bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acetate overflow metabolism regulates a major metabolic shift after glucose depletion in Escherichia coli
Authors: Shimada Tomohiro , Nakazawa Kohta , Tachikawa Tomoyuki , Saito Natsumi , Niwa Tatsuya , Taguchi Hideki , Tanaka Kan 
Published: June 2021

Acetate overflow refers to the metabolism by which a large part of carbon incorporated as glucose into Escherichia coli cells is catabolized and excreted as acetate into the medium. We previously found that mutants for the acetate overflow pathway enzymes phosphoacetyltransferase (Pta) and acetate kinase (AckA) showed significant diauxic growth after glucose depletion in E. coli. Here, we analyzed the underlying mechanism in the pta mutant. Proteomic and other analyses revealed an increase in pyruvate dehydrogenase complex subunits and a decrease in glyoxylate shunt enzymes, which resulted from pyruvate accumulation. Since restoration of these enzyme levels by overexpressing PdhR (pyruvate‐sensing transcription factor) or deleting iclR (gene encoding a pyruvate‐ and glyoxylate‐sensing transcription factor) alleviated the growth lag of the pta mutant after glucose depletion, these changes were considered as the reason for the phenotype. Given the evidence for decreased coenzyme A (HS‐CoA) levels in the pta mutant, the growth inhibition after glucose depletion was partly explained by limited availability of HS‐CoA in the cell. The findings provide insights into the role of acetate overflow in metabolic regulation, which may be useful for biotechnological applications.
Tailored Mechanical Metamaterials with Programmable Quasi‐Zero‐Stiffness Features for Full‐Band Vibration Isolation
Authors: Zhang Quan , Guo Dengke , Hu Gengkai 
Published: June 2021

AbstractQuasi‐zero‐stiffness (QZS) isolators of high‐static‐low‐dynamic stiffness play an important role in ultra‐low frequency vibration mitigation. While the current designs of QZS mainly exploit the combination of negative‐stiffness corrector and positive‐stiffness element, and only have a single QZS working range, here a class of tailored mechanical metamaterials with programmable QZS features is proposed. These programmed structures contain curved beams with geometries that are specifically designed to enable the prescribed QZS characteristics. When these metamaterials are compressed, the curved beams reach the prescribed QZS working range in sequence, thus enabling tailored stair‐stepping force‐displacement curves with multiple QZS working ranges. Compression tests demonstrate that a vast design space is achieved to program the QZS features of the metamaterials. Further vibration tests confirm the ultra‐low frequency vibration isolation capability of the proposed mechanical metamaterials. The mechanism of QZS stems solely from the structural geometry of the curved beams and is therefore materials‐independent. This design strategy opens a new avenue for innovating compact and scalable QZS isolators with multiple working ranges.
Fabrication of Citric Acid/RGD Multilayers on Mg‐Zn‐Y‐Nd Alloy via Layer‐by‐Layer Self‐Assembly for Promoting Surface Biocompatibility
Authors: Kou Fang , Liu Changsheng , Wang Liguo , Yasin Aqeela , Li Jingan , Guan Shaokang 
Published: June 2021

AbstractMagnesium (Mg) alloy, an important biodegradable material widely investigated on cardiovascular stent, is restricted for further application due to some limited functions, such as the excessively rapid degradation rate, poor hemocompatibility, and delayed re‐endothelialization. To overcome these shortcomings, surface modification with biomolecules has attracted much attention. In this study, the multifunctional coatings of citric acid (CA) and Arg‐Gly‐Asp (RGD) via layer‐by‐layer self‐assembly are immobilized onto the polydopamine (PDA) deposited surface which is passivated with hydrofluoric acid (HF) solution before. The basic characterization results suggest that PDA/(CA‐RGD)2 coating exhibits a rich‐in‐amine and hydrophilic surface. The corrosion current density of PDA/(CA‐RGD)2 exposed to simulated body fluid is reduced by 95.65% from 1.586 × 10−4 to 6.894 × 10−6 A cm−2 under the protection of the dense MgF2 layer and multifunctional coatings. Besides, inhibition on platelet adhesion, hemolysis rates, and fibrinogen adsorption also prove the enhanced hemocompatibility of the PDA/(CA‐RGD)2 coatings. Meanwhile, the human umbilical vein endothelial cells (HUVECs) and smooth muscle cells (SMCs) culture results jointly prove the excellent endothelialization performance of functionalized samples. In conclusion, the above mentioned results reveal that the functionalized surface of PDA/(CA‐RGD)2 displays better overall performance, indicating a preferable application for cardiovascular stents.
CO2‐Induced 2D Ni‐BDC Metal–Organic Frameworks with Enhanced Photocatalytic CO2 Reduction Activity
Authors: Chang Hongwei , Zhou Yannan , Zhang Suoying , Zheng Xiaoli , Xu Qun 
Published: June 2021

