Dehydration Treatment Research Articles

Diffusional analysis and textural properties of coated strawberries during osmotic dehydration treatment

BACKGROUND: The use of polysaccharide based edible coatings as a barrier against the solute entry of high caloric constituents, such as sucrose, is a suitable strategy to develop pro-healthy osmo-dehydrated products. OBJECTIVE: This work aims to study the effect of a calcium alginate film over the drying kinetics of strawberries during an osmotic dehydration (OD) treatment at 60°Brix, 4 h, 40°C (sucrose). Also, textural parameters were evaluated. METHODS: It was determined the changes in some selected physical properties, such as: moisture, total solid contents, one-dimensional shrinkage and texture, at 30 min steps during OD treatment. Besides, water and solid diffusion coefficients ( D e W and D e TS , respectively) were calculated by using the analytical solution of Fick’s equation. RESULTS: Diffusion coefficients for water and solids showed significant differences due to coating presence as an evidence of the barrier effect. Coated strawberry samples presented several changes after 2 h of OD treatment at the assayed conditions for most of the parameters evaluated. CONCLUSIONS: Alginate coating at the tested conditions acts as a barrier to sucrose influx and to water outflux until 2 and 3 h of OD treatment, respectively. Besides, a good textural quality for osmotically-dehydrated strawberries was obtained.

Changes in the psysical-chemical composition, total polyphenols and antioxidant activity of fresh celery (Apium graveolens L.) dehydrated by hot air and by lyophilization

The food industry aims at offering food that provides not only nutritional but also functional properties. Celery has been used for a long time, but its bioactive compounds have remained unknown. The objective of this research is to measure the changes in the physical and chemical characteristics, total polyphenols (TP) and antioxidant activity (AA) after applying hot air dehydration (DA) and lyophilization (LF) with two different cut types: rod-shaped (R) and sliced (S). It was found that dehydration treatments can enhance some characteristics in celery. When comparing the results, the treatment of (LF-S) presented the best characteristics with less water activity, 46 % of total dietary fiber constituted by 41 % of insoluble fiber and 5 % soluble fiber, 377.69 mg GAE/100g in total polyphenol content and an antioxidant activity of 82.17 μmol TE/100g. These results allow to conclude that celery is a raw material with functional attributes and that it can be industrialized with dehydration technologies, which will enable a long useful life for its bioactive compounds.

PI signal transduction and ubiquitination respond to dehydration stress in the red seaweed Gloiopeltis furcata under successive tidal cycles

BackgroundIntermittent dehydration caused by tidal changes is one of the most important abiotic factors that intertidal seaweeds must cope with in order to retain normal growth and reproduction. However, the underlying molecular mechanisms for the adaptation of red seaweeds to repeated dehydration-rehydration cycles remain poorly understood.ResultsWe chose the red seaweed Gloiopeltis furcata as a model and simulated natural tidal changes with two consecutive dehydration-rehydration cycles occurring over 24 h in order to gain insight into key molecular pathways and regulation of genes which are associated with dehydration tolerance. Transcription sequencing assembled 32,681 uni-genes (GC content = 55.32%), of which 12,813 were annotated. Weighted gene co-expression network analysis (WGCNA) divided all transcripts into 20 modules, with Coral2 identified as the key module anchoring dehydration-induced genes. Pathways enriched analysis indicated that the ubiquitin-mediated proteolysis pathway (UPP) and phosphatidylinositol (PI) signaling system were crucial for a successful response in G. furcata. Network-establishing and quantitative reverse transcription PCR (qRT-PCR) suggested that genes encoding ubiquitin-protein ligase E3 (E3–1), SUMO-activating enzyme sub-unit 2 (SAE2), calmodulin (CaM) and inositol-1,3,4-trisphosphate 5/6-kinase (ITPK) were the hub genes which responded positively to two successive dehydration treatments. Network-based interactions with hub genes indicated that transcription factor (e.g. TFIID), RNA modification (e.g. DEAH) and osmotic adjustment (e.g. MIP, ABC1, Bam1) were related to these two pathways.ConclusionsRNA sequencing-based evidence from G. furcata enriched the informational database for intertidal red seaweeds which face periodic dehydration stress during the low tide period. This provided insights into an increased understanding of how ubiquitin-mediated proteolysis and the phosphatidylinositol signaling system help seaweeds responding to dehydration-rehydration cycles.

