Multiple Wolbachia strains provide comparative levels of protection against dengue virus infection in Aedes aegypti.

The insect bacterium Wolbachia pipientis is being introgressed into Aedes aegypti populations as an intervention against the transmission of medically important arboviruses. Here we compare Ae. aegypti mosquitoes infected with wMelCS or wAlbB to the widely used wMel Wolbachia strain on an Australian nuclear genetic background for their susceptibility to infection by dengue virus (DENV) genotypes spanning all four serotypes. All Wolbachia-infected mosquitoes were more resistant to intrathoracic DENV challenge than their wildtype counterparts. Blocking of DENV replication was greatest by wMelCS. Conversely, wAlbB-infected mosquitoes were more susceptible to whole body infection than wMel and wMelCS. We extended these findings via mosquito oral feeding experiments, using viremic blood from 36 acute, hospitalised dengue cases in Vietnam, additionally including wMel and wildtype mosquitoes on a Vietnamese nuclear genetic background. As above, wAlbB was less effective at blocking DENV replication in the abdomen compared to wMel and wMelCS. The transmission potential of all Wolbachia-infected mosquito lines (measured by the presence/absence of infectious DENV in mosquito saliva) after 14 days, was significantly reduced compared to their wildtype counterparts, and lowest for wMelCS and wAlbB. These data support the use of wAlbB and wMelCS strains for introgression field trials and the biocontrol of DENV transmission. Furthermore, despite observing significant differences in transmission potential between wildtype mosquitoes from Australia and Vietnam, no difference was observed between wMel-infected mosquitoes from each background suggesting that Wolbachia may override any underlying variation in DENV transmission potential

Antibacterial hydrogel containing Piper betle L. extract for acne treatment, an ex vivo investigation

The current treatments of acne vulgaris and acne-like disorders such as gram-negative folliculitis possess lots of unwanted side effects. Thus, alternative approach of utilizing natural plant extracts, specifically Piper betle L., have gained much attention. To this end, this work developed, characterized, and ex vivo evaluated novel antibiotics hydrogels containing P. betle L. leaf extract for acne treatment. Firstly, the design of experiments (DoE) D-optimal method was successfully developed, optimized, and validated, to investigate the relationship between P. betle L. extraction conditions and the extract properties. Secondly, the best extract was encapsulated in the hydrogel formulations composed of carbopol 940, propylene glycol, and cocamidopropyl betaine. Finally, the hydrogel was ex vivo determined its antibacterial activity on bacteria isolated from 15 patient acne samples. The optimal extraction condition being an extraction solvent/plant weight ratio of 4.034:1, an extraction time of 2.147 h, and a water extract volume of 91.4 mL. This condition yielded an extract total phenolic content of 3.337±0.034 g GAE/g, and minimum inhibitory concentrations of 32 µg/mL and 128 µg/mL on Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922, respectively. The hydrogel possessed suitable properties for a topical medication, including a viscosity of 6800 cps, a pH of 7.0, and a good foaming ability, at both 10°C, 25°C, and 40°C. The hydrogel showed higher antibacterial activity than the positive controls in both gram-positive and gram-negative bacteria. Conclusively, the hydrogel could become a potential pharmaceutical product for acne treatment

Visual and biochemical evidence of glycocalyx disruption in human dengue infection, and association with plasma leakage severity

