bluuebunny/crossref_metadata_2025 huggingface dataset:
Increase in hemokinin‐1 mRNA in the spinal cord during the early phase of a neuropathic pain state
Authors: Matsumura T , Sakai A , Nagano M , Sawada M , Suzuki H , Umino M , Suzuki H
Published: July 2008

Background and purpose:

Substance P (SP), a representative member of the tachykinin family, is involved in nociception under physiological and pathological conditions. Recently, hemokinin‐1 (HK‐1) was identified as a new member of this family. Although HK‐1 acts on NK1 tachykinin receptors that are thought to be innate for SP, the roles of HK‐1 in neuropathic pain are still unknown.

Experimental approach:

Using rats that had been subjected to chronic constrictive injury (CCI) of the sciatic nerve as a neuropathic pain model, we examined the changes in expression of SP‐ and HK‐1‐encoding genes (TAC1 and TAC4, respectively) in the L4/L5 spinal cord and L4/L5 dorsal root ganglia (DRGs) in association with changes in pain‐related behaviours in this neuropathic pain state.

Key results:

The TAC4 mRNA level was increased on the ipsilateral side of the dorsal spinal cord, but not in DRGs, at day 3 after CCI. In contrast, the TAC1 mRNA level was significantly increased in the DRGs at day 3 after CCI without any changes in the dorsal spinal cord. Analysis of a cultured microglial cell line revealed the presence of TAC4 mRNA in microglial cells. Minocycline, an inhibitor of microglial activation, blocked the increased expression of TAC4 mRNA after CCI and inhibited the associated pain‐related behaviours and microglial activation in the spinal cord.

Conclusions and implications:

The present results suggest that HK‐1 expression is increased at least partly in activated microglial cells after nerve injury and is clearly involved in the early phase of neuropathic pain.

British Journal of Pharmacology (2008) 155, 767–774; doi:10.1038/bjp.2008.301; published online 28 July 2008
Identification of regions of the P2X7receptor that contribute to human and rat species differences in antagonist effects
Authors: Michel A D , Clay W C , Ng S W , Roman S , Thompson K , Condreay J P , Hall M , Holbrook J , Livermore D , Senger S
Published: July 2008

Background and purpose:

Several P2X7receptor antagonists are allosteric inhibitors and exhibit species difference in potency. Furthermore,N2‐(3,4‐difluorophenyl)‐N1‐(2‐methyl‐5‐(1‐piperazinylmethyl)phenyl)glycinamide dihydrochloride (GW791343) exhibits negative allosteric effects at the human P2X7receptor but is a positive allosteric modulator of the rat P2X7receptor. In this study we have identified several regions of the P2X7receptor that contribute to the species differences in antagonist effects.

Experimental approach:

Chimeric human‐rat P2X7receptors were constructed with regions of the rat receptor being inserted into the human receptor. Antagonist effects at these receptors were measured in ethidium accumulation and radioligand binding studies.

Key results:

Exchanging regions of the P2X7receptor close to transmembrane domain 1 modified the effects of KN62, 4‐(4‐fluorophenyl)‐2‐(4‐methylsulphinylphenyl)‐5‐(4‐pyridyl)1H‐imidazole (SB203580) and GW791343. Further studies, in which single amino acids were exchanged, identified amino acid 95 as being primarily responsible for the differential allosteric effects of GW791343 and, to varying degrees, the species differences in potency of SB203580 and KN62. The species selectivity of pyridoxalphosphate‐6‐azophenyl‐2′,4′‐disulphonic acid was affected by multiple regions of the receptor, with potency being particularly affected by the amino acid 126 but not by amino acid 95. A further region of the rat receptor (amino acids 154–183) was identified that, when inserted into the corresponding position in the human receptor, increased ATP potency 10‐fold.

Conclusions:

This study has identified several key residues responsible for the species differences in antagonist effects at the P2X7receptor and also identified a further region of the P2X7receptor that can significantly affect agonist potency at the P2X7receptor.

British Journal of Pharmacology(2008)155, 738–751; doi:10.1038/bjp.2008.306; published online 28 July 2008
The insecticide fipronil and its metabolite fipronil sulphone inhibit the rat α1β2γ2L GABAAreceptor
Authors: Li P , Akk G
Published: July 2008

Background and purpose:

Fipronil is the active ingredient in a number of widely used insecticides. Human exposure to fipronil leads to symptoms (headache, nausea and seizures) typically associated with the antagonism of GABAAreceptors in the brain. In this study, we have examined the modulation of the common brain GABAAreceptor subtype by fipronil and its major metabolite, fipronil sulphone.

Experimental approach:

Whole‐cell and single‐channel recordings were made from HEK 293 cells transiently expressing rat α1β2γ2L GABAAreceptors.

Key results:

The major effect of fipronil was to increase the rate of current decay in macroscopic recordings. In single‐channel recordings, the presence of fipronil resulted in shorter cluster durations without affecting the intracluster open and closed time distributions or the single‐channel conductance. The α1V256S mutation, previously shown alleviate channel inhibition by inhibitory steroids and several insecticides, had a relatively small effect on channel block by fipronil. The mode of action of fipronil sulphone was similar to that of its parent compound but the metabolite was less potent at inhibiting the α1β2γ2L receptor.

Conclusions and implications:

We conclude that exposure to fipronil induces accumulation of receptors in a novel, long‐lived blocked state. This process proceeds in parallel with and independently of, channel desensitization. The lower potency of fipronil sulphone indicates that the conversion serves as a detoxifying process in mammalian brain.

