Advanced Materials Research Vol. 749

Abstract: The SCID mouse (severe combined immunodeficiency mouse) has been used as a small animal model in the analysis of human pathophysiology and preclinical experiment for many years. As the most difficult challenge faced in the research of AIDS, chronic hepatitis B and chronic hepatitis C is the lack of appropriate small animal model, researchers have always attempted to develop a series of mouse models based on the improvements of the SCID mouse. This review focuses on the developments and applications of such SCID mouse models in three types of the above chronic infectious diseases.

Abstract: Lower alcohol-tolerant lipases have shown potential application for synthesis of biodiesel. An Arthrobacter strain producing a lipase with lower alcohol-stability was isolated from soils. The crude lipase had stability in the presence of methanol and ethanol. 78% and 85% of the original activity was retained after incubation for 48h in methanol and ethanol at the concentration of 50%.

Abstract: Objective: To investigate the correlation among CD4⁺CD25⁺ Treg cell frequency, CTLA-4 expression level in the peripheral blood mononuclear cells (PBMC), and disease progression of HIV/AIDS patents. Methods: Fifty HIV/AIDS-positive samples were confirmed by both Zhejiang Provincial and Hangzhou Center for Disease Control and Prevention. Ten samples of healthy volunteers were randomly selected as controls. Immune cells were counted using a flow cytometer (FACS), and the expression level of CTLA-4 mRNA analyzed using RT-PCR. Results: CD4⁺CD25⁺ Treg cells in PBMC of HIV/AIDS patients were markedly higher than those of healthy volunteers£ ̈P = 0.04j, and CTLA-4 mRNA was highly expressed in the CD4⁺CD25⁺ Treg subpopulation (P = 0.002), compared to healthy adults as well as AIDS patients treated with HAART. Conclusion: CTLA-4 expressed on CD4⁺CD25⁺ Treg cells can be a specific marker of the progression of HIV/AIDS, and the inhibitory receptor may play an important role in the regulation and pathogenesis of HIV/AIDS.

Abstract: Loop-mediated isothermal amplification (LAMP) allowed rapid amplification of nucleic acids under isothermal conditions. It can be combined with a chemosensor for much more efficient, field-friendly detection of Mycobacterium tuberculosis complex. In this report, LAMP was performed at 65 °C for 10 min, followed by a rapid reaction of DNA amplification by-product, pyrophosphate ion, with chemosensor resulted in red disappearance. The detection limit of Mycobacterium tuberculosis complex by LAMP-Chemosensor was 3-5 copies, and the total assay time including 10 min for rapid DNA extraction was approximately 30 min. Data on naturally contaminated raw milk samples indicated that the LAMP method was highly specific and sensitive, giving 100% concordance with Real-time PCR. The results showed that the LAMP-Chemosensor method had the advantages of better sensitivity and speed and less dependence on equipment than the standard (PCR) for specifically detecting low levels of Mycobacterium tuberculosis complex DNA, and this can be useful in the field as a routine diagnostic tool.

Abstract: This paper proposed a fast algorithm to detect anterior chamber angle points and measure central corneal thickness for anterior chamber optical coherence tomography (OCT) images automatically. This algorithm uses biggest connected regions method to get the anterior chamber region, and detects the anterior chamber angle points (ACAPs) in this region firstly. Secondly, the algorithm uses ACAPs to obtain the real position of central cornea then measures the central corneal thickness of anterior chamber. The proposed algorithm was tested on 74 anterior chamber OCT images and provided accurate measurements in about 90 milliseconds.

Abstract: This topic is considered to modify the fast-growing Poplar to improve the properties, in order to fully meet the performance requirements for the structural material. This study aims to improve the dimensional stability and some other mechanical properties through impregnated with the low-molecular-weight PF resin. Through design orthogonal test in different mole ratio of Formaldehyde and Phenol, different amount of NaOH and PVA, we make PF resin to impregnate Poplar and pressing into laminated timber to measure bonding strength, MOR, MOE. The study indicated that: the optimum conditions of the low molecular weight PF resin for modify Poplar are: mole ratio of Formaldehyde and Phenol is 2.4, mole ratio of NaOH and phenol is 0.05, amount of PVA is 3% of the phenol. Under this condition Poplar specimen got the biggest increase in various properties and it can satisfy the requirements of the outdoor wood structure.

