bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct matrix converter based on improved quasi‐Z source network
Authors: Zou Bowei , Guo Yougui , Wang Zhen , Gui Qingzhong , Shi Mingzhang , Tu Yulin
Published: February 2021

This study proposes a three‐phase direct matrix converter (DMC) topology based on an improved quasi‐Z source (QZS) network. The proposed topology shows the following features: (i) Improve the voltage transmission ratio of traditional DMC. (ii) The voltage and current on the output side can be affected by the input side to the minimum, which minimises the harmonic content of the output current. (iii) Due to the existence of the improved QZS network, the three bidirectional switches of each output phase bridge arm are turned‐on at the same time, which improves the reliability of the system. (iv) The improved QZS network has an input LC filter function, and no additional filter circuit is required on the input side. This study analyses the topological structure of the improved QZS‐DMC and elaborates its boost working principle. On this basis, an improved dual space vector modulation strategy with shoot‐through zero vector is proposed, which can effectively reduce the loss of the switch tube and improve the output waveform quality of the converter. Simulation and experimental results verify the proposed topology and strategy.
Meeting IEC and ER G4/5 harmonic standards in nine‐level cascaded H‐bridge inverters using an improved SHM‐PAM scheme
Authors: Kundu Sourabh , Banerjee Subrata , Ronanki Deepak , Williamson Sheldon S.
Published: February 2021

This study introduces a new switching scheme for nine‐level cascaded H‐bridge (CHB) inverter to comply with the harmonic standards (IEC 61000‐2‐12, IEC 61000‐3‐6, and ER G4/5) using an improved selective harmonic minimisation pulse amplitude modulation (SHM‐PAM) scheme. In this scheme, the optimised switching instances and variable DC‐link voltages are determined by solving some new constraints based cost functions using particle swarm optimisation (PSO) technique. The theoretical analysis and optimisation results of the proposed modulation scheme are validated through MATLAB simulations and experimentally on a laboratory‐scale prototype of CHB inverter. The proposed modulation scheme utilises a minimal number of switching instances in a fundamental period and optimisation variables in the problem formulation in comparison to conventional SHE‐PWM and SHE‐PAM schemes. The key performance of the proposed scheme in terms of harmonic and loss analysis is evaluated over the wide range of the power factors and modulation index. Finally, the suitability of the proposed scheme is tested for the closed‐loop speed control of a 5 hp, 415 V three‐phase induction motor.
Feedforward phase compensation method of LCL grid‐connected inverter based on all‐pass filter in weak grid
Authors: Xue Tongyu , Sun Pengju , Xu Zezhong , Luo Quanming
Published: February 2021

Inverter‐side current feedback control (ICFC) has been extensively adopted in distributed generation systems because of its simple implementation and better consistency with actual operating conditions. At the same time, when there are a large number of background harmonics in the grid, capacitor voltage feedforward (CVF) is usually added to the system for its suppression. This method could make the system keep the first‐order characteristics under the analogue control. However, under digital control, due to the digital control delay, a reverse resonance peak will be generated in the loop gain, which makes the system unstable in the weak grid. In order to solve the aforementioned problems, this study proposes a feedforward phase compensation method of LCL grid‐connected inverter based on the all‐pass filter (AF). By introducing AF into the CVF channel, the phase lag in the range of reverse resonance peak frequency is compensated, so as to enhance the robustness of the system in the weak grid. At the same time, this study gives the detailed design process of the proposed method. Experimental results on a 3‐kW prototype are provided, and the effectiveness of the proposed control method is verified..
A dual‐attention V‐network for pulmonary lobe segmentation in CT scans
Authors: Zheng Shaohua , Nie Weiyu , Pan Lin , Zheng Bin , Shen Zhiqiang , Huang Liqin , Pei Chenhao , She Yuhang , Chen Liuqing
Published: February 2021

The reliable and automatic segmentation of pulmonary lobes in computed tomography scans is an important pre‐condition for the diagnosis, assessment, and treatment of lung diseases. However, due to the incomplete lobar structures and morphological changes caused by diseases, the lobe segmentation still encounters great challenges. Recently, convolution neural network has exerted a tremendous impact on medical image analysis. Nevertheless, the basic convolution operations mainly obtain local features that are insufficient for accurate lobe segmentation. The idea that the global features are equally crucial especially when lesions appear is considered. Here, a dual‐attention V‐network named DAV‐Net for pulmonary lobe segmentation is proposed. First, a novel dual‐attention module to capture global contextual information and model the semantic dependencies in spatial and channel dimensions is introduced. Second, a progressive output scheme is used to avoid the vanishing gradient phenomenon and obtain relatively effective features in hidden layers. Finally, an improved combo loss is devised to address input and output lobe imbalance problem during training and inference. In the evaluation using the LUNA16 dataset and our in‐house dataset, the proposed DAV‐Net obtains Dice similarity coefficients of 0.947 and 0.934, respectively; these values are superior to those obtained by existing methods.
Medical image fusion and noise suppression with fractional‐order total variation and multi‐scale decomposition
Authors: Zhang Xuefeng , Yan Hui
Published: February 2021

