bluuebunny/crossref_metadata_2025_split huggingface dataset:
A first-principle density functional study of metal doped ZnO buckyball structure for electronic applications
Authors: Sharma S , Shrivastav A K , Oudhia A , Verma M L 
Published: April 2021

Abstract
The nanostructured ZnO Buckyball (ZnOBB) and Al-doped ZnO Buckyball (ZnOBB: Al) has been optimized and their electronic properties were studied using the first-principle density functional theory (DFT) approach. The study includes the structural and electronic analysis of the system, done by observing the variation in the bond length, cell volume, Density of States (DOS) and Partial Density of States (PDOS). The DOS analysis provides information about Fermi level and bandgap while its further study with PDOS furnished an understanding of the orbitals which are contributing to the overall transition of electrons in the material. The optimized structure of ZnOBB: Al consists of dopant Al placed in the position of one of the Zn atoms in the cage of ZnOBB. Undoped ZnOBB showed a bandgap value ~1.5 eV, while ZnOBB: Al showed an increased bandgap value ~3.25 eV, which is attributed to the reduction in the size of ZnOBB after doping. This work proposes a doping mechanism, which may further explain the modifications of the bandgap. ZnOBB structure is itself a very contemporary topic of research and such kind of alteration in the bandgap with doping increases its applications in optoelectronic devices.
Heat conduction mechanism in AlxGa1-xN ultraviolet light emitting diode
Authors: Sahare Priyanka , Sahoo Bijay Kumar 
Published: April 2021

Abstract
AlxGa1-xN ultra violet light emitting diode (UV LED) has wavelength ranges from 200 to 400nm. UV light has wide range of applications from food processing, health sector, environment and security to space exploration. The energy of one photon of UV light ranges from 3.1 to 6.5 eV which is enough to raise temperature of the active region of the diode above room temperature. The issue is termed as self-heating which shrinks band gap of AlxGa1-xN semiconductor and decreases the emission efficiency of LED. Efficiency droop directly depends on thermal transport in active region of the AlxGa1-xN UV LED. Thus, thermal properties of AlxGa1-xN UV LED should be studied to explore strategies to minimize the issue. In this work we discussed heat conduction mechanism in AlxGa1-xN UV LED. The heat flow in active region is studied by solving heat flux equation in the active region for different material parameter and thermal conductivity. Our study finds that high thermal conductivity of AlxGa1-xN can minimize the self-heating issue and can improve the efficiency of AlxGa1-xN UV LED.
Study of electrical conduction behaviour of Y6-xBa4(SiO4)6O2 oxyapatite doped with ytterbium ions
Authors: Gupta Ritu , Agrawal Sadhana 
Published: April 2021

Abstract
This paper reports the electrical conduction behaviour of Yttrium Barium Silicate Oxyapatite Y6-xBa4Ybx(SiO4)6O2, synthesized by solution combustion method where x varies from 0.01 mol% to 0.05 mol%.. The scanning electron microscopy was done for morphological analysis which shows the spheroidal shaped grains with average grain size of 35μm. The dielectric behaviour of the material was studied in the frequency range of 100Hz – 100KHz and temperature varying from 50°C - 400°C. The frequency dependent dielectric constant and dielectric loss has been plotted for different temperatures. Decrease in dielectric constant and dielectric loss with increase in frequency has been observed for YBaSiO:Yb compounds.
Electrical conduction mechanism of barium doped strontium hydroxyapatite synthesized by co – precipitation method
Authors: Rout Ananya , Agrawal Sadhana 
Published: April 2021

Abstract
The crystalline samples of Barium (Ba) doped Sr10-xBax(PO4)6(OH)2 with x = 0, 0.5 and 1 mol% were prepared by co – precipitation method. The microstructural (SEM) image shows the distribution of densely packed grains over the surface of prepared sample. The nature of cole – cole plots confirm that the conduction mechanism is governed only by the grains with no contribution of grain boundaries for all prepared samples. The resistance of grains decreases with increase in temperature and molar (mol%) concentration, which shows a negative temperature coefficient resistance (NTCR) behaviour for all prepared samples. The a.c. conductivity increases with increase in frequency which shows non – debye nature of the prepared samples.
Growth and photoemission studies of titanium carbide coating by laser carburizing
Authors: Soni Sheetal , Phase D M , Gupta Ratnesh 
Published: April 2021

