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1.
Phys Rev Lett ; 132(23): 231903, 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38905689

ABSTRACT

The cross section of the process e^{+}e^{-}→π^{+}π^{-} has been measured in the center-of-mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The measurement is based on an integrated luminosity of about 88 pb^{-1}, of which 62 pb^{-1} represent a complete dataset collected by CMD-3 at center-of-mass energies below 1 GeV. In the dominant region near the ρ resonance a systematic uncertainty of 0.7% was achieved. The implications of the presented results for the evaluation of the hadronic contribution to the anomalous magnetic moment of the muon are discussed.

3.
Sci Rep ; 13(1): 22437, 2023 Dec 17.
Article in English | MEDLINE | ID: mdl-38105270

ABSTRACT

We present new mineralogical data of cronstedtite from the Southern-2 orebody, located in the South-Western branch of the Talnakh intrusion (Noril'sk area) composed of massive sulfides in which the total amount of oxides and silicates does not exceed 1-3 vol%. The petrographic and mineralogical features of these ores indicated occurrence of fine-grained, fibrous needle like clusters < 50-µm-sized grains of cronstedtite (7.09 Å along its c-axis). This mineral confirmed by a number of analytical techniques (powder X-ray diffraction of balk samples, transmission electron microscopy, scanning electron microscopy, Raman and Infrared spectroscopy). Cronstedtite sporadically contains signals of Al, Ni, Ca and filling the cracks and cavities between sulfides of copper (chalcopyrite) and iron (pyrrhotite, pentlandite). In some cases, cronstedtite contains micron-sized PGM, and associates with magnetite. According the X-ray diffraction analysis of the bulk massive ores besides cronstendtite are established kaolinite, gypsum, calcite, quartz, and cristobalite. The findings of cronstedtite in Noril'sk area have never been mentioned publicly before. Its occurrence is the northernmost known locality in the world. Our results imply that the formation of cronstedtite in the Talnakh intrusion could be possible by the active participation low-temperatures fluids within the relatively near-surface (< 2 km of paleosurface) conditions of intrusion emplacement, in contrast to other deep-seated supergiant Cu-Ni-PGE deposits in the world. The conditions of formation in isolated cavities in fresh pyrrhotite-pentlandite-chalcopyrite massive ores of deep level of the Talnakh intrusion could be favorable for the formation of cronstendtite.

4.
Indian J Med Res ; 158(4): 351-362, 2023 Oct 01.
Article in English | MEDLINE | ID: mdl-37988028

ABSTRACT

BACKGROUND OBJECTIVES: In view of anecdotal reports of sudden unexplained deaths in India's apparently healthy young adults, linking to coronavirus disease 2019 (COVID-19) infection or vaccination, we determined the factors associated with such deaths in individuals aged 18-45 years through a multicentric matched case-control study. METHODS: This study was conducted through participation of 47 tertiary care hospitals across India. Cases were apparently healthy individuals aged 18-45 years without any known co-morbidity, who suddenly (<24 h of hospitalization or seen apparently healthy 24 h before death) died of unexplained causes during 1 st October 2021-31 st March 2023. Four controls were included per case matched for age, gender and neighborhood. We interviewed/perused records to collect data on COVID-19 vaccination/infection and post-COVID-19 conditions, family history of sudden death, smoking, recreational drug use, alcohol frequency and binge drinking and vigorous-intensity physical activity two days before death/interviews. We developed regression models considering COVID-19 vaccination ≤42 days before outcome, any vaccine received anytime and vaccine doses to compute an adjusted matched odds ratio (aOR) with 95 per cent confidence interval (CI). RESULTS: Seven hundred twenty nine cases and 2916 controls were included in the analysis. Receipt of at least one dose of COVID-19 vaccine lowered the odds [aOR (95% CI)] for unexplained sudden death [0.58 (0.37, 0.92)], whereas past COVID-19 hospitalization [3.8 (1.36, 10.61)], family history of sudden death [2.53 (1.52, 4.21)], binge drinking 48 h before death/interview [5.29 (2.57, 10.89)], use of recreational drug/substance [2.92 (1.1, 7.71)] and performing vigorous-intensity physical activity 48 h before death/interview [3.7 (1.36, 10.05)] were positively associated. Two doses lowered the odds of unexplained sudden death [0.51 (0.28, 0.91)], whereas single dose did not. INTERPRETATION CONCLUSIONS: COVID-19 vaccination did not increase the risk of unexplained sudden death among young adults in India. Past COVID-19 hospitalization, family history of sudden death and certain lifestyle behaviors increased the likelihood of unexplained sudden death.


