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1.
Small ; : e2309122, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38377285

RESUMO

This research designs a triphasic Ni2 P-Ni12 P5 -Ru heterostructure with amorphous interface engineering strongly coupled by a cobalt nano-surface (Co@Nim Pn -Ru) to form a hierarchical 3D interconnected architecture. The Co@Nim Pn -Ru material promotes unique reactivities toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media. The material delivers an overpotential of 30 mV for HER at 10 mA cm-2 and 320 mV for OER at 50 mA cm-2 in freshwater. The electrolyzer cell derived from Co@Nim Pn -Ru(+,-) requires a small cell voltage of only 1.43 V in alkaline freshwater or 1.44 V in natural seawater to produce 10 mA cm-2 at a working temperature of 80 °C, along with high performance retention after 76 h. The solar energy-powered electrolyzer system also shows a prospective solar-to-hydrogen conversion efficiency and sufficient durability, confirming its good potential for economic and sustainable hydrogen production. The results are ascribed to the synergistic effects by an exclusive combination of multi-phasic crystalline Ni2 P, Ni12 P5 , and Ru clusters in presence of amorphous phosphate interface attached onto cobalt nano-surface, thereby producing rich exposed active sites with optimized free energy and multi open channels for rapid charge transfer and ion diffusion to promote the reaction kinetics.

2.
Micromachines (Basel) ; 14(9)2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37763889

RESUMO

Sensor technologies have been core features for various wearable electronic products for decades. Their functions are expected to continue to play an essential role in future generations of wearable products. For example, trends in industrial, military, and security applications include smartwatches used for monitoring medical indicators, hearing devices with integrated sensor options, and electronic skins. However, many studies have focused on a specific area of the system, such as manufacturing processes, data analysis, or actual testing. This has led to challenges regarding the reliability, accuracy, or connectivity of components in the same wearable system. There is an urgent need for studies that consider the whole system to maximize the efficiency of soft sensors. This study proposes a method to fabricate a resistive pressure sensor with high sensitivity, resilience, and good strain tolerance for recognizing human motion or body signals. Herein, the sensor electrodes are shaped on a thin Pyralux film. A layer of microfiber polyesters, coated with carbon nanotubes, is used as the bearing and pressure sensing layer. Our sensor shows superior capabilities in respiratory monitoring. More specifically, the sensor can work in high-humidity environments, even when immersed in water-this is always a big challenge for conventional sensors. In addition, the embedded random forest model, built for the application to recognize restoration signals with high accuracy (up to 92%), helps to provide a better overview when placing flexible sensors in a practical system.

3.
Micromachines (Basel) ; 14(7)2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37512722

RESUMO

Soft sensors are attracting much attention from researchers worldwide due to their versatility in practical projects. There are already many applications of soft sensors in aspects of life, consisting of human-robot interfaces, flexible electronics, medical monitoring, and healthcare. However, most of these studies have focused on a specific area, such as fabrication, data analysis, or experimentation. This approach can lead to challenges regarding the reliability, accuracy, or connectivity of the components. Therefore, there is a pressing need to consider the sensor's placement in an overall system and find ways to maximize the efficiency of such flexible sensors. This paper proposes a fabrication method for soft capacitive pressure sensors with spacer fabric, conductive inks, and encapsulation glue. The sensor exhibits a good sensitivity of 0.04 kPa-1, a fast recovery time of 7 milliseconds, and stability of 10,000 cycles. We also evaluate how to connect the sensor to other traditional sensors or hardware components. Some machine learning models are applied to these built-in soft sensors. As expected, the embedded wearables achieve a high accuracy of 96% when recognizing human walking phases.

