bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Serum Mammaglobin as an Alternative Biomarker in the Diagnosis of Breast Tumors
Authors: Fatima Maira , Sai Baba Kompella S. S. , Sreedevi Neelam N. R. , Kumar Japa P. , Raju Gottumukkala S. , Uppin Shantveer G. , Bhaskar Madrol V. , Khan Siraj Ahmed , Iyyapu Krishna M. , Noorjahan Mohammed
Published: August 2022

Introduction Breast cancer is the most common cancer in women in India and accounts for 14% of all cancers in women. Rise in mortality is due to lack of awareness and proper screening. Mammography and presently available serum biomarkers have low sensitivity and specificity. In our quest to identify a better biomarker, we studied mammaglobin (MAM) in patients with breast cancer and benign breast tumors.

Aim To evaluate serum mammaglobin in breast cancer patients and compare it with benign breast tumor patients and healthy controls. To compare it with existing biomarkers serum carcinoembryonic antigen (CEA) and cancer antigen 15–3 (CA 15–3). Materials and methods: This is a cross-sectional, case–control study of 77 subjects, of which 27 were breast cancer patients, 20 benign breast tumor patients, and 30 healthy controls. Serum CEA and CA15–3 were estimated by electrochemiluminescence immunoassay (ECLIA) and mammaglobin (MAM) by enzyme-linked immunosorbent assay (ELISA).

Results Mammaglobin and CEA levels were elevated in breast cancer patients, followed by benign breast tumors when compared with controls (P < 0.000001). Mammaglobin showed 81.5% sensitivity, 100% specificity, 100% positive predictive value (PPV), and 88.9% negative predictive value (NPV). CEA showed 88.9% sensitivity, 82.5% specificity, 77.4% PPV, and 91.7% NPV. The area under the curve was the highest for MAM (0.892), followed by CEA (0.889) and CA 15–3 (0.555). CA15–3 showed poor diagnostic efficacy. Combined receiver operating characteristic (ROC) curve of the biomarkers MAM and CEA had an AUC of 0.913.

Conclusion Mammaglobin proved to be an efficacious biomarker in diagnosing breast cancer.
Clinical Outcomes of Autologous Hematopoietic Stem Cell Transplant in Multiple Myeloma Patients: A 5-year Experience from a Single Centre in North India
Authors: Sood Nitin , Tiwari Aseem Kumar , Pabbi Swati , Dikshit Roshan , Singh Prerna , Ramaswami Amrita , Gautam Dheeraj , Singh Manish Kumar
Published: August 2022

Introduction Multiple myeloma (MM) forms a significant proportion of hematological malignancies. Autologous transplantation continues to be an effective consolidation strategy in resource-restricted settings such as India.

Objectives The main objective of the study was to analyze the clinical outcomes of autologous hematopoietic stem cell transplant (HSCT) in MM patients in a single tertiary care center in north India over a period of 5 years.

Materials and Methods This retrospective observational study was conducted in a tertiary care center in north India. Data of all MM patients who underwent HSCT between January 2014, and December 2018, were analyzed. The outcome of HSCT was investigated in terms of transplant-related mortality (TRM), progression-free survival (PFS), overall survival (OS), and relapse. PFS and OS were calculated by Kaplan–Meier method and differences between the groups were tested for statistical significance using the two-tailed log-rank test. Life-table method was used for the estimation of survival rate at 1, 3, 5, and 6 years.

Results Patient characteristics and survival post-transplant was similar to other published Indian studies. In total, 378 patients were diagnosed with MM in our hospital between 2014 and 2018. One hundred ninety-three patients were found to be eligible for autologous HSCT, out of which 52 ended up having a transplant giving us a high percentage (26.9%) of patients receiving a transplant in our setting. Transplant-related mortality (TRM) was nil in the present study. The mean PFS and OS were 62.8 and 70.1 months, respectively. The mean PFS and OS rates at 5 years were 75.3% and 84.2%, respectively. The average cost estimate of HSCT in our setting was 7.2 lakh Indian national rupees.

Conclusion Autologous HSCT is a safe procedure with nil 100-day mortality in present series. Moreover, considering the cost of novel agents, autologous transplant remains a cost-effective way for prolonging remission and time-to-next treatment in India.
Hypertrophic Pachymeningitis Presenting as “Eyebrows” Sign on 18F FDG PET/CT
Authors: Vankadari Kousik , Alwala Surendar , Kumar Komal , Ram Sai
Published: August 2022

Hypertrophic pachymeningitis refers to linear or nodular thickening of the dura mater covering the brain and spinal cord following various inflammatory/infective processes. Usually, magnetic resonance imaging brain shows uniform thickening with enhancement of involved meninges. Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) findings of pachymeningitis are rarely reported in literature. We describe the PET/CT findings of a patient with hypertrophic pachymeningitis involving the bilateral supraorbital regions depicting as “eyebrows” on brain maximum intensity projection image.
3D-QSAR and Docking Studies on Pyrimidine Derivatives of Second-Generation ALK Inhibitors
Authors: Jiang Gang-Long , Song Lian-Hua , Qiu Yong-Fu , Liu Yu
Published: August 2022

