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Frontiers in Microbiology 2022Blooms of microalgae on glaciers and ice sheets are amplifying surface ice melting rates, which are already affected by climate change. Most studies on glacial...
Blooms of microalgae on glaciers and ice sheets are amplifying surface ice melting rates, which are already affected by climate change. Most studies on glacial microorganisms (including snow and glacier ice algae) have so far focused on the spring and summer melt season, leading to a temporal bias, and a knowledge gap in our understanding of the variations in microbial diversity, productivity, and physiology on glacier surfaces year-round. Here, we investigated the microbial communities from Icelandic glacier surface snow and bare ice habitats, with sampling spanning two consecutive years and carried out in both winter and two summer seasons. We evaluated the seasonal differences in microbial community composition using Illumina sequencing of the 16S rRNA, 18S rRNA, and ITS marker genes and correlating them with geochemical signals in the snow and ice. During summer, , , , and dominated surface snow algal communities, while and dominated the surface bare ice habitats. In winter, algae could not be detected, and the community composition was dominated by bacteria and fungi. The dominant bacterial taxa found in both winter and summer samples were , , , and . The winter bacterial communities showed high similarities to airborne and fresh snow bacteria reported in other studies. This points toward the importance of dry and wet deposition as a wintertime source of microorganisms to the glacier surface. Winter samples were also richer in nutrients than summer samples, except for dissolved organic carbon-which was highest in summer snow and ice samples with blooming microalgae, suggesting that nutrients are accumulated during winter but primarily used by the microbial communities in the summer. Overall, our study shows that glacial snow and ice microbial communities are highly variable on a seasonal basis.
PubMed: 35651494
DOI: 10.3389/fmicb.2022.876848 -
Journal of Diabetes Science and... Sep 2022Conflicting information is available regarding the stability of glucose concentrations in frozen plasma samples. Clinical trials could benefit from such long-term...
BACKGROUND
Conflicting information is available regarding the stability of glucose concentrations in frozen plasma samples. Clinical trials could benefit from such long-term storage because it would allow usage of a central laboratory with higher-quality laboratory analyzers in contrast to mobile analyzers in a decentralized setting.
METHODS
In this study, venous blood samples were collected in lithium-heparin gel tubes. Plasma was separated immediately after blood was drawn, and from each of the 21 plasma samples, 6 aliquots were prepared for measurement at 6 time points: immediately and after 2, 4, 6, 8, and 12 weeks. Between sampling and measurement, aliquots were stored at less than -20°C. Transport on dry ice was simulated by placing aliquots in a -80°C freezer for 5 days between weeks 8 and 12. Measurements were performed on a hexokinase-based laboratory analyzer.Average relative differences and corresponding 99% confidence intervals (CIs) were calculated between the stored aliquots' and the immediately measured aliquots' glucose concentrations. Glucose concentrations were deemed stable as long as average relative differences were ≤±2.5%.
RESULTS
Over the whole 12-weeks duration, the largest average relative difference was -1.82% (99% CI: -2.25% to -1.39%). Shorter storage durations tended to lead to less bias.
CONCLUSION
In this study, the stability of glucose concentrations in frozen plasma samples obtained with lithium-heparin gel tubes could be shown for up to 12 weeks. Future studies should be performed to assess whether this is independent of the glucose analyzer and the type of sampling tube used.
Topics: Blood Specimen Collection; Glucose; Hematologic Tests; Heparin; Humans; Lithium; Time Factors
PubMed: 33034207
DOI: 10.1177/1932296820963657 -
Journal of Chemical Health & Safety May 2023Dry ice is widely used in the chemistry research settings as an excellent coolant. Herein, we report a case study of a graduate student researcher who lost consciousness...
Dry ice is widely used in the chemistry research settings as an excellent coolant. Herein, we report a case study of a graduate student researcher who lost consciousness while retrieving 180 lbs of dry ice from a deep dry ice container. We share the details of the incident and the lessons learned from it to promote safer handling of dry ice in these situations.
