Single-pass Cr:ZnSe amplifier for broadband infrared undulator radiation

An amplifier based on a highly-doped chromium zinc-selenide (Cr:ZnSe) crystal is proposed to increase the pulse energy emitted by an electron bunch after it passes through an undulator magnet. The primary motivation is a possible use of the amplified undulator radiation emitted by a beam circulating in a particle accelerator storage ring to increase the particle beam's phase-space density-a technique dubbed optical stochastic cooling (OSC). This paper uses a simple four energy level model to estimate the single-pass gain of Cr:ZnSe and presents numerical calculations combined with wave-optics simulations of undulator radiation to estimate the expected properties of the amplified undulator wave-packet.

[Periodontal diseases and complicated pregnancy]

PURPOSE

Based on the datas available in the modern literature, to conduct a study on the effect of dental diseases on the course of pregnancy and outcome; mainly, the impact of periodontal disease on the low birth weight of the newborn and premature birth.

MATERIAL AND METHODS

This article is based on the study of materials from foreign and domestic studies found in the databases Pubmed and Elibrary. Literature data were used for the last 15 years.

RESULTS

The majority of pregnant women who are not receiving due dental examination and suffering with those or other diseases of the oral cavity have an unfavorable outcome of pregnancy, including premature births and low weight of the premature newborn. The role of the chronic effect of oral microorganisms Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nudeatum, as well as local increase in prostaglandin E₂ (PGE₂) and tumor necrosis factor (TNF-α), in the implementation of the inflammatory reaction leading to a decrease in the weight of the fetus by 15-18%.

CONCLUSION

Due to the conducted research it was established that periodontal diseases and other infectious diseases of the oral cavity negatively affect the course of pregnancy and its outcome. The main problems were the lack of women's health education in terms of preparing for pregnancy and sanitation of foci of infection in the oral cavity both before pregnancy and at the time, as well as poor access to the dentist and not receiving proper prevention and, if necessary, treatment of oral diseases.

Spontaneous MXene monolayer assembly at the liquid-air interface

Here we report on the spontaneous assembly of Ti₃C₂T_x MXene flakes into monolayer films at the liquid-air interface. According to X-ray reflectivity and grazing incidence X-ray fluorescence both the structure of the layers and assembly kinetics depends on the pH value of the solution. At pH > 4 MXene flakes form a single ∼1.5 nm thick layer carrying a negative charge, while in the acidic medium the layer contains coordinated anions with the formation of the Br_aq^-/Ti₃C₂T_x/subphase interface. The surface layer compression allows the assembling of MXene flakes into a dense monolayer films with the surface coverage of up to 96% and surface pressure exceeding 40 mN m^-1 in the case of the acidic subphase. The films can readily be transferred onto solid substrates by the conventional Langmuir-Blodgett approach or modified by surfactants to form MXene/surfactant composite films.

The Structural Arrangement and Relative Abundance of Aliphatic Units May Effect Long-Wave Absorbance of Natural Organic Matter as Revealed by 1H NMR Spectroscopy

The objective of this study was to shed light on structural features which underlay intensity of long wave absorbance of natural organic matter (NOM) using ¹H NMR spectroscopy. For this purpose, a set of the NOM samples was assembled from arctic and nonarctic sampling sites (the Kolyma river basin and Moscow region, respectively). It was to ensure a substantial difference in the humification degree of the isolated organic matter-the biogeochemical proxy of the long-wave absorbance of NOM. The assembled NOM set was analyzed using solution-state ¹H NMR spectroscopy. The distribution of both backbone and exchangeable protons was determined using acquisition of spectra in three different solvents. The substantially higher contribution of nonfunctionalized aliphatic moieties CHn (e.g., materials derived from linear terpenoids, MDLT) in the arctic NOM samples was revealed as compared to the nonarctic ones. The latter were characterized with the higher content of CHα protons adjacent to electron-withdrawing groups which belong to carboxyl rich alicyclic moieties (CRAMs) or to aromatic constituents of NOM. We have calculated a ratio of CHn to CHα protons as a structural descriptor which showed significant inverse correlation to intensity of long wave absorbance assessed with a use of E₄/ E₆ ratio and the slope of absorption spectrum. The steric hindrance of aromatic chromophoric groups of the NOM ensemble by bulky nonfunctionalized aliphatic moieties (e.g., MDLT) was set as a hypothesis for explanation of this phenomenon. The bulky aliphatics might increase a distance between the interacting groups resulting in inhibition of electronic (e.g., charge-transfer) interactions in the NOM ensemble. The obtained relationships were further explored using Fourier transform mass spectrometry as complementary technique to ¹H NMR spectroscopy. The data obtained on correlation of molecular composition of NOM with ¹H NMR data and optical properties were very supportive of our hypothesis that capabilities of NOM ensemble of charge transfer interactions can be dependent on structural arrangement and relative abundance of nonabsorbing aliphatic moieties.

