Search

Developing a scoring system based on physiological and functional measurements is critical to test the efficacy of potential interventions for sarcopenia and frailty in aging animal models; therefore, the aim of this study was to develop a neuromuscular healthspan scoring system (NMHSS). We examined three ages of male C57BL/6 mice: adults (6–7 months old, 100% survival), old (24–26 months old, 75% survival), and elderly group (>28 months old, ≤50% survival)—as well as mice along this age continuum. Functional performance (as determined by the rotarod and inverted-cling grip test) and in vitro muscle contractility were the determinants. A raw score was derived for each determinant, and the NMHSS was then derived as the sum of the individual determinant scores. In comparison with individual determinants, the NMHSS reduced the effect of individual variability within age groups, thus potentially providing an enhanced ability to detect treatment effects in future studies.

Boron-rich boron nitride (BN) films have been prepared on Si and SiO2/Si substrates by the vacuum pyrolysis of spin-coated polyborazine films. Physical properties of the prepared films such as film strength, thermal conductivity, and dielectrics were determined. The BN films vacuum-pyrolyzed at 900°C showed residual N–H bonds with a 0.75 N/B ratio, interdiffusion phenomena, and preferred orientation at the interfacial zone. Hardness and the elastic modulus of the film increased to 1.6 GPa and 50 GPa by nanoindentation loading. It had a thermal conductivity of 134 W/(m·K) at 296.5 K, and a dielectric constant in the range of 5–7, with tan ∂ between 0.01 and 0.47, depending on the film thickness.

Ferrimagnetic particles of Fe 3 O 4 were nanometrically synthesized by coprecipitation. For the purpose of treating tumors in body, hematoporphyrin was used as a photosensitizer, which was coated onto magnetic particles of Fe 3 O 4 . The coated magnetic particles can be localized around the tumor by magnetic field. The concentration of hematoporphyrin was obtained from the optical density using UV-spectrometer. The thermostability of coated magnetic particles were investigated by DSC.

We demonstrate a very precise cavity-mode control scheme in a 1.55 µm multiple-wavelength vertical-cavity surface-emitting laser (VCSEL) array. For the precise control of the cavity mode, selective wet etchings of InP and InAlGaAs superlattice tuning layers are investigated using HCl/H2O and H3PO4/H2O2/H2O solution systems, respectively. The average calibrated cavity-mode spacing between channels for the fabricated eight-channel full VCSEL array structure is approximately 0.9 nm, which agrees well with the calculated value of 0.8 nm.

We used gas chromatography-mass spectrometry (GC-MS) to analyze total yields and relative composition of the volatile compounds from leaf extracts ofElshoizia cilliata. This species contains 22 compounds. The major constituents of its essential oils are dihydrotagetone (62.7%), s-caryophellene (4.96%), germacrene-d (4.03%), and ±-humulene (1.34%). Compounds in these leaf extracts are remarkably high in dihydrotagetones (40.5 to 81.6%). The total amount of monoterpenoids is 3.17 to 7.03 times greater than that of sesquiterpenoids, and is highly correlated with the level of dihydrotagetone (r = 0.97). Seasonal variations are significantly different only for dihydrotagetone (p < 0.0005), but not for the yields of other volatile compounds.

The nanometric particles possess some physical and chemical properties different from the bulk. The water-based magnetic fluids with nanometric CuxFe1−xOFe2O3 particles were prepared by the two-step method, in which the x value varied from 0.1 to 0.4. The experiment results showed the magnetization decreased with increasing x values. The copper element was partly coprecipitated with iron oxides. These phenomena are ascribed to excess ammonia water in the precipitation. The decanoic acid and the nonanoic acid were selected as the first and second surfactants. The optimal reaction temperatures for the first and second surfactants were 80 and 60 °C respectively with the holding time of 30 min.

