A rare diagnosis of Langerhans cell histiocytosis made on thyroid histology with coexisting papillary thyroid cancer and AVP deficiency

Summary

A 48-year-old Asian male, presented to the hospital for an elective total thyroidectomy in the context of 6.3 cm thyroid nodule. The fine needle aspiration cytology of the nodule confirmed papillary thyroid cancer (PTC) with some atypical histiocytes. He has a history of idiopathic arginine vasopressin deficiency (AVP-D) and has been taking oral DDAVP 100 µg daily, self-adjusting the dose based on thirst and polyuria. Additionally, he also has a history of recurrent spontaneous pneumothorax. His total thyroidectomy was aborted due to significant intraoperative bleeding, and his admission was further complicated by post-operative hyponatraemic seizure. Thyroid histology revealed the diagnosis of Langerhans cell histiocytosis (LCH), and further investigation with contrast CT demonstrated multi-organ involvement of the thyroid, lungs, and bones.

Learning points

Langerhans cell histiocytosis (LCH) is a condition that can affect one or more organ systems, including the pituitary, where it can present as AVP deficiency. Strict monitoring of fluid balance, as well as serial monitoring of serum sodium, is essential in all patients with AVP-D in the perioperative setting. Iatrogenic hyponatraemic seizure is an uncommon but serious complication of DDAVP treatment in hospitalised patients with AVP-D. DDAVP dosing must be carefully monitored. LCH with multisystem involvement is an important mimic for metastatic conditions, and histological diagnosis is essential to guide treatment and prognosis. Although LCH without bone marrow involvement is unlikely to increase the risk of bleeding, its effect on tissue integrity may make surgery more challenging. BRAF-V600E mutation is an important driver mutation and a potential therapeutic target in the treatment of LCH.

Temperature dependent structural properties of Mn1.90M0.10O3(M = Cr and Fe)

The polycrystalline samples of Mn1.90Cr0.10O3(MCO) and Mn1.90Fe0.10O3(MFO) have been investigated for their temperature dependent magnetic and structural properties. The Cr and Fe substitutions have significant effect on the magnetic and structural properties of Mn2O3. Like pristine Mn2O3, the Cr and Fe substituted samples MCO and MFO also exhibit two antiferromagnetic transitions; one at ∼77 K, ∼80 K, respectively and another at ∼40 K. Our room temperature synchrotron x-ray powder diffraction (SXRD) results confirm that both the MCO and MFO samples crystallize in cubic symmetry. The temperature dependent SXRD results demonstrate the cubic to orthorhombic structural transition for the studied samples. The pristine Mn2O3shows cubic to orthorhombic transition around 310 K, whereas this structural transition shifted towards lower temperature side with these substitutions i.e. around 240 K for MCO and 260 K for MFO. Interestingly, the centrosymmetricPcabto non-centrosymmetricPca21change in symmetry is also resolved at the ferroelectric ordering temperature for MCO.

Enhanced external counter pulsation therapy in patients with symptomatic and severe intracranial steno-occlusive disease: a randomized clinical trial protocol

Intracranial stenosis is prevalent among Asians and constitutes a common cause of cerebral ischemia. While the best medical therapy carries stroke recurrence rates in excess of 10% per year, trials with intracranial stenting have been associated with unacceptable peri-procedural ischemic events. Cerebral ischemic events are strongly related to the severity of intracranial stenosis, which is high in patients with severe intracranial stenosis with poor vasodilatory reserve. Enhanced External Counter Pulsation (EECP) therapy is known to improve myocardial perfusion by facilitating the development of collateral blood vessels in the heart. In this randomized clinical trial, we evaluate whether EECP therapy may be useful in patients with severe stenosis of intracranial internal carotid (ICA) or middle cerebral artery (MCA). The review of literature, methods of evaluation, status of currently used therapeutic approaches, and trial protocol have been presented.

Clinical trial registration

ClinicalTrials.gov, Identifier: NCT03921827.

