bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Ladle Shroud Design and Mis-alignment Effects on the Fluid Flow in a Metallurgical Tundish- A CFD Model Study
Authors: Chen Lei , Chen Jun-song , Li Yu-qian , Wang She-bin , Chen Chao
Published: September 2020

Two aspects of ladle shroud design in tundish are studied. The two strand tundish is a long and bare tundish i.e. without flow control devices but stopper rods to control flowrate. The 3D CAD geometry, turbulence models, discretisation of governing equations, numerical solution and post processing are performed in a commercial software Siemens STAR CCM+. Compared to the typical pipe ladle shroud, the velocity of impinging stream from the ladle shroud is lower for the trumpet ladle shroud. As a result, the flow stream in the whole tundish shows a contradictory tendency, i.e. the upward stream is more obvious than the downward stream for trumpet shroud and vice visa for pipe shrouds. In industrial production, the ladle shroud often canted to the front wall due to machinery reasons. Therefore, two cases that the misalignment degree of the ladle shroud are 5 and 10 degrees are studied. The results show that the impinging stream flow towards the front side of walls and the flow towards the outlets near the bottom wall and front wall. The horse like vortex that is typically observed in bare tundishes is destroyed. The non-symmetric flow pattern is formed for the severely biased cases which should be paid more attentions from industrial
practice.
Menschen ohne Krankenversicherung – Prävalenz und
Rückführung in die sozialen Sicherungssysteme durch den
Sozialdienst am Beispiel des Universitätsklinikums Essen
Authors: Neupert Ingo , Pieper Claudia
Published: September 2020

Ziel der Studie Trotz der seit 2007 grundsätzlich geltenden
Versicherungspflicht leben in Deutschland Menschen ohne ausreichenden
Krankenversicherungsschutz. Daten zur Prävalenz oder zur Beschreibung
dieser Bevölkerungsgruppe gibt es kaum, vor allem für den
stationären Sektor. Die vorliegende Studie beschreibt deren
Prävalenz und soziodemographische Verteilung am Beispiel des
Universitätsklinikums Essen über einen Zeitraum von fünf
Jahren. Darüber hinaus berichten wir Ergebnisse der
Kostenträgerermittlung und deren monetäre Auswirkungen
für den Leistungserbringer.

Methodik Eingeschlossen wurden Patienten mit fehlendem oder unklarem
Versicherungsstatus der Jahre 2014–2018. Für eine differenzierte
Auswertung wurden vier Statusgruppen gebildet Patienten mit Leistungsanspruch in
Deutschland, EU-Bürger, Patienten aus Drittstaaten und Patienten ohne
Aufenthaltsstatus.

Ergebnisse Die Stichprobe umfasst 918 Patienten ohne
Krankenversicherungsschutz (mittleres Alter 31,3±20,6 Jahre,
52,1% Männer). Für den Fünfjahreszeitraum wurde
in 74% der Fälle ein Kostenträger ermittelt und dadurch
eine Kostenerstattung in Höhe von insgesamt 7,5 Million Euro erreicht.
Die größte Inanspruchnahme zeigt sich in den Fachabteilungen
Frauenheilkunde und Geburtshilfe mit 20%, der Kinderheilkunde mit
17%, der Orthopädie und Unfallchirurgie mit 14% und der
Innere Medizin mit 13%.

Schlussfolgerung Die Studie belegt, dass Menschen ohne
Krankenversicherungsschutz im medizinischen Versorgungssystem nach wie vor
existieren. Für den stationären Sektor zeigen die Ergebnisse,
dass eine Kostenträgerermittlung und Kostenerstattung möglich
sind und sich die Kosten beziffern lassen. Um insgesamt zielgruppenspezifischere
Maßnahmen für die Praxis entwickeln zu können, bedarf es
intensivere Forschungsansätze zu den Ursachen und Einflussfaktoren. Die
Verfügbarkeit flächendeckender Informationen würde die
Thematik der fehlenden Vergütung für diese Patientengruppe
politisch diskutierbar machen.
Der Anteil sexueller Minoritäten in der älteren Wohnbevölkerung in Deutschland und potenzielle Assoziation zwischen der sexuellen Orientierung und depressiven Symptomen
Authors: Buczak-Stec Elżbieta , König Hans-Helmut , Riedel-Heller Steffi G. , Hajek André
Published: September 2020

Ziel der Studie Beschreibung des Anteils sexueller Minoritäten in der älteren Wohnbevölkerung in Deutschland und Darstellung einer möglichen Assoziation mit depressiven Symptomen.

Methodik Daten der sechsten Welle (Jahr 2017) des Deutschen Alterssurveys (n = 5133). Das Durchschnittsalter betrug 66,1 Jahre (43–90 Jahre). Die Allgemeine Depressionsskala (Kurzversion, ADS-K) wurde zur Erfassung depressiver Symptome verwendet. Es wurde zwischen Hetero-, Bi- und Homosexuellen unterschieden. In die Analysen haben wir u. a. die folgenden Kovariaten aufgenommen: Alter, Geschlecht, Partnerschaftsstatus, Wohnort, subjektive Gesundheit, körperliche Funktionsfähigkeit (kurze Skala SF-36).

Ergebnisse In der älteren Wohnbevölkerung in Deutschland identifizieren sich 92,8 % der Individuen als Heterosexuelle, 1,7 % als Bisexuelle, 1,1 % als Homosexuelle und 4,3 % als „Andere“. Bivariat zeigte sich, dass kein signifikanter Zusammenhang zwischen sexueller Orientierung und depressiven Symptomen besteht. In multiplen Regressionsanalysen bestätigte sich dieses Ergebnis.

