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Spray freeze drying of small nucleic acids as inhaled powder for pulmonary delivery

Asian Journal of Pharmaceutical Sciences 2018年第2期13卷 163-172页

作者： Wanling Liang Alan Y.L.Chan Michael Y.T.Chow Fiona F.K.Lo Yingshan Qiu Philip C.L.Kwok Jenny K.W.Lam Department of Pharmacology and Pharmacy Li Ka Shing Faculty of Medicine The University of Hong Kong Advanced Drug Delivery Group Faculty of Pharmacy The University of Sydney

The therapeutic potential of small nucleic acids such as small interfering RNA(siRNA) to treat lung diseases has been successfully demonstrated in many in vivo studies. A major barrier to their clinical application is the lack of a safe and efficient inhaled formulation.In this study, spray freeze drying was employed to prepare dry powder of small nucleic acids.Mannitol and herring sperm DNA were used as bulking agent and model of small nucleic acid therapeutics, respectively. Formulations containing different solute concentration and DNA concentration were produced. The scanning electron microscope(SEM) images showed that the porosity of the particles increased as the solute concentration decreased. Powders prepared with solute concentration of 5% w/v were found to maintain a balance between porosity and robustness. Increasing concentration of DNA improved the aerosol performance of the formulation. The dry powder formulation containing 2% w/w DNA had a median diameter of 12.5 μm, and the aerosol performance study using next generation impactor(NGI) showed an emitted fraction(EF) and fine particle fraction(FPF) of 91% and 28% respectively. This formulation(5% w/v solute concentration and 2% w/w nucleic acid) was adopted subsequently to produce siRNA powder. The gel retardation and liquid chromatography assays showed that the siRNA remained intact after spray freeze drying even in the absence of delivery vector. The siRNA powder formulation exhibited a high EF of 92.4%and a modest FPF of around 20%. Further exploration of this technology to optimise inhaled siRNA powder formulation is warranted.

关键词： Inhalation Pulmonary delivery Small interfering RNA Spray freeze drying

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智能冠状动脉运动追踪平台Snapshot freeze在冠状动脉CT血管成像中的应用

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中国医学影像技术 2014年第12期30卷 1822-1826页

作者：高建华陈晓霞王贵生韩文娟赵国全武警总医院CT科北京100039

目的探讨智能冠状动脉运动追踪平台Snapshot freeze（SSF）在冠状动脉CT血管成像（CCTA）中的应用价值。方法连续选取61例患者,使用Discovery CT750 HD Freedom进行冠状动脉扫描,扫描后分别使用和不使用SSF重建,得到A、B两组图像;根据... 详细信息

目的探讨智能冠状动脉运动追踪平台Snapshot freeze（SSF）在冠状动脉CT血管成像（CCTA）中的应用价值。方法连续选取61例患者,使用Discovery CT750 HD Freedom进行冠状动脉扫描,扫描后分别使用和不使用SSF重建,得到A、B两组图像;根据扫描实时心率将患者分为低心率组（心率≤70次/分,n=34）,中高心率组（心率71～80次/分,n=14）和高心率组（心率〉80次/分,n=13）。对比分析A、B组间和不同心率组间的图像质量差异。结果除左主干（S5）外,B组冠状动脉各节段图像质量评分均优于A组（P均〈0.05）;S5段剔除评分为5分者后,其余7例B组图像质量均优于A组（P=0.008）;未使用SSF重建时不可诊断的42个节段经用SSF重建后全部可用于诊断。未使用SSF重建的不同心率组间除S7、S9段外,其余各节段图像质量评分差异均有统计学意义（P均〈0.05）,图像质量随心率增加而下降;使用SSF重建后,不同心率组间各节段图像质量评分差异均无统计学意义（P均〉0.05）。未使用SSF重建的右冠状动脉中段（S2）在15段中评分最低（2.88±0.91）分,S3次之（3.65±1.32）分,且S2在低心率组亦有17例出现移动伪影影响其评估;使用SSF重建后,S2、S3移动伪影显著改善,评分分别提升至（4.32±0.59）分和（4.49±0.59）分,均满足诊断需求。结论 SSF能够有效地纠正高心率及心率波动导致的冠状动脉血管移动伪影,优化CCTA图像质量,尤其对右冠状动脉移动伪影有显著意义。

