Antihyperglycemic effect of short-term arginyl-fructose supplementation in subjects with prediabetes and newly diagnosed type 2 diabetes: randomized, double-blinded, placebo-controlled trial

Background

A previous study reported that arginyl-fructose may have great value as a functional food with antioxidant and antidiabetic activities. However, there have been few clinical studies on the efficacy of arginyl-fructose supplementation for blood glucose control.

Methods

In this double-blind, placebo-controlled study, 60 Korean subjects with prediabetes or type 2 diabetes mellitus were randomly assigned to placebo or test groups. The test group subjects received 1500 mg/day arginyl-fructose. Fasting serum levels of glucose, hemoglobin A1c, insulin, and free fatty acids were measured by 2-hour oral glucose tolerance tests at baseline and after the 6-week intervention. Eleven subjects dropped out or were excluded during the trial. The data for the remaining 49 were statistically analyzed using Student’s t-test and paired t-test.

Results

After the 6-week intervention, the test group showed significant reductions in serum glucose levels at 30 minutes (−19.4 ± 5.62 mg/dL) and 60 minutes (−15.4 ± 7.01 mg/dL) and reduced glucose area under the curve (−27.4 ± 8.59 mg/dL) compared with those of the placebo control group. The changes (differences from baseline) in serum glucose levels at 60 minutes and glucose area under the curve in the test group differed significantly from those in the control group even after adjusting for baseline values. In contrast, glucose-related biomarkers including hemoglobin A1c, insulin, and C-peptide levels were not significantly improved by the dietary intervention with arginyl-fructose.

Conclusions

Arginyl-fructose supplementation (1500 mg/day) may be beneficial for reducing postprandial blood glucose levels in patients with prediabetes or type 2 diabetes mellitus.

Trial registration

ClinicalTrials.gov NCT02285231. Registered 11 May 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-015-1036-z) contains supplementary material, which is available to authorized users.

Trophic structure in a pilot system for the integrated multi-trophic aquaculture off the east coast of Korean peninsula as determined by stable isotopes

To assess the potential for nutritional exploitation of caged-fish-derived waste through the use of extractive co-cultured species in a pilot system for an integrated multi-trophic aquaculture (IMTA), we compared their C and N stable isotope ratios with those of uncultured macroinvertebrates in and around the system. Black rockfish were co-cultured with sea cucumber, oyster, and two macroalgae as extractive species. Isotope signatures of the co-cultured sea cucumber at the IMTA site differed from those at the control site, indicating their assimilation of aquaculture wastes. In contrast, δ(13)C and δ(15)N of individual taxa of the cultured oyster and uncultured invertebrates were consistent between sites, suggesting a minor contribution of the aquaculture waste to benthic and pelagic food chains in and around the IMTA system. These results provide evidence of the suitability of using sea cucumber as an extractive species to reduce the impact of a monoculture system on the ambient environment.

The effects of chitosan oligosaccharide (GO2KA1) supplementation on glucose control in subjects with prediabetes

We aimed to evaluate the effect of chitosan oligosaccharide (GO2KA1) supplementation on glucose control in subjects with prediabetes. This study was a randomized, double-blind, placebo-controlled clinical trial. Subjects with prediabetes were randomly assigned to the GO2KA1 intervention group or the placebo group for 12 weeks. We assessed the serum levels of glucose, insulin, and C-peptide by a 2 hour value in the 75 g oral glucose tolerance test (OGTT), HbA1c, pro-inflammatory cytokines, and plasma adiponectin at baseline and after the 12 week intervention. The treatment group showed a significant decrease in the serum glucose level at 30 min (p = 0.013) and at 60 min (p = 0.028). The change of the serum glucose level at 60 min was significant in the treatment group compared with the placebo group (p = 0.030). Also, the plasma level of HbA1c (p = 0.023) and the pro-inflammatory cytokines (IL-6 and TNF-α) were reduced and plasma adiponectin was increased in the GO2KA1 intervention group after the 12 week treatment. However, the placebo group did not show any significant changes in these biomarkers. In subjects with prediabetes, 12 week supplement with GO2KA1 may help control postprandial glucose compared with control.

