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.