Temperature Controlled 3D Bio-printing Using Bio-polymeric Ink

Bio-Printing 3D organs, tissues & scaffolds is advancing everyday, with various methods being introduces to mimic a perfect working organ or tissue which can be functional at the same time. We have developed a method to print bio-polymer in liquid state using them as bio-inks to prints scaffolds, while maintaining their temperatures. The design is cheap and efficient to print 3d scaffolds. Our Bio-Printer is also aided with a robotic arm to induce any bio-active ingredient in the 3d structures once it is printed without deforming or altering the structure of the scaffold. The main printer can be paused to allow the robotic arm to continue embedding and make repairs to the scaffold from any angle

Effect of welding energy on microstructure and strength of ultrasonic spot welded dissimilar joints of aluminum to steel sheets

Two dissimilar ultrasonic spot welded joints of aluminum to commercial steel sheets at different levels of welding energy were investigated. The tensile lap shear tests were conducted to evaluate the failure strength in relation to microstructural changes. The main intermetallics at the weld interface in both joints was θ (FeAl3), along with ɳ (Fe2Al5) phase in Al-to-AISI 304 stainless steel joint and Fe3Al phase in Al-to-ASTM A36 steel joint, respectively. The welding strength of Al-to-AISI 304 stainless steel weld samples was slightly higher than Al-to-ASTM A36 steel weld samples, whereas the fracture energies of Al-to-AISI 304 stainless steel weld samples were significantly higher as compared with Al-to-ASTM A36 steel weld samples. The welding strength of both Al-to-Steel welds were higher than other reported dissimilar USW joints in literature. The fracture surfaces of both weld joints exhibits the growth of IMC layer with increasing welding energy or time, whose inherent brittleness compromises the integrity of joints. In both cases, the lap shear tensile fracture occurred from the Al/Fe interface at lower energy inputs and the failure mode at higher welding energy inputs became the “transverse through-thickness crack growth” at the edge of the nugget zone on the softer Al side

Microstructure, tensile and fatigue properties of ultrasonic spot welded aluminum to galvanized high-strength-low-alloy and low-carbon steel sheets

The microstructure evolution, tensile lap shear strength and fatigue properties of dissimilar ultrasonic spot welded (USWed) joints of aluminum to two commercial steel sheets at different welding energies were investigated. The main intermetallics at the weld interface were θ (FeAl3) in both joints along with eutectic Al-Zn in Al-to-galvanized high-strength-low-alloy (HSLA) steel joints and Fe3Al in Al-to-ASTM A36 steel joints. The welding strengths of both joints were higher than those of other dissimilar joints reported in the literature. With increasing welding energy, the maximum tensile lap shear strength increased in the Al-to-galvanized HSLA steel joints, while the lap shear strength increased up to a peak value and then decreased in the Al-to-ASTM A36 steel joints. Both the average peak welding strength and fracture energy of the Al-to-galvanized HSLA steel joints were higher than those of the Al-to-ASTM A36 steel joints. The fatigue lives of both welded joints were in agreement with or somewhat longer than other Al-to-steel USWed joints in the literature. The fatigue fracture mode changed with increasing cyclic loads in both welded joints. Fatigue crack growth was mainly characterized by the formation of fatigue striations perpendicular to the fatigue crack propagation direction

Sex determination in ratite and non ratite birds by molecular method

In spite of number of methods for sex determination in birds, it is very difficult to distinguish sex especially in ratite birds due to lack of sexual dimorphism. Chromodomain helicase DNA binding 1 gene (CHD 1) is the choice of gene for gender differentiation using PCR based molecular method. In present study, non ratite CHD gene specific primers viz. 1237L/1272H, 2550F/2718R, P2/P8, P2/P3 and ratite bird specific primers viz.W5/ W7 and W1/ K7 were used for gender differentiation in ratite birds. The ratite bird specific primer W5/W7 was the only primer, which determined the sex in emu as well as ostrich successfully, while 1237L/1272H, 2550F/2718R, P2/ P8, P2/P3 primers were unable to discriminate sex in emu and ostrich but ratite and non ratite primers can be used to discriminate the sex in non-ratite bird, primarily in chicken. In an alternative approach of PCR-RFLP, the high resolution melting curve (HRM) analysis showed conflicting pattern in both sexes of ratite birds but in chicken HRM analysis showed clear cut differential melting temperature in both sexes, hence HRM can be used for gender differentiation successfully

Cellular Automata Applications in Shortest Path Problem

Cellular Automata (CAs) are computational models that can capture the essential features of systems in which global behavior emerges from the collective effect of simple components, which interact locally. During the last decades, CAs have been extensively used for mimicking several natural processes and systems to find fine solutions in many complex hard to solve computer science and engineering problems. Among them, the shortest path problem is one of the most pronounced and highly studied problems that scientists have been trying to tackle by using a plethora of methodologies and even unconventional approaches. The proposed solutions are mainly justified by their ability to provide a correct solution in a better time complexity than the renowned Dijkstra's algorithm. Although there is a wide variety regarding the algorithmic complexity of the algorithms suggested, spanning from simplistic graph traversal algorithms to complex nature inspired and bio-mimicking algorithms, in this chapter we focus on the successful application of CAs to shortest path problem as found in various diverse disciplines like computer science, swarm robotics, computer networks, decision science and biomimicking of biological organisms' behaviour. In particular, an introduction on the first CA-based algorithm tackling the shortest path problem is provided in detail. After the short presentation of shortest path algorithms arriving from the relaxization of the CAs principles, the application of the CA-based shortest path definition on the coordinated motion of swarm robotics is also introduced. Moreover, the CA based application of shortest path finding in computer networks is presented in brief. Finally, a CA that models exactly the behavior of a biological organism, namely the Physarum's behavior, finding the minimum-length path between two points in a labyrinth is given.Comment: To appear in the book: Adamatzky, A (Ed.) Shortest path solvers. From software to wetware. Springer, 201

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

A simple assay for the simultaneous determination of rosuvastatin acid, rosuvastatin-5S-lactone, and N-desmethyl rosuvastatin in human plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS)

A simple and sensitive assay was developed and validated for the simultaneous quantification of rosuvastatin acid (RST), rosuvastatin-5S-lactone (RST-LAC), and N-desmethyl rosuvastatin (DM-RST), in buffered human plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS). All the three analytes and the corresponding deuterium-labeled (d6) internal standards were extracted from 50 μL of buffered human plasma by protein precipitation. The analytes were chromatographically separated using a Zorbax-SB Phenyl column (2.1 mm∈×∈100 mm, 3.5 μm). The mobile phase comprised of a gradient mixture of 0.1% v/v glacial acetic acid in 10% v/v methanol in water (solvent A) and 40% v/v methanol in acetonitrile (solvent B). The analytes were separated at baseline within 6.0 min using a flow rate of 0.35 mL/min. Mass spectrometry detection was carried out in positive electrospray ionization mode. The calibration curves for all three analytes were linear (R ≥ 0.9964, n=3) over the concentration range of 0.1-100 ng/mL for RST and RST-LAC, and 0.5-100 ng/mL for DM-RST. Mean extraction recoveries ranged within 88.0-106%. Intra- and inter-run mean percent accuracy were within 91.8-111% and percent imprecision was ≤15%. Stability studies revealed that all the analytes were stable in matrix during bench-top (6 h on ice-water slurry), at the end of three successive freeze and thaw cycles and at -80°C for 1 month. The method was successfully applied in a clinical study to determine the concentrations of RST and the lactone metabolite over 12-h post-dose in patients who received a single dose of rosuvastatin. [Figure not available: see fulltext.] © 2011 Springer-Verlag