A Rare Case of Urinary Retention Due to Prostate Tuberculosis in Vietnam.

Prostate tuberculosis is a rare clinical form of extrapulmonary tuberculosis, which causes acute urinary retention infrequently. Cases of prostate tuberculosis reported in the literature often show slow progression with insidious pre-existing urinary disturbances. It can pose a diagnostic dilemma, and the treatment protocols can be challenging. Most clinical cases are managed by antitubercular medications, and surgery is usually reserved for cases where medical treatment fails. Here, we present the case of a 62-year-old male patient who presented to the hospital with acute urinary retention, with a history of dysuria for three months. Ultrasound and magnetic resonance imaging showed enlarged prostate pushing into the bladder lumen with an increasing signal of the parenchyma on T2-weighted imaging. In addition, some lymph nodes were noted near the bilateral iliac vessels pointing toward a chronic inflammation condition with elevated prostatic-specific antigen (4.5 ng/mL). Therefore, transurethral resection of the prostate was carried out for voiding purposes, and the biopsy was sent to the pathology laboratory to rule out malignancy. Intraoperative images revealed a prostatic urethral mass (12 mm × 15 mm × 32 mm) pushing into the bladder lumen, and the histopathological results confirmed the diagnosis of prostate tuberculosis. The patient received a six-month course of antitubercular medications immediately after surgery with a regimen of rifampicin, isoniazid, pyrazinamide, and ethambutol daily for two months, maintaining daily for four months with rifampicin, isoniazid, and ethambutol. Follow-up treatment was conducted two years later, and the results showed a good response with no recurrence. Prostate tuberculosis is best managed with antitubercular chemotherapy, but surgery is unavoidable for acute complications such as urinary obstruction, as seen in this case.

Insights into Electronucleation and Electrodeposition of Nickel from a Non-aqueous Solvent Based on NiCl2·6H2O Dissolved in Ethylene Glycol.

This work deals with nickel electronucleation and growth processes onto a glassy carbon electrode from NiCl2·6H2O dissolved in ethylene glycol (EG) solutions with and without 250 mM NaCl as a supporting electrolyte. The physicochemical properties of EG solutions, namely, viscosity and conductivity, were determined for different Ni(II) concentrations. From cyclic voltammetry, it was found that in the absence of the supporting electrolyte, the cathodic efficiency of Ni electrodeposition is about 88%; however, in the presence of the supporting electrolyte, the cathodic efficiency was reduced to 26% due to water (added along the supporting electrolyte) reduction on the growing surfaces of Ni nuclei. This side reaction produced both H2(g) and OH- ions. Part of the former was occluded in Ni, and the latter reacted with Ni(II) ions in EG forming passivation products such as Ni(OH)2(s). Moreover, it was shown that metallic Ni did not catalyze the EG reduction in this system. From chronoamperometry, it was shown that in the absence of the supporting electrolyte, the amount of Ni electrodeposits, for the same overpotential and time, was higher than in the presence of the supporting electrolyte. The j-t plots recorded in the latter system, for different Ni(II) concentrations, were analyzed using a model which involves a contribution due to multiple 3D nucleation and diffusion-controlled growth and another related to the simultaneous reduction of water on the Ni nuclei growing surfaces. This model allows not only the quantification of the Ni nucleation kinetic parameters but also the effective deconvolution of the individual contributions to the total current; thus, from the integration of the j-t plots of these contributions, it was demonstrated that the charge amount of each process depends on the Ni(II) concentration. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, micro-Raman spectroscopy, and X-ray photoelectron spectroscopy revealed the presence of pure Ni nanoparticles electrodeposited on the electrode surface. Moreover, X-ray measurements verified the formation of a high-crystallinity face-centered cubic structure with preferred orientation growth on the ⟨111⟩ direction, which were also corroborated by the magnetic measurement performed in a physical property measurement system.

Low-operating temperature and remarkably responsive methanol sensors using Pt-decorated hierarchical ZnO structure.

