bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioavailability of rutin and quercetin in rats
Authors: Manach Claudine , Morand Christine , Demigné Christian , Texier Odile , Régérat Françoise , Rémésy Christian
Published: July 2002

Quercetin is a powerful antioxidant which is widely distributed in edible plants, mainly as glycosides such as rutin. It has been reported to be absorbed in mammals, but its metabolism needs further investigation to evaluate its possible physiological effects. We compared the evolution of the absorption of quercetin and rutin in rats fed with supplemented diets. Rutin was absorbed more slowly than quercetin because it must be hydrolysed by the cecal microflora, whereas quercetin was absorbed from the small intestine. Conjugated derivatives of quercetin, and its methylated forms isorhamnetin and tamarixetin, were recovered in plasma from rats receiving the two kinds of experimental diets after the first meal, but after 10 days, no traces of tamarixetin were detected anymore. The rate of elimination of quercetin metabolites seems very low, and high plasma concentrations are easily maintained with a regular supply of quercetin or rutin in the diet.
BIT, an immune antigen receptor‐like molecule in the brain1
Authors: Sano Shin-ichiro , Ohnishi Hiroshi , Omori Akira , Hasegawa Junko , Kubota Misae
Published: July 2002

We previously found a brain‐specific glycoprotein in the rat brain. It postnatally increases and is rich in the mature brain. We cloned cDNA of this protein. It is composed of a signal peptide, a V‐type immunoglobulin domain, two C1‐type immunoglobulin domains, a transmembrane segment and a cytoplasmic region containing two tyrosine‐based activation motifs (TAM) that are variants of the antigen receptor signaling motifs. The overall structure is similar to those of immune antigen receptors. This molecule, BIT (brain immunoglobulin‐like molecule with TAMs), is a major endogenous substrates of brain tyrosine kinases in vitro. Cerebral cortical neurons could extend their neurites on BIT‐coated substrate and anti‐BIT monoclonal antibody specifically inhibited the effect. These findings and our recent study concerning BIT signal transduction mechanism suggest that BIT, an immune antigen receptor‐like molecule of the brain, functions as a membrane signaling molecule that may participate in cell–cell interaction.
Purification and characterization of a flavohemoglobin from the denitrifying fungus Fusarium oxysporum
Authors: Takaya Naoki , Suzuki Sawako , Matsuo Masaru , Shoun Hirofumi
Published: July 2002

A flavohemoprotein was purified to homogeneity from the denitrifying fungus Fusarium oxysporum. The purified protein existed as a monomer with a molecular weight of 44 kDa. It was purified in an oxidized form and exhibited the absorption maxima at 401, 540 and 643 nm in its resting form, and at 434 and 555 nm upon reduction with dithionite, respectively. The protein contained 0.5 mol protoheme/mol and 1.1 mol FAD/mol, respectively. When the resting flavohemoprotein was aerobically incubated with NAD(P)H, it was converted to a spectral species that is spectrally very similar to oxyhemoglobins. These properties are characteristics of flavohemoglobins (FHb) of Alcaligenes eutrophus, Escherichia coli, and baker's yeast. Further the amino terminal amino acid sequence of the protein of F. oxysporum was similar to those of these FHbs. These results suggest that the isolated flavohemoprotein of F. oxysporum would be a counterpart of the proteins in the FHb family.
Fatty acid‐promoted mitochondrial permeability transition by membrane depolarization and binding to the ADP/ATP carrier
Authors: Schönfeld Peter , Bohnensack Ralf
Published: July 2002

The mechanism by which non‐esterified long‐chain fatty acids (FFA) promote mitochondrial permeability transition (MPT) is not clear. We examined with energized rat liver mitochondria the role of two possible actions of FFA in MPT, (i) the reduction of the transmembrane potential (Δψ) and (ii) the increase of the negative surface charge of the inner mitochondrial membrane [Broekemeier, K.M. and Pfeiffer, D.G., Biochemistry 43, (1995) 16440–16449]. It was found that the ability of FFA to stimulate large amplitude swelling is clearly related to their uncoupling activity. Moreover, compared with classical protonophores (FCCP) FFA increase the sensitivity of the pore opening process to Δψ changes. In addition, FFA interact like their thioester derivatives in a structure‐dependent manner with the ADP/ATP carrier (measured as inhibition of [3H]atractyloside binding to the AAC protein). It is suggested that not only the protonophoric action of FFA, but also a presumable stabilization of the `cytosolic' conformation of AAC contribute to the FFA‐promoted MPT.
Protein binding regions of the mRNAs for the 55 kDa tumor necrosis factor receptor and the glucose transporter 1: sequence homology and competition for cellular proteins
Authors: Kafert Sabine , Winzen Reinhard , Loos Anneke , Bollig Frank , Resch Klaus , Holtmann Helmut
Published: July 2002

Gene expression is influenced by mechanisms regulating mRNA degradation. Knowledge on regulatory RNA elements involved and on proteins interacting with them is still limited. A 33 nucleotide (nt) region of the 55 kDa tumor necrosis factor receptor (TNFR‐55) mRNA, previously reported by us to engage in such interaction with proteins from U‐937 cells, exhibits homology to a 38 nt regulatory region of the glucose transporter GLUT‐1 mRNA. Labeled RNA fragments comprising these two regions bind similar sets of proteins. Upon phorbol ester‐induced differentiation into macrophage‐like cells, protein binding to both fragments is changed similarly. Furthermore, both compete with each other for protein binding. This suggests that GLUT‐1 and TNFR‐55 RNA share a novel protein binding RNA motif involved in regulation of their half life.
The complete triphosphate moiety of non‐hydrolyzable substrate analogues is required for a conformational shift of the flexible C‐terminus in E. coli dUTP pyrophosphatase
Authors: Vertessy Beata G , Larsson Gunilla , Persson Tina , Bergman Anna-Carin , Persson Rebecca , Nyman Per Olof
Published: July 2002

