bluuebunny/crossref_metadata_2025 huggingface dataset:
Vagal branches involved in inhibition of bradykinin‐induced synovial plasma extravasation by intrathecal nicotine and noxious stimulation in the rat.
Authors: Miao F J , Jänig W , Levine J D
Published: December 2014

1. Stimulation of cutaneous and spinal visceral nociceptive afferents and intrathecal nicotine reduces bradykinin‐induced plasma extravasation (BK‐induced PE) in the knee joint of the rat. This depression is mediated by the hypothalamo‐pituitary‐adrenal (HPA) axis and is potentiated by subdiaphragmatic vagotomy. It is believed that activity in vagal afferents tonically inhibits ascending impulse transmission in the neuraxis projecting to the hypothalamus. Vagotomy, by removing such inhibition, allows greater depression of BK‐induced PE. In this study we determined whether the vagal afferents which negatively regulate activities of the HPA axis are present in all branches of the abdominal vagus nerves or only in specific branches. 2. We measured the depression of BK‐induced PE elicited by graded stimulation of spinal visceral afferents with intraperitoneal capsaicin and by intrathecal nicotine in vagus‐intact rats and in rats in which specific vagal branches were selectively interrupted. (i) Interruption of the coeliac branches mimicked the effect of total subdiaphragmatic vagotomy in potentiating the depression of BK‐induced PE generated by intrathecal nicotine and by stimulation of spinal visceral afferents. (ii) Interruption of the gastric and hepatic branches of the abdominal vagus nerves together or individually did not affect the depression of BK‐induced PE generated by the two stimuli. 3. These results indicate that afferent activity in coeliac and accessory coeliac vagal branches is involved in the regulation of the nociceptive system‐initiated depression of BK‐induced PE. The afferent fibres in these vagal branches involved probably monitor physiological events in abdominal visceral organs.
Inhibition of the inward‐rectifying Cl‐ channel in rat choroid plexus by a decrease in extracellular pH.
Authors: Kajita H , Brown P D
Published: December 2014

1. The sensitivity of the inward‐rectifying Cl‐ channel in choroid plexus to changes in external pH (pHo) was examined. 2. Cl‐ currents were recorded using whole‐cell patch‐clamp methods. The inward‐rectifying channel was activated by 375 nM of the catalytic subunit of protein kinase A which was added to the electrode solution. 3. Reducing pHo from 7.3 to 6.5 inhibited the inward‐rectifying Cl‐ currents, whereas an increase in current was observed when pHo was elevated to 8.5. The inhibition of the conductance exhibited a sigmoidal relationship with decreasing pH over a range of 8.5 to 5.5. A half‐maximal inhibition of the current was observed at pH 7.3. 4. The inhibition of the whole‐cell current by reducing pHo suggests that it is carried by channels which are distinct from other inward‐rectifier Cl‐ channels, e.g. ClC‐2, phospholemman and the channel in Xenopus oocytes.
Activation of A2‐purinoceptors by adenosine stimulates L‐arginine transport (system y+) and nitric oxide synthesis in human fetal endothelial cells.
Authors: Sobrevia L , Yudilevich D L , Mann G E
Published: December 2014

1. Human umbilical vein endothelial cells were challenged acutely with adenosine and its analogues to examine whether adenosine modulates L‐arginine transport (system y+) and synthesis of nitric oxide (NO) and prostacyclin (PGI2). 2. L‐Arginine transport was stimulated by adenosine (10 microM, 2 min) and the A2‐receptor agonist 2‐p‐(2‐carboxyethyl)phenethylamino‐5'‐N‐ethylcarboxamidoadenosine (CGS‐21680; 100 nM), but not by the A1‐receptor agonist N6‐cyclopentyladenosine (CPA). 3. Activation of L‐arginine transport was inhibited by the A2‐receptor antagonists ZM‐241385 and 3,7‐dimethyl‐1‐propargylxanthine (DMPX), but unaffected by the A1‐receptor antagonists 8‐cyclopentyl‐1,3‐dipropylxanthine and 8‐phenyltheophylline or the adenosine transport inhibitor nitrobenzylthioinosine. 4. Adenosine and CGS‐21680 evoked a rapid membrane hyperpolarization. 5. Adenosine and CGS‐21680 induced increases in intracellular cGMP levels, whereas release of PGI2 was unaffected. NG‐nitro‐L‐arginine methyl ester (an NO synthase inhibitor) and the A2‐receptor antagonists ZM‐241385 and DMPX prevented increases in cGMP accumulation. 6. Our findings provide the first evidence that activation of human fetal endothelial cell A2‐purinoceptors, but not A1‐purinoceptors, leads to a membrane hyperpolarization and stimulation of basal rates of L‐arginine transport and NO biosynthesis.
Imaging the hierarchical Ca2+ signalling system in HeLa cells.
Authors: Bootman M , Niggli E , Berridge M , Lipp P
Published: December 2014

