Exercise and the brain: a mechanical model for pulsation on flow of cerebrospinal fluid

Exchange of molecules between cerebrospinal fluid (CSF) and brain cells contributes to brain function and protection from dementia, but the route by which CSF is brought close enough to the neural tissue to be exchanged by extracellular diffusion is not clear. Exogenous molecules injected into CSF are carried along channels outside arteries and reach the basement lamina that surrounds the dense capillary network. Transport of solutes by diffusion along the basement lamina, a gel of macromolcules about 100 nm thick, would be too slow; bulk flow in a static geometry would require unphysiologically high pressures. However, it is known that the pulsation of blood aids transport of CSF, and we hypothesized that this is because the pulsation intermittently squeezes the pericapillary lamina. In a primitive mimicry, we have tested whether intermittent squeezing increases flow through an agar gel. In all but one of 216 tests, pulsation caused a reversible increase, sometimes by a factor of 100 or more. The enhancement was greatest for frequencies 5-11 Hz and, over the tested range of pressure heads (20 - 50 cmH2O), was greatest for the lowest pressure. The results suggest one reason why exercise slows the aging of the brain.

First study of Brucella ovis antibodies in purebred sheep flocks in the State of Parana, Brazil

ABSTRACT Brucella ovis, a non-zoonotic species, is the etiological agent of ovine brucellosis, an infectious disease of clinical or subclinical occurrence in sheep flocks. Until then, there is no serological study of anti-Brucella ovis antibodies in purebred sheep herds. This study aimed to determine the presence of anti-Brucella ovis antibodies in purebred sheep flocks with breeding purposes from Parana State. Blood samples from 728 animals, of which 563 were females and 165 males, between 8 and 56 months of age from the six major sheep producing mesoregions of Parana, were submitted to detection of anti-Brucella ovis antibodies by the Agar Gel Immunodiffusion technique using an antigen from the bacteria Brucella ovis (Reo 198). The results indicate the presence of this disease in purebred sheep from Parana State in a low occurrence of 0.27% (2/728). The only two positive animals were rams, Santa Inês breed, from the same flock in the East Center region of Parana, without clinical disease. In conclusion, Brucella ovis is present in purebred sheep in Parana State, Brazil, and this low occurrence may have occurred due to rigorous breeding systems that may contribute to reduce the transmission of this disease.

Signal-to-noise ratio uniformity and stability of agar gel phantom with iron (III) oxide as relaxation modifier

Background Agar has been commonly used as one of the materials to fabricate magnetic resonance imaging phantoms in the past few decades. In this study, eleven agar gel phantoms with different iron (III) oxide (Fe2O3) masses were prepared. This study was aimed to evaluate the signal-to-noise ratio (SNR) uniformity and stability of agar gel phantoms with and without the addition of Fe2O3 at two different time points (TPs). Fe2O3 powder was used as a relaxation modifier to manipulate and produce various SNR, T1 and T2 values. These phantoms were scanned using turbo spin echo pulse sequence to produce T1- and T2-measurement images. The SNR was then computed by plotting 1, 3 and 25 regions of interest on the images using ImageJ software. The T1 and T2 relaxation equations were then fitted to the experimental results of SNR versus TR and SNR versus TE curves for the determination of saturation (SNRo), T1 and T2 values. Results The results demonstrated that the agar gel phantoms were able to maintain SNR uniformity but not SNR stability after 4 weeks of phantom preparation. The change in the water content and microstructure of the phantoms have no significant effect on T2 relaxation but on T1 relaxation. The T1 and T2 of the agar gel phantoms were minimally affected although there was a systemic increase in the content of the Fe2O3 powder. Conclusions It can be concluded that the agar gel phantoms exhibited the characteristics of SNR uniformity, but they showed instability of SNR at TP2. The Fe2O3 in powder form is not an effective relaxation modifier to reduce the T1 and T2 when it is introduced into the agar gel phantoms. Dissolved nanosized particles should be the focus of future studies.