The molecular mechanism of substrate analogue interaction with Escherichia coli dUTPase was investigated, using the non‐hydrolyzable 2′‐deoxyuridine 5′‐(α,β‐imido)triphosphate (α,β‐imido‐dUTP). Binding of this analogue induces a difference in the far UV circular dichroism (CD) spectrum arguing for a significant change in protein conformation. The spectral shift is strictly Mg2+‐dependent, does not appear with dUDP instead of α,β‐imido‐dUTP and is not elicited if the flexible C‐terminal arm is deleted from the protein by limited tryptic digestion. Involvement of the C‐terminal arm in α,β‐imido‐dUTP binding is consistent with the finding that this analogue protects against tryptic hydrolysis at Arg‐141. Near UV CD of ligand‐enzyme complexes reveals a characteristic difference in the microenvironments of enzyme‐bound dUDP and α,β‐imido‐dUTP, a difference not observable in C‐terminally truncated dUTPase. The results suggest that (i) closing of the active site during the catalytic cycle, through the movement of the C‐terminal arm, requires the presence of the complete triphosphate moiety of the substrate in complex with Mg2+, and (ii) after catalytic cleavage the active site pops open to facilitate product release.
The cytokine‐inducible zinc finger protein A20 inhibits IL‐1‐induced NF‐κB activation at the level of TRAF6
Authors: Heyninck Karen , Beyaert Rudi
Published: July 2002

The zinc finger protein A20 is encoded by an immediate early response gene whose expression is induced by different inflammatory stimuli, including interleukin‐1 (IL‐1). Gene induction by IL‐1 is mediated by activation of the transcription factor NF‐κB, and requires the signal adapter protein TRAF6. The latter interacts with the NF‐κB‐inducing kinase NIK, which is believed to be part of the IκB kinase complex. Expression of A20 potently inhibits IL‐1‐induced NF‐κB activation by an unknown mechanism. Inhibition of IL‐1‐induced NF‐κB activation was found to be mediated by the C‐terminal zinc finger‐containing domain of A20. More importantly, we present evidence that A20 interferes with IL‐1‐induced NF‐κB activation at the level of TRAF6, upstream of NIK. Moreover, A20 was shown to directly interact with TRAF6.
A leucine‐rich repeat protein of carrot that exhibits antifreeze activity
Authors: Meyer Knut , Keil Michael , Naldrett Michael J
Published: July 2002

A gene encoding an antifreeze protein (AFP) was isolated from carrot (Daucus carota) using sequence information derived from the purified protein. The carrot AFP is highly similar to the polygalacturonase inhibitor protein (PGIP) family of apoplastic plant leucine‐rich repeat (LRR) proteins. Expression of the AFP gene is rapidly induced by low temperatures. Furthermore, expression of the AFP gene in transgenic Arabidopsis thaliana plants leads to an accumulation of antifreeze activity. Our findings suggest that a new type of plant antifreeze protein has recently evolved from PGIPs.
Characterisation and PCR‐based detection of a CYP2A6 gene deletion found at a high frequency in a Chinese population
Authors: Oscarson Mikael , McLellan Roman A , Gullstén Harriet , Yue Qun-Ying , Lang Matti A , Luisa Bernal Maria , Sinues Blanca , Hirvonen Ari , Raunio Hannu , Pelkonen Olavi , Ingelman-Sundberg Magnus
Published: July 2002

Cytochrome P450 2A6 is an important human hepatic P450 which activates pre‐carcinogens, oxidises some drugs and constitutes the major nicotine C‐oxidase. In fact, results have been presented in the literature which suggested a relationship between the distribution of defective CYP2A6 alleles and smoking behaviour as well as cigarette consumption. In the present report, we describe the structure of a novel CYP2A locus where the whole CYP2A6 gene has been deleted, resulting in an abolished cytochrome P450 2A6‐dependent metabolism. The origin of this locus is apparently due to an unequal crossover event between the 3′‐flanking region of the CYP2A6 and CYP2A7 genes. A rapid PCR‐based method for the detection of the CYP2A6del allele was developed and the allele frequency was 15.1% among 96 Chinese subjects, but only 1.0% in Finns (n=100) and 0.5% in Spaniards (n=100). In the Chinese population, we did not detect any CYP2A6*2 alleles using an improved genotyping procedure, in contrast to the 11–20% previously reported. It is concluded that genotyping for the CYP2A6del allele is of great importance in studies correlating, for example, smoking behaviour, pre‐carcinogen activation or drug metabolism to the CYP2A6 genotype, in particular when oriental populations are investigated.
A novel form of rhodopsin kinase from chicken retina and pineal gland1
Authors: Zhao Xinyu , Yokoyama Kohei , Whitten Mark E. , Huang Jing , Gelb Michael H. , Palczewski Krzysztof
Published: July 2002

The G protein‐coupled receptor kinases (GRKs) are important enzymes in the desensitization of activated G protein‐coupled receptors (GPCR). Seven members of the GRK family have been identified to date. Among these enzymes, GRK1 is involved in phototransduction and is the most specialized kinase of the family. GRK1 phosphorylates photoactivated rhodopsin (Rho*), initiating steps in its deactivation. In this study, we found that chicken retina and pineal gland express a novel form of GRK that has sequence features characteristic of GRK1. However, unlike bovine GRK1 which is farnesylated, chicken GRK1 contains a consensus sequence for geranylgeranylation. Peptides corresponding to the C‐terminal sequence of chicken GRK1 are geranylgeranylated by a cytosolic extract of chicken liver. Based on results of molecular cloning and immunolocalization, it appears that both rod and cone photoreceptors express this novel GRK1. These data indicate a larger sequence diversity of photoreceptor GRKs than anticipated previously.
Refsum disease diagnostic marker phytanic acid alters the physical state of membrane proteins of liver mitochondria
Authors: Schönfeld Peter , Struy Heinz
Published: July 2002

