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1.
Small ; 20(27): e2309122, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38377285

RESUMEN

This research designs a triphasic Ni2P-Ni12P5-Ru heterostructure with amorphous interface engineering strongly coupled by a cobalt nano-surface (Co@NimPn-Ru) to form a hierarchical 3D interconnected architecture. The Co@NimPn-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@NimPn-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 Ni2P, Ni12P5, 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.
Small ; : e2405952, 2024 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-39377360

RESUMEN

Enhancement of an alkaline water splitting reaction in Pt-based single-atom catalysts (SACs) relies on effective metal-support interactions. A Pt single atom (PtSA)-immobilized three-phased PtSA@VP-Ni3P-MoP heterostructure on nickel foam is presented, demonstrating high catalytic performance. The existence of PtSA on triphasic metal phosphides gives an outstanding performance toward overall water splitting. The PtSA@VP-Ni3P-MoP performs a low overpotential of 28 and 261 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at a current density of 10 and 25 mA cm-2, respectively. The PtSA@VP-Ni3P-MoP (+,-) alkaline electrolyzer achieves a minimum cell voltage of 1.48 V at a current density of 10 mA cm-2 for overall water splitting. Additionally, the electrocatalyst exhibits a substantial Faradaic yield of ≈98.12% for H2 and 98.47% for O2 at a current density of 50 mA cm-2. Consequently, this study establishes a connection for understanding the active role of single metal atoms in substrate configuration for catalytic performance. It also facilitates the successful synthesis of SACs, with a substantial loading on transition metal phosphides and maximal atomic utilization, providing more active sites and, thereby enhancing electrocatalytic activity.

3.
Nanotechnology ; 31(34): 345401, 2020 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-32365336

RESUMEN

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.

4.
BMC Public Health ; 20(1): 316, 2020 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-32164624

RESUMEN

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.


Asunto(s)
Atención a la Salud/organización & administración , Cultura Organizacional , Encuestas y Cuestionarios , Adulto , Estudios Transversales , Análisis Factorial , Femenino , Hospitales Generales , Humanos , Masculino , Personal de Hospital/psicología , Personal de Hospital/estadística & datos numéricos , Psicometría , Reproducibilidad de los Resultados , Vietnam
5.
J Environ Manage ; 241: 535-548, 2019 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-30318157

RESUMEN

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.


Asunto(s)
Cadmio , Contaminantes Químicos del Agua , Adsorción , Carbonato de Calcio , Concentración de Iones de Hidrógeno , Cinética
6.
Bull Environ Contam Toxicol ; 102(2): 287-296, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30547219

RESUMEN

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.


Asunto(s)
Monitoreo del Ambiente/métodos , Contaminantes Ambientales/análisis , Residuos Industriales/análisis , Ceniza del Carbón/química , Gases/química , Acero , Vietnam
7.
Nanotechnology ; 29(48): 485201, 2018 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-30192742

RESUMEN

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.

8.
Chemistry ; 21(15): 5826-35, 2015 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-25711882

RESUMEN

Dibromotetracene molecules are deposited on the Cu(110) surface at room temperature. The complex evolution of this system has been monitored at different temperatures (i.e., 298, 523, 673, and 723 K) by means of a variety of complementary techniques that range from STM and temperature-programmed desorption (TPD) to high-resolution X-ray spectroscopy (XPS) and near-edge X-ray absorption fine structure spectroscopy (NEXAFS). State-of-the-art density-functional calculations were used to determine the chemical processes that take place on the surface. After deposition at room temperature, the organic molecules are transformed into organometallic monomers through debromination and carbon-radical binding to copper adatoms. Organometallic dimers, trimers, or small oligomers, which present copper-bridged molecules, are formed by increasing the temperature. Surprisingly, further heating to 673 K causes the formation of elongated chains along the Cu(110) close-packed rows as a consequence of radical-site migration to the thermodynamically more stable molecule heads. Finally, massive dehydrogenation occurs at the highest temperature followed by ring condensation to nanographenic patches. This study is a paradigmatic example of how intermolecular coupling can be modulated by the stepwise control of a simple parameter, such as temperature, through a sequence of domino reactions.

9.
ACS Nano ; 18(25): 16222-16235, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38865209

RESUMEN

High-performance production of green hydrogen gas is necessary to develop renewable energy generation technology and to safeguard the living environment. This study reports a controllable engineering approach to tailor the structure of nickel-layered double hydroxides via doped and absorbed platinum single atoms (PtSA) promoted by low electronegative transition metal (Mn, Fe) moieties (PtSA-Mn,Fe-Ni LDHs). We explore that the electron donation from neighboring transition metal moieties results in the well-adjusted d-band center with the low valence states of PtSA(doped) and PtSA(ads.), thus optimizing adsorption energy to effectively accelerate the H2 release. Meanwhile, a tailored local chemical environment on transition metal centers with unique charge redistribution and high valence states functions as the main center for H2O catalytic dissociation into oxygen. Therefore, the PtSA-Mn,Fe-Ni LDH material possesses a small overpotential of 42 and 288 mV to reach 10 mA·cm-2 for hydrogen and oxygen evolution, respectively, superior to most reported LDH-based catalysts. Additionally, the mass activity of PtSA-Mn,Fe-Ni LDHs proves to be 15.45 times higher than that of commercial Pt-C. The anion exchange membrane electrolyzer stack of PtSA-Mn,Fe-Ni LDHs(+,-) delivers a cell voltage of 1.79 V at 0.5 A·cm-2 and excellent durability over 600 h. This study presents a promising electrocatalyst for a practical water splitting process.

10.
Micromachines (Basel) ; 14(9)2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37763889

RESUMEN

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.

