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Environmental Science: Atmospheres Sep 2023Pellet combustion in residential heating stoves has increased globally during the last decade. Despite their high combustion efficiency, the widespread use of pellet...
Pellet combustion in residential heating stoves has increased globally during the last decade. Despite their high combustion efficiency, the widespread use of pellet stoves is expected to adversely impact air quality. The atmospheric aging of pellet emissions has received even less attention, focusing mainly on daytime conditions, while the degree to which pellet emissions undergo night-time aging as well as the role of relative humidity remain poorly understood. In this study, environmental simulation chamber experiments were performed to characterize the fresh and aged organic aerosol (OA) emitted by a pellet stove. The fresh pellet stove PM (particulate matter with an aerodynamic diameter less than 1 μm) emissions consisted mainly of OA (93 ± 4%, mean ± standard deviation) and black carbon (5 ± 3%). The primary OA (POA) oxygen-to-carbon ratio (O : C) was 0.58 ± 0.04, higher than that of fresh logwood emissions. The fresh OA at a concentration of 70 μg m (after dilution and equilibration in the chamber) consisted of semi-volatile (68%), low and extremely low volatility (16%) and intermediate-volatility (16%) compounds. The oxidation of pellet emissions under dark conditions was investigated by injecting nitrogen dioxide (NO) and ozone (O) into the chamber, at different (10-80%) relative humidity (RH) levels. In all dark aging experiments secondary organic aerosol (SOA) formation was observed, increasing the OA levels after a few hours of exposure to NO radicals. The change in the aerosol composition and the extent of oxidation depended on RH. For low RH, the SOA mass formed was up to 30% of the initial OA, accompanied by a moderate change in both O : C levels (7-8% increase) and the OA spectrum. Aging under higher RH conditions (60-80%) led to a more oxygenated aerosol (increase in O : C of 11-18%), but only a minor (1-10%) increase in OA mass. The increase in O : C at high RH indicates the importance of heterogeneous aqueous reactions in this system, that oxidize the original OA with a relatively small net change in the OA mass. These results show that the OA in pellet emissions can chemically evolve under low photochemical activity ( the wintertime period) with important enhancement in SOA mass under certain conditions.
PubMed: 38013728
DOI: 10.1039/d3ea00070b -
Polymers Nov 2023Poly(lactic acid) (PLA) and Poly(butylene succinate) (PBS) were chosen as raw materials and melt blended by a twin screw extruder and pelletized; then, the pellets were...
Poly(lactic acid) (PLA) and Poly(butylene succinate) (PBS) were chosen as raw materials and melt blended by a twin screw extruder and pelletized; then, the pellets were extruded into filaments; after that, various PBS/PLA blending samples were prepared by Fused Deposition Molding (FDM) 3D printing technology using the filaments obtained and the effect of the dosage of PBS on technological properties of 3D-printed specimens was investigated. For comparison, the PLA specimen was also prepared by FDM printing. The tensile strength, tensile modulus, thermal stability, and hydrophilicity became poorer with increasing the dosage of PBS, while the flexural strength, flexural modulus, impact strength, and crystallinity increased first and then decreased. The blend containing 10% PBS (10% PBS/PLA) had the greatest flexural strength of 60.12 MPa, tensile modulus of 2360.04 MPa, impact strength of 89.39 kJ/m, and crystallinity of 7.4%, which were increased by 54.65%, 61.04%, 14.78%, and 51.02% compared to those of printed PLA, respectively; this blend also absorbed the least water than any other specimen when immersed in water. Different from the transparent PLA filament, 10% PBS/PLA filament presented a milky white appearance. The printed 10% PBS/PLA specimen had a smooth surface, while the surface of the printed PLA was rough. All the results indicated that the printed 10% PBS/PLA specimen had good comprehensive properties, including improved mechanical properties, crystallization performance, and surface quality than PLA, as well as proper wettability and water absorption. The prominent conclusion achieved in this work was that 10% PBS/PLA should be an ideal candidate for biodegradable feedstock among all the PBS/PLA blends for FDM 3D printing.
