Chemistry

The location of water quality monitoring stations in a water distribution system should be such that the network is represented with the minimum number of monitoring stations. The present guidelines do not describe how the sampling locations are to be optimally identified. The ...

Alkaline pretreatment has been known as the most popular method to process lignocellulosic materials for bioethanol production due to its simplicity and high efficiency. However, the waste water of the process has a very high basicity, which requires neutralization with acids upon further disposal. In this study, rubber wood saw dust (Hevea brasiliensis) was employed as lignocellulosic material and its pretreatment was inspected with both diluted H2SO4 and NaOH in different combination ways. Hereby, acid was used not only for waste water neutralization but also to contribute to lignin removal. Analysis results showed that an aqueous solution of 2.0 - 2.5 wt.% H2SO4 can be used to treat the biomass followed by alkaline pretreatment. By this so-called combo-pretreatment technique, cellulose was well preserved without significant hydrolysis while the final pretreatment efficiency was up to 63.0%, compared to 48.2% of using only the alkaline solution and 13.7% of using only the acidic s...

Mouse embryo implantation is a highly invasive and controlled process that involves remodeling and degradation of the extracellular matrix of the uterus. Matrix metalloproteinases (MMPs) are the main proteinases facilitating this process. Extracellular matrix metalloproteinase inducer (EMMPRIN) can stimulate the production of MMPs and is required for successful implantation in the mouse. The aims of the present study were to examine the expression profiles of mRNA and proteins for EMMPRIN and MMPs in the developing mouse embryo in vitro, and to study whether EMMPRIN protein induces the production of MMPs by mouse blastocysts. EMMPRIN mRNA, detected by RT-PCR, was present at all stages of embryo development from the one-cell to the blastocyst outgrowth. EMMPRIN protein, observed by confocal microscopy, was present on the cell surface at the same stages of development as was the mRNA. Of seven MMPs studied, murine collagenase-like A (Mcol-A), murine collagenase-like B (Mcol-B) and gel...

Interferon beta (IFNβ) is naturally occurring cytokine made and secreted by immune cells in response to stimuli. Non-glycosylated interferon beta Ser 17 mutein (IFNβ-Ser17) is widely used for treatment of active relapsing multiple sclerosis. Despite all efforts to humanize this protein, it is still immunogenic by increasing of anti-IFNβ antibodies in patients. In order to decrease its antigenicity, identification and modification of epitopes is an effective step. We used a peptide microarray to detect linear epitopes by screening a synthetic peptide library. The interaction between synthetic peptides and anti-IFNβ antibodies presented in enriched plasma of transgenic and non-transgenic mice, were detected using chemiluminescence. With this technique, three 10-mer peptides were identified as linear epitopes. Computational algorithms were used to select residues suitable for point mutations in each epitope. These three 10-mer epitopes were mutated with the aim to reduce antigenicity of IFNβ. Three variants of IFNβ each with one mutated epitope were produced. The results showed no binding affinity of the mutated epitopes to anti-IFNβ antibodies compared with native epitopes. Biological activities of these epitope variants were measured; equal antiviral activity of the C-terminus mutated and the near N-terminus mutated were evaluated compare to the standard. Our results showed that the antigenicity of IFNβ epitope variants were reduced in vitro.

Advances in nanobiotechnology and targeting strategy could improve the delivery of therapeutic molecules into cancer cells, leading to improved treatment efficiency with minimal side effects on normal cells. To design an efficient nanocarrier, consideration of parameters that facilitate direct drug delivery into the target cells is important. We studied the effect of single-wall carbon nanotubes (SWNTs) size on their cell internalization level via the folate receptor-mediated pathway through folic acid targeting. Folate-SWNTs were covalently synthesized and characterized. Folate-SWNTs ≤ 450 nm had lower cell internalization level than folate-SWNTs >450 nm with a P value of ≤0.01. This indicated that using folate-SWNT with an average length of ≤450 nm was not suitable for receptor-mediated cancer cell targeting. Receptor-mediated uptake of folate-SWNTs is dependent on the nanoparticle length. However, sub-450 nm SWNTs could serve as a vehicle to transfer nucleic acids into the cells due to direct cell penetrance based on their needle-like structure. We find that SWNTs larger than 450 nm were suitable to target the cells through receptors. These results might provide a promising approach for designing more effective targeted delivery systems based on SWNTs.

