bluuebunny/crossref_metadata_2025 huggingface dataset:
HAWKING RADIATION AS TUNNELING AND THE UNIFIED FIRST LAW OF THERMODYNAMICS FOR A CLASS OF DYNAMICAL BLACK HOLES
Authors: KE-XIA JIANG , SAN-MIN KE , DAN-TAO PENG
Published: November 2009

An analysis is made for relations between the tunneling rate and the unified first law of thermodynamics at the trapping horizons of two kinds of spherically symmetric dynamical black holes. The first kind is the Vaidya–Bardeen black hole; the tunneling rate Γ ~ e△S can be obtained naturally from the unified first law at the apparent horizon, which holds the form dEH = TdS + WdV. The second kind is the McVittie solution; the action of the radial null geodesic of the outgoing particles does not always have a pole at the apparent horizon, while the ingoing mode always has one. The solution of the ingoing mode of the radiation can be mathematically reduced to the case in the FRW universe smoothly. However, as a black hole, the physical meaning is unclear and even puzzling.
ANALYTIC SOLUTION FOR MATTER DENSITY PERTURBATIONS IN A CLASS OF VIABLE COSMOLOGICAL f(R) MODELS
Authors: MOTOHASHI HAYATO , STAROBINSKY ALEXEI A. , YOKOYAMA JUN'ICHI
Published: November 2009

For a class of viable cosmological models in f(R) gravity in which deviation from the Einstein gravity decreases as an inverse power law of the Ricci scalar R for large R, an analytic solution for density perturbations in the matter component during the matter-dominated stage is obtained in terms of hypergeometric functions. An analytical expression for the matter transfer function at scales much smaller than the present Hubble scale is also obtained.
GEOMETRICAL DIAGNOSTIC FOR THE GENERALIZED CHAPLYGIN GAS MODEL
Authors: LU JIANBO , XU LIXIN
Published: November 2009

A new diagnostic method, Om, is applied to the generalized Chaplygin gas (GCG) model as the unification of dark matter and dark energy. On the basis of the recently observed data — the Union supernovae, the observational Hubble data, the SDSS baryon acoustic peak and the five-year WMAP shift parameter — we show the discriminations between the GCG model and the ΛCDM model. Furthermore, it is calculated that the current equation of state of dark energy w 0de = -0.964, according to the GCG model.
RECONSTRUCTING THE POTENTIALS FOR THE QUINTESSENCE AND TACHYON DARK ENERGY, FROM THE HOLOGRAPHIC PRINCIPLE
Authors: GRANDA L. N.
Published: November 2009

We propose holographic quintessence and tachyon models of dark energy. The correspondence between the quintessence and tachyon energy densities with the holographic density allows the reconstruction of the potentials and the dynamics for the quintessence and tachyon fields, in the flat FRW background. The proposed infrared cutoff for the holographic energy density works for two cases of the constant α: for α < 1 we reconstruct the holographic quintessence model in the region before the ω = -1 crossing for the EoS parameter. The cosmological dynamics for α > 1 is also reconstructed for the holographic quintessence and tachyon models.
Eu3+ DOPED SILICA FILM AS LUMINESCENT DOWN-SHIFTING LAYER FOR CRYSTALLINE Si SOLAR CELLS
Authors: CHENG ZUJUN , PAN LIKUN , SU FENFANG , CAO MEILING , SUN ZHUO
Published: November 2009

Eu3+ doped silica films have been prepared by sol–gel method and employed as luminescent down-shifting layer on the front side of a crystalline Si solar cell to improve their conversion efficiency. Measurements under standard test conditions (AM1.5, 100 mW/cm2) show the conversion efficiency of Si solar cell with silica film containing Eu 3+ is improved 9.5% maximally as compared to the Si solar cell with pure silica film. However, high Eu 3+ concentration is not encouraged because concentration quenching effect will decrease the efficiency of the solar cell.
CONVERSION OF INDUCTION HEATING DEPOSITED MONETITE COATING TO HYDROXYAPATITE COATING ONHT–C/CCOMPOSITES BY HYDROTHERMAL TREATMENT IN KOH AQUEOUS/AMMONIA SOLUTION
Authors: LI DONG-MEI , XIONG XIN-BO , ZENG XIE-RONG , ZOU CHUN-LI , ZOU JI-ZHAO
Published: November 2009

Carbon/carbon composites with hydroxyapatite coatings are one of the attractive materials in the dental and orthopedic fields. In this study, hydrothermal treatment, in KOH aqueous and ammonia solutions, was used to convert an induction-heating-deposited monetite coating to an adherent HA coating on H2O2treated C/C composites. The structure, morphology and chemical composition of the as-received HA coatings were characterized by XRD, FTIR, SEM and EDS. A scratch test was conducted to measure the adhesion of HA coatings to HT – C/C substrate. The results show that well-crystallized carbonate hydroxyapatite coatings could be achieved under the two reaction mediums. However, the as-obtained HA coatings after KOH hydrothermal treatment have higher crystallinity and Ca/P ratio than those after ammonia hydrothermal treatment, and reveal an average critical load of 29 N which is more than two times as high as that for HA coatings after ammonia hydrothermal treatment.
FINITE ELEMENT ANALYSIS OF VALENCE BAND STRUCTURE OF SQUARE QUANTUM WELL UNDER THE ELECTRIC FIELD
Authors: GUNES M. , KASAPOGLU E. , SARI H. , AKGUNGOR K. , SÖKMEN I.
Published: November 2009

