Stability and morphology of Ag nanoplatelets probed by depolarized dynamic light scattering.

The stability of silver nanoplatelet (NP) suspensions prepared with different concentrations of trisodium citrate (TSC) was studied by depolarized dynamic light scattering (DDLS) and UV-vis spectrometry. The morphology of the nanoparticles, as well as the color and stability of the sols, are tuned by the concentration of the capping agent. The nanoparticles prepared with high TSC concentration (>10-4 M) are blue triangular NPs showing a slight truncation of the tips with aging. When low TSC concentrations are used, the color of the sols changes from blue to yellow with aging time and a strong modification of the morphology occurs: the nanoparticle shape changes from triangular to spherical. Remarkably, they show a high degree of anisotropy. The aging process was followed by the UV-vis spectra and by measuring the rotational diffusion coefficient by DDLS, providing information on the nanoparticle size and shape evolution. The high intensity of depolarized signal and the high value of rotational diffusion coefficient suggest that the aging process increases the thickness and the roughness of the nanoparticles.

Optical trapping of silver nanoplatelets.

Optical trapping of silver nanoplatelets obtained with a simple room temperature chemical synthesis technique is reported. Trap spring constants are measured for platelets with different diameters to investigate the size-scaling behaviour. Experimental data are compared with models of optical forces based on the dipole approximation and on electromagnetic scattering within a T-matrix framework. Finally, we discuss applications of these nanoplatelets for surface-enhanced Raman spectroscopy.

Determinando el pronóstico del paciente gran quemado: correlación del Índice de Garcés con el Abbreviated Burn Severity Index (ABSI) / Defining the prognosis of the burned patient: correlation of the Garces Index with the Abbreviated Burn Severity Index (ABSI)

Resumen Introducción: Existen distintos scores pronósticos para determinar probabilidad de muerte en pacientes quemados. El Índice de Garcés (IG) utilizado en Chile, no es aceptado mundialmente. Objetivo: Decidimos evaluar la correlación entre IG y Abbreviated Burn Severity Index (ABSI), de uso generalizado. Materiales y Método Estudio descriptivo analítico transversal de pacientes quemados subidos a la plataforma online "Registro Nacional de Quemados" y luego ingresados a nuestro centro entre julio de 2017 y julio de 2018. Se calculó coeficiente de correlación de Pearson entre IG y ABSI. Se normalizan ambas variables para hacerlas comparables y se calculó concordancia entre estas con coeficiente de correlación de Lin. Con análisis de regresión logística se calculó probabilidad de fallecer asociada para ambas variables y se compararon áreas de las curvas ROC de ambos scores. Resultados: De 141 pacientes, 15 fallecieron durante hospitalización, con medias de IG de 104 ± 49 puntos y ABSI 7 ± 2. El coeficiente de correlación de Pearson entre IG y ABSI demostró ser muy alto con un valor de 0,928. El coeficiente de correlación de Lin entregó concordancia moderada con un valor de 0,93. Al comprobar cuál de las dos puntuaciones predice mejor la probabilidad de muerte mediante análisis de sensibilidad y especificidad, la curva ROC cubre más área en IG (0,82 vs. 0,83), sin ser estadísticamente significativo. Conclusiones: Ambos índices, IG y ABSI, son muy similares para predecir la probabilidad de muerte, por lo cual son equiparables a la hora de compartir resultados de estudios científicos.

Introduction: There are different prognostic scores to determine the probability of death in burned patients. The Garces Index (GI) used in Chile is not accepted worldwide. Aim: We decided to evaluate the correlation between IG and Abbreviated Burn Severity Index (ABSI), which is widely used. Materials and Method: Cross-sectional analytical and descriptive study of burned patients uploaded to the online platform "National Burns Registry" and then admitted to our center between July 2017 and July 2018. Pearson's correlation coefficient between IG and ABSI was calculated. Both variables were normalized to be able to make them comparable and the agreement between them was calculated with Lin's correlation coefficient. With logistic regression analysis, the associated probability of death was calculated for both variables and areas of the ROC curves of both scores were compared. Results: Of 141 patients, 15 died during hospitalization, with a mean GI 104 ± 49 and ABSI 7 ± 2. Pearson's correlation coefficient between GI and ABSI showed a very high correlation with a value of 0.928. Lin's correlation coefficient gave moderate agreement with a value of 0.93. When checking which of the two scores best predicts the probability of death through sensitivity and specificity analysis, the ROC curve covers more area in IG (0.82 vs 0.83) without being statistically significant. Conclusions: Both scores, IG and ABSI, are very similar when it comes to predicting the probability of death, which is why they are comparable at the time of sharing the results in scientific studies.

