Identification of organic constituents on atmospheric particulate matter in the East Asian background air of free troposphere by GC×GC-TOFMS.

The presence of organic compounds on the particulate matter (PM) or aerosols can arise from the condensation of gaseous organic compounds on the existing aerosols, or from organic precursors to form secondary organic aerosols (SOA) through photochemistry. The objective of this study is to characterize organic constituents on aerosols relevant to their emission sources and the key compounds revealing the evolution of aerosols with the use of a novel analytical technique. A time-of-flight mass spectrometry (TOFMS) coupled with comprehensive two-dimensional gas chromatography (GC×GC) was developed using a flow type of modulator instead of a thermal type as a prelude to field applications without the need for cryogen.

Assessing the impact of specific PM-Bound metallic elements on asthma emergency department visits: A case-crossover study in Taiwan.

Objectives: This study aims to assess the specific PM-bound metallic elements that contribute to asthma emergency department visits by using a case-crossover study design.

Methods: This study analyzed data from 11,410 asthma emergency department visits as case group and 22,820 non-asthma onset dates occurring one week and two weeks preceding the case day as controls from 2017 to 2020. PM monitoring data and 35 PM.

A numerical study of reducing the concentration of O and PM simultaneously in Taiwan.

Since the 24-hr PM (particle aerodynamic diameter less than 2.5 μm) concentration standard was regulated in Taiwan in 2012, the PM concentration has been decreasing year by year, but the ozone (O) concentration remains almost the same. In particular, the daily maximum 8-hr average O (MDA8 O) concentration frequently exceeds the standard.

Insights into aerosol chemical composition and optical properties at Lulin Atmospheric Background Station (2862 m asl) during two contrasting seasons.

Continental outflows from peninsular Southeast Asia and East Asia dominate the widespread dispersal of air pollutants over subtropical western North Pacific during spring and autumn, respectively. This study analyses the chemical composition and optical properties of PM aerosols during autumn and spring at a representative high-altitude site, viz., Lulin Atmospheric Background Station (23.

Isotopic signatures and source apportionment of Pb in ambient PM.

Particulate lead (Pb) is a primary air pollutant that affects society because of its health impacts. This study investigates the source sectors of Pb associated with ambient fine particulate matter (PM) over central-western Taiwan (CWT) with new constraints on the Pb-isotopic composition. We demonstrate that the contribution of coal-fired facilities is overwhelming, which is estimated to reach 35 ± 16% in the summertime and is enhanced to 57 ± 24% during the winter monsoon seasons.

Expression of the AHPND Toxins PirA and PirB Is Regulated by Components of the Quorum Sensing (QS) System.

Acute hepatopancreatic necrosis disease (AHPND) in shrimp is caused by strains that harbor a pVA1-like plasmid containing the and genes. It is also known that the production of the PirA and PirB proteins, which are the key factors that drive the observed symptoms of AHPND, can be influenced by environmental conditions and that this leads to changes in the virulence of the bacteria. However, to our knowledge, the mechanisms involved in regulating the expression of the / genes have not previously been investigated.

Humic-like substances (HULIS) in springtime aerosols at a high-altitude background station in the western North Pacific: Source attribution, abundance, and light-absorption.

Atmospheric humic-like substances (HULIS) are important components of biomass-burning (BB) emissions and highly associated with light-absorbing organic aerosols (often referred to as brown carbon). This study highlights the importance of BB-emitted HULIS aerosols in peninsular Southeast Asian outflow to the subtropical western North Pacific. We determined various key light-absorbing characteristics of HULIS i.

Brown carbon light absorption over an urban environment in northern peninsular Southeast Asia.

Light-absorbing organic carbon (or brown carbon, BrC) has been recognized as a critical driver in regional-to-global climate change on account of its significant contribution to light absorption. BrC sources vary from primary combustion processes (burning of biomass, biofuel, and fossil fuel) to secondary formation in the atmosphere. This paper investigated the light-absorbing properties of BrC such as site-specific mass absorption cross-section (MAC), absorption Ångström exponent (AAE), and the absorbing component of the refractive index (k) by using light absorption measurements from a 7-wavelength aethalometer over an urban environment of Chiang Mai, Thailand in northern peninsular Southeast Asia (PSEA), from March to April 2016.

A Sleep Apnea Detection System Based on a One-Dimensional Deep Convolution Neural Network Model Using Single-Lead Electrocardiogram.

Many works in recent years have been focused on developing a portable and less expensive system for diagnosing patients with obstructive sleep apnea (OSA), instead of using the inconvenient and expensive polysomnography (PSG). This study proposes a sleep apnea detection system based on a one-dimensional (1D) deep convolutional neural network (CNN) model using the single-lead 1D electrocardiogram (ECG) signals. The proposed CNN model consists of 10 identical CNN-based feature extraction layers, a flattened layer, 4 identical classification layers mainly composed of fully connected networks, and a softmax classification layer.

Black carbon over an urban atmosphere in northern peninsular Southeast Asia: Characteristics, source apportionment, and associated health risks.

Black carbon (BC) has been demonstrated to pose significant negative impacts on climate and human health. Equivalent BC (EBC) measurements were conducted using a 7-wavelength aethalometer, from March to May 2016, over an urban atmosphere, viz., Chiang Mai (98.

Adaptation to host in Vibrio vulnificus, a zoonotic pathogen that causes septicemia in fish and humans.

Vibrio vulnificus is a siderophilic pathogen spreading due to global warming. The zoonotic strains constitute a clonal-complex related to fish farms that are distributed worldwide. In this study, we applied a transcriptomic and single gene approach and discover that the zoonotic strains bypassed the iron requirement of the species thanks to the acquisition of two iron-regulated outer membrane proteins (IROMPs) involved in resistance to fish innate immunity.

