HT2005-72602 MEASUREMENTS OF THERMOELECTRIC PROPERTIES OF BISMUTH TELLURIDE NANOWIRES

ABSTRACT Theoretical calculations have predicted that nanowire materials may have enhanced thermoelectric figure of merit compared to their bulk counterparts due to classical and quantum size effects. We have measured the thermoelectric properties of bismuth telluride nanowires deposited using an electrochemical deposition method in porous anodized alumina templates with the average pore size of about 60 nm. Transmission electron microscopy results of these nanowires showed that the nanowires were single crystalline with a composition of 54% Te and 46% Bi and the thickness of the surface oxide layer was in the range of 5-10 nm. The thermal conductance and Seebeck coefficient of the nanowires were measured using a microfabricated device that consists of two suspended membranes, across which the nanowire sample was placed. The obtained Seebeck coefficient of a bundle consisting of two 100 nm bismuth telluride nanowires increased with increasing temperature from 160 K to 360 K, and the room temperature value was 260 µV/K, which was 60% higher than the bulk value. The thermal conductance of the sample also increased with increasing temperature from 25 K to 360 K. Current design of the microdevice does not allow for fourprobe electrical resistance measurement of the nanowire. We have measured the four-probe electrical resistance of a 57 nm diameter and a 43 nm diameter bismuth telluride nanowires from the same template, and found that the room-temperature electrical conductivity of the nanowires was close to the bulk value and showed much weaker temperature dependence than bulk electrical conductivity

Experimental study on the influence of recycled aggregates on the mechanical properties of concrete

Construction solid waste has become an important environmental pollution source in the city, and the treatment and application of construction solid waste has become the focus of attention. Construction waste recycled aggregates have defects such as high water absorption and micro cracks, which affect its extensive application. In order to improve the utilization rate of recycled aggregates, the influence of different replacement rates of recycled aggregates on the mechanical properties of concrete is studied in this paper. The results show that with the increase of replacement rate of recycled aggregates, the 3-day, 7-day and 28-day compressive strength, splitting strength and cohesive force of concrete decrease gradually, but the mechanical properties of concrete decrease slowly at 3 days and 7 days, and decrease obviously at 28 days. Moreover, with the increase of replacement rate of recycled aggregates, the decline trend of mechanical properties is not obvious. Compared with natural aggregate concrete, the 28-day compressive strength, splitting strength and cohesive force of 100% recycled aggregate concrete are reduced by 16.1%, 20.1% and 18.1% respectively, but the mechanical properties meet the requirements of C30 concrete, which provides a reference for engineering application

A model for predicting overall survival in bladder cancer patients with signet ring cell carcinoma: a population-based study

Abstract Introduction This study is to examine the predictors of survival and to construct a nomogram for predicting the overall survival (OS) of primary bladder signet ring cell carcinoma (SRCC) patients based on the analysis of the Surveillance, Epidemiology, and End Results (SEER) database. Methods A total of 219 eligible patients diagnosed with SRCC were analyzed using the 2004–2015 data from SEER database. Univariate and multivariate Cox regression were used to determine independent prognostic factors, followed by development of a nomogram based on the multivariate Cox regression models. The consistency index (C-index), receiver operating characteristic (ROC) curve, and calibration curve were used to validate the prognostic nomogram. Results The nomograms indicated appreciable accuracy in predicting the OS, with C-index of 0.771 and 0.715, respectively. The area under the curve (AUC) of the nomogram was 0.713 for 1 year, 0.742 for 3 years, and 0.776 for 5 years in the training set, while was 0.730 for 1 year, 0.727 for 3 years, and 0.697 for 5 years in the validation set. The calibration curves revealed satisfactory consistency between the prediction of deviation correction and ideal reference line. Conclusions The prognostic nomogram developed in the analytical data of SEER it provided high accuracy and reliability in predicting the survival outcomes of primary bladder SRCC patients and could be used to comprehensively assess the risk of SRCC. Moreover, they could enable clinicians to make more precise treatment decisions for primary bladder SRCC patients

