bluuebunny/crossref_metadata_2025 huggingface dataset:
Endogenously produced peroxynitrite induces the oxidation of mitochondrial and nuclear proteins in immunostimulated macrophages
Authors: Szabó Csaba , O'Connor Michael , Salzman Andrew L
Published: July 2002

Here we investigated the role of endogenous nitric oxide (NO) and peroxynitrite in the process of protein oxidation (as measured by the detection of 2,4‐dinitrophenylhydrazine‐reactive carbonyls) in immunostimulated macrophages. Immunostimulation of the macrophages by bacterial lipopolysaccharide and gamma‐interferon (LPS/IFNγ) resulted in a marked increase in the oxidation of a large number of mitochondrial and nuclear proteins. The inhibitor of NO synthase, NG‐methyl‐l‐arginine (3 mM), and the cell‐permeable superoxide dismutase mimetic Mn(III)tetrakis(4‐benzoic acid)porphyrin (300 μM) both reduced the extent of protein oxidation in response to LPS/IFNγ. These results support the view that endogenously produced peroxynitrite induces protein oxidation in the mitochondria and nucleus of immunostimulated macrophages.
Lipoxygenase inhibitors block CD95 ligand‐mediated apoptosis of human malignant glioma cells
Authors: Wagenknecht Bettina , Gulbins Erich , Lang Florian , Dichgans Johannes , Weller Michael
Published: July 2002

CD95 ligand is a cytotoxic cytokine that induces apoptosis. Here we report that CD95‐mediated apoptosis of human malignant glioma cells is associated with arachidonic acid (AA) release. Inhibitors of phospholipase A2, phospholipase C or diacylglycerol lipase have minor effects on AA release and fail to modulate apoptosis. Formation of two AA metabolites generated during CD95‐dependent apoptosis is attenuated by the lipoxygenase inhibitor, nordihydroguaretic acid (NDGA). NDGA also blocks CD95 ligand‐induced apoptosis. This effect is independent of antioxidant properties of NDGA. Lipoxygenase may thus play a critical role in CD95 ligand‐induced apoptosis of human malignant glioma cells.
The recognition of haemoglobin by antibodies raised for the immunoassay of β‐amyloid
Authors: Cutler Paul , Brown Frank , Camilleri Patrick , Carpenter David , George Ashley , Gray Carol , Haran Margaret , Stewart Brian
Published: July 2002

Canine and porcine cerebrospinal fluid (CSF) were fractionated by size exclusion chromatography and analysed by a luminescence enzyme linked immunosorbent assay (ELISA) configured to detect β‐amyloid. A peak of activity was observed in the CSF consistent with the molecular weight of β‐amyloid. When CSF contaminated with blood was analysed an additional peak of immunoreactivity at a higher molecular weight was observed. The peak of activity was found to be derived from cross‐reactivity of the immunoglobulins employed in the ELISA with haemoglobin. These findings are discussed with reference to primary and structural sequence homology between β‐amyloid and haemoglobin from a number of species, the known properties of β‐amyloid and recent clinical reports.
Essential role of the first intron in the transcription of hsp90β gene
Authors: Shen Yu-fei , Liu Ju-hong , Wang Xiao-zhe , Cheng Xiao-kuan , Wang Yan-lin , Wu Ning-hua
Published: July 2002

The human HSP90 gene family contains introns. There are two typical heat shock elements (HSE) in the first intron of human hsp90β gene. As detected by chloramphenicol acetyl transferase (CAT) reporter activity assays, the HSE‐containing intron is essential in maintaining high constitutive expression and is critical for heat shock inducibility of the human hsp90β gene. Cellular heat shock factor 1 (HSF 1) shows much higher binding affinity toward the intronic HSEs in comparison to an atypical HSE in the 5′ flanking sequence. Novel initiation sites found in the first intron probably also contribute to constitutive and heat‐inducible expression of the hsp90β gene in Jurkat cells.
Photoaffinity labelling of P‐glycoprotein catalytic sites
Authors: Sankaran Banumathi , Bhagat Sumedha , Senior Alan E
Published: July 2002

Photoaffinity labelling of hamster P‐glycoprotein was carried out after trapping of radioactive Mg‐8‐azido‐ADP in the catalytic sites by vanadate or beryllium fluoride. With either trapping agent the same labelled peptide was obtained in homogeneous form, with the sequence ‐FNEVVFNxPTRPDI‐, corresponding to residues 1034–1037 in the C‐terminal nucleotide binding site. The missing residue `x' corresponds to Tyr‐1041, which is therefore a primary reaction target of 8‐azido‐ADP. This tyrosine is conserved in all hamster, mouse and human P‐glycoproteins. A second major labelled peptide fraction was also identified. The major sequence in this fraction was ‐NIHFSxPSR‐, corresponding to residues 393–401 of hamster P‐glycoprotein, where `x' corresponds to Tyr‐398 in the N‐terminal nucleotide binding site. Therefore Tyr‐398, which is also conserved in other P‐glycoproteins, is also a reaction target for 8‐azido‐ADP. In sequence alignment of the two nucleotide binding sites, Tyr‐398 exactly corresponds to Tyr‐1041. The data indicate that these two tyrosines lie close to the adenine ring of bound substrate MgATP in the respective catalytic sites of P‐glycoprotein.
Variability of DNA methylation pattern in somatic and germ cells in male newt (Amphibia, Urodela) Triturus cristatus carnifex
Authors: Pontecorvo Giovanni , De Felice Bruna , Carfagna Mario
Published: July 2002

