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Introduction Diabetes mellitus (DM) is a chronic metabolic disease with epidemiological relevance worldwide. One of the most common and most underestimated complications of diabetes is erectile dysfunction (ED). It is estimated that approximately 35-90% of diabetic men present ED as an early complication. Previous studies have shown that TRPM8 activation triggers relaxation of pudendal artery with increased sensitivity in the hypertensive rats. However, despite the correlation between ED and diabetes, research on the role of TRPM8 channels in the vasculature responsible for sexual function in diabetic condition still needs to be elucidated. Objective In this way, the aim of this study was to investigate TRPM8 channels in arteries vital to erection of the penis. We hypothesized that TRPM8 activation would induce relaxation and reduce sensitivity to alpha-adrenergic stimulation in pudendal arteries from diabetic mice. Methods Male control and db/db mice were euthanized, and the internal pudendal arteries were mounted on DMT wire myographs for the measurement of isometric force. Results Cumulative administration of icilin (10-8 to 10-4M), a TRPM8 agonist, induced endothelium-dependent and endothelium-independent relaxation in pre-contracted rings with phenylephrine (Phe,1μM). Relaxant effect induced by icilin was similar between pudendal arteries from db/db (Emax: 56.31 +/− 1.90%, n=5) and control (Emax:46.57 +/− 4.45%, n=5) mice. Diabetes increased the contractility of the pudendal artery in response to phenylephrine in concentration of 3x10-6M (99.40 +/− 4.65%, n=4) compared to control (85.44 +/− 2.36%, n=4). Interestingly, pre-incubation with icilin (10-4M) decreased the potency of the contraction induced by phenylephrine (10-9 to 3x10-5M) compared to untreated rings in both diabetic (pD2: 6.39 +/− 0.07 vs 6.67 +/− 0.05, n=4) and control (pD2: 6.43 +/− 0.09 vs 6.82 +/− 0.05, n=4) animals. In the pudendal artery, diabetes decreased the sensitivity to acetylcholine compared to control (pD2: 7.17 +/− 0.06 vs 7.42 +/− 0.03, n=4). However, the relaxation induced by acetylcholine (10-9 to 3x10-5M) was not changed by pre-incubation with icilin. Conclusions Icilin is able to promote relaxation with the same magnitude in pudendal arteries from diabetic and control mice. Increased responses to phenylephrine in pudendal artery may contribute to the development of ED. In addition, pre-incubation with icilin reduced sensitivity to phenylephrine, suggesting that the icilin could be a helpful treatment for ED. Disclosure No

Dentists could fail to notice periapical lesions (PLs) while examining panoramic radiographs. Accordingly, this study aimed to develop an artificial intelligence (AI) designed to address this problem. Materials and methods: a total of 18618 periapical root areas (PRA) on 713 panoramic radiographs were annotated and classified as having or not having PLs. An AI model consisting of two convolutional neural networks (CNNs), a detector and a classifier, was trained on the images. The detector localized PRAs using a bounding-box-based object detection model, while the classifier classified the extracted PRAs as PL or not-PL using a fine-tuned CNN. The classifier was trained and validated on a balanced subset of the original dataset that included 3249 PRAs, and tested on 707 PRAs. Results: the detector achieved an average precision of 74.95%, while the classifier accuracy, sensitivity and specificity were 84%, 81% and 86%, respectively. When integrating both detection and classification models, the proposed method accuracy, sensitivity, and specificity were 84.6%, 72.2%, and 85.6%, respectively. Conclusion: a two-stage CNN model consisting of a detector and a classifier can successfully detect periapical lesions on panoramic radiographs.