Highly responsive methanol sensors working at low temperatures are developed using hierarchical ZnO nanorods decorated by Pt nanoparticles. The sensing materials are fabricated following a 3-step process: electrospinning of ZnO nanofibers, hydrothermal growth of hierarchical ZnO nanorods on the nanofibers and UV-assisted deposition of Pt nanoparticles. The morphology, structure and properties of the materials are examined by field-effect scanning electron microscopy, transmission electron microscope, x-ray diffraction, x-ray photoelectron spectroscopy, UV-Vis absorption spectroscopy, and electrical measurements. The methanol sensing performance is investigated at different working temperatures in the range of 110 °C-260 °C. It is observed that the surface modification of the ZnO hierarchical nanorods by Pt nanoparticles results in a remarkable enhancement of the sensing response toward methanol, which can reach approximately 19 500 times higher than that of the unmodified ZnO nanorods-based sensor. In addition, this modification enables lower working temperatures with an optimum range of 140 °C-200 °C. Based on the achieved results, a methanol sensing mechanism of the Pt/ZnO structure is proposed.

MoS2 nanosheets-decorated SnO2 nanofibers for enhanced SO2 gas sensing performance and classification of CO, NH3 and H2 gases.

The effect of MoS2 nanosheet (NS) decoration on the gas-sensing properties of SnO2 nanofibers (NFs) was investigated. The decorated sensors were fabricated by facile on-chip electrospinning technique and subsequently dropping MoS2 NSs-dispersed solution. The MoS2 NS decoration resulted in enhanced the response and reduced the operating temperature of SnO2 NFs towards SO2 gas. The SnO2 NF sensor decorated with the optimum density of MoS2 NSs exhibited about 10-fold enhancement in gas response to 10 ppm SO2 at 150 °C as compared with the bare SnO2 NF sensor. Furthermore, the decorated sensors exhibited an extremely low detection limit and good selectivity for SO2 gas against other interfering gases, such as CO, NH3, and H2. The enhanced SO2 gas-sensing performance of MoS2 NSs-decorated SnO2 NFs was attributed to the chemical sensitization of MoS2 NSs and charge transfer through heterojunctions between the NSs and SnO2 nanograins. The classification of toxic gases such as CO, H2, and NH3 by the MoS2 NSs-decorated SnO2 NF sensors can achieve high accuracy with linear discriminant analysis (LDA). Our results suggest that the one-dimensional nanostructures of semiconductor metal oxides decorated with two-dimensional transition metal dichalcogenides are attractive candidates for the detection of hazardous gases.

Enhanced NH3 and H2 gas sensing with H2S gas interference using multilayer SnO2/Pt/WO3 nanofilms.

The selective detection and classification of NH3 and H2S gases with H2S gas interference based on conventional SnO2 thin film sensors is still the main problem. In this work, three layers of SnO2/Pt/WO3 nanofilms with different WO3 thicknesses (50, 80, 140, and 260 nm) were fabricated using the sputtering technique. The WO3 top layer were used as a gas filter to further improve the selectivity of sensors. The effect of WO3 thickness on the (NH3, H2, and H2S) gas-sensing properties of the sensors was investigated. At the optimal WO3 thickness of 140 nm, the gas responses of SnO2/Pt/WO3 sensors toward NH3 and H2 gases were slightly lower than those of Pt/SnO2 sensor film, and the gas response of SnO2/Pt/WO3 sensor films to H2S gas was almost negligible. The calcification of NH3 and H2 gases was effectively conducted by machine learning algorithms. These evidences manifested that SnO2/Pt/WO3 sensor films are suitable for the actual NH3 detection of NH3 and H2S gases.

Coping strategies and social support among caregivers of patients with cancer: a cross-sectional study in Vietnam.

Research on coping strategies and social support among Vietnamese cancer caregivers remains limited. In this study, we aim to examine the relationships between types of coping strategies utilized and social support among cancer caregivers. This was a cross-sectional study conducted in three main cancer hospitals in the Northern, Central and Southern regions of Vietnam. The 28-item Brief COPE Inventory (BCI) Scale and the Multidimensional Scale of Perceived Social Support (MSPSS) were utilized. Descriptive statistics and multivariate linear regression were performed. Active coping, acceptance and positive reframing were the most used coping strategies among participants, while substance use was the least commonly used. Level of social support was positively correlated with the utilization of coping mechanisms. Receiving high social support and utilizing positive coping strategies enables caregivers to mitigate their caregiving burden, control the situation and enhance their own quality of life.

