Broadband and fine-structured luminescence in diamond facilitated by femtosecond laser driven electron impact and injection of "vacancy-interstitial" pairs.

Ultrafast heating of photoionized free electrons by high-numerical-aperture (0.25-0.65) focused visible-range ultrashort laser pulses provides their resonant impact trapping into intra-gap electronic states of point defect centers in a natural IaA/B diamond with a high concentration of poorly aggregated nitrogen impurity atoms. This excites fine-structured, broadband (UV-near-infrared) polychromatic luminescence of the centers over the entire bandgap. The observed luminescence spectra revealed substitutional nitrogen interaction with non-equilibrium intrinsic carbon vacancies, produced simultaneously as Frenkel "vacancy-interstitial" pairs during the laser exposure.

IR femtosecond laser micro-filaments in diamond visualized by inter-band UV photoluminescence.

Single microscale filaments were produced in monocrystalline Ia-type diamond by 1030 nm, 300 fs laser pulses tightly focused at NA = 0.3 and different peak powers, visualized by transverse imaging and spectrally characterized by longitudinal micro-spectroscopy, using intrinsic UV A-band photoluminescence (PL) with its peak at about 430 nm. Power-dependent scaling relationships for the local PL yield and diameters of the accompanying luminous micro-channels of recombining electron-hole plasma indicate a transition from three-photon absorption to free-carrier plasma absorption, as the consequent energy deposition mechanisms at increasing peak laser power. Power-dependent elongation of the luminous micro-channels versus peak laser power fitted by a Marburger formula yields, on average a diffraction-based estimate of 0.6 MW critical power for self-focusing within the diamond at the pump laser wavelength of 1030 nm.

Highly efficient stimulated Raman scattering of sub-picosecond laser pulses in BaWO4 for 10.6 µm difference frequency generation.

Transient stimulated Raman scattering (SRS) of 0.3 ps 515 nm laser pulses in ${\rm BaWO_4}$BaWO4 crystal was experimentally demonstrated with efficiency up to ${\sim}{20}\% $∼20% for the Stokes component with a wavenumber of ${\sim}{925}\;{{\rm cm}^{ - 1}}$∼925cm-1 in a simple single-pass geometry. This anomalous high efficiency was obtained due to the laser pulse self-phase modulation resulting in spectral broadening and seeding the SRS. The applicability of seed pulse production for a high-pressure sub-picosecond ${{\rm CO}_2}$CO2 laser amplifier via difference frequency generation in ${{\rm LiGaS}_2}$LiGaS2 crystal was numerically verified.

Assay of insulator enhancer-blocking activity with the use of transient transfection.

We used a transient transfection of cultured cells with linearized plasmids to analyze the enhancer-blocking activity of potential insulators including the standard cHS4 chicken beta-globin insulator and several DNA fragments selected from the human genome sequence. About 60-80% of the potential insulators do reveal the enhancer-blocking activity when probed by the transient transfection assay. The activity of different sequences is characterized by certain tissue specificity and by dependence on the orientation of the fragments relative to the promoter. Thus, the transfection model may be used for quantitative analysis of the enhancer-blocking activity of the potential insulators.

Functional dissection of an enhancer-like element located within the second intron of the human U2AF1L4 gene.

A detailed functional and evolutionary analysis of an enhancer element of the human genome (enhancer 12) located in the second intron of the U2AF1L4 gene, which we identified earlier, is presented. Overlapping fragments of the studied genome region were analyzed for enhancer activity, and the site responsible for the activity of this element was identified using transient transfections of HeLa cells. Comparison of the enhancer 12 sequence with orthologous sequences from seven primate species revealed the existence of evolutionarily conserved sequences within this element. One of the identified conservative regions is likely responsible for the enhancer activity and is able to specifically interact in vitro with proteins of HeLa cell nuclear extract. The ability of orthologous primate sequences to compete with enhancer 12 for binding with HeLa cell nuclear extract proteins and to enhance the activity of the reporter gene in transient transfection of HeLa cells is demonstrated.

Ab initiocalculations of the phase diagrams of tin and lead under pressures up to a few TPa.

