Rate Of Rehydration Research Articles

Physiological and multi-omics responses of Neoporphyra haitanensis to dehydration-rehydration cycles

BackgroundSeaweeds in the upper intertidal zone experience extreme desiccation during low tide, followed by rapid rehydration during high tide. Porphyra sensu lato are typical upper intertidal seaweeds. Therefore, it is valuable to investigate the adaptive mechanisms of seaweed in response to dehydration-rehydration stress.ResultsA reduction in photosynthetic capacity and cell shrinkage were observed when N. haitanensis was dehydrated, and such changes were ameliorated once rehydrated. And the rate and extent of rehydration were affected by the air flow speed, water content before rehydration, and storage temperature and time. Rapid dehydration at high air-flow speed and storage at − 20 °C with water content of 10% caused less damage to N. haitanensis and better-protected cell activity. Moreover, proteomic and metabolomic analyses revealed the abundance members of the differentially expressed proteins (DEPs) and differentially abundant metabolites (DAMs) mainly involved in antioxidant system and osmotic regulation. The ascorbic acid-glutathione coupled with polyamine antioxidant system was enhanced in the dehydration response of N. haitanensis. The increased soluble sugar content, the accumulated polyols, but hardly changed (iso)floridoside and insignificant amount of sucrose during dehydration indicated that polyols as energetically cheaper organic osmolytes might help resist desiccation. Interestingly, the recovery of DAMs and DEPs upon rehydration was fast.ConclusionsOur research results revealed that rapid dehydration and storage at − 20 °C were beneficial for recovery of N. haitanensis. And the strategy to resist dehydration was strongly directed toward antioxidant activation and osmotic regulation. This work provided valuable insights into physiological changes and adaptative mechanism in desiccation, which can be applied for seaweed farming.

Oral Ondansetron Reduces IV Fluid Use in the Emergency Department

Oral Ondansetron Reduces IV Fluid Use in the Emergency Department

Convective drying of spine gourd ( Momordica dioica ): Effect of ultrasound pre‐treatment on drying characteristics, color, and texture attributes

The present study aimed to explore the effect of ultrasound pre-treatment (USPT) and convective drying on the drying characteristics on the quality attributes of spine gourd (SG). The drying and rehydration characteristics were the best described by the Page model. USPT, as well as an increase in drying temperature, enhanced the drying rate of SG. USPT reduced the drying time whereas the sample dried at low temperature having higher rate of rehydration. The combined effect of USPT and drying temperature increased the moisture diffusivity of the sample from 8.55 × 10–10 to 2.63 × 10–9 m2/s. USPT of sample lowered the activation energy (34.57–29.43 kJ/mol) and increase in shrinkage. An increase in the drying temperature increased brittleness and crispiness but adversely affected the color. The higher retention of natural color favors the better acceptability of product dried at low-temperature drying (50°C) than control and others. Practical applications Limited studies have focused on the drying of spine gourd (SG). This study will add scientific data on the drying of SG with and without US. Dried slices can be directly cooked and break the barrier of seasonal availability. Dried crisp slices can be directly consumed as chips with spices.

Nasogastric Drip Rehydration Therapy in Acute Diarrhea with Severe Dehydration

WHO recommended severe dehydration without shock in acute diarrhea to be rehydrated by nasogastric drips (NGD) of oral rehydration solution (oralit). In this respect the criteria of a still palpable and countable pulse, the absence of meteorism and absence of complication, the reverse warranting iv fluid therapy, can be used as practical guidelines to identify the patient "without shock".
 A clinical trial comparing the result of NGD oralit rehydration therapy to that of intravenous Ringer-lactate on small children with diarrhea and severe dehydration was conducted. Seventy jive patients admitted to the Department of Child Health Palembang General Hospital from January up to July 1986, aged 1 to 59 months, suffering from acute diarrhea with severe dehydration fulfilled to above mentioned criteria. Randomly 36 were assigned to NGD rehydration therapy using WHO standard ORS (in Indonesia is named as oralit) and 39 were rehydrated with iv Ringer lactate solution, given in four hours consisting of 40ml/kg BW, 30ml/kg BW, 20 ml/kg BW and 20ml/kg BW in the first, second, third and fourth hours respectively.
 Based on the failure rate of rehydration in the first four hours, the recurrence of dehydration after rehydration and the side effects of fluid therapy, it was concluded that acute diarrhea cases with severe dehydration who fulfilled the above mentioned criteria can be rehydrated by NGD oralit as effective and safe as by iv Ringer lactate.

