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【Objective】 To investigate the effects of platelet activation pathways on the characterization of platelet-derived extracellular vesicles(PEVs). 【Methods】 Whole blood from healthy donors was prepared into platelet suspension by centrifugation. Platelets were randomly divided into six groups, the ctrl group added no extra stimulus, and the other five groups were treated with collagen, adenosine diphosphate(ADP), thrombin, Ca2+ ionophore and freeze-thaw cycles (F-T) to activate platelets. Platelet-derived exosomes(PEXOs) and microvesicles(PMVs) were isolated by differential centrifugations, and then were determined by nano-flow cytometry and electron microscopy. The protein markers of PEXOs also were identified by western-blot. The protein concentration and content of PEXOs were also detected. 【Results】 CD9, CD81, TSG101 proteins were detected in all of the PEXOs, which had no calnexin. Both PEXOs and PMVs had CD41; PEXOs were cup-holder-like bilayer membrane vesicles under a transmission electron microscope, while PMVs were irregular membranous structure; 85%-95% of PEXOs were<100nm, 87%-94% of PMVs were 100-300nm. The concentration of exosomes and microvesicles in the F-T group was the highest(205.67±65.27 and 102.73±15.48), followed by the Ca2+ ionophore group(44.42±17.07 and 11.4±4.81). Although in the same size range, the numbers of PEVs induced by different activation conditions varied. The protein concentration of PEXOs in the F-T group(1.11±0.51) was higher than that in the control group(0.32±0.39), ADP group(0.41±0.31) and thrombin group(0.38±0.37), while the total protein(125.40±58.32) was higher than that in other three groups(the ctrl group 25.53±25.96 vs ADP group 37.21±15.73 vs thrombin group 36.28±24.18 vs Ca2+ ionophore group 47.09±23.29). 【Conclusion】 The biological characteristics of PEVs are affected by platelets activation pathways, whose ability to induce protein-packing into exosomes may also be relevant to the particle size. The freeze-thaw cycles can induce high concentrations of extracellular vesicles, which may be an ideal method for the preparation of PEVs.
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Platelet-rich fibrin(PRF), a second-generation of platelet concentrate with stereo fibrin structure, leukocyte and platelets, can release various cytokines and growth factors to promote wound healing. PRF has been widely used in the treatment of various acute and chronic wounds in traumatic surgery, plastic surgery and stomatology. Chronic wounds are common in traumatic surgery, but conventional treatment is often ineffective. Accumulating evidences have confirmed that PRF has excellent therapeutic effect on chronic wounds. According to various methods such as different specimen, centrifugation, centrifuge tube material, and freeze-drying, the researchers tried to improve the efficiency of PRF. The progress of platelet-rich fibrin preparation technology and preservation technology are reviewed in this paper.
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@#Objective To evaluate the safety and immunogenicity of pre-exposure prophylaxis of the approved freeze-dried rabies vaccine(Vero cell)(rabies vaccine in brief)for human use in adults ≥18 years of age.Methods Participants aged ≥18 years in Guizhou and Shanxi provinces from June 2022 to September 2022 were enrolled,vaccinated with 1 dose of rabies vaccine at 0,7,28 d respectively,and collected for 5. 0 mL of venous blood before the first dose and 14 d after the third dose. Immunofluorescence foci assay was used to detect rabies virus neutralizing antibodies,and adverse events were collected 0～7 d after each dose of vaccine.Results A total of 120 participants were enrolled,120 participants received the first dose of rabies vaccine,119 participants received the second dose and 118 participants received the third dose.Before the first dose of rabies vaccine,the seropositive rate of antibody was 2. 54% and the geometric mean concentration(GMC)was 0. 40 IU/mL. After the third dose of rabies vaccine,the seropositive rate and seroconversion rate were 100%,the GMC was 9. 68 IU/mL,and the geometric mean increase(GMI)was 23. 99. The incidence of adverse events 0～7 d after the first,second and third doses of rabies vaccine were 22. 50%,13. 45% and 4. 24%,respectively. The local adverse events were mainly pain,and the systemic adverse events were mainly fever,fatigue/weakness,dizziness,joint pain,and diarrhea.Conclusion Approved rabies vaccine showed good safety and immunogenicity in pre-exposure prophylaxis of people ≥ 18 years old.
