bluuebunny/crossref_metadata_2025 huggingface dataset:
Mathematical modeling and numerical analysis for the higher order Boussinesq system
Authors: Khorbatly Bashar , Lteif Ralph , Israwi Samer , Gerbi Stéphane
Published: February 2022

This study deals with higher-order asymptotic equations for the water-waves problem. We considered the higher-order/extended Boussinesq equations over a flat bottom topography in the well-known long wave regime. Providing an existence and uniqueness of solution on a relevant time scale of order 1/√ε and showing that the solution’s behavior is close to the solution of the water waves equations with a better precision corresponding to initial data, the asymptotic model is well-posed in the sense of Hadamard. Then we compared several water waves solitary solutions with respect to the numerical solution of our model. At last, we solve explicitly this model and validate the results numerically.
Erfahrungen bei der Anwendung motorisierter Marknägel nach
komplexen Extremitätenverletzungen
Authors: Orth Marcel , Mörsdorf Philipp , Fritz Tobias , Braun Benedikt J , Pirpilashvili Vakhtang , Stutz Janine , Veith Nils , Pohlemann Tim , Pizanis Antonius
Published: February 2022

Die Behandlung komplexer Extremitätenverletzungen infolge von
Trümmerfrakturen oder Pseudarthrosen stellt eine besondere Herausforderung
in der Unfallchirurgie dar. Rein interne, motorisierte Implantatsysteme
ermöglichen heutzutage eine patientenorientierte und fortschrittliche
Behandlung solcher Fälle. Der vorliegende Beitrag soll moderne
Behandlungskonzepte komplexer Extremitätenverletzungen vorstellen,
Unterstützung bei der Anwendung neuartiger, motorisierter Marknägel liefern
und Erfahrungen beim Umgang mit Verlängerungs- und Transportnägeln
darstellen. Hierzu wird zunächst die präoperative Planung inkl.
Patientenselektion, Vorstellung interner Verlängerungs- und Transportsysteme
und der wichtigsten Faktoren für die OP-Vorbereitung erläutert. Im Anschluss
werden intraoperative Besonderheiten bei der Implantation motorisierter
Marknägel sowie bei möglichen Folgeeingriffen dargestellt und das
postoperative Prozedere mit konkreten Empfehlungen zur Transport- und
Konsolidierungsphase beschrieben. Abschließend werden die Erfahrungen durch
4 Anwendungsbeispiele veranschaulicht. Der Einsatz interner, motorisierter
Implantate stellt den derzeit letzten Schritt in der Behandlung komplexer
Extremitätenverletzungen dar. Sie verbessern die Lebensqualität betroffener
Patienten und ihre Anwendung wird seitens der Autoren befürwortet. Doch
erfordern diese neuen Implantate ein hohes Maß an Expertise und eine
Anpassung etablierter Behandlungsstrategien bei diesen ohnehin
anspruchsvollen unfallchirurgischen Krankheitsbildern. Weitere
Untersuchungen mit großen Fallzahlen sollten künftig erhoben und die
Implantatforschung zur Lösung fortbestehender Probleme in der Behandlung
komplexer Extremitätenverletzungen intensiv fortgesetzt werden.
Pädiatrische Atemwegschirurgie: Indikationen und
Techniken
Authors: Schweiger Thomas , Evermann Matthias , Roesner Imme , Denk-Linnert Doris-Maria , Klepetko Walter , Hoetzenecker Konrad
Published: February 2022

In der pädiatrischen Atemwegschirurgie sind zahlreiche anatomische
Besonderheiten, spezifische Krankheitsbilder sowie spezielle Operationstechniken
zu beachten. Auch an spezialisierten Zentren sind diese Eingriffe bei
pädiatrischen Patienten eher selten. Ätiologisch handelt es sich meist um
erworbene Stenosen als Folge von Frühgeburtlichkeit, Langzeitintubation oder
-tracheotomie, welche typischerweise in Kindern mit zahlreichen Komorbiditäten
auftreten. Kongenitale Fehlbildungen der Atemwege gehen häufig mit weiteren
Malformationen einher, welche die erfolgreiche Behandlung zusätzlich erschweren.
Voraussetzung zur Behandlung dieser Kinder sollte daher ein multidisziplinäres
Team sein. An erfahrenen Zentren mit entsprechender Infrastruktur kann die
chirurgische Behandlung dieser Kinder mit sehr guten Ergebnissen durchgeführt
werden. So wird bei den meisten Patienten nach chirurgischer Behandlung eine
sehr gute Lebensqualität ohne Notwendigkeit einer Langzeittracheostomie
erreicht. Diese Übersichtsarbeit fasst die wichtigsten Indikationen, sowie die
häufigsten Operationstechniken in der pädiatrischen Atemwegschirurgie
zusammen.
De Novo Skull Base Atypical Meningioma: Incidence and Outcome
Authors: James Z. , Makwana M. , Hayhurst C.
Published: February 2022

Objective Atypical meningiomas are uncommon in skull base practice and present a management challenge. We aimed to review all de novo atypical skull base meningioma cases within a single unit to analyze presentation and outcome.

Methods A retrospective review of all patients undergoing surgery for intracranial meningioma identified consecutive cases of de novo atypical skull base meningioma. Electronic case records were analyzed for patient demographics, tumor location and size, extent of resection, and outcome. Tumor grading is based on the 2016 WHO criteria.

