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Widely available and reliable testing for SARS-CoV-2 is essential for the public health response to the COVID-19 pandemic. We estimated the diagnostic performance of reverse transcription PCR (RT-PCR) performed on saliva and the SD Biosensor STANDARD Q antigen test performed on nasopharyngeal swab compared to the reference standard, nasopharyngeal swab (NP) RT-PCR. We enrolled participants living and/or seeking care in health facilities in North Lima, Peru from November 2020 to January 2021. Consenting participants underwent same-day RT-PCR on both saliva and nasopharyngeal swab specimens, antigen testing on a nasopharyngeal swab specimen, pulse oximetry, and standardized symptom assessment. We calculated sensitivity, specificity, and predictive values for the nasopharyngeal antigen and saliva RT-PCR compared to nasopharyngeal RT-PCR. Of 896 participants analyzed, 567 (63.3%) had acute signs/symptoms of COVID-19. The overall sensitivity and specificity of saliva RT-PCR were 85.8% and 98.1%, respectively. Among participants with and without acute signs/symptoms of COVID-19, saliva sensitivity was 87.3% and 37.5%, respectively. Saliva sensitivity was 97.4% and 56.0% among participants with cycle threshold (

Variations of the induced retardance in the aperture of liquid-crystal variable retarders LCVR and spatial light modulators LC-SLM are measured. It is found that the induced retardance, in LCVR, shows variations over the aperture which depend on the wavelength of the light used and the voltage applied. Larger retardance variations appear near to the edges of the cell. There are also larger variations in the maximum and minimum unwrapped retardances in the retardance versus voltage curves. These voltage values and the edges positions of the cells should be avoided in applications of these devices. On the other hand, the induced retardance is calculated pixel by pixel in LC-SLM. For the same gray level over the entire LC-SLM screen, there are differences in the induced retardance between pixels located in a central area and pixels located in the edges. For correct calibration of the LC-SLM, the retardance value as a function of gray level was determined, pixel by pixel.

We present a comparison of two experimental methods to measure retardance as a function of applied voltage and as a function of position over the aperture of liquid-crystal variable retarders. These measurements are required for many applications, particularly in polarimetry. One method involves the scan of an unexpanded laser beam over the aperture, and the other uses an expanded beam from a LED and a CCD camera to measure the full aperture with a single measurement. The first method is time consuming, is limited in the measured spatial resolution, and requires more expensive equipment to perform the scan, whereas the second method is low cost, with the spatial resolution of the CCD, and fast, but in principle has variations of the incident beam over the aperture that affect the measured retardance values. The results obtained show good agreement for the average values of retardance for the two methods, but the expanded-beam method shows more noise, particularly close to the voltage values at which the variable-retarder retardance versus voltage curves are unwrapped. These retardance variations can be reduced by smoothing the retardance image, which makes the expanded-beam method an attractive method for polarimetry applications since it gives the complete information in the full aperture of the device with the additional advantages of low cost, simplicity, and being less time consuming.

We present a comparison of the first numerical and experimental results for the scattering of light from rough surfaces using a recently developed variable coherence polarimetry source that permits obtaining information on the object without having to scan over incidence or scatter angle. We present, for the first time, we believe, the application of this source to a 1D rough surface and show how to analyze the scattered field to retrieve useful information about the surface. This source uses a liquid-crystal phase modulator to control the polarization as well as the coherence of the beam illuminating the rough surface. Changing the polarization state distribution at the source plane, by controlling the phase distribution on a spatial light modulator, gives a scan of two source spots over the rough surface. The scattered beam is analyzed with a Stokes polarimeter. The Kirchhoff approximation is used to calculate the scattered Stokes vector using the experimental incident Stokes vector and intensity distribution as a source. Good agreement is obtained between the numerical and experimental results, for a simple calculation of the number of intensity maxima obtained as the two first-order source spots are scanned across the sample.

