Application prospect of reaction engineering approach in studying drying behavior of single droplet during spray drying of traditional Chinese medicine / 中国中药杂志

Spray drying technology is one of the most commonly used unit operations in the production of traditional Chinese medicine(TCM) preparations, offering advantages such as short drying time and uniform product quality. However, due to the properties of TCM extracts, such as high viscosity, strong hygroscopicity, and poor flowability, there is limited scope to solve the problems of wall adhesion and clumping in spray drying from the macroscopic perspective of pharmaceutical production. Therefore, it has become a trend to study and optimize the spray drying process from the microscopic point of view by investigating single droplet evaporation behavior. Based on the reaction engineering approach(REA), the single droplet drying system, as a novel method for studying droplets, collects parameter data on individual TCM droplets during the drying process and uses the REA to process the data and establish predictive models. This approach is crucial for understanding the mechanism of TCM spray drying. This paper summarized and analyzed the cha-racteristics of various single droplet systems, the application of REA in single droplet drying systems, and its significance in optimizing the process, predicting drying states, and shortening the development cycle in the field of TCM spray drying, and looked ahead to the prospects of this method, including the introduction of new parameters and imaging techniques, aiming to provide a reference for further research in the field of TCM spray drying.

Physiochemical property variation in traditional Chinese medicine decoction before or after precipitation in alcohol and its relationship with wall stickiness in spray drying / 中国中药杂志

To explore the relationship between the variations of the physiochemical properties of traditional Chinese medicine(TCM) decoction before or after precipitation in alcohol and the wall stickiness in spray drying. In this study, widely used TCMs in clinic were selected to determine the physiochemical properties of TCM decoction before or after precipitation in alcohol separately.Afterwards, the principle component analysis(PCA),Hierarchical cluster analysis(HCA),and orthogonal partial least squares-discriminate analysis(OPLS-DA) were used to evaluate the relationship between the variations of those liquid before or after precipitation in alcohol and hot-melt stickiness in spray drying.Three types of statistical analysis methods all indicated that ethanol precipitation affected physiochemical properties of TCM decoction, and the variations of physical properties showed significant association with hot-melt stickiness in spray drying.The results of PCA-X and HCA suggested that the dynamic surface tension(DST) was impacted most by the alcohol deposition treatment,at the same time,the other 5 physiochemical properties were also affected.OPLS-DA verified that PCA-X and HCA results, and revealed that DST,equilibrium surface tension(EST) and pH were significantly affected by alcohol deposition treatment,and the order of the affecting factors from high to low was DST,EST and pH.Therefore,the downward trend of DST and pH were the important factors that directly affected the hot-melt stickiness of TCM after precipitation in alcohol,which would be probably caused by losing macromolecules alcoholic insoluble components and increasing relative proportions of organic acid and small molecule sugar.

Spray drying process of extract of Wenjing Zhitong Prescription based on mixture design experiment / 中国中药杂志

To improve the spray drying effect of extract of Wenjing Zhitong Prescription, this study takes the yield, hygroscopic property and the fluidity of dry powder as indexes to screen out auxiliary materials, and the proportion of the auxiliary materials was optimized based on the mixing design experiment; based on that, HPLC method was established for the determination of glycyrrhizin and 6-gingerol in spray powder, the yield of spray powder and the retention rate of the two index components were taken as indexes to further optimize the spray drying parameters. The finally selected auxiliary materials were light magnesium oxide, maltodextrin and silica, and regression equations of dry powder yield, moisture absorption rate, angle of rest with proportion of auxiliary materials were established, and the optimized proportion of auxiliary materials was dry paste-light magnesium oxide-maltodextrin-silica=0.5∶0.305∶0.145∶0.05; according to the optimized drying process parameters of Wenjing Zhitong Prescription, initial temperature was 60 ℃, air inlet temperature was 130 ℃, air flow rate was 35 m~3·h~(-1), atomizing pressure was 40 mm, and liquid inlet speed was 4.5 mL·min~(-1). Under these conditions, the dry powder yield was 90.28%, the retention rate of glycyrrhizin was 74.51%, and the retention rate of 6-gingerol was 72.10%. In this study, optimized auxiliary materials can improve the yield of spray drying and the property of spray powder, and the optimized processing conditions were good for retaining the unstable gingerol components, which can lay a foundation for the further preparation research of meridian warming and pain relieving prescriptions, and provide reference for extract of other traditional Chinese medicine extracts that are difficult to spray drying.

