bluuebunny/crossref_metadata_2025 huggingface dataset:
Clay-catalyzed ozonation of endocrine-disrupting compounds in solvent-free media – to better understand soil catalytic capacity
Authors: Boudissa Farida , Zekkari Meriem , Arus Vasilica-Alisa , Ouargli-Saker Rachida , Nabil Bouazizi , Roy René , Azzouz Abdelkrim
Published: September 2020

An original approach never followed so far allowed correlating the basicity and hydrophilic character of clay catalysts with surface interaction with 17α-Ethinylestradiol (EE2) during ozonation in water.
Metal organic frameworks decorated with free carboxylic acid groups: topology, metal capture and dye adsorption properties
Authors: Ahamad M. Naqi , Khan M. Shahnawaz , Shahid M. , Ahmad Musheer
Published: September 2020

Elaborating the role of uncoordinated carboxylic acid functions in MOFs in post synthetic modification (PSM) through metal capture and hence in tuning dye adsorption properties.
Nano-localized single-cell nano-electroporation
Authors: Santra Tuhin Subhra , Kar Srabani , Chang Hwan-You , Tseng Fan-Gang
Published: September 2020

We demonstrated nano-electroporation technique to create transient nano-holes at single or multiple nano-localized positions of a single-cell for a highly efficient intracellular delivery with high cell viability.
Reduction of Taylor–Aris dispersion by lateral mixing for chromatographic applications
Authors: Westerbeek Eiko Y. , Bomer Johan G. , Olthuis Wouter , Eijkel Jan C. T. , De Malsche Wim
Published: September 2020

We demonstrate a method to reduce Taylor–Aris dispersion by lateral mixing in a newly designed silicon AC-electroosmotic flow mixer and with this improve a reverse-phase chromatographic separation of coumarins.
Sulfonamide-containing copper(ii) complexes: new insights on biophysical interactions and antibacterial activities
Authors: Nakahata Douglas H. , de Paiva Raphael E. F. , Lustri Wilton R. , Corbi Pedro P.
Published: September 2020

Cu–(N^N)–sulfonamide complexes are selective metallonucleases that bind tightly to BSA with no protease activity. These compounds have promising antibacterial properties.
Determination of the correlation between the structure and dynamics of deflazacort by solid state NMR measurements
Authors: Dey Krishna Kishor , Ghosh Manasi
Published: September 2020

The correlation between the structure and dynamics of glucocorticoid deflazacort is determined by a 2DPASS CP-MAS SSNMR experiment and 13C spin–lattice relaxation time by a Torchia CP experiment.
Influence of sonication on the physicochemical and biological characteristics of selenium-substituted hydroxyapatites
Authors: Padmanabhan Varun Prasath , Kulandaivelu Ravichandran , Venkatachalam Vijayaraj , Veerla Sarath Chandra , Mohammad Faruq , Al-Lohedan Hamad A. , Oh Won Chun , Schirhagl Romana , Obulapuram Prasanna Kumar , Hoque Md Enamul , Sagadevan Suresh
Published: September 2020

Selenium-doped hydroxyapatite composite formed by the sonication technique investigated to have superior properties that are specifically advantageous in the tissue engineering, growth, and regeneration sector.
Planar tetracoordinate carbon molecules with 14 valence electrons: examples of CBe4Mnn−2 (M = Li, Au; n = 1–3) clusters
Authors: Guo Jin-Chang , Feng Lin-Yan , Zhai Hua-Jin
Published: September 2020

Planar tetracoordinate carbon species are viable with 14 valence electrons, which violate the 18-electron rule. Chemical bonding around the C center is governed by double 2π/6σ aromaticity.
Exciton manipulation in rippled transition metal dichalcogenides
Authors: Long Chen , Dai Ying , Li Jianwei , Jin Hao
Published: September 2020

Due to the introduction of morphological control, the excitons are pushed towards the regions with higher stress. In addition, combined with intrinsic electric field, a spatial separation of photo-excited electrons and holes is achieved.
Correction: Fine tuning of ferromagnet/antiferromagnet interface magnetic anisotropy for field-free switching of antiferromagnetic spins
Authors: Ślęzak M. , Dróżdż P. , Janus W. , Nayyef H. , Kozioł-Rachwał A. , Szpytma M. , Zając M. , Menteş T. O. , Genuzio F. , Locatelli A. , Ślęzak T.
Published: September 2020

Correction for ‘Fine tuning of ferromagnet/antiferromagnet interface magnetic anisotropy for field-free switching of antiferromagnetic spins’ by M. Ślęzak et al., Nanoscale, 2020, DOI: 10.1039/d0nr04193a.
Photocycloreversions within single polymer chains
Authors: Liu Modan , Wenzel Wolfgang , Frisch Hendrik
Published: September 2020

Reversible photocycloadditions hold great potential to control formation and fissure of bonds. However, the wavelength selective addressability of cycloaddition and -reversion was found to be lost in the confined environment of single polymer chains.
Snapback‐free and low‐loss SAG‐LIGBT with self‐driving auxiliary gate
Authors: Chen Weizhong , Li Shun , Huang Yao , Huang Yi , Han ZhengSheng
Published: September 2020

