22 research outputs found
POPULATION GENETIC DIVERSITY OF CAMELLIA DILINHENSIS ON THE DI LINH PLATEAU OF VIETNAM REVEALED BY ISSR AND SCOT MARKERS
Genetic diversity of naturally distributed Camellia dilinhensis populations on the Di Linh plateau of Vietnam was assessed by the inter-simple sequence repeat (ISSR) and start codon targeted (SCoT) techniques separately and then by combining data from both techniques for satisfactory results. The genetic diversity parameters and genetic distances among individuals found with the ISSR technique (HeI = 0.1420, II = 0.2092, PPBI = 35.22%, GSCsI = 0.765–0.988, and AGSCI = 0.915) are lower than those found with the SCoT technique (HeS = 0.2100, IS = 0.381, PPBS = 52.27%, GSCsS = 0.644–0.985, and AGSCS = 0.866). Based on the combined data from both techniques, the level of genetic diversity of the investigated population is PPB = 43.77%, He = 0.1720, I = 0.2582, and the genetic similarities among individuals are GSCs = 0.764–0.973 with an average of AGSC = 0.894. The SCoT technique differentiated between individuals better and reflected a higher level of genetic diversity in the population than the ISSR technique, but the ISSR technique revealed more loci in Camellia dilinhensis plants than did the SCoT technique
Load Shedding in Microgrid System with Combination of AHP Algorithm and Hybrid ANN-ACO Algorithm
This paper proposes a new load shedding method based on the application of intelligent algorithms, the process of calculating and load shedding is carried out in two stages. Stage-1 uses a backpropagation neural network to classify faults in the system, thereby determining whether or not to shed the load in that particular case. Stage-2 uses an artificial neural network combined with an ant colony algorithm (ANN-ACO) to determine a load shedding strategy. The AHP algorithm is applied to propose load shedding strategies based on ranking the importance of loads in the system. The proposed method in the article helps to solve the integrated problem of load shedding, classifying the fault to determine whether or not to shedding the load and proposing a correct strategy for shedding the load. The IEEE 25-bus 8-generator power system is used to simulate and test the effectiveness of the proposed method, the results show that the frequency of recovery is good in the allowable range
Allogeneic administration of human umbilical cord-derived mesenchymal stem/stromal cells for bronchopulmonary dysplasia: preliminary outcomes in four Vietnamese infants
Background: Bronchopulmonary dysplasia (BPD) is a severe condition in premature infants that compromises lung function and necessitates oxygen support. Despite major improvements in perinatal care minimizing the devastating effects, BPD remains the most frequent complication of extreme preterm birth. Our study reports the safety of the allogeneic administration of umbilical cord-derived mesenchymal stem/stromal cells (allo-UC-MSCs) and the progression of lung development in four infants with established BPD. Methods: UC tissue was collected from a healthy donor, followed by propagation at the Stem Cell Core Facility at Vinmec Research Institute of Stem Cell and Gene Technology. UC-MSC culture was conducted under xeno- and serum-free conditions. Four patients with established BPD were enrolled in this study between May 25, 2018, and December 31, 2018. All four patients received two intravenous doses of allo-UC-MSCs (1 million cells/kg patient body weight (PBW) per dose) with an intervening interval of 7 days. Safety and patient conditions were evaluated during hospitalization and at 7 days and 1, 6 and 12 months postdischarge. Results: No intervention-associated severe adverse events or prespecified adverse events were observed in the four patients throughout the study period. At the time of this report, all patients had recovered from BPD and were weaned off of oxygen support. Chest X-rays and CT scans confirmed the progressive reductions in fibrosis. Conclusions: Allo-UC-MSC administration is safe in preterm infants with established BPD. Trial registration This preliminary study was approved by the Vinmec International Hospital Ethics Board (approval number: 88/2019/QĐ-VMEC; retrospectively registered March 12, 2019)
Enhancement of photocatalytic activity of TIO2 for gaseous toluene removal by simple mechanical mixing with modified zeolite
A zeolite Y was modified by the microwave-assisted method (MWA) for generating mesopores and was mechanically mixed with TiO2 for photocatalytic application. The external surface area, which is represented to the mesopore, was significantly increased about 5 to 10 times in the modified zeolites compared to the parent zeolite. The catalysts were used to catalyze the gas phase photodegradation of toluene, a volatile organic compound (VOC). The photocatalytic activity and stability of the catalyst were improved when the mesoporous zeolite was presented. The mechanical mixture contained 30 wt%. TiO2 and 70 wt%. mesoporous zeolite showed the highest toluene removal efficiency