PtrCDPK10 of Poncirus trifoliata functions in dehydration and drought tolerance by reducing ROS accumulation via phosphorylating PtrAPX

Calcium-dependent protein kinases (CDPKs) are important calcium signaling components that have been shown to play crucial roles in modulating plant abiotic stress responses. However, the physiological and regulatory roles of most CDPKs are still poorly understood. Here, we report the functional characterization of PtrCDPK10 from trifoliate orange (Poncirus trifoliata (L.) Raf.) in dehydration and drought stress tolerance. PtrCDPK10, categorized in the Type III subgroup of the CDPK family, was localized to the nucleus and plasma membrane. Transcript levels of PtrCDPK10 were up-regulated by dehydration, salt and ABA treatments. Transgenic trifoliate orange plants overexpressing PtrCDPK10 showed enhanced dehydration tolerance compared with the wild type (WT), whereas VIGS (virus-induced gene silencing)-mediated knockdown of PtrCDPK10 resulted in elevated susceptibility to dehydration and drought stresses. Yeast two-hybrid screening identified several proteins that interacted with PtrCDPK10, including an ascorbate peroxidase (PtrAPX). PtrCDPK10 was shown to phosphorylate PtrAPX based on an in vitro kinase assay. PtrCDPK10-overexpressing transgenic lines exhibited higher PtrAPX mRNA abundance and APX activity and accumulated dramatically less ROS in comparison with the WT, while PtrCDPK10-silenced VIGS lines showed decreased PtrAPX expression and increased ROS level. Taken together, these results demonstrate that PtrCDPK10 promotes dehydration and drought tolerance by, at least in part, phosphorylating APX to modulate ROS homeostasis.

Development of an Efficient ‘One-Step Freezing’ Cryopreservation Protocol for a Georgian Provenance of Chestnut (Castanea sativa Mill.) Zygotic Embryos

Experiments were performed to determine the influence of various dehydration and vitrification treatment times on the ‘one-step freezing’ cryopreservation of embryonic axes (EAs), composed of zygotic embryos and cotyledon residuals, from mature seeds of a Georgian provenance of chestnut (Castanea sativa Mill.). Dehydration was carried out in laminar flow hood from 1 to 5 h, and vitrification experiments were carried out by immersion of EAs in PVS2 vitrification solution up to 120 min, both followed by direct immersion in liquid nitrogen. Both systems resulted in inducing specimen tolerance to ultra-rapid freezing, although to a different extent. Full germination of cryo-stored EAs after 5 h of dehydration (reducing moisture content from initial 66% to 21%) has been increased from 0% to 66.7%. A pre-treatment of EAs in PVS2 vitrification solution for 30 min produced fully developed plantlets at a rate of 55.6% in post-cryopreservation. Plantlet regrowth from cryopreservation was faster in EAs that underwent the dehydration/‘one-step freezing’ procedure. All the plantlet from cryopreserved EAs could be easily acclimatized, producing healthy potted plants. Finally, the TTC test showed to be useful for a fast evaluation of specimen survival after thawing and, as a consequence, to speed up the development of optimized cryo-protocols.
 
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 In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue.
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Central Venous Pressure (CVP) Reduction Associated With Higher Cardiac Output (CO) Favors Good Prognosis of Circulatory Shock: A Single-Center, Retrospective Cohort Study.

