bluuebunny/crossref_metadata_2025_split huggingface dataset:
40‐MHz high‐frequency vector Doppler imaging for superficial venous valve flow estimation
Authors: Huang Hsin , Chen Pei‐Yu , Huang Chih‐Chung 
Published: July 2020

PurposeDoppler ultrasound imaging has been used widely for diagnosing vascular diseases. Recently, vector Doppler imaging (VDI) has been proposed for visualizing the blood flow in all directions to yield more detailed information for estimating flow conditions. Increasing the resolution of VDI is important for the structural mapping of superficial vessels with microstructure. However, VDI that operates under a high‐frequency ultrasound (HFUS; >30 MHz) is rare. In this study, a 40‐MHz high‐frequency VDI (HFVDI) based on ultrafast ultrasound imaging was developed to obtain the vector information of blood flow around the superficial venous valve.MethodsThe use of HFUS imaging system causes an overload of data acquisition easily. In order to provide sufficient recording time, the frame rate should be reduced. Because the aliasing problem worsens due to a low frame rate when operating Doppler imaging, phase‐unwrapping processing methods based on spatial and temporal continuities were applied. Flow phantom experiments were performed to validate the accuracy. In vivo experiments were performed on the valve of superficial veins of healthy volunteers.ResultsThe experimental results from the phantom study indicated that the error of velocity estimation was <10% in most cases. Dynamic changes of valve movements and flow conditions (including velocity profiles and vector) were observed. Because of the high resolution of HFVDI, the jet and vortex phenomena were observed between the leaflets and in the sinus pocket, respectively.ConclusionsFlow velocities ranging from 2 to 15 mm/s were measured at different locations around the venous valve during the opening and closing phases. All the results indicated that HFVDI has the potential to be a useful tool for vessel duplex scanning.
Solarzellen mit Bismut statt Blei
Authors: Gangl Maurice , Ünlü Feray , Fischer Thomas , Mathur Sanjay , Banerji Amitabh 
Published: July 2020

AbstractOrganisch‐anorganische Hybrid‐Perowskite gelten als Wundermaterial für die Photovoltaik und werden weltweit erforscht. Allerdings können die Materialien Blei freisetzen und eignen sich daher nicht für Experimente in der Schule. Eine Alternative ist eine perowskitähnliche Solarzelle auf Rudorffit‐Basis, die verhältnismäßig preiswert und einfach selbst zu bauen ist.
Vorhersagen aus Hochdurchsatzstudien
Authors: George Janine , Suta Markus 
Published: July 2020

AbstractSollen Materialien mit bestimmten Eigenschaften entwickelt werden, etwa Katalysatoren oder Solarzellen, ist es schwierig, die optimale Kombination dieser Eigenschaften zu finden. Automatisierte quantenchemische Rechnungen helfen dabei, Kandidaten zu identifizieren. Damit ergänzen sie die experimentelle Arbeit und erschließen sogar ganze Materialklassen.
Forschen will gelernt sein
Authors: Brandt Felix , Wolter Mario , Jacob Christoph R. 
Published: July 2020

AbstractNach wie vor beginnen die meisten Chemiestudierenden nach ihrem Abschluss mit einer Doktorarbeit. Um erfolgreich selbstständig wissenschaftlich arbeiten zu können, müssen sie im Studium aber nicht nur Fachwissen und praktische Fertigkeiten erwerben – sondern auch lernen, was Forschen bedeutet.
Trendbericht Biochemie: Strukturbiologie von Sars‐Cov‐2 mit NMR‐Spektroskopie
Authors: Schwalbe Harald 
Published: July 2020

