Carrier trapping and luminescence polarization in quantum dashes

We study experimentally and theoretically polarization-dependent luminescence from an ensemble of quantum-dot-like nanostructures with a very large in-plane shape anisotropy (quantum dashes). We show that the measured degree of linear polarization of the emitted light increases with the excitation power and changes with temperature in a non-trivial way, depending on the excitation conditions. Using an approximate model based on the k.p theory, we are able to relate this degree of polarization to the amount of light hole admixture in the exciton states which, in turn, depends on the symmetry of the envelope wave function. Agreement between the measured properties and theory is reached under assumption that the ground exciton state in a quantum dash is trapped in a confinement fluctuation within the structure and thus localized in a much smaller volume of much lower asymmetry than the entire nanostructure.Comment: 13 pages, 9 figures; considerably extended, additional discussion and new figures include

A Monte Carlo study of the Falicov–Kimball model in the perturbative regime

Finite-temperature properties of the Falicov–Kimball model on the square lattice have been studied in the perturbative regime, i.e. for t/U << 1, where t is the hopping constant and U denotes the Coulomb interaction strength. In our study, we have determined the phase diagram of the model in the second-order of the perturbation theory, where the antiferromagnetic Ising model in the magnetic field emerges. In the fourth-order, where our model constitutes the Ising model with more complicated frustrated antiferromagnetic interactions, the sketch of the phase diagram was established. The Monte Carlo method was employed and the behavior of Binder cumulants based on the order parameters was analyzed to determine the type of ordering and phase boundaries in the diagram

Ocena poziomu wiedzy osób dorosłych na temat resuscytacji krążeniowo : oddechowej (RKO) i użycia automatycznego defibrylatora zewnętrznego (AED) w miejscach publicznych

Wstęp. Wraz z rozwojem cywilizacji, wzrastającym tempem życia, rośnie liczba wypadków i chorób, zwłaszcza chorób układu krążenia. W Polsce średnia liczba zgonów około wypadkowych jest trzy razy wyższa niż średnia europejska. Wiedza na temat pierwszej pomocy jest bardzo ważna wśród społeczeństwa, które stanowi mocny filar niesienia pierwszej pomocy poszkodowanym w nagłych sytuacjach, które są stanami zagrożenia zdrowia i życia. Cel pracy. Celem pracy była ocena i porównanie wiedzy mieszkańców Kielc i Krakowa z zakresu pierwszej pomocy oraz obsługi i zastosowania Automatycznego Defibrylatora Zewnętrznego (AED). Materiał i metody. Grupę badawczą stanowiło 160 osób, z czego 80 osób było z Krakowa, w tym 45 kobiet i 35 mężczyzn i 80 osób z Kielc, w tym 45 kobiet i 35 mężczyzn. Wszyscy re-spondenci byli pełnoletni. W badaniach posłużono się metodą sondażu diagnostycznego bezpośredniego, losowego wykorzys-tując do tego celu narzędzie badawcze w postaci anonimowego kwestionariusza ankiety, opracowanego na bazie Wytycznych Resuscytacji Krążeniowo- Oddechowej 2005 (RKO). Wyniki. Mieszkańcy Krakowa wykazują lepszy poziom wiedzy, aczkolwiek znajomość i obsługa . Respondenci z Krakowa częściej i chętniej uczestniczą w szkoleniach z zakresu BLS-AED i pierwszej pomocy niż respondencki z Kielc. Wnioski. Poziom wiedzy z zakresu udzielania pierwszej pomocy, a przede wszystkim w zakresie resuscytacji krążeniowo - oddechowej i użycia AED przez społeczeństwo z Krakowa i Kielc jest niezadawalający. Istnieje pilna potrzeba wprowadzenia komplementarnego systemu nauczania zagadnień pierwszej pomocy opartego na międzynarodowych standardach, który zagwarantuje odpowiednią jakość edukacji oraz kształtowanie pozytywnych postaw niesienia pomocy, począwszy od wczesnego etapu edukacji szkolnej.Introduction: The number of accidents and diseases, especially cardio-vascular, is increasing along with the develop-ment of civilization and a growing pace of life. In Poland, the average number of accident fatalities is three times higher than the European average. The knowledge of first aid is very im-portant for society, which is a strong pillar of first aid to victims in emergency situations that are dangerous to health and life. The aim of the study: The aim of the study was to assess the knowledge of CPR and first aid in the event of sudden respiratory arrest and cardiac arrest (SCA) and the operation and use of the Automated External Defibrillator (AED). Material and methods: The study group consisted of 160 people, among whom 80 were from Kraków, including 45 women and 35 men and 80 people were from Kielce, including 45 women and 35 men. All the respondents were adults. The method of diagnostic survey was applied in the study. The research instrument was an anonymous survey questionnaire created on the basis of the Car-dio-Pulmonary Resuscitation Guidelines 2005 (CPR). Results: Residents of Kraków have better knowledge of first aid, however the knowledge and operation of the AED among both residents of Kraków and Kielce is inadequate. Respondents from Kraków more often and more willingly participate in BLS-AED and first aid training than respondents from Kielce. Conclusions: The level of knowledge of first aid and especially of Cardio-Pulmonary Resuscitation and the application of the AED is unsatisfactory among residents of Kraków and Kielce. There is an urgent need for a complementary system of first aid instruction which would be based on international standards, and which would ensure an appropriate quality of education and develop a proper attitude among people, starting with the earliest stage of school education

