bluuebunny/crossref_metadata_2025 huggingface dataset:
An Antithrombin III Assay Based on Factor Xa Inhibition Provides a More Reliable Test to Identify Congenital Antithrombin III Deficiency Than an Assay Based on Thrombin Inhibition
Authors: Demers Christine , Henderson Penny , Blajchman Morris A , Wells Michael J , Mitchell Lesley , Johnston Marilyn , Ofosu Fred A , Fernandez-Rachubinski Franҫoise , Andrew Maureen , Hirsh Jack , Ginsberg Jeffrey S
Published: July 2018

Objectives: To determine whether functional antithrombin III (AT-III) levels measured by a factor Xa inhibition (AT-III-Xa) assay identifies AT-III deficient individuals more reliably than functional AT-III levels measured by a thrombin inhibition (AT-III-IIa) assay.

Study design: Cross-sectional study.

Patient population: Sixty-seven members of a large family with type 2 AT-III deficiency.

Intervention: DNA analysis was used as the reference diagnostic standard for AT-III status and subjects were classified as AT-III deficient or non deficient according to these results. Functional AT-III levels were measured in all subjects using: 1) a chromogenic substrate for thrombin and added human thrombin (AT-III-IIa), and 2) a chromogenic substrate for factor Xa and added bovine factor Xa (AT-III-Xa). Functional heparin cofactor II (HC-II) levels were measured using a commercially available kit. The proportions of 125I-α-thrombin complexed to AT-III and HC-II were measured by polyacrylamide gel electrophoresis and autoradiography.

Results: Thirty-one (46%) individuals were classified as AT-III deficient and 36 (54%) as AT-III non deficient. AT-III-Xa assay measured a significantly lower mean AT-III value and a narrower range for individuals classified as AT-III deficient than the AT-III-IIa assay. Using the AT-III-IIa assay, six subjects had borderline AT-III levels compared to none with the AT-III-Xa assay. Thrombin inhibition by HC-II likely accounts for the AT-III-IIa assay giving higher values than the AT-III-Xa assay since 1) there was a significant correlation between the difference in AT-III-IIa and AT-III-Xa levels and HC-II levels, 2) the mean level of HC-II was significantly higher for individuals who had a positive difference between AT-III-IIa and AT-III-Xa levels compared to those who had a negative difference and 3) there was a significant correlation between the difference in AT-III-IIa and AT-III-Xa levels and the percentage of 125I-α-thrombin complexed to HC-II.

Conclusion: The AT-III-Xa assay is a better discriminant between AT-III deficient and AT-III non deficient individuals than the AT-III-IIa assay.
Antithrombotic Activity of SR 46349, a Novel, Potent and Selective 5-HT2 Receptor Antagonist
Authors: Herbert J M , Bernat A , Barthelemy G , Dol F , Rinaldi M
Published: July 2018

SR 46349 (trans-4-[(3Z)3-(2-dimethylaminoethyl)oxyimino-3(2-fluorophenyl)propen-1-yl] phenol, hemifumarate) is the first member of a newly-developed 5-HT2 antagonist series. SR 46349 potently inhibited serotonin-induced aggregation of rabbit and human platelets (IC50 = 1 and 3.9 nM respectively) but had no effect on the action of other platelet aggregating agents. SR 46349 was 118 and 25 times more potent than ketanserin against 5-HT + epinephrine-induced aggregation of rabbit and human platelets respectively.

A single per os administration of SR 46349 (1 mg/kg) resulted in a strong inhibition of 5-HT + epinephrine-induced platelet aggregation in the rabbit as measured ex vivo (67% inhibition, 6 h after the administration). Intravenous or oral administration of SR 46346 inhibited in a dose-dependent manner venous thrombosis induced by ligature of the jugular vein of rabbits whose blood was made hypercoagulable by i.v. administration of tissue thromboplastin. The doses of SR 46349 which inhibited 50% of thrombus formation were 1.5 ± 0.8 mg/kg and 17 ± 0.5 mg/kg after i.v. or oral administration respectively. When given i.v. to rabbits, SR 46349 exhibited a dose-dependent antithrombotic effect in an arterio-venous shunt model. Significant increase of the bleeding time was observed after the i.v. administration of 5 mg/kg of SR 46349 (3-fold increase). In dogs, SR 46349 inhibited cyclic coronary artery blood flow variations, complete abolition of CFVs being achieved after the i.v. administration of 0.5 mg/kg.

In conclusion, SR 46349 is a highly potent, selective antagonist of serotonin in vitro and is to be considered as a potent, orally active antithrombotic agent.
Retinoic Acid Enhances Fibrinolytic Activity In-Vivo by Enhancing Tissue Type Plasminogen Activator (t-PA) Activity and Inhibits Venous Thrombosis
Authors: van Giezen J J J , Boon G d I A , Jansen J W C M , Bouma B N
Published: July 2018