Valence band structure with spin–orbit (SO) coupling of GaAs/Ga 1-x Al x As square quantum well (SQW) under the electric field by a calculation procedure based on a finite element method (FEM) is investigated using the multiband effective mass theory ([Formula: see text] method). The validity of the method is confirmed with the results of D. Ahn, S. L. Chuang and Y. C. Chang (J. Appl. Phys.64 (1998) 4056), who calculated valence band structure, using axial approximation for Luttinger–Kohn Hamiltonian and finite difference method. Our results demonstrated that SO coupling and electric field have significant effects on the valence band structure.
DYNAMICS AND TOPOGRAPHY OF QUASI-2D NEEDLE-LIKE SILVER ELECTROCHEMICAL DEPOSITS UNDER A QUASI-STEADY-STATE REGIME
Authors: PASQUALE M. A. , VICENTE J. L. , ARVIA A. J.
Published: November 2009

The electrochemical formation of single silver needles from aqueous silver sulfate was studied under both potentiostatic and galvanostatic conditions utilizing different quasi-2D cells. Under potentiostatic conditions, four (I–IV) stages of growth were distinguished. Stage III involved single needle growth under a quasi-steady-state (q-ss) regime in which, at the millimeter scale, the tip profile remained almost unchanged. Fast growing needles exhibited a truncated quasi-conical tip, and slow growing ones approached prolate hemispheroids. At stage III, the almost constant q-ss silver deposition rate was evaluated from the tip front displacement (dLz/dt) perpendicularly to the tangential plane of the tip. For the cathode to anode potential difference in the range -1.00 ≤ Ec-a≤ -0.22 V , values of (dLz/dt) in the range 0.08–2.0 μm s-1were obtained. At the needle stem, the q-ss radial silver deposition rate (dLx/dt) was about two orders of magnitude lower than (dLz/dt). The transition from stage III to IV was characterized by tip thickening, i.e. a change in the tip q-conical profile to that of a prolate hemispheroid, and eventual tip splitting. Scanning electron micrographs at the micrometer scale of single silver needle tips from potentiostatic runs showed either a defined crystallography or an irregular topography covered by a large number of tiny crystals. In contrast, stems were always faceted. This difference indicated that surface relaxation processes following silver ion mass transport and discharge played a relevant role in the needle growth mode. At stage III, the growth regime is described utilizing a dual diffusion (D) and migration (M) model consisting of a DM direct contribution that becomes dominant at the needle stem, and a space charge (SC)-assisted DM contribution that operates at the tip apex. This explanation is consistent with the local cathodic current density values, the concentration ratio of silver clusters at the stem and tip apex surface, and the distinct kinetic behavior of needles produced from potentiostatic and galvanostatic runs. The complex link between mass transport phenomena of silver ions from the binary solution side, the silver ion discharge at the interface and the surface relaxation of silver adatoms and clusters at the metal lattice shed new light on the aspects of single silver needle formation.
RAMAN, DIELECTRIC AND OPTICAL INVESTIGATIONS OF DLC THIN FILMS
Authors: MALEKFAR RASOUL , MOTAHARI HAMID , ROHOLLAHNEJAD JALAL , SAHRAIYAN FATEMEH
Published: November 2009

Diamond-like carbon, DLC, thin films which is an amorphous hydrogenated form of carbon, a-C:H , has been synthesized by CVD method. SEM imaging, back-scattering Raman spectroscopy and reflected FT-IR spectroscopy have been used for characterization of the synthesized thin films. Kramers–Kronig dispersion relations have been used for the calculation of dielectric and optical parameters, which include the real and imaginary parts of the refractive and dielectric indices. In Raman spectroscopy, two obvious, wide and almost symmetrical peaks around 1355 cm-1 (D mode) and 1520–1550 cm-1 (G mode), clarify the formation of a-C:H thin film. Reflected spectra of thin films, in the spectral region of 400–4000 cm-1, have been recorded by the near normal FTIR reflection spectroscopy and show some peaks which can be assigned to the bending of sp3 C–C , sp3 or sp2 CH . The calculated data show that dielectric and optical parameters are almost independent of wavenumber.
SURFACE MORPHOLOGY, ETCHING AND MECHANICAL STRENGTH OF A SEMIORGANIC NONLINEAR OPTICAL CRYSTAL THIOUREA CADMIUM-ZINC SULPHATE (CZTS)
Authors: MARIAPPAN L. , DEVASHANKAR S. , RATHNAKUMARI M. , SURESHKUMAR P.
Published: November 2009

Thiourea cadmium-zinc sulphate (CZTS), a semi-organic nonlinear optical material has been grown from solution by slow evaporation technique. Solubility of the synthesized material has been determined for various temperatures using water as solvent. Single crystal X-ray diffraction studies confirm that the grown crystal belongs to the triclinic system. The surface morphology and facets of the as-grown crystal were studied by contact goniometry. Functional groups present in the sample were identified by FTIR spectral analysis. Microhardness and etching studies have been carried out on the grown crystals. The SHG relative efficiency of thiourea cadmium-zinc sulphate crystal was found to be 1.8 times higher than that of KDP.
TRIBOLOGICAL PROPERTIES OF SURFACE LAYER WITH BORON IN FRICTION PAIRS
Authors: LUBAS JANUSZ
Published: November 2009