Schlussfolgerung Unsere Ergebnisse deuten darauf hin, dass kein signifikanter Zusammenhang zwischen der sexuellen Orientierung und depressiven Symptomen in der älteren Wohnbevölkerung in Deutschland besteht.
Mutations in SARS-CoV-2 Leading to Antigenic Variations in Spike Protein: A Challenge in Vaccine Development
Authors: Singh Praveen Kumar , Kulsum Umay , Rufai Syed Beenish , Mudliar S. Rashmi , Singh Sarman
Published: September 2020

Objectives The spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus has been unprecedentedly fast, spreading to more than 180 countries within 3 months with variable severity. One of the major reasons attributed to this variation is genetic mutation. Therefore, we aimed to predict the mutations in the spike protein (S) of the SARS-CoV-2 genomes available worldwide and analyze its impact on the antigenicity.

Materials and Methods Several research groups have generated whole genome sequencing data which are available in the public repositories. A total of 1,604 spike proteins were extracted from 1,325 complete genome and 279 partial spike coding sequences of SARS-CoV-2 available in NCBI till May 1, 2020 and subjected to multiple sequence alignment to find the mutations corresponding to the reported single nucleotide polymorphisms (SNPs) in the genomic study. Further, the antigenicity of the predicted mutations inferred, and the epitopes were superimposed on the structure of the spike protein.

Results The sequence analysis resulted in high SNPs frequency. The significant variations in the predicted epitopes showing high antigenicity were A348V, V367F and A419S in receptor binding domain (RBD). Other mutations observed within RBD exhibiting low antigenicity were T323I, A344S, R408I, G476S, V483A, H519Q, A520S, A522S and K529E. The RBD T323I, A344S, V367F, A419S, A522S and K529E are novel mutations reported first time in this study. Moreover, A930V and D936Y mutations were observed in the heptad repeat domain and one mutation D1168H was noted in heptad repeat domain 2.

Conclusion S protein is the major target for vaccine development, but several mutations were predicted in the antigenic epitopes of S protein across all genomes available globally. The emergence of various mutations within a short period might result in the conformational changes of the protein structure, which suggests that developing a universal vaccine may be a challenging task.
Factors Influencing Postgraduate Career Decisions of Ophthalmology Residents
Authors: Chen Xinyi , Zafar Sidra , Srikumaran Divya , Boland Michael V. , Johnson Thomas V. , Green Laura K. , Ramanathan Saras , Pettey Jeff , Gedde Steven J. , Woreta Fasika A.
Published: September 2020

Objective This study aims to identify factors that influence ophthalmology residents' decision to pursue fellowship training or to practice comprehensive ophthalmology after residency.

Design This is a cross-sectional study.

Methods An anonymous survey was sent to ophthalmology residents in the United States from the graduating class of 2018. The main outcome measure was the decision to seek fellowship training or to practice comprehensive ophthalmology. Information on demographics, residency program characteristics, and factors influencing career choices were collected.

Results The overall response rate was 24.0% (112/467). Among the 112 respondents, 88 (78.6%) matched into subspecialty training. Compared with residents entering comprehensive ophthalmology, there was a greater proportion of Asians (37.5 vs. 8.3%) and a smaller proportion of non-Hispanic whites (47.7 vs. 70.8%, p = 0.029) among residents pursuing fellowship training. Residents pursuing fellowships had fewer children (0.4 vs. 0.8, p = 0.049), had less debt (median debt ≤ $100,000 vs. > $200,000, p = 0.008), had more first-author publications (4.3 vs. 1.2, p< 0.001), decided on their postgraduate career path earlier (median time postgraduate second year [PGY2] versus postgraduate third year [PGY3], p = 0.016), and were more likely to plan to practice in an academic setting (51.1 vs. 29.2%, p< 0.001) and in an urban location (44.3 vs. 12.5%, p = 0.004). In a multiple logistic regression model, factors predictive of fellowship training included a desire to acquire special skills (odds ratio [OR] =4.39; 95% confidence intervals [CI]: 1.70–16.37) and work with new technology (OR = 2.92; 95% CI: 1.16–10.02). Factors that predicted a career in comprehensive ophthalmology were higher levels of educational debt (OR = 0.35; 95% CI: 0.12–0.77), a later timing of postgraduate decision (OR = 0.17; 95% CI: 0.02–0.65), and lifestyle considerations (OR = 0.13; 95% CI: 0.03–0.36). Gender, prestige, or perceived favorable job market was not significant factors.

Conclusion The majority of U.S. ophthalmology residents matched into fellowships. A desire to gain special skills and a desire to work with new technology were major factors influencing residents to seek fellowship training. Lifestyle considerations and educational debt were more important in the decision to choose a comprehensive ophthalmology career. Future research that includes more trainees and programs may minimize the selection bias issues present in this study.
Mannose-Binding Lectin is Associated with Thrombosis and Coagulopathy in Critically Ill COVID-19 Patients
Authors: Hultström Michael , Frithiof Robert , Eriksson Oskar , Persson Barbro , Lipcsey Miklos , Ekdahl Kristina Nilsson , Nilsson Bo
Published: September 2020

