Improvement of mechanical performance on zirconium dioxide nanoparticle synthesized magnesium alloy nano composite

With excellent mechanical properties and distinct solidification, the AZ31B series magnesium alloy has great potential for targeting engineering applications and synthesized via die casting process found a drawback on oxidation results porosity and reduced mechanical properties. Here, the magnesium alloy AZ31B series nanocomposite was synthesized with varied weight percentages of zirconium dioxide nanoparticles through a liquid metallurgy route with an applied stir speed of 200 rpm under an argon nature. With the help of a scanning electron microscope, the distribution of particles in the composite surface was found to be homogenous and void-free surface, which output results in less percentage of porosity (<1 %), and the composite contained 6 wt% ZrO2 offers superior yield strength (212 ± 3 MPa), tensile strength (278 ± 2 MPa), and impact strength of 16.4 ± 0.4 J/mm2. In addition, 8 wt% ZrO2 blended composite showed the maximum microhardness value (78.3 ± 1 HV). The best-enhanced result of NC3 (AZ31B/6 wt% ZrO2) is suggested for lightweight to high-strength structural applications.

Performance evaluation and chemical oxygen demand removal of tannery wastewater through the aerobic-anaerobic route

With characterized for complex and maximum substance (suspended solids, broke up oil, a mixture of inorganic and chromium sulfides), tannery wastewater was subjected to a treatment process on removal of chemical oxygen demand (COD) via upstream anaerobic sludge blanket reactor where we found reduced departure efficiencies and that process limits were affected by the assortments in regular stacking rates, closeness of chromium, and sulfides. Hence, a combination of the aerobic-anaerobic hybrid reactor was set up for sequential treatment to determine possible COD reduction. This study investigated the biological degradation of tannery wastewater in a laboratory-scale sequential up-flow aerobic-anaerobic reactor. The aerobic zone at the top was packed with spherical ball-shaped polyhedral polypropylene, and the anaerobic zone at the bottom was packed medium with granular media. The aeration flow rate varied by 2 L/min, 4 L/min, and 6 L/min in the aerobic zone, and the reactor maintained an organic loading rate (OLR) of 5 kg COD/m3/d. Parameters like COD and gas yield assess the performance of the reactor. The maximum COD of 86% is removed in the anaerobic zone with an aeration rate of 6 L/min, and the 1800-mL methane gas yield is measured by the 29th day.

Charge Puddles Driven Complex Crossover of Magnetoresistance in Non-Topological Sulfur Doped Antimony Selenide Nanowires

A race to achieve a crossover from positive to negative magnetoresistance is intense in the field of nanostructured materials to reduce the size of memory devices. Here, the unusual complex magnetoresistance in nonmagnetic sulfur-doped Sb2 Se3  nanowires is demonstrated. Intentionally, sulfur is doped in such a way to nearly achieve the charge neutrality point that is evident from switching of carrier type from p-type to n-type at 13 K as inferred from the low-temperature thermoelectric power measurements. A change from 3D variable range hopping (VRH) to power law transport with α = 0.18  in resistivity measurement signifies a Luttinger liquid transport with weak links through the nanowires. Interestingly, high magnetic field induced negative magnetoresistance (NMR) occurring in hole dominated temperature regimes can only be explained by invoking the concept of charge puddles. Spot energy dispersive spectroscopy (EDS), magnetic force microscopy (MFM) measurements, Tmott  and Regel plot indicate an enhanced disorder in these sulfurized nanowires that are found to be the precursor for the formation of these charge puddles. Tunability of conducting states in these nanowires is investigated in the light of interplay of carrier type, magnetic field, temperature, and intricate intra-inter wire transport that makes this nanowires potential for large scale spintronic devices.

Influence of heat input on the mechanical characteristics, corrosion and microstructure of ASTM A36 steel welded by GTAW technique

The Gas Tungsten Arc Welding process weld for the 4 mm thickness of the ASTM A36 steel plate with varied heat input parameters of 0.608 kJ/mm, 0.900 kJ/mm and 1.466 kJ/mm, respectively. The effect of different heat inputs on microstructure, corrosion, and mechanical characteristics of developed weld joints are examined by three zones: heat-affected zone, welded zone, and base metal zone. The optical microscopic results of weld joints illustrate that fine grain structure leads to enhance welding strength. It is revealed that the increased heat input parameter on the weld joint shows a decreased tensile strength and hardness of the weld joint. The corrosion resistance of the weld joint is evaluated by Potentio-dynamic polarization. It facilitates that the corrosion rate of the weld joint is decreased with increasing heat input, which results indicate the best and worst corrosion micrograph of the polygonal ferrite and ferrite plus polygonal ferrite. However, the weld joint prepared with 0.900 kJ/mm heat input found maximum corrosion resistance.