Korean red ginseng improves glucose control in subjects with impaired fasting glucose, impaired glucose tolerance, or newly diagnosed type 2 diabetes mellitus

This study was designed to evaluate the effect of Korean red ginseng (KRG) supplementation on glucose control in subjects with impaired fasting glucose (IFG), impaired glucose tolerance (IGT), or newly diagnosed type 2 diabetes mellitus (T2DM). The study was a 12-week randomized, double-blinded, placebo-controlled (5 g of KRG [n=21] or placebo [n=20] in tablet form) trial. Glucose-related biomarkers, including serum and whole blood levels of glucose, insulin, and C-peptide, were measured by 2-h oral glucose tolerance tests (OGTTs) at baseline and after the 12-week intervention. After the intervention, the test group showed a significant decrease in serum levels of glucose at 30 min (-22.24±10.77 mg/dL) and whole blood levels of glucose at 30 min (-17.52±5.22 mg/dL). In addition, the test group tended to have lower whole blood levels of glucose at 0 min and glucose area under curve (AUC). However, the placebo group did not show any changes in blood glucose-related indices. The changes (difference from baseline) in serum glucose levels at 30 min, whole blood glucose levels at 60 min, and glucose AUC during OGTTs in the test group exhibited a tendency toward a decrease from those in the placebo group. There were significant decreases or trends toward a decrease in both serum insulin and C-peptide concentrations at most time intervals in the test group. In conclusion, KRG supplementation (5 g/day) may be beneficial for controlling serum and whole blood glucose levels compared with placebo among patients with IFG, IGT, or T2DM.

Physiological disturbance of the Manila clam, Ruditapes philippinarum, by altered environmental conditions in a tidal flat on the west coast of Korea

To examine the influence of habitat alteration by tideflat reclamation on the physiological ecology of Ruditapes philippinarum, seasonal variations in its condition, gross biochemical composition, and reproductive cycle were compared for a yearly cycle between a reclaimed flat (Gomsohang, GS) and a natural flat (Hajun, HJ) in Gomso Bay, Korea. Concentrations of chlorophyll a and seston (as well as its energy value as food available to the clam) were consistently higher at HJ than at GS. Condition, dry tissue weight, and energy reserves (proteins and carbohydrates) of the clams were much higher at HJ than at GS during spring-summer, when fast growth and gametogenic development occur. Furthermore, their spring gametogenic development and spawning were advanced at HJ compared with GS. Our results suggest that the Manila clam encounters nutritionally stressful environmental conditions in altered habitats after tideflat reclamation that lead to lowered nutrient accumulation and a changing reproductive cycle.

The outcome and efficacy of recanalization in patients with acute internal carotid artery occlusion

BACKGROUND AND PURPOSE

Acute occlusion of the ICA is often associated with poor outcomes and severe neurologic deficits. This study was conducted to evaluate outcome of the occluded ICA and efficacy of recanalization under protective flow arrest.

MATERIALS AND METHODS

Fifty consecutive patients who underwent endovascular treatment for acute ICA occlusion were identified from the prospectively collected data base. We assessed NIHSSo, occlusion type (cardioembolism vs atherosclerosis), occlusion level (supraclinoid-terminal, petrocavernous, or bulb-cervical), recanalization degree (TICI), and efficacy of recanalization (protective flow arrest vs nonprotection) leading to better outcome.

RESULTS

Successful recanalization (TICI ≥ 2) was obtained in 90% of patients and good recovery (mRS ≤ 2) in 60% of patients. Good outcome was related to National Institutes of Health Stroke Scale score on admission (P < .001), TICI (P < .007), occlusion type (P = .022), and occlusion level (P = .038). Poor initial patient status, less recanalization, cardioembolism, and supraclinoid-terminal occlusion were associated with poor prognosis. Application of protective flow arrest led to better outcome in the distal ICA segment than in the bulb-cervical segment.

CONCLUSIONS

In addition to the initial patient status and successful recanalization, the occlusion level or type of the occluded ICA could affect clinical outcome. In this study, treatment benefits of protective flow arrest were accentuated in patients with ICA occlusion above the bulb-cervical segment.

Association of polymorphisms in FADS gene with age-related changes in serum phospholipid polyunsaturated fatty acids and oxidative stress markers in middle-aged nonobese men

Background:

To investigate the association of FADS gene polymorphisms with age-related changes in polyunsaturated fatty acids (PUFAs) in serum phospholipids and oxidative stress markers.