Controlled synthesis of ultrathin MoS2 nanoflowers for highly enhanced NO2 sensing at room temperature.

Fabrication of a high-performance room-temperature (RT) gas sensor is important for the future integration of sensors into smart, portable and Internet-of-Things (IoT)-based devices. Herein, we developed a NO2 gas sensor based on ultrathin MoS2 nanoflowers with high sensitivity at RT. The MoS2 flower-like nanostructures were synthesised via a simple hydrothermal method with different growth times of 24, 36, 48, and 60 h. The synthesised MoS2 nanoflowers were subsequently characterised by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, energy-dispersive X-ray spectroscopy and transmission electron microscopy. The petal-like nanosheets in pure MoS2 agglomerated to form a flower-like structure with Raman vibrational modes at 378 and 403 cm-1 and crystallisation in the hexagonal phase. The specific surface areas of the MoS2 grown at different times were measured by using the Brunauer-Emmett-Teller method. The largest specific surface area of 56.57 m2 g-1 was obtained for the MoS2 nanoflowers grown for 48 h. This sample also possessed the smallest activation energy of 0.08 eV. The gas-sensing characteristics of sensors based on the synthesised MoS2 nanostructures were investigated using oxidising and reducing gases, such as NO2, SO2, H2, CH4, CO and NH3, at different concentrations and at working temperatures ranging from RT to 150 °C. The sensor based on the MoS2 nanoflowers grown for 48 h showed a high gas response of 67.4% and high selectivity to 10 ppm NO2 at RT. This finding can be ascribed to the synergistic effects of largest specific surface area, smallest crystallite size and lowest activation energy of the MoS2-48 h sample among the samples. The sensors also exhibited a relative humidity-independent sensing characteristic at RT and a low detection limit of 84 ppb, thereby allowing their practical application to portable IoT-based devices.

Dip-coating decoration of Ag2O nanoparticles on SnO2 nanowires for high-performance H2S gas sensors.

SnO2 nanowires (NWs) are used in gas sensors, but their response to highly toxic gas H2S is low. Thus, their performance toward the effective detection of low-level H2S in air should be improved for environmental-pollution control and monitoring. Herein, Ag2O nanoparticle decorated SnO2 NWs were prepared by a simple on-chip growth and subsequent dip-coating method. The amount of decorated Ag2O nanoparticles on the surface of SnO2 NWs was modified by changing the concentration of AgNO3 solution and/or dipping times. Gas-sensing measurements were conducted at various working temperatures (200-400 °C) toward different H2S concentrations ranging within 0.1-1 ppm. The selectivity of Ag2O-decorated SnO2 NW sensors for ammonia and hydrogen gases was tested. Results confirmed that the Ag2O-decorated SnO2 NW sensors had excellent response, selectivity, and reproducibility. The gas-sensing mechanism was interpreted under the light of energy-band bending by sulfurization, which converted the p-n junction into n-n, thereby significantly enhancing the sensing performance.

Self-heated Ag-decorated SnO2 nanowires with low power consumption used as a predictive virtual multisensor for H2S-selective sensing.

Multisensor systems with low-power consumption are emerging for the Internet of Things. In this work, we demonstrate the use of self-heated networked Ag-decorated SnO2 NW sensors integrated into a portable module for selective detection of H2S gas at low power consumption, and the integrated system is simulated as a virtual multisensor under varying heating powers for identifying and quantifying different reducing gases. The H2S gas-sensing characterisations at the different self-heating powers of 2-10 mW showed that the gas response significantly increased with the increase in Ag density decoration and the heated power strongly affected the gas-sensing performance and sensor stability. Excellent response of 21.2 to 0.5 ppm H2S gas was obtained at a low heating power of 2 mW with an acceptable response/recovery time of 18/980 s. The increase of the heating power over 20 mW can destroy the devices. The integrated system could selectively detect H2S at the heating power below 4 mW and H2, C2H5OH and NH3 gases at the heating power upon 4 mW. The virtual multisensor could discriminate qualitatively (with an accuracy of 100%) and quantitatively H2S, H2, NH3, C2H5OH (Ethanol) and CH3COCH3 (Aceton) gases with average errors of 13.5%, 14.7%, 16.8%, 16.9%, and 14.8%, respectively. The proposed sensing platform is a promising candidate for selective detection of H2S gas and virtual multisensor with low power consumption for mobile or wireless network devices.