In a survey of several mammalian genomes, namely humans, rodents and bovines, the differences in the 5‐methylcytosine (m5C) content show that repeated DNA sequences from sperm were undermethylated and from various somatic tissues were heavily methylated. This report shows a pattern of methylation in male newt (Amphibia, Urodela) Triturus cristatus carnifex (T. c. c.) unlike that so far described by other authors in mammals. Using methylation sensitive and insensitive enzymes (HpaII and MspI) and successive 3′ terminal labelling (fill‐in), we found a greater degree of DNA methylation in premeiotic germ and sperm cells compared to somatic tissue such as hepatocytes. Furthermore the degree of total DNA methylation in spermatozoa appears somewhere between premeiotic germ cells and somatic tissue. Blot hybridization shows that two highly conserved repetitive sequences in amphibian T. c. c., pTvm1 and pTvm8, contribute significantly to the degree of DNA methylation, suggesting a function for these sequences, such as a role in transcriptional regulation.
A structural tree for proteins containing S‐like β‐sheets
Authors: Efimov Alexander V
Published: July 2002

A structural tree for proteins and domains containing S‐like β‐sheets has been constructed. An S‐like β‐sheet is taken as a starting structure in modelling or as a root structure of the tree. Larger structures are obtained by a stepwise addition of β‐strands and/or α‐helices to the root S‐like β‐sheet in accordance with a restricted set of rules inferred from known principles of protein structure. Applications of the structural tree to structure comparison, protein classification and protein folding are described.
Combinatorial synthesis of ω‐conotoxin MVIIC analogues and their binding with N‐ and P/Q‐type calcium channels
Authors: Sasaki Toru , Kobayashi Kuniko , Kohno Toshiyuki , Sato Kazuki
Published: July 2002

ω‐Conotoxin MVIIC (MVIIC) blocks P/Q‐type calcium channels with high affinity and N‐type calcium channels with low affinity, while the highly homologous ω‐conotoxin MVIIA blocks only N‐type calcium channels. We wished to obtain MVIIC analogues more selective for P/Q‐type calcium channels than MVIIC to elucidate structural differences among the channels, which discriminate the ω‐conotoxins. To prepare a number of MVIIC analogues efficiently, we developed a combinatorial method which includes a random air oxidation step. Forty‐seven analogues were prepared in six runs and some of them exhibited higher selectivity for P/Q‐type calcium channels than MVIIC in binding assays.
Manufacturing flexibility: methods for measuring the impact of product variety on performance in process industries
Authors: Berry William L. , Cooper Martha C.
Published: July 2002

Product variety is often assumed to yield competitive advantage by offering products or services tailored to specific market segments. This strategy should result in more total sales volume or higher prices, and presumed profit, gained by meeting more specialized demands. However, achieving competitive advantage through increased product variety is heavily dependent on the proper alignment of the marketing and manufacturing strategies. This paper shows that adding product variety can have adverse cost and margin implications when marketing and manufacturing strategies are mis‐aligned. The critical strategic issues involve product pricing and manufacturing flexibility in product mix. We report methods that can be used to measure product mix flexibility and manufacturing performance in terms of costs and margins based on actual orders and production data. Such methods provide a means of empirically diagnosing the degree of strategic mis‐match using actual operating data. These methods are general in nature, and have been tested in field research on high volume batch processes that are representative of many firms in process industries. The results show that gaining competitive advantage through increased product variety requires a clear understanding of the process choice required to support the contemplated range of product volumes, and the cost and profitability trade‐offs involved.
Perceived curative factors and their relationship to outcome: a study of schizophrenic patients in a comprehensive treatment program based on cognitive therapy
Authors: Svensson B , Hansson L
Published: July 2002

Twenty-eight schizophrenic and other long-term mentally ill patients who were given cognitive therapy sessions twice a week in the context of a comprehensive inpatient treatment program were assessed every 5 weeks regarding perceived curative factors. The assessments were made by a self-rating questionnaire (Curative Factors Questionnaire [CFQ]) and a qualitative assessment from the patients of what they perceived as helpful in treatment. The results showed that milieu therapeutic elements and therapy sessions were perceived as the most helpful throughout the treatment period. No correlations were found between patient characteristics and perceived curative factors. The factors “instillation of hope”, “problem solution” and “learning I’m not alone” as rated in the initial phase of treatment showed a positive relationship with a favourable outcome of treatment at discharge.
Temperature‐Dependent Dynamic Strain Aging in Selective Laser Melted 316L
Authors: Diepold Benedikt , Neumeier Steffen , Meermeier Annalena , Höppel Heinz Werner , Sebald Torsten , Göken Mathias
Published: June 2021

Additively manufactured austenitic stainless steel AISI 316L (EN 1.4404, X2CrNiMo17‐12‐2) is used at higher temperatures, e.g., in space applications. However, the high‐temperature properties of such materials have not been analyzed in detail yet. Thus, selective laser melted (SLM) 316L is tested in the solution‐annealed condition by compression and tensile tests at temperatures between 25 and 877 °C. The compressive strength of SLM 316L is higher in comparison with the conventionally produced reference material due to hardening by a high dislocation density and a fine substructure. However, tensile tests reveal a loss in ductility of the SLM material at temperatures between 300 and 627 °C, where the elongation to fracture is reduced from 65% to 39%. Alloying elements cause serrated yielding in the affected temperature range. Together with an increased normalized work‐hardening rate and a negative strain rate sensitivity, dynamic strain aging is found to cause the reduction of ductility.
Healable and Recyclable Elastomers with Record‐High Mechanical Robustness, Unprecedented Crack Tolerance, and Superhigh Elastic Restorability
Authors: Li Zequan , Zhu You‐Liang , Niu Wenwen , Yang Xiao , Jiang Zhiyong , Lu Zhong‐Yuan , Liu Xiaokong , Sun Junqi
Published: June 2021