Methods:

We genotyped 122 nonobese men aged 35–59 years without any known diseases at baseline for rs174537 near FADS1 (FEN1 rs174537G > T), FADS2 (rs174575, rs2727270), and FADS3 (rs1000778), and followed them for 3 years.

Results:

Among the four single-nucleotide polymorphisms, the minor variants of rs174537 and rs2727270 were significantly associated with lower concentrations of long-chain PUFAs. However, rs174537G > T showed stronger association. At baseline, men with the rs174537T allele had lower arachidonic acid (AA) and AA/linoleic acid (LA), and higher interleukin (IL)-6 levels than rs174537GG counterparts. After 3 years, rs174537GG men had significantly increased AA (P = 0.022), AA/dihomo-γ-linolenic acid (DGLA) (P = 0.007), docosapentaenoic acid (DPA), low-density lipoprotein (LDL) cholesterol, and oxidized LDL (ox-LDL), but decreased eicosatrienoic acid. The rs174537T group showed significantly increased γ-linolenic acid and ox-LDL, and decreased eicosadienoic acid, eicosapentaenoic acid (EPA)/α-linolenic acid (ALA), and IL-6. After 3 years, the rs174537T group had lower AA (P < 0.001), AA/DGLA (P = 0.019), EPA, DPA, EPA/ALA, and urinary 8-epi-prostaglandin F_2α (8-epi-PGF_2α) (P = 0.011) than rs174537GG. Changes in AA (P = 0.001), AA/DGLA (P = 0.017), EPA, DPA, EPA/ALA, and urinary 8-epi-PGF_2α (P < 0.001) were significantly different between the groups after adjusting for baseline values. Overall, changes in AA positively correlated with changes in urinary 8-epi-PGF_2α (r = 0.249, P = 0.007), plasma ox-LDL (r = 0.199, P = 0.045), and serum IL-6 (r = 0.289, P = 0.004).

Conclusion:

Our data show that FADS polymorphisms can affect age-associated changes in serum phospholipid long-chain PUFAs, Δ5-desaturase activity, and oxidative stress in middle-aged nonobese men. In particular, the rs174537T allele did not show the age-associated increases in AA and Δ5-desaturase activity seen with the rs174537GG genotype.

Increased arterial stiffness in subjects with impaired fasting glucose

AIMS

The present study investigated the association between fasting glucose and arterial stiffness in subjects with normal fasting glucose (NFG) and impaired fasting glucose (IFG).

METHODS

The study group consisted of 1043 subjects, including 683 subjects with NFG and 360 subjects with IFG (100≤fasting glucose <126 mg/dL). All subjects were evaluated for glucose, insulin, lipid profiles, high sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), 8-epi-prostaglandin F2α (8-epi-PGF2α) and brachial-ankle pulse wave velocity (ba-PWV).

RESULTS

MDA (P<0.001) and ba-PWV (P<0.001) in the IFG group were higher than those in the NFG group after adjustment for sex, age, BMI, smoking and drinking, waist, blood pressure, serum lipid profiles. Ba-PWV in the IFG group was still higher than that in the NFG group after further adjustment for hs-CRP, MDA, 8-epi-PGF2α (P=0.031). Through multiple linear regression analysis, ba-PWV was found to be independently and positively associated with fasting glucose, age, systolic blood pressure, triglyceride, hs-CRP and insulin and negatively associated with male:female ratio, BMI.

CONCLUSION

Arterial stiffness was higher in the IFG group than in subjects with NFG even after adjustment for all confounding variables including hs-CRP and oxidative stress markers. In addition, fasting glucose and insulin were positively and independently associated with the ba-PWV in non-diabetic healthy adults.

