Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 98
Filtrar
1.
Biomater Adv ; 167: 214060, 2024 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-39486241

RESUMO

Bone metastases related to breast and prostate cancer present with multiple challenges and skeletal related events like fragility fractures impair the quality of life of the patients significantly. To determine local alterations in bone material quality with bone metastasis, we subjected murine tibial specimens, generated after intratibial injections of either RM1 prostate cancer cells or EO771 breast cancer cells into male and female mice respectively, to high-resolution imaging modalities. Small and wide-angle X-ray scattering showed unaltered mineral characteristics in the more osteosclerotic prostate cancer model, while the quantification of calcium weight percentage via backscattered electron microscopy determined minor differences along the perilacunar bone matrix. Further analyses of mineral and collagen characteristics were performed using Raman spectroscopy and focused ion beam electron microscopy. Our study indicates that alterations in nanochannel properties occur due to the presence of bone seeking tumor cells with more prevalent nanopores in the perilacunar matrix.

2.
Int J Biol Macromol ; 281(Pt 4): 136633, 2024 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-39419150

RESUMO

The utilization of agricultural by-products for the synthesis of hybrid nanomaterials represents an environmentally sustainable approach. This research aims to comprehensively investigate high-performance silver and copper nanoparticles hybrid materials based on carboxymethyl-modified cellulose / lignin derived from rice husks (CMC / CML-AgNPs and CMC / CML-CuONPs) and apply them for antimicrobial activities. CMC / CML was used to reduce Ag / Cu cations to the atomic level and then efficiently stabilize Ag / CuO nanoparticles, an eco-friendly method and sustainable development. The hybrid nanomaterials were successfully synthesized with spherical shapes and particle sizes ranging from 4 to 16 nm. The diffraction peaks at 38.46°, 46.57°, 64.93°, and 77.55° were ascribed to the face-centered cubic crystal lattice (111), (200), (220), and (311) of silver nanoparticles in the CMC / CML-AgNPs. The peaks were 32.26°, 46.06°, 52.16°, 61.71°, 63.80°, and 71.23° associating with the (110,20-2), (112), (11-3), (310), and (221) plane orientations of CuO nanoparticles. The proposed materials demonstrated highly efficient antimicrobial performances. Particularly, CMC-AgNPs and CML-CuONPs exhibited an inhibitory capability of up to 100 % against E. coli and S. aureus within 72 h. Simultaneously, the antifungal results showed that hybrid nanomaterials have a better ability to inhibit the A. niger than A. flavus fungus. When experimenting on peanut seeds, hybrid nanomaterials showed an inhibitory capability of up to 99.0 % against A. niger. IC50 values of the hybrid nanomaterials range from 0.872 mg/mL to 1.188 mg/mL, confirming that these materials are non-cytotoxic. These materials exhibit significant stability and enduring antimicrobial efficacy, making them ideal for sustainable development of various antibacterial and antifungal blocks for the near future.

3.
RSC Adv ; 14(45): 33267-33280, 2024 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-39434988

RESUMO

The silver nanoparticles-sodium alginate-chitosan (AgNPs-Alg-Chi) nanocomposite film is a compelling material with demonstrated antibacterial efficacy against various pure bacterial strains. However, its potential cytotoxicity at elevated Ag doses warrants investigation. There is a notable dearth of studies assessing its antibacterial effectiveness against clinically relevant bacterial strains, notably Cutibacterium acnes. This study aims to assess the antibacterial efficacy of the low-dose AgNPs-Alg-Chi nanocomposite films on both pure bacterial strains and strains isolated from clinical samples obtained from 65 acne patients. The films were synthesized using green methods, incorporating kumquat (Citrus japonica) extract as a silver ion-reducing agent. The material characterization methods include UV-Vis and FTIR spectroscopies, SEM-EDS, XPS, cell culture, and MTT assay. We successfully fabricated the AgNPs-Alg-Chi nanocomposite films with a low-loading dose of Ag NPs (≤11 µg mL-1, and 37.8 ± 11.5 nm in size). The AgNPs-Alg-Chi nanocomposite film demonstrated comparable antibacterial efficacy to the AgNPs-Chi solution, with MIC values ranging from 3.67 to 5.50 µg mL-1 (p > 0.05) across all strains. Importantly, the AgNPs-Alg-Chi films demonstrated excellent biocompatibility with human keratinocytes (HaCaT cells), maintaining cell viability above 70%. The present AgNPs-Alg-Chi nanocomposite films synthesized by a green approach demonstrated potent antibacterial activity, making them promising for further development into suitable products for human use.

