bluuebunny/crossref_metadata_2025 huggingface dataset:
Myokardinfarkt bei jungem Seminompatient während Chemotherapie mit Cisplatin, Etoposid und Bleomycin (PEB-Schema)
Authors: Brinkmann Mathias , Tallone Ezequiel Marcelo , Würschmidt Florian , Wülfing Christian , Dieckmann Klaus-Peter
Published: November 2021

Einleitung Die Keimzelltumoren des Hodens können durch Chemotherapie mit Cisplatin, Etoposid und Bleomycin (PEB) in weit über 90 % aller Fälle geheilt werden. Die Chemotherapie wird von den zumeist jungen Männern ohne schwerwiegende Komplikationen toleriert. Kardiovaskuläre Komplikationen sind äußerst selten, sind aber in den letzten Jahren zunehmend in den Fokus geraten.

Fallbericht Ein 33-jähriger Mann mit testikulärem Seminom im klinischen Stadium 2b wurde einer PEB-Chemotherapie unterzogen. Am Ende des ersten Zyklus dieser Therapie ereignete sich ein akuter ST-Hebungs-Infarkt (STEMI). Die Koronarangiografie zeigte eine umschriebene Stenose im proximalen Ramus circumflexus der linken Koronararterie mit einer Dissektion und thrombotischer Auflagerung bei sonst unauffälligem Gefäßstatus. Die Stenose konnte durch Stenteinlage versorgt werden. Die Seminomtherapie wurde fortgesetzt durch Strahlentherapie mit 30 Gy. Es wurde eine komplette Remission erreicht. 6 Monate später ist der Patient herzgesund und rezidivfrei.

Kommentar Bei etwa 0,3 % aller Chemotherapien bei Hodentumorpatienten treten schwerwiegende kardiovaskuläre Komplikationen auf. Als Ursache wird ein direkter Endothelschaden durch Cisplatin mit konsekutiver thrombotischer Auflagerung vermutet. Aufgrund fehlender Komorbidität ist die Prognose dieser Komplikationen zumeist günstig. Die behandelnden Personen sollen von dieser seltenen Komplikationsmöglichkeit wissen, damit im gegebenen Fall eine unverzügliche Diagnostik und Therapie eingeleitet werden kann.
Gastrale MALT-Lymphome
– von pathogenetischen Erkenntnissen zu konsequenter Deeskalation der Therapie
Authors: Fischbach Wolfgang
Published: November 2021

Das gastrale MALT (mucosa-associated-lymphoid-tissue) -Lymphom ist das häufigste gastrointestinale Lymphom. Über Jahrzehnte hinweg galten zunächst die Operation und später Bestrahlung und Chemotherapie als etablierte Therapiestandards. Vor etwa 30 Jahren wurde die pathogenetische Bedeutung der Helicobacter-pylori-Infektion für die Entstehung des gastralen MALT-Lymphoms deutlich. In den folgenden Jahren wurden die pathogenetischen Erkenntnisse konsequent in die klinische Medizin umgesetzt. Dies hat zu einer radikalen Änderung der Therapie dieser Lymphome geführt. Heute ist international die Helicobacter-pylori-Eradikation als Therapie der ersten Wahl anerkannt. Sie führt in den meisten Fällen zu einer Lymphomregression. Die Langzeitprognose der Patienten nach alleiniger Eradikationsbehandlung ist exzellent, selbst dann, wenn endoskopische und/oder histologische Residuen bestehen bleiben und eine „Watch-and-wait“-Strategie gewählt wird.

Die pathogenetischen Erkenntnisse und ihre klinische Anwendung haben zu einer konsequenten Therapiedeeskalation bei den gastralen MALT-Lymphomen geführt. Die vorliegende Übersicht zeigt die einzelnen Schritte dieser Entwicklung und gibt eine Empfehlung zum aktuellen Management von Patienten mit gastralen MALT-Lymphomen.
Current epidemiological trends and in-hospital mortality of acute pancreatitis in Germany: a systematic analysis of standardized hospital discharge data between 2008 and 2017
Authors: Loosen Sven H. , Essing Tobias , Jördens Markus , Koch Alexander , Tacke Frank , Knoefel Wolfram T. , Bode Johannes , Roderburg Christoph , Luedde Tom
Published: November 2021

Background Acute pancreatitis (AP) represents a common gastrointestinal disorder. Complicated disease courses in particular still represent a major clinical challenge and are associated with high mortality. Evaluation of existing data sets and their careful interpretation can support a rational discussion to optimize outcomes of this common gastrointestinal disease.

Methods We used standardized hospital discharge data provided by the Federal Statistical Office of Germany to evaluate hospital mortality and current developments of AP in Germany between 2008 and 2017.

Results In this analysis, 516,618 hospitalized AP cases were included. Main disease etiologies featured biliary (29.9%) and alcoholic (22.7%) AP. The annual frequency of AP increased from 48,858 (2008) to 52,611 (2017), mainly due to a rising incidence of biliary AP. Average hospital mortality was 2.85% and significantly improved over time. While uncomplicated AP had low hospital mortality (1.38%), the presence of organ complications was associated with a mortality of 12.34%. The necessity of mechanical ventilation dramatically increased hospital mortality to 44.06%. Hospital mortality was significantly higher in female patients (3.31%) than males (2.55%) and showed a stepwise increase with patient age. We further identified type 2 diabetes mellitus and obesity as factors associated with increased hospital mortality. Hospital mortality was lowest among patients treated at departments specializing in gastroenterology. Finally, high case volume centers (defined as >98 annual AP cases) had the lowest hospital mortality for patients with complicated courses of AP.