Abstract
Carburizing of metals is well known technique to modify the tribological properties like hardness and corrosion resistance of metal surfaces. Besides this the electronic structures of nitrides and carbides of titanium metal have great importance from both fundamental and technological point of view. Resonance photoemission electron spectroscopy is a well-known technique to reveal the electronic structure of these alloys. In the present work titanium carbide (TiC) coating has been synthesized by laser carburizing on commercial available pure titanium sheet in a controlled methane atmosphere. X-ray diffraction studies reveal the formation of TiC phase after laser treatment. The hardness of TiC was performed by nano-indentation and its electronic structure has been characterized by x-ray and valence band photoelectron spectroscopy. The measured hardness is six times higher than the pure Ti substrate. Resonance photoemission spectrum of TiC gives maxima at 46 eV, which is a characteristic feature of Ti 3d states in the valence band of TiC coating.
Thermal and electrical properties of InxAl1-xN alloy
Authors: Mehra Jay Kumar , Sahoo Bijay Kumar 
Published: April 2021

Abstract
InxAl1-xN is a promising semiconducting material due to its wide range of potential applications in optoelectronics, bio sensing and in thermoelectric power generation. It has a tunable band gap (6 to 0.7eV), high electron saturation velocity, mobility (290 cm2/Vs) and non-toxic nature. Due to this, the material’s electrical and thermal properties require further study in detail to explore more potential applications. In this work, we have investigated theoretically the thermal and electrical properties of InxAl1-xN alloy to predict thermoelectric (TE) figure of merit and performance to identify the most promising composition and carrier densities for optimum power generation at room temperature and above.
High speed laser induced periodic structure generation using femtosecond laser on surface of titanium
Authors: Mundamajhi A , Parashar S K S , Das S K 
Published: April 2021

Abstract
In this work femtosecond laser wavelength of 800nm, 1KHZ repetition rate and pulse length 100fs irradiation surface texturing has been used. The laser surface texturing is distinguished itself than other conventional processing due to its simplicity controllability and reproducible in creating various structures and wide range of applications. A labview compact zaber xy stage is used for this purpose and investgated the high scanning speed (20mm/s,10mm/s) surface structures on Titanium plate. The velocity of sample position used as function to generate modified surface structures. The surface textured studied by effect of variation of scanning velocity and this texturing process has been done in air medium by above selected parameters. FESEM sample characterization study of surface morphology has been done to details study of textured sample surface.
Influence of Thiourea Metal Complex on Potassium Dihydrogen Phosphate for Optoelectronic Applications
Authors: Rasal Y B 
Published: April 2021

Abstract
Influence of 0.1 mole % Bis Thiourea Zinc Sulphate (BTZS) exhibits concrete reinforcing in optical and dielectric properties of Potassium Dihydrogen Phosphate (KDP). The pure and BTZS influenced KDP crystals have been grown by slow evaporation solution technique at room temperature. The structural and vibrational studies of the grown crystals have been studied by single crystal XRD and FT-IR technique respectively. The optical traits of the doped crystal have been analyzed by UV-vis spectral analysis within the wavelength range of 200-800 nm. The Kurtz-Perry powder test has been employed to determine the bisthiourea zinc sulphate on the second harmonic generation (SHG) efficiency of KDP crystal and it found to be 1.1 times higher than KDP. The dielectric and thermal behaviour has been analyzed for doped KDP crystal.
A new drilling fluid system for plugging argillaceous shale reservoirs
Authors: You Fuchang , Shu Man , Han Yinfu 
Published: April 2021

Abstract
Argillaceous shale reservoir development is mainly based on extended reach horizontal wells, and has complex geological characteristics. In the process of long horizontal drilling, wellbore instability is easy to occur. In this paper, the mechanism of argillaceous shale instability is explored by testing the mineral composition of argillaceous shale. The method of plugging argillaceous shale with nano-sio2 is proposed, and a new nano plugging drilling fluid formulation system is constructed. The system mainly includes specially designed fluid loss additive SFL and EY, flow pattern regulator VBS, lubricant RH, bentonite, nano silica and inorganic salt. Through a series of experimental tests, the rheological property, thermal stability, anti pollution and plugging ability of the system were evaluated. Finally, with the help of SEM, the micro analysis of core profile before and after plugging with nano drilling fluid is carried out, and the plugging mode of nano drilling fluid is further elaborated. The comprehensive results show that nano-sio2 has good compatibility with water-based drilling fluid, and has good effect on inhibiting argillaceous shale expansion and plugging argillaceous shale fractures. It can play the role of stabilizing shale, effectively meet the needs of target block, and provide reference for the follow-up study of plugging argillaceous shale reservoir.
Phases of learning dynamics in artificial neural networks in the absence or presence of mislabeled data
Authors: Feng Yu , Tu Yuhai 
Published: April 2021

