bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interactions Between Two Cobalt Salen Centers Bridged by Non‐Conjugated Linkers**
Authors: Speiser Bernd , Zitzer Georg 
Published: June 2021

AbstractTetra‐tert‐butyl‐Co(salen), an amido‐substituted derivative and a series of bis(salen) complexes of cobalt(II) with the two metal centers bridged by flexible, non‐conjugated bis‐amido linkers are investigated by cyclic voltammetry, chronoamperometry, and differential pulse voltammetry in four electrolytes (acetonitrile or dichloromethane, conventional or weakly coordinating anion). Cyclic voltammograms are analyzed by simulation based on E or EE mechanisms. The compounds are characterized by formal potentials
, diffusion coefficients D and number of electrons transferred, n. Differences in the
values for the subsequent two one‐electron transfer steps are used as indicators for the interaction between the metal centers in the bis(salen) complexes. The effects of solvent and supporting electrolyte are consistent with the assumption of electrostatic through‐space interactions and coordination to the Co centers. In the dinuclear complexes step‐wise electron transfers according to normal potential ordering makes these compounds “pretenders” in Winter's terms (R.F. Winter, Organometallics 2014, 33, 4517–4536).
Application of the Redox‐Transmetalation Procedure to Access Divalent Lanthanide and Alkaline‐Earth NHC Complexes**
Authors: Schwarz Noah , Sun Xiaofei , Yadav Ravi , Köppe Ralf , Simler Thomas , Roesky Peter W. 
Published: June 2021

AbstractDivalent lanthanide and alkaline‐earth complexes supported by N‐heterocyclic carbene (NHC) ligands have been accessed by redox‐transmetalation between air‐stable NHC‐AgI complexes and the corresponding metals. By using the small ligand 1,3‐dimethylimidazol‐2‐ylidene (IMe), two series of isostructural complexes were obtained: the tetra‐NHC complexes [LnI2(IMe)4] (Ln=Eu and Sm) and the bis‐NHC complexes [MI2(IMe)2(THF)2] (M=Yb, Ca and Sr). In the former, distortions in the NHC coordination were found to originate from intermolecular repulsions in the solid state. Application of the redox‐transmetalation strategy with the bulkier 1,3‐dimesitylimidazol‐2‐ylidene (IMes) ligand yielded [SrI2(IMes)(THF)3], while using a similar procedure with Ca metal led to [CaI2(THF)4] and uncoordinated IMes. DFT calculations were performed to rationalise the selective formation of the bis‐NHC adduct in [SrI2(IMe)2(THF)2] and the tetra‐NHC adduct in [SmI2(IMe)4]. Since the results in the gas phase point towards preferential formation of the tetra‐NHC complexes for both metal centres, the differences between both arrangements are a result of solid‐state effects such as slightly different packing forces.
Bulky Barbiturates as Non‐Toxic Ionic Dye Insulators for Enhanced Emission in Polymeric Nanoparticles
Authors: Andreiuk Bohdan , Aparin Ilya O. , Reisch Andreas , Klymchenko Andrey S. 
Published: June 2021

AbstractBulky hydrophobic counterions (weakly coordinating anions) can insulate ionic dyes against aggregation‐caused quenching (ACQ) and enable preparation of highly fluorescent dye‐loaded nanoparticles (NPs) for bioimaging, biosensing and light harvesting. Here, we introduce a family of hydrophobic anions based on fluorinated C‐acyl barbiturates with delocalized negative charge and bulky non‐polar groups. Similarly to fluorinated tetraphenylborates, these barbiturates prevent ACQ of cationic dye alkyl rhodamine B inside polymer NPs made of biodegradable poly(lactic‐co‐glycolic acid) (PLGA). Their efficiency to prevent ACQ increases for analogues with higher acidity and bulkiness. Their structure controls dye‐dye communication, yielding bright NPs with on/off switching or stable emission. They enhance dye encapsulation inside NPs, allowing intracellular imaging without dye leakage. Compared to fluorinated tetraphenylborates known as cytotoxic transmembrane ion transporters, the barbiturates display a significantly lower cytotoxicity. These chemically available and versatile barbiturate derivatives are promising counterion scaffolds for preparation of bright non‐toxic fluorescent nanomaterials.
Chirality in polythiophenes: A review
Authors: Wang Kun , Xiao Yin 
Published: June 2021