The ongoing COVID-19 pandemic has caused significant morbidity and mortality worldwide, as well as profound effects on society. COVID-19 patients have an increased risk of thromboembolic (TE) complications, which develop despite pharmacological thromboprophylaxis. The mechanism behind COVID-19-associated coagulopathy remains unclear. Mannose-binding lectin (MBL), a pattern recognition molecule that initiates the lectin pathway of complement activation, has been suggested as a potential amplifier of blood coagulation during thromboinflammation. Here we describe data from a cohort of critically ill COVID-19 patients (n = 65) treated at a tertiary hospital center intensive care unit (ICU). A subset of patients had strongly elevated MBL plasma levels, and activity upon ICU admission, and patients who developed symptomatic TE (14%) had significantly higher MBL levels than patients without TE. MBL was strongly correlated to plasma D-dimer levels, a marker of COVID-19 coagulopathy, but showed no relationship to degree of inflammation or other organ dysfunction. In conclusion, we have identified complement activation through the MBL pathway as a novel amplification mechanism that contributes to pathological thrombosis in critically ill COVID-19 patients. Pharmacological targeting of the MBL pathway could be a novel treatment option for thrombosis in COVID-19. Laboratory testing of MBL levels could be of value for identifying COVID-19 patients at risk for TE events.
Individualized Homeopathic Medicines in Chronic Rhinosinusitis: Randomized, Double-Blind, Placebo-Controlled Trial
Authors: Misra Pankhuri , Nayak Chintamani , Chattopadhyay Abhijit , Palit Tarun Kumar , Gupta Bharti , Sadhukhan Satarupa , Bhar Koushik , Rai Shruti , Parewa Maneet , Ali Sk. Swaif , Basu Anamika , Nath Arunava , Koley Munmun , Saha Subhranil
Published: September 2020

Background Chronic rhinosinusitis (CRS) is a common disorder, with up to an estimated 134 million Indian sufferers, and having significant impact on quality of life (QOL) and health costs. Despite the evidence favoring homeopathy in CRS being inadequate, it is highly popular. This trial attempts to study the efficacy of individualized homeopathy (IH) medicines in comparison with placebo in patients with CRS.

Methods A double-blind, randomized (1:1), placebo-controlled, preliminary trial (n = 62) was conducted at the National Institute of Homoeopathy, West Bengal, India. Primary outcome measure was the sino-nasal outcome test-20 (SNOT-20) questionnaire; secondary outcomes were the EQ-5D-5L questionnaire and EQ-5D-5L visual analog scale scores, and five numeric rating scales (0–10) assessing intensity of sneezing, rhinorrhea, post-nasal drip, facial pain/pressure, and disturbance in sense of smell, all measured at baseline and after the 2nd and 4th months of intervention. Group differences and effect sizes (Cohen's d) were calculated on the intention-to-treat sample.

Results Groups were comparable at baseline. Attrition rate was 6.5% (IH: 1, Placebo: 3). Although improvements in both primary and secondary outcome measures were higher in the IH group than placebo, with small to medium effect sizes, the group differences were statistically non-significant (all p > 0.05, unpaired t-tests). Calcarea carbonica, Lycopodium clavatum, Sulphur, Natrum muriaticum and Pulsatilla nigricans were the most frequently prescribed medicines. No harmful or unintended effects, homeopathic aggravations or any serious adverse events were reported from either group.

Conclusion There was a small but non-significant direction of effect favoring homeopathy, which ultimately renders the trial as inconclusive. Rigorous trials and independent replications are recommended to arrive at a confirmatory conclusion. [Trial registration: CTRI/2018/03/012557; UTN: U1111–1210–7201].
Enterochromaffin Cells and Mast Cells in Acute Appendicitis
Authors: Mohan Bhavya P. , Aravindan K.P.
Published: September 2020

Background and Objective Serotonin levels are increased in acute appendicitis. We investigated the possible source of this increase. The aim of this study was to compare the distribution and density of epithelial and nonepithelial enterochromaffin (EC) cells as well as numbers of degranulated and nondegranulated mast cells in different layers of normal appendices and acute appendicitis.

Methods Sections from 15 cases of acute appendicitis and 10 cases where the appendix was morphologically normal were stained with Hematoxylin & Eosin, Toluidine blue, and immunohistochemically for chromogranin and CD-117. EC cells stained by chromogranin were counted per crypt and extraepithelial EC cells counted and expressed as cells per unit area (mm2). Mast cells stained by Toluidine blue and CD-117 were counted in lamina propria, submucosa, and muscle layers. The difference between Toluidine blue and CD117 stained mast cells was taken to be an estimate of degranulated cells. The cell counts were expressed per unit area (mm2) as well as per cross-sectional area of the appendix.

Results There was no statistically significant difference in epithelial and extraepithelial EC cells between acute appendicitis and normal appendix. Estimated mast cell degranulation as indicated by mast cell counts per cross-sectional area is greatly increased in acute appendicitis when compared with normal.

Conclusion Degranulated mast cells rather than EC cells may be the main source of raised serotonin in acute appendicitis.
Crossed-beam slowing to enhance narrow-line ytterbium magneto-optic traps
Authors: Plotkin-Swing Benjamin , Wirth Anna , Gochnauer Daniel , Rahman Tahiyat , McAlpine Katherine E. , Gupta Subhadeep
Published: September 2020

We demonstrate a method to enhance the atom loading rate of a ytterbium (Yb) magneto-optic trap (MOT) operating on the 556 nm 1S0 → 3P1 intercombination transition (narrow linewidth Γg = 2π × 182 kHz). Following traditional Zeeman slowing of an atomic beam near the 399 nm 1S0 → 1P1 transition (broad linewidth Γp = 2π × 29 MHz), two laser beams in a crossed-beam geometry, frequency tuned near the same transition, provide additional slowing immediately prior to the MOT. Using this technique, we observe an improvement by a factor of 6 in the atom loading rate of a narrow-line Yb MOT. The relative simplicity and generality of this approach make it readily adoptable to other experiments involving narrow-line MOTs. We also present a numerical simulation of this two-stage slowing process, which shows good agreement with the observed dependence on experimental parameters, and use it to assess potential improvements to the method.
Demonstrating NISQ era challenges in algorithm design on IBM’s 20 qubit quantum computer
Authors: Koch Daniel , Martin Brett , Patel Saahil , Wessing Laura , Alsing Paul M.
Published: September 2020

