It is important to understand the temporal trend of the paediatric severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load to estimate the transmission potential of children in schools and communities. We determined the differences in SARS-CoV-2 viral load dynamics between nasopharyngeal samples of infected asymptomatic and symptomatic children. Serial cycle threshold values of SARS-CoV-2 from the nasopharynx of a cohort of infected children were collected for analysis. Among 17 infected children, 10 (58.8%) were symptomatic. Symptomatic children, when compared to asymptomatic children, had higher viral loads (mean cycle threshold on day 7 of illness 28.6 vs. 36.7, P = 0.02). Peak SARS-CoV-2 viral loads occurred around day 2 of illness in infected children. Although we were unable to directly demonstrate infectivity, the detection of significant amount of virus in the upper airway of asymptomatic children suggest that they have the potential to shed and transmit SARS-CoV-2. Our study highlights the importance of contact tracing and screening for SARS-CoV-2 in children with epidemiological risk factors regardless of their symptom status, in order to improve containment of the virus in the community, including educational settings.

An acute gastroenteritis (AGE) outbreak caused by a norovirus occurred at a hospital in Shanghai, China, was studied for molecular epidemiology, host susceptibility and serological roles. Rectal and environmental swabs, paired serum samples and saliva specimens were collected. Pathogens were detected by real-time polymerase chain reaction and DNA sequencing. Histo-blood group antigens (HBGA) phenotypes of saliva samples and their binding to norovirus protruding proteins were determined by enzyme-linked immunosorbent assay. The HBGA-binding interfaces and the surrounding region were analysed by the MegAlign program of DNAstar 7.1. Twenty-seven individuals in two care units were attacked with AGE at attack rates of 9.02 and 11.68%. Eighteen (78.2%) symptomatic and five (38.4%) asymptomatic individuals were GII.6/b norovirus positive. Saliva-based HBGA phenotyping showed that all symptomatic and asymptomatic cases belonged to A, B, AB or O secretors. Only four (16.7%) out of the 24 tested serum samples showed low blockade activity against HBGA-norovirus binding at the acute phase, whereas 11 (45.8%) samples at the convalescence stage showed seroconversion of such blockade. Specific blockade antibody in the population played an essential role in this norovirus epidemic. A wide HBGA-binding spectrum of GII.6 supports a need for continuous health attention and surveillance in different settings.

This study estimates the incubation period of COVID-19 among locally transmitted cases, and its association with age to better inform public health measures in containing COVID-19. Epidemiological data of all PCR-confirmed COVID-19 cases from all restructured hospitals in Singapore were collected between 23 January 2020 and 2 April 2020. Activity mapping and detailed epidemiological investigation were conducted by trained personnel. Positive cases without clear exposure to another positive case were excluded from the analysis. One hundred and sixty-four cases (15.6% of patients) met the inclusion criteria during the defined period. The crude median incubation period was 5 days (range 1–12 days) and median age was 42 years (range 5–79 years). The median incubation period among those 70 years and older was significantly longer than those younger than 70 years (8 vis-à-vis 5 days, P = 0.040). Incubation period was negatively correlated with day of illness in both groups. These findings support current policies of 14-day quarantine periods for close contacts of confirmed cases and 28 days for monitoring infections in known clusters. An elderly person who may have a longer incubation period than a younger counterpart may benefit from earlier and proactive testing, especially after exposure to a positive case.

The present study investigated the association between fibre degradation and the concentration of dissolved molecular hydrogen (H2) in the rumen. Napier grass (NG) silage and corn stover (CS) silage were compared as forages with contrasting structures and degradation patterns. In the first experiment, CS silage had greater 48-h DM, neutral-detergent fibre (NDF) and acid-detergent fibre degradation, and total gas and methane (CH4) volumes, and lower 48-h H2 volume than NG silage in 48-h in vitro incubations. In the second experiment, twenty-four growing beef bulls were fed diets including 55 % (DM basis) NG or CS silages. Bulls fed the CS diet had greater DM intake (DMI), average daily gain, total-tract digestibility of OM and NDF, ruminal dissolved methane (dCH4) concentration and gene copies of protozoa, methanogens, Ruminococcus albus and R. flavefaciens, and had lower ruminal dH2 concentration, and molar proportions of valerate and isovalerate, in comparison with those fed the NG diet. There was a negative correlation between dH2 concentration and NDF digestibility in bulls fed the CS diet, and a lack of relationship between dH2 concentration and NDF digestibility with the NG diet. In summary, the fibre of CS silage was more easily degraded by rumen microorganisms than that of NG silage. Increased dCH4 concentration with the CS diet presumably led to the decreased ruminal dH2 concentration, which may be helpful for fibre degradation and growth of fibrolytic micro-organisms in the rumen.

