Enhanced Adsorption of Methylene Blue by Chemically Modified Materials Derived from Phragmites australis Stems.

In this study, the biomass of Phragmites australis was chemically modified using NaOH and subsequently citric acid to produce an effective adsorbent named SA-RPB. The absorbent was characterized using XRD, SEM, BET, and FT-IR methods. The study's findings indicated that the adsorbent existed mainly as cellulose crystals, contained micropores with an average diameter of 15.97 nm, and had a large number of hydroxyl and carboxyl groups on the surface. The adsorption process of SA-RPB was evaluated through the adsorption of methylene blue (MB) dye in aqueous solution. Adsorption kinetics showed that the pseudo-second-order model well described the adsorption process. The adsorption isotherm process satisfactorily fitted with the Langmuir model with the maximum adsorption capacity of 191.49 mg/g at 303 K. These findings show that MB may be efficiently removed from aqueous solutions using the adsorbent made from the raw biomass of Phragmites australis treated with NaOH and then citric acid.

Characteristics of Ag-incorporated bioactive glasses prepared by a modified sol-gel method with a shortened synthesis time and without the use of catalysts.

This work presents the preparation of bioactive glasses 70SiO2-(26 - x)CaO-4P2O5-xAg2O (with x = 0, 1, 3, 10 mol%) by a modified sol-gel method with reduced synthesis time based on hydrothermal reaction in a medium without acid or base catalysts. The synthetic materials were characterized by several physical-chemical techniques such as TG-DSC, XRD, SEM, TEM, and N2 adsorption/desorption measurement. The analysis data confirmed that the glass sample not containing Ag has a completely amorphous structure, while glass samples containing Ag exhibited a pure phase of metallic nano-silver in the glass amorphous phase. All the synthetic glasses have mesoporous structures with particle sizes of less than 30 nm. The addition of silver to the bioactive glass structure in general did not drastically reduce the specific surface areas and pore volumes of glasses as in previous studies. The bioactivity of the silver-incorporated glasses did not reduce, and even increased in the cases of bioactive glass containing 3, and 10 mol% of Ag2O. The biocompatibility of synthetic glasses with fibroblast cells (L-929) was confirmed, even with glass containing high amounts of Ag. Representatively, Ag-incorporated glass samples (sample x = 3, and x = 10) were selected to check the antibacterial ability using bacterial strain Pseudomonas aeruginosa ATCC 27853 (Pa). The obtained results indicated that these glasses exhibited good antibacterial ability to Pseudomonas aeruginosa. Thus, the synthetic method in this study proved to be a fast, environmentally friendly technique for synthesizing Ag-incorporated glass systems. The synthesized glasses show good bioactive, biocompatible, and antibacterial properties.

Timing of initiation of antiretroviral therapy in human immunodeficiency virus (HIV)--associated tuberculous meningitis.

BACKGROUND: The optimal time to initiate antiretroviral therapy (ART) in human immunodeficiency virus (HIV)-associated tuberculous meningitis is unknown. METHODS: We conducted a randomized, double-blind, placebo-controlled trial of immediate versus deferred ART in patients with HIV-associated tuberculous meningitis to determine whether immediate ART reduced the risk of death. Antiretroviral drugs (zidovudine, lamivudine, and efavirenz) were started either at study entry or 2 months after randomization. All patients were treated with standard antituberculosis treatment, adjunctive dexamethasone, and prophylactic co-trimoxazole and were followed up for 12 months. We conducted intention-to-treat, per-protocol, and prespecified subgroup analyses. RESULTS: A total of 253 patients were randomized, 127 in the immediate ART group and 126 in the deferred ART group; 76 and 70 patients died within 9 months in the immediate and deferred ART groups, respectively. Immediate ART was not significantly associated with 9-month mortality (hazard ratio [HR], 1.12; 95% confidence interval [CI], .81-1.55; P = .50) or the time to new AIDS events or death (HR, 1.16; 95% CI, .87-1.55; P = .31). The percentage of patients with severe (grade 3 or 4) adverse events was high in both arms (90% in the immediate ART group and 89% in the deferred ART group; P = .84), but there were significantly more grade 4 adverse events in the immediate ART arm (102 in the immediate ART group vs 87 in the deferred ART group; P = .04). CONCLUSIONS: Immediate ART initiation does not improve outcome in patients presenting with HIV-associated tuberculous meningitis. There were significantly more grade 4 adverse events in the immediate ART arm, supporting delayed initiation of ART in HIV-associated tuberculous meningitis. Clinical Trials Registration. ISRCTN63659091.

Diagnosis of pulmonary tuberculosis in HIV-positive patients by microscopic observation drug susceptibility assay.

The microscopic observation drug susceptibility assay (MODS) is a novel and promising test for the early diagnosis of tuberculosis (TB). We evaluated the MODS assay for the early diagnosis of TB in HIV-positive patients presenting to Pham Ngoc Thach Hospital for Tuberculosis and Lung Diseases in southern Vietnam. A total of 738 consecutive sputum samples collected from 307 HIV-positive individuals suspected of TB were tested by smear, MODS, and the mycobacteria growth indicator tube method (MGIT). The diagnostic sensitivity and specificity of MODS compared to the microbiological gold standard (either smear or MGIT) were 87 and 93%, respectively. The sensitivities of smear, MODS, and MGIT were 57, 71, and 75%, respectively, against clinical gold standard (MODS versus smear, P<0.001; MODS versus MGIT, P=0.03). The clinical gold standard was defined as patients who had a clinical examination and treatment consistent with TB, with or without microbiological confirmation. For the diagnosis of smear-negative patients, the sensitivities of MODS and MGIT were 38 and 45%, respectively (P=0.08). The median times to detection using MODS and MGIT were 8 and 11 days, respectively, and they were 11 and 17 days, respectively, for smear-negative samples. The original bacterial/fungal contamination rate of MODS was 1.1%, while it was 2.6% for MGIT. The cross-contamination rate of MODS was 4.7%. In conclusion, MODS is a sensitive, specific, and rapid test that is appropriate for the detection of HIV-associated TB; its cost and ease of use make it particularly useful in resource-limited settings.