Comparative study of the short-range structure of α-V2O5, α-TeO2 and xV2O5-(100 - x)TeO2 glasses using X-ray diffraction, Rietveld analysis and reverse Monte Carlo simulations

Vanadium-tellurite glasses, tetragonal TeO₂ and orthorhombic V₂O₅ crystalline samples were characterized for their atomic structure properties by synchrotron X-ray diffraction, pair distribution function analysis, reverse Monte Carlo simulations (RMC) and Rietveld analysis. The pair correlation function, G(r), of V₂O₅ shows the first peak at 1.61 Å. G(r) of TeO₂ shows three peaks at 1.57, 2.13 and 2.88 Å due to Te-O linkages of three different lengths, whereas the Te-Te atomic pair correlation shows a peak at 3.85 Å. The average coordination number of V with O in crystalline V₂O₅ is 4.39 while that of Te with O in crystalline TeO₂ is 3.71. G(r) of the vanadium tellurite glass shows the first peak at 1.90 Å due to overlapping Te-O and V-O atomic pair correlations. The RMC analysis on diffraction data of glasses found that the V-O coordination number is in the range 5.27-5.59 and the Te-O coordination number is 5.39-5.67. However, it is found that these coordination numbers cannot be clearly defined due to short-range disorder.

Perceived stigma among diabetic patients and their caregivers: a review

AIMS

Considerable number of studies in the existing literature indicate the existence of stigma related to many diseases, disabilities, and disorders, but less attention has been given to diabetes-related stigma. This narrative review of literature aims to explore the existence of stigma surrounding type 1 diabetes mellitus (T1DM).

METHODS

Literature were searched using search engines, Google Scholar, PubMed, and Scopus electronic databases published from year 2000 to 2020. Both qualitative and quantitative studies focusing on the stigma associated with T1DM were included. A total of 21 articles met the inclusion criteria. Thematic analysis of collected research material was done.

RESULTS

Results provided substantial evidence that stigma associated with T1DM was experienced by T1DM patients and their caregivers at some point in their lives and it had affected their lives in different domains such as difficulty finding a spouse, discrimination at employment opportunities, educational institutions, management of disease, being misjudged as a druggie, poor quality of life of the patient and caregiver, depressive symptoms among parents of patients, constant worrying of their child's disease management, and so on.

CONCLUSION

Stigma related to T1DM is experienced by individuals suffering from it, and it is widespread. It not only affects the sufferers but their loved ones also. To reduce and cope-up with stigma, there is a need to increase public education and awareness at a mass level. Further research and awareness will serve to build our understanding of the experience of diabetes-related stigma.

Angiomatoid Fibrous Histiocytoma with EWSR1 Rearrangement in an Unusual Location

Introduction/Objective

Angiomatoid fibrous histiocytoma (AFH) is a rare mesenchymal neoplasm most often arising in the superficial extremities of children and young adults. AFH can mimic clinical, histologic, and radiologic presentation of several different tumors, therefore diagnosis can be quite challenging.

Methods/Case Report

We report the case of a 32-year-old woman with no significant medical history who presented with three days of right upper quadrant pain. Radiologic studies showed a 2.3 centimeter right lower lobe soft tissue nodule abutting the right lower lobe bronchus.

Results (if a Case Study enter NA)

Subsequent lobectomy with mediastinal lymph node dissection was performed. Histopathologic examination of the right middle and lower lobes revealed a fibrohistiocytic appearing neoplasm with bland nuclear features and brisk associated lymphoplasmacytic and histiocytic infiltrate. Given the suspicion for AFH, fluorescent in situ hybridization for EWSR1 and FUS were performed at an outside facility with detection of EWSR1 gene rearrangement supporting the diagnosis of AFH.

Conclusion

AFH is a rare soft tissue neoplasm that is often indolent but intermediate in potential given the rare possibility of metastasis. While most common in superficial extremities, increasing unusual anatomic sites are being reported. Histologically, the tumor can show a spectrum of morphologic patterns including nodules to sheets of often monomorphic bland, spindle or ovoid cells in an inflammatory background and with associated fibrous pseudocapsule. Three characteristic chromosomal translocations have been identified: EWSR1-CREB1, EWSR1-ATF1 and FUS- ATF1. Treatment is wide surgical excision or radiotherapy if unresectable. The differential diagnosis can be broad with a spectrum from reactive, benign lesions to malignant neoplasms, including a variety of sarcomas.