AbstractThe rational design of 2D metal–organic framework (MOF) nanosheets with high active exposed surfaces and ultrathin thickness is a critical issue for CO2 reduction. How to fabricate 2D MOFs and simultaneously fulfill the strong adsorption and activation of CO2 molecules is a great challenge. Here, it is reported that CO2 molecules can help to fabricate single‐layer [Ni3(OH)2(1,4‐BDC)2‐(H2O)4]·2H2O, BDC = 1,4‐benzenedicarboxylate, (Ni‐BDC) MOF nanosheets with large sizes and uniform thickness by exchanging with the coordinated H2O molecules at Ni sites and further orientated chemically adsorption on it. CO2 molecules can not only help break the interlayer hydrogen bond of bulk materials realizing the successful transformation from 3D to 2D, but also contribute to expose the (200) planes with highly active in photocatalytic CO2‐to‐CO conversion, and a high production rate of 104 mmol g−1 h−1 and a high Faraday efficiency of 96.8% can be obtained. This strategy provides a novel prototypical model based on the strong interaction between metal active centers and reactive molecules to obtain 2D MOFs with high quality and activity.
Plasma‐Assisted Deposition of Silk Fibroin on Different Surfaces
Authors: Arkhangelskiy Artem , Maniglio Devid , Bucciarelli Alessio , Yadavalli Vamsi K. , Quaranta Alberto 
Published: June 2021

AbstractThe development of simple and versatile methods for the deposition of biocompatible coatings to protect or functionalize a range of materials with different shapes is an important challenge. In this study, a versatile, room‐temperature process is presented for the deposition of silk fibroin on different materials viz., glass, polyethylene terephthalate, Ti alloy, and poly(dimethylsiloxane). Coating with thin fibroin films is achieved using an atmospheric plasma torch, wherein a silk‐fibroin aerosol solution is used as the working gas. The method consists of two sequential processes: plasma modification of the surface, followed by plasma‐assisted deposition. This allows enhanced adhesion of the protein to the underlying surfaces, and the deposition even on non‐planar and flexible substrates. The deposited films are characterized by optical microscopy, atomic force microscopy, and scanning electron microscopy. Primary and secondary structures of the surface‐attached fibroin films are investigated by Fourier transform infrared spectroscopy. The proposed approach offers a tunable and controllable strategy for the controlled deposition of proteins on complex surfaces, for a wide range of biomedical and technological applications, including dentistry and bioelectronics.
Natural Origin Biomaterials for 4D Bioprinting Tissue‐Like Constructs
Authors: Costa Patrícia D. C. , Costa Dora C. S. , Correia Tiago R. , Gaspar Vítor M. , Mano João F. 
Published: June 2021

AbstractLeveraging 4D biofabrication for engineering biomimetic living constructs is rapidly emerging as a valuable strategy for recapitulating native tissue dynamics, via on‐demand stimuli, or in a naturally evolving mode. Carefully selecting smart materials with suitable responsiveness and cell‐supporting functionalities is crucial to take full operational advantage of this next‐generation technology. Recent endeavors combining naturally available polymers or hybrid smart materials improve the potential to manufacture volumetrically defined, cell‐rich constructs that may display stimuli–responsive properties, shape memory/shape morphing features, and/or dynamic motion in time. In this review, natural origin biomaterials and the stimuli that can be exploited for granting dynamic morphological features and functionalities post‐printing are highlighted. A broad overview of recent reports focusing on 4D‐bioprinted constructs for tissue engineering and regenerative medicine is also provided and critically discussed in light of current challenges, as well as foreseeable advances. It is envisioned that upon assurance of key regulatory demands, such technology will become translatable to numerous biomedical applications that require fabrication of constructs with dynamic functionality.
Radiative Rate Modulation Reveals Near‐Unity Quantum Yield of Graphene Quantum Dots
Authors: Ghosh Subhabrata , Oleksiievets Nazar , Enderlein Jörg , Chizhik Alexey I. 
Published: June 2021