Anaplastic lymphoma kinase (ALK) is a promising target for the treatment of non-small cell lung cancer. Under crizotinib treatment, drug resistance and progressive disease appeared after the point mutations arising in the kinase domain of ALK. Second-generation ALK inhibitors can solve the deficiencies of the first generation, especially the drug resistance in cancer chemotherapy. Ceritinib (LDK378), a pyrimidine derivative, for example, can inhibit the activity of ALK with an IC50 value of 40.7 nmol/L, and can experience disease progression after initial treatment with crizotinib. Unfortunately, clear structure–activity relationships have not been identified to date, impeding the rational design of future compounds possessing ALK inhibition activity. To explore interesting insights into the structures of pyrimidine derivatives that influence the activities of the second-generation ALK inhibitors, three-dimensional quantitative structure–activity relationship (3D-QSAR) and molecular docking were performed on a total of 45 derivatives of pyrimidine. Comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) techniques were used to generate 3D-QSAR models. CoMFA and CoMSIA were performed using the Sybyl X 2.0 package. Molecular docking analysis was performed using the Surflex-Dock module in SYBYL-X 2.0 package. We found in the CoMFA model that the non-cross-validated r2
value was 0.998, the cross-validated q
2 value was 0.663, and the F statistic value was 2,401.970, while the r2
value was 0.988; q
2 value was 0.730, and F value was 542.933 in CoMSIA models, suggesting the good predictability of the CoMFA and CoMSIA models. 3D contour maps and docking results suggested that different groups on the core parts of the compounds could enhance the biological activities. Based on these results, the established 3D-QSAR models and the binding structures of ALK inhibitors obtained favor the prediction of the activity of new inhibitors and will be helpful in the reasonable design of ALK inhibitors in the future.
An Audit of Diagnostic Disparity between Intraoperative Frozen Section Diagnosis and Final Histopathological Diagnosis of Central Nervous System Lesions at a Tertiary Care Center
Authors: Yadav Meghna , Sharma Pragya , Singh Vikram , Tewari Rohit , Mishra Prabha Shankar , Roy Kaushik
Published: August 2022

Introduction Evaluation of intraoperative squash smear and frozen section (FS) in central nervous system (CNS) neoplasms is consistently practiced for rapid assessment and has several advantages to its credence. It is an invaluable tool to ensure adequacy of tissue obtained to establish the diagnosis. Moreover, it aids in guiding the surgeon for critical decisions regarding the extent of resection. Although molecular markers have been integrated with morphology in the revised 2016 World Health Organization classification of brain tumors, precise morphological assessment still remains the foundation for the diagnosis and rapid intraoperative assessment of morphological details is equally critical and rewarding.

Objective This study aims to audit the diagnostic disparity between intraoperative diagnoses based on a combination of squash cytology and FS in cases of CNS lesions with gold standard, final diagnosis based on examination of formalin fixed paraffin embedded hematoxylin, and eosin-stained tissue sections.

Materials and Methods All intraoperative squash cytology and FS reported for CNS lesions from January 2017 to December 2020 were reviewed. The cases were categorized into three groups—group 1: when diagnosis of intraoperative diagnosis based on a combination of squash cytology and FS was same as the final histopathological diagnosis (concordant), group 2: partially concordant, and group 3: discordant cases.

Statistical Analysis Descriptive statistics was used to classify the data and diagnostic accuracy was calculated.

Results Complete concordance was present in 69.96% (191/273) cases, 20.1% (55/273) cases showed partial concordance, and 9.89% (27/273) cases were discordant with histopathological diagnosis. Out of the 27 discordant cases, misclassification of tumor type was the most common category (11 cases, 40%), followed by grading mismatch (7 cases, 25.9%), and misdiagnosis of tumor versus nontumor conditions (9 cases, 33.3%).

Conclusion Our study shows that combination of intraoperative squash cytology and FS shows a high percentage of accuracy in arriving at intraoperative diagnosis in cases of intracranial lesions. Regular audits of discordant cases should be conducted by surgeons and pathologists as part of a quality assurance measure to sensitize themselves with the potential pitfalls, minimizing misinterpretation and helping in providing a more conclusive opinion to the operating surgeons.
Role of 99mTc-Mebrofenin Hepatobiliary Scintigraphy in the Diagnosis of Post Cholecystectomy Syndrome
Authors: Sowmya S. Durga , Gupta Amit , Narayan Manishi L. , Chauhan Udit , Jain Jaydeep , Singla Tanuj , Chennatt Jaine John
Published: August 2022

Background Huge variation in the prevalence of post cholecystectomy syndrome (PCS) is because PCS can include a wide variety of disorders that can be both related and unrelated to cholecystectomy. Hepatobiliary scintigraphy (HBS) is a noninvasive nuclear medicine scan that can evaluate a delay in the transit of bile from the hepatic hilum to the duodenum using a radiotracer 99mTc-Mebrofenin that can be associated with a functional ampullary obstruction. The aim of this study was to assess the role of 99mTc-Mebrofenin HBS in the detection of the cause of PCS among the patients undergoing cholecystectomy.

Methods Twenty-one patients who presented with PCS from September 2018 to February 2020 were included in the study. These patients were characterized based on history, examination, liver function test, and abdominal ultrasound. Sphincter of Oddi dysfunction (SOD) was diagnosed using the Rome 3 criteria and the Milwaukee classification. Magnetic resonance cholangiopancreatography (MRCP) and upper gastrointestinal endoscopy and biopsy were done when indicated, to establish the diagnosis. These patients were further subjected to 99mTc-Mebrofenin HBS, and the findings were analyzed.

