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Scientific Reports Aug 2020In all arthropods the plesiomorphic (ancestral character state) kind of visual system commonly is considered to be the compound eye. Here we are able to show the...
In all arthropods the plesiomorphic (ancestral character state) kind of visual system commonly is considered to be the compound eye. Here we are able to show the excellently preserved internal structures of the compound eye of a 429 Mya old Silurian trilobite, Aulacopleura koninckii (Barrande, 1846). It shows the characteristic elements of a modern apposition eye, consisting of 8 (visible) receptor cells, a rhabdom, a thick lens, screening pigment (cells), and in contrast to a modern type, putatively just a very thin crystalline cone. Functionally the latter underlines the idea of a primarily calcitic character of the lens because of its high refractive properties. Perhaps the trilobite was translucent. We show that this Palaeozoic trilobite in principle was equipped with a fully modern type of visual system, a compound eye comparable to that of living bees, dragonflies and many diurnal crustaceans. It is an example of excellent preservation, and we hope that this manuscript will be a starting point for more research work on fossil evidence, and to develop a deeper understanding of the evolution of vision.
Topics: Animals; Arthropods; Biological Evolution; Compound Eye, Arthropod; Extinction, Biological; Fossils; Preservation, Biological
PubMed: 32792496
DOI: 10.1038/s41598-020-69219-0 -
Annual Review of Biomedical Engineering Jun 2019Successful stabilization and preservation of biological materials often utilize low temperatures and dehydration to arrest molecular motion. Cryoprotectants are... (Review)
Review
Successful stabilization and preservation of biological materials often utilize low temperatures and dehydration to arrest molecular motion. Cryoprotectants are routinely employed to help the biological entities survive the physicochemical and mechanical stresses induced by cold or dryness. Molecular interactions between biomolecules, cryoprotectants, and water fundamentally determine the outcomes of preservation. The optimization of assays using the empirical approach is often limited in structural and temporal resolution, whereas classical molecular dynamics simulations can provide a cost-effective glimpse into the atomic-level structure and interaction of individual molecules that dictate macroscopic behavior. Computational research on biomolecules, cryoprotectants, and water has provided invaluable insights into the development of new cryoprotectants and the optimization of preservation methods. We describe the rapidly evolving state of the art of molecular simulations of these complex systems, summarize the molecular-scale protective and stabilizing mechanisms, and discuss the challenges that motivate continued innovation in this field.
Topics: Biomedical Engineering; Computer Simulation; Cryopreservation; Cryoprotective Agents; Erwinia; Freeze Drying; Humans; Hydrogen Bonding; Models, Molecular; Molecular Dynamics Simulation; Pseudomonas; Pseudomonas syringae; Trehalose; Water
PubMed: 30525930
DOI: 10.1146/annurev-bioeng-060418-052130 -
Annals of the New York Academy of... Jun 2021The dating of organic findings is a fundamental task for many scientific fields. Radiocarbon dating is currently the most commonly used method. For wood,... (Review)
Review
The dating of organic findings is a fundamental task for many scientific fields. Radiocarbon dating is currently the most commonly used method. For wood, dendrochronology is another state-of-the-art method. Both methods suffer from systematic restrictions, leading to samples that have not yet been able to be dated. Molecular changes over time are reported for many materials under different preservation conditions. Many of them are intrinsically monotonous. These monotonous molecular decay (MD) patterns can be understood as clocks that start at the time when a given molecule was formed. Factors that influence these clocks include input material composition and preservation conditions. Different wood species, degrees of pyrolysis, and pretreatments lead to different prediction models. Preservation conditions might change the speed of a given clock and lead to different prediction models. Currently published models for predicting the age of wood, paper, and parchment depend on infrared spectroscopy. In contrast to radiocarbon dating, dating via MD does not comprise a single methodology. Some clocks may deliver less precise results than the others. Ultimately, developing a completely different, new dating strategy-such as MD dating-will help to bring to light a treasure trove of information hidden in the darkness of organic findings.
