bluuebunny/crossref_metadata_2025 huggingface dataset:
125 Jahre Deutsches Zentralkomitee zur Bekämpfung der Tuberkulose e. V. (DZK)
Authors: Loddenkemper R. , Konietzko N. , Seehausen V. , Bauer T. , Pfeifer M.
Published: November 2020

Das Deutsche Zentralkomitee zur Bekämpfung der Tuberkulose e. V. (DZK) feiert in diesem Jahr seinen 125. Geburtstag. Aus diesem Anlass blickt das DZK als eine der weltweit ältesten TB-Organisationen auf seine Entwicklung in diesen 125 Jahren zurück. Die Ergebnisse werden detailliert in einem umfangreichen Buch geschildert und in diesem Artikel zusammengefasst. Hierin spiegeln sich die vielfältigen politischen Veränderungen mit ihren Auswirkungen auf das DZK wider, angefangen vom Kaiserreich, über die Weimarer Republik, das sog. „Dritte Reich“, die beiden nach dem Zweiten Weltkrieg getrennten deutschen Staaten und die jetzige Bundesrepublik Deutschland. Die Tuberkulose (TB) war zur Gründungszeit noch die beherrschende Volkskrankheit in Deutschland, heute ist sie weltweit die führende Infektionskrankheit. Als Folge von Migration ist davon auch Deutschland betroffen. Nach zwischenzeitlich – speziell 2015/2016 – deutlich angestiegenen Erkrankungszahlen (insbesondere bei den nicht in Deutschland geborenen Neuerkrankten, die 2019 einen Anteil von 72 % hatten), die Auswirkungen der medikamentenresistenten TB (2019 hatten 11,4 % aller Neuerkrankungen irgendeine [jegliche] Resistenz [384 Fälle], darunter 87 Fälle mit einer MDR-TB und von diesen 8 Fälle mit einer XDR-TB und 27 Fälle einer Prä-XDR-TB) sowie auch der hohe Anteil offener und damit hoch infektiöser Lungentuberkulosen (81,5 % in 2019) zeigen eindrücklich, dass die TB nach wie vor ein auch in Deutschland nicht zu unterschätzendes Gesundheitsproblem darstellt, welches sich zunehmend in Risikogruppen konzentriert (sozial benachteiligte Personen, Menschen aus Hochprävalenzländern, Obdachlose, Drogenabhängige, Alkoholkranke, HIV-Infizierte). Dem DZK kommt daher in der Kontrolle der TB auch heute noch eine wichtige Rolle zu als Bindeglied zwischen den mit der Bekämpfung der TB betrauten nationalen und internationalen Institutionen.
Trainee participation during screening colonoscopy does not affect ADR at subsequent surveillance, but may result in early follow-up
Authors: Eckardt Alexander J. , Kheder Joan , Basil Anjali , Silverstein Taryn , Patel Krunal , Mahmoud Mohamed , Al-Azzawi Yasir , Ellis Daniel , Gillespie William , Carrasquillo Vega Yoel , Person Sharina D. , Levey John M.
Published: November 2020

Background and study aims Training future endoscopists is essential to meet rising demands for screening and surveillance colonoscopies. Studies have shown conflicting results regarding the influence of trainees on adenoma detection rates (ADR). It is unclear whether trainee participation during screening adversely affects ADR at subsequent surveillance and whether it alters surveillance recommendations.

Patients and methods A retrospective analysis of average-risk screening colonoscopies and surveillance exams over a subsequent 10-year period was performed. The initial inclusion criteria were met by 5208 screening and 2285 surveillance exams. Patients with poor preparation were excluded. The final analysis included 7106 procedures, including 4922 screening colonoscopies and 2184 surveillance exams. Data were collected from pathology and endoscopy electronic databases. The primary outcome was the ADR with and without trainee participation. Surveillance recommendations were analyzed as a secondary outcome.

Results Trainees participated in 1131 (23 %) screening and in 232 (11 %) surveillance exams. ADR did not significantly differ (P = 0.19) for screening exams with trainee participation (19.5 %) or those without (21.4 %). ADRs were higher at surveillance exams with (22.4 %) and without (27.5 %) trainee participation. ADR at surveillance was not adversely affected by trainee participation during the previous colonoscopy. Shorter surveillance intervals were given more frequently if trainees participated during the initial screening procedure (P = 0.0001).

Conclusions ADR did not significantly differ in screening or surveillance colonoscopies with or without trainee participation. ADR at surveillance was not adversely affected by trainee participation during the previous screening exam. However, trainee participation may result in shorter surveillance recommendations.
Canaloplasty ab interno (AbiC) – 2-Year-Results of a Novel Minimally Invasive Glaucoma Surgery (MIGS) Technique
Authors: Kazerounian Sara , Zimbelmann Michael , Lörtscher Martin , Hommayda Sufian , Tsirkinidou Irene , Müller Maya
Published: November 2020

Purpose The aim of this study is to evaluate the long-term efficacy of a novel minimally invasive glaucoma surgery technique (MIGS), Ab interno Canaloplasty (AbiC).

Material and Methods For this retrospective cohort study, we analysed the data of 25 eyes of 23 patients with open angle glaucoma who underwent an AbiC (6 eyes) or in case of an additional cataract, a combined cataract-AbiC procedure (“phacocanaloplasty ab interno”, 19 eyes), respectively. Postoperatively, we investigated the intraocular pressure (IOP) and the number of still required IOP-lowering medication, as well as surgery-related complications.

