Expression and loss of the transferrin receptor in growing and differentiating HD3 cells

During induced differentiation and maturation of HD3 cells (a chicken erythroblast cell line infected with a temperature-sensitive mutant of the avian erythroblastosis virus), the levels of transferrin receptor (TFR) and nucleoside transporter increase. Both these activities increase before elevated levels of hemoglobin are detected. Shortly after induction, as cellular TFR levels rise, a native-size TFR is detected in the cell-free culture medium, associated with an exosome fraction (100,000 xg pellet). Nucleoside transporter (measured as NBMPR-binding activity) is not increased in this pellet with induction. Previous studies have suggested that exosome formation in peripheral reticulocytes may be a significant route for loss of specific membrane proteins (Johnstone et al., 1991). Although the present experiments in HD3 cells do not address the quantitative importance of exosome formation, the studies suggest that exosome formation is an early event in commitment to the red cell lineage and is not a phenomenon restricted to the terminal stages of red cell maturation.     

Solution of some boundary value problems in applied mechanics by the collocation least square method

The conventional simple but crude method of collocation is greatly improved by a least square augmentation. Simplicity in application and good accuracy of the proposed collocation least square scheme is demonstrated by the solution of some complex problems in applied mechanics.Example solutions of such problems include the linear and nonlinear analyses of isotropic plates, orthotropic plates and plates on elastic foundations. Numerical and graphical results are presented and compared with existing solutions. For the problems considered herein, the present method proves to be much less laborious than other numerical methods frequently employed by previous investigators.     

Status and prospects of hybrid and injection-locked TEA CO2lasers for LIDAR and nonlinear optics applications

The current status of hybrid and injection-locked single-mode TEA CO2laser systems is examined in relation to two important applications. It is argued that the operational characteristics of injection-locked systems are particularly well-suited for LIDAR applications and that the properties of hybrid devices impose a strong bias toward nonlinear optics applications, in particular, optical signal processing research.     

Scanning electron microscopy studies on tear fracture of natural rubber

Tear fracture surfaces of peroxide- and sulphur-cured natural rubber vulcanizates, both unfilled and filled, have been studied using scanning electron microscope. Peroxide-cured unfilled vulcanizate shows stick-slip tear whereas the HAF black-filled vulcanizate gives rise to a layered fracture surface. Tear branching, observed in the unfilled sulphur-cured vulcanizate changes to a high level of tear deviation resulting in a rough surface, with the addition of HAF black. FT black improves tear resistance only slightly and the fracture surface appears comparatively smooth. The low level of polymer-filler interaction in clay filled vulcanizates causes the filler agglomerates to come out of the matrix during the test thus decreasing tear resistance and giving rise to a pitted surface.     

Primary oxalosis with myocardial involvement and heart block

An unusual case is described of primary oxalosis with renal failure and cardiac involvement with complete heart block. Although cardiac involvement rarely occurs, it nevertheless requires evaluation because of the therapeutic implications.     

Improving Infection Resistance in Tissue Engineered Scaffolds for Tensile Applications Using Vancomycin-Embedded Melt Electrowritten Scaffolds

It is important to consider mechanical, biological, and antibacterial properties of scaffolds when used for tissue engineering applications. This study presents a method to create complex “wavy” architecture polycaprolactone (PCL) scaffolds toward the development of tissue engineered ligament and tendon tissue substitutes, fabricated using melt electrowriting (MEW) and loaded with vancomycin (5, 10, and 25% w/w). Scaffolds are characterized for both mechanical and biological properties. Loading PCL scaffolds with vancomycin with modified solvent evaporation technique achieves a high loading efficiency of maximum 18% w/w and high encapsulation efficiency with over 89%. Vancomycin loaded PCL scaffolds with all three doses (5, 10, and 25% w/w) display antibacterial activity against Gram-positive Staphylococcus aureus (S. aureus) up to 14 days of release. Initial burst followed by a sustained release is observed on all three vancomycin loaded scaffolds for up to 28 days. Importantly, in addition to antibacterial properties, vancomycin-loaded PCL scaffolds also display improved mechanical properties compared to traditional crosshatch design MEW scaffolds and are noncytotoxic at all concentrations as demonstrated by live-dead staining, cell attachment and proliferation assays indicating its potential as an effective treatment option for tissue regeneration in rotator cuff injuries or other tissues undergoing tensile biomechanical loading.     

Impact of Drain Underlap and High Bandgap Strip on Cylindrical Gate All Around Tunnel FET and its Influence on Analog/RF Performance

Silicon - This paper comprises of design and analysis of novel gate all around (GAA) cylindrical tunnel field effect transistor (TFET) using technology computer aided designing (TCAD) tool. The...     

On the toughening of unsaturated polyester resins using nadimide end-functionalized polyether telechelics

Copoly-propylene glycol (terephthalate–maleate) based unsaturated polyester resin (UPER) was modified with nadimide end-capped polyether telechelics namely, polypropylene glycol (PPG with molecular weight 2000, 1000, 400 g/mol), polytetramethylene oxide (PTMO with molecular weight 2000 g/mol) and polyethylene glycol (PEG with molecular weight 2000 g/mol) (NPPG/NPTMO/NPEG). The telechelic NPPG/NPTMO/NPEG were synthesized from the corresponding polyols (hydroxy telechelics) by reaction with 4-nadimido benzoyl chloride. These derivatives were characterized by chemical and spectral methods. Blends of UPER with varying amounts of NPPG/NPTMO/NPEG were prepared. Blending boosted the cohesive energy through enhanced crosslinking as reflected in the gel content of the cured matrices done in separate studies. It increased the fracture characteristics tremendously. The addition of 2.5 phr of the nadimide end functional polyether gave the maximum toughness. The crosslink density showed an initial increase on blending, but further addition of the telechelics did not make any change. The properties of the prepared blends were compared with maleimide end-capped polyether toughened UPE resins. It was concluded that the toughening effect of the polyether additive depends not only on its concentration but also on its distribution in the matrix as dictated by its reactivity ratio with styrene. The high reactivity of the nadimide groups did not create an ambiance good enough to get an acceptable distribution of the polyether segments conducive for a tough matrix. Whereas the maleimide end-capped polyether provides better toughening efficiency.     

The onset of Rayleigh–Bénard convection and heat transfer under two-frequency rotation modulation

The impact of 16 combinations of sinusoidal (sine) and nonsinusoidal (square, triangular, and sawtooth) time-periodic Coriolis force (rotation modulation) on Rayleigh–Bénard convection in a Newtonian liquid is studied in this paper. This consideration is made to capture the possible effects of two-frequency rotation modulation on stability, that is, the onset of convection and the simultaneous amount of heat transfer in the system. The Venezian approach has been asserted on the linearized Lorenz model to derive the correction Rayleigh number as a function of the two frequencies. The Lorenz model with nonlinearities is evaluated numerically to assess the quantity of heat transfer in the system. The present study states that in comparison with existing studies of no-modulation and single-frequency rotation modulation, two-frequency rotation modulation yields higher stability bounds and thus diminishes the heat transfer. Heat transfer is found to be enhanced by a pair of coprime integers associated with the harmonics in the system.