An effective H2S sensor based on SnO2 nanowires decorated with NiO nanoparticles by electron beam evaporation.

The highly toxic hydrogen sulphide (H2S) present in air can cause negative effects on human health. Thus, monitoring of this gas is vital in gas leak alarms and security. Efforts have been devoted to the fabrication and enhancement of the H2S-sensing performance of gas sensors. Herein, we used electron beam evaporation to decorate nickel oxide (NiO) nanoparticles on the surface of tin oxide (SnO2) nanowires to enhance their H2S gas-sensing performance. The synthesised NiO-SnO2 materials were characterised by field-emission scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy analysis. H2S gas-sensing characteristics were measured at various concentrations (1-10 ppm) at 200-350 °C. The results show that with effective decoration of NiO nanoparticles, the H2S gas-sensing characteristics of SnO2 nanowires are significantly enhanced by one or two orders compared with those of the bare material. The sensors showed an effective response to low-level concentrations of H2S in the range of 1-10 ppm, suitable for application in monitoring of H2S in biogas and in industrial controls. We also clarified the sensing mechanism of the sensor based on band structure and sulphurisation process.

Konjac glucomannan-templated synthesis of three-dimensional NiO nanostructures assembled from porous NiO nanoplates for gas sensors.

Biopolymer template synthesis has attracted extensive interest for fabricating highly porous metal oxide nanostructures. In this report, a green template-based approach for the synthesis of three-dimensional (3D) NiO nanostructures assembled from porous NiO nanoplates is introduced using a konjac glucomannan (KGM) template. The Ni-KGM composites, which were formed by the immersion of KGM nanofibrils in nickel nitrate solution, were annealed in air at 600 °C to obtain the highly porous NiO nanoplates. The KGM nanofibrils were used as a sacrificial template, which was combusted at a high temperature for the formation of the porous nanostructures. The gas sensor properties of the porous NiO architecture were systematically investigated with four reduced gases including hydrogen sulfide, ammonia, carbon monoxide and hydrogen. The results indicate that the porous NiO nanoplates show a good detection of hydrogen sulfide with a rapid response and recovery speed at low concentrations.

Magnetic iron oxide nanoparticles decorated graphene for chemoresistive gas sensing: The particle size effects.

We report a synthesis of magnetic nanoparticles chemically immobilized onto reduced graphene oxide sheets (referred to as rGO-Fe3O4 NPs) as a gas and vapor sensing platform with precisely designed particle size of 5, 10 and 20 nm to explore their influence of particle size on sensing performance. The rGO-Fe3O4 NP sensors have been investigated their responses to different gases and volatile organic compounds (VOCs) at part-per-million (ppm) levels. Results show that the Fe3O4 NPs with smaller size (5 and 10 nm) on the rGO surface led to a lower sensitivity, while particles of a size of 20 nm have a significant enhancement of sensitivity compared to the bare rGO sensor. The rGO-Fe3O4 NP20 sensor can detect trace amounts of NO2 gas and ethanol vapor at the 1 ppm and is highly selective to the NO2 and ethanol among other tested gases and VOCs, respectively. The particle size causes different distribution behaviour of NPs over rGO surface and interspaced between them, which results in deceased or increased the surface interactions between gas and graphene. The NPs themselves contained different defects level and the charge depletion layer that affect their adsorption gas/vapor molecules, which are explained for different sensing responses.