4.
Heliyon ; 10(18): e37860, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39315126

RESUMO

The study was carried out with the goal of synthesizing composite bead of cellulose, chitosan functionalized by sodium alginate using as an efficient and applicable adsorbent for methylene blue removal. Fabricating parameters of the material synthesis process like cellulose mass, sodium hydroxide concentration, immersing time and sodium alginate concentration were assessed in detail. The dye adsorption performance in water under the influence of pH, contact time, dye initial concentration, the material mass, shaking speed, temperature was also thoroughly evaluated. The results of advanced analyses showed that the beads were successfully synthesized with a rough surface and mesoporous structure. The adsorption isotherm and adsorption kinetics of dye adsorption process exhibited that the process was consistent with the Freundlich adsorption isotherm and the pseudo-second-order kinetic model, indicating a favorable physical adsorption process with multilayer of the dye on the adsorbent surface. The intra-particle diffusion model showed the strong dye adsorption by the beads occurred during the first two and half hours. The adsorbent could maintain its adsorption performance of 86 % for three times of regeneration. Finally, this study provided a recyclable and effective adsorbent for dyes separation from water.

5.
JAMA Oncol ; 10(9): 1237-1244, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38990578

RESUMO

Importance: There has been an increasing trend of using noncigarette products, including waterpipe tobacco (WTP), worldwide. While cigarette smoking is a well-established risk factor for numerous cancers, little is known about the association between WTP smoking and cancer mortality. Objective: To assess the association between WTP smoking and risk of cancer mortality in Vietnam. Design, Setting, and Participants: This cohort study was based on data from the Hanoi Prospective Cohort Study, an ongoing study with a median (range) follow-up of 11.0 (0.1-11.6) years for participants aged 15 years or older in Northern Vietnam from 2007 through 2019. Data were analyzed from June 1 to September 1, 2023. Exposures: Tobacco smoking and WTP smoking statuses. Main Outcomes and Measures: Overall and site-specific cancer mortality. Cox proportional regression models were used to calculate the hazard ratio (HR) and 95% CIs for the associations between WTP smoking alone, cigarette smoking alone, and dual WTP and cigarette smoking and the risk of cancer death. Results: A total of 554 cancer deaths were identified among the 39 401 study participants (mean [SD] age, 40.4 [18.8] years; 20 616 females [52.3%]). In multivariable models, compared with never smokers, ever smokers had a significantly increased risk of cancer mortality (HR, 1.87; 95% CI, 1.48-2.35). Exclusive WTP smokers had the highest risk of cancer mortality compared with never smokers (HR, 2.66; 95% CI, 2.07-3.43). Risk of cancer mortality was higher for dual smokers of WTP and cigarettes (HR, 2.06; 95% CI, 1.53-2.76) than for exclusive cigarette smokers (HR, 1.86; 95% CI, 1.41-2.45). As most smokers (95.6% [8897 of 9312]) were male, these patterns were more apparent in male participants. Compared with never smokers, exclusive WTP smoking among males was associated with an elevated risk of death from liver cancer (HR, 3.92; 95% CI, 2.25-6.85), lung cancer (HR, 3.49; 95% CI, 2.08-5.88), nasopharyngeal carcinoma (HR, 2.79; 95% CI, 1.27-6.12), and stomach cancer (HR, 4.11; 95% CI, 2.04-8.27). For exclusive WTP smokers, the risk of cancer mortality was highest among those who smoked 11 to 15 sessions per day (HR, 3.42; 95% CI, 2.03-5.75), started smoking at age 26 to 30 years (HR, 4.01; 95% CI, 2.63-6.11), smoked for 9 to 20 years (HR, 4.04; 95% CI, 2.16-7.56), and smoked 61 to 160 sessions annually (HR, 3.68; 95% CI, 2.38-5.71). For males, the risk of cancer death was lower for those who had quit smoking for more than 10 years, compared with those who quit smoking within 1 year (HR, 0.27; 95% CI, 0.11-0.66; P for trend < .001). Conclusion and Relevance: In this cohort study in Vietnam, WTP smoking alone or in combination with cigarette smoking was associated with an increased risk of cancer death due to liver cancer, lung cancer, nasopharyngeal carcinoma, and stomach cancer. A tailored program to control WTP smoking is warranted in Vietnam and low- and middle-income countries with a high prevalence of smoking and modest resources to address smoking-related issues.


