bluuebunny/crossref_metadata_2025_split huggingface dataset:
Symmetrically Tetra‐functionalized Pillar[6]arenes Prepared by Fragment Coupling
Authors: Zeng Hong , Liu Peiren , Xing Hao , Huang Feihe 
Published: December 2021

AbstractDue to the highly symmetrical structures generated from one‐pot syntheses, the partial functionalization of macrocycles is usually beset with low yields and onerous purifications of the target multifunctional macrocycles. To improve this situation, taking pillar[6]arenes as an example, a two‐step fragment coupling method has been developed for synthesizing symmetrically tetra‐functionalized pillar[6]arenes, namely X‐pillar[6]arenes. This method is simple and versatile, which makes hetero‐fragment coupling and pre‐functionalization available. Nine new macrocycles and a pillar[6]arene‐based cage have been prepared. In addition, one of the newly synthesized macrocycles,COOEtEtXP[6], exhibits a strong cyan luminescence in the solid state under irradiation by 365 nm UV light. This emission originates from intramolecular through‐space conjugation. Meanwhile, formation of a supramolecular polymer by multiple non‐covalent intra/intermolecular interactions helps rigidify the structure and makeCOOEtEtXP[6]an efficient solid‐state emitter. It is believed that this fragment coupling can also be used to realize the multi‐functionalization of other macrocycles.
One‐Step Access to Heteroatom‐Functionalized Imidazol(in)ium Salts
Authors: Pasyukov Dmitry V. , Shevchenko Maxim A. , Shepelenko Konstantin E. , Khazipov Oleg V. , Burykina Julia V. , Gordeev Evgeniy G. , Minyaev Mikhail E. , Chernyshev Victor M. , Ananikov Valentine P. 
Published: December 2021

AbstractImidazolium salts have ubiquitous applications in energy research, catalysis, materials and medicinal sciences. Here, we report a new strategy for the synthesis of diverse heteroatom‐functionalized imidazolium and imidazolinium salts from easily available 1,4‐diaza‐1,3‐butadienes in one step. The strategy relies on a discovered family of unprecedented nucleophilic addition/cyclization reactions with trialkyl orthoformates and heteroatomic nucleophiles. To probe general areas of application, synthesized N‐heterocyclic carbene (NHC) precursors were feasible for direct metallation to give functionalized M/carbene complexes (M=Pd, Ni, Cu, Ag, Au), which were isolated in individual form. The utility of the chloromethyl function for the postmodification of the synthesized salts and Pd/carbene complexes was demonstrated. The obtained complexes and imidazolium salts demonstrated good activities in Pd‐ or Ni‐catalyzed model cross‐coupling and C−H activation reactions.
Diskrete gestapelte Dimere von aromatischen Oligoamid‐Helices
Authors: Bindl Daniel , Mandal Pradeep K. , Allmendinger Lars , Huc Ivan 
Published: December 2021

AbstractEine starke Bindung wurde zwischen den C‐terminalen Querschnitten von aromatischen Oligoamid‐Helices in wässriger Lösung beobachtet. Diese führt zur Bildung von diskreten Kopf‐an‐Kopf‐Dimeren, die im langsamen Austausch mit den entsprechenden Monomeren auf der NMR‐Zeitskala stehen. Die Art und Struktur der Dimere wurde durch 2D‐NOESY‐ und DOSY‐Spektroskopie, Massenspektrometrie und Röntgenkristallographie nachgewiesen. An der Bindungsschnittstelle beteiligt sind eine große hydrophobe aromatische Oberfläche und Wasserstoffbrückenbindungen. Die Dimerisierung setzt voraus, dass die Helices die gleiche Händigkeit aufweisen und eine C‐terminale Carboxyfunktion vorhanden ist. Der Protonierungszustand der Carboxygruppe spielt eine entscheidende Rolle und führt zu einer pH‐Abhängigkeit der Assoziation. Die Dimerisierung wird auch durch benachbarte Seitenketten beeinflusst und kann programmiert werden, um selektiv heteromere Aggregate zu bilden.
Selective Fluoromethyl Couplings of Alkynes via Nickel Catalysis
Authors: Li Huan , Wang Fang , Zhu Shengqing , Chu Lingling 
Published: December 2021