British Journal of Pharmacology(2008)155, 783–794; doi:10.1038/bjp.2008.309; published online 28 July 2008
Atp6v1c1 is an essential component of the osteoclast proton pump and in F-actin ring formation in osteoclasts
Authors: Feng Shengmei , Deng Lianfu , Chen Wei , Shao Jianzhong , Xu Guoliang , Li Yi-Ping
Published: July 2008

Bone resorption relies on the extracellular acidification function of V-ATPase (vacuolar-type proton-translocating ATPase) proton pump(s) present in the plasma membrane of osteoclasts. The exact configuration of the osteoclast-specific ruffled border V-ATPases remains largely unknown. In the present study, we found that the V-ATPase subunit Atp6v1c1 (C1) is highly expressed in osteoclasts, whereas subunits Atp6v1c2a (C2a) and Atp6v1c2b (C2b) are not. The expression level of C1 is highly induced by RANKL [receptor activator for NF-κB (nuclear factor κB) ligand] during osteoclast differentiation; C1 interacts with Atp6v0a3 (a3) and is mainly localized on the ruffled border of activated osteoclasts. The results of the present study show for the first time that C1-silencing by lentivirus-mediated RNA interference severely impaired osteoclast acidification activity and bone resorption, whereas cell differentiation did not appear to be affected, which is similar to a3 silencing. The F-actin (filamentous actin) ring formation was severely defected in C1-depleted osteoclasts but not in a3-depleted and a3−/− osteoclasts. C1 co-localized with microtubules in the plasma membrane and its vicinity in mature osteoclasts. In addition, C1 co-localized with F-actin in the cytoplasm; however, the co-localization chiefly shifted to the cell periphery of mature osteoclasts. The present study demonstrates that Atp6v1c1 is an essential component of the osteoclast proton pump at the osteoclast ruffled border and that it may regulate F-actin ring formation in osteoclast activation.
Temporary Pacemakers
Authors: Trankina Mark F.
Published: July 2008

Temporary cardiac pacing may provide definitive, and even life-saving, therapy for transient bradyarrhythmias or as a bridge to permanent pacemaker placement. Other dysrhythmias may also be amenable to therapy with temporary pacemakers. Serious dysrhythmias may develop perioperatively because of a patient's underly ing disease state, drug administration, and/or intraop erative events. The aging nature of the surgical popula tion and the increasing complexity of surgical patients' medical problems will no doubt contribute to a greater likelihood of encountering perioperative rhythm distur bances. It is therefore essential that anesthesiologists be knowledgeable regarding the indications and contra indications for temporary pacing in the perioperative period. This article describes the numerous potential indications for temporary pacing. Anesthesiologists simi larly need to be familiar with the array of temporary pacing techniques currently available. The techniques reviewed include transvenous pacing, pacing pulmo nary artery catheters, transcutaneous pacing, esopha geal pacing, and transthoracic pacing. By combining a working understanding of the use of these techniques with the technical skills necessary to implement these temporary pacing modalities, the anesthesiologist should be able to successfully establish temporary cardiac pacing.
Anesthesia for Insertion of Implantable Cardioverter Defibdilators
Authors: Cartwright Christopher R. , Hill Laureen L.
Published: July 2008

The use of implantable cardioverter defibrillators (ICDs) for patients at risk for sudden death from ventricular tachycardia or ventricular fibrillation has steadily in creased since the 1980s. ICDs have undergone a signifi cant evolution over the past 2 decades, initially requir ing thoracotomy for placement of epicardial patches to the modern-day devices that involve only transvenously placed leads. Indications for the placement of ICDs are expanding. This article reviews the perioperative anes thetic management of patients undergoing insertion of ICDs. Preoperative assessment of patients for ICD place ment includes careful assessment of underlying medical disease as well as specific determination of the need for continuation or discontinuation of perioperative antiar rhythmic agents. It is important to consider the poten tial effects of anesthetic choice both on hemodynamic stability in patients with limited cardiac reserve and on the ability to intraoperatively induce, and subsequently treat, ventricular dysrhythmias. The relative merits of inhalational and intravenous general anesthesia, as well as those of local anesthesia and intravenous seda tion, should therefore be considered. The present re view also addresses issues of myocardial stunning from repeated defibrillation, cerebral function in the context of repeated circulatory arrest, appropriate intraopera tive monitoring, and postoperative care of patients undergoing ICD placement.
Intraoperative Echocardiography in Pediatric Heart Disease
Authors: Mahajan Aman
Published: July 2008

Intraoperative echocardiography has become an invaluable diagnostic and monitoring technique in surgery for pediatric heart disease. Transesophageal echocardiography (TEE) has largely replaced epicardial echocardiography as the pre ferred approach. TEE has the advantage of allowing serial assessment of anatomy and function with no interruption of surgery. Recent advances in transducer technology of the TEE probe and the introduction of novel modes of imaging have greatly increased the applicability of TEE in pediatric congenital cardiac repair. TEE has been used for a spectrum of congenital lesions such as valve anomalies, shunts, ob structions, and complex heart defects, as well as to monitor for myocardial ischemia and left ventricular preload. Expe rience and evidence suggest that intraoperative TEE can improve clinical outcomes in children undergoing repair of congenital cardiac defects. The safety and efficacy of TEE in children have been well established. This article outlines the development of intraoperative echocardiography and dis cusses TEE as a diagnostic tool in the management of pedi atric heart disease.
Aortic Coarctation: Anesthetic Considerations
Authors: Landsman Ira S. , Davis Peter J.
Published: July 2008

