Understanding the impact of heatwave on urban heat in greater Sydney: Temporal surface energy budget change with land types.

The impact of heatwaves (HWs) on urban heat island (UHI) is a contentious topic with contradictory research findings. A comprehensive understanding of the response of urban and rural areas to HWs, considering the underlying cause of surface energy budget changes, remains elusive. This study attempts to address this gap by investigating a 2020 HW event in the Greater Sydney Area using the Advanced Weather Research and Forecasting (WRF) model with 250-m high resolution. Findings indicate that the HW intensifies the nighttime surface UHI by approximately 4 °C. An analysis of surface energy budgets reveals that urban areas store more heat during the HW due to receiving more solar radiation and less evapotranspiration compared to rural areas. The maximum heat storage flux in urban during the HW can be around 200 W/m2 higher than that during post-HW. The stored heat is released at nightime, raising the air temperature in the urban areas. Forests and savannas have relatively lower storage heat fluxes due to high transpiration and albedo, and the maximum heat storage flux is only around 50 W/m2 higher than that during post-HW. In contrast, a negative synergistic effect is detected between the 2-m UHI and HW. This may be because other meteorological conditions including wind have substantial impacts on the air temperature pattern. The strong hot and dry winds coming from the west resulted in a higher air temperature in the western urban district, and intra-city disparities are higher. Meanwhile, the western forest area also experiences higher temperatures due to the westward winds. In addition, changes in wind direction alter the temperature distribution in the northern rural region. The findings of the present study may provide some insights into urban heat mitigation during HW.

Self-Assessment of INTERHEART Risk Stratification among the Middle-Aged Community in Malaysia.

Research background and Objectives: Age is an independent risk factor for cardiovascular disease (CVD), but CVD risk factors are preventable, and lack of awareness of its risk factors is a contributing factor to CVDs. Middle-aged people may be more likely to engage in unhealthy lifestyle behaviours which can increase the risk of CVD. Health self-assessment is crucial for early detection and management of health issues and early lifestyle intervention for better personalised health management. This study aims to determine the self-assessment of INTERHEART risk classification among the middle-aged community in Malaysia. Method: Local community members aged 40-60 years and who are currently residing in Malaysia were recruited via non-randomised sampling. Sociodemographic characteristics and dietary pattern related to salt, fibre, fat (deep fried/snacks), poultry/meat intakes, and other cardiovascular risk factors (waist-hip ratio, medical history related to diabetes/hypertension, history/exposure of tobacco use, psychosocial status, and level of physical activity) were assessed; INTERHEART risk scores were then computed and stratified into low, medium and high risks. Results: Approximately 45% (n = 273/602) of middle-aged respondents in Malaysia are at moderate-to-high risk of cardiovascular events, with men being more likely to develop CVD compared to women. The results of the survey indicated that poultry/meat intake (61%), physical inactivity (59%), and second-hand smoke (SHS) exposure (54%) are the most prevalent risk factors among the respondents. One-third of the respondents consumed excessive salty food and deep fried foods/snacks/fast food, and only one-third of them consumed vegetables/fruits at a recommended level. It is worrying that about a quarter of the respondents felt several periodical/permanent stresses and even felt sad/blue/depressed for two weeks or more in a row. Males, labour workers, and those with lower educational levels are more likely to develop CVD events. Conclusions: This study found that 45% of the middle-aged respondents were having moderate-to-high risk for cardiovascular events with multiple risk factors related to unhealthy lifestyle habits and environmental factors. In addition to non-modifiable factors such as gender and age, sociodemographic factors, i.e., educational level and occupation, are equally important factors to determine CVD risk. Overall, the findings of this study emphasize the clinical relevance of assessing multiple factors in the determination of CVD risks for early prevention and management of cardiovascular diseases.

Low-thermal-budget synthesis of monolayer molybdenum disulfide for silicon back-end-of-line integration on a 200 mm platform.

Two-dimensional (2D) materials are promising candidates for future electronics due to their excellent electrical and photonic properties. Although promising results on the wafer-scale synthesis (≤150 mm diameter) of monolayer molybdenum disulfide (MoS2) have already been reported, the high-quality synthesis of 2D materials on wafers of 200 mm or larger, which are typically used in commercial silicon foundries, remains difficult. The back-end-of-line (BEOL) integration of directly grown 2D materials on silicon complementary metal-oxide-semiconductor (CMOS) circuits is also unavailable due to the high thermal budget required, which far exceeds the limits of silicon BEOL integration (<400 °C). This high temperature forces the use of challenging transfer processes, which tend to introduce defects and contamination to both the 2D materials and the BEOL circuits. Here we report a low-thermal-budget synthesis method (growth temperature < 300 °C, growth time ≤ 60 min) for monolayer MoS2 films, which enables the 2D material to be synthesized at a temperature below the precursor decomposition temperature and grown directly on silicon CMOS circuits without requiring any transfer process. We designed a metal-organic chemical vapour deposition reactor to separate the low-temperature growth region from the high-temperature chalcogenide-precursor-decomposition region. We obtain monolayer MoS2 with electrical uniformity on 200 mm wafers, as well as a high material quality with an electron mobility of ~35.9 cm2 V-1 s-1. Finally, we demonstrate a silicon-CMOS-compatible BEOL fabrication process flow for MoS2 transistors; the performance of these silicon devices shows negligible degradation (current variation < 0.5%, threshold voltage shift < 20 mV). We believe that this is an important step towards monolithic 3D integration for future electronics.

