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  • Author: A. Avila, x
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Abstract

Padina tetrastromatica Hauck was first reported from Pacific México by Setchell and Gardner nearly seventy years ago, and this record has been repeated by subsequent authors. This taxon was not found, however, either in recent collections or in investigations of herbarium material. Padina tetrastromatica differs from other species of Padina by having fewer rows of cells in the central portion of the thallus. The Setchell and Gardner record of P. tetrastromatica is representative of P. crispata Thivy. Padina tetrastromatica does not occur in Pacific México.

Summary

The radiohalogen, 124I, was produced by the 124Te(p,n) reaction from a glassy 124TeO2/6%Al2O3 melt on an 11 MeV proton cyclotron. A 20-degree inclined target withstands beam currents up to 20 μA with no physical damage to the substrate surface. Radioiodine was removed from the glassy melt by dry distillation techniques and trapped on cooled platinum wire. The radiochemical purity, determined by ion chromatography, shows a stable product in the iodide form over a lifetime of weeks.

Abstract

We consider a quasilinear equation of fourth order that models the mechanical vibrations of a marine riser. We study the nonexistence of global solutions for any real value of the initial energy. To this end, we construct a new invariant set and improve previous results.

Abstract

The present study is the first description of the egg morphology, embryonic development, and time required for hatching, and longevity of the oncomiracidium of Heterobothrium ecuadori (Meserve, 1938) Sproston, 1946. Experiments found that hatching time fluctuated between 7 and 10 days with a mean of 7.5 ± 1 days at 23 ± 1° C and 35 ‰. Eggs were provided with a polar filamentous appendage. The body of the oncomiracidium was flattened dorso-ventrally, 156 ± 9 μm long and 65 ± 8 μm wide. A full description of the egg development and morphology of the oncomiracidium is provided. The longevity of the oncomiracidia was 4–7 days at 21 ± 1°C, with a mean survival time of 121.8h. The ability to rear diclidophorids like H. ecuadori and to record precise information on their development provides valuable data for further studies.

Resumen

El término “biopsia líquida” se emplea en contraposición a la tradicional biopsia “sólida” de tejido. Esta técnica permite analizar y aislar el material tumoral presente en fluidos biológicos, lo cual podría abrir un amplio abanico de usos clínicos en el área de la oncología. Entre los fluidos biológicos se encuentran la sangre, la orina, la saliva, el líquido cefaloraquídeo (CSF), el líquido de derrame pleural o la bilis. En estas muestras biológicas se pueden aislar diversos analitos, de los cuales revisaremos los más relevantes en este trabajo: células tumorales circulantes (CTC), ADN tumoral circulante (ctDNA), proteínas, metabolitos y exosomas. Los biomarcadores que se analizarán dependen del analito, el tipo de tumor y la aplicación clínica, e incluyen mutaciones somáticas, deleciones, amplificaciones, fusiones génicas, marcas de metilación de ADN, miRNA específicos, proteínas y metabolitos. En esta revisión se ofrece una descripción general de las características de los analitos y las diferentes metodologías empleadas para su aislamiento. Así mismo, se describen las aplicaciones de la biopsia líquida en el manejo de los pacientes oncológicos, desde la detección temprana del cáncer a la monitorización de la repuesta a terapia en el cáncer avanzado. Finalmente, también se abordan las limitaciones y cuestiones aún por resolver en relación a esta herramienta.

Abstract

The term liquid biopsy is used in contraposition to the traditional “solid” tissue biopsy. In the oncology field it has opened a new plethora of clinical opportunities as tumor-derived material is shedded into the different biofluids from where it can be isolated and analyzed. Common biofluids include blood, urine, saliva, cerebrospinal fluid (CSF), pleural effusion or bile. Starting from these biological specimens several analytes can be isolated, among which we will review the most widely used: circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), circulating tumor RNA (ctRNA), proteins, metabolites, and exosomes. Regarding the nature of the biomarkers it will depend on the analyte, the type of tumor and the clinical application of the liquid biopsy and it includes, somatic point mutations, deletions, amplifications, gene-fusions, DNA-methylated marks, tumor-specific miRNAs, proteins or metabolites. Here we review the characteristics of the analytes and the methodologies used for their isolation. We also describe the applications of the liquid biopsy in the management of patients with cancer, from the early detection of cancers to treatment guidance in patients with advanced tumors. Finally, we also discuss some current limitations and still open questions.

Abstract

In chloride environments, reinforcement stress limits, intended to control flexural cracking, are one of the most important requirements for service limit state (SLS) design. However, concrete damage at the steel-concrete interface between bending cracks, so called cover-controlled cracking, is always correlated to areas of severe steel reinforcement corrosion. Based on the assumption that cover-controlled cracking should be limited, a model has been developed to provide alternative reinforcement stress limits in marine exposure conditions such as concrete in sea water, including permanently submerged, spray zone and tidal/splash zone, as well as coastal constructions located within 1 km of the shoreline. In this paper, the new reinforcement stress limitation is compared to the Australian Standards AS3600 concrete building code and AS5100.5 concrete bridge code provisions. Analysis shows that the new model is very sensitive to the reinforcement percentage of the cross-section. As a result, the existing AS3600 and AS5100.5 code provisions are more conservative than the new limitation for lightly to normally reinforced concrete cross-section. In this case, crack width control governs the SLS design. However, for normally to heavily reinforced concrete cross-section, the new model provides more conservative results suggesting that cover-controlled cracking governs the SLS design.