freezing

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  • 文章类型: Journal Article
    皮肤的选择对于体外渗透测试(IVPT)至关重要。目的探讨不同冻融过程对皮肤屏障功能和格拉司琼、利多卡因透皮通透性的影响。大鼠和无毛小鼠皮肤在-20℃冷冻9天后在三种不同条件下解冻:4℃解冻,室温(RT),和32℃。新鲜样品和解冻样品之间的药物稳态通量没有显着差异,但与新鲜皮肤相比,格拉司琼在室温和32℃解冻的大鼠皮肤中的渗透滞后时间存在显着差异。组织学研究和扫描电镜图像显示冻融皮肤无明显结构损伤,而紧密连接(TJ)蛋白Cldn-1的免疫组织化学染色和酶联免疫吸附试验显示表皮屏障明显受损。结论是,冻融过程增加了亲水性药物的扩散速率,部分原因是TJ的功能降解。它建议无毛,应使用近交系和相同的动物供体,选择的皮肤解冻方法应在IVPT之前进行验证,特别是亲水性药物。
    The selection of skin is crucial for the in vitro permeation test (IVPT). The purpose of this study was to investigate the influence of different freezing-thawing processes on the barrier function of skin and the transdermal permeability of granisetron and lidocaine. Rat and hairless mouse skins were thawed at three different conditions after being frozen at -20℃ for 9 days: thawed at 4℃, room temperature (RT), and 32℃. There were no significant differences in the steady-state fluxes of drugs between fresh and thawed samples, but compared with fresh skin there were significant differences in lag time for the permeation of granisetron in rat skins thawed at RT and 32℃. Histological research and scanning electron microscopy images showed no obvious structural damage on frozen/thawed skin, while immunohistochemical staining and enzyme-linked immunosorbent assay for the tight junction (TJ) protein Cldn-1 showed significantly impaired epidermal barrier. It was concluded that the freezing-thawing process increases the diffusion rate of hydrophilic drugs partly due to the functional degradation of TJs. It\'s recommended that hairless, inbred strains and identical animal donors should be used, and the selected thawing method of skin should be validated prior to IVPT, especially for hydrophilic drugs.
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  • 文章类型: Journal Article
    目的:评估安乐死洞穴蟑螂(CCs;Blaberusgiganteus)和马达加斯加嘶嘶声蟑螂(MHCs;Grompphadorhinaportentosa)的方法。据推测,两种建议的方法对于两种物种的人道大规模安乐死都是有效的。
    方法:约800CC。
    方法:将CC分成25、50、75、100和150克的重复组,并放入3.8L塑料袋中。27个MHC被分为2至3组。该研究于2023年1月至3月进行。所有CC组都以4L/min的速率暴露于100%二氧化碳(CO2),直到袋子充满。在1-L容器中的棉球上使用CO2或2mL异氟烷或CO2和异氟烷的组合类似地麻醉马达加斯加的嘶嘶声蟑螂。一旦蟑螂不动,进行了二次安乐死步骤。每个重量类别的一袋CC暴露于肥皂水(5%Dawn洗碗液),然后将第二个放入-80°C的冰箱中。将MHCs的容器均匀地暴露于2种安乐死方法。个体保持其二次安乐死方法30分钟。
    结果:无论每个袋子中的CC重量如何,对不动时间(1.8±0.4分钟[平均值±SD])没有影响。对于肥皂水,两种物种的失败率均为0.2%CI(-0.1%至1.5%[1/413]),而对于冷冻方法,则为0.5%CI(0.005%至1.9%[2/414])。这些结果支持在CC和MHC中使用两步安乐死方法。
    结论:这些方法将作为在蟑螂中人道大规模安乐死的基于证据的替代方法。
    OBJECTIVE: To evaluate methods for euthanizing cave cockroaches (CCs; Blaberus giganteus) and Madagascar hissing cockroaches (MHCs; Gromphadorhina portentosa). It was hypothesized that both suggested methods would be effective for humane mass euthanasia of both species.