Background and Aims Patients on renal replacement therapy (RRT) pose multiple risk factors that may increase the risk of death from coronavirus disease 2019 (COVID-19). Currently, evidence of incidence, management, and prognosis of COVID-19 in this population are scarce. Method Between May and December 2020, we followed two RRT populations that have the same tertiary hospital in Southern Brazil as its reference hospital for transplantation. Firstly, we monitored eight affiliated dialysis clinics keeping track of COVID-19 incidence and fatality rate in dialysis patients and those on the kidney transplant waiting list. In the same period, we also monitor COVID-19 incidence and mortality among our prevalent population of kidney transplant recipients. Results We evaluated 1049 patients in RRT in the dialysis centers. COVID-19 occurred in 89 of such patients (8.5%), and 31 died from such condition (35.8% death rate). Fifteen patients (5.45%), among 275 on the kidney transplant waiting list, contracted the virus, with one death (6.6%). Within our prevalent population of 1348 kidney transplant recipients, 113 were diagnosed with COVID19 (incidence: 8.4%), and 17 of them died (mortality rate: 15%). Finally, the number of kidney transplants decreased by 60.4% compared with the same period in the previous year. Conclusion COVID-19 determined a substantial impact on RRT. A high frequency of chronic dialysis patients expired from the disease. The impact on the patients on the transplant waiting list seems to be less pronounced probably due to their better health conditions. The fatality rate in kidney transplant recipients is elevated and probably mostly related to comorbidities. Brazil is currently entering the second wave of the disease and it is crucial to find and provide means to protect such vulnerable populations.

Tricalcium phosphate (TCP) is a biomaterial produced in several biomedical applications, in addition to having biocompatibility and osteoconductive capacity. Biodegradable polymers of natural or synthetic origin such as chitosan and polyvinyl alcohol (PVA) have been used for tissue engineering applications because they have the properties of the native organic phase of bone tissue. Thus, the objective of this study was to obtain ceramic tapes based on TCP, chitosan, and PVA through the tape casting method. The viscosity data for all suspensions were ideal for the chosen processing. The thermogravimetric curves showed similar profiles, and it was possible to observe that a greater total mass loss occurred with the increase in the chitosan content. XRD reflections related to the β-TCP phase of the orthorhombic structure were found, showing no phase transformation. SEM analysis showed degrees of roughness on the film surfaces with little influence from the increase in chitosan content. Resumo O fosfato tricálcico (TCP) é um biomaterial que está sendo produzido em diversas aplicações biomédicas, além de sua biocompatibilidade e capacidade osteocondutora. Polímeros biodegradáveis de origem natural ou sintética, como quitosana e poli(álcool vinílico) (PVA), vêm sendo utilizados para aplicações de engenharia de tecidos por apresentarem as propriedades da fase orgânica nativa do tecido ósseo. Desse modo, o objetivo deste trabalho foi a obtenção de filmes finos cerâmicos baseados em TCP, quitosana e PVA através do método de tape casting. Dados de viscosidade para todas as suspensões mostraram-se ideais para o processamento escolhido. As curvas termogravimétricas demonstraram perfis semelhantes e foi possível observar que com o aumento do teor de quitosana ocorreu maior perda de massa total. Reflexões de DRX relacionadas à fase β-TCP de estrutura ortorrômbica foram encontradas, evidenciando que não houve transformação de fases. A análise de MEV revelou graus de rugosidade nas superfícies dos filmes com pouca influência do aumento do conteúdo de quitosana.

A comparison between the Zn-Ni, Zn-Ni-Fe and Zn-Ni-Co coatings was performed in this study. The co-deposition process was obtained by electrodeposition on ASTM A624 steel using sulphate baths in acid media and low current density. The characterization of the coatings by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP OES), Energy Dispersive Spectroscopy (EDS), X-ray diffraction (XRD) and Anodic Linear Sweep Voltammetry (ALSV) allowed a detailed analysis of the phases formed and its amounts in the coatings, which enabled to verify the influence of the Fe and Co co-deposited separately with Zn/Ni. The co-deposits showed different characteristics in relation to the deposition efficiency and film thickness, in addition of the topography and surface roughness, which were measured by a confocal optical microscope and of the hardness determined by an ultra-microhardness tester. Finally, the corrosion tests analyzed by open circuit potential, potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS) determined the corrosion characteristics of each co-deposit in saline solution. Results showed that Zn-Ni-Co was superior to the others co-deposits in relation to the deposit efficiency and corrosion protection, in contrast, the Zn-Ni-Fe coating showed uniformity and the greater compaction of the surface grains, resulting in lower roughness and higher hardness between the co-deposits studied.

