Enzymic fluorometric continuous-flow assays for blood glucose, lactate, pyruvate, alanine, glycerol, and 3-hydroxybutyrate.

1978 ◽  
Vol 24 (10) ◽  
pp. 1724-1729 ◽  
Author(s):  
B Lloyd ◽  
J Burrin ◽  
P Smythe ◽  
K G Alberti
Keyword(s):  
Blood Glucose ◽  
Perchloric Acid ◽  
Continuous Flow ◽  
Room Temperature ◽  
Automated Analysis ◽  
Low Concentrations ◽  
Coefficients Of Variation ◽  
Analytical Recovery ◽  
One Year ◽  
Fasting Subject

Abstract We describe enzymic fluorometric methods of automated analysis for glucose, lactate, pyruvate, 3-hydroxybutyrate, glycerol, and alanine in perchloric acid extracts of blood. Unmodified Technicon AutoAnalyzer II apparatus is used. The usual concentrations of all these metabolites can be measured in as little as 0.1 ml of blood from a fasting subject. Within-batch and between-batch coefficients of variation ranged from 0.4 to 4.4% for all metabolites except 3-hydroxybutyrate, for which CV's were higher for low concentrations. Analytical recovery of added metabolites ranged from 92 to 98%. Glucose, lactate, alanine, and 3-hydroxybutyrate are stable in perchloric acid extracts for at least 13 days at room temperature, and a year at -20 degrees C; pyruvate shows a 6--8% loss after 3 days and 52% by one year at -20 degrees C; glycerol concentrations were stable at -20 degrees C for at least 13 days. Blank fluorescence is found in perchloric acid extracts of blood, necessitating blank runs for pyruvate, 3-hydroxybutyrate, glycerol, and alanine. The systems are simple to use, relatively inexpensive to operate, and are recommended for any laboratory with high throughput of samples.

Micromethod for determination of creatinine in biological fluids by high-performance liquid chromatography.

1978 ◽  
Vol 24 (5) ◽  
pp. 747-750 ◽  
Author(s):  
S J Soldin ◽  
J G Hill
Keyword(s):  
High Performance Liquid Chromatography ◽  
Continuous Flow ◽  
Present Method ◽  
High Performance ◽  
Biological Fluids ◽  
Coefficients Of Variation ◽  
Analytical Recovery ◽  
Urine Specimens ◽  
Serum And Urine

Abstract We describe a procedure for the rapid and specific measurement of creatinine, in which it is separated from other compounds in serum or urine by paired-ion chromatography and is quantified by measuring its absorbance at 200 nm. The procedure can be done on as little as 10 microliter of serum. Between-day precision studies for concentrations of 13 and 62 mg/liter yielded coefficients of variation of 6.9 and 2.2%, respectively. Analytical recovery of various amounts of creatinine added to plasma exceeded 95% in all cases. The proposed procedure was compared with the continuous-flow procedure by analyzing a series of serum and urine specimens by both methods. There was excellent agreement for urine specimens, but with serum the results by the present method were significantly (P less than 0.001) lower.

Room Temperature Flow Electrochemistry as a Means of Retaining the “Memory of Chirality” via Hofer Moest Type Reaction

2020 ◽  
Author(s):  
Tomas Hardwick ◽  
Rossana Cicala ◽  
Nisar Ahmed
Keyword(s):  
Continuous Flow ◽  
Room Temperature ◽  
Biological Activities ◽  
Supporting Electrolyte ◽  
Enantiomeric Excess ◽  
Flow Chemistry ◽  
Batch Processes ◽  
Enabling Technology ◽  
Chiral Compounds ◽  
Memory Of Chirality

<p>Many chiral compounds have become of great interest to the pharmaceutical industry as they possess various biological activities. Concurrently, the concept of “memory of chirality” has been proven as a powerful tool in asymmetric synthesis, while flow chemistry has begun its rise as a new enabling technology to add to the ever increasing arsenal of techniques available to the modern day chemist. Here, we have employed a new simple electrochemical microreactor design to oxidise an L-proline derivative at room temperature in continuous flow. Flow performed in microreactors offers up a number of benefits allowing reactions to be performed in a more convenient and safer manner, and even allow electrochemical reactions to take place without a supporting electrolyte due to a very short interelectrode distance. By the comparison of electrochemical oxidations in batch and flow we have found that continuous flow is able to outperform its batch counterpart, producing a good yield (71%) and a better enantiomeric excess (64%) than batch with a 98% conversion. We have, therefore, provided evidence that continuous flow chemistry has the potential to act as a new enabling technology to replace some aspects of conventional batch processes. </p>

scholarly journals Ag Nanoparticles Sensitized In2O3 Nanograin for the Ultrasensitive HCHO Detection at Room Temperature

