Equilibrium and Kinetic Studies on the Removal of Basic Violet 10 from Aqueous Solutions Using Activated Carbons Prepared from Industrial Wastes

Low-cost adsorbents prepared from industrial wastes such as sugarcane bagasse (BC), rice husk (RC), and textile waste cloth (TC) are identified as suitable sorbents for removing basic violet 10 (BV). Fourier transform infrared (FTIR) and scanning electron microscopic (SEM) studies were carried out to characterize the prepared sorbents. The effects of dosage, time, and pH on dye removal were examined. It was observed that BV sorption takes place in acidic, neutral, and alkaline aqueous solutions. The work discussed the best-fit sorption isotherms among Freundlich and Langmuir, in addition to the reaction- and diffusion-based kinetic models. Based on the data obtained, it was found that the BV sorption took place in acidic, neutral, and alkaline aqueous solutions and sorption kinetics found to be controlled by pseudo-second-order and pore diffusion models. Also, thermodynamic parameters such as ΔG ^o, ΔH ^o, ΔS ^o, and E _a were calculated in order to understand the nature of the sorption process. The maximum dye removal capacity (DRC) was found to be 5608, 1244, and 27,495 mg/kg for BC, RC, and TC, respectively. Collectively, it can be concluded that the activated carbon sorbents, prepared from the named wastes, can used to adequately remove the basic violet dye from its aqueous waste solution.     

Antifungal activity of essential oils and their combinations in in vitro and in vivo conditions

Natural additives are in demand for the control of microbial growth in foods. Several natural compounds including essential oils (EOs) are being explored for food uses. In the present investigation, the antifungal activity of cinnamaldehyde, eugenol, peppermint and clove EOs and their combinations was evaluated against 12 species of Aspergillus, Fusarium, Penicillium and Rhizopus in in vitro and tomato fruit system (in-vivo). The EOs were able to inhibit complete growth of tested fungi at or below 0.6% level and 80?μL of EOs (except peppermint oil) in in vitro condition and tomato system, respectively. The fractional inhibitory studies showed either additive or indifferent effect by combining eugenol and peppermint, and indifferent or antagonist effect by combining the cinnamaldehyde and clove in both in vitro and in vivo studies. The findings may be useful for application of these EOs in foods, but their effects on organoleptic quality of foods need to be investigated.     

Fabrication of chitin-chitosan/nano ZrO(2) composite scaffolds for tissue engineering applications

The urge to repair and regenerate natural tissues can now be satisfactorily fulfilled by various tissue engineering approaches. Chitin and chitosan are the most widely accepted biodegradable and biocompatible materials subsequent to cellulose. The incorporation of nano ZrO₂ onto the chitin-chitosan scaffold is thought to enhance osteogenesis. Hence a nanocomposite scaffold was fabricated by lyophilization technique using chitin-chitosan with nano ZrO₂. The prepared nanocomposite scaffolds were characterized using SEM, FTIR, XRD and TGA. In addition, the swelling, degradation, biomineralization, cell viability and cell attachment of the composite scaffolds were also evaluated. The results demonstrated better swelling and controlled degradation in comparison to the control scaffold. Cell viability studies proved the non toxic nature of the nanocomposite scaffolds. Cells were found to be attached to the pore walls and spread uniformly throughout the scaffolds. All these results suggested that the developed nanocomposite scaffolds possess the prerequisites for tissue engineering scaffolds and could be used for various tissue engineering applications.     

Synthesis, characterization and cytocompatibility studies of α-chitin hydrogel/nano hydroxyapatite composite scaffolds

α-chitin hydrogel/nano hydroxyapatite (nHAp) composite scaffold have been synthesized by freeze-drying approach with nHAp and α-chitin hydrogel. The prepared nHAp and nanocomposite scaffolds were characterized using DLS, SEM, FT-IR, XRD and TGA studies. The porosity, swelling, degradation, protein adsorption and biomineralization (calcification) of the prepared nanocomposite scaffolds were evaluated. Cell viability, attachment and proliferation were investigated using MG 63, Vero, NIH 3T3 and nHDF cells to confirm that the nanocomposite scaffolds were cytocompatible and cells were found to attach and spread on the scaffolds. All the results suggested that these scaffolds can be used for bone and wound tissue engineering.     

The Profile and Treatment Outcomes of the Older (Aged 60 Years and Above) Tuberculosis Patients in Tamilnadu,South India

Background

With changing demographic patterns in the context of a high tuberculosis (TB) burden country, like India, there is very little information on the clinical and demographic factors associated with poor treatment outcome in the sub-group of older TB patients. The study aimed to assess the proportion of older TB patients (60 years of age and more), to compare the type of TB and treatment outcomes between older TB patients and other TB patients (less than 60 years of age) and to describe the demographic and clinical characteristics of older TB patients and assess any associations with TB treatment outcomes.