Industrial development, intensive agriculture and fast urbanization have caused the metal contents of soils to increase to many times the allowable limits. To assess this impact on urban and rural soils, we quantified the Cd, Cr, Cu, Pb, Ni and Zn contents of 258 soil samples from the Recife metropolitan region (RMR). The objectives of the study were to estimate the probability of ecological risk, to determine the spatial pattern of the metals’ accumulation in the soil and to identify potential sources for the metals using a multivariate geostatistical approach. Mean concentrations of Zn, Cr, Pb, Cu, Ni and Cd in soils were 65.2, 17.9, 16.5, 12.8, 6.3 and 1.5 mg kg−1, respectively. The results demonstrated that the Cd was anthropogenic in origin, the Cr and Ni were lithogenic (natural) in origin and the Cu, Pb and Zn were mixed in origin. Cd contaminated 91% of the samples; the median content of Cd (1.4 mg kg−1) was three times the quality reference value for soil. The Cd contents of sugarcane fields exceeded the allowable limit (3.0 mg kg−1) for agricultural areas. The spatial variability of the metals in the RMR showed that metallurgy, cement production, vehicle exhaust and vehicular traffic were the main sources of metals in urban areas, while phosphate-based fertilizers were the main sources in rural areas. More than 80% of the metropolitan region surveyed in the study was at moderate to high ecological risk.

INTRODUCTION Alkaloids-derived drugs are a billionaire world-market and several phytochemical investigations aim the identification of new sources and/or structures. Thus, improving the way of extracting and methods to quantify them are of utmost importance. OBJECTIVE To quantify isoquinoline-derived alkaloids in Unonopsis duckei R.E. Fr. through a new validated high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) method in combination with a statistical mixture design that aimed a proper direct extraction of these compounds from leaves. METHODOLOGY Extracts were obtained with acetone, methanol, chloroform, and n-hexane in different combinations and proportions. Chemometrics were applied in order to compare peak areas, and therefore evaluate synergism and antagonism effects between the solvents. After selection of extraction solvent, the quantification was validated and applied in the best solvent combination to quantify the main alkaloids in U. duckei. RESULTS Chemometrics indicated a synergistic effect between chloroform and methanol solvents, thus improving alkaloid extraction and extract yield. Analytes were quantified in a 15-min method, with limits of detection (LODs) between 0.5 and 5.2 ng/mL and limits of quantification (LOQs) between 1.6 and 17.2 ng/mL. The accuracy ranged between 80 and 120%. Coefficients of variation were lower than 17.42% at all concentrations. Concentrations of the alkaloids in U. duckei varied from 6.79 to 131.10 μg/g of dried leaf and glaziovine was found to be the main compound. CONCLUSION The integration of simplex centroid model and quantification by HPLC-MS/MS is promising. Statistical optimisation of the alkaloid extraction and application of selective, sensitive and robust HPLC-MS/MS method will contribute to quality control applications in phytotherapeutic medicines.

The virtual humans behaviors can be endowed with different levels of intelligence and their action/motion can present more or less realism. In this scope, it is still a challenge to create, in an automatic and easy way, virtual humans that move and behave in a way that seems natural. Cultural aspects and population differences can produce deviations in speed, density and flow of the crowd. These aspects can be observed in videos of different Countries and certainly it can produce more realistic agents, if incorporated to simulation models. This paper presents a methodology to generate virtual humans which trajectories are based on real life video sequences, and in addition we considered Hofstede Cultural Dimensions (HCD) to map cultural differences. The method is tested in a set of real environments, but can be scaled for any environment that have video sequences and tracked human trajectories for training‥

This study investigated the efficiency of an organic tannin polymer alone or amended with polyacrylamide to harvest Chlorella vulgaris biomass grown in a laboratory-scale photobioreactor treating swine wastewater digestate. The effect of biomass concentration, tannin (TAN) dosages and changes in pH were evaluated in jar test experiments. Among the TAN concentrations tested (11, 22, 44, 89, 178 mg L−1), 11 mg L−1 showed the highest biomass recovery (97%). The highest coagulation/ flocculation efficiencies were obtained at pH 5 to 7. Flocculation efficiency improved from 50 to 97% concomitant with the increasing biomass concentrations from 45 to 165 mg L−1, respectively. Recovery efficiencies above 95% were achieved with the same TAN dosage (11 mg L−1) irrespective of the concentration of organic carbon present (75 to 300 mg TOC L−1). Overall, the results suggest that TAN could become an interesting alternative choice of non-toxic organic polymer for harvesting Chlorella sp. from organic-rich wastewater.