Results Overall, the mean baseline IOP of 20.24 mmHg ± 5.92 (n = 25) was reduced to 10.64 mmHg ± 2.77 (n = 25, p < 0.001), 12.55 mmHg ± 3.33 (n = 22, p < 0.001) and 13.67 mmHg ± 2.15 (n = 21, p < 0.001) at 1 day, 1 year and 2 year follow-up visit, respectively. Compared to baseline, this implies a reduction in IOP of 47.4, 37.9 and 32.5%. An average glaucoma medication usage of 1.92 ± 1.04 was registered at baseline visit and was reduced to 0,05 ± 0,23 after 2 years of follow-up. 80% of patients were off medication. In 5 eyes (20%) further antiglaucomatous eye drops or surgical treatment were administered. The only surgical complications were hyphema in 5 eyes (20%) and a localized peripheral detachment of the Descemetʼs membrane in one eye (4%) with no late sequelae.

Conclusion AbiC performed independently or combined with cataract surgery seems to be a safe and effective MIGS-technique with good long-term regulation of IOP and low risk profile.
Endoscopic ultrasound-guided radiofrequency ablation of pancreatic neuroendocrine tumors: a case series
Authors: de Nucci Germana , Imperatore Nicola , Mandelli Enzo Domenico , di Nuovo Franca , d’Urbano Corrado , Manes Gianpiero
Published: November 2020

Background and study aims Surgery is the considered the therapeutic cornerstone for pancreatic neuroendocrine tumors (P-NETs), although burdened by high risk of significant adverse events. Recently, endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has been described for P-NETs. We aimed to evaluate the effectiveness and safety of EUS-RFA for treatment of P-NETs.

Patients and methods We prospectively included all consecutive patients with P-NET ≤ 20 mm who were treated with EUS-RFA and were followed-up for at least 12 months.

Results Ten patients (5 males, mean age 78.6 years, mean body mass index 28.2) with 11 P-NETs (mean size 14.5 mm; range 9 – 20 mm) localized in the pancreatic head (3 lesions), pancreatic body (5 lesions), and tail (3 lesions) underwent complete EUS ablation with one session of RFA. Complete ablation of P-NET was reached using a single-session RFA with a mean of 2.3 treatment applications per session. At both 6 – and 12-months computed tomography scans, all the patients had complete disappearance of lesions with radiological normalization. Regarding safety, only two cases of mild abdominal pain were recorded in two subjects with pancreatic head lesion, which were effectively treated with analgesics. The mean duration of hospital stay was 4 days (range 3 – 7 days).

Conclusions EUS-RFA is effective and safe in treating P-NETs. It may be considered an effective therapeutic option in the treatment of small P-NETs independently from their functional status.
EUS-guided intrahepatic biliary drainage: a large retrospective series and subgroup comparison between percutaneous drainage in hilar stenoses or postsurgical anatomy
Authors: Vanella Giuseppe , Bronswijk Michiel , Maleux Geert , van Malenstein Hannah , Laleman Wim , Van der Merwe Schalk
Published: November 2020

Background and study aims Endoscopic ultrasound-guided intrahepatic biliary drainage (EUS-IBD) struggles to find a place in management algorithms, especially compared to percutaneous drainage (PTBD). In the setting of hilar stenoses or postsurgical anatomy data are even more limited.

Patients and methods All consecutive EUS-IBDs performed in our tertiary referral center between 2012 – 2019 were retrospectively evaluated. Rendez-vous (RVs), antegrade stenting (AS) and hepatico-gastrostomies (HGs) were compared. The predefined subgroup of EUS-IBD patients with proximal stenosis/surgically-altered anatomy was matched 1:1 with PTBD performed for the same indications. Efficacy, safety and events during follow-up were compared.

Results One hundred four EUS-IBDs were included (malignancies = 87.7 %). These consisted of 16 RVs, 43 ASs and 45 HGs. Technical and clinical success rates were 89.4 % and 96.2 %, respectively. Any-degree, severe and fatal adverse events (AEs) occurred in 23.3 %, 2.9 %, and 0.9 % respectively. Benign indications were more common among RVs while proximal stenoses, surgically-altered anatomy, and disconnected left ductal system among HGs. Procedures were shorter with HGs performed with specifically designed stents (25 vs. 48 minutes, P = 0.004) and there was also a trend toward less dysfunction with those stents (6.7 % vs. 30 %, P = 0.09) compared with previous approaches. Among patients with proximal stenosis/surgically-altered anatomy, EUS-IBD vs. PTBD showed higher rates of clinical success (97.4 % vs. 79.5 %, P = 0.01), reduced post-procedural pain (17.8 % vs. 44.4 %, p = 0.004), shorter median hospital stay (7.5 vs 11.5 days, P = 0.01), lower rates of stent dysfunction (15.8 % vs. 42.9 %, P = 0.01), and the mean number of reinterventions was lower (0.4 vs. 2.8, P < 0.0001).