Phytanic acid (3,7,11,15‐tetramethylhexadecanoic acid), a branched chain fatty acid accumulating in Refsum disease to high levels throughout the body, induces uncoupling of rat liver mitochondria similar to non‐branched fatty acids (e.g. palmitic acid), but the contribution of the ADP/ATP carrier or the aspartate/glutamate carrier in phytanic acid‐induced uncoupling is of minor importance. Possible deleterious effects of phytanic acid on membrane‐linked energy coupling processes were studied by ESR spectroscopy using rat liver mitochondria and a membrane preparation labeled with the lipid‐specific spin probe 5‐doxylstearic acid (5‐DSA) or the protein‐specific spin probe MAL‐TEMPO (4‐maleimido‐2,2,6,6‐tetramethyl‐piperidine‐1‐oxyl). The effects of phytanic acid on phospholipid molecular dynamics and on the physical state of membrane proteins were quantified by estimation of the order parameter or the ratio of the amplitudes of the weakly to strongly immobilized MAL‐TEMPO binding sites (W/S ratio), respectively. It was found, that phytanic acid (1) increased the mobility of phospholipid molecules (indicated by a decrease in the order parameter) and (2) altered the conformational state and/or the segmental mobility of membrane proteins (indicated by a drastic decrease in the W/S ratio). Unsaturated fatty acids with multiple cis‐double bonds (e.g. linolenic or arachidonic acid), but not non‐branched FFA (ranging from chain length C10:0 to C18:0), also decrease the W/S ratio. It is hypothesized that the interaction of phytanic acid with transmembrane proteins might stimulate the proton permeability through the mitochondrial inner membrane according to a mechanism, different to a protein‐supported fatty acid cycling.
Cloning and expression pattern of EPAS1 in the chicken embryo
Authors: Favier Judith , Kempf Hervé , Corvol Pierre , Gasc Jean-Marie
Published: July 2002

EPAS1 is a hypoxia‐inducible transcription factor, highly expressed in vasculature and recently shown to be necessary for catecholamine production during embryogenesis. We report here the cloning and detailed expression pattern of this factor in the chicken embryo. We show that chicken EPAS1 presents an overall identity of 76% with the human sequence and that it is strongly expressed in the blood vessel wall, mostly in endothelial cells, but also in vascular smooth muscle cells. Moreover, we report non‐vascular expression sites: liver, kidney, and, quite interestingly, cells of the sympathetic nervous system where EPAS1 is coexpressed with one of its putative target genes, the tyrosine hydroxylase. EPAS1 could therefore represent the link between the vascular system and the sympathetic nervous system, both sensitive to hypoxia.
Cellulosome‐like sequences in Archaeoglobus fulgidus: an enigmatic vestige of cohesin and dockerin domains
Authors: Bayer Edward A. , Coutinho Pedro M. , Henrissat Bernard
Published: July 2002

The distribution of cellulosomal cohesin domains among the sequences currently compiled in various sequence databases was investigated. Two cohesin domains were detected in two consecutive open reading frames (ORFs) of the recently sequenced genome of the archaeon Archaeoglobus fulgidus. Otherwise, no cohesin‐like sequence could be detected in organisms other than those of the Eubacteria. One of the A. fulgidus cohesin‐containing ORFs also harbored a dockerin domain, but the additional modular portions of both genes are undefined, both with respect to sequence homology and function. It is currently unclear what function(s) the putative cohesin and dockerin‐containing proteins play in the life cycle of this organism. In particular, since A. fulgidus contains no known glycosyl hydrolase gene, the presence of a cellulosome can be excluded. The results suggest that cohesin and dockerin signature sequences cannot be used alone for the definitive identification of cellulosomes in genomes.
Rapid repair of titanium particle‐induced osteolysis is dramatically reduced in aged mice
Authors: Kaar Scott G. , Ragab Ashraf A. , Kaye Sarah J. , Kilic B. Alper , Jinno Tetsuya , Goldberg Victor M. , Bi Yanming , Stewart Matthew C. , Carter John R. , Greenfield Edward M.
Published: July 2002

Aseptic loosening is the most common cause of orthopaedic implant failure. This process is thought to be due to osteolysis induced by implant‐derived wear particles. Teitelbaum and colleagues have recently developed a promising murine calvarial model of wear particle‐induced osteolysis. However, prior to this study, this model had only been assessed qualitatively. We now report a reproducible, quantitative version of the calvarial model of wear particle‐induced osteolysis, in which the extent of osteolysis (and repair) of entire parietal bones is assessed by histomorphometry of contact microradiographs. Using this model, we found that the osteolytic response is transient and rapidly repaired in one month old mice. The extent of osteolysis peaks 7 days after particle implantation and returns to baseline levels by 13 days. A similar amount of osteolysis and even more extensive repair is observed when particles are implanted repeatedly. In contrast, aged mice develop progressive osteolysis with no detectable repair. As a result, 26 month old mice have approximately 17‐fold more osteolysis than one month old mice 21 days after particle implantation. Skeletally mature, adult mice (4–16 months old) show an intermediate pattern of response. Osteolysis in these mice peaks at 7 days after particle implantation but it is repaired more slowly than in the one month old mice. Taken together, these results underscore the role of an imbalance between bone resorption and bone formation in the development of aseptic loosening and suggest that agents that stimulate bone formation maybe useful in prevention or treatment of aseptic loosening. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
The material properties of the bovine acetabular labrum
Authors: Ferguson S. J. , Bryant J. T. , Ito K.
Published: July 2002

