A new species of the paper wasp genus Ropalidia Guérin-Méneville, plebeja group (Hymenoptera, Vespidae, Polistinae), from Vietnam

A new species, Ropalidia daklak Bui, Mai & Nguyen, sp. nov., belonging to the plebeja-group of the genus Ropalidia Guérin-Méneville, 1831 is described and figured based on females and males from Vietnam. The nest structure of the new species is described, and an updated key is provided to all known species of the group

The impact of brand positioning and knowledge on attitude towards brand and purchase intention: A study of organic rice in Ho Chi Minh City

The purpose of this study is to measure the effectiveness of factors of brand, including Brand Positioning, Brand Knowledge, Attitude towards Organic Rice Brand, and Organic Rice Purchase Intention. The survey was conducted with a sample of 224 consumers shopping at four organic rice shops in Ho Chi Minh City. The research was performed by quantitative research methods: Cronbach's Alpha Reliability Analysis, Exploratory Factor Analysis (EFA), Confirm Factor Analysis (CFA), and Structural Equation Modeling (SEM). The research results were conducted in two direct models and the indirect models in which the indirect model was supported. This means that brand positioning and brand knowledge had no direct impact on the Intention to buy organic rice, but only an indirect one through the consumer attitude towards the organic rice brand

Biocompatible chitosan-functionalized upconverting nanocomposites

Simultaneous integration of photon emission and biocompatibility into nanoparticles is an interesting strategy to develop applications of advanced optical materials. In this work, we present the synthesis of biocompatible optical nanocomposites from the combination of near-infrared luminescent lanthanide nanoparticles and water-soluble chitosan. NaYF4:Yb,Er upconverting nanocrystal guests and water-soluble chitosan hosts are prepared and integrated together into biofunctional optical composites. The control of aqueous dissolution, gelation, assembly, and drying of NaYF4:Yb,Er nanocolloids and chitosan liquids allowed us to design novel optical structures of spongelike aerogels and beadlike microspheres. Well-defined shape and near-infrared response lead upconverting nanocrystals to serve as photon converters to couple with plasmonic gold (Au) nanoparticles. Biocompatible chitosan-stabilized Au/NaYF4:Yb,Er nanocomposites are prepared to show their potential use in biomedicine as we find them exhibiting a half-maximal effective concentration (EC50) of 0.58 mg mL–1 for chitosan-stabilized Au/NaYF4:Yb,Er nanorods versus 0.24 mg mL–1 for chitosan-stabilized NaYF4:Yb,Er after 24 h. As a result of their low cytotoxicity and upconverting response, these novel materials hold promise to be interesting for biomedicine, analytical sensing, and other applications

Design and fabrication of effective gradient temperature sensor array based on bilayer SnO2/Pt for gas classification

Classification of different gases is important, and it is possible to use different gas sensors for this purpose. Electronic noses, for example, combine separated gas sensors into an array for detecting different gases. However, the use of separated sensors in an array suffers from being bulky, high-energy consumption and complex fabrication processes. Generally, gas sensing properties, including gas selectivity, of semiconductor gas sensors are strongly dependent on their working temperature. It is therefore feasible to use a single device composed of identical sensors arranged in a temperature gradient for classification of multiple gases. Herein, we introduce a design for simple fabrication of gas sensor array based on bilayer Pt/SnO2 for real-time monitoring and classification of multiple gases. The study includes design simulation of the sensor array to find an effective gradient temperature, fabrication of the sensors and test of their performance. The array, composed of five sensors, was fabricated on a glass substrate without the need of backside etching to reduce heat loss. A SnO2 thin film sensitized with Pt on top deposited by sputtering was used as sensing material. The sensor array was tested against different gases including ethanol, methanol, isopropanol, acetone, ammonia, and hydrogen. Radar plots and principal component analysis were used to visualize the distinction of the tested gases and to enable effective classification

Streptococcus suis, an Important Cause of Adult Bacterial Meningitis in Northern Vietnam

