Search

Discharge of liquid effluents from industries in an open environment causes severe pollution to natural water sources and carcinogenicity to aquatic animals. Present study reports the utilization of ion-imprinted polyvinylidene/1-butyl-3-methylimidazolium tetrafluoroborate (PVDF/RTIL) nanofibers fabricated via facile electrospinning technique, for effective recovery of europium III [Eu3+] ions for supplementing its supply for technological applications. RTIL used in this study provided active sites for recovery of Eu3+ ions through its functional groups. Maximum recovery of Eu3+ ions on PVDF/RTIL nanofibers was found to be 22.37 mg/g, with 90% of recovery achieved within 3 h (at pH ∼ 7.0, and T = 298 K). FE-SEM, FTIR and BET characterizations confirmed the recovery of Eu3+ ions on PVDF/RTIL nanofibers. Experimental parameters like adsorption isotherm, influence of pH of solution, and initial metal ion concentration were also investigated. Results demonstrated that recovery of Eu3+ ions onto ion-imprinted PVDF/RTIL nanofibers corresponds to Freundlich isotherm model (R2 = 0.98297). For investigation of economic viability sequential adsorption–desorption experiments were carried out which confirmed that PVDF/RTIL nanofibers can be readily regenerated and reused for five successive cycles without significant drop in effectiveness. Results demonstrate that PVDF/RTIL nanofibers can be effectively used for recovery of Eu3+ ions from mimicked liquid effluents.

Typhoid remains a global public health problem, and quick accurate immunodiagnosis is needed. Here, we examined the performance of the 5-min TUBEX O9-antibody detection kit in 243 outpatients (mostly children and infants) in their first week of fever and 57 healthy subjects in the Bangladesh community. Based on culture results, TUBEX was 91.2% (31/34) sensitive and 82.3% (172/209) specific in febrile subjects. However, specificity was better in nonfebrile healthy subjects (89.5%, 51/57) or in febrile individuals who serologically had dengue fever (90.5%, 57/63), suggesting that some culture-negative febrile individuals could be truly typhoidal. These individuals were also positive in an anti-crude O9 enzyme-linked immunosorbent assay (ELISA) and the Widal test. Regression analysis of the TUBEX and ELISA results showed good concordance between them, better with the combined IgM-IgG ELISA than with IgM alone, suggesting that TUBEX detects IgM antibodies not necessarily by themselves, as previously reported, but with the help of IgG antibodies.

A simple technique is described for the control and determination of the oxygen stoichiometry between 6.95–5.83 of pure deoxygenated YBa 2 Cu 3 O 7−δ (YBCO). By studying samples prepared using this method, two anomalous properties, namely (1) the step-like increase of the c -axis length of the crystal unit cell, and (2) the changes of the superconducting (SC) transition temperature, T c , clearly showing the presence of two familiar plateaus as oxygen is gradually removed from YBCO have been reproduced. These two properties, first observed by Cava et al. by a Zr gettering technique thus appear to be inherent to pure YBCO. In addition, it is also found that the crystal structure of YBCO does not break down for an oxygen stoichiometry as low as 5.83. The extra (0.17) O atom per unit cell difference between 6.0 and 5.83 is believed to be lost from the O(4) sites. The technique adopted in this study which involves isothermal vacuum annealing (VA) can, therefore, be used as an alternative to the Zr gettering method for tuning various amounts of oxygen per unit cell in YBCO.

A community-based longitudinal study was carried out at Matlab, Bangladesh, to investigate the magnitude of the problem of persistent diarrhea; 705 children aged < 5 y were followed, yielding 7300 child-months of observation in 1 y. Morbidity data were collected every fourth day by home visit, anthropometric status was determined monthly, and cell-mediated immune status was assessed every 3 mo. The incidence of persistent diarrhea was 34 episodes per 100 child-years; rates were highest in infancy and declined through the remainder of childhood. In a logistic-regression model, weight-for-height status and immune status were significant predictors of persistent diarrhea. Compared with those at zero Z score, children with weight-for-height at -2 would have a 3.5 times increased risk of persistent diarrhea. Compared with immunocompetent children, immunodeficient children had about twice the risk of developing persistent diarrhea. Thus, nutritional status and cell-mediated immune status were important independent risk factors for persistent diarrhea.

Epidemics of cholera caused by Vibrio cholerae 01 occur regularly in Bangladesh, but until lately V cholerae non-01 has been associated only with sporadic cases of diarrhoeal disease in many parts of the world, including Bangladesh. We describe a large epidemic of cholera-like disease in Bangladesh that is due to a V cholerae non-01. The epidemic began in December, 1992, in southern Bangladesh and spread throughout the country. By the end of March 107 297 cases of diarrhoea and 1473 deaths had been reported. The disease is indistinguishable from cholera in clinical features and response to treatment, but most of the cases are in adults, which suggests that the population has no previous immunological experience of the organism. At two centres 375 (40%) of 938 and 236 (48%) of 492 rectal swabs were positive for V cholerae non-01, as were 5 of 54 surface water samples. 55 isolates of V cholerae non-01 were studied in detail. They resembled El Tor vibrios in being resistant to polymyxin B and positive for agglutination of chicken erythrocytes. The strain did not belong to any of the 138 known V cholerae serogroups; so a new serogroup 0139, with the suggested name Bengal, is proposed. All the isolates studied produced large amounts of an enterotoxin apparently identical to cholera toxin. This strain seems to have pandemic potential. It is important that other countries in southeast Asia are aware of the strain's potential to cause severe morbidity and mortality.

A double-blind, randomised, placebo-controlled trial was conducted to evaluate the safety and toxicity of vitamin A supplementation within the Expanded Programme on Immunisation (EPI) in rural Bangladesh. 191 infants received 3 doses of either 50,000 IU of vitamin A or placebo at about 1.5, 2.5, and 3.5 months and were examined on days 1, 2, 3, and 8 after supplementation. 11 infants (11.5%) supplemented with vitamin A had episodes of bulging of the fontanelle as opposed to 1 (1%) in the placebo group. 16 of the 17 events occurred in the vitamin A supplemented group. No other side effects were noted. There was a tendency towards a cumulative effect of toxicity with increasing doses.The International Center for Diarrhoeal Disease Research, Bangladesh, conducted a double-blind, randomized, placebo-controlled trial in the Matlab to examine the possibility of side effects in 191 infants who received 3 doses of either 50,000 IU vitamin A or a placebo at 1.5, 2.5, and 3.5 months within the Expanded Program of Immunization. Physicians examined the infants on the day of supplementation on days 1,3 and 8 after supplementation. The fontanelles bulged in 12 infants. The incidence of fontanelle bulging was more common in the vitamin A group than in the placebo group (11.5 vs. and 1%). There were 17 fontanelle bulging episodes, 16 taking place after vitamin A supplementation (5.5 vs. 0.3% after placebo supplementation). 8 (50%) of the vitamin A induced bulged fontanelle episodes occurred after the 3rd dose. 3 infants had fontanelle bulging episodes after the 2nd and 3rd doses. 2 other infants had these episodes after the 1st and 3rd doses. The bulging episodes persisted for 24-48 hours in all but 2 cases (48-72 hours) and returned to normal without treatment. No infant with a bulging fontanelle died. No other side effects occurred. The increased incidence of bulging fontanelles among infants receiving vitamin A supplementation and the fact that almost all episodes occurred after vitamin A supplementation suggested that vitamin A supplementation caused the bulging fontanelles. Increased intracranial pressure caused by vitamin A toxicity was responsible for the bulging fontanelles.