Abstract
Despite the tremendous success of deep neural networks in machine learning, the underlying reason for their superior learning capability remains unclear. Here, we present a framework based on statistical physics to study the dynamics of stochastic gradient descent (SGD), which drives learning in neural networks. Using the minibatch gradient ensemble, we construct order parameters to characterize the dynamics of weight updates in SGD. In the case without mislabeled data, we find that the SGD learning dynamics transitions from a fast learning phase to a slow exploration phase, which is associated with large changes in the order parameters that characterize the alignment of SGD gradients and their mean amplitude. In a more complex case, with randomly mislabeled samples, the SGD learning dynamics falls into four distinct phases. First, the system finds solutions for the correctly labeled samples in phase I; it then wanders around these solutions in phase II until it finds a direction that enables it to learn the mislabeled samples during phase III, after which, it finds solutions that satisfy all training samples during phase IV. Correspondingly, the test error decreases during phase I and remains low during phase II; however, it increases during phase III and reaches a high plateau during phase IV. The transitions between different phases can be understood by examining changes in the order parameters that characterize the alignment of the mean gradients for the two datasets (correctly and incorrectly labeled samples) and their (relative) strengths during learning. We find that individual sample losses for the two datasets are separated the most during phase II, leading to a data cleansing process that eliminates mislabeled samples and improves generalization. Overall, we believe that an approach based on statistical physics and stochastic dynamic systems theory provides a promising framework for describing and understanding learning dynamics in neural networks, which may also lead to more efficient learning algorithms.
MDA-GCNFTG: identifying miRNA-disease associations based on graph convolutional networks via graph sampling through the feature and topology graph
Authors: Chu Yanyi , Wang Xuhong , Dai Qiuying , Wang Yanjing , Wang Qiankun , Peng Shaoliang , Wei Xiaoyong , Qiu Jingfei , Salahub Dennis Russell , Xiong Yi , Wei Dong-Qing 
Published: April 2021

AbstractAccurate identification of the miRNA-disease associations (MDAs) helps to understand the etiology and mechanisms of various diseases. However, the experimental methods are costly and time-consuming. Thus, it is urgent to develop computational methods towards the prediction of MDAs. Based on the graph theory, the MDA prediction is regarded as a node classification task in the present study. To solve this task, we propose a novel method MDA-GCNFTG, which predicts MDAs based on Graph Convolutional Networks (GCNs) via graph sampling through the Feature and Topology Graph to improve the training efficiency and accuracy. This method models both the potential connections of feature space and the structural relationships of MDA data. The nodes of the graphs are represented by the disease semantic similarity, miRNA functional similarity and Gaussian interaction profile kernel similarity. Moreover, we considered six tasks simultaneously on the MDA prediction problem at the first time, which ensure that under both balanced and unbalanced sample distribution, MDA-GCNFTG can predict not only new MDAs but also new diseases without known related miRNAs and new miRNAs without known related diseases. The results of 5-fold cross-validation show that the MDA-GCNFTG method has achieved satisfactory performance on all six tasks and is significantly superior to the classic machine learning methods and the state-of-the-art MDA prediction methods. Moreover, the effectiveness of GCNs via the graph sampling strategy and the feature and topology graph in MDA-GCNFTG has also been demonstrated. More importantly, case studies for two diseases and three miRNAs are conducted and achieved satisfactory performance.
P4 A cost utility analysis of robotic versus open mitral valve repair in mitral valve regurgitation
Authors: Rad Arian Arjomandi , Jayaraajan Keerthana , Remtulla Ridhaa , Majeed Ghulam Mustafa , Ammar Omer , Ahmad Aznavar , Vardanyan Robert , Viviano Alessandro 
Published: April 2021

Abstract

Objectives
For the first time this study carried out a cost-utility analysis comparing open surgical repair versus robotic minimally invasive surgical repair for Mitral Regurgitation. The respective benefits and costs of each treatment option gained from data in published literature have been analysed and subsequent suggestions for the allocation of resources and treatment recommendation will be offered.