Rate of drying influences tolerance of low water contents in the moss Funaria hygrometrica (Funariaceae)

Desiccation tolerance (DT) in poikilohydric organisms is dependent upon four principal sequential factors, (1) the rate of drying (RoD), (2) the water content (WC) of the organism deriving from the equilibrating relative humidity (RHeq), (3) the duration of the desiccation event, and (4) the rate of rehydration (RoR). The first two factors are often combined in experiments as the “intensity” of desiccation, and thus the effect of one on the other is relatively unknown but likely to be important ecologically. We hypothesized that more protracted rates of drying should mitigate damage at lower equilibrating RHs in a known inducibly DT species. Cultured uniclonal shoots of the moss Funaria hygrometrica were dried at different RoDs (time from full turgor to leaf curling, from 0.067 to 120 h) at five different RHs (12, 33, 54, 75 and 93%), allowed to equilibrate at each RH, rehydrated and assessed using chlorophyll fluorescence at 0.5 and 24 h postrehydration. At 24 h postrehydration, shoots of F. hygrometrica subjected to a rapid-dry event (<10 min) were unable to recover to control levels of fluorescence (Fv/Fm and ΦPSII <80% of control levels) when equilibrated at RHeqs of ≤54%. Recovery was improved when the rate of drying was extended for more than ∼15 hours from full turgor to the onset of leaf curling at these RHeqs. When shoots were rapidly dried at RHeqs >54%, recovery was complete. At 0.5 h postrehydration, Fv/Fm levels indicated moderate damage at all RHeqs except 93%, with no mitigation of damage when the rate of drying was extended. Intensity of desiccation is normally construed as the ability to tolerate a combination of rate of drying × equilibrating RH. By varying the rate of drying across a range of RHeqs, F. hygrometrica is found to be able to tolerate all water contents tested, providing the rate of drying is extended to at least 15 h from full turgor to leaf curling. By adopting either the “step-down” approach to drying or the “wet substrate” technique used here, future studies on the desiccation tolerance of poikilohydric organisms can more accurately assess responses to desiccation stress.

Influence of vacuum impregnation pretreatment combined with IR drying on quince quality with shrinkage modeling by ANN

The effects of infrared power on drying behavior of quince slice were investigated. The samples were pretreated under vacuum impregnation (VI) and atmospheric pressure with sucrose sirup. The quality attributes measured included moisture content, bulk density rehydration, water loss, solid gain, texture, porosity, color, non-enzymatic browning, and effective moisture diffusivity. In addition, the modeling of shrinkage by ANN. VI increased the effective moisture diffusivity, bulk density, and softening of the dried fruit tissues while decreasing the time of drying (p < 0.05). The highest porosity was observed for the control samples treated under VI and dried at 1200 W. The desired color was achieved in the osmotic samples treated under atmospheric conditions and dried at 800 W. The rate of rehydration was reduced in the osmotic samples under vacuum. MLP neural network was used to model the shrinkage of the best topology 3-3-1 by LM learning algorithm and threshold function of Tangent sigmoid function, with a correlation coefficient of 0.9963 and the error MSE of 0.000340.

The role of prehydration in rescuing shoots of mosses damaged by extreme desiccation events: Syntrichia norvegica (Pottiaceae)

While regarded as a principal factor of desiccation tolerance in bryophytes (along with rate of drying, water content and duration dry), the rate of rehydration has been broadly neglected or inadequately assessed. Prior to receiving liquid water from a rain event, desiccated bryophytes are able to partially rehydrate their tissues by absorbing water vapor when ambient relative humidity is high, a process known as prehydration. A single clone of Syntrichia norvegica was cultured for 4–6 months in a suprasaturated condition. Shoot apices were used in experimental prehydrating (1–48 h), drying (5 min–300 h, equilibrating at ∼0% relative humidity), and duration dry (0–42 d continuously dry at 54% RH) series. Shoots were subsequently prehydrated 24 h prior to exposure to liquid water or directly immersed in liquid water and assessed for desiccation associated damage. Prehydration occurs over a 4-h period, after which shoot water content levels out. Shoots that normally die when equilibrated at low water contents were rescued with a prehydration treatment. At extremely rapid rates of drying (<20 min) prehydration effects were limited. However, at gradual rates of drying the prehydration treatment restored chlorophyll fluorescence and regeneration capacity to near control levels. Prehydration also improved the capacity of a shoot to recover following continuously dry episodes of several weeks. Without a prehydration treatment, shoot apices of the moss Syntrichia norvegica were killed by desiccation to equilibrium with 0% RH, and severely damaged upon rehydration from a 42-d dry period. With a prehydration treatment, both of these scenarios were mitigated. For the prehydration treatment to be effective, a rate of drying only of 30 or more minutes from full turgor without external free water to leaf curling achieves a significant lessening of damage.