Results The most common symptom in PCS was biliary pain occurring in 85.7% of the patients. The average time of presentation since surgery was 1.9 years. The most common cause of PCS was SOD, occurring in 52.3% of the patients, followed by benign biliary stricture occurring in 23.8% of the patients. The mean bile duct (common bile duct) visualization time in patients with PCS was 25.2 minutes, the mean duodenal visualization time was 38.2 minutes, and the mean jejunal visualization time was 60.5 minutes. The mean bile duct to duodenum transit time was 12.7 minutes, while the mean bile duct to jejunum transit time was 30.1 minutes. HBS showed consistent findings with the final diagnosis made by other diagnostic modalities (clinical criteria/MRCP/intraoperative findings) in 80.9% of the patients.

Conclusion 99mTc-Mebrofenin HBS has a significant role in the evaluation of PCS.
A Comparative Study of Regional Cerebral Blood Flow Asymmetry Index in Stroke Patients with or without Poststroke Depression Using 99mTc-ECD Single-Photon Emission Computed Tomography
Authors: Maurya Pradeep Kumar , Qavi Abdul , Deswal Satyawati , Singh Ajai Kumar , Kulshreshtha Dinkar , Thacker Anup Kumar
Published: August 2022

Introduction Stroke is a major cause of death and disability around the globe. The development of depression following a stroke further increases the disability and impairs functional recovery. In recent decades, despite the advancement in structural and nuclear medicine imaging, the pathophysiologic basis of poststroke depression (PSD) is not well understood. Etiopathogenesis of PSD is multifactorial and afflictions of the frontal lobe, hippocampus, limbic region, and basal ganglia projections are implicated.

Aim The aim of this study was to assess the regional cerebral blood flow (rCBF) using 99mTc-ethyl cysteinate dimer single-photon emission computed tomography (SPECT) in patients with (PSD + ) or without PSD (PSD–).

Materials and Methods To evaluate the hemispheric asymmetry, the percentage of asymmetry index (AI) was calculated for frontal, temporal, parietal, occipital, putamen, caudate, and thalamic regions of brain and compared between PSD+ and PSD–. The correlation between AIs over the different brain regions was also established in patients of PSD+ and PSD–. Our study cohort included 122 patients between 6 weeks and 1 year of stroke. Depression was present in 52 (42.6%) patients, assessed by hospital anxiety and depression scale (HADS) and general health questionnaire-28 items (GHQ-28) scale. The 28 patients with PSD+ and 18 PSD– gave consent for SPECT study.

Results Our results are based on 46 patients who underwent SPECT study. In patients with PSD+ and PSD–, the HADS and GHQ-28 scores were 8.93 ± 2.77 vs. 3.94 ± 2.15 (p = 0.001) and 40.96 ± 9.48 vs. 17.72 ± 5.38 (p = 0.001), respectively. A significant difference in rCBF AI was found in the temporal lobe (p = 0.03) between patients of PSD+ and PSD–. On logistic regression analysis, the odds ratio of rCBF AI for temporal lobe was 0.89 (95% confidence interval [CI]: 0.80–0.99; p = 0.04) and caudate nucleus was 0.85 (95% CI: 0.73–0.98; p = 0.03), which were statistically significant. PSD correlated with AI in temporal region (r = –0.03; p = 0.03) but did not show significant correlation with other regions of brain between PSD+ and PSD–.

Conclusion The presence of temporal lobe rCBF AI on SPECT is significantly associated with PSD. This may reflect the dysfunction of the limbic system and contribute to the occurrence of PSD.
Multimodality Imaging in the Diagnosis and Assessment of Cardiac Amyloidosis
Authors: Velaga Jyothirmayi , Liew Charlene , Choo Poh Angeline Choo , Lee Phong Teck , Lath Narayan , Low Shoen Choon , Bharadwaj Pushan
Published: August 2022

Amyloidosis is a rare disorder where abnormal protein aggregates are deposited in tissues forming amyloid fibrils, leading to progressive organ failure. Although any organ can be affected, cardiac involvement is the main cause of morbidity and mortality associated with amyloidosis as diagnosis is often delayed due to the indolent nature of the disease in some forms. An early diagnosis of disease and knowledge of the type/subtype of cardiac amyloidosis (CA) are essential for appropriate management and better outcome. Echocardiography is often the first line of investigation for patients suspected of CA and offers superior hemodynamic assessment. Although cardiovascular magnetic resonance (CMR) imaging is not diagnostic of CA, it provides vital clues to diagnosis and has a role in disease quantification and prognostication. Radiolabeled bone seeking tracers are the mainstay of diagnosis of CA and when combined with screening of monoclonal light chains, bone scintigraphy offers high sensitivity in diagnosing transthyretin type of CA. This review aims to describe the noninvasive imaging assessment and approach to diagnosis of patients with suspected CA. Imaging features of echocardiography, nuclear scintigraphy, and CMR are described with a brief mention on computed tomography.
In Vitro Efficacy of Biocompatible Zinc Ion Chelating Molecules as Metallo-β-Lactamase Inhibitor among NDM Producing Escherichia coli
Authors: Rudresh Shoorashetty Manohar , Ravi Giriyapura Siddappa , Raksha Yoganand
Published: August 2022

Objective This article assesses the effectiveness of captopril, tetracycline, and ciprofloxacin as metallo-β-lactamase (MBL) inhibitors against New Delhi metallo-β-lactamase (NDM)-producing Escherichia coli.

