bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeting Signaling Pathways of Hyaluronic Acid and Integrin Receptors by Synergistic Combination Nanocomposites Inhibits Systemic Metastases and Primary Triple Negative Breast Cancer
Authors: Zhang Tian , Fu Chaoping , Alradwan Ibrahim , Yen TinYo , Lip HoYin , Cai Ping , Rauth Andrew M. , Zhang Liming , Wu Xiao Yu 
Published: April 2021

AbstractTriple negative breast cancer (TNBC) has a poor prognosis due to its aggressive nature, high incidence of distant metastasis, and lack of targets for effective therapy. Therefore, a novel multifunctional biopolymer‐anticancer drug combination nanomedicine is designed for the prevention of spontaneous metastasis while treating primary TNBC. Oligomeric hyaluronic acid (oHA) and doxorubicin (DOX) at a synergistic ratio against TNBC cells are co‐loaded in a polymer‐lipid hybrid nanoparticle (PLN) which is then functionalized with an internalizing cyclic peptide iRGD (iRGD‐DOX‐oHA‐PLN). iRGD conjugation enhances cellular uptake and cytotoxicity in vitro and nanoparticle (NP) accumulation in human TNBC tumors that overexpress integrins. NP‐delivered oHA inhibits cell migration and invasion in vitro via the intracellular release of oHA that interacts with the receptor for hyaluronan mediated motility and downregulates the phospho‐extracellular signal‐regulated kinase (p‐ERK) signaling pathway. Intravenously injected iRGD‐DOX‐oHA‐PLN significantly inhibits the growth of primary TNBC tumors in a mouse model and prevents spontaneous metastasis to the lungs and lymph nodes, superior to free solutions of DOX, oHA, or both and NP formulations loaded with DOX or oHA. These results suggest that iRGD‐DOX‐oHA‐PLN can be a promising bioactive polymer‐drug combination nanomedicine for the treatment of TNBC and prevention of its spontaneous metastasis.
Variants associated with urea cycle disorders in Japanese patients: Nationwide study and literature review
Authors: Kido Jun , Matsumoto Shirou , Sugawara Keishin , Sawada Takaaki , Nakamura Kimitoshi 
Published: April 2021

AbstractUrea cycle disorders (UCDs) are inherited metabolic diseases that lead to hyperammonemia with variable clinical manifestations. Using data from a nationwide study, we investigated the onset time, gene variants, clinical manifestations, and treatment of patients with UCDs in Japan. Of the 229 patients with UCDs diagnosed and/or treated between January 2000 and March 2018, identified gene variants and clinical information were available for 102 patients, including 62 patients with ornithine transcarbamylase (OTC) deficiency, 18 patients with carbamoyl phosphate synthetase 1 (CPS1) deficiency, 16 patients with argininosuccinate synthetase (ASS) deficiency, and 6 patients with argininosuccinate lyase (ASL) deficiency. A total of 13, 10, 4, and 5 variants in the OTC, CPS1, ASS, and ASL genes were respectively identified as novel variants, which were neither registered in ClinVar databases nor previously reported. The onset time and severity in patients with UCD could be predicted based on the identified gene variants in each patient from this nationwide study and previous studies. This genetic information may help in predicting the long‐term outcome and determining specific treatment strategies such as liver transplantation in patients with UCDs.
Tailored Synthesis of Skeletally Diverse Stemona Alkaloids through Chemoselective Dyotropic Rearrangements of β‐Lactones
Authors: Guo Zhen , Bao Ruiyang , Li Yuanhe , Li Yunshan , Zhang Jingyang , Tang Yefeng 
Published: April 2021

AbstractThe collective synthesis of skeletally diverse Stemona alkaloids featuring tailored dyotropic rearrangements of β‐lactones as key elements is described. Specifically, three typical 5/7/5 tricyclic skeletons associated with stemoamide, tuberostemospiroline and parvistemonine were first accessed through chemoselective dyotropic rearrangements of β‐lactones involving alkyl, hydrogen, and aryl migration, respectively. By the rational manipulation of substrate structures and reaction conditions, these dyotropic rearrangements proceeded with excellent efficiency, good chemoselectivity and high stereospecificity. Furthermore, several polycyclic Stemona alkaloids, including saxorumamide, isosaxorumamide, stemonine and bisdehydroneostemoninine, were obtained from the aforementioned tricyclic skeletons through late‐stage derivatizations. A novel visible‐light photoredox‐catalyzed formal [3+2] cycloaddition was also developed, which offers a valuable tool for accessing oxaspirobutenolide and related scaffolds.
Acridino[2,1,9,8‐klmna]acridine Bisimides: An Electron‐Deficient π‐System for Robust Radical Anions and n‐Type Organic Semiconductors
Authors: Tajima Keita , Matsuo Kyohei , Yamada Hiroko , Seki Shu , Fukui Norihito , Shinokubo Hiroshi 
Published: April 2021