Quantifying PM from long-range transport and local pollution in Taiwan during winter monsoon: An efficient estimation method.

From autumn to the following spring, annually, the northeast monsoon transports PM (particles less than 2.5 μm in aerodynamic diameter) from the Asian continent to downstream areas. Naturally, this triggered a question: What are the contributions of PM from long-range transport (LRT) and local pollution (LP) at any downstream location? To answer that question, the present study developed an economical and efficient method that can easily estimate the contribution of PM from LRT (LRT-PM) and PM from LP (LP-PM).

MARTX Toxin in the Zoonotic Serovar of Triggers an Early Cytokine Storm in Mice.

biotype 2-serovar E is a zoonotic clonal complex that can cause death by sepsis in humans and fish. Unlike other biotypes, Bt2 produces a unique type of MARTX (Multifunctional-Autoprocessive-Repeats-in-Toxin; RtxA1), which is encoded by a gene duplicated in the pVvBt2 plasmid and chromosome II. In this work, we analyzed the activity of this toxin and its role in human sepsis by performing , and assays.

Long-term monitoring of atmospheric PCDD/Fs at Mount Lulin during spring season: PCDD/F source apportionment through a simultaneous measurement in Southeast Asia.

A long term assessment of atmospheric polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) at Mt. Lulin, located in center of Taiwan was carried out from 2008 to 2013 (n = 81) assuming Mt. Lulin to be background area.

Iron and Fur in the life cycle of the zoonotic pathogen Vibrio vulnificus.

In this study, we aimed to analyze the global response to iron in the broad-range host pathogen Vibrio vulnificus under the hypothesis that iron is one of the main signals triggering survival mechanisms both inside and outside its hosts. To this end, we selected a strain from the main zoonotic clonal-complex, obtained a mutant in the ferric-uptake-regulator (Fur), and analyzed their transcriptomic profiles in both iron-excess and iron-poor conditions by using a strain-specific microarray platform. Among the genes differentially expressed, we identified around 250 as putatively involved in virulence and survival-related mechanisms.

Apportionment of the sources of high fine particulate matter concentration events in a developing aerotropolis in Taoyuan, Taiwan.

To investigate the characteristics and contributions of the sources of fine particulate matter with a size of up to 2.5 μm (PM2.5) during the period when pollution events could easily occur in Taoyuan aerotropolis, Taiwan, this study conducted sampling at three-day intervals from September 2014 to January 2015.

Pathogenesis of acute hepatopancreatic necrosis disease (AHPND) in shrimp.

Acute hepatopancreatic necrosis disease (AHPND), also called early mortality syndrome (EMS), is a recently emergent shrimp bacterial disease that has resulted in substantial economic losses since 2009. AHPND is known to be caused by strains of Vibrio parahaemolyticus that contain a unique virulence plasmid, but the pathology of the disease is still unclear. In this study, we show that AHPND-causing strains of V.

The Fish Pathogen Vibrio vulnificus Biotype 2: Epidemiology, Phylogeny, and Virulence Factors Involved in Warm-Water Vibriosis.

Vibrio vulnificus biotype 2 is the etiological agent of warm-water vibriosis, a disease that affects eels and other teleosts, especially in fish farms. Biotype 2 is polyphyletic and probably emerged from aquatic bacteria by acquisition of a transferable virulence plasmid that encodes resistance to innate immunity of eels and other teleosts. Interestingly, biotype 2 comprises a zoonotic clonal complex designated as serovar E that has extended worldwide.

Novel host-specific iron acquisition system in the zoonotic pathogen Vibrio vulnificus.

Vibrio vulnificus is a marine bacterium associated with human and fish (mainly farmed eels) diseases globally known as vibriosis. The ability to infect and overcome eel innate immunity relies on a virulence plasmid (pVvbt2) specific for biotype 2 (Bt2) strains. In the present study, we demonstrated that pVvbt2 encodes a host-specific iron acquisition system that depends on an outer membrane receptor for eel transferrin called Vep20.

Draft Genome Sequences of Four Strains of Vibrio parahaemolyticus, Three of Which Cause Early Mortality Syndrome/Acute Hepatopancreatic Necrosis Disease in Shrimp in China and Thailand.

We sequenced four Vibrio parahaemolyticus strains, three of which caused serious acute hepatopancreatic necrosis disease. Sequence analysis of the virulent strains revealed not only genes related to cholera toxin and the type IV pilus/type IV secretion system but also a unique, previously unreported, large extrachromosomal plasmid that encodes a homolog to the insecticidal Photorhabdus insect-related binary toxin PirAB.

Host-nonspecific iron acquisition systems and virulence in the zoonotic serovar of Vibrio vulnificus.

The zoonotic serovar of Vibrio vulnificus (known as biotype 2 serovar E) is the etiological agent of human and fish vibriosis. The aim of the present work was to discover the role of the vulnibactin- and hemin-dependent iron acquisition systems in the pathogenicity of this zoonotic serovar under the hypothesis that both are host-nonspecific virulence factors. To this end, we selected three genes for three outer membrane receptors (vuuA, a receptor for ferric vulnibactin, and hupA and hutR, two hemin receptors), obtained single and multiple mutants as well as complemented strains, and tested them in a series of in vitro and in vivo assays, using eels and mice as animal models.

Increasing emergency room visits for stroke by elevated levels of fine particulate constituents.

The associations between fine particulate matter (PM2.5) and stroke remain inconsistent. We conducted a time-series study to evaluate emergency room (ER) visits for ischemic and hemorrhagic strokes in relation to PM2.