Acetone Dehydration Research Articles

Optimized protocol for high-vacuum scanning electron microscopy analysis of polyacrylamide hydrogel-attached sperm cells in a binary system.

A protocol for the analysis of a binary system comprising polyacrylamide hydrogel-attached sperm cells using high-vacuum scanning electron microscopy (SEM) is presented. This protocol focuses on optimizing the SEM procedure to obtain accurate and detailed imaging of the sperm cells and their interactions with the hydrogel scaffold. The methodology involves a stepwise sample preparation, including sample dehydration through a gradual exchange of ethanol/water ratios, followed by the application of a conductive metal coating. By employing this modified protocol, the traditional use of acetone dehydration, which may introduce chemical alterations to the materials, is avoided. The proposed approach enables a comprehensive evaluation of the morphology and interactions within the biological system in contact with the soft material scaffold. Furthermore, the potential application of this protocol extends to the study of other mammalian reproductive cells or cells of different origins adhered to hydrogel scaffolds. RESEARCH HIGHLIGHTS: Novel SEM protocol reveals precise imaging of sperm-hydrogel attachment in a binary system, enhancing our understanding of cell-material interactions. By optimizing SEM procedures, the protocol achieves precise imaging of sperm-hydrogel interactions using ethanol/water dehydration and a conductive metal coating. This modified approach enables a thorough assessment of morphology and interactions in the binary system,extending its potential applicability to other reproductive cells on hydrogelscaffolds.

Separation of acetone‐water mixtures by pervaporation using NaMMT‐loaded PVA‐chitosan nanocomposite IPN membranes

AbstractNaMMT clay incorporated and maleic acid (MA) crosslinked polyvinyl alcohol (PVA)‐chitisan (CS) interpenetrating network (IPN) type nanocomposite membranes were prepared for dehydration of acetone by pervaporation (PV). FTIR, XRD, SEM, UV spectroscopy, mechanical properties, contact angle measurement, and DTA‐TGA were used to characterize these membranes. The effect of clay, CS, and MA on the flux and separation factor for water were statistically optimized by Box–Behnken design (BBD). Accordingly, the membrane prepared with 39.3 wt.% CS, 3 wt.% each of MA and NaMMT nanoclay showed a flux/separation factor of 0.176–0.733 kg/m2h/ 277–168 for the pervaporative dehydration of 99 wt.% acetone.Highlights IPN nanocomposite membranes were prepared from PVA, CS, and nano clay. Structure and properties of the IPNs were characterized. Synthesis parameters were optimized by BBD. Membranes showed high flux and water selectivity for acetone dehydration by PV.

Hybrid membranes of polyphenylsulfone/functionalized MXene nanosheets for the pervaporation dehydration of acetone and isopropyl alcohol

AbstractThe resistance of pervaporation (PV) dehydration membranes to organic solvents is of great importance. Polyphenylsulfone (PPSU) is known to resist most organic media; however, its acetone dehydration performance has not been evaluated yet. In the present study, MXene hydrophilic nanosheets with hydroxyl functional groups were synthesized and then incorporated in the PPSU membrane to prepare the PPSU/MXene PV membrane for the first time. The prepared membranes were used in the dehydration of acetone/water and isopropyl alcohol (IPA)/water. By comparing the attenuated total reflectance Fourier transform infrared spectroscopy spectra of the pure membrane and the nanocomposite membrane, the incorporation of hydroxyl functional groups into PPSU via MXene loading was confirmed. MXene improved the hydrophilicity and tensile properties of the membrane. The separation factor in acetone dehydration dropped with MXene incorporation up to 1 wt% and then increased with further MXene loading; however, it stayed almost unchanged in IPA dehydration with adding 0.5, 1, and 1.5 wt% MXene to the membrane. Incorporating 1 wt% MXene, the pervaporation separation index (PSI) was improved by 5.8 times in acetone dehydration and 9.7 times in IPA dehydration. The PPSU/1 wt% MXene membrane provided a remarkably higher separation factor (261 vs. 136) and PSI (99 vs. 58 kg/m2h) in acetone dehydration than in IPA dehydration; however, total flux was slightly lower in acetone dehydration (0.38 vs. 0.43 kg/m2h). This study implies that PPSU/MXene is a promising membrane material for the PV dehydration of organics.Highlights MXene hydrophilic nanosheets were synthesized. The synthesized MXene was loaded into the polyphenylsulfone membrane. PPSU/MXene membranes were used in pervaporation dehydration. MXene improved the hydrophilicity and tensile properties of the membrane. PPSU/MXene is a promising membrane material for PV dehydration of organics.