Conclusion With over 50,000 annual hospitalization cases, AP is one of the most important inpatient treatment indications in gastroenterology in Germany. Overall, AP mortality has improved in recent years, presumably due to improved interdisciplinary treatment concepts. In this study, we identified important clinical and epidemiological risk factors for an unfavorable course, which could help to improve risk prediction and triaging, and thus the management of AP.
A Chiral, Dendralenic C–H Acid
Authors: List Benjamin , Höfler Denis
Published: November 2021

We report the synthesis of a chiral dendralenic C–H acid, which contains three unsubstituted binaphthyl moieties. This motif and an achiral variant can be made from their corresponding bis(sulfone) precursors in one step. Despite the presence of the enantiopure binaphthyl backbone, the newly designed chiral C–H acid showed only poor enantioselectivity in a Mukaiyama aldol reaction. First attempts toward the synthesis of 3,3′-hexasubstituted binaphthyl-based dendralenic acids are also reported.
A Retrospective Clinicoradiologic Study of 126 Cerebellopontine Angle Tumors to Predict the Outcome of House–Brackmann Status to Prognosticate Them: A Single-Center Tertiary Care Perspective
Authors: Dhar Sambuddha , Sahu Anurag , Pal Barnava , Singh Kulwant
Published: November 2021

Introduction House–Brackmann (HB) grading had been described to quantify the facial nerve involvement in cerebellopontine angle (CPA) tumors, a very common tumor in neurosurgical practice. Very few studies have specifically looked into the factors predicting the facial nerve morbidity and its severity. Here, we try finding these while going through the clinicoradiologic factors and its natural course to help us prognosticate the patients.

Objective To analyze the size of tumor and duration of symptoms to predict the severity of HB status of facial nerve presentation and outcome, and to study the course of the disease to help prognosticate the patients with respect to facial nerve status.

Materials and Methods This was a retrospective analysis of 126 operated CPA tumors, where we studied the natural course of HB status with respect to size and duration of symptoms of patients at our institute between December 2016 to February 2020.

Results Average duration of symptoms were 33.8 days with increasing risk of HB outcome after 36 days of symptoms. All patients improved to their preoperative facial nerve status at 3 months and only 18 maintained the worsened HB status. Average size of tumor was 3.53 cm, and size higher than 3.8 cm was associated with poorer HB outcome.

Conclusion Although there can be a significant deterioration of HB status in immediate postoperative period, it improves to preoperative status in due time. Tumor larger than 3.8 cm and symptom duration more than 36 days are two important factors predicting poorer HB outcome.
Analysis of Factors Influencing the Long-term Outcome in Primary Spinal Cord Tumors: Review of Literature
Authors: Srinivasan Uddanapalli , Raghunathan Natarajan
Published: November 2021

Introduction Primary spinal cord tumors are amenable to total surgical excision but the outcomes are still diverse.

Objective The purpose of this study is to identify the significant factors which influence the long-term outcome of spinal cord tumors.

Materials and Methods A total of 84 consecutive spinal cord tumor patients who underwent microsurgical excision during April 2003 to 2014 were retrospectively studied. Patients operated after April 2014 were not considered. Ten factors were taken and correlated with the outcome. Multiple regression analysis was used. Patients were periodically evaluated at 1, 6 months, 1, 2, and 5 years. In 72 cases, postoperative MRI scans were performed. The follow-up period ranged between 5 to 15 years.

Results In our study, we had 64 extramedullary tumors and 21 intramedullary tumors with varied pathology. Axial location of the tumour (20.294/0.000), extent of the resection of the tumour (13.827/0.001), preoperative Nurick grade (11.349/0.023), and location of the tumour in the spine with respect to vertebral segments (8.151/0.017) were significant predictive factors. We had good outcomes in 65 cases and poor outcomes in 19 cases.

Conclusion Our results show location of the tumor with respect to axial plane and vertebral segments were the main contributing factors. They influence the extent of excision of the spinal cord tumor. Preoperative neurological status is the fourth factor which independently determines the long-term outcome. It is one of the few papers where patients have been followed-up for a long period ranging from 5 to 15 years.
Application of the International Society on Thrombosis and Haemostasis Scoring System in Evaluation of Disseminated Intravascular Coagulation in Patients with Acute Leukemias
Authors: Aggarwal Aditi , Mahajan Deepti , Sharma Poonam
Published: November 2021

Background Coagulation abnormalities are common in acute leukemia (AL) and disseminated intravascular coagulation (DIC) frequently complicates the onset of AL.

Aim To determine the prevalence of overt DIC in AL using the International Society on Thrombosis and Haemostasis (ISTH) scoring system.

Materials and Methods This prospective observational study was performed on 57 newly diagnosed or relapsed cases of AL. Detailed clinical history and coagulation profile of the patients were evaluated. Diagnosis of overt and nonovert DIC was established using the ISTH scoring system and results tabulated.