1. Confocal microscopy was used to investigate hormone‐induced subcellular Ca2+ release signals from the endoplasmic reticulum (ER) in a prototype non‐excitable cell line (HeLa cells). 2. Histamine application evoked two types of elementary Ca2+ signals: (i) Ca2+ blips arising from single ER Ca2+ release channels (amplitude, 30 nM; lateral spreading, 1.3 microns); (ii) Ca2+ puffs resulting from the concerted activation of several Ca2+ blips (amplitude, 170 nM; spreading, 4 microns). 3. Ca2+ waves in the HeLa cells arose from a variable number of initiation sites, but for individual cells, the number and subcellular location of the initiation sites were constant. The kinetics and amplitude of global Ca2+ signals were directly proportional to the number of initiation sites recruited. 4. Reduction of the feedback inherent in intracellular Ca2+ release caused saltatoric Ca2+ waves, revealing the two principal steps underlying wave propagation: diffusion and regeneration. Threshold stimulation evoked abortive Ca2+ waves, caused by the limited recruitment of Ca2+ puffs. 5. The hierarchy of Ca2+ signalling events, from fundamental levels (blips) to intermediate levels (puffs) to Ca2+ waves, is a prototype for Ca2+ signal transduction for non‐excitable cells, and is also analogous to the Ca2+ quarks, Ca2+ sparks and Ca2+ waves in cardiac muscle cells.
Multiple calcium channels control neurotransmitter release from rat postganglionic sympathetic nerve terminals.
Authors: Smith A B , Cunnane T C
Published: December 2014

1. Intracellular recording techniques were used to study neurotransmitter release mechanisms in postganglionic sympathetic nerve terminals of the rat isolated anococcygeus muscle. 2. Low concentrations of the N‐type calcium channel blocker omega‐conotoxin GVIA (omega‐CgTX GVIA) irreversibly abolished excitatory junction potentials (EJPs) evoked by trains of < or = five stimuli at 10 Hz. When the frequency of stimulation was increased (10‐50 Hz) trains of stimuli evoked EJPs even in the presence of 1 microM omega‐CgTX GVIA. We have termed this omega‐CgTX GVIA‐resistant release ‘residual release’. EJP amplitude in the presence of omega‐CgTX GVIA depended on both the frequency and number of stimuli in a train. 3. Residual release was inhibited by the P‐type calcium channel blocker omega‐agatoxin IVA (100 nM). However, even in the presence of both toxins, longer trains of stimuli could still evoke neurotransmitter release. 4. Residual release was abolished by omega‐conotoxin MVIIC and by the non‐specific calcium channel antagonist omega‐grammotoxin SIA. Therefore, it would appear that a heterogeneous population of calcium channels is involved in mediating neurotransmitter release from these sympathetic nerve terminals.
Human Na+ channel fast and slow inactivation in paramyotonia congenita mutants expressed in Xenopus laevis oocytes.
Authors: Richmond J E , Featherstone D E , Ruben P C
Published: December 2014

1. Paramyotonia congenita (PC) is a human hereditary disease caused by one or more amino acid substitutions in skeletal muscle sodium channels. Using macropatches, the effect of PC mutations R1448C and T1313M were compared with wild‐type (WT) in Xenopus oocytes coinjected with both alpha‐ and beta‐subunits of human skeletal muscle (SkM1) sodium channels. 2. Slow inactivation in either T1313M or R1448C was not different from WT. Fast inactivation in both PC mutants, however, was significantly altered. 3. Commonly used biophysical protocols (such as I‐V curves, steady‐state inactivation curves, and measurements of inactivation rates) did not uniformly indicate that hyperexcitability should result from T1313M or R1448C. In fact, the only alteration of fast inactivation common to T1313M and R1448C that predicted cellular hyperexcitability was slowed open‐state inactivation, compared with WT. 4. To test whether this alteration was sufficient to cause the phenotypic hyperexcitability, we used a novel voltage command that simulated muscle membrane activity. With this protocol, we found that R1448C and T1313M were similar in that they maintained a significantly higher channel availability during high frequency activity, compared with WT.
Shal‐type channels contribute to the Ca2+‐independent transient outward K+ current in rat ventricle.
Authors: Fiset C , Clark R B , Shimoni Y , Giles W R
Published: December 2014

1. The hypothesis that Kv4.2 and Kv4.3 are two of the essential K+ channel isoforms underlying the Ca2+‐independent transient outward K+ current (It) in rat ventricle has been tested using a combination of electrophysiological measurements and antisense technology in both native myocytes and a stably transfected mammalian cell line, mouse Ltk‐ cells (L‐cells). 2. The transient outward currents generated by Kv4.2 channels in L‐cells exhibit rapid activation and inactivation properties similar to those produced by It in rat ventricular cells. The current‐voltage relationships and the voltage dependence of steady‐state inactivation are also very similar in these two preparations. However, the recovery from inactivation of Kv4.2 is much slower (time constant, 378 ms) than that of It in rat ventricular cells (58 ms). 3. The K+ current due to Kv4.2 can be blocked by millimolar concentrations of 4‐aminopyridine in L‐cells; a similar pharmacological response has been observed in rat ventricular myocytes. 4. Quinidine inhibits Kv4.2 in L‐cells and It in rat ventricular cells in a similar fashion. In L‐cells quinidine reduced the amplitude of Kv4.2 and accelerated its time course of inactivation, suggesting that quinidine may act as an open channel blocker of Kv4.2, as has been described for It in rat ventricle. 5. To provide further independent evidence that Kv4.2 and Kv4.3 channel isoforms contribute to It in rat ventricular cells, the effects of 20‐mer antisense phosphorothioate oligodeoxynucleotides directed against Kv4.2 and Kv4.3 mRNAs were examined in ventricular myocytes isolated from 14‐ and 20‐day‐old rats, and in L‐cells. In both preparations, Kv4.2 antisense pretreatment significantly reduced the transient outward K+ current (by approximately 55‐60%). Similar reduction of It was produced by the Kv4.3 antisense oligonucleotide on the 14‐day‐old rat myocytes. 6. In 14‐day rat ventricular cells, combination of Kv4.2 and Kv4.3 antisense oligonucleotides did not produce a significantly larger reduction of It than that observed after pretreatment with either antisense oligonucleotide alone. 7. L‐cells stably transfected with Kv4.2 were treated with Kv4.3 antisense oligonucleotide to evaluate the possibility of cross‐reactivity between Kv4.3 antisense and Kv4.2 mRNA. This antisense treatment produced no change in It, verifying the lack of cross‐reactivity. 8. These biophysical and pharmacological results together with the antisense data show that Kv4.2 and Kv4.3 are essential components of the Ca2+‐independent transient outward K+ current, It, in rat ventricular myocytes.
The relationship between tension and slowly varying intracellular calcium concentration in intact frog skeletal muscle.
Authors: Morgan D L , Claflin D R , Julian F J
Published: December 2014