AbstractWe describe here a Ni‐catalyzed intermolecular carbo‐fluoromethylation of alkynes with aliphatic halides and fluoromethyl halides (BrCF2H and ICH2F) in the presence of zinc, enabling the facile and selective access to a diverse range of biologically valuable CF2H/CH2F‐incorporated alkenes with excellent regio‐ and stereoselectivity. Notably, merging intramolecular radical cyclization with fluoromethyl coupling enables the expedient constructions of CF2H/CH2F‐incorporated lactones and lactams with high efficiency and selectivity. Mechanistic studies disclose that this catalytic protocol proceeds via a radical addition to an alkyne followed by selective coupling with the fluoromethyl unit.
Assembling Metal Organic Layer Composites for High‐Performance Electrocatalytic CO2 Reduction to Formate
Authors: Liu Hang , Wang Hongguang , Song Qian , Küster Kathrin , Starke Ulrich , van Aken Peter A. , Klemm Elias 
Published: December 2021

Abstract2D metal–organic‐framework (MOF) based composites have emerged as promising candidates for electrocatalysis due to their high structural flexibility and fully exposed active sites. Herein, a freestanding metal–organic layer (MOL) with a 2D kgd (kagome dual) lattice was constructed with abundant surface oxygenate groups serving as anchoring sites to immobilize diverse guests. Taking Bi as an example, tetragonal Bi2O3 nanowires can be uniformly grown on MOLs after solvothermal treatment, the structural evolution of which was followed by ex situ electron microscopy. The as‐prepared Bi2O3/MOL exhibits excellent CO2 electroreduction activity towards formate reaching a specific current of 2.3 A mgBi−1 and Faradaic efficiencies of over 85 % with a wide potential range from −0.87 to −1.17 V, far surpassing Bi2O3/UiO (a 3D Zr6‐oxo based MOF) and Bi2O3/AB (Acetylene Black). Such a post‐synthetic modification strategy can be flexibly extended to develop versatile MOL composites, highlighting the superiority of optimizing MOL‐based composites for electrocatalysis.
Acceleration of FeIII/FeII cycle enhanced by Pd/MOF‐808(Zr) composite in hydrogen promotion Fenton system for sulfamethazine elimination
Authors: Qiu Wen‐Jing , Gao Ming‐Wu , Chen Qi , Zheng Ao , Shi Yi‐Jia , Liu Xin , Li Juan‐Hong , Dai Guo‐Liang , Hu Yang , Lin Zi‐Xia 
Published: December 2021

AbstractUnder normal temperature and pressure, a novel improved Fenton system that was named MHACF‐MOF‐808(Zr) was constructed after the introduction of Pd/MOF‐808(Zr) and H2 to solve the inherent problem of the production of iron sludge in the classic Fenton system. Only trace amount of FeII was required during the whole reaction because FeIII could be rapidly reduced by the active hydrogen derived from the adsorption and activation of H2 on the surface of Pd/MOF‐808(Zr) composite. The concentration of FeII could be maintained more than 10 μM. The removal of target pollutant sulfamethazine in this system was mainly relied on the degradation of ·OH verified by both of the direct detection and indirect inhibition (using methanol). By using the calculation of Laplacian bond order, the degradation pathway of sulfamethazine followed by the cleavage of NS bond. This prediction was verified by the detection of intermediate products. Only 21% sulfamethazine could be degraded after 3‐h reaction in the classic Fenton reaction system, while it could be thoroughly degraded in 1.5 h in the MHACF‐MOF‐808(Zr) system. The influence of main parameters on the degradation effect of sulfamethazine, such as initial pH, the flow of H2, dosage of Pd/MOF‐808(Zr), concentration of sulfamethazine, ferrous, and hydrogen peroxide, were systematically studied. Based on the relative stability of Pd/MOF‐808(Zr) confirmed by the morphological characterization, sulfamethazine could be efficiently degraded in the MHACF‐MOF‐808(Zr) system.
B Cell Numbers Predict Humoral and Cellular Response Upon SARS–CoV‐2 Vaccination Among Patients Treated With Rituximab
Authors: Stefanski Ana‐Luisa , Rincon‐Arevalo Hector , Schrezenmeier Eva , Karberg Kirsten , Szelinski Franziska , Ritter Jacob , Jahrsdörfer Bernd , Schrezenmeier Hubert , Ludwig Carolin , Sattler Arne , Kotsch Katja , Chen Yidan , Claußnitzer Anne , Haibel Hildrun , Proft Fabian , Guerra Gabriela , Durek Pawel , Heinrich Frederik , Ferreira‐Gomes Marta , Burmester Gerd R. , Radbruch Andreas , Mashreghi Mir‐Farzin , Lino Andreia C. , Dörner Thomas 
Published: December 2021