Conclusions EUS-IBD has high technical and clinical success with an acceptable safety profile. HGs show comparable outcomes, which are likely to further improve with dedicated tools. For proximal strictures and surgically-altered anatomy, EUS-IBD seems superior to PTBD.
Effect of dynamic position changes on adenoma detection rate during colonoscope withdrawal: systematic review and meta-analysis
Authors: Nutalapati Venkat , Desai Madhav , Thoguluva-Chandrasekar Vivek Sandeep , Olyaee Mojtaba , Rastogi Amit
Published: November 2020

Background and study aims The adenoma detection rate (ADR) is an important quality metric of colonoscopy. Higher ADR correlates with lower incidence of interval colorectal cancer. ADR is variable between endoscopists and depends upon the withdrawal technique amongst other factors. Dynamic position change (lateral rotation of patients with a view to keep the portion of the colon being inspected at a higher level) helps with luminal distension during the withdrawal phase. However, impact of this on ADR is not known in a pooled sample. We performed a systematic review and meta-analysis to study the impact of dynamic position changes during withdrawal phase of colonoscopy on ADR

Methods A comprehensive search of MEDLINE, EMBASE, Google Scholar, and the Cochrane Database was conducted from each database’s inception to search for studies comparing dynamic position changes during colonoscope withdrawal with static left lateral position (control). The primary outcome of interest was ADR. Other studied outcomes were polyp detection rate (PDR) and withdrawal time. Outcomes were reported as pooled odds ratio (OR) with 95 % confidence intervals (CI) with statistical significance (P < 0.05). RevMan 5.3 software was used for statistical analysis.

Results Six studies were included in our analysis with 2860 patients. Of these, dynamic position change was implemented in 1177 patients while 1183 patients served as the controls. ADR was significantly higher in the dynamic position change group with pooled OR 1.36 (95 % CI, 1.15–1.61; P < 0.01). There was low heterogeneity in inclusion studies (I2 = 0 %). PDR was numerically higher in position change group (53.4 % vs 49.6 %) but not statistically significant (P = 0.16). Mean withdrawal time did not significantly change with dynamic position change (12.43 min vs 11.46 min, P = 0.27).

Conclusion Position change during the withdrawal phase of colonoscopy can increase the ADR compared to static left lateral position. This is an easy and practical technique that can be implemented to improve ADR.
Novel upper gastrointestinal monitoring system to track upper gastrointestinal bleeding: A pilot study
Authors: Chuang Chiao-Hsiung , Chen Chien-Cheng , Wu Jhong-Han , Hong Ming-Yuan , Kang Jui-Wen , Kuo Hsin-Yu , Huang Chien-Jui , Chen Chiung-Yu
Published: November 2020

Background and study aims Early detection of upper gastrointestinal (UGI) rebleeding is not easy by observing clinical symptoms. We developed a novel UGI monitoring system and aimed to test its feasibility of continuous tracking of UGI bleeding.

Patients and methods A prospective study was conducted on patients with moderate to high risk of rebleeding. The UGI monitoring system was installed to monitor their gastric contents. It would alarm if rebleeding was suspected and the physician could review the images to make a further decision. The patient’s comfort level was also evaluated.

Results Sixteen patients were enrolled. Rebleeding occurred in one patient and was detected by this system more than 5 hours earlier than with clinical symptoms. The interobserver reliability for reviewing the images to define the blood clearance in the stomach was excellent (intraclass correlation coefficient 0.79–0.96). The comfort level assessed by patients was 1.90 ± 1.39 (on the scale of 0–5).

Conclusions This pilot study demonstrated the potential of this UGI monitoring system for early detection of rebleeding.
Can Hematological Parameters be a Indicator Risk Factor in the Development of Retinopathy of Prematurity?
Authors: Celik Kiymet , Ekinci Dilbade , Asena Muhammet , Matur Nilufer Okur
Published: November 2020

Background Hematological parameters have been investigated as being indicative of increased inflammatory response in morbidity of very preterm infants. This study aims to determine whether the hematologic parameters and ratios of preterms can be an indicative risk factor for the development of retinopathy of prematurity (ROP).

Materials-Methods This retrospective cohort study examined newborns born before 32 weeks. Twenty-three patients treated with the diagnosis of ROP were included in the patient group. The control group included 23 patients who did not have ROP (no-ROP). Medical records of eligible preterm infants were retrospectively reviewed. Hemogram samples obtained from all patients during the first 24 h of life and samples of their mothers obtained before delivery were evaluated. The hemogram parameters of white blood cell (WBC) count, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, lymphocyte/monocyte ratio, and platelet mass index were calculated.

Results No difference was observed between the groups in terms of demographic data. In terms of hematological parameters, maternal WBC counts of ROP patients were significantly higher than those of no-ROP patients and WBC counts of ROP patients were significantly lower than those of no-ROP patients.

Conclusions This study found that high WBC counts in mothers before delivery and/or low WBC counts in preterms during the first postnatal day were higher in developed ROP. These results could lead to the development of prospective studies to assess the real prognostic value of WBC in ROP.
Rhodium-Catalyzed, Phosphorus(III)-Directed Hydroarylation of Internal Alkynes: Facile and Efficient Access to New Phosphine Ligands
Authors: Wang Minyan , Shi Zhuangzhi , Luo Huanhuan , Wang Dawei
Published: November 2020

Organophosphines are an important class of ligands widely used in organic chemistry. Although great progress has recently been made in the rapid construction of new phosphines through Rh- or Ru-catalyzed C–H bond functionalizations, synthetic access to more diverse phosphines remains a challenge. We describe an efficient process for the rhodium-catalyzed phosphorus(III)-directed hydroarylation of internal alkynes to generate various alkenylated and 2′,6′-dialkenylated biarylphosphines with high selectivity. A range of diverse alkynes and phosphines were effectively prepared with broad functional-group compatibility under the optimized conditions. In addition, the developed protocol can be extended to modify chiral phosphine ligands, providing enantioenriched alkenylated phosphines without erosion of the enantiomeric excess.
Patient Portal, Patient-Generated Images, and Medical Decision-Making in a Pediatric Ambulatory Setting
Authors: Ginting Karolin , Stolfi Adrienne , Wright Jordan , Omoloja Abiodun
Published: November 2020

Background Electronic health record (EHR) patient portals are a secure electronic method of communicating with health care providers. In addition to sending secure messages, images, and videos generated by families can be sent to providers securely. With the widespread use of smart phones, there has been an increase in patient-generated images (PGI) sent to providers via patient portals. There are few studies that have evaluated the role of PGI in medical decision-making.