Methods

A retrospective cohort study involving a review of records from April to June 2011 in the 12 selected districts of Tamilnadu, India. Demographic, clinical and WHO defined disease classifications and treatment outcomes of all TB patients aged 60 years and above were extracted from TB registers maintained routinely by Revised National TB Control Program (RNTCP).

Results

Older TB patients accounted for 14% of all TB patients, of whom 47% were new sputum positive. They had 38% higher risk of unfavourable treatment outcomes as compared to all other TB patients (Relative risk (RR)-1.4, 95% CI 1.2–1.6). Among older TB patients, the risk for unfavourable treatment outcomes was higher for those aged 70 years and more (RR 1.5, 95% CI 1.2–1.9), males (RR 1.5, 95% CI 1.0–2.1), re-treatment patients (RR 2.5, 95% CI 1.9–3.2) and those who received community-based Direct Observed Treatment (RR 1.4, 95% CI 1.1–1.9).

Conclusion

Treatment outcomes were poor in older TB patients warranting special attention to this group – including routine assessment and recording of co-morbidities, a dedicated recording, reporting and monitoring of outcomes for this age-group and collaboration with National programme of non-communicable diseases for comprehensive management of co-morbidities.     

HIV-1 envelope accessible surface and polarity: clade, blood, and brain

The human immunodeficiency virus type-1 (HIV-1) gp160 (gp120-gp41 complex) trimer envelope (ENV) protein is a potential vaccine candidate for HIV/AIDS. HIV-1 vaccine development has been problematic and charge polarity as well as sequence variation across clades may relate to the difficulties. Further obstacles are caused by sequence variation between blood and brain-derived sequences, since the brain is a separate compartment for HIV-1 infection. We utilize a threedimensional residue measure of solvent exposure, accessible surface area (ASA), which shows that major segments of gp120 and gp41 known structures are solvent exposed across clades. We demonstrate a large percent sequence polarity for solvent exposed residues in gp120 and gp41. The range of sequence polarity varies across clades, blood, and brain from different geographical locations. Regression analysis shows that blood and brain gp120 and gp41 percent sequence polarity range correlate with mean Shannon entropy. These results point to the use of protein modifications to enhance HIV-1 ENV vaccines across multiple clades, blood, and brain. It should be noted that we do not address the issue of protein glycosylation here; however, this is an important issue for vaccine design and development. ABBREVIATIONS: HIV-1 - human immunodeficiency virus type 1, AIDS - acquired immunodeficiency syndrome, ENV - envelope, gp160 - 160,000d glycoprotein, gp120 - 120,000d glycoprotein, gp41 - 41,000d glycoprotein, LANL - Los Alamos National Laboratories, PDB - Protein Data Bank, HVTN - STEP HIV vaccine trial, AA - amino acids, MSA - multiple sequence alignment, ASA - accessible surface area, SNPs- single nucleotide polymorphisms, HAART - Highly Active Antiretroviral Therapy, CCR5 - C-C chemokine receptor type 5, CNS - central nervous system, HIVE - HIV encephalitis, P - polarity, NP - non-polarity, CTL - cytotoxic T lymphocyte, NIAID - National Institute of Allergy and Infectious Diseases.     

Tetracycline nanoparticles loaded calcium sulfate composite beads for periodontal management

Background

The objective of this study was to fabricate, characterize and evaluate in vitro, an injectable calcium sulfate bone cement beads loaded with an antibiotic nanoformulation, capable of delivering antibiotic locally for the treatment of periodontal disease.

Methods

Tetracycline nanoparticles (Tet NPs) were prepared using an ionic gelation method and characterized using DLS, SEM, and FTIR to determine size, morphology, stability and chemical interaction of the drug with the polymer. Further, calcium sulfate (CaSO₄) control and CaSO₄-Tet NP composite beads were prepared and characterized using SEM, FTIR and XRD. The drug release pattern, material properties and antibacterial activity were evaluated. In addition, protein adsorption, cytocompatibility and alkaline phosphatase activity of the CaSO₄-Tet NP composite beads in comparison to the CaSO₄ control were analyzed.

Results

Tet NPs showed a size range of 130 ± 20 nm and the entrapment efficiency calculated was 89%. The composite beads showed sustained drug release pattern. Further the drug release data was fitted into various kinetic models wherein the Higuchi model showed higher correlation value (R² = 0.9279) as compared to other kinetic models. The composite beads showed antibacterial activity against Staphylococcus aureus and Escherichia coli. The presence of Tet NPs in the composite bead didn't alter its cytocompatibility. In addition, the composite beads enhanced the ALP activity of hPDL cells.

Conclusions

The antibacterial and cytocompatible CaSO₄-Tet NP composite beads could be beneficial in periodontal management to reduce the bacterial load at the infection site.

General significance

Tet NPs would deliver antibiotic locally at the infection site and the calcium sulfate cement, would itself facilitate tissue regeneration.