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Sample records for glucose analogs measured

  1. Measuring brain glucose phosphorylation with labeled glucose

    DEFF Research Database (Denmark)

    Brøndsted, H E; Gjedde, A

    This study tested whether glucose labeled at the C-6 position generates metabolites that leave brain so rapidly that C-6-labeled glucose cannot be used to measure brain glucose phosphorylation (CMRGlc). In pentobarbital-anesthetized rats, the parietal cortex uptake of [14C]glucose labeled in the C...

  2. Measuring brain glucose phosphorylation with labeled glucose

    International Nuclear Information System (INIS)

    This study tested whether glucose labeled at the C-6 position generates metabolites that leave brain so rapidly that C-6-labeled glucose cannot be used to measure brain glucose phosphorylation (CMRGlc). In pentobarbital-anesthetized rats, the parietal cortex uptake of [14C]glucose labeled in the C-6 position was followed for times ranging from 10 s to 60 min. We subtracted the observed radioactivity from the radioactivity expected with no loss of labeled metabolites from brain by extrapolation of glucose uptake in an initial period when loss was negligible. The observed radioactivity was a monoexponentially declining function of the total radioactivity expected in the absence of metabolite loss. The constant of decline was 0.0077.min-1 for parietal cortex. Metabolites were lost from the beginning of the experiment. However, with correction for the loss of labeled metabolites, it was possible to determine an average CMRGlc between 4 and 60 min of circulation of 64 +/- 4 (SE; n = 49) mumol.hg-1.min-1

  3. Analog to Digital Conversion in Physical Measurements

    OpenAIRE

    Kapitaniak, T.; Zyczkowski, K.; Feudel, U.; Grebogi, C.

    1999-01-01

    There exist measuring devices where an analog input is converted into a digital output. Such converters can have a nonlinear internal dynamics. We show how measurements with such converting devices can be understood using concepts from symbolic dynamics. Our approach is based on a nonlinear one-to-one mapping between the analog input and the digital output of the device. We analyze the Bernoulli shift and the tent map which are realized in specific analog/digital converters....

  4. Analog to Digital Conversion in Physical Measurements

    CERN Document Server

    Kapitaniak, T; Feudel, U; Grebogi, C

    1999-01-01

    There exist measuring devices where an analog input is converted into a digital output. Such converters can have a nonlinear internal dynamics. We show how measurements with such converting devices can be understood using concepts from symbolic dynamics. Our approach is based on a nonlinear one-to-one mapping between the analog input and the digital output of the device. We analyze the Bernoulli shift and the tent map which are realized in specific analog/digital converters. Furthermore, we discuss the sources of errors that are inevitable in physical realizations of such systems and suggest methods for error reduction.

  5. Positron emission tomographic measurements of cerebral glucose utilization using [1-11C]D-glucose

    International Nuclear Information System (INIS)

    Regional CMRglc was measured in seven healthy volunteers with positron emission tomography using [1-11C]D-glucose. Regional CBF was measured using [11C]fluoromethane. The arteriovenous differences of unlabeled glucose and oxygen together with 11C metabolites were also measured. In addition to the loss of [11C]CO2, a loss of acidic 11C metabolites was also detected. A three-compartment model was applied to the tracer data in the time interval 0-24 min. After correction for the loss of 11C metabolites, the tracer method gave an average CMRglc of 26.4 +/- 1.9 (SD) mumol/100 g/min, close to the value obtained with the Fick principle. After correction for the loss of [11C]CO2 only, the tracer method gave 23.6 +/- 2.1 mumol/100 g/min, compatible with (1/6) CMRO2, obtained with the Fick principle. These results and the time course of the loss of acidic 11C metabolites are consistent with the presence of nonoxidative metabolism of glucose that causes an early loss of mainly [11C]lacetate after a bolus injection of the tracer. This implies that [1-11C]D-glucose measures the rate of glucose oxidation rather than the total CMRglc. The experiments using [1-11C]D-glucose were compared to five analogous experiments using [U-11C]D-glucose together with [15O]H2O as a flow tracer. After correction for the loss of [11C]CO2, the two glucose tracers gave similar global values of CMRglc and other parameters associated with glucose utilization, but with labeling in the carbon-1 position, the loss of [11C]CO2 was substantially delayed and the contrast between gray and white matter was improved

  6. Cancer detection by F-18 fluorinated glucose analogs

    International Nuclear Information System (INIS)

    18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) and 18F-2-fluoro-2-deoxy-D-mannose (18F-FDM) were tested as tumor diagnostic agents in transplanted rat and rabbit tumors. Tissue distribution studies of rat showed high tumor uptake and low normal tissue uptakes of the the radiopharmaceuticals. Autoradiograms of the whole rats also showed high tumor radioactivity. Positron emission tomography of rabbit tumor delineated clearly the tumor and metastatic lymphnodes. These data showed that both agents were excellent cancer diagnostic agents

  7. Glucose concentration measurement using photoacoustic technique

    Science.gov (United States)

    Huang, Zhen; Liu, Guodong; Ren, Zhong; Zeng, Lvming

    2015-08-01

    In this paper, a noninvasive photoacoustic measurement setup was established to simple simulate the glucose concentration measurement. The PPA signal excited by a pulsed tunable wavelength laser can be used to determine the glucose concentration in solution. By building the multiple linear regression (MLR) model for the peak valves of the PPA signal at five characteristic absorption wavelengths, the relative error of prediction is less than 20% and the absolute error is less than 33mg/dL.

  8. Potent humanin analog increases glucose-stimulated insulin secretion through enhanced metabolism in the ? cell

    OpenAIRE

    Kuliawat, Regina; Klein, Laura; Gong, Zhenwei; Nicoletta-Gentile, Marianna; NEMKAL, ANJANA; Cui, Lingguang; Bastie, Claire; Su, Kai; Huffman, Derek; Surana, Manju; Barzilai, Nir; Fleischer, Norman; Muzumdar, Radhika

    2013-01-01

    Humanin (HN) is a 24-aa polypeptide that offers protection from Alzheimer's disease and myocardial infarction, increases insulin sensitivity, improves survival of ? cells, and delays onset of diabetes. Here we examined the acute effects of HN on insulin secretion and potential mechanisms through which they are mediated. Effects of a potent HN analog, HNGF6A, on glucose-stimulated insulin secretion (GSIS) were assessed in vivo and in isolated pancreatic islets and cultured murine ? cell line (...

  9. Estimation of glucose utilization in a type 2 diabetes mellitus patient on insulin analogs with tumor hypoglycemia induced by IGF-II.

    Science.gov (United States)

    Chode, Suresh; Albert, Stewart G; Shoemaker, James D; Green, Aileen L

    2016-02-01

    We present a 38-year-old male patient with insulin requiring type 2 diabetes mellitus (DM) who had fasting hypoglycemia caused by a non-pancreatic-islet-cell mesenchymal tumor producing IGF-II. The evaluation was confounded in that there was pre-existing DM being treated with insulin analogs. Insulin levels were assessed with an immunoassay with cross reactivity with the insulin analogs. An 18-Fluorodeoxyglucose (FDG) positron emission tomography/computerized tomography (PET/CT) scan localized the 19.7×18.0×17.8cm retroperitoneal mass. A 3.25kg tumor was resected. Post-operatively insulin treatment was resumed and circulating IGF-II levels returned to normal. The maximum standardized uptake values of FDG (SUVmax) along with a steady state glucose infusion of 17.5g/h were used to determine the components of glucose utilization due to IGF-II induced muscle glucose uptake (utilization, 62%) whereas the tumor itself was responsible for approximately 22% of measurable glucose uptake. Whereas tumor induced hypoglycemia has been ascribed to preferential glucose utilization by the tumor, the predominant hypoglycemic effect was due to hormonal IGF-II induced total body glucose uptake. PMID:26774399

  10. Activity of P536, a UDP-glucose analog, against Trypanosoma cruzi

    International Nuclear Information System (INIS)

    P536, a UDP-glucose analog which was previously described as an antiviral agent, has a potent and selective activity against the intracellular and extracellular stages of Trypanosoma cruzi in vitro. It had a 50% inhibitory concentration of less than 5 micrograms/ml for T. cruzi extracellular cultured forms (epimastigote) and of 25 micrograms/ml for T. cruzi intracellular forms (amastigote) growing inside J774G8 macrophage-like cells. In contrast, the 50% inhibitory concentration was 100 micrograms/ml or greater for cultured mammalian cells and 180 micrograms/ml for the proliferation of mouse spleen lymphocytes. Furthermore, the addition of P536 (50 micrograms/ml) to T. cruzi-infected J774G8 cells cured the infected macrophages, making them able to grow and function normally. Studies on the mechanism of action of this drug indicated that it inhibited incorporation of [35S]methionine, [3H]thymidine, [3H]mannose, [14C]-N-acetylglucosamine, and [3H]uridine into macromolecules by T. cruzi epimastigotes, the last being the most sensitive

  11. Contribution to a decision making model for analogical measurement validation

    International Nuclear Information System (INIS)

    In limits of studies taken on validity of analogic measures in nuclear power plant's operation, the present thesis takes aim at establishment of a model to reaching a decision on the indice of probability on measures obtained by preliminary validation system. In a first step, it is proposed to retain a system made by redundant measures in which the calcul of measures is based on the coherence between measures themselves and logic vote. In the second step, one equation is proposed to compute the index of probability of measures taken in account, the characteristics of the system

  12. Double-label autoradiographic deoxyglucose method for sequential measurement of regional cerebral glucose utilization

    International Nuclear Information System (INIS)

    A new double-label autoradiographic glucose analog method for the sequential measurement of altered regional cerebral metabolic rates for glucose in the same animal is presented. This method is based on the sequential injection of two boluses of glucose tracer labeled with two different isotopes (short-lived 18F and long-lived 3H, respectively). An operational equation is derived which allows the determination of glucose utilization for the time period before the injection of the second tracer; this equation corrects for accumulation and loss of the first tracer from the metabolic pool occurring after the injection of the second tracer. An error analysis of this operational equation is performed. The double-label deoxyglucose method is validated in the primary somatosensory (''barrel'') cortex of the anesthetized rat. Two different rows of whiskers were stimulated sequentially in each rat; the two periods of stimulation were each preceded by an injection of glucose tracer. After decapitation, dried brain slices were first exposed, in direct contact, to standard X-ray film and then to uncoated, ''tritium-sensitive'' film. Results show that the double-label deoxyglucose method proposed in this paper allows the quantification and complete separation of glucose utilization patterns elicited by two different stimulations sequentially applied in the same animal. (author)

  13. A new application of electrical impedance spectroscopy for measuring glucose metabolism: a phantom study

    Science.gov (United States)

    Dhurjaty, Sreeram; Qiu, Yuchen; Tan, Maxine; Liu, Hong; Zheng, Bin

    2015-03-01

    Glucose metabolism relates to biochemical processes in living organisms and plays an important role in diabetes and cancer-metastasis. Although many methods are available for measuring glucose metabolism-activities, from simple blood tests to positron emission tomography, currently there is no robust and affordable device that enables monitoring of glucose levels in real-time. In this study we tested feasibility of applying a unique resonance-frequency based electronic impedance spectroscopy (REIS) device that has been, recently developed to measure and monitor glucose metabolism levels using a phantom study. In this new testing model, a multi-frequency electrical signal sequence is applied and scanned through the subject. When the positive reactance of an inductor inside the device cancels out the negative reactance of the capacitance of the subject, the electrical impedance reaches a minimum value and this frequency is defined as the resonance frequency. The REIS system has a 24-bit analog-to-digital signal convertor and a frequency-resolution of 100Hz. In the experiment, two probes are placed inside a 100cc container initially filled with distilled water. As we gradually added liquid-glucose in increments of 1cc (250mg), we measured resonance frequencies and minimum electrical signal values (where A/D was normalized to a full scale of 1V). The results showed that resonance frequencies monotonously decreased from 243kHz to 178kHz, while the minimum voltages increased from 405mV to 793mV as the added amount of glucose increased from 0 to 5cc. The study demonstrated the feasibility of applying this new REIS technology to measure and/or monitor glucose levels in real-time in future.

  14. Miniatured blood glucose measurement module interfaced with cellular phone.

    Science.gov (United States)

    Jun, Byung-Gu; Park, Kyung-Soon; Kim, Seong-Sik; Park, Mi-Sook; Kim, Kyung-Ah; Lee, Tae-Soo; Cha, Eun-Jung

    2006-01-01

    Chronic diabetes requires systematic disease management that considers the patients' personal characteristics such as age and sex. The bureaucratic complexity of the Korean medical system lowers the efficiency of diabetes management. The present study developed a miniature blood glucose meter interfaced through the serial port of a cellular phone. The measured glucose level is displayed and efficiently managed by the customized GUI program run on the mobile platform. The present results demonstrate a new medical application example of mobile telecommunication technology. PMID:17102428

  15. Subcutaneous capillary filtrate collector for measurement of blood glucose.

    Science.gov (United States)

    Ash, S R; Poulos, J T; Rainier, J B; Zopp, W E; Janle, E; Kissinger, P T

    1992-01-01

    The capillary filtrate collector (CFC) is a device that creates an ultrafiltrate at 50-100 microliters/h from subcutaneous capillaries, and carries this filtrate out of the body for chemical analysis. From inside out, components include three looped hollow fiber ultrafiltration membranes, a polytetrafluoroethylene (PTFE) cuff, polyurethane tubing, a "Y" connector leading to a sampling port, a hub, and a needle placed into a 5 ml vacutainer tube. Animal studies have demonstrated that the CFC filtrate glucose level is exactly that of blood at the time the filtrate is created. The authors have performed clinical trials to determine the correlation of blood glucose and CFC glucose levels, and the time delay between contemporary samples. Seven diabetic patients wore the CFC device, tubing, and vacutainer tube for 1 month. In home monitored diabetic patients, fingerstick glucose measurements were performed at the usual daily schedule. The vacutainer was then evacuated, and this average sample analyzed and compared with the average of prior blood glucose levels. An optical device then was applied to measure the linear velocity of CFC fluid through external tubing, and predict the time for fluid to pass from fibers to the sampling port (average, 25 min). Capillary filtrate collector samples drawn at this time had glucose concentrations that generally correlated with blood levels. In diabetic patients on hemodialysis, the vacutainer was evacuated at the start of each treatment, and CFC and blood samples were drawn every 20 min during the treatment. Comparison of glucose-versus-time curves indicated a reasonable correlation between blood and CFC samples, with a delay related to flow rate (which declined 50% during dialysis).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1457893

  16. Fluorescence lifetime measurements of boronate derivatives to determine glucose concentration

    Energy Technology Data Exchange (ETDEWEB)

    Gable, J H

    2000-06-01

    A novel investigation into the fluorescence lifetimes of molecules, both established and newly designed, was performed. These molecules are the basis of a continuous, minimally invasive, glucose sensor based on fluorescence lifetime measurements. This sensor, if coupled with an automated insulin delivery device, would effectively create an artificial pancreas allowing for the constant monitoring and control of glucose levels in a person with diabetes. The proposed sensor includes a fluorescent molecule that changes its' fluorescence properties upon binding selectively and reversibly to glucose. One possible sensor molecule is N-methyl-N-(9-methylene anthryl)-2-methylenephenylboronic acid (AB). The fluorescence intensity of AB was shown to change in response to changing glucose concentrations. (James, 1994) James proposed that when glucose binds to AB the fluorescence intensity increases due to an enhancement of the N{yields}B dative bond which prevents photoinduced electron transfer (PET). PET from the amine (N) to the fluorophore (anthracene) quenches the fluorescence. The dative bond between the boron and the amine can prevent PET by involving the lone pair of electrons on the amine in interactions with the boron rather than allowing them to be transferred to the fluorophore. Results of this research show the average fluorescence lifetime of AB also changes with glucose concentration. It is proposed that fluorescence is due to two components: (1) AB with an enhanced N{yields}B interaction, and no PET, and (2) AB with a weak N{yields}B interaction, resulting in fluorescence quenching by PET. Lifetime measurements of AB as a function of both the pH of the solvent and glucose concentration in the solution were made to characterize this two component system and investigate the nature of the N{yields}B bond. Measurements of molecules similar to AB were also performed in order to isolate behavior of specific AB constituents. These molecules are 9-(Methylaminomethyl)-anthracene (MAMA), and N-benzyl-N-methyl-N-methyl anthracene (AB-B). Fluorescence lifetime measurements confirmed the two species of AB, with and without PET. Fluorescence lifetimes were approximately 11 nsec without PET and 3 nsec with PET. The degree of the interaction between the N and the B atoms was also determined by fluorescence lifetime measurements. Electron transfer rates of AB were measured to be on the order of 10{sup 8} sec{sup -1}. Analysis of AB as a glucose sensor shows it has the potential for measuring glucose concentrations in solution with less than 5% error. Two novel glucose sensing molecules, Chloro-oxazone boronate (COB) and Napthyl-imide boronate (NIB), were synthesized. Both molecules have a N{yields}B dative bond similar to AB, but with longer wavelength fluorophores. COB and NIB were found to be unacceptable for use as glucose sensor molecules due to the small changes in average fluorescence lifetime.

  17. A New Digit Positioning Method for Analog Measuring Instruments

    Directory of Open Access Journals (Sweden)

    Zhenhua Wei

    2013-04-01

    Full Text Available For the automatic digit positioning of analogy measuring instruments, a positioning method based on coordinate transformation which has practical application is brought forward. And for the present, the mostly used ways for this field are method based on Hough transform and method based on circle scanning. But they have some defects such as time-consuming and complex or low accuracy rate. The method in this study is proposed to solve the above problems. It is primarily based on the coordinate transformation and projection operation to realize the object of digit positioning. By experiment, the validity and feasibility of the positioning method based on coordinate transformation are confirmed. It is shown that the average accuracy is improved by 5.4% and average positioning efficiency is improved by 8.73% compared to the present methods.

  18. Noninvasive blood glucose measurement using multiple laser diodes

    Science.gov (United States)

    Ooi, E. T.; Zhang, X. Q.; Chen, J. H.; Soh, P. H.; Ng, K.; Yeo, J. H.

    2007-02-01

    In the event of diabetes clinicians have advocated that frequent monitoring of a diabetic's blood glucose level is the key to avoid future complications (kidney failure, blindness, amputations, premature death, etc.,) associated with the disease. While the test-strip glucose meters available in current consumer markets allow for frequent monitoring, a more convenient technique that is accurate, painless and sample-free is preferable in a diabetic's daily routine. This paper presents a non-invasive blood glucose measurement technique using diffuse reflectance near infrared (NIR) signals. This technique uses a set of laser diodes, each operating at fixed wavelengths in the first overtone region. The NIR signals from the laser diodes are channeled to the measurement site viz., the nail-bed by means of optical fibers. A series of in vivo experiments have been performed on eight normal human subjects using a standard Oral Glucose Tolerance Test (OGTT) protocol. The reflected NIR signals are inputs to a Partial Least Squares (PLS) algorithm for calibration and future predictions. The calibration models used are developed using in vivo datasets and are unique to a particular individual. The 1218 paired points collected from the eight test subjects plotted on the Clarke Error Grid, revealed that 87.3% of these points fall within the A zone while the remainder, within the B zone, both of which, are clinically accepted. The standard error of prediction was +/-13.14mg/dL for the best calibration model. A Bland-Altman analysis of the 1218 paired points yields a 76.3% confidence level for a measurement accuracy of +/-20mg/dL. These results demonstrate the initial potential of the technique for non-invasive blood glucose measurements in vivo.

  19. Multidoored analogical scintigraphic device. Measurement of the ejection fraction

    International Nuclear Information System (INIS)

    The determination of left ventricular ejection fraction and radionuclide ventriculography can easily be obtained in analog mode with a modified multiimaging device triggered by the patient's electrocardiogram

  20. Measurement of lactate formation from glucose using [6-3H]- and [6-14C]glucose in humans

    International Nuclear Information System (INIS)

    To assess the validity of determining the origin of plasma lactate from the ratio of lactate and glucose specific activities (SA) during infusion of labeled glucose, normal subjects received infusions of [6-3H]- and [6-14C]glucose for 4 h after a 12 h fast, and, on another day, cold glucose labeled with both tracers during 4-6 h of hyperinsulinemia (approximately 650 microU/ml). Basally, less lactate was derived from plasma glucose when measured with [6-3H]glucose (27 +/- 2%) than with [6-14C]glucose (40 +/- 2%, P less than 0.001). Insulin did not increase the percent of lactate derived from plasma glucose when measured with [6-3H]glucose (29 +/- 2%) but did increase when measured with [6-14C]glucose (60 +/- 4%). The arterialized blood (A) [3H]lactate SA was 30-40% higher (P less than 0.01) than deep venous blood (V) [3H]lactate SA, whereas A and V [14C]lactate SA were similar. During conversion of alanine to lactate with glutamic-pyruvic transaminase (GPT) and lactate dehydrogenase (LDH) in vitro, 32 +/- 2% of 3H in [3-3H]alanine was found in water and 68 +/- 2% in lactate. During infusion of [6-3H]- and [6-14C]glucose, the ratio of [14C]alanine to lactate SA (0.88 +/- 0.05) was less than the ratio of [3H]alanine to lactate SA (0.31 +/- 0.03, P less than 0.001). In conclusion (1) loss of 3H relative to 14C from position 6 in glucose occurs during lactate formation in extrahepatic tissues possibly due to the GPT reaction (alanine conversion to pyruvate), and (2) even under supraphysiologic hyperinsulinemic conditions not all of plasma lactate originates from plasma glucose

  1. Glucose Measurement by Affinity Sensor and Pulsed Measurements of Fluidic Resistances: Proof of Principle.

    Science.gov (United States)

    Beyer, Uwe; Wyss, Thomas; Robin, Franck; Heinemann, Lutz

    2014-01-01

    Affinity sensors for glucose are based on a different measuring principle than the commercially available amperometric needle type sensors: reversible affinity interaction of glucose with specific receptors is the primary recognition mechanism instead of an enzymatic glucose oxidation. A novel pulsed-flow micro-fluidic system was used to characterize first the viscosity of a sensitive liquid containing the glucose receptor Concanavalin A and dextran and in a second approach to characterize the geometry of a fluidic resistance. In the viscometric sensor, glucose of the sensitive liquid is equilibrated, while passing through a dialysis chamber, with the surrounding medium. With the membrane flow sensor, the viscosity of the liquid remains constant but the pores of the flow-resisting membrane contain a swellable hydrogel affecting the width of the pores. Two types of hydrogel were tested with the membrane flow sensor; one is highly sensitive to pH and salt concentration, the other contains receptors of phenyl boronic acids to obtain sensitivity to glucose. The viscometric affinity sensor (first approach) showed a linear response over 0 to 30 mmol/L glucose concentration range. The disturbing effect of air bubbles could be compensated for. The sensing proof of principle of the second approach could be demonstrated by its linear response to different saline concentrations; however, the glucose-sensitive membrane developed showed only a small response to glucose. Glucose monitoring based on this pulsed flow measuring principle offers interesting alternatives for the development of CGM systems with different options for the glucose sensing part. PMID:24876545

  2. Blood glucose measurement by using hollow optical fiber-based attenuated total reflection probe

    Science.gov (United States)

    Kino, Saiko; Tanaka, Yuki; Matsuura, Yuji

    2014-05-01

    A noninvasive glucose monitoring system based on mid-infrared, attenuated total reflection spectroscopy using a hollow optical fiber probe is developed. Owing to the flexible fiber probe, measurement of oral mucosa, where blood capillaries are near the skin surface, is possible. Blood glucose levels are measured by detecting the peak intensity of glucose absorption bands, and the experimental results showed that the reproducibility of the measurement is high enough for monitoring blood glucose.

  3. Investigation of (/sup 18/F)2-fluoro-2-deoxyglucose for the measure of myocardial glucose metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, M.E.; Hoffman, E.J.; Selin, C.; Huang, S.C.; Robinson, G.; MacDonald, N.; Schelbert, H.; Kuhl, D.E.

    1978-12-01

    Fluorine-18-labeled 2-deoxyglucose (FDG) was studied as a glucose analog for the measure of myocardial glucose metabolism. Myocardial uptake and retention, blood clearance, species dependence (dog, monkey, man), and effect of diet on uptake were investigated. Normal myocardial uptake of FDG was 3 to 4% of injected dose in dog and monkey, and 1 to 4% in man, compared with brain uptakes of 1.5 to 3% in dog, 5 to 6% in monkey, and 4 to 8% in man. The myocardial metabolic rate (MR) for glucose in the nonfasting (glycolytic) state was 2.8 times that in the fasting (ketogenic) state. Human subjects showed higher myocardial uptake after a normal meal than after a meal containing mostly free fatty acids (FFA). Blood clearance was rapid with initial clearance t/sub 1/2/ of 0.2 to 0.3 min, followed by a t/sub 1/2/ of 8.4 +- 1.2 min in dog and 11.6 +- 1.1 min in man. A small third component had half-times of 59 +- 10 min and 88 +- 4 min in dog and man, respectively. With the ECAT positron tomograph, high image-contrast ratios were found between heart and blood (dog 3.5/1, man 14/1), heart and lung (dog 9/1, man 20/1), and heart and liver (dog 15/1, man 10/1). The FDG was taken up rapidly by the myocardium without any significant tissue clearance over a 4-hr period. The FDG exhibited excellent imaging properties. Average counting rates of 12K, 20K, and 40K c/min-mCi injected are obtained in human subjects with high, medium, and low resolutions of the ECAT tomograph. Determination of glucose and FFA MR in vivo with EACT provides a method for investigation and assessment of changing aerobic and anaerobic metabolic rates in ischemic heart disease in man.

  4. Investigation of [18F]2-fluoro-2-deoxyglucose for the measure of myocardial glucose metabolism

    International Nuclear Information System (INIS)

    Fluorine-18-labeled 2-deoxyglucose (FDG) was studied as a glucose analog for the measure of myocardial glucose metabolism. Myocardial uptake and retention, blood clearance, species dependence (dog, monkey, man), and effect of diet on uptake were investigated. Normal myocardial uptake of FDG was 3 to 4% of injected dose in dog and monkey, and 1 to 4% in man, compared with brain uptakes of 1.5 to 3% in dog, 5 to 6% in monkey, and 4 to 8% in man. The myocardial metabolic rate (MR) for glucose in the nonfasting (glycolytic) state was 2.8 times that in the fasting (ketogenic) state. Human subjects showed higher myocardial uptake after a normal meal than after a meal containing mostly free fatty acids (FFA). Blood clearance was rapid with initial clearance t/sub 1/2/ of 0.2 to 0.3 min, followed by a t/sub 1/2/ of 8.4 +- 1.2 min in dog and 11.6 +- 1.1 min in man. A small third component had half-times of 59 +- 10 min and 88 +- 4 min in dog and man, respectively. With the ECAT positron tomograph, high image-contrast ratios were found between heart and blood (dog 3.5/1, man 14/1), heart and lung (dog 9/1, man 20/1), and heart and liver (dog 15/1, man 10/1). The FDG was taken up rapidly by the myocardium without any significant tissue clearance over a 4-hr period. The FDG exhibited excellent imaging properties. Average counting rates of 12K, 20K, and 40K c/min-mCi injected are obtained in human subjects with high, medium, and low resolutions of the ECAT tomograph. Determination of glucose and FFA MR in vivo with EACT provides a method for investigation and assessment of changing aerobic and anaerobic metabolic rates in ischemic heart disease in man

  5. Variability of capillary blood glucose monitoring measured on home glucose monitoring devices

    OpenAIRE

    Kotwal, Narendra; Pandit, Aditi

    2012-01-01

    Self monitoring of blood glucose helps achieve glycemic goals. Glucometers must be accurate. Many variables affect blood glucose levels. Factors are analytical variables (intrinsic to glucometer and glucose strips) and pre analytical related to patients. Analytical variables depend on factors like shelf life, amount of blood and enzymatic reactions. Preanalytical variables include pH of blood, hypoxia, hypotension, hematocrit etc. CGMS has the potential to revolutionise diabetes care but accu...

  6. Measurement of Monosaccharides and Conversion of Glucose to Acetate in Anoxic Rice Field Soil

    OpenAIRE

    Chidthaisong, Amnat; Rosenstock, Bernd; Conrad, Ralf

    1999-01-01

    Degradation of glucose has been implicated in acetate production in rice field soil, but the abundance of glucose, the temporal change of glucose turnover, and the relationship between glucose and acetate catabolism are not well understood. We therefore measured the pool sizes of glucose and acetate in rice field soil and investigated the turnover of [U-14C]glucose and [2-14C]acetate. Acetate accumulated up to about 2 mM during days 5 to 10 after flooding of the soil. Subsequently, methanogen...

  7. Development of a fluorescent method for simultaneous measurement of glucose concentrations in interstitial fluid and blood

    International Nuclear Information System (INIS)

    Continuous blood glucose monitoring is of great clinical significance to patients with diabetes. One of the effective methods to monitor blood glucose is to measure glucose concentrations of interstitial fluid (ISF). However, a time-delay problem exists between ISF and blood glucose concentrations, which results in difficulty in indicating real-time blood glucose concentrations. Therefore, we developed a fluorescent method to verify the accuracy and reliability of simultaneous ISF and blood glucose measurement, especially incorporating it into research on the delay relationship between blood and ISF glucose changes. This method is based on a competitive reaction among borate polymer, alizarin and glucose. When glucose molecules combine with borate polymers in alizarin–borate polymer competitively, changes in fluorescence intensity demonstrate changes in glucose concentrations. By applying the measured results to the blood and ISF glucose delay relationship, we were able to calculate the time delay as an average of 2.16 ± 2.05 min for ISF glucose changes with reference to blood glucose concentrations. (paper)

  8. Development of a fluorescent method for simultaneous measurement of glucose concentrations in interstitial fluid and blood

    Science.gov (United States)

    Shi, Ting; Li, Dachao; Li, Guoqing; Chen, Limin; Lin, Yuan; Xu, Kexin; Lu, Luo

    2013-12-01

    Continuous blood glucose monitoring is of great clinical significance to patients with diabetes. One of the effective methods to monitor blood glucose is to measure glucose concentrations of interstitial fluid (ISF). However, a time-delay problem exists between ISF and blood glucose concentrations, which results in difficulty in indicating real-time blood glucose concentrations. Therefore, we developed a fluorescent method to verify the accuracy and reliability of simultaneous ISF and blood glucose measurement, especially incorporating it into research on the delay relationship between blood and ISF glucose changes. This method is based on a competitive reaction among borate polymer, alizarin and glucose. When glucose molecules combine with borate polymers in alizarin-borate polymer competitively, changes in fluorescence intensity demonstrate changes in glucose concentrations. By applying the measured results to the blood and ISF glucose delay relationship, we were able to calculate the time delay as an average of 2.16 ± 2.05 min for ISF glucose changes with reference to blood glucose concentrations.

  9. Relationship between fluctuations in glucose levels measured by continuous glucose monitoring and vascular endothelial dysfunction in type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Torimoto Keiichi

    2013-01-01

    Full Text Available Abstract Background Fluctuations in blood glucose level cause endothelial dysfunction and play a critical role in onset and/or progression of atherosclerosis. We hypothesized that fluctuation in blood glucose levels correlate with vascular endothelial dysfunction and that this relationship can be assessed using common bedside medical devices. Methods Fluctuations in blood glucose levels were measured over 24?hours by continuous glucose monitoring (CGM on admission day 2 in 57 patients with type 2 diabetes mellitus. The reactive hyperemia index (RHI, an index of vascular endothelial function, was measured using peripheral arterial tonometry (EndoPAT on admission day 3. Results The natural logarithmic-scaled RHI (L_RHI correlated with SD (r=?0.504; PPP=0.001 and percentage of time ?200?mg/dl (r=?0.292; P=0.028. In 12 patients with hypoglycemia, L_RHI also correlated with the percentage of time at hypoglycemia (r=?0.589; P=0.044. L_RHI did not correlate with HbA1c or fasting plasma glucose levels. Furthermore, L_RHI did not correlate with LDL cholesterol, HDL cholesterol, and triglyceride levels or with systolic and diastolic blood pressures. Finally, multivariate analysis identified MAGE as the only significant determinant of L_RHI. Conclusions Fluctuations in blood glucose levels play a significant role in vascular endothelial dysfunction in type 2 diabetes. Trial registration UMIN000007581

  10. Application of novel notched long-period fiber grating for glucose concentration measurement

    Science.gov (United States)

    Chang, Yuan-Cheng; Wu, Janw-Wei; Chiang, Chia-Chin

    2015-06-01

    In this paper, we propose using notched long-period fiber grating (NLPFG) fabricated by inductively coupled plasma etching for glucose concentration measurements. The experimental results show that the wavelengths varied linearly with differing glucose concentrations. The sensitivity of the NLPFG glucose concentration sensor is -0.147 nm/wt % from 0-40 wt % and the linearity (R2) is 0.938. The results demonstrate that the proposed NLPFG has potential for high-sensitivity glucose concentration sensor applications.

  11. Differential half-maximal effects of human insulin and its analogs for in situ glucose transport and protein synthesis in rat soleus muscle

    Science.gov (United States)

    Weinstein, Randi B.; Eleid, Noura; LeCesne, Catherine; Durando, Bianca; Crawford, Julie T.; Heffner, Michelle; Layton, Christle; O'Keefe, Matthew; Robinson, Jennifer; Rudinsky, Suzy; Henriksen, Erik J.; Tischler, Marc E.

    2002-01-01

    Analogs of human insulin have been used to discriminate between responses of metabolic and mitogenic (growth-related) pathways. This study compared the stimulatory effects of human insulin (HI) and 2 analogs (X2, B-Asp(9), B-Glu(27) and H2, A-His(8),B-His(4),B-Glu(10), B-His(27)) on glucose uptake and protein synthesis in rat soleus muscle in situ. Glucose uptake, estimated by intramuscular (IM) injection of 2-deoxy[1,2-3H]glucose with or without insulin, was maximally increased at 10(-6) mol/L for HI and X2 and 10(-7) mol/L for H2. HI had a larger effect (318%) than either X2 (156%) or H2 (124%). The half-maximal effect (ED(50)) values for HI, X2, and H2 were 3.3 x10(-8) mol/L, 1.7 x 10(-7) mol/L, and 1.6 x 10(-9) mol/L, respectively. Protein synthesis, estimated by protein incorporation of [(3)H]phenylalanine injected into muscles with or without insulin, was maximally increased at 10(-5) mol/L for HI and 10(-6) for X2 and H2. HI had a larger effect in stimulating protein synthesis (34%) than either X2 (25%) or H2 (19.8%). The ED(50) values for HI, X2, and H2 were 3.0 x 10(-7) mol/L, 3.2 x 10(-7) mol/L, and 1.0 x 10(-9) mol/L, respectively. The biological potency of each analog (ED(50)insulin/ED(50)analog) showed X2 to be less potent than HI for both glucose uptake (0.2) and protein synthesis (0.9), whereas H2 is more potent than HI with ratios of 20 and 300, respectively. These data suggest that this approach for studying insulin responsiveness in a single muscle in situ may be a useful tool for investigating insulin signaling in muscle in vivo. Copyright 2002, Elsevier Science (USA). All rights reserved.

  12. Measuring blood glucose in neonatal units: how does hemocue compare?

    OpenAIRE

    Deshpande, S A; Matthews, J N; Platt, M. P.

    1996-01-01

    Rapid and reliable determination of blood glucose concentration is essential during the neonatal period to prevent adverse neurodevelopmental outcome from hypoglycaemia. Despite their unreliability, reagent strip methods continue to be used extensively in neonatal nurseries due to their rapidity and convenience. Recently, a new portable laboratory standard technique has been introduced (HemoCue B-Glucose system) for whole blood glucose determination. It is particularly suitable for near-patie...

  13. Blood glucose measurement by glucometer in comparison with standard method in diagnosis of neonatal hypoglycemia.

    Science.gov (United States)

    Nayeri, Fatemeh; Shariat, Mamak; Mousavi Behbahani, Hamid Modarres; Dehghan, Padideh; Ebrahim, Bita

    2014-01-01

    Hypoglycemia is considered as a serious risk factor in neonates. In the majority of cases, it occurs with no clinical symptoms. Accordingly, early diagnosis is extremely imperative, which can also lead to less morbidity and mortality. The aim of this study was to assess the importance of screening blood glucose using glucometer (known as a quick and cost-effective diagnostic test) in comparison with laboratory method. A total of 219 neonates at risk of hypoglycemia were included in this study. Blood glucose was measured by glucometer and laboratory. In addition glucose level of capillary blood was measured by glucometer at the same time. Sensitivity and specificity of capillary blood glucose measurement by glucometer were 83.5%, 97.5% respectively (ppv=80%), (npv=98%). Capillary blood glucose measured by glucometer has an acceptable sensitivity and specificity in measurement of neonatal blood glucose. Therefore measurement by glucometer is recommended as a proper diagnostic test. PMID:25149886

  14. Blood glucose measurement by glucometer in comparison with standard method in diagnosis of neonatal hypoglycemia.

    Directory of Open Access Journals (Sweden)

    Fatemeh Nayeri

    2014-08-01

    Full Text Available Hypoglycemia is considered as a serious risk factor in neonates. In the majority of cases, it occurs with no clinical symptoms. Accordingly, early diagnosis is extremely imperative, which can also lead to less morbidity and mortality. The aim of this study was to assess the importance of screening blood glucose using glucometer (known as a quick and cost-effective diagnostic test in comparison with laboratory method. A total of 219 neonates at risk of hypoglycemia were included in this study. Blood glucose was measured by glucometer and laboratory. In addition glucose level of capillary blood was measured by glucometer at the same time. Sensitivity and specificity of capillary blood glucose measurement by glucometer were 83.5%, 97.5% respectively (ppv=80%, (npv=98%. Capillary blood glucose measured by glucometer has an acceptable sensitivity and specificity in measurement of neonatal blood glucose. Therefore measurement by glucometer is recommended as a proper diagnostic test.

  15. Glycolysis-induced discordance between glucose metabolic rates measured with radiolabeled fluorodeoxyglucose and glucose

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, R.F.; Lear, J.L. (UCLA School of Medicine (USA))

    1989-12-01

    We have developed an autoradiographic method for estimating the oxidative and glycolytic components of local CMRglc (LCMRglc), using sequentially administered ({sup 18}F)fluorodeoxyglucose (FDG) and ({sup 14}C)-6-glucose (GLC). FDG-6-phosphate accumulation is proportional to the rate of glucose phosphorylation, which occurs before the divergence of glycolytic (GMg) and oxidative (GMo) glucose metabolism and is therefore related to total cerebral glucose metabolism GMt: GMg + GMo = GMt. With oxidative metabolism, the {sup 14}C label of GLC is temporarily retained in Krebs cycle-related substrate pools. We hypothesize that with glycolytic metabolism, however, a significant fraction of the {sup 14}C label is lost from the brain via lactate production and efflux from the brain. Thus, cerebral GLC metabolite concentration may be more closely related to GMo than to GMt. If true, the glycolytic metabolic rate will be related to the difference between FDG- and GLC-derived LCMRglc. Thus far, we have studied normal awake rats, rats with limbic activation induced by kainic acid (KA), and rats visually stimulated with 16-Hz flashes. In KA-treated rats, significant discordance between FDG and GLC accumulation, which we attribute to glycolysis, occurred only in activated limbic structures. In visually stimulated rats, significant discordance occurred only in the optic tectum.

  16. Glycolysis-induced discordance between glucose metabolic rates measured with radiolabeled fluorodeoxyglucose and glucose.

    Science.gov (United States)

    Ackermann, R F; Lear, J L

    1989-12-01

    We have developed an autoradiographic method for estimating the oxidative and glycolytic components of local CMRglc (LCMRglc), using sequentially administered [18F]fluorodeoxyglucose (FDG) and [14C]-6-glucose (GLC). FDG-6-phosphate accumulation is proportional to the rate of glucose phosphorylation, which occurs before the divergence of glycolytic (GMg) and oxidative (GMo) glucose metabolism and is therefore related to total cerebral glucose metabolism GMt: GMg + GMo = GMt. With oxidative metabolism, the 14C label of GLC is temporarily retained in Krebs cycle-related substrate pools. We hypothesize that with glycolytic metabolism, however, a significant fraction of the 14C label is lost from the brain via lactate production and efflux from the brain. Thus, cerebral GLC metabolite concentration may be more closely related to GMo than to GMt. If true, the glycolytic metabolic rate will be related to the difference between FDG- and GLC-derived LCMRglc. Thus far, we have studied normal awake rats, rats with limbic activation induced by kainic acid (KA), and rats visually stimulated with 16-Hz flashes. In KA-treated rats, significant discordance between FDG and GLC accumulation, which we attribute to glycolysis, occurred only in activated limbic structures. In visually stimulated rats, significant discordance occurred only in the optic tectum. PMID:2584274

  17. Glycolysis-induced discordance between glucose metabolic rates measured with radiolabeled fluorodeoxyglucose and glucose

    International Nuclear Information System (INIS)

    We have developed an autoradiographic method for estimating the oxidative and glycolytic components of local CMRglc (LCMRglc), using sequentially administered [18F]fluorodeoxyglucose (FDG) and [14C]-6-glucose (GLC). FDG-6-phosphate accumulation is proportional to the rate of glucose phosphorylation, which occurs before the divergence of glycolytic (GMg) and oxidative (GMo) glucose metabolism and is therefore related to total cerebral glucose metabolism GMt: GMg + GMo = GMt. With oxidative metabolism, the 14C label of GLC is temporarily retained in Krebs cycle-related substrate pools. We hypothesize that with glycolytic metabolism, however, a significant fraction of the 14C label is lost from the brain via lactate production and efflux from the brain. Thus, cerebral GLC metabolite concentration may be more closely related to GMo than to GMt. If true, the glycolytic metabolic rate will be related to the difference between FDG- and GLC-derived LCMRglc. Thus far, we have studied normal awake rats, rats with limbic activation induced by kainic acid (KA), and rats visually stimulated with 16-Hz flashes. In KA-treated rats, significant discordance between FDG and GLC accumulation, which we attribute to glycolysis, occurred only in activated limbic structures. In visually stimulated rats, significant discordance occurred only in the optic tectum

  18. Glucose and glycerol concentrations and their tracer enrichment measurements using liquid chromatography tandem mass spectrometry

    DEFF Research Database (Denmark)

    BornØ, Andreas; Foged, Lene

    2014-01-01

    The present study describes a new liquid chromatography tandem mass spectrometry method for high-throughput quantification of glucose and glycerol in human plasma using stable isotopically labeled internal standards and is suitable for simultaneous measurements of glucose and glycerol enrichments in connection to in vivo metabolic studies investigating glucose turnover and lipolytic rate. Moreover, in order to keep up with this new fast analysis, simple derivatization procedures have been developed. Prior to analysis, glucose and glycerol were derivatized using benzoyl chloride in order to form benzoylated derivatives via new simplified fast procedures. For glucose, two internal standards were evaluated, [U-(13) C(6)]glucose and [U-(13) C(6), D(7)]glucose, and for glycerol, [U-(13) C(3), D(8)]glycerol was used. The method was validated by means of calibration curves, quality control samples, and plasma samples spiked with [6,6-D(2)]glucose, [U-(13) C(6)]glucose, and [1,1,2,3,3-D(5)]glycerol in order to test accuracy, precision, and recovery of the method. Moreover, post preparative and freeze-thaw sample stability were tested. The correlation of calibration curves for the glucose concentration were r(2) =?0.9998 for [U-(13) C(6)]glucose and r(2) =?0.9996 for [U-(13) C(6), D(7)]glucose, and r(2) =?0.9995 for the glycerol concentration. Interday accuracy for glucose using [U-(13) C(6)]glucose and glycerol determined in spiked plasma were respectively 103.5% and 106.0%, and the coefficients of variation were 2.0% and 9.7%, respectively. After derivatization, plasma samples were stable for at least 14?days. In conclusion, we have developed and validated a novel, accurate, and sensitive high-throughput liquid chromatography tandem mass spectrometry method for simultaneous determination of glucose and glycerol concentrations and enrichment of infused tracers most commonly used in human metabolic kinetic studies.

  19. Control module for fast measurement of analog signals

    International Nuclear Information System (INIS)

    A CAMAC module-an autonomous program source with the simple hardwire program which is applied in a system crate is described. It controls an analogue multiplexer and an analogue-to-digital converter through their front panels and writes the information into buffer memory module through CAMAC branch highway. The program source module contains registeres to write down the controlled modules addresses. Using this module provides the total time of measurement 6-10 times less as compared to program data gathering, a possibility to measure signals with maximum frequency in a spectrum 6-10 times higher. Simultaneously with measuring other program could be run in a computer

  20. Picosecond time measurement using ultra fast analog memories

    OpenAIRE

    Breton, D.(Laboratoire de l’Accélérateur Linéaire, IN2P3/CNRS et Université Paris-Sud 11, Centre Scientifique d’Orsay, F-91898, Orsay Cedex, France); Delagnes, E; Maalmi, J.

    2009-01-01

    The currently existing electronics dedicated to precise time measurement is mainly based on the use of constant fraction discriminators (CFD) associated with Time to Digital Converters (TDC). The constant fraction technique minimizes the time walk effect (dependency of timing on the pulse amplitude). Several attempts have been made to integrate CFD in multi-channel ASICs. But the time resolution measured on the most advanced one is of the order of 30 ps rms. Two main techniques are used for t...

  1. Measurement of the glucose concentration in human urine with optical refractometer

    Science.gov (United States)

    Wu, Rui-Yang; Hsu, Cheng-Chih; Meng, Ching-Tang; Cheng, Chih-Ching; Liao, Yu-Ching

    2015-07-01

    In this paper, a new type of human urine glucose measurement system is proposed. We measured the phase variation of human urine with/without glucose-urine mixture (to simulate diabetes mellitus). We were able to achieve high resolution with the proposed method. The relation curve between the phase difference and glucose concentration can be estimated, and the glucose concentration of a urine sample can be determined by using this relation curve. The proposed method showed that theoretical resolution is approximated of 1.47 mg/dl.

  2. The analogy between optical beam shifts and quantum weak measurements

    OpenAIRE

    Dennis, Mark R.; Götte, Jörg B

    2012-01-01

    We describe how the notion of optical beam shifts (including the spatial and angular Goos-H\\"anchen shift and Imbert-Federov shift) can be understood as a classical analogue of a quantum measurement of the polarization state of a paraxial beam by its transverse amplitude distribution. Under this scheme, complex quantum weak values are interpreted as spatial and angular shifts of polarized scalar components of the reflected beam. This connection leads us to predict an extra s...

  3. The analogy between optical beam shifts and quantum weak measurements

    International Nuclear Information System (INIS)

    We describe how the notion of optical beam shifts (including the spatial and angular Goos-Hänchen shift and Imbert-Federov shift) can be understood as a classical analogue of a quantum measurement of the polarization state of a paraxial beam by its transverse amplitude distribution. Under this scheme, complex quantum weak values are interpreted as spatial and angular shifts of polarized scalar components of the reflected beam. This connection leads us to predict an extra spatial shift for beams with a radially-varying phase dependance. (paper)

  4. Development of reconfigurable analog and digital circuits for plasma diagnostics measurement systems

    International Nuclear Information System (INIS)

    In long pulse discharge tokamak, a large number of diagnostic channels are being used to understand the complex behavior of plasma. Different diagnostics demand different types of analog and digital processing for plasma parameters measurement. This leads to variable requirements of signal processing for diagnostic measurement. For such types of requirements, we have developed hardware with reconfigurable electronic devices, which provide flexible solution for rapid development of measurement system. Here the analog processing is achieved by Field Programmable Analog Array (FPAA) integrated circuit while reconfigurable digital devices (CPLD/FPGA) achieve digital processing. FPAA's provide an ideal integrated platform for implementing low to medium complexity analog signal processing. With dynamic reconfigurability, the functionality of the FPAA can be reconfigured in-system by the designer or on the fly by a microprocessor. This feature is quite useful to manipulate the tuning or the construction of any part of the analog circuit without interrupting operation of the FPAA, thus maintaining system integrity. The hardware operation control logic circuits are configured in the reconfigurable digital devices (CPLD/FPGA) to control proper hardware functioning. These reconfigurable devices provide the design flexibility and save the component space on the board. It also provides the flexibility for various setting through software. The circuit controlling commands are either issued by computer/processor or generated by circuit itself. (author)

  5. Underestimation of glucose turnover measured with [6-3H]- and [6,6-2H]- but not [6-14C]glucose during hyperinsulinemia in humans

    International Nuclear Information System (INIS)

    Recent studies indicate that hydrogen-labeled glucose tracers underestimate glucose turnover in humans under conditions of high flux. The cause of this underestimation is unknown. To determine whether the error is time-, pool-, model-, or insulin-dependent, glucose turnover was measured simultaneously with [6-3H]-, [6,6-2H2]-, and [6-14C]glucose during a 7-h infusion of either insulin (1 mU.kg-1.min-1) or saline. During the insulin infusion, steady-state glucose turnover measured with both [6-3H]glucose (8.0 +/- 0.5 mg.kg-1.min-1) and [6,6-2H2]glucose (7.6 +/- 0.5 mg.kg-1.min-1) was lower (P less than .01) than either the glucose infusion rate required to maintain euglycemia (9.8 +/- 0.7 mg.kg-1.min-1) or glucose turnover determined with [6-14C]glucose and corrected for Cori cycle activity (9.8 +/- 0.7 mg.kg-1.min-1). Consequently negative glucose production rates (P less than .01) were obtained with either [6-3H]- or [6,6-2H2]- but not [6-14C]glucose. The difference between turnover estimated with [6-3H]glucose and actual glucose disposal (or 14C glucose flux) did not decrease with time and was not dependent on duration of isotope infusion. During saline infusion, estimates of glucose turnover were similar regardless of the glucose tracer used. High-performance liquid chromatography of the radioactive glucose tracer and plasma revealed the presence of a tritiated nonglucose contaminant. Although the contaminant represented only 1.5% of the radioactivity in the [6-3H]glucose infusate, its clearance was 10-fold less (P less than .001) than that of [6-3H]glucose. This resulted in accumulation in plasma, with the contaminant accounting for 16.6 +/- 2.09 and 10.8 +/- 0.9% of what customarily is assumed to be plasma glucose radioactivity during the insulin or saline infusion, respectively (P less than .01)

  6. Measure and category a survey of the analogies between topological and measure spaces

    CERN Document Server

    Oxtoby, John C

    1980-01-01

    In this edition, a set of Supplementary Notes and Remarks has been added at the end, grouped according to chapter. Some of these call attention to subsequent developments, others add further explanation or additional remarks. Most of the remarks are accompanied by a briefly indicated proof, which is sometimes different from the one given in the reference cited. The list of references has been expanded to include many recent contributions, but it is still not intended to be exhaustive. John C. Oxtoby Bryn Mawr, April 1980 Preface to the First Edition This book has two main themes: the Baire category theorem as a method for proving existence, and the "duality" between measure and category. The category method is illustrated by a variety of typical applications, and the analogy between measure and category is explored in all of its ramifications. To this end, the elements of metric topology are reviewed and the principal properties of Lebesgue measure are derived. It turns out that Lebesgue integration is not es...

  7. Measurement of Physiologic Glucose Levels Using Raman Spectroscopy in a Rabbit Aqueous Humor Model

    Science.gov (United States)

    Lambert, J.; Storrie-Lombardi, M.; Borchert, M.

    1998-01-01

    We have elecited a reliable glucose signature in mammalian physiological ranges using near infrared Raman laser excitation at 785 nm and multivariate analysis. In a recent series of experiments we measured glucose levels in an artificial aqueous humor in the range from 0.5 to 13X normal values.

  8. Clinically important factors influencing the diagnostic measurement of pleural fluid pH and glucose.

    OpenAIRE

    Rahman, NM; Mishra, EK; Davies, HE; Davies, RJ; Lee, YC

    2008-01-01

    RATIONALE: Accurate pleural fluid pH and glucose measurement is a key component in the diagnosis and management of patients with pleural effusion. Standardized methods of pleural fluid collection have not been defined. OBJECTIVES: To assess the effect of common clinical factors that may distort measurement accuracy of pleural fluid pH and glucose. METHODS: Ninety-two exudative pleural aspirates were collected in commercially available blood gas syringes. MEASUREMENTS AND MAIN RESULTS: Samples...

  9. Detection accuracy of three glucose meters estimated by capillary blood glucose measurements compared with venous blood evaluated by the diabetes unit of the Hospital Evangélico de Curitiba, Brazil

    Directory of Open Access Journals (Sweden)

    Camacho SL

    2012-05-01

    Full Text Available Mirnaluci Paulino Ribeiro Gama, Camile Fiorese Cruzeta, Ana Carolina Ossowski, Marina Rech Bay, Mariella Muller Michaelis, Stênio Lujan CamachoEndocrinology and Diabetes Service, Hospital Universitário Evangélico de Curitiba, BrazilObjective: To compare capillary blood glucose measurements between three different glucose meters and with the serum glucose values of inpatients at the diabetes unit of Hospital Universitário Evangélico de Curitiba, Brazil.Materials and methods: A total of 132 non-intensive care unit patients admitted for medical and surgical pathologies were evaluated. All patients reported a previous diagnosis of diabetes mellitus, were under 60 years of age, had no hematocrit alterations, remained hemodynamically stable during the time of data collection, and were given no ascorbic acid, acetaminophen, dopamine, or mannitol during follow-up. Capillary and serum blood glucose samples were collected simultaneously by finger-stick and venipuncture 2 hours after lunch, by the same observer, who was blinded to the serum glucose results. First, between July and November 2009, capillary glucose levels were measured using the blood glucose meters OneTouch SureStep® and MediSense Optium®. Between November 2009 and February 2010, capillary blood glucose levels were measured on the glucose meters OneTouch SureStep and Optium Xceed®. The capillary glucose readings were analyzed between meters and also in relation to the serum blood glucose values by the t-test for paired samples and the Mood two-sample test.Results: The patients’ mean age was 50.45 years. The blood glucose means obtained using the meters OneTouch SureStep, MediSense Optium, and Optium Xceed were, respectively, 183.87 mg/dL, 178.49 mg/dL, and 192.73 mg/dL, and the mean for the serum glucose values was 174.58 mg/dL. A significant difference was found between the capillary measurements taken by the glucose meters and the serum glucose measurements (P < 0.05, and no significant interdevice difference was found. After stratification of the serum blood glucose values into two groups, below and above 180 mg/dL, the variance found for the glucose meter OneTouch SureStep was statistically greater (P = 0.03 in relation to the serum glucose levels above 180 mg/dL, which was not the case with the glucose meters MediSense Optium (P = 0.06 and Optium Xceed (P = 0.12. The percentage of capillary blood glucose values showing a variation of less than 20% compared with serum values was 64.94% for OneTouch SureStep, 47.83% for Medisense Optium, and 51.61% for Optium Xceed, when serum glucose was greater than 75 mg/dL.Conclusion: The glucose meters tested showed an adequate interdevice correlation in their capillary glucose readings, in addition to correlating with the serum glucose values (ie, if a blood glucose reading is high or low in one test, it is likely to be respectively high or low in another. The means for the capillary blood glucose readings, however, were significantly different from the mean serum glucose. When serum glucose was above 180 mg/dL, there was a greater variance in the capillary measurements on the glucose meter OneTouch SureStep, with less correlation with the serum blood glucose (P < 0.05, which did not occur significantly with the two other glucose meters. On the other hand, OneTouch SureStep had the highest accuracy in relation to serum glucose when the whole sample of serum glucose values above 75 mg/dL was analyzed, considering a variation of less than 20% in the measurements. The three glucose meters provide readings that correlate with the serum glucose values of hospitalized patients. However, one should bear in mind that capillary measurements quite often show more than a 20% variation in relation to serum glucose values, and caution should be exercised in interpreting the readings when serum glucose levels are elevated.Keywords: capillary blood glucose, serum glucose, glucose meters, hospitalized patients

  10. Measurement of deuterium-labeled glucose flux in newborn infants by the continuous isotope infusion technique

    International Nuclear Information System (INIS)

    Although hypoglycemia is a frequent neonatal problem, direct estimates of glucose turnover in newborn infants have not been possible before the advent of practical, stable isotope microtechniques. Using the well-established constant isotopic infusion procedure, glucose flux has been measured in newborn infants for the first time with the metabolically non-recycling tracer, glucose-6,6-d2. Nineteen infants from 650 to 4330 grams (25 to 44 weeks gestation) were studied at various times during the first week of postnatal life. 100 to 200 microliter capillary blood samples, obtained at appropriate intervals during the course of a 150 to 240 minute infusion of dideuterioglucose, were processed by rapid ion exchange purification and the glucose converted to the 6-0-acetyl-1,2 : 3,5-di-O-(n-butane-boronyl)-?-D-glucofuranose derivative for subsequent measurement of isotopic enrichment by combined GC-MS with selected ion recording using an AVA:Voltage Sweeping circuit. Glucose flux rates were calculated by steady-state equations, where appropriate, or by non steady-state approximations when blood glucose concentration and/or glucose isotopic enrichment changed during the course of the investigation. Total glucose flux ranged from 3 to 43 mg/min (3.7 to 11.1 mg/kg.min) and was directly correlated with body weight, estimated brain weight, and average blood sugar concentration during the course of the study. These data agree closely with previous indirect estimates of glucose metabolism in the newborn period and represent the first direct measurements of new glucose production and utilization in the human neonate

  11. Measurements of serum glucose using the luciferin/Luciferase system and a liquid scintillation spectrometer

    International Nuclear Information System (INIS)

    A single-step assay for serum glucose measurements is described. The assay is based on the phosphorylation of D-glucose by glucokinase and the measurement of ATP consumption by firefly luciferase. The luminescence is recorded in an ordinary liquid scintillation spectrometer. The use of stable reagents and a stable final signal (light emission) makes it possible to analyze a large number of samples in each assay run. The assay is of particular value when repeated serum glucose determinations are performed on samples from small laboratory animals

  12. Adaptive Blood Glucose Monitoring and Insulin Measurement Devices for Visually Impaired Persons.

    Science.gov (United States)

    Petzinger, R. A.

    1993-01-01

    This article describes devices that people with visual impairments and diabetes can use to monitor blood glucose levels and measure insulin. A table lists devices, their manufacturers (including address and telephone number), and comments about the devices. (DB)

  13. Design of a Mechanical-Tunable Filter Spectrometer for Noninvasive Glucose Measurement

    Science.gov (United States)

    Saptari, Vidi; Youcef-Toumi, Kamal

    2004-05-01

    The development of an accurate and reliable noninvasive near-infrared (NIR) glucose sensor hinges on the success in addressing the sensitivity and the specificity problems associated with the weak glucose signals and the overlapping NIR spectra. Spectroscopic hardware parameters most relevant to noninvasive blood glucose measurement are discussed, which include the optical throughput, integration time, spectral range, and the spectral resolution. We propose a unique spectroscopic system using a continuously rotating interference filter, which produces a signal-to-noise ratio of the order of 10^5 and is estimated to be the minimum required for successful in vivo glucose sensing. Using a classical least-squares algorithm and a spectral range between 2180 and 2312 nm, we extracted clinically relevant glucose concentrations in multicomponent solutions containing bovine serum albumin, triacetin, lactate, and urea.

  14. Accuracy of Continuous Glucose Monitoring Measurements in Normo-Glycemic Individuals

    DEFF Research Database (Denmark)

    Akintola, Abimbola A; Noordam, Raymond

    2015-01-01

    BACKGROUND: The validity of continuous glucose monitoring (CGM) is well established in diabetic patients. CGM is also increasingly used for research purposes in normo-glycemic individuals, but the CGM validity in such individuals is unknown. We studied the accuracy of CGM measurements in normo-glycemic individuals by comparing CGM-derived versus venous blood-derived glucose levels and measures of glycemia and glycemic variability. METHODS: In 34 healthy participants (mean age 65.7 years), glucose was simultaneously measured every 10 minutes, via both an Enlite® CGM sensor, and in venous blood sampled over a 24-hour period. Validity of CGM-derived individual glucose measurements, calculated measures of glycemia over daytime (09:00h-23:00h) and nighttime (23:00h-09:00h), and calculated measures of glycemic variability (e.g. 24h standard deviation [SD]) were assessed by Pearson correlation coefficients, mean absolute relative difference (MARD) and paired t-tests. RESULTS: The median correlation coefficient between CGM and venous glucose measurements per participant was 0.68 (interquartile range: 0.40-0.78), and the MARD was 17.6% (SD = 17%). Compared with venous sampling, the calculated measure of glycemia during daytime was 0.22 mmol/L higher when derived from CGM, but no difference was observed during nighttime. Most measures of glycemic variability were lower with CGM than with venous blood sampling (e.g., 24h SD: 1.07 with CGM and 1.26 with venous blood; p-value = 0.004). CONCLUSION: In normo-glycemic individuals, CGM-derived glucose measurements had good agreement with venous glucose levels. However, the measure of glycemia was higher during the day and most measures of glycemic variability were lower when derived from CGM.

