bluuebunny/crossref_metadata_2025 huggingface dataset:
Solar Orbiter/RPW antenna calibration in the radio domain and its application to type III burst observations
Authors: Vecchio A. , Maksimovic M. , Krupar V. , Bonnin X. , Zaslavsky A. , Astier P. L. , Dekkali M. , Cecconi B. , Bale S. D. , Chust T. , Guilhem E. , Khotyaintsev Yu. V. , Krasnoselskikh V. , Kretzschmar M. , Lorfèvre E. , Plettemeier D. , Souček J. , Steller M. , Štverák Š. , Trávníček P. , Vaivads A.
Published: September 2021

Context.In order to allow for a comparison with the measurements from other antenna systems, the voltage power spectral density measured by the Radio and Plasma waves receiver (RPW) on board Solar Orbiter needs to be converted into physical quantities that depend on the intrinsic properties of the radiation itself (e.g., the brightness of the source).

Aims.The main goal of this study is to perform a calibration of the RPW dipole antenna system that allows for the conversion of the voltage power spectral density measured at the receiver’s input into the incoming flux density.

Methods.We used space observations from the Thermal Noise Receiver (TNR) and the High Frequency Receiver (HFR) to perform the calibration of the RPW dipole antenna system. Observations of type III bursts by the Wind spacecraft are used to obtain a reference radio flux density for cross-calibrating the RPW dipole antennas. The analysis of a large sample of HFR observations (over about ten months), carried out jointly with an analysis of TNR-HFR data and prior to the antennas’ deployment, allowed us to estimate the reference system noise of the TNR-HFR receivers.

Results.We obtained the effective length,leff, of the RPW dipoles and the reference system noise of TNR-HFR in space, where the antennas and pre-amplifiers are embedded in the solar wind plasma. The obtainedleffvalues are in agreement with the simulation and measurements performed on the ground. By investigating the radio flux intensities of 35 type III bursts simultaneously observed by Wind and Solar Orbiter, we found that while the scaling of the decay time as a function of the frequency is the same for the Waves and RPW instruments, their median values are higher for the former. This provides the first observational evidence that Type III radio waves still undergo density scattering, even when they propagate from the source, in a medium with a plasma frequency that is well below their own emission frequency.
The solar carbon, nitrogen, and oxygen abundances from a 3D LTE analysis of molecular lines
Authors: Amarsi A. M. , Grevesse N. , Asplund M. , Collet R.
Published: September 2021

Carbon, nitrogen, and oxygen are the fourth, sixth, and third most abundant elements in the Sun. Their abundances remain hotly debated due to the so-called solar modelling problem that has persisted for almost 20 years. We revisit this issue by presenting a homogeneous analysis of 408 molecular lines across 12 diagnostic groups, observed in the solar intensity spectrum. Using a realistic 3D radiative-hydrodynamic model solar photosphere and local thermodynamic equilibrium (LTE) line formation, we find log ϵC = 8.47  ±  0.02, log ϵN = 7.89  ±  0.04, and log ϵO = 8.70  ±  0.04. The stipulated uncertainties mainly reflect the sensitivity of the results to the model atmosphere; this sensitivity is correlated between the different diagnostic groups, which all agree with the mean result to within 0.03 dex. For carbon and oxygen, the molecular results are in excellent agreement with our 3D non-LTE analyses of atomic lines. For nitrogen, however, the molecular indicators give a 0.12 dex larger abundance than the atomic indicators, and our best estimate of the solar nitrogen abundance is given by the mean: 7.83 dex. The solar oxygen abundance advocated here is close to our earlier determination of 8.69 dex, and so the present results do not significantly alleviate the solar modelling problem.
Efficacy and safety of cap-assisted endoscopic mucosal resection for treatment of nonlifting colorectal polyps
Authors: Van der Voort Veronique R. H. , Moons Leon M. G. , de Graaf Wilmar , Schrauwen Ruud W. M. , Hazen Wouter L. , Seerden Tom C. J. , Vleggaar Frank P. , Didden Paul
Published: September 2021

Background Suboptimal lifting increases complexity of endoscopic mucosal resection (EMR) for benign colorectal polyps. Cap-assisted EMR (EMR-C) may allow fibrotic polyp tissue to be captured in the snare. This study evaluated the efficacy and safety of EMR-C for benign nonlifting colorectal polyps.

Methods This was a multicenter study, which prospectively registered all EMR-C procedures (2016–2018) for presumed benign nonlifting colorectal polyps.

Results 70 nonlifting polyps with a median size of 25 mm (interquartile range [IQR] 15–40) were treated with EMR-C. Complete polyp removal was achieved in 68 (97.1 %), including 47 (67.1 %) with EMR-C alone. Overall, 66 polyps showed benign histology, and endoscopic follow-up after a median of 6 months (IQR 6–10) showed recurrence in 19.7 %. First (n = 10) and second (n = 2) benign recurrences were all treated endoscopically. Deep mural injury type III–V occurred in 7.4 % and was treated successfully with clips.

