A Glimpse of Streptococcal Toxic Shock Syndrome from Comparative Genomics of S. suis 2 Chinese Isolates

BACKGROUND: Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen, causing more than 200 cases of severe human infection worldwide, with the hallmarks of meningitis, septicemia, arthritis, etc. Very recently, SS2 has been recognized as an etiological agent for streptococcal toxic shock syndrome (STSS), which was originally associated with Streptococcus pyogenes (GAS) in Streptococci. However, the molecular mechanisms underlying STSS are poorly understood. METHODS AND FINDINGS: To elucidate the genetic determinants of STSS caused by SS2, whole genome sequencing of 3 different Chinese SS2 strains was undertaken. Comparative genomics accompanied by several lines of experiments, including experimental animal infection, PCR assay, and expression analysis, were utilized to further dissect a candidate pathogenicity island (PAI). Here we show, for the first time, a novel molecular insight into Chinese isolates of highly invasive SS2, which caused two large-scale human STSS outbreaks in China. A candidate PAI of ∼89 kb in length, which is designated 89K and specific for Chinese SS2 virulent isolates, was investigated at the genomic level. It shares the universal properties of PAIs such as distinct GC content, consistent with its pivotal role in STSS and high virulence. CONCLUSIONS: To our knowledge, this is the first PAI candidate from S. suis worldwide. Our finding thus sheds light on STSS triggered by SS2 at the genomic level, facilitates further understanding of its pathogenesis and points to directions of development on some effective strategies to combat highly pathogenic SS2 infections

Effect of unsupervised Kinect-based mixed reality fitness programs on health-related fitness in men during COVID-19 pandemic: randomized controlled study

This study aimed to investigate the effect of Kinect-based mixed reality (KMR) exercise and unsupervised individual exercise on health-related fitness. A total of 27 participants underwent cardiorespiratory fitness tests for the inclusion criteria and were randomly assigned to three groups: a KMR group (KMRG), an unsupervised individual group (UIG), or a control group (CG). Pre and post-tests were conducted to measure Maximum oxygen uptake (VO₂max), body composition, upper and lower-body (LB) muscle strength, and endurance. KMRG and UIG attended exercise sessions 3 days per week for 8 weeks. KMRG used the KMR device and UIG used an instructive banner for exercise. All groups maintained their daily routines and submitted diet records every 4 weeks. Results showed that VO₂max, upper-body muscle endurance, and LB muscle endurance of knee extension was increased in KMRG and UIG. LB muscle strength in knee flexion was increased in UIG and LB muscle endurance in knee flexion was increased in KMRG. VO₂max, LB muscle strength, and LB muscle endurance were greater in KMRG than in CG. LB muscle strength in knee flexion was greater in KMRG than in UIG. Body fat was increased and skeletal muscle mass was decreased in CG. KMR exercise showed better performance than unsupervised individual (UI) exercise, and the exercise program was effective in both KMR and UI environments. These findings contribute to the growing evidence supporting the use of technology-based exercise interventions as a potential strategy to enhance health-related fitness

Research Progress on Polymer Solar Cells Based on PEDOT:PSS Electrodes

Solution-processed polymer solar cells (PSCs) have attracted dramatically increasing attention over the past few decades owing to their advantages of low cost, solution processability, light weight, and excellent flexibility. Recent progress in materials synthesis and devices engineering has boosted the power conversion efficiency (PCE) of single-junction PSCs over 17%. As an emerging technology, it is still a challenge to prepare solution-processed flexible electrodes for attractive flexible PSCs. Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) is one of the most promising candidates for electrodes due to its high conductivity (>4000 S/cm), excellent transmittance (>90%), intrinsically high work function (WF > 5.0 eV), and aqueous solution processability. To date, a great number of single-junction PSCs based on PEDOT:PSS electrodes have realized a PCE over 12%. In this review, we introduce the current research on the conductive complex PEDOT:PSS as well as trace the development of PEDOT:PSS used in electrodes for high performance PSCs and perovskite solar cells. We also discuss and comment on the aspects of conductivity, transmittance, work-function adjustment, film preparing methods, and device fabrications. A perspective on the challenges and future directions in this field is be offered finally

A Dramatic Marine Environment Change in the Beibu Gulf of the South China Sea around 3.2 kyr BP

