bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extracellular Vesicles from 3D Engineered Microtissues Harbor Disease‐Related Cargo Absent in EVs from 2D Cultures
Authors: Millan Christopher , Prause Lukas , Vallmajo‐Martin Queralt , Hensky Natalie , Eberli Daniel 
Published: April 2021

AbstractEngineered microtissues that recapitulate key properties of the tumor microenvironment can induce clinically relevant cancer phenotypes in vitro. However, their effect on molecular cargo of secreted extracellular vesicles (EVs) has not yet been investigated. Here, the impact of hydrogel‐based 3D engineered microtissues on EVs secreted by benign and malignant prostate cells is assessed. Compared to 2D cultures, yield of EVs per cell is significantly increased for cancer cells cultured in 3D. Whole transcriptome sequencing and proteomics of 2D‐EV and 3D‐EV samples reveal stark contrasts in molecular cargo. For one cell type in particular, LNCaP, enrichment is observed exclusively in 3D‐EVs of GDF15, FASN, and TOP1, known drivers of prostate cancer progression. Using imaging flow cytometry in a novel approach to validate a putative EV biomarker, colocalization in single EVs of GDF15 with CD9, a universal EV marker, is demonstrated. Finally, in functional assays it is observed that only 3D‐EVs, unlike 2D‐EVs, confer increased invasiveness and chemoresistance to cells in 2D. Collectively, this study highlights the value of engineered 3D microtissue cultures for the study of bona fide EV cargoes and their potential to identify biomarkers that are not detectable in EVs secreted by cells cultured in standard 2D conditions.
Asymmetric Synthesis of Spirocyclopentane Oxindoles via [2+3] Annulation with 2‐(2‐Oxoindolin‐3‐yl)malononitriles as 1,2‐Carbon Bisnucleophiles
Authors: Ai Yue‐Yan , Li Dong‐Ai , Li Guo , Li He‐Ping , He Xiang‐Hong , Fu Xue‐Ju , Wang Yu‐Ting , Zhan Gu , Han Bo 
Published: April 2021

AbstractCarbon bisnucleophiles are important building blocks in organic synthesis and have widespread applications in the construction of carbocyclic compounds. Among them, 1,2‐carbon bisnucleophile has been much less explored. Herein, we developed a [2+3] annulation of 2‐(2‐oxoindolin‐3‐yl)malononitrile with 2‐nitroallylic acetates, where 2‐(2‐oxoindolin‐3‐yl)malononitrile served as a new type of 1,2‐carbon bisnucleophile. Remarkably, the annulation reaction exhibits exclusive chemo‐ and regioselectivity. A Michael addition/SN2 mechanism was proposed to avoid the “anti‐Baldwin” cyclization. This stereoselective strategy provides a facile synthetic route for a new series of spirocyclopentane oxindole derivatives containing three stereogenic centers.magnified image
Dynamic Windows Using Reversible Zinc Electrodeposition in Neutral Electrolytes with High Opacity and Excellent Resting Stability
Authors: Islam Shakirul M. , Barile Christopher J. 
Published: April 2021

AbstractDynamic windows, which electronically switch between clear and dark states, can play a vital role in energy‐efficient buildings by reducing lighting, heating, and cooling demands. In this manuscript, reversible Zn electrodeposition on tin‐doped indium oxide electrodes is studied and a mechanism is proposed that explains the deposition and dissolution processes. This mechanistic understanding enables the construction of 100 cm2 two‐electrode devices that transition from clear (80% transmission at 600 nm) to highly opaque (<0.1% transmission at 600 nm) in less than 20 s. Additionally, the dynamic windows utilize a pH‐neutral electrolyte, which enables them to switch without degradation over the course of four weeks. The high opacity and stability of the Zn‐based devices represent significant improvements over existing switchable thin films based on the reversible electrodeposition of more noble metals such as Bi and Cu.
The Role of Rotational Motion in Diffusion NMR Experiments on Supramolecular Assemblies: Application to Sup35NM Fibrils
Authors: Kharkov Boris B. , Podkorytov Ivan S. , Bondarev Stanislav A. , Belousov Mikhail V. , Salikov Vladislav A. , Zhouravleva Galina A. , Skrynnikov Nikolai R. 
Published: April 2021

