Characterization and simulation of soft gamma-ray mirrors for their use with spent fuel rods at reprocessing facilities.

The use of a grazing incidence optic to selectively reflect K-shell fluorescence emission and isotope-specific lines from special nuclear materials is a highly desirable nondestructive analysis method for use in reprocessing fuel environments. Preliminary measurements have been performed, and a simulation suite has been developed to give insight into the design of the x ray optics system as a function of the source emission, multilayer coating characteristics, and general experimental configurations. The experimental results are compared to the predictions from our simulation toolkit to illustrate the ray-tracing capability and explore the effect of modified optics in future measurement campaigns.

Idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is the most common fibrosing lung disease. It is associated with a very poor prognosis. Treatments can delay the progression of IPF, so early diagnosis is fundamental. Radiologists play a fundamental role in the evaluation and accurate diagnosis of IPF. Identifying the characteristic patterns of IPF on high-resolution computed tomography (HRCT) is key in the process of multidisciplinary diagnosis, often obviating the need for surgical lung biopsies. This review describes and illustrates the clinical and imaging findings in IPF in the context of the most recent international guidelines, as well as the differential diagnosis and the role of HRCT in follow-up and assessment of complications.

Alternating Polistes-Vespula venom immunotherapy: a therapeutic strategy to resolve a diagnostic deficiency.

BACKGROUND: In Mediterranean regions, double sensitization to Polistes and Vespula species is frequent in patients reacting to an unidentified wasp sting. Since both genera are present, it is often difficult to determine which insect is responsible and, consequently, select venom for immunotherapy. When a specific diagnosis cannot be made, a new therapeutic strategy should be undertaken. METHODS: We performed a case-control study in which 37 patients who were allergic to venom from Vespula and Polistes species received a 3-year schedule of alternating immunotherapy. Twenty monosensitized patients (10 to Vespula and 10 to Polistes) received conventional venom immunotherapy (VIT) during the same period. All 57 patients received the same number of injections. The effectiveness of VIT was assessed by means of re-sting, which was performed yearly. Serum specific immunoglobulin (Ig) E and IgG4 were also studied, RESULTS: All the cases tolerated all the stings. One control patient developed a mild systemic reaction after the first-year Vespula sting but tolerated subsequent re-stings. Both cases and controls reached significant changes in levels of IgE and IgG4 after VIT (P < .04 at minimum). The cases developed a response as expected, although this was less intense than in the control group. In the Polistes control subgroup, sIgE to Polistes decreased to under baseline levels, after a marked initial increase; this decrease was not observed in the Vespula subgroup. CONCLUSION: An alternating VIT strategy is appropriate and provides protection to patients sensitized to Vespula and Polistes.

Spatially multiplexed dark-field microspectrophotometry for nanoplasmonics.

Monitoring the effect of the substrate on the local surface plasmon resonance (LSPR) of metallic nanoparticles is key for deepening our understanding of light-matter interactions at the nanoscale. This coupling gives rise to shifts of the LSPR as well as changes in the scattering pattern shape. The problem requires of high-throughput techniques that present both high spatial and spectral resolution. We present here a technique, referred to as Spatially Multiplexed Micro-Spectrophotometry (SMMS), able to perform polarization-resolved spectral and spatial analysis of the scattered light over large surface areas. The SMMS technique provides three orders of magnitude faster spectroscopic analysis than conventional dark-field microspectrophotometry, with the capability for mapping the spatial distribution of the scattered light intensity with lateral resolution of 40 nm over surface areas of 0.02 mm(2). We show polarization-resolved dark-field spectral analysis of hundreds of gold nanoparticles deposited on a silicon surface. The technique allows determining the effect of the substrate on the LSPR of single nanoparticles and dimers and their scattering patterns. This is applied for rapid discrimination and counting of monomers and dimers of nanoparticles. In addition, the diameter of individual nanoparticles can be rapidly assessed with 1 nm accuracy.

How two-dimensional bending can extraordinarily stiffen thin sheets.

Curved thin sheets are ubiquitously found in nature and manmade structures from macro- to nanoscale. Within the framework of classical thin plate theory, the stiffness of thin sheets is independent of its bending state for small deflections. This assumption, however, goes against intuition. Simple experiments with a cantilever sheet made of paper show that the cantilever stiffness largely increases with small amounts of transversal curvature. We here demonstrate by using simple geometric arguments that thin sheets subject to two-dimensional bending necessarily develop internal stresses. The coupling between the internal stresses and the bending moments can increase the stiffness of the plate by several times. We develop a theory that describes the stiffness of curved thin sheets with simple equations in terms of the longitudinal and transversal curvatures. The theory predicts experimental results with a macroscopic cantilever sheet as well as numerical simulations by the finite element method. The results shed new light on plant and insect wing biomechanics and provide an easy route to engineer micro- and nanomechanical structures based on thin materials with extraordinary stiffness tunability.

