Liquid penetration of freeze-drying and air-drying wood of plantation Chinese fir

A comparative study was conducted on liquid penetration of the freeze-drying and air-drying sapwood and heartwood lumber of plantation Chinese fir （Cunninghamia lanceolata）. The maximum amount of dyeing solution uptake by the capillary rise method was used to evaluate the liquid penetration properties of the treated wood. The pit aspiration ratio was determined by semithin section method. Changes in wood microstructure were investigated using scanning electron microscopy. The results showed that compared with air drying, the freeze drying had a significant effect on liquid penetration of sapwood and heartwood of Chinese fir. The liquid penetration of sapwood is significantly higher than that of the heartwood for both drying treatments. Low pit aspiration ratio and cracks of pits membrane of some bordered pits are the main reasons for increasing liquid penetration after freeze drying treatment.

Preparation of highly dispersed iron species over ZSM-5 with enhanced metal-support interaction through freeze-drying impregnation

Supported metal catalysts play a vital role in the chemical industry, and the metal-support interaction is an important property of the catalyst. However, in the traditional impregnation method, it is difficult to obtain sufficient metal-support interactions owing to the mobility of the metal precursor during evaporation drying. Here, freeze drying is applied during impregnation instead of evaporation drying for enhancing the metal-support interactions. 57 Fe ZSM-5 was chosen as a representative catalyst. A quantitative analysis was conducted based on Mossbauer spectroscopy. Compared with traditional evaporation-drying catalyst, freeze-drying catalyst has stronger metal-support interactions. In addition, more iron species are confined in the channel and smaller metal sizes and less diversity are obtained. The compositional change is also proved because of the superior performance of the freeze-drying catalyst during N2O decomposition. This method can be extended to other supported metal catalysts prepared through an impregnation method, which can be used to tune the metal-support interactions and metal sizes.

Dynamic culture improves MSC adhesion on freeze-dried bone as a scaffold for bone engineering

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 (three-dimensional). 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 was considered significant. RESULTS: The results showed a clear potential for adipogenic and osteogenic differentiation of MSC cultures. Rat MSCs were positive for CD44, CD90 and CD29 and negative for CD34, CD45 and CD11bc. FDBs were maintained in culture for 3 d and the results showed there was no significant variation in the culture medium pH with FDB compared to pure medium pH (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 alternative cultivation method was developed to improve the MSCs adhesion on FDB, demonstrating that dynamic co-culture provides a superior environment over static conditions.

Ag/TiO_2/freeze-dried graphene nanocomposite as a high performance photocatalyst under visible light irradiation

Ag/TiO2/freeze-dried graphene nanocomposites have been prepared via a facile one-step solvothermal method for the photocatalytic degradation of Rh B under visible light irradiation. During the solvothermal process, reduction of graphene oxide and loading of Ag/TiO2nanoparticles on graphene sheets were achieved. Investigation of chemical state of products showed that covering of Ag/TiO2surface with higher weight ratio of graphene resulting in that Ag metals in Ag/TiO2were oxidized to Ag2 O in nanocomposite structure after solvothermal process. Degree of photocatalytic activity enhancement strongly depends on the coverage of Ag/TiO2surface by porous graphene. The sample of 1 wt% porous graphene hybridized Ag/TiO2showed the highest photocatalytic activity, which is related to high migration efficiency of photoinduced of electrons and reduction of electron–hole recombination rate due to high electrical conductivity of graphene. Expanding of absorption to visible light region was ascribed to surface plasmon resonance effect of Ag metals and presence of graphene. Investigation of photocatalytic performance of formic acid as a dye-less organic pollutant showed that dye sensitization effect of Rh B molecules during evaluation of photocatalytic performance was negligible.

