Levels Of Particles Research Articles

Comparison of Hollow Fiber and Flat Sheet Membranes for Removing TDS and Turbidity of Palm Oil Mill Effluent Wastewater

The most significant pollutant produced from agricultural industry in Kalimantan, Indonesia is Palm Oil Mill Effluent (POME). Due to the high levels of suspended particles and organic matter, POME has become a brownish color with high turbidity, color, chemical oxygen demand, and oil and grease content. To recycle the POME wastewater as clean water, these pollutants must be eliminated. In this study, we compare the effectiveness of hollow fiber (HF) and flat sheet (FS) membrane to remove total dissolved solid (TDS) and turbidity from POME with varied filtration pressure. HF and FS membrane were prepared from PVDF and nylon66 polymer, respectively. The PVDF HF membrane was modified using TiO2 and SBE (spent bleaching earth) to improve HF membrane properties to maintaining fouling. Meanwhile, FS membrane was added by pectin to increase the hydrophilic properties. Overall membrane’s morphology was determined by Scanning Electron Microscopy (SEM) to investigate the membrane structure. Both of HF and FS membrane were operated via ultrafiltration (UF) under cross flow system. The filtration pressures were varied at 1-3 bar and followed by flux and rejection evaluation. The results show both HF and FS membranes has stability flux. In addition, TDS rejection up to 25% while turbidity is excellent high over 95% for all membranes. The fabrication HF membrane has finger like-sponge structure and FS membrane exhibits sponge asymmetric structure. Overall, all membranes perform highest water flux (FS membrane) while highest rejection conducted by HF membrane for POME wastewater treatment.

Influence of Germicidal UV (222 nm) Lamps on Ozone, Ultrafine Particles, and Volatile Organic Compounds in Indoor Office Spaces.

Germicidal ultraviolet lamps with a peak emission at 222 nm (GUV222) are gaining prominence as a safe and effective solution to reduce disease transmission in occupied indoor environments. While previous studies have reported O3 production from GUV222, less is known about their impact on other indoor constituents affecting indoor air quality, especially in real occupied environments. In this study, the effects of GUV222 on the levels of ozone (O3), ultrafine particles (UFPs), and volatile organic compounds (VOCs) were investigated across multiple offices with varying occupancies. O3 from the GUV222 operation was observed to increase linearly (∼300 μg h-1 m-1) with a UV light path length from 0 to 3 m beyond which it stabilized. When applied in offices, the O3 production models based on continuous measurements revealed O3 production rates of 1040 ± 87 μg h-1. The resulting increases in steady-state concentrations of 5-21 μg m-3 were highly dependent on the number of office occupants. UFP production occurred during both unoccupied and occupied conditions but predominantly in newly renovated offices. Time-resolved measurements with a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) revealed clear alterations in office VOC concentrations. Unsurprisingly, O3 oxidation chemistry was observed, including monoterpene deprivation and 4-oxopentanal (4-OPA) production. But additionally, significant alterations from unidentified mechanisms occurred, causing increased levels of various PTR-TOF-MS signals including C2H5O2+ and C4H9+ hypothesized to arise from photoinduced formation or off-gassing during the GUV222 lamp operation.

Indoor Environmental Quality in Portuguese Office Buildings: Influencing Factors and Impact of an Intervention Study

Office workers spend a considerable part of their day at the workplace, making it vital to ensure proper indoor environmental quality (IEQ) conditions in office buildings. This work aimed to identify significant factors influencing IEQ and assess the effectiveness of an environmental intervention program, which included the introduction of indoor plants, carbon dioxide (CO2) sensors, ventilation, and printer relocation (source control), in six modern office buildings in improving IEQ. Thirty office spaces in Porto, Portugal, were randomly divided into intervention and control groups. Indoor air quality, thermal comfort, illuminance, and noise were monitored before and after a 14-day intervention implementation. Occupancy, natural ventilation, floor type, and cleaning time significantly influenced IEQ levels. Biophilic interventions appeared to decrease volatile organic compound concentrations by 30%. Installing CO2 sensors and optimizing ventilation strategies in an office that mainly relies on natural ventilation effectively improved air renewal and resulted in a 28% decrease in CO2 levels. The implementation of a source control intervention led to a decrease in ultrafine particle and ozone concentrations by 14% and 85%, respectively. However, an unexpected increase in airborne particle levels was detected. Overall, for a sample of offices that presented acceptable IEQ levels, the intervention program had only minor or inconsistent impacts. Offices with declared IEQ problems are prime candidates for further research to fully understand the potential of environmental interventions.

