bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation and Contrast Analysis of tem Images of Cracks
Authors: Goyal D. , H. King A. 
Published: June 2020

TEM images of cracks have been found to give rise to a moiré fringe type of contrast. It is apparent that the moire fringe contrast is observed because of the presence of a fault in a perfect crystal, and is characteristic of the fault geometry and the diffracting conditions in the TEM. Various studies have reported that the moire fringe contrast observed due to the presence of a crack in an otherwise perfect crystal is distinctive of the mode of crack. This paper describes a technique to study the geometry and mode of the cracks by comparing the images they produce in the TEM because of the effect that their displacement fields have on the diffraction of electrons by the crystal (containing a crack) with the corresponding theoretical images. In order to formulate a means of matching experimental images with theoretical ones, displacement fields of dislocations present (if any) in the vicinity of the crack are not considered, only the effect of the displacement field of the crack is considered.The theoretical images are obtained using a computer program based on the two beam approximation of the dynamical theory of diffraction contrast for an imperfect crystal. The procedures for the determination of the various parameters involved in these computations have been well documented. There are three basic modes of crack. Preliminary studies were carried out considering the simplest form of crack geometries, i. e., mode I, II, III and the mixed modes, with orthogonal crack geometries. It was found that the contrast obtained from each mode is very distinct. The effect of variation of operating conditions such as diffracting vector (), the deviation parameter (ω), the electron beam direction () and the displacement vector were studied. It has been found that any small change in the above parameters can result in a drastic change in the contrast. The most important parameter for the matching of the theoretical and the experimental images was found to be the determination of the geometry of the crack under consideration. In order to be able to simulate the crack image shown in Figure 1, the crack geometry was modified from a orthogonal geometry to one with a crack tip inclined to the original crack front. The variation in the crack tip direction resulted in the variation of the displacement vector also. Figure 1 is a cross-sectional micrograph of a silicon wafer with a chromium film on top, showing a crack in the silicon.
Theoretical Study of Weak-Beam Images of Stacking Faults Decorated with Impurities
Authors: Anstis G. R. 
Published: June 2020

Weak—beam dark—field images of stacking faults in silicon vary in an interesting way as the angle of inclination of a fault to the beam changes. It is observed that the contrast of images formed with beam +g varies with angle of inclination at a rate different from that associated with beam −g. For the case of an extrinsic fault it was found that this variation can be calculated using the kinematical theory of scattering and by modelling the fault as two discontinuous changes to the crystal potential across neighbouring (111) plane. Thus the weak—beam imaging technique is sensitive to some of the details of atomic arrangements near the fault. To explain the contrast variation of intrinsic faults it is necessary to model the smooth transition of the crystal potential from one side of the fault to the other. While such a model gives a qualitatative description of experimental studies it is not able to account for the large differences in contrast between +g images and −g images that have been observed experimentally. In this paper it is postulated that the presence of impurity atoms near the plane of the fault accounts for some of the features of experimental observations.The theory is based on the kinematical theory of scattering and the rigid ion model of the crystal potential. A crystal containing a stacking fault consists of a unit which repeats indefinitely in directions parallel to the plane of the fault. Along a line perpendicular to the fault the repeat unit is displaced by a vector R across the plane of the fault. The impurity atoms are assumed to be distributed periodically on planes parallel to the fault.
Off-pump ascending aorta or aortic arch to descending aorta bypass with a pericardial roll for the treatment of critically ill infants with interrupted aortic arch
Authors: Oztas Didem M. , Meric Mert , Beyaz Metin O. , Coban Senay , Sari Gizem , Yildiz Yahya , Ulukan Mustafa O. , Unal Orcun , Rodoplu Orhan , Sungur Zerrin , Yozgat Yilmaz , Saritas Turkay , Erdem Abdullah , Ugurlucan Murat , Tireli Emin , Turkoglu Halil 
Published: June 2020

