Structural and vibrational properties of α- and π-SnS polymorphs for photovoltaic applications

Tin sulphide (SnS) has attracted the attention of the photovoltaic (PV) community due to the combination of desirable optical properties, and its binary and earth abundant elemental composition, which should lead to relatively simple synthesis. However, currently the best SnS based PV device efficiency remains at 4.36%. Limited performance of this material is attributed to band gap alignment issues, deviations in doping concentration and poor film morphology. In this context Raman spectroscopy (RS) analysis can be useful as it facilitates the accurate evaluation of material properties. In this study we present a RS study, supported by X-ray diffraction and wavelength dispersive X-ray measurements, of α- and π-SnS thin films. In particular a complete description of SnS vibrational properties is made using six excitation wavelengths, including excitation energies coupled with certain optical band to band transitions, which leads to close to resonance measurement conditions. This study describes an in-depth analysis of the Raman spectra of both SnS structural polymorphs, including the differences in the number of observed peaks, with their relative intensities and Raman shift. Additionally, we evaluate the impact of low temperature heat treatment on SnS. These results explicitly present how the variation of the [S]/[Sn] ratio in samples deposited by different methods can lead to significant and correlated shifts in the relative positions of Raman peaks, which is only observed in the α-SnS phase. Furthermore, we discuss the suitability of using Raman spectroscopy based methodologies to extract fine stoichiometric variations in different α-SnS samples.</p

Characterization of the Biosynthesis, Processing and Kinetic Mechanism of Action of the Enzyme Deficient in Mucopolysaccharidosis IIIC

Heparin acetyl-CoA:alpha-glucosaminide N-acetyltransferase (N-acetyltransferase, EC 2.3.1.78) is an integral lysosomal membrane protein containing 11 transmembrane domains, encoded by the HGSNAT gene. Deficiencies of N-acetyltransferase lead to mucopolysaccharidosis IIIC. We demonstrate that contrary to a previous report, the N-acetyltransferase signal peptide is co-translationally cleaved and that this event is required for its intracellular transport to the lysosome. While we confirm that the N-acetyltransferase precursor polypeptide is processed in the lysosome into a small amino-terminal alpha- and a larger ß- chain, we further characterize this event by identifying the mature amino-terminus of each chain. We also demonstrate this processing step(s) is not, as previously reported, needed to produce a functional transferase, i.e., the precursor is active. We next optimize the biochemical assay procedure so that it remains linear as N-acetyltransferase is purified or protein-extracts containing N-acetyltransferase are diluted, by the inclusion of negatively charged lipids. We then use this assay to demonstrate that the purified single N-acetyltransferase protein is both necessary and sufficient to express transferase activity, and that N-acetyltransferase functions as a monomer. Finally, the kinetic mechanism of action of purified N-acetyltransferase was evaluated and found to be a random sequential mechanism involving the formation of a ternary complex with its two substrates; i.e., N-acetyltransferase does not operate through a ping-pong mechanism as previously reported. We confirm this conclusion by demonstrating experimentally that no acetylated enzyme intermediate is formed during the reaction

CNS Penetration of Intrathecal-Lumbar Idursulfase in the Monkey, Dog and Mouse: Implications for Neurological Outcomes of Lysosomal Storage Disorder

A major challenge for the treatment of many central nervous system (CNS) disorders is the lack of convenient and effective methods for delivering biological agents to the brain. Mucopolysaccharidosis II (Hunter syndrome) is a rare inherited lysosomal storage disorder resulting from a deficiency of iduronate-2-sulfatase (I2S). I2S is a large, highly glycosylated enzyme. Intravenous administration is not likely to be an effective therapy for disease-related neurological outcomes that require enzyme access to the brain cells, in particular neurons and oligodendrocytes. We demonstrate that intracerebroventricular and lumbar intrathecal administration of recombinant I2S in dogs and nonhuman primates resulted in widespread enzyme distribution in the brain parenchyma, including remarkable deposition in the lysosomes of both neurons and oligodendrocytes. Lumbar intrathecal administration also resulted in enzyme delivery to the spinal cord, whereas little enzyme was detected there after intraventricular administration. Mucopolysaccharidosis II model is available in mice. Lumbar administration of recombinant I2S to enzyme deficient animals reduced the storage of glycosaminoglycans in both superficial and deep brain tissues, with concurrent morphological improvements. The observed patterns of enzyme transport from cerebrospinal fluid to the CNS tissues and the resultant biological activity (a) warrant further investigation of intrathecal delivery of I2S via lumbar catheter as an experimental treatment for the neurological symptoms of Hunter syndrome and (b) may have broader implications for CNS treatment with biopharmaceuticals

Прогнозування показників проектів у часі з використанням механізмів когнітивного моделювання

Fundamental methodological approach to the problem of predicting the parameters of the project within time in terms of factors analytical relationships absence and limited information was proposed.Предложен принципиальный методологический подход к решению задачи прогнозирования параметров проекта во времени в условиях отсутствия аналитических зависимостей между факторами и ограниченности информации.Запропоновано принциповий методологічний підхід до розв’язання задачі прогнозування параметрів проекту в часі в умовах  відсутності аналітичних залежностей між факторами та обмеженості інформації

Стан та перспективи розвитку методології управління програмами інноваційного розвитку

Results of the analysis and knowledge organization in the field of innovative development programs have been shown. Directions of possible development of a methodology for performance of long-term strategies for management systems creation have been determined.Приведены результаты анализа и структуризации знаний в области управления программами инновационного развития. Определены направления возможного развития методологии для выработки долгосрочных стратегий построения систем управления.Наведено результати аналізу та структуризації знань у галузі управління програмами інноваційного розвитку. Визначено напрямки можливого розвитку методології для вироблення довгострокових стратегій побудови систем управління

A new simple enzyme assay for pre- and postnatal diagnosis of infantile neuronal ceroid lipofuscinosis (INCL) and its variants

Palmitoyl-protein thioesterase (PPT) deficiency was recently shown to be the primary defect in infantile neuronal ceroid lipofuscinosis (INCL). The available enzyme assay is complicated and impractical for diagnostic use and is, in practice, unavailable. We have developed a new fluorimetric assay for PPT based on the sensitive fluorochrome 4-methylumbelliferone. This PPT assay is simple, sensitive, and robust and will facilitate the definition of the full clinical spectrum associated with a deficiency of PPT. PPT activity was readily detectable in fibroblasts, leucocytes, lymphoblasts, amniotic fluid cells, and chorionic villi, but was profoundly deficient in these tissues from INCL patients. Similarly, a deficiency of PPT was shown in patients with the variant juvenile NCL with GROD. These results show that rapid pre- and postnatal diagnosis can be performed with this new enzyme assay for PPT.


Keywords: infantile neuronal ceroid lipofuscinosis; CLN1; palmitoyl-protein thioesterase; enzyme analysi