Observation of chiral surface excitons in a topological insulator Bi2Se3.

The protected electron states at the boundaries or on the surfaces of topological insulators (TIs) have been the subject of intense theoretical and experimental investigations. Such states are enforced by very strong spin-orbit interaction in solids composed of heavy elements. Here, we study the composite particles-chiral excitons-formed by the Coulomb attraction between electrons and holes residing on the surface of an archetypical 3D TI, [Formula: see text] Photoluminescence (PL) emission arising due to recombination of excitons in conventional semiconductors is usually unpolarized because of scattering by phonons and other degrees of freedom during exciton thermalization. On the contrary, we observe almost perfectly polarization-preserving PL emission from chiral excitons. We demonstrate that the chiral excitons can be optically oriented with circularly polarized light in a broad range of excitation energies, even when the latter deviate from the (apparent) optical band gap by hundreds of millielectronvolts, and that the orientation remains preserved even at room temperature. Based on the dependences of the PL spectra on the energy and polarization of incident photons, we propose that chiral excitons are made from massive holes and massless (Dirac) electrons, both with chiral spin textures enforced by strong spin-orbit coupling. A theoretical model based on this proposal describes quantitatively the experimental observations. The optical orientation of composite particles, the chiral excitons, emerges as a general result of strong spin-orbit coupling in a 2D electron system. Our findings can potentially expand applications of TIs in photonics and optoelectronics.

INFLUENCE OF THE DURATION OF DIABETES AND VIBRATION PERCEPTION THRESHOLD ON THE SEVERITY OF ERECTILE DYSFUNCTION IN PATIENTS WITH TYPE 2 DIABETES MELLITUS.

Background: Erectile dysfunction(ED) in men is a frequent under-reported complication of diabetes mellitus, which is becoming significant health problem worldwide. Aims: The study aims to determine the prevalence and risk factors for development of ED in North Indian patients with type 2 diabetes mellitus. Methods: We used international index of erectile function (IIEF-5) for the assessment of ED in 796 patients with type 2 diabetes mellitus. We recorded the age, duration of diabetes, glycemic status, body mass index, diabetes medications, microvascular and macrovascular complications. Results: The mean age of patients in the study was 49.38 ± 9.52 years. The prevalence of ED in patients with type 2 diabetes mellitus was 79.4%. Logistic regression analysis revealed that age, body mass index, glycemic control, insulin therapy, retinopathy and nephropathy was not significantly associated with erectile dysfunction in patients with type 2 diabetes mellitus. Duration of diabetes (OR = 1.054, 95% CI 1.007 to 1.102, P=0.023) and vibration perception threshold (OR = 1.071, 95% CI 1.042 to 1.102, P=0.000) were identified as key risk factors for development of ED. Conclusion: Duration of diabetes and peripheral neuropathy emerged as significant risk factors for development of severe erectile dysfunction.

Radiology of anal and lower rectal cancers.

Lower rectal and anal cancers are distinct from neoplasms involving rest of the rectum. These are relatively difficult to manage owing to important relationships with the sphincter muscles. Involvement of the latter portends a poorer prognosis and increased chance of recurrence. Lymphatic drainage of these tumours is into the systemic circulation and the exact set of lymph nodes involved depends on the precise location of the tumour. The role of imaging includes assessment of local invasion, infiltration of adjacent pelvic organs, assessment of locoregional lymphatic spread and metastasis, post-chemoradiation restaging as well as post-treatment surveillance.

Screening for second malignancies in mycosis fungoides: non-Hodgkin lymphoma, Hodgkin lymphoma, lung cancer, bladder cancer and melanoma.

