Tính chất đàn hồi và nhiệt động lực học của nano tinh thể cadmi selenide

The elastic and thermodynamic of zincblende CdSe nano crystals have been investigated by first-principles calculations based on density functional theory (DFT). The type of CdSe structure was optimized from the experimental parameter values. The mechanic characterization was determined based on the computed values of independent elastic constants C11, C12, and C44. The temperature dependence of a series of thermodynamic properties functions such as free energy, entropy, enthalpy, and heat capacity are calculated and analyzed in detail.Các tính chất đàn hồi và nhiệt động lực học của nano tinh thể (NC) cadmi selenide (CdSe) có cấu trúc zincblend đã được nghiên cứu trên cơ sở tính toán nguyên tắc ban đầu bằng phương pháp phiếm hàm mật độ (DFT). Thông số cấu trúc tinh thể được tối ưu hóa phù hợp với giá trị từ kết quả thực nghiệm. Các hệ số đặc trưng cho tính chất cơ học được xác định thông qua các giá trị tính toán ba hệ số đàn hồi độc lập C11, C12, C44. Sự phụ thuộc vào nhiệt độ của một số hệ số đặc trưng cho tính chất nhiệt động lực học như năng lượng tự do, entropy, entanpy và nhiệt dung cũng được khảo sát và phân tích một cách chi tiết

Transformation Chlorophyll a of Spirulina platensis to Chlorin e6 Derivatives and Several Applications

BACKGROUND: Spirulina platensis contains a large amount of chlorophylls, chlorophyll a, that are starting materials to synthesize functionalized chlorins. Chlorin e6 (Ce6) as well as its derivatives are second generation sensitizers using in photodynamic therapy (PDT) of various cancers. In this study, we transfer chlorophyll a of S. platensis to Ce6derivatives and determine their several applications. AIM: to evaluate the effects of Ce6 derivatives to treat cancer cells. METHODS: Ce6 trimethylester was created from methyl pheophorbide a2 in S. platensis provided by the Hidumi Company, Nghe An province, Viet Nam. Hela cells were incubated with Ce6 trimethylester and the irradiated with the diode laser dose of 1.2 J/cm2/min through the system of filters £ 650 nm. MTT assay and clonogenic assay were used to determine survival rate and cloning efficiency of cells. Antimicrobial effect of Ce6 trimethylester with halogen light were studied with Propionibacterium acnes VTCC 0218 and Staphylococcus aureus VTCC 0173. RESULTS: From dry biomass (700 g) of S. platensis, after extracting chlorophyll a and methanolysis, 4.2 g of methyl pheophorbide a was obtained. The reaction to give Ce6 trimethylester with 82% yield was performed with potassium hydroxide (KOH) in MeOH/THF/CHCl3. After irradiation with a 650 nm laser at 1.2 J, the cell viability in all samples decreased with Ce6 trimethylester treatment, the survival declining trend of Hela cells treated with Ce6 trimethylester were proportional when concentration of Ce6 trimethylester increased. The rate of colony formation was declined as the concentration of Ce6 trimethylester treated was increased. The growth of both S. aureus and P. acnes can be inactivated by Ce6 trimethylester PDT. The MIC99 value against P. acnes VTCC 0218 and S. aureus VTCC 0173 of Ce6 trimethylester with halogen light was 1.25 μg/ml. CONCLUSION: The Ce6 trimethylester from S. platensis cultivated in Viet Nam could be used as a potential photosentizer for photodynamic therapy for treatment of cancer and acne

Complete mitochondrial genome of Dong Tao chicken breed (Gallus gallus domesticus) of Vietnam

The complete mitochondrial genome of Dong Tao chicken breed (Gallus gallus domesticus, Dong Tao) was obtained by PCR and sequencing. The complete mitogenome was 16,783 bp in length, with the nucleotide composition for A, T, C, G was 30.29%, 23.75%, 32.48%, and 13.48%, respectively. The mitogenome of Dong Tao chicken contained a non-coding control region (D-loop), 2 rRNA genes, 13 protein-coding genes, and 22 tRNA genes. Phylogenetic analysis revealed that breed Dong Tao chicken breed was sister-close to G. gallus breed Guangxi, and paraphyletic to G. spadiceus, S. jabouillei, and a range of Chinese indigenous, ie. breeds Rugao and Taoyuan

Microscopic Observation Drug Susceptibility Assay (MODS) for Early Diagnosis of Tuberculosis in Children