PubMed: 37959985
DOI: 10.3390/polym15214305 -
European Journal of Pharmaceutical... Dec 2023FDA's initiative Pharmaceutical CGMPs for the 21st century opened the door for introduction of several risk based approaches in pharmaceutical industry. One significant...
FDA's initiative Pharmaceutical CGMPs for the 21st century opened the door for introduction of several risk based approaches in pharmaceutical industry. One significant advancement that has emerged is the implementation of process analytical technology (PAT), which has opened doors for understanding and controlling complex technological processes. Two such processes, radial extrusion and pellet coating, offer a solid foundation for the application of PAT tools due to their numerous critical process parameters. The aim of the first part of the study was to optimize the neutral pellet production to produce the pellets with properties desired for successful film coating using design of experiments (DoE). In the second part the optimized pellets underwent film coating and the coating quantity was predicted in real or near real-time using in-line and at-line NIR probes and the performance of both probes was compared. The desired properties of the pellets, narrow particle size distribution, high sphericity and high process yield, were successfully achieved. Models for film coating quantity prediction using in-line and at-line NIR probe were successfully calibrated and tested by coating two additional batches. Despite the limited sample size for model calibration, at-line NIR exhibited excellent prediction performance and enabled accurate determination of process end-point. The coating quantity determined by UV/VIS spectroscopy in both test batches deviated by less than 2.0 % from the target value. However, the in-line NIR probe, primarily due to its inferior spectral resolution, displayed a slightly lower quality of the calibrated model and notable overprediction for the tested batches.
Topics: Spectroscopy, Near-Infrared; Technology, Pharmaceutical; Technology; Drug Implants; Drug Industry
PubMed: 37770005
DOI: 10.1016/j.ejps.2023.106595 -
Journal of Clinical Medicine Apr 2024This systematic review aimed to evaluate the impact of antiresorptive drug therapy on osseointegrated dental implants and the association with medication-related... (Review)
Review
This systematic review aimed to evaluate the impact of antiresorptive drug therapy on osseointegrated dental implants and the association with medication-related osteonecrosis of the jaw (MRONJ). A systematic search, including a computer search of several databases with specific keywords, a reference search, and a manual search of four key maxillofacial journals were performed. Relevant articles were then evaluated and those that fulfilled the five predetermined criteria were chosen to enter the final review. A total of 445 implants in 135 subjects were included in the eight studies analyzed in the final review. The failure rate of dental implants after antiresorptive medication in the included studies was 23%, with 83% of failures attributed to MRONJ. The average time from antiresorptive drug initiation to MRONJ development was approximately 34 months, ranging from 3 months to 16 years. The majority of MRONJ cases were classified as stage 2, and all sites showed either complete healing or substantial mucosal coverage after treatment. This review highlights the significant impact of antiresorptive drugs on osseo- integrated implants, with MRONJ identified as a leading cause of implant failure. The potential role of peri-implantitis as a trigger for MRONJ is emphasized. Regular monitoring and maintaining good periodontal health, especially within the first three years of antiresorptive drug therapy initiation, are crucial for implant success. Physicians and dentists should provide comprehensive information to patients prescribed with antiresorptive drugs, emphasizing the need for an awareness of the risks of MRONJ in the context of osseointegrated implants. A longer term of follow-up is recommended to identify and manage MRONJ around dental implants in an early manner.
PubMed: 38610856
DOI: 10.3390/jcm13072091 -
Biomedicine & Pharmacotherapy =... Aug 2023Huoluo Xiaoling Pellet (HXP), a Chinese patent medicine, is commonly administered for the treatment of treat ischemic strokes. MCPIP1, an inducible suppressor of the...
