Isotonic Aqueous Solution Research Articles

Ультранизкочастотные осцилляции интенсивности люминесценции полимерной мембраны в водных растворах солей

The paper studies luminescence from the Nafion polymer membrane surface at its swelling in the isotonic aqueous solutions and bi-distilled water using the experimental photo luminescent spectroscopy. Liquid samples were preliminarily treated with the electric pulses with duration of 1 µs and amplitude of 0.1 V using antenna in the form of a flat capacitor. Experiments in photo luminescent spectroscopy were carried out 20 min after the electric pulse treatment. Typical luminescence intensity dependence on the membrane swelling time could be represented as the exponentially decreasing function. Characteristic decay time of the corresponding functions and stationary level of the membrane luminescence intensity depend on the electrical pulses repetition rate. The obtained dependencies could well be reproduced. However, dependence of the luminescence intensity at certain pulse repetition rates appears to be a random function, and the reproducibility is missing. It could be assumed that these stochastic effects are associated with exposure to random external force of the electromagnetic nature acting on the polymer membrane during swelling. Low-frequency pulsations of neutron stars or white dwarfs are the source of this random force according to the authors of the work. This effect is associated with depolarization during the low-frequency electromagnetic field scattering caused by the neutron stars pulsation. Depolarization effect arises due to scattering on long-living anisotropic clusters of nano-bubbles, which, in turn, are becoming anisotropic in the external field of a flat capacitor. Depolarized scattered radiation causes stochastic oscillations of the polymer fibers unwound into the bulk liquid. In this case, luminescence should also acquire the stochastic character taking into account the effect of resonant luminescence energy transfer from a donor to the luminescence acceptor

Changes in the T and B lymphocyte subset profiles upon treatment of patients with Graves’ disease with radioactive iodine

The aim of the present study was to evaluate the subpopulation profile of T and B lymphocytes, and their relationships during therapy of the patients with Graves’ disease (GD) treated by means of radioactive iodine. We have examined 36 women with verified diagnosis of GD. The contents of thyroid hormones were determined by immunoradiometric analysis. The levels of thyroid-stimulating hormone receptor autoantibodies (rTSH) were evaluated by enzyme-linked immunosorbent assay. On the basis of comprehensive pre-therapeutic examination, all patients were exposed to the fixed-activity therapy with radioactive iodine-131 at a dose of 400 to 700 MBq administered orally in isotonic aqueous solution of sodium iodide. 56 practically healthy women were examined as a control group. The phenotype of T and B cells in whole blood was studied by flow cytometry using direct immunofluorescence. It was shown that the patients, prior to treatment with radioactive iodine, had high levels of cellular functional activity, as determined by expression of CD25 antigen on T cells and CD23-antigen on B lymphocytes. Higher functional activity of the cells responsive for adaptive immunity in the patients with GD manifests in the presence of increased levels of autoantibodies to rTSH. By means of correlation analysis, we found that the patients with GD examined before the therapy had the thyroid status may determine the functional stimulation of T and B cells, thus increasing the levels of autoimmune processes. One month after radioiodine therapy (RIT), the GD patients, along with transient hyperthyroidism with increased concentration of autoantibodies to rTSH, showed a reduction of activated T lymphocyte contents (including T helpers and cytotoxic T cells) to control values. However, the level of cytotoxic T lymphocytes in the blood remained low, and the content of Treg cells was significantly increased in the patients. Decreased contents of B cells activated memory B cell to the control levels were found in patients with GD over 1 month after RIT when studying the phenotype of blood B lymphocytes. In this case, increased levels of naive B lymphocytes and B2 cells were detected, as well as decreased numbers of activated B1 lymphocytes. The observed changes in the subpopulation composition of T and B cells, and in their phenotype developed against the background of complete absence of relationships between the studied parameters, thus suggesting loss of thyroid control of immune processes and cooperative cell interaction during the development of the immune response. Generally, the phenotypic changes of T and B lymphocyte subsets in the blood of patients with GD through 1 month after treatment with radioactive iodine may reflect a trend for decreased functional activity of adaptive cellular immunity which may also account for inhibition of autoimmune processes.

Stochastic Ultralow-Frequency Oscillations of the Luminescence Intensity from the Surface of a Polymer Membrane Swelling in Aqueous Salt Solutions.