PubMed: 37235060
DOI: 10.1021/acs.chas.3c00027 -
Indian Journal of Dermatology 2017The aim of this study is to formulate the best clinical practice in the diagnosis and management of chronic pruritus (CP). We searched PubMed, EMBASE, Scopus, Web of... (Review)
Review
The aim of this study is to formulate the best clinical practice in the diagnosis and management of chronic pruritus (CP). We searched PubMed, EMBASE, Scopus, Web of Science, and the WHO's regional databases, for studies on "Diagnosis and management of chronic pruritus" from January 1, 2014, to July 31, 2015. We included programmatic reports and hand-searched references of published reviews and articles. Two independent reviewers screened articles and extracted data. We screened 87 of 95 studies that contained qualitative data. Avoid: Dry climate, heat, alcohol compress, ice packs, frequent bathing and washing, intake of very hot and spicy food, intake of alcohol, contact with irritant substances, excitement, strain and stress, and allergens. Using: Mild nonalkaline soaps, moisturizers, bathing oils, lukewarm water while bathing, soft cotton clothing and night creams/lotions, relaxation therapy, autogenic training, psychosocial education, educating patients to cope with itching and scratching, and educational programs. Especially use of moisturizers is considered important. In addition, symptomatic treatment options include systemic H1 antihistamines and topical corticosteroids. Symptomatic therapy directed toward the cause (hepatic, renal, atopic, polycythemia, etc.). If refractory or cause is unknown, consider capsaicin, calcineurin inhibitors for localized pruritus and naltrexone, pregabalin, ultraviolet therapy, Cyclosporine for generalized itching. CP is quite frequent finding associated with skin and systemic diseases in the overall population. It is known to significantly affect quality life score of an individual and also adds burden on the health-care cost. A specific recommendation for treatment of CP is difficult as a result of varied and diverse possibility of underlying diseases associated with CP.
PubMed: 28216719
DOI: 10.4103/0019-5154.198036 -
Molecules (Basel, Switzerland) Apr 2016The phenolic and chromatic characteristics of a special red ice wine made from a Vitis amurensis × V. vinifera hybrid cultivar Beibinghong were studied. Results from...
The phenolic and chromatic characteristics of a special red ice wine made from a Vitis amurensis × V. vinifera hybrid cultivar Beibinghong were studied. Results from two different vintages (2013 and 2014) showed that during vinification, the phenolic acid content increased, while the level of flavonoids (flavonols, flavan-3-ols, and anthocyanins) reduced by a variable extent. The color intensity and red % decreased together with a decrease in anthocyanin content. This was accompanied by an increase in hue as well as yellow %. The final phenolic content was found to be between 119.54 and 180.93 mg/L, with anthocyanins as the predominant phenolic group (92.06%-93.03%), of which 3,5-O-diglucosidic anthocyanins made up 53.55%-79.04%. Phenolic acids were the primary non-anthocyanin phenolics at about 6.64%-7.5%. The phenolic contents and color parameters of Beibinghong dry red wine and several V. vinifera dry red wines of superior color quality were also used in an attempt to clarify the relationship between phenolics and color in the Beibinghong red ice wine. By using Pearson correlation analysis and principal component analysis (PCA), it was found that 3,5-O-diglucosidic anthocyanins and protocatechuic acid were the only characteristic phenolics that differentiated Beibinghong wines from the other selected red wines from more traditional varieties. They were also the main phenolics to be positively correlated with the hue and yellow % of the wine at the early stages leading into maturation. Their presence might, therefore, explain the relatively high hue and yellow % of Beibinghong ice wine.
Topics: Chimera; Flavonoids; Phenols; Principal Component Analysis; Vitis; Wine
PubMed: 27104511
DOI: 10.3390/molecules21040431 -
Current Protocols Essential Laboratory... Dec 2020Stored biological materials should have minimal pre-analytical variations in order to provide researchers with high-quality samples that will give reliable and...
Stored biological materials should have minimal pre-analytical variations in order to provide researchers with high-quality samples that will give reliable and reproducible results, yet methods of storage should be easy to implement, with minimal cost and health hazard. Frozen tissue samples are a valuable biological resource. Here we compare different methods, such as liquid nitrogen (LN) or dry ice (DI), to a cheap and safe alternative using an aluminum platform (AP). Murine fresh liver and pancreas tissues were used with varying lengths of warm ischemia time. Quality assessment was based on histological evaluation, DNA and RNA extraction and quantification, and RNA degradation analysis, as well preservation of antigens for immunofluorescence, in a blinded manner. Both in superficial and deep tissue sections, based on histological assessment, AP is superior to DI, or as good as LN techniques in terms of presence of ice crystals, cutting artifacts, and overall quality/structural preservation. DNA and RNA were successfully extracted in reasonable quantities from all freezing techniques, but RNA degradation was seen for pancreas samples across all techniques. Immunofluorescence with cytokeratin8 (CK-8), alpha smooth muscle actin (αSMA), CD3, and B220 shows equally good outcomes for AP and LN, which are better than DI. The aluminum platform is a cheap, yet reliable method to freeze samples, rapidly preserving histological, antigenic, and DNA/RNA quality. Wider testing is required across different sample types. © 2020 The Authors. : Flash-freezing fresh tissue with aluminum platform : Freezing fresh tissue with liquid nitrogen : Freezing fresh tissue with dry ice.