Background: Dengue is the most common arboviral infection globally; a minority of patients develop shock due to profound plasma leak through a disrupted endothelial barrier. Understanding of the pathophysiology underlying plasma leak is incomplete, but emerging evidence indicates a key role for degradation of the endothelial glycocalyx. Methods: We conducted an observational study in Vietnam to evaluate the sublingual microcirculation using sidestream darkfield imaging in (1) outpatients with confirmed dengue (2) patients hospitalized with dengue and (3) outpatients with other febrile illness (OFI). We estimated the glycocalyx degradation by measuring the perfused boundary region (PBR hf) and an overall microvascular health score (MVHS) with the software application GlycoCheckTM at enrolment, 48 h later and hospital discharge/defervescence. We measured plasma syndecan1 and endocan at the same time-points. We compared PBR hf, MVHS, syndecan1 and endocan, between (1) outpatients with confirmed dengue vs. OFI and (2) patients with dengue subdivided by clinical severity of plasma leak. Results: We included 75 patients with dengue (41 outpatients, 15 inpatients, 19 in intensive care) and 12 outpatients with OFI. Images from 45 patients were analyzed using GlycoCheckTM. There was no significant difference in PBR hf or MVHS between outpatients with dengue and OFI. Median plasma syndecan1 was not significantly different in outpatients with dengue vs. OFI, while median plasma endocan was significantly lower among patients with dengue vs. OFI during the critical phase. In patients with dengue, PBR hf was higher in patients with Grade 2 vs. Grade 0 plasma leakage during the critical phase (PBR hf 1.96 vs. 1.36 μm for Grade 2 vs. Grade 0 plasma leakage on days 4–6, respectively, p < 0.001). Median levels of plasma syndecan1 and endocan were higher in Grade 2 vs. Grade 0 plasma leakage, especially during the critical phase (Syndecan1 2,613.8 vs. 125.9 ng/ml for Grade 2 vs. Grade 0 plasma leakage on days 4–6, respectively, p < 0.001, and endocan 3.21 vs. 0.16 ng/ml for Grade 2 vs. Grade 0 plasma leakage on days 4–6, respectively). Conclusions: We present the first human in vivo evidence of glycocalyx disruption in dengue, with worse visual glycocalyx damage and higher plasma degradation products associated with more severe plasma leak

THỰC VẬT PHÙ DU VÙNG BIỂN VEN BỜ ĐÀ NẴNG

Phytoplankton, especially community characteristics, in coastal waters of Da Nang have not been well studied. This present study analyzed data of phytoplankton for diversity and abundance from surveys from 2002 to 2016 at 44 stations in the coastal Da Nang waters. A total of 316 taxa from 9 classes were identified: Dinophyceae (134 taxa), Mediophyceae (77 taxa), Coscinodiscophyceae (44 taxa), Bacillariophyceae (36 taxa), Cyanophyceae (3 taxa), Dictyochophyceae (2 taxa), Bacillariophyta classis incertae sedis (1 taxon), Conjugatophyceae (1 taxon) and Thecofilosea (1 taxon). A list of 36 species of potentially harmful microalgae was recorded in coastal waters of Da Nang. In which, Pseudo-nitzschia spp. often had higher cell densities in some locations during the northeast monsoon. Analyzing diversity indices in different locations showed that there were significance differences of Margalef and Shannon indices, low in estuarine area (CS) and higher in the south of Son Tra peninsula (NST). Meanwhile no strong differences of Pielou and Simpson indices were found among the locations. However, there were strong differences of Margalef, Simpson and Pielou indices, which were found over the three studied years (2004, 2005, and 2006), mainly in NST, the northeast of Son Tra peninsula (DBST) and Da Nang bay (VDN). Analysis of species accumulation curves indicated that only 56–95% of species  was found compared to maximal expected species richness in all studied locations. DMS analysis showed that there was year-based similarity among the years (ca. 50% of similarity) of phytoplankton communities. Among the studied years, average phytoplankton cell densities in Da Nang bay and the northeast of Son Tra were higher than those in other years and locations. This present study on species richness, expected species richness and variation in phytoplankton abundance suggested that there is a need of increasing sampling efforts, especially in riverine area and DBST for better understanding of characteristics of phytoplankton communities in coastal Da Nang waters.Thực vật phù du là đối tượng ít được nghiên cứu ở vùng biển ven bờ Đà Nẵng, nhất là những đặc trưng về thành phần loài và cấu trúc quần xã. Trong bài báo này, chúng tôi phân tích số liệu về đa dạng loài và sự phong phú của thực vật phù du thu thập được trong các chuyến khảo sát từ năm 2002 đến năm 2016 ở 44 trạm trong vùng biển ven bờ Đà Nẵng. Kết quả phân tích đã xác định được 316 loài và dưới loài thuộc 9 lớp tảo khác nhau. Trong các loài thực vật phù du ghi nhận được, có 36 loài tảo có khả năng gây hại, trong đó mật độ của Pseudo-nitzschia spp. cao hơn tại một số khu vực trong thời kỳ gió mùa Đông Bắc. Phân tích các chỉ số theo từng khu vực, có thể thấy chỉ số giàu có loài Margalef và chỉ số đa dạng Shannon khác nhau đáng kể giữa các khu vực, thấp ở cửa sông trong vịnh Đà Nẵng và cao ở nam bán đảo Sơn Trà. Trong khi các chỉ số cân bằng Pielou và đa dạng Simpson lại không khác biệt giữa các khu vực. Tuy nhiên, sự đa dạng và độ giàu có loài lại có sự khác biệt giữa các năm 2004, 2005 và 2016, chủ yếu ở nam bán đảo Sơn Trà, đông bắc bán đảo Sơn Trà và vịnh Đà Nẵng. Phân tích độ giàu có loài cho thấy hầu hết các khu vực đều chỉ ghi nhận được từ 56% đến 95% số loài mong đợi. Phân tích cấu trúc quần xã thực vật phù du thu thể hiện sự biến động giữa các năm nghiên cứu với mức độ tương đồng trong năm xấp xỉ 50%. So sánh trung bình mật độ thực vật phù du thu của từng khu vực cho thấy mật độ vào năm 2005 cao hơn hẳn so với các năm khác ở vịnh Đà Nẵng và đông bắc Sơn Trà. Các phân tích về độ giàu có loài, loài mong đợi và biến động mật độ thực vật phù du thu cho thấy dù vùng biển nghiên cứu được ghi nhận thành phần loài thực vật phù du thu cao, nhưng số lượng trạm và thời gian thu mẫu ở vùng biển Đà nẵng nhất là khu vực cửa sông cần được thu thập nhiều hơn, vẫn cần thu thập thêm vật mẫu ở tất cả các khu vực, nhất là vùng cửa sông trong vịnh Đà Nẵng và đông bắc bán đảo Sơn Trà