Optimization and prediction of CBN tool life sustainability during AA1100 CNC turning by response surface methodology

The aluminium alloy (AA1100) was familiar with automotive flexible shaft coupling applications due to its high strength, good machinability, and superior thermal and resistance to corrosion characteristics. Machining tool life drives the prominent role for deciding the product quality (machining) act aims to productivity target with zero interruptions. The novelty of this present investigation is the focus on increasing tool life during the complexity of CNC turning operation for AA1100 alloy by using CBN coated insert tool with varied input parameters of spindle speed (SS), feed rate (f), and depth of cut (DOC). Design of experiment (L16), analysis of variance (ANOVA) statistical system adopted with response surface methodology (RSM) is implemented for experimental analysis. The turning input parameters of SS, f and DOC are considered as factors and its SS (900, 1100, 1300, and 1500 rpm), f (0.1, 0.15, 0.2, and 0.25), and DOC (0.1, 0.2, 0.3, and 0.4 mm) values are treated as levels. The investigational analysis was made with the ANOVA technique and the desirability of high tool life with input turning parameters was optimized by RSM, and sample no 11/16 was predicted as high tool life and performed with extended working hours compared to other samples. The RSM optimized best turning parameter combinations are 0.1 mm DOC, 0.2mm/rev to 0.25mm/rev f, and 1300 rpm-1500 rpm SS, facilitating a higher tool life of more than 20min.

Incremental innovations in operation theaters

Background

The field of ophthalmology has been built upon continuous innovations. COVID-19 pandemic has been an important driving force behind many innovations in ophthalmology and other branches of medicine. Innovations in ophthalmology has been a key to surgical progress. The process of promoting innovation in surgery is imperative in the evolving practice of ophthalmology.

Purpose

In this video we demonstrate some incremental innovations in operation theaters which help in increasing the efficiency and improving the performance of a surgeon. These innovations also provide a more comfortable environment for the patient undergoing the surgery.

Synopsis

A few incremental innovations that are described in our video also help in preventing the spread of COVID infection during surgery. This video also showcases a few wet lab innovations that help train residents in their surgical skills.

Highlights

Use and reuse of simple materials make it cost effective and ecofriendly. These incremental innovations help in the smooth running of operation theaters. Thus, they are small improvements in the existing setup and help in creating a smooth and error free OT flow.

Video Link

https://youtu.be/thFLvC-XykE.

Effect of fiber layer formation on mechanical and wear properties of natural fiber filled epoxy hybrid composites

Natural fiber-reinforced polymer matrix composites are gathering significance in future trend applications such as automotive, aerospace, sport, and other engineering applications due to their superior enhanced mechanical, wear, and thermal properties. Compared to synthetic fiber, natural fiber is low adhesive and flexural strength properties. The research aims to synthesize the epoxy hybrid composites by utilizing the silane (pH = 4) treated Kenaf (KF) and sisal fiber (SF) as layering by uni, bi, and multi-unidirectional via hand layup techniques. Thirteen composite samples have been prepared by three-layer formation adopted with different weight ratios of E/KF/SF such as 100E/0KF/0SF, 70E/30KF/0SF, 70E/0KF/30SF, 70E/20KF/10SF, and 70E/10KF/20SF respectively. The effect of layer formation on the tensile, flexural, and impact strength of composites is studied by ASTM D638, D790, and D256 standards. The unidirectional fiber layer formed (sample 5) 70E/10KF/20SF composite is found maximum tensile and flexural strength of 57.9 ± 1.2 MPa and 78.65 ± 1.8 MPa. This composite is subjected to wear studies by pin-on-disc wear apparatus configured with a hardened grey cast-iron plate under an applied load of 10, 20, 30, and 40 N at different sliding velocities of 0.1, 0.3, 0.5, and 0.7 m/s. The wear rate of the sample progressively increases with increasing load and sliding speed of the composite. The minimum wear rate of 0.012 mg/min (sample 4) is found on 7.6 N frictional force at 0.1 m/s sliding speed. Moreover, sample 4 at a high velocity of 0.7 m/s with a low load (10 N) shows a wear rate of 0.034 mg/min. The wear-worn surface is examined and found adhesive and abrasive wear on a high frictional force of 18.54 N at 0.7 m/s. The enhanced mechanical and wear behavior of sample 5 is recommended for automotive seat frame applications.