A novel snapback‐free and low‐loss shorted‐anode lateral insulated bipolar transistor (SA‐LIGBT) based on silicon on insulator with self‐driving auxiliary gate (SAG) in the anode is proposed, named as SAG‐LIGBT. The SAG is characterised by metal oxide semiconductor (MOS) structure in the anode, and the gate of the MOS is shorted with the anode electrode, thus self‐driving without extra gate signal is achieved. At anode voltage V A  = 0, the P‐base serving as a barrier to hinder electrons flowing into the N + anode. At V A  = V on of the forward conduction, the P‐base is depleted to intrinsic, and the anode resistance R SA is increased from R P‐base to R intrinsic. At V A  = V bus of the turn‐off state, the P‐base is fully depleted and an electron accumulation layer is formed under the SiO2, thus the R SA is decreased from R intrinsic to R n‐channel to provide a low‐resistance path for electron current. Consequently, the device not only eliminates the snapback effect but also reduces the turn‐off energy loss E off. Therefore, a better trade‐off is obtained between V on and E off. At the same V on, the E off of SAG‐LIGBT is decreased by 57 and 66% compared with separated shorted‐anode LIGBT (SSA‐LIGBT) and SA‐LIGBT, respectively. Moreover, the SAG‐LIGBT exhibits the shorter T off of 80 ns than the SSA‐LIGBT and vertical P‐collector and N‐buffer LIGBT at J A  = 100 A/cm2.
Constraining the orientation of the spin axes of extrasolar minor bodies 1I/2017 U1 (‘Oumuamua) and 2I/Borisov
Authors: de la Fuente Marcos C. , de la Fuente Marcos R.
Published: September 2020

Context.The orientation of the spin axis of a comet is defined by the values of its equatorial obliquity and its cometocentric longitude of the Sun at perihelion. These parameters can be computed from the components of the nongravitational force caused by outgassing if the cometary activity is well characterized. The trajectories of known interstellar bodies passing through the Solar System show nongravitational accelerations.

Aims.The spin-axis orientation of 1I/2017 U1 (‘Oumuamua) remains to be determined; for 2I/Borisov, the already released results are mutually exclusive. In both cases, the values of the components of the nongravitational force are relatively well constrained. Here, we investigate – within the framework of the forced precession model of a nonspherical cometary nucleus – the orientation of the spin axes of ‘Oumuamua and 2I/Borisov using public orbit determinations that consider outgassing.

Methods.We applied a Monte Carlo simulation using the covariance matrix method together with Monte Carlo random search techniques to compute the distributions of equatorial obliquities and cometocentric longitudes of the Sun at perihelion of ‘Oumuamua and 2I/Borisov from the values of the nongravitational parameters.

Results.We find that the equatorial obliquity of ‘Oumuamua could be about 93°, if it has a very prolate (fusiform) shape, or close to 16°, if it is very oblate (disk-like). Different orbit determinations of 2I/Borisov gave obliquity values of 59° and 90°. The distributions of cometocentric longitudes were in general multimodal.

Conclusions.Our calculations suggest that the most probable spin-axis direction of ‘Oumuamua in equatorial coordinates is (280°, +46°) if very prolate or (312°, −50°) if very oblate. Our analysis favors a prolate shape. For the orbit determinations of 2I/Borisov used here, we find most probable poles pointing near (275°, +65°) and (231°, +30°), respectively. Although our analysis favors an oblate shape for 2I/Borisov, a prolate one cannot be ruled out.
Gravitational Lensing and Dynamics (GLaD): combined analysis to unveil properties of high-redshift galaxies
Authors: Chirivì G. , Yıldırım A. , Suyu S. H. , Halkola A.
Published: September 2020

The dynamical modelling of integral field unit (IFU) stellar kinematics is a powerful tool to unveil the dynamical structure and mass build-up of galaxies in the local Universe, while gravitational lensing is nature’s cosmic telescope to explore the properties of galaxies beyond the local Universe. We present a new approach, which unifies dynamical modelling of galaxies with the magnification power of strong gravitational lensing, to reconstruct the structural and dynamical properties of high-redshift galaxies. By means of axisymmetric Jeans modelling, we create a dynamical model of the source galaxy, assuming a surface brightness and surface mass density profile. We then predict how the source’s surface brightness and kinematics would look when lensed by the foreground mass distribution and compare with the mock observed arcs of strong gravitational lensing systems. For demonstration purposes, we created and also analysed mock data of the strong lensing system RX J1131−1231. By modelling both the lens and source, we recover the dynamical mass within the effective radius of strongly lensed high-redshift sources within 5% uncertainty, and we improve the constraints on the lens mass parameters by up to 50%. This machinery is particularly well-suited for future observations from large segmented-mirror telescopes, such as the James Webb Space Telescope, which will yield high sensitivity and angular-resolution IFU data for studies on distant and faint galaxies.
The near-infrared companion to HD 94660 (=KQ Vel)
Authors: Schöller M. , Hummel C. A. , Hubrig S. , Kurtz D. W. , Mathys G. , Robrade J. , Järvinen S. P.
Published: September 2020

Context. The Bp star HD 94660 is a single-lined spectroscopic binary. Some authors have suggested that the unseen companion of at least 2 M⊙ may be a compact object.

Aims. We intend to study this multiple system in detail, especially to learn more about the thus far unseen companion.

Methods. We have collected and analyzed PIONIER (Precision Integrated-Optics Near-infrared Imaging ExpeRiment) H-band data from the Very Large Telescope Interferometer, TESS (Transiting Exoplanet Survey Satellite) visible photometric data, and X-ray observations with Chandra of HD 94660.

Results. Using PIONIER, we were able to detect the companion to HD 94660, which is absent from high quality spectra at visible wavelengths, with a magnitude difference of 1.8 in the H band at a separation of 18.72 mas. The TESS light curve shows variations with a period of 2.1 d and also flaring. The Chandra spectrum is well described by emission from hot thermal plasma, yet it might include a nonthermal component. The X-ray properties are compatible with a magnetically active companion, while it is also possible that there might be some magnetospheric contributions from the primary.