AbstractAim:Standard surgical treatment of the interrupted aortic arch with the use of cardiopulmonary bypass is risky especially in critically ill babies. In this manuscript, we present the results of off-pump pericardial roll bypass for the treatment of aortic interruption.Material and methods:The technique was applied in nine critically ill infants between July 2011 and December 2019. Data were reviewed retrospectively. There were four girls and five boys. The types of the interruption were type B in six cases and type A in three babies. Additional cardiovascular anomalies were ventricular septal defect in all, atrial septal defect or patent foramen ovale in all, single-ventricle pathologies in two and bicuspid aortic valve in three cases. All the patients were in critical situations such as intubated, having symptoms of infection, congestive heart failure or ischaemia and malperfusion leading visceral organ dysfunction.Results:All patients underwent off-pump ascending aorta or aortic arch to descending aorta bypass with a pericardial roll. Post-operative early mortality occurred in one patient with severe mitral regurgitation due to cardio-septic shock. One patient who had single-ventricle pathology underwent bidirectional Glenn and was lost on the post-operative 26th day due to sepsis 2 years after operation. Two patients presented with dilatation of the pericardial tube 18 and 24 months after the operations and one underwent reconstruction of the neo-arch. The remaining patients are asymptomatic, active and within normal limits of body and mental growth.Conclusion:Treatment of interrupted aortic arch with a bypass with an autologous pericardial roll treated with gluteraldehyde without cardiopulmonary bypass seems a safe and reliable technique especially for the treatment of critically ill infants.
Flux Ropes Are Born in Pairs: An Outcome of Interlinked, Reconnecting Flux Tubes
Authors: Russell C. T. , Qi Yi 
Published: June 2020

AbstractFlux transfer events are transient magnetized plasma structures that are self‐balancing, rope‐like phenomena that can appear at the Earth's magnetopause when the interplanetary magnetic field is southward. The formation of this type of flux rope has been unclear. Using measurements of particles and magnetic fields on the MMS spacecraft, we find that rope‐like structures containing magnetospheric energetic electrons have exactly the same occurrence rate as those without magnetospheric electrons, independent of solar wind properties and location of observation. This equality is consistent with a pair of flux bundles being generated at the same time but displaced from each other as an outcome of their collision and resultant entanglement and reconnection. This entanglement reconnection produces one flux rope with two ends connected to the magnetosphere and the other connected on both ends to the shocked solar wind. Away from the subsolar entanglement zone, reconnection transports magnetic flux from the “closed” magnetosphere to the “open” tail lobes, as predicted by Dungey (1961, https://doi.org/10.1103/PhysRevLett.6.47).
Reversing abnormal hole localization in high-Al-content AlGaN quantum well to enhance deep ultraviolet emission by regulating the orbital state coupling
Authors: Chen Li , Lin Wei , Wang Huiqiong , Li Jinchai , Kang Junyong 
Published: June 2020

AbstractAlGaN has attracted considerable interest for ultraviolet (UV) applications. With the development of UV optoelectronic devices, abnormal carrier confinement behaviour has been observed for c-plane-oriented AlGaN quantum wells (QWs) with high Al content. Because of the dispersive crystal field split-off hole band (CH band) composed of pz orbitals, the abnormal confinement becomes the limiting factor for efficient UV light emission. This observation differs from the widely accepted concept that confinement of carriers at the lowest quantum level is more pronounced than that at higher quantum levels, which has been an established conclusion for conventional continuous potential wells. In particular, orientational pz orbitals are sensitive to the confinement direction in line with the conducting direction, which affects the orbital intercoupling. In this work, models of Al0.75Ga0.25N/AlN QWs constructed with variable lattice orientations were used to investigate the orbital intercoupling among atoms between the well and barrier regions. Orbital engineering of QWs was implemented by changing the orbital state confinement, with the well plane inclined from 0° to 90° at a step of 30° (referred to the c plane). The barrier potential and transition rate at the band edge were enhanced through this orbital engineering. The concept of orbital engineering was also demonstrated through the construction of inclined QW planes on semi- and nonpolar planes implemented in microrods with pyramid-shaped tops. The higher emission intensity from the QWs on the nonpolar plane compared with those on the polar plane was confirmed via localized cathodoluminescence (CL) maps.
Mini-LED, Micro-LED and OLED displays: present status and future perspectives
Authors: Huang Yuge , Hsiang En-Lin , Deng Ming-Yang , Wu Shin-Tson 
Published: June 2020