    METHODS: Approximately 800 CC.
    METHODS: The CCs were separated into replicate groups of 25, 50, 75, 100, and 150 grams and placed into 3.8-L plastic bags. Twenty-seven MHCs were divided into groups of 2 to 3. The study took place from January to March 2023. All CC groups were exposed to 100% carbon dioxide (CO2) at a rate of 4 L/min until the bag was full. Madagascar hissing cockroaches were similarly anesthetized using either CO2 or 2 mL of isoflurane on a cotton ball in a 1-L container or a combination of CO2 and isoflurane. Once cockroaches were immobile, secondary euthanasia steps were performed. One bag of CCs per weight category was exposed to soapy water (5% Dawn dishwashing liquid), and the second was placed into a -80 °C freezer. The containers of MHCs were evenly exposed to the 2 euthanasia methods. Individuals remained in their secondary euthanasia method for 30 minutes.
    RESULTS: Regardless of the weight of the CCs within each bag, there was no impact on time (1.8 ± 0.4 minutes [mean ± SD]) to immobility. The failure rates for both species were 0.2% CI (-0.1% to 1.5% [1/413]) for soapy water and 0.5% CI (0.005% to 1.9% [2/414]) for the freezer method. These results support the use of both 2-step euthanasia methods in CCs and MHCs.
    CONCLUSIONS: These methods will serve as an evidence-based alternative for humane mass euthanasia in cockroaches.
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  • 文章类型: Journal Article
    冷适应细菌在极端寒冷和不同温度下生存的能力是由于其独特的属性,如细胞膜稳定性,肽聚糖生物合成的上调,细胞外聚合物的产生增加,和膜颜料的膨胀。各种冷适应蛋白质,包括冰核蛋白(INPs),抗冻蛋白(AFP),冷休克蛋白(Csps),和冷适应蛋白(CAPs),帮助细菌在这些环境中生存。为了使细胞在极端寒冷的条件下保持温度波动的稳定性,分子水平的生存策略及其机制在冰冻圈条件下的适应中起着重要作用。此外,多功能冷休克蛋白中存在的冷休克结构域在其适应策略中起着至关重要的作用。脂肽的重大贡献,渗透压,膜色素在极端环境中的生存中起着不可或缺的作用。这篇综述总结了冷适应细菌的进化史及其在恶劣的寒冷环境中茁壮成长的分子和细胞适应策略。它还讨论了产生的类胡萝卜素的重要性,脂质成分,冷冻保护剂,蛋白质,和与这种适应有关的监护人。此外,简要讨论了细胞内适应的功能和机制。通过了解其分子和细胞适应寒冷气候条件的内在机制,人们可以利用和探索其在各种生物技术应用及其进化旅程中的潜力。这篇综述将帮助生命科学界的所有分支了解嗜冷菌的基本微生物学及其在生命科学研究中的潜在前景。
    The ability of cold-adapted bacteria to survive in extreme cold and diverse temperatures is due to their unique attributes like cell membrane stability, up-regulation of peptidoglycan biosynthesis, increased production of extracellular polymeric substances, and expansion of membrane pigment. Various cold-adapted proteins, including ice-nucleating proteins (INPs), antifreeze proteins (AFPs), cold shock proteins (Csps), and cold-acclimated proteins (CAPs), help the bacteria to survive in these environments. To sustain cells from extreme cold conditions and maintain stability in temperature fluctuations, survival strategies at the molecular level and their mechanism play significant roles in adaptations in cryospheric conditions. Furthermore, cold shock domains present in the multifunctional cold shock proteins play crucial roles in their adaptation strategies. The considerable contribution of lipopeptides, osmolytes, and membrane pigments plays an integral part in their survival in extreme environments. This review summarizes the evolutionary history of cold-adapted bacteria and their molecular and cellular adaptation strategies to thrive in harsh cold environments. It also discusses the importance of carotenoids produced, lipid composition, cryoprotectants, proteins, and chaperones related to this adaptation. Furthermore, the functions and mechanisms of adaptations within the cell are discussed briefly. One can utilize and explore their potential in various biotechnology applications and their evolutionary journey by knowing the inherent mechanism of their molecular and cellular adaptation to cold climatic conditions. This review will help all branches of the life science community understand the basic microbiology of psychrophiles and their hidden prospect in life science research.
