Hr Of Storage Research Articles

Effects of Injectable Solutions on the Quality of Monocyte-Derived Dendritic Cells for Immunotherapy.

Therapeutic vaccines based on monocyte-derived dendritic cells have been shown to be promising strategies and may act as complementary treatments for viral infections, cancers, and, more recently, autoimmune diseases. Alpha-type-1-polarized dendritic cells (aDC1s) have been shown to induce type-1 immunity with a high capacity to produce interleukin-12p70 (IL-12p70). In the clinical use of cell-based therapeutics, injectable solutions can affect the morphology, immunophenotypic profile, and viability of cells before delivery and their survival after injection. In this sense, preparing a cell suspension that maintains the quality of aDC1s is essential to ensure effective immunotherapy. In the present study, monocytes were differentiated into aDC1s in the presence of IL-4 and GM-CSF. On day 5, the cells were matured by the addition of a cytokine cocktail consisting of IFN-α, IFN-γ, IL-1β, TNF-α, and Poly I:C. After 48 hr, mature aDC1s were harvested and suspended in two different solutions: normal saline and Ringer's lactate. The maintenance of cells in suspension was evaluated after 4, 6, and 8 hr of storage. Cell viability, immunophenotyping, and apoptosis analyses were performed by flow cytometry. Cellular morphology was observed by electron microscopy, and the production of IL-12p70 by aDC1s was evaluated by ELISA. Compared with normal saline, Ringer's lactate solution was more effective at maintaining DC viability for up to 8 hr of incubation at 4 or 22°C.

Use of Orange Husk and Watercress ( Eruca sativa ) Seed Extracts as Antimicrobial Natural Preservative for Fruit Juices

The natural preservative for foods and juices are become mandatory required instead of artificial or chemical preservatives. That the main goal of our present study. The study included making water and alcoholic extractions of orange husk and Eruca Sativa seeds. The inactivation`s efficacy of these extracts of 150 , 250 and 400 mg/ml concentrations against some pathogenic bacteria such as Escherichia coli, Staphylococcus aurous, and Streptococcus pyogenes were done by the disc assay method and compared the results of inactivation with Azithromycin antibiotics. Also, the bioactive compounds of these extracts were determined. Orange and pomegranate juice samples which treated with the aquatic extract 400 mg / ml of orange husk and extract of Eruca Sativa seeds after 24 hr storage time were sensory evaluated by specialists and teachers to special sensory factors. The results were shown that the aquatic and alcoholic extracts of Eruca Sativa seeds have the following active compounds, resin, tannins, comarins, alkaloids, flavons, phenols,glycosides and saponins. However, the orang husk extracts have the same compounds except Comorians, and glycosides were absent. The results of antibacterial efficacy of the aquatic extract of the Eruca Sativa seeds of 400 mg/ml shown superior significant bacterial inactivation compared to the orang husk extracts and to the Azithromycin antibiotics with 0.05 probability . The results of the sensory evaluation showed that the orange and pomegranate juice samples which were treated with 400mg/ml water extract of orange husk gave higher scores than the treatment of Eruca Sativa seeds extracts .
 

Microencapsulation of de‐glycosylated mulberry ( Morus alba L.) fruit extract through double‐layered multiple emulsions of pectic polysaccharide extracted from Ulmus davidiana and soy protein isolate

Our objectives were to (1) encapsulate de-glycosylated mulberry fruit extract (dg-MFE) through double-layered multiple emulsions of pectic polysaccharide from Ulmus davidiana (UDP) and soy protein isolate (SPI) by spray dryer and (2) investigate the physicochemical, storage, and in vitro digestibility properties of the encapsulated powders. Four different concentrations of UDP (0, 0.5, 1.0, 1.5, and 2.0 g UDP per 3.0 g SPI) were prepared for microencapsulation of dg-MFE. HR FE-SEM morphology of encapsulated powders became spherical with an increase in the concentrations of UDP. Due to the production of thicker layers by the formation of electrostatic interactions between small positively charged groups of SPI and negatively charged groups of UDP, particle sizes and storage stability of the encapsulated powders prepared by SPI-UDP were improved. In vitro digestion study indicated that the release of dg-MFE was effectively controlled by a protective coating of SPI-UDP under the simulated gastric and intestinal fluid. Novelty impact statement This study was investigated to enhance the stability of de-glycosylated mulberry (Morus alba L.) fruit extract during the storage and digestion process and to develop a slow-release targeted delivery system to the colon. Based on HR FE-SEM analysis, encapsulation efficiency, storage stability, and simulated gastrointestinal digestion analysis, these results demonstrated that the encapsulated powders prepared by soy protein isolate-Ulmus davidiana complexes were found to be better coating materials for microencapsulation of de-glycosylated mulberry fruit extract than those prepared by only soy protein isolate. Therefore, this study provides a promising technology to protect bioactive compounds during storage and passing through the upper gastrointestinal tract.