Structural correlations in the enhancement of ferroelectric property of Sr doped BaTiO3

The effect of Sr doping in BaTiO3(BTO) with nominal compositions Ba0.80Sr0.20TiO3(BSTO) have been explored on its structural, lattice vibration, dielectric, ferroelectric and electrocaloric properties. The temperature dependent dielectric results elucidate the enhancement in dielectric constant and exhibit three frequency independent transitions around 335, 250 and 185 K, which are related to different structural transitions. All these transitions occur at lower temperature as compared with pristine BTO, however; remnant electric polarization (Pr) of BSTO is much higher than in BTO. The value ofPris ∼5μC cm-2at room temperature and the maximumPr∼ 8μC cm-2is observed at tetragonal to orthorhombic and orthorhombic to rhombohedral transitions. The electro-caloric effect shows the maximum adiabatic change in temperature ΔT∼ 0.24 K at cubic to tetragonal transition. The temperature dependent synchrotron x-ray diffraction and Raman results show correlations betweenPr, crystal structure and lattice vibrations. Our results demonstrate the enhancement in ferroelectric properties of BTO with Sr doping. The origin of the enhancement in ferroelectric property is also discussed in correlations with the appearance of superlattice peak around room temperature due to TiO6octahedral distortion. These enhanced properties would be useful to design lead free high quality ferroelectric and piezoelectric materials.

Direct hybridization gap from intersite and onsite electronic interactions in CeAg2Ge2

Electronic and crystal structure studies are presented to describe the role of intersite and onsite interactions for antiferromagnetic ordering in CeAg2Ge2. The crystal structure showed a prominent magnetovolume effect with anomalous negative thermal expansion at low temperature as a consequence of itinerant electron magnetism. The direct hybridization gap with a V-shaped band observed in the angle resolved photoemission data at room temperature, indicates that spin polarized quasiparticle states exist in the gapped region. Valence band broadening and enhanced localization effects at low temperature indicate strong hybridization of the valence orbitals of Ce atoms with the near neighbor Ge atoms. We find that the intersite interaction between the Ce atoms at high temperature stabilizes the onsite interaction at low temperature that leads to the spin density wave type antiferromagnetism in CeAg2Ge2.

Combined pathologic-genomic algorithm for early-stage breast cancer improves cost-effective use of the 21-gene recurrence score assay

Background

The 21-gene recurrence score (RS) (Oncotype DX®; Genomic Health, Redwood City, CA) partitions hormone receptor positive, node negative breast cancers into three risk groups for recurrence. The Anne Arundel Medical Center (AAMC) model has previously been shown to accurately predict RS risk categories using standard pathology data. A pathologic-genomic (P-G) algorithm then is presented using the AAMC model and reserving the RS assay only for AAMC intermediate-risk patients.

Patients and methods

A survival analysis was done using a prospectively collected institutional database of newly diagnosed invasive breast cancers that underwent RS assay testing from February 2005 to May 2015. Patients were assigned to risk categories based on the AAMC model. Using Kaplan-Meier methods, 5-year distant recurrence rates (DRR) were evaluated within each risk group and compared between AAMC and RS-defined risk groups. Five-year DRR were calculated for the P-G algorithm and compared with DRR for RS risk groups and the AAMC model's risk groups.

Results

A total of 1268 cases were included. Five-year DRR were similar between the AAMC low-risk group (2.7%, n = 322) and the RS < 18 low-risk group (3.4%, n = 703), as well as between the AAMC high-risk group (22.8%, n = 230) and the RS > 30 high-risk group (23.0%, n = 141). Using the P-G algorithm, more patients were categorized as either low or high risk and the distant metastasis rate was 3.3% for the low-risk group (n = 739) and 24.2% for the high-risk group (n = 272). Using the P-G algorithm, 44% (552/1268) of patients would have avoided RS testing.