Results Eighteen patients with de novo atypical skull base meningiomas were identified. The most common tumor location was the sphenoid wing in 10 patients (56%). Gross total resection (GTR) was achieved in 13 patients (72%) and subtotal resection (STR) in 5 patients (28%). There was no tumor recurrence recorded in patients who had undergone GTR. Patients with tumors >6 cm were more likely to undergo a STR as opposed to a GTR (p < 0.01). Patients who had undergone a STR were more likely to have postoperative tumor progression and be referred for radiotherapy (p = 0.02 and <0.01, respectively). On multiple regression analysis, tumor size is the only significant factor correlating with overall survival (p = 0.048).

Conclusion The incidence of de novo atypical skull base meningioma is higher in our series than currently published data. Tumor size was a significant indicator for patient outcome and extent of resection. Those undergoing a STR were more likely to have tumor recurrence. Multicenter studies of skull base meningiomas with associated molecular genetics are needed to guide management.
Oral Tegafur-Uracil Combination plus Leucovorin versus Other Fluoropyrimidine Agents in Colorectal Cancer: A Systematic Review and Meta-Analysis
Authors: Kataria Satya Pal , Nagar Mukesh , Verma Shikha , Purohit Vinay
Published: February 2022

Background Systemic fluoropyrimidines, both oral and intravenous, are an integral part of colorectal cancer (CRC) management. They can be administered either with curative or palliative intent.

Objectives This article examines the literature to analyze the efficacy and safety of the oral fixed-dose combination of uracil and tegafur (UFT)/leucovorin (LV) compared with other fluoropyrimidine agents, with an intention to implement the findings into the current treatment algorithms for CRC.

Methods An exhaustive systematic literature search was performed for prospective studies using PUBMED, Cochrane Library, and EMBASE database. Studies which met eligibility criteria were shortlisted and grouped into chemotherapy given for curative or palliative intent.

Results Eight trials were shortlisted involving 4,486 patients for the analysis. There was no difference between UFT/LV and other fluoropyrimidines in the primary endpoints—disease-free survival (hazard ratio [HR] 1.01; 95% confidence interval [CI] 0.90–.15; p = 0.81) and progression-free survival (HR 0.87; 95% CI 0.66–.66; p = 0.35) for curative and palliative intent CRC patients, respectively. In secondary analyses, there was no significant difference observed between UFT and other fluoropyrimidines in overall survival in CRC patients with curative intent (HR 1.04; 95% CI 0.88–1.23; p = 0.63) and palliative intent (HR 1.02; 95% CI 0.97–1.06; p = 0.42) . In the safety analysis, we found significantly lesser patients on UFT/LV had stomatitis/mucositis (odds ratio [OR] 0.20; 95% CI 0.05–0.85; p = 0.03), fever (OR 0.46; 95% CI 0.29–0.71; p < 0.001), infection (OR 0.42; 95% CI 0.24–0.74; p < 0.01), leukopenia (OR 0.04; 95% CI 0.00–0.95; p = 0.05), febrile neutropenia (OR 0.03; 95% CI 0.00–0.24; p = 0.001), and thrombocytopenia (OR 0.14; 95% CI 0.02–0.79; p = 0.03) compared with other fluoropyrimidines.

Conclusion Oral UFT/LV is equally efficacious to other fluoropyrimidines, especially intravenous 5-fluorouracil, in the management of early as well as advanced CRC patients. Importantly, UFT/LV has a superior safety profile compared with other fluoropyrimidines in terms of both hematological and nonhematological adverse events.
A Comparative Study between the Postoperative Complications of Stripping Esophagectomy and Classic (Orringer's Technique) Esophagectomy
Authors: Ahmadinejad Mojtaba , Hashemi Mozaffar , Tabatabai Abbas
Published: February 2022

Recent studies have suggested that morbidity and mortality rate of transhiatal esophagectomy is comparable to that of thoracotomy, calling the need for the modifications in the surgical procedures. Our methodology includes stripping of esophagus by nasogastric tube to reduce the manipulation of thoracic cavity and associated complications. We also present the comparison between the stripping and classic (Orringer's technique) esophagectomy.

Patients presenting esophageal carcinoma from 2015 to 2017 were the target of this study. Patients undergoing esophagectomy were randomized to have classic or stripping esophagectomy. Operating time, manipulation time, blood losses during the surgery, duration of hospitalization, volume intake, hypotension time, arrhythmia, and transfusion were the recorded parameters. Complications, such as anastomotic leak, cardiac effects, and morbidity, were also studied. Seventy patients were referred for transhiatal esophagectomy for esophageal carcinoma at the Al Zahra Hospital. Mean ages of patients in the stripping and Orringer group were 64.00 ± 10.57 and 57.42 ± 12.20 years, respectively. Manipulation time, operating time, blood loss during the surgery, and transfusion were statistically significant variables between the two groups. Although volume intake and duration of hospitalization were not significantly different parameters, however, betterment in the outcomes was evident. Substantial decrease in overall complications via stripping method was obtained, hence can be suggested as an effective alternative, to remove the need of thoracotomy, for transhiatal esophagectomy.
Ruptured Left Ovarian Teratoma Presenting as an Irreducible Right Inguinal Hernia
Authors: Mithi Mohamed Taher , Deshpande Swanit Hemant , Mithi Taher Abbas , Deshpande Swarika Hemant
Published: February 2022