1. The relationship between intracellular calcium concentration, [Ca2+]i, and fixed‐end tension was investigated in intact single muscle fibres from frogs. A slow decline of tension was produced by cyclopiazonic acid (CPA), a sarcoplasmic reticulum Ca2+ uptake pump inhibitor. The fluorescent dyes fura‐2 and furaptra (mag‐fura‐2) were used to estimate [Ca2+]i. 2. Neither the steepness nor the position of the curve changed consistently over a wide range of tension decay times from a few seconds to over 100 s. For these near‐steady‐state curves, the 10‐90% tension change occurred, on average, in 0.07 pCa units, corresponding to a Hill coefficient > 25, much steeper than previously reported. Possible artifacts could reduce that to 15. 3. Methoxyverapamil (D600) reduces the calcium released in response to an action potential. Contractions with D600 and CPA had a slow rise composed of many small steps, and a slow fall. Comparing rise and fall showed little or no hysteresis in the tension‐[Ca2+]i relationship. 4. A model involving co‐operativity between the binding of Ca2+ and myosin to thin filaments is shown to produce a tension‐pCa relationship that is substantially altered by the mean rate constant for detachment of myosin cross‐bridges, which in turn is likely to be affected by sarcomere movements. 5. Such a model is shown to be capable of reproducing the small rise in [Ca2+]i previously reported during the late phase of fixed‐end relaxation of intact fibres.
K+ accumulation and K+ conductance inactivation during action potential trains in giant axons of the squid Sepioteuthis.
Authors: Inoue I , Tsutsui I , Brown E R
Published: December 2014

1. During action potential trains in giant axons from the squid Sepioteuthis, decline of the peak level of the undershoot potential was observed. The time course of the decline of the undershoot could be fitted with a three‐exponential function with time constants of approximately 25, approximately 400 and approximately 7,000 ms, respectively. 2. When the osmolarity of the external solution was doubled by adding glucose (1.2 M), the fast component of undershoot decline, but not the medium and slow components, was significantly reduced. 3. Under voltage clamp in high osmolarity solutions where K+ accumulation was completely removed, repeated depolarizing pulses at 40 Hz (designed to mimic a train of action potentials) elicited K+ currents whose peak value declined. The decline is consistent with inactivation of the K+ conductance (gK). The decline of gK was fitted by a two‐exponential function with time constants of approximately 400 and approximately 7,000 ms, respectively. 4. Interventions designed to modify Schwann cell physiology, such as high frequency stimulation (100 Hz, 2 min), externally applied ouabain (100‐500 microM), L‐glutamate (100 microM), ACh (100 microM), Co2+ (5mM), Ba2+ (2mM), or removal of external Ca2+ by EGTA, had no significant effects on the fast, medium or slow components of undershoot decline. 5. The results suggest that the fast component of undershoot decline represents K+ accumulation in the space between Schwann cell and axolemma. The medium and slow components are the result of axonal gK inactivation. Schwann cells appear to be involved in K+ clearance only to the extent that they provide an efficient physical pathway for the clearance of K+ by extracellular diffusion.
Hypoxia inhibits the recombinant alpha 1C subunit of the human cardiac L‐type Ca2+ channel.
Authors: Fearon I M , Palmer A C , Balmforth A J , Ball S G , Mikala G , Schwartz A , Peers C
Published: December 2014

1. Whole‐cell patch clamp recordings were used to investigate the effects of hypoxia on recombinant human L‐type Ca2+ channel alpha 1C subunits stably expressed in human embryonic kidney (HEK 293) cells. 2. Ca2+ channel currents were reversibly inhibited by hypoxia (PO2 < 90 mmHg). The degree of inhibition depended on the charge carrier used, Ca2+ currents being more O2 sensitive than Ba2+ currents. 3. Hypoxic inhibition of Ca2+ channel currents was more pronounced at lower activating membrane potentials (< or = +30 mV), and was associated with a slowing of activation kinetics. Current inactivation and deactivation were unaffected by hypoxia. 4. Since hypoxia similarly regulates native L‐type Ca2+ channels in vascular smooth muscle cells, our results suggest that hypoxic regulation of L‐type Ca2+ channels arises from modification of structural features of the alpha 1 subunit common to cardiac and smooth muscle L‐type channels.
Ionic mechanism of the effects of hydrogen peroxide in rat ventricular myocytes.
Authors: Ward C A , Giles W R
Published: December 2014

