bluuebunny/crossref_metadata_2025 huggingface dataset:
Dielectrons and Direct Virutal Photons at RHIC-STAR
Authors: Yang Chi
Published: June 2020

Electromagnetic probes are unique probes of the hot and dense medium cre- ated in relativistic heavy-ion collisions due to their minimal interactions with the partonic and hadronic medium. They can be produced at all stages of a collision, thus they provide unique ways to study the medium properties of the whole collision evolution. We present the dielectron invariant mass spectrum at √sNN = 27, 39, 39, and 62.4 GeV. Comparing to hadronic cocktail simulation, significant excesses of dielectron invariant mass spectrum at low mass are observed. The direct virtual photon invariant yields derived from the low-mass e+e− continuum in Au+Au collisions at √sNN = 200 GeV is presented and the excesses from thermal photons in low transverse momentum (pT) have been observed. Model calculations can simultaneously describe both dielectron low mass excesses and direct virtual photon low pT excesses.
Study of soft photon yield in pp and AA interactions at JINR
Authors: Kokoulina Elena , Barlykov Nurlan , Dudin Vladimir , Dunin Vladimir , Kutov Andrey , Nikitin Vladimir , Riadovikov Vasilii , Shulyakovsky Roman
Published: June 2020

Over 30 years there has been no comprehensive understanding of the mechanism of soft photons (energy smaller than 50 MeV) formation. Experimental data indicate an excess of their yield in hadron and nuclear interactions in comparison with calculations performed in QED. For a more thorough study of this phenomenon at the Nuclotron (a superconducting accelerator in JINR), preliminary measurements have been carried out with using an electromagnetic calorimeter based on BGO crystals. These results are consistent with the world data. In JINR, in connection with the building of a future accelerator complex NICA, it has become possible to carry out such studies in pp, pA and AA interactions at energies up to 25 A GeV. Our group develops the conception of an heterogeneous electromagnetic calorimeter as “spaghetti” and “shashlik” types based on gadolinium gallium garnet (GaGG) crystals with a low threshold for registration of photons. The first tests of prototypes of them manufactured at JINR on the basis of the GaGG and a mixture of tungstate and copper as an absorber are reported.
Reconstruction of neutral-triggered charged recoil jets in √s = 200 GeV p+p collisions at the STAR experiment
Authors: Anderson Derek
Published: June 2020

Jets — collimated sprays of hadrons — are produced by hard-scattered partons during the early stages of heavy ion collisions. Hence, they provide a valuable probe of the complex multi-particle dynamics within the hot, dense medium produced in such collisions. In particular, the study of jets recoiling from direct photons (γdir+jet) and those recoiling from energetic π0 (π0+jet) may shed light on the path-length and initial flavor (quark vs. gluon) dependence of the energy-loss experienced by a parton as it traverses the medium. We present here measurements of the yields of charged recoil jets tagged by γdir and π0 in p+p collisions at √S = 200 GeV. These measurements will serve as a vacuum fragmentation reference for an upcoming measurement in Au + Au collisions.
What can neutron stars reveal about the equation of state of dense matter?
Authors: Tews Ingo
Published: June 2020

Neutron stars are astrophysical objects of extremes, reaching the highest densities we can observe in the cosmos, and probing matter under conditions that cannot be recreated in terrestrial experiments. In August 2017, the first neutron-star merger has been observed, which provided compelling evidence that these events are an important site for r-process nucleosynthesis. Furthermore, the gravitational-wave signal of such events might shed light upon the nature of strongly interacting matter in the neutron-star core. To understand these remarkable events, reliable nuclear physics input is essential. In this contribution, I explain how to use chiral effective field theory and advanced many-body methods to provide a consistent and systematic approach to strongly inter- acting systems from nuclei to neutron stars with controlled theoretical uncertainties. I will discuss recent results for the equation of state relevant for the nuclear astrophysics of neutron stars and neutron-star mergers.
New water mite species of the genus Rhyncholimnochares Lundblad (Acariformes, Limnocharidae) from Central and South America, with a key to all known species of the genus
Authors: Tuzovskij Petr , Gerecke Reinhard
Published: June 2020

In the genus Rhyncholimnochares, a total of 11 species new to science is described, 10 representatives of the subgenus Rhyncholimnochares s. str. − R. ursula sp. n., R. minuta sp. n., R. cooki sp. n., R. jicotea sp. n., R. lundbladi sp. n. and R. monikae sp. n. from Costa Rica; R. expansipalpis sp. n., R. petaliseta sp. n, R. tapiarum sp. n., R. glabra sp. n. from Ecuador (the latter recorded also from Brazil and Chile), and one representative of the subgenus Paralimnochares, R. chilensis sp. n. from Chile. New records are given for R. (s. str.) lamellipalpis (O. Lundblad 1936. Dritte Mitteilung über neue Wassermilben aus Santa Catharina in Südbrasilien. Zool Anz 116 (7-8): 200–211.) from Chile. A determination key is given for all known species at the adult/deutonymphal stage.
5-Jahres-Ergebnisse eines ambulanten, ärztlich betreuten Adipositastherapieprogramms
Authors: Becker Christine , Walle Hardy
Published: June 2020

Hintergrund Übergewicht und Adipositas bestimmen zunehmend unseren Alltag. In Deutschland ist mehr als jeder Zweite übergewichtig, fast jeder Vierte adipös. Normalgewicht weist weniger als die Hälfte der Bevölkerung auf. Adipositas nimmt insbesondere in den jungen Altersklassen zu, sodass immer mehr eine adipöse Gesellschaft heranwächst. Dies stellt unsere Gesellschaft, den Arbeitsmarkt sowie das Gesundheits- und Sozialsystem vor neue Herausforderungen. Um diesen Entwicklungen nachhaltig begegnen zu können, sind alltagstaugliche Maßnahmen notwendig.

