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Luminometric studies of Yeast Response to complex Environmental calcium Variations Demonstrate sensing of External calcium Ion changes

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Advances in Microbiology 2022年第9期12卷 555-567页

作者： Augustus c. parker David A. Mintz Francisco J. solis Pamela A. Marshall school of Mathematical and Natural sciences Arizona State University Glendale USA

The response of yeast to sharp environmental increases in calcium concentration has been extensively studied. However, systematic studies of the response under more general changes are still lacking. Only limited exploration of cellular responses has been conducted where calcium concentration is decreased. This article describes a set of luminometric experiments that monitor the cytosolic calcium concentration under changing external concentration conditions. As a decrease in external calcium concentrations requires the use of large sample volumes, the experiments require the use of equipment adapted for this purpose. We describe the modification of commercial luminometric equipment to make the exploration possible. We explore the yeast cellular behavior when an increase in external calcium concentration is followed by a decrease in external calcium concentration. We compare these results with those from the case of a double pulse of concentration increase. Results from the experiment show that the first, concentration increasing pulse produces the well-known sharp increase in cytosolic calcium followed by calcium sequestration to return to a cytosolic concentration near its initial condition. surprisingly, the calcium decrease step shows similar results with a cytosolic increase followed by a return to lower levels. The results suggest the presence of a calcium sensing mechanism regulating calcium influx from external sources. This mechanism would produce channel opening as a response to any changes in external concentration, be it an enhancement or a depletion.

关键词： saccharomyces cerevisiae calcium Homeostasis Extracellular Ion changes

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Photoprotective Ability of colored Iron Oxides in Tinted sunscreens against Ultraviolet, Visible Light and Near-Infrared Radiation

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Optics and Photonics Journal 2023年第8期13卷 199-208页

作者： Yohei Tanaka Richard parker Amaryllis Aganahi clinica Tanaka Plastic Reconstructive Surgery and Anti-Aging Center Matsumoto Japan RATIONALE Kyneton Victoria Australia

solar-induced skin damage continues to pose a problem to human health worldwide, despite the widespread recommendation and use of sunscreens. We have previously reported that solar visible light and near-infrared also contribute to skin damage and photoageing. Most commonly recommended sunscreens are only effective throughout the UV spectrum, offering no protection from visible light and near-infrared. To evaluate the enhanced solar-spectrum blocking ability of iron oxides, a double-beam spectrophotometer was used to optically measure the transmission spectra. The spectrophotometer deploys a unique, single monochromatic design to detect wavelength penetration in the range of 240 to 2600 nm. The sample without iron oxide (control) blocked over 80% of ultraviolet-c and ultraviolet-B but did not block ultraviolet-A, visible light, or near-infrared wavelengths. The samples with yellow, and red iron oxide blocked over 90% ultraviolet, but did not block visible light and near-infrared effectively. The sample with black iron oxide blocked visible light, and near-infrared effectively compared with other samples with yellow, blue, and red iron oxide. The sample with red and black iron oxides, and the sample with yellow, blue, red, and black iron oxides blocked ultraviolet through to near-infrared. It can be concluded that dark colored iron oxide combinations are effective at blocking from ultraviolet through to visible light and near-infrared radiation. The results of this study may also suggest that biological colour of human skin and subcutaneous tissues are conserved for comprehensive photoprotection.

关键词： Anti-Photoageing Photoimmunosuppression Photoprotection sunscreen Ultraviolet Visible Light Near-Infrared

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哺乳羔羊数及补充蛋白质对泌乳母羊生产性能的影响

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贵州农业科学 1986年第3期 64-66+41页

作者： s.c.Loerch K.EMcclure c.E.parker 王霞

前言提高繁殖率是提高母羊生产力的方法之一。因此商业性绵羊种群引种时,通常引进产仔数超过两只的种羊。在妊娠后期、分娩与哺乳的母羊及羔羊管理技术的发展是极为重要的。Gonyon和stookey(1983)介绍的开放式产羔栏可以为降低在产羔... 详细信息

前言提高繁殖率是提高母羊生产力的方法之一。因此商业性绵羊种群引种时,通常引进产仔数超过两只的种羊。在妊娠后期、分娩与哺乳的母羊及羔羊管理技术的发展是极为重要的。Gonyon和stookey(1983)介绍的开放式产羔栏可以为降低在产羔期间所需人力及提高羔羊成活率提供一个方法,由于人工喂养羔羊所需饲料和劳动价值高,所以迫切需要利用母羊自身的能力哺乳所产羔羊的管理方法。尽管有报导证明(Alexander,Davies 1959;Gardner,Hogue 1964)哺乳双羔与单羔的母羊相比,产奶量有所增加,但还没有进一步提高哺乳两只以上羔羊的母羊产奶量的报道。提高小肠氨基酸含量对刺激哺乳两只以上羔羊

关键词：哺乳羔羊产奶量血粉产乳量蛋白质饲料母羊生产性能

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用电极连接的有限元模型预测热特性

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炭素技术 1993年第1期12卷 21-22页

作者： s.F.Lewaaen M.c.parker 孙东初

电弧炉用的电极是由带有螺齿的两头为园锥形的接头连接成电极柱。由于接头的直径比所连接的电极尺寸小,因此,接头必须具有较高的强度以及横向较高、纵较低的热膨胀系数。连接体在热膨胀系数上的差异引起严重的热应力使接头孔变形,甚至... 详细信息