BACKGROUND: Patients with mycosis fungoides (MF) are at increased risk of developing non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL), lung cancer, bladder cancer and melanoma. The characteristics of patients developing these malignancies have not been specifically delineated. In addition, there are no established guidelines for screening MF patients for second malignancies. MATERIALS/METHODS: We identified 742 patients with MF who developed second malignancies in the Surveillance Epidemiology and End Result-18 database. RESULTS: The majority of second malignancy patients were white and male, mean age 55-67 years at diagnosis of MF, and mean age 61-72 years at diagnosis of second malignancy. The majority of patients diagnosed with second malignancies had early stage MF. MF patients with NHL, lung cancer, and bladder cancer tended to be diagnosed at earlier stages of the second malignancy than patients without MF and demonstrated better 5-year overall survival. There was no improvement in stage at diagnosis or survival for MF patients who were diagnosed with melanoma compared to patients without MF. CONCLUSIONS: Improvements in survival in MF/NHL, MF/lung cancer and MF/bladder cancer patients may reflect differences in disease biology secondary to having MF or the importance of increased contact with the healthcare system. MF/melanoma data suggest that patients require regular pigmented-lesion-focused skin examinations. Tools for screening include regular lymph node examinations, pigmented-lesion-focused examinations and detailed review of systems questions. Smoking cessation counseling is key intervention in this population, as is ensuring that all age- and sex-specific cancer screenings are up-to-date (e.g. lung cancer screening, mammography, and colonoscopy). The utility of regular imaging for second malignancy screening and lab testing such as routine urinalysis requires additional study and expert consensus.

High burden of cardiometabolic risk factors in spouses of Indian women with hyperglycaemia in pregnancy.

AIM: To evaluate the burden and association of cardiometabolic risk factors in the spouses of women with and without hyperglycaemia in pregnancy. METHODS: Women with (n = 204) and without (n = 197) hyperglycaemia in pregnancy, along with their spouses, participated in this cross-sectional study. The hyperglycaemia in pregnancy group included women with gestational diabetes and diabetes in pregnancy. A detailed questionnaire was completed for all participants (men and women), documenting relevant personal and medical history, along with biochemical investigations (men). RESULTS: A total of 401 couples were evaluated at the time point during the pregnancy of 24.7 ± 5.2 gestational weeks (mean ± sd). Dysglycaemia (prediabetes or diabetes), overweight/obesity (BMI ≥25 kg/m2 ) and metabolic syndrome were detected in 120 (58.9%), 123 (60.3%) and 98 spouses (48.3%) of women with hyperglycaemia in pregnancy, respectively. In the fully adjusted model, an increased risk of dysglycaemia [odds ratio 1.43 (95% CI 0.95-2.17); P = 0.088], overweight/obesity [odds ratio 1.49 (95% CI 0.98-2.27); P = 0.064] and metabolic syndrome [odds ratio 2.00 (95% CI 1.30-3.07); P = 0.001] was seen in the spouses of women with hyperglycaemia in pregnancy. The prevalence of these metabolic conditions was higher in spouses of women with diabetes in pregnancy compared to spouses of women with gestational diabetes mellitus. CONCLUSIONS: A high burden of cardiometabolic risk factors was observed in the spouses of women with hyperglycaemia in pregnancy. The opportunity provided by pregnancy could be used by the healthcare system not only to improve the health of the woman and her offspring, but also her spouse.

Mycosis fungoides: developments in incidence, treatment and survival.

BACKGROUND: Prior studies have demonstrated improved disease-specific survival of mycosis fungoides (MF) patients over the last 50 years. OBJECTIVE: To analyse patterns of survival and incidence from 1973 to 2016 and determine whether apparent improvements in MF-specific survival are due to lead-time bias rather than improvements in treatment. METHODS: We performed an analysis of 10 155 patients diagnosed with MF from 1973 to 2016 in the United States cancer registries of SEER-18. We also performed a literature review of papers including stage data for unselected populations of MF patients prior to 2000. RESULTS: Incidence of MF increased from 3.0 per million person-years in the 1970s to 5.9 in the 2010s. For all cohorts, non-Hodgkin lymphoma (including MF) was the leading cause of death. Survival analysis demonstrated marked improvement in disease-specific and overall survival from the 1970s to 2010s. Based on systematic review of the literature, 32%-73% of patients diagnosed prior to 2000 were diagnosed with early-stage disease, as opposed to 81% of patients in the SEER 2000-2016 cohort (P < 0.035 for all cohorts). CONCLUSIONS: Although there have been improvements in MF-related survival over the last 50 years, these may reflect improvements in our ability to diagnose early-stage disease rather than improved treatment.