Material und Methodik 5-Jahres-Ergebnisse einer multizentrischen Erhebung von 135 adipösen Teilnehmern (46 Männer [34,1 %], 89 Frauen [65,9 %]) an einem 12-wöchigen, ambulanten, ärztlich betreuten Adipositastherapieprogramm. Anschließend besteht die Möglichkeit zur Teilnahme an einer Langzeitbetreuung. Die Kombination von Ernährungsumstellung, Verhaltensänderung und Steigerung der Bewegungsaktivität bilden die Programmschwerpunkte. Vorgestellt werden die Veränderungen von Körpergewicht, BMI und Körperzusammensetzung.

Ergebnisse Alle Gruppen (Gesamtgruppe, Männer, Frauen) erzielten eine kontinuierliche Gewichtsabnahme über mindestens 6 Monate – und damit über den 12-wöchigen Kursverlauf hinaus. Trotz Wiederzunahmen befand sich das mittlere Körpergewicht zu jedem Messzeitpunkt in allen Gruppen unter den Ausgangswerten. Nach 5 Jahren bestand in der Gesamtgruppe noch ein mittlerer Gewichtsverlust von 3,8 kg/3,6 % (P < 0,001). 41,5 % (N = 56) der Teilnehmer hatten ihr Körpergewicht zu diesem Zeitpunkt um mind. 5 %, 22,2 % (N = 30) um mind. 10 % vermindert. Die Gewichtsabnahme erfolgte überwiegend über Körperfett, bei Steigerung der relativen Anteile der stoffwechselaktiven Masse sowie des Körperwassers.

Schlussfolgerung Das vorgestellte, ambulante, ärztlich betreute Adipositastherapieprogramm bietet auch über 5 Jahre – und damit deutlich über den regulären Kurszeitraum hinaus – die Möglichkeit für eine deutliche Gewichtsabnahme, die überwiegend über Körperfett erfolgt.
Screening for New Markers to Assess Thyroid Hormone Action by OMICs
Analysis of Human Samples
Authors: Friedrich Nele , Pietzner Maik , Engelmann Beatrice , Homuth Georg , Führer Dagmar , Brabant Georg , Wallaschofski Henri , Völker Uwe
Published: June 2020

Determination of the levels of thyroid-stimulating hormone (TSH) and free
thyroid hormones (fTHs) is crucial for assessing thyroid function. However,
as a result of inter-individual genetic variability and different
environmental factors individual set points exist for TSH and fTHs and
display considerable variation. Furthermore, under specific
pathophysiological conditions like central hypothyroidism, TSH secreting
pituitary tumors, or thyroid hormone resistance the established markers TSH
and fTH fail to reliably predict thyroid function and adequate supply of TH
to peripheral organs. Even in case of overt hyper- and hypothyroidism
circulating fTH concentrations do not correlate with clinical symptoms.
Therefore, there is a clear need for novel, more specific biomarkers to
diagnose and monitor thyroid function. OMICs screening approaches allow
parallel profiling of hundreds to thousands of molecules and thus
comprehensive monitoring of molecular alterations in tissues and body fluids
that might be associated with changes in thyroid function. These techniques
thus constitute promising tools for the identification of urgently needed
novel biomarkers. This mini review summarizes the findings of OMICs studies
in thyroid research with a particular focus on population-based and patient
studies as well as interventional approaches investigating the effects of
thyroid hormone administration.
Cryoballoon ablation for treatment of patients with refractory esophageal neoplasia after first line endoscopic eradication therapy
Authors: Alzoubaidi Durayd , Hussein Mohamed , Sehgal Vinay , Makahamadze Christwishes , Magee Cormac G. , Everson Martin , Graham David , Sweis Rami , Banks Matthew , Sami Sarmed S. , Novelli Marco , Lovat Laurence , Haidry Rehan
Published: June 2020

Background and study aims Cryoablation with the Cryoballoon device is a novel ablative therapy that uses cycles of freezing and thawing to induce cell death. This single-center prospective study evaluated the feasibility of the focal cryoablation device for the treatment of areas of refractory esophageal neoplasia in patients who had undergone first line endoscopic eradication therapy (EET). Complete remission of dysplasia (CR-D) and complete remission of intestinal metaplasia (CR-IM) at first follow-up endoscopy, durability of disease reversal, rates of stenosis and adverse events were studied.

Patients and methods Eighteen cases were treated. At baseline, nine patients had low-grade dysplasia (LGD), six had high-grade dysplasia (HGD) and three had intramucosal carcinoma (IMC). Median length of dysplastic Barrett’s esophagus (BE) treated was 3 cm. The median number of ablations per patient was 11. Each selected area of visible dysplasia received 10 seconds of ablation. One session of cryoablation was performed per patient. Biopsies were performed at around 3 months post-ablation.

Results CR-D was achieved in 78 % and CR-IM in 39 % of patients. There were no device malfunction or adverse events. Stenosis was noted in 11 % of cases. At a median follow up of 19-months, CR-D was maintained in 72 % of patients and CR-IM in 33 %.