Huoluo Xiaoling Pellet (HXP), a Chinese patent medicine, is commonly administered for the treatment of treat ischemic strokes. MCPIP1, an inducible suppressor of the inflammatory response, is a regulator of microglial M2 polarization. This study aimed to explore whether HXP can promote microglial M2 polarization by upregulating MCPIP1 expression, consequently mitigating cerebral ischemic injury. Our study involved 85 Sprague-Dawley rats (weighing 250-280 g). We established middle cerebral artery occlusion (MCAO) and oxygen-glucose deprivation-reoxygenation (OGD/R) models with MCPIP1 knockdown to assess the effects of HXP on ischemic strokes. Our findings show that HXP reduced brain water content, improved neurological function, and inhibited the expression of inflammatory factors in the brain tissues of MCAO rats. The neuroprotective effects of HXP on cerebral ischemic injuries were compromised by MCPIP1 knockdown. Immunofluorescence results indicated that the expression of microglia marker Iba1 and M2 phenotypic marker CD206 was upregulated in MCAO rats and OGD/R-treated microglia. Administration of HXP significantly reduced Iba1 expression and facilitated CD206 expression, an effect that was counteracted by sh-MCPIP1 transfection. Western blotting revealed that HXP treatment augmented the expression of MCPIP1, microglial M2 marker proteins (CD206 and Arg1), and PPARγ, while reducing the expression of microglial M1 marker proteins (CD16 and iNOS) in MCAO rats and OGD/R-induced microglia. MCPIP1 knockdown suppressed HXP-mediated upregulation of MCPIP1, CD206, Arg1, and PPARγ, as well as the downregulation of CD16 and iNOS. Our findings suggest that HXP primarily ameliorates ischemic stroke through the upregulation of MCPIP1, which in turn induces microglial M2 polarization.
Topics: Rats; Animals; Microglia; Brain Ischemia; PPAR gamma; Rats, Sprague-Dawley; Infarction, Middle Cerebral Artery; Ischemic Stroke; Brain Injuries; Brain Injuries, Traumatic; Stroke
PubMed: 37236023
DOI: 10.1016/j.biopha.2023.114914 -
Journal of Advanced Veterinary and... Mar 2024This study aimed to analyze the effects of the use of binders on the physical quality and digestibility of Alabio ducks ( Borneo).
OBJECTIVES
This study aimed to analyze the effects of the use of binders on the physical quality and digestibility of Alabio ducks ( Borneo).
MATERIALS AND METHODS
Pellet binders used tapioca meal (TM) (), sago meal (SM) ( Rottb.), and sweet potato meal (SPM) () pelleted feed. Laying Alabio ducks, around 120 birds, aged 20 weeks with an average body weight of 1,426 ± 113.5 gm, were used. A fully randomized design with 4 treatments and 15 repeats was used in this study. The variables measured include the physical quality and digestibility of pellet feed. Data analysis used a Fisher test. For the distinction between treatments, the Duncan multiple-range test was conducted.
RESULTS
The finding showed that the plant-based pellet binder had a natural effect on physical properties, including pellet durability index, moisture content, threshold power, stack density, and stack compacted density. The strength of the pellet binder is seen in the durability index of TM 98.12%, SM 97.64%, and SPM 97.35%, respectively. However, these variables did not differ significantly in terms of specific gravity and stack angle. Pellet binders considerably affect the consumption of feed and vary markedly in dry matter, organic matter, and metabolizable energy digestibility.
CONCLUSION
Plant-based pellet binders influence the physical quality and digestibility of pelleted feed in Alabio ducks. TM can maintain physical quality and digestibility compared to SM and SPM as plant-based pellet binders.
PubMed: 38680798
DOI: 10.5455/javar.2024.k752 -
Aquatic Toxicology (Amsterdam,... Dec 2023Coastal tropical ecosystems provide livelihood for millions of people but are at the same time exposed to an increasing intensity of diverse anthropogenic stressors,...
