bluuebunny/crossref_metadata_2025 huggingface dataset:
Letaler Verlauf einer fulminanten nekrotisierenden Fasziitis und Clostridium-perfringens-Infektion nach Resektion eines Weichteil-Sarkoms
Authors: Sogorski Alexander , Bernstorff Maria , Lehnhardt Marcus , Behr Björn , Wagner Johannes Maximilian
Published: April 2022

Vorgestellt wird der Fall eines 57-jährigen Patienten mit letalem Verlauf nach Resektion eines Myxofibrosarkoms am Oberschenkel. Auf dem Boden einer nekrotisierenden Fasziitis bei Mischinfektion von Staphylococcus lugdunensis und Clostridium perfringens mit Ausbildung ausgedehnter Myonekrosen kam es zu einem septischen Schock mit Hämolyse und Multiorganversagen. Die Autoren zeichnen den fulminanten Verlauf dieser sehr seltenen Komplikation nach onkologischer Resektion nach und diskutieren das chirurgische Vorgehen anhand aktueller Literatur.
Einflussfaktoren auf die veränderte Lebensqualität nach postbariatrischer Abdominoplastik
Authors: Bienert Johanna Dorothea Charlotte Wanda , Bertolini Julia , Bertolini Roland , Drücke Daniel B. H.
Published: April 2022

Einleitung Die Verbesserung der gesundheitsbezogenen Lebensqualität (HRQoL) durch postbariatrische Straffungsoperationen und deren Effekte auf die Gewichtsstabilität im Langzeitverlauf gelten als gesichert. Welche Einflussfaktoren dabei eine Rolle spielen, wurde im Rahmen dieser Studie untersucht.

Patienten, Materialien und Methoden Für die Datenanalyse wurde die HRQoL vor und nach der Abdominoplastik mittels des „36-Item Short-Form Health Survey“-Fragebogens erhoben. Zusätzlich wurde die Häufigkeit des Auftretens von Meteorismusbeschwerden erfasst und überprüft, ob dieses Auftreten in Zusammenhang mit einer simultan zur Abdominoplastik durchgeführten Rectusscheidenplikation steht. Einschlusskriterium war eine Adipositas ≥ I° vor der Gewichtsabnahme. Ausschlusskriterien waren eine postoperative Neumanifestation einer schwerwiegenden, von der Abdominoplastik unabhängigen Erkrankung sowie eine Schwangerschaft im Beobachtungszeitraum. Die Ergebnisse wurden mit der deutschen Normpopulation (Norm) verglichen.

Resultate Für die körperliche Summenskala (KSK) ergab sich eine signifikant bessere postoperative HRQoL (präOP: 40,19 ± 12,27; postOP: 47,72 ± 9,89; p < 0,001). Präoperativ lagen die KSK und die PSK (psychische Summenskala) statistisch signifikant unterhalb des Wertes der Norm (KSK: p < 0,001; PSK: p < 0,01). Postoperativ ergaben sich keine signifikanten Unterschiede (KSK: p = 0,051; PSK: p = 0,118). Patienten mit einer zusätzlichen Rectusscheidenplikation (n = 9) litten signifikant häufiger unter Meteorismusbeschwerden > 4/Woche als Patienten ohne diesen Operationsschritt (n = 21) (p < 0,05). Im Vergleich der Patienten mit einer Meteorismussymptomatik < 4/W gegenüber > 4/W hatten erstere eine signifikant bessere Vitalität (< 4/W: 61,09 ± 24,95; > 4/W: 34,29 ± 21,49; p < 0,05) und einen besseren allgemeinen Gesundheitszustand (< 4/W: 68,04 ± 23,23; > 4/W: 44,71 ± 27,8; p < 0,05). Patienten mit einer Meteorismussymptomatik > 4/W hatten gegenüber der Norm eine schlechtere Vitalität (p < 0,05).

Schlussfolgerung Die Analyse der erhobenen Studiendaten lässt den Schluss zu, dass bei ehemals adipösen Patienten nicht nur von einer postoperativen Verbesserung der HRQoL ausgegangen werden kann, sondern auch von einer postoperativen Angleichung dieser an die Norm. Ferner führt eine zusätzlich zur Abdominoplastik ausgeführte Rectusscheidenplikation häufiger zu einer die HRQoL verschlechternden Meteorismussymptomatik. Das Vorliegen einer depressiven Störung ist ein guter Prädiktor für ein schlechteres HRQoL-Outcome.
Fadenmaterial in der Phlebologie
Authors: Witt Antonia , Bruning Guido , Woitalla-Bruning Jasmin
Published: April 2022

Es gibt unterschiedliche Herangehensweisen für den Einsatz von Nahtmaterialien in der Phlebologie. Sie werden in Abhängigkeit von der jeweiligen Schule und vom vorhandenen Fadensortiment im Haus bestimmt. Allerdings bestehen leitlinienbezogene Empfehlungen, z.B. dass der Faden zum Abbinden der Vena saphena magna bzw. der Vena saphena parva mittels nicht resorbierbaren Fadens zur Rezidivprophylaxe empfohlen werden kann 1.

Der optimale Faden, der alle Vorteile vereint, existiert nicht. Es gilt daher, individuelle Entscheidungen zur Fadenwahl zu treffen und dabei insbesondere die durch das Gewebe an einen Faden gestellten Anforderungen zu berücksichtigen.