电弧炉用的电极是由带有螺齿的两头为园锥形的接头连接成电极柱。由于接头的直径比所连接的电极尺寸小,因此,接头必须具有较高的强度以及横向较高、纵较低的热膨胀系数。连接体在热膨胀系数上的差异引起严重的热应力使接头孔变形,甚至使连接失效。失效可以图1(a)所示的各种形式出现。所有这些失效形式可能是由热应力引起的,虽然机械力也能引起失效,但通常,机械力所引起的失效在较低温度比高温更易于出现。几年前,已提出了图1(b)所示模型的有限元分析程序。这个模型具有当今电弧炉工业中最普遍的连接装配工序的特征,接头装入电极的上端接头孔直到全螺纹啮合。电极联结是从电极接头孔的下端不断增进,然后拧紧。

关键词：电极有限元模型热特性电弧炉

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Addition of Pore-Forming Agents and Their Effect on the Pore Architecture and catalytic Behavior of shaped Zeolite-Based catalyst Bodies

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chemical & Biomedical Imaging 2023年第1期1卷 40-48页

作者： Nikolaos Nikolopoulos Luke A.parker Abhijit Wickramasinghe Oscar van Veenhuizen Gareth Whiting Bert M.Weckhuysen Inorganic chemistry and catalysis group Debye Institute for Nanomaterials Science&Institute for Sustainable and Circular ChemistryUtrecht University3584 CG UtrechtThe Netherlands TNO Environmental Modelling Sensing and AnalysisPrincetonlaa 63584 CB UtrechtThe Netherlands

Porous materials,such as solid catalysts,are used in various chemical reactions in industry to produce chemicals,materials,and *** the interplay between pore architecture and catalytic behavior is of great importance for synthesizing a better industrial-grade catalyst *** this study,we have investigated the modiffcation of the pore architecture of zeolite-based aluminabound shaped catalyst bodies via the addition of different starches as pore-forming agents.A combination of microscopy techniques allowed us to visualize the morphological changes induced and make a link between pore architecture,molecular transport,and catalytic *** for the catalytic performance in the methanol-to-hydrocarbons(MTH)reaction,pore-forming agents resulted in up to∼12%higher conversion,an increase of 74%and 77%in yield(14%and 13%compared to 8.6%and 7.7%of the reference sample in absolute yields)toward ethylene and propylene,respectively,and an improved lifetime of the catalyst materials.

关键词： shaped catalyst bodies Porogens Methanol-to-hydrocarbons Pore architecture coke formation Molecular transport Visualization

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80年代的食品微生物学

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食品科学 1982年第2期3卷 35-41+7页

作者： A.c.Baird-parker,丁积善英

当前,食品工业的要求及工艺正在不断改变,人们要求更好地保存食物和食物资源,加工日趋集中,分配链越来越长,方便食品的用量更有扩大,户外食品的消费也越益增加。贝尔德一帕克就根据这样的形势对80年代食品微生物学的要求及任务简单谈一... 详细信息

当前,食品工业的要求及工艺正在不断改变,人们要求更好地保存食物和食物资源,加工日趋集中,分配链越来越长,方便食品的用量更有扩大,户外食品的消费也越益增加。贝尔德一帕克就根据这样的形势对80年代食品微生物学的要求及任务简单谈一些自己的看法。

关键词：食品微生物学食品安全微生物生长

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Novel Low Viscosity Zinc Oxide, Iron Oxides and Erioglaucine sunscreen Potential to Protect from Ultraviolet, Visible Light and Near-Infrared Radiation

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Optics and Photonics Journal 2023年第9期13卷 217-226页

作者： Yohei Tanaka Richard parker Amaryllis Aganahi Ailen Pedroso clinica Tanaka Plastic Reconstructive Surgery and Anti-Aging Center Matsumoto Japan RATIONALE Kyneton Australia

Despite the widespread recommendation and use of sunscreens and ultraviolet blocking materials, solar-induced skin damage and photoageing continues to pose a problem to human health worldwide. We have previously reported that solar visible light and near-infrared also contribute to skin damage and photo ageing. Most commonly recommended sunscreens are only effective throughout the UV spectrum, offering no protection from visible light and near-infrared. A possible solution could be to augment sunscreens with metal oxides which block visible light and near-infrared radiation. To evaluate the enhanced solar-spectrum blocking ability of novel low viscosity sunscreen containing zinc and iron oxides, a double-beam spectrophotometer was used to optically measure the transmission spectra. The spectrophotometer deploys a unique, single monochromatic design to detect wavelength penetration in the range of 240 to 2600 nm. The sunscreen base without zinc oxide and iron oxides (control) blocked over 80% of ultraviolet-c and ultraviolet-B but did not block ultraviolet-A, visible light, or near-infrared. The novel low viscosity zinc oxide sample blocked almost over 90% ultraviolet, but did not block visible light and near-infrared sufficiently. However, the samples with the novel low viscosity zinc oxide, iron oxides and erioglaucine blocked almost over 90% of ultraviolet, visible light and near-infrared. It can be concluded that this novel combination of low viscosity zinc oxide, iron oxides and erioglaucine is effective at blocking ultraviolet, visible light and near-infrared radiation. The results of this study imply that sunscreens that provide comprehensive photoprotection from ultraviolet through to near-infrared should be adopted to prevent skin photodamage.