Conclusions. We can rule out that the companion to HD 94660 is a compact source. It is also very unlikely that this companion is a single star, as the estimated mass of more than 2 M⊙, the magnitude difference of 1.8 in the H band, and its nondetection in visible spectra are difficult to realize in a single object. One alternative could be a pair of late F stars, which would also be responsible for the detected photometric variations. Interferometric observations over the full binary orbit are necessary to determine the real mass of the companion and to add constraints on the overall geometry of the system.
KY electroproduction at CLAS12
Authors: Lanza Lucilla
Published: September 2020

An experimental program has been approved at the Thomas Jefferson National Accelerator Facility to measure the (ep,e’K+)Y reactions using the CLAS12 setup in Hall B. Data have been obtained using a 7.5 GeV electron beam, impinging upon a liquid hydrogen target in the CLAS12 center. Scattered electrons have been detected in an angle range of 2.5° to 4.5° by the Forward Tagger (FT) and at angles greater than 5° in the CLAS12 Forward Detector, allowing to measure the KY electroproduction differential cross section and to probe theQ2evolution of the N* resonances electrocouplings in theQ2range from 0.05GeV2to 3GeV2. The study of theQ2dependence of the electrocouplings will provide a crucial tool to investigate the possible hybrid nature of the N* resonances. Preliminary results from CLAS12 data are compared with simulated data using a realistic Gent Regge plus resonance event generator
Towards a theory of baryon resonances
Authors: Meißner Ulf-G.
Published: September 2020

In this talk, I discuss methods that allow for a systematic and model-independent calculation of the hadron spectrum. These are lattice QCD and/or its corresponding Effective Field Theories. Assorted results are shown and I take the opportunity to discuss some misconceptions often found in the literature.
Form factors for the Nucleon-to-Roper electromagnetic transition at large-Q2
Authors: Rodríguez-Quintero José , Binosi Daniele , Chen Chen , Lu Ya , Roberts Craig D. , Segovia Segovia
Published: September 2020

We report on a recent calculation of all Roper-related electromagnetic transtions form factors, cov ering the range of energies that next-to-come planned experiments are expected to map. Direct reliable cal culations were performed, within a Poincaré covariant approach of the three-body bound-state problem, up to Q2/m2N=6; approximated then by applying the Schlessinger point method and the results eventually extended up to Q2/m2N ≃12 via analytic continuation.
Teamworking in endoscopy: a human factors toolkit for the COVID-19 era
Authors: Ravindran Srivathsan , Matharoo Manmeet , Coleman Mark , Marshall Sarah , Healey Chris , Penman Ian , Thomas-Gibson Siwan
Published: September 2020

Background Endoscopy services have had to rapidly adapt their working practices in response to COVID-19. As recovery of endoscopy services proceeds, our workforce faces numerous challenges that can impair effective teamworking. We designed and developed a novel toolkit to support teamworking in endoscopy during the pandemic.

Methods A human factors model was developed to understand the impact of COVID-19 on endoscopy teams. From this, we identified a set of key teamworking goals, which informed the development of a toolkit to support several team processes. The toolkit was refined following expert input and refinement over a 6-week period.

Results The toolkit consists of four cognitive aids that can be used to support team huddles, briefings, and debriefs, alongside techniques to optimize endoscopic nontechnical skills across the patient-procedure pathway. We describe the processes that local endoscopy units can employ to implement this toolkit.

Conclusion A toolkit of cognitive aids, based on human factors principles, may be useful in supporting teams, helping them adapt to working safely in the era of COVID-19.
Educational interventions are associated with improvements in colonoscopy quality indicators: a systematic review and meta-analysis
Authors: Causada-Calo Natalia S. , Gonzalez-Moreno Emmanuel I. , Bishay Kirles , Shorr Risa , Dube Catherine , Heitman Steven J. , Hilsden Robert J. , Rostom Alaa , Walsh Catharine , Anderson John T. , Keswani Rajesh N. , Scaffidi Michael A. , Grover Samir C. , Forbes Nauzer
Published: September 2020

Background and study aims The quality of screening-related colonoscopy depends on several physician- and patient-related factors. Adenoma detection rate (ADR) varies considerably between endoscopists. Educational interventions aim to improve endoscopists’ ADRs, but their overall impact is uncertain. We aimed to assess whether there is an association between educational interventions and colonoscopy quality indicators.

Methods A comprehensive search was performed through August 2019 for studies reporting any associations between educational interventions and any colonoscopy quality indicators. Our primary outcome of interest was ADR. Two authors assessed eligibility criteria and extracted data independently. Risk of bias was also assessed for included studies. Pooled rate ratios (RR) with 95 % confidence intervals (CI) were reported using DerSimonian and Laird random effects models.

Results From 2,253 initial studies, eight were included in the meta-analysis for ADR, representing 86,008 colonoscopies. Educational interventions were associated with improvements in overall ADR (RR 1.29, 95 % CI 1.25 to 1.42, 95 % prediction interval 1.09 to 1.53) and proximal ADR (RR 1.39, 95 % CI 1.29 to 1.48), with borderline increases in withdrawal time, ([WT], mean difference 0.29 minutes, 95 % CI – 0.12 to 0.70 minutes). Educational interventions did not affect cecal intubation rate ([CIR], RR 1.01, 95 % CI 1.00 to 1.01). Heterogeneity was considerable across many of the analyses.

Conclusions Educational interventions are associated with significant improvements in ADR, in particular, proximal ADR, and are not associated with improvements in WT or CIR. Educational interventions should be considered an important option in quality improvement programs aiming to optimize the performance of screening-related colonoscopy.
Efficacy of EUS-RFA in pancreatic tumors: Is it ready for prime time? A systematic review and meta-analysis
Authors: Dhaliwal Amaninder , Kolli Sindhura , Dhindsa Banreet Singhg , Choa Jacqueline , Mashiana Harmeet Singh , Ramai Daryl , Chandan Saurabh , Bhogal Neil , Sayles Harlan , Bhat Ishfaq , Singh Shailender , Adler Douglas G.
Published: September 2020

Background and study aims Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) can be used in patients with unresectable pancreatic ductal adenocarcinoma (PDAC). We performed a systematic review and meta-analysis to evaluate the efficacy of EUS-RFA in treatment of locally advanced unresectable PDAC and other pancreatic tumors.