AbstractPulsed‐field gradient (PFG) NMR is an important tool for characterization of biomolecules and supramolecular assemblies. However, for micrometer‐sized objects, such as amyloid fibrils, these experiments become difficult to interpret because in addition to translational diffusion they are also sensitive to rotational diffusion. We have constructed a mathematical theory describing the outcome of PFG NMR experiments on rod‐like fibrils. To test its validity, we have studied the fibrils formed by Sup35NM segment of the prion protein Sup35. The interpretation of the PFG NMR data in this system is fully consistent with the evidence from electron microscopy. Contrary to some previously expressed views, the signals originating from disordered regions in the fibrils can be readily differentiated from the similar signals representing small soluble species (e.g. proteolytic fragments). This paves the way for diffusion‐sorted NMR experiments on complex amyloidogenic samples.
Gemeinsame katalytische Umsetzung von CH4 und CO2 durch Rhodium‐Titanoxid‐Anionen RhTiO2−
Authors: Yang Yuan , Li Ya‐Ke , Zhao Yan‐Xia , Wei Gong‐Ping , Ren Yi , Asmis Knut R. , He Sheng‐Gui 
Published: April 2021

AbstractDie gemeinsame katalytische Umsetzung von Methan mit Kohlendioxid zur Erzeugung von Synthesegas (2 H2+2 CO) umfasst komplizierte Elementarschritte, und fast alle Elementarreaktionen werden praktisch bei den gleichen Hochtemperaturbedingungen der Thermokatalyse durchgeführt. Hier zeigen wir durch massenspektrometrische Experimente, dass RhTiO2− die gemeinsame Umsetzung von CH4 und CO2 zu freiem 2 H2+CO und einem adsorbierten CO (COads) bei Raumtemperatur fördert; der einzige Elementarschritt, der die Zufuhr von externer Energie erfordert, ist die Desorption von COads vom RhTiO2CO− zur Rückbildung von RhTiO2−. Die aktuelle Studie identifiziert nicht nur eine vielversprechende aktive Spezies für die Methan‐Trockenreformierung (CO2‐Reformierung) zu Synthesegas, sondern unterstreicht auch die Bedeutung der Temperaturkontrolle über Elementarschritte in der angewandten Katalyse, die die Kohlenstoffabscheidung durch Methanpyrolyse erheblich mindern könnte.
Immobilization‐free electrochemical DNA sensor based on signal cascade amplification strategy
Authors: Wei Guobing , Zhang Wenxing , Cui Hanfeng , Liao Fusheng , Cheng Lin , Ma Guangqiang , Fan Hao , Hong Nian , Zhang Jing 
Published: April 2021

AbstractThe development of convenient and efficient strategies without using complex nanomaterials or enzymes for signal amplification is very important for bioanalytical applications. Herein, a novel electrochemical DNA sensor was developed by harnessing the signal amplification efficiency of catalytic hairpin assembly (CHA) and a brand‐new signal marker tetraferrocene. The prepared sensor had both ends of the probe H2 labeled with tetraferrocene; both ends have a large number of unhybridized T bases, which cause tetraferrocene to move closer to the electrode surface, generating a high‐efficiency amplification signal. In the presence of target DNA, it induced strand exchange reactions promoting the formation of double‐stranded DNA and recycling of target DNA. Under optimal conditions, the sensor showed a good linear correlation between the peak currents and logarithm of target DNA concentrations (ranging from 0.1 fM to 0.3125 pM) with a detection limit of 0.06 fM, which is obtained by a triple signal‐to‐noise ratio. Additionally, the prepared sensor possesses excellent selectivity, reproducibility, and stability, demonstrating efficient and stable DNA detection methodology.
Wie viel Platz geben wir den Autos?
Authors: Hofer Andreas 
Published: April 2021