Aortic coarctation is a congenital narrowing of the descend ing thoracic aorta at or near the connection of the ductus arteriosus. It is the sixth most common congenital heart disease in the pediatric age group and constitutes 8% of congenital heart anomalies. Delivering anesthesia care to children undergoing coarctation repair is challenging be cause the anesthetist and the surgeon do not have the immediate safety net provided by cardiopulmonary bypass. Once the aorta is cross-clamped and the repair begins, the anesthesiologist is at the mercy of the surgeon's technical skill and speed and the child's ability to tolerate aortic cross- clamping. This article addresses the etiology and morphol ogy of this lesion. In addition, the perioperative anesthetic management principles relating to coarctation repair are discussed.
Modified Ultrafiltration in Children
Authors: Verghese Susan T.
Published: July 2008

Pediatric cardiopulmonary bypass (CPB) results in increased total body water and capillary permeability. Ultrafiltration has been effective in removing this excess water. The con ventional method of ultrafiltration is restricted by the vol ume in the venous reservoir and therefore is inefficient in smaller children and neonates, whose blood volume is dis proportionately smaller than the circuit volume. Modified ultrafiltration, performed in the immediate post-CPB period, is more effective in these patients. Blood from the aorta is pumped through the ultrafilter, and warm concentrated blood is returned to the right atrium. This removes excess water from the patient and provides a method of salvaging volume from the circuit. Modified ultrafiltration results in consistent improvements in systolic blood pressure, cardiac index, and lung compliance, as well as a reduction in pul monary vascular resistance. Removal of various inflamma tory mediators, such as tumor necrosis factor a, interleu kin-6, and interieukin-8, has been reported after modified ultrafiltration. Other advantages include an increase in he matocrit, colloid osmotic pressure, and coagulation factors, resulting in decreased bleeding and a decreased need for transfusions. In the animal model, improvement in cerebral recovery after deep hypothermic circulatory arrest has been reported. The disadvantages of this technique include the risk of air entrapment, delay in heparin reversal, and poten tial for cooling.
Mechanical Cardiopulmonary Support of Infants and Children With Congenital Heart Disease
Authors: Schure Annette Y. , Laussen Peter C. , McGowan Francis X.
Published: July 2008

Cardiac indications for the use of mechanical cardiopulmo nary support techniques in infants and children include short-term circulatory support during reversible myocardial failure, cardiopulmonary support before and after cardiac surgery, and a bridge to cardiac transplantation. For practi cal purposes, 3 modalities are currently available for these patients: extracorporeal membrane oxygenation, use of ven tricular assist devices, and intra-aortic balloon pump coun terpulsation. Although a variety of devices are available for larger patients, the need for smaller sizes and a wider range of sizes has delayed their use in children. This article sum marizes the current systems available for children as well as indications and outcome data related to their use in infants and children with congenital or acquired heart disease. Copyright © 2001 by W.B. Saunders Company.
The Inflammatory Response to Cardiopulmonary Bypass— Should It Be Treated?
Authors: Hill Gary E.
Published: July 2008

Proinflammatory cytokines, including tumor necrosis factor (TNF) α and the interieukins, are important in the metabolic response to injury or infection. Although the importance of cytokine release during cardiopulmonary bypass (CPB) is not fully appreciated, increasing num bers of publications present evidence that cytokine release during CPB is detrimental. In addition, endoge nous inhibitors of cytokine function, including TNF-sol uble receptor and interleukin 1 receptor antagonist, are released in response to elevated proinflammatory cyto kine levels during and after CPB. The involvement of these endogenous inhibitors in the pathophysiology of proinflammatory cytokine-induced solid organ injury after CPB remains to be defined.
Monitoring Perioperative Ischemia
Authors: Williams Elliott F.
Published: July 2008

This report addresses monitoring for ischemia during surgery and whether perioperative ischemia leads to increased morbidity and mortality in patients with cor onary artery disease (CAD) who are undergoing sur gery. Based on previous studies, it is generally accepted that perioperative ischemia is common in patients with CAD undergoing noncardiac surgery. The incidence of ischemia during the operative period varies greatly with cardiac risk factors, type of surgery, duration of surgery, and the monitor used to detect ischemia. Be cause perioperative cardiac morbidity is the leading cause of death after anesthesia and surgery, it is pru dent for the anesthesia clinician to have an understand ing of the tools available for monitoring as well as their clinical utility. These tools are summarized, and recom mendations are made regarding their use.
Use of Cardiopulmonary Bypass in High-Risk Patients Is a Predictor of Adverse Outcome
Authors: Boyd W. Douglas , Desai Nimesh D. , Novick Richard J. , McKenzie F. Neil , DelRizzo Dario F. , Menkis Alan H.
Published: July 2008