Conclusions

AAMC model is capable of predicting 5-year recurrences in high- and low-risk groups similar to RS. Further, using the P-G algorithm, reserving RS for AAMC intermediate cases, results in larger low- and high-risk groups with similar prognostic accuracy. Thus, the P-G algorithm reliably identifies a significant portion of patients unlikely to benefit from RS assay and with improved ability to categorize risk.

Reversal of the reversed 'Robin Hood syndrome' after superficial temporal-Middle cerebral artery bypass for severe intracranial stenosis

Background: Intracranial arterial stenosis is a common cause of ischemic stroke. Recent attempts with intracranial stenting and superficial temporal-middle cerebral artery (STA-MCA) bypass failed to show benefit. Perhaps, better strategies are needed for selecting suitable patients. Acetazolamide-challenged single photon emission computed tomography (SPECT) can demonstrate reversed Robin Hood syndrome (RRHS) due to intracranial steal phenomenon and identify high-risk patients.Methods: We describe the clinical and SPECT findings of RRHS.Results: In our patient with severe and symptomatic severe stenosis of the right MCA, STA-MCA bypass resulted in complete resolution of RRHS.Conclusion: STA-MCA bypass surgery should be considered a possible option in patients with severe stenosis of intracranial internal carotid artery or MCA in carefully selected patients.

Application of XANES in gamma dosimetry

The thermoluminescence material, CaSO₄:Dy, is widely used for the dosimetry of ionizing radiation due to its high sensitivity, low fading and wide dose range from μGy to few tens of gray. However, its application is limited at high doses due to non-linear and saturation effects. In this paper, X-ray Absorption Near Edge Structure (XANES) studies at the Dy L₃-edge have been carried out on CaSO₄:Dy discs exposed to gamma doses in the range 0-1000 Gy. The results show an increase in white line in XANES spectra with gamma dose. Structural change in CaSO₄:Dy also has been studied using X-Ray Diffraction (XRD) and has found no structural change up to 1000 Gy. The study indicates that XANES can be used as an alternative dosimetry technique and is useful in the evaluation of absorbed dose in the case of accidental exposure to high radiation in a radiation facility or during a radiological accident.

Experimental setup to measure thermal waves generated by X-ray absorption using pyroelectric sensor

Pyroelectric detectors are widely used for infrared radiation detection, whereas these can also be used in the X-ray region. They have multiple advantages when used at synchrotron radiation sources, such as (a) can be used with a white beam (high flux), (b) have a flat spectral response, and (c) can be used both as a detector and as a sample. However, when used in the hard X-ray region, absorption in the detector plays an important role depending upon the thickness of the detector. Hence, the estimation of the responsivity of the detector is important. In this paper, we report an improved experimental setup for the measurement of a pyroelectric signal in the hard X-ray region. The responsivity (V/W) of a pyroelectric detector for absorbed radiation in the hard x-ray region is measured. Measurements of the K-edge x-ray absorption fine structure of 10-μm copper and nickel foils are carried out using a LiTaO₃ pyroelectric detector and compared with the measurements carried out using an ionization chamber as a sensor for the same foils. Absorption spectra near the Ta L_III and L_II edges in LiTaO₃, measured using a LiTaO₃ crystal both as a sample and as a sensor, are also reported in this paper.

Abstract WP72: Recurrent Cerebral Ischemic Events in Symptomatic Carotid Stenosis are Related to Plaque Inflammation

Background and Aims: Severity of symptomatic carotid stenosis often determines the treatment approach. However, severity explains only the regional hypoperfusion as the mechanism of cerebral ischemia. Artery-to-artery embolisation remains an important pathogenic mechanism in patients with high-risk carotid plaques. Inflammation is considered as the initiating event for plaque rupture and cerebral embolism. Using 18F-fluorodeoxyglucose positron-emission tomography (FDG-PET)/computed tomography (CT) and high-resolution magnetic resonance imaging (HR-MRI), we investigated the role of plaque imaging in stroke recurrence in our patients with recently symptomatic carotid stenosis.

