bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Periodontal Biotype in a Young Chinese Population using Different Measurement Methods
Authors: Shao Yunmin , Yin Lanlan , Gu Jianyu , Wang Dongmiao , Lu Wei , Sun Ying
Published: July 2018

Periodontal biotype is used to describe the morphological characteristics of periodontal tissues and is closely related to periodontal health and prognosis of many dental treatments. This study was undertaken to explore the periodontal biotype distribution in a young Chinese population and to evaluate the accuracy of different methods for gingival thickness (GT) measurement. A total of 372 teeth from 31 periodontally healthy subjects were included. GT was measured simultaneously by probe transparency, transgingival probing and cone-beam computed tomography (CBCT). Some other anatomic parameters, including crown width/crown length ratio, attached gingival width, labial bone thickness and papilla volume were recorded for periodontal biotype classification. As found by probe transparency, the gingivae of 222 teeth (59.68%) were thick, while those of 150 teeth (40.32%) were thin. The mean GT of included subjects was 1.03 ± 0.31 mm as measured by transgingival probing and 1.03 ± 0.24 mm as measured by CBCT. Four groups were identified by cluster analysis. Thick-flap biotype, average-scalloped biotype, average-flap biotype and thin-scalloped biotype comprised 137 teeth (36.83%), 96 teeth (25.81%), 39 teeth (10.48%) and 100 teeth (26.88%), respectively. These results demonstrate that the most common periodontal biotype in this young Chinese population was the thick-flap type with low aesthetic risk.
Methodological bias associated with soluble protein recovery from soil
Authors: Greenfield Lucy M. , Hill Paul W. , Paterson Eric , Baggs Elizabeth M. , Jones Davey L.
Published: July 2018

Proteins play a crucial role in many soil processes, however, standardised methods to extract soluble protein from soil are lacking. The aim of this study was to compare the ability of different extractants to quantify the recovery of soluble proteins from three soil types (Cambisol, Ferralsol and Histosol) with contrasting clay and organic matter contents. Known amounts of plant-derived14C-labelled soluble proteins were incubated with soil and then extracted with solutions of contrasting pH, concentration and polarity. Protein recovery proved highly solvent and soil dependent (Histosol > Cambisol > Ferralsol) and no single extractant was capable of complete protein recovery. In comparison to deionised water (10–60% of the total protein recovered), maximal recovery was observed with NaOH (0.1 M; 61–80%) and Na-pyrophosphate (0.05 M, pH 7.0; 45–75% recovery). We conclude that the dependence of protein recovery on both extractant and soil type prevents direct comparison of studies using different recovery methods, particularly if no extraction controls are used. We present recommendations for a standard protein extraction protocol.
Spatially restricted subcellular Ca2+ signaling downstream of store-operated calcium entry encoded by a cortical tunneling mechanism
Authors: Courjaret Raphael , Dib Maya , Machaca Khaled
Published: July 2018

Agonist-dependent Ca2+ mobilization results in Ca2+ store depletion and Store-Operated Calcium Entry (SOCE), which is spatially restricted to microdomains defined by cortical ER – plasma membrane contact sites (MCS). However, some Ca2+-dependent effectors that localize away from SOCE microdomains, are activated downstream of SOCE by mechanisms that remain obscure. One mechanism proposed initially in acinar cells and termed Ca2+ tunneling, mediates the uptake of Ca2+ flowing through SOCE into the ER followed by release at distal sites through IP3 receptors. Here we show that Ca2+ tunneling encodes exquisite specificity downstream of SOCE signal by dissecting the sensitivity and dependence of multiple effectors in HeLa cells. While mitochondria readily perceive Ca2+ release when stores are full, SOCE shows little effect in raising mitochondrial Ca2+, and Ca2+-tunneling is completely inefficient. In contrast, gKCa displays a similar sensitivity to Ca2+ release and tunneling, while the activation of NFAT1 is selectively responsive to SOCE and not to Ca2+ release. These results show that in contrast to the previously described long-range Ca2+ tunneling, in non-specialized HeLa cells this mechanism mediates spatially restricted Ca2+ rise within the cortical region of the cell to activate a specific subset of effectors.
First-principles investigation of the micromechanical properties of fcc-hcp polymorphic high-entropy alloys
Authors: Li Xiaoqing , Irving Douglas L. , Vitos Levente
Published: July 2018

High-entropy alloys offer a promising alternative in several high-technology applications concerning functional, safety and health aspects. Many of these new alloys compete with traditional structural materials in terms of mechanical characteristics. Understanding and controlling their properties are of the outmost importance in order to find the best single- or multiphase solutions for specific uses. Here, we employ first-principles alloy theory to address the micro-mechanical properties of five polymorphic high-entropy alloys in their face-centered cubic (fcc) and hexagonal close-packed (hcp) phases. Using the calculated elastic parameters, we analyze the mechanical stability, elastic anisotropy, and reveal a strong correlation between the polycrystalline moduli and the average valence electron concentration. We investigate the ideal shear strength of two selected alloys under shear loading and show that the hcp phase possesses more than two times larger intrinsic strength than that of the fcc phase. The derived half-width of the dislocation core predicts a smaller Peierls barrier in the fcc phase confirming its increased ductility compared to the hcp one. The present theoretical findings explain a series of important observations made on dual-phase alloys and provide an atomic-level knowledge for an intelligent design of further high-entropy materials.
Trichlorfon and spinosad resistance survey and preliminary determination of the resistance mechanism in Pakistani field strains of Bactrocera dorsalis
Authors: Khan Hafiz Azhar Ali , Akram Waseem
Published: July 2018

