Proteomics and Detection of Uromodulin in First-time Renal Calculi Patients and Recurrent Renal Calculi Patients

Renal calculi disease or known as kidney stone disease is the most common urological disorder in both men and women, although it is more prevalent in men. The lifetime chance for an individual to develop renal calculi is ~10% whereas the risk of recurrence in a 10-year period is 74%. Therefore, a diagnostic tool for screening or detecting renal calculi is greatly needed. In this study, we analyze urinary protein profiles from patients with renal calculi for the first time (RC), healthy subjects (HS), and patients with recurrent renal calculi (RRC) to identify a biomarker for detecting the disease. Urinary proteins were isolated by salt precipitation and the proteins resolved by SDS-PAGE. Target proteins were analyzed with LC/MS/MS. Thirty-two proteins were identified from healthy subjects and patients. Uromodulin was the most abundant urinary protein in HS but was a very faint band if detected at all from those that formed renal calculi for the first time (p < 0.05). Yet the excreted levels of urinary uromodulin in RRC were similar to those of the HS suggesting that uromodulin is a reliable biomarker for only RC. In addition, a few immunoglobulins that were commonly found in the urine of both RC and RRC, which include Ig alpha heavy chain 1, Ig gamma-2 c region, Ig gamma-3 heavy chain disease protein, Ig heavy chain variable region, Ig heavy constant region gamma 4, and Ig heavy chain. Ig heavy chain Fab frag and antibody a5b7 chain B may serve as potential biomarkers for renal calculi disease.     

The generation of ground-state structures and electronic properties of ternary AlkTilNim clusters (k + l + m = 4) from a two-stage density functional theory global searching approach

Structural and electronic properties of ternary clusters Al_kTi_lNi_m, where k, l, and m are integers and k + l + m = 4 , are investigated. These clusters are generated and studied by performing a two-stage density functional theory (DFT) calculations using the Slater, Vosko, Wilks, and Nusair (SVWN) and Becke three-parameter, Lee-Yang-Parr (B3LYP) functional exchange correlations. In the first stage, an unbiased global search algorithm coupled with a DFT code with a light exchange-correlation and smaller basis sets are used to generate the lowest energy cluster structures. It is then followed by further optimization using another round of DFT calculation with heavy exchanged correlations and large basis set. Electronic properties of the structures obtained via the two-stage procedure are then studied via DFT calculations. The results are illustrated in the form of ternary diagram. Our DFT calculations find that the stability of the cluster increases with the increase in the number of nickel atoms inside the clusters. Our findings provide new insight into the ternary metallic cluster through the structure, stability, chemical order, and electronic properties studies.     

Pressure drop and friction factor of steady and oscillating flows in open-cell porous media

Open-cell metal foams are often used in heat exchangers and absorption equipment because they exhibit large specific surface area and present tortuous coolant flow paths. However, published research works on the characteristics of fluid flow in metal foams are relatively scarce, especially for the flow oscillation condition. The present experimental investigation attempts to uncover the behavior of steady and oscillating flows through metal foams with a tetrakaidecahedron structure. In the experiments, steady flow was supplied by an auto-balance compressor and flow oscillation was provided by an oscillating flow generator. The pressure drop and velocity were measured by the differential pressure transducer and hot-wire sensor, respectively. The friction factor of steady flow in metal foam channel was analyzed through the permeability and inertia coefficient of the porous medium. The results show that flow resistance in the metal foams increases with increasing form coefficient and decreasing permeability. The empirical equation obtained by the present study indicates that the maximum friction factor of oscillating flow through the tested aluminum foams with specific structure is governed by the hydraulic ligament diameter-based kinetic Reynolds number and the dimensionless flow amplitude.     

pH responsive adhesion of phospholipid vesicle on poly(acrylic acid) cushion grafted to poly(ethylene terephthalate) surface

Polymer-supported lipid bilayer is a key enabling technology for the design and fabrication of novel biomimetic devices. To date, the physical driving force underlying the formation of polymer-supported lipid bilayer remains to be determined. In this study, the interaction between dipalmitoylphosphocholine (DPPC) vesicle and poly(ethylene terephthalate) [PET] surface with or without grafted poly(acrylic acid) [PAA] layer is examined with several biophysical techniques. First, vesicle deformation analysis shows that the geometry of adherent vesicle on either plain PET or PAA-grafted PET surface is best described by a truncated sphere model. At neutral pH, the degree of deformation and adhesion energy are unaltered by the grafted polymerization of acrylic acid on PET surface. Interestingly, the average magnitude of adhesion energy is increased by 185% and −43% on PAA-grated PET and plain PET surface, respectively, towards an increase of pH at room temperature. Our results demonstrate the possibility of tuning the adhesive interaction between vesicle and polymer cushion through the control of polyelectrolyte ionization on the solid support.     

The zwitterion effect in proton exchange membranes as synthesised by polymerisation of bicontinuous microemulsions

The bicontinuous microemulsions consisting of a polymerisable zwitterionic surfactant 3-((11-acryloyloxyundecyl)imidazolyl) propyl sulfonate (AIPS) and other monomers can be cross-polymerised to form good proton conductive membranes.     

The Effect of Temperature on the Operation of Quantum Well Laser: A Simulation Study Based on Three-Level Rate Equations

A temperature-dependent quantum well laser equivalent circuit model based on three-level rate equations is presented. The model is simulated using an ORCAD PSPICE circuit simulator. The characteristic properties such as threshold current, delay, and frequency response are simulated and compared with the available results. Included are temperature effect, leakage current, and heat dissipation effect on the chip. Threshold current increases, whereas turn on delay and optical output decrease with increasing temperature. An increase in temperature also reduces the operating frequency and resonance peak shifts to higher frequency. It is also observed that the modulation response of a QW laser with shorter separate confinement heterostructure region is more sensitive to the temperature variation.     

On the analysis of low quality flow boiling

A generalized analytical treatment of dimensionless equations describing turbulent forced convection and saturated nucleate boiling heat transfer leads to a new flow boiling relationship. This relationship yields a two-phase Nusselt number in terms of dimensionless parameters of the system and includes the effects of voidage and the suppression of boiling caused by the flow. It is applicable to geometries such as flow over tube bundles and flat plates in addition to the more commonly studies case of flow in tubes.The relationship is shown to correlate well the existing data on water over a wide range of conditions. A single experimentally determined factor is required and this factor is found for water and tentatively for Refrigerant 113 and cyclohexane.