Subject(s)
Binge Drinking , COVID-19 , Young Adult , Humans , Case-Control Studies , COVID-19 Vaccines , Binge Drinking/complications , Death, Sudden/etiology , COVID-19/epidemiology , COVID-19/complications
6.
Dig Dis Sci ; 65(6): 1615-1631, 2020 06.
Article in English | MEDLINE | ID: mdl-32350720

ABSTRACT

Gastroparesis is characterized by delayed gastric emptying, with symptoms such as nausea, vomiting and abdominal pain, in the absence of mechanical obstruction. In most cases, it is idiopathic although diabetes mellitus is another leading cause. The physiology of gastric emptying is a complex process which is influenced by various inputs including the central nervous system, enteric nervous system and gut hormones. Developments in our understanding of gastroparesis have now demonstrated dysfunction in these systems, thus disrupting normal gastric emptying. Once mechanical obstruction is excluded, gastric scintigraphy remains the gold standard for diagnosis although wireless motility capsule and breath testing are alternative methods for diagnosis. Treatment for gastroparesis is challenging, and widely available therapies are often limited either by their poor evidence for efficacy or concerns over their long-term safety profile. Novel prokinetic agents have shown initial promise in clinical trials, and new endoscopic techniques such as gastric per-oral endoscopic myotomy are emerging. These new treatment modalities may provide an option in refractory gastroparesis with the adage of reduced morbidity compared to surgical treatments.


Subject(s)
Gastroparesis/physiopathology , Gastroparesis/therapy , Endoscopy, Gastrointestinal , Gastroparesis/diagnosis , Gastroparesis/psychology , Humans
7.
Dig Dis Sci ; 63(7): 1694-1705, 2018 07.
Article in English | MEDLINE | ID: mdl-29761253

ABSTRACT

Obesity is a global health problem which is on the rise and is strongly associated with the development of type 2 diabetes and other comorbidities. Bariatric surgery is now an established treatment for both these conditions, leading to impressive results in weight loss and glycemic control. More recently, we have seen the development of various endoscopic devices as potential alternatives or adjuncts to bariatric surgery. In this state-of-the-art review, we outline the current landscape of endoscopic treatments available for the management of both obesity and diabetes, including the clinical evidence supporting their use, efficacy, safety, and potential mechanisms of action.


Subject(s)
Bariatric Surgery/instrumentation , Endoscopy/instrumentation , Obesity/surgery , Diabetes Mellitus/surgery , Duodenum , Gastric Balloon , Humans , Stomach
8.
Genome ; 61(2): 131-143, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29216443

ABSTRACT

Aegilops columnaris is a tetraploid species originated from Ae. umbellulata (2n=2x=14, UU) and a yet unknown diploid grass species. Although Ae. columnaris possesses some agronomically valuable traits, such as heat and drought tolerance and resistance to pests, it has never been used in wheat breeding because of difficulties in producing hybrids and a lack of information on the relationships between Ae. columnaris and common wheat chromosomes. In this paper, we report the development of 57 wheat - Ae. columnaris introgressive lines covering 8 of the14 chromosomes of Aegilops. Based on substitution spectra of hybrids and the results of FISH analysis of the parental Ae. columnaris line with seven DNA probes, we have developed the genetic nomenclature of the Uc and Xc chromosomes. Genetic groups and genome affinities were established for 11 of 14 chromosomes; the classification of the remaining three chromosomes remains unsolved. Each Ae. columnaris chromosome was characterized on the basis of C-banding pattern and the distribution of seven DNA sequences. Introgression processes were shown to depend on the parental wheat genotype and the level of divergence of homoeologous chromosomes. We found that lines carrying chromosome 5Xc are resistant to leaf rust; therefore, this chromosome could possess novel resistance genes that have never been utilized in wheat breeding.