The use of insecticides has been a primary tool to manage Bactrocera dorsalis in Pakistan; however, recent reports of field control failures necessitate mapping out the insecticide resistance problem. Therefore, eight field strains from Pakistan, were evaluated for their resistance against trichlorfon and spinosad. Compared with a reference strain, six field strains showed high levels of resistance to trichlorfon, while two field strains expressed intermediate resistance. In case of spinosad, five field strains fell in the susceptible range, whereas, the rest of the strains represented minor resistance. Correlation analysis between LD50 values of trichlorfon and spinosad of all the field strains revealed non-significant association, suggesting the possibility of lack of cross-resistance between both insecticides. Synergism bioassays implementing S,S,S-tributylphosphorotrithioate (DEF) and piperonyl butoxide (PBO) revealed that the LD50 values of trichlorfon in the presence of either DEF or PBO in seven field strains were significantly reduced. However, DEF and PBO had a non-significant effect on synergizing spinosad toxicity. The results revealed resistance to trichlorfon in field strains of B. dorsalis, which might be metabolic-based. Absence or minor resistance to spinosad and lack of cross-resistance to trichlorfon, suggest that spinosad could be a potential candidate for managing B. dorsalis.
Catalytic chemistry of glucose oxidase in cancer diagnosis and treatment
Authors: Fu Lian-Hua , Qi Chao , Lin Jing , Huang Peng
Published: July 2018

This tutorial review focuses on the state-of-the-art progress in GOx-based cancer diagnosis and treatment, including the general principles for the design and construction of GOx-based biosensors and cancer therapeutic approaches, and their biological applications in detail. Moreover, the current trends and key problems, as well as the challenges and future prospects of GOx-based catalytic systems in biomedicine are also discussed in the end.
Field-induced single-molecule magnet behavior in ideal trigonal antiprismatic cobalt(ii) complexes: precise geometrical control by a hydrogen-bonded rigid metalloligand
Authors: Mitsuhashi Ryoji , Pedersen Kasper S. , Ueda Takaaki , Suzuki Takayoshi , Bendix Jesper , Mikuriya Masahiro
Published: July 2018

A new cobalt(ii) field-induced single-molecule magnet with an ideal trigonal antiprismatic geometry was prepared taking advantage of structure-directing intermolecular hydrogen-bonds.
Solubility prediction from first principles: a density of states approach
Authors: Boothroyd Simon , Kerridge Andy , Broo Anders , Buttar David , Anwar Jamshed
Published: July 2018

Solubility is a fundamental property of widespread significance. Its accurate prediction remains a major challenge. We present a novel, efficient approach to solubility prediction for molecules over a range of conditions based on density of states.
Influence of interface inhomogeneity on the electrical transport mechanism of CdSe nanowire/Au Schottky junctions
Authors: Jin Weifeng , Mu Xiaojing , Zhang Kun , Shang Zhengguo , Dai Lun
Published: July 2018

Schottky barrier inhomogeneity and its influence on the electrical transport mechanism of single nanowire-based Schottky junctions have been investigated.
Fragmentation of a dioxolanyl radical via nonstatistical reaction dynamics: characterization of the vinyloxy radical by ns time-resolved laser flash photolysis
Authors: Bucher Götz , Lal Mukul , Rana Anup , Schmittel Michael
Published: July 2018

Photolysis of a dioxolanyl Barton ester results in formation of the vinyloxy radical, via nonstatistical reaction dynamics. The nonstatistical reaction involves ester cleavage, CO2 loss and fragmentation of the intermediate dioxolanyl radical.
The effect of the block ratio on the thermal conductivity of amorphous polyethylene–polypropylene (PE–PP) diblock copolymers
Authors: Wei Xingfei , Luo Tengfei
Published: July 2018

Block copolymers have a wide range of applications, such as battery electrolytes and nanoscale pattern generation.
Calix[4]pyrroles as macrocyclic organocatalysts for the synthesis of cyclic carbonates from epoxides and carbon dioxide
Authors: Maeda Chihiro , Sasaki Sota , Takaishi Kazuto , Ema Tadashi
Published: July 2018

meso-Octamethylcalix[4]pyrrole worked as an organocatalyst for the conversion of epoxides and CO2 into cyclic carbonates under solvent-free conditions.
Preparation and reactivity of rhodium and iridium complexes containing a methylborohydride based unit supported by two 7-azaindolyl heterocycles
Authors: Da Costa Rosenildo Correa , Rawe Benjamin W. , Tsoureas Nikolaos , Haddow Mairi F. , Sparkes Hazel A. , Tizzard Graham J. , Coles Simon J. , Owen Gareth R.
Published: July 2018

A new methyl substituted scorpionate ligand has been coordinated to group nine complexes. The reactivity of the complexes was explored.
Rice-shaped porous ZnMn2O4 microparticles as advanced anode materials for lithium-ion batteries
Authors: Chen Sheng , Feng Xuejiao , Yao Mengya , Wang Yanming , Wang Fei , Zhang Yongxing
Published: July 2018

Novel rice-shaped porous ZnMn2O4 microparticles made of nanoparticles were prepared by the calcination of Zn0.33Mn0.67CO3 precursors synthesized using a facile triethanolamine-assisted solvothermal method.
Sulforaphane ameliorates glucose intolerance in obese mice via the upregulation of the insulin signaling pathway
Authors: Xu Yan , Fu Jian-Fei , Chen Jia-Hui , Zhang Zhuang-Wei , Zou Zu-Quan , Han Li-Yuan , Hua Qi-Hang , Zhao Jin-Shun , Zhang Xiao-Hong , Shan Yu-Juan
Published: July 2018

Sulforaphane (SFN) is a dietary component with multiple bioactivities; however, its role in obesity-related metabolic derangement remains unclear.
Gas sensing properties of 3D mesoporous nanostructured ZnO thin films
Authors: Patil V. L. , Kumbhar S. S. , Vanalakar S. A. , Tarwal N. L. , Mali S. S. , Kim J. H. , Patil P. S.
Published: July 2018

