Yes / The DNA damage response (DDR) is now known to play an important role in both cancer development and its treatment. Targeting proteins such as ATR (Ataxia telangiectasia mutated and Rad3-related) kinase, a major regulator of DDR, has demonstrated significant therapeutic potential in cancer treatment, with ATR inhibitors having shown anti-tumour activity not just monotherapies, but also in potentiating the effects of conventional chemotherapy, radiotherapy, and immunotherapy. This review focuses on the biology of ATR, its functional role in cancer development and treatment, and the rationale behind inhibition of this target as a therapeutic approach, including evaluation of the progress and current status of development of potent and specific ATR inhibitors that have emerged in recent decades. The current applications of these inhibitors both in preclinical and clinical studies either as single agents or in combinations with chemotherapy, radiotherapy and immunotherapy are also extensively discussed. This review concludes with some insights into the various concerns raised or observed with ATR inhibition in both the preclinical and clinical settings, with some suggested solutions.

Moisture damage in asphalt mixtures is a complex phenomenon that involves mechanical, chemical, physical and thermodynamic processes. This damage contributes significantly to the premature deterioration of asphalt pavements, which leads to extra cost in highway maintenance and vehicle operations. One key mechanism of how moisture reaches the asphalt-aggregate interface is by its permeation or diffusion through the asphalt binder or mastic. Different techniques are available for diffusion coefficient measurement of a wide variety of polymersolvent systems. For the asphalt-water system studied, the focus is on two techniques: (i) Fourier Transform Infrared (FTIR)-Attenuated Total Reflectance (ATR) spectrometry and (ii) Gravimetric Sorption Measurements. In the FTIR-ATR experiments, asphalt binders are under investigation. Water shows strong absorption in the infrared region and the FTIR-ATR technique has the ability to monitor both the kinetics of moisture ingress as well as any chemical changes occurring during the test. The changes in concentration can be directly related to change in the absorbance measured during the experiment. The hysteresis of water diffusion in asphalt binders is also monitored through this technique. In the gravimetric sorption experiments, cylindrical Fine Aggregate Mixtures (FAM) were investigated. The gravimetric techniques, which directly follow mass change with time, are among the most used techniques probably because of their simplicity. In this experiment, the Saturated Surface-Dry (SSD) weight of FAM samples at room temperature and at 100 degrees F is monitored until it reaches the equilibrium. The measurements of: (i) water uptake and (ii) the diffusion coefficient were made at both temperatures. A dual mode diffusion model was shown to better represent the diffusion of water through asphalt binders. The rate of moisture diffusion in asphalt binders was proved to be dependent on the history of exposure of the asphalt binder to the moisture. Moisture uptake and diffusivity of water through FAM is dependent on the type of aggregate and asphalt binder used to prepare the FAM.

The attenuated total reflection (ATR) method and the scattering spectrum analysis are used to study the effects due to the surface plasma of Ag nanoparticles. A slide is coated with a thin Ag film of thickness about 40nm and anneals the sample few minutes at 197¢XC. The Ag film is thus congregated to be a rough surface. By ATR(with the slide attached to the back of the prism), the intensity of the total refection light and the reflective angle are measured. Then we can determine the dielectric coefficient of the rough Ag surface. We also coat a thin Ag film about 8nm on the ITO glass and anneal the sample. The thin Ag film is thus congregated to be nanoparticles. We discuss the effects due to the surface plasma excited on the Ag nanoparticles by analyzing the absorbance and scattering spectrums from Ag nanoparticles in liquid crystals environment.