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@#Objective To screen the formulation of heat-resistant protective agent for live classic swine fever(CSF) vaccine in order to prolong the preservation time of vaccine under harsh conditions.Methods The heat-resistant protective agent prepared based on the formula containing gelatin,D-sorbitol,trehalose,D casein hydrolysate of different contents was mixed with the live virus antigen of CSF and then lyophilized.The finished products with qualified appearance were screened for routine detection and aging resistance test,and the over-dose(10 and 30 portions) of the products qualified in the aging resistance test were used to immunize piglets via subauricular neck,5 for each to evaluate the safety of the vaccines.Results Among the 6 batches of lyophilized live CSF vaccine,3 batches(20200301,20200302 and 20200303) met the requirements of the current Chinese Veterinary Pharmacopoeia.The lyophilized loss was within 0.04～0.33 titers,and the moisture contents were all less than 2%;20200301 and 20200302 batches of finished products passed the aging resistance test.No adverse clinical symptoms were observed in all piglets 30 min after vaccination;The body temperatures of piglets vaccinated with 10 and 30 doses of vaccine were normal for 14 d after vaccination.Conclusion The two formulations of heatresistant protective agent selected might be used for freeze-dried preparations of live CSF vaccine with good effect of aging resistance and safety to piglets.
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OBJECTIVE To optimize the preparation process of Soft-shelled turtle blood lyophilized powder （STBLP）， and to provide a reference for improving the availability and quality stability of soft-shelled turtle blood （STB）. METHODS STBLP was prepared with vacuum freeze-drying. Taking the solubility as the index， the preparation process parameters of STBLP were optimized by single factor experiment and Box-Behnken response surface method. RESULTS The optimal freeze-drying process for STBLP was obtained： pre-freezing time of 4 h， total drying time of 13 h （before at 0 ℃）， and resolution drying temperature of 25 ℃. The average solubility of 3 batches of STBLP prepared according to the optimal process was 95.72% （RSD＝0.68%， n＝3）， the relative error of which was －0.97% to the theoretical solubility （96.66%）. CONCLUSIONS Optimized lyophilization process in this study are stable and feasible， the solubility of the prepared sample is high.
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@#Objective To develop and validate size exclusion column-high performance liquid chromatography(SEC-HPLC)for determination of the purity of bulk material of freeze-dried rabies vaccine for human use.Methods Chromatography column TSK-gel G6000PW_(XL)(7.8 mm × 30 cm,13 μm)was used for the determination(column temperature 30 ℃)with mobile phase of 0.1 mol/L PB buffer(pH 7.8)at a flow rate of 0.5 mL/min.The detection wavelength was 280 nm and injection volume was 20 μL.The method was validated for system suitability,specificity,precision and durability and determined for detection limit and quantitation limit,which was applied to analyze bulk material purity of freeze-dried rabies vaccine for human use of 3 batches of Vero cells and 1 batch of human diploid cells.Results The resolution of target protein spectrum peak of bulk material of reference sample and freeze-dried rabies vaccine for human use prepared with two substrates was more than 1.5 with a tailing factor less than 1.5;The blank solvent showed no absorption peak at the position of target protein peak with no interference in the determination;The RSDs of retention time and peak area in precision verification were both less than 2.0%;The quantitative limit was 10 μg/mL,and the detection limit was 4 μg/mL;The reference sample was injected three times continuously at three different detection wavelengths of 278,280 and 282 nm,and the RSDs of retention time and peak area were also less than 2.0%.The purity of 4 batches of freeze-dried rabies vaccine bulk material for human use was all more than 97%.Conclusion The developed SEC-HPLC for determination of the purity of freeze-dried rabies vaccine bulk material for human use showed good specificity,precision and durability,which provided a reliable method for the quality control of human rabies vaccine.