Subject(s)
Chromosomes, Plant , Poaceae/genetics , Triticum/genetics , Chromosome Banding , In Situ Hybridization, Fluorescence , Plant Breeding , Poaceae/anatomy & histology
9.
Eksp Klin Gastroenterol ; (2): 21-4, 2014.
Article in Russian | MEDLINE | ID: mdl-25518470

ABSTRACT

UNLABELLED: The aim of the present study was a comprehensive study of the features autonomic nervous system in cholelithiasis before and after cholecystectomy. MATERIALS AND METHODS: 88 patients aged 40 to 60 years. 55 patients with cholelithiasis before and after laparoscopic cholecystectomy (CE). Control group consisted of 33 patients of similar age and gender. To investigate the function of the autonomic nervous system were evaluated themes complaint history, physical examination data, and used less Tod mathematical analysis of cardiac rhythm by Baevsky RM using the author's computer-related programs "Korveg" with the definition of heart rate variability and table--Solovevoj Wayne. RESULTS AND CONCLUSIONS: The study of autonomic provision in rest and during exercise were increased sympathetic activity, exceeding those in the control group. Studies indicate a tendency to sympathicotonia patients with gall stones before and after cholecystectomy, which is enhanced adaptive compensatory mechanisms to maintain homeostasis in the body. Identify logical connections between clinical and autonomic indicators will predict flow pattern cholelithiasis before and after cholecystectomy, as well as pick individual therapy for each patient taking into account the autonomic features that can be widely used in practical medicine--not.


Subject(s)
Autonomic Nervous System Diseases , Cholecystectomy , Cholelithiasis , Sympathetic Nervous System/physiopathology , Adult , Autonomic Nervous System Diseases/complications , Autonomic Nervous System Diseases/physiopathology , Autonomic Nervous System Diseases/surgery , Cholelithiasis/complications , Cholelithiasis/physiopathology , Cholelithiasis/surgery , Female , Humans , Male , Middle Aged , Postoperative Period , Preoperative Period
10.
J Phys Condens Matter ; 26(38): 386002, 2014 Sep 24.
Article in English | MEDLINE | ID: mdl-25181285

ABSTRACT

The effect of stoichiometry on magnetocrystalline anisotropy energy (MAE) of Fe1+xPt1-x and Co1+xPt1-x (-0.5 < x < 0.5) is studied by use of first-principles method. The calculated MAEs show maxima at x = 0 for both fully L10-ordered systems. Compared with that, the MAEs of partially L10-ordered systems reduce but their composition dependences do not change, without shift of the maximum MAE to Fe/Co-rich alloy as found in experiment at room temperature. In the off-stoichiometric alloys, the misoccupied Fe/Co and Pt show large MAEs, which is explained by the enhanced in-plane hybridization between Fe/Co and Pt. The composition dependence of the atom-resolved MAE is governed by the varying number of heterogeneous ligands around the atom. The MAE(T)/MAE(0) is discussed based on spontaneous magnetization and Curie temperature, which suggests that the temperature effect may contribute to the discrepancy between calculation and experiment in the composition dependence of MAE.

11.
Philos Trans A Math Phys Eng Sci ; 372(2020)2014 Jul 28.
Article in English | MEDLINE | ID: mdl-24936016

ABSTRACT

The instability of supersonic compression ramp flow is investigated. It is assumed that the Reynolds number is large and that the governing equations are the unsteady triple-deck equations. The mean flow is first calculated by solving the steady equations for various scaled ramp angles α, and the numerical results suggest that there is no singularity for increasing ramp angles. The stability of the flow is investigated using two approaches, first by solving the linearized unsteady equations and looking for global modes proportional to e(λt). In the second approach, the linearized unsteady equations are solved numerically with various initial conditions. Whereas no globally unsteady modes could be found for the range of ramp angles studied, the numerical simulations show the formation of wavepacket type disturbances which grow and convect and reach large amplitudes. However, the numerical results show large variations with grid size even on very fine grids.