Optimization of the Composition of the Ointment with Phytoecdysteroids Serpisten

Introduction. Phytoecdysteroids are a group of natural compounds related in structure and physiological effect to ecdysone - the hormone of insect molting. Phytoecdisteroids have been found to have an antiflammatory effect, which suggests that they have regenerative properties. The development of a soft dosage form containing phytoecdysteroids is of interest.Aim. Improvement of ointment compositions with phytoecdysteroids by optimizing the composition of base adjuvants.Materials and methods. As an active substance was used Serpisten, containing the sum of phytoecdysteroids, the main of which is 20-hydroxyecdysone and obtained from the leaves of Serratulaecoronatae. Raw materials "Serpukhi crowned leaves" were registered by the Federal Service Rospotrebnadzor (Moscow) for the production of dietary supplements (Gr. No. 77.99.23.3.U.1922.3.08), substance Serpisten (Gr. No. 77.99.23.3.U.1923.3.08. TU 9369-002-15092611-2008). In work were used the excipients allowed for medical use: the monoglycerides distilled, T-2 emulsifier, tween 80, sodium - carboxymethylcellulose, polyvinyl alcohol, hydroxide of aluminum, aero forces, vaseline, oil vaseline, sunflower oil. Optimization of ointment auxiliary substances composition was carried out according to the Greco-Latin 4 x 4 square plan with repeated observations. The concentration of hydrogen ions from aqueous ointments was evaluated as process parameters; acid number; release of serpistene from ointment into agar gel, thermal stability of structure. The structural and mechanical properties of the optimal composition ointment composition were determined on a RV type REOTEST 2.1 rotary viscometer (RHEOTEST Medingen GmbH, Germany). Ointment Bepanten (GP Grenzach Produktions GmbH, Germany) was used as a comparison preparation.Results and discussion. During optimization of the composition of the diphilic ointment with serpistene, was found that the ratio of hydrophobic and hydrophilic phases should be 1 : 1, it is advisable to introduce into the ointment base an emulsifier T-2, aerosil and a mixture of vaseline and vaseline oil in the proportion of 1 : 1. As a result of the carried out studies on the optimization of ointment compositions, the following serpisten ointment composition is proposed: serpisten - 0.02; emulsifier T-2 - 3.0; aerosil - 3.0; vaseline - 23.0; vaseline oil - 23.0; ethyl alcohol 40 % - 1 ml; purified water to 100.0. Comparative analysis of effective viscosity showed that the proposed composition is as close as possible to the Bepanten ointment.Conclusion. A set of technological studies was carried out to optimize the composition of the Serpisten, 0.02 °% ointment on a diphilic basis. The developed composition and technology made it possible to obtain a composition with thermal stability, bring the hydrogen index of the ointment closer to the pH of human skin and achieve the parameters included in the rheological optimum for dermatological ointments (0.34-108 Pa • s).

Sporulation, Pilot-Scale Farming, Agar Quality and Ecotypic Variation of the Agar Seaweed Gracilaria Sordida.

<p>The purpose of this study was to investigate the sporulation behaviour, the feasibility of farming in an open-water system, the quality and quantity of agar from a range of populations, and the genetic variation of the important agarophyte Gracilaria sordida W.A. Nelson (Gracilariales, Rhodophyta), which is widely distributed around New Zealand. The mean, total output of carpospores and tetraspores, and the periodicity of their release from G. sordida plants collected in the Wellington area, were measured under different levels of salinity, temperature, light intensity and daily exposure time to the air. The conditions that gave the greatest carpospore release were found to be approximately 15-35%. NaCl, l5-20' C, 50-200 uE.m-2 s-1 and 1-3 h daily exposure time. The conditions that gave the greatest tetraspore release were found to be approximately 15%. NaCl, l5-20' C, 150-200 uE.m-2 s-1 and 2-4 h daily exposure time. The diurnal periodicity of carpospore and tetraspore discharge based on hourly recordings was also measured. The peak rate of spore output occurred in the morning (7:00-8:00 hours) and in the late afternoon (16:00-17:00 hours). The carpospores and tetraspores not only had the same size but also showed the same germination pattern. A year-long pilot-scale farming project involving seeding the spores of sexually mature plants of G. sordida onto nets and ropes in Pauatahanui Inlet, Porirua Harbour, proved that this seaweed can be grown from spores on artificial substrates in field conditions. Of the artificial substrates tested, the best one for spore attachment was found to be polypropylene rope, and the relative growth rate on this substrate was maximal in spring (3.4%.d-1). The estimated production rate was 18.2 tonnes of dry weight per hectare per year. Problems encountered during field culture included epiphytes, sedimentation, storm damage and theft of floats and ropes. Yield and gel strength of agar extracts were studied from G. sordida collected in summer from 23 sites around the country. Native agar yield ranged from 17% to 32% (dry weight). The yield of native agar from cultured samples of these populations ranged from l0% to 29%. The yield of alkali-pretreated agar ranged from 9% to 24%. The gel strength of native agar ranged from 30 to 307 g.cm-2. Agar gel strength after alkali-pretreatment ranged from 230 to 625 g.cm-2. Native agar gel strength from cultured samples ranged from 177 to 342 g.cm-2. The gelling temperature of agar from wild populations ranged from 39 to 47' C for native agar and from 38 to 45' C for alkali-pretreated agar. The melting temperature of native agar ranged from 79 to 98' C. The melting temperature of alkali-pretreated agar ranged from 85 to 98' C. The maximum relative growth rate obtained from samples of G. sordida populations cultured in plastic bags was 6.2%.d-1, which was obtained from the Aramoana population. Starch gel electrophoresis of proteins was used to measure genetic variation in G. sordida. Protein extracts were prepared from 17 wild populations around New Zealand and from samples of these populations cultured in plastic bags. 20 isozyme loci were examined in G. sordida samples. Results indicated that G. sordida has low levels of genetic variation. Only two loci (Gd-1 and Pgm-1) of the 20 loci investigated were polymorphic (10%). Estimated heterozygosity of G. sordida was 0.011. There was no genetic variation between a native population and its cultured sample. The genetic distances between all populations were small. From the cluster analysis, all populations could be divided into two groups. Results indicated that populations were independent of each other, in which the effects of selection and genetic drift prevail. The buffer systems which gave the best protein resolution were Ridgeway (RW), Tris-EDTA-Borate (TEB) and Tris-Glycine (TG) and the enzyme which gave the best result in all buffer systems tested was Glucose-6-phosphate dehydrogenase (GD).</p>