Progress in tear microdesiccate analysis by combining various transmitted-light microscope techniques

BACKGROUND: Tear desiccation on a glass surface followed by transmitted-light microscopy has served as diagnostic test for dry eye. Four distinctive morphological domains (zones I, II, III and transition band) have been recently recognized in tear microdesiccates. Physicochemical dissimilarities among those domains hamper comprehensive microscopic examination of tear microdesiccates. Optimal observation conditions of entire tear microdesiccates are now investigated. One-µl aliquots of tear collected from individual healthy eyes were dried at ambient conditions on microscope slides. Tear microdesiccates were examined by combining low-magnification objective lenses with transmitted-light microscopy (brightfield, phase contrasts Ph1,2,3 and darkfield. RESULTS: Fern-like structures (zones II and III) were visible with all illumination methods excepting brightfield. Zone I was the microdesiccate domain displaying the most noticeable illumination-dependent variations, namely transparent band delimited by an outer rim (Ph1, Ph2), homogeneous compactly built structure (brightfield) or invisible domain (darkfield, Ph3). Intermediate positions of the condenser (BF/Ph1, Ph1/Ph2) showed a structured roughly cylindrical zone I. The transition band also varied from invisibility (brightfield) to a well-defined domain comprising interwoven filamentous elements (phase contrasts, darkfield. CONCLUSIONS: Imaging of entire tear microdesiccates by transmitted-light microscopy depends upon illumination. A more comprehensive description of tear microdesiccates can be achieved by combining illumination methods.

Shock séptico en unidad de cuidados intensivos: Enfoque actual en el tratamiento / Septic shock in intensive care units: Current focus on treatment

Los pilares terapéuticos del niño con shock séptico se mantienen en el tiempo, sin embargo, se han incorporado nuevos conceptos, siendo importante que el pediatra y el intensivista tengan conocimiento a cabalidad de ellos. La reanimación con fluidos es una intervención fundamental, no obstante, aún no se ha establecido un tipo de fluido ideal, presentando cada uno limitaciones específicas, no existiendo evidencia sobre la superioridad de un tipo de fluido. Si a pesar de una adecuada resucitación con fluidos persiste el shock, el inicio de inótropos y/o vasopresores está indicado. En caso de refractariedad al uso de vasopresores, nuevos fármacos vasoactivos pueden ser empleados y el uso de hidrocortisona debe considerarse en niños con sospecha de insuficiencia suprarrenal. Existe controversia respecto a la transfusión de glóbulos rojos o el nivel óptimo de glucemia, no existiendo consenso en el valor umbral para el uso de estos hemocomponentes o el inicio de insulina, respectivamente. Asimismo, la utilización de la hemofiltración de alto volumen (HFAV)aún permanece controversial, requiriendo mayores estudios para su recomendación en forma rutinaria en el curso de un shock séptico refractario. El soporte nutricional es primordial, ya que la desnutrición es una grave complicación que debe ser prevenida y tratada adecuadamente. El objetivo de la presente revisión es entregar una actualización en los más recientes avances en tratamiento del shock séptico en la población pediátrica.

Essential therapeutic principles in children with septic shock persist over time, although some new concepts have been recently incorporated, and fully awareness of pediatricians and intensivists is essential. Fluid resuscitation is a fundamental intervention, but the kind of ideal fluid has not been established yet, as each of these interventions has specific limitations and there is no evidence supportive of the superiority of one type of fluid. Should septic shock persists despite adequate fluid resuscitation, the use of inotropic medication and/or vasopressors is indicated. New vasoactive drugs can be used in refractory septic shock caused by vasopressors, and the use of hydrocortisone should be considered in children with suspected adrenal insufficiency, as it reduces the need for vasopressors. The indications for red blood cells transfusion or the optimal level of glycemia are still controversial, with no consensus on the threshold value for the use of these blood products or the initiation of insulin administration, respectively. Likewise, the use of high-volume hemofiltration is a controversial issue and further study is needed on the routine recommendation in the course of septic shock. Nutritional support is crucial, as malnutrition is a serious complication that should be properly prevented and treated. The aim of this paper is to provide update on the most recent advances as concerns the treatment of septic shock in the pediatric population.

