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Animals : An Open Access Journal From... May 2024To address the safety problems posed by the transportation of boar semen using LN, this study was conducted on the short-term storage of frozen boar semen in dry ice...
To address the safety problems posed by the transportation of boar semen using LN, this study was conducted on the short-term storage of frozen boar semen in dry ice (-79 °C). Boar semen frozen in LN was transferred to dry ice, kept for 1 day, 3 days, 5 days, 7 days, or 8 days, and then moved back to LN. The quality of frozen semen stored in LN or dry ice was determined to evaluate the feasibility of short-distance transportation with dry ice. The results showed that 60 °C for 8 s was the best condition for thawing frozen semen stored in dry ice. No significant differences in spermatozoa motility, plasma membrane integrity, or acrosome integrity were observed in semen after short-term storage in dry ice compared to LN ( > 0.05). There were no significant changes in antioxidant properties between storage groups either ( > 0.05). In conclusion, dry ice could be used as a cold source for the short-term transportation of frozen boar semen for at least 7 days, without affecting sperm motility, morphological integrity, or antioxidant indices.
PubMed: 38791640
DOI: 10.3390/ani14101422 -
International Journal of Molecular... Aug 2023In Antarctica, ice-free areas can be found along the coast, on mountain peaks, and in the McMurdo Dry Valleys, where microorganisms well-adapted to harsh conditions can...
In Antarctica, ice-free areas can be found along the coast, on mountain peaks, and in the McMurdo Dry Valleys, where microorganisms well-adapted to harsh conditions can survive and reproduce. Metabolic analyses can shed light on the survival mechanisms of Antarctic soil communities from both coastal sites, under different plant coverage stages, and inner sites where slow-growing or dormant microorganisms, low water availability, salt accumulation, and a limited number of primary producers make metabolomic profiling difficult. Here, we report, for the first time, an efficient protocol for the extraction and the metabolic profiling of Antarctic soils based on the combination of NMR spectroscopy and mass spectrometry (MS). This approach was set up on samples harvested along different localities of Victoria Land, in continental Antarctica, devoid of or covered by differently developed biological crusts. NMR allowed for the identification of thirty metabolites (mainly sugars, amino acids, and organic acids) and the quantification of just over twenty of them. UPLC-MS analysis identified more than twenty other metabolites, in particular flavonoids, medium- and long-chain fatty acids, benzoic acid derivatives, anthracenes, and quinones. Our results highlighted the complementarity of the two analytical techniques. Moreover, we demonstrated that their combined use represents the "gold standard" for the qualitative and quantitative analysis of little-explored samples, such as those collected from Antarctic soils.
Topics: Soil; Antarctic Regions; Pilot Projects; Chromatography, Liquid; Tandem Mass Spectrometry; Metabolomics
PubMed: 37569716
DOI: 10.3390/ijms241512340 -
Journal of Dairy Science Nov 2023The distribution of phospholipids (PL) within the fat and serum phase of ice cream manufacturing was evaluated through partition coefficients (K) after mixing,...
The distribution of phospholipids (PL) within the fat and serum phase of ice cream manufacturing was evaluated through partition coefficients (K) after mixing, pasteurization, freezing, and hardening. Ice creams containing about 40.41 ± 3.45 (± standard deviation; control formulation) and 112.29 ± 9.06 (enriched PL formulation) mg of PL per g of fat were formulated with nonfat dry milk and β-serum, respectively. Overall, the K were lower than 1, indicating that the PL were predominantly found in the fat phase, and only a small amount was left in the serum and sediment. Confocal micrographs visually confirmed this generalization. The addition of PL significantly increased the viscosity of the mixes between 4- and 9-fold, depending on the shear rate. Additionally, mixes containing high PL exhibited higher yield stress than those formulated with low PL (0.15 ± 0.09 and 0.016 ± 0.08 Pa, respectively). Ice creams with high PL delayed the onset of meltdown and exhibited a slower rate of a meltdown than low-PL ice creams (18.53 ± 0.57 and 14.83 ± 0.85 min, and 1.01 ± 0.05 and 0.71 ± 0.04% min, respectively). This study provides useful guidelines for manufacturing ice cream enriched in milk PL. Additionally, the use of β-serum, a byproduct stream, as a source of PL is illustrated. The development will require studying the sensorial description of the product as well as consumer acceptance.