Temperature Effect on the Stability of the Polarized State Created by Local Electric Fields in Strontium Barium Niobate Single Crystals

The stability of ferroelectric domain patterns at the nanoscale has been a topic of much interest for many years. We investigated the relaxation of the polarized state created by application of a local electric field using a conductive tip of a scanning probe microscope for the model uniaxial relaxor system Sr_xBa_1−xNb₂O₆ (SBN) in its pure and Ce-doped form. The temporal relaxation of the induced PFM contrast was measured at various temperatures. The average value of the induced contrast decreases during heating for all investigated crystals. Below the freezing temperature the induced state remains stable after an initial relaxation. Above the freezing temperature the induced state is unstable and gradually decays with time. The stability of the induced state is strongly affected by the measuring conditions, so continuous scanning results in a faster decay of the poled domain. The obtained effects are attributed to a decrease of the induced polarization and backswitching of the polarized area under the action of the depolarization field.

[Efficacy of remote gamma-therapy in patients with juvenile angiofibroma of the base of the skull]

The results of radiation therapy of 48 patients with juvenile nasopharyngeal angiofibroma were analysed. It was found that radiation therapy can produce 80% stable remissions in postoperative recurrence or unresectable tumor. The response did not depend on primary size of the tumor and was better in a total dose over 35 Gy and in children over 14 years of age. Long-term side effects were minimal and did not deteriorate quality of life.

[Rat mesoaccumbocingulate dopaminergic system and brain emotional functions]

The authors suggest to distinguish the mesoaccumbocingulate dopaminergic system within the mesocorticolimbic dopaminergic system. It defines the formation of dependence on the influence of psychoactive drugs. The cortical center of the mesoaccumbocingulate dopaminergic system--anterior cingulate fields in rats (Cg1 and Cg3)--simultaneously represents the affective and motivation-mnestic center. The affective function of the rat anterior cingulate fields after the administration of psychoactive drugs, as well as the formation of dependence on them, is associated with the distribution of the dopaminergic endings of midbrain neurons in the nucleus accumbens and at the anterior cingulate fields, in particular, in the pregenual part.

[Concentrations of somatotropin and prolactin in the follicular fluid and blood serum of cows in different phases of the estrous cycle]

Comparative investigations of somatotropin and prolactin contents in the fluid of antral follicles and blood serum of cows in different phases of the oestrous cycle were performed. The somatotropin concentration in the fluid was shown to rise with increasing the follicle diameters from 3-5 to 6-10 mm in the follicular phase and to decrease in follicles of diameter 11-20 mm in the luteal phase. The prolactin concentration was higher in the fluid of follicles 11-20 mm in diameter than in those of 3-5 mm in diameter in the follicular phase and did not depend on the follicle size in the luteal phase. Concurrently, the prolactin content in follicles 3-5 mm in diameter was higher in the luteal than follicular phase of the cycle. As compared to the follicular phase, an increase in the prolactin concentration in the bovine blood serum during the luteal phase was also found. The data obtained indicate that changes in the somatotropin and prolactin contents in the follicular fluid are related to processes regulating growth and development of antral follicles depending on the phase of oestrous cycle and to changes in the blood hormone concentrations as well.