  15. An Analog-Digital Mixed Measurement Method of Inductive Proximity Sensor

    OpenAIRE

    Yi-Xin Guo; Zhi-Biao Shao; Ting Li

    2015-01-01

    Inductive proximity sensors (IPSs) are widely used in position detection given their unique advantages. To address the problem of temperature drift, this paper presents an analog-digital mixed measurement method based on the two-dimensional look-up table. The inductance and resistance components can be separated by processing the measurement data, thus reducing temperature drift and generating quantitative outputs. This study establishes and implements a two-dimensional look-up table that red...

  16. The measurement of the nigrostriatal dopaminergic function and glucose metabolism in patients with movement disorders

    International Nuclear Information System (INIS)

    The nigrostriatal dopaminergic function and glucose metabolism were evaluated in 34 patients with various movement disorders by using positron emission tomography with 18F-Dopa and 18F-FDG respectively. The 18F-Dopa uptake in the striatum (the caudate head and the putamen) decreased in patients with Parkinson's disease but was relatively unaffected in the caudate. The cerebral glucose metabolism was normal in patients with Parkinson's disease. The 18F-Dopa uptake in the striatum also decreased in cases of atypical parkinsonism and in cases of progressive supranuclear palsy, but there was no difference in the uptake between the caudate and the putamen. The glucose metabolism decreased in the cerebral hemisphere including the striatum; this finding was also different from those of Parkinson's disease. A normal 18F-Dopa uptake in the striatum with a markedly decreased striatal glucose metabolism and a mildly decreased cortical glucose metabolism was observed in cases of Huntington's disease and Wilson's disease. The 18F-Dopa uptake in the striatum increased and the glucose metabolism was normal in cases of idiopathic dystonia. Various patterns of 18F-Dopa uptake and glucose metabolism were thus observed in the various movement disorders. These results suggest that the measurements of the 18F-Dopa uptake and the cerebral glucose metabolism would be useful for the evaluation of the striatal function in various movement disorders. (author)

  17. An optofluidic system with volume measurement and surface plasmon resonance sensor for continuous glucose monitoring.

    Science.gov (United States)

    Li, Dachao; Lu, Bingyu; Zhu, Rui; Yu, Haixia; Xu, Kexin

    2016-01-01

    The traditional technology of glucose monitoring is painful and invasive because of the frequent blood collection. Nowadays, the enzyme electrode sensor is mainly used for continuous glucose monitoring in clinic, but it has inherent disadvantages of significant signal drift of current due to bioelectricity in body and the missing of hypoglycemia resulting from the irreversible consumption of glucose at the process of enzyme catalytic reaction. Interstitial fluid (ISF) transdermal extraction can be nearly unsensible which effectively reduces the pain caused by invasive detection so that it may provide a new way to monitor glucose. MEMS technology has been used to produce devices for transdermal ISF extraction, but there is a lack of on-chip ISF volume measurement capabilities, which are required to compensate skin permeability variations. This paper presents a lab-on-a-chip system for ISF transdermal extraction, ISF volume measurement, and optical glucose sensing towards the application of continuous glucose monitoring. The device significantly incorporates a MEMS volume sensor, which measures extracted ISF volume via conductance monitoring, and integrates a fiber-optic surface plasmon resonance sensor to measure glucose concentration in microchannel. The fiber-based technique provides an excellent approach to overcome the above two drawbacks of the enzyme electrode based glucose sensing. Six different volumes were tested, and the standard deviation of every sample is less than 0.05??l, The resonance wavelength moves from 549.081?nm to 592.914?nm while the concentration ranges from 0 to 200?mg/dl. The feasibility of the single-chip device for accurate and continuous monitoring of subcutaneous ISF glucose concentrations is verified. PMID:26958100

  18. Quantitative measurement of glucose utilization in dog brain using positron emission tomogram and 18FDG

    International Nuclear Information System (INIS)

    Recent development of positron emission tomography and fluorine-18 labeled deoxy-glucose has enabled us to observe in vivo metabolism of glucose. For the application to human study, the method originally developed by Sokoloff et al. in rat brain was performed in dog brain using ECAT II in order to measure cerebral metabolic rate of glucose. Cross calibration between ECAT II and well counter was performed using phantom imaging and positron emmiter (Ga-68). Plasma 18-FDG was measured in well counter and calibrated. Cerebral metabolic rate of glucose (mg/100g brain.min) was calculated using ECAT images of 18-FDG and integrated activity of plasma 18-FDG from injection time (zero) to imaging time (t). 14.5mg/100g brain.min and 14.2mg/100g brain.min were obtained in frontal cortex and occipital cortex in anesthetized dog. (author)

  19. Wavelength-modulated differential laser photothermal radiometry for blood glucose measurements

    International Nuclear Information System (INIS)

    A Wavelength-Modulated Differential Laser Photothermal Radiometer (WM-DPTR) technique was used for non-invasive blood glucose monitoring in the mid-IR range, where the prominent absorption peak is glucose specific and isolated from other interfering peaks in human blood. The WM-DPTR method consists of the out-of-phase modulated excitation at two discrete wavelengths 9.5 ?m and 10.4 ?m (near the peak and the baseline of glucose absorption), generated from two quantum cascade lasers (QCL) and the differential emission detection through a thermal-wave upconversion process via a HgCdZnTe (MCZT) detector (2-5 ?m). The differential method suppresses the background signal and reduces source-detection interference, thus enhancing glucose detection sensitivity. The results from aqueous glucose phantom (0-440 mg/dl) measurements demonstrate that both amplitude and phase of the WM-DPTR signal can be used for glucose detection. The dynamic range and the sensitivity of the glucose detection are influenced greatly by the laser intensity ratio and modulation frequency. The optimal intensity ratio for high sensitivity is ?1. Other laser intensity ratios increase dynamic range but reduce sensitivity. Sensitivity increases with frequency.

  20. Comparison of protocols for measuring and calculating postmortem submersion intervals for human analogs in fresh water.

    Science.gov (United States)

    Humphreys, Michael K; Panacek, Edward; Green, William; Albers, Elizabeth

    2013-03-01

    Protocols for determining postmortem submersion interval (PMSI) have long been problematic for forensic investigators due to the wide variety of factors affecting the rate of decomposition of submerged carrion. Likewise, it has been equally problematic for researchers to develop standardized experimental protocols to monitor underwater decomposition without artificially affecting the decomposition rate. This study compares two experimental protocols: (i) underwater in situ evaluation with photographic documentation utilizing the Heaton et al. total aquatic decomposition (TAD) score and (ii) weighing the carrion before and after submersion. Complete forensic necropsies were performed as a control. Perinatal piglets were used as human analogs. The results of this study indicate that in order to objectively measure decomposition over time, the human analog should be examined at depth using the TAD scoring system rather than utilizing a carrion weight evaluation. The acquired TAD score can be used to calculate an approximate PMSI. PMID:23278272

  1. The Analog Revolution and Its On-Going Role in Modern Analytical Measurements.

    Science.gov (United States)

    Enke, Christie G

    2015-12-15

    The electronic revolution in analytical instrumentation began when we first exceeded the two-digit resolution of panel meters and chart recorders and then took the first steps into automated control. It started with the first uses of operational amplifiers (op amps) in the analog domain 20 years before the digital computer entered the analytical lab. Their application greatly increased both accuracy and precision in chemical measurement and they provided an elegant means for the electronic control of experimental quantities. Later, laboratory and personal computers provided an unlimited readout resolution and enabled programmable control of instrument parameters as well as storage and computation of acquired data. However, digital computers did not replace the op amp's critical role of converting the analog sensor's output to a robust and accurate voltage. Rather it added a new role: converting that voltage into a number. These analog operations are generally the limiting portions of our computerized instrumentation systems. Operational amplifier performance in gain, input current and resistance, offset voltage, and rise time have improved by a remarkable 3-4 orders of magnitude since their first implementations. Each 10-fold improvement has opened the doors for the development of new techniques in all areas of chemical analysis. Along with some interesting history, the multiple roles op amps play in modern instrumentation are described along with a number of examples of new areas of analysis that have been enabled by their improvements. PMID:26629976

  2. Measurement of the incretin hormones : glucagon-like peptide-1 and glucose-dependent insulinotropic peptide

    DEFF Research Database (Denmark)

    Kuhre, Rune Ehrenreich; Wewer Albrechtsen, Nicolai Jacob

    2015-01-01

    The two incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), are secreted from the gastrointestinal tract in response to meals and contribute to the regulation of glucose homeostasis by increasing insulin secretion. Assessment of plasma concentrations of GLP-1 and GIP is often an important endpoint in both clinical and preclinical studies and, therefore, accurate measurement of these hormones is important. Here, we provide an overview of current approaches for the measurement of the incretin hormones, with particular focus on immunological methods.

  3. Measurement of the Incretin Hormones: Glucagon-Like Peptide-1 and Glucose-Dependent Insulinotropic Peptide

    DEFF Research Database (Denmark)

    Kuhre, Rune Ehrenreich; Wewer Albrechtsen, Nicolai Jacob

    2015-01-01

    The two incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), are secreted from the gastrointestinal tract in response to meals and contribute to the regulation of glucose homeostasis by increasing insulin secretion. Assessment of plasma concentrations of GLP-1 and GIP is often an important endpoint in both clinical and preclinical studies and, therefore, accurate measurement of these hormones is important. Here, we provide an overview of current approaches for the measurement of the incretin hormones, with particular focus on immunological methods.

  4. Glucose metabolism in chronic diabetic foot ulcers measured in vivo using microdialysis

    DEFF Research Database (Denmark)

    Simonsen, L; Holstein, P; Larsen, K; Bülow, J

    1998-01-01

    Ten subjects with diabetes mellitus and unilateral chronic foot ulcer were investigated. Local tissue concentrations of glucose and lactate were measured using the microdialysis method at a distance of 0.5-1 cm from the edge of the ulcer and in normal skin in the contralateral foot. Subcutaneous...... blood flow in the area investigated was measured using the 133Xewashout technique. The interstitial glucose concentration in the ulcer was found to be lower than in intact skin (8.0 +/- 1.0 mmol l-1 vs. 8.5 +/- 1.1 mmol l-1) (P <0.02), and the interstitial lactate concentration was higher in the ulcer...

  5. Low power analog readout front-end electronics for time and energy measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kleczek, R., E-mail: rafal.kleczek@agh.edu.pl; Grybos, P.; Szczygiel, R.

    2014-06-01

    We report on the design and measurements of an analog front-end readout electronics dedicated for silicon microstrip detectors with relatively large capacitance of the order of tens pF for time and energy measurements of incoming pulses. The front-end readout electronics is required to process input pulses with an average rate of 150 kHz/channel with low both power consumption and noise at the same time. In the presented solution the single channel is built of two different parallel processing paths: fast and slow. The fast path includes the fast CR–RC shaper with the peaking time t{sub p}=40 ns and is optimized to determine the input charge arrival time. The slow path, which consists of the slow CR–(RC){sup 2} shaper with the peaking time t{sub p}=80 ns, is dedicated for low noise accurate energy measurement. The analog front-end electronics was implemented in UMC 180 nm CMOS technology as a prototype ASIC AFE. The AFE chip contains 8 channels with the size of 58 ?m×1150 ?m each. It has low power dissipation P{sub diss}=3.1 mW per single channel. The article presents the details of the front-end architecture and the measurement results.

  6. Precision analog signal processor for beam position measurements in electron storage rings

    Science.gov (United States)

    Hinkson, J. A.; Unser, K. B.

    1995-05-01

    Beam position monitors (BPM) in electron and positron storage rings have evolved from simple systems composed of beam pickups, coaxial cables, multiplexing relays, and a single receiver (usually a analyzer) into very complex and costly systems of multiple receivers and processors. The older may have taken minutes to measure the circulating beam closed orbit. Today instrumentation designers are required to provide high-speed measurements of the beam orbit, often at the ring revolution frequency. In addition the instruments must have very high accuracy and resolution. A BPM has been developed for the Advanced Light Source (ALS) in Berkeley which features high resolution and relatively low cost. The instrument has a single purpose; to measure position of a stable stored beam. Because the pickup signals are multiplexed into a single receiver, and due to its narrow bandwidth, the receiver is not intended for single-turn studies. The receiver delivers normalized measurements of X and Y position entirely by analog means at nominally 1 V/mm. (No computers are involved; No software is required.) Bergoz, a French company specializing in precision beam instrumentation, integrated the ALS design in their new BPM analog signal processor module. Performance comparisons were made on the ALS. In this paper we report on the architecture and performance of the ALS prototype BPM.

  7. An Analog-Digital Mixed Measurement Method of Inductive Proximity Sensor.

    Science.gov (United States)

    Guo, Yi-Xin; Shao, Zhi-Biao; Li, Ting

    2015-01-01

    Inductive proximity sensors (IPSs) are widely used in position detection given their unique advantages. To address the problem of temperature drift, this paper presents an analog-digital mixed measurement method based on the two-dimensional look-up table. The inductance and resistance components can be separated by processing the measurement data, thus reducing temperature drift and generating quantitative outputs. This study establishes and implements a two-dimensional look-up table that reduces the online computational complexity through structural modeling and by conducting an IPS operating principle analysis. This table is effectively compressed by considering the distribution characteristics of the sample data, thus simplifying the processing circuit. Moreover, power consumption is reduced. A real-time, built-in self-test (BIST) function is also designed and achieved by analyzing abnormal sample data. Experiment results show that the proposed method obtains the advantages of both analog and digital measurements, which are stable, reliable, and taken in real time, without the use of floating-point arithmetic and process-control-based components. The quantitative output of displacement measurement accelerates and stabilizes the system control and detection process. The method is particularly suitable for meeting the high-performance requirements of the aviation and aerospace fields. PMID:26729118

  8. Precision analog signal processor for beam position measurements in electron storage rings

    International Nuclear Information System (INIS)

    Beam position monitors (BPM) in electron and positron storage rings have evolved from simple systems composed of beam pickups, coaxial cables, multiplexing relays, and a single receiver (usually a analyzer) into very complex and costly systems of multiple receivers and processors. The older may have taken minutes to measure the circulating beam closed orbit. Today instrumentation designers are required to provide high-speed measurements of the beam orbit, often at the ring revolution frequency. In addition the instruments must have very high accuracy and resolution. A BPM has been developed for the Advanced Light Source (ALS) in Berkeley which features high resolution and relatively low cost. The instrument has a single purpose; to measure position of a stable stored beam. Because the pickup signals are multiplexed into a single receiver, and due to its narrow bandwidth, the receiver is not intended for single-turn studies. The receiver delivers normalized measurements of X and Y posit ion entirely by analog means at nominally 1 V/mm. No computers are involved. No software is required. Bergoz, a French company specializing in precision beam instrumentation, integrated the ALS design m their new BPM analog signal processor module. Performance comparisons were made on the ALS. In this paper we report on the architecture and performance of the ALS prototype BPM

  9. Low power analog readout front-end electronics for time and energy measurements

    International Nuclear Information System (INIS)

    We report on the design and measurements of an analog front-end readout electronics dedicated for silicon microstrip detectors with relatively large capacitance of the order of tens pF for time and energy measurements of incoming pulses. The front-end readout electronics is required to process input pulses with an average rate of 150 kHz/channel with low both power consumption and noise at the same time. In the presented solution the single channel is built of two different parallel processing paths: fast and slow. The fast path includes the fast CR–RC shaper with the peaking time tp=40 ns and is optimized to determine the input charge arrival time. The slow path, which consists of the slow CR–(RC)2 shaper with the peaking time tp=80 ns, is dedicated for low noise accurate energy measurement. The analog front-end electronics was implemented in UMC 180 nm CMOS technology as a prototype ASIC AFE. The AFE chip contains 8 channels with the size of 58 μm×1150 μm each. It has low power dissipation Pdiss=3.1 mW per single channel. The article presents the details of the front-end architecture and the measurement results

  10. An Analog-Digital Mixed Measurement Method of Inductive Proximity Sensor

    Directory of Open Access Journals (Sweden)

    Yi-Xin Guo

    2015-12-01

    Full Text Available Inductive proximity sensors (IPSs are widely used in position detection given their unique advantages. To address the problem of temperature drift, this paper presents an analog-digital mixed measurement method based on the two-dimensional look-up table. The inductance and resistance components can be separated by processing the measurement data, thus reducing temperature drift and generating quantitative outputs. This study establishes and implements a two-dimensional look-up table that reduces the online computational complexity through structural modeling and by conducting an IPS operating principle analysis. This table is effectively compressed by considering the distribution characteristics of the sample data, thus simplifying the processing circuit. Moreover, power consumption is reduced. A real-time, built-in self-test (BIST function is also designed and achieved by analyzing abnormal sample data. Experiment results show that the proposed method obtains the advantages of both analog and digital measurements, which are stable, reliable, and taken in real time, without the use of floating-point arithmetic and process-control-based components. The quantitative output of displacement measurement accelerates and stabilizes the system control and detection process. The method is particularly suitable for meeting the high-performance requirements of the aviation and aerospace fields.

  11. Evaluating the blood glucose measured via glucometry in diagnosis of hypoglycemia in neonates

    Directory of Open Access Journals (Sweden)

    Shamsollah Nooripoor

    2012-06-01

    Full Text Available Introduction: Hypoglycemia is one of the most prevalent problems seen in neonates and can lead toirreversible brain damage if not to be diagnosed in time. Today, the blood glucose is mostly checked bylaboratory methods that have a significant delay and can result in many adverse effects such as vesselrupture. The goal of this study was to evaluate the value of the glucometry device in diagnosis ofhypoglycemia in neonates.Materials and Methods: This study has been conducted over 156 hospitalized neonates in Amir almomenin Hospital, Semnan, Iran. The blood glucose in all cases has been simultaneously measured by bothlaboratory methods (glucose oxidase as the golden standard and glucometer. These measurements alongwith the relevant data for neonatal risk factors were recorded in the checklist. The blood glucosemeasurements of less than or equal 35 mg/dL in first two hours after birth, less than or equal 40mg/dL in 3to 24 hours after birth, less than or equal 45 mg/dL in more than 24 hours after birth are considered ashypoglycemic.Results: 58 neonates (37.2% were hypoglycemic.The measurement of blood glucose levels viaglucometer for hypoglycemia detection had a high precision (Area under curve = 0.941, Standard error=0.018, P= 0.0001. The optimum cut-off point yielded to equivalent of 51mg/dL. So that for fasting bloodglucose of less than or equal 51mg/dL, sensitivity, specificity, positive, and negative predictive values were,respectively, 94.7%, 81.6%, 75.3%, and 96.4%.Conclusion: Findings show that, blood glucose levels measured by glucometry have goodaccuracy for diagnosis of hypoglycemia in newborns. Thus, it is recommended that in case ofscreening and frequent need of monitoring neonatal blood glucose, this device be used as asuitable replacement of laboratory methods

  12. FASTBUS recording System for measurement of time intervals and analog signals for the Sphere spectrometer

    International Nuclear Information System (INIS)

    A FASTBUS recording system used to measure time intervals and fast analog signal at the SPHERE spectrometer is described. The system is based on a 16-channel 8-bit ADC FASTBUS module, a 16-channel 16-bit TDC FASTBUS module and a FIORI interface module connected to CAMAC registers realized data transfer between a FASTBUS segment and a CAMAC dataway. The operation of the system is controlled by an Electronika-60 microcomputer connected to a CAMAC crate controller. The software used in the system provides communication between the FASTBUS segment and the computer, module testing, data acquisition and processing, and result presentation

  13. Harmonical oscillator and electro-mechanical analogy: an interdiscinary experiment to high precision mass variation measurements

    Scientific Electronic Library Online (English)

    Ailton M., Watanabe; Adriano dos, Santos; Paulo R., Bueno.

    Full Text Available De forma geral, os cursos de física clássica oferecidos nas universidades carecem de exemplos de aplicações nas áreas de química e biologia, o que por vezes desmotivam os alunos de graduação destas áreas a estudarem os conceitos físicos desenvolvidos em sala de aula. Neste texto, a analogia entre os [...] osciladores elétrico e mecânico é explorada visando possívies aplicações em química e biologia, mostrando-se de grande valia devido ao seu uso em técnicas de medição de variação de massa com alta precisão, tanto de forma direta como indireta. Estas técnicas são conhecidas como técnicas eletrogravimétricas e são de especial importância em aplicações que envolvem biossensores. Desta forma, o texto explora o estudo da analogia eletromecânica de forma interdisciplinar envolvendo as áreas de física, química e biologia. Baseado nessa analogia é proposto um experimento que permite a sua aplicação em diferentes níveis conceituais dessas disciplinas, tanto em abordagem básica como mais profunda. Abstract in english In general, the traditional Physics courses needs examples of the aplications of the Physics concepts in other areas such as Chemistry and Biology. This lacks tend to demotivate Chemistry and Biology students regarding to deal with Physical concepts developed in classroom. In this work, the analogy [...] among mechanic and electric oscillators is investigated to be applied in Chemistry and Biology areas, showing to be valuable due to its aplication in techniques that aims to measure mass variation with high precision. This measure could be made in a direct or indirect way. These techniques are known as electrogravimetric techniques and they are important in biosensor aplications. Thus, this paper explores the electromechanic analogy in an interdisciplinary way involving areas like Physics, Chemistry and Biology. Based on this analogy, it is proposed an experiment that can be applied in different ways, i.e. by an basic approach or more deeper, depending on the students specific formation, in other words, Physics, Chemistry or Biology.

  14. Classification of diabetes and measurement of blood glucose concentration noninvasively using near infrared spectroscopy

    Science.gov (United States)

    Li, Zhe; Li, Gang; Yan, Wen-Juan; Lin, Ling

    2014-11-01

    Developing noninvasive blood glucose monitoring method is an to immense need to alleviate the pain and suffering of diabetics associated with the frequent pricking of skin for taking blood sample. A hybrid algorithm for multivariate calibration is proposed to improve the prediction performance of classification of diabetes and measurement of blood glucose concentration by near infrared (NIR) spectroscopy noninvasively. The algorithm is based on wavelet prism modified uninformative variable elimination approach (WP-mUVE) combined with least squares support vector machine (LSSVM), named as WP-mUVE-LSSVM. The method is successfully applied to diabetic classification experiment (in vivo) and blood glucose concentration measurement experiment (in vivo) respectively. Human tongue is selected as the measuring site in this study. To evaluate effectiveness of pretreatment method and quality of calibration models, several usually used pretreatment methods and kernel functions of LSSVM are introduced comparing with our method. Higher quality data is obtained by our pretreatment method owing to the elimination of varying background and noise of spectra data simultaneously. Better prediction accuracy and adaptability are obtained by LSSVM model with radial basis kernel function. The results indicate that WP-mUVE-LSSVM holds promise for the classification of diabetes and measurement of blood glucose concentration noninvasively based on human tongue using NIR spectroscopy.

  15. Glucose and glycerol concentrations and their tracer enrichment measurements using liquid chromatography tandem mass spectrometry

    DEFF Research Database (Denmark)

    Bornø, Andreas; Foged, Lene; van Hall, Gerrit

    2014-01-01

    The present study describes a new liquid chromatography tandem mass spectrometry method for high-throughput quantification of glucose and glycerol in human plasma using stable isotopically labeled internal standards and is suitable for simultaneous measurements of glucose and glycerol enrichments...... coefficients of variation were 2.0% and 9.7%, respectively. After derivatization, plasma samples were stable for at least 14?days. In conclusion, we have developed and validated a novel, accurate, and sensitive high-throughput liquid chromatography tandem mass spectrometry method for simultaneous determination...

  16. [Achievement of the noninvasive measurement for human blood glucose with NIR diffusion reflectance spectrum method].

    Science.gov (United States)

    Zhang, Hong-yan; Ding, Dong; Song, Li-qiang; Gu, Lin-na; Yang, Peng; Tang, Yu-guo

    2005-06-01

    The noninvasive measurement of human blood glucose was achieved with NIR diffusion reflectance spectrum method. The thumb fingertip NIR diffusion reflectance spectra of six different age healthy volunteers were collected using Nexus-870 and its NIR fiber port smart accessory. The test was implemented with changing the blood glucose concentration for the limosis and satiation of every volunteer. The calibration model was set up using PLS method with the smoothing, baseline correction and first derivatives pretreatment spectrum in the 7500-8500 cm(-1) region for single volunteer, the same age combination and that of different age. When the spectrum was obtained, the actual blood glucose value of every spectrun sample was demarcated using ultraviolet spectrophotometer. The correlation between the calibration value and true value for single volunteer is better than that for the combination of volunteers, the correlative coefficients are all over 0.90471, RMSECs are all less than 0.171. PMID:16201363

  17. Demonstration of remote optical measurement configuration that correlates to glucose concentration in blood.

    Science.gov (United States)

    Beiderman, Yevgeny; Blumenberg, Raz; Rabani, Nir; Teicher, Mina; Garcia, Javier; Mico, Vicente; Zalevsky, Zeev

    2011-01-01

    An optical approach allowing the extraction and the separation of remote vibration sources has recently been proposed. The approach has also been applied for medical related applications as blood pressure and heart beats monitoring. In this paper we demonstrate its capability to monitor glucose concentration in blood stream. The technique is based on the tracking of temporal changes of reflected secondary speckle produced in human skin (wrist) when being illuminated by a laser beam. A temporal change in skin's vibration profile generated due to blood pulsation is analyzed for estimating the glucose concentration. Experimental tests that were carried out in order to verify the proposed approach showed good match with the change of the glucose level at the positive slope stage as it was obtained from conventional reference measurement. PMID:21483609

  18. Investigation of 18F-2-deoxyglucose for the measure of myocardial glucose metabolism

    International Nuclear Information System (INIS)

    18F labeled 2-deoxyglucose (18FDG) was studied as a glucose analog. Myocardial uptake and retention, blood clearance, species (dog, monkey, man) dependence and effect of diet on uptake were investigated. Normal myocardial uptake of 18FDG was 3 to 4% in dog and monkey and 1 to 4% of injected dose in man compared to brain uptake of 2% in dog, 5 to 6% in monkey and 4 to 8% in man. The metabolic rate (MR) for glucose in non-fasting (glycolytic state) was 2.8 times greater than in fasting (ketogenic state). Human subjects showed higher myocardial uptake after a normal meal than after meal containing mostly free fatty acids (FFA). Blood clearance was rapid with initial clearance t1/2 of 0.2 to 0.3 min followed by a t1/2 of 8.4 +- 1.2 min in dog and 11.6 +- 1.1 min in man. A small third component had a t1/2 of 59 +- 10 min and 88 +- 4 min in dog and man, respectively. High image contrast ratios between heart and blood (dog 3.5/1; man 14/1), heart and lung (dog 9/1; man 20/1), heart and liver (dog 15/1; man 10/1) were found with the ECAT positron tomograph. 18FDG was found to be rapidly taken up by the myocardium without any significant tissue clearance over a 4 hour period. 18FDG is transported, phosphorylated to 18FDG-6-PO4 and trapped in myocardial cells in the same manner as has been found for brain and exhibits excellent imaging properties. Determination of glucose and FFA MR in vivo with ECT provides a method for investigation and assessment of changing aerobic and anaerobic metabolic rates in ischemic heart disease in man

  19. Double-injection FDG method to measure cerebral glucose metabolism twice in a single procedure

    International Nuclear Information System (INIS)

    [18F]fluorodeoxyglucose (FDG) and positron emission tomography (PET) may be used to examine changes in cerebral glucose metabolism in two physiological conditions. We proposed and evaluated a double injection-single session FDG method with biological constraints for this purpose. Simulated brain time-radioactivity curves (TACs) generated by using a plasma TAC from an actual study and physiological combinations of input values in a kinetic model were analyzed to evaluate the accuracy of the proposed method. The reproducibility of the estimated values obtained by this method was tested in five normal volunteers who were studied with a dynamic PET scan and two injections of FDG in a single session while fasting. The simulation study showed that the estimated values obtained by the proposed method agreed well with the input values. In the human study, plasma glucose levels were 5.3±0.2 and 5.0±0.2 mM in the first and second measurements, respectively. The difference between the plasma glucose measurements was small but statistically significant (p*1 or rCMRglc, there were small deviations in K* (less than 10%) and LC (less than 5%) with a statistical significance (p* and LC seemed to relate to the difference in the plasma glucose level. The double-injection FDG method with biological constrains can be used to estimate rCMRglc and LC sequentially in a single PET scanning session. (author)

  20. Study on the noninvasive blood glucose measurement by diffusion reflectance NIR spectroscopy

    Science.gov (United States)

    Zhang, Hongyan; Song, Liqiang; Wang, Hongyan; Wang, Cheng; Tang, Yuguo

    2005-01-01

    The noninvasive measurement of human blood glucose has been a hotspot for a long time to all clinical workers over the world. In this paper the noninvasive measurement of human blood glucose with diffusion reflectance NIR spectrum method is presented. The thumb fingertip, the palm and the wrist with vein are chosen for the collection of diffusion reflectance NIR spectroscopy from six different age healthy volunteers using Nexus-870 and its NIR fiber port smart accessory. The calibration model is set up in 7500~8500cm-1 region that has the absorption of the glucose using Partial Least Squares (PLS) method with the first and second derivative spectral that had been smoothed and baseline corrected for single volunteer. The actual blood glucose value is determined by an ultraviolet spectrophotometer. The model with the spectrum obtained at the wrist is better than from other part for all volunteers, and it is much steadier with the second derivative pretreatment spectral than with the first derivative ones. The correlative coefficients are all over 0.93772; RMSECs are all less than 0.310 and the max differences are between -0.6mmo/L and +0.8mmo/L with the second derivative method. Some samples are kept for prediction with their own model. The differences are under 0.875529mmol/L.

  1. Design of an analog front-end for ambulatory biopotential measurement systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jiazhen; Xu Jun; Zheng Lirong; Ren Junyan, E-mail: jxu@fudan.edu.c [State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

    2010-10-15

    A continuously tunable gain and bandwidth analog front-end for ambulatory biopotential measurement systems is presented. The front-end circuit is capable of amplifying and conditioning different biosignals. To optimize the power consumption and simplify the system architecture, the front-end only adopts two-stage amplifiers. In addition, careful design eliminates the need for chopping circuits. The input-referred noise of the system is only 1.19 {mu}Vrms (0.48-2000 Hz). The chip is fabricated via a SMIC 0.18 {mu}m CMOS process. Although the power consumption is only 32.1 {mu}W under a 3 V voltage supply, test results show that the chip can successfully extract biopotential signals. (semiconductor integrated circuits)

  2. Design of an analog front-end for ambulatory biopotential measurement systems

    International Nuclear Information System (INIS)

    A continuously tunable gain and bandwidth analog front-end for ambulatory biopotential measurement systems is presented. The front-end circuit is capable of amplifying and conditioning different biosignals. To optimize the power consumption and simplify the system architecture, the front-end only adopts two-stage amplifiers. In addition, careful design eliminates the need for chopping circuits. The input-referred noise of the system is only 1.19 ?Vrms (0.48-2000 Hz). The chip is fabricated via a SMIC 0.18 ?m CMOS process. Although the power consumption is only 32.1 ?W under a 3 V voltage supply, test results show that the chip can successfully extract biopotential signals. (semiconductor integrated circuits)

  3. Measurement of glucose utilization by Pseudomonas fluorescens that are free-living and that are attached to surfaces

    International Nuclear Information System (INIS)

    The assimilation and respiration of glucose by attached and free-living Pseudomonas fluorescens were compared. The attachment surfaces were polyvinylidene fluoride, polyethylene, and glass. Specific uptake of [1C]glucose was determined after bacterial biomass was measured by (1) microscopic counts or (2) prelabelling of cells by providing [3H]leucine as substrate, followed by dual-labelling scintillation counting. The glucose concentration was 1.4, 3.5, 5.5, 7.6, or 9.7 ?M. Glucose assimilation by cells which became detached from the surfaces during incubation with glucose was also measured after the detached cells were collected by filtration. The composition of the substratum had no effect on the amount of glucose assimilated by attached cells. Glucose assimilation by attached cells exceeded that by free-living cells by a factor of between 2 and 5 or more, and respiration of glucose by surface-associated cells was greater than that by free-living bacteria. Glucose assimilation by detached cells was greater than that by attached bacteria. Measurements of biomass by microscopic counts gave more consistent results than those obtained with dual-labelling, but in general, results obtained by both methods were corroborative

  4. Angular measurements of light scattered by the glucose containing biological tissues and their phantoms

    International Nuclear Information System (INIS)

    Method of optical polarimetry is well known, but earlier it was mainly used to low scattering media. In this paper we consider the possibility of measuring the glucose concentration by detecting polarization of the backscattered laser light. Dependencies of the degree of polarization and of the optical rotation on the registration angle were received. Furthermore, the significant impact of the wavelength and the power of probing beam on the degree of polarization was shown

  5. Evaluation of the Efficacy and Correlation between Blood Glucose Measured Using Glucometers and Enzymatic Laboratory Methods

    Directory of Open Access Journals (Sweden)

    R Rasouli

    2012-05-01

    Full Text Available

    Background and Objectives: Diabetes Mellitus (DM is the most common chronic metabolic disease, with many complications including renal failure, blindness and non-traumatic amputation, so it is important to monitor and regulate blood glucose. Considering how easy home blood glucose monitoring is, we decided to evaluate the performance of two available glucometers for detection of blood glucose compared with standard laboratory methods.

     

    Methods: In this analytical study, we compared the capillary blood glucose levels of 60 volunteers with mean age of 32.8±9.6 years in Tabriz Mehr Laboratory as determined by test strips (two different Glucometers with venous blood glucose levels’ measurements by the enzymatic method (the standard laboratory kit. Data were analyzed using one way-ANOVA test, T-test, Pearson correlation and Bland and Altman plot.

     

    Results: The mean differences of No: 1 and No: 2 Glucometers with enzymatic laboratory method were 20.78±11.61 and 4.5±3.76mg/dl respectively. The one way ANOVA test indicated significant differences between three methods (p<0.05. Further Duncan's test revealed significant differences between two devices (p=0.001 and device No.1 and laboratory method (p=0.001; however, the differences between device No.2 and laboratory method were not statistically significant (p=0.83.

     

    Conclusion: According to the results, calibrating the devices with laboratory instruments in order to make major clinical decisions is recommended.

  6. The characteristic time of glucose diffusion measured for muscle tissue at optical clearing

    International Nuclear Information System (INIS)

    The study of agent diffusion in biological tissues is very important to understand and characterize the optical clearing effects and mechanisms involved: tissue dehydration and refractive index matching. From measurements made to study the optical clearing, it is obvious that light scattering is reduced and that the optical properties of the tissue are controlled in the process. On the other hand, optical measurements do not allow direct determination of the diffusion properties of the agent in the tissue and some calculations are necessary to estimate those properties. This fact is imposed by the occurrence of two fluxes at optical clearing: water typically directed out of and agent directed into the tissue. When the water content in the immersion solution is approximately the same as the free water content of the tissue, a balance is established for water and the agent flux dominates. To prove this concept experimentally, we have measured the collimated transmittance of skeletal muscle samples under treatment with aqueous solutions containing different concentrations of glucose. After estimating the mean diffusion time values for each of the treatments we have represented those values as a function of glucose concentration in solution. Such a representation presents a maximum diffusion time for a water content in solution equal to the tissue free water content. Such a maximum represents the real diffusion time of glucose in the muscle and with this value we could calculate the corresponding diffusion coefficient. (paper)

  7. Working Memory and Dynamic Measures of Analogical Reasoning as Predictors of Children's Math and Reading Achievement

    Science.gov (United States)

    Stevenson, Claire E.; Bergwerff, Catharina E.; Heiser, Willem J.; Resing, Wilma C. M.

    2014-01-01

    Working memory and inductive reasoning ability each appear related to children's achievement in math and reading. Dynamic measures of reasoning, based on an assessment procedure including feedback, may provide additional predictive value. The aim of this study was to investigate whether working memory and dynamic measures of analogical…

  8. A New System Noise Measurement Method Using a 2-bit Analog-To-Digital Converter

    CERN Document Server

    Nakatake, Aki; Takeda, Koji

    2010-01-01

    We propose a new method to measure the system noise temperature, $T_{\\rm sys}$, using a 2-bit analog-to-digital converter (ADC). The statistics of the digitized signal in a four-level quantization brings us information about the bias voltage and the variance, which reflects the power of the input signal. Comparison of the variances in {\\it hot} and {\\it sky} circumstances yields $T_{\\rm sys}$ without a power meter. We performed test experiments using the Kagoshima 6-m radio telescope and a 2-bit ADC to verify this method. Linearity in the power-variance relation was better than 99% within the dynamic range of 10 dB. Digitally measured $T_{\\rm sys}$ coincided with that of conventional measurement with a power meter in 1.8-% difference or less for elevations of $10^{\\circ} - 88^{\\circ}$. No significant impact was found by the bias voltages within the range between -3.7 and +12.8% with respect to the threshold voltage. The proposed method is available for existing interferometers that have a multi-level ADC, and...

  9. IN SITU MEASUREMENTS OF THE SIZE AND DENSITY OF TITAN AEROSOL ANALOGS

    International Nuclear Information System (INIS)

    The organic haze produced from complex CH4/N2 chemistry in the atmosphere of Titan plays an important role in processes that occur in the atmosphere and on its surface. The haze particles act as condensation nuclei and are therefore involved in Titan's methane hydrological cycle. They also may behave like sediment on Titan's surface and participate in both fluvial and aeolian processes. Models that seek to understand these processes require information about the physical properties of the particles including their size and density. Although measurements obtained by Cassini-Huygens have placed constraints on the size of the haze particles, their densities remain unknown. We have conducted a series of Titan atmosphere simulation experiments and measured the size, number density, and particle density of Titan aerosol analogs, or tholins, for CH4 concentrations from 0.01% to 10% using two different energy sources, spark discharge and UV. We find that the densities currently in use by many Titan models are higher than the measured densities of our tholins.

  10. High Precision Dielectric Permittivity Measurements of Planetary Regolith analogs Using A Split-Cylinder Resonator

    Science.gov (United States)

    Tsai, C. A.; Boivin, A.; Ghent, R. R.; Daly, M. G.; Bailey, R. C.

    2014-12-01

    Complex relative permittivity is essential for quantitative interpretation of radar data in remote sensing of planetary surfaces. The real part determines the speed of the electromagnetic waves, while the imaginary part is related to the penetration depth. This project is part of NASA's OSIRIS-REx asteroid sample return mission. Radar is an important tool for asteroid investigation, particularly for detecting and characterizing regolith; but without robust knowledge of dielectric properties, these data cannot be used to their greatest advantage. Here, we present preliminary measurements of complex relative permittivity using the split-cylinder resonator method at 10 GHz. Resonant cavity methods utilize the difference in resonant frequency between an empty cavity and a cavity containing a sample to calculate relative permittivity and loss tangent of the sample, at higher precision than is possible with other methods. We use these split-cylinder measurements of solid samples at a single frequency in conjunction with companion broadband (300 MHz to 14 GHz) measurements of powders. Our goal is to establish a "parameter space" that characterize the effects of various factors such as water content, frequency, and the relative abundances of mineralogical and elemental constituents such as iron and titanium on complex relative permittivity of geological materials that might represent good analogs for the regolith of Bennu, OSIRIS-REx's target asteroid. Our results will also provide a database for future asteroid exploration with radar.

  11. Continuous glucose monitoring in newborn infants: how do errors in calibration measurements affect detected hypoglycemia?

    Science.gov (United States)

    Thomas, Felicity; Signal, Mathew; Harris, Deborah L; Weston, Philip J; Harding, Jane E; Shaw, Geoffrey M; Chase, J Geoffrey

    2014-05-01

    Neonatal hypoglycemia is common and can cause serious brain injury. Continuous glucose monitoring (CGM) could improve hypoglycemia detection, while reducing blood glucose (BG) measurements. Calibration algorithms use BG measurements to convert sensor signals into CGM data. Thus, inaccuracies in calibration BG measurements directly affect CGM values and any metrics calculated from them. The aim was to quantify the effect of timing delays and calibration BG measurement errors on hypoglycemia metrics in newborn infants. Data from 155 babies were used. Two timing and 3 BG meter error models (Abbott Optium Xceed, Roche Accu-Chek Inform II, Nova Statstrip) were created using empirical data. Monte-Carlo methods were employed, and each simulation was run 1000 times. Each set of patient data in each simulation had randomly selected timing and/or measurement error added to BG measurements before CGM data were calibrated. The number of hypoglycemic events, duration of hypoglycemia, and hypoglycemic index were then calculated using the CGM data and compared to baseline values. Timing error alone had little effect on hypoglycemia metrics, but measurement error caused substantial variation. Abbott results underreported the number of hypoglycemic events by up to 8 and Roche overreported by up to 4 where the original number reported was 2. Nova results were closest to baseline. Similar trends were observed in the other hypoglycemia metrics. Errors in blood glucose concentration measurements used for calibration of CGM devices can have a clinically important impact on detection of hypoglycemia. If CGM devices are going to be used for assessing hypoglycemia it is important to understand of the impact of these errors on CGM data. PMID:24876618

  12. A Novel Analog Integrated Circuit Design Course Covering Design, Layout, and Resulting Chip Measurement

    Science.gov (United States)

    Lin, Wei-Liang; Cheng, Wang-Chuan; Wu, Chen-Hao; Wu, Hai-Ming; Wu, Chang-Yu; Ho, Kuan-Hsuan; Chan, Chueh-An

    2010-01-01

    This work describes a novel, first-year graduate-level analog integrated circuit (IC) design course. The course teaches students analog circuit design; an external manufacturer then produces their designs in three different silicon chips. The students, working in pairs, then test these chips to verify their success. All work is completed within…

  13. Analog earthquakes

    International Nuclear Information System (INIS)

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository

  14. Analog earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, R.B. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)

    1995-09-01

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository.

  15. Measurement of temporal asymmetries of glucose consumption using linear profiles: reproducibility and comparison with visual analysis

    International Nuclear Information System (INIS)

    The aim of our study was to test the reproducibility of this method and to compare its diagnostic performance to that of visual analysis in patients with complex partial seizures (CPS). Regional cerebral glucose consumption (rCMRGLc) was measured interictally in 25 CPS patients and 10 controls using F-18-deoxyglucose and the positron emission tomography (PET) camera ECAT EXACT 47. The PET scans were visually analyzed for the occurrence of unilateral temporal hypometabolism. Furthermore, rCMRGLc was quantified on six contiguous coronal planes by manually tracing maximal values of temporal glucose consumption, thus creating line profiles of temporal glucose consumption for each side. Indices of asymmetry (ASY) were then calculated from these line profiles in four temporal regions and compared to the corresponding 95% confidence intervals of the control data. All analyses were performed by two observers independently from each other and without knowledge of the clinical findings. The agreement between the two observers with regard to focus lateralization was 96% on visual analysis and 100% on quantitative analysis. There was an excellent agreement with regard to focus lateralization between visual and quantitative evaluation. (orig.)

  16. Fabrication and Characterization of Graphene-Based Electrochemical Sensors for Glucose Measurement.

    Science.gov (United States)

    Park, Minjeong; Choi, Hyonkwang; Park, Yunjae; Lee, Wookyoung; Lee, Jewon; Jeon, Minhyon

    2015-10-01

    Glucose in the blood is generally measured by electrochemical method using glucose oxidase (GOx) which acts as enzymes and reduced graphene oxide (rGO) composite. The rGO, which has low dispersibility, reduces the sensing capability of sensors. In order to solve this problem, the rGO electrodes with the addition of polyvinylpyrrolidone (PVP) have been reported. However, rGO with low electrical conductivity and mobility is not compatible to the electrochemical system. In this study, graphene with excellent electrical properties was added to PVP protected rGO. The rGO was synthesized using a Hummer and Offeman's method. Graphene was synthesized using chemical vapor deposition (CVD) with a Cu catalyst. Platinum (Pt) electrodes, Ag/AgCl, and PVP protected rGO were used as working electrode, reference electrode, and counter electrode, respectively. Surface morphology and structural properties of graphene were analyzed using atomic force microscopy (AFM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FT-IR). Cyclic voltametry (CV) and I-V probe station were used to analyze the performance of the electrodes. Glucose concentration was systematically varied and the reduction current was monitored using I-V probe station. PMID:26726435

  17. Simultaneous measurement of blood flow and glucose metabolism by autoradiographic techniques

    International Nuclear Information System (INIS)

    A double tracer autoradiographic technique using 131I-iodo-antipyrine and 14C-deoxyglucose is presented for the simultaneous measurement of blood flow and cerebral glucose utilization in the same animal. 131I is a gamma emitting isotope with a half life of 8.06 days and can be detected with adequate resolution on standard autoradiographic films. Autoradiograms are made before and after decay of 131I; the time interval between the 2 exposures and the concentration of the 2 tracers is adjusted to avoid significant cross-contamination. In this way, 2 film exposures are obtained which can be processed quantitatively like single tracer autoradiograms. The validity of the method for the investigation of local coupling of flow and metabolism was tested under various physiological and pathophysiological conditions. Coupling was tight in barbiturate-anesthetized healthy animals, but not under halothane anesthesia where uncoupling occurred in various subcortical structures. Focal seizures induced by topical application of penicillin on the cortical surface led to a coupled increase of metabolism and flow in thalamic relay nuclei but not at the site of penicillin administration where increased glucose utilization was not accompanied by similar increase in blood flow. Both coupled and uncoupled increases in local glucose utilization were observed in spreading depression and in circumscribed areas of experimental brain tumors. The results obtained demonstrate that double tracer autoradiography allows allows the very precise local assessment of cerebral blood flow and glucose utilization, and, therefore, is particularly suited to the study of regional coupling processes under various experimental conditions

  18. Associations of Body Composition Measurements with Serum Lipid, Glucose and Insulin Profile: A Chinese Twin Study

    Science.gov (United States)

    Liao, Chunxiao; Gao, Wenjing; Cao, Weihua; Lv, Jun; Yu, Canqing; Wang, Shengfeng; Zhou, Bin; Pang, Zengchang; Cong, Liming; Wang, Hua; Wu, Xianping; Li, Liming

    2015-01-01

    Objectives To quantitate and compare the associations of various body composition measurements with serum metabolites and to what degree genetic or environmental factors affect obesity-metabolite relation. Methods Body mass index (BMI), waist circumference (WC), lean body mass (LBM), percent body fat (PBF), fasting serum high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), total cholesterol (TC), glucose, insulin and lifestyle factors were assessed in 903 twins from Chinese National Twin Registry (CNTR). Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated from fasting serum glucose and insulin. Linear regression models and bivariate structural equation models were used to examine the relation of various body composition measurements with serum metabolite levels and genetic/environmental influences on these associations, respectively. Results At individual level, adiposity measurements (BMI, WC and PBF) showed significant associations with serum metabolite concentrations in both sexes and the associations still existed in male twins when using within-MZ twin pair comparison analyses. Associations of BMI with TG, insulin and HOMA-IR were significantly stronger in male twins compared to female twins (BMI-by-sex interaction p = 0.043, 0.020 and 0.019, respectively). Comparison of various adiposity measurements with levels of serum metabolites revealed that WC explained the largest fraction of variance in serum LDL-C, TG, TC and glucose concentrations while BMI performed best in explaining variance in serum HDL-C, insulin and HOMA-IR levels. Of these phenotypic correlations, 64–81% were attributed to genetic factors, whereas 19–36% were attributed to unique environmental factors. Conclusions We observed different associations between adiposity and serum metabolite profile and demonstrated that WC and BMI explained the largest fraction of variance in serum lipid profile and insulin resistance, respectively. To a large degree, shared genetic factors contributed to these associations with the remaining explained by twin-specific environmental factors. PMID:26556598

  19. Measuring Deuterium Enrichment of Glucose Hydrogen Atoms by Gas Chromatography/Mass Spectrometry

    OpenAIRE

    Antoniewicz, Maciek R.; Kelleher, Joanne K.; Stephanopoulos, Gregory

    2011-01-01

    We developed a simple and accurate method for determining deuterium enrichment of glucose hydrogen atoms by electron impact gas chromatography mass spectrometry (GC/MS). First, we prepared 18 derivatives of glucose and screened over 200 glucose fragments to evaluate the accuracy and precision of mass isotopomer data for each fragment. We identified three glucose derivatives that gave six analytically useful ions: (1) glucose aldonitrile pentapropionate (m/z 173 derived from C4?C5 bond cleavag...

  20. PING Gamma Ray and Neutron Measurements of a Meter-Sized Carbonaceous Asteroid Analog

    Science.gov (United States)

    Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S.; Lim, L.; McClanahan, T.; Namkung, M.; Nowicki, S.; Parsons, A.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-01-01

    Determining the elemental composition of carbonaceous (spectral type C) asteroids is still one of the basic problems when studying these objects. The only main source of elemental composition information for asteroids is from their optical, NIR and IR properties, which include their spectral reflectance characteristics, albedo, polarization, and the comparison of optical spectroscopy with meteorite groups corresponding to asteroids of every spectral type. Unfortunately, these sources reflect observations from widely contrasting spatial scales that presently yield a void in the continuum of microscopic and macroscopic evidence, a lack of in situ measurement confirmation, and require deeper sensing techniques to discern the nature of these asteroids. The Probing In situ with Neutrons and Gamma rays (PING) instrument is ideally suited to address this problem because it can be used to determine the bulk elemental composition, H and C content, the average atomic weight and density of the surface and subsurface layers of C-type asteroids, and can provide measurements used to determine the difference between and distinguish between different types of asteroids. We are currently developing the PING instrument that combines gamma ray and neutron detectors with a 14 Me V pulsed neutron generator to determine the in-situ bulk elemental abundances and geochemistry of C-type asteroids with a spatial resolution of 1 m down to depths of tens of cm to 1 m. One aspect of the current work includes experimentally testing and optimizing PING on a known meter-sized Columbia River basalt C-type asteroid analog sample that has a similar composition and the same neutron response as that of a C-type asteroid. An important part of this effort focuses on utilizing timing measurements to isolate gamma rays produced by neutron inelastic scattering, neutron capture and delayed activation processes. Separating the gamma ray spectra by nuclear processes results in higher precision and sensitivity elemental composition measurements. Using gated data acquisition techniques allows for the unambiguous identification of gamma ray lines from different isotopes and nuclear processes, especially in situations when limited detector resolution results in overlapping gamma ray lines that cannot be individually resolved. In this paper, we will present the PING basalt layering experimental data, taken at the test facility at NASA Goddard Space Flight Center using the time tagged event-by-event data analysis technique, compared to our MCNPX computer simulation results for the C-type asteroid and basalt layering simulant models. Comparison of these data will show the advantages, validity, and measurement sensitivity of PING's nuclear interrogation methods to obtain more precise and sensitive in situ bulk elemental composition and density measurements of the subsurface of asteroids.

  1. Clinical review: Consensus recommendations on measurement of blood glucose and reporting glycemic control in critically ill adults

    OpenAIRE

    Finfer, Simon; Wernerman, Jan; Preiser, Jean-Charles; Cass, Tony; Desaive, Thomas; Hovorka, Roman; Joseph, Jeffrey I.; Kosiborod, Mikhail; Krinsley, James; Mackenzie, Iain; Mesotten, Dieter; Schultz, Marcus J.; Scott, Mitchell G; Slingerland, Robbert; den Berghe, Greet Van

    2013-01-01

    The management reporting and assessment of glycemic control lacks standardization. The use of different methods to measure the blood glucose concentration and to report the performance of insulin treatment yields major disparities and complicates the interpretation and comparison of clinical trials. We convened a meeting of 16 experts plus invited observers from industry to discuss and where possible reach consensus on the most appropriate methods to measure and monitor blood glucose in criti...

  2. Measurement of glucose metabolism in rat spinal cord slices with dynamic positron autoradiography

    International Nuclear Information System (INIS)

    We attempted to measure the regional metabolic rate of glucose (MRglc) in sliced spinal cords in vitro. The thoracic spinal cord of a mature Wister rat was cut into 400-?m slices in oxygenated and cooled (1-4 deg. C) Krebs-Ringer solution. After at least 60 min of preincubation, the spinal cord slices were transferred into double polystyrene chambers and incubated in Krebs-Ringer solution at 36 deg. C, bubbled with 5% O2/5% CO2 gas. To measure MRglc, we used the dynamic positron autoradiography technique (dPAT) with F-18-2-fluoro-2-deoxy-D-glucose ([18F]FDG) and the net influx constant of [18F]FDG as an index. Uptake curves of [18F]FDG were well fitted by straight lines for more than 7 h after the slicing of the spinal cord (linear regression coefficient, r=0.99), indicating a constant uptake of glucose by the spinal cord tissue. The slope (K), which denotes MRglc, is affected by tetrodotoxin, and high K+ (50 mM) or Ca2+-free, high Mg2+ solution. After 10 min of hypoxia, the K value following reoxygenation was similar to the unloaded control value, but after 45 min of hypoxia, the K value was markedly lower than the unloaded control value, and after >90 min of reoxygenation it was nearly 0. Our results indicate that the living spinal cord slices used retained an activity-dependent metabolism to some extent. This technique may provide a new approach for measuring MRglc in sliced living spinal cord tissue in vitro and for quantifying the dynamic changes in MRglc in response to various interventions such as hypoxia

  3. Measurement of glucose metabolism in rat spinal cord slices with dynamic positron autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Fan Xiaoping [Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People' s Hospital, Guangzhou 510100 (China); Asai, Tatsuya [Biomedical Imaging Research Center, University of Fukui, Eiheiji-cho, Fukui 910-1193 (Japan); Morioka, Koichi [Department of Cardiovascular Surgery II, University of Fukui, Eiheiji-cho, Fukui 910-1193 (Japan); Uchida, Kenzo; Baba, Hisatoshi [Department of Orthopaedics and Rehabilitation Medicine, University of Fukui, Eiheiji-cho, Fukui 910-1193 (Japan); Tanaka, Kuniyoshi [Department of Cardiovascular Surgery II, University of Fukui, Eiheiji-cho, Fukui 910-1193 (Japan); Zhuang Jian [Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People' s Hospital, Guangzhou 510100 (China); Okazawa, Hidehiko [Biomedical Imaging Research Center, University of Fukui, Eiheiji-cho, Fukui 910-1193 (Japan); Fujibayashi, Yasuhisa [Biomedical Imaging Research Center, University of Fukui, Eiheiji-cho, Fukui 910-1193 (Japan)], E-mail: yfuji@u-fukui.ac.jp

    2009-02-15

    We attempted to measure the regional metabolic rate of glucose (MRglc) in sliced spinal cords in vitro. The thoracic spinal cord of a mature Wister rat was cut into 400-{mu}m slices in oxygenated and cooled (1-4 deg. C) Krebs-Ringer solution. After at least 60 min of preincubation, the spinal cord slices were transferred into double polystyrene chambers and incubated in Krebs-Ringer solution at 36 deg. C, bubbled with 5% O{sub 2}/5% CO{sub 2} gas. To measure MRglc, we used the dynamic positron autoradiography technique (dPAT) with F-18-2-fluoro-2-deoxy-D-glucose ([{sup 18}F]FDG) and the net influx constant of [{sup 18}F]FDG as an index. Uptake curves of [{sup 18}F]FDG were well fitted by straight lines for more than 7 h after the slicing of the spinal cord (linear regression coefficient, r=0.99), indicating a constant uptake of glucose by the spinal cord tissue. The slope (K), which denotes MRglc, is affected by tetrodotoxin, and high K{sup +} (50 mM) or Ca{sup 2+}-free, high Mg{sup 2+} solution. After 10 min of hypoxia, the K value following reoxygenation was similar to the unloaded control value, but after 45 min of hypoxia, the K value was markedly lower than the unloaded control value, and after >90 min of reoxygenation it was nearly 0. Our results indicate that the living spinal cord slices used retained an activity-dependent metabolism to some extent. This technique may provide a new approach for measuring MRglc in sliced living spinal cord tissue in vitro and for quantifying the dynamic changes in MRglc in response to various interventions such as hypoxia.

  4. Myocardial glucose uptake and metabolic rate measurements in mice with microPET imaging

    International Nuclear Information System (INIS)

    Objective: To establish a practical microPET imaging procedure for the measurement of myocardial metabolic rate of glucose (MRGlu) in mice. Methods: Twenty wild-type BKS mice were divided into 4 groups by random number table method.The mice were anesthetized with different concentrations of isoflurane (1.3%, 1.5%, 1.8%, 2.0%) at the temperature between 30 ? to 34 ?. The respiratory rate and the physiologic condition were monitored for adjusting the most appropriate isoflurane concentration. Then, different volumes of saline were injected to the anesthetized mice and blood glucose concentrations were measured to test the optimal injection volume. Under the optimal operating condition, 18F-FDG were injected in a group of six mice and followed by microPET imaging.Left ventricular TAC was obtained by drawing ROI and myocardial glucose SUV was also calculated. Meanwhile, the TAC from venous sampling at different time points after 18F-FDG injection was generated. 'Kinetic Imaging System' was used to estimate the coefficients and calculate the MRGlu (Ki ×Glu/LC; Ki =k1 ×k3/(k2 + k3). One-way analysis of variance and q test were used to analyze the data. Results: No movement was observed in non-fasted mice anesthetized with (1.5-1.8)% isoflurane, and their respiratory rates were all over 80 per minute. The plasma glucose concentration showed no difference at each time point between the experimental group injected with 75 ?l saline and the control group (F=1.215, P>0.05). The plasma glucose concentration of mice injected with 150 ?l saline exhibited statistically significant difference at 30 min (q=2.485, P=0.024), 45 min (q=2.287, P=0.036) and 60 min (q=2.709, P=0.015). When the injection volume reached 300 ?l, the blood glucose concentration increased remarkably at 45 min (q=2.435, P=0.027). Mice were maintained in good condition after injected with 18F-FDG ranging from 7.4 to 11.1 MBq within 75 ?l volume, meanwhile clear and stable myocardial microPET images could also be obtained. The median myocardial SUV value was 11.88 (9.71-14.93), Ki value was 0.19 (0.10-0.54) ml · min-1 · g-1 and MRGlu value was 19.64 (5.55-23.28) mg · kg-1 · min-1 at 45-55 min after 18F-FDG injection. Conclusion: The microPET imaging may be a reliable,practical method to evaluate myocardial glucose uptake rate and metabolic rate in mice under the precondition of optimal isoflurane anesthetization (1.5%-1.8%) and small volume of 18F-FDG injection (?<75 ?l). (authors)

  5. Simplified brain slice glucose utilization.

    Science.gov (United States)

    Newman, G C; Hospod, F E; Maghsoudlou, B; Patlak, C S

    1996-09-01

    Brain slice glucose utilization (SGU) can be measured by methods analogous to those used for in vivo cerebral glucose utilization. In order to make this technique more accessible and applicable to a broad range of experimental conditions, we have derived a simplified operational rate equation and generated the table of apparent rate coefficients necessary to apply the equation under different experimental situations. Calculations of the apparent rate coefficients were based upon an eight-parameter kinetic model combined with Michaelis-Menten theory to account for changes in the rate constants as a function of buffer glucose concentration. The theory was tested with a series of experiments using rat brain slices. [14C]-2-deoxyglucose (2DG) and [14C]-3-O-methylglucose (3OMG). The errors involved in the simplified technique were estimated by a variety of techniques and found to be acceptable over a broad range of conditions. A detailed, practical protocol for the simplified method is presented. PMID:8784231

  6. Associations between insulin and glucose concentrations and anthropometric measures of fat mass in Australian adolescents

    Directory of Open Access Journals (Sweden)

    Denney-Wilson Elizabeth

    2010-08-01

    Full Text Available Abstract Background One of the most serious, yet common co-morbidities of obesity is insulin resistance, which if untreated may progress to type 2 diabetes. This paper describes the insulin and glucose concentration distributions, the prevalence of elevated insulin, the associations between insulin and body mass index (BMI, waist circumference, waist-to-height ratio (WHtR and fat mass index in a representative sample of Australian adolescents. Methods Cross-sectional population-based study of adolescent boys and girls (N = 496, mean age 15.3 years attending schools in metropolitan Sydney, Australia. Fasting venous blood collected and analysed for insulin and glucose concentrations. Height, weight, waist circumference measured, BMI and waist-to-height ratio calculated. Pubertal status self-reported. Results Glucose concentrations were normally distributed and were not associated with adiposity. Insulin concentrations were distributed logarithmically, were higher among girls than boys overall and within the same ranges of BMI and waist circumference, but were lower among girls than boys within the same ranges of fat mass adjusted for height. The prevalence of elevated insulin concentration (defined as > 100 pmol/L was 15.9% and 17.1% among boys and girls, respectively. Correlations between insulin concentration and BMI, waist circumference, WHtR and fat mass adjusted for height were 0.53, 0.49, 0.51 and 0.55, among boys, respectively, and 0.35, 0.40, 0.42 and 0.34, among girls, respectively. Conclusions Elevated insulin is highly correlated with adiposity in adolescents. BMI and WHtR are simple measures that can be used to identify young people who should be screened for insulin resistance and other co-morbidities.