Teratomas of the ovary rarely present as inguinal hernias. Teratomas most commonly occur in the gonads or along with midline structures. Although the majority are asymptomatic, complications such as spontaneous rupture are known to occur. We present a previously unreported case of a ruptured ovarian teratoma presenting as an irreducible inguinal hernia. The patient underwent an open exploratory laparotomy with left oophorectomy, and the right inguinal hernia was repaired in the same setting with a separate inguinal incision.
Therapeutic Outcomes in High-Grade B-Cell Lymphoma, NOS: Retrospective Analysis
Authors: Karunakaran Parathan , Selvarajan Gangothri , Kalaiyarasi Jayachandran Perumal , Mehra Nikita , Sundersingh Shirley , Dhanushkodi Manikandan , Kesana Sivasree , Kannan Krishnarathinam , Ganesan Trivadi S , Radhakrishnan Venkatraman , Sagar Tenali Gnana
Published: February 2022

The nomenclature high-grade non-Hodgkin's lymphoma was repurposed in the World Health Organization (WHO) 2016 update as high-grade B cell lymphoma (HGBL). However, among the HGBL entities HGBL, not otherwise specified (NOS) remains a poorly described entity with a lack of literature regarding its treatment and prognosis.

The baseline characteristics, treatment, and outcome of HGBL, NOS cases were analyzed. Thirty HGBL, NOS patients were diagnosed between January 2017 and December 2019. Their median age was 49.3 years, and 30% had advanced IPI. The majority received R-CHOP chemotherapy, while five patients received dose-adjusted R-EPOCH. At a median follow-up of 15 months, nine patients had disease progression or relapse. EFS and OS were 22 months (12.1–31.9 months) and 37 months (29.4–44.0 months) respectively. Only NCCN-IPI ≤ 2 showed significant influence on the outcome. The results were similar to the outcomes previously reported.

This study highlights the importance of NCCN-IPI in ascertaining the prognosis of HGBL, NOS. The literature review suggests that more intensive chemotherapy is ideal for HGBL, NOS. However, prospective trials are needed to prove whether the treatment of HGBL, NOS can be tailored based on NCCN-IPI.
Prognostic Factors of Granulosa Cell Tumors: A Retrospective Study in a Tertiary Care Cancer Centre of Eastern India
Authors: Kulkarni Rohini V. , Nayak Bhagyalaxmi , Parija Jita , Mohapatra Janmejaya , Mohapatra Manoranjan , Padhy Ashok
Published: February 2022

Background and Aims The main objective of this study was to analyze the clinicopathological profile and prognostic factors of granulosa cell tumor (GCT).

Method All the cases of ovarian cancer which were seen at our institute between January 2000 and December 2017 were reviewed. Data were analyzed with failure-free survival (FFS) as the primary end point.

Results GCTs consisted of 2.66% of all ovarian cancers at our institute. The median age was 43 years. Majority of the patients (62.5%) were unstaged. Six patients (25%) had a fertility-preserving procedure. Forty two percent of the patients received adjuvant chemotherapy. Thirty eight percent of the patients developed recurrence. Considering tumor-related prognostic factors, there was a statistically significant decrease in FFS with the presence of hemorrhage (p = < 0.001), larger tumors (p = 0.042), and juvenile variant (p = 0.002). On the contrary, when treatment-related factors were considered, there was no statistically significant improvement in FFS with the performance of lymphadenectomy (p = 0.218), omentectomy (p = 0.453), fertility sparing surgery (p = 0.152), or administration of adjuvant chemotherapy (p = 0.45).

Conclusion Inherent tumor-related biological factors tend to play a more important role compared with treatment-related factors in GCTs. Hence, the traditional practice of performance of extensive staging procedures and routine adjuvant chemotherapy should be reviewed. Fertility-preserving surgery appears safe to be offered in early stages when desired. Although it is common knowledge that GCTs tend to be hemorrhagic tumors, this factor has not been well recognized as a prognostic indicator till date. Our study sheds some light on this aspect. Since these tumors have a tendency toward late recurrences, a long follow-up is prudent.
Use of Triggers on in vitro Fertilization and Evaluation of Risk Factors for Sub-Optimal Maturation Rate
Authors: Matsumoto Larissa , Yamakami Lucas Yugo Shiguerhara , Turco Edson Guimarães Lo , Benetti-Pinto Cristina Laguna , Yela Daniela Angerame
Published: February 2022

Objective To compare the oocyte maturation rate in the treatment of in vitro fertilization (IVF) in terms of the use of human chorionic gonadotropin (hCG), agonist gonadotropin-releasing hormone (GnRH) and dual trigger and to evaluate the associated risk factors for sub-optimal maturation rates.

Methods A retrospective cohort study with 856 women who underwent IVF. They performed oocyte retrieval and were classified into 3 groups (1 - hCG, 2 - GnRH agonist, 3 - dual trigger). The primary outcome was maturation rate per trigger, and the secondary outcomes were the pregnancy rate per oocyte retrieval and the correlations between low maturation rate as well as the clinical and treatment characteristics of women.

Results The maturation rate was 77% in group 1; 76% in group 2, and 83% in group 3 (p = 0.003). Group 2 showed women with better ovarian reserve, greater number of oocytes collected, and more mature oocytes and embryos compared with the other groups (p < 0.001). The cumulative clinical pregnancy rate was no different between the groups (p = 0.755). Low ovarian reserve and low doses of follicle-stimulating hormone (FSH) administered during the stimulus were associated with a higher chance of null maturation rate.