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ObjectiveTo study the differences in volatile oil content of bran-processed Atractylodes lancea and its standard decoction concentrate and freeze-dried powder， as well as the differences in the types and contents of chemical components in volatile oil， and to clarify the quality value transmitting. MethodTen batches of A. lancea rhizoma were collected and prepared into raw products and bran-processed products of A. lancea， standard decoction concentrate and freeze-dried powder of bran-processed A. lancea in order to extract the volatile oil， and the transfer rate of volatile oil in each sample was calculated. Quantitative analysis of the main chemical components（β-eudesmol， atractylon， atractylodin） in each volatile oil was performed by gas chromatography（GC） on the HP-5 quartz capillary column（0.32 mm×30 m， 0.25 μm） with a flame ionization detector（FID）， a split ratio of 10∶1 and a temperature program（initial temperature at 80 ℃， hold for 1 min， rise to 150 ℃ at 10 ℃·min-1， hold for 10 min， rise to 155 ℃ at 0.5 ℃·min-1， hold for 5 min， rise to 240 ℃ at 8.5 ℃·min-1， hold for 8 min）. Cluster analysis and principal component analysis（PCA） were used to explore the overall differences in types and contents of chemical components between the standard decoction concentrate and freeze-dried powder. ResultThe transfer rates of volatile oil in the bran-processed products， standard decoction concentrate and freeze-dried powder were 70.51%， 1.57% and 40.90%， respectively. The average transfer rates of β-eudesmol， atractylon and atractylodin in the volatile oil of bran-processed A. lancea were 58.45%， 48.49% and 55.64%， respectively. In the standard decoction concentrate， only β-eudesmol and atractylodin were detected， and their average transfer rates were 0.22% and 0.10%， respectively. And only β-eudesmol was detected in the freeze-dried powder with the average transfer rate of 8.37%. The results of cluster analysis and PCA showed that there are obvious differences in the types and contents of chemical components between the standard decoction concentrate and freeze-dried powder. ConclusionThe quality value transmitting between bran-processed A. lancea and its standard decoction concentrate and freeze-dried powder is stable， and if the freeze-dried powder is selected as the reference material of dispensing granules， appropriate amount of volatile oil should be added back to make it consistent with the quality of the standard decoction concentrate.
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Abstract Objective It is known that the single embryo transfer (SET) is the best choice to reduce multiples and associated risks. The practice of cryopreserving all embryos for posterior transfer has been increasingly performed for in vitro fertilization (IVF) patients at the risk of ovarian hyperstimulation syndrome or preimplantation genetic testing for aneuploidy. However, its widespread practice is still controverse. The aim of this study was to evaluate how effective is the transfer of two sequential SET procedures compared with a double embryo transfer (DET) in freeze-only cycles. Methods This retrospective study reviewed 5,156 IVF cycles performed between 2011 and 2019, and 506 cycles using own oocytes and freeze-only policy with subsequent elective frozen-thawed embryo transfers (eFET) were selected for this study. Cycles having elective SET (eSET, n = 209) comprised our study group and as control group we included cycles performed with elective DET (eDET, n = 291). In the eSET group, 57 couples who had failed in the 1st eSET had a 2nd eFET, and the estimated cumulative ongoing pregnancy rate was calculated and compared with eDET. Results After the 1st eFET, the ongoing pregnancy rates were similar between groups (eSET: 35.4% versus eDET: 38.5%; p =0.497), but the estimated cumulative ongoing pregnancy rate after a 2nd eFET in the eSET group (eSET + SET) was significantly higher (48.8%) than in the eDET group (p < 0.001). Additionally, the eSET +SET group had a 2.7% rate of multiple gestations, which is significantly lower than the eDET group, with a 30.4% rate (p < 0.001). Conclusion Our study showed the association of freeze-only strategy with until up to two consecutive frozen-thawed eSETs resulted in higher success rates than a frozenthawed DET, while drastically reducing the rate of multiple pregnancies.
Resumo Objetivo Sabe-se que a transferência de embrião único (SET) é a melhor escolha para reduzir as gestações múltiplas e riscos associados. A prática da criopreservação de todos os embriões para transferência posterior tem sido cada vez mais utilizada para fertilização in vitro (FIV), em especial quando há risco de síndrome de hiperestimulação ovariana ou realização de teste genético pré-implantacional. Entretanto, sua utilização disseminada ainda é controversa. O objetivo deste estudo foi avaliar a eficácia de duas SET sequenciais em comparação com uma transferência de embrião dupla (DET) em ciclos de FIV onde todos os embriões foram criopreservados. Métodos Neste estudo retrospectivo foram revisados 5.156 ciclos de FIV realizados entre 2011 e 2019, e 506 ciclos usando oócitos próprios e criopreservação de todos os embriões com transferências eletivas subsequentes de embriões descongelados, foram selecionados para este estudo. Ciclos com transferência eletiva de embrião único (eSET, n = 209) compuseram nosso grupo de estudo e como grupo de controle incluímos os ciclos com transferência eletiva de dois embriões (eDET, n = 291). No grupo eSET, 57 casais que falharam na 1ª tentativa de eSET tiveram uma 2ª eFET e a taxa de gravidez em curso cumulativa foi estimada para o grupo eSET e comparada com o grupo eDET. Resultados Após a 1ª eFET, as taxas de gravidez em curso foram semelhantes entre os grupos (eSET: 35,4% versus eDET: 38,5%; p = 0,497), mas a taxa de gravidez em curso cumulativa estimada após a 2ª eFET no grupo eSET (eSET + SET) foi significativamente maior (48,8%) do que no grupo eDET (p <0,001). Além disso, as taxas de gestação múltipla foram expressivamente inferiores no grupo eSET + SET (2,7%) quando comparado ao grupo eDET (30,4%; p < 0,001). Conclusão Nosso estudo mostrou que a associação das estratégias de congelamento de todos os embriões com até duas eSETs sequenciais resultou em maiores taxas de sucesso do que uma DET com embriões descongelados, além de reduzir drasticamente a ocorrência de gestações múltiplas.