Objectives The study aimed to characterize PGI sent to providers via a patient portal, determine how often PGI-affected medical decision-making, and determine the rate of social PGI sent via patient portal.

Methods A retrospective chart review of PGI uploaded to a children's hospital's ambulatory patient portal from January 2011 to December 2017 was conducted. Data collected included patient demographics, number and type of images sent, person sending images (patient or parent/guardian), and whether an image-affected medical decision-making. Images were classified as medical related (e.g., blood glucose readings and skin rashes), nonmedical or administrative related (e.g., medical clearance or insurance forms), and social (e.g., self-portraits and camp pictures).

Results One hundred forty-three individuals used the portal a total of 358 times, sending 507 images over the study period. Mean (standard deviation) patient age was 9.5 (5.9) years, 50% were females, 89% were White, and 64% had private insurance. About 9% of images were sent directly by patients and the rest by parents/guardians. A total of 387 (76%) images were sent for medical related reasons, 20% for nonmedical, and 4% were deemed social images. Of the 387 medical related images, 314 (81%) affected medical decision-making.

Conclusion PGI-affected medical decision-making in most cases. Additional studies are needed to characterize use of PGI in the pediatric population.
Serial Evaluation of Haemostasis Following Acute Trauma Using Rotational Thromboelastometry in Dogs
Authors: Herrero Yaiza , Schefer Rahel Jud , Muri Benjamin M. , Sigrist Nadja E.
Published: November 2020

Objective The aim of this study was to describe the coagulation status of traumatized dogs over the first 24 hours after admission.

Study Design In 33 dogs presenting within 6 hours after trauma blood was sampled for rotational thromboelastometry (ROTEM), thrombocyte number and venous blood gas analysis at presentation and 6 and 24 hours thereafter. At each time point, dogs were defined as hypo-, normo- or hypercoagulable based on extrinsic, intrinsic and fibrinogen ROTEM profiles.

Results Significantly more dogs (11/33) presented hypocoagulable compared with 6 hours (p = 0.046) and 24 hours (p = 0.008) thereafter and none presented hypercoagulable. Significantly more dogs were hypercoagulable (6/23, p = 0.014) and no dog was hypocoagulable at 24 hours compared with presentation. All evaluated ROTEM parameters except maximum lysis were significantly more hypocoagulable at presentation compared with 24 hours thereafter.

Conclusion Hypocoagulability is more common in acutely traumatized dogs than previously described. Dogs were hypo- or normocoagulable at presentation and the coagulation status changed to normo- or hypercoagulability over the first 24 hours. Clotting times, clot formation and clot firmness but not clot lysis were significantly altered at presentation compared with 24 hours and fibrinogen concentration or function may play an important role in the dynamic change of coagulation state over time.
Effect of Induced Incomplete Ossification of the Humeral Condyle on Ex Vivo Humeral Condylar Biomechanics
Authors: Scheuermann Logan M. , Conzemius Michael G.
Published: November 2020

Objective The aim of this study was to investigate the effects of an induced incomplete ossification of the humeral condyle (IOHC) lesion on ex vivo canine humeral condylar biomechanics.

Study Design Nine paired cadaveric elbows were collected from mature dogs weighing between 20 and 25 kg. Left and right limbs were randomized to IOHC or normal groups. Limbs were prepared for mechanical testing; ligaments were preserved and an IOHC lesion was created. Elbows were potted, positioned into a biomaterials testing system at an angle of 135 degrees and axially loaded to failure at a rate of 30 mm/minute.

Results Induced IOHC lesions reduced peak load (p = 0.02) when compared with an intact humerus. There was no difference between stiffness (p = 0.36) of intact humeri or humeri with an induced IOHC lesion. An induced IOHC lesion increased (p = 0.012) the probability of intracondylar fracture under load.

Conclusion Cadaveric humeri are weakened by the creation of an intracondylar osteotomy and fractures secondary to induced IOHC are similar to spontaneous humeral condylar fractures. These findings support the hypothesis that naturally occurring IOHC weakens the humeral condyle and may predispose to humeral condylar fracture.
Trajectories of regional cooperation: a comparative analysis
Authors: Panke Diana , Starkmann Anna
Published: November 2020

Cooperation between states takes place in International Organizations (IOs) and Regional Organizations (ROs). Since we know more about the evolution of cooperation in IOs than ROs, this paper examines trajectories of regional cooperation. Based on a novel dataset, it provides a descriptive analysis of how all 76 ROs developed over time. This reveals that regional cooperation evolved in two waves with respect to RO size as well as the policy areas of cooperation. The paper adopts an explorative approach to examine these patterns. This reveals that ROs with regional courts and ROs which adopt a model of dynamic change are more likely to broaden their policy scopes. In addition, during the Cold War, ROs with initially broad policy scopes were less likely to obtain additional competencies, while after 1990 ROs were more likely to broaden their policy scopes when they are large in size, when their members are economically strong and when majority decisions are possible in their day-to-day operation.
Positive solutions for a relativistic nonlinear Schrödinger equation with square-root nonlinearity
Authors: Wang Youjun , Zhang Yimin
Published: November 2020