Observations A total of 57 patients with AL participated in the study, including 31 (54.39%) patients with acute lymphoblastic leukemia (ALL) and 26 (45.61%) with acute myeloid leukemia (AML). In total, 18 of 57 patients (31.58%) with AL fulfilled the criteria of overt DIC according to the ISTH scoring system, including 10 (32.25%) patients with ALL and 8 (30.76%) patients with AML. The highest prevalence of DIC was seen in the M3 subtype among AML and the L1 subtype among ALL, respectively. The mean ISTH score in patients of overt DIC in ALL and AML patients was 5.1 and 5, respectively. Abnormalities in platelet count and D-dimer levels were the most useful parameters in diagnosing overt DIC and the difference between overt DIC and nonovert DIC groups was highly significant.

Conclusions Overt DIC was observed in approximately one-third of patients with AL. Prevalence of overt DIC was found to be comparable in patients with ALL and AML. Mean platelet count and D-dimer levels were the most useful parameters in detecting overt DIC.
Highlighting Differences in Cancer Epidemiology in India: A Descriptive Report from a Private Sector Hospital-Based Cancer Registry in Delhi for the Years 2013 to 2017
Authors: Shrivastav Gunjan , Adhana Arun , Kumari Kamlesh , Khan Naseem , Kumar Ankit , Rathore Shailender , Anand Anil Kumar , Arora Ramandeep Singh
Published: November 2021

Introduction Cancer continues to grow in number. Knowing the epidemiology helps in prevention and treatment. Existing hospital-based cancer registries (HBCRs) provide little data of private sector including patients for medical tourism.

Objectives The aim of this study was to describe the distribution of cancer at a tertiary center in the private sector in North India for all cancer patients.

Materials and Methods Cases were ascertained from the Oncology Outpatient Department of Max Super Specialty Hospital, Saket, between January 1, 2013, and December 31, 2017, and from pathology database since July 2015. They were abstracted into National Cancer Registry Program (NCRP) core pro forma. We conducted a descriptive analysis of distribution by age, gender, nationality, site, stage, and treatment.

Results Among the 15,850 confirmed cases, 8,034 (51%) were males. Nearly 1.8% of patients were pediatric (<15 years) and 30.1% geriatric (>65 years). A high proportion of patients (13%) came from outside India and 27% from outside Delhi-National Capital Region. The most common cancers in males were prostate (10.9%), lung (10%), and mouth (7.6%). Stomach was the most common site of cancer in international male patients. Four of the top ten cancers in males were of the gastrointestinal tract (esophagus, stomach, colon, and rectum). The most common cancers in females were breast (37.4%), ovary (7.1%), and corpus uteri (5.6%). Tobacco-related cancers accounted for 36.9% of cancers in males and 11.3% in females. The composite stage in males was IV in 54%, followed by stage III (21%), stage II (15%), and stage I (10%). In females, stage IV was 33%, stage III was 23%, stage II was 28%, and stage I was 16%. As registry included outpatient record visits and pathology records, not all registered patients received treatment at Max Super Specialty Hospital. Overall, 49.8% of male patients and 49.7% of female patients received treatment at Max Super Specialty Hospital. Data quality metrics matched other national HBCRs.

Conclusion We highlight the differences from other NCRP HBCRs, with prostate cancer being the top cancer in males and gastrointestinal cancers forming major proportion among all. Socioeconomic status of our patients, referral bias, and international medical tourism could be responsible.
Polymethylmethacrylate Incorporating Nanodiamonds for Denture Repair: In Vitro Study on the Mechanical Properties
Authors: Gad Mohammed M. , Ali Mohamed Saber , Al-Thobity Ahmad M. , Al-Dulaijan Yousif A. , Zayat Mai El , Emam Abdel-Naser M. , Akhtar Sultan , Khan Soban Q. , Al-Harbi Fahad A. , Fouda Shaimaa M.
Published: November 2021

Objective This study aimed to evaluate the effect of nanodiamond (ND) addition to repair resin with repair gap modifications on the flexural and impact strength of repaired polymethylmethacrylate denture base.

Materials and Methods Heat-polymerized acrylic resin specimens (N = 100/test) were prepared and sectioned to half creating two repair gaps: 2.5- and 0 mm with 45 degrees beveling. They were further divided into subgroups (n = 20) according to ND concentration (control, 0.25%ND, and 0.50%ND), thermocycling (500 cycles) was done to half the specimens in each subgroup. Flexural strength was tested using 3-point bending test and impact strength was tested by Charpy's impact test. Analysis of variance and post-hoc Tukey's tests were performed for data analysis (α = 0.05). Scanning electron microscope was employed for fracture surface analysis and ND distribution.

Results Before and after thermocycling, the addition of ND significantly increased the flexural strength and elastic modulus in comparison to control group (p ˂ 0.001), while 0 mm repair gap showed insignificant difference between ND-reinforced groups (p ˃ 0.05). Regarding impact strength, ND addition increased the impact strength with 0 mm gap in comparison to control and 2.5 mm with ND (p˂0.001), while later groups showed no significant in between (p ˃ 0.05). Comparing thermocycling effect per respective concentration and repair gap, thermocycling adversely affected all tested properties except elastic modulus with 0 mm–0.25 and 0 mm–0.5% and impact strength with 2.5 mm, 2.5 mm–0.25%, 2.5 mm– 0.5% (p ˃ 0.05).

