Effect of lysozyme combined with hydrothermal pretreatment on excess sludge and anaerobic digestion.

Anaerobic digestion (AD) is widely employed for sludge stabilization and waste reduction. However, the slow hydrolysis process hinders methane production and leads to prolonged sludge issues. In this study, an efficient and eco-friendly lysozyme pre-treatment method was utilized to address these challenges. By optimizing lysozyme dosage, hydrolysis and cell lysis were maximized. Furthermore, lysozyme combined with hydrothermal pretreatment enhanced overall efficiency. Results indicate that: (1) When lysozyme dosage reached 90 mg/g TS after 240 min of pretreatment, SCOD, soluble polysaccharides, and protein content reached their maxima at 855.00, 44.09, and 204.86 mg/L, respectively. This represented an increase of 85.87%, 365.58%, and 259.21% compared to the untreated sludge. Three-dimensional fluorescence spectroscopy revealed the highest fluorescence intensity in the IV region (soluble microbial product), promoting microbial metabolic activity. (2) Lysozyme combined with hydrothermal pretreatment significantly increased SCOD, soluble proteins, and polysaccharide release from sludge, reducing SCOD release time. Orthogonal experiments identified Group 3 as the most effective for SCOD and soluble polysaccharide release, while Group 9 released the most soluble proteins. The significance order of factors influencing SCOD, soluble proteins, and polysaccharide release is hydrothermal temperature > hydrothermal time > enzymatic digestion time.(3) The lysozyme-assisted hydrothermal pretreatment group exhibited the fastest release and the highest SCOD concentration of 8,135.00 mg/L during anaerobic digestion. Maximum SCOD consumption and cumulative gas production increased by 95.89% and 130.58%, respectively, compared to the control group, allowing gas production to conclude 3 days earlier.

Spatial variation of methane oxidation and carbon dioxide sequestration in landfill biogeochemical cover.

The study investigated the spatial variation of potential methane (CH4) oxidation and residual carbon dioxide (CO2) sequestration in biogeochemical cover (BGCC) system designed to remove CH4, CO2, and hydrogen sulfide (H2S) from landfill gas (LFG) emissions. A 50 cm x 50 cm x 100 cm tank simulated BGCC system, comprising a biochar-amended soil (BAS) layer for CH4 oxidation, a basic oxygen furnace (BOF) slag layer for CO2 and H2S sequestration, and an upper topsoil layer. Synthetic LFG was flushed through the system in five phases, with each corresponding to different compositions and flow rates. Following monitoring, the system was dismantled, and samples were extracted from different depths and locations to analyze spatial variations, focusing on moisture content (MC), organic content (OC), pH, and electrical conductivity (EC). Additionally, batch tests on selected samples from BAS and BOF slag layers were performed to assess potential CH4 oxidation and residual carbonation capacity. The aim of study was to evaluate the BGCC's effectiveness in LFG mitigation, however this study focused on assessing spatial variations in physico-chemical properties, CH4 oxidation in the BAS layer, and residual carbonation in the BOF slag layer. Findings revealed CH4 oxidation in the BAS layer varied between 22.4 and 277.9 µg CH4/g-day, with higher rates in the upper part, and significant spatial variations at 50 cm below ground surface (bgs) compared to 85 cm bgs. The BOF slag layer showed a residual carbonation capacity of 40-49.3 g CO2/kg slag, indicating non-uniform carbonation. Overall, CH4 oxidation and CO2 sequestration capacities varied spatially and with depth in the BGCC system.

An efficient cre-based workflow for genomic integration and expression of large biosynthetic pathways in Eubacterium limosum.