Abstract: The rate of gas diffusion is inversely proportional to the gas molecule diameter; hydrogen gas molecular has smaller diameter and thus it has a greater diffusion coefficient than methane. Results of laboratory studies shown that when a gas mixture consisting of H₂/CH₄ = 30:70 is treated in a Hollow-fiber member under 5 kg/cm², the hydrogen concentration is raised from 30 mol% to 71 mol%. If the Hollow-fiber member is re-arranged in series connection without controlling the operating pressure (free permeation), the recovered hydrogen concentration can be as high as 88 mol%. Additionally, using H₂/CH₄ = 50:50 as the influent gas mixture and controlling the influent pressure at 5 kg/cm², the resulting hydrogen concentration can be raised from 50 mol% to 92 mol%, if the Hollow-fiber member is re-arranged in series connection without controlling the permeating pressure (free permeation), the recovered hydrogen concentration can reach 94 mol%. Therefore, Hollow-fiber member can be implemented to recover hydrogen gas from the hydrogen-rich petrochemical process tail gas at low pressure; the recovered hydrogen can be further utilized with higher add-on value. This hydrogen-recovery method has the advantage of low capital cost, simple to operate and small energy consumption.

Abstract: The interaction between natural pheophorbide (a superior photosensitizer) and bovine serum albumin (BSA) in physiological condition is investigated by means of UV-Vis, fluorescence and synchronous fluorescence spectra so as to provide the basis for clinical use. Natural pheophorbide was isolated from silkworm excrement. BSA in pH 7.4 Tris buffer mixed with different concentration of pheophorbide was kept at certain temperature for 3 h or under illumination by laser at 630 nm for 20 min. UV-Vis absorption of BSA was enhanced and its fluorescence was quenched by pheophorbide. Illumination of laser at 630 nm intensified the quenching. The mechanism is deemed as mainly static quenching. The binding constants K_a at 300, 310, 320 K are separately 6.93×10¹²,7.40×10¹²,6.82×10¹² L/mol/s respectively. Number of binding sites n is 1; the binding distance R is 3.70 nm, and that suggests non-radiation energy transfer from BSA to pheophorbide. The thermodynamic parameters of the binding reaction are H=36.7 kJ/mol, S=213 J/mol/K, and G negative value, and indicates that hydrophobic force plays a predominant role in the process, and it is a spontaneous interaction. Synchronous fluorescence spectra show that pheophorbide mainly interacts with tryptophan residue of BSA and leads to the promotion of hydrophobic force. Pheophorbide can bind to serum protein and be transported in vivo, makes no destruction to molecular structure of serum protein, but causes its conformational alteration.

Abstract: The aim of the experimental study is to determine chemical properties of substituted and blended cement contained marble and brick powders to provide efficacy for the economical and the environmental aspect. Marble and brick powders, CEM I 42.5N cement and clinker were used as materials in the study. Substituted cements were prepared with the addition of cement for marble or brick powder at the ratios of % 6, 20, 21, 35. Blended cements were mixed the addition of cement clinker for marble or brick powder at the ratios of % 6, 20, 21, 35. And CEM I 42.5N cements were also chosen as Reference cement. Results show that marble and brick powders can prevalently add as substitute or blend materials to cement to prevent it detrimental chemicals like alkali-silica reaction.

Abstract: The paper was incisive about marble and brick wastes problem. In Turkey, annual approximately 2 592 000 t marble waste and 3 800 000 t brick waste are turn out while marble and brick manufactures. These wastes are stored agrarian land so they are contaminated environment and terrain. Chemical, physical, and pozzolanic properties of the marble and brick powders described characteristic properties were helped whether to use them as mineralogical substitute or blend in cement or not. The aim of this study is to establish characteristic properties of marble and brick powders. Tekmar Marble Factory's marble powder and Kaman Brick Factory's brick powder were used as materials. Characteristic properties of the marble and brick powders were lie down via standard experiment methods known literature. Results show that the powders are compatible to add cement clinker or to substitute for cement to improve their properties.