The compressive and tensile material properties of the bovine acetabular labrum were measured. Confined compression testing was used to determine the aggregate compressive modulus and the permeability of the labrum. The compressive modulus of the labrum (0.157 ± 0.057 MPa) is comparable to that of the morphologically similar meniscus, and approximately one‐quarter to one‐half that of the adjoining acetabular cartilage. The permeability of the labrum (4.98 ± 3.43 × 10−16 m4/N s) was lower than that of the meniscus and cartilage, with a significantly higher resistance to interstitial fluid flow across the acetabular rim than along the rim. Specimens from the posterior and superior regions of the labrum were tested to failure in uniaxial tension. The maximum stress at failure (11.9 ± 6.1 MPa), maximum strain at failure (26.5 ± 7.6%) and tangent modulus (74.7 ± 44.3 MPa) were similar to those reported for the bovine meniscus, and to other tissues composed of highly oriented collagen fiber bundles. In tension, the labrum is much stiffer (10–15 × ) than the adjoining articular cartilage, and the posterior region of the labrum is significantly stiffer (45%) than the superior region. The labrum's low permeability may contribute to sealing of the hip joint. The high circumferential tensile stiffness of the labrum, together with its ring structure, reinforce the acetabular rim and may contribute to joint stability. © 2001 Orthopaedic Research Society. Punlished by Elsevier Science Ltd. All rights reserved.
Understanding national Stalinism: reflections on Ceauşescu's socialism
Authors: Tismaneanu Vladimir
Published: July 2002

Of all the revolutions that took place during the annus mirabilis 1989, only the Romanian one was violent. The paper explores the sources of the Romanian different path, the extraordinary vitality of the authoritarian mentalities and practices in that country, the commingling of Leninist and Byzantine traditions in a uniquely cynical and manipulative formation. This may explain why, despite the ostensible radicalism and strong-worded, overblown rhetoric of the revolutionary paragons, the Leninist heritage in Romania has turned out to be more persistent and resilient than in other countries.
Twenty‐five years of corporate governance research … and counting
Authors: Denis Diane K
Published: July 2002

In this paper, the field of corporate governance in the US from the perspective of financial economists is reviewed. It begins with a discussion of the fundamental agency problem from which that field emanates, which is the separation between the owners (the shareholders) and the controllers (the managers) of the modern public corporation. Relying primarily on survey papers, the current evidence on the various mechanisms that have been proposed as potential solutions to this agency problem is then reviewed. The contributions made by the other three papers that comprise this Special Issue on Corporate Governance are also highlighted. Finally, suggestions—my own and those of others—regarding the direction of future corporate governance research are offered.
Umbilical Cord Clamping: Beliefs And Practices Of American Nurse‐Midwives
Authors: Mercer Judith S. , Nelson Carlene C. , Skovgaard Rebecca L.
Published: July 2002

The optimal time for umbilical cord clamping after birth remains a critical unknown fact that has implications for the infant, the mother, and science. A national survey was conducted using a randomized sample (n = 303) of the active membership of the ACNM to determine cord clamping practices and beliefs of American nurse‐midwives. The response rate was 56%. The respondents fell into three cord clamping categories: early (EC) or before 1 minute (26%); intermediate (IC) or 1 to 3 minutes (35%); and late (LC) or after pulsations cease (33%). The EC group believes that early clamping facilitates management of the newborn. The IC group believes that a moderate delay of clamping allows for a gradual transition to extrauterine circulation, although many think that the timing of cord clamping is not significant. The LC group have strongly held beliefs that late clamping supports physiologic birth processes. The majority of CNMs (87%) place the baby on the mother's abdomen immediately after birth and 96% avoid clamping a nuchal cord whenever possible. Although Varney's Midwifery was cited most frequently as a reference, 78% of the respondents listed no references reflecting, in part, the absence of evidence‐based recommendations for cord clamping practices.
PLACENTAL TRIAGE OF THE SINGLETON PLACENTA
Authors: Schuler‐Maloney Doris
Published: July 2002

Triage is the sorting and allocation of treatment according to a system of priorities in order to maximize treatment. Placental triage promptly after delivery of the placenta, with documentation of the findings in the medical record, only takes a few minutes, and allows for the identification of abnormal placentas to be submitted for detailed gross and microscopic pathology examination. It requires familiarity with normal gross placental anatomy and variations of normal, and the development of a systematic procedure for comprehensive examination of the placental disk as a whole, the umbilical cord, the extraplacental membranes, the fetal surface, the maternal surface, and the parenchyma. This article provides a systematic approach to gross examination of the placenta. It also reviews the clinical and legal impact of placenta examination, and suggests procedures that will optimize the information available in the placenta.
Commissioning of optical surface imaging systems for cranial frameless stereotactic radiosurgery
Authors: Zhang Lei , Vijayan Sarath , Huang Sheng , Song Yulin , Li Tianfang , Li Xiang , Hipp Elizabeth , Chan Maria F. , Kuo Hsiang‐Chi , Tang Xiaoli , Tang Grace , Lim Seng Boh , Lovelock Dale Michael , Ballangrud Ase , Li Guang
Published: March 2021

Purpose

This study aimed to evaluate and compare different system calibration methods from a large cohort of systems to establish a commissioning procedure for surface‐guided frameless cranial stereotactic radiosurgery (SRS) with intrafractional motion monitoring and gating. Using optical surface imaging (OSI) to guide non‐coplanar SRS treatments, the determination of OSI couch‐angle dependency, baseline drift, and gated‐delivered‐dose equivalency are essential.