MODS is a novel liquid culture based technique that has been shown to be effective and rapid for early diagnosis of tuberculosis (TB). We evaluated the MODS assay for diagnosis of TB in children in Viet Nam. 217 consecutive samples including sputum (n = 132), gastric fluid (n = 50), CSF (n = 32) and pleural fluid (n = 3) collected from 96 children with suspected TB, were tested by smear, MODS and MGIT. When test results were aggregated by patient, the sensitivity and specificity of smear, MGIT and MODS against “clinical diagnosis” (confirmed and probable groups) as the gold standard were 28.2% and 100%, 42.3% and 100%, 39.7% and 94.4%, respectively. The sensitivity of MGIT and MODS was not significantly different in this analysis (P = 0.5), but MGIT was more sensitive than MODS when analysed on the sample level using a marginal model (P = 0.03). The median time to detection of MODS and MGIT were 8 days and 13 days, respectively, and the time to detection was significantly shorter for MODS in samples where both tests were positive (P<0.001). An analysis of time-dependent sensitivity showed that the detection rates were significantly higher for MODS than for MGIT by day 7 or day 14 (P<0.001 and P = 0.04), respectively. MODS is a rapid and sensitive alternative method for the isolation of M.tuberculosis from children

Повышение цифровых навыков: ключ к цифровой вовлеченности пожилых людей (на примере Вьетнама)

Digital transformation taking place rapidly in all aspects of socioeconomic activities across Vietnam in recent years is affecting the lives of people of all ages. Vietnamese older people, due to the impact of digitization, demographic category and socioeconomic status as well as age-related issues, become vulnerable, facing many challenges in adapting to the digital environment. In the article, the existence of a digital divide within Vietnamese older persons at different levels and the disparities in digital skills that have a dominant influence on Internet usage and benefits have been confirmed; low basic digital skills was considered as a barrier to digital inclusion of older adults in the emerging digital society. The aim of the study is to predict the socio-economic consequences and find practical solutions to improve the literacy and disease skills of people in Vietnam, including the formation of an effective form of digital literacy and digital skills training. The article proposes measures to bridge the sudden gap in human diseases and encourage their adaptation to the emerging digital societyЦифровая трансформация, быстро происходящая во всех аспектах социально-экономической деятельности во Вьетнаме в последние годы, влияет на жизнь людей всех возрастов. Пожилые вьетнамцы под влиянием цифровизации, объективных демографических и социально-экономических процессов, а также проблем, связанных с возрастом, становятся уязвимыми, сталкиваясь со многими проблемами при адаптации к цифровой среде. В статье подтверждается наличие цифрового неравенства среди пожилых вьетнамцев на разных уровнях овладения цифровыми навыками, которые оказывают доминирующее влияние на использование преимуществ сети Интернет. В ходе исследования установлено, что низкие базовые цифровые навыки послужили препятствием для интеграции пожилых людей в развивающееся цифровое общество. Цель исследования заключается в прогнозировании социально-экономических последствий и поиске практических решений по повышению цифровой грамотности и навыков пожилых людей Вьетнама, включая становление эффективных форм распространения цифровой грамотности и обучения цифровым навыкам. В статье предложены меры по преодолению цифрового разрыва среди пожилых людей и поощрению их адаптации к формирующемуся цифровому обществ

Rifampicin resistant 'Mycobacterium tuberculosis' in Vietnam, 2020–2022

Objective: We conducted a descriptive analysis of multi-drug resistant tuberculosis (MDR-TB) in Vietnam’s two largest cities, Hanoi and Ho Chi Minh city. Methods: All patients with rifampicin resistant tuberculosis were recruited from Hanoi and surrounding provinces between 2020 and 2022. Additional patients were recruited from Ho Chi Minh city over the same time period. Demographic data were recorded from all patients, and samples collected, cultured, whole genome sequenced and analysed for drug resistance mutations. Genomic susceptibility predictions were made on the basis of the World Health Organization’s catalogue of mutations in Mycobacterium tuberculosis associated with drug resistance, version 2. Comparisons were made against phenotypic drug susceptibility test results where these were available. Multivariable logistic regression was used to assess risk factors for previous episodes of tuberculosis. Results: 233/265 sequenced isolates were of sufficient quality for analysis, 146 (63 %) from Ho Chi Minh City and 87 (37 %) from Hanoi. 198 (85 %) were lineage 2, 20 (9 %) were lineage 4, and 15 (6 %) were lineage 1. 17/211 (8 %) for whom HIV status was known were infected, and 109/214 (51 %) patients had had a previous episode of tuberculosis. The main risk factor for a previous episode was HIV infection (odds ratio 5.1 (95 % confidence interval 1.3–20.0); p = 0.021). Sensitivity for predicting first-line drug resistance from whole genome sequencing data was over 90 %, with the exception of pyrazinamide (85 %). For moxifloxacin and amikacin it was 50 % or less. Among rifampicin-resistant isolates, prevalence of resistance to each non-first-line drug was < 20 %. Conclusions: Drug resistance among most MDR-TB strains in Vietnam’s two largest cities is confined largely to first-line drugs. Living with HIV is the main risk factor among patients with MDR-TB for having had a previous episode of tuberculosis

