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Synapse devices, pivotal components in neuromorphic computing, demonstrate unique properties that are essential for advanced computing systems. These devices, characterized by their metal/resistive layer/metal structure, rely heavily on active layer material. One important challenge in developing synapse devices for artificial neural networks lies in constructing these networks at a hardware level to achieve in-memory computing, enabling the efficient processing of information while minimizing power consumption. Herein, we present a rational design and in situ synthesis of two-dimensional (2D/2D) heteronanostructures intricately integrating Ti-based metal carbide as Ti-MXene (Ti3C2) with copper-based metal–organic framework as Cu-tetrakis (4-carboxyphenyl) porphyrin (Cu-TCPP) through van der Waals interactions to form a hybrid as [Ti3C2@Cu-TCPP] (1). The hybrid exhibits synergistic properties of both counterparts with an intricate hierarchical structure, ensuring exceptional stability and remarkable conductivity, fundamental for the progression of advanced neuromorphic devices. The resultant hybrids show an advanced neuromorphic device with comprehensive comparative analysis using DC I–V sweeps was conducted to evaluate different device types, focusing on parameters such as the high-resistance state, low-resistance state, and on/off ratio. Results demonstrated that Ti3C2@Cu-TCPP@PVA-based devices exhibited an impressive on/off ratio of approximately 102, outperforming Cu-TCPP@PVA and Ti3C2@PVA-based devices. This highlights the superior performance of Ti3C2@Cu-TCPP@PVA and its potential for advanced applications in neural network systems. Furthermore, the conduction mechanism was elucidated, revealing the dominance of the space-charge limited conduction mechanism during the SET process and the Schottky emission mechanism during the RESET process.

This study investigates the temperature coefficient of resistance (TCR) of a-Si:H according to process conditions to find out the temperature-dependent mechanism for microbolometer applications. Four types of a-Si:H films were prepared using plasma-enhanced chemical vapor deposition (PECVD) by adjusting the SCCM of the doping gases: high B2H6 (B1), low B2H6 (B2), high PH3 (P1), and low PH3 (P2). Secondary ion mass spectroscopy analysis is performed to confirm the doping concentration. N-type (P1 or P2) seems to be less favorable for improving the channel conductance, but it has a large TCR meaning that P2 has the highest temperature dependency as well as the largest absolute TCR value. After preannealing in D2 atmospheres, P1 and P2 show a significant reduction in the TCR. In addition, ${R}_{\text {C}}$ is observed to be reduced with TCR after postmetal annealing. The 1/ ${f}$ noise is also correlated with TCR and is found to have a tradeoff relation. These results imply that the TCR is primarily influenced by the trap states in a-Si:H film. Based on the experimental results, thermal-assisted transport through the local potential barrier is suggested for the temperature dependency of TCR in a-Si:H.

In this brief, a two-stage low-noise amplifier (LNA) was developed in which the noise-matching network of a high-pass filter (HPF) structure is applied to both stages. As the HPF noise matching network is used in both stages, the noise figure of the proposed LNA can be reduced compared to that of the conventional LNA. In particular, the noise figure is improved in the high-frequency region. To verify this development, a two-stage common-source LNA was implemented using 0.18- $\mu \text{m}$ bulk complementary metal oxide semiconductor technology. The fabricated LNA achieved an average noise figure of 2.6 dB (minimum noise figure of 2.23 dB at 3.95 GHz) and a peak gain of 14.19 dB. In addition, the LNA has an input 1-dB compression point (IP1dB) of −12 dBm and a third-order input intercept point (IIP3) of +2.0 dBm at 3.5 GHz, consumes 16 mA with a 0.9 V supply, and has an area of 0.7 mm2.

Mitochondrial reactive oxygen species (ROS) play an important role in diabetes complications, including diabetic nephropathy (DN). Plasma free fatty acids (FFAs) as well as glucose are increased in diabetes, and peroxisomes and mitochondria participate in FFA oxidation in an interconnected fashion. Therefore, we investigated whether deficiency of catalase, a major peroxisomal antioxidant, accelerates DN through peroxisomal dysfunction and abnormal renal FFA metabolism. Diabetes was induced by multiple injections of low-dose streptozotocin into catalase knock-out (CKO) and wild-type (WT) C57BL/6 mice. Murine mesangial cells (MMCs) transfected with catalase small interfering RNA followed by catalase overexpression were used to further elucidate the role of endogenous catalase. Despite equivalent hyperglycemia, parameters of DN, along with markers of oxidative stress, were more accelerated in diabetic CKO mice than in diabetic WT mice up to 10 weeks of diabetes. CKO mice and MMCs showed impaired peroxisomal/mitochondrial biogenesis and FFA oxidation. Catalase deficiency increased mitochondrial ROS and fibronectin expression in response to FFAs, which were effectively restored by catalase overexpression or N-acetylcysteine. These data provide unprecedented evidence that FFA-induced peroxisomal dysfunction exacerbates DN and that endogenous catalase plays an important role in protecting the kidney from diabetic stress through maintaining peroxisomal and mitochondrial fitness., Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide and an independent risk factor for cardiovascular morbidity and mortality (1). DN is characterized by albuminuria, decreased glomenflar [...]