Mit diesem Artikel wollen wir den Lesern die Eigenschaften verschiedener Fäden näherbringen, die Entscheidung für bestimmte Nahtmaterialien in der operativen Phlebologie erklären und durch Bilder veranschaulichen.
Real-world prevalence of endoscopic findings in patients with gastroesophageal reflux symptoms: a cross-sectional study
Authors: Weissman Simcha , Chris-Olaiya Abimbola , Weber Andrew T. , Mehta Tej I. , Doherty Bryan , Nambudiri Vinod , Atoot Adam , Aziz Muhammad , Tabibian James H.
Published: April 2022

Background and study aims Data regarding endoscopic findings and symptom correlation in patients with gastroesophageal reflux disease (GERD) symptoms are largely limited to single-center experiences. We performed a nationwide study to examine the association between patient-reported GERD symptoms and clinically relevant endoscopic findings.

Patients and methods Using the National Endoscopic Database, we retrospectively identified all esophagogastroduodenoscopies (EGDs) performed for GERD symptoms from 2000 to 2014. Patients were categorized into three symptom groups: 1) typical reflux only (R); 2) airway only (A); and 3) both R and A (R + A). Outcomes were the point prevalence of endoscopic findings in relation to patient-reported GERD symptom groups. Statistical analyses were performed using R.

Results A total of 167,459 EGDs were included: 96.8 % for R symptoms, 1.4 % for A symptoms, and 1.8 % for R + A symptoms. Of the patients, 13.4 % had reflux esophagitis (RE), 9.0 % Barrett’s esophagus (BE), and 45.4 % hiatal hernia (HH). The R + A group had a significantly higher point prevalence of RE (21.6 % vs. 13.3 % and 12 %; P < 0.005) and HH (56.9 % vs. 45.3 % and 38.3 %; P < 0.005) compared to the R or A groups, respectively. The R group had a significantly higher point prevalence of BE compared to the A or R + A groups, respectively (9.1 % vs. 6.1 % and 6.1 %, P < 0.005).

Conclusions On a national level, patients experiencing R + A GERD symptoms appear more likely to have RE and HH, while those with only R symptoms appear more likely to have BE. These real-world data may help guide how providers and institutions approach acid-suppression therapy, set thresholds for recommending EGD, and develop management algorithms.
Nicht-suizidales selbstverletzendes Verhalten – Einblicke in ein wenig bekanntes plastisch-chirurgisches Patient*innenkollektiv
Authors: Köllensperger Eva , Walter Clara , Germann Günter , Engel Holger , Reichenberger Matthias
Published: April 2022

Hintergrund und Fragestellung Nicht-suizidales selbstverletzendes Verhalten (NSSV) ist trotz einer hohen Prävalenz bei Jugendlichen und jungen Erwachsenen ein außerhalb der Psychiatrie nur wenig bekanntes Krankheitsbild. Auch aus diesem Unwissen heraus erfahren Betroffene von medizinischem Fachpersonal oft Unverständnis für ihr Handeln, Ablehnung und Diskriminierung. Dies behindert einen dauerhaften Abschluss mit dem selbstverletzenden Verhalten und den Aufbau einer von Vertrauen geprägten Arzt-Patienten-Beziehung und kann zu einer erneuten Traumatisierung der Betroffenen führen. Wir möchten mit dieser Arbeit interessierte plastisch-chirurgischen Kolleg*innen anhand unseres Patient*innenkollektivs über das Krankheitsbild des NSSV informieren und damit eine Hilfestellung für den Umgang mit betroffenen Patient*innen geben.

Patienten und Methoden Von 600 Patient*innen mit Narben aus NSSV aus unserer plastisch-chirurgischen Narbenspezialsprechstunde der letzten 5 Jahren wurden die erhobenen Daten bei Erstvorstellung ausgewertet und mit der aktuellen Literatur verglichen.

Ergebnisse 95 % der Patient*innen waren weiblich, 5 % männlich. Im Mittel waren 8,4 Jahre zwischen letzter Selbstverletzung und Erstvorstellung in unserer Sprechstunde vergangen, die Patient*innen waren bei Erstvorstellung im Mittel 26 Jahre alt. Am häufigsten war durch NSSV-Narben der linke Unterarm (48 %) betroffen, gefolgt von beiden Unterarmen (40 %), dem linken Oberarm (20 %), beiden Oberarmen (15 %) und beiden Oberschenkeln (14 %). Bei 57 % der Patient*innen war dabei nur eine Körperregion betroffen. Die von NSSV-Narben insgesamt betroffene Körperoberfläche betrug im Mittel 380 cm2 mit hohen Schwankungen. Häufige Nebendiagnosen waren Schilddrüsenfehlfunktionen und Depressionen. 21 % der Patient*innen befanden sich zum Zeitpunkt der Erstvorstellung in psychiatrischer, psychologischer oder psychotherapeutischer Behandlung.

Schlussfolgerung Unsere hier gezeigten Daten geben Einblick in ein großes Kollektiv von Patient*innen mit Narben aus NSSV, die sich zur Korrektur derselben in unserer plastisch-chirurgischen Spezialsprechstunde vorstellten. Die Patient*innen waren meist weiblich, die Narben am häufigsten an den Unterarmen lokalisiert und das letzte NSSV im Mittel mehr als 8 Jahre vergangen. Unsere Daten sollen einen faktenbasierten Zugang zu einer Gruppe von Patient*innen ermöglichen, mit einem in chirurgischen Disziplinen wenig bekannten Krankheitsbild, das aufgrund seiner hohen Prävalenz und lebenslangen Folgen stärker in den Fokus gerückt werden sollte.
Endoscopic submucosal dissection for colorectal dysplasia in inflammatory bowel disease: a US multicenter study
Authors: Ngamruengphong Saowanee , Aihara Hiroyuki , Friedland Shai , Nishimura Makoto , Faleck David , Benias Petros , Yang Dennis , Draganov Peter V. , Kumta Nikhil A. , Borman Zachary A. , Dixon Rebekah E. , Marion James F. , DʼSouza Lionel S. , Tomizawa Yutaka , Jit Simran , Mohapatra Sonmoon , Charabaty Aline , Parian Alyssa , Lazarev Mark , Figueroa Esteban J. , Hanada Yuri , Wang Andrew Y. , Wong Kee Song Louis M.
Published: April 2022

