RESUMEN

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.

Asunto(s)

Agar , Grafito , Azul de Metileno , Contaminantes Químicos del Agua , Adsorción , Grafito/química , Porosidad , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación , Azul de Metileno/química , Agar/química , Purificación del Agua/métodos , Triazinas/química , Restauración y Remediación Ambiental/métodos , Carbono/química , Aguas Residuales/química , Concentración de Iones de Hidrógeno , Compuestos de Nitrógeno/química , Cinética , Tiourea/química

RESUMEN

The concept of three-dimensional stacking of device layers has attracted significant attention with the increasing difficulty in scaling down devices. Monolithic 3D (M3D) integration provides a notable benefit in achieving a higher connection density between upper and lower device layers than through-via-silicon. Nevertheless, the practical implementation of M3D integration into commercial production faces several technological challenges. Developing an upper active channel layer for device fabrication is the primary challenge in M3D integration. The difficulty arises from the thermal budget limitation for the upper channel process because a high thermal budget process may degrade the device layers below. This paper provides an overview of the potential technologies for forming active channel layers in the upper device layers of M3D integration, particularly for complementary metal-oxide-semiconductor devices and digital circuits. Techniques are for polysilicon, single crystal silicon, and alternative channels, which can solve the temperature issue for the top layer process.

RESUMEN

In this study, silver-immobilized graphene oxide/chitosan (AGC/CTS) membranes were assembled by the solvent evaporation method, wherein Curcuma longa extract was used to synthesize silver-immobilized graphene oxide (AGC) nanocomposite. The characterization results showed that the AGC was successfully synthesized with AgNPs distributed quite evenly on GO sheets. The as-prepared AGC also exhibited high antibacterial activity and low cytotoxicity towards normal cell lines compared to human epithelial carcinoma cell lines. Besides, the fabrication of AGC/CTS membranes was additionally assessed with different AGC ratios and thicknesses. The results revealed the membrane containing 3 wt% of AGC with great hygroscopicity and elastic modulus of 27.03 ± 3.07 MPa. The samples also performed excellent bactericidal capability, along with good mechanical properties for banana preservation. Therewithal, the membrane-coated bananas were also elucidated to ripen at slower paces and less damage, with no appearance of patches of mold on the banana peel surface, eventually prolonging the shelf life of bananas up to 10 days as compared to the non-coated ones. The aforesaid results confirm the potential application of the AGC/CTS membrane as a safe and alternative fruit preservation agent in the food industry.

Asunto(s)

Quitosano , Grafito , Nanopartículas del Metal , Musa , Nanocompuestos , Humanos , Plata/química , Grafito/química , Nanocompuestos/química , Nanopartículas del Metal/química , Antibacterianos/farmacología , Antibacterianos/química

RESUMEN

BACKGROUND: University students are vulnerable to changes due to COVID-19 pandemic. Although warning has been made about the impact of this crisis on students' mental health, there are barely any sufficient study. This work investigated how the pandemic affected the mental health of students at the Vietnam National University of Ho Chi Minh City (VNU-HCMC) and efficiency of available mental health supportive methods. METHODS: An online survey was conducted among students at Vietnam National University of Ho Chi Minh City (VNU-HCMC) from October 18, 2021, to October 25, 2021. Microsoft Excel 16.51 (Microsoft, USA) and R language, Epi packages 2.44 and 4.1.1 (rdrr.io) were used for data analysis. RESULTS: Thirty-seven thousand one hundred fifty students participated in the survey, including 48.4% female and 51.6% male. Online learning pressure was mainly recorded (65.1%). Many students suffered from sleeping disorders (56.2%). Some reported being victims of abuse (5.9%). Female students expressed a significantly higher level of distress than males, particularly the feeling of ambiguity about the purpose of life (p-value < 0.0001, OR: 0.94, 95% CI: [0.95-0.98]). Third-year students suffered higher stress levels than others, especially in online learning (68.8%, p-value < 0.05). Mental health statuses among students of different lockdown status regions were not significantly different. Therefore, lockdown status did not affect the stress levels of students which suggested that poor mental health outcomes seemed to root in the suspension of everyday university life rather than the prohibition of going out. CONCLUSIONS: During COVID-19, students experienced lots of stress and mental problems. These findings underscore the importance of academic and innovative activities, bringing attention to the needs of interactive study and extra-curricular activities.

