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Many Drawbacks (many + drawback)

Distribution by Scientific Domains

Medical Sciences	40%
Life Sciences	40%

Selected Abstracts

Review article: renal function assessment in cirrhosis , difficulties and alternative measurements

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 7 2007
E. CHOLONGITAS
Summary Background, Renal function in patients with cirrhosis is important prognostically, both before and following liver transplantation. Its prognostic impact is reflected by the inclusion of serum creatinine in the model for end-stage liver disease score, which is now used for recipient prioritization on liver transplantation waiting lists in the USA. Aim, To review the accuracy of the surrogate markers for the assessment of renal function, i.e. glomerular filtration rate, particularly in patients with cirrhosis. Method, We reviewed the available literature in PubMed regarding the markers for GFR evaluation and the factors which affect their accuracy in cirrhosis. Results, Although creatinine is widely available, it is an unreliable marker of glomerular filtration rate, particularly in patients with cirrhosis. Clearance of exogenous markers is considered the ,gold standard', but this methodology has many drawbacks, particularly poor applicability. Several mathematical formulae for estimated glomerular filtration rate are used to overcome some of these limitations: Cockcroft-Gault and Modification of Diet in Renal Disease formulae are the most frequently applied, but they are based on serum creatinine. Conclusions, Due to the inaccuracy of serum creatinine and its derived formulae in estimating glomerular filtration rate, alternative serum markers, such as cystatin C, and new formulae are desirable. These need formal evaluation in patients with cirrhosis so as to have a reliable surrogate of glomerular filtration rate, and to obviate many problems that are associated with using creatinine and estimated glomerular filtration rate. [source]

Characterisation of lubricants on ball bearings by FT-IR using an integrating sphere

LUBRICATION SCIENCE, Issue 3 2007
K.W. Street
Abstract Fourier transform-infrared reflectance microspectroscopy has been used extensively for the examination of coatings on non-planar surfaces such as ball bearings. While this technique offers considerable advantages, practical application has many drawbacks, some of which are easily overcome by the use of integrating sphere technology. This paper described the use of an integrating sphere for the quantification of thin layers of lubricant on the surface of ball bearings and the parameters that require optimisation in order to obtain reliable data. Several applications of the technique were discussed including determination of lubricant load on 12.7mm steel ball bearings and the examination of degraded lubricant on post-mortem specimens. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Protein Diffusion Probed by the Transient Grating Method with a New Type of Photochromic Molecule,

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2008
Takeshi Eitoku
A new type of photochromic molecule that can be used for diffusion coefficient (D) measurements of various proteins in solution is described. The absorption spectrum of this molecule is changed upon photoexcitation by the trans,cis isomerization reaction. Target proteins were labeled by this photochromic molecule in the dark and the translational motion of the proteins was detected by the transient grating (TG) method. The TG signal was simple enough to determine D accurately and was stable even for long-time irradiation by the laser light. The TG method using this probe molecule improves many drawbacks of the other techniques. [source]

Telemetric Intracavernosal and Intraspongiosal Pressure Monitoring

THE JOURNAL OF SEXUAL MEDICINE, Issue 10 2008
Rany Shamloul MD
ABSTRACT Introduction., Despite the major breakthroughs basic research in erectile physiology experienced in the last, most of the methods used for quantitative assessment of erectile function in longitudinal studies suffer many drawbacks. Objective., This review will focus on radiotelemetric assessment of intracavernosal (ICP) and intraspongiosal (ISP) regarding the technique, data collection, interpretation, and overall benefits. Results., Telemetric recording of ICP and ISP allows for qualitative and quantitative assessment of erectile responses in experimental animals, a characteristic that is not possible using other techniques. This technique has many advantages that can collectively lead to production of high quality data regarding erection. The system suffers two drawbacks, its high cost and the need for surgical implantation of the transmitter. Conclusion., The use of telemetric monitoring of ICP and ISP carries many advantages that will, hopefully, establish this technique as the gold standard method for assessment of erectile responses in the near future. Shamloul R. Telemetric intracavernosal and intraspongiosal pressure monitoring. J Sex Med 2008;5:2246,2252. [source]

Oxidative Degradation of Azo Dyes by Manganese Peroxidase under Optimized Conditions

BIOTECHNOLOGY PROGRESS, Issue 2 2003
I. Mielgo
The application of enzyme-based systems in waste treatment is unusual, given that many drawbacks are derived from their use, including low efficiency, high costs and easy deactivation of the enzyme. The goal of this study is the development of a degradation system based on the use of the ligninolytic enzyme manganese peroxidase (MnP) for the degradation of azo dyes. The experimental work also includes the optimization of the process, with the objective of determining the influence of specific physicochemical factors, such as organic acids, H2O2 addition, Mn2+ concentration, pH, temperature, enzyme activity and dye concentration. A nearly total decolorization was possible at very low reaction times (10 min) and at high dye concentration (up to 1500 mg L,1). A specific oxidation capacity as high as 10 mg dye degraded per unit of MnP consumed was attained for a decolorization higher than 90%. Among all, the main factor affecting process efficiency was the strategy of H2O2 addition. The continuous addition at a controlled flow permitted the progressive participation of H2O2 in the catalytic cycle through a suitable regeneration of the oxidized form of the enzyme, which enhanced both the extent and the rate of decolorization. It was also found that, in this particular case, the presence of a chelating organic acid (e.g., malonic) was not required for an effective operation. Probably, Mn3+ was chelated by the dye itself. The simplicity and high efficiency of the process open an interesting possibility of using of MnP for solving other environmental problems. [source]