Activated mineral powders for asphalt concrete mixture

Possibilities of activation of disperse mineral powders from the technogenic raw materials of KMA by ultraviolet irradiation are considered in this article. The optimum time of ultraviolet exposure for each material is determined during which the concentration of exchange centers is increased, the rate of rehydration is slowed down and the moisture absorption is significantly reduced. It is shown that both physical and mechanical characteristics, as well as durability of asphalt concrete prepared on the basis of modified mineral powders are significantly increased.

Rapid intravenous rehydration of children with acute gastroenteritis and dehydration: a systematic review and meta-analysis

BackgroundThe World Health Organization (WHO) recommends rapid intravenous rehydration, using fluid volumes of 70-100mls/kg over 3–6 h, with some of the initial volume given rapidly as initial fluid boluses to treat hypovolaemic shock for children with acute gastroenteritis (AGE) and severe dehydration. The evidence supporting the safety and efficacy of rapid versus slower rehydration remains uncertain.MethodsWe conducted a systematic review of randomised controlled trials (RCTs) on 11th of May 2017 comparing different rates of intravenous fluid therapy in children with AGE and moderate or severe dehydration, using standard search terms. Two authors independently assessed trial quality and extracted data. Non-RCTs and non-English articles were excluded. The primary endpoint was mortality and secondary endpoints included adverse events (safety) and treatment efficacy.Main resultsOf the 1390 studies initially identified, 18 were assessed for eligibility. Of these, 3 studies (n = 464) fulfilled a priori criteria for inclusion; most studied children with moderate dehydration and none were conducted in resource-poor settings. Volumes and rates of fluid replacement varied from 20 to 60 ml/kg given over 1-2 h (fast) versus 2-4 h (slow). There was substantial heterogeneity in methodology between the studies with only one adjudicated to be of high quality. There were no deaths in any study. Safety endpoints only identified oedema (n = 6) and dysnatraemia (n = 2). Pooled analysis showed no significant difference between the rapid and slow intravenous rehydration groups for the proportion of treatment failures (N = 468): pooled RR 1.30 (95% CI: 0.87, 1.93) and the readmission rates (N = 439): pooled RR 1.39 (95% CI: 0.68, 2.85).ConclusionsDespite wide implementation of WHO Plan C guideline for severe AGE, we found no clinical evaluation in resource-limited settings, and only limited evaluation of the rate and volume of rehydration in other parts of the world. Recent concerns over aggressive fluid expansion warrants further research to inform guidelines on rates of intravenous rehydration therapy for severe AGE.

Ecology of desiccation tolerance in bryophytes: A conceptual framework and methodology

Bryophytes have long been understood to be desiccation tolerant (capable of reviving from an air-dry state, DT). While mechanistic studies focusing on the expression of this complex trait are numerous over the last 50 years, a firm conceptual framework for the ecology of desiccation tolerance in bryophytes has lagged behind. As a result of this, mechanistic studies have gone ahead without an ecological foundation, and this path can be scientifically risky. The motivating elements for this article include (1) the low visibility and lack of implementation of a conceptual framework for studying the ecology of DT in bryophytes, (2) the lack of a protocol for the step-by-step handling of field-collected or laboratory cultured specimens for study of desiccation tolerance with particular attention to the deacclimation of plants, (3) a recognition that most studies of desiccation tolerance tend to conflate two of the most important factors of desiccation, rate of desiccation and water content, and (4) recognizing that the ecological factors of rehydration, aside from recovery, are nearly always ignored in experiments on desiccation tolerance in bryophytes. Therefore this review postulates a conceptual framework for the ecology of desiccation tolerance, presenting the principal factors of desiccation (rate of drying, water content at equilibration, duration dry, and rate of rehydration) and how they may interact, presenting the principal physiological phases of rehydration (recovery, hardening, dehardening), and highlighting the importance of specimen handling in preparation for an experiment on DT. Useful metrics for assessment are derived that include the minimum rate of drying tolerated at a given water content, the minimum or maximum water content tolerated, the maximum duration dry tolerated, and the minimum dehardening time exhibited.