AbstractInzwischen können wir die zellulären Prozesse in lebenden Zellen verfolgen, und zwar mit subzellulärer Fluoreszenzmikroskopie mit Auflösung im Nanometerbereich. Ob Ribosomen die richtigen Proteine herstellen oder eine Leseschwäche haben, lässt sich durch Ribosomenprofiling untersuchen. Und: Bisher haben intrinsische Dynamik und Heterogenität erschwert, die dreidimensionale Struktur von Multiproteinkomplexen zu bestimmen. Kryoelektronenmikroskopie erlaubt es nun, diese schwer greifbaren Maschinerien mit höchster Auflösung abzubilden.
Trendbericht Biochemie: Klare Sicht auf zelluläre Nanomaschinen
Authors: Trowitzsch Simon , Möller Arne 
Published: July 2020

AbstractInzwischen können wir die zellulären Prozesse in lebenden Zellen verfolgen, und zwar mit subzellulärer Fluoreszenzmikroskopie mit Auflösung im Nanometerbereich. Ob Ribosomen die richtigen Proteine herstellen oder eine Leseschwäche haben, lässt sich durch Ribosomenprofiling untersuchen. Und: Bisher haben intrinsische Dynamik und Heterogenität erschwert, die dreidimensionale Struktur von Multiproteinkomplexen zu bestimmen. Kryoelektronenmikroskopie erlaubt es nun, diese schwer greifbaren Maschinerien mit höchster Auflösung abzubilden.
Trendbericht Biochemie: Ribosomenprofiling
Authors: Leidel Sebastian Andreas 
Published: July 2020

AbstractInzwischen können wir die zellulären Prozesse in lebenden Zellen verfolgen, und zwar mit subzellulärer Fluoreszenzmikroskopie mit Auflösung im Nanometerbereich. Ob Ribosomen die richtigen Proteine herstellen oder eine Leseschwäche haben, lässt sich durch Ribosomenprofiling untersuchen. Und: Bisher haben intrinsische Dynamik und Heterogenität erschwert, die dreidimensionale Struktur von Multiproteinkomplexen zu bestimmen. Kryoelektronenmikroskopie erlaubt es nun, diese schwer greifbaren Maschinerien mit höchster Auflösung abzubilden.
„Plötzlich waren keine Studenten mehr da“
Authors: Zbikowski Frauke 
Published: July 2020

AbstractWie forschen Chemiker, wenn sie nicht ins Labor dürfen? Analytiker und Anorganiker, Doktoranden und Professoren, Nachwuchsgruppenleiter und Grenzgänger über ihren Umgang mit Infektionsschutz, Zoom‐Meetings sowie den Spagat zwischen Heimarbeit und Kinderbetreuung.
Accuracy of Concert versus Independent Age Estimates Made from Anal Fin Rays of Muskellunge
Authors: Molina Joseph T. , Crane Derek P. , Bell Lindsey 
Published: June 2020

Abstract
Fisheries managers use age data to estimate important components of fish population dynamics. Age estimates for fishes are often made by multiple readers, and when readers disagree, they may view the structure together to determine a concert age estimate. Few studies have evaluated the accuracy of concert readings compared to independent readings. We used anal fin rays from 240 known-age Muskellunge Esox masquinongy to compare the accuracy and bias of age estimates from 10 independent readers and five reader pairs. We compared average difference from known age (bias) and absolute difference from known age (accuracy) between concert and independent estimates and used a bootstrap analysis to estimate the percentage of randomly sampled independent estimates that were as accurate or more accurate than concert estimates. Analyses were completed using the full data set (all estimates regardless of reader disagreement) and a subset (N = 127) including only samples for which there was disagreement between readers. Finally, we fit sex-specific von Bertalanffy growth models based on 5,000 bootstrap data sets for independent estimates and known age to investigate the effects of age estimation procedures on growth models. Overall, and when there was disagreement between readers, independent estimates were as accurate and less biased for fish older than age 12 compared to concert estimates. Independent estimates were as accurate or more accurate than concert estimates for 79% of bootstrap samples based on the full data set and 65% of bootstrap samples from the subset of data. Additionally, mean parameter estimates for von Bertalanffy growth models did not differ between models using randomly selected independent estimates and models using known ages. When completing studies that require age estimation, we recommend first verifying the utility of concert age estimates because if concert estimates do not improve accuracy, time may be saved by selecting one reader’s individual age estimate.
Measuring the Stability of Supramolecular Complexes in the Proximity of Single‐Walled Carbon Nanotubes
Authors: Naranjo Teresa , Villalva Julia , Pérez Emilio M. 
Published: July 2020