Camellia sinensis extract delays microbiological and oxidative changes in striped catfish fillets during frozen storage

peer reviewedThis study investigated the effects of tea leaf (Camellia sinensis) extract on the quality of striped catfish (Pangasianodon hypophthalmus) fillets during 18-months of frozen storage (-20 ± 2 °C). Fillet samples were submitted to the treatments Control (cold tap water), CS 7.63 (C. sinensis extract solution 7.63 µg/mL) and CS 625 (C. sinensis extract 625 µg/mL) and stored for 18 months, with collections performed at 0, 1, 3, 6, 9, 12 and 18 months. Total viable count, physicochemical parameters (water holding capacity, total volatile basic nitrogen, peroxide value, thiobarbituric acid reactive substances, moisture and pH), sensory properties and color measurement were evaluated. Results showed that fillets treated with C.a sinensis extracts slightly reduced lipid oxidation, inhibited bacterial growth and improved sensory properties compared to untreated samples, without causing significant changes in the other quality indicators. The findings indicated that the green tea leaf extract immersion treatments, contributed to the improved quality preservation of striped catfish fillets during frozen storage

Genome evolution of dengue virus serotype 1 under selection by <i>Wolbachia pipientis</i> in <i>Aedes aegypti</i> mosquitoes.

The introgression of antiviral strains of Wolbachia into Aedes aegypti mosquito populations is a public health intervention for the control of dengue. Plausibly, dengue virus (DENV) could evolve to bypass the antiviral effects of Wolbachia and undermine this approach. Here, we established a serial-passage system to investigate the evolution of DENV in Ae. aegypti mosquitoes infected with the wMel strain of Wolbachia. Using this system, we report on virus genetic outcomes after twenty passages of serotype 1 of DENV (DENV-1). An amino acid substitution, E203K, in the DENV-1 envelope protein was more frequently detected in the consensus sequence of virus populations passaged in wMel-infected Ae. aegypti than wild-type counterparts. Positive selection at residue 203 was reproducible; it occurred in passaged virus populations from independent DENV-1-infected patients and also in a second, independent experimental system. In wild-type mosquitoes and human cells, the 203K variant was rapidly replaced by the progenitor sequence. These findings provide proof of concept that wMel-associated selection of virus populations can occur in experimental conditions. Field-based studies are needed to explore whether wMel imparts selective pressure on DENV evolution in locations where wMel is established

C-reactive protein as a potential biomarker for disease progression in dengue: a multi-country observational study.