Biogas production from anaerobic biodegradation of livestock waste is a potential source of renewable energy. In addition to methane, biodegradation of this high-strength waste also produces sulfide that must be removed in order to prevent costly corrosive impacts on infrastructure. In this work, an anaerobic, phototrophic microbial community enriched from the native population in a swine waste lagoon was evaluated for its potential to remove sulfide from swine waste biogas. Batch experiments with the consortium attained removal efficiencies greater than 97% for sulfide concentrations above 1200 ppm. 16S rRNA gene sequencing revealed that the dominant population was most closely related to the isolate Azospirillum strain C5 (similarity index of 99%). Photomicrograph of the enriched consortium revealed the presence of cells with intracellular globules resembling sulfur storage. The enrichment of Azospirillum-like and the concomitant sulfide consumption suggest that this microorganism played an important role in sulfide removal in the bioreactor.

This work evaluated N dynamics that occurs over time within swine slurry composting piles. Real-time quantitative PCR (qPCR) analyzes were conducted to estimate concentrations of bacteria community harboring specific catabolic nitrifying-ammonium monooxygenase (amoA), and denitrifying nitrate- (narG), nitrite- (nirS and nirG), nitric oxide- (norB) and nitrous oxide reductases (nosZ) genes. NH3-N, N2O-N, N2-N emissions represented 15.4 ± 1.9%, 5.4 ± 0.9%, and 79.1 ± 2.0% of the total nitrogen losses, respectively. Among the genes tested, temporal distribution of narG, nirS, and nosZ concentration correlated significantly (p < 0.05) with the estimated N2 emissions. Denitrifying catabolic gene ratio (cnorB + qnorB)/ nosZ P 100 was indicative of N2O emission potential from the compost pile. Considering our current empirical limitations to accurately measure N2 emissions from swine slurry composting at field scale the use of these catabolic genes could represent a promising monitoring tool to aid minimize our uncertainties on biological N mass balances in these systems. 2013 Elsevier Ltd. All rights reserved.

For direct drive inertial confinement fusion, a capsule is imploded by directly illuminating the surface with laser light. Beam smoothing and uniformity of illumination affect the seeding of instabilities at the ablation front. We have developed a technique for studying the imprint of a laser beam on a thin foil using an x-ray laser as an extreme ultraviolet (XUV) backlighter. We use multilayer XUV optics to relay the x-ray laser onto the directly driven foil, and then to image the foil modulation onto a charged coupled device camera. This technique allows us to measure small fractional variations in the foil thickness. We have measured the modulation due to imprint from a low intensity 0.35 mu m drive beam incident on a 3 mu m Si foil using an yttrium x-ray laser on Nova. We present results from a similar technique to measure the imprinted modulation due to a low intensity 0.53 mu m drive beam incident on a 2 mu m Al foil using a germanium x-ray laser at the Vulcan facility. (C) 1997 American Institute of Physics.

Minimally invasive probe and optical biopsy system based on optical spectra recording and analysis seem to be a promising tool for early diagnostics of breast cancer. Light scattering and absorption spectra are generated continuously as far as the needle-like probe with one emitting and several collecting optical fibers penetrates through the tissues toward to the suspicious area. That allows analyzing not only the state of local site, but also the structure of tissues along the needle trace. The suggested method has the advantages of automated on-line diagnosing and minimal tissue destruction and in parallel with the conventional diagnostic procedures provides the ground for decision-making. 165 medical trials were completed in Nizhny Novgorod Regional Oncology Centre, Russia. Independent diagnoses were the results of fine biopsy and histology. Application of wavelet expansion and clasterization techniques for spectra analysis revealed several main spectral types for malignant and benign tumors. Automatic classification algorithm demonstrated specificity ∼90% and sensitivity ∼91%. Large amount of information, fuzziness in criteria and data noisiness make neural networks to be an attractive analytic tool. The model based on three-layer perceptron was tested over the sample of 29 ‘cancer’ and 29 ‘non-cancer’ cases and demonstrated total separation.