Fusion and noise suppression of medical images are becoming increasingly difficult to be ignored in image processing, and this technique provides abundant information for the clinical diagnosis and treatment. This paper proposes a medical image fusion and noise suppression model in pixel level. This model decomposes the original image into a noiseless base layer, a large‐scale noiseless detail layer and a small‐scale detail layer which contains details and noise information. The fractional‐order derivative and saliency detection are used to construct the weight functions to fuse the base layers. The proposed total variation model combines the fractional‐order derivative to fuse the small‐scale detail layers. The mathematical properties and time complexity of the total variation model are also analysed. And choose‐max method is used to fuse the large‐scale detail medical layers simply. Our approach is based on fractional‐order derivative, which enables keep more information and decrease blocky effects more effectively compared with the integer‐order derivative. To verify the validity, the proposed method is compared with some fusion methods in the subjective and objective aspects. Experiments show that the proposed model fuses the source information fully and decreases noise cleanly.
Integrated multifunctional properties of polypropylene composites by employing three‐dimensional flower‐like MgO with hierarchical surface morphology
Authors: Zha Jun‐Wei , Cheng Qi , Zhai Jin‐Tao , Bian Xingming , Chen George , Dang Zhi‐Min
Published: February 2021

Polymer nanocomposites have attracted increased attention for use in the field of high‐voltage direct current (HVDC) cable insulation. To study the use of polymer nanocomposites for this purpose, 3D flower‐like MgO (flower‐MgO) particles with hierarchical surface morphology are first synthesised. Polypropylene (PP) was simultaneously mixed with styrene‐(ethylene‐co‐butylene)‐styrene triblock copolymer (SEBS) and flower‐MgO to obtain PP/SEBS/flower‐MgO composites. The microstructural, thermal, electrical, and mechanical properties of the obtained nanocomposites were then studied in detail. The results showed that flower‐MgO particles loaded at low concentration were well dispersed in the PP/SEBS matrix. The incorporation of flower‐MgO particles has been found to significantly suppress the injection of homocharges and strengthen the ability to release the charge, thus containing accumulation of the space charge. The DC breakdown strength of PP/SEBS/flower‐MgO composites was increased to 323 MV/m. Meanwhile, the tensile strength and elongation at break of the obtained composites was improved by loading 0.5 phr flower‐MgO because of the synergistic toughening effects of SEBS and MgO. The investigation demonstrates the immense potential to replace nonrecyclable cross‐linked polyethylene as an HVDC cable insulating material.
A novel sizing inherits allocation strategy of renewable distributed generations using crow search combined with particle swarm optimization algorithm
Authors: Farh Hassan M. H. , Eltamaly Ali M. , Al‐Shaalan Abdullah M. , Al‐Shamma'a Abdullrahman A.
Published: February 2021

In
this study, a new distributed generation sizing that inherits the allocation
strategy for the IEEE 30‐bus benchmark system is proposed. The hybrid crow
search‐particle swarm optimization technique would select the optimal buses
through the automatic cancelation of the unfeasible load buses. Additionally,
it performs sizing that inherits allocation for minimum costs and transmission
losses. Also, it selects the best distributed generation technology among wind turbines
and photovoltaic energy systems based on the minimum total capital cost. The
proposed strategy outperformed others in terms of total cost alleviation, power
losses reduction, voltage profile improvement, and lines loading mitigation.
L‐band depolarised radar back scattering from Martian topographic surface: A numerical study
Authors: Yang Ying , Liu Yu , Chen Kun‐Shan , Li Jingwen
Published: February 2021

The interaction of radar signals with a planetary surface is critical for the utility of radar data. Herein, a power‐law roughness spectrum is used to model the roughness and an inhomogeneous vertical permittivity to describe the dielectrics from the surface of Mars. Numerical simulations of depolarised radar backscattering are then conducted. To gain a more complete picture of depolarised characteristics, a wide range of surface roughness is considered. Results reveal that the depolarised backscattering is sensitive to the dielectric profiles with –10 dB is observed. The polarization conversion ratio, the ratio of depolarisation to total polarization backscattering, is a sensitive indicator of dielectric profiles and roughness, and thus is useful in retrieving dielectric profile.
Bifurcation control of a minimal model of marine plankton interaction with multiple delays
Authors: Jiang Zhichao , Jie Maoyan
Published: February 2021

Plankton blooms and its control is an intriguing problem in ecology. To investigate the oscillatory nature of blooms, a two-dimensional model for plankton species is considered where one species is toxic phytoplankton and other is zooplankton. The delays required for the maturation time of zooplankton, the time for phytoplankton digestion and the time for phytoplankton cells to mature and release toxic substances are incorporated and the delayed model is analyzed for stability and bifurcation phenomena. It proves that periodic plankton blooms can occur when the delay (the sum of the above three delays) changes and crosses some threshold values. The phenomena described by this mechanism can be controlled through the toxin release rates of phytoplankton. Then, a delay feedback controller with the coefficient depending on delay is introduced to system. It concludes that the onset of the bifurcation can be delayed as negative feedback gain (the decay rate) decreases (increases). Some numerical examples are given to verify the effectiveness of the delay feedback control method and the existence of crossing curve. These results show that the oscillatory nature of blooms can be controlled by human behaviors.
Familienklassenzimmer in Mecklenburg-Vorpommern
Authors: Behrndt Selma-Maria , Brandenburg Bärbel , Schulz André
Published: February 2021

Die Ausbreitung der Familienklassenzimmer (FKZ) in Mecklenburg-Vorpommern begann mit dem Schulversuch an einer Klinikschule in Stralsund und entwickelte sich als echte Erfolgsgeschichte. Mittlerweile leben etwa 50 Schulen in Mecklenburg-Vorpommern das FKZ und begeisterte Eltern werben öffentlich für dieses Projekt.
Familiäre Folgen von Paarproblemen und Strategien zur Prävention
Authors: Roesler Christian
Published: February 2021

