The Effects of Surface Curvature on Cartilage Behaviour in Indentation Test: A Finite Element Study

Computational modelling of the behaviour of articular cartilage is important in order to improve the understanding of disease processes such as arthritis, and the suitability of biomaterials in surgical treatment. In previous computational studies, the cartilage surface of axisymmetric models was assumed to be flat in order to evaluate the cartilage behaviour. This assumption was inappropriate since the synovial joint possessed curvature geometrical shape and may contribute to inaccurate results. Therefore, this study aims to examine the effects of the cartilage surface curvature to the cartilage behavior in indentation test using finite element analysis. Axisymmetric biphasic poroelastic finite element models of flat and various cartilage surface radii, including both concave and convex shapes of the curve, were generated to simulate creep indentation test in order to investigate possible effect to the contact stress and pore pressure of the cartilage. Based on the results, the smaller cartilage surface of 10 mm radius produced higher difference of the cartilage behaviour where it generated 39% difference in pore pressure and 6% difference in contact stress, compared to the flat cartilage. This could indicate that the cartilage curvature does affect the cartilage behavior in indentation test particularly the pore pressure of cartilage

Long - term conservation agriculture increases nitrogen use efficiency by crops, land equivalent ratio and soil carbon stock in a subtropical rice - based cropping system

Conservation Agriculture (CA) is still a relatively new approach for intensively cultivated (3 crops yr-1) rice-based cropping systems that produce high crop yield and amounts of residues annually. With the recent development of transplanting of rice into tilled strips on non-puddled soil, CA could become feasible for rice-based cropping patterns. However, the effect of increased retention of crop residues on crop response to nitrogen (N) fertilization rate in strip tilled systems with the transplanted rice and other crops grown in the annual rotation is yet to be determined. For nine years, we have examined the effects of soil disturbance levels - strip tillage (ST) and conventional tillage (CT), two residue retention levels –15% residue by height (low residue, LR) and 30% residue (high residue, HR) and five N rates (60%, 80%, 100%, 120%, and 140% of the recommended N fertilizer doses (RFD)) for a rice-wheat-mungbean cropping sequence. The 100% RFD was 75, 100 and 20 kg N ha-1for rice, wheat, and mungbean, respectively. Rice yields were comparable between the two tillage systems for up to year-6, wheat for up to year-3 but mungbean yield markedly increased in ST from year-1; however, the land equivalent ratio increased from year-1, principally because of higher mungbean yield. Introduction of ST increased land equivalent ratio by 26% relative to CT, N use efficiency and partial factor productivity. Nitrogen fertilizer demand for maximum yield in ST was increased by about 10% for rice and 5% for mungbean but decreased by 5% for wheat. Although fertilizer N demand had increased in ST system due to higher yield than CT, the N requirement declined by50–90% when the same yield goal is considered for ST as for CT. The soil organic carbon stock (0–15 cm) after 8 years increased from 21.5 to 30.5 t ha-1 due to the effect of ST plus high crop residue retention. Annual gross margin increased by 57% in ST over CT practice and 26% in HR over LR retention. In conclusion, after 9 years practicing CA with increased residue retention under strip tillage, the crops had higher N use efficiency, grain yield, land equivalent ratio and annual gross margin in the rice-wheat-mungbean cropping system while the N fertilizer requirement increased minimally

Sugar Palm (Arenga Pinnata (Wurmb.) Merr) Cellulosic Fibre Hierarchy: A Comprehensive Approach From Macro To Nano Scale

Sugar palm (Arenga pinnata) fibre is considered as a waste product of the agricultural industry. This paper is investigating the isolation of nanofibrillated cellulose from sugar palm fibres produced by a chemo-mechanical approach, thus opening a new way to utilize waste products more efficiently. Chemical pre-treatments, namely delignification and mercerization processes, were initially involved to extract the sugar palm cellulose. Then, mechanical pre-treatment was performed by passing the sugar palm cellulose through a refiner to avoid clogging in the subsequent process of high pressurized homogenization. Nanofibrillated cellulose was then characterized by its chemical properties (Fourier transform infrared spectroscopy), physical morphological properties (i.e. scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis), and thermogravimetric analysis.The nanofibres were attained at 500 bar for 15 cycles with 92% yield. The results showed that the average diameter and length of the nanofibrillated cellulose were found to be 5.5 ± 1.0nm and several micrometres, respectively. They also displayed higher crystallinity (81.2%) and thermal stability compared to raw fibres, which served its purpose as an effective reinforcing material for use as bio-nanocomposites. The nanocellulose developed promises to be a very versatile material by having a huge potential in many applications, encompassing bio-packaging to scaffolds for tissue regeneratio