Conclusion EMR-C may be an alternative therapeutic option for removal of benign nonlifting polyp tissue. Although recurrence still occurs, repeat endoscopic therapy usually leads to complete polyp clearance.
A New Tool to Assess Quality of Life in Patients with Idiopathic Pulmonary Fibrosis or Non-specific Interstitial Pneumonia
Authors: Kirsten Detlef , de Vries Ulrike , Costabel Ulrich , Koschel Dirk , Bonella Francesco , Günther Andreas , Behr Jürgen , Claussen Martin , Schwarz Stefan , Prasse Antje , Kreuter Michael
Published: September 2021

Background Quality of life (QoL) is significantly impaired in patients with pulmonary fibrosis, however reliable tools to assess QoL issues specific for this group of patients are still missing. We thus aimed to develop a new questionnaire called “Quality of life in patients with idiopathic pulmonary fibrosis” (QPF) to measure QoL in patients with fibrotic idiopathic interstitial pneumonias (IIP).

Methods An item pool was created on the basis of a German expert group with support of patients suffering from pulmonary fibrosis. In a 1st step, this version of the questionnaire was completed by 52 patients with idiopathic pulmonary fibrosis (IPF) or non-specific interstitial pneumonia (NSIP). Following this, an item- and an exploratory factor analysis was carried out and a 2nd version created. In a multicenter validation study in a one-group pre-post design, the questionnaire was filled in by 200 patients with IIP (IPF = 190, iNSIP = 10) at 2 time points with an interval of 6 months. Cross-validation was carried out with the St. Georges Respiratory Questionnaire (SGRQ).

Results The mean age of the patients was 71.0 years (50–90 years), 82.5 % were male. Item analysis revealed that most of Cronbach alpha and selectivity values of QPF-scales could be considered as sufficient (e. g. QPF-scale “condition” [alpha = 0.827], “impairment” [alpha = 0.882]). At scale level, there were significant differences in terms of a deterioration or improvement in the QPF-condition and QPF-breathlessness scales and also in the SGRQ-activity scale. Analysis of construct validation of QPF and SGRQ showed moderate correlations between both questionnaires. A deterioration in health status from the patient’s and doctorʼs perspective was seen in the scales “impairment”, “shortness of breath” and “health status” of the QPF. The QPF was able to detect a change in the patientʼs mood (“condition” scale) in the course of treatment.

Conclusion This newly developed questionnaire maps the special needs of the patients well. The QPF is suitable for screening of quality of life as well as for supplementing the medical history and for monitoring the course of disease in fibrotic IIPs.
Oxalylacetylenes as Dielectrophiles for Annulation of Quinoline Rings: Synthesis of Highly Functionalized 1,3-Oxazinoquinolines
Authors: Trofimov Boris A. , Belyaeva Kseniya V. , Nikitina Lina P. , Gen’ Veronika S. , Afonin Andrei V.
Published: September 2021

Oxalylacetylenes act as dielectrophiles in the annulation of quinolines to give highly functionalized 1,3-oxazine cycles decorated with ethynyl, oxalyl, ester and aryl substituents. The annulation proceeds under mild conditions (room temperature, without catalyst) in 2:1 mode with respect to acetylene and quinoline to deliver 1,3-oxazinoquinolines in 45–88% yields. A beneficial feature of the reaction is that, in contrast to results on the reaction of quinolines with trifluoroacetylacetylenes in the presence of water, where H2O acted as a third electrophile, leading to the 1,3-oxazinoquinolines containing a hydroxyl group, this reaction well tolerates the aqueous medium. This reaction also tolerates isoquinoline and phenanthridine.
Prospective Comparative Observational Study of Safety and Efficacy of Topical Ozone Gas Therapy in Healing of Diabetic Foot Ulcers versus Only Conventional Wound Management
Authors: Dhamnaskar Suchin , Gobbur Nishant , Koranne Mandar , Vasa Dhaval
Published: September 2021

The prevalence of diabetic foot ulcers (DFUs) in India is 11.6%. DFU accounts for major cost expenditure, morbidity, and mortality.1 Ozone gas has antimicrobial and antioxidant properties. We studied efficacy of topical ozone gas therapy in promoting healing of DFU. This is an observational comparative cohort study, n = 160, There were two groups of patients namely: those who received Conventional wound management alone C and those who received topical ozone therapy in addition to conventional wound management O + C therapy groups (81 each). Study group, i.e., O + C received five alternate day sessions of ozone therapy by bagging method for 30 minutes each session. Both groups were observed for 30 days for wound healing parameters like reduction of wound surface area, wound diameter, presence and character of discharge, granulation tissue, healing wound edges, microbial negativity, and requirement of revision (re-debridement and/or amputation) surgery. Mean baseline ulcer surface area is 17.43 ± 8.6 cm2 for C and 17.87 ± 9.2 cm2 (range 1–50 cm2) in O + C group. Percentage change in ulcer surface after 21 days in O + C group is 32.37% compared with 17.15% in C group, which is statistically significant (p = 0.01). Rates of microbial negativity and ulcer healing were significantly faster in ozone group. There was a statistically significant decrease in hospital stay, number of revision surgeries required, and mortality in ozone group. Topical ozone gas was well tolerated. Our study supports the efficacy of ozone therapy in DFU healing and reduction in the chances of infection and revision (re-debridement and/or amputation) surgery. More research is needed for dose, duration, and exposure time standardization.
Multiple Grafting with Single Left Internal Mammary Artery as T-Graft with Itself
Authors: Rustenbach Christian Jörg , Djordjevic Ilija , Gerfer Stephen , Ivanov Borko , Gaisendrees Christopher , Eghbalzadeh Kaveh , Wahlers Thorsten
Published: September 2021

Background Revascularization strategies might be limited in patients with lack of sufficient bypass graft material and increased risk of wound healing disturbances. In this regard, we present first results of patients treated with left internal mammary artery (LIMA) as T-graft with itself due to left-sided double-vessel disease, elevated risk of wound healing infection, and lack of graft material.