关键词：冠状血管体层摄影术,X线计算机图像质量 Snapshot freeze

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freeze Concentration of Proteins in Antarctic Krill Wash Water

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Journal of Ocean University of China 2017年第6期16卷 1109-1114页

作者： QI Xiangming XU Jing ZHAO Kuo GUO Hui MA Lei College of Food Science and Engineering Ocean University of China Qingdao 266003 P. R. China

Water-washing removes fluoride from Antarctic krill but produces large volumes of wash water containing water-soluble proteins and fluoride. The freeze concentration method was tested to determine if it could be used to recover water-soluble proteins while leaving the fluoride in solution. After freezing and thawing the wash water, protein and fluoride contents of the thawed fractions were determined to explore the melting regularity of components in the wash water. The highest concentration factors of protein and fluoride were obtained after 80 min of thawing, such as 1.48 ± 0.06 and 1.35 ± 0.04 times, respectively. The free amino-nitrogen(FAN) content and sodium dodecyl sulfate-polyacrylamide gel electrophoresis pattern results revealed that the highest concentrations of all ingredients were obtained after 80 min of the process. The degree of hydrolysis of all fractions from the thawing process fluctuated in a narrow range around 12% during the entire process, indicating that the thawing order did not change with various proteins or time during the entire thawing course. These results demonstrate that the freeze concentration method can be used to concentrate protein solutions, even those with fluoride. It was concluded that condensation was achieved and no ingredient could be separated, regardless of fluoride, amino acids, or different proteins in the water.

关键词： Antarctic krill freeze concentration wash water protein extraction fluoride

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Effect of freeze-thaw cycles on uniaxial mechanical properties of cohesive coarse-grained soils

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Journal of Mountain Science 2019年第9期16卷 2159-2170页

作者： QU Yong-long CHEN Guo-liang NIU Fu-jun NI Wan-kui MU Yan-hu LUO Jing College of Geology Engineering and Geomatics Chang' an University Xi'an 710054 China China Gold Group Tibet Tyrone Mining Development Co. Ltd. Tibet 850000 China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou 730000 China South China Institute of Geotechnical Engineering School of Civil Engineering and Transportation South China University of Technology Guangzhou 510641 China

freeze-thaw cycles are closely related to the slope instability in high-altitude mountain regions. In this study, cohesive coarse-grained soils were collected from a high-altitude slope in the Qinghai–Tibet Plateau to study the effect of cyclic freeze-thaw on their uniaxial mechanical properties. The soil specimens were remolded with three dry densities and three moisture contents. Then, after performing a series of freeze-thaw tests in a closed system without water supply, the soil specimens were subjected to a uniaxial compression test. The results showed that the stress-strain curves of the tested soils mainly performed as strain-softening. The softening feature intensified with the increasing dry density but weakened with an increase in freeze-thaw cycles and moisture content. The uniaxial compressive strength, resilient modulus, residual strength and softening modulus decreased considerably with the increase of freeze-thaw cycles. After more than nine freeze-thaw cycles, these four parameters tended to be stable. These parameters increased with the increase of dry density and decreased with the increasing moisture content, except for the residual strength which did not exhibit any clear variation with an increase in moisture content. The residual strength, however, generally increased with an increase in dry density. The soil structural damage caused by frozen water expansion during the freeze-thaw is the major cause for the changes in mechanical behaviors of cohesive coarse-grained soils. With results in this study, the deterioration effect of freeze-thaw cycles on the mechanical properties of soils should be considered during the slope stability analysis in high-altitude mountain regions.