Introduction: Infective endocarditis (IE) is a severe and fatal infection with high in-hospital and overall mortality rates of approximately up to 30%. Valve culture positivity was associated with in-hospital mortality and postoperative complications; however, few studies have analyzed the relationship between valve cultures and overall mortality over a long observation period. This study aimed to compare the association of valve culture positivity with overall mortality in patients with IE who underwent valve surgery. Methods: A total of 416 IE patients admitted to a tertiary hospital in South Korea from November 2005 to August 2017 were retrospectively reviewed. A total of 202 IE patients who underwent valve surgery and valve culture were enrolled. The primary endpoint was long-term overall mortality. Kaplan–Meier curve and Cox proportional hazards model were used for survival analysis. Results: The median follow-up duration was 63 (interquartile range, 38–104) months. Valve cultures were positive in 22 (10.9%) patients. The overall mortality rate was 15.8% (32/202) and was significantly higher in valve culture-positive patients (36.4%, p= 0.011). Positive valve culture [hazard ratio (HR) 3.921, p= 0.002], Charlson Comorbidity Index (HR 1.181, p= 0.004), Coagulase-negative staphylococci (HR 4.233, p= 0.001), new-onset central nervous system complications (HR 3.689, p< 0.001), and new-onset heart failure (HR 4.331, p= 0.001) were significant risk factors for overall mortality. Conclusions: Valve culture positivity is a significant risk factor for long-term overall mortality in IE patients who underwent valve surgery. The importance of valve culture positivity needs to be re-evaluated, as the valve culture positivity rate increases with increasing early surgical intervention.

Two-dimensional (2D) transition-metal dichalcogenides have attracted significant attention as gas-sensing materials owing to their superior responsivity at room temperature and their possible application as flexible electronic devices. Especially, reliable responsivity and selectivity for various environmentally harmful gases are the main requirements for the future chemiresistive-type gas sensor applications. In this study, we demonstrate improved sensitivity of a 2D MoS2-based gas sensor by controlling the Schottky barrier height. Chemical vapor deposition process was performed at low temperature to obtain layer-controlled 2D MoS2, and the NO2gas responsivity was confirmed by the fabricated gas sensor. Then, the number of MoS2layers was fixed and the types of electrode materials were varied for controlling the Schottky barrier height. As the Schottky barrier height increased, the NO2responsivity increased, and it was found to be effective for CO and CO2gases, which had little reactivity in 2D MoS2-based gas sensors.

It is controversial to what extent serum uric acid (SUA) is associated with mortality in patients with chronic kidney disease undergoing hemodialysis (HD). We analyzed the predictive role of SUA in the mortality of diabetic and nondiabetic chronic kidney disease patients starting on maintenance HD therapy.

Silicon-oxide-nitride-oxide-silicon (SONOS) memory devices were fabricated from polycrystalline silicon (poly-Si) using the solid phase crystallization (SPC) method for use in a low-power system-on-panel (SOP) display. In these poly-Si SONOS memories, oxide or nitride was used as a buffer layer. The electrical characteristics, such as the threshold voltage (VT), subthreshold slope (SS) and transconductance (gm), were determined for each SONOS device. To interpret the characteristics of both poly-Si devices, x-ray diffraction (XRD) measurements and flicker noise analysis were conducted. The results show that the poly-Si SONOS on the oxide layer has better electrical, memory characteristics, such as turn-on speed and gm, program/erase, endurance and data retention than that on the nitride layer. From the XRD measurements, it is shown that the grain size of the poly-Si on the oxide layer is larger than that on the nitride layer. From the flicker noise analysis, the poly-Si device on oxide was shown to have less traps or defects in the channel layer than that on nitride.

In this work, we analyzed and correlated the hysteresis characteristics and instability under negative bias temperature instability (NBTI) stress in p-channel low-temperature poly-silicon (LTPS) thin-film transistors (TFTs). Positive VTHshifts were observed under the NBTI stress. The hysteresis does not appear to be affected by the NBTI stress; however, when the VG stress voltage is −40 V at 100°C, the hysteresis increases as the stress time increases and VTHshifts with sub-threshold slope (SS) degradation. The hysteresis may increase under the extreme stress condition due to the generation of trap-states.

In this paper, electrical analysis was carried out on ZnO thin-film transistors (TFTs) to investigate the effects of the Al2O3interlayer between the ZnO active-layer and the SiO2gate insulator. The Al2O3interlayer was deposited via atomic layer deposition. From the electrical analysis, it was found that the Al2O3interlayer improves the electrical properties, such as the subthreshold slope and on/off-current ratio. The stability degradation under positive bias stress, however, is severe in TFTs with an Al2O3interlayer. According to the crystallographic view, the crystal structures in a ZnO film on Al2O3are prone to align in the (002) direction compared with ZnO on SiO2, and can attract more oxygen ions because of the Zn polar, which degrades the stability of devices.

In this paper, the electricalcharacteristics of Ergermanideschottkyjunction werestudied for source / drain of n-typeschottky barrier Ge MOSFET.Ergermanideshowed the lowest ideality factor at RTP temperature of 600°C among the applied temperature range. When RTP temperature was increased, barrier height and work function of Ergermanidebecame similar to those of Er2Ge3. From the analysis of the leakage current, it is shown that the Poole-Frenkel barrier lowering was dominant at RTP 600°C and the influence of the Schottky barrier lowering was decreased as RTP temperature increased. The electrical characteristics of Ergermanideare very sensitive to the RTP temperature andclosely related tothe trapsites which are generated by germanidation.

In this paper, Ni-silicide formed by co-sputtering of Ni and Ti on a boron cluster (BF2, B18H22) implanted ultra-shallow source/drain for MOSFET (metal oxide semiconductor field effect transistor) is proposed. Ni and Ti with a TiN capping layer were deposited by co-sputtering on boron cluster implanted wafer. By analysis of its sheet resistance, interfacial structures, surface morphological stability, and phase formation after post-silicidation annealing, thermal stability of Ni-silicide was found to be improved a lot.

This paper discusses the 3-level charge pumping method in planar-type Silicon-Oxide-High-k-Oxid e-Silicon (SOHOS) and Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) devices to find out the reason for degradation of data retention properties. In the CP thechnique, a pulse is applied to the gate of the MOSFET which alternately fills the traps withe electrons and holes, thereby causing a recombination current Icp to flow in the substrate. A 3-level charge pumping method may be used to determine not only interface trap densities but also capture cross sections as a function of trap energy. By applying this method, SOHOS device found to have a higher interface trap density than SONOS device. Therefore, degradation of data retention characteristics is attributed to the many interface trap sites.