Research on Freeze Drying and High-temperature Molding in Medium-temperature Fluorocarbon Board

A research and test system for the carbon anode plate preparation technology was established to optimize the physical and chemical indicators of carbon anode plates,such as bulk density,resistivity,and compressive strength,and improve the operating cycle.In this study,a carbon plate was prepared via a combination of high-temperature molding and freeze drying using a formulation with asphalt content much lower than the industry standard.The experimental results show that the density of the carbon plate is increased by 0.02-0.04 g/cm^(3) by improving the drying method.The carbon plate prepared in the laboratory has a bulk density of 1.814 g/cm^(3),resistivity of 29.8μΩ·m,and compressive strength of 89.27 MPa.The bulk density,room-temperature resistivity,compressive strength,graphitization,and other key indices of the carbon plates made in the laboratory and those procured from a factory in Shanxi,Datong,were tested.Additionally,the specimens were analyzed using thermogravimetry-differential scanning calorimetry,scanning electron microscopy,and X-ray fluorescence.The laboratory-made carbon plates were superior to the factory specimens in terms of all the indicators tested.The process in this study improves the performance of the carbon anode plate and is used to provide technical support for electrolytic fluorine production in enterprises.The carbon plates prepared in the laboratory fully meet the process requirements of a medium-temperature electrolytic fluorine production line,which indicates the possibility of its use in the stable production of fluorine gas.

Study of self-made freeze-dried bilayered fibrin-binding amniotic membrane in ocular trabeculectomy in rabbits

AIM: To investigate the antifibrotic effect of freeze-dried bilayered fibrin-binding amniotic membrane on trabeculectomy in a rabbit model. METHODS: Twenty-four Japanese white rabbits were randomized into three groups: the experimental group (ocular trabeculectomy in combination with freeze-dried bilayered fibrin-binding amniotic membrane transplantation), the control group (ocular trabeculectomy in combination with natural bilayered fibrin-binding amniotic membrane) and the blank group (single trabeculectomy). Clinical observation, hematoxylin-eosin staining, Massion staining, real-time PCR and immunohistochemistry for alpha -SMA were performed on days 7, 14, 21 and 30 following surgery. RESULTS: Statistical differences were noted in survival. analysis and intraocular pressure(IOP) among groups on days 7, 14, 21 and 30 following surgery. Histology, immunohistochemistry and real-time PCR further demonstrated that trabeculectomy in combination with freeze-dried bilayered fibrin-binding amniotic membrane resulted in good wound healing and no scar formation. CONCLUSION: Self-made freeze-dried bilayered fibrin-binding amniotic membrane may inhibit the formation of scarring in glaucoma after trabeculectomy.

Efficacy of Yiqi Fumai (Freeze-Dried Powder) on Ischemic Diastolic Heart Failure

Objective: To evaluate the efficacy of Yiqi Fumai freeze-dry powder (YFP) on ischemic diastolic heart failure. Methods: 100 patients diagnosed with unstable angina accompanying ischemic diastolic heart failure (IDHF) were selected randomly. 52 patients with TCM syndrome of qi-yin deficiency were divided into Chinese and Western combination therapy group. 48 patients have no TCM syndrome of qi-yin deficiency, and were treated with standard western medicine. After treatment, Seattle Angina Questionnaire Evaluation, ECG, conventional and stress echocardiography (SE) index, NT-proBNP were compared between before and after treatment. Results: The differences of PL, TS, DP between before and after treatment by YFP were statistically significant

Optimization of Freeze-drying Protective Agents for Lactobacillus plantarum KLDS1.0391 by Response Surface Methodology