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Shiqiang Zhou ◽  
Mingpeng Chen ◽  
Qingjie Lu ◽  
Yumin Zhang ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Indoor Air ◽  
Ag Nanoparticles ◽  
Room Temperature ◽  
Unsolved Problem ◽  
Air Pollutant ◽  
Ag Nps ◽  
Performance Targets ◽  
Fabrication Cost ◽  
Low Concentrations ◽  
Stringent Performance

AbstractFormaldehyde (HCHO) is the main source of indoor air pollutant. HCHO sensors are therefore of paramount importance for timely detection in daily life. However, existing sensors do not meet the stringent performance targets, while deactivation due to sensing detection at room temperature, for example, at extremely low concentration of formaldehyde (especially lower than 0.08 ppm), is a widely unsolved problem. Herein, we present the Ag nanoparticles (Ag NPs) sensitized dispersed In2O3 nanograin via a low-fabrication-cost hydrothermal strategy, where the Ag NPs reduces the apparent activation energy for HCHO transporting into and out of the In2O3 nanoparticles, while low concentrations detection at low working temperature is realized. The pristine In2O3 exhibits a sluggish response (Ra/Rg = 4.14 to 10 ppm) with incomplete recovery to HCHO gas. After Ag functionalization, the 5%Ag-In2O3 sensor shows a dramatically enhanced response (135) with a short response time (102 s) and recovery time (157 s) to 1 ppm HCHO gas at 30 °C, which benefits from the Ag NPs that electronically and chemically sensitize the crystal In2O3 nanograin, greatly enhancing the selectivity and sensitivity.

Abstract 5853: Continuous Flow Left Ventricular Assist Device in Women with Advanced Heart Failure: Results After One Year of Support

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Salpy V Pamboukian ◽  
Roberta C Bogaev ◽  
Stuart D Russell ◽  
Andrew J Boyle ◽  
Nader Moazami ◽  
...  
Keyword(s):  
Heart Failure ◽  
Continuous Flow ◽  
Cardiac Transplantation ◽  
Causes Of Death ◽  
Left Ventricular ◽  
Advanced Heart Failure ◽  
Ventricular Assist Devices ◽  
Ventricular Assist ◽  
Left Ventricular Assist ◽  
One Year

Small continuous flow left ventricular assist devices (LVAD) are providing new options for women in advanced heart failure who due to body size limitations were historically excluded from use of large first generation pulsatile devices. We report the experience of women one year after implantation with the new, HeartMate II continuous flow LVAD for bridge to transplantation. Patients (n=279), 24% female (F), 76% male (M) in NYHA Class IV heart failure, LV ejection fraction 16±7% (F), 16±6% (M), mostly inotrope dependent and about half on intraaortic balloon pump support (50% F, 43% M), who had been enrolled in the HM II clinical trial for at least 1 year as a bridge to cardiac transplantation at 33 centers were analyzed. Outcomes and causes of death in the first year of support between F and M recipients were determined. The percentage of patients who had undergone transplantation, recovery of the heart with device removal, or continued on HM II support after one year were the same (80%) between M and F. However, the percentage of patients who had received a heart transplant was significantly less for F (38%) than M (53%) (p<0.05). Median duration of support for F was 226 days (range 8–1004) vs. 143 days (range 0–1057) for M. Mortality on device support was 20% for F and 18% M. There were no statistically significant differences in leading causes of death: sepsis (1.5% F vs 4.2% M), ischemic stroke (3.1% F vs 1.9% M), hemorrhagic stroke (3.1% F vs 1.4% M), and right heart failure (3.1% F vs 1.9% M). Of 82 patients continuing on support at 1 year, 26 (32%) were F with median BSA of 1.65 vs 2.14 m 2 for M. Kaplan Meier survival at one year was similar for females (74%) and males (76%). The smaller, more durable HM II rotary LVAD may be especially advantageous to women with advanced HF as a bridge to cardiac transplantation, because of significantly smaller BSA and need for extended duration of mechanical support due to longer wait times for suitable organ donors. Outcomes at one-year

scholarly journals Evaluation of pyrite and pyrrhotite in concretes

2016 ◽  
Vol 9 (3) ◽  
pp. 484-493 ◽  
Author(s):  
A. P. Marcelino ◽  
J. M. Calixto ◽  
A. G. Gumieri ◽  
M. C. Ferreira ◽  
C. L. Caldeira ◽  
...  
Keyword(s):  
Room Temperature ◽  
Iron Sulfide ◽  
Hydroelectric Power Plant ◽  
Hydroelectric Power ◽  
Rock Samples ◽  
Limit Value ◽  
Plant Area ◽  
Different Temperatures ◽  
Pyrite Content ◽  
One Year

