74 research outputs found
Thermoelectric enhancement in PbTe with K, Na co-doping from tuning the interaction of the light and heavy hole valence bands
The effect of K and K-Na substitution for Pb atoms in the rock salt lattice
of PbTe was investigated to test a hypothesis for development of resonant
states in the valence band that may enhance the thermoelectric power. We
combined high temperature Hall-effect, electrical conductivity and thermal
conductivity measurements to show that K-Na co-doping do not form resonance
states but2 can control the energy difference of the maxima of the two primary
valence sub-bands in PbTe. This leads to an enhanced interband interaction with
rising temperature and a significant rise in the thermoelectric figure of merit
of p-type PbTe. The experimental data can be explained by a combination of a
single and two-band model for the valence band of PbTe depending on hole
density that varies in the range of 1-15 x 10^19 cm^-3.Comment: 8 figure
The Impact of Stochasticity and Its Control on a Model of the Inflammatory Response
The dysregulation of inflammation, normally a self-limited response that initiates healing, is a critical component of many diseases. Treatment of inflammatory disease is hampered by an incomplete understanding of the complexities underlying the inflammatory response, motivating the application of systems and computational biology techniques in an effort to decipher this complexity and ultimately improve therapy. Many mathematical models of inflammation are based on systems of deterministic equations that do not account for the biological noise inherent at multiple scales, and consequently the effect of such noise in regulating inflammatory responses has not been studied widely. In this work, noise was added to a deterministic system of the inflammatory response in order to account for biological stochasticity. Our results demonstrate that the inflammatory response is highly dependent on the balance between the concentration of the pathogen and the level of biological noise introduced to the inflammatory network. In cases where the pro- and anti-inflammatory arms of the response do not mount the appropriate defense to the inflammatory stimulus, inflammation transitions to a different state compared to cases in which pro- and anti-inflammatory agents are elaborated adequately and in a timely manner. In this regard, our results show that noise can be both beneficial and detrimental for the inflammatory endpoint. By evaluating the parametric sensitivity of noise characteristics, we suggest that efficiency of inflammatory responses can be controlled. Interestingly, the time period on which parametric intervention can be introduced efficiently in the inflammatory system can be also adjusted by controlling noise. These findings represent a novel understanding of inflammatory systems dynamics and the potential role of stochasticity thereon
Front-line Bevacizumab in combination with Oxaliplatin, Leucovorin and 5-Fluorouracil (FOLFOX) in patients with metastatic colorectal cancer: a multicenter phase II study
<p>Abstract</p> <p>Purpose</p> <p>To evaluate the efficacy and the toxicity of front line FOLFOX4 combined with bevacizumab in patients with metastatsic CRC (mCRC).</p> <p>Patients and Methods</p> <p>Chemotherapy-naïve patients with mCRC, received bevacizumab (5 mg/kg every 2 weeks d<sub>1</sub>), oxaliplatin (85 mg/m<sup>2 </sup>on d<sub>1</sub>), leucovorin (200 mg/m<sup>2</sup>) on days 1 and 2 and 5-Fluorouracil (400 mg/m<sup>2 </sup>as i.v. bolus and 600 mg/m<sup>2 </sup>as 22 h i.v. continuous infusion on days 1 and 2) every 2 weeks.</p> <p>Results</p> <p>Fifty three patients (46 with a PS 0–1) were enrolled. Complete and partial response was achieved in eight (15.1%) and 28 (52.8%) patients, respectively (ORR: 67.9%; 95% C.I.: 53.8%–92%); 11 (20.7%) patients had stable disease and six (11.3%) progressive disease. With a median follow up period of 13.5 months, time to tumor progression was 11 months while the median survival has not yet been reached; the probability of 1-, 2- and 3- year survival was 79.8%, 63.8% and 58.3%, respectively; Two patients relapsed during the follow up period. Eight (15%) patients underwent metastasectomy with R0 resections. Grade 3–4 neutropenia occurred in 15.1% of patients and one (1.9%) of them presented febrile neutropenia. Non-hematologic toxicity included grade 3 diarrhea (7.6%) and grade 2 and 3 neurotoxicity in 16.9 and 15.1% of patients, respectively. One (1.9%) patient presented pulmonary embolism and one (1.9%) cardiac ischaemia. There was one (1.9%) sudden death after the first cycle.</p> <p>Conclusion</p> <p>The combination of FOLFOX4/bevacizumab appears to be highly effective, well tolerated and merits further evaluation in patients with mCRC.</p
Advanced trauma life support course for medical students. A new era?