Topics: Amber; Animals; Archaeology; Bone and Bones; Charcoal; Hair; History, Ancient; Humans; Organic Chemicals; Paper; Plant Bark; Preservation, Biological; Radiometric Dating; Skin; Spectroscopy, Fourier Transform Infrared; Time Factors; Wood
PubMed: 33442875
DOI: 10.1111/nyas.14560 -
Biopreservation and Biobanking Apr 2017The current gold standard for sperm preservation is storage at cryogenic temperatures. Dry preservation is an attractive alternative, eliminating the need for ultralow... (Review)
Review
The current gold standard for sperm preservation is storage at cryogenic temperatures. Dry preservation is an attractive alternative, eliminating the need for ultralow temperatures, reducing storage maintenance costs, and providing logistical flexibility for shipping. Many seeds and anhydrobiotic organisms are able to survive extended periods in a dry state through the accumulation of intracellular sugars and other osmolytes and are capable of returning to normal physiology postrehydration. Using techniques inspired by nature's adaptations, attempts have been made to dehydrate and dry preserve spermatozoa from a variety of species. Most of the anhydrous preservation research performed to date has focused on mouse spermatozoa, with only a small number of studies in nonrodent mammalian species. There is a significant difference between sperm function in rodent and nonrodent mammalian species with respect to centrosomal inheritance. Studies focused on reproductive technologies have demonstrated that in nonrodent species, the centrosome must be preserved to maintain sperm function as the spermatozoon centrosome contributes the dominant nucleating seed, consisting of the proximal centriole surrounded by pericentriolar components, onto which the oocyte's centrosomal material is assembled. Preservation techniques used for mouse sperm may therefore not necessarily be applicable to nonrodent spermatozoa. The range of technologies used to dehydrate sperm and the effect of processing and storage conditions on fertilization and embryogenesis using dried sperm are reviewed in the context of reproductive physiology and cellular morphology in different species.
Topics: Animals; DNA Damage; Desiccation; Fertilization; Humans; Male; Semen Preservation; Species Specificity; Spermatozoa
PubMed: 28398834
DOI: 10.1089/bio.2016.0087 -
Frontiers in Endocrinology 2023Traditional therapeutic interventions aim to restore male fertile potential or preserve sperm viability in severe cases, such as semen cryopreservation, testicular... (Review)
Review
Traditional therapeutic interventions aim to restore male fertile potential or preserve sperm viability in severe cases, such as semen cryopreservation, testicular tissue, germ cell transplantation and testicular graft. However, these techniques demonstrate several methodological, clinical, and biological limitations, that impact in their results. In this scenario, reproductive medicine has sought biotechnological alternatives applied for infertility treatment, or to improve gamete preservation and thus increase reproductive rates and . One of the main approaches employed is the biomimetic testicular tissue reconstruction, which uses tissue-engineering principles and methodologies. This strategy pursues to mimic the testicular microenvironment, simulating physiological conditions. Such approach allows male gametes maintenance in culture or produce viable grafts that can be transplanted and restore reproductive functions. In this context, the application of several biomaterials have been proposed to be used in artificial biological systems. From synthetic polymers to decellularized matrixes, each biomaterial has advantages and disadvantages regarding its application in cell culture and tissue reconstruction. Therefore, the present review aims to list the progress that has been made and the continued challenges facing testicular regenerative medicine and the preservation of male reproductive capacity, based on the development of tissue bioengineering approaches for testicular tissue microenvironment reconstruction.
Topics: Male; Humans; Biocompatible Materials; Semen; Testis; Cryopreservation; Tissue Engineering
PubMed: 37008920
DOI: 10.3389/fendo.2023.1085872 -
Communications Biology Feb 2023Successful organ or tissue long-term preservation would revolutionize biomedicine. Cartilage cryopreservation enables prolonged shelf life of articular cartilage, posing...
Successful organ or tissue long-term preservation would revolutionize biomedicine. Cartilage cryopreservation enables prolonged shelf life of articular cartilage, posing the prospect to broaden the implementation of promising osteochondral allograft (OCA) transplantation for cartilage repair. However, cryopreserved large sized cartilage cannot be successfully warmed with the conventional convection warming approach due to its limited warming rate, blocking its clinical potential. Here, we develope a nanowarming and ice-free cryopreservation method for large sized, intact articular cartilage preservation. Our method achieves a heating rate of 76.8 °C min, over one order of magnitude higher than convection warming (4.8 °C min). Using systematic cell and tissue level tests, we demonstrate the superior performance of our method in preserving large cartilage. A depth-dependent preservation manner is also observed and recapitulated through magnetic resonance imaging and computational modeling. Finally, we show that the delivery of nanoparticles to the OCA bone side could be a feasible direction for further optimization of our method. This study pioneers the application of nanowarming and ice-free cryopreservation for large articular cartilage and provides valuable insights for future technique development, paving the way for clinical applications of cryopreserved cartilage.
Topics: Swine; Animals; Cartilage, Articular; Cryopreservation; Tissue Preservation; Magnetic Resonance Imaging
PubMed: 36828843
DOI: 10.1038/s42003-023-04577-9 -
Nature Communications Aug 2023Current machine perfusion technology permits livers to be preserved ex situ for short periods to assess viability prior to transplant. Long-term normothermic perfusion...
Current machine perfusion technology permits livers to be preserved ex situ for short periods to assess viability prior to transplant. Long-term normothermic perfusion of livers is an emerging field with tremendous potential for the assessment, recovery, and modification of organs. In this study, we aimed to develop a long-term model of ex situ perfusion including a surgical split and simultaneous perfusion of both partial organs. Human livers declined for transplantation were perfused using a red blood cell-based perfusate under normothermic conditions (36 °C) and then split and simultaneously perfused on separate machines. Ten human livers were split, resulting in 20 partial livers. The median ex situ viability was 125 h, and the median ex situ survival was 165 h. Long-term survival was demonstrated by lactate clearance, bile production, Factor-V production, and storage of adenosine triphosphate. Here, we report the long-term ex situ perfusion of human livers and demonstrate the ability to split and perfuse these organs using a standardised protocol.