Methods Eighteen patients were retrospectively analyzed in this study. All patients received LIMA grafting, and additional T-graft with itself during off-pump coronary artery bypass surgery. The investigation was focused on intraoperative and postoperative outcomes.

Results LIMA-LIMA T-graft was performed in a total of 18 patients. Mean Fowler score accounted for 18.2 ± 2.9. Severe vein varicosis was present in 9 patients, and 38.9% of patients had lacking venous graft material due to prior vein stripping. A total of 2.5 ± 0.5 distal anastomoses were performed. Mean flow of LIMA—left anterior descending anastomosis was 41.72 ± 12.11 mL/min with a mean pulsatility index (PI) of 1.01 ± 0.21. Mean flow of subsequent T-graft accounted for 26.31 ± 4.22 mL/min with a mean PI of 1.59 ± 0.47. Median hospital stay was 7(6.75;8) days. No incidence of postoperative wound healing disorders was observed and all patients were discharged off hospital.

Conclusions LIMA as T-graft with itself to treat left-sided double-vessel disease is feasible and safe in patients with missing bypass graft material and increased risk of deep sternal wound infection. Further prospective studies are necessary to confirm our results.
Methodological Considerations in the Assessment of Effectiveness of Homeopathic Care: A Critical Review of the EPI3 Study
Authors: Moride Yola
Published: September 2021

Background  EPI3 is an observational study of a representative sample of general practitioners (GPs) and patients in France, demonstrating that patient characteristics differ according to the prescribing preferences of their GPs for homeopathy. For selected conditions (musculoskeletal disorders, sleep disorders, anxiety/depression, upper respiratory tract infections), progression of symptoms and adverse events over follow-up in the homeopathy preference group did not significantly differ from other practice preferences, but there was a two-fold to four-fold lower usage of conventional medicines. The EPI3 study's validity was challenged due to absence of head-to-head comparison of medicines to conclude on a causal association between homeopathy and outcomes.

Methods A critical review of the nine EPI3 publications was conducted, focusing on generalizability, selection bias, outcome measurements and confounding.

Results The conceptual framework of EPI3 rests on a systemic construct, i.e., the homeopathic treatment concept assessed using the type of GP prescribing preference, taking into account the clinical, human and social aspects. The enrollment process enhanced the generalizability of findings. Validated instruments for outcome measurements were used for three conditions, and control of confounding was rigorous.

Conclusion EPI3 was conducted according to best practices. Homeopathy prescribing preference met specific patient needs with less use of conventional medicines and without an apparent loss in therapeutic opportunity.
The Achilles Tendon Rupture in Basketball: Systematic Review of the Present Literature
Authors: Alegre Berta , Seijas Roberto , Alvarez Pedro , Pérez Albert
Published: September 2021

Background The most common cause of the Achilles tendon ruptures in the U.S. population is sports, basketball is one among them. It is not one of the most frequent injuries of this sport, but it is one of the most serious and impactful in its practice.

Purpose The objective of this work is to gather evidence and evaluate the relationship between Achilles' tendon ruptures and basketball.

Study Design This study designed as a systematic review.

Material and Methods A search of literature in the databases PubMed, Cochrane Library, and ClinicalTrials.gov was conducted during January and February 2020.

Results After the search and selection, three relevant articles were obtained due to their epidemiological content, Raikin et al and Lemme et al. In 2013 and 2018, they, respectively, conducted studies in U.S. populations, establishing sport as the most frequent injury mechanism in Achilles' tendon ruptures. It was analyzed according to injury mechanism, gender, body mass index (BMI), and age. In both studies, the lesion resulted more frequently in men and the sport involved in most of the cases was basketball (32 and 42.6%, respectively). In 2019, Lemme et al published an epidemiological design analyzing the Achilles tendon ruptures in the National Basketball Association (NBA), identifying risk factors and results in professional players. After suffering the injury, 36.8% of the patients had to retire or were holders in less than 10 games to the rest of their sports career.

Conclusions The relationship between basketball and Achilles' tendon rupture is clear in the general population. Despite this, new studies are required to complement the evidence obtained so far.
A Meta-analysis of Transanal Endoscopic Microsurgery versus Total Mesorectal Excision in the Treatment of Rectal Cancer
Authors: Ahmad Nasir Zaheer , Abbas Muhammad Hasan , Abunada Mohamed H. , Parvaiz Amjad
Published: September 2021

Background Transanal endoscopic microsurgery (TEMS) has been suggested as an alternative to total mesorectal excision (TME) in the treatment of early rectal cancers. The extended role of TEMS for higher stage rectal cancers after neoadjuvant therapy is also experimented. The aim of this meta-analysis was to compare the oncological outcomes and report on the evidence-based clinical supremacy of either technique.

Methods Medline, Embase, and Cochrane databases were searched for the randomized controlled trials comparing the oncological and perioperative outcomes of TEMS and a radical TME. A local recurrence and postoperative complications were analyzed as primary end points. Intraoperative blood loss, operation time, and duration of hospital stay were compared as secondary end points.