AbstractChiroptical polythiophene (PTh), as one of the most important chiral conductive polymers, is an emerging and hot topic in chiral materials, which shows great application potentials in fields as diverse as chiral sensing and separation, asymmetry catalysis, chiroptoelectronics, and even chiro‐spintronics. This review summarizes progress in chiral polythiophenes (PThs) in the past 10 years, including the synthesis, properties and applications. Main focus is placed on the manner in which chirality is implemented and the optical activity of the chiral PThs. We showcase examples in which the chirality of PThs is induced by side chain substituents with point, planar, and axial chirality or arises from external chiral media. Application of chiral PThs is also included. Finally, perspectives for further development are offered.
Management of serious complications in intra‐abdominal desmoid‐type fibromatosis
Authors: Bini Federica , Fiore Marco , Provenzano Salvatore , Bertulli Rossella , Ottini Arianna , Colombo Chiara , Vitellaro Marco , Greco Gabriella , Morosi Carlo , Gronchi Alessandro , Casali Paolo Giovanni , Palassini Elena 
Published: June 2021

AbstractBackgroundDesmoid fibromatosis (DF) is a rare and locally infiltrative monoclonal fibroblastic proliferation arising from connective tissues, with lack of metastatic potential. About 10% of all DF cases are intra‐abdominally sited. Complications in this site, due to the locally infiltrative nature of the disease, may be severe and potentially life threatening. However, data on incidence, management, and outcome of these complications are limited.AimData of patients with sporadic or FAP‐related intra‐abdominal DF treated at Istituto Nazionale dei Tumori (INT) in Milano from 2005 to 2020 who developed a serious complication during the course of their disease were retrospectively collected and analyzed with a descriptive statistics.Methods and ResultsOut of 72 intra‐abdominal DF, 8 cases were identified (M/F: 5/3, median age: 35 years, FAP‐related/sporadic: 2/6): 3 with bowel obstruction, 5 with bowel perforation. In 4 cases the serious complication was the first evidence of disease; in the other 4 cases it occurred at a time interval from diagnosis in the range of 4–44 months (during an active surveillance program in one case and during chemotherapy in the other 3 cases). A surgical treatment was feasible and successful in 5 cases. In 3 surgically unmanageable patients, all progressing and experiencing acute complications while on chemotherapy, a non‐surgical approach with intensive supportive treatment and with a prompt change of chemotherapy regimen was implemented, being successful in two, the other patient dying due to a concomitant progressive lymphoma thereafter.ConclusionIn this series of intra‐abdominal DF, the incidence of serious complications was 11%. Most patients were successfully treated with surgery. When surgery was deemed to be unfeasible, a conservative management with intensive supportive care and a careful choice of chemotherapy was adopted, ensuring a favorable outcome in most.
Selenophene‐Based Hole‐Transporting Materials for Perovskite Solar Cells
Authors: Illicachi Luis A. , Urieta‐Mora Javier , Momblona Cristina , Molina‐Ontoria Agustín , Calbo Joaquín , Aragó Juan , Insuasty Braulio , Ortiz Alejandro , Ortí Enrique , Martín Nazario , Nazeeruddin Mohammad Khaja 
Published: June 2021

AbstractTwo novel and simple donor‐π‐bridge‐donor (D‐π‐D) hole‐transporting materials (HTMs) containing two units of the p‐methoxytriphenylamine (TPA) electron donor group covalently bridged by means of the 3,4‐dimethoxyselenophene spacer through single and triple bonds are reported. The optoelectronic and thermal properties of the new selenium‐containing HTMs have been determined using standard experimental techniques and theoretical density functional theory (DFT) calculations. The selenium‐based HTMs have been incorporated in mesoporous perovskite solar cells (PSCs) in combination with the triple‐cation perovskite [(FAPbI3)0.87(MAPbBr3)0.13]0.92 [CsPbI3]0.08. Limited values of power conversion efficiencies, up to 13.4 %, in comparison with the archetype spiro‐OMeTAD (17.8 %), were obtained. The reduced efficiencies showed by the new HTMs are attributed to their poor film‐forming ability, which constrains their photovoltaic performance due to the appearance of structural defects (pinholes).
Enhanced Detection of Short‐Chain Fatty Acids Using Gas Chromatography Mass Spectrometry
Authors: Gu Haiwei , Jasbi Paniz , Patterson Jeffrey , Jin Yan 
Published: June 2021