Coastal tropical ecosystems provide livelihood for millions of people but are at the same time exposed to an increasing intensity of diverse anthropogenic stressors, including pollution. Nevertheless, the combined effects of pollutants on marine ecosystems are poorly understood, particularly regarding lower trophic levels (plankton) and tropical ocean. We exposed the tropical copepod Centropages velificatus to 4-5 concentrations of a heavy metal (nickel), an oil compound (pyrene) and microplastic (PET), either alone or in combination, and measured their egestion, reproduction, and mortality rates. Microplastic alone did not have any effect on pellet or egg production of copepods, whereas nickel reduced egg production rate at concentrations ≥1 µg L and pyrene reduced both egg and pellet production rates at concentrations ≥1 nM. The addition of nickel and pyrene to PET - microplastic resulted in a reduction similar to one caused by nickel or pyrene alone, suggesting an additive effect. In contrast, a combination of nickel and pyrene had a synergistic effect, with a strong reduction in survival, egg and pellet production. Our results suggest that combinations of contaminants that are commonly found in tropical coastal waters have detrimental effects on copepods-the crucial link in the pelagic food web-at lower concentrations than suggested by single stressor studies. This can have an influence on the food web productivity - the basis of fisheries that local communities rely on.
Topics: Humans; Animals; Ecosystem; Microplastics; Copepoda; Plastics; Nickel; Water Pollutants, Chemical; Pyrenes; Reproduction
PubMed: 37939499
DOI: 10.1016/j.aquatox.2023.106737 -
Environmental Science. Processes &... Aug 2023Microplastics (MPs) are emerging pollutants of global concern due to their pervasiveness, high sorption ability for persistent organic pollutants (POPs) and direct and...
Microplastics (MPs) are emerging pollutants of global concern due to their pervasiveness, high sorption ability for persistent organic pollutants (POPs) and direct and indirect toxicity to marine organisms, ecosystems, as well as humans. As one of the major coastal interfaces, beaches are considered among the most affected ecosystems by MPs pollution. The morphological characteristics of MPs (pellets and fragments) collected from four beaches along the Tunisian coast and sorbed POPs, including polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), were investigated in this study. The results showed that the MPs varied greatly in color, polymer composition and degradation degree. The color varied from colored to transparent and the most prevalent polymer identified using Raman spectroscopy was polyethylene. Scanning electron microscope (SEM) images exhibited various surface degradation features including cavities, cracks, attached diatom remains, The concentrations of ΣPCBs over all beaches ranged from 14 to 632 ng g and 26 to 112 ng g in the pellets and fragments, respectively, with a notable presence and dominance of highly-chlorinated PCBs such as CB-153 and -138. Among the OCPs, γ-HCH is the only compound detected with concentrations ranging from 0.4 to 9.7 ng g and 0.7 to 4.2 ng g in the pellets and fragments, respectively. Our findings indicate that MPs found on the Tunisian coast may pose a chemical risk to marine organisms as the concentrations of PCBs and γ-HCH in most of the analysed samples exceeded the sediment-quality guidelines (SQG), especially the effects range medium (ERM) and the probable effects level (PEL). As the first report of its kind, the information gathered in this study can serve as the baseline and starting point for future monitoring work for Tunisia and neighbouring countries, as well as for stakeholders and coastal managers in decision-making processes.
Topics: Humans; Ecosystem; Environmental Monitoring; Environmental Pollutants; Hexachlorocyclohexane; Hydrocarbons, Chlorinated; Mediterranean Sea; Microplastics; Persistent Organic Pollutants; Pesticides; Plastics; Polychlorinated Biphenyls; Tunisia; Water Pollutants, Chemical; Animals
PubMed: 37401332
DOI: 10.1039/d3em00169e -
Tissue Engineering. Part C, Methods Sep 2023Allogeneic chondrocyte therapies need to be developed to allow more individuals to be treated with a cell therapy for cartilage repair and to reduce the burden and cost...
