Predissociation dynamics of the hydroxyl radical (OH) based on a five-state spectroscopic model.

Multi-reference configuration interaction potential energy curves (PECs) and spin-orbit couplings for the X 2Π, A 2Σ+, 1 2Σ-, 1 4Σ-, and 1 4Π states of OH are computed and refined against empirical energy levels and transitions to produce a spectroscopic model. Predissociation lifetimes are determined by discretizing continuum states in the variational method nuclear motion calculation by restricting the calculation to a finite range of internuclear separations. Varying this range gives a series of avoided crossings between quasi-bound states associated with the A 2Σ+ and continuum states, from which predissociation lifetimes are extracted. 424 quasi-bound A 2Σ+ state rovibronic energy levels are analyzed, and 374 predissociation lifetimes are produced, offering good coverage of the predissociation region. Agreement with measured lifetimes is satisfactory, and a majority of computed results were within experimental uncertainty. A previously unreported A 2Σ+ state predissociation channel that goes via X 2Π is identified in the calculations. A Python package, binSLT, produced to calculate predissociation lifetimes, associated line broadening parameters, and lifetime uncertainties is made available. The PECs and other curves from this work will be used to produce a rovibronic ExoMol line list and temperature-dependent photodissociation cross sections for the hydroxyl radical.

Photoswitchable Photochromic Chelating Spironaphthoxazines: Synthesis, Photophysical Properties, Quantum-Chemical Calculations, and Complexation Ability.

The stable and efficient photochromic and photoswitchable molecular systems designed from spirooxazines are of increasing scientific and practical interest because of their present and future applications in advanced technologies. Among these compounds, chelating spironaphthoxazines have received widespread attention due to their efficient optical response after complexation with some metal ions being of biomedical interest and environmental importance, as well as their good cycle performance and high reliability, especially by metal ion sensing. In this mini-review, we summarize our results in the design of novel photoswitchable chelating spironaphthoxazines with specific substituents in their naphthoxazine or indoline ring systems in view of recent progress in the development of such molecular systems and their applications as metal ion sensors. The design, synthesis methods, and photoresponse of such spirooxazine derivatives relevant to their applications, as well as quantum-chemical calculations for these compounds, are presented. Examples of various design concepts are discussed, such as sulfobutyl, hydroxyl, benzothiazolyl, or ester and carboxylic acid as substituents in the chelating spironaphthoxazine molecules. Further developments and improvements of this interesting and promising kind of molecular photoswitches are outlined.

Control of Coherent Light through Microperiodic Director Modulation in Nematic Films under Low-Voltage DC Electric Field.

This work addresses the achievement of efficient control of laser light transmission through stationary microperiodic parallel stripe textures formed in films of nematic liquid crystals (NLCs) in planar-oriented cells upon a direct-current (DC) electric field. By varying the field intensity and, thereby, the field-induced periodic modulation of the nematic director and hence the complex transmittance function corresponding to the longitudinal domain texture induced in NLC films with initial planar alignment, the intensity of a linearly polarized laser beam passed through the films can be well controlled. In 25 µm-thick films of room-temperature NLCs pentylcyanobiphenyl (5CB), this results in a low-voltage (~4 V) sharp and deep V-shaped behavior of their electro-optically controlled transmittance. Such a reversible electro-optical effect is interesting for active control of laser beam intensity and other applications. The relevant physical mechanism is analyzed and explained.

Photoluminescent Thin Films of Room-Temperature Glassy Tris(keto-hydrozone) Discotic Liquid Crystals and Their Nanocomposites with Single-Walled Carbon Nanotubes for Optoelectronics.

This study addresses the photoresponse of liquid-crystalline tris(keto-hydrozone) discotic (TKHD)-a star-shaped molecular structure with three branches. Object of our research interest was also TKHD filled with single-walled carbon nanotubes (SWCNTs) at a concentration of 1 wt %. At room temperature, the discotic liquid crystals in thin films (thickness 3 µm) of both TKHD and nanocomposite SWCNT/TKHD were in a glassy state. Such glassy thin films exhibited photoluminescence ranging from the deep-red to the near-infrared spectral region, being attractive for organic optoelectronics. The addition of SWCNTs to TKHD was found to stabilize the photoluminescence of TKHD, which is of significance for optoelectronic device applications. The photothermoelectrical response of highly conductive SWCNT/TKHD nanocomposite films was characterized by electrical impedance spectroscopy in the frequency range from 1 Hz to 1 MHz of the applied electric field. It was elucidated that the reversible photothermoelectrical effect in SWCNT/TKHD films occurs through SWCNTs and their network.

