An expansive clay for centrifuge modelling

This paper explores the development of an expansive soil which can be repeatedly reproduced for use in centrifuge models to investigate soil-structure interaction problems involving expansive soils. The study considered two materials, namely a sand-bentonite mixture and a naturally occurring, highly expansive clay. For the natural material, two approaches were explored to create a scaled down fissured structure for use in centrifuge testing. The swell behaviour of the two candidate materials was first investigated by means of oedometer tests and then by centrifuge modelling. The centrifuge tests consisted of layers of compacted clay slabs separated by free draining layers. The study revealed that while the sand-bentonite mixture possessed the potential to swell significantly, the time required to do so was impractical for centrifuge studies. It was however found that the approach used to create a scaled down fissured structure in the naturally occurring clay facilitated rapid ingress of water which allowed for significant heave to take place in a much shorter time frame. The results obtained from the centrifuge test conducted on the reworked clay were compared with an empirical heave prediction method and it was found that the swell obtained from the fissured clay matched the predicted heave profile within three hours

Hydromechanical characterisation of a highly expansive clay

The hydromechanical properties of a South African expansive clay are reported. In this study,swell potential and swell pressure were assessed by two oedometric approaches, namely, the loading after wetting test and the wetting after loading test. The data indicate that predictions of swell pressure from the two approaches remain similar, whereas greater predictions of heave are obtained for the loading after wetting approach. It is also observed that the magnitude of predicted heave from the loading after wetting test is dependent on the soaking stress considered, with greater swell being obtained for lower soaking stresses. Measurements of primary drying and wetting curves illustrate appreciable hysteresis in the intermediate suction range (≈17 MPa). The discrepancy of this finding with that of a previous study is attributed to differences in fabric. Additionally, when examining the volumetric response of a sample subjected to a drying and wetting path, negligible hysteresis is observed when void ratio is plotted as a function of gravimetric water content. Conversely, when the shrinkage/swell curves are plotted in terms of suction, irreversibly volumetric changes are apparent

Synthesis and antioxidant activity of long chain alkyl hydroxycinnamates

Long chain alkyl hydroxycinnamates (8e21) were synthesized from the corresponding half esters of malonic acid (5e7) and benzaldehyde derivatives by Knoevenagel condensation. The total antioxidant capacity of these hydroxycinnamyl esters was evaluated using DPPH and ABTS assays. The observed antioxidant activity was highest for esters of caffeic acid followed by sinapic esters and ferulic esters. The parameters for drug-likeness of these hydroxycinnamyl esters were also evaluated according to the Lipinski’s ‘rule-of-five’. All the ester derivatives were found to violate one of the Lipinski’s parameters (cLogP >5), even though they have been found to be soluble in protic solvents. The predictive topological polar surface area (TPSA) data allow concluding that they could have a good capacity for penetrating cell membranes. Therefore, one can propose these novel lipophilic compounds as potential antioxidants for tackling oxidative processes.info:eu-repo/semantics/publishedVersio

Centrifuge modelling of piled foundations in swelling clays

A study aimed towards assessing the variation in shaft capacity of piled foundations in swelling clays is presented. At the clay’s in-situ water content, the results of pull-out tests on short length piles revealed no dependency of shaft capacity on overburden stress. Conversely, after achieving a targeted value of swell, a strong dependency on overburden stress was observed. In upper portions of the profile where swell can occur relatively freely, swell-induced softening results in a reduction in pile shaft capacity. However, at greater depths where swell is largely suppressed, so too are the effects of swell-induced softening. For this reason, shaft capacity at depth was found to remain relatively constant before and after swell. The results of an instrumented pile test revealed an overriding dependency of lateral induced swell pressure on the magnitude of heave which has occurred. Irrespective of the level of overburden stress, lateral pressures against the pile were found to increase at early stages of the swelling process, but then reduce as swell continued and softening began to occur. Such a result highlights the importance of specifying the level of swell at which shaft capacity should be assessed if a conservative design is to be obtained

Drying and wetting soil-water retention behaviour of a highly expansive clay under varying initial density

Expansive (or swelling) clays are the most prolific problem soil across Southern Africa and many parts of the world. Large volume changes due to seasonal wetting and drying cause millions of dollars’ worth of damage to engineering infrastructure yearly. Soil-water retention behaviour is dependent ondensity, and determining the correct retention curve may be key for reliable design of infrastructure. Soilwater retention curves and shrinkage curves were measured for recompacted samples of a highly expansive bentonite clay from South Africa. Four samples were prepared at varying initial dry densities between approximately 1200 and 1500 kg/m3 and subjected to total suction testing in a dewpoint hygrometer. The water content of each sample was varied through wetting and drying. The sample volume was measured after each suction reading, allowing relationships between suction and void ratio, degree of saturation and water content to be determined. The relationship between gravimetric water content and suction was not significantly influenced by initial density. Degree of saturation at a given suction varied significantly according to initial density. Volume reductions of 25% to 36% from saturated to residual conditions were recorded, and samples tended to a residual void ratio of 0.35 to 0.4. The swelling clay showed propensity for maintaining high suctions (over 300 MPa at residual conditions) and hysteretic response between primary drying and wetting

The Role of Rosmarinic Acid on the Bioproduction of Gold Nanoparticles as Part of a Photothermal Approach for Breast Cancer Treatment.