Results There was no statistical difference in the local recurrence or postoperative complications with a risk ratio of 1.898 and 0.753 and p-values of 0.296 and 0.306, respectively, for TEMS and TME. A marked statistical significance in favor of TEMS was observed for secondary end points. There was standard difference in means of −4.697, −6.940, and −5.685 with p-values of 0.001, 0.005, and 0.001 for blood loss, operation time, and hospital stay, respectively.

Conclusion TEMS procedure is a viable alternative to TME in the treatment of early rectal cancers. An extended role of TEMS after neoadjuvant therapy may also be offered to a selected group of patients. TME surgery remains the standard of care in more advanced rectal cancers.
Fractured T Tube Fragment in Common Bile Duct during Retrieval: An Unforeseen Mishap
Authors: Rajput Deepak , Patnaik Itish , Shasheendran Sruthi , Kumar Beeram K. Prasanna , Gupta Amit
Published: September 2021

Common bile duct (CBD) exploration by surgical method—open or laparoscopic, traditionally involved using a T tube to take care of postoperative intraluminal pressure and edema. The complications of T tube include bile leak after removal, formation of biliary fistula, excoriation of the skin, dehydration, saline depletion, retained T tube fragment, CBD obstruction, cholangitis, pancreatitis, and duodenal erosion. Here, we report a case of retained T tube fragment after an attempted removal in an operated case of choledocholithiasis, which was managed by endoscopic retrograde cholangiopancreatography and balloon catheter removal of the remnant.
Salvage of a Near-Total Penile Amputation following Urinary Fistulization and Carbapenemase-Producing Klebsiella pneumoniae Infection with a Composite ALT Flap and Vascularized Fascia Lata
Authors: Horta Ricardo , Mendes Margarida , Barreiro Diogo , Almeida Alexandre , Jarnalo Mariana , Teixeira Sérgio , Pinto Rui
Published: September 2021

Reconstruction of complex penile defects is always challenging, as some defects are not possible to reconstruct with skin or mucosa grafts, and even local flaps may be precluded in complex wounds. We present a case of a 63-year-old otherwise healthy man, who underwent transurethral resection of the prostate for benign prostatic hyperplasia. After the procedure, he developed panurethral necrosis with consequent stricture. Three urethroplasties for reconstruction of the bulbar and distal urethra using buccal mucosa grafts, a preputial flap, and penile skin were performed by urology team in different institutions, but serious urinary fistulization and carbapenemase-producing Klebsiella pneumoniae (KPC) infection translated in a chronic wound, urethra necrosis, and near-total penile amputation. A composite anterolateral thigh flap and vascularized fascia lata were used with success together with a perineal urethroplasty in different stages, improving the ischemic wound condition. The extended segment of fascia lata was used for Buck's fascia replacement and circumferential reinforcement to cover the erectile bodies of the penis. The postoperative period was uneventful and after 12 months, there were no signs of recurrence or wound dehiscence. He was able and easily adapted to void in a seated position through the perineal urethrostomy that was made. To the best of our knowledge, this procedure has not been reported previously as a salvage procedure in a fistulizated and KPC infected penis, but it may be considered to avoid penile amputation in chronic infected and intractable wounds.
Can robots possess knowledge? Rethinking the DIK(W) pyramid through the lens of employees of an automotive factory
Authors: Hautala Johanna
Published: September 2021

Knowledge, information, and data are increasingly processed in human–robot collaboration. This study tackles two requirements for revising the concepts of knowledge, information, and data. First is developing robots’ knowledge capabilities and transparency and ensuring effective division of tasks between humans and robots to increase the productivity of robotised factories. Employees’ interpretations of robots’ abilities to possess knowledge reveal their assumptions of robots’ possibilities and limitations to create knowledge-based products with humans. Second, the classic DIK(W) pyramid of data, information, knowledge, and wisdom is a theoretical construct requiring additional empirical research. This empirical exploratory study develops the DIK(W) further and applies it as a tool to understand employees’ perspectives of robots and knowledge. Do people believe robots possess knowledge? What kind of knowledge can (or cannot) robots possess? A survey (n = 269) was collected from the most robotised factory in Finland, Valmet Automotive. Half of the respondents think robots can possess knowledge, but only with humans. These respondents were more likely to trust robots compared to those who think robots cannot possess knowledge. As the key contribution, the DIK(W) pyramid is reconceived by (i) acknowledging robots and humans, (ii) turning the pyramid upside down, and (iii) recognising knowledge as a dividing concept.
Coating titanium oxide nanorods with barium strontium titanate shells boosts water splitting
Authors: Liebendorfer Adam
Published: September 2021

The proposed mechanism draws on ferroelectric instability to protect against adverse recombinations and opens avenues of research in the role of polarons.
Exponential stability of impulsive fractional neutral stochastic differential equations
Authors: Dhanalakshmi K. , Balasubramaniam P.
Published: September 2021

In this paper, we investigate the existence of a mild solution and exponential stability for a class of second-order impulsive fractional neutral stochastic differential equations (IFNSDEs) driven by fractional Brownian motion in a real and separable Hilbert space together with the semigroup of a bounded linear operator and stochastic settings. Some meaningful sufficient conditions are derived, which generalize and enhance some existing results. Finally, to show the efficacy of our results, a numerical example is provided.
An 18.3 MJ charging and discharging pulsed power supply system for the Space Plasma Environment Research Facility (SPERF): The subsystem for the magnetic perturbation coils
Authors: Guan Jian , E Peng , Mao Aohua , Ma Xun , Jin Chenggang , Deng Weijun , Ding Mingjun , Li Songjie , Kang Chuanhui , Xiao Jinshui , Tong Weiming , Li Hongtao
Published: September 2021

