A Survey of Optimal Recovery

Author(s):  
C. A. Micchelli ◽  
T. J. Rivlin
Keyword(s):  
1979 ◽  
Vol 41 (02) ◽  
pp. 365-383 ◽  
Author(s):  
C Kluft

SummaryEffects due to plasma plasminogen activators and proactivators are usually studied in assay systems where inhibitors influence the activity and where the degree of activation of proactivators is unknown. Quantitative information on activator and proactivator levels in plasma is therefore not availableStudies on the precipitating and activating properties of dextran sulphate in euglobulin fractionation presented in this paper resulted in the preparation of a fraction in which there was optimal recovery and optimal activation of a number of plasminogen activators and proactivators from human plasma. The quantitative assay of these activators on plasminogen-rich fibrin plates required the addition of flufenamate to eliminate inhibitors. The response on the fibrin plates (lysed zones) could be coverted to arbitrary blood activator units (BAU). Consequently, a new activator assay which enables one to quantitatively determine the plasma level of plasminogen activators and proactivators together is introduced.Two different contributions could be distinguished: an activity originating from extrinsic activator and one originating from intrinsic proactivators. The former could be assayed separately by means of its resistance to inhibition by Cl-inactivator. Considering the relative concentrations of extrinsic and intrinsic activators, an impression of the pattern of activator content in plasma was gained. In morning plasma with baseline levels of fibrinolysis, the amount of extrinsic activator was negligible as compared to the level of potentially active intrinsic activators. Consequently, the new assay nearly exclusively determines the level of intrinsic activators in morning plasma. A pilot study gave a fairly stable level of 100 ± 15 BAU/ml (n = 50). When fibrinolysis was stimulated by venous occlusion (15 min), the amount of extrinsic activator was greatly increased, reaching a total activator level of 249 ± 27 BAU/ml (n = 7).


1999 ◽  
Vol 40 (11-12) ◽  
pp. 21-24
Author(s):  
Tapio Pento

Industrial ecology (IE) is a biological concept applied to industrial structures. The basic concepts of IE include regional, intra-firm and product-based waste recycling systems as well as the principle of upward and downward cascading. In best current examples of regional systems, several parties are in an industrial waste re-use symbiosis. Paper industry has learned to arrange the recovery and re-use of its products on distant markets, even up to a level where indications of exceeding optimal recovery and re-use rates already exist through deteriorated fibre and product quality. Such occurrences will take place in certain legislative-economic situations. Paper industry has many cascade levels, each with their internal recovery and recycling, as well as many intra-firm, regional, and life cycle ecology structures. As an example of prospects for individual cascading routes, sludges may continue to be incinerated, but the route to landfills will be closed. The main obstacles of legislative drive toward better IE systems are in many cases existing laws and political considerations rather than economic or technical aspects. The study and practice of engineering human technology systems and related elements of natural systems should develop in such a way that they provide quality of life by actively managing the dynamics of relevant systems to reduce the risk and scale of undesirable behavior and outcomes. For the paper industry, earth systems engineering offers several development routes. One of them is the further recognition of and research on the fact that the products of the industry are returned back to the carbon cycle of the natural environment. Opportunities for modifying current earth systems may also be available for the industry, e.g. genetically modified plants for raw materials or organisms for making good quality pulp out of current raw materials. It is to be recognized that earth systems engineering may become a very controversial area, and that very diverse political pressures may determine its future usefulness to the paper industry.


2021 ◽  
Vol 218 ◽  
pp. 108939
Author(s):  
Toshihira Irisawa ◽  
Reika Aratake ◽  
Miho Hanai ◽  
Yoshiki Sugimoto ◽  
Yasuhiro Tanabe

2021 ◽  
Vol 9 (8) ◽  
pp. 1597
Author(s):  
Dominic Stephenson ◽  
Audrey Perry ◽  
Andrew Nelson ◽  
Ali E. Robb ◽  
Matthew F. Thomas ◽  
...  