AbstractPresently, liquid crystal displays (LCDs) and organic light-emitting diode (OLED) displays are two dominant flat panel display technologies. Recently, inorganic mini-LEDs (mLEDs) and micro-LEDs (μLEDs) have emerged by significantly enhancing the dynamic range of LCDs or as sunlight readable emissive displays. “mLED, OLED, or μLED: who wins?” is a heated debatable question. In this review, we conduct a comprehensive analysis on the material properties, device structures, and performance of mLED/μLED/OLED emissive displays and mLED backlit LCDs. We evaluate the power consumption and ambient contrast ratio of each display in depth and systematically compare the motion picture response time, dynamic range, and adaptability to flexible/transparent displays. The pros and cons of mLED, OLED, and μLED displays are analysed, and their future perspectives are discussed.
Daily estimates of clinical severity of symptoms in bipolar disorder from smartphone-based self-assessments
Authors: Busk Jonas , Faurholt-Jepsen Maria , Frost Mads , Bardram Jakob E. , Kessing Lars Vedel , Winther Ole 
Published: June 2020

AbstractCurrently, the golden standard for assessing the severity of depressive and manic symptoms in patients with bipolar disorder (BD) is clinical evaluations using validated rating scales such as the Hamilton Depression Rating Scale 17-items (HDRS) and the Young Mania Rating Scale (YMRS). Frequent automatic estimation of symptom severity could potentially help support monitoring of illness activity and allow for early treatment intervention between outpatient visits. The present study aimed (1) to assess the feasibility of producing daily estimates of clinical rating scores based on smartphone-based self-assessments of symptoms collected from a group of patients with BD; (2) to demonstrate how these estimates can be utilized to compute individual daily risk of relapse scores. Based on a total of 280 clinical ratings collected from 84 patients with BD along with daily smartphone-based self-assessments, we applied a hierarchical Bayesian modelling approach capable of providing individual estimates while learning characteristics of the patient population. The proposed method was compared to common baseline methods. The model concerning depression severity achieved a mean predicted R2 of 0.57 (SD = 0.10) and RMSE of 3.85 (SD = 0.47) on the HDRS, while the model concerning mania severity achieved a mean predicted R2 of 0.16 (SD = 0.25) and RMSE of 3.68 (SD = 0.54) on the YMRS. In both cases, smartphone-based self-reported mood was the most important predictor variable. The present study shows that daily smartphone-based self-assessments can be utilized to automatically estimate clinical ratings of severity of depression and mania in patients with BD and assist in identifying individuals with high risk of relapse.
Specificity of end resection pathways for double-strand break regions containing ribonucleotides and base lesions
Authors: Daley James M. , Tomimatsu Nozomi , Hooks Grace , Wang Weibin , Miller Adam S. , Xue Xiaoyu , Nguyen Kevin A. , Kaur Hardeep , Williamson Elizabeth , Mukherjee Bipasha , Hromas Robert , Burma Sandeep , Sung Patrick 
Published: June 2020

AbstractDNA double-strand break repair by homologous recombination begins with nucleolytic resection of the 5’ DNA strand at the break ends. Long-range resection is catalyzed by EXO1 and BLM-DNA2, which likely have to navigate through ribonucleotides and damaged bases. Here, we show that a short stretch of ribonucleotides at the 5’ terminus stimulates resection by EXO1. Ribonucleotides within a 5’ flap are resistant to cleavage by DNA2, and extended RNA:DNA hybrids inhibit both strand separation by BLM and resection by EXO1. Moreover, 8-oxo-guanine impedes EXO1 but enhances resection by BLM-DNA2, and an apurinic/apyrimidinic site stimulates resection by BLM-DNA2 and DNA strand unwinding by BLM. Accordingly, depletion of OGG1 or APE1 leads to greater dependence of DNA resection on DNA2. Importantly, RNase H2A deficiency impairs resection overall, which we attribute to the accumulation of long RNA:DNA hybrids at DNA ends. Our results help explain why eukaryotic cells possess multiple resection nucleases.
Graph theory approach to determine configurations of multidentate and high coverage adsorbates for heterogeneous catalysis
Authors: Deshpande Siddharth , Maxson Tristan , Greeley Jeffrey 
Published: June 2020