12.
Cell Death Dis ; 5: e992, 2014 Jan 09.
Article in English | MEDLINE | ID: mdl-24407245

ABSTRACT

Blood glutamate scavenging is a novel and attractive protecting strategy to reduce the excitotoxic effect of extracellular glutamate released during ischemic brain injury. Glutamate oxaloacetate transaminase 1 (GOT1) activation by means of oxaloacetate administration has been used to reduce the glutamate concentration in the blood. However, the protective effect of the administration of the recombinant GOT1 (rGOT1) enzyme has not been yet addressed in cerebral ischemia. The aim of this study was to analyze the protective effect of an effective dose of oxaloacetate and the human rGOT1 alone and in combination with a non-effective dose of oxaloacetate in an animal model of ischemic stroke. Sixty rats were subjected to a transient middle cerebral artery occlusion (MCAO). Infarct volumes were assessed by magnetic resonance imaging (MRI) before treatment administration, and 24 h and 7 days after MCAO. Brain glutamate levels were determined by in vivo MR spectroscopy (MRS) during artery occlusion (80 min) and reperfusion (180 min). GOT activity and serum glutamate concentration were analyzed during the occlusion and reperfusion period. Somatosensory test was performed at baseline and 7 days after MCAO. The three treatments tested induced a reduction in serum and brain glutamate levels, resulting in a reduction in infarct volume and sensorimotor deficit. Protective effect of rGOT1 supplemented with oxaloacetate at 7 days persists even when treatment was delayed until at least 2 h after onset of ischemia. In conclusion, our findings indicate that the combination of human rGOT1 with low doses of oxaloacetate seems to be a successful approach for stroke treatment.


Subject(s)
Aspartate Aminotransferase, Cytoplasmic/administration & dosage , Brain Ischemia/drug therapy , Oxaloacetic Acid/administration & dosage , Protective Agents/administration & dosage , Animals , Aspartate Aminotransferase, Cytoplasmic/blood , Aspartate Aminotransferase, Cytoplasmic/genetics , Brain/diagnostic imaging , Brain/drug effects , Brain Ischemia/diagnostic imaging , Brain Ischemia/enzymology , Disease Models, Animal , Humans , Male , Oxaloacetic Acid/blood , Protective Agents/metabolism , Radiography , Rats , Rats, Sprague-Dawley
13.
Obes Surg ; 24(2): 334-6, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24272887

ABSTRACT

Obesity-associated severe asthma is a distinct phenotype characterised by resistance to standard asthma therapies. Bariatric surgery appears to be a viable alternative for those who have failed trials of traditional weight loss methods. However, anaesthetic and surgical risks are potential barriers. We describe three patients with treatment-resistant obesity-associated severe asthma who underwent bariatric surgery without complications due to the multidisciplinary perioperative planning and care involved in these complex cases. All three patients showed improvements in asthma control and reduction in maintenance medication use post-surgery.


Subject(s)
Anti-Asthmatic Agents/administration & dosage , Asthma/complications , Asthma/drug therapy , Bariatric Surgery , Obesity/surgery , Adult , Asthma/physiopathology , Body Mass Index , Drug Administration Schedule , Female , Humans , Middle Aged , Obesity/complications , Obesity/physiopathology , Remission Induction , Severity of Illness Index , Weight Loss
14.
Phys Chem Chem Phys ; 15(43): 18752-70, 2013 Nov 21.
Article in English | MEDLINE | ID: mdl-23868502

ABSTRACT

We present our perspective on the theoretical basis of light-harvesting within the photosynthetic membrane. Far from being a static structure, the photosynthetic membrane is a highly dynamic system, with protein mobility playing an important role in the damage/repair cycle of photosystem II (PSII), in balancing the input of energy between PSI and PSII, and in the photoprotection of PSII in response to a sudden excess of illumination. The concept of a photosynthetic antenna is illustrated and the state transition phenomenon is discussed as an example of purposeful antenna mobility. We discuss fluorescence recovery after photo-bleaching as a technique for visualising membrane mobility, before introducing light-induced grana membrane reorganisation as an integral part of the rapid photoprotective switch in plants. We then discuss current theoretical approaches to modelling the energy transfer dynamics of the PSII antenna: the atomistic models of intra-complex transfer and the coarse-grained approach to the inter-complex dynamics. Finally we discuss the future prospect of extending these methods, beyond the static picture of the membrane, to the dynamic PSII photosynthetic antenna.


