Aligned copper nanorod arrays for highly efficient generation of intense ultra-broadband THz pulses.

We demonstrate an intense broadband terahertz (THz) source based on the interaction of relativistic-intensity femtosecond lasers with aligned copper nanorod array targets. For copper nanorod targets with a length of 5 µm, a maximum 13.8 times enhancement in the THz pulse energy (in ≤20 THz spectral range) is measured as compared to that with a thick plane copper target under the same laser conditions. A further increase in the nanorod length leads to a decrease in the THz pulse energy at medium frequencies (≤20 THz) and increase of the electromagnetic pulse energy in the high-frequency range (from 20-200 THz). For the latter, we measure a maximum energy enhancement of 28 times for the nanorod targets with a length of 60 µm. Particle-in-cell simulations reveal that THz pulses are mostly generated by coherent transition radiation of laser produced hot electrons, which are efficiently enhanced with the use of nanorod targets. Good agreement is found between the simulation and experimental results.

Power Doppler sonography in the evaluation and follow-up of knee involvement in patients with juvenile idiopathic arthritis.

INTRODUCTION: This study was undertaken to evaluate the role of ultrasound (US), conventional color (CD) and power Doppler (PD) in the detection and quantification of inflammatory signs of the knee in children with juvenile idiopathic arthritis (JIA) and to correlate these findings with patient history, clinical, laboratory and radiological findings. PATIENTS AND METHODS: Thirty patients with JIA who had clinical signs of knee involvement as well as 15 healthy children as a control group where subjected to full clinical examination and laboratory investigations on the same day of US examination. The knee joints were evaluated with plain radiography, US, and color Doppler in 13 patients, while the remaining 17 were assessed with power Doppler. Fourteen patients were subjected to follow-up assessment. RESULTS: A highly significant difference in synovial thickening and cartilage thickness detected by US between JIA affected knees and those of controls (p < 0.0001). Knee effusion was demonstrated in 93% of patients. Synovial vessels were detected by Doppler in 76.7% of patients. A significant correlation was detected between the degree of vascularity detected by PD and knee score (p < 0.05), and JAFAR score (P < 0.05). On comparing the findings of the follow-up with those of the initial examination, a significant positive correlation was detected between the differences in the knee score and those in synovial thickness (p < 0.05), and with the vascularity scale detected by PD (p < 0.05). CONCLUSION: This study suggests the Doppler sonography as a non-invasive, low-cost, and readily available tool for the evaluation and follow-up of articular involvement in knees of JIA patients.

A multicenter therapeutic study of 1100 children with brucellosis.

A 6-year multicenter therapeutic study was performed on 1100 children with brucellosis in order to compare several antibiotic combinations and duration of treatment. The patients were randomized to receive oral therapy with oxytetracycline, doxycycline, rifampin and trimethoprim-sulfamethoxazole (TMP/SMX) either alone or in combination with each other or combined with streptomycin or gentamicin injections. The patients were also randomized into three groups based on the duration of oral therapy: 500 patients were treated for 3 weeks; 350 for 5 weeks; and 250 for 8 weeks. When intramuscular aminoglycosides were used, streptomycin was given for 2 weeks and gentamicin for 5 days. In oral monotherapy oxytetracycline, doxycycline and rifampin showed comparable results with low relapse rates (less than or equal to 9%) and no statistically significant differences were found among 3-, 5- or 8-week durations of therapy. TMP/SMX alone showed an unacceptably high relapse rate (30%) with all durations of therapy. In combined oral therapy rifampin plus oxytetracycline, rifampin plus TMP/SMX and oxytetracycline plus TMP/SMX showed comparable results with low relapse rates ranging from 4 to 8% in patients receiving therapy for 3 or 5 weeks, no relapses occurred in patients treated for 8 weeks. When oral monotherapy was combined with either streptomycin or gentamicin, very few relapses were seen, irrespective of the duration of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)