Allogeneic chondrocyte therapies need to be developed to allow more individuals to be treated with a cell therapy for cartilage repair and to reduce the burden and cost of the current two-stage autologous procedures. Upscale manufacture of chondrocytes using a bioreactor could help provide an off-the-shelf allogeneic chondrocyte therapy with many doses being produced in a single manufacturing run. In this study, we assess a good manufacturing practice-compliant hollow-fiber bioreactor (Quantum) for adult chondrocyte manufacture. Chondrocytes were isolated from knee arthroplasty-derived cartilage ( = 5) and expanded in media supplemented with 10% fetal bovine serum (FBS) or 5% human platelet lysate (hPL) on tissue culture plastic (TCP) for a single passage. hPL-supplemented cultures were then expanded in the Quantum bioreactor for a further passage. Matched, parallel cultures in hPL or FBS were maintained on TCP. Chondrocytes from all culture conditions were characterized in terms of growth kinetics, morphology, immunoprofile, chondrogenic potential (chondrocyte pellet assays), and single telomere length analysis. Quantum expansion of chondrocytes resulted in 86.4 ± 38.5 × 10 cells in 8.4 ± 1.5 days, following seeding of 10.2 ± 3.6 × 10 cells. This related to 3.0 ± 1.0 population doublings in the Quantum bioreactor, compared with 2.1 ± 0.6 and 1.3 ± 1.0 on TCP in hPL- and FBS-supplemented media, respectively. Quantum- and TCP-expanded cultures retained equivalent chondropotency and mesenchymal stromal cell marker immunoprofiles, with only the integrin marker, CD49a, decreasing following Quantum expansion. Quantum-expanded chondrocytes demonstrated equivalent chondrogenic potential (as assessed by ability to form and maintain chondrogenic pellets) with matched hPL TCP populations. hPL manufacture, however, led to reduced chondrogenic potential and increased cell surface positivity of integrins CD49b, CD49c, and CD51/61 compared with FBS cultures. Quantum expansion of chondrocytes did not result in shortened 17p telomere length when compared with matched TCP cultures. This study demonstrates that large numbers of adult chondrocytes can be manufactured in the Quantum hollow-fiber bioreactor. This rapid, upscale expansion does not alter chondrocyte phenotype when compared with matched TCP expansion. Therefore, the Quantum provides an attractive method of manufacturing chondrocytes for clinical use. Media supplementation with hPL for chondrocyte expansion may, however, be unfavorable in terms of retaining chondrogenic capacity.
Topics: Adult; Humans; Chondrocytes; Cartilage; Cells, Cultured; Extracellular Matrix; Hematopoietic Stem Cell Transplantation; Cell Differentiation; Cell Proliferation
PubMed: 37395490
DOI: 10.1089/ten.TEC.2023.0037 -
Current Environmental Health Reports Jun 2024Almost 3 billion people worldwide use solid fuel for cooking and heating. This review examines (i) household energy practices and infrastructures and their influence on... (Review)
Review
PURPOSE OF REVIEW
Almost 3 billion people worldwide use solid fuel for cooking and heating. This review examines (i) household energy practices and infrastructures and their influence on fuel usage in different contexts; (ii) barriers in adoption of household clean energy technologies and uses in diverse settings and population groups and (iii) potential air pollution exposure reduction in homes through using processed fuel.
RECENT FINDINGS
Population health burden from solid fuel combustion-derived particulate air pollution has been estimated in several low- and middle-income countries. However, such studies have not been carried out in high income countries (e.g., UK). Irrespective of the region, fuel prices are the most dominant factor influencing the choice of fuel. Laboratory studies suggest processed fuel - pellets and briquettes - reduce particulate matter emissions by 70-80% and can be a promising alternative. Adoption of clean fuels for domestic energy needs facilitates progress towards five of the UN Sustainable Development Goals (SDGs). There is evidence that a variety of factors, including cost savings, encourage and hinder such uptake. These factors include price fluctuations, expenses, and the usage of clean fuels. Due to their distinct development scenarios, more expansive policy frameworks, and political economies of energy, these determinants are localized in character and differ significantly amongst economies. Therefore, in order to create innovative plans for the adoption of clean fuel use, strategies centred on local settings must be developed while keeping broad socio-technical and socio-economic issues in mind. Solid fuel processing - pelletization and briquetting - have the potential to reach Liquefied Petroleum Gas (LPG)-like emissions, and could be a potential strategy to mitigate exposure to household air pollution.
Topics: Humans; Cooking; Air Pollution, Indoor; Heating; Particulate Matter; Housing; Air Pollutants
PubMed: 38468075
DOI: 10.1007/s40572-024-00438-7