Spider silk is one of the most robust natural materials, which has extremely high strength in combination with great toughness and good elasticity. Inspired by spider silk but beyond it, a healable and recyclable supramolecular elastomer, possessing superhigh true stress at break (1.21 GPa) and ultrahigh toughness (390.2 MJ m−3), which are, respectively, comparable to and ≈2.4 times higher than those of typical spider silk, is developed. The elastomer has the highest tensile strength (ultimate engineering stress, 75.6 MPa) ever recorded for polymeric elastomers, rendering it the strongest and toughest healable elastomer thus far. The hyper‐robust elastomer exhibits superb crack tolerance with unprecedentedly high fracture energy (215.2 kJ m−2) that even exceeds that of metals and alloys, and superhigh elastic restorability allowing dimensional recovery from elongation over 12 times. These extraordinary mechanical performances mainly originate from the meticulously engineered hydrogen‐bonding segments, consisting of multiple acylsemicarbazide and urethane moieties linked with flexible alicyclic hexatomic spacers. Such hydrogen‐bonding segments, incorporated between extensible polymer chains, aggregate to form geometrically confined hydrogen‐bond arrays resembling those in spider silk. The hydrogen‐bond arrays act as firm but reversible crosslinks and sacrificial bonds for enormous energy dissipation, conferring exceptional mechanical robustness, healability, and recyclability on the elastomer.
Lessons learned from Ohio workers' compensation claims to mitigate hazards in the landscaping services industry
Authors: Alexander Barbara M. , Wurzelbacher Steven J. , Zeiler Rachel J. , Naber Steven J.
Published: June 2021

Background

The landscaping services industry is one of the more dangerous in the United States, with higher rates of both fatal and nonfatal injuries than the all‐industry average. This study uses claims from the Ohio Bureau of Workers' Compensation (OHBWC) database to identify high rates of occupational injuries and illnesses in this industry in Ohio. The causes of those illnesses and injuries are highlighted to identify common factors.

Methods

The OHBWC database includes injured‐worker industry identification, occupation, business size, demographics, diagnoses, and free‐text descriptions of injury circumstances. We identified landscaping service industry claims from 2001 to 2017, and describe annual claim counts and rates.

Results

Over the 17‐year period, 18,037 claims were accepted, with “Struck by object or equipment” and “Overexertion involving outside sources” being the most common events or exposures. Sprains and fractures were the most prevalent of the more serious lost‐time (LT) injuries. Free‐text descriptions of claims indicate that arborist work and loading/unloading of work vehicles and trailers are particularly hazardous. Younger and shorter‐tenured workers were injured most frequently, although the average workers' age was higher for LT claims. The total cost of claims to the OHBWC from the landscaping services industry for 2001–2017 was over $226,000,000. Almost $214,000,000, or 94.4%, was for LT injuries and illnesses, even though LT claims comprise only 18% of total claims.

Conclusions

Targeted improvements in landscaper safety could come from controlling events leading to LT claims. Engineering controls and improved training are strongly recommended to reduce falls, overexertion, and struck‐by injuries.
A rare description of pure partial trisomy of 16q12.2q24.3 and review of the literature
Authors: Manor Joshua , Dinu Daniela , Azamian Mahshid S. , Bi Weimin , Darilek Sandra , Lalani Seema R.
Published: June 2021

Trisomy 16 is the most common autosomal trisomy in humans, which is almost uniformly embryonic lethal. Partial trisomy 16 including a segment of the long arm of chromosome 16 is occasionally compatible with life and has been associated with severe congenital defects, growth retardation, and early lethality. Segmental trisomy of 16q is usually described concomitantly with partial monosomy of another chromosome, often resulting from a parental balanced translocation. Pure partial chromosome 16q trisomy is exceedingly rare. About nine children with 16q12→qter and 16q13→qter duplication have been reported in the literature, almost all described with monosomy of a second chromosome, and highlighting very few long‐term survivors. A single individual with pure partial distal 16q12.1q23.3 duplication has been reported in an infant, underscoring complexities of genetic counseling and management, especially in view of life‐limiting congenital anomalies in rare survivors. Here, we present a 12‐month‐old child with pure 16q12.2q24.3 trisomy, having continued morbidity related to pulmonary hypertension and chronic lung disease. The features of intrauterine growth retardation, facial dysmorphism, hypotonia, congenital heart defect, distal contractures, urogenital abnormalities, and hearing loss support the association with 16q partial trisomy, as in previous studies. This report expands our current understanding related to the survival of infants with large segmental aneusomy of the long arm of chromosome 16.
Recurrent KCNT2 missense variants affecting p.Arg190 result in a recognizable phenotype
Authors: Jackson Adam , Banka Siddharth , Stewart Helen ,   Genomics England Research Consortium, Robinson Hannah , Lovell Simon , Clayton‐Smith Jill
Published: June 2021

KCNT2 variants resulting in substitutions affecting the Arg190 residue have been shown to cause epileptic encephalopathy and a recognizable facial gestalt. We report two additional individuals with intellectual disability, dysmorphic features, hypertrichosis, macrocephaly and the same de novo KCNT2 missense variants affecting the Arg190 residue as previously described. Notably, neither patient has epilepsy. Homology modeling of these missense variants revealed that they are likely to disrupt the stabilization of a closed channel conformation of KCNT2 resulting in a constitutively open state. This is the first report of pathogenic variants in KCNT2 causing a developmental phenotype without epilepsy.
Pyridine Ring Modification of Indane‐1,3‐dione Dimers for Control of their Crystal Structure
Authors: Yakiyama Yumi , Fujinaka Takahisa , Nishimura Mio , Seki Ryotaro , Sakurai Hidehiro
Published: June 2021