Axillary tumour burden in women with one abnormal node on ultrasound compared to women with multiple abnormal nodes.

AIM: To determine if the number of abnormal nodes seen on preoperative axillary ultrasound (AUS) is a predictor of the number of positive nodes at histology for women with needle-biopsy-proven positive nodes. MATERIALS AND METHODS: This prospective multicentre cohort study included consecutive patients with early breast cancer who had needle-biopsy-proven positive nodes on AUS and underwent axillary lymph node dissection (ALND) between October 2015 and July 2016. The number of abnormal nodes at preoperative AUS was recorded by breast radiologists or radiographers. RESULTS: One hundred and twenty-three patients were included in the study. The median age of the women was 62 (range 30-93) years. Fifty-four of the 123 (44%) women had one abnormal node, whereas 69 (56%) had multiple abnormal nodes on AUS. Forty of the 123 (33%) women had two or fewer nodes with metastases at histology after ALND. Tumours ≤20 mm (p<0.001) and one abnormal node on AUS (p<0.001) were associated with two or fewer nodes with metastases at ALND. Both remained significant in logistic regression analysis. The likelihood of at least three metastases based on the combination of these two factors had 95% sensitivity (79 of 83), 35% specificity (14 of 40), a negative predictive value of 78% (14 of 18), and a positive predictive value of 75% (79 of 105). CONCLUSION: Among women with needle-biopsy-proven positive nodes, around three in four women (78%) with an invasive tumour ≤2 cm and one abnormal node on AUS have two or fewer positive nodes at ALND. These women are overtreated by upfront ALND and can be offered sentinel node biopsy (SNB).

Multi-organ IgG4-related disease: Demystifying the diagnostic enigma.

IgG4-related disease (IgG4-RD) is a multisystemic mass forming immune-mediated disease entity, commonly creating confusion and diagnostic challenges. We present a case of a 25-year-old female who presented with bilateral orbital masses, lymphadenopathy, paraspinal and renal masses, which clinicoradiologically simulated lymphoma. The lymph node biopsy revealed interfollicular sheets of plasma cells creating confusion with Castleman's disease and marginal zone lymphoma. The orbital biopsy revealed ductular destruction, periductular plasma cells, and fibrosis, mimicking Sjogren's syndrome and Castleman's disease. However, the correlation of the clinical features with histopathological findings, IgG4 immunopositivity, and serum studies helped in clinching the diagnosis. This case presents an uncommon combination of clinical features infrequently reported in literature. Furthermore, and more importantly, it highlights the need to keep a differential of IgG4-RD in mind, to aid early and correct treatment of the disease.

Guiding the Child's Teeth with Class III Dental Malocclusion into Correct Occlusion: A Clinician's Parenting.

Pediatric dentists are often the first ones to be consulted for the presence of an anterior cross bite in the primary dentition. The condition requires an early interception to avoid progressive dentoalveolar and skeletal changes. The management, however, poses unique challenges in terms of young age of the child, correct choice of appliance and unpredictability of the response to treatment due to inability to ascertain the inherent growth potential. It is very important therefore for the specialist, to be able to recognize the early signs of a developing class III malocclusion tendency and also know the basic details of successful management of such cases. The following article describes the appropriateness of appliance choice for a case of incisor cross bite in primary dentition using different appliances based on their varied clinical presentations.