Conclusions Cryoablation appears to be a viable rescue strategy in patients with refractory neoplasia. It is well tolerated and successful in obtaining CR-D and CR-IM in patients with treatment-refractory BE. Further trials of dosimetry, efficacy and safety in treatment-naïve patients are underway.
Systemtherapie des Gallenblasenkarzinoms – alles wie beim Cholangiokarzinom?
Authors: Walter Dirk , Trojan Jörg , Waidmann Oliver
Published: June 2020

Genomische Analysen zeigten relevante Unterschiede zwischen Gallenblasenkarzinomen und extra- sowie intrahepatischen Cholangiokarzinomen. Diese Daten haben jedoch derzeit keinen Einfluss auf die Wahl systemischer Therapieansätze. In dieser Übersicht werden zunächst Epidemiologie, Pathogenese und molekulare Charakterisierung des Gallenblasenkarzinoms dargestellt und es wird auf Unterschiede im Vergleich zum intra- und extrahepatischen Cholangiokarzinom eingegangen. Die aktuellen Optionen in der Systemtherapie des Gallenblasenkarzinoms werden diskutiert und es wird ein Ausblick auf die derzeit in der Entwicklung befindlichen Therapien gegeben.
Outcomes of EUS-guided choledochoduodenostomy as primary drainage for distal biliary obstruction with covered self-expandable metallic stents
Authors: Kuraoka Naosuke , Hara Kazuo , Okuno Nozomi , Kuwahara Takamichi , Mizuno Nobumasa , Shimizu Yasuhiro , Niwa Yasumasa , Terai Shuji
Published: June 2020

Background and study aims Endoscopic ultrasonography-guided choledochoduodenostomy (EUS-CDS) is an alternative therapy for percutaneous transhepatic biliary drainage. Outcomes of EUS-CDS for distal biliary tract obstruction with a covered self-expandable metallic stent (SEMS) as a primary drainage technique are unclear because there are few relevant reports. This study aimed to determine outcomes in patients undergoing EUS-CDS using SEMS as the primary drainage technique for malignant distal biliary duct obstruction.

Patients and methods This retrospective study was conducted at Aichi Cancer Center Hospital, from January 2010 to July 2018, using data from our database.

Results EUS-CDS was performed as a primary drainage technique for 92 patients. The technical success rate was 92.8 %, and the clinical success rate was 91.6 %. The overall incidence of adverse events was 15.7 %. The median stent patency time for the EUS-CDS was 396 days. Nineteen patients required re-intervention because of cholangitis or jaundice.

Conclusion EUS-CDS as a primary drainage technique using SEMS has high technical and clinical success rates. It should be considered an effective drainage method with respect to long-term stent patency, low re-intervention rates, and absence of severe complications.
Interhemisphärische Kohärenzen des EEG als integrativer Leistungsindikator bei flugspezifischen Belastungen
Authors: Wirth Dietrich Oswald
Published: June 2020

Neue technische Voraussetzungen ermöglichen potenziell neue Ansätze zur Onlineüberwachung der zerebralen Leistungsfähigkeit von Piloten und könnten dadurch die Flugsicherheit erhöhen. In den eigenen Untersuchungen während der Beschleunigungen von +2,5, +3,0 und +3,5 Gz auf einer Hochleistungszentrifuge ließen sich dominierend statistisch signifikante Anstiege homo- und heterotop interhemisphärischer sowie intrahemisphärischer Kohärenzen vorzugsweise im Betaband nachweisen, die im Sinne einer zerebralen Aktivierung zu werten sind. Dagegen wiesen die homotop interhemisphärischen Kohärenzen während des Aufenthalts in den Höhen 18 000 und 25 000 ft statistisch signifikante Verminderungen auf. Diese generellen Änderungsrichtungen der Kohärenzen des EEG waren aber infolge erheblicher inter- und intraindividueller Variabilität der verschiedenen Kohärenzen in Bezug auf ihre Ableitpositionen und Frequenzbänder hinsichtlich ihrer Größe und ihrem zeitlichen Auftreten uneinheitlich. Dies betrifft sowohl die intraindividuelle Variabilität der Hypoxiesensitivität verschiedener Großhirnrindenbereiche als auch die interindividuellen Differenzen der interhemisphärischen Kohärenzen bei Beschleunigung +Gz und ihren statistischen Zusammenhang mit hormonellen Aktivierungsparametern.
Aromatherapie in der Palliativpflege
Authors: Demleitner Margret
Published: June 2020

Die Palliativpflege versucht, so lange es geht, durch Verminderung des Leidens ein erfülltes Leben zu ermöglichen. Das Leid kann sowohl emotional als auch körperlich sein. Die Nähe des Todes macht den Patienten, den Angehörigen und auch den Behandlern oft Angst. Beklommenheit und Hilflosigkeit treten auf. Mit ätherischen Ölen kann eine Brücke zu den Sterbenden gebaut werden – die Angehörigen und Behandler haben die Möglichkeit, sich an der Pflege zu beteiligen und den Patienten eine Oase der Ruhe und des Friedens zu geben. Der Beitrag führt wichtige Aromaöle auf und zeigt anhand vieler Rezepturen deren Verwendung in der Palliativpflege.
Verbrennungen und Verbrühungen: Wundversorgung bei Kindern
Authors: Zuzak Tycho Jan , Michael Karin , Längler Alfred
Published: June 2020

Bei Kindern steht die Häufigkeit von Brandverletzungen an dritter Stelle der Unfallursachen. Dabei sind mehr als 70 % dieser thermischen Verletzungen auf Schädigung durch Verbrühung zurückzuführen. Sind die betroffenen Hautareale eher klein und übersteigt die Verbrennungstiefe nicht den zweiten Grad, so können diese Verletzungen meist noch ambulant versorgt werden. Hier stehen die Vermeidung einer Wundinfektion und das schnelle und narbenfreie Abheilen der verletzten Haut im Vordergrund. Um dieses Behandlungsziel zu erreichen, entwickelten Ärzte der Abteilung für Kinder- und Jugendmedizin des Gemeinschaftskrankenhauses Herdecke ein Therapiekonzept unter Einsatz anthroposophischer Arzneimittel, mit denen im Praxisalltag sehr gute Ergebnisse erzielt werden können. Im Folgenden wird dieses etablierte Therapiekonzept auf Basis der klinischen Erfahrungen aus dem Alltag vorgestellt und die wundheilungsfördernden pflanzlichen Bestandteile der verwendeten Arzneimittel werden erläutert.
Endoscopic retrograde pancreatography-guided versus endoscopic ultrasound-guided technique for pancreatic duct cannulation in patients with pancreaticojejunostomy stenosis: a systematic literature review
Authors: Basiliya Kirill , Veldhuijzen Govert , Gerges Christian , Maubach Johannes , Will Uwe , Elmunzer B. Joseph , Stommel Martijn W. J. , Akkermans Reinier , Siersema Peter D. , van Geenen Erwin-Jan M.
Published: June 2020

Background Stenosis of the pancreaticojejunostomy is a well-known long-term complication of pancreaticoduodenectomy. Traditionally, the endoscopic approach consisted of endoscopic retrograde pancreatography (ERP). Endoscopic ultrasound (EUS)-guided intervention has emerged as an alternative, but the success rate and adverse event rate of both treatment modalities are poorly known. We aimed to compare the outcome data of both interventions.