In this paper, we consider the existence of positive solutions for a relativistic nonlinear Schrödinger equation with square-root nonlinearity. If N = 2, the existence and uniqueness of ground states for this equation was obtained by Colin [Adv. Differ. Equations 8, 1 (2003)]. In this paper, when N = 3, by modifying the original problem and proving some estimates, the existence of the positive solution uω(x) for this equation is obtained. In the meantime, uω(x) → 0 as ω → 0+. Moreover, using the same technique, the existence of positive solutions for more generalized nonlinear Schrödinger equations with square-root nonlinearity is also obtained.
Development of highly sensitive nanoscale transition edge sensors for gigahertz astronomy and dark matter search
Authors: Paolucci Federico , Buccheri Vittorio , Germanese Gaia , Ligato Nadia , Paoletti Riccardo , Signorelli Giovanni , Bitossi Massimiliano , Spagnolo Paolo , Falferi Paolo , Rajteri Mauro , Gatti Claudio , Giazotto Francesco
Published: November 2020

Terahertz (THz) and sub-terahertz (sub-THz) band detection has a key role in both fundamental interactions physics and technological applications, such as medical imaging, industrial quality control, and homeland security. In particular, transition edge sensors (TESs) and kinetic inductance detectors (KIDs) are the most employed bolometers and calorimeters in the THz and sub-THz band for astrophysics and astroparticles research. Here, we present the electronic, thermal, and spectral characterization of an aluminum/copper bilayer sensing structure that, thanks to its thermal properties and a simple miniaturized design, could be considered a perfect candidate to realize an extremely sensitive class of nanoscale TES (nano-TES) for the giga–terahertz band. Indeed, thanks to the reduced dimensionality of the active region and the efficient Andreev mirror heat confinement, our devices are predicted to reach state-of-the-art TES performance. In particular, as a bolometer the nano-TES is expected to have a noise equivalent power of 5×10−20 W/Hz and a relaxation time of ∼10 ns for the sub-THz band, typical of cosmic microwave background studies. When operated as a single-photon sensor, the devices are expected to show a remarkable frequency resolution of 100 GHz, pointing toward the necessary energy sensitivity requested in laboratory axion search experiments. Finally, different multiplexing schemes are proposed and sized for imaging applications.
Drive-pressure optimization in ramp-wave compression experiments through differential evolution
Authors: Sterbentz Dane M. , Gambino James R. , Myint Philip C. , Delplanque Jean-Pierre , Springer H. Keo , Marshall Michelle C. , Belof Jonathan L.
Published: November 2020

Ramp-wave dynamic-compression experiments are used to examine quasi-isentropic loading paths in materials. The gradual and continuous increase in pressure created by ramp waves make these types of experiments ideal for studying nonequilibrium material behavior, such as solidification kinetics. In ramp-wave compression experiments, the input drive pressure to the experimental setup may be exerted through one of a number of different mechanisms (e.g., magnetic fields, gas-gun-driven impactors, or high-energy lasers) and is generally required for simulating such experiments. Yet, regardless of the specific mechanism, this drive pressure cannot be measured directly (measurements are generally taken at a location near the back of the experimental setup through a transparent window), leading to an inverse problem where one must determine the drive pressure at the front of the experimental setup (i.e., the input) that corresponds to the particle velocity (the output) measured near the back of the experimental setup. We solve this inverse problem using a heuristic optimization algorithm, known as differential evolution, coupled with a multiphysics, hydrodynamics code that simulates the compression of the experimental setup. By running many rounds of forward simulations of the experimental setup, our optimization process iteratively searches for a drive pressure that is optimized to closely reproduce the experimentally measured particle velocity near the back of the experimental setup. While our optimization methodology requires a significant number of hydrodynamics simulations to be conducted, many of these can be performed in parallel, which greatly reduces the time cost of our methodology. One novel aspect of our method for determining the drive pressure is that it does not require physical modeling of the drive mechanism and can thus be broadly applied to many types of ramp-compression experiments, regardless of the drive mechanism.
Fingering instability in Marangoni spreading on a deep layer of polymer solution
Authors: Ma Xue , Zhong Menglin , He Yifeng , Liu Zhanwei , Li Zhenzhen
Published: November 2020

Spreading on the free surface of a complex fluid is ubiquitous in nature and industry, such as drug delivery, oil spill, and surface treatment with patterns. Here, we report on a fingering instability that develops during Marangoni spreading on a deep layer of the polymer solution. In particular, the wavelength depends on the molecular weight and concentration of the polymer solution. We use the transmission lattice method to characterize the free surface morphology during spreading and the finger height at the micron scale. We use the Maxwell model to explain the spreading radius, which is dominated by elasticity at small time scales and by viscous dissipation at large time scales. In a viscous regime, with consideration of shear thinning, the spreading radius follows the universal 3/4 power law. Our model suggests a more generalized law of the spreading radius than the previous laws for Newtonian fluids. Furthermore, we give a physical explanation on the origin of the fingering instability as due to normal stresses at high shear rates generating a high contact angle, providing a necessary condition for the fingering instability. The normal stress also generates the elastic deformation at the leading edge and so selects the wavelength of the fingering instability. Understanding the spreading mechanism on a layer of viscoelastic fluid has a particular implication in airway drug delivery and surface coating.
Calibrated reservoir computers
Authors: Mabrouk Y. A. , Räth C.
Published: November 2020