  7. Real-time quantitative fluorescence measurement of microscale cell culture analog systems

    Science.gov (United States)

    Oh, Taek-il; Kim, Donghyun; Tatosian, Daniel; Sung, Jong Hwan; Shuler, Michael

    2007-02-01

    A microscale cell culture analog (?CCA) is a cell-based lab-on-a-chip assay that, as an animal surrogate, is applied to pharmacological studies for toxicology tests. A ?CCA typically comprises multiple chambers and microfluidics that connect the chambers, which represent animal organs and blood flow to mimic animal metabolism more realistically. A ?CCA is expected to provide a tool for high-throughput drug discovery. Previously, a portable fluorescence detection system was investigated for a single ?CCA device in real-time. In this study, we present a fluorescence-based imaging system that provides quantitative real-time data of the metabolic interactions in ?CCAs with an emphasis on measuring multiple ?CCA samples simultaneously for high-throughput screening. The detection system is based on discrete optics components, with a high-power LED and a charge-coupled device (CCD) camera as a light source and a detector, for monitoring cellular status on the chambers of each ?CCA sample. Multiple samples are characterized mechanically on a motorized linear stage, which is fully-automated. Each ?CCA sample has four chambers, where cell lines MES-SA/DX- 5, and MES-SA (tumor cells of human uterus) have been cultured. All cell-lines have been transfected to express the fusion protein H2B-GFP, which is a human histone protein fused at the amino terminus to EGFP. As a model cytotoxic drug, 10 ?M doxorubicin (DOX) was used. Real-time quantitative data of the intensity loss of enhanced green fluorescent protein (EGFP) during cell death of target cells have been collected over several minutes to 40 hours. Design issues and improvements are also discussed.

  8. Detection of glucose variability in saline solutions from transmission and reflection measurements using V-band waveguides

    Science.gov (United States)

    Cano-Garcia, Helena; Kosmas, Panagiotis; Sotiriou, Ioannis; Papadopoulos-Kelidis, Ioannis; Parini, Clive; Gouzouasis, Ioannis; Palikaras, George; Kallos, Efthymios

    2015-12-01

    This paper presents experimental results that demonstrate the correlation of glucose concentration in water and saline solutions with transmitted electromagnetic (EM) energy in the frequency range of 50–75 GHz. The system is based on placing the aqueous solutions in acrylic holding tanks sandwiched between two open V-band waveguides. The measured samples have clinically relevant range of glucose concentrations, as low as 0.025 wt%. Our measurements show for the first time that it is possible to establish an approximately linear relationship between the signals transmitted through this simple waveguide-based system and the glucose content in the samples. Accurate full-wave EM simulations confirm this linear correlation. The results suggest the possibility of developing a miniaturized non-invasive glucose sensing device based on the transmission of radio waves in this frequency range.

  9. Nucleic Acid Base Analog FRET-Pair Facilitating Detailed Structural Measurements in Nucleic Acid Containing Systems

    DEFF Research Database (Denmark)

    Börjesson, Karl; Preus, Søren; El-Sagheer, Afaf; Brown, Tom; Albinsson, Bo; Wilhelmsson, Marcus

    2009-01-01

    We present the first nucleobase analog fluorescence resonance energy transfer (FRET)-pair. The pair consists of tCO, 1,3-diaza-2-oxophenoxazine, as an energy donor and the newly developed tC(nitro), 7-nitro-1,3-diaza-2-oxophenothiazine, as an energy acceptor. The FRET-pair successfully monitors distances covering up to more than one turn of the DNA duplex. Importantly, we show that the rigid stacking of the two base analogs, and consequently excellent control of their exact positions and orienta...

  10. The relationship between HbA(1c) and fasting plasma glucose in patients with increased plasma liver enzyme measurements

    DEFF Research Database (Denmark)

    Christiansen, R; Rasmussen, L Melholt; Nybo, H; Steenstrup, T; Nybo, M

    2012-01-01

    Background:? HbA(1c) is currently being introduced for diagnostic purpose in diabetes. Previous studies have, however, indicated that patients with liver disease have false low HbA(1c) levels. We therefore investigated the correlation between HbA(1c) and plasma glucose in patients with different levels of increased liver enzyme concentrations. Methods:? Data from 10?065 patients with simultaneous measurement of HbA(1c) , venous fasting plasma glucose, alanine aminotransferase and ?-glutamyl tran...

  11. Measurements of glucose phosphorylation with FDG and PET are not reduced by dephosphorylation of FDG-6-phosphate

    DEFF Research Database (Denmark)

    Kuwabara, H; Gjedde, A

    1991-01-01

    To improve the measurements of glucose metabolism in the human brain, we imposed biologic constraints on the deoxyglucose model with and without dephosphorylation of FDG-6-phosphate (the k4*- and k3*-models). The constraints included constant transport and phosphorylation ratios (tau and phi) and a common partition volume (K1/k2) for tracer [18F]FDG and glucose. In the presence of significant dephosphorylation, the k3*-model yielded time-dependent estimates of the phosphorylation coefficient (k3...

  12. A self referencing platinum nanoparticle decorated enzyme-based microbiosensor for real time measurement of physiological glucose transport

    OpenAIRE

    McLamore, E. S.; Shi, J.; Jaroch, David; Claussen, Jonathan; Uchida, A.; Jiang, Y.; Zhang, W.; Donkin, Shawn S; Banks, M K; Buhman, K. K.; Teegarden, D.; Rickus, Jenna; Porterfield, D. Marshall

    2010-01-01

    Glucose is the central molecule in many biochemical pathways, and numerous approaches have been developed for fabricating micro biosensors designed to measure glucose concentration in/near cells and/or tissues. An inherent problem for microsensors used in physiological studies is a low signal-to-noise ratio, which is further complicated by concentration drift due to the metabolic activity of cells. A microsensor technique designed to filter extraneous electrical noise and provide direct quant...

  13. Preliminary Broadband Measurements of Dielectric Permittivity of Planetary Regolith Analog Materials Using a Coaxial Airline

    Science.gov (United States)

    Boivin, A.; Tsai, C. A.; Ghent, R. R.; Daly, M. G.

    2014-12-01

    When considering radar observations of airless bodies containing regolith, the radar backscatter coefficient is dependent upon the complex dielectric permittivity of the regolith materials. In many current applications of imaging radar data, uncertainty in the dielectric permittivity precludes quantitative estimates of such important parameters as regolith thickness and depth to buried features (e.g., lava flows on the Aristarchus Plateau on the Moon and the flows that surround the Quetzalpetlatl Corona on Venus). For asteroids, radar is an important tool for detecting and characterizing regoliths. Many previous measurements of the real and/or complex parts of the dielectric permittivity have been made, particularly for the Moon (on both Apollo samples and regolith analogues). However, no studies to date have systematically explored the relationship between permittivity and the various mineralogical components such as presence of FeO and TiO2. For lunar materials, the presence of the mineral ilmenite (FeTiO3), which contains equal portions FeO and TiO2, is thought to be the dominant factor controlling the loss tangent (tanδ, the ratio of the imaginary and real components of the dielectric permittivity). Ilmenite, however, is not the only mineral to contain iron in the lunar soil and our understanding of the effect of iron on the loss tangent is insufficient. Beyond the Moon, little is known about the effects on permittivity of carbonaceous materials. This is particularly relevant for missions to asteroids, such as the OSIRIS-REx mission to (101955) Bennu, a carbonaceous asteroid whose regolith composition is largely unknown. Here we present preliminary broadband (300 Mhz to 14 GHz) measurements on materials intended as planetary regolith analogs. Our ultimate goal is to establish a database of the effects of a wide range mineralogical components on dielectric permittivity, in support of the OSIRIS REx mission and ongoing Earth-based radar investigation of the Moon. In addition to facilitating quantitative interpretation of lunar radar data, our results will provide context into which samples returned by OSIRIS REx will fit, and will therefore inform future remote exploration of asteroids.

  14. Development of a passive air sampler to measure airborne organophosphorus pesticides and oxygen analogs in an agricultural community.

    Science.gov (United States)

    Armstrong, Jenna L; Yost, Michael G; Fenske, Richard A

    2014-09-01

    Organophosphorus pesticides are some of the most widely used insecticides in the US, and spray drift may result in human exposures. We investigate sampling methodologies using the polyurethane foam passive air sampling device to measure cumulative monthly airborne concentrations of OP pesticides chlorpyrifos, azinphos-methyl, and oxygen analogs. Passive sampling rates (m(3)d(-1)) were determined using calculations using chemical properties, loss of depuration compounds, and calibration with side-by-side active air sampling in a dynamic laboratory exposure chamber and in the field. The effects of temperature, relative humidity, and wind velocity on outdoor sampling rates were examined at 23 sites in Yakima Valley, Washington. Indoor sampling rates were significantly lower than outdoors. Outdoor rates significantly increased with average wind velocity, with high rates (>4m(3)d(-1)) observed above 8ms(-1). In exposure chamber studies, very little oxygen analog was observed on the PUF-PAS, yet substantial amounts chlorpyrifos-oxon and azinphos methyl oxon were measured in outdoor samples. PUF-PAS is a practical and useful alternative to AAS because it results in little artificial transformation to the oxygen analog during sampling, it provides cumulative exposure estimates, and the measured sampling rates were comparable to rates for other SVOCs. It is ideal for community based participatory research due to low subject burden and simple deployment in remote areas. PMID:24997910

  15. Uncertainty estimation of non-ideal analog switches using programmable Josephson voltage standards for mutual inductance measurement in the joule balance

    Science.gov (United States)

    Wang, Gang; Zhang, Zhonghua; Li, Zhengkun; Xu, Jinxin; You, Qiang

    2016-02-01

    Measurement of the mutual inductance is one of the key techniques in the joule balance to determine the Planck constant h, where a standard-square-wave compensation method was proposed to accurately measure the dc value of the mutual inductance. With this method, analog switches are used to compose an analog-switch signal generator to synthesize the excitation and compensation voltages. However, the accuracy of the compensation voltage is influenced by the non-ideal behaviors of analog-switches. In this paper, the effect from these non-ideal switches is analyzed in detail and evaluated with the equivalent circuits. A programmable Josephson voltage standard (PJVS) is used to generate a reference compensation voltage to measure the time integration of the voltage waveform generated by the analog-switch signal generator. Moreover, the effect is also evaluated experimentally by comparing the difference between the mutual inductance measured with the analog-switch signal generator and the value determined by the PJVS-analog-switch generator alternately in the same mutual inductance measurement system. The result shows that the impact of analog switches is 1.97??×??10?7 with an uncertainty of 1.83??×??10?7 (k??=??1) and confirms that the analog switch method can be used regularly instead of the PJVS in the mutual inductance measurement for the joule balance experiment.

  16. Automatic Reading Recognition System for Analog Measuring Instruments Base on Digital Image Processing

    OpenAIRE

    Junguo Zhang; Yi Wang; Fantao Lin

    2013-01-01

    Pointer instrument has been widely used in the electric power, chemical industry and other industrial fields, because of the advantages such as low price, high reliability, easy installation, replacement and so forth. The traditional manual reading method has its drawbacks for example process trival, big workload, lack of accuracy. This article, based on digital image processing techniques, studies the automatic reading recognition method for analog measuri...

  17. [{sup 18}F]-2-fluoro-2-deoxyglucose transport kinetics as a function of extracellular glucose concentration in malignant glioma, fibroblast and macrophage cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, Robert C.; Freeman, Scott D.; Charlop, Aaron W.; Wiseman, Robert W.; Adamsen, Tom C.H.; Krohn, Kenneth A.; Spence, Alexander M. E-mail: aspence@u.washington.edu

    2004-01-01

    FDG-PET is used to measure the metabolic rate of glucose. Transport and phosphorylation determine the amount of hexose analog that is phosphorylated and trapped. Competition occurs for both events, such that extracellular glucose concentration affects the FDG image. This study investigated the effect of glucose concentration on the rate of FDG accumulation in three cell lines. The results show that extracellular glucose concentration has a greater impact on the rate of FDG accumulation than the relative abundance of GLUT transporter subtypes.

  18. [18F]-2-fluoro-2-deoxyglucose transport kinetics as a function of extracellular glucose concentration in malignant glioma, fibroblast and macrophage cells in vitro

    International Nuclear Information System (INIS)

    FDG-PET is used to measure the metabolic rate of glucose. Transport and phosphorylation determine the amount of hexose analog that is phosphorylated and trapped. Competition occurs for both events, such that extracellular glucose concentration affects the FDG image. This study investigated the effect of glucose concentration on the rate of FDG accumulation in three cell lines. The results show that extracellular glucose concentration has a greater impact on the rate of FDG accumulation than the relative abundance of GLUT transporter subtypes

  19. Fructosamine: An Alternative to Serum Glucose Measurement in White-tailed Deer (Odocoileus virginianus).

    Science.gov (United States)

    DePerno, Christopher S; Chitwood, M Colter; Kennedy-Stoskopf, Suzanne; Jenks, Jonathan A

    2015-10-01

    We determined the relationship between fructosamine and serum glucose in free-ranging white-tailed deer (Odocoileus virginianus) harvested during two seasonally stressful periods for deer in coastal North Carolina, US: July 2008 represented the postparturition and lactation period, and March 2009 represented the late winter and pre-green-up period. Serum glucose and fructosamine concentrations were similar between time periods but were uncorrelated within each season. However, when serum glucose was separated into high and low categories based on the median blood glucose score within each time period, we detected statistically significant differences between July and March for serum glucose. Fructosamine was more stable than serum glucose for evaluating the white-tailed deer physiologic condition. PMID:26251990

  20. An analog computer model for calculation of exposures measured by photodosimeters

    International Nuclear Information System (INIS)

    On the basis of known methods for calculation of X-ray, gamma and beta radiation doses, and data from experiments carried out by the author, a mathematical model has been developed and programmed in several versions on an analog computer. The model is able to calculate mixed radiation exposures detected by photodosimeters. An estimate is given of the error due to the broken line approximation of the calibration curves. The possibility for an automated selection of the appropriate program according to the input information is discussed. The model can be used without substantial modifications for computation of exposures registered by photodosimeters of other types. (N.K)

  1. Synthesis and anticancer activity of new flavonoid analogs and inconsistencies in assays related to proliferation and viability measurements.

    Science.gov (United States)

    Forbes, Alaina M; Lin, Huimin; Meadows, Gary G; Meier, G Patrick

    2014-08-01

    Flavonoids have been studied intensely for their ability to act as anti-carcinogenic, anti-inflammatory, anti-viral and anti-aging agents and are often marketed as supplements related to their anti-inflammatory activity. Previous studies have primarily focused on the effects of polar natural flavonoids. We examined the activity of novel hydrophobic and lipophilic flavonols against human DU-145 and PC-3 prostate cancer cell lines. All flavonol analogs were more active than the naturally occurring flavonols quercetin, kaempferol, kaempferide and galangin. The most potent analogs were 6.5-fold more active against DU-145 and PC-3 cells than quercetin and fell within the biologically relevant concentration range (low micromolar). We also evaluated the potential toxic effects of flavonol analogs on normal cells, an assessment that has frequently been ignored when studying the anticancer effects of flavonoids. During these analyses, we discovered that various metabolic and DNA staining assays were unreliable methods for assessing cell viability of flavonoids. Flavonoids reduce colorimetric dyes such as MTT and Alamar Blue in the absence of cells. We showed that flavonol-treated prostate cancer cells were stained less intensely with crystal violet than untreated cells at non-toxic concentrations. The trypan blue exclusion assay was selected as a reliable alternative for measuring cell viability. PMID:24859601

  2. Inhibition of JNK phosphorylation by a novel curcumin analog prevents high glucose-induced inflammation and apoptosis in cardiomyocytes and the development of diabetic cardiomyopathy.

    Science.gov (United States)

    Pan, Yong; Wang, Yi; Zhao, Yunjie; Peng, Kesong; Li, Weixin; Wang, Yonggang; Zhang, Jingjing; Zhou, Shanshan; Liu, Quan; Li, Xiaokun; Cai, Lu; Liang, Guang

    2014-10-01

    Hyperglycemia-induced inflammation and apoptosis have important roles in the pathogenesis of diabetic cardiomyopathy. We recently found that a novel curcumin derivative, C66, is able to reduce the high glucose (HG)-induced inflammatory response. This study was designed to investigate the protective effects on diabetic cardiomyopathy and its underlying mechanisms. Pretreatment with C66 significantly reduced HG-induced overexpression of inflammatory cytokines via inactivation of nuclear factor-?B in both H9c2 cells and neonatal cardiomyocytes. Furthermore, we showed that the inhibition of Jun NH2-terminal kinase (JNK) phosphorylation contributed to the protection of C66 from inflammation and cell apoptosis, which was validated by the use of SP600125 and dominant-negative JNK. The molecular docking and kinase activity assay confirmed direct binding of C66 to and inhibition of JNK. In mice with type 1 diabetes, the administration of C66 or SP600125 at 5 mg/kg significantly decreased the levels of plasma and cardiac tumor necrosis factor-?, accompanied by decreasing cardiac apoptosis, and, finally, improved histological abnormalities, fibrosis, and cardiac dysfunction without affecting hyperglycemia. Thus, this work demonstrated the therapeutic potential of the JNK-targeting compound C66 for the treatment of diabetic cardiomyopathy. Importantly, we indicated a critical role of JNK in diabetic heart injury, and suggested that JNK inhibition may be a feasible strategy for treating diabetic cardiomyopathy. PMID:24848068

  3. Experimental study for cancer diagnosis with positron-labeled fluorinated glucose analogs: [18F]-2-fluoro-2-deoxy-D-mannose

    International Nuclear Information System (INIS)

    18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) and 18F-2-fluoro-2-deoxy-D-mannose (18F-FDM) were tested as tumor diagnostic agents in a transplantable rat tumor and rabbit tumors. Tissue distribution studies in rats showed high tumor uptakes of both radiopharmaceuticals. The tumor uptake reached 2.65+-0.61% dose 18F-FDG/g and 2.65+-0.81% dose 18F-FDM/g at 60 min and remained relatively constant until 120 min. Blood clearance of both 18F-FDG and 18F-FDM was very rapid and tumor-to-blood ratios reached 22.1 and 29.4 at 60 min, respectively. Tumor-to-tissue ratios of both radiopharmaceuticals were very high in most organs, especially in the liver, kidney, and pancreas. Positron emission tomography (PET) of rabbit tumor with 18F-FDM clearly delineated the main tumor, central necrosis, and lymph node metastases. These data suggested that 18F-FDM, which is a by-product of 18F-FDG synthesis, was also an excellent cancer diagnostic agent as well as 18-F-FDG. This is not only a new feature of 18F-FDM, but also an economical improvement on cancer diagnosis by PET. (orig.)

  4. Photoacoustic blood glucose and skin measurement based on optical scattering effect

    Science.gov (United States)

    Zhao, Zuomin; Myllyla, Risto A.

    2002-07-01

    Non-invasive blood glucose determination has been investigated by more than 100 research groups in the world during the past fifteen years. The commonly optical methods are based on the capacity of near-IR light to penetrate a few hundreds micrometers or a few millimeters into human tissue where it interacts with glucose. A change of glucose concentration may modify the optical parameters in tissue, with the result that its glucose concentration can be extracted by analyzing the received optical signals. This paper demonstrates that glucose affects on the scattering coefficient of human blood, by applying the streak camera and pulsed photoacoustic techniques; and drinking water seems also affecting on PA signal from skin surface.

  5. Preferred Presentation of the Visual Analog Scale for Measurement of Postoperative Pain

    DEFF Research Database (Denmark)

    Kjeldsen, Helle Birgitte; Klausen, Tobias Wirenfeldt; Rosenberg, Jacob

    2015-01-01

    performed power calculations to estimate a preferred sample size, and 62 postoperative patients supplied a complete set of data to the study. Inclusion criteria were newly operated patients within the first 5 days after surgery. Every patient included was with 1-minute intervals and presented with one of......BACKGROUND: The aim of this study was to evaluate differences in pain scores with different visual analog scale (VAS) presentations and to compare those differences with a numeric rating scale. We also asked the patients for preference of the different methods. METHODS: Prior to the trial, we...... scores than VAS, especially at low levels of pain. Patients preferred the NRS as compared to the VAS, and when choosing between the four different VAS presentations, they preferred the horizontal VAS with stop lines at the ends. CONCLUSION: For daily clinical practice for guiding postoperative analgesic...

  6. Experiments of glucose solution measurement based on the tunable pulsed laser induced photoacoustic spectroscopy method

    Science.gov (United States)

    Ren, Zhong; Liu, Guodong; Xiong, Zhihua; Huang, Zhen

    2015-07-01

    Photoacoustic spectroscopy (PAS) is a hybrid, well-established and promising detection technique that has widely applied into a lot of fields such as bio-medical, material and environment monitoring etc. PAS has high contrast and resolution because of combining the advantages of the pure-optical and the pure-acoustic. In this paper, a photoacoustic experiment of glucose solution induced by 532nm pumped Nd:YAG tunable pulsed laser with repetition rate of 20Hz and pulse width of 10ns is performed. The time-resolved photoacoustic signals of glucose solution induced by pulsed laser in the average time of 512 are obtained. And the photoacoustic experiments of different concentrations of glucose solutions and different wavelengths of pulsed laser are carried out in this paper. Experimental results demonstrate that the bipolar sine-wave profiles for the time-resolved photoacoustic signal of glucose solution are in good agreement with the past reported literatures. And the different absorbing coefficients of glucose solution can be gotten according to the slope of the first part of the time-resolved photoacoustic signals. In addition, the different acoustic velocities of glucose solution can also be gotten according to the shift change of the time-resolved photoacoustic peak values. Research results illustrate that the characteristic wavelengths, different optical and acoustic properties of glucose solution can be interpreted by the time-resolved and peak-to-peak photoacoustic signals induced by the pulsed laser.

  7. 31P-NMR-spectroscopy measurements of energy metabolism of in vivo growing ascites tumours following addition of glucose

    International Nuclear Information System (INIS)

    The cellular ATP content and the phosphorylation potential, defined as the ATP, ADP and inorganic phosphate (Pi) ratios, of exponentially growing Ehrlich ascites tumour cells were compared with cells at the plateau phase of growth. These phosphorus compounds were measured using 31P-NMR-spectroscopy immediately after removal of the cell material from the host and in their ascites fluid reflecting in vivo growth conditions. Reaching the plateau phase of growth, the ATP content and the phosphorylation potential decreased. Upon addition of glucose, the phosphorylation potential immediately increased. We concluded that the reduced phosphorylation potential was due to a limited availability of glucose in spite of the nearly normal blood glucose concentration found. An increasing diffusion distance from the host to all parts of the tumour is a possible reason for that. (orig.)

  8. Age and sex differences in cerebral glucose consumption measured by pet using [18-F] fluorodeoxyglucose (FDG)

    International Nuclear Information System (INIS)

    Resting cerebral glucose metabolic rates (CMRglc) were measured in 23 subjects by PET using FDG. Subjects were divided into several groups (mean age +- S.D.) 5 young males (YM) (27 +- 6); 6 young females (YF)(33 +9); 5 elderly males (EM)(73 +- 5); 7 elderly females (EF)(69 +- 7). Additionally, from these groups 4 YM, 3YF, 5EM and 4EF were studied again within 6 weeks under identical conditions. CMRglc in the YF group again was significantly hider than YM (p 0.05). No obvious relationships of CMRglc to the phase of the menstrual cycle was found in this small group. There was a trend (p=0.06) toward a higher CMRglc in YF than EF. These results support the findings of higher CBF in YF versus YM. The differences between the results of Kuhl et al (J. Cereb. and a reduction of CMRglc with age was found in a mixed group of males and females (58and female), and where no age effect was found the males, are also resolved by these findings. The authors suggest that the apparent age effect, in females in this study, is principally a hormonal one

  9. Measurement of regional cerebral glucose utilization in man by positron emission tomography

    International Nuclear Information System (INIS)

    The various methods available for the study of regional cerebral glucose consumption in man by positron emission tomography are described and their applications, limitations and principal physiopathological results are presented

  10. Glucose control.

    Science.gov (United States)

    Preiser, Jean-Charles

    2013-01-01

    Stress-related hyperglycemia is a common finding in acutely ill patients, and is related to the severity and outcome of the critical illness. The pathophysiology of stress hyperglycemia includes hormonal and neural signals, leading to increased production of glucose by the liver and peripheral insulin resistance mediated by the translocation of transmembrane glucose transporters. In one pioneering study, tight glycemic control by intensive insulin therapy in critically ill patients was associated with improved survival. However, this major finding was not confirmed in several other prospective randomized controlled trials. The reasons underlying the discrepancy between the first and the subsequent studies could include nutritional strategy (amount of calories provided, use of parenteral nutrition), case-mix, potential differences in the optimal blood glucose level (BG) in different types of patients, hypoglycemia and its correction, and the magnitude of glucose variability. Therefore, an improved understanding of the physiology and pathophysiology of glycemic regulation during acute illness is needed. Safe and effective glucose control will need improvement in the definition of optimal BG and in the measurement techniques, perhaps including continuous monitoring of insulin algorithms and closed-loop systems. PMID:23075589

  11. Analysis of FTO Gene Variants with Measures of Obesity and Glucose Homeostasis in the IRAS Family Study

    OpenAIRE

    Wing, Maria R; Ziegler, Julie; Langefeld, Carl D; Ng, Maggie CY; Haffner, Steven M; Norris, Jill M; Goodarzi, Mark O; Bowden, Donald W

    2009-01-01

    Multiple studies have identified FTO gene variants associated with measures of adiposity in European-derived populations. The study objective was to determine whether FTO variants were associated with adiposity, including visceral and subcutaneous adipose tissue (VAT; SAT), and glucose homeostasis measures in the Insulin Resistance Atherosclerosis Family Study (IRASFS). A total of 27 SNPs in FTO intron 1, including SNPs prominent in the literature (rs9939609, rs8050136, rs1121980, rs17817449,...

  12. Measurement of glucose metabolism in patients with dilated cardiomyopathy using positron emission tomography with 18F-FDG: Initial Experience

    International Nuclear Information System (INIS)

    Introduction: Fluorine18 deoxyglucose (18F-FDG) has been used in numerous studies to determine the cardiac rate of glucose metabolism in normal and pathological conditions. It is known that during heart failure the metabolic pattern is altered. Patlack's graphical analysis allows the assessment of heart muscle glucose consumption in patients with non-ischaemic heart failure and normal subjects. Methods: Standardized measurement of glucose metabolism was performed in four patients with dilated cardiomyopathy and three healthy subjects. All subjects received an oral load of carbohydrates (75gr) previous to scanning. Dynamic images of the thorax were acquired. Myocardial uptake was estimated from time-activity curves in the atrium and left ventricle using Patlack's graphical analysis. Results: All subjects studied were male. 18F-FDG uptake rate for the group with dilated cardiomyopathy was 1.31±0.2, versus 1.26±0.37 ml/100gr/min in the control group. Conclusion: Measurement of cardiac glucose metabolism by 18F-FDG PET is feasible in a clinical service, allowing impact evaluation of physiologic and metabolic changes in the myocardium in different pathologic scenarios in addition to therapy assessment

  13. Effects of Zinc Supplementation on the Anthropometric Measurements, Lipid Profiles and Fasting Blood Glucose in the Healthy Obese Adults

    Directory of Open Access Journals (Sweden)

    Sepide Mahluji

    2013-02-01

    Full Text Available Purpose: The aim of this study was to assess the effects of zinc supplementation on anthropometric measures, improving lipid profile biomarkers, and fasting blood glucose level in obese people. Methods: This randomized, double- blind clinical trial was carried out on 60 obese participants in the 18-45 age range for one month. The participants were randomly divided into the intervention group, who received 30 mg/d zinc gluconate, and the placebo group who received 30mg/d starch. Anthropometric measurements (body mass index (BMI, weight and waist circumference were recorded before and at the end of study. Lipid profile biomarkers and fasting blood glucose were determined using enzymatic procedure. Analysis of Covariance (ANCOVA test was run to compare the post-treatment values of the two groups, and t-test was conducted to compare within group changes. Results: Serum zinc concentration was increased significantly in intervention group (p=0.024. BMI and body weight was significantly decreased (p=0.030 and p=0.020, respectively. Lipid profile biomarkers and fating blood glucose did not change significantly but triglyceride level was significantly decreased (p=0.006 in the intervention group. Conclusion: The obtained results indicate that zinc supplementation improves BMI, body weight, and triglyceride concentration without considerable effects on lipid profile and glucose level. Zinc can be suggested as a suitable supplementation therapy for obese people, but more studies are needed to verify the results.

  14. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Rumsey, J.M.; Duara, R.; Grady, C.; Rapoport, J.L.; Margolin, R.A.; Rapoport, S.I.; Cutler, N.R.

    1985-05-01

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions.

  15. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    International Nuclear Information System (INIS)

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions

  16. Upconverting phosphors as an amplifier of a colorimetric signal in dry chemistry test strips for enzymatic measurement of glucose

    Science.gov (United States)

    Valta, Timo; Horn, Carina

    2015-09-01

    We describe the use of upconverting phosphors (UCPs) as an amplifier of the colorimetric signal in enzymatic dry chemistry test strips for the determination of glucose. The indicator compound used in the strips attenuated both the emission and excitation wavelengths of the upconverting phosphors, thus taking advantage of the nonlinear relationship between the excitation and emission of these particles. By monitoring the emission of the UCPs under 978?nm excitation, we were able to obtain significantly higher signal response (a steeper calibration curve) from the colorimetric assay compared to a reflectance measurement. The limit of detection of the developed method was 2.1-fold lower than the reflectance-based reference method. The new method was able to determine glucose from a sample of water in the range of 5.7??M to 22?mM, which covers the typical blood glucose range in newborns and adults. In low analyte concentrations we obtained up to 3-fold improvement in the slope of the assay calibration curve. This difference decreased with increasing analyte concentration and the effect was diminished by the highest glucose concentration. However, the analytical sensitivity (the ratio of slope and standard deviation) was practically identical between the two methods because of the higher deviation in the UCP emission signal.

  17. Self-monitoring of blood glucose measurements and glycaemic control in a managed care paediatric type 1 diabetes practice

    Scientific Electronic Library Online (English)

    B, Davey; D G, Segal.

    2015-05-01

    Full Text Available BACKGROUND: Intensive diabetes management requires intensive insulin treatment and self-monitoring of blood glucose (SMBG) measurements to obtain immediate information on the status of the blood glucose level and to obtain data for pattern analysis on which meal planning, insulin and lifestyle adjus [...] tments can be made. The value and optimal frequency of SMBGs are often questioned OBJECTIVES: To document the relationship between SMBG frequency and glycaemic control in a managed care paediatric type 1 diabetes practice METHODS: A retrospective analysis was performed on 141 managed care paediatric and adolescent patients over a 1-year period from 1 February 2010 to 30 January 2011. The patients were stratified according to their insulin regimen. The frequency of SMBG was analysed and glycaemic control measured by glycated haemoglobin (HbA1c RESULTS: A highly significant decrease (p

  18. Measurement of the thermal spectrum of Hawking radiation from analog horizon

    Energy Technology Data Exchange (ETDEWEB)

    Unruh, William [British Columbia University (Canada)

    2013-07-01

    Full text: In 1974 Hawking predicted that black holes should radiate thermal radiation with a temperature given by the geometry of the horizon. In 1980 I suggested that this was a far more universal phenomenon and applied to horizons in many other situations, In 2010 we at Univ of BC measured the spectrum of the quantum radiation from a horizon to surface waves in water flow, by measuring the amplification of waves which impinged on that horizon. The spectrum of the associated quantum noise was shown that it would be thermal and Temperature determined by the characteristics of the flow as expected from the above arguments. (author)

  19. Laser spectroscopic real time measurements of methanogenic activity under simulated Martian subsurface analog conditions

    Science.gov (United States)

    Schirmack, Janosch; Böhm, Michael; Brauer, Chris; Löhmannsröben, Hans-Gerd; de Vera, Jean-Pierre; Möhlmann, Diedrich; Wagner, Dirk

    2014-08-01

    On Earth, chemolithoautothrophic and anaerobic microorganisms such as methanogenic archaea are regarded as model organisms for possible subsurface life on Mars. For this reason, the methanogenic strain Methanosarcina soligelidi (formerly called Methanosarcina spec. SMA-21), isolated from permafrost-affected soil in northeast Siberia, has been tested under Martian thermo-physical conditions. In previous studies under simulated Martian conditions, high survival rates of these microorganisms were observed. In our study we present a method to measure methane production as a first attempt to study metabolic activity of methanogenic archaea during simulated conditions approaching conditions of Mars-like environments. To determine methanogenic activity, a measurement technique which is capable to measure the produced methane concentration with high precision and with high temporal resolution is needed. Although there are several methods to detect methane, only a few fulfill all the needed requirements to work within simulated extraterrestrial environments. We have chosen laser spectroscopy, which is a non-destructive technique that measures the methane concentration without sample taking and also can be run continuously. In our simulation, we detected methane production at temperatures down to -5 °C, which would be found on Mars either temporarily in the shallow subsurface or continually in the deep subsurface. The pressure of 50 kPa which we used in our experiments, corresponds to the expected pressure in the Martian near subsurface. Our new device proved to be fully functional and the results indicate that the possible existence of methanogenic archaea in Martian subsurface habitats cannot be ruled out.

  20. Measurement of Faraday rotation in twisted optical fiber using rotating polarization and analog phase detection

    International Nuclear Information System (INIS)

    We demonstrated phase modulation of rotating linearly polarized light by current-induced Faraday rotation in a single mode optical fiber and used the technique to measure the current in ZT-40M, a Reversed-Field Pinch. We have also demonstrated the practicality of using twisted sensing fiber to overcome the problems associated with linear birefringence

  1. Photoelectric Emission Measurements on the Analogs of Individual Cosmic Dust Grains

    Science.gov (United States)

    Abbas, M. M.; Tankosic, D.; Craven, P. D.; Spann, J. F.; LeClair, A.; West, E. A.; Weingartner, J. C.; Tielens, A. G. G. M.; Nuth, J. a.; Camata, R. P.

    2006-01-01

    The photoelectric emission process is considered to be the dominant mechanism for charging of cosmic dust grains in many astrophysical environments. The grain charge and equilibrium potentials play an important role in the dynamical and physical processes that include heating of the neutral gas in the interstellar medium, coagulation processes in the dust clouds, and levitation and dynamical processes in the interplanetary medium and planetary surfaces and rings. An accurate evaluation of photoelectric emission processes requires knowledge of the photoelectric yields of individual dust grains of astrophysical composition as opposed to the values obtained from measurements on flat surfaces of bulk materials, as it is generally assumed on theoretical considerations that the yields for the small grains are much different from the bulk values. We present laboratory measurements of the photoelectric yields of individual dust grains of silica, olivine, and graphite of approx. 0.09-5 micrometer radii levitated in an electrodynamic balance and illuminated with ultraviolet radiation at 120-160 nm wavelengths. The measured yields are found to be substantially higher than the bulk values given in the literature and indicate a size dependence with larger particles having order-of-magnitude higher values than for submicron-size grains.

  2. In vivo cardiac glucose metabolism in the high-fat fed mouse: Comparison of euglycemic–hyperinsulinemic clamp derived measures of glucose uptake with a dynamic metabolomic flux profiling approach

    International Nuclear Information System (INIS)

    Rationale: Cardiac metabolism is thought to be altered in insulin resistance and type 2 diabetes (T2D). Our understanding of the regulation of cardiac substrate metabolism and insulin sensitivity has largely been derived from ex vivo preparations which are not subject to the same metabolic regulation as in the intact heart in vivo. Studies are therefore required to examine in vivo cardiac glucose metabolism under physiologically relevant conditions. Objective: To determine the temporal pattern of the development of cardiac insulin resistance and to compare with dynamic approaches to interrogate cardiac glucose and intermediary metabolism in vivo. Methods and results: Studies were conducted to determine the evolution of cardiac insulin resistance in C57Bl/6 mice fed a high-fat diet (HFD) for between 1 and 16 weeks. Dynamic in vivo cardiac glucose metabolism was determined following oral administration of [U-13C] glucose. Hearts were collected after 15 and 60 min and flux profiling was determined by measuring 13C mass isotopomers in glycolytic and tricarboxylic acid (TCA) cycle intermediates. Cardiac insulin resistance, determined by euglycemic–hyperinsulinemic clamp, was evident after 3 weeks of HFD. Despite the presence of insulin resistance, in vivo cardiac glucose metabolism following oral glucose administration was not compromised in HFD mice. This contrasts our recent findings in skeletal muscle, where TCA cycle activity was reduced in mice fed a HFD. Similar to our report in muscle, glucose derived pyruvate entry into the TCA cycle in the heart was almost exclusively via pyruvate dehydrogenase, with pyruvate carboxylase mediated anaplerosis being negligible after oral glucose administration. Conclusions: Under experimental conditions which closely mimic the postprandial state, the insulin resistant mouse heart retains the ability to stimulate glucose metabolism. - Highlights: • Insulin clamp was used to determine the evolution of cardiac insulin resistance. • Clamp measures were compared to a dynamic metabolomics approach. • The clamp revealed the presence of cardiac insulin resistance after 3 weeks of HFD. • Cardiac glucose metabolism was not affected by HFD during an oral glucose challenge

  3. The effects of precision, haematocrit, pH and oxygen tension on point-of-care glucose measurement in critically ill patients: a prospective study.

    OpenAIRE

    Watkinson, PJ; Barber, VS; Amira, E; James, T.; TAYLOR, R.; Young, JD

    2012-01-01

    BACKGROUND: Critical care glycaemic control protocols commonly have treatment adjustment (target) ranges spanning ?2 mmol/L. These require precise point-of-care glucose measurement, unaffected by other variables, to avoid measurement errors increasing glycaemic variability and hypoglycaemic episodes (both strongly associated with mortality in critically ill patients). METHODS: A prospective 206 intensive care patient study was carried out. Arterial glucose concentrations were measured in dupl...

  4. Experimentally Measured Interfacial Area during Gas Injection into Saturated Porous Media: An Air Sparging Analogy

    Energy Technology Data Exchange (ETDEWEB)

    Crandall, Dustin; Ahmadi, Goodarz; Smith, Duane H., Bromhal, Grant

    2010-01-01

    The amount of interfacial area (awn) between air and subsurface liquids during air-sparging can limit the rate of site remediation. Lateral movement within porous media could be encountered during air-sparging operations when air moves along the bottom of a low-permeability lens. This study was conducted to directly measure the amount of awn between air and water flowing within a bench-scale porous flow cell during the lateral movement of air along the upper edge of the cell during air injections into an initially water-saturated flow cell. Four different cell orientations were used to evaluate the effect of air injection rates and porous media geometries on the amount of awn between fluids. Air was injected at flow rates that varied by three orders of magnitude, and for each flow cellover this range of injection rates little change in awn was noted. A wider variation in awn was observed when air moved through different regions for the different flow cell orientations. These results are in good agreement with the experimental findings of Waduge et al. (2007), who performed experiments in a larger sand-pack flow cell, and determined that air-sparging efficiency is nearly independent of flow rate but highly dependent on the porous structure. By directly measuring the awn, and showing that awn does not vary greatly with changes in injection rate, we show that the lack of improvement to remediation rates is because there is a weak dependence of the awn on the air injection rate.

  5. Associations between insulin and glucose concentrations and anthropometric measures of fat mass in Australian adolescents

    OpenAIRE

    Denney-Wilson Elizabeth; Cowell Christopher T; Okely Anthony D; Hardy Louise L; Aitken Robert; Dobbins Timothy

    2010-01-01

    Abstract Background One of the most serious, yet common co-morbidities of obesity is insulin resistance, which if untreated may progress to type 2 diabetes. This paper describes the insulin and glucose concentration distributions, the prevalence of elevated insulin, the associations between insulin and body mass index (BMI), waist circumference, waist-to-height ratio (WHtR) and fat mass index in a representative sample of Australian adolescents. Methods Cross-sectional population-based study ...

  6. Demonstration of remote optical measurement configuration that correlates to glucose concentration in blood

    OpenAIRE

    Beiderman, Yevgeny; Blumenberg, Raz; Rabani, Nir; Teicher, Mina; Garcia, Javier; Mico, Vicente; Zalevsky, Zeev

    2011-01-01

    An optical approach allowing the extraction and the separation of remote vibration sources has recently been proposed. The approach has also been applied for medical related applications as blood pressure and heart beats monitoring. In this paper we demonstrate its capability to monitor glucose concentration in blood stream. The technique is based on the tracking of temporal changes of reflected secondary speckle produced in human skin (wrist) when being illuminated by a laser beam. A tempora...

  7. Analog multivariate counting analyzers

    CERN Document Server

    Nikitin, A V; Armstrong, T P

    2003-01-01

    Characterizing rates of occurrence of various features of a signal is of great importance in numerous types of physical measurements. Such signal features can be defined as certain discrete coincidence events, e.g. crossings of a signal with a given threshold, or occurrence of extrema of a certain amplitude. We describe measuring rates of such events by means of analog multivariate counting analyzers. Given a continuous scalar or multicomponent (vector) input signal, an analog counting analyzer outputs a continuous signal with the instantaneous magnitude equal to the rate of occurrence of certain coincidence events. The analog nature of the proposed analyzers allows us to reformulate many problems of the traditional counting measurements, and cast them in a form which is readily addressed by methods of differential calculus rather than by algebraic or logical means of digital signal processing. Analog counting analyzers can be easily implemented in discrete or integrated electronic circuits, do not suffer fro...

  8. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

    Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

  9. Analog circuits cookbook

    CERN Document Server

    Hickman, Ian

    2013-01-01

    Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

  10. Spectroscopic imaging of blood vessels only near the skin surface for non-invasive blood glucose measurement

    Science.gov (United States)

    Fujiwara, Masaru; Sato, Shun; Abeygunawardhana, Pradeep K. W.; Suzuki, Satoru; Nishiyama, Akira; Wada, Kenji; Ishimaru, Ichiro

    2015-07-01

    To realize the non-invasive blood glucose measurement, it will be effective to acquire the spectroscopic imaging of blood vessels only near the skin surface for eliminating other biological-component's disturbances. Our proposed imaging-type 2-dimensional Fourier spectroscopic imaging can limit the measuring depth into focal plane with high light detection sensitivity. Thus, the proposed method will be suitable for measuring only near the skin surface with detecting weak reflected light from inner biomembrane. But reflectance of skin surface is more than 1000 times larger than inner skin's reflectance. Paying attention on Fresnel reflection, fingers what were illuminated by p-polarized beam from Brewster's angle were observed with crossed-Nicol dark field optics. We successfully acquired spectroscopic characteristics of hemoglobin at vein area near the skin surface.

  11. Measurements of urea and glucose in aqueous solutions with dual-beam near-infrared Fourier-transform spectroscopy

    DEFF Research Database (Denmark)

    Jensen, P.S.; Bak, J.

    2002-01-01

    This study investigates the use of a dual-beam, optical null, FT-IR spectrometer to measure trace organic components in aqueous solutions in the combination band region 5000-4000 cm(-1). The spectrometer may be used for both single- and dual-beam measurements, thereby facilitating comparison of...... these two modes of operation. The concentrations of aqueous solutions of urea and glucose in the ranges 0-40 mg/dL and 0-250 mg/dL, respectively, were determined by principal component regression using both modes. The dual-beam technique eliminated instrumental variations present in the single......-beam measurements that must be taken into account when quantifying trace components from single-beam spectra. The data obtained with the dual-beam technique resulted in more stable calibration models based on principal component regression. These calibration models need fewer factors and yield lower prediction...

  12. Glucose metabolism of fetal rat brain in utero, measured with labeled deoxyglucose

    International Nuclear Information System (INIS)

    Mammals have low cerebral metabolic rates immediately after birth and, by inference, also before birth. In this study, we extended the deoxyglucose method to the fetal rat brain in utero. Rate constants for deoxyglucose transfer across the maternal placental and fetal blood-brain barriers, and lumped constant, have not been reported. Therefore, we applied a new method of determining the lumped constant regionally to the fetal rat brain in utero. The lumped constant averaged 0.55 ± 0.15 relative to the maternal circulation. On this basis, we determined the glucose metabolic rate of the fetal rat brain to be one third of the corresponding maternal value, or 19 ± 2 ?mol hg-1 min-1. (author)

  13. Glucose Sensing

    CERN Document Server

    Geddes, Chris D

    2006-01-01

    Topics in Fluorescence Spectroscopy, Glucose Sensing is the eleventh volume in the popular series Topics in Fluorescence Spectroscopy, edited by Drs. Chris D. Geddes and Joseph R. Lakowicz. This volume incorporates authoritative analytical fluorescence-based glucose sensing reviews specialized enough to be attractive to professional researchers, yet also appealing to the wider audience of scientists in related disciplines of fluorescence. Glucose Sensing is an essential reference for any lab working in the analytical fluorescence glucose sensing field. All academics, bench scientists, and industry professionals wishing to take advantage of the latest and greatest in the continuously emerging field of glucose sensing, and diabetes care & management, will find this volume an invaluable resource. Topics in Fluorescence Spectroscopy Volume 11, Glucose Sensing Chapters include: Implantable Sensors for Interstitial Fluid Smart Tattoo Glucose Sensors Optical Enzyme-based Glucose Biosensors Plasmonic Glucose Sens...

  14. Effect of postprandial hyperglycaemia in non-invasive measurement of cerebral metabolic rate of glucose in non-diabetic subjects

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchida, Tatsuro; Itoh, Harumi [Department of Radiology, Fukui Medical University, Matsuoka (Japan); Sadato, Norihiro; Nishizawa, Sadahiko; Yonekura, Yoshiharu [Biomedical Imaging Research Center, Fukui Medical University (Japan)

    2002-02-01

    The aim of this study was to determine the effect of postprandial hyperglycaemia (HG) on the non-invasive measurement of cerebral metabolic rate of glucose (CMRGlc). Five patients who had a meal within an hour before a fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) examination were recruited in this study. They underwent intermittent arterial blood sampling (measured input function), and, based on this sampling, CMRGlc was calculated using an autoradiographic method (CMRGlc{sub real}). Simulated input functions were generated based on standardised input function, body surface area and net injected dose of FDG, and simulated CMRGlc (CMRGlc{sub sim}) was also calculated. Percent error of the area under the curve (AUC) between measured (AUC{sub real}) and simulated input function (AUC{sub IFsim}) and percent error between CMRGlc{sub real} and CMRGlc{sub sim} were calculated. These values were compared with those obtained from a previous study conducted under fasting conditions (F). The serum glucose level in the HG group was significantly higher than that in the F group (165{+-}69 vs 100{+-}9 mg/dl, P=0.0007). Percent errors of AUC and CMRGlc in grey matter and white matter in HG were significantly higher than those in F (12.9%{+-}1.3% vs 3.5%{+-}2.2% in AUC, P=0.0015; 18.2%{+-}2.2% vs 2.9%{+-}1.9% in CMRGlc in grey matter, P=0.0028; 24.0%{+-}4.6% vs 3.4%{+-}2.2% in CMRGlc in white matter, P=0.0028). It is concluded that a non-invasive method of measuring CMRGlc should be applied only in non-diabetic subjects under fasting conditions. (orig.)

  15. GLUCOSE ELECTROOXIDATION

    OpenAIRE

    PASTA, MAURO

    2010-01-01

    The electrooxidation of glucose has attracted a lot of interest due to its applications in blood glucose sensors and biological fuel cells. Glucose sensors optimization is highly necessary to improve the treatment of Diabetes Mellitus, a chronic disease affecting millions of people around the world, while biological fuel cells have been studied in order to explore new, renewable energy sources alternative to fossil fuels. There are three main ways to perform glucose electrooxidation, depen...

  16. Filtration of analog data measured on-line in automated control system of thermal and nuclear power plants

    International Nuclear Information System (INIS)

    Two approaches to additional filtration of analog data in automated control systems of thermal and nuclear power plants are considered. The algorithms studied were used for the development of data reliability control subsystem in automated control system of nuclear power plants

  17. Measurement of local glucose transport rate constant and free glucose pool in human brain using PET and CMG: First result in normals and Huntington patients

    International Nuclear Information System (INIS)

    Even in images reconstructed with the method of filtered backprojection it is possible to perform parametric images on a pixel by pixel base with use of appropriate stable algorithms. There is no doubt, that these analytical procedures are less efficient than the iterative ones, but they are doing well when relative values between pixels are of interest. The approach using a Lookup-Table was determined to be best and used in normals and Huntington patients. The first results show that in Huntington patients the transport of glucose is not regional affected, but globally reduced. Following studies on a large patient pool will challenge and proceed further this presented technique. (orig.)

  18. Associations between Ultrasound Measures of Abdominal Fat Distribution and Indices of Glucose Metabolism in a Population at High Risk of Type 2 Diabetes: The ADDITION-PRO Study

    DEFF Research Database (Denmark)

    Philipsen, Annelotte; JØrgensen, Marit E

    2015-01-01

    AIMS: Visceral adipose tissue measured by CT or MRI is strongly associated with an adverse metabolic risk profile. We assessed whether similar associations can be found with ultrasonography, by quantifying the strength of the relationship between different measures of obesity and indices of glucose metabolism in a population at high risk of type 2 diabetes. METHODS: A cross-sectional analysis of 1342 participants of the ADDITION-PRO study. We measured visceral adipose tissue and subcutaneous adipose tissue with ultrasonography, anthropometrics and body fat percentage by bioelectrical impedance. Indices of glucose metabolism were derived from a three point oral glucose tolerance test. Linear regression of obesity measures on indices of glucose metabolism was performed. RESULTS: Mean age was 66.2 years, BMI 26.9kg/m2, subcutaneous adipose tissue 2.5cm and visceral adipose tissue 8.0cm. All measures of obesity were positively associated with indicators of glycaemia and inversely associated with indicators of insulin sensitivity. Associations were of equivalent magnitude except for subcutaneous adipose tissue and the visceral/subcutaneous adipose tissue ratio, which showed weaker associations. One standard deviation difference in BMI, visceral adipose tissue, waist circumference, waist/height ratio and body fat percentage corresponded approximately to 0.2mmol/l higher fasting glucose, 0.7mmol/l higher 2-hr glucose, 0.06-0.1% higher HbA1c, 30 % lower HOMA index of insulin sensitivity, 20% lower Gutt's index of insulin sensitivity, and 100 unit higher Stumvoll's index of beta-cell function. After adjustment for waist circumference visceral adipose tissue was still significantly associated with glucose intolerance and insulin resistance, whereas there was a trend towards inverse or no associations with subcutaneous adipose tissue. After adjustment, a 1cm increase in visceral adipose tissue was associated with ~5% lower insulin sensitivity (p?0.0004) and ~0.18mmol/l higher 2-hr glucose (p?0.001). CONCLUSION: Visceral and subcutaneous adipose tissue assessed by ultrasonography are significantly associated with glucose metabolism, even after adjustment for other measures of obesity.

  19. Glucose effectiveness in nondiabetic relatives

    DEFF Research Database (Denmark)

    Egede, M B; Henriksen, J-E; Durck, T T; Levin, K; Rantzau, C; Ward, G; Beck-Nielsen, H; Alford, F P

    2014-01-01

    AIMS: Reduced glucose effectiveness is a predictor of future glucose tolerance in individuals with a family history of type 2 diabetes. We examined retrospectively at 10 years in normoglycemic relatives of diabetic subjects (RELs) the pathophysiological role of glucose effectiveness in the...... development of isolated impaired fasting glucose, glucose intolerance, and acute insulin release. METHODS: At 0 years, 19 RELs and 18 matched control subjects had glucose effectiveness (GE), insulin sensitivity, acute insulin release (AIR)IVGTT, and disposition index measured during an iv glucose tolerance...... test (IVGTT), using the minimal model analysis. At 0 and 10 years, oral glucose tolerance (OGTT) and AIROGTT were determined. RESULTS: At 0 years, fasting glucose (FG) and GE were raised in RELs, but insulin sensitivity and AIROGTT were reduced (P ? .05) compared with controls. At 10 years, RELs...

  20. Synthesis and anticancer activity of new flavonoid analogs and inconsistencies in assays related to proliferation and viability measurements

    OpenAIRE

    FORBES, ALAINA M.; LIN, HUIMIN; Meadows, Gary G.; MEIER, G. PATRICK

    2014-01-01

    Flavonoids have been studied intensely for their ability to act as anti-carcinogenic, anti-inflammatory, anti-viral and anti-aging agents and are often marketed as supplements related to their anti-inflammatory activity. Previous studies have primarily focused on the effects of polar natural flavonoids. We examined the activity of novel hydrophobic and lipophilic flavonols against human DU-145 and PC-3 prostate cancer cell lines. All flavonol analogs were more active than the naturally occurr...

  1. Low-power adaptive control scheme using switching activity measurement method for reconfigurable analog-to-digital converters

    OpenAIRE

    Ab Razak, Mohd Zulhakimi

    2014-01-01

    Power consumption is a critical issue for portable devices. The ever-increasing demand for multimode wireless applications and the growing concerns towards power-aware green technology make dynamically reconfigurable hardware an attractive solution for overcoming the power issue. This is due to its advantages of flexibility, reusability, and adaptability. During the last decade, reconfigurable analog-to-digital converters (ReADCs) have been used to support multimode wireless applications. Wit...

  2. An Analog Front-End and ADC Integrated Circuit for Implantable Force and Orientation Measurements in Joint Prosthesis

    OpenAIRE

    GODARA, Balwant; Nikita, Konstantina S; Tanner, Steve; Ali, Shafqat; Banjevic, Mirjana; Arami, Arash; Aminian, Kamiar; Hasenkamp, Willyan; Bertsch, Arnaud; Renaud, Philippe; Farine, Pierre-André

    2013-01-01

    The paper presents an analogue front-end and ADC integrated circuit for processing signals of sensors implanted into joint prosthesis. The circuit is designed to be operated with Wheatstone bridge sensors, such as strain gauges, pressure, Hall Effect, magneto-resistive sensors, etc. It performs sensor supply multiplexing, sensor signal amplification with chopper modulation, offset compensation and 14-bit analog to digital conversion in a single chip. It can operate simultaneously up to eight ...

  3. Controlled Measurement and Comparative Analysis of Cellular Components in E. coli Reveals Broad Regulatory Changes in Response to Glucose Starvation

    Science.gov (United States)

    Houser, John R.; Barnhart, Craig; Boutz, Daniel R.; Carroll, Sean M.; Dasgupta, Aurko; Michener, Joshua K.; Needham, Brittany D.; Papoulas, Ophelia; Sridhara, Viswanadham; Sydykova, Dariya K.; Marx, Christopher J.; Trent, M. Stephen; Barrick, Jeffrey E.; Marcotte, Edward M.; Wilke, Claus O.

    2015-01-01

    How do bacteria regulate their cellular physiology in response to starvation? Here, we present a detailed characterization of Escherichia coli growth and starvation over a time-course lasting two weeks. We have measured multiple cellular components, including RNA and proteins at deep genomic coverage, as well as lipid modifications and flux through central metabolism. Our study focuses on the physiological response of E. coli in stationary phase as a result of being starved for glucose, not on the genetic adaptation of E. coli to utilize alternative nutrients. In our analysis, we have taken advantage of the temporal correlations within and among RNA and protein abundances to identify systematic trends in gene regulation. Specifically, we have developed a general computational strategy for classifying expression-profile time courses into distinct categories in an unbiased manner. We have also developed, from dynamic models of gene expression, a framework to characterize protein degradation patterns based on the observed temporal relationships between mRNA and protein abundances. By comparing and contrasting our transcriptomic and proteomic data, we have identified several broad physiological trends in the E. coli starvation response. Strikingly, mRNAs are widely down-regulated in response to glucose starvation, presumably as a strategy for reducing new protein synthesis. By contrast, protein abundances display more varied responses. The abundances of many proteins involved in energy-intensive processes mirror the corresponding mRNA profiles while proteins involved in nutrient metabolism remain abundant even though their corresponding mRNAs are down-regulated. PMID:26275208

  4. On-line measurements of oscillating mitochondrial membrane potential in glucose-fermenting Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Andersen, Ann Zahle; Poulsen, Allan K; Olsen, Lars Folke; Brasen, Jens Christian

    2007-01-01

    We employed the fluorescent cyanine dye DiOC(2)(3) to measure membrane potential in semi-anaerobic yeast cells under conditions where glycolysis was oscillating. Oscillations in glycolysis were studied by means of the naturally abundant nicotinamide adenine dinucleotide (NADH). We found that the...

  5. On-line measurements of oscillating mitochondrial membrane potential in glucose-fermenting Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Andersen, Ann Zahle; Poulsen, Allan K; Olsen, Lars Folke; Brasen, Jens Christian

    2007-01-01

    We employed the fluorescent cyanine dye DiOC(2)(3) to measure membrane potential in semi-anaerobic yeast cells under conditions where glycolysis was oscillating. Oscillations in glycolysis were studied by means of the naturally abundant nicotinamide adenine dinucleotide (NADH). We found that the mitochondrial membrane potential was oscillating, and that these oscillations displayed the same frequency and duration as the NADH oscillations. It was confirmed that DiOC(2)(3) localizes itself in the ...

  6. Measurement of regional cerebral metabolic rate for glucose in the human subject with (F-18)-2-deoxy-2-fluoro-d-glucose and emission computed tomography: validation of the method

    International Nuclear Information System (INIS)

    Tracer techniques and models of in vitro quantitative autoradiography and tissue counting for the measure of regional metabolic rates (rMR) are combined with emission computed tomography (ECT). This approach, Physiologic Tomography (PT), provides atraumatic and analytical measurements of rMR. PT is exemplified with the regional measurement of the cerebral metabolic rate for glucose (CMRGlu) in man with (18F)-2-deoxy-2-fluoro-D-glucose (FDG) and positron ECT. Our model incorporates a k4* mediated hydrolysis of FDG-6-PO4 to FDG which then competes with phosphorylation (k3*) of FDG back to FDG-6-PO4 and reverse transport (k2*) back to blood. Although small, k4* is found to be significant. The ECAT positron tomograph was used to measure the rate constants (k1*?k4*), lumped constant (LC), stability, and reproducibility of the model in man. Since these parameters have not been measured for FDG in any species, comparisons are made to values for DG in rat and monkey. Compartmental concentrations of FDG and FDG-6-PO4 were determined and show that cerebral FDG-6-PO4 steadily accumulates for about 100 mins, plateaus and then slowly decreases due to hydrolysis. Cerebral blood FDG concentration was determined to be a minor contribution to tissue activity after 10 min. Regional CMRGlu measurements are reproducible to +- 5.5% over 5 hrs. PT allows the in vivo study ofregional biochemistry and physiology in normal and pathophysiologic states in man with a unique and fundamental capability

  7. Correlation of fasting blood glucose and haemoglobin A1c measured with an automated analyser

    OpenAIRE

    Furota, Akira; Miyagawa, Teikichi; Tsuda, Izumi; Tatsumi, Noriyuki

    1990-01-01

    A subtype of glycohaemoglobin, haemoglobin (Hb) A1c, in specimens of whole blood was assayed on a new automated analyser that makes use of high-pressure liquid chromatography. The analyser provided precise and reproducible values. The mean of the HbA1c values was lower than that with an older instrument. The mean tended to increase with the age of the subjects, who were undergoing routine health examinations. No sex difference was found. When measurement was made 1 h after the subjects drank ...