Understanding the role of soluble proteins and exosomes in non-invasive urine-based diagnosis of preeclampsia

Preeclampsia is a hypertensive disorder of pregnancy that can lead to stillbirth and preterm birth if not treated promptly. Currently, the diagnosis of preeclampsia relies on clinical symptoms such as hypertension and proteinuria, along with invasive blood tests. Here, we investigate the role of soluble proteins and exosomes in noninvasive diagnosing preeclampsia non-invasively using maternal urine and urine-derived exosomes. We quantified the levels of particles and the presence of TSG101 and CD63 in urine and urinary exosomes via the biologically intact exosome separation technology (BEST) platform. Then, we obtained higher levels of soluble proteins such as fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) from urine as it was than urinary exosomes. Compared to commercial blood tests, the sensitivity of the sFlt-1/PlGF ratio was found to be 4.0 times higher in urine tests and 1.5 times higher in tests utilizing urine-derived exosomes. Our findings offer promising possibilities for the early and non-invasive identification of high-risk individuals at risk of preeclampsia, allowing for comprehensive preventive management.

Airborne microplastic monitoring: Developing a simplified outdoor sampling approach using pollen monitoring equipment

A novel, yet simple, airborne microplastic (MP) sampling approach using global pollen monitoring equipment was applied to identify, characterise and quantify outdoor airborne MPs for the first time. Modification of Burkard spore trap tape adhesive provided particle capture and facilitated downstream spectroscopy analysis. 36 polymer types were identified from a total of 21 days sampling using Burkard spore traps at two locations (United Kingdom and South Africa). MPs were detected in 95 % of daily samples. Mean MP particle levels were 2.0 ± 0.9 MP m-3 (11 polymer types) in Hull (U.K.), during March, 2.9 ± 2.0 MP m-3 (16 types) in Hull in July, and 11.0 ± 5.7 MP m-3 (29 types) in Gqeberha, (S.A.) in August 2023. The most abundant polymer type was nylon (Gqeberha). The approach was compared with two passive sampling methods whereby 27 polymer types were identified and of these, 6 types were above the limit of quantification (LOQ), with poly(methacrolein:styrene) (PMA/PS) the most abundant. Irregularly shaped MPs < 100 µm in length were predominant from all sampling approaches. For the first time, airborne MPs were chemically characterised and quantified using volumetric pollen sampling equipment, representing a viable approach for future airborne MP monitoring.

Relationship of high-density lipoprotein subfractions and apolipoprotein A-I with fat in the pancreas.

To investigate the associations of high-density lipoprotein (HDL) subfractions and apolipoprotein A-I (apo A-I) with fat in the pancreas. A total of 170 individuals were studied. All participants underwent magnetic resonance imaging on a single 3.0-Tesla scanner to determine the presence/absence of fatty pancreas. HDL subfractions were measured using a commercially available lipoprotein subfractions testing system and classed as large, intermediate and small HDL. Both unadjusted and adjusted (accounting for demographics, anthropometrics, insulin resistance and other covariates) logistic regression models were built. Individuals with fatty pancreas had significantly lower circulating levels of the large HDL class and apo A-I. Every unit decrease in the large HDL class was associated with a 93% increase in the likelihood of fatty pancreas in the most adjusted model (P < .001). Every unit decrease in apo A-I was associated with a 45% increase in the likelihood of fatty pancreas in the most adjusted model (P = .012). The intermediate and small HDL classes were not significantly associated with fatty pancreas. Fat in the pancreas is inversely associated with the circulating levels of large HDL particles and apo A-I. Purposely designed studies are warranted to investigate the potential of fatty pancreas as an indicator of the risk of cardiovascular diseases.