We observe the presence of infinitely fine-scaled alternations within the performance landscape of reservoir computers aimed for chaotic data forecasting. We investigate the emergence of the observed structures by means of variations of the transversal stability of the synchronization manifold relating the observational and internal dynamical states. Finally, we deduce a simple calibration method in order to attenuate the thus evidenced performance uncertainty.
Gravity with dynamical torsion
Authors: Katanaev M O
Published: November 2020

We propose four simple Lagrangians for gravity models with dynamical torsion which are free from ghosts and tachyons. The torsion propagates two massive or massless particles of spin 1± and 0± besides the massless graviton 2+ propagated by metric.
Liquid oscillating in a U-tube of variable cross section
Authors: Mungan Carl E , Sheldon-Coulson Garth A
Published: November 2020

A liquid is set into oscillations in a vertical manometer of smoothly varying cross-sectional area open at both ends to the atmosphere. Ignoring viscous damping, the displacement of either free surface and the pressure at any point in the liquid can be calculated using the unsteady Bernoulli equation which is shown to be consistent with conservation of mechanical energy. If the cross section is constant, the equations are analytically solvable; simple harmonic motion is found for the surface displacement as a function of time, and the pressure variation as a function of depth is in accordance with Newton’s second law. More generally, however, numerical solution of the equations is necessary, as illustrated for the example of a U-tube whose radius is linearly tapered from one end to the other. The level of presentation is appropriate for an upper level undergraduate course in fluid mechanics.
A superconducting Fabry–Perot cavity for trapping cold molecules
Authors: Tahsildaran F Fatemeh S , Vashishta Manish , Farahbod Amir Hossein , Malekfar Rasoul , Djuricanin Pavle , Enomoto Katsunari , Momose Takamasa
Published: November 2020

A superconducting Fabry–Perot microwave cavity for a molecular trap was designed, constructed and characterized. The cavity was designed to create intense microwave fields that are sufficient to trap cold polar molecules by the AC Stark force. By coating the mirror surfaces with a superconducting material, an unloaded quality factor of up to 1.1 × 106 at 24.087 GHz was achieved at a temperature of 2.24 K. The field strength of 1.06 MV m−1 obtained for a TEM02 transverse mode with an input power of 10 W is sufficiently intense to trap ammonia molecules at a temperature of 85 mK, which is achievable by a conventional Stark molecular decelerator. We have also implemented an ion optics assembly for sensitive detection of molecules inside the microwave cavity by resonance enhanced multi-photon ionization.
Electron impact single ionization of hydrogen molecule by twisted electron beam
Authors: Dhankhar Nikita , Choubisa R
Published: November 2020

In this communication, we present the results of the five-fold differential cross-section (5DCS) and triple differential cross-section (TDCS) for the (e, 2e) process on molecular hydrogen (H2) by the plane wave and the twisted electron beam impact. The formalism is developed within the first Born approximation using the plane wave and the twisted wave for the incident electron beam. We describe the plane wave, Heitler–London type wave function, Coulomb wave for the scattered electron, the H2 molecular state, and the ejected electron. We compare the angular profiles of the 5DCS and TDCS for the different values of orbital angular momentum (OAM) number m of the twisted electron beam with that of the plane wave beam. We also present the 5DCS for different molecular orientations and study the effect of m on the 5DCS. We further investigate the influence of the twisted electron beam on the (e,2e) process on the H2 molecule from the perspective of the ‘Young-type’ interference of the scattered waves, emanating from the two atomic centers of the H2 molecule. We also study the TDCS for macroscopic H2 target to explore the effect of opening angle (θ
p) of the twisted electron beam on the TDCS. Our results clearly show the effect of the twisted electron’s OAM number (m) and the opening angle (θ
p) on the 5DCS and TDCS of the molecular hydrogen.
Pre-existence probability for the ternary fission of Cf isotopes
Authors: Kokila C , Balasubramaniam M
Published: November 2020

The pre-existence probability for the spontaneous ternary breakup of neutron deficient to neutron rich parent nuclei of Cf isotopes from 242Cf to 256Cf with different third fragments such as 4He, and N = Z and N ≠ Z clusters like 12,14C, 16,20O, 20,24Ne, and 48,50Ca is studied here. A simple analytical formula is used to calculate the pre-existence probability. The ternary breakup combinations are computed by the charge minimization procedure. For 4He as the third fragment, the inclusion of deformation shifts the most probable distribution of 252Cf parent system from 132Sn to 140Xe which is as per the experimental observations. An enhancement in the relative yield is observed when the distance between the main fission fragment is reduced. In the spherical calculations for A
3 = 12C and 14C, the yield distribution is identical and the heavy group remains as 132Sn but for the deformed calculations with A
3 = 14C, the light group remains the same as 114Ru for neutron-rich parent nuclei. For O and Ne clusters, with the increase in neutron number of parent system, the asymmetric yield distribution changes to symmetric one. For heavier clusters, 48Ca and 50Ca, the favorable fragmentation is observed as Sn + Ni, which is in agreement with experimental predictions.
Thermodynamic model of the coupled valence and spin state transition in cobaltates
Authors: Hardy V , Bréard Y , Guillou F
Published: November 2020

