bluuebunny/crossref_metadata_2025 huggingface dataset:
Observation of mobile poly(β‐hydroxybutyrate) in the storage granules of Methylobacterium AM1 by in vivo 13C‐NMR spectroscopy
Authors: Barnard Glenn N. , Sanders Jeremy K.M.
Published: July 2002

13C‐NMR spectra of whole native cells of Methylobacterium AM1 show dominant signals belonging to poly(β‐hydroxybutyrate) and trehalose. Fractionation of the cells demonstrates that the poly(β‐hydroxybutyrate) is located in the storage granules and that the trehalose is located in the cytosol. The observation of relatively sharp poly(β‐hydroxybutyrate) signals indicates that the polymer granule in this organism is in a mobile rather than truly solid state in vivo.
Effect of calcium and temperature on mixed lipid‐valinomycin monolayers A comparison of glycosphingolipids (ganglioside GT1b, sulphatides) and phosphatidylcholine
Authors: Schifferer Florian , Beitinger Heinz , Rahmann Hinrich , Möbius Dietmar
Published: July 2002

The influence of calcium and temperature on pure lipid (bovine brain PC, sulphatides, ganglioside GT1b), valinomycin and mixed lipid‐valinomycin monolayers at the air/water interface was studied. In mixed films, evidence was found that the two components were miscible. On the other hand, at higher surface pressures, phase separation occurs in the cases of PC and sulphatides. Measuring the area requirement and the collapse pressure the stability of both lipid and the peptide was increased in particular due to ganglioside‐valinomycin interaction. The addition of 10−5 M calcium into the subphase at 20 and 37°C and surface pressures of 10 and 20 mN/m led to a condensing effect in ganglioside mixtures, with formation of aggregates as indicated also by the nearly ideal behaviour of two component monolayers.
Muramyl peptides bind specifically to rat brain membranes
Authors: Kaydalov A.A. , Utkin Yu.N. , Andronova T.M. , Tsetlin V.I. , Ivanov V.T.
Published: July 2002

The capability of immunoactive muramyl peptides to bind specifically to rat brain membranes has been discovered. The reaction of an N‐acetylglucosaminylmuramyl dipeptide analog having an additional C‐terminal lysine residue (GMDP‐Lys) with Bolton‐Hunter reagent or N‐hydroxysuccinimidyl‐4‐azidosalicylate afforded two acylated derivatives, GMDP‐Lys‐(Hp) and GMDP‐Lys(Azs). Their iodination resulted in radioactive derivatives (spec. act. ∼2000 Ci/mmol) whose binding to rat brain membranes is characterized by K
d∼3 nM and B
max∼10 fmol/mg membrane protein. Binding could be inhibited by muramyl dipeptide (MDP), GMDP‐Lys, and GMDP, while fragments of the latter, N‐acetylglucosamine, dipeptide and disaccharide, were ineffective.
Platelet‐activating factor (PAF) acts as an intercellular messenger in the changes of cytosolic free Ca2+ in human neutrophils induced by opsonized particles
Authors: Tool Anton T.J. , Verhoeven Arthur J. , Roos Dirk , Koenderman Leo
Published: July 2002

Additon of opsonized particles to human neutrophils in suspension leads to a biphasic elevation in the cytosolic free Ca2+ concentration ([Ca2+]i). The rise in [Ca2+]i, during the second phase (> 3 min) is pronounced (about 400 nM), in contrast to the rise during the first phase, which is relatively small (< 100 nM). The second and large rise in [Ca2+]i is brought about by messenger(s) released from the cell after addition of opsonized particles. This second rise in [Ca2+]i, is not observed in the presence of the platelet‐activating factor (PAF) antagonist WEB 2086, indicating that PAF can act as an intercellular messenger affecting Ca2+ homeostasis in human neutrophils.
Luminol enhanced chemiluminescence of the perfused rat heart during ischemia and reperfusion
Authors: Kumar C. , Okuda M. , Ikai I. , Chance B.
Published: July 2002

We show that the production of Luminol reactive oxygen radicals in the perfused rat heart under ischemia and reperfusion can be monitored continuously by measuring the chemiluminescence of Luminol‐perfused hearts. Luminol did not affect the monitored physiological parameters of the hearts. Chemiluminescence increased during ischemia and reperfusion. Superoxide dismutase treatment of the heart before ischemia, but not catalase, abolished these increases.
Atropine dissociates complexes of muscarinic acetylcholine receptor and guanine nucleotide‐binding protein in heart membranes
Authors: Matesic Diane F. , Luthin Gary R.
Published: July 2002

Complexes of muscarinic acetylcholine receptor and guanine nucleotide‐binding protein (G protein) are formed in the presence of the agonist carbachol. The complexes remain stable after removal of agonist, and survive subsequent solubilization from cardiac membranes and purification. Dissociation of the receptor from the G protein occurs when the antagonist atropine is added following removal of agonist. This is the first direct demonstration of destabilization of receptor—G protein complexes by the binding of an antagonist.
Identification of the metal coordinating residues in the DNA binding domain of the glucocorticoid receptor by 113Cd‐1H heteronuclear NMR spectroscopy
Authors: Kellenbach E. , Maler B.A. , Yamamoto K.R. , Boelens R. , Kaptein R.
Published: July 2002