1. Whole‐cell and amphotericin‐perforated patch‐clamp techniques have been used to study the effects of hydrogen peroxide (H2O2) on action potentials and underlying ionic currents in single myocytes from the ventricles of adult rat hearts. 2. The results obtained differed markedly depending on the recording method utilized. Conventional whole‐cell recordings, in which the myoplasm is dialysed with the contents of the pipette, failed to show any significant effects of H2O2 on the action potential or cell shortening. In contrast, when action potentials were recorded with the amphotericin‐perforated patch method, H2O2 (50‐200 microM) produced a marked prolongation of the action potential and an increase in cell shortening. 3. Voltage‐clamp recordings with the amphotericin‐perforated patch method showed that H2O2 caused no significant changes in either the Ca(2+)‐independent transient outward K+ current (Ito) or the inwardly rectifying K+ current (IK1). 4. Application of tetrodotoxin (TTX; 8 x 10(‐6) M), a Na+ channel blocker, largely inhibited the effects of H2O2 on the action potential. Moreover, anthopleurin A (4 x 10 (‐7) M), which augments Na+ current (INa) by slowing its inactivation, mimicked the effects of H2O2 on the action potential of ventricular myocytes. These effects on INa were also blocked almost completely by TTX. 5. The hypothesis that H2O2 can augment INa by slowing its kinetics of inactivation was tested directly using ensemble recordings from cell‐attached macropatches. These results demonstrated a significant enhancement of late opening events when H2O2 (200 microM) was included in the recording pipette. A corresponding slowing of inactivation of the ensemble INa was observed. 6. The possibility that protein kinase C (PKC) is an intracellular second messenger for the observed effects of H2O2 was examined using the blocker bisindolylmaelimide (BIS; 10(‐7) M). Bath application of BIS prior to H2O2 exposure significantly delayed and also attenuated the development of the action potential prolongation. 7. These results demonstrate marked electrophysiological effects of H2O2 in rat ventricle. The dependence of these effects on recording methods suggests involvement of an intracellular second messenger, and the results with the PKC inhibitor, BIS, support this possibility. The most prominent effect of H2O2 on the ionic currents which underlie the action potential is a slowing of inactivation of the TTX‐sensitive INa. Recent molecular studies have demonstrated a PKC phosphorylation site on the rat cardiac Na+ channel isoform and have also shown that PKC activation can slow inactivation of INa.
Run‐down of the GABAA response under experimental ischaemia in acutely dissociated CA1 pyramidal neurones of the rat.
Authors: Harata N , Wu J , Ishibashi H , Ono K , Akaike N
Published: December 2014

1. The effect of experimental ischaemia on the response to gamma‐aminobutyric acid (GABA) was assessed in acutely dissociated CA1 pyramidal neurones of rats, using the patch‐clamp technique. 2. Rapid application of 3 x 10(‐5) M GABA induced a bicuculline‐sensitive inward Cl‐ current (IGABA) at a holding potential (Vh) of ‐44 mV. The peak amplitude of IGABA showed a time‐dependent decrease (run‐down) when it was recorded with the conventional whole‐cell mode without internal ATP. The run‐down was not observed when the intracellular ATP concentration ([ATP]i) was maintained by the nystatin‐perforated recording with an intracellular Na+ concentration ([Na+]i) of 0 mM. 3. When [Na+]i was increased to more than 30 mM, the IGABA run‐down was observed even with the nystatin‐perforated recording. 4. The IGABA run‐down observed at 60 mM [Na+]i with the nystatin method was further enhanced under experimental ischaemia without changes in the reversal potential of IGABA. The enhanced run‐down was suppressed by application of the Na+,K(+)‐ATPase inhibitors, ouabain and SPAI‐1. 5. IGABA run‐down during ischaemia was also accompanied by an outward holding current and a concomitant increase in intracellular free Ca2+ concentration ([Ca2+]i) in 48.5% of the neurones. The outward current was a Ca(2+)‐activated K+ current, which was blocked by 3 x 10(‐7) M charybdotoxin. 6. In the inside‐out mode of the single‐channel analysis, GABA activated three subconductance states with conductances of 33.4, 22.7 and 15.2 pS. Reduction of ATP concentration from 2 to 0 mM on the intracellular side suppressed the channel activities, while an increase in Ca2+ concentration from 0.7 x 10(‐9) to 1.1 x 10(‐6) M had no effect. 7. These results suggest that ischaemia induces the run‐down of the postsynaptic GABA response at the GABAA receptor level, and that this run‐down is triggered by a decrease in [ATP]i.
Noncontact Measurement Method of Vibration Stress Using Optical Displacement Sensors for Piping Systems in Nuclear Power Plants
Authors: Maekawa Akira , Takahashi Tsuneo , Tsuji Takashi , Noda Michiyasu
Published: December 2014

In nuclear power plants, vibration stress of piping is frequently measured to prevent the occurrence of fatigue failure. A simpler and more efficient measurement method is desired for rapid integrity evaluation of piping. In this study, a method to measure vibration stress in a noncontact manner using optical displacement sensors is presented and validated. The proposed method estimates vibration-induced stress of small-bore piping directly using noncontact sensors based on a light-emission diode. First, the noncontact measurement method was proposed, and the measurement instrument based on the proposed method was developed for the validation. Next, vibration measurement experiments using the instrument were conducted for a mock-up piping system and an actual piping system. The measurement results were compared with the values measured by the conventional method of known accuracy using strain gauges. From this comparison, the proposed noncontact measurement method was demonstrated to be able to provide sufficient accuracy for practical use.
Refined Navier-Stokes-Fourier Equations for Rarefied Polyatomic Gases
Authors: Rahimi Behnam , Struchtrup Henning
Published: December 2014

A macroscopic model for the description of rarefied polyatomic gas flows is introduced. Grad’s moment method is used to construct a closed set of equations for 36 primary moments. The order of magnitude method is then applied to acquire optimized moment definitions. The appropriate sets of equations corresponding to the desired order of accuracy in the Knudsen number are derived by reducing the equations. A refined version of the Navier-Stokes-Fourier (NSF) equations is obtained where the dynamic temperature is an additional independent variable.
Multiscale Simulation of Knudsen-Pump Channel Flows
Authors: Patronis Alexander , Lockerby Duncan A.
Published: December 2014

This paper describes the development and application of an efficient hybrid continuum-molecular approach for simulating non-isothermal, low-speed, internal rarefied gas flows, and its application to flows in Knudsen compressors. The method is an extension of the hybrid approach presented by Patronis et al. (2013) [J. Comp. Phys., 255, pp 558–571], which is based on the framework originally proposed by Borg et al. (2013) [J. Comp. Phys., 233, pp 400–413] for the simulation of micro/nano flows of high-aspect-ratio.