Materials and Methods Twenty-four well-characterized carbapenem-resistant E. coli isolates which produced NDM (n = 21) and Oxa-48-like enzymes (n = 3) were used to assess the inhibitors. The positive control organism was designed by cloning the NDM gene into pET-24a plasmid and transforming it into expression vector E. coli BL21. All the proposed inhibitors were assessed for their interaction with MBLs using checkerboard minimum inhibitory concentration (MIC) assay with imipenem and meropenem. The fractional inhibitory concentration (FIC) index was calculated to assess the activity of molecules.

Results The E. coli BL21 (DE3) pET-24a-bla
NDM showed carbapenem resistance upon isopropyl β-D-1-thiogalactopyranoside induction and had MIC of 32 µg/mL for both imipenem and meropenem. For the test isolates, ∑FIC values of imipenem and meropenem with ethylenediaminetetraacetic acid (EDTA) ranged from 0.039 to 0.266 and 0.023 to 0.156, respectively. At a 256 µg/mL concentration, captopril had ∑FIC index value for imipenem and meropenem as 0.133 to 0.375 and 0.133 to 0.188, respectively. The tetracycline and ciprofloxacin in combination with meropenem/imipenem showed indifferent results.

Conclusion Among the three molecules tested, captopril had MBL inhibitory activity, but the concentration required for inhibition was beyond the therapeutic safety levels. Ciprofloxacin and tetracycline had weak or no MBL inhibitory activity. Checkerboard MIC of EDTA with carbapenem antibiotic and control organism with NDM enzyme production helped us create a reference system for comparing and assessing the results of potential MBL inhibitors in future.
Challenges Encountered and Pattern-Based Analysis of Bone Marrow Biopsy in Lymphomas: An Institutional Experience
Authors: Kalra Supreet Kaur , Sancheti Sankalp , Somal Puneet Kaur , Sali Akash Pramod , Sharma Aishwarya , Goel Alok , Jain Shivani , Dora Tapas Kumar , Gulia Ashish , Divetia Jigeeshu V.
Published: August 2022

Objective The evaluation of bone marrow (BM) status is an integral part of the initial workup of patients diagnosed with lymphoma as it plays an important role in staging and predicting prognosis in these patients. This article determines the incidence and pattern of BM involvement in lymphoma cases and distinguishes benign from malignant lymphoid aggregates in BM biopsies.

Materials and Methods The study group included 121 cases of Hodgkin and non-Hodgkin lymphomas for which BM biopsies were performed, fixed in acetic acid-zinc formalin solution, decalcified using 10% formic acid, and subjected to hematoxylin and eosin and immunohistochemistry.

Results The overall incidence of BM biopsy involvement in our study was 31.4% (37/118), including 34.7% (35/101) in cases of B cell lymphomas, 25% (2/8) in cases of T cell lymphomas, and no involvement in Hodgkin lymphoma. The predominant histological pattern of BM involvement was diffused (14/37; 37.8%), followed by interstitial (10/37; 27.1%). Five cases revealed benign nonparatrabecular lymphoid aggregates which could be confused with lymphomatous involvement, especially in low grade lymphomas.

Conclusion A careful examination of the BM biopsies along with clinical history, peripheral blood examination, flow cytometry, and immunohistochemistry will help in arriving at the correct diagnosis.
Peptide Receptor Radionuclide Therapy Using 177Lu-DOTATATE in Advanced Neuroendocrine Tumors (NETs) in a Limited-Resource Environment
Authors: Kalantarhormozi Mohammadreza , Hassanzadeh Samaneh , Rekabpour Seyed Javad , Ravanbod Mohammad Reza , Jafari Esmail , Amini AbdulLatif , Dadgar Habibollah , Mahmoudpour Mehdi , Nabipour Iraj , Jokar Narges , Assadi Majid
Published: August 2022

Background This study was conducted to evaluate the clinical efficacy and safety of peptide receptor radionuclide therapy (PRRT) using 177Lu-DOTA0-Tyr3-octreotate (DOTATATE) in patients with neuroendocrine tumors (NETs).

Methods Sixteen patients with pathologically verified NETs including eight females and eight males were enrolled in this study. Before PRRT, the patients underwent 68Ga-DOTATATE positron emission tomography/computed tomography or 99mTc-octreotide scintigraphy for evaluation of somatostatin receptor expression. Response to treatment was assessed according to the Response Evaluation Criteria In Solid Tumors (RECIST) classified as complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD). In addition, for evaluation of toxicity, monthly blood analysis was performed including hematology, renal function (creatinine) test, and liver function test. The Eastern Cooperative Oncology Group (ECOG) status performance was applied to estimate the patients' general condition in a scale of 0 (fully active) to 5 (dead). In addition, overall survival (OS) was calculated as the time interval from the start of PRRT to death from any reason.

Results Sixteen patients including eight females and eight males with a median age of 60.5 years (range: 24–74) were enrolled in this study. The patients underwent PRRT with a median cycle of 3.5 (range: 1–7) and a median dose of 20.35 (range: 7.4–49.95 GBq). At the end of data collection, PR, CR, SD, and PD were seen in 11, 2, 1, and 2 patients according to the RECIST, respectively. Three patients expired during or after the PRRT period. The median ECOG and Karnofsky Performance Scale was 1.5 and 75 before PRRT, which improved significantly to 1 and 80 after PRRT, respectively (p < 0.05). According to the Kaplan–Meier test, the median OS was 23 months (95% confidence interval: 7.90–38.09). According to the National Cancer Institute's Common Terminology Criteria for Adverse Events, three patients showed grade I and three patients showed grade II leucopenia. Furthermore, three and seven patients had grade II and grade I anemia, respectively.

