Heat resistant and tensile properties of glass fiber reinforced polymer composites

The study focuses on E glass fiber laminate with vinyl ester resin. Two types of fiber glass are used namely chopped strand mat (CSM) and woven roving (WR). The objective of this research is to determine the thermal conductivity, specific heat capacity and Modulus Young of glass fiber-reinforced polymer (GFRP) prepared by vacuum bagging resin infusion process. The samples of GFRP were exposed to cooking gas fire for 5 minutes and 10 minutes for fire test. The tensile test was also conducted for the three samples and the microstructure was analyzed using Scanning Electron Microscope (SEM) after tensile testing. The result discovered that WR sample was better than CSM sample because CSM sample yield an average value of 0.236 W/mK for thermal conductivity and 521.6 J/KgK for specific heat capacity while WR sample give a value of 0.205 W/mK for thermal conductivity and 589.5 J/KgK for specific heat capacity. The Modulus Young of WR sample is higher (24.2 GPa) compared with CSM sample (16.1 GPa). From SEM micrograph, the failure occurred on the samples were matrix cracking and fibers separation. From the fire and tensile test conducted, the damage occurred on the samples were quite the same with the failure of the reinforcement and matrix. The findings could be used in the building construction as engineers always looking for the best material as they may have the possibilities of fire exposure and tension load as well as this is a part of the safety requirement for buildings

Sensorimotor manipulations of the balance control loop-beyond imposed external perturbations

textabstractStanding balance relies on the integration of multiple sensory inputs to generate the motor commands required to stand. Mechanical and sensory perturbations elicit compensatory postural responses that are interpreted as a window into the sensorimotor processing involved in balance control. Popular methods involve imposed external perturbations that disrupt the control of quiet stance. Although these approaches provide critical information on how the balance system responds to external disturbances, the control mechanisms involved in correcting for these errors may differ from those responsible for the regulation of quiet standing. Alternative approaches use manipulations of the balance control loop to alter the relationship between sensory and motor cues. Coupled with imposed perturbations, these manipulations of the balance control loop provide unique opportunities to reveal how sensory and motor signals are integrated to control the upright body. In this review, we first explore imposed perturbation approaches that have been used to investigate the neural control of standing balance. We emphasize imposed perturbations that only elicit balance responses when the disturbing stimuli are relevant to the balance task. Next, we highlight manipulations of the balance control loop that, when carefully implemented, replicate and/or alter the sensorimotor dynamics of quiet standing. We further describe how manipulations of the balance control loop can be used in combination with imposed perturbations to characterize mechanistic principles underlying the control of standing balance. We propose that recent developments in the use of robotics and sensory manipulations will continue to enable new possibilities for simulating and/or altering the sensorimotor control of standing beyond compensatory responses to imposed external perturbations

Potensi Biotransformasi Ampas Tahu Menjadi Perisa Almond dengan Konsorsium Kapang-Bakteri sebagai Metode Alternatif Produksi Perisa Alami

Produksi perisa alami melalui ekstraksi bahan alam dinilai kurang efektif untuk memenuhi permintaan perisa alami yang terus meningkat. Biotransformasi gula dan/atau asam amino menjadi benzaldehid, yang merupakan komponen utama perisa almond, dapat menjadi metode alternatif porduksi perisa alami. Namun, akumulasi benzaldehid pada kultur dapat membunuh mikroba dan mengahsilkan yield terbatas. Hal tersebut menyebabkan biotransformasi sulit diaplikasikan pada produksi skala besar. Review naratif ini membahas potensi penggunaan konsorsium R. oligosporus dan P. putida serta potensi penggunaan substrat ampas tahu sebagai strategi peningkatan produksi dan resistensi benzaldehid pada proses biotransformasi. Studi dilakukan dengan metode deskriptif kualitatif. Hasil studi menunjukan interaksi sinergis antara R. oligosporus dan P. putida dapat meningkatkan resistensi kultur terhadap benzaldehid. Biofilm P. putida meningkatkan resistensi aktifitas antimikroba benzaldehid pada kultur hingga 3 kali lipat dibandingkan dengan monokultur R. oligoposrus. Peningkatan resistensi memungkinkan kultur mengalami peningkatan produksi benzaldehid hingga 74% atau mencapai 2.25 g/L. Penggunaan resin kromatografi HP20 yang ditambahkan pada kultur diketahui dapat mencegah benzaldehid pada kultur dimetabolisme Kembali oleh kultur menjadi senyawa lain &nbsp

PilT and PilU are homohexameric ATPases that coordinate to retract type IVa pili.