AbstractWe report the synthesis and properties of acridino[2,1,9,8‐klmna]acridine bisimide (AABI), a nitrogen‐doped anthanthrene with two imide functionalities. AABI exhibits excellent electron affinity as evident by its low‐lying LUMO level (−4.1 eV vs. vacuum). Single‐electron reduction of one AABI derivative afforded the corresponding radical anion, which was stable under ambient conditions. Photoconductivity measurements suggest that the intrinsic electron mobility of an N‐phenethyl AABI derivative obeys a band‐transport model. Accordingly, an electron mobility of 0.90 cm2 V−1 s−1 was attained with the corresponding single‐crystal organic field‐effect transistor (OFET) device. The vacuum‐deposited OFET device consisting of a polycrystalline sample exhibited high electron mobility of up to 0.27 cm2 V−1 s−1 even in air. This study demonstrates that dual incorporation of both imide substituents and imine‐type nitrogen atoms is an effective strategy to create novel electron‐deficient π‐systems.
Persistent peri‐Heptacene: Synthesis and In Situ Characterization
Authors: Ajayakumar M. R. , Ma Ji , Lucotti Andrea , Schellhammer Karl Sebastian , Serra Gianluca , Dmitrieva Evgenia , Rosenkranz Marco , Komber Hartmut , Liu Junzhi , Ortmann Frank , Tommasini Matteo , Feng Xinliang 
Published: April 2021

Abstractn‐peri‐Acenes (n‐PAs) have gained interest as model systems of zigzag‐edged graphene nanoribbons for potential applications in nanoelectronics and spintronics. However, the synthesis of n‐PAs larger than peri‐tetracene remains challenging because of their intrinsic open‐shell character and high reactivity. Presented here is the synthesis of a hitherto unknown n‐PA, that is, peri‐heptacene (7‐PA), in which the reactive zigzag edges are kinetically protected with eight 4‐tBu‐C6H4 groups. The formation of 7‐PA is validated by high‐resolution mass spectrometry and in situ FT‐Raman spectroscopy. 7‐PA displays a narrow optical energy gap of 1.01 eV and exhibits persistent stability (t1/2≈25 min) under inert conditions. Moreover, electron‐spin resonance measurements and theoretical studies reveal that 7‐PA exhibits an open‐shell feature and a significant tetraradical character. This strategy could be considered a modular approach for the construction of next‐generation (3 N+1)‐PAs (where N≥3).
Can a Procedure for the Growth of Single‐layer Graphene on Copper be used in Different Chemical Vapor Deposition Reactors?
Authors: Hakami Mariam , Deokar Geetanjali , Smajic Jasmin , Batra Nitin M. , Costa Pedro M. F. J. 
Published: April 2021

AbstractIn the last decade, catalytic chemical vapor deposition (CVD) has been intensively explored for the growth of single‐layer graphene (SLG). Despite the scattering of guidelines and procedures, variables such as the surface texture/chemistry of catalyst metal foils, carbon feedstock, and growth process parameters have been well‐scrutinized. Still, questions remain on how best to standardize the growth procedure. The possible correlation of procedures between different CVD setups is an example. Here, two thermal CVD reactors were explored to grow graphene on Cu foil. The design of these setups was entirely distinct, one being a “showerhead” cold‐wall type, whereas the other represented the popular “tubular” hot‐wall type. Upon standardizing the Cu foil surface, it was possible to develop a procedure for cm2‐scale SLG growth that differed only by the carrier gas flow rate used in the two reactors.
Aptamers: The Powerful Molecular Tools for Virus Detection
Authors: Han Cong , Li Qian , Ji Haishuo , Xing Wenping , Zhang Limin , Zhang Liyun 
Published: April 2021

AbstractAptamers are short single‐stranded DNA or RNA oligonucleotides selected by the technique of systematic evolution of ligands by exponential enrichment (SELEX). Aptamers have been demonstrated to bind various targets from small‐molecule to cells or even tissues in the way of antibodies. Thus, they are called chemical antibodies. We summarize and evaluate recent developments in aptamer‐based sensors (for short aptasensors) for virus detection in this review. These aptasensors are mainly classified into optical and electronic aptasensors based on the type of transducer. Nowadays, the smartphone has become the most widely used mobile device with billions of users worldwide. Considering the ongoing COVID‐19 outbreak, smartphone‐based aptasensors for a portable and point‐of‐care test (POCT) of COVID‐19 detection will be of great importance in the future.
Does quality management improve the internalization of environmental practices? An empirical study in Africa
Authors: Tayo Tene Christian Valery , Boiral Olivier , Heras‐Saizarbitoria Iñaki 
Published: April 2021