We successfully deposited a three dimensional (3D) mesoporous ZnO nanostructure on a glass substrate by using a hydrothermal method, and tested the material for its gas sensing performance.
One-pot microwave-assisted synthesis of organotin Schiff bases: an optical and electrochemical study towards their effects in organic solar cells
Authors: Cantón-Díaz Arelly M. , Muñoz-Flores Blanca M. , Moggio Ivana , Arias Eduardo , De León Arxel , García-López María C. , Santillán Rosa , Ochoa María E. , Jiménez-Pérez Víctor M.
Published: July 2018

One-pot microwave synthesized organotin compound has been employed as good electro-acceptor (EA) and cheap for organic photovoltaic (OPV) solar cells.
Dislocation driven spiral and non-spiral growth in layered chalcogenides
Authors: Nie Yifan , Barton Adam T. , Addou Rafik , Zheng Yongping , Walsh Lee A. , Eichfeld Sarah M. , Yue Ruoyu , Cormier Christopher R. , Zhang Chenxi , Wang Qingxiao , Liang Chaoping , Robinson Joshua A. , Kim Moon , Vandenberghe William , Colombo Luigi , Cha Pil-Ryung , Wallace Robert M. , Hinkle Christopher L. , Cho Kyeongjae
Published: July 2018

Evidence from simulations and experiments reveals the mechanistic similarities between concentric growth and spiral growth.
A CuO-functionalized NMOF probe with a tunable excitation wavelength for selective detection and imaging of H2S in living cells
Authors: Ma Yu , Zhang Caiyun , Yang Peng , Li Xiangyuan , Tong Lili , Huang Fang , Yue Jieyu , Tang Bo
Published: July 2018

A CuO-functionalized NMOF probe with a tunable excitation wavelength is presented for selective detection and imaging of H2S in living cells.
A bioinspired structured graphene surface with tunable wetting and high wearable properties for efficient fog collection
Authors: Song Yun-yun , Liu Yan , Jiang Hao-bo , Li Shu-yi , Kaya Cigdem , Stegmaier Thomas , Han Zhi-wu , Ren Lu-quan
Published: July 2018

We have successfully designed a special bioinspired hybrid wetting surface on a copper mesh with tunable wetting for fog collection.
Ti2C3Tx nanosheets as photothermal agents for near-infrared responsive hydrogels
Authors: Yang Changyu , Xu Danyun , Peng WenChao , Li Yang , Zhang Guoliang , Zhang Fengbao , Fan Xiaobin
Published: July 2018

A facile method to incorporate exfoliated Ti2C3Tx nanosheets in the PNIPAM network is reported. The obtained MXene/PNIPAM composite hydrogel shows excellent photothermal properties, expanding the pure thermal-responsive property of the PNIPAM hydrogel.
Heteroaryl-linked norbornadiene dimers with redshifted absorptions
Authors: Mansø Mads , Tebikachew Behabitu Ergette , Moth-Poulsen Kasper , Nielsen Mogens Brøndsted
Published: July 2018

The longest-wavelength absorption maximum of norbornadiene dimers with potential for molecular solar thermal systems can be finely tuned by varying the electronic nature of a heteroaryl spacer.
Enhanced removal of hexavalent chromium from aqueous media using a highly stable and magnetically separable rosin-biochar-coated TiO2@C nanocomposite
Authors: Yousaf Balal , Liu Guijian , Abbas Qumber , Wang Ruwei , Ullah Habib , Mian Md Manik , Amina Amina , Rashid Audil
Published: July 2018

A biochar-coated RBC-TiO2@C nanocomposite was synthesized using a wet chemical coating followed by a one-step heating route (pyrolysis) for the efficient removal of Cr(vi).
Size-controllable synthesis of NiCoSe2 microspheres as a counter electrode for dye-sensitized solar cells
Authors: Chen Xiaobo , Ding Jingguo , Li Yan , Wu Yinxia , Zhuang Guoce , Zhang Cuicui , Zhang Zhihai , Zhu Chengyun , Yang Peizhi
Published: July 2018

The PCE value of the NiCoSe2-150-based DSSC is 8.76%, which is higher than that of DSSCs based on Pt (8.22%).
Folate-targeted selenium nanoparticles deliver therapeutic siRNA to improve hepatocellular carcinoma therapy
Authors: Xia Yu , Zhao Mingqi , Chen Yi , Hua Liang , Xu Tiantian , Wang Changbing , Li Yinghua , Zhu Bing
Published: July 2018

We provide an effective strategy for the design of tumor-targeted nanodrugs against hepatocellular carcinoma by functionalising Se nanoparticles with polyethylenimine linked with folic acid and siRNA.
Effect of slight structural changes on the gelation properties of N-phenylstearamide supramolecular gels
Authors: Meyer Alexandre R. , Bender Caroline R. , dos Santos Daniel M. , Ziembowicz Francieli I. , Frizzo Clarissa P. , Villetti Marcos A. , Reichert José M. , Zanatta Nilo , Bonacorso Helio G. , Martins Marcos A. P.
Published: July 2018

The effect of slight structural changes on several supramolecular gel properties were evaluated by the test tube method, UV-Vis, 1H NMR, rheology and DSC experiments.
CBMNet: the ‘Crossing Biological Membranes’ network in industrial biotechnology and bioenergy
Authors: Vanderhoven Jen , Green Jeffrey , Thomas Gavin H.
Published: July 2018

