2,474 research outputs found
Anharmonic force fields of perchloric acid, HClO, and perchloric anhydride, ClO. An extreme case of inner polarization
DFT (density functional theory) anharmonic force fields with basis sets near
the Kohn-Sham limit have been obtained for perchloric acid, HClO, and
perchloric anhydride, ClO. Calculated fundamental frequencies are in
very good agreement with available experimental data. Some reassignments in the
vibrational spectra of ClO are proposed based on our calculations.
HClO and ClO are particularly severe examples of the `inner
polarization' phenomenon. The polarization consistent basis sets pc-1 and pc-2
(as well as their augmented counterparts) should be supplemented with two
(preferably three) and one (preferably two) high-exponent functions,
respectively, on second-row atoms. Complete anharmonic force fields are
available as electronic supporting information.Comment: J. Mol. Struct., in press (special issue); Electronic Supporting
Information at http://theochem.weizmann.ac.il/web/papers/Cl2O7.htm
Reconciling the interests of the economic diversification participants in a single-industry town
Рассматриваются проблемы согласования интересов участников процесса диверсификации экономики моногорода в процессе управления развитием моногорода на основе реализации стратегии диверсификации. Целью исследования является разработка инструментов гармонизации интересов участников процесса диверсификации экономики моногорода на основе разработки модели полного согласования интересов и сопоставления ее с моделью отдельно взятого моногорода. Методы исследования: системный подход, анализ и синтез, построение множеств согласования интересов с применением диаграммы Эйлера-Венна, методы комбинаторики, построение экономических показателей и рядов динамики, графический метод представления результатов и построения иерархии согласования интересов. Результаты исследования. Представлена модель полного согласования интересов различных групп лиц, в которой отражены сферы возможного пересечения интересов, а также иерархия числа согласуемых интересов. Предложены основные группы участников процесса диверсификации моногорода, а также разграничено понятие участника и роли (функции) участника в данном процессе. Обосновано и определено число множеств в зависимости от числа участников, чьи интересы одновременно согласуются, на примере моногорода Калтан Кемеровской области. На основе предложенной модели построена модель согласования интересов на примере моногорода Калтана. Полученная модель имеет трапециевидную форму, что свидетельствует о достаточно небольшом числе общих согласуемых интересов. Автор приходит к выводу, что в моногороде сформирован треугольник интересов «администрация города - малый бизнес в роли инвестора - вуз», представляющий основу в иерархии согласования интересов моногорода Калтан. Центральное положение при согласовании интересов с прочими участниками занимает исключительно администрация города. На основе данных выводов внесены предложения по направлениям дальнейшего согласования интересов на примере рассматриваемого моногорода.The article explores the problems of reconciling the interests of single-industry towns, a need that arises from the entire process of industry development management through a diversification strategy. The aim of this study is to develop tools to harmonize the interests of the single-industry towns, based on a model of full harmonization with the model of an individual single-industry town. Methods of the research: system approach, analysis and synthesis, building a set of harmonized interests with the application of the Eulerian-Venn diagram, combinatorics methods, construction of economic indicators and series of dynamics, graphical method of presentation of results and building the hierarchy of interests. Results of the study. The paper introduces the model for fully reconciling the interests of different groups of persons, reflecting the areas of possible intersecting interests and the hierarchy of the number of interests involved. The article proposes the main groups of participants in the diversification process and the differentially concept of participant and the role (function) of the participant in the diversification process. The author justifies and estimates the number of sets depending on the number of participants whose interests are concurrently reconciled in Kaltan case study. The proposed model is used for Kaltan, Kemerovo region case study. The result ing model is of a trapezoidal form, which indicates that there are quite a few common consenting interests. The author concludes that a triangle of interests «city administration - small business as investor - university» is formed. This triangle represents the highest level of harmonization of interests in the hierarchy. The city administration is in central position in reconciling interests with other participants. By the example of the considered single-industry town and based on these findings the suggestion on further harmonization of interests was made
Исследование влияние состава и процессов нагрева на эффективность люминесценции люминофоров на основе алюмоиттриевого граната
New vibrational assignments for the nu1 to nu17 vibrational modes of aziridine and first analysis of the high resolution infrared spectrum of aziridine between 720 cm-1 and 1050 cm-1