Photoluminescence from the surface of a Nafion polymer membrane upon swelling in isotonic aqueous solutions and Milli-Q water has been studied. Liquid samples were preliminarily processed by electric pulses with a duration of 1 μs and an amplitude of 0.1 V using an antenna in the form of a flat capacitor; experiments on photoluminescent spectroscopy were carried out 20 min after this treatment. A typical dependence of the luminescence intensity, I, on the swelling time, t, obeys an exponentially decaying function. The characteristic decay time of these functions and the stationary level of luminescence intensity depend on the repetition rate of electrical pulses, and the obtained dependences are well reproduced. It transpired that, at certain pulse repetition rates, the dependence, I(t), is a random function, and there is no reproducibility. Stochastic effects are associated with a random external force of an electromagnetic nature that acts on a polymer membrane during swelling. The source of this random force, in our opinion, is low-frequency pulsations of neutron stars or white dwarfs.

Long-Term Effect of Low-Frequency Electromagnetic Irradiation in Water and Isotonic Aqueous Solutions as Studied by Photoluminescence from Polymer Membrane.

The swelling of a polymer membrane NafionTM in deionized water and isotonic NaCl and Ringer’s solutions was studied by photoluminescent spectroscopy. According to our previous studies, the surface of this membrane could be considered as a model for a cellular surface. Liquid samples, in which the membrane was soaked, were subjected to preliminary electromagnetic treatment, which consisted of irradiating these samples with electric rectangular pulses of 1 µs duration using platinum electrodes immersed in the liquid. We used a series of pulses with a repetition rate of 11–125 Hz; the pulse amplitudes were equal to 100 and 500 mV. It turned out that at certain pulse repetition rates and their amplitudes, the characteristic swelling time of the polymer membrane significantly differs from the swelling time in untreated (reference) samples. At the same time, there is no effect for certain frequencies/pulse amplitudes. The time interval between electromagnetic treatment and measurements was about 20 min. Thus, in our experiments the effects associated with the long-term relaxation of liquids on the electromagnetic processing are manifested. The effect of long-term relaxation could be associated with a slight change in the geometric characteristics of bubston clusters during electromagnetic treatment.

3D-printed planar microfluidic device on oxyfluorinated PET-substrate

The paper proposes the material extrusion additive manufacturing (via filament fabrication (FFF)) of planar microfluidics devices on the surface-modified PET-substrates production. The transformation of PET-substrates’ morphological structure under the action of a multi-gas-phase modifying mixture significantly improves the wetting and the adhesion of the PLA-filament to them. A significant change in the chemical composition and nanorelief of PET substrates' surfaces as a result of processing with a gas mixture based on helium, nitrogen, fluorine and oxygen is confirmed experimentally by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and fourie-transform infra-red spectroscopy (FTIR). The twelve-fold increase in the adhesion of the filament (measured) and the two-fold difference in the free surface energy values (calculated) for the original and the modified PET-substrates were observed. The functional characteristics' variances were accompanied with an approximately ten-fold increase in the degrees of heterogeneity for the carbon and oxygen concentration distributions and with the two-fold changes in the localization region and the average amplitude of the corresponding morphological spectra. The significant increase in the rate of mass transfer of an isotonic aqueous solution of sodium chloride through the surface microchannels of the constructed planar microfluidics device confirms the considerable changes in wettability of the modified PET substrates’ surfaces.

A combined experimental and theoretical study of miconazole salts and cocrystals: crystal structures, DFT computations, formation thermodynamics and solubility improvement.

