The evaluation trial was conducted from August 2004 to March 2005 in the laboratory of the National Institute of Malariolgy, Parasitology and Entomology, Ha Noi. Bioassays with An.dirus and Ae.aegypti (reared mosquitoes) were made according to the WHO method for evaluation of susceptibility and residual effects of the insecticide on the painted and nylon wall surface. Ale lose sprayed at the dose of 30mg ai/m2 were found to produce residual effect for 6-7 months on the painted wall surfaces (mosquito mortalities: 51.1%-67.8%) and for 4-5 months on nylon wall surface (mosquito mortality: 55.6%-67.8%).
Malaria ; Pyrethrins ; Laboratories

Background: Acute gastroenterophathy usually caused by the Rota virus for children under 5 years old. Objectives: To present various types of data on epidemiology of ROTA virus diarrhea in Ho Chi Minh city from 12/2006-11/2007. Material and method: The data were collected from 500 stool specimens of diarrhea diagnosed chilren hosptalised at Thuy Dien Pediatric hospital 1, Ho Chi Minh city from December/2006 to November /2007. Results:There were 322 rotavirus-positive specimens, representing 64.4%. The proportions of monthly distribution of cases with diarrhea due to rotavirus were 90.1%, 54.39%, 85.37%, 74.51%, 72.92%, 41.67%, 26.67%, 58.33%, 79.31%, 52.63%, 69.05% and 57.78%, respectively. The numbers of rotavirus-positive cases in male and female were 216 (65.26%) and 106 (62.72%), respectively. The proportions of Rota virus positive children compared to total number of diarrheal cases with age 0-3, 3-6, 6-12, 12-24, 24-36 and over 36 months were 2.80%, 7.76%, 40.06%, 40.68%, 5.28% and 3.42%, respectively.\r\n', u'The results of typing identification indicated that the phenotypes of 98 among 100 specimens were identified (98%) in which there were sixty-one specimens of G1P8 (61%), one specimen of G2P8 (1%), fourteen specimens of G3P8 (14%), four of specimens of G4P8 (4%), eighteen specimens of GmixedP8 (18%). There were only two specimens of GnontypeableP8 (2%). Conclusion: Further studies should be carried out to clear this issue.\r\n', u'
Rotavirus ; gel type.

Background: Human albumin was produced and used in many countries. Cohn's technique had been used to precipitate albumin from human plasma. This technique was easy and cheap and the quality of the product was good. In Vietnam, human albumin had to import, but the prices was very expensive. Vietnam was having good plasma in large quantity and high quality. That\u2019s why research on production plasma albumin was essential.\r\n", u"Objectives: This study aimed at using Cohn's technique improved by Drohan and Van - Aken to produce standard albumin from human plasma. Subjects and method: Human plasma detected VIII-factor was used for present study. Plasma \ufffd?albumin was precipitated by ethanol at low temperature and pH. The collected albumins have been liophilizated and storage at 40C. The quality and quantity of Albumin was evaluated by quantitative analysis and protein \ufffd?electrophoresis. Results: The 418g of albumin powder was produced from 16 liters of plasma detected F \ufffd?VIII. The quality of this albumin come up to standard (>95%) and quantity of albumin collected from one liter of this plasma was 26g. Conclusion: In the Vietnamese condition, the technique of Cohn can be used to produce standard albumin for treatment.\r\n", u'
Albumins/ standards ; Plasma ;

Objectives: Vibrio parahaemolyticus is a major foodborne pathogen in aquatic animals and a threat to human health worldwide. This study investigated the prevalence, antimicrobial resistance, antimicrobial resistance genes (ARGs), and biofilm formation of V. parahaemolyticus strains isolated from fish mariculture environments in Cat Ba Island, Vietnam. Methods: In total, 150 rearing water samples were collected from 10 fish mariculture farms in winter and summer. A polymerase chain reaction assay was used to identify V. parahaemolyticus, its virulence factors, and ARGs. The antimicrobial resistance patterns and biofilm formation ability of V. parahaemolyticus strains were investigated using the disk diffusion test and a microtiter plate-based crystal violet method, respectively. Results: Thirty-seven V. parahaemolyticus isolates were recovered from 150 samples. The frequencies of the tdh and trh genes among V. parahaemolyticus isolates were 8.1% and 21.6%, respectively. More than 90% of isolates were susceptible to ceftazidime, cefotaxime, and chloramphenicol, but over 72% were resistant to ampicillin, tetracycline, and erythromycin. Furthermore, 67.57% of isolates exhibited multidrug resistance. The presence of ARGs related to gentamicin (aac(3)-IV), tetracycline (tetA) and ciprofloxacin (qnrA) in V. parahaemolyticus isolates was identified. Conversely, no ARGs related to ampicillin or erythromycin resistance were detected. Biofilm formation capacity was detected in significantly more multidrug-resistant isolates (64.9%) than non-multidrug-resistant isolates (18.9%). Conclusion Mariculture environments are a potential source of antibiotic-resistant V.parahaemolyticus and a hotspot for virulence genes and ARGs diffusing to aquatic environments. Thus, the prevention of antibiotic-resistant foodborne vibriosis in aquatic animals and humans requires continuous monitoring.