Assuntos
Neoplasias , Humanos , Masculino , Feminino , Adulto , Neoplasias/mortalidade , Neoplasias/epidemiologia , Pessoa de Meia-Idade , Vietnã/epidemiologia , Fatores de Risco , Estudos Prospectivos , Fumar Cachimbo de Água/efeitos adversos , Fumar Cachimbo de Água/epidemiologia , Tabaco para Cachimbos de Água/efeitos adversos , Fumar Tabaco/efeitos adversos , Fumar Tabaco/epidemiologia , Adulto Jovem , Adolescente
6.
ACS Omega ; 9(25): 27710-27721, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38947784

RESUMO

In this report, we introduce a novel idea to prepare a redox additive in a gel polymer electrolyte system of PVA-ZnSO4-H2SO4 based on zinc-carbon battery recycling. Here, zinc cans from spent zinc-carbon batteries are dissolved completely in 1 M H2SO4 to obtain a redox additive in an aqueous electrolyte of ZnSO4-H2SO4. Moreover, carbon nanoparticles and graphene nanosheets were synthesized from carbon rod and carbon powder from spent zinc-carbon batteries by only one step of washing and electrochemical exfoliation, respectively, which have good electrochemical capability. The three-electrode system using a ZnSO4-H2SO4 electrolyte with carbon nanoparticles and graphene nanosheets as working electrodes shows high electrochemical adaptability, which points out its promising application in supercapacitor devices. Thus, the symmetrical solid-state supercapacitor devices based on the sandwich structure of graphene nanosheets/PVA-ZnSO4-H2SO4/graphene nanosheets illustrated the highest energy density of 39.17 W h kg-1 at a power density of 1700 W kg-1. While symmetrical devices based on carbon nanoparticles/PVA-ZnSO4-H2SO4/carbon nanoparticles exhibited a maximum energy density of 35.65 W h kg-1 at a power density of 1700 W kg-1. Moreover, these devices illustrate strong durability after 5000 cycles, with approximately 90.2% and 73.1% remaining, respectively. These results provide a promising strategy for almost completely recycling zinc-carbon batteries, one of the most popular dry batteries.

7.
ACS Omega ; 9(21): 22543-22556, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38826542

RESUMO

In this paper, carbon materials, including graphene nanosheets and carbon nanoparticles, were prepared from spent zinc-carbon batteries by the following two simple methods: electrochemical exfoliation and ultrasonication. Here, graphene nanosheets were synthesized by electrochemical exfoliation in 0.5 M H2SO4 by using a direct current power supply with two carbon rods from spent zinc-carbon batteries. Carbon nanoparticles were prepared by fast ultrasonication in a low-cost, green solution of DI water and ethanol. Graphene nanosheets in this study have high quality, large scale, and good electrochemical ability, while carbon nanoparticles have a unique nanosize and a good specific surface area. These carbon materials were applied for electrochemical measurements for supercapacitor studies and showed excellent stability at different temperatures. Moreover, electric double-layer capacitor devices based on graphene nanosheets and carbon nanoparticles were also used in electrochemical studies with strong stability and good electrochemical capability.