Dehydration and rehydration of Zn-hydroxy sulfate minerals with interrupted decorated hydroxide sheets

The dehydration-rehydration processes of three Zn-hydroxy sulfate minerals with interrupted decorated sheet structures – osakaite, gordaite and Ca-gordaite were investigated. The obtained products and processes were characterized by DTA-TG-MS, in situ and ex situ PXRD and FTIR.In osakaite structure the two different positions of water molecules cause different ways of dehydration. The derivation of each interlayer molecule results in the formation of discrete phases, with 4, 3 and 1 H2O, without any evidence for dihydrate formation. The process was conducted by both heating and adsorption. The rehydration of these metaphases proceeds reciprocally to the dehydration with relatively high rate at middle and high RH values. The derivation of water molecules from the Zn tetrahedron occurs only on heating. The derivation of only half of the apical molecules was observed. The rehydration of formed hemihydrate metaphase proceeds very slowly even at high RH values. The fully dehydrated phase thus proved to be impossible to form. Structural schemes of monohydrate and hemihydrate phases were proposed. In osakaite structure type all changes occur on the surface of the hydroxide layer, preserving its electrically neutral character, with further possible implications for facilitating intercalation of polar molecules.The negatively charged surface of gordaite hydroxide layer, caused by the occupation of apical position of Zn tetrahedra by Cl− determine dehydration behavior, similar to that of montmorillonite and vermiculite structures. On heating, gordaite and Ca-gordaite form three and two pillared structures with different sizes of interlayer space and different amount of water molecules for each phase. The rate of dehydration and/or rehydration and particular quantity of derived water molecules is controlled by the interlayer cations. In accordance with the high ionic potential of calcium, the dehydration of Ca-gordaite occurs only on heating and the rehydration proceeds at very low RH conditions. To the contrary, the much lower ionic potential of sodium causes the formation of dehydrated gordaite phases by both heating and by adsorption. Similarly to the montmorillonite and vermiculite – these two gordaite minerals can be expected to be used for both cation exchange for interlayer cations and anionic exchange of apical Cl−anion.

Modelling of Rehydration of Freeze-dried Dumpling Wrapper

It was aimed to assess the impact of rehydration process of freeze-dried dumpling wrapper on their property and rate of rehydration, it is necessary to study the temperature effect; therefore the rehydration kinetic of freeze-dried dumpling wrapper was investigated at temperature of 308, 343 and 373 K, respectively. Fick Diffusion theory, Peleg model and Weibull model were used to describe rehydration process. The results show that: the predictions with Peleg model and Weibull model are in good agreement with experimental data. The study on rehydration process will help understand rehydration characteristics and rehydration mechanism of dry foodstuff and provide theoretical guidance for the freeze-dried food.

Heat acclimation and thirst in rats.

The effects of heat acclimation on water intake and urine output responses to thermal dehydration and other thirst stimuli were studied in male Sprague-Dawley rats. Rats were heat acclimated by continuous exposure to a 34°C environment for at least 6weeks. Thermal dehydration-induced thirst was brought about by exposing the heat-acclimated rats and control rats housed at 24°C to a 37.5°C environment for 4h without access to food or water. Heat acclimation reduced evaporative and urinary water losses and the increases in plasma sodium and osmolality during thermal dehydration, which led to a reduction in thermal dehydration-induced thirst. Heat acclimation reduced the rate of rehydration following thermal dehydration but did not alter the final rehydration level, indicating that heat acclimation does not alter the primary control of thermal dehydration-induced thirst. Heat acclimation did not alter water intake or urine output following administration of hypertonic saline, which selectively stimulates intracellular thirst, but led to greater water intake following administration of angiotensin II, which plays an important role in extracellular/volemic thirst, and following water deprivation, which activates both thirst pathways. Cardiovascular responses to angiotensin II were not altered by heat acclimation. Heat acclimation thus reduces water loss during heat exposure in rats, but does not have major effects on thermal dehydration-induced or extracellular thirst but does appear to alter volemic thirst.