The paper studies relative structural stability for various crystal phases of tin and lead from first principles with the full-potential all-electron full-potential all-electron linear muffin-tin orbital method to pressures of a few TPa both at zero temperature and atT> 0. Using data from our calculations we construct phase diagrams for the two metals in the region of very high compressions and obtain their melting curves. For tin at pressures <100 GPa and zero temperature, we did not find the region of stability of the body-centered orthorhombic (bco) phase, as it was earlier observed in experiments by Salamatet al[2013Phys. Rev.B88104104]. Our calculations suggest that one structural transition from the tetragonal to cubic phase, bct → bcc, occurs in perfect Sn crystal atT= 0 K in the pressure range of about 27-32 GPa. But any deviation from perfection may cause an orthorhombic distortion of its tetragonal phase. At pressures above 100 GPa, the bcc → hexagonal close-packed (hcp) transition exists in both metals, and the phase boundary has a domed shape and does not rise in temperature above 2 kK. This behavior of the phase boundary with the increasing temperature is caused by the softer phonon modes of the bcc structure and the smaller contribution of lattice vibrations to the free energy of the crystal compared to the hcp phase. At pressures above 2.5 TPa andT≲ 1 kK, lead can also undergo another structural transition, hcp → fcc, but atT> 1.5 kK there must exist the more energetically preferable bcc → fcc transition.

A wide-range multiphase equation of state for platinum.

The paper presents a semi-empirical wide-range equation of state (EOS) for platinum with account for melting, evaporation, and ionization. The equation is based on a wide spectrum of experimental and calculation data. Parameters for the EOS were adjusted using a genetic algorithm which proved to perform well for optimizations in big data processing. In the regions where no experimental data were available, we used results of first-principles and average-atom model calculations. The EOS was used to calculate the melting curve of platinum to pressures above 1 TPa, sound velocities along the Hugoniot curve, parameters of melting under shock compression, and parameters of the critical point. An improved model is proposed for the shear modulus in (V, T) coordinates and its variation along the shock adiabat is calculated.

Ab initio calculations of the elastic and thermodynamic properties of gold under pressure.

The paper presents first-principles FP-LMTO calculations on the relative stability of fcc, bcc, hcp and dhcp gold under pressure. They were done in local density approximation (LDA), as well as in generalized gradient approximation (GGA) with and without spin-orbit interaction. Phonon spectra for the considered gold structures were obtained from LDA calculations within linear response theory and the contribution of lattice vibrations to the free energy of the system was determined in quasiharmonic approximation. Our thorough adjustment of FP-LMTO internal parameters (linearization and tail energies, the MT-sphere radius) helped us to obtain results that agree well with the available experimental phase relation Dubrovinsky et al (2007 Phys. Rev. Lett. 98 045503) between fcc and hcp structures of gold under pressure. The calculations suggest that gold compressed at room temperature successively undergoes the following structural changes: [Formula: see text]. The paper also presents the calculated elastic constants of fcc, bcc and hcp Au, the principal Hugoniot and the melting curve. Calculated results were used to construct the PT-diagram which describes the relative stability of the gold structures under study up to 500 GPa.

In trans promoter activation by enhancers in transient transfection.

Earlier, it was reported that the strong cytomegalovirus enhancer can activate the cytomegalovirus promoter in trans, i.e. as a separate plasmid co-transfected with a promoter-reporter gene construct. Here we demonstrate that the ability of enhancers to activate promoters in trans in transient transfection experiments is a property of not only viral regulatory elements but also of various genomic enhancers and promoters. Enhancer-promoter activation in trans is promoter- and cell type-specific, and accompanied by physical interaction between promoter and enhancer as revealed by chromosome conformation capture assays. Thus, promoter activation in transient co-transfection of promoters and enhancers shares a number of important traits with long-distance promoter activation by enhancers in living cells and may therefore serve as a model of this fundamental cellular process.

[Effects of cystamine on the state of peripheral blood neutrophilic granulocytes in vivo in rats]. / Vliianie tsistamina na sostoianie neirofil'nykh granulotsitov perifericheskoi krovi krys in vivo.