Conclusion ND addition combined with decreased repair gap improved the flexural strength, elastic modulus, and impact strength of repaired denture resin, while thermocycling has a negative effect on denture repair strength.
Physicochemical Properties of Zinc and Lactose in Solid Mixtures: Influence of Trituration Process
Authors: Fontes Clarissa , Oliveira Adriana P. , Batista João V.C. , Martins Cleo , Rossi André , Yapuchura Enrique R. , Furtado Priscila , Meireles Paloma , Capella Marcia Alves Marques , Picciani Paulo H.S. , Holandino Carla
Published: November 2021

Background Recent experimental results supporting the dynamization process show modification in the characteristics of solid mixtures.

Objective The present work aims to evaluate the physicochemical properties of metallic zinc and lactose, evidencing the interactions between all chemical components presented in dynamized solid mixtures by analytical techniques.

Methods Mixtures of zinc and lactose (1:9 w/w) were successively triturated at the same proportion according to the Brazilian Homeopathic Pharmacopoeia, receiving the designation of 10−1 – 10−6 (1dH – 6dH). All samples were submitted to the following characterization techniques: Atomic Absorption Spectrometry (AAS), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Thermogravimetry (TG), and Raman Spectroscopy (RS).

Results AAS results detected 97.0% of zinc in the raw material, and the triturated zinc lactose system (ZnMet) presented mean values similar to those expected for the physical mixtures: i.e., 9.94%, 1.23%, and 0.11% in the three first proportions (10−1, 10−2, 10−3), respectively. SEM images showed particle size reduction due to the trituration process. The XRD assays of ZnMet 10−3 and 10−6 indicated peak changes at 12.3° and 43.26°, probably associated with modifications of inter-atomic crystalline spacing. The thermal analysis results of dynamized samples suggest modifications in the chemical interaction between zinc and lactose induced by the physical forces applied. RS experiments showed variation in vibration frequencies due to the dynamization procedure, in which marked ZnMet 10−6 spectral modifications were detected at 357, 477, 1086 and 1142 cm−1, and in the wavelength range 860–920 cm−1.

Conclusion These results highlight the importance of applying suitable characterization methods to improve our understanding of the properties of homeopathic solid mixtures, whereas the uses of sensitive tools evidence the influence of trituration on the crystalline properties and in the enthalpy variation of dynamized samples.
Development of a Perioperative Medication-Related Clinical Decision Support Tool to Prevent Medication Errors: An Analysis of User Feedback
Authors: Nanji Karen C. , Garabedian Pamela M. , Shaikh Sofia D. , Langlieb Marin E. , Boxwala Aziz , Gordon William J. , Bates David W.
Published: November 2021

Objectives Medication use in the perioperative setting presents many patient safety challenges that may be improved with electronic clinical decision support (CDS). The objective of this paper is to describe the development and analysis of user feedback for a robust, real-time medication-related CDS application designed to provide patient-specific dosing information and alerts to warn of medication errors in the operating room (OR).

Methods We designed a novel perioperative medication-related CDS application in four phases: (1) identification of need, (2) alert algorithm development, (3) system design, and (4) user interface design. We conducted group and individual design feedback sessions with front-line clinician leaders and subject matter experts to gather feedback about user requirements for alert content and system usability. Participants were clinicians who provide anesthesia (attending anesthesiologists, nurse anesthetists, and house staff), OR pharmacists, and nurses.

Results We performed two group and eight individual design feedback sessions, with a total of 35 participants. We identified 20 feedback themes, corresponding to 19 system changes. Key requirements for user acceptance were: Use hard stops only when necessary; provide as much information as feasible about the rationale behind alerts and patient/clinical context; and allow users to edit fields such as units, time, and baseline values (e.g., baseline blood pressure).

Conclusion We incorporated user-centered design principles to build a perioperative medication-related CDS application that uses real-time patient data to provide patient-specific dosing information and alerts. Emphasis on early user involvement to elicit user requirements, workflow considerations, and preferences during application development can result in time and money efficiencies and a safer and more usable system.
Validation of a Newly Developed Competency Assessment Tool for the Posterior Sagittal Anorectoplasty
Authors: Joosten Maja , Bökkerink Guus M.J. , Sutcliffe Jonathan , Levitt Marc A. , Diefenbach Karen , Reck Carlos A. , Krois Wilfried , Blaauw Ivo de , Botden Sanne M.B.I.
Published: November 2021

Introduction The correction of an anorectal malformation (ARM) is complex and relatively infrequent. Simulation training and subsequent assessment may result in better clinical outcomes. Assessment can be done using a competency assessment tool (CAT). This study aims to develop and validate a CAT for the posterior sagittal anorectoplasty (PSARP) on a simulation model.

Materials and Methods The CAT-PSARP was developed after consultation with experts in the field. The PSARP was divided into five steps, while tissue and instrument handling were scored separately. Participants of pediatric colorectal hands-on courses in 2019 and 2020 were asked to participate. They performed one PSARP procedure on an ARM simulation model, while being assessed by two objective observers using the CAT-PSARP.

Results A total of 82 participants were enrolled. A fair interobserver agreement was found for general skills (intraclass correlation coefficient [ICC] = 0.524, p < 0.001), a good agreement for specific skills (ICC = 0.646, p < 0.001), and overall performance (ICC = 0.669, p < 0.001). The experienced group scored higher on all steps (p < 0.001), except for “anoplasty (p = 0.540),” compared with an inexperienced group.