Experimental and theoretical screening of multi-component crystal forms of miconazole (MCL), an antifungal drug, with ten aliphatic dicarboxylic acids was performed. Seven multi-component molecular crystals were isolated and identified by different analytical techniques, including the powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TG), and solubility methods. The crystal structures of the MCL hemihydrate, two cocrystals with succinic ([MCL + SucAc] (2 : 1)) and fumaric acids ([MCL + FumAc] (2 : 1)) and one salt with maleic acid ([MCL + MleAc] (1 : 1)) were redetermined. The new cocrystal of MCL with adipic acid ([MCL + AdpAc] (2 : 1)) was investigated by single crystal X-ray diffractometry. It was found that the AdpAc molecule in the cocrystal has an unusual anticlinal conformation. The combination of periodic density functional theory (DFT) computations and quantum topology analysis confirmed the structure-directing role of the acid-imidazole heterosynthon for the considered crystals. The melting temperatures of all the studied multi-component crystals are between the values of the corresponding individual components except [MCL + MleAc] (1 : 1). A thermal analysis has shown that the thermodynamic and thermophysical characteristics of the considered two-component molecular crystals are strongly dependent both on specific interactions (presence of sites of donor-acceptor interactions and hydrogen bond formation) and on nonspecific interactions - molecule polarizability. Based on the sublimation thermodynamics database of molecular crystals, the standard sublimation thermodynamic functions of MCL were evaluated. The thermodynamic functions of multi-component crystal formation based on MCL were calculated and analyzed. Solubility experiments on the MCL multi-component crystals were carried out in isotonic aqueous buffer solutions at pH 1.2 and 6.8 and compared with the solubility of the MCL free base and its nitrate salt. It was found that the salt/cocrystal formation of MCL with dicarboxylic acids considerably increased the MCL solubility in pH 6.8 buffer. The biggest MCL solubility enhancement was observed in the [MCL + TartAc] (1 : 1) salt. The solubility value of MCL in the [MCL + TartAc] (1 : 1) salt is commensurate with the commercial MCL nitrate salt.

Characteristic Changes in the Density and Shear Viscosity of Human Blood Plasma with Varying Protein Concentration

The density and shear viscosity of human blood plasma and their dependence on the concentration of proteins (albumin, y-globulin, fibrinogen, etc.) entering the natural blood composition have been studied. The biomaterial concentration is varied by diluting the blood plasma with the isotonic aqueous solution. It is shown that a decrease in the biomaterial concentration down to 0.91 of its initial value leads to a drastic change in the plasma density and to a change in the character of the concentration dependence of the shear viscosity of blood plasma. A hypothesis is put forward that the observed changes in the density and shear viscosity result from the structural transformations induced by oligomerization processes; first of all, by the albumin dimerization. A conclusion is drawn that the introduced blood substitutes should not exceed 10% of the blood mass; otherwise, structural transformations of a biomaterial in blood plasma can be provoked.

Osmotic behaviour of human mesenchymal stem cells: Implications for cryopreservation.

Aimed at providing a contribution to the optimization of cryopreservation processes, the present work focuses on the osmotic behavior of human mesenchymal stem cells (hMSCs). Once isolated from the umbilical cord blood (UCB) of three different donors, hMSCs were characterized in terms of size distribution and their osmotic properties suitably evaluated through the exposure to hypertonic and isotonic aqueous solutions at three different temperatures. More specifically, inactive cell volume and cell permeability to water and di-methyl sulfoxide (DMSO) were measured, being cell size determined using impedance measurements under both equilibrium and dynamic conditions. Experimental findings indicate that positive cell volume excursions are limited by the apparent increase of inactive volume, which occurs during both the shrink-swell process following DMSO addition and the subsequent restoration of isotonic conditions in the presence of hypertonic solutions of impermeant or permeant solutes. Based on this evidence, hMSCs must be regarded as imperfect osmometers, and their osmotic behavior described within a scenario no longer compatible with the simple two-parameter model usually utilized in the literature. In this respect, the activation of mechano-sensitive ion-channels seemingly represents a reasonable hypothesis for rationalizing the observed osmotic behavior of hMSCs from UCB.

Emerging roles of liposomal bupivacaine in anesthesia practice.

Despite advances in drug technology and improvements in technology, including peripheral nerve catheters and ultrasound, postoperative pain is still a significant problem in the clinical setting worldwide. Postoperative pain can have a critical negative impact with regard to physiological consequences to the body and therefore, the role of liposomal bupivacaine as an extended release bupivacaine with approximately 72 h of duration may have far-reaching and significant impact in clinical practice. Liposomal bupivacaine has a DepoFoam multivesicular liposome technology with particle suspension in an isotonic aqueous solution and consists of tiny lipid-based particles, which contain discrete water-filled chambers dispersed through a lipid matrix. Other advantages include a reduction in opioid consumption, while not requiring a catheter or any other device, as well as easy dilution with saline. This review summarizes current research with this novel agent in postsurgical pain, and discusses potential roles in chronic pain states. Further studies are warranted for its use in epidural and intrathecal administration. Moreover, this review will explore the expansion of liposomal bupivacaine's current clinical role.