Loss of desiccation tolerance in Copaifera langsdorffii Desf. seeds during germination / Perda da tolerância à dessecação em sementes de Copaifera langsdorffii durante a germinação

This study evaluated the loss of desiccation tolerance in C. langsdorffii seeds during the germination process. Seeds were imbibed for 24, 48, 72, 96, 120 and 144 hours and dried to the initial moisture content, kept in this state for 3 days after which they were submitted to pre-humidification and rehydration. Ultraestructural evaluations were done aiming to observe the cell damage caused by the dry process. Desiccation tolerance was evaluated in terms of the percentage of normal seedlings. Seeds not submitted to the drying process presented 61% of normal seedlings, and after 24 hours of imbibition, followed by drying, the seeds presented the same percentage of survival. However, after 48 hours of imbibition, seeds started to lose the desiccation tolerance. There was twenty six percent of normal seedlings formed from seeds imbibed for 96 hours and later dried and rehydrated. Only 5% of seeds imbibed for 144 hours, dried and rehydrated formed normal seedlings. At 144 hours of imbibition followed the dry process, there was damage into the cell structure, indicating that the seeds were unable to keep the cell structure during the drying process. Copaifera langsdorffii seeds loses the desiccation tolerance at the start of Phase 2 of imbibition.

Este estudo avaliou a perda da tolerância à dessecação em sementes de C. langsdorffii durante o processo germinativo. Sementes foram embebidas por 24, 48, 72, 96, 120 e 144 horas e depois secas até a umidade inicial, sendo mantidas neste estado durante 3 dias, quando então foram submetidas a pré-umidificação e reidratação. Avaliações ultraestruturais foram realizadas objetivando observar danos nas células causados pelo processo de secagem. A tolerância à dessecação foi avaliada pelo percentual de plântulas normais. Sementes não submetidas ao processo de secagem apresentaram 61% de plântulas normais, sendo que após 24 horas de embebição seguida de secagem, houve o mesmo percentual de sobrevivência. Contudo, após 48 horas de embebição, as sementes começaram a perder a tolerância à dessecação. Vinte e seis por cento de sementes formaram plântulas normais após embeberem por 96 horas e secas. Apenas 5% de sementes embebidas por 144 horas e secas formaram plântulas normais. Após 144 horas de embebição, seguida de secagem, verificou-se danos na estrutura celular, o que indica que as sementes não são capazes de manter a estrutura celular durante o processo de secagem. Verificou-se no presente estudo que sementes de C. langsdorffii perdem a tolerância à dessecação no inicio da fase 2 da embebição.

Tolerancia a la desecación de semillas de Prosopis ferox y Pterogyne nitens (Fabaceae)

Desiccation tolerance in seeds of Prosopis ferox and Pterogyne nitens (Fabaceae). The high number of endemisms and species diversity together with the accelerated biodiversity loss by deforestation, especially in North Western Argentina, points out the need to work on species conservation combining ex situ and in situ strategies. The aim of this work was to study the desiccation tolerance in seeds of P. ferox and P. nitens for long term ex situ conservation at the Germplasm Bank of Native Species (BGEN) of the National University of Salta (Argentina). The fruits were collected from ten individuals in P. ferox at the National Park Los Cardones and from two sites (Orán and Rivadavia) for P. nitens. Desiccation tolerance was assessed following previous established methodologies. The moisture content (MC) of the seeds was determined by keeping them in oven at 103°C and weighting the samples at different intervals till constant weight. Germination essays were carried out with two treatments (control and scarification), with different seed MC (fresh, 10-12%, 3-5%) and in desiccated seeds (3-5% MC) stored six months at -20ºC. The MC in P. ferox seeds was 14.2% and 10% in P. nitens, for both populations studied. Percentage germination in P. ferox was higher in the scarification treatments (<82%). The difference between treatments increased with the reduction in MC and the storage for six months at -20°C. Fresh seeds of P. nitens do not need scarification treatment, but it is required with the reduction in MC and storage. Mean germination percentage of desiccated seeds stored six months at -20°C was similar in both populations and greater than 82%.We concluded that both species are probably orthodox because seeds tolerated desiccation to 3-5% and storage for six months at -20°C.