The aim of the present work is to determine the influence of technologically produced boron surface layers on the friction parameters in the sliding pairs under the conditions of mixed friction. The tribological evaluation included ion nitrided, pack borided, laser borided, quenched and tempered surface layers and TiB2 coating deposited on 38CrAlMo5-10 , 46Cr2 and 30MnB4 steels. Modified surface layers of annular samples were matched under test conditions with counter-sample made from AlSn20 bearing alloy. Tested sliding pairs were lubricated with 15 W/40 Lotos mineral engine oil. The tribological tests were conducted on a T-05 block on ring tester. The applied steel surface layer modification with boron allows surface layers to be created with pre-determined tribological characteristics required for the elements of kinematic pairs operating in the conditions of sliding friction. Pack boronizing reduces the friction coefficient during the start-up of the frictional pair and the maximum start-up resistance level is similar to the levels of pairs with nitrided surface layers.
SURFACE TREATMENT OF ANTI-CREASE FINISHED COTTON FABRIC BASED ON SOL–GEL TECHNOLOGY
Authors: WANG CHAOXIA , CHEN LI
Published: November 2009

The silica sol was applied onto 1, 2, 3, 4-butanetetracarboxylic acid (BTCA) finished cotton fabrics with the attempt to improve the physical properties especially the tensile strength which had a big loss in the previous anti-crease finishing processing. The parameters including the dosage of the coupling agent, the concentration and pH of the sol and the processing methods were studied in detail. Compared to the sample finished with BTCA, 11.8% of the increase in the crease recovery angle and 18.6% of the enhancement in the tensile strength of the cotton fabric also treated with silica sol in the better selected conditions were obtained. The abrasion resistance was also improved.
TRANSPORT PROPERTIES OF THERMALLY EVAPORATED In2Se3 THIN FILMS
Authors: NITHYAPRAKASH D. , PUNITHAVENI B. , CHANDRASEKARAN J.
Published: November 2009

Thin films of In2Se3 were prepared by thermal evaporation. X-ray diffraction indicated that the as-grown films were amorphous in nature and became polycrystalline γ-In2Se3 films after annealing. The ac conductivity and dielectric properties of In2Se3 films have been investigated in the frequency range 100 Hz–100 kHz. The ac conductivity σ ac is found to be proportional to ωn where n < 1. The temperature dependence of both ac conductivity and the parameter n is reasonably well interpreted by the correlated barrier hopping (CBH) model. The values of dielectric constant ε and loss tangent tan δ were found to increase with frequency and temperature. The ac conductivity of the films was found to be hopping mechanism. In I–V characteristic for different field and temperature were studied and it has been found that the conduction process is Poole–Frenkel type.
Synergistic antifibrotic efficacy of statin and protein kinase C inhibitor in hepatic fibrosis
Authors: Yang Jong In , Yoon Jung-Hwan , Bang Yung-Jue , Lee Sung-Hee , Lee Soo-Mi , Byun Hee Jin , Myung Sun-Jung , Kim Won , Lee Hyo-Suk
Published: November 2009

Statin has antifibrotic efficacy in human fibrosing diseases, such as pulmonary and renal fibrosis, and is therefore implicated in hepatic fibrosis. However, statin can also activate protein kinase C (PKC), which augments hepatic fibrogenesis and is thereby likely to reduce the antifibrotic efficacy of statin. This study was designed to explore the hypothesis that simultaneous treatment with statin and PKC inhibitor may synergistically enhance antifibrotic efficacy in hepatic fibrosis. Hepatic fibrosis models were established in BALB/c mice by intraperitoneal injection of carbon tetrachloride or thioacetamide for 6 wk. Pravastatin and enzastaurin (PKC inhibitor) were administered by gavage for 5 wk. Cellular apoptosis was explored using 4′,6-diamidino-2-phenylindole or terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end-labeling (TUNEL) staining and immunoblot analysis. Hepatic fibrosis and hepatic stellate cell (HSC) activation were assessed by morphometric analysis of histological findings and immunohistochemistry for α-smooth muscle actin. In vitro, the addition of PKC inhibitor significantly increased statin-induced LX-2 cell apoptosis by enhancing the activation of mitochondrial apoptotic signals. TUNEL-positive HSCs were significantly increased in mice treated with statin + PKC inhibitor compared with those in control or single compound-treated mice. The percentage of area occupied by activated HSCs and the extent of collagen deposition were significantly decreased in mice treated with statin + PKC inhibitor compared with those in control or statin-treated mice. In conclusion, simultaneous treatment with statin and PKC inhibitor synergistically enhanced the antifibrotic efficacy in both in vitro and in vivo models of hepatic fibrosis and may therefore have therapeutic implication for reducing hepatic fibrosis.
Endothelial cell responses to atheroprone flow are driven by two separate flow components: low time-average shear stress and fluid flow reversal
Authors: Conway Daniel E. , Williams Marcie R. , Eskin Suzanne G. , McIntire Larry V.
Published: November 2009

To simulate the effects of shear stress in regions of the vasculature prone to developing atherosclerosis, we subjected human umbilical vein endothelial cells to reversing shear stress to mimic the hemodynamic conditions at the wall of the carotid sinus, a site of complex, reversing blood flow and commonly observed atherosclerosis. We compared the effects of reversing shear stress (time-average: 1 dyn/cm2, maximum: +11 dyn/cm2, minimum: −11 dyn/cm2, 1 Hz), arterial steady shear stress (15 dyn/cm2), and low steady shear stress (1 dyn/cm2) on gene expression, cell proliferation, and monocyte adhesiveness. Microarray analysis revealed that most differentially expressed genes were similarly regulated by all three shear stress regimens compared with static culture. Comparisons of the three shear stress regimens to each other identified 138 genes regulated by low average shear stress and 22 genes regulated by fluid reversal. Low average shear stress induced increased cell proliferation compared with high shear stress. Only reversing shear stress exposure induced monocyte adhesion. The adhesion of monocytes was partially inhibited by the incubation of endothelial cells with ICAM-1 blocking antibody. Increased heparan sulfate proteoglycan expression was observed on the surface of cells exposed to reversing shear stress. Heparinase III treatment significantly reduced monocyte adhesion. Our results suggest that low steady shear stress is the major impetus for differential gene expression and cell proliferation, whereas reversing flow regulates monocyte adhesion.
Involvement of Rho kinase in the pathogenesis of acute pulmonary embolism-induced polystyrene microspheres in rats
Authors: Toba M. , Nagaoka T. , Morio Y. , Sato K. , Uchida K. , Homma N. , Takahashi K.
Published: November 2009