AbstractThe profile geochemical characteristics of a seafloor sediment core, collected from the Beibu Gulf of the South China Sea, have been investigated in terms of the sediment grain size, the content of major and trace elements, the total organic carbon (TOC) and organic nitrogen (TN), and the carbon isotopic composition of organic matter (δ13Corg) and AMS 14C dating. These results show that the core sediments were deposited since 11.3 kyr BP and the profile could be clearly divided into the lower and upper sediment section based on geochemical characteristics. The lower section covers the depth of 86 cm to 200 cm and was deposited from 3.2 to 11.3 kyr BP, while the upper section is at the depth of 4 to 86 cm and represents sediments from 0.2 to 3.2 kyr BP. The upper section sediments are charcteristized by a much finer grain size and a clearly positive deviation of the δ13Corg value. Obviously, the overall profile geochemical characteristics indicate that the upper section was deposited under a significantly deeper seawater depth associated with a relatively weaker hydrodynamic and a better preservation condition for organic matter, while the low section was deposited under a relatively shallow seawater depth with the relatively stronger hydrodynamic condition and a relatively poor preservation condition for organic matter. Finally, it is suggested that the transition between the lower section and the upper section occurring around 3.2 kyr BP was mostly likely due to a dramatic marine environmental change caused by the rapid seafloor subsidence associated with the further expansion of the Qiongzhou Strait. And further multidisciplinary studies are needed to better reveal and understand different aspects of the significance of this marine environment change in the Beibu Gulf of the South China Sea

Energy-Saving Potential Comparison of Different Photovoltaic Integrated Shading Devices (PVSDs) for Single-Story and Multi-Story Buildings

Building-integrated photovoltaic (BIPV) façades are a promising technique for improving building energy performance. This study develops energy simulation models of different photovoltaic-integrated shading devices (PVSDs) in single-story and multi-story office buildings. A cross-region study in China is carried out to explore the energy performance of PVSDs in five climate zones. The shading effect of the upper PVSDs is taken into account. The results show that (1) PVSDs can be applicable in hot and cold climates; shading effects lead to a notable difference in the optimal PVSDs style. The average comprehensive energy saving ratios of different PVSDs ranged from 16.12% (fixed PV louvres in the vertical plane) to 51.95% (lower single panel). The most rewarding PVSDs are for single-story buildings in Kunming and the least suitable are for multi-story buildings in Guangzhou. (2) In climate zones with little air-conditioning energy consumption, avoiding considerably increased lighting consumption by PVSDs is vital. (3) To reduce shading effects, solar panels with smaller widths or vertical placements can be adopted. In addition, the distance of the PV modules from the top edge of the windows is also critical. Building performance evaluation in the early design stage enables maximum benefits for the same input (total area of PV panels). The research methodology and data analysis presented can guide parameters design and the geographical applicability of PVSDs, providing a reference for optimal building energy performance

Latest research at the advanced displays laboratory at NTU

There are many basic ways of providing a glasses-free 3D display and the three methods considered most likely to succeed commercially were chosen for our current research, these are; multi-layer light field, head tracked and super multiview displays. Our multi-layer light field display enables a far smaller form factor than other types, and faster algorithms along with horizontal parallax-only will considerably speed-up computation time. A spin-off of this technology is a near-eye display that provides focus cues for maximizing user comfort. Head tracked displays use liquid crystal display panels illuminated with a directional backlight to produce multiple sets of exit pupil pairs that follow the user's eyes under the control of a head position tracker. Our super multiview display (SMV) system uses high frame-rate projectors for spatio-temporal multiplexing that give dense viewing zones with no accommodation/convergence (A/C) conflict. Bandwidth reduction is achieved by discarding redundant information at capture. The status of the latest prototypes and their performance is described; and we conclude by indicating the future directions of our research.NRF (Natl Research Foundation, S’pore

Experimentally Identifying the Influences of Key Parameters for an Organic Rankine Cycle Using R123

As an efficient energy conversion technology, the organic Rankine cycle (ORC) has been widely applied in medium- and low-grade heat sources. In order to explore the experimental performance of ORC and reveal the effects of operation parameters, an experimental setup was built and R123 was selected as the working fluid. In the experiments, the heat source temperature as well as the mass flow rates of the working fluid and cooling water were controlled. Under the design conditions, the net work and cycle efficiency can, respectively, reach up to 0.55 kW and 8.7%. As for the influences of key parameters, with the increase in heat source temperature from 130 °C to 160 °C, the involved heat has a small increase, while the net work increases from 0.44 kW to 0.55 kW, and the cycle efficiency greatly increases from 6.71% to 8.72% at a mass flow rate of working fluid 25 g/s. As for the mass flow rate of cooling water, it has a similar impact on the cycle performances. The difference is that the effect of the cooling water rate is relatively smaller. At the mass flow rate 25 g/s, when the cooling water rate increases from 0.68 kg/s to 0.83 kg/s, the net work varies from 0.46 kW to 0.55 kW, the cycle efficiency increases in the range 7.41~9.4%. Furthermore, except cycle efficiency, all performances are proportional to the mass flow rate of working fluid. In the test range, the difference of cycle efficiency among different mass flow rates is less than 0.7%