Methods: This prospective study included consecutive patients within 30-days of recent stroke and ipsilateral carotid stenosis (≥50%). FDG uptake was quantified as mean standardized uptake values (SUV, g/ml). The ratio of T1 hyperintensity of carotid plaque to the ipsilateral sternocleidomastoid muscle (SCM) was recorded on T1-weighted fat suppressed HR-MRI. Patients were followed-up for stroke recurrence within 90-days.

Results: Of the 115 patients included in the study, 17 (15%) suffered from recurrent cerebral ischemic event in the stenosed carotid territory within 90-days. Compared to patients who remained asymptomatic, patients with recurrent cerebral ischemia showed higher mean T1 carotid-SCM ratio (2.19 versus 1.38; p<0.0001) and higher mean SUV value in the carotid plaque (3.04g/ml versus 1.25g/ml; p<0.0001). Higher T1 carotid-SCM ratio on HR-MRI (OR 3.215, 95%CI 1.304-5.927; p<0.0001) and higher mean SUV on FDG-PET (OR 3.601, 95%CI 2.924-7.628; p=0.005) were independent predictors of recurrent cerebral ischemia.

Conclusions: FDG-PET/CT and HR-MRI of carotid stenosis are useful tools for risk stratification and may aid in better therapeutic decision-making.

Rationale and design of a randomized trial of early intensive blood pressure lowering on cerebral perfusion parameters in thrombolysed acute ischemic stroke patients

BACKGROUND AND RATIONALE

Uncertainty persists over the optimal management of blood pressure (BP) in the early phase of acute ischemic stroke (AIS). This study aims to determine the safety and effects of intensive BP lowering on cerebral blood flow (CBF) and functional in AIS patients treated with intravenous thrombolysis.

METHODS

In a randomized controlled trial, 54 thrombolysed AIS patients with a systolic BP of 160 to 180 mm Hg will be randomized to early intensive BP lowering (systolic target range 140-160 mm Hg) or guideline-based BP management (systolic range 160-180 mm Hg) during first 72-hours using primarily intravenous labetalol. We hypothesize that early intensive BP lowering will not reduce CBF by 20% and/or increase the volume of hypoperfused tissue by >20% on computed tomographic perfusion. Clinical outcome will be assessed using a dichotomized modified Rankin scale (scores 0-1 as excellent outcome vs scores 2-6 as dead or dependent) at 90 days. Other outcome would be symptomatic intracerebral hemorrhage. The trial is registered at ClinicalTrials.gov, NCT03443596.

CONCLUSION

This randomized study will provide important information about the physiological effects of BP reduction on cerebral perfusion after intravenous thrombolysis in AIS.

Free radical scavenging potential of sericin obtained from various ecoraces of tasar cocoons and its cosmeceuticals implication

Tropical tasar silkworm Antheraea mylitta is a wild sericigenous insect which is distributed in different geographical regions and named as different ecoraces. In the present study, we investigated the molecular characterisation and cosmeceutical properties of sericin extracted from different ecoraces of tasar cocoons. The surface morphology and molecular weight of cocoons were determined by scanning electron microscope (SEM) and SDS-PAGE, respectively. Characterisation of sericin was performed by various methods such as FTIR, CHNS, TGA and amino acid analyzer. The anti-tyrosinase, anti-elastase, glutathione-S-transferase inhibition, free radical scavenging potential and inhibition of oxidative damages were measured in tasar ecoraces sericin. SEM images have revealed the removal of sericin from the surface of cocoons. SDS-PAGE of sericin depicted the presence of diverse molecular weight of proteins. Structural determination by FTIR revealed the presence of both α-helical and β-sheet structures. Thermal properties of sericin were studied by TGA which showed a 50% weight loss at temperature 410 °C-430 °C. Additionally, ecoraces sericin contains 17 amino acids in which serine, aspartic acid and glycine are predominantly present (55.68-59.61%). Further, anti-tyrosinase, anti-elastase, inhibition of glutathione-S-transferase activity, free radical scavenging potential and inhibition of lipid peroxidation were also observed in ecoraces sericin. Our findings suggest that the present study appear to be helpful in exploiting sericin as potential biomaterial in cosmeceutical and allied field.