Acute pulmonary embolism (PE) is a life-threatening disease, and several vasoconstrictors, including endothelin-1 (ET-1), play a key role in vasoconstriction and hypoxemia during the development of PE. Rho kinase is activated by various vasoconstrictors resulting in vascular contraction and remodeling. Recent evidence has revealed an important role of Rho kinase in the pathogenesis of systemic and pulmonary vascular diseases. However, contribution of Rho kinase in PE remains unclear. We thus investigated the role of Rho kinase in the PE rat model induced by intrajugular administration of polystyrene microspheres (mean diameter, 26 μm). At 6 h following the administration of microspheres (1.5 ml/kg), right ventricular systolic pressure (RVSP) was higher in the PE than in the control rats (15.8 ± 1.6 vs. 32.9 ± 7.5 mmHg). Arterial oxygen tension was lower (92.3 ± 12.5 vs. 66.0 ± 17.7 Torr), and alveolar-arterial difference in oxygen partial pressure was higher (3.9 ± 3.8 vs. 36.5 ± 26.9 Torr) in the PE rats. Western blotting analysis revealed upregulation and downregulation in expression of vascular cell adhesion molecule-1 and endothelial nitric oxide synthase in lungs from the PE rats, respectively, and radioimmunoassay demonstrated an increase in plasma ET-1 levels. Lung Rho kinase α expression was greater in the PE rats. At 5 h following administration of microspheres (0.75 ml/kg), intravenous Rho kinase inhibitors HA1077 and Y27632 (3 mg/kg each) attenuated elevation of RVSP (22.0 ± 3.7, 17.1 ± 3.2, 14.3 ± 2.6 mmHg, PE, PE+HA1077, PE+Y27632) and the severity of hypoxemia (66.3 ± 16.2, 94.9 ± 23.0, 89.1 ± 8.5 Torr, PE, PE+HA1077, PE+Y27632) in the PE rats. These results suggest that pulmonary endothelial dysfunction and activation of Rho kinase may contribute to the potentiation of vasoconstriction and hypoxemia in the PE rats.
Influence of acetaminophen on performance during time trial cycling
Authors: Mauger Alexis R. , Jones Andrew M. , Williams Craig A.
Published: November 2009

To establish whether acetaminophen improves performance of self-paced exercise through the reduction of perceived pain, 13 trained male cyclists performed a self-paced 10-mile (16.1 km) cycle time trial (TT) following the ingestion of either acetaminophen (ACT) or a placebo (PLA), administered in randomized double-blind design. TT were completed in a significantly faster time ( t12= 2.55, P < 0.05) under the ACT condition (26 min 15 s ± 1 min 36 s vs. 26 min 45 s ± 2 min 2 s). Power output (PO) was higher during the middle section of the TT in the ACT condition, resulting in a higher mean PO ( P < 0.05) (265 ± 12 vs. 255 ± 15 W). Blood lactate concentration (B[La]) and heart rate (HR) were higher in the ACT condition (B[La] = 6.1 ± 2.9 mmol/l; HR = 87 ± 7%max) than in the PLA condition (B[La] = 5.1 ± 2.6 mmol/l; HR = 84 ± 9%max) ( P < 0.05). No significant difference in rating of perceived exertion (ACT = 15.5 ± 0.2; PLA = 15.7 ± 0.2) or perceived pain (ACT = 5.6 ± 0.2; PLA = 5.5 ± 0.2) ( P > 0.05) was observed. Using acetaminophen, participants cycled at a higher mean PO, with an increased HR and B[La], but without changes in perceived pain or exertion. Consequently, completion time was significantly faster. These findings support the notion that exercise is regulated by pain perception, and increased pain tolerance can improve exercise capacity.
Time course of changes in inflammatory markers during a 6-mo exercise intervention in sedentary middle-aged men: a randomized-controlled trial
Authors: Thompson Dylan , Markovitch Daniella , Betts James A. , Mazzatti Dawn , Turner James , Tyrrell Rex M.
Published: November 2009

Regular exercise may improve systemic markers of chronic inflammation, but direct evidence and dose-response information is lacking. The objective of this study was to examine the effect and time course of changes in markers of chronic inflammation in response to progressive exercise training (and subsequent detraining). Forty-one sedentary men 45–64 yr of age completed either a progressive 24-wk exercise intervention or control followed by short-term removal of the intervention (2-wk detraining). Serum IL-6 fell by −0.4 pg/ml (SD 0.6) after 12 wk and responded to moderate-intensity exercise. Serum alanine aminotransferase (ALT) activity fell −7 U/l (SD 11) at 24 wk although there was no evidence of any change by week 12 (and therefore ALT required more vigorous-intensity activity and/or a more prolonged intervention). The effect on IL-6 was lost after 2-wk detraining whereas the change in ALT was retained. The temporal fall and rise in IL-6 with training and subsequent detraining in men with high IL-6 at baseline provided a retrospective opportunity to examine parallel genomic changes in peripheral mononuclear cells. A subset of 53 probes was differentially regulated by at least twofold after training with 31 of these changes being lost after detraining ( n = 6). IL-6 responded quickly to the carefully monitored exercise intervention (within weeks) and required only moderate-intensity exercise, whereas ALT took longer to change and/or required more vigorous-intensity exercise. Further work is required to determine whether any of the genes that temporally changed in parallel with changes in IL-6 are a cause or consequence of this response.
Elevations in ostensibly anabolic hormones with resistance exercise enhance neither training-induced muscle hypertrophy nor strength of the elbow flexors
Authors: West Daniel W. D. , Burd Nicholas A. , Tang Jason E. , Moore Daniel R. , Staples Aaron W. , Holwerda Andrew M. , Baker Steven K. , Phillips Stuart M.
Published: November 2009