Breast cancer is a high-burden malignancy for society, whose impact boosts a continuous search for novel diagnostic and therapeutic tools. Among the recent therapeutic approaches, photothermal therapy (PTT), which causes tumor cell death by hyperthermia after being irradiated with a light source, represents a high-potential strategy. Furthermore, the effectiveness of PTT can be improved by combining near infrared (NIR) irradiation with gold nanoparticles (AuNPs) as photothermal enhancers. Herein, an alternative synthetic method using rosmarinic acid (RA) for synthesizing AuNPs is reported. The RA concentration was varied and its impact on the AuNPs physicochemical and optical features was assessed. Results showed that RA concentration plays an active role on AuNPs features, allowing the optimization of mean size and maximum absorbance peak. Moreover, the synthetic method explored here allowed us to obtain negatively charged AuNPs with sizes favoring the local particle accumulation at tumor site and maximum absorbance peaks within the NIR region. In addition, AuNPs were safe both in vitro and in vivo. In conclusion, the synthesized AuNPs present favorable properties to be applied as part of a PTT system combining AuNPs with a NIR laser for the treatment of breast cancer

ÍNDICES PROLIFERATIVOS DO TUMOR VENÉREO CANINO TRANSMISSÍVEL PELAS TÉCNICAS DO CEC E KI-67 NA CITOLOGIA ASPIRATIVA COM AGULHA FINA

A citologia aspirativa com agulha fina (CAAF) foi usada como método de colheita de quinze amostras de tumor venéreo transmissível (TVT)em cães, oriundos do atendimento do Hospital Veterinário-FMVZ-UNESP de Botucatu, antes e após o início da quimioterapia. As amostras citológicas foram submetidas ao cálculo do índice mitótico e à avaliação de índices de proliferação por métodos citoquímico (concentração eletrolítica crítica CEC) e imunocitoquímico (Ki-67, clone MIB-1). Todas as técnicas mostraram-se adequadas para avaliar a taxa proliferativa em amostras citológicas. O CEC permitiu observar que a aplicação do quimioterápico levou a uma redução significativa da proliferação celular. Em vista disso, conclui-se que essa metodologia pode ser aplicada para diagnosticar e monitorar o TVT. Proliferation indexes determination by CEC and Ki-67 in fine needle aspiration cytology of transmissible venereal tumor Abstract Fine needle aspiration biopsy (FNAB) was used to collect fifteen transmissible venereal tumor (TVT) samples from dogs at the Veterinary Hospital - FMVZ - UNESP Botucatu, São Paulo, Brazil, before and after beginning of chemotherapy. The cytological samples were submitted to determination of mitotic and proliferation indexes by means of cytochemical (critical electrolyte concentration CEC) and immunocytochemical (Ki-67, MIB-1 clone) methods. All the techniques were adequate for the evaluation of proliferation rates displayed by the cytological samples. The CEC allowed the observation that chemotherapy induces to significant reduction in cellular proliferation. Thus, was concluded that this methodology is suitable to perform TVT diagnosis and monitoration

Novel downstream process and analytical tools developed for Influenza VLP vaccine

Vaccination remains the most effective way to prevent the infection with Influenza viruses. However, their constant antigenic drift implies that current human Influenza vaccines need to be annually updated with high inherent costs. Virus-like particles (VLPs) have become widely used as vaccine candidates because of their versatility, immunogenicity, and safety profile. In this iBET project we are attempting to produce a candidate for a universal vaccine for which 35 different VLPs (mono, trivalent and pentavalent) were purified. Here we describe three recent advances on Influenza VLPs bioprocessing: two new analytical tools and the development of an integrated all filtration purification process, inserted in the “anything but chromatography” concept. The first method is a label-free tool that uses Biolayer interferometry technology applied on an Octet platform to quantify Influenza VLPs at all stages of DSP. Human and avian sialic acid receptors were used, in order to quantify hemagglutinin (HA) content in several mono- and multivalent Influenza VLP strains. The applied method was able to detect and quantify HA from crude sample up to final VLP product with high throughput, real-time results and improved detection limits, when compared to traditional approaches, crucial for in-line monitoring of DSP. Using a click-chemistry approach that involves Azidohomoalanine incorporation and functionalization, Influenza VLPs were selectively and fluorescently tagged. Taking into account that this chemical tag does not affect particle size, charge and biological activity we report here a valuable tool to online/at-line product monitoring during DSP optimization of virus related biopharmaceuticals. Moreover, using this tool coupled with FACS we were able to discriminate between VLPs and baculovirus, the major impurity of the system. The proposed all-filtration process will be described, with special focus on the clarification stage, followed by multiple ultrafiltration and diafiltration steps to achieve the needed concentration and purity specifications. Using this all-filtration platform, we are able to speed up the time process, to improve the scale-up and to reduce costs due to the removal of chromatographic steps

The COMPASS Experiment at CERN

The COMPASS experiment makes use of the CERN SPS high-intensitymuon and hadron beams for the investigation of the nucleon spin structure and the spectroscopy of hadrons. One or more outgoing particles are detected in coincidence with the incoming muon or hadron. A large polarized target inside a superconducting solenoid is used for the measurements with the muon beam. Outgoing particles are detected by a two-stage, large angle and large momentum range spectrometer. The setup is built using several types of tracking detectors, according to the expected incident rate, required space resolution and the solid angle to be covered. Particle identification is achieved using a RICH counter and both hadron and electromagnetic calorimeters. The setup has been successfully operated from 2002 onwards using a muon beam. Data with a hadron beam were also collected in 2004. This article describes the main features and performances of the spectrometer in 2004; a short summary of the 2006 upgrade is also given.Comment: 84 papes, 74 figure