Four 2,2′‐dipyridylindane‐1,3‐dione 2,2′‐dimers with various substituents and orientations of the pyridine rings were synthesized. Detailed analyses of their crystal structures revealed how the atomic geometry around the pyridine N‐atom affects the selective formation of a 1D‐channel‐containing open‐type structure, observed as a major packing structure of the previously reported 2,2′‐di(4‐pyridyl) analogue (4PID). DFT‐based QTAIM and noncovalent interaction index‐reduced density gradient analyses afforded qualitative information on the intra‐ and intermolecular interactions in the open‐type structure of 4PID and in a hypothetical open‐type structure of its 2‐pyridyl analogue that was not observed experimentally. They also indicated that interactions between the framework and channel‐incorporated solvents, rather than N‐atom‐related intermolecular interactions, make a significant contribution to stabilization of the open‐type structure.
Diversity‐Oriented Synthesis of Aliphatic Fluorides via Reductive C(sp3)−C(sp3) Cross‐Coupling Fluoroalkylation
Authors: Sheng Jie , Ni Hui‐Qi , Ni Shan‐Xiu , He Yan , Cui Ru , Liao Guang‐Xu , Bian Kang‐Jie , Wu Bing‐Bing , Wang Xi‐Sheng
Published: June 2021

Monofluorinated alkyl compounds are of great importance in pharmaceuticals, agrochemicals and materials. Herein, we describe a direct nickel‐catalyzed monofluoromethylation of unactivated alkyl halides using a low‐cost industrial raw material, bromofluoromethane, by demonstrating a general and efficient reductive cross‐coupling of two alkyl halides. Results with 1‐bromo‐1‐fluoroalkane also demonstrate the viability of monofluoroalkylation, which further established the first example of reductive C(sp3)‐C(sp3) cross‐coupling fluoroalkylation. These transformations demonstrate high efficiency, mild conditions, and excellent functional‐group compatibility, especially for a range of pharmaceuticals and biologically active compounds. Mechanistic studies support a radical pathway. Kinetic studies reveal that the reaction is first‐order dependent on catalyst and alkyl bromide whereas the generation of monofluoroalkyl radical is not involved in the rate‐determining step. This strategy provides a general and efficient method for the synthesis of aliphatic fluorides.
Heterogeneously Catalyzed Aerobic Oxidation of Methane to a Methyl Derivative
Authors: Blankenship Andrea N. , Ravi Manoj , Newton Mark A. , van Bokhoven Jeroen A.
Published: June 2021

A promising strategy to break through the selectivity‐conversion limit of direct methane conversion to achieve high yields is the protection of methanol via esterification to a more stable methyl ester. We present an aerobic methane‐to‐methyl‐ester approach that utilizes a highly dispersed, cobalt‐containing solid catalyst, along with significantly more favorable reaction conditions compared to existing homogeneously‐catalyzed approaches (e.g. diluted acid, O2 oxidant, moderate temperature and pressure). The trifluoroacetic acid medium is diluted (<25 wt %) with an inert fluorous co‐solvent that can be recovered after the separation of the methyl trifluoroacetate via liquid–liquid extraction at ambient conditions. Silica‐supported cobalt catalysts are highly active in this system, with competitive yields and turnovers in comparison to known aerobic transition metal‐based catalytic systems.
Tight Covalent Organic Framework Membranes for Efficient Anion Transport via Molecular Precursor Engineering
Authors: Kong Yan , He Xueyi , Wu Hong , Yang Yi , Cao Li , Li Runlai , Shi Benbing , He Guangwei , Liu Yiqin , Peng Quan , Fan Chunyang , Zhang Zhenjie , Jiang Zhongyi
Published: June 2021

Fabricating covalent organic frameworks (COFs) membranes with tight structure, which can fully utilize well‐defined framework structure and thus achieve superior conduction performance, remains a grand challenge. Herein, through molecular precursor engineering of COFs, we reported the fabrication of tight COFs membrane with the ever‐reported highest hydroxide ion conductivity over 200 mS cm−1 at 80 °C, 100 % RH. Six quaternary ammonium‐functionalized COFs were synthesized by assembling functional hydrazides and different aldehyde precursors. In an organic‐aqueous reaction system, the impact of the aldehyde precursors with different size, electrophilicity and hydrophilicity on the reaction‐diffusion process for fabricating COFs membranes was elucidated. Particularly, more hydrophilic aldehydes were prone to push the reaction zone from the interface region to the aqueous phase of the reaction system, the tight membranes were thus fabricated via phase‐transfer polymerization process, conferring around 4–8 times the anion conductivity over the loose membranes via interfacial polymerization process.
N‐Heterocyclic Carbene‐Stabilized Ultrasmall Gold Nanoclusters in a Metal‐Organic Framework for Photocatalytic CO2Reduction
Authors: Jiang Yilin , Yu Yuan , Zhang Xu , Weinert Micha , Song Xueling , Ai Jing , Han Lu , Fei Honghan
Published: June 2021

Ultrafine gold nanoclusters (Au‐NCs) are susceptible to migrate and aggregate, even in the porosity of many crystalline solids. N‐heterocyclic carbenes (NHCs) are a class of structurally diverse ligands for the stabilization of Au‐NCs in homogeneous chemistry, showing catalytic reactivity in CO2activation. Herein, for the first time, we demonstrate a heterogeneous nucleation approach to stabilize ultrasmall and highly dispersed gold nanoclusters in an NHC‐functionalized porous matrix. The sizes of gold nanoclusters are tunable from 1.3 nm to 1.8 nm based on the interpenetration of the metal‐organic framework (MOF) topology. Control experiments using amine or imidazolium‐functionalized MOFs afforded the aggregation of Au species. The resultant Au‐NC@MOF composite exhibits a steady and excellent activity in photocatalytic CO2reduction, superior to control mixtures without NHC‐ligand stabilization. Mechanistic studies reveal the synergistic catalytic effect of MOFs and Au‐NCs through the MOF‐NHC‐Au covalent‐bonding bridges.
Ambient Hydrogenation and Deuteration of Alkenes Using a Nanostructured Ni‐Core–Shell Catalyst
Authors: Gao Jie , Ma Rui , Feng Lu , Liu Yuefeng , Jackstell Ralf , Jagadeesh Rajenahally V. , Beller Matthias
Published: June 2021

