Characterization of Local and Systemic Impact of Whitefly (Bemisia tabaci) Feeding and Whitefly-Transmitted Tomato Mottle Virus Infection on Tomato Leaves by Comprehensive Proteomics.

Tomato mottle virus (ToMoV) is a single-stranded DNA (ssDNA) begomovirus transmitted to solanaceous crops by the whitefly species complex (Bemisia tabaci), causing stunted growth, leaf mottling, and reduced yield. Using a genetic repertoire of seven genes, ToMoV pathogenesis includes the manipulation of multiple plant biological processes to circumvent antiviral defenses. To further understand the effects of whitefly feeding and whitefly-transmitted ToMoV infection on tomato plants (Solanum lycopersicum 'Florida Lanai'), we generated comprehensive protein profiles of leaves subjected to feeding by either viruliferous whiteflies harboring ToMoV, or non-viruliferous whiteflies, or a no-feeding control. The effects of whitefly feeding and ToMoV infection were measured both locally and systemically by sampling either a mature leaf directly from the site of clip-cage confined whitefly feeding, or from a newly formed leaf 10 days post feeding (dpf). At 3 dpf, tomato's response to ToMoV included proteins associated with translation initiation and elongation as well as plasmodesmata dynamics. In contrast, systemic impacts of ToMoV on younger leaves 10 dpf were more pronounced and included a virus-specific change in plant proteins associated with mRNA maturation and export, RNA-dependent DNA methylation, and other antiviral plant processes. Our analysis supports previous findings and provides novel insight into tomato's local and systemic response to whitefly feeding and ToMoV infection.

Fracture Behavior of Bio-Inspired Functionally Graded Soft-Hard Composites Made by Multi-Material 3D Printing: The Case of Colinear Cracks.

The functional gradient is a concept often occurring in nature. This concept can be implemented in the design and fabrication of advanced materials with specific functionalities and properties. Functionally graded materials (FGMs) can effectively eliminate the interface problems in extremely hard-soft connections, and, thus, have numerous and diverse applications in high-tech industries, such as those in biomedical and aerospace fields. Here, using voxel-based multi-material additive manufacturing (AM, = 3D printing) techniques, which works on the basis of material jetting, we studied the fracture behavior of functionally graded soft-hard composites with a pre-existing crack colinear with the gradient direction. We designed, additively manufactured, and mechanically tested the two main types of functionally graded composites, namely, composites with step-wise and continuous gradients. In addition, we changed the length of the transition zone between the hard and soft materials such that it covered 5%, 25%, 50%, or 100% of the width (W) of the specimens. The results showed that except for the fracture strain, the fracture properties of the graded specimens decreased as the length of the transition zone increased. Additionally, it was found that specimens with abrupt hard-soft transitions have significantly better fracture properties than those with continuous gradients. Among the composites with gradients, those with step-wise gradients showed a slightly better fracture resistance compared to those with continuous gradients. In contrast, FGMs with continuous gradients showed higher values of elastic stiffness and fracture energy, which makes each gradient function suitable for different loading scenarios. Moreover, regardless of the gradient function used in the design of the specimens, decreasing the length of the transition zone from 100%W to 5%W increased the fracture resistance of FGMs. We discuss the important underlying fracture mechanisms using data collected from digital image correlation (DIC), digital image microscopy, and scanning electron microscopy (SEM), which were used to analyze the fracture surface.

Tratamiento antibacteriano de la meningitis neonatal (metaanálisis) (primera parte) / Antibacterial treatment of Neonatal Meningitis (metaanalysis) (part one)

Objetivo: Identificar los criterios de tratamiento antimicrobiano para meningitis bacteriana neonatal, publicados de 1967 a 1997. Diseño: metaanálisis. Material y método: revisión bibliográfica. Resultados: el tratamiento antimicrobiano empírico inicial debe estar dirigido contra organismos entéricos y no entéricos. La meta del tratamiento antimicrobiano para la meningitis neonatal (MN) es alcanzar concentraciones elevadas del antibiótico en LCR en comparación con la concentración mínima inhibitoria (CMI) del patógeno. Se debe repetir la punción lumbar 24 a 36 horas después del inicio del antibiótico hasta que se negativice el frotis. La administración intraventricular de aminoglucósido no siempre se asocia con una buena respuesta clínica o bacteriológica. En pacientes con válvula de derivación ventrículo-peritoneal se debe incluir tratamiento para S. aureus y S. epidermidis, además de un antibiótico que cubra a organismos gram-negativos. Las cefalosporinas de tercera generación son útiles cuando el agente causal es la Klebsiella u otro gram-negativo. En la última década son dos los esquemas antimicrobianos útiles en el tratamiento empírico inicial de la MN: uno incluye la asociación de ampicilina con un aminoglucósido y otro, la asociación de ampicilina con una cefalosporina de tercera generación (cefotaxima). La cefotaxima parece ser ideal; por su actividad antimicrobiana, su habilidad para cruzar la barrera hematoencefálica y su buena tolerancia, entre otras