Given the medical and social significance of Helicobacter pylori infection, timely and reliable diagnosis of the disease is required. The traditional invasive and non-invasive conventional diagnostic ...techniques have several limitations. Recently, opportunities for new diagnostic methods have appeared based on the recent advance in the study of H. pylori outer membrane proteins and their identified receptors. In the present study we assess the way in which outer membrane protein–cell receptor reactions are applicable in establishing a reliable diagnosis. Herein, as well as in other previous studies of ours, we explore the reliability of the binding reaction between the best characterized H. pylori adhesin BabA and its receptor, the blood antigen Lesup.b. For the purpose we developed surface plasmon resonance (SPR) and double resonance long period grating (DR LPG) biosensors based on the BabA–Lesup.b binding reaction for diagnosing H. pylori infection. In SPR detection, the sensitivity was estimated at 3000 CFU/mL—a much higher sensitivity than that of the RUT test. The DR LPG biosensor proved to be superior in terms of accuracy and sensitivity—concentrations as low as 10sup.2 CFU/mL were detected.
Ethane dehydroaromatization (EDA) is a potentially attractive process for converting ethane to valuable aromatics such as benzene, toluene, and xylene (BTX). In this study, a Ptsub.3Mn/SiOsub.2 + ...ZSM-5 bifunctional catalyst was used to investigate the effect of dehydrogenation and the Brønsted acid catalyst ratio, hydrogen partial pressure, and reaction temperature on the product distributions for EDA. Ptsub.3Mn/SiOsub.2 + ZSM-5 with a 1/1 weight ratio showed the highest ethane conversion rate and BTX formation rate. Ethylene is initially formed by dehydrogenation by the Ptsub.3Mn catalyst, which undergoes secondary reactions on ZSM-5, forming Csub.3+ reaction intermediates. The latter form final products of CHsub.4 and BTX. At conversions from 15 to 30%, the BTX selectivities are 82–90%. For all bifunctional catalysts, the ethane conversion significantly exceeds the ethane–ethylene equilibrium conversion due to reaction to secondary products. Low Hsub.2 partial pressures did not significantly alter the product selectivity or conversion. However, higher Hsub.2 partial pressures resulted in increased methane and decreased BTX selectivity. The excess hydrogen saturated the olefin intermediates to form alkanes, which produced methane by monomolecular cracking on ZSM-5. With an increasing reaction temperature from 550 °C to 650 °C, the benzene selectivity increased, while the highest BTX selectivity was obtained at 600 to 650 °C.
Globally, nearly 3 billion people rely on solid fuels for cooking and heating, the vast majority residing in low- and middle-income countries (LMICs). The resulting household air pollution (HAP) is a ...leading environmental risk factor, accounting for an estimated 1.6 million premature deaths annually. Previous interventions of cleaner stoves have often failed to reduce exposure to levels that produce meaningful health improvements. There have been no multicountry field trials with liquefied petroleum gas (LPG) stoves, likely the cleanest scalable intervention.
This paper describes the design and methods of an ongoing randomized controlled trial (RCT) of LPG stove and fuel distribution in 3,200 households in 4 LMICs (India, Guatemala, Peru, and Rwanda).
We are enrolling 800 pregnant women at each of the 4 international research centers from households using biomass fuels. We are randomly assigning households to receive LPG stoves, an 18-month supply of free LPG, and behavioral reinforcements to the control arm. The mother is being followed along with her child until the child is 1 year old. Older adult women (40 to
of age) living in the same households are also enrolled and followed during the same period. Primary health outcomes are low birth weight, severe pneumonia incidence, stunting in the child, and high blood pressure (BP) in the older adult woman. Secondary health outcomes are also being assessed. We are assessing stove and fuel use, conducting repeated personal and kitchen exposure assessments of fine particulate matter with aerodynamic diameter
(
), carbon monoxide (CO), and black carbon (BC), and collecting dried blood spots (DBS) and urinary samples for biomarker analysis. Enrollment and data collection began in May 2018 and will continue through August 2021. The trial is registered with ClinicalTrials.gov (NCT02944682).
This study will provide evidence to inform national and global policies on scaling up LPG stove use among vulnerable populations. https://doi.org/10.1289/EHP6407.
The effect of natural gas use on indoor radon concentrations was studied in the dwelling of two cities in Cyprus using an AlphaGUARD radon detector. The radioactivity concentration of .sup.222Rn ...capsule natural gas samples were measured, and the contribution of natural gas consumption to generate indoor .sup.222Rn in residential houses was calculated. The average values of the indoor .sup.222Rn concentrations were found between 42.16 and 146.47 Bq m.sup.-3 in CNG and LPG samples, respectively. The obtained annual effective dose and excess lifetime cancer risk (ELCR) have been compared with the world average values specified by the WHO and UNSCEAR reports.