Background and study aims In patients with inflammatory bowel disease (IBD), endoscopically visible lesions with distinct borders can be considered for endoscopic resection. The role of endoscopic submucosal dissection (ESD) for these lesions is not well defined because of a paucity of data. We aimed to evaluate the outcomes of colorectal ESD of dysplastic lesions in patients with IBD across centers in the United States.

Patients and methods This was a retrospective analysis of consecutive patients with IBD who were referred for ESD of dysplastic colorectal lesions at nine centers. The primary endpoints were the rates of en bloc resection and complete (R0) resection. The secondary endpoints were the rates of adverse events and lesion recurrence.

Results A total of 45 dysplastic lesions (median size 30mm, interquartile range [IQR] 23 to 42 mm) in 41 patients were included. Submucosal fibrosis was observed in 73 %. En bloc resection was achieved in 43 of 45 lesions (96 %) and R0 resection in 34 of 45 lesions (76 %). Intraprocedural perforation occurred in one patient (2.4 %) and was treated successfully with clip placement. Delayed bleeding occurred in four patients (9.8 %). No severe intraprocedural bleeding or delayed perforation occurred. During a median follow-up of 18 months (IQR 13 to 37 months), local recurrence occurred in one case (2.6 %). Metachronous lesions were identified in 11 patients (31 %).

Conclusions ESD, when performed by experts, is safe and effective for large, dysplastic colorectal lesions in patients with IBD. Despite the high prevalence of submucosal fibrosis, en bloc resection was achieved in nearly all patients with IBD undergoing ESD. Careful endoscopic surveillance is necessary to monitor for local recurrence and metachronous lesions after ESD.
Predictors of adverse events and early mortality after esophageal stent placement in a low resource setting: a series of 3823 patients in Kenya
Authors: Mwachiro Michael , Parker Robert , Lando Justus , Simel Ian , Chol Nyail , Ranketi Sinkeet , Chepkwony Robert , Pyego Linus , Chepkirui Caren , Chepkemoi Winnie , Fleischer David , Dawsey Sanford , Topazian Mark , Burgert Steve , White Russell
Published: April 2022

Background and study aims Dysphagia from esophageal cancer may be palliated with self-expanding metallic stents (SEMS). Controversy exists about the use of dilation before SEMS deployment.

Patients and methods We performed a retrospective cohort study of patients who had SEMS placement without fluoroscopy for palliation at Tenwek Hospital in Bomet, Kenya between January 1999 and April 2019. The primary outcome was any serious adverse event (AE) (chest pain, stent migration, perforation, bleeding, or all-cause mortality) within 30 days of the procedure. Various demographic and clinical characteristics, and procedural details, were examined as risk factors. Technical success, defined as correct SEMS placement, and clinical success, defined as dysphagia score improvement without 30-day mortality, were examined.

Results A total of 3823 patients underwent SEMS placement, with 2844 (74.4 %) placed in the second decade of the study. Technical and clinical success were achieved in 97.2 % and 95.5 %, respectively, with mean dysphagia scores improving from 3.4 (SD 0.6) to 0.9 (SD 1.3) post-stent placement. AEs occurred in 169 patients (4.4 %). AEs, specifically perforations, were associated with dilation to greater than 36F in the first decade. Perforation rates decreased from the first (4.1 %) to the second decade (0.2 %). Only 30% had complete 30-day follow-up data.

Conclusions SEMS placement is a safe, effective method of palliating malignant dysphagia, with low rates of AEs and 30-day mortality and high rates of clinical and technical success. Dilation can facilitate placement of SEMS without fluoroscopy but should not be performed above 36F due to the risk of perforation.
Immune-Related Adverse Events (irAEs) in Cancer, with Inputs from a Nursing Expert: A Review
Authors: Buch Sajad Ahmad , Baba Mudasir Rashid
Published: April 2022

Immune checkpoint inhibitors (ICPis) belong to a group of immunotherapeutic agents that act on different immune cells and tumor cells and reactivate the suppressed immune system of the host. The emergence of immunotherapy has resulted in the successful management of many malignancies. High success rates with certain advanced cancers have attributed wide importance and relevance to the use of immunotherapy. Although ICPis have gained huge popularity, their use often leads to side effects that can affect almost any system; immune-related adverse events (irAEs). These adverse events occur due to unrestrained T cell activity that unsettles the immune homeostasis of the host. Although close monitoring for toxicities controls the events on most of the occasions, the inability to diagnose them early may prove fatal on some occasions due to their subtle and nonspecific symptoms. This review summarizes in brief the usual irAEs and their management, besides a very important nursing perspective, from a nursing expert about an overall insight into the routine irAEs.
DFT-based QM/MM with particle-mesh Ewald for direct, long-range electrostatic embedding
Authors: Pederson John P. , McDaniel Jesse G.
Published: April 2022