. In this paper, dielectric relaxation and reliability of high capacitance density metal-insulator-metal (MIM) capacitor using Al2O3-HfO2-Al2O3 sandwiched structure were analyzed. It is shown that multilayer MIM capacitor provides high capacitance density and low dissipation factor at room temperature. The dielectric relaxation voltage shows little dependence on the capacitor area. The capacitance density (C0) increases and quadratic voltage coefficient (α) decreases as a function of stress time under constant voltage stress (CVS) because of the charge trapping effect in the high-k dielectric.

For the system on panel applications, we fabricated and analyzed the polycrystalline silicon (poly-Si) silicon-oxide-nitride-oxide-silicon (SONOS) memory device on different buffer layer such as oxide or nitride. The threshold voltage (VT) and transconductance (gm) are extracted from each device and the X-Ray Diffraction (XRD) measurement is carried out to interpret these characteristics. The results show the device on oxide layer has higher mobility and lower VT than on nitride layer. From the XRD spectra, it can be explained by the fact that the grain size of poly-Si on oxide layer has larger than on nitride layer. The both devices show program/erase characteristics as the potential of SOP memory devices.

RF characteristics of metal-insulator-metal (MIM) capacitors with SiO2/HfO2/SiO2 (SHS) were investigated using an equivalent circuit model that is associated with the main impedance ZMIM.cap and the substrate-related conductance Ysub. However, the parasitic capacitance in Ysub was lower than that of another element component in ZMIM.cap, which makes difficult for accurate RF modeling because the parasitic component was dominant at high frequency regions. As low parasitic component is eliminated from the modeling, the extracted capacitance for SHS MIM capacitor was stable up to 20 GHz. The Q-factor and resonant frequency (fr) point of SHS structure are 23.9 at 1 GHz and 9.76 GHz, respectively.

In this paper, the electrical and physical analysis is carried out to investigate the effect of Al2O3 capping layer on ZnO film using atomic layer deposition. ZnO TFTs shows the metallic conduction behavior as Al2O3 capping layer thickness increases. From SIMS analysis, it is found out that the diffusion of Al into ZnO film is enhanced according to Al2O3 capping layer thickness. Moreover, the defects related to oxygen such as oxygen vacancy increase from XPS analysis and ZnO films reveal less compressive stress by substitution of Zn with Al form XRD analysis. That is, the metallic conduction behavior of ZnO TFTs with Al2O3 capping layer can be explained due to increase in the carrier concentration in ZnO channel layer from oxygen vacancy and substitution of Zn with Al.

Abstract: Due to the necessity of associating high-purity monocrystalline silicon and lower-cost multicrystalline silicon wafers, the monocrystalline-like silicon technique is used as a promising method for solar-cell fabrication. The grain orientation of this material is composed of both 〈111〉 and 〈100〉 orientations. As a result of a combination for properties on the basis of two types of materials, silicon surface texturing was carried out by using alkaline (NaOH) chemical and reactive ion etching (RIE) texturing. In this research, we investigated the optical and the electrical properties of silicon surfaces prepared by using different texturing processes. By using the alkaline and RIE texturing processes, we obtained a fill factor of 78.6% with a conversion efficiency of 17.2% for a monocrystalline-like silicon wafer with an active surface area of 243 cm2. Compared to alkaline texturing, this conversion efficiency shows an increase of 0.5%. Thus, large-area monocrystalline-like silicon solar cells with high efficiency and low cost can be fabricated.

Bottom-gate staggered amorphous indium--gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) with Si3N4and Si3N4/Al2O3gate dielectrics were fabricated on glass substrates to investigate the electrical instabilities. An anomalous hump was observed only in the Si3N4device under the positive bias stress. To analyze the anomalous hump, the transmission electron microscope (TEM) images and the two-dimensional (2D) device simulation were investigated, and results showed that insulator thinning and electric field enforcement at the gate edge are not the causes of the hump. In the time dependence of $\Delta V_{\text{TH}}$ under stress, Si3N4/Al2O3and Si3N4devices follow the stretched-exponential and logarithmic time dependences, respectively. That is, in the Si3N4/Al2O3device, the trapped electrons are spatially redistributed easily in dielectrics or near the interface, which seems to suppress the hump.

Objective Accumulation of visceral fat is one of the major risk factors for the development of cardiovascular disease in peritoneal dialysis (PD) patients. Adiponectin, an adipokine commonly regarded as a negative indicator of metabolic disease, is reported to be downregulated in its gene level in end-stage renal disease patients. Since excessive fat deposit is involved in increased reactive oxygen species (ROS), PD solution (PDS) may contribute to ROS production, resulting in dysregulation of adiponectin. In this study, we tested our hypothesis that oxidative stress induced by PDS may play a role in the regulation of adiponectin.Methods Commercial PDS containing 3.86% glucose (20 - 30 mL) was administered to SD rats for 12 weeks with and without N-acetylcysteine (NAC; 10 mmol/L). ELISA was used to quantify adiponectin in plasma and spent dialysate. For in vitrostudies, fully differentiated 3T3-L1 adipocytes and adipocytes isolated from abdominal fat were treated with a high glucose solution, PDS, and H2O2. Adiponectin levels in the conditioned media were measured by ELISA and immunoblot assays. The mRNA levels of adiponectin in mature adipocytes were examined using real-time RT-PCR.Results The levels of adiponectin in plasma and spent dialysate were significantly downregulated by PDS and this effect was suppressed by NAC. In 3T3-L1 adipocytes, adiponectin secretion was inhibited by 50 mmol/L glucose, PDS diluted 2-fold, and H2O2(200 μmol/L). In addition, H2O2downregulated expression of adiponectin mRNA and secretion of adiponectin oligomer complexes.Conclusions Our data suggest that ROS induced by conventional glucose-based PDS may contribute to pathophysiological changes in abdominal fat and down regulate adiponectin secreted from adipocytes during long-term PD.