Physicochemical properties, consumer acceptability and microbial quality of saccharified sweet potato juice preserved with lemon

In this study, saccharified sweet potato juice preserved with lemon juice at different concentrations of 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0%, was formulated. Physicochemical, sensory, and microbial quality of the juice stored for 48 hr were analyzed. The pH and brix values decreased, but the total titratable acidity increased as a result of added lemon juice. There was a significant amount of Vitamin-C, B6, and B9 in the samples, while the antinutritional component (phytate, saponin and tannin) of the juice was generally low compared with the generally acceptable limit. The sensory results showed that the sample with 2.5% lemon juice was the most accepted. The rate of microbial growth within a 48 hr storage period decreased with the addition of lemon and there was no record of fecal coliform bacteria growth. Lemon can be used as a source of natural preservatives and a substitute for artificial preservatives for sweet potato juice.

Assessment of the effect of marination with broccoli (Brassica oleracea var. italica) juice and balsamic vinegar on tenderness and quality of beefsteak.

Due to the increasing demand for natural foods with fewer artificial additives, broccoli is considered by the consumers and researchers due to its taste, nutritional values and biochemical components. Therefore, this research was conducted to investigate the effect of broccoli juice and balsamic vinegar on the physicochemical and textural attributes of the beefsteak aimed at tenderizing it and decreasing the ageing period. Experiments were carried out through marinating the beefsteak with three different treatments containing 3.00 units protease g-1 beefsteak of broccoli juice and 10.00% (v/w) of balsamic vinegar during 48 hr storage at 4.00˚C. A significant reduction in pH and Warner-Bratzler shear force as well as the increase in myofibrillar fragmentation index and myofibrillar protein solubility were obtained showing that the beefsteak was tendered in the presence of broccoli juice and broccoli juice+balsamic vinegar. Scanning electron microscopy images showed the destruction of endomysium collagen and sarcolemma areas of muscle filaments in the above-mentioned treatments. The electrophoretic analysis of isolated myofibrillar proteins indicated that the rate of troponin-T breakdown was quicker in all treatments compared to the control and its degradation was progressively obvious with 20.00 and 28.00 kDa protein bands in mentioned treatments. Based on the results, marinades of broccoli juice and balsamic vinegar could be utilized as a beneficial additive for improving beefsteak tenderness.

Comparative study on the stability of selected Neutral electrolyzed waters and their sanitizing effect on organic fresh‐cut lettuce ( Lactuca sativa Var. crispa L)

In this study, two near neutral pH electrolyzed water (NEW1 produced by redirecting of the catholyte solution back to the anode chamber and NEW2 produced by NaCl and NaHCO3 as electrolyte) and control (NEW0, produced by commercial unit) were evaluated for their stability during 75 hr storage at 7°C. The physicochemical properties, bactericidal efficiencies, and sanitizing effects on organic fresh-cut lettuce of them were compared. The results showed that NEW2 was more stable than NEW1 and NEW0 during storage. The free available chlorine of it increased by approximately 35% after the storage. And, all three NEWs showed decreased bactericidal effects compared with that before the storage. In addition, all of them were effective against Escherichia coli and Listeria innocua Seeliger inoculated on organic fresh-cut lettuce, with 1.19–1.40 and 0.92–1.21 log CFU/g reductions, respectively. In terms of physicochemical parameters, there were no significant differences among different treatments. Practical applications Neutral electrolyzed waters (NEW) are a kind of potential organic compatible sanitizer and satisfy the urgent market need. But the stability of NEW has significant effects on their bactericidal activity. The results of the comparative study of different NEWs produced by developed NEW-producing unit could provide valuable reference data of NEWs regarding their stability during storage and the reduction of the risk from foodborne pathogens in a future application.

