Recently, novel physical properties originating from quantum confinement endow the twodimensional (2D) transition metal dichalcogenides, such as MoS2, or WSe2 to attract a great deal of attention. However, the synthesis of 2D-TMDC has to be still limited, in which the precursors are almost based on high vapor pressure inorganic materials, that produce a smallscale film, and it is mainly performed only on conventional Si\SiO2 substrate. In this work, we successfully synthesize the atomic thickness of 2D-MoS2 films by using metal-organic chemical vapor deposition (MOCVD) on several kinds of substrate, namely silicon (Si), silicon dioxide (SiO2), graphite foil, or fluorine-doped tin oxide (FTO). The morphology of samples is observed by field emission scanning electron microscopy (FE-SEM), and scanning transmission electron microscopy (STEM). The lattice vibrational and optical properties are investigated by Raman and photoluminescence (PL) spectroscopies, respectively. With the same MOCVD growing condition, as-obtained samples exhibit the hexagonal configuration (2H phase), whereas the surface morphology and the thickness show a discrepancy, depending on the substrates.
In this study, a total of 380 raw meat samples (pork, beef, and chicken) were collected randomly from traditional markets in Ho Chi Minh City (Vietnam). Salmonella strains were isolated by cultivation methods according to ISO 6579-1:2017, and subsequently confirmed by PCR method (TCVN 8342:2010). These strains were used to test antibiotic susceptibility in six kinds of antibiotics belonging to two groups of quinolones (nalidixic, ciprofloxacin, and ofloxacin), and β-lactam antibiotics (ampicillin, amoxicillin, cephalexin) together with the detection of their resistant genotypes was estimated by Kirby-Bauer method and multiplex PCR. It was noted that the proportion of Salmonella spp. contaminated samples was 42.37% (161/380). Specifically, Salmonella spp. strains found in 50.00 % (63/126), 49.62% (65/131), and 26.83% (33/123) of pork, chicken, and beef samples, respectively. It was noticed that all isolated strains were resistant to six types of antibiotics. The highest proportion was 22.98% for ampicillin (AM), followed by 10.56% for nalidixic acid (NA). The proportions of amoxicillin/acid clavulanic (AMC), ceftazidime (CAZ), ciprofloxacin (CIP), and ofloxacin (OPX) resistant strains were remarkably low (< 10%). There were 37/161 (22.98%) Salmonella strains carrying TEM genes and 5/161 (3.11%) carrying CTX genes. On the other hand, there was no strain carrying SHV genes. Four quinolone-resistant genes including gyrA, gyrB involved in nalidixic acid resistance, and parC, parE involved in ofloxacin and ciprofloxacin resistance were detected in all Salmonella strains that also carried β-lactamase encoding genes. It is important to note that blaTEM-gyrA/B-parC/E genes were simultaneously found in all tested strains. While the proportion of strains containing blaCTX-gyrA/B-parC/E genes was 40.54%, the proportion of strains carrying blaTEM/CTX-gyrA/B-parC/E genes was 5.41%. The results revealed that raw meat might be contaminated with Salmonella spp. that are highly resistant to β-lactam antibiotics and quinolones. Henceforth, it is necessary to establish monitoring and surveillance programs on Salmonella spp. contamination and their antibiotic sensitivity in Vietnam to protect consumers’ health. The study also provided direct evidence for Salmonella contamination and antibiotic resistance situation in Ho Chi Minh City.
BACKGROUND: Rotator cuff tear (RCT) is a common injury of the shoulder, especially middle-aged people. Nonoperative treatment, cortisone injections are only effective at an early stage. Open surgery causes postoperative atrophy of the deltoid muscle, so results are limited. Arthroscopic rotator cuff repair surgery has been performed in Vietnam for about ten years, with many advantages such as the ability to accurately assess the lesions and less invasive procedure. In order to have a clearer view, we performed a mid-term assessment of the effectiveness of this surgery. AIM: Evaluate results over 2 years of patients with rotator cuff tears treated with arthroscopic surgery and their quality of life. METHOD: A group of 30 patients were diagnosed with RCT and surgery by arthroscopy to treat at Hanoi Medical University Hospital and Saint Paul Hospital between Jun 2015 and April 2017. The results of the surgeries were assessed by the degree of pain, muscle power, motion of the shoulder joint according to UCLA shoulder score. Evaluate the quality of life through the Rotator Cuff-Quality of Life (RC-QoL) index. RESULTS: The average age was 60.7 years. Female / male ratio was 1.3. Thirty-six months ± 6.41 was the average follow-up time (min 27 – max 50 months). The shoulder function is recorded according to UCLA has an average score of 30.9, therein good and excellent result were 90 %. The mean RC-QoL index was 91.5%. CONCLUSION: Treatment of RCT by arthroscopic surgery that has been evaluated for a minimum of 2 years follow-up showed good results and high quality of patient’s life.
In this report, we present the synthesis of low dimensional shell-core (2D\1D) nanostructures, in which the TiO2 nanorods (TNRs) as the core are covered by a continuous monolayer MoS2 (1L-MoS2) as the shell. The obtain 1L-MoS2\TNRs was directly grown on the conduct graphite foil without any transfer process, thus minimizing the charge transfer resistance from the electrode to the outer most working surface. For the first steps, the TiO2 seed layer was designed by the AF sputtering method, then the TNRs were grown by hydrothermal approach. Thereafter, the TNRs were conformally coated by a continuous monolayer MoS2 via a metal-organic chemical vapor deposition technique, resulting in 1L-MoS2\TNRs nanomaterial. The structural, vibrational, and morphological characteristics demonstrated that the samples are high crystallinity. Interestingly, the 1L-MoS2\TNRs showed highly efficient in electrochemical HER activity with the smallest onset overpotential of -140 mV vs RHE and a corresponding Tafel slope of 80 mV per decade, which were much lower compared to the pristine 1L-MoS2 and TNRs.
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