Periodontitis adversely affects lipoprotein subfractions – results from the cohort study SHIP-TREND: Periodontitis adversely affects lipoprotein subfractions

AimWe aimed to investigate the medium-term associations of periodontitis and the number of missing teeth with serum lipoproteins and their plasma subfractions using follow-up data from the population-based Study of Health in Pomerania (SHIP-TREND). MethodsA total of 2,058 participants with 7-year follow-up data underwent periodontal examinations, serum lipid panel tests, and proton nuclear magnetic resonance (1H-NMR) spectroscopy of plasma lipoproteins and their subfractions. Generalized models with gamma distribution and loglink were used to analyze associations between periodontal variables and lipoproteins and their subfractions, adjusting for confounders using propensity score weighting. ResultsPeriodontal variables were consistently associated with elevated follow-up serum levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol levels. When plasma lipoprotein subfractions were evaluated, periodontal variables were associated with elevated levels of triglycerides and cholesterol-enriched apolipoprotein B-containing lipoprotein particles, particularly small dense low-density lipoprotein, very-low-density lipoprotein and intermediate density lipoprotein. In addition, altered high-density lipoprotein particle composition was observed, suggesting potential functional changes. ConclusionThis study provides evidence for causal effects of periodontitis on conventional serum lipids and plasma lipoprotein subfractions. As the underlying biological mechanisms are not fully understood, further research is needed.

Unveiling the dynamics of intraoperative contamination in total hip arthroplasty: the discrepancy between particulate and microbial contamination in surgical site infection risk

BackgroundSurgical site infection (SSI) is a major problem following total hip arthroplasty (THA). This study investigated the impact of a standard intraoperative routine where the surgical team wears full-body exhaust suits (space suits) within a laminar airflow (LAF)-ventilated operating room (OR) on environmental contamination. Our primary objective was to identify potential modifiable intraoperative factors that could be better controlled to minimize SSI risk.MethodsWe implemented an approach involving simultaneous and continuous air sampling throughout actual primary cementless THA procedures. This method concurrently monitored both airborne particle and microbial contamination levels from the time the patient entered the OR for surgery until extubation.ResultsAirborne particulate and microbial contamination significantly increased during the first and second patient repositionings (postural changes) when the surgical team was not wearing space suits. However, their concentration exhibited inconsistent changes during the core surgical procedures, between incision and suturing, when the surgeons wore space suits. The microbial biosensor detected zero median microbes from draping to suturing. In contrast, the particle counter indicated a significant level of airborne particles during head resection and cup press-fitting, suggesting these procedures might generate more non-viable particles.ConclusionsThis study identified a significant portion of airborne particles during the core surgical procedures as non-viable, suggesting that monitoring solely for particle counts might not suffice to estimate SSI risk. Our findings strongly support the use of space suits for surgeons to minimize intraoperative microbial contamination within LAF-ventilated ORs. Therefore, minimizing unnecessary traffic and movement of unsterile personnel is crucial. Additionally, since our data suggest increased contamination during patient repositioning, effectively controlling contamination during the first postural change plays a key role in maintaining low microbial contamination levels throughout the surgery. The use of sterile gowns during this initial maneuver might further reduce SSIs. Further research is warranted to investigate the impact of sterile attire on SSIs.

Identification of GPNMB in endometrial cancer based on pan-cancer analysis and in vitro validation

BackgroundGPNMB is a type I transmembrane protein, and emerging evidence supports the relationship between GPNMB and cancers.ObjectiveThrough a comprehensive pan-cancer analysis, we examined the expression levels, prognostic significance, and mutation profiles of GPNMB in different cancer types. Subsequently, utilizing in vitro experiments, we elucidated the impact of GPNMB in endometrial cancer (EC).MethodsTIMER2, GEPIA2, UALCAN and cBioPortal were used to analyze the expression pattern, prognostic values, and mutation status of GPNMB. HEC-1B and Ishikawa cells were used to conduct in vitro analyses of GPNMB overexpression. GeneMANIA and TIMER2 were used to evaluate the potential functions and correlations between GPNMB expression and tumor-infiltrating immune cells in EC.ResultsGPNMB was found to be highly expressed in multiple cancers, where it was associated with poor prognosis. Additionally, GPNMB was downregulated at both mRNA and protein levels in EC. Overexpression of GPNMB inhibited the proliferation, migration, and invasion of HEC-1B and Ishikawa cells. Functional analysis showed that GPNMB was enriched in pathways associated with regulation of plasma lipoprotein particle levels. The expression of GPNMB was positively connected with B cell, CD8+ T cell, CD4+ T cell, Macrophage, Neutrophil, and Dendritic cell levels.ConclusionThrough pan-cancer analysis, we identified the antitumor effect of GPNMB in EC and predicted the potential mechanisms between GPNMB expression and EC.