AbstractVerkehr produziert Stau, Abgase und Lärm. Diese Probleme werden täglich – und oft ideologisch gefärbt – debattiert. Doch nicht nur die Mobilität als solche belastet die Qualität des öffentlichen Raums, sondern auch der ruhende Verkehr. Parkierte Autos brauchen viel Platz, was in dichten Gebieten hohe Kosten verursacht. Die Infrastrukturen für den ruhenden Verkehr (Parkhäuser etc.) sind teuer und behindern den Bau von dringend benötigten zahlbaren Wohnungen. Trotzdem scheuen sich die Gesetzgeber und die sie beratenden Kommissionen davor, von den bestehenden Stellplatzschlüsseln abzuweichen. Zu groß ist die Angst, dass die Reduktion von Parkierungsmöglichkeiten die Kommunen zusätzlich belasten und zu Konflikten in den Quartieren und den umliegenden Nachbarschaften führen könnte. Diese Widersprüche akzentuieren sich zurzeit. Der individuelle Verkehr befindet sich in einem Transformationsprozess. Unbekannt ist, wie schnell dieser ablaufen wird und in welcher konkreten Form. Es besteht also eine große Planungsunsicherheit. Gleichzeitig ist eines klar: Die Anforderungen an die innere Verdichtung der Städte, an die Verbesserung der öffentlichen Räume, den Klima‐ und Ressourcenschutz sind nur durch eine massive Senkung des Individualverkehrs und des Verbrauchs von verbauter grauer Energie erreichbar. Zudem muss das urbane Wassermanagement aufgrund des Klimawandels umgebaut werden. Starkregenereignisse müssen lokal gepuffert werden, Niederschlagswasser muss für Bewässerung und kühlende Verdunstung genutzt werden. Solchen Herausforderungen kann man mit neuen Betriebs‐ und Bewirtschaftungsmodellen begegnen – oder damit, die Typologien städtischer Infrastrukturen neu zu denken. Auf den folgenden Seiten werden einige pionierhafte Projekte vorgestellt sowie ihre Wirkung und Perspektiven diskutiert. Beispiele aus der Stadt Zürich stehen dabei im Vordergrund, hier wird seit über 20 Jahren politisch über das Auto in der Stadt gestritten. Teilweise bemerkenswert unverkrampfte Lösungen zeigen, dass ein anderer Umgang mit dem individuellen Autobesitz in einer der reichsten Städte der Welt möglich ist. Und auch in anderen.
Research Progress and Prospects for Fructosyltransferases
Authors: Wang Yitian , Shang Xiujie , Cao Fan , Yang Haiquan 
Published: April 2021

AbstractFructosyltransferases can be used to produce fructooligosaccharides from sucrose and are obtained from different sources, mostly microorganisms and plants. Heterologous expression and several mutagenesis methods were applied to improve the production of fructosyltransferases. The structures and characteristics of fructosyltransferases were investigated. Immobilization and protein engineering can improve their characteristics. In this review, screening and mutagenesis of microorganisms, heterologous expression, purification, characterization, structural analysis, immobilization, and protein engineering of fructosyltransferases are discussed. Future prospects in this field are also considered.
From Natural Methylation to Versatile Alkylations Using Halide Methyltransferases
Authors: Tang Qingyun , Pavlidis Ioannis V. , Badenhorst Christoffel P. S. , Bornscheuer Uwe T. 
Published: April 2021

AbstractHalide methyltransferases (HMTs) enable the enzymatic synthesis of S‐adenosyl‐l‐methionine (SAM) from S‐adenosyl‐l‐homocysteine (SAH) and methyl iodide. Characterisation of a range of naturally occurring HMTs and subsequent protein engineering led to HMT variants capable of synthesising ethyl, propyl, and allyl analogues of SAM. Notably, HMTs do not depend on chemical synthesis of methionine analogues, as required by methionine adenosyltransferases (MATs). However, at the moment MATs have a much broader substrate scope than the HMTs. Herein we provide an overview of the discovery and engineering of promiscuous HMTs and how these strategies will pave the way towards a toolbox of HMT variants for versatile chemo‐ and regioselective biocatalytic alkylations.
Efficient Synthesis of D‐Phenylalanine from L‐Phenylalanine via a Tri‐Enzymatic Cascade Pathway
Authors: Lu Cui , Zhang Sheng , Song Wei , Liu Jia , Chen Xiulai , Liu Liming , Wu Jing 
Published: April 2021

AbstractD‐phenylalanine is an important intermediate in food and pharmaceutical industries. Here, to enable efficient D‐phenylalanine biosynthesis from L‐phenylalanine, a tri‐enzymatic cascade was designed and reconstructedin vivo. The activity ofProteus vulgarismeso‐diaminopimelate dehydrogenase (PvDAPDH) toward phenyl pyruvic acid was identified as the limiting step. To overcome, the tension in the phenyl pyruvic acid side‐chain, PvDAPDH was engineered, generating PvDAPDHW121A/R181S/H227I, whose catalytic activity of 6.86 U mg−1represented an 85‐fold increase over PvDAPDH. Introduction of PvDAPDHW121A/R181S/H227I,P. mirabilisL‐amino acid deaminase, andBacillus megateriumglucose dehydrogenase inE. colienabled the production of 57.8 g L−1D‐phenylalanine in 30 h, the highest titer to date using 60 g L−1L‐phenylalanine as starting substrate, which meant a 96.3 % conversion rate and >99 % enantioselectivity on a 3‐L scale. The proposed tri‐enzymatic cascade provides a novel potential bio‐based approach for industrial production of D‐phenylalanine from cheap amino acids.
Spray Drying of Cellulose Nanofibers: Drying Kinetics Modeling of a Single Droplet and Particle Formation
Authors: Zaitone Belal Al , Al-Zahrani Abdulrahim 
Published: April 2021

