Environmental Risk Factors for Talaromycosis Hospitalizations of HIV-Infected Patients in Guangzhou, China: Case Crossover Study

Talaromycosis is a fatal opportunistic infection prevalent in human immunodeficiency virus (HIV)-infected patients, previous studies suggest environmental humidity is associated with monthly talaromycosis hospitalizations of HIV-infected patients, but the acute risk factor remains uncertain. In this study, we evaluated the associations between talaromycosis hospitalizations of HIV-infected patients (n = 919) and environmental factors including meteorological variables and air pollutants at the event day (assumed “lag 0” since the exact infection date is hard to ascertain) and 1–7 days prior to event day (lag 1–lag 7) in conditional logistics regression models based on a case crossover design. We found that an interquartile range (IQR) increase in temperature at lag 0–lag 7 (odds ratio [OR] [95% CI] ranged from 1.748 [1.345–2.273] to 2.184 [1.672–2.854]), and an IQR increase in humidity at lag 0 (OR [95% CI] = 1.192 [1.052–1.350]), and lag 1 (OR [95% CI] = 1.199 [1.056–1.361]) were significantly associated with talaromycosis hospitalizations of HIV-infected patients. Besides, temperature was also a common predictor for talaromycosis in patients with co-infections including candidiasis (n = 386), Pneumocystis pneumonia (n = 183), pulmonary tuberculosis (n = 141), and chronic hepatitis (n = 158), while humidity was a specific risk factor for talaromycosis in patients with candidiasis, and an air pollutant, SO2, was a specific risk factor for talaromycosis in patients with Pneumocystis pneumonia. In an age stratified evaluation (cutoff = 50 years old), temperature was the only variable positively associated with talaromycosis in both younger and older patients. These findings broaden our understanding of the epidemiology and pathogenesis of talaromycosis in HIV-infected patients.

Research on improvement of moisture proof technology for JIS control cabinet of 220kV substation based on big data

The outdoor control cabinet of intelligent substation includes the central control cabinet and the intelligent control cabinet. The internal integrated circuits and electronic components are easily affected by the environmental humidity. Through the operation and maintenance data statistics, it is found that the existing heating and dehumidification system in the control cabinet can not fully meet the humidity requirements in the cabinet. In view of this problem, this paper analyzes the factors leading to the increase of humidity in the cabinet, puts forward the research on the improvement of moisture-proof technology of JIS control cabinet in 220kV substation based on big data. In an environment where the air temperature changes rapidly, the test data verify that the moisture-proof technology of JIS control cabinet in 220kV substation based on big data can effectively reduce the humidity in the intelligent control cabinet, and effectively ensure the safe operation of electronic equipment in the intelligent control cabinet.

Influence of water absorption on mechanical properties and glass transition temperatures of polyamide6/hexagonal boron nitride composites

PurposeThe absorption of moisture/water can affect the mechanical and thermal properties of polymers and polymer composites as many polymers, mainly polyamide thermoplastics, are sensitive to environmental humidity and can absorb a large amount of moisture. This paper investigates the effect of water molecules' absorption on mechanical and thermal properties of polyamide6/hexagonal boron nitride (PA6/h-BN) composites.Design/methodology/approachThe PA6/h-BN composites were exposed to an open environment and water for 15 days to analyse the effect of humidity/water molecules' absorption on mechanical and thermal properties. The tensile strength, hardness and impact strength of materials were measured and compared. The scanning electron microscopy (SEM), x-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses were utilized to see the influence of water absorption on microstructure, crystallinity and glass transition temperatures.FindingsAfter exposing materials to an open environment and water, the tensile strength and hardness were found to decline, while improvement in impact strength was noticed. SEM characterization revealed the formation of voids/pockets in water-immersed materials. DSC analysis revealed the loss in glass transition temperatures, and XRD analysis revealed the loss in crystallinity of water-immersed materials.Originality/valueEnvironmental conditions vary according to the geographical areas, and it varies in many countries throughout the year. Polyamides are sensitive to the environmental humidity and can absorb a large amount of moisture from the environment. It becomes necessary to test these materials in their original working conditions, and sometimes it is mandatory to see the effects of extreme environmental conditions on a component. In this article, efforts have been made to investigate the influence of extreme humidity/water conditions on thermo-mechanical properties of PA6/h-BN composites.

The ability of bumblebees Bombus terrestris (Hymenoptera: Apidae) to detect floral humidity is dependent upon environmental humidity

Flowers produce local humidity that is often greater than that of the surrounding environment, and studies have shown that insect pollinators may be able to use this humidity difference to locate and identify suitable flowers. However, environmental humidity is highly heterogeneous, and is likely to affect the detectability of floral humidity, potentially constraining the contexts in which it can be used as a salient communication pathway between plants and their pollinators. In this study, we use differential conditioning techniques on bumblebees Bombus terrestris audax (Harris) to explore the detectability of an elevated floral humidity signal when presented against different levels of environmental noise. Artificial flowers were constructed that could be either dry or humid, and individual bumblebees were presented with consistent rewards in either the humid or dry flowers presented in an environment with four levels of constant humidity, ranging from low (~20% RH) to highly saturated (~95% RH). Ability to learn was dependent upon both the rewarding flower type and the environment: the bumblebees were able to learn rewarding dry flowers in all environments, but their ability to learn humid rewarding flowers was dependent on the environmental humidity, and they were unable to learn humid rewarding flowers when the environment was highly saturated. This suggests that floral humidity might be masked from bumblebees in humid environments, suggesting that it may be a more useful signal to insect pollinators in arid environments.