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Humanos , Feminino , Gravidez Múltipla , Fertilização in vitro , Taxa de Gravidez , Transferência de Embrião ÚnicoRESUMO
Introdução: o uso de substitutos cutâneos para o tratamento de diversas feridas graves é uma forma eficiente de prevenir infecções e favorecer o processo de reepitelização. No entanto, tecidos biológicos estão suscetíveis a degradação e contaminação. Por isso, devem ser submetidos a rigorosos protocolos de processamento e testes que comprovem suas contribuições benéficas e segurança de aplicação. Objetivo: trazer uma abordagem sobre as principais características dos métodos de criopreservação, glicerolização e liofilização e sua consequencia nos aspectos imunológicos, microbiológicos e de viabilidade tecidual de enxertos de pele humana. Metodologia: foi realizada uma busca online utilizando as palavras chaves "criopreservação", "liofilização", "glicerolização", "enxertos", "processamento tecidual" e "engenharia dos tecidos" em múltiplas combinações nos bancos de dados PubMed, LILACS e ScienceDirect. Resultados: 200 artigos científicos foram obtidos, 26 excluídos por duplicidade, 92 selecionados para leitura integral a partir da leitura de seus resumos e 27 utilizados na construção desta revisão. A liofilização e a glicerolização são métodos semelhantes considerando a viabilidade tecidual. O uso de glicerol traz como principal desvantagem sua citotoxicidade quando comparado aos outros métodos. A criopreservação mantém os tecidos viáveis. Contudo, pode ser mais cara e trazer riscos de transmissão de microorganismos patogênicos. De modo geral, não é bem estabelecido quais os melhores métodos de conservação para uma adequada conservação da viabilidade dos enxertos de pele. Considerações Finais: os 3 métodos, liofilização, glicerolização e criopreservação, possuem aplicabilidade na conservação de enxertos. A falta de padronização na aplicação de enxertos apesar de sua frequente aplicação e a escassez de estudos recentes sobre o tema justificam o presente estudo.
Introduction: the use of skin substitutes for treatment of several wounds is an efficient way to prevent infections and allow the re-epithelialization process. However, biological tissues are susceptible to degradation and contamination. Therefore, they must undergo rigorous processing and testing protocols that prove their beneficial contributions and application security. Objective:to bring an approach on the main characteristics of cryopreservation, freeze-drying and glycerol conservation methods and their implications on immunological, microbiological and tissue viability aspects when applied to human skin grafts. Methodology:a mostly online search was performed using the keywords "cryopreservation", "freeze-drying", "glycerol conservation", "grafts", "tissue processing" and "tissue engineering" in multiple combinations in PubMed, LILACS and ScienceDirect databases. Results: 200 scientific articles were rescued, 26 excluded by duplicity, 92 selected for full reading from the reading of their abstracts and 27 used in the construction of this review. Freeze-drying and glycerol conservation are similar methods, with glycerol conservation having greater economic advantage. The use of glycerol presents cytotoxicity when compared to the other methods. Cryopreservation keeps tissues viable, however, is more expensive and carry risks of transmission of pathogenic microorganisms. Overall, there is a lack of clarity about the importance of viability in the performance of skin grafts. Final considerations: the 3 methods have applicability in graft conservation. The lack of standardization in graft application despite its frequent application and the scarcity of recent studies on the subject justify the present study.