Two‐dimensional 1H‐113Cd HSQC and relay HSQC experiments were performed on the 113Cd substituted DNA binding domain of the rat glucocorticoid receptor. The results of these experiments combined with sequence‐specific assignments allowed the identification of all coordinating cysteines.It was found that C495 and not C500 is the fourth coordinating cysteine in the second zinc‐finger. A signal at ∼2 ppm previously assigned to a ε‐CH3 of a methionine residue coordinating to a third, weakly bound, cadmium ion, was identified as the C443 β proton ligating to the metal ion in the first zinc‐finger. No indications were found for the presence of a previously suggested third metal ion binding site.
Anoxic injury accelerates phosphatidylcholine degradation in cultured cardiac myocytes by phospholipase C
Authors: Nachas Nabil , Pinson Arié
Published: July 2002

In neonatal cultured cardiac myocytes under normoxic conditions, 32Pi incorporation pattern into various phospholipids, and double‐labeling experiments with 32Pi and [3H]methyl choline, suggest that phosphatidylcholine atid phosphatidylinositol are turned over rapidly, whereas the turnover of phosphatidylethanolamine is probably much slower. While increased levels of the corresponding lysophospholipids were not found under anoxia, release of diacylgycerol and phosphorylcholine was observed. These data strongly suggest that phospholipase C, and not phospholipase A2, is involved in phospholipid degradation in cultured cardiomyocytes under anoxic conditions.
Molecular cloning and functional expression of rat leukotriene A4hydrolase using the polymerase chain reaction
Authors: Makitala Naomasa , Funku Colin D. , Imaic Enyu , Hoover Richard L. , Badra Kamal F.
Published: July 2002

We isolated a cDNA encoding rat leukotriene A4 (LTA4) hydrolase from mesangial cells by the polymerase chain reaction according to the human amino acid sequence. The deduced amino acid sequence shows that rat LTA, hydrolase is a 609 amino acid protein with an M, 69 kDa. Comparison of human LTA4 hydrolase revealed 93% homology, and include zinc‐binding motifs of aminopeptidases. COS‐7 cells transfected with the cDNA revealed substantial LTA4 hydrolase activity, and their activities were abolished by preincubation with captopril, representing the first reported cDNA expression of recombinant enzyme in mammalian cells. RNA blot analysis indicated that LTA4 hydrolase was expressed in glomerular endothelial, epithelial and mesangial cells.
Direct kinetics of bait region cleavage of α‐2‐macroglobulin by a rapid quenching method
Authors: Shibuya Nozomu , Ikai Atsushi
Published: July 2002

The rate of bait region cleavage of human α‐2‐macroglobulin by chymotrypsin was determined by a rapid quenching method under conditions where the bimolecular encounter between the two reactants was not rate‐limiting. α2M was first mixed with a 30 molar excess of chymotrypsin in a sequential stopped‐flow apparatus and after programmed time intervals the activity of chymotrypsin was quenched with 1 N HCl. The fraction of uncleaved subunits was quantitated by SDS‐PAGE under reducing conditions. The result indicated that the bait region cleavage proceeded following a two‐exponential decay curve with respective rate constants of k
1 = 40 s−1 and k
2 = 2 s−1.
Effects of Ca2+ on the activation of conventional and new PKC isozymes and on TPA and endothelin‐1 induced translocations of these isozymes in intact cells
Authors: Chen Ching-Chow
Published: July 2002

The effects of Ca2+ on the translocation of conventional and new protein kinase C isozymes in intact cells were studied by using C6 glioma cells as a model system. Two conditions which monitor intracellular Ca2+ were performed: one is extracellular Ca2+‐depletion by treating the cells with physiological saline solution (PSS) without Ca2+ but containing 0.5 mM EGTA, the other is treating the cells with 1 μM ionomycin to induce Ca2+‐influx. In addition, the TPA and endothelin‐1 induced translocations of conventional and new PKC isozymes under these two conditions were also comparatively studied. When the intact cells were treated with Ca2+‐free, EGTA containing PSS, the membrane‐bound conventional PKCα (cPKCα) was greatly reduced and cytosolic cPKCα was slightly increased. However, neither membrane bound nor cytosolic new PKCδ (nPKCδ) was affected by extracellular Ca2+‐depletion. On the other hand, when the cells were treated with 1 μM ionomycin, the translocation of cPKCα itself was observed while nPKCδ was not affected. In extracellular Ca2+‐depletion, the translocation of cPKCα induced by 100 nM TPA still occurred although the extent of translocation was smaller than that induced by TPA under normal Ca2+ conditions; however, that induced by 30 nM ET‐1 was blocked. After the cells were treated with 1 μM ionomycin, the translocation of cPKCα induced by 30 nM TPA was further increased compared to 1 μM ionomycin or 30 nM TPA alone, while that induced by ET‐1 was only slightly further increased. All these results suggested that in intact cells, the activation of cPKCα was operated by both the intracellular Ca2+ level and diacylglycerol and that of nPKCδ was operated by diacylglycerol alone as predicted by their properties from purified enzyme or cDNA. In addition, the translocation of cPKCα induced by the natural activator ET‐1 seemed to be more dependent on Ca2+ than TPA in intact cells.
The third exoplasmic loop of the thyrotropin receptor is partially involved in signal transduction
Authors: Kosugi Shinji , Mori Toru
Published: July 2002