[Prolactin and somatotropin binding by granulosa cells of cows at different reproductive states]

Specific binding of bovine prolactin and somatotropin by granulosa cells from the antral follicles of various diameters was studied in cows at different reproductive states, prepubertal, pubertal, and early gestation. The ability of granulosa cells to bind prolactin did not depend on the reproductive state of an animal. At the same time, the dynamics of somatotropin specific binding by granulosa cells during maturation of the antral follicles differed at dissimilar reproductive states of the cows. When the diameter of follicles increased from 3-5 to 6-10 mm, specific binding of 125I-somatotropin decreased in pubertal animals, but remained unchanged in the prepubertal and pregnant animals. The results of Scatchard analysis of the binding data suggest that sexual maturation of cows did not affect the binding of prolactin and somatotropin by granulosa cells from follicles of 1-2 mm in diameter. The data obtained suggest that the decreased sensitivity of granulosa cells to somatotropin at the terminal stages of maturation of the antral follicles is essential for their development and acquisition of the ability for ovulation.

[Prolactin-binding activity of bovine granulosa cells on luteinization and exposure to somatotropin in vitro]

The influence of luteinization and bovine somatotropin (ST, 5-50 ng/ml) during cultivation of bovine granulosa cells on their ability to bind [125I]-labeled bovine prolactin (PRL) was studied. On the second day of cultivation in serumfree medium, granulosa cells from immature antral follicles underwent spontaneous luteinization, in both the absence and presence of ST. The level of [125I]-PRL specific binding to cells increased after two days of cultivation, with a negative correlation being revealed between estradiol production by the cells and their PRL-binding activity. At the same time, the addition of ST to the culture medium had no effect on the level of [125I]-PRL specific binding to native and luteinizing granulosa cells. The findings suggest a stimulatory influence of the luteal differentiation process on the PRL-binding activity of bovine granulosa cells, this influence is independent of the action of ST.

Characterization of somatotropin- and prolactin-binding sites on bovine granulosa cells using homologous hormones

Specific binding of bovine somatotropin (BST) and bovine prolactin (BPRL) to cow granulosa cells from antrum-containing follicles of different diameter was studied. Scatchard analysis of the data revealed a single type of low affinity BST-binding sites on the granulosa cells with dissociation constants similar to those for the BPRL-binding sites. The number of BST-binding sites on the cells decreased with increasing follicle diameter from 3-5 to 6-10 mm. However, the binding capacity to BPRL decreased only in the case of cells from follicles 11-20 mm in diameter. The findings are discussed in relation to the "homologous binding" phenomenon.

[Surgical, radiation and combined treatment of multiple primary malignancies of the respiratory system]

Surgery for primary multiple malignant tumors of the respiratory system was carried out in 141 patients. Reconstruction, plastic operations and sparing resections were performed in 79 cases (68.5%). Five-year survival after radical surgery was 43.8%.

[Reciprocal modulation of regulatory action of prolactin and somatotropin on DNA synthesis in granulosa cells of cows]

A comparative analysis of the individual and joint influence of bovine prolactin (BPRL) and bovine somatotropin (BST) on DNA synthesis in cultured bovine granulosa cells from follicles of 3-5 mm in diameter was conducted, and a possibility for regulation of BPRL binding to receptors on the cells by BST was examined. Despite a unidirectional growth-promoting action of BPRL and BST on granulosa cells, their joint mitogenic effect on the cells was not additive at low concentrations of BPRL. The addition of BST to the culture medium did not alter the biphasic character of dependence of DNA synthesis in the cells on BPRL concentration, but increased the maximum effective concentration of the latter. When culturing granulosa cells with BST, the absence of its influence on the level of BPRL specific binding to the cells was shown. This fact suggests that BST modulating action on the mitogenic effect of BPRL is not a result of a change in the number of free receptors for PRL on granulosa cells. The results obtained are discussed in relation to the notion of similarity of receptor functional properties and intracellular signal ways for PRL and ST.