Background: The Frank-Starling curve is the basis of hemodynamics. Changes in cardiac output (CO) caused by central venous pressure (CVP) are the most important concerns in the treatment of critically ill patients.Objectives: To explore the use of CVP and its relevant mechanisms with respect to CO in the clinic.Methods: A total of 134 patients with circulatory shock were retrospectively included and analyzed. Hemodynamic data were recorded and analyzed at PICCO initiation and 24 h after PICCO. Data regarding 28-day mortality and renal function were also collected.Results: The patients were divided into a CVP↑+ CO↑ group (n = 23), a CVP↑+ CO↓ group (n = 29), a CVP↓+ CO↑ group (n = 44), and a CVP↓+ CO↓ group (n = 38) based on values at PICCO initiation and 24 h after PICCO. Post- hoc tests showed that the CVP↓+ CO↑ group had a higher 28-day survival than the other groups [log-rank (Mantel-Cox) = 8.758, 95%, CI, 20.112–23.499, P = 0.033]. In terms of hemodynamic characteristics, the CVP↓+ CO↑ group had a lower cardiac function index (CFI) (4.1 ± 1.4/min) and higher extravascular lung water index (EVLWI) (11.0 ± 4.7 ml/kg) at PICCO initiation. This group used more cardiotonic drugs (77.3%, P < 0.001) and had a negative fluid balance (−780.4 ± 1720.6 ml/24 h, P = 0.018) 24 h after PICCO than the other three groups. Cardiotonic drug use and dehydration treatment were associated with increased CFI (from 4.1 ± 1.4 /min to 4.5 ± 1.3/min, P = 0.07) and reduced ELVWI (from 11.0 ± 4.7 ml/kg to 9.0 ± 3.5 ml/kg, P = 0.029). Renal function tests showed that SCr and BUN levels in the CVP↓+ CO↑ group were significantly improved (SCr from 197.1 ± 128.9 mmol/L to 154.4 ± 90.8 mmol/L; BUN from 14.3 μmol/L ± 7.3 to 11.6 ± 7.0 μmol/L, P < 0.05).Conclusions: Lower CVP was associated with increased CO, which may improve the 28-day prognosis in patients with circulatory shock. Notably, higher CO derived from lower CVP may also contribute to renal function improvement.

Dehydration risk factors and impact after bariatric surgery: an analysis using a national database.

Dehydration is a common complication after bariatric surgery and often quoted as the reason for emergency department (ED) visits and readmission. We sought to investigate risk factors for dehydration after bariatric surgery and evaluate its impact on ED visits and readmission. The Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database. We used the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database to identify patients who underwent laparoscopic sleeve gastrectomy or laparoscopic Roux-en-Y gastric bypass (LRYGB) from 2016 through 2017. The primary outcome was need for outpatient treatment of dehydration within 30 days postsurgery. Secondary outcomes were association between need for outpatient dehydration therapy and 30-day readmission or ED evaluation not resulting in admission. Of 256,817 patients, 73% underwent laparoscopic sleeve gastrectomy and 27% LRYGB. Of 9592 patients who required dehydration treatment, they were more often younger than age 40, female, black, had a ≥3-day length of stay during their index admission, and experienced a postoperative complication. More patients receiving LRYGB than laparoscopic sleeve gastrectomy required treatment for dehydration. On multivariable analysis, independent-risk factors for postoperative dehydration treatment included LRYGB, length of stay ≥3 days, gastroesophageal reflux disease, hypertension, previous deep vein thrombosis, chronic steroid/immunosuppression, and a postoperative complication. Patients who developed dehydration requiring treatment compared with those that did not had adjusted odds ratio of 3.7 (95% confidence interval: 3.44-3.96; P < .001) and 22 (95% confidence interval: 21.05-23.06; P < .001) of readmission and ED visit. Dehydration is a strong risk factor for postoperative ED visits and readmission. Closer surveillance and proactive measures for those at higher risk may prevent the development of postoperative dehydration.