In this paper, the dependence of low-frequency (LF) noise, such as $1/f$ noise and random telegraph signal (RTS) noise, and the hot carrier reliability in n-channel metal--oxide--semiconductor field-effect transistors (NMOSFETs) on channel stress has been studied. The normalized noise power spectral density ($S_{I_{\text{D}}}/I_{\text{D}}{}^{2}$) and RTS amplitude of NMOSFETs with compressive channel stress are greater than those with tensile channel stress because the active traps contributing to RTS noise with compressive stress are distributed closer to the Si/SiO2interface. LF noise characteristics, as well as device performance are enhanced by introducing tensile channel stress to nanoscale NMOSFETs. However, it is shown that device degradation caused by tensile channel stress is greater than that caused by compressive channel stress under channel hot carrier (CHC) and drain avalanche hot carrier (DAHC) stress conditions. Therefore, concurrent consideration of reliability and LF noise characteristics as well as dc device performance is necessary in channel strain engineering for next generation complementary metal--oxide--semiconductor field-effect transistors (CMOSFETs) especially for analog or mixed signal integrated circuit applications.

The electronic transport properties of the thin film transistor (TFT) devices consisting of carboxyl-modified single-walled carbon nanotube (c-SWCNT) network are studied. This work is focused on the analysis of the effect of chemical treatment on the electronic transport properties from these devices. The c-SWCNT thin film transistor (c-SWCNT TFT) devices were fabricated by a directed assembly method based on electrostatic interaction between amino-functionalized substrate and c-SWCNTs. The electrical characteristics of c-SWCNT TFTs were measured at room temperature. From the Raman results and the transport characteristics of c-SWCNT TFT devices, the transport mechanism in these devices can be accounted that the deep levels arising from vacancy-adatom complex induced the changes in the electronic band structure of SWCNTs.

The properties of functionalized single-walled carbon nanotube (f-SWCNT) supernatant samples obtained through steps of acid oxidation-centrifugation-decantation were characterized by spectroscopic tools. Fourier transform IR spectroscopy provided evidence for the chemical and structural variations generated on the f-SWCNTs within each supernatant sample. The results from UV-visible near-IR spectroscopy revealed that the density difference of the carbonaceous impurity with functional groups on the f-SWCNTs contributed to the attenuation of electrical conductivity. In the Raman results, the shift of frequency in the radial breathing mode (RBM) was associated with an increase in diameter of the f-SWCNTs and a decrease in RBM intensity was attributed to the depletion of valence band electrons. The redshift of the tangential mode indicates the reduction in the bandgaps of the f-SWCNTs by the decrease in carbonaceous impurity.

Excessive accumulation of extracellular matrix (ECM) in the kidneys and epithelial-to-mesenchymal transition (EMT) of renal tubular epithelial cells contributes to the renal fibrosis that is associated with diabetic nephropathy. Histone deacetylase (HDAC) determines the acetylation status of histones and thereby controls the regulation of gene expression. This study examined the effect of HDAC inhibition on renal fibrosis induced by diabetes or transforming growth factor (TGF)-β1 and determined the role of reactive oxygen species (ROS) as mediators of HDAC activation. In streptozotocin (STZ)-induced diabetic kidneys and TGF-β1-treated normal rat kidney tubular epithelial cells (NRK52-E), we found that trichostatin A, a nonselective HDAC inhibitor, decreased mRNA and protein expressions of ECM components and prevented EMT. Valproic acid and class I-selective HDAC inhibitor SK-7041 also showed similar effects in NRK52-E cells. Among the six HDACs tested (HDAC-1 through -5 and HDAC-8), HDAC-2 activity significantly increased in the kidneys of STZ-induced diabetic rats and db/dbmice and TGF-β1-treated NRK52-E cells. Levels of mRNA expression of fibronectin and α-smooth muscle actin were decreased, whereas E-cadherin mRNA was increased when HDAC-2 was knocked down using RNA interference in NRK52-E cells. Interestingly, hydrogen peroxide increased HDAC-2 activity, and the treatment with an antioxidant, N-acetylcystein, almost completely reduced TGF-β1-induced activation of HDAC-2. These findings suggest that HDAC-2 plays an important role in the development of ECM accumulation and EMT in diabetic kidney and that ROS mediate TGF-β1-induced activation of HDAC-2.

The 50 kDa glycoprotein plasminogen activator inhibitor 1 (PAI-1) is the major physiological inhibitor of tissue-type and urokinase-type plasminogen activator. These two molecules convert inactive plasminogen into its fibrin-degrading form, plasmin. Plasma and tissue concentrations of PAI-1 are extremely low under normal circumstances but increase under pathologic conditions. This increase is mediated by many factors, including reactive oxygen species. Increased PAI-1 activity is associated with an increased risk of ischemic cardiovascular events and tissue fibrosis. Whereas the antifibrinolytic property of PAI-1 derives mainly from its inhibition of serine proteases, its profibrotic actions seem to derive from a capacity to stimulate interstitial macrophage recruitment and increase transcription of profibrotic genes, as well as from inhibition of serine proteases. Despite studies in mice that lack or overexpress PAI-1, the biological effects of this molecule in humans remain incompletely understood because of the complexity of the PAI-1–plasminogen-activator–plasmin system. The cardioprotective and renoprotective properties of some currently available drugs might be attributable in part to inhibition of PAI-1. The development of an orally active, high-affinity PAI-1 inhibitor will provide a potentially important pharmacological tool for further investigation of the role of PAI-1 and might offer a novel therapeutic strategy in renal and cardiovascular diseases.

In this paper, novel Ni Germanosilicide technology using the 1%-nitrogen doped Ni and pure Ni stack structure has been proposed for nano-scale CMOS technology. The Ni Germanosilicide is formed on the Si0.8Ge0.2 layer which is known as an optimal composition for strained silicon application. Proposed structure showed much better thermal stability than pure Ni case. Silicide characteristics such as the sheet resistance, the interface uniformity of silicide/SiGe, surface roughness, and depth profile of the Ni, Si, and Ge showed little degradation even with the high temperature post-silicidation annealing at 600 [removed info] for 30 min. Therefore, the proposed method is highly promising for nano-scale CMOS technology.

