Reduction of thermal conductivity in PbTe:Tl by alloying with TlSbTe_2

A series of s ingle-phase polycrystalline (TlSbTe_2)_x(Tl_(0.02)Pb_(0.98)Te)_(1-x) (x=0, 0.05, 0.1) compounds were made to reduce thermal conductivity while maintaining the enhanced Seebeck coefficients found in PbTe doped with Tl. Transport property measurements confirmed that high Seebeck coefficients from doping with Tl are retained by alloying with TlSbTe_2. At the same time, a thermal conductivity as low as 0.8 W/mK at room temperature, and 0.6 W/mK at 673 K was observed, corresponding to a 30% reduction in lattice thermal conductivity at 673 K compared with 2% Tl-PbTe. However, the maximum zT in this system is 0.8 (at 623 K), which is lower than that of 2% Tl-PbTe prepared in this work (1.2 at 673 K) owing to a decrease of the charge-carrier mobility when alloying with TlSbTe_2. Possible influences on the mobility are discussed

Side-on measurement of hydrodynamics of laser-driven plasmas with high space- and time-resolution x-ray imaging technique

Copyright 2003 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Review of Scientific Instruments, 74(3), 2198-2201, 2003 and may be found at http://dx.doi.org/10.1063/1.153785

Enhancement of Thermoelectric Efficiency in PbTe by Distortion of the Electronic Density of States

The efficiency of thermoelectric energy converters is limited by the material thermoelectric figure of merit (zT). The recent advances in zT based on nanostructures limiting the phonon heat conduction is nearing a fundamental limit: The thermal conductivity cannot be reduced below the amorphous limit. We explored enhancing the Seebeck coefficient through a distortion of the electronic density of states and report a successful implementation through the use of the thallium impurity levels in lead telluride (PbTe). Such band structure engineering results in a doubling of zT in p-type PbTe to above 1.5 at 773 kelvin. Use of this new physical principle in conjunction with nanostructuring to lower the thermal conductivity could further enhance zT and enable more widespread use of thermoelectric systems

Predictive Factors of Rectal Toxicity After Permanent iodine-125 Seed Implantation: Prospective Cohort Study in 2339 Patients

Purpose: To evaluate the incidence and the associated factors of rectal toxicity in patients with prostate cancer undergoing permanent seed implantation (PI) with or without external beam radiation therapy (EBRT) in a nationwide prospective cohort study in Japan (J-POPS) during the first 2 years. Methods and materials: A total of 2,339 subjects were available for the analyses. Rectal toxicity was evaluated using the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. Results: The 3-year cumulative incidence for grade ≥2 rectal toxicity was 2.88%, 1.76%, and 6.53% in all subjects, PI group and EBRT combination therapy group, respectively. On multivariate analysis, among all subjects, grade ≥2 rectal toxicity was associated with rectal volumes receiving 100% of the prescribed dose (R100; p Conclusions: Rectal toxicity was relatively rare in this study compared with previous reports. For Japanese prostate cancer patients, R100 < 1 mL in both PI and EBRT combination therapy groups and interactive planning in EBRT combination therapy group may be effective in decreasing the incidence of rectal toxicity

Construction of Integrated Genetic Map between Various Existing DNA Markers and Newly Developed P450-related PBA Markers in Diploid Potato (Solanum tuberosum)

We have generated estimates of the genomic distribution of newly developed molecular markers, which are P450-based analogues (PBAs), in diploid potato (Solanum tuberosum, 2n=2x=24) based on functional genomics. A total of 401 markers, including 111 SSR, 33 RFLP, 87 RFLP-STS, 45 CAPS, 94 RAPD, 15 PBA, 9 AFLP, 3 RGL and 4 ISSR markers, were employed in a parental polymorphism survey. A total of 127 out of 401 markers (172 loci) displayed polymorphisms between parents and were confirmed to show segregation in partial progenies. These selected 127 markers were then tested for their possible use for a whole mapping population. The subsequent results of genetic mapping of the PBAs revealed that they were distributed on at least 8 chromosomes, suggesting that they have a significant potential not only as tools for assessing genetic diversity but also as effective markers to construct more detailed genetic maps of potato, in conjunction with existing identified genetic loci. To integrate the information from existing maps into our mapping study, we performed a comparative analysis between two representative maps (RFLP and SSR-based) with our PBA map. Based on the subsequent results, we predict that our map will be useful as a bridge between the existing genetic maps of potato and will enable to integrate information about different markers