Bacterial type IV pili are critical for diverse biological processes including horizontal gene transfer, surface sensing, biofilm formation, adherence, motility, and virulence. These dynamic appendages extend and retract from the cell surface. In many type IVa pilus systems, extension occurs through the action of an extension ATPase, often called PilB, while optimal retraction requires the action of a retraction ATPase, PilT. Many type IVa systems also encode a homolog of PilT called PilU. However, the function of this protein has remained unclear because pilU mutants exhibit inconsistent phenotypes among type IV pilus systems and because it is relatively understudied compared to PilT. Here, we study the type IVa competence pilus of Vibrio cholerae as a model system to define the role of PilU. We show that the ATPase activity of PilU is critical for pilus retraction in PilT Walker A and/or Walker B mutants. PilU does not, however, contribute to pilus retraction in ΔpilT strains. Thus, these data suggest that PilU is a bona fide retraction ATPase that supports pilus retraction in a PilT-dependent manner. We also found that a ΔpilU mutant exhibited a reduction in the force of retraction suggesting that PilU is important for generating maximal retraction forces. Additional in vitro and in vivo data show that PilT and PilU act as independent homo-hexamers that may form a complex to facilitate pilus retraction. Finally, we demonstrate that the role of PilU as a PilT-dependent retraction ATPase is conserved in Acinetobacter baylyi, suggesting that the role of PilU described here may be broadly applicable to other type IVa pilus systems

High prevalence of hepatitis B virus genotype C/C1 in the Minangkabau ethnic group in Indonesia

<p>Abstract</p> <p>Background</p> <p>The Minangkabau is one of the major ethnic groups in Indonesia. Previous studies with a limited number of samples have shown a different prevalence of HBV/C in the Minangkabau compared to the Indonesian population in general. The aim of this study was to assess the HBV genotype distribution pattern and the prevalence of pre-S, T1753V and A1762T/G1764A mutations among the Minangkabau HBV carriers. The samples were collected from Padang, West Sumatera and from western Java. Mixed primers for specific genotypes were used to determine the HBV genotype. Pre-S or S genes were amplified, sequenced and aligned with reference sequences from GenBank to derive a phylogenetic tree for subgenotyping. Pre-S genes were also analyzed for mutations. The basal core promoter (BCP) region was amplified and directly sequenced to analyze T1753V and A1762T/G1764A mutations.</p> <p>Results</p> <p>The predominant HBV genotype among the Minangkabau HBV carriers (n=117) was C (72.6%) followed by B (24.8%) and co-infection with B and C (2.6%). The prevalence of pre-S mutations, including both the pre-S deletion and pre-S2 start codon mutation, was 41.0%, and the T1753V and A1762T/G1764A mutations were found in 51.9% and 71.2% respectively. HBV/C1 was the predominant HBV subgenotype in the Minangkabau HBV carriers, and was found in 66.2%, followed by B3, B7, C8, B2, B9, C2, and C10 (18.3%, 7.0%, 2.8%, 1.4%, 1.4%, 1.4%, and 1.4% respectively). From samples that were found to be co-infected with HBV B and C, two samples were successfully cloned and subgenotyped, including one with mixed subgenotypes of B3 and C1, and another one with mixed subgenotypes of B7, C1, putative intergenotypic of B/A, and C/A. Furthermore, three samples from donors of non-Minangkabau ethnicity from Padang were found to be infected with an intragenotypic recombination form, including a putative recombinant of B8/B3 and B9/B7.</p> <p>Conclusion</p> <p>HBV/C with subgenotype C1 was the predominant HBV genotype among HBV carriers of Minangkabau ethnicity. The prevalence of pre-S, A1762T/G1764A, and T1753V mutations was higher among the Minangkabau compared to Indonesian HBV carriers in general.</p

Monitoring healthcare-associated infections and antimicrobial use at regional level through repeated point prevalence surveys: what can be learnt?

Abstract BACKGROUND: Healthcare-associated infections (HAIs) surveillance is an essential part of any infection prevention and control programme. Repeated point prevalence surveys (PPSs) according to European Centre for Disease Prevention and Control (ECDC) protocol have been implemented in all Friuli Venezia Giulia (FVG) region (Italy) acute hospitals to reduce and control HAIs. AIM: Using the repeated PPSs within a regional-healthcare system (RHS) to promote and evaluate infection prevention and control (IPC) programmes. METHODS: The standard versions of the ECDC PPS protocols were used in all four surveys (2011, 2013, 2015, 2017). All RHS public and private accredited hospitals were involved within the 'safe care network' programme. FINDINGS: The numbers of surveyed patients in the four PPSs were 3172, 3253, 2969 and 3036, respectively. Prevalence of HAIs and antimicrobial use (AU) decreased significantly from 2011: HAIs (P<0.05) 7.1%, 6.3%, 5.5%, 5.8% and AU (P<0.01) 40.4%, 39.2%, 36.0%, 37.2%, respectively. The appropriateness of duration of surgical prophylaxis increased significantly (<24\u202fh increased through surveys related to one in 2011: odds ratio (OR), 95% confidence interval (CI) 1.29, 0.92-1.81; 1.95, 1.31-2.91; 1.78, 1.20-2.64, respectively). The most frequently detected HAIs were: bloodstream, urinary tract, pneumonia and surgical site (more than the 70% of HAIs in each PPS). CONCLUSION: The FVG regional approach to HAIs and AU surveillance was able to contribute to reduce prevalence over a 7-year period. Furthermore, it was able to keep hospital attention on HAIs and AU through the years and to guarantee a standardized and comparable evaluation of HAIs and AU burden in all RHS hospitals, as well as impacting on HAIs and AU regional programmes