Axillary tumour burden in women with a fine-needle aspiration/core biopsy-proven positive node on ultrasonography compared to women with a positive sentinel node.

BACKGROUND: The sensitivity of axillary ultrasonography (AUS) has increased in recent years, enabling detection of even low-volume axillary nodal metastases. The aim here was to evaluate the axillary tumour burden in women with a fine-needle aspiration/core biopsy-proven positive node on AUS and in those with a positive sentinel node biopsy (SNB). METHODS: This retrospective cohort study included all patients with early breast cancer who had AUS and axillary lymph node dissection (ALND) between 2011 and 2014. RESULTS: A total of 332 patients who had ALND were eligible for the study, 191 (57·5 per cent) in the AUS-positive group and 141 (42·5 per cent) in the SNB-positive group. Patients in the AUS-positive group were older at diagnosis (P = 0·018), more likely to have larger tumours (P = 0·002), higher tumour grade (P = 0·005), positive human epidermal growth factor 2 status (P = 0·015), and negative oestrogen receptor status (P < 0·001). The AUS-positive group also had a larger number of lymph nodes with macrometastases (P < 0·001) and were more likely to have extranodal invasion (P < 0·001). In the AUS-positive group, 40·3 per cent of patients (77 of 191) had only one or two nodes with macrometastases identified at histology after ALND. Tumour size no larger than 20 mm, invasive ductal or lobular histology and breast-conserving surgery were associated with the presence of two or fewer macrometastases at ALND. Only tumour size and tumour histology remained significant in multiple logistic regression analysis. CONCLUSION: Patients with AUS-detected metastases had a higher axillary tumour burden than those with SNB-detected metastases. Around 40 per cent of patients with AUS-detected nodal disease had one or two nodes with macrometastases and were thus overtreated by ALND.

Oral Midazolam Sedation For Uncooperative Children In Outpatient Paedodontics: Time For Reappraisal.

Sedation is frequently desired to facilitate dental procedures in uncooperative paediatric patients. Oromucosal Midazolam sedation is a popular choice among paediatric dentists world wide due to its many advantages such as ease of administration, good efficacy, presence of reversal agents and a wide margin of safety. On the other hand, many investigators have reported that midazolam sedation may not be successful for carrying out all types of dental procedures. This may be attributed to diverse nature of various treatment plans coupled with the extent of behavioural changes in the child and operator's experience. Due to the heterogeneity involved in treatment of paediatric dental procedures, the specific indications for oral midazolam use that ensure its success rate, probably need to be defined. This may enable the clinicians to have a convenient and quicker option for managing the cases rather than facing sedation failure or at times, ending up giving general anaesthetics. This article therefore brings forth the possible causes of midazolam sedation failure and proposes a 'case selection criterion'.

Pediatric Dental Sedation Research: Where Do We Stand Today?

Despite the voluminous literature addressing the safety and efficacy of various sedative agents in the pediatric dental setting, the quality literature to form evidence based pediatric dental sedation practice is not available. Our search through PUBMED showed that during 1985-2012, a total of 184 original research papers on pediatric dental sedation were reported, and midazolam clearly dominated with 88 trials on this agent. Despite these large numbers of papers, Cochrane Review was able to pool a weak evidence in favor of midazolam. Data pooling from five heterogeneous high risk of bias trials showed that oral midazolam is associated with more cooperative behavior when compared to a placebo. Further, a very weak evidence regarding efficacy of nitrous oxide was collected from two trials, which could not be pooled. These findings draw attention to the need to address the shortcomings in the current state of pediatric dental sedation research. The present article has been focused on the current status of pediatric dental sedation research, and the limitations in the current research methodology. This paper also suggests recommendations for future research in the field of pediatric dental sedation.

Structure and functional investigation of ligand binding by a family 35 carbohydrate binding module (CtCBM35) of ß-mannanase of family 26 glycoside hydrolase from Clostridium thermocellum.