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  • 文章类型: Journal Article
    芽休眠的基本问题仍然存在,包括什么温度满足休眠要求(即,寒意积累)。最近的研究表明,冻结温度会促进寒冷的积累,而抗寒性会影响萌芽时间-用于休眠评估的表型。在这里,我们评估了在三种处理下,葡萄树(Vitishybrids)在整个寒冷积累过程中的芽抗寒性(CH)和萌芽反应:恒定(5°C),波动(每天-3.5至6.5°C),和现场条件(麦迪逊,WI,美国)。经历较低温度的冷却处理促进了抗寒性的更大增益(CHfield>CHflowating>CHconstant)。所有处理都减少了观察到的萌芽时间,并增加了寒意积累。然而,当调整萌芽时间以消除冷适应效应时,感知的治疗效果会发生变化。在三种经典的寒战模型中(北卡罗来纳州,犹他州,和动态),没有人能够正确描述对寒意积累的萌芽反应的调整时间。因此,提出了一种新的模型,该模型扩大了积冷温度的范围,使其包括冻结温度,并在波动的温度条件下增强了积冷。最重要的是,我们的分析表明,对不均匀适应的调整改变了寒战治疗的感知有效性.因此,芽休眠的未来工作将受益于同时评估抗寒性。
    Fundamental questions in bud dormancy remain, including what temperatures fulfill dormancy requirements (i.e., chill accumulation). Recent studies demonstrate freezing temperatures promote chill accumulation and cold hardiness influences time to budbreak - the phenotype used for dormancy evaluations. Here we evaluated bud cold hardiness (CH) and budbreak responses of grapevines (Vitis hybrids) throughout chill accumulation under three treatments: constant (5 °C), fluctuating (-3.5 to 6.5 °C daily), and field conditions (Madison, WI, USA). Chill treatments experiencing lower temperatures promoted greater gains in cold hardiness (CHfield>CHfluctuating>CHconstant). All treatments decreased observed time to budbreak with increased chill accumulation. However, perceived treatment effectiveness changed when time to budbreak was adjusted to remove cold acclimation effects. Among three classic chill models (North Carolina, Utah, and Dynamic), none were able to correctly describe adjusted time to budbreak responses to chill accumulation. Thus, a new model is proposed that expands the range of chill accumulation temperatures to include freezing temperatures and enhances chill accumulation under fluctuating temperature conditions. Most importantly, our analysis demonstrates adjustments for uneven acclimation change the perceived effectiveness of chill treatments. Therefore, future work in bud dormancy would benefit from simultaneously evaluating cold hardiness.