AbstractThis article analyzes the role of quality management in the internalization of environmental practices. A qualitative study based on interviews with 35 practitioners was conducted in three African countries (Cameroon, Senegal, and Ivory Coast). The results highlight the contrasting roles played by the main reference model for quality management—International Organization for Standardization (ISO) 9001—in the internalization of the international standard for corporate environmental management—ISO 14001—with positive points related to formal and documentary aspects and perverse effects such as increased bureaucracy and a focus on quality at the expense of the environment. The results also point to four configurations of integration of environmental practices according to the level of quality management internalization and the level of institutional pressure to adopt corporate environmental management: poor integration, partial integration, substantial integration, and sustainable integration.
Wanting sex and willing to kill: Examining demographic and cognitive characteristics of violent “involuntary celibates”
Authors: Williams D. J. , Arntfield Michael , Schaal Kaleigh , Vincent Jolene 
Published: April 2021

AbstractOver the past several years, an online community of self‐described “incels,” referring to involuntary celibates, has emerged and gained increased public attention. Central to the guiding incel ideology and master narrative are violent misogynistic beliefs and an attitude of entitlement, based on male gender and social positioning, with respect to obtaining desired and often illusory sexual experiences. While violence and hate speech within the incel community are both common, there exists a notable subset of incels who have been willing to act on those violent beliefs through the commission of acts of multiple murder. This study explores the demographic, cognitive, and other characteristics of seven self‐identified incels who have attempted and/or successfully completed homicide. The findings suggest that although self‐perceptions tend to reflect either grandiosity or self‐deprecation, homicidal incels share similar demographic characteristics and dense common clusters of neutralization techniques, cognitive distortions, and criminal thinking errors.
Resveratrol is an inhibitor of sodium‐dependent inorganic phosphate transport in triple‐negative MDA‐MB‐231 breast cancer cells
Authors: Lacerda‐Abreu Marco Antonio , Russo‐Abrahão Thais , Meyer‐Fernandes José Roberto 
Published: April 2021

AbstractMetastasis is a major cause of death in patients with breast cancer. A growing body of evidence has demonstrated the antitumour effects of resveratrol, a non‐flavonoid polyphenol. Resveratrol inhibits metastatic processes, such as the migration and invasion of cancer cells. In several cancer types, the importance of inorganic phosphate (Pi) for tumor progression has been demonstrated. The metastatic process in breast cancer is associated with Na+‐dependent Pi transporters. In this study, we demonstrate, for the first time, that resveratrol inhibits the Na+‐dependent Pi transporter. Results from kinetic analysis shows that resveratrol inhibits Na+‐dependent Pi transport non‐competitively. Resveratrol also inhibits adhesion/migration in MDA‐MB‐231 cells, likely related to inhibition of the Na+‐dependent Pi transporter.
Wet‐Spun PEDOT/CNT Composite Hollow Fibers as Flexible Electrodes for H2O2 Production**
Authors: Cui Qing , Bell Daniel Josef , Wang Siqi , Mohseni Mojtaba , Felder Daniel , Lölsberg Jonas , Wessling Matthias 
Published: April 2021

AbstractThe electrochemical synthesis of hydrogen peroxide (H2O2) using the oxygen reduction reaction (ORR) requires highly catalytic active, selective, and stable electrode materials to realize a green and efficient process. The present publication shows for the first time the application of a facile one‐step bottom‐up wet‐spinning approach for the continuous fabrication of stable and flexible tubular poly(3,4‐ethylene dioxythiophene) (PEDOT : PSS) and PEDOT : PSS/carbon nanotube (CNT) hollow fibers. Additionally, electrochemical experiments reveal the catalytic activity of acid‐treated PEDOT : PSS and its composites in the ORR forming hydrogen peroxide for the first time. Under optimized conditions, the composite electrodes with 40 wt % CNT loading could achieve a high production rate of 0.01 mg/min/cm2 and a current efficiency of up to 54 %. In addition to the high production rate, the composite hollow fiber has proven its long‐term stability with 95 % current retention after 20 h of hydrogen peroxide production.
Tuning the Anodic and Cathodic Dissolution of Gold by Varying the Surface Roughness
Authors: Chinnaiah Jeyabharathi , Kasian Olga , Dekshinamoorthy Amuthan , Vijayaraghavan Saranyan , Mayrhofer Karl J. J. , Cherevko Serhiy , Scholz Fritz 
Published: April 2021