Conclusion The oocyte maturation rates and IVF results were similar in all groups. Low ovarian reserve is associated with the worst treatment results.
Successful Management of a Post-Choledochal Cyst Excision Pancreatic Fistula in an Adult Patient: A Case Report and Literature Review on Risk Factors
Authors: Anbarasu Aravinth , Deshpande Aparna
Published: February 2022

Introduction Choledochal cyst is a premalignant condition and surgical excision with biliary enteric anastomosis is the standard of care. Surgical treatment in adults may be difficult due to associated biliary pathology and high incidence of postoperative complications is reported. Postoperative pancreatic fistula (POPF) is a rare early complication following choledochal cyst excision.

Material and Methods A 23-year-old male patient was operated for a Todani type IV-A choledochal cyst with anomalous pancreaticobiliary junction. Cyst excision with hepaticojejunostomy was performed. Distal stump closure was technically challenging due to extreme thickening of the cyst wall with neovascularization. On postoperative day 2, patient developed tachycardia and progressive tachypnea with 200 mL of pancreatic fluid in the drain. Endoscopic pancreatic stenting was attempted but was technically not possible. At reexploration, leak from oversewn distal cyst stump was identified and the suture line was reinforced. After the second surgery the patient was hemodynamically stable but continued to have a low output pancreatic fistula for few days which was managed conservatively successfully. We conducted a review of English literature with an aim to identify the risk factors and predictors of pancreatic fistula following cyst excision. An electronic search was performed in Medline and Google Scholar during September 2020 and available literature since January 2000 were reviewed. The keywords used were “pancreatic fistula” and “choledochal cyst.”

Results Preoperative cholangiography (magnetic resonance cholangiopancreotography/endoscopic retrograde cholangiopancreatography) is essential to know the extent of cyst and delineate biliary pancreatic junction. Literature review including our case revealed that Todani type I-c, type IV, and forme fruste type of choledochal cyst are at high risk of pancreatic injury and POPF. Recurrent cholangitis makes excision technically more challenging and complete removal is not always possible.

Conclusion Postoperative pancreatic fistula can be anticipated in select group of patients with high-risk preoperative findings. Chronic inflammation due to recurrent cholangitis promotes scarring and neovascularization which adds to surgical complexity. Operative technique in these high-risk patients needs further refinement.
Manual Reduction of Incarcerated Abdominal Wall Hernias. A Feasible Option during COVID-19 Pandemic: A Prospective Study
Authors: Bouliaris Konstantinos , Efthimiou Matthaios , Chatzikomnitsa Paraskevi , Kolla Christina , Doudakmanis Christos , Zervas Konstantinos , Giaglaras Anargiros , Koukoulis Georgios D.
Published: February 2022

Background Incarcerated hernia is a common surgical emergency with considerable morbidity or even mortality. Manual reduction (taxis) and elective surgery could be an alternative management approach. This study examines the role of taxis with the adjuvant use of the visual analogue scale (VAS) score in treating incarcerated hernias and thereby decreasing the emergency surgery rate, especially during the novel coronavirus disease 2019 (COVID-19) pandemic.

Methods All adult patients admitted to the emergency department of our hospital with incarcerated hernias of anterior abdominal wall were prospectively submitted to hernia manual reduction. The VAS score was used as an adjuvant tool for monitoring the success of this maneuver. Patients with successful taxis and low VAS score were hospitalized for a 24-hour period of observation. On their discharge, they were scheduled for an elective hernia repair. Patients with unsuccessful taxis or with less than a 50% reduction in VAS score after successful taxis were submitted to emergency surgical repair. Age, sex, type of hernias, time until taxis, VAS scores before and after taxis, length of hospital stay, and adverse events for both groups were recorded.

Results Between September 2018 and September 2020, 86 patients with incarcerated hernias were included. The types of hernias were incisional in 8 patients, umbilical in 15 patients, inguinal in 56 patients, and femoral in 7 patients. Taxis was successful in 66% of patients with a mean reduction in VAS score from 83 to 17 mm. Following successful taxis, patients were hospitalized for a 24-hour period of observation. No taxis-related complications were observed. Fifty-two patients were safely discharged from hospital and scheduled for an elective repair during the first month. Thirty-four patients were operated emergently. Five patients had successful taxis but with a reduction of posttaxis VAS score less than 50% (a mean reduction from 86 to 62 mm), while taxis failed in twenty-nine patients. Patients with emergency surgery had longer time until reduction and longer stay of hospitalization. In this group, two patients required admission to the intensive care unit while one patient died.

Conclusion In this protocolized approach, taxis is a safe and feasible option for most patients with incarcerated hernias. It should be kept in our armament, especially in times when emergency surgery capabilities are under strain like the ongoing COVID-19 pandemic.
Clinical and Radiological Features of Cronkhite–Canada Syndrome: A Case Report
Authors: Lokesh Lokesh , Jindal Vikas , Das Prasenjit , Yadav Rajni , Makharia Govind K. , Madhusudhan Kumble Seetharama
Published: February 2022

Cronkhite–Canada syndrome is a rare non-hereditary disease characterized by gastrointestinal hamartomatous polyposis and protein-losing enteropathy. The presenting symptoms are onychodystrophy, skin pigmentation, alopecia, weight loss, and diarrhea. Diagnosis is suggested by a combination of clinical, imaging, and endoscopy findings, and histology is necessary for confirmation. Here we describe a case of a 54-year-old man presenting with watery diarrhea, colicky abdominal pain, nasal obstruction, and weight loss for 6 months. Endoscopy showed multiple polyps in the stomach, duodenum, and colon. These were seen on computed tomography (CT) enterography along with polyps in the small bowel. A final diagnosis was made after the biopsy.
KI in der Medizin: Datenhungrige Helfer im Hintergrund
Authors: Hohnstein Aileen
Published: February 2022