We characterized the role of the three exoplasmic loops in the transmembrane region of the thyrotropin receptor (TSHR) by substituting each loop with the counterpart of β2‐adrenergic receptor amino acid sequence. Mutant El3 with a substitution of the 3rd exoplasmic loop showed significant decrease in the maximal level and sensitivity of TSH‐stimulated cAMP response despite good retention of TSH binding. These findings suggest that the third exoplasmic loop of the TSH receptor is partially involved in the signal transduction mechanism.
The oligomerization domain of p53: Crystal structure of the trigonal form
Authors: Miller Maria , Lubkowski Jacek , Mohana Rao J.K. , Danishefsky Avis T. , Omichinski James G. , Sakaguchi Kazuyasu , Sakamoto Hiroshi , Appella Ettore , Gronenborn Angela M. , Clore G.Marius
Published: July 2002

The structure of the oligomerization domain of the p53 tumor suppressor protein was determined in the trigonal crystal form, using a refined NMR structure as a model. A synthetic peptide comprising residues 319–360 of human p53 crystallized in the space group P3121. There is one biologically relevant tetrameric domain in the crystallographic asymmetric unit. The structure was refined jointly with NMR data, only the third such case (the previous examples being IL‐1β (Shaanan, B., Gronenborn,, A.M., Cohen, G.H., Gilliland, G.L., Veerapandian, B., Davies, D.R. and Clore, G.M. (1992) Science 257, 961–964 [1]) and BPTI (Schiffer, C., Huber, R., Wuthrich, K. and Van Gunsteren, W.F. (1994) J. Mol. Biol. 241, 588–599 [2])), to 2.5 Å resolution with an R factor of 0.207. The distribution of tumor‐derived mutations in the oligomerization region together with structural and biological data suggest a strategy for the design of antitumor therapeutics.
The chum salmon IGF‐II gene promoter is activated by hepatocyte nuclear factor 3β
Authors: Palamarchuk Alexey Y. , Kavsan Vadim M. , Sussenbach John S. , Holthuizen P.Elly
Published: July 2002

IGF‐II plays an important role in growth and development of vertebrates and is highly expressed in adult salmon liver. In the present study, we demonstrate that a liver‐enriched transcription factor, hepatocyte nuclear factor 3β (HNF‐3β), is an activator of the chum salmon IGF‐II gene. Multiple binding sites for HNF‐3β were identified within the 5′‐UTR using electrophoretic mobility shift assays and mutation of these sites prevents binding of HNF‐3β. In transient transfection assays it was shown that mutation of the HNF‐3β binding sites results in a substantial decrease of HNF‐3β‐activated salmon IGF‐II gene expression. This is the first identified transcription factor that is functionally involved in the regulation of fish IGF‐II expression.
Oral or vaginal misoprostol for induction of labor
Authors: Toppozada M.K. , Anwar M.Y.M. , Hassan H.A. , El‐Gazaerly W.S.
Published: July 2002

Objective: To compare vaginal versus oral misoprostol for induction of labor. Method: Induction of labor was carried out in 40 women near term in two equal and randomized groups (according to a computer generated table) using misoprostol. Group I received vaginal misoprostol (100 μg) every 3 h while group II patients were given the same dose via the oral route. The dose was doubled if no response was detected under continuous cardiotocographic (CTG) tracings. Result: The vaginal route of administration induced a higher success rate in a shorter time interval using a lower dose but was associated with more abnormal FHR patterns and instances of uterine hyperstimulation. Conclusion: It is recommended to use the vaginal approach with cardiotocographic monitoring.
Characterization and distribution of extracellular matrix components and receptors in GH3B6 prolactin cells
Authors: de Carvalho Daniela F. , Silva Karina L. , de Oliveira Désio A.F , Villa‐Verde Déa Maria S. , Coelho Hamilton S. , Silva Luiz‐Cláudio F. , Nasciutti Luiz E.
Published: July 2002

GH3B6 cells, a rat pituitary tumor cell line, synthesize and secrete large amounts of prolactin (PRL) in vitro. In the present work, we evaluated the capacity of these cells to express extracellular matrix (ECM) components and receptors in vitro. The expression of laminin (LN), fibronectin (FN) and type IV collagen (CIV) was investigated by immunofluorescence assays. In comparison to PRL distribution, where around 50–70 % of the cells contained PRL concentrated in the Golgi region, a variable immunolabeling for the three ECM components could be observed in the majority of GH3B6 cells. Importantly, this pattern was not modified when cells were cultured in the presence of 30 nM thyroliberin (TRH). The expression of the ECM receptors: α5β1 (FN receptor), α6β1 (LN receptor) and CD44 (hyaluronic acid receptor) could be demonstrated by cytofluorometric analysis. Using biochemical procedures, we analyzed the synthesis and secretion of glycosaminoglycans (GAGs). The cells synthesized and secreted mainly heparan sulfate (75 %) with a minor amount of chondroitin sulfate/dermatan sulfate. In an attempt to evaluate the individual contribution of the ECM components to influence cell morphology and PRL distribution in vitro, GH3B6 cells were cultivated separately on LN, FN and CIV substrates. Under all conditions, it was possible to observe an increase of cell adherence to the substrate, accompanied with changes of cellular morphology, characterized by the appearance of cytoplasmatic processes. However, no changes on PRL distribution could be observed. Our results suggest that endocrine tumor cell lines are involved in synthesis of ECM components and receptors.
Cholinesterases modulate cell adhesion in human neuroblastoma cells in vitro
Authors: Johnson Glynis , Moore Samuel W.
Published: July 2002