Subject(s)
Photosynthesis , Photosystem II Protein Complex/metabolism , Energy Transfer , Light-Harvesting Protein Complexes/chemistry , Light-Harvesting Protein Complexes/metabolism , Models, Molecular , Photobleaching , Photosystem II Protein Complex/chemistry , Plants/metabolism , Thylakoids/metabolism
15.
J Phys Chem B ; 117(25): 7605-14, 2013 Jun 27.
Article in English | MEDLINE | ID: mdl-23697375

ABSTRACT

Light-harvesting by the xanthophylls in the antenna of photosystem II (PSII) is a very efficient process (with 80% of the absorbed energy being transfer to chlorophyll). However, the efficiencies of the individual xanthophylls vary considerably, with violaxanthin in LHCII contributing very little to light-harvesting. To investigate the origin of the variation we used Time Dependent Density Functional Theory to model the Coulombic interactions between the xanthophyll 1(1)B(u)(+) states and the chlorophyll Soret band states in the LHCII and CP29 antenna complexes. The results show that the central L1 and L2 binding sites in both complexes favored close cofacial associations between the bound xanthophylls and chlorophyll a, implying efficient energy transfer, consistent with previously reported experimental evidence. Additionally, we found that the peripheral V1 binding site in LHCII did not favor close xanthophyll-chlorophyll associations, confirming observations that violaxanthin in LHCII is not an effective light-harvester. Finally, violaxanthin bound into the L2 site of the CP29 complex was found to be very strongly coupled to its neighboring chlorophylls.


Subject(s)
Chlorophyll/chemistry , Photosystem II Protein Complex/chemistry , Quantum Theory , Xanthophylls/chemistry , Binding Sites , Energy Transfer , Light-Harvesting Protein Complexes/chemistry , Light-Harvesting Protein Complexes/metabolism , Xanthophylls/metabolism
16.
J Colloid Interface Sci ; 394: 467-74, 2013 Mar 15.
Article in English | MEDLINE | ID: mdl-23313347

ABSTRACT

The interfacial behavior of silicone oils Oxane 1000 and Oxane 5700 (polydimethylsiloxanes, PDMS) interacting with dried or hydrated (hydration h=0.005 or 0.1g/g) silica gels Si-60 and Si-100 or nanosilica A-400 was studied using low-temperature (1)H NMR spectroscopy over the 210-310 K range. Broadening of the melting temperature range toward both sides from the freezing point is observed for silicone oils confined in mesopores (2-15 nm in radius) of silica gel particles (0.2-0.5 mm in size) or voids (1-100 nm) between silica nanoparticles (5-10 nm in size) in their aggregates. This effect is a consequence of the phase state heterogeneity, since both liquid and solid-like fractions of adsorbed PDMS are observed over a large temperature range. The adsorbed PDMS heterogeneity depends on the pore size distribution (confined space effect), and it is lower for silica gel Si-100 possessing broader pores than Si-60. An increase in the amounts of adsorbed polymer and water diminishes the effects of confined space on PDMS because a fraction of the polymers is located in broader pores or out of pores (voids). This leads to relative decrease in interactions of PDMS with the silica surface. (1)H NMR spectra of PDMS and n-decane bound to silica gels reveal much stronger heterogenization of adsorbed PDMS (depending on the polymer length) than that of the alkane.