  8. Glucose Tests

    Science.gov (United States)

    ... blood glucose. In a person with signs and symptoms of diabetes or hyperglycemia , a non-fasting glucose level (random blood sample) ... to trauma, heart attack , and stroke for instance) Chronic kidney ... nervous system symptoms (sweating, palpitations, hunger, trembling, and anxiety), then begins ...

  9. The Usefulness of Homeostatic Measurement Assessment-Insulin Resistance (HOMA-IR) for Detection of Glucose Intolerance in Thai Women of Reproductive Age with Polycystic Ovary Syndrome.

    Science.gov (United States)

    Wongwananuruk, Thanyarat; Rattanachaiyanont, Manee; Leerasiri, Pichai; Indhavivadhana, Suchada; Techatraisak, Kitirat; Angsuwathana, Surasak; Tanmahasamut, Prasong; Dangrat, Chongdee

    2012-01-01

    Objectives. To study the cut-off point of Homeostatic Measurement Assessment-Insulin Resistance (HOMA-IR) as a screening test for detection of glucose intolerance in Thai women with polycystic ovary syndrome (PCOS). Study Design. Cross-sectional study. Setting. Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital. Subject. Two hundred and fifty Thai PCOS women who attended the Gynecologic Endocrinology Unit, during May 2007 to January 2009. Materials and Methods. The paitents were interviewed and examined for weight, height, waist circumference, and blood pressure. Venous blood samples were drawn twice, one at 12-hour fasting and the other at 2 hours after glucose loading. Results. The prevalence of glucose intolerance in Thai PCOS women was 20.0%. The mean of HOMA-IR was 3.53? ± ?7.7. Area under an ROC curve for HOMA-IR for detecting glucose intolerance was 0.82. Using the cut-off value of HOMA-IR >2.0, there was sensitivity at 84.0%, specificity at 61.0%, positive predictive value at 35.0%, negative predictive value at 93.8%, and accuracy at 65.6%. Conclusion. HOMA-IR >2.0 was used for screening test for glucose intolerance in Thai PCOS women. If the result was positive, a specific test should be done to prove the diagnosis. PMID:22737168

  10. In vivo measurements of whole body (WB) and skeletal muscle glucose metabolism under basal and euglycemic insulin clamp (Clamp) by combined PET and stable isotope (SI) tracer studies

    International Nuclear Information System (INIS)

    Aim/Background: Primed-constant infusion of SI labeled tracers is a classic technique for studying metabolism at the WB level, however, this procedure provides no information about the metabolism of specific tissues. In contrast PET provides primarily tissue specific data. In this study, we combined PET with SI techniques to measure glucose metabolism in WB and lower limb skeletal muscle (LLM) of humans under Basal and Clamp conditions. Methods and Materials: Four healthy volunteers (73.0 ± 6.0 kg, mean ± sem) were studied. After fasting overnight, each subject was injected with 10 mCi of 18FDG and serial 1.0 min. PET images of the mid-thigh region were acquired over 90 min. Arterial blood samples were collected in parallel. Glucose metabolic rate (GM) was calculated with a 3-compartment / 4 rate constant model; LC assumed to be 1.0. A primed constant infusion of [6,6, 2H2]glucose was performed in parallel with the PET measurements. On another day, the PET and SI measurements were repeated under clamp conditions. All results are expressed as mean ± sem. Results: The glucose kinetics in whole body and in low limb skeletal muscles are shown. Under in vivo conditions, Clamp caused: 1) a 10.2 ± 2.3 fold increase in GM by LLM but only a 4.7 ± 0.4 fold increase in GM by MB. 2) Increased contribution of LLM to WB GM, indicating that LLM GM is more sensitive to insulin compared with anterior LLM (extensors). Discussion: The study demonstrated the unique advantages of using PET to study substrate metabolism in specific tissues in human subjects: i) It is less invasive than the conventional A-V difference and muscle biopsy method. ii) It provides a more detailed picture of substrate metabolism in different parts of the muscle in the same limb, as compared to one spot muscle biopsy. Data in demonstrated that GM in posterior LLM is more sensitive to insulin than that in anterior LLM. iii) It can detect substrate metabolism in deep muscles which cannot be reached by biopsy technique. Therefore PET combined with stable isotope tracer can non-invasively provide a more complete in vivo picture of glucose metabolism in WB and in different parts of the skeletal muscles in human subjects. Conclusions: 1. Euglycemic insulin clamp (EGIC) caused a significant suppress of endogenous glucose production, either released from glycogenolysis or gluconeogenesis in the fasting condition. 2. Glucose metabolism in LLM is more sensitively regulated by insulin than other tissues. 3. On the same lower limb, glucose metabolism posterior muscle group is more sensitively regulated by insulin than those in the anterior. (author)

  11. An Implantable RFID Sensor Tag toward Continuous Glucose Monitoring.

    Science.gov (United States)

    Xiao, Zhibin; Tan, Xi; Chen, Xianliang; Chen, Sizheng; Zhang, Zijian; Zhang, Hualei; Wang, Junyu; Huang, Yue; Zhang, Peng; Zheng, Lirong; Min, Hao

    2015-05-01

    This paper presents a wirelessly powered implantable electrochemical sensor tag for continuous blood glucose monitoring. The system is remotely powered by a 13.56-MHz inductive link and utilizes an ISO 15693 radio frequency identification (RFID) standard for communication. This paper provides reliable and accurate measurement for changing glucose level. The sensor tag employs a long-term glucose sensor, a winding ferrite antenna, an RFID front-end, a potentiostat, a 10-bit sigma-delta analog to digital converter, an on-chip temperature sensor, and a digital baseband for protocol processing and control. A high-frequency external reader is used to power, command, and configure the sensor tag. The only off-chip support circuitry required is a tuned antenna and a glucose microsensor. The integrated chip fabricated in SMIC 0.13-μm CMOS process occupies an area of 1.2 mm ×2 mm and consumes 50 μW. The power sensitivity of the whole system is -4 dBm. The sensor tag achieves a measured glucose range of 0-30 mM with a sensitivity of 0.75 nA/mM. PMID:25823049

  12. Glucose Dependency of the Metabolic Pathway of HEK 293 Cells Measured by a Flow-through Type pH/CO2 Sensor System Using ISFETs

    Science.gov (United States)

    Yamada, Akira; Mohri, Satoshi; Nakamura, Michihiro; Naruse, Keiji

    Our group previously reported the application of a flow-through type pH/CO2 sensor system designed to evaluate the metabolic activity of cultured cells. The sensor system consists of two ion-sensitive field effect transistors (ISFETs), an ISFET to measure the total pH change and an ISFET enclosed within a gas-permeable silicone tube to measure the pH change attributable to CO2. In that study, we used the system to quantitatively analyze metabolic switching induced by glucose concentration changes in three cultured cell types (bovine arterial endothelium cell (BAEC), human umbilical vein endothelium cell (HUVEC), and rat cardiomuscle cell (RCMC)), and to measure the production rates of total carbonate and free lactic acid in the cultured cells. In every cell type examined, a decrease in the glucose concentration led to an increase in total carbonate, a product of cellular respiration, and a decrease of free lactic acid, a product of glycolysis. There were very significant differences among the cell types, however, in the glucose concentrations at the metabolic switching points. We postulated that the cell has a unique switching point on the metabolic pathway from glycolysis to respiration. In this paper we use our sensor system to evaluate the metabolic switching of human embryonic kidney 293 cells triggered by glucose concentration changes. The superior metabolic pathway switched from glycolysis to respiration when the glucose concentration decreased to about 2 mM. This result was very similar to that obtained in our earlier experiments on HUVECs, but far different from our results on the other two cells types, BAECs and RCMCs. This sensor system will be useful for analyzing cellular metabolism for many applications and will yield novel information on different cell types.

  13. Glucose allostasis

    DEFF Research Database (Denmark)

    Stumvoll, Michael; Tataranni, P Antonio; Stefan, Norbert; Vozarova, Barbora; Bogardus, Clifton; de Courten, Barbora

    2003-01-01

    In many organisms, normoglycemia is achieved by a tight coupling of nutrient-stimulated insulin secretion in the pancreatic beta-cell (acute insulin response [AIR]) and the metabolic action of insulin to stimulate glucose disposal (insulin action [M]). It is widely accepted that in healthy individuals with normal glucose tolerance, normoglycemia can always be maintained by compensatorily increasing AIR in response to decreasing M (and vice versa). This has been mathematically described by the hy...

  14. A CAMAC unit for charge measuring and pulse shape recording based on a fast, 8-bit parallel analog-to-digital converter

    International Nuclear Information System (INIS)

    A device designed mainly for measuring systems for testing parameters of some type of detectors used in the high energy physics is described. The device is one-module CAMAC unit. It is equipped in a fast, 8-bit parallel analog-to-digital converter ''flash''type with a gated integrator at the input and a static RAM (4096 x 8 bit) at the output. The device enables measurements of the charge in pulses from detectors or registration of the shape of these pulses. The construction, operation and parameters of the circuits of the device are described and the way of programming functions using CAMAC dataway is given. 8 refs., 9 figs. (author)

  15. Measurement of SFDR and noise in EDF amplified analog RF links using all-optical down-conversion and balanced receivers

    Science.gov (United States)

    Middleton, Charles; Borbath, Michael; Wyatt, Jeff; DeSalvo, Richard

    2008-04-01

    Optical down-conversion techniques have become an increasingly popular architecture to realize Multi-band Enterprise Terminals (MET), Synthetic Aperture Radar (SAR), Optical Arbitrary Waveform Generation (OAWG), RF Channelizers and other technologies that need rapid frequency agile tunability in the microwave and millimeter RF bands. We describe recent SFDR, NF, Gain, and Noise modeling and measurements of Erbium-doped-fiber amplified analog RF optical links implementing all-optical down-conversion and balanced photodiode receivers. We describe measurements made on our newly designed extensive test-bed utilizing a wide array of high powered single and balanced photodiodes, polarization preserving output LN modulators, EAMs, LIMs, tunable lasers, EDFAs, RF Amplifiers, and other components to fully characterize direct and coherent detection techniques. Additionally, we compare these experimental results to our comprehensive MATLAB system modeling and optimization software tools.

  16. The Usefulness of Homeostatic Measurement Assessment-Insulin Resistance (HOMA-IR) for Detection of Glucose Intolerance in Thai Women of Reproductive Age with Polycystic Ovary Syndrome

    OpenAIRE

    Prasong Tanmahasamut; Surasak Angsuwathana; Kitirat Techatraisak; Suchada Indhavivadhana; Pichai Leerasiri; Manee Rattanachaiyanont; Thanyarat Wongwananuruk; Chongdee Dangrat

    2012-01-01

    Objectives. To study the cut-off point of Homeostatic Measurement Assessment-Insulin Resistance (HOMA-IR) as a screening test for detection of glucose intolerance in Thai women with polycystic ovary syndrome (PCOS). Study Design. Cross-sectional study. Setting. Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital. Subject. Two hundred and fifty Thai PCOS women who attended the Gynecologic Endocrinology Unit, during May 2007 to January 2009. Materials and Methods. The ...

  17. Measurement of muscle and whole body (WB) glucose metabolism (GM) in vivo by combined stable isotope (SI) and PET techniques - Validation in an animal model

    International Nuclear Information System (INIS)

    Aim/Background: Primed-constant infusion of SI labeled tracers is a classic technique for studying metabolism at the WB level, however, without invasive A-V difference data it provides no information about the metabolism of specific tissues. In contrast PET provides primarily tissue specific data. The aim of this study is to apply PET in combination with SI methods in an animal to simultaneously quantify substrate metabolism in specific tissues and the WB. Methods and materials: Animals: Seven white New Zealand rabbits (Mean ± SE 3.7 ± 0.1 kg;) were studied. After 14 hours of fast, they were surgically prepared by tracheotomy and implantation of catheters into carotid artery (Ca), jugular vein (Jv), and right femoral vein (Fv) under anesthesia. PET Imaging: The animal was placed in supine position in the gantry of a PC-4096 PET camera. Transmission images (5 min.) with a rotating pin source containing fib 68Ge were acquired with the central tomographic slice positioned to include both hind limbs (HLs). Each animal received C15O2 inhalation and was imaged for blood flow (BE) rate in HL muscles. Then, 18FDG (? 8 mCi) was injected into the animal through jugular vein, followed by serial PET images of muscle glucose metabolism (GM) for 90 min. Primed constant infusion of [6,6, 2H]-glucose (0.8?mol/kg/min, priming 64umol/kg) was conducted simultaneously. Plateau level blood samples were taken from the Ca and Fv for WB and HL GM. Stable Isotope Measurements: The whole body glucose metabolic rate and the plasma glucose kinetics are calculated according to the conventional stable isotope steady state kinetics model. Q=i(E,/EP-l) where i is the infusion rate of stable isotope labeled [6,6, 2H2]-glucose, E1 and EP are the isotopic enrichments of [6,6, 2H2]-glucose in infusate and plasma under steady state conditions. The hind limb glucose metabolism was also measured using stable isotope tracer and tracee difference across the hind limb. WB GM determined by SI was 2.54 ± 0.22 mg/kg/min and GM in the right HL measured by A-V difference of ST was 0.77 ± 0.12 mg/leg/min. Based on muscle mass in HL (199 ± 7.8 g), LM GM (?g/g tissue/min) was calculated to be 3.40 ± 0.46 by St and 3.64 ± 0.22 by PET (N.S; paired t-test). BF to HL muscle determined by C15O2 inhalation was 0.059 ± 0.01 ml/g tissue/min. Discussion: The two in vivo methods provided comparable quantitative information on muscle protein metabolism. PET measurements have the advantage of less invasive than A-V difference methods using SI, but it does not provide the information on whole body glucose disposal rate. Therefore combined SI and PET would provide more complete picture of whole body and regional glucose metabolism in vivo. Conclusions: PET-ST is a non-invasive approach to simultaneously quantify WB and muscle GM without biopsy, hence a powerful tool for human studies under various physio-pathophysiological conditions. (author)

  18. Predicting Plasma Glucose From Interstitial Glucose Observations Using Bayesian Methods

    DEFF Research Database (Denmark)

    Hansen, Alexander Hildenbrand; Duun-Henriksen, Anne Katrine; Juhl, Rune; Schmidt, Signe; Nørgaard, Kirsten; Jørgensen, John Bagterp; Madsen, Henrik

    2014-01-01

    One way of constructing a control algorithm for an artificial pancreas is to identify a model capable of predicting plasma glucose (PG) from interstitial glucose (IG) observations. Stochastic differential equations (SDEs) make it possible to account both for the unknown influence of the continuous glucose monitor (CGM) and for unknown physiological influences. Combined with prior knowledge about the measurement devices, this approach can be used to obtain a robust predictive model. A stochastic-...

  19. Analog and VLSI circuits

    CERN Document Server

    Chen, Wai-Kai

    2009-01-01

    Featuring hundreds of illustrations and references, this book provides the information on analog and VLSI circuits. It focuses on analog integrated circuits, presenting the knowledge on monolithic device models, analog circuit cells, high performance analog circuits, RF communication circuits, and PLL circuits.

  20. A new principle for measurement of cobalamin and corrinoids, used for studies of cobalamin analogs on serum haptocorrin

    DEFF Research Database (Denmark)

    Hardlei, Tore Forsingdal; Nexø, Ebba

    2009-01-01

    BACKGROUND: Transcobalamin (TC) and haptocorrin (HC) are serum corrinoid-binding proteins. We developed new methods for measurement of the corrinoids bound to HC and TC. METHODS: TC (n = 10) or HC (n = 138) was immunoprecipitated, and corrinoids were released by enzymatic degradation [subtilisin Carlsberg (EC 3.4.21.62)] of the binding proteins. Binding of the released corrinoids to added unsaturated TC (apoTC) or HC (apoHC) created holoTC (as measure of cobalamins) and holoHC (as measure of cor...

  1. Assessment of skeletal muscle blood flow and glucose metabolism with positron emitting radionuclides

    International Nuclear Information System (INIS)

    The potassium analog, Rb-82 was used to measure skeletal muscle blood flow and the glucose analog, 18-F-2-deoxy-2-fluoro-D-glucose (FDG) was used to examine the kinetics of skeletal muscle transport and phosphorylation. New Zealand white rabbits' blood flow ranged from 1.0-70 ml/min/100g with the lowest flows occurring under baseline conditions and the highest flows were measured immediately after exercise. Elevated plasma glucose had no effect on increasing blood flow, whereas high physiologic to pharmacologic levels of insulin doubled flow as measured by the radiolabeled microspheres, but a proportionate increase was not detected by Rb-82. The data suggest that skeletal muscle blood flow can be measured using the positron emitting K+ analog Rb-82 under low flow and high flow conditions but not when insulin levels in the plasma are elevated. This may be due to the fact that insulin induces an increase in the Na+/K+-ATPase activity of the cell indirectly through a direct increase in the Na+/H+pump activity

  2. Noninvasive measurement of blood flow, oxygen consumption, and glucose utilization in the same brain regions in man by positron emission tomography: concise communication

    International Nuclear Information System (INIS)

    Local cerebral blood flow (CBF), oxygen consumption (CMRO2), and glucose utilization (CMR-Glc) have been measured in three patients by positron emission tomography (PET), together with continuous inhalation of 15O labeled gases and i.v. injection of [18F]fluoro-2-deoxy-D-glucose. In normal brain, the close local coupling between CBF and CMR-Glc, and that between CMRO2 and CMR-Glc, were well demonstrated. The coupling held for the asymptomatic areas and for parts of the affected hemispheres in two patients with cerebral ischemia. In one patient the CBF/CMR-Glc couple, but not the CMRO2/CMR-Glc couple, was disrupted in the acute ischemic core. This preliminary work demonstrates the local quantification of these important functional parameters, and indicates the potential usefulness of studying their pathophysiological interrelationship in brain disease

  3. Spectral Reflectance Measurements of Sulfides at the Planetary Emissivity Laboratory — Analogs for Hollow-Forming Material on Mercury?

    OpenAIRE

    Helbert, Joern; Maturilli, Alessandro; D'Amore, Mario; Vaughan, W.M.; Head, J.W.; Klima, R.L.; Blewett, D.T.; McCoy, T.

    2012-01-01

    We present spectral reflectance measurements at visible and near-infrared wavelengths of fresh and heated samples of MnS, CaS, and MgS, as well as elemental sulfur. We infer that sulfides display a diagnostic feature at or near 0.6 µm.

  4. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

  5. Estimating Plasma Glucose from Interstitial Glucose: The Issue of Calibration Algorithms in Commercial Continuous Glucose Monitoring Devices

    OpenAIRE

    Paolo Rossetti; Josep Vehí; Jorge Bondia; Fanelli, Carmine G.

    2010-01-01

    Evaluation of metabolic control of diabetic people has been classically performed measuring glucose concentrations in blood samples. Due to the potential improvement it offers in diabetes care, continuous glucose monitoring (CGM) in the subcutaneous tissue is gaining popularity among both patients and physicians. However, devices for CGM measure glucose concentration in compartments other than blood, usually the interstitial space. This means that CGM need calibration against blood glucose va...

  6. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  7. Edentulism and dental prostheses in the elderly: impact on quality of life measured with EuroQol - visual analog scale (EQ-VAS).

    Science.gov (United States)

    Cano-Gutiérrez, Carlos; Borda, Miguel G; Arciniegas, Antonio J; Borda, Claudia X

    2015-08-01

    The objective of this study was to measure the impact of edentulism and dental prostheses on quality of life (QOL) in older adults in Bogota, Colombia. Edentulism is a frequent condition in older adults and has great impact on their QOL. No epidemiological data are currently available on edentulism among older adults in Colombia. Data were obtained from the SABE-Bogota study, a cross-sectional study conducted in 2012, and used to analyze the EQ-VAS (Visual Analog Scale) from the EuroQol instrument to measure the perception of quality of life (QOL) in relation to edentulism. The study included 2,000 individuals over 60 years old. The Spearman-Rho correlation was used to analyze the correlation between EQ-VAS and edentulism. Chi-Square, ANOVA and t-test were used to study the differences in EQ-VAS scores between edentulous and healthy subjects. Statistical significance was set at peducation were related to edentulism. Individuals with fewer teeth and dental prostheses had lower EQ-VAS scores (p<0.05) and dental prosthesis did not improve EQ-VAS scores (p=0.22). Edentulism also showed a significant negative correlation with EQ-VAS scores (rho= -0.102, p<0.01). In summary, EQ-VAS is a useful tool for measuring the perception of QOL in dental health scenarios. Edentulism significantly affects QOL in older adults and the use of dental prosthesis does not improve the perception of QOL. PMID:26355885

  8. Optical imaging of tumor vascularity associated with proliferation and glucose metabolism in early breast cancer: clinical application of total hemoglobin measurements in the breast

    International Nuclear Information System (INIS)

    Near-infrared optical imaging targeting the intrinsic contrast of tissue hemoglobin has emerged as a promising approach for visualization of vascularity in cancer research. We evaluated the usefulness of diffuse optical spectroscopy using time-resolved spectroscopic (TRS) measurements for functional imaging of primary breast cancer. Fifty-five consecutive TNM stageI/II patients with histologically proven invasive ductal carcinoma and operable breast tumors (<5 cm) who underwent TRS measurements were enrolled. Thirty (54.5%) patients underwent 18F-fluoro-deoxy-glucose (FDG) positron emission tomography with measurement of maximum tumor uptake. TRS was used to obtain oxyhemoglobin, deoxyhemoglobin, and total hemoglobin (tHb) levels from the lesions, surrounding normal tissue, and contralateral normal tissue. Lesions with tHb levels 20% higher than those present in normal tissue were defined as “hotspots,” while others were considered “uniform.” The findings in either tumor type were compared with clinicopathological factors. “Hotspot” tumors were significantly larger (P = 0.002) and exhibited significantly more advanced TNM stage (P = 0.01), higher mitotic counts (P = 0.01) and higher levels of FDG uptake (P = 0.0004) compared with “uniform” tumors; however, other pathological variables were not significantly different between the two groups. Optical imaging for determination of tHb levels allowed for measurement of tumor vascularity as a function of proliferation and glucose metabolism, which may be useful for prediction of patient prognosis and potential response to treatment

  9. Sketching, analogies and creativity

    OpenAIRE

    Verstijnen, Ilse Marieke; Heylighen, Ann; Wagemans, Johan; Neuckermans, Herman

    2001-01-01

    Paper and pencil sketching, visual analogies, and creativity are intuitively interconnected in design. This paper reports on previous and current research activities of a psychologist (the 1st author) and an architect/designer (the 2nd author) on issues concerning sketching and analogies, and analogies and creativity respectively. In this paper we tried to unite these findings into a combined theory on how sketching, analogies, and creativity interrelate. An appealing theory emerges. It...

  10. Analog Frequency Tracking Filter

    OpenAIRE

    ISAR, A.; ISAR, D.

    2013-01-01

    This paper propose a new type of analog adaptive filter derived as a generalization of the concept of matched filter. We conceive such a filter to track the instantaneous frequency of frequency modulated signals. Some properties of the proposed analog frequency tracking filter are established using the time-frequency representations theory. A constructive solution, based on common analog integrated circuits, is also proposed. The performance of the analog frequency tracking filter built ...

  11. Radioactive Decay - An Analog.

    Science.gov (United States)

    McGeachy, Frank

    1988-01-01

    Presents an analog of radioactive decay that allows the student to grasp the concept of half life and the exponential nature of the decay process. The analog is devised to use small, colored, plastic poker chips or counters. Provides the typical data and a graph which supports the analog. (YP)

  12. Analog and hybrid computing

    CERN Document Server

    Hyndman, D E

    2013-01-01

    Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl

  13. High-speed analog commutator

    Energy Technology Data Exchange (ETDEWEB)

    Bessonova, N.A.; Meleshko, E.A.; Oleinik, S.V.; Palkin, Yu.Yu.

    1988-07-01

    A 16-channel high-speed commutator of analog signals is described that is implemented by KR590KT1 integrated-circuit switches. The commutator is designed for multichannel measuring systems for recording sampled instantaneous values of input signals. The maximum channel-switching frequency is approximately 20 MHz and the integral nonlinearity of the transmission coefficient is 0.2%.

  14. A Tale of Two Compartments: Interstitial Versus Blood Glucose Monitoring

    OpenAIRE

    Cengiz, Eda; Tamborlane, William V.

    2009-01-01

    Self-monitoring of blood glucose was described as one of the most important advancements in diabetes management since the invention of insulin in 1920. Recent advances in glucose sensor technology for measuring interstitial glucose concentrations have challenged the dominance of glucose meters in diabetes management, while raising questions about the relationships between interstitial and blood glucose levels. This article will review the differences between interstitial and blood glucose and...

  15. Analog fiber optic transmission link

    International Nuclear Information System (INIS)

    An analog fiber optic transmission link (FOTL) has been designed for relaying signals from equipment held at high voltage potentials to equipment at ground potential. The need for a fiber link arises from the requirements of low energy, light ion experiments conducted at the Triangle Universities Nuclear Laboratory. In these experiments, ions are accelerated and transported to a high voltage scattering chamber and the FOTL is used to transmit signals from the scattering chamber to remote data acquisition systems. The performance of the link is mainly driven by the stringent requirements needed for successful transmission of analog pulses from radiation detectors located in the scattering chamber. The FOTL consists of a transmitter, receiver, and baseline restorer that are capable of transmitting radiation detector pulses without pulse height distortion, thus allowing high resolution energy measurements. The FOTL is also suitable for use with a wide variety of other analog signal types

  16. Simultaneous integration of biosensor and EEG measurements in freely moving rodents: Dynamic changes of brain glucose and glutamate concentrations during transitions between different sleep states in the mouse pre-frontal cortex

    Directory of Open Access Journals (Sweden)

    David A Johnson

    2009-06-01

    Full Text Available This work demonstrates a direct correlation between glutamate and glucose levels in the pre-frontal cortex of mice and sleep state. Male C57 mice were simultaneously implanted with an intracerebral guide cannula targeting the prefrontal cortex and electrodes to measure cortical electroencephalographs (EEG. A turn-key Pinnacle 8401 EEG/EMG/Biosensor system was used to record real-time, second by second measurements of glucose or glutamate levels and EEG activity over a 24 hour period. Results showed that glucose levels in mice transitioning from waking to slow-wave sleep rose an average of 116 +/- 27 uM (n=57 episodes. Conversely, glucose levels in mice transitioning from sleep to wakefulness resulted in an average decrease of 121 +/- 27uM glucose. (n=54 episodes. Glutamate levels rose an average of 0.52 +/- 0.21uM upon during REM episodes lasting longer than one minute before returning to baseline levels following the REM episode. Second by second measurement of neurochemicals such as glutamate, glucose and lactate in the brain using electrochemical biosensors is a powerful tool that can be used to profile concentration changes due to pharmacological and behavioral interactions. Funding through NIH SBIR Grant #5T44MH076318-03

  17. Evaluation of the relationship between capillary and venous plasma glucose concentrations obtained by the HemoCue Glucose 201+ system during an oral glucose tolerance test

    OpenAIRE

    Ignell, Claes; Berntorp, Kerstin

    2011-01-01

    Abstract In 55 women with previous gestational diabetes mellitus, simultaneous capillary and venous plasma glucose concentrations were measured at 0, 30 and 120 min during a 75 g oral glucose tolerance test (OGTT). The aims of the study were to examine the relationship between capillary and venous glucose measurements, and to establish equations for the conversion of capillary and venous glucose concentrations using the HemoCue Glucose 201+ system. Additionally, the correlation between the ca...

  18. Classical analog of entanglement

    International Nuclear Information System (INIS)

    We show that quantum entanglement has a very close classical analog, namely, secret classical correlations. The fundamental analogy stems from the behavior of quantum entanglement under local operations and classical communication and the behavior of secret correlations under local operations and public communication. A large number of derived analogies follow. In particular, teleportation is analogous to the one time pad, the concept of 'pure state' exists in the classical domain, entanglement concentration and dilution are essentially classical secrecy protocols, and single-copy-entanglement manipulations have such a close classical analog that the majorization results are reproduced in the classical setting. This analogy allows one to import questions from the quantum domain into the classical one, and vice versa, helping to get a better understanding of both. Also, by identifying classical aspects of quantum entanglement, it allows one to identify those aspects of entanglement that are uniquely quantum mechanical

  19. Microwave-Based Biosensor for Glucose Detection

    Science.gov (United States)

    Salim, N. S. M.; Khalid, K.; Yusof, N. A.

    2010-07-01

    In this project, microwave-based biosensor for glucose detection has been studied. The study is based on the dielectric properties changes at microwave frequency for glucose-enzyme reaction. Glucose interaction with glucose oxidase (GOD) produced gluconic acid and hydrogen peroxide. The reaction of the glucose solutions with an enzyme was carried out in 1:3 of glucose and enzyme respectively. The measurements were done using the Open Ended Coaxial Probe (OECP) coupled with computer controlled software automated network analyzer (ANA) with frequency range from 200MHz to 20GHz at room temperature (25 °C). The differences of enzyme and glucose-enzyme reaction were calculated and plotted. In the microwave interaction with the glucose-enzyme reaction, ionic conduction and dipole molecules was detected at 0.99GHz and 16.44GHz respectively based on changes of dielectric loss factor.

  20. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  1. Analogies in theoretical physics

    OpenAIRE

    Jona-Lasinio, Giovanni

    2010-01-01

    Analogies have had and continue to have an important role in the development of theoretical physics. They may start from similarities of physical concepts followed by similarities in the mathematical formalization or it may be a purely mathematical aspect to suggest the development of analogous physical concepts. More often a subtle non obvious interplay between these levels is involved. In this paper I will discuss two cases sufficiently intricate to illustrate some ways of how analogies wor...

  2. Nonradioisotope assay of glucose uptake activity in rat skeletal muscle using enzymatic measurement of 2-deoxyglucose 6-phosphate in vitro and in vivo.

    Science.gov (United States)

    Ueyama, A; Sato, T; Yoshida, H; Magata, K; Koga, N

    2000-01-01

    We investigated a nonradioisotope method for the evaluation of glucose uptake activity using enzymatic measurement of 2-deoxyglucose 6-phosphate (2DG6P) content in isolated rat soleus muscle in vitro and in vivo. The 2DG6P content in isolated rat soleus muscle after incubation with 2-deoxyglucose (2DG) was increased in a dose-dependent manner by insulin (ED(50) = 0.6 mU/ml), the maximum response being about 5 times that of the basal content in vitro. This increment was completely abolished by wortmannin (100 nM), with no effect on basal 2DG6P content. An insulin-mimetic compound, vanadium, also increased 2DG6P content in a dose-dependent manner. In isolated soleus muscle of Zucker fa/fa rats, well known as an insulin-resistant model, insulin did not increase 2DG6P content. The 2DG6P content in rat soleus muscle increased after 2DG (3 mmol/kg) injection in vivo, and conversely, the 2DG concentration in plasma was decreased in a dose-dependent manner by insulin (ED(50) = 0.11 U/kg). The maximum response of the accumulation of 2DG6P in soleus muscle was about 4 times that of the basal content. This method could be useful for evaluating glucose uptake (transport plus phosphorylation) activity in soleus muscle in vitro and in vivo without using radioactive materials. PMID:10965062

  3. Laboratory measurements of P-wave and S-wave velocities across a surface analog of the continental crust-mantle boundary: Cabo Ortegal, Spain

    Science.gov (United States)

    Brown, Dennis; Llana-Funez, Sergio; Carbonell, Ramon; Alvarez-Marron, Joaquina; Marti, David; Salisbury, Matt

    2010-05-01

    The Paleozoic Cabo Ortegal Complex of NW Spain provides an exposed analog of the continental crust-mantle transition. It is composed of an overturned section that, at its base, begins with felsic gneisses, followed upward by eclogites, intermediate and mafic granulties, and ultramafic rocks. Peak metamorphic conditions reached c. 800°C and 1.7 GPa in the Middle to Late Devonian. Fourteen samples were analysed for P-wave and S-wave velocities, as well as density at the High Pressure Lab at Dalhousie University, Canada. Seismic velocities were measured at pressures of 10 to 600 MPa at a temperature of 20°C. When possible, measurements were made parallel and perpendicular to banding and parallel to the lineation. The major element composition of each sample was measured by XRF at the University of Barcelona, Spain. Samples display a broad range of P-wave and S-wave velocities (6.2 to 8.2 km/s and 3.2 to 4.6 km/s at 600 MPa, respectively) that generally increase with density (2.7 to 3.4 g/cm3) and reflect an overall increase from middle to lower crustal velocities in the felsic gneisses and intermediate to mafic granulites to mantle velocities in the eclogites and ultramafic rocks. The seismic Moho (P-wave velocity > 7.6 km/s) is reached at the mappable contact between the gneisses and the eclogite, whereas the compositional Moho, or crust-mantle transition occurs at the transitional contact between the mafic granulites and peridotites. Between 200 and 600 MPa, P-wave anisotropy ranges from between 2% and 8%, whereas S-wave anisotropy ranges from <1% to around 8%, according to rock type. Poisson's ratios calculated from the laboratory measurements are within the range of those determined from field experiments elsewhere. P-wave reflection coefficients between the various lithologies range from 0.21 to 0.08. These laboratory data provide a calibration for the physical properties and the nature of reflectivity of the in-situ lower continental crust and upper mantle transition.

  4. Evaluation and clinically relevant applications of a fluorescent imaging analog to fluorodeoxyglucose positron emission tomography

    Science.gov (United States)

    Sheth, Rahul A.; Josephson, Lee; Mahmood, Umar

    2009-11-01

    A fluorescent analog to 2-deoxy-2 [18F] fluoro-D-glucose position emission tomography (FDG-PET) would allow for the introduction of metabolic imaging into intraoperative and minimally invasive settings. We present through in vitro and in vivo experimentation an evaluation of 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG), a fluorescently labeled glucose molecule, as a molecular beacon of glucose utilization. The competitive inhibition of 2-NBDG uptake by excess free glucose is directly compared against FDG uptake inhibition in cultured cells. 2-NBDG uptake in the brain of a mouse experiencing a generalized seizure is measured, as well as in subcutaneously implanted tumors in mice during fed and fasting states. Localization of 2-NBDG into malignant tissues is studied by laser scanning microscopy. The clinical relevance of 2-NBDG imaging is examined by performing fluorescence colonoscopy, and by correlating preoperative FDG-PET with intraoperative fluorescence imaging. 2-NBDG exhibits a similar uptake inhibition to FDG by excess glucose in the growth media. Uptake is significantly increased in the brain of an animal experiencing seizures versus control, and in subcutaneous tumors after the animals are kept nil per os (NPO) for 24 h versus ad libidum feeding. The clinical utility of 2-NBDG is confirmed by the demonstration of very high target-to-background ratios in minimally invasive and intraoperative imaging of malignant lesions. We present an optical analog of FDG-PET to extend the applicability of metabolic imaging to minimally invasive and intraoperative settings.

  5. Glucose and fructose 6-phosphate cycle in humans

    International Nuclear Information System (INIS)

    We have determined the rate of glucose cycling by comparing turnovers of [2-3H]- and [6-3H]glucose under basal conditions and during a glucose infusion. Moreover, the activity of the fructose 6-phosphate cycle was assessed by comparing [3-3H]- and [6-3H]glucose. The study included eight lean subjects with normal glucose tolerance. They participated in two randomly performed investigations. In one experiment [2-3H]- and [6-3H]glucose were given simultaneously, while in the other only [3-3H]glucose was given. The basal rate of glucose cycling was 0.32 +/- 0.08 mg X kg-1 X min-1 or 17% of basal glucose production (P less than 0.005). During glucose infusion the activity of endogenous glucose cycling did not change but since glucose production was suppressed it amounted to 130% of glucose production. The basal fructose 6-phosphate cycle could be detected only in three subjects and was suppressed during glucose infusion. In conclusion, the glucose cycle is active in healthy humans both in basal conditions and during moderate hyperglycemia. In some subjects, the fructose 6-phosphate cycle also appears to be active. Thus it is preferable to use [6-3H]glucose rather than [3-3H]glucose when measuring glucose production and particularly when assessing glucose cycle

  6. Blood Glucose Log

    Science.gov (United States)

    ... cut here ¢ cut here ¢ If you have high blood glucose , make notes in your log and talk with ... plan, physical activity, or diabetes medicines. Having low blood glucose means that your blood glucose level is too ...

  7. The determination of solubility and diffusion coefficient for solids in liquids by an inverse measurement technique using cylinders of amorphous glucose as a model compound

    Science.gov (United States)

    Hu, Chengyao; Huang, Pei

    2011-05-01

    The importance of sugar and sugar-containing materials is well recognized nowadays, owing to their application in industrial processes, particularly in the food, pharmaceutical and cosmetic industries. Because of the large numbers of those compounds involved and the relatively small number of solubility and/or diffusion coefficient data for each compound available, it is highly desirable to measure the solubility and/or diffusion coefficient as efficiently as possible and to be able to improve the accuracy of the methods used. In this work, a new technique was developed for the measurement of the diffusion coefficient of a stationary solid solute in a stagnant solvent which simultaneously measures solubility based on an inverse measurement problem algorithm with the real-time dissolved amount profile as a function of time. This study differs from established techniques in both the experimental method and the data analysis. The experimental method was developed in which the dissolved amount of solid solute in quiescent solvent was investigated using a continuous weighing technique. In the data analysis, the hybrid genetic algorithm is used to minimize an objective function containing a calculated and a measured dissolved amount with time. This is measured on a cylindrical sample of amorphous glucose in methanol or ethanol. The calculated dissolved amount, that is a function of the unknown physical properties of the solid solute in the solvent, is calculated by the solution of the two-dimensional nonlinear inverse natural convection problem. The estimated values of the solubility of amorphous glucose in methanol and ethanol at 293 K were respectively 32.1 g/100 g methanol and 1.48 g/100 g ethanol, in agreement with the literature values, and support the validity of the simultaneously measured diffusion coefficient. These results show the efficiency and the stability of the developed technique to simultaneously estimate the solubility and diffusion coefficient. Also the influence of the solution density change and the initial concentration conditions on the dissolved amount was investigated by the numerical results using the estimated parameters. It is found that the theoretical assumption to simplify the inverse measurement problem algorithm is reasonable for low solubility.

  8. The determination of solubility and diffusion coefficient for solids in liquids by an inverse measurement technique using cylinders of amorphous glucose as a model compound

    International Nuclear Information System (INIS)

    The importance of sugar and sugar-containing materials is well recognized nowadays, owing to their application in industrial processes, particularly in the food, pharmaceutical and cosmetic industries. Because of the large numbers of those compounds involved and the relatively small number of solubility and/or diffusion coefficient data for each compound available, it is highly desirable to measure the solubility and/or diffusion coefficient as efficiently as possible and to be able to improve the accuracy of the methods used. In this work, a new technique was developed for the measurement of the diffusion coefficient of a stationary solid solute in a stagnant solvent which simultaneously measures solubility based on an inverse measurement problem algorithm with the real-time dissolved amount profile as a function of time. This study differs from established techniques in both the experimental method and the data analysis. The experimental method was developed in which the dissolved amount of solid solute in quiescent solvent was investigated using a continuous weighing technique. In the data analysis, the hybrid genetic algorithm is used to minimize an objective function containing a calculated and a measured dissolved amount with time. This is measured on a cylindrical sample of amorphous glucose in methanol or ethanol. The calculated dissolved amount, that is a function of the unknown physical properties of the solid solute in the solvent, is calculated by the solution of the two-dimensional nonlinear inverse natural convection problem. The estimated values of the solubility of amorphous glucose in methanol and ethanol at 293 K were respectively 32.1 g/100 g methanol and 1.48 g/100 g ethanol, in agreement with the literature values, and support the validity of the simultaneously measured diffusion coefficient. These results show the efficiency and the stability of the developed technique to simultaneously estimate the solubility and diffusion coefficient. Also the influence of the solution density change and the initial concentration conditions on the dissolved amount was investigated by the numerical results using the estimated parameters. It is found that the theoretical assumption to simplify the inverse measurement problem algorithm is reasonable for low solubility

  9. Aqueous glucose measurement using differential absorption-based frequency domain optical coherence tomography at wavelengths of 1310 nm and 1625 nm

    Science.gov (United States)

    John, Pauline; Manoj, Murali; Sujatha, N.; Vasa, Nilesh J.; Rao, Suresh R.

    2015-07-01

    This work presents a combination of differential absorption technique and frequency domain optical coherence tomography for detection of glucose, which is an important analyte in medical diagnosis of diabetes. Differential absorption technique is used to detect glucose selectively in the presence of interfering species especially water and frequency domain optical coherence tomography (FDOCT) helps to obtain faster acquisition of depth information. Two broadband super-luminescent diode (SLED) sources with centre wavelengths 1586 nm (wavelength range of 1540 to 1640 nm) and 1312 nm (wavelength range of 1240 to 1380 nm) and a spectral width of ? 60 nm (FWHM) are used. Preliminary studies on absorption spectroscopy using various concentrations of aqueous glucose solution gave promising results to distinguish the absorption characteristics of glucose at two wavelengths 1310 nm (outside the absorption band of glucose) and 1625 nm (within the absorption band of glucose). In order to mimic the optical properties of biological skin tissue, 2% and 10% of 20% intralipid with various concentrations of glucose (0 to 4000 mg/dL) was prepared and used as sample. Using OCT technique, interference spectra were obtained using an optical spectrum analyzer with a resolution of 0.5 nm. Further processing of the interference spectra provided information on reflections from the surfaces of the cuvette containing the aqueous glucose sample. Due to the absorption of glucose in the wavelength range of 1540 nm to 1640 nm, a trend of reduction in the intensity of the back reflected light was observed with increase in the concentration of glucose.

  10. Hydraulic Capacitor Analogy

    Science.gov (United States)

    Baser, Mustafa

    2007-01-01

    Students have difficulties in physics because of the abstract nature of concepts and principles. One of the effective methods for overcoming students' difficulties is the use of analogies to visualize abstract concepts to promote conceptual understanding. According to Iding, analogies are consistent with the tenets of constructivist learning…

  11. Hydraulic Capacitor Analogy

    Science.gov (United States)

    Baser, Mustafa

    2007-01-01

    Students have difficulties in physics because of the abstract nature of concepts and principles. One of the effective methods for overcoming students' difficulties is the use of analogies to visualize abstract concepts to promote conceptual understanding. According to Iding, analogies are consistent with the tenets of constructivist learning…

  12. Assessing liver function by magnetic resonance imaging two-dimensional phase-shift flow measurement of portal venous blood flow after oral intake of glucose

    International Nuclear Information System (INIS)

    We have already reported that the ratio of portal venous flow 30 min after oral intake of glucose 75 g to that before intake (PVFR30), measured using pulsed-Doppler ultrasonography (US), correlated significantly with other indicators of liver function and that it could be used to estimate hepatic function before surgery, including liver resection. In this study, to assess the disadvantages of pulsed-Doppler ultrasonography, PVFR30 was measured using two-dimensional (2D) phase-shift (PS) magnetic resonance imaging (MRI). PVFR30 was measured in 17 patients and 7 volunteers: 13 with liver cirrhosis (LC) and 11 without LC (non-LC). Portal venous flow could be measured in all patients without any disturbance of intestinal gas or patient fat, or the high degree of technical skill that Doppler US requires. PVFR30 was significantly lower in the LC group than in the non-LC group. In addition, it correlated significantly with other indicators of liver function, including the indocyanine green clearance test, prothrombin time, hepaplastin test, and cholinesterase activity. These results suggest that PVFR30 measured by 2D PS MRI can be used to estimate liver function, and that this MRI method can be performed more easily than pulsed-Doppler US. (author)

  13. Analysis of Continuous Glucose Monitoring in Pregnant Women With Diabetes

    DEFF Research Database (Denmark)

    Law, Graham R; Ellison, George T H; Secher, Anna L; Damm, Peter; Mathiesen, Elisabeth R; Temple, Rosemary; Murphy, Helen R; Scott, Eleanor M

    2015-01-01

    OBJECTIVE: Continuous glucose monitoring (CGM) is increasingly used to assess glucose control in diabetes. The objective was to examine how analysis of glucose data might improve our understanding of the role temporal glucose variation has on large-for-gestational-age (LGA) infants born to women with diabetes. RESEARCH DESIGN AND METHODS: Functional data analysis (FDA) was applied to 1.68 million glucose measurements from 759 measurement episodes, obtained from two previously published randomize...

  14. Blood-brain glucose transfer in spreading depression

    DEFF Research Database (Denmark)

    Gjedde, A; Hansen, A J; Quistorff, B

    1981-01-01

    Spreading depression in rat brain cortex is associated with a twofold increase of cerebral blood flow. It is not known whether this increase is coupled to increases of cerebral metabolic rate and glucose transport from blood to brain. During the passage of a single spreading depression, we measured blood-brain glucose transport and glucose metabolism in rat cerebral cortex by single intravenous injection of tracer glucose. Blood flow and tissue content of glucose were measure as well. Reduction ...

  15. Genetic variation in GIPR influences the glucose and insulin responses to an oral glucose challenge

    DEFF Research Database (Denmark)

    Saxena, Richa; Hivert, Marie-France; Langenberg, Claudia; Tanaka, Toshiko; Pankow, James S; Vollenweider, Peter; Lyssenko, Valeriya; Bouatia-Naji, Nabila; Dupuis, Josée; Jackson, Anne U; Kao, W H Linda; Li, Man; Glazer, Nicole L; Manning, Alisa K; Luan, Jian'an; Stringham, Heather M; Prokopenko, Inga; Johnson, Toby; Grarup, Niels; Boesgaard, Trine W; Lecoeur, Cécile; Shrader, Peter; O'Connell, Jeffrey; Ingelsson, Erik; Couper, David J; Rice, Kenneth; Song, Kijoung; Andreasen, Camilla H; Dina, Christian; Köttgen, Anna; Le Bacquer, Olivier; Pattou, François; Taneera, Jalal; Steinthorsdottir, Valgerdur; Rybin, Denis; Ardlie, Kristin; Sampson, Michael; Qi, Lu; van Hoek, Mandy; Weedon, Michael N; Aulchenko, Yurii S; Voight, Benjamin F; Grallert, Harald; Balkau, Beverley; Bergman, Richard N; Bielinski, Suzette J; Bonnefond, Amelie; Bonnycastle, Lori L; Borch-Johnsen, Knut; Böttcher, Yvonne; Brunner, Eric; Buchanan, Thomas A; Bumpstead, Suzannah J; Cavalcanti-Proença, Christine; Charpentier, Guillaume; Chen, Yii-Der Ida; Chines, Peter S; Collins, Francis S; Cornelis, Marilyn; J Crawford, Gabriel; Delplanque, Jerome; Doney, Alex; Egan, Josephine M; Erdos, Michael R; Firmann, Mathieu; Forouhi, Nita G; Fox, Caroline S; Goodarzi, Mark O; Graessler, Jürgen; Hingorani, Aroon; Isomaa, Bo; Jørgensen, Torben; Kivimaki, Mika; Kovacs, Peter; Krohn, Knut; Kumari, Meena; Lauritzen, Torsten; Lévy-Marchal, Claire; Mayor, Vladimir; McAteer, Jarred B; Meyre, David; Mitchell, Braxton D; Mohlke, Karen L; Morken, Mario A; Narisu, Narisu; Palmer, Colin N A; Pakyz, Ruth; Pascoe, Laura; Payne, Felicity; Pearson, Daniel; Rathmann, Wolfgang; Sandbaek, Annelli; Sayer, Avan Aihie; Scott, Laura J; Sharp, Stephen J; Sijbrands, Eric; Singleton, Andrew; Siscovick, David S; Smith, Nicholas L; Sparsø, Thomas; Swift, Amy J; Syddall, Holly; Thorleifsson, Gudmar; Tönjes, Anke; Tuomi, Tiinamaija; Tuomilehto, Jaakko; Valle, Timo T; Waeber, Gérard; Walley, Andrew; Waterworth, Dawn M; Zeggini, Eleftheria; Zhao, Jing Hua; Illig, Thomas; Wichmann, H Erich; Wilson, James F; van Duijn, Cornelia; Hu, Frank B; Morris, Andrew D; Frayling, Timothy M; Hattersley, Andrew T; Thorsteinsdottir, Unnur; Stefansson, Kari; Nilsson, Peter; Syvänen, Ann-Christine; Shuldiner, Alan R; Walker, Mark; Bornstein, Stefan R; Schwarz, Peter; Williams, Gordon H; Nathan, David M; Kuusisto, Johanna; Laakso, Markku; Cooper, Cyrus; Marmot, Michael; Ferrucci, Luigi; Mooser, Vincent; Stumvoll, Michael; Loos, Ruth J F; Altshuler, David; Psaty, Bruce M; Rotter, Jerome I; Boerwinkle, Eric; Hansen, Torben; Pedersen, Oluf; Florez, Jose C; McCarthy, Mark I; Boehnke, Michael; Barroso, Inês; Sladek, Robert; Froguel, Philippe; Meigs, James B; Groop, Leif; Wareham, Nicholas J; Watanabe, Richard M

    2010-01-01

    Glucose levels 2 h after an oral glucose challenge are a clinical measure of glucose tolerance used in the diagnosis of type 2 diabetes. We report a meta-analysis of nine genome-wide association studies (n = 15,234 nondiabetic individuals) and a follow-up of 29 independent loci (n = 6,958-30,620)...

  16. Hyperglycemia-induced stimulation of glucose transport in skeletal muscle measured by PET-[18F]6FDG and [18F]2FDG

    OpenAIRE

    Huang, Hsuan-Ming; Chandramouli, Visvanathan; Ismail-Beigi, Faramarz; Raymond F. Muzic

    2012-01-01

    A physiologically based model proposed by our group has been developed to assess glucose transport and phosphorylation in skeletal muscle. In this study, we investigated whether our model has the ability to detect a glucose-induced increase in glucose transport in skeletal muscle. In particular, we used small-animal positron emission tomography (PET) data obtained from [18F]6-fluoro-6-deoxy-D-glucose ([18F]6FDG). A two-hour PET scan was acquired following a bolus injection of [18F]6FDG in rat...

  17. Impact of Glucose Tolerance Status, Sex, and Body Size on Glucose Absorption Patterns During OGTTs

    DEFF Research Database (Denmark)

    Faerch, K.; Pacini, G.; Nolan, J. J.; Hansen, Torben; Tura, A.; Vistisen, D.

    2013-01-01

    OBJECTIVEWe studied whether patterns of glucose absorption during oral glucose tolerance tests (OGTTs) were abnormal in individuals with impaired glucose regulation and whether they were related to sex and body size (height and fat-free mass). We also examined how well differences in insulin sensitivity and -cell function measured by gold-standard tests were reflected in the corresponding OGTT-derived estimates.RESEARCH DESIGN AND METHODSWith validated methods, various aspects of glucose absorpt...

  18. Meat analog: a review.

    Science.gov (United States)

    Malav, O P; Talukder, S; Gokulakrishnan, P; Chand, S

    2015-01-01

    The health-conscious consumers are in search of nutritious and convenient food item which can be best suited in their busy life. The vegetarianism is the key for the search of such food which resembles the meat in respect of nutrition and sensory characters, but not of animal origin and contains vegetable or its modified form, this is the point when meat analog evolved out and gets shape. The consumers gets full satisfaction by consumption of meat analog due to its typical meaty texture, appearance and the flavor which are being imparted during the skilled production of meat analog. The supplement of protein in vegetarian diet through meat alike food can be fulfilled by incorporating protein-rich vegetative food grade materials in meat analog and by adopting proper technological process which can promote the proper fabrication of meat analog with acceptable meat like texture, appearance, flavor, etc. The easily available vegetables, cereals, and pulses in India have great advantages and prospects to be used in food products and it can improve the nutritional and functional characters of the food items. The various form and functional characters of food items are available world over and attracts the meat technologists and the food processors to bring some innovativeness in meat analog and its presentation and marketability so that the acceptability of meat analog can be overgrown by the consumers. PMID:24915320

  19. Discrete LIBOR Market Model Analogy

    CERN Document Server

    Hula, Andreas

    2011-01-01

    This paper provides a discrete time LIBOR analog, which can be used for arbitrage-free discretization of Levy LIBOR models or discrete approximation of continuous time LIBOR market models. Using the work of Eberlein and Oezkan as an inspiration, we build a discrete forward LIBOR market model by starting with a discrete exponential martingale. We take this pure jump process and calculate the appropriate measure change between the forward measures. Next we prove weak convergence of the discrete analog to the continuous time LIBOR model, provided the driving process converges weakly to the continuous time one and the driving processes are PII's. This especially implies the weak convergence of the model to a Levy LIBOR market model if the driving process variables are infinitely divisible distributions. This also relates our model to an Euler discretization.

  20. Impact of Glucose Tolerance Status, Sex, and Body Size on Glucose Absorption Patterns During OGTTs

    DEFF Research Database (Denmark)

    Faerch, K.; Pacini, G.

    2013-01-01

    OBJECTIVEWe studied whether patterns of glucose absorption during oral glucose tolerance tests (OGTTs) were abnormal in individuals with impaired glucose regulation and whether they were related to sex and body size (height and fat-free mass). We also examined how well differences in insulin sensitivity and -cell function measured by gold-standard tests were reflected in the corresponding OGTT-derived estimates.RESEARCH DESIGN AND METHODSWith validated methods, various aspects of glucose absorption were estimated from 12-point, 3-h, 75-g OGTTs in 66 individuals with normal glucose tolerance (NGT), isolated impaired fasting glucose (i-IFG), or isolated impaired glucose tolerance (i-IGT). Insulin sensitivity and -cell function were measured with the euglycemic-hyperinsulinemic clamp and intravenous glucose tolerance tests, respectively. Surrogate markers of both conditions were calculated from OGTTs.RESULTSMore rapid glucose absorption (P 0.036) and reduced late glucose absorption (P 0.039) were observed in thei-IFG group relative to NGT and i-IGT groups. Women with i-IGT had a lower early glucose absorption than did men with i-IGT (P = 0.041); however, this difference did not persist when differences in body size were taken into account (P > 0.28). Faster glucose absorption was related to higher fasting (P = 0.001) and lower 2-h (P = 0.001) glucose levels and to greater height and fat-free mass (P <0.001). All OGTT-derived measures of insulin sensitivity, but only one of three measures of -cell function, reflected the differences for these parameters between those with normal and impaired glucose regulation as measured by gold-standard tests.CONCLUSIONSGlucose absorption patterns during an OGTT are significantly related to plasma glucose levels and body size, which should be taken into account when estimating -cell function from OGTTs in epidemiological studies.

  1. Development of Analogy Experiment Methodologies

    International Nuclear Information System (INIS)

    Hydrogen is expected to help address concerns about global climate change and energy security. The HTGR (High-Temperature Gas-cooled Reactor) drew attention as one of the most competitive heat source for producing hydrogen. The knowledge of detailed heat transfer phenomena in gaseous phase emerges as an important factor for HTGR, where buoyancy effect plays a significant role. Large and expensive test facilities are to be constructed to assess the detailed mixed convection phenomena. However, using analogy concept, heat transfer system can be transformed to mass transfer system(copper electroplating system) and vice versa. If we could devise simple mass transfer system and find experimental solution from that system, then theoretically it is not difficult to find solution for similar heat transfer system. This study explores the applicability of simple mass transfer experiments to heat transfer researches using analogy concept. A copper electroplating system with limiting current technique has a good advantage to simulate heat transfer system as mass transfer coefficient, analogous with heat transfer coefficient, can be directly obtained from the information of the bulk concentration and electric current between electrodes. Therefore, the validity of the analogy experimental method was confirmed through comparison between the test results obtained by measuring limiting current and corresponding well-known heat transfer correlations. Three different forced and natural convection mass transfer systems were constructed to simulate Poiseuille flow at horizontal geometry and laminar and turbulent buoyant flows at vertical geometry. it was shown that the close agreement between results for mass transfer experiment and heat transfer correlation is an encouraging indication of the validity of the analogy theory and the experiment method. It may also be concluded that analogy method using electroplating system make it possible to predict the unknown heat transfer correlations. Thus, Analogy methodology is expected to be a useful tool for heat transfer studies for HTGR development as the electroplating method not only provide with useful information on heat transfer but also has cost-effective advantage than any other experiments

  2. Glucose effectiveness and insulin sensitivity measurements derived from the non-insulin-assisted minimal model and the clamp techniques are concordant

    DEFF Research Database (Denmark)

    Henriksen, Jan Erik; Alford, Frank; Ward, Glenn; Thye-Rønn, Peter; Levin, Klaus; Hother-Nielsen, Ole; Rantzau, Christian; Boston, Ray; Beck-Nielsen, Henning

    2010-01-01

    We investigated the concordance between glucose effectiveness (SG) and insulin sensitivity (SI), derived from the unmodified dynamic non-insulin-assisted intravenous glucose tolerance test (IVGTT) implemented by SG(MM) and SI(MM); simulation analysis and modelling/conversational interaction (SAAM...

  3. Glucose effectiveness and insulin sensitivity measurements derived from the non-insulin-assisted minimal model and the clamp techniques are concordant

    DEFF Research Database (Denmark)

    Henriksen, Jan Erik; Alford, Frank; Ward, Glenn; Thye-Rønn, Peter; Levin, Klaus; Hother-Nielsen, Ole; Rantzau, Christian; Boston, Ray; Beck-Nielsen, Henning

    2010-01-01

    We investigated the concordance between glucose effectiveness (SG) and insulin sensitivity (SI), derived from the unmodified dynamic non-insulin-assisted intravenous glucose tolerance test (IVGTT) implemented by SG(MM) and SI(MM); simulation analysis and modelling/conversational interaction (SAAM/CONSAM) versus the eu/hyperglycaemic basal insulinaemic and the euglycaemic hyperinsulinaemic clamp (SG(CLAMP) and SI(CLAMP)).

  4. Challenges in Analogical Reasoning

    CERN Document Server

    Lin, Shih-Yin

    2016-01-01

    Learning physics requires understanding the applicability of fundamental principles in a variety of contexts that share deep features. One way to help students learn physics is via analogical reasoning. Students can be taught to make an analogy between situations that are more familiar or easier to understand and another situation where the same physics principle is involved but that is more difficult to handle. Here, we examine introductory physics students' ability to use analogies in solving problems involving Newton's second law. Students enrolled in an algebra-based introductory physics course were given a solved problem involving tension in a rope and were then asked to solve another problem for which the physics is very similar but involved a frictional force. They were asked to point out the similarities between the two problems and then use the analogy to solve the friction problem.

  5. Analogy in Thomism.

    Czech Academy of Sciences Publication Activity Database

    Dvo?ák, Petr

    Heusenstamm : Ontos Verlag, 2010 - ( Schumann , A.), s. 164-191 ISBN 978-3-86838-061-3 Institutional research plan: CEZ:AV0Z90090514 Keywords : analogy * Thomism * semantics Subject RIV: AA - Philosophy ; Religion

  6. Analog synthetic biology

    OpenAIRE

    Sarpeshkar, R.

    2014-01-01

    We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on...

