Decrease of Ca3Co4O9+δ thermal conductivity by Yb-doping

In this study, the effect of Yb-substitution on the structural, electrical and thermal transport properties of the CaCoO system has been investigated in the low temperature region (between 10 and 300 K). The resistivity of samples increases with raising the Yb-concentration in the system. All the samples show a metal-semiconductor transition below 85 K. In the analysis based on Strongly Correlated Fermi Liquid Model, an increased bandwidth and a reduced electronic correlation are found. It has also been found that the energy gap, E , value also decreases with Yb-substitution. The samples show positive thermoelectric power, indicating that dominant charge carriers are holes in all the samples. The thermoelectric power value decreases with Yb-substitution. From Mott equation, it is determined that the Fermi energy and hole concentration decrease in the Yb-susbtituted samples, compared to the undoped ones. Thermal conductivity, κ, is decreased in about 50% of the measured in undoped samples for the 0.01 and 0.03 Yb-doped samples at 300 K. Highest figure of merit, ZT, value is found to be 5.4 10 at 300 K for the unsubstituted sample and the ZT value decreases by the substitution.The authors wish to thank the MINECO-FEDER (Project MAT2013-46505-C3-1-R) and the Gobierno de Aragón and Fondo Social Europeo (Research Groups T12 and T87) for financial support.Peer Reviewe

Effect of secondary annealing process on critical current density in highly textured Bi-2212 superconducting system

Bi-2212 samples prepared by a solid-state reaction technique have been grown from the melt using the laser floating zone method. After annealing the as-grown bars, the samples showed a good grain alignment and a high transport critical current density. Secondary annealing processes were performed on the annealed samples with the aim of producing Bi-2212 phase controlled decomposition. Hence, the Bi-2201 phase and the secondary phases, which act as effective pinning centers, were obtained with the secondary annealing process. After these thermal treatments, the transport critical current densities of samples significantly increased, when compared to the annealed ones. The maximum critical current density was achieved when the samples were subjected to secondary annealing at 680°C for 168 h with an improvement of ~80%, compared to the annealed ones. Moreover, it was found that magnetization of the secondarily annealed samples was also increased. The magnetic critical current densities in these secondary annealed samples were about 3 times higher than the values obtained for the annealed ones. These results clearly indicate that the secondary annealing processes lead to the formation of effective pinning centers in the bulk material.The authors acknowledge financial support from the Gobierno de Aragón (Grupos de Investigacion Consolidados T12 and T87) and the Spanish MINECO-FEDER (Project MAT2013-46505-C3-1-R).Peer Reviewe

Critical flow prediction by system codes – Recent analyses made within the FONESYS network

A benchmark activity on Two-Phase Critical Flow (TPCF) prediction was conducted in the framework of the Forum & Network of System Thermal-Hydraulics Nuclear Reactor Thermal-Hydraulics (FONESYS). FONESYS is a network among code developers who share the common objective to strengthen current technology. The aim of the FONESYS Network is to highlight the capabilities and the robustness as well as the limitations of current SYSTH codes to predict the main phenomena during transient scenarios in nuclear reactors for safety issues. Six separate effect test facilities, more than 90 tests, both in steady and transient conditions, were considered for the activity. Moreover, two ideal tests were designed for code to code comparison in clearly defined conditions. Overall eight System Thermal-Hydraulic (SYS-TH) codes were adopted, mostly by the developers themselves, ensuring the minimization of the user effect. Results from selected tests were also compared against Delayed Equilibrium Model, not yet implemented in industrial version of SYS-TH codes. Generally, the results of the benchmark show an improvement of the capability of SYS-TH codes to predict TPCF in the last three decades. However, predicting break flowrate remains a major source of uncertainty in accidental transient simulations of Water-Cooled Nuclear Reactors (WCNR). A set of possible actions is proposed to go beyond the current limitations of choked flow models. More detailed guidelines for using 0-D choked flow models is possible by using the experience gained by the benchmark results as well as all available validation results. Progress in understanding and 1-D modelling of flashing and choked flow might be achieved by a deeper physical analysis leading to more mechanistic models based on specific flow regime maps for high speed flow. Also the use of advanced 3-D numerical tools may help to understand and predict the complex 3-D geometrical effect

Lymph node metastasis in grossly apparent clinical stage Ia epithelial ovarian cancer: Hacettepe experience and review of literature