Variations and its driven factors of anthropogenic nitrogen loads in the Yangtze River Economic Belt during 2000-2019.

Since the millennium, China has economically taken off with rapid urbanization, and anthropogenic nitrogen emission intensity has undergone remarkable changes. To better understand the impact of urbanization on anthropogenic nitrogen, this study calculated the spatio-temporal heterogeneity of anthropogenic nitrogen in the Yangtze River Economic Belt (YREB) since 2000, based on the estimation, using obstacle analysis to quantify the driving of industry and agriculture on N growth and using the gray model to analyze the impact of urbanization on N changes. Additionally, using the environmental pressure model to predict the future N load. The results indicated N load in the YREB increased rapidly from 21.4 Tg in 2001 to a peak of 24.5 Tg in 2012 and then decreased to 22.2 Tg in 2019. Although N flux gradually increased from the west to the east of the YREB, the growth rate had an opposite trend with a negative growth in the eastern region. Hotspots are mainly concentrated in urban agglomerations, which contributed to ~ 60% N load of the YREB, and the YREB contributed to ~ 90% N load of the Yangtze River Basin. Obstacle degree scores indicated wastewater was a major industrial driver of N growth before 2010, and then became waste gas; increased mechanization and fertilizer control effectively reduced nitrogen emissions during agricultural development. The gray analysis of urbanization indicated urban population, industry, and services had the strongest correlation with N load changes. Scenario simulations suggest N loads of the YREB remain at a high level by 2030; however, there are still opportunities to effectively control N growth through high technological innovation and reducing the proportion of industry under an enormous population. This research contributes to a better understanding of the impact of urbanization on anthropogenic nitrogen and helps developing countries to precisely control nitrogen hotspots and sources.

Human Brain Organoids as an In Vitro Model System of Viral Infectious Diseases.

Brain organoids, or brainoids, have shown great promise in the study of central nervous system (CNS) infection. Modeling Zika virus (ZIKV) infection in brain organoids may help elucidate the relationship between ZIKV infection and microcephaly. Brain organoids have been used to study the pathogenesis of SARS-CoV-2, human immunodeficiency virus (HIV), HSV-1, and other viral infections of the CNS. In this review, we summarize the advances in the development of viral infection models in brain organoids and their potential application for exploring mechanisms of viral infections of the CNS and in new drug development. The existing limitations are further discussed and the prospects for the development and application of brain organs are prospected.

Assessment and control of the impermeability of graphene for atomically thin membranes and barriers.

Two-dimensional materials such as graphene offer fundamentally transformative opportunities in membrane separations and as impermeable barriers, but the lack of facile methods to assess and control its 'impermeability' critically limits progress. Here we show that a simple etch of the growth catalyst (Cu) through defects in monolayer graphene synthesized by chemical vapor deposition (CVD) can be used to effectively assess graphene quality for membrane/barrier applications. Using feedback from the method to tune synthesis, we realize graphene with nearly no nanometer-scale defects as assessed by diffusion measurements, in contrast to commercially available graphene that is largely optimized for electronic applications. Interestingly, we observe clear evidence of leakage through larger defects associated with wrinkles in graphene, which are selectively sealed to realize centimeter-scale atomically thin barriers exhibiting <2% mass transport compared to the graphene support. Our work provides a facile method to assess and control the 'impermeability' of graphene and shows that future work should be directed towards the control of leakage associated with wrinkles.

Assessment of exhaust emissions from carbon nanotube production and particle collection by sampling filters.

UNLABELLED: This study performed a workplace evaluation of emission control using available air sampling filters and characterized the emitted particles captured in filters. Characterized particles were contained in the exhaust gas released from carbon nanotube (CNT) synthesis using chemical vapor deposition (CVD). Emitted nanoparticles were collected on grids to be analyzed using transmission electron microscopy (TEM). CNT clusters in the exhaust gas were collected on filters for investigation. Three types of filters, including Nalgene surfactant-free cellulose acetate (SFCA), Pall A/E glass fiber, and Whatman QMA quartz filters, were evaluated as emission control measures, and particles deposited in the filters were characterized using scanning transmission electron microscopy (STEM) to further understand the nature of particles emitted from this CNT production. STEM analysis for collected particles on filters found that particles deposited on filter fibers had a similar morphology on all three filters, that is, hydrophobic agglomerates forming circular beaded clusters on hydrophilic filter fibers on the collecting side of the filter. CNT agglomerates were found trapped underneath the filter surface. The particle agglomerates consisted mostly of elemental carbon regardless of the shapes. Most particles were trapped in filters and no particles were found in the exhaust downstream from A/E and quartz filters, while a few nanometer-sized and submicrometer-sized individual particles and filament agglomerates were found downstream from the SFCA filter. The number concentration of particles with diameters from 5 nm to 20 µm was measured while collecting particles on grids at the exhaust piping. Total number concentration was reduced from an average of 88,500 to 700 particle/cm(3) for the lowest found for all filters used. Overall, the quartz filter showed the most consistent and highest particle reduction control, and exhaust particles containing nanotubes were successfully collected and trapped inside this filter. IMPLICATIONS: As concern for the toxicity of engineered nanoparticles grows, there is a need to characterize emission from carbon nanotube synthesis processes and to investigate methods to prevent their environmental release. At this time, the particles emitted from synthesis were not well characterized when collected on filters, and limited information was available about filter performance to such emission. This field study used readily available sampling filters to collect nanoparticles from the exhaust gas of a carbon nanotube furnace. New agglomerates were found on filters from such emitted particles, and the performance of using the filters studied was encouraging in terms of capturing emissions from carbon nanotube synthesis.

