93 research outputs found
Magnetic Transformations in the Organic Conductor kappa-(BETS)2Mn[N(CN)2]3 at the Metal-Insulator Transition
A complex study of magnetic properties including dc magnetization, 1H NMR and
magnetic torque measurements has been performed for the organic conductor
kappa-(BETS)2Mn[N(CN)2]3 which undergoes a metal-insulator transition at
T_MI~25K. NMR and the magnetization data indicate a transition in the manganese
subsystem from paramagnetic to a frozen state at T_MI, which is, however, not a
simple Neel type order. Further, a magnetic field induced transition resembling
a spin flop has been detected in the torque measurements at temperatures below
T_MI. This transition is most likely related to the spins of pi-electrons
localized on the organic molecules BETS and coupled with the manganese 3d spins
via exchange interaction.Comment: 6 pages, 5 Figures, 1 Table; Submitted to Phys.Rev.B (Nov.2010
Indication for the coexistence of closed orbit and quantum interferometer with the same cross section in the organic metal (ET)4(H3O)[Fe(C2O4)3].C6H4Cl2: Persistence of SdH oscillations above 30 K
Shubnikov-de Haas (SdH) and de Haas-van Alphen (dHvA) oscillations spectra of
the quasi-two dimensional charge transfer salt
"-(ET)(HO)[Fe(CO)]CHCl have been
investigated in pulsed magnetic fields up to 54 T. The data reveal three basic
frequencies F, F and F, which can be interpreted on the basis
of three compensated closed orbits at low temperature. However a very weak
thermal damping of the Fourier component F, with the highest amplitude, is
evidenced for SdH spectra above about 6 K. As a result, magnetoresistance
oscillations are observed at temperatures higher than 30 K. This feature, which
is not observed for dHvA oscillations, is in line with quantum interference,
pointing to a Fermi surface reconstruction in this compound.Comment: published in Eur. Phys. J. B 71 203 (2009
Monocationic chlorin – new promising photosensitizer for antitumor and antimicrobial photodynamic therapy
В статье описан новый перспективный монокатионный фотосенсибилизатор для противоопухолевой и антимикробной терапии на основе природного хлорофилла. Этот новый фотосенсибилизирующий агент (McChl) получают из метилфеофорбида по двухстадийной методике
Morphology and variability of the facial nerve trunk dependent on branching pattern, gender, anthropometric type and side of the head in Moldovan population
Background: Knowledge concerning variability of the facial nerve trunk (FNT) direction after its exit through the stylomastoid foramen is of a great clinical significance for maxillofacial surgeons, otorhinolaryngologists, oncologists, specialists in plastic and aesthetic surgery. The aim of our study was to establish the variation of the FNT direction and its peculiarities dependent on branching pattern, gender, anthropometric type and side of the head.
Materials and methods: The direction of the FNT and its branching pattern were studied on 75 dissected hemifaces of adult formalized cadavers (59 male/16 female), and the morphometry of the FNT length, width and bifurcation angle was carried out.
Results: Seven branching patterns of the facial nerve were established: Type I – 18.7%, Type II – 14.7%, Type III – 20%, Type IV – 14.6%, Type V – 5.3%, Type VI – 18.7%, and Type-NI – 8% (bizarre types). The FNT had a descending direction in 73.3% of cases; ascending FNT – 9.3% (including 5.3% of very short diffuse branching trunks and 1.3% of arch-shaped FNT); horizontal FNT – 10.7%; number variants – 6.7%. The male/female ratio of the descending FNT was 69.5%/87.4%; ascending – 10.2%/6.3%; horizontal – 11.9%/6.3%; number variants – 8.4% (only in male). The right/left ratio of the descending FNT was 62.9%/82.5%; ascending – 11.4%/7.5%; horizontal – 11.4%/10%; number variants – 14.3% (only on the right side). The ratio of the descending FNT in mesocephalic type (MCT) / brachycephalic type (BCT) / dolichocephalic type (DCT) was respectively 70.6%/100%/66.7%; ascending – 12.1%/0%/0%; horizontal – 12.1/0%/11.1%. Numerical variants in MCT – 5.2%, in DCT – 22.2%. The mean number of FNT in MCT/BCT/DCT was respectively 1.07/1.0/1.22.