Cholinesterases are expressed non‐synaptically during embryonic development, neoplasia and neurodegeneration. We have investigated the effects of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) and, conversely, anti‐AChE and ‐BChE antibodies and inhibitors on cell adhesion and neurite outgrowth in human neuroblastoma cells. Analysis of cholinesterase levels and isoforms in undifferentiated and differentiated cells indicated a significant rise in AChE levels on differentiation. This increase was related to both cell‐associated and secreted enzyme, and was predominantly the G4 isoform. BChE levels and isoforms, on the other hand, showed no significant variation. Coating the tissue culture plate with AChE stimulated neurite outgrowth, while BChE had an anti‐adhesive effect. Cell adhesion was affected by the BChE inhibitor, ethopropazine, and the AChE peripheral site inhibitor, BW284c51, but not by eserine which binds to the active site. This indicates that the adhesion function is non‐cholinergic, a finding supported by the lack of effect of AE‐2, a monoclonal antibody that inhibits AChE, on cell adhesion. Four out of a panel of nine anti‐AChE antibodies inhibited adhesion to varying degrees. Of these antibodies, two are catalytic, with epitopes associated with the peripheral anionic site of AChE, and the remaining two have epitopes overlapping this site. Neither of the two anti‐BChE antibodies used had any effect on adhesion. These results indicate the importance of AChE in neuroblastoma cell adhesion and neurite outgrowth, and suggest that the peripheral anionic site may be involved in these processes.
The distribution of radiolabeled corticotropin‐releasing factor in pregnant rats : an investigation of placental transfer to the FETUSES
Authors: Williams Michael T. , Davis Harry N. , Mccrea Anne E. , Hennessy Michael B.
Published: July 2002

Stress during gestation can have serious consequences on the development of the fetus. Many of these effects appear to be mediated by hormones of the hypothalamic‐pituitary‐adrenal (HPA) axis. Corticotropin‐releasing factor (CRF), released by the hypothalamus during times of stress serves to activate release of pituitary hormones and is also present in low levels in rat plasma. Moreover, the uterus contains significant quantities of CRF at implantation sites, probably from local sources. Therefore, the possibility exists that CRF may cross the placenta and activate the fetal HPA axis. However, the ability of CRF to cross the placenta has not been demonstrated. In the present study, pregnant rats were administered radiolabeled CRF intraperitoneally, and the distribution of the labeled product was determined in the fetuses and various maternal organs. High levels of activity were observed in the pregnant females uterus, adrenals, heart and the placentae, but only background levels of activity were detected in the maternal brain. Very low levels of activity were observed in the fetuses, indicating that the transfer of CRF across the placenta is greatly restricted. These findings suggest that maternal CRF has little or no direct effect on the developing fetus during gestational stress.
Consequences of Recent Changes in Research and Practice for the Identity of Psychiatrists
Authors: Guimón J
Published: July 2002

The limits of the role of psychiatrists are becoming increasingly vague as a consequence of the confusion on the theoretical model, the excessive size of the field and the managed care movement that is deeply altering the way psychiatric services are delivered. A thorough reflection has to be made about the need to strengthen the professional identity of future psychiatrists in the course of their training. Theoretical orientation of psychiatrists depends, to a large extent, on the training that they received during residency and the type of practice they undertake. It is necessary, therefore, to consider that the institutional path and expected activities in the program of training postgraduates is particularly important for the development of the identity of the resident as a psychiatrist. The criteria for elaborating these programs have to take into account, not only the opinion of the teachers and of the residents, but also many other parameters, one of which is the description of what makes a true psychiatrist in his or her clinical practice, so as to adapt the content of programs to the realization of inherent objectives to the activities described.
A Micromolding Method for Transparent and Flexible Thin‐Film Supercapacitors and Hybrid Supercapacitors
Authors: Liu Tian , Yan Runyu , Huang Haijian , Pan Long , Cao Xiaobao , deMello Andrew , Niederberger Markus
Published: September 2020

Thin‐film supercapacitors are promising candidates for energy storage in wearable electronics due to their mechanical flexibility, high power density, long cycling life, and fast‐charging capability. In addition to all of these features, device transparency would open up completely new opportunities in wearable devices, virtual reality or in heads‐up displays for vehicle navigation. Here a method is introduced for micromolding Ag/porous carbon and Ag/NixFeyOz@reduced graphene oxide (rGO) into grid‐like patterns on polyethylene terephthalate foils to produce transparent thin‐film supercapacitors and hybrid supercapacitors. The supercapacitor delivers a high areal capacitance of 226.8 µF cm−2 at a current density of 3 µA cm−2 and with a transparency of 70.6%. The cycling stability is preserved even after 1000 cycles under intense bending. A hybrid supercapacitor is additionally fabricated by integrating two electrodes of Ag/porous carbon and Ag/NixFeyOz@rGO. It offers an areal capacitance of 282.1 µF cm−2 at a current density of 3 µA cm−2, a transparency of 73.3% and the areal capacitance only decreases slightly under bending. This work indicates that micromolding of nano‐ and micro‐sized powders represents a powerful method for preparing regular electrode patterns, which are fundamental for the development of transparent energy storage devices.
Isomerization Strategy of Nonfullerene Small‐Molecule Acceptors for Organic Solar Cells
Authors: Luo Zhenghui , Liu Tao , Yan He , Zou Yang , Yang Chuluo
Published: September 2020