The work embodied in this dissertation is specifically focused on the evanescent interaction of light with thin-films which has lead to two related instrument based projects: i) the Electroactive Fiber-Optic Chip (EA-FOC) and ii) Attenuated Total Reflectance (ATR) spectroscopy of novel materials. The EA-FOC combines the sensitivity of an electroactive total internal reflection element (20 to 50 times more sensitive than a transmission experiment) with the ease of use of fiber-optic based CCD spectrometers. A side-polished optical fiber, in a V-groove glass mount, forms the planar platform, which allows access to the evanescent field escaping from the fiber core. The exposed evanescent field, which was used to probe molecules or molecular assemblies supported by the platform, has an interaction area ca. 0.05 cm squared. Thin-film and bulk absorbing samples, and waveguide modeling calculations were initially used to evaluate the sensitivity of the FOC platform, which was found to be analogous to ATR instrumentation. The wavelength range of the FOC platform was increased to include the near-UV and applied to monitor adsorption of a protein film. Fluorescence applications of the FOC were demonstrated using a fluorescence bioassay and a drop cast nanoparticle film. Finally, a transparent conducting oxide film, ITO, was added to the surface of the platform to complete the EA-FOC for spectroelectrochemical applications. A methylene blue redox couple and an electrodeposited ultra-thin PEDOT film were used to probe the capabilities of the EA-FOC. The EA-FOC was shown to be a multifunctional platform for advanced sensor technologies requiring absorbance, fluorescence, and electrochemical detection or a combination thereof.ATR spectroscopy of novel materials included the evaluation of two architectures: i) a pH sensitive polyelectrolyte film and ii) surface capture of a nanoparticle film. Absorbance spectra of a polyaniline/polyacetic acid self-assembled bilayer were evaluated with respect to pH and potential using ATR spectroscopy; the ultimate application of the polymer signal transduction layer was to monitor proton transport across a lipid-bilayer. Additionally, ATR spectroscopy was used to monitor adsorption of pyridine capped nanoparticles on a silyl-propyl-thiol modified surface.

O laser tem se mostrado eficaz no auxílio ao profissional de saúde, sendo extensivamente utilizado em procedimentos médicos e odontológicos nas ultimas décadas. Em particular, os lasers de alta intensidade emissores no infravermelho possuem grande potencial para corte de tecidos biológicos mineralizados, visto que são bastante absorvidos pela hidroxiapatita e água, principais componentes desses tecidos. Em comparação aos instrumentos mecânicos, o laser apresenta uma série de vantagens no corte de tecidos, com possibilidade de menor dano ao tecido remanescente e melhor hemostasia. Entretanto, para uma aplicação eficiente e segura é necessário conhecer os efeitos que a irradiação laser causa ao tecido. A técnica de espectroscopia no Infravermelho por Transformada de Fourier (FTIR) é bastante utilizada no estudo de materiais orgânicos, pois além de permitir a identificação de componentes, possibilita uma análise semiquantitativa. Este trabalho tem como objetivos estabelecer a técnica de ATR-FTIR para caracterização do tecido ósseo natural e irradiado, e verificar as eventuais mudanças químicas e estruturais causadas pela irradiação laser. Primeiramente, foram determinadas as melhores condições instrumentais para a obtenção dos espectros de amostras de osso. Posteriormente foram analisadas as amostras de osso natural e irradiado com o laser de Er,Cr:YSGG (2,78 μm) com diferentes densidades de energia. Verificou-se que a técnica foi eficaz na caracterização do tecido ósseo, sendo possível observar as alterações químicas promovidas pelo aumento de temperatura ocasionado pela irradiação laser. Foi observada a perda gradativa de material orgânico em função do aumento da densidade de energia utilizada. Os resultados obidos são os primeiros passos para a verificação da eficácia do laser de Er,Cr:YSGG quando empregado como uma ferramenta de corte, essencial para sua consolidação na prática clínica. / Laser proves to be, more and more, an effective tool for helping health professionals, being intensively used in ophthalmological and odontological procedures. In particular, high-density, infrared emitting lasers have great potential in cutting mineralized biological hard tissues, given their high absorption by hydroxyapatite and water, these tissues main components. In comparison to mechanical instruments, laser presents a series of advantages, namely, smaller damage to the remaining tissue and promotion of homeostatic effect, apart from making it possible to execute procedures in areas with difficult access. However, for an efficient and safe use of this technique, it is necessary to know the effects of the laser irradiation on the tissue. The Fourier transform infrared (FTIR) technique is heavily used in the study of organic materials, because apart from making it possible to identify the materials components, it also allows to prepare a semi quantitative analysis. This work aims to establish the ATR-FTIR technique in the characterization of natural and irradiated osseous tissue, and to verify the possible chemical and structural changes caused by irradiation. Firstly, the best conditions for the obtainment of bone sample spectra were determined. Then, bone samples, irradiated with the Er,Cr:YSGG (2,78 μm) infrared emitting laser (adjusted with different energy densities) were analyzed alongside with natural bone samples. It has been verified that the technique is effective in the bone tissue characterization, and that it is possible to observe the chemical changes caused by the temperature rise due to laser irradiation. It has been observed a gradual organic material loss as the energy density goes up. These results are the first steps in testing the Er,Cr:YSGG laser efficacy as a cutting tool, a pivotal aspect of its consolidation in clinical procedures.