In Deutschland gibt es viele Unterstützungsangebote für Familien, jedoch nicht in gleicher Weise für Paare 1. Dabei fördert eine gute elterliche Paarbeziehung nicht nur die Entwicklungsumwelt der Kinder, sondern stellt auch ein hilfreiches Modell für das spätere Gelingen von Paarbeziehungen dar. Deshalb wurden in neuester Zeit viele Programme für die Prävention von Paarproblemen entwickelt 2, um die Beziehungsstabilität zu stärken.
Pflegende Angehörige
Authors: Schieron Martin , Zegelin Angelika
Published: February 2021

Pflegende Angehörige übernehmen den größten Teil der häuslichen Versorgung pflegebedürftiger Menschen in Deutschland. Ihr eigenes Wohlergehen steht dabei jedoch eher nicht im Fokus von Politik und Gesellschaft. Dieser Beitrag blickt auf die gesellschaftliche Bedeutung und die Belastungen pflegender Angehöriger und gibt Impulse zu ihrer Unterstützung, denn die familiäre Pflegesituation kann auch Gegenstand einer Psychotherapie sein.
Successful Regression in Patients with Progressive Keratoconus by Corneal Crosslinking
Authors: Röck Tobias , Konrad Eva-Maria , Röck Daniel , Bramkamp Matthias , Blumenstock Gunnar , Bartz-Schmidt Karl Ulrich
Published: February 2021

Background Since 2019, corneal collagen crosslinking (CXL) is included in the catalog of procedures covered by statutory health insurance in Germany. CXL is an established ophthalmological procedure for the last 20 years. The aim of this investigation was the measurement of progression before and after CXL.

Material und Methods 65 consecutive eyes with progressive keratoconus from 53 patients were included in the retrospective study, which were observed at the University Eye Hospital Tübingen at least two years before and at least two years after CXL. The time of observation took place from October 2009 until March 2018. Parameters of interest had been the best corrected visual acuity (BCVA) and the keratometric values from the elevation maps measured by a Scheimpflug camera.

Results 65 eyes of 53 patients had been documented. The study population included 46 (86.8%) male and 7 (13.2%) female subjects. The mean age was 24 ± 8 years. The averaged observation time between the primary consultation and CXL showed 25 ± 15 months. Preoperatively the mean BCVA pointed out in a significant increase (0.13 ± 0.17 [first visit] vs. 0.23 ± 0.22 [preOP], p < 0.0001) while the mean Kmax resulted in a statistically significant increase (46.34 ± 3.33 dpt [first visit] vs. 48.78 ± 4.17 dpt [preOP], p < 0.0001). The mean thinnest point of the cornea showed a significant decrease (490.48 ± 34.23 µm [first visit] vs. 468.62 ± 29.84 µm [preop], p < 0.0001). Postoperatively the mean BCVA resulted in a significant improvement at the 12th postoperative month in comparison to the preoperative measurement (0.23 ± 0.22 [preOP] vs. 0.16 ± 0.14 [12 months], p = 0.04 respectively 0.17 ± 0.17 [24 months], p = 0.0006). The mean Kmax demonstrated in the 12th
postoperative month a significant reduction (48.78 ± 4.17 dpt [preOP] vs. 47.91 ± 3.41 dpt [12 months], p = 0.0009 respectively 48 ± 4.56 dpt [24 months], p = 0.0051). The mean thinnest point of the cornea indicated a decrease at the 12th postoperative month (468.62 ± 29.84 µm [preOP] vs. 459.82 ± 35.88 µm [12 months], p = 0.0078 respectively 453.47 ± 43.39 µm [24 months], p = 0.0227).

Conclusion CXL is a successful procedure for the therapy of progressive keratoconus.
Säure-Basen-Haushalt und Gelenkerkrankungen
Authors: Vormann Jürgen , Werner Tanja
Published: February 2021

Der pH-Wert des gesunden Menschen ist immens wichtig. Schon geringe Abweichungen führen zu massiven Störungen im Stoffwechsel, die unter Umständen lebensbedrohlich sind. Für den korrekten Ablauf biologischer Funktionen ist es wichtig, ein konstantes Verhältnis zwischen Säuren und Basen aufrechtzuerhalten. Ändert sich die Säurekonzentration, so hat das massive Auswirkungen auf die Aktivität von Enzymen oder die Struktur von Zellmembranen. Das Risiko für eine Schmerzentstehung ist insbesondere dann gegeben, wenn eine ernährungsbedingte Säurebelastung mit einer erhöhten Säureproduktion im Stoffwechsel zusammenkommt. Insgesamt gesehen belegen die Ergebnisse verschiedenster Untersuchungen die Bedeutung eines ausgeglichenen Säure-Basen-Haushalts auch bei Problemen im Gelenkbereich. Die Behebung einer alimentären Azidose durch ausreichende Basenzufuhr sollte Teil einer erfolgreichen Behandlung von Gelenkproblemen sein.
Rückenschmerz: Schmerztherapie nach Liebscher & Bracht
Authors: Bracht Petra , Liebscher-Bracht Roland
Published: February 2021

Bei etwa 80–99 % aller auftretenden Rückenschmerzen kann keine strukturelle Ursache gefunden werden. Die konventionelle Therapie besteht aus der Gabe von Analgetika sowie Physio- und Psychotherapie, bei strukturellen Ursachen auch operativen Verfahren. Die Therapieerfolge sind oft mäßig.