  7. Glucose kinetics in infants of diabetic mothers

    International Nuclear Information System (INIS)

    Glucose kinetic studies were performed to define the glucose turnover rate with 78% enriched D-[U-13C] glucose by the prime constant infusion technique at less than or equal to 6 hours of age in nine infants of diabetic mothers (four insulin-dependent and five chemical diabetic patients) at term. Five normal infants were studied as control subjects. All infants received 0.9% saline intravenously during the study with the tracer. Fasting plasma glucose, insulin, and glucose13/12C ratios were measured during the steady state, and the glucose turnover rate was derived. The average plasma glucose concentration was similar during the steady state in the infants of the diabetic mothers and in the control infants, and the glucose turnover rate was not significantly different among the groups: 2.3 +/- 0.6 mg . kg-1 min-1 in infants of insulin-dependent diabetic patients; 2.4 +/- 0.4 mg . kg-1 min-1 in infants of chemical diabetic patients; and 3.2 +/- 0.3 mg . kg-1 min-1 in the control subjects. Good control of maternal diabetes evidenced by the normal maternal hemoglobin A1c and plasma glucose concentration at delivery and cord plasma glucose concentration resulted in glucose kinetic values in the infants of diabetic mothers that were indistinguishable from those of control subjects. The data further support the importance of good control of the diabetic state in the pregnant woman to minimize or prevent neonatal hypoglycemia

  8. Glucose metabolism in diabetic blood vessels

    International Nuclear Information System (INIS)

    Since glycolysis appears to be coupled to active ion transport in vascular smooth muscle, alterations in glucose metabolism may contribute to cellular dysfunction and angiopathy in diabetes. Uptake and utilization of glucose were studied in perfused blood vessels in which pulsatile flow and perfusion pressure were similar to those measured directly in vivo. Thoracic aortae isolated from 8-wk alloxan diabetic (D) and nondiabetic control rabbits were cannulated, tethered, and perfused with oxygenated buffer containing 7 or 25 mM glucose and tracer amounts of glucose-U-14 C. Norepinephrine (NE) (10-6 M) and/or insulin (I) (150 ?U/ml) and albumin (0.2%) were added. NE-induced tension development increased glucose uptake 39% and 14CO2 and lactate production 2.3-fold. With 7 mM glucose, marked decreases in glucose uptake (74%), 14CO2 (68%), lactate (30%), total tissue glycogen (75%), and tissue phospholipids (70%) were observed in D. Addition of I or elevation of exogenous glucose to 25 mM normalized glucose uptake, but had differential effects on the pattern of substrate utilization. Thus, in D, there was a marked depression of vascular glucose metabolism that was partially reversed by addition of low concentrations of insulin or D levels of glucose

  9. Glucose kinetics in infants of diabetic mothers

    Energy Technology Data Exchange (ETDEWEB)

    Cowett, R.M.; Susa, J.B.; Giletti, B.; Oh, W.; Schwartz, R.

    1983-08-01

    Glucose kinetic studies were performed to define the glucose turnover rate with 78% enriched D-(U-13C) glucose by the prime constant infusion technique at less than or equal to 6 hours of age in nine infants of diabetic mothers (four insulin-dependent and five chemical diabetic patients) at term. Five normal infants were studied as control subjects. All infants received 0.9% saline intravenously during the study with the tracer. Fasting plasma glucose, insulin, and glucose13/12C ratios were measured during the steady state, and the glucose turnover rate was derived. The average plasma glucose concentration was similar during the steady state in the infants of the diabetic mothers and in the control infants, and the glucose turnover rate was not significantly different among the groups: 2.3 +/- 0.6 mg . kg-1 min-1 in infants of insulin-dependent diabetic patients; 2.4 +/- 0.4 mg . kg-1 min-1 in infants of chemical diabetic patients; and 3.2 +/- 0.3 mg . kg-1 min-1 in the control subjects. Good control of maternal diabetes evidenced by the normal maternal hemoglobin A1c and plasma glucose concentration at delivery and cord plasma glucose concentration resulted in glucose kinetic values in the infants of diabetic mothers that were indistinguishable from those of control subjects. The data further support the importance of good control of the diabetic state in the pregnant woman to minimize or prevent neonatal hypoglycemia.

  10. Insulin regulation of renal glucose metabolism in conscious dogs.

    OpenAIRE

    Cersosimo, E; Judd, R L; Miles, J M

    1994-01-01

    Previous studies indicating that postabsorptive renal glucose production is negligible used the net balance technique, which cannot partition simultaneous renal glucose production and glucose uptake. 10 d after surgical placement of sampling catheters in the left renal vein and femoral artery and a nonobstructive infusion catheter in the left renal artery of dogs, systemic and renal glucose and glycerol kinetics were measured with peripheral infusions of [3-3H]glucose and [2-14C]glycerol. Aft...

  11. Electrical Circuits and Water Analogies

    Science.gov (United States)

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  12. FRET-based glucose monitoring for bioprocessing

    Science.gov (United States)

    Bartolome, Amelita; Smalls-Mantey, Lauren; Lin, Debora; Rao, Govind; Tolosa, Leah

    2006-02-01

    The glucose-mediated conformational changes in the glucose binding protein (GBP) have been exploited in the development of fluorescence based glucose sensors. The fluorescence response is generated by a polarity sensitive dye attached to a specific site. Such fluorescent sensors respond to submicromolar glucose at diffusion-controlled rates mimicking the wild type. However, such sensors have been limited to in vitro glucose sensing because of the preliminary dye-labeling step. In the study described here, the dye-labeling step is omitted by genetically encoding the GBP with two green fluorescent mutants namely, the green fluorescent protein (GFP) and the yellow fluorescent protein (YFP) in the N- and C-terminal ends, respectively. These two GFP mutants comprise a fluorescence resonance energy transfer (FRET) donor and acceptor pair. Thus, when glucose binds with GBP, the conformational changes affect the FRET efficiency yielding a dose-dependent response. A potential application for this FRET-based glucose biosensor is online glucose sensing in bioprocessing and cell culture. This was demonstrated by the measurement of glucose consumption in yeast fermentation. Further development of this system should yield in vivo measurement of glucose in bioprocesses.

  13. Prognostic significance of the Complex "Visceral Adiposity Index" vs. simple anthropometric measures: Tehran lipid and glucose study

    Directory of Open Access Journals (Sweden)

    Mohammadreza Bozorgmanesh

    2012-03-01

    Full Text Available Abstract Background Visceral adiposity index (VAI has recently been suggested to be used as a surrogate of visceral adiposity. We examined if VAI could improve predictive performances for CVD of the Framingham's general CVD algorithm (a multivariate model incorporating established CVD risk factors. We compared the predictive abilities of the VAI with those of simple anthropometric measures i.e. BMI, waist-to-height ratio (WHtR or waist-to-hip ratio (WHpR. Design and methods In a nine-year population-based follow-up, 6 407 (2 778 men participants, free of CVD at baseline, aged ? 30 years were eligible for the current analysis. The risk of CVD was estimated by incorporating VAI, BMI, WHpR, and WHtR, one at a time, into multivariate accelerated failure time models. Results We documented 534 CVD events with the annual incidence rate (95%CIs being 7.3 (6.4-8.3 among women and 13.0 (11.7-14.6 among men. Risk of future CVD increased with increasing levels of VAI among both men and women. VAI was associated with multivariate-adjusted increased risk of incident CVD among women. However, the magnitude of risk conferred by VAI was not significantly higher than those conferred by BMI, WHpR, or WHtR. Among men, after adjustment for established CVD risk factors, VAI was no longer associated with increased risk of CVD. VAI failed to add to the predictive ability of the Framingham general CVD algorithm. Conclusions Using VAI instead of simple anthropometric measures may lead to loss of much information needed for predicting incident CVD.

  14. On employing a translationally controlled tumor protein-derived protein transduction domain analog for transmucosal delivery of drugs.

    Science.gov (United States)

    Bae, Hae-duck; Lee, Kyunglim

    2013-09-28

    Protein transduction domains (PTDs) are recognized as promising vehicles for the delivery of macromolecular drugs. We have previously shown that a region in the N-terminus (residues 1-10) of translationally controlled tumor protein (TCTP) contains a PTD (TCTP-PTD), MIIYRDLISH, which can serve as a vehicle for the delivery of macromolecules into the cells and tissues. In the current study, we evaluated the potential and safety of TCTP-PTD and its three mutant analogs as nasal absorption enhancers for delivery of drugs. We conducted this evaluation employing insulin as test drug. We examined the degree to which insulin was absorbed in nasal mucosa and also if any mucosal damage occurs following such nasal delivery of insulin using TCTP-PTDs as a vehicle. The systemic delivery of insulin was assessed by measuring the changes in blood glucose levels after nasal coadministration insulin and four PTDs. Of the three TCTP-PTD analogs examined, one, TCTP-PTD analog (MIIFRALISHKK) significantly enhanced the nasal absorption of insulin in both normal and streptozotocin-induced diabetic mice. The relative pharmacological bioavailability of insulin nasally coadministered with the TCTP-PTD analog was 21.3% relative to the subcutaneous route. Molecular association between insulin and the TCTP-PTD analog was observed by fluorescence resonance energy transfer measurements. The binding between the TCTP-PTD analog and insulin may enable the penetration of insulin through the nasal mucosa. Histological examination of mice nasal mucosa 7 days after repeated nasal administration showed no evidence of toxicity at the site of nasal administration. In this study using insulin as a test system we demonstrate that the TCTP-PTD analog offers a promising approach for nasal peptides and protein-drugs delivery. PMID:23791976

  15. The effect of glucose stimulation on 45calcium uptake of rat pancreatic islets and their total calcium content as measured by a fluorometric micro-method

    International Nuclear Information System (INIS)

    Glucose-stimulated 45calcium uptake and total calcium content of rat pancreatic islets has been studied, using a new fluorometric micro-method to estimate total calcium. Extracellular calcium was separated from incubated tissue by a rapid micro-filtration procedure. Islets incubated up to 60 min with calcium chloride 2.5 mmol/l and glucose 2.5 mmol/l maintained the same calcium content (670 +- 7.5 pmol/?g DNA). When the glucose concentration was raised to 15 mmol/l no change in the total calcium content could be detected. On incubation with glucose 2.5 mmol/l in the absence of calcium, the calcium content decreased to 488 +- 27 pmol/?g DNA. On incubation with 45calcium chloride 2.5 mmol/l for 5 or 30 min at 2.5 mmol/l glucose, islets exchanged 21 +- 2 and 28 +- 1% of their total calcium content and, at 15 mmol/l glucose, 30 +- 3 and 45 +- 2%, respectively. Thus, islet calcium has a high turn-over rate. Glucose stimulation results in an increase of the calcium uptake without enhancing the total calcium content and hence must increase the calcium-exchangeable pool. (orig.)

  16. Mechanism of Insulin-resistant Glucose Transport Activity in the Enlarged Adipose Cell of the Aged, Obese Rat: RELATIVE DEPLETION OF INTRACELLULAR GLUCOSE TRANSPORT SYSTEMS

    OpenAIRE

    Hissin, Paul J.; Foley, James E; Wardzala, Lawrence J.; Karnieli, Eddy; Simpson, Ian A.; Salans, Lester B.; Cushman, Samuel W.

    1982-01-01

    The effects of increasing cell size on glucose transport activity and metabolism and on the concentrations of glucose transport systems in both the plasma and low density microsomal membranes in isolated adipose cells from the aging rat model of obesity have been examined. Glucose transport activity was assessed by measuring l-arabinose transport and the concentration of glucose transport systems estimated by measuring specific d-glucose-inhibitable cytochalasin B-binding. Basal glucose trans...

  17. pH-Insensitive Glucose Indicators

    OpenAIRE

    Garrett, Jared R.; Wu, Xinxin; Jin, Sha; Ye, Kaiming

    2008-01-01

    There is an urgent need for developing a biosensor that can real-time and noninvasively determine glucose concentration within living cells. In our previous study, we have engineered a glucose indicator protein (GIP) that can provide continuous glucose monitoring through a conformation change-induced Förster resonance-energy transfer measurement. Because of the pH-sensitivity of the fluorescent proteins used in the GIP construction, the GIP made from these fluorescent proteins is less toleran...

  18. Alternations in salivary glucose during ramadan fasting

    OpenAIRE

    Ali Erfani; Reyhaneh Sariri; Abdolali Varasteh

    2010-01-01

    During the holly month of Ramadan, Muslims fast every day from dawn to sunset. Although the effect of Ramadan fasting on general health has been widely studied, the impact of fasting on oral health and possible changes in salivary biochemicals, such as glucose, has not received much attentiom. The aim of our study was to evaluate the influence of fasting on the level of glucose in the saliva of healthy individuals. Salivary glucose was measured using an enzymatic method based on oxidation of ...

  19. Neuronal GLP1R mediates liraglutide’s anorectic but not glucose-lowering effect

    OpenAIRE

    Sisley, Stephanie; Gutierrez-Aguilar, Ruth; Scott, Michael; D’alessio, David A.; Darleen A. Sandoval; Seeley, Randy J.

    2014-01-01

    Glucose control and weight loss are cornerstones of type 2 diabetes treatment. Currently, only glucagon-like peptide-1 (GLP1) analogs are able to achieve both weight loss and glucose tolerance. Both glucose and body weight are regulated by the brain, which contains GLP1 receptors (GLP1R). Even though the brain is poised to mediate the effects of GLP1 analogs, it remains unclear whether the glucose- and body weight–lowering effects of long-acting GLP1R agonists are via direct action on CNS GLP...

  20. Four grams of glucose

    OpenAIRE

    Wasserman, David H.

    2008-01-01

    Four grams of glucose circulates in the blood of a person weighing 70 kg. This glucose is critical for normal function in many cell types. In accordance with the importance of these 4 g of glucose, a sophisticated control system is in place to maintain blood glucose constant. Our focus has been on the mechanisms by which the flux of glucose from liver to blood and from blood to skeletal muscle is regulated. The body has a remarkable capacity to satisfy the nutritional need for glucose, while ...

  1. Imaging atherosclerosis in the carotid arteries with F-18-Fluoro-2-deoxy-D-glucose positron emission tomography: effect of imaging time after injection on quantitative measurement

    International Nuclear Information System (INIS)

    To compare F-18-fluoro-2-deoxy-D-glucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) imaging at two different circulation times after injection of F-18 FDG in order to measure atherosclerosis in carotid arteries. We assessed 12 patients with recent symptomatic plaques in the carotid arteries. F-18 FDG PET/CT carotid plaque imaging was performed for 20 min at 2 h after F-18 FDG injection in five patients and at 3 h in seven patients. We measured vessel wall uptake using the maximal standardized uptake value (SUV), and the mean and maximal blood target-to-background ratios (TBR) of the symptomatic carotid arteries. Blood pool activity (BPA) was measured as the mean SUV of the superior vena cava (SVC) and jugular vein of these 12 patients, and in 14 age-and gender-matched patients who underwent whole-body F-18 FDG PET/CT examinations 1 h after injection. F-18 FDG PET/CT revealed visible F-18 FDG uptake in all patients with symptomatic carotid plaques. Maximal SUV did not differ between groups evaluated at 2 h and 3 h (2.62±0.45 vs 3.00±0.85, p=0.335). However mean (2.04±0.22 vs 3.54±0.62, p<0.05) and maximal (1.65±0.15 vs 2.70±0.42, p<0.05) TBR values that were normalized to BPA in the SVC differ significantly. Symptomatic carotid plaques are visualized for a relatively short period of imaging time on ?1-h PET/CT images. Quantitative parameters of atherosclerotic carotid arteries are preserved or even increased over time, whereas those of blood pools are decreased

  2. Detecting early kidney damage in horses with colic by measuring matrix metalloproteinase -9 and -2, other enzymes, urinary glucose and total proteins

    Directory of Open Access Journals (Sweden)

    Salonen Hanna

    2007-01-01

    Full Text Available Abstract Background The aim of the study was to investigate urine matrix metalloproteinase (MMP-2 and -9 activity, alkaline phosphatase/creatinine (U-AP/Cr and gamma-glutamyl-transpeptidase/creatinine (U-GGT/Cr ratios, glucose concentration, and urine protein/creatinine (U-Prot/Cr ratio and to compare data with plasma MMP-2 and -9 activity, cystatin-C and creatinine concentrations in colic horses and healthy controls. Horses with surgical colic (n = 5 were compared to healthy stallions (n = 7 that came for castration. Blood and urine samples were collected. MMP gelatinolytic activity was measured by zymography. Results We found out that horses with colic had significantly higher urinary MMP-9 complex and proMMP-9 activities than horses in the control group. Colic horses also had higher plasma MMP-2 activity than the control horses. Serum creatinine, although within reference range, was significantly higher in the colic horses than in the control group. There was no significant increase in urinary alkaline phosphatase, gamma-glutamyltranspeptidase or total proteins in the colic horses compared to the control group. A human cystatin-C test (Dako Cytomation latex immunoassay® based on turbidimetry did not cross react with equine cystatin-C. Conclusion The results indicate that plasma MMP-2 may play a role in the pathogenesis of equine colic and urinary MMP-9 in equine kidney damage.

  3. Digital and analog communication systems

    Science.gov (United States)

    Shanmugam, K. S.

    1979-01-01

    The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

  4. Electrical analogous in viscoelasticity

    Science.gov (United States)

    Ala, Guido; Di Paola, Mario; Francomano, Elisa; Li, Yan; Pinnola, Francesco P.

    2014-07-01

    In this paper, electrical analogous models of fractional hereditary materials are introduced. Based on recent works by the authors, mechanical models of materials viscoelasticity behavior are firstly approached by using fractional mathematical operators. Viscoelastic models have elastic and viscous components which are obtained by combining springs and dashpots. Various arrangements of these elements can be used, and all of these viscoelastic models can be equivalently modeled as electrical circuits, where the spring and dashpot are analogous to the capacitance and resistance, respectively. The proposed models are validated by using modal analysis. Moreover, a comparison with numerical experiments based on finite difference time domain method shows that, for long time simulations, the correct time behavior can be obtained only with modal analysis. The use of electrical analogous in viscoelasticity can better reveal the real behavior of fractional hereditary materials.

  5. Analog layout synthesis

    CERN Document Server

    Graeb, Helmut E

    2010-01-01

    Integrated circuits are fundamental electronic components in biomedical, automotive and many other technical systems. A small, yet crucial part of a chip consists of analog circuitry. This part is still in large part designed by hand and therefore represents not only a bottleneck in the design flow, but also a permanent source of design errors responsible for re-designs, costly in terms of wasted test chips and in terms of lost time-to-market. Layout design is the step of the analog design flow with the least support by commercially available, computer-aided design tools. This book provides a

  6. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To Know Your Risk Alert Day ... DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Step On Up Treatment & Care Blood Glucose Testing ...

  7. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools ... Complications Neuropathy Foot Complications DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Treatment & Care Blood Glucose ...

  8. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... blood glucose High levels of sugar in the urine Frequent urination Increased thirst Part of managing your ... glucose is above 240 mg/dl, check your urine for ketones. If you have ketones, do not ...

  9. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To Know Your Risk Alert Day ... DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Treatment & Care Blood Glucose Testing Medication Doctors, Nurses & ...

  10. Impact of Glucose Tolerance Status, Sex, and Body Size on Glucose Absorption Patterns During OGTTs

    DEFF Research Database (Denmark)

    Faerch, K.; Pacini, G.; Nolan, J. J.; Hansen, Torben; Tura, A.; Vistisen, D.

    2013-01-01

    size were taken into account (P > 0.28). Faster glucose absorption was related to higher fasting (P = 0.001) and lower 2-h (P = 0.001) glucose levels and to greater height and fat-free mass (P <0.001). All OGTT-derived measures of insulin sensitivity, but only one of three measures of -cell function......, reflected the differences for these parameters between those with normal and impaired glucose regulation as measured by gold-standard tests.CONCLUSIONSGlucose absorption patterns during an OGTT are significantly related to plasma glucose levels and body size, which should be taken into account when...

  11. The Global Precipitation Measurement (GPM) Microwave Imager Polarimetric (GMI-P); 10 - 183 GHz with Polarimetric channels including digital and analog back-ends: Ardeshir Art Azarbarzin, Sergey Krimchansky Jeff Piepmeir NASA Goddard Space Flight Center, Greenbelt, MD 20771 USA

    Science.gov (United States)

    Azarbarzin, A.

    2014-12-01

    The Global Precipitation Measurement (GPM) Microwave Imager Polarimetric (GMI-P) will be an instrument covering 10, 18, 23, 36, 89, 166 and 183 GHz with polarimetric channels on 10, 18 and 36 GHz channels. The GMI-P (or VWPIR) will have 13 analog channels and 12 digital channels. This instrument builds upon the success of GPM Microwave Imager (GMI) flying on the Global Precipitation Measurement (GPM) launched in Feb 2014. And with GMI-P for the first time we can compare performance of digital and analog channels for 10, 18 and 36 channels. The GMI-P is recently renamed "Vector Wind Precipitation Imaging Radiometer (VWPIR). The instrument is a passive microwave with 1.2 m diameter reflector with 4-point hot/cold calibration capability in orbit. GMI-P (VWPIR) will provides measurements of precipitation intensity and distribution in addition to wind vector and speed. The Receivers, and multiple feedhorn tray rotate with the reflector at 32 RPM. The GMI-P will have capabilities as good as Windsat with added cyclone intensity and snow/ice measurement capability. This instrument will have a 2-Look capability (front and back) as well which will reduce uncertainty of reducing calibration accuracy further.

  12. Radiometric assays for glycerol, glucose, and glycogen

    International Nuclear Information System (INIS)

    We have developed radiometric assays for small quantities of glycerol, glucose and glycogen, based on a technique described by Thorner and Paulus for the measurement of glycerokinase activity. In the glycerol assay, glycerol is phosphorylated with [32P]ATP and glycerokinase, residual [32P]ATP is hydrolyzed by heating in acid, and free [32P]phosphate is removed by precipitation with ammonium molybdate and triethylamine. Standard dose-response curves were linear from 50 to 3000 pmol glycerol with less than 3% SD in triplicate measurements. Of the substances tested for interference, only dihydroxyacetone gave a slight false positive signal at high concentration. When used to measure glycerol concentrations in serum and in media from incubated adipose tissue, the radiometric glycerol assay correlated well with a commonly used spectrophotometric assay. The radiometric glucose assay is similar to the glycerol assay, except that glucokinase is used instead of glycerokinase. Dose response was linear from 5 to 3000 pmol glucose with less than 3% SD in triplicate measurements. Glucosamine and N-acetylglucosamine gave false positive signals when equimolar to glucose. When glucose concentrations in serum were measured, the radiometric glucose assay agreed well with hexokinase/glucose-6-phosphate dehydrogenase (H/GDH)-based and glucose oxidase/H2O2-based glucose assays. The radiometric method for glycogen measurement incorporates previously described isolation and digestion techniques, followed by the radiometric assay of free glucose. When used to measure glycogen in mouse epididymal fat pads, the radiometric glycogen assay correlated well with the H/GDH-based glycogen assay. All three radiometric assays offer several practical advantages over spectral assays

  13. 21 CFR 864.7360 - Erythrocytic glucose-6-phosphate dehydrogenase assay.

    Science.gov (United States)

    2010-04-01

    ...Erythrocytic glucose-6-phosphate dehydrogenase assay. 864.7360 Section 864.7360 Food...Erythrocytic glucose-6-phosphate dehydrogenase assay. (a) Identification. An erythrocytic glucose-6-phosphate dehydrogenase assay is a device used to measure the...

  14. How Analogy Drives Physics

    International Nuclear Information System (INIS)

    Many new ideas in theoretical physics come from analogies to older ideas in physics. For instance, the abstract notion of 'isospin' (or isotopic spin) originated in the prior concept of 'spin' (quantized angular momentum); likewise, the concept of 'phonon' (quantum of sound, or quantized collective excitation of a crystal) was based on the prior concept of 'photon' (quantum of light, or quantized element of the electromagnetic field). But these two examples, far from being exceptions, in fact represent the bread and butter of inventive thinking in physics. In a nutshell, intraphysics analogy-making -- borrowing by analogy with something already known in another area of physics -- is central to the progress of physics. The aim of this talk is to reveal the pervasiveness -- indeed, the indispensability -- of this kind of semi-irrational, wholly intuitive type of thinking (as opposed to more deductive mathematical inference) in the mental activity known as 'doing physics'. Speculations as to why wild analogical leaps are so crucial to the act of discovery in physics (as opposed to other disciplines) will be offered.

  15. Analog random coding

    International Nuclear Information System (INIS)

    We investigate numerically the ''analog random coding'' problem, where a vector x element of RN, encrypted by an N by M random matrix W, is transmitted to a remote receiver, over a noisy channel. We show that for M>>N, it is in fact possible to recover the original signal with very high accuracy, even for an extremely high level of noise

  16. Towards analogy in toponyms.

    Czech Academy of Sciences Publication Activity Database

    Št?pán, Pavel

    Cluj : Mega, 2013 - (Felecan, O.), s. 379-383 ISBN 978-606-543-343-4. [Name and Naming /2./ Onomastics in Contemporary Public Space. Baia Mare (RO), 09.05.2013-11.05.2013] R&D Projects: GA ?R GPP406/12/P600 Institutional support: RVO:68378092 Keywords : onomastics * toponyms * analogy Subject RIV: AI - Linguistics

  17. Quantum Analog Computing

    Science.gov (United States)

    Zak, M.

    1998-01-01

    Quantum analog computing is based upon similarity between mathematical formalism of quantum mechanics and phenomena to be computed. It exploits a dynamical convergence of several competing phenomena to an attractor which can represent an externum of a function, an image, a solution to a system of ODE, or a stochastic process.

  18. Radiotracers in the study of marine food chains. The use of compartmental analysis and analog modelling in measuring utilization rates of particulate organic matter by benthic invertebrates

    International Nuclear Information System (INIS)

    The present study assesses the problem of recycling when using radiotracers to quantify ingestion and assimilation rates of particulate organic matter by benthic invertebrates. The rapid production of dissolved organic matter and its subsequent utilization by benthic invertebrates constitutes a major bias in this kind of study. However recycling processes may also concern POM through the production and reingestion of faeces. The present paper shows that compartmental analysis of the diffusion kinetics of the radiotracer between the different compartments of the system studied and the analog modelling of the exchanges of radioactivity between compartments may be used in order to determine ingestion and assimilation rates. This method is illustrated by the study of a system composed of the bacteria Lactobacillus sp. and the filter-feeding bivalve Venerupis decussata. The advantages and drawbacks of this approach relative to other existing methods are briefly discussed. (Author)

  19. Detecção de trombose venosa em retalhos livres por medidas de glicemia capilar Detection of venous thrombosis in free flaps by measurement of capillary blood glucose

    Directory of Open Access Journals (Sweden)

    Lincoln Saito Millan

    2012-12-01

    Full Text Available INTRODUÇÃO: A monitorização do retalho livre após a cirurgia é de vital importância, especialmente nas primeiras horas de pós-operatório, pois o momento de reabordagem pode ser o definidor entre o salvamento ou a perda do retalho. Até o momento, não existe trabalho na literatura estudando a decisão de abordagem do retalho baseada em medidas objetivas ou a comparação da glicemia entre retalhos que evoluíram bem com os que sofreram sofrimento vascular. O objetivo deste estudo é avaliar a validade da medida da glicemia capilar do retalho como método de monitorização de retalhos microcirúrgicos comparando com a avaliação clínica. MÉTODO: Foram estudados prospectivamente 16 pacientes portadores de retalhos livres, realizados de maio de 2012 a julho de 2012. A glicemia capilar foi avaliada por equipe formada por profissionais não envolvidos com a cirurgia realizada. A avaliação clínica do retalho foi realizada no pós-operatório imediato, na chegada à UTI, a cada 3 horas e sempre que necessário. RESULTADOS: Dos 16 pacientes, 5 (31,3% apresentaram complicações nas primeiras 24 horas. Todas as complicações observadas foram trombose venosa. Foi observada diferença estatisticamente significante na glicemia capilar de portadores de retalhos que apresentaram trombose venosa em comparação àqueles que não tiveram a complicação, nas medidas realizadas 6 horas, 9 horas e 12 horas após a operação (P BACKGROUND: Monitoring of free flaps after surgery is vitally important, especially in the first few hours because the timing of reoperation can determine flap salvage or loss. To date, no study has examined the decision to reoperate on a flap based on the objective measure of glycemia or a comparison between flaps that showed good outcomes and those that showed vascular damage. The objective of this study was to evaluate the validity of blood glucose measurements within the flap as a method for monitoring free flaps and to compare the efficacy of this method with that of clinical assessments. METHODS: The study was prospective, included 16 patients with free flaps, and was conducted from May 2012 to July 2012. A team of professionals not involved in the surgery evaluated capillary glycemia. Flaps were clinically evaluated during the immediate postoperative period, on ICU admission, at every 3 hours, and as needed. RESULTS: Of the 16 patients, 5 (31.3% had venous thrombosis in the first 24 hours. Statistically significant differences were noted in capillary glycemia in patients with or without venous thrombosis in measurements obtained 6, 9, and 12 hours after surgery (P < 0.05. CONCLUSIONS: The measurement of capillary glycemia was not superior to clinical evaluation by an experienced professional for the detection of venous thrombosis within free flaps.

  20. KETONES SUPPRESS BRAIN GLUCOSE CONSUMPTION

    Science.gov (United States)

    LaManna, Joseph C.; Salem, Nicolas; Puchowicz, Michelle; Erokwu, Bernadette; Koppaka, Smruta; Flask, Chris; Lee, Zhenghong

    2010-01-01

    The brain is dependent on glucose as a primary energy substrate, but is capable of utilizing ketones such as ?-hydroxybutyrate (?HB) and acetoacetate (AcAc), as occurs with fasting, prolonged starvation or chronic feeding of a high fat/low carbohydrate diet (ketogenic diet). In this study, the local cerebral metabolic rate of glucose consumption (CMRglu; ?M/min/100g) was calculated in the cortex and cerebellum of control and ketotic rats using Patlak analysis. Rats were imaged on a rodent PET scanner and MRI was performed on a 7-Tesla Bruker scanner for registration with the PET images. Plasma glucose and ?HB concentrations were measured and 90-minute dynamic PET scans were started simultaneously with bolus injection of 2-Deoxy-2[18F]Fluoro-D-Glucose (FDG). The blood radioactivity concentration was automatically sampled from the tail vein for 3 min following injection and manual periodic blood samples were taken. The calculated local CMRGlu decreased with increasing plasma BHB concentration in the cerebellum (CMRGlu = ?4.07*[BHB] + 61.4, r² = 0.3) and in the frontal cortex (CMRGlu = ?3.93*[BHB] + 42.7, r² = 0.5). These data indicate that, under conditions of ketosis, glucose consumption is decreased in the cortex and cerebellum by about 10% per each mM of plasma ketone bodies. PMID:19227486

  1. Underestimation of glucose turnover corrected with high-performance liquid chromatography purification of [6-3H]glucose

    International Nuclear Information System (INIS)

    We have recently reported that during infusion of commercially available [6-3H]glucose, a radioactive nonglucose contaminant may accumulate in plasma causing errors in the measurement of glucose turnover. To determine whether purification of this tracer by HPLC (high-performance liquid chromatography) before infusion would eliminate the contaminant in plasma and remove the underestimation of glucose turnover reported during hyperinsulinemia, four normal subjects each underwent two 5-h euglycemic clamps during infusion of insulin (1 mU.kg-1.min-1). Glucose turnover was measured with either commercially available [6-3H]glucose or with HPLC-purified [6-3H]glucose. HPLC analysis of samples from the clamps done with commercially available [6-3H]glucose showed that 9.7% of the infused tracer and 26% of the plasma glucose 3H radioactivity were contaminants. In contrast, no contaminant was observed in the plasma during infusion of HPLC-purified [6-3H]glucose. During the last hour of the clamp, mean glucose turnover using commercially available [6-3H]glucose was less (P less than 0.01) than the mean glucose infusion rate (7.6 +/- 0.3 vs. 10.5 +/- 0.3 mg.kg-1.min-1) yielding apparent negative (P less than 0.001) hepatic glucose release. In contrast, when HPLC-purified [6-3H]glucose was employed, glucose turnover equaled the glucose infusion rate (10.4 +/- 0.9 vs. 10.2 +/- 0.9 mg.kg-1.min-1) and hepatic glucose release was no longer negative. We conclude that removal of a tritiated nonglucose contaminant in [6-3H]glucose by HPLC yields correct estimations of glucose turnover at steady state

  2. Early change in glucose metabolic rate measured using FDG-PET in patients with high-grade glioma predicts response to temozolomide but not temozolomide plus radiotherapy

    International Nuclear Information System (INIS)

    Purpose: To compare the ability of positron emission tomography (PET) to predict response to temozolomide vs. temozolomide plus radiotherapy. Methods and Materials: Nineteen patients with high-grade glioma (HGG) were studied. Patients with recurrent glioma received temozolomide 75 mg/m2 daily for 7 weeks (n = 8). Newly diagnosed patients received temozolomide 75 mg/m2 daily plus radiotherapy 60 Gy/30 fractions over 6 weeks, followed by six cycles of adjuvant temozolomide 200 mg/m2/day (Days 1-5 q28) starting 1 month after radiotherapy (n = 11). [18F]Fluorodeoxyglucose ([18F]FDG) PET scan and magnetic resonance imaging (MRI) were performed at baseline, and 7 and 19 weeks after initiation of temozolomide administration. Changes in glucose metabolic rate (MRGlu) and MRI response were correlated with patient survival. Results: In the temozolomide-alone group, patients who survived >26 vs. ?26 weeks showed a greater reduction in MRGlu measured at 7 weeks with median changes of -34% and -4%, respectively (p = 0.02). PET responders, defined as a reduction in MRGlu ?25%, survived longer than nonresponders with mean survival times of 75 weeks (95% CI, 34-115 vs. 20 weeks (95% CI, 14-26) (p = 0.0067). In the small group of patients studied, there was no relationship between MRI response and survival (p = 0.52). For patients receiving temozolomide plus radiotherapy, there was no difference in survival between PET responders and nonresponders (p = 0.32). Conclusions: Early changes in MRGlu predict response to temozolomide, but not temozolomide plus radiotherapy

  3. Single Cell "Glucose Nanosensor" Verifies Elevated Glucose Levels in Individual Cancer Cells.

    Science.gov (United States)

    Nascimento, Raphael A S; Özel, R?fat Emrah; Mak, Wai Han; Mulato, Marcelo; Singaram, Bakthan; Pourmand, Nader

    2016-02-10

    Because the transition from oxidative phosphorylation to anaerobic glycolytic metabolism is a hallmark of cancer progression, approaches to identify single living cancer cells by their unique glucose metabolic signature would be useful. Here, we present nanopipettes specifically developed to measure glucose levels in single cells with temporal and spatial resolution, and we use this technology to verify the hypothesis that individual cancer cells can indeed display higher intracellular glucose levels. The nanopipettes were functionalized as glucose nanosensors by immobilizing glucose oxidase (GOx) covalently to the tip so that the interaction of glucose with GOx resulted in a catalytic oxidation of ?-d-glucose to d-gluconic acid, which was measured as a change in impedance due to drop in pH of the medium at the nanopipette tip. Calibration studies showed a direct relationship between impedance changes at the tip and glucose concentration in solution. The glucose nanosensor quantified single cell intracellular glucose levels in human fibroblasts and the metastatic breast cancer lines MDA-MB-231 and MCF7 and revealed that the cancer cells expressed reproducible and reliable increases in glucose levels compared to the nonmalignant cells. Nanopipettes allow repeated sampling of the same cell, as cells remain viable during and after measurements. Therefore, nanopipette-based glucose sensors provide an approach to compare changes in glucose levels with changes in proliferative or metastatic state. The platform has great promise for mechanistic investigations, as a diagnostic tool to distinguish cancer cells from nonmalignant cells in heterogeneous tissue biopsies, as well as a tool for monitoring cancer progression in situ. PMID:26752097

  4. Detecção de trombose venosa em retalhos livres por medidas de glicemia capilar / Detection of venous thrombosis in free flaps by measurement of capillary blood glucose

    Scientific Electronic Library Online (English)

    Lincoln Saito, Millan; Luiz Carlos, Ishida; Esther Mihwa Oh, Choi; Enio Cesar, Giacchetto Junior; Teng Hsiang, Wei; Rames, Mattar Júnior; Marcus Castro, Ferreira.

    2012-12-01

    Full Text Available INTRODUÇÃO: A monitorização do retalho livre após a cirurgia é de vital importância, especialmente nas primeiras horas de pós-operatório, pois o momento de reabordagem pode ser o definidor entre o salvamento ou a perda do retalho. Até o momento, não existe trabalho na literatura estudando a decisão [...] de abordagem do retalho baseada em medidas objetivas ou a comparação da glicemia entre retalhos que evoluíram bem com os que sofreram sofrimento vascular. O objetivo deste estudo é avaliar a validade da medida da glicemia capilar do retalho como método de monitorização de retalhos microcirúrgicos comparando com a avaliação clínica. MÉTODO: Foram estudados prospectivamente 16 pacientes portadores de retalhos livres, realizados de maio de 2012 a julho de 2012. A glicemia capilar foi avaliada por equipe formada por profissionais não envolvidos com a cirurgia realizada. A avaliação clínica do retalho foi realizada no pós-operatório imediato, na chegada à UTI, a cada 3 horas e sempre que necessário. RESULTADOS: Dos 16 pacientes, 5 (31,3%) apresentaram complicações nas primeiras 24 horas. Todas as complicações observadas foram trombose venosa. Foi observada diferença estatisticamente significante na glicemia capilar de portadores de retalhos que apresentaram trombose venosa em comparação àqueles que não tiveram a complicação, nas medidas realizadas 6 horas, 9 horas e 12 horas após a operação (P Abstract in english BACKGROUND: Monitoring of free flaps after surgery is vitally important, especially in the first few hours because the timing of reoperation can determine flap salvage or loss. To date, no study has examined the decision to reoperate on a flap based on the objective measure of glycemia or a comparis [...] on between flaps that showed good outcomes and those that showed vascular damage. The objective of this study was to evaluate the validity of blood glucose measurements within the flap as a method for monitoring free flaps and to compare the efficacy of this method with that of clinical assessments. METHODS: The study was prospective, included 16 patients with free flaps, and was conducted from May 2012 to July 2012. A team of professionals not involved in the surgery evaluated capillary glycemia. Flaps were clinically evaluated during the immediate postoperative period, on ICU admission, at every 3 hours, and as needed. RESULTS: Of the 16 patients, 5 (31.3%) had venous thrombosis in the first 24 hours. Statistically significant differences were noted in capillary glycemia in patients with or without venous thrombosis in measurements obtained 6, 9, and 12 hours after surgery (P

  5. Noninvasive Measurement of Murine Hepatic Acetyl-CoA 13C-Enrichment Following Overnight Feeding with 13C-Enriched Fructose and Glucose

    OpenAIRE

    Jones, John G.; Cruz, Pedro F.; Ana Rita Simoes; Filipa Carvalho; Joao Duarte

    2013-01-01

    The 13C-isotopomer enrichment of hepatic cytosolic acetyl-CoA of overnight-fed mice whose drinking water was supplemented with [U-13C]fructose, and [1-13C]glucose and p-amino benzoic acid (PABA) was quantified by 13C NMR analysis of urinary N-acetyl-PABA. Four mice were given normal chow plus drinking water supplemented with 5% [1-13C]glucose, 2.5% [U-13C]fructose, and 2.5% fructose (Solution 1) overnight. Four were given chow and water containing 17.5% [1-13C]glucose, 8.75% [U-13C]fructose a...

  6. Plasma glucose levels and flight

    Directory of Open Access Journals (Sweden)

    Tomei G

    2013-07-01

    Full Text Available Background: Noise is able to exert many adverse health effects, ranging from damages on various organs and systems to changes in biochemical and humoral markers. In literature, the effects of chronic exposure to noise on blood glucose levels have been reported, although these results are conflicting: some authors reported hyperglycaemia, others hypoglycaemia and many others recorded no changes in blood glucose levels. Objectives: Considering that the plasma glucose levels are not used as a biomarker of noise exposure, we conducted a pilot study on 6 subjects, 2 females and 4 males, working as clerks in a low noise environment in order to evaluate the possible occurrence of changes on plasma glucose levels in healthy subjects, non-diabetic and not accustomed to flight, exposed to noise and to flight-related stressors. Methods: The subjects completed a specific clinic-anamnestic questionnaire and underwent a general clinical examination. In the first phase of the study, participants underwent blood tests in order to assess the plasma glucose levels at three different times: at 8:00 a.m., on board of a turboprop transport aircraft before the take-off with the engine switched off, after 60 and 120 minutes’ flight. The second phase of the study was carried out one month after the first one and while working in the office; three blood tests were performed again, at fasting and after 60 and 120 minutes. The plasma glucose levels were measured on capillary blood by the refractometry method through the use of Glucoscan One Touch device. Results: The results show an increase of plasma glucose levels during the waiting for the flight and a statistically significant decrease of plasma glucose levels in the first hour of flight (p <0.001, persisting even at the second hour (p <0.001. No significant changes were found in the blood tests performed at work. Discussion: The data show an initial hyperglycaemic response, followed by a persistent and moderate decrease of glycaemia; a similar response was not observed in the same subjects during ordinary work activities. The Authors believe that the initial increase of the plasma glucose levels, recorded in absence of noise on board, could be related to the response to other stressors, such as anxiety linked to the waiting for the flight. The decrease of the plasma glucose levels observed after 60 and 120 minutes’ flight, that is in conditions of prolonged exposure to flight-related stressors and to noise, may be linked to the intervention of several mechanisms: partial phenomenon of adaptation-exhaustion of the neuroendocrine response to stress; hypoglycaemic effect of noise, CCK-mediated and VIP-mediated with consequent insulin release and decrease of the plasma glucose levels; synergistic action of the above mechanisms. The absence of changes on the plasma glucose levels during the usual work activity is probably due to the absence of those stressors considered able to induce the alterations of the plasma glucose levels recorded during the first phase of the study. Conclusions: These preliminary results suggest that exposure to flight-related stressors and in particular exposure to noise can cause a hypoglycaemic response.

  7. Statins Impair Glucose Uptake in Tumor Cells

    Directory of Open Access Journals (Sweden)

    Agata Malenda

    2012-04-01

    Full Text Available Statins, HMG-CoA reductase inhibitors, are used in the prevention and treatment of cardiovascular diseases owing to their lipid-lowering effects. Previous studies revealed that, by modulating membrane cholesterol content, statins could induce conformational changes in cluster of differentiation 20 (CD20 tetraspanin. The aim of the presented study was to investigate the influence of statins on glucose transporter 1 (GLUT1-mediated glucose uptake in tumor cells. We observed a significant concentration- and time-dependent decrease in glucose analogs' uptake in several tumor cell lines incubated with statins. This effect was reversible with restitution of cholesterol synthesis pathway with mevalonic acid as well as with supplementation of plasma membrane with exogenous cholesterol. Statins did not change overall GLUT1 expression at neither transcriptional nor protein levels. An exploratory clinical trial revealed that statin treatment decreased glucose uptake in peripheral blood leukocytes and lowered 18F-fluorodeoxyglucose (18F-FDG uptake by tumor masses in a mantle cell lymphoma patient. A bioinformatics analysis was used to predict the structure of human GLUT1 and to identify putative cholesterol-binding motifs in its juxtamembrane fragment. Altogether, the influence of statins on glucose uptake seems to be of clinical significance. By inhibiting 18F-FDG uptake, statins can negatively affect the sensitivity of positron emission tomography, a diagnostic procedure frequently used in oncology.

  8. An NFC-Enabled CMOS IC for a Wireless Fully Implantable Glucose Sensor.

    Science.gov (United States)

    DeHennis, Andrew; Getzlaff, Stefan; Grice, David; Mailand, Marko

    2016-01-01

    This paper presents an integrated circuit (IC) that merges integrated optical and temperature transducers, optical interface circuitry, and a near-field communication (NFC)-enabled digital, wireless readout for a fully passive implantable sensor platform to measure glucose in people with diabetes. A flip-chip mounted LED and monolithically integrated photodiodes serve as the transduction front-end to enable fluorescence readout. A wide-range programmable transimpedance amplifier adapts the sensor signals to the input of an 11-bit analog-to-digital converter digitizing the measurements. Measurement readout is enabled by means of wireless backscatter modulation to a remote NFC reader. The system is able to resolve current levels of less than 10 pA with a single fluorescent measurement energy consumption of less than 1 ?J. The wireless IC is fabricated in a 0.6-?m-CMOS process and utilizes a 13.56-MHz-based ISO15693 for passive wireless readout through a NFC interface. The IC is utilized as the core interface to a fluorescent, glucose transducer to enable a fully implantable sensor-based continuous glucose monitoring system. PMID:26372659

  9. Glucose turnover, gluconeogenesis from glycerol, and estimation of net glucose cycling in cancer patients

    International Nuclear Information System (INIS)

    A double isotope method was used in patients with progressive malignancy and in control patients to measure: glucose turnover, conversion rate of carbon skeleton of glycerol into glucose, and the interorgan cycling of glucose carbons (Cori-cycle plus alanine-glucose cycle). [U-14C]glycerol and [6-3H]glucose were given intravenously as a single dose injection. The time course of the specific radioactivities of [6-3H] and [U-14C]glucose was followed in blood. The pool size and the turnover rate of glucose were increased in the cancer group as compared with the control patients. The net recycling of glucose carbons was not increased in the cancer group, despite the increased turnover of glucose. The alterations in the metabolism of glucose did not correlate with the plasma levels of insulin or thyroid hormones (T4, T3, rT3) neither in the entire cancer group nor in those cancer patients who were repeatedly investigated at different intervals of time. The turnover rate of glucose in the cancer patients correlated inversely to their body weight index. The gluconeogenesis rate, given as the fractional conversion rate of the injected radioactive dose of [14C]glycerol, or as mol glucose . kg body weight-1 . day-1, was increased in the cancer group, but still contributed only 3% of the glucose turnover rate in both cancer and control patients. We conclude that an increased gluconeogenesis from glycerol is not significant in terms of energy expenditure in patients with progressive malignancy, as has previously been concluded for the gluconeogenesis from alanine. It seems that increased turnover of glucose may contribute to inappropriately high energy expenditure in cancer patients

  10. Analogy, Explanation, and Proof

    Directory of Open Access Journals (Sweden)

    John Hummel

    2014-11-01

    Full Text Available People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic whose truth was not even known prior to the existence of the explanation (proof. What do the cognitive operations underlying the (inductive inference that the milk is sour have in common with the (deductive proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This small-seeming difference poses a challenge to the task of marshaling our understanding of analogical reasoning in the service of understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence.

  11. Antarctic analogs for Enceladus

    Science.gov (United States)

    Murray, A. E.; Andersen, D. T.; McKay, C. P.

    2014-12-01

    Enceladus is a new world for Astrobiology. The Cassini discovery of the icy plume emanating from the South Polar region indicates an active world, where detection of water, organics, sodium, and nano-particle silica in the plume strongly suggests that the source is a subsurface salty ocean reservoir. Recent gravity data from Cassini confirms the presence of a regional sea extending north to 50°S. An ocean habitat under a thick ice cover is perhaps a recurring theme in the Outer Solar System, but what makes Enceladus unique is that the plume jetting out into space is carrying samples of this ocean. Therefore, through the study of Enceladus' plumes we can gain new insights not only of a possible habitable world in the Solar Systems, but also about the formation and evolution of other icy-satellites. Cassini has been able to fly through this plume - effectively sampling the ocean. It is time to plan for future missions that do more detailed analyses, possibly return samples back to Earth and search for evidence of life. To help prepare for such missions, the need for earth-based analog environments is essential for logistical, methodological (life detection) and theoretical development. We have undertaken studies of two terrestrial environments that are close analogs to Enceladus' ocean: Lake Vida and Lake Untersee - two ice-sealed Antarctic lakes that represent physical, chemical and possibly biological analogs for Enceladus. By studying the diverse biology and physical and chemical constraints to life in these two unique lakes we will begin to understand the potential habitability of Enceladus and other icy moons, including possible sources of nutrients and energy, which together with liquid water are the key ingredients for life. Analog research such as this will also enable us to develop and test new strategies to search for evidence of life on Enceladus.

  12. A Transiting Jupiter Analog

    CERN Document Server

    Kipping, David M; Henze, Chris; Teachey, Alex; Isaacson, Howard T; Petigura, Erik A; Marcy, Geoffrey W; Buchhave, Lars A; Chen, Jingjing; Bryson, Steve T; Sandford, Emily

    2016-01-01

    Decadal-long radial velocity surveys have recently started to discover analogs to the most influential planet of our solar system, Jupiter. Detecting and characterizing these worlds is expected to shape our understanding of our uniqueness in the cosmos. Despite the great successes of recent transit surveys, Jupiter analogs represent a terra incognita, owing to the strong intrinsic bias of this method against long orbital periods. We here report on the first validated transiting Jupiter analog, Kepler-167e (KOI-490.02), discovered using Kepler archival photometry orbiting the K4-dwarf KIC-3239945. With a radius of $(0.91\\pm0.02)$ $R_{\\mathrm{Jup}}$, a low orbital eccentricity ($0.06_{-0.04}^{+0.10}$) and an equilibrium temperature of $(131\\pm3)$ K, Kepler-167e bears many of the basic hallmarks of Jupiter. Kepler-167e is accompanied by three Super-Earths on compact orbits, which we also validate, leaving a large cavity of transiting worlds around the habitable-zone. With two transits and continuous photometric ...

  13. Analog processor for electroluminescent detector

    International Nuclear Information System (INIS)

    The analog-signal processing channel of an electroluminescent gas proportional detector of soft x rays is examined. The analog processor performs the following functions: restores the dc component of the signal, since, under the operating conditions of the detector, the anode of the photomultiplier is at a positive potential, and the signals are sent through capacitors; integrates the detector signals and sends Start and Stop pulses to the time-interval-meter, the time between which is proportional to the pulse area; provides discrimination (gates) for the lower and upper levels of input-signal area; rejects signals that arrive during measurement of another; and counts the number of input pulses during a measurement cycle, which is set either from the front panel of the unit or through the CAMAC dataway. A time-interval meter or an amplitude analyzer can be used as a spectrometer. The dead time of the processor is 0.5-5 ?sec, depending on the input signal and the conversion scale

  14. Radiopharmaceuticals. XXVII. 18F-labeled 2-deoxy-2-fluoro-D-glucose as a radiopharmaceutical for measuring regional myocardial glucose metabolism in vivo: tissue distribution and imaging studies in animals

    International Nuclear Information System (INIS)

    18F-2-Deoxy-2-fluoro-D-glucose (18FDG) is rapidly extracted by the mouse heart, and the radioactivity in heart (3 to 4% per organ) remains relatively constant for 2 hr post injection. The brain uptake (2 to 3% per organ) remained relatively constant throughout the time course of the study. Liver, lungs, kidneys, small intestine, and blood all showed a rapid clearance of radioactivity after injection of 18FDG. At 120 min the heart-to-lung ratio was 12 and heart-to-liver ratio was 32. Urinary excretion of activity was approximately 16% of the injected dose at 60 min. The uptake of radioactivity by dog heart following the intravenous administration of 18FDG was 2.8 to 4.1% at 60 min and 2.4% at 135 min; it was regionally distributed, the areas of highest activity being the left ventricle and the interventricular septum. The brain activity was 2.1 to 3.5% at 120 min, with a ratio of gray matter-to-white matter of 2 to 3:1. Urinary excretion in dogs was 16% and 50% of the injected dose at 60 and 135 min. The chemical form of the activity in the urine, although unidentified, was not 18F-. Cross-sectional images of the mycardium of the dog after intravenous injection of 18FDG were obtained using emission tomography

  15. The Age of Analog Networks

    OpenAIRE

    Mattiussi, Claudio; Swiss Federal Institute of Technology in Lausanne (EPFL); Marbach, Daniel; Swiss Federal Institute of Technology in Lausanne (EPFL); Dürr, Peter; Swiss Federal Institute of Technology in Lausanne (EPFL); Floreano, Dario; Swiss Federal Institute of Technology in Lausanne (EPFL)

    2008-01-01

    A large class of systems of biological and technological relevance can be described as analog networks, that is, collections of dynamical devices interconnected by links of varying strength. Some examples of analog networks are genetic regulatory networks, metabolic networks, neural networks, analog electronic circuits, and control systems. Analog networks are typically complex systems which include nonlinear feedback loops and possess temporal dynamics at different timescales. When tackled b...

  16. Application of time gating in the measurement of glucose level in a three-layer biotissue model by using ultrashort laser pulses

    International Nuclear Information System (INIS)

    The efficiency of using the time-of-flight (TOF) method at a wavelength of 820 nm for detecting the changes in the optical properties of multilayer light scattering medium in connection with the problem of the glucose level detection in the human tissue is discussed. Pulses scattered from a three-layer biotissue phantom consisting of two skin layers and a blood layer between them, are calculated with the help of a program code based on the Monte Carlo algorithm for different glucose concentrations. Relative changes in the recorded signals caused by variations in the glucose content are analysed for different source - detector separations. It is shown that the maximum relative change in the total pulse energy is 7.2% and 4.8% for the anisotropy factor of the layer mimicking skin g = 0.9 and 0.7, respectively, and the change in the glucose concentration from 0 up to 500 mg dL-1. The use of time gating leads to the increase in these values up to 12% and 8.5%, respectively. The sensitivity maps are obtained which can be used to determine the optimal duration and the time delay of the time gate relative to the probe pulse for five values of the source - detector separations. (biophotonics)

  17. New agents for probing glucose turnover and receptor densities in the brain

    International Nuclear Information System (INIS)

    New radiopharmaceuticals are developed to enter the brain by the application of metabolic tracers or analogs labelled with short-lived radionuclides. These radionuclides are used in conjunction with emission tomography for regional functional imaging of the brain. This article is restricted to D-glucose and its analogs and receptor-specific radiopharmaceuticals. (Auth.)

  18. Towards Analog Reverse Time Computation

    OpenAIRE

    Habibi, O.; Patihnedj, U. R.; Dhar, M. O.

    2006-01-01

    We report the consequences of a destabilization process on a simulated General Purpose Analog Computer. This new technology overcomes problems linked with serial ambiguity, and provides an analog bias to encode algorithms whose complexity is over polynomial. We also implicitly demonstrate how countermesures of the Stochastic Aperture Degeneracy could efficiently reach higher computational classes, and would open a road towards Analog Reverse Time Computation.

  19. Interaction of ZnS nanoparticles with flavins and glucose oxidase: A fluorimetric investigation

    International Nuclear Information System (INIS)

    Interactions of luminescence, water soluble ZnS nanoparticles (NPs) with flavins and glucose oxidase have been thoroughly investigated through optical spectroscopy. The photoluminescence of ZnS nanoparticles was quenched severely (?60%) by riboflavin while other flavins such as flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) show quenching to different extents under analogous conditions. However, interestingly no effect in luminescence intensity of ZnS NPs was observed with protein bound flavins such as in glucose oxidase. Fluorescence lifetime measurement confirmed the quenching to be static in nature. Scavenging of photo-generated electron of ZnS nanoparticles by the flavin molecules may be attributed to the decrease in luminescence intensity. Quenching of ZnS nanoparticles with flavins follows the linear Stern–Volmer plot. The Stern–Volmer constants decreased in the following order: KS?V (Riboflavin)> KS?V (FAD)> KS?V (FMN). This interaction study could generate useful protocol for the fluorimetric determination of riboflavin (vitamin B2) content and also riboflavin status in biological systems. - Highlights: ? Unique interaction specificity of ZnS nanoparticles with flavins has been explored. ? Unlike protein-bound flavin, fluorescence of free flavins was quenched by ZnS nanoparticles. ? FMN and FAD show quenching to different extents under analogous conditions. ? Fluorescence lifetime measurement confirmed the quenching to be static in nature. ? This study is useful for probing riboflavin in biological systems.

  20. 2-Deoxy-2-fluoro-d-glucose metabolism in Arabidopsis thaliana

    OpenAIRE

    Fatangare, Amol; Paetz, Christian; Saluz, Hanspeter; Svatoš, Aleš

    2015-01-01

    2-Deoxy-2-fluoro-d-glucose (FDG) is glucose analog routinely used in clinical and animal radiotracer studies to trace glucose uptake but it has rarely been used in plants. Previous studies analyzed FDG translocation and distribution pattern in plants and proposed that FDG could be used as a tracer for photoassimilates in plants. Elucidating FDG metabolism in plants is a crucial aspect for establishing its application as a radiotracer in plant imaging. Here, we describe the metabolic fate of F...

  1. Insulin-like growth factor-I correlates more closely than growth hormone with insulin resistance and glucose intolerance in patients with acromegaly.

    Science.gov (United States)

    Niculescu, Dan; Purice, Mariana; Coculescu, Mihail

    2013-06-01

    In normal subjects growth hormone (GH) and insulin-like growth factor-I (IGF-I) have opposing effects on glucose metabolism. Active acromegaly is associated with insulin resistance (IR) and glucose intolerance although both GH and IGF-I are elevated. Our objective was to compare whether GH or IGF-I correlates more closely with IR and glucose intolerance in acromegaly. Basal serum IGF-I and GH, glucose and insulin during an oral glucose tolerance test were measured in 70 normoglycemic and 44 hyperglycemic acromegalic patients (21 impaired fasting glucose, 11 impaired glucose tolerance and 12 diabetes mellitus) according to American Diabetes Association criteria. 55 patients were assessed before any treatment for acromegaly and 59 after surgery and/or radiotherapy (15 patients had normal IGF-I after treatment). Patients treated with somatostatin analogs, GH-receptor antagonists or antidiabetic drugs were excluded. IR was assessed by various basal and stimulated indices. Homeostatic Model Assessment 2-Insulin Resistance (HOMA2-IR) index correlated more closely with IGF-I (r = 0.65, p HOMA2-IR correlated better with IGF-I than nadir or random GH also in normoglycemic (n = 70; r = 0.74, p < 0.0001 vs. r = 0.36, p = 0.001 vs. r = 0.39, p < 0.001) and hyperglycemic patients (n = 44; r = 0.54, p = 0.0002 vs. r = 0.09, p = 0.4 vs. r = 0.14, p = 0.26). In multivariate logistic regression analysis IGF-I but not GH was a significant risk factor for glucose intolerance after adjusting for age, sex, weight and acromegaly duration (OR = 1.56, p = 0.01). In acromegaly IGF-I correlates more closely than GH with IR. IGF-I levels but not GH are associated with glucose intolerance. PMID:22562529

  2. Blood Glucose Levels

    Directory of Open Access Journals (Sweden)

    Carlos Estela

    2011-01-01

    Full Text Available The purpose of this study was to establish a mathematical model which can be used to estimate glucose levels in the blood over time. The equations governing this process were manipulated with the use of techniques such as separation of variables and integration of first order differential equations, which resulted in a function that described the glucose concentration in terms of time. This function was then plotted, which allowed us to find when glucose concentration was at its highest. The model was then used to analyze two cases where the maximum glucose level could not exceed a certain level while the amount of carbohydrates and glycemic index were varied, independently.

  3. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Nephropathy) Gastroparesis Mental Health Step On Up Treatment & Care Blood Glucose Testing Medication Doctors, Nurses & More Oral Health & Hygiene Women A1C Insulin Pregnancy ...

  4. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Complications Neuropathy Foot Complications DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Treatment & Care Blood Glucose Testing Medication Doctors, Nurses & ...

  5. The Young Solar Analogs Project

    Science.gov (United States)

    Gray, Richard O.; Saken, J. M.; Corbally, C. J.; Fuller, V.; Kahvaz, Y.; Lambert, R.; Newsome, I.; Seeds, M.

    2013-01-01

    We are carrying out a long-term project of measuring chromospheric activity and brightness variations in 31 young solar analogs (YSAs) using facilities at the Dark Sky Observatory (DSO - Appalachian State University) and the Vatican Advanced Technology Telescope (VATT). These YSAs are solar-type (spectral types F8 - K2) stars with ages ranging from 0.3 - 1.5 Gyr. The goal of this project is to gain better understanding of the magnetic activity of the early Sun, and especially how that activity may have impacted the development of life on the Earth. This project will also yield insights into the space environments experienced by young Earth analogs. We are currently in the 6th year of spectroscopic measurements of these stars: these data include Ca II H & K chromospheric flux measurements, and narrow-band measurements in the photospheric G-band, both obtained with the G/M spectrograph on the DSO 32-inch telescope. We will present evidence of activity cycles in a number of our stars, as well as periods determined from rotational modulation of the spectroscopic indices. The relationship between the Ca II activity index and the G-band index will be explored. NSF support for our project has provided funds for the construction of a robotic photometric telescope to monitor the program stars in a 5-passband system (Strömgren-v, Johnson-Cousins B, V, and R, and a 3-nm wide H? filter). The robotic telescope has been functional since April 2012 and observes the program stars on every clear night; combined with the Piggy-back telescope attached to the DSO 32-inch, we now have photometric observations on over 130 nights stretching over nearly 2 years. We will examine the relationships between variations in the Ca II H & K index, the G-band index and the photometric bands. This project is supported by the National Science Foundation, grant AST-1109158.