8.
Micromachines (Basel) ; 15(6)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38930684

RESUMO

The development of nanocomposite photocatalysts with high photocatalytic activity, cost-effectiveness, a simple preparation process, and scalability for practical applications is of great interest. In this study, nanocomposites of TiO2 Degussa P25 nanoparticles/activated carbon (TiO2/AC) were prepared at various mass ratios of (4:1), (3:2), (2:3), and (1:4) by a facile process involving manual mechanical pounding, ultrasonic-assisted mixing in an ethanol solution, paper filtration, and mild thermal annealing. The characterization methods included XRD, SEM-EDS, Raman, FTIR, XPS, and UV-Vis spectroscopies. The effects of TiO2/AC mass ratios on the structural, morphological, and photocatalytic properties were systematically studied in comparison with bare TiO2 and bare AC. TiO2 nanoparticles exhibited dominant anatase and minor rutile phases and a crystallite size of approximately 21 nm, while AC had XRD peaks of graphite and carbon and a crystallite size of 49 nm. The composites exhibited tight decoration of TiO2 nanoparticles on micron-/submicron AC particles, and uniform TiO2/AC composites were obtained, as evidenced by the uniform distribution of Ti, O, and C in an EDS mapping. Moreover, Raman spectra show the typical vibration modes of anatase TiO2 (e.g., E1g(1), B1g(1), Eg(3)) and carbon materials with D and G bands. The TiO2/AC with (4:1), (3:2), and (2:3) possessed higher reaction rate constants (k) in photocatalytic degradation of methylene blue (MB) than that of either TiO2 or AC. Among the investigated materials, TiO2/AC = 4:1 achieved the highest photocatalytic activity with a high k of 55.2 × 10-3 min-1 and an MB removal efficiency of 96.6% after 30 min of treatment under UV-Vis irradiation (120 mW/cm2). The enhanced photocatalytic activity for TiO2/AC is due to the synergistic effect of the high adsorption capability of AC and the high photocatalytic activity of TiO2. Furthermore, TiO2/AC promotes the separation of photoexcited electron/hole (e-/h+) pairs to reduce their recombination rate and thus enhance photocatalytic activity. The optimal TiO2/AC composite with a mass ratio of 4/1 is suggested for treating industrial or household wastewater with organic pollutants.

10.
Heliyon ; 10(11): e32209, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38912489

RESUMO

Alzheimer's disease (AD) is a brain illness that causes cognitive impairment in the elderly, especially females, as a result of genetics, hormones, and life experiences. It becomes more severe with age and is associated with cardiovascular disease, hypertension, and diabetes. Beta-amyloid plaques and hyper phosphorylated Tau protein buildup are common clinical findings. Misfiling of amyloid precursor protein (APP) and Amyloid beta peptide (Aß) proteins contributes to Alzheimer's disease. Enzyme Acetylcholinesterase enzyme interacts with amyloid-beta, enhancing its accumulation in insoluble plaques, leading to successful treatment for Alzheimer's disease primarily based on lowering this enzyme. Treatments include using the Rivastigmine for mild, moderate, or severe Alzheimer's disease, which inhibits acetylcholinesterase, but may cause side effects; Solanine derivatives, nightshade toxin, it is cholinesterase inhibitory, may mitigate Alzheimer's illness is progressing. In this research utilized a molecular docking program, which is a computer's computational ability to determine the optimal position for a specific compound to bind to a protein or target, forming a target-ligand complex and displaying biological activity and aiding in the development of effective anti-AD treatments and understanding AD pathological mechanisms. The study examined complexes of 3LII (Acetylcholinesterase receptor) in the A and B chain with Solanine and Rivastigmine derivatives, using an in-silico approach. PyRx default sorter was used to improve docking accuracy. Four compounds were selected based on their higher binding affinities in chain A and B. The results showed that Solanine derivatives (alpha-Solanine, Beta1-Solanine and Beta2-Solanine) have higher binding strength (-9.0,-9.3 and -8.6) than Rivastigmine (-7.2) in chain A, and also the binding strength was high for the Solanine derivatives (alpha-Solanine, Beta1-Solanine, and Beta2-Solanine) (-9.0,-8.8 and -8.9) is higher than Rivastigmine (-6.0) in the chain B. Solanine derivatives showed higher binding strength with acetylcholinesterase, potentially for to reduce the progression of the disease.

11.
J Environ Manage ; 359: 121058, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38714036

RESUMO

Water pollution remains a pressing environmental issue, with diverse pollutants such as heavy metals, pharmaceuticals, dyes, and aromatic hydrocarbon compounds posing a significant threat to clean water access. Historically, biomass-derived activated carbons (ACs) have served as effective adsorbents for water treatment, owing to their inherent porosity and expansive surface area. Nanocomposites have emerged as a means to enhance the absorption properties of ACs, surpassing conventional AC performance. Biomass-based activated carbon nanocomposites (ACNCs) hold promise due to their high surface area and cost-effectiveness. This review explores recent advancements in biomass-based ACNCs, emphasizing their remarkable adsorption efficiencies and paving the way for future research in developing efficient and affordable ACNCs. Leveraging real-time communication for ACNC applications presents a viable approach to addressing cost concerns.