A class of cobalt-based oxides exhibits a peculiar type of transition, entangling valence and spin state degrees of freedom of 4f and 3d elements. It constitutes one of the most spectacular illustrations of the interplay between charge, spin and lattice degrees of freedom in strongly correlated materials. In this work, we present a thermodynamic model capable to reproduce the main features of this transition. Our approach is based on the minimization of a free energy combining the contributions of two sublattices and the interaction between them. The coupling energies introduced in the model are related to well-known chemical pressure effects in the perovskite structure. The results of this model are compared to experimental data derived from x-ray absorption spectroscopy.
Numerical investigation of the effect of rate-sensitivity, non-octahedral slip and grain shape on texture evolution during hot rolling of aluminum alloys
Authors: Falkinger Georg , Mitsche Stefan
Published: November 2020

Based on texture simulations with a viscoplastic self-consistent polycrystal algorithm, this contribution presents a comprehensive investigation of the effect of the rate-sensitivity exponent, the relative strength of non-octahedral slip modes as well as the grain shape on texture evolution. The simulations are validated with texture measurements of samples from the industrial hot rolling process at different rolling reductions. Simulated textures at different hot rolling temperatures are compared with experimental findings from the literature. The present investigation indicates, that texture simulations must include three non-octahedral slip systems, use temperature dependent rate-sensitivity exponents and account for the evolution of grain shape.
Thermodynamic dislocation theory: application to bcc-crystals
Authors: Le K C , Dang S L , Luu H T , Gunkelmann N
Published: November 2020

This paper presents the thermodynamic dislocation theory containing several modifications over its first version which was originally proposed by Langer, Bouchbinder, and Lookman [5]. Employing a small set of physics-based material parameters identified by the large scale least squares analysis, we show that the theory can fit the stress–strain curves of bcc crystals niobium, tantalum, tungsten, and vanadium over a wide range of temperatures and strain rates.
Field-assisted growth of one-dimensional ZnO nanostructures with high defect density
Authors: Phuah Xin Li , Cho Jaehun , Akriti  , Dou Letian , Rheinheimer Wolfgang , García R Edwin , Zhang Xinghang , Wang Haiyan
Published: November 2020

One-dimensional ZnO nanostructures have shown great potential in electronics, optoelectronics and electromechanical devices owing to their unique physical and chemical properties. Most of these nanostructures were grown by equilibrium processes where the defects density is controlled by thermodynamic equilibrium. In this work, flash sintering, a non-equilibrium field-assisted processing method, has been used to synthesize ZnO nanostructures. By applying a high electric field and limiting a low current flow, ZnO nanorods grew uniformly by a vapor–liquid–solid mechanism due to the extreme temperatures achieved near the hot spot. High density basal stacking faults in the nanorods along with ultraviolet excitonic emission and a red emission under room temperature demonstrate the potential of defect engineering in nanostructures via the field-assisted growth method.
Thermoelectric properties of antimony selenide hexagonal nanotubes
Authors: Hernandez Jose A , Fonseca Luis F , Pettes Michael T , Jose-Yacaman Miguel
Published: November 2020

Antimony selenide (Sb2Se3) is a material widely used in photodetectors and relatively new as a possible material for thermoelectric applications. Taking advantage of the new properties after nanoscale fabrication, this material shows great potential for the development of efficient low temperature thermoelectric devices. Here we study the synthesis, the crystal properties and the thermal and thermoelectric transport response of Sb2Se3 hexagonal nanotubes (HNT) in the temperature range between 120 and 370 K. HNT have a moderate electrical conductivity ∼102 S m−1 while maintaining a reasonable Seebeck coefficient ∼430 μV K−1 at 370 K. The electrical conductivity in Sb2Se3 HNT is about 5 orders of magnitude larger and its thermal conductivity one half of what is found in bulk. Moreover, the calculated figure of merit (ZT) at room temperature is the largest value reported in antimony selenide 1D structures.
Investigation of electron transfer between single plasmon and graphene by dark field spectroscopy
Authors: Du Qian , Dou Zheng , Zhang Wenjia , Krüger Katja , Zhao Shuang , Yue Zhao , Liu Guohua
Published: November 2020

We investigated the electron transfer time between single plasmonic gold nanoparticles and graphene with our home-build spectral imaging dark-field microscope. The process of electron transfer is supposed to be shuttling of hot electrons on the nanoparticle-graphene interface, resulting in a slight broadening of the scattering spectrum. For detecting the minor spectrum broadening, we firstly characterized our setup systematically and then calibrated its intrinsic error. We found the mechanism of a common but normally neglected setup error, scattering spectrum broadening, which is caused by the bandwidth of the incident light and could exist in most fast dark-field microscopy setups. We corrected the linewidth of plasmon scattering spectra theoretically by both numerical and analytical solution, and then realized it experimentally by tuning the bandwidth of the incident light. After calibration, we revisited scattering spectra of 700 small aspect ratio nanorods on glass and monolayer graphene revealing a typical 14.3 meV linewidth broadening. Furthermore, we measured four other kinds of gold nanoparticles on glass, mono- and bilayer graphene for deeper understanding of the electron transfer. A common linewidth broadening is found for each kind of particle agreeing well with previous theory. However, an unconventional linewidth narrowing is also discovered for big particles whose resonance wavelength is close to the near infrared region. It implies a competitive mechanism in the electron transfer process which could not only increase the damping of small particles, causing a linewidth broadening, but also simplify the electric field pattern for big particles, leading to a linewidth narrowing, according to our Mie theory simulation.
Implementation of oxide vertical channel TFTs with sub-150 nm channel length using atomic-layer deposited IGZO active and HfO2 gate insulator
Authors: Ryoo Hyun-Joo , Seong Nak-Jin , Choi Kyu-Jeong , Yoon Sung-Min
Published: November 2020