  6. Kidney transplantation improves arterial function measured by pulse wave analysis and endothelium-independent dilatation in uraemic patients despite deterioration of glucose metabolism

    DEFF Research Database (Denmark)

    Hornum, Mads; Clausen, Peter

    2011-01-01

    BACKGROUND: The aim of this study is to investigate the effect of kidney transplantation on arterial function in relation to changes in glucose metabolism. METHODS: Included were 40 kidney recipients (Tx group, age 38 ± 13 years) and 40 patients without known diabetes remaining on the waiting list for kidney transplantation (uraemic control group, age 47 ± 11 years). Arterial function was estimated by the pulse wave velocity (PWV) of the carotid-femoral pulse wave, aortic augmentation index (AIX), flow-mediated (FMD) and nitroglycerin-induced vasodilatation (NID) of the brachial artery performed before transplantation and after 12 months. PWV recorded sequentially at the carotid and femoral artery is an estimate of arterial stiffness; AIX is an integrated index of vascular and ventricular function. FMD and NID are the dilatory capacities of the brachial artery after increased flow (endothelium dependent) and after nitroglycerin administration (endothelium independent). The insulin resistance was estimated by the insulin sensitivity index (ISI). RESULTS: AIX was reduced from 27% (17-33) to 14% (7-25) (P = 0.01) after 1 year in the Tx group and remained stable in uraemic controls (P = 0.001, between groups), and NID increased from 11% (7-16) to 18% (12-23) (P = 0.0005). At baseline, carotid-femoral PWV was similar in the Tx group, uraemic controls and healthy controls and it did not change significantly after transplantation. ISI deteriorated in the Tx group from 7.2 ± 4.0 to 5.0 ± 3.0 (P = 0.005) and remained stable in uraemic controls (7.9 ± 5.1 vs 8.5 ± 4.9, NS). Mean arterial blood pressure decreased from 105 ± 13 to 96 ± 11 mmHg (P = 0.005) in the Tx group despite a 20% lower use of antihypertensive agents. CONCLUSIONS: Arterial function measured by AIX and NID was improved 1 year after kidney transplantation. This was associated with a decline in blood pressure and seen inspite of an increase in insulin resistance.

  7. Glucose Recognition in Vitro Using Fluorescent Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Noronha, G; Heiss, A M; Reilly, J R; Vachon, Jr, D J; Cary, D R; Zaitseva, N P; Reibold, R A; Lane, S M; Peyser, T A; Satcher, J H

    2001-04-25

    Diabetes is a disease that affects over 16 million people in the USA at a cost of 100 billion dollars annually. The ability to regulate insulin delivery in people with Type 1 diabetes is imperative as is the need to manage glucose levels in all people with this disease. Our current method for monitoring glucose is a (FDA approved) minimally invasive enzymatic sensor that can measure glucose levels in vivo for three days. We are focused on developing a noninvasive implantable glucose sensor that will be interrogated by an external device. The material must be robust, easy to process, biocompatible and resistant to biofouling. In this Presentation we will discuss the development of a new polymeric matrix that can recognize physiological levels of glucose in vitro using fluorescent spectroscopy.

  8. The glucose oxidase-peroxidase assay for glucose

    Science.gov (United States)

    The glucose oxidase-peroxidase assay for glucose has served as a very specific, sensitive, and repeatable assay for detection of glucose in biological samples. It has been used successfully for analysis of glucose in samples from blood and urine, to analysis of glucose released from starch or glycog...

  9. Genetic variation in GIPR influences the glucose and insulin responses to an oral glucose challenge

    DEFF Research Database (Denmark)

    Saxena, Richa; Hivert, Marie-France; Langenberg, Claudia; Tanaka, Toshiko; Pankow, James S; Vollenweider, Peter; Lyssenko, Valeriya; Bouatia-Naji, Nabila; Dupuis, Josée; Jackson, Anne U; Kao, W H Linda; Li, Man; Glazer, Nicole L; Manning, Alisa K; Luan, Jian'an; Stringham, Heather M; Prokopenko, Inga; Johnson, Toby; Grarup, Niels; Boesgaard, Trine W; Lecoeur, Cécile; Shrader, Peter; O'Connell, Jeffrey; Ingelsson, Erik; Couper, David J; Rice, Kenneth; Song, Kijoung; Andreasen, Camilla H; Dina, Christian; Köttgen, Anna; Le Bacquer, Olivier; Pattou, François; Taneera, Jalal; Steinthorsdottir, Valgerdur; Rybin, Denis; Ardlie, Kristin; Sampson, Michael; Qi, Lu; van Hoek, Mandy; Weedon, Michael N; Aulchenko, Yurii S; Voight, Benjamin F; Grallert, Harald; Balkau, Beverley; Bergman, Richard N; Bielinski, Suzette J; Bonnefond, Amelie; Bonnycastle, Lori L; Borch-Johnsen, Knut; Böttcher, Yvonne; Brunner, Eric; Buchanan, Thomas A; Bumpstead, Suzannah J; Cavalcanti-Proença, Christine; Charpentier, Guillaume; Chen, Yii-Der Ida; Chines, Peter S; Collins, Francis S; Cornelis, Marilyn; J Crawford, Gabriel; Delplanque, Jerome; Doney, Alex; Egan, Josephine M; Erdos, Michael R; Firmann, Mathieu; Forouhi, Nita G; Fox, Caroline S; Goodarzi, Mark O; Graessler, Jürgen; Hingorani, Aroon; Isomaa, Bo; Jørgensen, Torben; Kivimaki, Mika; Kovacs, Peter; Krohn, Knut; Kumari, Meena; Lauritzen, Torsten; Lévy-Marchal, Claire; Mayor, Vladimir; McAteer, Jarred B; Meyre, David; Mitchell, Braxton D; Mohlke, Karen L; Morken, Mario A; Narisu, Narisu; Palmer, Colin N A; Pakyz, Ruth; Pascoe, Laura; Payne, Felicity; Pearson, Daniel; Rathmann, Wolfgang; Sandbaek, Annelli; Sayer, Avan Aihie; Scott, Laura J; Sharp, Stephen J; Sijbrands, Eric; Singleton, Andrew; Siscovick, David S; Smith, Nicholas L; Sparsø, Thomas; Swift, Amy J; Syddall, Holly; Thorleifsson, Gudmar; Tönjes, Anke; Tuomi, Tiinamaija; Tuomilehto, Jaakko; Valle, Timo T; Waeber, Gérard; Walley, Andrew; Waterworth, Dawn M; Zeggini, Eleftheria; Zhao, Jing Hua; Illig, Thomas; Wichmann, H Erich; Wilson, James F; van Duijn, Cornelia; Hu, Frank B; Morris, Andrew D; Frayling, Timothy M; Hattersley, Andrew T; Thorsteinsdottir, Unnur; Stefansson, Kari; Nilsson, Peter; Syvänen, Ann-Christine; Shuldiner, Alan R; Walker, Mark; Bornstein, Stefan R; Schwarz, Peter; Williams, Gordon H; Nathan, David M; Kuusisto, Johanna; Laakso, Markku; Cooper, Cyrus; Marmot, Michael; Ferrucci, Luigi; Mooser, Vincent; Stumvoll, Michael; Loos, Ruth J F; Altshuler, David; Psaty, Bruce M; Rotter, Jerome I; Boerwinkle, Eric; Hansen, Torben; Pedersen, Oluf; Florez, Jose C; McCarthy, Mark I; Boehnke, Michael; Barroso, Inês; Sladek, Robert; Froguel, Philippe; Meigs, James B; Groop, Leif; Wareham, Nicholas J; Watanabe, Richard M

    2010-01-01

    Glucose levels 2 h after an oral glucose challenge are a clinical measure of glucose tolerance used in the diagnosis of type 2 diabetes. We report a meta-analysis of nine genome-wide association studies (n = 15,234 nondiabetic individuals) and a follow-up of 29 independent loci (n = 6,958-30,620). We identify variants at the GIPR locus associated with 2-h glucose level (rs10423928, beta (s.e.m.) = 0.09 (0.01) mmol/l per A allele, P = 2.0 x 10(-15)). The GIPR A-allele carriers also showed decreas...

  10. ESD analog circuits and design

    CERN Document Server

    Voldman, Steven H

    2014-01-01

    A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

  11. Exenatide Regulates Cerebral Glucose Metabolism in Brain Areas Associated With Glucose Homeostasis and Reward System.

    Science.gov (United States)

    Daniele, Giuseppe; Iozzo, Patricia; Molina-Carrion, Marjorie; Lancaster, Jack; Ciociaro, Demetrio; Cersosimo, Eugenio; Tripathy, Devjit; Triplitt, Curtis; Fox, Peter; Musi, Nicolas; DeFronzo, Ralph; Gastaldelli, Amalia

    2015-10-01

    Glucagon-like peptide 1 receptors (GLP-1Rs) have been found in the brain, but whether GLP-1R agonists (GLP-1RAs) influence brain glucose metabolism is currently unknown. The study aim was to evaluate the effects of a single injection of the GLP-1RA exenatide on cerebral and peripheral glucose metabolism in response to a glucose load. In 15 male subjects with HbA1c of 5.7 ± 0.1%, fasting glucose of 114 ± 3 mg/dL, and 2-h glucose of 177 ± 11 mg/dL, exenatide (5 ?g) or placebo was injected in double-blind, randomized fashion subcutaneously 30 min before an oral glucose tolerance test (OGTT). The cerebral glucose metabolic rate (CMRglu) was measured by positron emission tomography after an injection of [(18)F]2-fluoro-2-deoxy-d-glucose before the OGTT, and the rate of glucose absorption (RaO) and disposal was assessed using stable isotope tracers. Exenatide reduced RaO0-60 min (4.6 ± 1.4 vs. 13.1 ± 1.7 ?mol/min ? kg) and decreased the rise in mean glucose0-60 min (107 ± 6 vs. 138 ± 8 mg/dL) and insulin0-60 min (17.3 ± 3.1 vs. 24.7 ± 3.8 mU/L). Exenatide increased CMRglu in areas of the brain related to glucose homeostasis, appetite, and food reward, despite lower plasma insulin concentrations, but reduced glucose uptake in the hypothalamus. Decreased RaO0-60 min after exenatide was inversely correlated to CMRglu. In conclusion, these results demonstrate, for the first time in man, a major effect of a GLP-1RA on regulation of brain glucose metabolism in the absorptive state. PMID:26116695

  12. Deuterated prostaglandin analogs

    International Nuclear Information System (INIS)

    The preparation of deuterated prostaglandin analogs which are superior to the natural compounds regarding their pharmacological activity is described. They can be used as antihypertensive, antihtrombogenic and antifertile agent, furthermore as antineoplastic agent, bronchodilators or bronchoconstricters. Besides the type of compound, 9?, 13?-bisdeuterio-9?, 11?, 15?-trihydroxy-13-trans-prostenic acid, 9?, 13?-bisdeuterio-9?, 11?, 15?-trihydroxy-5-cis, 13-trans-prostadiene acid and 15?-deuterio-9?, 11?, 13?-trihydroxy-5 cis-13-trans-prostadiene acid are claimed, i.e. the preparation of each compound. Prescriptions for pharmaceutic preparations are described. (UWI)

  13. Discrete Calculus by Analogy

    CERN Document Server

    Izadi, F A; Bagirov, G

    2009-01-01

    With its origins stretching back several centuries, discrete calculus is now an increasingly central methodology for many problems related to discrete systems and algorithms. The topics covered here usually arise in many branches of science and technology, especially in discrete mathematics, numerical analysis, statistics and probability theory as well as in electrical engineering, but our viewpoint here is that these topics belong to a much more general realm of mathematics; namely calculus and differential equations because of the remarkable analogy of the subject to this branch of mathemati

  14. Construction of a Glucose Biosensor by Immobilizing Glucose Oxidase within a Poly(o-phenylenediamine) Covered Screen-printed Electrode

    OpenAIRE

    Miao Yuqing; Chen Jianrong; Wu Xiaohua

    2006-01-01

    The glucose biosensors were prepared by the electropolymerization of the non-conductive polymer, Poly(o-phenylenediamine), onto a planar screen-printed electrode. A fabrication procedure was performed to decrease the waste of expensive enzyme. The amperometric glucose response was measured by the potensiostating of the prepared glucose biosensors at a potential of 0.3 V with ferrocene as mediator. Results show that the obtained biosensors have a linear range up to 25 mM glucose, fast response...

  15. Wireless glucose monitoring watch enabled by an implantable self-sustaining glucose sensor system

    Science.gov (United States)

    Rai, Pratyush; Varadan, Vijay K.

    2012-10-01

    Implantable glucose sensors can measure real time blood glucose as compared to conventional techniques involving drawing blood samples and in-vitro processing. An implantable sensor requires energy source for operation with wire inout provision for power and sending signals. Implants capable of generation-transmission of sensory signals, with minimal or no power requirement, can solve this problem. An implantable nanosensor design has been presented here, which can passively detect glucose concentration in blood stream and transmit data to a wearable receiver-recorder system or a watch. The glucose sensitive component is a redox pair of electrodes that generates voltage proportional to glucose concentration. The bio-electrode, made of carbon nanotubes-enzyme nanocluster, has been investigated because of the large surface area for taping electrical signals. This glucose sensor can charge a capacitor, which can be a part of a LCR resonance/inductive coupling based radio frequency (RF) sensor telemetry. Such a system can measure change in glucose concentration by the induced frequency shift in the LCR circuit. A simultaneous power transmission and signal transmission can be achieved by employing two separate LCR oscillating loops, one for each operation. The corresponding coupling LCR circuits can be housed in the wearable receiving watch unit. The data logged in this glucose monitoring watch can be instrumental in managing blood glucose as trigger for an insulin dispensing payload worn on person or implanted.

  16. Analog-microchip for ALICE TRD

    International Nuclear Information System (INIS)

    For the ALICE Transition Radiation Detector (TRD) a first version of an analog chip was implemented and tested. It consists of a number of analog channels, and is the first block of the front end electronics receiving the signals from the detector pads. The current signals of the detector pads are first amplified by a charge-sensitive preamplifier. It is followed by a pole-zero cancellation circuit and a second order shaper-filter ensuring a shaped output pulse with about 125 ns FWHM. The last functional element of the analog channel chain is the output amplifier. It delivers an output signal according to the ADC requirements concerning driving capability and output levels. The overall gain of the analog channel is 5.2 mV/fC and the shaping type is CR-(RC)2. The output amplifier acts an external 8-bit 2 V range fast ADC (National type NS 08351). In the first version of the TRD analog chip 21-analog channels, basically the same, were provided. The only difference refers to the value of input pad resistance. There are 8 channels with 0 ohms, 8 channels with 50 ohms, 2 channels with 200 ohms and 2 channels with 500 ohms, to estimate the influence of the pad input resistance to overall noise. One additional channel with 50 ohms input resistance (probe channel) allows monitoring the signal in each main parts of the analog channel, not only to the output. The first results obtained from the measurements of the analog channels of the chip are very similar with those from simulation. The mains results are given in a table containing the Gain, Shaping Type, Input dynamic range, Equivalent input noise, Output pulse level, Integral nonlinearity and Max. power consumption/ch. The signals in the probe channel, corresponding to preamplifier, pole- zero circuit, shaper and output amplifier are shown. The first version of the analog chip for ALICE TRD was built and tested. The results fulfil the initial requirements. At present the chips of this first versions are used in the multichip module card (MMC), containing ADCs and a digital chip, which is the whole configuration of the front end electronics. Very soon the 2nd version of the analog chip will be submitted. For this the shaping type is CR-(RC)4, the estimated equivalent of 700 e, the input dynamic range of 165 fC, the gain of about 6.1 mV/fC, and the output of differential type. (authors)

  17. Albert Einstein, Analogizer Extraordinaire

    CERN Document Server

    CERN. Geneva

    2007-01-01

    Where does deep insight in physics come from? It is tempting to think that it comes from the purest and most precise of reasoning, following ironclad laws of thought that compel the clear mind completely rigidly. And yet the truth is quite otherwise. One finds, when one looks closely at any major discovery, that the greatest of physicists are, in some sense, the most crazily daring and irrational of all physicists. Albert Einstein exemplifies this thesis in spades. In this talk I will describe the key role, throughout Albert Einstein's fabulously creative life, played by wild guesses made by analogy lacking any basis whatsoever in pure reasoning. In particular, in this year of 2007, the centenary of 1907, I will describe how over the course of two years (1905 through 1907) of pondering, Einstein slowly came, via analogy, to understand the full, radical consequences of the equation that he had first discovered and published in 1905, arguably the most famous equation of all time: E = mc2.

  18. Measurement of myocardial glucose uptake in patients with ischemic cardiomyopathy: application of a new quantitative method using regional tracer kinetic information

    DEFF Research Database (Denmark)

    Wiggers, H; Bøttcher, M; Nielsen, Torsten Toftegård; Gjedde, A; Bøtker, H E

    1999-01-01

    Quantification of myocardial glucose uptake (MGU) by 18F-fluoro-2-deoxyglucose (FDG) using PET may be inaccurate, because the correction factor that relates myocardial FDG uptake to MGU, the lumped constant (LC), is not a true constant. Recent studies have shown that analysis of FDG time-activity curves allows determination of individual LCs and that variable LCs yield accurate determination of MGU. We compared the magnitude of the LC in different regions of the heart in patients with ischemic c...

  19. Detecting early kidney damage in horses with colic by measuring matrix metalloproteinase -9 and -2, other enzymes, urinary glucose and total proteins

    OpenAIRE

    Salonen Hanna; Kastevaara Tuulia; Holopainen Elina; Rajamäki Minna; Raekallio Marja; Arosalo Bela M; Sankari Satu

    2007-01-01

    Abstract Background The aim of the study was to investigate urine matrix metalloproteinase (MMP-2 and -9) activity, alkaline phosphatase/creatinine (U-AP/Cr) and gamma-glutamyl-transpeptidase/creatinine (U-GGT/Cr) ratios, glucose concentration, and urine protein/creatinine (U-Prot/Cr) ratio and to compare data with plasma MMP-2 and -9 activity, cystatin-C and creatinine concentrations in colic horses and healthy controls. Horses with surgical colic (n = 5) were compared to healthy stallions (...

  20. Epigenome-Wide Association Study of Fasting Measures of Glucose, Insulin, and HOMA-IR in the Genetics of Lipid Lowering Drugs and Diet Network Study

    OpenAIRE

    Hidalgo, Bertha; Irvin, M. Ryan; Sha, Jin; Zhi, Degui; Aslibekyan, Stella; Absher, Devin; Tiwari, Hemant K.; Kabagambe, Edmond K.; Ordovas, Jose M; Arnett, Donna K

    2014-01-01

    Known genetic susceptibility loci for type 2 diabetes (T2D) explain only a small proportion of heritable T2D risk. We hypothesize that DNA methylation patterns may contribute to variation in diabetes-related risk factors, and this epigenetic variation across the genome can contribute to the missing heritability in T2D and related metabolic traits. We conducted an epigenome-wide association study for fasting glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) amo...

  1. Continuous glucose monitoring

    DEFF Research Database (Denmark)

    Klonoff, David C; Buckingham, Bruce; Christiansen, Jens S; Montori, Victor M; Tamborlane, William V; Vigersky, Robert A; Wolpert, Howard

    2011-01-01

    The aim was to formulate practice guidelines for determining settings where patients are most likely to benefit from the use of continuous glucose monitoring (CGM).......The aim was to formulate practice guidelines for determining settings where patients are most likely to benefit from the use of continuous glucose monitoring (CGM)....

  2. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... by Mail Close www.diabetes.org > Living With Diabetes > Treatment and Care > Blood Glucose Testing Share: Print Page Text Size: A A ... Frequent urination Increased thirst Part of managing your diabetes is checking your blood glucose often. Ask your doctor how often you should ...

  3. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... by Mail Close www.diabetes.org > Living With Diabetes > Treatment and Care > Blood Glucose Testing Share: Print Page ... and-how-tos, In this section Living With Diabetes Treatment and Care Blood Glucose Testing Checking Your Blood ...

  4. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Lower Your Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To Know Your ... as a cold or flu. You have other stress, such as family conflicts or school or ... following: High blood glucose High levels of sugar in the urine ...

  5. Brain Glucose Metabolism Controls Hepatic Glucose and Lipid Production

    OpenAIRE

    Lam, Tony K. T.

    2007-01-01

    Brain glucose-sensing mechanisms are implicated in the regulation of feeding behavior and hypoglycemic-induced hormonal counter-regulation. This commentary discusses recent findings indicating that the brain senses glucose to regulate both hepatic glucose and lipid production.

  6. HAPS, a Handy Analog Programming System

    DEFF Research Database (Denmark)

    Højberg, Kristian Søe

    1975-01-01

    HAPS (Hybrid Analog Programming System) is an analog compiler that can be run on a minicomputer in an interactive mode. Essentially HAPS is written in FORTRAN. The equations to be programmed for an ana log computer are read in by using a FORTRAN-like notation. The input must contain maximum and minimum values for the variables. The output file includes potentiometer coefficients and static-test 'measuring values.' The file format is fitted to an automatic potentiometer-setting and static-test pr...

  7. PACS with analog (video) inputs

    International Nuclear Information System (INIS)

    Until ACR-NEMA standards are widely accepted, picture achieving and communications system (PACS) must use analog (video) input of image data from Mr and CT scanners. This paper investigates the dynamic range of data so stored and acquired, compared with conventional film. Representative MR and CT images of the brain and body were transferred by video signal both to a prototype PACS system (CommView, AT and T) and to a laser imager (3M). Quantitative measurement of output optical density versus original video input for the two systems were compared. For average widow and level settings, images from the laser imager possessed a greater dynamic range (gamma characteristic) that those from the PACS system

  8. Electronic devices for analog signal processing

    CERN Document Server

    Rybin, Yu K

    2012-01-01

    Electronic Devices for Analog Signal Processing is intended for engineers and post graduates and considers electronic devices applied to process analog signals in instrument making, automation, measurements, and other branches of technology. They perform various transformations of electrical signals: scaling, integration, logarithming, etc. The need in their deeper study is caused, on the one hand, by the extension of the forms of the input signal and increasing accuracy and performance of such devices, and on the other hand, new devices constantly emerge and are already widely used in practice, but no information about them are written in books on electronics. The basic approach of presenting the material in Electronic Devices for Analog Signal Processing can be formulated as follows: the study with help from self-education. While divided into seven chapters, each chapter contains theoretical material, examples of practical problems, questions and tests. The most difficult questions are marked by a diamon...

  9. The Effect of Basal Analog Insulin on the Glycemic Variability in Type 2 Diabetics

    Directory of Open Access Journals (Sweden)

    Soner Cander

    2014-06-01

    Full Text Available Purpose: The aim of this study was to investigate the effect of insulin detemir and glargine on glycemic variability as determined by capillary blood glucose measurements in Type 2 diabetics treated with oral antidiabetic drugs. Material and Method: A total of 64 insulin-naive type 2 diabetics with a HbA1c level of 7.5%-10% were included in the study. The patients were randomized into 3 groups according to the basal insulin analog started; Group 1 (n=22 was started on once-daily detemir, Group 2 (n=22 twice-daily detemir, and Group 3 (n=20 insulin glargine. Basal insulin doses were titrated according to the morning/evening fasting capillary blood glucose levels. Standard deviations of the 8-point intraday fasting and postprandial blood glucose values were compared. Results: The fasting blood glucose intraday standard deviation values showed an improvement of 22.4% in Group 1, 21.4% in Group 2, and 26.4% in Group 3, while the intraday standard deviation for the postprandial values showed an improvement of 14.4%, 15.2%, and 38.7%, respectively (p>0.05. The standard deviation values did not show statistical significance when the groups were compared with each other. Baseline HbA1c values and insulin doses negatively correlated with the glycemic variability. Dicussion: Basal insulin added to treatment in Type 2 diabetics provided an improvement of 14.4% to 38.7% in glycemic variability. There was no significant difference between insulin glargine and detemir regarding this effect. Turk Jem 2014; 2: 33-38

  10. Titanium-Beta Zeolites Catalyze the Stereospecific Isomerization of D-Glucose to L-Sorbose via Intramolecular C5-C1 Hydride Shift

    Energy Technology Data Exchange (ETDEWEB)

    Gounder, Rajamani [California Inst. of Technology (CalTech), Pasadena, CA (United States); Davis, Mark E. [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2013-06-03

    Pure-silica zeolite beta containing Lewis acidic framework Ti4+ centers (Ti-Beta) is shown to catalyze the isomerization of D-glucose to L-sorbose via an intramolecular C5–C1 hydride shift. Glucose–sorbose isomerization occurs in parallel to glucose–fructose isomerization on Ti-Beta in both water and methanol solvents, with fructose formed as the predominant product in water and sorbose as the predominant product in methanol (at 373 K) at initial times and over the course of >10 turnovers. Isotopic tracer studies demonstrate that 13C and D labels placed respectively at the C1 and C2 positions of glucose are retained respectively at the C6 and C5 positions of sorbose, consistent with its formation via an intramolecular C5–C1 hydride shift isomerization mechanism. This direct Lewis acid-mediated pathway for glucose–sorbose isomerization appears to be unprecedented among heterogeneous or biological catalysts and sharply contrasts indirect base-mediated glucose–sorbose isomerization via 3,4-enediol intermediates or via retro-aldol fragmentation and recombination of sugar fragments. Measured first-order glucose–sorbose isomerization rate constants (per total Ti; 373 K) for Ti-Beta in methanol are similar for glucose and glucose deuterated at the C2 position (within a factor of ~1.1), but are a factor of ~2.3 lower for glucose deuterated at each carbon position, leading to H/D kinetic isotope effects expected for kinetically relevant intramolecular C5–C1 hydride shift steps. Optical rotation measurements show that isomerization of D-(+)-glucose (92% enantiomeric purity) with Ti-Beta in water (373 K) led to the formation of L-(-)-sorbose (73% enantiomeric purity) and D-(-)-fructose (87% enantiomeric purity) as the predominant stereoisomers, indicating that stereochemistry is preserved at carbon centers not directly involved in intramolecular C5–C1 or C2–C1 hydride shift steps, respectively. This new Lewis acid-mediated rearrangement of glucose to sorbose does not appear to have a metalloenzyme analog.

  11. Glucose cycling is markedly enhanced in pancreatic islets of obese hyperglycemic mice

    International Nuclear Information System (INIS)

    Pancreatic islets from fed 7-month old lean and obese hyperglycemic mice (ob/ob) were incubated with 3H2O and 5.5 mM or 16.7 mM glucose. Incorporation of 3H into the medium glucose was taken as the measure of glucose-6-P hydrolysis to glucose. Glucose utilization was measured from the yield of 3H2O from [5-3H]glucose. Only 3-4% of the glucose phosphorylated was dephosphorylated by the lean mouse islets irrespective of the glucose concentration. In contrast, the ob/ob mouse islets at 5.5 mM glucose dephosphorylated 18% of the glucose phosphorylated and 30% at 16.7 mM. Thus, the islets of hyperglycemic mice demonstrate increased glucose cycling as compared to the islets of normoglycemic lean mice

  12. Feedback in analog circuits

    CERN Document Server

    Ochoa, Agustin

    2016-01-01

    This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...

  13. Pre-meal video game playing and a glucose preload suppress food intake in normal weight boys.

    Science.gov (United States)

    Branton, Alyson; Akhavan, Tina; Gladanac, Branka; Pollard, Damion; Welch, Jo; Rossiter, Melissa; Bellissimo, Nick

    2014-12-01

    Increased food intake (FI) during television viewing has been reported in children, but it is unknown if this occurs following pre-meal video game playing (VGP). The objective was to determine the effect of pre-meal VGP for 30?min on subjective appetite and emotions, and FI in normal weight (NW) boys after a glucose or control preload. On four test mornings, NW boys (n?=?19) received equally sweetened preloads of a non-caloric sucralose control or 50?g glucose in 250?mL of water, with or without VGP for 30?min. Food intake from an ad libitum pizza meal was measured immediately after. Subjective appetite was measured at 0, 15, 30, and 60?min. Subjective emotions were determined by visual analog scale at baseline and immediately before lunch. Both VGP (p?=?0.023) and glucose (p?<0.001) suppressed FI. Pre-meal VGP compared with no-VGP, and glucose compared with the non-caloric control, decreased FI by 59 and 170?kcal, respectively. Subjective average appetite increased to 30?min (p?=?0.003), but was lower after glucose (p?=?0.01) in both the VGP and no-VGP conditions compared with the control. Frustration and aggression scores increased after VGP (p?<0.05), but did not correlate with FI. However, baseline and pre-meal happiness and excitement scores were inversely associated with FI. In conclusion, both pre-meal VGP and the glucose preload suppressed FI, supporting the roles of both physiologic and environmental factors in the regulation of short-term FI in 9- to 14-year-old NW boys. PMID:25150911

  14. Methodologic Considerations for Quantitative 18F-FDG PET/CT Studies of Hepatic Glucose Metabolism in Healthy Subjects

    DEFF Research Database (Denmark)

    Trägårdh, Malene; MØller, Niels

    2015-01-01

    UNLABELLED: PET with the glucose analog (18)F-FDG is used to measure regional tissue metabolism of glucose. However, (18)F-FDG may have affinities different from those of glucose for plasma membrane transporters and intracellular enzymes; the lumped constant (LC) can be used to correct these differences kinetically. The aims of this study were to investigate the feasibility of measuring human hepatic glucose metabolism with dynamic (18)F-FDG PET/CT and to determine an operational LC for (18)F-FDG by comparison with (3)H-glucose measurements. METHODS: Eight healthy human subjects were included. In all studies, (18)F-FDG and (3)H-glucose were mixed in saline and coadministered. A 60-min dynamic PET recording of the liver was performed for 180 min with blood sampling from catheters in a hepatic vein and a radial artery (concentrations of (18)F-FDG and (3)H-glucose in blood). Hepatic blood flow was determined by indocyanine green infusion. First, 3 subjects underwent studies comparing bolus administration and constant-infusion administration of tracers during hyperinsulinemic-euglycemic clamping. Next, 5 subjects underwent studies comparing fasting and hyperinsulinemic-euglycemic clamping with tracer infusions. Splanchnic extraction fractions of (18)F-FDG (E*) and (3)H-glucose (E) were calculated from concentrations in blood, and the LC was calculated as ln(1 - E*)/ln(1 - E). Volumes of interest were drawn in the liver tissue, and hepatic metabolic clearance of (18)F-FDG (mL of blood/100 mL of liver tissue/min) was estimated. RESULTS: For bolus versus infusion, E* values were always negative when (18)F-FDG was administered as a bolus and were always positive when it was administered as an infusion. For fasting versus clamping, E* values were positive in 4 of 5 studies during fasting and were always positive during clamping. Negative extraction fractions were ascribed to the tracer distribution in the large volume of distribution in the prehepatic splanchnic bed. The LC ranged from 0.43 to 2.53, with no significant difference between fasting and clamping. CONCLUSION: The large volume of distribution of (18)F-FDG in the prehepatic splanchnic bed may complicate the analysis of dynamic PET data because it represents the mixed tracer input to the liver via the portal vein. Therefore, dynamic (18)F-FDG data for human hepatic glucose metabolism should be interpreted with caution, but constant tracer infusion seems to yield more robust results than bolus injection.

  15. Boron analogs of ?-amino acids

    International Nuclear Information System (INIS)

    The authors have been concerned with the synthesis, characterization, and definition of a class of novel isoelectronic and isostructural boron analogs of the ?-amino acids, glycine, alanine and betaine. This paper presents a brief review of the preparation and characterization of some of the first examples of the analogs and related compounds and describes their antitumor activity. The results of preliminary testing at Brookhaven as to the suitability of these analogs for use in BNCT are presented

  16. Beginning analog electronics through projects

    CERN Document Server

    Singmin, Andrew

    2001-01-01

    Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an

  17. ESD design for analog circuits

    CERN Document Server

    Vashchenko, Vladislav A

    2010-01-01

    This book is on high voltage and system level circuit design. It covers many challenging ESD topics related to analog circuit design for both ESD device and ESD circuits at the network level. Included is extensive discussion of analog design for DC-DC buck/boost converters, level shifters, digital-analog converters, high speed and precision power amplifiers, and system level cable specs for interface applications.

  18. On the role of glucose-dependent insulintropic polypeptide in postprandial metabolism in humans

    DEFF Research Database (Denmark)

    Asmar, Meena; Tangaa, Winnie

    2010-01-01

    We investigated the role of glucose-dependent insulintropic polypeptide (GIP) in the regulation of gastric emptying (GE), appetite, energy intake (EI), energy expenditure (EE), plasma levels of triglycerides (TAG), and free fatty acids (FFA) in humans. First, 20 healthy males received intravenous infusion of GIP (0.8 pmol.kg(-1).min(-1)) or saline for 300 min during and after a fixed meal (protocol 1). GE was measured using paracetamol, appetite sensations using visual analog scales, EE using indirect calorimetry, and EI during a subsequent ad libitum meal (at 300 min). Next, 10 healthy males received intravenous infusions of Intralipid, glucose, or Intralipid plus glucose, with and without GIP (1.5 pmol.kg(-1).min(-1)) for 300 min (protocol 2). In protocol 1, GIP did not have any effect on GE, EI, EE, removal of TAG, or FFA and did not influence the subjective feeling of hunger, satiety, fullness or prospective food consumption compared with saline. In protocol 2, no difference was seen in the plasma TAG on Intralipid + GIP/saline and Intralipid + glucose + GIP/saline days. FFA concentrations were lower on Intralipid + glucose + GIP/saline days (P <0.05) compared with Intralipid + GIP/saline days and on Intralipid + GIP day (P <0.004) compared with Intralipid + saline day. Insulin increased on all GIP days compared with saline days (P <0.05). In conclusion, while confirming its insulinotropic effects, these data suggest that GIP does not affect GE, appetite, energy intake, EE, or the clearance rate of the applied TAG formulation in humans. However, both insulin and GIP lower post-Intralipid FFA concentration, GIP probably via stimulation of insulin secretion, increasing FFA reesterification.

  19. MIMO detection in analog VLSI

    OpenAIRE

    Soler Garrido, J; Piechocki, RJ; McNamara, DP; Maharatna, K

    2006-01-01

    In this paper we propose an analog VLSI approach to maximum a posteriori (MAP) detection in multiple-input multiple-output (MIMO) systems. This detector can be seen as an extension of the well known analog decoding concept for error correcting codes, as it is constructed using similar building blocks. Therefore, it can naturally interact with analog decoders in order to perform turbo detection in MIMO systems. First transistor-level simulations for a small analog MIMO detector in a 0.25/spl m...

  20. Abnormal temporal lobe response in Alzheimer's disease during cognitive processing as measured by 11C-2-deoxy-D-glucose and PET

    International Nuclear Information System (INIS)

    Elderly controls and probable Alzheimer's disease patients underwent serial positron emission tomography (PET) studies during a baseline condition and while performing a verbal memory task. For the temporal lobes, all 7 Alzheimer patients demonstrated a relative shift in glucose metabolic rates to the right hemisphere during the memory condition relative to baseline, and 5 of 7 controls showed a shift to the left hemisphere. Baseline absolute regional metabolic rates replicate previous findings and were somewhat less useful than the memory challenge in differentiating patients from controls. These results indicate that a temporal lobe abnormality in Alzheimer's disease is related to memory performance

  1. Fluorescent Nano-Optodes for Glucose Detection

    OpenAIRE

    Billingsley, Kelvin; Balaconis, Mary K.; Dubach, J. Matthew; Zhang, Ning; Lim, Ed; Francis, Kevin P.; Clark, Heather A.

    2010-01-01

    We have designed fluorescent nanosensors based on ion-selective optodes capable of detecting small molecules. By localizing the sensor components in a hydrophobic core, these nanosensors are able to monitor dynamic changes in concentration of the model analyte, glucose. The nanosensors demonstrated this response in vitro and also when injected subcutaneously into mice. The response of the nanosensors tracked changes in blood glucose levels in vivo that were comparable to measurements taken us...

  2. lyoluminescence experiments on mannose and glucose

    International Nuclear Information System (INIS)

    As lyoluminescence seems to present interesting characteristics for several applications in dosimetry, the authors have performed some experiments using mannose and glucose. The characteristics of pure mannose and glucose were determined; and parameter like selection of the appropriate solvent, the granulometry of the powders, the amount of sugar used for each measurement were studied. The threshold dose was of the order of 5 Gy for both sugars. (author)

  3. Sex differences in glucose levels

    DEFF Research Database (Denmark)

    2010-01-01

    AIMS/HYPOTHESIS: We aimed to examine whether sex differences in fasting plasma glucose (FPG), 2 h post-OGTT plasma glucose (2hPG) and HbA(1c) could be explained by differences in body size and/or body composition between men and women in a general non-diabetic Danish population. Moreover, we aimed...... individuals. Height, weight and waist and hip circumferences were measured and BMI was calculated. Data were analysed in age-adjusted linear regression models. RESULTS: Men had higher FPG and HbA(1c) levels than women, and women had higher 2hPG levels than men. Sex differences in 2hPG levels were explained by...... differences in height and FPG levels, but sex differences in FPG or HbA(1c) levels were not explained by anthropometric measures. Among individuals with HbA(1c) in the high-risk range (6.0-6.5%), 73% had normal glucose tolerance. CONCLUSIONS/INTERPRETATION: Sex differences in 2hPG levels after an OGTT may to...

  4. Backtracking quantum trajectories with analog feedback

    Science.gov (United States)

    de Lange*, G.; Ristè*, D.; Tiggelman, M. J.; Eichler, C.; Tornberg, L.; Johansson, G.; Wallraff, A.; Schouten, R. N.; Dicarlo, L.

    2014-03-01

    Circuit quantum electrodynamics offers a nearly ideal platform for the fundamental study of continuous quantum measurement. A nondemolition measurement of a superconducting qubit can be performed via homodyne detection of microwave transmission through a dispersively coupled cavity. By boosting the homodyne signal with a nearly noiseless phase-sensitive parametric amplifier, we experimentally show that a form of measurement backaction, consisting of stochastic quantum phase kicks on the measured qubit, is highly correlated with the fluctuations in the continuous homodyne record. We demonstrate a real-time analog feedback scheme that counteracts these phase kicks and thereby reduces measurement-induced dephasing. We develop a numerical optimization technique to overcome the bandwidth limitations of the amplification chain and provide a theoretical model for the optimization result. A quantum efficiency of 50% is extracted for the complete analog feedback loop. Finally, we discuss the integration of this analog feedback technique to improve performance in our recent demonstration of entanglement by dispersive parity measurement. *equal contribution. Research funded by NWO and the EU projects SOLID and SCALEQIT.

  5. Hyperglycemia (High Blood Glucose)

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  6. Hyperglycemia (High Blood Glucose)

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  7. Hyperglycemia (High Blood Glucose)

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  8. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... Diabetes > Treatment and Care > Blood Glucose Testing Share: Print Page Text Size: A A A Listen En ... Reed challenges you to take the Diabetes Risk Test! » « Connect With Us Register for diabetes news, research ...

  9. Hyperglycemia (High Blood Glucose)

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  10. Hyperglycemia (High Blood Glucose)

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  11. Hyperglycemia (High Blood Glucose)

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  12. Hyperglycemia (High Blood Glucose)

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  13. Hyperglycemia (High Blood Glucose)

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  14. Hyperglycemia (High Blood Glucose)

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  15. Hyperglycemia (High Blood Glucose)

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  16. Continuous Glucose Monitoring

    Science.gov (United States)

    ... of Events Upcoming and past meetings Follow Us Social media, RSS feeds, and more Follow Us Health Information > ... Meters Juvenile Diabetes (Teens and Diabetes ) Know Your Blood Glucose Numbers Your ...

  17. Hyperglycemia (High Blood Glucose)

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  18. Hyperglycemia (High Blood Glucose)

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  19. Hyperglycemia (High Blood Glucose)

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  20. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To ... planned or exercised less than planned. You have stress from an illness, such as a cold or ...

  1. Glucose urine test

    Science.gov (United States)

    Urine sugar test; Urine glucose test; Glucosuria test; Glycosuria test ... After you provide a urine sample, it is tested right away. The health care provider uses a dipstick made with a color-sensitive pad. The ...

  2. Hyperglycemia (High Blood Glucose)

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  3. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... Care Blood Glucose Testing Medication Doctors, Nurses & More Oral Health & Hygiene Women A1C Insulin Pregnancy 8 Tips ... that smells fruity Nausea and vomiting Very dry mouth Talk to your doctor about how to handle ...

  4. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... In Memory In Honor Become a Member En Español Type 1 Type 2 About Us Online Community ... Page Text Size: A A A Listen En Español Hyperglycemia (High Blood Glucose) Hyperglycemia is the technical ...

  5. Nocturnal continuous glucose monitoring

    DEFF Research Database (Denmark)

    Bay, Christiane; Kristensen, Peter Lommer; Pedersen-Bjergaard, Ulrik; Tarnow, Lise; Thorsteinsson, Birger

    2013-01-01

    Abstract Background: A reliable method to detect biochemical nocturnal hypoglycemia is highly needed, especially in patients with recurrent severe hypoglycemia. We evaluated reliability of nocturnal continuous glucose monitoring (CGM) in patients with type 1 diabetes at high risk of severe...

  6. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Physical Activity High Blood Glucose My Health Advisor Tools To Know Your Risk Alert Day Diabetes Basics ... Advocacy Easy Advocacy Checklists for Association Events Messaging Tools Recruiting Advocates Local Market Planning Training Webinars News & ...

  7. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools ... planned or exercised less than planned. You have stress from an illness, such as a cold or ...

  8. Hyperglycemia (High Blood Glucose)

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  9. Hyperglycemia (High Blood Glucose)

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  10. Hyperglycemia (High Blood Glucose)

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  11. Hyperglycemia (High Blood Glucose)

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  12. Hyperglycemia (High Blood Glucose)

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  13. All about Blood Glucose

    Science.gov (United States)

    What are the blood glucose targets for people with diabetes? TargetssetbytheAmerican DiabetesAssociation (ADA)arelistedbelow. Talkwithyourhealthcareteam aboutyour personalgoals. What’s the best way to keep track ...

  14. Glucose: Detection and analysis.

    Science.gov (United States)

    Galant, A L; Kaufman, R C; Wilson, J D

    2015-12-01

    Glucose is an aldosic monosaccharide that is centrally entrenched in the processes of photosynthesis and respiration, serving as an energy reserve and metabolic fuel in most organisms. As both a monomer and as part of more complex structures such as polysaccharides and glucosides, glucose also plays a major role in modern food products, particularly where flavor and or structure are concerned. Over the years, many diverse methods for detecting and quantifying glucose have been developed; this review presents an overview of the most widely employed and historically significant, including copper iodometry, HPLC, GC, CZE, and enzyme based systems such as glucose meters. The relative strengths and limitations of each method are evaluated, and examples of their recent application in the realm of food chemistry are discussed. PMID:26041177

  15. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Doctors, Nurses & More Oral Health & Hygiene Women A1C Insulin Pregnancy 8 Tips for Caregivers Health Insurance Health ... glucose happens when the body has too little insulin or when the body can't use insulin ...

  16. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... Information Legal Assistance Success Stories Complications Hypoglycemia Hyperglycemia Skin Complications Eye Complications Neuropathy Foot Complications DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Treatment & Care Blood Glucose Testing Medication Doctors, Nurses & ...

  17. The immediate effects of a single bout of aerobic exercise on oral glucose tolerance across the glucose tolerance continuum

    DEFF Research Database (Denmark)

    Knudsen, Sine H; Karstoft, Kristian

    2014-01-01

    We investigated glucose tolerance and postprandial glucose fluxes immediately after a single bout of aerobic exercise in subjects representing the entire glucose tolerance continuum. Twenty-four men with normal glucose tolerance (NGT), impaired glucose tolerance (IGT), or type 2 diabetes (T2D; age: 56 ± 1 years; body mass index: 27.8 ± 0.7 kg/m(2), P > 0.05) underwent a 180-min oral glucose tolerance test (OGTT) combined with constant intravenous infusion of [6,6-(2)H2]glucose and ingestion of [U-(13)C]glucose, following 1 h of exercise (50% of peak aerobic power) or rest. In both trials, plasma glucose concentrations and kinetics, insulin, C-peptide, and glucagon were measured. Rates (mg kg(-1) min(-1)) of glucose appearance from endogenous (RaEndo) and exogenous (oral glucose; Ra OGTT) sources, and glucose disappearance (Rd) were determined. We found that exercise increased RaEndo, RaOGTT, and Rd (all P < 0.0001) in all groups with a tendency for a greater (~20%) peak RaOGTT value in NGT subjects when compared to IGT and T2D subjects. Accordingly, following exercise, the plasma glucose concentration during the OGTT was increased in NGT subjects (P < 0.05), while unchanged in subjects with IGT and T2D. In conclusion, while a single bout of moderate-intensity exercise increased the postprandial glucose response in NGT subjects, glucose tolerance following exercise was preserved in the two hyperglycemic groups. Thus, postprandial plasma glucose responses immediately following exercise are dependent on the underlying degree of glycemic control.

  18. Predicting Plasma Glucose From Interstitial Glucose Observations Using Bayesian Methods

    DEFF Research Database (Denmark)

    Hansen, Alexander Hildenbrand; Duun-Henriksen, Anne Katrine

    2014-01-01

    One way of constructing a control algorithm for an artificial pancreas is to identify a model capable of predicting plasma glucose (PG) from interstitial glucose (IG) observations. Stochastic differential equations (SDEs) make it possible to account both for the unknown influence of the continuous glucose monitor (CGM) and for unknown physiological influences. Combined with prior knowledge about the measurement devices, this approach can be used to obtain a robust predictive model. A stochastic-differential-equation-based gray box (SDE-GB) model is formulated on the basis of an identifiable physiological model of the glucoregulatory system for type 1 diabetes mellitus (T1DM) patients. A Bayesian method is used to estimate robust parameters from clinical data. The models are then used to predict PG from IG observations from 2 separate study occasions on the same patient. First, all statistically significant diffusion terms of the model are identified using likelihood ratio tests, yielding inclusion of ?Isc, ?Gp, and ?Gsc . Second, estimates using maximum likelihood are obtained, but prediction capability is poor. Finally a Bayesian method is implemented. Using this method the identified models are able to predict PG using only IG observations. These predictions are assessed visually. We are also able to validate these estimates on a separate data set from the same patient. This study shows that SDE-GBs and a Bayesian method can be used to identify a reliable model for prediction of PG using IG observations obtained with a CGM. The model could eventually be used in an artificial pancreas.

  19. Parking Structures: Fuss Analogs

    CERN Document Server

    Rhoades, Brendon

    2012-01-01

    For any irreducible real reflection group $W$ with Coxeter number $h$, Armstrong, Reiner, and the author introduced a pair of $W \\times \\ZZ_h$-modules which deserve to be called {\\sf $W$-parking spaces} which generalize the type A notion of parking functions and conjectured a relationship between them. In this paper we give a Fuss analog of their constructions. For a Fuss parameter $k \\geq 1$, we define a pair of $W \\times \\ZZ_{kh}$-modules which deserve to be called {\\sf $k$-$W$-parking spaces} and conjecture a relationship between them. We prove the weakest version of our conjectures for each of the infinite families ABCDI of finite reflection groups, together with proofs of stronger versions in special cases. Whenever our weakest conjecture holds for $W$, we have the following corollaries. First, there is a simple formula for the character of either $k$-$W$-parking space. Second, we recover a cyclic sieving result due to Krattenthaler and M\\"uller which gives the cycle structure of a generalized rotation a...

  20. A Rational Reconstruction of ANALOGY

    OpenAIRE

    Yeli Zhu

    2009-01-01

    The idea of this project is to reconstruct Evans ANALGOY program (1968) that solved geometric-analogy problems. The report reviews the work of Evans on geometric analogies and explains the functionality, the proposed design and development for the new system. The report contains the timeline, the original documentation for the project, and the source code for the new system as well.

  1. Natural analog studies: Licensing perspective

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, J.W. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-09-01

    This report describes the licensing perspective of the term {open_quotes}natural analog studies{close_quotes} as used in CFR Part 60. It describes the misunderstandings related to its definition which has become evident during discussions at the U.S Nuclear Regulatory Commission meetings and tries to clarify the appropriate applications of natural analog studies to aspects of repository site characterization.

  2. Bayesian Analogy with Relational Transformations

    Science.gov (United States)

    Lu, Hongjing; Chen, Dawn; Holyoak, Keith J.

    2012-01-01

    How can humans acquire relational representations that enable analogical inference and other forms of high-level reasoning? Using comparative relations as a model domain, we explore the possibility that bottom-up learning mechanisms applied to objects coded as feature vectors can yield representations of relations sufficient to solve analogy…

  3. Hepatic glucose sensing is required to preserve ? cell glucose competence

    OpenAIRE

    Seyer, Pascal; Vallois, David; Poitry-Yamate, Carole; Schutz, Frédéric; Metref, Salima; Tarussio, David; Maechler, Pierre; Staels, Bart; Lanz, Bernard; Grueter, Rolf; Decaris, Julie; Turner, Scott; da Costa, Anabela; Preitner, Frédéric; Minehira, Kaori

    2013-01-01

    Liver glucose metabolism plays a central role in glucose homeostasis and may also regulate feeding and energy expenditure. Here we assessed the impact of glucose transporter 2 (Glut2) gene inactivation in adult mouse liver (LG2KO mice). Loss of Glut2 suppressed hepatic glucose uptake but not glucose output. In the fasted state, expression of carbohydrate-responsive element-binding protein (ChREBP) and its glycolytic and lipogenic target genes was abnormally elevated. Feeding, energy expenditu...

  4. Evaluation of the relationship between capillary and venous plasma glucose concentrations obtained by the HemoCue Glucose 201+ system during an oral glucose tolerance test.

    Science.gov (United States)

    Ignell, Claes; Berntorp, Kerstin

    2011-12-01

    In 55 women with previous gestational diabetes mellitus, simultaneous capillary and venous plasma glucose concentrations were measured at 0, 30 and 120 min during a 75 g oral glucose tolerance test (OGTT). The aims of the study were to examine the relationship between capillary and venous glucose measurements, and to establish equations for the conversion of capillary and venous glucose concentrations using the HemoCue Glucose 201+ system. Additionally, the correlation between the capillary and venous glucose concentrations with the diagnostic cut-off limits proposed by the World Health Organization (WHO) in 1999 was evaluated. Capillary glucose concentrations were consistently higher than venous glucose concentrations at all time points of the OGTT (p < 0.001), and the correlations between the measurements were statistically highly significant (p < 0.001). The differences between the samples were greatest in the non-fasting state as revealed by the 95% prediction intervals (mmol/L) in Bland-Altman plots; ± 0.54 at 0 min, ± 2.01 at 30 min, and ± 1.35 at 120 min. Equivalence values for capillary plasma glucose concentrations derived from this study tended to be higher than those proposed by the WHO as diagnostic cut-off limits. Stratifying subjects by glucose tolerance status according to the WHO criteria revealed disagreements related to glucose values close to the diagnostic cut-off points. The study findings highlight the uncertainty associated with derived equivalence values. However, capillary plasma glucose measurements could be suitable for diagnostic purposes in epidemiological studies and when translating results on a group basis. PMID:21961814

  5. Multivariate image processing technique for noninvasive glucose sensing

    Science.gov (United States)

    Webb, Anthony J.; Cameron, Brent D.

    2010-02-01

    A potential noninvasive glucose sensing technique was investigated for application towards in vivo glucose monitoring for individuals afflicted with diabetes mellitus. Three dimensional ray tracing simulations using a realistic iris pattern integrated into an advanced human eye model are reported for physiological glucose concentrations ranging between 0 to 500 mg/dL. The anterior chamber of the human eye contains a clear fluid known as the aqueous humor. The optical refractive index of the aqueous humor varies on the order of 1.5x10-4 for a change in glucose concentration of 100 mg/dL. The simulation data was analyzed with a developed multivariate chemometrics procedure that utilizes iris-based images to form a calibration model. Results from these simulations show considerable potential for use of the developed method in the prediction of glucose. For further demonstration, an in vitro eye model was developed to validate the computer based modeling technique. In these experiments, a realistic iris pattern was placed in an analog eye model in which the glucose concentration within the fluid representing the aqueous humor was varied. A series of high resolution digital images were acquired using an optical imaging system. These images were then used to form an in vitro calibration model utilizing the same multivariate chemometric technique demonstrated in the 3-D optical simulations. In general, the developed method exhibits considerable applicability towards its use as an in vivo platform for the noninvasive monitoring of physiological glucose concentration.

  6. Evaluation and clinically relevant applications of a fluorescent imaging analog to fluorodeoxyglucose positron emission tomography

    OpenAIRE

    Sheth, Rahul A; Josephson, Lee; Mahmood, Umar

    2009-01-01

    A fluorescent analog to 2-deoxy-2 [18F] fluoro-D-glucose position emission tomography (FDG-PET) would allow for the introduction of metabolic imaging into intraoperative and minimally invasive settings. We present through in vitro and in vivo experimentation an evaluation of 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG), a fluorescently labeled glucose molecule, as a molecular beacon of glucose utilization. The competitive inhibition of 2-NBDG uptake by excess free gl...

  7. Evaluation of Postprandial Glucose Excursion Using a Novel Minimally Invasive Glucose Area-Under-the-Curve Monitoring System

    OpenAIRE

    Kuranuki, Sachi; Sato, Toshiyuki; Okada, Seiki; Hosoya, Samiko; Seko, Akinobu; Sugihara, Kaya; Nakamura, Teiji

    2013-01-01

    Objective: To develop a minimally invasive interstitial fluid extraction technology (MIET) to monitor postprandial glucose area under the curve (AUC) without blood sampling, we evaluated the accuracy of glucose AUC measured by MIET and compared with that by blood sampling after food intake. Methods: Interstitial fluid glucose AUC (IG-AUC) following consumption of 6 different types of foods was measured by MIET. MIET consisted of stamping microneedle arrays, placing hydrogel patches on the are...

  8. 14C-glucose binding assay of the glucose transporter binding sites in muscular cell membrane

    International Nuclear Information System (INIS)

    A method of determining the binding sites of glucose transporter in rat muscular cell membrane was introduced. The crude products of cell membrane form the skeletal muscle of control and insulin treated rats were prepared, and then fractionated in sucrose gradient. Both plasma membrane and microsome membrane were incubated with D-[U-14C] glucose respectively for the measurement of radioactivity and Scatchard plot analysis. It was found that the binding sites of glucose transporter in plasma membrane and intracellular membrane were 5.6 nmol 14C-glucose/mg protein and 8.7 nmol 14C-glucose-mg protein respectively at basic state. Insulin treatment in experimental groups caused approximately 146% increase in plasma membrane fraction and 88% decrease in intracellular membrane fraction. Moreover, the kinetic data of Scatchard plot curve were similar to those of the [3H]-cytochalasin B binding assay. D-[U-14C] glucose binding assay of glucose transporter binding sites in muscular cell membrane is simple, easy and practicable. The D-[U-14C] glucose is commercially available

  9. Intensive insulin treatment in critically ill trauma patients normalizes glucose by reducing endogenous glucose production.

    Science.gov (United States)

    Thorell, Anders; Rooyackers, Olav; Myrenfors, Peter; Soop, Mattias; Nygren, Jonas; Ljungqvist, Olle H

    2004-11-01

    Critical illness is associated with insulin resistance and hyperglycemia. Intensive insulin treatment to normalize blood glucose during feeding has been shown to improve morbidity and mortality in patients in intensive care. The mechanisms behind the glucose-controlling effects of insulin in stress are not well understood. Six previously healthy, severely traumatized patients (injury severity score > 15) were studied early (24-48 h) after trauma. Endogenous glucose production (EGP) and whole-body glucose disposal (WGD) were measured (6,6-(2)H(2)-glucose) at basal, during total parenteral nutrition (TPN), and during TPN plus insulin to normalize blood glucose (TPN+I). Six matched volunteers served as controls. At basal and TPN, concentrations of glucose and insulin were higher in patients (P TPN+I, insulin concentrations were 30-fold higher in patients. At basal, WGD and EGP were 30% higher in patients (P TPN, EGP decreased in both groups but less in patients, resulting in 110% higher EGP than controls (P TPN or TPN+I and was not different between the groups. In conclusion, in healthy subjects, euglycemia is maintained during TPN at physiological insulin concentrations by a reduction of EGP, whereas WGD is maintained at basal levels. In traumatized patients, hyperglycemia is due to increased EGP. In contrast to controls, normalization of glucose concentration during TPN needs high insulin infusion rates and is accounted for by a reduction in EGP, whereas WGD is not increased. PMID:15531485

  10. Kidney transplantation improves arterial function measured by pulse wave analysis and endothelium-independent dilatation in uraemic patients despite deterioration of glucose metabolism

    DEFF Research Database (Denmark)

    Hornum, Mads; Clausen, Peter; Idorn, Thomas; Hansen, Jesper Melchior; Mathiesen, Elisabeth R; Feldt-Rasmussen, Bo

    2011-01-01

    BACKGROUND: The aim of this study is to investigate the effect of kidney transplantation on arterial function in relation to changes in glucose metabolism. METHODS: Included were 40 kidney recipients (Tx group, age 38 ± 13 years) and 40 patients without known diabetes remaining on the waiting list...... for kidney transplantation (uraemic control group, age 47 ± 11 years). Arterial function was estimated by the pulse wave velocity (PWV) of the carotid-femoral pulse wave, aortic augmentation index (AIX), flow-mediated (FMD) and nitroglycerin-induced vasodilatation (NID) of the brachial artery...... performed before transplantation and after 12 months. PWV recorded sequentially at the carotid and femoral artery is an estimate of arterial stiffness; AIX is an integrated index of vascular and ventricular function. FMD and NID are the dilatory capacities of the brachial artery after increased flow...

  11. Glucose oxidase--an overview.

    Science.gov (United States)

    Bankar, Sandip B; Bule, Mahesh V; Singhal, Rekha S; Ananthanarayan, Laxmi

    2009-01-01

    Glucose oxidase (beta-D-glucose:oxygen 1-oxidoreductase; EC 1.1.2.3.4) catalyzes the oxidation of beta-D-glucose to gluconic acid, by utilizing molecular oxygen as an electron acceptor with simultaneous production of hydrogen peroxide. Microbial glucose oxidase is currently receiving much attention due to its wide applications in chemical, pharmaceutical, food, beverage, clinical chemistry, biotechnology and other industries. Novel applications of glucose oxidase in biosensors have increased the demand in recent years. Present review discusses the production, recovery, characterization, immobilization and applications of glucose oxidase. Production of glucose oxidase by fermentation is detailed, along with recombinant methods. Various purification techniques for higher recovery of glucose oxidase are described here. Issues of enzyme kinetics, stability studies and characterization are addressed. Immobilized preparations of glucose oxidase are also discussed. Applications of glucose oxidase in various industries and as analytical enzymes are having an increasing impact on bioprocessing. PMID:19374943

  12. Comparison of salivary and serum glucose levels in diabetic patients.

    Science.gov (United States)

    Gupta, Shruti; Sandhu, Simarpreet Virk; Bansal, Himanta; Sharma, Deepti

    2015-01-01

    Diabetes mellitus is a noncommunicable disease with a rising prevalence worldwide and in developing countries. The most commonly used diagnostic biofluid for detection of glucose levels is blood, but sample collection is an invasive and painful procedure. Thus, there arises a need for a noninvasive and painless technique to detect glucose levels. The objectives of the present study were to estimate the glucose levels of saliva, to assess if any significant correlation existed between the serum and salivary glucose levels, and to correlate salivary glucose levels with regard to duration of diabetes, age, and gender. In the present study, serum and salivary glucose levels of 200 subjects (100 diabetic subjects and 100 nondiabetic subjects) were estimated by glucose oxidase method. Glycosylated hemoglobin levels were also measured in randomly selected 40 diabetic subjects. The findings of present study revealed a significant correlation between salivary and serum glucose levels in both diabetic and nondiabetic subjects. No significant relationship was observed between salivary glucose levels and gender or age in both diabetics and nondiabetics and between salivary glucose levels and duration of diabetes in diabetics. On the basis of the findings, it was concluded that salivary glucose levels could serve as a potentially noninvasive adjunct to monitor glycemic control in diabetic patients. PMID:25294888

  13. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J M

    2010-01-01

    The design of an analog-to-digital converter or digital-to-analog converter is one of the most fascinating tasks in micro-electronics. In a converter the analog world with all its intricacies meets the realm of the formal digital abstraction. Both disciplines must be understood for an optimum conversion solution. In a converter also system challenges meet technology opportunities. Modern systems rely on analog-to-digital converters as an essential part of the complex chain to access the physical world. And processors need the ultimate performance of digital-to-analog converters to present the results of their complex algorithms. The same progress in CMOS technology that enables these VLSI digital systems creates new challenges for analog-to-digital converters: lower signal swings, less power and variability issues. Last but not least, the analog-to-digital converter must follow the cost reduction trend. These changing boundary conditions require micro-electronics engineers to consider their design choices for...