Ultrasonic computed tomography based on back scattering theory is the most powerful and accurate tool in ultrasound based imaging approaches because it is capable of providing quantitative information about the imaged target and detects very small targets. The duple-frequency distorted Born iterative method (DF–DBIM), which uses density information along with sound contrast for imaging, is a promising approach for imaging targets at the level of biological tissues. With two frequencies f₁ (low) and f₂ (high) through Nf₁ and Nf₂ iterations respectively, this method is used to estimate target density along with sound contrast. The implications of duple-frequency fusion for the image reconstruction quality of density information along with sound contrast based ultrasound tomography have been analyzed in this paper. In this paper, we concentrate on the selection of parameters that is supposed to be the best to improve the reconstruction quality of ultrasound tomography. When there are restraints imposed on simulated scenarios to have control of the computational cost, the iteration number Nf₁ is determined resulting in giving the best performance. The DF–DBIM is only effective if there are a moderate number of iterations, transmitters and receivers. In case that the number of transducers is either too large or too small, a result of reconstruction which is better than that of the single frequency approach is not produced by the implementation of DF–DBIM. A fixed sum N(iter) of Nf₁ and Nf₂ was given, the investigation of simulation results shows that the best value of Nf₁ is [N(iter)/2 − 1]. The error, when applying this way of choosing the parameters, will be normalized with the reduction of 56.11%, compared to use single frequency as used in the conventional DBIM method. The target density along with sound contrast is used to image targets in this paper. It is a fact that low-frequency offers fine convergence, and high-frequency offers fine spatial resolution. Wherefore, this technique can effectively expand DBIM's applicability to the problem of biological tissue reconstruction. Thanks to the usage of empirical data, this work will be further developed prior to its application in reality.
Image Processing, Computer-Assisted ; Methods ; Transducers ; Ultrasonics ; Ultrasonography

Teachers’ perspectives on teaching, learning, and education are their beliefs, attitudes, and understandings. This study examines Vietnamese teachers’ perspectives on constructivist theory, a “revolution in current educational psychology”. Because it has greatly influenced teaching and education philosophy and practice worldwide, notably general education program reform. This study uses constructivist theory to build techniques and forms for Vietnamese primary teachers through experiential activities. The north Vietnam: Hanoi Capital, Vinh Phuc City, Ninh Binh City, Cao Bang City, Lao Cai City, Bac Giang City. The average tenure of teachers is nearly 11 years. The authors used a teacher’s questionnaire from six provinces to collect data on constructing experiential activities in a constructivist primary school subject. The findings showed that primary teachers preferred experiential activities in the subject based on constructivist theory and that story-telling and conversation were the most popular teaching methods and instructional forms. Constructivist theory stresses that learners actively construct knowledge and understand via experience. Teachers that use constructivist theory to build primary school experiences will help kids at this foundational level acquire quality and capacity.