The mechanism of acceleration, loss, and wave–particle interaction of energetic particles in the magnetosphere is a research content of the Space Plasma Environment Research Facility, which is being built as a user facility at the Harbin Institute of Technology in China. Two magnetic perturbation coils are used to simulate the magnetic storm distortion and excite Alfvén wave perturbation. A capacitor-based pulsed power supply (PPS) system with a modular design is developed to excite the magnetic perturbation coils to generate the required amplitude and duration of the magnetic field. The two magnetic perturbation coils are the CRDI coil and CRDII coil and are excited by one set of PPSs. The PPS for the CRDI coil consists of two modules and can provide a pulsed current of no less than 132 kA at 0.12 ms when the charging voltage is 20 kV, and the duration of the pulsed current from the peak to 10% of the peak is no more than 0.7 ms. The PPS for the CRDII coil consists of five modules and can provide a pulsed current of no less than 16 kA at 0.45, 0.65, 0.8, 0.95, and 1.1 ms, and the duration of the pulsed current from the peak to 10% of the peak is no more than 4.5 ms. The detailed design of the PPSs has been discussed in this paper, and the discharge test of the PPSs is carried out to verify the design of the PPSs.
Conductance fluctuations in hydrogenated amorphous germanium
Authors: Knauber Brenda J. , Eslamisaray Mohammad Ali , Kakalios J.
Published: September 2021

Measurements of conductance fluctuations in undoped hydrogenated amorphous germanium (a-Ge:H) find power spectra that vary with inverse frequency (1/f) that are characterized by non-Gaussian statistics. The non-Gaussian aspect of the 1/f noise is reflected in (1) histograms of the noise power per octave that are described by lognormal distributions, (2) power-law second spectra, and (3) strong correlations of the noise power in frequency-space. In contrast, measurements of current fluctuations in polycrystalline germanium thin films find 1/f noise with Gaussian statistics. These results are discussed in terms of a model of filamentary conduction, where the filament structure and conductance in a-Ge:H are modulated by hydrogen motion.
Bifurcation of singularities of fluctuational paths for a noise-driven overdamped two-well system
Authors: Yu Qing , Liu Xianbin
Published: September 2021

Noise-induced escape in a 2D generalized Maier–Stein model with two parameters μ and α is investigated in the weak noise limit. With the WKB approximation, the patterns of extreme paths and singularities are displayed. By employing the Freidlin–Wentzell action functional and the asymptotic series, critical parameters α inducing singularity bifurcation are determined analytically for μ=1. The switching line will appear with singularities and is equivalent to the sliding set in the Filippov system. The pseudo-saddle-node bifurcation on the switching line is found. Then, when −1<μ<1, it is found that all bifurcation values α will decrease as μ decreases and the second-order bifurcation values are bigger than all first-order ones. In addition, the variation of the switching line is also analyzed and a new switching line will emerge when the location of the minimum quasi-potential on the boundary changes. At last, when the noise is anisotropic, only the noise intensity ratio will affect the bifurcation value α.
High-power, fiber–laser-based source for magic-wavelength trapping in neutral-atom optical clocks
Authors: Eckner William J. , Young Aaron W. , Schine Nathan , Kaufman Adam M.
Published: September 2021

We present a continuous-wave, 810 nm laser with watt-level powers. Our system is based on difference-frequency generation of 532 and 1550 nm fiber lasers in a single pass through periodically poled lithium niobate. We measure the broadband spectral noise and relative intensity noise to be compatible with off-resonant dipole trapping of ultracold atoms. Given the large bandwidth of the fiber amplifiers, the output can be optimized for a range of wavelengths, including the strontium clock-magic-wavelength of 813 nm. Furthermore, with the exploration of more appropriate nonlinear crystals, we believe that there is a path toward scaling this proof-of-principle design to many watts of power and that this approach could provide a robust, rack-mountable trapping laser for future use in strontium-based optical clocks.
Water evaporation from solute-containing aerosol droplets: Effects of internal concentration and diffusivity profiles and onset of crust formation
Authors: Rezaei Majid , Netz Roland R.
Published: September 2021

The evaporation of droplets is an important process not only in industrial and scientific applications, but also in the airborne transmission of viruses and other infectious agents. We derive analytical and semi-analytical solutions of the coupled heat and mass diffusion equations within a spherical droplet and in the ambient vapor phase that describe the evaporation process of aqueous free droplets containing nonvolatile solutes. Our results demonstrate that the solute-induced water vapor-pressure reduction considerably slows down the evaporation process and dominates the solute-concentration dependence of the droplet evaporation time. The evaporation-induced enhanced solute concentration near the droplet surface, which is accounted for using a two-stage evaporation description, is found to further slow-down the drying process. On the other hand, the presence of solutes is found to produce a lower limit for the droplet size that can be reached by evaporation and, also, to reduce evaporation cooling of the droplet, which tend to decrease the evaporation time. Overall, the first two effects are dominant, meaning that the droplet evaporation time increases in the presence of solutes. Local variation of the water diffusivity inside the droplet near its surface, which is a consequence of the solute-concentration dependence of the diffusion coefficient, does not significantly change the evaporation time. Crust formation on the droplet surface increases the final equilibrium size of the droplet by producing a hollow spherical particle, the outer radius of which is determined as well.
Enhanced red emission from Eu-implanted ZnMgO layers and ZnO/ZnMgO quantum structures
Authors: Kozanecki A. , Sajkowski J. M. , Mathew J. A. , Zhydachevskyy Y. , Alves E. , Stachowicz M.
Published: September 2021