We studied the profibrinolytic effect and the anti-thrombotic potential of retinoic acid in-vivo. Male Wistar rats were treated with retinoic acid either acutely or twice daily for a period of 5 consecutive days in a dose range of 0.01 to 3.0 mg/kg. Fibrinolytic activity was measured ex-vivo using the diluted blood clot lysis test and net t-PA activity in tissue extracts was measured in a spectrophotometric rate assay. Clot lysis was dose dependently increased by retinoic acid up to about 170% (relative to vehicle treated rats) at a dose of 3 mg/kg. No tachyphylaxis could be detected. Ex-vivo measured fibrinolytic activity after single administration of 1 mg/kg of retinoic acid peaked at 3 h after ingestion. Even after 18 h a significantly higher clot lysis rate was measured. Lysis of blood clots from vehicle and retinoic acid treated rats could be completely blocked by addition of tranexamic acid or antibodies against rat t-PA before clot formation. t-PA activity in plasma was slightly increased after retinoic acid treatment; no effects were measured on plasma PAI-1, u-PA, plasminogen, and α2-antiplasmin levels. t-PA activity in lung and kidney was marginally enhanced by retinoic acid but in heart and aortic tissue extracts t-PA activity was increased by about 50%. We confirmed this potential anti-thrombotic property in an in-vivo venous thrombosis model. A reduced clot size was observed after retinoic acid administration (35% reduction at a dose of 1 mg/kg). We could not detect any effect on ex-vivo measured platelet aggregation, bleeding time, prothrombin time, thrombin time, partial thromboplastin time or plasma fibrinogen level, indicating that there were no effects on platelet aggregation or blood coagulation. We conclude that retinoic acid enhanced fibrinolytic activity in-vivo by selectively enhancing t-PA activity and that retinoic acid is a potential anti-thrombotic agent in-vivo.
Production of Cryoprecipitate of Intermediate Purity in a Closed System Thaw-Siphon Process
Authors: Mason Ernest C , Pepper Duncan S , Griffin Brenda
Published: July 2018

The thaw-siphon procedure for routine production of cryoprecipitate is described briefly, and also its extension to a reproducible procedure for production of cryoprecipitates of intermediate purity. For the latter, the average yield of factor VIII is 60% of that in the prefrozon plasma and approximately 30% is present in the supernatant plasma. The product contains 0.53 units of VIII:C per mg of total protein (of which about 70% is clottable). The mean value of the ratio VIII:C/VIII:RAG is about 0.7. The yield and purity of the product compare favourably with those reported for intermediate purity factor VIII concentrates produced by large-scale plasma fractionation laboratories. The procedure offers an alternative pathway to the production of factor VIII concentrate of intermediate purity and can be operated in any blood bank with a minimum of equipment.
Studies on the Specific Fibrinolytic Effect of Human Extrinsic (Tissue-Type) Plasminogen Activator in Human Blood and in Various Animal Species in Vitro
Authors: Korninger C , Collen D
Published: July 2018

Human extrinsic (tissue-type) plasminogen activator (EPA) was highly purified from the culture fluid of a human melanoma cell line, both as a one-chain or as a two-chain molecule. Its specific fibrinolytic effect on human whole blood clots or plasma clots with different degrees of fibrin crosslinking was evaluated in an in vitro system, composed of a 125I-fibrin labeled clot, hanging in circulating human plasma. After infusion of EPA (30 IU per ml over 3 hrs), non-crosslinked clots lysed more extensively (75-100 percent in 5 hrs) than totally-crosslinked clots (50-65 percent), and no difference was found between one-chain or two-chain EPA. The extent of lysis of totally-crosslinked human or animal plasma clots hanging in autologous plasma induced by EPA varied markedly from one species to the other. When 90 IU of EPA were infused over 3 hrs, crosslinked human plasma clots dissolved for over 95 percent within 5 hrs. Under comparable conditions, the degree of lysis was 80 percent in primate plasma (cynomolgus fascicularis), 60 percent in cat and rabbit plasma, 30 percent in dog plasma and only 10 percent in rat plasma. Systemic activation of the fibrinolytic system in the circulating plasmas was minor and dose-dependent in all species, but complete fibrinogen breakdown was not observed in any species following infusion of up to 90 IU EPA per ml plasma.

It is concluded that the human system is more susceptible to EPA induced fibrinolysis than the other animal systems which were investigated, and that even totally-crosslinked clots can be lysed after infusion of EPA.
Arachidonic Acid-Induced Chemiluminescence of Human Platelets: Contribution of the Prostaglandin and Lipoxygenase Pathways
Authors: Wörner P
Published: July 2018

Two signals of chemiluminescence are observed when platelets are exposed to arachidonic acid in the presence of luminol. Three groups of agents interfere with these luminescence responses. Inhibitors of cyclooxygenase, known to augment the turnover of arachidonic acid by lipoxygenase, inhibit the first and enhance the second signal of luminescence.

Sodium azide, diamide, NEM, and the endoperoxide analogues U 44069 and U 46619 interfere with the second luminescence signal but not with the first one nor with the generation of MDA. These agents may represent selective inhibitors of the lipoxygenase pathway.

Phenidone, nordihydroguaiaretic acid, quercetin, silybin, phenylthiazolyl-thiourea, and aminotriazole inhibit both luminescence signals promoted by arachidonic acid.

Measurement of luminescence may provide a tool to follow the time course of arachidonic-acid turnover by prostaglandin synthetase and lipoxygenase in whole cells.
The Effect of Cod Liver Oil and Corn Oil on Platelets and Vessel Wall in Man
Authors: Brox Jan H , Killie Jan-Eirik , Gunnes Sigurd , Nordøy Arne
Published: July 2018

Ten healthy male subjects on an ordinary diet were given daily dietary supplement of 25 ml cod liver oil (CLO) or corn oil (CO) for periods of 6 weeks in a crossover study. Significant changes were observed in the plasma total fatty acid composition. The main platelet phospholipids fractions were also significantly altered, particularly by CLO with an increase of the eicosapentaenoic acid (EPA): arachidonic acid (AA) ratio. Both supplements reduced collagen induced platelet aggregation and TXB2 production, with CLO as the most potent one. No spontaneous release of an antiaggregatory substance or 6-keto-PcF1α from vein tissues were found, and the total urinary excretion of prostaglandin metabolites (E and F series) remained unchanged.
Studies of Phospholipid Reagents Used in Coagulation II: Factors Influencing Their Sensitivity to Heparin
Authors: Barrowcliffe T W , Gray Elaine
Published: July 2018