AbstractHeterogeneous catalysts constitute a crucial component of many industrial processes, and to gain an understanding of the atomic-scale features of such catalysts, ab initio density functional theory is widely employed. Recently, growing computational power has permitted the extension of such studies to complex reaction networks involving either high adsorbate coverages or multidentate adsorbates, which bind to the surface through multiple atoms. Describing all possible adsorbate configurations for such systems, however, is often not possible based on chemical intuition alone. To systematically treat such complexities, we present a generalized Python-based graph theory approach to convert atomic scale models into undirected graph representations. These representations, when combined with workflows such as evolutionary algorithms, can systematically generate high coverage adsorbate models and classify unique minimum energy multidentate adsorbate configurations for surfaces of low symmetry, including multi-elemental alloy surfaces, steps, and kinks. Two case studies are presented which demonstrate these capabilities; first, an analysis of a coverage-dependent phase diagram of absorbate NO on the Pt3Sn(111) terrace surface, and second, an investigation of adsorption energies, together with identifying unique minimum energy configurations, for the reaction intermediate propyne (CHCCH3*) adsorbed on a PdIn(021) step surface. The evolutionary algorithm approach reproduces high coverage configurations of NO on Pt3Sn(111) using only 15% of the number of simulations required for a brute force approach. Furthermore, the screening of potentially hundreds of multidentate adsorbates is shown to be possible without human intervention. The strategy presented is quite general and can be applied to a spectrum of complex atomic systems.
Personalized early detection and prevention of breast cancer: ENVISION consensus statement
Authors: Pashayan Nora , Antoniou Antonis C. , Ivanus Urska , Esserman Laura J. , Easton Douglas F. , French David , Sroczynski Gaby , Hall Per , Cuzick Jack , Evans D. Gareth , Simard Jacques , Garcia-Closas Montserrat , Schmutzler Rita , Wegwarth Odette , Pharoah Paul , Moorthie Sowmiya , De Montgolfier Sandrine , Baron Camille , Herceg Zdenko , Turnbull Clare , Balleyguier Corinne , Rossi Paolo Giorgi , Wesseling Jelle , Ritchie David , Tischkowitz Marc , Broeders Mireille , Reisel Dan , Metspalu Andres , Callender Thomas , de Koning Harry , Devilee Peter , Delaloge Suzette , Schmidt Marjanka K. , Widschwendter Martin 
Published: June 2020

AbstractThe European Collaborative on Personalized Early Detection and Prevention of Breast Cancer (ENVISION) brings together several international research consortia working on different aspects of the personalized early detection and prevention of breast cancer. In a consensus conference held in 2019, the members of this network identified research areas requiring development to enable evidence-based personalized interventions that might improve the benefits and reduce the harms of existing breast cancer screening and prevention programmes. The priority areas identified were: 1) breast cancer subtype-specific risk assessment tools applicable to women of all ancestries; 2) intermediate surrogate markers of response to preventive measures; 3) novel non-surgical preventive measures to reduce the incidence of breast cancer of poor prognosis; and 4) hybrid effectiveness–implementation research combined with modelling studies to evaluate the long-term population outcomes of risk-based early detection strategies. The implementation of such programmes would require health-care systems to be open to learning and adapting, the engagement of a diverse range of stakeholders and tailoring to societal norms and values, while also addressing the ethical and legal issues. In this Consensus Statement, we discuss the current state of breast cancer risk prediction, risk-stratified prevention and early detection strategies, and their implementation. Throughout, we highlight priorities for advancing each of these areas.
Molecular approaches underlying the oogenic cycle of the scleractinian coral, Acropora tenuis
Authors: Tan Ee Suan , Izumi Ryotaro , Takeuchi Yuki , Isomura Naoko , Takemura Akihiro 
Published: June 2020

