Oral health behaviors and bone mineral density in South Korea: the 2008-2010 Korean National Health and Nutrition Examination Survey.

The purpose of this study was to examine the association between oral health behaviors and bone mineral density (BMD) by using data from the Korean National Health and Nutrition Examination Survey conducted in 2008-2010. We included 6,620 subjects (3,140 men aged more than 50 years and 3,480 postmenopausal women). BMD was measured at three sites-namely, the lumbar spine, total femur, and femur neck. Oral health behaviors were assessed by use of a self-administered questionnaire in the Korean National Health and Nutrition Examination Survey. After adjustment for all covariates, BMD of the lumbar spine and femur neck tended to increase as the frequency of tooth brushing increased in men (p trend = 0.020 and p trend = 0.028, respectively). Women using secondary oral products had increased lumbar spine BMD compared with women who did not use secondary oral products. However, after adjustment for all covariates, no significant relationship was observed between BMD and the use of secondary oral products. As the frequency of tooth brushing and the number of secondary oral products used increased, the prevalence of osteoporosis decreased. The frequency of tooth brushing is associated with increased lumbar spine and femur neck BMD in South Korean men.

Development of semi-empirical soot emission model for a CI engine.

Soot is one of the main harmful emissions of diesel engines that is mainly generated in the reacting fuel jet of diesel injection. Over 99% of the engine-out soot can be filtered by a diesel particulate filter (DPF). However, when the soot load of the DPF is high, a regeneration process that oxidizes the accumulated soot reduces fuel economy. A real-time soot estimation model can contribute to real-time feedback soot control under transient conditions to minimize the engine-out soot emission and frequency of DPF regeneration. A zero-dimensional engine-out soot estimation model for a diesel engine is developed in this study. The semi-empirical soot model considers both the formation and oxidation of soot. In the model, soot formation was correlated with the cross-sectional average equivalence ratio at the lift-off length of the fuel spray. The equivalence ratio at the lift-off length is an indicator of how much air and vaporized fuel are mixed as the fuel reaches the reaction zone. The mass of the injected fuel and combustion duration were also correlated with soot formation. The Nagle and Strickland-Constable mechanism, which calculates the soot oxidation rate was correlated with the soot oxidation in this study. The results of the soot estimation showed an R2 of 0.901 and root mean square error of 10.8 mg/m3 for steady-state experimental cases. The engine-out soot model was also combined with the in-cylinder pressure model proposed by the authors, and validated through the transient Worldwide Harmonized Light Vehicles Test Cycle (WLTC) mode. The estimates agreed with the measured soot, with an accumulated soot error of approximately 6% during the WLTC, even without using an in-cylinder pressure sensor. The soot model developed in this study can help minimize tailpipe-out soot emissions and improve fuel economy by influencing the real-time feedback control during transient and frequent DPF regeneration.

Enhanced production of nonanedioic acid from nonanoic acid by engineered Escherichia coli.

In this study, whole-cell biotransformation was conducted to produce nonanedioic acid from nonanoic acid by expressing the alkane hydroxylating system (AlkBGT) from Pseudomonas putida GPo1 in Escherichia coli. Following adaptive laboratory evolution, an efficient E. coli mutant strain, designated as MRE, was successfully obtained, demonstrating the fastest growth (27-fold higher) on nonanoic acid as the sole carbon source compared to the wild-type strain. Additionally, the MRE strain was engineered to block nonanoic acid degradation by deleting fadE. The resulting strain exhibited a 12.8-fold increase in nonanedioic acid production compared to the wild-type strain. Six mutations in acrR, Pcrp , dppA, PfadD , e14, and yeaR were identified in the mutant MRE strain, which was characterized using genomic modifications and RNA-sequencing. The acquired mutations were found to be beneficial for rapid growth and nonanedioic acid production.

Combinatorial Metabolic Engineering Strategies for the Enhanced Production of Free Fatty Acids in Escherichia coli.