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Humanos , Criopreservação/métodos , Crioprotetores , Retalhos de Tecido Biológico , Aloenxertos , Glicerol , Liofilização/métodosRESUMO
ObjectiveTo compare the effects of different drying methods on volatile components of Pseudostellariae Radix. MethodThe samples were dried by different methods， including air drying， sun drying， hot air drying （40， 60， 80 ℃） and vacuum freeze drying. Gas chromatography-ion mobility spectrometry （GC-IMS） was used to compare the changes of volatile components in the samples after different treatments. The samples were incubated at 80 ℃ and 500 r·min-1 for 15 min， the injection temperature was 85 ℃， the injection volume was 200 μL， the flow rate of carrier gas was from 2 mL to 150 mL during 20 min， and the temperature of IMS detector was 60 ℃. SE-54 capillary column （0.32 mm×30 m， 0.25 μm） was used， the column temperature was 60 ℃， and the analysis time was 35 min. The differential spectra of volatile components were constructed and analyzed by principal component analysis （PCA）. ResultA total of 37 volatile components were identified from dried Pseudostellariae Radix. The number of compounds in descending order was ketones， aldehydes and alcohols. There were some differences in the volatile components in samples dried by different methods. And the volatile components in samples with sun drying， air drying and hot air drying at 40 ℃ were similar， compared with other drying methods， vacuum freeze drying and hot air drying at 80 ℃ had great effects on the volatile components of Pseudostellariae Radix， and the compounds in the samples with vacuum freeze drying were the least. ConclusionIn this study， GC-IMS for the detection and analysis of volatile components in Pseudostellariae Radix is established， which has the characteristics of high efficiency， nondestructive inspection and simple sample processing. This method can be used for the distinction of Pseudostellariae Radix dried by different methods. And hot air drying at 40 ℃ can effectively retain the volatile components of Pseudostellariae Radix， and achieve similar flavor to samples with sun drying and air drying.
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Intrinsically disordered proteins (IDPs) are proteins or protein regions that fail to get folded into definite three-dimensional structures but participate in various biological processes and perform specific functions. Defying the traditional protein "sequence-structure-function" paradigm, they enrich the protein "structure-function" diversity. Ubiquitous in organisms, they show extreme hydrophilicity, charged amino acids, and highly repetitive amino acid sequences, with simple arrangement. As a result, they feature highly variable binding affinities and high coordination, which facilitate their functions. IDPs play an important role in cell stress response, which can improve the tolerance to a variety of stresses, such as freezing, high salt, heat shock, and desiccation. In this study, we briefed the characteristics, classifications, and identification of IDPs, summarized the molecular mechanism in improving cell stress resistance, and described the potential applications.
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Congelamento , Proteínas Intrinsicamente Desordenadas/metabolismo , Conformação ProteicaRESUMO
Recombinant humanized anti-ricin monoclonal antibody (MIL50) is a recombinant humanized monoclonal antibody targeting ricin. In this study, an ELISA method was used to establish a method for the determination of MIL50 in macaque serum, and a cross design method was used. Twelve rhesus monkeys were intravenously injected 1 mg·kg-1 test preparation (MIL50 freeze-died powder injection) and reference preparation (MIL50 liquid preparation) to determine the plasma concentration of MIL50 at different time points, and the pharmacokinetic parameters were analyzed to compare the pharmacokinetic characteristics of MIL50 liquid preparation and freeze-died powder injection in rhesus monkeys. Animal welfare and experimental procedures follow the regulations of the Animal Ethics Committee of the Chinese Academy of Medical Sciences and Use of Laboratory Animals and the regulations derived by the Animal Care and Welfare Committee of the Institute of Radiation Medicine, Academy of Military Medical Sciences (IACUC-DWZX-2020-503). The results showed that there was no significant difference between Cmax and AUC0-5d in the two groups. The liquid preparation was the reference preparation, with Cmax ratio of 101.6% and AUC0-5d ratio of 101.9%, the 90% confidence interval of Cmax was 79.42%-129.92%, and the 90% confidence interval of AUC0-5d was 85.72%-121.18%. These results suggested that different dosage forms of MIL50 had certain differences in the changes of blood drug concentration in rhesus monkeys.