A new developed spatially targeted mollusciciding technology for snail control was utilised in a research site. This study aims to analyse whether this technology can achieve rational effectiveness compared with the routine method. Snail density was monitored every spring and autumn from 2010 to 2017 at the research site and routine mollusciciding for snail control was then performed. After snail density monitoring in spring 2018, spatially targeted mollusciciding technology was adopted. Log-linear regression and nonlinear regression models were used for snail density prediction in autumn 2018 and the predicted value was compared with the actual snail density in autumn 2018 to verify the effectiveness of the spatially targeted mollusciciding. Monitoring results showed that overall snail density in the research site decreased from 2010 to 2018. The monitored snail density in autumn 2018 was 0.014/0.1 m2. Predicted by the log-linear regression model, the snail density in autumn 2018 would be 0.028 (95% CI 0.11–0.072)/0.1 m2. Predicted by the nonlinear regression model, the snail density growth in autumn 2018 in contrast to spring 2018 would be 79.79% (95% CI 54.81%–104.77%) and the actual value was 55.56%. Therefore, the effectiveness of the first application of spatially targeted mollusciciding was acceptable. However, the validation of its sustainable effectiveness still needs a replicated study comparing areas where targeted and untargeted methods are applied simultaneously and both snail abundance and human infection are monitored.

The species of Gagnepainia K.Schum. and Hemiorchis Kurz are revised throughout their ranges. These genera are shown with evidence from morphological and molecular studies to be distinct, although closely related to each other. Two species of Gagnepainia and three of Hemiorchis are recognised. A key to the genera of Globbeae and keys to the species of Gagnepainia and Hemiorchis are given, all names are typified and descriptions are provided. Conservation assessments of all taxa are proposed.

Non-communicable diseases (NCDs) including obesity, diabetes, and allergy are chronic, multi-factorial conditions that are affected by both genetic and environmental factors. Over the last decade, the microbiome has emerged as a possible contributor to the pathogenesis of NCDs. Microbiome profiles were altered in patients with NCDs, and shift in microbial communities was associated with improvement in these health conditions. Since the genetic component of these diseases cannot be altered, the ability to manipulate the microbiome holds great promise for design of novel therapies in the prevention and treatment of NCDs. Together, the Developmental Origins of Health and Disease concept and the microbial hypothesis propose that early life exposure to environmental stimuli will alter the development and composition of the human microbiome, resulting in health consequences. Recent studies indicated that the environment we are exposed to in early life is instrumental in shaping robust immune development, possibly through modulation of the human microbiome (skin, airway, and gut). Despite much research into human microbiome, the origin of their constituent microbiota remains unclear. Dust (also known as particulate matter) is a key determinant of poor air quality in the modern urban environment. It is ubiquitous and serves as a major source and reservoir of microbial communities that modulates the human microbiome, contributing to health and disease. There are evidence that reported significant associations between environmental dust and NCDs. In this review, we will focus on the impact of dust exposure in shaping the human microbiome and its possible contribution to the development of NCDs.

In this paper, the generation of relativistic electron mirrors (REM) and the reflection of an ultra-short laser off the mirrors are discussed, applying two-dimension particle-in-cell simulations. REMs with ultra-high acceleration and expanding velocity can be produced from a solid nanofoil illuminated normally by an ultra-intense femtosecond laser pulse with a sharp rising edge. Chirped attosecond pulse can be produced through the reflection of a counter-propagating probe laser off the accelerating REM. In the electron moving frame, the plasma frequency of the REM keeps decreasing due to its rapid expansion. The laser frequency, on the contrary, keeps increasing due to the acceleration of REM and the relativistic Doppler shift from the lab frame to the electron moving frame. Within an ultra-short time interval, the two frequencies will be equal in the electron moving frame, which leads to the resonance between laser and REM. The reflected radiation near this interval and corresponding spectra will be amplified due to the resonance. Through adjusting the arriving time of the probe laser, a certain part of the reflected field could be selectively amplified or depressed, leading to the selective adjustment of the corresponding spectra.