4.
Biosci Microbiota Food Health ; 42(2): 104-113, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37016686

RESUMO

Fermented soy sauce consists of microorganisms that exert beneficial effects. However, the microbial community dynamics during the fermentation course is poorly characterized. Soy sauce production is classified into the stages of mash fermentation with koji (S0), brine addition (S1), microbial transformation (S2), flavor creation (S3), and fermentation completion (S4). In this study, microbial succession was investigated across stages at different temperatures using metagenomics analyses. During mash fermentation, Aspergillus dominated the fungal microbiota in all stages, while the bacterial composition was dominated by Bacillus at room temperature and by a diverse composition of enriched lactic acid bacteria (LAB) at a controlled temperature. Compared with a stable fungal composition, bacterial dynamics were mostly attributable to fluctuations of LAB, which break down carbohydrates into lactic acid. After adding brine, increased levels of Enterococcus and decreased levels of Lactococcus from S1 to S4 may reflect differences in salinity tolerance. Staphylococcus, as a fermentation starter at S0, stayed predominant throughout fermentation and hydrolyzed soybean proteins. Meanwhile, Rhizopus and Penicillium may improve the flavor. The acidification of soy sauce was likely attributable to production of organic acids by Bacillus and LAB under room temperature and controlled temperature conditions, respectively. Metagenomic analysis revealed that microbial succession was associated with the fermentation efficiency and flavor enhancement. Controlled temperature nurture more LAB than uncontrolled temperatures and may ensure the production of lactic acid for the development of soy sauce flavor.

5.
Micromachines (Basel) ; 13(4)2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35457842

RESUMO

The hybrid wafer bonding technique is drawing much interest in relation to three-dimensional integration technology, and its areas of application are expanding from image sensors to semiconductor memory packages. In hybrid bonding, the bond strength and void formation are the main issues influencing the performance, reliability, and yield of the bonding. In this study, we systematically investigate several parameters that affect both the bond strength and void formation, including the plasma gas, plasma power, and surface roughness. In particular, the effects of the wafer warpage on void formation were investigated. As O2 gas was used during plasma activation, the highest oxide growth rate and strongest bond strength were achieved. The bond strength improved when the oxide thickness was increased. An increase in the low-frequency plasma power improved the bond strength. However, when the plasma power increased further, the surface roughness increased due to the ion bombardment effect during the use of the plasma, resulting in a reduction in the bond strength. Therefore, optimization of the plasma power is required to improve the bond strength. It was found that the wafer warpage was also an important parameter which affected the formation of edge voids. The wafers with residual compressive stress exhibited fewer edge voids than those with tensile stress. Several methods to minimize edge void formation in wafers are proposed. The present study will provide practical guidelines to enhance the quality and yield of the bonding process and devices.

6.
Biomed Res Int ; 2022: 1539063, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35309175

RESUMO

Background: Nurses are one of the population groups with the highest prevalence of musculoskeletal disorders (MSDs). Preventive measures in Vietnamese hospitals on the job have not been proposed to study their effectiveness due to barriers related to the lack of knowledge about MSDs by health care administrators and the lack of human resources with expertise in MSD management in hospitals. Objectives: This study is aimed at evaluating the effectiveness of basic interventions (education, physical exercise) to prevent MSDs among district hospital nurses in Vietnam. Material and Methods. A quasi-experimental study was carried out before/after over a period of one year among two groups of nurses, one receiving the intervention (n = 162) and the other the control group (n = 128). The intervention includes 3 components: training on MSDs, ergonomics training, and instructions for physical exercise. The pre- and postintervention assessment tools included the Modified Nordic, Quality of Life Enjoyment and Satisfaction Short-Form (Q-LES-Q-SF), and the Kessler Psychological Distress Questionnaire (K6). A generalized estimating equation analysis was performed to assess the difference between the two groups at two points in time (before and after the intervention) on some indicators (prevalence of MSDs in the last 12 months and 7 days, score for quality of life and psychological distress). Results: There was a significant difference of the test on the prevalence of MSDs in the last 7 days between the 2 groups before and after the intervention with the p value = 0.016. This difference occurred in 4 anatomical sites: neck, shoulder/upper arm, wrists/hand, and lower back, with p values being 0.013, 0.011, 0.038, and 0.009, respectively. Conclusions: The intervention measures are probably effective in reducing the prevalence of MSDs at 4 anatomical sites in the last 7 days. More in-depth studies are needed with a combination of measures over a longer period of time to obtain stronger evidence of interventions.