AbstractA fundamental but difficult to assess photophysical property of quantum emitters is their fluorescence quantum yield. It describes how efficiently a fluorophore converts absorbed light into fluorescence. Conventional measurements of quantum yield are prone to errors when the sample contains also absorbing but non‐luminescent species. This is, however, commonly encountered in complex systems such as graphene quantum dots that are either optically inactive themselves or contain impurities formed during nanoparticle synthesis. Their presence can lead to a gross underestimation of the quantum yield of the luminescent species. Here, a plasmonic nanocavity‐based method is used to measure absolute quantum yields of graphene quantum dots by modulating their radiative rate. This method is insensitive to the presence of non‐luminescent species and allows to measure absolute values of quantum yield of the luminescent nanoparticles. The determined quantum yields of nearly 100% significantly exceed previously reported values. By comparing these values with those obtained with a comparative method, the average size and relative concentration of the non‐luminescent particles is determined. Thus, this nanocavity‐based method offers a new way for not only measuring absolute values of quantum yield, but also for assessing the fraction of optically inactive species within a sample.
Recent Advances in N‐Heterocyclic Carbene Catalyzed Oxidative Cyclization for the Formation of Heterocycles
Authors: Pavithra T. , Devi E. Sankari , Maheswari C. Uma 
Published: June 2021

AbstractOxidative N‐heterocyclic carbene catalyst mediated cyclization proved to be an efficient strategy for the construction of various N‐ and O‐ heterocycles. Among several metal‐free methods available for the construction of heterocyclic compounds, oxidative NHC catalysis proved to be an elegant and efficient strategy as several enantioenriched compounds with excellent enantioselectivities can be synthesized in good yields. The most common method of the generation of these heterocycles proceeds via the commonly encountered intermediate in oxidative NHC catalysis (i. e.) acyl azolium intermediate. This intermediate proves to be the active species as it can undergo reaction with suitable substrates leading to the formation of numerous N‐ and O‐ heterocycles. Herein, recent reports on different strategies that enable formal [2+2], [3+2], [3+3], [4+2] or [4+3] annulations between the incoming substrates and acyl azolium species or other active intermediates which can add to suitable substrate leading to various heterocycles were summarized.
Artificial Light‐Harvesting Systems Based on AIEgen‐branched Rotaxane Dendrimers for Efficient Photocatalysis
Authors: Li Wei‐Jian , Wang Xu‐Qing , Zhang Dan‐Yang , Hu Yi‐Xiong , Xu Wei‐Tao , Xu Lin , Wang Wei , Yang Hai‐Bo 
Published: June 2021

AbstractAiming at the construction of novel platform for efficient light harvesting, the precise synthesis of a new family of AIEgen‐branched rotaxane dendrimers was successful realized from an AIEgen‐functionalized [2]rotaxane through a controllable divergent approach. In the resultant AIE macromolecules, up to twenty‐one AIEgens located at the tails of each branches, thus making them the first successful example of AIEgen‐branched dendrimers. Attributed to the solvent‐induced switching feature of the rotaxane branches, the integrated rotaxane dendrimers displayed interesting dynamic feature upon the aggregation‐induced emission (AIE) process. Moreover, novel artificial light‐harvesting systems were further constructed based on these AIEgen‐branched rotaxane dendrimers, which revealed impressive generation‐dependent photocatalytic performances for both photooxidation reaction and aerobic cross‐dehydrogenative coupling (CDC) reaction.
Eckenverknüpfung von drei (BO4)‐Tetraedern in einem Borosulfat: Synthese, Kristallstruktur und quantenchemische Untersuchung von Sr[B3O(SO4)4(SO4H)]
Authors: Pasqualini Leonard C. , Huppertz Hubert , Je Minyeong , Choi Heechae , Bruns Jörn 
Published: June 2021

AbstractBorosulfate werden als Silicat‐analoge Materialien klassifiziert. Trotz der begrenzten Zahl kristallographisch charakterisierter Verbindungen ist deren strukturelle Vielfalt bereits jetzt beeindruckend. Die anionischen Substrukturen der Borosulfate weisen eckenverknüpfte (BO4)‐ und (SO4)‐Tetraeder auf, während Verbrückungen zwischen zwei (SO4)‐ oder auch zwischen zwei (BO4)‐Tetraedern selten sind. Mit Sr[B3O(SO4)4(SO4H)] wird nun über das erste Borsulfat berichtet, in welchem gleich drei (BO4)‐Tetraedern mittels einer Eckenverknüpfung über ein gemeinsames Sauerstoffatom verknüpft sind. DFT‐Rechnungen ergänzen die experimentellen Untersuchungen. Bader‐Ladungen (berechnet für alle Atome), sowie Ladungsdichteberechnungen geben Hinweise auf die Elektronenverteilung innerhalb der anionischen Substruktur. Zustandsdichte‐Rechnungen unterstützen die Interpretation der Bindungssituation.
A Near‐Infrared‐II Emissive Chromium(III) Complex
Authors: Sinha Narayan , Jiménez Juan‐Ramón , Pfund Björn , Prescimone Alessandro , Piguet Claude , Wenger Oliver S. 
Published: June 2021