We present a density functional theory (DFT)-based, quantum mechanics/molecular mechanics (QM/MM) implementation with long-range electrostatic embedding achieved by direct real-space integration of the particle-mesh Ewald (PME) computed electrostatic potential. The key transformation is the interpolation of the electrostatic potential from the PME grid to the DFT quadrature grid from which integrals are easily evaluated utilizing standard DFT machinery. We provide benchmarks of the numerical accuracy with choice of grid size and real-space corrections and demonstrate that good convergence is achieved while introducing nominal computational overhead. Furthermore, the approach requires only small modification to existing software packages as is demonstrated with our implementation in the OpenMM and Psi4 software. After presenting convergence benchmarks, we evaluate the importance of long-range electrostatic embedding in three solute/solvent systems modeled with QM/MM. Water and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM/BF4) ionic liquid were considered as “simple” and “complex” solvents, respectively, with water and p-phenylenediamine (PPD) solute molecules treated at the QM level of theory. While electrostatic embedding with standard real-space truncation may introduce negligible errors for simple systems such as water solute in water solvent, errors become more significant when QM/MM is applied to complex solvents such as ionic liquids. An extreme example is the electrostatic embedding energy for oxidized PPD in BMIM/BF4 for which real-space truncation produces severe errors even at 2–3 nm cutoff distances. This latter example illustrates that utilization of QM/MM to compute redox potentials within concentrated electrolytes/ionic media requires carefully chosen long-range electrostatic embedding algorithms with our presented algorithm providing a general and robust approach.
Propulsion of bullet- and cup-shaped nano- and microparticles by traveling ultrasound waves
Authors: Voß Johannes , Wittkowski Raphael
Published: April 2022

Propulsion of colloidal particles via planar traveling ultrasound waves has attracted increasing attention in recent years. A frequently studied type of particle is bullet-shaped and cup-shaped nano- and microparticles. Based on acoustofluidic simulations, this article investigates how the propulsion of bullet-shaped particles depends on their length and diameter, where cup-shaped particles are included as limiting cases corresponding to the smallest particle length. The structure of the flow field generated by the particles is discussed and it is shown that the particles' propulsion strength increases with their length and diameter. When varying the diameter, we also observed a sign change of the propulsion. This work complements previous experimental studies that have addressed such particles only for particular aspect ratios, and the provided understanding of how the propulsion of the particles depends on their dimensions will prospectively be helpful for the choice of particle shapes that are most suitable for future experimental studies.
Intramolecular hydrogen bonding analysis
Authors: Harville Taylor , Gordon Mark S.
Published: April 2022

The quasi-atomic orbital (QUAO) bonding analysis is used to study intramolecular hydrogen bonding (IMHB) in salicylic acid and an intermediate that is crucial to the synthesis of aspirin. The bonding analysis rigorously explores IMHB through directly accessing information that is intrinsic to the molecular wave function, thereby bypassing the need for intrinsically biased methods. The variables that affect the strength of IMHB are determined using kinetic bond orders, QUAO populations, and QUAO hybridizations. Important properties include both the interatomic distance between hydrogen and oxygen participating in the IMHB and the hybridization on the oxygen. The bonding analysis further shows that each intramolecular hydrogen bond is a four-electron three-center bond. The bonding analysis is used to understand how aromatic reactivity changes due to the effect of functional groups on the aromatic ring.
Hardy-Littlewood-Sobolev inequality for $p=1$
Authors: Stolyarov Dmitriy Mikhailovich
Published: April 2022

Let $\mathcal{W}$ be a closed dilation and translation invariant subspace of the space of $\mathbb{R}^\ell$-valued Schwartz distributions in $d$ variables. We show that if the space $\mathcal{W}$ does not contain distributions of the type $a\otimes \delta_0$, $\delta_0$ being the Dirac delta, then the inequality $\|\operatorname{I}_\alpha [f]\|_{L_{d/(d-\alpha),1}}\lesssim \|f\|_{L_1}$ holds true for functions $f\in\mathcal{W}\cap L_1$ with a uniform constant; here $\operatorname{I}_\alpha$ is the Riesz potential of order $\alpha$ and $L_{p,1}$ is the Lorentz space. As particular cases, this result implies the inequality $\|\nabla^{m-1} f\|_{L_{d/(d-1),1}} \lesssim \|A f\|_{L_1}$, where $A$ is a cancelling elliptic differential operator of order $m$, and the inequality $\|\operatorname{I}_\alpha f\|_{L_{d/(d-\alpha),1}} \lesssim \|f\|_{L_1}$, where $f$ is a divergence free vector field.
Bibliography: 59 titles.
Canonical geometrization of orientable $3$-manifolds defined by vector colourings of $3$-polytopes
Authors: Erokhovets Nikolai Yur'evich
Published: April 2022

The geometrization conjecture of Thurston (finally proved by Perelman) says that any oriented $3$-manifold can canonically be partitioned into pieces, which have a geometric structure modelled on one of the eight geometries: $S^3$, $\mathbb R^3$, $\mathbb H^3$, $S^2\times\mathbb R$, $\mathbb H^2\times \mathbb R$, the universal cover of $\mathrm{SL}(2,\mathbb{R})$, $\mathrm{Nil}$ and $\mathrm{Sol}$. In a seminal paper (1991) Davis and Januszkiewicz introduced a wide class of $n$-dimensional manifolds, small covers over simple $n$-polytopes. We give a complete answer to the following problem: build an explicit canonical decomposition of any orientable $3$-manifold defined by a vector colouring of a simple $3$-polytope, in particular, of a small cover. The proof is based on an analysis of results in this direction obtained previously by different authors.
Bibliography: 44 titles.
Vaccine technologies used to develop COVID-19 vaccines
Authors: Selleck Paul , Macreadie Ian
Published: April 2022