Exact ground-state correlation functions of the one-dimensional strongly correlated electron models with the resonating-valence-bond ground state

We investigate the one-dimensional strongly correlated electron models which have the resonating-valence-bond state as the exact ground state. The correlation functions are evaluated exactly using the transfer matrix method for the geometric representations of the valence-bond states. In this method, we only treat matrices with small dimensions. This enables us to give analytical results. It is shown that the correlation functions decay exponentially with distance. The result suggests that there is a finite excitation gap, and that the ground state is insulating. Since the corresponding non-interacting systems may be insulating or metallic, we can say that the gap originates from strong correlation. The persistent currents of the present models are also investigated and found to be exactly vanishing.Comment: 59 pages, REVTeX 3.0, Figures are available on reques

Muscle mass, quality, and strength; physical function and activity; and metabolic status in cachectic patients with head and neck cancer

Background & aims: Cancer cachexia is commonly associated with poor prognosis in patients with head and neck cancer (HNC). However, its pathophysiology and treatment are not well established. The current study aimed to assess the muscle mass/quality/strength, physical function and activity, resting energy expenditure (REE), and respiratory quotient (RQ) in cachectic patients with HNC. Methods: This prospective cross-sectional study analyzed 64 patients with HNC. Body composition was measured via direct segmental multifrequency bioelectrical impedance analysis, and muscle quality was assessed using echo intensity on ultrasonography images. Muscle strength was investigated utilizing handgrip strength and isometric knee extension force (IKEF). Physical function was evaluated using the 10-mwalking speed test and the five times sit-to-stand (5-STS) test. Physical activity was examined using a wearable triaxial accelerometer. REE and RQ were measured via indirect calorimetry. These parameters were compared between the cachectic and noncachectic groups. Results: In total, 23 (36%) patients were diagnosed with cachexia. The cachectic group had a significantly lower muscle mass than the noncachectic group. Nevertheless, there was no significant difference in terms of fat between the two groups. The cachectic group had a higher quadriceps echo intensity and a lower handgrip strength and IKEF than the noncachectic group. Moreover, they had a significantly slower normal and maximum walking speed and 5 STS speed. The number of steps, total activity time, and time of activity (<3 Mets) did not significantly differ between the two groups. The cachectic group had a shorter time of activity (≥3 Mets) than the noncachectic group. Furthermore, the cachectic group had a significantly higher REE/body weight and REE/fat free mass and a significantly lower RQ than the noncachectic group. Conclusions: The cachectic group had a lower muscle mass/quality/strength and physical function and activity and a higher REE than the noncachectic group. Thus, REE and physical activity should be evaluated to determine energy requirements. The RQ was lower in the cachectic group than that in the noncachectic group, indicating changes in energy substrate. Further studies must be conducted to examine effective nutritional and exercise interventions for patients with cancer cachexia

Stress-impaired reward pathway promotes distinct feeding behavior patterns

Although dietary behaviors are affected by neuropsychiatric disorders, various environmental conditions can have strong effects as well. We found that mice under multiple stresses, including social isolation, intermittent high-fat diet, and physical restraint, developed feeding behavior patterns characterized by a deviated bait approach (fixated feeding). All the tested stressors affected dopamine release at the nucleus accumbens (NAcc) shell and dopamine normalization reversed the feeding defects. Moreover, inhibition of dopaminergic activity in the ventral tegmental area that projects into the NAcc shell caused similar feeding pattern aberrations. Given that the deviations were not consistently accompanied by changes in the amount consumed or metabolic factors, the alterations in feeding behaviors likely reflect perturbations to a critical stress-associated pathway in the mesolimbic dopamine system. Thus, deviations in feeding behavior patterns that reflect reward system abnormalities can be sensitive biomarkers of psychosocial and physical stress