We propose a new type of 1550 nm vertical-cavity surface-emitting laser incorporating proton implantation and a tunneling junction. The structure relies on a stable material and well-established processing techniques. The fabricated laser operates under pulsed conditions emitting at 1575 nm.

We demonstrate an electrically pumped all-monolithic 1.55-µm multiple-wavelength vertical-cavity surface-emitting laser array with the channel spacing of 1.2 nm. Binary-coded 3-step selective wet etching of InAlGaAs/InP intra-cavity superlattice is used for the precise wavelength adjustment prior to the growth of top distributed Bragg reflector. All the devices in the array show threshold currents between 2.0 and 2.5 mA under 10-%-duty pulse operation at room temperature.

Background To compare the effects of endovascular coiling and neurosurgical clipping in patients with unruptured intracranial aneurysm. Methods Sixteen electronic databases were searched for articles published between 1950 and July 2010 to compare clinical outcomes of clipping and coiling. Researchers reviewed all searched articles and extracted data independently. The quality of studies and evidence were evaluated using MINORS and GRADEprofiler, respectively. The odds ratio (OR) was calculated using the inverse variance meta-analysis method for each study outcome. To assess heterogeneity of ORs across cohorts, Cochran’s Q statistic and I2 were used. Results Of 4160 studies, 24 were identified (n = 31865). Clipping resulted in significantly higher disability using the Glasgow Outcome Scale (OR, 2.38; 95% CI, 1.33–4.26) and Modified Rankin Scale (OR, 2.83; 95% CI, 1.42–5.63) when compared with coiling. ORs for complications were also higher with clipping (ORs for neurological and cardiac complications were 1.94 with a 95% confidence interval [CI] of 1.09–3.47 and 2.51 with a 95% CI of 1.15–5.50). Clipping resulted in significantly greater disability in the short term (≤6 m)(OR on the Glasgow Outcome Scale, 2.72; 95% CI, 1.16–6.34), but not in the long term (>6 m)(OR for Glasgow Outcome Scale, 2.12; 95% CI, 0.93–4.84). Conclusions Coiling was a better procedure for treatment of unruptured intracranial aneurysm in terms of disability, complications, especially in the short term. Because of the limitations of the reviewed studies, further studies are required to support the present results.

Duchenne muscular dystrophy (DMD) is a degenerative skeletal muscle disease that makes walking and breathing difficult. DMD is caused by an X-linked (Xp21) mutation in the dystrophin gene. Dystrophin is a scaffolding protein located in the sarcolemmal cytoskeleton, important in maintaining structural integrity and regulating muscle cell (muscle fiber) growth and repair. Dystrophin deficiency in mouse models (e.g., mdx mouse) destabilizes the interface between muscle fibers and the extracellular matrix, resulting in profound damage, inflammation, and weakness in diaphragm and limb muscles. While the link between dystrophin deficiency with inflammation and pathology is multi-factorial, elevated oxidative stress has been proposed as a central mediator. Unfortunately, the use of non-specific antioxidant scavengers in mouse and human studies has led to inconsistent results, obscuring our understanding of the importance of redox signaling in pathology of muscular dystrophy. However, recent studies with more mechanistic approaches in mdx mice suggest that NAD(P)H oxidase and nuclear factor-kappaB are important in amplifying dystrophin-deficient muscle pathology. Therefore, more targeted antioxidant therapeutics may ameliorate damage and weakness in human population, thus promoting better muscle function and quality of life. This review will focus upon the pathobiology of dystrophin deficiency in diaphragm and limb muscle primarily in mouse models, with a rationale for development of targeted therapeutic antioxidants in DMD patients.