Assuntos
Doenças Musculoesqueléticas , Doenças Profissionais , Hospitais de Distrito , Humanos , Doenças Musculoesqueléticas/epidemiologia , Doenças Musculoesqueléticas/prevenção & controle , Doenças Profissionais/epidemiologia , Doenças Profissionais/prevenção & controle , Prevalência , Qualidade de Vida , Fatores de Risco , Inquéritos e Questionários , Vietnã/epidemiologia
7.
Genes (Basel) ; 13(2)2022 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-35205313

RESUMO

(1) Background: Individuals with BRCA1/2 gene mutations are at increased risk of breast and ovarian cancer. The prevalence of BRCA1/2 mutations varies by race and ethnicity, and the prevalence and the risks associated with most BRCA1/2 mutations has not been unknown in the Vietnamese population. We herein screen the entire BRCA1 and BRCA2 genes for breast and ovarian cancer patients with a family history of breast cancer and ovarian cancer, thereby, suggesting a risk score associated with carrier status and history for aiding personalized treatment; (2) Methods: Between December 2017 and December 2019, Vietnamese patients who had a pathological diagnosis of breast and epithelial ovarian cancer were followed up, prospectively, after treatment from two large institutions in Vietnam. Blood samples from 33 Vietnamese patients with hereditary breast and ovarian cancers (HBOC) syndrome were collected and analyzed using Next Generation Sequencing; (3) Results: Eleven types of mutations in both BRCA1 (in nine patients) and BRCA2 (in three patients) were detected, two of which (BRCA1:p.Tyr1666Ter and BRCA2:p.Ser1341Ter) have not been previously documented in the literature. Seven out of 19 patient's relatives had BRCA1/2 gene mutations. All selected patients were counselled about the likelihood of cancer rising and prophylactic screening and procedures. The study established a risk score associated with the cohorts based on carrier status and family history; (4) Conclusions: Our findings suggested the implications for the planning of a screening programme for BRCA1 and BRCA2 genes testing in breast and ovarian cancer patients and genetic screening in their relatives. BRCA1/2 mutation carriers without cancer should have early and regular cancer screening, and prophylactic measures. This study could be beneficial for a diverse group in a large population-specific cohort, related to HBOC Syndrome.


Assuntos
Síndrome Hereditária de Câncer de Mama e Ovário , Neoplasias Ovarianas , Proteína BRCA1/genética , Feminino , Predisposição Genética para Doença , Síndrome Hereditária de Câncer de Mama e Ovário/epidemiologia , Síndrome Hereditária de Câncer de Mama e Ovário/genética , Humanos , Mutação , Neoplasias Ovarianas/epidemiologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Vietnã/epidemiologia
8.
J Colloid Interface Sci ; 612: 121-131, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-34992013

RESUMO

Water splitting via the use of an efficient catalyst is a clean and cost-effective approach to produce green hydrogen. In this study, we successfully developed a novel hybrid coming from thin NiO-NiSe2 nanosheet-based heterostructure shelled high-conductive titanium nitride nanoarrays (TiN@NiO-NiSe2) supported on carbon cloth (CC) via an optimized in-situ synthesis strategy. The hybrid possesses unique physicochemical properties due to the combination of merits from individual components and their synergistic effects, thereby boosting number and type of electroactive sites, reasonably adjusting Gibbs free adsorption energy, and promoting charge/mass transfers. As a potential bifunctional electrocatalyst, the hybrid requires low overpotentials of 115 and 240 mV to reach a current response of 10 mA cm-2 towards hydrogen evolution reaction and oxygen evolution reaction in 1.0 M KOH, respectively. Therefore, an electrolyzer of the TiN@NiO-NiSe2 on CC exhibits a low operation voltage of 1.57 V at 10 mA cm-2 together with a prospective durability, which exceed behaviors of Pt/C//RuO2 as well as recently reported bifunctional electrocatalysts. The results suggest a promising approach for developing cost-effective catalyst towards green hydrogen production via water splitting.