An improved plastination method for strengthening bamboo culms, without compromising biodegradability

Biomaterials are increasingly being designed and adapted to a wide range of structural applications, owing to their superior mechanical property-to-weight ratios, low cost, biodegradability, and CO2 capture. Bamboo, specifically, has an interesting anatomy with long tube-like vessels present in its microstructure, which can be exploited to improve its mechanical properties for structural applications. By filling these vessels with a resin, e.g. an applied external loading would be better distributed in the structure. One recent method of impregnating the bamboo is plastination, which was originally developed for preserving human remains. However, the original plastination process was found to be slow for bamboo impregnation application, while being also rather complicated/methodical for industrial adaptation. Accordingly, in this study, an improved plastination method was developed that is 40% faster and simpler than the original method. It also resulted in a 400% increase in open-vessel impregnation, as revealed by Micro-X-ray Computed Tomography imaging. The improved method involves three steps: acetone dehydration at room temperature, forced polymer impregnation with a single pressure drop to − 23 inHg, and polymer curing at 130 °C for 20 min. Bamboo plastinated using the new method was 60% stronger flexurally, while maintaining the same modulus of elasticity, as compared to the virgin bamboo. Most critically, it also maintained its biodegradability from cellulolytic enzymes after plastination, as measured by a respirometric technique. Fourier transform infrared-attenuated total reflection, and thermogravimetric analyses were conducted and showed that the plastinated bamboo’s functional groups were not altered significantly during the process, possibly explaining the biodegradability. Finally, using cone calorimetry, plastinated bamboo showed a faster ignition time, due to the addition of silicone, but a lower carbon monoxide yield. These results are deemed as a promising step forward for further improvement and application of this highly abundant natural fiber in engineering structures.

Evaluation of preservation protocols for oxygen‐sensitive minerals within laminated aquatic sediments

AbstractLaminated sediments can record seasonal changes in sedimentation of material from anoxic waters, including minerals of the redox‐sensitive elements Fe, Mn, and S that form under varying oxygen levels, mineral saturation conditions, and from microbial metabolism. However, preserving the oxygen‐sensitive minerals for identification is challenging when preservation of the spatial arrangement of laminae is also required. In this study, we compare methods for embedding sedimentary materials from anoxic waters and sediments from Brownie Lake, Minnesota, USA for analysis of the speciation for Fe, Mn, and S using synchrotron‐based X‐ray absorption near edge spectroscopy (XANES). We found that acetone dehydration and resin replacement in a 100% N2 glovebox successfully preserved the speciation of Fe and Mn minerals within laminated sediments. However, acetone removed some sulfur species from sediments, and epoxies contained sulfur species, which challenged identification of native sulfur species. Results from this study will aid researchers who are interested in spatial analysis of oxygen sensitive sediments, soils, or microbial mats in choosing a preservation method.

HISTOLOGICAL AND MORPHOLOGICAL CHANGES IN THE LYMPHOID STRUCTURES OF THE GASTRIC MUCOUS MEMBRANE IN WHITE RATS WITH THE ADMINISTRATION OF SODIUM GLUTAMATE.