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  • 文章类型: Journal Article
    湖羊是一种以其高繁殖率而闻名的品种。一年四季都在发情期,其繁殖种群正在逐步扩大。然而,目前冷冻保存精液的技术效果有限,这阻碍了该物种的持续发展。目的探讨不同穿透性冷冻保护剂(CPAs)和蛋黄(EY)浓度对湖羊精液冷冻保存效果的影响,以确定最有效的组合。
    在这项研究中,甘油(GLY)的影响,乙二醇(EG),二甲基乙酰胺(DMA),二甲基亚砜(DMSO),不同比例的GLY和EG,通过检测精子总运动性(TM),研究EY对解冻后精子质量的影响,渐进运动(PM),直线速度(VSL),曲线速度(VCL),平均路径速度(VAP),头部侧向位移(ALH)的振幅,摆动运动系数(WOB),平均运动度(MAD),功能完整性(质膜完整性,顶体完整性)和活性氧(ROS)水平。
    当GLY和EG加在一起时,与其他浓度组相比,6%GLY显著(p<0.05)增加TM,PM,质膜完整性,和解冻精子的顶体完整性。此外,显著降低精子ROS水平(p<0.05)。在这项研究中,TM,6%EG的PM和膜完整性显著高于对照(p<0.05),1%GLY+5%EG和6%GLY+6%EG组。与其他浓度组相比,20%EY显著(p<0.05)提高了TM,PM,和解冻精子的质膜完整性。然而,顶体的完整性随着EY浓度的增加而增加。
    总而言之,与其他组相比,用含有6%GLY和20%EY的稀释剂稀释的解冻后的Huram精液表现出更高的质量。
    UNASSIGNED: The Hu sheep is a renowned breed known for its high reproductive rate. It is in estrus all year round, and its breeding population is gradually expanding. However, the current techniques for cryopreserving semen have limited effectiveness, which hinders the continuous development of this species. The purpose of this study is to explore the effects of different penetrating cryoprotectants (CPAs) and egg yolk (EY) concentrations on the cryopreservation of Hu ram semen to determine the most effective combination.
    UNASSIGNED: In this study, the effects of glycerol (GLY), ethylene glycol (EG), dimethylacetamide (DMA), dimethyl sulfoxide (DMSO), different proportions of GLY and EG, EY on sperm quality after thawing were investigated by detecting sperm total motility (TM), progressive motility (PM), straight-line velocity (VSL), curvilinear velocity (VCL), average path velocity (VAP), amplitude of lateral head displacement (ALH), wobble movement coefficient (WOB), average motion degree (MAD), functional integrity (plasma membrane integrity, acrosome integrity) and reactive oxygen species (ROS) level.
    UNASSIGNED: When GLY and EG were added together, compared to other concentration groups, 6% GLY significantly (p < 0.05) increased TM, PM, plasma membrane integrity, and acrosome integrity of thawed sperm. Additionally, it significantly (p < 0.05) decreased the ROS level of sperm. In this study, the TM, PM and membrane integrity of the 6% EG were significantly (p < 0.05) higher than those of the control, 1% GLY+5% EG and 6% GLY+6% EG groups. Compared to other concentration groups, 20% EY significantly (p < 0.05) improved the TM, PM, and plasma membrane integrity of thawed sperm. However, the integrity of the acrosome increased with the higher concentration of EY.
    UNASSIGNED: In conclusion, the post-thawed Hu ram semen diluted with a diluent containing 6% GLY and 20% EY exhibited higher quality compared to the other groups.
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  • 文章类型: Journal Article
    嵌入随机取向的大分子的玻璃化薄膜的形成是低温样品电子显微镜的必要先决条件。最常见的是,这是使用近40年前首次描述的骤降冷冻方法实现的。虽然这是一个强大的方法,不同大分子的行为在冻结时显示出很大的变化,并且通常需要进行优化以获得各向同性,高分辨率重建。对于这种薄膜中的大分子,在印迹和冷冻之间的时间内遇到空气-水界面并采用首选方向的可能性非常高。使用优先定向粒子的3D重建通常会导致各向异性和不可解释的映射。目前,这个普遍的问题没有通用的解决方案,但是已经尝试了几种主要集中在使用添加剂和新型网格修饰的样品制备上的方法。在这项研究中,通过对选定的研究良好的大分子进行分析,研究了物理和化学因素对大分子取向的影响,并揭示了确定蛋白质在低温EM网格上行为的重要参数。这些见解突出了导致优选取向的相互作用的性质,并且可用于系统地解决任何给定大分子的取向偏差,并提供设计小分子添加剂以增强样品稳定性和行为的框架。
    The formation of a vitrified thin film embedded with randomly oriented macromolecules is an essential prerequisite for cryogenic sample electron microscopy. Most commonly, this is achieved using the plunge-freeze method first described nearly 40 years ago. Although this is a robust method, the behaviour of different macromolecules shows great variation upon freezing and often needs to be optimized to obtain an isotropic, high-resolution reconstruction. For a macromolecule in such a film, the probability of encountering the air-water interface in the time between blotting and freezing and adopting preferred orientations is very high. 3D reconstruction using preferentially oriented particles often leads to anisotropic and uninterpretable maps. Currently, there are no general solutions to this prevalent issue, but several approaches largely focusing on sample preparation with the use of additives and novel grid modifications have been attempted. In this study, the effect of physical and chemical factors on the orientations of macromolecules was investigated through an analysis of selected well studied macromolecules, and important parameters that determine the behaviour of proteins on cryo-EM grids were revealed. These insights highlight the nature of the interactions that cause preferred orientations and can be utilized to systematically address orientation bias for any given macromolecule and to provide a framework to design small-molecule additives to enhance sample stability and behaviour.