Objetivou-se avaliar a interação entre salinidade e o uso de biofertilizante bovino sobre a condutividade elétrica do solo, crescimento inicial, trocas gasosas e teores de elementos minerais no feijão-de-corda. O experimento foi conduzido em ambiente protegido do Departamento de Ciências dos Solos - UFC. A semeadura foi feita em vasos, utilizando-se, como substrato, um Argissolo Vermelho Amarelo. O experimento obedeceu a um delineamento inteiramente casualizado, em esquema fatorial 5 x 2, referente a cinco níveis de sais da água de irrigação e dois de biofertilizante bovino. O aumento dos níveis salinos da água de irrigação inibiu o crescimento inicial das plantas, sendo menos afetado no solo com o biofertilizante. O aumento da salinidade da água aliado à aplicação do biofertilizante, resultou no aumento da salinidade do solo. O aumento do teor salino da água de irrigação provocou redução nas trocas gasosas, mas em menor proporção nas plantas desenvolvidas nos tratamentos com o biofertilizante. A extração dos elementos essenciais e de sódio obedeceu a seguinte ordem: Ca > K > Na > P. A aplicação de biofertilizante bovino foi eficiente ao aumentar os teores de P na planta e de aumentar os totais extraídos de K, P e Ca, independente no nível de salinidade aplicado. Entretanto, os efeitos benéficos da aplicação de biofertilizante bovino sobre o crescimento, trocas gasosas e extração de nutrientes, são menos expressivos nos maiores níveis de salinidade da água de irrigação.

Objetivou-se avaliar a interação entre salinidade e o uso de biofertilizante bovino sobre a condutividade elétrica do solo, crescimento inicial, trocas gasosas e teores de elementos minerais no feijão-de-corda. O experimento foi conduzido em ambiente protegido do Departamento de Ciências dos Solos - UFC. A semeadura foi feita em vasos, utilizando-se, como substrato, um Argissolo Vermelho Amarelo. O experimento obedeceu a um delineamento inteiramente casualizado, em esquema fatorial 5 x 2, referente a cinco níveis de sais da água de irrigação e dois de biofertilizante bovino. O aumento dos níveis salinos da água de irrigação inibiu o crescimento inicial das plantas, sendo menos afetado no solo com o biofertilizante. O aumento da salinidade da água aliado à aplicação do biofertilizante, resultou no aumento da salinidade do solo. O aumento do teor salino da água de irrigação provocou redução nas trocas gasosas, mas em menor proporção nas plantas desenvolvidas nos tratamentos com o biofertilizante. A extração dos elementos essenciais e de sódio obedeceu a seguinte ordem: Ca > K > Na > P. A aplicação de biofertilizante bovino foi eficiente ao aumentar os teores de P na planta e de aumentar os totais extraídos de K, P e Ca, independente no nível de salinidade aplicado. Entretanto, os efeitos benéficos da aplicação de biofertilizante bovino sobre o crescimento, trocas gasosas e extração de nutrientes, são menos expressivos nos maiores níveis de salinidade da água de irrigação.The objective of this study was to evaluate the interaction between salinity levels of the water and the use of biofertilizer soil electrical conductivity of soil, initial growth, gas exchange and mineral content in cowpea plants. The experiment was performed conducted under greenhouse of the Department of Soil Science - UFC. The sowing of seeds was done in pots, using as a substrate Alfissol and two plants per pot. The experimental design was completely randomized in a 5 x 2 factorial, with 5 levels of salts and 2 levels of biofertilizer. The increase in salinity levels of irrigation water inhibited the initial growth of the plant, being less affected in the presence of biofertilizer. The high salinity combined with application of biofertilizer caused an increase in soil salinity. Increasing salinity of irrigation water caused reduction in gas exchange, being less affected by the presence of biofertilizer. The extraction of essential elements and sodium followed the order: Ca> K> Na> P. The application of biofertilizer was effective to increase the P concentration in plant and increase the total extracted K, Ca and P, regardless of salinity level applied. However, the beneficial effects of application of biofertilizer on growth, gas exchange and nutrient uptake, were less significant in the highest levels of irrigation water salinity.