The aim: To determine the histological and morphological changes of the lymphoid structures of the stomach in male rats under the influence of oral sodium glutamate at the rate of 15 mg/kg of body weight. Materials and methods: The scientific experiment was performed on 20 white non-linear male rats of reproductive age (4-5 months). The experimental animals were divided into two groups (10 rats in each group), which were orally received monosodium glutamate at a dose of 15 mg/kg body weight every day. We studied the effect of 2 and 4 weekly administration of monosodium glutamate at a dose of 15 mg/kg body weight, respectively, in the I and II groups of experimental animals (depending on the week of their decapitation). Rats of the control groups (n=10) were injected with a placebo for 2 and 4 weeks, namely 0.5 ml of dechlorinated tap water at room temperature. Intact control animals were also divided into two groups, 5 rats each, depending on the week of decapitation: respectively, III group - decapitation on the 2nd week of the experiment; IV group - decapitation on the 4th week of the experiment. After the experiments were completed, animals were decapitated under light ether anesthesia. According to the purpose of the study, pieces of rat stomach measuring 1.0 x 1.0 cm were taken from the front wall of the bottom of the stomach near the great curvature, cardiac and portal parts of the organ. Histological preparations were examined using a MICROmed SEO SСAN light microscope and a Vision CCD Camera. Morphometric studies were carried out according to the method of S. B. Stefanov, using grids No. 3/16. For electron microscopic examination, pieces of the stomach wall of rats were fixed in a 2.5% solution of glutaraldehyde in a 0.1 M phosphate buffer (pH 7.2-7.4) with subsequent fixation in a 2.0% solution of osmium tetroxide. After dehydration in alcohols and acetone, the material was embedded in eponaraldite. Sections were made on an LKB-8800-III ultramicrotome and studied using a JEM - 100-V microscope. To study the structural components of the lymphoid formations of the mucous membrane of different parts of the stomach of rats, semi-thin sections were made for the purpose of sharpening the blocks, which were stained with methylene blue. Results: The analysis of the obtained data of the conducted experiment indicates that the administration of monosodium glutamate in a dose of 15 mg/kg of body weight to rats already after 14 days leads to an increase in the density and size of the lymphoid structures of the GMM. The number of immunocompetent cells between the fundus of the gastric glands and the muscle plate increases in the diffuse lymphoid tissue of the gastrointestinal tract of rats in all its parts, both in the I and II groups of experimental animals. These changes are most pronounced in the cardiac and portal parts of the stomach. In both groups of experimental animals, the migration of interepithelial lymphocytes, macrophages, plasma cells, and tissue basophils to the surface epithelium increases. In both groups of experimental animals (and the II group of rats), lymphoid nodules and lymphoid pre-nodules of the gastric mucous membrane (GMM) are located between the bottom of the gastric glands and the muscular plate of the GMM. A gradual increase of medium lymphocytes in the GMM was established both in animals of I and II groups, while large lymphocytes increased in almost the same amount in experimental animals of both groups. Similar changes occur in the characteristics of the number of plasma cells, macrophages and tissue basophils in the lymphoid pre-nodules of GMM. Conclusions: Administering monosodium glutamate to rats at a dose of 15 mg/kg of body weight for 2 weeks leads to an increase in the density and size of lymphoid structures of the mucous membrane in all parts of the stomach with a predominant increase in the number of immunocompetent cells between the bottom of the gastric glands and the muscle plate. At the same time, more pronounced changes were found in the number of small lymphocytes, which tend to decrease by the 2nd week of the experiment, and vice versa - their density increases by the 4th week of monosodium glutamate administration.

Studies on preservation of gross pathological cardiac lesions by Thermocol plastination

Demonstration of gross lesions for educational purposes is often based on wet specimens, preserved in formalin, that emit hazardous formaldehyde vapors. This study is a pioneering attempt to plastinate pathological lesions in animal tissues using the economical Thermocol instead of costly resins, viz. silicon, epoxy and polypropylene. Six bovine heart samples, showing pathological lesions, were fixed with 5% formol saline, followed by dehydration in pure acetone, and impregnation with 15% Thermocol in organic solvent. Finally, curing of specimens was undertaken using Touchwood. Three gross lesions of the heart, viz. myocardial cyst, fibrinous pericarditis and endocardial/ epicardial hemorrhages, were plastinated in the present study. The myocardial cyst could be fixed in seven days; the fibrinous pericarditis could be fixed in 10 days, whereas hemorrhages required 15 days for fixation. The heart samples were impregnated by 44-48 days. The color of the lesions became darker and prominent in the plastinated hearts. There was no change in the texture of the tissues due to plastination, whereas the consistency of the heart became harder compared to fresh heart tissue. There was an significant reduction in mean mass (42.95%) and mean volume (40%) in the plastinated specimens. The Thermocol plastinated specimens were non-toxic, dry, easy to handle, odourless and durable, without the disadvantages of traditional formaldehyde preservation.