Tasar silk fiber waste sericin: New source for anti-elastase, anti-tyrosinase and anti-oxidant compounds

The present study investigates the properties of sericin extracted from tasar silk fiber waste (TSFW). The surface morphology of TSFW was observed by scanning electron microscope (SEM). SEM images revealed the removal of residual sericin over the surface of TSFW. The molecular weight distribution of sericin was examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results suggested that TSFW sericin represented a family of proteins with wide-ranging molecular weight distribution (11-245 kDa). Structural determination by FTIR revealed the presence of both α-helical and β-sheet structures. The colour was studied by colorimeter indicating less brightness, more red and yellow colour intensities. The carbon: nitrogen ratio (C:N) was studied by CHNS element analyzer and the ratio is 5.15-7.85. Thermal properties of TSFW sericin have been studied by thermogravimetric analysis (TGA) method. TGA curve showed higher thermal stability and variable degradation profiles. Furthermore, TSFW sericin contains 17 amino acids where serine, aspartic acid and glycine are the more significant compounds (54.34-60.49%). In addition, sericin was found to inhibit tyrosinase, elastase and glutathione-S-transferase activity, and had apparent radical scavenging impacts on 2.2‑diphenyl‑1‑picryl‑hydrazil (DPPH), hydrogen peroxide and inhibition of lipid peroxidation. Result suggested that TSFW sericins might be a valuable ingredient for cosmoceutical products.

Abstract 147: Plaque Inflammation is Associated With Early Cerebral Ischemic Events in Symptomatic Carotid Stenosis

Background and aims: Currently, the severity of the symptomatic carotid stenosis determines the treatment approach. However, it explains only the regional hypoperfusion as the mechanism of cerebral ischemia. Artery-to-artery embolisation remains an important pathogenic mechanism in patients with high-risk carotid plaques. Recently, inflammation has been proposed as the initiating event for plaque rupture and cerebral embolism. Using 18F-fluorodeoxyglucose positron-emission tomography (FDG-PET)/computed tomography (CT) and high resolution magnetic resonance imaging (HR-MRI), we investigated the role of plaque imaging and stroke recurrence in our cohort of patients with recently symptomatic carotid stenosis.

Methods: This ongoing prospective study included consecutive patients within 30-days of recent stroke and ipsilateral carotid stenosis (≥50%). FDG uptake was quantified as mean standardized uptake values (SUV, g/ml). The ratio of T1 hyperintensity of carotid plaque to the ipsilateral sternocleidomastoid muscle (SCM) was recorded on T1-weighted fat suppressed HR-MRI. Patients were followed prospectively for stroke recurrence within 90-days.

Results: Of the 70 patients included in the study, 11 (16%) suffered from recurrent cerebral ischemic event in the same vascular territory within 90-days. Compared to patients without subsequent cerebral ischemic events, patients with recurrent cerebral ischemia showed higher mean T1 carotid-SCM ratio (2.24 versus 1.46; p<0.0001) and higher mean SUV value in the carotid plaque (3.26g/ml versus 1.28g/ml; p<0.0001). Higher T1 carotid-SCM ratio on HR-MRI (OR 3.374, 95%CI 1.561-6.253; p<0.0001), higher mean SUV on FDG-PET (OR 3.646, 95%CI 3.172-11.524; p=0.005) were independent predictors of recurrent cerebral ischemia.

Conclusions: FDG-PET/CT and HR-MRI of carotid stenosis helps in identification of patients at higher risk of subsequent cerebral ischemic events and may aid in better therapeutic decision-making.