Background Healthcare-associated infections (HAIs) have a major impact on public health worldwide. Particularly, hospital surfaces contaminated with bacterial pathogens are often the origin of both sporadic cases and outbreaks of HAIs. It has been demonstrated that copper surfaces reduce the microbial burden of high touch surfaces in the hospital environment. Here we report the antimicrobial characterization of a novel composite coating with embedded copper particles, named Copper Armour™. Methods The Copper Armour™ bactericidal activity was evaluated in in vitro assays against several bacterial pathogens, including Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli O157:H7 and Listeria monocytogenes. Additionally, its antimicrobial properties were also evaluated in a pilot study over a nine-week period at an adult intensive care unit. For this, four high touch surfaces, including bed rails, overbed table, bedside table and IV Pole, were coated with Cooper Armour™, and its microbial burden was determined over a nine-week period. Results Copper Armour™ coated samples showed an in vitro reduction in bacterial burden of > 99.9% compared to control samples. Moreover, pilot study results indicate that Copper Armour™ significantly reduces the level of microbial contamination on high-touch surfaces in the hospital environment, as compared with standard surfaces. Conclusions Based on its antimicrobial properties, Copper Armour™ is a novel self-sanitizing coating that exhibits bactericidal activity against important human pathogens and significantly reduces the microbial burden of hospital surfaces. This composite could be used as a self-sanitizing coating to complement infection control strategies in healthcare facilities.

In this paper, a compact optical system for generating arbitrary spatial light polarization patterns is demonstrated. The system uses a single high-resolution liquid crystal (LC) on silicon (LCOS) spatial light modulator. A specialized optical mount is designed and fabricated using a 3D printer, in order to build a compact dual optical architecture, where two different phase patterns are encoded on two adjacent halves of the LCOS screen, with a polarization transformation in between. The final polarization state is controlled via two rotations of the Poincaré sphere. In addition, a relative phase term is added, which is calculated based on spherical trigonometry on the Poincaré sphere. Experimental results are presented that show the effectiveness of the system to produce polarization patterns.

Nowadays, digital holographic systems are based on two main optical schemes: off-axis (OA) and inline (IL) holographic systems. In OA set-ups, the reference and the object beams present a relative angle at the registration plane. Thus, a real image of the object can be obtained without the influence of conjugated images by performing a spatial filtering at the reconstructed plane. IL configurations are less sensitive to vibrations and air flows than OA configurations, but the undesired influence of conjugated images in the final hologram is not avoided. To overcome this limitation, a number of IL based methods have been proposed. One interesting approach is the phase-shifting technique, which leads to efficient holograms for IL applications. However, due to the time-sequential nature of this technique, it is somewhat inappropriate for dynamic processes. We present a new method, for IL digital holography, based on a doublesideband (DSB) filter. This method not only removes the conjugate images in the reconstruction process but also reduces the distortions that usually appear when using single-sideband filters. Moreover, it is only time-limited by the acquisition time of the CCD camera. The appropriateness of the technique to be applied in dynamic processes was tested for the tracking of micro-particles. To this aim, particle holographic images were obtained by using the DSB method and afterwards processed with digital picture recognition methods, this allowing us to accurately track the spatial position of the particles. By using this approach, the instantaneous trajectory and velocity described by glass microspheres in movement were experimentally determined

We propose two different in-line optical schemes for the implementation of Biaxial Crystal (BC) based polarimeters. Unlike already existing BC polarimeters prototypes, our proposed architectures only require of a single BC and only one CCD camera, this leading to more feasible and cheaper prototypes. The first scheme is restricted to linear metrology and we provide its interest to be applied under low-intensity conditions. The second architecture is suitable for complete polarimetry, this being achieved by including an optical module to properly split and steer the input light. The BC polarimeters were implemented and tested by measuring different known input polarizations and we obtained excellent results in terms of accuracy and repeatability.

The geographic origins of populations can be identified by their maternally inherited mitochondrial DNA (mtDNA) haplogroups. This study compared human cybrids (cytoplasmic hybrids), which are cell lines with identical nuclei but mitochondria from different individuals with mtDNA from either the H haplogroup or L haplogroup backgrounds. The most common European haplogroup is H while individuals of maternal African origin are of the L haplogroup. Despite lower mtDNA copy numbers, L cybrids had higher expression levels for nine mtDNA-encoded respiratory complex genes, decreased ATP (adenosine triphosphate) turnover rates and lower levels of reactive oxygen species production, parameters which are consistent with more efficient oxidative phosphorylation. Surprisingly, GeneChip arrays showed that the L and H cybrids had major differences in expression of genes of the canonical complement system (5 genes), dermatan/chondroitin sulfate biosynthesis (5 genes) and CCR3 (chemokine, CC motif, receptor 3) signaling (9 genes). Quantitative nuclear gene expression studies confirmed that L cybrids had (a) lower expression levels of complement pathway and innate immunity genes and (b) increased levels of inflammation-related signaling genes, which are critical in human diseases. Our data support the hypothesis that mtDNA haplogroups representing populations from different geographic origins may play a role in differential susceptibilities to diseases.