In this study, we evaluated the effects of several metabolic engineering strategies in a systematic and combinatorial manner to enhance the free fatty acid (FFA) production in Escherichia coli. The strategies included (i) overexpression of mutant thioesterase I ('TesAR64C) to efficiently release the FFAs from fatty acyl-ACP; (ii) coexpression of global regulatory protein FadR; (iii) heterologous expression of methylmalonyl-CoA carboxyltransferase and phosphoenolpyruvate carboxylase to synthesize fatty acid precursor molecule malonyl-CoA; and (iv) disruption of genes associated with membrane proteins (GusC, MdlA, and EnvR) to improve the cellular state and export the FFAs outside the cell. The synergistic effects of these genetic modifications in strain SBF50 yielded 7.2 ± 0.11 g/L FFAs at the shake flask level. In fed-batch cultivation under nitrogen-limiting conditions, strain SBF50 produced 33.6 ± 0.02 g/L FFAs with a productivity of 0.7 g/L/h from glucose, which is the maximum titer reported in E. coli to date. Combinatorial metabolic engineering approaches can prove to be highly useful for the large-scale production of FA-derived chemicals and fuels.

Characteristics of NOx emission of light-duty diesel vehicle with LNT and SCR system by season and RDE phase.

As the regulations on vehicle emissions have become more stringent internationally and real-driving emissions (RDE) have been established, the on-road characteristics of emissions have gained importance in vehicle research and development. The results of the fuel consumption levels and emissions from on-road tests are affected by many factors, such as driving conditions, routes and environmental conditions. Therefore, more research and analysis are needed for the effects of environmental factors and driving conditions according to RDE phase on the NOx emissions. In this study, RDE tests were conducted by season to analyze the on-road NOx emission characteristics of lean NOx trap (LNT)- and selective catalytic reduction (SCR)-equipped diesel vehicles corresponding to the Euro 6b regulation prior to the application of the RDE regulation. The purpose of this study is to analyze the effects of seasonal factors and phases of the RDE routes on the NOx emission and NOx conversion efficiency of catalyst. In spring/autumn and summer, the engine-out and tail-pipe NOx emissions were higher 1.3-5.9 times for vehicle A and 1.3-28.4 times for vehicle B in the urban phase than in other phases. In the urban phase, the engine bay temperature was probable to rise owing to frequent stops and low-speed driving, leading to a high intake air temperature, which causes excessive NOx emission, particularly in summer. The average air filter temperature in urban phase was 11-15 °C higher than the environment temperature for vehicle A. The NOx conversion efficiency of the LNT was highest at 54.1% on motorway and the efficiency was dependent on the phase of the test route. The NOx conversion efficiency of the SCR, which is dependent on the catalyst temperature, was highest at 98.7% in spring motorway and the efficiency was affected by the combined factors of season and phases.

The bZIP transcription factor OsABF1 is an ABA responsive element binding factor that enhances abiotic stress signaling in rice.

A number of basic leucine zipper (bZIP) transcription factors are known to function in stress signaling in plants but few have thus far been functionally characterized in rice. In our current study in rice, we have newly isolated and characterized the OsABF1 (Oryza sativa ABA responsive element binding factor 1) gene that encodes a bZIP transcription factor. Its expression in seedling shoots and roots was found to be induced by various abiotic stress treatments such as anoxia, salinity, drought, oxidative stress, cold and abscisic acid (ABA). Subcellular localization analysis in maize protoplasts using GFP fusion vectors indicated that OsABF1 is a nuclear protein. In a yeast experiment, OsABF1 was shown to bind to ABA responsive elements (ABREs) and its N-terminal region was necessary to transactivate the downstream reporter gene. The homozygous T-DNA insertional mutants Osabf1-1 and Osabf1-2 were more sensitive in response to drought and salinity treatments than wild type plants. Furthermore, the upregulated expression of some ABA/stress-regulated genes in response to ABA treatment was suppressed in these Osabf1 mutants. Our current results thus suggest that OsABF1 is involved in abiotic stress responses and ABA signaling in rice.

Test bed for rotation-based triboelectric nanogenerators.

The triboelectric nanogenerator (TENG) has been attracting attention for electronic devices and sensors consuming low power. Among the few operating modes of the TENG, the rotation-based TENG provides a more continuous and smoother output than the linear-motion-based TENG. To evaluate the output performance of the rotation-based TENG precisely and quantitatively, a test bed that adjusts the eccentricity error, tilt angle error, contact force, and rotational speed is proposed. The test bed includes a motor, torque sensor, 2-axis planar stage, 2-axis tilting stage, 1-axis vertical stage, 3-degree-of-freedom force/torque (3-DOF F/T) sensor, and voice coil actuator. With the proposed test bed, the effects of the eccentricity error, tilt angle error, contact force, and rotational speed on the electrical output performance of the rotation-based TENG are analyzed. The test bed is expected to be used for quantitative performance analysis and comparative study of various rotation-based TENGs, and it can help improve the performance and reliability of rotation-based TENGs.