In December 2019, cases of atypical pneumonia were diagnosed in hospital patients in Wuhan, Hubei province, China. The disease, now known as COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As case numbers increased and spread across the planet many companies scrambled to develop vaccines to control the infection and disease. Prior research on SARS-CoV-1, new vaccine technologies and unprecedented funding have allowed vaccines to be developed and approved in record time, without the usual pauses and bypassing any of the requirements of the vaccine approval process. This paper is a review of the current literature on some of the vaccines targeting SARS-CoV-2 and of the new technologies used to produce them.
Raman response and shear viscosity in the non-Fermi liquid phase of Luttinger semimetals
Authors: Mandal Ipsita , Freire Hermann
Published: April 2022

Luttinger semimetals represent materials with strong spin–orbit coupling, harboring doubly-degenerate quadratic band touchings at the Brillouin zone center. In the presence of Coulomb interactions, such a system exhibits a non-Fermi liquid phase [dubbed as the Luttinger–Abrikosov–Beneslavskii (LAB) phase], at low temperatures and zero doping. However, a clear experimental evidence of this emergent state remains elusive to this date. Hence, we focus on extracting the Raman response as a complementary experimental signature. At frequencies much larger than the temperature, the Raman response exhibits a power-law behavior, which can be verified experimentally. On the other hand, at lower frequencies, the Raman response displays a quasi-elastic peak. We also compute the ratio of the shear viscosity and the entropy density, and the value obtained is a consequence of the hyperscaling violation that emerges in the LAB phase.
Robust non-integer conductance in disordered 2D Dirac semimetals
Authors: Amanatidis Ilias , Kleftogiannis Ioannis
Published: April 2022

We study the conductance G of 2D Dirac semimetal nanowires at the presence of disorder. For an even nanowire length L determined by the number of unit cells, we find non-integer values for G that are independent of L and persist with weak disorder, indicated by the vanishing fluctuations of G. The effect is created by a combination of the scattering effects at the contacts (interface) between the leads and the nanowire, an energy gap present in the nanowire for even L and the topological properties of the 2D Dirac semimetals. Unlike conventional materials the reduced G due to the scattering at the interface, is stabilized at non-integer values inside the nanowire, leading to a topological phase for weak disorder. For strong disorder the system leaves the topological phase and the fluctuations of G are increased as the system undergoes a transition/crossover toward the Anderson localized (insulating) phase, via a non-standard disordered phase. We study the scaling and the statistics of G at these phases. In addition we have found that the effect of robust non-integer G disappears for odd L, which results in integer G, determined by the number of open channels in the nanowire, due to resonant scattering.
Three-dimensional control of layer by layer thin films via laser modification
Authors: Leake Kaelyn , Martinez Jose , Stensland Alexander , Yochum Hank
Published: April 2022

A novel modification to the traditional layer by layer process that adds three-dimensional control to the technique is introduced. In this modification to the process, the substrate is irradiated with laser light during the polycation and/or polyanion dipping cycles. An array of PAH/PCBS polymer thin films were fabricated using the laser modified approach with varied bilayer numbers, laser powers, and laser irradiation times. The modification was conducted with a semiconductor laser with powers from 1.1 to 5.5 W at 450 nm. Surface profilometry results show a change in height of more than 500 nm for a 55 bilayer PAH/PCBS thin film. For 25 bilayer films, the addition of laser modification during the PAH cycle leads to a reduction in absorbance of up to 54% compared to the areas not being irradiated. The absorbance at 365 nm associated with PCBS shows a nonlinear relationship with bilayer number, in contrast to the usual linear relationship between absorbance and bilayer without laser irradiation. By adjusting irradiation time, irradiation power, number of bilayers, and the location of irradiation, a variety of structures with controlled thicknesses can be fabricated.
Towards a safe and efficient clinical implementation of machine learning in radiation oncology by exploring model interpretability, explainability and data-model dependency
Authors: Barragán-Montero Ana , Bibal Adrien , Dastarac Margerie Huet , Draguet Camille , Valdés Gilmer , Nguyen Dan , Willems Siri , Vandewinckele Liesbeth , Holmström Mats , Löfman Fredrik , Souris Kevin , Sterpin Edmond , Lee John A
Published: April 2022

The interest in machine learning (ML) has grown tremendously in recent years, partly due to the performance leap that occurred with new techniques of deep learning, convolutional neural networks for images, increased computational power, and wider availability of large datasets. Most fields of medicine follow that popular trend and, notably, radiation oncology is one of those that are at the forefront, with already a long tradition in using digital images and fully computerized workflows. ML models are driven by data, and in contrast with many statistical or physical models, they can be very large and complex, with countless generic parameters. This inevitably raises two questions, namely, the tight dependence between the models and the datasets that feed them, and the interpretability of the models, which scales with its complexity. Any problems in the data used to train the model will be later reflected in their performance. This, together with the low interpretability of ML models, makes their implementation into the clinical workflow particularly difficult. Building tools for risk assessment and quality assurance of ML models must involve then two main points: interpretability and data-model dependency. After a joint introduction of both radiation oncology and ML, this paper reviews the main risks and current solutions when applying the latter to workflows in the former. Risks associated with data and models, as well as their interaction, are detailed. Next, the core concepts of interpretability, explainability, and data-model dependency are formally defined and illustrated with examples. Afterwards, a broad discussion goes through key applications of ML in workflows of radiation oncology as well as vendors’ perspectives for the clinical implementation of ML.
Strain engineering in optoelectronic properties of MoSi2N4 monolayer: ultrahigh tunability
Authors: Alavi-Rad Hosein
Published: April 2022