  14. Analogic fiber optic position sensor with nanometric resolution

    OpenAIRE

    Lamarque, Frédéric; Prelle, Christine

    2002-01-01

    This paper describes a miniature analogic position sensor. This sensor is dedicated to high resolution displacement measurement (10 nm) between two positions on long range (few millimeters). The working principle of the sensor is presented as well as experimentation results.

  15. Relationship between blood glucose and carotid intima media thickness: A meta-analysis

    OpenAIRE

    Einarson Thomas R; Hunchuck Jonathan; Hemels Michiel

    2010-01-01

    Abstract Background Increased coronary intima media thickness (CIMT) has been associated with adverse cardiovascular outcomes, as have increased glucose levels. The link has not been established between glucose and CIMT; therefore, we sought to assess the relationship between glucose and CIMT. Methods Medline, EMBASE, Scopus, and Cochrane databases were searched from inception through 2009 for original research reporting both postprandial glucose levels and CIMT measurements. Glucose was clas...

  16. Analog systems for gravity duals

    Science.gov (United States)

    Hossenfelder, Sabine

    2015-06-01

    We show that analog gravity systems exist for charged, planar black holes in asymptotic anti-de Sitter space. These black holes have been employed to describe, via the gauge-gravity duality, strongly coupled condensed matter systems on the boundary of anti-de Sitter (AdS) space. The analog gravity system is a different condensed matter system that, in a suitable limit, describes the same bulk physics as the theory on the AdS boundary. This combination of the gauge-gravity duality and analog gravity therefore suggests a duality between different condensed matter systems.

  17. Analog Systems for Gravity Duals

    OpenAIRE

    Hossenfelder, S.

    2014-01-01

    We show that analog gravity systems exist for charged, planar black holes in asymptotic Anti-de Sitter space. These black holes have been employed to describe, via the gauge-gravity duality, strongly coupled condensed matter systems on the boundary of AdS-space. The analog gravity system is a different condensed matter system that, in a suitable limit, describes the same bulk physics as the theory on the AdS boundary. This combination of the gauge-gravity duality and analog ...

  18. Sensing of Salivary Glucose Using Nano-Structured Biosensors

    OpenAIRE

    Yunqing Du; Wenjun Zhang; Wang, Ming L.

    2016-01-01

    The anxiety and pain associated with frequent finger pricking has always been troublesome for diabetics measuring blood glucose (BG) in their daily lives. For this reason, a reliable glucose monitoring system that allows noninvasive measurements is highly desirable. Our main objective is to develop a biosensor that can detect low-level glucose in saliva (physiological range 0.5–20 mg/dL). Salivary glucose (SG) sensors were built using a layer-by-layer self-assembly of single-walled carbon nan...

  19. The exoplanets analogy to the Multiverse

    OpenAIRE

    Kinouchi, Osame

    2015-01-01

    The idea of a Mutiverse is controversial, although it is a natural possible solution to particle physics and cosmological fine-tuning problems (FTPs). Here I explore the analogy between the Multiverse proposal and the proposal that there exist an infinite number of stellar systems with planets in a flat Universe, the Multiplanetverse. Although the measure problem is present in this scenario, the idea of a Multiplanetverse has predictive power, even in the absence of direct e...

  20. Return of the glucoreceptor: Glucose activates the glucose-sensing receptor T1R3 and facilitates metabolism in pancreatic ?-cells.

    Science.gov (United States)

    Kojima, Itaru; Nakagawa, Yuko; Ohtsu, Yoshiaki; Hamano, Kunihisa; Medina, Johan; Nagasawa, Masahiro

    2015-05-01

    Subunits of the sweet taste receptor, namely T1R2 and T1R3, are expressed in mouse pancreatic islets. Quantitatively, the expression of messenger ribonucleic acid for T1R2 is much lower than that of T1R3, and immunoreactive T1R2 is in fact undetectable. Presumably, a homodimer of T1R3 could function as a signaling receptor. Activation of this receptor by adding an artificial sweetener, sucralose, leads to an increase in intracellular adenosine triphosphate ([ATP]c). This increase in [ATP]c is observed in the absence of ambient glucose. Sucralose also augments elevation of [ATP]c induced by methylsuccinate, a substrate for mitochondria. Consequently, activation of T1R3 promotes metabolism in mitochondria and increases [ATP]c. 3-O-Methylglucose, a non-metabolizable analog of glucose, also increases [ATP]c. Conversely, knockdown of T1R3 attenuates elevation of [ATP]c induced by glucose. Hence, glucose promotes its own metabolism by activating T1R3 and augmenting ATP production. Collectively, a homodimer of T1R3 functions as a cell surface glucose-sensing receptor and participates in the action of glucose on insulin secretion. The glucose-sensing receptor T1R3 might be the putative glucoreceptor proposed decades ago by Niki et al. The glucose-sensing receptor is involved in the action of glucose and modulates glucose metabolism in pancreatic ?-cells. PMID:25969708

  1. Spatial relationship between tumor perfusion and endogeneous glucose distribution

    International Nuclear Information System (INIS)

    Earlier studies detecting glucose in tissue and solid tumors by bioluminescence imaging suggested, that glucose distribution patterns may be spatially related to functional vascularity. The purpose of this study was to evaluate this relationship by comparing glucose distribution patterns as determined by bioluminescence imaging to perfusion patterns of endogeneous Hoechst 33342 in rats bearing mammary carcinomas. R 3230 mammary carcinoma cells have been implanted subcutaneously into 7 female Fischer 344 rats. Two months post implantation, after injection of Hoechst 33342 the tumors were removed and snap frozen to conserve metabolite levels. Concomitantly, blood was sampled from the animals for analysis of glucose concentrations using a micodialysis analyzer. Cryosections of the tumors have been prepared, and every slice has been analyzed for both, Hoechst binding by fluorescence microscopy, and for glucose distribution patterns using bioluminescence imaging. In many cases vascular structures could be retrieved by the spatial pattern of glucose distribution. In some cases however, higher glucose concentrations could be found independent from Hoechst signal. On the other hand, regions of high Hoechst signal are not necessarily correlated with high glucose concentrations. When comparing blood and tissue glucose levels, tissue glucose content as measured with bioluminescence imaging (1.9-3.5 mM) is considerably lower than blood glucose (5.6-8.0 mM), demonstrating the expected gradient from blood to tissue. This study demonstrates the feasibility of monitoring glucose gradients in relation to functional vasculature throughout the body, from blood down to tissue or tumor and further, throughout the microenvironment of the solid tumor. Glucose distribution patterns may be an important tool in perfusion studies, e. g. in detecting the direction of blood flow in ex-vivo samples or in estimating glucose consumption rates of tumor cells adjacent to or in between perfused vessels

  2. 'We want analog signals'

    International Nuclear Information System (INIS)

    The article describes several transducers based on nuclear radiation, ranging from simple level detection to on-line measurement of flow and water content of wood shavings on a conveyor belt. (J.H.H.)

  3. Glucose-6-phosphatase deficiency

    Directory of Open Access Journals (Sweden)

    Labrune Philippe

    2011-05-01

    Full Text Available Abstract Glucose-6-phosphatase deficiency (G6P deficiency, or glycogen storage disease type I (GSDI, is a group of inherited metabolic diseases, including types Ia and Ib, characterized by poor tolerance to fasting, growth retardation and hepatomegaly resulting from accumulation of glycogen and fat in the liver. Prevalence is unknown and annual incidence is around 1/100,000 births. GSDIa is the more frequent type, representing about 80% of GSDI patients. The disease commonly manifests, between the ages of 3 to 4 months by symptoms of hypoglycemia (tremors, seizures, cyanosis, apnea. Patients have poor tolerance to fasting, marked hepatomegaly, growth retardation (small stature and delayed puberty, generally improved by an appropriate diet, osteopenia and sometimes osteoporosis, full-cheeked round face, enlarged kydneys and platelet dysfunctions leading to frequent epistaxis. In addition, in GSDIb, neutropenia and neutrophil dysfunction are responsible for tendency towards infections, relapsing aphtous gingivostomatitis, and inflammatory bowel disease. Late complications are hepatic (adenomas with rare but possible transformation into hepatocarcinoma and renal (glomerular hyperfiltration leading to proteinuria and sometimes to renal insufficiency. GSDI is caused by a dysfunction in the G6P system, a key step in the regulation of glycemia. The deficit concerns the catalytic subunit G6P-alpha (type Ia which is restricted to expression in the liver, kidney and intestine, or the ubiquitously expressed G6P transporter (type Ib. Mutations in the genes G6PC (17q21 and SLC37A4 (11q23 respectively cause GSDIa and Ib. Many mutations have been identified in both genes,. Transmission is autosomal recessive. Diagnosis is based on clinical presentation, on abnormal basal values and absence of hyperglycemic response to glucagon. It can be confirmed by demonstrating a deficient activity of a G6P system component in a liver biopsy. To date, the diagnosis is most commonly confirmed by G6PC (GSDIa or SLC37A4 (GSDIb gene analysis, and the indications of liver biopsy to measure G6P activity are getting rarer and rarer. Differential diagnoses include the other GSDs, in particular type III (see this term. However, in GSDIII, glycemia and lactacidemia are high after a meal and low after a fast period (often with a later occurrence than that of type I. Primary liver tumors and Pepper syndrome (hepatic metastases of neuroblastoma may be evoked but are easily ruled out through clinical and ultrasound data. Antenatal diagnosis is possible through molecular analysis of amniocytes or chorionic villous cells. Pre-implantatory genetic diagnosis may also be discussed. Genetic counseling should be offered to patients and their families. The dietary treatment aims at avoiding hypoglycemia (frequent meals, nocturnal enteral feeding through a nasogastric tube, and later oral addition of uncooked starch and acidosis (restricted fructose and galactose intake. Liver transplantation, performed on the basis of poor metabolic control and/or hepatocarcinoma, corrects hypoglycemia, but renal involvement may continue to progress and neutropenia is not always corrected in type Ib. Kidney transplantation can be performed in case of severe renal insufficiency. Combined liver-kidney grafts have been performed in a few cases. Prognosis is usually good: late hepatic and renal complications may occur, however, with adapted management, patients have almost normal life span. Disease name and synonyms Glucose-6-phosphatase deficiency or G6P deficiency or glycogen storage disease type I or GSDI or type I glycogenosis or Von Gierke disease or Hepatorenal glycogenosis.

  4. Towards power centric analog design

    OpenAIRE

    Svensson, Christer

    2015-01-01

    Power consumption of analog systems is poorly understoodtoday, in contrast to the very well developed analysis of digitalpower consumption. We show that there is good opportunity todevelop also the analog power understanding to a similar levelas the digital. Such an understanding will have a large impact inthe design of future electronic systems, where low power consumptionwill be crucial. Eventually we may reach a power centricanalog design methodology.

  5. High glucose impairs superoxide production from isolated blood neutrophils

    DEFF Research Database (Denmark)

    Perner, A; Nielsen, S E; Rask-Madsen, J

    2003-01-01

    Superoxide (O(2)(-)), a key antimicrobial agent in phagocytes, is produced by the activity of NADPH oxidase. High glucose concentrations may, however, impair the production of O(2)(-) through inhibition of glucose-6-phosphate dehydrogenase (G6PD), which catalyzes the formation of NADPH. This study measured the acute effects of high glucose or the G6PD inhibitor dehydroepiandrosterone (DHEA) on the production of O(2)(-) from isolated human neutrophils.

  6. Continuous Blood Glucose Monitoring: A Review and Preview

    OpenAIRE

    Saudek, Christopher D.

    1983-01-01

    Physicians inappropriately think of blood glucose as a stable value because technology reduces a continuously varying parameter into a point-in-time measurement. Continuous blood glucose monitoring (CBGM) will force us to change this bad habit. Data management principles are suggested which will be necessary for conceptualizing the new data. The physiology of normal blood glucose fluctuations will be studied for the first time and the diagnosis of diabetes will be duly defined. Most important...

  7. Autocorrelation optical coherence tomography for glucose quantification in blood

    Science.gov (United States)

    Ullah, H.; Gilanie, G.; Hussain, F.; Ahmad, E.

    2015-12-01

    We report a new method for glucose monitoring in blood tissue based on the autocorrelation function (ACF) analysis in Fourier domain optical coherence tomography (FD-OCT). We have determined the changes in OCT monitoring signals’ depth to characterize the modulations in ACFs for quantitative measurements of glucose concentrations in blood. We found that an increase in the concentration of glucose in blood results in decreased OCT monitoring signal due to the increase in the refractive index of the media.

  8. Variable Classifications of Glycemic Index Determined by Glucose Meters

    OpenAIRE

    Lin, Meng-Hsueh Amanda; Wu, Ming-Chang; Lin, Jenshinn

    2010-01-01

    The study evaluated and compared the differences of glucose responses, incremental area under curve (IAUC), glycemic index (GI) and the classification of GI values between measured by biochemical analyzer (Fuji automatic biochemistry analyzer (FAA)) and three glucose meters: Accue Chek Advantage (AGM), BREEZE 2 (BGM), and Optimum Xceed (OGM). Ten healthy subjects were recruited for the study. The results showed OGM yield highest postprandial glucose responses of 119.6 ± 1.5, followed by FAA, ...

  9. Project for a codable central unit for analog data acquisition

    International Nuclear Information System (INIS)

    The instrumentation for a 256 channel codable central processor intended for an operation in connection with a computer is presented. The computer indicates the adresses of the channels to be measured, orders the conversion, and acquires the results of measurements. The acquisition and computer coupling unit is located in a standard rock CAMAC (6 U 19inch., 25 positions); an example of configuration is given. The measurement velocity depends on the converter speed and dead time of analog circuits; for a ADC 1103 converter the total dead time is 6.5s min. The analog circuits are intended for +-10V range, the accuracy is 1/2n (2n is the number of bits). The result is acquired in words of 12 bits maximum. The information transfer and analog commutation (through integrated analog gates) are discussed

  10. Genetic Algorithm Tuning of PID Controller in Smith Predictor for Glucose Concentration Control

    OpenAIRE

    Tsonyo Slavov; Olympia Roeva

    2011-01-01

    This paper focuses on design of a glucose concentration control system based on nonlinear model plant of E. coli MC4110 fed-batch cultivation process. Due to significant time delay in real time glucose concentration measurement, a correction is proposed in glucose concentration measurement and a Smith predictor (SP) control structure based on universal PID controller is designed. To reduce the influence of model error in SP structure the estimate of measured glucose concentration is used. For...

  11. Oxytocin increases extrapancreatic glucagon secretion and glucose production in pancreatectomized dogs

    International Nuclear Information System (INIS)

    Infusion of oxytocin into normal dogs increases plasma levels of insulin and glucagon and glucose production and uptake. To determine whether infused oxytocin also increases glucagon secretion from extrapancreatic sites, pancreatectomized dogs, off insulin of 18 hr, were infused with oxytocin and plasma glucagon, and glucose production and uptake were measured using the [6-3H]glucose primer-infusion technique. The diabetic dogs, in the control period, had elevated plasma glucose and glucagon levels, an increased rate of glucose production, and a relative decrease in glucose uptake (decreased clearance). Infusion of oxytocin (500 ?U/kg/min) caused a rise in plasma glucagon and glucose levels, increased glucose production, and further decreased glucose clearance. it is concluded that oxytocin can stimulate secretion of extrapancreatic glucagon, which contributes to the increased glucose production

  12. Glucose feeding exacerbates parathion-induced neurotoxicity.

    Science.gov (United States)

    Olivier, K; Liu, J; Karanth, S; Zhang, H; Roane, D S; Pope, C N

    2001-06-22

    Excessive dietary intake of sugars could alter various biotransformation processes and the pharmacological and toxicological properties of numerous xenobiotics. In the present study, the effects of glucose supplementation were examined on the neurotoxicity of the organophosphorus (OP) pesticide parathion (PS) and its active metabolite, paraoxon (PO), a potent inhibitor of acetylcholinesterase (AChE). Rats (n = 6-12/treatment group) were given free access to tap water or 15% glucose (w/v) in tap water beginning 7 d prior to OP toxicant exposure. Food, caloric intake, and body weight were measured daily. Animals were challenged with either PS (4.5, 9, or 18 mg/kg, sc) or PO (0.3 0.5, or 0.7 mg/kg, sc) and clinical signs of neurotoxicity (i.e., autonomic dysfunction, involuntary movements) were recorded daily for the following 13 d. Glucose feeding was associated with a dramatic drop (approximately 50%) in feed intake and an increase (approximately 20% in total caloric consumption over the 7 d prior to OP exposure. Functional toxicity associated with PS exposure was increased in glucose-fed (GF) rats, but the glucose diet had no apparent effect on clinical signs of toxicity following PO treatment. Glucose feeding increased the magnitude of AChE inhibition in the frontal cortex and plasma at lower dosages (i.e., 4.5 and 9 mg/kg) 3 d following PS treatment. Time-course studies (3, 7, and 11 d after PS exposure, 18 mg/kg, sc) indicated significantly greater brain and plasma AChE inhibition in glucose-fed animals at later time points. In contrast, glucose feeding had no effect on the degree of AChE inhibition following PO exposure. Neither liver microsomal oxidative desulfuration of PS, nor liver or plasma paraoxonase, nor liver or plasma carboxylesterase activities were measurably affected by glucose feeding. Downregulation of muscarinic receptors 7 d after PS exposure (18 mg/kg, sc) was more extensive in GF rats. It is postulated that excessiveglucose consumption decreases the intake of other dietary components, in particular amino acids, limiting the de novo synthesis of AChE and consequent recovery of synaptic transmission. Due to the shorter duration of inhibition following PO exposure, sponta neous reactivation of AChE may be more important than de novo protein synthesis in recovery of function, and thus with the effects of glucose feeding on its toxicity. Individuals that derive a large proportion of their calories from sugars may be at higher risk of acute toxicity from organophosphorus pesticides such as PS. PMID:11437059

  13. An ozone budget for the UK: using measurements from the national ozone monitoring network; measured and modelled meteorological data, and a 'big-leaf' resistance analogy model of dry deposition

    International Nuclear Information System (INIS)

    A method of calculating a mass budget for O3 in the UK boundary layer is presented which shows that the spatial scale of the UK is small relative to the footprint of the atmosphere influenced by UK emissions. - Data from the UK national air-quality monitoring network are used to calculate an annual mass budget for ozone (O3) production and loss in the UK boundary layer during 1996. Monthly losses by dry deposition are quantified from 1 kmx1 km scale maps of O3 concentration and O3 deposition velocities based on a 'big-leaf' resistance analogy. The quantity of O3 deposition varies from ?50 Gg-O3 month-1 in the winter to over 200 Gg-O3 month-1 in the summer when vegetation is actively absorbing O3. The net O3 production or loss in the UK boundary layer is found by selecting days when the UK is receiving 'clean' Atlantic air from the SW to NW. In these conditions, the difference in O3 concentration observed at Mace Head and a rural site on the east coast of the UK indicates the net O3 production or loss within the UK boundary layer. A simple box model is then used to convert the concentration difference into a mass. The final budget shows that for most of the year the UK is a net sink for O3 (-25 to -800 Gg-O3 month-1) with production only exceeding losses in the photochemically active summer months (+45 Gg-O3 month-1)

  14. An ozone budget for the UK: using measurements from the national ozone monitoring network; measured and modelled meteorological data, and a 'big-leaf' resistance analogy model of dry deposition

    Energy Technology Data Exchange (ETDEWEB)

    Coyle, M.; Smith, R.; Fowler, D

    2003-05-01

    A method of calculating a mass budget for O{sub 3} in the UK boundary layer is presented which shows that the spatial scale of the UK is small relative to the footprint of the atmosphere influenced by UK emissions. - Data from the UK national air-quality monitoring network are used to calculate an annual mass budget for ozone (O{sub 3}) production and loss in the UK boundary layer during 1996. Monthly losses by dry deposition are quantified from 1 kmx1 km scale maps of O{sub 3} concentration and O{sub 3} deposition velocities based on a 'big-leaf' resistance analogy. The quantity of O{sub 3} deposition varies from {approx}50 Gg-O{sub 3} month{sup -1} in the winter to over 200 Gg-O{sub 3} month{sup -1} in the summer when vegetation is actively absorbing O{sub 3}. The net O{sub 3} production or loss in the UK boundary layer is found by selecting days when the UK is receiving 'clean' Atlantic air from the SW to NW. In these conditions, the difference in O{sub 3} concentration observed at Mace Head and a rural site on the east coast of the UK indicates the net O{sub 3} production or loss within the UK boundary layer. A simple box model is then used to convert the concentration difference into a mass. The final budget shows that for most of the year the UK is a net sink for O{sub 3} (-25 to -800 Gg-O{sub 3} month{sup -1}) with production only exceeding losses in the photochemically active summer months (+45 Gg-O{sub 3} month{sup -1})

  15. Labelled antibody assays for measuring free triiodothyronine: evaluation and comparison with a labelled analog method. Dosages de la triiodothyronine libre utilisant un anticorps marque: evaluation et comparaison a un dosage avec traceur analogue

    Energy Technology Data Exchange (ETDEWEB)

    Sapin, R.; Gasser, F.; Schlienger, J.L.; Chambron, J. (Centre Hospitalier Universitaire, 67 - Strasbourg (France))

    1993-01-01

    We evaluated analytically and clinically two new one-step labelled antibody assays for measuring free triiodothyronine (FT3): the first, radiolabelled with [sup 125] I, Amerlex-MAB (MAB) from Kodak diagnostic, and the second, labelled with peroxidase, Enzymum-test FT3 (BM) from Boehringer Mannheim adapted for the Boehringer ES 600 analyzer. The clinical results were compared with those obtained with a radiolabelled analog tracer kit, Amerlex-M (M) from Kodak diagnostic. The latter kit is known to give low FT3 results in sera with low albumin concentrations. Analytical performances of the automated method (BM) were better than those obtained with the manual method (MAB): intra-assay reproducibility (CV<3% vs CV about 5%), inter-assay reproducibility (CV<4% vs CV between 4 and 8%) and mean drift (+1.25% vs -4.3%). The detection limit was low for both kits (<1 pmol/l). In the euthyroid reference group (n = 98) we observed a significant difference between outpatient and hospitalized patient FT3 concentrations as measured with the M kit only. Clinical sensitivity for hyperthyroidism (n = 38) was better for the MAB (92%) than for the BM kit (76%). Specificity in euthyroid L-thyroxine (T4) treated patients (n = 26) was good for both kits (MAB: 92%; BM: 88%) . Hypoalbuminemia (n = 8) decreased FT3 results as follows: M, very significantly; BM, significantly; MAB, only slightly. In patients treated with amiodarone (n = 5), a drug known to lower the metabolic conversion of T4 to T3, the increase of the MAB FT3 results contrasted with the decrease of the BM and M results. In conclusion, results of the two new kits were not strongly influenced by hypoalbuminemia. The MAB results showing lack of decrease in patients with non-thyroidal illness without hypoalbuminemia and in amiodarone-treated patients were unexpected.

  16. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... produces daily around 4:00 a.m. to 5:00 a.m.). What are the Symptoms of Hyperglycemia? The signs and symptoms include the following: High blood glucose High levels of sugar in the ...

  17. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... to 5:00 a.m.). What are the Symptoms of Hyperglycemia? The signs and symptoms include the following: High blood glucose High levels ... Ketoacidosis is life-threatening and needs immediate treatment. Symptoms include: Shortness of breath Breath that smells fruity ...

  18. Blood Glucose Monitoring Devices

    Science.gov (United States)

    ... are below 100 mg/dL before meals and fasting and are less than 140 mg/dL two hours after meals. People with diabetes should consult their doctor or health care provider to set appropriate blood glucose goals. ...

  19. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Size: A A A Listen En Español Hyperglycemia (High Blood Glucose) Hyperglycemia is the technical term for ... prepend(' ' + ' ' + this.errorMessage + ' ' + ' '); } }); $('.survey-form').show(); } else { $('.survey-loading').remove(); $('#emailsurvey').hide(); $('#emailsurveythanks').show(); } } }; /* bind any forms ...

  20. IMMOBILIZATION OF GLUCOSE OXIDASE IN SILICA SOL-GEL FILM FOR APPLICATION TO BIOSENSOR AND AMPEROMETRIC DETERMINATION OF GLUCOSE

    OpenAIRE

    N?ZAMETT?N DEM?RKIRAN; ERGUN EK?NC?; MELTEM AS?LTÜRK

    2012-01-01

    In this study, an electrochemical biosensor was developed by using a sol-gel coating solution. The modified platinum electrode used in the study was constructed by immobilization of glucose oxidase under a layer of sol-gel film. The sol-gel coating solution was prepared by using GLYMO, TEOS, and MTEOS. Electrochemical measurements were carried out amperometrically by determining hydrogen peroxide produced by the enzymatic reaction between glucose and glucose oxidase. The amperometric response...

  1. Glucose Regulates the Expression of the Apolipoprotein A5 Gene

    Energy Technology Data Exchange (ETDEWEB)

    Fruchart, Jamila; Nowak, Maxime; Helleboid-Chapman, Audrey; Jakel, Heidelinde; Moitrot, Emmanuelle; Rommens, Corinne; Pennacchio, Len A.; Fruchart-Najib, Jamila; Fruchart, Jean-Charles

    2008-04-07

    The apolipoprotein A5 gene (APOA5) is a key player in determining triglyceride concentrations in humans and mice. Since diabetes is often associated with hypertriglyceridemia, this study explores whether APOA5 gene expression is regulated by alteration in glucose homeostasis and the related pathways. D-glucose activates APOA5 gene expression in a time- and dose-dependent manner in hepatocytes, and the glycolytic pathway involved was determined using D-glucose analogs and metabolites. Together, transient transfections, electrophoretic mobility shift assays and chromatin immunoprecipitation assays show that this regulation occurs at the transcriptional level through an increase of USF1/2 binding to an E-box in the APOA5 promoter. We show that this phenomenon is not due to an increase of mRNA or protein expression levels of USF. Using protein phosphatases 1 and 2A inhibitor, we demonstrate that D-glucose regulates APOA5 gene via a dephosphorylation mechanism, thereby resulting in an enhanced USF1/2-promoter binding. Last, subsequent suppressions of USF1/2 and phosphatases mRNA through siRNA gene silencing abolished the regulation. We demonstrate that APOA5 gene is up regulated by D-glucose and USF through phosphatase activation. These findings may provide a new cross talk between glucose and lipid metabolism.

  2. Glucose biosensor based on glucose oxidase immobilized on unhybridized titanium dioxide nanotube arrays

    International Nuclear Information System (INIS)

    A glucose biosensor has been fabricated by immobilizing glucose oxidase (GOx) on unhybridized titanium dioxide nanotube arrays using an optimized cross-linking technique. The TiO2 nanotube arrays were synthesized directly on a titanium substrate by anodic oxidation. The structure and morphology of electrode material were characterized by X-ray diffraction and scanning electron microscopy. The electrochemical performances of the glucose biosensor were conducted by cyclic voltammetry and chronoamperometry measurements. It gives a linear response to glucose in the 0.05 to 0.65 mM concentration range, with a correlation coefficient of 0.9981, a sensitivity of 199.6 ?A mM?1 cm?2, and a detection limit as low as 3.8 µM. This glucose biosensor exhibited high selectivity for glucose determination in the presence of ascorbic acid, sucrose and other common interfering substances. This glucose biosensor also performed good reproducibility and long-time storage stability. This optimized cross-linking technique could open a new avenue for other enzyme biosensors fabrication. (author)

  3. Effects of MDMA on blood glucose levels and brain glucose metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Soto-Montenegro, M.L.; Vaquero, J.J.; Garcia-Barreno, P.; Desco, M. [Hospital General Universitario Gregorio Maranon, Laboratorio de Imagen, Medicina Experimental, Madrid (Spain); Arango, C. [Hospital General Gregorio Maranon, Departamento de Psiquiatria, Madrid (Spain); Ricaurte, G. [Johns Hopkins University School of Medicine, Department of Neurology, Baltimore, MD (United States)

    2007-06-15

    This study was designed to assess changes in glucose metabolism in rats administered single or repeated doses of MDMA. Two different experiments were performed: (1) A single-dose study with four groups receiving 20 mg/kg, 40 mg/kg, saline or heat, and (2) a repeated-dose study with two groups receiving three doses, at intervals of 2 h, of 5 mg/kg or saline. Rats were imaged using a dedicated small-animal PET scanner 1 h after single-dose administration or 7 days after repeated doses. Glucose metabolism was measured in 12 cerebral regions of interest. Rectal temperature and blood glucose were monitored. Peak body temperature was reached 1 h after MDMA administration. Blood glucose levels decreased significantly after MDMA administration. In the single-dose experiment, brain glucose metabolism showed hyperactivation in cerebellum and hypo-activation in the hippocampus, amygdala and auditory cortex. In the repeated-dose experiment, brain glucose metabolism did not show any significant change at day 7. These results are the first to indicate that MDMA has the potential to produce significant hypoglycaemia. In addition, they show that MDMA alters glucose metabolism in components of the motor, limbic and somatosensory systems acutely but not on a long-term basis. (orig.)

  4. Effects of MDMA on blood glucose levels and brain glucose metabolism

    International Nuclear Information System (INIS)

    This study was designed to assess changes in glucose metabolism in rats administered single or repeated doses of MDMA. Two different experiments were performed: (1) A single-dose study with four groups receiving 20 mg/kg, 40 mg/kg, saline or heat, and (2) a repeated-dose study with two groups receiving three doses, at intervals of 2 h, of 5 mg/kg or saline. Rats were imaged using a dedicated small-animal PET scanner 1 h after single-dose administration or 7 days after repeated doses. Glucose metabolism was measured in 12 cerebral regions of interest. Rectal temperature and blood glucose were monitored. Peak body temperature was reached 1 h after MDMA administration. Blood glucose levels decreased significantly after MDMA administration. In the single-dose experiment, brain glucose metabolism showed hyperactivation in cerebellum and hypo-activation in the hippocampus, amygdala and auditory cortex. In the repeated-dose experiment, brain glucose metabolism did not show any significant change at day 7. These results are the first to indicate that MDMA has the potential to produce significant hypoglycaemia. In addition, they show that MDMA alters glucose metabolism in components of the motor, limbic and somatosensory systems acutely but not on a long-term basis. (orig.)

  5. Close interrelationships among glucose oxidation

    International Nuclear Information System (INIS)

    The authors have reported that alloxan, a ?-cytotoxic agent, inhibited glucose oxidation and glucose-induced 45Ca uptake of pancreatic ?-cells; the non-?-cell mass was not inhibited by alloxan pretreatment. Therefore it is feasible to assess glucose metabolism and Ca uptake in the mass composed of ?-cells alone, by subtracting glucose oxidation and Ca uptake in the alloxan treated islets from the non-alloxan treatted islets. In order to elucidate the interrelationship between glycolysis, glucose-induced Ca uptake and insulin release in the pancreatic ?-cell mass, but not in the pancreatic islets, we investigated 14CO2 formation from 14C-U-D-glucose, glucose-induced 45Ca uptake and insulin release in alloxan treated and non-alloxan treated islets. In vitro incubation of collagenase digested isolated islets of Langerhans was employed. The relationships between the three parameters in the presumed pancreatic ?-cell mass (14CO2 formation from 14C-U-D-glucose, glucose-induced 45Ca uptake and insulin release) and glucose concentration in the media were clearly sigmoidal. The threshold values of the three parameters are approximately 5 mM of glucose. The half maximum rates of 14CO2 formation, 45Ca uptake and insulin release required 13.4 mM, 13.6 mM and 12.8 mM of glucose, respectively. The near maximum stimulation of the three parameters was obtained at 20 mM of glucose. (orig.)

  6. HAPS, a Handy Analog Programming System

    DEFF Research Database (Denmark)

    HØjberg, Kristian SØe

    1975-01-01

    HAPS (Hybrid Analog Programming System) is an analog compiler that can be run on a minicomputer in an interactive mode. Essentially HAPS is written in FORTRAN. The equations to be programmed for an ana log computer are read in by using a FORTRAN-like notation. The input must contain maximum and minimum values for the variables. The output file includes potentiometer coefficients and static-test 'measuring values.' The file format is fitted to an automatic potentiometer-setting and static-test program. Patch instructions are printed by HAPS. The article describes the principles of HAPS and emphasizes the limitations HAPS puts on equation structure, types of computing circuit, scaling, and static testing.

  7. Learning Plate Tectonics Using a Pre-Analogy Step

    Science.gov (United States)

    Glesener, G. B.; Sandoval, W. A.

    2011-12-01

    Previous research has shown that children tend to demonstrate lower performance on analogical reasoning tasks at a causal relations level compared to most adults (Gentner & Toupin, 1986). This tendency is an obstacle that geoscience educators must overcome because of the high frequency of analogies used in geoscience pedagogy. In particular, analog models are used to convey complex systems of non-everyday/non-observable events found in nature, such as plate tectonics. Key factors in successful analogical reasoning that have been suggested by researchers include knowledge of the causal relations in the base analog (Brown & Kane, 1988; Gentner, 1988; Gentner & Toupin, 1986), and development of learning strategies and metaconceptual competence(Brown & Kane, 1988). External factors, such as guiding cues and hints have been useful cognitive supports that help students reason through analogical problems (Gick & Holyoak, 1980). Cognitive supports have been seen by researchers to decrease processing demands on retrieval and working memory (Richland, Zur, & Holyoak, 2007). We observed third and fourth graders learning about plate tectonics beginning with a pre-analogy step-a cognitive support activity a student can do before working with an analogy to understand the target. This activity was designed to aid students in developing their understanding of object attributes and relations within an analog model so that more focus can be placed on mapping the corresponding higher-order relations between the base and target. Students learned targeted concepts of plate tectonics, as measured by pre to post gains on items adapted from the Geosciences Concept Inventory. Analyses of classroom interaction showed that students used the object attributes and higher-order relations highlighted in the pre-analogy activity as resources to reason about plate boundaries and plate movement during earthquakes.

  8. Interaction of Glucose with ZnO Nanoparticles

    Directory of Open Access Journals (Sweden)

    P.K. Samanta

    2014-06-01

    Full Text Available We report the results of the extent of interaction as well as the formation of a bioconjugate of glucose with Zinc Oxide nano particles (ZnO NPs to understand the non-invasive monitoring of glucose by semiconductor NPs. We performed an array of photophysical as well as microscopic measurements to quantify the interaction between ZnO NPs and glucose. We have found that time constant of interaction (t1 ? 18.47 min for the binding glucose with surface of ZnO NPs and follows a single exponential association process.

  9. Demographic and metabolic characteristics of individuals with progressive glucose tolerance

    Scientific Electronic Library Online (English)

    A.L., Mendes; M.L., Santos; C.R., Padovani; W.P., Pimenta.

    2009-03-01

    Full Text Available We evaluated changes in glucose tolerance of 17 progressors and 62 non-progressors for 9 years to improve our understanding of the pathogenesis of type 2 diabetes mellitus. Changes in anthropometric measurements and responses to an oral glucose tolerance test (OGTT) were analyzed. We identified 14 p [...] airs of individuals, one from each group, who were initially normal glucose tolerant and were matched for gender, age, weight, and girth. We compared initial plasma glucose and insulin curves (from OGTT), insulin secretion (first and second phases) and insulin sensitivity indices (from hyperglycemic clamp assay) for both groups. In the normal glucose tolerant phase, progressors presented: 1) a higher OGTT blood glucose response with hyperglycemia in the second hour and a similar insulin response vs non-progressors; 2) a reduced first-phase insulin secretion (2.0 ± 0.3 vs 2.3 ± 0.3 pmol/L; P

  10. Blood glucose in acute stroke

    DEFF Research Database (Denmark)

    Olsen, Tom Skyhøj

    2009-01-01

    Blood glucose is often elevated in acute stroke, and higher admission glucose levels are associated with larger lesions, greater mortality and poorer functional outcome. In patients treated with thrombolysis, hyperglycemia is associated with an increased risk of hemorrhagic transformation of...... risk of inducing potentially harmful hypoglycemia has been raised. Still, basic and observational research is overwhelmingly in support of a causal relationship between blood glucose and stroke outcome and further research on glucose-lowering therapy in acute stroke is highly warranted....

  11. Biomimetic Analogs for Collagen Biomineralization

    Science.gov (United States)

    Gu, L.; Kim, Y.K.; Liu, Y.; Ryou, H.; Wimmer, C.E.; Dai, L.; Arola, D.D.; Looney, S.W.; Pashley, D.H.; Tay, F.R.

    2011-01-01

    Inability of chemical phosphorylation of sodium trimetaphosphate to induce intrafibrillar mineralization of type I collagen may be due to the failure to incorporate a biomimetic analog to stabilize amorphous calcium phosphates (ACP) as nanoprecursors. This study investigated adsorption/desorption characteristics of hydrolyzed and pH-adjusted sodium trimetaphosphate (HPA-Na3P3O9) to collagen. Based on those results, a 5-minute treatment time with 2.8 wt% HPA-Na3P3O9 was used in a single-layer reconstituted collagen model to confirm that both the ACP-stabilization analog and matrix phosphoprotein analog must be present for intrafibrillar mineralization. The results of that model were further validated by complete remineralization of phosphoric-acid-etched dentin treated with the matrix phosphoprotein analog and lined with a remineralizing lining composite, and with the ACP-stabilization analog supplied in simulated body fluid. An understanding of the basic processes involved in intrafibrillar mineralization of reconstituted collagen fibrils facilitates the design of novel tissue engineering materials for hard tissue repair and regeneration. PMID:20940362

  12. Epigenome-wide association study of fasting measures of glucose, insulin, and HOMA-IR in the Genetics of Lipid Lowering Drugs and Diet Network study.

    Science.gov (United States)

    Hidalgo, Bertha; Irvin, M Ryan; Sha, Jin; Zhi, Degui; Aslibekyan, Stella; Absher, Devin; Tiwari, Hemant K; Kabagambe, Edmond K; Ordovas, Jose M; Arnett, Donna K

    2014-02-01

    Known genetic susceptibility loci for type 2 diabetes (T2D) explain only a small proportion of heritable T2D risk. We hypothesize that DNA methylation patterns may contribute to variation in diabetes-related risk factors, and this epigenetic variation across the genome can contribute to the missing heritability in T2D and related metabolic traits. We conducted an epigenome-wide association study for fasting glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) among 837 nondiabetic participants in the Genetics of Lipid Lowering Drugs and Diet Network study, divided into discovery (N = 544) and replication (N = 293) stages. Cytosine guanine dinucleotide (CpG) methylation at ?470,000 CpG sites was assayed in CD4(+) T cells using the Illumina Infinium HumanMethylation 450 Beadchip. We fit a mixed model with the methylation status of each CpG as the dependent variable, adjusting for age, sex, study site, and T-cell purity as fixed-effects and family structure as a random-effect. A Bonferroni corrected P value of 1.1 × 10(-7) was considered significant in the discovery stage. Significant associations were tested in the replication stage using identical models. Methylation of a CpG site in ABCG1 on chromosome 21 was significantly associated with insulin (P = 1.83 × 10(-7)) and HOMA-IR (P = 1.60 × 10(-9)). Another site in the same gene was significant for HOMA-IR and of borderline significance for insulin (P = 1.29 × 10(-7) and P = 3.36 × 10(-6), respectively). Associations with the top two signals replicated for insulin and HOMA-IR (P = 5.75 × 10(-3) and P = 3.35 × 10(-2), respectively). Our findings suggest that methylation of a CpG site within ABCG1 is associated with fasting insulin and merits further evaluation as a novel disease risk marker. PMID:24170695

  13. Study of diabetes using naturally enriched 13C-glucose

    International Nuclear Information System (INIS)

    Following the work undertaken by Duchesne et al. since 1968, results from the use of a new method in the area of glucose metabolism are presented. Because of differences in their photosynthetic pathway, some vegetables, e.g., maize and sugarcane, are a little richer in 13C than most common foodstuffs. This weak, but significant, enrichment allows the use of maize glucose as a natural and nonradioactive tracer. In this procedure the variations of the 13C/12C ratio of exhaled CO2 are measured by mass spectrometry. By this method, we can follow, in man, the complete conversion of an oral glucose load into CO2 during a glucose tolerance test. At the same time, measurements of blood glucose and of respiratory quotient are made. They permit a useful comparison of the level of glucose in blood, the total amount of glucose consumed, and the fraction of exogenous glucose burned in the hours following oral administration. New information was obtained from these studies concerning glucose metabolism. The method was used in normal subjects and in obese and diabetic patients. Some of the diabetics were receiving an oral antidiabetic treatment. Significant differences were obtained in these cases, not only between them but also with the information given by the classical methods

  14. Structure-function relationships affecting the sensing mechanism of monolayer-protected cluster doped xerogel amperometric glucose biosensors.

    Science.gov (United States)

    DiPasquale, Luke T; Poulos, Nicholas G; Hall, Jackson R; Minocha, Aastha; Bui, Tram Anh; Leopold, Michael C

    2015-07-15

    A systematic study of the structure-function relationships critical to understanding the sensing mechanism of 1st generation amperometric glucose biosensors with an embedded nanoparticle (NP) network is presented. Xerogel-based films featuring embedded glucose oxidase enzyme and doped with alkanethiolate-protected gold NPs, known as monolayer protected clusters (MPCs), exhibit significantly enhanced performance compared to analogous systems without NPs including higher sensitivity, faster response time, and extended linear/dynamic ranges. The proposed mechanism involves diffusion of the glucose to glucose oxidase within the xerogel, enzymatic reaction production of H2O2 with subsequent diffusion to the embedded network of MPCs where it is oxidized, an event immediately reported via fast electron transfer (ET) through the MPC system to the working electrode. Various aspects of the film construct and strategy are systematically probed using amperometry, voltammetry, and solid-state electronic conductivity measurements, including the effects of MPC peripheral chain length, MPC functionalization via place-exchange reaction, MPC core size, and the MPC density or concentration within the xerogel composite films. The collective results of these experiments support the proposed mechanism and identify interparticle spacing and the electronic communication through the MPC network is the most significant factor in the sensing scheme with the diffusional aspects of the mechanism that may be affected by film/MPC hydrophobicity and functionality (i.e., glucose and H2O2 diffusion) shown to be less substantial contributors to the overall enhanced performance. Understanding the structure-function relationships of effective sensing schemes allows for the employment of the strategy for future biosensor design toward clinically relevant targets. PMID:25819004

  15. When to Prove Theorems by Analogy?

    OpenAIRE

    Melis, Erica

    1999-01-01

    In recent years several computational systems and techniques fortheorem proving by analogy have been developed. The obvious prac-tical question, however, as to whether and when to use analogy hasbeen neglected badly in these developments. This paper addresses thisquestion, identifies situations where analogy is useful, and discussesthe merits of theorem proving by analogy in these situations. Theresults can be generalized to other domains.

  16. Theory of analogous force on number sets

    International Nuclear Information System (INIS)

    A general statistical thermodynamic theory that considers given sequences of x-integers to play the role of particles of known type in an isolated elastic system is proposed. By also considering some explicit discrete probability distributions px for natural numbers, we claim that they lead to a better understanding of probabilistic laws associated with number theory. Sequences of numbers are treated as the size measure of finite sets. By considering px to describe complex phenomena, the theory leads to derive a distinct analogous force fx on number sets proportional to (?px/?x)T at an analogous system temperature T. In particular, this yields to an understanding of the uneven distribution of integers of random sets in terms of analogous scale invariance and a screened inverse square force acting on the significant digits. The theory also allows to establish recursion relations to predict sequences of Fibonacci numbers and to give an answer to the interesting theoretical question of the appearance of the Benford's law in Fibonacci numbers. A possible relevance to prime numbers is also analyzed. (author)

  17. Enhancing students' science text learning and motivation through analogies

    Science.gov (United States)

    Carter, Timothy Lewis

    The purpose of the present study was to examine the role that analogies can play in enhancing middle-school students' learning of science text and their motivation to learn it. The students were 73 sixth graders and 85 eighth graders from a rural public school in the southeastern United States. It was hypothesized that the use of constructivist learning methods which involve analogies, particularly analogies enhanced by students' written elaborations or students' drawings, would improve students' text learning and their motivation to learn. Text learning was measured by conceptual understanding, recall, and recognition. Motivation to learn was measured by self-reported activity flow experience. Data were examined through univariate analyses of covariance, content analysis, and Pearson correlations for both immediate and delayed measures. The results indicated that the sixth graders in the analogy condition had significantly higher recall than the sixth graders in the control condition. Based on prior text reading experiences, the sixth graders reported higher levels of flow than the eighth graders. The sixth graders and eighth graders reported equivalent levels of flow in the analogy and control conditions immediately after the actual text study. In the other conditions, where the students were asked to elaborate or draw, the sixth graders reported lower levels of flow suggesting that elaborating and drawing perhaps taxed their limited abilities. Future research should provide higher levels of scaffolding and techniques to encourage the most effective use of written elaboration and drawing when using analogies to learn from science text.

  18. Glucose-6-phosphatase deficiency

    OpenAIRE

    Labrune Philippe; Gajdos Vincent; Eberschweiler Pascale; Hubert-Buron Aurélie; Petit François; Vianey-Saban Christine; Boudjemline Alix; Piraud Monique; Froissart Roseline

    2011-01-01

    Abstract Glucose-6-phosphatase deficiency (G6P deficiency), or glycogen storage disease type I (GSDI), is a group of inherited metabolic diseases, including types Ia and Ib, characterized by poor tolerance to fasting, growth retardation and hepatomegaly resulting from accumulation of glycogen and fat in the liver. Prevalence is unknown and annual incidence is around 1/100,000 births. GSDIa is the more frequent type, representing about 80% of GSDI patients. The disease commonly manifests, betw...

  19. Analog video to ARINC 818

    Science.gov (United States)

    Grunwald, Paul

    2015-05-01

    Many commercial and military aircraft still use analog video, such as RS-170, RS-343, or STANEG 3350. Though the individual digital components many be inexpensive, the cost to certify and retrofit an entire aircraft fleet may be prohibitively expensive. A partial or incremental upgrade program where analog cameras remain in use but data is converted and processed digitally can be an attractive option. This paper describes Great River Technology's experience in converting multiple channels of RS-170 and multiplexing them through a concentrator to put them onto a single fiber or cable. The paper will also discuss alternative architectures and how ARINC 818 can be utilized with legacy systems.

  20. Dynamics of water molecules in glucose solutions

    International Nuclear Information System (INIS)

    The effects of the solution of glucose molecules on the dynamics of solvent water have been studied by quasielastic neutron scattering (QENS) measurements on solutions of selectively deuterated glucose in natural water. The data are fitted to two Lorentzians ascribed to pure translational and mixed translational and rotational character, respectively. The addition of the glucose to the water causes a substantial slowing down, by a factor 10 for the translational diffusion and 3-4 for the rotational motion at the highest concentration studied, 1:11 C6H12O6:H2O. The values obtained for water diffusion constants are consistent with previous QENS and NMR experiments on monosaccharide solutions but an order of magnitude higher than those derived from a recent molecular dynamics simulation.

  1. Hepatic glucose sensing is required to preserve ? cell glucose competence.

    Science.gov (United States)

    Seyer, Pascal; Vallois, David; Poitry-Yamate, Carole; Schütz, Frédéric; Metref, Salima; Tarussio, David; Maechler, Pierre; Staels, Bart; Lanz, Bernard; Grueter, Rolf; Decaris, Julie; Turner, Scott; da Costa, Anabela; Preitner, Frédéric; Minehira, Kaori; Foretz, Marc; Thorens, Bernard

    2013-04-01

    Liver glucose metabolism plays a central role in glucose homeostasis and may also regulate feeding and energy expenditure. Here we assessed the impact of glucose transporter 2 (Glut2) gene inactivation in adult mouse liver (LG2KO mice). Loss of Glut2 suppressed hepatic glucose uptake but not glucose output. In the fasted state, expression of carbohydrate-responsive element-binding protein (ChREBP) and its glycolytic and lipogenic target genes was abnormally elevated. Feeding, energy expenditure, and insulin sensitivity were identical in LG2KO and control mice. Glucose tolerance was initially normal after Glut2 inactivation, but LG2KO mice exhibited progressive impairment of glucose-stimulated insulin secretion even though ? cell mass and insulin content remained normal. Liver transcript profiling revealed a coordinated downregulation of cholesterol biosynthesis genes in LG2KO mice that was associated with reduced hepatic cholesterol in fasted mice and reduced bile acids (BAs) in feces, with a similar trend in plasma. We showed that chronic BAs or farnesoid X receptor (FXR) agonist treatment of primary islets increases glucose-stimulated insulin secretion, an effect not seen in islets from Fxr(-/-) mice. Collectively, our data show that glucose sensing by the liver controls ? cell glucose competence and suggest BAs as a potential mechanistic link. PMID:23549084

  2. Análise de diferentes medidas antropométricas na identificação de síndrome metabólica, com ou sem alteração do metabolismo glicídico Analysis of several anthropometric measurements for the identification of metabolic syndrome, with or without disturbance of glucose metabolism

    Directory of Open Access Journals (Sweden)

    Natália Pereira da Rocha

    2010-10-01

    Full Text Available OBJETIVO: Este estudo comparou parâmetros antropométricos e de resistência à insulina de indivíduos sem e com síndrome metabólica (SM, subestratificados pela presença de anormalidades glicêmicas. SUJEITOS E MÉTODOS: Foram incluídos 454 indivíduos (66% mulheres, 54% brancos, sendo 155 alocados para o grupo 1 (sem SM, sem anormalidade glicêmica, 32 para o grupo 2 (sem SM, com anormalidade glicêmica, 104 no grupo 3 (com SM, sem anormalidade glicêmica e 163 no grupo 4 (com SM e anormalidade glicêmica. Os grupos foram comparados por ANOVA. RESULTADOS: Os grupos com SM (3 e 4 apresentaram os piores perfis antropométrico e lipídico; no grupo 2, apesar de glicemias significantemente mais elevadas, as médias das variáveis antropométricas e lipídicas não diferiram do grupo 1. Os maiores valores médios de HOMA-IR foram encontrados nos grupos com SM, enquanto o grupo 2 apresentou o menor HOMA-?. A trigliceridemia foi a variável metabólica com coeficientes de correlação mais elevados com a antropometria. Porém, as correlações mais fortes foram da circunferência da cintura (r = 0,503 e da razão cintura-altura (r = 0,513 com o HOMA-IR (p OBJECTIVE: This study compared anthropometric measurements and insulin resistance indexes of individuals with or without metabolic syndrome (MS, stratified by the presence of glycemic abnormalities. SUBJECTS AND METHODS: 454 individuals (66% women, 54% Caucasians were included, being 155 allocated to group 1 (without MS, without glycemic abnormality, 32 to group 2 (without MS, with glycemic abnormality, 104 to group 3 (with MS, without glycemic abnormality, and 163 to group 4 (with MS, with glycemic abnormality. Groups were compared by ANOVA. RESULTS: Those with MS (3 e 4 showed the worst anthropometric and lipid profiles; in group 2, despite higher plasma glucose levels, the mean values of anthropometric variables and lipids did not differ from group 1. The highest mean values of HOMA-IR were found in the groups with MS, while group 2 showed the lowest HOMA-?. Triglyceride was the metabolic variable with the highest correlation coefficients with anthropometry. However, the strongest correlations were those of waist circumference (r = 0.503 and waist-to-height ratio (r = 0.513 with HOMA-IR (p < 0.01. CONCLUSION: Our findings indicate that, in a sample of the Brazilian population, any anthropometric measure identifies individuals with MS, but such measurements seem to be unable to differentiate those with glycemic disturbance. We reinforce the strongest relationship of measures of central adiposity with insulin resistance, suggesting utility for the waist-to-height. An autoimmune component may be contributing to the deterioration of glucose metabolism of individuals from group 2.

  3. Geometrical Analogies in Mathematics Lessons

    Science.gov (United States)

    Eid, Wolfram

    2007-01-01

    A typical form of thinking to approach problem solutions humanly is thinking in analogous structures. Therefore school, especially mathematical lessons should help to form and to develop corresponding heuristic abilities of the pupils. In the contribution, a summary of possibilities of mathematics lessons regarding this shall particularly be…

  4. Analog Input Data Acquisition Software

    Science.gov (United States)

    Arens, Ellen

    2009-01-01

    DAQ Master Software allows users to easily set up a system to monitor up to five analog input channels and save the data after acquisition. This program was written in LabVIEW 8.0, and requires the LabVIEW runtime engine 8.0 to run the executable.

  5. Electrical analog to projectile motion

    Science.gov (United States)

    Vondracek, Mark

    1998-04-01

    This article describes an electrical analog to traditional projectile problems given in high school and introductory college classes. It also discusses the importance of stressing the understanding of physical laws and principles to students, and that the physics behind a problem is more important than being able to memorize and use various equations.

  6. Components of Geometric Analogy Solution.

    Science.gov (United States)

    Mulholland, Timothy M.; And Others

    1980-01-01

    Adults' geometric analogy solution was investigated as a function of systematic variations in the information structure of items. Latency data from verification of true and false items were recorded. A model incorporating assumptions about the form of item representation, working memory factors, and processing components and strategies was…

  7. Paper Analogies Enhance Biology Teaching.

    Science.gov (United States)

    Stencel, John E.

    1997-01-01

    Describes how to use paper analogies as models to illustrate various concepts in biology, human anatomy, and physiology classes. Models include biochemical paper models, protein papergrams, a paper model of early brain development, and a 3-D paper model of a eukaryotic cell. (AIM)

  8. Analysis of Continuous Glucose Monitoring in Pregnant Women With Diabetes

    DEFF Research Database (Denmark)

    Law, Graham R; Ellison, George T H; Secher, Anna L; Damm, Peter; Mathiesen, Elisabeth R; Temple, Rosemary; Murphy, Helen R; Scott, Eleanor M

    2015-01-01

    OBJECTIVE: Continuous glucose monitoring (CGM) is increasingly used to assess glucose control in diabetes. The objective was to examine how analysis of glucose data might improve our understanding of the role temporal glucose variation has on large-for-gestational-age (LGA) infants born to women...... diabetes (n = 89) and type 2 diabetes (n = 28) who used repeated CGM during pregnancy were recruited from secondary care multidisciplinary obstetric clinics for diabetes in the U.K. and Denmark. LGA was defined as birth weight ?90th percentile adjusted for sex and gestational age. RESULTS: A total of 54 of...... with diabetes. RESEARCH DESIGN AND METHODS: Functional data analysis (FDA) was applied to 1.68 million glucose measurements from 759 measurement episodes, obtained from two previously published randomized controlled trials of CGM in pregnant women with diabetes. A total of 117 women with type 1...

  9. Analogies of form between chunks in japanese are massive and far from being misleading

    OpenAIRE

    Lepage, Yves; Migeot, Julien; Guillerm, Erwan

    2007-01-01

    This paper relates to the assessment of the argument of the poverty of the stimulus in that we measure the number of true proportional analogies between chunks in a language with case markers, Japanese. On a bicorpus of 20,000 sentences, we show that at least 96% of the analogies of form between chunks are also analogies of meaning, thus reporting the presence of at least two million true analogies between chunks in this corpus. As the number of analogies between chunks grows nearly quadratic...

  10. Copper-incorporated SBA-15 with peroxidase-like activity and its application for colorimetric detection of glucose in human serum.

    Science.gov (United States)

    Mu, Jianshuai; He, Yun; Wang, Yan

    2016-02-01

    The copper incorporated SBA-15 (Cu-SBA-15) materials with different amount of Cu in framework were synthesized, and the products were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM) and N2 adsorption/desorption. The Cu contents incorporated into the framework of SBA-15 were measured by inductively coupling plasma atomic emission spectrometer (ICP-AES). Cu-SBA-15 samples were found to exhibit the peroxidase-like activity, similar to the natural peroxidase. The effect of various parameters such as the content of Cu incorporated, pH and temperature on the peroxidase-like activity was studied. Based on the peroxidase-like activity, the Cu-SBA-15 was applied to the determination of H2O2. The linear range for detecting H2O2 was from 0.8 to 60mM with a detection limit of 3.7µM. Coupled with glucose oxidase, the Cu-SBA-15 was successfully used for the determination of glucose with the linear range of 2-80mM and a detection limit of 5.4µM. The determination of glucose in human serum showed high accuracy, good reproducibility, as well as high selectivity against uric acid, ascorbic acid, dopamine and glucose analogs including fructose, maltose and lactose. PMID:26653419

  11. Assessment of insulin action in insulin-dependent diabetes mellitus using [6(14)C]glucose, [3(3)H]glucose, and [2(3)H]glucose. Differences in the apparent pattern of insulin resistance depending on the isotope used

    International Nuclear Information System (INIS)

    To determine whether [2(3)H], [3(3)H], and [6(14)C]glucose provide an equivalent assessment of glucose turnover in insulin-dependent diabetes mellitus (IDDM) and nondiabetic man, glucose utilization rates were measured using a simultaneous infusion of these isotopes before and during hyperinsulinemic euglycemic clamps. In the nondiabetic subjects, glucose turnover rates determined with [6(14)C]glucose during insulin infusion were lower (P less than 0.02) than those determined with [2(3)H]glucose and higher (P less than 0.01) than those determined with [3(3)H]glucose. In IDDM, glucose turnover rates measured with [6(14)C]glucose during insulin infusion were lower (P less than 0.05) than those determined with [2(3)H]glucose, but were not different from those determined with [3(3)H]glucose. All three isotopes indicated the presence of insulin resistance. However, using [3(3)H]glucose led to the erroneous conclusion that glucose utilization was not significantly decreased at high insulin concentrations in the diabetic patients. [6(14)C] and [3(3)H]glucose but not [2(3)H]glucose indicated impairment in insulin-induced suppression of glucose production. These results indicate that tritiated isotopes do not necessarily equally reflect the pattern of glucose metabolism in diabetic and nondiabetic man

  12. Proximal small intestinal mucosal injury. Maintenance of glucose and glucose polymer absorption, attenuation of disaccharide absorption.

    Science.gov (United States)

    Palacios, M; Madariaga, H; Heitlinger, L; Lee, P C; Lebenthal, E

    1989-03-01

    The effect of chronic intragastric infusion of hypertonic mannitol on small intestinal mucosal structure and function was studied in adult rats. Animals were gavage-fed 20% mannitol (1300 mosm) at a dose of 5 ml/100 g body weight daily for seven days. Control animals were gavage-fed tap water on the same schedule. On day 8, the animals were anesthetized, the duodenum cannulated, and a test sugar (glucose, glucose polymer, lactose, sucrose, or maltose) was infused at a dose of 0.5 g/kg body weight in 2.5 ml distilled water over less than 1 min. Portal vein glucose was measured at 30-min intervals from 0 to 120 min. Mannitol treatment resulted in histologic and biochemical alterations (reduced lactase, sucrase, maltase) limited to the proximal small intestine compared to the control group. The absorption of glucose and glucose polymers was similar in mannitol-treated and control animals. In contrast, digestion and absorption of lactose, sucrose, and maltose was significantly diminished in mannitol-treated animals when compared to controls. No changes in permeability to polyethylene glycol 4000 or Na+-coupled glucose transport were observed in mannitol-treated animals compared to controls. These data suggest that when the intestinal mucosa is exposed to hyperosmolar loads that the digestive capacity for disaccharides is suppressed more than its glucose absorptive capacities. Furthermore, glucose oligomers may be more readily digested and absorbed than disaccharides, in this setting, due, in part, to the proximal injury and less pronounced proximal-distal gradient for glucoamylase than other brush-border carbohydrases.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2493365

  13. PHYSICO-CHEMICAL PROPERTIES OF MAGNESIUM IONIC LIQUID ANALOGOUS

    Directory of Open Access Journals (Sweden)

    Huaiyou Wang

    2012-01-01

    Full Text Available In this paper, the solubility of Choline chloride (ChCl in ethylene glycol (EG was measured by isothermal method in the temperature range between 0°C and 120°C. The solubility of MgCl2 in saturated ChCl-EG mixture was measured by isothermal method at 20°C, 50°C and 70°C, respectively. Ionic liquid analogous containing MgCl2 was prepared based on the measured solubility data. The structure of the ionic liquid analogous is preliminarily investigated by Fourier transform infrared spectroscopy. The physical and electrochemical properties of the ionic liquid such as viscosity, conductivity, molar conductivity and density were measured as function of temperature and compositions. It was found that magnesium ionic liquid analogous was highly conducting and low viscosity. The ChCl and MgCl2 had a great effect on the studied properties.