In this study, the Single Factor Test（SFT） was used to optimize the pre-freezing conditions of L. plantarum KLDS1.0391（KLDS1.0391）. Further, the Freeze-Drying Protective Agents（FDPA） of KLDS1.0391 was optimized by Response Surface Methodology（RSM）. The optimum pretreatment conditions were as the follows： initial concentration of KLDS1.0391 was 1011 CFU · m L-1 and KLDS1.0391 was pre-freezed at –80℃ for 8 h to achieve the survival rate of 46.21%. The main components of FDPA were skim milk, sucrose, sodium glutamate and Tween-80. And the influence of four factors on the survival rate of KLDS1.0391 in freeze-drying was in order as the follows： skim milk〉sucrose〉Tween-80〉sodium glutamate. The optimal FDPA composition was skim milk 11.3%, sucrose 9.8%, sodium glutamate 5.1% and Tween-80 0.2%. Under the above conditions, the survival rate of the cells was 82.98%. Comparing the predicted values, the relative error was 0.37% and the difference was not significant, which indicated that the established model could effectively reflect the actual protection of FDPA to KLDS1.0391.

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

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.

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

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.

Physicochemical Properties and Sensory Evaluation of Sponge Cake Supplemented with Hot Air and Freeze Dried Oyster Mushroom (<i>Pleurotus sajor-caju</i>)

The study was aimed to enhance the nutritional quality of sponge cakes with oyster mushroom (Pleurotus sajor-caju). In this study, the physicochemical, functional, and sensory properties of cake supplemented with five different levels of mushroom powder (0 as control, 5%, 7%, 10%, and 12%) were evaluated. The results revealed that both hot air dried (HD) and freeze dried (FD) mushroom powder contained a higher amount of protein, fat, ash and fiber ontent compared with wheat flour used in cake, but the carbohydrate and moisture content showed the reverse trend. The study also found that increasing the level of fortification from 0% to 12% mushroom powder also increased the protein, fat, ash, and fiber content in the cake. FD mushroom powder significantly (p ≤ 0.05) recorded the highest protein (11.72% - 15.16%), fat (20.01% - 21.9%), ash (1.75% - 1.92%), and fiber (1.39% - 1.74%) with increasing the level of supplementation from 5% - 12%. In contrast, carbohydrate content of cake decreased from 34.13% - 31.15% with increasing the level of FD mushroom from 5% - 12%. Also, the volume and weight of the cake with FD mushroom were higher compared to HD and control sample. The results of sensory evaluation indicated that sponge cake with 10% FD oyster mushroom was rated the most acceptable after the control.

The Study on Technique of Making Freeze-dried Specimen of Mongolia Horse

冻干标本是在冷态条件下制作的,其方法为:迅速且完全地冷冻所选材料,待其干燥后进行加工。此方法比较简单且能真实的反应组织的位置、形状及它们的关系。以蒙古马为实验材料介绍了冻干标本工艺,以及如何保存维护冻干标本的方法。

沙库巴曲缬沙坦联合冻干重组人脑利钠肽治疗心力衰竭的疗效及对NT-proBNP的影响

目的探讨沙库巴曲缬沙坦联合冻干重组人脑利钠肽治疗心力衰竭的疗效及对NT-proBNP的影响。方法选取2022年4月至2023年5月云南省昆明市第一人民医院心内科收治的150例心力衰竭患者为研究对象,根据就诊时间分为两组。参照组采用沙库巴曲缬沙坦治疗,实验组在参照组基础上使用冻干重组人脑利钠肽治疗。对比两组治疗效果、心功能、血浆BNP、NT-proBNP水平及不良反应发生情况。结果实验组治疗总有效率高于参照组,差异有统计学意义(P<0.05)。实验组干预后心率低于参照组,每搏量及LVEF均高于参照组,差异有统计学意义(P<0.05)。实验组干预后血浆BNP、NT-proBNP水平均低于参照组,差异有统计学意义(P<0.05)。实验组不良反应发生率低于参照组,差异有统计学意义(P<0.05)。结论沙库巴曲缬沙坦联合冻干重组人脑利钠肽治疗心力衰竭可显著提高疗效,降低血浆BNP及NT-proBNP水平,改善患者心功能,减少不良反应。

Structural and functional properties of hydrolyzed/glycosylated ovalbumin under spray drying and microwave freeze drying