ObjectivePatients with autoimmune inflammatory rheumatic diseases receiving rituximab (RTX) therapy are at higher risk of poor COVID‐19 outcomes and show substantially impaired humoral immune response to anti–SARS–CoV‐2 vaccine. However, the complex relationship between antigen‐specific B cells and T cells and the level of B cell repopulation necessary to achieve anti‐vaccine responses remain largely unknown.MethodsAntibody responses to SARS–CoV‐2 vaccines and induction of antigen‐specific B and CD4/CD8 T cell subsets were studied in 19 patients with rheumatoid arthritis (RA) or antineutrophil cytoplasmic antibody–associated vasculitis receiving RTX, 12 patients with RA receiving other therapies, and 30 healthy controls after SARS–CoV‐2 vaccination with either messenger RNA or vector‐based vaccines.ResultsA minimum of 10 B cells per microliter (0.4% of lymphocytes) in the peripheral circulation appeared to be required for RTX‐treated patients to mount seroconversion to anti‐S1 IgG upon SARS–CoV‐2 vaccination. RTX‐treated patients who lacked IgG seroconversion showed reduced receptor‐binding domain–positive B cells (P = 0.0005), a lower frequency of Tfh‐like cells (P = 0.0481), as well as fewer activated CD4 (P = 0.0036) and CD8 T cells (P = 0.0308) compared to RTX‐treated patients who achieved IgG seroconversion. Functionally relevant B cell depletion resulted in impaired interferon‐γ secretion by spike‐specific CD4 T cells (P = 0.0112, r = 0.5342). In contrast, antigen‐specific CD8 T cells were reduced in both RA patients and RTX‐treated patients, independently of IgG formation.ConclusionIn RTX‐treated patients, a minimum of 10 B cells per microliter in the peripheral circulation is a candidate biomarker for a high likelihood of an appropriate cellular and humoral response after SARS–CoV‐2 vaccination. Mechanistically, the data emphasize the crucial role of costimulatory B cell functions for the proper induction of CD4 responses propagating vaccine‐specific B cell and plasma cell differentiation.
A Two‐Photon Ratiometric Sensing Platform Based on Solid‐State Luminescent Benzocoumarin: Application to Prolonged Bioimaging of Hydrogen Peroxide
Authors: Rim Kim Hye , Sarkar Sourav , Han Ahn Kyo 
Published: December 2021