Mechanical alloying of Mg0.8-XTi0.2 and study the effect of adding (x = 0.2 wt%) transition metal like Sc, Zr, or Nb on their phase transitions, activation energy, and hydrogen storage properties

Till now Mg-based alloys have attracted much attention due to the high storage capacity of hydrogen. An effort was made to evaluate the apparent activation energy and electrochemical behavior of transition metals such as scandium (Sc), zirconium (Zr), and niobium (Nb) alloyed with Mg-Ti. Mg_0.8Ti_0.2, Mg_0.6Ti_0.2Sc_0.2, Mg_0.6Ti_0.2Zr_0.2, and Mg_0.6Ti_0.2Nb_0.2 alloy powders were synthesized using high-energy ball milling. Ballmilled powders were subjected to structural and morphological characterization using X-ray diffraction and scanning electron microscopy respectively. A strong shift in the inter-planar spacing value of milled powders confirmed supersaturated solid solution of Ti and transition metals in Mg. The inter-planar spacing values before and after milling are found to be 0.24 and 0.21 nm, respectively. Mg_0.8Ti_0.2, Mg_0.6Ti_0.2Sc_0.2, and Mg_0.6Ti_0.2Zr_0.2 alloy powders result in the FCC phase while Mg_0.6Ti_0.2Nb_0.2 powders result in BCC phase, however, the entire powders have an amorphous background. SEM-EDS analysis of the milled powders confirmed the presence of Mg, Ti, Sc, Zr, and Nb elements with a small amount of oxygen. Selected area electron diffraction (SAED) pattern of Mg_0.8Ti_0.2 alloy powders exhibits a nanocrystalline nature owing to their polycrystalline ring pattern. Exothermic peak broadening increases after the substitution of Nb and Zr in Mg_0.8Ti_0.2 alloy powder, which exhibits a lower activation energy (188 kJ mol^-1) than others. In cyclic voltammetry, a drenched cathodic peak is observed for Mg_0.8Ti_0.2 at a potential around -0.83 V. In electrochemical impedance spectroscopy, the charge transfer resistance of Mg_0.6Ti_0.2Sc_0.2 is lower than that of Mg_0.6Ti_0.2Zr_0.2 and Mg_0.6Ti_0.2Nb_0.2 alloy but higher than Mg_0.8Ti_0.2 electrode materials, and charge-discharge studies were done on the developed electrode materials. It shows that Mg_0.8Ti_0.2 electrode material delivers a maximum discharge capacity of 535 mA h g^-1.

Optimization of NaCl based spray corrosion test process parameters of heat treated hybrid metal matrix composites

ABSTRACT. Aluminium hybrid metal matrix composites (AHMMCs) have widely employed in aerospace, transportation, and automotive applications since for their excellent mechanical qualities and high corrosion resistance. In this research, Al8079 is selected as a matrix material. The titanium diboride (TiB2) is selected as hard reinforcement and molybdenum disulfide (MoS2) is used as soft reinforcement. The Al8079/15 wt.% TiB2/x wt.% MoS2 (x = 0, 2.5, 5 and 7.5) HMMCs are fabricated by using stir casting. The composites are heat treated under T6 condition. The density and micro hardness tests are conducted. The optimization on NaCl based spray corrosion test process parameters is done using grey relational analysis (GRA). The selected input process parameters are Al8079/15 wt.% TiB2/wt.% MoS2 (x = 0, 2.5 and 5), pH value of NaCl solution (x = 6, 9 and 12), hang time (x = 24, 48, and 72 h) and pressure (x = 0.7, 0.9 and 1.1 kg/cm2). The selected response parameters are micro hardness, mass loss and wear loss. The L9 Taguchi design is used for optimization. The wear test is conducted at the constant speed of 0.5 m/s, loading rate of 20 N and the sliding distance of 1000 m. The percentage of improvement of GRG from initial setting to experimental is 10.4%.   KEY WORDS: Reinforcement, Stir casting, Optimization, GRA, NaCl Bull. Chem. Soc. Ethiop. 2022, 36(4), 903-914.                                                         DOI: https://dx.doi.org/10.4314/bcse.v36i4.15

Two-Dimensional Weak Antilocalization Signatures Due to Quantum Coherent Transport in Nanocrystalline SnTe

Nanostructured topological crystalline insulators (TCIs) in the presence of exotic surface states with spin momentum locking reported in individual nanostructures are predicted to hold a great promise for spintronics and quantum computing applications. However, practical application demands a strategy with large-scale production and integration for device applications. In this work, we demonstrate through prominent signatures of weak antilocalization (WAL), arising predominantly from destructive quantum interference on robust surface states, that a correlated TCI phase is possible in the nanobulk assembly of carefully nanostructured quasi-two-dimensional SnTe (edge-to-edge length ∼ 382 nm) synthesized by a simple, rapid, and scalable microwave-assisted solvothermal method. Hikami-Larkin-Nagaoka analysis (T^-0.71), as well as the temperature dependence of resistivity, illustrates an interplay of both conductions from 2D channels and 3D EEI effects as the precursor for the observed WAL at low temperatures (2-6 K). Interestingly, the enhanced thermoelectric power of the sample of ∼45 μV/K, with a p-type carrier concentration of ∼10¹⁸/cm³ at 300 K, makes this SnTe nanocrystalline assembly more attractive as a multifunctional material for large-scale technological applications.