Acetogenic Clostridia are obligate anaerobes that have emerged as promising microbes for the renewable production of biochemicals owing to their ability to efficiently metabolize sustainable single-carbon feedstocks. Additionally, Clostridia are increasingly recognized for their biosynthetic potential, with recent discoveries of diverse secondary metabolites ranging from antibiotics to pigments to modulators of the human gut microbiota. Lack of efficient methods for genomic integration and expression of large heterologous DNA constructs remains a major challenge in studying biosynthesis in Clostridia and using them for metabolic engineering applications. To overcome this problem, we harnessed chassis-independent recombinase-assisted genome engineering (CRAGE) to develop a workflow for facile integration of large gene clusters (>10 kb) into the human gut acetogen Eubacterium limosum. We then integrated a non-ribosomal peptide synthetase gene cluster from the gut anaerobe Clostridium leptum, which previously produced no detectable product in traditional heterologous hosts. Chromosomal expression in E. limosum without further optimization led to production of phevalin at 2.4 mg/L. These results further expand the molecular toolkit for a highly tractable member of the Clostridia, paving the way for sophisticated pathway engineering efforts, and highlighting the potential of E. limosum as a Clostridial chassis for exploration of anaerobic natural product biosynthesis.

High-Throughput Compatibility Screening of Materials for SF6-Alternative Insulation.

With the annual global electricity production exceeding 30,000 TWh, the safe transmission of electric power has been heavily relying on SF6, the most potent industrial greenhouse gas. While promising SF6 alternatives have been proposed, their compatibilities with materials used in gas-insulated equipment (GIE) must be thoroughly studied. This is particularly true as the emerging SF6 alternatives generally leverage their relatively higher reactivity to achieve lower global warming potentials (GWPs). Here, a high-throughput compatibility screening of common GIE materials was conducted with a representative SF6 alternative, namely, C4F7N (2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanenitrile)/CO2 gas mixtures. In this screening, the insulation performance of C4F7N/CO2 gas mixtures, as an indicator of the C4F7N/materials compatibility level, was periodically monitored during the thermal aging with tens of materials from SF6-insulated GIE, including desiccants/adsorbents, rubber, plastics, composites, ceramics, metals, etc. The identification of incompatible materials and the follow-up mechanism studies suggested that the acidity of materials represents the primary cause for C4F7N/materials incompatibility when C4F7N/CO2 gas mixtures are used as a drop-in replacement solution for existing SF6-insulated apparatuses. Mitigation strategies tackling the acidity of materials were then proposed and validated. Additionally, the amphoteric characteristics of C4F7N were briefly discussed. This work provides insight into the materials incompatibility of SF6 alternatives, along with validated mitigation strategies, for the selection and design of materials used in future eco-friendly GIE.

Oxidized Melanoma Antigens Promote Activation and Proliferation of Cytotoxic T-Cell Subpopulations.

Increasing evidence suggests the role of reactive oxygen and nitrogen species (RONS) in regulating antitumor immune effects and immunosuppression. RONS modify biomolecules and induce oxidative post-translational modifications (oxPTM) on proteins that can alarm phagocytes. However, it is unclear if and how protein oxidation by technical means could be a strategy to foster antitumor immunity and therapy. To this end, cold gas plasma technology producing various RONS simultaneously to oxidize the two melanoma-associated antigens MART and PMEL is utilized. Cold plasma-oxidized MART (oxMART) and PMEL (oxPMEL) are heavily decorated with oxPTMs as determined by mass spectrometry. Immunization with oxidized MART or PMEL vaccines prior to challenge with viable melanoma cells correlated with significant changes in cytokine secretion and altered T-cell differentiation of tumor-infiltrated leukocytes (TILs). oxMART promoted the activity of cytotoxic central memory T-cells, while oxPMEL led to increased proliferation of cytotoxic effector T-cells. Similar T-cell results are observed after incubating splenocytes of tumor-bearing mice with B16F10 melanoma cells. This study, for the first time, provides evidence of the importance of oxidative modifications of two melanoma-associated antigens in eliciting anticancer immunity.

Implications of intracochlear decomposition gas formation in non-putrefied cadavers.

Introduction: Postmortem computed tomography (pmCT) prior to forensic autopsy has become increasingly important in recent decades, especially in forensic documentation of single injuries, injury patterns, and causes of death. Postmortem decomposition gas formation can also be detected in pmCT scans, which might affect cochlear implant research in postmortem human temporal bones (TBs). Material and methods: Fifty non-putrefied hanging fatalities within a 2-year period (January 2017 to December 2019) were included with 100 TBs. Each body underwent whole-body pmCT prior to forensic autopsy. PmCT scans were analyzed with respect to the presence of intracochlear gas despite the lack of putrefaction at autopsy by an experienced fellow neurotologist. Results: PmCT revealed gas formation in two individuals despite the lack of head trauma and putrefaction at postmortem examination and autopsy. Both individuals showed enclosed gas in the vestibule and the cochlea on both sides. Discussion: Intracochlear gas formation, most likely related to decomposition, may occur despite the lack of putrefaction at postmortem examination and autopsy and can be detected by pmCT. This finding seems to be rather rare in non-traumatic death cases but might affect cochlear pressure research in postmortem human TB.