This study demonstrates the many technical variables which exist in the use of APTT reagents to detect and measure heparin. With the same phospholipid reagent different activation regimes produced significant differences in heparin sensitivity. The concentration of phospholipid was also an important influence; decreasing concentration led to increasing sensitivity, and the highest sensitivity was given by omitting the phospholipid altogether. Other factors which influenced the sensitivity to heparin were buffering of the reagents and the presence of oxidation products in the phospholipid. The results emphasize the need for standardisation of at least some of these variables if the APTT is to be used to determine the therapeutic range of heparin.
Activated Factor IX Complex in Treatment of Surgical Cases of Hemophilia A with Inhibitors
Authors: Hanna Wahid T , Madigan Robert R , Miles Marian A , Lange Robert D
Published: July 2018

Three patients with severe hemophilia A with inhibitors to factor VIII were treated with activated factor IX complex. Bleeiling was controlled adequately during surgical procedures involving each of the three. Partial thromboplastin times showed a variable shortening and prothrombin times were significantly shortened to values less than normal. Hemostasis was substantiated by the use of epsilon aminocaproic acid. Neither anamnestic responses nor thrombotic complications were observed. A transient hypertension developed in two patients shortly after infusion with the activated factor IX complex.
Stability of Prostacyclin in Human Plasma and Whole Blood: Studies on the Protective Effect of Albumin
Authors: Orchard M A , Robinson C
Published: July 2018

The biological half-life of prostacyclin in Krebs solution, human cell-free plasma or whole blood was measured by bracket assay on ADP-induced platelet aggregation. At 37°C, pH 7.4, plasma and blood reduced the rate of loss of antiaggregatory activity compared with Krebs solution. The protective effect of plasma was greater than that of whole blood. This effect could be partially mimicked by the addition of human or bovine serum albumin to the Krebs solution. The stabilisation afforded by human serum albumin was dependent on the fatty acid content of the albumin, although this was less important for bovine serum albumin.
Turnover of Human Extrinsic (Tissue-Type) Plasminogen Activator in Rabbits
Authors: Korninger C , Stassen J M , Collen D
Published: July 2018

The turnover of highly purified human extrinsic plasminogen activator (EPA) (one- and two-chain form) was studied in rabbits. Following intravenous injection, EPA-activity declined rapidly. The disappearance rate of EPA from the plasma could adequately be described by a single exponential term with a t ½ of approximately 2 min for both the one-chain and two-chain forms of EPA.

The clearance and organ distribution of EPA was studied by using 125I-labeled preparations. Following intravenous injection of 125I-1abeled EPA the radioactivity disappeared rapidly from the plasma also with a t ½ of approximately 2 min down to a level of 15 to 20 percent, followed by a small rise of blood radioactivity. Gel filtration of serial samples revealed that the secondary increase of the radioactivity was due to the reappearance of radioactive breakdown products in the blood. Measurement of the organ distribution of 125I at different time intervals revealed that EPA was rapidly accumulated in the liver, followed by a release of degradation products in the blood.

Experimental hepatectomy markedly prolonged the half-life of EPA in the blood. Blocking the active site histidine of EPA had no effect on the half-life of EPA in blood nor on the gel filtration patterns of 125I in serial plasma samples.

It is concluded that human EPA is rapidly removed from the blood of rabbits by clearance and degradation in the liver. Recognition by the liver does not require a functional active site in the enzyme. Neutralization in plasma by protease inhibitors does not represent a significant pathway of EPA inactivation in vivo.
Factor IX Alloantibodies Shorten the Bovine Thromboplastin Coagulation Time of Normal Human Plasma
Authors: Ørstavik Karen Helene
Published: July 2018

We have previously demonstrated that neutralization of factor IX in normal plasma by heterologous antisera shortens the one stage prothrombin time determined with bovine thromboplastin. In this study, a similar effect of homologous antibodies was demonstrated. Addition of plasma from two patients with hemophilia B- and an acquired inhibitor to factor IX gave a shortening of the prothrombin time of plasma from normal persons, compared to the prothrombin time determined after addition of control plasma from a patient with hemophilia B- and no inhibitor. Addition of inhibitor plasma had a similar effect on the prothrombin time of plasma from four patients with hemophilia B+ and one patient with hemophilia Br, but had no effect on the prothrombin time of plasma from ten patients with hemophilia B-. Complexes between factor IX and the human inhibitor could be demonstrated both before and after the coagulation with bovine thromboplastin. These complexes were demonstrated as a factor IX antigen with a reduced electrophoretic mobility in crossed immunoelectrophoresis against a rabbit antiserum to factor IX. The results demonstrate that normal factor IX loses the ability to act as an inhibitor in the coagulation with bovine thromboplastin after having formed a soluble complex with a homologous antibody, although the factor IX molecules still have antigenic determinants which are free to react with the rabbit antibodies.
Studies of a Fibrinolytic Enzyme from the Larvae of Lonomia achelous (Cramer) Using Chromogenic Peptide Substrates
Authors: Arocha-Piñango C L , Pepper D S
Published: July 2018