Conclusion Since PRRT using 177Lu-DOTATATE has a favorable response rate and few adverse effects and improves the quality of life in NETs, it can be used as an effective therapeutic option, especially in nonoperative, metastatic, and progressive NETs.
Screening of bimetallic electrocatalysts for water purification with machine learning
Authors: Tran Richard , Wang Duo , Kingsbury Ryan , Palizhati Aini , Persson Kristin Aslaug , Jain Anubhav , Ulissi Zachary W.
Published: August 2022

Electrocatalysis provides a potential solution to NO3− pollution in wastewater by converting it to innocuous N2 gas. However, materials with excellent catalytic activity are typically limited to expensive precious metals, hindering their commercial viability. In response to this challenge, we have conducted the most extensive computational search to date for electrocatalysts that can facilitate NO3− reduction reaction, starting with 59 390 candidate bimetallic alloys from the Materials Project and Automatic-Flow databases. Using a joint machine learning- and computation-based screening strategy, we evaluated our candidates based on corrosion resistance, catalytic activity, N2 selectivity, cost, and the ability to synthesize. We found that only 20 materials will satisfy all criteria in our screening strategy, all of which contain varying amounts of Cu. Our proposed list of candidates is consistent with previous materials investigated in the literature, with the exception of Cu–Co and Cu–Ag based compounds that merit further investigation.
High transconductance and current density in field effect transistors using arrays of bundled semiconducting carbon nanotubes
Authors: Foradori Sean M. , Dwyer Jonathan H. , Suresh Anjali , Gopalan Padma , Arnold Michael S.
Published: August 2022

We examine if the bundling of semiconducting carbon nanotubes (CNTs) can increase the transconductance and on-state current density of field effect transistors (FETs) made from arrays of aligned, polymer-wrapped CNTs. Arrays with packing density ranging from 20 to 50 bundles μm−1 are created via tangential flow interfacial self-assembly, and the transconductance and saturated on-state current density of FETs with either (i) strong ionic gel gates or (ii) weak 15 nm SiO2 back gates are measured vs the degree of bundling. Both transconductance and on-state current significantly increase as median bundle height increases from 2 to 4 nm, but only when the strongly coupled ionic gel gate is used. Such devices tested at −0.6 V drain voltage achieve transconductance as high as 50 μS per bundle and 2 mS μm−1 and on-state current as high as 1.7 mA μm−1. At low drain voltages, the off-current also increases with bundling, but on/off ratios of ∼105 are still possible if the largest (95th percentile) bundles in an array are limited to ∼5 nm in size. Radio frequency devices with strong, wraparound dielectric gates may benefit from increased device performance by using moderately bundled as opposed to individualized CNTs in arrays.
Exchange-stiffness measurement scheme based on domain-wall chirality transition
Authors: Nam Yune-Seok , Kim Dae-Yun , Park Yong-Keun , Yu Ji-Sung , Lee Seong-Hyub , Kim Duck-Ho , Min Byoung-Chul , Choe Sug-Bong
Published: August 2022

Herein, we propose an experimental scheme to determine the strength of the Heisenberg exchange interaction in ultrathin magnetic films. In this scheme, the chirality transition between the Bloch- and Néel-type domain walls is analyzed under an in-plane magnetic field. Subsequently, the exchange stiffness constant is estimated based on the strength of the magnetic field for chirality transitions, as proposed by an analytical theory pertaining to chirality transitions, and confirmed based on micromagnetic prediction. Using the magneto-optical Kerr effect with high sensitivity on surface atomic layers, the present scheme is applicable to ultrathin magnetic films down to a few atomic layers, whose sensitivity is well below the lowest sensitivity limit of conventional measurement schemes. Hence, the present scheme is useful for extending the experimental range to investigate the exchange stiffness of few-atomic-layer-thick magnetic films.
High-temperature non-centrosymmetric magnets for skyrmionics
Authors: Karube Kosuke , Taguchi Yasujiro
Published: August 2022

Such topological spin textures as magnetic skyrmions and antiskyrmions have attracted significant interest in recent years owing to their rich variety of underlying physics and potential applications in next-generation magnetic devices. In the domain of applications, it is essential to stabilize the topological spin textures over a wide range of temperatures, including room temperature, and manipulate them with various external stimuli. Significant developments have been made in room-temperature skyrmions and antiskyrmions arising from the Dzyaloshinskii–Moriya interaction (DMI) in several magnetic materials with broken inversion symmetry. In this Perspective, we review recent progress in non-centrosymmetric magnets with bulk DMI, which host skyrmions and antiskyrmions above room temperature. We first provide an overview of room-temperature Bloch-type skyrmions and the robustness of their metastability, the variety of their forms, and their dynamics in Co–Zn–Mn alloys with a β-Mn-type chiral structure. We then focus on room-temperature antiskyrmions as well as their topological transformations in Heusler alloys with D2d symmetry and Pd-doped (Fe,Ni)3P with S4 symmetry. The robust skyrmions and antiskyrmions, with versatile tunability in these non-centrosymmetric materials at room temperature, represent a step toward the long-sought milestone of “skyrmionics.”
Characterization and modeling of resistive switching phenomena in IGZO devices
Authors: Carvalho G. , Pereira M. E. , Silva C. , Deuermeier J. , Kiazadeh A. , Tavares V.
Published: August 2022