High-risk patients experience substantially more compli cations after coronary artery bypass grafting (CABG). We hypothesized that these patients are uniquely vulner able to cardiopulmonary bypass and compared postop erative outcomes between high-risk patients undergo ing off-pump CAB (OPCAB) and conventional CABG. Prospective provincial cardiac care registry and retro spective chart data were reviewed for 1,850 consecutive patients at our institution between January 1996 and January 1999. From this, 235 patients, 36 OPCAB and 199 CABG, were identified as high risk (modified Parson net score ≥15). Risk factor analysis showed the popula tions were equivalent in perioperative risk with mean modified Parsonnet scores of 18.1 ± 3.4 (OPCAB) and 18.7 ± 4.2 (CABG) (P = .4). In total, 6% of OPCAB and 40% of CABG patients suffered major complications leading to extended hospital/intensive care unit (ICU) stay or death ( P ≤ .001). Mean hospital stays were 7.0 ± 4.0 days (OPCAB) and 10.6 ± 10.2 days (CABG) ( P ≤ .001). Mean ICU stays were 23.9 ± 9.7 hours (OPCAB) and 64.9 ± 128.3 hours (CABG) ( P ≤ .001). Mortality was 0% in the OPCAB group and 6% in the CABG group (P = .2). Multivariate predictors of experiencing a major complication were: use of cardiopulmonary bypass (OR 5.1, 95 Cl 2.1-12.1), age > 80 (OR 2.5, 95 Cl 1.7-7.5), female (OR 3.0, 95 Cl 1.6-5.4), repeat operation (OR 2.5, 95 Cl 1.2-5.4), and ejection fraction <40% (OR 2.4, 95 Cl 1.2-4.7). Extracorporeal circulation is the most impor tant predictor of postoperative complications after CABG in high-risk patients. Off-pump surgery substantially reduces morbidity in this group, and further study of the protective effects of this emerging modality are war ranted.
Preconditioning the Brain and Heart: Implications for Cardiac Surgery
Authors: Johnston William E.
Published: July 2008

Despite many recent advances in emboli detection, aortic imaging, myocardial preservation, and perfusion equipment, ischemic injury to the heart and brain remains a serious complications after cardiac surgery. Hypoperfusion (particularly in the heart) and microem boli (particularly in the brain) during cardiopulmonary bypass constitute the etiology of ischemia. Although hypothermia has traditionally been the mainstay for systemic protection from transient ischemia, there has been a general trend to accept warmer heart and core temperatures during bypass, which increases the poten tial for ischemic injury to various organs. This article discusses recent advances in the understanding of myocardial and brain preconditioning and their poten tial role to provide additional protection during cardiac surgery.
Factors of Stakeholder Understanding of Tourism: The Case of Eastern North Carolina
Authors: Byrd Erick T. , Cárdenas David A. , Greenwood Jerusha B.
Published: July 2008

The purpose of this paper is to provide a tool to better understand a community's knowledge of sustainable tourism principles. An assessment tool was developed to help identify factors of a community's knowledge of sustainable tourism. Exploratory factor analysis was performed to determine the latent structure of the set of variables. Five factors of a stakeholder's understanding of sustainable tourism development were identified in this study. These factors were (1) natural resources, (2) planning, (3) economic concerns, (4) educational needs, and (5) awareness of tourism.
The role of creep in the time-dependent resistance of Ohmic gold contacts in radio frequency microelectromechanical system devices
Authors: Rezvanian O. , Brown C. , Zikry M. A. , Kingon A. I. , Krim J. , Irving D. L. , Brenner D. W.
Published: July 2008

It is shown that measured and calculated time-dependent electrical resistances of closed gold Ohmic switches in radio frequency microelectromechanical system (rf-MEMS) devices are well described by a power law that can be derived from a single asperity creep model. The analysis reveals that the exponent and prefactor in the power law arise, respectively, from the coefficient relating creep rate to applied stress and the initial surface roughness. The analysis also shows that resistance plateaus are not, in fact, limiting resistances but rather result from the small coefficient in the power law. The model predicts that it will take a longer time for the contact resistance to attain a power law relation with each successive closing of the switch due to asperity blunting. Analysis of the first few seconds of the measured resistance for three successive openings and closings of one of the MEMS devices supports this prediction. This work thus provides guidance toward the rational design of Ohmic contacts with enhanced reliabilities by better defining variables that can be controlled through material selection, interface processing, and switch operation.
Phase transformation accommodated plasticity in nanocrystalline nickel
Authors: Zhang X. Y. , Wu X. L. , Liu Q. , Zuo R. L. , Zhu A. W. , Jiang P. , Wei Q. M.
Published: July 2008

Based on detailed x-ray diffraction and transmission electron microscopy we have found body-centered-cubic (bcc) Ni upon room-temperature rolling of nanocrystalline (nc) face-centered-cubic (fcc) Ni. The bcc phase forms via the Kurdjumov–Sachs (KS) martensitic transformation mechanism when the von Mises equivalent strain exceeds ∼0.3, much higher than accessible in tensile testing. The fcc and bcc phases keep either the KS or the Nishiyama–Wasserman orientation relationship. Our results provide insights into the deformation physics in nc Ni, namely, the fcc-to-bcc phase transformation can also accommodate plasticity at large plastic strains.
Effect of Ag interlayer on the optical and passivation properties of flexible and transparent Al2O3∕Ag∕Al2O3 multilayer
Authors: Jeong Jin-A. , Kim Han-Ki , Yi Min-Su
Published: July 2008

We report on the characteristics of a flexible Al2O3∕Ag∕Al2O3 multilayer passivation grown on a polyethylene terephthalate (PET) substrate as a function of Ag thickness. Due to the surface plasmon resonance (SPR) effects and the ductility of the Ag layer that is sandwiched between the dielectric Al2O3 layer, the flexible Al2O3∕Ag∕Al2O3 multilayer passivation exhibits a high transparency of 86.44% and improved flexibility at a Ag thickness of 10nm. We found that SPR effects in the Ag layer occur at the transition region from distinct islands to a continuous film at a critical thickness (∼10nm). In addition, the water vapor transmission rate of the Al2O3∕Ag∕Al2O3∕PET sample decreased as the thickness of the Ag layer increased. Using synchrotron x-ray scattering and field emission scanning electron microscopy, we suggest a possible mechanism to explain the SPR in the Ag layer of the flexible and transparent Al2O3∕Ag∕Al2O3 multilayer passivation.
Quantifying the relation between the morphology and performance of polymer solar cells using Monte Carlo simulations
Authors: Lei Bao , Yao Yan , Kumar Ankit , Yang Yang , Ozolins Vidvuds
Published: July 2008