Semiquantitative interpretation of anticardiolipin and antiβ2glycoprotein I antibodies measured with various analytical platforms: communication from the ISTH SSC subcommittee on Lupus Anticoagulant/Antiphospholipid antibodies

Background Antiβ2glycoprotein I (aβ2GPI) and anticardiolipin (aCL) IgG/IgM show differences in positive/negative agreement and titers between solid phase platforms. Method specific semiquantitative categorization of titers could improve and harmonize the interpretation across platforms. Aim To evaluate the traditionally 40/80 units thresholds used for aCL and aβ2GPI for categorization into moderate/high positivity with different analytical systems, and to compare with alternative thresholds. Material and methods aCL and aβ2GPI thresholds were calculated for two automated systems (chemiluminescent immunoassay (CLIA) and multiplex flow immunoassay (MFI)) by ROC-curve analysis on 1108 patient samples, including patients with and without APS, and confirmed on a second population (n=279). Alternatively, regression analysis on diluted standard material was applied to identify thresholds. Thresholds were compared to 40/80 threshold measured by an enzyme linked immunosorbent assay (ELISA). Additionally, likelihood ratios (LR) were calculated. Results Threshold levels of 40/80 units show poor agreement between ELISA and automated platforms for classification into low/moderate/high positivity, especially for aCL/aβ2GPI IgG. Agreement for semiquantitative interpretation of aPL IgG between ELISA and CLIA/MFI improves with alternative thresholds. LR for aPL IgG increase for thrombotic and obstetric APS based on 40/80 thresholds for ELISA and adapted thresholds for the other systems, but not for IgM. Conclusion Use of 40/80 units as medium/high thresholds is acceptable for aCL/aβ2GPI IgG ELISA, but not for CLIA and MFI. Alternative semiquantitative thresholds for non-ELISA platforms can be determined by a clinical approach or by using monoclonal antibodies. Semiquantitative reporting of aPL IgM has less impact on increasing probability for APS

Heat shock proteins in chronic kidney disease

Heat shock proteins (HSP) form a heterogenous, evolutionarily conserved group of molecules with high sequence homology. They mainly act as intracellular chaperones, protecting the protein structure and folding under stress conditions. The extracellular HSP, released in the course of damage or necrosis, play a pivotal role in the innate and adaptive immune responses. They also take part in many pathological processes. The aim of this review is to update the recent developments in the field of HSP in chronic kidney disease (CKD), in regard to three different aspects. The first is the assessment of the role of HSP, either positive or deleterious, in the pathogenesis of CKD and the possibilities to influence its progression. The second is the impact of dialysis, being a potentially modifiable stressor, on HSP and the attempt to assess the value of these proteins as the biocompatibility markers. The last area is that of kidney transplantation and the potential role of HSP in the induction of the immune tolerance in kidney recipients

Matrix metalloproteinases (MMP-2,9) and their tissue inhibitors (TIMP-1,2) as novel markers of stress response and atherogenesis in children with chronic kidney disease (CKD) on conservative treatment

The system of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) may play a key role in atherogenesis of chronic kidney disease (CKD) patients by its impact on matrix accumulation. Connections with inflammation, stress, or endothelial dysfunction are also probable. However, the data on correlations between these parameters in CKD patients are scarce in adults and absent in children. The aim of our study was to evaluate serum concentrations of MMP-2, MMP-9, TIMP-1, and TIMP-2, as well as their correlations with markers of stress response (Hsp90-α, anti-Hsp60), endothelial dysfunction (sE-selectin), and inflammation (high-sensitivity C-reactive protein) in CKD children treated conservatively. Thirty-seven patients were divided into two groups according to the CKD stage (gr.CKDI, 19 children with CKD stages 2–3; gr.CKDII, 18 subjects with CKD stages 4–5). Twenty-four age-matched healthy subjects served as controls. Serum concentrations of MMP-2, MMP-9, TIMP-1, TIMP-2, Hsp90-α, anti-Hsp60, and sE-selectin were assessed by ELISA. Median values of MMP-2, MMP-9, TIMP-1, and TIMP-2 were significantly higher in all CKD children vs. controls and were increased in patients with CKD stages 4–5 vs. CKD stages 2–3. Hsp90-α, anti-Hsp60, sE-selectin, and glomerular filtration rate predicted the values of MMPs and TIMPs. Chronic kidney disease in children is characterized by MMP/TIMP system dysfunction, aggravated by the progression of renal failure. Correlations between examined parameters, heat shock proteins, and markers of endothelial damage suggest the possibility of MMP/TIMP application as indicators of stress response and atherogenesis in children with CKD on conservative treatment

A Pettis-Type Integral and Applications to Transition Semigroups

Motivated by applications to transition semigroups, we introduce the notion of a norming dual pair and study a Pettis-type integral on such pairs. In particular, we establish a sufficient condition for integrability. We also introduce and study a class of semigroups on such dual pairs which are an abstract version of transition semigroups. Using our results, we give conditions ensuring that a semigroup consisting of kernel operators has a Laplace transform which also consists of kernel operators. We also provide conditions under which a semigroup is uniquely determined by its Laplace transform.Comment: Incorporated referee's comments; final versio