Conclusions: Three main directions are characteristic for FNT: the descending, ascending and horizontal ones, which vary dependent on branching pattern, gender, shape and side of the head
Crystalline Arrays of Pairs of Molecular Rotors: Correlated Motion, Rotational Barriers, and Space-Inversion Symmetry Breaking Due to Conformational Mutations
The rod-like molecule bis 4-(4-pyridyl)ethynyl)bicyclo[2.2.2]oct-1-yl)buta-1,3-diyne, 1, contains two 1,4-bis(ethynyl)bicyclo[2.2.2]octane (ethynyl) chiral rotators linked by a diyne fragment and self assembles in a one-dimensional, monoclinic C2/c centrosymmetric structure where two equilibrium positions with large occupancy imbalance (88% versus 12%) are identified on a single rotor site Combining variable temperature (70-300 K) proton spin-lattice relaxation, H-1 T-1(-1), at two different H-1 Larmor frequencies (55 and 210 MHz) and DFT calculations of rotational barriers, we were able to assign two types of Brownian rotators with different activation energies, 1.85 and 6.1 kcal mol(-1), to the two H-1 spin-lattice relaxation processes on the single rotor site. On the basis of DFT calculations, the low-energy process has been assigned to adjacent rotors in a well-correlated synchronous motion, whereas the high-energy process is the manifestation of an abrupt change in their kinematics once two blades of adjacent rotors are seen to rub together. Although crystals of 1 should be second harmonic inactive, a large second-order optical response is recorded when the electric field oscillates in a direction parallel to the unique rotor axle director. We conclude that conformational mutations by torsional interconversion of the three blades of the BCO units break space-inversion symmetry in sequences of mutamers in dynamic equilibrium in the crystal in domains at a rnesoscopic scale comparable with the wavelength of light used A control experiment was performed with a crystalline film of a similar tetrayne molecule, 1,4-bis(3-((trimethylsilyl)ethynyl)bicyclo-[1.1.1]pent-1-yObuta-1,3-diyne, whose bic-ydopentane units can rotate but are achiral and produce no second-order optical response
Mitochondrial Localized STAT3 Is Involved in NGF Induced Neurite Outgrowth
Background: Signal transducer and activator of transcription 3 (STAT3) plays critical roles in neural development and is increasingly recognized as a major mediator of injury response in the nervous system. Cytokines and growth factors are known to phosphorylate STAT3 at tyrosine 705 with or without the concomitant phosphorylation at serine 727, resulting in the nuclear localization of STAT3 and subsequent transcriptional activation of genes. Recent evidence suggests that STAT3 may control cell function via alternative mechanisms independent of its transcriptional activity. Currently, the involvement of STAT3 mono-phosphorylated at residue serine 727 (P-Ser-STAT3) in neurite outgrowth and the underlying mechanism is largely unknown. Principal Findings: In this study, we investigated the role of nerve growth factor (NGF) induced P-Ser-STAT3 in mediating neurite outgrowth. NGF induced the phosphorylation of residue serine 727 but not tyrosine 705 of STAT3 in PC12 and primary cortical neuronal cells. In PC12 cells, serine but not tyrosine dominant negative mutant of STAT3 was found to impair NGF induced neurite outgrowth. Unexpectedly, NGF induced P-Ser-STAT3 was localized to the mitochondria but not in the nucleus. Mitochondrial STAT3 was further found to be intimately involved in NGF induced neurite outgrowth and the production of reactive oxygen species (ROS). Conclusion: Taken together, the findings herein demonstrated a hitherto unrecognized novel transcription independen
Personality profiles and the "russian soul": Literary and scholarly views evaluated
Many domestic and foreign observers have claimed that Russians have a unique constellation of personality traits that mirrors their distinctive historical and cultural experience. To examine the hypothesized uniqueness of Russian personality, members of the Russian Character and Personality Survey collected data from 39 samples in 33 administrative areas of the Russian Federation. Respondents (N = 7,065) identified an ethnically Russian adult or college-aged man or woman whom they knew well and rated the target using the Russian observer-rating version of the Revised NEO Personality Inventory. The mean personality profile of Russians was very similar to the international average based on 50 different countries, debunking the myth of a unique Russian soul.The small variations from world norms did not converge with depictions of Russian national character in fiction and the scholarly literature. New items intended to capture distinctive, emic aspects of Russian personality provided no new information beyond the familiar Big Five dimensions. Religion, ethnicity, and beliefs about the uniqueness of the Russian character and the malleability of personality traits had little effect on personality ratings. Perceptions of the Russian soul do not seem to be based on the personality traits of Russians
Treatment for Mild Chronic Hypertension during Pregnancy.
