Formation and magnetic properties of InFeP:Ag nanorods fabricated with noble metal Ag using an ion milling method.

The formation, including the density and height of the InFeP:Ag nanorods doped with noble metal Ag using an ion milling method, was preponderantly determined from transmission electron microscopy and x-ray diffraction analyses. We investigate, in particular, the enhanced ferromagnetism of the well-aligned InFeP:Ag nanorods. Auger electron spectroscopy and x-ray photoelectron spectroscopy measurements were carried out in order to investigate the incorporation of Ag and to verify the local chemical bonding of the InFeP:Ag nanorods. The variation of FWHM for the double-crystal x-ray rocking curve and triple-axis diffraction peaks demonstrates that noble metal Ag is incorporated into the InFeP:Ag nanorods. The noticeable ferromagnetic signature (M-H curve) of the InFeP:Ag nanorods is observed and T c persists up to almost 350 K (3.9 × 10-4 emu g-1), as determined by temperature-dependence magnetization (M-T curve) measurements. This study suggests that the InFeP:Ag nanorods should be a potential candidate for the application of spintronic devices.

Effects of Thermal Annealing on Optical and Microscopic Ferromagnetic Properties in InZnP:Ag Nano-Rods.

InZnP:Ag nano-rods fabricated by the ion milling method were thermally annealed in the 250~350 °C temperature range and investigated the optimum thermal annealing conditions to further understand the mutual correlation between the optical properties and the microscopic magnetic properties. The formation of InZnP:Ag nano-rods was determined from transmission electron microscopy (TEM), total reflectivity and Raman scattering analyses. The downward shifts of peak position for LO and TO modes in the Raman spectrum are indicative of the production of Ag ion-induced strain during the annealing process of the InZnP:Ag nano-rod samples. The appearance of two emission peaks of both (A0 X) and (e, Ag) in the PL spectrum indicated that acceptor states by Ag diffusion are visible due to the effective incorporation of Ag-creating acceptor states. The binding energy between the acceptor and the exciton measured as a function of temperature was found to be 21.2 meV for the sample annealed at 300 °C. The noticeable MFM image contrast and the clear change in the MFM phase with the scanning distance indicate the formation of the ferromagnetic spin coupling interaction on the surface of InZnP:Ag nano-rods by Ag diffusion. This study suggests that the InZnP:Ag nano-rods should be a potential candidate for the application of spintronic devices.

Electronic structure and magnetism in transition metals doped 8-hydroxy-quinoline aluminum.

We report the room-temperature ferromagnetism in transition metals (Co, Ni)-doped 8-hydroxy-quinoline aluminum (Alq3) by thermal coevaporation of high purity metal and Alq3 powders. For 5% Co-doped Alq3, a maximum magnetization of approximately 0.33 microB/Co at 10 K was obtained and ferromagnetic behavior was observed up to 300 K. The Co atoms interact chemically with O atoms and provide electrons to Alq3, forming new states acting as electron trap sites. From this, it is suggested that ferromagnetism may be associated with the strong chemical interaction of Co atoms and Alq3 molecules.

Partial displacement of epidural catheter after patient position change: A case report.

Epidural catheter migration is a well-known cause of failed anesthesia and complications. One of the factors that affect catheter movement is when patients change their position after skin fixation. We report a case of an epidural catheter placed without evidence of intravascular or subdural insertion that produced an insufficient block. A 36-year-old woman presented for ankle surgery under epidural anesthesia. Epidural block was conducted at the L3-4 intervertebral space with a catheter threaded 3 cm into the epidural space with the patient in a back flexion and lateral position. The total volume of injected anesthetic was 28 mL, including a 3-mL test dose. The final anesthesia level was L1. The planned operation was completed without a pneumatic tourniquet. A postoperative C-arm fluoroscopic image revealed that 1 side hole of the catheter had moved out of the epidural space. We think that a positional change after catheter fixation was the reason for catheter outmigration leading to insufficient analgesia, which was incompatible with the amount of local anesthetic injected.

Comparison of saddle, lumbar epidural and caudal blocks on anal sphincter tone: A prospective, randomized study.

Objective To compare the effects of saddle, lumbar epidural and caudal blocks on anal sphincter tone using anorectal manometry. Methods Patients undergoing elective anorectal surgery with regional anaesthesia were divided randomly into three groups and received a saddle (SD), lumbar epidural (LE), or caudal (CD) block. Anorectal manometry was performed before and 30 min after each regional block. The degree of motor blockade of the anal sphincter was compared using the maximal resting pressure (MRP) and the maximal squeezing pressure (MSP). Results The study analysis population consisted of 49 patients (SD group, n = 18; LE group, n = 16; CD group, n = 15). No significant differences were observed in the percentage inhibition of the MRP among the three regional anaesthetic groups. However, percentage inhibition of the MSP was significantly greater in the SD group (83.6 ± 13.7%) compared with the LE group (58.4 ± 19.8%) and the CD group (47.8 ± 16.9%). In all groups, MSP was reduced significantly more than MRP after each regional block. Conclusions Saddle block was more effective than lumbar epidural or caudal block for depressing anal sphincter tone. No differences were detected between lumbar epidural and caudal blocks.

Resistivity peaks and magnetic properties of an annealed graphene.

We report on the transport and magnetic properties of graphene annealed at 800 °C under an Ar atmosphere. Temperature dependence of resistivity of the annealed graphene shows that the ferromagnetic Curie temperature can be observed from the magnetoimpurity model. The Curie temperature is 220 K for the annealed graphene.

Validation of the APACHE IV model and its comparison with the APACHE II, SAPS 3, and Korean SAPS 3 models for the prediction of hospital mortality in a Korean surgical intensive care unit.

BACKGROUND: The Acute Physiology and Chronic Health Evaluation (APACHE) IV model has not yet been validated in Korea. The aim of this study was to compare the ability of the APACHE IV with those of APACHE II, Simplified Acute Physiology Score (SAPS) 3, and Korean SAPS 3 in predicting hospital mortality in a surgical intensive care unit (SICU) population. METHODS: We retrospectively reviewed electronic medical records for patients admitted to the SICU from March 2011 to February 2012 in a university hospital. Measurements of discrimination and calibration were performed using the area under the receiver operating characteristic curve (AUC) and the Hosmer-Lemeshow test, respectively. We calculated the standardized mortality ratio (SMR, actual mortality predicted mortality) for the four models. RESULTS: The study included 1,314 patients. The hospital mortality rate was 3.3%. The discriminative powers of all models were similar and very reliable. The AUCs were 0.80 for APACHE IV, 0.85 for APACHE II, 0.86 for SAPS 3, and 0.86 for Korean SAPS 3. Hosmer and Lemeshow C and H statistics showed poor calibration for all of the models (P < 0.05). The SMRs of APACHE IV, APACHE II, SAPS 3, and Korean SAPS 3 were 0.21, 0.11 0.23, 0.34, and 0.25, respectively. CONCLUSIONS: The APACHE IV revealed good discrimination but poor calibration. The overall discrimination and calibration of APACHE IV were similar to those of APACHE II, SAPS 3, and Korean SAPS 3 in this study. A high level of customization is required to improve calibration in this study setting.