Heart disease diagnosis using optimized features of hybridized ALCSOGA algorithm and LSTM classifier

Cardiac disease is the predominant cause of global death mainly due to its hidden symptoms and late diagnosis. Hence, early detection is important to improve quality of life. Though traditional researches attempted to predict heart disease, most of them lacked with respect to accuracy. To solve this, the present study proposes a hybridized Ant Lion Crow Search Optimization Genetic Algorithm (ALCSOGA) to perform effective feature selection. This hybrid optimization encompasses Ant Lion, Crow Search and Genetic Algorithm. Ant lion algorithm determines the elite position. While, the Crow Search Algorithm utilizes the phenomenon of position and memory of each crow for evaluating the objective function. Both these algorithms are fed into Genetic Algorithm to improve the performance of feature selection process. Then, Stochastic Learning rate optimized Long Short Term Memory (LSTM) is proposed to classify the extracted optimized features. Finally, comparative analysis is performed in terms of accuracy, recall, F1-score, and precision. Moreover, statistical analysis is performed with respect to Sum of Squares (SS), degree of freedom (df), F Critical (F crit), F Statistics (F), p, and Mean Square (MS) value. Analytical results revealed the efficiency of proposed system over conventional methods and thereby confirming its efficiency for predicting heart disease.

Deep Learning Model for Epileptic Seizure Prediction

Prediction of occurrence of a seizure would be of greater help to make necessary precaution for taking care of the patient. A Deep learning model, recurrent neural network (RNN), is designed for predicting the upcoming values in the EEG values. A deep data analysis is made to find the parameter that could best differentiate the normal values and seizure values. Next a recurrent neural network model is built for predicting the values earlier. Four different variants of recurrent neural networks are designed in terms of number of time stamps and the number of LSTM layers and the best model is identified. The best identified RNN model is used for predicting the values. The performance of the model is evaluated in terms of explained variance score and R2 score. The model founds to perform well number of elements in the test dataset is minimal and so this model can predict the seizure values only a few seconds earlier.

Service design in the healthcare space with a special focus on non-clinical service departments: A synthesis and future directions

Although there has been a tremendous change in the way diseases are diagnosed and treated, the ways in which health care delivery has been managed has seen very little change.Several academic studies have arisen in the area of service design, but an amalgamation of this research, especially in the area of healthcare services is not available. The aim of this systematic review is to evaluate the published research on service design in healthcare and accordingly identify the gaps and scope of future research. After analyzing the articles and reviewing the Service design in healthcare literature, the following are our main contributions: (i) clarification of the service design concept and the developments that appears in the literature review of service design in the healthcare sector; (ii) classification of the service design tools and techniques that are most commonly used in the healthcare sector; (iii) demonstration of the service design as the preponderant construct that is used as a tool and technique to improve quality and efficiency in the healthcare service.The resultant systematic review reveals a change in the type of research carried out, the service design tools used and a shift towards service design from using the co-design tool to other methods. The paper highlights the gaps in the very limited amount of empirical work in the non-clinical healthcare space and accordingly a model is recommended.

A63 REFINING THE CANADIAN ASSOCIATION OF GASTROENTEROLOGY GUIDELINE ON SCREENING IN PERSONS WITH A FAMILY HISTORY OF NONHEREDITARY COLORECTAL CANCER OR ADENOMA: A MODIFIED DELPHI PROCESS

Background

In 2018, the Canadian Association of Gastroenterology (CAG) published an extensive systematic review and guideline on screening in persons with a family history (FHx) of nonhereditary colorectal cancer (CRC) and adenoma. While CAG’s recommendations were evidence-based, some recommendations lacked precision (e.g. ranges for some start ages & intervals) and screening cessation age was not addressed, leading to implementation challenges for practitioners and CRC screening programs.

Aims

To review and update the evidence since the 2018 guideline and to formulate implementable recommendations in the Ontario context that are aligned with the CAG guideline.