Tear fluid-eye drops compatibility assessment using surface tension

Objective: To evaluate the compatibility of commercially available eye drop surface tension with the tear film physiological range and to characterize commonly used ophthalmic excipients in terms of their surface activity under eye-biorelevant conditions.Significance: There are a number of quality requirements for the eye drops (e.g. tonicity, pH, viscosity, refractive index) that needs to comply with the physiological parameters of the eye surface. However, the adjustment of surface tension properties of the eye drops to the normal range of surface tension at the air/tear fluid interface (40–46 mN/m) has received rather less attention thus far. Yet, the surface tension at the air/tear fluid interface is of vital importance for the normal function of the eye surface.Methods: The surface tension compatibility of the isotonic aqueous solutions of commonly used ophthalmic excipients as well as 18 approved eye drops with the tear fluid have been evaluated using surface tension method.Results: Each ophthalmic ingredient including the preservatives, solubilizing agents and thickening agents can influence the surface tension of the final formulation. In case of complex ophthalmic formulations one should also consider the possible interactions among excipients and consequent impact on overall surface activity. Out of 18 evaluated eye drops, three samples were within, 12 samples were below and three samples were above the physiological range of the tear fluid surface tension.Conclusions: Our results provide a rationale for clinical studies aiming to assess the correlation between the eye drops surface tension and the tear film (in)stability.

Rapid determination of the identity of aqueous drug solutions

The stationary stability of giant heterophase clusters (GHCs) of water in samples of sodium chloride isotonic aqueous solutions from three manufacturers has been studied. The influence of the NaCl concentration on the relaxation kinetics of GHCs is established. A method for determining the identity of aqueous drug solutions without violating the integrity of the packaging is developed.

Real-time monitoring of the heat of transfer of a homologous series of m-alkoxy phenols from isotonic aqueous solution to bacterial cells

Heats of dissolution of a homologous series of m-alkoxy phenols in an osmotically stable isotonic solution and in the same media containing a suspension of Escherichia coli cells were obtained by a differential heat conduction batch calorimeter at 298 K. The calorimetric curves show an initial rapid endothermic dissolution of the solute, followed by an exothermic process. From the heats of solution, the heat of transfer (Qtrs) of these compounds from the aqueous solution to the cells was calculated. The heat of transfer is exothermic and increases with the hydrophobicity of the compounds due to the biological consequences of the interaction process with the lipidic phase.

Study of multiple solid-phase microextraction combined off-line with high performance liquid chromatography: Application in the analysis of pharmaceuticals in urine

Solid-phase microextraction (SPME) was applied to the extraction of five common pharmaceuticals: quinine, naproxen, haloperidol, ciprofloxacin and paclitaxel. SPME combined off-line with HPLC analysis was studied independently for each analyte. Polydimethylsiloxane and polyacrylate fibres were used for the direct immersion SPME from isotonic analyte solutions and spiked human urine samples. Analyte desorption occurred in HPLC autosampler inserts containing 200 μL of methanol; next 80 μL of the resulting solution were injected on the HPLC. Extraction optimisation involved parameters such as addition of salts, pH value and saturation time. The pharmaceuticals were assayed independently by multiple extraction from isotonic aqueous solutions and urine samples. A protocol of multiple SPME provided higher yields for the four of the five examined analytes. The results showed the potential of using multiple SPME (but also single SPME) combined off-line to HPLC in bio-pharmaceutical analysis.

Expulsion of allergen-containing materials from hydrated rye grass (Lolium perenne) pollen revealed by using immunogold field emission scanning and transmission electron microscopy

Background: Several studies demonstrated episodes of grass pollen–induced allergic asthma after heavy rainfalls. It has been hypothesized that these asthma attacks might be due to the release of respirable allergen-bearing particles from pollen cytoplasm. Objective: In this study we investigated the release mechanism of the most potent and frequently recognized grass pollen allergens, group 1 and group 5, from freshly harvested and subsequently hydrated rye grass pollen at the ultrastructural level. Methods: Rabbit antisera against purified recombinant group 1 and group 5 allergens were used to investigate, by using field emission scanning and transmission immunogold electron microscopy, the allergen release from rye grass pollen grains into isotonic aqueous solutions or water. Results: Pollen grains exposed to isotonic aqueous solutions remained intact and released allergens by means of diffusion. However, pollen grains hydrated in distilled water or rainwater expelled starch grains and cytoplasmic debris of respirable size. Group 1 and group 5 allergens were observed on and within these materials. Conclusions: Exposure of rye grass pollen to water leads to an expulsion of subcellular allergen-containing pollen components of respirable size. Our ultrastructural data thus support the idea that this release of allergen-containing respirable pollen materials may be a cause of asthma attacks after heavy rainfalls. (J Allergy Clin Immunol 2000;105:1140-5.)

