Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “REFRIGERATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
PubMed2002

Potency, sterility and immunogenicity of rabies tissue culture vaccine after reconstitution and refrigerated storage for 1 week.

The economical Thai Red Cross intradermal (TRC-ID) post-exposure rabies treatment schedule is now widely used in Asia. However, directives from WHO and manufacturers mandated that the vaccine be used within 8h after reconstitution of the freeze-dried product. This limits the use of TRC-ID to large animal bite clinics that see several rabies exposed patients daily. This study demonstrated that refrigerated purified chick embryo and Vero cell rabies vaccines can be stored safely for up to 7 days after reconstitution; allowing use of this treatment regimen in clinics that see few rabies exposed subjects. A large project applying this method in a Northern Thai canine rabies endemic province is now in place.

Animals↗
PubMed2005

Evidence for the involvement of arabinoxylan and xylanases in refrigerated dough syruping.

The relationship between syruping in refrigerated doughs upon prolonged storage and different aspects of arabinoxylan (AX) hydrolysis was investigated using Triticum aestivum xylanase inhibitor (TAXI) and different xylanases in the dough formula. Dough characteristics were evaluated with strong emphasis on the AX population and its fate as a function of storage time. Selective reduction of part of the flour endogenous xylanase activity in dough by added TAXI reduced dough syruping after 12 and 20 days of storage by 50%, providing straightforward evidence for the involvement of xylanases and, thus, AX in the syruping phenomenon. Addition of xylanases with different inhibitor sensitivities [an inhibition-sensitive Bacillus subtilis xylanase (XBS(i)) as well as a noninhibited mutant (XBS(ni)) thereof] to dough confirmed the importance of xylanases in dough syruping, on one hand, and the power of wheat flour TAXI to constitute a significant barrier against xylanase-mediated dough syruping, on the other hand. Use of xylanases with different substrate selectivities [an Aspergillus aculeatusxylanase (XAA) versus XBS(ni)] showed degradation of water-extractable AX (WE-AX) and solubilized AX to low molecular weight molecules rather than the conversion of water-unextractable AX (WU-AX) to high molecular weight water extractable components to be the main factor influencing dough syruping.

Bread↗
PubMed2006

Carotenoid profile modification during refrigerated storage in untreated and pasteurized orange juice and orange juice treated with high-intensity pulsed electric fields.

A comparative study was made of the evolution and modification of various carotenoids and vitamin A in untreated orange juice, pasteurized orange juice (90 degrees C, 20 s), and orange juice processed with high-intensity pulsed electric fields (HIPEF) (30 kV/cm, 100 micros), during 7 weeks of storage at 2 and 10 degrees C. The concentration of total carotenoids in the untreated juice decreased by 12.6% when the juice was pasteurized, whereas the decrease was only 6.7% when the juice was treated with HIPEF. Vitamin A was greatest in the untreated orange juice, followed by orange juice treated with HIPEF (decrease of 7.52%) and, last, pasteurized orange juice (decrease of 15.62%). The decrease in the concentrations of total carotenoids and vitamin A during storage in refrigeration was greater in the untreated orange juice and the pasteurized juice than in the juice treated with HIPEF. During storage at 10 degrees C, auroxanthin formed in the untreated juice and in the juice treated with HIPEF. This carotenoid is a degradation product of violaxanthin. The concentration of antheraxanthin decreased during storage, and it was converted into mutatoxanthin, except in the untreated and pasteurized orange juices stored at 2 degrees C.

Beverages↗
PubMed2001

The influence of packaging methodology on the microbiological and fatty acid profiles of refrigerated African catfish fillets.