PubMed: 37641266
DOI: 10.3168/jds.2022-23145 -
Journal of Oral and Maxillofacial... 2023The process of decoverslipping is often required in a laboratory to review or examine an older slide which tends to fade over time, making it almost impossible to use it...
BACKGROUND
The process of decoverslipping is often required in a laboratory to review or examine an older slide which tends to fade over time, making it almost impossible to use it for research or study purposes. The sections then need to be re-stained which can only be done after removing the coverslip. The traditional method of decoverslipping using xylene is a time-consuming process. Various methods have been used in the past; however, none were found to be completely effective. Dry ice, the solid form of carbon dioxide, is an easily available, cheap cooling agent with a low freezing temperature (-78.5°C) which was evaluated for its efficacy in decoverslipping process, as an alternative to xylene.
MATERIALS AND METHOD
64 faded haematoxylin and eosin (H&E)-stained histopathology slides were randomly selected and segregated, according to duration of year, into eight major groups. Each group was further divided into four subgroups according to the time that the slides were subjected for decoverslipping. The slides were placed on dry ice and the time was set. Once the coverslip was removed, the slides were placed in xylene to remove any residual mountant. The tissue sections were evaluated for physical disfigurement followed by re-staining with H&E to check for any change in tissue morphology.
RESULT
The mean time taken for removal of coverslip using dry ice was 35 seconds.
CONCLUSION
This technique is easy, fast, and effective, with no tissue loss or compromise in staining quality, thereby preventing xylene toxicity and its effect on the environment.
PubMed: 38033942
DOI: 10.4103/jomfp.jomfp_332_22 -
Frontiers in Microbiology 2023The Antarctic McMurdo Dry Valleys are geologically diverse, encompassing a wide variety of soil habitats. These environments are largely dominated by microorganisms,...
INTRODUCTION
The Antarctic McMurdo Dry Valleys are geologically diverse, encompassing a wide variety of soil habitats. These environments are largely dominated by microorganisms, which drive the ecosystem services of the region. While altitude is a well-established driver of eukaryotic biodiversity in these Antarctic ice-free areas (and many non-Antarctic environments), little is known of the relationship between altitude and microbial community structure and functionality in continental Antarctica.
METHODS
We analysed prokaryotic and lower eukaryotic diversity from soil samples across a 684 m altitudinal transect in the lower Taylor Valley, Antarctica and performed a phylogenic characterization of soil microbial communities using short-read sequencing of the 16S rRNA and ITS marker gene amplicons.
RESULTS AND DISCUSSION
Phylogenetic analysis showed clear altitudinal trends in soil microbial composition and structure. Cyanobacteria were more prevalent in higher altitude samples, while the highly stress resistant Chloroflexota and Deinococcota were more prevalent in lower altitude samples. We also detected a shift from Basidiomycota to Chytridiomycota with increasing altitude. Several genera associated with trace gas chemotrophy, including and , were widely distributed across the entire transect, suggesting that trace-gas chemotrophy may be an important trophic strategy for microbial survival in oligotrophic environments. The ratio of trace-gas chemotrophs to photoautotrophs was significantly higher in lower altitude samples. Co-occurrence network analysis of prokaryotic communities showed some significant differences in connectivity within the communities from different altitudinal zones, with cyanobacterial and trace-gas chemotrophy-associated taxa being identified as potential keystone taxa for soil communities at higher altitudes. By contrast, the prokaryotic network at low altitudes was dominated by heterotrophic keystone taxa, thus suggesting a clear trophic distinction between soil prokaryotic communities at different altitudes. Based on these results, we conclude that altitude is an important driver of microbial ecology in Antarctic ice-free soil habitats.
PubMed: 37555066
DOI: 10.3389/fmicb.2023.1203216 -
International Journal of Circumpolar... Dec 2023A field study was conducted to examine the vulnerability of military divers to non-freezing cold injury (NFCI) during Arctic ice-diving operations. Participants were...