Methods

Eleven trained physicists evaluated 17 OSI systems at nine clinical centers within our institution. Three calibration methods were examined, including 1‐level (2D), 2‐level plate (3D) calibration for both surface image reconstruction and isocenter determination, and cube phantom calibration to assess OSI‐megavoltage (MV) isocenter concordance. After each calibration, a couch‐angle dependency error was measured as the maximum registration error within the couch rotation range. A head phantom was immobilized on the treatment couch and the isocenter was set in the middle of the brain, marked with the room lasers. An on‐site reference image was acquired at couch zero, the facial region of interest (ROI) was defined, and static verification images were captured every 10° for 0°–90° and 360°–270°. The baseline drift was assessed with real‐time monitoring of the motionless phantom over 20 min. The gated‐delivered‐dose equivalency was assessed using the electron portal imaging device and gamma test (1%/1mm) in reference to non‐gated delivery.

Results

The maximum couch‐angle dependency error occurs in longitudinal and lateral directions and is reduced significantly (P < 0.05) from 1‐level (1.3 ± 0.4 mm) to 2‐level (0.8 ± 0.3 mm) calibration. The MV cube calibration does not further reduce the couch‐angle dependency error (0.8 ± 0.2 mm) on average. The baseline drift error plateaus at 0.3 ± 0.1 mm after 10 min. The gated‐delivered‐dose equivalency has a >98% gamma‐test passing rate.

Conclusion

A commissioning method is recommended using the 3D plate calibration, which is verified by radiation isocenter and validated with couch‐angle dependency, baseline drift, and gated‐delivered‐dose equivalency tests. This method characterizes OSI uncertainties, ensuring motion‐monitoring accuracy for SRS treatments.
Detection and Management of Interstitial Lung Diseases Associated With Connective Tissue Diseases
Authors: Castelino Flavia V. , Moua Teng
Published: March 2021

Interstitial lung disease (ILD) is a common manifestation of connective tissue diseases (CTDs). A proportion of patients with CTD‐ILDs develop progressive fibrosing ILD, which is characterized by worsening fibrotic abnormalities on high‐resolution computed tomography scan, decline in lung function, worsening symptoms, and early mortality. Here, we review the impact of ILD in patients with CTDs, the importance of prompt diagnosis and close monitoring, and the evidence available to guide the management of CTD‐ILDs. Management of patients with CTD‐ILDs should be individualized and involve close collaboration between rheumatologists and pulmonologists. Immunosuppression is the mainstay of therapy for CTDs, but evidence for its effectiveness in slowing the progression of ILD is limited. Recently, nintedanib has been approved to slow decline in lung function in patients with systemic sclerosis–associated ILD and chronic fibrosing ILDs with a progressive phenotype. The results of ongoing clinical trials will help clinicians take a more evidence‐based approach to the treatment of CTD‐ILDs.
Total Synthesis of (−)‐Arborisidine
Authors: Wang Feng‐Yuan , Jiao Lei
Published: March 2021

An asymmetric total synthesis of cage‐like indole alkaloid arborisidine is presented. The new synthetic strategy features a catalytic parallel kinetic resolution based on ambident nucleophilicity (C3/N) of indole to set the absolute configurations of the two quaternary chiral centers, and a 5‐exo‐trig radical cyclization to form the bridged nitrogen‐containing five‐membered ring.
High Pressure In Situ Single‐Crystal X‐Ray Diffraction Reveals Turnstile Linker Rotation Upon Room‐Temperature Stepped Uptake of Alkanes
Authors: van Heerden Dewald P. , Smith Vincent J. , Aggarwal Himanshu , Barbour Leonard J.
Published: March 2021

The rare availability of suitable single‐crystal X‐ray diffraction (SCXRD) structural data allows for the direct interpretation of the response of a framework to gas sorption and may lead to the development of improved functional porous materials. We report an in situ SCXRD structural investigation of a flexible MOF subjected to methane, ethane, propane, and butane gas pressures. Supporting theoretical investigations indicate weak host–guest interactions for the crystallographically modelled gaseous guests and, in addition, reveal that a turnstile mechanism facilitates the transport of alkanes through the seemingly nonporous system. Inflections present in the adsorption isotherms are furthermore rationalized as due to gate‐opening, but without the expected creation of new accessible space.
An Electrically Conducting Three‐Dimensional Iron–Catecholate Porous Framework
Authors: Mähringer Andre , Döblinger Markus , Hennemann Matthias , Gruber Christoph , Fehn Dominik , Scheurle Patricia I. , Hosseini Pouya , Santourian Irina , Schirmacher Alfred , Rotter Julian M. , Wittstock Gunther , Meyer Karsten , Clark Timothy , Bein Thomas , Medina Dana D.
Published: March 2021

We report the synthesis of a unique cubic metal–organic framework (MOF), Fe‐HHTP‐MOF, comprising hexahydroxytriphenylene (HHTP) supertetrahedral units and FeIII ions, arranged in a diamond topology. The MOF is synthesized under solvothermal conditions, yielding a highly crystalline, deep black powder, with crystallites of 300–500 nm size and tetrahedral morphology. Nitrogen sorption analysis indicates a highly porous material with a surface area exceeding 1400 m2 g−1. Furthermore, Fe‐HHTP‐MOF shows broadband absorption from 475 up to 1900 nm with excellent absorption capability of 98.5 % of the incoming light over the visible spectral region. Electrical conductivity measurements of pressed pellets reveal a high intrinsic electrical conductivity of up to 10−3 S cm−1. Quantum mechanical calculations predict Fe‐HHTP‐MOF to be an efficient electron conductor, exhibiting continuous charge‐carrier pathways throughout the structure.
Cyclotetrabenzoin Acetate: A Macrocyclic Porous Molecular Crystal for CO2 Separations by Pressure Swing Adsorption**
Authors: Wang Yao‐Ting , McHale Corie , Wang Xiqu , Chang Chung‐Kai , Chuang Yu‐Chun , Kaveevivitchai Watchareeya , Miljanić Ognjen Š. , Chen Teng‐Hao
Published: March 2021