Fat Removal during Acetone Dehydration and Defatting Phases of Plastination

Fat Removal during Acetone Dehydration and Defatting Phases of Plastination

Fast acetone tissue processing of human organs provides tissue characteristics equal to conventional processing

ABSTRACT Routine preparation of paraffin embedded tissue for histopathological diagnosis, here termed conventional histological technique (CT), whether performed manually or using an automated system, requires approximately 12 h. We developed earlier a rapid acetone dehydration technique (AT) for processing biopsies of nervous tissue that meets requirements for preserving tissue morphology and staining properties, and reduces processing time to 3.3 h. We compared the morphology and staining properties of human organ biopsies including adrenal gland, liver, ovary, pancreas, prostate, testis and thyroid prepared using both AT and CT. Following fixation with 10% formaldehyde and processing by either AT or CT, sections were stained using routine and special staining, and immunohistochemical methods. We evaluated nuclear and cytoplasmic staining, staining intensity, sharpness of images and presence of artifacts such as cracking and folding. AT preserved the morphology and staining properties of the tissues as well as CT. Consequently, the rapid AT procedure is a promising alternative technique for tissue processing.

Nondestructive 3D Imaging and Quantification of Hydrated Biofilm-Sediment Aggregates Using X-ray Microcomputed Tomography.

Biofilm-sediment aggregate (BSA) contains a high water content, either within internal pores and channels or bound by extracellular polymeric substances (EPS) forming a highly hydrated biofilm matrix. Desiccation of BSAs alters the biofilm morphology and thus the physical characteristics of porous media, such as the binding matrix within BSA and internal pore geometry. Observing BSAs in their naturally hydrated form is essential but hampered due to the lack of techniques for imaging and discerning hydrated materials. Generally, imagery techniques (scanning electron microscopy (SEM), transmission electron microscopy (TEM), and focused ion beam nanotomography (FIB-nt)) involve the desiccation of BSAs (freeze-drying or acetone dehydration) or prevent differentiation between BSA components such as inorganic particles and pore water (confocal laser scanning microscopic (CLSM)). Here, we propose a novel methodology that simultaneously achieves the 3D visualization and quantification of BSAs and their components in their hydrated form at a submicron resolution using X-ray microcomputed tomography (μ-CT). It enables the high-resolution detection of comparable morphology of multiphase components within a hydrated aggregate: each single inorganic particle and the hydrated biofilm matrix. This allows the estimation of aggregate density and the illustration of biofilm-sediment binding matrix. This information provides valuable insights into investigations of the transport of BSAs and aggregate-associated sediment particles, contaminants (such as microplastics), organic carbon, and their impacts on aquatic biogeochemical cycling.

Palladium particle recovery from nitrile butadiene rubber dissolved in acetone through precipitation of poly(2-(dimethylamino)ethyl methacrylate)

Acrylonitrile butadiene rubber (NBR) has been used in the automotive industry. To change the strength of NBR, the double bond in NBR can be converted to a single bond using palladium particles immobilized on a support as a catalyst. During this catalytic reaction, palladium particles might leak into the solution. In this study, to recover palladium particles from highly concentrated NBR acetone solution, poly(2-(dimethylamino)ethyl methacrylate) (poly(DMAEMA)) solution was added to the palladium-containing solution. The amino group of poly(DMAEMA) captured palladium particles and poly(DMAEMA) shrunk by dehydration in acetone, resulting in rapid precipitation of poly(DMAEMA) complexed with palladium particles. The percentage of recovered palladium particles after 1 h was 60%. By immersing the complex in HNO3 solution including thiourea, 90% of the recovered palladium was eluted from the precipitated poly(DMAEMA).