AbstractFluorescent probes provide essential tools for studying biological systems. For the prolonged imaging of cellular analytes, the fast clearance of small‐molecular probes and products is a matter of concern in the quantitative analysis. Activatable probes that produce insoluble products inside cells can be used for prolonged imaging, but those with ratiometric imaging capability are rare. We disclose a novel sensing platform that is capable of prolonged imaging, in addition to ratiometric signaling for reliable quantitative analysis. Specifically, 3‐(pyridin‐4‐yl)‐8‐(pyrrolidin‐1‐yl)‐2H‐benzo[g]chromen‐2‐one and its pyridinium salt as a product/probe couple constitute the ratiometric sensing platform. As the former dye produces highly emissive insoluble nanoaggregates inside cells, a fluorescent probe in the latter form enables prolonged imaging of the target analyte in cells as well as in tissue by two‐photon microscopy.
Determination of supermassive black hole spins in local active galactic nuclei
Authors: Piotrovich Mikhail Yu. , Buliga Stanislava D. , Natsvlishvili Tinatin M. 
Published: December 2021

AbstractWe estimated the radiative efficiency and spin value for a number of local active galactic nuclei (AGNs) with using three popular models connecting the radiative efficiency with such parameters of AGNs as mass of supermassive black hole (SMBH), angle between the line of sight and the axis of the accretion disk and bolometric luminosity. Analysis of the obtained data shows that the spin value decreases with cosmic time, which is in agreement with results of theoretical calculations for low‐redshift AGNs of other authors. Also, we found that the spin value increases with the increasing mass of SMBH and bolometric luminosity. This is the expected result that corresponds to theoretical calculations. Analysis of the distribution of the spin values shows a pronounced peak in the distribution in range. ∼40% of objects have spin and ∼50% of objects have spin . These results are in good agreement with our previous results and with the results of other authors.
Effective immobilization of lactate dehydrogenase onto mesoporous silica
Authors: Alagöz Dilek , Toprak Ali , Varan Nazlı Ece , Yildirim Deniz , Tükel S. Seyhan 
Published: December 2021

AbstractThis study presents that covalent immobilization technique has been utilized for the immobilization of l‐lactate dehydrogenase (l‐LDH) from porcine on mesoporous silica. To develop mesoporous silica as support material for use in l‐LDH immobilization, the particle surfaces were functionalized with 3‐aminopropyltrimethoxysilane and further conjugated with glutaraldehyde. The effect of some parameters such as glutaraldehyde concentration, immobilization pH, initial enzyme concentration, and immobilization time was investigated and the optimum conditions for these parameters were determined as 1% (w/v), pH 8.0, 1 mg/ml, and 120 min, respectively. The maximum working pH and temperature for the oxidation of lactate to pyruvate reaction were determined as 10.0 and 35°C for free and 9.0 and 40°C for immobilized l‐LDH, respectively. The kinetic parameters (Km and Vmax) of l‐LDH for the oxidation of lactate to pyruvate reaction were examined as 1.02 mM and 7.58 U/mg protein for free and 0.635 mM and 1.7 U/mg protein for immobilized l‐LDH, respectively. Moreover, the immobilized l‐LDH was 1.3‐fold more stable than free l‐LDH at 25°C according to calculated t1/2 values. The immobilized l‐LDH retained 80% of its initial activity in a batch reactor after 14 reuses.
Small molecule epigenetic modulators for enhancing recombinant antibody production in CHO cell cultures
Authors: Kim Dongil , Yoon Chansik , Lee Gyun Min 
Published: December 2021

AbstractSmall molecule epigenetic modulators that modify epigenetic states in cells are useful tools for regulating gene expression by inducing chromatin remodeling. To identify small molecule epigenetic modulators that enhance recombinant protein expression in Chinese hamster ovary (CHO) cells, we examined eight histone deacetylase inhibitors (iHDACs) and six DNA methyltransferase inhibitors as chemical additives in recombinant CHO (rCHO) cell cultures. Among these, a benzamide‐based iHDAC, CI994, was the most effective in increasing monoclonal antibody (mAb) production. Despite suppressing cell growth, the addition of CI994 to mAb‐expressing GSR cell cultures at 10 μM resulted in a 2.3‐fold increase in maximum mAb concentration due to a 3.0‐fold increase in specific mAb productivity (qmAb). CI994 increased mAb messenger RNA levels and histone H3 acetylation in GSR cells, and chromatin immunoprecipitation‐quantitative polymerase chain reaction analysis revealed that CI994 significantly increased the histone H3 acetylation level at the cytomegalovirus promoter driving mAb gene expression, indicating that chromatin remodeling in the promoter region results in enhanced mAb gene transcription and qmAb. Similar beneficial effects of CI994 on mAb production were observed in mAb‐expressing CS13‐1.00 cells. Collectively, our findings indicate that CI994 increases mAb production in rCHO cell cultures by chromatin remodeling resulting from acetylation of histones in the mAb gene promoter.
Stimulated reversal of the strong adhesion of catechol onto a silica surface
Authors: Ilyas Muhammad , Mian Shabeer Ahmad , Rauf Abdur , Ahmed Ejaz , Rahman Gul , Sannyal Arindam , Jang Joonkyung 
Published: December 2021