Methods We performed a systematic literature search using the Pubmed/Medline and Embase databases in order to summarize the available data regarding efficacy and complications of ERP- and EUS-guided pancreatic duct (PD) drainage and compare these outcome data using uniform outcome measures in a multilevel logistic model.

Results 13 studies were included, involving 77 patients who underwent ERP-guided drainage, 145 who underwent EUS-guided drainage, and 12 patients who underwent both modalities. An EUS-guided approach was significantly superior to an ERP-guided approach with regard to pancreatic duct opacification (87 % vs. 30 %; P < 0.001), cannulation success (79 % vs. 26 %; P < 0.001), and stent placement (72 % vs. 20 %; P < 0.001). An EUS-guided approach also appeared superior with regard to clinical outcomes such a pain resolution. The adverse event rate between the two treatment modalities could not be compared due to insufficient data. All included studies were found to be of low quality.

Conclusion Based on limited available data, EUS-guided PD intervention appears superior to ERP-guided PD intervention.
Efficacy and safety of peroral cholangioscopy with intraductal lithotripsy for difficult biliary stones: a systematic review and meta-analysis
Authors: McCarty Thomas R. , Gulati Rishabh , Rustagi Tarun
Published: June 2020

Background Peroral cholangioscopy with intraductal lithotripsy facilitates optically guided stone fragmentation of difficult biliary stones refractory to conventional endoscopic therapy. The aim of this study was to evaluate the efficacy and safety of peroral cholangioscopy with intraductal lithotripsy for difficult biliary stones.

Methods Searches of PubMed, EMBASE, Web of Science, and Cochrane databases were performed in accordance with PRISMA and MOOSE guidelines. Measured outcomes included overall fragmentation success, single-session fragmentation and duct clearance, and rate of adverse events. Sensitivity and subgroup analyses were performed based upon cholangioscopy technique and type of lithotripsy (laser versus electrohydraulic). Heterogeneity was assessed with I
2 statistics. Publication bias was ascertained by funnel plot and Egger regression testing.

Results 35 studies were included with 1762 participants (43.4 % men; mean age 61.5 [standard deviation (SD) 11.0]). Prior cholecystectomy had been performed in 37 % of patients, with a mean number of 1.6 (SD 0.5) ERCPs performed prior to lithotripsy. Mean stone size was 1.8 (SD 0.3) cm. Peroral cholangioscopy with intraductal lithotripsy achieved an overall stone fragmentation success of 91.2 % (95 %CI 88.1 % – 93.6 %; I
2 = 63.2 %) with an average of 1.3 [SD 0.6] lithotripsy sessions performed. Complete single-session fragmentation success was 76.9 % (95 %CI 71.6 % – 81.4 %; I
2 = 74.3 %). The adverse events rate was 8.9 % (95 %CI 6.5 % – 12.2 %; I
2 = 60.6 %). Mean procedure time for peroral cholangioscopy was 67.1 (SD 21.4) minutes. There was no difference in overall fragmentation rate or adverse events; however, laser lithotripsy was associated with a higher single-session fragmentation rate and shorter procedure time compared with electrohydraulic lithotripsy.

Conclusions Peroral cholangioscopy with intraductal lithotripsy appears to be a relatively safe and effective modality for difficult biliary stones.
Endoscopic filling with polyglycolic acid sheets and fibrin glue of persistent fistula after esophagectomy
Authors: Tashiro Kousei , Takeno Shinsuke , Kawano Fumiaki , Kitamura Eiji , Hamada Rouko , Ikenoue Makoto , Munakata Shun , Nanashima Atsushi , Nakamura Kunihide
Published: June 2020

Background Treatment of anastomotic leakage in reconstruction after esophagectomy remains challenging. This report presents a new endoscopic filling method for persistent fistula after failure of conservative treatment of leakage caused by anastomotic insufficiency.

Methods 10 of 14 patients, in whom post-esophagectomy leakage had failed to resolve after 2 weeks of conservative treatment, underwent endoscopic filling with polyglycolic acid (PGA) sheet and fibrin glue into the anastomotic leakage site, using a delivery tube and endoscopic catheter, respectively.

Results Each patient underwent jejunostomy, to secure nutrition. The leakage was resolved in all 10 patients. The mean number of PGA – fibrin glue procedures was 1.7. The mean period from the first application to the resumption of oral intake was 31.6 days, from the final application it was 14.7 days.

Conclusions The reported filling method offers a new endoscopic approach for persistent fistula after esophagectomy when conservative treatment of leakage has failed.
Usefulness of mean number of adenomas per positive screenee for identifying meticulous endoscopists among those who achieve acceptable adenoma detection rates
Authors: Aniwan Satimai , Vanduangden Kunvadee , Kerr Stephen J. , Wisedopas Naruemon , Kongtab Natanong , Kullavanijaya Pinit , Rerknimitr Rungsun
Published: June 2020

Background Adenoma detection rate (ADR) is a quality indicator for colonoscopy. However, many missed adenomas have subsequently been identified after colonoscopies performed by endoscopists with ADR ≥ 25 %. Adenomas per positive participant (APP; mean number of adenomas detected by an endoscopist among screenees with positive findings) correlates well inversely with adenoma miss rate. This study aimed to evaluate whether APP added additional information on the detection rate for advanced adenomas (AADR) and proximal adenomas (pADR) and among endoscopists with acceptable ADRs (≥ 25 %).