P84 polyimide membranes modified by a tripodal amine for enhanced pervaporation dehydration of acetone

In this work we have fabricated P84 asymmetrical flat sheet membranes with a sponge-like structure by carefully formulating the polymer dope, followed by crosslinking the P84 membranes with a tripodal amine (tris(2-aminoethyl)amine (TAEA)) in a methanol solution, combined with heat treatment. The separation performances for acetone dehydration as functions of dope formulation, TAEA crosslinking time and post-annealing duration were further investigated and optimized by using the Taguchi statistical method. The membrane with the best pervaporation performance possessed a high separation factor of 983 with a reasonable flux of 0.658kgm−2h−1. FESEM, FTIR and XPS were employed to elucidate the crosslinking mechanisms and explain the evolution of physicochemical properties and chemistry–performance relationship. A benchmark comparison indicates that the newly developed P84/TAEA crosslinked membrane has good separation performance for acetone dehydration.

Superporous Hydrogel Composites of Acrylamide Using Starch-silicone Dioxide Coprecipitate as Composite Agent

Aim: Present study includes the development and evaluation of superporous hydrogel composites of acrylamide using starch silicone dioxide coprecipitate (SSC) as composite agent. Methodology: Gas blowing method was used for synthesis of superporous hydrogels. Different ingredients were mixed in specified amount in test tube and foaming agent was added at last. Simultaneous foaming and gelation lead to formation of porous hydrogel networks. Effect of different treatments (acetone dehydration and simulated gastric fluid (SGF) treatment) and drying conditions on the porous structure was evaluated. The prepared superporous hydrogels were evaluated for density, porosity, equilibrium swelling ratio, equilibrium swelling time, mechanical strength, scanning electron microscopy studies. The pure drug (Verapamil Hydrochloride) mixed with Carbopol 934 (1:0.5 and 1:1 ratio) was loaded into the selected batches of SPHC using in situ method of drug loading Original Research Article British Journal of Pharmaceutical Research, 4(3): 338-351, 2014 339 (drug added directly into the reaction mixture). The in vitro drug release was carried out using USP II dissolution apparatus. Results: Acetone dehydrated superporous hydrogel composites were observed as better floating devices due to least density and maximum porosity values. Maximum swelling ratio was found in case of oven dried conventional superporous hydrogel and superporous hydrogel composites with equilibrium swelling time of more than 25 min. On the other hand, acetone dehydrated SPH showed less equilibrium swelling ratio with equilibrium swelling time of 5-10 min. Minimum swelling ratio was observed in case of SGF treated hydrogels with equilibrium swelling time of 15-19 min. Mechanical strength was improved by addition of starch silicone dioxide coprecipitate as composite agent. SGF treatment also leads to enhanced mechanical strengthbut compromised swelling characteristics. SEM images showed uniformity in pore structure in case of acetone dehydrated hydrogels. Acetone dehydrated SPHC showed sustained drug release behavior with 71.14% and 57.84% of verapamil released in 12 h in the batches with Drug: Carbopol 934ratio of (1:0.5 and 1:1) respectively. Conclusion: Acetone dehydrated SPHC were found to be promising formulations with sufficient swelling and mechanical properties for achieving sustained drug delivery.