A general protocol for the selective hydrogenation and deuteration of a variety of alkenes is presented. Key to success for these reactions is the use of a specific nickel‐graphitic shell‐based core–shell‐structured catalyst, which is conveniently prepared by impregnation and subsequent calcination of nickel nitrate on carbon at 450 °C under argon. Applying this nanostructured catalyst, both terminal and internal alkenes, which are of industrial and commercial importance, were selectively hydrogenated and deuterated at ambient conditions (room temperature, using 1 bar hydrogen or 1 bar deuterium), giving access to the corresponding alkanes and deuterium‐labeled alkanes in good to excellent yields. The synthetic utility and practicability of this Ni‐based hydrogenation protocol is demonstrated by gram‐scale reactions as well as efficient catalyst recycling experiments.
Surface Engineering and Controlled Ripening for Seed‐Mediated Growth of Au Islands on Au Nanocrystals
Authors: Feng Ji , Xu Dongdong , Yang Fan , Chen Jinxing , Wu Chaolumen , Yin Yadong
Published: June 2021

Engineering the nucleation and growth of plasmonic metals (Ag and Au) on their pre‐existing seeds is expected to produce nanostructures with unconventional morphologies and plasmonic properties that may find unique applications in sensing, catalysis, and broadband energy harvesting. Typical seed‐mediated growth processes take advantage of the perfect lattice match between the deposited metal and seeds to induce conformal coating, leading to either simple size increases (e.g., Au on Au) or the formation of core–shell structures (e.g., Ag on Au) with limited morphology change. In this work, we show that the introduction of a thin layer of metal with considerable lattice mismatch can effectively induce the nucleation of well‐defined Au islands on Au nanocrystal seeds. By controlling the interfacial energy between the seed and the deposited material, the oxidative ripening, and the surface diffusion of metal precursors, we can regulate the number of islands on the seeds and produce complex Au nanostructures with morphologies tunable from core‐satellites to tetramers, trimers, and dimers.
The effect of multiscale hybridization on the mechanical properties of natural fiber‐reinforced composites
Authors: Fernandes Medeiros de Queiroz Henrique , Banea Mariana Doina , Kioshi Kawasaki Cavalcanti Daniel , de Souza e Silva Neto Jorge
Published: June 2021

The main objective of this work was to investigate the effect of reinforcements at different scales on the mechanical properties of natural fiber‐reinforced composites. Pure jute and interlaminar hybrid jute/glass fiber‐reinforced polymer composites were fabricated. Different types of fillers in two weight fractions (1 and 3 wt. %) were used as second reinforcements in the hybrid jute/glass composites. Tensile, flexural, and impact tests were performed. It was found that the macroscale inter‐play hybridization significantly improved the mechanical properties of the pure jute fiber based composites. When the fillers are used as second hybridization, the modified composites presented higher mechanical properties when compared to pure jute composites. However, the effect of fillers on the mechanical properties of the hybrid composites presented various trends due to the interaction between several factors (i.e., particle scale, content, and nature), which cannot always be separated. Increasing the synthetic filler content improved the tensile properties of the filled hybrid composites, while increasing the natural filler content worsen the tensile properties. The flexural strength of the multiscale hybrid composites was improved, while the impact properties were negatively affected.
A new score including CD43 and CD180: Increased diagnostic value for atypical chronic lymphocytic leukemia
Authors: Li Yi , Tong Xiwen , Huang Lifang , Li Li , Wang Chunyan , He Cheng , Liu Songya , Wang Zhiqiong , Xiao Min , Mao Xia , Zhang Donghua
Published: June 2021

Moreau score has been used to differentiate chronic lymphocytic leukemia (CLL) from other mature B‐cell neoplasms. However, it showed limitations in Asian patients. Therefore, we conducted a new score system replacing CD5 and CD23 with CD43 and CD180 to evaluate its diagnostic value of CLL. 237 untreated samples diagnosed with mature B‐cell neoplasms were collected and were randomly divided into an exploratory and a validation cohort by a 2:1 ratio. The expression of CD5, CD19, CD20, CD23, CD43, CD79b, CD180, CD200, FMC7, and surface immunoglobulin (SmIg) were analyzed among all the samples. A proposed score was developed based on the logistic regression model. The sensitivity and specificity of the proposed score were calculated by ROC curves. CD43/CD180, CD200, FMC7, and CD79b were included in our new CLL score, which showed a sensitivity of 91.8% and a specificity of 83.1%. These results were confirmed in a validation cohort with a sensitivity of 90.5% (p = 0.808) and a specificity of 79.5% (p = 0.639). In CD5 negative or CD23 negative CLL group, the new CLL score displayed improved sensitivity of 79.4% compared to Moreau score and CLLflow score (41.2% and 47.1%, respectively). In atypical CLL group, the new CLL score showed improved sensitivity of 84.2% compared to Moreau score and CLLflow score (61.4% and 64.9%, respectively). This proposed atypical CLL score helped to offer an accurate differentiation of CLL from non‐CLL together with morphological and molecular methods, particularly in Chinese patients with atypical immunophenotype.
Impact of high‐sensitivity cardiac troponin T on survival and rehospitalization after transcatheter aortic valve replacement
Authors: Schoechlin Simon , Schulz Undine , Ruile Philip , Hein Manuel , Eichenlaub Martin , Jander Nikolaus , Neumann Franz‐Josef , Valina Christian
Published: June 2021

Background

Constant elevations of the serum concentration of cardiac troponin T (TnT) indicate a myocardial injury that may affect the long‐term outcome of transcatheter aortic valve replacement (TAVR).