Ion-Conducting Composites of Polymers and Nematic Liquid Crystals.

In the present mini-review are discussed the findings reported in the last five years on the ion-conducting composites of polymers and molecules of nematic liquid crystals (NLCs), as well as their applications at present and in the future. Nowadays, free-standing and flexible thin films of such organic composite electrolytes synthesized from plastics and nematic soft matter are among the technically important materials and components for use in energy storage and conversion devices and in organic soft electronics, sensorics, and mechatronics. Although the physicochemical mechanisms and effects in the ion-conducting polymer/NLCs composites are well understood, the possibility to find additional ways for improving their electrical conductivity and dielectric and mechanical properties is a challenge. The efforts in this research direction are important for the development of novel ion-conductor materials and further diversification of their applications. This mini-review is focused on the key characteristics of ion-conducting polymer/NLCs composites and the new trends in their fabrication. With relevant examples, the vast research opportunities, some proposed improvements, and the creative ideas associated with these advanced materials and their intelligent use are outlined.

Ion-Conducting Flexible Thin Films of Composites from Poly(ethylene oxide) and Nematic Liquid Crystals E8-Characterization by Impedance and Dielectric Relaxation Spectroscopy.

Complex electrical impedance and dielectric spectroscopy were applied to study the dielectric relaxations and their thermal behavior in ion-conducting composites/complexes from polymer poly(ethylene oxide) (PEO) and E8 nematic liquid crystals (LCs), at the compositional ratio PEO:E8 = 70:30 wt%. Flexible thin films of PEO/E8 with a thickness of 150 µm were inspected, as well as such films from Na+ ion-conducting electrolyte PEO/E8/NaIO4 with the same PEO:E8 compositional ratio, but additionally containing 10 wt.% from the salt sodium metaperiodate (NaIO4) as a dopant of Na+ ions. The molecular dynamics, namely the dielectric relaxation of PEO/E8 and PEO/E8/NaIO4, were characterized through analyses of complex impedance and dielectric spectra measured in the frequency range of 1 Hz-1 MHz, under variation of temperature from below to above the glass-transition temperature of these composites. The relaxation and polarization of dipole formations in PEO/E8 and PEO/E8/NaIO4 were evidenced and compared in terms of both electrical impedance and dielectric response depending on temperature. The results obtained for molecular organization, molecular relaxation dynamics, and electric polarization in the studied ion-conducting polymer/LC composites/complexes can be helpful in the optimization of their structure and performance, and are attractive for applications in flexible organic electronics, energy storage devices, and mechatronics.

A Technical Problem in Diagnosis Clarity of Solitary Spinal Cord Neurofibroma in an Eleven-month-old Boy.

Spinal neurofibroma is one of the rarest of the neoplasms involving the spinal cord or roots and occurs much less often than neurinoma, meningioma or glioma. The sixth pediatric case of solitary intramedullary tumor was described in 2013, according to B. Eljebbouri et al. We present a rare, difficult to diagnose and may-be the seventh pediatric case of solitary neurofibroma of the cauda equine in an 11-month-old infant. The patient underwent a laminectomy of T12, L1, L2 and L3, extirpation of intradural, intramedullary and extramedullary spinal cord tumor. The patient is fully recovered for 5 years of monitoring. Although rare, spinal neurofibromas in children should be diagnostically considered and radically treated for a favorable outcome.

Gradient polymer-disposed liquid crystal single layer of large nematic droplets for modulation of laser light.

The light modulating ability of gradient polymer-disposed liquid crystal (PDLC) single layer of large droplets formed by nematic E7 in UV-cured polymer NOA65 is studied. Operating at relatively low voltages, such PDLC film with a of thickness 10-25 µm and droplet size up to 50 µm exhibits a good contrast ratio and is capable of producing a large phase shift for the propagating coherent light. For a linearly polarized He-Ne laser (λ=633 nm), an electrically commanded phase shift as large as π/2 can be obtained by the large-droplet region of the film. The electrically produced phase shift and its spatial profile controlled by the thickness of the gradient PDLC single layers of large nematic droplets can be useful for tunable spatial light modulators and other devices for active control of laser light.

Effect of short-term standard therapeutic regimens on neuropeptide Y and adipose tissue hormones in overweight insulin-resistant women with polycystic ovary syndrome.

