Search results for "PBS"
showing 10 items of 31 documents
Preferred Growth Direction by PbS Nanoplatelets Preserves Perovskite Infrared Light Harvesting for Stable, Reproducible, and Efficient Solar Cells
2020
Formamidinium-based perovskite solar cells (PSCs) present the maximum theoretical efficiency of the lead perovskite family. However, formamidinium perovskite exhibits significant degradation in air. The surface chemistry of PbS has been used to improve the formamidinium black phase stability. Here, the use of PbS nanoplatelets with (100) preferential crystal orientation is reported, to potentiate the repercussion on the crystal growth of perovskite grains and to improve the stability of the material and consequently of the solar cells. As a result, a vertical growth of perovskite grains, a stable current density of 23 mA cm(-2), and a stable incident photon to current efficiency in the infr…
Second order reflection from crystals used in soft X-ray spectroscopy
2015
Abstract In this note the ratio of the second to the first order reflection is determined for the KAP and PbSt crystals, for wavelengths corresponding to the Al K-line emission. The source of the radiation was a low-voltage stabilized X-ray tube. The X-rays were detected with a Bragg spectrometer equipped with a proportional counter detector. The signal measured by the proportional counter was subsequently pulse height analyzed.
Ložņu āboliņa (Trifolium repens L.) Eiropas populāciju ģenētiskās daudzveidības salīdzinājums
2021
Ložņu āboliņam ir plašs izplatības areāls – no arktiskiem reģioniem līdz augstkalnu (6000 m) reģioniem. Tas ir plaši izplatīts arī vietās ar augstu vides piesārņojuma līmeni. Maģistra darba mērķis ir noteikt ložņu āboliņa Eiropas populāciju ģenētisko daudzveidību atkarībā no dažādiem augšanas apstākļiem. Ģenētiskās daudzveidības noteikšanai tika izmantota iPBS metode un izstrādāta metode UV-B starojuma izraisītas retrotranspozonu pārvietošanās noteikšanai. Rezultāti liecina, ka analizētā Eiropas populācija iedalās divos lielos klāsteros, atsevišķi izdaloties augstkalnu apgabalam. Secināts, ka augstkalnu reģionos izplatītās populācijas ģenētiski ir atšķirīgas no zemienēs izplatītājām. Analiz…
Development and validation of the Brief Parental Burnout Scale (BPBS).
2021
Since parental burnout can have detrimental consequences for parents, couples, and children, easy-to-use, reliable, and valid practical tools for the early detection of parental burnout are required. We developed and validated a brief scale to identify burned-out parents and parents at burnout risk. In Study 1, we developed the 5-item Brief Parental Burnout scale (BPBs) based on the gold standard measure of parental burnout, the Parental Burnout Assessment (PBA). We applied Item Response Theory Graded Response Model (GRM) analyses on the data of 1,725 Finnish parents. Compared against the PBA total score, the five selected items showed both high sensitivity and specificity in screening pare…
Pozitīvas uzvedības atbalsta stratēģijas 8. klasē
2021
Diplomdarbā autore nodarbojas ar pozitīvas uzvedības stratēģijām, to būtību, pieejām un metodēm. Autore uzskata, ka skolēni var sasniegt labākus rezultātus un uzlabot savu uzvedību, kad skolotāji klasē izmanto pozitīvas uzvedības stratēģijas. Šī pētījuma mērķis ir izpētīt kā pozitīvas uzvedības stratēģijas ietekmē studentu uzvedību un sekmes. Pozitīvā disciplīna ir mācību modelis, kas iesaka izmantot stratēģijas, lai palīdzētu skolotājiem tikt galā ar skolēnu aktivitātēm un attieksmi, kas traucē produktīvam mācību procesam. Autore ir pārliecināta, ka, ieviešot pozitīvas uzvedības stratēģijas, skolotāji spēj izaicinājumus pārvērst par savu stundu iespējām tādā nozīmē, ka klase kļūst par pozi…
Factors affecting the amount and the mode of merocyanine 540 binding to the membrane of human erythrocytes. A comparison with the binding to leukemia…
