The charge carrier transport in anthracene single crystals has been studied by means of field-effect transistor (FET) structure. The FET mobility (μFET) revealed the nonmonotonous, reliant on gate-voltage (Vg), temperature dependence with the maximum μFET∼0.02cm2∕Vs at T∼170–180K and Vg∼−30V. At temperatures below 180K the mobility decreases and becomes thermally activated with the Vg-dependent activation energy Ea∼40–70meV governed by shallow traps. The space-charge-limited current is the dominant transport mechanism in FET structures based on anthracene single crystals.

We propose that head-shaking nystagmus in lateral medullary infarction is due to unilaterally impaired nodulouvular inhibition of the velocity storage. This proposal is consistent with the results of neuroanatomic studies that demonstrate that Purkinje cells controlling velocity storage in the nodulus and ventral uvula project to the caudal or middle portion of the vestibular nuclei, whereas those subserving visual-vestibular interactions in the flocculus project to the more rostral portion.

Although Korean cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) mutation carriers show similar clinical and MRI findings, these abnormalities appear less frequently than in other populations. Relatively frequent microbleedings on gradient echo imaging suggest that treatment should be individualized according to MRI findings. The novel mutation of R75P, not involving a cysteine residue, is related to less frequent involvement of the anterior temporal area, thus broadening the spectrum of CADASIL.

Although almost all primary colorectal lymphomas are of B-cell lineage in Western countries, primary colorectal T-cell lymphomas are not uncommon in the East. The aim of this study was to review the clinical characteristics and treatment outcomes of primary colorectal lymphomas, with special emphasis on the differences between T-cell and B-cell lymphomas. Ninety-five cases of primary colorectal lymphomas that satisfied Dawson's criteria were identified from the clinical databases of 13 university hospitals in Korea. The mean age at the time of presentation was 51.1 years and the male:female ratio was 64:31. The clinical information, including endoscopic and histological characteristics, was retrospectively analyzed. Of the primary colorectal lymphomas, 78 cases (82.1%) were of B-lineage and 17 cases (17.9%) were of T-cell lineage. Patients with T-cell lymphomas presented at a younger age than patients with B-cell lymphomas (42.8 vs 52.9 years, respectively; P = 0.016). The most common presenting symptom was abdominal pain (87.1%) for B-cell lymphomas, whereas hematochezia or night fever was more common for T-cell lymphomas (52.9% and 35.3%, respectively). The most common endoscopic type was fungating mass (54.0%) for B-cell lymphomas and ulcerative/ulcero-infiltrative lesions (80.0%) for T-cell lymphomas. Intussusception was more common in B-cell lymphomas than in T-cell lymphomas (30.8% vs 5.9%, respectively; P = 0.035), but perforation was more common in T-cell lymphomas than in B-cell lymphomas (23.5% vs 3.8%, respectively; P = 0.005). The prognosis was significantly worse for T-cell lymphomas than for B-cell lymphomas (P = 0.002). Primary colorectal T-cell lymphomas are characterized by multifocal ulcerative lesions in relatively young patients, a high rate of hematochezia, fever, or perforation, and a poor prognosis even for cases of localized disease.

Measurements of temperature in low-pressure, diamond-forming, premixed flames are described. Optical emission spectroscopy was used to determine the rotational temperature of CH radicals in the flame by analyzing the spectra of the R-branch of the A 2Δ→X 2Π(0,0) CH electronic transition near 430 nm. Emission spectroscopic measurements were taken in stagnation-point flames of three different fuel types; CH4–O2, C2H4–O2, and C2H2–O2 flames, all of which have been previously used in the synthesis of diamond films. The emission-based rotational temperatures are found to be in good agreement with temperature measurements from thermocouples for the CH4–O2 flame, when a correction is made to the thermocouple measurements for radiation losses. The measurements show that peak flame temperatures are higher than the adiabatic flame temperatures for both C2H4–O2, and C2H2–O2 flames; a result that is also predicted by a numerical simulation of the stagnation-point strained flame that accounts for detailed finite-rate gas-phase chemistry and heterogeneous surface reactions.

1 We examined whether extremely low frequency electromagnetic fields (ELF-EMF) affect the basal level of cardiovascular parameters and influence of drugs acting on the sympathetic nervous system. 2 Male rats were exposed to sham control and EMF (60 Hz, 20 G) for 1 (MF-1) or 5 days (MF-5). We evaluated the alterations of blood pressure (BP), pulse pressure (PP), heart rate (HR), and the PR interval, QRS interval and QT interval on the electrocardiogram and dysrhythmic ratio in basal level and dysrhythmia induced by beta-adrenoceptor agonists. 3 In terms of the basal levels, there were no statistically significant differences among control, MF-1 and MF-5 in PR interval, QRS interval, mean BP, HR and PP. However, the QT interval, representing ventricular repolarization, was significantly reduced by MF-1 (P < 0.05). 4 (-)-Dobutamine (beta1-adrenoceptor-selective agonist)-induced tachycardia was significantly suppressed by ELF-EMF exposure in MF-1 for the increase in HR (DeltaHR), the decrease in QRS interval (DeltaQRS) and the decrease in QT (DeltaQT) interval. Adrenaline (nonselective beta-receptor agonist)-induced dysrhythmia was also significantly suppressed by ELF-EMF in MF-1 for the number of missing beats, the dysrhythmic ratio, and the increase in BP and PP. 5 These results indicated that 1-day exposure to ELF-EMF (60 Hz, 20 G) could suppress the increase in HR by affecting ventricular repolarization and may have a down-regulatory effect on responses of the cardiovascular system induced by sympathetic agonists.

No abstract

Thermoelectric power (TEP) of high-T C superconductors has been investigated in a wide range of temperature (T C < T < 700 K) for La 2−x Sr x CuO 4 . TEP of La 2−x Sr x CuO 4 shows different temperature dependences in three temperature regions. In the low-temperature region, a positive broad TEP peak is observed near T p , which shifts to lower temperature upon doping. As temperature increases, TEP decreases linearly at intermediate temperature.In the high-temperature region, TEP deviates from the linear temperature dependence at a certain temperature, T h showing a saturation behavior. As the doping concentration increases, the characteristic temperatures, T C , T p , and T h , show systematic changes. In comparison with pseudogap temperature estimated from other experiments, the large pseudogap behavior in TEP at high temperature has been discussed and distinguished from the small pseudogap observed at lower temperature. A possibility of bound pairs formation in the normal state opening the pseudogap at high temperature is discussed briefly. The coexistence of bound pairs and the normal independent carriers for T C < T < T h could be the origin of the intrinsic inhomogeneity.