La elevada diversidad de especies y endemismos, conjuntamente con la acelerada pérdida de biodiversidad por deforestaciones, destaca la importancia de emprender acciones combinadas de conservación in situ y ex situ. El objetivo de este trabajo fue estudiar la tolerancia a la desecación de las semillas de Prosopis ferox y Pterogyne nitens, para su conservación ex situ a largo plazo en el BGEN. El contenido de humedad (CH) se determinó colocando las semillas de cada población en estufa a 103°C y pesando las muestras a intervalos regulares hasta peso constante. Se realizaron ensayos de germinación en distintos CH: semillas frescas, 10-12%, 3-5%, y en semillas mantenidas seis meses a -20ºC y a 3-5% de CH. El CH de las semillas frescas de P. ferox fue de 14.2% y el de P. nitens de 10% para las dos poblaciones estudiadas. Las semillas de P. ferox llegaron a peso constante a las 17hr y las de P. nitens a las 3hr de secado. La germinación de las semillas de P. ferox fue mayor en los tratamientos con escarificación y la diferencia aumento con la reducción del CH y el almacenamiento. Las semillas de P. nitens con el CH reducido, requieren escarificación. Se concluye que las semillas de ambas especies son probablemente ortodoxas ya que la germinación superó el 80% en las semillas desecadas al 3-5% CH y almacenadas durante seis meses a -20°C.

Microdesiccates produced from normal human tears display four distinctive morphological components

Desiccation of human tears on glass surfaces results in fern-like crystalloids. This phenomenon has been associated with tear normality (Tear Ferning Test, TFT) and is used as a diagnostic aid to evaluate patients with Dry-Eye disease. However, TFT is focused on the assessment of only a minor fraction of desiccated tear samples and considers only the relative abundance and density of fern-like crystalloids. The aim of this study was to characterize morphologically entire desiccated micro volumes of tears from healthy donors. Tear samples were collected from 23 healthy young adult volunteers. Tear aliquots (1-3 μL) were allowed to dry on glass surfaces under ambient conditions of temperature (15-25°C) and relative humidity (40-45%). Dry samples were analyzed by dark-field microscopy. Morphometric data were acquired with Image J software. Tear volume was positively correlated with both area and time of desiccation. Morphological features of multiple microdesiccates produced from a single subject displayed striking similarities whereas tear microdesiccates from different healthy subjects displayed consistent differences but shared a common general design. This design may be mostly represented by the occurrence of four distinctive zones, named as zones I, II, III and Transition band. The main features of these zones are described.

Increasing the rate of drying reduces metabolic imbalance, lipid peroxidation and critical water content in radicles of garden pea (Pisum sativum L.)

Orthodox seeds become desiccation-sensitive as they undergo germination. As a result, germinating seeds serve as a model to study desiccation sensitivity in plant tissues. The effects of the rate of drying on the viability, respiratory metabolism and free radical processes were thus studied during dehydration and wet storage of radicles of Pisum sativum. For both drying regimes desiccation could be described by exponential and inverse modified functions. Viability, as assessed by germination capacity and tetrazolium staining, remained at 100% during rapid (< 24 h) desiccation. However, it declined sharply at c. 0.26 g g¹ dm following slow (c. 5 days) drying. Increasing the rate of dehydration thus lowered the critical water content for survival. Rapid desiccation was also associated with higher activities and levels of malate dehydrogenase and the oxidized form of nicotinamide adenine dinucleotide. It was also accompanied by lower hydroperoxide levels and membrane damage. In addition, the activitiy of glutathione reductase was greater during rapid drying. Ageing may have contributed to increased damage during slow dehydration, since viability declined even in wet storage after two weeks. The results presented are consistent with rapid desiccation reducing the accumulation of damage resulting from desiccation-induced aqueous-based deleterious reactions. In addition, they show that radicles are a useful model to study desiccation sensitivity in plant tissues.