High-Throughput Screening of Acyl-CoA Thioesterase I Mutants Using a Fluid Array Platform.

Screening target microorganisms from a mutated recombinant library plays a crucial role in advancing synthetic biology and metabolic engineering. However, conventional screening tools have several limitations regarding throughput, cost, and labor. Here, we used the fluid array platform to conduct high-throughput screening (HTS) that identified Escherichia coli 'TesA thioesterase mutants producing elevated yields of free fatty acids (FFAs) from a large (106) mutant library. A growth-based screening method using a TetA-RFP fusion sensing mechanism and a reporter-based screening method using high-level FFA producing mutants were employed to identify these mutants via HTS. The platform was able to cover >95% of the mutation library, and it screened target cells from many arrays of the fluid array platform so that a post-analysis could be conducted by gas chromatography. The 'TesA mutation of each isolated mutant showing improved FFA production in E. coli was characterized, and its enhanced FFA production capability was confirmed.

Cost-benefit analysis of water source improvements through borehole drilling or rehabilitation: an empirical study based on a cluster randomized controlled trial in the Volta Region, Ghana.

BACKGROUND: Despite remarkable progress in water coverage improvements, diseases associated with poor water remain a considerable public health problem in many developing countries. OBJECTIVE: We aimed to estimate the costs and benefits of drilling or rehabilitating boreholes with handpumps in resource-poor settings and hard-to-reach areas. METHODS: Diarrheal reduction in the population was predicted on the basis of the empirical findings from a cluster randomized controlled trial. The full investment and estimated annual running costs were used to calculate the intervention costs. Direct economic benefits of avoiding child diarrheal disease, indirect economic benefits related to health improvements, and non-health benefits related to water improvement were estimated. One-way and multi-way sensitivity analyses were performed to determine the robustness of the findings. RESULTS: Our analysis found that the return on a US$ 1 investment was US$ 9.4 for borehole drilling and US$ 14.1 for borehole rehabilitation. Time savings were the main contributor, accounting for 68% of the benefits, followed by the economic benefits of averted child deaths, which contributed to 15% of the benefits. The sensitivity analyses suggested that improving water sources yields high returns under all circumstances, and that borehole rehabilitation is more efficient than borehole drilling. CONCLUSION: This study explicitly justifies increased investment in water improvement in rural areas and demonstrates the high returns of rehabilitating boreholes. We hope that this study will be used as evidence for informing the policy decisions of governments or international agencies regarding further investments in improved water coverage in rural areas and the selection of appropriately designed interventions.

Trends of improved water and sanitation coverage around the globe between 1990 and 2010: inequality among countries and performance of official development assistance.

BACKGROUND: As the Millennium Development Goals ended, and were replaced by the Sustainable Development Goals, efforts have been made to evaluate the achievements and performance of official development assistance (ODA) in the health sector. In this study, we explore trends in the expansion of water and sanitation coverage in developing countries and the performance of ODA. DESIGN: We explored inequality across developing countries by income level, and investigated how ODA for water and sanitation was committed by country, region, and income level. Changes in inequality were tested via slope changes by investigating the interaction of year and income level with a likelihood ratio test. A random effects model was applied according to the results of the Hausman test. RESULTS: The slope of the linear trend between economic level and sanitation coverage has declined over time. However, a random effects model suggested that the change in slope across years was not significant (e.g. for the slope change between 2000 and 2010: likelihood ratio χ2 = 2.49, probability > χ2 = 0.1146). A similar pro-rich pattern across developing countries and a non-significant change in the slope associated with different economic levels were demonstrated for water coverage. Our analysis shows that the inequality of water and sanitation coverage among countries across the world has not been addressed effectively during the past decade. Our findings demonstrate that the countries with the least coverage persistently received far less ODA per capita than did countries with much more extensive water and sanitation coverage, suggesting that ODA for water and sanitation is poorly targeted. CONCLUSION: The most deprived countries should receive more attention for water and sanitation improvements from the world health community. A strong political commitment to ODA targeting the countries with the least coverage is needed at the global level.

Clinicopathological Features and Long-Term Outcomes of Intraductal Papillary Neoplasms of the Intrahepatic Bile Duct.