AbstractMarine mussels permanently adhere to various surfaces via catechol (1,2‐dihydroxybenzene) functional groups. Such biofouling causes adverse effects, including the corrosion and dragging of a marine vessel. By using the density functional theory, we show an electrical stimulus detach a catechol molecule that strongly adhered to a silica surface. A moderate electric field significantly decreases the binding energy of catechol adhered to a dry or wet silica surface.
Computational study of the pKa values of a modified G·C base pair in duplex DNA
Authors: Kim Hyeonjun , Pak Youngshang 
Published: December 2021

AbstractDuring the demethylation of 5‐methyl cytosine residues in duplex DNAs, formyl or carboxyl cytosines are produced and these modified cytosines are preferentially recognized and excised by the thymine DNA glycosylase (TDG). It has been suggested that the TDG detects a soft spot created by weakening of the hydrogen bond of a G·C base pair (bp). Such bp destabilization is ascribed to the presence of electron‐withdrawing 5‐formyl or 5‐carboxyl group in the modified cytosine. Previously, this bp weakening was linked to reduced values of nucleoside molecules. However, the values of nucleosides can deviate from those of duplex DNAs. Thus, to improve agreement with experiments, the corresponding values for DNA environments are needed. In this computational study, we report two values of the N3‐ and the C5‐carboxyl sites in the 5‐carboxyl cytosine residue in a duplex DNA that enable more reasonable interpretations of previous experimental data.
The efficacy and safety of pyrotinib in treating HER2‐positive breast cancer patients with brain metastasis: A multicenter study
Authors: Gao Min , Fu Chao , Li Shanshan , Chen Fang , Yang Yongteng , Wang Chunjian , Qin Jie , Liu Shuaishuai , Zhang Ranran , Wang Changyuan , Zong Jinbao , Meng liping , Meng Xiangjiao 
Published: December 2021

AbstractPurposeTo investigate the efficacy and safety of pyrotinib in treating patients with human epidermal growth factor receptor type 2 (HER2)‐positive breast cancers with brain metastasis.Patients and MethodsThis is a multicenter retrospective study, and the HER2‐positive breast cancer patients with brain metastasis were studied. The enrolled patients were given pyrotinib 400 mg orally once per day for 21 days as one cycle, and evaluated every two cycles. All relevant data were detected for final assessments including medical history, clinical examination, histopathology, immunohistochemistry, radiographic imaging, treatment outcome, and adverse events.ResultsForty‐two female patients in total were enrolled in this study. The objective response rate (ORR) and disease control rate (DCR) of central nervous system (CNS), were found in 20 of 42 (47.6%) and in 39 of 42 (92.8%), respectively, while for extra‐CNS, the respective ORR and DCR were in 9 of 38 (23.6%) and in 36 of 38 (94.7%), respectively. The compounded ORR and DCR were seen in 17 of 42 (40.4%) and in 39 of 42 (92.8%), respectively. The improvement rate of craniocerebral symptoms after treatment was (19/19) 100% and the median duration was 15 months. The median effective time of brain metastases and other metastases was 43 and 50 days. The median follow‐up time was 22 months (interquartile range, 16.0–24.3 months). The median time for progression in brain metastasis was 16.6 months. The median time to progress for our group patients was 11.1 months. Sixteen patients (36%) with adverse reactions were recorded in the study.ConclusionPyrotinib combined with chemotherapy/radiotherapy or alone showed significantly greater local control rates and progression free survival (PFS), with manageable toxicity for patients with HER2‐positive breast cancer with brain metastases, and further follow‐up will provide an overall survival (OS) data.
Potential Mechanisms of Methylglyoxal‐Induced Human Embryonic Kidney Cells Damage: Regulation of Oxidative Stress, DNA Damage, and Apoptosis
Authors: Liu Dan , Cheng Ye , Tang Zhipeng , Chen Junliang , Xia Ying , Xu Chengbin , Cao Xiangyu 
Published: December 2021