Purpose Smoking is a risk factor in the development of a variety of neuroretinal diseases. Therefore, we have investigated the effects of hydroquinone (HQ), a toxicant that is present in high concentrations in cigarette smoke, on a human retinal Muller cell line (MIO-M1). Methods MIO-M1 cells were treated for 24 h with four different concentrations of HQ (200 μM, 100 μM, 50 μM, and 25 μM). Assays were used to measure cell viability, reactive oxygen/nitrogen species (ROS/RNS), mitochondrial dehydrogenase activity (WST assay), caspase-3/7 activity and lactate dehydrogenase (LDH) levels. Western blot analyses with anti-LC3 and anti-GAPDH antibodies were performed on HQ-treated samples. Some cultures were treated with 4 μM rapamycin, to induce autophagy, with and without the autophagy inhibitor 3-methyl-adenine (3MA), and levels of ROS/RNS and LDH were measured. Results Our findings show that HQ reduced cell viability at four different concentrations tested (200, 100, 50 and 25 μM); decreased mitochondrial function at concentrations of 200 and 100 μM; increased ROS/RNS activity at all the concentrations tested and increased LDH levels at concentrations of 200, 100 and 50 μM. Caspase-3/7 activities were not modified by HQ. However, treatment of these cells with this agent resulted in the appearance of the autophagy associated LC3-II band. Pre-treatment with 3MA reduced the ROS/RNS and LDH levels of the HQ-treated and rapamycin-treated cells. Conclusion Our study suggests that HQ damages the MIO-M1 cells through oxidative, mitochondrial and autophagic pathways and not caspase-related apoptosis.

We present the continuous scan operation of the ALBA-NOM as a working mode that allows obtaining low noise in short time, as well as high accuracy measurements. In the traditional step-scan operation, the position of the probe beam is kept fixed while many data points of autocollimator are averaged for noise reduction. This operation mode is very safe, as one has a perfect correspondence between mirror position and measured angle, but it is time inefficient, as it disregards all the data values acquired during motion, and basically averages data values taken under identical conditions. On the other hand, continuous scan is less safe in terms of correspondence between mirror position and slope, especially for NOM systems for which the autocollimator does not accept an electronic trigger. Nevertheless, it is possible to perform independent acquisitions of the autocollimator and of the linear stage data during a scan, and synchronize signals a posteriori. This solves the main problem of continuous scan with a NOM. Continuous scan operation for performing measurements is very efficient for noise reduction per unit time, as it allows integrating every single data value taken by the autocollimator. In addition, it opens the possibility of introducing pitch variations of the mirror between scans. This allows obtaining many independent datasets that can be combined using error suppression techniques to reduce not just noise but systematic errors too. In this paper we report the methods and the main results.

Several methods to control the polarization state and the Degree of Polarization of a beam are proposed. Also a method to generate a beam with an arbitrary polarization distribution by using a parallel aligned Liquid Crystal display is shown.

We present two optical arrangements for the implementation of polarimeters based on the conical refraction phenomenon, occurring on biaxial crystals (BC). The proposed set-ups keep all the benefits related to BC based polarimeters, but decrease costs and complexity when compared with existing alternatives. Whereas one of the proposals allows us to perform linear polarization metrology, the second proposal is suitable to perform complete polarimetry. The two proposed schemes were optimized, experimentally implemented, and tested by measuring different known input polarizations. The obtained results provide their suitability to be applied for polarization metrology.