Oral administration of royal jelly may improve the preservation of rooster spermatozoa.

The aim of the present study was to investigate the effect of dietary supplementation of royal jelly (RJ) on liquid and frozen storage of rooster spermatozoa. Twenty-five 30-week-old of Mazandaran native breeder roosters were randomly divided into five treatments (n=5 roosters/group). Experimental treatments are designed to include a control group and various levels (0.0 (RJ0), 100 (RJ100), 200 (RJ200), 300 (RJ300) mgkg-1 BW-1 ) of royal jelly (RJ) that were fed to the roosters using force-feed method. The percentage of forward progressive motility, abnormal spermatozoa, membrane integrity and viability of spermatozoa evaluated after 24 and 48hr of cooling (at 4°C) and after the freeze-thawing process. Also, mitochondrial activity and DNA fragmentation in fresh (24hr) and post-thawed spermatozoa were assessed. The result of this study showed that the spermatozoa forward progressive motility, abnormality, membrane integrity, and viability were improved by the RJ100 group compared to the other groups after 24 and 48hr storage period at 4°C. The percentage of membrane integrity and forward progressive motility after freeze-thawing in the RJ100 group was significantly higher than the other groups, and the percentage of abnormal spermatozoa was lower. A significant decrease in semen quality parameters was seen after 24 and 48hr of refrigeration, but there was no observed change between 2 and 24hr in the RJ100. The viability percentage of spermatozoa in both RJ100 and RJ200 groups was not different. Moreover, after freeze-thawing, DNA integrity and mitochondrial activity in the RJ100 group were significantly higher than the other groups. According to our results, feeding of RJ at 100mgkg-1 BW-1 to the roosters was improved spermatozoa characteristics during liquid and cryopreservation conditions.

Effect of marinating ingredients on temperature-induced denaturation of hemoglobin and its relation to red blood spot formation in cooked chicken breast.

Red blood spot (RBS) commonly found in cooked chicken breast has caused severe economic loss as it is perceived as a sign of undercooked product. The objectives of this study were to investigate the cause of RBS as related to common ingredients used in marination, based on both chicken breast and isolated chicken hemoglobin (Hb) models. The effect of sodium chloride (NaCl), sodium tripolyphosphate (STPP), and glucose on thermal denaturation of Hb was investigated along with the extent of RBS formation in cooked marinated chicken breast. After vacuum tumbling for 65min and subsequent storage at 4°C for 20 hr, STPP and glucose were not absorbed into the center of chicken breast. However, Na+ was absorbed after 12 hr storage. The denaturation temperature (Td ) of isolated chicken Hb decreased to 65.8°C in the presence of 1.5 M NaCl, while that of the control was 69.4°C. STPP at pH 9 decreased Td of Hb to 61.4°C. The alkaline pH induced by STPP destabilized the Hb structure. RBSs were observed at 100% incidence when cooked to core temperatures of 50 and 70°C for 1min. RBSs were completely eliminated at core temperature of 85°C. The ingredients used during marination appeared to have a minimal effect on RBS formation due to their limited absorption into the chicken breast. The cooking temperature is a major factor governing RBSs, as it directly affects the denaturation of Hb.

Effect of semen extenders and storage time on quality of Muscovy duck (Cairina moschata) drake semen during the entire reproductive season.

Avian semen dilution with appropriate extender allows to prolong the fertilizing ability of sperm stored in vitro. In the present study, the impact of extenders and time of storage on morphology of Muscovy duck (Cairina moschata) drake semen were examined. Semen was collected twice a week, using male stimulation by a female method, from 12 adults (29weeks old) drakes kept individually in cages, under controlled environmental conditions. Freshly collected, pooled ejaculates were divided into three part: neat undiluted sample, and diluted 1:1 with Schramm (SCH) or Watanabe (W) extender and stored at 4°C. Morphological examination of all samples was conducted after dilution and then, after 3 and 6hr of storage. The storage of undiluted semen caused decrease (p≤.01) in live morphologically normal sperm, from 79.73% in the freshly collected ejaculates to 55.75% and to 12.12% after 3 and 6hr of storage, respectively (average calculated for the entire reproductive season). In the semen diluted with Schramm's extender the adequate values attained 86.84, 79.65 and 61.66%, and using Watanabe extender 84.77, 83.58 and 75.25%, respectively. The period of semen storage and the type of extender caused significant (p≤0,05; p≤0,01) changes in sperm morphology. The longer period of storage contributed to the decrease in number of morphologically normal sperm, whereas their content in Watanabe extender after 3 and 6hr of storage was higher (p≤.01) than in semen diluted in Schramm extender.