9.
Materials (Basel) ; 14(4)2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33670695

RESUMO

In the injection molding field, the flow of plastic material is one of the most important issues, especially regarding the ability of melted plastic to fill the thin walls of products. To improve the melt flow length, a high mold temperature was applied with pre-heating of the cavity surface. In this paper, we present our research on the injection molding process with pre-heating by external gas-assisted mold temperature control. After this, we observed an improvement in the melt flow length into thin-walled products due to the high mold temperature during the filling step. In addition, to develop the heating efficiency, a flow focusing device (FFD) was applied and verified. The simulations and experiments were carried out within an air temperature of 400 °C and heating time of 20 s to investigate a flow focusing device to assist with external gas-assisted mold temperature control (Ex-GMTC), with the application of various FFD types for the temperature distribution of the insert plate. The heating process was applied for a simple insert model with dimensions of 50 mm × 50 mm × 2 mm, in order to verify the influence of the FFD geometry on the heating result. After that, Ex-GMTC with the assistance of FFD was carried out for a mold-reading process, and the FFD influence was estimated by the mold heating result and the improvement of the melt flow length using acrylonitrile butadiene styrene (ABS). The results show that the air sprue gap (h) significantly affects the temperature of the insert and an air sprue gap of 3 mm gives the best heating rate, with the highest temperature being 321.2 °C. Likewise, the actual results show that the height of the flow focusing device (V) also influences the temperature of the insert plate and that a 5 mm high FFD gives the best results with a maximum temperature of 332.3 °C. Moreover, the heating efficiency when using FFD is always higher than without FFD. After examining the effect of FFD, its application was considered, in order to improve the melt flow length in injection molding, which increased from 38.6 to 170 mm, while the balance of the melt filling was also clearly improved.

10.
J Occup Health ; 62(1): e12161, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32949190

RESUMO

BACKGROUND: Nurses are one of the population groups with the highest prevalence of musculoskeletal disorders (MSDs). At many sites, musculoskeletal symptoms (MS) represent a major health-care burden, adversely affecting nurses' quality of life and giving rise to mental health issues. OBJECTIVES: This study measured the prevalence of multi-body-site (two or more anatomical sites) musculoskeletal symptoms (MMS), and the association between MMS, a number of demographic and work characteristics, psychological distress, and the quality of life among district hospital nurses. MATERIAL AND METHODS: A cross-sectional study was performed with 1179 nurses in Haiphong City using three questionnaires: the Modified Nordic; Quality of Life Enjoyment and Satisfaction Short Form (Q-LES-Q-SF); and the Kessler Psychological Distress Questionnaire (K6). RESULTS: Women have a higher MMS prevalence than men (57.1% in women vs 37.6% in men, P < .001). Having a higher number of anatomical sites of MS appears to be associated with a worse quality of life among nurses. Linear regression analysis found a number of other factors negatively associated with the nurses' quality of life: gender (female), age (50-60 years old vs 19-29 years old), and psychological distress. CONCLUSIONS: This study shows a high prevalence of MMS and the relationship between, on the one hand, MMS, gender, age, as well as psychological distress and, on the other hand, the quality of life among nurses in Vietnam. Further in-depth studies are needed to investigate the causal relationships between these indicators.


Assuntos
Doenças Musculoesqueléticas/fisiopatologia , Doenças Musculoesqueléticas/psicologia , Recursos Humanos de Enfermagem Hospitalar/psicologia , Doenças Profissionais/fisiopatologia , Doenças Profissionais/psicologia , Qualidade de Vida , Adulto , Estudos Transversais , Feminino , Hospitais de Distrito , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Musculoesqueléticas/epidemiologia , Doenças Profissionais/epidemiologia , Prevalência , Inquéritos e Questionários , Vietnã/epidemiologia , Adulto Jovem
11.
J Glob Antimicrob Resist ; 22: 620-624, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32590188