This study explores the resistive switching phenomena present in 4 µm2 amorphous Indium–Gallium–Zinc Oxide (IGZO) memristors. Despite being extensively reported in the literature, not many studies detail the mechanisms that dominate conduction on the different states of IGZO-based devices. In this article, we demonstrate that resistive switching occurs due to the modulation of the Schottky barrier present at the bottom interface of the device. Furthermore, thermionic field emission and field emission regimes are identified as the dominant conduction mechanisms at the high resistive state of the device, while the bulk-limited ohmic conduction is found at the low resistive state. Due to the high complexity associated with creating compact models of resistive switching, a data-driven model is drafted taking systematic steps.
Study of high-pressure hydrogen annealing effects on InGaZnO thin-film transistors
Authors: Lee Kyumin , Jung Laeyong , Hwang Hyunsang
Published: August 2022

High-pressure hydrogen annealing (HPHA) treatment is an effective hydrogen doping method to improve electrical characteristics and stability of InGaZnO (IGZO) thin film transistors (TFTs). The HPHA effects on IGZO TFTs under various pressure conditions were investigated using analytical techniques. Drive current, field effect mobility, subthreshold swing, and bias stress stability of IGZO TFTs were significantly improved as the HPHA pressure was increased up to 20 atm. To analyze the performance enhancement, secondary ion mass spectroscopy, capacitance–voltage analysis, and x-ray photoelectron spectroscopy analysis techniques were performed. As a result, it was confirmed that doped hydrogen is combined with interface trap sites and oxygen vacancy related bulk defect sites, leading to improved subthreshold swing and bias stress stability. Furthermore, bulk trap passivation also contributes to high carrier density, thereby increasing driving current and field effect mobility. With increasing HPHA pressure condition, these effects of trap passivation and increase in the carrier density are more effective due to the heavily injected hydrogen.
Thermal transport properties of monolayer GeS and SnS: A comparative study based on machine learning and SW interatomic potential models
Authors: Li Wentao , Yang Chenxiu
Published: August 2022

Phonon transport properties of two-dimensional materials can play a crucial role in the thermal management of low-dimensional electronic devices and thermoelectric applications. In this study, both the empirical Stillinger–Weber (SW) and machine learning interatomic potentials are employed to investigate the lattice thermal conductivity of monolayer GeS and SnS through solving the phonon Boltzmann transport equation. The accuracy of the two types of interatomic potentials and their performance for the evaluation of thermal conductivity are verified by analyzing phonon harmonic and anharmonic properties. Our results indicate that the thermal conductivity can be predicted more accurately with a machine learning approach, while the SW potential gives rise to an overestimated value for both monolayers. In addition, the in-plane anisotropy of thermal transport properties existing in these monolayers can be confirmed by both potential models. Moreover, the origins of the deviation existing in calculated thermal conductivities, including both the effects of interatomic potential models and monolayer compositions, are elucidated through uncovering the underlying phonon transport mechanisms. This study highlights that in contrast to the machine learning approach, more careful verification is required for the simulation of thermal transport properties when empirical interatomic potential models are employed.
Modeling and optimization of GaN-based betavoltaic batteries: Comparison of p–n and p–i–n junctions
Authors: Chen Ziyi , Zheng Renzhou , Lu Jingbin , Li Xiaoyi , Wang Yu , Zhang Xue , Zhang Yuehui , Cui Qiming , Yuan Xinxu , Zhao Yang , Li Haolin
Published: August 2022

Nuclear battery is a promising long-life power source. Selecting semiconductors with high limit efficiency and appropriate device structures effectively improves their output performance. In this work, a GaN-based (hexagonal) betavoltaic battery with Ni63 source was simulated by Monte Carlo codes and COMSOL Multiphysics, and the energy converters, including p–n junction and p–i–n junction, were compared and optimized. We analyzed the effects of thickness and doping concentration of each region on the battery performances. The p-region and n-region thickness and doping concentration of the p–n junction-based battery are 0.5, 9.5 µm, 1017 cm−3, and Nd = 1016 cm−3, which can achieve 3.77% conversion efficiency, and the short-circuit current density, open-circuit voltage, and maximum output power density are 0.074 µA/cm2, 2.01 V, and 0.125 µW/cm2, respectively. For the p–i–n junction-based battery, when the thickness and the doping concentration of p-region, i-region, and n-region are 0.5, 3, 6.5 µm, 1017, 1014, and 1016 cm−3, respectively, the conversion efficiency, short-circuit current density, open-circuit voltage, and maximum output power density are 5.03%, 0.099 µA/cm2, 2.0 V, and 0.167 µW/cm2, respectively. By comparing the output parameters of the two types of batteries, the results indicate that the p–i–n junction has a wider depletion region and better output performance compared with the p–n junction.
Versatility of uniformly doped graphene quantum Hall arrays in series
Authors: Mhatre S. M. , Tran N. T. M. , Hill H. M. , Yeh C.-C. , Saha D. , Newell D. B. , Hight Walker A. R. , Liang C.-T. , Elmquist R. E. , Rigosi A. F.
Published: August 2022