Power Doppler and B-mode sonography of nasal mucosa

Anatomy and perfusion of the nasal septum and inferior turbinate mucosa can be visualized with B-mode and power-Doppler ultrasound. The transducer is placed externally on the nasal ala parallel to the pyriform crest and directed towards the head of the inferior turbinate of the opposite side. An individually prepared dental splint keeps the transducer in position and allows assessment of dynamic changes in mucosal swelling and perfusion. Perfusion changes are evaluated by computerized quantification of power-Doppler color pixels. Coupling of ultrasound across the nasal lumen is achieved by introducing gel into one nasal vestibule and flooding the anterior nasal cavity of the side to be visualized with isotonic aqueous solutions. Perfusion could be visualized in 23 of 30 subjects, while B-mode sonographic anatomy was visualized in 16 subjects. The effect of isotonic saline solution (10 healthy subjects), naphazoline (10 patients with chronic nasal obstruction) and allergen extracts (10 patients with allergic rhinitis) on mucosal perfusion and swelling was studied. Isotonic saline solution induced a maximum drop in power-Doppler color pixel density by 10% and a maximum increase by 27%, but no change was seen in mucosal swelling. Naphazoline induced a 10-57% decrease in power-Doppler pixel density and decongestion of the inferior turbinate and septum mucosa by 17-43% and 4-27%, respectively. Allergen extracts induced an increase in power-Doppler color pixel density by 24-181% and an increase in mucosal thickness by 4-31%. These preliminary results encourage further studies of nasal mucosal perfusion changes using power-Doppler sonography after pharmacologic and allergen provocations.

Is the sugar intestinal permeability test a reliable investigation for coeliac disease screening?

The lactulose/mannitol (L/M) intestinal permeability test is a simple, non-invasive screening test for coeliac disease. The reliability of the L/M test has so far only been tested in selected groups of patients with coeliac disease. To evaluate the reliability of the L/M test in a group of patients with coeliac disease who had been diagnosed during mass serological screening of the general population. Twenty nine patients with coeliac disease detected by screening and 54 age matched coeliac disease free controls aged 11-15 years underwent an L/M test with 5 g lactulose and 2 g mannitol in isotonic aqueous solution. Urinary sugars were measured by high performance liquid chromatography. The median % urinary recovery of lactulose (lactulose UR) was significantly higher in patients with coeliac disease than in controls (0.63 v 0.18, p < 0.001). The mean mannitol % UR was lower in patients with coeliac disease than in controls (17.6 v 18.5) but the difference was not significant. The median urinary L%/M% ratio was significantly higher in patients with coeliac disease than in controls (0.038 v 0.014, p < 0.001). However, 16 of the 29 patients with coeliac disease showed an L%/M% ratio within normal limits (< 0.044). The L/M intestinal permeability test is not a valuable tool for screening of coeliac disease in the general population. The pattern of the urinary probe recovery suggests that many patients with coeliac disease could remain symptomless because the extent of their intestinal mucosal damage is small ("short" coeliac disease).

Cystic fibrosis: bile secretion.

Bile is an isotonic aqueous solution of bile acids, cholesterol, phospholipids, bile pigments and inorganic electrolytes. It is secreted by the hepatocytes into the bile canaliculi and modified in the bile ductules or ducts. The three main processes identified in the generation of bile flow are: 1. Active transport of bile acids from blood into bile canaliculi. This is responsible of the bile acid-dependent canalicular bile flow. Coupling between water flow and bile acid secretion is probably effected mainly through an osmotic mechanism. There is evidence that water flows (at least in part) through the interhepatocytic junctions. The bile acid-dependent flow accounts for 30 to 60% of spontaneous basal bile flow. 2. A canalicular, bile acid-independent secretion, probably due to transport into bile of organic solutes (glutathione) and inorganic electrolytes. This fraction of bile flow is stimulated by phenobarbital. It represents 30 to 60% of basal bile flow. Normal canalicular bile flow also depends on the integrity of intracellular cytoskeletal organelles, mostly microfilaments. 3. Reabsorption and secretion of fluid and inorganic electrolytes by the ductules and ducts. Secretion chiefly occurs in response to secretin and represents 30% of basal bile flow. Although several ion transport systems have been identified on the biliary epithelial cells (in particular a Na+/H+ exchange, a Na+:HCO3- symport and a CI-/HCO3- exchange), the cellular mechanism of secretion is not known. Abnormalities of bile duct function may account for the liver disease of cystic fibrosis, but these abnormalities have not been characterized.