We intended to investigate the clinicopathological features of intrahepatic intraductal papillary neoplasms of the bile duct (IPNB), especially their malignant features and post-resection prognosis. Forty-three patients who met the definition of IPNB and who underwent liver resection between January 2002 and June 2015 were selected from our institutional database of liver resection cases. The mean age was 63.3 ± 6.9 years and 24 were male. Hepatolithiasis was present in addition in 10 of the patients. Left- and right-sided hepatectomies and concurrent bile duct resection (BDR) were performed in 28, 15, and 10 patients, respectively; R0 resection was performed in 37 patients. The mean tumor diameter was 4.1 ± 2.2 cm. Histological tumor grade was low in 4 cases, intermediate in 6, and malignant in 33. There was no cancer-related recurrence or death in the 10 patients with low-grade or intermediate lesions. In the 33 patients with malignant lesions, rates of tumor recurrence and overall survival were 12.5 and 96.2 % at 1 year, 36.4 and 91.3 % at 3 years, and 47.0 and 68.8 % at 5 years, respectively. Multivariate analysis showed that R1 resection was the only prognostic factor for tumor recurrence and patient survival. BDR was performed in only 2 of 6 patients undergoing R1 resection. Intrahepatic IPNB is a rare type of biliary neoplasm that encompasses a histological spectrum ranging from benign disease to invasive malignancy. Long-term survival was anticipated after curative resection. R1 resection reduced survival outcomes; therefore, we suggest that concurrent BDR should be performed if the resection margin of the bile duct is not reliably free of neoplastic involvement.

Clinicopathological features of the intraductal papillary neoplasms of the intrahepatic bile duct.

BACKGROUNDS/AIMS: This study is intended to investigate the clinicopathological features of the intraductal papillary neoplasms of the intrahepatic bile duct (IPNB), especially focused on malignant changes. METHODS: From the institutional database of liver resection cases (Asan Medical Center, University of Ulsan College of Medicine), 18 patients who met the definition of IPNB were selected. They had undergone liver resection between February 2002 and October 2006; thus, the follow-up period was more than 5 years. RESULTS: Of the 18 patients, 11 patients were male. Their mean age was 61.3±6.7 years. There were no differences between the non-malignant and malignant lesions, in the comparison of the CEA levels (5.6±2.7 vs.12.6±31.1 ng/ml, p=0.439) and the CA19-9 levels (29.2±34.7 vs.31.9±30.2 ng/ml, p=0.871). The common radiologic findings were: intraductal growing mass in 10; bile duct dilatation in 6; and saccular duct dilatation in 2. Left and right hepatectomies were performed in 15 and 3, respectively. Five patients showed benign lesions of IPNB, and 13 patients revealed malignant lesions of intraductal papillary adnocarcinoma or cholangiocarcinoma. All 4 patients with benign lesions survived for a mean period of 53 months without recurrence. In 13 patients with the malignant lesions, 1-year, 3-year, and 5-year survival rates were 100%, 84.6%, and 59.2%, respectively. CONCLUSIONS: We concluded that intrahepatic IPNB is a rare type of biliary neoplasm which includes a histological spectrum, ranging from benign disease to invasive malignancy. The long-term survival was anticipated after complete curative resection.

Extent of resection for T2N0 gallbladder carcinoma regarding concurrent extrahepatic bile duct resection.

BACKGROUNDS/AIMS: Gallbladder carcinoma (GBCa) T2 lesions are considered to be advanced tumors showing diverse features in tumor extent. When this T2 lesion does not involve the cystic duct and there is no evidence of lymph node metastasis, we have to consider what is the most reasonable extent of resection - that is, whether to perform concurrent extra-hepatic bile duct resection (EHBD) resection or not. This study intends to evaluate the adequacy of EHBD resection in patients undergoing resection for T2N0 GBCa. METHODS: From our institutional database of GBCa, 48 cases of T2N0 GBCa who underwent R0 resection during November 1995 and August 2008 were selected. Patients who underwent prior laparoscopic cholecystectomy were excluded. Their medical records were reviewed retrospectively. RESULTS: Their mean age was 63.2±83.3 years and females were 25. The mean serum CA19-9 level was 37.3±89.3 ng/ml. The extents of liver resection were wedge resection (n=36) and segment 4a+5 resection (n=12). Concurrent EHBD resection was performed in 16 (33.3%) patients. No fatal surgical complication occurred. The majority of tumor pathology was adenocarcinoma (n=42), with additional unusual types as papillary (n=3), saromatoid (n=1), signet ring cell (n=1) and adenosquamous (n=1) cancers. The overall survival rate was 87.1% at 1 year, 69.5% at 3 years and 61.7% at 5 years. After exclusion of mortalities not related to cancer, the overall patient survival rate was 89.6% at 1 year, 72.9% at 3 years and 64.7% at 5 years, with 3-year survival rates of 72% in the EHBD resection group and 69.2% in the non-resection group (p=0.661). CONCLUSIONS: The results of this study indicate that concurrent EHBD resection did not improve patient survival when R0 resection was achieved in patients with T2N0 GBCa. Therefore, routine EHBD resection may not be indicated for T2N0 GBCa unless the tumor is close to the cystic duct.