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Aim To study the application of HL-60 monocyte activation test in the pyrogen detection of freeze-dried rabies vaccine for human use.Methods The established HL-60 mononuclear cell activation test (MAT) was transferred between laboratories and the method was verified; referring to the interference test in the photometric method of the bacterial endotoxin test method of the Chinese Pharmacopoeia, HL-60- IL- 6 MAT was used to detect the recovery and pyrogen content of 13 batches of freeze-dried rabies vaccine for human use.Results The linearity of the amount of 1L-6 secreted by HL-60 cells, which stimulated by dif¬ferent concentrations of endotoxin standards was above 0.95; the calculated minimum detection limit was not more than 0.125 EU • mL"1 ; the recovery experiment with a solution containing 0.5 and 1.0 EU • mL"1 of endotoxin was performed to cheek the accuracy of the method.HL-60-IL-6 was used to detect 13 hatches of Freeze-dried rahies vaccine for human use, and the re¬covery of endotoxin was between 50 % to 200%.It was consistent that HL-60-IL-6 with pyrogens and en¬dotoxin test for 4 batches of freeze-dried rabies vaccine for human use which pyrogens and endotoxin test failed and the 3 batches of water for injection.Conclusion The HL-60 MAT using IL-6 as a detection indicator is suitable for the detection of pyrogenic substances in freeze-dried rabies vaccine for human use.
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Background: One of the most used and effective preservation strategies in foods is drying. However, there are problems with the rheological properties, color, and viability of lactic acid bacteria in the yogurt once reconstituted when applying such conservation strategies. Objectives: Determine the concentration of the type of texture improver and drying that minimizes the negative effect on the rheological, color, and microbiological properties of a reconstituted yogurt powder. Methods: Intended to determine the texture improver which increases rheological properties of reconstituted yogurt powder, a mixture type experimental design was applied where three texture improvers were assessed; carboxymethylcellulose (CMC) (mass fraction 0 - 1), pectin (mass fraction 0 - 1), and xanthan gum (mass fraction 0 - 1). The rheological parameters; consistency index (K), flow behavior (n), viscosity at 100s-1 (η), the storage (G') and loss (G'') modules, and the phase shift angle (δ) of each of the reconstitutions were considered as design-dependent variables. Secondly, a central composite design (face-centered) was used for assessing the effectiveness of the drying (convection, spray-drying, and freeze-drying), the concentration of the texture improver (0.0 - 1.0 %), and the yogurt powder concentration (8.0 - 15.0 %). The above-mentioned rheological parameters, color, and viability of the lactic acid bacteria from each reconstituted yogurt powder were considered as the dependent variables. Optimization sought to match the parameters of reconstituted yogurt powder that approximated the conditions of fresh yogurt. Results: The independent variables in their lineal expression and some interactions between them had statistically significant differences (p < 0.05). At a concentration of 10.59 % with 0.03 % xanthan gum, the reconstitution of freeze-dried yogurt powder was the optimized condition (p < 0.05) and obtained the rheological, color, and microbiological parameters closest to fresh yogurt. Conclusions: The drying of the yogurt by freeze-drying mixed with xanthan gum as a texture improver allowed to obtain a reconstituted yogurt with properties close to the fresh product for direct consumption
Antecedentes: Una de las estrategias de conservación más utilizadas y efectivas en los alimentos es el secado. Sin embargo, existen problemas en las propiedades reológicas, el color y la viabilidad de bacterias ácido lácticas en el yogur una vez reconstituido al aplicar tales estrategias de conservación. Objetivos: Determinar la concentración del tipo de mejorador de textura y secado que minimiza el efecto negativo sobre las propiedades reológicas, de color y microbiológicas de un yogur en polvo reconstituido. Métodos: Para determinar el mejorador de textura que aumente las propiedades reológicas del yogur en polvo reconstituido, se aplicó un diseño experimental de tipo de mezcla donde se evaluaron tres mejoradores de textura; carboximetilcelulosa (CMC) (fracción de masa 0 -1), pectina (fracción de masa 0 -1) y goma xantan (fracción de masa 0 -1); los parámetros reológicos: índice de consistencia (K), comportamiento de flujo (n), viscosidad a 100s-1 (η), módulos de almacenamiento (G') y pérdida (G''), y ángulo de desfase (δ) de cada una de las reconstituciones fueron considerados como variables dependientes. En segundo lugar, se utilizó un diseño central compuesto (centrado a las caras) para evaluar el efecto del tipo de secado (convección, secado por aspersión y liofilización), la concentración del mejorador de textura (0.0 - 1.0 %) y concentración del yogur en polvo (8.0 - 15.0 %). Como variables dependientes se consideraron