Because the peak age for incidence of sudden deaths in infancy temporally coincides with the age of infant primary immunization, some have raised the question as to whether immunization is a risk factor for sudden death in infancy. Recent occurrence of two sudden deaths in infants in Korea has renewed concerns about the causal association between immunization and sudden deaths in infants.We carried out a retrospective review of data from the Korea Centers for Disease Control and Prevention Adverse Events Following Immunization Surveillance System and Vaccine Compensation programs.From 1994 to 2011, a total of 45 cases of sudden deaths in the first 2 years of life following immunization were reported in Korea. The causes of death were classified as follows: infectious diseases (n= 13); accidental injuries (n= 7); congenital abnormalities (n= 2); and malignancy (n= 1). Of 20 sudden deaths in infancy, nine deaths met Brighton Collaboration case definition level I and II, and therefore were classified as possible sudden infant death syndrome cases. Hepatitis B vaccine (n= 13) was the most frequent vaccine with temporal association with sudden deaths in the first 2 years of life.Few sudden deaths in the first 2 years of life following immunization have been reported, despite the use of universal immunization in Korea. The majority of deaths in infancy did not meet case definition for sudden infant death syndrome. Encouraging investigators to perform thorough investigation, including postmortem autopsy and death scene examination, may promote data comparability and provide guidance on decision-making in the vaccine-safety monitoring and response system in Korea.

The authors investigated the rupture rate among patients with untreated unruptured intracranial aneurysms (UIAs) in South Korea during 2006-2009.A longitudinal study using national representative health-claim data, including all hospital records for every Korean citizen, was used. Patients with a UIA who were 18-80 years old in 2006 were identified using the I67.1 ICD-10 code. To select eligible patients, a historical period of 1 year prior to the first diagnosis of a UIA in 2006 was utilized. Patients with a previous UIA diagnosis, subarachnoid hemorrhage (SAH), or treatments, such as clipping or coiling, during the historical period were excluded from analysis. Patients with head trauma or a brain tumor during the historical period were also excluded. Eligible patients were followed up for at least 3 years from the index date. Rupture was defined as SAH events with at least 14 days of hospitalization, using the I60 ICD-10 code and excluding the I60.8 code, or death within 14 days of hospitalization.Seven thousand four hundred four patients with UIAs were identified, including 1441 treated patients (20%) and 5963 untreated patients (80%), with a median follow-up of 3.3 years. Rupture events occurred in 163 (0.9 cases/100 person-years) of the 5963 untreated patients. The rupture rate was highest in the 1st year after UIA diagnosis. An older age was a risk factor for rupture among patients with UIAs.The overview of the incidence of rupture indicates the need for a preventive strategy and future studies to prevent rupture in Asian patients with UIAs.

Crystalline bismuth silicate films were grown on a Si substrate by metalorganic chemical vapor deposition. A 100 nm SiO2 layer on Si was changed to bismuth silicate film by the reaction with a Bi and O2 gas mixture. A deposition of less than 30 min formed a single‐crystalline phase, having a certain crystallographic relation with (100)Si substrate. The capacitance of the specimen has increased fivefold over that of the original specimen. The crystallinity of deposited films was increased markedly by heat treatment. At the same time, the capacitance of the specimen increased. However, the oxidation of the Si substrate and the formation of a Bi‐rich surface caused a drastic decrease in the capacitance of the specimen.

Aging is characterized by a progressive loss of muscle mass and impaired contractility (e.g., decline in force, velocity, and power). Although the slowing of contraction speed in aging muscle is well described, the underlying molecular mechanisms responsible for the decrement in speed are unknown. Myosin heavy chain (MHC) isoforms are the primary molecules determining contractile velocity; however, the contraction speed of single fibers within a given MHC isoform type is variable. Recent evidence proposes that the decline in shortening velocity (Vo) with aging is associated with a decrease in the relative content of essential myosin light chain 3f (MLC(3f) ) isoform. In the current study, we first evaluated the relative content of MLC(3f) isoform and Vo in adult and old rats. We then used recombinant adenovirus (rAd) gene transfer technology to increase MLC(3f) protein content in the MHC type II semimembranosus muscle (SM). We hypothesized that (i) aging would decrease the relative MLC(3f) content and Vo in type II fibers, and (ii) increasing the MLC(3f) content would restore the age-induced decline in Vo. We found that there was an age-related decrement in relative MLC(3f) content and Vo in MHC type II fibers. Increasing MLC(3f) content, as indicated by greater % MLC(3f) and MLC(3f) /MLC(2f) ratio, provided significant protection against age-induced decline in Vo without influencing fiber diameter, force generation, MHC isoform distribution, or causing cellular damage. To the best of our knowledge, these are the first data to demonstrate positive effects of MLC(3f) against slowing of contractile function in aged skeletal muscle.