A fibrinolytic agent purified from the haemolymph, hair secretion and whole body extract of Lonomia achelous (Cramer)cleaves various chromogenic peptide substrates. The best substrate were found to be pyro-Glu-Gly-Arg-pNA (S-2444) followed by D-Pro-Phe-Arg-pNA (S-2302) and Bz-Ile-Glu-(or) Gly-Arg-pNA (S-2222) designed for urokinase, plasma kallikrein and factor Xa, respectively. Using substrate S-2251 we also found a plasminogen activator.
Is More Heparin Necessary for Low-Dose Heparin Prophylaxis in Uremic Patients?
Authors: Andrassy K , Salzmann W , Saggau W , Storch H , Ritz E
Published: July 2018

Heparin dose requirements for s. c. heparin prophylaxis were investigated in control individuals and in uremic patients. Heparin levels (neutralisation of factor Xa activity, neutralisation of Xa amidolytic activity; PTT and thrombin time) at timed intervals after single and repetitive s. c. doses of 5,000 or 7,500 IU were measured in 11 uremic patients and 9 individuals with normal renal function. At a dose of 2 × 5,000 IU/d heparin s. c. no difference between controls and uremic individuals was found. In contrast, in uremic patients, peak concentrations and area under the curve (AUC) were significantly lower and plasma half life shorter after 3 × 5,000 IU heparin s. c.

After repeated administration of heparin, heparin concentrations (24hrs) had fallen to nil in uremic patients whereas in controls measurable activity was still demonstrable. After i.v. bolus injection of heparin, peak concentrations were identical in controls and in uremic patients, but elimination half life was prolonged in uremic patients. It is therefore suggested that lower plasma heparin concentration after heparin s. c. is the result of diminished net absorption from the subcutaneous depot

It is concluded that in order to achieve a given plasma activity, higher s. c. doses of heparin must be administered to uremic patients than to non-uremic individuals. But further studies are required to demonstrate safety and efficacy of heparin prophylaxis in uremic individuals.
Comparison of Thrombelastography with Common Coagulation Tests
Authors: Zuckerman L , Cohen E , Vagher J P , Woodward E , Caprini J A
Published: July 2018

Thrombelastography, although proven as a useful research tool has not been evaluated for its clinical utility against common coagulation laboratory tests. In this study we compare the thrombelastographic measurements with six common tests (the hematocrit, platelet count, fibrinogen, prothrombin time, activated thromboplastin time and fibrin split products). For such comparisons, two samples of subjects were selected, 141 normal volunteers and 121 patients with cancer. The data was subjected to various statistical techniques such as correlation, ANOVA, canonical and discriminant analysis to measure the extent of the correlations between the two sets of variables and their relative strength to detect blood clotting abnormalities. The results indicate that, although there is a strong relationship between the thrombelastographic variables and these common laboratory tests, the thrombelastographic variables contain additional information on the hemostatic process.
Landmark Trials in Cardiology in 2017—Celebrating 40 Years of Angioplasty
Authors: Vishwakarma Pravesh , Sethi Rishi , Pradhan Akshyaya
Published: July 2018

Cardiovascular (CV) diseases continue to be the leading cause of morbidity and mortality worldwide. Significant progress has been made in the management of coronary artery disease (CAD) and acute coronary syndrome (ACS) over the past 3 decades. The year 2017 marks 40th anniversary of the first coronary angioplasty performed by Andreas Gruentzig in the year 1977. Evidence-based medicine and research has been the key driving force of these positive outcomes. The year 2017 witnessed presentation of several landmark studies at major meetings and many of them getting published in literature simultaneously. These trials evaluated wide range of issues from novel percutaneous coronary intervention (PCI) strategies to newer drugs to innovative devices in management of CAD. We selectively discuss a few major landmark studies that have the potential to alter our daily practice in 2018.
Surgical Decision Making in Preduodenal Portal Vein: Report of Two Cases in Neonates
Authors: Rusu Simona , Zaghal Ahmad , Choudhry Muhammad
Published: July 2018

Preduodenal portal vein (PDPV) is a rare anomaly that can cause duodenal obstruction. PDPV is associated with other congenital anomalies, mainly cardiac and gastrointestinal. Treatment usually consists of bypassing the obstruction by duodenoduodenostomy. We report two cases of PDPV in association with atrial isomerism and malrotation with different surgical management.
Patients' Perceptions of Atrial Fibrillation, Stroke Risk, and Oral Anticoagulation Treatment: An International Survey
Authors: Lane Deirdre , Meyerhoff Juliane , Rohner Ute , Lip Gregory
Published: July 2018

Background Global differences exist in the management of atrial fibrillation (AF), and cultural differences may influence patients' expectations and perceptions of healthcare. This survey investigated whether country-specific differences in patients' perceptions of AF and oral anticoagulation (OAC) exist and if recent stroke influences these perceptions.

Methods Cross-sectional survey of 937 adults with nonvalvular AF receiving OAC for stroke prevention was conducted across United States, Canada, Germany, France, and Japan. Thirty-minute online interviews conducted between April and November 2015 included AF patients with recent stroke, and newly diagnosed AF and established AF, both without recent stroke.

Results U.S. patients and those with recent stroke perceived AF as more serious (54.0 and 55.2%, respectively) and were more concerned about stroke (50.0 and 68.0%, respectively). Japanese patients were more likely to perceive AF as not serious (41.0%), but 50.4% were frequently concerned about stroke. Patients in the United States, Canada, and Germany and those without recent stroke preferred to be involved in OAC treatment decisions (either shared decision making or patient's choice), while French and Japanese patients and those with recent stroke preferred their doctor to choose. For all country groups, stroke prevention was the most important factor when choosing OAC.