los parámetros reológicos mencionados anteriormente, el color y la viabilidad de las bacterias ácido lácticas de cada yogur en polvo reconstituido. La optimización buscó igualar los parámetros del yogur en polvo reconstituido que se aproximaran a las condiciones del yogur fresco. Resultados: Las variables independientes en su expresión lineal y algunas interacciones entre ellas tuvieron diferencias estadísticamente significativas (p < 0.05). La reconstitución de yogur liofilizado en polvo a una concentración de 10.59 % con 0.03 % de goma xantan, fueron las condiciones optimizadas (p < 0.05) que obtuvieron los parámetros reológicos, de color y microbiológicos más cercanos al yogur fresco. Conclusión: El secado del yogur por liofilización mezclado con goma xantan como mejorador de la textura, permitió obtener un yogur reconstituido con propiedades cercanas al producto fresco para consumo directo
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Humanos , Liofilização , Reologia , Iogurte , Nebulizadores e Vaporizadores , Conservação de AlimentosRESUMO
The freeze-drying technique, characterized by low-temperature processing, is especially suitable for sensitive volatile oils with thermal instability. However, there are few studies focusing on the retention of volatile oils in the processing of freeze-dried preparations. This study evaluated the effects of different addition methods(adsorption, emulsification, solid dispersion, and inclusion) on the retention rate of the main components in peppermint oil, aiming to explore the application feasibility of freeze-dried preparations of volatile oils. Firstly, the addition method was determined based on the retention rates of menthol in four freeze-dried preparations. Secondly, an orthogonal test was designed to optimize the preparation process based on the characteristics of the preferred addition method. The results showed that the most suitable preparation form of peppermint oil was inclusion with beta-cyclodextrin(β-CD), and the retention rate of menthol in freeze-drying was 86.36%. According to the two-step preparation process of inclusion and freeze-drying, we introduced the product of inclusion rate and retention rate, i.e., comprehensive retention rate, to determine the optimum processing parameters. The results showed that β-CD/oil ratio of 7∶1, inclusion temperature of 40 ℃, and inclusion time of 2 h were the optimum processing parameters. The product prepared with these parameter had the comprehensive retention rate of 68.41%, retention rate of 92.53%, and inclusion rate of 73.93%. The inclusion compound was white powder with significantly increased solubility. The pre-paration process based on cyclodextrin inclusion in this study is stable and reliable and provides a new idea for ensuring the efficacy and stability of volatile components in freeze-dried preparations.
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Ciclodextrinas , Liofilização , Mentha piperita , Óleos Voláteis , Óleos de Plantas , Solubilidade , TecnologiaRESUMO
OBJECTIVE：To establish the method for the content det ermination of 4 components in Forsythia suspensa flowers by drying in shade ，vacuum freeze-drying ，oven（30，50，70 ℃）and sun ，so as to evaluate the effects of different drying methods on the main components of F. suspensa flowers and screen the optimal drying method. METHODS ：UPLC method was adopted. The determination was performed on Waters ACQUITY UPLC BEH C 18 column with mobile phase consisted of acetonitrile- 0.1％ phosphoric acid aqueous solution （gradient elution ）at the flow rate of 0.3 mL/min. The detection wavelength was set at 230 nm， and column was 35 ℃. The sample size was 1 μL. Euclidean closeness（C）i of different drying methods was calculated by TOPSIS comprehensive analysis method ，and the optimal drying method was defined. RESULTS ：The linear range of forsythiaside A ， rutin，forsythin，（+）-pinoresinol-4-O-β-D-glucopyranoside were 0.007 5-0.037 7，0.027 4-0.137 2，0.001 9-0.009 5，0.005 6-0.028 8 µg（all r＞0.999）. RSDs of precision ，stability（32 h）and reproducibility tests were all lower than 2％. The recoveries were 97.27％-102.53％，100.53％-104.11％，98.45％-104.02％，98.66％-104.82％，respectively；and all RSDs ＜3％（n＝3）. The contents were 1.645 8-4.987 9，11.730 2-20.978 0，0.875 5-2.005 0，2.366 0-5.535 7 mg/g. The content of forsythiaside A was the highest after drying at 30 ℃，rutin and （+）-pinoresinol-4- O-β-D-glucopyranoside were the highest after vacuum freeze-drying，forsythiaside was the highest after drying at 50 ℃ . Results of TOPSIS analysis showed that Ci of F. suspensa flowers by drying in shade ，vacuum freeze-drying ，oven（30，50，70 ℃）and sun were 0.079 9，0.553 5，0.495 4， 0.503 8，0.157 9，0.217 2，respectively；the order of Ci was vacuum freeze-drying ＞ 50 ℃ oven drying ＞ 30 ℃ oven drying＞sun drying ＞70 ℃ oven drying ＞ shade drying. CONCLUSIONS：Established method is simple ，reproducible and can be used for the content determination of 4 components in F. suspensa flowers. The samples are preferably dried by vacuum freeze-drying，followed by 50 ℃ oven drying ，30 ℃ oven drying ， and then dried in the sun and oven at 70 ℃ and finally in the shade.