A porous molecular crystal (PMC) assembled by macrocyclic cyclotetrabenzoin acetate is an efficient adsorbent for CO2 separations. The 7.1×7.1 Å square pore of PMC and its ester C=O groups play important roles in improving its affinity for CO2 molecules. The benzene walls of macrocycle engage in an apparent [π⋅⋅⋅π] interaction with the molecule of CO2 at low pressure. In addition, the polar carbonyl groups pointing inward the square channels reduce the size of aperture to a 5.0×5.0 Å square, which offers kinetic selectivity for CO2 capture. The PMC features water tolerance and high structural stability under vacuum and various gas adsorption conditions, which are rare among intrinsically porous organic molecules. Most importantly, the moderate adsorbate‐adsorbent interaction allows the PMC to be readily regenerated, and therefore applied to pressure swing adsorption processes. The eluted N2 and CH4 are obtained with over 99.9 % and 99.8 % purity, respectively, and the separation performance is stable for 30 cycles. Coupled with its easy synthesis, cyclotetrabenzoin acetate is a promising adsorbent for CO2 separations from flue and natural gases.
Stereoselective Sc(OTf)3‐Catalyzed Aldol Reactions of Disubstituted Silyl Enol Ethers of Aldehydes with Acetals
Authors: Wang Peter‐Yong , Massad Itai , Marek Ilan
Published: March 2021

Facile and modular access to stereodefined disubstituted aldehyde‐derived silyl enol ethers allowed their successful application in a stereoselective aldol reaction affording the products with excellent yields and diastereomeric ratios. The counter‐intuitive stereochemical behavior of this Mukaiyama‐aldol reaction is accounted for by a non‐classical open transition state.
A Low‐Strain Potassium‐Rich Prussian Blue Analogue Cathode for High Power Potassium‐Ion Batteries
Authors: Li Lin , Hu Zhe , Lu Yong , Wang Chenchen , Zhang Qiu , Zhao Shuo , Peng Jian , Zhang Kai , Chou Shu‐Lei , Chen Jun
Published: March 2021

Most of the cathode materials for potassium ion batteries (PIBs) suffer from poor structural stability due to the large ionic radius of K+, resulting in poor cycling stability. Here we report a low‐strain potassium‐rich K1.84Ni[Fe(CN)6]0.88⋅0.49 H2O (KNiHCF) as a cathode material for PIBs. The as‐prepared KNiHCF cathode can deliver reversible discharge capacity of 62.8 mAh g−1 at 100 mA g−1, with a high discharge voltage of 3.82 V. It can also achieve a superior rate performance of 45.8 mAh g−1 at 5000 mA g−1, with a capacity retention of 88.6 % after 100 cycles. The superior performance of KNiHCF cathode results from low‐strain de‐/intercalation mechanism, intrinsic semiconductor property and low potassium diffusion energy barrier. The high power density and long‐term stability of KNiHCF//graphite full cell confirmed the feasibility of K‐rich KNiHCF cathode in PIBs. This work provides guidance to develop Prussian blue analogues as cathode materials for PIBs.
Awake tracheal intubation with the ProVu™ video stylet: a case series*
Authors: Harrison S‐L. , Ahmad I. , Elwen F. , Curtis A. , Dua G. , Surda P. , Johnstone C.
Published: March 2021

Management of the difficult airway is integral to peri‐operative practice. The development of devices to simplify airway handling are changing our approach to tracheal intubation. We report a case series of three patients who underwent awake tracheal intubation with the ProVu™ video stylet (Flexicare Medical Ltd, Mountain Ash, UK). All three patients had predicted difficult airways, including: limited mouth opening secondary to radiotherapy; previous exenteration, hemi‐maxillectomy and scapular free flap formation; and cervical fixation. Awake tracheal intubation was performed successfully in all three cases, with no complications reported. This is the first reported case series of the ProVu™ video stylet as an awake tracheal intubation device. The benefits and limitations of this video stylet are discussed.
Design and synthesis of ferrocene‐tethered pyrazolines and pyrazoles: Photophysical studies, protein‐binding behavior with bovine serum albumin, and antiproliferative activity against MDA‐MB‐231 triple negative breast cancer cells
Authors: Ghosh Koena , Nayek Nipa , Das Subhomoy , Biswas Nabendu , Sinha Samraj
Published: March 2021