Weight reduction effects of a black soy peptide supplement in overweight and obese subjects: double blind, randomized, controlled study

The present study determined the effect of black soy peptide supplementation on body weight and body fat in overweight/obese subjects. In a double-blind controlled trial, participants (n = 80) were randomized to either soy peptide supplementation (the test group) or to a placebo (the placebo group). Sixty-four people completed the study, and anthropometric parameters, serum inflammatory markers, and leptin and lipid profiles were measured. After 6 weeks, the test group (n = 35) had significant reductions in body weight (p = 0.003) and body mass index (BMI) (p = 0.004), body fat mass (p = 0.038). After 12 weeks, they also had significant reductions in body weight (p < 0.001), BMI (p < 0.001), body fat percentage (p = 0.002), and body fat mass (p = 0.001). However, these significances were not observed in the placebo group (n = 29). In addition, net changes in body weight and body fat mass in the test group were significantly bigger than those in the placebo group after 12 weeks. Leptin levels were significantly reduced in the test groups (p = 0.047), but were not observed in the placebo group (p = 0.323). Interestingly, the subjects with weight reductions ≥1kg in the test group had greater reductions in circulating leptin levels (p = 0.002). Additionally, fasting insulin levels were significantly reduced in the test groups. The conclusion is that black soy peptide supplementation may be beneficial for body weight control in overweight/obese subjects.

Supervised exercise program, BMI, and risk of type 2 diabetes in subjects with normal or impaired fasting glucose

OBJECTIVE

To determine the association of regular exercise, BMI, and fasting glucose with the risk of type 2 diabetes and to predict the risk.

RESEARCH DESIGN AND METHODS

Korean subjects (n = 7,233; 40-79 years old) who were not diagnosed with diabetes at baseline were enrolled through the National Health Insurance Corporation. All participants underwent biennial examinations, and 1,947 of 7,233 subjects also underwent a 6-month program of moderate-intensity exercise (300 min/week) without dietary advice.

RESULTS

During follow-up (mean = 2 years), there were 303 incidents of type 2 diabetes in the nonexercise program group (n = 5,286) and 83 in the exercise program group (n = 1,947). After adjusting for confounders, the risk of type 2 diabetes was positively associated with BMI and inversely with regular exercise, especially among overweight/obese subjects. After further adjustment for BMI, the odds ratios for risk of diabetes associated without and with regular exercise were 1.00 and 0.77, respectively. Among subjects with normal fasting glucose, exercise reduced the diabetes risk; however, among those with impaired fasting glucose (IFG), the protective effect of exercise was found only among overweight/obese subjects. The overweight/obese subjects in the exercise program group exhibited improved fasting glucose compared with the nonexercise program group and showed 1.5 kg of weight loss and a 3-cm decrease in waist circumference. Among overweight/obese subjects with unchanged fasting glucose, weight loss was greater in the exercise program group.

CONCLUSIONS

Regular exercise reduces the risk of type 2 diabetes in overweight/obese individuals. Particularly, regular exercise and weight or waist circumference control are critical factors for preventing diabetes in overweight/obese individuals with IFG.

Beneficial immunostimulatory effect of short-term Chlorella supplementation: enhancement of natural killer cell activity and early inflammatory response (randomized, double-blinded, placebo-controlled trial)

BACKGROUND

In vitro and animal studies have demonstrated that Chlorella is a potent biological response modifier on immunity. However, there were no direct evidences for the effect of Chlorella supplementation on immune/inflammation response in healthy humans.

METHODS

This study was designed for an 8-week randomized, double-blinded, placebo-controlled trial: 5g of Chlorella (n=23) or Placebo (n=28) as form of tablets. Mainly, cytotoxic activities of Natural killer (NK) cells and serum concentrations of interferon-γ, interleukin-1β and interleukin-12 were measured.

RESULTS

After the 8-week, serum concentrations of interferon-γ (p<0.05) and interleukin-1β (p<0.001) significantly increased and that of interleukin-12 (p<0.1) tended to increase in the Chlorella group. The increments of these cytokines after the intervention were significantly bigger in the Chlorella group than those in the placebo group. In addition, NK cell activities (%) were significantly increased in Chlorella group, but not in Placebo group. The increments of NK cell activities (%) were also significantly bigger in the Chlorella group than the placebo group. Additionally, changed levels of NK cell activity were positively correlated with those of serum interleukin-1β (r=0.280, p=0.047) and interferon-γ (r=0.271, p<0.005). Signficantly positive correlations were also observed among the changed levels of serum cytokines; between interferon-γ and interleukin-1β (r=0.448, p<0.001), between interleukin-12 and interleukin-1β (r=0.416, p=0.003) and between interleukin-12 and interferon-γ (r=0.570, p<001).