Assuntos
Carvão Vegetal , Frutas , Nanocompostos , Verduras , Purificação da Água , Nanocompostos/química , Carvão Vegetal/química , Purificação da Água/métodos , Frutas/química , Adsorção , Verduras/química , Poluentes Químicos da Água/química , Biomassa
12.
Microb Genom ; 10(5)2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38739115

RESUMO

Aeromonas spp. are commonly found in the aquatic environment and have been responsible for motile Aeromonas septicemia (MAS) in striped catfish, resulting in significant economic loss. These organisms also cause a range of opportunistic infections in humans with compromised immune systems. Here, we conducted a genomic investigation of 87 Aeromonas isolates derived from diseased catfish, healthy catfish and environmental water in catfish farms affected by MAS outbreaks in eight provinces in Mekong Delta (years: 2012-2022), together with 25 isolates from humans with bloodstream infections (years: 2010-2020). Genomics-based typing method precisely delineated Aeromonas species while traditional methods such as aerA PCR and MALDI-TOF were unable identify A. dhakensis. A. dhakensis was found to be more prevalent than A. hydrophila in both diseased catfish and human infections. A. dhakensis sequence type (ST) 656 followed by A. hydrophila ST251 were the predominant virulent species-lineages in diseased catfish (43.7 and 20.7 %, respectively), while diverse STs were found in humans with bloodstream infections. There was evidence of widespread transmission of ST656 and ST251 on striped catfish in the Mekong Delta region. ST656 and ST251 isolates carried a significantly higher number of acquired antimicrobial resistance (AMR) genes and virulence factors in comparison to other STs. They, however, exhibited several distinctions in key virulence factors (i.e. lack of type IV pili and enterotoxin ast in A. dhakensis), AMR genes (i.e. presence of imiH carbapenemase in A. dhakensis), and accessory gene content. To uncover potential conserved proteins of Aeromonas spp. for vaccine development, pangenome analysis has unveiled 2202 core genes between ST656 and ST251, of which 78 proteins were in either outer membrane or extracellular proteins. Our study represents one of the first genomic investigations of the species distribution, genetic landscape, and epidemiology of Aeromonas in diseased catfish and human infections in Vietnam. The emergence of antimicrobial resistant and virulent A. dhakensis strains underscores the needs of enhanced genomic surveillance and strengthening vaccine research and development in preventing Aeromonas diseases in catfish and humans, and the search for potential vaccine candidates could focus on Aeromonas core genes encoded for membrane and secreted proteins.


Assuntos
Aeromonas , Peixes-Gato , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Sepse , Animais , Peixes-Gato/microbiologia , Vietnã/epidemiologia , Aeromonas/genética , Aeromonas/isolamento & purificação , Aeromonas/classificação , Aeromonas/patogenicidade , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Infecções por Bactérias Gram-Negativas/epidemiologia , Humanos , Sepse/microbiologia , Sepse/veterinária , Sepse/epidemiologia , Doenças dos Peixes/microbiologia , Filogenia , Genômica , Genoma Bacteriano , Fatores de Virulência/genética , Antibacterianos/farmacologia
13.
Int J Biol Macromol ; 268(Pt 2): 131760, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38663693