Methods A total of 47 endoscopists performed 7339 screening colonoscopies that were retrospectively reviewed. Using a cutoff APP value of 2.0, endoscopist performance was classified as high or low APP. Endoscopist ADRs were also classified as acceptable (25 % – 29 %), high standard (30 % – 39 %) and aspirational (≥ 40 %). Generalized linear models were used to assess the relationship between AADR or pADR, and ADR and APP, after adjusting for potential confounders.

Results After adjusting for endoscopist performance and patient characteristics, endoscopists with high APP had a significant 2.1 percentage point increase in AADR (95 %CI 0.3 to 3.9; P = 0.02) and a 2.1 percentage point increase in pADR (95 %CI – 0.8 to 5.1; P = 0.15) compared to endoscopists with low APP. In total, 11 (24 %), 18 (38 %), and 18 (38 %) endoscopists were classified as having acceptable, high standard, and aspirational ADRs, respectively. APP values higher than the cutoff were found in 18 %, 44 %, and 72 % of endoscopists with acceptable, high standard, and aspirational ADRs, respectively (P = 0.02).

Conclusion APP is helpful for identifying more meticulous endoscopists who can detect a greater number of advanced adenomas. Endoscopists who achieved an only acceptable ADR had the lowest APP.
Accelerating Electrochemical Synthesis through Automated Flow: Efficient Synthesis of Chalcogenophosphites
Authors: Wirth Thomas , Amri Nasser
Published: June 2020

Integrated electrochemical reactors in automated flow systems have been utilised for chalcogenophosphite formations. Multiple electrochemical reactions can be performed using a programmed sequence in a fully autonomous way. Differently functionalised chalcogenophosphites have been efficiently synthesised in short reaction times.
Radical-Hydroboration-Involved One-Pot Synthesis of Boron-Handled Glycol Derivatives
Authors: Zhang Feng-Lian , Wang Yi-Feng , Zhuang Bi-Yang , Jin Ji-Kang
Published: June 2020

A one-pot two-step protocol for the direct synthesis of boron-handled glycol derivatives is reported. The procedure starts by an NHC–boryl-radical-promoted regioselective hydroboration of glycol-protected cinnamaldehydes. After that, the reaction mixture is treated with pinacol in the presence of HCl, leading to the direct formation of pinacol boronate handled glycol monoalkyl ethers. In this acid-triggered conversion, a reductive ring-opening of glycol-derived acetal moiety takes place, during which an NHC–borane unit serves as the hydride source.
Bio-inspired Functionalized Pyrrole-Pyridone Ensembles: Synthesis on the Platform of Acylethynylpyrroles
Authors: Trofimov Boris A. , Saliy Ivan V. , Gotsko Maxim D. , Sobenina Lyubov N. , Ushakov Igor A.
Published: June 2020

An efficient synthesis of pharmacologically oriented, functionalized pyrrole-pyridone ensembles by the reaction of available acylethynylpyrroles with methylene active amides in almost quantitative yields has been implemented. The cyclocondensation proceeds smoothly at room temperature in a KOH/DMSO superbase suspension.
Sulfuryl Fluoride Promoted Thiocyanation of Alcohols: A Practical Method for Preparing Thiocyanates
Authors: Ding Chengrong , Zhang Guofu , Xuan Lidi , Zhao Yiyong
Published: June 2020

A novel SO2F2-promoted thiocyanation method for the one-step synthesis of thiocyanates through C–O bond cleavage of readily available alcohols with ammonium thiocyanate as the thiocyanating agent was developed. The method avoids the use of additional catalyst, and a variety of (hetero)arene, alkene and aliphatic alcohols reacted with high efficiency in ethyl acetate under mild conditions to afford the corresponding thiocyanates in excellent to quantitative yields with broad functional-group compatibility.
Synthetic Approach to Fused Azasultams with 1,2,4-Thiadiazepine Framework
Authors: Milokhov Demyd S. , Hys Vasyl Y. , Volovenko Olesya B. , Konovalova Irina S. , Shishkina Svitlana V. , Volovenko Yulian M.
Published: June 2020

Synthetic approach to fused azasultams with 1,2,4-thiadi­azepine framework via base promoted protocols has been developed. 1H-Azole-2-carboxylates and N-(chloromethyl)-N-methylmethanesulfonamide were used as ambiphilic building blocks in the one-pot and two-step reaction sequences. Chemical behavior of the obtained azasultams in reactions with amines, hydrazine, DMFDMA, and NaBH4 was investigated. An enamino ketone derived from an azasultam was exploited in the synthesis of new pyrazole and pyrimidine heterocycles.
Europium-Catalyzed Intramolecular Addition of Carboxylic Acid to Nonactivated Alkenes: An Efficient Route to Aryl-Substituted γ-Butyrolactone
Authors: Bera Mrinal K. , Bandyopadhyay Manas , Nayak Abhijit
Published: June 2020

Europium(III)triflate has been proved to be an effective catalyst for intramolecular cyclization of aryl-substituted carboxylic acid to afford arylated γ-butyrolactone. Various attractive features, such as broad substrate scope, a wide range of functional group tolerance, operational simplicity, complete atom economy, and good-to-excellent yields have made this new protocol more appealing. Moreover, this method provides a practical alternative to the existing catalysts.
Solvent-Controlled Divergent Syntheses of Polycyclic N-Fused Heteroaromatics
Authors: Kim Ikyon , Dagar Anuradha , Joshi Dirgha Raj
Published: June 2020

