Effect of laser loop on surface morphology of copper substrate and wettability of solder joint

The effect of different laser loop parameter on the geometry of micro-groove pattern on copper substrate and its effect on the wettability was investigated. The micro-grooves pattern was fabricated on the copper surface through laser surface texturing process. 3D measuring laser microscope and contact angle measurement test was conducted to measure the geometry of the micro-grooves pattern and wettability of the solder joint respectively. The results showed that the improvement in laser loop parameter increased the depth of the micro-grooves due to the more exposed time which allows more material ablation. It also showed that the contact angle of textured substrate is smaller than the untextured substrate which results in better wettability

Effectiveness of dimple microtextured copper substrate on performance of Sn-0.7Cu solder alloy

This paper elucidates the influence of dimple-microtextured copper substrate on the performance of Sn-0.7Cu solder alloy. A dimple with a diameter of 50 µm was produced by varying the dimple depth using different laser scanning repetitions, while the dimple spacing was fixed for each sample at 100 µm. The dimple-microtextured copper substrate was joined with Sn-0.7Cu solder alloy using the reflow soldering process. The solder joints’ wettability, microstructure, and growth of its intermetallic compound (IMC) layer were analysed to determine the influence of the dimple-microtextured copper substrate on the performance of the Sn-0.7Cu solder alloy. It was observed that increasing laser scan repetitions increased the dimples’ depth, resulting in higher surface roughness. In terms of soldering performance, it was seen that the solder joints’ average contact angle decreased with increasing dimple depth, while the average IMC thickness increased as the dimple depth increased. The copper element was more evenly distributed for the dimple-micro-textured copper substrate than its non-textured counterpart

Application of cDNA microarray in halal research

cDNA Microarray is a powerful tool of technology to study gene expression. The technique allows simultaneous analysis on thousands of gene expression in a single assay compared to traditional molecular biology tools which generally allow only single gene expression at a time. This high throughput technology has been applied in diversified researches such as in toxicology, human nutrition, environmental, clinical diagnoses and many more. To the best of our knowledge, the technique has not been widely applied in Halal research although studies on the effects of consumption of alcohol and toxic compounds to human from the medical perspective and safety have been reported. This review sets to look at the feasibility of the cDNA Microarray technology in Halal research with a case study on the effects of alcohol intake on gene expression as precedent of the promising technology in deciphering the effects of Halal versus Haram components particularly from animals to human cells

In vitro study on collagen application in wound healing: a systematic review

Collagen is key component of extracellular matrix for human and animals. It can be extracted and applied for various field especially in tissue engineering as main component for wound healing. Collagen especially type I collagen is used in skin regeneration process due to its high compatibility with donor site and low antigenicity besides of having suitable properties for wound healing like high cell proliferation and adhesion. However, the usage of collagen alone would not give maximum wound healing since collagen degrades faster, has poor structure for a scaffold and attracts bacteria due to high moisture content. Therefore, to produce a good collagen scaffold, it must be incorporated with functional biomaterials to enhance the characteristic of the collagen and fabricated for a better scaffold structure. The objective of this systematic review is to summarize the relevant literature for in vitro study on collagen application in wound healing by focusing on the source of collagen, biomaterials and fabrication methods used in making collagen scaffold. Three databases were searched; PubMed, Scopus and Science Direct. Keywords used were: collagen, recombinant collagen, collagen scaffold, application and wound healing. A total of 1105 were articles screened but only 50 articles were suitable and were further reviewed. Collagen in wound healing study has versatility in terms of the source of collagen used, the biomaterials combined with the collagen to make an enhanced scaffold, and the fabrication methods to create a desirable structure of collagen scaffold

Cloning, expression and purification of collagen-like protein from Methylobacteria sp. 4-46 as alternative substance for collagen-based industries

Nowadays, collagen is widely introduced into oral and topical relief cosmeceutical products and is applied in the pharmaceutical industry in the form of hydrogels and collagenated scaffolds. However, due to the source of collagen in the market, it is a big concern for the Muslim community in terms of Halalan and Toyyiban since it is mainly extracted from mammals, especially porcine (Haram) and it raises health issues of animal-to-human disease transmission such as mad cow disease, swine, and avian flu. Collagen from bacteria would be the best alternative for halal and non-animal collagen. In this study, the bacterial collagen that produces collagen-like protein (CLP) of Methylobacteria sp. 4-46 was synthetically synthesized by Genscript. The CLPM4-46 in pUC57 was transformed into Escherichia coli DH5α and digested with BamHI/NdeI. The digested product (CLPM4-46, 1.04kbp) was successfully ligated with pCold II plasmid (4.39kbp) and transformed into E. coli BL21 (DE3). The ligated CLP gene was expressed using M9 minimal media. The protein expressed by the recombinant E. coli was measured with the Bradford Assay and SDS-PAGE where the size of the protein was 34.9k Da, and the CLP recombinant protein was purified using Fast Protein Liquid Chromatography and the collagen was measured using Enzyfluo™ Collagen Assa

Effect of LST parameter on surface morphology of modified copper substrates

This study aimed to investigate the effect of laser surface texturing (LST) parameter on the surface morphology of copper substrate. The results of different loop number (L1 to L5) on the resolidified material of micro-dimpled surface modified copper substrate were examined. The micro-dimple with a diameter of 100 μm was produced via LST process by varying the dimple distance at 100 μm and 180 μm. The resolidified material that was formed after the surface texturing process was analysed using 3D measuring laser microscope. Based on the data collected, the dimple was successfully engraved on the copper substrate. The increasing number of loop increase the quantity of the melted material which lead to higher amount of resolidified material and surface roughness

Effectiveness of Dimple Microtextured Copper Substrate on Performance of Sn-0.7Cu Solder Alloy

This paper elucidates the influence of dimple-microtextured copper substrate on the performance of Sn-0.7Cu solder alloy. A dimple with a diameter of 50 µm was produced by varying the dimple depth using different laser scanning repetitions, while the dimple spacing was fixed for each sample at 100 µm. The dimple-microtextured copper substrate was joined with Sn-0.7Cu solder alloy using the reflow soldering process. The solder joints’ wettability, microstructure, and growth of its intermetallic compound (IMC) layer were analysed to determine the influence of the dimple-microtextured copper substrate on the performance of the Sn-0.7Cu solder alloy. It was observed that increasing laser scan repetitions increased the dimples’ depth, resulting in higher surface roughness. In terms of soldering performance, it was seen that the solder joints’ average contact angle decreased with increasing dimple depth, while the average IMC thickness increased as the dimple depth increased. The copper element was more evenly distributed for the dimple-micro-textured copper substrate than its non-textured counterpart