Efecto del procesamiento sobre la capacidad antioxidante de la ciruela criolla (Prunus domestica)

Las frutas son consideradas fuentes de compuestos antioxidantes, cuyas propiedades pudieran desmejorar debido al procesamiento. El objetivo de esta investigación fue determinar el efecto del escaldado y la deshidratación osmótica sobre el contenido de polifenoles totales, taninos y la capacidad antioxidante de la ciruela criolla (Prunus domestica) en sus variedades amarilla y roja. La concentración de los polifenoles totales se determinó mediante el método Folin-Ciocalteu, los taninos por el método de la vanilina y la capacidad antioxidante por la eficiencia antirradical (EA) y el método de poder reductor férrico (FRP). El contenido de polifenoles totales y los taninos fueron mayores en la ciruela roja que en la amarilla. En las dos variedades, el mayor contenido de polifenoles se encontró en la pulpa, mientras que los taninos se encontraron en mayor proporción en las cáscaras. La ciruela roja presentó mayor capacidad antioxidante, siendo la EA baja y de cinética lenta para las dos variedades. Se observó una correlación lineal entre los polifenoles y los taninos con la eficiencia antirradical, sin embargo, con el poder reductor no hubo correlación. El escaldado incrementó el contenido de polifenoles, mientras que los taninos y la EA disminuyeron, el poder reductor no se vio afectado por los tratamientos. Para la deshidratación osmótica se obtuvo una disminución significativa de los taninos y la eficiencia antirradical, mientras que los polifenoles y el poder reductor no se vieron afectados por el procesamiento. Se recomienda el escaldado como alternativa de consumo y conservación en la ciruela criolla.

Effect of processing on the antioxidant capacity of the plum (Prunus domestica). Fruits are considered sources of antioxidant compounds whose properties could impair due to processing. The objective of this work was to determine the effect of blanching and osmotic dehydration on the total polyphenols content, tannins and antioxidant capacity of plums (Prunus domestica) in yellow and red varieties. The total phenolic content in plums was determined according to the Folin-Ciocalteu assay and tannins were determined by vanillin assay. The antiradical efficiency (AE) and ferric reducing power (FRP) were used to estimate the total antioxidant capacity. The content of total polyphenols and tannins were higher in the red plum. The content of polyphenols in the pulp was higher that the peel while for tannins the opposite was observed in both varieties. The red plum had higher antioxidant capacity. The AE was low and slow kinetics for the two varieties. There was a linear correlation between polyphenols and tannins with antiradical efficiency; however, there was no correlation with the reducing power. The total polyphenols content was increased with blanching, while the tannins and the AE decreased, ferric reducing power is unaffected. For osmotic dehydration, the tannins and the AE were decreased, while the total polyphenols content and ferric reducing power are unaffected.It is recommended the blanched as an alternative to consumption and conservation in the plum.

Plexiform neurofibroma of the upper limb / Neurofibroma plexiforme de membro superior

The authors present an unusual case of plexiform neurofibroma affecting the upper limb in a patient diagnosed with type 1 neurofibromatosis. Tumor resection was performed on the median nerve. The patient showed maintenance of limb function and remission of symptoms of pain after four years of follow-up.

Os autores apresentam um caso incomum de neurofibroma plexiforme acometendo o membro superior, com diagnóstico de neurofibromatose do tipo 1. Realizou-se a ressecção do tumor no nervo mediano. A paciente evoluiu com manutenção da função do membro e remissão dos sintomas de dor após seguimento de quatro anos.

Impact of solar dehydration on composition and antioxidant properties of acai (Euterpe oleracea Mart.)

Commercial products derived from the acai fruit (Euterpe oleracea Mart.) are available in Brazil, but in Venezuela, it is only known by ethnic indigenous groups of the Amazon. In this study, acai flour was made by solar dehydration and the effect of processing on the composition, microbiological quality, and antioxidant properties of such flour were evaluated. The fruit was purchased in Puerto Ayacucho, Venezuela, and a portion was manually pulped. Microbiological quality, proximal composition, minerals, polyphenols, tannins, anthocyanins, and antioxidant capacity were evaluated. The remaining portion of fruit was blanched in a solution of ascorbic acid and citric acid at 98ºC for 1min in the same manner, manually pulped, dried by solar dehydration and the acai flour was also analysed. From the composition of the acai flour, its high content of fat (22.9%), protein (13.7%), dietary fibre (20.5%), total polyphenols (1.60 g/kg) and antioxidant capacity (79.97%) stood out. The blanching of the fruit and the solar dehydrating of the acai pulp did not modify the composition, but they improved its microbiological quality and reduced phenolic compounds and antioxidant capacity. The flour obtained is stable and innocuous and could be used to diversify the diet of the indigenous people of the Amazon region.