PubMed: 33381282
DOI: 10.1002/cpet.46 -
Antioxidants (Basel, Switzerland) Apr 2023Thermal reactions can significantly alter the metabolomic and lipidomic content of biofluids and tissues during storage. In this study, we investigated the stability of...
Thermal reactions can significantly alter the metabolomic and lipidomic content of biofluids and tissues during storage. In this study, we investigated the stability of polar metabolites and complex lipids in dry human serum and mouse liver extracts over a three-day period under various temperature conditions. Specifically, we tested temperatures of -80 °C (freezer), -24 °C (freezer), -0.5 °C (polystyrene box with gel-based ice packs), +5 °C (refrigerator), +23 °C (laboratory, room temperature), and +30 °C (thermostat) to simulate the time between sample extraction and analysis, shipping dry extracts to different labs as an alternative to dry ice, and document the impact of higher temperatures on sample integrity. The extracts were analyzed using five fast liquid chromatography-mass spectrometry (LC-MS) methods to screen polar metabolites and complex lipids, and over 600 metabolites were annotated in serum and liver extracts. We found that storing dry extracts at -24 °C and partially at -0.5 °C provided comparable results to -80 °C (reference condition). However, increasing the storage temperatures led to significant changes in oxidized triacylglycerols, phospholipids, and fatty acids within three days. Polar metabolites were mainly affected at storage temperatures of +23 °C and +30 °C.
PubMed: 37237852
DOI: 10.3390/antiox12050986 -
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 -
Stem Cell Research & Therapy Mar 2021Neural stem cell (NSC) therapy remains one of the most potential approaches for the treatment of neurological disorders. The discovery of human induced pluripotent stem...
BACKGROUND
Neural stem cell (NSC) therapy remains one of the most potential approaches for the treatment of neurological disorders. The discovery of human induced pluripotent stem cells (hiPSCs) and the establishment of hiPSC-derived human neural stem cells (hiNSCs) have revolutionized the technique of cell therapy. Meanwhile, it is often required that NSCs are stored and transported to a long distance for research or treatment purposes. Although high survival rates could be maintained, conventional methods for cell transportation (dry ice or liquid nitrogen) are inconvenient and expensive. Therefore, the establishment of a safe, affordable, and low-cost strategy to store and transport easily accessible hiPSCs and hiNSCs, with characteristics that match fetal hNSCs, is incredibly urgent.
METHODS
We reprogrammed human urinary cells to iPSCs using a non-integrating, virus-free technique and differentiated the iPSCs toward iNSCs/neurospheres and neurons, under Good Manufacturing Practice (GMP)-compatible conditions. The pluripotency of iPSCs and iNSCs was characterized by a series of classical methods (surface markers, karyotype analysis, and in vitro as well as in vivo differentiation capabilities, etc.).
RESULTS
Here, our results showed that we successfully generated hiNSCs/neurospheres from more available, non-invasive, and more acceptable urinary cells by a virus-free technique. Next, we demonstrated that the iNSCs differentiated into mature cerebral cortical neurons and neural networks. Interestingly, hiNSCs survived longer as neurospheres at ambient temperature (AT) than those cultured in a monolayer. Within 7 days approximately, the neural viability remained at > 80%, while hiNSCs cultured in a monolayer died almost immediately. Neurospheres exposed to AT that were placed under standard culture conditions (37 °C, 5% CO) recovered their typical morphology, and retained their proliferation and differentiation abilities.
CONCLUSIONS
In this study, we provided a simple method for the storage of NSCs as neurospheres at AT as an alternative method to more costly and inconvenient traditional methods of cryopreservation. This will enable hiNSCs to be transported over long distances at AT and facilitate the therapeutic application of NSCs as neurospheres without any further treatment.
Topics: Cell Differentiation; Cell- and Tissue-Based Therapy; Cells, Cultured; Humans; Induced Pluripotent Stem Cells; Neural Stem Cells; Neurons
PubMed: 33736654
DOI: 10.1186/s13287-021-02238-4 -
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