bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acceleration of apatite nucleation on microrough bioactive titanium for bone‐replacing implants
Authors: Aparicio C. , Manero J.M. , Conde F. , Pegueroles M. , Planell J.A. , Vallet‐Regí M. , Gil F.J. 
Published: February 2007

AbstractThe viability of a new two‐step method for obtaining bioactive microrough titanium surfaces for bone replacing implants has been evaluated. The method consists of (1) Grit blasting on titanium surface to roughen it; and (2) Thermo‐chemical treating to obtain a bioactive surface with bone‐bonding ability by means of nucleating and growing an apatite layer on the treated surface of the metal. The aim of this work is to evaluate the effect of surface roughness and chemical composition of the grit‐blasting particles on the ability of the surfaces of nucleating and growing a homogeneous apatite layer. The determination and kinetics of the nucleation and growing of the apatite layer on the surfaces has mainly been studied with environmental scanning electron microscopy (ESEM) and grazing‐incidence X‐ray diffractometry. The results show that Al2O3‐blasted and thermochemically‐treated titanium surfaces accelerates nucleation of the apatite, whereas SiC‐blasted and thermochemically‐treated titanium surfaces inhibits apatite nucleation, compared with the well studied polished and thermochemically‐treated titanium surfaces. The acceleration of the apatite nucleation on the Al2O3‐blasted microrough titanium surfaces is because concave parts of the microroughness that are obtained during grit blasting provides to the rough and bioactive surfaces with a chemical‐ and electrostatic‐favored situation for apatite nucleation. This consists of a high density of surface negative charges (also assisted by the nanoroughness of the surface obtained after the thermochemical treatment) and an increased concentration of the Ca2+‐ions of the fluid, which have a limited mobility at the bottom of the concave parts. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Phagocyte responses to degradable polymers
Authors: Jiang Wei‐Wu , Su Shih‐Horng , Eberhart Robert C. , Tang Liping 
Published: February 2007

AbstractAlthough many biodegradable polymers, such as poly‐L‐lactic acid and poly‐L‐glycolic acid, are preferentially composed of biological residues normally present in the human body, implants made of these materials often trigger inflammatory and fibrotic responses. Unfortunately, the mechanisms involved in degradable material‐mediated tissue responses remain largely unknown. Using animal implantation and cell culture system models, we found a strong correlation between the rate of material degradation and the degree of inflammatory response to material implants. Furthermore, we have identified that both water‐soluble and water‐insoluble degradation products are potent triggers of phagocyte activation, including at the least, superoxide production. These results support a new concept that slow degradation may improve the biocompatibility of degradable drug‐releasing particles and tissue engineering scaffolds. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Phenotypic expression of human hepatoma cells in culture
Authors: Cutroneo Kenneth R. , White Sheryl L. , Buttolph Thomas R. , Allison Gretchen , Ehrlich H. Paul 
Published: February 2007

AbstractHepatomas thrive in a hypoxic environment resulting in the induction of a cluster of hypoxia related genes. The protein phenotypic expression include hypoxia inducible factor‐α, prolyl‐4‐hydroxylase, vascular endothelear growth factor and erythropoietin. The present study was undertaken to determine if human hepatoma cells when cultured for 72 h in the presence of serum under normoxia would maintain their cancerous phenotypic expression of certain hypoxia inducible genes. Our positive results affords an in vitro model system to test hypoxia inhibitors on the expression and the intracellular compartmentalization or the secretion of these hypoxia‐inducible proteins. J. Cell. Biochem. 100: 1081–1085, 2007. © 2007 Wiley‐Liss, Inc.
Towards in situ tissue repair: Human mesenchymal stem cells express chemokine receptors CXCR1, CXCR2 and CCR2, and migrate upon stimulation with CXCL8 but not CCL2
Authors: Ringe Jochen , Strassburg Sandra , Neumann Katja , Endres Michaela , Notter Michael , Burmester Gerd‐Rüdiger , Kaps Christian , Sittinger Michael 
Published: February 2007