The purpose of this study was to examine the risk factors for suicidal ideation and suicide attempts among Korean older adults and to provide evidence for nursing intervention with respect to health-related quality of life (HRQoL). Data from adults 60 and older obtained through the Fourth Korean National Health and Nutrition Examination Survey ( 2007–2009 ) were used. Self-report questionnaires assessed suicidal ideation, suicide attempts, and EuroQoL 5D (EQ-5D) scores. Survey logistic regression was used to reflect the complex survey design. Among the sample of 4,506 individuals, 27.3% had thought about and 1.7% had attempted suicide. Older adults with EQ-5D index scores

LAWLER, J. M., H.-B. KWAK, J.-H. KIM, Y. LEE, J. M. HORD, and D. A. MARTINEZ. Biphasic Stress Response in the Soleus during Reloading after Hind Limb Unloading. Med. Sci. Sports Exerc., Vol. 44, No. 4, pp. 600–609, 2012. Introduction: Extreme disuse and spaceflight elicit rapid skeletal muscle atrophy, accompanied by elevated proinflammatory signaling and impaired stress response proteins (e.g., heat shock proteins (HSP), insulin-like growth factor 1 (IGF-1)). Recovery of muscle mass is delayed during the early stage of reloading after prolonged unloading, with a concomitant impairment of HSP70 and IGF-1. We postulated that proinflammatory signaling and stress response alterations would characterize early and late phases of signaling during reloading. Methods: Twenty-four adult SD rats were divided into the following groups: controls, 28 d of hind limb unloading (HU), HU + early (7 d) reloading (HU-R7), and HU + late (28 d) reloading (HU-R28). Results: Soleus mass decreased (j55%) with HU and remained depressed (j41%) at HU-R7. Nuclear factor JB activation and oxidative stress were elevated with HU and remained high during reloading. HU elevated inducible nitric oxide synthase and returned to baseline during reloading, whereas 3-nitrotyrosine did not increase with HU and peaked at HU-R7. HU depressed levels of HSP25 phosphorylation at Ser82 and IGF-1. Although p-HSP25 and Akt phosphorylation (Ser473) recovered during early reloading, HSP70, heat shock factor 1, and IGF-1 remained depressed. HSP70, heat shock factor 1, and IGF-1 recovered, whereas p-Akt and 3-nitrotyrosine decreased to control levels at HU-R28. Conclusions: Reloading elicited an early phase characterized by elevated nuclear factor JB activation, 3-nitrotyrosine, p-HSP25, and p-Akt levels and a delayed phase with recovery of HSP70, IGF-1, and muscle mass. We conclude that the reloading phenotype in skeletal muscle is expressed in two distinct phases related to

Summary Background Japanese encephalitis (JE) was the leading cause of viral encephalitis among children in South Korea in the 20 th century. This study summarizes recent changes in the epidemiology of JE following the implementation of a vigorous immunization program in the country. Methods Epidemiological investigations were performed for all reported laboratory-confirmed JE cases, and the cumulative incidence was calculated for the surveillance years 2007–2010. Results During the surveillance period, 45 cases of JE were confirmed in the country, resulting in a cumulative incidence of 0.013–0.055 cases per 100 000 population. The median age of cases was 49.4 years, and by age group, 44.4% were aged 40–49 years. Just under a quarter (22.2%) of the cases were found to live close to a pigsty, while 42.2% of the cases were found to reside in the metropolitan areas of Seoul, Incheon, and Gyeonggi-do. None of the cases had a history of vaccination. Conclusions Although JE has traditionally been regarded as a children's disease, the majority of cases now occur in adults in countries where strong immunization programs exist, such as in South Korea. Consideration should be given to an adult vaccination policy in the near future.

