Bi-doping improves the magnetic properties of zinc oxide nanowires

Room-temperature ferromagnetism in the large and direct bandgap diluted magnetic semiconductor zinc oxide (ZnO) is attributed to the intrinsic defects and p-orbital–p-orbital (p–p) coupling interaction. However, due to oxidation, the ferromagnetism induced by defects is unstable. In the present work, the solution process synthesis route was utilized to grow pristine and bismuth-doped, highly crystalline ZnO nanowire (ZnO NW)-based samples. The FE-SEM images showed that the grown ZnO NWs have a preferred orientation along the c-axis in the (001) direction due to the anisotropic crystal nature of ZnO. X-ray photoelectron spectroscopy (XPS) confirmed the presence of Bi, and at a higher doping content, the bismuth oxide phase appeared. The XRD patterns showed the wurtzite crystal structure, and the large intensity of the (002) peak suggests that most of the reflection was from the top hexagonal face of the NWs, and thus, the wires are predominantly aligned along the c-axis. The TEM analysis further confirmed the crystal growth direction along the (001) direction. The UV-Visible absorption and PL measurements also showed a decrease in the bandgap with an increase in doping concentration, which may be associated with the sp–d exchange interaction between the localized d-electrons and band electrons of the Bi ions. Bi-doping tended to increase the PL intensity in the visible region. The magnetic properties measured by SQUID at 4 and 300 K showed ferromagnetic behaviour for both the pristine and Bi-doped samples. However, the saturation magnetization for the Bi-doped samples was higher compared to that of the pristine ZnO samples until the threshold doping value. The obtained results demonstrated that Bi-doping can be used to tune both the optical and magnetic properties of ZnO NWs, hence paving the way for future spintronics and spin-polarized optoelectronics applications.

Room-temperature ferromagnetism in the large and direct bandgap diluted magnetic semiconductor zinc oxide (ZnO) is attributed to the intrinsic defects and p-orbital–p-orbital (p–p) coupling interaction.     

Adjuvant Hepatic Intra-arterial Iodine-131-Lipiodol Following Curative Resection of Hepatocellular Carcinoma: A Prospective Randomized Trial

Background

The purpose of the present study was to determine whether intrahepatic injection of ¹³¹I-lipiodol (Lipiodol) is effective against recurrence of surgically resected hepatocellular carcinoma (HCC).

Methods

From June 2001 through March 2007, this nationwide multi-center prospective randomized controlled trial enrolled 103 patients 4–6 weeks after curative resection of HCC with complete recovery (52: Lipiodol, 51: Control). Follow-up was every 3 months for 1 year, then every 6 months. Primary and secondary endpoints were recurrence-free survival (RFS) and overall survival (OS), respectively, both of which were evaluated by the Kaplan–Meier technique and summarized by the hazard ratio (HR). The design was based on information obtained from a similar trial that had been conducted in Hong Kong.

Results

The Lipiodol group showed a small, and nonsignificant, improvement over control in RFS (HR = 0.75; 95 % confidence interval [95 % CI] 0.46–1.23; p = 0.25) and OS (HR = 0.88; 95 % CI 0.51–1.51; p = 0.64). Only two serious adverse events were reported, both with hypothyroidism caused by ¹³¹I-lipiodol and hepatic artery dissection during angiography.

Conclusions

The randomized trial provides insufficient evidence to recommend the routine use of ¹³¹I-lipiodol in these patients.     

Ocular surface temperature: a 3D FEM prediction using bioheat equation

Computational and mathematical human eye models from previous studies which were constructed in two-dimensions (2D) did not give a precise representation of the actual human eye. This work is an extension from an earlier published work on the 2D model. In this paper, a 3D FEM model of the human eye is simulated for the steady state temperature distribution during normal condition and during electromagnetic (EM) wave radiation. Results show a discrepancy of 0.49% for a normal condition as opposed to 1.9% of a 2D model when compared to experimental results from open literatures. Investigations on the EM wave radiations found an average power absorption density of 15,151 and 22,145 Wm(-3) for the 750 and 1500 MHz radiation, respectively. A peak temperature of 38.18( composite function)C was predicted for the 750 MHz radiation while 41.19( composite function)C was computed for the 1500 MHz radiation. These temperatures are in reasonable agreement with the simulated results computed by another report in the past.     

Procedure of endoscopic removal of a gutta-percha point under the maxillary sinus mucosa by using an ultrathin arthroscope

We describe here a procedure of endoscopic removal of a gutta-percha point under the maxillary sinus mucosa by using an ultrathin arthroscope. In this study, a 1.2-mm-diameter ultrathin arthroscope was introduced for observation into the maxillary sinus. The surgical technique is suggested to be a reliable and minimally invasive procedure that provides limited incision and bone removal and respects the integrity of the sinus.     

Validation of the Hong Kong Chinese version of the St. George Respiratory Questionnaire in patients with bronchiectasis

STUDY OBJECTIVES: To validate the Hong Kong Chinese version of the St. George Respiratory Questionnaire (SGRQ-HK) in patients with bronchiectasis. DESIGN AND SETTING: Outpatients (93 patients; 61 women; mean age [+/- SD], 59.0 +/- 14.2 years) were assessed at baseline by the SGRQ-HK, the Hong Kong Chinese version of the 36-item short form health survey (SF-36-HK), and the hospital anxiety and depression scale (HADS). Forty randomly selected patients also were reassessed at 2 weeks for repeatability. Seventy-two patients were further reassessed at 6 months for responsiveness. Measurements and results: Cronbach alpha coefficients, which reflected internal consistency, were > 0.7 for all SGRQ-HK components except for symptoms (alpha = 0.59), and the intraclass correlation coefficients between baseline and the 2-week follow-up visits were between 0.80 and 0.94 (p > 0.05). SGRQ-HK component scores and total scores correlated with all the component scores of the SF-36-HK and the HADS (p < 0.02). SGRQ-HK component scores and total scores correlated with the scores of the SF-36-HK and the HADS, confirming the concurrent validity. All SGRQ-HK scores correlated negatively with FEV(1), FVC, and arterial oxygen saturation (p < 0.005), while the activity score correlated with the Karnofsky performance scale and the number of bronchiectatic lobes (p < 0.001). SGRQ-HK scores positively correlated with Borg scale scores, exacerbation frequency, and 24-h sputum volumes (p < 0.03). Patients with 24-h sputum volumes of > or = 10 mL or < 10 mL had significantly different SQRG-HK component scores and total scores (p < 0.002), although this sensitivity was not displayed by scores on the HADS or the SF-36-HK. Patients with 25% reductions in 24-h sputum volumes had significant improvements in SGRQ-HK activity scores, impact scores, and total scores (p < 0.02), but not in other quality-of-life measures or clinical parameters, indicating the responsiveness of the SGRQ-HK. CONCLUSION: The SGRQ-HK is a valid and sensitive instrument for determining quality of life in bronchiectasis patients.