RESUMO

In the adsorption process for wastewater treatment, the adsorbent plays an important role. A composite adsorptive material composed of graphitic carbon nitride and agar-derived porous carbon (CNPC) was fabricated from simple precursors (melamine, thiourea, and agar) and through a facile procedure with different melamine and thiourea ratios. Characterization of CNPC proved a successful formation of a porous structure consisting of mesopores and macropores, wherein CNPC holds distinctive electrochemical (lowered resistance and higher specific capacity) and photochemical properties (lowered bandgap to 2.33 eV) thanks to the combination of graphitic carbon nitride (CN) and agar-derived porous carbon (PC). Inheriting the immanent nature, CNPC was subjected to the adsorption of methylene blue (MB) dye in an aqueous solution. The highest adsorption capacity was 133 mg/g for CNPC-4 which was prepared using a melamine to thiourea ratio of 4:4 - equivalent to the removal rate of 53.2 % and following the pseudo-I-order reaction rate. The effect of pH points out that pH 7 and 9 were susceptible to maximum removal and pretreatment is not required while the optimal ratio of 7.5 mg of MB and 30 mg of material was also determined to yield the highest performance. Furthermore, the reusability of the material for three consecutive cycles was evaluated based on two methods pyrolysis at 200 °C and photocatalytic degradation by irradiation under visible light. In general, the photocatalytic regeneration pathway is more ample and efficient than pyrolysis in terms of energy efficiency (saving energy over 10 times) and adsorption capacity stability. As a whole, the construction of accessible regenerative and stable adsorbent could be a venturing step into the sustainable development spearhead for industries.


Assuntos
Ágar , Grafite , Azul de Metileno , Poluentes Químicos da Água , Adsorção , Grafite/química , Porosidade , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Azul de Metileno/química , Ágar/química , Purificação da Água/métodos , Triazinas/química , Recuperação e Remediação Ambiental/métodos , Carbono/química , Águas Residuárias/química , Concentração de Íons de Hidrogênio , Compostos de Nitrogênio/química , Cinética , Tioureia/química
14.
Nanotechnology ; 35(26)2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38527359

RESUMO

A novel, rapid, and facile method for one-step sonoelectrochemical synthesis of zinc oxide nanoparticles (UEZ) was introduced in this study. The optimum operating parameters have been selected at a voltage of 7.5 V, KCl concentration of 0.5 M, and the reaction time of 60 min. The as-prepared UEZ were characterized by XRD, SEM, and HRTEM. It was found that the UEZ has a hexagonal wurtzite structure with high crystalline quality, good purity, a size range of 30-100 nm, and good photocatalytic degradation of methylene blue. This work provides a facile route for large-scale synthesizing ZnO nanoparticles via anodization.

15.
Environ Monit Assess ; 196(4): 395, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38528293

RESUMO

This study assessed the accumulation levels and ecological risks associated with seven heavy metals (As, Pb, Cd, Hg, Cu, Cr, Zn) in the surface sediments of the Bong Mieu River in Quang Nam Province, Vietnam. The sampling encompassed 10 locations (S1-S10), considering areas both impacted and less impacted by gold mining activities. The findings revealed elevated levels of heavy metal pollution and associated ecological risks attributable to gold mining. Heavy metal content varied within specific ranges: As (70.6-341.2 mg/kg), Pb (216.3-504.1 mg/kg), Hg (0.138-0.252 mg/kg), Cd (0.91-1.51mg/kg), Cu (18.3-45.5 mg/kg), Cr (10.5-19.1 mg/kg), and Zn (49.3-84.1 mg/kg). Among these elements, Hg, Cu, Cr, Zn, and Cd adhered to the acceptable limits of VNTR 43:2017/MONRE (VNTR 43:2017/MONRE: National Technical Regulation/Ministry of Natural Resources and Environment of Vietnam). However, As and Pb content at all locations exceeded these limits significantly, with As being 4.1-20 times higher and Pb 2.3-5.5 times higher. The pollution of Pb and As was attributed to waste discharge from gold mining activities, which carry substantial amounts of these metals in various forms. The Igeo indicated heavy pollution of As and Pb in the sediments. Ecological risk factors were ranked as follows: E r i (As) > E r i (Pb) > E r i (Hg) > E r i (Cd) > E r i (Cu) > E r i (Cr) > E r i (Zn). The potential ecological risk (RI) due to combined heavy metal impact varied across locations, with S2 > S8 > S9 > S6 > S7 > S10 > S1 > S3 > S4 > S5, exhibiting low to moderate risk (RI values ranging from 73.4 to 252.8). The study area demonstrated high contamination levels for As and Pb, coupled with low to moderate potential ecological risks.