Methods
The analysis was performed by including intraoperative and post-operative costs of the interventions and costs of the most prevalent complications associated with each operation. Thus, the Quality Adjusted Life Years (QALYs) calculated will guide the decision of resource allocation by assessing whether the added cost of robotic surgery is justified given the NICE (National institute of Clinical Excellence) threshold of £30,000/QALY. The choice of perspective taken is through the lens of the British National Healthcare System.

Results
The Incremental cost-effectiveness ratio (ICER) calculated was £4781.44/QALY. This ICER shows that if robotic surgery was to become gold standard, the NHS would be paying £4781.44/QALY gained per patient. Considering robotic surgery is associated with fewer complications for patients but also has a cost per QALY below the NICE threshold of £30,000/QALY, it seems that this is a fitting alternative to open heart mitral valve repair. After a sensitivity analysis accounting for the initial robotic capital investment the ICER resulted to £22,379.94/QALY, still below NICE’s threshold.

Conclusion
Our results have shown that robotic assisted minimally invasive repair of the mitral valve is a cost-effective option and can be implemented in the British national healthcare setting.
P8 A single centre evaluation of risk prediction models and imaging modalities in acute appendicitis
Authors: Ashcroft James , Singh Aminder A , Rooney Siobhan , Bennett John , Davies Richard Justin 
Published: April 2021

Abstract

Objective
Patients with suspected appendicitis remain a diagnostic challenge. This study aims to validate risk prediction models and to investigate diagnostic accuracy of ultrasonography (US) and computed tomography (CT) in adults undergoing an appendicectomy.

Materials and Methods
A retrospective case review of patients aged 16-45 undergoing an appendicectomy between January 2019 to January 2020 at a tertiary referral centre was performed. Primary outcomes were the accuracy of a high-risk appendicitis risk score and US and CT imaging modalities when compared to histological reports following appendicectomy.

Results
A total of 206 patients (107/205, 51.9% women) were included. Removal of histologically normal appendix was equally likely in men and women (13.1 versus 11.2%, relative risk 1.17, 95% c.i. 0.56 to 2.44; P =0.67). A high-risk appendicitis score correctly identified 84.0% (79/94) of cases in men and 85.9% (67/78) of cases in women. US was reported as equivocal in 85.7% (18/21) of low-risk women and 59.0% (23/39) of high-risk women. CT in low-risk women resulted in 25.0% (2/8) equivocal results whilst correctly diagnosing (5/6) or excluding (1/2) appendicitis in 75.0% of the total cohort (6/8). In high-risk women CT resulted in 3.8% (1/26) equivocal results whilst correctly detecting (22/23) or excluding (1/3) appendicitis in 88.5% of total high-risk patients (23/26).

Conclusions
This study suggests that risk prediction models may be useful in both women and men to identify appendicitis. US imaging gave high rates of equivocal results and should not be relied upon for the diagnosis of appendicitis but may be useful to exclude other differential diagnoses. CT imaging is a highly accurate diagnostic tool and could be considered in those at low-risk where clinical suspicion remains to reduce negative appendicectomy rates.
P11 A systematic review of the reporting of robotic cholecystectomy
Authors: Higginbotham G , Hollowood F , Lok P , Turner B , Gull E , Kirkham E N ,   on behalf of the RoboSurg collaboration
Published: April 2021

Abstract

Introduction
Robotic cholecystectomy (RC) is reported to be an innovative alternative to laparoscopic cholecystectomy for the surgical management of gallbladder disease. Perceived technical benefits of RC include enhanced ergonomic capabilities and visualisation. Whilst RC is becoming increasingly widespread, there is a paucity of high-quality data supporting its use, and conflicting evidence of outcomes in current literature. With accumulating reports citing complications associated with novel invasive procedures, experts have suggested that robust clinical evaluation is required. It is vital that techniques such as RC are evaluated consistently, in order for surgeons to fully educate patients about the treatment and obtain informed consent. This study aims to summarise and appraise the reporting of studies of RC.