Hydrophobic-treated yolk-shell SnS2@CSs Z-scheme confinement reactor for solar-electro-driven hydrogen peroxide production in neutral media.

The diffusion and adsorption properties of the O2/H2O corpuscles at active sites play a crucial role in the fast photo-electrocatalytic reaction of hydrogen peroxide (H2O2) production. Herein, SnS2 nanosheets with abundant interfacial boundaries and large specific areas are encapsulated into hollow mesoporous carbon spheres (CSs) with flexibility, producing a yolk-shell SnS2@CSs Z-scheme photocatalyst. The nanoconfined microenvironment of SnS2@CSs could enrich O2/H2O in catalyst cavities, which allows sufficient internal O2 transfer, improving the surface chemistry of catalytic O2 to O2- conversion and increasing reaction kinetics. By shaping the mixture of SnS2@CSs and polytetrafluoroethylene (PTFE) on carbon felt (CF) using the vacuum filtration method, the natural air-breathing gas diffusion photoelectrode (AGPE) was prepared, and it can achieve an accumulated concentration of H2O2 about 12 mM after a 10 h stability test from pure water at natural pH without using electrolyte and sacrificial agents. The H2O2 product is upgraded through one downstream route of conversion of H2O2 to sodium perborate. The improved H2O2 production performance could be ascribed to the combination of the confinement effect of SnS2@CSs and the rich triple phase interfaces with the continuous hydrophobic layer and hydrophilic layer to synergistically modulate the photoelectron catalytic microenvironment, which enhanced the transfer of O2 mass and offered a stronger affinity to oxygen bubbles. The strategy of combining the confined material with the air-breathing gas diffusion electrode equips a wide practical range of applications for the synthesis of high-yield hydrogen peroxide.

Sustainability in surgical practice: a collaborative call toward environmental sustainability in operating rooms.

BACKGROUND: The healthcare system plays a pivotal role in environmental sustainability, and the operating room (OR) significantly contributes to its overall carbon footprint. In response to this critical challenge, leading medical societies, government bodies, regulatory agencies, and industry stakeholders are taking measures to address healthcare sustainability and its impact on climate change. Healthcare now represents almost 20% of the US national economy and 8.5% of US carbon emissions. Internationally, healthcare represents 5% of global carbon emissions. US Healthcare is an outlier in both per capita cost, and per capita greenhouse gas emission, with almost twice per capita emissions compared to every other country in the world. METHODS: The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) and the European Association for Endoscopic Surgery (EAES) established the Sustainability in Surgical Practice joint task force in 2023. This collaborative effort aims to actively promote education, mitigation, and innovation, steering surgical practices toward a more sustainable future. RESULTS: Several key initiatives have included a survey of members' knowledge and awareness, a scoping review of terminology, metrics, and initiatives, and deep engagement of key stakeholders. DISCUSSION: This position paper serves as a Call to Action, proposing a series of actions to catalyze and accelerate the surgical sustainability leadership needed to respond effectively to climate change, and to lead the societal transformation towards health that our times demand.

Efficient Removal of Greenhouse Gases: Machine Learning-Assisted Exploration of Metal-Organic Framework Space.