The ∼1300 academic and industry members of the BBSRC (Biotechnology and Biological Sciences Research Council) Network in Industrial Biotechnology and Bioenergy (NIBB) Crossing Biological Membranes Network (CBMNet) are motivated to explore how knowledge of the roles of biological membranes can be exploited to enhance the productivity of cell factories. Improving existing, and developing new, cell factories requires a deep understanding of the mechanisms by which substances are transported into, within, and out of the cells. Embedding consideration of membrane function into the design of cell factories is crucial for the future of almost all cell-based Industrial Biotechnology and Bioenergy (IBBE) applications. CBMNet provides a forum for: knowledge exchange between academics and companies; developing new interactions in the context of responsible innovation; forming, and then supporting, new multi-disciplinary teams to develop innovative membrane-based solutions to overcome IBBE bottlenecks; and funding consortia to carry out feasibility studies with the target of generating competitive bids for further research funding. More broadly, CBMNet is working with other NIBB to raise the profile of IBBE among policymakers and develop a national strategy for IBBE in the U.K.
Sex-dependent expression of brain medullary MAP and PI3 kinases in adult sheep with antenatal betamethasone exposure
Authors: Hendricks Alexa S. , Shaltout Hossam A. , Westwood Brain M. , Chappell Mark C. , Diz Debra I.
Published: July 2018

Antenatal betamethasone (BM) therapy for women in jeopardy of premature delivery accelerates the lung development in preterm infants and reduces infant mortality rates, but may induce early programming events with chronic cardiovascular consequences. In a sheep model of fetal programming, in utero BM-exposed (BMX) offspring as adults exhibit elevated mean arterial pressure (MAP), decreased baroreflex sensitivity (BRS) for the control of heart rate and insulin resistance accompanied by dysregulation of the brain renin–angiotensin (Ang) system (RAS). However, the status of signaling mechanisms in the brain dorsomedial medulla (DMM) of the BMX sheep that comprise both the mitogen activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) cellular pathways is unknown. Given the importance of these signaling pathways in the actions of Ang peptides as well as baroreflex function and autonomic integration, we applied both a kinase signaling array and associated individual immunoblots of the dorsomedial brain medulla from adult female and male sheep with antenatal BMX. MAPK and PI3K pathways were altered significantly in the BMX sheep in a sex-dependent manner. A protein array for kinases (PathScan® Intracellular Signaling Array Kit, Cell Signaling) and subsequent verification by immunoblot revealed that within the DMM, female BMX sheep exhibit lower expression of proteins in the PI3K pathway, while male BMX sheep show greater expression of p-MAPK pathway proteins extracellular signal regulated kinase (ERK) 1/2. We conclude that maladaptive changes in these two kinase pathways in the DMM may contribute to the chronic dysregulation of blood pressure in this model of fetal programming.
Testing general relativity with geodetic VLBI
Authors: Titov O. , Girdiuk A. , Lambert S. B. , Lovell J. , McCallum J. , Shabala S. , McCallum L. , Mayer D. , Schartner M. , de Witt A. , Shu F. , Melnikov A. , Ivanov D. , Mikhailov A. , Yi S. , Soja B. , Xia B. , Jiang T.
Published: July 2018

Context. We highlight the capabilities of geodetic VLBI technique to test general relativity in the classical astrometric style, i.e. measuring the deflection of light in the vicinity of the Sun.

Aims. In previous studies, the parameterγwas estimated by global analyses of thousands of geodetic VLBI sessions. Here we estimateγfrom a single session where the Sun has approached two strong reference radio sources, 0229+131 and 0235+164, at an elongation angle of 1–3°.

Methods. The AUA020 VLBI session of 1 May 2017 was designed to obtain more than 1000 group delays from the two radio sources. The solar corona effect was effectively calibrated with the dual-frequency observations even at small elongation.

Results. We obtainedγwith a greater precision (0.9 × 10−4) than has been obtained through global analyses of thousands of standard geodetic sessions over decades. Current results demonstrate that the modern VLBI technology is capable of establishing new limits on observational tests of general relativity.
Evaluating the effects of source conditions on coded-aperture based X-ray phase contrast imaging
Authors: Zhang Cui , Pan Xiaodong , Shang Hongjie , Ding Jingjie , Li Gongping
Published: July 2018

Coded-aperture based imaging is a non-interferometric X-ray phase contrast imaging technique, which is based on the edge illumination principle. It enhances the image contrast and relaxes the requirements on experimental conditions, such as source sizes and detectors. Quantitative phase and absorption information can be retrieved by two opposite acquisitions. However, the retrieving accuracy and sensitivity depend on source conditions and experimental setups. In this paper, we present a new derivation for the laboratory-based retrieving method by using the slope at the center of the standard illumination curve. By analyzing the beam distribution on the detector with different source conditions, several corresponding extracting formulae are derived. Simulation results suggest that our extracting formulae can extract a relatively stable and accurate result of refraction angle with different X-ray sources. The sensitivity to refraction angle decreases with the increase of source size, its maximum value is determined by the sample aperture. Furtherly, sensitivity will be decreased when the detector aperture is small, because the edges of the beam are blocked by the detector mask. This work helps to choose the X-ray sources and to optimize the experimental setups, moreover, to improve the quantitative extracting accuracy of the refraction angle.
Comparison between slag refining processes for B removal with metallurgical grade silicon and Si–Sn alloy
Authors: Al-khazraji Rowaid , Li Yaqiong , Zhang Lifeng
Published: July 2018

Boron (B) removal by slag refining using CaO–SiO2–CaCl2 was investigated in metallurgical-grade silicon (MG-Si) and 75 wt% Si–Sn alloy. Experiments were conducted at 1500 °C for 15 min. The microstructure was characterized before and after refining. The effects of acid leaching, basicity, and slag/Si mass ratio on B removal were investigated. Experimental results showed that acid leaching had no effect on B removal from MG-Si but had a clear effect on the refined Si–Sn alloy after slag refining. The final B concentration was highly affected by the CaO/SiO2 mass ratio with minimum value, where the content of B was reduced from 18.36 ppmw to 5.5 ppmw at the CaO/SiO2 = 1.2 for MG-Si slag refining and from 18.36 ppmw to 3.7 ppmw at CaO/SiO2 = 1.5 for 75 wt% Si–Sn alloy. Increasing the slag mass ratio by 2:1 mass ratio also increased B removal efficiency by approximately 15–20% more than an increase by 1:1.
Aqueous Medium Preparation of Dialkyldiselenides
Authors: Manna Tapasi , Misra Anup
Published: July 2018