The degree of asphericity is estimated by determining the average radius of curvature in different sections, at various points on the surface of a sphere, and the deviation from it. We employ the vectorial shearing interferometer (VSI) as the instrument to determine the radius of curvature from two subapertures of the transparent glass sphere. We incorporate the sphere as a thick lens into the interferometric setup, illuminating it with an expanded beam. The spherical aberration, introduced by the sphere in the wave front, depends on the local sphere radius, on the refraction index of the glass, and on the cone angle of the source. The wave front aberrated by the sphere impinges on the VSI. Here, the wave front is divided in two in amplitude, it is sheared vectorially, and it is superimposed with itself. The fringe pattern is formed in the intersection of the wave fronts. The shape of the resulting fringe pattern is directly related to spherical aberration. We estimate qualitatively the degree of asphericity, comparing the phase gradients in different sections of the sphere. Here, we report on the experimental setup to test the asphericity, the results with different vectorial shearing (magnitude and direction). Finally, we perform a comparison with the theoretical predictions.

We describe a wave-front displacement system using a novel configuration of a pair of wedge prisms. The wave-front propagation, through the displacement system, is analyzed using the exact ray trace. The main advantage, of this configuration, is that the shearing (direction and magnitude) is constant from the displacement system to the image plane. The direction of the shearing depends on the relative orientation of the prisms. The magnitude of the shearing is proportional to the distance between prisms. The proportionality constant depends on the wedge angle and the material of fabrication of the prisms, and it gives the sensitivity to the displacement of the system. The deviation of the shearing due to the difference between the wedge angles is larger than that the produced by the oblique incidence of the wave-front. The experimental results confirm the theoretical data.

Due to the increasing interest of polarimetric information in numerous applications, different Stokes polarimeter designs are provided in the literature for the measure of light beam polarization. Recently, the concept of polarimeters based on the conical refraction (CR) phenomenon, occurring in biaxial crystals, was proposed. CR polarimeters are snapshot polarimeters that allow controlling the volume of data redundancy without an increase in the acquisition time. We present the implementation, calibration, and analysis of an incomplete CR-polarimeter optimized for the measure of linear polarizations. A simpler and cheaper experimental configuration is achieved, if compared with other polarimeters proposed in the literature. The suitability of the polarimeter is experimentally demonstrated and some of its benefits, such as its performance in low-intensity conditions, are discussed.

On the 20th of December 2013, The United Nations (UN) General Assembly 68th Session proclaimed 2015 as the International Year of Light and Light-based Technologies (IYL 2015). The proclamation of an International Year focusing on the light science and applications recognizes the importance of light in the society, which plays a vital role in our daily lives, being visible in a widespread number of different areas, as for instance, in technology, education, energy, art, agriculture, health, among many others. In this work, the members of the Image Processing Laboratory from the Universitat Autonoma de Barcelona (UAB), analyze the concept of readapting some experiments in optics -usually conducted in different courses at the UAB physics degree- into the artistic context of the MACBA (Museu d’Art Contemporani de Barcelona). This project, called SummerLight, takes place within the framework of the IYL, as part of the activities devised to promote the visibility of light. The readapted experiments are expected to teach and improve the knowledge of high school students with respect to different important physical phenomena related to the wave nature of light as polarization, interferences and diffraction. This study analyzes the suitability of the proposed experiments in terms of student optical skills improvement. In addition, its contextualization into an artistic scenario is also discussed.

This Letter proposes a new optical architecture based on a double-sideband filter, simultaneously applied at the Fourier plane, for inline digital holography. The proposed architecture not only allows removal of the conjugate images in the reconstruction process but also reduces the distortions that usually appear when using a single-sideband filter. We first introduce the mathematical model that explains the method and then describe the optical setup used for the implementation. The optical system includes a parallel aligned liquid crystal display placed at the Fourier plane that simultaneously filters positive and negative frequencies, when properly combined with linear polarizers. This feature makes the device useful to register dynamic processes. Finally, we tested the setup by registering a holographic movie of microscopic moving objects placed at different planes. Fil: Ramirez, Claudio. Universitat Autònoma de Barcelona; España Fil: Lizana, Ángel. Universitat Autònoma de Barcelona; España Fil: Iemmi, Claudio César. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Campos, Juan. Universitat Autònoma de Barcelona; España

An optical setup able to generate arbitrary states of polarization (SOPs) with customized degree of polarization is presented in this Letter. Compared with the few alternatives existing in literature, it presents an easy-to-build optical setup and leads to a superior performance. In fact, experimental results are presented, providing an accurate control for the generation of SOPs (maximum error of 1.7% and 3.3% for ellipticity and azimuth, respectively) as well as for the associated degree of polarization (full experimental variation from 1 up to 0.003, with a 1.7% maximum error). The system proposed may be useful for different applications, for example, for polarimeters testing, speckle metrology, and biological applications.