O laser tem se mostrado eficaz no auxílio ao profissional de saúde, sendo extensivamente utilizado em procedimentos médicos e odontológicos nas ultimas décadas. Em particular, os lasers de alta intensidade emissores no infravermelho possuem grande potencial para corte de tecidos biológicos mineralizados, visto que são bastante absorvidos pela hidroxiapatita e água, principais componentes desses tecidos. Em comparação aos instrumentos mecânicos, o laser apresenta uma série de vantagens no corte de tecidos, com possibilidade de menor dano ao tecido remanescente e melhor hemostasia. Entretanto, para uma aplicação eficiente e segura é necessário conhecer os efeitos que a irradiação laser causa ao tecido. A técnica de espectroscopia no Infravermelho por Transformada de Fourier (FTIR) é bastante utilizada no estudo de materiais orgânicos, pois além de permitir a identificação de componentes, possibilita uma análise semiquantitativa. Este trabalho tem como objetivos estabelecer a técnica de ATR-FTIR para caracterização do tecido ósseo natural e irradiado, e verificar as eventuais mudanças químicas e estruturais causadas pela irradiação laser. Primeiramente, foram determinadas as melhores condições instrumentais para a obtenção dos espectros de amostras de osso. Posteriormente foram analisadas as amostras de osso natural e irradiado com o laser de Er,Cr:YSGG (2,78 μm) com diferentes densidades de energia. Verificou-se que a técnica foi eficaz na caracterização do tecido ósseo, sendo possível observar as alterações químicas promovidas pelo aumento de temperatura ocasionado pela irradiação laser. Foi observada a perda gradativa de material orgânico em função do aumento da densidade de energia utilizada. Os resultados obidos são os primeiros passos para a verificação da eficácia do laser de Er,Cr:YSGG quando empregado como uma ferramenta de corte, essencial para sua consolidação na prática clínica. / Laser proves to be, more and more, an effective tool for helping health professionals, being intensively used in ophthalmological and odontological procedures. In particular, high-density, infrared emitting lasers have great potential in cutting mineralized biological hard tissues, given their high absorption by hydroxyapatite and water, these tissues main components. In comparison to mechanical instruments, laser presents a series of advantages, namely, smaller damage to the remaining tissue and promotion of homeostatic effect, apart from making it possible to execute procedures in areas with difficult access. However, for an efficient and safe use of this technique, it is necessary to know the effects of the laser irradiation on the tissue. The Fourier transform infrared (FTIR) technique is heavily used in the study of organic materials, because apart from making it possible to identify the materials components, it also allows to prepare a semi quantitative analysis. This work aims to establish the ATR-FTIR technique in the characterization of natural and irradiated osseous tissue, and to verify the possible chemical and structural changes caused by irradiation. Firstly, the best conditions for the obtainment of bone sample spectra were determined. Then, bone samples, irradiated with the Er,Cr:YSGG (2,78 μm) infrared emitting laser (adjusted with different energy densities) were analyzed alongside with natural bone samples. It has been verified that the technique is effective in the bone tissue characterization, and that it is possible to observe the chemical changes caused by the temperature rise due to laser irradiation. It has been observed a gradual organic material loss as the energy density goes up. These results are the first steps in testing the Er,Cr:YSGG laser efficacy as a cutting tool, a pivotal aspect of its consolidation in clinical procedures.