AbstractMicroparticles embedded with cellulose nanofibers (CNFs) are produced via spray drying. The microdroplets are created in the spray dryer by atomization. The solvent evaporates from the droplet, and the dried particles are formed. The drying kinetics on the scale of one droplet is still not well understood. Drying of a single droplet CNF suspension was investigated in an acoustic levitator. The drying kinetics and morphology evolution during the drying process were obtained. The reaction engineering approach (REA) model provided a reasonable prediction of the drying kinetics. An absolute relative error of 2.5 % between the measured initial mass of the droplet and the REA model's estimated value was reported.
Plant‐Derived Stilbenoids as DNA‐Binding Agents: From Monomers to Dimers
Authors: Platella Chiara , Mazzini Stefania , Napolitano Ettore , Mattio Luce M. , Beretta Giovanni Luca , Zaffaroni Nadia , Pinto Andrea , Montesarchio Daniela , Dallavalle Sabrina 
Published: April 2021

AbstractStilbenoids are natural compounds endowed with several biological activities, including cardioprotection and cancer prevention. Among them, (±)‐trans‐δ‐viniferin, deriving fromtrans‐resveratrol dimerization, was investigated in its ability to target DNA duplex and G‐quadruplex structures by exploiting NMR spectroscopy, circular dichroism, fluorescence spectroscopy and molecular docking. (±)‐trans‐δ‐Viniferin proved to bind both the minor and major grooves of duplexes, whereas it bound the 3’‐ and 5’‐ends of a G‐quadruplex by stacking on the outer quartets, accompanied by rearrangement of flanking residues. Specifically, (±)‐trans‐δ‐viniferin demonstrated higher affinity for the investigated DNA targets than its monomeric counterpart. Additionally, the methoxylated derivatives of (±)‐trans‐δ‐viniferin andtrans‐resveratrol, i. e. (±)‐pterostilbene‐trans‐dihydrodimer andtrans‐pterostilbene, respectively, were evaluated, revealing similar binding modes, affinities and stoichiometries with the DNA targets as their parent analogues. All tested compounds were cytotoxic at μM concentration on several cancer cell lines, showing DNA damaging activity consistent with their ability to tightly interact with duplex and G‐quadruplex structures.
Effectiveness of Intermittent Preventive Treatment With Dihydroartemisinin‐Piperaqunine Against Malaria in Pregnancy in Tanzania: A Randomized Controlled Trial
Authors: Mlugu Eulambius M. , Minzi Omary , Kamuhabwa Appolinary A. R. , Aklillu Eleni 
Published: April 2021

Intermittent preventive treatment in pregnancy with sulfadoxine‐pyrimethamine (IPTp‐SP) to prevent malaria and adverse birth outcomes is threatened by Plasmodium falciparum resistance to sulfadoxine‐pyrimethamine. We investigated the effectiveness of intermittent preventive treatment in pregnancy with monthly dihydroartemisinin‐piperaquine (IPTp‐DHP) as an alternative option to IPTp‐SP. A total of 956 malaria‐free (malaria rapid diagnostic test (MRDT) negative) pregnant women from moderate malaria transmission areas in Tanzania were enrolled and randomized to receive monthly IPTp‐DHP (n = 478) or IPTp‐SP (n = 478) and followed for maternal and birth outcomes. The primary outcome was the prevalence of histopathologically confirmed placental malaria (active or past infection). Secondary outcomes were overall malaria at delivery, symptomatic‐malaria, parasitemia during pregnancy, and adverse birth outcomes as a composite of spontaneous‐abortion, premature birth, stillbirth, and low birth weight (LBW) fetal anemia. Outcome differences between treatment groups were expressed as the protective efficacy (PE), defined as 1‐prevalence ratios or 1‐incidence rate ratio. The prevalence of histopathologically confirmed placental malaria was significantly lower in IPTp‐DHP (2.5%, 12/478) than IPTp‐SP (8.2%, 39/478); PE = 69% (95% confidence interval (CI): 42–84, P < 0.001). The prevalence of maternal malaria at delivery was significantly lower in IPTp‐DHP (8.2%) than IPTp‐SP (18.2%, P < 0.001). The incidence per person‐years at risk for symptomatic‐malaria (0.02 vs. 0.12, P = 0.002) and parasitemia during pregnancy (0.28 vs. 0.67, P < 0.001) were significantly lower in the IPTp‐DHP group than in the IPTp‐SP group. The prevalence of any adverse birth outcomes (composite) was not significantly (P = 0.06) different between IPTp‐DHP (17.9%) and IPTp‐SP (23.8%). However, the prevalence of LBW (4.6% vs. 9.6%, P = 0.003) was significantly lower in IPTp‐DHP compared with IPTp‐SP. We report superior protective efficacy of monthly IPTp‐DHP against malaria in pregnancy and LBW than IPTp‐SP.
Theoretical analysis of annular laminar flows with MHD interaction driven by rotating co‐axial cylinder
Authors: Sasaki Ryo , Fujino Takayasu , Takana Hidemasa , Kobayashi Hiromichi 
Published: April 2021

