Synthesis of Ag@Silica Nanoparticles by Assisted Laser Ablation.

This paper reports the synthesis of silver nanoparticles coated with porous silica (Ag@Silica NPs) using an assisted laser ablation method. This method is a chemical synthesis where one of the reagents (the reducer agent) is introduced in nanometer form by laser ablation of a solid target submerged in an aqueous solution. In a first step, a silicon wafer immersed in water solution was laser ablated for several minutes. Subsequently, an AgNO3 aliquot was added to the aqueous solution. The redox reaction between the silver ions and ablation products leads to a colloidal suspension of core-shell Ag@Silica NPs. The influence of the laser pulse energy, laser wavelength, ablation time, and Ag(+) concentration on the size and optical properties of the Ag@Silica NPs was investigated. Furthermore, the colloidal suspensions were studied by UV-VIS-NIR spectroscopy, X-Ray diffraction, and high-resolution transmission electron microscopy (HRTEM).

Guidelines for the management of community-acquired pneumonia in the elderly patient.

The incidence of community-acquired pneumonia (CAP) increases with age and is associated with an elevated morbimortality due to the physiological changes associated with aging and a greater presence of chronic disease. Taking into account the importance of this disease from an epidemiological and prognostic point of view, and the enormous heterogeneity described in the clinical management of the elderly, we believe a specific consensus document regarding this patient profile is necessary. The purpose of the present work was to perform a review of the evidence related to the risk factors for the etiology, the clinical presentation, the management and the treatment of CAP in elderly patients with the aim of elaborating a series of specific recommendations based on critical analysis of the literature. This document is the fruit of the collaboration of different specialists representing the Spanish Society of Emergency Medicine and Emergency Care (SEMES), the Spanish Society of Geriatrics and Gerontology (SEGG), the Spanish Society of Chemotherapy (SEQ), the Spanish Society of Internal Medicine (SEMI), the Spanish Society of Pneumology and Thoracic Surgery (SEPAR) and the Spanish Society of Home Hospitalization (SEHAD).

¿Cuándo, dónde y cómo ingresar al paciente con neumonía adquirida en la comunidad? / When, where and how should a patient with community acquired pneumonia be admitted?

La neumonía adquirida en la comunidad constituye la principal causa de muerte (10-14%) por enfermedad infecciosa y origina gran parte de las sepsis y shock sépticos atendidos en los servicios de urgencias. Existe gran variabilidad en sus tasas de ingreso (22-61%), y de estos, el 10-20% lo hace en una unidad de cuidados intensivos. Determinar correctamente la necesidad de ingreso (el cuándo), la ubicación (el dónde) y la intensidad de cuidados requeridos (el cómo) va a condicionar el pronóstico del paciente, la solicitud de pruebas básicas y estudios microbiológicos, la pauta antibiótica (vía y duración), la intensidad de observación clínica y, a la postre, la utilización de recursos sociosanitarios (costes). Este trabajo pretende orientar en la toma de estas decisiones teniendo en cuenta las nuevas tendencias en valoración pronóstica y las alternativas a la hospitalización convencional(AU)

Community-acquired pneumonia is the leading cause of death (10%-14%) from infectious disease and the source of many sepsis and septic shock cases attended in the emergency departments. There is great variability in the admission rates (22%-61%), and 10%-20% of such admissions have to be done in the intensive care unit. The correct determination of need for admission (when), admission site (where) and burden of delivered care (how) will determine the patient's prognosis, request for basic and microbiological studies, antibiotic regimen (via and duration), clinical follow-up intensity and, consequently, the use of socio-health resources (costs). This article aims to orient decision-making, taking into account the new trends in prognostic evaluation tendencies and the current alternatives to the classic hospital admission(AU)

When, where and how should a patient with community acquired pneumonia be admitted?