In this work, the limiting factors for developing metrologically useful arrays from epitaxial graphene on SiC are lifted with a combination of centimeter-scale, high-quality material growth and the implementation of superconducting contacts. Standard devices for metrology have been restricted to having a single quantized value output based on the ν = 2 Landau level. With the demonstrations herein of devices having multiple outputs of quantized values available simultaneously, these versatile devices can be used to disseminate the ohm globally. Such devices are designed to give access to quantized resistance values over the range of three orders of magnitude, starting as low as the standard value of ∼12.9 kΩ and reaching as high as 1.29 MΩ. Several experimental methods are used to assess the quality and versatility of the devices, including standard lock-in techniques and Raman spectroscopy.
Research on the traceability method based on half symmetric superposition
Authors: Bao Jin , Duan Meimei , Li Jun
Published: August 2022

In order to achieve high-accuracy self-calibration and traceability of electromagnetic standard voltage transformers, a measurement method that can be used for voltage ratio standard error voltage coefficients is proposed. Using two auxiliary standard voltage transformers, the error variation of the voltage transformer under different voltages can be obtained through three-step measurement. Compared with the traditional error voltage coefficient measurement method and international comparison, the feasibility of the method and the rationality of the uncertainty evaluation of the measurement results are verified. The self-calibration ratio difference measurement uncertainty of the 110 kV standard voltage transformer is better than 5 × 10−6, and the angular difference measurement uncertainty is better than 5 µrad. The method can be used to trace the source of standard devices up to 1000 kV power frequency voltage ratio, which have characteristics such as high accuracy and good stability.
Effects of meander curvature in thermally stratified turbulent open-channel flow
Authors: Nguyen Duy , Kirkpatrick Michael P. , Williamson N. , Armfield S. W. , Lin W.
Published: August 2022

Thermal stratification can lead to the damping of turbulence, which reduces the mixing of solutes in a fluid body. A series of direct numerical simulation (DNS) solutions sweeping through a range of four different meandering channel curvatures, from a sharp to mild curvature range, are obtained to investigate the effect of curvature on stratification in meandering thermally stratified turbulent open channel flow with an internal heat source that models radiative heating from above. Based on the DNS results, the present paper addresses two issues. First, the influence of changing curvature on the complex bi-cellular pattern of the secondary flow is investigated, including the distribution of the temperature field. Second, the effects of changing curvature on the degree of stratification are analyzed. Stratification can be characterized by the friction Richardson number Riτ and the bulk Richardson number Rib. Stratification can also be viewed in terms of the transfer of energy from mean flow kinetic energy to potential energy via buoyancy fluxes. We study the effect of curvature on stratification by investigating its effect on the friction and bulk Richardson numbers. We also study the transfers between the global potential and kinetic energy reservoirs, including the global available Ea, background Eb, and total potential energy Ep, and the domain-averaged mean kinetic and turbulent kinetic energy. It is found that, in meandering channels, with the increase in curvature, Ep increases and Riτ and Rib decrease, indicating that increasing curvature leads to a decrease in the level of stratification. On the other hand, we also find that a low curvature meandering channel has a higher level of stratification than a straight channel.
Large third-order optical nonlinearities of two-dimensional CsPbBr3 nanoplatelets
Authors: Huang Ruiqin , Kang Enze , Gao Han , Guo Renbo , Hu Qingsong , Han Yibo
Published: August 2022

Metal halide perovskites show considerable optical nonlinearity and could be used for cost-effective nonlinear optical devices if their nonlinear susceptibilities can be improved. Here, we report large optical nonlinearity, including third-order nonlinear absorption, refraction, and two-photon absorption excited luminescence, of CsPbBr3 nanoplatelets with a thickness of two or three atomic layers and a plane size of about 60 nm. Specifically, the nonlinear absorption was mainly induced by two-photon absorption at low incident powers, and the nonlinear absorption cross section reached 2.15 × 107 GM. It is two orders of magnitude larger than that of CsPbBr3 nanocrystals, which makes them an ideal optical limiting material. Furthermore, the nanoplatelets exhibited large self-phase modulation-induced nonlinear refraction, and the figures of merit W and T satisfied W >1 and T <1, which allow for optical switching. The large optical nonlinearity of CsPbBr3 nanoplatelets provides a basis for multifunctional applications in nonlinear optical devices.
The flow patterns and sediment deposition in the forebay of a forward-intake pumping station
Authors: Wang Haidong , Li Chunguang , Lu Suiju , Song Lulu
Published: August 2022

In Northwest China, the concentration of sediment in the Yellow River is high. The flow patterns in the forebay and inlet tank of a pumping station on the river are disordered, and sediment deposition endangers the normal operation and safety of the pumping station. To address this problem, the three-dimensional two-phase water–sediment flow in the forebay of the pumping station is modeled using fluid simulation software, and diagrams of the sediment content and velocity streamline in the flow layers of different sections are obtained. Combined with the multiphase flow theory of mixtures and the realizable k–ε turbulent kinetic energy equation, the location and formation mechanism of each vortex, as well as the area and degree of sediment deposition in the forebay, are analyzed. The actual engineering and numerical simulation results are compared to verify the accuracy of the simulation, and the operating conditions of each pump port under different unit operating conditions are proposed. The results show that the deposition of sediment has different effects on the outlets of the pumps, but its impact on pump Nos. 4, 5, and 6 is small. After desilting, the velocity uniformity and deflection angle of pumps 4, 5, and 6 are improved to a certain extent. This study provides specific guidance for the construction and reconstruction of a pumping station forebay to avoid the impacts of backflow areas and sediment deposition to a certain extent.
New Zealand’s rural hospitals in 2021: findings from an exploratory questionnaire survey
Authors: Blattner Katharina , Clay Lynne , Miller Rory , Nixon Garry , Crengle Sue , Richard Lauralie , Anton Ray , Stokes Tim
Published: August 2022