ABSTRACT It is well known that aggregate characteristics can intensively interfere in concrete behavior especially when sulfides are presented in the aggregates. The lack of consensus to content limit value of these deleterious sulfur compounds in concrete structures for dams has motivated several investigations worldwide. Within this scenario, this work presents a methodology to evaluate the presence of pyrite and pyrrhotite in concretes produced with aggregates containing sulfides. For the study, rock samples from the Irapé hydroelectric power plant area in Minas Gerais (Brazil) were used. This plant was built in a geological site where the rock presented sulfide levels of at least 3%. These rock samples were first ground and then used as aggregates in mortars, which were, during almost one year, subjected to three different exposed conditions: temperature of 23° ± 2°C and relative humidity of 95 to 100%; calcium hydroxide solution diluted in water kept at two different temperatures: room temperature and 50° C. The presence and amount of pyrrhotite were obtained from a leaching process of the material (aggregate or mortar) in a solution of hydrochloric acid. This procedure allowed also the evaluation of the pyrite content. The results showed that the amount of pyrite has remained virtually constant over time in the three exposure situations. This finding indicates that sulfur limits in aggregates should be set according to the type of iron sulfide presented and not solely by the total amount of sulfur.

Long-term treatment of acromegaly with the slow-release somatostatin analogue lanreotide

1994 ◽  
Vol 131 (1) ◽  
pp. 20-26 ◽  
Author(s):  
Josef Marek ◽  
Václav Hána ◽  
Michal Kršek ◽  
Vlasta Justová ◽  
France Catus ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Slow Release ◽  
Serum Levels ◽  
Term Treatment ◽  
Somatostatin Analogue ◽  
Tumour Mass ◽  
Long Term Treatment ◽  
Active Acromegaly ◽  
One Year

Marek J, Hána V. Kršek M. Justová V, Catus F, Thomas F. Long-term treatment of acromegaly with the slow-release somatostatin analogue lanreotide. Eur J Endocrinol 1994;131:20–6. ISSN 0804–4643 Thirteen patients with active acromegaly despite previous surgery were treated with 30 mg lanreotide im twice a month for 9 months. In 10 subjects the treatment continued to 19 months. GH serum levels of all patients decreased significantly from an initial value of 32.0 (29.4) μg/l [median (standard error of median)] to 10.0 (3.6) and 19.1 (5.7) after 3 and 9 months of treatment, respectively. In the 10 patients with the treatment longer than one year the decrease in GH was from 46.8 (29.4) μg/l to 12.5 (5.0) and 16.1 (5.3) after 13 and 19 months, respectively. IGF-I serum levels decreased significantly from 1193 (73)μg/l to 782 (99) and 621 (103) after 3 and 9 months, respectively, and were normalized in 3 patients. In the 10 patients treated for longer than one year, levels decreased significantly from 1318 (74)μg/l to 653 (170) and 742 (180) after 13 and 19 months, respectively. IGF BP-3 levels were reduced to the normal range in 6 patients and decreased from 8.7 (1.5)mg/l to 6.4 (0.8) and to 5.4 (1.0) after 3 and 9 months, respectively. In the patients with the 19 months treatment the decrease was from 9.3 (1.6) mg/l to 3.9 (0.9) and 4.8 (0.9) after 13 and 19 months, respectively. The IGF BP-3 to IFG I ratio increased in 7 patients. This elevation significantly correlated with the decrease in bioassayable somatomedin. Prolactin serum levels fell in all patients with increased prolactin secretion. Testosterone plasma levels increased in 4 out of 5 men without replacement therapy. Clinical improvement was observed in all patients. A reduction of tumour mass was observed in five patients and complete disappearance of the tumour in one subject. All patients complained of mild abdominal pain and softened stools for several days following the injections. However, these side effects never required interruption of treatment. Asymptomatic microlithiasis was seen in only one patient after 13 months, which led to treatment being suspended for a period of 3 months after which it was resumed. Fasting serum insulin and insulin area under the curve (AUC) after oral glucose tolerance test (OGTT) fell in all patients. Fasting blood glucose, fructosamine and glucose AUC after OGTT slightly increased during the treatment, but all blood glucose levels (fasting and during OGTT) remained within normal ranges. Lanreotide appears to be a safe and effective treatment in patients with active acromegaly unresolved by surgery. The long-acting formulation avoids the drawbacks associated with either repeated daily injections or continuous infusions of somatostatin analogues. Josef Marek, Third Department of Medicine, Charles University, U nemocnice 1, 128 21 Praha 2, The Czech Republic