Streptococcus suis can cause severe systemic infection in adults exposed to infected pigs or after consumption of undercooked pig products. S. suis is often misdiagnosed, due to lack of awareness and improper testing. Here we report the first fifty cases diagnosed with S. suis infection in northern Viet Nam.In 2007, diagnostics for S. suis were set up at a national hospital in Hanoi. That year there were 43 S. suis positive cerebrospinal fluid samples, of which S. suis could be cultured in 32 cases and 11 cases were only positive by PCR. Seven patients were blood culture positive for S. suis but CSF culture and PCR negative; making a total of 50 patients with laboratory confirmed S. suis infection in 2007. The number of S. suis cases peaked during the warmer months.S. suis was commonly diagnosed as a cause of bacterial meningitis in adults in northern Viet Nam. In countries where there is intense and widespread exposure of humans to pigs, S. suis can be an important human pathogen

Farming systems in the sandy area of the Thua Thien Hue Province, Central Vietnam, survey of socio-economic situation and constraints identified by farmers

peer reviewe

Состояние провоспалительного цитокинового звена у больных с нестабильной стенокарадией и сахарным диабетом 2-го типа в зависимости от функционального класса хронической сердечной недостаточности

Проанализировано состояние провоспалительного звена цитокинов у больных с нестабильной стенокардией (НС) и сопутствующим сахарным диабетом (СД) 2−го типа в зависимости от функционального класса хронической сердечной недостаточности (ХСН). Нарастание проявлений сердечной декомпенсации у больных с НС и СД 2−го типа ассоциируется с высокой активностью провоспалительного цитокинового звена, представленного фактором некроза опухолей−α и интерлейкином−6. Повышение функционального класса ХСН характеризуется увеличением инсулинорезистентности у больных с НС и СД 2−го типа.Проаналізовано стан прозапальної ланки цитокінів у хворих із нестабільною стенокардією (НС) та супутнім цукровим діабетом (ЦД) 2−го типу залежно від функціонального класу хронічної серцевої недостатності (ХСН). Наростання проявів серцевої декомпенсації у хворих із НС та СД 2−го типу асоціюється з високою активністю прозапальної цитокінової ланки, представленої фактором некрозу пухлин−α та інтерлейкіном−6. Підвищення функціонального класу ХСН характеризується зростанням інсулінорезистентності у хворих із НС та ЦД 2−го типу.The state of pro−inflammatory cytokines in patients with unstable angina (UA) and associated type 2 diabetes mellitus (DM) was analyzed depending on the functional class of chronic heart failure (CHF). The increase in manifestations of cardiac decompensation in patients with UA and type 2 DM is associated with high activity of pro−inflammatory cytokine level represented by tumor necrosis factor−β and interleukin−6. Increase of functional class of CHF is characterized by increased insulin resistance in patients with UA and type 2 DM

Limited contribution of non-intensive chicken farming to ESBL-producing Escherichia coli colonization in humans in Vietnam: an epidemiological and genomic analysis.

OBJECTIVES: To investigate the risk of colonization with ESBL-producing Escherichia coli (ESBL-Ec) in humans in Vietnam associated with non-intensive chicken farming. METHODS: Faecal samples from 204 randomly selected farmers and their chickens, and from 306 age- and sex-matched community-based individuals who did not raise poultry were collected. Antimicrobial usage in chickens and humans was assessed by medicine cabinet surveys. WGS was employed to obtain a high-resolution genomic comparison between ESBL-Ec isolated from humans and chickens. RESULTS: The adjusted prevalence of ESBL-Ec colonization was 20.0% (95% CI 10.8%-29.1%) and 35.2% (95% CI 30.4%-40.1%) in chicken farms and humans in Vietnam, respectively. Colonization with ESBL-Ec in humans was associated with antimicrobial usage (OR = 2.52, 95% CI = 1.08-5.87) but not with involvement in chicken farming. blaCTX-M-55 was the most common ESBL-encoding gene in strains isolated from chickens (74.4%) compared with blaCTX-M-27 in human strains (47.0%). In 3 of 204 (1.5%) of the farms, identical ESBL genes were detected in ESBL-Ec isolated from farmers and their chickens. Genomic similarity indicating recent sharing of ESBL-Ec between chickens and farmers was found in only one of these farms. CONCLUSIONS: The integration of epidemiological and genomic data in this study has demonstrated a limited contribution of non-intensive chicken farming to ESBL-Ec colonization in humans in Vietnam and further emphasizes the importance of reducing antimicrobial usage in both human and animal host reservoirs