AbstractThe recruitment of bone marrow CD34−mesenchymal stem‐ and progenitor cells (MSC) and their subsequent differentiation into distinct tissues is the precondition for in situ tissue engineering. The objective of this study was to determine the entire chemokine receptor expression profile of human MSC and to investigate their chemotactic response to the selected chemokines CCL2, CXCL8 and CXCL12. Human MSC were isolated from iliac crest bone marrow aspirates and showed a homogeneous population presenting a typical MSC‐related cell surface antigen profile (CD14−, CD34−, CD44+, CD45−, CD166+, SH‐2+). The expression profile of all 18 chemokine receptors was determined by real‐time PCR and immunohistochemistry. Both methods consistently demonstrated that MSC express CC, CXC, C and CX3C receptors. Gene expression and immunohistochemical analysis documented that MSC express chemokine receptors CCR2, CCR8, CXCR1, CXCR2 and CXCR3. A dose‐dependent chemotactic activity of CXCR4 and CXCR1/CXCR2 ligands CXCL12 and CXCL8 (interleukin‐8) was demonstrated using a 96‐well chemotaxis assay. In contrast, the CCR2 ligand CCL2 (monocyte chemoattractant protein‐1, MCP‐1) did not recruited human MSC. In conclusion, we report that the chemokine receptor expression profile of human MSC is much broader than known before. Furthermore, for the first time, we demonstrate that human MSC migrate upon stimulation with CXCL8 but not CCL2. In combination with already known data on MSC recruitment and differentiation these are promising results towards in situ regenerative medicine approaches based on guiding of MSC to sites of degenerated tissues. J. Cell. Biochem. 101: 135–146, 2007. © 2007 Wiley‐Liss, Inc.
Alternative production of Bcl‐2 and Bax by tumor cells determines the rates of in vivo tumor progression: Suggested mechanisms
Authors: Deichman Galina I. , Dyakova Natalya A. , Matveeva Valentina A. , Kashkina Lydia M. 
Published: February 2007

AbstractThe hypothesis tested in the study suggests that mechanisms of the earlier described delayed or accelerated tumor progression may be regulated by the antiapoptotic and proapoptotic cellular programs activated in stress reactions of transformed cells to the host normal cellular environment. Therefore, spontaneously transformed hamster cell line STHE, its bcl‐2‐transduced line STHE‐Bcl‐2, and 64 of their descendant tumor cell variants naturally selected in two in vivo regimes (local tumor growth versus dissemination) were examined. The role of Bcl‐2 and the possible activation of endogenous death‐signaling Bax, Ras, and HSP90/HSP70 stress proteins in STHE (Bcl‐2+/−) tumor cell variants were studied in dynamics of in vivo tumor progression. The data demonstrate: (1) Immediate in vivo activation of Bax and of HSP90/HSP70 stress proteins in disseminated STHE cells on the background of accelerated tumor progression; (2) No immediate activation of Bax and the gradual downregulation of Bcl‐2 in STHE‐Bcl‐2 cells on the background of delayed tumor progression; (3) Alternative and mutually suppressive character of Bcl‐2 and Bax expression in both regimes of tumor progression; (4) In the later stages of tumor progression, the regular transit of the initial Bcl‐2 antiapoptotic, Bax‐suppressing program, and the delayed tumor progression towards Bcl‐2 loss, activation of Bax, and acceleration of tumor progression. Thus, the delay of tumor progression is apparently determined by the ability of Bcl‐2‐expressing tumor cells to extinguish the cell‐damaging environmental stress signals and Bax activation, while its acceleration correlates with Bcl‐2 loss, activation of proapoptotic Bax, and tumor cells damage. J. Cell. Biochem. 101:1148–1164, 2007. © 2007 Wiley‐Liss, Inc.
Cytoskeleton/stretch‐activated ion channel interaction regulates myogenic differentiation of skeletal myoblasts
Authors: Formigli Lucia , Meacci Elisabetta , Sassoli Chiara , Squecco Roberta , Nosi Daniele , Chellini Flaminia , Naro Fabio , Francini Fabio , Zecchi‐Orlandini Sandra 
Published: February 2007

AbstractIn the present study, we investigated the functional interaction between stress fibers (SFs) and stretch‐activated channels (SACs) and its possible role in the regulation of myoblast differentiation induced by switch to differentiation culture in the presence or absence of sphingosine 1‐phosphate. It was found that there was a clear temporal correlation between SF formation and SAC activation in differentiating C2C12 myoblasts. Inhibition of actin polymerization with the specific Rho kinase inhibitor Y‐27632, significantly decreased SAC sensitivity in these cells, suggesting a role for Rho‐dependent actin remodeling in the regulation of the channel opening. The alteration of cytoskeletal/SAC functional correlation had also deleterious effects on myogenic differentiation of C2C12 cells as judged by combined confocal immunofluorescence, biochemical and electrophysiological analyses. Indeed, the treatment with Y‐27632 or with DHCB, an actin disrupting agent, inhibited the expression of the myogenic markers (myogenin and sarcomeric proteins) and myoblast‐myotube transition. The treatment with the channel blocker, GdCl3, also affected myogenesis in these cells. It impaired, in fact, myoblast phenotypic maturation (i.e., reduced the expression of α‐sarcomeric actin and skeletal myosin and the activity of creatine kinase) but did not modify promoter activity and protein expression levels of myogenin. The results of this study, together with being in agreement with the general idea that cytoskeletal remodeling is essential for muscle differentiation, describe a novel pathway whereby the formation of SFs and their contraction, generate a mechanical tension to the plasma membrane, activate SACs and trigger Ca2+‐dependent signals, thus influencing the phenotypic maturation of myoblasts. J. Cell. Physiol. 211: 296–306, 2007. © 2007 Wiley‐Liss, Inc.
Extracellular nucleotides regulate CCL20 release from human primary airway epithelial cells, monocytes and monocyte‐derived dendritic cells
Authors: Marcet Brice , Horckmans Michael , Libert Frédérick , Hassid Sergio , Boeynaems Jean‐Marie , Communi Didier 
Published: February 2007