In this paper, it is presented that flicker (1/f) noise of ultra thin gate oxide can be improved by initial oxidation and subsequent plasma nitridation(PN). PN which raises Nitrogen peak upward from the Si/Oxide interface to gate polysilicon/Oxide interface is adopted mainly to improve the life time such as Negative-Bias Temperature Instability (NBTI) and hot carrier in Nano CMOS technology. Three different types of initial oxidation prior to plasma nitridation are investigated. One is slow thermally grown oxide(STO) in very small Oxygen ambient, another is rapid thermally grown oxide(RTO) and the other is grown in Nitrous oxygen ambient (NO). Oxide thickness of all splits is about 14.5< Then, it is shown that STO has the lowest drain current noise power (Sid) among the splits. The interface trap densitie (Dit) of each oxide is characterized using charge pumping method. Finally, we reached a conclusion that the 1/f noise can be significantly reduced by initial STO and Plasma Nitridation in Nano CMOS technology.

In this paper, the electrical properties of NiSi have been characterized using multi capping layer structure for nano CMOS application. We have investigated the formation and thermal stability of Ni silicide using Ni, Ti and TiN capping layers (Ti/Ni/TiN) as a function of Rapid Thermal Processing (RTP) temperature. It was shown that the NiSi with multi capping layer has lower sheet resistances than that with single capping (TiN) layer. NiSi with multi capping layer also showed much better thermal stability. It was verified that the formation Ni-Ti-Si ternary like layer at the top region of thhe NiSi results in improvement of thermal stability.

We investigated the effect of SiO[removed info]cap layer on the thermal stability of nickel and nickel-cobalt silicide by measuring its sheet resistance. The stability of nickel silicide was deteriorated as a function of annealing temperature, while that of nickel-cobalt silicide was not. In case of both silicides, the SiO[removed info]cap layer improved the stability. Tensile stress from the difference of thermal expansion coefficients between SiO2 and nickel silicide may suppress the agglomeration of nickel silicide.

Dialysis patient mortality remains high, and this high mortality may be due to many factors. In peritoneal dialysis (PD) patients, old age, co-morbid diseases, malnutrition, low residual renal function (RRF) and a high peritoneal transport rate have been shown to influence survival, but the relative importance of these factors may differ between different patient populations. Besides, centre practice patterns may differ between centres and may influence patient survival. In addition, the literature suggests that dialysis patient survival may be better in Asian than in Caucasian patients.

Objective To demonstrate the presence of an independent renin–angiotensin system (RAS) in the peritoneum and to determine the role of locally produced angiotensin (Ang) II in high glucose-induced upregulation of transforming growth factor (TGF)-β1 and fibronectin by human peritoneal mesothelial cells (HPMC).Methods In cultured HPMC, the expression of mRNAs for angiotensinogen, angiotensin-converting enzyme (ACE), Ang II type 1 receptor (AT1), and TGF-β1 was evaluated by real-time polymerase chain reaction; ACE, AT1, and fibronectin proteins by Western blot analysis; and Ang I, Ang II, and TGF-β1 proteins by ELISA. Dichlorofluorescein (DCF)-sensitive cellular reactive oxygen species (ROS) were measured by fluorometry.Results HPMC constitutively expressed all the components of RAS, and 50 mmol/L D-glucose (high glucose) significantly increased angiotensinogen, ACE, and AT1 mRNAs and ACE, AT1, and Ang II proteins. Ang II increased TGF-β1 and fibronectin protein expression and DCF-sensitive cellular ROS. Losartan prevented Ang II-induced increase in cellular ROS. Both losartan and captopril inhibited high glucose-induced upregulation of TGF-β1 and fibronectin expression in HPMC in a dose-dependent manner. Antioxidant catalase and NADPH oxidase inhibitor diphenyleneiodinium effectively inhibited Ang II-induced TGF-β1 and fibronectin protein expression.Conclusions The present data demonstrate that HPMC constitutively express RAS, that Ang II produced by HPMC mediates high glucose-induced upregulation of TGF-β1 and fibronectin expression, and that Ang II-induced TGF-β1 and fibronectin expression in HPMC is mediated by NADPH oxidase-dependent ROS. These data suggest that locally produced Ang II and ROS in the peritoneum may be potential therapeutic targets in peritoneal fibrosis during long-term peritoneal dialysis.

It has been established that malnutrition (MN) is a strong predictor of mortality in peritoneal dialysis (PD) patients. However, MN is often the consequence of co-morbid diseases (CMD), and the confounding effect of CMD on mortality in malnourished PD patients has not been clearly defined. In this study, we tested the hypothesis that MN without CMD may not be associated with significant mortality. This study was, therefore, designed to dissociate the influence of CMD on mortality in PD patients from that of MN.

ABSTRACTSThe purpose of this paper is to evaluate the characteristics of possible cracks induced on tunnel lining according to the magnitude and shape of applied loads. For a study on mechanical behavior and cracking characteristics of tunnel lining, down scaled models were tested in consideration of applied loading type, side confinement, double lining, opening behind the concrete lining and so. Total twenty-four specimens including single and double lining models were prepared with concrete and mortar mixes. The mechanical behavior of tested models was discussed based on cracking load, failure load, critical section and finally load-deflection curve. A dimensionless support reaction formula was derived to generalize the relationship of applied loads and resultant deflections. Furthermore, we tried to modify the current designed flexural moment formula of the linings.