Community-acquired pneumonia is the leading cause of death (10-14%) from infectious disease and the source of many sepsis and septic shock cases attended in the emergency departments. There is great variability in the admission rates (22-61%), and 10-20% of such admissions have to be done in the intensive care unit. The correct determination of need for admission (when), admission site (where) and burden of delivered care (how) will determine the patient's prognosis, request for basic and microbiological studies, antibiotic regimen (via and duration), clinical follow-up intensity and, consequently, the use of socio-health resources (costs). This article aims to orient decision-making, taking into account the new trends in prognostic evaluation tendencies and the current alternatives to the classic hospital admission.

Assessment of temporal state-dependent interactions between auditory fMRI responses to desired and undesired acoustic sources.

A confounding factor in auditory functional magnetic resonance imaging (fMRI) experiments is the presence of the acoustic noise inherently associated with the echo planar imaging acquisition technique. Previous studies have demonstrated that this noise can induce unwanted neuronal responses that can mask stimulus-induced responses. Similarly, activation accumulated over multiple stimuli has been demonstrated to elevate the baseline, thus reducing the dynamic range available for subsequent responses. To best evaluate responses to auditory stimuli, it is necessary to account for the presence of all recent acoustic stimulation, beginning with an understanding of the attenuating effects brought about by interaction between and among induced unwanted neuronal responses, and responses to desired auditory stimuli. This study focuses on the characterization of the duration of this temporal memory and qualitative assessment of the associated response attenuation. Two experimental parameters--inter-stimulus interval (ISI) and repetition time (TR)--were varied during an fMRI experiment in which participants were asked to passively attend to an auditory stimulus. Results present evidence of a state-dependent interaction between induced responses. As expected, attenuating effects of these interactions become less significant as TR and ISI increase and in contrast to previous work, persist up to 18s after a stimulus presentation.

Physiological noise effects on the flip angle selection in BOLD fMRI.

This work addresses the choice of imaging flip angle in blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI). When noise of physiological origin becomes the dominant noise source in fMRI timeseries, it causes a nonlinear dependence of the temporal signal-to-noise ratio (TSNR) versus signal-to-noise ratio (SNR) that can be exploited to perform BOLD fMRI at angles well below the Ernst angle without any detrimental effect on our ability to detect sites of neuronal activation. We show, both experimentally and theoretically, that for situations where available SNR is high and physiological noise dominates over system/thermal noise, although TSNR still reaches it maximum for the Ernst angle, reduction of imaging flip angle well below this angle results in negligible loss in TSNR. Moreover, we provide a way to compute a suggested imaging flip angle, which constitutes a conservative estimate of the minimum flip angle that can be used under given experimental SNR and physiological noise levels. For our experimental conditions, this suggested angle equals 7.63° for the grey matter compartment, while the Ernst angle=77°. Finally, using data from eight subjects with a combined visual-motor task we show that imaging at angles as low as 9° introduces no significant differences in observed hemodynamic response time-course, contrast-to-noise ratio, voxel-wise effect size or statistical maps of activation as compared to imaging at 75° (an angle close to the Ernst angle). These results suggest that using low flip angles in BOLD fMRI experimentation to obtain benefits such as (1) reduction of RF power, (2) limitation of apparent T(1)-related inflow effects, (3) reduction of through-plane motion artifacts, (4) lower levels of physiological noise, and (5) improved tissue contrast is feasible when physiological noise dominates and SNR is high.

Superior mesenteric venous thrombosis: a retrospective study of thirteen cases.