As superconducting qubits continue to advance technologically, the realization of quantum algorithms from theoretical abstraction to physical implementation requires knowledge of both quantum circuit construction as well as hardware limitations. In this study, we present results from experiments run on IBM’s 20-qubit “Poughkeepsie” architecture, with the goal of demonstrating various qubit qualities and challenges that arise in designing quantum algorithms. These include experimentally measuring T1 and T2 coherence times, gate fidelities, sequential CNOT gates, techniques for handling ancilla qubits, and finally CCNOT and QFT† circuits implemented on several different qubit geometries. Our results demonstrate various techniques for improving quantum circuits, which must compensate for limited connectivity, either through the use of SWAP gates or additional ancilla qubits.
A zone melting device for the in situ observation of directional solidification using high-energy synchrotron x rays
Authors: Gombola C. , Hasemann G. , Kauffmann A. , Sprenger I. , Laube S. , Schmitt A. , Gang F. , Bolbut V. , Oehring M. , Blankenburg M. , Schell N. , Staron P. , Pyczak F. , Krüger M. , Heilmaier M.
Published: September 2020

Directional solidification (DS) is an established manufacturing process to produce high-performance components from metallic materials with optimized properties. Materials for demanding high-temperature applications, for instance in the energy generation and aircraft engine technology, can only be successfully produced using methods such as directional solidification. It has been applied on an industrial scale for a considerable amount of time, but advancing this method beyond the current applications is still challenging and almost exclusively limited to post-process characterization of the developed microstructures. For a knowledge-based advancement and a contribution to material innovation, in situ studies of the DS process are crucial using realistic sample sizes to ensure scalability of the results to industrial sizes. Therefore, a specially designed Flexible Directional Solidification (FlexiDS) device was developed for use at the P07 High Energy Materials Science beamline at PETRA III (Deutsches Elektronen–Synchrotron, Hamburg, Germany). In general, the process conditions of the crucible-free, inductively heated FlexiDS device can be varied from 6 mm/h to 12 000 mm/h (vertical withdrawal rate) and from 0 rpm to 35 rpm (axial sample rotation). Moreover, different atmospheres such as Ar, N2, and vacuum can be used during operation. The device is designed for maximum operation temperatures of 2200 °C. This unique device allows in situ examination of the directional solidification process and subsequent solid-state reactions by x-ray diffraction in the transmission mode. Within this project, different structural intermetallic alloys with liquidus temperatures up to 2000 °C were studied in terms of liquid–solid regions, transformations, and decompositions, with varying process conditions.
Finnish–Soviet nuclear icebreakers
Authors: Matala Saara
Published: September 2020

During the Cold War, Eastern and Western manufacturers found good reasons to collaborate, even on a technology as sensitive as nuclear vessels.
Graphene gets bent
Authors: Grosso Bastien F. , Mele Eugene J.
Published: September 2020

Two-dimensional nanomaterials are bending the rules of the papercraft known as kirigami.
Physical chemistry and technological applications of gas hydrates: topical aspects
Authors: Manakov Andrey Yu. , Stoporev Andrey S.
Published: September 2020

The review considers the research and engineering works in selected fields of the physical chemistry of gas hydrates and gas hydrate technologies, mainly performed over the last 10–15 years. Data on the hydrate structures are given, including the structures formed during phase transitions at low temperatures, and on new hydrate structures that are formed under ultrahigh pressures. The dynamics of guest and host subsystems is considered in brief. Phase diagrams of systems involving hydrate formation (in particular, in some porous media) and methods for calculating phase equilibria and compositions of hydrates in these systems are analyzed. Data on the hydrates formed by ‘non-classical’ hydrate formers (alcohols, amines, ammonia,etc.) studied in the last decade and on some of their properties are presented. The Section devoted to hydrate formation kinetics addresses the effect of compounds dissolved in water (surfactants, low-dosage inhibitors) and catalysts on this process. The hydrate growth dynamics on the water surface and hydrate decomposition-formation processes in disperse systems are discussed. Among technological applications, the attention is focused on gas storage and transportation in the hydrate form. Methods for the preparation of hydrates are considered.

The bibliography includes 618 references.
Femtosecond visible transient absorption spectroscopy of chlorophyll-
f
-containing photosystem II
Authors: Zamzam Noura , Rakowski Rafal , Kaucikas Marius , Dorlhiac Gabriel , Viola Sefania , Nürnberg Dennis J. , Fantuzzi Andrea , Rutherford A. William , van Thor Jasper J.
Published: September 2020

Significance

Far-red photosystem II (FR-PSII) contains a small number of FR-chlorophylls (-
f
or -
d
) with the rest (∼85%) being chlorophyll-
a
molecules. Here ultrafast studies on FR-PSII support a model in which the primary electron donor is a FR-chlorophyll (P
720
, likely in the Chl
D1
position), while the second electron donor is chlorophyll-
a
at the P
D1
position, forming P
D1
+•
. Excitation energy transfer from chlorophyll-
a
to the FR-chlorophylls is ultrafast. The excited state of FR-chlorophyll remains highly localized, i.e., P
720
* does not share the excitation with the chlorophyll-
a
pigments. This is markedly different from both the conventional, chlorophyll-
a
PSII, and the chlorophyll-
d
PSII of
Acaryochloris marina
. The entropic and site-energy differences result in efficient but apparently slower stabilization of the charge-separated state.
Analysis of the differential expression profile of miRNAs in myocardial tissues of rats with burn injury
Authors: Guo Jingdong , Zhu Zhensen , Zhang Dongmei , Chen Bo , Zou Ben , Gao Songying , Zhu Xiongxiang
Published: September 2020