Patients and methods A comprehensive search was done of multiple electronic databases and conference proceedings including PubMed, EMBASE, Web of Science databases, Google Scholar and manual search of references (from inception through May 2019) to identify the studies reporting use of EUS-RFA for pancreatic lesions. The primary outcome was to evaluate technical and clinical success of the procedure. The secondary outcome was to study overall adverse events (AEs).

Results Thirteen studies reporting 165 EUS-RFA procedures on 134 patients were included. Of 134 patients, 27.94 % (38) had unresectable locally advanced PDAC, 40 % (53) had PNETs, 3 % (4) had metastasis to the pancreas and 30 % (41) had other lesions. The pooled technical success rate calculated out of the total number of procedures was 100 % (95 % CI [99.18 – 100], I2 = 0 %). The pooled clinical success rate calculated out of the total number of patients was 91.58 % (95 % CI [82.5 – 98.08], I2 = 21.5 %). The pooled overall AE rates were 14.67 % (95 % CI [4.77 – 27.46], I2 = 56.19 %) out of which abdominal pain was the most common with 9.82 % (95 % CI [3.34 – 18.24], I2 = 23.76 %). Low to moderate heterogeneity was noted.

Conclusion EUS-RFA has high technical (100 %) and clinical success (91.5 %) rates. Further multicenter trials are needed to further validate our findings.
How does per-oral endoscopic myotomy compare to Heller myotomy? The Latin American perspective
Authors: Kahaleh Michel , Tyberg Amy , Suresh Supriya , Lambroza Arnon , Gaidhane Monica , Zamarripa Felipe , Martínez Guadalupe Ma , Carames Juan C. , Moura Eduardo T. , Farias Galileu F. , Porfilio Maria G. , Nieto Jose , Rey Mario , Rodriguez Casas Fernando , Mondragón Hernández Oscar V. , Vargas-Rubio Romulo , Canadas Raul , Hani Albis , Munoz Guillermo , Castillo Bismarck , Lukashok Hannah P. , Robles-Medranda Carlos , de Moura Eduardo G
Published: September 2020

Background and study aims Both Heller myotomy (HM) and per-oral endoscopic myotomy (POEM) are efficacious therapies for achalasia. The efficacy and safety of POEM vs HM in Latin America and specifically in patients with Chagas disease is unknown.

Patients and methods Consecutive patients undergoing either HM or POEM for achalasia were included from nine Latin American centers in a prospective registry over 5 years. Technical success was defined as undergoing a successful myotomy. Clinical success was defined as achieving an Eckardt score < 3. Data on demographics, procedure info, Eckardt score, and adverse events (AEs) were collected. Student’s t test, Chi squared, and logistic regression analyses were conducted.

Results One hundred thirty-three patients were included (59 male; 44 %; mean age 47). POEM was performed in 69 patients, HM in 64 patients. A total of 35 patients had Chagas disease, 17 of 69 in the POEM group, 18 of 64 in the HM group. Both groups had significant reduction in Eckardt scores (P < 0.00001), but successful initial therapy was significantly higher in the POEM group compared to the HM group (P = 0.01304). AEs were similar in both group (17 % vs 14 %) and consisted of pneumothorax (n = 3 vs 2), bleeding requiring transfusion (n = 3 vs 2), and mediastinitis (n = 3 vs 1). Hospital stay was longer in the HM group than in the POEM group (P < 0.00001). In the Chagas subgroup, post-procedure Eckardt score in the POEM group was significantly reduced by 5.71 points (P < 0.00001) versus 1.56 points in the HM group (P = 0.042793).

Conclusion Both HM and POEM are efficacious for achalasia, but POEM was associated with higher initial therapy success and shorter hospital stay in Latin America. In Chagas patients with achalasia, POEM was significantly more effective than HM.
Clear cap-assisted luminal stenting may improve technical success in gastroduodenal and colonic obstruction
Authors: Fung Brian M. , Chen Formosa C. , Tabibian James H.
Published: September 2020

Background Luminal stenting is safe, effective, and at times the preferred method for relieving gastrointestinal obstruction. However, stent placement is not technically feasible when lesions cannot be traversed with a guidewire, resulting in the need for more invasive methods of palliation and urgent/emergent surgical intervention. In this series, we report our experience with cap-assisted stenting to improve lumen visualization in obstructed segments of the gastrointestinal tract and salvage cases that may have otherwise resulted in technical failure.

Methods A clear cap (i. e. distal attachment) was affixed to the scope tip to facilitate visualization and stenting in two cases of gastroduodenal obstruction and three cases of colonic obstruction. Indications for stent placement included malignant obstruction, diverticulitis-associated obstruction, and Crohn’s disease-associated stricture.

Results In this report, we demonstrate that use of a clear cap facilitated endoscopic stenting in challenging cases of malignant and benign gastroduodenal and colonic obstruction.