Introduction: Management of acute atrial fibrillation or flutter (AFF) in the emergency department (ED) can be performed with chemical or electrical cardioversion. Procainamide is the most common chemical agent used in Canada; however, there is substantial practice variation. The objective of this systematic review was to provide comparative evidence on return to normal sinus rhythm (NSR) and adverse events to better support clinical decisions. Methods: Systematic search of five electronic databases and grey literature. Randomized controlled trials (RCTs) and prospective controlled cohort studies including adults (≥17 years) with recent-onset of AFF comparing intravenous procainamide with other cardioversion strategies (e.g., electrical cardioversion, placebo or other antiarrhythmic drugs) were eligible. Two independent reviewers performed study selection and data extraction. Relative risks (RR) with 95% confidence intervals (CIs) were calculated using a random-effects model. The protocol was registered with PROSPERO (CRD42019142080). Results: From 4060 potentially relevant citations, 7 studies were considered eligible and three RCTs and two cohort studies included in the analysis. Procainamide was less effective in promoting return to NSR at 1st attempt compared to other chemical (RR 0.76; 95% CI: 0.65 to 0.90) and electrical (RR 0.58; 95% CI: 0.53 to 0.64) options. Electrical cardioversion was more effective in restoring NSR compared to procainamide when used as 2nd attempt in one RCT (RR 0.46; 95% CI: 0.23 to 0.92). Pre-specified serious adverse events were assessed and reported by two studies showing that hypotension was more common in patients receiving procainamide in comparison with electrical cardioversion (RR 20.57; 95% CI: 1.59 to 265.63). Treatment discontinuation due to adverse events was infrequently reported with only two studies reporting that no patients withdrew from the study following treatment with procainamide. The remaining studies provided incomplete data reporting on adverse events. Conclusion: Shared decision-making for patients with acute AFF in the ED requires knowledge of the effectiveness and safety of comparative interventions. Overall, procainamide is less effective than other chemical options and electrical cardioversion strategies to restore NSR. Evidence shows that hypotension is a concern when procainamide is administered; however, the overall adverse events information provided from the studies is suboptimal.

Prion diseases, or Transmissible Spongiform Encephalopathies (TSEs), are a group of fatal neurodegenerative disorders associated with a conformational transformation of the cellular prion protein (PrPC) into a self-feplicating and proteinase K (PK)-resistant conformer, scrapie PrP (PrPSc). Aggregates of PrPSc around neurons lead to neuropathologyical change including neuronal loss, astrogliosis, spongiform degeneration and deposition of amyloid plaques. Currently no effective treatment for prion disease exists. The development of novel therapeutic strategies against prion diseases has become a priority. Several reports have demonstrated that passive and active immune-based therapy can significantly prolong the incubation period of prionoses in vivo, and also some anti-PrP monoclonal can prevent PrP peptide toxicity in vitro. In this study, we have first time identified and purified anti-PrP antibodies from human intravenous immunoglobulin (IVIG) by using PrP peptide affinity chromatography column. The ratio of anti-PrP antibody and IVIG is about 1:1200. In vitro study indicates these anti-PrP antibodies strongly block PrP A117V peptide fibril formation and disrupt formation of fibrillar structures. Furthermore, these antibodies almost completely prevented neurotoxicity of PrP A117V peptide in cultured rat cerebellar granule neuron cultures (CGN). In contrast, immunoglobulins depleted of anti-PrP antibodies had little effect on PrP fibril formation or protection of neuronal cells. Our study suggests that human anti-PrP antibodies may interfere with the pathogenesis of prion disease and these purified antibodies may be a potential therapeutic agent to prevent or slow prion disease progression.