AbstractShort‐chain fatty acids (SCFAs) are produced mainly by intestinal microbiota and play an important role in many host biological processes such as immune system development, glucose and energy homeostasis, and regulation of immune response and inflammation. In addition, they participate in the regulation of anorectic hormones, which have a role in appetite control, tumor suppression, and regulating the central and peripheral nervous systems. As such, there is great interest in monitoring levels of SCFAs in various biological samples. Due to the highly hydrophilic and volatile characteristics of SCFAs, optimizing extraction and sample preparation procedures is often a central component to further improve SCFA quantification. Here, we describe a rapid and highly sensitive analytical method for measuring SCFAs in human serum and feces. Briefly, SCFAs are protected by adding sodium hydroxide, followed by a one‐step extraction (pH > 7). Then, SCFAs are quantified by gas chromatography coupled to mass spectrometry (GC‐MS) after derivatization with N‐tert‐butyldimethylsilyl‐N‐methyltrifluoroacetamide (MTBSTFA). This method demonstrates excellent sensitivity, linearity, and derivatization efficiency for simultaneous determination of 14 different SCFAs. Further, this validated method can be successfully applied to quantify SCFAs in micro‐scale biological samples. In summary, we describe efficient and advanced sample preparation and detection procedures that are critically needed for monitoring SCFA concentrations in human biological samples. © 2021 Wiley Periodicals LLC.Basic Protocol: SCFA extraction and detection from fecal and serum samples with gas chromatography−mass spectrometry
CAGE‐prox: A Unified Approach for Time‐Resolved Protein Activation in Living Systems
Authors: Wang Jie , Liu Yuan , Liu Yanjun , Wang Chu , Chen Peng R. 
Published: June 2021

AbstractTemporal activation of proteins of interest (POIs) offers a gain‐of‐function approach to investigate protein functions in dynamic biological processes. Fusion of photo/chemical‐switchable proteins to a POI, or site‐specific blockage/decaging of catalytic residue(s) on a POI, are the most widely utilized strategies for selective protein activation. These methods, however, either lack generality (e.g., active site decaging) or would modify the POI with a bulky tag (e.g., genetic fusion). Recently, a computationally aided and genetically encoded proximal decaging strategy (CAGE‐prox) has been developed for time‐resolved photoactivation of a broad range of proteins in living systems. In contrast to the direct decaging of the active site of a POI, CAGE‐prox relies on a unified caged amino acid that can be anchored in proximity to a protein's functional site for temporal blockage of its activity until rescued by photo/chemical decaging. In order to identify the optimal site for photo‐caged unnatural amino acid insertion, which is key for the effective blockade and re‐activation of the POI, a computational algorithm was developed to screen all possible positions in close proximity to the functional site that would enable turning off/on protein activity via caging/decaging operations. Here, we describe the CAGE‐prox strategy, from in silico design to experimental validation, and provide various examples of its application. © 2021 Wiley Periodicals LLCBasic Protocol 1: In silico design and experimental validation of CAGE‐proxBasic Protocol 2: Orthogonal activation of a POI by CAGE‐prox while minimizing the activity from the endogenous proteinBasic Protocol 3: CAGE‐prox‐enabled, time‐resolved proteomics for the identification of substrates of a proteolytic enzymeBasic Protocol 4: Controlled activation of protein‐based prodrugs for tumor therapy
The recent development of thymol derivative as a promising pharmacological scaffold
Authors: Sahoo Chita Ranjan , Paidesetty Sudhir Kumar , Padhy Rabindra Nath 
Published: June 2021

AbstractThymol (a phenol ring bearing active phytoconstituent) is a privileged scaffold, which is diversified in natural sources. This scaffold acts as an obligatory template for scheming and arriving at designing some newer drug‐molecules with potential biological activities. In the pharmacological perspective, the promising active sites of the scaffold are the positions C‐1, C‐4, and C‐6 of thymol that would be accountable for developing potent drug candidates. This review aims to explore the various synthetic routes and the structural‐activity relationship of thymol scaffold with suitable active pharmacophore sites.
Are stable isotope ratios suitable for describing niche partitioning and individual specialization?
Authors: Matich Philip , Bizzarro Joseph J. , Shipley Oliver N. 
Published: June 2021