Duchenne muscular dystrophy (DMD) is a common and devastating type of childhood-onset muscular dystrophy, attributed to an X-linked defect in the gene that encodes dystrophin. Myopathy with DMD is most pronounced in the diaphragm muscle and fast-twitch limb muscles and is dependent upon susceptibility to damage, inflammatory cell infiltration, and proinflammatory signaling (nuclear factor-κB; NF-κB). Although recent papers have reawakened the notion that oxidative stress links inflammatory signaling with pathology in DMD in limb muscle, the importance of redox mechanisms had been clouded by inconsistent results from indirect scavenger approaches, including in the diaphragm muscle. Therefore, we used a novel catalytic mimetic of superoxide dismutase and catalase (EUK-134) as a direct scavenger of oxidative stress in myopathy in the diaphragm of the mdx mouse model. EUK-134 reduced 4-hydroxynonenal and total hydroperoxides, markers of oxidative stress in the mdx diaphragm. EUK-134 also attenuated positive staining of macrophages and T-cells as well as activation of NF-κB and p65 protein abundance. Moreover, EUK-134 ameliorated markers of muscle damage including internalized nuclei, variability of cross-sectional area, and type IIc fibers. Finally, impairment of contractile force was partially rescued by EUK-134 in the diaphragm of mdx mice. We conclude that oxidative stress amplifies DMD pathology in the diaphragm muscle.

An enzyme-magnetic nanoparticle conjugate is prepared via conjugation of Ni(2+) ions onto the surface of magnetic nanoparticles to interact with a six histidine-tagged enzyme. The catalytic properties and enzyme rigidification of the conjugates are more stable at high concentrations of aromatic hydrocarbons.

Fibrosis in the aging heart impedes diastolic filling and increases arrhythmias. Previously, we demonstrated that exercise training (ET) reduced collagen I fibrosis and oxidative stress in the agin...

Aging impairs function in the nonischemic heart and is associated with mechanical remodeling. This process includes accumulation of collagen (i.e., fibrosis) and dysregulation of active matrix metalloproteinases (MMPs). Exercise training (ET) improves cardiac function, but the pathways of protection remain poorly understood. Young (3 mo) and old (31 mo) FBNF1 rats were assigned into sedentary and exercise groups, with ET group rats training on a treadmill 45 min/d, 5 d/wk for 12 wk. Nonlinear optical microscopy (NLOM), histology, immunohistochemistry (IHC), and Western blot analyses were performed on the left ventricle and septum. NLOM, IHC, and histological imaging revealed that ET reduced age-associated elevation of collagen type I fibers. Active MMP-1, active MMP-2, and MMP-14 in the ECM fraction of the left ventricle were reduced by aging, an effect abrogated by ET. Tissue inhibitor of MMP (TIMP-1) was elevated with age but protected by ET. Transforming growth factor-β (TGF-β), upstream regulator of TIMP-1, increased with age but was attenuated by ET. Therefore, exercise training could protect the aging heart against dysregulation of MMPs and fibrosis by suppressing elevation of TIMP-1 and TGF-β.—Kwak, H.-B., Kim, J.-H., Joshi, K., Yeh, A., Martinez, D. A., Lawler, J. M. Exercise training reduces fibrosis and matrix metalloproteinase dysregulation in the aging rat heart.