The efficiency of the multiscale method allows the investigation of alternative Knudsen-compressor configurations to be undertaken. We characterise the effectiveness of the single-stage Knudsen-compressor channel by the pressure differential that can be achieved between two connected reservoirs, for a given temperature difference. Our multiscale simulations indicate that the efficiency of the single-stage Knudsen compressor is robust to modifications of the streamwise temperature variation.
An Analysis of Two-Phase Flow Pressure Drop in Operating Proton Exchange Membrane Fuel Cell Channels With the Lockhart-Martinelli Approach
Authors: Anderson Ryan , Zhang Lifeng , Wilkinson David P.
Published: December 2014

Proton exchange membrane fuel cells (PEMFCs) are considered one of the most promising alternatives for the automotive industry owing to their high energy efficiency, zero emission at the vehicle use stage, and low temperature operation. Water as a byproduct plays a complex role in fuel cell operation. In particular, the inevitable occurrence of liquid water leads to gas-liquid two-phase flows in various components of PEMFCs including flow channels of which diameters range from micrometers to millimeters. In conventional minichannels and microchannels, the Lockhart-Martinelli (LM) approach has been employed to predict the two-phase pressure drop of gas-liquid systems. This approach has previously been updated by our group to more accurately reflect the introduction of liquid water into the flow channels of a PEMFC i.e. from a porous media perpendicular to the gas flow. Importantly, the LM method normalizes the data independent of the flow field design and operating conditions like temperature, pressure, and relative humidity. This paper analyzes the increasing amount of experimental data on two-phase flow pressure drops/two-phase flow multipliers in the literature with these approaches. The focus is the cathode side (therefore an air/water system), and data is collected from multiple research groups using active fuel cells (electrochemically produced water). The traditional LM approach greatly under-predicts the two-phase pressure drop at low current densities. However, the analysis is applied over a range of current densities, and it better predicts results at higher current densities (>600 mA cm−2). Literature correlations for the Chisholm parameter C, a flow regime dependent parameter in the LM equation, have been proposed for non-active (external water injection) fuel cells but do not match the results from operating fuel cells. C is shown here to vary with current density, flow stoichiometry (gas velocity), gas diffusion layer, and slightly with relative humidity.
Experimental Characterization of an Open Loop Pulsating Heat Pipe Cooler
Authors: Torresin Daniele , Habert Mathieu , Agostini Francesco , Agostini Bruno , Mounier Violette
Published: December 2014

Pulsating heat pipes (PHP) have emerged in the last years as suitable cooling devices for dissipating the high heat loads generated by electronic devices since they allow to extend the applicability of air cooling in area nowadays covered by water cooling. Two-phase cooling technologies based on the two phase pulsating heat pipe principle are promising solutions because, being entirely passive they can comply with long term operation without maintenance. The main advantage of a PHP compared to conventional thermosyphon technologies for electronics cooling is that a PHP is orientation independent. The authors has developed a novel, compact, and low cost PHP based on automotive technology. The present paper presents the experimental results of an air cooled open loop pulsating heat pipe with optimized manifold design to minimize fluid pressure drops in the fluid turns. The effect of several parameters including filling ratio and heat load are presented. Tests have been done with the refrigerant fluid R245fa in vertical and horizontal orientations. The measurements showed a maximum thermal resistance ranging between 40 and 48 K/kW in vertical and horizontal position respectively for a heat load of 2 kW and air temperature of 20 °C.
Improved film quality of plasma enhanced atomic layer deposition SiO2 using plasma treatment cycle
Authors: Kim Haiwon , Chung Ilsub , Kim Seokyun , Shin Seungwoo , Jung Wooduck , Hwang Ryong , Jeong Choonsik , Hwang Hanna
Published: December 2014

Chemical, physical, and electrical characteristics of high quality silicon dioxide (SiO2) films grown using low temperature plasma enhanced atomic layer deposition (PE-ALD) have been investigated as a buffer layer for three dimensional vertical nand flash memory devices. The comparative angle resolved x-ray photoelectron spectroscopy studies show the plasma treatment cycle causes to shift the core level binding energy (chemical shifts) in the SiO2 film. The wet etch rates with respect to plasma treatment cycle times were varied due to curing of the SiO2 network defects by Ar+ ions and oxygen radicals. It is assumed that the angle between the bonds linking SiO4 tetrahedra is a critical point understanding the variation in wet etch rate of SiO2. The features of wet etch rate of low temperature high quality SiO2 demonstrated lower than high temperature low-pressure chemical vapor deposition (LP-CVD) SiO2 values. In addition, the better step-coverage compared to that of the LP-CVD SiO2 film was achieved from the deep trench structure having the 20:1 aspect ratio. PE-ALD SiO2 with plasma treatment cycle showed excellent I–V properties with higher breakdown voltage compared to LP-CVD SiO2 and similar to the thermal SiO2 carrier transport plot.
A new quantitative image analysis method for improving breast cancer diagnosis using DCE‐MRI examinations
Authors: Yang Qian , Li Lihua , Zhang Juan , Shao Guoliang , Zheng Bin
Published: December 2014

Purpose:

To investigate the feasibility of applying a new quantitative image analysis method to improve breast cancer diagnosis performance using dynamic contrast enhanced magnetic resonance imaging (DCE‐MRI) by integrating background parenchymal enhancement (BPE) features into the decision making process.