Elevated levels of apolipoprotein A4 in umbilical cord serum from the maternal major depressive disorder.

Prenatal maternal depression is known to affect the neurodevelopment of offspring. This study aimed to investigate the profile of umbilical cord serum in mothers with major depressive disorder (MDD). Liquid chromatography-tandem mass spectrometry (LC-MS) was conducted using umbilical cord serum from mothers with MDD (n = 5) and controls (control, n = 5). The levels of several differentially expressed proteins in umbilical cord serum were compared between the MDD (n = 10) and control groups (n = 10) by enzyme-linked immunosorbent assay. The proteomic profiles in the umbilical cord serum were different between the MDD and control groups, including the pathways of regulation of plasma lipoprotein particle levels, and synapse organization. Only apolipoprotein A4 (APOA4) was significantly higher in the cord blood of MDD group. APOA4 levels in maternal serum were also significantly higher in the MDD group than those in the control group. The APOA4 levels in the umbilical cord serum were higher than that in the maternal serum. The levels of APOA4, a biomarker of depression, in the umbilical cord serum at birth were elevated in the neonates of MDD mothers. It is, therefore, likely that fetuses of MDD mothers were exposed to higher APOA4 levels in utero and this could have developmental and mental health implications for the offspring.

Accuracy of estimating a human-sighted visual range for short-term particulate matter concentration in Chiang Mai, Thailand

Background: Haze crisis in the North Thailand has occurred more than decade. Although four air monitoring stations (Air4Thai) are installed in Chiang Mai, three stations are in the city. According to the California Department of Public Health, communities have used both measurement devices and visual estimates as the concentration of smog changes quickly. Therefore, particle levels are estimated from visual assessments or visual views as another measurement as well. This study aims to assess whether human-sighted visual range is reliable or not in Chiang Mai areas. Objectives: To determine accuracy of human-sighted visual range to estimating short-term Particulate Matter (PM) concentration Methods: A retrospective study was conducted purposively among hospitals and Public Health Office at 25 districts in Chiang Mai province where DustBoy air measurement devices were installed and reported air quality including PM2.5, PM10, temperature and relative humidity. The human-sighted visual range (Hr) were reported by trained health staff following the manual applied from “Wildfire Smoke, A Guide for Public Health Officials”. The Hr were reported into six color levels: blue, green, yellow, light orange, dark orange, and red., three times per day in morning (9.00), afternoon (13.00) and evening (16.00). Data was collected between April and May 2018. Both data were matched according to the date and time, excepted data with relative humidity exceeded 65% were excluded. Descriptive statistics described general data and Cohen's kappa statistics analyzed the accuracy of Hr. Results: Hr accuracy for PM10 was at a good level (79.21%) while Hr for PM2.5 was not useful (26.49%). Conclusion: Human-sighted visual range could be applicable for PM10 assessments for community. However, it would not be effective in early-morning, twilight-hours, rainy day, cloudy or humidity &gt;65%. Moreover, personal experience and judgment should be of concern.

Associations of Adipokine Levels With Levels of Remnant Cholesterol: The Multi-Ethnic Study of Atherosclerosis.