Given the growing severity of particulate matter (PM) and greenhouse gas pollution, the Korean government recently began supporting the use of eco-friendly vehicles, such as electric vehicles and ...hydrogen fuel cell vehicles. However, the uptake of these vehicles has been slower than anticipated because of the high purchase price and lack of infrastructure. Therefore, the Korean government has eased restrictions on liquefied petroleum gas (LPG) vehicles to encourage the vast majority of consumers to purchase LPG vehicles, expecting that they will serve as a stepping stone to switch from internal combustion engine vehicles to their eco-friendly counterparts. However, there have been only a few studies on consumer preferences for LPG vehicles in consideration of this amendment. To analyze consumer preferences for all fuel types, including LPG, this study used a discrete choice experiment combined with a reference-dependent model. The results showed a loss aversion tendency and asymmetric preferences among consumers with regard to vehicle choice. Based on these results, a simulation analysis was conducted to predict the future market share and PM pollution level. The findings indicated that the government's LPG vehicle deregulation policy could achieve positive PM reduction effects in the short term but none in the long term.
•Forecast a market share by fuel type and derive PM emission reduction level.•Use the discrete choice experiments and a reference-dependent model.•Find loss aversion parameter and asymmetric preference for vehicle attributes.•The consumers are reluctant to switch to eco-friendly vehicles and compact cars.•LPG vehicles have a positive effect on PM reduction only in the short term.
Background The Household Air Pollution Intervention Network (HAPIN) trial aims to assess health benefits of a liquefied petroleum gas (LPG) cookfuel and stove intervention among women and children ...across four low- and middle-income countries (LMICs). We measured exposure contrasts for women, achievable under alternative conditions of biomass or LPG cookfuel use, at potential HAPIN field sites in India, to aid in site selection for the main trial. Methods We recruited participants from potential field sites within Villupuram and Nagapattinam districts in Tamil Nadu, India, that were identified during a feasibility assessment. We performed. (i) cross-sectional measurements on women (N = 79) using either biomass or LPG as their primary cookfuel and (ii) before-and-after measurements on pregnant women (N = 41), once at baseline while using biomass fuel and twice - at 1 and 2 months - after installation of an LPG stove and free fuel intervention. We involved participants to co-design clothing and instrument stands for personal and area sampling. We measured 24 or 48-h personal exposures and kitchen and ambient concentrations of fine particulate matter (PM2.5) using gravimetric samplers. Results In the cross-sectional analysis, median (interquartile range, IQR) kitchen PM2.5 concentrations in biomass and LPG using homes were 134 mug/m3 IQR:71-258 and 27 mug/m3 IQR:20-47, while corresponding personal exposures were 75 mug/m3 IQR:55-104 and 36 mug/m3 IQR:26-46, respectively. In before-and-after analysis, median 48-h personal exposures for pregnant women were 72 mug/m3 IQR:49-127 at baseline and 25 mug/m3 IQR:18-35 after the LPG intervention, with a sustained reduction of 93% in mean kitchen PM2.5 concentrations and 78% in mean personal PM2.5 exposures over the 2 month intervention period. Median ambient concentrations were 23 mug/m3 IQR:19-27). Participant feedback was critical in designing clothing and instrument stands that ensured high compliance. Conclusions An LPG stove and fuel intervention in the candidate HAPIN trial field sites in India was deemed suitable for achieving health-relevant exposure reductions. Ambient concentrations indicated limited contributions from other sources. Study results provide critical inputs for the HAPIN trial site selection in India, while also contributing new information on HAP exposures in relation to LPG interventions and among pregnant women in LMICs. Trial registration ClinicalTrials.Gov. NCT02944682; Prospectively registered on October 17, 2016. Keywords: HAPIN trial, LPG intervention, Household air pollution, PM.sub.2.5, Personal exposures, Pregnant women, India
Probiotic fermentation of plant-based materials can lead to the generation of various bioactive substances via bacterial metabolites and the biotransformation of phenolic compounds. We compared the ...metabolic differences between fermentation by Limosilactobacillus fermentum KCTC15072BP (LFG) and fermentation by Lactiplantibacillus plantarum KGMB00831 (LPG) in guava leaf extract (0%, 0.5%, and 2% (w/v))-supplemented medium via non-targeted metabolite profiling. By performing multivariate statistical analysis and comparing the different guava leaf extract groups, 21 guava-derived and 30 bacterial metabolites were identified. The contents of guava-derived glucogallin, gallic acid, and sugar alcohols were significantly higher in LFG than they were in LPG. Similarly, significantly higher contents of guava-derived pyrogallol, vanillic acid, naringenin, phloretin, and aromatic amino acid catabolites were obtained with LPG than with LFG. LFG led to significantly higher antioxidant activities than LPG, while LPG led to significantly higher antiglycation activity than LFG. Interestingly, the fermentation-induced increase in the guava-leaf-extract-supplemented group was significantly higher than that in the control group. Thus, the increased bioactivity induced by guava fermentation with the Lactobacillaceae strain may be influenced by the synergistic effects between microbial metabolites and plant-derived compounds. Overall, examining the metabolic changes in plant-based food fermentation by differentiating the origin of metabolites provides a better understanding of food fermentation.