Conclusions A clear cap for endoscopic stenting can be used in cases in which standard techniques are unsuccessful or those anticipated to be technically difficult at the outset. Cases with tortuous anatomy or particularly tight, friable, or exophytic obstructive lesions may benefit most from this novel technical modification.
Recombinant Human Thyrotropin-Stimulated Radioiodine Therapy in
Patients with Multinodular Goiters: A Meta-Analysis of Randomized Controlled
Trials
Authors: Xu Chunmei , Wang Ping , Miao Huikai , Xie Tianyue , Zhou Xiaojun , Zhang Qian , Jiang Shan , Zhang Rui , Liao Lin , Dong Jianjun
Published: September 2020

A potential reduction of goiter volume (GV) of recombinant human thyrotropin
(rhTSH) on multinodular goiters (MNG) was previously reported but controversial.
Hence we conducted a meta-analysis to estimate the effect of rhTSH-stimulated
radioiodine therapy in patients with MNG. PubMed, Cochrane, CNKI, VIP, and
Wanfang databases were searched. Mean difference (MD) and odds ratios with
95% confidence intervals (95% CI) were derived by using an
inverse variance random-effects model and fixed-effects model, respectively. Six
studies (n=237) were involved in the analysis. For 12 months follow up,
high dose (>0.1 mg) of rhTSH significantly reduced GV
(MD=17.61; 95% CI=12.17 to 23.04; p<0.00001)
compared with placebo. No effective pooled results of low dose of rhTSH
(<0.1 mg) were applicable for only one study included. For 6
months follow up, the source of heterogeneity was determined by subgroup and
sensitivity analysis. High dose group showed vast improvement in GV reduction
(MD=16.62; 95% CI=1.34 to 31.90; p=0.03). The
reduction of low dose group compared with placebo was inferior to high dose
group. No available data were obtained to assess the influence of rhTSH after 36
months follow up for the only included study. Hypothyroidism incidence was
higher for rhTSH group. No publication bias was seen. High dose of rhTSH
treatment-stimulated radioactive 131I therapy after 6 months and 12
months follow up had a better effect in reducing GV, but with higher incidence
of hypothyroidism. Owing to the limited methodological quality, more clinical
researches are warranted in the future.
Recent Advances in Palladium-Catalyzed Bridging C–H Activation by Using Alkenes, Alkynes or Diazo Compounds as Bridging Reagents
Authors: Zhang Fulin , Xin Luoting , Liao Saihu , Huang Xueliang , Yu Yinghua
Published: September 2020

Transition-metal-catalyzed direct inert C–H bond functionalization has attracted much attention over the past decades. However, because of the high strain energy of the suspected palladacycle generated via C–H bond palladation, direct functionalization of a C–H bond less than a three-bond distance from a catalyst center is highly challenging. In this short review, we summarize the advances on palladium-catalyzed bridging C–H activation, in which an inert proximal C–H bond palladation is promoted by the elementary step of migratory insertion of an alkene, an alkyne or a metal carbene intermediate.

1 Introduction

2 Palladium-Catalyzed Alkene Bridging C–H Activation

2.1 Intramolecular Reactions

2.2 Intermolecular Reactions

3 Palladium-Catalyzed Alkyne Bridging C–H Activation

3.1 Intermolecular Reactions

3.2 Intramolecular Reactions

4 Palladium-Catalyzed Carbene Bridging C–H Activation

5 Conclusion and Outlook
Catalyst Development in the Dehydrogenative Borylation of Alkenes for the Synthesis Vinylboronate Esters
Authors: Wu Lipeng , Li Sida , Cui Xin , Wang Yue
Published: September 2020

Catalytic dehydrogenative borylation of alkenes provides an efficient and straightforward method for the preparation of synthetically useful vinylboronate esters. Here, we present a summary of developments and recent advances in this area, classified according to the various reactants and catalyst systems.

1 Introduction

2 Catalytic Dehydrogenative Borylation of Alkenes by Using Boranes

3 Catalytic Dehydrogenative Borylation of Alkenes by Using Diboranes

4 Zirconium-Catalyzed H
2
–Acceptorless Dehydrogenative Borylation of Alkenes with Boranes

5 Conclusion and Outlook
Nitrosocarbonyl Carbohydrate Derivatives: Hetero Diels–Alder and Ene Reaction Products for Useful Organic Synthesis
Authors: Quadrelli Paolo , Corti Marco , Leusciatti Marco , Moiola Mattia , Mella Mariella
Published: September 2020

The generation and trapping of two new nitrosocarbonyl intermediates bearing carbohydrate-based chiral substituents is achieved by the mild oxidation of the corresponding nitrile oxides with tertiary amine N-oxides. Their capture with suitable dienes and alkenes afforded the corresponding hetero Diels–Alder cycloadducts and ene adducts from fair to excellent yields. The entire methodology looks highly promising by the easy conversion of aldoximes into hydroxymoyl halides, widening the access to nitrosocarbonyls, versatile tools in organic synthesis.
Pentamethylphenyl (Ph*) and Related Derivatives as Useful Acyl Protecting Groups for Organic Synthesis: A Preliminary Study
Authors: Donohoe Timothy J. , Cheong Choon Boon , Frost James R.
Published: September 2020

A study of acyl protecting groups derived from the Ph* motif is reported. While initial studies indicated that a variety of functional groups were not compatible with the Br2-mediated cleavage conditions required to release the Ph* group, strategies involving the use of different reagents or a modification of Ph* itself (Ph*OH) were investigated to solve this problem.
Synthesis of Chiral Fluorides by Sequential Organocatalyzed Desymmetrization of Glutaric Anhydrides and Photoredox-Catalyzed Decarboxylic Fluorination
Authors: Yu Shouyun , Zhao Jia-Jia
Published: September 2020

We have developed an efficient method for the preparation of chiral fluorinated compounds by sequential organocatalyzed desymmetrization of 3-substituted glutaric anhydrides and photoredox-catalyzed decarboxylic fluorination. Chiral fluorides can be prepared in yields of up to 58% and with excellent enantioselectivities of up to 98% ee.
Fatores de insucesso do tratamento cirúrgico da síndrome do túnel do carpo: Quando e como revisar a cirurgia de descompressão do túnel do carpo
Authors: Fernandes Carlos Henrique , Santos João Baptista Gomes dos , Schwartz-Fernandes Francisco , Ostermann A. Lee , Faloppa Flávio
Published: September 2020