Nonfullerene acceptors (NFAs) are a current focus of research on bulk‐heterojunction organic solar cells (OSCs), as they can exhibit strong absorption, suitably matched energy levels, and good stability. Isomerization affords a new material design strategy for nonfullerene small‐molecule acceptors (SMAs). In this article, the development of isomeric nonfullerene SMAs, including isomeric perylene diimide (PDI)‐based nonfullerene SMAs and isomeric acceptor–donor–acceptor (A–D–A)‐type nonfullerene SMAs, is reviewed. The general design principles for isomeric SMAs and the key structure–property relationships are comprehensively surveyed and discussed. The remaining challenges and promising future directions of isomeric nonfullerene acceptors are presented.
Dual Coordination of Ti and Pb Using Bilinkable Ligands Improves Perovskite Solar Cell Performance and Stability
Authors: Tan Furui , Saidaminov Makhsud I. , Tan Hairen , Fan James Z. , Wang Yuhang , Yue Shizhong , Wang Xiaotian , Shen Zhitao , Li Shengjun , Kim Junhwan , Gao Yueyue , Yue Gentian , Liu Rong , Huang Ziru , Dong Chen , Hu Xiaodong , Zhang Weifeng , Wang Zhijie , Qu Shengchun , Wang Zhanguo , Sargent Edward H.
Published: September 2020

Charge recombination due to interfacial defects is an important source of loss in perovskite solar cells. Here, a two‐sided passivation strategy is implemented by incorporating a bilinker molecule, thiophene‐based carboxylic acid (TCA), which passivates defects on both the perovskite side and the TiO2 side of the electron‐extracting heterojunction in perovskite solar cells. Density functional theory and ultrafast charge dynamics reveal a 50% reduction in charge recombination at this interface. Perovskite solar cells made using TCA‐passivated heterojunctions achieve a power conversion efficiency of 21.2% compared to 19.8% for control cells. The TCA‐containing cells retain 96% of initial efficiency following 50 h of UV‐filtered MPP testing.
Sequential Protein Capture in Multiplex Single Molecule Arrays: A Strategy for Eliminating Assay Cross‐Reactivity
Authors: Gilboa Tal , Maley Adam M. , Ogata Alana F. , Wu Connie , Walt David R.
Published: September 2020

Measurements of multiple biomolecules within the same biological sample are important for many clinical applications to enable accurate disease diagnosis or classification. These disease‐related biomarkers often exist at very low levels in biological fluids, necessitating ultrasensitive measurement methods. Single‐molecule arrays (Simoa), a bead‐based digital enzyme‐linked immunosorbent assay, is the current state of the art for ultrasensitive protein detection and can detect sub‐femtomolar protein concentrations, but its ability to achieve high‐order multiplexing without cross‐reactivity remains a challenge. Here, a sequential protein capture approach for multiplex Simoa assays is implemented to eliminate cross‐reactivity between binding reagents by sequentially capturing each protein analyte and then incubating each capture bead with only its corresponding detection antibody. This strategy not only reduces cross‐reactivity to background levels and significantly improves measurement accuracies, but also enables higher‐order multiplexing. As a proof of concept, the sequential multiplex Simoa assay is used to measure five different cytokines in plasma samples from Coronavirus Disease 2019 (COVID‐19) patients. The ultrasensitive sequential multiplex Simoa assays will enable the simultaneous measurements of multiple low‐abundance analytes in a time‐ and cost‐effective manner and will prove especially critical in many cases where sample volumes are limited.
One‐shot video‐based person re‐identification with variance subsampling algorithm
Authors: Zhao Jing , Yang Wenjing , Yang Mingliang , Huang Wanrong , Yang Qiong , Zhang Hongguang
Published: September 2020

Previous works propose the distance‐based sampling for unlabeled datapoints to address the few‐shot person re‐identification task, however, many selected samples may be assigned with wrong labels due to poor feature quality in these works, which negatively affects the learning procedure. In this article, we propose a novel sampling strategy to improve the quality of assigned pseudo‐labels, thus promoting the final performance. To illustrate, we first propose the concept of variance confidence to measure the credibility of pseudo‐labels, then we apply a novel variance subsampling algorithm to improve the accuracy of the selected sample labels. Our method combines distance confidence and variance confidence as a two‐round sampling criterion. Meanwhile, a variation decay strategy is used in our sampling process in combination with the actual distribution of features. We evaluate our approach on two publicly available datasets, MARS and DukeMTMC‐VideoReID, and achieve state‐of‐the‐art one‐shot performance.
Design procedure for planar slotted waveguide antenna arrays with controllable sidelobe level ratio for high power microwave applications
Authors: El Misilmani Hilal M. , Al‐Husseini Mohammed , Kabalan Karim Y.
Published: September 2020

This article presents a complete design procedure for planar slotted waveguide antennas (SWA). For a desired sidelobe level ratio (SLR), the proposed method provides a pencil shape pattern with a narrow half power beamwidth, which makes the proposed system suitable for high power microwave applications. The proposed planar SWA is composed of only two layers, and uses longitudinal coupling slots rather than the conventional inclined coupling slots. For a desired SLR, the slots excitation in the radiating and feeder SWAs are calculated based on a specified distribution. Simplified closed‐form equations are then used to determine the slots nonuniform displacements, for both the radiating and feeder SWAs, without the need to use optimization algorithms. Using simplified equations, the slots lengths, widths, and their distribution along the length of the radiating and feeder SWAs can be found. The feeder dimensions and slots positions are deduced from the dimensions and total number of the radiating SWAs. An 8 × 8 planar SWA has been designed and tested to show the validity of the proposed method. The obtained measured and simulated results are in accordance with the design objectives.
Exploitability prediction of software vulnerabilities
Authors: Bhatt Navneet , Anand Adarsh , Yadavalli V. S. S.
Published: September 2020