AbstractExtracellular nucleotides regulate ion transport and mucociliary clearance in human airway epithelial cells (HAECs) via the activation of P2 receptors, especially P2Y2. Therefore, P2Y2receptor agonists represent potential pharmacotherapeutic agents to treat cystic fibrosis (CF). Nucleotides also modulate inflammatory properties of immune cells like dendritic cells (DCs), which play an important role in mucosal immunity. Using DNA‐microarray experiments, quantitative RT‐PCR and cytokine measurements, we show here that UTP up‐regulated ∼2‐ to 3‐fold the antimicrobial chemokine CCL20 expression and release in primary HAECs cultured on permeable supports at an air–liquid interface (ALI). Both P2Y2(ATPγS, UTP, INS365) and P2Y6(UDP, INS48823) agonists increased CCL20 release. UTP‐induced CCL20 release was insensitive to NF‐κB pathway inhibitors but sensitive to inhibitors of ERK1/2 and p38/MAPK pathways. Furthermore, UTP had no effect on interleukin‐(IL)‐8 release and reduced the release of both CCL20 and IL‐8 induced by TNF‐α and LPS. Accordingly, UTP reduced the capacity of basolateral supernatants of HAECs treated with TNF‐α or LPS to induce the chemoattraction of both CD4+T lymphocytes and neutrophils. In addition, we show that, in monocyte‐derived DCs, ATPγS, and UDP but not UTP/INS365‐stimulated CCL20 release. Likewise, UDP but not ATPγS was also able to increase CCL20 release from monocytes. Pharmacological experiments suggested an involvement of P2Y11or P2Y6receptors through NF‐κB, ERK1/2, and p38/MAPK pathways. Altogether, our data demonstrate that nucleotides may modulate chemokine release and leukocyte recruitment in inflamed airways by acting on both epithelial and immune cells. Our results could be relevant for further clinical investigations in CF. J. Cell. Physiol. 211: 716–727, 2007. © 2007 Wiley‐Liss, Inc.
Sonographic detection of indian grass (Sorghastrum nutans), an unusual foreign body, in the urinary bladder
Authors: Taori Kishor , Saha Bimal , Shah Deepal , Khadaria Narottam , Sanyal Rupan , Jawale Rajesh , Jadhav Vijay 
Published: February 2007

AbstractA variety of foreign bodies have been described in the urinary bladder. These bodies are usually found in patients who have a psychiatric disorder with a sexual perversion or inquisitiveness (as in children) as the underlying cause. We report a case of Indian grass inserted into the urinary bladder by an adult male that was detected on sonography and subsequently removed successfully via surgery. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
Coprecipitation with calcium hydroxide for determination of iron in fish otoliths by collision cell ICP‐MS
Authors: Daniels Stephanie L. , Arslan Zikri 
Published: February 2007

AbstractA method has been described for the determination of iron from fish otoliths containing high levels of calcium by collision cell technology (CCT) ICP‐MS. Iron (Fe) in otolith solutions was quantitatively coprecipitated with small amounts of calcium hydroxide by adding 1.0 M sodium hydroxide solution. The performance of CCT‐ICP‐MS pressurized with He/H2 cell gas was investigated on the elimination of Ca‐based spectral interferences at m/z 54, 56 and 57. Molecular ion interferences at m/z 54 and 56 were reduced by 2 orders of magnitude. However, the interferences at m/z 57 increased by the same amount in the presence of Ca in solutions owing to the formation of 40Ca16 OH+ through reactions with H2 in collision cell, indicating that 57Fe was not suitable for the determination of Fe from otoliths. Results for 56Fe suffered significantly from interferences of Ca‐based molecular ions when the Ca concentration in solution exceeded 100 µg ml−1, for which matrix‐matched calibration was required for accurate determination. CCT with the aid of He/H2 cell gas proved to be very effective in eliminating the interferences (40Ar14N+ and 40Ca14N+) at m/z 54. Presence of Ca up to 300 µg ml−1 had virtually no effect on the ion signals of 54Fe, which with low background signals, afforded accurate determination of Fe from otoliths by using aqueous external standards. Copyright © 2007 John Wiley & Sons, Ltd.
Beste Sicht dank schnellem Licht – Femtosekundenlaser für die Hornhautchirurgie des 21. Jahrhunderts
Authors: Loesel Frieder 
Published: February 2007