Global warming is a crisis that humanity must face together. With greenhouse gases (GHGs) as the main factor causing global warming, the adoption of relevant processes to eliminate them is essential. With the advantages of high specific surface area, large pore volume, and tunable synthesis, metal-organic frameworks (MOFs) have attracted much attention in GHG storage, adsorption, separation, and catalysis. However, as the pool of MOFs expands rapidly with new syntheses and discoveries, finding a suitable MOF for a particular application is highly challenging. In this regard, high-throughput computational screening is considered the most effective research method for screening a large number of materials to discover high-performance target MOFs. Typically, high-throughput computational screening generates voluminous and multidimensional data, which is well suited for machine learning (ML) training to improve the screening efficiency and explore the relationships between the multidimensional data in depth. This Review summarizes the general process and common methods for using ML to screen MOFs in the field of GHG removal. It also addresses the challenges faced by ML in exploring the MOF space and potential directions for the future development of ML for MOF screening. This aims to enhance the understanding of the integration of ML and MOFs in various fields and broaden the application and development ideas of MOFs.

Exhaled Anesthetic Xenon Regeneration by Gas Separation Using a Metal-Organic Framework with Sorbent-Sorbate Induced-Fit.

Noble gas xenon (Xe) is an excellent anesthetic gas, but its rarity, high cost and constrained production prohibits wide use in medicine. Here, we have developed a closed-circuit anesthetic Xe recovery and reusage process with highly effective CO2-specific adsorbent CUPMOF-5 that is promising to solve the anesthetic Xe supply problem. CUPMOF-5 possesses spacious cage cavities interconnected in four directions by confinement throat apertures of ~3.4 Å, which makes it an ideal molecular sieving of CO2 from Xe, O2, N2 with the benchmark selectivity and high uptake capacity of CO2. In-situ single-crystal X-ray diffraction (SCXRD) and computational simulation solidly revealed the vital sieving role of the confined throat and the sorbent-sorbate induced-fit strengthening binding interaction to CO2. CUPMOF-5 can remove 5% CO2 even from actual moist exhaled anesthetic gases, and achieves the highest Xe recovery rate (99.8%) so far, as verified by breakthrough experiments. This endows CUPMOF-5 great potential for the on-line CO2 removal and Xe recovery from anesthetic closed-circuits.

In-situ electrochemical impedance analysis of a commercial SOFC stack fueled by real wood gas.

The combination of solid oxide fuel cells (SOFCs) and wood gasification has the potential to significantly increase renewable electricity production and decrease emissions. Depending on the quality of the wood gas, degradation processes have a significant impact on the reliability and lifetime of the SOFC. Using electrochemical impedance spectroscopy (EIS) and subsequent distribution of relaxation times (DRT) analysis, the impact on the degradation of coupling wood gasification with a commercial SOFC stack is determined in this study. The thermal behavior of the SOFC stack under various operating conditions, as well as various synthetic wood gas mixtures classified by their hydrogen-to-carbon (H/C) ratio, was assessed. The decrease in the H/C ratio from 8 to 1, observed during syngas and real wood gas operation, leads to a rightward shift in the Nyquist plots, suggesting an increase in the SOFC stack's impedance. Correlations between variations in the H/C ratio and their effects on anodic electrooxidation, ionic conduction, gas transport, and diffusion were identified using DRT analysis to interpret the EIS results. By incorporating an upstream desulfurization system and ensuring an H/C ratio greater than 2, the coupling of biomass gasification with the SOFC stack was stable to degradation issues.

Ecophysiological and nutritional characterisation of two morphotypes of Cakile maritima subsp. maritima Scop. from Puglia region, Southern Italy.

Cakile maritima subsp. maritima Scop. (sea rocket) is a succulent halophyte with significant potential as a nutritious food source, being rich in essential nutrients such as vitamins, minerals, and antioxidants. This annual species exhibits two distinct leaf morphotypes: entire lamina (EL) and pinnatifid lamina (PL). Our understanding of their ecophysiological and nutritional profiles is still limited. The present study investigated the wild EL and PL sea rocket plants from southern Italy during their vegetative stage. The bio-morphological traits (leaf mass area-LMA, dry matter and chlorophyll concentrations), main inorganic ions, key antioxidants (carotenoids, anthocyanins, phenols, flavonoids, glucosinolates, vitamin C as ascorbic and dehydroascorbic acid), and antioxidant activity (by FRAP, DPPH, ABTS assays) were analyzed. Additionally, photosynthetic gas exchange and chlorophyll fluorescence were measured. PL plants showed thicker leaves (higher LMA) and greater accumulation of photo-protective pigments (carotenoids and anthocyanins), despite similar chlorophyll levels. The PL plants also demonstrated higher photosynthetic activity, transpiration rates, and stomatal conductance, with reduced non-photochemical quenching. The EL morphotype had higher cation (K, Mg, Ca, Na) and vitamin C (135.3 mg 100 g-1 FW) concentrations, while no significant disparities were observed between the morphotypes in phenolic concentration (208.5 mg g.a.e. 100 g-1 FW), flavonoids (71.5 mg q.e. 100 g-1 FW), or glucosinolates (61 mg g-1 FW). Interestingly, while the EL type had higher vitamin C, the PL morphotype showed superior antioxidant activity (FRAP, DPPH) and seems to be better adapted to water/nutrient scarcity typical of southern Italy. Both morphotypes offer potential as high-nutritional foods, however, future research should investigate the genotype-specific production of antioxidant compounds in EL and PL plants in response to environmental stresses, including salinity for potential exploitation as a new crop.