CONCLUSION

These results may suggest a beneficial immunostimulatory effect of short-term Chlorella supplementation which enhances the NK cell activity and produces interferon-γ and interleukin-12 as well as interleukin-1β, the Th-1 cell-induced cytokines in healthy people.

Anti-influenza virus activity of green tea by-products in vitro and efficacy against influenza virus infection in chickens

Polyphenolic compounds present in green tea, particularly catechins, are known to have strong anti-influenza activity. The goal of this study was to determine whether green tea by-products could function as an alternative to common antivirals in animals compared to original green tea. Inhibition of viral cytopathic effects ascertained by neutral red dye uptake was examined with 50% effective (virus-inhibitory) concentrations (EC₅₀)determined. Against the H1N1 virus A/NWS/33, we found the anti-influenza activity of green tea by-products (EC₅₀ = 6.36 µg/mL) to be equivalent to that of original green tea (EC₅₀= 6.72 µg/mL). The anti-influenza activity of green tea by-products was further examined in mouse and chicken influenza infection models. In mice, oral administration of green tea by-products reduced viral titers in the lungs in the early phase of infection, but they could not protect these animals from disease and death. In contrast, therapeutic administration of green tea by-products via feed or water supplement resulted in a dose-dependent significant antiviral effect in chickens, with a dose of 10 g/kg of feed being the most effective (P < 0.001). We also demonstrated that unidentified hexane-soluble fractions of green tea by-products possessed strong anti-influenza activity, in addition to ethyl acetate-soluble fractions, including catechins. This study revealed green tea by-product extracts to be a promising novel antiviral resource for animals.

Associations of plasma homocysteine level with brachial-ankle pulse wave velocity, LDL atherogenicity, and inflammation profile in healthy men

AIMS

To investigate the association of plasma total homocysteine (tHcy) with arterial stiffness, measured as brachial-ankle pulse wave velocity (baPWV), LDL atherogenicity, and inflammation profile in healthy men.

METHODS AND RESULTS

In this cross-sectional study, 612 healthy men aged 31-79 years were classified into quartiles according to plasma tHcy concentration. In the total study population, tHcy concentration showed positive correlation with age (r=0.083, P=0.040), interleukin (IL)-1β (r=0.249, P<0.001), TNF-α (r=0.150, P<0.001), IL-6 (r=0.154, P<0.001), oxidized LDL (oxLDL) (r=0.161, P=<0.001), and baPWV (r=0.087, P=0.032); and negative correlation with folate (r=-0.353, P<0.001) and vitamin B(12) (r=-0.269, P<0.001). In subgroup analysis based on plasma tHcy level, tHcy was associated with baPWV in men with high levels of tHcy (≥ 13.1μmol/L, n=153; r=0.258, P=0.001), but not in those with low-tHcy (<13.1 μmol/L, n=459; r=-0.033, P=0.478). The association between tHcy and baPWV in the high-tHcy group remained significant after adjustment for age, BMI, smoking, drinking, folate, and vitamin B₁₂. In the high-tHcy group, tHcy level was also positively correlated with IL-1β, TNF-α, oxLDL, and blood pressure; and negatively correlated with LDL particle size. In addition, baPWV showed negative correlation with LDL particle size and positive correlation with oxLDL in the high-tHcy group.

CONCLUSION

This study shows an association between high levels of plasma tHcy and more advanced arterial stiffness, smaller LDL particle size, and higher levels of oxLDL and cytokines in men with hyperhomocysteinemia. Enhanced arterial stiffness in hyperhomocysteinemia might be attributed, in part, to Hcy-related LDL atherogenicity.

FADS gene polymorphisms in Koreans: association with ω6 polyunsaturated fatty acids in serum phospholipids, lipid peroxides, and coronary artery disease

OBJECTIVE

We investigated the association of polymorphisms in FADS genes with polyunsaturated fatty acids (PUFAs) in serum phospholipids, lipid peroxides, and coronary artery disease (CAD) in Koreans.

METHODS

In this case-control study, CAD patients (n=756, 40-79 years) and healthy controls (n=890) were genotyped for rs174537 near FADS1 (FEN1 rs174537G>T), FADS2 (rs174575, rs2727270), and FADS3 (rs1000778). We calculated the odds ratios (ORs) for CAD risk and measured serum PUFA composition and lipid peroxide.