Asunto(s)

COVID-19 , Salud Mental , Estudiantes , Femenino , Humanos , Masculino , Control de Enfermedades Transmisibles , COVID-19/epidemiología , Estudios Transversales , Pandemias , Pueblos del Sudeste Asiático , Vietnam/epidemiología , Estudiantes/psicología

RESUMEN

INTRODUCTION: The goal of this study was to compare the results of LPD with those of open pancreaticoduodenectomy (OPD). METHOD: Data were retrospectively collected from a database of patients who underwent PD from January 2010 to May 2020. Intraoperative, postoperative, and follow-up assessment studies were conducted. RESULTS: A total of 149 patients were selected. Compared with OPD, LPD was fewer intraoperative blood transfusions (p = 0.015), a longer median operative time (p < 0.001), hospital stay (p = 0.034), a higher rate of bile leakage (p = 0.02), overall morbidity (p = 0.045), and re-operation (p = 0.044). There was no difference between the two groups in severe pancreatic fistula, postoperative bleeding, delayed gastric emptying, Clavien-Dindo classification ≥ III, or 30-day mortality. LPD had a similar number of excised lymph nodes, R0 resection rate, and long-term survival cases involving malignant tumors, ampulla of Vater cancer, and pancreatic ductal adenocarcinoma. CONCLUSION: In the early period, the benefit of LPD has not been found as there was a high rate of conversion to laparotomy, morbidity, and re-operation. Despite that, LPD is a feasible oncological approach with long-term survival comparable to OPD.

Asunto(s)

Laparoscopía , Neoplasias Pancreáticas , Humanos , Pancreaticoduodenectomía/métodos , Estudios Retrospectivos , Vietnam , Neoplasias Pancreáticas/cirugía , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/cirugía , Laparoscopía/métodos , Tiempo de Internación

RESUMEN

The effects of the grain size of Pt bottom electrodes on the ferroelectricity of hafnium zirconium oxide (HZO) were studied in terms of the orthorhombic phase transformation. HZO thin films were deposited by chemical solution deposition on the Pt bottom electrodes with various grain sizes which had been deposited by direct current sputtering. All the samples were crystallized by rapid thermal annealing at 700 °C to allow a phase transformation. The crystallographic phases were determined by grazing incidence X-ray diffraction, which showed that the bottom electrode with smaller Pt grains resulted in a larger orthorhombic phase composition in the HZO film. As a result, capacitors with smaller Pt grains for the bottom electrode showed greater ferroelectric polarization. The smaller grains produced larger in-plane stress which led to more orthorhombic phase transformation and higher ferroelectric polarization.

RESUMEN

This paper presents a straightforward, low-cost, and effective integration process for the fabrication of membrane gate thin film transistors (TFTs) with an air gap. The membrane gate TFT with an air gap can be used as the highly sensitive tactile force sensor. The suspended membrane gate with an air gap as the insulator layer is formed by multiple photolithography steps and photoresist sacrificial layers. The viscosity of the photoresist and the spin speed was used to modify the thickness of the air gap during the coating process. The tactile force was measured by monitoring the drain current of the TFT as the force changed the thickness of the air gap. The sensitivity of the devices was enhanced by an optimal gate size and low Young's modulus of the gate material. This simple process has the potential for the production of small, versatile, and highly sensitive sensors.

RESUMEN

Nickel silicide (NiSi) is commonly used as a contact material for metal junctions but the poor thermal instability of NiSi above 600 °C has limited the further scaling down of devices and the implementation of novel schemes, such as monolithic 3-dimensional integration. This paper suggests a process to improve the thermal stability of NiSi through nitrogen incorporation during the silicidation process. The optimal level of nitrogen incorporation in NiSi reduced the nickel diffusion rate and enhanced the thermal stability by preventing the formation of a nickel disilicide phase. On the other hand, a higher level of N incorporation led to Ni3N formation, which impeded the complete transformation to NiSi. Therefore, it is essential to incorporate the optimal content of N. In this study, NiSi with 3.9% N incorporation showed superior electrical characteristics, such as the sheet resistance, junction leakage, and stable Schottky barrier height, even after high-temperature post silicidation annealing at 600 °C for 30 min.