Liquid Crystals on Silicon (LCOS) displays are a type of LCDs that work in reflection. Such devices, due to the double pass that the light beam performs through the LC cells, lead to larger phase modulation than transmissive LCDs with the same thickness. By taking advantage of this modulation capability exhibited by LCOS displays, we propose a new experimental set-up which is able to provide customized state of polarization spatial distributions just by means of a single LCOS display. To this aim, a double reflection on different halves of the display is properly performed. This fact is achieved by including a compact optical system that steers the light and performs a proper polarization plane rotation. The set-up has been experimentally implemented and some experimental concerns are discussed. The suitability of the system is provided by generating different experimental spatial distributions of polarization. In this regard, well-known polarization distributions, as axial, azimuthal or spiral linear polarization patterns are here provided. Based on the excellent results obtained, the suitability of the system to generate different spatially variant distributions of polarization is validated.

The technology of liquid crystal panels (LCP) is very mature and can be applied in many different areas in which the modulation of an input light beam is needed. LCP can be used to modulate amplitude, phase or polarization state of the input beam, being the phase modulation the most important. For this reason parallel aligned LCP are the most recommended for most applications. In this paper we review a method for the characterization of these devices, especially when temporal fluctuations are present. Next we revise several applications in different fields: a) A point diffraction interferometer with phase shifting capabilities is demonstrated and applied to the recording of digital holograms that can focus, digitally, the different planes of a 3D object; b) Different techniques to obtain superresolution imaging beyond the diffraction limit of the aperture, or the geometrical limitation imposed by the pixilation of the CCD device are shown, and c) the construction of Stokes and Mueller polarimeters with different types of LCP are also shown.

A polarimetry based method able to characterize optical properties of linear Liquid Crystal Displays (LCDs), even in presence of time-fluctuations of the phase, is proposed in this work. In particular, mean linear retardance, Liquid Crystal (LC) fast axis orientation and phase fluctuation amplitude of LCDs can be obtained with the proposed alternative technique. This technique enables to achieve these important features of LCDs with a set-up significantly less complicated to build up and with faster measurements than previously proposed techniques, which are based on diffraction or interferometry experiments. The validity of the technique is tested by measuring two different LCDs: one monopixel PA-LC panel working in transmission and a reflective PA-LCoS display. The technique provides similar results than those obtained by using previously proposed methods, confirming the validity of our alternative technique.

To evaluate the effects of Triesence® (TRI), a new preservative-free triamcinolone approved by the U.S. Food and Drug Administration (FDA) for intraocular use, on human retina pigment epithelial (ARPE-19) and rat neurosensory (R28) cells in culture.ARPE-19 and R28 cell cultures were treated 24 h with 1,000, 500, 200, or 100 μg/mL of crystalline (cTRI) or 1,000, 500, or 200 μg/mL of solubilized (sTRI). TRI was solubilized by centrifuging the drug, discarding the supernatant containing the vehicle and then resuspending the drug pellet in an equivalent amount of Dimethyl sulfoxide to achieve the same concentration as the commercial preparation. Percentage of cell viability (CV) was evaluated by a trypan blue dye-exclusion assay. The mitochondrial membrane potential (ΔΨm) was analyzed with the JC-1 assay. The caspase-3/7 activity was measured by a fluorochrome assay.In the ARPE-19 cultures, the cTRI caused a decrease in CV at 1,000 μg/mL (13.03±6.51; P0.001), 500 μg/mL (28.87±9.3; P0.001), 200 μg/mL (54.93±5.61; P0.001), and 100 μg/mL (82.53±0.65; P0.005) compared with the untreated controls (96.98±0.16). In R28 cultures, the cTRI treatment also reduced CV values significantly (P0.001) for the 1,000 μg/mL (22.73±2.44), 500 μg/mL (34.63±1.91), 200 μg/mL (58.70±1.39), and 100 μg/m (75.33±2.47) compared with the untreated controls (86.08±3.54). Once the TRI was solubilized (sTRI), the CV and ΔΨm remained similar to the untreated controls for both ARPE-19 and R28 cells. The sTRI treatment with 1,000, 500, and 200 μg/mL increased in caspase-3/7 activity in ARPE-19 cells (P0.01) and in R28 cells (P0.05) compared with dimethyl sulfoxide equivalent controls.The crystalline form of TRI (cTRI) can cause a significant decrease in CV to cultured retinal cells. Once the TRI is solubilized (sTRI), at the same concentrations, the cells remain viable with no decrease in CV or ΔΨm. The sTRI can, however, increase caspase-3/7 activity, thus suggesting some degree of apoptosis.