Conclusion In this international cohort of AF patients, country-specific differences exist in patients' perceptions of AF, concerns about stroke, and preference for involvement in OAC treatment decisions; recent experience of stroke significantly influenced patients' values and preferences regarding AF and treatment. Stroke prevention was rated as the most important factor when choosing OAC treatment.
Quantum stereomagnetometry with a dual-core photonic-crystal fiber
Authors: Blakley S. M. , Fedotov I. V. , Becker J. , Zheltikov A. M.
Published: July 2018

A monolithic dual-core photonic crystal fiber (PCF) probe employing an integrated nitrogen-vacancy diamond microcrystal and microwave transmission line is shown to enable highly sensitive dual-channel vectorial magnetic field measurements by means of optical detection of magnetic resonances with both fiber cores. Reliable detection of microscale spatial magnetic-field variations on the order of 10 μT is demonstrated with a PCF probe possessing a core-to-core separation of 6 μm. Such a fiber probe is shown to provide a powerful tool for three-dimensional vectorial mapping of weak magnetic fields emanating from spatially localized objects.
Surface-selective bactericidal effect of poled ferroelectric materials
Authors: Kumar Sandeep , Vaish Rahul , Powar Satvasheel
Published: July 2018

The present study deals with the antibacterial performance of poled ferroelectric materials. For this purpose, Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZTO) piezoelectric ceramic has been synthesized and poled at different electric fields. The antibacterial performance of BCZTO poled and unpoled samples were examined. Approximately 88% of Escherichia coli degradation was recorded at the end of 1 h without any external intervention. Surface selective bacterial degradation was observed in poled materials. It was found that reactive oxygen species produced through electrocatalysis of water molecules play a crucial role in bacterial disinfection. The rate of bacterial degradation was further increased using ultrasonication with poled piezoelectric ceramics. Complete abolition of bacterial growth was achieved within 30 min of treatment with poled piezoelectric ceramic in an ultrasonicator. Results indicate that ferroelectric materials have substantial untapped potential in the field of antimicrobial methods.
Properties of the hard-sphere fluid at a planar wall using virial series and molecular-dynamics simulation
Authors: Paganini Iván E. , Davidchack Ruslan L. , Laird Brian B. , Urrutia Ignacio
Published: July 2018

We study the hard-sphere fluid in contact with a planar hard wall. By combining the inhomogeneous virial series with simulation results, we achieve a new benchmark of accuracy for the calculation of surface thermodynamics properties such as surface adsorption Γ and the surface free energy (or surface tension), γ. We briefly introduce the problem of choosing a position for the dividing surface and avoid it by proposing the use of alternative functions to Γ and γ that are independent of the adopted frame of reference. Finally, we present analytic expressions for the dependence of system surface thermodynamic properties on packing fraction, ensuring the high accuracy of the parameterized functions for any frame of reference. The proposed parametric expressions for both, Γ and γ, fit the accurate simulation results within the statistical error.
DESIREE electrospray ion source test bench and setup for collision induced dissociation experiments
Authors: de Ruette N. , Wolf M. , Giacomozzi L. , Alexander J. D. , Gatchell M. , Stockett M. H. , Haag N. , Zettergren H. , Schmidt H. T. , Cederquist H.
Published: July 2018

In this paper, we give a detailed description of an electrospray ion source test bench and a single-pass setup for ion fragmentation studies at the Double ElectroStatic Ion Ring ExpEriment infrastructure at Stockholm University. This arrangement allows for collision-induced dissociation experiments at the center-of-mass energies between 10 eV and 1 keV. Charged fragments are analyzed with respect to their kinetic energies (masses) by means of an electrostatic energy analyzer with a wide angular acceptance and adjustable energy resolution.
Tailoring the failure morphology of 2D bicrystalline graphene oxide
Authors: Verma Akarsh , Parashar Avinash , Packirisamy M.
Published: July 2018

The aim of this article is to study the effect of oxide functionalisation on the failure morphology of bicrystalline graphene. Molecular dynamics based simulations in conjunction with reactive force field were performed to study the mechanical properties as well as failure morphology of different configurations of bicrystalline graphene oxide. Separate simulations were performed with hydroxyl and epoxide functionalisation, and later on the same simulations were extended to study the graphene oxide as a whole. The authors have predicted that epoxide functionalisation helps in transforming the catastrophic brittle behaviour into ductile. Failure morphologies depict that epoxide groups tend to boost the ductility through altering the fracture path and not affecting the grain boundaries either. Also, the epoxide to ether transformations were found to be the decisive mechanism behind the plastic response shown by epoxide groups. Simulations help in concluding a ductile failure for bicrystalline graphene in conjunction with oxidation of selective atoms in the nanosheet, which further opens new avenues for the application of these graphene sheets in nanodevices and nanocomposites.
Probabilistic characterization of the Widom delta in supercritical region
Authors: Yoon Tae Jun , Ha Min Young , Lee Won Bo , Lee Youn-Woo
Published: July 2018