RESUMEN

Strain DCY85(T) and DCY85-1(T), isolated from rhizosphere of ginseng, were rod-shaped, Gram-reaction-negative, strictly aerobic, catalase positive and oxidase negative. 16S rRNA gene sequence analysis revealed that strain DCY85(T) as well as DCY85-1(T) belonged to the genus Burkholderia and were closely related to Burkholderia fungorum KACC 12023(T) (98.1 and 98.0 % similarity, respectively). The major polar lipids of strain DCY85(T) and DCY85-1(T) were phosphatidylethanolamine, one unidentified aminolipid and two unidentified phospholipids. The major fatty acids of both strains are C16:0, C18:1 ω7c and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c). The predominant isoprenoid quinone of each strain DCY85(T) and DCY85-1(T) was ubiquinone (Q-8) and the G+C content of their genomic DNA was 66.0 and 59.4 mol%, respectively, which fulfill the characteristic range of the genus Burkholderia. The polyamine content of both DCY85(T) and DCY85-1(T) was putrescine. Although both DCY85(T) and DCY85-1(T) have highly similar 16S rRNA and identical RecA and gyrB sequences, they show differences in phenotypic and chemotaxonomic characteristics. DNA-DNA hybridization results proved the consideration of both strains as two different species. Based on the results from our polyphasic characterization, strain DCY85(T) and DCY85-1(T) are considered novel Burkholderia species for which the name Burkholderia ginsengiterrae sp. nov and Burkholderia panaciterrae sp. nov are, respectively, proposed. An emended description of those strains is also proposed. DCY85(T) and DCY85-1(T) showed antagonistic activity against the common root rot pathogen of ginseng, Cylindrocarpon destructans. The proposed type strains are DCY85(T) (KCTC 42054(T) = JCM 19888(T)) and DCY85-1(T) (KCTC 42055(T) = JCM 19889(T)).

Asunto(s)

Antibiosis , Burkholderia/clasificación , Burkholderia/fisiología , Panax/microbiología , Microbiología del Suelo , Antibacterianos/farmacología , Composición de Base , Burkholderia/efectos de los fármacos , Burkholderia/genética , Burkholderia/aislamiento & purificación , Ácidos Grasos/análisis , Genes Bacterianos/genética , Datos de Secuencia Molecular , Fosfolípidos/análisis , Filogenia , República de Corea , Especificidad de la Especie

RESUMEN

BACKGROUND: Urinary tract infections (UTI) are one of the most common infections among women worldwide. E. coli often causes more than 75% of acute uncomplicated UTI, however, little is known about how recurrent UTIs and indiscriminate use of antimicrobials affect the aetiology of UTIs. This study aimed to establish the aetiology of UTI in a population of recurrent and self-medicated patients referred from pharmacies to a hospital in Hanoi, Vietnam and to describe genotypes and antimicrobial susceptibility of the associated bacterial pathogens. The aetiology of bacterial pathogens associated with UTI (defined as ≥ 104 CFU/ml urine) was established by phenotypic and molecular methods. Enterococcus faecalis isolates were typed by Multi Locus Sequence Typing (MLST), Pulsed-Field Gel Electrophoresis (PFGE) and antimicrobial susceptibility testing. METHODS: Urine samples from 276 patients suffering symptoms of urinary tract infection were collected and cultured on Flexicult agar® allowing for detection of the most common urine pathogens. Patients were interviewed about underlying diseases, duration of symptoms, earlier episodes of UTI, number of episodes diagnosed by doctors and treatment in relation to UTI. All tentative E. faecalis and E. faecium isolates were identified to species level by PCR, 16S rRNA and partial sequencing of the groEL gene. E. faecalis isolates were further characterized by Multi Locus Sequence Typing and antimicrobial susceptibility testing. RESULTS: Mean age of 49 patients was 48 yrs (range was 11-86 yrs) and included 94% women. On average, patients reported to have suffered from UTI for 348 days (range 3 days-10 years, and experienced 2.7 UTIs during the previous year). Cephalosporins were reported the second drug of choice in treatment of UTI at the hospital. E. faecalis (55.1%), E. coli (12.2%) and Streptococcus gallolyticus subsp. pasteurianus (8.2%) were main bacterial pathogens. MIC testing of E. faecalis showed susceptibility to ampicillin, penicillin and vancomycin, but high-level resistance against gentamicin (48.1%). MLST revealed 12 Sequence Types (ST) of which ST 16 made up 44.5% and showed closely related PFGE types. CONCLUSION: The different aetiology of UTI compared with reports elsewhere, where E. coli dominates, may be a result of chronic and recurrent UTIs together with indiscriminate use of antimicrobials. The similar genotypes shown by epidemiologically unrelated ST 16 isolates in Vietnam and elsewhere, suggest that E. faecalis ST 16 might represent a globally distributed clone. Treatment of UTI with cephalosporins may select for E. faecalis as it is intrinsic resistant and further studies are needed to establish the source(s) and role of E. faecalis ST 16 in acute UTI.