Apesar de ser um procedimento amplamente utilizado em todo o mundo e com elevadas taxas de remissão dos sintomas, o tratamento cirúrgico da síndrome do túnel do carpo pode apresentar resultados não satisfatórios ao paciente. Esse resultado não satisfatório pode se manifestar clinicamente pela não remissão dos sintomas, remissão dos sintomas mas recorrência desses após um período de tempo da cirurgia ou aparecimento de diferentes sintomas após a cirurgia. Diferentes fatores estão relacionados a esse insucesso do tratamento cirúrgico da síndrome do túnel do carpo (ITCSTC). A prevenção pode ser conseguida por meio de minuciosa avaliação clínica do paciente no período pré-operatório. Dessa forma o cirurgião poderá fazer diagnósticos diferenciais ou diagnósticos concomitantes, assim como identificar fatores ligados a insatisfação do paciente. Os fatores per-operatórios incluem a correta identificação das estruturas anatômicas para completa descompressão do nervo mediano. Inúmeros procedimentos têm sido descritos para o tratamento dos fatores que ocorrem no período pós-operatório. Desses o mais comum, a formação de aderências em torno do nervo mediano, tem sido tratado com relativo sucesso utilizando diferentes retalhos vascularizados ou cobertura com o uso de tecido autólogo ou homólogo. Descreveremos a abordagem do ITCSTC com maiores detalhes no texto.
Propeller Flaps in the Posterior Trunk
Authors: Kedar Daniel J , Pak Changsik John , Suh Hyunsuk Peter , Hong Joon Pio
Published: September 2020

The reconstruction of complex posterior trunk defects remains challenging. But now with an increased knowledge of angiosomes and the practice of perforator flaps, the posterior trunk offers a new plethora of options for reconstruction. Propeller flaps based on such perforator(s) offer an elegant solution for managing defects while achieving primary donor-site closure without significant morbidity. We will discuss the relevant anatomy and design principles for propeller flaps based on a review of the literature and our experience. Steps beginning with preoperative planning, perforator selection, and intraoperative surgical technique will be discussed, together with pearls on both avoiding and managing complications.
Propeller Flaps in the Head and Neck
Authors: Cordova Adriana , D'Arpa Salvatore , Rosatti Fernando , Nichelini Marta , D'Antonio Giovanni Maria , Giordano Salvatore , Toia Francesca
Published: September 2020

Propeller flaps have significantly expanded the reconstruction possibilities in the head and neck region. They allow for increased flap mobility and better scar concealing, and/or to perform a one-stage reconstruction with local tissue of similar color and texture, where multiple surgeries would be needed with traditional flaps or even free flaps would be required. This article describes the main propeller flaps for one-stage reconstruction in the head–neck region (facial artery perforator, supratrochlear artery axial perforator, deep lingual artery axial perforator, and anterior supraclavicular artery perforator flaps), their indications, and possible complications. Aesthetic and functional results of propeller flaps in the head and neck region are very good and the complication rate is low, but due to their surgical complexity and the availability of many simpler local flaps, they are indicated only in select cases where local flaps are unavailable or would require multiple staged procedures to complete the construction.
Tradução e adaptação cultural do questionário “Thumb Disability Exam – TDX” para o português brasileiro
Authors: Almeida Vinícius Alexandre de Souza , Fernandes Carlos Henrique , Meireles Lia Miyamoto , Santos João Batista Gomes dos , Faloppa Flavio , Ejnisman Benno
Published: September 2020

Objetivo Realizar a tradução, adaptação cultural e validação do questionário Thumb Disability Exam (TDX) para o português brasileiro.

Método O questionário foi traduzido, com tradução reversa. As traduções foram avaliadas e sintetizadas por um comitê, chegando ao THUMB DISABILITY EXAM - BRASIL (TDX-BR). Foram selecionados 31 pacientes com diagnóstico de rizartrose que responderam ao questionário. Foram avaliados parâmetros de qualidade, como consistência interna, reprodutibilidade e efeito teto e piso.

Resultados Os questionários foram traduzidos e adaptados conforme protocolos definidos. A consistência interna, através do coeficiente α de Cronbach para o TDX-BR foi de 0,962. A confiabilidade do questionário, através do coeficiente de correlação intraclasse (CCI) também se mostrou bastante elevada, com κ = 0,953 (0,947–0,959). A concordância, medida através do erro padrão de medição manteve-se com valores padronizados < 5%. Não houve efeito teto e piso.

Conclusão Através de metodologia específica, consideramos o TDX-BR como traduzido e válido para a língua portuguesa do Brasil.
Donación y trasplante de órganos en medio de la pandemia COVID-19: Consecuencias y retos para un país emergente
Authors: Castañeda-Millán David Andrés , Pardo-Acuña Julián , Cortés-Páez David Augusto , Autran-Gómez Ana María , Pérez-Pachón Alejandra María , Niño-Ramírez Liz , Fajardo-Cediel William
Published: September 2020