Novel multi-wavelength effectively excited ZnWO4-WO3:Eu3+ multiphase red phosphor for white light-emitting diodes

The discovery of phosphor with efficient red emission is a crucial step in the development of the white light-emitting diodes (wLEDs). Herein, based on the regulation of the W/Zn ratio, the Eu3+-activated ZnWO4-WO3∙0.5H2O-WO3 multiphase phosphor was designed successfully via the one-step hydrothermal treatment route. The effects of the W/Zn ratio on the phase structure, composition, morphology, luminescence property and lifetime of the obtained samples were systematically and comparatively investigated. The obtained product not only maintains the multi-wavelength excitation feature of ZnWO4:Eu3+ phosphor, but also sharply improves the characteristic emission intensity of Eu3+ ions. It is found that the WO3∙0.5H2O crystal has a special 3D interconnected channel structure, which is a relatively much access to the chemical behavior and permits the ready insertion of part of Eu3+ ions, and this coordination environment can obtain strong pure red light emission. Further, the ZnWO4-WO3:Eu3+ phosphor obtained after dehydration treatment can be excited more efficiently in the deep-ultraviolet (DUV), near-ultraviolet (NUV) and blue light regions, and its quantum efficiencies reach 18%, 22% and 21.2%, respectively. Besides, it also exhibits better CIE chromaticity coordinate, higher color purity than commercial Y2O2S:Eu3+ phosphor. Therefore, the ZnWO4-WO3:Eu3+ is promising for the application in red phosphor with different wavelengths for wLEDs.

Relationship between loss of desiccation tolerance and programmed cell death (PCD) in mung bean (Vigna radiata) seeds.

Mung bean (Vigna radiata), an important legume crop, has the property of desiccation tolerance (DT), which is lost in the final stage of germination (preimbibition, 18 h-24 h). We compared parameters related to the programmed cell death (PCD) of mung bean seeds before and after dehydration at different imbibition stages through various detection methods. The results of Evans blue and TTC staining methods showed that the dehydration process could lead to cell death. The results of optical and subcellular morphology showed that PCD occurred after dehydration. The destruction of DNA integrity and the activity changes in caspase and total nuclease in mung bean seeds after dehydration treatment indicated that the loss of desiccation tolerance was related to PCD. Dehydration resulted in the destruction of the mitochondrial structure, reversal of the membrane potential, and the entrance of cytochrome C into the cytoplasm. These processes all indicate that the mitochondrial apoptosis pathway was the main form of dehydration-induced PCD. The results of cytoplasmic Ca2+ concentration showed that Ca2+ signaling also played a role in inducing PCD, with the upstream signal being dehydration-induced changes in water potential and the downstream signal being the ROS and mitochondrial PT channel, according to the order in which these signals happened. The mitochondrial apoptosis pathway can be considered the main mechanism of dehydration-induced PCD based on our analysis of the sequence of major events in PCD. The main processes include dehydration induction, changes in Ca2+ and mitochondrial respiratory electron transport, the reversal of mitochondrial membrane potential induced by ROS and Ca2+, and the transmission and execution of PCD downstream signals induced by cytochrome C release.

Consumer acceptability, physicochemical characteristics, and bioactive compounds of sweet potato roots subjected to osmotic dehydration

Sweet potato dehydration is a way of increasing shelf life, modifying and adding value to the final product. However, some of the compounds of nutritional interest may be lost during processing. Thus, this work evaluates dif­ferent dehydration treatments for sweet potato, and determines the best condition for a quality product. Two sweet potato genotypes (UGA 127 and UGA 34) were first subjected to osmotic dehydration using a 65% sucrose solu­tion or a 2% sodium chloride solution (NaCl), both for 5 hours, being compared with the control treatment. Subse­quently, the samples were oven dried at 65 °C for 6 hours. Sweet potatoes were analyzed for sensory character­istics (color, flavor, crispness, aroma, overall acceptability, and purchase intent), physicochemical characteristics (color, titratable acidity, soluble solids), bioactive compounds (β-carotene, phenolic, ascorbic acid), and antioxi­dant capacity. Potatoes dehydrated with 65% sucrose were well accepted by the tasters. The soluble solids con­tent and soluble solids/titratable acidity ratio were higher for sweet potatoes treated with 65% sucrose. Genotypes differed significantly for luminosity, and the highest average was found for UGA 127, indicating that potatoes pro­cessed from this root had a lighter coloration. The content of bioactive compounds varied as a function of the dif­ferent treatments and genotypes; in general, the highest levels were found in the control and 65% sucrose treat­ments. Genotype UGA 127 treated with 65% sucrose proved to be a good marketing alternative for small farmers.