Microencapsulation of mammalian cells in a HEMA‐MMA copolymer: Effects on capsule morphology and permeability

A new process for preparing uniform microcapsules with a hydroxyethyl methacrylate-methyl methacrylate copolymer (HEMA-MMA) has been devised. Capsule diameters were 900-1000 microns in diameter, (+/- 10-20 microns, +/- SD) depending on the precipitation conditions. The process involved the coextrusion of polymer solution (in PEG 200) and the mammalian cell suspension (here erythrocytes) through a needle assembly which is submerged in a layer of hexadecane which is in turn sitting above a stirred isotonic aqueous solution in a volumetric flask. The needle is repeatedly withdrawn from the hexadecane overlayer shearing a droplet from the needle tip which falls into the water, where the solvent is extracted to precipitate the polymer around the cells to yield the capsules. The morphology of the capsule wall was altered by changing the precipitation bath from phosphate buffered saline (PBS) to 0.3 M glycerol. This resulted in greater macroporosity in the wall, presumably because of the faster precipitation due to the higher solvent/precipitant compatibility with 0.3 M glycerol. The permeability to a series of test solutes (glucose, inulin, albumin, and alcohol dehydrogenase, ADH) increased by a factor of approximately 2, presumably because of the increased macroporosity. Addition of 15% water to the polymer solvent enhanced the macroporosity, presumably by bringing the system closer to the cloud point; however, there was no corresponding increase in permeability. There was a significant decrease in permeability between that of albumin (approximately 69,000 D) and ADH (approximately 150,000 D) suggesting that the molecular weight cut-off of these capsules was on the order of 100,000 D as desired. This process is now being evaluated for the encapsulation of pancreatic islets and other cells of potential clinical interest.

Increased sensitivity to complement of megakaryocyte progenitors in paroxysmal nocturnal haemoglobinuria

Paroxysmal nocturnal haemoglobinuria (PNH) is a haemolytic disorder characterized by an increased sensitivity of peripheral blood cells including platelets to the lytic action of complement (C'). Previous studies have demonstrated that in PNH bone marrow erythroid colony and burst forming units, as well as granulocytic-monocytic colony forming units, have an increased sensitivity to complement-induced injury as compared with normal erythroid and myeloid progenitors. The purpose of this study was to investigate the effect of complement on PNH and normal marrow megakaryocytic progenitors (CFU-M). Bone marrow non-adherent and T-cell depleted light density mononuclear cells from three patients with PNH and six normal volunteers were exposed to fresh or heat-inactivated AB human serum in the presence of medium or isotonic aqueous sucrose solution for 30 min at 37 degrees C. After being washed the cells were assayed for CFU-M by the plasma clot method in a complement free medium containing 6% medium conditioned by T-lymphocytes stimulated by phytohaemagglutinin. The number of megakaryocytic colonies grown from PNH marrow cells exposed to isotonic sucrose and C' was reduced to one third of those grown from PNH cells exposed to isotonic sucrose and heat-inactivated C', or to medium with and without C'. In contrast, the number of megakaryocytic colonies grown from normal marrow cells exposed to isotonic sucrose and C' was unchanged. These findings indicate that PNH marrow CFU-M express an increased sensitivity to C'-mediated injury similar to that detected on PNH-erythrocytes by the sucrose haemolysis test, and support the hypothesis that the PNH defect is expressed at the level of pluripotent haematopoietic stem cell.

Microcalorimetric measurement of the enthalpies of transfer of a series of ortho- and para-alkoxyphenols from water to octan-1-ol and from isotonic solution to escherichia coli cells

Enthalpies of transfer for ortho- and para-alkoxyphenols from aqueous isotonic solution to non-growing Escherichia coli are reported. The values are compared, for ortho-alkoxyphenols, to ΔtrsH for transfer from water to octan-1-ol. The values for both ortho- and para-homologues show breaks in ΔtrsH(isotonic aqueous solution to cells) values as a function of carbon number in the side chain = 4. The differences in ΔtrsH values for ortho-, meta-(published previously) and para-alkoxyphenols are compared.