Extraction and characterization of collagen from the skin of Pterygoplichthys pardalis and its potential application in food industries

Food Science and Biotechnology - The primary objective of this study was to extract collagen from underutilized fish species owing to its cost effective nature and also its ability to address the...     

Drug and ion releasing tetracalcium phosphate based dual action cement for regenerative treatment of infected bone defects

Calcium phosphate cements (CPCs) are ideally suited for the local delivery of antibiotics in infected bone defects as they have multiple binding sites for loading various drugs. CPCs can also be substituted with ions such as Ag⁺, Zn²⁺, Mg²⁺, Sr²⁺, etc., to exhibit extended broad-spectrum antimicrobial activity. Strontium (Sr) in particular is known to enhance the new bone formation and decrease bone resorption. The current work aims to develop a dual action tetracalcium phosphate (TTCP) based cement which releases both the Sr²⁺ ion and ornidazole antibiotic drug for the treatment of bone infections. The TTCP with Sr²⁺ ion substitution was prepared by the solid state reaction method and it was used to form ornidazole loaded CPC. The ornidazole loaded cement prepared using 8?at% Sr substituted TTCP (8SCPC-O) showed complete hydroxyapatite (HA) formation in phosphate buffered solution at the end of 1 week. Fine needle-shaped HA crystals were observed in 8SCPC-O cement. In vitro drug release studies showed an accelerated ornidazole release from the 8SCPC-O sample when compared to samples without Sr substitution. Ornidazole releasing cements were found to be biocompatible with skeletal myoblast (L6) cells. Antibacterial activity of ornidazole releasing cement was evident from day 1 onwards against E. coli. The above results suggest 8SCPC-O as a good candidate for treating local bone infections.     

Fiber-optic miniature sensor for in situ temperature monitoring of curing composite material

This study proposes a fiber-optic temperature sensor with a single-mode fiber tip covered with a thermo-sensitive polymer resin. The temperature is sensed by measuring the Fresnel reflection from the optical fiber/polymer interface. Because the thermo-optic coefficients differ between the optical fiber and the polymer, the in situ temperature can be measured even in curing composite materials. In initial experiments, the proposed sensor successfully measured and recovered the temperature information. The measured sensor data were linearly correlated, with an R² exceeding 0.99. The standard deviation in the long-term measurements of constant temperature was 2.6%. The durability and stability of the sensor head material in long-term operation was validated by Fourier transform infrared spectroscopy and X-ray diffraction analysis. In further experiments, the suggested miniature temperature sensor obtained the internal temperatures of curing composite material over a wide range (30–110 °C).     

A Time to Kill: Targeting Apoptosis in Cancer

The process of apoptosis is essential for maintaining the physiologic balance between cell death and cell growth. This complex process is executed by two major pathways that participate in activating an executioner mechanism leading to chromatin disintegration and nuclear fragmentation. Dysregulation of these pathways often contributes to cancer development and resistance to cancer therapy. Here, we review the most recent discoveries in apoptosis regulation and possible mechanisms for resensitizing tumor cells to therapy.     

Thermoelectric properties of plasma sprayed of calcium cobaltite (Ca2Co2O5)

The thermoelectric properties of calcium cobaltite deposits produced by the plasma spray process are investigated from room-temperature to 873 K. Synthesis of Ca₃Co₂O₆ and Ca₂Co₂O₅ powders were prepared by the solid-state reaction from CaO and CoO_x starting powders. During their subsequent plasma spray Ca particles experience preferential evaporation within the plasma, resulting in a complex interplay among process conditions, stoichiometry, and resultant phases. The as-sprayed material predominantly contains amorphous and secondary phases. Upon annealing, the deposits show sensitivity to phase evolution and therefore thermoelectric properties. Through screening studies, optimal annealing conditions were identified which show a p-type Seebeck coefficient value of 180 μV K^?1, electrical conductivity of 1.09 × 10⁴ S m^?1, thermal conductivity of 1.16 W m^-1 K^-1 at 873 K. The resultant figure of merit value reached 0.266 for this combination of processing and thermal treatment and is in line with data reported from other techniques for this system.     

Rapid solidification and microstructure development during plasma spray deposition

Plasma spray processing is a well-established method for forming protective coatings and free-standing shapes from a wide range of alloys and ceramics. The process is complex, involving rapid melting and high-velocity impact deposition of powder particles. Due to the rapid solidification nature of the process, deposit evolution also is complex, commonly leading to ultrafine-grained and metastable microstruc-tures. The properties of a plasma-sprayed deposit are directly related to this complex microstructure. This paper examines the solidification dynamics and the resultant microstructures in an effort to estab-lish a processing/microstructure relationship. Existing models in the literature developed for splat coo-ling have been extended and applied for examining the rapid solidification process during plasma spraying. Microstructural features of the splats that are produced by individual impinging droplets are examined through scanning and transmission electron microscopy. The relation of dimensions and mor-phologies of these individual splats to the consolidated deposit microstructure is considered. In addition, the distinguishing features in the solidification and microstructural development between air plasma spraying and vacuum plasma spraying are explored, and a unified model is proposed for splat solidifica-tion and evolution of the microstructure.     

Robustness of discrete-time state feedback control systems

This paper presents stability robustness results for linear multivariable discrete-time systems with uncertainties. Robust stability of the full-state feedback linear quadratic regulator in the presence of perturbations of the system parameters is investigated. These results are based on recently developed bounds on structured perturbations of a stable linear discrete-time system. The paper applies these results to a paper-machine head box system example.     

Applying several soft computing techniques for prediction of bearing capacity of driven piles

Engineering with Computers - Pile as a type of foundation is a structure which can transfer heavy structural loads into the ground. Determination and proper prediction of pile bearing capacity are...