AbstractInvited for this month's cover is Emilio M. Pérez from IMDEA Nanociencia in Madrid. The cover picture shows the supramolecular association of an ammonium guest to a crown‐ether host which is covalently attached to a SWNT. In our manuscript, we show that the corresponding “KPOW!!” would be significantly louder for the binding of the free species in solution, in the absence of the SWNT. Read the full text of their Communication at 10.1002/open.202000018.
Optiflow vs Vapotherm as extended weaning mode from nasal continuous positive airway pressure in preterm infants ≤ 28 weeks gestational age
Authors: Fernandez‐Alvarez J. Ramon , Mahoney Liam , Gandhi Rashmi , Rabe Heike 
Published: July 2020

AbstractIntroductionCurrent evidence supports nasal continuous positive airway pressure (NCPAP) weaning. Heated humidified high‐flow nasal cannula (HHFNC) reduces NCPAP time in infants less than 28 weeks gestational age (GA) without increasing morbidity. The aim of the study was to compare the two most frequently used HHFNC devices in weaning from NCPAP.MethodologyWe performed a retrospective matched‐pair case‐control study of infants less than or equal to 28 GA born in a single tertiary neonatal center managed with Optiflow or Vapotherm after being weaned from NCPAP. Patients were matched for antenatal steroid doses, delivery mode, birth plurality, GA, birthweight, gender, surfactant doses, length of mechanical ventilation, and length of NCPAP. Outcome measures were duration of HHFNC, low‐flow nasal cannula, nasal bridge lesions, pneumothorax, bronchopulmonary dysplasia, postnatal steroids, necrotizing enterocolitis, sepsis, intraventricular hemorrhage, retinopathy of prematurity, length of stay, discharge weight, and mortality. Results were displayed as median (interquartile range) or ratio (percentage). Statistical analysis was performed using Mann‐Whitney U and χ2 tests.Results70 patients were recruited retrospectively. Thirty‐five infants were weaned from NCPAP to Optiflow and 35 infants to Vapotherm with gestational ages and birthweights of 27 GA (26‐27) and 1010 g (835‐1165) and 27 GA (26‐28) and 960 g (788‐1191), respectively. There was no statistically significant difference in any outcome measure. Infants managed with Vapotherm required a not statistically significant shorter length of time on HHFNC and low‐flow nasal cannula.ConclusionsOptiflow and Vapotherm seem to be equally effective and safe for weaning from NCPAP. However, infants weaned to Vapotherm appear to spend less time on non‐invasive respiratory support.
A case report on hydroxychloroquine induced maculopapular rashes: The immunosuppressant and corticosteroid therapy
Authors: Sunil Kumar Salkapuram , Elumalai Karthikeyan , Eluri Kalpana , Elumalai Manogaran , Mallu Keerthana , Srinivasan Sivaneswari , Ranjan Chanda , Sivannan Srinivasan 
Published: July 2020

AbstractMaculopapular rashes could even be an assortment of hasty characterized by grade, ruddy region on the skin that is secured with little intersecting bumps. During this case, a 55‐year‐old woman patient has developed maculopapular rashes over the body. It is a medical reaction caused because of the hydroxychloroquine, which the patient has taken for her joint pains. Simultaneous development of blisters over the forehead, scalp, upper and lower limbs, which eventually get ruptured and formed various erosions. This episode was once severe because of the repeated intake of hydroxychloroquine as a daily regimen. This hydroxychloroquine resulted in pustules that were investigated and excision biopsy of the ruptured erosion was once administered and verified as maculopapular rashes. The patient was treated with immunosuppression, systemic, and topical corticosteroids for a month for the management and treatment of the rashes.
Modulating tumor reactive stroma by extracorporeal shock waves to control prostate cancer progression
Authors: Rinella Letizia , Pizzo Benedetta , Frairia Roberto , Delsedime Luisa , Calleris Giorgio , Gontero Paolo , Zunino Valentina , Fortunati Nicoletta , Arvat Emanuela , Catalano Maria Graziella 
Published: July 2020