♦ Objective To compare the effects of different peritoneal dialysis solutions (PDS) on secretion of vascular endothelial growth factor (VEGF), transforming growth factor-β1(TGFβ1), procollagen I C-terminal peptide (PICP), procollagen III N-terminal peptide (PIIINP), and fibronectin by cultured human peritoneal mesothelial cells (HPMC).♦ Design Using M199 culture medium as control, commercial PDS containing 1.5% or 4.25% glucose and 40 mmol/L lactate [Dianeal 1.5 (D 1.5) and Dianeal 4.25 (D 4.25), respectively; Baxter Healthcare, Deerfield, Illinois, USA]; PDS containing 1.5% or 4.25% glucose with 25 mmol/L bicarbonate and 15 mmol/L lactate [Physioneal 1.5 (P 1.5) and Physioneal 4.25 (P 4.25), respectively; Baxter]; and PDS containing 7.5% icodextrin [Extraneal (E); Baxter] were tested. Growth-arrested and synchronized HPMC were continuously stimulated for 48 hours by test PDS diluted twofold with M199, TGFβ11 ng/mL, or different concentrations of icodextrin. VEGF, TGFβ1, and fibronectin secreted into the media were analyzed by ELISA, and PICP and PIIINP by radioimmunoassay.♦ Results Dianeal 1.5, D 4.25, and P 4.25, but not P 1.5 and E, significantly increased VEGF secretion compared with control M199. D 4.25- and P 4.25-induced VEGF secretion was significantly higher than induction by D 1.5 and P 1.5, respectively, suggesting that high glucose may be involved in the induction of VEGF. Physioneal 1.5- and P 4.25-induced VEGF secretion was significantly lower than induction by D 1.5 and D 4.25, respectively, suggesting a role for glucose degradation products (GDP) in VEGF production. TGFβ1secretion was significantly increased by D 4.25 and E. Icodextrin increased TGFβ1secretion in a dose-dependent manner. All PDS tested significantly increased secretion of PIIINP compared with control. D 1.5- and D 4.25-induced PIIINP secretion was significantly higher than P 1.5, P 4.25, and E. Physioneal 4.25-induced PIIINP secretion was significantly higher than P 1.5, again implicating high glucose and GDP in PIIINP secretion by HPMC. There was no significant increase in PICP or fibronectin secretion using any of the PDS tested. Addition of TGFβ11 ng/mL into M199 control significantly increased VEGF, PICP, PIIINP, and fibronectin secretion by HPMC.♦ Conclusions The present study provides direct evidence that HPMC can secrete VEGF, TGFβ1, and PIIINP in response to PDS, and that HPMC may be actively involved in the development and progression of the peritoneal membrane hyperpermeability and fibrosis observed in long-term PD patients. This study also suggests that both high glucose and GDP in PDS may play important roles in inducing VEGF and PIIINP production/secretion by HPMC.

Objective To investigate the biocompatibility of “new” peritoneal dialysis (PD) solutions with bicarbonate/lactate buffer, non glucose osmotic agents (icodextrin or amino acids), neutral pH, and low levels of glucose degradation products (GDPs).Design Using M199 culture medium as a control, we compared conventional and new PD solutions with respect to their effects on the viability of human peritoneal mesothelial cells (HPMCs) [using lactate dehydrogenase (LDH) release], on DNA damage in HPMCs [using single-cell gel electrophoresis (Comet assay)], and on HPMC proliferation (using [3H]-thymidine incorporation). The experiments were performed after cell growth was synchronized by incubation with serum-free media for 24 hours. The PD solutions tested included commercial 1.5% glucose and 4.25% glucose solutions with 40 mmol/L lactate (D 1.5 and D 4.25, respectively), 7.5% icodextrin (E), 1.1% amino acid (N), 1.5% glucose solution in a triple-chambered bag (Bio 1.5), 1.5% glucose solution in a dual-chambered bag with neutral pH (Bal 1.5), and 1.5% glucose and 4.25% glucose solution containing 25 mmol/L bicarbonate and 15 mmol/L lactate (P 1.5 and P 4.25, respectively).Results When HPMCs were continuously exposed to undiluted PD solutions, D 1.5, D 4.25, P 4.25, and E increased LDH release by more than 60% at 24 hours. All PD solutions tested increased LDH release by more than 75% at 96 hours. With 2-fold diluted PD solutions, only D 4.25 significantly increased LDH release at 96 hours, though not at 24 hours. When cells were exposed to undiluted PD solutions for 60 min and allowed to recover in M199 for up to 96 hours, LDH release was significantly higher at 24 – 96 hours in E (55% – 69%) and D 1.5 (48% –72%) as compared with control [M199 (18%)]. Release of LDH was significantly lower with PD solutions containing lower levels of GDPs than those in D 1.5, suggesting that GDPs may have a role in cell viability. The D solutions (D 1.5 and D 4.25) and E solution also induced significant DNA damage. Both LDH release and DNA damage by D and E were significantly attenuated by adjusting the solution pH to 7.4, suggesting that low pH may be implicated in PD solution–induced DNA damage and cell death. When diluted 2-fold, D 1.5, D 4.25, and P 4.25 decreased [3H]-thymidine incorporation to 43%, 34%, and 41% of control, respectively, at 24 hours and to 45%, 26%, and 35% of control, respectively, at 96 hours. When cells were exposed to undiluted PD solutions for 5 minutes and allowed to recover in M199 for up to 96 hours, D 1.5 and P 4.25—but not D 4.25—significantly inhibited cell proliferation at 24 hours. This effect was sustained up to 96 hours.Conclusions The present in vitrodata demonstrate that PD solutions with low pH, or high levels of GDPs, or both, promote HPMC death and DNA damage, and that PD solutions with high osmolality inhibit cell proliferation. Solutions with neutral pH, amino acids, and “low GDPs” appear to be more biocompatible than conventional PD solutions. These results require confirmation in in vivoanimal and clinical studies.