Fifteen percent third-degree burn rat model was used to identify miRNAs that are markers of burn injury-induced myocardial damage. Cardiac tissues were evaluated to determine miRNA profile sequencing. Pearson’s correlation analysis was used between miRNAs and injury markers. ROC curve analysis was used to estimate miRNA’s sensitivity and specificity for the diagnosis of myocardial damage caused by burn injury. The sequencing analysis revealed 23 differentially expressed miRNAs. Pearson’s correlation analysis revealed that rno-miR-190b-3p and C5b9, rno-miR-341, rno-miR-344b-3p and TnI, rno-miR-344b-3p and CK-MB were significantly positively correlated, respectively. ROC curve analysis demonstrated that rno-miR-341, rno-miR-344b-3p, and rno-miR-190b-3p exhibited high sensitivity and specificity for the diagnosis of myocardial damage caused by burn injury. In conclusion, our results suggest that rno-miR-341, rno-miR-344b-3p, and rno-miR-190b-3p have the potential to be used as sensitive and specific biomarkers to diagnose myocardial damage caused by burn injury.
Are KIF6 and APOE polymorphisms associated with power and endurance athletes?
Authors: Wojciechowicz Bartosz , Laguette M.‐J. Nancy , Sawczuk Marek , Humińska‐Lisowska Kinga , Maciejewska‐Skrendo Agnieszka , Ficek Krzysztof , Michałowska‐Sawczyn Monika , Leońska‐Duniec Agata , Kaczmarczyk Mariusz , Chycki Jakub , Trybek Grzegorz , September Alison V. , Cięszczyk Paweł
Published: September 2020

Genetic polymorphisms within physiologically relevant KIF6 and APOE genes were examined in the context of athletic performance. KIF6 and ApoE are involved in cardiovascular health, modulation of lipid level and neurotransmission amongst others. The aim of this study was to examine whether three polymorphisms, KIF6 rs20455T > C, APOE rs429358T > C and APOE rs7412 C > T, were associated with athletic status of an athlete defined as performance type (endurance or power). Genotyping was performed using real‐time PCR on buccal genomic DNA from 204 Polish athletes including 104 endurance and 100 power athletes, and 161 sedentary individuals. APOE rs429358 genotype frequencies differed significantly between power athletes and sedentary individuals (p = 0.046). KIF6 rs20455 and APOE rs7412 were found to be epistatically associated with the power athletic status (p = 0.032). KIF6 rs20455, APOE rs429358 and APOE rs7412 were associated with athletic status of Polish athletes. In the future, these polymorphisms could contribute to predictive models aimed at assessment of an individual's athletic status.
APOBEC3A catalyzes mutation and drives carcinogenesis in vivo
Authors: Law Emily K. , Levin-Klein Rena , Jarvis Matthew C. , Kim Hyoung , Argyris Prokopios P. , Carpenter Michael A. , Starrett Gabriel J. , Temiz Nuri A. , Larson Lindsay K. , Durfee Cameron , Burns Michael B. , Vogel Rachel I. , Stavrou Spyridon , Aguilera Alexya N. , Wagner Sandra , Largaespada David A. , Starr Timothy K. , Ross Susan R. , Harris Reuben S.
Published: September 2020

The APOBEC3 family of antiviral DNA cytosine deaminases is implicated as the second largest source of mutation in cancer. This mutational process may be a causal driver or inconsequential passenger to the overall tumor phenotype. We show that human APOBEC3A expression in murine colon and liver tissues increases tumorigenesis. All other APOBEC3 family members, including APOBEC3B, fail to promote liver tumor formation. Tumor DNA sequences from APOBEC3A-expressing animals display hallmark APOBEC signature mutations in TCA/T motifs. Bioinformatic comparisons of the observed APOBEC3A mutation signature in murine tumors, previously reported APOBEC3A and APOBEC3B mutation signatures in yeast, and reanalyzed APOBEC mutation signatures in human tumor datasets support cause-and-effect relationships for APOBEC3A-catalyzed deamination and mutagenesis in driving multiple human cancers.
Micro-cathode arc thruster using segmented insulated anode with a slit for micro-satellite propulsion
Authors: Tian Jia , Liu Wenzheng , Zhang Wenjun , Gao Yongjie , Zhao Luxiang
Published: September 2020

Micro-cathode arc thruster (µCAT) is an electric propulsion device that uses metal cathode material as propellent to create plasma and ultimately produce thrust, which is suitable to serve as a propulsion system for microsatellites. In order to improve propulsion performance of the µCAT, a structure using a segmented insulated anode with a slit (SISA-µCAT), which mainly consists of a truncated-cone-shaped cathode, an insulating sleeve, a segmented anode including proximal anode and distant anode, and an anodic insulation layer with a slit, is proposed in this paper. We compare and analyze the differences in discharge characteristics, plasma generation characteristics and propulsion performance among the SISA-µCAT, a segmented exposed anode µCAT (SEA-µCAT) and the known non-segmented exposed anode µCAT (NSEA-µCAT). Study results show that when adopting the SISA-µCAT, plasma ejection performance is effectively improved by utilizing the special spatial electric field formed between segmented anode and the slit structure on the anodic insulation layer, thus improving the propulsion performance of the µCAT. During a single shot, compared with the NSEA-µCAT, peak values of generated thrust and thrust-to-power ratio are increased by 11.4 times and 10.4 times, respectively, by using the SISA-µCAT. Plasma parameters indicate that peak plasma density and propagation speed are increased by 8.2 times and 2.93 times, respectively.
High-precision three-dimensional atom localization via probe absorption at room temperature
Authors: Luo Mengmeng , Liu Wenxiao , Cai Dingyu , Gao Shaoyan
Published: September 2020