Optimization of Multiplex-PCR Technique To Determine Azf Deletions in infertility Male Patients
Tung Nguyen Thanh,1 Sang Trieu Tien,2 Phong Nguyen Van,2 Son Dang Thai,3 Thuc Luong Cong,4 Tuan Dinh Le,5 Son Tien Nguyen,5 Tuan Tran Van,1 Hoang Huy Duong,6 Tien Minh Bui,7 Kien Trung Nguyen7 1Military Institute of Clinical Embryology and Histology, Vietnam Military Medical University, Hanoi, 100000, Vietnam; 2Department of Biology and Medical Genetics, Vietnam Military Medical University, Hanoi, 100000, Vietnam; 3Institute of Biological and Food Technology, Hanoi Open University, Hanoi, 100000, Vietnam; 4Cardiovascular Center, Military Hospital 103, Vietnam Military Medical University, Hanoi, 100000, Vietnam; 5Department of Rheumatology and Endocrinology, Military Hospital 103, Vietnam Military Medical University, Hanoi, 100000, Vietnam; 6Department of Neurology, Thai Binh University of Medicine and Pharmacy, Thai Binh, 410000, Vietnam; 7Department of Obstetrics and Gynecology, Thai Binh University of Medicine and Pharmacy, Thai Binh, 410000, VietnamCorrespondence: Sang Trieu Tien, Department of Biology and Medical Genetics, Vietnam Military Medical University, Hanoi, 100000, Vietnam, Email [email protected]: To optimize the multiplex polymerase chain reaction (M-PCR) technique to diagnose microdeletions of azoospermia factors (AZF) on the Y chromosome and initially apply the technique to diagnose male patients with sperm density less than 5× 106 million sperm/mL was assigned to do a test to check for AZF microdeletions on the Y chromosome.Methods: Based on the positive control samples which belong to male subjects who have had 2 healthy children without any assisted reproductive technologies, the M-PCR method was developed to detect simultaneously and accurately AZF microdeletions on 32 male patients with sperm densities below 5× 106 million sperm/mL of semen at the Department of Biology and Medical Genetics – Vietnam Military Medical University.Results: Successful optimization of the M-PCR technique including 7 reactions arranged according to each AZFabc region using 24 STS/gene on the Y chromosome. Initial application to diagnose AZF deletion on 32 azoospermic and oligospermic men reveals that AZFa deletion accounts for 6.25% (2/32); deletion of all 3 regions AZFa,b,c with 18.75% (6/32 cases); The combined deletion rate of AZFb,c is highest, accounting for 56.24% (18/32 patients).Conclusion: Successfully optimized the M-PCR technique in identifying AZF microdeletions using 24 sequence tagged sites (STS)/gene for azoospermic and oligozoospermic men. The M-PCR technique has great potential in the application of AZF deletion diagnosis.Keywords: male infertility, azoospermia factors, AZF, multiplex polymerase chain reaction, M-PCR, sequence tagged sites, ST
Rifampicin tolerance and growth fitness among isoniazid-resistant clinical Mycobacterium tuberculosis isolates: an in-vitro longitudinal study.
Antibiotic tolerance in Mycobacterium tuberculosis leads to less effective bacterial killing, poor treatment responses and resistant emergence. There is limited understanding of antibiotic tolerance in clinical isolates of M. tuberculosis . Therefore, we investigated the rifampicin tolerance of M. tuberculosis isolates, with or without pre-existing isoniazid-resistance. In-vitro rifampicin survival fractions determined by minimum duration of killing assay in isoniazid susceptible (n=119) and resistant (n=84) M. tuberculosis isolates. Rifampicin tolerance was correlated with bacterial growth, rifampicin minimum inhibitory concentrations (MICs) and isoniazid-resistant mutations. The longitudinal isoniazid-resistant isolates were analyzed for rifampicin tolerance based on collection time from patients and associated emergence of genetic variants. The median duration of rifampicin exposure reducing the M. tuberculosis surviving fraction by 90% (minimum duration of killing-MDK90) increased from 1.23 (95%CI 1.11; 1.37) and 1.31 (95%CI 1.14; 1.48) to 2.55 (95%CI 2.04; 2.97) and 1.98 (95%CI 1.69; 2.56) days, for IS and IR respectively, during 15 to 60 days of incubation respectively. Increase in MDK90 time indicated the presence of fast and slow growing tolerant sub-populations. A range of 6 log 10 -fold survival fraction enabled classification of tolerance as low, medium or high and revealed isoniazid-resistance association with increased tolerance with faster growth (OR=2.68 for low vs. medium, OR=4.42 for low vs. high, P -trend=0.0003). The high tolerance in longitudinal isoniazid-resistant isolates was specific to those collected during rifampicin treatment in patients and associated with bacterial genetic microvariants. Our study identifies a range of rifampicin tolerance and reveals that isoniazid resistance is associated with higher tolerance with growth fitness. Furthermore, rifampicin treatment may select isoniazid-resistant isolate microvariants with higher rifampicin tolerance, with survival potential similar to multi-drug resistant isolates. These findings suggest that isoniazid-resistant tuberculosis needs to be evaluated for rifampicin tolerance or needs further improvement in treatment regimen