Biomimetic apatite coatings on chemically modified titanium powder have been processed and the resulting coating layers evaluated in terms of morphology, composition and structure, using TF-XRD, XPS, SEM, TEM and FTIR analysis. After 7 days immersion in a simulated body fluid (SBF), nanometer-sized fine precipitates with an amorphous whisker-like phase and a Ca/P atomic ratio of 1.94 were obtained on the external surface of the titanium particles. When the immersion time in SBF was extended to 16 days, the coating layer consisted of the whisker-like nanostructured crystals of carbonated hydroxyapatite with a atomic ratio of 3; in such a case, a double coating layer was developed. The double layer could be divided into two regions and could be clearly distinguished: an inner dense region (approximately 200 nm in thickness) which may include hard agglomerated crystals and an outer less dense region (500 nm in thickness) in which crystals are loosely distributed.

The anode-supported tubular solid oxide fuel cells were fabricated and joined onto the metal cap (SUS430) for current collecting and sealing by using the induction brazing process. Among five filler materials used in the induction brazing, Ni-based BNi2 has shown the lowest gas permeability of 1×10−6 l cm−2 s−1 at a differential pressure of 3 atm measured with He gas. The electrical conductivity of anode support brazed with BNi2 showed 450 S cm−1 at 750°C and stable value even at the long-term and thermal cycle tests. The brazed anode-supported tubular cell at operating temperature of 750°C produced 210 mW/cm2 at 0.7 V. The gas-tightness was confirmed by open circuit voltage (OCV) value similar to theoretical value. The cell showed a stable performance and OCV for 200 h.

The chemical compositions, and antibacterial and antifungal effects of essential oils extracted from three coniferous species, Pinus densiflora, Cryptomeria japonica, and Chamaecyparis obtusa, were investigated. Gas chromatography mass analysis of the essential oils revealed that the major components and the percentage of each essential oil were 16.66% beta-phellandrene and 14.85% alpha-pinene in P. densiflora; 31.45% kaur-16-ene and 11.06% sabinene in C. japonica; and 18.75% bicyclo [2, 2, 1] heptan-2-ol and 17.41% 2-carene in Ch. obtusa. The antimicrobial assay by agar disc diffusion method showed that 2.2 microg of Ch. obtusa oil inhibited most effectively the growth of Escherichia coli ATCC 33312 and Klebsiella oxytoca ATCC 10031, whereas the C. japonica oil gave weak antimicrobial activity. The minimal inhibitory concentration (MIC) values for bacterial strains were in the range of 5.45-21.8 mg/ml depending on essential oils, but most Gram-negative bacteria were resistant even at 21.8 mg oil/ml. P. densiflora oil showed the most effective antifungal activity and the MIC values for Cryptococcus neoformans B42419 and Candida glabrata YFCC 062CCM 11658 were as low as 0.545 and 2.18 mg/ml, respectively. Cryp. neoformans B42419 was the most sensitive to all essential oils in the range of 0.545-2.18 mg/ml. Our data clearly showed that the essential oils from the three conifers had effective antimicrobial activity, especially against fungi.

The effects of exercise training on the nitric oxide synthase (NOS) isoform profile in aging fast-twitch (white gastrocnemius [WG]) and slow-twitch (soleus [SOL]) muscle have not been investigated. Six-month and 27-month male Fischer-344 rats were divided into the following groups: young sedentary (YS), young treadmill exercise trained for 12 weeks, old sedentary (OS), and old exercise trained (OE). Inducible NOS (iNOS) protein expression and activity were significantly higher in OS compared with YS, whereas exercise training significantly reduced iNOS protein and activity levels in the WG. Neuronal NOS protein expression decreased with aging in WG but was upregulated significantly with exercise training in OE for both WG and SOL. Endothelial NOS (eNOS) protein levels were depressed in WG of old rats but were higher in OE than in OS. eNOS was unaffected by aging or exercise in the SOL. Our results indicate that endurance exercise training attenuates age-induced alterations of NOS isoforms with a greater response in fast-twitch compared with slow-twitch muscle.