Objective To evaluate the influence of initial peritoneal transport rate, serum albumin concentration, and comorbid diseases on continuous ambulatory peritoneal dialysis (CAPD) patient survival.Design A prospective single-center study with a long-term follow-up.Patients A total of 213 consecutive CAPD patients, who underwent a peritoneal equilibration test (PET) at a mean of 7 days (range 3 – 30 days) after beginning CAPD, were included in this study. One hundred twenty patients were male, 116 patients had comorbid diseases, and mean age was 49.5 years (range 18 – 76 years).Methods A modified PET was performed using 4.25% glucose dialysis solution. Based on the dialysate-to-plasma creatinine concentration ratio at 4 hours’ dwell (D4/P4Cr, 0.62 ± 0.14), patients were divided into high (H), high-average (HA), low-average (LA), or low (L) transporters.Results Of 213 patients, 16.9% were classified as H transporters, 30.5% as HA, 36.6% as LA, and 16.0% as L transporters. The H transporter group had a higher proportion of men, higher proportion of patients with comorbid diseases, lower initial serum albumin concentration, lower D4/D0glucose, and lower drained volume. The initial D4/P4Cr correlated with initial serum albumin (r= –0.35, p< 0.001). The patients with comorbid diseases had lower initial serum albumin and higher initial D4/P4Cr. On Kaplan–Meier analysis, 2-year patient survival of group H was significantly lower compared to the other groups combined (57.1% vs 79.5%, p= 0.009). On Cox proportional hazards analysis, age, comorbid diseases, initial serum albumin concentration, and initial D4/P4Cr were found to be independent risk factors for mortality. However, in the patients without comorbid diseases, patient survival was not different between group H and the other transport groups combined (p> 0.05), and only age was found to be an independent risk factor for mortality.Conclusion These data suggest that a high peritoneal transport rate at initial PET is associated with high mortality, and that this is in part due to an increased prevalence of comorbid disease in H transporters. These H transporters with comorbid diseases represent a subset of patients with an especially poor prognosis. In patients without comorbid diseases, high transport status or low serum albumin concentration was not an independent risk factor for mortality.

ABSTRACTPhotogrammetry was initially confined to the measuring of terrestrial or ground photographs for map-making purposes, but it is applicable to all sciences that depend on reliable geometric measurements of physical quantities in a fixed or transitory state. Whether stereophotogrammetry was a possible and practical method for investigating rock discontinuity orientation data was the main discussion point of this paper, and the topic was broken into several parts as follows. Firstly, the details of obtaining rock discontinuity orientation data by stereophotogrammetric methods were described, and the advantages of the stereophotogrammetric method were discussed. Secondly, theory of stereophotogrammetry is introduced briefly. Thirdly, model test was performed following the procedure under the condition of horizontal camera direction and lowered camera direction and finally, error sources were analyzed. Finally, field test was performed to verify the applicability of the method. Two types of model tests were performed, case 1 and case 2. Model was set for its back-board to be perpendicular to horizontal plane. In case 1, photographs were taken in the horizontal camera direction, which means the camera direction was parallel to the horizontal plane. In case 2, photographs were taken in a 20° downward camera direction, which means that the camera direction was 20° lower than the horizontal plane. The roots of MSE (mean squared error) in dip for case 1 was 3.4° over 360° which is 0.94%, for case 2 was 5.3° over 360° which is 1.47% and in dip direction 1.6° over 180° which is 0.89% for both cases. In the field test, out of 32 orientation data, 24 data were in the range of measured values, while the others mostly showed an error of ±1°. Results of the model test and the field test showed acceptable errors considering the variation of measurement by a conventional method.

Objective This study reviews evidence that implicates high glucose (HG) in the pathogenesis of peritoneal fibrosis and proposes mechanisms potentially involved in the HG-induced peritoneal fibrosis that is observed in long-term peritoneal dialysis (PD) patients.Design Selected Western literature is reviewed, examining the effect of HG on rat or human peritoneal mesothelial cell (HPMC) biology with particular reference to extracellular matrix (ECM) gene expression and protein synthesis.Results HG up-regulated the expression of monocyte chemotactic peptide–1 (MCP-1), transforming growth factor beta 1 (TGFβ1), and fibronectin messenger RNAs (mRNAs) and proteins. These HG-induced up-regulations were effectively blocked by the inhibition of protein kinase C (PKC). In addition, cytosolic reactive oxygen species (ROS) rapidly increased in HPMC cultured under HG, and treatment with antioxidant effectively inhibited HG-induced fibronectin protein synthesis by HPMC.Conclusion Continuous exposure of the peritoneal membrane to HG may induce changes in HPMC biology, leading to excessive deposition of ECM and peritoneal injury. HG-induced activation of diacylglycerol PKC (DAG–PKC) plays a major role in up-regulation of MCP-1, TGFβ1, and fibronectin synthesis by HPMC cultured under HG. In addition, ROS, recently recognized as signalling molecules, are rapidly generated in HPMC as a result of increased glucose metabolism and may prove to be an important mediator of HG-induced peritoneal injury.

Objectives To evaluate the influence of initial nutritional status on continuous ambulatory peritoneal dialysis (CAPD) patient survival and to identify factors determining initial nutritional status and patient mortality.Design Prospective single-center study.Setting Kidney Center, Soon Chun Hyang University Hospital.Patients A total of 91 consecutive CAPD patients, who underwent initial nutritional assessment at Soon Chun Hyang University Hospital, Seoul, Korea, between September 1994 and January 1999, was included in this study. All patients were assessed at a mean of 7 days after beginning CAPD (range 3 – 24 days). Forty-eight patients were male, 50 were diabetics, and their mean age was 53.9 years (range 22 – 76 years).Methods Nutritional status was assessed by subjective global assessment (SGA), biochemical and anthropometric measurements, fat-free edema-free (FFEF) body mass by creatinine kinetics, urea kinetic studies, and calculation of the normalized protein equivalent of total nitrogen appearance (nPNA).Results By SGA, 55% were classified as having normal nutrition while 45% had signs of malnutrition; 61% of female and 31% of male patients, and 54% of diabetics and 34% of nondiabetics were classified as malnourished. Initial FFEF body mass, blood urea nitrogen (BUN), serum albumin (sAlb), residual renal function (RRF), and weekly total creatinine clearance were significantly lower in the malnourished patients than in the patients with normal nutrition. On multiple regression analysis, only FFEF body mass was an independent determinant of SGA score. On 31 January 1999, 41 patients were still on CAPD, 15 patients had died, and 27 patients had been transferred to hemodialysis. Those who died during observation were older and had lower initial FFEF body mass, % lean body mass, BUN, sAlb, RRF, and SGA score. The 2-year patient survival rate was significantly lower in the malnourished than in normal patients (67.1% vs 91.7%, p= 0.02). On Cox proportional hazards analysis, initial age, malnutrition assessed by SGA, and FFEF body mass were identified as factors determining death.Conclusion Malnutrition was present in 45% of patients commencing CAPD when assessed by SGA. Initial FFEF body mass was a determinant of SGA score and predicted death. Malnutrition as assessed by SGA was also an independent predictor of death. Initial nutritional status, therefore, appears to exert a powerful influence on CAPD patient survival.