Ovalbumin(OVA),the main protein in egg white,affects most of the functional properties of egg white protein in food processing.The aim of this study was to investigate the effects of spray drying(SD)and microwave freeze drying(MFD)on the preparation of hydrolyzed/glycosylated ovalbumin(HGOVA)and provide useful information on the applications of egg protein powders in the food industry.Results demonstrated that the structure of HGOVA was considerably changed,and its functional properties were improved compared with those of native OVA.SD and MFD processing did not lead to dissociation of HGOVA subunits.SD-HGOVA exhibited higher protein solubility,emulsifying activity,foaming capacities,and gel hardness than MFD-HGOVA.However,MFD-HGOVA was better than the SD-HGOVA in terms of color,emulsion stability,foam stability,water/oil absorption capacity,and thermal stability.Selection of an appropriate drying method could enhance the potential applications of HGOVA in the food industry.

Optimization of Process Parameters of Continuous Microwave Drying Raspberry Puree Based on RSM and ANN-GA

To improve drying uniformity and anthocyanin content of the raspberry puree dried in a continuous microwave dryer,the effects of process parameters(microwave intensity,air velocity,and drying time)on evaluation indexes(average temperature,average moisture content,average retention rate of the total anthocyanin content,temperature contrast value,and moisture dispersion value)were investigated via the response surface method(RSM)and the artificial neural network(ANN)with genetic algorithm(GA).The results showed that the microwave intensity and drying time dominated the changes of evaluation indexes.Overall,the ANN model was superior to the RSM model with better estimation ability,and higher drying uniformity and anthocyanin retention rate were achieved for the ANN-GA model compared with RSM.The optimal parameters were microwave intensity of 5.53 W•g^(-1),air velocity of 1.22 m·s^(-1),and drying time of 5.85 min.This study might provide guidance for process optimization of microwave drying berry fruits.

葡聚糖-铁蛋白-白藜芦醇纳米粒子稳定的多重乳液处理对冻干苹果片品质的影响

为实现营养物质有效递送并提高冻干苹果片的品质,制备了葡聚糖-铁蛋白-白藜芦醇纳米粒子稳定的多重乳液,有效负载绿原酸、虾青素及白藜芦醇后,以其预处理苹果片并分析其对冻干苹果片品质的影响。结果表明,葡聚糖-铁蛋白-白藜芦醇纳米粒子中白藜芦醇包封率为(9.74±0.03)%,葡聚糖的接枝度为32.64%;制备得到的乳液外观均一,液滴均匀。用该乳液处理苹果片后,与对照组相比,冻干苹果片的亮度和硬度显著增高(P<0.05),吸湿性与水分活度降低。乳液浸泡1 h后冻干苹果片的总糖、总酸、维生素C含量均显著升高(P<0.05),且对1,1-二苯基-2-三硝基苯肼(1,1-Diphenyl-2-picrylhydrazyl,DPPH)自由基、羟自由基清除率及对多酚氧化酶抑制率均显著增强(P<0.05)。该研究成功制备了葡聚糖-铁蛋白-白藜芦醇纳米粒子稳定的多重乳液,在有效递送绿原酸、虾青素及白藜芦醇的同时,提升了冻干苹果片的品质,为实际生产应用提供了一定的理论指导。

桑葚-紫薯复合冻干果块的制备工艺优化及品质评价

传统冻干产品加工工艺技术含量低,产品配方、营养和口味单一,市场同质化现象严重,日渐无法满足消费者的需求。为增加市面上复合型果蔬冻干产品的多样性,丰富冻干产品的口感和营养价值,该研究以桑葚和紫薯为主要原料,采用真空冷冻干燥技术,使用Box-behnken结合综合评分法,探究了果胶、阿拉伯胶、麦芽糊精、果葡糖浆和柠檬酸添加量对桑葚-紫薯复合冻干果块综合评分的影响。结果表明,最佳制备工艺为:果胶添加量0.20%、麦芽糊精添加量8.00%、阿拉伯胶添加量0.20%、果葡糖浆添加量4.00%和柠檬酸添加量0.24%,综合评分为0.87分。工艺优化后的产品总体感官可接受度8.90分,比未添加辅料的复合冻干果块显著(P<0.05)提高了25.35%。同时,所得复合冻干果块具有良好的品质,其脆度、总黄酮含量、总花青素含量及铁离子还原能力分别显著(P<0.05)提高了80.53%、23.10%、11.36%和39.95%。研究结果可以为复合型冻干果蔬产品的发展提供一定的理论依据。