Nontuberculous mycobacteria are important respiratory pathogens in patients with cystic fibrosis (CF). For diagnosis, international guidelines recommend culture of sputum that has been decontaminated via chemical treatment. Fifty-six sputum samples from 32 patients known to be previously colonized or infected with NTM were subdivided, and the aliquots were subjected to six different decontamination strategies, followed by quantitative culture for NTM. Thirty sputum samples contained Mycobacterium abscessus complex (MABSC) and 11 contained Mycobacterium avium complex (MAC). Decontamination strategies included treatment with N-acetyl L-cysteine with 2% sodium hydroxide (NALC-NaOH), 4% NaOH, 1% chlorhexidine, 0.5 N sulfuric acid, 5% oxalic acid, double decontamination with NALC-NaOH, followed by 5% oxalic acid, and saline (0.85%) as a control. The samples were also cultured directly with no treatment. Treatment with NALC-NaOH resulted in an average reduction in colony count of 87% for MABSC when compared with direct culture. NaOH at 4% caused a 98.3% average reduction in colony count. All treatments that included NaOH resulted in colony counts that were statistically lower than those obtained from direct culture or the saline-treated control (p < 0.05). Standard treatments using sulfuric or oxalic acids were less deleterious, but still resulted in an average reduction in colony count of at least 30%. The viability of MAC was much less affected by most decontamination treatments. In conclusion, the viability of MABSC was severely compromised by standard decontamination regimens. This supports recent evidence showing that optimal recovery of MABSC is achieved by culture on an appropriate selective agar without decontamination of sputum samples.


2020 ◽  
Vol 2020 ◽  
pp. 1-3
Author(s):  
Balaji Subramanyam ◽  
Gomathi Sivaramakrishnan ◽  
Devi Sangamithrai ◽  
Rajkumar Ravi ◽  
Kannan Thiruvengadam ◽  
...  

Optimal recovery of mycobacteria from the contaminated liquid culture is a challenge. While alternative methods have been suggested to reduce the rate of contamination in the BACTEC MGIT 960 system, reprocessing the contaminated liquid culture improves recovery of Mycobacterium tuberculosis. Among 793 MGIT cultures raised from as many sputum specimens after primary decontamination by the standard NaLC-NaOH method, valid results were available for 687 (86.6%) as 106 (13.4%) were contaminated. Reprocessing and reculturing of the contaminated cultures increased valid results to 739 (93.2%) and reduced the contamination rate to 6.8%. Both values were statistically significant. Recovery of the Mycobacterium tuberculosis complex increased from 45.6% to 48.4%. Valid negative results were available for an additional 3.4%. The method may be adopted to reduce the rate of contamination and to improve the valid culture results for mycobacteria.


1992 ◽  
Vol 40 (8) ◽  
pp. 1987-1996 ◽  
Author(s):  
R.G. Shenoy ◽  
T.W. Parks

2018 ◽  
Vol 106 (11) ◽  
pp. 909-916
Author(s):  
Louisa Bounemia ◽  
Abdelhamid Mellah

Abstract The pretreatment of the phosphoric acid is a stage of utmost importance leading to an optimal recovery of the uranium present in this acid. To this end, the degradation of the organic matter which obstructs considerably this recovery was tested by γ irradiation. This study lies within the scope of the radiation/matter interaction; concerning the use of the γ irradiator as proceed of phosphoric acid purification by the degradation of di butyl phthalate (DBP). Studies of the interaction of γ radiation with phosphoric acid solutions polluted by an organic matter concern the study of the influence of some parameters such as: dose rate (0.5–35 kGy), initial concentration (50–500 mg/L) of the pollutant, pH and % in P2O5 on the degradation of organic matter by γ irradiation. The reactions followed pseudo first order kinetics for different initial concentrations. The results made it possible to say that the degradation of di butyl phthalate by γ irradiation is dependent on the amount of the concentration of DBP and pH. The G-values decreased with absorbed doses, and increased with higher initial concentrations.Purification of phosphoric acid by γ radiation does not degrade the quality of this acid.


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