AbstractThis work presents the reactivity and dissolution of an as‐polished and electrochemically pre‐treated polycrystalline Au electrode, which is used as a model system. The effect of the electrochemical pre‐treatment in corrosive 0.37 M HCl solutions on the Au surface roughness and dissolution is investigated by varying the number of pre‐treatment steps at 1.16 V against the reversible hydrogen electrode. It is shown that the first 10 s pre‐treatment of the as‐polished Au results in a higher surface roughness and thus higher electrochemically active surface area (ECSA) than that of the as‐polished Au. With the subsequent pre‐treatments, however, the ECSA is gradually decreasing reaching a steady value. The dissolution rate of the pre‐treated Au electrodes upon potential cycling in 0.1 M H2SO4 is determined by in situ inductively coupled plasma mass spectrometry. A non‐linear dependence of Au dissolution amount is found with respect to the number of pre‐treatments. The overall total Au dissolution rate follows a similar trend as ECSA/roughness. However, an important difference in the dissolution behavior is identified with respect to dissolution processes during Au oxidation (anodic dissolution) and Au reduction (cathodic dissolution): the former is more sensitive to the surface roughness. Thus, the ratio between Au anodic and cathodic dissolution amounts decreases substantially with decrease in surface roughness. This finding is explained by the slow and fast dissolution kinetics for anodic and cathodic processes, respectively. Current work further advances our understanding of the complex Au dissolution mechanism.
Click Chemistry in Ultra‐high Vacuum – Tetrazine Coupling with Methyl Enol Ether Covalently Linked to Si(001)
Authors: Glaser Timo , Meinecke Jannick , Freund Lukas , Länger Christian , Luy Jan‐Niclas , Tonner Ralf , Koert Ulrich , Dürr Michael 
Published: April 2021

AbstractThe additive‐free tetrazine/enol ether click reaction was performed in ultra‐high vacuum (UHV) with an enol ether group covalently linked to a silicon surface: Dimethyl 1,2,4,5‐tetrazine‐3,6‐dicarboxylate molecules were coupled to the enol ether group of a functionalized cyclooctyne which was adsorbed on the silicon (001) surface via the strained triple bond of cyclooctyne. The reaction was observed at a substrate temperature of 380 K by means of X‐ray photoelectron spectroscopy (XPS). A moderate energy barrier was deduced for this click reaction in vacuum by means of density functional theory based calculations, in good agreement with the experimental results. This UHV‐compatible click reaction thus opens a new, flexible route for synthesizing covalently bound organic architectures.
Synergistic Effect of NiLDH@YZ Hybrid and Mechanochemical Agitation on Glaser Homocoupling Reaction
Authors: Mokhtar Mohamed , Alzhrani Ghalia , Aazam Elham S. , Saleh Tamer S. , Al‐Faifi Sulaiman , Panja Subir , Maiti Debabrata 
Published: April 2021

AbstractHerein, we report the synthesis of nickel‐layered double hydroxide amalgamated Y‐zeolite (NiLDH@YZ) hybrids and the evaluation of the synergistic effect of various NiLDH@YZ catalysts and mechanochemical agitation on Glaser homocoupling reactions. Nitrogen adsorption‐desorption experiments were carried out to estimate the surface area and porosity of NiLDH@YZ hybrids. The basicity and acidity of these hybrids were determined by CO2‐TPD and NH3‐TPD experiments respectively and this portrayed good acid‐base bifunctional feature of the catalysts. The NiLDH@YZ‐catalyzed mechanochemical Glaser coupling reaction achieved best yield of 83 % for the 0.5NiLDH@0.5YZ hybrid after 60 min of agitation, which revealed the highest acid‐base bifunctional feature compared to all the investigated catalysts. The developed catalyst has proven itself as a robust and effective candidate that can successfully be employed up to four catalytic cycles without significant loss in catalytic activity, under optimized reaction conditions. This work demonstrated a new strategy for C−C bond formation enabled by the synergy between mechanochemistry and heterogeneous catalysis.
Aryne Multicomponent Reactions by Directed C−H Activation
Authors: Sunnam Sunil Kumar , Belani Jitendra D. 
Published: April 2021