ULTRASTRUCTURAL STUDY OF BALANTIDIUM POLYVACUOLUM LI, 1963 (CLASS: LITOSTOMATEA) THAT INHABITS IN XENOCYPRINAE FISH

Balantidium polyvacuolum Li,1963,an obligatory intestinal symbiont of Xenocyprinae fish,mainly inhabits in the luminal contents of the middle and hindgut.Though the description and some revisions are given at both light and scanning electronic microscopic levels,the morphological data are still incomplete since fine structural data with taxonomic values are still unavailable.This study examined the ultrastructural anatomy of this Chinese balantidium that inhabits in the intestines of Xenocypris davidi collected from the Jialing River in Sichuan province during fish parasite surveys in August 2011.All fish samples were dissected,and intestines were cut to collect the luminal contents into petridishes for further examination with the aid of a dissecting microscope.The luminal contents of the hindgut containing numerous B.polyvacuolum were selected and fixed directly in 2.5% glutaraldehyde in 0.2 M phosphate buffered saline(PBS,PH 7.4) for 2h at 4 ℃,then postfixed in 1%(v/v) osmium tetroxide in PBS for 2h at 4 ℃,this step was followed by a series of dehydration in acetone and embedded in Araldite.Ultrathin sections were cut on a Leica Ultracut R ultramicrotome,stained with uranyl acetate and lead citrate before being observed in a Philips Tecnai G2 20 Transmission Electron Microscope(Netherlands).Its somatic cortex,vestibulum,nuclei,cytoplasmic organelles and the centroventral concave platelet were well described here.Our results indicated that both somatic cortex and vestibulum were composed of pellicle(the outermost cell membranes,pellicular alveoli and the layer of microtubules) and infraciliature(kinetosomes and associated fibrils such as kinetodesmal fibril,postciliary microtubules,transverse microtubules and nematodesmata).However,the nematodesmata of vestibular kinetids were much longer than those of somatic kinetids and usually extended deeply into the endoplasm.As for the nuclei,the macronucleus was club-shaped with several nucleoli and heterochromatin occupying the karyoplasm,whereas the spherical micronucleus was homoeomerous with diffuse chromatin distributed over the karyoplasm.In addition,large amounts of amylopectin granules were observed within cytoplasm of the centroventral concave platelet.We suspected that this region may act as a storage pool of amylose to provide energy for the organism.Besides,the components of the cortex were compared among the related Balantidium species and their possible functions were also discussed.

Decorin content and near infrared spectroscopy analysis of dried collagenous biomaterial samples.

The efficient removal of proteoglycans, such as decorin, from the hide when processing it to leather by traditional means is generally acceptable and beneficial for leather quality, especially for softness and flexibility. A patented waterless or acetone dehydration method that can generate a product similar to leather called Dried Collagenous Biomaterial (known as BCD) was developed but has no effect on decorin removal efficiency. The Alcian Blue colorimetric technique was used to assay the sulfated glycosaminoglycan (sGAG) portion of decorin. The corresponding residual decorin content was correlated to the mechanical properties of the BCD samples and was comparable to the control leather made traditionally. The waterless dehydration and instantaneous chrome tanning process is a good eco-friendly alternative to transforming hides to leather because no additional effects were observed after examination using NIR spectroscopy and additional chemometric analysis.

Language-oriented rule-based reaction network generation and analysis: Applications of RING

Applications of RING in the generation and analysis of complex thermochemical reaction networks are presented. Automated generation and topological network analysis features in RING allow for: (a) constructing reaction networks exhaustively in a rule-based manner, (b) identifying dominant pathways in networks using estimates of kinetic parameters, (c) hypothesis and testing of mechanisms by comparing pathway results from RING with experimental data, and (d) predicting atom-efficient synthetic routes to valuable chemicals from known chemistries and commonly available chemicals. Case studies involving three chemical systems are used to demonstrate these features in RING: (a) acid-catalyzed propane aromatization, (b) glycerol and acetone dehydration on acid catalysts, and (c) C4–C9 mono-alcohols synthesis from C2 and C3 oxygenates on acid, base, and metal catalyzed chemistries. Through these case studies, we demonstrate that RING can be used to postulate mechanisms and predict likely products for a given system, thereby guiding experimentation and computational analysis.

A rapid, valid and inexpensive assay for measuring epiphyseal plates in mouse tibia

One of the most accurate indices of changes in somatic tissue growth rate in rodents is the width of tibial epiphyseal plates as unlike most mammals, rodent growth plates never ossify. Unfortunately, the original procedure to measure tibial epiphyseal plate width (TEPW) was developed for rats and yields poor results with mice. This paper demonstrates a simple method for silver staining growth plates that can be used to inexpensively and quickly measure the TEPW of mice. Poor visualization due to overstaining and the shattering of growth plates necessitated several revisions to the original protocol. These include exposing the growth plate prior to acetone dehydration, reducing the silver nitrate concentration from 2% to 1.5% and staining time from 2 min to 10 s and finally, the use of reflective light rather than transmissive light when imaging. The optimized protocol was then validated by generating an age-dependent TEPW growth curve that matched changes in tibia length. A total of 120 tibias were processed in a combined time of less than one day and for less than $30. By contrast, histological processing in the university’s core facility would have cost $1440 and taken approximately three weeks. Thus, the revised protocol is vastly more cost effective, reliable and can be performed considerably quicker with minimal training.