Registro Nacional de Quemados Chile: presentación de una plataforma online y mirada al pronóstico de pacientes no trasladados a Centro de Quemados / Presentation of an online National Registration Platform for severely burned patients in the Chilean Public Health System and a look into the prognosis of patients not transferred to the National Reference Burn Center

Resumen Introducción: En el año 2017 se incorporó un registro de notificación en línea (Registro Nacional de Quemados) al flujo de derivación de pacientes quemados en Chile. Objetivo: A partir de la información obtenida de esta plataforma, se describe la epidemiología de las quemaduras y las variables que podrían explicar los traslados fallidos a nuestra unidad de quemados. Materiales y Método: Se analizaron los casos subidos a esta plataforma entre julio de 2017 y julio de 2018. Se caracterizó la población global y comparó variables relevantes entre el grupo de pacientes no trasladados a nuestra unidad y los que fueron trasladados con éxito. Resultados: Se analizaron 319 pacientes, 66% hombres, edad promedio 51 años, IMC de 27% y 47% con enfermedades previas. El fuego fue la principal causa de quemaduras. Se observó un 31% de injuria inhaladora. 107 pacientes no se trasladaron a nuestro centro de quemados. Los pacientes trasladados puntuaron más alto en comorbilidad, índice de gravedad, superficie corporal total quemada y aseo quirúrgico en el hospital base. El grupo de pacientes no trasladados puntuó más alto en injuria inhalatoria. La mortalidad global fue 20,4%. La mortalidad fue mayor en pacientes no trasladados (33,6% versus 13,7%; p < 0,001). Conclusiones: Además de facilitar el flujo de pacientes y ahorrar recursos, un uso noble de esta plataforma es ser fuente de información epidemiológica y de implementación de políticas públicas, lo cual puede ser tomado como ejemplo por otros países en vías de desarrollo. Además, se demuestra que ser trasladado constituye un factor protector de muerte por quemaduras.

Introduction: In 2017, an online notification register, the National Burn Registry, was incorporated into the referral flow of burned patients in Chile. Aim: Through the information obtained from this platform, we describe the epidemiology of burns in Chile, and identify variables that could explain failed transfers to our burn unit. Materials and Method: Cases uploaded to this platform between July 2017 - July 2018 were analyzed. We characterize the global population and relevant variables were compared between the group of patients that failed to be transferred to the burn unit and the ones who were successfully transferred. Results: 319 patients were analyzed, 66% men, average age 51 years, BMI of 27 and 47% with previous illnesses. Fire was the main cause of burn injury. Smoke inhalation injury was observed for 31%. 107 patients failed to reach to our burn center. Transferred patients rated higher in comorbidity, severity index, total burned body surface and surgical debridement at base hospital. The group of not transferred patients rated higher in inhalation injury. Overall mortality was 20.4%. Mortality was higher in non-transferred patients (33.6% versus 13.7%; p < 0.001). Conclusions: Aside from facilitating the flow of burned patients and resources saving, a noble use of this platform has been to serve as a source of epidemiological information and implementation of public policies, which can be taken as an example by other developing countries. Also, being transferred is a protective factor for death from burn injuries.

HIV and HTLV infections in 1305 transfusion-dependent thalassemics in Italy. The COOLEYCARE Cooperative Group.