Due to a growing interest in aza-fused polyaromatic systems among various sciences, enormous attention has been continuously paid to design and synthesize novel chemotypes of N-fused hetero­cycles. During the course of continued efforts in this line, it was found that divergent access to new polycyclic N-fused heteroaromatics was enabled by choice of reaction solvent. Described herein are solvent-controlled selective approaches to three novel N-fused azacycles, benzo-[d]imidazole-pyrrolo[1,2-a]pyrazine hybrids, under mild conditions. The plausible reaction mechanism for each class of compound is suggested as well.
Synthesis of Two Novel Mixed Bifunctional Chelating Agents: DO2AP(tBu)4 and DO3AP(tBu)4
Authors: Lattuada Luciano , Giovenzana Giovanni B. , Travagin Fabio , Biondi Luca
Published: June 2020

A convenient synthesis of two novel macrocyclic bifunctional chelating agents (BFCAs), formally derived from the well-known ligands DO3A and DOTA by selective replacement of one carboxymethyl side arm with a phosphonomethyl residue, is reported.
Primary Central Nervous System Lymphoma Presenting as Parkinsonism with Atypical MRI Findings and Elevated 14-3-3 Protein
Authors: Nagarajan Elanagan , Yerram Sushma Y. , Digala Lakshmi P. , Bollu Pradeep C.
Published: June 2020

Primary central nervous system lymphoma (PCNSL) is a rare neoplasm with an incidence of 2 to 3% of all CNS malignancies. The diagnosis can be challenging, especially with atypical presentations. Movement disorders can be one of the rare presentations of PCNSL. Here, we present an unusual case of gradually progressing Parkinsonism with an elevation of cerebrospinal fluid (CSF) 14–3-3 protein and atypical imaging findings found to have PCNSL. A 76-year-old female patient presented with gait and intermittent speech difficulty. Initial workup revealed a contrast-enhancing lesion in the bilateral putamen and head of caudate without any mass effect. Her symptoms were rapidly progressed over 6 months and presented with mild dysarthria, bradykinesia, mild rigidity, and reduced left arm swinging. These features were consistent with Parkinsonism. The repeat imaging showed the progression of hyperintensities in the bilateral putamen. The patient underwent a stereotypic biopsy of the right caudate nucleus, which revealed PCNSL. She was treated with high-dose methotrexate and is currently in remission. Diagnosis of movement disorders remains clinical and rapid progression of symptoms, and atypical presentation must warrant further imaging and workup.
Role of Proton Beam Therapy in Current Day Radiation Oncology Practice
Authors: Saini Gagan , Shukla Rashmi , Sood Kanika S. , Shukla Sujit K. , Chandra Ritu
Published: June 2020

Proton beam therapy (PBT), because of its unique physics of no–exit dose deposition in the tissue, is an exciting prospect. The phenomenon of Bragg peak allows protons to deposit their almost entire energy towards the end of the path of the proton and stops any further dose delivery. Braggs peak equips PBT with superior dosimetric advantage over photons or electrons because PBT doesn’t traverse the target/body but is stopped sharply at an energy dependent depth in the target/body. It also has no exit dose. Because of no exit dose and normal tissue sparing, PBT is hailed for its potential to bring superior outcomes. Pediatric malignancies is the most common malignancy where PBT have found utmost application. Nowadays, PBT is also being used in the treatment of other malignancies such as carcinoma prostate, carcinoma breast, head and neck malignancies, and gastrointestinal (GI) malignancies. Despite advantages of PBT, there is not only a high cost of setting up of PBT centers but also a lack of definitive phase-III data. Therefore, we review the role of PBT in current day practice of oncology to bring out the nuances that must guide the practice to choose suitable patients for PBT.
Gyrokinetic understanding of the edge pedestal transport driven by resonant magnetic perturbations in a realistic divertor geometry
Authors: Hager R. , Chang C. S. , Ferraro N. M. , Nazikian R.
Published: June 2020

Self-consistent simulations of neoclassical and electrostatic turbulent transport in a DIII-D H-mode edge plasma under resonant magnetic perturbations (RMPs) have been performed using the global total-f gyrokinetic particle-in-cell code x-point gyrokinetic code (XGC), in order to study density pump-out and electron heat confinement. The RMP field is imported from the extended magneto-hydrodynamics code M3D-C1, taking into account the linear two-fluid plasma response. With both neoclassical and turbulence physics considered together, the XGC simulation reproduces two key features of experimentally observed edge transport under RMPs: increased radial particle transport in the pedestal region that is sufficient to account for the experimental pump-out rate and suppression of the electron heat flux in the steepest part of the edge pedestal. In the simulation, the density fluctuation amplitude of modes moving in the electron diamagnetic direction increases due to interaction with RMPs in the pedestal shoulder and outward, while the electron temperature fluctuation amplitude decreases.
Fully resolved simulation of a shockwave interacting with randomly clustered particles via a ghost-cell immersed boundary method
Authors: Xiao Wei , Mao Chaoli , Jin Tai , Luo Kun , Fan Jianren
Published: June 2020

Fully resolved direct numerical simulations are performed to investigate the interaction between a planar shockwave and 300 randomly clustered particles. The particle interfaces are captured with the ghost-cell immersed boundary method. Four cases of different shock Mach numbers up to 6.0 are investigated with a relatively high volume fraction of 14.7% of clustered particles. Results show that the reflected shocks form a planar shockwave propagating upstream, with its velocity decreasing with the increase in Mach number. In small Mach number cases, the transmitted shock remains planar and exceeds its original propagating speed. In high Mach number cases, the transmitted shock is highly curved and slowed down. The peak drag coefficients of all particles could exhibit a linear correlation with the streamwise location. The lift force coefficients could become similar to or even larger than the drag coefficients when the particles reside in post-shock regions. The peak lift force coefficients are the smallest for the first and last rows, and highest in the first half part of clusters, which is due to different mechanisms. The transverse effects of shock–cluster interaction are stronger in higher Mach number cases. This result indicates that the transverse force could not be ignored in a particle cluster with a relatively high volume fraction, especially when the Mach number is high. Fluctuating flow quantities indicate that the increase in Mach number could enhance the fluctuations in the transverse direction and reduce the streamwise mean velocity, resulting in stronger fluctuating fields compared with the mean flows.
Overtaking collisions of double layers and solitons: Tripolar structures and dynamical polarity switches
Authors: Olivier C. P. , Verheest F.
Published: June 2020