The role of water bridge on gas adsorption and transportation mechanisms in organic shale.

This work introduces and discusses the impacts of the water bridge on gas adsorption and diffusion behaviors in a shale gas-bearing formation. The density distribution of the water bridge has been analyzed in micropores and meso-slit by molecular dynamics. Na+ and Cl- have been introduced into the system to mimic a practical encroachment environment and compared with pure water to probe the deviation in water bridge distribution. Additionally, practical subsurface scenarios, including pressure and temperature, are examined to reveal the effects on gas adsorption and diffusion properties, determining the shale gas transportation in realistic shale formation. The outcomes suggest carbon dioxide (CO2) usually has higher adsorption than methane (CH4) with a water bridge. Increasing temperature hinders gas adsorption, density distribution decreases in all directions. Increasing pressure facilitates gas adsorption, particularly as a bulk phase in the meso-slit, whereas it restricts gas diffusion by enhancing the interaction strength between gas and shale. Furthermore, ions make the water bridge distributes more unity and shifts to the slit center, impeding gas adsorption onto shale while encouraging gas diffusion. This study provides updated guidelines for gas adsorption and transportation characteristics and supports the fundamental understanding of industrial shale gas exploration and transportation.

Characterization of flavor volatiles in raw and cooked pigmented onion (Allium cepa L) bulbs: A comparative HS-GC-IMS fingerprinting study.

Variations in volatile flavor components in pigmented onion bulbs (purple, white, and yellow) before and after cooking were characterized by headspace gas chromatography-ion migration spectrometry (HS-GC-IMS) to investigate their odor traits. Results showed that 39 and 45 volatile flavor compounds were identified from pigmented onion bulbs before and after cooking via the HS-GC-IMS fingerprinting, respectively. Sulfurs (accounting for 50.65%-63.42%), aldehydes (13.36%-22.11%), and alcohols (11.32%-17.94%) ranked the top three prevailing compound categories in all pigmented onions (both raw and cooked). Compared to the raw colored onion bulbs, the relative proportion of sulfurs in cooked onions decreased, whereas the relative proportion of alcohols, esters, pyrazines, and furans increased. Two reliable prediction models were established through orthogonal partial least squares-discriminant analysis (OPLS-DA), and 8 and 22 distinctive odor compounds were sieved out by variable importance in projection (VIP>1.0) as volatile labels, respectively. Both principal component analysis (PCA) and clustering heatmap exhibited favorable distinguishing effects for various pigmented onion bulbs before and after cooking. These results might offer insights into understanding the odor characteristics of different pigmented onions.

Alveolar Microdynamics during Tidal Ventilation in Live Animals Imaged by SPring-8 Synchrotron.

It is self-evident that our chests expand and contract during breathing but, surprisingly, exactly how individual alveoli change shape over the respiratory cycle is still a matter of debate. Some argue that all the alveoli expand and contract rhythmically. Others claim that the lung volume change is due to groups of alveoli collapsing and reopening during ventilation. Although this question might seem to be an insignificant detail for healthy individuals, it might be a matter of life and death for patients with compromised lungs. Past analyses were based on static post-mortem preparations primarily due to technological limitations, and therefore, by definition, incapable of providing dynamic information. In contrast, this study provides the first comprehensive dynamic data on how the shape of the alveoli changes, and, further, provides valuable insights into the optimal lung volume for efficient gas exchange. It is concluded that alveolar micro-dynamics is nonlinear; and at medium lung volume, alveoli expand more than the ducts.