RESUMO

BACKGROUND: The increasing rates of clarithromycin (CLR)- and levofloxacin (LVX)-resistant Helicobacter pylori are the main causes of the considerable decrease in the eradication rates of triple therapy and LVX-based regimens. The aims of this study were to determine the rates of CLR- and LVX-resistant H. pylori by the Epsilometer test and to assess the risk factors for this antibiotic resistance among patients with chronic gastritis in the south east area of Vietnam. METHODS: Gastric biopsy specimens were obtained from 153 patients with H. pylori-positive chronic gastritis for use in culture and in the Epsilometer test to determine CLR and LVX susceptibilities. RESULTS: The rates of H. pylori resistance to CLR and LVX were 72.6% and 40.5%, respectively. Dual-resistant H. pylori (to both CLR and LVX) accounted for 30.7% of patients. The rates of high-level resistance to CLR and LVX were 18.9% and 83.9%, respectively. Multivariate analysis showed that age older than 30 years (odds ratio [OR] = 3.80, 95% confidence interval [CI] 1.61-8.97) and history of H. pylori treatment (OR = 8.72, 95% CI 1.90-39.91) were independent risk factors for CLR resistance, whereas only age older than 35 years (OR = 2.42, 95% CI 1.23-4.76) was an independent risk factor for LVX resistance. CONCLUSIONS: These results revealed high rates of resistance of H. pylori to CLR and LVX in patients with chronic gastritis in the south east area of Vietnam. This suggests that CLR-based triple therapy should not be used for the eradication treatment of H. pylori, and LVX susceptibility testing of H. pylori strains should be performed before choosing alternative regimens.


Assuntos
Gastrite , Infecções por Helicobacter , Helicobacter pylori , Adulto , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Claritromicina/farmacologia , Claritromicina/uso terapêutico , Farmacorresistência Bacteriana , Gastrite/tratamento farmacológico , Gastrite/epidemiologia , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/genética , Humanos , Levofloxacino/farmacologia , Levofloxacino/uso terapêutico , Vietnã/epidemiologia
12.
Biomed Res Int ; 2020: 3254605, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32596296

RESUMO

BACKGROUND: Musculoskeletal disorders (MSDs) are commonly observed among workers around the world. These diseases not only affect the health of workers, their quality of life, and their performance, but the effects of such diseases also represent a great burden for the health and social systems. These issues are even more prevalent in developing countries, and nurses are no exception. Many studies worldwide have shown a high prevalence of work-related MSDs in each body position among nurses. However, there are very few studies that have mentioned multisite musculoskeletal symptoms (MMS). OBJECTIVES: To describe the prevalence and characteristics of MMS among district hospital nurses in Haiphong, Vietnam. Material and Methods. A cross-sectional study was carried out on 1179 nurses working in all 15 district hospitals using the Modified Nordic Questionnaire at 9 anatomical sites on the body (neck, shoulder/upper arm, elbow/forearm, wrist/hand, upper back, lower back, hip/thigh, knee/lower leg, and ankle/foot). The following main indicators were calculated: the prevalence of musculoskeletal symptoms (MS) (at least 1 of 9 sites), MMS (two or more sites), and widespread musculoskeletal symptoms (WMS) (MS of the upper limb, the lower limb, and the back or the neck). RESULTS: The prevalence of MS during the past 12 months and symptoms lasting for at least 30 days was 60.6% and 17.2% in men and 77.6% and 21.5% in women, respectively. The lower back, neck, upper back, and shoulder/upper arm were the most common sites affected. In terms of MMS, the prevalence was 37.6% in men and 57.1% in women during the past 12 months while 8.6% of men and 11.3% of women reported that symptoms lasted for at least 30 days. The prevalence of MMS tended to increase with age, seniority, having a history of musculoskeletal diseases, and in nurses working in district hospitals located in urban areas. Nearly 90% of MMS concerned two or three anatomical regions during the past 12 months, and almost 80% of MMS lasting at least 30 days involved two or three anatomical regions. The prevalence of WMS was 10.4% in men and 18.6% in women during the past 12 months and 0.9% in men and 2.1% in women lasting at least 30 days. CONCLUSIONS: This study showed the high prevalence of MMS and WMS among nursing staff. Further and more extensive research is needed to improve our understanding of multisite musculoskeletal symptoms and act as the foundation for developing preventive measures for nurses.