One-pot, two-step reaction conditions have been developed for the preparation of dialkyl diselenides by the treatment of alkyl halides with potassium selenocyanate followed by alkaline hydrolysis of the in situ generated alkyl selenocyanate in water. The reaction is reasonably fast and the yields of the products were very good. Several functional groups present in the substrates were unaffected under the reaction conditions.
Platelet Aggregation in Finnish Men and Its Relation to Fatty Acids in Platelets, Plasma and Adipose Tissue
Authors: Salo M K , Vartiainen E , Puska P , Nikkari T
Published: July 2018

Platelet aggregation and its relation to fatty acid composition of platelets, plasma and adipose tissue was determined in 196 randomly selected, free-living, 40-49-year-old men in two regions of Finland (east and southwest) with a nearly twofold difference in the IHD rate.

There were no significant east-southwest differences in platelet aggregation induced with ADP, thrombin or epinephrine. ADP-induced platelet secondary aggregation showed significant negative associations with all C20-C22 ω3-fatty acids in platelets (r = -0.26 - -0.40) and with the platelet 20: 5ω3/20: 4ω 6 and ω3/ ω6 ratios, but significant positive correlations with the contents of 18:2 in adipose tissue (r = 0.20) and plasma triglycerides (TG) (r = 0.29). Epinephrine-induced aggregation correlated negatively with 20: 5ω 3 in plasma cholesteryl esters (CE) (r = -0.23) and TG (r = -0.29), and positively with the total percentage of saturated fatty acids in platelets (r = 0.33), but had no significant correlations with any of the ω6-fatty acids. Thrombin-induced aggregation correlated negatively with the ω3/6ω ratio in adipose tissue (r = -0.25) and the 20: 3ω6/20: 4ω 6 ratio in plasma CE (r = -0.27) and free fatty acids (FFA) (r = -0.23), and positively with adipose tissue 18:2 (r = 0.23) and 20:4ω6 (r = 0.22) in plasma phospholipids (PL).

The percentages of prostanoid precursors in platelet lipids, i. e. 20: 3ω 6, 20: 4ω 6 and 20 :5ω 3, correlated best with the same fatty acids in plasma CE (r = 0.32 - 0.77) and PL (r = 0.28 - 0.74). Platelet 20: 5ω 3 had highly significant negative correlations with the percentage of 18:2 in adipose tissue and all plasma lipid fractions (r = -0.35 - -0.44).

These results suggest that, among a free-living population, relatively small changes in the fatty acid composition of plasma and platelets may be reflected in significant differences in platelet aggregation, and that an increase in linoleate-rich vegetable fat in the diet may not affect platelet function favourably unless it is accompanied by an adequate supply of ω3 fatty acids.
Heparin Response and Clearance in Acute and Chronic Liver Disease
Authors: Sette H , Hughes R D , Langley P G , Gimson A E S , Williams R
Published: July 2018

Patients with liver disease are at risk of bleeding due to abnormalities of the clotting system although they must be anticoagulated if they require haemodialysis or haemoperfusion. The anticoagulant of choice is heparin.

In this study we have investigated heparin kinetics in patients with fulminant hepatic failure (FHF) after a single intravenous dose of heparin (2,500 units) and found there was an increased clearance of heparin whether measured by its anti-Xa effect (t1/2 = 27.8 ± 2.9 min compared to t1/2 = 50.2 ± 2.7 min in normal controls p <0.001) or by the whole blood activated clotting time (t1/2 = 23.7 ± 2.2 min compared to t1/2 = 37.0 ± 2.0 min p <0.001). There was a decreased peak level of heparin measured by anti-Xa effect (peak level in FHF = 0.48 ± 0.05 u/ml and in controls = 0.69 ± 0.04 u/ml, p <0.02), but an increased sensitivity to heparin (sensitivity in FHF = 0.072 ± 0.011 sec/unit, in controls 0.033 ± 0.003 sec/unit, p <0.001). Patients with FHF had very low levels of antithrombin III (AT III), but there was no correlation between this and any parameters of heparin effect or clearance. In a group of patients with chronic liver disease heparin kinetics did not differ from controls despite low levels of AT III.

The changes in heparin kinetics in FHF are likely to be complex with the balance between the proteins that act as cofactors, (e.g. AT III) and the proteins that have heparin neutralising activity, controlling the response of added heparin.
Intrahepatic Kinetics of lndium-111-Labelled Platelets
Authors: Peters A M , Saverymuttu S H , Malik F , Ind P W , Lavender J P
Published: July 2018

The intrahepatic kinetics of 111indium-labelled platelets have been studied using dynamic gamma camera scintigraphy immediately following injection. Platelets labelled in saline with mIn-oxine or 111In-acetylacetonate underwent rapidly reversible hepatic sequestration, indicating that they were “activated”. Platelets labelled in plasma with 111In-tropolonate, however, did not display this phenomenon. On the assumption that plasma-labelled platelets display a normal initial bio-distribution, mean intrahepatic platelet transit time, as a factor of the transit time of 99m-Tc labelled red cells, was 1.45 ± SE 0.12 (n = 6), implying the normal presence of a small intrahepatic platelet pool. Unlike the liver, transit through the spleen was not sensitive to the labelling medium; thus the mean intrasplenic transit time of plasma-labelled platelets was 9.3 ± SE 0.7 min (n = 10), and of saline-labelled platelets 9.5 ± SE 0.3 min (n = 8).
Aspirin and the Prevention of Experimental Arterial Thrombosis: Difficulty in Establishing Unequivocal Effectiveness
Authors: Reyers Ine , Hennissen Adje , Donati Maria Benedetta , Hornstra Gerard , de Gaetano Giovanni
Published: July 2018