Conclusion The CAT-PSARP is a suitable objective assessment tool for the overall performance of the included steps of the PSARP for repair of an ARM on a simulation model.
Retinal Nerve Fibre Layer Analysis in Non-Glaucomatous Pseudoexfoliation Syndrome Patients
Authors: Khateeb Erum Waris , Lone Imtiyaz Ahmad , Qazi Ifrah Ahmad
Published: November 2021

Background Pseudoexfoliation syndrome (PXS) is a disorder characterized by the progressive accumulation of fibrillary extracellular deposits in several ocular tissues. It is an independent risk factor for glaucomatous optic nerve damage. Retinal nerve fiber layer (RNFL) thickness analysis using optical coherence tomography is a documented investigative tool to detect glaucoma at an early stage.

Objective The aim was to evaluate and compare RNFL thickness in PXS patients without glaucoma with their age- and sex-matched healthy controls and detect the possibility of early glaucomatous damage in patients with RNFL thinning.

Study Design This was a cross sectional case–control study.

Materials and Methods A total of 100 patients were included, of which 50 were cases (Group A) and 50 were controls (Group B). RNFL thickness of cases and controls were compared using Zeiss Cirrus HD-OCT 500 (ZEISS Medical Technology, United States).

Results There were no significant differences between the two groups with respect to mean RFNL thickness in nasal (p = 0.129) and temporal quadrants (p = 0.832). The mean inferior RNFL thickness values were 112.9 ± 21.72 μm in Group A and 120.6 ± 10.35 μm in Group B (p = 0.002). The mean thickness of the retinal nerve fiber layer in superior quadrant in Group A was 101.6 ± 23.16 μm, whereas it was 113.5 ± 13.47 μm in group B (p < 0.001). The average RFNL thickness in Group A was 85.1 ± 13.99 μm and it was 88.9 ± 7.01 μm in Group B (p = 0.017).

Conclusion There was statistically significant difference in RNFL thickness between cases and controls in inferior and superior quadrants and in global average thickness.
European Pediatric Surgeons' Association Survey on the Management of Primary Spontaneous Pneumothorax in Children
Authors: Soyer Tutku , Dariel Anne , Dingemann Jens , Martinez Leopoldo , Pini-Prato Alessio , Morini Francesco , De Coppi Paolo , Gorter Ramon , Doi Takashi , Antunovic Sanja Sindjic , Kakar Mohit , Hall Nigel J.
Published: November 2021

Aim To evaluate the practice patterns of the European Pediatric Surgeons' Association (EUPSA) members regarding the management of primary spontaneous pneumothorax (PSP) in children.

Methods An online survey was distributed to all members of EUPSA.

Results In total, 131 members from 44 countries participated in the survey. Interventional approach (78%) is the most common choice of treatment in the first episode, and most commonly, chest tube insertion (71%) is performed. In the case of a respiratory stable patient, 60% of the responders insert chest tubes if the pneumothorax is more than 2 cm. While 49% of surgeons prefer surgical intervention in the second episode, 42% still prefer chest tube insertion. Main indications for surgical treatment were the presence of bullae more than 2 cm (77%), and recurrent pneumothorax (76%). Eighty-four percent of surgeons prefer thoracoscopy and perform excision of bullae with safe margins (91%). To prevent recurrences, 54% of surgeons perform surgical pleurodesis with pleural abrasion (55%) and partial pleurectomy (22%). The responders who perform thoracoscopy use more surgical pleurodesis and prefer shorter chest tube duration than the surgeons performing open surgery (p < 0.05).

Conclusion Most of the responders prefer chest tube insertion in the management of first episode of PSP and perform surgical treatment in the second episode in case of underlying bullae more than 2 cm and recurrent pneumothorax. The surgeons performing thoracoscopy use more surgical pleurodesis and prefer shorter chest tube duration than the responders performing open surgery. The development of evidence-based guidelines may help standardize care and improve outcomes in children with PSP.
Effect of focusing plane on laser blow-off shock waves from confined aluminum and copper foils
Authors: Guthikonda Nagaraju , Sai Shiva S , Manikanta Elle , Kameswari D P S L , Ikkurthi V R , Sijoy C D , Prem Kiran P
Published: November 2021

We present results on the dynamics of laser-induced blow-off shockwave generation from the rear side of 20 µm thick aluminum and copper foil confined with a glass (BK7) substrate. These foils are irradiated by 10 ns, 532 nm laser pulses of energy 25–200 mJ corresponding to the intensity range 0.2–10 GW cm−2. The plasma temperature at the glass-foil interface is observed to play an important role in the coupling of laser energy to the foil. From our experiments and 1D hydrodynamic simulations, we confirm that moving the glass-foil interface away from the focal plane led to (a) enhanced absorption of the laser beam by the foil resulting in ∼30% higher blow-off shock velocities (b) significant changes in the material ejection in terms of increased blow-off mass of the foil (c) lower plasma density and temperatures. The material ejection as well as blow-off shock velocity is higher for Al compared to Cu. The simulated shock evolution in ambient air shows a reasonably good agreement with the experimental results.
Adversarial domain adaptation of asymmetric mapping with CORAL alignment for intelligent fault diagnosis
Authors: Li Ranran , Li Shunming , Xu Kun , Li Xianglian , Lu Jiantao , Zeng Mengjie , Li Miaozhen , Du Jun
Published: November 2021