Facile on-chip electrospinning of ZnFe2O4 nanofiber sensors with excellent sensing performance to H2S down ppb level.

ZnFe2O4 nanofiber gas sensors are cost-effectively fabricated by direct electrospinning on microelectrode chip with Pt interdigitated electrodes and subsequent calcination under different conditions to maximize their response to H2S gas. The synthesized nanofibers of approximately 30-100 nm in diameter show typical spider-net-like morphology of the electrospun nanofibers. The ZnFe2O4 nanofibers comprise many 10-25 nm nanograins, which results in multi-porous structures. Moreover, the nanofibers exhibit the single phase of cubic-spinel-structure ZnFe2O4. The density, crystallinity and grain size of ZnFe2O4 nanofiber that strongly affect gas-sensing properties can be optimized by controlling electrospun time, annealing temperature, annealing time and heating rate. Under optimal conditions, the ZnFe2O4 nanofiber sensors exhibit high sensitivity and selectivity to H2S at sub-ppm levels. Excellent gas-sensing performances are attributed to effects of multi-porous structure, nanograin size and crystallinity, which is explained by the sensing mechanisms of ZnFe2O4 nanofiber sensors to H2S gas.

A comparative study on the electrochemical properties of nanoporous nickel oxide nanowires and nanosheets prepared by a hydrothermal method.

Metal oxide nanostructures have been extensively used in electrochemical devices due to their advantages, including high active surface area and chemical stability. However, the electrochemical properties of metal oxides are strongly dependent on their structural characteristics. We performed a comparative study on the electrochemical performance of nanoporous nickel oxide (NiO) nanosheets and nanowires. The advanced nanoporous NiO nanomaterials were synthesized by a facile hydrothermal method followed by thermal calcination. The synthesized nanomaterials, as characterized by scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, X-ray diffraction, and nitrogen adsorption/desorption isotherms, demonstrated the nanoporosity and high crystallinity of the NiO nanosheets and nanowires. Cyclic voltammetry measurement was performed using a three-electrode system to evaluate the electrochemical properties of the synthesized materials. Results showed that the nanoporous NiO nanosheets possessed a higher current density than that of the nanowires by approximately ten times. Moreover, the nanoporous NiO nanosheets showed exceptionally high stability of almost 100%, after three cycles in strong alkaline environments, thereby suggesting possible application in electrochemical devices.

C2H5OH and NO2 sensing properties of ZnO nanostructures: correlation between crystal size, defect level and sensing performance.

ZnO nanostructures can be synthesized using different techniques for gas sensor applications, but different synthesis methods produce different morphologies, specific surface areas, crystal sizes, and physical properties, which consequently influence the gas-sensing properties of materials. Many parameters such as morphology, specific surface areas, crystal sizes, and defect level can influence the gas-sensing properties of ZnO nanostructures. However, it is not clear which parameter dominates the gas-sensing performance. This study clarified the correlation between crystal size, defect level, and gas-sensing properties of ZnO nanostructures prepared from hydrozincite counterparts by means of field emission scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction and photoluminescence spectra. Results showed that the average crystal size of the ZnO nanoparticles increased with thermal decomposition temperatures from 500 °C to 700 °C. However, the sample treated at 600 °C, which has the lowest visible-to-ultraviolet band intensity ratio showed the highest response to ethanol and NO2. These results suggested that defect level but not size is the main parameter dominating the sensor performance. The gas sensing mechanism was also elucidated on the basis of the correlation among decomposition temperatures, crystal size, defect level, and gas sensitivity.

Ultralow power consumption gas sensor based on a self-heated nanojunction of SnO2 nanowires.

The long duration of a working device with a limited battery capacity requires gas sensors with low power consumption. A self-heated gas sensor is a highly promising candidate to satisfy this requirement. In this study, two gas sensors with sparse and dense SnO2 nanowire (NW) networks were investigated under the Joule heating effect at the nanojunction. Results showed that the local heating nanojunction was effective for NO2 sensing but generally not for reduction gases. At 1 µW, the sparse NW sensor showed a good sensing performance to the NO2 gas. The dense SnO2 NW network required a high-power supply for gas-sensitive activation, but was suitable for reduction gases. A power of approximately 500 µW was also needed for a fast recovery time. Notably, the dense NW sensor can response to ethanol and H2S gases. Results also showed that the self-heated sensors were simple in design and reproducible in terms of the fabrication process.