Overtaking collisions between double layers and solitons are investigated through the numerical simulation of the Gardner equation that governs small-amplitude double layers. The results show that the double layer emerges unaffected after the completion of the collision. However, the soliton that emerges from the collision has the opposite polarity of the soliton prior to the collision. In addition, it is shown that a transient tripolar electric field structure forms during the collision. Possible applications to spacecraft observation of electrostatic solitary waves are briefly discussed.
Large second-order nonlinearity in asymmetric metallic quantum wells
Authors: Bopp Steven Edward , Qian Haoliang , Li Shilong , Liu Zhaowei
Published: June 2020

Investigation of new plasmonic material platforms with large optical nonlinearity is crucial for the continued development of nonlinear optics and its applications. Here, we report an enhanced second-order nonlinear effect in metallic quantum wells (QWs), where the intersubband transition plays a dominant role. Centrosymmetry in these metallic QWs is broken by forming multilayers with chemically and structurally distinct barrier oxides above and below a metal nanofilm. For Au-based QWs, we show that a large χ(2) around 229.6 pm/V in the near infrared was achieved in an asymmetric metallic QW of SiO2|Au|HfO2 on a fused silica substrate.
Electro-drop bouncing in low-gravity
Authors: Schmidt Erin S. , Weislogel Mark M.
Published: June 2020

We investigate the dynamics of spontaneous jumps of water drops from electrically charged nonwetting dielectric substrates during sudden step reductions in the gravity level. In the free-fall environment of a drop tower, the dynamics of drops subject to external electric fields are dominated by the Coulombic force instead of gravity. These forces lead to a drop bouncing behavior similar to well-known terrestrial phenomena though occurring for much larger drops (∼0.5 ml). We provide a one-dimensional model for the phenomenon, its scaling, and asymptotic estimates for drop time-of-flight in two regimes: at short-times close to the substrate when drop inertia balances the Coulombic force due to net free charge and image charges in the dielectric substrate, and at long-times far from the substrate when drop inertia balances free charge Coulombic force and drag. In both regimes, the dimensionless electrostatic Euler number Eu, which is a ratio of inertia to electrostatic force, appears as a key parameter.
An experimental study of a nearly perfect absorber made from a natural hyperbolic material for harvesting solar energy
Authors: Wang Zhaolong , Yang Peiyan , Qi Genggeng , Zhang Zhuomin M. , Cheng Ping
Published: June 2020

In this paper, the absorptance of a broadband nearly perfect absorber, consisting of a metal surface covered by a rough Bi2Te3 layer, was measured and the optical properties of such a sample are calculated by using the finite-difference time-domain (FDTD) method. The results show that the measured absorptance of a designed sample with a roughness of 794 nm is larger than 0.94 in the wavelength range of 380–1800 nm, which can also be validated and explained by the calculated results. However, the absorptance of the absorber is affected by the morphology of the Bi2Te3 layer, including the roughness and the bottom width of the Bi2Te3 nanostructures. It is shown that the calculated absorptance of the absorber increases with the increasing roughness of the Bi2Te3 layer made of sharp nanostructures (with increasing cross section in the direction of incident light) if the bottom width of the Bi2Te3 nanostructures is fixed. However, the absorptance of the absorber decreases with the increase of the bottom width of Bi2Te3 nanostructures for absorbers with the same roughness. The underlying mechanisms for perfect absorbers are owing to the slow-light effect and gradient index effect, which require tall nanostructures with suitable bottom width for the total absorption of electromagnetic (EM) waves in the solar wavelength range. Furthermore, different samples were fabricated by using an electrochemical reaction method, and the measured absorption properties of these samples are shown in good agreement with calculated results.
Diagnosis of electron temperature and density in the early stage of laser-produced Si plasma expansion
Authors: Wang Kaiping , Su Maogen , Cao Shiquan , Ma Pengpeng , Sun Duixiong , Min Qi , Dong Chenzhong
Published: June 2020

We measured time-resolved spectra of laser-produced plasma of Si in a vacuum at the early phase evolution (30–100 ns) and found clear signs of spectral line broadening. Based on the measured line intensities of Si2+ and Si3+ ions, the Saha–Boltzmann method is used to diagnose the electron temperature. The Stark broadening of different high-charge ion lines is combined with a modified Griem semi-empirical formula to diagnose the electron density of Si plasma in the early evolutionary stage. The effects of self-absorption, natural broadening, and Doppler broadening on the spectral profiles were evaluated. We also conducted experiments to verify that current experimental conditions satisfied the local thermodynamic equilibrium conditions. Finally, time evolutions for the electron temperature and electron density in the early stage of plasma evolution were obtained.
High-resolution imaging of Rydberg atoms in optical lattices using an aspheric-lens objective in vacuum
Authors: Shen Chuyang , Chen Cheng , Wu Xiao-Ling , Dong Shen , Cui Yue , You Li , Tey Meng Khoon
Published: June 2020