Methods

ColonCancerCheck (Ontario’s organized CRC screening program) conducted a modified version of the literature search used by CAG (Jan 2017 - Sept 2019). A 19-member expert panel with Canadian and international representatives from endoscopy, primary care, epidemiology, organized CRC screening programs, Ontario’s cancer system and the general public refined the recommendations of the CAG guideline for the purposes of implementation in an organized CRC screening program using a modified Delphi process. This iterative process involved a series of webinars and anonymous survey rounds where the panel reviewed evidence materials and provided online feedback to develop, refine & achieve consensus on screening recommendations in persons with a FHx of CRC/adenoma. Consensus was achieved if ≥75% of members agreed or strongly agreed with the statement.

Results

Six new systematic reviews and 2 new guidelines were identified. New evidence included data on the absolute risk (10 year & lifetime risk) of CRC by type of FHx, as well as the performance of fecal immunochemical testing (FIT) and barriers to CRC screening in persons with a FHx of CRC. The expert panel participated in 3 webinars and 4 online surveys to arrive at consensus. Panel recommendations and level of consensus will be reported for the 6 statements (Table).

Conclusions

Building from the CAG guideline, we derived evidence-based and implementable recommendations for screening persons with a FHx of CRC or adenoma.

Funding Agencies

Ontario Health (Cancer Care Ontario)

Screening for vision-threatening diabetic retinopathy in South India: comparing portable non-mydriatic and standard fundus cameras and clinical exam

PurposeTo evaluate the sensitivity and specificity of a portable non-mydriatic fundus camera to diagnose vision-threatening diabetic retinopathy (VTDR).Patients and methodsA prospective, single-site, comparative instrument validation study was undertaken at the Aravind Eye Care System. Overall, 155 subjects with and without diabetes were recruited. Images from 275 eyes were obtained with the (1) non-mydriatic Smartscope, (2) mydriatic Smartscope, and (3) mydriatic table-top camera of the macular, nasal, and superotemporal fields. A retina specialist performed a dilated fundus examination (DFE), (reference standard). Two masked retina specialists graded the images. Sensitivity and specificity to detect VTDR with the undilated Smartscope was calculated compared to DFE.ResultsGraders 1 and 2 had a sensitivity of 93% (95% confidence interval (CI): 87-97%) and 88% (95% CI: 81-93%) and a specificity of 84% (95% CI: 77-89%) and 90% (95% CI: 84-94%), respectively, in diagnosing VTDR with the undilated Smartscope compared to DFE. Compared with the dilated Topcon images, graders 1 and 2 had sensitivity of 88% (95% CI: 81-93%) and 82% (95% CI: 73-88%) and specificity of 99% (95% CI: 96-100%) and 99% (95% CI: 95-100%).ConclusionsRemote graders had high sensitivity and specificity in diagnosing VTDR with undilated Smartscope images, suggesting utility where portability is a necessity.

Spin reorientation and disordered rare earth magnetism in Ho2FeCoO6

We report the experimental observation of spin reorientation in the double perovskite Ho₂FeCoO₆. The magnetic phase transitions in this compound are characterized and studied through magnetization and specific heat, and the magnetic structures are elucidated through neutron powder diffraction. Two magnetic phase transitions are observed in this compound-one at [Formula: see text] K, from paramagnetic to antiferromagnetic, and the other at [Formula: see text] K, from a phase with mixed magnetic structures to a single phase through a spin reorientation process. The magnetic structure in the temperature range 200-45 K is a mixed phase of the irreducible representations [Formula: see text] and [Formula: see text], both of which are antiferromagnetic. The phase with mixed magnetic structures that exists in Ho₂FeCoO₆ gives rise to a large thermal hysteresis in magnetization that extends from 200 K down to the spin reorientation temperature. At T _N2, the magnetic structure transforms to [Formula: see text]. Though long-range magnetic order is established in the transition metal lattice, it is seen that only short-range magnetic order prevails in the Ho³⁺ lattice. Our results should motivate further detailed studies on single crystals in order to explore the spin reorientation process, spin switching and the possibility of anisotropic magnetic interactions giving rise to electric polarization in Ho₂FeCoO₆.

Determination of role of ceruloplasmin in oral potentially malignant disorders and oral malignancy-A cross-sectional study

OBJECTIVES

In the process of carcinogenesis, lipid peroxidation and increased oxidative stress lead to changes in certain antioxidants. This study was aimed to assess and co-relate serum levels of ceruloplasmin in oral premalignancies and oral cancer so as to gauge its possible association with the process of carcinogenesis and to determine its role as tumor marker.

MATERIAL AND METHODS

The study population comprised of 300 participants, equally divided into six study groups, that is, oral submucous fibrosis (OSMF), oral leukoplakia (OL), nicotina stomatitis (NS), oral malignancy (OM), controls (C), and healthy controls (HC); 5 ml of blood was collected from ante cubital vein from each participant. The serum was analyzed for ceruloplasmin levels using ERBA CHEM 5 PLUS semiautomated chemistry analyzer and diagnostic kit by turbidimetric immunoassay.