A field study was conducted to examine the vulnerability of military divers to non-freezing cold injury (NFCI) during Arctic ice-diving operations. Participants were instrumented with temperature sensors on the back of their hands and on the bottom of their big toe for each dive to measure cooling of their extremities. While NFCI was not diagnosed in any of the participants during this field study, the data indicate that the feet were particularly vulnerable during the dives given that they were mostly in a temperature zone that could cause pain and performance decrements. The data also show that for short term dives, the dry and wet suits with wet gloves in both configurations were thermally more comfortable for the hands than the dry suit with dry glove configuration; however, the latter would be more protective against potential NFCI during longer dives. Features such as hydrostatic pressure and repetitive diving that are unique to diving but not previously considered as risk factors for NFCI are examined herein and warrant deeper investigation given that symptoms of NFCI might be mistaken as decompression sickness.
Topics: Humans; Diving; Cold Temperature; Temperature; Arctic Regions; Extremities
PubMed: 36966493
DOI: 10.1080/22423982.2023.2190488 -
Cryobiology Mar 2024Cryopreserved semen is routinely shipped in liquid nitrogen. Dry ice could serve as an alternative coolant, however, frozen storage above liquid nitrogen temperatures...
Cryopreserved semen is routinely shipped in liquid nitrogen. Dry ice could serve as an alternative coolant, however, frozen storage above liquid nitrogen temperatures (LN2, -196 °C) may negatively affect shelf-life and cryosurvival. In this study, we determined critical temperatures for storage of cryopreserved stallion sperm. We evaluated: (i) effects of cooling samples to different subzero temperatures (-10 °C to -80 °C) prior to storing in LN2, (ii) stability at different storage temperatures (i.e., in LN2, dry ice, -80 °C and -20 °C freezers, 5 °C refrigerator), and (iii) sperm cryosurvival during storage on dry ice (i.e., when kept below -70 °C and during warming). Furthermore, (iv) we analyzed if addition of synthetic polymers (PVP-40, Ficoll-70) modulates ice crystallization kinetics and improves stability of cryopreserved specimens. Sperm motility and membrane intactness were taken as measures of cryosurvival, and an artificial insemination trial was performed to confirm fertilizing capacity. We found that adding PVP-40 or Ficoll-70 to formulations containing glycerol reduced ice crystal sizes and growth during annealing. Post-thaw sperm viability data indicated that samples need to be cooled below -40 °C before they can be safely plunged and stored in LN2. No negative effects of relocating specimens from dry ice to LN2 and vice versa became apparent. However, sample warming above -50 °C during transport in dry ice should be avoided to ensure preservation of viability and fertility. Moreover, addition of PVP-40 or Ficoll-70 was found to increase sperm cryosurvival, especially under non-ideal storage conditions where ice recrystallization may occur.
Topics: Male; Animals; Horses; Cryopreservation; Semen; Dry Ice; Ice; Polymers; Crystallization; Ficoll; Semen Preservation; Sperm Motility; Spermatozoa; Nitrogen; Povidone
PubMed: 38295927
DOI: 10.1016/j.cryobiol.2024.104852 -
JDS Communications Nov 2023The objective of this research was to evaluate the suitability of whey permeate powder for ice cream. Three white mixes were formulated with equivalent total solids,...
The objective of this research was to evaluate the suitability of whey permeate powder for ice cream. Three white mixes were formulated with equivalent total solids, fat, and carbohydrates, but different concentrations of lactose and added sugar. Vanilla ice creams contained either reduced lactose (RL, 3.8% lactose and 17% added sugar), standard lactose (SL, 5.8%; 15%), or high lactose (HL, 7.8%; 13%). Trained panelists evaluated 8 body and texture, and 6 flavor characteristics through 10 mo of storage. All ice creams maintained low mean scores (<4.0/15.0 cm) for crumbly, lacks freshness, nonfat dry milk flavor, and whey, and moderate mean scores (5.0-8.3/15.0 cm) for gummy, melt rate, melt viscosity, sweet, and vanilla flavor for 10 mo. In mo 1 and 10, consumers in Iowa (n = 94, n = 55) and in mo 4 and 6, consumers in Kansas (n = 44; n = 56) rated the acceptability of the ice creams. Overall acceptability, flavor, and texture acceptability for products did not significantly differ until mo 10, when HL mean scores decreased lower than SL ice cream mean scores. The lower scores are attributed to crumbly and sandy texture defects, noted by trained panelists, only for HL ice cream stored 10 mo. The research demonstrates that whey permeate powder can be used to produce ice creams of acceptable quality for up to 10 mo.