11.
Micromachines (Basel) ; 14(7)2023 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-37512722

RESUMEN

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.

12.
Biosci Microbiota Food Health ; 42(2): 104-113, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37016686

RESUMEN

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.

13.
Opt Lett ; 37(18): 3777-9, 2012 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-23041856

RESUMEN

A parabolic, multilayer x-ray mirror, which can be used with a general lab-based x-ray source, was designed and fabricated. A glass substrate for the mirror was fabricated. Its surface was determined by following the rotation of a parabolic curve and was polished precisely. On the substrate surface, six W/Al bilayers were deposited to form the multilayer mirror. The effects of the mirror on x-ray images were investigated based on the calculated modulation transfer function (MTF) and image intensity values. Higher MTF and intensity values of an x-ray image were obtained using the mirror.

14.
Nanotechnology ; 23(9): 095702, 2012 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-22322440

RESUMEN

III-V antimonide nanowires are among the most interesting semiconductors for transport physics, nanoelectronics and long-wavelength optoelectronic devices due to their optimal material properties. In order to investigate their complex crystal structure evolution, faceting and composition, we report a combined scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning tunneling microscopy (STM) study of gold-nucleated ternary InAs/InAs(1-x)Sb(x) nanowire heterostructures grown by molecular beam epitaxy. SEM showed the general morphology and faceting, TEM revealed the internal crystal structure and ternary compositions, while STM was successfully applied to characterize the oxide-free nanowire sidewalls, in terms of nanofaceting morphology, atomic structure and surface composition. The complementary use of these techniques allows for correlation of the morphological and structural properties of the nanowires with the amount of Sb incorporated during growth. The addition of even a minute amount of Sb to InAs changes the crystal structure from perfect wurtzite to perfect zinc blende, via intermediate stacking fault and pseudo-periodic twinning regimes. Moreover, the addition of Sb during the axial growth of InAs/InAs(1-x)Sb(x) heterostructure nanowires causes a significant conformal lateral overgrowth on both segments, leading to the spontaneous formation of a core-shell structure, with an Sb-rich shell.


Asunto(s)
Antimonio/química , Cristalización/métodos , Microscopía Electrónica/métodos , Nanotubos/química , Nanotubos/ultraestructura , Sustancias Macromoleculares/química , Ensayo de Materiales/métodos , Conformación Molecular , Tamaño de la Partícula , Transición de Fase , Propiedades de Superficie
15.
Biomed Eng Online ; 11: 55, 2012 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-22913755

RESUMEN

BACKGROUND: This study investigated the relationship between dental occlusion and arm strength; in particular, the imbalance in the jaw can cause loss in arm strength phenomenon. One of the goals of this study was to record the maximum forces that the subjects can resist against the pull-down force on their hands while biting a spacer of adjustable height on the right or left side of the jaw. Then EMG measurement was used to determine the EMG-Force relationship of the jaw, neck and arms muscles. This gave us useful insights on the arms strength loss due to the biomechanical effects of the imbalance in the jaw mechanism. METHODS: In this study to determine the effects of the imbalance in the jaw to the strength of the arms, we conducted experiments with a pool of 20 healthy subjects of both genders. The subjects were asked to resist a pull down force applied on the contralateral arm while biting on a firm spacer using one side of the jaw. Four different muscles - masseter muscles, deltoid muscles, bicep muscles and trapezoid muscles - were involved. Integrated EMG (iEMG) and Higuchi fractal dimension (HFD) were used to analyze the EMG signals. RESULTS: The results showed that (1) Imbalance in the jaw causes loss of arm strength contra-laterally; (2) The loss is approximately a linear function of the height of the spacers. Moreover, the iEMG showed the intensity of muscle activities decreased when the degrees of jaw imbalance increased (spacer thickness increased). In addition, the tendency of Higuchi fractal dimension decreased for all muscles. CONCLUSIONS: This finding indicates that muscle fatigue and the decrease in muscle contraction level leads to the loss of arm strength.


Asunto(s)
Brazo/fisiopatología , Electromiografía/métodos , Maxilares/fisiopatología , Fuerza Muscular , Procesamiento de Señales Asistido por Computador , Fenómenos Biomecánicos , Femenino , Fractales , Humanos , Maxilares/anatomía & histología , Masculino , Adulto Joven
16.
Micromachines (Basel) ; 13(4)2022 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-35457842

RESUMEN

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.

17.
Biomed Res Int ; 2022: 1539063, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35309175

RESUMEN

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.


Asunto(s)
Enfermedades Musculoesqueléticas , Enfermedades Profesionales , Hospitales de Distrito , Humanos , Enfermedades Musculoesqueléticas/epidemiología , Enfermedades Musculoesqueléticas/prevención & control , Enfermedades Profesionales/epidemiología , Enfermedades Profesionales/prevención & control , Prevalencia , Calidad de Vida , Factores de Riesgo , Encuestas y Cuestionarios , Vietnam/epidemiología
18.
J Colloid Interface Sci ; 612: 121-131, 2022 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-34992013

RESUMEN

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.

19.
Genes (Basel) ; 13(2)2022 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-35205313

RESUMEN

(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.


Asunto(s)
Síndrome de Cáncer de Mama y Ovario Hereditario , Neoplasias Ováricas , Proteína BRCA1/genética , Femenino , Predisposición Genética a la Enfermedad , Síndrome de Cáncer de Mama y Ovario Hereditario/epidemiología , Síndrome de Cáncer de Mama y Ovario Hereditario/genética , Humanos , Mutación , Neoplasias Ováricas/epidemiología , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Vietnam/epidemiología
20.
Materials (Basel) ; 14(4)2021 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-33670695

RESUMEN

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.

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