The aim of our study was to determine whether resistance exercise-induced elevations in endogenous hormones enhance muscle strength and hypertrophy with training. Twelve healthy young men (21.8 ± 1.2 yr, body mass index = 23.1 ± 0.6 kg/m2) trained their elbow flexors independently for 15 wk on separate days and under different hormonal milieu. In one training condition, participants performed isolated arm curl exercise designed to maintain basal hormone concentrations (low hormone, LH); in the other training condition, participants performed identical arm exercise to the LH condition followed immediately by a high volume of leg resistance exercise to elicit a large increase in endogenous hormones (high hormone, HH). There was no elevation in serum growth hormone (GH), insulin-like growth factor (IGF-1), or testosterone after the LH protocol but significant ( P < 0.001) elevations in these hormones immediately and 15 and 30 min after the HH protocol. The hormone responses elicited by each respective exercise protocol late in the training period were similar to the response elicited early in the training period, indicating that a divergent postexercise hormone response was maintained over the training period. Muscle cross-sectional area (CSA) increased by 12% in LH and 10% in HH ( P < 0.001) with no difference between conditions (condition × training interaction, P = 0.25). Similarly, type I ( P < 0.01) and type II ( P < 0.001) muscle fiber CSA increased with training with no effect of hormone elevation in the HH condition. Strength increased in both arms, but the increase was not different between the LH and HH conditions. We conclude that exposure of loaded muscle to acute exercise-induced elevations in endogenous anabolic hormones enhances neither muscle hypertrophy nor strength with resistance training in young men.
Study on the Different Expression of Molecular Markers between Cardiac Cancer and Distal Gastric Cancer and Their Correlations with Clinicopathological Features
Authors: Ye Yan-wei , Fu Hong , Zhou Ye , Du Chun-yan , Li Bai-zhou , Zhu Lei , Shi Ying-qiang
Published: November 2009

Background and Aim: Currently, few studies have reported the different expression of molecular markers between distal gastric cancer and cardiac cancer. Here, we sought to make an investigation about it by a retrospective analysis. Methods: The expression of 8 proteins, including epidermal growth factor receptor, glutathione S-transferase π (GST-π), cyclin D1, Neu/Her-2, C-myc, p53, p27 and p21, were evaluated in 110 cases with cardiac cancer and 101 cases with distal gastric cancer who underwent curative surgery at the Cancer Hospital, Fudan University, in 2005 by immunohistochemistry method. Results: The TNM stage, differentiation grade, invasion depth and lymph node metastasis were significantly different between cardiac cancer and distal gastric cancer. p21 (p = 0.034), Neu (p = 0.017), and GST-π (p = 0.003) were expressed in relatively higher levels in cardiac cancer than in distal gastric cancer. Furthermore, the clinical pathological parameters were significantly correlated with the expression of molecules mentioned above. Conclusion: Different molecular mechanisms may be involved in the tumorigenesis and development of cardiac cancer and distal gastric cancer.
Roux-en-Y Gastrojejunostomy Using Modified Hemi-Double Stapling
Authors: Kim Dong-Heon , Jeon Tae-Yong , Kim Dae-Hwan , Kim Dong-Il , Sim Mun-Sup , Kim Suk
Published: November 2009

For reconstruction after distal gastrectomy, the Roux-en-Y gastrojejunostomy is superior to the Billroth II gastrojejunostomy in terms of bile reflux. Roux-en-Y gastrojejunostomy prevents reflux gastritis, esophagitis, and carcinogenesis of the gastric remnant. However, the Roux-en-Y gastrojejunostomy is relatively complicated and lengthy. The authors perform a simple, safe Roux-en-Y gastrojejunostomy using modified hemi-double stapling. We applied this technique to 42 patients with gastric cancer. The average operating and reconstruction times were 172.6 ± 42.0 and 26.2 ± 4.8 min, respectively. The postoperative courses were uneventful and the patients were discharged 11.2 ± 2.4 days postoperatively. Neither leakage nor bleeding from the gastrojejunostomy has occurred postoperatively. The postoperative follow-up was 7–24 months and no local recurrence or stricture at the gastrojejunostomy site occurred. Roux-en-Y gastrojejunostomy using the modified hemi-double stapling technique can achieve reconstruction more simply, safely and quickly, and may provide an alternative reconstruction method for distal gastrectomy.
Hospital Volume and Quality of Laparoscopic Gastrectomy in Japan
Authors: Kuwabara Kazuaki , Matsuda Shinya , Fushimi Kiyohide , Ishikawa Koichi B. , Horiguchi Hiromasa , Fujimori Kenji
Published: November 2009