A facile methodology for the production of in situ inorganic nanowire hydrogels/aerogels.

Creating inorganic nanowire hydrogels/aerogels using various materials and inexpensive means remains an outstanding challenge despite their importance for many applications. Here, we present a facile methodology to enable highly porous inorganic nanowire hydrogel/aerogel production on a large scale and at low cost. The hydrogels/aerogels are obtained from in situ hydrothermal synthesis of one-dimensional (1D) nanowires that directly form a cross-linking network during the synthesis process. Such a method not only offers great simplicity but also allows the interconnecting nanowires to have much longer length. The longer length offers aerogels with remarkable porosity and surface area extremely low densities (as low as 2.9 mg/cm(3)), are mechanically robust, and can have superelasticity by tuning the synthesis conditions. The nanowires in the hydrogels/aerogels serve both as structural support and active sites, for example, for catalysis or absorption. In this work, we have found that the as-grown hydrogels can be used directly as water filters to remove pollutants such as heavy metal ions and toxic organic contents. Our studies indicate that this method for nanowire hydrogels/aerogels production is not only economical but greatly augmented their applications in environmental, catalysis, sensing, absorption, energy storage, and beyond.

Dual-basis second-order Moller-Plesset perturbation theory: A reduced-cost reference for correlation calculations.

The resolution-of-the-identity (RI) approximation has placed the onus of the cost of a second-order Moller-Plesset (MP2) calculation on the underlying self-consistent field (SCF) calculation for many moderately sized molecules. A dual-basis approach to the SCF calculation, based on previous methods demonstrated for density functional theory, is combined with RI-MP2 calculations, and small basis subsets for cc-pVTZ, cc-pVQZ, and 6-311++G(3df,3pd) are presented. These subsets provide time savings of greater than 90%, with negligible errors in absolute and relative energies, compared to the associated full-basis counterpart. The method is tested with a series of rotational barriers, relative conformational energies of alanine tetrapeptides, as well as the full G3/99 molecular set. RI-MP2 calculations on alanine octapeptides (40 heavy atoms, 3460 basis functions), using cc-pVQZ, are presented. Results improve upon previous methods that diagonalize the virtual space separately.

Estradiol control of expression and levels of estradiol-binding proteins in the medial preoptic area, medial hypothalamus and pituitary.

The brains of mammals have at least three estradiol-binding proteins: estradiol receptor-alpha (ERalpha), ERbeta, and sex hormone-binding globulin (SHBG). In this study we compare the effects of estradiol treatment on the expression of mRNA for these three estradiol-binding proteins in two reproductively important brain areas, the medial preoptic area-anterior hypothalamus (MPOA-AH) and medial hypothalamus (MH) as well as in the hippocampus in ovariectomized rats, using the reverse transcriptase-polymerase chain reaction (RT-PCR). We also used surface-enhanced laser desorption ionization time of flight (SELDI-TOF) mass spectrometry (MS) to analyze the effects of estradiol in ovariectomized rats on SHBG levels in the MPOA-MH as well as the neurohypophysis. In vivo estradiol treatment in ovariectomized rats eliminated or significantly reduced expression of all three estradiol-binding proteins in both the MPOA-AH and MH. This change in ERalpha, ERbeta, and SHBG expression did not occur in the hippocampus. Both Northern blot and DNA sequence analysis confirmed the results of the RT-PCR for SHBG. SELDI-TOF MS analysis demonstrated that in vivo estradiol treatments resulted in dramatically decreased levels of SHBG in the hypothalamus and that a reduction in SHBG mRNA by estradiol treatment also resulted in a reduction in SHBG protein levels. Estradiol treatment also eliminated detectable SHBG from the neurohypophysis, suggesting that estradiol controls SHBG levels in this release site. That in vivo estradiol treatments had the same inhibitory effects on mRNA levels for SHBG and both ERs suggests similar translational control mechanisms for all three steroid-binding proteins in the brain. That estradiol treatments also reduced pituitary SHBG suggests that such treatment releases SHBG from the neurohypophysis.