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  • 文章类型: Journal Article
    本研究旨在探讨纳米硒(SeNP)和亚硒酸钠(SS)对犬精液冷冻过程中氧化应激的保护作用。在研究中使用总共六只狗。通过按摩方法在不同时间从狗身上收集射精三次。总共使用了18种射精,每种射精分为五个实验组。实验组被设计为不含抗氧化剂的Tris补充剂对照,1μg/mLSeNP1、2μg/mLSeNP2和1μg/mLSS1和2μg/mLSS2。延长的精液在4°C下平衡1小时,然后在液氮蒸气中冷冻并储存在液氮(〜-196°C)中。解冻后,精液样本根据CASA运动和运动学参数进行评估,精子质膜完整性和活力(HE测试),精子形态(SpermBlue)和DNA片段化(GoldCyto)。抗氧化酶活性(谷胱甘肽过氧化物酶;GPX,超氧化物歧化酶;SOD,过氧化氢酶;CAT)和脂质过氧化(丙二醛;MDA)在冻融的狗精子中进行了评估。当结果进行统计评估时,渐进的运动性,VCL,解冻后,SeNP1组的VAP运动学参数明显高于对照组(p<0.05)。在SeNP1组中观察到最高的质膜完整性和有活力的精子比例,但两组间无统计学差异(p>.05)。尽管在添加不同硒形式的所有组中观察到总形态异常的比率较低,与对照组相比,没有发现统计学差异。SeNP1组精子尾部异常显著低于对照组和SS2组(p<0.05)。在SeNP1组中观察到最低的片段化DNA比率,但两组间无统计学差异(p>.05)。尽管在精子抗氧化谱的评估中各组之间没有统计学差异,最高的GPX,SeNP1组获得SOD和CAT值和最低的脂质过氧化值。因此,确定在狗精液中添加1μg/mL剂量的基于tris的补充剂对精子参数有利,特别是精子运动学特性和精子形态,因此纳米硒,纳米技术产品,对狗精液的冷冻做出了重大贡献。
    This study aimed to investigate the protective effects of nanoparticle selenium (SeNP) and sodium selenite (SS) on preventing oxidative stress during the freezing process of dog semen. A total of six dogs were used in the study. The ejaculate was collected from dogs three times at different times by massage method. A total of 18 ejaculates were used and each ejaculate was divided in five experimental groups. The experimental groups were designed to tris extender containing no antioxidants control, 1 μg/mL SeNP1, 2 μg/mL SeNP2, and 1 μg/mL SS1 and 2 μg/mL SS2. Extended semen were equilibrated for 1 h at 4°C, then frozen in liquid nitrogen vapour and stored in liquid nitrogen (~-196°C). After thawing, semen samples were evaluated in terms of CASA motility and kinematic parameters, spermatozoa plasma membrane integrity and viability (HE Test), spermatozoa morphology (SpermBlue) and DNA fragmentation (GoldCyto). Antioxidant enzyme activity (glutathione peroxidase; GPX, superoxide dismutase; SOD, catalase; CAT) and lipid peroxidation (malondialdehyde; MDA) were evaluated in frozen-thawed dog sperm. When the results were evaluated statistically, the progressive motility, VCL, and VAP kinematic parameters in the SeNP1 group were significantly higher than the control group after thawing (p < .05). The highest ratio of plasma membrane integrity and viable spermatozoa was observed in the SeNP1 group, but there was no statistical difference found between the groups (p > .05). Although the ratio of total morphological abnormality was observed to be lower in all groups to which different selenium forms were added, compared to the control group, no statistical difference was found. Spermatozoa tail abnormality was significantly lower in the SeNP1 group than in the control and SS2 group (p < .05). The lowest ratio of fragmented DNA was observed in the SeNP1 group, but there was no statistical difference was found between the groups (p > .05). Although there was no statistical difference between the groups in the evaluation of sperm antioxidant profile, the highest GPX, SOD and CAT values and the lowest lipid peroxidation values were obtained in the SeNP1 group. As a result, it was determined that 1 μg/mL dose of SeNP added to the tris-based extender in dog semen was beneficial on spermatological parameters, especially sperm kinematic properties and sperm morphology, and therefore nanoparticle selenium, a nanotechnology product, made a significant contribution to the freezing of dog semen.