RESULTS

There were total 242 males and 58 females, who were between 18 and 82 years of age, with a mean of 45.31 ± 13.97 years. The serum ceruloplasmin levels were significantly increased in OM, OSMF, OL, and NS groups as compared to C and HC groups (p < .001). No statistically significant difference was found in intragroup analysis of the disease groups (p > .05).

CONCLUSION

Serum ceruloplasmin can be used as diagnostic marker for oral premalignant and malignant lesions.

Positron emission tomography thyroid incidentaloma: Is it different in Indian subcontinent?

BACKGROUND

Positron emission tomography (PET) forms an integral part in work-up and follow-up of various malignancies. With the increased use of PET in oncology, finding of an incidental focal thyroid uptake (incidentaloma) is not unusual and presents a diagnostic challenge.

AIM

The aim of the following study is to evaluate the frequency and radio-pathologic correlation of focal 18-fluoro deoxyglucose uptake (FDG) on PET within the thyroid from a large series.

MATERIALS AND METHODS

Retrospective review of 37,000 consecutive patients who underwent FDG-PET at tertiary cancer center in India. Radiological, pathological, PET scan and follow-up details were evaluated. Statistical analyzes were carried out using Mann Whitney test and Pearson correlation.

RESULTS

Abnormal thyroid uptake was seen in 78 (0.2%) patients. Nearly 61 (0.16%) scans had focal and 17 (0.04%) had diffuse FDG uptake. A total of 57 patients with focal uptake were available for further evaluation. No further evaluation was done in 24 (42.1%) patients who had advanced index malignancy. Of the remaining 33 patients 26 were benign and seven were a cause for concern (four primary thyroid cancers, one follicular neoplasm with hurthle cell change and two metastatic cancers). There was no significant correlation in Standardized uptake value (SUV) max of benign and malignant lesion (P = 0.5 on Mann Whitney) or size (r = 0.087 Pearson correlation co-efficient P= 0.667).

CONCLUSION

Incidence of PET incidentaloma is low in this large cohort of Indian patients. Nearly 27% of focal incidentaloma were malignant. There was no correlation between the SUVmax, size and malignancy.

Optic nerve head segmentation using fundus images and optical coherence tomography images for glaucoma detection

BACKGROUND

Glaucoma is a common causes of blindness. The associated elevation in intra ocular pressure leads to progressive degeneration of the optic nerve and resultant structural changes with functional failure of the visual field. Since, glaucoma is asymptomatic in the early stages and the associated vision loss is irreparable, its early detection and timely medical treatment is essential to prevent further visual damage.

OBJECTIVE

This paper presents a novel method for glaucoma detection using digital fundus image and optical coherence tomography (OCT) image.

METHOD

The first section focuses on the features such as cup to disc ratio (CDR) and the inferior superior nasal temporal (ISNT) ratio which were obtained from fundus images.The above features were used for classifying the normal and glaucoma condition using back propagation neural network (BPN) and Support Vector Machine (SVM) classifiers. In the second part of the article, features such as CDR and two novel features, cup depth and retinal thickness were obtained from the OCT image. These features were evaluated by the BPN and SVM classifier.

RESULTS AND CONCLUSION

The combined features from fundus and OCT images were analyzed. The system proposed here is able to classify glaucoma automatically. The accuracy of BPN and SVM Classifiers was 90.76% and 96.92% respectively.

Management of neglected sacral fracture with cauda equina syndrome: report of two cases with review of literature

STUDY DESIGN

A retrospective study was performed.

OBJECTIVES

To analyze the outcome of two neglected sacral fractures who presented late to us after 6 weeks of injury with main complaints of incontinence and numbness in sacral region. There are no guidelines for management of complex fractures of sacrum who present late, and available literature is equally perplexing.

METHODS

Patients were evaluated and radiological investigations were done. Anterior-displaced U-shaped fracture was found to be present between S2 and S3 with bony fragments encroaching the canal. Decompression with wide sacral laminectomies was done without any fixation.

RESULTS

Case 1 showed complete recovery of bladder and perineal sensations 6 months post surgery. Second patient (case 2) had partial recovery of bladder control but numbness persisted till last follow-up at 6 months.

CONCLUSION

Neglected fractures of sacrum that present later than 6 weeks post injury with cauda equina syndrome could be given a chance for decompression if imaging shows canal encroachment with bony fragments. Fixation of fracture may not be required in all unstable sacral fractures after 6 weeks.