Background: Laparoscopic gastrectomy (LG) has become the prevailing surgery of choice for gastric cancer, but the impact of hospital volume or operating room (OR) time has not been evaluated. An observational study was conducted to assess the quality of LG based on hospital volume and OR time. Methods: 3,054 LG patients were enrolled in 420 hospitals throughout Japan. Analyzed variables included patient demographics, complications, use of stapling devices or chemotherapy, hospital volume, and teaching status. Hospitals were categorized into high- (≥4 LG per month), intermediate- (1–3) and low- (<1) volume hospitals. Multivariate analysis was used to measure hospital volume and OR time impact. Results: 259 laparoscopic total gastrectomies (LTGs) were performed. Complications were observed in 269 cases (8.8%). High-volume hospitals treated less severe cases. OR time, but not hospital volume, was associated with complications. Hospital volume, teaching status and stapling devices explained variations in OR time. Conclusion: OR time was a more significant predictor of complications than hospital volume. OR time was consumed more in the employment of stapling devices and LTG. To promote LG efficiency, training curricula highlighting the applicability of these techniques should be considered by clinical experts.
Principles of Local Drug Delivery to the Inner Ear
Authors: Salt Alec N. , Plontke Stefan K.
Published: November 2009

As more and more substances have been shown in preclinical studies to be capable of preventing damage to the inner ear from exposure to noise, ototoxic drugs, ischemia, infection, inflammation, mechanical trauma and other insults, it is becoming very important to develop feasible and safe methods for the targeted delivery of drugs to specific regions in the inner ear. Recently developed methods for sampling perilymph from the cochlea have overcome major technical problems that have distorted previous pharmacokinetic studies of the ear. These measurements show that drug distribution in perilymph is dominated by passive diffusion, resulting in large gradients along the cochlea when drugs are applied intratympanically. Therefore, in order to direct drugs to specific regions of the ear, a variety of delivery strategies are required. To target drugs to the basal cochlear turn and vestibular system while minimizing exposure of the apical cochlear turns, single one-shot intratympanic applications are effective. To increase the amount of drug reaching the apical cochlear turns, repeated intratympanic injections or controlled-release drug delivery systems, such as biodegradable biopolymers or catheters and pumps, are more effective. However, if the applied substance does not easily pass through the round window membrane, or if a more widespread distribution of drug in the ear is required, then intralabyrinthine injections of the substance may be required. Intralabyrinthine injection procedures, which are currently in development in animals, have not yet been proven safe enough for human use.
Vestibular Function and Vertigo Control after Intratympanic Gentamicin for Ménière’s Disease
Authors: Nguyen Kimanh D. , Minor Lloyd B. , Della Santina Charles C. , Carey John P.
Published: November 2009

The aim of this study was to correlate long-term vertigo control with reduction in vestibular function after intratympanic (IT) gentamicin therapy for unilateral Ménière’s disease. IT gentamicin injections were given as needed to control vertigo attacks. Vertigo frequency and changes in angular vestibulo-ocular reflex (AVOR) gain (measured using magnetic search coils and manual head thrusts) and caloric weakness were assessed before and after treatment. Better vertigo control after treatment was found with ≥60% reduction in quantitative ipsilateral horizontal semicircular canal AVOR gain from pre-treatment values and/or with caloric unilateral weakness (UW) >50%. However, no correlations were found between the continuous variables of vertigo control and either gain or gain recovery, nor between gain and UW because of the large variability in vertigo control in subjects with lesser reductions in these measures.
Intratympanic Steroids for Inner Ear Disorders: A Review
Authors: Hu Amanda , Parnes Lorne S.
Published: November 2009

Background/Aim: The use of intratympanic steroids (ITS) has proliferated over the past 10–15 years to include treatments for inner ear disorders, like Ménière’s Disease (MD) and sudden sensorineural hearing loss (SSNHL). The aim of this study was to review the clinical trials of ITS for inner ear disorders. Methods: PubMed and Ovid Medline databases were searched from 1966 to present for clinical trials on ITS in the treatment of MD and SSNHL. Studies were evaluated based on comparability and internal and external validity. Results: Thirty-eight studies were identified in total, 13 studies on MD and 25 studies on SSNHL. Most studies lacked placebo controls. Only 3 studies were double-blinded randomized prospective trials. Overall, there were heterogeneous steroid doses, treatment protocols, previous treatments, and definitions of disease and improvement. Conclusion: There are no good studies on ITS that meet the criteria of comparability, internal validity, and external validity. It is difficult to compare studies due to the heterogeneous nature of the data. More rigorously designed studies are required to determine the efficacy of this treatment, the optimal steroid to use, and the best treatment regimen.
Dose-Dependent Sustained Release of Dexamethasone in Inner Ear Cochlear Fluids Using a Novel Local Delivery Approach
Authors: Wang Xiaobo , Dellamary Luis , Fernandez Rayne , Harrop Anne , Keithley Elizabeth M. , Harris Jeffrey P. , Ye Qiang , Lichter Jay , LeBel Carl , Piu Fabrice
Published: November 2009

The thermo-reversible triblock copolymer poloxamer 407 was investigated as a drug delivery vehicle for micronized dexamethasone into the middle and inner ears of guinea pigs. The study characterized the gelation and in vitro release kinetics of poloxamer formulations. In vivo, the pharmacokinetic profile of formulations containing varying concentrations of poloxamer and dexamethasone was examined following intratympanic administration. Significant drug levels within the perilymph were observed for at least 10 days, while systemic exposure was minimal. The sustained-release kinetics profile could be significantly modulated by varying the concentrations of both poloxamer and dexamethasone. Assessment of auditory function revealed a small transient shift in hearing threshold, most probably of conductive nature, which resolved itself within a week. No significant histological changes of the round window membrane or cochlea could be noted. Poloxamer 407 thus represents an effective and safe delivery system to achieve sustained release of dexamethasone to the inner ear.
Blocking the Glucocorticoid Receptor with RU-486 Does Not Prevent Glucocorticoid Control of Autoimmune Mouse Hearing Loss
Authors: Trune Dennis R. , Kempton J. Beth
Published: November 2009