We present a high-resolution, simple, and versatile system for imaging ultracold Rydberg atoms in optical lattices. The imaging objective is a single aspheric lens [with a working distance of 20.6 mm and a numerical aperture (NA) of 0.51] placed inside the vacuum chamber. Adopting a large-working-distance lens leaves room for electrodes and electrostatic shields to control electric fields around Rydberg atoms. With this setup, we achieve a Rayleigh resolution of 1.10 μm or 1.41λ (λ = 780 nm), limited by the NA of the aspheric lens. For systems of highly excited Rydberg states with blockade radii greater than a few μm, the resolution achieved is sufficient for studying many physical processes of interest.
Thermovoltage in quantum dots with attractive interaction
Authors: Schulenborg Jens , Wegewijs Maarten R. , Splettstoesser Janine
Published: June 2020

We study the linear and nonlinear thermovoltage of a quantum dot with effective attractive electron–electron interaction and weak, energy-dependent tunnel coupling to electronic contacts. Remarkably, we find that the thermovoltage shows signatures of repulsive interaction, which can be rationalized. These thermovoltage characteristics are robust against large potential and temperature differences well into the nonlinear regime, which we expect can be demonstrated in current state-of-the-art experiments. Furthermore, under nonlinear operation, we find extended regions of large power production at efficiencies on the order of the Curzon–Ahlborn bound interrupted only by a characteristic sharp dip.
Magnetic properties of Co/Ni-based multilayers with Pd and Pt insertion layers
Authors: Heigl M. , Wendler R. , Haugg S. D. , Albrecht M.
Published: June 2020

In this study, the influence of Pd and Pt insertion layers in Co/Ni multilayers (MLs) on their magnetic properties, e.g., magnetic anisotropies, saturation magnetization, coercivity, magnetic domain size, and Curie temperature, is investigated. We compare three series of [Co/Ni/X]N ML systems (X=Pd, Pt, no insertion layer), varying the individual Co layer thickness as well as the repetition number N. All three systems behave very similarly for the different Co layer thicknesses. For all systems, a maximum effective magnetic anisotropy was achieved for MLs with a Co layer thickness between 0.15 and 0.25 nm. The transition from an out-of-plane to an in-plane system occurs at about 0.4 nm of Co. While [Co(0.2 nm)/Ni(0.4 nm)]N MLs change their preferred easy magnetization axis from out-of-plane to in-plane after six bilayer repetitions, insertion of Pd and Pt results in an extension of this transition beyond 15 repetitions. The maximum effective magnetic anisotropy was more than doubled from 105 kJ/m3 for [Co/Ni]3 to 275 and 186 kJ/m3 for Pt and Pd, respectively. Furthermore, the insertion layers strongly reduce the initial saturation magnetization of 1100 kA/m of Co/Ni MLs and lower the Curie temperature from 720 to around 500 K.
Modeling voltammetry curves for proton coupled electron transfer: The importance of nuclear quantum effects
Authors: Coffman Alec J. , Dou Wenjie , Hammes-Schiffer Sharon , Subotnik Joseph E.
Published: June 2020

We investigate rates of proton-coupled electron transfer (PCET) in potential sweep experiments for a generalized Anderson–Holstein model with the inclusion of a quantized proton coordinate. To model this system, we utilize a quantum classical Liouville equation embedded inside of a classical master equation, which can be solved approximately with a recently developed algorithm combining diffusional effects and surface hopping between electronic states. We find that the addition of nuclear quantum effects through the proton coordinate can yield quantitatively (but not qualitatively) different IV curves under a potential sweep compared to electron transfer (ET). Additionally, we find that kinetic isotope effects give rise to a shift in the peak potential, but not the peak current, which would allow for quantification of whether an electrochemical ET event is proton-coupled or not. These findings suggest that it will be very difficult to completely understand coupled nuclear–electronic effects in electrochemical voltammetry experiments using only IV curves, and new experimental techniques will be needed to draw inferences about the nature of electrochemical PCET.
Anomalous low energy phonon dispersion in bulk silicon-germanium observed by inelastic x-ray scattering
Authors: Yokogawa R. , Takeuchi H. , Arai Y. , Yonenaga I. , Tomita M. , Uchiyama H. , Watanabe T. , Ogura A.
Published: June 2020

We report on an anomalous mode distinct from both optical and acoustic modes in phonon dispersion curves of bulk Si1−xGex alloy with x taking the values of 0.16, 0.32, 0.45, and 0.72. The anomalous mode at approximately 13 meV was observed directly using inelastic x-ray scattering along the Γ–X ([00q]) direction. The phonon dispersion relations of the anomalous mode indicate that there was no momentum dependence, similar to those of the longitudinal and transverse optical modes (Ge–Ge, Si–Ge, and Si–Si modes). In contrast to the acoustic and optical phonon modes, the energy of the anomalous mode shows no Ge fraction dependence. The molecular dynamics simulation corroborates that the Ge–Ge pairs or Ge atom clusters, which are surrounded by Si atoms, provide the anomalous mode, which is unique to the alloy structure. It has been suggested that such a localized vibration mode with no propagation significantly affects the acoustic modes, leading to low thermal conductivity in the SiGe alloy.
Statistical theory of helical turbulence
Authors: Deußen B. , Dierkes D. , Oberlack M.
Published: June 2020

A statistical theory for homogeneous helical turbulence is developed under the condition of strong symmetry. The latter describes reflectional symmetry in planes through and normal to the helical unit vector eξ, which can be achieved by demanding that the mean velocity is zero. The two-point velocity correlation, the pressure–velocity correlation, and the two-point triple correlation are expressed by scalar functions in the helical unit vector system. By introducing the continuity equation for the correlations, the number of unknown functions can be reduced to such an extent that ultimately, a single scalar transport equation remains. Furthermore, a two-point Poisson equation is derived to express the pressure–velocity correlation in terms of the triple correlation. From the two-point version of the transport equation, the single-point limit is derived. Using the single-point equation, it can be shown that all velocity components are generally non-zero. Therefore, it is concluded that the phenomenon of vortex stretching is present in the helical coordinate system. Finally, the theory of axisymmetric turbulence is derived as a limiting case of helical turbulence to show consistency with former work.