Assuntos
Doenças Musculoesqueléticas/epidemiologia , Enfermeiras e Enfermeiros/estatística & dados numéricos , Doenças Profissionais/epidemiologia , Adulto , Estudos Transversais , Feminino , Hospitais de Distrito , Humanos , Masculino , Dor/epidemiologia , Prevalência , Vietnã , Adulto Jovem
13.
Nanotechnology ; 31(34): 345401, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32365336

RESUMO

In this work, a feasible one-pot approach to synthesize manganese oxide/graphene composites, the so-called plasma-enhanced electrochemical exfoliation process (PE3P), has been developed. Herein, a composite of graphene decorated with manganese oxide nanoparticles was prepared via PE3P from a KMnO4 solution and graphite electrode under a voltage of 70 V in an ambient environment. By controlling the initial KMnO4 concentration, we obtained distinct MnO2/graphene samples. The prepared samples were characterized by scanning electron microscopy, transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and Raman spectroscopy. The electrochemical measurements of the MnO2/graphene composites revealed that the specific capacitance of the samples is approximately 320 F g-1 at a scan rate of 10 mV s-1, which is comparably very high for manganese oxide/carbon-based supercapacitor electrode materials. Considering the simple, low-cost, one-step and environmentally friendly preparation, our approach has the potential to be used for the fabrication of MnO2/graphene composites as the electrode materials of supercapacitors.

14.
BMC Public Health ; 20(1): 316, 2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-32164624

RESUMO

BACKGROUND: Organisational culture (OC) has increasingly become a crucial factor in defining healthcare practice and management. However, there has been little research validating and adapting OCAI (organisational culture assessment instrument) to assess OC in healthcare settings in developing countries, including Vietnam. The purpose of this study is to validate the OCAI in a hospital setting using key psychometric tests and confirmatory factor analysis (CFA). METHODS: This is a cross-sectional study. Self-administered structured questionnaire was completed by 566 health professionals from a Vietnamese national general hospital, the General Hospital of Quang Nam province. The psychometric tests and CFA were utilized to detect internal reliability and construct validity of the instrument. RESULTS: The Cronbach's alpha coefficients (α-reliability statistic) ranged from 0.6 to 0.8. In current culture, the coefficient was 0.80 for clan and 0.60 for adhocracy, hierarchy and market dimension, while in expected culture, the coefficient for clan, adhocracy, hierarchy, and market dimension was 0.70, 0.70, 0.70 and 0.60, respectively. The CFA indicated that most factor loading coefficients were of moderate values ranging from 0.30 to 0.60 in both current and expected culture model. These models are of marginal good fit. CONCLUSIONS: The study findings suggest that the OCAI be of fairly good reliability and construct validity in measuring four types of organisational culture in healthcare setting in resource-constrained countries such as Vietnam. This result is a first step towards developing a valid Vietnamese version of the OCAI which can also provide a strong case for future research in the field of measuring and managing organisational culture.


Assuntos
Atenção à Saúde/organização & administração , Cultura Organizacional , Inquéritos e Questionários , Adulto , Estudos Transversais , Análise Fatorial , Feminino , Hospitais Gerais , Humanos , Masculino , Recursos Humanos em Hospital/psicologia , Recursos Humanos em Hospital/estatística & dados numéricos , Psicometria , Reprodutibilidade dos Testes , Vietnã
15.
J Environ Manage ; 241: 535-548, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30318157