Rolling bearings play a vital role in the overall operation of rotating machinery. In practice, many learning methods for variable-speed fault diagnosis ignore task-specific decision boundaries, making it very difficult to completely match feature distribution between different domains. Therefore, to overcome this problem, an adversarial domain adaptation of asymmetric mapping with CORAL alignment is presented. The asymmetric mapping feature extractor is able to extract more specific-domain features with obvious distinction. Meanwhile, combining the maximum classifier discrepancy of deep transfer to give an adversarial approach and taking the task-specific decision boundaries into account, class-level alignment between the features of the source domain and target domain can be attempted. To prevent degenerate learning, which is possibly caused by asymmetric mapping and adversarial learning, the model is constrained by deep CORAL alignment to extract more domain-invariant features. Experimental results show that the proposed method can solve the variable-speed (a small span of intermediate vehicle speeds) fault diagnosis problem well, with high transfer accuracy and strong generalization.
Multi-scale modeling of 2D GaSe FETs with strained channels
Authors: Toral-Lopez A , Santos H , Marin E G , Ruiz F G , Palacios J J , Godoy A
Published: November 2021

Electronic devices based on bidimensional materials (2DMs) are the subject of an intense experimental research, that demands a tantamount theoretical activity. The latter must be hold up by a varied set of tools able to rationalize, explain and predict the operation principles of the devices. However, in the broad context of multi-scale computational nanoelectronics, there is currently a lack of simulation tools connecting atomistic descriptions with semi-classical mesoscopic device-level simulations and able to properly explain the performance of many state-of-the-art devices. To contribute to filling this gap we present a multi-scale approach that combines fine-level material calculations with a semi-classical drift-diffusion transport model. Its use is exemplified by assessing 2DM field effect transistors with strained channels, showing excellent capabilities to capture the changes in the crystal structure and their impact into the device performance. Interestingly, we verify the capacity of strain in monolayer GaSe to enhance the conduction of one type of carrier, enabling the possibility to mimic the effect of chemical doping on 2D materials. These results illustrate the great potential of the proposed approach to bridge levels of abstraction rarely connected before and thus contribute to the theoretical modeling of state-of-the-art 2DM-based devices.
Reversible structural transition of two-dimensional copper selenide on Cu(111)
Authors: Zhuang Yuan , Que Yande , Xu Chaoqiang , Liu Bin , Xiao Xudong
Published: November 2021

Structural engineering opens a door to manipulating the structures and thus tuning the properties of two-dimensional materials. Here, we report a reversible structural transition in honeycomb CuSe monolayer on Cu(111) through scanning tunneling microscopy and Auger electron spectroscopy (AES). Direct selenization of Cu(111) gives rise to the formation of honeycomb CuSe monolayers with one-dimensional moiré structures (stripe-CuSe), due to the asymmetric lattice distortions in CuSe induced by the lattice mismatch. Additional deposition of Se combined with post annealing results in the formation of honeycomb CuSe with quasi-ordered arrays of triangular holes (hole-CuSe), namely, the structural transition from stripe-CuSe to hole-CuSe. Further, annealing the hole-CuSe at higher temperature leads to the reverse structural transition, namely from hole-CuSe to stripe-CuSe. AES measurement unravels the Se content change in the reversible structural transition. Therefore, both the Se coverage and annealing temperature play significant roles in the reversible structural transition in CuSe on Cu(111). Our work provides insights in understanding of the structural transitions in two-dimensional materials.
High-pressure vapor-solid transformation of 2D template to derive 2D Co–N–C electrocatalysts for oxygen reduction reaction
Authors: Lin Li , Du Xing , Wang Junjie , Chen Hui , He Xuan , Fang Wei , Li Yang , Chen Zhen , Zhao Lei
Published: November 2021

Two-dimensional (2D) cobalt zeolitic imidazolate frameworks (ZIF-67) have attracted significant research interests to synthesize cobalt and nitrogen co-doped carbon-based (Co–N–C) catalyst for oxygen reduction reaction (ORR). However, most of the current synthetic approaches of 2D ZIF-67 are energy-intensive, environmentally hazardous and low-yield. Herein, a feasible and efficient ‘morphology-retaining method via a high-pressure vapor-solid reaction’ are reported to synthesize 2D ZIF-67 nanosheets by using 2D cobalt carbonate hydroxide template. In the strategy, the high-pressure vapor caused by sublimation of 2-Melm and the pores formed from effusion of CO2 during transformation ensure the complete transformation from 2D template to 2D ZIF-67. The corresponding 2D Co–N–C catalyst exhibits comparable ORR electrocatalytic activity and better stability than Pt/C in alkaline media. The present method is expected to offer a feasible and universal way to efficiently synthesize 2D M–N–C catalysts.
Experimental investigations of a new concept of wave energy converter hybridizing piezoelectric and dielectric elastomer generators
Authors: Boccalero Gregorio , Chesne Simon , Mignot Emmanuel , Riviere Nicolas , Jean-Mistral Claire
Published: November 2021