Background/Aims: Glucocorticoids effectively manage autoimmune hearing loss, although the cochlear mechanisms involved are unknown. Previous studies of steroid-responsive hearing loss in autoimmune (lupus) mice showed glucocorticoids and mineralocorticoids were equally effective, suggesting the ion homeostasis functions of glucocorticoids may be as relevant as immunosuppression for control of autoimmune-induced inner ear disease. Therefore, to better characterize the role of the glucocorticoid receptor in autoimmune hearing loss therapy, its function was blocked with the antagonist RU-486 (mifepristone) during glucocorticoid (prednisolone) treatments. Methods: Following baseline auditory brainstem response (ABR) thresholds, MRL/MpJ-Faslpr autoimmune mice were implanted with pellets providing combinations of 1.25 mg/kg of RU-486, 4 mg/kg of prednisolone, or their respective placebos. After 1 month, animals were retested with ABR and blood was collected for immune complex analyses. Results: Mice receiving no prednisolone (placebo + placebo and placebo + RU-486) showed continued declines in hearing. On the other hand, mice receiving prednisolone (prednisolone + placebo and prednisolone + RU-486) had significantly better hearing (p < 0.05) than the non-prednisolone groups. Immune complexes were significantly elevated in the placebo + RU-486 group, suggesting RU-486 effectively blocked glucocorticoid receptor-mediated immune suppression. These results showed that blockage of the glucocorticoid receptor with RU-486 did not prevent prednisolone’s effects in the ear, suggesting its ion homeostasis actions via the mineralocorticoid receptor were more relevant in hearing control. Conclusion: The mineralocorticoid receptor-mediated actions of glucocorticoids are potentially relevant in steroid-responsive hearing disorders, implying disrupted cochlear ion transport functions may underlie the vascular problems proposed in some forms of immune-mediated hearing loss.
Regulating Debilitating Emotions in the Context of Performance: Achievement Goal Orientations, Achievement-Elicited Emotions, and Socialization Contexts
Authors: Tyson Diana F. , Linnenbrink-Garcia Lisa , Hill Nancy E.
Published: November 2009

A theoretical framework that incorporates emotional responses and emotion regulation into achievement goal theory is proposed as an alternative view to understanding the inconsistent pattern of findings linking achievement goal orientations to academic outcomes. In this critical review and synthesis, the relation of achievement goal orientations to debilitating emotional responses, as well as the use of emotion regulation strategies to alter debilitating emotions, is examined. Although mastery, performance-approach, and performance-avoidance goal orientations are considered, the regulation of debilitating emotions is proposed as especially critical for understanding how performance-approach goal orientations relate to academic-related processes and achievement. Finally, this framework is broadened to incorporate research on how the social context and intraindividual factors shape the resultant pattern of achievement goal orientations, emotional responses, and emotion regulation.
Transanal Endoscopic Microsurgery for Local Excision of Rectal Lesions: Is There a Learning Curve
Authors: Koebrugge B. , Bosscha K. , Ernst M.F.
Published: November 2009

Background: Transanal endoscopic microsurgery (TEM) is a minimally invasive technique for the local resection of benign and stage T1 rectal lesions in selected patients, associated with lower morbidity and mortality rates than open surgery. We present our initial results and assess whether experience influences outcome after TEM. Methods: This was a prospective descriptive survey. All patients undergoing TEM for tubulovillous adenoma or carcinoma between 2002 and 2007 were included. Results: A total of 105 patients were included. Median age was 68 years. Median distance of the lesion from the anal verge was 7.0 cm; median operating time was 90 min. In 10 patients, the peritoneum was opened. Six procedures were converted to (low) anterior resections. Postoperative staging revealed 77 tubulovillous adenomas, 22 stage T1, 5 stage T2 and 1 stage T3 carcinomas; tumor resection was radical in 86%. The postoperative complication rate was 7.6%. Length of hospital stay, operating time and complications significantly diminished over time. After a median follow-up of 27 months, 8 recurrences occurred (7.6%). Conclusion: TEM is a safe technique with low morbidity and recurrence rates. Over time, experience leads to a reduction in operation time, lenght of patients’ hospital stay and complication rate. TEM remains the treatment of choice for benign lesions and stage T1 rectal carcinomas in selected patients.
Histamine Stimulates Interleukin-6 Production through Histamine H1 Receptors in Human Amnion Cells
Authors: Morimitsu Akiko , Sumigama Seiji , Kotani Tomomi , Mano Yukio , Suzuki Kanako , Araki-Taguchi Masako , Yamamoto Eiko , Hayakawa Hiromi , Okada Mayumi , Itakura Atsuo , Kikkawa Fumitaka
Published: November 2009

Background/Aims: Previous studies have stated that maternal allergic diseases are associated with increased risk of preterm labor/delivery, but the underlying mechanisms remain unclear. This study tested the hypothesis that histamine induces interleukin (IL)-6 production in amnion cells. Methods: Using cultured human amnion cells, we examined expression of histamine receptors and effects of histamine on IL-6 production. Results: Reverse transcription-polymerase chain reaction and Western blotting revealed expression of histamine H1 receptor (H1R) and H2 receptor (H2R) in human amnion. Histamine stimulation significantly increased concentrations of IL-6 in conditioned medium, as did tumor necrosis factor-α and IL-1β in positive controls. In addition, the H1R antagonist olopatadine significantly blocked histamine-induced production of IL-6, whereas the H2R antagonist ranitidine did not. Conclusion: Histamine appears to induce IL-6 production through H1R in human amnion cells.
Simultaneous Use of Functional Tractography, Neuronavigation-Integrated Subcortical White Matter Stimulation and Intraoperative Magnetic Resonance Imaging in Glioma Surgery: Technical Note
Authors: Gasco Jaime , Tummala Sudhakar , Mahajan Ninad M. , Weinberg Jeffrey S. , Prabhu Sujit S.
Published: November 2009