Der Begriff künstliche Intelligenz ist in aller Munde. Seit einigen Jahren finden Medizinprodukte, die auf KI-Algorithmen basieren, ihren Weg in die Krankenhäuser. Aber was genau steckt hinter dieser Technologie, welche Chancen und auch Risiken liegen darin? Ein Blick in ein Forschungsfeld, das viel für die Zukunft verspricht.
Long Covid: Einen Königsweg für die Behandlung gibt es nicht
Authors: Reisinger Kathrin
Published: February 2022

Während die pandemischen Fallzahlen weiterhin hoch sind und eine Sars-CoV-2-Mutation die nächste ablöst, bleiben nach akuter Erkrankung hunderttausende Patienten zurück – betroffen von Long Covid oder Post Covid. Längst ist klar, dass Long Covid eine Erkrankung mit vielen Gesichtern ist. Symptome, Schweregrade und Therapien sind inzwischen so vielfältig, dass die meisten Patienten monatelang umfassend internistisch betreut werden müssen.
Double-layer balance system of voltage source series energy storage battery pack for electric vehicles
Authors: Yang Chuankai , Zhang Xiaolan , Yang Chuanqi , Xin Lei , Liu Haolu , Li Yida
Published: February 2022

Inconsistent material properties or structural composition of batteries may occur in the process of battery manufacturing, storage, and operation. The resulting inconsistency in the battery cells will make the series battery packs in electric vehicles have the hidden danger of accidents. This paper designs a two-layer combination balance system with fast speed and simple structure based on the analysis of graph theory. On the one hand, the system is based on a distributed topology to provide a direct energy transmission path for non-adjacent battery cells in the battery pack to fully improve the balancing speed. On the other hand, it takes full advantage of the fast speed of centralized topology to avoid the increase in control complexity caused by too many balancing paths. Finally, a suitable switching frequency and a balancing capacitor were selected based on the simulation experiment. The prototype of the double-layer combined balance system was designed and built to verify its faster speed and good effect.
Standing waves in the plenum of an open jet wind tunnel: Resonance and self-excited oscillation
Authors: Jin Ling , Deng Xiao Bing , Wang Xunnian , Gu Yunsong , Liang Yong , Lian Zhenzeng
Published: February 2022

The low-frequency pressure pulsations in a large low-speed open jet wind tunnel were studied using a 1:20 scaled model wind tunnel. It was found that plane pressure standing waves existed in all three directions of the wind tunnel’s plenum. It was confirmed that the large pressure pulsations in the transverse direction of the plenum were caused by the resonance of the plane pressure standing waves in that direction with the edgetone feedback (vortex-sound feedback between the nozzle and the collector). The analysis of the standing waves in the vertical direction of the plenum suggested that they might come from self-excited oscillations. For the model wind tunnel with a 1:20 strictly scaled collector, the standing waves in the transverse direction of the plenum were much stronger than those in the other two directions. By increasing the width of the collector, the intensity of the standing waves in the transverse direction was significantly reduced to a level similar to that of the standing waves in the vertical direction. It was also found that the standing waves in the transverse direction were significantly enhanced after a floor was added to the test section.
Experimental and theoretical research on relation between magnetic and mechanical property of structural I-steel column
Authors: Ge J. , Su S. Q. , Wang W. , Guo H.
Published: February 2022

As an ignored physical property, the metal magnetic memory signal has the potential for non-destructive testing in the future. To get the variation characteristic of magnetic signals under different loads, the normal components of surface spontaneous magnetic signals Hp(y) of the Q235 I-steel column were measured online. In this paper, the variation law of Hp(y) with stress was investigated in the position of the point of contraflexure and stress concentration. The physical mechanism between its magnetic property and mechanical property was established at the elastic and plastic stages. Experimental results show that Hp(y) reaches the extreme value in the position of stress concentration, where the magnetic field gradient K presents the zero-crossing phenomenon along with the peak–peak value phenomenon on the left and right sides. In the position of the point of contraflexure, when the Hp(y) curve reaches the extreme value, the corresponding equivalent uniaxial stress σeq is 54 MPa, which is in good agreement with the Jiles–Atherton (J–A) model. Characteristic parameters Kmax, ζ, and η can reflect the extent of damage of the specimen. In the position of stress concentration, Hp(y) values decrease sharply at the early plastic stage. The analysis shows that the distribution regularity of Hp(y) at the elastic stage is in good agreement with the J–A model. The modified J–A model is consistent with the experimental results at the plastic stage.
High performance thin-film lithium niobate modulator on a silicon substrate using periodic capacitively loaded traveling-wave electrode
Authors: Chen Gengxin , Chen Kaixuan , Gan Ranfeng , Ruan Ziliang , Wang Zong , Huang Pucheng , Lu Chao , Lau Alan Pak Tao , Dai Daoxin , Guo Changjian , Liu Liu
Published: February 2022