A trial of the efficacy of aspirin in the prevention of thrombotic occlusion of an “aortic loop” in rats was made simultaneously by two experimental surgeons. A relatively large dose of aspirin (80-100 mg/kg/day) was used, starting two days before operation. It appeared that aspirin was of limited benefit, reducing thrombotic occlusions by about 17% seven days after the insertion of the loop into the abdominal aorta. Although the average occlusion time was prolonged by about 17% in aspirin-treated animals, the separate trials gave no conclusive result. When the data from both operators were pooled, a statistically significant protection by aspirin was apparent (p = 0.02), by a two-tailed Student’s t test. However, on using the powerful non-parametric randomization test, the occlusion times in control and aspirin-treated groups appeared not statistically different (p = 0.07). No significant difference was also found between control and treated groups when data were analyzed by X2 test. Independently of the statistical analysis, these data are quite similar to those obtained from aspirin trials in men surviving myocardial infarction. This finding points to the usefulness of the aorta loop as an animal model for arterial thrombosis.
Plasma Fibronectin Enhances Fibrinolytic System In Vitro
Authors: Gilboa Nisan , Kaplan John E
Published: July 2018

The effects of plasma fibronectin on the fibrinolytic system were studied in vitro. Fibronectin caused a time and concentration-dependent increase (up to 99% with 330 ug/ml) in the amidolytic activity of tissue plasminogen activator (TPA) but not of urokinase. In the presence of fibronectin the Km of the amidolytic activity of TPA decreased without a change in Vmax. It also caused a concentration-dependent increase in lys-plas-minogen activation by TPA (up to 825% with 375 ug/ml) and by urokinase (up to 400% with 250 ug/ml), as well as in the amidolytic activity of plasmin (up to 55% with 300 ug/ml). Fibronectin did not enhance the activation of glu-plasminogen. In the presence of fibronectin the Km of lys-plasminogen activation decreased without a change in Vmax. In purified systems fibronectin significantly shortened the clot lysis time (CLT) by up to 28% and 30% in TPA- and plasmin-activated lysis, respectively. The presence of Ca2+ did not change fibronectin’s effect on CLT. Clots of non-fibronectin-depleted plasma were lysed up to about twice as fast as the clots of fibronectin-depleted plasma. In conclusion, physiologic concentrations of fibronectin enhanced the fibrinolytic system in vitro. Further studies will be required to elucidate the mechanisms involved and to document whether fibronectin has a similar effect in vivo.
Standardization of Low Molecular Weight Heparins : A Collaborative Study
Authors: Barrowcliffe T W , Curtis A D , Tomlinson T P , Hubbard A R , Johnson E A , Thomas D P
Published: July 2018

A collaborative study was carried out, in which eight laboratories each assayed eight low molecular weight (LMW) heparins against the International Standard (IS) for heparin. APTT assays and three types of anti-Xa method were used. The results of this study showed that:

1. LMW heparins cannot be validly assayed against the IS by APTT or anti-Xa methods.

2. Potencies of LMW heparins vs. the IS differed considerably between the four types of assay method used and also between different laboratories using the same type of method.

3. Adoption of a single LMW heparin standard would improve validity, improve inter-laboratory variation, and largely abolish the differences between the three types of anti-Xa method. However, since calibration of a LMW heparin standard against the IS would give potencies that differ widely by the different assay methods, a single assay method such as the anti-Xa amidolytic, plasma, would need to be chosen for this calibration.
Synergism between Thrombin and Epinephrine in Human Platelets: Different Dose-Response Relationships for Aggregation and Dense Granule Secretion
Authors: Steen Vidar M , Holmsen Holm
Published: July 2018

Synergism between epinephrine and thrombin in human gel-filtered platelets was studied. Suspensions of platelets, which did not contain added fibrinogen, were incubated at 37° C to measure aggregation and dense granule secretion after stimulation. Both aggregation and secretion induced with 0.03-0.3 U/ml of thrombin were markedly potentiated by epinephrine (0.5-4 ҼM), which alone was without effect. Addition of epinephrine before stimulation with thrombin resulted in a marked decrease in the concentration of thrombin required for half-maximal aggregation, without affecting the maximal aggregation response. The dose-response relationship for dense granule secretion was affected in a similar way with regard to the half-maximal response; in addition, epinephrine slightly increased maximal secretion response. However, the concentration range for thrombin at which synergism occurred was distinctly lower for aggregation than for secretion. Our observations suggest that aggregation and dense granule secretion are separate steps in the sequence of stimulus-response coupling, and suggest distinct thresholds of intracellular messengers for these different responses.
Prothrombin Time Proficiency Testing: A Robust Grading Method
Authors: Han Yangsook , Lawson William B , Jean Dodds W , Lawrence Charles E
Published: July 2018

A robust two-way analysis of variance technique was applied to determine simultaneously the effects of method and thromboplastin on prothrombin time. A new approach to outlier detection for two-way analysis of variance was used. Focusing on the underlying error structure improved the uniformity of the grading procedure in the hematology proficiency testing program of the New York State Department of Health.

The logarithm-transformed scale produced constancy of error variance and resulted in uniformity of the acceptable spread of data. The common variance was lower than that obtained by previous methods and allowed for a narrower acceptable range of reported prothrombin times by reducing the inflated standard deviation, thus improving the efficiency of the grading procedure.