The importance of preserving function during glioma surgery cannot be overemphasized. There are a number of techniques utilized including functional MRI, direct electrophysiological monitoring and functional neuronavigation to maximize and safely resect gliomas. The intraoperative MRI is an extremely valuable tool and adds to the neurosurgeon’s armamentarium. Combining these technologies will enhance the safety and efficacy of glioma surgery. This is the first report in the literature where we successfully combine both functional neuronavigation and subcortical stimulation, using a single probe to safely resect a recurrent glioblastoma.
Estimation of Brain Deformation for Volumetric Image Updating in Protoporphyrin IX Fluorescence-Guided Resection
Authors: Valdés Pablo A. , Fan Xiaoyao , Ji Songbai , Harris Brent T. , Paulsen Keith D. , Roberts David W.
Published: November 2009

Introduction: Fluorescence-guided resection (FGR) of brain tumors is an intuitive, practical and emerging technology for visually delineating neoplastic tissue exposed intraoperatively. Image guidance is the standard technique for producing 3-dimensional spatially coregistered information for surgical decision making. Both technologies together are synergistic: the former detects surface fluorescence as a biomarker of the current surgical margin while the latter shows coregistered volumetric neuroanatomy but can be degraded by intraoperative brain shift. We present the implementation of deformation modeling for brain shift compensation in protoporphyrin IX FGR, integrating these two sources of information for maximum surgical benefit. Methods: Two patients underwent FGR coregistered with conventional image guidance. Histopathological analysis, intraoperative fluorescence and image space coordinates were recorded for biopsy specimens acquired during surgery. A biomechanical brain deformation model driven by intraoperative ultrasound data was used to generate updated MR images. Results: Combined use of fluorescence signatures and updated MR image information showed substantially improved accuracy compared to fluorescence or the original (i.e., nonupdated) MR images, detecting only true positives and true negatives, and no instances of false positives or false negatives. Conclusion: Implementation of brain deformation modeling in FGR shows promise for increasing the accuracy of neurosurgical guidance in the delineation and resection of brain tumors.
A Meta-Analysis Evaluating the Impact of Chitosan on Serum Lipids in Hypercholesterolemic Patients
Authors: Baker William L. , Tercius Alix , Anglade Moise , White C. Michael , Coleman Craig I.
Published: November 2009

Background/Objective: Chitosan is increasingly being used in the United States as an over-the-counter cholesterol-lowering agent. The positively charged amino groups of chitosan may have the ability to bind negatively charged molecules such as lipids and bile acids, inducing a greater fractional excretion in the feces. To better characterize the impact of chitosan on serum lipids in hypercholesterolemic patients, we performed a meta-analysis of randomized controlled trials. Methods: A systematic literature search of Medline, Embase, Cochrane Central and the Natural Medicines Comprehensive Database was conducted from the earliest possible date through May 2008. Trials were included in the analysis if they were randomized, placebo-controlled trials of chitosan in hypercholesterolemic patients and reported efficacy data on total, low-density lipoprotein (LDL), high-density lipoprotein (HDL) cholesterol or triglycerides. The weighted mean difference (WMD) of the change from baseline (in milligrams per deciliter) with 95% confidence interval was calculated as the difference between the mean in the chitosan and placebo groups using a random-effects model. Results: Six studies (n = 416 patients) met the inclusion criteria. Upon meta-analysis, the use of chitosan significantly lowered total cholesterol [WMD, –11.59 mg/dl (–21.45 to –1.73), p = 0.02] but not LDL cholesterol, HDL cholesterol or triglycerides. Conclusions: Based upon the currently available literature, we can only say that chitosan beneficially affects total cholesterol with 95% confidence. Additional, larger randomized controlled trials are needed to better characterize the effect of chitosan on other lipoproteins.
A Review of Nerve Conduction Studies in Cases of Suspected Compression Neuropathies of the Upper Limb
Authors: Neligan A. , O’Sullivan S.S. , Mullins G.M. , McCarthy A. , Kowalski R.G. , Kinsella J. , McNamara B.
Published: November 2009

Introduction: Entrapment neuropathies, particularly those affecting upper limbs, are common reasons for referral for nerve conduction studies (NCS). However, concordance between clinical findings and NCS findings, especially in patients being considered for intervention including decompressive surgery, has not been assessed. Methods: We conducted a retrospective study using records from a tertiary referral centre’s neurophysiology database. We aimed to establish the proportions of agreement between the suspected clinical diagnosis as defined by the referring clinician and NCS findings in the setting of an upper limb entrapment neuropathy. Results: Of the 571 referrals for NCS, suspected bilateral carpal tunnel syndrome was the commonest reason for referral (30.5%). In total, there was 51.5% concordance between suspected clinical diagnosis and NCS findings. Patients with NCS evidence of an entrapment neuropathy (n = 437) were more likely to be older compared to those with normal studies (54.0 ± 15.6 years vs. 45.9 ± 13.4 years, p < 0.001). Those with normal NCS findings were more likely to be female (72%, p = 0.001). An alternative or additional diagnosis was found in 14%. Conclusion: This study raises concerns regarding the appropriateness of referral for decompressive surgery based on clinical diagnosis alone as many have an additional or alternative diagnosis as suggested by NCS findings.