RESULTS

Among four SNPs, only rs174537G>T differed in allele frequencies between controls and CAD patients after adjustment for age, BMI, cigarette smoking, alcohol consumption, hypertension, diabetes mellitus, and hyperlipidemia (P=0.017). The minor T allele was associated with a lower risk of CAD [OR 0.75 (95%CI 0.61-0.92), P=0.006] after adjustment. rs174537T carriers had a significantly higher proportion of linoleic acid (LA, 18:2ω6), lower arachidonic acid (AA, 20:4ω6), and lower ratios of AA/dihomo-γ-linolenic acid (DGLA, 20:3ω6) and AA/LA than G/G subjects in both control and CAD groups. In the control group, 174537T carriers had significantly lower levels of total- and LDL-cholesterol, malondialdehyde, and ox-LDL. In CAD patients, rs174537T carriers showed a larger LDL particle size than G/G subjects. The proportion of AA in serum phospholipids positively correlated with LDL-cholesterol, ox-LDL, and malondialdehyde in controls and with 8-epi-prostaglandin F(2α) in both control and CAD groups.

CONCLUSION

The rs174537T is associated with a lower proportion of AA in serum phospholipids and reduced CAD risk, in association with reduced total- and LDL-cholesterol and lipid peroxides.

Low power consumption and high sensitivity carbon monoxide gas sensor using indium oxide nanowire

In this paper, micro gas sensor was fabricated using indium oxide nanowire for effective gas detection and monitoring system. Indium oxide nanowire was grown using thermal CVD, and their structural properties were examined by the SEM, XRD and TEM. The electric properties for microdropped indium oxide nanowire device were measured, and gas response characteristics were examined for CO gas. Sensors showed high sensitivity and stability for CO gas. And with below 20 mw power consumption, 5 ppm CO could be detected.

Glutamine induces heat-shock protein-70 and glutathione expression and attenuates ischemic damage in rat islets

BACKGROUND

The transplantation of isolated islets is believed to be an attractive approach for cure of diabetes mellitus. Heat-shock protein (HSP70), which plays a vital role in cellular protection, has been detected in various tissues subjected to stress. Glutamine (GLN) is an important cellular fuel and an essential precursor for the antioxidant glutathione (GSH). It is believed to enhance cellular survival against a variety of stressful stimuli through HSP70. Thus, we performed this study to examine the hypothesis that preoperative GLN administration induces HSP70 and GSH expression before islet transplantation attenuating ischemic damage to rat islets.

METHODS

Adult male Sprague-Dawley (SD) rats were randomly divided into two groups according to the administration of GLN after islet isolation. Group A served as the controls, receiving no GLN. Group B islet cells were cultured with L-GLN (10 mmol/L) supplementation for 24 hours. The GSH levels were measured in islet cells. Both HSP70 and proteins related to apoptosis were analyzed in islet cells by Western blots. Isolated rat islets were cultured with interleukin (IL)-1beta. Nitrite production was measured using the Griess reagent.

RESULTS

The GSH levels were significantly elevated in the glutamine-treated group. HSP70 expression in islets treated with GLN was markedly stronger compared with the control group. The basal Bcl-2 expression was markedly increased by GLN treatment. The GLN-treated group showed attenuated IL-1beta-induced injury in association with NO production.

CONCLUSION

These results suggested that preoperative GLN administration induced HSP70 and GSH expressions before islet transplantation, thus attenuating IL-1beta-induced injury in association with NO production and apoptosis, which might be potential tool to mitigate the ischemic damage to islet cells and the early inflammation at the site of implantation through a self-protective mechanism.

Case of adult mumps infection after renal transplantation

Viruses are the most common cause of opportunistic infections, important complications of transplantation. Mumps infection in renal transplant recipients is uncommon. This report focused on a 23-year-old woman who received immunosuppressive therapy based on tacrolimus, prednisolone, and mycophenolate mofetil for renal transplantation. Sixteen months after transplantation, she was admitted with pain and swelling in both infra-auricular areas. Laboratory findings demonstrated positive mumps IgM and IgG antibodies and an increased serum amylase level. Computed tomography revealed both parotid glands to be diffusely enlarged. After the diagnosis of mumps parotitis, the patient's immunosuppression was reduced and the clinical course was satisfactory.

