2 % ), and gentamicin (34 % ). Major resistance genes identified included mecA (100 % ), ermC (38.3 % ), aacA-aphD (21.3 % ), tetK (14.9 % ) and tetM (21.3 % ). Almost 60 % of the isolates carried type V SCCmec (Staphylococcal Cassette Chromosome mec), and the remaining harboured untypeable SCCmec elements. Comprehensive genotyping of the methicillin-resistant Staphylococcus aureus isolates revealed high prevalence of ST772-t345-V (sequence type-spa type-SCCmec type) (75 % ), followed by minor representations of ST6657-t345-V and ST3190-t12353. The isolates of S. haemolyticus and S. epidermidis were genotypically diverse as shown by their pulsed-field gel electrophoresis (PFGE) profiles. Genes encoding staphylococcal enterotoxins were observed in 53.2 % of the isolates. Various genes involved in adhesion and biofilm formation were also identified. In conclusion, our findings provide evidence that shrimp aquaculture settings can act as reservoirs of methicillin-resistant staphylococci.Not Availabl