AIM: The study was aimed at elucidating the influence of a 3-month treatment with routine therapeutic regimens--oral hormonal contraceptives (OHC) with antiandrogenic activity (a standard combination of ethynil estradiol 35 microg plus cyproterone acetate 2 mg) in combination with insulin sensitizing agents--metformin (Group I) and rosiglitazone (Group II) on adipose tissue hormones and hypothalamic neuropeptide Y (NPY) in women with polycystic ovary syndrome. PATIENTS AND METHODS: The study included 66 overweight insulin resistant women with PCOS according to the recent ESHRE-ASRM criteria randomized into 2 age-matched therapeutic groups. RESULTS: Significant decrease of leptin (P < 0.01; P = 0.001, resp.), resistin (P < 0.01; P < 0.01, resp.), tumour necrosis factor alpha (TNF alpha) (P = 0.001; P < 0.001, resp.), and NPY (P < 0.05; P < 0.001, resp.) was observed in both groups after treatment. These findings were in parallel with a significant decrease in the anthropometric parameters of body weight in the metformin group only. No significant changes in hormonal characteristics of the groups were found except for a significant decrease in androstenedione and DHEA-S (P < 0.05) in the metformin group and in 17-OH-progesterone (P < 0.05) in the rosiglitazone group. HDL-cholesterol rose and diastolic blood pressure fell significantly (P < 0.05) in the metformin group. CONCLUSION: Our data suggest beneficial effects of the treatment on potential cardiovascular risk in insulin resistant PCOS women.

Ion-implanted polymethyl methacrylate beam splitter/coupler for 1.55 microm applications.

The applicability of layers of ion-implanted polymethyl methacrylate (PMMA) for beam splitting of laser light at the telecommunications wavelength of 1.55 mum is examined. Bulk PMMA is studied, subjected to low-energy (50 keV) silicon ion implantation at various ion fluences in the range from 10(14) to 10(17) cm(-2). The formed ultrathin near-surface ion-implanted layer of a thickness of about 100 nm, buried in a depth of approximately 100 nm, can be used to split (or combine) laser beams at 1.55 microm with a low absorption loss.

The luminescence response of Eu(III)-thenoyltrifluoroacetonate complexes upon preresonant excitation with femtosecond laser pulses.

The luminescence of thenoyltrifluoroacetonate (TTA) coordination complexes of trivalent europium ion (Eu(III)) in aqueous solutions and in solid-state polymeric films is probed upon single- and two-photon preresonant excitation with Ti:sapphire femtosecond laser. Particularly, diamine-liganded Eu(III)(TTA)(3) and poly(oxyethylene phosphate)tris(beta-diketonate)Eu(III) complexes are examined aiming their possible applications as luminescent labels for sensing and imaging of biological molecules. Even at a pre-resonance, the excitation of these compounds with high-intensity, broadband light of frequency-doubled Ti:sapphire femtosecond laser centered around 400 nm results in a luminescence response suitable for fluorometric applications.

Ballistic trauma to the abdomen: shell fragments versus bullets.

Two-hundred ninety-nine patients who sustained penetrating ballistic trauma to the abdomen were divided into two groups: Group A consisted of 133 patients with shell fragment injuries from mortar artillery and Group B of 166 patients with bullet injuries from rifles and automatic or semiautomatic weapons. Both groups were analyzed retrospectively in order to compare the extent of injury and outcome. In Group A, the findings at laparotomy were negative in 15 of 133 patients (10%) compared with 9 of 166 patients (5%) in Group B (p less than 0.05). The most commonly injured abdominal organs in Group A were the colon (42%), liver (22%), small bowel (20%), stomach (14%), diaphragm (11%), spleen (10%), major vessels (40%) [corrected], and kidney (9%). The abdominal organs commonly injured in Group B were the colon (50%), small bowel (41%), liver (33%), major vessels (20%), diaphragm (17%), stomach (15%), spleen (15%), and kidney (15%). Associated extra-abdominal injuries were present in 26% of Group A patients and in 21% of Group B patients (p greater than 0.05) [corrected]. Major postoperative complications occurred in 7.5% and 8.4% of the patients in Group A and Group B, respectively (p less than 0.05). Perioperative mortality was 2.3% in Group A versus 7.2% in Group B (p less than 0.01). Our data suggest that high energy bullets to the abdomen cause higher tissue penetration and a greater blast effect than shell fragments.

Primary cancer of the liver. Evaluation, treatment, and prognosis.

Between 1970 and 1985, a diagnosis of primary hepatocellular carcinoma was established in 98 patients. Sixty-one cases developed in the presence of chronic liver disease, and only six of these were considered resectable. Of these, the median survival was 19 months. There was one perioperative death. Of the 98 tumors, 37 arose in normal livers. Of the 16 patients with tumors in normal livers that were resected, all survived operation. The long-term median survival was 32 months. Two subsets of the fibrolamellar and clear-cell variants appeared to carry a more favorable prognosis.