80 research outputs found

    Modulation and application of chitosal to adsorb lead (Pb2+) in waterwaste

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    One of methods to eliminate metals from water is the use of adsorption. Chitosal is a material with a biological origin and was chosen for this study. The material was extracted from shrimp shells. The final product of the extraction progress was chitosal gel with a diameter of 3.5 mm, 97% of purity and good solubility in 1% CH3COOH solution. Three adsorption columns were built with PVC plastic. Two experiments at lead concentration 6.98 mg/l and 15.7 mg/l were carried out with the flow from the top down, at different water retention times of 15 minutes, 30 minutes, 45 minutes, 60 minutes, 90 minutes, and 120 minutes. The results showed that at lead concentrations of 6.98 mg/l we did not find the optimum water retention time. However, in the second experiment with lead concentration of 15.7 mg/l we determined the optimal water retention time was 60 minutes for column h1 and the lead adsorption efficiency achieved was 30.44%; column h2, h3 were the same time (90 minutes) and the lead adsorption efficiency reached 44.71%; and 52.87% respectively

    Seasonal variation of phytoplankton in My Thanh River, Mekong delta, Vietnam

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    A study on the seasonal variation of phytoplankton composition was conducted at the upper, middle, and lower parts of the My Thanh River, which supplies an important source of water for aquaculture. Qualitative and quantitative samples of phytoplankton were collected monthly at both high and low tide. The results showed that a total of 171 phytoplankton (algae) species were recorded, belonging to 59 genera and 5 phyla. Diatoms were the most abundant group with the highest species number, followed by green algae. The other phyla possessed a lower number of species. The species composition was more diverse in the rainy season and at high tide at most of the sampling sites. The mean density of algae varied from 30,900-43,521 ind.L^-1^. The density of diatoms was higher in the middle and lower parts. At the same time, euglenoids displayed the highest density in the upper part, showing a difference in the dominant algae group under the influence of salinity. Salinity was found to be significantly positively correlated (p<0.01) with diatoms, whereas it was negatively correlated (p<0.05) with blue-green algae and euglenoids. The algae composition was quite diverse, with the H' index ranging from 2.0-3.3, showing the water quality was slightly to moderately polluted

    Culturally adaptive storytelling intervention versus didactic intervention to improve hypertension control in Vietnam- 12 month follow up results: A cluster randomized controlled feasibility trial

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    INTRODUCTION: Vietnam is experiencing an epidemiologic transition with an increased prevalence of non-communicable diseases. The country needs novel, large-scale, and sustainable interventions to improve hypertension control. We report the 12 month follow-up results of a cluster randomized feasibility trial in Hung Yen province, Vietnam, which evaluated the feasibility and acceptability of two community-based interventions to improve hypertension control: a storytelling and a didactic intervention. METHODS: The storytelling intervention included stories in the patients\u27 own words about coping with hypertension and didactic content about the importance of healthy lifestyle behaviors in controlling elevated blood pressure levels. The didactic intervention included only didactic content, which were general recommendations for managing several important risk factors for hypertension and other non-communicable diseases. The storytelling intervention was delivered by two DVDs three months apart; the didactic intervention included only one DVD. The trial was conducted in patients with poorly controlled hypertension from 4 communes (communities), which were equally randomized to the two interventions. RESULTS: The mean age of the 160 patients was 66 years and 54% were men. Between baseline enrollment and the 12 month follow-up, mean systolic blood pressure declined by 10.8 mmHg (95% CI: 6.5-14.9) in the storytelling group and by 5.8 mmHg (95% CI: 1.6-10.0) in the didactic content group. The storytelling group also experienced more improvement in several health behaviors, including increased levels of physical activity and reduced consumption of salt and alcohol. CONCLUSIONS: We observed considerable long-term beneficial effects of both interventions, especially of our storytelling intervention, among patients with inadequately controlled hypertension. A large scale randomized trial should more systematically compare the short and long-term effectiveness of the two interventions in controlling hypertension. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02483780