A scheme is used to explore the behavior of three-dimensional (3D) atom localization in a Y-type hot atomic system. We can obtain the position information of the atom due to the position-dependent atom–field interaction. We study the influences of the system parameters and the temperature on the atom localization. More interestingly, the atom can be localized in a subspace when the temperature is equal to 323 K. Moreover, a method is proposed to tune multiparameter for localizing the atom in a subspace. The result is helpful to achieve atom nanolithography, photonic crystal and measure the center-of-mass wave function of moving atoms.
Functionalized magnetic nanoparticles for drug delivery in tumor therapy*
Authors: Li Ruo-Nan , Da Xian-Hong , Li Xiang , Lu Yun-Shu , Gu Fen-Fen , Liu Yan
Published: September 2020

The side effects of chemotherapy are mainly the poor control of drug release. Magnetic nanoparticles (MNPs) have super-paramagnetic behaviors which are preferred for biomedical applications such as in targeted drug delivery, besides, in magnetic recording, catalysis, and others. MNPs, due to high magnetization response, can be manipulated by the external magnetic fields to penetrate directly into the tumor, thus they can act as ideal drug carriers. MNPs also play a crucial role in drug delivery system because of their high surface-to-volume ratio and porosity. The drug delivery in tumor therapy is related to the sizes, shapes, and surface coatings of MNPs as carriers. Therefore, in this review, we first summarize the effects of the sizes, shapes, and surface coatings of MNPs on drug delivery, then discuss three types of drug release systems, i.e., pH-controlled, temperature-controlled, and magnetic-controlled drug release systems, and finally compare the principle of passive drug release with that of active drug release in tumor therapy.
Ab initio study on crystal structure and phase stability of ZrC2 under high pressure*
Authors: Guo Yong-Liang , Wei Jun-Hong , Liu Xiao , Ke Xue-Zhi , Jiao Zhao-Yong
Published: September 2020

The structural stabilities and crystal evolution behaviors of the hyper stoichiometric compound ZrC2 (carbon rich; C/Zr > 1.0) are studied under ambient and high pressure conditions using first-principles calculations in combination with the particle-swarm optimization algorithm. Six viable structures of ZrC2 in P21/c, Cmmm, Cmc21, P42/nmc, Immm and P6/mmm symmetries are identified. These structures are dynamically stable as their phonon spectra have no imaginary modes at zero pressure or at the selected high-pressure points. Among them, the P21/c phase represents the ground state structure, whereas P21/c, P42/nmc, Immm and P6/mmm phases are part of the phase transition series. The phase order and critical pressures of the phase transition are determined to be approximately 300 GPa according to the equation of states and enthalpy. Furthermore, the mechanical and electronic properties are investigated. The P21/c and Cmc21 phases display a semi-metal nature, whereas the P42/nmc, Immm, P6/mmm and Cmmm phases exhibit a metallic nature. Moreover, the present study reveals considerable information regarding the structural, mechanical and electronic properties of ZrC2, thereby providing key insights into its material properties and evaluating its behavior in practical applications.
Atomistic study on tensile fracture of densified silica glass and its dependence on strain rate*
Authors: Hu Zhi-Qiang , Shao Jian-Li , Xie Yi-Fan , Mei Yong
Published: September 2020

Densification is a major feature of silica glass that has received widespread attention. This work investigates the fracture behavior of densified silica glass upon uniaxial tension based on atomistic simulations. It is shown that the tensile strength of the silica glass approximately experiences a parabolic reduction with the initial density, while the densified samples show a faster power growth with the increase of strain rate. Meanwhile, the fracture strain and strain energy increase significantly when the densification exceeds a certain threshold, but fracture strain tends to the same value and strain energy becomes closer for different densified samples at extreme high strain rate. Microscopic views indicate that all the cracks are formed by the aggregation of nanoscale voids. The transition from brittleness fracture to ductility fracture can be found with the increase of strain rate, as a few fracture cracks change into a network distribution of many small cracks. Strikingly, for the high densified sample, there appears an evident plastic flow before fracture, which leads to the crack number less than the normal silica glass at the high strain rate. Furthermore, the coordinated silicon analysis suggests that high strain rate tension will especially lead to the transition from 4- to 3-fold Si when the high densified sample is in plastic flow.
High-order rational solutions and resonance solutions for a (3+1)–dimensional Kudryashov-Sinelshchikov equation*
Authors: Yue Yun-Fei , Lin Jin , Chen Yong
Published: September 2020

We mainly investigate the rational solutions and N-wave resonance solutions for the (3+1)-dimensional Kudryashov–Sinelshchikov equation, which could be used to describe the liquid containing gas bubbles. With appropriate transformations, two kinds of bilinear forms are derived. Employing the two bilinear equations, dynamical behaviors of nine district solutions for this equation are discussed in detail, including bright rogue wave-type solution, dark rogue wave-type solution, bright W-shaped solution, dark W-shaped rational solution, generalized rational solution and bright-fusion, dark-fusion, bright-fission, and dark-fission resonance solutions. In addition, the generalized rational solutions, which depending on two arbitrary parameters, have an interesting structure: splitting from two peaks into three peaks.
Neutron drip line of Z= 9–11 isotopic chains *
Authors: An Rong , Shen Guo-Fang , Zhang Shi-Sheng , Geng Li-Sheng
Published: September 2020