AbstractThe combination of π‐donating amido with π‐accepting pyridine coordination units in a tridentate chelate ligand causes a strong nephelauxetic effect in a homoleptic CrIII complex, which shifts its luminescence to the NIR‐II spectral range. Previously explored CrIII polypyridine complexes typically emit between 727 and 778 nm (in the red to NIR‐I spectral region), and ligand design strategies have so far concentrated on optimizing the ligand field strength. The present work takes a fundamentally different approach and focusses on increasing metal–ligand bond covalence to shift the ruby‐like 2E emission of CrIII to 1067 nm at 77 K.
mTORC1 and ferroptosis: Regulatory mechanisms and therapeutic potential
Authors: Lei Guang , Zhuang Li , Gan Boyi 
Published: June 2021

AbstractFerroptosis, a form of regulated cell death triggered by lipid hydroperoxide accumulation, has an important role in a variety of diseases and pathological conditions, such as cancer. Targeting ferroptosis is emerging as a promising means of therapeutic intervention in cancer treatment. Polyunsaturated fatty acids, reactive oxygen species, and labile iron constitute the major underlying triggers for ferroptosis. Other regulators of ferroptosis have also been discovered recently, among them the mechanistic target of rapamycin complex 1 (mTORC1), a central controller of cell growth and metabolism. Inhibitors of mTORC1 have been used in treating diverse diseases, including cancer. In this review, we discuss recent findings linking mTORC1 to ferroptosis, dissect mechanisms underlying the establishment of mTORC1 as a key ferroptosis modulator, and highlight the potential of co‐targeting mTORC1 and ferroptosis in cancer treatment. This review will provide valuable insights for future investigations of ferroptosis and mTORC1 in fundamental biology and cancer therapy.
Integrative analysis of TP73 profile prognostic significance in WHO grade II/III glioma
Authors: Chen Yanming , Wang Ye , He Qiheng , Wang Wen , Zhang Tan , Wang Zhongyong , Dong Jun , Lan Qing , Zhao Jizong 
Published: June 2021

AbstractDue to the extremely intrinsic heterogeneity among glioma patients, the outcomes of these patients are tremendously different. Therefore, the exploitation of novel biomarker classification of glioma is vitally important for deep insight into the essence and predicting the prognosis of glioma. We aim to analyze the correlation between TP73 mRNA expression, DNA methylated alteration and the prognosis of WHO grade II/III glioma, utilizing bioinformatics to evaluate its significance as a risk‐factor in predicting the prognosis of these glioma patients. The analysis found that TP73 expression was positively correlated with the grade of glioma, and showed a strong correlation with glioma molecular classification, which revealed significantly higher TP73 expression in IDH‐wildtype than in IDH‐mutant subtype of WHO grade II/III glioma. Cox regression analysis indicated that high expression of TP73 shared an independent high‐risk factor impacting the prognosis of WHO grade II/III glioma. We discovered 8 DNA promoter methylation sites with prognostic significance, which were negatively associated with TP73 expression, and positively associated with beneficial overall survival (OS) and progression‐free survival (PFS). Integrating with four independent glioma datasets, subsequent Meta‐analysis verified that low expression of TP73 was closely related to favorable OS, especially in IDH‐mutant subtype. Moreover, we found that 1p/19qCodel/TP73low subgroup shared the most favorable OS, 1p/19qNon−codel/TP73high subgroup suffered the worst OS. Meanwhile, the enrichment analysis of TP73‐related differential mRNAs demonstrated that TP73 aberration in WHO grade II/III glioma might be closely related to cell cycle and P53 signaling pathways. Finally, TP73 expression of 53 glioma specimens was measured by qRT‐PCR, which was consistent with the previous analytical result, and TP73 high‐expression subgroup suffered worse PFS than TP73 low‐expression subgroup. In summary, our funding supports that TP73 gene can perform as a reliable biomarker to evaluate the survival outcome of patients diagnosed with WHO grade II/III glioma.
ALOX5‐5‐HETE promotes gastric cancer growth and alleviates chemotherapy toxicity via MEK/ERK activation
Authors: Tang Jianjun , Zhang Chuang , Lin Jingjing , Duan Peng , Long Jian , Zhu Hongyan 
Published: June 2021