scholarly journals Metallicity and Superconductivity in Doped Strontium Titanate

2019 ◽  
Vol 10 (1) ◽  
pp. 25-44 ◽  
Author(s):  
Clément Collignon ◽  
Xiao Lin ◽  
Carl Willem Rischau ◽  
Benoît Fauqué ◽  
Kamran Behnia
Keyword(s):  
Liquid Helium ◽  
Free Path ◽  
Coulomb Interaction ◽  
Strontium Titanate ◽  
Room Temperature ◽  
Mean Free Path ◽  
Helium Temperature ◽  
Ongoing Research ◽  
Low Concentrations ◽  
Wide Gap

Strontium titanate is a wide-gap semiconductor avoiding a ferroelectric instability thanks to quantum fluctuations. This proximity leads to strong screening of static Coulomb interaction and paves the way for the emergence of a very dilute metal with extremely mobile carriers at liquid-helium temperature. Upon warming, mobility decreases by several orders of magnitude. Yet, metallicity persists above room temperature even when the apparent mean free path falls below the electron wavelength. The superconducting instability survives at exceptionally low concentrations and beyond the boundaries of Migdal–Eliashberg approximation. An intimate connection between dilute superconductivity and aborted ferroelectricity is widely suspected. In this review, we give a brief account of ongoing research on bulk strontium titanate as an insulator, a metal, and a superconductor.

Rapid high conversion of high free fatty acid feedstock into biodiesel using continuous flow vortex fluidics

RSC Advances ◽  
2015 ◽  
Vol 5 (3) ◽  
pp. 2276-2280 ◽  
Author(s):  
Joshua Britton ◽  
Colin L. Raston
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Continuous Flow ◽  
Room Temperature ◽  
Flow Chemistry ◽  
Environmentally Benign ◽  
High Free Fatty Acid ◽  
Rapid Reduction ◽  
Biodiesel Feedstock ◽  
Flow Vortex

Rapid reduction of free fatty acids in biodiesel feedstock: the rapid conversion of problematic free fatty acids in bio-oils has been achieved using room temperature, environmentally benign vortex fluidic flow chemistry.

scholarly journals Effect of GNWs/NiO-WO3/GNWs Heterostructure for NO2 Gas Sensing at Room Temperature

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 626
Author(s):  
Seokhun Kwon ◽  
Seokwon Lee ◽  
Joouk Kim ◽  
Chulmin Park ◽  
Hosung Jung ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Room Temperature ◽  
Microwave Plasma ◽  
Gas Sensing ◽  
Chemical Vapor ◽  
Gas Concentration ◽  
Negative Change ◽  
Low Concentrations ◽  
Detection Characteristics ◽  
No2 Detection

Recently, as air pollution and particulate matter worsen, the importance of a platform that can monitor the air environment is emerging. Especially, among air pollutants, nitrogen dioxide (NO2) is a toxic gas that can not only generate secondary particulate matter, but can also derive numerous toxic gases. To detect such NO2 gas at low concentration, we fabricated a GNWs/NiO-WO3/GNWs heterostructure-based gas sensor using microwave plasma-enhanced chemical vapor deposition (MPECVD) and sputter, and we confirmed the NO2 detection characteristics between 10 and 50 ppm at room temperature. The morphology and carbon lattice characteristics of the sensing layer were investigated using field emission scanning electron microscopy (FESEM) and Raman spectroscopy. In the gas detection measurement, the resistance negative change according to the NO2 gas concentration was recorded. Moreover, it reacted even at low concentrations such as 5–7 ppm, and showed excellent recovery characteristics of more than 98%. Furthermore, it also showed a change in which the reactivity decreased with respect to humidity of 33% and 66%.

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