AbstractAs concerns about anthropogenic and natural disturbance grow, understanding animal resource use patterns has been increasingly prioritized to predict how changes in environmental conditions, food web structure, and population dynamics will affect biological resilience. Among the tools used to assess resource use, stable isotope analysis has proliferated in ecological studies, particularly in relation to describing intra‐ and interspecific variation in trophic interactions. Despite a growing need to disseminate scientific information, the inherent limitations of stable isotope ratios and inappropriate synonymizing of distinct evolutionary and ecological processes may mislead ecological inferences in natural systems. This situation necessitates a re‐evaluation of the utility of stable isotope ratios to address certain ecological questions. Here, we assess the efficacy of stable isotope ratios to describe two fundamental ecological processes, niche partitioning and individual specialization. Investigation of these processes has increased substantially in accordance with increased access to stable isotope data. This article discusses the circumstances and approaches that are necessary to evaluate niche partitioning and individual specialization, and outlines key considerations for the associated application of stable isotope ratios.
Multiyear resource enrichment creates persistently higher species diversity in a landscape‐scale field experiment
Authors: Lancaster Jill , Downes Barbara J. 
Published: June 2021

AbstractShort‐term resource enrichment can increase species diversity in communities, but prolonged resource enrichment may result in either a diversity collapse or persistent high species diversity if fluctuation‐dependent mechanisms of species coexistence are triggered. We tested the effects of resource enrichment on stream invertebrates by boosting densities of benthic detritus. In a 22‐km stream length, we used wooden stakes to enhance retention of detritus at 40‐m‐long sites; other sites acted as controls. Detritus and invertebrates were sampled prior to treatment and then 1, 2, and 5 yr later. Previously, we reported that detrital densities, species diversity, and densities increased at enrichment sites after 12 months. Here we report that similar increases occurred 2 and 5 yr after manipulation. Prolonged resource enrichment produced persistently higher species diversity without loss of any taxa from the species pool, despite strong shifts in faunal composition in response to environmental variation, including a 1‐in‐100‐yr flood. Detritus densities set upper limits to the densities of common taxa. Positive relations between invertebrate and detritus densities (density–resource relationships) took a variety of forms and showed that detritus was an essential resource for some taxa and a substitutable resource for others. Species varied in the minimum amount of detritus required for presence at a site, and population densities increased strongly from low densities when detritus was increased. These outcomes suggest that fluctuation‐dependent mechanisms of coexistence enabled new taxa to coexist at manipulation sites, with relative nonlinear averaging of competition and the storage effect most likely to be in play. Two characteristics of the study stream underpin diversity increases with resource enrichment: overall low background densities of detritus and species that are able to disperse successfully from upstream areas where detritus is more abundant. Thus, the effects of resource enrichment are context dependent.
Quantifying the relationship linking the community‐weighted means of plant traits and soil fertility
Authors: Daou Laurent , Garnier Éric , Shipley Bill 
Published: June 2021

AbstractIs it possible to generalize relationships between certain plant traits and soil fertility? In particular, are there quantitative relationships between community‐weighted mean (CWM) trait values of leaf dry‐matter content (LDMC), specific leaf area (SLA), plant height, and Grime’s competitor‐stress tolerator‐ruderal (CSR) strategy scores and the generalized soil fertility, FG (i.e., the capacity of a soil to produce biomass when all nonsoil variables are held constant) that are generalizable across different species assemblages and geographical areas? We assessed FG in 21 sites in southern Quebec and 7 sites in southern France using a previously published method based on structural equation modeling. We then determined the CWM values of LDMC, SLA, plant height, and CSR scores in the 21 Quebec sites to obtain quantitative relationships between FG and these CWM traits. Using these relationships, we independently tested the generality of the trait–fertility relationships using data from French sites. The relationships between FG and the CWM traits were nonlinear, but displayed the expected qualitative trends as reported in the literature. In particular, the S score and CWM LDMC decreased with increasing soil fertility, and the R score and CWM SLA increased. CWM traits were more strongly correlated to measures of FG (r2 up to 0.48) than to measures of other soil characteristics (r2 up to 0.17 for nitrogen flux). Importantly, the independently tested French FG–trait relationships showed no significant deviations from these quantitative relationships. Further investigation is necessary to confirm if the same trend applies to other regions and or ecosystems.
Does pulmonary artery pulsatility index predict mortality in pulmonary arterial hypertension?
Authors: Lim Yinghao , Low Ting‐Ting , Chan Siew Pang , Lin Weiqin , Teo Ting Wei , Jang Jin‐Hao Justin , Kuntjoro Ivandito , Tay Edgar Lik‐Wui , Yip James Wei‐Luen 
Published: June 2021