Long-term survival outcomes of triple-receptor negative breast cancer survivors who are disease free at 5 years and relationship with low hormone receptor positivity

Background:

We counsel our triple-negative breast cancer (TNBC) patients that the risk of recurrence is highest in the first 5 years after diagnosis. However, there are limited data with extended follow-up on the frequency, characteristics, and predictors of late events.

Methods:

We queried the MD Anderson Breast Cancer Management System database to identify patients with stage I–III TNBC who were disease free at 5 years from diagnosis. The Kaplan–Meier method was used to estimate yearly recurrence-free interval (RFI), recurrence-free survival (RFS), and distant relapse-free survival (DRFS), as defined by the STEEP criteria. Cox proportional hazards model was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs).

Results:

We identified 873 patients who were disease free at least 5 years from diagnosis with median follow-up of 8.3 years. The 10-year RFI was 97%, RFS 91%, and DRFS 92% the 15-year RFI was 95%, RFS 83%, and DRFS 84%. On a subset of patients with oestrogen receptor and progesterone receptor percentage recorded, low hormone receptor positivity conferred higher risk of late events on multivariable analysis for RFS only (RFI: HR=1.98, 95% CI=0.70–5.62, P-value=0.200; RFS: HR=1.94, 95% CI=1.05–3.56, P-value=0.034; DRFS: HR=1.72, 95% CI=0.92–3.24, P-value=0.091).

Conclusions:

The TNBC survivors who have been disease free for 5 years have a low probability of experiencing recurrence over the subsequent 10 years. Patients with low hormone receptor-positive cancers may have a higher risk of late events as measured by RFS but not by RFI or DRFS.

Giant Rashba effect at the topological surface of PrGe revealing antiferromagnetic spintronics

Rashba spin-orbit splitting in the magnetic materials opens up a new perspective in the field of spintronics. Here, we report a giant Rashba spin-orbit splitting on the PrGe [010] surface in the paramagnetic phase with Rashba coefficient α R  = 5 eVÅ. We find that α R can be tuned in this system as a function of temperature at different magnetic phases. Rashba type spin polarized surface states originates due to the strong hybridization between Pr 4f states with the conduction electrons. Significant changes observed in the spin polarized surface states across the magnetic transitions are due to the competition between Dzyaloshinsky-Moriya interaction and exchange interaction present in this system. Presence of Dzyaloshinsky-Moriya interaction on the topological surface give rise to Saddle point singularity which leads to electron-like and hole-like Rashba spin split bands in the [Formula: see text] and [Formula: see text] directions, respectively. Supporting evidences of Dzyaloshinsky-Moriya interaction have been obtained as anisotropic magnetoresistance with respect to field direction and first-order type hysteresis in the X-ray diffraction measurements. A giant negative magnetoresistance of 43% in the antiferromagnetic phase and tunable Rashba parameter with temperature makes this material a suitable candidate for application in the antiferromagnetic spintronic devices.

Grading, staging and Nottingham prognostic index scoring of breast carcinoma

Background: Breast carcinoma is the most frequent malignant tumor in women accounting for approximately 15% of female cancer deaths. It is the second most common malignancy among women in Nepal. Our objectives were to study the extent and spread of different histological types breast carcinoma in the eastern region of Nepal, to grade and stage the tumors, score the prognosis.Materials and Methods: A cross-sectional descriptive study of mastectomy specimens with axillary lymph node sampling was done for a period of two years. Diagnosis was done using WHO classification. Modified Bloom Richardson score and TNM system was used to grade and stage the tumors. Nottingham Prognostic index was applied to score the prognosis.Results: Out of 31 total cases, the most common histologic type was Invasive Carcinoma of No Special Type (67.74%). The largest tumor size was of 12cm which had poor NPI score. Most tumors were of grade II and T2. Out of 30 cases with lymph nodes, 13 were negative for metastasis pN0, 10 were pN1 and 7 were pN2. Extranodal spread was observed in 6 out of 17 cases with lymph node metastasis and was associated with higher grades and poor prognosis.Conclusion: Higher grade tumors, lymph node metastasis and extranodal extension are associated with higher Nottingham Prognostic Index score.