关键词： freeze thaw cycles Residual strength Resilient modulus Softening modulus Uniaxial compressive strength Slope stability

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动态文化为骨头工程作为脚手架在 freeze-dried 骨头上改进 MSC 粘附

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World Journal of Stem Cells 2012年第2期4卷 9-16页

作者： Fabiany da Costa Gonalves Ana Helena da Rosa Paz Priscila Schmidt Lora Eduardo Pandolfi Passos Elizabeth Obino Cirne-Lima Embryology and Cell Differentiation Laboratory Hospital de Clínicas de Porto AlegreRua Ramiro Barcelos 2350Porto AlegreRS90035-903Brazil

AIM:To investigate the interaction between mesenchymal stem cells(MSCs) and bone grafts using two different cultivation methods:static and dynamic.METHODS:MSCs were isolated from rat bone marrow.MSC culture was analyzed according to the morphology,cell differentiation potential,and surface molecular markers.Before cell culture,freeze-dried bone(FDB) was maintained in culture for 3 d in order to verify culture medium pH.MSCs were co-cultured with FDB using two different cultivation methods:static co-culture(two-dimensional) and dynamic co-culture(threedimensional).After 24 h of cultivation by dynamic or static methods,histological analysis of Cell adhesion on FDB was performed.Cell viability was assessed by the Trypan Blue exclusion method on days 0,3 and 6 after dynamic or static culture.Adherent cells were detached from FDB surface,stained with Trypan Blue,and quantified to determine whether the cells remained on the graft surface in prolonged non-dynamic culture.Statistical analyses were performed with SPSS and a P 0.05).In histological analysis,there was a significant difference in the amount of adhered cells on FDB between the two cultivation methods(P < 0.05).The MSCs in the dynamic co-culture method demonstrated greater adhesion on the bone surface than in static co-culture method.On day 0,the cell viability in the dynamic system was significantly higher than in the static system(P < 0.05).There was a statistical difference in cell viability between days 0,3 and 6 after dynamic culture(P < 0.05).In static culture,cell viability on day 6 was significantly lower than on day 3 and 0(P < 0.05).CONCLUSION:An alter

关键词： Mesenchymal stem cell Cell culture Cell adhesion Bone matrix freeze drying

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Antioxidants, Chemical Composition and Minerals in freeze-Dried Camu-Camu (<i>Myrciaria dubia</i>(H.B.K.) Mc Vaugh) Pulp

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Food and Nutrition Sciences 2015年第10期6卷 869-874页

作者： Jaime Paiva Lopes Aguiar Francisca das Chagas do Amaral Souza Coordination Society Environment and Health—CSAS National Institute for Amazonian Research—INPA Manaus Brazil

Camu-camu (Myrciaria dubia (H.B.K.) Mc Vaugh) is a fruit native to the Amazon region and is considered the greatest natural source of vitamin C worldwide. It is also a promising source of many phenolic compounds, including flavonoids and anthocyanins. Given the growing rates of chronic non-communicable diseases such as dyslipidemia, obesity and diabetesworldwide, freeze-dried camu-camu can be used for its functional properties, which can reduce the incidence of these diseases. Hence, the objective of this study was to produce freeze-dried camu-camu pulp and present it as an alternative functional food because of its high production and use potential, adding value to this fruit in particular, not very demanded by the food industry. freeze-dried camu-camu pulp is a pink, homogeneous powder with great antioxidant capacity, 52,000 μmol TE/g, six times greater than freeze-dried acai powder. It is also very rich in vitamin C (20.31 g/100g), potassium (796.99 mg/100g), carbohydrates (47.00 g/100g), dietary fiber (19.23 g/100 g), many amino acids, other vitamins, and anthocyanins (0.739 mg/g). The camu-camu freeze-drying process is an effective alternative way to preserve the fruit, preserving its macronutrient and vitamin C contents. Camu-camu is also an excellent source of other bioactive compounds, such as minerals and other phenolic compounds. In conclusion, camu-camu can be used to introduce bioactive compounds into food products and to delay or prevent many human diseases.