We examine the viability of implementing the Vectorial Shearing Interferometer (VSI) in order to determine the sphericity of a glass standard patron. We use the patron sphere as an optical component to collimate the expanded wave front of a laser. The collimated wave front impinges on the VSI. The resulting fringe pattern carries the phase gradient information of the original wave front, in the sheared direction. We estimate qualitatively the asphericity of the element under test, comparing the phase gradients in different sections of the sphere. When the gradients of two or more directions are identical, we consider that the standard patron has uniform sphericity. Here, we report on the experimental setup to test the asphericity, the experimental results, and perform comparison with theoretical calculations.

The shearing interferometry is an alternative technique for assessment and measurement of wave-front aberrations. The vectorial shearing interferometer uses a displacement system to shear a wave front in vectorial form. We describe the wave-front displacement system incorporating a novel configuration of a pair of wedge prisms. Its main advantage is that the shearing is constant from the displacement system to image plane. The shear direction depends of the relative orientation of the prisms. The magnitude of the shearing is proportional to the distance between prisms. The proportionality constant depends of the wedge angle and the material of the prisms. This constant gives the sensibility to the displacement of the system. We describe and analyze the wave-front propagation through the displacement system using the exact ray trace. The deviation of the shearing by the difference in the wedge angles is larger than the produced by the oblique incidence of the wave front. Finally, we compare experimental results with exact ray trace simulations. We observe that the theoretical data corresponds to the experimental results. There is a maximum rms error of ≈ 10 μm.

We use the modulation transfer function (MTF) to evaluate the performance of several multi-aperture interferometric configurations for the detection of a faint planet in the vicinity of its bright star. We design non-redundant interferometric layouts that provide satisfactory coverage of the spatial frequencies of interest. We propose a design incorporating a rotating, rotationally shearing interferometer in a gravity-free environment. The side peak of its MTF may be centered on the spatial frequency associated with likely planet coordinates, resulting in the planet signal enhancement and isolation.

In this work a novel point diffraction interferometer based on a variable liquid crystal wave plate (LCWP) has been implemented. The LCWP consists of a 3x3 cm2 monopixel cell with parallel alignment. The monopixel cell was manufactured such that the electrode covers the entire surface except in a centered circular area of 50 μm of diameter. This circle acts as a point perturbation which diffracts the incident wave front giving rise to a spherical reference wave. By applying a voltage to the LCWP we can change the phase of the wave front that passes through the monopixel, except at the center. Phase shifting techniques are used in order to calculate the amplitude and phase distribution of the object wave front. The system allows a digital hologram to be obtained, and by using the Fresnel diffraction integral it is possible to digitally reconstruct the different planes that constitute the three dimensional object. Fil: Ramírez, Claudio. Universidad Autónoma de Barcelona. Departamento de Física; España Fil: Otón, Eva. Universidad Politécnica de Madrid. Escuela Técnica Superior de Ingenieros de Telecomunicación. Centro de Materiales y Dispositivos Avanzados para Tecnologías de Información y Comunicaciones; España Fil: Iemmi, Claudio Cesar. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Procesado de Imágenes; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria; Argentina Fil: Moreno, Ignacio. Universidad Miguel Hernández. Departamento de Ciencia de Materiales, Óptica y Tecnología Electrónica; España Fil: Bennis, Noureddine. Universidad Politécnica de Madrid. Escuela Técnica Superior de Ingenieros de Telecomunicación. Centro de Materiales y Dispositivos Avanzados para Tecnologías de Información y Comunicaciones; España Fil: Otón, José Manuel. Universidad Politécnica de Madrid. Escuela Técnica Superior de Ingenieros de Telecomunicación. Centro de Materiales y Dispositivos Avanzados para Tecnologías de Información y Comunicaciones; España Fil: Campos, Juan. Universidad Autónoma de Barcelona. Departamento de Física; España