AbstractThis study aimed to elucidate the physiological processes of oogenesis in Acropora tenuis. Genes/proteins related to oogenesis were investigated: Vasa, a germ cell marker, vitellogenin (VG), a major yolk protein precursor, and its receptor (LDLR). Coral branches were collected monthly from coral reefs around Sesoko Island (Okinawa, Japan) for histological observation by in situ hybridisation (ISH) of the Vasa (AtVasa) and Low Density Lipoprotein Receptor (AtLDLR) genes and immunohistochemistry (IHC) of AtVasa and AtVG. AtVasa immunoreactivity was detected in germline cells and ooplasm, whereas AtVG immunoreactivity was detected in ooplasm and putative ovarian tissues. AtVasa was localised in germline cells located in the retractor muscles of the mesentery, whereas AtLDLR was localised in the putative ovarian and mesentery tissues. AtLDLR was detected in coral tissues during the vitellogenic phase, whereas AtVG immunoreactivity was found in primary oocytes. Germline cells expressing AtVasa are present throughout the year. In conclusion, Vasa has physiological and molecular roles throughout the oogenic cycle, as it determines gonadal germline cells and ensures normal oocyte development, whereas the roles of VG and LDLR are limited to the vitellogenic stages because they act in coordination with lipoprotein transport, vitellogenin synthesis, and yolk incorporation into oocytes.
Analysis of Breast Cancer Patients with T1-2 Tumors and 1-3 Positive Lymph Nodes Treated with or without Postmastectomy Radiation Therapy
Authors: Gilmore Richard C. , Sebai Mohamad E. , Psoter Kevin J. , Prasath Vishnu , Siotos Charalampos , Broderick Kristen P. , Jacobs Lisa K. , Harvey Susan C. , Habibi Mehran 
Published: June 2020

AbstractThe use of postmastectomy radiation therapy (PMRT) has been recommended for patients with 4 or more positive lymph nodes, however, its role in patients with 1-3 positive lymph nodes remains unclear. The purpose of this study is to evaluate oncological outcomes for breast cancer patients with T1-2 tumors and 1-3 positive lymph nodes after undergoing PMRT. We performed a single-institution retrospective investigation that evaluated the association between PMRT and outcomes in breast cancer patients with T1-2 tumors and 1-3 positive lymph nodes, who underwent mastectomy from 2004 to 2015. Multivariable Cox proportional hazards regression was used to evaluate the association of PMRT with disease-free survival and overall survival. A total of 379 patients met inclusion criteria, of which 204 (54%) received PMRT while 175 (46%) did not receive PMRT following mastectomy and were followed over a median of 5.2 years (25th–75th percentile: 2.8–8.4 years). Recurrence was similar in patients receiving PMRT compared to those that did not: locoregional (0 vs 3, P = 0.061), distant (9 vs 3, P = 0.135) and any recurrence (11 vs 7, P = 0.525). After adjustment for potential confounding variables, PMRT was not associated with a statistically significant difference in disease-free survival (HR: 0.93; 95% CI: 0.48, 1.79) or overall survival (HR: 0.91; 95% CI: 0.45, 1.85). PMRT was not associated with improved oncological outcomes in patients with T1-2 breast cancer and 1-3 positive lymph nodes at our institution.
Comparison of host immune responses to LPS in human using an immune profiling panel, in vivo endotoxemia versus ex vivo stimulation
Authors: Tawfik Dina M. , Lankelma Jacqueline M. , Vachot Laurence , Cerrato Elisabeth , Pachot Alexandre , Wiersinga W. Joost , Textoris Julien 
Published: June 2020

AbstractPatients that suffer from sepsis exhibit an early hyper-inflammatory immune response which can lead to organ failure and death. In our study, we assessed the immune modulation in the humanin vivoendotoxemia model and compared it toex vivoLPS stimulation using 38 transcriptomic markers. Blood was collected before and after 4 hours of LPS challenge and tested with the Immune Profiling Panel (IPP) using the FilmArray system. The use of IPP showed that markers from the innate immunity dominated the response to LPSin vivo, mainly markers related to monocytes and neutrophils. Comparing the two models,in vivoandex vivo, revealed that most of the markers were modulated in a similar pattern (68%). Some cytokine markers such asTNF,IFN-γandIL-1βwere under-expressedex vivocompared toin vivo. T-cell markers were either unchanged or up-modulatedex vivo, compared to a down-modulationin vivo. Interestingly, markers related to neutrophils were expressed in opposite directions, which might be due to the presence of cell recruitment and feedback loopsin vivo. The IPP tool was able to capture the early immune response in both the humanin vivoendotoxemia model, a translational model mimicking the immune response observed in septic patients.