Quasichiral Interactions between Quantum Emitters at the Nanoscale.

We present a combined classical and quantum electrodynamics description of the coupling between two circularly polarized quantum emitters held above a metal surface supporting surface plasmons. Depending on their position and their natural frequency, the emitter-emitter interactions evolve from being reciprocal to nonreciprocal, which makes the system a highly tunable platform for chiral coupling at the nanoscale. By relaxing the stringent material and geometrical constraints for chirality, we explore the interplay between coherent and dissipative coupling mechanisms in the system. Thus, we reveal a quasichiral regime in which its quantum optical properties are governed by its subradiant state, giving rise to extremely sharp spectral features and strong photon correlations.

Exciting Polaritons with Quantum Light.

We discuss the excitation of polaritons-strongly coupled states of light and matter-by quantum light, instead of the usual laser or thermal excitation. As one illustration of the new horizons thus opened, we introduce "Mollow spectroscopy"-a theoretical concept for a spectroscopic technique that consists of scanning the output of resonance fluorescence onto an optical target-from which weak nonlinearities can be read with high precision even in strongly dissipative environments.

Ultrafast Control and Rabi Oscillations of Polaritons.

We report the experimental observation and control of space and time-resolved light-matter Rabi oscillations in a microcavity. Our setup precision and the system coherence are so high that coherent control can be implemented with amplification or switching off of the oscillations and even erasing of the polariton density by optical pulses. The data are reproduced by a quantum optical model with excellent accuracy, providing new insights on the key components that rule the polariton dynamics.

Osteoporosis and multiple fractures in an antiretroviral-naive, HIV-positive child.

As a result of the increased incidence of osteopenia and osteoporosis in HIV-infected patients, numerous publications have suggested that there may be a link between bone metabolism alterations and HIV infection. The early bone loss seen in these patients was initially attributed to the use of highly active antiretroviral treatment (HAART) that included protease inhibitors. Recent studies, however, have suggested that it may be a direct consequence of the viral infection on bone metabolism, persistent activation of pro-inflammatory cytokines (TNFa), or altered vitamin D metabolism secondary to the virus, combined with subsequent factors (e.g., antiretroviral treatment) that aggravate the bone demineralization. We present an antiretroviral-naive 6-year-old girl with vertically transmitted HIV infection who presented with severe osteoporosis and multiple pathological fractures of the vertebrae, ribs, and upper and lower limbs. The child was treated with HAART, appropriate nutritional support for her age, physiotherapy and rehabilitation, calcium and vitamin D supplements, and alendronate therapy. After 6 weeks of treatment, the intense pain and muscle atrophy had disappeared and she was able to walk unassisted. At 6 months, bone mass had increased by 72%. The interest of this case lies in the presence of severe osteoporosis and multiple pathological fractures in an HIVinfected naive child. To date, this condition has only been described in patients treated with antiretrovirals. Moreover, this is the first reported HIV-positive pediatric patient treated with bisphosphonates, which proved to be highly successful.

Worklists, preloading and archiving strategies; 3 years of clinical experience in the Barcelona PACS.

We present data on 3 years of clinical experience using PACS involving developments on worklists, preloading and archiving strategies in a teaching paediatric hospital with all modalities connected to a commercial PACS. A method allowing generation of and handling of different worklists for computed radiography examinations has been developed in our centre. Worklists and archiving strategies are presented and discussed. We conclude that, with adequate worklists and efficient preloading implementation, current PACS could be used successfully in several clinical settings of a multimodality department.

Data interface between a radiology information system and a computed radiography system using a personal computer and standard software.

We describe the implementation of a simple data interface between a radiology information system and a computed radiography system that uses personal computers and standard software. The radiology information system was developed in house and runs in a local area network of personal computers. The computed radiography system is connected to a picture archiving and communication system. We have implemented a software data interface on a microcomputer, allowing automated transfer of patient data from the radiology information system program to the computed radiography scheduling program. The interface adds essential information used by the picture archiving and communication system to handle work lists, routing, and archiving algorithms. We have improved the user interface, shortened the scheduling time, enabled coherence of data bases, and eased the use of computed radiography and examination routing in the picture archiving and communication system. We have been using this interface for more than 1 year without difficulties. This custom solution addresses the problem of interconnecting existing equipment, avoiding proprietary restrictions or the lack of effective standards. This approach can be applied to any radiology environment that uses personal computers.

[Acute gastric volvulus in a patient with asplenic syndrome]. / Vólvulo gástrico agudo en un paciente con síndrome de asplenia.

A 18 month-old boy with asplenic syndrome was admitted to our hospital with a twelve hours history of mucous vomiting, abdominal pain and a round epigastric mass. It was diagnosed as having a gastric volvulus and an emergency laparotomy was performed. The stomach was situated at the right side and a mesenterioaxial volvulus was found, with cyanosis of the antrum. The gastrophrenic and gastrosplenic ligaments were absent. The clinical and radiological characteristics of asplenic syndrome are reviewed. The pediatric surgeons must be aware of the digestive malformations of the asplenic syndrome, because some of that like malfixation of the stomach could be the cause of an acute abdomen.

Clinical and radiographic response of Langerhans' cell histiocytosis with chemotherapy.

We present a case of osteolytic lesions for Langerhans' cell histiocytosis with complete response to cytotoxics.

Congenital pyriform sinus fistula: a cause of acute left-sided suppurative thyroiditis and neck abscess in children.

Acute bacterial thyroiditis or neck abscesses in children can be caused by infection through pyriform sinus fistulae which usually originate from the tip of the left pyriform sinus. They are thought to be remnants of either the third or fourth pharyngeal pouches. CT, ultrasound and gastrointestinal contrast studies are all useful in clarifying the pathological process and showing the extent.