Cost-effectiveness analysis of oral rehydration therapy compared to intravenous rehydration for acute gastroenteritis without severe dehydration treatment

BackgroundDiarrhea causes, annually, approximately 1.7 billion cases and 760,000 deaths worldwide among children under 5 years of age, although these are preventable and treatable. This study aim to assess the cost-effectiveness for the treatment of diarrhea in emergency services in the management of children of acute gastroenteritis with non-severe dehydration. MethodsA stochastic decision tree model considering the perspective of the Brazilian public health system was used to calculate the cost-effectiveness of the 5 interventions: oral rehydration therapy (ORT) at home, and if it fails supervised ORT; they would receive; ORT at home, and if it fails intravenous rehydration therapy (IVT). ORT at home and if it fails, the half of them will receive supervised ORT, and the other half would receive IVT; Patient receives supervised oral treatment; Patient receives IVT. Quality-adjusted life year (QALY) was used to measure the clinical outcomes. ResultsThe strategy of initiating oral rehydration in children younger than 5 is the most efficient practice with a cost of $14.28 and effectiveness of 0.89 QALYs. ConclusionORT is an underutilized resource for the management of children with non-severe dehydration in emergency services. The overprescribed IVT increases cost without a corresponding significant increase in effectiveness.

Alternative environmental friendly process for dehydration of edible Undaria pinnatifida brown seaweed by microwave hydrodiffusion and gravity

The impact of the processing conditions of the edible Undaria pinnatifida brown seaweed on the dehydration and bioactive features was determined using the green microwave hydrodiffusion and gravity technology. For the alga solid phase, the corresponding dehydration and rehydration kinetics, their mathematical modelling, volumetric shrinkage, energy consumption, microscopical and colorimetric properties, phenolic content and antioxidant capacity were analyzed. Results indicated that an increase in microwave power involved a notable drop in the seaweed dehydration time. The shortest dehydration treatment to reach an adequate final moisture content (<10% dry basis) was achieved using the following sequential procedure: 300 W (5 min), 100 W (10 min), 50 W (35 min) and 25 W (90 min). This recommended process also led to short rehydration time (10 min), uniform tissue surfaces, low total color differences and adequate bioactives contents. Experimental dehydration and rehydration kinetics were adequately fitted using Page and Peleg models, respectively. Estimated energy requirements were dramatically lower when compared to conventional seaweed drying treatment.

Preliminary Results on the Use of Oral Rehydration Fluid in the Form of Gelato for Rehydration of Patients at the Children’s Clinical University Hospital’s Emergency and Infectiology Units

Oral rehydration fluids (ORS) are used to reverse dehydration that, in case of children, mostly is due to acute gastroenteritis. The key of successful dehydration treatment is to replenish the lost water and electrolytes. This is best done by consuming oral rehydration solution, containing both salt and sugar. ORS enhances fluid absorption because sodium and glucose transport in the small intestine are coupled, and glucose promotes absorption of both sodium ions and water. Studies show that children refuse ORS due to its salty-sweet taste and unpalatability. To improve oral rehydration therapy, we hypothesized that freezing ORS containing a fruit/berry juice to a likeable texture in “gelato” form could promote oral rehydration. The results provide a basis for further development of the ORS gelato with attention to flavor, sweetness and texture.