AbstractBackgroundProstate cancer is the second most common cancer worldwide. Tumor microenvironment is composed of activated fibroblasts, the so called carcinoma‐associated fibroblasts (CAFs). They express high levels of α‐smooth muscle actin (α‐SMA) and type I collagen (COL1), and support proliferation and migration of tumor epithelial cells. Extracorporeal shock waves (ESWs), acoustic waves, are effective in the treatment of hypertrophic scars, due to their ability to modulate fibrosis. Based on this rationale, the study evaluated the effects of ESWs on CAF activation and the influence of ESW‐treated CAFs on the growth and migration of epithelial prostatic carcinoma cells.MethodsPrimary cultures of CAFs (n = 10) were prepared from tumors of patients undergoing surgery for high‐risk prostate carcinoma. CAFs were treated with ESWs (energy levels: 0.32 mJ/mm2, 1000 pulses; 0.59 mJ/mm2, 250 pulses). After treatment, the messenger RNA and protein levels of the stromal activation markers α‐SMA and COL1 were determined. Subsequently, two different stabilized cell lines (PC3 and DU145) of androgen‐resistant prostate cancer were treated with the conditioned media produced by ESW‐treated CAFs. At different times, viability and migration of PC3 and DU145 cells were evaluated. Viability was also assessed by coculture system using CAFs and PC3 or DU145 cells.ResultsESWs reduced gene expression and protein level of α‐SMA and COL1 in CAFs. The treatment of PC3 and DU145 with conditioned media of ESW‐treated CAFs determined a reduction of their growth and invasive potential. Coculture systems between ESW‐treated CAFs and PC3 or DU145 cells confirmed the epithelial cell number reduction.ConclusionsThis in vitro study demonstrates for the first time that ESWs are able to modulate the activation of prostate CAFs in favor of a less “reactive” stroma, with consequent slowing of the growth and migration of prostate cancer epithelial cells. However, only further studies to be performed in vivo will confirm the possibility of using this new therapy in patients with prostate cancer.
Quaternary Vanado‐Molybdotungstophosphoric Acid [H5PW6Mo4V2O40] Over Natural Montmorillonite as a Heterogeneous Catalyst for the Synthesis 4H‐Pyran and Polyhydroquinoline Derivatives
Authors: Aher Dipak S. , Khillare Kiran R. , Chavan Laxmikant D. , Shankarwar Sunil G. 
Published: July 2020

AbstractSynthesis of an efficient and novel vanadium substituted molybdotungstophosphoric acid, H5PW6Mo4V2O40.14H2O (VMWP) supported on naturally occurring montmorillonite (nMont) clay by an incipient wetness impregnation technique. The support and resulting catalyst were characterized by Inductively coupled plasma atomic emission spectroscopy (ICP‐AES), Fourier transform infrared (FT‐IR), powder X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray analysis (EDX), Transmission electron microscopy (TEM) and thermogravimetric‐Differential thermal analysis (TG‐DTA). The study demonstrated that newly synthesized VMWP well incorporated on nMont with their good performance and activity. The catalytic application is evaluated in one‐pot multicomponent synthesis of tetrahydrobenzo[b]pyrans (4H‐Pyran) and polyhydroquinolines in excellent yield. High conversion, shorter reaction time, environmentally benign solvent simple experimental and work procedure and reusability of the catalyst are the prominent features of our synthetic route.
Asymmetric Aldol Reaction of Pyruvate Promoted by Chiral Tertiary Amines
Authors: Pasternak‐Suder Monika , Pacułt Wojciech , Baś Sebastian , Mlynarski Jacek 
Published: July 2020

