Performance evaluation of nanotubular halloysites from weathered pegmatites in removing heavy metals from water through novel artificial intelligence-based models and human-based optimization algorithm.

The efforts of this study aimed to evaluate the feasibility of the nanotubular halloysites in weathered pegmatites (NaHWP) for removing heavy metals (i.e., Cd2+, Pb2+) from water. Furthermore, two novel intelligent models, such as teaching-learning-based optimization (TLBO)-artificial neural network (ANN), and TLBO-support vector regression (SVR), named as TLBO-ANN and TLBO-SVR models, respectively, were proposed to predict the Cd2+ and Pb2+ absorption efficiencies from water using the NaHWP absorbent. Databases used, including 53 experiments for Pb2+ absorption and 56 experiments for Cd2+ absorption from water, under the catalysis of different conditions, such as initial concentration of Pb2+ and Cd2+, solution pH, adsorbent weight, and contact time. Subsequently, the TLBO-ANN and TLBO-SVR models were developed and applied to predict the efficiencies of Cd2+ and Pb2+ absorption from water, aiming to evaluate the role as well as the effects of different conditions on the absorption efficiencies using the NaHWP absorbent. The standalone ANN and SVM models were also taken into consideration and compared with the proposed hybrid models (i.e., TLBO-ANN and TLBO-SVR). The results showed that the NaHWP detected in a Kaolin mine (Vietnam) with 70% nanotubular halloysites is a potential adsorbent for water treatment to eliminate heavy metals from water. The two novel hybrid models proposed, i.e., TLBO-ANN and TLBO-SVR, also yielded the dominant performances and accuracies in predicting the Cd2+ and Pb2+ absorption efficiencies from water, i.e., RMSE = 1.190 and 1.102, R2 = 0.951 and 0.957, VAF = 94.436 and 95.028 for the TLBO-ANN and TLBO-SVR models, respectively, in predicting the Pb2+ absorption efficiency from water; RMSE = 3.084 and 3.442, R2 = 0.971 and 0.965, VAF = 96.499 and 96.415 for the TLBO-ANN and TLBO-SVR models, respectively, in predicting the Cd2+ absorption efficiency from water. Furthermore, the validation results also demonstrated these findings in practice through 23 experiments with the accuracies of 98.3% and 98.37% for the TLBO-ANN and TLBO-SVR models, respectively, in predicting the Pb2+ absorption efficiency from water; the accuracies of 98.3% and 97.46% for the TLBO-ANN and TLBO-SVR models, respectively, in predicting the Cd2+ absorption efficiency from water. Besides, solution pH was evaluated as the most critical parameter that can be adjusted to enhance the performance of the absorption of the heavy metals in this study. By using the NaHWP absorbent and the novel proposed intelligent models developed, heavy metals can be eliminated entirely from water, providing pure water/clean freshwater without any risk of adverse health effects for the short term or long term.

Streptomyces vietnamensis sp. nov., a streptomycete with violet blue diffusible pigment isolated from soil in Vietnam.

An actinomycete, designated strain GIMV4.0001(T), was isolated from a forest soil sample in Vietnam. It produced white aerial mycelium and violet-blue diffusible pigment on Gause's synthetic agar. The substrate mycelium colour was not sensitive to pH. Micoscopic observations revealed that strain GIMV4.0001(T) produced long, straight chains of cylindrical spores, and chemotaxonomic data confirmed that it belongs to the genus Streptomyces. Melanin was produced, but no antibacterial activity was evident against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Candida albicans or Penicillium citrinum. Analysis of the 16S rRNA gene sequence of strain GIMV4.0001(T) revealed that the highest similarity (99.4 %) was to Streptomyces bikiniensis ATCC 11062(T). However, the DNA-DNA relatedness between strain GIMV4.0001(T) and S. bikiniensis ATCC 11062(T) was found to be 50.3 %. Strain GIMV4.0001(T) could also be differentiated from S. bikiniensis ATCC 11062(T) and other Streptomyces species showing high 16S rRNA gene sequence similarity (98-99 %) based on morphological, physiological and biochemical characteristics. On the basis of its physiological and molecular properties, it is evident that strain GIMV4.0001(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces vietnamensis sp. nov. is proposed. The type strain is GIMV4.0001(T) (=CCTCC M 205143(T)=IAM 15340(T)).

Health related quality of life of adolescents in Vietnam: cross-cultural adaptation and validation of the Adolescent Duke Health Profile.