Objective To evaluate the convective transport characteristics of glucose and the effect of high glucose and insulin during experimental peritoneal dialysis in rat.Methods Male Sprague–Dawley rats weighing 300 – 400 g were used in this study. Mannitol (5%) was used as osmotic agent. Glucose was added to dialysis solution to yield a concentration of 100 mg/dL (group 1) or 300 mg/dL (group 2). Mannitol solution (5%) containing the same concentration of electrolytes and lactate but without glucose was used as control (group 3). In group 2, blood sugar was maintained at approximately 300 mg/dL by continuous intravenous infusion of 25% glucose solution and 0.9% NaCl solution. A 2-hour dwell study was performed with 30 mL of test solutions. Intraperitoneal volume was calculated by volume marker (18.5 kBq of 131I-human radioiodinated serum albumin, RISA) dilution with corrections made for the elimination of RISA from the peritoneal cavity (KE) and sample volume. The diffusive mass transport coefficient (KBD) and sieving coefficient (SBRF) were calculated by using the Babb–Randerson–Farrell model. S was also calculated directly by using isocratic methods (SI). The peritoneal fluid absorption rate (KE) was taken into account for the calculation of SI.Results Intraperitoneal volume was significantly higher in group 2 compared with groups 1 and 3. Peritoneal fluid absorption rate, KE, was similar in all three groups. SBRFand SIfor glucose were significantly lower in group 2 compared with groups 1 and 3. SBRFfor glucose in group 2 was below zero and SInear zero. KBDfor glucose was significantly higher in group 2 than in groups 1 and 3. Plasma and dialysate concentrations of insulin increased during the initial hour and then decreased to the baseline value in groups 1 and 3, while in group 2 it continuously increased.Conclusion Significantly lower sieving coefficients for glucose in the high glucose and high insulin group suggest that transport mechanisms other than simple passive transport are involved in peritoneal glucose transport, and that high glucose per seand/or high insulin may be important factors that determine glucose transport characteristics.

Objectives To assess the nutritional status of Korean peritoneal dialysis (PD) patients and to compare with data from Western literature, and to elucidate independent factors determining nutritional status and death.Design Cross-sectional single-center study.Setting Kidney Center, Soon Chun Hyang University Hospital.Materials Ninety-eight CAPD patients were included. Of these, 54 patients were male, 32 patients were diabetic, mean age was 47.9 :i: 13.1 years, and mean duration of CAPD was 22.3 :i: 21.6 months. The patients were followed until death, transfer to hemodialysis (HD) or other units, transplantation, or until 3 years had elapsed after the first evaluation.Methods Nutritional status was assessed by subjective global assessment (SGA), biochemical and anthropometric measurements, fat-free edema-free (FFEF) body mass by creatinine (Cr) kinetics, protein equivalent of total nitrogen appearance (PNA), and urea kinetic studies.Results By SGA score, 53.1% of patients were classified as normal, 44.9% with mild-to-moderate malnutrition, and 2% with severe malnutrition. Patients with malnutrition were significantly older and had higher peritonitis rates, lower serum albumin (Alb), blood urea nitrogen (BUN), serum Cr, FFEF body mass, mid arm muscle circumference, and PNA (p < 0.05). On stepwise multiple regression analysis, the SGA score was negatively correlated with age and peritonitis rate (p < 0.01). At the end of the 3-year follow-up period, 11 patients were still on CAPD, 26 had died, 51 had transferred to HD and 5 to other units, 3 patients had been transplanted, and 2 patients were lost to follow-up. Patients who died during follow-up were older and had higher peritonitis rates and lower total serum protein, Alb, Cr, and FFEF body mass when compared to those who survived (p < 0.05). Independent predictors of death were age, peritonitis rate, and serum Alb (p < 0.01).Conclusion Malnutrition was as common in Korean PD patients as reported in the Western literature. Our data suggests that, to prevent malnutrition and early death, it is important to reduce the peritonitis rate, to improve protein intake, and to prescribe an adequate dose of peritoneal dialysis.

In order to evaluate peritoneal membrane function and responsiveness of peritoneal microcirculation to vasoactive agents in long-term continuous ambulatory peritoneal dialysis (CAPD) patients, we studied peritoneal clearances of urea (Curea) and creatinine (Ccr), protein concentrations in drained dialysate (D PC), peritoneal glucose absorption (% GA), and drained dialysate volume (VD) before and after nitroprusside (NP) addition to dialysis solution in 17 long-term CAPD patients (mean duration of CAPD: 52 months) and the results were compared to those of 18 patients who were just trained for CAPD (mean duration: 0.6 month).There were no differences in the control (without NP) Curea, Ccr, D PC, %GA, and VDbetween the new and long-term CAPD patients. Curea, Ccr, and D PC increased significantly with NP in both new and long-term patients. Curea and Ccr with NP were not different between the new and long-term patients but D PC with NP was significantly lower in the long-term CAPD patients.The results of this study suggest that peritoneal solute clearances and the responsiveness of peritoneal microcirculation to NP remain unchanged after four years of CAPD, despite recurrent episodes of peritonitis.