La pandemia del SARS-CoV 2 es uno de los eventos en salud pública más relevantes de los últimos años, sus efectos se han traducido en millones de casos de contagios, en más de 430.000 fallecimientos y en un aumento en la necesidad de camas de cuidados intensivos alrededor del mundo. En ese contexto, se ha presentado una reducción significativa de la actividad de donación y trasplantes en varios países, y Colombia no ha sido ajena a ese fenómeno. El presente artículo, pretende dar al lector una perspectiva del estado actual de la donación y trasplantes en el mundo y en Colombia, así como plantear algunos retos que genera la pandemia del SARS-CoV 2 para la ejecución segura del proceso de donación y trasplantes en países con recursos humanos, financieros y de infraestructura limitados.
Derivation and Validation of a Predictive Score for Disease Worsening in Patients with COVID-19
Authors: Gerotziafas Grigoris T. , Sergentanis Theodoros N. , Voiriot Guillaume , Lassel Ludovic , Papageorgiou Chryssa , Elabbadi Alexandre , Turpin Matthieu , Vandreden Patrick , Papageorgiou Loula , Psaltopoulou Theodora , Terpos Evangelos , Dimopoulos Meletios-Athanasios , Parrot Antoine , Cadranel Jacques , Pialoux Gilles , Fartoukh Muriel , Elalamy Ismail
Published: September 2020

The prospective observational cohort study COMPASS-COVID-19 aimed to develop a risk assessment model for early identification of hospitalized COVID-19 patients at risk for worsening disease. Patients with confirmed COVID-19 (n = 430) hospitalized between March 18 and April 21, 2020 were divided in derivation (n = 310) and validation (n = 120) cohorts. Two groups became evident: (1) good prognosis group (G-group) with patients hospitalized at the conventional COVID-19 ward and (2) Worsening disease group (W-group) with patients admitted to the intensive care unit (ICU) from the emergency departments. The study end point was disease worsening (acute respiratory failure, shock, myocardial dysfunction, bacterial or viral coinfections, and acute kidney injury) requiring ICU admission. All patients were routinely evaluated for full blood count, prothrombin time, fibrinogen, D-dimers, antithrombin (AT), and protein C activity. Data from the first hospitalization day at the conventional ward or the ICU were analyzed. Cardiovascular risk factors and comorbidities were routinely registered. Obesity, hypertension, diabetes and male gender, increased fibrinogen and D-dimers, thrombocytopenia, AT deficiency, lymphopenia, and an International Society on Thrombosis and Haemostasis (ISTH) score for compensated disseminated intravascular coagulation score (cDIC-ISTH) ≥5 were significant risk factors for worsening disease. The COMPASS-COVID-19 score was derived from multivariate analyses and includes obesity, gender, hemoglobin, lymphocyte, and the cDIC-ISTH score (including platelet count, prothrombin time, D-dimers, AT, and protein C levels). The score has a very good discriminating capacity to stratify patients at high and low risk for worsening disease, with an area under the receiver operating characteristic curve value of 0.77, a sensitivity of 81%, and a specificity of 60%. Application of the COMPASS-COVID-19 score at the validation cohort showed 96% sensitivity. The COMPASS-COVID-19 score is an accurate clinical decision-making tool for an easy identification of COVID-19 patients being at high risk for disease worsening.
Accidental Placement of Nasogastric Tube into the Brain: Case Report and Review of the Literature
Authors: Ansari Khursheed , Harvitkar Rafique Umer , Shetty Saiprasad , Raut Tushar P. , Qureshi Shabnam
Published: September 2020

The nasogastric tube (NGT) plays a very vital role in the early resuscitation of head injury patients for various reasons. Though considered a simple procedure, it can be associated with multiple dreadful complications. Our patient was a 44-year-old male, referred from a peripheral health center for further management of severe head and faciomaxillary injuries following a motor vehicular accident. On arrival at the hospital, the endotracheal tube and NGT were in situ. A computed tomography scan of the brain revealed the NGT piercing through the cribriform plate of ethmoid and coiling into the cranial cavity with pneumocephalus. The NGT was retrieved under C-arm guidance and his injuries were managed respectively. The patient was discharged after prolong hospitalization with an acceptable outcome. With this case report, we want to remind emergency health care providers to avoid this catastrophic complication of NGT insertion in a faciomaxillary trauma patient by doing it transorally. We report a novel method of safely removing NGT which has not been reported in the past.
Experimental locating of rotor sound source using a compact microphone array
Authors: Zhang Cui Qing , Gao Zhi Ying , Chen Yongyan , Lv Wen chun , Chen Jin xia , Liu Yuntao
Published: September 2020

As wind-power installations increase rapidly worldwide in both number and capacity, the noise problems created by wind turbines, which increasingly are being installed near residential areas, are becoming more pressing. For noise-reduction purposes, a wind turbine can be viewed as being a mechanism for generating aerodynamic noise, and key to that noise reduction is a precisely localized sound source. In this paper, the acoustic signal of an S-wing horizontal-axis wind turbine with a diameter of 1.4 m is acquired using a 60-channel microphone array. Using beamforming, the sound-source distribution and frequency characteristics are analyzed in detail, showing different frequency bands at different wind speeds and tip speed ratios. The results show that the sound pressure level of the sound source (i) decreases gradually with increasing frequency band and (ii) increases gradually with increasing wind speed and tip speed ratio. The radial location of the sound source approaches the blade tip gradually, but the variance is not large. The relevant experimental data and conclusions provide a research basis for exploring the mechanism for the aerodynamic noise and ways to reduce it.
An agent-based model of multi-dimensional opinion dynamics and opinion alignment
Authors: Schweighofer Simon , Garcia David , Schweitzer Frank
Published: September 2020

It is known that individual opinions on different policy issues often align to a dominant ideological dimension (e.g., left vs right) and become increasingly polarized. We provide an agent-based model that reproduces alignment and polarization as emergent properties of opinion dynamics in a multi-dimensional space of continuous opinions. The mechanisms for the change of agents’ opinions in this multi-dimensional space are derived from cognitive dissonance theory and structural balance theory. We test assumptions from proximity voting and from directional voting regarding their ability to reproduce the expected emerging properties. We further study how the emotional involvement of agents, i.e., their individual resistance to change opinions, impacts the dynamics. We identify two regimes for the global and the individual alignment of opinions. If the affective involvement is high and shows a large variance across agents, this fosters the emergence of a dominant ideological dimension. Agents align their opinions along this dimension in opposite directions, i.e., create a state of polarization.
AC measurement of the Nernst effect of thin films at low temperatures
Authors: Wu Y. , Dutta S. , Jesudasan J. , Frydman A. , Roy A.
Published: September 2020