Methods:

A dataset involving 115 DCE‐MRI examinations was used in this study. Each examination depicts one identified suspicious breast tumor. Among them, 75 cases were verified as malignant and 40 were benign by the biopsy results. A computer‐aided detection scheme was applied to segment breast regions and the suspicious tumor depicted on the sequentially scanned MR images of each case. We then computed 18 kinetic features in which 6 were computed from the segmented breast tumor and 12 were BPE features from the background parenchymal regions (excluding the tumor). Support vector machine (SVM) based statistical learning classifiers were trained and optimized using different combinations of features that were computed either from tumor only or from both tumor and BPE. Each SVM was tested using a leave‐one‐case‐out validation method and assessed using an area under the receiver operating characteristic curve (AUC).

Results:

When using kinetic features computed from tumors only, the maximum AUC is 0.865 ± 0.035. After fusing with the BPE features, AUC increased to 0.919 ± 0.029. At 90% specificity, the tumor classification sensitivity increased by 13.2%.

Conclusions:

The proposed quantitative BPE features provide valuable supplementary information to the kinetic features of breast tumors in DCE‐MRI. Their addition to computer‐aided diagnosis methodologies could improve breast cancer diagnosis based on DCE‐MRI examinations.
Leptin Receptor Mutation Results in Defective Neutrophil Recruitment to the Colon during Entamoeba histolytica Infection
Authors: Naylor Caitlin , Burgess Stacey , Madan Rajat , Buonomo Erica , Razzaq Khadija , Ralston Katherine , Petri William A.
Published: December 2014

Amebiasis is an enteric infection caused byEntamoeba histolytica, with symptoms ranging in severity from asymptomatic colonization to dysentery. Humans with the Q223R leptin receptor mutation have increased susceptibility to amebiasis, but the mechanism has been unclear. Using a mouse model expressing the mutation, we tested the impact of the Q223R mutation on the innate immune response toE. histolyticainfection. The 223R mutation resulted in delayed clearance of amebae from the cecum, as had been previously observed. We found that neutrophil influx to the site of the infection was reduced 12 h after infection in 223R mice. Depletion of neutrophils with anti-Ly6G monoclonal antibody increased susceptibility of wild-type mice to infection, supporting the importance of neutrophils in innate defense. Leptin expression was increased in the cecum byE. histolyticainfection, suggesting that leptin could serve as a homing signal for neutrophils to the gut. Interestingly, neutrophils from mice with the 223R mutation had diminished chemotaxis toward leptin. This impaired chemotaxis likely explained the reduced gut infiltration of neutrophils. The newly recognized effect of the leptin receptor Q223R mutation on neutrophil chemotaxis and the impact of this mutation on multiple infectious diseases suggest a broader impact of this mutation on susceptibility to disease.

IMPORTANCEThe Q223R leptin receptor mutation results in increased susceptibility of children and adults toE. histolytica, one of the leading causes of diarrhea morbidity and mortality in children of the developing world. Here we show that the mutation results in reduced neutrophil infiltration to the site of infection. This decreased infiltration is likely due to the mutation’s impact on neutrophil chemotaxis toward leptin, an inflammatory agent upregulated in the cecum after infection. The significance of this work thus extends beyond understandingE. histolyticasusceptibility by also providing insight into the potential impact of leptin on neutrophil function in other states of altered leptin signaling, which include both malnutrition and obesity.
Sirtuins Are Evolutionarily Conserved Viral Restriction Factors
Authors: Koyuncu Emre , Budayeva Hanna G. , Miteva Yana V. , Ricci Dante P. , Silhavy Thomas J. , Shenk Thomas , Cristea Ileana M.
Published: December 2014

The seven human sirtuins are a family of ubiquitously expressed and evolutionarily conserved NAD+-dependent deacylases/mono-ADP ribosyltransferases that regulate numerous cellular and organismal functions, including metabolism, cell cycle, and longevity. Here, we report the discovery that all seven sirtuins have broad-range antiviral properties. We demonstrate that small interfering RNA (siRNA)-mediated knockdown of individual sirtuins and drug-mediated inhibition of sirtuin enzymatic activity increase the production of virus progeny in infected human cells. This impact on virus growth is observed for both DNA and RNA viruses. Importantly, sirtuin-activating drugs inhibit the replication of diverse viruses, as we demonstrate for human cytomegalovirus, a slowly replicating DNA virus, and influenza A (H1N1) virus, an RNA virus that multiplies rapidly. Furthermore, sirtuin defense functions are evolutionarily conserved, since CobB, the sirtuin homologue inEscherichia coli, protects against bacteriophages. Altogether, our findings establish sirtuins as broad-spectrum and evolutionarily conserved components of the immune defense system, providing a framework for elucidating a new set of host cell defense mechanisms and developing sirtuin modulators with antiviral activity.