Linking increased airway hydration, ciliary beating, and mucociliary clearance through ENaC inhibition.

Airway dehydration causes mucus stasis and bacterial overgrowth in cystic fibrosis and chronic bronchitis (CB). Rehydration by hypertonic saline is efficacious but suffers from a short duration of action. We tested whether epithelial sodium channel (ENaC) inhibition would rehydrate normal and dehydrated airways to increase mucociliary clearance (MCC) over a significant time frame. For this, we used a tool compound (Compound A), which displays nanomolar ENaC affinity and retention in the airway surface liquid (ASL). Using normal human bronchial epithelial cultures (HBECs) grown at an air-liquid interface, we evaluated in vitro potency and efficacy using short-circuit current (I(sc)) and ASL height measurements where it inhibited I(sc) and increased ASL height by ∼ 50% (0.052 μM at 6 h), respectively. The in vivo efficacy was investigated in a modified guinea pig tracheal potential difference model, where we observed an effective dose (ED50) of 5 μg/kg (i.t.), and by MCC measures in rats and sheep, where we demonstrated max clearance rates at 100 μg/kg (i.t.) and 75 μg/kg (i.t.), respectively. Acute cigarette smoke-induced ASL height depletion in HBECs was used to mimic the situation in patients with CB, and pretreatment prevented both cigarette smoke-induced ASL dehydration and lessened the decrease in ciliary beat frequency. Furthermore, when added after cigarette smoke exposure, Compound A increased the rate of ASL rehydration. In conclusion, Compound A demonstrated significant effects and a link between increased airway hydration, ciliary function, and MCC. These data support the hypothesis that ENaC inhibition may be efficacious in the restoration of mucus hydration and transport in patients with CB.

Hot air and microwave drying of pomegranate (Punica granatum L.) arils

In this study, arils of Hicaz type pomegranates were dried by hot air and microwave drying technique. Drying behavior, shrinkage, rehydration, bulk density and color changes of the products were investigated. Hot air drying process was carried out at three different temperatures; 50, 60 and 70 °C at 1.0 m/s air velocity. Also, three microwave power levels (210, 350, and 490 W) were studied as another drying technique. Among the several models listed in literature, the Page drying model was appropriate for both convective and microwave drying of the pomegranate arils drying. Increasing drying temperature and power intensity shortened the drying time of arils. Rate of drying was higher when microwave (5.83 × 10−3 - 2.85 × 10−2) used compared to air drying process (1.52 × 10−4 - 1.70 × 10−3). It was observed that shrinkage of air dried samples was higher than microwave dried sample. Rate of rehydration of microwave dried aril samples was relatively faster than air dried samples, but not significant statistically. However, bulk density of air dried samples was higher than those of microwave dried sample.

Dehygration and Rehydration of Fufu

The study is aimed at determining if cassava fufu can be dehydrated and to measure the rate of dehydration; subsequently the dried product would be dehydrated to establish whether it will return to the original fufu properties. The experiment were performed in other to obtain the rate of dehydration and rehydration using the lick’s second law of diffusion between each time interval, during the experiment, three fufu samples was used in the experiment i.e. normal cooked, half cooked and over cooked fufu. The plots of dehydration and rehydration rate with moisture content, moisture content with time and their rates with time, were made for each sample showing the characteristics of fufu. It was observed that sample 1 has first falling rate of period of 0.36 – 0.12, second falling rate period of 0.12 – 0.03 at moisture content of 11.20% - 39.41% and the dehydration rate of 0.02 -0.98, sample 2 has first falling rate period of 0.32 – 0.23, second falling rate period of 0.11 – 0.06, second falling rate period of 0.06 – 0.01 at moisture content falling rate period of 34.29% - 31.67% and rehydration rate of 0.03 – 1.69 at moisture content of 28.32% - 48.75%. This will help in knowing the determination, nutritive value and shelf life of fufu.

Pediatric Diabetic Ketoacidosis: Is Fluid Replacement Rate Associated with Cerebral Edema?