International audienceFourier transform spectra of aziridine (C2H4NH) were recorded at high resolution (0.002 or 0.003 cm-1) in the 600-1750 and 1750-4000 cm-1 regions, using a Bruker IFS125HR spectrometer, located at the LISA facility in Creteil. In parallel, the harmonic force field of aziridine was evaluated analytically at the optimized geometry with second-order Møller-Plesset perturbation theory (MP2) together with the correlation-consistent polarized valence triple zeta basis sets cc-pVTZ. These ab initio predictions were used to perform consistent vibrational assignments for the nu1 to nu17 fundamental bands of aziridine observed in the infrared spectra recorded during this study. Finally, a first detailed rotational assignment was performed for two B-type bands located at 772.3571 cm-1 (nu10, CH2 rock) and 997.1592 cm-1 (nu8, NH bend) and for an A-type band located at 904.0429 cm-1 nu17 , ring deform). We noticed that the nu10 band is weakly perturbed, presumably because the v10 = 1 rotational levels are coupled with those of the v18 = 1 dark band located around 817 cm-1 through B-type and C-type Coriolis resonances
Lyophilisation of influenza, rabies and Marburg lentiviral pseudotype viruses for the development and distribution of a neutralisation-assay based diagnostic kit
Pseudotype viruses (PVs) are chimeric, replication-deficient virions that mimic wild-type virus entry mechanisms and can be safely employed in neutralisation assays, bypassing the need for high biosafety requirements and performing comparably to established serological assays. However, PV supernatant necessitates -80°C long-term storage and cold-chain maintenance during transport, which limits the scope of dissemination and application throughout resource-limited laboratories. We therefore investigated the effects of lyophilisation on influenza, rabies and Marburg PV stability, with a view to developing a pseudotype virus neutralisation assay (PVNA) based kit suitable for affordable global distribution. Infectivity of each PV was calculated after lyophilisation and immediate reconstitution, as well as subsequent to incubation of freeze-dried pellets at varying temperatures, humidities and timepoints. Integrity of glycoprotein structure following treatment was also assessed by employing lyophilised PVs in downstream PVNAs. In the presence of 0.5M sucrose-PBS cryoprotectant, each freeze-dried pseudotype was stably stored for 4 weeks at up to 37°C and could be neutralised to the same potency as unlyophilised PVs when employed in PVNAs. These results confirm the viability of a freeze-dried PVNA-based kit, which could significantly facilitate low-cost serology for a wide portfolio of emerging infectious viruses
Seawater redox variations during the deposition of the Kimmeridge Clay Formation, United Kingdom (Upper Jurassic): evidence from molybdenum isotopes and trace metal ratios
The Kimmeridge Clay Formation (KCF) and its equivalents worldwide represent one of the most prolonged periods of organic carbon accumulation of the Mesozoic. In this study, we use the molybdenum (Mo) stable isotope system in conjunction with a range of trace metal paleoredox proxies to assess how seawater redox varied both locally and globally during the deposition of the KCF. Facies with lower organic carbon contents (TOC 1–7 wt %) were deposited under mildly reducing (suboxic) conditions, while organic-rich facies (TOC >7 wt %) accumulated under more strongly reducing (anoxic or euxinic) local conditions. Trace metal abundances are closely linked to TOC content, suggesting that the intensity of reducing conditions varied repeatedly during the deposition of the KCF and may have been related to orbitally controlled climate changes. Long-term variations in ?98/95Mo are associated with the formation of organic-rich intervals and are related to third-order fluctuations in relative sea level. Differences in the mean ?98/95Mo composition of the organic-rich intervals suggest that the global distribution of reducing conditions was more extensive during the deposition of the Pectinatites wheatleyensis and lower Pectinatites hudlestoni zones than during the deposition of the upper Pectinatites hudlestoni and Pectinatites pectinatus zones. The global extent of reducing conditions during the Kimmerigidan was greater than today but was less widespread than during the Toarcian (Early Jurassic) oceanic anoxic event. This study also demonstrates that the Mo isotope system in Jurassic seawater responded to changes in redox conditions in a manner consistent with its behavior in present-day sedimentary environment
Rotational spectra of isotopic species of methyl cyanide, CHCN, in their ground vibrational states up to terahertz frequencies
Methyl cyanide is an important trace molecule in star-forming regions. It is
one of the more common molecules used to derive kinetic temperatures in such
sources. As preparatory work for Herschel, SOFIA, and in particular ALMA we
want to improve the rest frequencies of the main as well as minor isotopologs
of methyl cyanide. The laboratory rotational spectrum of methyl cyanide in
natural isotopic composition has been recorded up to 1.63 THz. Transitions with
good signal-to-noise ratio could be identified for CHCN, CHCN,
CHCN, CHCN, CHDCN, and CHCN in their
ground vibrational states up to about 1.2 THz. The main isotopic species could
be identified even in the highest frequency spectral recordings around 1.6 THz.