Directed Assembly of Ultrathin Gold Nanowires over Large Area by Dielectrophoresis

Ultrathin Au nanowires (∼2 nm diameter) are interesting from a fundamental point of view to study structure and electronic transport and also hold promise in the field of nanoelectronics, particularly for sensing applications. Device fabrication by direct growth on various substrates has been useful in demonstrating some of the potential applications. However, the realization of practical devices requires device fabrication strategies that are fast, inexpensive, and efficient. Herein, we demonstrate directed assembly of ultrathin Au nanowires over large areas across electrodes using ac dielectrophoresis with a mechanistic understanding of the process. On the basis of the voltage and frequency, the wires either align in between or across the contact pads. We exploit this assembly to produce an array of contacting wires for statistical estimation of electrical transport with important implications for future nanoelectronic/sensor applications.

Self-cleaning and superhydrophobic CuO coating by jet-nebulizer spray pyrolysis technique

The pocket-sized nebulizer equipped jet-spray coating of a monoclinic CuO crystallite surface showed excellent superhydrophobic self-cleaning properties owing to its compact crystallite texture and high surface roughness.

Syndromes and anomalies associated with cleft

Orofacial clefts are one of the commonest birth defects, and may be associated with other congenital anomalies. The majority of these orofacial clefts are nonsyndromic . A significant percentage of these clefts both syndromic and non-syndromic may have associated anomalies. Apart from reviewing other studies, this article also analyses a study of associated anomalies from a tertiary cleft centre in India.

A novel and non-destructive method to examine meniscus architecture using 9.4 Tesla MRI

OBJECTIVE

To investigate the ability of high-field (9.4 T) magnetic resonance (MR) imaging to delineate porcine knee meniscal tissue structure and meniscal tears.

MATERIALS AND METHODS

Porcine knees were obtained from a local abattoir, and eight medial menisci with no visible defects were dissected. Lesions simulating longitudinal tears were created on two of the menisci. MR images of the menisci were obtained at 9.4 T using a three-dimensional (3D)-FLASH sequence. A detailed 3D internal architecture of the intact and injured menisci was demonstrated on high-resolution MR images.

RESULTS

High-resolution 3D MR imaging allowed visualisation of internal architecture of the meniscus and disruption to the internal structural network in damage models. The architecture of the porcine knee meniscus revealed by the MR scans appeared similar to the structures visualised by histology in previously reported studies.

CONCLUSION

High-field MRI is a non-destructive technique to examine the internal structural components and damage/wear of meniscal tissue. It has tremendous potential in the field of functional cartilage/meniscus biomechanics and biotribology.

Syndromes and anomalies associated with cleft

Orofacial clefts are one of the commonest birth defects, and may be associated with other congenital anomalies. The majority of these orofacial clefts are nonsyndromic. A significant percentage of these clefts both syndromic and non-syndromic may have associated anomalies. Apart from reviewing other studies, this article also analyses a study of associated anomalies from a tertiary cleft centre in India.

Economic cost of cataract surgery procedures in an established eye care centre in Southern India

PURPOSE

To estimate the direct and indirect costs of three cataract surgery procedures: extracapsular cataract extraction with intra-ocular lens implantation (ECCE-IOL), phacoemulsification (PHACO) and manual small incision cataract surgery (MSICS) using economic costing principles in a well-established eye care programme (Aravind Eye Hospital) in Tamil Nadu, South India during 2000-01. Previous literature suggests that PHACO and MSICS have similar effectiveness.

METHODS

The average unit cost for each surgical procedure was calculated from the societal perspective using economic costing methods. Total annual provider's direct costs for each input to surgery were calculated and apportioned appropriately to different cataract surgery techniques using a 'micro-costing approach'. The patient's direct and indirect costs for each procedure were calculated by interviewing staff and patients and by using assumptions about prices for relevant cost items such as transportation, food, medicine, spectacles and economic productivity loss.

RESULTS

Average provider's direct costs were highest for PHACO procedures (25.55 US dollars) compared to MSICS (17.03 US dollars) and ECCE-IOL (16.25 US dollars). The difference can be attributed to the cost of equipment and materials. Average direct and indirect patient costs were highest for ECCE-IOL (19.85 US dollars), while the costs for PHACO and MSICS were identical (12.37 US dollars). ECCE-IOL had the highest total costs and MSICS had the lowest total costs from the societal perspective.

CONCLUSIONS

Our results suggest that MSICS may have a lower societal cost than other options. Government and NGO hospitals providing cataract surgeries should invest in regular cost analyses, reviews of the literature on effectiveness, and formal cost-effectiveness analyses in order to plan economically efficient interventions. Considering the small incremental cost for providers (less than 1 US dollar), improved outcomes, and lower patient costs, we also believe that MSICS is an important technique to use in efforts to eliminate cataract blindness in India and this result may be generalised to other developing countries.