Introduction There is a gap in our knowledge of the place and contribution of rural hospitals in the New Zealand health system. There is no current description of rural hospital services, no national policies and little published research regarding their value. Aim To explore rural hospital leader perspectives of the role of rural hospitals. Methods An on-line survey of rural hospital leaders conducted to capture perspectives on areas including facility nomenclature; access and equity; funding and the health reforms. Results Fifty-five rural hospital leaders representing 19/24 rural hospitals responded. ‘Rural Hospital’ was the most common term used to describe facilities with 80% of respondents indicating this as their preferred term. Other descriptive terms varied widely from primary through to secondary care. Respondents indicated that the loss of rural hospital in-patient beds would be unacceptable to communities (median 0, IQR 0, 1). Scores on questions about ‘range of services’ (median 7, IQR 6, 8), ‘accessibility’ (median 7, IQR 6, 8) and how rural hospitals were addressing health equity (median 6, IQR 5, 7) were variable. The process for allocating funds to rural hospitals was perceived as lacking transparency (median 3, IQR 2, 5). National strategy and ‘local governance and control’ were both rated as important (median 9, IQR 7, 10 and median 9, IQR, 8, 10) for a rural hospital’s future. Discussion By capturing a collective national rural hospital leadership voice, this study facilitates the understanding of the rural hospital concept. The findings inform subsequent research needed to gain a clearer picture of New Zealand rural hospital provision.
Multiple perspectives on group work in a multilingual context
Authors: Storch Neomy , Zhao Helen , Morton Janne
Published: August 2022

Group assignments are widely used in higher education for a range of educational reasons. Although there is a large body of research on the merits of group work and factors that may contribute to successful group work, less is known about students’ and teachers’ perspectives, particularly when groups are composed of students from diverse linguistic backgrounds. The current qualitative study investigated students’ and teachers’ perspectives on group assignments in a Master of Applied Linguistics program offered by a leading research university in Australia. The program has predominantly English as an additional language (EAL) students. Teachers and students in four graduate subjects that involved group assignments were interviewed for their views and reflections. Analysis of the interview data revealed similarities and differences in perspectives in five main areas – group work benefits and challenges, group formation and assessment, and the need for pre-implementation training. The findings highlight the need for teachers to promote open discussion about the purposes and merits of group work, both pedagogical and social.
Esperanto – Lingua Franca and Language Community
Authors: Fiedler Sabine , Brosch Cyril Robert
Published: August 2022

This book addresses a fascinating topic – a constructed language that has turned from a project into a fully-fledged language used by some of its speakers on a daily basis. Based on extensive fieldwork, this book provides rare and profound insights into the use of Esperanto in a large number of communicative areas. It studies the speakers’ use of code-switching, phraseology and metaphors, techniques they employ to enhance understanding, such as metacommunication and repair strategies, as well as their predilection for humour. The study also contributes to a comparison between the communication in Esperanto and in the language that is now predominantly used as a lingua franca – English – and allows conclusions to be drawn on the question of what a lingua franca is all about.
Vav independently regulates synaptic growth and plasticity through distinct actin-based processes
Authors: Park Hyun Gwan , Kim Yeongjin David , Cho Eunsang , Lu Ting-Yi , Yao Chi-Kuang , Lee Jihye , Lee Seungbok
Published: August 2022

Modulation of presynaptic actin dynamics is fundamental to synaptic growth and functional plasticity; yet the underlying molecular and cellular mechanisms remain largely unknown. At Drosophila NMJs, the presynaptic Rac1-SCAR pathway mediates BMP-induced receptor macropinocytosis to inhibit BMP growth signaling. Here, we show that the Rho-type GEF Vav acts upstream of Rac1 to inhibit synaptic growth through macropinocytosis. We also present evidence that Vav-Rac1-SCAR signaling has additional roles in tetanus-induced synaptic plasticity. Presynaptic inactivation of Vav signaling pathway components, but not regulators of macropinocytosis, impairs post-tetanic potentiation (PTP) and enhances synaptic depression depending on external Ca2+ concentration. Interfering with the Vav-Rac1-SCAR pathway also impairs mobilization of reserve pool (RP) vesicles required for tetanus-induced synaptic plasticity. Finally, treatment with an F-actin–stabilizing drug completely restores RP mobilization and plasticity defects in Vav mutants. We propose that actin-regulatory Vav-Rac1-SCAR signaling independently regulates structural and functional presynaptic plasticity by driving macropinocytosis and RP mobilization, respectively.
Wavefront error based tilt-to-length noise analysis for the LISA transmitted beam
Authors: Weaver Alexander Joseph , Mueller Guido , Fulda Paul J
Published: August 2022

The laser interferometer space antenna (LISA) will open the signal-rich 100 μHz to 1 Hz gravitational wave window. LISA is expected to be limited by acceleration noise in the low frequency range and noise associated with the optical measurement system above a few mHz. Of the latter, apparent length changes due to spacecraft (SC) angular jitter are among the most critical contributors. One of the coupling mechanisms is via wavefront error in the transmitted beam. Utilizing a Zernike polynomial decomposition of such wavefront error, we introduce and explore the validity of extremely fast best fit polynomial expansion based noise recreation tools that provide a clear picture for which transmit beam perturbations couple most strongly with SC jitter into LISA noise.