The present study aims to investigate the effect of wholegrain and legume consumption on the incidence of age-related cataract in an older Australian population-based cohort. The Blue Mountains Eye Study (BMES) is a population-based cohort study of eye diseases among older adults aged 49 years or older (1992–1994, n 3654). Of 2334 participants of the second examination of the BMES (BMES 2, 1997–2000), 1541 (78·3 % of survivors) were examined 5 years later (BMES 3) who had wholegrain and legume consumption estimated from the FFQ at BMES 2. Cataract was assessed using photographs taken during examinations following the Wisconsin cataract grading system. Multivariable-adjusted logistic regression models were used to assess associations with the 5-year incidence of cataract from BMES 2 (baseline) to BMES 3. The 5-year incidence of cortical, nuclear and posterior subcapsular (PSC) cataract was 18·2, 16·5 and 5·9 %, respectively. After adjustment for age, sex and other factors, total wholegrain consumption at baseline was not associated with incidence of any type of cataract. High consumption of legumes showed a protective association for incident PSC cataract (5th quintile: adjusted OR 0·37; 95 % CI 0·15, 0·92). There was no significant trend of this association across quintiles (P = 0·08). In this older Australian population, we found no associations between wholegrain intake at baseline and the 5-year incidence of three cataract types. However, intake of legumes in the highest quintile, compared with the lowest quintile, may protect against PSC formation, a finding needing replication in other studies.

Only a few studies have been performed on seed germination of perennial ephemeral species native to the cold deserts of central Asia. We hypothesized that seeds of the cold desert perennial ephemeral Leontice incerta exhibit versatility in the timing of germination, that is, having the capacity to germinate at any time in summer, autumn and next spring. At dispersal in late May, only about 30% of the seeds could germinate; thus, a high percentage of the seeds was dormant. Seeds had a fully developed embryo, and dry storage, cold stratification, warm stratification and gibberellin promoted germination; we concluded that they have non-deep physiological dormancy. Seeds buried under natural conditions during summer germinated to 57–86% in autumn (late October) when exhumed and incubated at 5/2–25/15°C. However, seeds were sown in soil exposed to natural temperature and (low) precipitation did not germinate until next spring when the soil was moist. Thus, like various cold desert annuals, seeds of the perennial L. incerta can germinate in summer, autumn and next spring, depending on the availability of soil moisture (rainfall). Rainfall in cold deserts can play an important role in shaping seed germination traits of desert plants.

Maternal and child health are intrinsically linked. With accumulating evidence over the past two decades supporting the developmental origins of health and diseases hypothesis, it is now widely recognised that nutrition in the first 1000 d sets the foundation for long-term health. Maternal diet before, during and after pregnancy can influence the developmental pathways of the fetus and lead to health consequences later in life. While maternal and infant mortality rates have declined significantly in the past two decades, the growing burden of obesity and chronic non-communicable diseases in women of reproductive age and children is on a rapid rise worldwide, in developed and developing countries. A key contributory factor is malnutrition, which is a consequence of consuming poor quality diets. Suboptimal macronutrient balance and micronutrient inadequacies can lead to undesirable maternal body composition and metabolism, in turn influencing the health of the mother and leading to longer-term metabolic and cognitive health consequences in the infant. The GUSTO (Growing Up in Singapore Towards healthy Outcomes) study, a mother–offspring multi-ethnic cohort study in Singapore, has contributed to this body of evidence over the past 10 years. This review will illustrate how nutritional epidemiological research through a birth cohort has illuminated the importance and urgency of maternal and child nutrition and health in a modern, industrialised setting. It underscores the importance of a number of critical nutrients during pregnancy, in combination with healthy dietary patterns and appropriate meal timing, for optimal maternal and child health.

Osteoporosis is a skeletal disease characterized by bone loss and bone microarchitectural deterioration. The combination of smart materials and stem cells represents a new therapeutic approach. In the present study, highly porous scaffolds are prepared by combining the conducting polymer PEDOT:PSS with collagen type I, the most abundant protein in bone. The inclusion of collagen proves to be an effective way to modulate their mechanical properties and it induces an increase in scaffolds’ electrochemical impedance. The biomimetic scaffolds support neural crest-derived stem cell osteogenic differentiation, with no need for scaffold pre-conditioning contrarily to other reports.