Mass and stiffness spectrometry of nanoparticles and whole intact bacteria by multimode nanomechanical resonators.

The identification of species is a fundamental problem in analytical chemistry and biology. Mass spectrometers identify species by their molecular mass with extremely high sensitivity (<10-24 g). However, its application is usually limited to light analytes (<10-19 g). Here we demonstrate that by using nanomechanical resonators, heavier analytes can be identified by their mass and stiffness. The method is demonstrated with spherical gold nanoparticles and whole intact E. coli bacteria delivered by electrospray ionization to microcantilever resonators placed in low vacuum at 0.1 torr. We develop a theoretical procedure for obtaining the mass, position and stiffness of the analytes arriving the resonator from the adsorption-induced eigenfrequency jumps. These results demonstrate the enormous potential of this technology for identification of large biological complexes near their native conformation, a goal that is beyond the capabilities of conventional mass spectrometers.

Fiber-based photon-pair source capable of hybrid entanglement in frequency and transverse mode, controllably scalable to higher dimensions.

We have designed and implemented a photon-pair source, based on the spontaneous four wave mixing (SFWM) process in a few-mode fiber, in a geometry which permits multiple, simultaneous SFWM processes, each associated with a distinct combination of transverse modes for the four participating waves. In our source: i) each process is group-velocity-matched so that it is, by design, nearly-factorable, and ii) the spectral separation between neighboring processes is greater than the marginal spectral width of each process. Consequently, there is a direct correspondence between the joint amplitude of each process and each of the Schmidt mode pairs of the overall two-photon state. Our approach permits hybrid entanglement in discrete frequency and in transverse mode, whereby control of the number of supported fiber transverse modes allows scalability to higher dimensions while spectral filtering may be used for straightforward Schmidt mode discrimination.

Flow-injection analysis with multidetection as a useful technique for metal speciation.

The analytical potential of a closed flow-injection system with multidetection by a single detector (for calculation of rate constants, reaction rate, dilution and amplification methods, etc.) is extended to simultaneous determinations for chromium speciation, with injection of the reagent(s) into the sample solution (which acts as the carrier).

Determination of ethanol in human fluids--I. Determination of ethanol in blood.

A review of the methods for determination of ethanol in human fluids is presented. This first part of the review deals with the methods for determination of alcohol in blood, which have been divided into chemical, enzymatic, chromatographic and miscellaneous for clearer exposition and discussion.

Determination of ethanol in human fluids--II. Determination of ethanol in urine, breath and saliva.

A review is presented to continue with a previous one in which the methods for determination of ethanol in urine, breath and saliva are surveyed.

Enzymatic determination of ethanol in saliva by flow injection analysis.

Enzymatic photometric and fluorimetric methods are proposed for the determination of ethanol in saliva with determinative ranges of 2.5-15.0 mug ml(-1) and 1.0-20.0 mug ml(-1) respectively, i.e. covering the legal ranges after 1 : 100 dilution. A comparison between the ethanol content in saliva, breath and blood has been carried out on 12 individuals; the determination in saliva has been shown to be a good option.

Development of a statistical model for predicting the ethanol content of blood from measurements on saliva or breath samples.

Blood, saliva and breath samples from a population of males and females subjected to the intake of preselected amounts of ethanol, whilst in different physical conditions (at rest, after physical exertion, on an empty stomach and after eating), were analysed by automatic methods employing immobilized (blood) or dissolved (saliva) enzymes and a breathanalyser. Treatment of the results obtained enabled the development of a statistical model for prediction of the ethanol concentration in blood at a given time from the ethanol concentration in saliva or breath obtained at a later time.

[Mediastinal enteric cyst: unusual clinical presentation and histopathology]. / Quiste entérico mediastínico: presentación clínica e histopatología inusuales.

A mediastinal enteric cyst is an uncommon entity which is rare in adults and usually found incidentally. In most cases the lesion is lined by gastrointestinal mucosa, and theories as to the origin of such lesions are diverse. We report an adult case of thoracic enteric cyst that presented with cardiac tamponade and for which histopathological examination revealed the presence of pancreatic tissue. Review of the literature yielded only 1 case of mediastinal enteric cyst with pancreatic tissue.

[Massive pulmonary embolism due to hydatid vesicles. Report of a case (author's transl)]. / Tromboembolismo pulmonar masivo por vesículas hidatídicas. A propósito de un caso.