Effect of Gelling Agent Molecular Weight on Self-Discharge Behavior for Zinc-Air Batteries

A zinc-air battery is one of most promising advanced batteries due to its high specific energy density, low cost, and environmental friendliness. However, zinc anodes in zinc-air batteries lead to several issues including self-discharge, corrosion reaction, and hydrogen evolution reaction (HER). In this paper, viscosity of electrolyte has been controlled to suppress the corrosion reaction, HER, and self-discharge behavior. Various viscosity average molecular weights of poly(acrylic acid) (PAA) are adopted to prepare the electrolyte. The evaporation of electrolytes is proportional to the increase in molecular weight. In addition, enhanced self-discharge behavior is obtained when the gelling agent with high molecular weight is used. In addition, the zinc-air cell assembled with lower viscosity average molecular weight of PAA (Mv ~ 450,000) delivers 510.85 mAh/g and 489.30 mAh/g of discharge capacity without storage and with 6 hr storage, respectively. Also, highest capacity retention (95.78 %) is obtained among studied materials.

Effects of Electrolyte Concentration on Electrochemical Properties of Zinc-Air Batteries

The self-discharge behavior of zinc-air batteries is a critical issue induced by corrosion and hydrogen evolution reaction (HER) of zinc anode. The corrosion reaction and HER can be controlled by a gelling agent and concentration of potassium hydroxide (KOH) solution. Various concentrations of KOH solution and polyacrylic acid have been used for gel electrolyte. The electrolyte solution is prepared with different concentrations of KOH (6 M, 7 M, 8 M, 9 M). Among studied materials, the cell assembled with 6 M KOH gel electrolyte exhibits the highest specific discharge capacity and poor capacity retention. Whereas, 9 M KOH gel electrolyte shows high capacity retention. However, a large amount of hydrogen gas is evolved with 9 M KOH solution. In general, the increase in concentration is related to ionic conductivity. At concentrations above 7 M, the viscosity increases and the conductivity decreases. As a result, compared to other studied materials, 7 M KOH gel electrolyte is suitable for Zn-air batteries because of its higher capacity retention (92.00 %) and specific discharge capacity (351.80 mAh/g) after 6 hr storage.

Homogenization-resistant spermatids in testicular tissue stored under suboptimal conditions-Effect of time and temperature.

Reproductive assessments on wild animals are often hampered due to practical problems during sample collection. For example, the time between death and tissue collection as well as sample storage conditions will affect the quality of the tissue. The aim of this study was to examine the effect of less optimal, field-like conditions, that is different temperatures and variable storage time, on the quantification of homogenization-resistant spermatids in testicular tissue, using the bull as a model. One bull testis was kept in +5°C for 216hr, from which (n=68) samples were taken at different time points for storage in -20°C or +21°C. Some samples were frozen, thawed and then refrozen. The tissue was homogenized, and the number of spermatids was quantified manually with a counter chamber. Compared to the samples taken at 0hr, the number of spermatids was unchanged until 120hr storage in +5°C and in frozen samples from the same time-point. After 72-hr storage in room temperature, there was a marked drop in the number of spermatids. Refreezing of samples resulted in a markedly lower number of spermatids. Frozen samples did not have significantly decreased numbers of spermatids compared to refrigerated samples. In conclusion, different storage conditions do not seem to affect the spermatids resistance to homogenization until day 3, but if kept in cool conditions it is possible to use samples up until 5days of storage. The method is a good choice for suboptimal sampling conditions.