Functional attributes of recombinant CtCBM35 (family 35 carbohydrate binding module) of ß-mannanase of family 26 Glycoside Hydrolase from Clostridium thermocellum were deduced by biochemical and in silico approaches. Ligand-binding analysis of expressed CtCBM35 analyzed by affinity-gel electrophoresis and fluorescence spectroscopy exhibited association constants Ka ~ 1.2·10(5) and 3.0·10(5) M(-1) with locust bean galactomannan and mannotriose, respectively. However, CtCBM35 showed low ligand-binding affinity with insoluble ivory nut mannan with Ka of 5.0·10(-5) M(-1). Unfolding transition analysis by fluorescence spectroscopy explained the conformational changes of CtCBM35 in the presence of guanidine hydrochloride (5 M) and urea (6.25 M). This explained that CtCBM35 has good conformational stability and requires higher free energy of denaturation to invoke unfolding. The three-dimensional (3-D) model of CtCBM35 from C. thermocellum generated by Modeller9v8 displayed predominance of ß-sheets arranged as ß-jelly-roll fold. The secondary structure of CtCBM35 by PredictProtein showed the presence of two α-helices (3%), 12 ß-sheets (45%), and 15 random coils (52%). Secondary structural element analysis of cloned, expressed, and purified recombinant CtCBM35 by circular dichroism also corroborated the in silico predicted secondary structure. Multiple sequence alignment of CtCBM35 showed conserved residues (Tyr123, Gly124, and Phe125), which are commonly observed in mannan specific CBMs. Docking analysis of CtCBM35 with manno-oligosaccharide displayed the involvement of Tyr26, Gln29, Asn43, Trp66, Tyr68, Leu69, Arg76, and Leu127 residues, making polar contact with the ligand molecules. Ligand docking analysis of CtCBM35 exhibiting higher binding affinity with mannotriose and galactomannan (Man-Gal-Man moiety) substantiated the affinity binding and fluorescence results, displaying similar values of Ka.

Delayed replantation of avulsed tooth with 15-hours extra-oral time: 3-year follow-up.

BACKGROUND: Avulsion is one of the most serious injuries of the tooth which is most commonly seen in young children and occurs in the upper front teeth. Immediate transplantation of the avulsed tooth is recommended treatment and results in good prognosis although this may not be always possible. CASE REPORT: The present case highlights the 3-year follow-up of delayed replantation (after 15h) of maxillary central incisor which was avulsed due to trauma. The complications seen in the present case were ankylosis and inflammatory resorption, but clinically the tooth was asymptomatic and maintains the esthetics of the individual signifying the importance of delayed replantation even after prolonged extra-oral time. CLINICAL IMPLICATIONS AND CONCLUSION: Although complications like ankylosis or root resorption may be unavoidable, delayed replantation of avulsed tooth may be a good alternative to prosthesis (implant or fixed partial denture) till the growth is completed due to preservation of the alveolar bone and psychological benefit to the patient. Also efforts should be made to educate and update children, teachers and parents regarding management of avulsed tooth at accident site and also the dentists regarding its management in dental office.

Results of a national training programme in sentinel lymph node biopsy for breast cancer.