The number of security failure discovered and disclosed publicly are increasing at a pace like never before. Wherein, a small fraction of vulnerabilities encountered in the operational phase are exploited in the wild. It is difficult to find vulnerabilities during the early stages of software development cycle, as security aspects are often not known adequately. To counter these security implications, firms usually provide patches such that these security flaws are not exploited. It is a daunting task for a security manager to prioritize patches for vulnerabilities that are likely to be exploitable. This paper fills this gap by applying different machine learning techniques to classify the vulnerabilities based on previous exploit‐history. Our work indicates that various vulnerability characteristics such as severity, type of vulnerabilities, different software configurations, and vulnerability scoring parameters are important features to be considered in judging an exploit. Using such methods, it is possible to predict exploit‐prone vulnerabilities with an accuracy >85%. Finally, with this experiment, we conclude that supervised machine learning approach can be a useful technique in predicting exploit‐prone vulnerabilities.
Synthesis, Characterization, and Electrocatalytic Behavior for Hydrogen Evolution of a Dinuclear Copper(II) Complex of 1‐[(2‐Carboxymethyl) benzene]‐3‐[2‐carboxybenzene] triazene
Authors: Xie Zhen‐Lang , Liu Wei‐Xia , Wang Nan‐Shu , Zhan Shu‐Zhong
Published: September 2020

A dinuclear copper(II) complex, [CuII2(L)2] is afforded by the reaction of CuCl2·2H2O with a triazenido ligand, 1‐[(2‐carboxymethyl) benzene]‐3‐[2‐carboxybenzene] triazene (H2L). Structural investigation shows that the copper‐copper distance [2.3985(7) Å] is significantly shorter than the sum of the van der Waals radii of Cu (1.40 Å), suggesting that there are metal‐metal bonds in [CuII2(L)2]. In solid, there is a strong antiferromagnetic interaction between copper(II) ions (J = –135.6 cm–1). In homogeneous environment, [CuII2(L)2] shows electrocatalytic activities for hydrogen generation both from acetic acid with a turnover frequency (TOF) of 32 mol of hydrogen per mole of catalyst per hour [mol(H2)·mol–1(catalyst)·h–1] at an overpotential (OP) of 941.6 mV, and neutral buffer with a TOF of 512 mol(H2)·mol–1(catalyst)·h–1 at an OP of 836.7 mV.
Literacy Toy for Enhancement Phonological Awareness: A Longitudinal Study
Authors: Ramos-Galarza Carlos , Arias-Flores Hugo , Cóndor-Herrera Omar , Jadán-Guerrero Janio
Published: September 2020

In this report it is presented the results of a longitudinal pre-experimental study, it was realized a technological intervention to stimulate the phonological awareness through a tangible reading toy based on the RFID technology, consisting of a teddy bear and 30 letters in 3D from the Spanish alphabet. This study started with a sample of 200 children, from them, there were selected 17 children aged between 6 and 7 years (Mage = 6.47, SD = .51) with a phonological disorder from an educative institution. The procedure consisted of obtaining pre-test and post-test values with the Evaluation of Phonological Awareness (PECFO). Sampling inclusion criteria considered children presenting problems of phonemes’ recognition and its relationship with graphemes. During 30 weeks it was realized an intervention with the technological toy and at the end of the sessions, it was applied the post-test. Results of phonological awareness showed statically significant differences among the pre (M = 12.88, SD = 3.53) and post-test (M = 17.17, SD = 2.96) this contributes to the empirical evidence of the intervened group improvement in this cognitive function t(16) = −3.67, p = .002. From this research it is projected proposing technological innovations contributing in the treatment of children’s cognitive difficulties.
$$ T\overline{T} $$
, black holes and negative strings
Authors: Chakraborty Soumangsu , Giveon Amit , Kutasov David
Published: September 2020

Abstract

String theory on AdS3 has a solvable single-trace irrelevant deformation that is closely related to $$ T\overline{T} $$
T

T
¯

. For one sign of the coupling, it leads to an asymptotically linear dilaton spacetime, and a corresponding Hagedorn spectrum. For the other, the resulting spacetime has a curvature singularity at a finite radial location, and an upper bound on the energies of states. Beyond the singularity, the signature of spacetime is flipped and there is an asymptotically linear dilaton boundary at infinity. We study the properties of black holes and fundamental strings in this spacetime, and find a sensible picture. The singularity does not give rise to a hard ultraviolet wall for excitations -one must include the region beyond it to understand the theory. The size of black holes diverges as their energy approaches the upper bound, as does the location of the singularity. Fundamental strings pass smoothly through the singularity, but if their energy is above the upper bound, their trajectories are singular. From the point of view of the boundary at infinity, this background can be thought of as a vacuum of Little String Theory which contains a large number of negative strings.
Derivative couplings in gravitational production in the early universe
Authors: Borrajo Gutiérrez Daniel E. , Cembranos Jose A.R. , Garay Luis J. , Sánchez Velázquez Jose M.
Published: September 2020

Abstract

Gravitational particle production in the early universe is due to the coupling of matter fields to curvature. This coupling may include derivative terms that modify the kinetic term. The most general first order action contains derivative couplings to the curvature scalar and to the traceless Ricci tensor, which can be dominant in the case of (pseudo-)Nambu-Goldstone bosons or disformal scalars, such as branons. In the presence of these derivative couplings, the density of produced particles for the adiabatic regime in the de Sitter phase (which mimics inflation) is constant in time and decays with the inverse effective mass (which in turn depends on the coupling to the curvature scalar). In the reheating phase following inflation, the presence of derivative couplings to the background curvature modifies in a nontrivial way the gravitational production even in the perturbative regime. We also show that the two couplings — to the curvature scalar and to the traceless Ricci tensor — are drastically different, specially for large masses. In this regime, the production becomes highly sensitive to the former coupling while it becomes independent of the latter.
Causality, poetics, and grammatology: the role of computation in machine seeing
Authors: Emsley Iain
Published: September 2020