Carrier Dynamics Engineering for High-Performance Electron-Transport-Layer-free Perovskite Photovoltaics

Summary Electron-transport-layer-free (ETL-free) device architectures are promising designs for perovskite photovoltaics because they offer simpler configurations, low cost, and convenience for versatile optoelectronics. However, the development of ETL-free photovoltaics is hindered by their low performance. Herein, we reveal that a low electron-injection rate at the ETL-free interface is responsible for the performance loss. Moreover, we demonstrate that improving carrier lifetimes in the perovskite films can remedy the poor carrier extraction at interfaces, enabling carrier collection efficiency in ETL-free photovoltaics to approach that in ETL-containing devices. Using perovskite films with microsecond carrier lifetimes, we obtained ETL-free devices with a power conversion efficiency (PCE) of 19.5%, nearly eliminated hysteresis, and good stability. Such a PCE value is comparable to that (20.7%) of the analogous ETL-containing photovoltaics. These results offer opportunities for ETL-free architecture designs in the perovskite photovoltaics family. More importantly, this research provides a general approach to improving the performance of photovoltaics with low-injection-rate interfaces.

Cetylpyridinium chloride direct spray treatments reduce Salmonella on cantaloupe rough surfaces.

Cetylpyridinium chloride (CPC) solutions (0, 0.5, or 1.0%) were applied to cantaloupe (“Athena” and “Hale's Best Jumbo” cultivars) rind plugs, either before or after inoculation with a broth culture of Salmonella Michigan (109 CFU/mL) and held at 37°C for 1 or 24 hr. Rind plugs were diluted, shaken, and sonicated, and solutions were enumerated. Texture quality and color were evaluated over 14 days storage at 4°C after 0 and 1% CPC spray applications. A 0.5 or 1.0% (vol/vol) application of CPC after Salmonella reduced the pathogen levels between 2.34 log CFU/mL and 5.16 log CFU/mL in comparison to the control (p < .01). No differences were observed in the firmness and color of 1% CPC treated cantaloupes. Salmonella concentrations on cantaloupes, treated with 1.0% CPC, were lower after 1 hr storage as compared to 24 hr. And, Salmonella on “Athena” surfaces were more susceptible to CPC spray treatments than on “Hale's Best Jumbo.”Practical applicationsCetylpyridinium chloride (CPC) is the active ingredient of some antiseptic oral mouth rinses, and has a broad antimicrobial spectrum with a rapid bactericidal effect on gram‐positive pathogens. The spray application of CPC solutions to cantaloupe may reduce the level of Salmonella surface contamination during production from irrigation water and manure fertilizers and, during food processing by contaminated equipment and food handlers. Since the surfaces of cantaloupes are highly rough or irregular, bacteria can easily attach to these surfaces and become difficult to remove. Appropriate postharvest washing and sanitizing procedures are needed that can help control Salmonella and other pathogens on melons, especially on cantaloupes with nested surfaces. A direct surface spray application of CPC may be an alternative antimicrobial postharvest treatment to reduce pathogen contamination of cantaloupe melons, while providing an alternative to chlorine‐based solutions.

Alpha-zearalenol negatively influences ram sperm parameters during liquid storage.

This study was aimed to investigate the effects of 17 𝛽-estradiol (E2) and 𝛼-zearalenol (α-ZOL) on motility parameters, plasma membrane integrity, levels of produced nitric oxide (NO) and total antioxidant capacity of Ghezel ram sperm during the liquid storage at 4 ˚C, for various periods of time. Semen samples were collected from four rams and diluted with Tris–egg yolk extender and supplemented with E2 (100 µmol) or different concentrations of α-ZOL (100 pmol, 100 nmol and 100 µmol) at a final concentration of 200 × 106 sperm per mL. We failed to show any significant effect of E2 at 100 µmol concentration on ram’s sperm parameters while α-ZOL resulted in a significant decrease of plasma membrane integrity at 100 µmol concentration (55.40% for α-ZOL vs 62.20% for control) after 96 hr incubation. Alpha-ZOL had decreasing effect on sperm motility parameters including curvilinear velocity and average path velocity at 100 µmol concentration after 96 hr storage. Although remarkable reduction of total antioxidant capacity at high concentration of α-ZOL and long incubation time was found, however no significant changes were recorded in NO level during storage time. It was concluded that the detrimental effect of α-ZOL on ram sperm might be attributed to its induced oxidative stress and damage to the plasma membrane.