Thin-film lithium niobate (TFLN) based traveling-wave modulators maintain simultaneously excellent performances, including large modulation bandwidth, high extinction ratio, low optical loss, and high modulation efficiency. Nevertheless, there still exists a balance between the driving voltage and modulation bandwidth. Here, we demonstrate an ultra-large bandwidth electro-optic modulator without compromising the driving voltage based on the TFLN platform on a silicon substrate, using a periodic capacitively loaded traveling-wave electrode. In order to compensate the slow-wave effect, an undercut etching technique for the silicon substrate is introduced to decrease the microwave refractive index. Our demonstrated devices represent both low optical and low microwave losses, which leads to a negligible optical insertion loss of 0.2 dB and a large electro-optic bandwidth with a roll-off of 1.4 dB at 67 GHz for a 10 mm-long device. A low half-wave voltage of 2.2 V is also achieved. Data rates up to 112 Gb s−1 with PAM-4 modulation are demonstrated. The compatibility of the proposed modulator to silicon photonics facilitates its integration with matured silicon photonic components using, e.g., hybrid integration technologies.
Simultaneous control of plasmon–exciton and plasmon–trion couplings in an Au nanosphere and monolayer WS2 hybrid system
Authors: Hou Liping , Wang Qifa , Zhang Hanmou , Wang Puhui , Gan Xuetao , Xiao Fajun , Zhao Jianlin
Published: February 2022

Simultaneous control of plasmon–exciton and plasmon–trion couplings is fundamentally interesting for tailoring the strong light–matter interaction at the nanoscale and is intriguing for developing high-efficiency optoelectronic and nonlinear photonic devices. Here, we integrate the monolayer WS2 with the Au nanosphere to take full advantages of both the strong excitonic effect and local field enhancement effect to realize strong resonance couplings between the dipolar plasmon mode and the exciton, as well as the trion, at room temperature. Interestingly, from the dark-field scattering spectrum, a transition from the dominated plasmon–exciton coupling to the plasmon–exciton–trion coupling in the hybrid system by simply increasing the radius of the nanosphere is revealed. This evolution of the scattering spectrum is further analyzed using the coupled-oscillator model to extract Rabi splittings of 89 and 48 meV for plasmon–exciton and plasmon–trion couplings, implying that the hybrid system enters the moderate coupling region. The moderate coupling imparts the hybrid system with a remarkable light-emitting capacity, rendering 1265- and 680-fold photoluminescence (PL) enhancement for the exciton and trion emissions, respectively. Our findings provide a facile way for the manipulation of excitonic quasiparticles in semiconductors at room temperature.
Understanding the effects of annealing temperature on the mechanical properties of layers in FAI-rich perovskite solar cells
Authors: Oyelade O. V. , Oyewole O. K. , Olanrewaju Y. A. , Ichwani R. , Koech R. , Oyewole D. O. , Adeniji S. A. , Sanni D. M. , Cromwell J. , Ahmed R. A. , Orisekeh K. , Anye V. C. , Soboyejo W. O.
Published: February 2022

This paper uses a combination of experiments and theory to study the effects of annealing temperature on the mechanical properties of hybrid organic–inorganic perovskites (HOIPs). We examined the mechanical (hardness and Young’s modulus), microstructural, and surface topography properties of the HOIP film at different annealing temperatures ranging from 80 to 170 °C. A mechanism-based strain gradient (MSG) theory is used to explain indentation size effects in films at different annealing temperatures. Intrinsic film yield strengths and hardness values (deduced from the MSG theory) are then shown to exhibit a Hall–Petch dependence on the inverse square root of the average grain size. The implications of the results are then discussed for the design of mechanically robust perovskite solar cells.
Application of improved particle swarm optimization algorithm in TDOA
Authors: Liang Zhen-dong , Yi Wen-jun
Published: February 2022

In order to improve the location accuracy of passive sound source location technology in a complex environment, an improved particle swarm optimization algorithm is proposed. Aiming at the nonlinear optimization problem in the time difference of the arrival location algorithm, based on the classical particle swarm optimization algorithm, combined with the fitness function and the method of adaptive changing parameters, the improved particle swarm optimization algorithm can not only effectively solve the problem that particle swarm optimization is sour and easy to fall into local optimization but also accurately locate the position of the passive sound source. The feasibility and stability of the algorithm are verified by actual simulation.
How mobility of transmitter and receiver affects the communication quality
Authors: Isik Ibrahim
Published: February 2022

Nano-networks focused on communication of nano-sized devices (nanomachines) are a new communication concept, which is known as Molecular Communication (MC) in the literature. In this study, on the contrary to the literature, a mobile MC model is proposed in a diffusion environment by using 5 bits because it is known that besides the molecules, which transport information between the transmitter and receiver, the transmitter and receiver parts of the biological cells are mobile in the blood or any other fluid media. In this study, both the transmitter and the receiver can be chosen as mobile and/or fixed for some specific duties, such as drug delivery systems. Their mobility values can also be regulated separately for the proposed mobile MC model. The proposed model is analyzed for the different situations of the transmitter and receiver (fixed and/or mobile) by considering the fraction of the received molecules. Finally, the number of bits, the time step, and the bit duration are analyzed to find the best MC model. It is concluded that when the receiver and the transmitter are mobile, the distance between them changes, and finally, this affects the probability of the received molecules at the receiver.
Insights into the phylogenetic position and phylogeography of the monospecific skink-parasite genus
Authors: Sata Naoya , Nakano Takafumi
Published: February 2022