A 7 gene signature identifies the risk of developing cirrhosis in patients with chronic hepatitis C

Clinical factors such as age, gender, alcohol use, and age-at-infection influence the progression to cirrhosis but cannot accurately predict the risk of developing cirrhosis in patients with chronic hepatitis C (CHC). The aim of this study was to develop a predictive signature for cirrhosis in Caucasian patients. All patients had well-characterized liver histology and clinical factors; DNA was extracted from whole blood for genotyping. We validated all significant markers from a genome scan in the training cohort, and selected 361 markers for the signature building. Using a "machine learning" approach, a signature consisting of markers most predictive for cirrhosis risk in Caucasian patients was developed in the training set (N = 420). The Cirrhosis Risk Score (CRS) was calculated to estimate the risk of developing cirrhosis for each patient. The CRS performance was then tested in an independently enrolled validation cohort of 154 Caucasian patients. A CRS signature consisting of 7 markers was developed for Caucasian patients. The area-under-the-ROC curves (AUC) of the CRS was 0.75 in the training cohort. In the validation cohort, AUC was only 0.53 for clinical factors, increased to 0.73 for CRS, and 0.76 when CRS and clinical factors were combined. A low CRS cutoff of <0.50 to identify low-risk patients would misclassify only 10.3% of high-risk patients, while a high cutoff of >0.70 to identify high-risk patients would misclassify 22.3% of low-risk patients.

CONCLUSION

CRS is a better predictor than clinical factors in differentiating high-risk versus low-risk for cirrhosis in Caucasian CHC patients. Prospective studies should be conducted to further validate these findings.

Outcomes of high volume cataract surgeries in a developing country

AIM

To analyse the outcome of high volume cataract surgery in a developing country, community based, high volume eye hospital.

METHODS

In a non-comparative interventional case series, the authors reviewed the surgical outcomes of 593 patients with cataract operated upon by three high volume surgeons on six randomly selected days. There were 318 female (54%) and 275 male (46%) patients. Their mean age was 59.57 (SD 10.13) years. The majority of the patients underwent manual small incision cataract surgery (manual SICS). Extracapsular cataract extraction with posterior chamber intraocular lens (ECCE-PCIOL) and intracapsular cataract extraction (ICCE) were also done on a few patients as clinically indicated.

RESULTS

Best corrected visual acuity of >or=6/18 was achieved in 94% of the 520 patients who could be followed up on the 40th postoperative day (88% follow up rate). Intraoperative and immediate postoperative complications as defined by OCTET occurred in 11 (1.9%) and 75 (12.6%) patients, respectively. Average surgical time of 3.75 minutes per case (16-18 cases per hour) was achieved. Statistically significant risk factors for outcomes were found to be age >60, sex, and surgeon.

CONCLUSION

High volume surgery using appropriate techniques and standardised protocols does not compromise quality of outcomes.

The effect of age and gender upon symptoms and surgical outcomes in carpal tunnel syndrome

There is conflicting evidence regarding the effectiveness of carpal tunnel release in older patients. This is a prospective study which evaluates the impact of age and gender upon symptoms, self-reported disability and surgical outcome in a series of 97 patients with carpal tunnel syndrome. Symptom severity, hand function and patient satisfaction were assessed using the Boston Carpal Tunnel Questionnaire and the Patient Evaluation Measure. A statistical correlation of age and gender with symptoms, hand function and surgical outcome was performed with questionnaires administered before open carpal tunnel decompression and 6 months after surgery. Women reported greater pre-operative symptoms and disability than men, but there was no gender-related difference in surgical outcome or patient satisfaction. There was no difference in surgical outcome between patients 60 and 70 years of age and younger patients. The majority of patients over the age of 70 reported an improvement in symptoms and function, but they were less satisfied with their treatment than younger patients. Some patients had problems with persistent numbness and loss of dexterity following surgery. The outcome of carpal tunnel release in terms of improvement in the symptom and functional scores is sufficient to justify surgery in the elderly, but surgical outcomes are less predictable than in younger patients and we recommend that this is explained to them when obtaining consent for surgery.

Enhanced catalytic and conformational stability of Atlantic cod trypsin upon neoglycosylation

The applicability of psychrophilic enzymes is limited because of their lower thermodynamic stability in spite of their higher catalytic rate. In this study, we have shown that the thermodynamic stability of the psychrophilic Atlantic cod trypsin could be enhanced appreciably by covalent chemical modification with oxidized sucrose polymer without affecting its hydrolytic activity. The acquired stability of cod trypsin was found to be on par with the mesophilic porcine trypsin.