Eine Ursache im Erklärungsmodell der Schmerztherapie nach Liebscher & Bracht liegt u. a. in einer Fehlspannung des Psoas, u. a. durch langes Sitzen und Stehen. Die Therapie beruht auf 2 Säulen: der Osteopressur, um Spannungen zu lösen, und speziellen Übungen zur Engpassdehnung, um die Muskulatur zu dehnen und zu kräftigen. Im Beitrag werden die wichtigsten Übungen bei Rückenschmerzen vorgestellt.
Rate of detection of serrated lesions at colonoscopy in an average-risk population: a meta-analysis of 129,001 individuals
Authors: Huang Junjie , Chan Paul S.F. , Pang Tiffany W.Y. , Choi Peter , Chen Xiao , Lok Veeleah , Zheng Zhi-Jie , Wong Martin C.S.
Published: February 2021

Background and study aims Serrated lesions are precursors of approximately one-third of colorectal cancers (CRCs). Information on their detection rate was lacking as an important reference for CRC screening. This study was a systematic review and meta-analysis to determine the overall detection rate for serrated lesions and their subtypes in average-risk populations undergoing CRC screening with colonoscopy.

Patient and methods MEDLINE and Embase were searched to identify population-based studies that reported the detection rate for serrated lesions. Studies on average-risk populations using colonoscopy as a screening tool were included. Metaprop was applied to model within-study variability by binomial distribution, and Freeman-Tukey Double Arcsine Transformation was adopted to stabilise the variances. The detection rate was presented in proportions using random-effects models.

Results In total, 17 studies involving 129,001 average-risk individuals were included. The overall detection rates for serrated lesions (19.0 %, 95 % CI = 15.3 %–23.0 %), sessile serrated polyps (2.5 %, 95 % CI = 1.5 %–3.8 %), and traditional serrated adenomas (0.3 %, 95 % CI = 0.1 %–0.8 %) were estimated. Subgroup analysis indicated a higher detection rate for serrated lesions among males (22.0 %) than females (14.0 %), and Caucasians (25.9 %) than Asians (14.6 %). The detection rate for sessile serrated polyps was also higher among Caucasians (2.9 %) than Asians (0.7 %).

Conclusions This study determined the overall detection rate for serrated lesions and their different subtypes. The pooled detection rate estimates can be used as a reference for establishing CRC screening programs. Future studies may evaluate the independent factors associated with the presence of serrated lesions during colonoscopy to enhance their rate of detection.
Long-term clinical results of per-oral endoscopic myotomy (POEM) for achalasia: First report of more than 10-year patient experience as assessed with a questionnaire-based survey
Authors: Onimaru Manabu , Inoue Haruhiro , Fujiyoshi Yusuke , Abad Mary Raina Angeli , Nishikawa Yohei , Toshimori Akiko , Shimamura Yuto , Tanabe Mayo , Sumi Kazuya , Ikeda Haruo
Published: February 2021

Background and study aims Since per-oral endoscopic myotomy (POEM) was introduced in 2010, it has become accepted as one of the standard treatments for esophageal achalasia worldwide. This study aimed to present long-term clinical results of POEM over 10 years and evaluate the technique and outcomes at the institution where it was first used in clinical settings.

Patients and methods Questionnaire-based surveys were sent to patients who received POEM in our institution from September 2008 to May 2010. Patient demographics and procedural outcomes and open-ended questions were posed about the postoperative courses, including symptom improvement and recurrence, additional treatments, and post-POEM gastroesophageal reflux disease (GERD) symptoms. Achalasia symptoms and post-POEM GERD symptoms were evaluated with Eckhardt scores and GerdQ systems, respectively.

Results Thirty-six consecutive POEMs were performed in that period and 10-year follow-up data were obtained from 15 patients (41.7 %). Although four cases (26.7 %) required additional pneumatic balloon dilatation (PBD), reduction in post-Eckardt scores were observed in 14 cases (93.3 %). GerdQ score was positive in one patient (6.7 %). Proton pump inhibitors (PPI) were taken by four patients (26.7 %) and their symptoms were well-controlled.

Conclusions Clinical results of POEM over 10 years were favorable regardless of various factors. Symptoms improved even in patients who required additional treatments, suggesting that POEM plays a significant role in treatment of achalasia.
Nachweis verbesserter Patientensicherheit in Deutschland
Authors: Bauer Susanne Helene , Gronemeyer Stefan
Published: February 2021

Das Thema „Patientensicherheit“ wurde bei der Qualitätssicherung im deutschen Gesundheitswesen lange vernachlässigt. Erst 2015 wird der Forderung nach Datentransparenz mit dem Beschluss zur Veröffentlichung strukturierter Qualitätsberichte der zugelassenen Krankenhäuser entsprochen. Ein wesentliches Patienteninteresse, nämlich das an der Behandlungssicherheit, spielt bislang in der Berichterstattung eine untergeordnete Rolle.

