urea method

2020 ◽  
Author(s):  
C. Sloby
Keyword(s):  
Urea Method

Total Energy Expenditure and Physical Activity Measured with the Bicarbonate-Urea Method in Patients with Human Immunodeficiency Virus Infection

1996 ◽  
Vol 91 (2) ◽  
pp. 241-245 ◽  
Author(s):  
N. I. J. Paton ◽  
M. Elia ◽  
S. A. Jebb ◽  
G. Jennings ◽  
D. C. MacAllan ◽  
...  
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Total Energy ◽  
Physical Activity Level ◽  
Resting Energy Expenditure ◽  
Total Energy Expenditure ◽  
Activity Level ◽  
Hiv Positive ◽  
Urea Method ◽  
Resting Energy

1. Our objectives were to measure total energy expenditure, the daily variation in total energy expenditure and the physical activity level in a group of HIV-positive subjects using the bicarbonate-urea method. The study also aimed to assess the practicalities of using the bicarbonate-urea technique in free-living conditions. 2. Total energy expenditure was measured with the bicarbonate-urea method over 2 consecutive days (1 day in one subject) in 10 male patients with HIV infection (median CD4 count = 30). Resting energy expenditure was measured by indirect calorimetry. Physical activity level (total energy expenditure/resting energy expenditure) was calculated from these measurements and from activity diaries. 3. Resting energy expenditure was found to be 7.46 ± 0.87 MJ/day, 5% higher than predicted values. Total energy expenditure was 10.69 ± 1.95 MJ/day with an intra-individual day-to-day variation of 6 ± 6%. The measured physical activity level was 1.42 ± 0.14, higher than the diary estimate of 1.34 ± 0.16 (P = 0.029), and there were large inter-method differences in individual values. The subcutaneous infusion of bicarbonate was well tolerated and did not seem to restrict normal activities. 4. Total energy expenditure was not elevated in the group of HIV-positive subjects when compared with reference values for normal subjects. The physical activity level of the patients in this study was lower than that measured using other techniques in healthy young men, but was compatible with that expected for people leading a sedentary lifestyle. Reductions in physical activity in patients with HIV are likely to contribute to the wasting process and physical activity level may thus be a clinically useful measure. This study has also provided the first tracer estimate of the day-to-day variation in total energy expenditure. The bicarbonate-urea method represents an important new investigative tool for measuring total energy expenditure which has previously only been possible within the confines of a whole-body calorimeter or using the expensive doubly labelled water method.

Production of cellulose aerogels from coir fibers via an alkali–urea method for sorption applications

Cellulose ◽  
2019 ◽  
Vol 26 (18) ◽  
pp. 9583-9598 ◽  
Author(s):  
Mar’atul Fauziyah ◽  
Widiyastuti Widiyastuti ◽  
Ratna Balgis ◽  
Heru Setyawan
Keyword(s):  
Coir Fibers ◽  
Urea Method

Rapid hemostatic chitosan/cellulose composite sponge by alkali/urea method for massive haemorrhage

2020 ◽  
Vol 164 ◽  
pp. 2769-2778 ◽  
Author(s):  
Xialian Fan ◽  
Yijin Li ◽  
Na Li ◽  
Guangming Wan ◽  
Muhammad Amir Ali ◽  
...  
Keyword(s):  
Massive Haemorrhage ◽  
Cellulose Composite ◽  
Urea Method

scholarly journals Preparation of the Hybrids of Hydrotalcites and Chitosan by Urea Method and Their Antimicrobial Activities

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1588 ◽  
Author(s):  
Bi Foua Claude Alain Gohi ◽  
Hong-Yan Zeng ◽  
Xiao-Ju Cao ◽  
Kai-Min Zou ◽  
Wenlin Shuai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Surface Properties ◽  
Antimicrobial Agents ◽  
Materials Science ◽  
Mechanical Stability ◽  
Antimicrobial Activities ◽  
Molar Ratio ◽  
Penicillium Cyclopium ◽  
Urea Method