Neoentomelas asatoi Hasegawa, 1989 is a parasitic nematode that infests only the scincid lizard Ateuchosaurus pellopleurus (Hallowell, 1861) that inhabits the forest floor in the Northern and Central Ryukyu Archipelago, Japan. As a member of Rhabdiasidae, the reproductive mode of N. asatoi is characterised by the alternation of the protandrous hermaphroditic mode and gonochoristic mode throughout the life cycle. The intrafamily phylogenetic position and intraspecific diversity of this nematode species were inferred by molecular phylogenetic analyses. The results revealed the phylogenetic distinctiveness of Neoentomelas Hasegawa, 1989 in Rhabdiasidae that supports the unique generic status of Neoentomelas within the family. The intraspecific phylogenetic analyses of N. asatoi revealed a minor concordant phylogenetic pattern with the host and mosaic geographic arrangement of the major clades that was discordant with the host. The analyses and distribution pattern of subclades suggested that this geographic arrangement can be explained by at least three dispersal events and subsequent switching to indigenous host populations. Colonisation events might be promoted by the high establishment rate of new populations stemming from the parthenogenesis-like reproduction mode of N. asatoi. This study demonstrated that reproductive modes can affect the intraspecific genetic diversity of parasites.
Characterisation and cross-amplification of sex-specific genetic markers in Australasian Egerniinae lizards and their implications for understanding the evolution of sex determination and social complexity
Authors: Bouffet-Halle Alix , Yang Weizhao , Gardner Michael G. , Whiting Martin J. , Wapstra Erik , Uller Tobias , While Geoffrey M.
Published: February 2022

Sex is a pervasive factor that underpins functional phenotypic variation across a range of traits. Although sex can usually be distinguished morphologically, in some species this is not possible. The development of genetic markers for sex identification is, thus, key if we are to incorporate sex into an understanding of ecological or evolutionary process. Here we develop genetic markers for the identification of sex within an iconic Australian lizard group, the Egernia group, which is notable for its complex social behaviour. We used restriction-site associated DNA sequencing to characterise sex-specific genetic sequences for a key member of the group, Liopholis whitii, and designed primers for four of these putative sex-specific sequences. These primers amplified across some, but not all, species of the group. Our results provided several important insights. They suggest conservatism of a XX/XY sex determination system within the group as well as sex-specific genomic regions that appear independent of the conserved genomic regions identified in other skink species. More broadly, the development of sex markers for the Egernia group opens up a range of potential research questions related to the role that sex plays in the mediation of social behaviour and, through this, the emergence and stability of social life.
Reimagining Europe and its (dis)integration
Authors: Zappettini Franco , Bennett Samuel
Published: February 2022

In this article we introduce our special issue of the Journal of Language & Politics on the
(de)legitimisation of Europe. We start by outlining the rationale and research that led us to the special issue. In Section 2 we set out the contextual framing of the contributions, i.e., the crisis of
legitimacy that European institutions and indeed the entire European project, have faced for the last decade and a half; crises
that have been brought about by different events and actors and have resulted in centrifugal and centripetal processes. Next, we
outline our theoretical approach to legitimation, which combines politico-sociological perspectives with discursive and
communicative ones. This is followed by Section 4, which introduces and weaves together the
contributions to the special issue. Finally, in Section 5 we briefly discuss the findings
with regard to the aims and goals of the issue and also suggest potential next research steps.
Quelques notes à propos de l’olivier dans la chanson de geste
Authors: Guariglia Federico
Published: February 2022

Abstraite

L’olivier est toujours un élément silencieux de la chanson de geste au Moyen Âge. La France septentrionale a précocement développé, aux XII-XIII siècles, une littérature épique qui se focalise sur les héros de la cour de Charlemagne. Les paladins du roi sont toujours engagés dans la lutte contre les infidèles, soit les Sarrasins soit les vassaux rebelles. Outre le courage et la force, ces guerres requièrent diplomatie et stratégie. Par conséquent, avant les conflits, le roi rassemble ses héros sous un olivier pour organiser la guerre. L’olivier devient un objet de bon augure pour la bataille, chargé de symbolisme religieux, en rappelant les prières de Jésus Christ dans le jardin de Gethsémani, la nuit de la Dernière Cène. Dans l’article, on essayera d’écrire une histoire du rôle de l’olivier dans la chanson de geste, en essayant de préciser les différents rôles de l’arbre.
The development of auditory temporal processing during the first year of life
Authors: Cabrera Laurianne , Lau Bonnie K.
Published: February 2022

Objectives:

The processing of auditory temporal information is important for the extraction of voice pitch, linguistic information, as well as the overall temporal structure of speech. However, many aspects of its early development remain poorly understood. This paper reviews the development of auditory temporal processing during the first year of life when infants are acquiring their native language.

Methods:

First, potential mechanisms of neural immaturity are discussed in the context of neurophysiological studies. Next, what is known about infant auditory capabilities is considered with a focus on psychophysical studies involving non-speech stimuli to investigate the perception of temporal fine structure and envelope cues. Finally, this review concludes with studies involving speech stimuli, including those that present vocoded signals as a method of degrading the spectro-temporal information available to infant listeners.

Results/Conclusion:

This synthesis of past research suggests that infants are able to resolve auditory temporal information in the first postnatal months, but the ability to use and process the temporal information in an efficient way along the entire auditory pathway takes longer to mature. These findings have important implications for the development of language abilities, especially for infants who use cochlear implants.
The cylinder amplitude in the hard dimer model on 2D causal dynamical triangulations
Authors: Wheater John F , Xavier P D
Published: February 2022

We consider the model of hard dimers coupled to two-dimensional causal dynamical triangulations (CDT) with all dimer types present and solve it exactly subject to a single restriction. Depending on the dimer weights there are, in addition to the usual gravity phase of CDT, two tri-critical and two dense dimer phases. We establish the properties of these phases, computing their cylinder and disk amplitudes, and their scaling limits.
Study of circular geodesics and shadow of rotating charged black hole surrounded by perfect fluid dark matter immersed in plasma
Authors: Das Anish , Saha Ashis , Gangopadhyay Sunandan
Published: February 2022