Electrical characterization of ZnO single nanowire device for chemical sensor application

Vertically well-aligned high quality ZnO nanowires were grown on GaN epilayer on c-plane sapphire via a vapor-liquid-solid (VLS) process by introducing an Au thin film (3 nm) as a catalyst. ZnO single nanowire device was ingenuously fabricated by combining conventional optical lithography and high resolution electron beam lithography and its current-voltage characteristics were measured with doing the post process to acquire reproducible performance as a chemical gas sensor. And its temperature dependent current-voltage characteristics were measured to investigate temperature dependant electrical transport. The ZnO nanowire device showed slightly non-ohmic current-voltage characteristics which may be due to back-to-back configuration of the diodes with the insulating contact barriers and showed an relatively small activation energy of 0.2 eV. To test our device as a chemical sensor, the NO2 gas response was reported at the elevated temperature.

Polyoma virus-associated nephropathy and concurrent cytomegalovirus infection in the kidney transplant recipients

INTRODUCTION

Cytomegalovirus (CMV) and polyoma virus BK (BKV) may both establish latency following primary infection. Frequent reactivation of these viruses can occur in the kidney transplant recipients. BKV may induce CMV gene expression by stimulating cellular regulator proteins or by its own gene regulator proteins. A high rate of concurrent CMV infections has been noted in kidney transplant recipients with polyoma virus-associated nephropathy (PVAN).

METHODS

PVAN was identified in 10 of 191 patients who received kidney transplants between October 1998 and September 2003. PVAN was confirmed by allograft kidney biopsy. Four of the 10 patients were complicated by concurrent CMV infection.

RESULTS

Two patients had only serological evidence of CMV infection and one patient had CMV gastritis. These three patients were treated with intravenous ganciclovir with good results. Disseminated ganciclovir-resistant CMV disease was demonstrated in the remaining patient. This 34-year-old kidney transplant recipient with PVAN died of multiorgan failure despite antiviral therapy with both ganciclovir and foscarnet.

CONCLUSION

PVAN with concurrent CMV infection in kidney transplant recipients showed variable clinical courses including mortality. Further studies are needed to elucidate the influence of PVAN on the pathogenesis of CMV infection.

Morphological Evolution of Ba(NO3)2 Supported on α-Al2O3(0001): An In Situ TEM Study

A key question for the BaO-based NOx storage/reduction catalyst system is the morphological evolution of the catalyst particles during the uptake and release of NOx. Notably, because the formed product during NOx uptake, Ba(NO3)2, requires a lattice expansion from BaO, one can anticipate that significant structural rearrangements are possible during the storage/reduction processes. Associated with the small crystallite size of high-surface area gamma-Al2O3, it is difficult to extract structural and morphological features of Ba(NO3)2 supported on gamma-Al2O3 by any direct imaging method, including transmission electron microscopy. In this work, by choosing a model system of Ba(NO3)2 particles supported on single-crystal alpha-Al2O3, we have investigated the structural and morphological features of Ba(NO3)2 as well as the formation of BaO from Ba(NO3)2 during the thermal release of NOx, using ex-situ and in-situ TEM imaging, electron diffraction, energy dispersive spectroscopy (EDS), and Wulff shape construction. We find that Ba(NO3)2 supported on alpha-Al2O3 possesses a platelet morphology, with the interface and facets being invariably the eight [111] planes. Formation of the platelet structure leads to an enlarged interface area between Ba(NO3)2 and alpha-Al2O3, indicating that the interfacial energy is lower than the Ba(NO3)2 surface free energy. In fact, Wulff shape constructions indicate that the interfacial energy is approximately 1/4 of the [111] surface free energy of Ba(NO3)2. The orientation relationship between Ba(NO3)2 and the alpha-Al2O3 is alpha-Al2O3[0001]//Ba(NO3)2[111] and alpha-Al2O3(1-210)//Ba(NO3)2(110). Thus, the results clearly demonstrate dramatic morphology changes in these materials during NOx release processes. Such changes are expected to have significant consequences for the operation of the practical NOx storage/reduction catalyst technology.