Digitised collections and born digital items, such as photos or video, exist beyond the scale of human viewing. New methods are required to read, understand and work with the data, resulting in computation becoming increasingly central to both creation of a cultural reality and as the interpretative tool and practice. If artists’ look, then how might a machine see as a critical tool? Developing work on computational culture and the Next Rembrandt project as unstable digital object, this paper considers how the medium affects computational critical practice. Drawing on Heidegger’s view of causality and Derrida’s grammatology, this paper explores how the medium acts a locus between the human and machine readings and the remediations that occur within the reading. This is developed as through a reading of how the interface translates the signs and symbols and how this affects the reading. By reconsidering the critical assemblage and using it to think with, the human and the machine are seen as critical partners. Attending to the materialities of the reading through a playful approach that decentres potential meaning encourages us to glimpse beneath the surface and gestures towards a critical practice as understanding both computation and its materiality.
A simple layout optimization formulation for load-carrying tensegrity structures
Authors: Nanayakkara K. I. U. , He Linwei , Fairclough Helen E. , Gilbert Matthew
Published: September 2020

Traditional tensegrity structures comprise isolated compression members lying inside a continuous network of tension members. In this contribution, a simple numerical layout optimization formulation is presented and used to identify the topologies of minimum volume tensegrity structures designed to carry external applied loads. Binary variables and associated constraints are used to limit (usually to one) the number of compressive elements connecting a node. A computationally efficient two-stage procedure employing mixed integer linear programming (MILP) is used to identify structures capable of carrying both externally applied loads and the self-stresses present when these loads are removed. Although tensegrity structures are often regarded as inherently ‘optimal’, the presence of additional constraints in the optimization formulation means that they can never be more optimal than traditional, non-tensegrity, structures. The proposed procedure is programmed in a MATLAB script (available for download) and a range of examples are used to demonstrate the efficacy of the approach presented.
Chatter model for enabling a digital twin in machining
Authors: Afazov Shukri , Scrimieri Daniele
Published: September 2020

This paper presents the development of a new chatter model using measured cutting forces instead of a mathematical model with empirical nature that describes them. The utilisation of measured cutting forces enables the prediction of real-time chatter conditions and stable machining. The chatter model is validated using fast Fourier transform (FFT) analyses for detection of chatter. The key contribution of the developed chatter model is that it can be incorporated in digital twins for process monitoring and control in order to achieve greater material removal rates and improved surface quality in future industrial applications involving machining processes.
Use of in vitro bone models to screen for altered bone metabolism, osteopathies, and fracture healing: challenges of complex models
Authors: Ehnert Sabrina , Rinderknecht Helen , Aspera-Werz Romina H. , Häussling Victor , Nussler Andreas K.
Published: September 2020

Approx. every third hospitalized patient in Europe suffers from musculoskeletal injuries or diseases. Up to 20% of these patients need costly surgical revisions after delayed or impaired fracture healing. Reasons for this are the severity of the trauma, individual factors, e.g, the patients’ age, individual lifestyle, chronic diseases, medication, and, over 70 diseases that negatively affect the bone quality. To investigate the various disease constellations and/or develop new treatment strategies, many in vivo, ex vivo, and in vitro models can be applied. Analyzing these various models more closely, it is obvious that many of them have limits and/or restrictions. Undoubtedly, in vivo models most completely represent the biological situation. Besides possible species-specific differences, ethical concerns may question the use of in vivo models especially for large screening approaches. Challenging whether ex vivo or in vitro bone models can be used as an adequate replacement for such screenings, we here summarize the advantages and challenges of frequently used ex vivo and in vitro bone models to study disturbed bone metabolism and fracture healing. Using own examples, we discuss the common challenge of cell-specific normalization of data obtained from more complex in vitro models as one example of the analytical limits which lower the full potential of these complex model systems.
Radiation exposure of computed tomography imaging for the assessment of acute stroke
Authors: Zensen Sebastian , Guberina Nika , Opitz Marcel , Köhrmann Martin , Deuschl Cornelius , Forsting Michael , Wetter Axel , Bos Denise
Published: September 2020

Purpose

To assess suspected acute stroke, the computed tomography (CT) protocol contains a non-contrast CT (NCCT), a CT angiography (CTA), and a CT perfusion (CTP). Due to assumably high radiation doses of the complete protocol, the aim of this study is to examine radiation exposure and to establish diagnostic reference levels (DRLs).

Methods

In this retrospective study, dose data of 921 patients with initial CT imaging for suspected acute stroke and dose monitoring with a DICOM header–based tracking and monitoring software were analyzed. Between June 2017 and January 2020, 1655 CT scans were included, which were performed on three different modern multi-slice CT scanners, including 921 NCCT, 465 CTA, and 269 CTP scans. Radiation exposure was reported for CT dose index (CTDIvol) and dose-length product (DLP). DRLs were set at the 75th percentile of dose distribution.

Results

DRLs were assessed for each step (CTDIvol/DLP): NCCT 33.9 mGy/527.8 mGy cm and CTA 13.7 mGy/478.3 mGy cm. Radiation exposure of CTP was invariable and depended on CT device and its protocol settings with CTDIvol 124.9–258.2 mGy and DLP 1852.6–3044.3 mGy cm.