Los productos comerciales derivados del fruto del acai (Euterpe oleracea Mart) están disponibles en Brasil, no así en Venezuela donde sólo los grupos indígenas del Amazonas lo conocen y consumen. En este estudio se elaboró una harina de acai mediante deshidratación solar y se evaluó el efecto del procesamiento en la composición, calidad microbiológica y propiedades antioxidantes de dicha harina. Los frutos fueron adquiridos en Puerto Ayacucho, Venezuela y una porción de ellos se despulpó manualmente y se le determinó calidad microbiológica, composición proximal, contenido de minerales, contenido de polifenoles, taninos, antocianinas y la capacidad antioxidante. La otra porción del fruto se escaldó en una solución de ácido ascórbico y ácido cítrico a 98ºC por 1min, se despulpó manualmente y se eliminó su humedad por deshidratación solar; a la harina de acai obtenida se le hicieron los mismos análisis que a la pulpa. De la composición del acai resaltó su alto contenido de grasa (22.9%), proteína (13.7%), fibra dietética (20.5%), polifenoles totales (1.60 g/kg-1) y su capacidad antioxidante (79.97%). El lavado y escaldado de los frutos y la posterior deshidratación solar de la pulpa del acai no modificó significativamente su composición, pero si mejoró la calidad microbiológica y redujo los compuestos fenólicos y la capacidad antioxidante. La harina obtenida es estable e inocua y se podría utilizar para diversificar la dieta de los indígenas de la región del Amazonas.

Physicochemical characteristics and sensory profile of honey samples from stingless bees (Apidae: Meliponinae) submitted to a dehumidification process

This study was conducted to evaluate the effect of a dehumidification process on the physicochemical and sensory characteristics of stingless-bee honey. Melipona scutellaris and M. quadrifasciata honey samples were submitted to a dehumidification process and to physicochemical (reducing sugars, apparent sucrose, moisture, diastatic activity, hydroxymethylfurfural, ash, pH, acidity, and electric conductivity) and sensory evaluations (fluidity, color, aroma, crystallization,flavor,and acceptability). The results indicated that the dehumidification process does not interfere with honey quality and acceptability.

Este estudo foi conduzido com o objetivo de avaliar o efeito do processo de desumidificação sobre as características físico-químicas e sensoriais do mel das abelhas sem ferrão. Amostras de méis de Melipona scutellaris e M. quadrifasciata foram submetidas ao processo de desumidificação, passando em seguida por avaliações físico-químicas (açúcares redutores, sacarose aparente, umidade, atividade diastásica, hidroximetilfurfural, cinzas, pH, acidez e condutividade elétrica) e sensoriais (fluidez, cor, aroma, cristalização, sabor e aceitabilidade). Os resultados indicaram que o processo de desumidificação não interfere na qualidade e aceitabilidade do mel.

Heat radiation vs air drying to remove interfacial water from self-etch adhesives.

The clinician's quest for time-saving and technique-insensitive technology has led to the development of simplified self-etch adhesives that are predominantly water or solvent based. Several studies have shown that conventional air-drying procedures are incapable of eliminating all the residual water in the adhesive and that it may even cause collapse of the underlying collagen matrix. We hypothesized that heat from a light source may be effective in removing water from these adhesives. The aim of this study was, therefore, to evaluate the effectiveness of heat vs conventional air drying in eliminating water droplets from self-etch adhesive. A self-etch adhesive was applied to bur-cut dentin surfaces, which were then allotted to one of two treatment procedures for eliminating residual water from the adhesive: conventional air drying or the experimental heat application. Specimens were then prepared and analyzed using SEM. Specimens in the experimental group showed no evidence of water treeing within the adhesive layer. Thus, it was concluded that heat radiation was an effective method to remove residual water from simplified adhesives.