Daher untersucht die vorliegende Arbeit, welche Beispiele zum Nachweis verbesserter Patientensicherheit in Deutschland in den letzten 10 Jahren publiziert wurden. Im Rahmen einer systematischen Literaturrecherche wurden dazu 16 Studien identifiziert, die den Erfolg entsprechender Interventionen in 13 Initiativen auch quantitativ nachweisen konnten.
Padded Headgear does not Reduce the Incidence of Match Concussions in
Professional Men’s Rugby Union: A Case-control Study of 417
Cases
Authors: Stokes Keith A. , Cross Matthew , Williams Sean , McKay Carly , Hagel Brent E. , West Stephen W. , Roberts Simon Paul , Sant’Anna Ricardo T. , Morrison Edward , Kemp Simon
Published: February 2021

Concussion is the most common match injury in rugby union. Some players wear
padded headgear, but whether this protects against concussion is unclear. In
professional male rugby union players, we examined: (i) the association
between the use of headgear and match concussion injury incidence, and (ii)
whether wearing headgear influenced time to return to play following
concussion. Using a nested case-control within a cohort study, four seasons
(2013–2017) of injury data from 1117 players at the highest level of
rugby union in England were included. Cases were physician-diagnosed
concussion injuries. Controls were other contact injuries (excluding all
head injuries). We determined headgear use by viewing video footage. Sixteen
percent of cases and controls wore headgear. Headgear use had no significant
effect on concussion injury incidence (adjusted odds ratio=1.05,
95% CI: 0.71–1.56). Median number of days absent for
concussion whilst wearing headgear was 8 days, compared with 7 days without
headgear. Having sustained a concussion in the current or previous season
increased the odds of concussion more than four-fold (odds
ratio=4.55, 95% CI: 3.77–5.49). Wearing headgear was
not associated with lower odds of concussions or a reduced number of
days' absence following a concussion.
Iodine-Mediated Sulfenylation of Imidazo[1,2-a]pyridines with Ethyl Arylsulfinates
Authors: Tang Dong , Sun Jian , Mu Yangxiu , Iqbal Zafar , Hou Jing , Yang Minghua , Yang Zhixiang
Published: February 2021

A simple iodine-mediated approach is reported for the synthesis of sulfenylated imidazo[1,2-a]pyridines through the reaction of imidazo[1,2-a]pyridines with ethyl arylsulfinates under mild conditions. The reaction scope was investigated, and a plausible mechanism is proposed to elucidate the reaction process and activation mode. The results indicate that ethyl sulfinates are efficient sulfur sources for the construction of C–S bonds.
The Effect of Prescription Isodose Variation on Tumor Control and Toxicities in Stereotactic Radiosurgery for Sporadic Vestibular Schwannoma: Propensity Score-Matched Case–Control Study
Authors: Teyateeti Achiraya , Graffeo Christopher S. , Perry Avital , Tryggestad Eric J. , Brown Paul D. , Pollock Bruce E. , Link Michael J.
Published: February 2021

Objective Vestibular schwannoma (VS) treated with Gamma Knife stereotactic radiosurgery (SRS) was typically performed at 50% isodose line (IDL50); however, the impact of IDL variation on outcomes is poorly understood. This study aimed to compare tumor control (TC) and toxicities between treatment at 40% (IDL40) and 50% (IDL50).

Methods Sporadic/unilateral VS patients treated with SRS dose 12 to 14 Gy and prescription isodose volume ≤10cm3 were included. Propensity score matching was applied to IDL40 cohort to generate an IDL50 companion cohort, adjusting for age and prescription isodose volume. After exclusion of patients with follow-up <24 months, there were 30 and 28 patients in IDL40 and IDL50 cohorts, respectively.

Results Median follow-up time was 96 months (24–225 months). Actuarial and radiographic TC rates were 91.8% and clinical TC was 96.2% both at 5 and 10 years. TC was higher in IDL40 cohort but not significant (96.4 vs. 86.7%; p = 0.243). Hearing preservation (HP) rates were 71.9 and 39.2% at 5- and 10-year intervals, with significantly higher rates of HP noted in IDL40 cohort (83.3 vs. 57.1% at 5-year interval; 62.5 vs. 11.4% at 10-year interval; p = 0.017). Permanent facial neuropathy occurred in two patients, both from the IDL50 cohort (3.5%). Rates of post-SRS steroid treatment or shunt placement for hydrocephalus were slightly higher in IDL50 patients (6.9 vs. 17.9%; p = 0.208 and 3.3 vs. 7.1%; p = 0.532).

Conclusion For treatment of VS with SRS, dose prescription at IDL40 or IDL50 provides excellent long-term TC and toxicity profiles. IDL40 may be associated with improved long-term HP.
Familial Chylomicronemia Syndrome-Induced Acute Necrotizing Pancreatitis during Pregnancy
Authors: Coronado Arroyo Julia Cristina , Concepción Zavaleta Marcio José , García Villasante Eilhart Jorge , Kcomt Lam Mikaela , Concepción Urteaga Luis Alberto , Zavaleta Gutiérrez Francisca Elena
Published: February 2021