RESUMO

Calcium carbonate (CaCO3)-enriched biomaterial derived from freshwater mussel shells (FMS) was used as a non-porous biosorbent to explore the characteristics and mechanisms of cadmium adsorption in aqueous solution. The adsorption mechanism was proposed by comparing the FMS properties before and after adsorption alongside various adsorption studies. The FMS biosorbent was characterized using nitrogen adsorption/desorption isotherm, X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, Fourier-transform infrared spectroscopy, and point of zero charge. The results of batch experiments indicated that FMS possessed an excellent affinity to Cd(II) ions within solutions pH higher than 4.0. An increase in ionic strength resulted in a significant decrease in the amount of Cd(II) adsorbed onto FMS. Kinetic study demonstrated that the adsorption process quickly reached equilibrium at approximately 60 min. The FMS biosorbent exhibited the Langmuir maximum adsorption capacity as follows: 18.2 mg/g at 10 °C < 26.0 mg/g at 30 °C < 28.6 mg/g at 50 °C. The Cd(II) adsorption process was irreversible, spontaneous (-ΔG°), endothermic (+ΔH°), and more random (+ΔS°). Selective order (mmol/g) of metal cations followed as Pb2+ > Cd2+ > Cu2+ > Cr3+ > Zn2+. For column experiments, the highest Thomas adsorption capacity (7.86 mg/g) was achieved at a flow rate (9 mL/min), initial Cd(II) concentration (10 mg/L), and bed height (5 cm). The Cd(II) removal by FMS was regarded as non-activated chemisorption that occurred very rapidly (even at a low temperature) with a low magnitude of activation energy. Primary adsorption mechanism was surface precipitation. Cadmium precipitated in the primary (Cd,Ca)CO3 form with a calcite-type structure on the FMS surface. A crust of rhombohedral crystals on the substrate was observed by SEM. Freshwater mussel shells have the potential as a renewable adsorbent to remove cadmium from water.


Assuntos
Cádmio , Poluentes Químicos da Água , Adsorção , Carbonato de Cálcio , Concentração de Íons de Hidrogênio , Cinética
16.
Bull Environ Contam Toxicol ; 102(2): 287-296, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30547219

RESUMO

Concentrations of PCDD/Fs, dioxin-like PCBs (dl-PCBs), PeCB and HCB were determined in flue gas, fly ash and bottom ash samples collected from brick production, steel production, and zinc production plants, an industrial waste incinerator and a medical waste incinerator in northern Vietnam to understand the contamination levels, accumulation patterns and extent of emission. Total TEQs concentrations of PCDD/Fs and dl-PCBs in flue gas and ash samples from these industrial plants ranged from 0.304 to 50.55 pg/Nm3 and 1.43 to 440 pg/g, respectively. PeCB and HCB residues in flue gas samples ranged from 0.839 to 46.59 ng/Nm3 and 1.16 to 60.5 ng/Nm3, respectively. The emission factors of 4.8-740 ngTEQs/tonne for PCDD/Fs and dl-PCBs, 67.12-240.7 µg/ton for PeCB and 11.64-889.3 µg/ton for HCB were obtained in flue gas samples. This is among the first reports on the emission factor of PCDD/Fs, dl-PCBs, PeCB, HCB in brick production, zinc production and waste incineration in Vietnam.


Assuntos
Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Resíduos Industriais/análise , Cinza de Carvão/química , Gases/química , Aço , Vietnã
17.
Artigo em Inglês | MEDLINE | ID: mdl-33581010

RESUMO

The present study investigated the phytochemicals and antidiabetic effect of the aqueous extract of the fruit of Punica granatum Linn. in streptozotocin (STZ)-induced diabetic mice. The fruit of P. granatum was extracted with water. The phytochemicals of the water extract were investigated by the liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The water extract of P. granatum at doses of 150 and 300 mg/kg body weight (bw) was administered to mice for 21 days, and blood glucose level, triglyceride, total cholesterol, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein-cholesterol, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzyme were estimated. Analyzed phytochemicals showed the fruit of P. granatum Linn has a high amount of phenolic and flavonoid compounds, which provide beneficial effect for this plant. The oral administration of the fruit extract of P. granatum at doses of 150 and 300 mg/kg bw for 21 days significantly reduced blood glucose level, triglycerides, serum cholesterol, LDL-cholesterol, AST and ALT enzyme. Our results suggested that the fruit extract of P. granatum has strong antidiabetic effect in STZ-induced diabetic mice. The fruit of this plant might be a potential source of drug for treatment of diabetes.