Methods
Systematic searches identified all published studies reporting RC. Data collection was based on the IDEAL (Idea, Development, Exploration, Assessment, Long-term follow-up) framework. This will be used to identify key areas of reporting including; general study characteristics, patient selection, regulatory and governance arrangements, operator and centre expertise, technique description, and outcome reporting. Because the study will not aim to draw conclusions about the effectiveness of robotic surgery, meta-analyses will not be not performed.

Results
Systematic searches identified 1425 abstracts; 90 full-text papers were included. Results will be summarised in a narrative synthesis and further data will be analysed prior to presentation.

Conclusion
This in-depth analysis of the published literature on RC will provide evidence to understand how this innovative procedure has been introduced and evaluated in relation to the IDEAL recommendations.
P13 Abdominal Surgery during the COVID-19 Pandemic: A Multicentre Audit
Authors: Hadjittofi Christopher , Uddin Aaliya , Seraj Sanjid , Ali Zeba , Antonas Philipp , Fisher Rebecca , Parekh Kishan , Lovett Bryony 
Published: April 2021

Abstract

Introduction
The threshold for surgery has increased during the COVID-19 pandemic. A widely cited Chinese study (n = 34) reported postoperative COVID-19 pneumonia and mortality rates of 100% and 21% respectively [1]. This audit assessed outcomes after abdominal surgery across three hospitals within Mid & South Essex NHS Foundation Trust.

Methods
Patients undergoing abdominal surgery at Basildon University Hospital, Mid Essex Hospital and Southend University Hospital between 1st March and 27th April 2020 were included. Obstetric, gynaecological, vascular, inguinal/femoral hernia, and skin operations were excluded. Electronic data collection was supplemented by telephone follow-up.

Results
306 patients were included. The median age was 57 years. 148 (48.4%) were female. 156 (51.0%) and 150 (49.0%) patients underwent elective and emergency surgery respectively. The preoperative and postoperative SARS-CoV-2 rates (based on RT-PCR or imaging) were 0.3% (n = 1) and 4.6% (n = 14) respectively. 84.6% (n = 259) did not have RT-PCR tests. All-cause 30-day mortality was 3.6% (n = 11). Amongst patients with SARS-CoV-2, mortality was 50% (7/14), occurring only after emergency surgery. Elective (vs. emergency) surgery was associated with lower postoperative SARS-CoV-2 (0.6% vs. 8.7%; p &lt; 0.001) and mortality (0.6% vs. 6.7%; p = 0.005). At follow-up, 79.1% (242/306) of patients responded, most (85.1%; 206/242) without major clinical issue.

Conclusion
Local SARS-CoV-2 and mortality rates are lower than previously reported [1]. Perioperative COVID-19 carries a high mortality risk. We recommend perioperative SARS-CoV-2 testing for all patients and cohorting by infection status.

References
1. Lei et al., Clinical characteristics and outcomes of patients undergoing surgeries during the incubation period of COVID-19 infection, EClinicalMedicine(2020), https://doi.org/10.1016/j.eclinm.2020.100331
P36 Consent for Orthopaedic Trauma Surgery during the COVID-19 Pandemic
Authors: Walker J , Davies A , Heaton T , Sabharwal S , Fertleman M , Dani M , Reilly P 
Published: April 2021

Abstract
Surgical services have been hugely disrupted by COVID-19 and have had to evolve rapidly in response. The best practice for consent mandates that risks associated with surgical treatment during a pandemic be discussed. This study aimed to assess whether patients undergoing orthopaedic operations were being consented for the risk of contacting COVID-19 and ITU care.
All orthopaedic consent forms from four-week periods in March, June and July were reviewed. Measures such as staff education were implemented after the second cycle.
Of consent forms for 37 operations performed in March, only 1 mentioned the risk of contracting COVID-19 and zero mentioned ITU. During June, 89 consent forms were reviewed, 32 mentioned COVID-19 and 10 discussed ITU admission. Following educational measures, the third cycle showed a significant improvement as of 100 consent form records available for review, 73 included risk of COVID-19 whilst 26 mentioned ITU.
The results show that earlier in the pandemic, surgeons at our centre were not counselling patients regarding COVID-19. This improved slightly between the first and second cycles, likely reflecting increased awareness of the nosocomial transmission of COVID-19. Educational measures contributed to a significant improvement in the third cycle. Planned interventions include use of electronic consent forms which incorporate COVID-19 infection and associated risks.