The metabolic syndrome phenotype of individuals with obesity is characterized by elevated levels of triglyceride-rich lipoproteins and remnant particles, which have been shown to be significantly atherogenic. Understanding the association between adipokines, endogenous hormones produced by adipose tissue, and remnant cholesterol (RC) would give insight into the link between obesity and atherosclerotic cardiovascular disease. We studied 1791 MESA (Multi-Ethnic Study of Atherosclerosis) participants who took part in an ancillary study on body composition with adipokine levels measured (leptin, adiponectin, and resistin) at either visit 2 or visit 3. RC was calculated as non-high-density lipoprotein cholesterol minus low-density lipoprotein cholesterol, measured at the same visit as the adipokines, as well as subsequent visits 4 through 6. Multivariable-adjusted linear mixed-effects models were used to assess the cross-sectional and longitudinal associations between adipokines and log-transformed levels of RC. Mean±SD age was 64.5±9.6 years; mean±SD body mass index was 29.9±5.0 kg/m2; and 52.0% were women. In fully adjusted cross-sectional models that included body mass index, diabetes, low-density lipoprotein cholesterol, and lipid-lowering therapy, for each 1-unit increment in adiponectin, there was 14.6% (95% CI, 12.2-16.9) lower RC. With each 1-unit increment in leptin and resistin, there was 4.8% (95% CI, 2.7-7.0) and 4.0% (95% CI, 0.2-8.1) higher RC, respectively. Lower adiponectin and higher leptin were also associated with longitudinal increases in RC levels over median follow-up of 5 (interquartile range, 4-8) years. Lower adiponectin and higher leptin levels were independently associated with higher levels of RC at baseline and longitudinal RC increase, even after accounting for body mass index and low-density lipoprotein cholesterol.

Particulate matter in necropsy activities: experience from a health operators’ exposure monitoring campaign

BackgroundOperators in the obituary and necropsy sectors are exposed to various environmental hazards during specific tasks. Despite this exposure, occupational risks have often been underestimated, resulting in a lack of substantial evidence. The primary objectives of this study were to identify sources of chemical risk, establish procedures for monitoring and quantifying exposure during necropsy activities, and recommend adjustments to regulatory guidelines to protect the health of the operators. The study was conducted at the Legal Medicine Unit of the Umberto I General Hospital in Rome, focusing on the quantitative measurement of particulate matter (PM) exposure among at-risk operators during necropsy activities. Environmental levels of total suspended particles, PM10, PM4, PM2.5, and PM1 were assessed by evaluating the average, minimum, and maximum instantaneous indoor concentrations using an airborne analyzer.ResultsThe monitoring activities revealed that the PM concentrations were significantly lower than the recognized reference values. However, bone sawing, body removal, and cleaning were identified as high-risk maneuvers for dust suspension.ConclusionsOur study highlighted specific risks associated with necropsy activities, particularly concerning timing and certain maneuvers. These results may lead to interventions for improving current prevention procedures, implementing good practices, and developing specific guidelines to enhance operator safety.

Air Pollution and the Prevalence of Keratoconus: Is There a Connection?

ABSTRACT Purpose Keratoconus is a progressive, asymmetrical corneal ectasia with multifactorial origin. Three identified risk factors for keratoconus include exposure to ultraviolet (UV) rays, eye rubbing, and atopy. Other factors like pollution would play a role in the physiopathology of keratoconus. In this study we investigate the effects of particles matter (PM) of 2.5 and 10 μm, but also nitrogen dioxide (NO2) and the correlation with the prevalence in the scientific literature. Method A literature review was performed using four databases (PubMed, Research gate, Google scholar and International Journal of Keratoconus and Ectatic Corneal Diseases) according to strict selection criteria. Levels of fine particles and nitrogen dioxide were extracted from available World Health Organization (WHO) databases and correlated with prevalences from epidemiological studies. Results The mean pollution rate in the selected studies was 26.88 ± 25.26 μg/m3 for PM2.5 , 58.23 ± 60.98 μg/m3 for PM10 and 24.79 ± 12.58 μg/m3 for NO2. Pearson correlation tests revealed a significant positive correlation between prevalence of keratoconus with particles rate of PM2.5 (R = 0.58; p < 0.001), PM10 (R = 0.67; p < 0.001) and NO2 (R = 0.64; p = 0.00016). Conclusion Fine particles appear to be a risk factor for keratoconus. These pollutants may act indirectly by exacerbating known risk factors such as atopy and eye rubbing. Atmospheric pollution may also have a direct effect on the cornea, by disturbing the structure of the epithelium and increasing cell apoptosis.

Serum calciprotein particle-to-phosphate ratio as a predictor of cardiovascular events in incident hemodialysis patients.