We present a probabilistic classification algorithm to understand the structural transition of supercritical Lennard-Jones (LJ) fluid. The classification algorithm is designed based on the exploratory data analysis on the nearest Voronoi neighbors of subcritical vapor and liquid. The algorithm is tested and applied to LJ type fluids modeled with the truncated and shifted potential and the Weeks-Chandler-Andersen potential. The algorithm makes it available to locate the Widom delta, which encloses the supercritical gas-liquid boundary and the percolation transition loci in a geometrical manner, and to conjecture the role of attractive interactions on the structural transition of supercritical fluids. Thus, the designed algorithm offers an efficient and comprehensible method to understand the phase behavior of a supercritical mesophase.
An approach to the measurement of the nonlinear refractive index of very short lengths of optical fibers
Authors: Rivera–Pérez E. , Carrascosa A. , Díez A. , Alcusa-Sáez E. P. , Andrés M. V.
Published: July 2018

A method for the measurement of the nonlinear-refractive index coefficient in single-mode optical fibers is presented. It takes advantage of the high sensitivity of the acousto-optic interaction effect in optical fibers to the fiber properties. Direct measurement of the nonlinear-refractive index change resulting from cross-phase modulation between a probe and a pump signal is obtained from the fiber's acousto-optic interaction performance. It is a non-interferometric method in which a very short length of fiber (<0.25 m) is required.
Non-local stresses in highly non-uniformly flowing suspensions: The shear-curvature viscosity
Authors: Jin H. , Kang K. , Ahn K. H. , Briels W. J. , Dhont J. K. G.
Published: July 2018

For highly non-uniformly flowing fluids, there are contributions to the stress related to spatial variations of the shear rate, which are commonly referred to as non-local stresses. The standard expression for the shear stress, which states that the shear stress is proportional to the shear rate, is based on a formal expansion of the stress tensor with respect to spatial gradients in the flow velocity up to leading order. Such a leading order expansion is not able to describe fluids with very rapid spatial variations of the shear rate, like in micro-fluidics devices and in shear-banding suspensions. Spatial derivatives of the shear rate then significantly contribute to the stress. Such non-local stresses have so far been introduced on a phenomenological level. In particular, a formal gradient expansion of the stress tensor beyond the above mentioned leading order contribution leads to a phenomenological formulation of non-local stresses in terms of the so-called “shear-curvature viscosity”. We derive an expression for the shear-curvature viscosity for dilute suspensions of spherical colloids and propose an effective-medium approach to extend this result to concentrated suspensions. The validity of the effective-medium prediction is confirmed by Brownian dynamics simulations on highly non-uniformly flowing fluids.
Magnetoresistance of epitaxial and polycrystalline Fe3O4 films near Verwey transition
Authors: Liu Xiang , Mi Wenbo , Zhang Qiang , Zhang Xixiang
Published: July 2018

We report investigations of magnetoresistance (MR) in epitaxial and polycrystalline Fe3O4 films. MR in epitaxial Fe3O4 films exhibits a local maximum at TV and a large value of −20% at 60 K. Based on a 1D half infinite spin chain model, the fitting parameter, which depends on the volume fraction of electronic scattering boundaries, sharply increases below TV with the decreased temperature. We suppose that the twin boundaries formed below TV facilitate the increase in MR and can act as antiphase boundaries (APBs) where the magnetic moments across twin boundaries are coupled antiferromagnetically. Similar MR behavior in Fe3O4(100) and (111) epitaxial films manifests the independence of MR on the spatial distribution of APBs. The outline of normalized MR in the epitaxial films shows a distinct temperature dependence. The temperature dependence may result from the different electronic transport mechanisms in Fe3O4 films. In a polycrystalline Fe3O4 film, MR comes from the disordered distribution of magnetic moments at grain boundaries. The effects of APBs, twin boundaries, and grain boundaries on MR are discussed in detail.
Whispering gallery mode lasing in lead halide perovskite crystals grown in microcapillary
Authors: Kurahashi Naho , Nguyen Van-Cao , Sasaki Fumio , Yanagi Hisao
Published: July 2018

Microcapillaries enable us to simply prepare crystalline perovskites in a microcavity. A precursor solution of methyl ammonium lead bromide (CH3NH3PbBr3) is injected by capillary action into quartz microcapillaries with an inner diameter (ϕ) of 2–40 μm. After drying at 70 °C in the atmosphere, cylindrical crystals are precipitated to fill up the inner cavity of the microcapillary. Under optical pumping, whispering gallery mode lasing depending on ϕ is observed. With reducing ϕ, the mode number and the lasing threshold fluence are found to be decreased. This suggests that the stimulated emission can be enhanced by cavity quantum electrodynamics in CH3NH3PbBr3 crystals which are densely confined in the microcavity. Consequently, the microcapillary with ϕ = 2 μm realizes single-mode lasing at a threshold fluence of 4.7 μJ/cm2.
Effect of Cu2O hole transport layer and improved minority carrier life time on the efficiency enhancement of Cu2NiSnS4 based experimental solar cell
Authors: Khattak Yousaf Hameed , Baig Faisal , Ullah Shafi , Marí Bernabé , Beg Saira , Khan Khurram
Published: July 2018

C u 2 NiSn S 4 is a non-toxic earth abundant material and a promising quaternary semiconductor compound. Due to its optimum direct band gap, it has been considered as a suitable absorber material for photovoltaic cells. It is a conspicuous and suitable class of material for the fabrication of low cost and high efficiency thin film devices. This paper presents numerical modeling for the efficiency enhancement of Cu2NiSnS4 based experimental photovoltaic cells. In this work, the experimental cell results were reproduced in the SCAPS software. These simulated results are validated and compared with the experimental reference cell. Cu2O as the hole transport layer is also proposed for further efficiency enhancement of the photovoltaic cell. After optimization of cell parameters, the power conversion efficiency of an optimized device is increased up to 4.60%. By applying the hole transport layer and analyzing the minority carrier life time, the conversion efficiency increases up to 10.35%. This work presents a novel concept in numerical modeling by analyzing the experimental solar cell, which will categorically offer new directions for the fabrication of high efficiency photovoltaic devices.
Decay characterization of solutions to generalized Hall-MHD system in R3
Authors: Zhao Xiaopeng , Zhu Mingxuan
Published: July 2018