A novel concept of a surge wave energy converter for nearshore applications is investigated experimentally. The centimetre-sized prototype developed in this work represents a proof of concept of a submerged system, which entails a hybrid transduction solution for the electrical conversion of wave energy, that uses piezoelectric elements (PZEs) and dielectric elastomer generators (DEG). The idea is to exploit the horizontal pressure gradient and horizontal water velocity underneath the waves to compress the PZE and inflate each half wave period a soft variable capacitance, which composes the DEG. The electrical charges created by the PZE are used to polarize the DEG, which is able to multiply the input energy. This hybridization is conceived to allow the system to generate electrical energy from waves without conventional high voltage supplies, thus reducing production costs and allowing standalone clean electrical generation. The article provides the preliminary fluid-mechanical measurements performed in a wave flume with a first version of the prototype and supported by a model comprising the fluid/structure interaction, the materials response, and the electrical operations. An estimation of the output energy of a small-sized prototype in constant charge mode is computed, and perspectives for optimizing the system are presented.
Optical tunable multifunctional slow light device based on double monolayer graphene grating-like metamaterial
Authors: Xu Hui , Wang Xiaojing , Chen Zhiquan , Li Xuelei , He Longhui , Dong Yulan , Nie Guozheng , He Zhihui
Published: November 2021

A very simple optical tunable device, which can realize multiple functions of frequency selection, reflection and slow light, is presented at the investigation. The proposed device is constructed by a periodic grating-like structure. There are two dielectrics (graphene and silicon) in a period of the equivalent grating. The incident light will strongly resonate with the graphene of electrostatic doping, forming an evanescent wave propagating along the surface of graphene, and this phenomenon is the surface plasmon. Under constructive interference of the polaritons, a unique plasmonic induced transparency phenomenon will be achieved. The induced transparency produced by this device can be well theoretically fitted by the bright and dark mode of optical equivalent cavity which can be called coupled mode theory. This theory can well analyze the influence of various modes and various losses between the function of this device. The device can use gate voltages for electrostatic doping in order to change the graphene carrier concentration and tune the optical performance of the device. Moreover, the length of the device in y-direction is will be much larger than the length of single cycle, providing some basis for realizing the fast tunable function and laying a foundation for the integration. Through a simulation and calculation, we can find that the group index and group delay of this device are as high as 515 and 0.257 picoseconds (ps) respectively, so it can provide a good construction idea for the slow light device. The proposed grating-like metamaterial structure can provide certain simulation and theoretical help for the optical tunable reflectors, absorbers, and slow light devices.
Amplitude resonance response and feedback control of cantilever beams with tip-mass under aerodynamic load
Authors: Rolphe Zemtchou Francis , Sandrine Mabekou Takam Jeanne , Nganyo Nguenang Pernel , Kisito Talla Pierre
Published: November 2021

The dynamic of a cantilever beam with tip mass is studied under an aerodynamic loading. The effects of coupling is investigated by tacking into account the fluid flow. Using the multiple time scale method, the approximative solutions are found and the study of their stability is made by the Routh-Hurwitz stability criterion. The influence of parameters on the system is studied at the harmonic and subharmonic resonances. The results show that, the effects of tip mass can be neglected in harmonic resonance case, while they are more important in subharmonic resonance cases. The results equally demonstrate that an increase of the stable state fluid velocity reduces the amplitude of vibrations. In addition, the hysteresis phenomenon studies show that it is principally induced by nonlinearity coefficients. Finally, time-delay feedback control is applied and the effects of controlling are observed on amplitude response curve at the harmonic resonance, from where we note that optimized choice of control parameters can be useful in controlling vibrations.
Determination of methanol concentration in ethanol in liquid phase by a phononic crystal Mach-Zehnder interferometer
Authors: Salman Aysevil , Ates Emine , Biçer Ahmet , Deniz Sualp , Cicek Ahmet , Korozlu Nurettin
Published: November 2021

A practical and portable ultrasonic interferometric sensor to detect methanol concentration in ethanol in the liquid phase is numerically investigated. For high-sensitivity operation, the sensor is designed as a Mach–Zehnder interferometer based on a linear-defect waveguide in a two-dimensional phononic crystal, which consists of square array of cylindrical steel rods in water. The waveguide core comprises polyethylene tubing, impedance-matched with water, filled with either pure ethanol or ethanol-methanol binary mixture, allowing fast replacement of the analyte. Band structure analyses through the finite-element method are carried out to obtain guiding modes at frequencies around 200 kHz. With 50 × 21 cells with 4.2 mm periodicity, the total sensor area is 210-by-88.2 millimeters, which can be significantly reduced by increasing the operating frequency to megahertz range. The interferometer is constructed via T junctions of the waveguide, which facilitates low-loss equal splitting and recollection of ultrasonic waves. Sample and reference wave paths are constructed by filling polyethylene tubing on the upper and lower halves of the interferometer with the ethanol-methanol mixture and pure ethanol, respectively. Frequency-domain finite-element method simulations reveal that the sensor output is characterized by several transmission peaks, one of which is centered at 203.35 kHz with a full-width at half-maximum of 20 Hz, resulting in a quality factor of 10167. The peak frequency of this peak redshifts at a rate of 7.24 Hz per percent volume fraction change in methanol. The peak shift is linear when the methanol volume fraction is below 10%. Besides, the interferometric sensor has a figure of merit around 0.35. The proposed ultrasonic sensor offers rapid detection of methanol content in ethanol with high sensitivity.
Scattering in the Poincaré disk and in the Poincaré upper half-plane
Authors: de Jesus Anderson L , Maioli Alan C , Schmidt Alexandre G M
Published: November 2021