Recent studies have identified increased blood calciprotein particle (CPP) levels as risk factors for vascular calcification and cardiovascular events in patients undergoing maintenance hemodialysis. Although positively correlated with serum phosphate levels, serum CPP levels vary considerably among patients with similar serum phosphate levels. We investigated the capacity of the ratio of serum CPP levels to serum phosphate levels (CPP/Pi ratio) to predict cardiovascular events in incident hemodialysis patients compared to the serum calcification propensity test (T50). The association between the CPP/Pi ratio and major adverse cardiac and cerebrovascular events (MACCE) was investigated in 174 incident hemodialysis patients. Multivariate analysis revealed that the CPP/Pi ratio was independently associated with MACCE [hazard ratio 1.60, 95% confidence interval (1.15-2.23), p = 0.006] but serum T50 levels were not. The CPP/Pi ratio is a useful, novel biomarker for predicting the risk of cardiovascular events in patients undergoing incident hemodialysis.

Dual Grain Refinement Effect for Pure Aluminum with the Addition of Micrometer-Sized TiB2 Particles.

The inefficiency of grain refinement processes has traditionally been attributed to the limited utilization of heterogeneous nucleation particles within master alloy systems, resulting in the formation of abundant inactive particles. This study aims to investigate the alternative influences of particles by incorporating external micrometer-sized TiB2 particles into the grain refinement process. Through a series of experiments, the refinement efficiency, grain refinement mechanism, and resultant microstructure of TiB2 particle-induced grain refinement specimens are comprehensively examined using various microscopy and analytical techniques, including polarization microscopy (OM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). Our findings demonstrate a direct correlation between increased levels of TiB2 particles and enhanced grain refinement efficiency. Moreover, the microstructure analysis reveals the distribution of TiB2 particles along grain boundaries, forming a coating due to self-assembly phenomena, while regions with a lower particle content may exhibit irregular grain structures. DSC analysis further confirms reduced undercooling, indicating the occurrence of heterogeneous nucleation events. However, TEM observations suggest that heterogeneous nucleation is not significantly influenced by the growth restriction factor attributed to TiAl3 2DC compounds. The grain refinement mechanism involving TiB2 particles is elucidated to entail both heterogeneous nucleation and physical growth restriction effects. Specifically, a reduction in average grain size is attributed not only to heterogeneous nucleation but also to the physical growth restriction effect facilitated by the TiB2 particle coating. This study offers insights into leveraging particles that do not participate in heterogeneous nucleation within master alloy-based grain refinement systems.

Insights into chemical aging of urban aerosols over Delhi, India

Atmospheric particles can undergo aging as they are transported over long distances and mix with particles from other sources. This can lead to the accumulation of pollutants and the formation of complex aerosol mixtures with diverse chemical and physical properties. To investigate the process of aging in ambient atmosphere, 24h sampling of PM2.5 aerosol particles on Quartz microfiber filter with a tin substrate was carried out from November 2020 to March 2021 at CSIR-National Physical Laboratory, New Delhi (28°38'10″ N and 77°10′17" E), using fine particle sampler. Based on the observations of weather and meteorological parameters, a few episodic cases have been selected, and samples were analyzed at bulk and individual particle level. The objective of the present study is to investigate the aging characteristics of aerosols, enabling us to understand the mixing of aerosols (at both bulk and individual particle levels) and the variation in fresh and deformed (aged with other species) graphitic content in the episodic cases. The Raman Spectroscopy technique employed measures the intensity of graphitic (G band; around 1580 cm−1) and disordered graphitic (D band; around 1320 cm−1) content of aerosols. Individual particle microscopic observations reveal the occurrence of open chain fractals of black carbon in variable monomer sizes, sometimes agglomerated with metals like Cu, Cr, Ca etc., along with the presence of S- rich and organic aerosols while the Raman Spectrum (bulk sample analysis) highlights graphitic and disordered (when graphite interacts with other chemical species) graphitic intensities. Comparing the intensities of heavy haze and moderate haze with non-haze days (for comparison purpose, March 23, 2021 with the lowest PM2.5 concentration ∼ 62 μg/m3, has been considered as a non-haze day), it was observed that the intensities recorded on haze days were 45 to 200 times higher for the G band and 43 to 93 times higher for the D band; while for moderate haze days, the intensities were 4 to 61 times higher for the G band and 2 to 29 times higher for the D band. These findings suggest chemical processing of BC during haze days.