Background Lymphadenectomy is an integral part of the staging system of epithelial ovarian cancer. However, the extent of lymphadenectomy in the early stages of ovarian cancer is controversial. The objective of this study was to identify the lymph node involvement in unilateral epithelial ovarian cancer apparently confined to the one ovary (clinical stage Ia). Methods A prospective study of clinical stage I ovarian cancer patients is presented. Patient's characteristics and tumor histopathology were the variables evaluated. Results Thirty three ovarian cancer patients with intact ovarian capsule were evaluated. Intraoperatively, neither of the patients had surface involvement, adhesions, ascites or palpable lymph nodes (supposed to be clinical stage Ia). The mean age of the study group was 55.3 ± 11.8. All patients were surgically staged and have undergone a systematic pelvic and paraaortic lymphadenectomy. Final surgicopathologic reports revealed capsular involvement in seven patients (21.2%), contralateral ovarian involvement in two (6%) and omental metastasis in one (3%) patient. There were two patients (6%) with lymph node involvement. One of the two lymph node metastasis was solely in paraaortic node and the other metastasis was in ipsilateral pelvic lymph node. Ovarian capsule was intact in all of the patients with lymph node involvement and the tumor was grade 3. Conclusion In clinical stage Ia ovarian cancer patients, there may be a risk of paraaortic and pelvic lymph node metastasis. Further studies with larger sample size are needed for an exact conclusion.PubMedWoSScopu

Physical Property Characterization of Bulk MgB2 Superconductor

We report synthesis, structure/micro-structure, resistivity under magnetic field [R(T)H], Raman spectra, thermoelectric power S(T), thermal conductivity K(T), and magnetization of ambient pressure argon annealed polycrystalline bulk samples of MgB2, processed under identical conditions. The compound crystallizes in hexagonal structure with space group P6/mmm. Transmission electron microscopy (TEM) reveals electron micrographs showing various types of defect features along with the presence of 3-4nm thick amorphous layers forming the grain boundaries of otherwise crystalline MgB2. Raman spectra of the compound at room temperature exhibited characteristic phonon peak at 600 cm-1. Superconductivity is observed at 37.2K by magnetic susceptibility C(T), resistivity R(T), thermoelectric power S(T), and thermal conductivity K(T) measurements. The power law fitting of R(T) give rise to Debye temperature at 1400K which is found consistent with the theoretical fitting of S(T), exhibiting ThetaD of 1410K and carrier density of 3.81x 1028/m3. Thermal conductivity K(T) shows a jump at 38K, i.e., at Tc, which was missing in some earlier reports. Critical current density (Jc) of up to 105 A/cm2 in 1-2T (Tesla) fields at temperatures (T) of up to 10K is seen from magnetization measurements. The irreversibility field, defined as the field related to merging of M(H) loops is found to be 78, 68 and 42 kOe at 4, 10 and 20K respectively. The superconducting performance parameters viz. irreversibility field (Hirr) and critical current density Jc(H) of the studied MgB2 are improved profoundly with addition of nano-SiC and nano-Diamond. The physical property parameters measured for polycrystalline MgB2 are compared with earlier reports and a consolidated insight of various physical properties is presented.Comment: 41 pages TEXT+Fig

Inactivation of the FLCN Tumor Suppressor Gene Induces TFE3 Transcriptional Activity by Increasing Its Nuclear Localization

Germline mutations in a tumor suppressor gene FLCN lead to development of fibrofolliculomas, lung cysts and renal cell carcinoma (RCC) in Birt-Hogg-Dubé syndrome. TFE3 is a member of the MiTF/TFE transcription factor family and Xp11.2 translocations found in sporadic RCC involving TFE3 result in gene fusions and overexpression of chimeric fusion proteins that retain the C-terminal DNA binding domain of TFE3. We found that GPNMB expression, which is regulated by MiTF, was greatly elevated in renal cancer cells harboring either TFE3 translocations or FLCN inactivation. Since TFE3 is implicated in RCC, we hypothesized that elevated GPNMB expression was due to increased TFE3 activity resulting from the inactivation of FLCN.TFE3 knockdown reduced GPNMB expression in renal cancer cells harboring either TFE3 translocations or FLCN inactivation. Moreover, FLCN knockdown induced GPNMB expression in FLCN-restored renal cancer cells. Conversely, wildtype FLCN suppressed GPNMB expression in FLCN-null cells. FLCN inactivation was correlated with increased TFE3 transcriptional activity accompanied by its nuclear localization as revealed by elevated GPNMB mRNA and protein expression, and predominantly nuclear immunostaining of TFE3 in renal cancer cells, mouse embryo fibroblast cells, mouse kidneys and mouse and human renal tumors. Nuclear localization of TFE3 was associated with TFE3 post-translational modifications including decreased phosphorylation.Increased TFE3 activity is a downstream event induced by FLCN inactivation and is likely to be important for renal tumor development. This study provides an important novel mechanism for induction of TFE3 activity in addition to TFE3 overexpression resulting from Xp11.2 translocations, suggesting that TFE3 may be more broadly involved in tumorigenesis