Controllable optical properties are important for optoelectronic applications. Recently, the two-dimensional MoSi2N4 monolayer was successfully synthesized by chemical vapor deposition, showing remarkable stability in the ambient condition. Motivated by this achievement, herein, we investigate the electronic and optical properties of MoSi2N4 monolayer under mechanical strain through the first-principle calculations. The considered monolayer is structurally and dynamically stable. It is a semiconductor with an indirect band gap of 1.92 eV so that the size of the band gap is easily tuned under biaxial strain. By increasing the tensile strain up to 6%, the effective mass of holes increases to 3.84 me whereas the effective mass of electrons reduces to 0.43 me. In other words, under the strain of 6%, one can have strongly localized holes together with free electrons simultaneously in MoSi2N4 monolayer, which could bring fascinating features like ferromagnetism and superconductivity. Under the strain from 10% to 18%, a Mexican hat dispersion is observed in the highest valence band in such a manner that its coefficient increases from 0.28 to 2.89 eVÅ, indicating the potential thermoelectric application of MoSi2N4 monolayer under strain. Under the strain of 8%, the light absorption coefficient is improved by almost 70%. More importantly, this monolayer tolerates biaxial strain up to 18% and stays mechanically and dynamically stable, making it very promising for flexible nanoelectronics. The controllable electronic and optical properties of MoSi2N4 monolayer may open up an important path for exploring next-generation optoelectronic applications.
H
0 tension and uncertainty principles
Authors: Moradpour H , Aghababaei S , Corda C , Sadeghnezhad N
Published: April 2022

Supernova explosion is a phenomenon described very well by the laws of quantum mechanics meaning that the Heisenberg uncertainty principle (HUP) restricts the achievable information from this source, and indeed, the accuracy of measurements on Hubble parameter by using this source is bounded by HUP. On the other hand, cosmic microwave background (CMB) stores quantum gravity (QG) effects dominant in the early universe. Hence, its physics is supposed to be under the influence of the modified forms of HUP (obtained in the QG scenarios). This means that the most accurate H
0 measurements, by using this source, may meet modified forms of HUP instead of HUP itself. Therefore, photons coming from these sources satisfy different uncertainty principles. Here, we show that the difference between these two regimes (or equally, the difference between the uncertainty principles) establishes an eternal discrepancy between the H
0 values obtained by these sources. Consequently, more accurate observations and estimations on the value of Hubble parameter may help us find out the values of QG parameters.
Four-family =1 supersymmetric Pati–Salam models from intersecting D6-branes
Authors: Li Tianjun , Sun Rui , Zhang Chi
Published: April 2022

We investigate the construction of four-family=1supersymmetric Pati–Salam models from Type IIAT6/Z2×Z2orientifold with intersectingD6-branes. Utilizing the deterministic algorithm introduced in He W, Li T and Sun R (2021 arXiv:hep-th/2112.09632), we obtain 274 types of models with three rectangular tori and distinct gauge coupling relations at string scale, while 6 types of models with two rectangular tori and one tilted torus. In both cases, there exists a class of models with gauge coupling unification at string scale. In particular, for the models with two rectangular tori, one tilted torus and gauge coupling unification, the gaugino condensations are allowed, and thus supersymmetry breaking and moduli stabilization are possible for further phenomenological study.
Equal compressibility structural phase transition of molybdenum at high pressure
Authors: Xiong Lun , Li Bin , Miao Fang , Li Qiang , Chen Guangping , Zhu Jinxia , Ding Yingchun , He Duanwei
Published: April 2022

We have studied the high-pressure compression behavior of molybdenum up to 60 GPa by synchrotron radial x-ray diffraction (RXRD) in a diamond anvil cell (DAC). It is found that all diffraction peaks of molybdenum undergo a split at around 27 GPa, and we believe that a phase transition from a body-centered cubic structure to a rhombohedral structure at room pressure has occurred. The slope of pressure–volume curve shows continuity before and after this phase transition, when fitting the pressure–volume curves of the body-centered cubic structure at low pressure and the rhombohedral structure at high pressure. A bulk modulus of 261.3 (2.7) GPa and a first-order derivative of the bulk modulus of 4.15 (0.14) are obtained by using the nonhydrostatic compression data at the angle ψ = 54.7° between the diffracting plane normal and stress axis.
Reciprocal transformations of the space–time shifted nonlocal short pulse equations
Authors: Wang Jing , Wu Hua , Zhang Da-Jun
Published: April 2022

Reciprocal transformations of the space–time shifted nonlocal short pulse equations are elaborated. Covariance of dependent and independent variables involved in the reciprocal transformations is investigated. Exact solutions of the space–time shifted nonlocal short pulse equations are given in terms of double Wronskians. Realness of independent variables involved in the reciprocal transformations is verified. Dynamics of some obtained solutions are illustrated.
Exchange-coupling-induced fourfold magnetic anisotropy in CoFeB/FeRh bilayer grown on SrTiO3(001)
Authors: Shao Qingrong , Meng Jing , Zhu Xiaoyan , Xie Yali , Cheng Wenjuan , Jiang Dongmei , Xu Yang , Shang Tian , Zhan Qingfeng
Published: April 2022