•The injection quantity and injection rate increased as the fuel density increased.•The spray penetration was longer in the order of LPG fuels > gasoline > n-heptane.•The nozzle tip wetting was wider ...in the order of LPG fuels > n-heptane > gasoline.
Unlike the conventional liquid phase LPG injection (LPLI) system, an LPG direct injection (LPDI) system directly injects fuel into the combustion chamber, so the temperature inside the combustion chamber decreases due to the latent heat of vaporization of the fuel. Therefore, the direct injection (DI) system has the advantage of increasing fuel efficiency and power performance. However, a classic problem of the DI system is that a large amount of particle numbers (PNs) is emitted due to the nozzle tip wetting, which is affected by the spray characteristics related to the fuel properties. Therefore, research on nozzle tip wetting using an LPDI injector is needed. The purpose of this study is to investigate the macroscopic spray characteristics of four test fuels: n-heptane, gasoline, LPG winter, and LPG summer, using Mie scattering visualization, Schlieren visualization, and nozzle tip wetting using a long-distance microscope (LDM). The experiments were conducted using a three-hole LPDI injector with a step hole. In the comparison of n-heptane, gasoline, and the LPG fuels, the vapor pressure of the test fuels was high, in the order of LPG winter > LPG summer > gasoline > n-heptane. In addition, the surface tension of the test fuels was low, in the order of LPG winter < LPG summer < n-heptane < gasoline. The results revealed that the spray penetration of the LPG fuels was longer than that of n-heptane and gasoline because of flash boiling. Also, by comparing the nozzle tip wetting of these fuels, the wet area was wider in the order of LPG winter > LPG summer > n-heptane > gasoline.
•The LBV of NH3/C3H8/air was measured at normal and elevated temperatures.•Five NH3 kinetic models were validated against the experimental data.•Five blending laws for LBV were compared.•Effect of ...NH3 on several parameters of NH3/C3H8/air was analyzed.•The effect of NH3 substitution on the emission of NO, CO and CO2 was analyzed.
Propane (C3H8) is the major component of liquefied petroleum gas, the combustion of C3H8 and ammonia (NH3) should be concerned. However, there is a scarcity of experimental data on NH3/C3H8/air mixtures to validate the kinetic models, especially at elevated pressures. This work aims to provide some new laminar burning velocity data and investigate the premixed combustion characteristics of NH3/C3H8/air mixtures in detail. The measurement was performed at various equivalence ratios (ϕ = 0.6–1.4), ammonia ratios (α = 20 %, 50 %, 80 %), and initial pressures (P0 = 0.1–0.5 MPa). Besides, five kinetic models were compared against the experimental data, the optimal performing model was used for numerical simulation. The results show that when the mole fraction of C3H8 in fuels is 50 %, the peak laminar burning velocity is about 28.5 cm/s. And the peak value decreases to 19.0 cm/s when the initial pressure rises to 0.5 MPa. The burned gas Markstein length decreases with the increase of equivalence ratio mainly due to the remarkable effect of the effective Lewis number, and it also decreases with the increase of initial pressure because of the decreasing flame thickness. C3H8 promotes the combustion intensity of NH3, which is reflected in the enhancement of flame temperature and radical pool, but C3H8 has no obvious effect on the mixture heating value of the NH3/C3H8/air mixtures. NH3 substituting can effectively reduce CO and CO2 emissions, and the reduction effect is more significant under high NH3 mole fraction conditions.
Fine particulate matter (PM2.5) exposure has been linked to diverse human health impacts. Little is known about the potential heterogeneous impacts of PM2.5 generated from different indoor fuel ...sources and how exposure differs between personal and indoor environments. Therefore, we used PM2.5 collected by one stationary sampler in a kitchen and personal samplers (female and male participants), in homes (n = 24) in Kheri, India, that used either biomass or liquified petroleum gas (LPG) as primary fuel sources. PM2.5 samples (pooled by fuel type and monitor placement) were analyzed for oxidative potential and chemical composition, including elements and 125 organic compounds. Zebrafish (Danio rerio) embryos were acutely exposed to varying concentrations of PM2.5 and behavioral analyses were conducted. We found relatively high PM2.5 concentrations (5–15 times above World Health Organization daily exposure guidelines) and varied human health-related chemical composition based on fuel type and monitor placement (up to 15% carcinogenic polycyclic aromatic hydrocarbon composition). Altered biological responses, including changes to mortality, morphology, and behavior, were elicited by exposure to all sample types. These findings reveal that although LPG is generally ranked the least harmful compared to biomass fuels, chemical characteristics and biological impacts were still present, highlighting the need for further research in determining the safety of indoor fuel sources.
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