Sporulation, Pilot-Scale Farming, Agar Quality and Ecotypic Variation of the Agar Seaweed Gracilaria Sordida.

<p>The purpose of this study was to investigate the sporulation behaviour, the feasibility of farming in an open-water system, the quality and quantity of agar from a range of populations, and the genetic variation of the important agarophyte Gracilaria sordida W.A. Nelson (Gracilariales, Rhodophyta), which is widely distributed around New Zealand. The mean, total output of carpospores and tetraspores, and the periodicity of their release from G. sordida plants collected in the Wellington area, were measured under different levels of salinity, temperature, light intensity and daily exposure time to the air. The conditions that gave the greatest carpospore release were found to be approximately 15-35%. NaCl, l5-20' C, 50-200 uE.m-2 s-1 and 1-3 h daily exposure time. The conditions that gave the greatest tetraspore release were found to be approximately 15%. NaCl, l5-20' C, 150-200 uE.m-2 s-1 and 2-4 h daily exposure time. The diurnal periodicity of carpospore and tetraspore discharge based on hourly recordings was also measured. The peak rate of spore output occurred in the morning (7:00-8:00 hours) and in the late afternoon (16:00-17:00 hours). The carpospores and tetraspores not only had the same size but also showed the same germination pattern. A year-long pilot-scale farming project involving seeding the spores of sexually mature plants of G. sordida onto nets and ropes in Pauatahanui Inlet, Porirua Harbour, proved that this seaweed can be grown from spores on artificial substrates in field conditions. Of the artificial substrates tested, the best one for spore attachment was found to be polypropylene rope, and the relative growth rate on this substrate was maximal in spring (3.4%.d-1). The estimated production rate was 18.2 tonnes of dry weight per hectare per year. Problems encountered during field culture included epiphytes, sedimentation, storm damage and theft of floats and ropes. Yield and gel strength of agar extracts were studied from G. sordida collected in summer from 23 sites around the country. Native agar yield ranged from 17% to 32% (dry weight). The yield of native agar from cultured samples of these populations ranged from l0% to 29%. The yield of alkali-pretreated agar ranged from 9% to 24%. The gel strength of native agar ranged from 30 to 307 g.cm-2. Agar gel strength after alkali-pretreatment ranged from 230 to 625 g.cm-2. Native agar gel strength from cultured samples ranged from 177 to 342 g.cm-2. The gelling temperature of agar from wild populations ranged from 39 to 47' C for native agar and from 38 to 45' C for alkali-pretreated agar. The melting temperature of native agar ranged from 79 to 98' C. The melting temperature of alkali-pretreated agar ranged from 85 to 98' C. The maximum relative growth rate obtained from samples of G. sordida populations cultured in plastic bags was 6.2%.d-1, which was obtained from the Aramoana population. Starch gel electrophoresis of proteins was used to measure genetic variation in G. sordida. Protein extracts were prepared from 17 wild populations around New Zealand and from samples of these populations cultured in plastic bags. 20 isozyme loci were examined in G. sordida samples. Results indicated that G. sordida has low levels of genetic variation. Only two loci (Gd-1 and Pgm-1) of the 20 loci investigated were polymorphic (10%). Estimated heterozygosity of G. sordida was 0.011. There was no genetic variation between a native population and its cultured sample. The genetic distances between all populations were small. From the cluster analysis, all populations could be divided into two groups. Results indicated that populations were independent of each other, in which the effects of selection and genetic drift prevail. The buffer systems which gave the best protein resolution were Ridgeway (RW), Tris-EDTA-Borate (TEB) and Tris-Glycine (TG) and the enzyme which gave the best result in all buffer systems tested was Glucose-6-phosphate dehydrogenase (GD).</p>