OPTIMIZATION FOR THE LIQUEFACTION OF MOSO BAMBOO IN PHENOL USING RESPONSE SURFACE METHODOLOGY

Bamboo liquefaction is a key process during bamboo high-value utilization, such as bamboobased nano-carbon fiber manufacturing. Liquefaction parameters have direct effects on the performance of final products. The impact of mass ratio of phenol/bamboo (P/B) powder, temperature, and liquefaction time during moso bamboo liquefaction was studied. All these parameters were studied to perform experiments based on response surface methodology (RSM). Residue content was calculated to evaluate the efficiency of moso bamboo liquefaction. Mathematical models were developed to establish the relationship between the liquefaction parameters and residue content. The results showed that within certain limits the residue content  decreased with the increase of P/B and temperature; however, a further increase of P/B and temperature caused the residue content to increase. In the selected range of liquefaction time in this study, the residue content decreased with the increase of liquefaction time. The optimized combination of liquefaction parameters was 4.5, 163°C, and 46 min for P/B, temperature, and liquefaction time, respectively. The optimized result of residue content from RSM was 7.41934E-008 (%), which meant the bamboo almost completely liquefied. Because of the reasonable error of experiment, the optimized result of residue content from the confirmation experiment was 0.06%.

ABH2 Couples Regulation of Ribosomal DNA Transcription with DNA Alkylation Repair

Transcription has been linked to DNA damage. How the most highly transcribed mammalian ribosomal (rDNA) genes maintain genome integrity in the absence of transcription-coupled DNA damage repair is poorly understood. Here, we report that ABH2/ALKBH2, a DNA alkylation repair enzyme, is highly enriched in the nucleolus. ABH2 interacts with DNA repair proteins Ku70 and Ku80 as well as nucleolar proteins nucleolin, nucleophosmin 1, and upstream binding factor (UBF). ABH2 associates with and promotes rDNA transcription through its DNA repair activity. ABH2 knockdown impairs rDNA transcription and leads to increased single-stranded and double-stranded DNA breaks that are more pronounced in the rDNA genes, whereas ABH2 overexpression protects cells from methyl-methanesulfonate-induced DNA damage and inhibition of rDNA transcription. In response to massive alkylation damage, ABH2 rapidly redistributes from the nucleolus to nucleoplasm. Our study thus reveals a critical role of ABH2 in maintaining rDNA gene integrity and transcription and provides insight into the ABH2 DNA repair function

Effects of Mobile Phone Use on Gait and Balance Control in Young Adults: A Hip–Ankle Strategy

Background: This study aimed to derive the effects of walking while using a mobile phone on balance perturbation and joint movement among young adults. Methods: Sixteen healthy college students with no history of brain injury were tested. The participants were asked to walk under four different conditions: (1) walking, (2) browsing, (3) dialing, and (4) texting. Indicators related to balance control and lower limb kinematic/kinetic parameters were analyzed using the continuous relative phase and statistical nonparametric mapping methods. Results: Walking while using a mobile phone slowed participants’ gait speed and reduced the cadence, stride length, and step length. The posterior tilt angle (0–14%, 57–99%), torque of the hip flexion (0–15%, 30–35%, 75–100%), and angle of the hip flexion (0–28%, 44–100%) decreased significantly. The activation of biceps femoris and gastrocnemius, hip stiffness, and ankle stiffness increased significantly. This impact on gait significantly differed among three dual tasks: texting > browsing > dialing. Conclusion: Che overlap of walking and mobile phone use affects the gait significantly. The “hip–ankle strategy” may result in a “smooth” but slower gait, while this strategy was deliberate and tense. In addition, this adjustment also increases the stiffness of the hip and ankle, increasing the risk of fatigue. Findings regarding this effect may prove that even for young healthy adults, walking with mobile phone use induces measurable adjustment of the motor pattern. These results suggest the importance of simplifying the control of the movement