Characterization of an Agrobacterium tumefaciens D-psicose 3-epimerase that converts D-fructose to D-psicose.

The noncharacterized gene previously proposed as the D-tagatose 3-epimerase gene from Agrobacterium tumefaciens was cloned and expressed in Escherichia coli. The expressed enzyme was purified by three-step chromatography with a final specific activity of 8.89 U/mg. The molecular mass of the purified protein was estimated to be 132 kDa of four identical subunits. Mn2+ significantly increased the epimerization rate from D-fructose to D-psicose. The enzyme exhibited maximal activity at 50 degrees C and pH 8.0 with Mn2+. The turnover number (k(cat)) and catalytic efficiency (k(cat)/Km) of the enzyme for D-psicose were markedly higher than those for d-tagatose, suggesting that the enzyme is not D-tagatose 3-epimerase but D-psicose 3-epimerase. The equilibrium ratio between D-psicose and D-fructose was 32:68 at 30 degrees C. D-Psicose was produced at 230 g/liter from 700-g/liter D-fructose at 50 degrees C after 100 min, corresponding to a conversion yield of 32.9%.

Involvement of multidrug resistance associated protein 1 (Mrp1) in the efflux transport of 17beta estradiol-D-17beta-glucuronide (E217betaG) across the blood-brain barrier.

PURPOSE: The purpose of present study is to investigate the involve ment of multidrug resistance-associated protein 1 (Mrp1), Mrp2, an P-glycoprotein (Mdr1a) in the efflux transport of 17beta-estradiol-D-17beta-glucuronide (E217betaG) across the blood-brain barrier (BBB). METHOD: The expression of Mrp1 and Mrp2 at the BBB was investigated by RT-PCR and Western blot analyses. The time profiles of the remaining radioactivity of [3H]E217pG in the brain were compared in wild-type, Mdr1a/Mdr1b and Mrp1 knockout mice and normal and Mrp2-deficient mutant rats [Sprague-Dawley and Eisai hyperbilirubinemic rats (EHBR), respectively] after intracerebral microinjection. RESULTS: RT-PCR and Western blot analyses revealed the expression of Mrp1 in isolated rat brain capillary; however, RT-PCR was unable to detect any expression of Mrp2. Significant elimination of E217betaG was observed in wild-type mice at a rate constant of 0.007 min(-1) which was significantly decreased (0.004 min(-1)) in Mrp1 knockout mice. In contrast, there was no difference in the efflux of E217betaG from the brain in wild-type and Mdr1a/Mdr1b knockout mice and in normal and EHBR. No significant difference was observed in the accumulation of E217betaG by brain slices prepared from wild-type and Mrp1 knockout mice. CONCLUSION: Mrp1, but not Mrp2, is involved in the excretion of E217betaG at the BBB and provides a barrier function by extruding conjugated metabolites into the blood.

Increased xylitol production rate during long-term cell recycle fermentation of Candida tropicalis.

Long-term cell recycle fermentations of Candida tropicalis were performed over 14 rounds of fermentation. The average xylitol concentrations, fermentation times, volumetric productivities and product yields for 14 rounds were 105 g l(-1), 333 h, 4.4 g l(-1) h(-1) and 78%, respectively, in complex medium; and 110 g l(-1), 284 h, 5.4 g l(-1) h(-1) and 81%, respectively, in a chemically defined medium. These productivities were 1.7 and 2.4 times those with batch fermentation in the complex and chemically defined media, respectively. The xylitol yield from xylose with cell recycle fermentation using the chemically defined medium was 81% (w/w), which was 7% greater than the xylitol yield with batch fermentation (74%); both modes of fermentation gave the same yield using the complex medium. These results suggest that the chemically defined medium is more suitable for production of xylitol than complex medium.