Sustainability of black nera laying birds on pig dung meal based diets.

The study was undertaken on utilization of farm animal organic waste as feeds for livestock and poultry. Increasing feed costs and international concern for the conservation of resources have focused attention on the nutrients in animal wastes that have in the past been used largely as fertilizer or as a major source of fuel for villagers in a number of countries. Animal wastes represent a vast reservoir of cheap nutrients, particularly for ruminants. The limitation in using animal waste as feed is that it needs processing. Dehydration, ensiling, chemical and physical treatments can be used to maintain the nutrient composition and increase the palatability and feeding values of the waste. Animal waste can potentially be used not only to maintain animals in the dry time but also to encourage performance quite satisfactorily. Feeding cattle manure in poultry and pigs promotes meat and egg productivity respectively. Pig waste, when processed and properly balanced with other ingredients, may become a potential feed substitute for cattle at levels up to 30%. No differences in the quality of meat from animals fed waste have been detected, nor has there been a problem of consumer acceptance in animal products.Keywords: Black Nera Laying Birds, Pig Dung Meal, Diets, Feed Cost, Organic Waste.

The Resurgence of Measles, Mumps, and Pertussis

Although vaccines are one of the greatest scientific innovations to prevent disease and promote well-being, 1 in 10 children is not being vaccinated. This has directly contributed to the rise in vaccine-preventable diseases. Because of the high contagiousness of measles, mumps, and pertussis, innovative efforts are paramount to prevent disease outbreaks in the United States and worldwide. This article reviews measles, mumps, and pertussis; explains the resurgence of these vaccine-preventable diseases; and offers evidence-based solutions for increasing vaccination rates.

Transgenic Arabidopsis plants expressing CsBCATs affect seed germination under abiotic stress conditions

We investigated the responses of transgenic Arabidopsis plants that express cucumber branched-chain aminotransferases (CsBCATs) under abiotic or biotic stresses. The expression of CsBCAT3 and CsBCAT7 was dramatically increased by various abiotic treatments. The germination of CsBCAT3- or CsBCAT7-expressing Arabidopsis seeds was increased under salt and dehydration treatments, which was correlated with the increased or decreased expression levels of the germination-responsive genes. Although salicylic acid and jasmonic acid increased CsBCAT2 or CsBCAT7 expression, transgenic Arabidopsis plants that express CsBCAT2 or CsBCAT7 did not show the disease resistance to bacteria or fungus. Our results indicate that the CsBCATs affect seed germination of plants under abiotic stresses.

Quantitative Analysis of Main Components of Natural Gas Based on Raman Spectroscopy

Abstract Natural gas is composed of methane, ethane, propane, carbon dioxide, nitrogen, hydrogen, carbon monoxide and unknown alkane components of C4 or more (denoted as C4+) after desulfurization and dehydration treatment. The concentrations of the first seven components account for more than 90% of natural gas. When analyzing the natural gas composition using Raman spectral analysis methods, a small amount of unknown alkane components C4+ will have a negative impact on the analytical precision. In this work, a novel method that consists of an automatic decomposition algorithm of Raman spectra and a model for quantitative analysis was developed for the analysis of components of natural gas. The Raman spectrum of a natural gas sample could be decomposed into the sum of the Raman spectra of pure constituents and several Lorentz peaks by a nonlinear least-square optimization algorithm based on a linear additivity of Raman spectra. The concentration of the unknown alkane component C4+ was determined according to the area of the C-H deformation vibration peak which was common for most alkane molecules. Some training samples were used to establish the model between Raman characteristic peak areas and corresponding concentrations for each component. Compared with the existing Raman analysis methods, the new method solved the problem of analyzing natural gas containing unknown alkane components with good stability and accuracy. The experiments showed that the maximum absolute errors of this algorithm for methane, ethane, propane, carbon dioxide, nitrogen, hydrogen, and carbon monoxide respectively reached 0.57%, 0.37%, 0.21%, 0.07%, 0.18%, 0.04%, 0.13%, and the correlation coefficient to gas chromatographic results also reached 0.997, 0.986, 0.991, 0.998, 0.993, 1.000, 0.995, 0.982, respectively.