Quality of life (QOL) of adolescents has been scarcely documented in a general population sample. The study was aimed at translating and adapting the Adolescent Duke Health Profile to Vietnamese, validating the questionnaire, determining reference value, and identifying determinants of poor QOL. Following a cross-cultural methodology, the Adolescent Duke Health Profile (ADHP) had content adapted to Vietnamese by alteration of 2 out of 17 items. Test-retest validity was checked in 408 adolescents. Construct validity and internal consistency were assessed in a 1408 probability sample of adolescents in Vietnam, and determinants were analysed by multiple linear regression. The ADHP showed satisfactory internal consistency (Cronbach's alpha=0.87-0.92) and satisfactory construct validity in relation with drug abuse or not, or with parent situation living in couple or alone. Test-retest reliability was acceptable (ICC=0.7-0.8) and major determinants were age, sex, education, chronic disease, alcohol and drug use. This works provide a validated, simple health related QOL scale suited to adolescent population with reference values. Taking into account determinants identified will help program prevention and intervention health policy and to evaluate the effect of these actions.

Double blind comparison of ibuprofen and paracetamol for adjunctive treatment of uncomplicated typhoid fever.

BACKGROUND: Antipyretics reduce the prolonged, high fever characteristic of typhoid fever. The benefits of nonsteroidal drugs in this role have not been quantified. There have been concerns about the safety of antipyretics in typhoid. METHODS: In a double blind randomized study, 80 Vietnamese children with uncomplicated typhoid fever were randomized to receive identical syrup preparations of ibuprofen (10 mg/kg) or paracetamol (12 mg/kg) every 6 h until 36 h after defervescence. Children with a nalidixic acid-susceptible (Na) isolate of Salmonella typhi were treated with ofloxacin (15 mg/kg/day) for 3 days and those with a nalidixic acid-resistant (Na) isolate were treated for 7 days. RESULTS: S. typhi was isolated from 36 of 40 children randomized to ibuprofen (11 isolates Na) and 37 of 40 randomized to paracetamol (13 isolates Na). The median (range) fever clearance time (hours) was shorter in the ibuprofen group than the paracetamol group (68, 4 to 260 vs. 104, 12 to 404; P = 0.055) as was the area under the temperature time curve above 37 degree C (74, 0 to 237 vs. 127, 0 to 573; P = 0.013). The differences occurred predominantly in the children infected with a NaS. typhi whose infections responded more slowly to antibiotic treatment. There were no major side effects associated with the use of either drug. There were no differences between the two treatment arms in the concentrations of circulating interleukin-6 and tumor necrosis factor alpha during the course of treatment. CONCLUSION: The antipyretic effect of ibuprofen is superior to that of paracetamol in children with typhoid fever, particularly those with prolonged fever. Both antipyretics appeared to be safe.

Steroid withdrawal after pediatric liver transplantation: a long-term follow-up study in 109 recipients.

BACKGROUND: Steroids remain an important component of maintenance immunosuppression in liver transplantation, but when administered for a long period they may be associated with multiple severe side effects, particularly growth suppression in children. This study was conducted to clarify the balance of potential benefits and risks of steroid withdrawal (SW) in pediatric liver transplantation. METHODS: Between April 1984 and July 2000, 109 pediatric recipients with SW and at least 12 months of follow-up after SW were retrospectively reviewed and divided into three groups according to the type of anticalcineurin at SW: group I (cyclosporine, n=25), group II (cyclosporine microemulsion, n=25), and group III (tacrolimus, n=59). Steroids were withdrawn after a three-step reduction of steroid dosage (taper down to the substitution dose of 0.25 mg/kg/day, switch to alternate-day therapy, progressive SW). Patients were regularly followed up for clinical and biochemical monitoring. RESULTS: Median follow-up was 8.1 (range, 1.6-16.8) years. After SW, neither chronic rejection nor graft nor patient loss occurred. A trend toward lower anticalcineurin trough levels was observed in all groups. Glomerular filtration rate and fasting cholesterol were significantly better in group III (P<0.05). Median height z-score in all patients was -1.1 SD on alternate-day steroids versus -0.2 SD at the time of SW. Height z-score was slightly better in group III (NS). Early SW within 2 years after transplantation allowed a slightly better gain in growth. CONCLUSIONS: SW in pediatric liver transplantation is safe and may be beneficial to height outcome. Tacrolimus seems to offer several advantages in the long-term outcome.