Subject(s)
Dimethylpolysiloxanes/chemistry , Silica Gel/chemistry , Silicon Dioxide/chemistry , Silicone Oils/chemistry , Adsorption , Magnetic Resonance Spectroscopy , Models, Molecular , Nanoparticles/chemistry , Porosity , Surface Properties , Transition Temperature
17.
J Phys Chem B ; 117(38): 10974-86, 2013 Sep 26.
Article in English | MEDLINE | ID: mdl-23234311

ABSTRACT

Photoprotective non-photochemical quenching (NPQ) in higher plants is the result of the formation of energy quenching traps in the light-harvesting antenna of photosystem II (PSII). It has been proposed that this quenching trap is a lutein molecule closely associated with the chlorophyll terminal emitter of the major light-harvesting complex LHCII. We have used a combination of time-dependent density functional theory (TD-DFT) and the semiempirical MNDO-CAS-CI method to model the chlorophyll-lutein energy transfer dynamics of the highly quenched crystal structure of LHCII. Our calculations reveal that the incoherent "hopping" of energy from Chla612 to the short-lived, dipole forbidden 2(1)A(g)(-) state of lutein620 accounts for the strong fluorescence quenching observed in these crystals. This adds weight to the argument that the same dissipative pathway is responsible for in vivo NPQ.

18.
Phys Rev Lett ; 110(11): 117206, 2013 Mar 15.
Article in English | MEDLINE | ID: mdl-25166573

ABSTRACT

We discover that hcp phases of Fe and Fe(0.9)Ni(0.1) undergo an electronic topological transition at pressures of about 40 GPa. This topological change of the Fermi surface manifests itself through anomalous behavior of the Debye sound velocity, c/a lattice parameter ratio, and Mössbauer center shift observed in our experiments. First-principles simulations within the dynamic mean field approach demonstrate that the transition is induced by many-electron effects. It is absent in one-electron calculations and represents a clear signature of correlation effects in hcp Fe.

19.
Phys Rev Lett ; 107(20): 205504, 2011 Nov 11.
Article in English | MEDLINE | ID: mdl-22181745

ABSTRACT

The elastic properties of pure iron and substitutionally disordered 10 at. % Cr Fe-Cr alloy are investigated as a function of temperature by using first-principles electronic-structure calculations by the exact muffin-tin orbitals method. The temperature effects on the elastic properties are included via the electronic, magnetic, and lattice expansion contributions. We show that the degree of magnetic order in both pure iron and Fe(90)Cr(10) alloy mainly determines the dramatic change of the elastic anisotropy of these materials at elevated temperatures. The effect of lattice expansion is found to be secondary but also very important for quantitative modeling.

20.
J Phys Chem B ; 114(46): 15244-53, 2010 Nov 25.
Article in English | MEDLINE | ID: mdl-20964339

ABSTRACT

Spectroscopic measurements of Arabidopsis leaves have shown that the energy-dependent component of non-photochemical quenching (NPQ), known as qE, is associated with an absorption change at 535 nm (ΔA(535)). Identical measurements on the zeaxanthin-deficient mutant npq1 reveal a similar spectroscopic signature at 525 nm (ΔA(525)). We investigated whether these red-shifts may arise from excitonic interactions among homodimers of xanthophylls, zeaxanthin, and violaxanthin, bound at the peripheral V1 binding site on adjacent light-harvesting complex II (LHCII) trimers. Estimates of the relative geometries of these pigment pairs were obtained from the structure of LHCII. The excitonic couplings of zeaxanthin and violaxanthin dimers were probed using the time-dependent density functional theory method (TD-DFT). Calculations indicated that dimers formed between zeaxanthin or violaxanthin molecules using the published LHCII structure resulted in absorption blue shifts, typical of an H-type (parallel) geometry. In contrast, if the volume of the LHCII structure was modified to reflect the change in membrane thickness that occurs upon ΔpH formation, then both zeaxanthin and violaxanthin dimers adopted a J-type (collinear) geometry, and the resulting spectral shift was to the red region. The magnitudes of these predicted red-shifts are in good agreement with the experimental magnitudes. We therefore conclude that the observed xanthophyll red-shift results from the combination of both LHCII aggregation and changes in membrane thickness during qE. ΔA(535) may therefore be considered a "marker of aggregation" between LHCII trimers upon qE formation.


Subject(s)
Light-Harvesting Protein Complexes/chemistry , Models, Theoretical , Xanthophylls/chemistry , Arabidopsis/anatomy & histology , Arabidopsis/chemistry , Dimerization , Models, Molecular , Photosynthesis/physiology , Plant Proteins/chemistry , Protein Conformation , Quantum Theory , Thylakoids/chemistry , Thylakoids/ultrastructure , Zeaxanthins
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