    Differentiation of breast cancer stem cells by knockdown of CD44: promising differentiation therapy

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    <p>Abstract</p> <p>Background</p> <p>Breast cancer stem cells (BCSCs) are the source of breast tumors. Compared with other cancer cells, cancer stem cells show high resistance to both chemotherapy and radiotherapy. Targeting of BCSCs is thus a potentially promising and effective strategy for breast cancer treatment. Differentiation therapy represents one type of cancer stem-cell-targeting therapy, aimed at attacking the stemness of cancer stem cells, thus reducing their chemo- and radioresistance. In a previous study, we showed that down-regulation of CD44 sensitized BCSCs to the anti-tumor agent doxorubicin. This study aimed to determine if CD44 knockdown caused BCSCs to differentiate into breast cancer non-stem cells (non-BCSCs).</p> <p>Methods</p> <p>We isolated a breast cancer cell population (CD44<sup>+</sup>CD24<sup>- </sup>cells) from primary cultures of malignant breast tumors. These cells were sorted into four sub-populations based on their expression of CD44 and CD24 surface markers. CD44 knockdown in the BCSC population was achieved using small hairpin RNA lentivirus particles. The differentiated status of CD44 knock-down BCSCs was evaluated on the basis of changes in CD44<sup>+</sup>CD24<sup>- </sup>phenotype, tumorigenesis in NOD/SCID mice, and gene expression in relation to renewal status, metastasis, and cell cycle in comparison with BCSCs and non-BCSCs.</p> <p>Results</p> <p>Knockdown of CD44 caused BCSCs to differentiate into non-BCSCs with lower tumorigenic potential, and altered the cell cycle and expression profiles of some stem cell-related genes, making them more similar to those seen in non-BCSCs.</p> <p>Conclusions</p> <p>Knockdown of CD44 is an effective strategy for attacking the stemness of BCSCs, resulting in a loss of stemness and an increase in susceptibility to chemotherapy or radiation. The results of this study highlight a potential new strategy for breast cancer treatment through the targeting of BCSCs.</p

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

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    <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

    A modified Sequential Organ Failure Assessment score for dengue: development, evaluation and proposal for use in clinical trials

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    Background Dengue is a neglected tropical disease, for which no therapeutic agents have shown clinical efficacy to date. Clinical trials have used strikingly variable clinical endpoints, which hampers reproducibility and comparability of findings. We investigated a delta modified Sequential Organ Failure Assessment (delta mSOFA) score as a uniform composite clinical endpoint for use in clinical trials investigating therapeutics for moderate and severe dengue. Methods We developed a modified SOFA score for dengue, measured and evaluated its performance at baseline and 48 h after enrolment in a prospective observational cohort of 124 adults admitted to a tertiary referral hospital in Vietnam with dengue shock. The modified SOFA score included pulse pressure in the cardiovascular component. Binary logistic regression, cox proportional hazard and linear regression models were used to estimate association between mSOFA, delta mSOFA and clinical outcomes. Results The analysis included 124 adults with dengue shock. 29 (23.4%) patients required ICU admission for organ support or due to persistent haemodynamic instability: 9/124 (7.3%) required mechanical ventilation, 8/124 (6.5%) required vasopressors, 6/124 (4.8%) required haemofiltration and 5/124 (4.0%) patients died. In univariate analyses, higher baseline and delta (48 h) mSOFA score for dengue were associated with admission to ICU, requirement for organ support and mortality, duration of ICU and hospital admission and IV fluid use. Conclusions The baseline and delta mSOFA scores for dengue performed well to discriminate patients with dengue shock by clinical outcomes, including duration of ICU and hospital admission, requirement for organ support and death. We plan to use delta mSOFA as the primary endpoint in an upcoming host-directed therapeutic trial and investigate the performance of this score in other phenotypes of severe dengue in adults and children
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