By using the Fourier splitting method and the properties of decay character r*, we establish the time decay rate in the L2-norm for the weak solutions and the higher-order derivative of solutions for the generalized Hall-magnetohydrodynamic equations in R3. In particular, when (u0,b0)∈Hs(R3)⋂L1(R3) has decay character r*(u0) = r*(b0) = 0 and α = β = 1, then we recover the previous results of Chae and Schonbek [J. Differ. Equations 255, 3971–3982 (2013)].
A molecular journey in conservation genetics
Authors: Byrne Margaret
Published: July 2018

Genetics, and more recently genomics, has become an integral part of conservation science. From the early days of DNA fingerprinting through development of hybridisation based and polymerase chain reaction based markers, to applications of genomics, genetics has provided many insights to improve management of plants, animals and their ecosystems. I share my journey of discovery in genetics and genomics, and their application in conservation of plants through understanding evolutionary history, population genetics of rare and threatened species, molecular taxonomy, fragmentation and the role of pollen dispersal, restoration in a risk management context, and adaptation to climate change.
Immune nutrition and exercise: Narrative review and practical recommendations
Authors: Williams Neil C. , Killer Sophie C. , Svendsen Ida Siobhan , Jones Arwel Wyn
Published: July 2018

Evidence suggests that periods of heavy intense training can result in impaired immune cell function, and whether this leaves elite athletes at greater risk of infections and upper respiratory symptoms (URS) is still debated. There is some evidence that episodes of URS do cluster around important periods of competition and intense periods of training. Since reducing URS, primarily from an infectious origin, may have implications for performance, a large amount of research has focused on nutritional strategies to improve immune function at rest and in response to exercise. Although there is some convincing evidence that meeting requirements of high intakes in carbohydrate and protein and avoiding deficiencies in nutrients such as vitamin D and antioxidants is integral for optimal immune health, well‐powered randomised controlled trials reporting improvements in URS beyond such intakes are lacking. Consequently, there is a need to first understand whether the nutritional practices adopted by elite athletes increases their risk of URS. Second, promising evidence in support of efficacy and mechanisms of immune‐enhancing nutritional supplements (probiotics, bovine colostrum) on URS needs to be followed up with more randomised controlled trials in elite athletes with sufficient participant numbers and rigorous procedures with clinically relevant outcome measures of immunity.
Physiological comparison of intensity‐controlled, isocaloric intermittent and continuous exercise†
Authors: Combes Adrien , Dekerle Jeanne , Bougault Valérie , Daussin Frédéric N.
Published: July 2018

VO2 fluctuations are argued to be an important mechanism underpinning chronic adaptations following interval training. We compared the effect of exercise modality, continuous vs. intermittent realized at a same intensity, on electrical muscular activity, muscular oxygenation and on whole body oxygen uptake. Twelve participants (24 ± 5 years; VO2peak: 43 ± 6 mL· min−1·kg−1) performed (i) an incremental test to exhaustion to determine peak work rate (WRpeak); two randomized isocaloric exercises at 70%WRpeak; (ii) 1 bout of 30 min; (iii) 30 bouts of 1 min work intercepted with 1 min passive recovery. For electromyography, only the CON exercise showed change for the vastus lateralis root‐mean‐square (+6.4 ± 5.1%, P < .01, 95%CI 3.2, 8.3) and mean power frequency (−5.2 ± 4.8, P < .01, 95%CI −8.2, −3.5). Metabolic fluctuations (i.e. Oxygen Fluctuation Index and HHb Fluctuation Index) were higher in the intermittent modality, while post‐exercise blood lactate concentrations (4.80 ± 1.50 vs. 2.32 ± 1.21 mM, respectively, for the CON and INT, P < .01, 95%CI 1.72, 3.12) and the time spent over 90% of VO2 target (1644 ± 152 vs. 356 ± 301 sec, respectively, for the CON and INT, P < .01, 95%CI 1130, 1446) were higher in the continuous modality. In conclusion, despite a similar energy expenditure and intensity, intermittent and continuous exercises showed two very different physiological responses. The intermittent modality would lead to a larger recruitment of fast twitch fibres that are less mitochondria‐equipped and therefore may be more likely respondent to mitochondrial adaptations. In addition, this modality induces greater metabolic variations, a stimulus who could lead to mitochondrial development.
Koszul duality for Kac–Moody groups and characters of tilting modules
Authors: Achar Pramod , Makisumi Shotaro , Riche Simon , Williamson Geordie
Published: July 2018

We establish a character formula for indecomposable tilting modules for connected reductive groups in characteristicℓ\ellin terms ofℓ\ell-Kazhdan–Lusztig polynomials, forℓ>h\ell > hthe Coxeter number. Using results of Andersen, one may deduce a character formula for simple modules ifℓ≥2h−2\ell \ge 2h-2. Our results are a consequence of an extension to modular coefficients of a monoidal Koszul duality equivalence established by Bezrukavnikov and Yun.
Extracellular vesicles transfer nuclear Abl-dependent and radiation-induced miR-34c into unirradiated cells to cause bystander effects
Authors: Rastogi Shubhra , Hwang Amini , Chan Josolyn , Wang Jean Y. J.
Published: July 2018