AbstractBackgroundRecent studies highlight the regulatory role of arachidonate lipoxygenase5 (Alox5) and its metabolite 5‐hydroxyeicosatetraenoic acid (5‐HETE) in cancer tumorigenesis and progression. In this study, we analyzed the expression, biological function and the downstream signaling of Alox5 in gastric cancer.MethodsAlox5 protein levels were measured using IHC and ELISA. Growth, migration and survival assays were performed. Phosphorylation of molecules involved in growth and survival signaling were analyzed by WB. Analysis of variance and t‐test were used for statistic analysis.ResultsAlox5 and 5‐HETE levels were upregulated in gastric cancer patients. ALOX5 overexpression or 5‐HETE addition activates gastric cancer cells and reduces chemotherapy’s efficacy. In contrast, ALOX5 inhibition via genetic and pharmacological approaches suppresses gastric cancer cells and enhances chemotherapy’s efficacy. In addition, Alox5 inhibition led to suppression of ERK‐mediated signaling pathways whereas ALOX5‐5‐HETE activates ERK‐mediated signaling in gastric cancer cells.ConclusionsOur work demonstrates the critical role of ALOX5‐5‐HETE in gastric cancer and provides pre‐clinical evidence to initialize clinical trial using zileuton in combination with chemotherapy for treating gastric cancer.
Rapid Multialkylation of Aqueous Ammonia with Alcohols by Heterogeneous Iridium Catalyst under Simple Conditions
Authors: Yu Han , Ma Lin , Wada Kenji , Kurihara Ryohsuke , Feng Qi , Uemura Shinobu , Isoda Kyosuke 
Published: June 2021

AbstractThis paper reports the synthesis of tertiary and secondary amines from aqueous ammonia and benzylic alcohols by titania‐supported iridium catalyst. It is a successful example of heterogeneous systems at moderate temperature without either additional solvent or high pressure. The catalytic system showed good tolerance to the atmosphere condition and performed rapidly to give tribenzylamine a yield of over 99 % within 6 hours in argon. The crystal structure of titania supports for iridium catalysts strongly affected their activity. The catalysis smoothly proceeded on larger scales. The catalyst could be easily reused and run at least for 5 cycles without significant loss of activity. The highly‐dispersed iridium species of less than 2 nm in diameter would be responsible for the excellent catalytic activity. This catalyst is well applicable in multialkylation of aqueous ammonia with various primary and secondary benzylic alcohols.
Modeling and Simulation of Hydrodynamics and Filtration in a Membrane‐Assisted Stirred Slurry Reactor
Authors: Qiu Meizhong , Liu Yefei , Xu Lei , Wang Cong , Jiang Hong , Chen Rizhi 
Published: June 2021

AbstractA membrane‐assisted stirred slurry reactor is developed by equipping a membrane tube into a stirred tank. Liquid‐solid flow is simulated by the Euler‐Lagrange method with filtration and particle deposition models. Acceptable predictions on the cake mass and particle deposition patterns are achieved by comparing with experimental data. The introduction of the membrane tube generates an asymmetric flow field. Shear stress on the membrane surface has a direct influence on the particle deposition. Increasing the impeller rotating speed leads to larger shear stress and mitigates the particle deposition. The cake mass is reduced by placing the membrane tube close to the impeller. The upward liquid flow pumped by the pitched‐blade impeller results in low shear stress and the vertical‐blade impeller is preferable.
Preparation of Three‐Dimensional Copper‐Zinc Alloy Current Collector by Powder Metallurgy for Lithium Metal Battery Anode
Authors: Qiang Zhe , Liu Bao , Yang Bingjun , Ma Pengjun , Yan Xingbin , Wang Bixia 
Published: June 2021

AbstractLithium metal batteries (LMB) have been considered as the most promising energy storage devices for electric vehicles and portable electronic devices, however their applications are usually limited due to the poor cycle stability and serious safety problems of the battery, which were caused by uncontrolled growth of lithium dendrite and unlimited volume change of anode during Li plating/stripping. Herein, we design a three‐dimensional porous copper‐zinc alloy (3D Cu−Zn) by powder metallurgy method, which has suitable and controllable porous structure for lithium deposition in lithium metal battery. By systematically tailoring particle size of metal powder and other parameters, the 3D Cu−Zn was prepared, which can be used as current collector of lithium anode and shows good cyclic stability. The Li metal anode with 3D Cu−Zn porous current collector can stably cycle for as long as 800 h under a high Li plating/stripping capacity of 1 mA h cm−2 and high current density of 1 mA cm−2. Li@3D Cu−Zn||LiFePO4 cell has excellent rate performance and cycle performance. This work may open a new avenue for building better lithium metal battery with long cycle performance.