Maxillofacial injuries associated with intimate partner violence in women

<p>Abstract</p> <p>Background</p> <p>The facial region has been the most common site of injury following violent episodes. The purpose of this study was to determine the prevalence and pattern of maxillofacial injuries associated with intimate partner violence (IPV) in women treated at a single facility in Malaysia.</p> <p>Methods</p> <p>A retrospective review of 242 hospital records of female IPV victims who were seen at the One-Stop Crisis Centre (OSCC) in Hospital Raja Perempuan Zainab II, Kelantan over a two-year period (January 1, 2005 to December 31, 2006) was performed. A structured form was used for data collection. Information regarding the anatomical sites of injuries, types of injuries, and mechanisms of assault were obtained.</p> <p>Results</p> <p>Most victims were married (85.1%), were injured by the husband (83.5%), and had at least one previous IPV episode (85.5%). Injury to the maxillofacial region was the most common (50.4%), followed by injury to the limbs (47.9%). In 122 cases of maxillofacial injuries, the middle of the face was most frequently affected (60.6%), either alone or in combination with the upper or lower third of the face. Injury to soft tissues (contusions, abrasions and lacerations) was the most common (87.7%).</p> <p>Conclusions</p> <p>This study indicates there is a high prevalence of maxillofacial injuries associated with IPV among women treated at the OSCC in Kelantan, Malaysia.</p

Laser-induced modification of the patellar ligament tissue: comparative study of structural and optical changes

The effects of non-ablative infrared (IR) laser treatment of collagenous tissue have been commonly interpreted in terms of collagen denaturation spread over the laser-heated tissue area. In this work, the existing model is refined to account for the recently reported laser-treated tissue heterogeneity and complex collagen degradation pattern using comprehensive optical imaging and calorimetry toolkits. Patella ligament (PL) provided a simple model of type I collagen tissue containing its full structural content from triple-helix molecules to gross architecture. PL ex vivo was subjected to IR laser treatments (laser spot, 1.6 mm) of equal dose, where the tissue temperature reached the collagen denaturation temperature of 60 ± 2°C at the laser spot epicenterin the first regime, and was limited to 67 ± 2°C in the second regime. The collagen network was analyzed versus distance from the epicenter. Experimental characterization of the collagenous tissue at all structural levels included cross-polarization optical coherence tomography, nonlinear optical microscopy, light microscopy/histology, and differential scanning calorimetry. Regressive rearrangement of the PL collagen network was found to spread well outside the laser spot epicenter (>2 mm) and was accompanied by multilevel hierarchical reorganization of collagen. Four zones of distinct optical and morphological properties were identified, all elliptical in shape, and elongated in the direction perpendicular to the PL long axis. Although the collagen transformation into a random-coil molecular structure was occasionally observed, it was mechanical integrity of the supramolecular structures that was primarily compromised. We found that the structural rearrangement of the collagen network related primarily to the heat-induced thermo-mechanical effects rather than molecular unfolding. The current body of evidence supports the notion that the supramolecular collagen structure suffered degradation of various degrees, which gave rise to the observed zonal character of the laser-treated lesion

The training needs of Turkish emergency department personnel regarding intimate partner violence

<p>Abstract</p> <p>Background</p> <p>Violence against females is a widespread public health problem in Turkey and the lifetime prevalence of IPV ranges between 34 and 58.7%. Health care workers (HCW) sometimes have the unique opportunity and obligation to identify, treat, and educate females who are abused. The objective of this study was to evaluate the knowledge, attitudes, and experiences of the emergency department (ED) staff regarding intimate partner violence (IPV) at a large university hospital in Turkey.</p> <p>Methods</p> <p>A cross-sectional study was conducted in a large university hospital via questionnaire. The study population consisted of all the nurses and physicians who worked in the ED during a two month period (n = 215). The questionnaire response rate was 80.5% (41 nurses and 132 physicians). The main domains of the questionnaire were knowledge regarding the definition of IPV, clinical findings in victims of IPV, legal aspects of IPV, attitudes towards IPV, knowledge about the characteristics of IPV victims and abusers, and professional and personal experiences and training with respect to IPV.</p> <p>Results</p> <p>One-half of the study group were females, 76.3% were physicians, and 89.8% had no training on IPV. The majority of the nurses (89.5%) and physicians (71.1%) declared that they were aware of the clinical appearance of IPV. The mean of the knowledge scores on clinical knowledge were 8.84 ± 1.73 (range, 0–10) for acute conditions, and 4.51 ± 3.32 for chronic conditions. The mean of the knowledge score on legal procedures and the legal rights of the victims was 4.33 ± 1.66 (range, 0–7). At least one reason to justify physical violence was accepted by 69.0% of females and 84.7% of males, but more males than females tended to justify violence (chi square = 5.96; p = 0.015). However, both genders accepted that females who experienced physical violence should seek professional medical help.</p> <p>Conclusion</p> <p>The study participants' knowledge about IPV was rather low and a training program is thus necessary on this issue. Attention must be given to the legal aspects and clinical manifestations of IPV. The training program should also include a module on gender roles in order to improve the attitudes towards IPV.</p