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  • 文章类型: Journal Article
    蓝藻蓝蛋白色素因其性质在各种行业中被广泛使用,包括食物,化妆品,和药物。尽管有潜力,挑战存在,如影响产量的提取方法,稳定性,和纯洁。这项研究调查了冻融(FT)循环次数对从四种蓝细菌物种的湿生物量中提取藻蓝蛋白的影响(Arthrospiraplatensis,菜枝绿叶,Phormidiumsp.,和集胞藻。),随着五种提取溶液(Tris-HCl缓冲液,磷酸盐缓冲液,CaCl2,去离子水,和自来水)在各种pH值。集胞藻。在所研究的物种中,藻蓝蛋白含量最高。对于A.platensis,Tris-HCl缓冲液从第一个FT循环产生最大的藻蓝蛋白浓度,而磷酸盐缓冲液从第二个循环中提供了令人满意的结果。同样,Tris-HCl缓冲液对C.fritschii(第一个循环的最大值的68.5%)显示出有希望的结果,在第七个循环中达到最高浓度(~12%w/w),使用磷酸盐缓冲液。Phormidiumsp.从使用自来水的第一个循环产生最大的色素浓度。在特定物种的最佳提取解决方案中,Tris-HCl缓冲液对所有物种具有足够的提取功效,从第一个周期。这项研究代表了从各种蓝细菌物种中建立藻蓝蛋白通用提取方法的第一步。
    Cyanobacterial phycocyanin pigment is widely utilized for its properties in various industries, including food, cosmetics, and pharmaceuticals. Despite its potential, challenges exist, such as extraction methods impacting yield, stability, and purity. This study investigates the impact of the number of freeze-thaw (FT) cycles on the extraction of phycocyanin from the wet biomass of four cyanobacteria species (Arthrospira platensis, Chlorogloeopsis fritschii, Phormidium sp., and Synechocystis sp.), along with the impact of five extraction solutions (Tris-HCl buffer, phosphate buffer, CaCl2, deionized water, and tap water) at various pH values. Synechocystis sp. exhibited the highest phycocyanin content among the studied species. For A. platensis, Tris-HCl buffer yielded maximum phycocyanin concentration from the first FT cycle, while phosphate buffer provided satisfactory results from the second cycle. Similarly, Tris-HCl buffer showed promising results for C. fritschii (68.5% of the maximum from the first cycle), with the highest concentration (~12% w/w) achieved during the seventh cycle, using phosphate buffer. Phormidium sp. yielded the maximum pigment concentration from the first cycle using tap water. Among species-specific optimal extraction solutions, Tris-HCl buffer demonstrated sufficient extraction efficacy for all species, from the first cycle. This study represents an initial step toward establishing a universal extraction method for phycocyanin from diverse cyanobacteria species.