BACKGROUND: Dengue infection can cause a wide spectrum of clinical outcomes. The severe clinical manifestations occur sufficiently late in the disease course, during day 4-6 of illness, to allow a window of opportunity for risk stratification. Markers of inflammation may be useful biomarkers. We investigated the value of C-reactive protein (CRP) measured early on illness days 1-3 to predict dengue disease outcome and the difference in CRP levels between dengue and other febrile illnesses (OFI). METHOD: We performed a nested case-control study using the clinical data and samples collected from the IDAMS-consortium multi-country study. This was a prospective multi-center observational study that enrolled almost 8000 participants presenting with a dengue-like illness to outpatient facilities in 8 countries across Asia and Latin America. Predefined severity definitions of severe and intermediate dengue were used as the primary outcomes. A total of 281 cases with severe/intermediate dengue were compared to 836 uncomplicated dengue patients as controls (ratio 1:3), and also 394 patients with OFI. RESULTS: In patients with confirmed dengue, median (interquartile range) of CRP level within the first 3 days was 30.2 mg/L (12.4-61.2 mg/L) (uncomplicated dengue, 28.6 (10.5-58.9); severe or intermediate dengue, 34.0 (17.4-71.8)). Higher CRP levels in the first 3 days of illness were associated with a higher risk of severe or intermediate outcome (OR 1.17, 95% CI 1.07-1.29), especially in children. Higher CRP levels, exceeding 30 mg/L, also associated with hospitalization (OR 1.37, 95% CI 1.14-1.64) and longer fever clearance time (HR 0.84, 95% CI 0.76-0.93), especially in adults. CRP levels in patients with dengue were higher than patients with potential viral infection but lower than patients with potential bacterial infection, resulting in a quadratic association between dengue diagnosis and CRP, with levels of approximately 30 mg/L associated with the highest risk of having dengue. CRP had a positive correlation with total white cell count and neutrophils and negative correlation with lymphocytes, but did not correlate with liver transaminases, albumin, or platelet nadir. CONCLUSIONS: In summary, CRP measured in the first 3 days of illness could be a useful biomarker for early dengue risk prediction and may assist differentiating dengue from other febrile illnesses

Choice modeling approach to evaluate the economic value of renewable energy development

Purpose. This research aims to quantify the willingness to pay (WTP) of urban residents in the Mekong Delta for the environmental and social benefits associated with renewable energy projects. By analysing their preferences and priorities regarding renewable energy implementation, this study aims to contribute to the increasing knowledge on the drivers of sustainable energy transitions in developing regions. Methodology / approach. This paper leverages a choice modeling (CM) framework to analyse the economic viability of renewable energy investments in Vietnam. The CM technique is advantageous for its ability to capture individual preferences for complex goods or services characterised by multiple attributes and trade-offs. This enables a detailed assessment of the diverse economic values associated with renewable energy sources, beyond their traditional energy generation capacity, including environmental externalities, social impacts, and potential synergies with other sectors. Results. Residents showed significant WTP for renewable energy initiatives improving landscape aesthetics, wildlife habitats, air quality, and job opportunities. Higher income, education, and knowledge level are positively associated with greater WTP. Younger respondents showed a strong position in favor of renewable energy sources. Households with more children were less likely to support the status quo, and married respondents were more pro-renewable. Perceived community involvement emerged as a significant factor in supporting renewable energy policies. Originality / scientific novelty. This study represents a novel application of CM within the Vietnamese context, providing valuable quantitative data for policymakers and stakeholders. By estimating WTP for specific renewable energy attributes, we inform cost-benefit assessments and support the development of efficient policies for managing renewable energy investments. This data facilitates resource allocation and prioritisation of projects with the highest societal value. Practical value / implications. Our findings underscore the crucial role of public awareness and education in driving renewable energy implementation. Residents with a clear understanding of the benefits demonstrate a higher WTP. Hence, we recommend a multifaceted communication strategy to educate the public about the environmental, social, and economic benefits of renewable energy. This involves utilising diverse channels like community meetings, media outreach, online platforms, and expert engagement to disseminate accurate and engaging information. By fostering knowledge and understanding, we can cultivate a strong public mandate for renewable energy investment, facilitating informed decision-making and accelerating the transition to a sustainable energy future in the Mekong Delta