Exchange coupling across the interface between a ferromagnetic (FM) layer and an antiferromagnetic (AFM) or another FM layer may induce a unidirectional magnetic anisotropy and/or a uniaxial magnetic anisotropy, which has been extensively studied due to the important application in magnetic materials and devices. In this work, we observed a fourfold magnetic anisotropy in amorphous CoFeB layer when exchange coupling to an adjacent FeRh layer which is epitaxially grown on an SrTiO3(001) substrate. As the temperature rises from 300 K to 400 K, FeRh film undergoes a phase transition from AFM to FM phase, the induced fourfold magnetic anisotropy in the CoFeB layer switches the orientation from the FeRh〈 110〉 to FeRh〈 100 〉 directions and the strength is obviously reduced. In addition, the effective magnetic damping as well as the two-magnon scattering of the CoFeB/FeRh bilayer also remarkably increase with the occurrence of magnetic phase transition of FeRh. No exchange bias is observed in the bilayer even when FeRh is in the nominal AFM state, which is probably because the residual FM FeRh moments located at the interface can well separate the exchange coupling between the below pinned FeRh moments and the CoFeB moments.
Ignition dynamics of radio frequency discharge in atmospheric pressure cascade glow discharge
Authors: Zhang Ya-Rong , Han Qian-Han , Fang Jun-Lin , Guo Ying , Shi Jian-Jun
Published: April 2022

A cascade glow discharge in atmospheric helium was excited by a microsecond voltage pulse and a pulse-modulated radio frequency (RF) voltage, in which the discharge ignition dynamics of the RF discharge burst was investigated experimentally. The spatio-temporal evolution of the discharge, the ignition time and optical emission intensities of plasma species of the RF discharge burst were investigated under different time intervals between the pulsed voltage and RF voltage in the experiment. The results show that by increasing the time interval between the pulsed discharge and RF discharge burst from 5 μs to 20 μs, the ignition time of the RF discharge burst is increased from 1.6 μs to 2.0 μs, and the discharge spatial profile of RF discharge in the ignition phase changes from a double-hump shape to a bell-shape. The light emission intensity at 706 nm and 777 nm at different time intervals indicates that the RF discharge burst ignition of the depends on the number of residual plasma species generated in the pulsed discharges.
Degradation mechanisms for a-InGaZnO thin-film transistors functioning under simultaneous DC gate and drain biases
Authors: Song Tianyuan , Zhang Dongli , Wang Mingxiang , Shan Qi
Published: April 2022

Degradation of a-InGaZnO thin-film transistors working under simultaneous DC gate and drain bias stress is investigated, and the corresponding degradation mechanism is proposed and verified. The maximum degradation occurs under the bias stress condition that makes the electric field and electron concentration relatively high at the same time. Trapping of hot electrons in the etching-stop layer under the extended drain electrode is proven to be the underlying mechanism. The observed degradation phenomena, including distortion in the transfer curve on a logarithmic scale and two-slope dependence on gate bias on a linear scale, current crowding in the output curve, and smaller degradation in transfer curves measured under large drain bias, can all be well explained with the proposed degradation mechanism.
How graph features decipher the soot assisted pigmental energy transport in leaves? A laser-assisted thermal lens study in nanobiophotonics
Authors: Sankararaman S
Published: April 2022

The paper employs the principles of graph theory in nanobiophotonics, where the soot-assisted intra-pigmental energy transport in leaves is unveiled through the laser-induced thermal lens (TL) technique. Nanofluids with different soot concentrations are sprayed over Lablab purpureus (L) sweet leaves, and the extracted pigments are analyzed. The graph features of the constructed complex network from the TL signal of the samples are analyzed to understand their variations with optical absorbance. Besides revealing the presence of optimum soot concentration that can enhance photosynthesis, the study brings out the potential application of graph features in nanobiophotonics.
Coercivity enhancement of sintered Nd-Fe-B magnets by grain boundary diffusion with Pr80–x
Al
x
Cu20 alloys
Authors: Jin Zhe-Huan , Jin Lei , Ding Guang-Fei , Guo Shuai , Zheng Bo , Fan Si-Ning , Wang Zhi-Xiang , Fan Xiao-Dong , Zhu Jin-Hao , Chen Ren-Jie , Yan A-Ru , Pan Jing , Liu Xin-Cai
Published: April 2022

A grain boundary diffusion (GBD) process with Pr80 – x
Al
x
Cu20 (x = 0, 10, 15, 20) low melting point alloys was applied to commercial 42M sintered Nd–Fe–B magnets. The best coercivity enhancement of a diffused magnet was for the Pr65Al15Cu20 GBD magnet, from 16.38 kOe to 22.38 kOe. Microstructural investigations indicated that increase in the Al content in the diffusion source can form a continuous grain boundary (GB) phase, optimizing the microstructure to enhance the coercivity. The coercivity enhancement is mainly due to the formation of a continuous GB phase to separate the main phase grains. Exchange decoupling between the adjacent main phase grains is enhanced after the GBD process. Meanwhile, the introduction of Al can effectively promote the infiltration of Pr into the magnet, which increases the diffusion rate of rare-earth elements within a certain range. This work provides a feasible method to enhance coercivity and reduce the use of rare-earth resources by partial replacement of rare-earth elements with non-rare-earth elements in the diffusion source.
Probing solvent dependent femtosecond transient coherent oscillations to reveal interfacial dynamics
Authors: Das D K , Makhal K , Goswami Debabrata
Published: April 2022