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  • 文章类型: Journal Article
    我们回顾了最近关于具有波动体积的“可压缩细胞”的伊辛样模型的工作,因此,在NpT和μpT集合中自然处理。除了体积现象,局部熵效应是模型的关键基础。我们专注于“可压缩电池气体”(CCG),即,晶胞体积波动的晶格气体,和“可压缩细胞液体”(CCL),具有单个占据的细胞和波动的细胞体积。CCG考虑了通过非对称流体临界性的“完全缩放”公式预测的奇异直径和“阳-阳特征”,具有包含“冰状”氢键的特定版本,进一步描述了过冷水的低温异常热力学的“无奇点场景”。反过来,合适的CCL变体构成了水样液-液临界性和硬球系统的冻结过渡的适当原型。在将空置单元格合并到这种两状态CCL变体中时,一个获得三态,类似于BEG的模型提供了对水的“第二临界点情景”和氩气等简单物质的整个相行为的令人满意的描述。未来的挑战包括水的晶体-流体相行为和亚稳态。
    We review recent work on Ising-like models with \"compressible cells\" of fluctuating volume that, as such, are naturally treated in NpT and μpT ensembles. Besides volumetric phenomena, local entropic effects crucially underlie the models. We focus on \"compressible cell gases\" (CCG), namely, lattice gases with fluctuating cell volumes, and \"compressible cell liquids\" (CCL) with singly occupied cells and fluctuating cell volumes. CCGs contemplate singular diameters and \"Yang-Yang features\" predicted by the \"complete scaling\" formulation of asymmetric fluid criticality, with a specific version incorporating \"ice-like\" hydrogen bonding further describing the \"singularity-free scenario\" for the low-temperature unusual thermodynamics of supercooled water. In turn, suitable CCL variants constitute adequate prototypes of water-like liquid-liquid criticality and the freezing transition of a system of hard spheres. On incorporating vacant cells to such two-state CCL variants, one obtains three-state, BEG-like models providing a satisfactory description of water\'s \"second-critical-point scenario\" and the whole phase behavior of a simple substance like argon. Future challenges comprise water\'s crystal-fluid phase behavior and metastable states.
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  • 文章类型: Journal Article
    微生物群在所有后生动物的健康中起着关键作用。微生物组是否以及如何有利于生物体对极端条件的适应过程,比如南极洲,与大多数后生动物不相容,仍然未知。我们调查了三种特有和广泛分布的南极多毛类物种的微生物组:双毛,Aphlochaetapalmeri,和紫草虫。我们在这里报告说,这些无脊椎动物含有一个稳定的细菌核心,主要由Meiothermus和Anoxybacillus,配备了通用的基因组成和独特的蛋白质组合,可用于应对pangenomic和metaprotec分析所揭示的极端寒冷的条件。Meiothermus和Anoxybacillus与这些南极多毛菌之间的紧密系统共生关系表明,它们与宿主之间的联系始于过去,以支持对南极海洋的适应性。在南极多毛菌中发现的广泛的细菌冷冻保护蛋白可能对开发基于自然的生物技术应用有用。
    The microbiome plays a key role in the health of all metazoans. Whether and how the microbiome favors the adaptation processes of organisms to extreme conditions, such as those of Antarctica, which are incompatible with most metazoans, is still unknown. We investigated the microbiome of three endemic and widespread species of Antarctic polychaetes: Leitoscoloplos geminus, Aphelochaeta palmeri, and Aglaophamus trissophyllus. We report here that these invertebrates contain a stable bacterial core dominated by Meiothermus and Anoxybacillus, equipped with a versatile genetic makeup and a unique portfolio of proteins useful for coping with extremely cold conditions as revealed by pangenomic and metaproteomic analyses. The close phylosymbiosis between Meiothermus and Anoxybacillus and these Antarctic polychaetes indicates a connection with their hosts that started in the past to support holobiont adaptation to the Antarctic Ocean. The wide suite of bacterial cryoprotective proteins found in Antarctic polychaetes may be useful for the development of nature-based biotechnological applications.
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