A recent experimental breakthrough identified the last bound neutron-rich nuclei in fluorine and neon isotopes. Based on this finding, we perform a theoretical study of Z = 9, 10, 11, 12 isotopes in the relativistic mean field (RMF) model. The mean field parameters are assumed from the PK1 parameterization, and the pairing correlation is described by the particle number conservation BCS (FBCS) method recently formulated in the RMF model. We show that the FBCS approach plays an essential role in reproducing experimental results of fluorine and neon isotopes. Furthermore, we predict 39Na and 40Mg to be the last bound neutron-rich nuclei in sodium and magnesium isotopes.
Fully implanted adaptive deep brain stimulation in freely moving essential tremor patients
Authors: Ferleger B I , Houston B , Thompson M C , Cooper S S , Sonnet K S , Ko A L , Herron J A , Chizeck H J
Published: September 2020

Objective. Deep brain stimulation (DBS) is a safe and established treatment for essential tremor (ET) and several other movement disorders. One approach to improving DBS therapy is adaptive DBS (aDBS), in which stimulation parameters are modulated in real time based on biofeedback from either external or implanted sensors. Previously tested systems have fallen short of translational applicability due to the requirement for patients to continuously wear the necessary sensors or processing devices, as well as privacy and security concerns.Approach. We designed and implemented a translation-ready training data collection system for fully implanted aDBS. Two patients chronically implanted with electrocorticography strips over the hand portion of M1 and DBS probes in the ipsilateral ventral intermediate nucleus of the thalamus for treatment of ET were recruited for this study. Training was conducted using a translation-ready distributed training procedure, allowing a substantially higher degree of control over data collection than previous works. A linear classifier was trained using this system, biased towards activating stimulation in accordance with clinical considerations.Main results. The clinically relevant average false negative rate, defined as fraction of time during which stimulation dropped below12clinical levels during movement epochs, was 0.036. Tremor suppression, calculated through analysis of gyroscope data, was 33.2% more effective on average with aDBS than with continuous DBS. During a period of free movement with aDBS, one patient reported a slight paresthesia; patients noticed no difference in treatment efficacy between systems.Significance. Here is presented the first translation-ready training procedure for a fully embedded aDBS control system for MDs and one of the first examples of such a system in ET, adding to the consensus that fully implanted aDBS systems are sufficiently mature for broader deployment in treatment of movement disorders.
Side-impact collision: mechanics of obstacle negotiation in sidewinding snakes
Authors: Astley Henry C , Rieser Jennifer M , Kaba Abdul , Paez Veronica M , Tomkinson Ian , Mendelson Joseph R , Goldman Daniel I
Published: September 2020

Snakes excel at moving through cluttered environments, and heterogeneities can be used as propulsive contacts for snakes performing lateral undulation. However, sidewinding, which is often associated with sandy deserts, cuts a broad path through its environment that may increase its vulnerability to obstacles. Our prior work demonstrated that sidewinding can be represented as a pair of orthogonal body waves (vertical and horizontal) that can be independently modulated to achieve high maneuverability and incline ascent, suggesting that sidewinders may also use template modulations to negotiate obstacles. To test this hypothesis, we recorded overhead video of four sidewinder rattlesnakes (Crotalus cerastes) crossing a line of vertical pegs placed in the substrate. Snakes used three methods to traverse the obstacles: a Propagate Through behavior in which the lifted moving portion of the snake was deformed around the peg and dragged through as the snake continued sidewinding (115/160 runs), Reversal turns that reorient the snake entirely (35/160), or switching to Concertina locomotion (10/160). The Propagate Through response was only used if the anterior-most region of static contact would propagate along a path anterior to the peg, or if a new region of static contact could be formed near the head to satisfy this condition; otherwise, snakes could only use Reversal turns or switch to Concertina locomotion. Reversal turns allowed the snake to re-orient and either escape without further peg contact or re-orient into a posture amenable to using the Propagate Through response. We developed an algorithm to reproduce the Propagate Through behavior in a robophysical model using a modulation of the two-wave template. This range of behavioral strategies provides sidewinders with a versatile range of options for effectively negotiating obstacles in their natural habitat, as well as provide insights into the design and control of robotic systems dealing with heterogeneous habitats.
Disturbance reinforces community assembly processes differentially across spatial scales
Authors: Escobedo Víctor M , Rios Rodrigo S , Alcayaga-Olivares Yulinka , Gianoli Ernesto
Published: September 2020

Background and Aims

There is a paucity of empirical research and a lack of predictive models concerning the interplay between spatial scale and disturbance as they affect the structure and assembly of plant communities. We proposed and tested a trait dispersion-based conceptual model hypothesizing that disturbance reinforces assembly processes differentially across spatial scales. Disturbance would reinforce functional divergence at the small scale (neighbourhood), would not affect functional dispersion at the intermediate scale (patch) and would reinforce functional convergence at the large scale (site). We also evaluated functional and species richness of native and exotic plants to infer underlying processes. Native and exotic species richness were expected to increase and decrease with disturbance, respectively, at the neighbourhood scale, and to show similar associations with disturbance at the patch (concave) and site (negative) scales.

Methods

In an arid shrubland, we estimated species richness and functional dispersion and richness within 1 m2 quadrats (neighbourhood) nested within 100 m2 plots (patch) along a small-scale natural disturbance gradient caused by an endemic fossorial rodent. Data for the site scale (2500 m2 plots) were taken from a previous study. We also tested the conceptual model through a quantitative literature review and a meta-analysis.