Conclusion

Performing complementary CT techniques such as CTA and CTP for the assessment of acute stroke increases total radiation exposure. Hence, the revised DRLs for the complete protocol are required, where our local DRLs may help as benchmarks.
Image-guided in situ detection of bacterial biofilms in a human prosthetic knee infection model: a feasibility study for clinical diagnosis of prosthetic joint infections
Authors: Schoenmakers Jorrit W. A. , Heuker Marjolein , López-Álvarez Marina , Nagengast Wouter B. , van Dam Gooitzen M. , van Dijl Jan Maarten , Jutte Paul C. , van Oosten Marleen
Published: September 2020

Purpose

Due to an increased human life expectancy, the need to replace arthritic or dysfunctional joints by prosthetics is higher than ever before. Prosthetic joints are unfortunately inherently susceptible to bacterial infection accompanied by biofilm formation. Accurate and rapid diagnosis is vital to increase therapeutic success. Yet, established diagnostic modalities cannot directly detect bacterial biofilms on prostheses. Therefore, the present study was aimed at investigating whether arthroscopic optical imaging can accurately detect bacterial biofilms on prosthetic joints.

Methods

Here, we applied a conjugate of the antibiotic vancomycin and the near-infrared fluorophore IRDye800CW, in short vanco-800CW, in combination with arthroscopic optical imaging to target and visualize biofilms on infected prostheses.

Results

We show in a human post-mortem prosthetic knee infection model that a staphylococcal biofilm is accurately detected in real time and distinguished from sterile sections in high resolution. In addition, we demonstrate that biofilms associated with the clinically most relevant bacterial species can be detected using vanco-800CW.

Conclusion

The presented image-guided arthroscopic approach provides direct visual diagnostic information and facilitates immediate appropriate treatment selection.
Varied functions of immune checkpoints during cancer metastasis
Authors: Safarzadeh Ali , Alizadeh Mohsen , Beyranvand Fatemeh , Falavand Jozaaee Reza , Hajiasgharzadeh Khalil , Baghbanzadeh Amir , Derakhshani Afshin , Argentiero Antonella , Baradaran Behzad , Silvestris Nicola
Published: September 2020

Immune checkpoints comprise diverse receptors and ligands including costimulatory and inhibitory molecules, which play monumental roles in regulating the immune system. Immune checkpoints retain key potentials in maintaining the immune system homeostasis and hindering the malignancy development and autoimmunity. The expression of inhibitory immune checkpoints delineates an increase in a plethora of metastatic tumors and the inhibition of these immune checkpoints can be followed by promising results. On the other hand, the stimulation of costimulatory immune checkpoints can restrain the metastasis originating from diverse tumors. From the review above, key findings emerged regarding potential functions of inhibitory and costimulatory immune checkpoints targeting the metastatic cascade and point towards novel potential Achilles’ heels of cancer that might be exploited therapeutically in the future.
Accuracy of controlled attenuation parameter compared with ultrasound for detecting hepatic steatosis in children with severe obesity
Authors: Runge Jurgen H. , van Giessen Jet , Draijer Laura G. , Deurloo Eline E. , Smets Anne M. J. B. , Benninga Marc A. , Koot Bart G. P. , Stoker Jaap
Published: September 2020

Objectives

To determine the diagnostic accuracy of controlled attenuation parameter (CAP) on FibroScan® in detecting and grading steatosis in a screening setting and perform a head-to-head comparison with conventional B-mode ultrasound.

Methods

Sixty children with severe obesity (median BMI z-score 3.37; median age 13.7 years) were evaluated. All underwent CAP and US using a standardized scoring system. Magnetic resonance spectroscopy proton density fat fraction (MRS-PDFF) was used as a reference standard.

Results

Steatosis was present in 36/60 (60%) children. The areas under the ROC (AUROC) of CAP for the detection of grade ≥ S1, ≥ S2, and ≥ S3 steatosis were 0.80 (95% CI: 0.67–0.89), 0.77 (95% CI: 0.65–0.87), and 0.79 (95% CI: 0.66–0.88), respectively. The AUROC of US for the detection of grade ≥ S1 steatosis was 0.68 (95% CI: 0.55–0.80) and not significantly different from that of CAP (p = 0.09). For detecting ≥ S1 steatosis, using the optimal cutoffs, CAP (277 dB/m) and US (US steatosis score ≥ 2) had a sensitivity of 75% and 61% and a specificity of 75% and 71%, respectively. When using echogenicity of liver parenchyma as only the scoring item, US had a sensitivity of 70% and specificity of 46% to detect ≥ S1 steatosis. The difference in specificity of CAP and US when using only echogenicity of liver parenchyma of 29% was significant (p = 0.04).

Conclusion

The overall performance of CAP is not significantly better than that of US in detecting steatosis in children with obesity, provided that the standardized scoring of US features is applied. When US is based on liver echogenicity only, CAP outperforms US in screening for any steatosis (≥ S1).

Key Points

• The areas under the ROC curves of CAP and ultrasound (US) for detecting grade ≥ S1 steatosis were 0.80 and 0.68, respectively, and were not significantly different (p = 0.09).

• For detecting grade ≥ S1 steatosis in severely obese children, CAP had a sensitivity of 75% and a specificity of 75% at its optimal cutoff value of 277 dB/m.

• For detecting grade ≥ S1 steatosis in clinical practice, both CAP and US can be used, provided that the standardized scoring of US images is used.