Photoluminescence (PL) of Eu3+ ions in single layers of ZnO and ZnMgO and in short-period ZnO/ZnMgO and ZnO/MgO superlattices (SLs) grown by molecular beam epitaxy was investigated, and the results have been presented. Single ZnO and ZnMgO layers were grown on GaN/sapphire substrates, whereas the SLs on c-oriented crystalline ZnO. All samples were implanted with 300 keV Eu ions, and then rapid thermal annealing was performed at 800 °C for 5 min in an oxygen atmosphere to activate the intra-4f-shell PL of Eu3+ ions. After annealing, the red emission due to the 5D0 → 7F2 radiative transitions of Eu3+ was observed at excitation above the energy gap. The results clearly show that Mg is essential for obtaining the high 4f–4f PL intensity of Eu3+ ions, as in ZnMgO layers and short period SLs, the red emission is several times more intense than in ZnO. The PL excitation spectra were examined to confirm the energy transfer from the bandgap to the Eu3+ ions. Clear evidence is presented that in the studied short period SLs, the excitation of the Eu3+ PL occurs via generation of excitons in the barrier layers.
Reconfigurable acoustic multiplexer/demultiplexer using time division
Authors: Darabi Amir , Kliewer Emily , Leamy Michael J.
Published: September 2021

Implementing guided-wave technologies in mechanical systems has always been a significant challenge due to losses associated with defects and sharp angles. Inspired by quantum Hall effects in condensed matter physics, mechanical topological insulators (TIs) have recently addressed these issues using efficient and robust signal transport supported by backscattering-immune topological protection. In this Letter, we demonstrate the first mechanical TI-based multiplexer/demultiplexer using acoustic waves. Triangular arrays of circular piezoelectric disks bonded to an aluminum host medium, shunted through external circuits with equivalent negative capacitance, break inversion symmetry and create topologically protected interface states. Combined with programmable switches, the device enables acoustic waves to travel efficiently from an input source to multiple output receivers, or vice versa, via dynamic topological interfaces. The proposed acoustic multiplexer/demultiplexer is envisioned to find application in wave-based devices, as an accompaniment to ubiquitous surface acoustic wave filtering used in communication devices, such as cell phones, radios, and computer peripherals.
CORE-MD II: A fast, adaptive, and accurate enhanced sampling method
Authors: Peter Emanuel K. , Manstein Dietmar J. , Shea Joan-Emma , Schug Alexander
Published: September 2021

In this paper, we present a fast and adaptive correlation guided enhanced sampling method (CORE-MD II). The CORE-MD II technique relies, in part, on partitioning of the entire pathway into short trajectories that we refer to as instances. The sampling within each instance is accelerated by adaptive path-dependent metadynamics simulations. The second part of this approach involves kinetic Monte Carlo (kMC) sampling between the different states that have been accessed during each instance. Through the combination of the partition of the total simulation into short non-equilibrium simulations and the kMC sampling, the CORE-MD II method is capable of sampling protein folding without any a priori definitions of reaction pathways and additional parameters. In the validation simulations, we applied the CORE-MD II on the dialanine peptide and the folding of two peptides: TrpCage and TrpZip2. In a comparison with long time equilibrium Molecular Dynamics (MD), 1 µs replica exchange MD (REMD), and CORE-MD I simulations, we find that the level of convergence of the CORE-MD II method is improved by a factor of 8.8, while the CORE-MD II method reaches acceleration factors of ∼120. In the CORE-MD II simulation of TrpZip2, we observe the formation of the native state in contrast to the REMD and the CORE-MD I simulations. The method is broadly applicable for MD simulations and is not restricted to simulations of protein folding or even biomolecules but also applicable to simulations of protein aggregation, protein signaling, or even materials science simulations.
Prediction on the theoretical strength of diamond, c-BN, Cu, and CeO2
Authors: Liu Zhao , Wang Biao
Published: September 2021

The theoretical (ideal) strength is the upper strength limit that any solid can withstand. Estimation of the theoretical strength of materials is vital for their applications. In the materials science field, the Griffith theory is the most widely used criterion for estimating the theoretical strength of materials, which sets an upper bound strength of ∼E/9. In addition, Frenkel and Orowan–Polanyi’s derivation from the force–displacement relationship using the sinusoidal correlation also gives a similar value of ∼E/10. Recently, with the improved quality of fabricated samples, people have reported the possibility of reaching or exceeding the theoretical strength. In this work, first-principles calculations based on density functional theory (DFT) are used to study the theoretical strength of four representative materials (diamond, c-BN, Cu, and CeO2) under uniaxial tensile loading along the low-index crystallographic directions. The results demonstrate that the theoretical strength of materials exhibits strong anisotropy. It is found that the ideal strength calculated by DFT is larger than the ideal strength predicted by Griffith theory or the approximate value of E/10 in all the four materials along some specific directions. This discrepancy is explained by the analysis of the fracture mechanism. In addition, based on the stability analysis of thermodynamical systems, the strength criterion based on the energy–strain relation was established, which is verified by the DFT results.
Deformation quantization of moduli spaces of Higgs bundles on a Riemann surface with translation structure
Authors: Biswas Indranil
Published: September 2021