Choice modeling approach to evaluate the economic value of renewable energy development

Purpose. This research aims to quantify the willingness to pay (WTP) of urban residents in the Mekong Delta for the environmental and social benefits associated with renewable energy projects. By analysing their preferences and priorities regarding renewable energy implementation, this study aims to contribute to the increasing knowledge on the drivers of sustainable energy transitions in developing regions. Methodology / approach. This paper leverages a choice modeling (CM) framework to analyse the economic viability of renewable energy investments in Vietnam. The CM technique is advantageous for its ability to capture individual preferences for complex goods or services characterised by multiple attributes and trade-offs. This enables a detailed assessment of the diverse economic values associated with renewable energy sources, beyond their traditional energy generation capacity, including environmental externalities, social impacts, and potential synergies with other sectors. Results. Residents showed significant WTP for renewable energy initiatives improving landscape aesthetics, wildlife habitats, air quality, and job opportunities. Higher income, education, and knowledge level are positively associated with greater WTP. Younger respondents showed a strong position in favor of renewable energy sources. Households with more children were less likely to support the status quo, and married respondents were more pro-renewable. Perceived community involvement emerged as a significant factor in supporting renewable energy policies. Originality / scientific novelty. This study represents a novel application of CM within the Vietnamese context, providing valuable quantitative data for policymakers and stakeholders. By estimating WTP for specific renewable energy attributes, we inform cost-benefit assessments and support the development of efficient policies for managing renewable energy investments. This data facilitates resource allocation and prioritisation of projects with the highest societal value. Practical value / implications. Our findings underscore the crucial role of public awareness and education in driving renewable energy implementation. Residents with a clear understanding of the benefits demonstrate a higher WTP. Hence, we recommend a multifaceted communication strategy to educate the public about the environmental, social, and economic benefits of renewable energy. This involves utilising diverse channels like community meetings, media outreach, online platforms, and expert engagement to disseminate accurate and engaging information. By fostering knowledge and understanding, we can cultivate a strong public mandate for renewable energy investment, facilitating informed decision-making and accelerating the transition to a sustainable energy future in the Mekong Delta

Preparation of Carbon-Supported Ternary Nanocatalysts Palladium-Vanadium-Cobalt for Alcohol Electrooxidation

Carbon-supported nanocatalysts palladium-vanadium-cobalt (PdVCo) were synthesized via ethylene glycol (EG) reduction reaction and NaBH4-assisted reduction. The electrocatalytic performance for alcohol oxidation in alkaline solutions was investigated. The XRD and EDX results confirmed the incorporation of V and Co with Pd lattice to form the ternary nanocatalysts PdVCo in a single phase. The NaBH4-assisted EG reduction process exhibited highly dispersed nanoparticles with a uniform size, and the electrochemical surface area (ECSA) determined by cyclic voltammetry in 1 M KOH was also superior. In electrocatalysis performance, the cyclic voltammetry (CV) and chronoamperometry (CA) results presented an excellent electrocatalytic activity and stability of the PdVCo-20EG-20NaBH4 sample in the alcohol electrooxidation as compared to other synthesized samples with the steady current of 52 mA/cm2 and 21.9 mA/cm2 in methanol and ethanol, respectively