For proficiency testing, no advantage was found in the use of either a common thromboplastin or freeze-dried, coumadinized patient plasmas rather than artificially depleted commercial plasmas, except for special purposes.
Postoperative Changes in the Plasmatic Levels of Tissue-Type Plasminogen Activator and Its Fast-Acting Inhibitor - Relationship to Deep Vein Thrombosis and Influence of Prophylaxis
Authors: Páramo J A , Alfaro M J , Rocha E
Published: July 2018

Fibrinogen, euglobulin lysis time (ELT), tissue-type plasminogen activator (t-PA) antigen, plasminogen activator inhibitor activity (PA-inhibitor) and α2-antiplasmin (a2-AP) were measured pre- and postoperatively in 60 patients undergoing total hip replacement. Reduced fibrinolytic activity as assessed by the prolongation of euglobulin lysis time, decrease of t-PA and increase of PA-inhibitor and β2-AP could be demonstrated. These changes did not correlate with the postoperative deep vein thrombosis (DVT) diagnosed with the 125I-fibrinogen test. However, preoperative PA-inhibitor activity was significantly higher in patients with postoperative DVT (p <0.01). The prophylactic treatment with aspirin (20 patients) and with heparin plus dihy-droergotamine (20 patients) induced significant changes in some of those parameters.

This study shows that the decrease of t-PA and the increase of PA-inhibitor may contribute to the reduced postoperative fibrinolytic activity after total hip replacement. PA-inhibitor level might be a useful marker in evaluating the risk of developing DVT in patients undergoing total hip replacement.
Human Leucocyte Urokinase Inhibitor - Purification, Characterization and Comparative Studies Against Different Plasminogen Activators
Authors: Kopitar M , Rozman B , Babnik J , Turk V , Mullins D E , Wun T C
Published: July 2018

A plasminogen activator inhibitor (PA-I) which inhibits primarily plasminogen activator of the urokinase type (u-PA) was isolated from the cytosol of human peripheral leukocytes. The inhibitor was isolated using ion exchange chromatography, gel filtration and FPLC. This inhibitor has an apparent molecular weight of 45 kDa, determined by SDS-PAGE, and a pi of 5.5-5.7. The inhibitor is a fast reacting inhibitor, is thermally unstable and is inactivated outside the pH range 7-9. Treatment of cytosol to pH 9 for 30 min at 37° C resulted in a large increase in inhibitory activity. Antibodies against human placental UK-I completely quenched the inhibitory activity of human leucocyte UK-I.
Evidence for a Direct Effect on Vascular Permeability of Platelet-Activating Factor Induced Hemoconcentration in the Guinea Pig
Authors: Handley Dean A , Lee Mark L , Saunders Robert N
Published: July 2018

The ability of synthetic platelet-activating factor (PAF) given intravenously to produce loss (extravasation) of protein rich plasma (resulting in hemoconcentration) has been examined using guinea pigs. Hemoconcentration induced by PAF was not prevented by prior administration of inhibitors of thromboxane synthetase (7-(3-pyridyl)heptanoic acid, UK-37,248-01), PGI2, aspirin, indomethacin or antiserum induced thrombocytopenia. Calcium channel blockers (nifedipine, verapamil, diethyl-amino octyltrimethoxybenzoate, diltiazem), antihistamines (pyrilamine, cimetidine, diphenhydramine), or the elevator of cAMP IBMX were ineffective in blocking PAF-induced hemoconcentration. In contrast, CV-3988, reported to be a specific antagonist to PAF, was 98% inhibitory of PAF extravasation when given i. a. at 3.5 mg/kg. The ED50 was 0.14 mg/kg I. A. and 15 mg/kg p.o. against 75 ng/kg PAF. These data suggest that PAF-induced hemoconcentration involves receptor mediated alterations of vascular permeability that are inhibited by a specific PAF antagonist.
Platelet Function in Surgical Stress
Authors: Naesh O , Friis J T , Hindberg I , Winther K
Published: July 2018

Ten patients for elective cholecystectomy were studied pre-, per- and postoperatively. All had neurolept anesthesia. Plasma concentrations of β-TG, TXB2 and 5-HT and intraplatelet 5-HT were measured. Aggregation to ADP was recorded.

Serum cortisol concentration was used as index of the stress response, showing peroperative increase and postoperative decrease. Closely related to this we observed a significant increase in P-β-TG and P-TXB2 with postoperative normalization in 6 patients without complications. P-5-HT had a peak peropera-tively and remained elevated postoperatively. A negative correlation between P--5-HT and decreasing intraplatelet 5-HT postoperatively was observed.

High postoperative levels of P--5-HT seem to be related to low arterial Po2 and pulmonary dysfunction. In 3 patients with complications a second increase in P-β-TG, P-TXB2 and partly in P--5-HT was found. Platelets were temporarily refractory to ADP immediately following surgery and showed increased aggregabil-ity postoperatively. We conclude that platelets are activated in surgical stress.
Multicenter Comparison of von Willebrand Factor Multimer Sizing Techniques
Authors: Mannucci P M , Abildgaard C F , Gralnick H R , Hill F G H , Hoyer L W , Lombardi R , Nilsson I M , Tuddenham E , Meyer D
Published: July 2018

A multicenter study of various types of von Willebrand’s disease (vWD) was conducted in order to compare the different electrophoretic techniques used to evaluate von Willebrand factor multimers in plasma. Seven laboratories participated in the blind study of eight plasma samples from two healthy subjects and six vWD types and subtypes (la, lb, IIA, IIB, IIC and IID). From the results of the multimeric analysis of these samples, it appears that the differential diagnosis of vWD types and subtypes should be first approached by using a low-resolution electrophoretic technique, where each vWF multimer appears as a single band. Low-resolution techniques differentiate type I from type II, subtype la from lb and also subtype IIA from other type II subtypes. When type II subtypes other than IIA are identified with these techniques, samples should be rerun using high resolution techniques that resolve each of the fastest migrating multimers in at least three subbands, and permit the differentiation of subtypes IIB, IIC and IID.
Interactions Between Ethanol and Dietary Fat in Determining Human Platelet Function
Authors: Fenn Christopher G , Littleton John M
Published: July 2018