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ObjectiveTo analyze a case of death after inoculation of a freeze-dried rabies vaccine for human use so as to provide reference for the vaccination of the rabies vaccine and the process of investigation and diagnosis involving adverse events following immunization （AEFI） in the future. MethodsData on vaccination， clinical symptoms， treatments， investigation and diagnosis were collected and analyzed. ResultsRabies post-exposure prophylaxis and vaccination were in line with the protocols. On the 3rd day after the inoculation of the rabies vaccine， the patient developed fever， weakness， headache， dizziness， diarrhea and other symptoms. The white blood cell count and neutrophil count increased progressively. At about 17：00 on the same day， the patient suffered a sudden cardiac arrest and died clinically. Autopsy was not carried out. ConclusionThe cause of sepsis /septic shock of the patient is unknown. It is necessary to formulate detailed rabies immunization procedures as well as norms and expert consensus in the field of investigation and diagnosis of AEFI.
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ObjectiveTo analyze a case of death after inoculation of a freeze-dried rabies vaccine for human use so as to provide reference for the vaccination of the rabies vaccine and the process of investigation and diagnosis involving adverse events following immunization （AEFI） in the future. MethodsData on vaccination， clinical symptoms， treatments， investigation and diagnosis were collected and analyzed. ResultsRabies post-exposure prophylaxis and vaccination were in line with the protocols. On the 3rd day after the inoculation of the rabies vaccine， the patient developed fever， weakness， headache， dizziness， diarrhea and other symptoms. The white blood cell count and neutrophil count increased progressively. At about 17：00 on the same day， the patient suffered a sudden cardiac arrest and died clinically. Autopsy was not carried out. ConclusionThe cause of sepsis /septic shock of the patient is unknown. It is necessary to formulate detailed rabies immunization procedures as well as norms and expert consensus in the field of investigation and diagnosis of AEFI.
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italic>Tert-butanol is an organic solvent, widely used in the medical field and chemical industry. It could be characterized by high crystallization temperature and vapor pressure. It could be easily sublimed and removed during the freeze-drying process. This review mainly describes the use of tert-butanol in the lyophilized formulations of poorly soluble drugs, the lyophilization solvent of porous structure productions, and as an ice crystal growth guider. In addition, the application of tert-butanol in nano drugs and aerogels has also been reviewed, as well as the current research progress in its quality and safety.
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Background: Freeze-drying is known as one of the best methods to preserve bacterial strains. Protectant is the key factor affecting the survival rate of freeze-dried strains. In addition, salinity, bacterial suspension concentration, drying time, and other factors can also affect the survival rate of strains to varying degrees. At present, there are relatively few studies on freeze-drying preservation of marine bacteria. In the present study, we performed the freeze-drying protectant screening and optimized the preservation conditions for Pseudoalteromonas nigrifaciens, which is widely distributed in marine environment. The protective effects of the screened protectants were verified by 18 other marine bacterial strains. Results: The results indicated that the combination of 5.0% (w/v) lactose, 5.0% (w/v) mannitol, 5.0% (w/v) trehalose, 10.0% (w/v) skim milk powder, 0.5% (w/v) ascorbic acid and 0.5% (w/v) gelatin was the best choice for the preservation of P. nigrifaciens. The suggested salinity and concentration of initial cell suspension were 10 g/L NaCl and 1.0 × 109 CFU/mL, respectively. Furthermore, stationary-phase cells were the best choice for the freeze-drying process. The highest survival rate of P. nigrifaciens reached 52.8% when using 510% (w/v) skim milk as rehydration medium. Moreover, the other 18 marine strains belonging to Pseudoalteromonas, Vibrio, Photobacterium, Planomicrobium, Edwardsiella, Enterococcus, Bacillus, and Saccharomyces were freezedried under the abovementioned conditions. Their survival rates were 2.395.1%. Conclusion: Collectively, our results supported that the protectant mixture and parameters were beneficial for lyophilization of marine bacteria