In this work we report a first principles study of benzonitrile (BZN) interaction with pristine and Fe-doped single-walled carbon nanotubes (SWNTs), graphene, and C60. The results show that the BZN molecule weakly adsorbs on SWNTs, graphene, and C60 through π−π aromatic ring stacking. This interaction can be considerably strengthened by the inclusion of Fe atoms, which leads to a strong π−3d−π covalent bond linking the BZN to the carbon nanostructure. The calculated binding energy values suggest that the BZN molecule adsorption with Fe atoms is much stronger than those for Fe−SWNT, Fe−C60, or Fe−graphene interaction. Indeed, the BZN−Fe stability on each carbon nanostructure surface was studied and the SWNTs complexes are more stable than those of C60 and graphene.

The effect of HgI2 crystal encapsulation using different polymer resins, with the intent of avoiding the oxidation of the crystal surface, was evaluated in this work. The crystal was purified and grown by the physical vapor transport (PVT) technique modified. Systematic measurements were carried out for evaluating the stoichiometry, structure orientation, surface morphology and impurity of the crystal grown. The purer region of the crystal grown was selected to be prepared as a radiation detector, applying water-based conductive ink contacts and copper wire on the crystal surfaces. After that, the crystal was encapsulated with a polymeric resin which insulates atmospheric gases, aiming to improve the stability of the HgI2 detector. Four resins were used for crystal encapslation and the performance of the detector depended on the composition of the resins used. Among the four resins studied to evaluate the influence of encapsulation on the performance of crystals, as a radiation detector, the best result of resistivity and energy spectrum was obtained for the resin #3 (50% - 100% of Methylacetate and 5% - 10% of n-butylacetate). The encapsulation of crystals with polymer resins, performed with the intent of avoiding the oxidation of the crystal surface, did not compromise the measurements and were fully capable of detecting the presence of gamma radiation. The stability of the encapsulated HgI2 crystal detector was of up to 78 hs, while the stability found for HgI2 detector no encapsulated was in order 3 ~4 hs.

In this work, a systematic study of SO2 molecules interacting with pristine and transition metal (TM) covered C60 is presented by means of first principles calculations. It is observed that the SO2 molecule interacts weakly with the pristine C60 fullerene, although the resulting interaction is largely increased when the C60 structure is covered with Fe, Mn, or Ti atoms and the SO2 molecules are bounded through the TM atoms. The number of bounded SO2 molecules per TM atoms, in addition to the elevated binding energies per molecules, allows us to conclude that such composites can be used as a template for efficient devices to remove SO2 molecules or, alternatively, as SO2 gas sensor.

Industrial wastewaters are often contaminated by heavy metals, which can be very hazardous even at low concentrations. Several techniques for removing heavy metal ions have been used over the last century but their cost has usually been high, leading to the study of adsorption as a very promising, low-cost and simple process for metal removal in the last years. This study aims to investigate adsorption of mixed Cu 2+ and Zn 2+ ions on chemically treated Fluidgel clay, an alternative adsorbent, regarding kinetics and equilibrium aspects. Kinetic studies have shown a saturation time of the adsorbent of about 30 minutes. Kinetic curves were predicted by pseudofirst order and intraparticle diffusion models, while Langmuir and Langmuir-Freundlich bicomponent models have been adjusted to equilibrium data obtained at 293 K, 313 K and 333 K. Metal removal reached 75.8% for copper and 62.9% for zinc.

The optical reflectance of a strong shock front in water increases continuously with pressure above 100 GPa and saturates at ∼45% reflectance above 250 GPa. This is the first evidence of electronic conduction in high pressure water. In addition, the water Hugoniot equation of state up to 790 GPa (7.9 Mbar) is determined from shock velocity measurements made by detecting the Doppler shift of reflected light. From a fit to the reflectance data we find that an electronic mobility gap ∼2.5 eV controls thermal activation of electronic carriers at pressures in the range of 100–150 GPa. This suggests that electronic conduction contributes significantly to the total conductivity along the Neptune isentrope above 150 GPa.