  14. PHYSICO-CHEMICAL PROPERTIES OF MAGNESIUM IONIC LIQUID ANALOGOUS

    Scientific Electronic Library Online (English)

    Huaiyou, Wang; Yongzhong, Jia; Xiaohua, Wang; Jun, Ma; Yan, Jing.

    Full Text Available In this paper, the solubility of Choline chloride (ChCl) in ethylene glycol (EG) was measured by isothermal method in the temperature range between 0°C and 120°C. The solubility of MgCl2 in saturated ChCl-EG mixture was measured by isothermal method at 20°C, 50°C and 70°C, respectively. Ionic liquid [...] analogous containing MgCl2 was prepared based on the measured solubility data. The structure of the ionic liquid analogous is preliminarily investigated by Fourier transform infrared spectroscopy. The physical and electrochemical properties of the ionic liquid such as viscosity, conductivity, molar conductivity and density were measured as function of temperature and compositions. It was found that magnesium ionic liquid analogous was highly conducting and low viscosity. The ChCl and MgCl2 had a great effect on the studied properties.

  15. Alternansucrase acceptor reactions with D-tagatose and L-glucose.

    Science.gov (United States)

    Côté, Gregory L; Dunlap, Christopher A; Appell, Michael; Momany, Frank A

    2005-02-01

    Alternansucrase (EC 2.4.1.140) is a d-glucansucrase that synthesizes an alternating alpha-(1-->3), (1-->6)-linked d-glucan from sucrose. It also synthesizes oligosaccharides via d-glucopyranosyl transfer to various acceptor sugars. Two of the more efficient monosaccharide acceptors are D-tagatose and L-glucose. In the presence of d-tagatose, alternansucrase produced the disaccharide alpha-d-glucopyranosyl-(1-->1)-beta-D-tagatopyranose via glucosyl transfer. This disaccharide is analogous to trehalulose. We were unable to isolate a disaccharide product from L-glucose, but the trisaccharide alpha-D-glucopyranosyl-(1-->6)-alpha-d-glucopyranosyl-(1-->4)-l-glucose was isolated and identified. This is analogous to panose, one of the structural units of pullulan, in which the reducing-end D-glucose residue has been replaced by its L-enantiomer. The putative L-glucose disaccharide product, produced by glucoamylase hydrolysis of the trisaccharide, was found to be an acceptor for alternansucrase. The disaccharide, alpha-D-glucopyranosyl-(1-->4)-L-glucose, was a better acceptor than maltose, previously the best known acceptor for alternansucrase. A structure comparison of alpha-D-glucopyranosyl-(1-->4)-L-glucose and maltose was performed through computer modeling to identify common features, which may be important in acceptor affinity by alternansucrase. PMID:15639245

  16. READ - Remote Analog ASIC Design System

    OpenAIRE

    Auer, Michael E.; Danilo G. Zutin

    2006-01-01

    The scope of this work is to present a solution to implement a remote electronic laboratory for testing and designing analog ASICs (ispPAC10). The application allows users to create circuit schematics, upload the design to the device and perform measurements. The software used for designing circuits is the PAC-Designer and it runs on a Citrix server. The signals are generated and the responses are acquired by a data acquisition board controlled by LabView. The virtual instruments interact wi...

  17. The proton spin crisis: an electroweak analogy

    International Nuclear Information System (INIS)

    We pose a problem analogous to the spin crisis within the electroweak theory. It is shown that the forward matrix elements of j?B, the baryonic current, do not only measure the generally understood baryon number but also include a helicity dependent W-boson piece due to the anomaly. The anomalous contribution is explicitly calculated for the W-boson and the electron. We also demonstrate the correct procedure to extract the anomalous W-boson contribution to the forward matrix element of j+B. ((orig.))

  18. Whole body glucose kinetics in type I diabetes studied with [6,6-2H] and [U-13C]-glucose and the artificial B-cell

    International Nuclear Information System (INIS)

    Dynamic aspects of whole body glucose metabolism were assessed in ten young adult insulin-dependent (type I) diabetic men. Using a primed, continuous intravenous infusion of [6,6-2H]glucose and [U-13C]glucose, endogenous production, tissue uptake, carbon recycling, and oxidation of glucose were measured in the postabsorptive state. These studies were undertaken after blood glucose had been maintained overnight at 5.9 +/- 0.4 mmol/L (n = 10), and on another night at 10.5 +/- 0.4 mmol/L (n = 4) or 15.2 +/- 0.6 mmol/L (n = 6). In the normoglycemic state, endogenous glucose production averaged 2.15 +/- 0.13 mg x kg-1 x min-1. This value, as well as the rate of glucose carbon recycling (0.16 +/- 0.04 mg x kg-1 x min-1) and glucose oxidation (1.52 +/- 0.16 mg x kg-1 x min-1) are comparable to those found in nondiabetic controls. In the hyperglycemic states at 10 or 15 mmol/L, endogenous glucose production was increased by 11% (P less than .01) and 60% (P less than .01) compared to the normoglycemic states, respectively. Glucose carbon recycling contributed only a small percentage to this variation in glucose production (15% at the 15 mmol/L glucose level). This suggests that if gluconeogenesis participates in the increased glucose output, it is not dependent on a greater systemic supply of three-carbon precursors. The increased rate of glucose production in the hyperglycemic state was quantitatively offset by a rise in urinary glucose excretion. Glucose tissue uptake, as well as glucose oxidation, did not vary between normoglycemic and hyperglycemic states

  19. Entry rates and recycling of glucose in buffalo calves fed on urea molasses liquid diet

    International Nuclear Information System (INIS)

    Entry rates of glucose have been measured in buffalo calves by using a dual-isotope dilution method based on continuous infusion of (U-14C)D-glucose and (6-3H)D-glucose into the blood at a precise controlled rate for 540 min. After 5 h a plateau was obtained in the specific radioactivity of the plasma glucose from which glucose synthesis and entry rates were calculated. The average entry rates of glucose were 112 and 145 mg/min measured by 14C and 3H labelled glucose respectively. About 23 percent of the glucose carbon was recycled in the pool. The average recycling rate was 33 mg/min. (author)

  20. Analog circuit design art, science and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    This book is far more than just another tutorial or reference guide - it's a tour through the world of analog design, combining theory and applications with the philosophies behind the design process. Readers will learn how leading analog circuit designers approach problems and how they think about solutions to those problems. They'll also learn about the `analog way' - a broad, flexible method of thinking about analog design tasks.A comprehensive and useful guide to analog theory and applications. Covers visualizing the operation of analog circuits. Looks at how to rap

  1. Vascular effects of rapid-acting insulin analogs in the diabetic patient: a review

    Directory of Open Access Journals (Sweden)

    Steve Fordan

    2009-02-01

    Full Text Available Steve Fordan, Philip RaskinDepartment of Medicine, Division, of Endocrinology, University of Texas, Southwestern Medical Center, Dallas, TX, USAAbstract: The insulin analogs lispro, aspart, and glulisine are the only commercially available rapid-acting insulins to treat diabetes. We review the evidence for treating hyperglycemia, using insulin, and specifically using rapid-acting analogs in diabetic individuals, on the prevention of vascular events. We review the beneficial effects of insulin on the vascular system, which include vasodilation and anti-inflammatory actions. The effects of treating hyperglycemia and intensive blood glucose control on vascular outcomes are reviewed.Keywords: lispro, aspart, glulisine, nitric oxide synthetase, nuclear factor kappa B 

  2. Plasma glucose levels and flight

    OpenAIRE

    Tomei G; Loreti B; Rosati MV; Tomao E; Sinibaldi F; De Sio S; Casale T; Pimpinella B; Di Pastena C; Tomei F; Stansfeld S; Andrè JC; Caciari T

    2013-01-01

    Background: Noise is able to exert many adverse health effects, ranging from damages on various organs and systems to changes in biochemical and humoral markers. In literature, the effects of chronic exposure to noise on blood glucose levels have been reported, although these results are conflicting: some authors reported hyperglycaemia, others hypoglycaemia and many others recorded no changes in blood glucose levels. Objectives: Considering that the plasma glucose levels are not used as a b...

  3. Glucose repression in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Kayikci, Omur; Nielsen, Jens

    2015-01-01

    Glucose is the primary source of energy for the budding yeast Saccharomyces cerevisiae. Although yeast cells can utilize a wide range of carbon sources, presence of glucose suppresses molecular activities involved in the use of alternate carbon sources as well as it represses respiration and gluconeogenesis. This dominant effect of glucose on yeast carbon metabolism is coordinated by several signaling and metabolic interactions that mainly regulate transcriptional activity but are also effective...

  4. A Unified Potentiostat for Electrochemical Glucose Sensors

    Directory of Open Access Journals (Sweden)

    Yeong-Seuk Kim

    2013-10-01

    Full Text Available A unified potentiostat circuit for both O2- and H2O2- based electrochemical glucose sensors was proposed and itsfunction was verified by circuit simulations and measurement results of a fabricated chip. This circuit consisted ofan operational amplifier, a comparator and current mirrors. The proposed circuit was fabricated with a 0.13 ? thickoxide CMOS process and an active area of 360 ? × 100 ?. The measurements revealed an input operation range from0.5 V to 1.6 V in the H2O2- based bio-sensor and from 1.7 V to 2.6 V in the O2- based bio-sensor with a supply voltage of 3.3V. The evaluation results showed that the proposed potentiostat circuit is suitable for measuring the electrochemicalcell currents of both O2- and H2O2- based glucose sensors.

  5. Classical Analog to Entanglement Reversibility

    Science.gov (United States)

    Chitambar, Eric; Fortescue, Ben; Hsieh, Min-Hsiu

    2015-08-01

    In this Letter we study the problem of secrecy reversibility. This asks when two honest parties can distill secret bits from some tripartite distribution pX Y Z and transform secret bits back into pX Y Z at equal rates using local operation and public communication. This is the classical analog to the well-studied problem of reversibly concentrating and diluting entanglement in a quantum state. We identify the structure of distributions possessing reversible secrecy when one of the honest parties holds a binary distribution, and it is possible that all reversible distributions have this form. These distributions are more general than what is obtained by simply constructing a classical analog to the family of quantum states known to have reversible entanglement. An indispensable tool used in our analysis is a conditional form of the Gács-Körner common information.

  6. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J. M

    2013-01-01

    This textbook is appropriate for use in graduate-level curricula in analog to digital conversion, as well as for practicing engineers in need of a state-of-the-art reference on data converters.  It discusses various analog-to-digital conversion principles, including sampling, quantization, reference generation, nyquist architectures and sigma-delta modulation.  This book presents an overview of the state-of-the-art in this field and focuses on issues of optimizing accuracy and speed, while reducing the power level. This new, second edition emphasizes novel calibration concepts, the specific requirements of new systems, the consequences of 45-nm technology and the need for a more statistical approach to accuracy.  Pedagogical enhancements to this edition include more than twice the exercises available in the first edition, solved examples to introduce all key, new concepts and warnings, remarks and hints, from a practitioner’s perspective, wherever appropriate.  Considerable background information and pr...

  7. Quality assessment of patients’ self-monitoring of blood glucose in community pharmacies

    OpenAIRE

    Kjome RL; Granas AG; Nerhus K; Sandberg S

    2010-01-01

    Objective: To evaluate diabetes patients’ selfmonitoring of blood glucose using a community pharmacy-based quality assurance procedure, to investigate whether the procedure improved the quality of the patient performance of self monitoring of blood glucose, and to examine the opinions of the patients taking part in the study. Methods: The results of patient blood glucose measurements were compared to the results obtained with HemoCue Glucose 201+ by pharmacy empl...

  8. Factors Associated with Increases in Glucose Levels in the Perioperative Period in Non-Diabetic Patients

    OpenAIRE

    Manasee Sant; Alejandro F. Castro III; Catherine Schoenberg; Vasanti Tilak

    2013-01-01

    Background: Blood glucose levels are elevated during the perioperative period as a result of the neuro-endocrine response to the stress of surgery. In nondiabetic patients, blood glucose levels are not a part of routine preoperative testing nor are they monitored during surgery or in the post anesthesia care unit (PACU). We measured blood glucose levels in nondiabetic patients during the perioperative period to identify how many patients had high glucose levels and what factors were associat...

  9. Optimisation of cancer therapy : glucose antimetabolites as adjuvants in radiotherapy

    International Nuclear Information System (INIS)

    Inhibiting the repair of radiation damage in the neoplastic cells and thus differentially increasing radiation damage can be one of the ways to improve efficiency of radiotherapy of cancer. The glucose antimetabolite 2-deoxy-D-glucose (2-DG) which is known to inhibit glycolysis and ATP production in different cell systems, has been studied as to its effects on energy supply and repair of radiation damage in wild type yeast cells which are analogous to normal cells, and in respirator-deficient (RD) mutants which are analogous to hypoxic tumour cells. Results indicate that : (1) 2-DG/glucose in molar cencentration ratio of 1 completely inhibits the repair of potentially lethal X-radiation damage in RD mutants, (2) 2-DG enhances repair of sublethal radiation damage in wild-type yeast cells, (3) 2-DG induces a sharp fall in ATP level in RD-mutants as compared to that in wild type cells, (4) 2-DG inhibits repair of potentially lethal X-radiation damage in Ehrlich ascites tumour cells, (5) 2-DG induces greater cell loss from the hypoxic as well as euoxic tumour cell population of sarcoma tumour-180 in mice, and (6) 2-DG increases the survival of normal mice when given whole-body gamma irradiaition. These results, therefore, show that 2-DG may differentially inhibit the repair process in tumours while enhancing repair in normal tissues. (M.G.B.)

  10. The Analogous City, The Map

    OpenAIRE

    Rodighiero, Dario

    2015-01-01

    This new publication of The Analogous City, an artwork produced by Aldo Rossi, Eraldo Consolascio, Bruno Reichlin and Fabio Reinhart for the Venice Biennale of Architecture in 1976, is part of a museographic installation for the exhibition Aldo Rossi - The Window of the Poet at the Bonnefanten Museum in Maastricht. To gauge and explore this seminal work, Archizoom relied on Dario Rodighiero, candidate on the Doctoral Programme for Architecture and Sciences of the Cities, and designer at the D...

  11. Evolutionary synthesis of analog networks

    OpenAIRE

    Mattiussi, Claudio

    2005-01-01

    The significant increase in the available computational power that took place in recent decades has been accompanied by a growing interest in the application of the evolutionary approach to the synthesis of many kinds of systems and, in particular, to the synthesis of systems like analog electronic circuits, neural networks, and, more generally, autonomous systems, for which no satisfying systematic and general design methodology has been found to date. Despite some interesting results in the...

  12. EMC of analog integrated circuits

    CERN Document Server

    Redoute, Jean-Michel

    2009-01-01

    Environmental electromagnetic pollution has drastically increased over the last decades. The omnipresence of communication systems, various electronic appliances and the use of ever increasing frequencies, all contribute to a noisy electromagnetic environment which acts detrimentally on sensitive electronic equipment. Integrated circuits must be able to operate satisfactorily while cohabiting harmoniously in the same appliance, and not generate intolerable levels of electromagnetic emission, while maintaining a sound immunity to potential electromagnetic disturbances: analog integrated circuit

  13. Glucose metabolism in ischemic myocardium

    International Nuclear Information System (INIS)

    We determined the myocardial metabolic rate for glucose (MMRGlc) in the ischemic or infarcted myocardium using 18-F-fluorodeoxyglucose (18-FDG) with positron emission tomography (PET), and studied energy metabolism in the ischemic myocardium. In some cases, we compared glucose metabolism images by 18-FDG with myocardial blood flow images using 15-oxygen water. Two normal subjects, seven patients with myocardial infarction and four patients with angina pectoris were studied. Coronary angiography was performed within two weeks before or after the PET study to detect ischemic areas. PET studies were performed for patients who did not eat for 5 to 6 hours after breakfast. Cannulation was performed in the pedal artery to measure free fatty acid, blood sugar, and insulin. After recording the transmission scan for subsequent correction of photon attenuation, blood pool images were recorded for two min. after the inhalation of carbon monoxide (oxygen-15) which labeled the red blood cells in vivo. After 20 min., oxygen-15 water (15 to 20 mCi) was injected for dynamic scans, and flow images were obtained. Thirty min. after this procedure, 18-FDG (5 to 6 mCi) was injected, and 60 min later, a static scan was performed and glucose metabolism images were obtained. Arterial blood sampling for the time activity curve of the tracer was performed at the same time. According to the method of Phelps et al, MMRGlc was calculated in each of the region of interest (ROI) which was located in the left ventricular wall. MMRGlc obtained from each ROI was 0 to 17 mg/100 ml/min. In normal subjects MMRGlc was 0.4 to 7.3 mg/100 ml/min. In patients with myocardial infarction, it ranged from 3 to 5 mg/100 ml/min in the infarcted lesion. In patients with angina pectoris and subendocardial infarction, MMRGlc was 7 to 17 mg/100 ml/min in the ischemic lesion. In this lesion, myocardial blood flow was relatively low by oxygen-15 imagings (so-called mismatch). (J.P.N.)

  14. Determination of serum glucose by isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    An accurate and precise method for determination of serum glucose by isotope dilution mass spectrometry was studied for use in establishing the accuracy of glucose methods in clinical laboratories. After adding uniformly labeled [13C6] glucose to the serum, glucose was separated from the serum matrix and converted into ?-D-glucofranose cyclic 1,2 : 3,5-bis(n-butylboronate)-6-acetate (glucose-BBA). Measurements were performed with combined capillary gas chromatography-mass spectrometry. The ratios of the peak areas at m/z 297 and 303 for samples and calibration mixtures were used for quantification. Analytical results of the SRM serum showed satisfactory agreement with the certified value and a coefficient of variation of the replicates was within 0.5% for all the serum samples tested. (author)

  15. Determination of serum glucose by isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    An accurate and precise method for the determination of serum glucose by isotope dilution mass spectrometry was studied for use in establishing the accuracy of glucose methods in clinical laboratories. After adding uniformly labeled [13C6] glucose to the serum, glucose was separated from the serum matrix and converted into ?-D-glucofranose cyclic 1,2:3,5-bis(n-butylboronate)-6-acetate (glucose-BBA). Measurements were performed with combined capillary gas chromatography-mass spectrometry. The ratios of the peak areas at m/z 297 and 303 for samples and the calibration mixtures were used for quantification. Analytical results of the SRM serum showed satisfactory agreement with the certified value and the relative standard deviation of the replicates was within 0.5 % for all of the serum samples tested. (author)

  16. Regional differences in adipocyte lactate production from glucose

    International Nuclear Information System (INIS)

    Having shown that lactate is an important product of glucose metabolism by rat epididymal adipocytes, the authors investigated possible regional differences in adipocyte lactate production and the role of the animals' nutritional state and stage of development. [U-14C]glucose metabolism, lactate production, and response to insulin were measured in fat cells isolated from four adipose regions from young lean and older fatter rats, killed either in the fed state or after fasting for 48 h. In the absence of insulin, mesenteric fat cells from either age group metabolized significantly more glucose per cell and converted more glucose to lactate than cells from other depots, regardless of nutritional state. Adipocytes from fasted lean rats showed a significant increase in the relative glucose conversion to lactate in all depots when compared with cells from fed lean rats. Fasting of older fatter rats, however, had limited effects on the relative adipocyte glucose conversion to lactate since lactate production was already high. Mesenteric fat cells had the lowest relative response to insulin, possibly due to the high basal rate of glucose metabolism. These findings indicate that differences exist among adipose regions in the rates of glucose metabolism, lactate production and response to insulin. The anatomical location of the mesenteric adipose depot, coupled with a high metabolic rate and blood perfusion, suggests that mesenteric adipocytes may provide a unique and more direct contribution of metabolic substrates for hepatic metabolism than adipocytes from other depots

  17. A Study on the Glucose and Immunoreactive Insulin Response during Oral Glucose Tolerance Test in Patients with Chronic Liver Diseases

    International Nuclear Information System (INIS)

    The blood glucose and plasma immunoreactive insulin (IRI) levels were measured during aral glucose tolerance test in 7 healthy subjects and 6 patients with chronic liver diseases. The glucose tolerance was impaired in 5 of the 6 patients and normal in I. Plasma IRI responses were markedly increased and delayed in all patients, suggesting endogenous insulin resistance. Patients with more glucose intolerance showed less increase in plasma IRI than the group with less intolerance. lt is suggested that some insulin antagonists may decrease the peripheral insulin sensitivity and stimulate compensatory hyperactivity of pancreatic islets. If the compensatory hyperactivity is inadequate due to gemetic predisposition to diabetes mellitus or exhaustion of ?-cells of pancreatic islets, the glucose intolerance and overt diabetes mellitus may ensue.

  18. An Integrated Glucose Sensor with an All-Solid-State Sodium Ion-Selective Electrode for a Minimally Invasive Glucose Monitoring System

    Directory of Open Access Journals (Sweden)

    Junko Kojima

    2015-06-01

    Full Text Available We developed a minimally invasive glucose monitoring system that uses a microneedle to permeate the skin surface and a small hydrogel to accumulate interstitial fluid glucose. The measurement of glucose and sodium ion levels in the hydrogel is required for estimating glucose levels in blood; therefore, we developed a small, enzyme-fixed glucose sensor with a high-selectivity, all-solid-state, sodium ion-selective electrode (ISE integrated into its design. The glucose sensor immobilized glucose oxidase showed a good correlation between the glucose levels in the hydrogels and the reference glucose levels (r > 0.99, and exhibited a good precision (coefficient of variation = 2.9%, 0.6 mg/dL. In the design of the sodium ISEs, we used the insertion material Na0.33MnO2 as the inner contact layer and DD16C5 exhibiting high Na+/K+ selectivity as the ionophore. The developed sodium ISE exhibited high selectivity (\\( \\log \\,k^{pot}_{Na,K} = -2.8\\ and good potential stability. The sodium ISE could measure 0.4 mM (10?3.4 M sodium ion levels in the hydrogels containing 268 mM (10?0.57 M KCl. The small integrated sensor (? < 10 mm detected glucose and sodium ions in hydrogels simultaneously within 1 min, and it exhibited sufficient performance for use as a minimally invasive glucose monitoring system.

  19. Methodology of effective glucose-specific signal extraction in complicated sample

    Science.gov (United States)

    Chen, Wenliang; Deng, Bin; Liu, Rong; Gu, Xiaoyu; Xu, Kexin

    2007-02-01

    In the area of noninvasive human blood glucose concentration detecting, it has always been a critical task to extract the glucose-specific signal from the highly overlapped and disturbed near-infrared spectrum. In this paper, the methodology of effective glucose-specific signal extraction in complicated non-scattering sample is studied. By analyzing the impact of water displacement upon dissolution of glucose, the relationship between glucose concentration and absorption coefficient of the sample is deduced. Then, the reference wavelength where the absorption coefficient is insensitive to the changes of glucose concentration is put forward theoretically. Accordingly, the validating experiments in aqueous glucose solutions are executed. Both the theoretical and laboratorial results show that the reference wavelength of glucose appears at 1525nm. Based on the reference wavelength, an effective method for extracting the glucose-specific signal in complicated non-scattering samples is proposed and the corresponding validating experiments are constructed with different glucose and albumin concentration. Two different methods, traditional and the novel reference wavelength method are used to extract glucose signal and the corresponding root mean square error of prediction are 19.86mg/dl and 9.87mg/dl respectively. The experiment results indicate that the reference wavelength method can effectively eliminate the influence of various noises on the glucose-specific signal extraction, and thus can remarkably improve the measuring precision in noninvasive near-infrared glucose detecting.

  20. Abnormal transient rise in hepatic glucose production after oral glucose in non-insulin-dependent diabetic subjects.

    Science.gov (United States)

    Thorburn, A; Litchfield, A; Fabris, S; Proietto, J

    1995-05-01

    A transient rise in hepatic glucose production (HGP) after an oral glucosa load has been reported in some insulin-resistant states such as in obese fa/fa Zucker rats. The aim of this study was to determine whether this rise in HGP also occurs in subjects with established non-insulin-dependent diabetes mellitus (NIDDM). Glucose kinetics were measured basally and during a double-label oral glucose tolerance test (OGTT) in 12 NIDDM subjects and 12 non-diabetic 'control' subjects. Twenty minutes after the glucose load, HGP had increased 73% above basal in the NIDDM subjects (7.29 +/- 0.52 to 12.58 +/- 1.86 mumol/kg/min, P < 0.02). A transient rise in glucagon (12 pg/ml above basal, P < 0.004) occurred at a similar time. In contrast, the control subjects showed no rise in HGP or plasma glucagon. HGP began to suppress 40-50 min after the OGTT in both the NIDDM and control subjects. A 27% increase in the rate of gut-derived glucose absorption was also observed in the NIDDM group, which could be the result of increased gut glucose absorption or decreased first pass extraction of glucose by the liver. Therefore, in agreement with data in animal models of NIDDM, a transient rise in HGP partly contributes to the hyperglycemia observed after an oral glucose load in NIDDM subjects. PMID:7587920

  1. Alginate cryogel based glucose biosensor

    Science.gov (United States)

    Fatoni, Amin; Windy Dwiasi, Dian; Hermawan, Dadan

    2016-02-01

    Cryogel is macroporous structure provides a large surface area for biomolecule immobilization. In this work, an alginate cryogel based biosensor was developed to detect glucose. The cryogel was prepared using alginate cross-linked by calcium chloride under sub-zero temperature. This porous structure was growth in a 100 μL micropipette tip with a glucose oxidase enzyme entrapped inside the cryogel. The glucose detection was based on the colour change of redox indicator, potassium permanganate, by the hydrogen peroxide resulted from the conversion of glucose. The result showed a porous structure of alginate cryogel with pores diameter of 20-50 μm. The developed glucose biosensor was showed a linear response in the glucose detection from 1.0 to 5.0 mM with a regression of y = 0.01x+0.02 and R2 of 0.994. Furthermore, the glucose biosensor was showed a high operational stability up to 10 times of uninterrupted glucose detections.

  2. Sex differences in glucose levels

    DEFF Research Database (Denmark)

    Faerch, K; Borch-Johnsen, Knut; Vaag, A; Jørgensen, Torben; Witte, D R

    2010-01-01

    We aimed to examine whether sex differences in fasting plasma glucose (FPG), 2 h post-OGTT plasma glucose (2hPG) and HbA(1c) could be explained by differences in body size and/or body composition between men and women in a general non-diabetic Danish population. Moreover, we aimed to study to what...

  3. Fluorescence studies with conformationally constrained tryptophan analogs: implications on the mechanisms of intramolecular quenching

    Science.gov (United States)

    Eftink, Maurice R.; Hu, D.; Jia, Y. W.

    1992-04-01

    The fluorescence properties of a set of tryptophan analogs, including several that are conformationally restricted, is reported. The conformationally restricted analogs include tetrahydrocarboline-3-carboxylic acid, 3-amino-3-carboxytetrahydrocarbazole, 3- aminotetrahydrocarbazole, and 3-carboxytetrahydrocarbazole. Steady-state and time-resolved measurements were made. The fluorescence decay of most of the conformationally restricted analogs is a bi-exponential. The fluorescence quantum yield and average lifetime of the restricted analogs is a bi-exponential. The fluorescence quantum yield and average lifetime of the restricted analogs are higher than the values for tryptophan and corresponding flexible tryptophan analogs. This indicates that the effective rate constant for intramolecular non- radiative (quenching) processes, knx, is smaller for the restricted tryptophan analogs than for the flexible analogs. For a series of flexible analogs, having a bifunctional side chain, there is synergism between the two functional groups (i.e., (alpha) -NH3+ and (alpha) -CO2- groups) in determining the effective knx. Potential mechanisms for intramolecular quenching mechanisms, which contribute to knx, include proton transfer from a side chain ammonium group to position four of the excited indole ring and charge transfer from the excited indole ring to a side chain acceptor group. By measuring the rate of photo-induced isotope exchange into position four of an analog's indole ring, we have estimated the contribution of proton transfer quenching to the total intramolecular quenching rate constant for several flexible tryptophan derivatives.

  4. Improvement in glucose biosensing response of electrochemically grown polypyrrole nanotubes by incorporating crosslinked glucose oxidase.

    Science.gov (United States)

    Palod, Pragya Agar; Singh, Vipul

    2015-10-01

    In this paper a novel enzymatic glucose biosensor has been reported in which platinum coated alumina membranes (Anodisc™s) have been employed as templates for the growth of polypyrrole (PPy) nanotube arrays using electrochemical polymerization. The PPy nanotube arrays were grown on Anodisc™s of pore diameter 100 nm using potentiostatic electropolymerization. In order to optimize the polymerization time, immobilization of glucose oxidase (GOx) was first performed using physical adsorption followed by measuring its biosensing response which was examined amperometrically for increasing concentrations of glucose. In order to further improve the sensing performance of the biosensor fabricated for optimum polymerization duration, enzyme immobilization was carried out using cross-linking with glutaraldehyde and bovine serum albumin (BSA). Approximately six fold enhancement in the sensitivity was observed in the fabricated electrodes. The biosensors also showed a wide range of linear operation (0.2-13 mM), limit of detection of 50 ?M glucose concentration, excellent selectivity for glucose, notable reliability for real sample detection and substantially improved shelf life. PMID:26117773

  5. Effects of intrapartum maternal glucose infusion on the normal fetus and newborn.

    Science.gov (United States)

    Mendiola, J; Grylack, L J; Scanlon, J W

    1982-01-01

    The effect of maternal intravenous glucose infusion on the newborn's glucose, insulin, and neurobehavioral performance was studied prospectively in 56 normal mother-newborn pairs. Maternal blood glucose levels at the time of delivery, umbilical venous blood glucose and insulin levels, and neonatal blood glucose levels were measured. Neurobehavioral assessment of the newborns was performed at 4 and 24 hours of life. The median value for total amount of glucose infused to the mother was 32.5 g, the median rate of glucose infusion was 8 g/h, and the median maternal blood glucose concentration at delivery was 110 mg/dl. Median umbilical venous blood glucose concentrations were 104 mg/dl and median insulin concentration was 15 microunits/ml. Six babies were hypoglycemic at 1 hour of age. Umbilical venous glucose and insulin levels correlated significantly (p less than 0.001) with the rate of glucose infusion to the mother and her blood glucose level. The incidence of neonatal hypoglycemia was significantly related (p less than 0.05) to a maternal blood glucose level greater than 120 mg/dl, to a glucose infusion rate of 20 g/hr or greater and to an umbilical venous insulin level of greater than 40 microunits/ml. There were no major differences in neurobehavior that distinguished hypoglycemic neonates. It is recommended that the normal parturient be given less than 20 g/hr of intravenous glucose before delivery and have a blood glucose level less than 120 mg/dl at the time of delivery. Newborns delivered to mothers with hyperglycemia or excessive glucose infusion should be tested for hypoglycemia at 1 and 2 hours of age. PMID:7032366

  6. Analog and mixed-signal electronics

    CERN Document Server

    Stephan, Karl

    2015-01-01

    A practical guide to analog and mixed-signal electronics, with an emphasis on design problems and applications This book provides an in-depth coverage of essential analog and mixed-signal topics such as power amplifiers, active filters, noise and dynamic range, analog-to-digital and digital-to-analog conversion techniques, phase-locked loops, and switching power supplies. Readers will learn the basics of linear systems, types of nonlinearities and their effects, op-amp circuits, the high-gain analog filter-amplifier, and signal generation. The author uses system design examples to motivate

  7. Analog circuit design art, science, and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    Analog Circuit Design: Art, Science, and Personalities discusses the many approaches and styles in the practice of analog circuit design. The book is written in an informal yet informative manner, making it easily understandable to those new in the field. The selection covers the definition, history, current practice, and future direction of analog design; the practice proper; and the styles in analog circuit design. The book also includes the problems usually encountered in analog circuit design; approach to feedback loop design; and other different techniques and applications. The text is

  8. The relationship between gluconeogenic substrate supply and glucose production in humans

    International Nuclear Information System (INIS)

    The relationship between gluconeogenic precursor supply and glucose production has been investigated in 14-h and 86-h fasted humans. In protocols 1 and 2 [6,6-2H]glucose and [15N2]urea were infused to measure glucose and urea production rates (Ra) in response to infusions of glycerol and alanine. In protocol 3 first [15N]alanine, [3-13C]lactate, and [6,6-2H]glucose were infused before and during administration of dichloroacetate (DCA) to determine the response of glucose Ra to decreased fluxes of pyruvate, alanine, and lactate, then alanine was infused with DCA and glucose Ra measured. After a 14-h fast, neither alanine nor glycerol increased glucose Ra. Basal glucose Ra decreased by one-third after 86 h of fasting, yet glycerol and alanine infusions had no effect on glucose Ra. Glycerol always reduced urea Ra (P less than 0.05), suggesting that glycerol competitively inhibited gluconeogenesis from amino acids. DCA decreased the fluxes of pyruvate, alanine (P less than 0.01), and glucose Ra (P less than 0.01), which was prevented by alanine infusion. These findings suggest that (1) the reduction in glucose Ra after an 86-h fast is not because of a shortage of gluconeogenic substrate; (2) nonetheless, the importance of precursor supply to maintain basal glucose Ra is confirmed by the response to DCA; (3) an excess of one gluconeogenic substrate inhibits gluconeogenesis from others

  9. Exercise training improves fasting glucose control

    OpenAIRE

    Lewis N; Norton K; Norton L

    2012-01-01

    Lynda Norton,1 Kevin Norton,2 Nicole Lewis21School of Medicine, Flinders University, Adelaide, Australia; 2School of Health Science, University of South Australia, Adelaide, AustraliaPurpose: Numerous studies have measured changes in fasting blood glucose (FBG) levels in response to physical activity (PA) interventions. While studies involving clinical populations such as type 2 diabetics typically report significant reductions, most others report no change in FBG. This study investigated cha...

  10. The exoplanets analogy to the Multiverse

    CERN Document Server

    Kinouchi, Osame

    2015-01-01

    The idea of a Mutiverse is controversial, although it is a natural possible solution to particle physics and cosmological fine-tuning problems (FTPs). Here I explore the analogy between the Multiverse proposal and the proposal that there exist an infinite number of stellar systems with planets in a flat Universe, the Multiplanetverse. Although the measure problem is present in this scenario, the idea of a Multiplanetverse has predictive power, even in the absence of direct evidence for exoplanets that appeared since the 90s. We argue that the fine-tuning of Earth to life (and not only the fine-tuning of life to Earth) could predict with certainty the existence of exoplanets decades or even centuries before that direct evidence. Several other predictions can be made by studying only the Earth and the Sun, without any information about stars. The analogy also shows that theories that defend that the Earth is the unique existing planet and that, at the same time, is fine-tuned to life by pure chance (or pure phy...

  11. Glucagon responses to increasing oral loads of glucose and corresponding isoglycaemic intravenous glucose infusions in patients with type 2 diabetes and healthy individuals

    DEFF Research Database (Denmark)

    Bagger, Jonatan I; Knop, Filip K; Lund, Asger; Holst, Jens Juul; Vilsbøll, Tina

    2014-01-01

    increasing amounts of glucose given orally and corresponding isoglycaemic i.v. glucose infusions (IIGIs) in patients with type 2 diabetes and in healthy controls. METHODS: Plasma glucagon responses were measured during three 4 h OGTTs with increasing loads of glucose (25 g, 75 g and 125 g) and three...... oral glucose loads this difference increased and also became evident in healthy controls. CONCLUSIONS/INTERPRETATION: In patients with type 2 diabetes increasing amounts of oral glucose elicit hypersecretion of glucagon, whereas corresponding IIGIs result in significant glucagon suppression; a...... phenomenon that is also observed in healthy individuals when larger glucose loads are ingested orally. This suggests that the hyperglucagonaemic response to oral glucose in type 2 diabetes may represent a pathological version of a gut-derived physiological phenomenon. Trial registration: Clinical...

  12. Biomimetic Analogs for Collagen Biomineralization

    OpenAIRE

    Gu, L.; Kim, Y K; Liu, Y.; Ryou, H; Wimmer, C.E.; Dai, L.; Arola, D.D.; Looney, S.W.; Pashley, D H; Tay, F. R.

    2011-01-01

    Inability of chemical phosphorylation of sodium trimetaphosphate to induce intrafibrillar mineralization of type I collagen may be due to the failure to incorporate a biomimetic analog to stabilize amorphous calcium phosphates (ACP) as nanoprecursors. This study investigated adsorption/desorption characteristics of hydrolyzed and pH-adjusted sodium trimetaphosphate (HPA-Na3P3O9) to collagen. Based on those results, a 5-minute treatment time with 2.8 wt% HPA-Na3P3O9 was used in a single-layer ...

  13. Practical analog electronics for technicians

    CERN Document Server

    Kimber, W A

    2013-01-01

    'Practical Analog Electronics for Technicians' not only provides an accessible introduction to electronics, but also supplies all the problems and practical activities needed to gain hands-on knowledge and experience. This emphasis on practice is surprisingly unusual in electronics texts, and has already gained Will Kimber popularity through the companion volume, 'Practical Digital Electronics for Technicians'. Written to cover the Advanced GNVQ optional unit in electronics, this book is also ideal for BTEC National, A-level electronics and City & Guilds courses. Together with 'Practical Digit

  14. Role of Counterregulatory Hormones for Glucose Metabolism in Children and Adolescents with Type 1 Diabetes

    OpenAIRE

    Nishimura, Akiko; Kobayashi, Kisho; Yagasaki, Hideaki; Saito, Tomohiro; NAGAMINE, KENJIRO; Mitsui, Yumiko; Mochizuki, Mie; Satoh, Kazumasa; Kobayashi, Koji; Sano, Tomoaki; Ohta, Masanori; Cho, Hideo; Ohyama, Kenji

    2011-01-01

    To elucidate the mechanism of insulin resistance due to insulin counterregulatory hormones (ICRHs) and evaluate ICRH secretion kinetics, ICRH concentrations were measured and correlated with blood glucose levels in 28 type 1 diabetic patients. Blood glucose was measured before bedtime. Early morning urine samples were collected the next morning before insulin injection and breakfast. Fasting blood glucose, cortisol, glucagon and HbA1c levels were measured. Growth hormone (GH), ...

  15. Optical coherence tomography for glucose monitoring in blood

    Science.gov (United States)

    Ullah, Hafeez; Hussain, Fayyaz; Ikram, Masroor

    2015-08-01

    In this review, we have discussed the potential application of the emerging imaging modality, i.e., optical coherence tomography (OCT) for glucose monitoring in biological tissues. OCT provides monitoring of glucose diffusion in different fibrous tissues like in sclera by determining the permeability rate with acceptable accuracy both in type 1 and in type 2 diabetes. The maximum precision of glucose measurement in Intralipid suspensions, for example, with the OCT technique yields the accuracy up to 4.4 mM for 10 % Intralipid and 2.2 mM for 3 % Intralipid.

  16. Numerical Modeling on Non-enzymatic, Potentiometric Glucose Sensor

    Scientific Electronic Library Online (English)

    M., Kanagasabapathy; G.N.K., Ramesh Bapu; Praveen, Lingac; R.M., Gnanamuthud.

    2012-07-01

    Full Text Available A novel, enzymeless electrochemical sensing mechanism for glucose based on potentiometric measurement was proposed using the mediator hexacyanoferrate. In this methodology, EMF of the cell exclusively depends on glucose concentration and independent on reference half-cell electrode potential or medi [...] ator concentration or any other interfering factors. Electrochemical as well as mathematical models were proposed. Numerical computations along with boundary conditions were evaluated for the proposed models, to reduce the deviation in the interpolated results. Molar ratio of mediator to glucose was correlated with EMF cell. Numerical simulations, Legendre polynomials and Lagrange coefficients iterations can be executed through computer programs.

  17. Obduction: Why, how and where. Clues from analog models

    Science.gov (United States)

    Agard, P.; Zuo, X.; Funiciello, F.; Bellahsen, N.; Faccenna, C.; Savva, D.

    2014-05-01

    Obduction is an odd geodynamic process characterized by the emplacement of dense oceanic “ophiolites” atop light continental plates in convergent settings. We herein present analog models specifically designed to explore the conditions (i.e., sharp increase of plate velocities - herein coined as ‘acceleration’, slab interaction with the 660 km discontinuity, ridge subduction) under which obduction may develop as a result of subduction initiation. The experimental setup comprises an upper mantle modeled as a low-viscosity transparent Newtonian glucose syrup filling a rigid Plexiglas tank and high-viscosity silicone plates. Convergence is simulated by pushing a piston with plate tectonics like velocities (1-10 cm/yr) onto a model comprising a continental margin, a weakness zone with variable resistance and dip (W), an oceanic plate (with or without a spreading ridge), a preexisting subduction zone (S) dipping away from the piston and an upper active continental margin, below which the oceanic plate is being subducted at the start of the model (as for the Neotethyan natural example). Several configurations were tested over thirty-five parametric models, with special emphasis on comparing different types of weakness zone and the degree of mechanical coupling across them. Measurements of displacements and internal deformation allow for a precise and reproducible tracking of deformation. Models consistently demonstrate that once conditions to initiate subduction are reached, obduction may develop further depending on the effective strength of W. Results (1) constrain the range of physical conditions required for obduction to develop/nucleate and (2) underline the key role of such perturbations for triggering obduction, particularly plate ‘acceleration’. They provide an explanation to the short-lived Peri-Arabic obduction, which took place along thousands of km almost synchronously (within ?50-10 Myr), from Turkey to Oman, while the subduction zone beneath Eurasia became temporarily jammed. They also demonstrate that the emplacement of dense, oceanic material on continental lithosphere is not a mysterious process requiring extraordinary boundary conditions but results from large-scale, normal (oceanic then continental) subduction processes.

  18. Current concepts in blood glucose monitoring

    OpenAIRE

    Khadilkar, Kranti Shreesh; Bandgar, Tushar; Shivane, Vyankatesh; Lila, Anurag; Shah, Nalini

    2013-01-01

    Blood glucose monitoring has evolved over the last century. The concept of adequate glycemic control and minimum glycemic variability requires an ideal, accurate and reliable glucose monitoring system. The search for an ideal blood glucose monitoring system still continues. This review explains the various blood glucose monitoring systems with special focus on the monitoring systems like self- monitored blood glucose (SMBG) and continuous glucose monitoring system (CGMS). It also focuses on t...

  19. Modelling, verification, and calibration of a photoacoustics based continuous non-invasive blood glucose monitoring system

    Science.gov (United States)

    Pai, Praful P.; Sanki, Pradyut K.; Sarangi, Satyabrata; Banerjee, Swapna

    2015-06-01

    This paper examines the use of photoacoustic spectroscopy (PAS) at an excitation wavelength of 905 nm for making continuous non-invasive blood glucose measurements. The theoretical background of the measurement technique is verified through simulation. An apparatus is fabricated for performing photoacoustic measurements in vitro on glucose solutions and in vivo on human subjects. The amplitude of the photoacoustic signals measured from glucose solutions is observed to increase with the solution concentration, while photoacoustic amplitude obtained from in vivo measurements follows the blood glucose concentration of the subjects, indicating a direct proportionality between the two quantities. A linear calibration method is applied separately on measurements obtained from each individual in order to estimate the blood glucose concentration. The estimated glucose values are compared to reference glucose concentrations measured using a standard glucose meter. A plot of 196 measurement pairs taken over 30 normal subjects on a Clarke error grid gives a point distribution of 82.65% and 17.35% over zones A and B of the grid with a mean absolute relative deviation (MARD) of 11.78% and a mean absolute difference (MAD) of 15.27 mg/dl (0.85 mmol/l). The results obtained are better than or comparable to those obtained using photoacoustic spectroscopy based methods or other non-invasive measurement techniques available. The accuracy levels obtained are also comparable to commercially available continuous glucose monitoring systems.

  20. A photonic crystal fiber glucose sensor filled with silver nanowires

    Science.gov (United States)

    Yang, X. C.; Lu, Y.; Wang, M. T.; Yao, J. Q.

    2016-01-01

    We report a photonic crystal fiber glucose sensor filled with silver nanowires in this paper. The proposed sensor is both analyzed by COMSOL multiphysics software and demonstrated by experiments. The extremely high average spectral sensitivity 19009.17 nm/RIU for experimental measurement is obtained, equivalent to 44.25 mg/dL of glucose in water, which is lower than 70 mg/dL for efficient detection of hypoglycemia episodes. The silver nanowires diameter which may affect the sensor's spectral sensitivity is also discussed and an optimal range of silver nanowires diameter 90-120 nm is obtained. We expect that the sensor can provide an effective platform for glucose sensing and potentially leading to a further development towards minimal-invasive glucose measurement.

  1. Glucose metabolism of lactobacillus divergens

    International Nuclear Information System (INIS)

    The aim of this study was to compile an optimal growth and selective medium for Lactobacillus divergens and to determine the pathway by which it metabolised glucose. The optimum growth temperature is 25oC which is lower than that of most other lactobacilli. Citrate stimulates growth up to a concentration of 1% while acetate inhibits the organism at neutral pH, but it stimulates growth at pH 8.5 up to a concentration of 0.8%. MRS medium was therefore modified in order to obtain maximum growth of the organism. The acetate was omitted, sucrose was substituted for glucose and the pH was adjusted to 8.5. Sucrose was used, since a neutral pH is obtained after sterilisation of glucose in alkaline (pH ? 7.5) solution due to the degradation of glucose by the Maillard reaction. Various inhibitors and dyes were tested in order to formulate a selective medium. In the present study differently labelled glucose precursors were fermented by L. divergens and the fermentation products isolated by HPLC. The concentrations of acetate and formate were determined by comparison to a standard while the concentration of lactate and glucose was determined by enzymic assay. The radioactivity was determined by liquid scintillation counting and the positional labelling in lactate and acetate by chemical degradation. Fermentation of D-[U-14C]-glucose was included to correct for endogenous product dilution

  2. High precision, integrable, static memory for analog signals

    International Nuclear Information System (INIS)

    A circuit is presented which can be used for the realization of low cost, high precision integrated static memories for analog signals. Such memories could be advantageously employed for the implementation of multiple programmable voltage sources for control and measurement applications

  3. The analog of the Hawking effect in BECs

    OpenAIRE

    Fabbri, Alessandro

    2014-01-01

    The observation of the Hawking effect from black holes in the astrophysical context is unlikely. However, the analog of this effect is present in condensed matter systems. We focus on Bose-Einstein condensates, and on a proposal to detect it through correlation measurements.

  4. The 130Te (p,p') reaction on analog resonances

    International Nuclear Information System (INIS)

    Angular distributions for elastic and inelastic scattering have been measured on six analog resonances in the 130Te + p system and at two off resonance energies. Partial widths are deduced from the angular distributions. Formulae for the spectroscopic amplitudes within the framework of quasiparticle random phase approximation are presented. The experimental results are compared with the theoretical predictions. (Author)

  5. Capillary versus venous bedside blood glucose estimations

    OpenAIRE

    Boyd, R; Leigh, B; Stuart, P. (Pamela)

    2005-01-01

    Objectives: To determine the mean difference and correlation between capillary and venous bedside glucose estimation in comparison to laboratory blood glucose analysis in emergency department (ED) patients.

  6. Teamwork in high-risk environments analogous to space

    Science.gov (United States)

    Kanki, Barbara G.

    1990-01-01

    Mountaineering expeditions combine a number of factors which make them potentially good analogs to the planetary exploration facet of long-duration space missions. A study of mountain climbing teams was conducted in order to evaluate the usefulness of the environment as a space analog and to specifically identify the factors and issues surrounding teamwork and 'successful' team performance in two mountaineering environments. This paper focuses on social/organizational factors, including team size and structure, leadership styles and authority structure which were found in the sample of 22 climb teams (122 individuals). The second major issue discussed is the construction of a valid performance measure in this high-risk environment.

  7. Radioimmunoassay of Plasma Insulin during Oral Glucose Tolerance Test in Thyrotoxicosis

    International Nuclear Information System (INIS)

    Blood glucose and immunoreactive insulin (IRI) were measured during oral glucose tolerance test in 15 thyrotoxic patients and 8 normal controls, to study the glucose metabolism in thyrotoxicosis. Following were the results;1) In thyrotoxicosis, there is noticed late rise and late fall of plasma IRI during oral glucose tolerance test, like as phenomenon of mild diabetes mellitus. 2) When the thyrotoxic patients were divided into normal and abnormal responsive groups after the level of blood glucose by Wilkerson Criteria, no significant difference in plasma IRI levels were noticed between two groups. 3) This result may be interpreted as relative deficiency of insulin secretion from panaceas and suggest genetically related defects.

  8. Ingestion of Diet Soda Before a Glucose Load Augments Glucagon-Like Peptide-1 Secretion

    OpenAIRE

    Brown, Rebecca J.; Walter, Mary; Kristina I. Rother

    2009-01-01

    OBJECTIVE The goal of this study was to determine the effect of artificial sweeteners on glucose, insulin, and glucagon-like peptide (GLP)-1 in humans. RESEARCH DESIGN AND METHODS For this study, 22 healthy volunteers (mean age 18.5 ± 4.2 years) underwent two 75-g oral glucose tolerance tests with frequent measurements of glucose, insulin, and GLP-1 for 180 min. Subjects drank 240 ml of diet soda or carbonated water, in randomized order, 10 min prior to the glucose load. RESULTS Glucose excur...

  9. Home blood glucose concentrations in maturity-onset diabetes.

    OpenAIRE

    Paisey, R. B.; Bradshaw, P.; Hartog, M.

    1980-01-01

    Blood glucose concentrations during normal daily activities were measured in 106 patients with maturity-onset diabetes from capillary blood samples collected on to filter paper. Samples were taken before and two hours after main meals, before going to bed, and, in 51 cases, during the night. Fasting and mid-morning values were closely correlated with the mean values over 24 hours irrespective of the type of anti-diabetic treatment being given. Postprandial blood glucose concentrations remaine...

  10. Fat distribution and glucose intolerance among Greenland inuit

    DEFF Research Database (Denmark)

    Jørgensen, Marit Eika; Borch-Johnsen, Knut; Stolk, Ronald; Bjerregaard, Peter

    2013-01-01

    OBJECTIVE A high amount of subcutaneous fat is suggested to explain the observation of lower obesity-associated metabolic risk among Inuit than among Europeans. We examined the association between measures of obesity (visceral adipose tissue [VAT], subcutaneous adipose tissue [SAT], BMI, waist circumference [WC], and percentage of body fat) and the indices of glucose metabolism (fasting and 2-h glucose levels, insulin resistance per homeostasis model assessment [HOMA-IR], and the insulin sensiti...

  11. Development of a glucose sensor for diabetic patients

    OpenAIRE

    Wientjes, Klaas Jan Cornelis,

    2000-01-01

    his thesis describes the development of a glucose measurement system designed to monitor the glucose concentration of diabetic patients continuously. Diabetes Mellitus is a disorder of metabolism of carbohydrate, fat and protein associated with a relative or absolute insufficiency of insulin and protein associated with a relative or absolute insufficiency of inslun secretion and with various degrees of insulin resistance. The World Health Organisation (WHO) has estimated that diabetes affects...

  12. A possible mechanism of insulin resistance in the rat adipose cell in streptozotocin-induced diabetes mellitus. Depletion of intracellular glucose transport systems.

    OpenAIRE

    Karnieli, E; Hissin, P J; Simpson, I. A.; Salans, L B; Cushman, S. W.

    1981-01-01

    The effects of insulin-dependent diabetes mellitus on glucose transport activity and on the concentrations of glucose transport systems in the plasma and low density microsomal membranes in adipose cells isolated from streptozotocin-induced diabetic rats have been examined. Glucose transport activity was assessed by measuring 3-O-methylglucose transport and the concentration of glucose transport systems estimated by measuring specific D-glucose-inhibitable cytochalasin B-binding. Basal glucos...

  13. Membrane Affinity of Platensimycin and Its Dialkylamine Analogs

    Directory of Open Access Journals (Sweden)

    Ian Rowe

    2015-08-01

    Full Text Available Membrane permeability is a desired property in drug design, but there have been difficulties in quantifying the direct drug partitioning into native membranes. Platensimycin (PL is a new promising antibiotic whose biosynthetic production is costly. Six dialkylamine analogs of PL were synthesized with identical pharmacophores but different side chains; five of them were found inactive. To address the possibility that their activity is limited by the permeation step, we calculated polarity, measured surface activity and the ability to insert into the phospholipid monolayers. The partitioning of PL and the analogs into the cytoplasmic membrane of E. coli was assessed by activation curve shifts of a re-engineered mechanosensitive channel, MscS, in patch-clamp experiments. Despite predicted differences in polarity, the affinities to lipid monolayers and native membranes were comparable for most of the analogs. For PL and the di-myrtenyl analog QD-11, both carrying bulky sidechains, the affinity for the native membrane was lower than for monolayers (half-membranes, signifying that intercalation must overcome the lateral pressure of the bilayer. We conclude that the biological activity among the studied PL analogs is unlikely to be limited by their membrane permeability. We also discuss the capacity of endogenous tension-activated channels to detect asymmetric partitioning of exogenous substances into the native bacterial membrane and the different contributions to the thermodynamic force which drives permeation.

  14. Superconducting circuit probe for analog quantum simulators

    Science.gov (United States)

    Du, Liang-Hui; You, J. Q.; Tian, Lin

    2015-07-01

    Analog quantum simulators can be used to study quantum correlation in novel many-body systems by emulating the Hamiltonian of these systems. One essential question in quantum simulation is to probe the properties of an emulated many-body system. Here we present a circuit QED scheme for probing such properties by measuring the spectrum of a superconducting resonator coupled to a quantum simulator. We first study a general framework of this approach and show that the spectrum of the resonator is directly related to the correlation function of the coupling operator between the resonator and the simulator. We then apply this scheme to a simulator of the transverse field Ising model implemented with superconducting qubits, where the resonance peaks in the resonator spectrum correspond to the frequencies of the elementary excitations. The effects of resonator damping, qubit decoherence, and resonator backaction are also discussed. This setup can be used to probe a broad range of many-body models.

  15. READ - Remote Analog ASIC Design System

    Directory of Open Access Journals (Sweden)

    Michael E. Auer

    2006-11-01

    Full Text Available The scope of this work is to present a solution to implement a remote electronic laboratory for testing and designing analog ASICs (ispPAC10. The application allows users to create circuit schematics, upload the design to the device and perform measurements. The software used for designing circuits is the PAC-Designer and it runs on a Citrix server. The signals are generated and the responses are acquired by a data acquisition board controlled by LabView. The virtual instruments interact with some ActiveX controls specially designed to look like real oscilloscope and function generator devices and represent the user interface of the lab. These ActiveX give users the control over the LabView VIs and the access to its facilities in order to perform electronic exercises.

  16. HIGH RESOLUTION ANALOG / DIGITAL POWER SUPPLY CONTROLLER

    International Nuclear Information System (INIS)

    Corrector magnets for the SPEAR-3 synchrotron radiation source require precision, high-speed control for use with beam-based orbit feedback. A new Controller Analog/Digital Interface card (CANDI) has been developed for these purposes. The CANDI has a 24-bit DAC for current control and three 24-bit Δ-Σ ADCs to monitor current and voltages. The ADCs can be read and the DAC updated at the 4 kHz rate needed for feedback control. A precision 16-bit DAC provides on-board calibration. Programmable multiplexers control internal signal routing for calibration, testing, and measurement. Feedback can be closed internally on current setpoint, externally on supply current, or beam position. Prototype and production tests are reported in this paper. Noise is better than 17 effective bits in a 10 mHz to 2 kHz bandwidth. Linearity and temperature stability are excellent

  17. A QCD analogy for quantum gravity

    CERN Document Server

    Holdom, Bob

    2015-01-01

    Quadratic gravity presents us with a renormalizable, asymptotically free theory of quantum gravity. When its couplings grow strong at some scale, as in QCD, then this strong scale sets the Planck mass. QCD has a gluon that does not appear in the physical spectrum. Quadratic gravity has a spin-2 ghost that we conjecture does not appear in the physical spectrum. We discuss how the QCD analogy leads to this conjecture and to the emergence of general relativity. Certain aspects of the QCD path integral and its measure could also be similar for quadratic gravity. With the addition of the Einstein-Hilbert term, quadratic gravity has a dimensionful parameter that seems to control a quantum phase transition and the size of a mass gap in the strong phase.

  18. Analog to digital workflow improvement: a quantitative study.

    Science.gov (United States)

    Wideman, Catherine; Gallet, Jacqueline

    2006-01-01

    This study tracked a radiology department's conversion from utilization of a Kodak Amber analog system to a Kodak DirectView DR 5100 digital system. Through the use of ProModel Optimization Suite, a workflow simulation software package, significant quantitative information was derived from workflow process data measured before and after the change to a digital system. Once the digital room was fully operational and the radiology staff comfortable with the new system, average patient examination time was reduced from 9.24 to 5.28 min, indicating that a higher patient throughput could be achieved. Compared to the analog system, chest examination time for modality specific activities was reduced by 43%. The percentage of repeat examinations experienced with the digital system also decreased to 8% vs. the level of 9.5% experienced with the analog system. The study indicated that it is possible to quantitatively study clinical workflow and productivity by using commercially available software. PMID:16953340

  19. Quantitation of the pathways of hepatic glycogen formation on ingesting a glucose load

    Energy Technology Data Exchange (ETDEWEB)

    Magnusson, I.; Chandramouli, V.; Schumann, W.C.; Kumaran, K.; Wahren, J.; Landau, B.R.

    1987-12-01

    Diflunisal, 5-(2',4'-difluorophenyl)salicylic acid, excreted in urine as its glucuronide, was given to normal humans (n = 6) along with a glucose load specifically labeled with /sup 14/C. Glucuronide excreted by each subject was reduced to its glucoside and glucose from it degraded to yield the distribution of 14 C in its six carbons. Randomization of the /sup 14/C from the specifically labeled glucose was taken as a measure of the extent to which glucose was deposited indirectly (i.e., glucose----lactate----glucose----6-P----glycogen), rather than directly (i.e., glucose----glucose-6-P----glycogen). The maximum contribution to glycogen formation by the direct pathway was estimated to be 65 +/- 1%, on the assumption that glucuronide and glycogen are derived from the same hepatic pool of glucose-6-P in liver. Evidence that supports that assumption was obtained by comparing the randomization of /sup 14/C in the urinary glucuronide with that in glucose in blood from the hepatic vein of four of the subjects before and after they were given glucagon. Other evidence supporting the assumption was obtained by comparing in two subjects /sup 3/H//sup 14/C ratios in glucose from hepatic vein blood before and after glucagon administration with that in urinary glucuronide, having labeled the uridine diphosphate (UDP)-glucose in their livers with /sup 14/C by giving them 1-(/sup 14/C)galactose and their circulating glucose with /sup 3/H by giving a 5-(/sup 3/H)glucose-labeled load. It is concluded that glucuronide formation in humans can be used to trace glucose metabolism in the liver, and that in humans the indirect pathway of glucose metabolism is active.

  20. Rapid kinetics of liver microsomal glucose-6-phosphatase. Evidence for tight-coupling between glucose-6-phosphate transport and phosphohydrolase activity

    International Nuclear Information System (INIS)

    Rapid kinetics of both glucose-6-P uptake and hydrolysis in fasted rat liver microsomes were investigated with a recently developed fast-sampling, rapid-filtration apparatus. Experiments were confronted with both the substrate transport and conformational models currently proposed for the glucose-6-phosphatase system. Accumulation in microsomes of 14C products from [U-14C]glucose-6-P followed biexponential kinetics. From the inside to outside product concentrations, it could be inferred that mostly glucose should accumulate inside the vesicles. While biexponential kinetics are compatible with the mathematical predictions of a simplified substrate transport model, the latter fails in explaining the burst in total glucose production over a similar time scale to that used for the uptake measurements. Since the initial rate of the burst phase in untreated microsomes exactly matched the steady-state rate of glucose production in detergent-treated vesicles, it can be definitely concluded that the substrate transport model does not describe adequately our results. While the conformational model accounts for both the burst of glucose production and the kinetics of glucose accumulation into the vesicles, it cannot explain the burst in 32Pi production from [32P]glucose-6-P measured under the same conditions. Since the amplitude of the observed bursts is not compatible with a presteady state in enzyme activity, we propose that a hysteretic transition best explains our results in both untreated and permeabilized microsomes, thus providing a new rationale to understand the molecular mechanism of the glucose-6-phosphatase system