Infrared optical absorption spectra of CuO single crystals: Fermion-spinon band and dimensional crossover of the antiferromagnetic order

We have obtained mid-infrared optical absorption spectra of the S=1/2 quasi one-dimensional CuO using polarized transmission measurement and interpreted the spectra in terms of phonon assisted magnetic excitations. When the electric field is parallel to the main antiferromagnetic direction a Delta shaped peak is observed with the maximum at 0.23eV which is attributed to spinons along Cu-O chains. At low temperatures in the antiferromagnetic phase another peak appears at 0.16eV which is attributed to two-magnon absorption but the spinon peak remains. This behavior is interpreted as due to a dimensional crossover where the low temperature three-dimensional magnetic phase keeps short range characteristics of a one-dimensional magnet.Comment: 5 pages, 5 figure

Highway Construction Productivity Measurement with a Wireless Real-Time Productivity Measurement System

Seonghoon Kim, Yong Bai, Yang-Ki Jung, and Dukgeun Yun, Highway Construction Productivity Measurement with a Wireless Real-Time Productivity Measurement System, Transportation Research Record: Journal of the Transportation Research Board (Volume: 2228 issue: 1) pp. 26-33. Copyright © 2011 SAGE Publications. DOI: 10.3141/2228-04.Improving the quality of construction schedules calls for development of an advanced productivity measurement system. Existing on-site construction productivity measurement methods have some common limitations, such as not providing data necessary for engineers and project managers to conduct real-time analyses and share data with other project participants. A wireless real-time productivity measurement (WRITE) system was developed to address those shortfalls. The field experiment was conducted at two different stages: asphalt paving projects, including hot-mix asphalt and hot-in-place recycling, and a bridge reconstruction project. Productivity data collected from the WRITE system were also compared with productivity data collected from construction documents, such as contractors' daily logs and pay estimate documents, to identify the feasibility of this system for measuring the performance of construction projects. For data analyses, statistical methods such as normality test, paired t-test, and Wilcoxon signed-rank test were used. The result of statistical analyses proved that the developed system generated identical productivity measurements compared with the stopwatch method and construction documents. The success of this research project made several major contributions to the advancement of the construction industry. First, the research advanced the application of wireless technology in highway construction operations. Second, it provided an advanced technology for engineers and project managers to determine productivity in real time. Third, productivity data can be shared between project participants via the Internet. With these advancements, communication and coordination will be improved at construction sites. Consequently, the WRITE system will enhance owners' and contractors' ability to manage construction projects

Factors associated with stroke in patients with paroxysmal atrial fibrillation beyond CHADS2 score

Background: This study was conducted to investigate factors associated with stroke in pa­tients with paroxysmal atrial fibrillation (PAF) beyond CHADS2 score in terms of left ventricular (LV) diastolic function or left atrial (LA) function. Methods: One hundred and sixty-one patients with PAF and age less than 75 (mean age 61 ± 10; 69 male) who underwent transthoracic echocardiography were investigated. Patients were divided into two groups according to the stroke status (group 1 — no stroke vs. group 2 — presence of stroke). Baseline echocardiographic parameters and LA segmental (4 segments: basal septal, lateral, inferior, and anterior) strain rate (SR) during normal sinus rhythm were analyzed. Results: CHAD score (except S2) was similar between the two groups (0.6 ± 0.7 vs. 0.9 ± 0.7, p = 0.125). Patients with stroke had slightly lower body mass index (24.5 ± 2.7 vs. 23.4 ± ± 2.4, p = 0.052). Echocardiographic parameters did not show any differences in both systolic and diastolic functions between the two groups, however elevated E/E’ ratio was noted (9.5 ± ± 3.8 vs. 11.6 ± 3.9, p = 0.010) due to higher E velocity (63.5 ± 15.9 vs. 70.9 ± 16.0 cm/s, p = 0.046). In the analysis of LA SR, there are no differences of SR among the 4 segments. However, standard deviations (SD) of time to peak SR (SD of tA-SR) of the 4 segments were higher in patients with stroke (10.9 ± 9.9 vs. 22.1 ± 18.1 ms, p = 0.009) which indicates dyssynchronous contraction of LA. In multivariate analysis, SD of tA-SR (OR 1.074, CI 1.024–1.128, p = 0.004) and elevated E/E’ (OR 1.189, CI 1.006–1.406, p = 0.048) were independently associated with stroke in patients with PAF. Conclusions: Elevated E velocity, E/E’ and SD of tA-SR were associated with occurrence of stroke in patients with PAF even with similar CHAD scores. Increased SD of tA-SR and E/E’ were independently associated with stroke in patients with PAF.

Reversible Symptomatic Myocarditis Induced by All-Trans Retinoic Acid Administration during Induction Treatment of Acute Promyelocytic Leukemia: Rare Cardiac Manifestation as a Retinoic Acid Syndrome

Treatment by All-trans retinoic acid (ATRA) followed by anthracycline-AraC chemotherapy has improved the outcome of acute promyelocytic leukemia. ATRA is usually well tolerated, but a few major side effects can be observed. Retinoic acid syndrome (RAS) often occurs during the induction chemotherapy of acute promyelocytic leukemia. A pericardial effusion is a common cardiac manifestation but myocarditis has been rarely documented. Here we reports a very rare case of fully recovered myocarditis as a result of RAS related to ATRA administration during induction treatment of acute promyelocytic leukemia which documented by echocardiographic evidence

Tracheal rupture after endotracheal intubation - A report of three cases -

Tracheal rupture is a rare but serious complication that occurs after endotracheal intubation. It usually presents as a linear lesion in the membranous wall of the trachea, and is more prevalent in women and patients older than 50 years. The clinical manifestations of tracheal injury include subcutaneous emphysema and respiratory distress. We report the cases of three female patients of old age presenting tracheal rupture after endotracheal intubation. Two cases received surgical repair without complication and one recovered uneventfully after conservative management. We presume that the tracheal injuries were caused by over-inflation of cuff and sudden movement of the tube by positional change. Therefore, we recommend cuff pressure monitoring during general anesthesia and minimized movement of the head and neck at positional change

Predictors for Dexmedetomidine Requirement for Sedation under Regional Anesthesia

(1) Background: This prospective observational study aimed to investigate the predictors affecting DMT requirements for sedation during regional anesthesia. (2) Method: A total of 108 patients who received regional anesthesia with intravenous DMT administration for orthopedic upper- or lower-extremity surgery were enrolled. Following successful regional anesthesia, DMT was administered at a rate of 4 µg/kg/h until reaching loss of consciousness (LOC). The administered dose of DMT per body weight until LOC (DMTLOC; µg/kg) was evaluated. The infusion was maintained at a rate of 0.2–0.7 µg/kg/h during the surgery. At the end of surgery, the elapsed time to a BIS value of 90 (TBIS90; s) was recorded. Linear regression models were used to identify potential predictors of DMTLOC and TBIS90. (3) Results: One hundred patients were analyzed. There were negative relationships between DMTLOC and age (r = −0.297, p = 0.003) and DMTLOC and body mass index (BMI) (r = −0.425, p LOC (r2 = 0.259, p BIS90. (4) Conclusions: The results of this study suggest that initial loading of DMT should be carefully titrated to minimize risk in elderly and obese surgical populations