AbstractThe direct asymmetric aldol reaction of α‐ketoesters catalyzed by chiral tertiary amines is reported. The described methodology is characterized by mild reaction conditions and distinct product selectivity determined by the starting materials. In the developed transformation pyruvates undergo highly selective self‐condensation reaction, whereas cross‐aldol reaction take place predominantly for their carbon chain homologues in presence of aldehyde acceptors. Notably, addition of bulky phenol moiety into pyruvate inhibit the spontaneous lactonization of products and enhance the enantioselectivity.
Assembling Nickel Oxide Nanoparticles into Porous Polyhedra: Highly Active Electrocatalysts for Alkaline Water Oxidation
Authors: Zhou Jian , Dong Yonghong , Ma Yongzhi , Zhang Tiezhu 
Published: July 2020

AbstractNickel oxide (NiO) with high surface area was widely investigated in electrochemical applications. However, its use was largely confined to morphologies of particles and thin films. Here, we assembled NiO nanoparticles into mesoporous polyhedra with better active‐site exposure for oxygen evolution reaction (OER) catalysis. It needs an overpotential of 280 mV to drive 10 mA cm−2 in 1.0 M KOH, outperforming many reported transition‐metal oxides. Its activity can be mantained for at least 20 hours. High surface area of mesoporous polyhedra affirmed by Brunner‐Emmet‐Teller measurement contributes to the outstanding catalytic activity. Using one of the most abundant metal elements to constuct high‐performance OER catalysts will provide great convenience for industrial applications.
Quaternary‐Ammonium‐Based Gels with Varied Alkyl Chains for the Efficient Removal of Toxic Acid Orange 7
Authors: Bhattacharya Sayantani , Shunmugam Raja 
Published: July 2020

AbstractWe report the design and synthesis of thiol‐norbornene based ingenious gels with pendent quaternary ammonium substituents on the norbornene backbone that are conducive to remove toxic anionic azo dye acid orange 7 (AO7) from wastewater. Three different alkyl side chains on the dangling quaternary ammonium moiety were chosen prudently and their performance towards removal of azo dye was scrutinised. The characterisation of all the precursor monomers and the ensuing gels were accomplished by1H,13C NMR and Mass spectrometry. The influence of extent of crosslinking on the solvent uptake ability was investigated and the swelling nature of the gels were correlated with the solubility parameter of different solvents. The surface morphology of the gels as visualised by FE‐SEM analysis, revealed macropores in the range 4–12 μm. The relationship between the composition of quaternary ammonium moiety on the gels and their viscoelastic properties was realised. The dye removal kinetics as observed from UV‐Vis spectra were best correlated with the pseudo‐second‐order model and the adsorption isotherm of dye removal process was best fitted with the Langmuir isotherm model with high correlation coefficient. The material was found to be fairly recyclable up to 10thcycles with loss of only 8% efficiency. To the best of our knowledge, this is the first ever report on the removal of anionic dye based on thiol‐norbornene photo crosslinked network. We believe that this design and composition‐property relationship will enthuse the researchers to develop efficient chemical adsorbents based on environmentally benign systems.
β‐Ketodithioesters as Versatile Building Blocks for the Diversity Oriented Synthesis of Thioamides, α‐Allylated‐Thioesters and Ketoamides
Authors: Chanu Irom Harimala , Devi Laishram Momota , Singh Thokchom Prasanta , Singh Sarangthem Joychandra , Singh Rajkumar Romeshkumar , Mukherjee Singh Okram 
Published: July 2020