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

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.

Preservation of moderately thermophilic culture by freeze drying and frozen preservation way and effect on subsequent bioleaching of chalcopyrite

Freeze drying and frozen preservation way was used to preserve a moderately thermophilic culture for bioleaching of chalcopyrite concentrate.After preservation of 15 months,the cell viability rate decreases to 22% with a cell density of 7×107 mL-1.When the growth time was extended from 8 days to 14 days,cell density would increase in a large scale to about 3×108 mL-1.In the bioleaching experiments,unpreserved and preserved cultures were compared for dissolving chalcopyrite concentrate.Before 44 days,the unpreserved culture can reach a high copper extraction of about 17.4 g/L.While the preserved culture shows a rather low copper extraction,which is only 9.7 g/L.When the bioleaching time was extended to 80 days,copper extraction by preserved culture increases remarkably,and the concentration of copper finally achieves up to 18.3 g/L.On the other hand,copper extraction by the unpreserved culture does not show remarkable increase from 44th to the 80th day,and finally the total copper extraction is 19.8 g/L.As a result,total copper extraction in 80 days by preserved culture approaches that by unpreserved culture and freeze drying and frozen preservation even after 15 months does not bring much decrease of bioleaching ability.

冻干重组人脑利钠肽联合呋塞米注射液治疗心力衰竭的效果及对血清PCT、NT-proBNP水平的影响

目的:探讨冻干重组人脑利钠肽联合呋塞米注射液治疗心力衰竭患者的效果及对其血清降钙素原(PCT)、N末端脑钠肽前体(NT-proBNP)水平的影响。方法:选取2019年1月—2022年12月于泰州市第四人民医院接受救治的心力衰竭患者86例为研究对象,根据患者入院日期进行编号,其中43例奇数日期入院的患者纳入对照组,接受呋塞米注射液治疗,另外43例偶数日期入院的患者纳入试验组,接受冻干重组人脑利钠肽联合呋塞米注射液治疗。比较两组临床治疗总有效率、心功能指标[左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)及左心室射血分数(LVEF)]、血液指标(PCT、NT-pro BNP)、生活质量。结果:试验组总有效率为95.35%,明显高于对照组的81.40%,差异有统计学意义(P<0.05)。治疗前,两组LVEDD、LVESD及LVEF水平比较,差异无统计学意义(P>0.05);治疗后,两组LVEDD、LVESD水平均较治疗前降低,LVEF水平较治疗前升高,且试验组LVEDD、LVESD水平低于对照组,LVEF水平高于对照组,差异有统计学意义(P<0.05)。治疗前,两组PCT、NT-proBNP水平比较,差异无统计学意义(P>0.05);治疗后,两组PCT、NT-proBNP水平均较治疗前降低,试验组均低于对照组,差异有统计学意义(P<0.05)。治疗前两组生理功能、健康状况、情感职能、社会功能、躯体疼痛、生理职能、精神健康、精力评分比较,差异无统计学意义(P>0.05);治疗后,两组上述各维度评分均较治疗前升高,且试验组均高于对照组,差异有统计学意义(P<0.05)。结论:冻干重组人脑利钠肽与呋塞米注射液联合治疗心力衰竭患者,其临床治疗总有效率明显提高,心功能明显提升,PCT、NT-proBNP指标水平明显改善,生活质量提高。