OBJECTIVE: To evaluate the prevalence of antibodies to HIV-1/2 and HTLV-I/II in 1305 transfusion-dependent beta-thalassemics treated in 36 centres in Italy. DESIGN: Patient serum samples were collected during 1990 and tested in Milan. METHODS: Sera were screened using an enzyme-linked immunosorbent assay (ELISA) containing viral lysate antigens from HIV-1 and HIV-2, and a particle agglutination assay for the detection of antibodies to HTLV-I and HTLV-II. Repeatedly reactive samples were examined by Western blot (WB) assays containing recombinant and viral lysate antigens. Differential diagnosis was finally made by ELISA based on synthetic peptides. RESULTS: Samples from 36 of the 1305 patients (2.76%) contained anti-HIV-1 antibodies. In four patients seroconversion occurred after the implementation of anti-HIV-1 screening in blood donors in Italy (1985). Of the 36 HIV-1-antibody-positive samples, four were HIV-2 [corrected] WB indeterminate. These four samples were negative in assays based on specific synthetic peptides, suggesting cross-reactivity. Anti-HTLV-I antibodies were found in two patients from Sicily and one from Apulia, both southern Italian regions. Anti-HTLV-II antibodies were detected in another patient from Sicily. CONCLUSIONS: Antibodies to HIV-1, HIV-2, HTLV-I and HTLV-II were detected in 2.76, 0, 0.23 and 0.08% of patients, respectively. The residual risk of HIV-1 infection through blood transfusion after the implementation of anti-HIV-1 screening in blood donors in Italy was approximately 1:50,000 blood units; this is based on an approximate number of 200,000 blood units administered to our group of patients during 1986-1990 and the occurrence of four new anti-HIV-1 seroconversions. Seroconversions to HTLV-I/II suggest that these viruses are present in Italian blood donors.

Primary malignant melanoma of male urethra.

A case of primary malignant melanoma of the male urethra is reported. Treatment included partial urethrectomy, bilateral inguinal and iliac lymphadenectomy, and post-surgical systemic chemotherapy. After thirty-six months, the patient is alive with cutaneous, pelvic lymph node, and gastric metastases.

Load transmission evaluation by removable distal-extension partial dentures using holographic interferometry.

Five pairs of bilateral distal-extension removable partial dentures with different clasp designs were constructed on the same dried human mandible in order to compare their load distribution characteristics. The technique of holographic interferometry was used. Among the dentures tested, those with RPI and back action clasps having mesial rests provided the best results from the mechanical point of view. The most unfavourable behaviour was presented by the Akers clasps design. The RPA design and dentures having clasps with continuous MOD rest gave intermediate results.

[Correlations between asthmatic crisis and meteorological conditions in Rosario, Argentina]. / Correlaciones entre las crisis de asma y las condiciones meteorológicas en Rosario, Argentina.

The aim of this work was to find out whether there is any relationship between the climate in Rosario City, Argentina, and the frequency of asthmatic crises, and whether it would be possible to use weather forecasts to support therapeutic measures. Synoptic and statistical metereological analyses, were used, and the following results achieved: The 721 crises of asthma developed in Rosario City between August 1, 1978 and July 31, 1979, demonstrated the well-known seasonal distribution of similar biological events: high frequencies in the Spring and Fall and low ones in the Summer and Winter. Important correlations were found with high altitude depression systems Hence, in the great majority of cases, the daily frequency of crises attained its maximum values when a depression system in the 500 mb. level was approximately between 60 degrees and 72 degrees W of G. and returned to minimum values when the mentioned system, in its general displacement towards the east, passed the meridian of Rosario City, whose geographic coordinates are: Lat. 32 degrees 55' S, Long. 60 degrees 47' W of G., at 27 meters above sea level. In short, we can say that, as occurs in other parts of the world, the asthmatic crises undergone by children in Rosario City are produced with much more frequency in circumstances of cyclonic atmospheric circulation. Although these situations, in the case of Rosario City, are determined by the dynamic processes in the higher levels of the troposphere. This is probably due to the role played by the Andres Mountain Range in the processes of atmospheric circulation in subtropical South America.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacampicillin and the immune response.

To evaluate the possible influence of a bacampicillin on the immune response, 16 subjects, out of a group of 60 patients with bacterial respiratory tract infections, had various tests of immune function determined, before and after treatment. The peripheral mononuclear blastogenic index (ratio between PHA-induced and spontaneous proliferation), PHA-induced interferon-gamma production, percentages of T and B lymphocytes, serum immunoglobulins (IgG, IgM, IgA) levels, failed to show any significative differences before and after the treatment with bacampicillin. The PHA-induced interleukin-2 production increased after treatment but just failed to reach statistical significance (0.1 less than P less than 0.05; t = 1.9). The clinical condition of 56 of the sixty (93.3%) treated patients improved and neither side-effects nor alterations of liver or kidney function were observed. This study has shown no inhibitory effect of bacampicillin on the immune response while confirming its clinical efficacy.