Efficiency of passive activated carbon anaesthetic gas capturing systems during simulated ventilation.

BACKGROUND: Interest in passive flow filter systems to remove sevoflurane from anaesthetic machine exhaust have increased recently to mitigate the environmental impact of volatile anaesthetics. These filter systems consist of chemically activated carbon, with limited evidence on their performance characteristics. We hypothesised that their efficiency depends on filter material. METHODS: Binding capacity was tested for three carbon filter materials (CONTRAfluran®, FlurAbsorb®, and Anaesthetic Agent Filter AAF633). Adsorption efficiency and resistive pressure were determined during simulated ventilation at different stages of filter saturation and fresh gas flow. In addition, sevoflurane concentration in filtered gas was measured at randomly selected anaesthesia workstations. RESULTS: Sevoflurane concentration in filtered gas exceeded 10 ppm when saturated with 184 ml sevoflurane each for CONTRAfluran and FlurAbsorb and 276 ml for AAF633. During simulated ventilation, sevoflurane concentration >10 ppm passed through CONTRAfluran and AAF633 at fresh gas flow 10 L min-1 only at maximum saturation, but through FlurAbsorb at all stages of saturation. The resistance pressure of all filters was negligible during simulated ventilation, but increased up to 5.2 (0.2) cm H2O during simulated coughing. At two of seven anaesthesia workstations, sevoflurane concentration in filtered exhaust gas was >10 ppm. CONCLUSIONS: Depending on the filter material and saturation, the likelihood of sevoflurane passing through passive flow carbon filters depends on the filter material and fresh gas flow. Combining the filter systems with anaesthetic gas scavenging systems could protect from pollution of ambient air with sevoflurane.

CoCorrole-Functionalized PCN-222 for Carbon Monoxide Selective Adsorption.

The high risk of CO poisoning justifies the need for indoor air quality control and warning systems based on the detection of low concentrations (ppm-ppb) of CO. Cobalt corrole complexes selectively bind CO vs. O2, CO2, N2, opening new fields of applications. By combining the CO chemisorption properties of cobalt corroles with the known sorption capacity of MOFs, we hope to obtain high performance sensing materials for CO detection. In addition, the exposed metal sites of MOFs lead to CO2 physisorption, allowing the co-detection of CO and CO2. In this work, PCN-222 a stable Zr-based MOF made from Ni(TCPP) with natural vacancies has been used as a porous matrix for the grafting of electron-poor metallocorroles. The materials were characterized by powder XRD, SEM and optical microscopy, BET analyses and gas adsorption measurements at 298 K. No degradation of the crystalline structure of PCN-222 was observed. At 1 atm, the adsorbed CO(g) volumes measured for the best materials were 12.15 cm3 g-1 and 14.01 cm3 g-1 for CoCorr2@PCN-222 and CoCorr3@PCN-222 respectively, and both materials exhibited high CO chemisorption and selectivity against O2, N2, and CO2 at low pressure due to the highest energy of the chemisorption process vs physisorption. (198 Words).

Machine learning prediction of methane, nitrogen, and natural gas mixture viscosities under normal and harsh conditions.

The accurate estimation of gas viscosity remains a pivotal concern for petroleum engineers, exerting substantial influence on the modeling efficacy of natural gas operations. Due to their time-consuming and costly nature, experimental measurements of gas viscosity are challenging. Data-based machine learning (ML) techniques afford a resourceful and less exhausting substitution, aiding research and industry at gas modeling that is incredible to reach in the laboratory. Statistical approaches were used to analyze the experimental data before applying machine learning. Seven machine learning techniques specifically Linear Regression, random forest (RF), decision trees, gradient boosting, K-nearest neighbors, Nu support vector regression (NuSVR), and artificial neural network (ANN) were applied for the prediction of methane (CH4), nitrogen (N2), and natural gas mixture viscosities. More than 4304 datasets from real experimental data utilizing pressure, temperature, and gas density were employed for developing ML models. Furthermore, three novel correlations have developed for the viscosity of CH4, N2, and composite gas using ANN. Results revealed that models and anticipated correlations predicted methane, nitrogen, and natural gas mixture viscosities with high precision. Results designated that the ANN, RF, and gradient Boosting models have performed better with a coefficient of determination (R2) of 0.99 for testing data sets of methane, nitrogen, and natural gas mixture viscosities. However, linear regression and NuSVR have performed poorly with a coefficient of determination (R2) of 0.07 and - 0.01 respectively for testing data sets of nitrogen viscosity. Such machine learning models offer the industry and research a cost-effective and fast tool for accurately approximating the viscosities of methane, nitrogen, and gas mixture under normal and harsh conditions.