Ionizing radiation (IR) not only activates DNA damage response (DDR) in irradiated cells but also induces bystander effects (BE) in cells not directly targeted by radiation. How DDR pathways activated in irradiated cells stimulate BE is not well understood. We show here that extracellular vesicles secreted by irradiated cells (EV-IR), but not those from unirradiated controls (EV-C), inhibit colony formation in unirradiated cells by inducing reactive oxygen species (ROS). We found that µEV-IR from Abl nuclear localization signal–mutated ( Abl-µNLS) cells could not induce ROS, but expression of wild-type Abl restored that activity. Because nuclear Abl stimulates miR-34c biogenesis, we measured miR-34c in EV and found that its levels correlated with the ROS-inducing activity of EV. We then showed that EV from miR-34c minigene–transfected, but unirradiated cells induced ROS; and transfection with miR-34c-mimic, without radiation or EV addition, also induced ROS. Furthermore, EV-IR from miR34-family triple-knockout cells could not induce ROS, whereas EV-IR from wild-type cells could cause miR-34c increase and ROS induction in the miR-34 triple-knockout cells. These results establish a novel role for extracellular vesicles in transferring nuclear Abl-dependent and radiation-induced miR-34c into unirradiated cells to cause bystander oxidative stress.
Relief of the Dma1-mediated checkpoint requires Dma1 autoubiquitination and dynamic localization
Authors: Jones Christine M. , Chen Jun-Song , Johnson Alyssa E. , Elmore Zachary C. , Cullati Sierra N. , Beckley Janel R. , Gould Kathleen L.
Published: July 2018

Chromosome segregation and cell division are coupled to prevent aneuploidy and cell death. In the fission yeast Schizosaccharomyces pombe, the septation initiation network (SIN) promotes cytokinesis, but upon mitotic checkpoint activation, the SIN is actively inhibited to prevent cytokinesis from occurring before chromosomes have safely segregated. SIN inhibition during the mitotic checkpoint is mediated by the E3 ubiquitin ligase Dma1. Dma1 binds to the CK1-phosphorylated SIN scaffold protein Sid4 at the spindle pole body (SPB), and ubiquitinates it. Sid4 ubiquitination antagonizes the SPB localization of the Pololike kinase Plo1, the major SIN activator, so that SIN signaling is delayed. How this checkpoint is silenced once spindle defects are resolved has not been clear. Here we establish that Dma1 transiently leaves SPBs during anaphase B due to extensive autoubiquitination. The SIN is required for Dma1 to return to SPBs later in anaphase. Blocking Dma1 removal from SPBs by permanently tethering it to Sid4 prevents SIN activation and cytokinesis. Therefore, controlling Dma1’s SPB dynamics in anaphase is an essential step in S. pombe cell division and the silencing of the Dma1-dependent mitotic checkpoint.
Delineating the origins, developmental programs and homeostatic functions of tissue-resident macrophages
Authors: Mass Elvira
Published: July 2018

A literature covering 150 years of research indicates that macrophages are a diverse family of professional phagocytes that continuously explore their environment, recognize and scavenge pathogens, unfit cells, cell debris as well as metabolites, and produce a large range of bioactive molecules and growth factors. A new paradigm suggests that most tissue-resident macrophages originate from fetal precursors that colonize developing organs and self-maintain independently of bone marrow-derived cells throughout life. The differentiation of these precursors is driven by a core macrophage transcriptional program and immediately followed by their specification through expression of tissue-specific transcriptional regulators early during embryogenesis. Despite our increasing understanding of ontogeny and genetic programs that shape differentiation processes and functions of macrophages, the precise developmental trajectories of tissue-resident macrophages remain undefined. Here, I review current models of fetal hematopoietic waves, possible routes of macrophage development and their roles during homeostasis. Further, transgenic mouse models are discussed providing a toolset to study the developmentally and functionally distinct arms of the phagocyte system in vivo.
A 2′-O-Methyltransferase Responsible for Transfer RNA Anticodon Modification Is Pivotal for Resistance toPseudomonas syringaeDC3000 inArabidopsis
Authors: Ramírez Vicente , González Beatriz , López Ana , Castelló Maria Jose , Gil Maria José , Zheng Bo , Chen Peng , Vera Pablo
Published: July 2018

Transfer RNA (tRNA) is the most highly modified class of RNA species in all living organisms. Recent discoveries have revealed unprecedented complexity in the tRNA chemical structures, modification patterns, regulation, and function, suggesting that each modified nucleoside in tRNA may have its own specific function. However, in plants, our knowledge of the role of individual tRNA modifications and how they are regulated is very limited. In a genetic screen designed to identify factors regulating disease resistance in Arabidopsis, we identified SUPPRESSOR OF CSB3 9 (SCS9). Our results reveal SCS9 encodes a tRNA methyltransferase that mediates the 2′-O-ribose methylation of selected tRNA species in the anticodon loop. These SCS9-mediated tRNA modifications enhance susceptibility during infection with the virulent bacterial pathogen Pseudomonas syringae DC3000. Lack of such tRNA modification, as observed in scs9 mutants, specifically dampens plant resistance against DC3000 without compromising the activation of the salicylic acid signaling pathway or the resistance to other biotrophic pathogens. Our results support a model that gives importance to the control of certain tRNA modifications for mounting an effective disease resistance in Arabidopsis toward DC3000 and, therefore, expands the repertoire of molecular components essential for an efficient disease resistance response.