BACKGROUND: New Start, a structured, validated, multidisciplinary training programme in sentinel lymph node biopsy (SLNB), was established to allow the introduction and rapid transfer of appropriate knowledge and technical skills to ensure safe and competent practice across the UK. METHODS: Multidisciplinary teams attended a theory/skills laboratory course, following which they performed 30 consecutive SLNBs, either concurrently with their standard axillary staging procedure (training model A) or as stand-alone SLNB (training model B). SLNB was performed according to a standard protocol using the combined technique of isotope ((99m) Tc-labelled albumin colloid) and blue dye. An accredited New Start trainer mentored the first five procedures in the participant's hospital, or all 30 if stand-alone. Validation standards for model A and B were a localization rate of at least 90 per cent. In addition, for model A only, in which a minimum of ten patients were required to be node-positive, a false-negative rate (FNR) of 10 per cent or less was required. RESULTS: From October 2004 to December 2008, 210 SLNB-naive surgeons, in 103 centres, performed 6685 SLNB procedures. The overall sentinel lymph node (SLN) localization rate was 98·9 (95 per cent confidence interval 98·6 to 99·1) per cent (6610 of 6685) and the FNR 9·1 (7·9 to 10·5) per cent (160 of 1757). The FNR was related to nodal yield, ranging from 14·8 per cent for one node and declining to 9·7, 6·6, 4·7 and 4·1 per cent for two, three, four and more than four SLNs respectively. No learning curve was identified for localization or FNR. CONCLUSION: The programme successfully trained a wide range of UK breast teams to perform safe SLNB and suggested that a standard injection protocol and structured multidisciplinary training can abolish learning curves.

Structural characterization of enzymatically synthesized dextran and oligosaccharides from Leuconostoc mesenteroides NRRL B-1426 dextransucrase.

Leuconostoc mesenteroides NRRL B-1426 dextransucrase synthesized a high molecular mass dextran (>2 × 10(6) Da) with ~85.5% α-(1→6) linear and ~14.5% α-(1→3) branched linkages. This high molecular mass dextran containing branched α-(1→3) linkages can be readily hydrolyzed for the production of enzyme-resistant isomalto-oligosaccharides. The acceptor specificity of dextransucrase for the transglycosylation reaction was studied using sixteen different acceptors. Among the sixteen acceptors used, isomaltose was found to be the best, having 89% efficiency followed by gentiobiose (64%), glucose (30%), cellobiose (25%), lactose (22.5%), melibiose (17%), and trehalose (2.3%) with reference to maltose, a known best acceptor. The ß-linked disaccharide, gentiobiose, showed significant efficiency for oligosaccharide production that can be used as a potential prebiotic.

Functional and structural characterization of family 6 carbohydrate-binding module (CtCBM6A) of Clostridium thermocellum α-L-Arabinofuranosidase.

The gene encoding the family 6 carbohydrate-binding module (CtCBM6A) from Clostridium thermocellum, cloned in pET-21a(+) expression vector, was overexpressed using Escherichia coli BL-21(DE3) cells and purified by immobilized metal-ion affinity chromatography. SDS-PAGE analysis of the recombinant CtCBM6A showed molecular size of approximately 15 kDa. Ligand-binding analysis of CtCBM6A with rye arabinoxylan and oat spelt xylan by affinity gel electrophoresis showed low affinity for these ligands (Ka of 40 and 26 liter/g, respectively), and analysis by fluorescence spectroscopy (Ka of 33 and 15 liter/g, respectively) corroborated lower binding affinity with the above soluble ligands. However, CtCBM6A displayed significantly higher ligand-binding affinity with insoluble wheat arabinoxylan with equilibrium association constant Ka of 230 M(-1) and binding capacity (N0) of 11 µmole/g. The protein melting curve of CtCBM6A displayed a peak shift from 53 to 58°C in the presence of Ca2+, indicating that Ca2+ imparts thermal stability to the CtCBM6A structure. Homology modeling of CtCBM6A revealed a characteristic ß-sandwich core structure. The Ramachandran plot of CtCBM6A showed 89% of the residues in the most favorable region, 10% in additionally favored region, and 1% in generously allowed region, indicating that CtCBM6A has a stable conformation.

Spontaneous regression of a congenital epulis in a newborn.

A 3 day old girl presented with lobulated mass protruding from her mouth. The mass was clinically diagnosed as a congenital epulis. The child had no airway obstruction and was able to feed well. A conservative treatment was proposed with monthly follow up appointments to monitor the lesion. After 10 months the lesion completely regressed and the eruption of maxillary anterior teeth remained unaffected