Comparative Susceptibility of Aedes albopictus and Aedes aegypti to Dengue Virus Infection After Feeding on Blood of Viremic Humans: Implications for Public Health.

Aedes albopictus is secondary to Aedes aegypti as a vector of dengue viruses (DENVs) in settings of endemicity, but it plays an important role in areas of dengue emergence. This study compared the susceptibility of these 2 species to DENV infection by performing 232 direct blood-feeding experiments on 118 viremic patients with dengue in Vietnam. Field-derived A. albopictus acquired DENV infections as readily as A. aegypti after blood feeding. Once infected, A. albopictus permitted higher concentrations of DENV RNA to accumulate in abdominal tissues, compared with A. aegypti. However, the odds of A. albopictus having infectious saliva were lower than the odds observed for A. aegypti (odds ratio, 0.70; 95% confidence interval, .52-.93). These results quantitate the susceptibility of A. albopictus to DENV infection and will assist parameterization of models for predicting disease risk in settings where A. albopictus is present

Evaluation of microscopic observation drug susceptibility assay for diagnosis of multidrug-resistant Tuberculosis in Viet Nam

<p>Abstract</p> <p>Background</p> <p>Early diagnosis of tuberculosis (TB) and multidrug resistant tuberculosis (MDR TB) is important for the elimination of TB. We evaluated the microscopic observation drug susceptibility (MODS) assay as a direct rapid drug susceptibility testing (DST) method for MDR-TB screening in sputum samples</p> <p>Methods</p> <p>All adult TB suspects, who were newly presenting to Pham Ngoc Thach Hospital from August to November 2008 were enrolled into the study. Processed sputum samples were used for DST by MODS (DST-MODS) (Rifampicin (RIF) 1 μg/ml and Isoniazid (INH) 0.4 μg/ml), MGIT culture (Mycobacterial Growth Indicator Tube) and Lowenstein Jensen (LJ) culture. Cultures positive by either MGIT or LJ were used for proportional DST (DST-LJ) (RIF 40 μg/ml and INH 0.2 μg/ml). DST profiles on MODS and LJ were compared. Discrepant results were resolved by multiplex allele specific PCR (MAS-PCR).</p> <p>Results</p> <p>Seven hundred and nine TB suspects/samples were enrolled into the study, of which 300 samples with DST profiles available from both MODS and DST-LJ were analyzed. Cording in MODS was unable to correctly identify 3 Mycobacteria Other Than Tuberculosis (MOTT) isolates, resulting in 3 false positive TB diagnoses. None of these isolates were identified as MDR-TB by MODS. The sensitivity and specificity of MODS were 72.6% (95%CI: 59.8, 83.1) and 97.9% (95%CI: 95.2, 99.3), respectively for detection of INH resistant isolates, 72.7% (95%CI: 30.9, 93.7) and 99.7% (95%CI: 98.1, 99.9), respectively for detecting RIF resistant isolates and 77.8% (95%CI: 39.9, 97.1) and 99.7% (95%CI: 98.1, 99.9), respectively for detecting MDR isolates. The positive and negative predictive values (PPV and NPV) of DST-MODS were 87.5% (95%CI: 47.3, 99.6) and 99.3% (95%CI: 97.5, 99.9) for detection of MDR isolates; and the agreement between MODS and DST-LJ was 99.0% (kappa: 0.8, <it>P </it>< 0.001) for MDR diagnosis. The low sensitivity of MODS for drug resistance detection was probably due to low bacterial load samples and the high INH concentration (0.4 μg/ml). The low PPV of DST-MODS may be due to the low MDR-TB rate in the study population (3.8%). The turnaround time of DST-MODS was 9 days and 53 days for DST-LJ.</p> <p>Conclusion</p> <p>The DST-MODS technique is rapid with low contamination rates. However, the sensitivity of DST-MODS for detection of INH and RIF resistance in this study was lower than reported from other settings.</p