Hydro-Priming and Hydration-Dehydration Treatment Improve Seed Invigoration and Biotic Stress Tolerance

Weed infestation and biotic stresses often deteriorate seed quality and viability of crops by several mechanisms. The objective of the present study is to assess the methodology to increase seed viability by two consecutive hydration and dehydration treatments of hydro-primed crop seeds under biotic stresses. The effect of treatments was assessed in Solanum melongena L. as target crop and Amaranthus spinosus L. and A. viridae L. as weed species used as stress agent. The physiological parameters like germination percentage, seed viability, and vigor of target crop were increased by a factor of twice to thrice while T50 values were reduced after treatments with the association of weed plants. While the biochemical parameters like leaching of soluble carbohydrates, proteins, amino acids, and electrolytes were reduced after treatments compared to the untreated one. The proline content was also increased in the treated seed samples. The activity of amylase was decreased while dehydrogenase was increased after treatments. Thus the hydro-priming and hydration-dehydration treatments had improved seed health and lesser weed seed viability. Therefore, hydro-priming-hydration-dehydration treatment of target crop plants might be helpful to increase crop yield and also to reduce the stress effects due to biotic stress factors in the agricultural fields.

Optimized Method for Electrical Impedance Tomography to Image Large Area Conductive Perturbation

The objective of the study was to develop an optimized method for dynamic electrical impedance tomography (EIT) to image large area conductive perturbation (LACP), a new type of imaging target that we found during the monitoring and evaluation of the mannitol dehydration treatment of patients with brain edema based on brain EIT. Previously, we reconstructed LACP images with the commonly used NOSER algorithm with polar driven pattern. However, conductivity changes near the center of the LACP were blurred or remained undetected, and blocky artifacts appeared in the reconstructed images, making the interpretation of the results difficult. To solve this problem, we, for the first time, propose an optimized algorithm for imaging LACP. This algorithm comprises a modified sensitivity matrix to compensate for the blurred conductivity changes near the center. It also uses the Markov random field constraint to reduce blocky artifacts. To verify the performance of the proposed method, we conducted experiments based on head models and human subjects. Specific metrics, including shape error (SE) and image fluctuation (IF) artifacts, were also proposed to evaluate the image quality of the LACP. The experimental results demonstrated that, compared with the NOSER algorithm, the proposed method could respectively reduce SE and IF by 51.7% and 47.5%. Therefore, it can optimize the imaging of LACP and provide references for other applications at present or in the future which involve imaging LACP.

Recycling of isopropanol for cost-effective, environmentally friendly production of carboxymethylated cellulose nanofibrils

An approach to recycling isopropanol used in the carboxymethylation of pulp fiber was investigated as a cost-effective and environmentally friendly method of producing cellulose nanofibrils (CNF). Carboxymethylation of pulp fiber was carried out using isopropanol (IPA) as the sole solvent. IPA was recovered after carboxymethylation reaction and recycled in the next carboxymethylation reaction. Simple recycling of IPA decreased the reaction efficiency of carboxymethylation due to the increase of water content in the IPA. To dehydrate the recovered IPA, a 4 Å molecular sieve was used as a drying material. It was shown that dehydration restored carboxymethylation efficiency to the same level as when fresh IPA was used. The characteristics of the carboxymethylated CNFs produced using the recycled IPA were evaluated, including fibrillation tendency, average width, and width distribution, and it was shown that the use of recycled IPA after dehydration treatment did not cause any changes in carboxymethylated CNF properties. Recycling IPA after simple dehydration using a molecular sieve is thus a cost-effective and environmentally friendly method of producing carboxymethylated CNF.