We describe an alternating current method to measure the Nernst effect in superconducting thin films at low temperatures. The Nernst effect is an important tool in the understanding of superconducting fluctuations and, in particular, vortex motion near critical points. However, in most materials, the Nernst signal in a typical experimental setup rarely exceeds a few μV, in some cases being as low as a few nV. DC measurements of such small signals require extensive signal processing and protection against stray pickups and offsets, limiting the sensitivity of such measurements to >1 nV. Here, we describe a method utilizing a one-heater-two-thermometer setup with the heating element and thermometers fabricated on-chip with the sample, which helped to reduce the thermal load and temperature lag between the substrate and the thermometer. Using AC heating power and 2ω measurement, we are able to achieve sub-nanovolt sensitivity in 20 nm–30 nm thin superconducting films on a glass substrate, compared to a sensitivity of ∼10 nV using DC techniques on the same setup.
An experimental system for time-resolved x-ray diffraction of deforming silicate melt at high temperature
Authors: Okumura Satoshi , Uesugi Kentaro , Sakamaki Tatsuya , Goto Akio , Uesugi Masayuki , Takeuchi Akihisa
Published: September 2020

Rheological behavior of silicate melts controls the dynamics of volcanic eruptions. Previous experimental studies have investigated melt viscosity and found non-Newtonian behavior of the melt under a high shear rate. However, the relationship between macroscopic rheology and atomic-scale behavior under shear remains unclear. We developed an experimental system for time-resolved x-ray diffraction (XRD) at high temperature to investigate the atomic-scale structural change in melts under shear. The manufactured deformation apparatus and heating furnace were set on the synchrotron radiation x-ray beamline (BL20XU) of SPring-8; the XRD pattern of the melt at high temperature could be observed using this system because the furnace mainly consists of a boron nitride cylinder with high x-ray transmittance. Here, we report results of fiber elongation experiments for a soda-lime melt. Melt fibers with ∼0.7 mm in diameter and ∼27 mm long were elongated at 100 µm sec−1 at temperatures of 595 °C and 620 °C, and the XRD pattern was obtained every 100 msec. Brittle failure of the melt occurred at 595 °C, whereas the melt viscously elongated at 620 °C. The XRD patterns obtained during elongation did not indicate any clear change immediately before brittle failure. The intensity of the XRD pattern decreased with the elongation at 620 °C, although there was no clear variation in its shape. These results indicate that the atomic-scale structure observed by XRD may not change during the elastic and viscous elongation of the soda-lime melt. This experimental system will be further developed and applied to more polymerized and natural silicate melts.
Formation of excited triplet states in naphthalene diimide and perylene diimide derivatives: A detailed theoretical study
Authors: Isukapalli Sai Vamsi Krishna , Lekshmi R. S. , Samanta Pralok Kumar , Vennapusa Sivaranjana Reddy
Published: September 2020

Mechanistic details of the excited triplet state formation upon photoexcitation to the low-lying singlet manifold in naphthalene diimide and perylene diimide derivatives are explored theoretically. Static and dynamic aspects of two singlets (S1 and S2) and six triplets (T1–T6) of these molecules are investigated. Suitable vibronic Hamiltonians are constructed to investigate the internal conversion dynamics in both the singlet and triplet manifolds. Computed singlet–triplet energetics, spin–orbit coupling matrix elements, and intersystem crossing rates strongly suggest an efficient intersystem crossing process involving higher triplet states (T6, T5, and T4). Separate full dimensional quantum wavepacket simulations of singlet and triplet manifolds in the approximate linear vibronic model by assuming initial Franck–Condon conditions are carried out to unravel the internal conversion decay dynamics in the respective manifolds. The obtained diabatic electronic populations and nuclear densities are analyzed to illustrate the triplet generation pathways involving higher triplet states in these molecules.
Molecular beam epitaxy of GaN on 2H–MoS2
Authors: Lee Choong Hee , Zhang Yuewei , Johnson Jared M. , Koltun Rachel , Gambin Vincent , Jamison John S. , Myers Roberto C. , Hwang Jinwoo , Rajan Siddharth
Published: September 2020

Recent interest in the heterogeneous integration of two-dimensional (2D) materials with three-dimensional (3D) semiconductors has resulted in the implementation of direct heteroepitaxial growth via various epitaxy techniques. In this study, we demonstrated the synthesis of wafer-scale direct growth of GaN on MoS2 using plasma-assisted molecular beam epitaxy. Systematic studies were employed to understand the growth diagram of GaN on large area multi-layer MoS2, and various growth parameters such as substrate temperature and Ga to N flux ratio were investigated to study the degradation mechanism of the underlying MoS2 layer. The growth diagram of GaN on MoS2 was proposed based on the studies. The microstructure of GaN (i.e., N-rich and 550 °C) was evaluated by scanning transmission electron microscopy. Phase segregation was found in the N-rich GaN layer. A two-step growth process involving N-rich condition at a lower temperature and Ga-rich condition at a higher growth temperature was attempted to obtain the smooth and high crystalline quality of GaN. While the two-step growth method led to substantial improvement in the film quality, the removal of MoS2 was observed and the degradation of MoS2 substrate was attributed to Ga diffusion through dislocation lines based on energy-dispersive x-ray spectroscopy mapping. This work helps illuminate critical issues in the epitaxial growth of conventional semiconductors on 2D crystals for various device applications.