Bose-Einstein condensates in a one-dimensional double square well: Analytical solutions of the Nonlinear Schr\"odinger equation and tunneling splittings

We present a representative set of analytic stationary state solutions of the Nonlinear Schr\"odinger equation for a symmetric double square well potential for both attractive and repulsive nonlinearity. In addition to the usual symmetry preserving even and odd states, nonlinearity introduces quite exotic symmetry breaking solutions - among them are trains of solitons with different number and sizes of density lumps in the two wells. We use the symmetry breaking localized solutions to form macroscopic quantum superpositions states and explore a simple model for the exponentially small tunneling splitting.Comment: 11 pages, 11 figures, revised version, typos and references correcte

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Comparative study between flat and uniform bottom assumptions for snippet imageries in hydrographic applications

The length of each snippet data varies with the ensonified area of the beam foot print, which is a function of incidence angle and water depth. Generally, the seabed topology is undulated and it is challenging to determine the exact angle of incident. Therefore the snippet is divided into two operational modes; uniform and flat bottom in order to cope with the complexity of the seabed. However, these assumptions are invalid in real situations most of the time. This study focuses on comparing these two bottom assumption techniques in bottom classification and coverage accuracy using the RESON Seabat 8124 multibeam system at Johor Bahru, Malaysia. Comparative analysis were carried out using hit counts and data gaps interpretation for geometric distortions, intensity profiles and volume comparisons for radiometric distortions in the classified mosaic seabed imagery. Both modes gave a mean difference of 0.54 intensity units on flat seabed areas and 5.97 units on the slope. The data density of the uniform mode is also high. This concludes that one may use either technique for flat areas. But for undulated areas, one has to be careful in selecting the snippet modes, as the real seabed is not completely flat or uniformly sloped

Neurosurgical infections

The central nervous system is a very delicate and vulnerable organ which enjoys protection by layers of coverings. It is described as an immunological vacuum, and when afflicted by infections the outcome is most often devastating. Factors leading to compromise of the host defense play a major role in establishing neurosurgical infections. A number of such factors can either be avoided or minimized. Over the past decades, these infections have been fatal. However, more recently, the advent of newer more effective antibiotics, improved bacteriological studies, advanced imaging facilities, and meticulous surgical techniques have turned around the outcomes. This article will review infections of the central nervous system of neurosurgical significance

General and advanced diagnostic tools to detect Mycobacterium tuberculosis and their drug susceptibility: a review

Contains fulltext : 155340.pdf (publisher's version ) (Closed access)The global control of tuberculosis remains a great challenge from the standpoint of diagnosis, detection of drug resistance, and treatment, because treatment can only be initiated when infection is detected, and is guided by the results of antimicrobial susceptibility testing. To a large extent, non-molecular, immunological, and other biochemical methods are refinements or modifications of conventional methods, with the primary goal of providing more rapid test results. In contrast, molecular methods use novel technologies to detect the presence of Mycobacterium tuberculosis complex and genes conferring drug resistance. As a group, molecular technologies offer the greatest potential for laboratories in resource-rich countries because they have the highest sensitivity and specificity. In resource-poor settings, continued development of affordable, sensitive, and specific diagnostic tools will be required, where the incidence of disease is highest

WATER COLUMN FEATURES AND SEAFLOOR CHARACTERISTICS USING SIMULTANEOUS MULTIBEAM WATER COLUMN DETECTION

Simultaneous mid-water and seafloor classification enables the study of the relationship between seafloor characteristics and water column features known as habitat interactions. Normally, the focus of these data is only on one part of either the water column or the seafloor. This water column data is usually filtered out to form an accurate bathymetric surface. Otherwise, this will cause data duplication or loss and degrade the accuracy of the data. This study aimed to produce a comprehensive map using a Multibeam Echosounder System (MBES). The data acquisition was carried out using WASSP WMB-160f MBES and a camera recorder was used for verification. Data comparison was carried out through bathymetric and backscatter analysis and filtered at the minimum threshold.  The result showed that both data were able to be detected simultaneously at a comparable and effective result without neglecting any details behind. The water column data was at good resolution for detection below the 300 kHz, although the data obtained from this study did not show the real shape and size of the detected object. In addition, the seafloor could also be well detected and properly classified according to survey requirements