Key Results

As spatial scale increased, disturbance sequentially promoted functional divergence, random trait dispersion and functional convergence. Functional richness was unaffected by disturbance across spatial scales. Disturbance favoured natives over exotics at the neighbourhood scale, while both decreased under high disturbance at the patch and site scales.

Conclusions

The results supported the hypothesis that disturbance reinforces assembly processes differentially across scales and hampers plant invasion. The quantitative literature review and the meta-analysis supported most of the model predictions.
MR-Clust: clustering of genetic variants in Mendelian randomization with similar causal estimates
Authors: Foley Christopher N , Mason Amy M , Kirk Paul D W , Burgess Stephen
Published: September 2020

Motivation

Mendelian randomization is an epidemiological technique that uses genetic variants as instrumental variables to estimate the causal effect of a risk factor on an outcome. We consider a scenario in which causal estimates based on each variant in turn differ more strongly than expected by chance alone, but the variants can be divided into distinct clusters, such that all variants in the cluster have similar causal estimates. This scenario is likely to occur when there are several distinct causal mechanisms by which a risk factor influences an outcome with different magnitudes of causal effect. We have developed an algorithm MR-Clust that finds such clusters of variants, and so can identify variants that reflect distinct causal mechanisms. Two features of our clustering algorithm are that it accounts for differential uncertainty in the causal estimates, and it includes ‘null’ and ‘junk’ clusters, to provide protection against the detection of spurious clusters.

Results

Our algorithm correctly detected the number of clusters in a simulation analysis, outperforming methods that either do not account for uncertainty or do not include null and junk clusters. In an applied example considering the effect of blood pressure on coronary artery disease risk, the method detected four clusters of genetic variants. A post hoc hypothesis-generating search suggested that variants in the cluster with a negative effect of blood pressure on coronary artery disease risk were more strongly related to trunk fat percentage and other adiposity measures than variants not in this cluster.

Availability and implementation

MR-Clust can be downloaded from https://github.com/cnfoley/mrclust.

Supplementary information

Supplementary data are available at Bioinformatics online.
How often do they do it? An in-depth analysis of the hybrid zone of two grass snake species (Natrix astreptophoraandNatrix helvetica)
Authors: Asztalos Marika , Schultze Nadine , Ihlow Flora , Geniez Philippe , Berroneau Matthieu , Delmas Claudine , Guiller Gaëtan , Legentilhomme Jérôme , Kindler Carolin , Fritz Uwe
Published: September 2020

We examined the contact zone of two parapatric species of grass snake (Natrix astreptophora and Natrix helvetica) in southern France. To this end, we used comprehensive sampling, analysed mtDNA sequences and microsatellite loci, and built Species Distribution Models for current and past climatic conditions. The contact zone had established by the mid-Holocene during range expansions from glacial refuges in the Iberian Peninsula (N. astreptophora) and southern or western France (N. helvetica). The contact zone represents a narrow bimodal hybrid zone, with steep genetic transition from one taxon to the other and rare hybridization, supporting species status for N. astreptophora and N. helvetica. Our results suggest that the steepness of the clines is a more robust tool for species delimitation than cline width. In addition, we discovered in western France, beyond the hybrid zone, a remote population of N. helvetica with genetic signatures of hybridization with N. astreptophora, most likely the result of human-mediated long-distance dispersal. For N. helvetica, we identified a southern and a northern population cluster, connected by broad-scale gene flow in a unimodal hybrid zone running across France. This pattern either reflects genetic divergence caused by allopatry in two microrefuges and subsequent secondary contact or introgression of foreign alleles into the southern cluster.
Neuropsychiatric symptoms in limbic-predominant age-related TDP-43 encephalopathy and Alzheimer’s disease
Authors: Liu Kathy Y , Reeves Suzanne , McAleese Kirsty E , Attems Johannes , Francis Paul , Thomas Alan , Howard Robert
Published: September 2020

There is clinical overlap between presentations of dementia due to limbic-predominant age-related TDP-43 encephalopathy (LATE) and Alzheimer’s disease. It has been suggested that the combination of Alzheimer’s disease neuropathological change (ADNC) and LATE neuropathological changes (LATE-NC) is associated with greater neuropsychiatric symptom burden, compared to either pathology alone. Longitudinal Neuropsychiatric Inventory and psychotropic medication prescription data from neuropathologically diagnosed pure ADNC (n = 78), pure LATE-NC (n = 14) and mixed ADNC/LATE-NC (n = 39) brain bank donors were analysed using analysis of variance and linear mixed effects regression models to examine the relationship between diagnostic group and neuropsychiatric symptom burden. Nearly all donors had dementia; three (two pure LATE-NC and one pure ADNC) donors had mild cognitive impairment and another two donors with LATE-NC did not have dementia. The mixed ADNC/LATE-NC group was older than the pure ADNC group, had a higher proportion of females compared to the pure ADNC and LATE-NC groups, and had more severe dementia versus the pure LATE-NC group. After adjustment for length of follow-up, cognitive and demographic factors, mixed ADNC/LATE-NC was associated with lower total Neuropsychiatric Inventory and agitation factor scores than pure ADNC, and lower frontal factor scores than pure LATE-NC. Our findings indicate that concomitant LATE pathology in Alzheimer’s disease is not associated with greater neuropsychiatric symptom burden. Future longitudinal studies are needed to further investigate whether mixed ADNC/LATE-NC may be protective against agitation and frontal symptoms in dementia caused by Alzheimer’s disease or LATE pathology.