The Effects of Fixation and Dehydration on the Histological Quality of Undecalcified Murine Bone Specimens Embedded in Methylmethacrylate

Histological evaluation is a complex, multistep process culminating in tissue staining. All of the steps leading up to the staining affect the final quality, but too often the effects of these preparations are not given enough consideration. Fixatives in particular usually are chosen not for efficacy but for convenience and availability. This study attempts to create guidelines for selecting fixatives for bone tissue histological evaluation. We compared two of the most widely used fixatives, ethanol and formalin, in their use on mouse tibias embedded in methylmethacrylate and subsequently stained with toluidine blue, safranin O, or Von Kossa. Our results show that ethanol fixation (70%) and subsequent processing in methylmethacrylate gives better staining results for bone cell related elements than fixing in 10% neutral buffered formalin with the same processing and embedding techniques. Further we demonstrated than an additional acetone dehydration and clearing step allowed for even better visualization in bone specimens fixed with 70% ethanol. However, the additional acetone step did not enhance visualization in bone specimens fixed with 10% neutral buffered formalin. Finally, marrow elements were more easily visualized when fixed with formalin as opposed to ethanol. (The J Histotechnol 32(1):27–31, 2009)Submitted September 23, 2008; accepted with revisions January 24, 2009

Zinc Chloride Embalming Technique and Silicone Plastination

INTRODUCTION It is known that formol and fenol vapours are irritants to airways and eyes. Personal health of the technician and students and efficiency considerations led to the adaptation of the embalming technique 5 years ago. Since 2000, the anatomy institute has embalmed 150 cadavers using the adapted zinc chloride embalming technique. MATERIALS AND METHODS The embalming solution contains 10 litre Zinc Chloride® and 100 ml Arthyl®. Embalming starts with the injection of fluid through the femoral artery. A pump is fitted to the canule and the solution is pumped into the cadaver in four hours. Five months after embalming, a cadaver was dissected and several organs and tissues were removed and prepared for plastination using the S10® Silicone technique. RESULTS The joints of the cadavers are more flexible than the joints of the cadavers embalmed with formol and fenol, natural colours are preserved and odour is low. The microscopic morphology of tissues removed one year post mortem, is comparable to the microscopic morphology of specimens at the moment of embalming. The embalmed specimens were compatible with acetone dehydration for plastination. The plastinated specimens of the pharynx, foot, a section of the lower limb, two kidneys, spleen, liver, lung, knee, cerebrum, cerebellum, part of the chest wall, testis and two hand specimens, retained their natural colour and macroscopic morphology. CONCLUSION The zinc chloride embalmed cadavers are used for anatomical research and education. It is possible to plastinate specimens removed from a zinc chloride embalmed cadaver using the Silicone plastination technique.

Dehydration of Acetic Acid, Alcohols, and Acetone by Pervaporation Using Acrylonitrile‐Maleic Anhydride Copolymer Membrane

Pervaporative dehydration of acetic acid, ethyl alcohol, isopropyl alcohol, and acetone over the entire concentration range of 0–100 wt% is studied using acrylonitrile‐maleic anhydride copolymer membrane. The membrane exhibits reasonable performance with respect to both separation factor and permeance (11.0 and 279.4 g/m2.hr./bar, respectively, at 92 wt% feed conc. of water) for acetone dehydration. Dehydration performances of acetic acid and ethyl alcohol are comparable (permeance and separation factor of water for its mixture with acetic acid is 119.5 gm/m2.hr./bar and 2.4, respectively, while the same for its mixture with ethyl alcohol is 125.4 gm/m2.hr./bar and 2.5, respectively, at 50 wt% feed) over the whole concentration range. Isopropyl alcohol shows the best separation factor for water at very low alcohol concentration (8.7 at 2.5 wt% feed) with lowest permeance among the four systems of separations.