It has been found experimentally, that decay of the intercellular energy exchange, intensification of the secretory degranulation, activation of the oxygen-dependent enzyme system and increasing the functional potential of the male-rats neutrophils took place on the height of the protective action of cystamine. On the 1-st day the tendency to restoration was noted and the normalisation of the functional and metabolical status of the neutrophils could be seen on the 5-th day after injection.

[Quantitative measurement of muscle and joint sensitivity in focal brain lesions]. / Kolichestvennaia otsenka myshechno-sustavnoi chuvstvitel'nosti pri ochagovykh porazheniiakh mozga.

A method is suggested of quantitative evaluation of disorders of musculoarticular sensitivity from the time of ordinary motor reaction to passive movement of a finger (BR). The method is based on an examination of 16 normal test subjects and 75 patients with focal injuries of the brain. It was established that upon preservation of the pathways and centers of deep sensitivity, there were no differences between BR in response to stimulation of the right and left hand. In patients with a pathological focus in the somatosensory area, BR to passive movement of the hand contralateral to the affected hemisphere was greater than that to the stimulation of the analogous hand. BR was made use of to recognize the involvement of the parietal area even where it was not found during neurological examination. During repeated examinations changes in BR reflected the time course of the pathological process in the somatosensory area of the brain.

[The Korsakov syndrome in light of the concept of functional asymmetry of the brain]. / Korsakovskii sindrom v svete kontseptsii funktsional'noi asimmetrii mozga

An analysis of 10 cases with acute brain disorders (severe brain damage, ruptures of vascular aneurysms permits the authors to assume that the Korsakoff syndrome developes in those patients who at the initial phase of the disease had comatose conditions with subsequent focal symptoms mainly of the right hemisphere and diencephalic area. The author demonstrates the psychopathological traits of the Korsakoff syndrome which differ from the amnestic syndrome developing in focal lesions of the left hemisphere.

[Computation disorders in the clinical picture of focal brain lesions]. / Narusheniia scheta v klinike ochagovykh porazhenii golovnogo mozga.

Disturbances of calculation were studied in 76 patients with arterio-venous aneurysms, located in the left and right hemisphere. An analysis of errors made by the patients in the process of calculation makes it possible to assume that in the organization of calculation functions, both hemispheres are involved, but the different stages of it have different morphological and functional bases. It was demonstrated that the right hemisphere provides the proceeding of the most automatized links during calculation.

[Dynamics of neuropsychological symptomatics following endovascular surgical interventions]. / Dinamika neiropsikhologicheskoi simptomatiki pri éndovaskuliarnykh khirurgicheskikh vmeshatel'stvakh

The paper is concerned with the neuropsychological symptomatology due to arterio-venous cerebral vascular aneurysmas. The authors report of the development of such signs following occlusions of the afferent vessells in aneurysmas in 19 patients. The study permitted to distinguish the possible genesis of disturbed cerebral functions which are related directly with the aneurysm localization and with intracerebral hematomas, as well as with the hemodynamical factors. The authors diplay the changed structure of the neuropsychological syndrome in reconstructed cerebral circulation following arterial occlusion, supplying the aneurysma. The achieved data allow one to consider the clinicopsychological method as a rather refined indicator of reconstructed cerebral circulation.

[Neuropsychological approach to detecting the anterior, middle and posterior cerebral artery "steal" syndromes]. / Neiropsikhologicheskii podkhod k vyiavleniiu sindromov "abkradyvaniia" perednei, srednei i zadnei mozgovykh arterii.

Neuropsychological symptoms of "robbing" the anterior, median, and posterior cerebral arteries due to the ischemia caused within their basins by arteriovenous aneurisms were studied. The disappearance of the "robbing" symptoms after occluding the influx vessels of the aneurism by a separable balloon-catheter (62 observations), or after radical excision of the arteriovenous aneurism (81 observations) was taken for the control. The dynamics of the "robbing" symptoms in the process of the endovascular operations was followed. The importance of the "robbing" and the local symptoms associated with the localization of the vascular conglomerate for the clinic of arteriovenous aneurisms is demonstrated. A high sensitivity of the neuropsychological tests to changes of the cerebral hemodynamics is noted.