Previously our laboratory demonstrated that exercise training (ET) attenuated age-induced muscle fiber atrophy, caspase-3 cleavage, and pro-apoptotic Bcl-2 signaling in the rat white gastrocnemius....

Site investigation is used to determine soil types and engineering properties at a site of interest through in situ and laboratory tests. Due to limitations in the opportunities for site visits, safety issues, and time constraints, most introductory geotechnical courses focus on describing the characteristics of individual in situ and laboratory tests. Students usually do not have the opportunity to plan and perform a comprehensive site investigation program, and they are often given existing soil borings and data for use in subsequent design exercises. To overcome these limitations, we are developing a geotechnical site investigation simulation program that includes a variety of in situ and laboratory tests to allow students to conduct their own site investigations. Spatial variability in soil properties is modeled via correlated random fields and Kriging to yield realistic geotechnical data. Via the simulation, students are able to obtain experience and judgment in an essential component of geotechnical engineering practice.

The sgtR1 and sgtR2 genes encoding putative regulators similar to the Aha1 and ArsR families, respectively, were identified downstream from the sprT gene. To investigate their function, expression vectors containing various combinations of sprT, sgtR1, and sgtR2 were transformed into Streptomyces lividans and Streptomyces griseus. The trypsin activity levels produced by S. lividans harboring pWHM3-TR2 (sprT and sgtR2) or pWHM3-TR1R2 (sprT, sgtR2, and sgtR2) were, respectively, 6.6 or 8.9 times that of S. lividans transformed with pWHM3-T (sprT). In the pWHM3-TR1R2 transformant, the transcription of sprT consistently occurred during the earlier stages of growth and was maintained at a higher level throughout the 6 days of cultivation. Streptomyces griseus IFO13350 harboring pWHM3-TR1R2 also produced trypsin activity 2.1 times that of the pWHM3-T transformant. However, all S. griseus Delta adpA transformants produced lower SGT activity than the wild-type strain, and none could overcome the deficiency in AdpA transcriptional activator, suggesting that AdpA is an absolute prerequisite for sprT expression. The sprT transcript was detected at a high level only in the wild-type strain, but the sgtR1 and sgtR2 transcript levels were very similar between the S. griseus IFO13350 and Delta adpA strains. This clearly demonstrates that the transcription of the sgtR1 and sgtR2 genes is not dependent on AdpA and that they are therefore not members of the AdpA regulon.

Bipolar plate and current collector are important stainless steel components of the molten carbonate fuel cell (MCFC) because they supply the pathway of the electron flow between each unit cell. However, these stainless steel components are prone to corrosion in the hot corrosion environment and corrosion products forming on the surface increase the ohmic resistance. In addition, hot corrosion reduces the mechanical strength of the current collector, accelerates electrolyte loss, and finally leads to degradation in cell performance. Therefore, corrosion of stainless steel components is one of the main problems in MCFC systems. To solve these problems, various methods have been studied, such as addition of alloy elements, surface coatings and replacement with higher grade materials. Corrosion resistance of stainless steels is evaluated by potentiodynamic polarization test and weight loss measurements. Electrical conductivity of specimens is measured in molten carbonate at 650 oC. Results from electrochemical tests show that high Cr content causes the formation of a dense and thin oxide layer, subsequently improving the corrosion resistance. However, high Cr content gives rise to inner oxide penetration. Mn enrichment occurs in the oxide layer and may lead to an increase in electrical conductivity. In addition, minor elements such as Si, Nb and N may contribute to the improvement of corrosion resistance and electrical conductivity.

We report InAlGaAs VCSELs with Al2O3 embedded apertures. Using atomic layer deposition, the current confinement apertures are fabricated by depositing of Al2O 3 on air-gap surfaces of undercut apertures, 1.57mum VCSELs showing the output power of over 1 mW and direct modulation at 4 Gbit/s are reported using these apertures