At Cameco mine sites in northern Saskatchewan, naturally occurring elements of concern (EOC) such as As, Ni, Mo, and Se are present in uranium ore bodies. Ferrihydrite (Fh) is found in tailings management facilities (TMF) and is known to sequester arsenates and arsenites. Fh is known to be metastable and undergo phase transformations to goethite (α-FeOOH) and hematite (α-Fe2O3). Reductive conditions are known to be a driving force in Fh transformation and the release of adsorbed As species from the surface. This study uses electrochemistry to control reductive potentials applied to Fh adsorbed As species. Electrochemistry was coupled with attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to determine the behaviour of adsorbed arsenate and arsenite on the Fh surface. The potentials required to desorb As(III) and As(V) from the Fh surface were negative enough to cause the reduction of water, thus increasing the pH of the solution through the generation of OH-. In order to measure the extent of the pH change a miniature palladium/palladium oxide pH sensor was fabricated in order to make in-situ pH measurements during spectroelectrochemical studies. Additionally, in-situ solution potential (Eh) measurements were made during potential control. It was found that potential induced pH and Eh changes were significant enough to release arsenite from the Fh surface. Arsenate was also found to desorb from Fh during the application of reductive potentials though successive deprotonation leading to a totally deprotonated As(V) species.

No description available.

In many experiments, surfactant adsorption and desorption at solid-liquid interfaces is found to be quite slow, considering that surfactants are small molecules. Attenuated total reflectance Fourier transform infrared spectroscopy was used to study the adsorption, desorption, and exchange of tetradecyltrimethylammonium bromide (C₁₄TABr) at the silicon oxide surface. The exchange of surfactant was monitored using protonated and perdeuterated C₁₄TABr. The data show that exchange of C₁₄TABr between the surface and the bulk solution is very fast, complete exchange occurs in less than 10 seconds. A simple exchange model suggests that the disassociation rate constant of a single monomer is no less than 1 s^-1, which is ~ 10⁴ times slower than monomer exchange in bulk solutions. The actual exchange rate may be greater than observed in the present work due to transport phenomena. The rates of exchange are similar at concentrations above and below the critical micellar concentration. Adsorption is similarly rapid, but under some circumstances there is a small residue of surfactant that is slow to desorb. Desorption experiments utilizing KBr solutions of high and low ionic strength show that two thirds of each adsorbed micelle is held by hydrophobic association, and the other third is electrostatically bound. Adsorption, desorption, and exchange experiments at temperatures of 11°C above and 8°C below the Krafft temperature (14.4°C) show similar kinetics. / Master of Science

Yes / A hallmark of the conserved ATM/ATR signalling is its ability to mediate a wide range of functions utilizing only a limited number of adaptors and effector kinases. During meiosis, Tel1 and Mec1, the budding yeast ATM and ATR, respectively, rely on a meiotic adaptor protein Hop1, a 53BP1/Rad9 functional analog, and its associated kinase Mek1, a CHK2/Rad53-paralog, to mediate multiple functions: control of the formation and repair of programmed meiotic DNA double strand breaks, enforcement of inter-homolog bias, regulation of meiotic progression, and implementation of checkpoint responses. Here, we present evidence that the multi-functionality of the Tel1/Mec1-to-Hop1/Mek1 signalling depends on stepwise activation of Mek1 that is mediated by Tel1/Mec1 phosphorylation of two specific residues within Hop1: phosphorylation at the threonine 318 (T318) ensures the transient basal level Mek1 activation required for viable spore formation during unperturbed meiosis. Phosphorylation at the serine 298 (S298) promotes stable Hop1-Mek1 interaction on chromosomes following the initial phospho-T318 mediated Mek1 recruitment. In the absence of Dmc1, the phospho-S298 also promotes Mek1 hyper-activation necessary for implementing meiotic checkpoint arrest. Taking these observations together, we propose that the Hop1 phospho-T318 and phospho-S298 constitute key components of the Tel1/Mec1- based meiotic recombination surveillance (MRS) network and facilitate effective coupling of meiotic recombination and progression during both unperturbed and challenged meiosis. / MRC program grant U1175.01.005.00005.01 from RSC and MRC centre grant G0801130 from JAC. / Erratum: 18 Apr 2016: Penedos A, Johnson AL, Strong E, Goldman AS et al (2016) Correction: Essential and Checkpoint Functions of Budding Yeast ATM and ATR during Meiotic Prophase Are Facilitated by Differential Phosphorylation of a Meiotic Adaptor Protein, Hop1. PLOS ONE. 11(4): e0154170. https://doi.org/10.1371/journal.pone.0154170.