Hybrid nano-supra molecular structured materials can boost the functionality of nano- or supra-molecular materials by providing increased reactivity and conductivity, or by simply improving their mechanical stability. Herein, the studies in materials science exploring hybrid systems are investigated from the perspective of two important related applications: healthcare and food safety. Interfacing phase strategy was applied, and ZnAl layered double hydroxide-chitosan hybrids, prepared by the urea method (U-LDH/CS), were successfully synthesized under the conditions of different chitosan(CS) concentrations with a Zn/Al molar ratio of 5.0. The structure and surface properties of the U-LDH/CS hybrids were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectrometer(FTIR), scanning electronmicroscopy (SEM), ultravioletvisible (UV-Vis), and zero point charge (ZPC) techniques, where the effect of CS concentration on the structure and surface properties was investigated. The use of the U-LDH/CS hybrids as antimicrobial agents against Escherichia coli, Staphylococcus aureus, and Penicillium cyclopium was investigated in order to clarify the relationship between microstructure and antimicrobial ability. The hybrid prepared in a CS concentration of 1.0 g∙L−1 (U-LDH/CS1) exhibited the best antimicrobial activity and exhibited average inhibition zones of 24.2, 30.4, and 22.3mm against Escherichia coli, Staphylococcus aureus, and Penicillium cyclopium, respectively. The results showed that the appropriate addition of CS molecules could increase antimicrobial ability against microorganisms.

Predicting arterio-venous fistula failure by urea–method derived access blood flow in chronic hemodialysis patients

2020 ◽  
Vol 21 (6) ◽  
pp. 1011-1016
Author(s):  
Kumtorn Lelamali ◽  
Piyarek Papirachanat ◽  
Thitiya Puavilai
Keyword(s):  
Blood Flow ◽  
Characteristic Curve ◽  
Hemodialysis Patients ◽  
Chronic Hemodialysis ◽  
Interquartile Range ◽  
Dialysis Access ◽  
Ultrasound Dilution ◽  
Limb Edema ◽  
Venous Fistula ◽  
Urea Method

Background: Dialysis access is an essential part of hemodialysis. Determining the access blood flow (Qa) can help predict arterio-venous fistula thrombosis. Qa determination by the urea method, which was previously described in the past is simple and is available in most of the dialysis units but was not be able to predict arterio-venous fistula thrombosis. Aim: To compare the efficacy of Qa determination by the urea method and by ultrasound dilution methods in predicting arterio-venous fistula failure. Methods: Qa was measured by urea method and by ultrasound dilution simultaneously, every 3 months for a period of 1 year, in stable chronic hemodialysis patients with arterio-venous fistula. Arterio-venous fistula failure determined by clinical parameters and confirmed by Doppler ultrasound before sending the patient for interventional angioplasty. Results: This study enrolled a total of 16 patients, with 63% being male, 75% with lower-arm arterio-venous fistula and around 43% with previously done angioplasty. 59-Qa measurements were done, and 6 patients underwent angioplasty (one patient for severe upper limb edema, one for access thrombosis, and four for access dysfunction). Qa determination by the urea method had non-significantly lower Qa, (745 mL/min (interquartile range: 509–1143) and 779 mL/min (interquartile range: 530–1160), (p = 0.58)) and high correlation (r = 0.83, p < 0.001) to Qa by ultrasound dilution. The cut-off criteria with its sensitivity and specificity in predicting the access failure were 440 mL/min, 66.67%, and 96.15% for Qa determination by the urea and 400 mL/min, 66.67% and 90.38% for Qa by ultrasound dilution, respectively, with no difference in the area under the receiver operating characteristic curve. Conclusion: Measurement of Qa determination by the urea method is well correlated with Qa by ultrasound dilution and can be used to predict vascular access failure.

The extraction, characterization andin vitrotranslation of RNA from adultSchistosoma mansoni

Parasitology ◽  
1982 ◽  
Vol 84 (2) ◽  
pp. 253-261 ◽  
Author(s):  
M. P. R. Tenniswood ◽  
A. J. G. Simpson
Keyword(s):  
Schistosoma Mansoni ◽  
Lithium Chloride ◽  
Gel Electrophoresis ◽  
Rabbit Reticulocyte Lysate ◽  
Agarose Gel ◽  
Agarose Gel Electrophoresis ◽  
Molecular Weights ◽  
Reticulocyte Lysate ◽  
Urea Method

SUMMARYWe have extracted RNA fromSchistosoma mansoniusing the lithium chloride–urea method which gives good yields of undegraded RNA. The results of agarose gel electrophoresis of RNA extracted by this procedure suggest thatS. mansonihas anin vivonick in the large rRNA sub-unit. Translation of the RNA in a rabbit reticulocyte lysate gave significant incorporation of [35S]methionine into synthesized proteins. Immuno-precipitation of these translation products using a hyperimmune monkey serum sedimented between 5 and 8% of the radioactivity, which appeared to be present in approximately 13 proteins of molecular weights 18, 20, 21, 22, 23, 35, 40, 54, 60, 70, 74, 78 and 105 K Daltons.

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