A novel variant in GAS2 is associated with autosomal dominant nonsyndromic hearing impairment in a Chinese family.

Knockout of GAS2 (growth arrest-specific protein 2), causes disorganization and destabilization of microtubule bundles in supporting cells of the cochlear duct, leading to hearing loss in vivo. However, the molecular mechanism through which GAS2 variant results in hearing loss remains unknown. By Whole-exome sequencing, we identified a novel heterozygous splicing variant in GAS2 (c.616-2 A > G) as the only candidate mutation segregating with late-onset and progressive nonsyndromic hearing loss (NSHL) in a large dominant family. This splicing mutation causes an intron retention and produces a C-terminal truncated protein (named GAS2mu). Mechanistically, the degradation of GAS2mu via the ubiquitin-proteasome pathway is enhanced, and cells expressing GAS2mu exhibit disorganized microtubule bundles. Additionally, GAS2mu further promotes apoptosis by increasing the Bcl-xS/Bcl-xL ratio instead of through the p53-dependent pathway as wild-type GAS2 does, indicating that GAS2mu acts as a toxic molecule to exacerbate apoptosis. Our findings demonstrate that this novel variant of GAS2 promotes its own protein degradation, microtubule disorganization and cellular apoptosis, leading to hearing loss in carriers. This study expands the spectrum of GAS2 variants and elucidates the underlying pathogenic mechanisms, providing a foundation for future investigations of new therapeutic strategies to prevent GAS2-associated progressive hearing loss.

Oil and gas development exposure and atrial fibrillation exacerbation: a retrospective study of atrial fibrillation exacerbation using Colorado's all payer claims dataset.

Introduction: Emerging risk factors for atrial fibrillation (AF) incidence and episodes (exacerbation), the most common and clinically significant cardiac arrhythmia, include air and noise pollution, both of which are emitted during oil and natural gas (O&G) well site development. Methods: We evaluated AF exacerbation risk and proximity to O&G well site development by employing a novel data source and interrupted time-series design. We retrospectively followed 1,197 AF patients living within 1-mile of an O&G well site (at-risk of exposure) and 9,764 patients living >2 miles from any O&G well site (unexposed) for AF claims in Colorado's All Payer Claims Dataset before, during, and after O&G well site development. We calculated AF exacerbation risk with multi-failure survival analysis. Results: The analysis of the total study population does not provide strong evidence of an association between AF exacerbation and proximity to O&G wells sites during (HR = 1.07, 95% CI: 0.94, 1.22) or after (HR = 1.01, 95% CI: 0.88, 1.16) development. However, AF exacerbation risk differed by patient age and sex. In patients >80 years living within 0.39 miles (2,059 feet) of O&G well site development, AF exacerbation risk increased by 83% (HR = 1.83, 95% CI: 1.25, 2.66) and emergency room visits for an AF event doubled (HR = 2.55, 95% CI: 1.50, 4.36) during development, with risk increasing with proximity. In female patients living within 0.39 miles of O&G well site development, AF exacerbation risk increased by 56% percent (95% CI: 1.13, 2.15) during development. AF exacerbation risk did not persist past the well development period. We did not observe increased AF exacerbation risk in younger or male patients. Discussion: The prospect that proximity to O&G well site development, a significant noise and air pollution source, may increase AF exacerbation risk in older and female AF patients requires attention. These findings support appropriate patient education to help mitigate risk and development of mitigation strategies and regulations to protect the health of populations in O&G development regions.