Assuntos
Mercúrio , Metais Pesados , Poluentes Químicos da Água , Rios , Vietnã , Cádmio , Chumbo , Medição de Risco , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Sedimentos Geológicos , Metais Pesados/análise , Ouro , China
16.
Int J Epidemiol ; 53(1)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37843876

RESUMO

BACKGROUND: Despite an increasing proportion of smokers who use non-cigarette products, the harmfulness of these is inconsistent. This study aimed to evaluate the impact of waterpipe tobacco (WTP) smoking on all-cause mortality. METHODS: A prospective cohort study followed up on 35 646 participants from 2007 to 2019 in Northern Viet Nam. Data for each type of cigarette and WTP smoking were collected based on demographic lifestyle and semi-quantitative food frequency questionnaires. Smokers were categorized as current smokers and former smokers who were lifetime ever smokers but stopped smoking >6 months before the interview. Data on all-cause mortality (2449 deaths) were obtained from medical records at the state health facilities. The hazard ratios (HRs) and 95% CIs for mortality were estimated using a Cox proportional-hazards model. RESULTS: Compared with non-smokers, ever smokers had a higher all-cause mortality risk (HR = 1.29, 95% CI = 1.16-1.43). Current WTP (HR = 1.37, 95% CI = 1.19-1.57), current cigarette (HR = 1.40, 95% CI = 1.22-1.60) and former WTP smokers (HR = 1.39, 95% CI = 1.10-1.76) showed an elevated risk of dying. The mortality risk was significantly elevated in dual smokers using WTP and cigarettes (HR = 1.55, 95% CI = 1.35-1.79) and exclusive WTP smokers (HR = 1.38, 95% CI = 1.21-1.57). Elevated risk was observed for the main targeted attractions of cancer, diabetes and heart diseases. Smoking cessation of >10 years decreased the risk of all-cause mortality (HR = 0.61, 95% CI = 0.44-0.85) and cancer (HR = 0.24, 95% CI = 0.11-0.52). CONCLUSIONS: WTP smoking increases the risk of all-cause mortality. A unique programme to control exposure to WTP should be a high priority in Viet Nam and other countries.


Assuntos
Neoplasias , Abandono do Hábito de Fumar , Tabaco para Cachimbos de Água , Humanos , Estudos Prospectivos , Fumar/efeitos adversos , Fumar/epidemiologia
17.
Sci Total Environ ; 907: 168142, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-37898211

RESUMO

Constructed wetlands (CWs) are a widely utilized nature-based wastewater treatment method for various effluents. However, their application has been more focused on pilot and full-scale CWs with substantial surface areas and extended operation times, which hold greater relevance in practical scenarios. This study used kinetics, linear regression (LR), and machine learning (ML) models to estimate effluent ammonium in pilot and full-scale CWs. From screening 1476 papers, 24 pilot and full-scale CW studies were selected to extract data containing 15 features and 975 data points. Nine models were fit to this data, revealing that linear models were less effective in capturing CW effluent compared to nonlinear ML algorithms. For training data, the Monod kinetic model predicted the poorest performance with an RMSE of 41.84 mg/L and R2 of 0.34, followed by simple LR (RMSE 24.29 mg/L and R2 0.77) and multiple LR (RMSE 22.63 mg/L and R2 0.80). In contrast, Cubist and Random Forest achieved high performances, with an average RMSE of 12.01 ± 5.38 and an average R2 of 0.93 ± 0.07 for Cubist, and an average RMSE of 15.94 ± 10.69 and an average R2 of 0.91 ± 0.08 for RF. The trained Random Forest performed the best for new data, with an R2 of 0.93 and RMSE of 13.48 mg/L. This ML-based model is a valuable tool for efficiently estimating effluent ammonium concentration in pilot and full-scale CWs, thereby facilitating the design of systems.