Potential of Telfairia occidentalis leaf extract as boar semen extender

The preservation of semen for Artificial insemination (AI) required the use of extender, which served as a buffer media to keep the sperm cell in good condition for fertilization. In this study, fluted pumpkin Telfairia occidentalis leaf extract (TOLE) potential as an unconventional boar semen extender was compared to Beltsville thawing solution (BTS), a conventional semen extender over a 48hr storage period. Aqueous solution of TOLE was prepared at three (3) concentration levels (25, 50 and 75%). Fresh ejaculates from boar were extended at (1:4) in TOLE solutions and BTS extender in a completely randomized design; treatments were replicated four (4) times. Extended semen was stored at 170C and evaluated for semen qualities which include pH, dead/live ratio (%) and sperm cell concentration at time intervals (0, 12, 24, 36 and 48) hrs. Extended semen was significantly (P &lt; 0.05) affected by semen extenders and storage periods for pH, and dead/live ratio (%) but sperm cell concentration (103/cm3) not (P &gt; 0.05) affected. The pH values for BTS was significantly (P &lt; 0.05) higher as compared to TOLE extenders. 75% TOLE extender had highest value (43.89%), and BTS had lowest value (12.15%) for dead/live ratio significantly (P &lt; 0.05). The pH and dead/live ratio (%) values increased over storage time in all extender. The optimum performance of TOLE as compared to BTS extender was recorded at 50% concentration of TOLE extender. TOLE showed a potential as boar semen extender, but further studies are required to validate and improve its application.

Viability of carabao (Bubalus bubalis carabanensis) epididymal sperm from post mortem testes in semen extender at refrigerated temperature

Post mortem epididymal sperm (ES) is an excellent source of germplasm for conservation of animal genetic resources. In this study, the viability of post mortem ES from carabao after collection at ambient temperature (AT) and after 24 hr and 48 hr of storage at refrigeration temperature (RT) were evaluated. ES were collected through slicing of epididymides from 7 carabaos. The mean ES volume was 0.4 ml with sperm concentration of 2.5×109 cells/ml. The mean percentage livability of fresh ES, after 24 hr and 48 hr of storage at RT were 81.93%, 65.93% and 43.7%, respectively. The mean percentage abnormalities of fresh ES, after 24 hr and 48 hr of storage at RT were 44.15%, 38.5% and 43.47%, respectively. The mean percentage motility of fresh ES, after 24 hr and 48 hr of storage at RT were 60.0%, 50.0% and 17.24%, respectively, after analysis through conventional means. Through CASA, the mean percentage motility was observed to be lower significantly at 26.12%, 37.94% and 18.32% for fresh ES, after 24 hr and 48 hr of storage at RT, respectively. The mean progressive motility of fresh ES, after 24 hr and 48 hr storage at RT were 10.02%, 16.47% and 10.87%, respectively. The results suggest that ES potential for use in fertilization studies remained viable when used immediately or after storage at RT for the first 24 hr.

In vitro Stability of Heat Shock Protein 27 in Serum and Plasma Under Different Pre-analytical Conditions: Implications for Large-Scale Clinical Studies.

The effects of storage temperatures, repeated freeze-thaw cycles, or delays in separating plasma or serum from blood samples are largely unknown for heat shock protein 27 (HSP27). We evaluated (1) the imprecision of the HSP27 assay used in this study; (2) the in vitro stability of HSP27 in blood samples stored at 4℃ for up to 6 hr with immediate and delayed serum/plasma separation from cells; and (3) the in vitro stability of HSP27 in blood samples stored at -80℃ after repeated freeze-thaw cycles. The ELISA to detect HSP27 in this study showed a within-run CV of <9% and a total CV of <15%. After 4-6 hr of storage at 4℃, HSP27 concentrations remained stable when using serum tubes irrespective of sample handling, but HSP27 concentrations decreased by 25-45% when using EDTA plasma tubes. Compared with baseline HSP27, one freeze-thaw cycle had no effect on serum concentrations. However, plasma concentrations increased by 3.1-fold after one freeze-thaw cycle and by 7.3-fold after five freeze-thaw cycles. In conclusion, serum is an appropriate biological sample type for use in epidemiological and large-scale clinical studies.