BACKGROUND: The benefits and safety of the treatment of mild chronic hypertension (blood pressure, \u3c160/100 mm Hg) during pregnancy are uncertain. Data are needed on whether a strategy of targeting a blood pressure of less than 140/90 mm Hg reduces the incidence of adverse pregnancy outcomes without compromising fetal growth.
METHODS: In this open-label, multicenter, randomized trial, we assigned pregnant women with mild chronic hypertension and singleton fetuses at a gestational age of less than 23 weeks to receive antihypertensive medications recommended for use in pregnancy (active-treatment group) or to receive no such treatment unless severe hypertension (systolic pressure, ≥160 mm Hg; or diastolic pressure, ≥105 mm Hg) developed (control group). The primary outcome was a composite of preeclampsia with severe features, medically indicated preterm birth at less than 35 weeks\u27 gestation, placental abruption, or fetal or neonatal death. The safety outcome was small-for-gestational-age birth weight below the 10th percentile for gestational age. Secondary outcomes included composites of serious neonatal or maternal complications, preeclampsia, and preterm birth.
RESULTS: A total of 2408 women were enrolled in the trial. The incidence of a primary-outcome event was lower in the active-treatment group than in the control group (30.2% vs. 37.0%), for an adjusted risk ratio of 0.82 (95% confidence interval [CI], 0.74 to 0.92; P
CONCLUSIONS: In pregnant women with mild chronic hypertension, a strategy of targeting a blood pressure of less than 140/90 mm Hg was associated with better pregnancy outcomes than a strategy of reserving treatment only for severe hypertension, with no increase in the risk of small-for-gestational-age birth weight. (Funded by the National Heart, Lung, and Blood Institute; CHAP ClinicalTrials.gov number, NCT02299414.)
From Vulnerable Plaque to Vulnerable Patient
Atherosclerotic cardiovascular disease results in >19 million deaths annually, and coronary heart disease accounts for the majority of this toll. Despite major advances in treatment of coronary heart disease patients, a large number of victims of the disease who are apparently healthy die suddenly without prior symptoms. Available screening and diagnostic methods are insufficient to identify the victims before the event occurs. The recognition of the role of the vulnerable plaque has opened new avenues of opportunity in the field of cardiovascular medicine. This consensus document concludes the following. (1) Rupture-prone plaques are not the only vulnerable plaques. All types of atherosclerotic plaques with high likelihood of thrombotic complications and rapid progression should be considered as vulnerable plaques. We propose a classification for clinical as well as pathological evaluation of vulnerable plaques. (2) Vulnerable plaques are not the only culprit factors for the development of acute coronary syndromes, myocardial infarction, and sudden cardiac death. Vulnerable blood (prone to thrombosis) and vulnerable myocardium (prone to fatal arrhythmia) play an important role in the outcome. Therefore, the term "vulnerable patient" may be more appropriate and is proposed now for the identification of subjects with high likelihood of developing cardiac events in the near future. (3) A quantitative method for cumulative risk assessment of vulnerable patients needs to be developed that may include variables based on plaque, blood, and myocardial vulnerability. In Part I of this consensus document, we cover the new definition of vulnerable plaque and its relationship with vulnerable patients. Part II of this consensus document will focus on vulnerable blood and vulnerable myocardium and provide an outline of overall risk assessment of vulnerable patients. Parts I and II are meant to provide a general consensus and overviews the new field of vulnerable patient. Recently developed assays (eg, C-reactive protein), imaging techniques (eg, CT and MRI), noninvasive electrophysiological tests (for vulnerable myocardium), and emerging catheters (to localize and characterize vulnerable plaque) in combination with future genomic and proteomic techniques will guide us in the search for vulnerable patients. It will also lead to the development and deployment of new therapies and ultimately to reduce the incidence of acute coronary syndromes and sudden cardiac death. We encourage healthcare policy makers to promote translational research for screening and treatment of vulnerable patients
Vascular contributions to cognitive impairment and dementia including Alzheimer's disease
AbstractScientific evidence continues to demonstrate the linkage of vascular contributions to cognitive impairment and dementia such as Alzheimer's disease. In December, 2013, the Alzheimer's Association, with scientific input from the National Institute of Neurological Disorders and Stroke and the National Heart, Lung and Blood Institute from the National Institutes of Health, convened scientific experts to discuss the research gaps in our understanding of how vascular factors contribute to Alzheimer's disease and related dementia. This manuscript summarizes the meeting and the resultant discussion, including an outline of next steps needed to move this area of research forward
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