963 resultados para [HbA.sup.1c]
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Biofuels are alternative fuels that have the promise of reducing reliance on imported fossil fuels and decreasing emission of greenhouse gases from energy consumption. This thesis analyses the environmental impacts focusing on the greenhouse gas (GHG) emissions associated with the production and delivery of biofuel using the new Integrated Hydropyrolysis and Hydroconversion (IH2) process. The IH2 process is an innovative process for the conversion of woody biomass into hydrocarbon liquid transportation fuels in the range of gasoline and diesel. A cradle-to-grave life cycle assessment (LCA) was used to calculate the greenhouse gas emissions associated with diverse feedstocks production systems and delivery to the IH2 facility plus producing and using these new renewable liquid fuels. The biomass feedstocks analyzed include algae (microalgae), bagasse from a sugar cane-producing locations such as Brazil or extreme southern US, corn stover from Midwest US locations, and forest feedstocks from a northern Wisconsin location. The life cycle greenhouse gas (GHG) emissions savings of 58%–98% were calculated for IH2 gasoline and diesel production and combustion use in vehicles compared to fossil fuels. The range of savings is due to different biomass feedstocks and transportation modes and distances. Different scenarios were conducted to understand the uncertainties in certain input data to the LCA model, particularly in the feedstock production section, the IH2 biofuel production section, and transportation sections.
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Maderas volcano is a small, andesitic stratovolcano located on the island of Ometepe, in Lake Nicaragua, Nicaragua with no record of historic activity. Twenty-one samples were collected from lava flows from Maderas in 2010. Selected samples were analyzed for whole-rock geochemical data using ICP-AES and/or were dated using the 40Ar/39Ar method. The results of these analyses were combined with previously collected data from Maderas as well as field observations to determine the eruptive history of the volcano and create a geologic map. The results of the geochemical analyses indicate that Maderas is a typical Central American andesitic volcano similar to other volcanoes in Nicaragua and Costa Rica and to its nearest neighbor, Concepción volcano. It is different from Concepción in one important way – higher incompatible elements. Determined age dates range from 176.8 ± 6.1 ka to 70.5 ± 6.1 ka. Based on these ages and the geomorphology of the volcano which is characterized by a bisecting graben, it is proposed that Maderas experienced two clear generations of development with three separate phases of volcanism: initial build-up of the older cone, pre-graben lava flows, and post-graben lava flows. The ages also indicate that Maderas is markedly older than Concepción which is historically active. Results were also analyzed regarding geologic hazards. The 40Ar/39Ar ages indicate that Maderas has likely been inactive for tens of thousands of years and the risk of future volcanic eruptions is low. However, earthquake, lahar and landslide hazards exist for the communities around the volcano. The steep slopes of the eroded older cone are the most likely source of landslide and lahar hazards.
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BACKGROUND: Chronic alcohol consumption is a risk factor for colorectal cancer. Animal experiments as well as genetic linkage studies in Japanese individuals with inactive acetaldehyde dehydrogenase leading to elevated acetaldehyde concentrations following ethanol ingestion support the hypothesis that acetaldehyde may be responsible for this carcinogenic effect of alcohol. In Caucasians, a polymorphism of alcohol dehydrogenase 1C (ADH1C) exists resulting in different acetaldehyde concentrations following ethanol oxidation. METHODS: To evaluate whether the association between alcohol consumption and colorectal tumor development is modified by ADH1C polymorphism, we recruited 173 individuals with colorectal tumors diagnosed by colonoscopy and 788 control individuals without colorectal tumors. Genotyping was performed using genomic DNA extracted from whole blood followed by polymerase chain reaction. RESULTS: Genotype ADH1C*1/1 was more frequent in patients with alcohol-associated colorectal neoplasia compared to patients without cancers in the multivariate model controlling for age, gender, and alcohol intake (odds ratio = 1.674, 95% confidence interval = 1.110-2.524, 2-sided p from Wald test = 0.0139). In addition, the joint test of the genetic effect and interaction between ADH1C genotype and alcohol intake (2-sided p = 0.0007) indicated that the difference in ADH1C*1 polymorphisms between controls and colorectal neoplasia is strongly influenced by the alcohol consumption and that only individuals drinking more than 30 g ethanol per day with the genotype ADH1C*1/1 had an increased risk for colorectal tumors. CONCLUSIONS: These data identify ADH1C homozygosity as a genetic risk marker for colorectal tumors in individuals consuming more than 30 g alcohol per day and emphasize the role of acetaldehyde as a carcinogenic agent in alcohol-related colorectal carcinogenesis.
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In the treatment of copper ores by hydro-electro-metallurgical methods, not only is copper deposited, but other metals are also dissolved. In practice it has been found* that iron, under certain conditions, causes the copper to deposit on the cathode as a nonadherent precipitate and also that the iron in solution causes a great decrease in current efficiency, especially when the electrolysis is conducted by operating with a higher current density at the cathode than at the anode. The present investigation deals with the effects of the two valences of iron on the current efficiency and endeavors to determine whether or not there is a ratio of the two at which point the efficiency becomes zero or approaches it.
