In rapid prototyping, such as SLA (stereolithography apparatus) and FDM (fused deposition modelling), the orientation of the part during fabrication is critical as it can affect part accuracy, reduce the production time, and minimize the requirement for supports and, thus, the cost of building the model. Presents a multi-objective approach for determining the optimal part-building orientation. Considers different objectives such as part accuracy and building time. Objective functions have been developed based on known sources of errors affecting part accuracy and the requirements of good orientations during the building of a model. The objective functions employ weights assigned to various surface types affecting part accuracy. The primary objective is to attain the specified accuracy achievable with the process. The secondary objective is to minimize the building time. Gives examples to illustrate the algorithm for deriving the optimal orientation which can assure better part quality and higher building efficiency.

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High-quality Ni-doped ZnO thin films of single phase with preferred c-axis growth orientation were formed on Si (100) substrates by pulsed-laser deposition at room temperature. The films exhibited room-temperature ferromagnetic behaviors with saturation magnetic moment per Ni atom of 0.37μB,0.26μB,0.25μB and 0.21μB for the Ni concentration of 1, 3, 5, and 7 at. %, respectively. The decrease of ferromagnetism with doping concentration demonstrates that ferromagnetism observed at room temperature is an intrinsic property of Ni–ZnO thin films, not from any secondary phase.

Nerve growth factor (NGF) is involved in nerve sprouting, hyper-innervation, angiogenesis, anti-apoptosis, and preservation of cardiac function after myocardial infarction (MI). Positively modulating NGF expression may represent a novel pharmacological strategy to improve post-infarction prognosis. In this study, lentivirus encoding NGF short interfering RNA (siRNA) was prepared, and MI was modeled in the rat using left anterior descending coronary artery ligation. Rats were randomly grouped to receive intramyocardial injection of lentiviral solution containing NGF-siRNA (n = 19, MI-SiNGF group), lentiviral solution containing empty vector (n = 18, MI-GFP group) or 0.9% NaCl solution (n = 18, MI-control group), or to receive thoracotomy and pericardiotomy (n = 17, sham-operated group). At 1, 2, 4, and 8 wk after transduction, rats in the MI-control group had higher levels of NGF mRNA and protein than those in the sham-operated group, rats in the MI-GFP group showed similar levels as the MI-control group, and rats in the MI-SiNGF group had lower levels compared to the MI-GFP group, indicating that MI model was successfully established and NGF siRNA effectively inhibited the expression of NGF. At 8 wk, echocardiographic and hemodynamic studies revealed a more severe cardiac dysfunction in the MI-siRNA group compared to the MI-GFP group. Moreover, rats in the MI-siRNA group had lower mRNA and protein expression levels of tyrosine hydroxylase (TH) and growth-associated protein 43-positive nerve fibers (GAP-43) at both the infarcted border and within the non-infarcted left ventricles (LV). NGF silencing also reduced the vascular endothelial growth factor (VEGF) expression and decreased the arteriolar and capillary densities at the infarcted border compared to the MI-GFP group. Histological analysis indicated a large infarcted size in the MI-SiNGF group. These findings suggested that endogenous NGF silencing attenuated sympathetic nerve sprouting and angiogenesis, enlarged the infarct size, aggravated cardiac dysfunction, and potentially contributed to an unfavorable prognosis after MI.