IMPORTANCEWe live in a sea of viruses, some of which are human pathogens. These pathogenic viruses exhibit numerous differences: DNA or RNA genomes, enveloped or naked virions, nuclear or cytoplasmic replication, diverse disease symptoms, etc. Most antiviral drugs target specific viral proteins. Consequently, they often work for only one virus, and their efficacy can be compromised by the rapid evolution of resistant variants. There is a need for the identification of host proteins with broad-spectrum antiviral functions, which provide effective targets for therapeutic treatments that limit the evolution of viral resistance. Here, we report that sirtuins present such an opportunity for the development of broad-spectrum antiviral treatments, since our findings highlight these enzymes as ancient defense factors that protect against a variety of viral pathogens.
Pancreaticoatmospheric fistula following severe acute necrotising pancreatitis
Authors: Simoneau Eve , Chughtai Talat , Razek Tarek , Deckelbaum Dan L
Published: December 2014

Severe acute necrotising pancreatitis is associated with numerous local and systemic complications. Abdominal compartment syndrome requiring urgent decompressive laparotomy is a potential complication of this disease process and is associated with increased morbidity and mortality. We describe the case of a pancreaticoatmospheric fistula following decompressive laparotomy in a patient with severe acute necrotising pancreatitis. While this fistula was managed successfully using the current standard of care for pancreatic fistulas, the wound care for in this patient with drainage of the fistula through an open abdomen, is a significant challenge.
A national survey of the diagnosis and management of suspected ventilator-associated pneumonia
Authors: Browne Emma , Hellyer Thomas P , Baudouin Simon V , Conway Morris Andrew , Linnett Vanessa , McAuley Danny F , Perkins Gavin D , Simpson A John
Published: December 2014

Background

Ventilator-associated pneumonia (VAP) affects up to 20% of patients admitted to intensive care units (ICU). It is associated with increased morbidity, mortality and healthcare costs. Despite published guidelines, variability in diagnosis and management exists, the extent of which remains unclear. We sought to characterise consultant opinions surrounding diagnostic and management practice for VAP in the UK.

Methods

An online survey was sent to all consultant members of the UK Intensive Care Society (n=∼1500). Data were collected regarding respondents’ individual practice in the investigation and management of suspected VAP including use of diagnostic criteria, microbiological sampling, chest X-ray (CXR), bronchoscopy and antibiotic treatments.

Results

339 (23%) responses were received from a broadly representative spectrum of ICU consultants. All respondents indicated that microbiological confirmation should be sought, the majority (57.8%) stating they would take an endotracheal aspirate prior to starting empirical antibiotics. Microbiology reporting services were described as qualitative only by 29.7%. Only 17% of respondents had access to routine reporting of CXRs by a radiologist. Little consensus exists regarding technique for bronchoalveolar lavage (BAL) with the reported volume of saline used ranging from 5 to 500 mL. 24.5% of consultants felt inadequately trained in bronchoscopy.

Conclusions

There is wide variability in the approach to diagnosis and management of VAP among UK consultants. Such variability challenges the reliability of the diagnosis of VAP and its reported incidence as a performance indicator in healthcare systems. The data presented suggest increased radiological and microbiological support, and standardisation of BAL technique, might improve this situation.
An unified approach to inelastic light scattering in Keldysh–Schwinger functional integral formalism
Authors: Lee Hyun Cheol
Published: December 2014

We propose a theoretical framework which can treat the nonresonant and the resonant inelastic light scattering on an equal footing in the form of correlation function, employing Keldysh–Schwinger functional integral formalism. The interference between the nonresonant and the resonant process can be also incorporated in this framework. This approach is applied to the magnetic Raman scattering of two-dimensional antiferromagnetic insulators. The entire set of the scattering cross-sections are obtained at finite temperature, the result for the resonant part agrees with the one obtained by the conventional Fermi golden rule at zero temperature. The interference contribution is shown to be very sensitive to the scattering geometry and the band structure.
Compensatory Smoking from Gradual and Immediate Reduction in Cigarette Nicotine Content
Authors: Hatsukami Dorothy K. , Donny Eric C. , Koopmeiners Joseph S. , Benowitz Neal L.
Published: December 2014

Reducing the addictiveness of cigarettes by reducing their nicotine content can potentially have a profound impact on public health. Two different approaches to nicotine reduction have been proposed: gradual and immediate. To determine if either of these approaches results in significant compensatory smoking behavior, which might lead to safety concerns, we performed a secondary analysis of data from studies that have utilized these two approaches. The number of cigarettes smoked per day, carbon monoxide exposure, and cotinine levels in plasma or urine were assessed while participants smoked reduced nicotine content cigarettes and compared with when they smoked their usual brand cigarettes. The results showed that in general, these two approaches led to minimal compensatory smoking and reduced levels of cotinine over the course of the experimental period, suggesting that neither of these approaches poses a major safety concern. Cancer Epidemiol Biomarkers Prev; 24(2); 472–6. ©2014 AACR.
Tobacco and Alcohol in Relation to Male Breast Cancer: An Analysis of the Male Breast Cancer Pooling Project Consortium
Authors: Cook Michael B. , Guénel Pascal , Gapstur Susan M. , van den Brandt Piet A. , Michels Karin B. , Casagrande John T. , Cooke Rosie , Van Den Eeden Stephen K. , Ewertz Marianne , Falk Roni T. , Gaudet Mia M. , Gkiokas George , Habel Laurel A. , Hsing Ann W. , Johnson Kenneth , Kolonel Laurence N. , La Vecchia Carlo , Lynge Elsebeth , Lubin Jay H. , McCormack Valerie A. , Negri Eva , Olsson Håkan , Parisi Dominick , Petridou Eleni Th. , Riboli Elio , Sesso Howard D. , Swerdlow Anthony , Thomas David B. , Willett Walter C. , Brinton Louise A.
Published: December 2014

Background: The etiology of male breast cancer is poorly understood, partly due to its relative rarity. Although tobacco and alcohol exposures are known carcinogens, their association with male breast cancer risk remains ill-defined.