AbstractWhen β‐ketodithioesters (β‐KDEs) are treated with various electrophiles in multi‐component reactions, three types of highly substituted and densely functionalized reactive intermediates are generated in good yields. Dual role of piperidine as base and nucleophile in Knoevenagel condensation reactions of aromatic aldehydes and β‐ketodithioesters has been observed in our investigations. Trisubstituted (Z)‐prop‐2‐en‐1‐ones have been obtained stereoselectively as a result of these condensation reactions. β‐KDEs were further utilized in allylation reactions with allyl bromide and alkylamines leading to allylated β‐ketodithioestersand allylated β‐ketoamides in good yields.
Ammonium Nitrate‐Assisted Low‐Temperature Synthesis of Co, Co2P@CoP Embedded in Biomass‐Derived Carbons as Efficient Electrocatalysts for Hydrogen and Oxygen Evolution Reaction
Authors: Lin Changqing , Kang Mingzhen , Zheng Leizhi , Fu Xiaoqi , Wang Shuang 
Published: July 2020

AbstractElectrochemical water splitting into H2 and O2 provides a promising and sustainable strategy for the future production of clean energy. Herein, we report an ammonium nitrate (AN)‐assisted synthetic strategy to prepare Co, Co2P@CoP nanoparticles embedded in biomass‐derived porous carbons as bifunctional electrodes for water splitting. The use of AN is not only activating biomass to porous carbons, but also reducing the synthetic temperature significantly. The synergistic effects of the Co2P@CoP heterostructure could lead to a low adsorption energy of hydrogen (ΔGH*) and conduction band bending, together with the N/S‐codoped porous carbons could provide large specific surface area and desirable electron‐donating feature, contribute to the remarkable performance with overpotentials of 0.129 and 0.212 V for hydrogen evolution reaction (HER) in 0.5 mol L−1 H2SO4 and 1 mol L−1 KOH, and 0.328 V for oxygen evolution reaction (OER) in 1 mol L−1 KOH, at a current density of 10 mA cm−2. Moreover, the Co2P@CoP/PC catalysts enable overall water splitting with a small cell voltage of 1.63 V to achieve 10 mA cm−2 and exhibit long‐term durability over 1000 min.
Polymethylaminosiloxane Grafted Transition Metal Catalyst DICAT‐V for Chemoselective Aerobic Oxidation of 5‐HMF into 2,5‐Diformyl Furan
Authors: Pawar Hitesh S. 
Published: July 2020

AbstractIn the present study polymethylaminosiloxane (PMAS) grafted transition metal catalysts DICAT−M were explored for the chemoselective oxidation 5‐HMF (5‐hydroxymethyl furfural) into DFF (2,5‐diformyl furan). A series of DICAT−M; DICAT−Fe, DICAT−Co, DICAT−Mn, and DICAT−V were synthesized by grafting Fe, Co, Mn, and V, respectively and tested for the oxidation of 5‐HMF. All the synthesized catalysts selectively oxidize 5‐HMF in presence of air without the addition of any base, activator or co‐catalyst. Of the tested catalysts, the vanadium grafted catalyst (DICAT−V) showed an excellent performance with >88 % yield of DFF and >92 % conversion of 5‐HMF in low boiling organic solvent ACN at 110 °C and 20Kg/cm3. The use of ACN facilitated both solvent recovery and product separation process. The structural and surface morphological properties of DICAT−V were studied by using ATR‐FITR, SEM/EDX, XRF, XRD, and BET surface area analysis. Exploration of PMAS provides an excellent backbone architecture with bidentate amine anchors to hold transition metal and resulted in stable, robust, and recyclable catalysts. The plausible reaction mechanism was proposed for DICAT−V assisted chemoselecive aerobic oxidation. Moreover, DICAT−V showed the consistent performance to obtain >88 % yield and >90 % conversion for five consecutive recycle runs. Thus the employment of DICAT−V for 5‐HMF oxidation contributes to the development of the green and sustainable process by integrating recyclable catalyst, additive‐free protocol, LBP solvent, air as the oxidant, and high process throughputs.