In this work, we consider a rotating charged black hole surrounded by perfect fluid dark matter. We consider the system to be immersed in non-magnetised, pressureless plasma. First, we evaluate the null geodesics in order to study the co-rotating and counter rotating photon orbits. Further, we analyse the null geodesics to calculate the celestial coordinates (α, β). The celestial coordinates are used to determine the black hole shadow radius (R
s). Thereafter, we observe and analyse the effects of black hole spacetime, perfect fluid dark matter and plasma parameters (a, Q, χ, k) on the black hole shadow in detail. Finally, we study the effect of plasma distribution on the effective potential (V
eff) of the black hole spacetime as encountered by the photons. We also present bounds on the plasma parameter from the observational data from M87* central supermassive black hole.
Charge density in non-homogeneous media
Authors: Agnesi Antonio
Published: February 2022

Expressions for charge density in non-homogeneous dielectric and ohmic conductors are very simple to derive, but are generally omitted even in relatively sophisticated textbooks. A deceptive situation for which basic laws seem to be violated in an ohmic conductor is highlighted.
A-axis oriented Zn0.72Mg0.28O epitaxial thin films with large second-order nonlinear susceptibility
Authors: Meng Lei , Lv Zunren , Chai Hongyu , Yang Xiaoguang , Yang Tao
Published: February 2022

Large nonlinear susceptibility that originates from strong electronic polarization enables ultrafast nonlinear optical devices. This work discovers that Mg incorporation has important contribution for enhancing second-order nonlinear susceptibility (χ
(2)) and laser-induced surface-damage threshold of wurtzite ZnO epitaxial thin films deposited by radio-frequency magnetron sputtering method. Second-harmonic generation measurements derive that as-deposited Zn0.72Mg0.28O shows a gain of 48%, 77% and 33% in χ
33, χ
31 and χ
15 with respect to as-deposited ZnO. Specially, the annealed Zn0.72Mg0.28O has a χ
33 value of −57.0 ± 1.8 pm V−1, which gets comparable to that of LiNbO3 crystals. Triple-axis x-ray diffraction measurements conclude that the Mg incorporation should increase the χ
(2) under optical frequency electric field by strengthening electronic polarization rather than increasing the residual strain in the film. Furthermore, the annealed Zn0.72Mg0.28O exhibits an increase of 48% in laser-induced surface-damage threshold relative to [11–20] ZnO crystals. These findings open the way of the Zn0.72Mg0.28O thin films to ultrafast nonlinear optical devices.
Thermo-elastic behavior of hexagonal Sc–Ti–Zr–Hf high-entropy alloys
Authors: Huang Shuo , Cheng Jie , Liu Lei , Li Wei , Jin Hongyun , Vitos Levente
Published: February 2022

Recent advances in tuning the long-standing strength-ductility tradeoff have drawn attention to high-entropy alloys (HEAs), and the appearance of hexagonal close-packed (hcp) structures has been emphasized. However, few studies have explored the elastic moduli of hcp HEAs, which is of prime importance for improved understanding of the outstanding mechanical properties. In this work, we focus on a set of equiatomic rare-earth-free HEAs with hcp structures, i.e. ScTiZr, ScTiHf, ScZrHf, TiZrHf, and ScTiZrHf, and their thermo-elastic properties are studied using quantum mechanical first-principles methods. It is found that, for all considered HEAs, the hexagonal axial ratio shows a weak dependence on the temperature effect, and the thermal expansion coefficient remains almost unchanged above room temperature. From the calculated temperature-dependent single-crystal elastic constants, we analyzed the mechanical stability, elastic anisotropy, and derived polycrystalline moduli. Results indicate that the present HEAs exhibit rather high elastic isotropy and large elastic softening resistance. The ab initio predicted Young’s modulus, shear modulus, and specific modulus do not obey the rule of mixture, which indicates that there exists a strong intrinsic hardening effect in all of the considered HEAs. The calculated results are in good agreement with the available experimental measurements.
Spectrally pure far-UVC emission from AlGaN-based LEDs with dielectric band pass filters
Authors: Guttmann Martin , Lobo-Ploch Neysha , Gundlach Heiko , Mehnke Frank , Sulmoni Luca , Wernicke Tim , Cho Hyun Kyong , Hilbrich Katrin , Külberg Alexander , Friedler Matthias , Filler Thomas , Käpplinger Indira , Mitrenga Dennis , Maier Christian , Brodersen Olaf , Ortlepp Thomas , Woggon Ulrike , Einfeldt Sven , Kneissl Michael
Published: February 2022

AlGaN-based far ultraviolet-C (UVC) light emitting diodes (LEDs) with a peak emission wavelength below 240 nm typically show a long-wavelength tail at >240 nm that is detrimental to the use of the devices for skin-friendly antisepsis. We present the development of far-UVC LEDs with reduced long-wavelength emission using a HfO2/SiO2-based distributed Bragg reflector (DBR) filter. When the DBR filter is directly mounted on an LED package, the long-wavelength emission around 250 nm is reduced by two orders of magnitude while the transmitted output power is reduced down to 18%–27% of the initial value for DBR filters with cut-off wavelengths at 237–243 nm. As the transmission through the DBR filter depends strongly on the angle of incidence of the radiation, the transmitted output power of the spectrally pure far-UVC radiation can be doubled when an additional collimating lens is used on top of the LED package before passing through the filter.