AIMS: The shelf-life of refrigerated catfish fillets was determined at 2 degrees C, to simulate retail conditions, using two types of packaging materials, vacuum packing (VP) and oxygen permeable packaging (OPP). METHODS AND RESULTS: Representative samples (n=5) from both types of packaging methods were drawn at random every 2 d until a microbiological count of 106 cfu g-1 was reached. Samples were pooled and screened microbiologically using standard methods. Fatty acid analyses of total lipids, neutral lipid, glycolipid and phospholipid fractions were also conducted, to determine at which point the fish was regarded as spoiled and which packaging method provided a longer shelf-life. OPP limits storage to a maximum of 4 d (aerobic plate count of 8.2 x 105 cfu g-1), whereas VP extends the shelf-life of the fillets to between 6 and 8 d (aerobic plate count of 9.2 x 104 cfu g-1 and 1.66 x 106 cfu g-1, respectively). Similarly, coliform counts increased with time; however, packaging material had no statistical influence thereon. CONCLUSION: Until d 13, when the experiment was terminated, no deterioration in lipid composition of the various fractions was noted. SIGNIFICANCE AND IMPACT OF THE STUDY: An extended shelf-life microbiologically-speaking, for potential processors, could thus be obtained by using VP instead of OPP.

Animals↗
PubMedDate not supplied

The effect of delayed refrigeration on red blood cells, platelet concentrates and cryoprecipitable AHF.

The effect of delaying blood processing for six hours while maintaining it at ambient temperature was investigated. Blood drawn from volunteers on two occasions was processed immediately (I) or after a six-hour delay (D). The effects of the delay on the efficacy and safety of red blood cells, platelet concentrates and cryoprecipitable AHF were studied. There was a more rapid decrease in 2,3-DPG in the delayed group during 21 days of refrigerated storage. ATP levels declined at similar rates. 24-hour survival of 51CR-labeled autologous cells was slightly better (p = .05) in the (I) group but excellent for both. Total platelets, per cent recovery and pH at 72 hours were identical for both groups. All cultures were sterile. There was no difference in total AHF recovered or per cent recovery between the two groups. To increase the availability of blood components, a six-hour processing delay seems warranted.

Blood Platelets↗
PubMed2002

Comparison of carbon dioxide versus refrigerant spray to determine pulpal responsiveness.

There is little evidence for which cold delivery method is most accurate in determining pulp responsiveness. This study compared carbon dioxide dry ice sticks (CO2) versus refrigerant spray (RS) to generate a patient response from different types of teeth restored to varying degrees. Fifteen human patients were selected. In each quadrant, three teeth were identified and the restoration type recorded. Blindfolded patients were randomly tested with either CO2 or RS in a crossover design at two different sessions. Responsiveness was recorded as yes/no and the interval (in seconds) from application to response was determined. Results showed that (a) CO2 and RS were equivalent in producing a pulpal response regardless of tooth and presence of restoration, and (b) CO2 took significantly (p < 0.05) longer to evoke a response than RS using paired t tests. In conclusion, RS and CO2 were equivalent in determining pulpal responsiveness, but the elicited response from RS was faster.

Adult↗
PubMed2003

Self-organization from structural refrigeration.

The self-organization of a classical current is studied, in an exactly solvable model where both the quantum statistics over microhistories of particles, and the macroscopic phenomenology, can be computed in closed form. It is shown that for thermodynamically reversible systems, the Jaynes formulation of statistical mechanics naturally extends to include explicit macroscopic dynamics and heterogeneities in temperature, while preserving the structure of partition functions, effective potentials, and ground states of the equilibrium theory. Self-organization in such reversible systems is constrained by entropy transport through engine and refrigeration cycles, rather than by diffusion in gradients. Limitations in the ability to decompose such systems sensibly into components with additive entropies, and in the extrapolation of entropy functions from equilibrium forms, are discussed with examples.

Journal Article↗
PubMed2001

Opto-thermionic refrigeration in semiconductor heterostructures.

Combining the ideas of laser cooling and thermionic cooling, we have proposed an opto-thermionic cooling process, and investigated its cooling effect caused by the light emission from a quantum well embedded into a semiconductor pn junction. For a GaAs/AlGaAs opto-thermionic refrigerator in which the Auger recombination is the major nonradiative process, cooling can be achieved in a finite range of bias voltage. Using the measured values of the Auger coefficient, our calculated cooling rate is at least several watts/cm(2).