Methods: The Male Breast Cancer Pooling Project consortium provided 2,378 cases and 51,959 controls for analysis from 10 case–control and 10 cohort studies. Individual participant data were harmonized and pooled. Unconditional logistic regression was used to estimate study design–specific (case–control/cohort) ORs and 95% confidence intervals (CI), which were then combined using fixed-effects meta-analysis.

Results: Cigarette smoking status, smoking pack-years, duration, intensity, and age at initiation were not associated with male breast cancer risk. Relations with cigar and pipe smoking, tobacco chewing, and snuff use were also null. Recent alcohol consumption and average grams of alcohol consumed per day were also not associated with risk; only one subanalysis of very high recent alcohol consumption (>60 g/day) was tentatively associated with male breast cancer (ORunexposed referent = 1.29; 95% CI, 0.97–1.71; OR>0–<7 g/day referent = 1.36; 95% CI, 1.04–1.77). Specific alcoholic beverage types were not associated with male breast cancer. Relations were not altered when stratified by age or body mass index.

Conclusions: In this analysis of the Male Breast Cancer Pooling Project, we found little evidence that tobacco and alcohol exposures were associated with risk of male breast cancer.

Impact: Tobacco and alcohol do not appear to be carcinogenic for male breast cancer. Future studies should aim to assess these exposures in relation to subtypes of male breast cancer. Cancer Epidemiol Biomarkers Prev; 24(3); 520–31. ©2014 AACR.
The Emergence of “Religious Studies” (zongjiaoxue) in Late Imperial and Republican China, 1890–1949
Authors: Meyer Christian
Published: December 2014

This article contextualizes the rise of “early religious studies in China” with its apex in the 1920s within the heated debates on the role of religion in a modern Chinese society. While the most recent development of religious studies (zongjiaoxue) in China (including Mainland China, Hong Kong, and Taiwan) is well known, its early emergence in the late Qing and Republican periods (ca. 1890–1949) has been a neglected topic. The author demonstrates first how antagonistic anti-religious and affirmative positions, received from Western modernization discourse and informed by the contested character of the concept of religion itself, led to the emergence of this new discipline in Republican China as a product of broader discourses on modernization. Secondly, the article evaluates the limited institutionalization of religious studies as a distinct “full” discipline in relation to the broader interdisciplinary “field” of research and public debates on religion. While the interdisciplinary character is typical of the field in general (also in the West), the limited degree of “full disciplinarity” depended on specific, local discursive and political factors of its time. As “religion” appears as an important modern discourse in East Asia, the early emergence of religious studies in China thereby reflects social, political, and intellectual transitions from Imperial to Republican China, and offers a unique perspective on Asian discourses on religious and secular modernities.
Sleepy Scribes and Clever Critics
Authors: Kamphuis Bart L.F. , Krans Jan L.H. , Castelli Silvia , Peerbolte Bert Jan Lietaert
Published: December 2014

This article presents a classification of conjectures on the text of the New Testament. It focusses on the types of arguments used by conjectural critics. The argumentation for a conjecture basically comprises (1) the perception of a problem (or problems) in the transmitted text and (2) the suggestion of a cause (or causes) for the supposed scribal change. Type (or types) of perceived problems and of supposed causes are classified, and illustrated with a range of important conjectures.
Nog Eens: De Utrechtse School en de Eigen Aard van Het Geloof
Authors: G. Geertsema Henk
Published: December 2014

In de vorige jaargang van dit tijdschrift heb ik twee artikelen gepubliceerd over de wijsgerige theologie van de zogenaamde Utrechtse school. Daarop is gereageerd door respectievelijk M. Sarot, G. van den Brink en V. Brümmer. Er zijn drie punten waarop ik de discussie graag kort wil voortzetten: logische consistentie en conceptuele coherentie als norm voor het geloof, het verfijnde realisme, en de eigen aard van de theologie in vergelijking met het concrete geloven. In feite gaat het daarbij steeds om de eigen aard van het geloof. Daarin ligt ook de reden ruimte te vragen voor deze reactie. Het lijkt mij van bijzonder belang voor de (wijsgerige) theologie dat het concrete geloven op de juiste manier wordt verstaan. Alleen dan kan de theologie dit geloof werkelijk dienen. Dat geldt tegenover het gevaar van versubjectivering van het geloof evenzeer als tegenover dat van verintellectualisering.
Prevalence of hepatitis C virus infection among pregnant women in a rural district in Egypt
Authors: Khamis Hossam Hassan , Farghaly Azza Galal , Shatat Hanan Zakaria , El-Ghitany Engy Mohamed
Published: December 2014

Background

Egypt has the highest prevalence of hepatitis C virus (HCV) infection in the world. Screening of HCV during pregnancy is not as routinely done in Egypt compared with many other countries, although pregnancy is an important period where screening of HCV infection is important owing to low immunity, the possibility of vertical transmission and possible horizontal transmission to the baby or other household contacts at a later stage.

Aim

To determine the seroprevalence of HCV antibodies (HCV-Ab) and risk factors associated with infection among pregnant women in Egypt.

Patients and Method

A total of 360 pregnant women visiting the healthcare units for routine antenatal care were tested using third generation ELISA test for detection of HCV-Ab. Polymerase chain reaction (PCR) was done for seropositive cases.

Results

A total of 6.1% (22/360) of pregnant women were HCV seropositive; of them only 45% (9/20) had viraemia. Risk factors were their age, the age of their husband and the presence of chronic liver disease in the husband.

Conclusion

The prevalence of HCV infection in pregnant women in Egypt appears to be lower than previously reported. The detected risk factors are old age of the pregnant women and their husbands, and chronic liver disease in the husbands. None of the other known risk factors was found to be significantly associated with HCV infection in pregnant women.