AbstractLaser haben die Augenheilkunde in den letzten Jahrzehnten stark beeinflusst. Mit den Lichtstrahlen wird unter anderem die Netzhaut schonend von außen therapiert, mittels Wellenfrontverfahren werden Abbildungsfehler des Auges höchst präzise und objektiv erfasst, und UV‐Laser formen die Krümmung der Hornhaut neu, um Fehlsichtigkeiten dauerhaft zu korrigieren. Nun tritt der Femtosekundenlaser an, die Ophthalmologie erneut zu revolutionieren. Ein “kalt” wirkender ultraschneller Laserstrahl, der beliebig innerhalb des Gewebes schneiden und ablatieren kann. Ein Laserskalpell, das keinen mechanischen Limitierungen mehr unterliegt und komplexe, auch dreidimensionale Schnittführungen erlaubt. Ein minimal‐invasives chirurgisches Werkzeug, dessen Anwendungsvielfalt nur durch die Vorstellungskraft des Operateurs begrenzt sein wird.
Kompakte Femtosekunden‐Halbleiterlaser – Es zählen auch Zuverlässigkeit und Preis
Authors: Wallenstein Richard 
Published: February 2007

AbstractIm Jahre 1962 emittierte der erste Halbleiterlaser auf der Basis eines Gallium‐Arsenid‐Kristalls kohärentes Licht. Seit dieser Zeit haben Generationen von Halbleiterlasern mit immer komplexeren Strukturen und verbesserten Eigenschaften einander abgelöst. Massenanwendungen in optischer Nachrichtenübertragung und CD‐/DVD‐Laufwerken führten zu einer starken Reduzierung der Herstellungskosten. Dadurch erschlossen sich für diese Laser neue Anwendungsfelder, die zunächst anderen Laserarten vorbehalten waren.
Charakterisierung von Laseroptiken für die Femtonik – Standardmessverfahren im Überblick
Authors: Starke Kai 
Published: February 2007

AbstractDie Evolution von Lasersystemen zur Erzeugung ultrakurzer Pulse von ersten Laborstudien bis hin zu kompakten, leistungsfähigen und industrietauglichen Turn‐Key‐Systemen kann unbestritten als Erfolgsgeschichte bezeichnet werden. In jüngster Vergangenheit sind mit Hilfe wartungsarmer Tischgeräte zahlreiche Anwendungen in der Mikromaterialbearbeitung, der Medizin, der zeitaufgelösten Analytik und der physikalischen Grundlagenforschung erstmals möglich geworden.
Good News!
Authors: Thoß Andreas , Kock Holger 
Published: February 2007

AbstractNow, with the old year fading, the first prognoses for the economic development come up. And the numbers look good: Arnold Mayer from Optech Consulting sees a new all time high in the market for laser materials systems with sales at 5.91 billion USD in 2005. After a decline between 2000 and 2003 the market has now recovered and further growth is expected (see p. 11 for more information). One big issue in the foreseeable future will be the development of new markets, particularly in Asia. Here in Europe, everybody is looking at China. In December 2005, a 10 billion Dollar deal with Chinese authorities was announced by Airbus. Just two weeks earlier, Boeing received an order over 4 billion USD from China. It looks as if the Chinese dragon is taking off. But how look things in the laser business? How does China compare with the established high tech markets in Asia? And how many domestic products are coming up? To answer all these questions we have prepared a special report on the Chinese laser market in this issue (page 12).Although Asia may be on the rise, Europe is still playing a leading part in the development of laser technology. It has an excellent structure for basic research and a number of companies making successful products on the basis of academic findings. This is particularly true for Germany with laser companies such as Trumpf or Rofin Sinar, which lead their markets for many years. On the other side, German universities are more and more suffering from budget cuts. The new German government has promised to raise funding but there is no agenda yet. More activity is going on at the European arena at the moment. On December 2nd, a new platform “Photonics21” has been founded in Brussels. Lead by the chairmen of companies like Jenoptik, Bookham, TRUMPF Lasertechnik, Carl Zeiss, Philips Lighting, SAGEM, this platform will formulate a European agenda for photonics and advise the European Commission for the next big funding plan, the 7. Framework Programme of the European Commission. FP 7 is valid for seven years and has a total funding budget of 72 billion Euro.Thinking about the use of lasers in industry you can generally distinguish between the processing tool and the device for measurement. In this issue we will focus on the latter one. After some decades of development of laser based measurement, technologies have become very diverse and it is even difficult to cover them by a single headline. Therefore it is very appropriate when Gerd Häusler and his co‐authors named their article “3D sensor zoo”. Nevertheless, holographic and interferometric techniques have become mature and found a widespread use from automotive industry to plastic surgery (p. 42), and all the issues of homeland security will further boost this fast and precise technology.
Online Qualitätssicherung an Laserverbindungen in der Automobilindustrie
Authors: Jäckel Torsten 
Published: February 2007