The highest quantum numbers included in the fit are 64 for
CHCN and 89 for the main isotopic species. Greatly improved
spectroscopic parameters have been obtained by fitting the present data
together with previously reported transition frequencies. The present data will
be helpful to identify isotopologs of methyl cyanide in the higher frequency
bands of instruments such as the recently launched Herschel satellite, the
upcoming airplane mission SOFIA or the radio telescope array ALMA.Comment: 13 pages, 2 figures, article appeared; CDMS links update
CD20 and CD19 targeted vectors induce minimal activation of resting B lymphocytes
B lymphocytes are an important cell population of the immune system. However, until recently it was not possible to transduce resting B lymphocytes with retro- or lentiviral vectors, making them unsusceptible for genetic manipulations by these vectors. Lately, we demonstrated that lentiviral vectors pseudotyped with modified measles virus (MV) glycoproteins hemagglutinin, responsible for receptor recognition, and fusion protein were able to overcome this transduction block. They use either the natural MV receptors, CD46 and signaling lymphocyte activation molecule (SLAM), for cell entry (MV-LV) or the vector particles were further modified to selectively enter via the CD20 molecule, which is exclusively expressed on B lymphocytes (CD20-LV). It has been shown previously that transduction by MV-LV does not induce B lymphocyte activation. However, if this is also true for CD20-LV is still unknown. Here, we generated a vector specific for another B lymphocyte marker, CD19, and compared its ability to transduce resting B lymphocytes with CD20-LV. The vector (CD19ds-LV) was able to stably transduce unstimulated B lymphocytes, albeit with a reduced efficiency of about 10% compared to CD20-LV, which transduced about 30% of the cells. Since CD20 as well as CD19 are closely linked to the B lymphocyte activation pathway, we investigated if engagement of CD20 or CD19 molecules by the vector particles induces activating stimuli in resting B lymphocytes. Although, activation of B lymphocytes often involves calcium influx, we did not detect elevated calcium levels. However, the activation marker CD71 was substantially up-regulated upon CD20-LV transduction and most importantly, B lymphocytes transduced with CD20-LV or CD19ds-LV entered the G1b phase of cell cycle, whereas untransduced or MV-LV transduced B lymphocytes remained in G0. Hence, CD20 and CD19 targeting vectors induce activating stimuli in resting B lymphocytes, which most likely renders them susceptible for lentiviral vector transduction
Assessment of Various Density Functionals and Basis Sets for the Calculation of Molecular Anharmonic Force Fields
In a previous contribution (Mol. Phys. {\bf 103}, xxxx, 2005), we established
the suitability of density functional theory (DFT) for the calculation of
molecular anharmonic force fields. In the present work, we have assessed a wide
variety of basis sets and exchange-correlation functionals for harmonic and
fundamental frequencies, equilibrium and ground-state rotational constants, and
thermodynamic functions beyond the RRHO (rigid rotor-harmonic oscillator)
approximation. The fairly good performance of double-zeta plus polarization
basis sets for frequencies results from an error compensation between basis set
incompleteness and the intrinsic error of exchange-correlation functionals.
Triple-zeta plus polarization basis sets are recommended, with an additional
high-exponent function on second-row atoms. All conventional hybrid GGA
functionals perform about equally well: high-exchange hybrid GGA and meta-GGA
functionals designed for kinetics yield poor results, with the exception of of
the very recently developed BMK functional which takes a middle position along
with the HCTH/407 (second generation GGA) and TPSS (meta-GGA) functionals. MP2
performs similarly to these functionals but is inferior to hybrid GGAs such as
B3LYP and B97-1.Comment: Int. J. Quantum Chem., in press (special issue on vibrational
spectroscopies
Isoform-specific potentiation of stem and progenitor cell engraftment by AML1/RUNX1
Background: AML1/RUNX1 is the most frequently mutated gene in leukaemia and is central to the normal biology of hematopoietic stem and progenitor cells. However, the role of different AML1 isoforms within these primitive compartments is unclear. Here we investigate whether altering relative expression of AML1 isoforms impacts the balance between cell self-renewal and differentiation in vitro and in vivo. Methods and Findings: The human AML1a isoform encodes a truncated molecule with DNA-binding but no transactivation capacity. We used a retrovirus-based approach to transduce AML1a into primitive haematopoietic cells isolated from the mouse. We observed that enforced AML1a expression increased the competitive engraftment potential of murine long-term reconstituting stem cells with the proportion of AML1a-expressing cells increasing over time in both primary and secondary recipients. Furthermore, AML1a expression dramatically increased primitive and committed progenitor activity in engrafted animals as assessed by long-term culture, cobblestone formation, and colony assays. In contrast, expression of the full-length isoform AML1b abrogated engraftment potential. In vitro, AML1b promoted differentiation while AML1a promoted proliferation of progenitors capable of short-term lymphomyeloid engraftment. Consistent with these findings, the relative abundance of AML1a was highest in the primitive stem/progenitor compartment of human cord blood, and forced expression of AML1a in these cells enhanced maintenance of primitive potential both in vitro and in vivo. Conclusions: These data demonstrate that the "a" isoform of AML1 has the capacity to potentiate stem and progenitor cell engraftment, both of which are required for successful clinical transplantation. This activity is consistent with its expression pattern in both normal and leukaemic cells. Manipulating the balance of AML1 isoform expression may offer novel therapeutic strategies, exploitable in the contexts of leukaemia and also in cord blood transplantation in adults, in whom stem and progenitor cell numbers are often limiting. © 2007 Tsuzuki et al
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