Objectives

We sought to investigate the impact of pre‐TAVR TnT on outcomes after TAVR during long‐term follow‐up.

Methods

In a retrospective, observational study we compared long term outcomes after TAVR between tertiles of preinterventional high‐sensitivity TnT. Systematic follow‐up was performed annually for 5 years. The primary endpoint was a composite of all‐cause death and any rehospitalization.

Results

Between 2010 and 2018, 2,129 patients with severe aortic valve stenosis underwent TAVR at our institution (mean age 82.6 years, 57.2% female, logistic EuroSCORE 20.5 ± 15.8). Boundaries for TnT tertiles were <21 ng/L and >42 ng/L. The median follow‐up was 895 days. Three‐year incidences for the primary endpoint were 70.9%, 76.6%, and 81.7% in the low, middle, and high tertile (log rank p < .001). Compared with the first tertile, the corresponding adjusted hazard ratios were 1.23 (95%‐CI 1.08–1.40, p < .001) and 1.50 (95%‐CI 1.32–1.70, p < .001) for the second and third tertile. We found consistent differences between TnT strata for all‐cause death (3‐year incidences 23.3%, 33.3%, and 47.1%; adjusted p < .001) and rehospitalization (3‐year incidences 64.7%, 68.7% and 72.0%; adjusted p < .001), including significant differences in deaths (p < .001). The association between TnT and outcome was independent of coronary artery disease or low aortic valve gradient.

Conclusions

TnT before TAVR is strongly associated with all‐cause death and rehospitalization during 3‐year follow‐up.
Impact of Liquid Composition and Asphaltene Properties on Asphaltene Aggregation Using Interaction Energies
Authors: Nategh Mahshid , Mahdiyar Hojjat , Malayeri M. Reza , Unz Simon , Beckmann Michael
Published: June 2021

An interaction energy model is employed to discern the roles of liquid composition and asphaltene properties on asphaltene stability. The model determines Lifshitz‐van der Waals (LW) and acid‐base (AB) for two asphaltenes of A and B types with different polarities and synthetic oils with different nC7 volume fractions. The results indicate that the liquid loses its solubility with increased nC7 volume fraction, due to the reduction in its electron donor component. Moreover, at the very beginning of nC7 addition, both asphaltenes show a similar resistance against aggregation, due to the similar rates of change in their LW and AB interaction energies. However, at latter stages of nC7 addition, the two asphaltenes tend to have different precipitation propensities, which is consistent with the results of UV‐vis measurements.
Frustrated Lewis‐Pair Neighbors at the Xanthene Framework: Epimerization at Phosphorus and Cooperative Formation of Macrocyclic Adduct Structures
Authors: Škoch Karel , Daniliuc Constantin G. , Kehr Gerald , Ehlert Sebastian , Müller Marcel , Grimme Stefan , Erker Gerhard
Published: June 2021

Attachment of a pair of P‐stereogenic mesityl(alkynyl)phosphanyl groups at the 4‐ and 5‐positions of a 9,9‐dimethylxanthene framework gave mixtures of the respective rac‐ and meso‐bisphosphanyl diastereoisomers. They slowly epimerized in a thermally induced reaction with Gibbs activation barriers of about 25 kcal mol−1 at room temperature (measured and DFT calculated). The reaction of the meso‐mesityl(tert‐butylethynyl)phosphanyl derivative with two molar equivalents of Piers′ borane [HB(C6F5)2] led to the formation of the alkylidene‐bridged geminal bisphosphane/borane‐frustrated Lewis pair system. The compound was obtained enriched (>85 %) in the rac diastereoisomer. With a variety of bifunctional donor substrates, the rac‐bis‐P/B FLP formed macrocyclic compounds. They were all formally derived from meso‐configurated diastereoisomers of the bisphosphanylxanthene backbone.
Molecular Cage Assembly by Sn−O−Sn Bridging of Di‐, Tri‐ and Tetranuclear Organotin Tectons: Extending the Spacing in Double Ladder Structures
Authors: Rojas‐León Irán , Gómez‐Jaimes Gelen , Montes‐Tolentino Pedro , Hiller Wolf , Alnasr Hazem , Rodríguez‐Molina Braulio , Hernández‐Ahuactzi Irán F. , Beltrán Hiram , Jurkschat Klaus , Höpfl Herbert
Published: June 2021

Hydrolysis reactions of di‐ and trinuclear organotin halides yielded large novel cage compounds containing Sn−O−Sn bridges. The molecular structures of two octanuclear tetraorganodistannoxanes showing double‐ladder motifs, viz., [{Me3SiCH2(Cl)SnCH2YCH2Sn(OH)CH2SiMe3}2(μ‐O)2]2 [1, Y=p‐(Me)2SiC6H4‐C6H4Si(Me)2] and [{Me3SiCH2(I)SnCH2YCH2Sn(OH)CH2SiMe3}2(μ‐O)2]2⋅0.48 I2 [2⋅0.48 I2, Y=p‐(Me)2SiC6H4‐C6H4Si(Me)2], and the hexanuclear cage‐compound 1,3,6‐C6H3(p‐C6H4Si(Me)2CH2Sn(R)2OSn(R)2CH2Si(Me)2C6H4‐p)3C6H3‐1,3,6 (3, R=CH2SiMe3) are reported. Of these, the co‐crystal 2⋅0.48 I2 exhibits the largest spacing of 16.7 Å reported to date for distannoxane‐based double ladders. DFT calculations for the hexanuclear cage and a related octanuclear congener accompany the experimental work.
An evaluation of memory and attention in BRCA mutation carriers using an online cognitive assessment tool
Authors: Kotsopoulos Joanne , Kim Shana J. , Armel Susan , Bordeleau Louise , Foulkes William D. , McKinnon Wendy , Panchal Seema , Cohen Stephanie A. , Sun Sophie , Sun Ping , McKetton Larissa , Troyer Angela K. , Narod Steven A.
Published: June 2021

Background

The objective of this study was to evaluate the impact of various surgical, hormonal, and lifestyle factors on memory and attention in women with a BRCA1 or BRCA2 mutation.