Stability of Routine Biochemical Analytes in Whole Blood and Plasma From Lithium Heparin Gel Tubes During 6-hr Storage.

The stability of biochemical analytes has already been investigated, but results strongly differ depending on parameters, methodologies, and sample storage times. We investigated the stability for many biochemical parameters after different storage times of both whole blood and plasma, in order to define acceptable pre- and postcentrifugation delays in hospital laboratories. Twenty-four analytes were measured (Modular® Roche analyzer) in plasma obtained from blood collected into lithium heparin gel tubes, after 2-6 hr of storage at room temperature either before (n = 28: stability in whole blood) or after (n = 21: stability in plasma) centrifugation. Variations in concentrations were expressed as mean bias from baseline, using the analytical change limit (ACL%) or the reference change value (RCV%) as acceptance limit. In tubes stored before centrifugation, mean plasma concentrations significantly decreased after 3 hr for phosphorus (-6.1% [95% CI: -7.4 to -4.7%]; ACL 4.62%) and lactate dehydrogenase (LDH; -5.7% [95% CI: -7.4 to -4.1%]; ACL 5.17%), and slightly decreased after 6 hr for potassium (-2.9% [95% CI: -5.3 to -0.5%]; ACL 4.13%). In plasma stored after centrifugation, mean concentrations decreased after 6 hr for bicarbonates (-19.7% [95% CI: -22.9 to -16.5%]; ACL 15.4%), and moderately increased after 4 hr for LDH (+6.0% [95% CI: +4.3 to +7.6%]; ACL 5.17%). Based on RCV, all the analytes can be considered stable up to 6 hr, whether before or after centrifugation. This study proposes acceptable delays for most biochemical tests on lithium heparin gel tubes arriving at the laboratory or needing to be reanalyzed.

Testing odorants recovery from a novel metallized fluorinated ethylene propylene gas sampling bag

Industry-standard Tedlar bags for odor sample collection from confined animal feeding operations (CAFOs) have been challenged by the evidence of volatile organic compound (VOC) losses and background interferences. Novel impermeable aluminum foil with a thin layer of fluorinated ethylene propylene (FEP) film on the surface that is in contact with a gas sample was developed to address this challenge. In this research, Tedlar and metallized FEP bags were compared for (a) recoveries of four characteristic CAFO odorous VOCs (ethyl mercaptan, butyric acid, isovaleric acid and p-cresol) after 30 min and 24 hr sample storage time and for (b) chemical background interferences. All air sampling and analyses were performed with solid-phase microextraction (SPME) followed by gas chromatography–mass spectroscopy (GC-MS). Mean target gas sample recoveries from metallized FEP bags were 25.9% and 28.0% higher than those in Tedlar bags, for 30 min and 24 hr, respectively. Metallized FEP bags demonstrated the highest p-cresol recoveries after 30-min and 24-hr storage, 96.1 ± 44.5% and 44.8 ± 10.2%, respectively, among different types of sampling bags reported in previous studies. However, a higher variability was observed for p-cresol recovery with metallized FEP bags. A 0% recovery of ethyl mercaptan was observed with Tedlar bags after 24-hr storage, whereas an 85.7 ± 7.4% recovery was achieved with metallized FEP bags. Recoveries of butyric and isovaleric acids were similar for both bag types. Two major impurities in Tedlar bags’ background were identified as N,N-dimethylacetamide and phenol, while backgrounds of metallized FEP bags were significantly cleaner. Reusability of metallized FEP bags was tested.Implications: Caution is advised when using polymeric materials for storage of livestock-relevant odorous volatile organic compounds. The odorants loss with storage time confirmed that long-term storage in whole-air form is ill advised. A focused short-term odor sample containment should be biased toward the most inert material available relative to the highest impact target odorant. Metallized FEP was identified as such a material to p-cresol as the highest impact odorant from confined animal feeding operations. Metallized FEP bags have much cleaner background than commercial Tedlar bags do. Significantly higher recoveries of methyl mercaptan and p-cresol were also observed with metallized FEP bags.