[Neurochemical organization of the brain reinforcing systems]

Modern concepts of neurophysiological mechanisms of the brain reinforcing systems are reviewed from A.A. Ukhtomsky's concept of dominanta. The brain mesocorticolimbic system was shown to play a key role in functioning of the brain reinforcing systems. Morphological and neurochemical organisation of this system determining the emotional sphere, was studied. The dopamine system was found to be the main neurochemical tool of the mesocorticolimbic system. Other transmitters, neuromodulators, and hormones play a regulatory role in the latter. The data obtained corroborate the authors' concept of fluctuating emotional gradient.

[Malignant lymphoproliferative lesions of the trachea]

Detailed review of literature and analysis of 4 authors's cases of the trachea non-Hodgkin lymphoma and lymphogranulomatosis are presented.

[Primary melanoma of the respiratory tract]

4 cases of melanoma of the respiratory tract (trachea and bronchi) are analysed clinico-morphologically. A case of melanoma with a primary multiple location (trachea and the main bronchus), rapid recurrence after surgery and radiation therapy is described in detail. Melanocytic nature of the tumor is proved immunohistochemically.

Prolactin in follicular fluid and intracellular store calcium in follicular cells are related to morphological signs of ovarian follicle atresia in cows: work in progress

It is known that prolactin (PRL) is the third pituitary hormone serving gonadotropic function in mammals. However, its role in the regulation of ovarian folliculogenesis and, in particular, its relationship to follicular atresia as well as the mechanism of its influence on follicular cells are poorly understood. We investigated PRL levels in follicular fluids (FFs) and intracellular store calcium ([Ca2+]is) in cell walls of bovine ovarian follicles with diameters of 10 to 20 mm and their relationship to follicular atresia. Ovarian follicles were categorized on the basis of macroscopic criteria and of microscopic examination of granulosa cell (GC) smears. Prolactin concentrations in FFs were measured by RIA and levels of [Ca2+]is in follicular cells were determined by using the fluorophore chlortetracycline. Compared to atretic follicles, morphologically normal follicles were characterized by higher concentrations of PRL in FFs (P < 0.001) and lower contents of [Ca2+]is in follicular cells (P < 0.01). Furthermore, follicles containing no more than 20% of pycnotic GCs had higher levels of PRL in their fluids than those containing over 40% of pycnotic GCs (P < 0.05). Finally, the direct effect of PRL on [Ca2+]is content in follicular cells was studied in vitro. Compared to control, PRL decreased (P < 0.001) the levels of [Ca2+]is in the cells after 24 h culture of follicular walls from morphologically normal follicles in TCM 199 supplemented by 10% fetal calf serum. Our findings suggest that the decline of PRL concentrations in FFs and the rise of [Ca2+]is contents in follicular cells are related to atresia of large bovine follicles and that there appears to be a relationship between the two biochemical parameters.

[Changes in the content of prolactin and somatotropin and the level of their binding with cells in the growing antral follicles of cows]

The hormone concentrations in the follicular fluid rise along with an increase in follicular diameter whereas the level of their binding to cells declines. The findings suggest that two basic parameters characterizing the degree of prolactin and somatotropin actions on granulosa cells develop in different directions in the course of antral follicle maturation.

[The dynamics of the somatotropin content in the follicular fluid during maturation and atresia of the antral follicles in bovine ovaries]

Somatotropin level was shown to rise in follicular fluid from bovine ovaries during the follicular growth stage with increasing of the follicular diameter from 3-5 to 6-10 mm. Follicles with the diameter of 10-20 mm containing over 40% of pycnotic granulosa cells revealed lower levels of somatotropin in their fluid as compared with those containing 20% or lesser amount of pycnotic cells. The data obtained suggest a direct involvement of somatotropin in regulation of the growth and atretic processes in antral bovine ovarian follicles.