Some preliminary results of paleo-tsunami study in the coastal region of the Nghe An province, Vietnam
In the coastal region of the Nghe An province, the geomorphology is characterized by appearances of fields of arca granosa with placura placenta and hills of placura placenta with arca granosa, namely: The hills of placura placenta with the arca granosa shells in the Quynh Van and Nghi Tien communes; the fields of arca granosa with the placura placenta: deep-seated in the Quynh Nghia, Dien Chau and along the Nghi Yen coast which have age of 4,500 - 4,300 yrs.; The appearance of the placura placenta-arca granosa shell’s fields and hills which do not originate from either marine transgression in the Holocene epoch, tectonic movement or artificiality; Our results suggest that there were three tsunami events occurring in the past during the periods of 4,500 - 4,300; 4,100 - 3,900 and 900 - 600 yrs., respectively in the region
Drivers of antibiotic use in Vietnam: implications for designing community interventions.
INTRODUCTION: Antimicrobial resistance is a global challenge that threatens our ability to prevent and treat common infectious diseases. Vietnam is affected by high rates of antimicrobial resistant infections, driven by the overuse of antibiotics and the Vietnamese government has recognised antimicrobial resistance as a health security priority. This study aimed to understand how people in Vietnam use antibiotics in community settings, and the factors that impact their practices and decision-making regarding antibiotics. METHODS: We conducted 43 qualitative in-depth interviews with 50 community members in two urban and two rural sites in Vietnam. We conducted iterative, inductive thematic analysis alongside data collection through a process of systematic debriefings based on detailed interview summaries. Through this process, we developed a coding framework that was then applied to transcribed interview data. RESULTS: Frequent and indiscriminate use of antibiotics was driven by the powerful appeal that antibiotics held for many Vietnamese consumers. Consumers were discerning in making decisions in their purchase and use of antibiotics. Consumers' decisions were affected by perceptions of what constitutes high-quality medicine (effective, strong, accessible and affordable); privileging symptom control over diagnosis; social constructions of antibiotics as a trusted remedy with embodied evidence of prior efficacy, which is reinforced by advice from trusted sources in their community; and varied, generally incomplete, understanding of the concept of antibiotic resistance and its implications for individuals and for public health.
CONCLUSION: Antibiotic use at the community and primary care level in Vietnam is driven by community members' social and economic response to what constitutes effective healthcare, rather than biomedical logic. Community-based interventions to reduce unnecessary antibiotic use need to engage with the entangled socio-structural factors that 'resist' current public health efforts to ration antibiotic use, alongside biomedical drivers. This study has informed the design of a community-based trial to reduce unnecessary antibiotic use
Rifampicin tolerance and growth fitness among isoniazid-resistant clinical Mycobacterium tuberculosis isolates from a longitudinal study
Antibiotic tolerance in Mycobacterium tuberculosis reduces bacterial killing, worsens treatment outcomes, and contributes to resistance. We studied rifampicin tolerance in isolates with or without isoniazid resistance (IR). Using a minimum duration of killing assay, we measured rifampicin survival in isoniazid-susceptible (IS, n=119) and resistant (IR, n=84) isolates, correlating tolerance with bacterial growth, rifampicin minimum inhibitory concentrations (MICs), and isoniazid-resistant mutations. Longitudinal IR isolates were analyzed for changes in rifampicin tolerance and genetic variant emergence. The median time for rifampicin to reduce the bacterial population by 90% (MDK90) increased from 1.23 days (IS) and 1.31 days (IR) to 2.55 days (IS) and 1.98 days (IR) over 15–60 days of incubation, indicating fast and slow-growing tolerant sub-populations. A 6 log10-fold survival fraction classified tolerance as low, medium, or high, showing that IR is linked to increased tolerance and faster growth (OR = 2.68 for low vs. medium, OR = 4.42 for low vs. high, p-trend = 0.0003). High tolerance in IR isolates was associated with rifampicin treatment in patients and genetic microvariants. These findings suggest that IR tuberculosis should be assessed for high rifampicin tolerance to optimize treatment and prevent the development of multi-drug-resistant tuberculosis