18.
Heliyon ; 9(11): e21041, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37928005

RESUMO

The main aim of this study is to figure out how well cryptand-2.2.1 (C 2.2.1) and cryptand-2.1.1 (C 2.1.1) macrocyclic compounds (MCs) work as novel extractants for scandium (Sc) by using an artificial neural network (ANN) models in MATLAB software. Moreover, C2.2.1 and C2.1.1 have never been evaluated to recover Sc. The independent variables impacting the extraction process (concentration of MC, concentration of Sc, pH, and time), and a nonlinear autoregressive network with exogenous input (NARX) and feed-forward neural network (FFNN) models were used to estimate their optimum values. The greatest obstacle in the selective recovery process of the REEs is the similarity in their physicochemical properties, specifically their ionic radius. The recovery of Sc from the aqueous solution was experimentally evaluated, then the non-linear relationship between those parameters was predictively modeled using (NARX) and (FFNN). To confirm the extraction and stripping efficiency, an atomic absorption spectrophotometer (AAS) was employed. The results of the extraction investigations show that, for the best conditions of 0.008 mol/L MC concentration, 10 min of contact time, pH 2 of the aqueous solution, and 75 mg/L Sc initial concentration, respectively, the C 2.1.1 and C 2.2.1 extractants may reach 99 % of Sc extraction efficiency. Sc was recovered from a multi-element solution of scandium (Sc), yttrium (Y), and lanthanum (La) under these circumstances. Whereas, at a concentration of 0.3 mol/L of hydrochloric acid, the extraction of Sc was 99 %, as opposed to Y 10 % and La 7 %. The Levenberg-Marquardt training algorithm had the best training performance with an mean-squared-error, MSE, of 5.232x10-6 and 6.1387x10-5 for C 2.2.1 and C 2.1.1 respectively. The optimized FFNN architecture of 4-10-1 was constructed for modeling recovery of Sc. The extraction process was well modeled by the FFNN with an R2 of 0.999 for the two MC, indicating that the observed Sc recovery efficiency consistent with the predicted one.

19.
Heliyon ; 9(11): e21345, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37954383

RESUMO

The lateritic ore drying in the Cuban nickel producing industry is realized within flighted rotary dryers. In this investigation, performance indicators in regards to transfer of momentum, heat and mass were evaluated. The dryers operate in a concurrent configuration with combustion gas, at a productivity between 40 t h-1 and 50 t h-1. The distribution function of the residence time (RTD) was best fitted to a model of a multi-branch tanks-in-series system, theoretical residence time was 51 ± 2 min and experimental mean residence time 61 min, at a rate of 45 t h-1 and hydraulic efficiency 1.23, due to the presence of dead-zoon. Mass and energy balance was made following a "black box" model, as results, the specific fuel consumption was 27.25 ± 0.25 kg fuel t-1 of wet ore, specific energy consumption 79.66 ± 0.95 kg fuel t-1 of H2O evaporated, energy efficiency 97.28 ± 0.01 %, thermal efficiency 66.88 ± 0.71 % and drying efficiency 98.77 ± 0.12 %. Mathematical modelling was made using a system of differential equations, the rate of drying in falling rate period was estimated by Arrhenius equation, then, temperature profile and ore moisture content along the dryer was simulated. The model provided a successful predictive performance; for an inlet gas temperature between 850 °C and 900 °C, the ore moisture was reduced form 33.0 % (wet basis) to a range depending on the dryer productivity, from 3.0 % to 7.1 %. Designing a computerized system that implements these algorithms can benefit on efficiency and productivity of the production plant.

20.
Micromachines (Basel) ; 14(10)2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37893316

RESUMO

In this study, samarium (Sm-10at%)-doped BiFeO3 (SmBFO) thin films were grown on platinum-coated glass substrates using pulsed laser deposition (PLD) to unveil the correlation between the microstructures and nanomechanical properties of the films. The PLD-derived SmBFO thin films were prepared under various oxygen partial pressures (PO2) of 10, 30, and 50 mTorr at a substrate temperature of 600 °C. The scanning electron microscopy analyses revealed a surface morphology consisting of densely packed grains, although the size distribution varied with the PO2. X-ray diffraction results indicate that all SmBFO thin films are textured and preferentially oriented along the (110) crystallographic orientation. The crystallite sizes of the obtained SmBFO thin films calculated from the Scherrer and (Williamson-Hall) equations increased from 20 (33) nm to 25 (52) nm with increasing PO2. In addition, the nanomechanical properties (the hardness and Young's modulus) of the SmBFO thin films were measured by using nanoindentation. The relationship between the hardness and crystalline size of SmBFO thin films appears to closely follow the Hall-Petch equation. In addition, the PO2 dependence of the film microstructure, the crystallite size, the hardness, and Young's modulus of SmBFO thin films are discussed.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA