22 research outputs found

    The Light-to-heat Conversion of Gold Nanoshells and Nanorods in Tissues

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    We perform a set of experiments on photo-heating in tissues containing gold nanoshells (NSs) and nanorods (NRs). The temperature of tissues were measured with different amounts gold NSs and NRs under illumination of a continuous diode laser at 808 nm and power density from 20 to 62 W/cm2^{2}. The temperature of the tissues injected gold nanoparticles increased to $66 \pm  4∘^{\circ}C for 2.1×1082.1 \times 10^{8} NSs and  73± 473\pm  4 ∘^{\circ}C for gold 5.4×1095.4 \times 10^{9} NRs after 10 min exposition at power density 35 W/cm2^{2}. The control tissue without gold nanoparticles demonstrated a significantly lower temperature 40± 440 \pm  4 ∘^{\circ}C in the same time of illumination. The temperature can be reached up to around 100∘^{\circ}C for tissue with both NSs and NRs at 62 W/cm2^{2} inrradiation for 7−107-10 min

    Two new species of Dixonius from Vietnam and Laos with a discussion of the taxonomy of Dixonius (Squamata, Gekkonidae)

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    Integrated analyses using maximum likelihood (ML), Bayesian inference (BI), principal component analysis (PCA), discriminate analysis of principal components (DAPC), multiple factor analysis (MFA), and analysis of variance (ANOVA) recovered two new diagnosable species of gekkonid lizards in the genus Dixonius, one from the Central Highlands, Gia Lai Province, Vietnam and another from the Vientiane Province, Laos. Phylogenetic analyses based on the mitochondrial NADH dehydrogenase subunit 2 gene (ND2) and adjacent tRNAs showed that Dixonius gialaiensis sp. nov. is the sister species of D. minhlei from Dong Nai Province, Vietnam and is nested within a clade that also includes the sister species D. siamensis and D. somchanhae. Dixonius muangfuangensis sp. nov. is the sister species to D. lao from Khammouane Province, Laos and is embedded in a clade with D. vietnamensis, D. taoi, and undescribed species from Thailand. Multivariate (PCA, DAPC, and MFA) and univariate (ANOVA) analyses using combinations of 15 meristic (scale counts), six morphometric (measurements), and five categorical (color pattern and morphology) characters from 44 specimens encompassing all eight species of Dixonius from Vietnam and Laos clearly illustrate Dixonius gialaiensis sp. nov. and Dixonius muangfuangensis sp. nov. are statistically different and discretely diagnosable from all closely related species of Dixonius. These integrative analyses also highlight additional taxonomic issues that remain unresolved within Dixonius and the need for additional studies. The discovery of these new species further emphasizes the underappreciated herpetological diversity of the genus Dixonius and illustrates the continued need for field work in these regions

    CSA: Thực hành nông nghiệp thông minh với khí hậu ở Việt Nam

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    During the last five years, Vietnam has been one of the countries most affected by climate change. Severe typhoons, flooding, cold spells, salinity intrusion, and drought have affected agriculture production across the country, from upland to lowland regions. Fortunately for Vietnam, continuous work in developing climate-smart agriculture has been occurring in research organizations and among innovative farmers and entrepreneurs. Application of various CSA practices and technologies to adapt to the impact of climate change in agriculture production have been expanding. However, there is a need to accelerate the scaling process of these practices and technologies in order to ensure growth of agriculture production and food security, increase income of farmers, make farming climate resilient, and contribute to global climate change mitigation. This book aims to provide basic information to researchers, managers, and technicians and extentionists at different levels on what CSA practices and technologies can be up scaled in different locations in Vietnam

    Determinants of catastrophic costs among households affected by multi-drug resistant tuberculosis in Ho Chi Minh City, Viet Nam: a prospective cohort study

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    Background: Globally, most people with multidrug-resistant tuberculosis (MDR-TB) and their households experience catastrophic costs of illness, diagnosis, and care. However, the factors associated with experiencing catastrophic costs are poorly understood. This study aimed to identify risk factors associated with catastrophic costs incurrence among MDR-TB-affected households in Ho Chi Minh City (HCMC), Viet Nam. Methods: Between October 2020 and April 2022, data were collected using a locally-adapted, longitudinal WHO TB Patient Cost Survey in ten districts of HCMC. Ninety-four people with MDR-TB being treated with a nine-month TB regimen were surveyed at three time points: after two weeks of treatment initiation, completion of the intensive phase and the end of the treatment (approximately five and 10 months post-treatment initiation respectively). The catastrophic costs threshold was defined as total TB-related costs exceeding 20% of annual pre-TB household income. Logistic regression was used to identify variables associated with experiencing catastrophic costs. A sensitivity analysis examined the prevalence of catastrophic costs using alternative thresholds and cost estimation approaches. Results: Most participants (81/93 [87%]) experienced catastrophic costs despite the majority 86/93 (93%) receiving economic support through existing social protection schemes. Among participant households experiencing and not experiencing catastrophic costs, median household income was similar before MDR-TB treatment. However, by the end of MDR-TB treatment, median household income was lower (258 [IQR: 0–516] USD vs. 656 [IQR: 462–989] USD; p = 0.003), and median income loss was higher (2838 [IQR: 1548–5418] USD vs. 301 [IQR: 0–824] USD; p < 0.001) amongst the participant households who experienced catastrophic costs. Being the household’s primary income earner before MDR-TB treatment (aOR = 11.2 [95% CI: 1.6–80.5]), having a lower educational level (aOR = 22.3 [95% CI: 1.5–344.1]) and becoming unemployed at the beginning of MDR-TB treatment (aOR = 35.6 [95% CI: 2.7–470.3]) were associated with experiencing catastrophic costs. Conclusion: Despite good social protection coverage, most people with MDR-TB in HCMC experienced catastrophic costs. Incurrence of catastrophic costs was independently associated with being the household’s primary income earner or being unemployed. Revision and expansion of strategies to mitigate TB-related catastrophic costs, in particular avoiding unemployment and income loss, are urgently required

    Anal human papillomavirus prevalence and risk factors among men who have sex with men in Vietnam.

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    OBJECTIVES: Men who have sex with men (MSM) are at risk of human papillomavirus (HPV)-related cancers, while published data are scarce. This study determined HPV prevalence and risk factors in MSM in Vietnam to inform HPV prevention strategies in this key population. METHODS: A cross-sectional study of 799 MSM aged 16-50 years was conducted in Vietnam in 2017-2018. Information was collected on risk behaviours, and knowledge of HPV and anal cancer; rectal swabs were taken to detect anal HPV infection. An in-house polymerase chain reaction and Genoflow HPV array test kit were used for HPV detection and genotyping. RESULTS: The median age of the study participants was 25 years (range 18-52). Overall prevalence of any HPV and HPV16/18 infection was 32.3% and 11.0%, respectively. A higher prevalence of high-risk HPV infection to all 14 types tested was found in Ho Chi Minh City (30.9%) than in Hanoi (18.4%). High-risk HPV infection was associated with inconsistent condom use and history of engaging in sex under the influence of drugs (adjusted odds ratio (aOR), 2.27; 95% CI, 1.48-10.67), as well as having multiple sexual partners (aOR, 1.01; 95% CI, 1.00-1.02). CONCLUSIONS: High-risk anal HPV infections in Vietnamese MSM were significantly associated with risky sexual behaviours. A targeted HPV vaccination strategy would have substantial benefit for MSM in Vietnam

    A hidden HIV epidemic among women in Vietnam

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    <p>Abstract</p> <p>Background</p> <p>The HIV epidemic in Vietnam is still concentrated among high risk populations, including IDU and FSW. The response of the government has focused on the recognized high risk populations, mainly young male drug users. This concentration on one high risk population may leave other populations under-protected or unprepared for the risk and the consequences of HIV infection. In particular, attention to women's risks of exposure and needs for care may not receive sufficient attention as long as the perception persists that the epidemic is predominantly among young males. Without more knowledge of the epidemic among women, policy makers and planners cannot ensure that programs will also serve women's needs.</p> <p>Methods</p> <p>More than 300 documents appearing in the period 1990 to 2005 were gathered and reviewed to build an understanding of HIV infection and related risk behaviors among women and of the changes over time that may suggest needed policy changes.</p> <p>Results</p> <p>It appears that the risk of HIV transmission among women in Vietnam has been underestimated; the reported data may represent as little as 16% of the real number. Although modeling predicted that there would be 98,500 cases of HIV-infected women in 2005, only 15,633 were accounted for in reports from the health system. That could mean that in 2005, up to 83,000 women infected with HIV have not been detected by the health care system, for a number of possible reasons. For both detection and prevention, these women can be divided into sub-groups with different risk characteristics. They can be infected by sharing needles and syringes with IDU partners, or by having unsafe sex with clients, husbands or lovers. However, most new infections among women can be traced to sexual relations with young male injecting drug users engaged in extramarital sex. Each of these groups may need different interventions to increase the detection rate and thus ensure that the women receive the care they need.</p> <p>Conclusion</p> <p>Women in Vietnam are increasingly at risk of HIV transmission but that risk is under-reported and under-recognized. The reasons are that women are not getting tested, are not aware of risks, do not protect themselves and are not being protected by men. Based on this information, policy-makers and planners can develop better prevention and care programs that not only address women's needs but also reduce further spread of the infection among the general population.</p

    Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

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    Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

    FLASH-TB: an Application of Next-Generation CRISPR to Detect Drug Resistant Tuberculosis from Direct Sputum

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    Offering patients with tuberculosis (TB) an optimal and timely treatment regimen depends on the rapid detection of Mycobacterium tuberculosis (Mtb) drug resistance from clinical samples. Finding Low Abundance Sequences by Hybridization (FLASH) is a technique that harnesses the efficiency, specificity, and flexibility of the Cas9 enzyme to enrich targeted sequences. Here, we used FLASH to amplify 52 candidate genes probably associated with resistance to first- and second-line drugs in the Mtb reference strain (H37Rv), then detect drug resistance mutations in cultured Mtb isolates, and in sputum samples. 92% of H37Rv reads mapped to Mtb targets, with 97.8% of target regions covered at a depth ≥ 10X. Among cultured isolates, FLASH-TB detected the same 17 drug resistance mutations as whole genome sequencing (WGS) did, but with much greater depth. Among the 16 sputum samples, FLASH-TB increased recovery of Mtb DNA compared with WGS (from 1.4% [IQR 0.5-7.5] to 33% [IQR 4.6-66.3]) and average depth reads of targets (from 6.3 [IQR 3.8-10.5] to 1991 [IQR 254.4-3623.7]). FLASH-TB identified Mtb complex in all 16 samples based on IS1081 and IS6110 copies. Drug resistance predictions for 15/16 (93.7%) clinical samples were highly concordant with phenotypic DST for isoniazid, rifampicin, amikacin, and kanamycin [15/15 (100%)], ethambutol [12/15 (80%)] and moxifloxacin [14/15 (93.3%)]. These results highlighted the potential of FLASH-TB for detecting Mtb drug resistance from sputum samples

    Improvement of Thermal and Mechanical Properties of Vietnam Deproteinized Natural Rubber via Graft Copolymerization with Methyl Methacrylate

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    In this study, we investigated the improvement of the thermal and mechanical properties of Vietnam deproteinized natural rubber (DPNR) via graft copolymerization of methyl methacrylate (MMA). The graft copolymerization was achieved successfully in latex stage using tert-butyl hydroperoxide (TBHPO) and tetra-ethylenepentamine (TEPA) as radical initiators at 30°C. By grafting with various MMA feeds and initiator concentration of 6.6×10−5 mol/g-rubber, the highest grafting efficiency and conversion were achieved at MMA of 15 wt.% per kg of rubber, 68% and 90%, respectively. The structure of grafted copolymers was characterized by 1H NMR, FTIR-ATR, and GPC, and thermal properties were investigated through DSC and TGA measurements. These showed that graft copolymers were more stable and rigid than DPNR. Storage modulus (G′) of graft copolymer was found to double that of DPNR, which contributed to the formation of graft copolymer. After sulfur vulcanization, the mechanical properties of DPNR-graft-PMMA, such as tensile strength, tear strength, and hardness, were improved significantly. Curing behaviors of the graft copolymers were found to be remarkably better than virgin DPNR
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