CHARACTERIZATION OF 3D-PRINTING FILAMENT WITH EXTRUDER MELTING TEMPERATURE VARIATION FOR BONE IMPLANT FROM KUPANG SHELL

<p><em>The number of bone damage in Indonesia continues to increase. Bone implant is one of the medical treatment methods performed on bone damage. Organic and non-organic materials can be used as bone implants. Non-organic materials are stronger, but not biocompatible, while organic materials are biocompatible, but brittle. The addition of polycaprolactone polymer (PCL) can increase the mechanical strength of 3D printing bone implant filaments. Extruder melting temperature is one of the factors that affect the quality of PCL-HAp filaments for bone implants. Studies related to temperature variations in PCL-HAp materials have not been widely studied. Therefore, it is necessary to characterize 3D printing filaments with variations in the melting temperature of the extruder as bone implants from mussel shells with temperature variables of 65^oC, 75^oC, and 85^oC. From this study, the optimum point was found at the melting extruder temperature of 75^oC with the results of a diameter of 1.810 and mechanical strength which showed an increase in tensile strength and Young's modulus of PCL-HAp composite in all variables compared to pure PCL. The SEM test showed a rough surface on the filaments that could increase the proliferation and adhesion of good cells for the growth of bone tissue.</em></p>

Morphology, thermal and mechanical properties of electrospun polyvinylidene/polyethylene glycol composite nanofibers as form-stabilized phase change materials

Polyvinylidene fluoride (PVDF)/polyethylene glycol (PEG) form-stabilized composite phase change nanofibers with various mass percentage of PEG1000 (with average molecular weight of 1000) loadings were fabricated by electrospinning technique, in which PEG was served as phase change material (PCM) and PVDF as the supporting matrix to afford a mechanically strong structure. Effect of PEG1000 content on nanofiber morphology, phase transition properties, thermal stability, thermal energy storage and release performance, and mechanical properties were studied experimentally. The results showed that the incorporation of PEG1000 improved the spinning solution viscosity and high mass fraction of PEG1000 in the nanofibers led to decreased fiber diameter and melting temperature, and higher latent heat of fusion. In addition, mechanical test revealed that the fracture elongation of the electrospun PVDF/PEG composite nanofibrous membranes were initially increased with unobvious tensile strength changes, while the value of the elongation would decrease, and the tensile strength increase as the mass ratio of PVDF/PEG lower to 1:1. Furthermore, the melting temperature and maximum latent heat for PVDF/PEG were determined from DSC measurement as 51.8 °C, and 73.3 J/g, when the mass radio of PVDF/PEG was 1:1 (w/w), which was suitable utilized for thermo-regulating textiles or in heat storage devices.

Impact of dynamic covalent chemistry and precise linker length on crystallization kinetics and morphology in ethylene vitrimers

Vitrimers, dynamic polymer networks with topology conserving exchange reactions, can lead to unusual evolution of the melting temperature and crystal structure of ethylene networks.

Hybridization of Oligonucleotide Probes in Aqueous Solutions: Washing in Buffers Containing Quaternary Ammonium Salts

In this protocol, hybridization is first performed in conventional aqueous solvents at a temperature well below the melting temperature, and the hybrids are then washed at higher stringency in buffers containing quaternary alkylammonium salts. TMACl is used with probes that are 14–50 nt in length, whereas TEACl is used with oligonucleotides that are 50–200 nt in length.

Calculation of parameters of elementary nanocrystals of liquid metals at melting temperature

Method of calculation and calculated values of parameters of elementary nanocrystals of liquid metals at melting temperature are given. It has been shown that radii of elementary nanocrystals are from 2 nm to 12 nm, and the number of atoms in each elementary nanocrystal varies from 2000 to 100000. This provides liquid metals with a high solidification rate and explains the abnormally high diffusion coefficient in liquid metals compared to solid metals.

Optimasi Analisis Melting Curve untuk Skrining Cepat dan Sensitif Mutasi V1016G pada Aedes aegypti Resisten Sintetik Piretroid dengan Reaksi Rantai Polimerase Spesifik Alel

Detection of V1016G mutation is important for identifying the mechanism of synthetic pyrethroid resistance in Aedes aegypti population. The previous method has described an allele specific polymerase chain reaction (AS-PCR) using conventional PCR to detect the mutation. Although the method has great differentiating power and reproducibility, faster and more sensitive genotyping method is essential to accurately detect the mutation. This study evaluate the used of SYBR® Green real-time PCR and melting curve analysis (MCA) to identify the V1016G mutation. The collection of homozygous 1016G, heterozygous, and wild type (1016 V) mosquitoes DNA genome was extracted using genomic DNA mini kit. The SsoAdvanced™ Universal SYBR® Green Supermix was used to identify alleles by real-time PCR followed melting curve analysis of the amplicons. Melting curve analysis produced reproducible results for the loci tested. The melting temperature was reached at 78.5 oC for homozygous 1016G mosquito and at 86 oC for wild type mosquito. Meanwhile, the heterozigous mosquito revealed two peaks of melting temperature at both 78.5 oC and 86 oC. These easily interpretable and distinguishable melting curve results were consistent with AS-PCR results obtained for the same alleles. The described MCA application for screening V1016G mutation is fast and widely accessible also could be implemented under field conditions