Methods

BRCA mutation carriers enrolled in a longitudinal study were invited to complete an online brain health assessment tool designed to screen for cognitive deficits. Four measures of memory and executive attention were assessed individually, and an overall score was compiled adjusting for age. Exposures, including preventive surgery, hormone use, and lifestyle factors, were captured by questionnaire. Performance on each of the 5 subtasks was analyzed according to various exposures. Analysis of covariance was used to compare overall scores.

Results

In total, 880 women completed the online cognitive assessment. The average age of the participants was 54 years (range, 23‐86 years). The mean overall test score was 54.4 (range, 0‐93). The individual subtask scores declined with age at test completion (P < .0001) and increased with level of education (P ≤ .01). Women who underwent a preventive oophorectomy had a significantly higher overall score compared with women who did not undergo this surgery (55.5 vs 50.5; P = .01). Reconstructive breast surgery was also associated with a higher overall score (56.5 vs 52.3; P = .005). Chemotherapy and hormone‐replacement therapy were not predictive of the overall score.

Conclusions

These findings are reassuring to high‐risk women who undergo early surgical menopause for their cancer predisposition. Further studies are needed to evaluate cognitive function over time when memory deficits become more prevalent.
A multiprimary lighting system for customized color stimuli
Authors: Yuan Yue , Murdoch Michael J. , Fairchild Mark D.
Published: June 2021

In this article, a dual seven‐primary lighting system is constructed for color research and education. The system offers sufficient spectral variability to approximate the spectral power distribution of a variety of standard illuminants. More importantly, the constructed multiprimary lighting system was verified to have crucial advantages over conventional displays/projectors to probe observer metamerism through the generation of individualized metameric color stimuli. An observer metamerism index to describe the potential for observer metamerism of any generated stimulus pairs with respect to the population variation of color‐normal observers is formulated. The metric is further extended for use in quantifying the potential for observer metamerism of any lighting system or a system‐primary combination. Moreover, 10 pairs of lighting stimuli, customized for exhibiting high degrees of observer variability, were produced using the system as a step toward creating a device for the color matching functions characterization of individual observers, a so‐called observer calibrator.
Mean Convex Mean Curvature Flow with Free Boundary
Authors: Edelen Nick , Haslhofer Robert , Ivaki Mohammad N. , Zhu Jonathan J.
Published: June 2021

In this paper, we generalize White's regularity and structure theory for mean‐convex mean curvature flow [45, 46, 48] to the setting with free boundary. A major new challenge in the free boundary setting is to derive an a priori bound for the ratio between the norm of the second fundamental form and the mean curvature. We establish such a bound via the maximum principle for a triple‐approximation scheme, which combines ideas from Edelen [9], Haslhofer‐Hershkovits [16], and Volkmann [43]. Other important new ingredients are a Bernstein‐type theorem and a sheeting theorem for low‐entropy free boundary flows in a half‐slab, which allow us to rule out multiplicity 2 (half‐)planes as possible tangent flows and, for mean‐convex domains, as possible limit flows. © 2021 Wiley Periodicals LLC.
Enantioselective Organocatalytic Syntheses and Ring‐Expansions of Cyclobutane Derivatives
Authors: Barday Manuel , Bouillac Pierre , Coquerel Yoann , Amatore Muriel , Constantieux Thierry , Rodriguez Jean
Published: June 2021

The progress in enantioselective organocatalysis have enabled efficient and highly stereoselective syntheses of cyclobutane derivatives, through (2+2) annulation reactions, overcoming the geometrical constraints inherent to these small cyclic molecules. More importantly, and taking advantage of their strain‐releasing fragmentation, some cyclobutane derivatives, especially cyclobutanones and cyclobutenones, can now be regarded as versatile four‐carbon atoms units amenable to the enantioselective construction of larger rings by (4+n) annulation reactions to produce, five‐, six‐, seven‐ and eight‐membered cyclic products. These recent developments concerning the enantioselective synthetic chemistry of cyclobutane derivatives under organocatalytic conditions are reviewed herein.
The dynamics of commodity return comovements
Authors: Prokopczuk Marcel , Wese Simen Chardin , Wichmann Robert
Published: June 2021

We compare factor models with respect to their ability to explain commodity futures return comovements. A simple one‐factor model based on the first principal component extracted from a panel of commodity returns outperforms a macroeconomic model, and explains most of the realized comovements. We find that intersectoral correlations display more time variations than intrasectoral correlations. Dissecting the evidence further, we find that comovements are driven by the variation of the factor as opposed to exposure to it. Our results cast doubt on the persistence of the effects of financialization and emphasize the importance of the dynamics of the factor variance.
Locomotion and feeding trails produced by crabs
Authors: Lan Zhongwu , Zhang Shujing , Chen Zhong‐Qiang , Mitchell Ross N.
Published: June 2021