关键词： Functional Foods Ascorbic Acid freeze Drying Antioxidant Capacity

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Fatty Acid Composition in freeze-Dried Chinese Mitten Crabs (<i>Eriocheir sinensis</i>)

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Open Journal of Marine Science 2012年第3期2卷 90-95页

作者： Lihong He Feng Li Junyong Tang Department of Cell Biology Medical College Soochow University Suzhou China

freeze drying is reported to be the best method of dehydration. Live fresh Chinese mitten crabs (Eriocheir sinensis) were freeze dried. The moisture content, rehydration ratio, and fatty acid composition of freeze-dried crabs were analysed. The applicability of using freeze drying to process high-value E. sinensis, so as to prolong the time duration of their storage and marketing, were discussed. After lyophilisation, the average moisture content was 6%. The physical properties (shape, size, and colour) of the musculature and viscera were maintained well during freeze drying. The rehydration ratio was 2.15 when rehydrated for 30 min at room temperature. The levels of polyunsaturated fatty acids, especially eicosapentaenoic acid and docosahexaenoic acid, were higher in female freeze-dried crabs than in male crabs. After full rehydration, the fatty acid composition of freeze-dried crabs showed no significant differences to that of frozen crabs after thawing. In conclusion, freeze drying can well preserve the physical properties of the edible parts and fatty acid composition of the viscera in high-value E. sinensis. Rehydration has no destruction of the nutritional value regarding to the fatty acid composition. Therefore, freeze drying is a suitable technique for the processing of high-value E. sinensis.

关键词： Eriocheir sinensis Fatty Acid Composition freeze Drying Frozen Storage Rehydration Ratio Viscera

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freeze女后巷打狗随时蹲3年

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都市生活 2008年第1期 42-43页

作者： sara 杨瑜

被视为"乐坛妖孽"的女子组合 freeze 成员之一石咏莉(Sukie),月前因爱犬失踪一度慌乱至失控狂喊,更不惜贴街招公开手机号码兼出重酬寻狗,可见人狗情深。然而,本刊日前却发现Sukie 与两名 MK Look 的青年,大庭广众对一头雪橇犬施暴。根... 详细信息

被视为"乐坛妖孽"的女子组合 freeze 成员之一石咏莉(Sukie),月前因爱犬失踪一度慌乱至失控狂喊,更不惜贴街招公开手机号码兼出重酬寻狗,可见人狗情深。然而,本刊日前却发现Sukie 与两名 MK Look 的青年,大庭广众对一头雪橇犬施暴。根据《防止残酷对待动物条例》,违例者最高罚款20万及入狱3年,自命爱狗的 Sukie,小心"玩"出火!

关键词： freeze 后巷子组合热心人士云南米线粗言秽语侮辱性言行举止第一时间铜锣湾

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Sublimation-condensation phenomenon in microwave freeze-drying

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Science China(Technological Sciences) 1998年第3期41卷 321-329页

作者：王朝晖施明恒 Department of Power Engineering Southeast University Nanjing China

A sublimation condensation model is developed for microwave freeze drying of unsaturated porous media. The transport properties in the model are analyzed and the model is calculated numerically for the microwave freeze drying of unsaturated porous media. The results show that the effects of sublimation condensation region on drying processes are significant as compared with the traditional sublimation interface model.

关键词： freeze drying microwave heating sublimation condensation region heat and mass transfer.

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Deep freeze软件在公共机房管理与维护方面的应用研究

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中国现代教育装备 2010年第9期 30-33页

作者：赵斌程岩松重庆工商职业学院重庆400052

机房管理与维护是保证学校正常教学活动的基础工作。科学的管理,灵活的技术,会使机房维护工作事半功倍。本文通过一个公共网络机房维护的实例,对Deep freeze软件的特点、使用方法以及用此软件进行系统保护的具体操作过程进行了描述,提... 详细信息

机房管理与维护是保证学校正常教学活动的基础工作。科学的管理,灵活的技术,会使机房维护工作事半功倍。本文通过一个公共网络机房维护的实例,对Deep freeze软件的特点、使用方法以及用此软件进行系统保护的具体操作过程进行了描述,提出了系统维护过程中应当注意的一系列技术性问题。

关键词： Deep freeze 自动还原网络保护公共机房

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