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BACKGROUND: Unlike most antihyperglycaemic drugs, glucagon-like peptide-1 (GLP-1) receptor agonists have a glucose-dependent action and promote weight loss. We compared the efficacy and safety of liraglutide, a human GLP-1 analogue, with exenatide, an exendin-based GLP-1 receptor agonist. METHODS: Adults with inadequately controlled type 2 diabetes on maximally tolerated doses of metformin, sulphonylurea, or both, were stratified by previous oral antidiabetic therapy and randomly assigned to receive additional liraglutide 1.8 mg once a day (n=233) or exenatide 10 microg twice a day (n=231) in a 26-week open-label, parallel-group, multinational (15 countries) study. The primary outcome was change in glycosylated haemoglobin (HbA(1c)). Efficacy analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00518882. FINDINGS: Mean baseline HbA(1c) for the study population was 8.2%. Liraglutide reduced mean HbA(1c) significantly more than did exenatide (-1.12% [SE 0.08] vs -0.79% [0.08]; estimated treatment difference -0.33; 95% CI -0.47 to -0.18; p<0.0001) and more patients achieved a HbA(1c) value of less than 7% (54%vs 43%, respectively; odds ratio 2.02; 95% CI 1.31 to 3.11; p=0.0015). Liraglutide reduced mean fasting plasma glucose more than did exenatide (-1.61 mmol/L [SE 0.20] vs -0.60 mmol/L [0.20]; estimated treatment difference -1.01 mmol/L; 95% CI -1.37 to -0.65; p<0.0001) but postprandial glucose control was less effective after breakfast and dinner. Both drugs promoted similar weight losses (liraglutide -3.24 kg vs exenatide -2.87 kg). Both drugs were well tolerated, but nausea was less persistent (estimated treatment rate ratio 0.448, p<0.0001) and minor hypoglycaemia less frequent with liraglutide than with exenatide (1.93 vs 2.60 events per patient per year; rate ratio 0.55; 95% CI 0.34 to 0.88; p=0.0131; 25.5%vs 33.6% had minor hypoglycaemia). Two patients taking both exenatide and a sulphonylurea had a major hypoglycaemic episode. INTERPRETATION: Liraglutide once a day provided significantly greater improvements in glycaemic control than did exenatide twice a day, and was generally better tolerated. The results suggest that liraglutide might be a treatment option for type 2 diabetes, especially when weight loss and risk of hypoglycaemia are major considerations.
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The exact mechanism for capillary occlusion in diabetic retinopathy is still unclear, but increased leukocyte-endothelial cell adhesion has been implicated. We examined the possibility that posttranslational modification of surface O-glycans by increased activity of core 2 transferase (UDP-Glc:Galbeta1-3GalNAcalphaRbeta-N-acetylglucoaminyltr ansferase) is responsible for increased adhesion of leukocytes to vascular endothelium in diabetes. The mean activity of core 2 transferase in polymorphonuclear leukocytes isolated from type 1 and type 2 diabetic patients was higher compared with age-matched control subjects (1,638 +/- 91 [n = 42] vs. 249 +/- 35 pmol x h(-1) x mg(-1) protein [n = 24], P = 0.00013; 1,459 +/- 194 [n = 58] vs. 334 +/- 86 [n = 11], P = 0.01). As a group, diabetic patients with retinopathy had significantly higher mean activity of core 2 transferase compared with individuals with no retinopathy. There was a significant association between enzyme activity and severity of retinopathy in type 1 and type 2 diabetic patients. There was a strong correlation between activity of core 2 transferase and extent of leukocyte adhesion to cultured retinal capillary endothelial cells for diabetic patients but not for age-matched control subjects. Results from transfection experiments using human myelocytic cell line (U937) demonstrated a direct relationship between increased activity of core 2 transferase and increased binding to cultured endothelial cells. There was no relationship between activity of core 2 transferase and HbA(1c) (P = 0.8314), serum advanced glycation end product levels (P = 0.4159), age of the patient (P = 0.7896), and duration of diabetes (P = 0.3307). On the basis that branched O-glycans formed by the action of core 2 transferase participate in leukocyte adhesion, the present data suggest the involvement of this enzyme in increased leukocyte-endothelial cell adhesion and the pathogenesis of capillary occlusion in diabetic retinopathy.