1995
Abstract In the presence of albumin Merocyanine 540 (MC540) exhibits a very limited binding to the outer surface of the membrane of normal erythrocytes, whereas pronounced binding is observed to leukemia cells. To find out whether this difference is due to differences in the composition or structural organization of the cell membrane we analyzed effects of a number of covalent and non-covalent perturbations of the red cell membrane on the binding and fluorescence characteristics of membrane-bound MC540. It is shown that exposure of the cells to cationic chlorpromazine, neuraminidase or photodynamic treatment with AlPcS 4 as sensitizer caused a limited increase (30–50%) of MC540 binding, tog…
Polybutylene succinate artificial scaffold for peripheral nerve regeneration
2021
Regeneration and recovery of nerve tissues are a great challenge for medicine, and positively affect the quality of life of patients. The development of tissue engineering offers a new approach to the problem with the creation of multifunctional artificial scaffolds that act on various levels in the damaged tissue, providing physical and biochemical support for the growth of nerve cells. In this study, the effects of the use of a tubular scaffold made of polybutylene succinate (PBS), surgically positioned at the level of a sciatic nerve injured in rat, between the proximal stump and the distal one, was investigated. Scaffolds characterization was carried out by scanning electron microscopy …
Anti-inflammatory Function of High-Density Lipoproteins via Autophagy of IκB Kinase
2015
Background & Aims: Plasma levels of high-density lipoprotein (HDL) cholesterol are frequently found decreased in patients with inflammatory bowel disease (IBD). Therefore, and because HDL exerts anti-inflammatory activities, we investigated whether HDL and its major protein component apolipoprotein A-I (apoA-I) modulate mucosal inflammatory responses in vitro and in vivo. Methods: The human intestinal epithelial cell line T84 was used as the in vitro model for measuring the effects of HDL on the expression and secretion of tumor necrosis factor (TNF), interleukin-8 (IL-8), and intracellular adhesion molecule (ICAM). Nuclear factor-κB (NF-κB)-responsive promoter activity was studied by …
Efficient Hot Electron Transfer in Quantum Dot-Sensitized Mesoporous Oxides at Room Temperature
2018
Hot carrier cooling processes represent one of the major efficiency losses in solar energy conversion. Losses associated with cooling can in principle be circumvented if hot carrier extraction toward selective contacts is faster than hot carrier cooling in the absorber (in so-called hot carrier solar cells). Previous work has demonstrated the possibility of hot electron extraction in quantum dot (QD)-sensitized systems, in particular, at low temperatures. Here we demonstrate a room-temperature hot electron transfer (HET) with up to unity quantum efficiency in strongly coupled PbS quantum dot-sensitized mesoporous SnO2. We show that the HET efficiency is determined by a kinetic competition b…
Baltā āboliņa Trifolium repens L. populācijas ģenētiskās daudzveidības noteikšana
2015
Baltais āboliņš (Trifolium repens L.) ir plaši pārstāvēts gan pilsētvidē, gan ārpus tās. Darba mērķis bija noteikt baltā āboliņa Latvijas populācijas ģenētisko daudzveidību, izmantojot iPBS (inter primer binding sites) uz retrotranspazoniem balstītu metodi, un ploiditāti, izmantojot plūsmas citometrijas metodi. Iegūtie rezultāti salīdzināti starp 3 augu paraugkopām – urbānā vide (Rīgas pilsētas teritorija), dabiskā vide (Latvijas novadu teritorijas) un selekcionētais materiāls giganteum šķirne „Daile”. Darbā analizēti 86 baltā āboliņa DNS paraugi. iPBS metodē izmantoti divi specifiski praimeri 2076 un 2079. PCR produkti analizēti 1,7% agarozes gelā. Konstatēti 107 lokusi, iegūtie rezultāti …