Polyurethane is a class of polymers characterized by their substantial tensile strength and high melting points which enables them to be extremely durable. Despite its xenobiotic origin, polyure-thane has been found susceptible to biodegradation by microorgan-isms. The main object of this research was to investigate polyurethane degradation by the bacterium isolated from decayed teak wood (Tec-tona grandis Linn. f.). Polyurethane degrading bacteria were isolated using selective medium in the form of LB (Luria Bertani) with the ad-dition of 0.3% Impranil. Bacterial biodegradation activities shown by the changes of polyurethane structure analyzed by FT-IR spectrosco-py. The bacterial identification was carried out based on observations on the morphological characteristics of the colonies, cell morphology and sequences of 16S rRNA encoding genes. One of the potential iso-late that successfully isolated was K9, which demonstrates the disap-pearance of the 1735/cm peak of the characteris...

The study reports a simple and highly selective spectrofluorometric method for trace determination and speciation of chromium(iii & vi) species in water using 10-(3-dimethylaminopropyl) phenothiazine hydrochloride, namely, promazine hydrochloride (PMH) as a fluorescence tagging reagent.

Abstract The reaction of chlorochromate anion (CrO3Cl−) with rhodamine 6G hydrochloride dye (RG+) results in the formation of complex ion associate [RG+·CrO3Cl−] in non-aqueous medium. This study aimed to use t-octylphenoxypolyethoxyethanol polymer (Triton X-100) in [RG+·CrO3Cl]org extraction system to enhance the sensitivity of Cr(VI) under the optimized conditions. The produced highly electron deficient system in the binary complex ion associate [RG+·CrO3Cl] of Cr(VI) transforms into an adduct [(CrO3Cl−·RG+)·TX-100·nS]org in the presence of Triton X-100 (TX-100). This transformation enhanced the analytical response of the produced adduct specie in the organic phase by over 75%. The adduct formation via ether oxygen of TX-100 and the possible existence of H-bonding between NH of RG+ and ether oxygen of TX-100 are directly related to the increase in the molar absorptivity and this phenomenon was monitored by UV–Vis spectrophotometric measurement at λmax = 534 nm. The current study discusses the role of different surfactants and its influence on the extraction of Cr(III) & Cr(VI) species. A detailed proposed mechanism, structure, stoichiometry, and extraction equilibria for the produced adduct is presented. Cr(III) species after oxidation with H2O2 in KOH media were also determined by the proposed procedure. At optimal conditions, the method exhibited a wide linear range 0.0245–1.5 μg mL−1 with detection and quantification limits of 0.0073 μg mL−1 and 0.025 μg mL−1, respectively. This enhancement principle in the extraction systems could be extended to other class of surfactants and/or nano materials.

Leishmania major is the causative agent of cutaneous leishmaniasis (CL). No human vaccine is available for CL and current drug regimens present several drawbacks such as emerging resistance, severe toxicity, medium effectiveness, and/or high cost. Thus, the need for better treatment options against CL is a priority. In the present study, we validate the enzyme methionine aminopeptidase-1 (MetAP1), a metalloprotease that catalyzes the removal of N-terminal methionine from peptides and proteins, as a chemotherapeutic target against CL infection. The in vitro antileishmanial activity of eight novel MetAP1 inhibitors (OJT001-OJT008) were investigated. Three compounds OJT006, OJT007, and OJT008 demonstrated potent anti-proliferative effect in macrophages infected with L. major amastigotes and promastigotes at submicromolar concentrations, with no cytotoxicity against host cells. Importantly, the leishmanicidal effect was diminished by almost 10-fold in transgenic L. major promastigotes o...