Morphology is a crucially important factor determining the efficiency of photocurrent generation in bulk heterojunction polymer solar cells. Morphology, which depends on the characteristics of the polymers as well as on the conditions of phase separation, affects the performance of solar cells by influencing the rate of exciton dissociation and the efficiency of charge carrier transport. Using Monte Carlo simulations, we investigate the effects of annealing time on the morphology of phase separation and charge transfer behavior inside the active layers of polymer solar cells. We find that a suitably defined correlation distance is an effective parameter that quantitatively characterizes different morphologies and can be used to establish a direct link with transmission electron microscopy images of real polymer solar cells. Optimal morphologies have been investigated, showing results that are consistent with experimental data.
Room temperature ferromagnetism of Sn1−xCoxO2−δ films fabricated by sol-gel method
Authors: Zuo Yalu , Ge Shihui , Zhao YuXuan , Zhou Xueyun , Xiao Yuhua , Zhang Li
Published: July 2008

Co-doped SnO2 thin films were fabricated by sol-gel method. All the samples have pure rutile polycrystalline structure and exhibit room temperature ferromagnetism (RTFM). Sn1−xCoxO2−δ films spin coated on Si (111) substrate have larger magnetic moment than those on Si (amorphous) substrate. X-ray photoelectron spectra reveal that cobalt exists as Co2+ in samples and Co57 spin-echo nuclear magnetic resonance experiment did not find Co clusters. Interestingly, the magnetic moment per Co atom decreases with the increase in Co content. The results of the annealing at oxidizing and vacuum atmospheres show that oxygen vacancies play a crucial role in producing ferromagnetism, implying that the origin of RTFM can be understood by a bound magnetic polaron model.
Polycrystalline Si nanoparticles and their strong aging enhancement of blue photoluminescence
Authors: Yang Shikuan , Cai Weiping , Zeng Haibo , Li Zhigang
Published: July 2008

Nearly spherical polycrystalline Si nanoparticles with 20 nm diameter were fabricated based on laser ablation of silicon wafer immersed in sodium dodecyl sulfate aqueous solution. Such Si nanoparticles consist of disordered areas and ultrafine grains of 3 nm in mean size and exhibit significant photoluminescence in blue region. Importantly, aging at ambient air leads to continuing enhancement of the emission (more than 130 times higher in 16 weeks) showing stable and strong blue emission. This aging enhancement is attributed to progressive passivation of nonradiative Pb centers corresponding to silicon dangling bonds on the particles’ surface. This study could be helpful in pushing Si into optoelectronic field and Si-based full color display, biomedical tagging, and flash memories.
Structure and optoelectronic properties of spray deposited Mg doped p-CuCrO2 semiconductor oxide thin films
Authors: Rastogi A. C. , Lim S. H. , Desu S. B.
Published: July 2008

Transparent p-type Mg doped CuCrO2 wide-band-gap oxide semiconductor thin films were deposited over quartz substrates by chemical spray technique using metallo-organic precursors. Crystalline single phase CuCrO2 delafossite structure was dominant in ≥700 °C argon ambient annealed films but the as-deposited films contained spinel CuCr2O4 mixed phases. X-ray photoelectron Cr 2p spectra show spin-orbit splitting energy ∼9.8 eV consistent with Cr3+ valance state and Cr 2p3/2 resolved peaks show mixed valence state on Cr4+/Cr6+ confirming CuCr0.93Mg0.07O2 compound phase in spray deposited films. The effect of substrate temperature and film thickness on optical, electrical conductivity, and thermoelectric coefficient was investigated. Highly transparent ≥80% CuCr0.93Mg0.07O2 films with direct and indirect optical band gaps of 3.08 and 2.58 eV for 155 nm and 3.14 and 2.79 for 305 nm thin films, respectively, were obtained. Photoluminescence emission bands at 532 and 484 nm interpreted to arise from 3d94s1 and 3d10 Cu+ intraband transitions confirm mixing of Cu 3d, 4s, and 4p with O 2p orbitals necessary for realizing p-type CuCrO2 films. Electrical conductivity of CuCr0.93Mg0.07O2 films ranged 0.6–1 S cm−1 exhibiting activation energies ∼0.11 eV in 300–420 °K and ∼0.23 eV in ≥420 °K regions ascribed to activated conduction and grain boundary trap assisted conduction, respectively. Transparent p-(CuCr1−xMgxO2)/n-(ZnO) heterojunction diodes showing rectifying current-voltage characteristics were fabricated.
Analysis of resonant detection of terahertz radiation in high-electron mobility transistor with a nanostring/carbon nanotube as the mechanically floating gate
Authors: Leiman V. G. , Ryzhii M. , Satou A. , Ryabova N. , Ryzhii V. , Otsuji T. , Shur M. S.
Published: July 2008