OBJECTIVE: To analyze the epidemiology, associated risk factors, clinical presentation, diagnostic methods, treatment, and evolution of patients diagnosed with superior mesenteric venous thrombosis (SMVT) at an university hospital in Madrid. EXPERIMENTAL DESIGN: Retrospective and descriptive study. We review the medical records of patients with this diagnosis in our hospital from January 1998 to December 2002. Data were processed by using the SPSS vs. 11 software. PATIENTS: All thirteen subjects diagnosed with SMVT in that period were included. RESULTS: Associated risk factors included tumoral conditions (5 patients), acute abdominal pathology (2), polyglobulia (1), prothrombin gene mutation (1), and anticardiolipin antibodies (1). No predisposing factor was found in 3 patients. Clinical presentation for all patients was abdominal pain, with nausea and vomiting being the second symptom in frequency (7). The diagnosis was reached by abdominal CT (9), arteriography (2), ultrasounds (1), and histology after intestinal resection (1). Treatment with only anticoagulation was initiated in 4 patients, whereas anticoagulation and surgery were performed in 5 cases. In 4 subjects no specific treatment was prescribed and only palliative measures were established due to a baseline end-stage condition. Five patients died, and four of them had a neoplasic condition as associated risk factor. Mortality in our series was 38.5%. CONCLUSIONS: SMVT is a very rare disease that is often associated with neoplasic pathology, which influences its high mortality. Due to non specific symptoms, imaging is essential for the diagnosis and the detection of associated risk factors. In our series, computed tomography imaging was the most profitable test.

Fractura patológica de sacro en un paciente VIH en terapia antirretroviral de alta eficacia / Pathological fracture of sacrum in a HIV-patient on HAART

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Mesenteric tuberculosis with jejunal infiltration.

A 69-year-old female was admitted to our hospital because of asthenia, anorexia and 20 kg weight loss. An ultrasound study and computerized tomography (CT) imaging revealed a mesenteric mass and laparotomy was performed. The diagnosis was mesenteric tuberculosis with jejunal involvement. This represents an atypical onset of tuberculosis in a non-immunosuppressed patient.

[Opportunistic episodes in patients infected with the human immunodeficiency virus during the first 6 months of HAART]. / Episodios oportunistas en pacientes infectados por el virus de la inmunodeficiencia humana durante los primeros 6 meses de la terapia antirretroviral de gran actividad.

BACKGROUND: We aimed at analysing the incidence and characteristics of opportunistic events (OE) within a few months after starting highly active antiretroviral therapy (HAART) in HIV infected patients. PATIENTS AND METHOD: Retrospective study of HIV infected outclinic patients attended in a HIV/AIDS reference hospital in Madrid, who initiated HAART during the second semester of 1998, with a baseline CD4 cell count 250 x 10(6) cells/l. We recorded the incidence of OE within 6 months after beginning HAART and analysed virological and immunological parameters, sociodemographic variables and types of antiretroviral treatment. RESULTS: The study included 269 patients. Twenty-one (7.8%) OE were recorded. At the onset of HAART, the mean CD4 cell count in these 21 patients was 137 (92) x 10(6)/land the median viral load was 24,043 cop/ml. At the time of OE diagnosis, these parameters were 218 (114) x 10(6)/l (p = 0.012) and < 500 cop/ml, respectively. OE were distributed as follows: herpes zoster, 9 cases (43%), Pneumocystis carinii pneumonia, 5 cases (24%), Kaposi sarcoma,3 cases (14%) and tuberculosis, cerebral toxoplasmosis, cytomegalovirus retinitis, and non-Hodgkin lymphoma, 1 case each. Overall, 78% of OE occurred within first 4 months after beginning HAART. In addition, an OE was developed by 8% patients treated with NRTI and PI, 2% treated with NRTI and NNRTI, and 10% treated with NRTI,NNRTI and PI (p = 0.44). CONCLUSIONS: HIV-infected subjects with low CD4 counts are prone to develop OE within the first few moths after beginning HAART. An inflammatory response to latent antigens due to the immune recovery might explain this fact.

[Histiocytosis management (author's transl)]. / Tratamiento de la histiocitósis.

Seven cases of Histiocytosis have been treated with VB and PR. Five of them that belong to grup C (according to Oberman's classification) experimented favorable resuts. Likewise, we have been able to prove that prognosis of these children depend on: their age at the onset of the disease; the original site of the disease; the extension of the lesions and the maintenance of prolonged therapy.