Topics: Humans; Liver Transplantation; Liver; Perfusion; Bile; Preservation, Biological
PubMed: 37553343
DOI: 10.1038/s41467-023-40154-8 -
Biomolecules May 2019The cryopreservation of gametes and embryos is a technique widely used in reproductive biology. This technology helps in the reproductive management of domesticated... (Review)
Review
The cryopreservation of gametes and embryos is a technique widely used in reproductive biology. This technology helps in the reproductive management of domesticated animals, and it is an important tool for gene banking and for human-assisted reproductive technologies. Antifreeze proteins are naturally present in several organisms exposed to subzero temperatures. The ability for these proteins to inhibit ice recrystallization together with their ability to interact with biological membranes makes them interesting molecules to be used in cryopreservation protocols. This mini-review provides a general overview about the use of antifreeze proteins to improve the short and long term storage of gametes and embryos.
Topics: Animals; Antifreeze Proteins; Cryopreservation; Embryo, Mammalian; Fertility Preservation; Humans; Male; Oocytes; Semen Preservation
PubMed: 31075977
DOI: 10.3390/biom9050181 -
Methods in Molecular Biology (Clifton,... 2021Mass transfer of protectant chemicals is a fundamental aspect of cryopreservation and freeze-drying protocols. As such, mass transfer modeling is useful for design of...
Mass transfer of protectant chemicals is a fundamental aspect of cryopreservation and freeze-drying protocols. As such, mass transfer modeling is useful for design of preservation methods. Cell membrane transport modeling has been successfully used to guide design of preservation methods for isolated cells. For tissues, though, there are several mass transfer modeling challenges that arise from phenomena associated with cells being embedded in a tissue matrix. Both cells and the tissue matrix form a barrier to the free diffusion of water and protective chemicals. Notably, the extracellular space becomes important to model. The response of cells embedded in the tissue is dependent on the state of the extracellular space which varies both spatially and temporally. Transport in the extracellular space can also lead to changes in tissue size. In this chapter, we describe various mass transfer models that can be used to describe transport phenomena occurring during loading of tissues with protective molecules for cryopreservation applications. Assumptions and simplifications that limit the applicability of each of these models are discussed.
Topics: Animals; Biological Transport; Cell Membrane; Cell Membrane Permeability; Computer Simulation; Cryopreservation; Cryoprotective Agents; Freeze Drying; Humans; Models, Theoretical
PubMed: 32797411
DOI: 10.1007/978-1-0716-0783-1_5 -
PloS One 2018Early detection and diagnosis of endometrial carcinoma and precancerous change would undoubtedly become the most alluring part for researchers. With the emergence of... (Comparative Study)
Comparative Study
OBJECTIVE
Early detection and diagnosis of endometrial carcinoma and precancerous change would undoubtedly become the most alluring part for researchers. With the emergence of endometrial brush samplers, a new upsurge in endometrial cytology is in the making. But endometrial specimens obtained by the endometrial brush samplers require special preservation solution. The objective of this study is to develop a new kind of endometrial-cell preservation solution and to test the availability compared with a patented liquid-based cell preservation solution.
METHODS
In this controlled study, we had 5 endometrial cases collected with Li Brush from the First Affiliated Hospital of Xi'an Jiaotong University (09/2016 to 12/2016). The samples of each case were collected 2 times separately and perserved in different perservation solutions. One was a kind of novel endometrial cell preservation solution and the other was a kind of patented liquid-based cell (LBC) preservation solution. The endometrial cells were smeared on slides by using the ZP-C automated slide preparation system and stained with Papanicolaou stain. A semi-quantitative scoring system was used to analyze the quality of slides. Statistical analysis was performed using the Wilcoxon signed rank test on the SPSS program (SPSS 18.0). In all LBC preparations, endometrial cells from the novel endometrial cells preservation solution had more cell quantity, less red blood cell fragments, and the background was cleaner compared with control group. Although the novel endometrial-cell preservation solution showed cellularity and absence of blood and debris expressed by no statistically significant differences (p = 0.063 and 0.102 respectively). The preservation period of the two kinds of liquids was equivalent.
CONCLUSIONS
The novel endometrial-cell preservation solution is superior to the liquid-base cell preservation solution for cervical cells, with clear background, diagnostic cells and low cost.
Topics: Adult; Ammonium Chloride; Cytodiagnosis; Endometrial Neoplasms; Endometrium; Female; Fixatives; Hemolysis; Humans; Middle Aged; Precancerous Conditions; Preservation, Biological; Solutions; Staining and Labeling
PubMed: 29401497
DOI: 10.1371/journal.pone.0190851