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During the last glacial cycle, Greenland temperature showed many rapid temperature variations, the so-called Dansgaard–Oeschger (DO) events. The past atmospheric methane concentration closely followed these temperature variations, which implies that the warmings recorded in Greenland were probably hemispheric in extent. Here we substantially extend and complete the North Greenland Ice Core Project (NGRIP) methane record from the Preboreal Holocene (PB) back to the end of the last interglacial period with a mean time resolution of 54 yr. We relate the amplitudes of the methane increases associated with DO events to the amplitudes of the local Greenland NGRIP temperature increases derived from stable nitrogen isotope (δ15N) measurements, which have been performed along the same ice core (Kindler et al., 2014). We find the ratio to oscillate between 5 parts per billion (ppb) per °C and 18 ppb °C−1 with the approximate frequency of the precessional cycle. A remarkably high ratio of 25.5 ppb °C−1 is reached during the transition from the Younger Dryas (YD) to the PB. Analysis of the timing of the fast methane and temperature increases reveals significant lags of the methane increases relative to NGRIP temperature for DO events 5, 9, 10, 11, 13, 15, 19, and 20. These events generally have small methane increase rates and we hypothesize that the lag is caused by pronounced northward displacement of the source regions from stadial to interstadial. We further show that the relative interpolar concentration difference (rIPD) of methane is about 4.5% for the stadials between DO events 18 and 20, which is in the same order as in the stadials before and after DO event 2 around the Last Glacial Maximum. The rIPD of methane remains relatively stable throughout the full last glacial, with a tendency for elevated values during interstadial compared to stadial periods.
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In 2005, two ice cores with lengths of 58.7 and 57.6 m respectively to bedrock were recovered from the Miaoergou flat-topped glacier (43 degrees 03 ' 19 '' N, 94 degrees 19 ' 21 '' E; 4512 m a.s.l.), eastern Tien Shan. Pb-210 dating of one of the ice cores (57.6 m) was performed, and an age of AD 1851 +/- 6 at a depth of 35.2 m w.e. was determined. For the period AD 1851-2005, a mean annual net accumulation of 229 +/- 7 mm w.e. a(-1) was calculated. At the nearby oasis city of Hami (similar to 80 km from the Miaoergou flat-topped glacier) the annual precipitation rate is 38 mm w.e. a(-1), hence glacial meltwater is a major water supply for local residents. The surface activity concentration of Pb-210(ex) was found to be similar to 400 mBq kg(-1), which is higher than observed at other continental sites such as Belukha, Russia, and Tsambagarav, Mongolia, which have surface activity concentrations of 280 mBq kg(-1). The Pb-210 dating agrees well with the chronological sequence deduced from the annual-layer counting resulting from the seasonalities of delta O-18 and trace metals for the period AD 1953-2005, and beta-activity horizons resulting from atmospheric nuclear testing during the period AD 1962-63. We conclude that Pb-210 analysis is a suitable method for obtaining a continuous dating of the Miaoergou ice core for similar to 160 years, which can also be applied to other ice cores recovered from the mountains of western China.
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Purpose. This cross-sectional, observational study explored differences among groups staged for intent to decrease dietary fat intake in women with type 2 diabetes in relation to demographic, weight concern, physiological, and psychosocial variables. ^ Methods. A sample of 100 community-dwelling, English-speaking women, who were over age 30 and had type 2 diabetes for at least a year, was accessed through a culturally diverse endocrinology clinic. Subjects completed 7 self-report instruments: demographic sheet, with 11-point weight satisfaction scale; staging algorithm; fat intake (MEDFICTS); depression (CES-D); diabetes-specific dietary knowledge (ADKnowl), social support and self-efficacy scales (SE-Type 2). Physiological variables were abstracted from the medical record (HbA 1c, blood pressure, serum cholesterol and triglycerides). ^ Results. The women's average age was 57.69 years ( SD = 3.07); 50% were married. Subjects were well-educated ( M = 14 years; SD = 3.33), with average diabetes duration of 10.57 years (SD = 9.11), high body mass index (M = 35.72; SD = 8.36), low diabetes-specific dietary knowledge, low weight satisfaction, but in good diabetes control. Racial/ethnic composition was 44% non-Hispanic-White-American, 18% Hispanic-White-American, 15% non-Hispanic-African-American, 16% Hispanic-African-American and 5% other. Fat intake was low and differed by racial/ethnic demographics. The highest fat intake scores were for non-Hispanic-African-Americans (M = 53), followed by Hispanic-White-Americans (M = 51), non-Hispanic-White-Americans (M = 45), and Hispanic-African-Americans (M = 32), who had the lowest fat intake scores. ^ MANOVA analyses revealed no significant differences between stages of behavior change in relation to psychosocial or weight concern variables, age, education, HbA1c, or cholesterol levels. Single women were more likely to be in the three preaction stages (precontemplation, contemplation, and preparation); married women were equally distributed across stages (the preaction stages plus action and maintenance). African-American women (Hispanic and non-Hispanic) were more likely in contemplation and preparation. Triglycerides were higher in women in the action stage than contemplation or preparation. Systolic blood pressure was higher in action than preparation; diastolic blood pressure was higher in action than preaction. ^ Conclusions. Healthcare professionals should consider race, ethnicity, and marital status in client interactions. Dietary intake can vary according to both race and ethnicity; collapsing racial/ethnic groups can alter means and distributions, generating faulty conclusions. Further research is warranted to explore relationships between dietary self-care and marital status, race, ethnicity, and physiological variables. ^