Acute pancreatitis is a rare condition in pregnancy, associated with a high mortality rate. Hypertriglyceridemia represents its second most common cause. We present the case of a 38-year-old woman in the 24th week of gestation with a history of hypertriglyceridemia and recurrent episodes of pancreatitis. She was admitted to our hospital with acute pancreatitis due to severe hypertriglyceridemia. She was stabilized and treated with fibrates. Despite her favorable clinical course, she developed a second episode of acute pancreatitis complicated by multi-organ dysfunction and pancreatic necrosis, requiring a necrosectomy. The pregnancy was ended by cesarean section, after which three plasmapheresis sessions were performed. She is currently asymptomatic with stable triglyceride levels. Acute pancreatitis due to hypertriglyceridemia represents a diagnostic and therapeutic challenge in pregnant women, associated with serious maternal and fetal complications. When primary hypertriglyceridemia is suspected, such as familial chylomicronemia syndrome, the most important objective is preventing the onset of pancreatitis.
The Role and Controversies of Electroencephalogram in Focal versus Generalized Epilepsy
Authors: Jayaram Shoba , Alkhaldi Modhi , Shahid Asim
Published: February 2021

As early in 1935, Gibbs et al described electroencephalogram (EEG) features of large slow waves seen in “petit mal” seizures and change in background rhythm to a higher frequency, greater amplitude pattern in “grand mal” seizures. Studies have shown many typical EEG features in focal onset as well as generalized epilepsies.2
3 It is usually easy to delineate focal epilepsy cases when EEG onset of seizures is clear as seen in Benign focal epileptiform discharges of childhood.4 However, it is not uncommon to see cases where epileptiform discharges are not very clear. For example, there can be secondary bilateral synchrony or generalized onset of epileptiform discharges in some cases of focal epilepsy5 and nongeneralized EEG features is cases of generalized epilepsy like absence seizures.6

The awareness of occurrence of focal clinical and EEG features in generalized epilepsy is particularly important to help to select appropriate AEDs and also to avoid inappropriate consideration for epilepsy surgery.7 Lüders et al8 have shown that multiple factors like electroclinical seizure evolution, neuroimaging (both functional and anatomical) have to be analyzed in depth before defining an epileptic syndrome. Here, we are providing few examples of different situations where it is still mysterious to figure out focal onset seizures with secondary generalization versus primary generalized epilepsy.
Impact of ERCC2 Gene Polymorphisms on OSCC Susceptibility and Clinical Characteristics
Authors: Tejasvi ML Avinash , Maragathavalli Gopal , Kumar Putcha Uday , Ramakrishna M. , Raghavan Vijaya , CK Anulekha Avinash
Published: February 2021

Background DNA repair systems play an important role in maintaining the integrity of the human genome. Deficiency in the repair capacity due to either mutations or inherited polymorphisms in DNA repair genes may contribute to variations in the DNA repair capacity and subsequently susceptibility to cancer.

Objectives This study aimed to investigate the association between Excision repair cross-complementation groups 2 (ERCC2) single nucleotide polymorphisms (SNPs rs1799793 and rs13181) and the response to platinum-based chemotherapy among patients with oral squamous cell carcinoma (OSCC).

Methodology Polymerase chain reaction‐based restriction fragment length polymorphism analysis was used to determine the polymorphism from a total of 150 OSCC patients and 150 normal tissues of same patients were collected as controls for this study.

Results ERCC2 GA (Asp312Asn) AC (Lys751Gln) genotypes were significantly associated (p = 0.0001 and p = 0.0004, respectively) with OSCC patients, when compared with the controls. These findings suggest that potentially functional SNPs in ERCC2 may contribute to OSCC risk. This study highlights the genetic variant that might play a role in mediating susceptibility to OSCC in this population. An understanding of DNA repair gene polymorphisms might not only enable risk assessment, but also response to therapy, which target the DNA repair pathway.
Clinical Outcomes and Experience of a Multiyear Consecutive Case Series of Total Knee Arthroplasty Procedures Conducted with a Bipolar Sealer System for Hemostasis
Authors: Sah Alexander P.
Published: February 2021

Maximizing hemostasis during total knee replacement procedures remains a key challenge in current practice. Bipolar sealer technology achieves intraoperative hemostasis through tissue sealing and coagulation with adjustable radio frequency energy and a saline-irrigated tip. Optimal surgical site hemostasis is important to avoid potential complications such as hemarthrosis, wound drainage, increased pain, delayed discharge, and readmissions. The aim of this study is to evaluate the safety and effectiveness of the bipolar sealer device in primary knee replacement in the largest consecutive series to date. A consecutive, treatment-control series of subjects who underwent a primary total knee arthroplasty (TKA) utilizing a bipolar sealer for hemostasis, one subgroup with concomitant tranexamic acid (TXA) administration (n = 1599) and one subgroup without TXA administration (n = 3582), compared with a control group of primary TKA under tourniquet only (n = 667). Statistical analyses were performed through two-tailed unpaired t-tests. There was less total postoperative drain output and a lower overall transfusion rate in the bipolar sealer group (807ml ± 428) (2.5%) than the tourniquet only group (1290 ± 658, p = 0.001) (8.4%, p = 0.0001), respectively. Drainage output in bipolar sealer + TXA (450 ± 297 ml) was lower than the other two groups (bipolar sealer 807 ± 428 mL, p = 0.0001; tourniquet only 1290 ± 658 ml, p = 0.0001). The bipolar sealer group had a higher hematocrit at postoperative day 1 (POD1) (bipolar sealer: 33.1 ± 4.3 cc, tourniquet only: 32.5 ± 4.3 cc, p = 0.001) and at discharge (POD2, bipolar sealer: 31.5 ± 3.7 cc, tourniquet only: 30.2 ± 3.9 cc, p = 0.0001). There were zero reported serious adverse events related to hemostasis management in any group. The bipolar sealer system is a safe and effective instrument to achieve intraoperative hemostasis during primary TKA. The bipolar sealer group required significantly fewer postoperative blood product transfusions and maintained a higher hematocrit concentration at the time of discharge compared with subjects treated solely with tourniquet mediated hemostasis. Addition of TXA to local hemostasis methods may further reduce blood loss and transfusion requirements.