We develop a device model for a resonant detector of electromagnetic radiation with a frequency in the terahertz (THz) range modulated by megahertz (MHz) or gigahertz (GHz) signals based on a micromachined high-electron mobility transistor (HEMT) with a metallized nanostring (NS) or metallic carbon nanotube (CNT) as mechanically the floating gate and analyze the detector operation. The device model describes both the NS/CNT mechanical motion and plasma effects in the HEMT two-dimensional electron channel. Using this model, we calculate the output gate alternating current and the detector responsivity as functions of the carrier (in the THz range) and modulation frequencies, which are in the THz and MHz (or GHz range), respectively. It is shown that the THz detector responsivity exhibits sharp and high maxima under the conditions of both mechanical and plasma resonances.
Multifolded polymer solar cells on flexible substrates
Authors: Zhou Yinhua , Zhang Fengling , Tvingstedt Kristofer , Tian Wenjing , Inganäs Olle
Published: July 2008

Arrays of reflective multijunction polymer solar cell were demonstrated by folding four separated cells fabricated on a single plastic substrate using conducting polymer poly(3, 4-ethylene-dioxythiophene):polystyrenesulfonate as an anode. The combination of flexible substrate and polymer solar cells (PSCs) makes the construction of multifolded PSCs on one substrate possible. The power conversion efficiency (PCE) of the multifolded reflective PSCs was enhanced by 62%±12% with the folded opening angle of 30° compared to the planar cells. In series connection of four solar cells, an open-circuit voltage (Voc) of 3.65V was obtained.
Nanocrystallization and magnetic properties of amorphous Nd9Fe85B6 subjected to high-pressure torsion deformation upon annealing
Authors: Li Wei , Li Lanlan , Nan Yun , Xu Zhenyu , Zhang Xiangyi , Popov A. G. , Gunderov D. V. , Stolyarov V. V.
Published: July 2008

A high number density (∼1023 m−3) of α-Fe nanocrystals with a size below 10 nm has been induced in amorphous Nd9Fe85B6 by high-pressure torsion deformation (HPTD) at room temperature. The amorphous Nd9Fe85B6 subjected to HPTD presents a quite different crystallization behavior as compared with the nondeformed alloy. The growth activation energies Eg=0.9 eV for α-Fe nanocrystals and 0.5 eV for Nd2Fe14B nanocrystals are determined from the annealing time dependence of their size. The α-Fe/Nd2Fe14B nanocomposite magnets prepared by the combination of HPTD and subsequent thermal annealing show enhanced magnetic properties due to a small grain size as compared with the magnets prepared by directly annealing amorphous Nd9Fe85B6.
Direct inkjet printing of silver electrodes on organic semiconductors for thin-film transistors with top contact geometry
Authors: Noguchi Yoshiaki , Sekitani Tsuyoshi , Yokota Tomoyuki , Someya Takao
Published: July 2008

We have fabricated high-performance organic thin-film transistors with top contact geometry using silver source and drain electrodes that are directly patterned on pentacene film by inkjet printing. Ink droplets containing Ag nanoparticles were ejected from inkjet nozzles. By controlling wave forms applied to piezoelectric actuators in these nozzles, the volume of the droplets can be changed from 17 to 1.4 pl. When the volume of the droplets is reduced, dc characteristics of manufactured transistors are improved significantly. The transistors manufactured with droplets of 1.4 pl exhibit a mobility of 0.3 cm2/Vs and an on-off current ratio that exceeding 106.
Voltage from mechanical stress in type-II superconductors: Depinning of the magnetic flux by moving dislocations
Authors: Albert Jaroslav , Chudnovsky E. M.
Published: July 2008

Mechanical stress causes motion of defects in solids. We show that in a type-II superconductor, a moving dislocation generates a pattern of current that exerts a depinning force on the surrounding vortex lattice. The concentration of dislocations and the mechanical stress needed to produce critical depinning currents are shown to be within practical range. When external magnetic field and transport current are present, this effect generates voltage across the superconductor. Thus a superconductor can serve as an electrical sensor of the mechanical stress.
Probing thickness-dependent dislocation storage in freestanding Cu films using residual electrical resistivity
Authors: Chauhan Shakti , Bastawros Ashraf F.
Published: July 2008

Residual electrical resistivity measurement is employed to study dislocation storage under tensile loading of freestanding electroplated Cu films (1–5μm grain size and 2–50μm thickness). The results indicate that the nature of thickness effects (strengthening or weakening) depends on the underlying deformation mechanisms via the average grain size. A threshold grain size of about dg=5μm is identified to distinguish grain size effects in thicker films from those in thinner films. For dg>5μm, diminishing microstructural constraint with reduced thickness weakens the films due to dislocation annihilation near the free surface. For dg<5μm, reduction of film thickness leads to strengthening via grain boundary-source starvation.
Hildahood: Taking the Interpersonal Theory of Nursing to the Neighborhood
Authors: Beeber Linda S.
Published: July 2008

This article examines the use of problematic patterns of interpersonal interactions as an intervention focus that is based on the interpersonal theory of nursing developed by Hildegard Peplau. In previous articles, interpersonal change strategies have been suggested that focus on the patterns that emerge between the client and the nurse. This article proposes an elaboration of the technique by shifting the focus from the "virtual" interactions that occur in the laboratory of the therapeutic nurseclient relationship to the "real" relations between the clients and their significant others. Measurement of the effect of the intervention by the appearance, intensity, and persistence of changes in outcomes along the lines predicted by the theory are illustrated.
Lives of Two Korean Mothers of Children With Schizophrenia:. An Interpretive Approach
Authors: Jung Min
Published: July 2008

BACKGROUND: Although many persons with schizophrenia live at home and rely on family members for support, few studies have looked at the experience from the perspective of the family member as a caregiver.