Effect of Addition of Chokeberry Juice Concentrate and Foaming Agent on the Physical Properties of Agar Gel

This study aimed to determine the effect of the addition of chokeberry juice concentrate (CJC) and foaming agent (egg albumin) with different percentages on the selected physical properties of agar gel. The agar gels with the addition of 5, 10, and 20% concentrations of chokeberry juice concentrate and with fructose addition were prepared. In addition, the foamed gels with different concentrations of egg albumin (in the range 0.5–2.0%) and CJC were produced. The water content, colour, density, hold-up and some mechanical and TPA (Texture Profile Analysis) descriptors as well some structural and acoustic emission parameters of non-aerated and foamed gels were analysed. The addition of CJC changed the colour of agar gel with fructose, the attractive appearance of the aerated gel was also linked with the addition of concentrate. The addition of 20% of CJC and foaming agent created samples with very low hardness, cohesiveness, and gumminess, and the structure of the aerated samples was characterised by the larger bubble diameter and the wider distribution of their size. The more promising texture and structure properties were obtained for samples with aerated gels with 5 and 10% addition of chokeberry juice concentrate.

Comparative Evaluation of Extrusion of Apical Debris and Irrigant from Curved Root Canals Using Three Different Ni-Ti Instruments with Conventional Needle Irrigation Methods - An In Vitro Study

BACKGROUND Extrusion of debris, bacteria, and irrigant effect the inter-appointment flare ups and post-operative outcome of the endodontic treatment. So, it is necessary to make every effort to minimize such extrusion during cleaning and shaping of the canals. The present study was done to compare and evaluate debris and irrigant extrusion from curved root canals using different Ni-Ti systems. METHODS 30 mesial roots of mandibular molars were used in this study. Crown were decoronated, working length and initial apical diameter was established. 1.5 % agar gel model was used in this study. Samples were assigned randomly into 3 groups (n = 10 teeth per group). ProTaper Next, One Shape, FANTA AF BLUE F ONE files were used according to the manufacturer’s instructions for canal instrumentation. Apically extruded debris and irrigant was computed after the biomechanical preparation and their comparative analysis for each of the instruments and experimental models was performed. RESULTS Statistically significant difference was found between the three experimental groups. (P < .05). CONCLUSIONS All the instruments produced apically extruded debris and irrigant, but least was seen with FANTA AF BLUE F ONE and maximum with One Shape among the experimental groups. KEY WORDS Apical Debris, Irrigant, NiTi Files

Optimization of Copper Stain Removal from Marble through the Formation of Cu(II) Complexes in Agar Gels

Copper complexes with different ligands (ethylenediaminetetraacetic acid, EDTA, ammonium citrate tribasic, TAC, and alanine, ALA) were studied in aqueous solutions and hydrogels with the aim of setting the optimal conditions for copper stain removal from marble by agar gels, with damage minimization. The stoichiometry and stability of copper complexes were monitored by ultraviolet-visible (UV-Vis) spectroscopy and the symmetry of Cu(II) centers in the different gel formulations was studied by electron paramagnetic resonance (EPR) spectroscopy. Cleaning effectiveness in optimized conditions was verified on marble laboratory specimens through color variations and by determining copper on gels by inductively coupled plasma-mass spectrometry (ICP-MS). Two copper complexes with TAC were identified, one having the known stoichiometry 1:1, and the other 1:2, Cu(TAC)2, never observed before. The stability of all the complexes at different pH was observed to increase with pH. At pH 10.0, the gel’s effectiveness in removing copper salts from marble was the highest in the presence of ALA, followed by EDTA, TAC, and pure agar gel. Limited damage to the marble surface was observed when gels with added EDTA and TAC were employed, whereas agar gel with ALA was determined to be the most efficient and safe cleaning material.