Biological Characteristics and Antimicrobial Activity of Endophytic Streptomyces sp. TQR12-4 Isolated from Elite Citrus nobilis Cultivar Ham Yen of Vietnam.

Ham Yen orange (Citrus nobilis Lour) is the highly valuable commercial fruit of Vietnam. With the blooming of fruit production and farming area, this specialty crop is facing threats from several serious diseases; therefore the search for new effective biocontrollers is required to prevent the existing excessive use of fertilizers and plant protection chemicals. Endophytic actinomycetes are of great scientific interest due to their high potential of application in agriculture and pharmaceutical research. In this work, endophytic actinomycetes were isolated from a native orange species of Northeast mountainous province Tuyen Quang. Among 49 isolates obtained, the isolate TQR12-4 strongly inhibited test pathogens Colletotrichum truncatum, Geotrichum candidum, Fusarium oxysporum, and F. udum. This isolate gave comparatively high biomass yields on different substrates, for example, carboxy methyl cellulose, starch, protein, and chitin, within a wide range of temperature from 15 to 45°C and pH from 4 to 10. Sequence analysis of 16S rDNA gene showed that TQR12-4 shared 99% similarity to Streptomyces prasinopilosus; however, it slightly differed from the latter in spore morphology and hence was named as Streptomyces sp. TQR12-4. A thermostable antifungal substance of nonpeptide nature produced by Streptomyces sp. TQR12-4 had MIC against Fusarium udum of 100 µg/mL and 400 µg/mL respective to extract fractions X4 and X5.

Liver Cancer Detection by a Simple, Inexpensive and Effective Immunosensor with Zinc Oxide Nanoparticles.

Regular monitoring of blood α-fetoprotein (AFP) and/or carcino-embryonic antigen (CEA) levels is important for the routine screening of liver cancer. However, AFP and CEA have a much lower specificity than des-γ-carboxyprothrombin (DCP) to detect liver cancer. Therefore, the study reported here was designed, to develop a screen-printed DCP immunosensor incorporating zinc oxide nanoparticles, for accurate determination of DCP. The designed immunosensor shows low detection limits for the detection of DCP: 0.440 ng/mL (based on impedance measurement), 0.081 ng/mL (based on real part of impedance measurement) and 0.078 ng/mL (based on imaginary part of impedance measurement), within the range of 3.125 ng/mL to 2000 ng/mL. In addition, there was little interference to DCP determination by molecules such as Na⁺, K⁺, Ca(2+), Cl(-), glucose, urea, and uric acid. It is therefore concluded that the DCP immunosensor developed and reported here is simple, inexpensive and effective, and shows promise in the rapid screening of early-stage liver cancer at home with a point-of-care approach.

Comparative study on CO2 and CO sensing performance of LaOCl-coated ZnO nanowires.

Carbon dioxide (CO(2)) and carbon monoxide (CO) emissions from industries and combustion fuels such as coal, oil, hydrocarbon, and natural gases are increasing, thus causing environmental pollution and climate change. The selective detection of CO(2) and CO gases is important for environmental monitoring and industrial safety applications. In this work, LaOCl-coated ZnO nanowires (NWs) sensors are fabricated and characterized for the detection of CO(2) (250-4000 ppm) and CO (10-200 ppm) gases at different operating temperatures. The effects of the LaCl(3) coating concentration and calcination temperature of the sensors are studied. They are found to have a strong influence on the sensing performance to CO(2) gas, but a relatively slight influence on that to CO. The LaOCl coating enhances the response and shortens the response and recovery times to CO(2) compared with those to CO. The enhanced response of the LaOCl-coated ZnO NW sensors is attributed to the extension of the electron depletion layer due to the formation of p-LaOCl/n-ZnO junctions on the surfaces of the ZnO NWs.