We investigate the scattering of a plane wave in the hyperbolic plane. We formulate the problem in terms of the Lippmann-Schwinger equation and solve it exactly for barriers modeled as Dirac delta functions running along: (i) N − horizontal lines in the Poincaré upper half-plane; (ii) N − concentric circles centered at the origin; and, (iii) a hypercircle in the Poincaré disk.
Lossless, scalable implicit likelihood inference for cosmological fields
Authors: Makinen T. Lucas , Charnock Tom , Alsing Justin , Wandelt Benjamin D.
Published: November 2021

We present a comparison of simulation-based inference to full, field-based analytical inference in cosmological data analysis. To do so, we explore parameter inference for two cases where the information content is calculable analytically: Gaussian random fields whose covariance depends on parameters through the power spectrum; and correlated lognormal fields with cosmological power spectra. We compare two inference techniques: i) explicit field-level inference using the known likelihood and ii) implicit likelihood inference with maximally informative summary statistics compressed via Information Maximising Neural Networks (IMNNs). We find that a) summaries obtained from convolutional neural network compression do not lose information and therefore saturate the known field information content, both for the Gaussian covariance and the lognormal cases, b) simulation-based inference using these maximally informative nonlinear summaries recovers nearly losslessly the exact posteriors of field-level inference, bypassing the need to evaluate expensive likelihoods or invert covariance matrices, and c) even for this simple example, implicit, simulation-based likelihood incurs a much smaller computational cost than inference with an explicit likelihood. This work uses a new IMNN implementation in Jax that can take advantage of fully-differentiable simulation and inference pipeline. We also demonstrate that a single retraining of the IMNN summaries effectively achieves the theoretically maximal information, enhancing the robustness to the choice of fiducial model where the IMNN is trained.
Towards testing the theory of gravity with DESI: summary statistics, model predictions and future simulation requirements
Authors: Alam Shadab , Arnold Christian , Aviles Alejandro , Bean Rachel , Cai Yan-Chuan , Cautun Marius , Cervantes-Cota Jorge L. , Cuesta-Lazaro Carolina , Devi N. Chandrachani , Eggemeier Alexander , Fromenteau Sebastien , Gonzalez-Morales Alma X. , Halenka Vitali , He Jian-hua , Hellwing Wojciech A. , Hernández-Aguayo César , Ishak Mustapha , Koyama Kazuya , Li Baojiu , de la Macorra Axel , Meneses Rizo Jennifer , Miller Christopher , Mueller Eva-Maria , Niz Gustavo , Ntelis Pierros , Rodríguez Otero Matia , Sabiu Cristiano G. , Slepian Zachary , Stark Alejo , Valenzuela Octavio , Valogiannis Georgios , Vargas-Magaña Mariana , Winther Hans A. , Zarrouk Pauline , Zhao Gong-Bo , Zheng Yi
Published: November 2021

Shortly after its discovery, General Relativity (GR) was applied to predict the behavior of our Universe on the largest scales, and later became the foundation of modern cosmology. Its validity has been verified on a range of scales and environments from the Solar system to merging black holes. However, experimental confirmations of GR on cosmological scales have so far lacked the accuracy one would hope for — its applications on those scales being largely based on extrapolation and its validity there sometimes questioned in the shadow of the discovery of the unexpected cosmic acceleration. Future astronomical instruments surveying the distribution and evolution of galaxies over substantial portions of the observable Universe, such as the Dark Energy Spectroscopic Instrument (DESI), will be able to measure the fingerprints of gravity and their statistical power will allow strong constraints on alternatives to GR.

In this paper, based on a set of N-body simulations and mock galaxy catalogs, we study the predictions of a number of traditional and novel
summary statistics beyond linear redshift distortions in two well-studied modified gravity models — chameleon f(R) gravity and a braneworld model — and the potential of testing these deviations from GR using DESI. These
summary statistics employ a wide array of statistical properties of the galaxy and the underlying dark matter field, including two-point and higher-order statistics, environmental dependence, redshift space distortions and weak lensing. We find that they hold promising power for testing GR to unprecedented precision. The major future challenge is to make realistic, simulation-based mock galaxy catalogs for both GR and alternative models to fully exploit the statistic power of the DESI survey (by matching the volumes and galaxy number densities of the mocks to those in the real survey) and to better understand the impact of key systematic effects. Using these, we identify future simulation and analysis needs for gravity tests using DESI.
CNNs for enhanced background discrimination in DSNB searches in large-scale water-Gd detectors
Authors: Maksimović D. , Nieslony M. , Wurm M.
Published: November 2021

Gadolinium-loading of large water Cherenkov detectors is a prime method for the detection of the Diffuse Supernova Neutrino Background (DSNB). While the enhanced neutron tagging capability greatly reduces single-event backgrounds, correlated events mimicking the IBD coincidence signature remain a potentially harmful background. Neutral-Current (NC) interactions of atmospheric neutrinos potentially dominate the DSNB signal especially in the low-energy range of the observation window that reaches from about 12 to 30 MeV.

The present paper investigates a novel method for the discrimination of this background. Convolutional Neural Networks (CNNs) offer the possibility for a direct analysis and classification of the PMT hit patterns of the prompt events. Based on the events generated in a simplified SuperKamiokande-like detector setup, we find that a trained CNN can maintain a signal efficiency of 96% while reducing the residual NC background to 2% of the original rate. Comparing to recent predictions of the DSNB signal and measurements of the NC background levels in Super-Kamiokande, the corresponding signal-to-background ratio is about 4:1, providing excellent conditions for a DSNB discovery.