AbstractArylation via ortho C−H activation by the aid of directing groups has been explored recently by many researchers. Herein, a palladium‐catalyzed C−H arylation using 8‐aminoquinoline as a bidentate directing group has been developed. The reaction furnishes only C−H arylation, unlike previous methods where cyclization to corresponding isoquinolones is observed. More interestingly, sequential C−H functionalization was observed when methylacrylate and acrylonitrile was added; this led to C−H olefination with the aryl group, which was installed from the aryne precursor.
Synthesis of Lignans Based on a Borate‐mediated One‐pot Sequential Suzuki‐Miyaura Coupling of Cyclic Boranes
Authors: Sato Ko , Tanaka Hiroshi 
Published: April 2021

AbstractLignans are a group of polyphenolic phytochemicals that possess a large spectrum of chemical structures and biological activities. Here the syntheses of lignans – anwulignan, burseran, dehydroxycubebin, ruburisandrin B, and sesamin – are achieved based on a borate‐mediated one‐pot sequential Suzuki‐Miyaura coupling of cis‐ and trans‐fused bicyclic boranes, which were prepared by diastereoselective cyclic hydroboration of exo‐cyclic diene with cyclopentyl‐ and thexylboranes, respectively. A one‐pot sequential Suzuki‐Miyaura coupling of each cyclic borate with various aryl bromides initiated by activation of the cyclic borane with the carbon nucleophile provided 2,3‐dibenzylbutane derivatives with different aromatic substituents. Finally, the syntheses of naturally occurring lignans were accomplished in several steps from the products of Suzuki‐Miyaura coupling.
A Stable Homoleptic Divinyl Tetrelene Series
Authors: Roy Matthew M. D. , Baird Samuel R. , Dornsiepen Eike , Paul Lucas A. , Miao Linkun , Ferguson Michael J. , Zhou Yuqiao , Siewert Inke , Rivard Eric 
Published: April 2021

AbstractThe synthesis of the new bulky vinyllithium reagent (MeIPr=CH)Li, (MeIPr=[(MeCNDipp)2C]; Dipp=2,6‐iPr2C6H3) is reported. This vinyllithium precursor was found to act as a general source of the anionic 2σ, 2π‐electron donor ligand [MeIPr=CH]−. Furthermore, a high‐yielding route to the degradation‐resistant SiII precursor MeIPr⋅SiBr2 is presented. The efficacy of (MeIPr=CH)Li in synthesis was demonstrated by the generation of a complete inorganic divinyltetrelene series (MeIPrCH)2E: (E=Si to Pb). (MeIPrCH)2Si: represents the first two‐coordinate acyclic silylene not bound by heteroatom donors, with dual electrophilic and nucleophilic character at the SiII center noted. Cyclic voltammetry shows this electron‐rich silylene to be a potent reducing agent, rivalling the reducing power of the 19‐electron complex cobaltocene (Cp2Co).
Jens Weitkamp's Joy of Thinking
Authors: de Mijolla‐Mellor Sophie 
Published: April 2021

AbstractWith the evocation of Jens Weitkamp's life and character this paper tackles from the psychoanalytic theory of Sublimation (Sublimierung) the nature of the specific pleasure taken by researchers. They realize passionately their own driving forces but thus indirectly contribute to culture and progress of humanity. Any sublimated drive to knowledge is based on the acceptance that knowledge always implies simultaneously a future knowledge to be. This specific pleasure is based not on sexual abstinence as stated by Freud but on the renunciation to a stable security, enjoying a mobile order instead of fixity. Nevertheless, the sublimatory derivation that ensures the transition from destructiveness to exploratory curiosity is conditioned by the ability of the researcher not to destroy the object but only its enigmatic character.
Dilute gas‐particle suspension in a diffuser: A two‐fluid modelling approach
Authors: Senapati Santosh Kumar , Dash Sukanta Kumar 
Published: April 2021

AbstractThe present study evaluates the loss coefficient of a diffuser carrying a gas–solid mixture with the volume fraction of the solid in the medium to upper limits of the dilute phase flow (solid volume fraction in the range of 0.005–0.10). In light of the computational analysis, it is observed that an increase in the concentration of the solid phase always helps in overcoming the losses despite a significant dissipation of energy due to collisions. Moreover, the loss coefficient lessens as the solid‐phase density reduces. Under the operating conditions where the collisions become significant, a critical particle size (≈200 μm) is obtained. The loss coefficient mitigates gradually with an increase in the particle size up to this value but enhances beyond it. An increase in the diffuser angle enhances the loss; however, its effect becomes less prominent as the solid volume fraction increases (typically for solid volume fraction greater than or equal to 0.02).