[Neuropsychological analysis of disorders in the constructive activity of patients with arteriovenous aneurysms of temporal localization]. / Neiropsikhologicheskii analiz narushenii konstruktivnoi deiatel'nosti u bol'nykh s arteriovenoznymi anevrizmami temennoi lokalizatsii.

Disturbances of the constructive praxis were studied in 40 patients with arteriovenous aneurysms of the parietal lobes in the right and left hemispheres. Errors made by the patients engaged in tests on turning over figures were subjected to qualitative and quantitative analyses. It was demonstrated that disturbed constructive praxis is underlain by disordered spatial synthesis and defects of image perception. The former factor determines disturbances of constructive activity in lesions of both left and right hemispheres, whereas the latter one determines disturbances of constructive activity in patients with disfunctions of the right parietal lobe. In these patients the disorders are more pronounced and availability of a visual model does not help to compensate the defect.

[Mechanism of stimulation of the motor activity of the stomach by the greater splanchnic nerve]. / Mekhanizm stimuliatsii dvigatel'noi aktivnosti zheludka bol'shim chrevnym nervom.

The activating effect of the splanchnic nerve on motor activity of the gastro-intestinal tract could not be eliminated either with bilateral vagotomy or separate or joint administration of ornid and benzohexonium, but could be well prevented with atropin blockade of the vegetative ganglia M-serotoninergic receptors as well as diprazin blockade of the smooth muscle D-serotoninergic receptors. The data obtained reveal non-cholinergic and non-adrenergic fibers in the thoracic portion of the major splanchnic nerve which exert obvious activating effect on the stomach contractile function, serotonin being their transmitter.

[Evaluation of cell nitrogen and phosphorus quotas in accumulative cultures of chlorococcous algae]. / Otsenka kletochnykh kvot azota i fosfora v nakopitel'nykh kul'turakh khlorokokkovykh vodoroslei.

A conceptual model of cell quota was proposed and the parameters were determined that characterize the quota dynamics during the development of algae. Based on the experimental and empirical-statistical procedures of analysis, the basal parameters of cell quotas of nitrogen and phosphorus were obtained for four species of chlorococcous algae. The data were also obtained on a variability of nitrogen and phosphorus quotas during the development of algae, as well as coefficients of excessive accumulation. The phosphorus quota changed within the limits of three orders of magnitude and the nitrogen quota, within the limits of one order. The highest coefficients of excessive accumulation were 52 and 1.8 for phosphorus and nitrogen, respectively.

[Arterial aneurysms of the petrous portion of the carotid artery]. / Arterial'nye anevrizmy kamenistoi chasti sonnoi arterii.

The authors report on 3 patients with arterial aneurysms of the petrous part of the carotid artery which in 2 of them were manifested by profuse recurrent hemorrhages from the external acoustic meatus. The aneurysm was caused by penetrating injury of the middle ear in one patient and injury inflicted during surgery on the middle ear for purulent otitis and mastoiditis in another. Hemorrhages in the third patient occurred during exacerbation of chronic purulent inflammation of the middle ear. The diagnosis of aneurysm was made by cerebral angiography in combination with the method of substruction of the temporal bone structures. In 2 patients with aneurysms of this localization which is difficult for access were completely excluded from circulation by the endovascular method using a balloon catheter. The third patient was not operated on because of spontaneous thrombosis of the cervical segment of the carotid artery. The authors analyse the pathogenesis, clinical course, diagnosis and methods for the management of such aneurysms. They claim that the endovascular method with use of a balloon catheter is most effective for arresting the flow of blood through aneurysms of such localization and for arresting profuse hemorrhages from the external acoustic meatus.

[Computed tomographic diagnosis of paraganglioma of the base of the skull]. / Komp'iuterno-tomograficheskaia diagnostika paragangliom osnovaniia cherepa.

On the basis of examination of 30 patients with the diagnosis of paragangliomas of the base of the skull the following main computed tomographic signs of this group of tumors were revealed: destruction of bone structures of the base of the posterior and middle cranial fossae, erosion and widening of the jugular foramen; diminished pneumatization of the air cells of the mastoid process; extracranial simultaneous with intracranial spreading of the tumor. A classification of paragangliomas is suggested.