Asunto(s)

Antibacterianos/administración & dosificación , Infecciones Bacterianas/epidemiología , Infecciones Bacterianas/microbiología , Enterococcus/aislamiento & purificación , Streptococcus/aislamiento & purificación , Infecciones Urinarias/epidemiología , Infecciones Urinarias/microbiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Infecciones Bacterianas/tratamiento farmacológico , Niño , Electroforesis en Gel de Campo Pulsado , Enterococcus/clasificación , Enterococcus/efectos de los fármacos , Enterococcus/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/aislamiento & purificación , Femenino , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Tipificación de Secuencias Multilocus , Automedicación/métodos , Streptococcus/clasificación , Streptococcus/efectos de los fármacos , Streptococcus/genética , Infecciones Urinarias/tratamiento farmacológico , Vietnam/epidemiología , Adulto Joven

RESUMEN

Enterococcus spp. as pathogens have increased, but the sources of infection often remain unclear. To investigate whether poultry might be a reservoir for E. faecalis-associated urinary tract infections (UTIs) in humans, we characterized E. faecalis isolates from patients in Vietnam with UTIs during January 2008-January 2010 and poultry living in close contact with them by multilocus sequence typing (MLST), pulsed-field gel electrophoresis, analysis of antimicrobial drug susceptibility patterns, and sequencing of virulence genes. In 7 (23%) of 31 UTI cases, we detected identical MLST, indistinguishable or closely related pulsed-field gel electrophoresis patterns, and similar antimicrobial drug susceptibility patterns. Isolates from urine and poultry showed identical virulence gene profiles, except for 1 variation, and individual genes showed identical sequences. The homology of isolates from urine and poultry further indicates the zoonotic potential and global spread of E. faecalis sequence type 16, which recently was reported in humans with endocarditis and in pigs in Denmark.

Asunto(s)

Pollos/microbiología , Enterococcus faecalis/genética , Infecciones por Bacterias Grampositivas/epidemiología , Infecciones por Bacterias Grampositivas/microbiología , Enfermedades de las Aves de Corral/epidemiología , Infecciones Urinarias/epidemiología , Animales , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Electroforesis en Gel de Campo Pulsado , Enterococcus faecalis/aislamiento & purificación , Infecciones por Bacterias Grampositivas/veterinaria , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Aves de Corral/microbiología , Enfermedades de las Aves de Corral/microbiología , Análisis de Secuencia de ADN , Infecciones Urinarias/microbiología , Vietnam/epidemiología , Factores de Virulencia/genética , Zoonosis

RESUMEN

A serological diagnostic test using phenolic glycolipid-I (PGL-I) developed in the 1980s is commercially available, but the method is still inefficient in detecting all forms of leprosy. Therefore, more-specific and -reliable serological methods have been sought. We have characterized major membrane protein II (MMP-II) as a candidate protein for a new serological antigen. In this study, we evaluated the effectiveness of the enzyme-linked immunosorbent assay (ELISA) using the MMP-II antigen (MMP-II ELISA) for detecting antibodies in leprosy patients and patients' contacts in the mid-region of Vietnam and compared to the results to those for the PGL-I method (PGL-I ELISA). The results showed that 85% of multibacillary patients and 48% of paucibacillary patients were positive by MMP-II ELISA. Comparison between the serological tests showed that positivity rates for leprosy patients were higher with MMP-II ELISA than with PGL-I ELISA. Household contacts (HHCs) showed low positivity rates, but medical staff members showed comparatively high positivity rates, with MMP-II ELISA. Furthermore, monitoring of results for leprosy patients and HHCs showed that MMP-II is a better index marker than PGL-I. Overall, the epidemiological study conducted in Vietnam suggests that serological testing with MMP-II would be beneficial in detecting leprosy.

Asunto(s)

Anticuerpos Antibacterianos/sangre , Ensayo de Inmunoadsorción Enzimática , Lepra/diagnóstico , Proteínas de la Membrana/inmunología , Mycobacterium leprae/inmunología , Anticuerpos Antibacterianos/inmunología , Antígenos Bacterianos/inmunología , Glucolípidos/inmunología , Humanos , Sensibilidad y Especificidad

RESUMEN

A study aimed to strengthen the quality of medication that remains the nature of traditional medicine. New techniques applied in the researches. The inherit of traditional experiences and making up the preparation forms of traditional medications was a trend of studying new drugs as well as application of new researches.

Asunto(s)

Medicina , Medicina Tradicional