We report synthesis and characterization of a series of ferrocene‐pyrazoline and pyrazole hybrids and demonstrate their biomedical applications. All new compounds were identified with the help of spectroscopic techniques and single‐crystal X‐ray analysis. The compounds from both the series show fluorescent activity. The effect of C5 aryl substituent on the luminescent behavior of the parent system was followed by studying their absorption and emission behavior. The binding affinity of a selected ferrocenyl pyrazoline with C5 2‐naphthyl substituent (4g) to bovine serum albumin (BSA) was examined through fluorescence quenching experiments using excitation wavelength 290 nm. The ligand 4g quenched the intrinsic fluorescence of BSA. Strong binding between 4g and BSA was observed with equilibrium constant for the complex formation of the order of 105 M‐1. In vitro anticancer activity of a series of ferrocenyl‐pyrazolines and pyrazoles (4f, 4g, 4h, 5f, 5g, and 5h) was tested against hormone‐independent triple negative breast cancer cells MDA‐MB‐231 in which maximum inhibition potency was noted for 4h with IC50 value of 3.61 mg ml−1.
A Two‐dimensional Amorphous Plasmonic Heterostructure of Pd/MoO3‐x for Enhanced Photoelectrochemical Water Splitting Performance
Authors: Liu Wei , Tian Qingyong , Yang Jian , Zhou Yannan , Chang Hongwei , Cui Wenhui , Xu Qun
Published: March 2021

Two‐dimensional (2D) heterostructures based on localized surface plasmon resonance (LSPR) have a great potential for solar energy harvesting applications. Exploring 2D amorphous plasmonic heterostructures with high light absorption and catalytic activity is desirable yet challenging. Herein, 2D Pd/MoO3‐x amorphous heterostructures can be obtained by immobilizing Pd single atoms in unsaturated coordination sites of amorphous MoO3‐x, because of strong metal‐support interactions, and it reaches a current density of 50 μA cm−2 for photoelectrochemical response with good durability, and exhibits a high incident‐photon‐to‐current‐conversion efficiency (IPCE) of 14.8% at 460 nm. Such an enhanced catalytic effects are contributed to the enhanced light absorption in visible region and change of electronic structure owing to enhanced electron transfer through dominant Pd−O bonds, which facilitate water splitting. This work moves a step closer to the expansion of photovoltaic device with the high conversion efficiency for visible light for amorphous heterostructures.
Relative contributions of environmental factors on different time scales to tropical cyclogenesis over the eastern North Pacific
Authors: Cao Xi , Wu Renguang , Feng Juan , Zhang Xiping , Dai Yifeng
Published: March 2021

The present study investigates relative contributions of large‐scale environmental factors on interannual, intraseasonal, and synoptic time scales to tropical cyclone (TC) genesis over the eastern North Pacific (ENP) during TC seasons of 1979–2013 from the perspective of TC genesis time and position. Conditional sorting displays that the synoptic component is more important in the contribution of lower‐level vorticity and mid‐level specific humidity to TC genesis compared to interannual and intraseasonal components. The convection contributes to TC genesis mainly through synoptic and intraseasonal components. Synoptic‐scale tropical disturbances mainly obtain barotropic eddy energy from climatological mean flows. TCs appear most frequently when vertical wind shear anomalies are between 0 and 3 m s−1, in which interannual and intraseasonal westerly wind anomalies make a positive contribution due to climatological easterly wind shear. When total SST exceeds 28°C, the interannual component of sea surface temperature (SST) is positive, and then it has a positive contribution to TC genesis. In addition, there are notable differences of relative contributions of different time scale components of large‐scale factors among the ENP, northern Atlantic Ocean, and western North Pacific.
Limited surface examination to evaluate potential teratogens in a resource‐limited setting
Authors: Holmes Lewis B. , Nasri Hanah Z. , Hunt Anne‐Therese , Zash Rebecca , Shapiro Roger L.
Published: March 2021

Background

To determine the frequency of malformations that would be identified in the limited surface examination of a newborn by the delivering nurse midwife in a resource‐limited setting.

Methods

The limited surface examination will identify visible external anomalies, but not abnormalities inside the mouth, most heart defects, undescended testes, inguinal hernias, hip dysplasia, peripheral vascular anomalies, and some internal anomalies. The findings in a malformations surveillance program, involving 289,365 births in Boston, have been used to establish the prevalence rate of malformations that would be identified and not identified. In African countries, the number of anomalies to be identified should also be reduced by excluding polydactyly, postaxial, type B, a common minor finding, from the list of potential malformations.

Results

Of note, 2.05% (n = 5,941) of the 289,365 births surveyed had one or more malformations. The abnormalities that would have been missed, using surface exam alone, accounted for 0.5% of all of malformations identified and reduced the overall prevalence rate of malformations to 1.5%. In addition, excluding all infants with isolated postaxial polydactyly, type B reduced the expected prevalence rate of malformations to 1.3% in unexposed newborn infants.

Conclusion

A limited surface examination can detect the majority of malformations among newborn infants.
The rehabilitation of verbal operants following acquired brain injury
Authors: Magat Kimberly A. , Heinicke Megan R. , Buckley Dani L.
Published: March 2021

Although verbal deficits are major concerns for individuals following an acquired brain injury (ABI), behavior‐analytic research on language training in neurorehabilitation settings is extremely limited. The purpose of the current study was to systematically replicate the work of Sundberg et al. (1990) in which the authors evaluated the acquisition and functional interdependence of verbal operants for adults following ABI. We used slightly modified procedures (e.g., inclusion of high preference activities, progressive prompt delay) and compared acquisition rates of tacts, mands, and intraverbals with three adult ABI survivors. We also assessed if directly training one verbal operant led to the emergence of untrained, topographically similar verbal operants. Contrary to Sundberg et al., we found mand training was successful for all participants and led to the greatest amount of transfer under tact conditions, and we offer potential explanations for our differing results.
Mismatch detection in homologous strand exchange amplified by hydrophobic effects
Authors: Nordén Bengt , Brown Tom , Feng Bobo
Published: March 2021