Journal Article↗
PubMed2006

Brownian refrigerator.

Onsager symmetry implies that a Brownian motor, driven by a temperature gradient, will also perform a refrigerator function upon loading. We analytically calculate the corresponding heat flow for an exactly solvable microscopic model and compare it with molecular dynamics simulations.

Journal Article↗
PubMed1986

In vitro effect on stored red blood cells and platelets after a 15-hour delayed refrigeration of whole blood prior to component preparation in CPD-AD.

We extended the time of keeping whole blood at 20-24 degrees C to 15 h (overnight) after phlebotomy for preparing platelet concentrates. We have evaluated the in vitro characteristics of platelets and blood cells prepared from whole blood drawn into CPD-AD, an anticoagulant containing 0.4 mM adenine and 1.5 times more dextrose than CPD. We studied in vitro red cell and platelet function of blood cooled either within 4 h after collection or after a 15-hour delay. In vitro platelet function measured as hypotonic shock reaction, aggregation response to ADP and collagen and 14C-serotonin uptake were not significantly different after preparation and after a 5-day storage period. Units held at room temperature for 15 h after blood collection exhibited a level of 2,3-DPG that was 45% of that exhibited by red cells held for 15 h at 1-6 degrees C. All other in vitro parameters of red cell concentrates measured during 35 days of storage were not significantly different. Based on these in vitro data blood drawn into CPD-AD might be kept up to 15 h at room temperature prior to refrigeration in order to prepare platelet concentrates.

2,3-Diphosphoglycerate↗
PubMed1997

An organic refrigerant for cryosurgery: fact or fiction?

Dimethylether/propane is an organic substance used as a refrigerant in a new cryodelivery system marketed for the treatment of warts. The objective was first to determine the temperatures achieved by this delivery system, both at the end of the applicator and in the tissues and, second, to compare with liquid nitrogen delivered via standard cryospray equipment (CryAC). Temperature probes were used to measure temperature 1 mm below the epidermis of pig trotters after freezing with the two delivery systems for 20 and 40 s. After freezing with dimethylether/propane, results showed tissue temperatures were 3 degrees C at 20 s and 0 degree C at 40 s. Freezing with liquid nitrogen achieved -20 degrees C at 20 s and -57 degrees C at 40 s. It was concluded that dimethylether/propane does not achieve tissue temperatures below 0 degree C and is not recommended in the use of malignant or premalignant lesions.

Animals↗
PubMed2000

Use of electrodynamic drivers in thermoacoustic refrigerators

Some issues involved in matching electrodynamic drivers to thermoacoustic refrigerators are examined using an equivalent circuit model. Conclusions are that the driver should be chosen to have a large product (Bl)2/(ReRm); the suspension stiffness should be chosen to make the combined impedance of the mechanical and acoustical parts of the system entirely real at the operating frequency; and the piston area should be selected to maximize electroacoustic efficiency, or other desired parameter, by matching the acoustic load to the optimum mechanical load for the particular driver. Alternately, if the piston area is fixed, the operating frequency can be adjusted to make this same match.

Journal Article↗
PubMed1998

Footwall refrigeration along a detachment fault: implications for the thermal evolution of core complexes

Oxygen isotope compositions of epidote and quartz from chloritic breccias that underlie the detachment fault in the metamorphic core complex of the Whipple Mountains yielded quartz-epidote fractionations that range from 4.1 to 6.4 per mil and increase systematically toward the fault. These fractionations give mean temperatures that decrease from approximately 432 degrees C at 50 meters below the fault to approximately 350 degrees C at 12 meters below the fault. This extreme thermal gradient of 82 degrees C over 38 meters (2160 degrees C per kilometer) is best explained by advective heat extraction by means of circulating surface-derived fluids. Models of lithospheric extension consider only conductive cooling resulting from tectonic denudation and thus require revision to include fluid-induced fault-zone refrigeration.

Journal Article↗