Platelet aggregation to collagen and ADP in vitro was assessed in the plasma of healthy human volunteers both before and after drinking 700 ml of white wine. This had no effect on platelet aggregation when compared with samples from the same individuals taken on a separate occasion without alcohol consumption. However, when alcohol was taken with a meal high in saturated fat, a significant inhibitory effect on platelet aggregation was observed when compared to the effect of the meal alone. There was no such interaction when the meal associated with alcohol ingestion contained mainly unsaturated fats. The fatty acid composition of plasma and platelet membranes from these volunteers showed a significantly increased proportion of saturated fats after the saturated fat meal. The concomitant ingestion of ethanol did not prevent this change. The concentration of alcohol in plasma achieved (c. 25 mM) may directly inhibit platelet aggregation when the platelet membrane content of saturated fats is high.
A Study of the Possible Role of Mesothelium as a Surface for Flowing Blood
Authors: Clarke J M F , Pittilo R M , Machin S J , Woolf N
Published: July 2018

Mouse mesothelium has been examined as a surface for supporting blood flow. We have examined ten pieces of intact mesothelium and ten pieces of damaged mesothelium following 10 min exposure to flowing blood in a Baumgartner chamber. Scanning electron microscopy of the intact specimens demonstrated no adhering blood platelets, whereas the damaged specimens were found to be covered with large numbers of adhering platelets. In addition we have demonstrated that undamaged mesothelium does not appear to be morphologically altered after exposure to blood, and that undamaged mesothelium produces significantly more prostacyclin than damaged control. These findings suggest that mesothelial cells hold promise as a lining for prosthetic vascular implants.
Plasma Contact Activation and Decrease of Factor V Activity on Negatively-Charged Polyelectrolytes
Authors: Boffa M C , Dreyer B , Pusineri C
Published: July 2018

The effect of negatively-charged polymers, used in some artificial devices, on plasma clotting and kinin systems was studied in vitro using polyelectrolyte complexes.

Contact activation was observed as an immediate, transient and surface-dependent phenomenon. After incubation of the plasma with the polymer a small decrease of factor XII activity was noticed, which corresponded to a greater reduction of prekallikrein activity and to a marked kinin release. No significant decrease of factor XII, prekallikrein, HMW kininogen could be detected immunologically. Only the initial contact of the plasma with the polyelectrolyte lead to activation, subsequently the surface became inert.

Beside contact activation, factor V activity also decreased in the plasma. The decrease was surface and time-dependent. It was independent of contact factor activation, and appeared to be related to the sulfonated groups of the polymer. If purified factor V was used instead of plasma factor V, inactivation was immediate and not time-dependent suggesting a direct adsorption on the surface. A second incubation of the plasma-contacted polymer with fresh plasma resulted in a further loss of Factor V activity.
Medial Smooth Muscle Cell Proliferation in the Balloon Injured Rabbit Aorta: Effect of a Thiazole Compound with Platelet Inhibitory Activity
Authors: Schaub R G , Simmons C A
Published: July 2018

Twenty-seven adult male New Zealand rabbits (3–4 kgs) were used in this study. Six rabbits received vehicle, 3 groups of 6 each received doses of 4,5-bis(p-methoxyphenyl)-2-(trifluoromethyl)- thiazole, (U-53,059), at 0.3 mg/kg, 3.0 mg/kg and 30.0 mg/kg/day respectively. Drug and vehicle doses were given orally each day starting 3 days before balloon injury and continuing for the entire 2 week time period. Three rabbits were used as nontreated sham controls. In the vehicle and U-53,059 treated groups aortae were denuded of endothelial cells by balloon catheter injury. Two weeks after injury platelet aggregation to collagen was measured and the aortae removed for analysis of surface characteristics by scanning electron microscopy and lesion size by morphometry. All doses of U-53,059 inhibited platelet aggregation. The 3.0 and 30.0 mg/kg groups had the greatest inhibitory effect. All balloon injured aortae had the same morphologic characteristics. All vessels had similar extent and intensity of Evan’s blue staining, similar areas of leukocyte/platelet adhesion, and a myointimal cell cover of transformed smooth muscle cells. The myointimal proliferative response was not inhibited at any of the drug doses studied.
Plasma and Platelet Fibrinogen Differ in γ Chain Content
Authors: Francis Charles W , Nachman Ralph L , Marder Victor J
Published: July 2018

The polypeptide chain composition of fibrinogen and cross- linked fibrin from normal platelets and plasma has been compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Fibrinogen was prepared from a lysate of normal human platelets by ethanol precipitation and by antifibrinogen immunoaffinity chromatography. While the Aα chains of platelet fibrinogen appeared to be somewhat degraded, the electrophoretic mobilities of purified platelet and plasma fibrinogen Bβ an γ chains were the same. Crosslinked fibrin was prepared from platelet and plasma fibrinogen and γ chain dimers identified by their electrophoretic mobility, incorporation of the lysine analog dansyl cadaverine during crosslinking, and by reaction with antifibrinogen antibody in Western blots. Platelet crosslinked fibrin had a different polypeptide chain composition than that of plasma crosslinked fibrin with absence of the γ50–γ57.5 dimer in the platelet fibrin. This finding indicates that the γ57.5 chain, which constitutes 5% of total normal plasma fibrinogen γ chains, is either absent or present in markedly reduced amounts in platelet fibrinogen.