Let X be a compact connected Riemann surface of genus g ≥ 1 equipped with a nonzero holomorphic 1-form. Let MX(r) denote the moduli space of semistable Higgs bundles on X of rank r and degree r(g − 1) + 1; it is a complex symplectic manifold. Using the translation structure on the open subset of X where the 1-form does not vanish, we construct a natural deformation quantization of a certain nonempty Zariski open subset of MX(r).
Trends in sightings of the stingrays of southern Mozambique
Authors: Keeping Jennifer , Milligan Rosanna J. , Reeve-Arnold Katie , Bailey David
Published: September 2021

Understanding the drivers that influence abundance and distribution of marine species is essential to predict future trends in abundance and inform conservation efforts. This is vital in the largely unregulated coastline of Mozambique, where stingrays are afforded no protection by law and are caught by small-scale fishers. During SCUBA dives from 2012 to 2018, trained citizen scientists recorded 11 environmental, spatial and temporal variables along with the count of four stingray species (Megatrygon microps, Taeniurops meyeni, Neotrygon indica and Pateobatis jenkinsii) in the Inhambane region of Mozambique. By constructing bubble plots and generalised additive mixed models (GAMMs), we analysed the relationship between the probability of sightings of each species with the 11 variables. It is evident that the sightings for each of these four stingrays of the Inhambane region differ spatially and seasonally. The key findings include that T. meyeni and M. microps were found to increase in sighting frequency in different seasons (winter and summer respectively) at similar dive sites typically further from shore. Neotrygon indica commonly occupied the areas closer to shore. Identifying key habitats, and temporal and environmental conditions, is conducive to implementing effective conservation strategies in the region, such as, in this instance, all stingrays could be provided with a refuge in the same area.
Defects in 8-oxo-guanine repair pathway cause high frequency of C > A substitutions in neuroblastoma
Authors: van den Boogaard Marlinde L. , Oka Rurika , Hakkert Anne , Schild Linda , Ebus Marli E. , van Gerven Michael R. , Zwijnenburg Danny A. , Molenaar Piet , Hoyng Lieke L. , Dolman M. Emmy M. , Essing Anke H. W. , Koopmans Bianca , Helleday Thomas , Drost Jarno , van Boxtel Ruben , Versteeg Rogier , Koster Jan , Molenaar Jan J.
Published: September 2021

Significance

The collection of large amounts of whole-genome sequencing data allowed for identification of mutational signatures, which are characteristic combinations of substitutions in the context of neighboring bases. The clinical significance of these mutational signatures is still largely unknown. In neuroblastoma, we showed that high levels of cytosine > adenine (C > A) substitutions are associated with poor survival. We identified that these high levels of C > A substitutions result from defects in 8-oxo-guanine repair, specifically from copy number loss of the DNA glycosylases
MUTYH
and
OGG1
. The high frequency of C > A substitutions in neuroblastoma contributes to the increased adaptive capacity of these tumors. Thereby, we link basic molecular genetic mutation patterns to clinically significant tumor evolution processes.
Distinct roles of nuclear basket proteins in directing the passage of mRNA through the nuclear pore
Authors: Li Yichen , Aksenova Vasilisa , Tingey Mark , Yu Jingjie , Ma Ping , Arnaoutov Alexei , Chen Shane , Dasso Mary , Yang Weidong
Published: September 2021

Significance

The nuclear pore complex (NPC) consisting of hundreds of proteins embeds into the nuclear envelope and functions as a selectively permeable barrier regulating the bidirectional trafficking of macromolecules between the nucleoplasm and cytoplasm in eukaryotic cells. However, the exact copy number and the specific function of each composite protein within the NPC remain vague. To interrogate this gap in knowledge, in this paper, we utilized a high-speed single-molecule microscopy in conjunction with highly specific auxin-inducible degron strategies to detail the stoichiometric ratio of NPC’s nuclear basket proteins and also reveal their distinct roles in mediating nuclear export of messenger RNAs. The demonstrated techniques might also serve as an effective model for characterizing other large macromolecule complexes.
Chronic UV radiation–induced RORγt+ IL-22–producing lymphoid cells are associated with mutant KC clonal expansion
Authors: Lewis Julia M. , Monico Patrick F. , Mirza Fatima N. , Xu Suzanne , Yumeen Sara , Turban Jack L. , Galan Anjela , Girardi Michael
Published: September 2021

Significance

Ultraviolet (UV) exposure from the sun is the greatest risk factor for skin cancer. Toward preventive strategies, we elucidated the immune pathways critical to skin cancer development and identified specific cells and signals associated with mutated skin cell growth. UV light and Langerhans cells cooperate to induce lymphoid cells that produce interleukin-22 locally and are associated with mutant skin cell growth. This effect is highly dependent on the differentiation factor RORγt that can be inhibited with a topical agent. Such skin cancer–supporting immune cells were identified with distinctive markers: RORγt+ Sca-1+ CD103+ ICOS+ CD2+/−CCR6+ intracellular CD3+. Together, these data elucidate key immune components of UV-induced skin cancer that may represent targets for skin cancer prevention.
FGF-2–dependent signaling activated in aged human skeletal muscle promotes intramuscular adipogenesis
Authors: Mathes Sebastian , Fahrner Alexandra , Ghoshdastider Umesh , Rüdiger Hannes A. , Leunig Michael , Wolfrum Christian , Krützfeldt Jan
Published: September 2021