The Influence of Formulation Components and Environmental Humidity on Spray-Dried Phage Powders for Treatment of Respiratory Infections Caused by Acinetobacter baumannii

The feasibility of using respirable bacteriophage (phage) powder to treat lung infections has been demonstrated in animal models and clinical studies. This work investigated the influence of formulation compositions and excipient concentrations on the aerosol performance and storage stability of phage powder. An anti-Acinetobacter baumannii phage vB_AbaM-IME-AB406 was incorporated into dry powders consisting of trehalose, mannitol and L-leucine for the first time. The phage stability upon the spray-drying process, room temperature storage and powder dispersion under different humidity conditions were assessed. In general, powders prepared with higher mannitol content (40% of the total solids) showed a lower degree of particle merging and no sense of stickiness during sample handling. These formulations also provided better storage stability of phage with no further titer loss after 1 month and <1 log titer loss in 6 months at high excipient concentration. Mannitol improved the dispersibility of phage powders, but the in vitro lung dose dropped sharply after exposure to high-humidity condition (65% RH) for formulations with 20% mannitol. While previously collected knowledge on phage powder preparation could be largely extended to formulate A. baumannii phage into inhalable dry powders, the environmental humidity may have great impacts on the stability and dispersion of phage; therefore, specific attention is required when optimizing phage powder formulations for global distribution.

The Effect of Humidity on the Atomization Process and Structure of Nanopowder Designed for Extinguishment

Increasingly, firefighting aerosols are being used to extinguish fires. It is assumed that the extinguishing mechanism involves breaking the chain of physicochemical reactions occurring during combustion by binding free radicals at ignition. The radicals are most likely formed from the transformation of water molecules, with the active surfaces of aerosol micro- or even nanoparticles. The aerosol extinguishing method is very effective even though it does not reduce oxygen levels in the air. In contrast to typical extinguishing powders, the aerosol leaves a trace amount of pollutants and, above all, does not adversely affect the environment by depleting the ozone layer and increasing greenhouse effects. Depending on how the firefighting generators are released, the aerosol can act locally or volumetrically, but depending on environmental conditions, its effectiveness can be variable. The article presents the influence of environmental humidity on the atomization of aerosol nanosize, which confirms the radical combustion mechanism. This paper presents the effect of environmental humidity on the atomization of aerosol superfine (nano) particles. The main focus was on the grain distribution and its effect on the surface activity of the FP-40C type firefighting aerosol. Changes in the characteristic parameters of the particle size distribution of RRSB (Rosin-Rammler-Sperling-Bennet) are presented.

Mechanochemical reactions of GaN-Al2O3 interface at the nanoasperity contact: Roles of crystallographic polarity and ambient humidity

Mechanochemical reactions of the GaN-Al2O3 interface offer a novel principle for scientific and technological merits in the micro-/nano-scale ultra-precision surface machining. In this work, the mechanochemical reactions on Ga- and N-faced GaN surfaces rubbed by the Al2O3 nanoasperity as a function of the environmental humidity were investigated. Experimental results indicate that the N-face exhibits much stronger mechanochemical removal over the relative humidity range of 20%–80% than the Ga-face. Increasing water molecules in environmental conditions significantly promotes the interfacial mechanochemical reactions and hence accelerates the atomic attrition on N-face. The hypothesized mechanism of the selective water-involved mechanochemical removal is associated with the dangling bond configuration, which affects the mechanically-stimulated chemical reactions via altering the activation energy barrier to form the bonding bridge across the sliding interface. These findings can enrich the understanding of the underlying mechanism of mechanochemical reactions at GaN-Al2O3 interface and a broad cognition for regulating the mechanochemical reactions widely existing in scientific and engineering applications.

Dry biocleaning of artwork: an innovative methodology for Cultural Heritage recovery?

An innovative methodology is proposed, based on applied biotechnology to the recovery of altered stonework: the “dry biocleaning“, which envisages the use of dehydrated microbial cells without the use of free water or gel-based matrices. This methodology can be particularly useful for the recovery of highly-ornamented stoneworks, which cannot be treated using the conventional cleaning techniques. The experimental plan included initial laboratory tests on Carrara marble samples, inoculated with dehydrated Saccharomyces cerevisiae yeast cells, followed by on-site tests performed on “Quattro Fontane” (The Four Fountains), a travertine monumental complex in Rome (Italy), on altered highly ornamented areas of about 1,000 cm2. The mechanism is based on the spontaneous re-hydration process due to the environmental humidity and on the metabolic fermentative activity of the yeast cells. Evaluation by physical-chemical analyses, after 18 hours of the biocleaning, confirmed a better removal of salts and pollutants, compared to both nebulization treatment and control tests (without cells). The new proposed on-site dry biocleaning technique, adopting viable yeast cells, represents a promising method that can be further investigated and optimized for recovering specific altered Cultural Heritage stoneworks.

Bacterial Spore-Based Hygromorphs: A Novel Active Material with Potential for Architectural Applications

This paper introduces a new active material which responds to changes in environmental humidity. There has been growing interest in active materials which are able to respond to their environment, creating dynamic architectural systems without the need for energy input or complex systems of sensors and actuators. A subset of these materials are hygromorphs, which respond to changes in relative humidity (RH) and wetting through shape change. Here, we introduce a novel hygromorphic material in the context of architectural design, composed of multiple monolayers of microbial spores of Bacillus subtilis and latex sheets. Methods of fabrication and testing for this new material are described, showing that small actuators made from this material demonstrate rapid, reversible and repeatable deflection in response to changes in RH. It is demonstrated that the hygromorphic actuators are able to lift at least 150% of their own mass. Investigations are also extended to understanding this new biomaterial in terms of meaningful work.