Trace fossils represent the biological activity of an organism in the form of trails, tracks, burrows, and borings in the geological record. Bilobate trails are known to be made by arthropod trilobites since the Early Palaeozoic. This study enhances the present state of knowledge regarding bilobate trails by demonstrating that they can also be produced by crabs reflecting different behavioural traits such as different feeding and locomotion strategies. This present‐day study thus warns caution to be taken when linking horizontal trails such as Archaeonassa and Diplopodichnus with tracemakers in Jurassic strata and onwards since crabs have existed. Identifying crab‐related trace fossils might be particularly insightful for understanding the earliest evolution of Jurassic crabs for which dorsal carapaces are dominantly the only form of preservation.
The balance between Bayesian inference and default mode determines the generation of tinnitus from decreased auditory input: A volume entropy‐based study
Authors: Song Jae‐Jin , Park Jaemin , Koo Ja‐Won , Lee Sang‐Yeon , Vanneste Sven , De Ridder Dirk , Hong Soonki , Lim Seonhee
Published: June 2021

Along with phantom pain, tinnitus, a phantom auditory perception occurring in the absence of an external acoustic stimulus, is one of the most representative phantom perceptions that develops in subjects with decreased peripheral sensory input. Although tinnitus is closely associated with peripheral hearing loss (HL), it remains unclear why only some individuals with HL develop tinnitus. In this study, we investigated the differences between 65 HL with tinnitus (HL‐T) and 104 HL with no tinnitus (HL‐NT) using a resting‐state electroencephalography data‐based volume entropy model of the brain network, by comparing the afferent node capacities, that quantify the contribution of each node to the spread of information, of all Brodmann areas. While the HL‐T group showed increased information flow in areas involved in Bayesian inference (the left orbitofrontal cortex, the left subgenual anterior cingulate cortex, and the left ventrolateral prefrontal cortex) and auditory memory storage (the right hippocampus/parahippocampus), the HL‐NT group showed increased afferent node capacity in hub areas of the default mode network (DMN; the right posterior cingulate cortex and the right medial temporal gyrus). These results suggest that the balance of activity between the Bayesian inferential network (updating missing auditory information by retrieving auditory memories from the hippocampus/parahippocampus) and DMN (maintaining the “silent status quo”) determines whether phantom auditory perception occurs in a brain with decreased peripheral auditory input.
CCL17‐CCR4 axis contributes to the onset of vitiligo in mice
Authors: Li He , Wang Congpin , Li Xiaoqing , Kong Yinghui , Sun Weiguo
Published: June 2021

Background

Destruction of melanocytes mediated by autoimmunity is currently believed as the main cause of vitiligo. This article aims to identify the role of CC chemokine ligand 17 (CCL17)–CC chemokine receptor 4 (CCR4) axis in vitiligo and provide new possibilities for the clinical treatment of vitiligo.

Methods

A total of 30 patients with vitiligo from Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University were recruited based on the inclusion and exclusion criteria. Trephine was used to obtain skin samples from the lesion area and its surrounding normal areas, and the expression levels of CCL17, CCR4, Tbx21, Eomes, and Blimp1 were determined by quantitative reverse transcription polymerase chain reaction. Vitiligo mouse model was established by adoptively transferring CFP‐PMEL CD8+ T cells into sublethally irradiated Krt14‐Kitl* mice. Recipient mice received intraperitoneal injection of 1 × 106 plaque‐forming units of rVV‐hPMEL on the same day of transfer. The degree of depigmentation was scored blindly by one observer 5 weeks after vitiligo induction. CFP‐PMEL CD8+ T cells migration to skin, draining lymph nodes, spleen, and blood were detected by flow cytometry. CCR4 blockade was performed by intraperitoneal injection of neutralizing antibody.

Results

The expression levels of CCL17, CCR4, Tbx21, Eomes, and Blimp1 in skin lesions were significantly increased compared with that in surrounding normal areas. CCL17−/− and CCR4−/− mice exhibited significantly lower disease scores than WT mice. The CFP‐PMEL CD8+ T cells accumulation was significantly decreased in the skin of CCL17−/− and CCR4−/− mice, but was not changed in draining lymph nodes, spleen, and blood. Administration of CCR4 neutralizing antibody decreased the degree of depigmentation and the recruitment of CFP‐PMEL CD8+ T cells to the skin, while keeping the number of T cells in draining lymph nodes unchanged.

Conclusion

Targeting CCL17‐CCR4 axis might inhibit T cell migrating to skin and alleviate vitiligo progression.
Inhibiting the JNK/ERK signaling pathway with geraniol for attenuating the proliferation of human gastric adenocarcinoma AGS cells
Authors: Yang Hongwei , Liu Guanghui , Zhao Hongchao , Dong Xinhua , Yang Zhen
Published: June 2021

Geraniol, a natural compound found in the essential oils of various aromatic plants, has attracted attention for its probable anticancer effects. The molecular mechanisms of the cell proliferation suppression and apoptosis induction via geraniol in gastric cancer cells (AGS), however, remain unclear. Gastric cancer cells were treated with geraniol, and it was found that the IC50 values were 25 μM/ml, as determined by the 3‐(4,5‐dimethylthiazol‐2‐yl)−2,5‐diphenyltetrazolium bromide assay. Results showed that 20 and 25 μM geraniol‐induced reactive oxygen species (ROS) production (2ʹ‐7ʹdichlorofluorescin diacetate staining) and decreased mitochondrial membrane potential (rhodamine 123 staining) in AGS cells. Then, it effectively inhibited cell growth and induced apoptosis, confirmed through acridine orange/ethidium bromide, 4′,6‐diamidino‐2‐phenylindole, and propidium iodide staining and molecular marker analysis in AGS cells. Also, geraniol potently diminished caspase‐9, Bax, Bcl‐2, and caspase‐3 expression in AGS cells. We also evaluated the essential mechanism of the cytotoxic effect of geraniol. Moreover, the present study depicted that geraniol‐induced cell death through mitochondrial ROS production and inhibited the phosphorylation form of mitogen‐activated protein kinase (p38, MAPK, JNK, and ERK1/2) signaling pathway. Taken together, these results concluded that geraniol has a novel therapeutic property against human stomach cancer.