Level of Evidence This is a Level III study.
The COVID-19 exams fiasco across the UK: four nations and two windows of opportunity
Authors: Kippin Sean , Cairney Paul
Published: February 2021

All four UK and devolved governments performed a ‘U-turn’ on their COVID-19 school exams replacement policies. After cancelling exams, they sought teacher estimates on their grades, but supported an algorithm to standardise the results. When the results produced a public outcry over unfair consequences, they initially defended their decision but reverted quickly to teacher assessment. We explain these developments by comparing two ‘windows of opportunity’ overseen by four separate governments, in which the definition of the problem, feasibility of each solution, and motive of policymakers to select one over the other lurched dramatically within a week of the exams results. These experiences highlight the confluence of events and choices and the timing and order of choice. A policy solution that had been rejected during the first window, and would have been criticised heavily if chosen first, became a lifeline during the second. As such, while it is important to understand why the standardisation process went so wrong, we focus on why the policymaking process went so wrong.
The history teacher education process in Portugal: a mixed method study about professionalism development
Authors: Solé Glória , Gago Marília
Published: February 2021

The historical and professional identity of prospective history teachers seems to be central to understanding how these future teachers think of their educational action in articulation with their view of what it means to be historically competent in line with the development of historical literacy and more sophisticated historical consciousness. Thus, in the context of the Master’s Degree in History Teaching in the 3rd Cycle of Basic Education and in Secondary Education offered by the University of Minho (Portugal), following an investigative approach characterised by a Mixed Method in a longitudinal framework, data were collected through an open-answer questionnaire followed by a closed-answer questionnaire. The open-answer questionnaire was proposed at the beginning of the training of prospective History teachers and at the end of the same training course. About twenty answers were obtained and, through their analysis, essentially two types of identities emerged: one more in line with management professionalism and another with the emerging democratic professionalism. Based on the qualitative data, which was analysed inductively, a closed-answer questionnaire was created, intended to understand, through quantitative analysis, the ideas of future Portuguese History teachers about the purposes of being a History teacher, what it means to think historically, what kind of History class they identify with, what should students learn in History classes and whether they should use the terms ‘we’ or ‘the Portuguese’ when presenting the proposals for studying the national historical reality. This questionnaire was applied to students from various Master’s Degree courses in History Teaching, in a purposeful sampling considering the location of Portuguese universities, namely the University of Minho, University of Porto, University of Coimbra, University of Lisbon, and NOVA University of Lisbon.
Superconducting neural networks with disordered Josephson junction array synaptic networks and leaky integrate-and-fire loop neurons
Authors: Goteti Uday S. , Dynes Robert C.
Published: February 2021

Fully coupled randomly disordered recurrent superconducting networks with additional open-ended channels for inputs and outputs are considered the basis to introduce a new architecture to neuromorphic computing in this work. Various building blocks of such a network are designed around disordered array synaptic networks using superconducting devices and circuits as an example, while emphasizing that a similar architectural approach may be compatible with several other materials and devices. A multiply coupled (interconnected) disordered array of superconducting loops containing Josephson junctions [equivalent to superconducting quantum interference devices (SQUIDs)] forms the aforementioned collective synaptic network that forms a fully recurrent network together with compatible neuron-like elements and feedback loops, enabling unsupervised learning. This approach aims to take advantage of superior power efficiency, propagation speed, and synchronizability of a small world or a random network over an ordered/regular network. Additionally, it offers a significant factor of increase in scalability. A compatible leaky integrate-and-fire neuron made of superconducting loops with Josephson junctions is presented, along with circuit components for feedback loops as needed to complete the recurrent network. Several of these individual disordered array neural networks can further be coupled together in a similarly disordered way to form a hierarchical architecture of recurrent neural networks that is often suggested as similar to a biological brain.
Study of vacuum ultraviolet emission in helium and helium/nitrogen mixtures
Authors: Fierro Andrew , Lehr Jane , Yee Benjamin , Barnat Ed , Moore Chris , Hopkins Matthew , Clem Paul
Published: February 2021

Helium is frequently used as a working medium for the generation of plasmas and is capable of energetic photon emissions. These energetic photon emissions are often attributed to the formation of helium excimer and subsequent photon emission. When the plasma device is exposed to another gas, such as nitrogen, this energetic photon emission can cause photoionization and further ionization wave penetration into the additional gas. Often ignored are the helium resonance emissions that are assumed to be radiation trapped and therefore not pertinent to photoionization. Here, experimental evidence for the presence of helium atomic emission in a pulsed discharge at ten’s of Torr is shown. Simulations of a discharge in similar conditions agree with the experimental measurements. In this context, the role of atomic and molecular helium light emission on photoionization of molecular nitrogen in an ionization wave is studied using a kinetic modeling approach that accounts for radiation dynamics in a developing low-temperature plasma. Three different mixtures of helium at a total pressure of 250 Torr are studied in simulation. Photoionization of the nitrogen molecule by vacuum ultraviolet helium emission is used as the only seed source ahead of the ionization front. It is found that even though radiation trapped, the atomic helium emission lines are the significant source of photoionization of nitrogen. The significant effect of radiation trapped photon emission on ionization wave dynamics demonstrates the need to consider these radiation dynamics in plasma reactors where self-absorbed radiation is ignored.
On the H-type transition to turbulence—Laboratory experiments and reduced-order modeling
Authors: Cheng Shyuan , Chamorro Leonardo P. , Ansell Phillip J.
Published: February 2021

