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91.
Venugopal J Low S Choon AT Sampath Kumar TS Ramakrishna S 《Journal of materials science. Materials in medicine》2008,19(5):2039-2046
Regeneration of fractured or diseased bones is the challenge faced by current technologies in tissue engineering. The major
solid components of human bone consist of collagen and hydroxyapatite. Collagen (Col) and hydroxyapatite (HA) have potential
in mimicking natural extracellular matrix and replacing diseased skeletal bones. More attention has been focused on HA because
of its crystallographic structure similar to inorganic compound found in natural bone and extensively investigated due to
its excellent biocompatibility, bioactivity and osteoconductivity properties. In the present study, electrospun nanofibrous
scaffolds are fabricated with collagen (80 mg/ml) and Col/HA (1:1). The diameter of the collagen nanofibers is around 265 ± 0.64 nm
and Col/HA nanofibers are 293 ± 1.45 nm. The crystalline HA (29 ± 7.5 nm) loaded into the collagen nanofibers are embedded
within nanofibrous matrix of the scaffolds. Osteoblasts cultured on both scaffolds and show insignificant level of proliferation
but mineralization was significantly (p < 0.001) increased to 56% in Col/HA nanofibrous scaffolds compared to collagen. Energy dispersive X-ray analysis (EDX) spectroscopy
results proved the presence of higher level of calcium and phosphorous in Col/HA nanocomposites than collagen nanofibrous
scaffolds grown osteoblasts. The results of the present study suggested that the designed electrospun nanofibrous scaffold
(Col/HA) have potential biomaterial for bone tissue engineering. 相似文献
92.
Compression testing of Ti-6Al-4V alloy has been carried out at temperatures between 303 K to 873 K. To prevent embrittlement due to atmospheric oxygen and nitrogen, the samples were given a glass coating, which also acts as a lubricant simultaneously. Dynamic Strain Aging was observed to occur in the temperature range of 600 K to 800 K. Below 600 K stresses were high. Warm working has to be done above 800 K but below 1163 K (0.6 Tm where Tm = 1940 K) which is the recrystallization temperature. Based on these conclusions, warm extrusion has been successfully carried out in the Materials Forming Laboratory of I.I.T., Madras, Chennai, India. 相似文献
93.
94.
95.
Ali M Chattopadhyay S Nag A Kumar A Sapra S Chakraborty S Sarma DD 《Nanotechnology》2007,18(7):075401
CdSeS nanocrystals with different bandgap energies have been synthesized by the colloidal method. The solution blend of blue-, green-?and red-emitting CdSeS nanocrystals, in appropriate proportions, showed strong white emission of different shades on excitation with a UV source. We observed that the CIE coordinate of the spectrum of a particular blend is independent of excitation wavelength. We also observed that the contribution of self-absorption in energy loss in the blend of CdSeS nanocrystals is not very significant. A white-light-emitting LED has been fabricated by coating a blend mixed with polymethylmethacrylate on a commercial UV-LED. 相似文献
96.
Pattern Analysis and Applications - 相似文献
97.
Pattern Analysis and Applications - 相似文献
98.
It is a widespread opinion among engineering faculty that undergraduates could be better prepared in mathematics when taking courses in their professional field of study. The lack of preparation in applying mathematical concepts may be due to the fact that examples from engineering disciplines are not widely used in mathematics courses. Most mathematics departments act as service departments to students majoring in various fields in addition to providing their own degree programs. As a result, it is not economically justifiable for them to custom tailor courses for customers from different disciplines. On the other hand, engineering has a distinct requirement of creatively applying mathematical concepts and principles to engineering problems studied in various courses. Some of the issues that must be addressed to ensure adequate preparation in the application of mathematics include: the mathematical competencies needed in engineering courses; which mathematics courses should cover such competencies; and what examples and problems related to students' major field should be developed and taught in these courses to enhance understanding and application of these concepts. The goal of this paper is not to resolve these issues, but rather to develop a conceptual framework for determining the answers using the Quality Function Deployment approach. 相似文献
99.
Ashang Luwang Laiva Jayarama Reddy Venugopal Sreepathy Sridhar Bhargavi Rangarajan Balchandar Navaneethan Seeram Ramakrishna 《Polymer》2014
Reproducible buckled and porous sub-micron diameter polycaprolactone (PCL) fibers were produced by simple electrospinning process for biomedical applications. In this study, six types of solvent combinations with different vapor pressures were used to study the effect of phase separation on the morphology of electrospun fibers. The fiber morphology, Infrared spectroscopy, water contact angle and tensile test were performed to study the material properties. It is evident that the fiber morphology was affected by solvent combinations used for the fabrication of sub-micron fibers. The solution viscosity, the collecting distance and the type of solvent combination used could be an optimum parameter for the generation of porous-buckled fibers with narrow pore size distribution. The simplicity of the set-up is the immense advantage for producing buckled and porous elastomeric fibers for tissue engineering applications. All the fibers were spun on a motionless collector plate to study the properties of fibers. The combination of surface pores with the buckled pattern could be of great importance in the field of biomedical engineering. 相似文献
100.
Md Ataul Islam V. P. Subramanyam Rallabandi Sameer Mohammed Sridhar Srinivasan Sathishkumar Natarajan Dawood Babu Dudekula Junhyung Park 《International journal of molecular sciences》2021,22(20)
Cardiovascular diseases (CDs) are a major concern in the human race and one of the leading causes of death worldwide. β-Adrenergic receptors (β1-AR and β2-AR) play a crucial role in the overall regulation of cardiac function. In the present study, structure-based virtual screening, machine learning (ML), and a ligand-based similarity search were conducted for the PubChem database against both β1- and β2-AR. Initially, all docked molecules were screened using the threshold binding energy value. Molecules with a better binding affinity were further used for segregation as active and inactive through ML. The pharmacokinetic assessment was carried out on molecules retained in the above step. Further, similarity searching of the ChEMBL and DrugBank databases was performed. From detailed analysis of the above data, four compounds for each of β1- and β2-AR were found to be promising in nature. A number of critical ligand-binding amino acids formed potential hydrogen bonds and hydrophobic interactions. Finally, a molecular dynamics (MD) simulation study of each molecule bound with the respective target was performed. A number of parameters obtained from the MD simulation trajectories were calculated and substantiated the stability between the protein-ligand complex. Hence, it can be postulated that the final molecules might be crucial for CDs subjected to experimental validation. 相似文献