Introduction: The need for gama \u2013 globulin, especially gama - globulin - anti \u2013 HBs, is huge in Vietnam. A number of patients cannot to afford use them due to the high price as they are imported. Meanwhile, Vietnam has high quality input sources for producing gama \u2013 globulin. \r\n', u'Objectives: To study the production process of gama - Globulin from Human Plasma and Standard gama - Globulin with Rich of Anti \u2013 HBs. \r\n', u'Subjects and method: 168 samples of human plasma from voluntary blood donors, which had been screened with for transfusion transmittable infections (TTLs), were chosen as plasma with rich of anti - HBs. The plasma with anti - HBsAg was precipitated with ethanol 25%, pH 6,9 to gain gama - globulin with rich anti - HBs, which was dried by Dutch Ly - 3 - TTE machine. Activation of anti - HBs gama - globulin was identified by a standard method of the degree of antibody specific for anti - HBsAg kit of BIORAD, \r\n', u'Results: The purity of the gama - globulin achieved was 93%, which was almost equal with the results of some foreign researchers (7.8), the activation of anti - HBs was 1:128 dilution degree. The productivity of gama - globulin gaining from 1 litter plasma was 6.0 gram. This new issue was first demonstrated in Vietnam. \r\n', u'Conclusion: We can domestically produce anti-Bs gama - globulin with high degree of activeness (1:128) from human plasma by the precipitating method with ethanol, pH and low temperature. \r\n', u'
Human plasma ; gama - globulin - anti - HBs ; Precipitation of ethanol ; pH and low temperature

Objective: The purpose of this survey was to estimate the prevalence of viral load (VL) suppression and emergence of HIV drug resistance (HIVDR) among individuals receiving antiretroviral therapy (ART) for 36 months or longer in Viet Nam using a nationally representative sampling method. Methods: The survey was conducted between May and August 2014 using a two-stage cluster design. Sixteen ART clinics were selected using probability proportional to proxy size sampling, and patients receiving ART for at least 36 months were consecutively enrolled. Epidemiological information and blood specimens were collected for HIV-1 VL and HIVDR testing; HIVDR was defined by the Stanford University HIVDR algorithm. Results: Overall, 365 eligible individuals were recruited with a mean age of 38.2 years; 68.4% were men. The mean time on ART was 75.5 months (95% confidence interval [CI]: 69.0–81.9 months), and 93.7% of the patients were receiving non-nucleoside reverse transcriptase inhibitor-based regimens. Of the 365 individuals, 345 (94.7%, 95% CI: 64.1–99.4%) had VL below 1000 copies/mL and 19 (4.6%, 95% CI: 2.8-–7.5) had HIVDR mutations. Discussion Our nationally representative survey found a high level of VL suppression and a low prevalence of HIVDR among individuals who received ART for at least 36 months in Viet Nam. Continued surveillance for HIVDR is important for evaluating and improving HIV programs.

In this study, twenty-five yeast strains were isolated from soil samples collected in the gold mining ore in Gia Lai, Vietnam. Among them, one isolate named GL1 T could highly tolerate Cu 2+ up to 10 mM, and the isolates could also grow in a wide range of pH (3–7), and tem perature (10–40 ℃). Dried biomass of GL1 was able to remove Cu 2+ effectively up to 90.49% with a maximal biosorption capacity of 18.1 mg/g at pH 6, temperature 30 ℃, and incuba tion time 60 min. Sequence analysis of rDNA indicated this strain was closely related to Rhodotorula mucilaginosa but with 1.53 and 3.46% nucleotide differences in the D1/D2 domain of the 28S rRNA gene and the ITS1-5.8S rRNA gene-ITS2 region sequence, respect ively. Based on phylogenetic tree analysis and the biochemical characteristics, the strain appears to be a novel Rhodotorula species, and the name Rhodotorula aurum sp. nov. is pro posed. This study provides us with more information about heavy metal-tolerant yeasts and it may produce a new tool for environmental control and metal recovery operations.

Ischemic diseases are conditions associated with the restriction or blockage of blood supply to specific tissues. These conditions can cause moderate to severe complications in patients, and can lead to permanent disabilities. Since they are blood vessel-related diseases, ischemic diseases are usually treated with endothelial cells or endothelial progenitor cells that can regenerate new blood vessels. However, in recent years, mesenchymal stem cells (MSCs) have shown potent bioeffects on angiogenesis, thus playing a role in blood regeneration. Indeed, MSCs can trigger angiogenesis at ischemic sites by several mechanisms related to their trans-differentiation potential. These mechanisms include inhibition of apoptosis, stimulation of angiogenesis via angiogenic growth factors, and regulation of immune responses, as well as regulation of scarring to suppress blood vessel regeneration when needed. However, preclinical and clinical trials of MSC transplantation in ischemic diseases have shown some limitations in terms of treatment efficacy. Such studies have emphasized the current challenges of MSC-based therapies. Treatment efficacy could be enhanced if the limitations were better understood and potentially resolved. This review will summarize some of the strategies by which MSCs have been utilized for ischemic disease treatment, and will highlight some challenges of those applications as well as suggesting some strategies to improve treatment efficacy.