A patient with hepatic and peritoneal hydatidosis suffered acute episodes of restrictive bronchial disease for the last 2 years. The patient was admitted during the course of one of this acute episodes with clinical symptoms of pulmonary embolism. Supportive therapeutic measures were prescribed, but the patient died 12 hours latter. Autopsy revealed hepatic, peritoneal and pulmonary hidatidosis as well as multiple pulmonary thromboembolisms due to hydatid vesicles. Literature on this subject is reviewed, and different clinical forms and therapeutic possibilities are discussed. The importance of small therapeutic possibilities are discussed. The importance of small recurrent hydatid embolisms in the pathogenesis of acute or subacute cor pulmonale in patients with liver hydatidosis is stressed.

[Severe neonatal encephalopathy, secondary to a prolonged vasovagal episode in a woman 31 weeks pregnant]. / Encefalopatía neonatal grave, secundaria a episodio vasovagal prolongado en una gestante de 31 semanas.

INTRODUCTION: Vasovagal syncope is not frequent during the second half of pregnancy, although the supine hypotension syndrome is common during this period. During these episodes, the marked hypotension may impede uteroplacental blood flow. CASE REPORT: A woman who was 31.5 weeks pregnant lost consciousness for 15 minutes on standing up. 24 hours later, when it was observed that foetal movement had diminished, a cardiotocographic recording was done. This showed a pathological pattern and foetal biophysical profile on echography showed a marked foetal hypotonia and absence of movement. Emergency caesarean section was carried out and a male foetus delivered, weighing 1.810 g, with an Apgar score of 5/6 and requiring intubation and mechanical ventilation for respiratory difficulties and generalized hyptonia with absent reflexes. During the following days he developed generalized hypertonia and died aged 18 days. At necropsy there was severe brain damage, of ischaemic type. Complementary tests on the mother were normal. CONCLUSIONS: Severe prenatal encephalopathy secondary to maternal vasovagal syncope is uncommon, and we have found no report of it in the literature. The prolonged duration of the hypotensive episode, together with prematurity, which implies poor regulation of cerebral blood flow, may have contributed to the severe damage to the central nervous system

[Ureteral endometriosis. Review of the literature]. / Endometriosis ureteral. Revisión de la literatura.

Ureteral endometriosis is an uncommon process. It should be suspected, however, in patients with known pelvian disease presenting urological sings and symptoms. It is important to establish early diagnosis which does not delay a conservative therapeutical approach, so as to avoid the progressive decline of renal function and, eventually, nephrectomy. Contribution of one case of extraluminar ureteral endometriosis fitting this hypothesis and review of the most appropriate etiology, sings and symptoms, diagnosis and therapeutical approach.

Physics of nanomechanical spectrometry of viruses.

There is an emerging need of nanotools able to quantify the mechanical properties of single biological entities. A promising approach is the measurement of the shifts of the resonant frequencies of ultrathin cantilevers induced by the adsorption of the studied biological systems. Here, we present a detailed theoretical analysis to calculate the resonance frequency shift induced by the mechanical stiffness of viral nanotubes. The model accounts for the high surface-to-volume ratio featured by single biological entities, the shape anisotropy and the interfacial adhesion. The model is applied to the case in which tobacco mosaic virus is randomly delivered to a silicon nitride cantilever. The theoretical framework opens the door to a novel paradigm for biological spectrometry as well as for measuring the Young's modulus of biological systems with minimal strains.

Detection of cancer biomarkers in serum using a hybrid mechanical and optoplasmonic nanosensor.

Blood contains a range of protein biomarkers that could be used in the early detection of disease. To achieve this, however, requires sensors capable of detecting (with high reproducibility) biomarkers at concentrations one million times lower than the concentration of the other blood proteins. Here, we show that a sandwich assay that combines mechanical and optoplasmonic transduction can detect cancer biomarkers in serum at ultralow concentrations. A biomarker is first recognized by a surface-anchored antibody and then by an antibody in solution that identifies a free region of the captured biomarker. This second antibody is tethered to a gold nanoparticle that acts as a mass and plasmonic label; the two signatures are detected by means of a silicon cantilever that serves as a mechanical resonator for 'weighing' the mass of the captured nanoparticles and as an optical cavity that boosts the plasmonic signal from the nanoparticles. The capabilities of the approach are illustrated with two cancer biomarkers: the carcinoembryonic antigen and the prostate specific antigen, which are currently in clinical use for the diagnosis, monitoring and prognosis of colon and prostate cancer, respectively. A detection limit of 1 × 10(-16) g ml(-1) in serum is achieved with both biomarkers, which is at least seven orders of magnitude lower than that achieved in routine clinical practice. Moreover, the rate of false positives and false negatives at this concentration is extremely low, ∼10(-4).

Immobilized enzymes in flow-injection analysis: present and trends.

An overview of the use of immobilized enzymes in flow-injection analysis (FIA) is presented. The joint use of FIA and immobilized enzymes means that analytical procedures are easily automated, analytical costs are reduced and methods are faster. The future possibilities for this combination are discussed.