18.
Nanotechnology ; 29(48): 485201, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30192742

RESUMO

Graphene and h-BN are grown by chemical vapor deposition in ultra high vacuum conditions on the Pt(110) surface. Scanning tunneling microscopy measurements and low-energy electron diffraction data indicate that graphene forms a variety of differently oriented incommensurate domains although with a strong preference to align its [Formula: see text] direction with the [Formula: see text] direction of Pt. Meanwhile, h-BN exhibits a c(8 × 10) commensurate superstructure, which presents a high level of defectivity that implies local variation of the periodicity (i.e. mixed c(8 × 10) and c(8 × 12) patches) and the introduction of local defects. The combination of advanced photoemission spectroscopy data (angle-resolved photoemission spectroscopy from the valence band) and ab initio calculations indicates that both 2D materials interact weakly with the substrate: graphene exhibits neutral doping and is morphologically flat, even if it nucleates on the relatively highly corrugated rectangular (110) surface. In the case of h-BN, the interaction is slightly stronger and is characterized by a small electron transfer from surface Pt atoms to nitrogen atoms. The (110) termination of Pt is therefore a quite interesting surface for the growth of 2D materials because given its low symmetry, it may favor the growth of selectively oriented domains but does not affect their pristine electronic properties.

19.
J Basic Clin Physiol Pharmacol ; 28(5): 413-423, 2017 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-28708573

RESUMO

Alzheimer's disease (AD) is related to increasing age. It is mainly characterized by progressive neurodegenerative disease, which damages memory and cognitive function. Natural products offer many options to reduce the progress and symptoms of many kinds of diseases, including AD. Meanwhile, natural compound structures, including lignans, flavonoids, tannins, polyphenols, triterpenes, sterols, and alkaloids, have anti-inflammatory, antioxidant, anti-amyloidogenic, and anticholinesterase activities. In this review, we summarize the pathogenesis and targets for treatment of AD. We also present several medicinal plants and isolated compounds that are used for preventing and reducing symptoms of AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Humanos , Plantas Medicinais/química
20.
J Basic Clin Physiol Pharmacol ; 28(1): 79-84, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27861139

RESUMO

BACKGROUND: Sanchezia speciosa has been used in traditional medicine for gastritis treatment in Vietnam. Some phytochemical study showed that S. speciosa contains high amounts of flavonoids and cardiac glycoside compounds. In the present study, we isolated four compounds from the ethanol extract of the S. speciosa leaf, and we evaluated the in vitro antioxidant and anti-inflammatory effect of the isolated compound from the ethanol extract of the S. speciosa leaf. METHODS: The leaf of S. speciosa Leonard was extracted with ethanol 96%. Compounds were isolated using column chromatography and identified by spectroscopic method, including IR, MS, and NMR and by comparing their physicochemical and spectral data with those published in literatures. These isolated compounds were investigated for their antioxidant activity using DPPH and inflammation inhibitory activity by inhibition of albumin denaturation assay. RESULTS: We have isolated four compounds quercetin 3-O-α-l-rhamnopyranosid (quercitrin) (1), quercetin 3-O-ß-d-galactopyranosid (hyperosid) (2), sitosterol-3-O-ß-D-glucopyranosid (daucosterol) (3), and 3-methyl-1H-benz[f]indole-4,9-dione (4) from the ethanolic extract of the S. speciosa leaf. The antioxidant activities were in the following order: compound 2>compound 1>compound 4>compound 3. The IC50 values of scavenging DPPH radicals for compound 2 was 20.83±1.29 µg/mL. For anti-inflammatory activities, the order was compound 4>compound 3>compound 2>compound 1. Compound 4 showed the strongest inhibition, with IC50 values of 193.70±5.24 µg/mL. CONCLUSIONS: These compounds 1, 2, and 4 were isolated for the first time from the leaves of S. speciosa. These compounds showed strong antioxidant and anti-inflammatory activity.


Assuntos
Acanthaceae , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta , Anti-Inflamatórios/isolamento & purificação , Antioxidantes/isolamento & purificação , Relação Dose-Resposta a Droga , Etanol/farmacologia , Sequestradores de Radicais Livres/isolamento & purificação , Sequestradores de Radicais Livres/farmacologia , Humanos , Extratos Vegetais/isolamento & purificação , Albumina Sérica/antagonistas & inibidores , Albumina Sérica/metabolismo
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