AbstractMethylglyoxal (MGO) is a reactive carbonyl species that can cause cellular damage and is closely related to kidney disease, especially diabetic nephropathy. The toxic effect of MGO (0.5, 1, and 2 mM) on human embryonic kidney (HEK293) cells and its underlying mechanisms were explored in this study. Cell viability, apoptosis and the signaling pathways were measured with MTT, fluorescent staining and western blot experiments, the results showed that MGO could induce oxidative stress and cell inflammation, the level of reactive oxygen species (ROS) increased, and p38MAPK, JNK and NF‐κB signaling pathways were activated. Meanwhile, MGO also induced DNA damage. The expression of DNA oxidative damage marker 8‐hydroxy‐2’‐deoxyguanosine (8‐OHdG) increased, the expression of double‐strand break marker γH2AX increased significantly, and ATM/Chk2/p53 DNA damage response signaling pathway was activated. Furthermore, the expression of the receptor for advanced glycation end products (RAGE) also increased. Finally, mitochondrial membrane potential (MMP) decreased, fluorescence intensity of Hoechst33258 increased, and the protein expression ratio of Bax/Bcl‐2 increased significantly after the treatment of MGO. These results demonstrated that MGO might induce HEK293 cells damage by regulating oxidative stress, inflammation, DNA damage, and cell apoptosis, which revealed the specific mechanisms of MGO‐induced damage to HEK293 cells.
Dose‐Dependent Effect of Wedelia trilobata Essential Oil (EO) on Lettuce (Lactuca sativa L.) with Multivariate Analysis
Authors: Azlan Azizan Kamalrul , Izzairy Zamani Arief , Azlan Nor Muhammad Nor , Khairudin Khairunisa , Yusoff Nornasuha , Firdaus Nawawi Mohamad 
Published: December 2021

AbstractUnderstanding metabolite changes and underlying metabolic pathways that may be affected in target plants following essential oils (EOs) exposure is of great importance. In this study, a gas chromatography‐mass spectrometry (GC/MS) based metabolomics approach was used to determine the metabolite changes in lettuce (Lactuca sativa L.) shoot and root after exposure to different concentrations of W. trilobata EO. Multivariate analyses of principal component analysis (PCA) and orthogonal partial least‐discriminant analysis (OPLS‐DA) corroborated that shoot and root of lettuce responded differently to W. trilobata EO. In EO‐exposed shoot samples, an increase in the levels of malic acid, glutamine, serine, lactose and α‐glucopyranose affected important metabolism pathways such as glycolysis, fructose and mannose metabolism and galactose metabolism. The findings suggest that lettuce may be up‐regulating these metabolites to increase tolerance against W. trilobata EO. In EO‐exposed root samples, changes in fatty acid biosynthesis, elongation, degradation, phenylalanine, tyrosine and tryptophan metabolism were linked to a decrease in lyxose, palmitic acid, octadecanoic acid, aspartic acid, phenylalanine and myo‐inositol. These results indicate that W. trilobata EO could cause alterations in fatty acid compositions and lead to inhibition of roots growth. Together, these findings provide insight into the metabolic responses of lettuce upon W. trilobata EO exposure, as well as potential mechanisms of action of W. trilobata EO as bio‐herbicides.