Does rate of rehydration affect the development of cerebral edema in children with diabetic ketoacidosis (DKA)? To find out, investigators used

Change of plasma volume, osmolality, and acid–base status in healthy calves after feeding of milk and water- and milk-based oral rehydration solutions

Oral rehydration solutions (ORS) are a simple and cheap method to treat diarrheal dehydration and acidosis. To maintain the energy supply of diarrheic calves, it is necessary to continue milk feeding. Suckling of milk or milk-based or hypertonic water-based ORS produces a slower rate of abomasal emptying than suckling isotonic water-based ORS. The faster abomasal passage of isotonic water-based ORS implies that efficacious electrolytes reach the gut more quickly, possibly providing a faster rate of rehydration. The aim of the study was to verify when and to what extent milk and water- and milk-based ORS increase plasma volume and affect plasma osmolality and acid–base status in healthy suckling calves. Eleven calves were fed with milk and with an ORS that was prepared in water or milk. Moreover, for one experiment, the calves remained fasting without suckling milk or ORS. During the experimental phase, the calves were deprived of water, hay, and concentrates. Blood samples were taken before and at various time points after feeding. Total plasma protein, osmolality, [Na+], [K+], [Cl−], and albumin were determined. In 6 of 11 experiments, blood gas analysis was also performed. The calculated change in plasma volume after feeding was assessed from the plasma protein concentration before feeding (Pt=0) and the plasma protein concentration after feeding (Pt=x): (Pt=0− Pt=x) × 100/Pt=x. Water- and milk-based ORS produced equal rates of plasma expansion in healthy calves. After milk feeding, the change in plasma volume was decelerated. Because of water influx, we did not observe a significant effect of feeding regimen on plasma osmolality. Acid–base status was little affected by feeding regimen. Feeding of milk-based ORS increased plasma strong ion difference, an alkaline response, which could potentially also reduce acidosis in calves suffering from diarrhea.

The impact of an oral rehydration clinical pathway in a paediatric emergency department

To measure the impact of implementing an oral rehydration clinical pathway for children with mild to moderate dehydration from gastroenteritis in the paediatric emergency department (ED) on the indicators of health care utilization. ED charts of children, six months to 17 years of age, meeting the criteria for the oral rehydration clinical pathway were reviewed. There were three 12-month periods of data collection: pre-implementation, transition and postimplementation. The clinical pathway consisted of a standard nursing assessment form and instructions on oral rehydration to be initiated and maintained by caregivers while waiting to see a physician. The primary outcome measure was ED length of visit (LOV) for children treated using the clinical pathway. This was compared with LOV for all other ED visits during the study periods to highlight the effect of the clinical pathway implementation. Secondary outcome measures included rate of intravenous rehydration, unscheduled return visits to the ED and hospital admission. During the three data collection periods, 11,816 children met the eligibility criteria. A decrease in the mean LOV of 24 min (95% CI 17 to 31) was observed, as well as a trivial decrease in the rate of intravenous rehydration therapy (14.6% to 12%) with implementation of the clinical pathway. The implementation of an oral rehydration clinical pathway in the ED led to a modest reduction in the ED LOV.

Ultrastructural evaluation of human metaphase II oocytes after vitrification: closed versus open devices

To compare the ultrastructural appearance of oocytes after vitrification and warming with two different devices. Oocytes were examined by ultrastructural analysis after vitrification and warming with use of closed (CryoTip; Irvine Scientific, Santa Ana, CA) or open (Cryotop; Kitazato BioPharma Co., Ltd., Shizuoka, Japan) devices. Pordenone Hospital IVF Unit and Medical Morphological Research Department, University of Udine. Surplus oocytes from 10 patients (aged 31-39 years) undergoing assisted reproductive technologies at the Pathophysiology Unit of Human Reproduction and Sperm Bank between 2006 and 2008. Oocytes with normal invertoscopic appearance underwent vitrification and warming with closed (CryoTip) or open (Cryotop) devices and were processed for transmission electron microscopy. Cryodamage extent and cell alterations in oocytes after open or closed vitrification and warming procedures and their rehydration rate. A higher rate of complete oocyte rehydration and less-severe ultrastructural alterations were observed after vitrification and warming with the open Cryotop device. These preliminary data suggest that oocyte ultrastructure is better preserved with an open rather than closed vitrification and warming protocol.