PubMed: 38045891
DOI: 10.3168/jdsc.2023-0382 -
Pharmaceutics Aug 2023In this work, a non-isothermal pore network (PN) model with quasi-steady vapor transport and transient heat transfer is presented for the first time for the application...
In this work, a non-isothermal pore network (PN) model with quasi-steady vapor transport and transient heat transfer is presented for the first time for the application of primary freeze drying. The pore-scale resolved model is physically based and allows for the investigation of correlations between spatially distributed structure and transport conditions. The studied examples were regular PN lattices with a significantly different structure, namely a spatially homogeneous PN, also denoted as monomodal PN, and a PN with significant structure variation, referred to as bimodal PN because of its bimodal pore size distribution. The material properties selected for the solid skeleton in this study are equivalent to those of maltodextrin. The temperature ranges applied here were -28 °C to -18 °C in the PN and -42 °C in the surrounding environment. The environmental vapor pressure was 10 Pa. The PNs were dried with constant temperature boundary conditions, and heat was transferred at the top side by the vapor leaving the PN. It is shown how the structural peculiarities affect the local heat and mass transfer conditions and result in a significant widening of the sublimation front in the case of the bimodal PN. The possibility of spatially and temporally resolved front structures is a unique feature of the PN model and allows the study of situations that are not yet described by classical continuum approaches, namely heterogeneous frozen porous materials. As demonstrated by the thin layers studied here, the pore-scale simulations are of particular interest for such situations, such as in lyomicroscopes or collagen scaffolds, where a length-scale separation between dry and ice-saturated regions is not possible.
PubMed: 37631345
DOI: 10.3390/pharmaceutics15082131 -
Health Science Reports Sep 2023Winter endurance athletes have a high prevalence of exercise-induced bronchoconstriction (EIB) and asthma, probably due to repeated and prolonged inhalation of cold and...
BACKGROUND AND AIMS
Winter endurance athletes have a high prevalence of exercise-induced bronchoconstriction (EIB) and asthma, probably due to repeated and prolonged inhalation of cold and dry air. Heat- and moisture-exchanging devices (HME) warm and humidify inhaled air and prevent EIB. The aim of this study was to share cross-country skiers and biathletes' experiences of training and competition in low temperatures, views on temperature limits, usage of HME, and consequences of cold exposure on their health.
METHODS
Eleven Swedish World Championship or Olympic medalists in cross-country skiing and biathlon were interviewed and transcripts were analyzed using qualitative content analysis.
RESULTS
Participants described how cold temperatures predominantly affected the airways, face, and extremities. During training, extreme cold was managed by choosing warmer clothing, modification of planned sessions, use of HME, delaying training, or changing location. In competition, participants described limited possibility for such choices and would prefer adjustment of existing rules (i.e., more conservative temperature limits), especially since they understood elite skiing in low temperatures to present an occupational hazard to their health. Participants had at times used HMEs during training in cold environments but described mixed motives for their use-that HMEs warm and humidify cold inhaled air but introduce additional resistance to breathing and can cause problems due to mucus and ice build-up. Skiers also perceived that they had become more sensitive to cold during the latter part of their careers.
CONCLUSIONS
The present study gives a unique insight into the "cold" reality of being an elite athlete in skiing and biathlon. Cold exposure results in negative health consequences that are preventable, which means that rules must be followed, and organizers should acknowledge responsibility in protecting athletes from occupational hazards. Development of evidence-based guidelines for protection of athletes' respiratory health should be a focus for future translational research.
PubMed: 37662540
DOI: 10.1002/hsr2.1511