A series of experiments were conducted to understand the sources of local, high-amplitude velocity fluctuations produced at the late stages of boundary-layer flow transition to turbulence. The laboratory experiments considered the controlled injection of Tollmien–Schlichting (TS) waves into a nearly zero pressure gradient, laminar boundary layer, resulting in H-type transition to turbulence. Proper orthogonal decomposition (POD) was used to extract the energetic coherent structures within the transitional flow field obtained with particle image velocimetry. The first three modes were observed to feature spatial mode shapes consistent with a cross-section of a canonical hairpin vortex structure and were associated with time-dependent amplitudes having consistent peak frequencies with the fundamental TS wave frequency. Higher-order modes exhibited a combination of sub- and super-harmonics of the TS wave frequency and were attributed to flow interactions produced by a hairpin packet. A conditional averaging method was used to establish a reduced-order model for the overshoot phenomena in Reynolds shear stress and turbulence kinetic energy observed at the late transition stage. The lower portion of the large-scale hairpin vortex structure was observed to be primarily responsible for the overshoot mechanisms, which was well captured in a reduced-order model of the velocity field. The first four POD modes were used to create this reduced-order model, which, while only consisting of ≈15% of the total turbulence kinetic energy of the original velocity field, was able to capture ≈85% of the peak Reynolds stress amplitude across the overshoot region.
Ultrafast excited-state dynamics of SnSe2–SnSe composite thin film
Authors: Kumar Manoj , Sharma Prince , Rani Sanju , Kumar Mahesh , Singh V. N.
Published: February 2021

We report the ultrafast carrier dynamics of an SnSe2–SnSe composite thin film (∼150 nm thick) deposited using thermal evaporation of in-house synthesized SnSe2 powder. Raman and UV–visible spectroscopy supports the optical properties (direct and indirect bandgaps of 1.86 eV and 0.96 eV, respectively). Ultrafast transient spectroscopy is used to study the charge excited state dynamics in the SnSe2–SnSe composite thin film in the femtosecond to nanosecond interval. An energy model has been proposed based on the ultrafast transient absorption and the thin film's steady-state absorption studies. This article provides comprehensive knowledge about the excited carriers and their relaxations in 0.9 ps–31.1 ns via different trap states.
Double-sided infrared display using an opaque substrate based on infrared image recognition mechanism
Authors: Choi Yong Kyu , Lim Taekyung , Jeong Sang-Mi , Pak Jeong Hyeok , Ju Sanghyun
Published: February 2021

The human eye cannot recognize the shape of an object behind an opaque substrate; however, by reading and imaging infrared (IR) rays emitted from such an object, its shape behind the opaque substrate can be ascertained. In this study, an infrared double-sided light-emitting display was deposited on an opaque substrate and the transmission characteristics of infrared rays were measured under various conditions, such as changes in the thickness of the opaque substrate, the distance between the opaque substrate and the object, the infrared intensity of the object, and the viewing angle of the object. By selecting an opaque substrate material suitable for an IR display, the IR transmittance and heat diffusivity were improved. Additionally, by controlling the IR intensity of the IR emitter patterned on the opaque substrate, display information of various colors could be expressed from the IR vision, similar to the RGB wavelength separation of visible light. This technology deviates from the stereotype that a double-sided light-emitting display should use a transparent substrate and demonstrates that a double-sided light-emitting display can be made of an opaque substrate material if the light emission characteristics of IR rays are efficiently controlled.
Effect of Si addition on the creep performance of a Ni-based superalloy
Authors: Xiong Wei , Zhou Shengming , Zhang Dong , Huang Zaiwang , Wang Zi , Wu Hongyu , Jiang Liang
Published: February 2021

In this research, the effect of two different per centages of silicon, i.e. 0.08 and 0.3 wt-%, on microstructure and stress rupture life of a Ni-based superalloy was investigated. The results showed that the fraction of eutectic increased from 1.86 to 3.55% with increasing Si content and a higher fraction of eutectic was found on grain boundaries in high Si-bearing alloy. Upon stress rupture at 975°C/225 MPa, cracking initiates and propagates along Laves phases in 0.3 wt-% Si alloy, causing shorter lifetime comparing to that of 0.08 wt-% Si. The microscopic examination uncovered that Si prefers to segregate towards liquid and γ phase, which can explain different rupture lifetimes of two groups of Si-bearing alloys.
Anti-fraud measures in Eastern Africa
Authors: Mykhalchenko Nataliya , Wiegratz Jörg
Published: February 2021

This briefing explores anti-fraud measures (AFMs) in Eastern Africa (Kenya, Rwanda, Tanzania and Madagascar). The second of a three-part briefing series, it complements previous accounts of AFMs in southern Africa and confirms key AFM features that the authors previously identified concerning typical actors and their alliances, major sectors, fraud types and measures against fraud. The evidence suggests an expansion of anti-fraud agencies and initiatives, collecting and sharing more data within and across borders; of official governance of financial and product flows; and of efforts by AFM actors to enable the detection of genuine products, with related controversies among actors with divergent views and interests.