AbstractTheoretical solution is derived for annular laminar flows with MHD interaction driven by a rotating co‐axial cylinder. The effects on the flow field and rotational torque are clarified by changing the radius ratio and the strength of MHD interaction. As the radius ratio increases, azimuthal flow velocity increases and approaches the plane Couette flow profile for weak MHD interaction. The azimuthal flow velocity, however, decreases as the MHD interaction increases, and the reverse flow emerges in large radial locations. As the MHD interaction increases, the rotational torque increases. A larger radius ratio leads to the larger sensitivity of the change in rotational torque.
Annual winter water‐level drawdowns influence physical habitat structure and macrophytes in Massachusetts, USA, lakes
Authors: Carmignani Jason R. , Roy Allison H. 
Published: April 2021

AbstractAnnual wintertime water‐level drawdowns are a common management strategy in recreational lakes; however, few studies have estimated their relative impact on lake littoral habitat among a set of typically co‐occurring anthropogenic stressors including lakeshore development and herbicide application. Within 21 Massachusetts, USA lakes that represented a drawdown magnitude gradient (0.07–2.26 m), we assessed depth‐specific littoral habitat (coarse wood, sediment, macrophytes) at two sites adjacent to forested or developed shorelines. Using generalized linear mixed models, we found coarse wood abundance and branching complexity was not correlated with drawdown magnitude but was primarily explained by the presence of lakeshore development. Drawdown magnitude was negatively correlated with silt cover and positively correlated with coarse substrate cover, with effects further varying by depth (0.5 m vs. 1 m). Macrophyte biomass and biovolume were negatively correlated with drawdown magnitude with effects also varying by depth for biomass. Macrophyte taxa with annual longevity strategies (e.g.,Najas flexilis) and amphibious growth forms increased in biomass proportions with drawdown magnitude. Distance‐based redundancy analyses suggested macrophyte taxa composition was driven by drawdown magnitude, coarse substrate, alkalinity, water transparency, and herbicide use. These results suggest the importance of water quality and depth on macrophyte assemblage responses to winter drawdowns and the potential to develop drawdown‐tolerant macrophyte assemblages. Altogether, understanding the unique impacts of anthropogenic stressors on littoral zone habitat across heterogeneous environmental lake conditions can help minimize impacts to lake ecological integrity while maintaining recreational value.
Agricultural crop consumption induces precocious maturity in deer by improving physical and reproductive performance
Authors: Hata Ayaka , Nakashita Rumiko , Anezaki Tomoko , Minami Masato , Fukue Yuko , Higuchi Naoko , Uno Hikaru , Nakajima Yasuhiro , Saeki Midori , Kozakai Chinatsu , Takada Mayura B. 
Published: April 2021

AbstractAnthropogenic foods such as agricultural crops have potential to give large impacts on wildlife populations. However, few studies have addressed the impact of anthropogenic food consumption on the individual performance and then population of long‐lived mammals such as large herbivores. In this study, we investigated the effect of agricultural crop consumption on the physical characteristics and reproductive performances of sika deer (Cervus nippon) in central Japan. To investigate the relative dietary contribution of agricultural crops for each individual, we performed nitrogen stable isotope analysis of bone collagen. Our results suggest that nitrogen stable isotope ratios (δ15N) could be used as an index of the relative dietary contribution of agricultural crops. The δ15N value of agricultural crops was much higher than that of wild plants and that of bone collagen varied widely among individuals. Deer ≤4 yr old that were more likely to consume agricultural crops tended to be larger and have a higher reproductive rate. In contrast, body size and reproductive rate did not vary according to the relative dietary contribution of agricultural crops in individuals ≥5 yr old. These results indicate that consumption of anthropogenic foods can induce precocious maturity in younger individuals by improving their physical characteristics and reproductive performance. Agricultural crop consumption is therefore likely to be an important factor in the population dynamics of large herbivores living in agricultural landscapes.