OBJECTIVE: The goal of this study was to understand the experiences of Korean mothers who are taking care of children with schizophrenia.

DESIGN: The study method was Heideggerian hermeneutic phenomenology. This method enabled the researcher to seek out, from two Korean mothers' stories, their meanings of life in the framework of their sociocultural context.

RESULTS: The mothers' caring experiences played an important part in their life. Their caring experiences led to despair or to the creation of a new way of life, depending on bow free the mothers were from the ideology of "super mother"; how they perceived their past before their child became il and whether they thought of caring as a burden or as a new challenge in their lives.

CONCLUSIONS: This study showed the importance of the interpretive approach in gaining a full understanding of caregivers' lives. It also highlights the needs for nurses to carefully assess and intervene when working with families of mentally il persons, especially when the culture of the client is unfamiliar.
The Shock Doctrine: A Discussion
Authors: Klein Naomi , Smith Neil
Published: July 2008

In this discussion of her book The Shock Doctrine (2007, Metropolitan Books), Naomi Klein outlines a number of its key themes and brings the argument to bear on the California wildfires and developments in Latin America. Key issues discussed include the relation between disaster capitalism and creative destruction, natural disasters, neoliberalism, the antiglobalisation movement, the ‘9/11 truth’ campaign, and the relation of this book to her earlier No Logo (2000, Knopf Canada). Questions come from Neil Smith and from the audience at the Graduate Center, CUNY.
Expertise, Representation and the Common Good: Grounds for Legitimacy in the Urban Governance Network
Authors: Häikiö Liisa
Published: July 2008

This paper discusses the local planning of sustainable development in terms of urban governance. It is particularly interested to examine the grounds for the legitimacy of different actors and the process of legitimation in one urban network. Legitimation is understood here as a discursive process of acceptance in which the actors involved locate themselves and others in the structures of governance. The results indicate that people from the local community and local government justify their positions in the urban governance network and policy-making by means of traditional forms of authorisation—namely, in terms of expertise, representation or the common good. These characteristics have traditionally given legitimacy to the activities and decisions taken by public administration and government. In the case at hand, the traditional grounds for legitimacy are transformed into network-based practices, but those grounds are not pre-given for any of the parties involved. The future challenge in urban governance is to enable the formation of new kinds of political identities that are suitable for governance networks by reforming local discursive practices.
Isomer-Specific Bioactivation and Toxicity of Dichlorophenyl Methylsulphone in Rat Olfactory Mucosa
Authors: Franzén Anna , Carlsson Carina , Brandt Ingvar , Brittebo Eva B.
Published: July 2008

This study aimed to explain the isomer- and site-specific toxic effects of dichlorophenyl methylsulphone in the olfactory mucosa of rats. A single ip dose of the 2,6-chlorinated isomer (16 or 65 mg/kg) induced necrosis preferentially in the Bowman's glands and neuroepithelium in the dorsomedial part of the olfactory region. Only minor damage occurred at this site in rats dosed with the 2,5-chlorinated isomer (65 mg/kg). A strong concentration-and time-dependent covalent binding of the 14C-labeled 2,6-isomer to rat olfactory microsomes was demonstrated. In contrast, no significant covalent binding of the 14C-labeled 2,5-isomer was observed. The cytochrome P450 (CYP) inhibitors metyrapone, tranylcypromine and acetonitrile inhibited covalent binding of the 2,6-isomer to olfactory microsomes. Glutathione (GSH) appeared to play a protective role as a scavenger of a reactive intermediate whereas methyl-GSH did not alter covalent binding to olfactory microsomes. As determined by microautoradiography, binding of the 2,6-chlorinated isomer in the olfactory mucosa was confined to the Bowman's glands. Both isomers showed a low binding to liver microsomes and caused no liver injury. We suggest that a CYP2A-catalyzed activation of the 2,6-chlorinated dichlorophenyl methylsulphone to a reactive intermediate and adduct formation in the Bowman's glands will initiate a site-specific toxicity of this isomer in the olfactory mucosa.
p27 Kip1 (Cdkn1b)-Deficient Mice Are Susceptible to Chemical Carcinogenesis and May Be a Useful Model for Carcinogen Screening
Authors: Payne Shannon R. , Kemp Christopher J.
Published: July 2008

The two-year rodent bioassay is one of several tests that are widely used by governmental regulatory agencies as well as pharmaceutical and chemical companies to determine the carcinogenic potential of chemicals or environmental agents where human exposure is anticipated. That this assay has remained relatively unchanged for the last 25 years is a testament to the power of this approach to identify carcinogens and thus to minimize human exposure. However, there has long been controversy over the specificity and relevance of the rodent bioassay as well as its high cost in terms of time, expense, and numbers of mice. Much discussion has been generated in recent years over how to improve the 2-year rodent bioassay for more accurate and faster detection of potential human carcinogens. Here, we argue that the use of p27Kip1 ( Cdkn1b) knockout mouse for carcinogen screening may solve several shortcomings inherent in the conventional bioassay while preserving its best quality, that is, protecting public health by providing reliable in vivo information on the potential of chemicals to cause cancer.
Pathogenesis of Male Reproductive Tract Lesions from Gestation Through Adulthood Following in Utero Exposure to Di(n-butyl) Phthalate
Authors: Barlow Norman J. , Foster Paul M.D.
Published: July 2008