PURPOSE To study the inhibitory effects of some agents or drugs (inhibitors) on benzo(e)pyrene (B(e)P)-induced cell death and apoptosis on human retinal pigment epithelial (ARPE-19) cells in vitro. METHODS ARPE-19 cells were pretreated with varying concentrations of different classes of inhibitors (calpain, benzyl isothiocyanate [BITC], simvastatin, epicatechin, genistein, resveratrol, and memantine) before B(e)P exposure. Cell viability (CV) was determined by a trypan blue dye-exclusion assay. Caspase-3/7 and caspase-9 activities were measured by fluorochrome assays. The production of reactive oxygen/nitrogen species (ROS/RNS) was measured with 2',7'-dicholorodihydrofluorescein diacetate dye assay. RESULTS At 30-microM concentrations, the genistein, resveratrol, and memantine inhibitors were able to reverse significantly the loss of cell viability, the activation of caspase-3/7 and caspase-9, and the production of ROS/RNS in ARPE-19 cell cultures. Memantine was the most potent and genistein was the least effective inhibitor in blocking the B(e)P-induced effects. Calpain, BITC, simvastatin, and epicatechin did not reverse the loss of cell viability in B(e)P-treated ARPE-19 cells. As a matter of fact, at the concentrations studied (15, 30, 45 microM), the BITC plus B(e)P-treated cultures showed significantly lower cell viability than the B(e)P-treated culture alone, suggesting BITC-related toxicity. CONCLUSIONS Genistein, resveratrol, and memantine can reverse the apoptosis and oxidant production generated by B(e)P, a toxic element of smoking. These inhibitors may be beneficial against retinal diseases associated with the loss of RPE cells.

The construction of Port Angamos terminal 1 in Mejillones Bay, Chile, required the dredging of 1,200,000 m³ of sediment from depths of 2?20 m. The effects of dredging on macrobenthic faunal communities are due to chemical (organic material) and physical (granulometric) alterations of the environment and are variable depending on the specific conditions of the intervened area. This study uses descriptive statistics to determine the impacts of dredging on benthic macrofaunal communities. Dredging caused alterations of the physical environment which were reflected in the benthic communities which showed reduced richness, abundance, biomass and diversity, as well as diminished community complexity, in the study sites closest to the port.

• A prospective, randomized, double-blind, multicenter study was conducted of hospitalized patients to compare the efficacy and safety of oral ciprofloxacin (dosage, 750 mg every 12 hours) with intravenous cefotaxime (dosage, 2.0 g every 8 hours) as monotherapy for difficult skin and skin structure infections requiring hospitalization. Five hundred seventy patients were assessed for an analysis of safety and 461 patients were assessed for an analysis of efficacy. The most common infections were infected ulcers and abscesses. At the end of therapy, there was a higher incidence of recurrent or persistent organisms in the cefotaxime group compared with ciprofloxacin. Adverse reactions related to either therapy were rare. By pathogens, there were no differences in activity, except the higher rate of recurrent or persistentPseudomonas aeruginosainfection in the cefotaxime group. By diagnosis, the two drugs had comparable efficacy, except for the higher incidence of bacteriologic failure in patients with polymicrobial infected ulcers in the cefotaxime group. Larger studies are needed to evaluate emergence of resistance to ciprofloxacin. Oral ciprofloxacin therapy is as safe and effective as parenteral cefotaxime in the treatment of difficult infections of the skin and skin structure, and affords the prospect of early discharge from the hospital and significant cost savings. (Arch Intern Med. 1989;149:2579-2583)