Aceleración de la deshidratación osmótica de frambuesas (Rubus idaeus) por medio de calentamiento óhmico / Acceleration of osmotic dehydration process through ohmic heating of foods: raspberries (Rubus idaeus)

Frambuesas (Rubus idaeus) se deshidrataron osmóticamente a través de un tratamiento convencional bajo el supuesto de solución homogénea, utilizando como medio una solución de glucosa al 62% a una temperatura de 50ºC. También se deshidrataron osmóticamente por medio de calentamiento óhmico, utilizando como medio una solución de glucosa al 57%, con voltaje variable (para mantener una temperatura entre 40-50ºC) y unaintensidad del campo eléctrico <100 V/cm. Al comparar los resultados se observa una evidente disminución en el tiempo de proceso al utilizar el calentamiento óhmico. En algunos casos, ésta reducción alcanzó hasta un 50%. Esto se explica por el efecto adicional al daño térmico que se genera en un proceso óhmico, denominado electroporación.

Acceleration of osmotic dehydration process through ohmic heating of foods: raspberries (Rubus idaeus). Raspberries (Rubus idaeus) were osmotically dehydrated by applying a conventional method under the supposition of a homogeneous solution, all in a 62% glucose solution at 50ºC. Raspberries (Rubus idaeus) were also osmotically dehydrated by using ohmic heating in a 57% glucose solution at a variable voltage (to maintain temperaturebetween 40 and 50ºC) and an electric field intensity <100 V/cm. When comparing the results from both experiments it was evident that processing time is reduced when ohmic heating technique wasused. In some cases this reduction reached even 50%. This is explained by the additional effect to the thermal damage that is generated in an ohmic process, denominated electroporation.

Desiccation resistance in Arcobacter butzleri

The desiccation resistance of A. butzleri was studied. Two, 3 and 4 of the strains did not resist desiccation for more than 2, 12 and 36 h, respectively. Two strains resisted desiccation for>=48 h. A butzleri seems to be more resistant to desiccation than the classical enteropathogenic Campylobacter species.

Effects of the desiccation on Biomphalaria tenagophila (Orbigny, 1835) (Mollusca) infected by Schistosoma mansoni Sambon, 1907

Specimens of Biomphalaria tenagophila exposed to miracidia of Schistosoma mansoni were submitted to different desiccation periods as follows: group I: 24 h after exposure, desiccated for 28 days; group II: after cercariae elimination, desiccated for 7 days; group III: 21 days after exposure, desiccated for 7 days; group IV: 14 days after exposure, desiccated for 14 days; group V: 7 days after exposure, desiccated for 21 days. From the obtained data it was verified that desiccation was not capable of interrupting the development of larvae of S. mansoni in mollusks. A delay in the development of S. mansoni larvae in groups I, III, IV and V was observed. A pause was verified in the development of S. mansoni larvae in groups II, III, IV and V. Some larvae, in groups I, III, IV and V, did not suffer as a result of desiccation and continued their development. Larvae in the cercariae stage were shown to be more sensitive to desiccation. It was possible to obtain clearing of mollusks infected by sporocysts II and cercariae using a period of 7 days of desiccation

The cryodehydration technique applied to cavitary and parenchymatous viscera

Among the anatomical techniques developed to obtain dry material, the cryodehydration is an important procedure, since it is very helpful in pratical classes. By alternating freezing and thawing (FT) sctions, the cell destruction simplifies fluids release, obtaining material with some advantages such as: form keeping, loss of weight, no need for fixer (no mucosal irritation) and a low cost technique.

Circumoval precipitin (COP) test using air-dried eggs of Schistosoma japonicum and S. mansoni.

In an attempt to establish a simplified circumoval precipitin (COP) test for the diagnostic purpose of schistosomiasis, air-dried eggs of both Schistosoma japonicum and S. mansoni were tested as antigens for this assay. Twenty-six sera from mice infected with S. japonicum showed positive COP reactions as assessed by air-dried eggs. Among 36 serum samples from patients with schistosomiasis japonica, five exhibited false negative reaction when assessed with air-dried eggs and showed a minimum level of COP reaction when assessed with lyophilized eggs. Similarly, all of 30 serum samples from jirds (Meriones unguiculatus) infected with S. mansoni gave positive COP reaction when assessed using air-dried egg. Diagnostic sensitivity of air-dried egg-system was comparable to those of fresh egg-or lyophilized egg-systems. A simple COP technique employing air-dried eggs, instead of lyophilized or fresh ones, would be thus useful for the serodiagnosis of schistosomiasis in local endemic areas, where sophisticated laboratory facilities are not available.