AbstractSeit dem Jahr 2000 setzt die Volkswagen AG im großen Umfang, lasergestützte Verbindungstechniken im Karosseriebau ein. Die Steigerung der Schweiß‐ und Lötverbindungen nahm mit dem Polo, über den Touran, den Golf und dem aktuellen Passat deutlich zu. Im aktuellen Golf sind rund 50 m Laserschweißnaht zu finden. Die Schweißnähte sind alle als Überlappverbindung ausgelegt. Trotz des weiten Parameterfensters und der Sicherheit der Schweißprozesse, ist eine kontinuierliche Kontrolle der Verbindungsqualität nötig. Am Markt sind Systeme erhältlich, die die Prozesse automatisch überwachen und im Fehlerfall eingreifen können. Trotzdem sind in der Fertigung nur wenige dieser Systeme im Einsatz, da hier das Angebot der Qualitätssensoren, die tatsächlichen Bedürfnisse der Automobilhersteller noch nicht befriedigt.
Morphology, Thermal Stability, and Mechanical Behavior of [Poly(propylene)‐grafted Maleic Anhydride]‐Layered Expanded Graphite Oxide Composites
Authors: Cerezo Frances T. , Preston Christopher M. L. , Shanks Robert A. 
Published: February 2007

AbstractPP‐g‐MA‐layered EGO composites were prepared directly by solution blending. Two types of PP‐g‐MA/EGO composites were prepared using different mixing methods: distributive and dispersive. In this study, the effects of the mixing method of EGO on the crystalline structure and thermo‐mechanical properties of PP‐g‐MA/EGO composites are reported. WAXD exhibited a shift in 2θ of the monoclinic (α) phase of PP‐g‐MA and (002) EGO peaks for PP‐g‐MA/EGO layered composites, which indicated a modification of the crystalline structure of PP‐g‐MA in the layered composites. DSC exhibited a single characteristic melting peak of monoclinic (α) crystalline phase PP‐g‐MA. The incorporation of EGO increased Tc indicating that the EGO acted as a nucleating agent for PP‐g‐MA. The crystallinity of the PP‐g‐MA/EGO composites was found to be dependent on the mixing method. Thermogravimetry demonstrated that PP‐g‐MA in the presence of EGO has higher degradation temperature, suggesting that the graphite particles acted as a thermal barrier material for PP‐g‐MA. DMA indicated that incorporation of EGO into PP‐g‐MA increased the storage modulus, due to the hydrogen bonding between EGO and MA of PP‐g‐MA.magnified image
Temperature and pH‐Sensitive Swelling Behavior of Binary DMAEMA/4VP Grafts on Poly(propylene) Films
Authors: Burillo Guillermina , Bucio Emilio , Arenas Ever , Lopez Gabriel P. 
Published: February 2007

AbstractPoly(N,N‐dimethylaminoethyl methacrylate) (PDMAEMA) is a polymer or hydrogel that is both thermosensitive and pH sensitive, with a low critical solution temperature (LCST) around 38 °C and a pH critical point of 2.5. Poly(4‐vinylpyridine) (P4VP) shows pH sensitivity with a critical point of 5.1. Grafting of stimuli‐sensitive polymers onto mechanically durable poly(propylene) (PP) substrates was used in this study. We have focused on the influence of temperature and pH on the response of binary graft films produced by gamma irradiation in one and two steps. An LCST‐type hydration transition in the grafts was observed by measuring swelling of the films and water contact angle at different temperatures and pH. An upper critical solution temperature (UCST)‐type behavior was also observed by swelling PP‐g‐DMAEMA and DMAEMA/4VP binary grafting onto PP films at pH 2.2.magnified image