In contrast to DNA replication and transcription where nucleotides are added and matched one by one, homologous recombination by DNA strand exchange tests whole sequences for complementarity, which requires elimination of mismatched yet thermodynamically stable intermediates. To understand the remarkable sequence specificity of homologous recombination, we have studied strand exchange between a 20‐mer duplex containing one single mismatch (placed at varied positions) with the matching single strand in presence of poly(ethylene glycol) representing a semi‐hydrophobic environment. A FRET‐based assay shows that rates and yields of strand exchange from mismatched to matched strands rapidly increase with semi‐hydrophobic co‐solute concentration, contrasting previously observed general strand exchange accelerating effect of ethyl glycol ethers. We argue that this effect is not caused simply by DNA melting or solvent‐induced changes of DNA conformation but is more complex involving several mechanisms. The catalytic effects, we propose, involve strand invasion facilitated by reduced duplex stability due to weakened base stacking (“longitudinal breathing”). Secondly, decreased water activity makes base‐pair hydrogen bonds stronger, increasing the relative energy penalty per mismatch. Finally, unstacked mismatched bases (gaps) are stabilized through partly intercalated hydrophobic co‐solvent molecules, assisting nucleation of strand invasion at the point of mismatch. We speculate that nature long ago discovered, and now exploits in various enzymes, that sequence recognition power of nucleic acids may be modulated in a hydrophobic environment.
Synthetic Approaches to 2‐Alkylthiochroman‐4‐ones and Thioflavanones
Authors: In Lee Jae
Published: March 2021

2‐Alkylthiochroman‐4‐ones have been synthesized by acid‐catalyzed cyclodehydration of 3‐alkyl‐3‐(phenylthio)propanoic acids, Friedel–Crafts acylation of 3‐alkyl‐3‐(phenylthio)propanoyl chlorides with Lewis acids, direct reaction of thiophenols and acrylic acids using CF3SO3H, and 1,4‐addition of organometallic reagents to thiochromones. Furthermore, thioflavanones have been synthesized by cyclization of 3‐phenyl‐3‐(phenylthio)propanoyl chlorides with Lewis acids, incorporation of sulfur atoms into 2'‐halochalcones and subsequent cycloelimination, 1,4‐addition of S‐protected chalcones, direct condensation of 2'‐mercaptoacetophenone with arylaldehydes using lithium diisopropylamide, conjugate addition of organometallic reagents to thiochromones, and hydrogenation of thioflavones.
Comparison of the investigational device exemption and post‐approval trials of the Melody transcatheter pulmonary valve
Authors: Kreutzer Jacqueline , Armstrong Aimee K. , Rome Jonathan J. , Zellers Thomas M. , Balzer David T. , Zampi Jeffrey D. , Cabalka Allison K. , Javois Alexander J. , Turner Daniel R. , Gray Robert G. , Moore John W. , Weng Shicheng , Jones Thomas K. , Khan Danyal M. , Vincent Julie A. , Hellenbrand William E. , Cheatham John P. , Bergersen Lisa J. , McElhinney Doff B.
Published: March 2021

Objective

We compared 5‐year outcomes of transcatheter pulmonary valve (TPV) replacement with the Melody TPV in the post‐approval study (PAS) and the investigational device exemption (IDE) trial.

Background

As a condition of approval of the Melody TPV after the IDE trial, the Food and Drug Administration required that a PAS be conducted to evaluate outcomes of TPV replacement in a “real‐world” environment. The 5‐year outcomes of the PAS have not been published, and the IDE and PAS trials have not been compared.

Methods

The cohorts comprised all patients catheterized and implanted at 5 IDE sites and 10 PAS sites. Differences in trial protocols were detailed. Time‐related outcomes and valve‐related adverse events were compared between the two trials with Kaplan–Meier curves and log‐rank testing.

Results

167 patients (median age, 19 years) were catheterized and 150 underwent TPV replacement in the IDE trial; 121 were catheterized (median age, 17 years) and 100 implanted in the PAS. Freedom from hemodynamic dysfunction (p = .61) or any reintervention (p = .74) over time did not differ between trials. Freedom from stent fracture (p = .003) and transcatheter reintervention (p = .010) were longer in PAS, whereas freedom from explant (p = .020) and TPV endocarditis (p = .007) were shorter. Clinically important adverse events (AEs) were reported in 14% of PAS and 7.2% of IDE patients (p = .056); the incidence of any particular event was low in both.

Conclusions

Hemodynamic and time‐related outcomes in the PAS and IDE trials were generally similar, confirming the effectiveness of the Melody TPV with real‐world providers. There were few significant complications and limited power to identify important differences in AEs. The lack of major differences in outcomes between the two studies questions the usefulness of mandated costly post‐approval studies as part of the regulatory process for Class III medical devices.
Modified BLUE protocol ultrasonography can diagnose thrombotic complications of COVID‐19 with normal lung ultrasound
Authors: Zaalouk Tamer Mohamed , Bitar Zouheir Ibrahim , Maadarani Ossama Sajeh , Ragab Elshabasy Ragab Desouky
Published: March 2021

The BLUE protocol provides an excellent step‐by‐step approach for diagnosis of acute dyspnea. Adding FECHO (Focused Echocardiography) to the BLUE protocol completes the picture and helps make solid diagnoses, especially in submassive and massive PE (Pulmonary embolism). COVID‐19 infection can present with thrombotic manifestations like DVT (Deep vein thrombosis) and PE with no ultrasonographic evidence of lung parenchymal affection.
Aortic valve replacement in a patient with sickle cell disease—Are we justified to perform surgery in the TAVI era?
Authors: Ravishankar Ramanish , Turkistani Leenah , Elghoneimy Yasser , Manoly Imthiaz
Published: March 2021

Not all variants of SCD need the same management and this should be decided on a case‐by‐case basis. Heterozygous SCD patients can undergo cardiac surgery without the need for intraoperative exchange transfusions with good clinical outcomes.