Significance

A unique feature of muscle during aging, obesity, and type 2 diabetes is the appearance of adipose tissue between skeletal muscle fibers, the intramuscular adipose tissue (IMAT). IMAT is generally associated with insulin resistance, decreased muscle strength, and, in older adults, impaired mobility. However, the molecular cues that cause the pathological formation of IMAT are currently unknown. This work uncovers a conserved FGF-2–mediated signaling axis that up-regulates the expression of microRNA-29a, triggering a decrease of the adipogenic inhibitor SPARC and increased fat formation in aged skeletal muscle. We show that FGF-2–dependent signaling modulates the fate of fibro/adipogenic progenitors and their propensity to differentiate to intramuscular adipocytes, which reveal therapeutic opportunities to prevent IMAT formation in human skeletal muscle.
Influenza A viruses balance ER stress with host protein synthesis shutoff
Authors: Mazel-Sanchez Beryl , Iwaszkiewicz Justyna , Bonifacio Joao P. P. , Silva Filo , Niu Chengyue , Strohmeier Shirin , Eletto Davide , Krammer Florian , Tan Gene , Zoete Vincent , Hale Benjamin G. , Schmolke Mirco
Published: September 2021

Significance

As intracellular parasites, viruses depend on the host cell machinery to produce and fold viral proteins. Because the capacity to fold proteins is limited, excessive viral translation of glycoproteins leads to ER stress. Unresolved ER stress drives host cells into apoptosis. We identify the expression of neuraminidase as the molecular source of influenza A virus–induced ER stress. The virus naturally balances it by the limitation of host protein production through the viral host shutoff protein NS1. The host cell mounts an unfolded protein response, creating additional protein folding reserves. Ultimately, the virus uses the stress-induced protein production capacities of the host cell to its own replication advantage.
The neural basis for violations of Weber’s law in self-motion perception
Authors: Carriot Jerome , Cullen Kathleen E. , Chacron Maurice J.
Published: September 2021

Significance

An unanswered question is why perceptual performance consistently exceeds that predicted from Weber’s law across sensory modalities. Here, we provide a neural basis for such violations of Weber’s law. Specifically, we demonstrate that the structure of variability in vestibular thalamocortical neurons gives rise to the improvement in neural discrimination performance required to explain previous perceptual results. Our results not only have important consequences for understanding how sensory pathways generate perception but also provide an unexpected function for neural variability. Moreover, our findings make an important contribution by suggesting that improved perceptual discrimination performance observed across modalities is a signature of optimized coding in the brain when neural variability is taken into account.
Lipids modulate the BH3-independent membrane targeting and activation of BAX and Bcl-xL
Authors: Vasquez-Montes Victor , Rodnin Mykola V. , Kyrychenko Alexander , Ladokhin Alexey S.
Published: September 2021

Significance

Here, we characterize a mechanism that modulates the membrane targeting, refolding, and activation of the apoptotic regulators BAX and Bcl-xL in the absence of their canonical activators (BH3-only effector proteins). The critical component of the suggested mechanism is the enrichment of the mitochondrial outer membrane with anionic lipids, primarily cardiolipin. This lipid-dependent activation is found to be coupled to the presence of physiologically relevant concentrations of divalent cations. Membrane insertion of Bcl-xL results in the release of the BH4 regulatory domain from the folded structure, leading to inhibition of pore formation by BAX. These results provide a mechanistic rationale for recent cellular studies that demonstrate the mitochondrial localization and activity of BAX and Bcl-xL in cells lacking BH3-only effectors.
Strategic basin and delta planning increases the resilience of the Mekong Delta under future uncertainty
Authors: Schmitt R. J. P. , Giuliani M. , Bizzi S. , Kondolf G. M. , Daily G. C. , Castelletti Andrea
Published: September 2021

Significance

Globally, river deltas, which support some of the planet’s most productive agroeconomic systems and half a billion livelihoods, are at risk of being drowned by rising sea levels and accelerated subsidence. Whether delta land falls below sea level will depend on land and water management in the delta, sediment supply from the upstream basin, and global climate change. Those drivers cover multiple scales and domains and are rapidly changing, uncertain, and interconnected, which makes finding robust strategies to increase the resilience of river deltas challenging. Herein, we demonstrate an approach to identify planning levers that can increase the resilience of river deltas under a wide range of future conditions for the 40,000-km
2
Mekong Delta in Southeast Asia.
Self-mediated positive selection of T cells sets an obstacle to the recognition of nonself
Authors: Koncz Balázs , Balogh Gergő M. , Papp Benjamin T. , Asztalos Leó , Kemény Lajos , Manczinger Máté
Published: September 2021

Significance

It is well established that peptides that are dissimilar to human proteins are more immunogenic. However, the immune system is still unable to recognize a large fraction of highly dissimilar peptides found in a wide variety of pathogens. We propose that this phenomenon could be explained by the mechanism of T cell positive selection. During this process, only those cells survive that recognize human peptides on the surface of thymic epithelial cells. As self-peptides mediate positive selection, the immune system is unable to recognize many nonself peptides, most of which are highly dissimilar to human peptides.