Bachia heteropa

Number of Pages: 10Integrative BiologyGeological Science

Design and fabrication of 3D-printed anatomically shaped lumbar cage for intervertebra disc (IVD) degeneration treatment

Spinal fusion is the gold standard surgical procedure for degenerative spinal conditions when conservative therapies have been unsuccessful in rehabilitation of patients. Novel strategies are required to improve biocompatibility and osseointegration of traditionally used materials for lumbar cages. Furthermore, new design and technologies are needed to bridge the gap due to the shortage of optimal implant sizes to fill the intervertebral disc defect. Within this context, additive manufacturing technology presents an excellent opportunity to fabricate ergonomic shape medical implants. The goal of this study is to design and manufacture a 3D-printed lumbar cage for lumbar interbody fusion. Optimisations of the proposed implant design and its printing parameters were achieved via in silico analysis. The final construct was characterised via scanning electron microscopy, contact angle, x-ray micro computed tomography (μCT), atomic force microscopy, and compressive test. Preliminary in vitro cell culture tests such as morphological assessment and metabolic activities were performed to access biocompatibility of 3D-printed constructs. Results of in silico analysis provided a useful platform to test preliminary cage design and to find an optimal value of filling density for 3D printing process. Surface characterisation confirmed a uniform coating of nHAp with nanoscale topography. Mechanical evaluation showed mechanical properties of final cage design similar to that of trabecular bone. Preliminary cell culture results showed promising results in terms of cell growth and activity confirming biocompatibility of constructs. Thus for the first time, design optimisation based on computational and experimental analysis combined with the 3D-printing technique for intervertebral fusion cage has been reported in a single study. 3D-printing is a promising technique for medical applications and this study paves the way for future development of customised implants in spinal surgical applications

Neuroendocrine and neurotrophic signaling in Huntington\u27s disease: Implications for pathogenic mechanisms and treatment strategies

Huntington\u27s disease (HD) is a fatal neurodegenerative disease caused by an extended polyglutamine tract in the huntingtin protein. Circadian, sleep and hypothalamic-pituitary-adrenal (HPA) axis disturbances are observed in HD as early as 15 years before clinical disease onset. Disturbances in these key processes result in increased cortisol and altered melatonin release which may negatively impact on brain-derived neurotrophic factor (BDNF) expression and contribute to documented neuropathological and clinical disease features. This review describes the normal interactions between neurotrophic factors, the HPA-axis and circadian rhythm, as indicated by levels of BDNF, cortisol and melatonin, and the alterations in these intricately balanced networks in HD. We also discuss the implications of these alterations on the neurobiology of HD and the potential to result in hypothalamic, circadian, and sleep pathologies. Measurable alterations in these pathways provide targets that, if treated early, may reduce degeneration of brain structures. We therefore focus here on the means by which multidisciplinary therapy could be utilised as a non-pharmaceutical approach to restore the balance of these pathways

What difference does it make? Findings of an impact study of service user and carer involvement on social work students’ subsequent practice

This paper reports on a study which followed up a group of social work students to explore whether service user involvement in their education made any difference to their practice and whether there were different models or types of involvement which had a more significant impact than others. The findings showed that the impact was individual to each student. It was often specific encounters or ‘light bulb moments’ which led to increased awareness or insight into their own practice particularly when encountering similar situations or when pressures of practice led to them losing sight of service user perspectives. The paper shares these findings and considers the learning for educators in developing models of involvement which enhance impact on subsequent practice

A Revolutionary Lunar Space Transportation System Architecture Using Extraterrestrial Lox-augmented NTR Propulsion

The concept of a liquid oxygen (LOX)-augmented nuclear thermal rocket (NTR) engine is introduced, and its potential for revolutionizing lunar space transportation system (LTS) performance using extraterrestrial 'lunar-derived' liquid oxygen (LUNOX) is outlined. The LOX-augmented NTR (LANTR) represents the marriage of conventional liquid hydrogen (LH2)-cooled NTR and airbreathing engine technologies. The large divergent section of the NTR nozzle functions as an 'afterburner' into which oxygen is injected and supersonically combusted with nuclear preheated hydrogen emerging from the NTR's choked sonic throat: 'scramjet propulsion in reverse.' By varying the oxygen-to-fuel mixture ratio (MR), the LANTR concept can provide variable thrust and specific impulse (Isp) capability with a LH2-cooled NTR operating at relatively constant power output. For example, at a MR = 3, the thrust per engine can be increased by a factor of 2.75 while the Isp decreases by only 30 percent. With this thrust augmentation option, smaller, 'easier to develop' NTR's become more acceptable from a mission performance standpoint (e.g., earth escape gravity losses are reduced and perigee propulsion requirements are eliminated). Hydrogen mass and volume is also reduced resulting in smaller space vehicles. An evolutionary NTR-based lunar architecture requiring only Shuttle C and/or 'in-line' shuttle-derived launch vehicles (SDV's) would operate initially in an 'expandable mode' with NTR lunar transfer vehicles (LTV's) delivering 80 percent more payload on piloted missions than their LOX/LH2 chemical propulsion counterparts. With the establishment of LUNOX production facilities on the lunar surface and 'fuel/oxidizer' depot in low lunar orbit (LLO), monopropellant NTR's would be outfitted with an oxygen propellant module, feed system, and afterburner nozzle for 'bipropellant' operation. The LANTR cislunar LTV now transitions to a reusable mode with smaller vehicle and payload doubling benefits on each piloted round trip mission. As the initial lunar outposts grow to centralized bases and settlements with a substantial permanent human presence, a LANTR-powered shuttle capable of 36 to 24 hour 'one-way' trip times to the moon and back becomes possible with initial mass in low earth orbit (IMLEO) requirements of approximately 160 to 240 metric tons, respectively

Comparative Investigation of Foot Blood Flow Dynamics: A Study of the Anterior and Posterior Tibial Arteries in the Sitting vs. Standing Positions

Optimal blood circulation is crucial to perform activities of daily living and for living a healthy life. For example, insufficient blood flow to the foot contributes to the development of foot pathology such as plantar fasciopathy. An unshod simulation of tight and narrow shoes showed decrease blood flow to the foot. PURPOSE: This study investigated if there was a significant decrease in blood flow to the foot via the anterior and posterior tibial arteries when an unshod person transitions from sitting to standing. METHODS: Nine individuals participated in this pilot study (age=24.7±4.4, weight=72.7kg±8.8, height=1.8m±0.07). For the sitting position, participants sat on a platform while blood flow volume measurements were taken simultaneously of the anterior and posterior tibial arteries using ultrasound pulse wave. For the standing measurements, the participants stood on the platform and the same measurements were taken. A period of three minutes after standing was implemented before standing measurements were taken to ensure that blood flow adjusted to the new position. A paired t-test was used to compare sitting to standing differences within the participants. RESULTS: In the anterior tibial artery, average volume flow changed from 4.88 ml/min (sitting) to 2.76 ml/min (standing), a 43.4% drop in blood flow (p\u3c0.01). In the posterior tibial artery, volume flow decreased from an average of 5.01 ml/min to 3.69 ml/min, a decrease of 26.3% (p\u3c0.05). Total reduced blood flow between the two arteries decreased from 9.89 ml/min to 4.88 ml/min, a 50.6% drop (p\u3c0.01). CONCLUSION: This study demonstrates a simple change in position significantly impacts blood flow to the foot. This suggests further research is needed to determine if there is an additive effect of footwear on this observed decrease in blood flow that may contribute to an increase incidence rate of plantar fasciopathy. This finding additionally provides rationale to investigate what mechanism the body uses to overcome positional-related decreases in blood flow