Probing transient states in molecules having vibronic transitions with femtosecond (fs) laser pulses often results in coherent oscillations either in the ground state, the excited states, or both. We find such coherent oscillations are highly solvent-dependent and provide a holistic overview of the pump-probe experiments for ultrafast dye dynamics at interfaces. For molecules dissolved in single solvents, modulations in oscillations occur due to transitions in the sub-vibrational levels of the electronic state. For binary solvents, in particular, these modulations are strongly sensitive to solvent compositions. The changes induced by various solvent compositions are drastic enough to act as a control parameter for dynamical control processes. We demonstrate an end-to-end understanding of ground-state coherent oscillations, vibrational cooling, ground-state recovery processes, and excited-state dynamics through a series of experiments. We further present a methodology for establishing such control using near-infrared dyes to measure the oscillations with fs pump-probe techniques. In the case of immiscible binary solvents, the same method allows us to investigate the liquid–liquid interface. Our control methodology is validated by an experiment using a cyanine dye dissolved in dimethyl sulfoxide, interfaced with neat diethyl-ether. The dye dynamics are retarded on moving from the bulk dye solution towards the interface with the neat diethyl-ether. When sampled along the direction of the vector pointing from the bulk towards the near interface, monotonically decreasing time constants are obtained. This result strongly suggests the importance of microheterogeneity in interfacial dynamics.
Rotating of metallic microparticles with an optimal radially polarized perfect optical vortex
Authors: Zhou Yuan , Zhang Yanan , Gao Wenyu , Yan Shaohui , Li Manman , Li Xing , Wang Ping , Yao Baoli
Published: April 2022

We report an optical rotating of metallic microparticles using an optimal radially polarized perfect optical vortex (RPPOV). Due to its polarization structure, the RPPOV’s transverse intensity exhibits two rings separated by roughly a wavelength. We show both numerically and experimentally that a metallic microparticle immersed in such a double-ring vortex develops two radial equilibrium positions, at either of which the particle can experience a non-zero azimuthal force, thus leading to a simultaneous rotation of the metallic microparticles about the optical axis at two orbits with different radius. Furthermore, the rotation radius and velocity can be separately controlled by changing the parameters of the RPPOV.
Alms, Arms, And The Aftermath: The Legacies Of Rebel Provision Of Humanitarian Aid In Ethiopia
Authors: Matfess Hilary
Published: April 2022

The 1983–1985 famine in Ethiopia is perhaps one of the most internationally recognized instances of acute human suffering. Although the international community’s response to the crisis and the ways in which the famine reshaped the nature of humanitarian aid have been probed, less often discussed is that one of the most effective relief organizations delivering assistance—the Relief Society of Tigray (REST)—was the humanitarian wing of an insurgency, the Tigrayan People’s Liberation Front (TPLF). This article asserts that the process of responding to the famine amidst a protracted civil war left an indelible mark on the ways in which the TPLF approached domestic civil society and international assistance after war as a part of the governing party, the Ethiopian People’s Revolutionary Democratic Front. This article describes the legacies of the rebels’ wartime humanitarian activities. It asserts that REST’s prominence as an organization, its role as a model and catalyst for other party-affiliated organizations, the government’s suspicion of domestic civil society and efforts to strictly control international assistance, and its reliance on service delivery to bolster its domestic legitimacy are all legacies of the rebels’ wartime governance. In doing so, this article calls for greater attention to the dynamics of rebels’ wartime humanitarian activities and the post-conflict implications of this form of rebel governance.
India’s Infrastructure Building In Africa: South-South Cooperation And The Abstraction Of Responsibility
Authors: Dye Barnaby
Published: April 2022

A growing debate concerns the developmental implications of booming relations between ‘Southern’ powers and countries across Africa. Whilst mainstream commentary worries about nefarious influences, others explore supposedly increasing ‘African agency’, a term capturing the ability of African states to define their international relations. South-South Cooperation, given its supposed principles asserting sovereignty, non-interventionism, and demand-led projects, is understood to boost such agency. This article analyses such claims with a detailed case study of Indian governmental infrastructure financing in Africa, the Nyabarongo Dam in Rwanda, filling a significant gap concerning under-researched India–Africa relations. Originally, South-South cooperation was rooted in a programme that combined technical cooperation with a radical political critique of global power and a call for reform. However, this study of India’s concessional finance suggests that in its twenty-first century manifestation, South-South Cooperation is often decoupled from a political programme, leaving only open-ended, depoliticized state-to-state cooperation initiatives. The article demonstrates that whilst India’s development cooperation generated useful opportunities, it acted to empower companies and exacerbated the Rwandan state’s structural regulatory weaknesses. The article traces this to the policymaking practices of India’s development cooperation, showing that a decoupling of political ambitions results in a narrow state-to-state focus with an abdication of responsibility for development outcomes, marginalizing accountability to average African citizens.
Mandatory vaccination against COVID-19 for health and social care workers caring for older people
Authors: Gordon Adam L , Achterberg Wilco P , van Delden Johannes J M
Published: April 2022

The COVID-19 pandemic has particularly adversely affected older people with frailty and functional dependency. Essential regular contact with care staff has been evidenced as an important source of infection for this group. Vaccinating care staff can reduce the incidence, duration and severity of infection, preventing onward transmission to older people and minimising the harm associated with discontinuity caused by staff absence. Voluntary vaccination programmes for staff are more likely to be effective when associated with information and education, community engagement and financial incentives, but programmes using all of these approaches have failed to establish consistently high vaccination rates among care staff during the pandemic. Mandatory vaccination, proposed as a solution in some countries, can increase vaccination rates. It is only ethical if a vaccine is effective and cost-effective, the risk associated with vaccinating care workers is proportionate to the risk reduction achieved through vaccination, and where all efforts to encourage voluntary vaccination have been exhausted. Even when these conditions have been met, careful attention is required to ensure that the penalties associated with conscientious objection are proportionate and to ensure that implementation is equitable in a way that does not disadvantage particular groups of staff.