Magnetically Recyclable Spinel Mn x Ni1−x Fe2 O 4 (x= 0.0–0.5) Nano-photocatalysts: Structural,Morphological and Opto-magnetic Properties

Manganese doped nickel ferrite (Mn _x Ni_1?x Fe₂ O ₄: x = 0.0–0.5) spinel nanoparticles (NPs) were successfully prepared by a facile microwave combustion method (MCM) using urea as the fuel. The prepared samples were characterized by different techniques. Powder X-ray diffraction (XRD) analysis was confirmed the formation of a single-phase NiFe₂ O ₄ spinel structure. The average crystallite sizes of the samples were in the range of 11.49 to 17.24 nm, which was confirmed by Sherrer’s formula. The morphology of the samples showed a nanoparticle-like structure with smaller agglomeration, which was confirmed by high-resolution scanning electron microscopy (HR-SEM). The particle size diameter ranges from 15 to 20 nm, which was confirmed by high-resolution transmission electron microscopy (HR-TEM). Energy dispersive X-ray (EDX) analysis confirmed the elemental composition, which was also evidence for the formation of single pure phase. Selected area electron diffraction (SAED) analysis showed well crystalline nature. UV-visible diffuse reflectance spectra (DRS) and photoluminescence (PL) spectrum analysis was used to calculate the optical band gap, and the values are slightly increased (2.02 to 2.42 eV) with increasing the Mn-dopant, due to the decreasing of particle size, which may be due to the quantum confinement effect. Magnetic properties of the samples were analyzed by vibrating sample magnetometer (VSM) technique, which showed the magnetization (M _s ) value of the samples are increased with increasing Mn content and reach a maximum value of 67.82 emu/g for Mn_0.5Ni_0.5Fe₂ O ₄ sample. Photo-catalytic activity of the samples was measured and showed the photocatalytic degradation (PCD) of methylene blue dye with good results. The catalyst was magnetically recycled and reused five consecutive cycles and showed good reproducibility without change of catalytic activity.     

Incidence and clinical manifestations of HIV-1 infection in multitransfused thalassaemic Indian children

Four hundred and six multitransfused thalassaemic children attending the paediatric clinic in Manipur, India, were screened for HIV antibodies. There were 46 (8.9%) ELISA antibody-positive children and the diagnosis was reaffirmed by Western blot assay. The immunologic status of the seropositive children was evaluated by a) absolute lymphocyte count, b) percentage of ratio of T helper (CD4+) and T suppressor (CD8+) cells, c) quantitative Ig, G, M and A levels and d) delayed-type cutaneous hypersensitivity (DTH) testing. Twelve of the 36 seropositive children were clinically symptomatic with AIDS. The clinical and immunological status of seropositive children are compared with matched seronegative thalassaemic control groups. Five of the 12 symptomatic seropositive children had received continued antiretroviral treatment. The mortality rate at the end of 36 weeks of itinerary was 20% in contrast to 50% in the untreated children. This report highlights the value of early recognition and therapeutic intervention in a selected high risk paediatric population.     

Dewatering of microalgal culture for biodiesel production: exploring polymer flocculation and tangential flow filtration

BACKGROUND: Conventional biodiesel production relies on trans‐esterification of lipids extracted from vegetable crops. However, the use of valuable vegetable food stocks as raw material for biodiesel production makes it an unfeasibly expensive process. Used cooking oil is a finite resource and requires extra downstream processing, which affects the amount of biodiesel that can be produced and the economics of the process. Lipids extracted from microalgae are considered an alternative raw material for biodiesel production. This is primarily due to the fast growth rate of these species in a simple aquaculture environment. However, the dilute nature of microalgae culture puts a huge economic burden on the dewatering process especially on an industrial scale. This current study explores the performance and economic viability of chemical flocculation and tangential flow filtration (TFF) for the dewatering of Tetraselmis suecica microalgae culture. RESULT: Results show that TFF concentrates the microalgae feedstock up to 148 times by consuming 2.06 kWh m^?3 of energy while flocculation consumes 14.81 kWh m^?3 to concentrate the microalgae up to 357 times. Economic evaluation demonstrates that even though TFF has higher initial capital investment than polymer flocculation, the payback period for TFF at the upper extreme of microalgae revenue is ～1.5 years while that of flocculation is ～3 years. CONCLUSION: These results illustrate that improved dewatering levels can be achieved more economically by employing TFF. The performances of these two techniques are also compared with other dewatering techniques. Copyright © 2009 Society of Chemical Industry     

Impact of pregnancy on maternal AIDS

OBJECTIVE: To assess the impact of pregnancy on maternal acquired immunodeficiency syndrome (AIDS) among tribal women in India. STUDY DESIGN: From February 1992 to February 1996, 71 tribal women from Manipur, India, with AIDS (Centers for Disease Control stage iii/iv), matched for age, parity, CD4 lymphocyte count and demographic characteristics, were recruited into a prospective study. Thirty-two (49%) of these women were pregnant (8-10 weeks) (group A) and 38 (51%) nonpregnant (group B). RESULTS: Pneumocystis carinii pneumonia followed by miliary tuberculosis and wasting disease were the most common AIDS-defining illness and cause of maternal death in both groups. A total of 28 (39%) women died as a direct result of their AIDS-defining illness; 10 (27%) of them were among the nonpregnant women as compared to 18 (56%) deaths among the pregnant women (P = .17, odds ratio 3.7285, 95% confidence interval 1.23, 11.58). Three (16%) of these 18 deaths occurred within 14 weeks of an uneventful first-trimester medical termination of pregnancy. Thirteen women (41%) died undelivered at 30-34 weeks' gestation, and two died within 3 weeks of delivery. Fourteen (44%) women vaginally delivered 14 preterm infants, between 28 and 35 weeks' gestation. Eleven of these infants died within six weeks; nine deaths were a direct result of prematurity and clinical diagnosis of an AIDS-defining illness. The mean survival time was 9.72 months for the pregnant women and 22.6 months for the nonpregnant women (P = .066). CONCLUSION: Pregnancy increased maternal and fetal mortality in these AIDS-infected women.     

Inhibition of rotavirus infection in vitro and in vivo by a synthetic peptide from VP4

A synthetic peptide corresponding to bovine rotavirus C486 (BRV) VP4 amino acid sequence 232-255 (VP4-peptide) was studied with the objective of defining the origin of the protective immune response reported previously by Ijaz et al. (J. Virol. 1991, 65, 3106-3113). Pretreatment of MA-104 cells with the VP4-peptide before infection with rotavirus prevented both the attachment of 35S-labelled virus and plaque formation in vitro. In vivo studies using a murine rotavirus model demonstrated that intragastric administration of VP4-peptide protected subjects from challenge with virulent rotavirus. These results clearly indicate the importance of this epitope in virus-cell interactions and their potential as a rotavirus vaccine candidate.