Pesticides are used in large amounts in agriculture and the evaluation of their toxic effects is of major concern to public and environmental health. The aim of the present study was to investigate the genotoxic potential of a commercial formulation of the fungicide mancozeb by the micronucleus test in bone marrow and the comet assay in total blood of Wistar rats. Adult male Wistar rats were treated with a solution of mancozeb at a concentration of 40 mg/kg/day, administered intraperitoneally for 18 consecutive days, and compared to a control group. The results indicate that mancozeb induced significantly higher DNA damage as detected by the comet assay and increased the frequency of micronuclei. The results show that mancozeb is genotoxic and may adversely affect the DNA integrity of exposed organisms.

Laser-driven shocks have broken new ground in providing data on strongly coupled systems. One example is the measurements of the Hugoniot of hydrogen isotopes to over 300 GPa and the clear signature of metallic behavior at pressures of 60 GPa. The resulting fluid is strongly coupled (Γ > 10) and probably composed of ions, atoms, and molecules - a very difficult system to understand. The latest interpretation of these measurements is discussed. In addition, recent shock measurements on the hydrogen-bonded compound water - both EOS and reflectivity - are shown. The metallic signature for water is very different than that of hydrogen.

Simultaneous measurements of shock velocity and optical reflectance at 1064, 808, and 404 nm of a high pressure shock front propagating through liquid deuterium show a continuous increase in reflectance from below 10% and saturating at approximately (40-60)% in the range of shock velocities from 12 to 20mgr;m/ns (pressure range 17-50 GPa). The high optical reflectance is evidence that the shocked deuterium reaches a conducting state characteristic of a metallic fluid. Above 20mgr;m/ns shock velocity (50 GPa pressure) reflectance is constant indicating that the transformation is substantially complete.

We present experimental work exploring displacement and velocity interferometry as high spatial and temporal resolution diagnostics for measuring target preheat and the speed, planarity, and steadiness of a shock wave. A chirped pulse reflectometry experiment is also proposed as a frequency domain alternative for shock speed measurements. These techniques fill a need for high-precision diagnostics to derive accurate laboratory-based equation-of-state data at shock wave-driven pressures directly relevant to astrophysical systems. The performance of these optical laser probe techniques may exceed conventional passive techniques such as temporally streaked recording of optical emission upon shock breakout or side-on streaked X-ray radiography. Results from Nova laser and high-intensity ultrashort pulse experiments are presented.

A high-intensity laser was used to shock compress liquid deuterium to pressures between 0.22 and 3.4 megabars (Mbar). Shock density, pressure, and temperature were determined using a variety of experimental techniques and diagnostics. This pressure regime spans the transformation of deuterium from an insulating molecular fluid to an atomic metallic fluid. Data reveal a significant increase in compressibility and a temperature inflection near 1 Mbar, both indicative of such a transition. Single-wavelength reflectivity measurements of the shock front demonstrated that deuterium shocked above {approx}0.5 Mbar is indeed metallic. (c) 2000 The American Astronomical Society.

A laser self-focused channel formation into overdense plasmas was observed using a soft x-ray laser probe system with a grid image refractometry (GIR) technique. 1.053 {mu}m laser light with a 100 ps pulse duration was focused onto a preformed plasma at an intensity of 2x10{sup 17} W /cm{sup 2} . Cross sections of the channel were obtained which show a 30 {mu}m diameter in overdense plasmas. The channel width in the overdense region was kept narrow as a result of self-focusing. Conically diverging density ridges were also observed along the channel, indicating a Mach cone created by a shock wave due to the supersonic propagation of the channel front. (c) 2000 The American Physical Society.

A high intensity laser has been used to shock-compress liquid deuterium to pressures from 0.22 Mbar, near the upper end of gas-gun shock data, to 3.4Mbar. Using a variety of diagnostics, the densit...

We report on measurements of the equation of state and optical reflectivity at 1064 nm wavelength of a high pressure shock front propagating through a sample of liquid deuterium. We find that the shock front reflectivity increases from a low value (< 3.5%) to a saturation level of 65% in the pressure range of 0.22 - 0.55 Mbar. The pressure range where this metallization transformation takes place coincides with the pressure range where high compressibilities were observed on the principal Hugoniot.