We fabricated vertical channel thin film transistors (VTFTs) with a channel length of 130 nm using an ALD In–Ga–Zn–O (IGZO) active channel and high-k HfO2 gate insulator layers. Solution-processed SiO2 thin film, which exhibited an etch selectivity as high as 4.2 to drain electrode of indium-tin oxide, was introduced as a spacer material. For the formation of near-vertical sidewalls of the spacer patterns, the drain and spacer were successively patterned by means of two-step plasma etching technique using Ar/Cl2 and Ar/CF4 etch gas species, respectively. The SiO2 spacer showed smooth surface morphology (R
q = 0.45 nm) and low leakage current component of 10–6 A cm−2 at 1 MV cm−1, which were suggested to be appropriate for working as spacer and back-channel. The fabricated VTFT showed sound transfer characteristics and negligible shifts in threshold voltage against the bias stresses of +5 and −5 V for 104 s, even though there was abnormal increase in off-currents under the positive-bias stress due to the interactions between hydrogen-related defects and carriers. Despite the technical limitations of patterning process, our fabricated prototype IGZO VTFTs showed good operation stability even with an ultra-short channel length of 130 nm, demonstrating the potential of ALD IGZO thin film as an alternative channel for highly-scaled electronic devices.
Molten salt-confined pyrolysis towards carbon nanotube-backboned microporous carbon for high-energy-density and durable supercapacitor electrodes
Authors: Liu Siliang , Feng Qichun , Zhang Chao , Liu Tianxi
Published: November 2020

The development of a green and scalable construction of a three-dimensional (3D) hierarchically porous carbon as an electrode material for supercapacitors is promising but challenging. Herein, a carbon nanotube-backboned microporous carbon (CNT-MPC) was prepared by molten salt-confined pyrolysis, during which the salt eutectics simultaneously acted as a high-temperature reaction solvent and reusable template. Among the CNT-MPC, the CNT backbone provided a 3D conductive framework, whereas the MPC sheath possessed integrated mesopores and micropores as an efficient ion reservoir. As a result, the as-obtained CNT-MPC exhibited a high specific capacitance of 305.6 F g−1 at 1 A g−1, high energy density of 20.5 W h kg−1 and excellent cyclic stability with no capacitance losses after 50 000 cycles. The molten-salt confined pyrolysis strategy therefore provides a low-cost, environmentally-friendly and readily industrialized route to develop a hierarchically porous carbon that is highly required for high-energy-density and durable supercapacitors.
Out-of-field doses for scanning proton radiotherapy of shallowly located paediatric tumours—a comparison of range shifter and 3D printed compensator
Authors: Wochnik A , Stolarczyk L , Ambrožová I , Davídková M , De Saint-Hubert M , Domański S , Domingo C , Knežević Ž , Kopeć R , Kuć M , Majer M , Mojżeszek N , Mares V , Martínez-Rovira I , Caballero-Pacheco M Á , Pyszka E , Swakoń J , Trinkl S , Tisi M , Harrison R , Olko P
Published: November 2020

The lowest possible energy of proton scanning beam in cyclotron proton therapy facilities is typically between 60 and 100 MeV. Treatment of superficial lesions requires a pre-absorber to deliver doses to shallower volumes. In most of the cases a range shifter (RS) is used, but as an alternative solution, a patient-specific 3D printed proton beam compensator (BC) can be applied. A BC enables further reduction of the air gap and consequently reduction of beam scattering. Such pre-absorbers are additional sources of secondary radiation. The aim of this work was the comparison of RS and BC with respect to out-of-field doses for a simulated treatment of superficial paediatric brain tumours. EURADOS WG9 performed comparative measurements of scattered radiation in the Proteus C-235 IBA facility (Cyclotron Centre Bronowice at the Institute of Nuclear Physics, CCB IFJ PAN, Kraków, Poland) using two anthropomorphic phantoms—5 and 10 yr old—for a superficial target in the brain. Both active detectors located inside the therapy room, and passive detectors placed inside the phantoms were used. Measurements were supplemented by Monte Carlo simulation of the radiation transport. For the applied 3D printed pre-absorbers, out-of-field doses from both secondary photons and neutrons were lower than for RS. Measurements with active environmental dosimeters at five positions inside the therapy room indicated that the RS/BC ratio of the out-of-field dose was also higher than one, with a maximum of 1.7. Photon dose inside phantoms leads to higher out-of-field doses for RS than BC to almost all organs with the highest RS/BC ratio 12.5 and 13.2 for breasts for 5 and 10 yr old phantoms, respectively. For organs closest to the isocentre such as the thyroid, neutron doses were lower for BC than RS due to neutrons moderation in the target volume, but for more distant organs like bladder—conversely—lower doses for RS than BC were observed. The use of 3D printed BC as the pre-absorber placed in the near vicinity of patient in the treatment of superficial tumours does not result in the increase of secondary radiation compared to the treatment with RS, placed far from the patient.