IntroductionTrauma represents a major public health issue and is one of the leading causes of death and disability worldwide. A systematic approach toward dealing with trauma patients was facilitated through the ATLS program, which has become a milestone in trauma care. Our new ATLS course for medical students was set in motion in 2015. Our aim was to make medical students familiar with trauma patients interactively, through a program like ATLS, and here we present the results of this endeavor.MethodsA two-day ATLS-Medical Student (MS) course was offered from November 2015 to July 2018, and analysis was performed retrospectively on the data gathered over a three-month period through online questionnaires. Before graduating, 261 newly qualified medical doctors were interviewed and evaluated as part of the ATLS course.ResultsAfter the course, the vast majority of medical students (251 MSs; 96.16%) felt more capable of managing severely injured patients and 58% of students felt that the medical services they offered were better due to the ATLS training. Regarding the educational fee for the course, 56.7% of the students reported that they felt the fee of 100 euros was fair.DiscussionThe interactive format of the course, which differs from more traditional methods of teaching, has been endorsed by medical students. Though they lack clinical experience, that does not prohibit them from acquiring more specialized or specific knowledge, enabling them to excel. Most of the students improved their skillset either in theoretical knowledge, practical skills, or even in the emotional component of the course, i.e., dealing with treating a severely injured patient. It was decided that the program would be re-evaluated and extended to all Greek Medical Schools.ConclusionThe advantage of providing doctors with trauma training at the beginning of their careers is evident. For that reason, it was decided that the program would be re-evaluated and extended to all Greek Medical Schools
Central nervous system relapse in patients with breast cancer is associated with advanced stages, with the presence of circulating occult tumor cells and with the HER2/neu status
INTRODUCTION: To evaluate the incidence of central nervous system (CNS) involvement in patients with breast cancer treated with a taxane-based chemotherapy regimen and to determine predictive factors for CNS relapse. METHODS: The medical files of patients with early breast cancer (n = 253) or advanced stage breast cancer (n = 239) as well of those with other solid tumors (n = 336) treated with or without a taxane-based chemotherapy regimen during a 42-month period were reviewed. HER2/neu overexpression was identified by immunohistochemistry, whereas cytokeratin 19 (CK-19) mRNA-positive circulating tumor cells (CTCs) in the peripheral blood were identified by real-time PCR. RESULTS: The incidence of CNS relapse was similar in patients suffering from breast cancer or other solid tumors (10.4% and 11.4%, respectively; P = 0.517). The incidence of CNS relapse was significantly higher in breast cancer patients with advanced disease (P = 0.041), visceral disease and bone disease (P = 0.036), in those who were treated with a taxane-containing regimen (P = 0.024), in those with HER2/neu-overexpressing tumors (P = 0.022) and, finally, in those with detectable CK-19 mRNA-positive CTCs (P = 0.008). Multivariate analysis revealed that the stage of disease (odds ratio, 0.23; 95% confidence interval, 0.007–0.23; P = 0.0001), the HER2/neu status (odds ratio, 29.4; 95% confidence interval, 7.51–101.21; P = 0.0001) and the presence of CK-19 mRNA-positive CTCs (odds ratio, 8.31; 95% confidence interval, 3.97–12.84; P = 0.001) were independent predictive factors for CNS relapse. CONCLUSION: CNS relapses are common among breast cancer patients treated with a taxane-based chemotherapy regimen, patients with HER2/neu-positive tumor and patients with CK-19 mRNA-positive CTCs
Management of adrenal incidentalomas - a European Society of Endocrinology Clinical Practice Guideline in collaboration with the European Network for the Study of Adrenal Tumors
Diabetes mellitus: pathophysiological changes and therap
Quantum -divergences via Nussbaum-Szko{\l}a Distributions with applications to Petz-R\'enyi and von Neumann Relative Entropy
We prove that the quantum -divergence of two states (density operators on
a Hilbert space of finite or infinite dimensions) is same as the classical
-divergence of the corresponding Nussbaum-Szko{\l}a distributions. This
provides a general framework to study most of the known quantum entropic
quantities using the corresponding classical entities. In this spirit, we study
the Petz-R\'enyi and von Neumann relative entropy and prove that these quantum
entropies are equal to the corresponding classical counterparts of the
Nussbaum-Szko{\l}a distributions. This is a generalization of a finite
dimensional result that was proved by Nussbaum and Szko{\l}a [Ann. Statist. 37,
2009, 2] to the infinite dimensions. We apply classical results about R\'enyi
and Kullback-Leibler divergences to obtain new results and new proofs for some
known results about the quantum relative entropies. Most important among these
are (i) a quantum Pinsker type inequality in the infinite dimensions, and (ii)
necessary and sufficient conditions for the finiteness of the Petz-R\'enyi
-relative entropy for any order . Furthermore,
we construct an example to show that the information theoretic definition of
the von Neumann relative entropy is different from Araki's definition of
relative entropy when the dimension of the Hilbert space is infinite. This
discrepancy can be bridged using the notion of the distribution of an unbounded
positive selfadjoint operator with respect to a positive compact operator and
Haagerup's extension of the trace. Our results are valid in both finite and
infinite dimensions and hence can be applied to continuous variable systems as
well.Comment: Major Revision. New results about quantum -divergences are added.
New formula for Petz-R\'enyi and von Neumann relative entropy are obtained
using the idea of distribution of an observable. We thank Mark Wilde and
Mil\'an Mosonyi for providing useful comments and relevant references for the
earlier version. 38 page
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