AbstractAimsPulmonary artery pulsatility index (PAPi), defined as [(pulmonary artery systolic pressure − diastolic pulmonary artery pressure)/mean right atrial pressure], is a novel haemodynamic index that predicts right ventricular failure after myocardial infarction and left ventricular assist device implantation. We analysed if a low PAPi is associated with death in our 14 ‐ ​year pulmonary arterial hypertension (PAH) registry.MethodsConsecutive patients with newly diagnosed PAH and complete haemodynamic data were prospectively enrolled into our standing registry between January 2003 and December 2016. PAPi was calculated from baseline invasive right heart catheterization data. A prognostic cut‐off value was determined with a decision tree. Baseline characteristics of ‘high’ and ‘low’ PAPi groups based on this cut‐off were compared, as well as odds of death and time‐to‐death.ResultsOne hundred and two patients were included. Mean age was 53 years, and 77% were women. Our multi‐ethnic cohort was 64% Chinese, 23% Malay, and 10% Indian. The aetiologies were idiopathic (33%), connective tissue disease (31%), congenital heart disease (24%), and others (12%). The low PAPi group (<5.3) had a greater age (56 years vs. 49 years), lower pulmonary artery systolic pressure (71 mmHg vs. 85 mmHg), and higher mean right atrial pressure (14 mmHg vs. 6 mmHg). Mortality risk was higher in the low PAPi group (adjusted odds ratio: 2.98 and adjusted hazard ratio: 2.23). Mean right atrial pressure was the strongest predictor (hazard ratio 1.114, P = 0.009) when components of PAPi were analysed.ConclusionsPulmonary artery pulsatility index was found to be predictive of mortality in PAH and may be a valuable marker for risk stratification. Its prognostic strength may be driven by mean right atrial pressure.
Telocytes‐derived extracellular vesicles alleviate aortic valve calcification by carrying miR‐30b
Authors: Yang Rong , Tang Yihu , Chen Xiaowen , Yang Yang 
Published: June 2021

AbstractAimsCalcific aortic valve disease (CAVD) is frequent in the elderly. Telocytes (TCs) are implicated in intercellular communication by releasing extracellular vesicles (EVs). This study investigated the role of TC‐EVs in aortic valve calcification.Methods and resultsTCs were obtained and identified using enzymolysis method and flow cytometry. EVs were isolated from TCs using differential high‐speed centrifugation method and identified using transmission electron microscope, western blot, and qNano analysis. The mouse model of CAVD was established. The changes of aortic valve activity‐related indicators were analysed by ultrasound, and the expressions of TC markers CD34 and vimentin in mouse valve tissues were detected using RT‐qPCR and western blot. The model mice were injected with TC‐derived EVs. The expressions of Runx2, osteocalcin, and caspase‐3 were detected using RT‐qPCR and western blot. The calcification model of valvular interstitial cells (VICs) was established. TC‐EVs were co‐cultured with calcified VICs, and calcium deposition was detected using alizarin red S staining. miR‐30b expression in calcified valvular tissues and cells was detected after EV treatment. miR‐30b expression in TCs was knocked down and then EVs were extracted and co‐cultured with calcified VICs. The target of miR‐30b was predicted through bioinformatics website and verified using dual‐luciferase assay. The levels of Wnt/β‐catenin pathway‐related proteins were detected. ApoE−/− mice fed with a high‐fat diet showed decreased aortic valve orifice area, increased aortic transvalvular pressure difference and velocity, reduced left ventricular ejection fraction, decreased CD34 and vimentin, and increased caspase‐3, Runx2, and osteocalcin. The levels of apoptosis‐ and osteogenesis‐ related proteins were inhibited after EV treatment. TC‐EVs reduced calcium deposition and osteogenic proteins in calcified VICs. EVs could be absorbed by VICs. miR‐30b expression was promoted in calcified valvular tissues and cells after EV treatment. Knockdown of miR‐30b weakened the inhibitory effects of TC‐EVs on calcium deposition and osteogenic proteins. miR‐30b targeted Runx2. EV treatment inhibited the Wnt/β‐catenin pathway, and knockdown of miR‐30b in TCs attenuated the inhibitory effect of TC‐EVs on the Wnt/β‐catenin pathway.ConclusionTC‐EVs played a protective role in aortic valve calcification via the miR‐30b/Runx2/Wnt/β‐catenin axis.