A high-intensity laser was used to shock-compress liquid deuterium to pressures from 22 to 340 gigapascals. In this regime deuterium is predicted to transform from an insulating molecular fluid to an atomic metallic fluid. Shock densities and pressures, determined by radiography, revealed an increase in compressibility near 100 gigapascals indicative of such a transition. Velocity interferometry measurements, obtained by reflecting a laser probe directly off the shock front in flight, demonstrated that deuterium shocked above 55 gigapascals has an electrical conductivity characteristic of a liquid metal and independently confirmed the radiography.

A preliminary single-animal study of in vivo argon laser vascular welding was conducted using a canine model. The effects of temperature feedback control and saline drip cooling on patency and collagen cross-linking were investigated. The surface temperature at the centre of the laser spot was monitored using a two-colour infrared thermometer. The surface temperature was limited by either a saline drip or feedback control of the laser. Acute patency was evaluated and collagen cross-link assays were performed. Though both protocols yielded successful tissue fusion, welds maintained at a surface temperature of 50°C using feedback control had an elevated cross-link count compared to controls, whereas tissues irradiated without feedback control experienced a cross-link decrease. Simulations using the LATIS (LAser-TISsue) computer code suggest that drip-cooled procedures achieve significantly higher temperatures beneath the tissue surface than temperature feedback-controlled procedures. Differences between the volumetric heating associated with drip-cooled and feedback-controlled protocols may account for the different effects on collagen cross-links. Covalent mechanisms may play a role in argon laser vascular fusion.

Ultrashort laser pulse ablation removes material with low-energy fluence required and minimal collateral damage. The ultimate usefulness of this technology for biomedical application depends, in part, on characterization of the physical conditions attained, and determination of the zone of shockwave and heat-affected material in particular tissues. Detailed numerical modeling of the relevant physics (deposition, plasma formation, shockwave generation and propagation, thermal conduction) are providing this information. A wide range of time scales is involved, ranging from picosecond for energy deposition and peak pressure and temperature, to nanosecond for development of shockwave, to microsecond for macroscopic thermophysical response.

An optical feedback system for controlled precise tissue ablation is discussed. Our setup includes an ultrashort pulse laser (USPL), and a diagnostic system utilizing analysis of either tissue fluorescence or plasma emission luminescence. Current research is focused on discriminating hard and soft tissues such as bone and spinal cord during spinal surgery using either technique. Our experimental observations exhibit considerable spectroscopic contrast between hard and soft tissue, and both techniques offer promise for a practical diagnostic system.

A technique has been developed that allows the measurement of equations of state of low-atomic-number materials in regimes of extremely high pressure. Using this technique we have obtained absolute multimegabar measurements on the principal Hugoniots of low-Z solids, including data on polystyrene up to 40Mbar (60times the previous absolutely measured pressure) and beryllium at pressures up to 15Mbar. The polystyrene data were able to differentiate between existing theoretical models. The beryllium data confirm theoretical Hugoniots of several materials as high as 65Mbar. {copyright} {ital 1998} {ital The American Physical Society}

The objective is to find new materials for the fabrication of X-ray mirrors with high reflectance at 45 A wavelength, at normal incidence. We have examined multilayers of inconel and carbon, which have high theoretical reflectivities. Planar magnetron sputtering was used to fabricate mirror samples (period = 22.5 A) on silicon substrates. Our best 30-period inconel/carbon multilayers had a reflectivity of 0.3%, which was about a factor of 20 below the theoretical maximum (5.5%). Experimental details presented here include our use of an in situ ellipsometer to monitor the thickness of the layers and to provide information on the early stages of film growth and interdiffusion at the interfaces. Interdiffusion was found to occur at the carbon-on-inconel interface because of the rough underlying inconel layer, but not at the inconel-on-carbon interface because of the smooth underlying carbon layer. Interdiffusion at the carbon-on-inconel layer was also found to increase with the number of layers. The accuracy of ellipsometry for monitoring film thickness during deposition was limited by the theoretical model used for the optical constants of the film. As a result, we were not able to improve on the standard technique of ‘timing’ for control of layer thicknesses.