Open-Path Cavity Ring-Down Spectroscopy for Simultaneous Detection of Hydrogen Chloride and Particles in Cleanroom Environment.

The present study addresses advanced monitoring techniques for particles and airborne molecular contaminants (AMCs) in cleanroom environments, which are crucial for ensuring the integrity of semiconductor manufacturing processes. We focus on quantifying particle levels and a representative AMC, hydrogen chloride (HCl), having known detrimental effects on equipment longevity, product yield, and human health. We have developed a compact laser sensor based on open-path cavity ring-down spectroscopy (CRDS) using a 1742 nm near-infrared diode laser source. The sensor enables the high-sensitivity detection of HCl through absorption by the 2-0 vibrational band with an Allan deviation of 0.15 parts per billion (ppb) over 15 min. For quantifying particle number concentrations, we examine various detection methods based on statistical analyses of Mie scattering-induced ring-down time fluctuations. We find that the ring-down distributions' 3rd and 4th standard moments allow particle detection at densities as low as ~105 m-3 (diameter > 1 μm). These findings provide a basis for the future development of compact cleanroom monitoring instrumentation for wafer-level monitoring for both AMC and particles, including mobile platforms.

Nuclear-Magnetic-Resonance-Spectroscopy-Derived Serum Biomarkers of Metabolic Vulnerability Are Associated with Disability and Neurodegeneration in Multiple Sclerosis.

Metabolic vulnerabilities can exacerbate inflammatory injury and inhibit repair in multiple sclerosis (MS). The purpose was to evaluate whether blood biomarkers of inflammatory and metabolic vulnerability are associated with MS disability and neurodegeneration. Proton nuclear magnetic resonance spectra were obtained from serum samples from 153 healthy controls, 187 relapsing-remitting, and 91 progressive MS patients. The spectra were analyzed to obtain concentrations of lipoprotein sub-classes, glycated acute-phase proteins, and small-molecule metabolites, including leucine, valine, isoleucine, alanine, and citrate. Composite indices for inflammatory vulnerability, metabolic malnutrition, and metabolic vulnerability were computed. MS disability was measured on the Expanded Disability Status Scale. MRI measures of lesions and whole-brain and tissue-specific volumes were acquired. Valine, leucine, isoleucine, alanine, the Inflammatory Vulnerability Index, the Metabolic Malnutrition Index, and the Metabolic Vulnerability Index differed between healthy control and MS groups in regression analyses adjusted for age, sex, and body mass index. The Expanded Disability Status Scale was associated with small HDL particle levels, inflammatory vulnerability, and metabolic vulnerability. Timed ambulation was associated with inflammatory vulnerability and metabolic vulnerability. Greater metabolic vulnerability and inflammatory vulnerability were associated with lower gray matter, deep gray matter volumes, and greater lateral ventricle volume. Serum-biomarker-derived indices of inflammatory and metabolic vulnerability are associated with disability and neurodegeneration in MS.

Factors associated with seizure response in adults with epilepsy on a modified Atkins diet

PurposeThis study investigated factors associated with improved seizure control in adults with epilepsy following a modified Atkins diet (MAD). MethodsFollow-up data collected from participants enrolled in a prospective study between March 2016 and November 2023 was analyzed. Demographic and clinical differences between diet responders and non-responders were evaluated. MAD response was defined as ≥ 50 % reduction in seizure frequency from baseline. ResultsMAD use led to clinical response in 48 % of study participants with 2–3 month follow-up and in 56 % of study participants with 6 month follow-up. No significant differences were found for gender, age at diet initiation, age at epilepsy diagnosis, or for number of current or past medications tried. However, a significant relationship emerged between epilepsy type and diet response at 6 months with a response of 100 % seen in adults with generalized epilepsy and a response of only 42 % in adults with focal epilepsy (p = 0.004). Those who responded to the diet showed non-significant increases in many of the measured lipid biomarkers. Levels of apolipoprotein-B and small low-density lipoprotein particles showed significant increases from baseline after 3 months in responders compared to non-responders (p = 0.004 and 0.049, respectively). ConclusionsThese findings support the continued use of MAD particularly for seizure management in adults with generalized epilepsy and highlight potential mechanisms of clinical response involving lipoprotein and energy metabolism.