Di( n-butyl) phthalate (DBP) acts as an antiandrogen by decreasing fetal testicular testosterone synthesis when male rats are exposed in utero. DBPexposed male rats develop malformations of the reproductive tract secondary to the reduced fetal androgen levels. However, these malformations and the associated histologic lesions have only been described in adult rats. The objective of this study was to describe the male reproductive tract lesions in fetal, early postnatal, and young adult male rats following DBP exposure in utero. Pregnant Sprague-Dawley rats were exposed to 500 mg/kg/day DBP by gavage on gestation days (GD) 12 to 21. Male reproductive tracts were examined on GD 16 to 21 and on postnatal days (PND) 3, 7, 16, 21, 45, and 70. In the fetal testes, large aggregates of Leydig cells, multinucleated gonocytes, and increased numbers of gonocytes were first detected on GD 17 and increased in incidence to 100% by GD 20 and 21. These lesions resolved during the early postnatal period, while decreased numbers of spermatocytes were noted on PND 16 and 21. On PND 45, there was mild degeneration of the seminiferous epithelium, which progressed to severe seminiferous epithelial degeneration on PND 70. On PND 70, the degeneration was concurrent with ipsilateral malformed epididymides, which caused obstruction of testicular fluid flow and secondary pressure atrophy in the seminiferous tubules. In the fetus, the epididymal lesion was observed as decreased coiling of the epididymal duct. The decreased coiling progressed into the early postnatal period and adulthood, at which time malformed epididymides were apparent. As the animals were only dosed in utero, these findings indicate that DBP can initiate fetal testicular and epididymal changes that may not manifest as clear malformations until adulthood. The pathogenesis of lesion development from the fetus to the adult is important for comparison of antiandrogens with differing modes of action.
A Spontaneous Mutation: Amelogenesis Imperfecta with Cysts in Rats
Authors: Katsuta Osamu , Hoshino Nobuhito , Takeda Midori , Ono Akihiro , Tsuchitani Minoru
Published: July 2008

Amelogenesis imperfecta (AI) is an inherited dental disease of enamel formation in humans, and there are various phenotypes due to the combination of enamel quality and quantity. We encountered four female IGS rats with spontaneous AI including odontogenic cysts in the incisor teeth. Histopathologically, in the incisors of the rats, the enamel organ was disorganized with the remaining enamel matrix residing within the enamel space. The expanding cysts derived from the enamel organ were formed in the periosteal connective tissue on the labial side. At the bottom of the tooth germs, the precursor cells of the epithelial root sheath were arranged regularly and the enamel organs were preserved to the same degree as those of normal rats. In the molar teeth of the affected rats an enamel matrix remained on the neck and crown of the erupted teeth; however, no abnormality was observed at the tooth root. Although an animal model of AI has been developed from mutants of the SHR-SP rat strain, the present cases represent another potential model of the disease because of the differences in the way the enamel matured and the odontogenic cyst formation in the incisors.
Histiocytic Sarcoma in C57BL/6J Female Mice is Associated with Liver Hematopoiesis: Review of 41 Cases
Authors: Lacroix-Triki Magali , Lacoste-Collin Laetitia , Jozan Suzanne , Charlet Jean-Paul , Caratero Claude , Courtade Monique
Published: July 2008

Forty-one cases of histiocytic sarcoma (HS) in C57BL/6J mice were histopathologically studied with special regard to unexpected associated hematopoietic disorders. These cases were retrieved among C57BL/6J female mice used as control mice in a chronic low-dose irradiation experiment. Hematopoietic characteristics were analysed by comparison to 41 disease-free mice from the same cohort. Tumoral involvement of the liver was observed in all 41 HS-bearing mice, followed by infiltration of the spleen (61.8%), lung (32.4%), bone marrow (14.3%), uterus (12.2%), lymph node (9.8%), and kidney (2.4%). By comparative analysis, we were able to demonstrate a significant association of HS with liver hematopoiesis (89.5% in HS group vs 15% in control mice, p < 0 .00001), and with central hematopoietic disorders involving the myelocytic cells (decreased in HS, p = 0 .003) and erythrocytic cells (increased in HS, p = 0 .001). Microscopic characteristics of these 41 cases and physiopathology of the newly described hematopoietic features in HS are further discussed.
Toxicogenomics in Drug Development
Authors: Guerreiro Nelson , Staedtler Frank , Grenet Olivier , Kehren Jeanne , Chibout Salah-Dine
Published: July 2008

Toxicogenomics represents the merging of toxicology with technologies that have been developed, together with bioinformatics, to identify and quantify global gene expression changes. It represents a new paradigm in drug development and risk assessment, which promises to generate a wealth of information towards an increased understanding of the molecular mechanisms that lead to drug toxicity and efficacy, and of DNA polymorphisms responsible for individual susceptibility to toxicity. Gene expression profiling, through the use of DNA microarray and proteomic technologies will aid in establishing links between expression profiles, mode of action and traditional toxic endpoints. Such patterns of gene expression, or `molecular fingerprints' could be used as diagnostic or predictive markers of exposure, that is characteristic of a specific mechanism of induction of that toxic or efficacious effect. It is anticipated that toxicogenomics will be increasingly integrated into all phases of the drug development process particularly in mechanistic and predictive toxicology, and biomarker discovery. This review provides an overview of the expression profiling technologies applied in toxicogenomics, and discusses the promises as well as the future challenges of applying this discipline to the drug development process.