ICTP concentration in cervical-vaginal fluid as a potential marker of membrane collagen degradation before labor

OBJECTIVES

Numerous physical and chemical processes lead to rupture of membranes. Within the fetal membranes there are numerous types of metalloproteinases, which cause collagen type I degradation. The C-terminal telopeptide of colagen type I (ICTP) is the breakdown product of type I collagen. The aim of the study was to determine whether ICTP is secreted into the vaginal-cervical fluid (VCF) in the case of physiological rupture of the membranes of the fetus before delivery.

MATERIAL AND METHODS

The study was conducted in March 2021 at the Department of Obstetrics and Perinatology of the Jagiellonian University in Cracow, Poland. Twenty-three cases were included in the study. During routine gynecological examination with the use of specula, VCF was collected twice in a volume of 50 µL. The obtained material was then subjected to enzyme immunoassay using the Human C-telopeptide of type I collagen (ICTP) ELISA Kit (Catalog Number. CSB-E10363h). The concentration of ICTP in the sample was calibrated. The concentration range that the device can detect was 25 ng /mL-800 ng/mL.

RESULTS

The presence of ICTP in the VCF was confirmed. The minimum concentration was 43.72 ng/mL, the maximum was 762.59, in five cases the concentration was outside the maximum scale of the device.

CONCLUSIONS

ICTP was confirmed in the VCF of pregnant women before physiological delivery. Further studies are required to accurately evaluate ICTP as a marker of the processes of collagen degradation in fetal membranes in the mechanism of physiological labor and premature rupture of the membranes.

Clinical Characteristics and Predictors of In-Hospital Mortality of Patients Hospitalized with COVID-19 Infection

Background: The identification of parameters that would serve as predictors of prognosis in COVID-19 patients is very important. In this study, we assessed independent factors of in-hospital mortality of COVID-19 patients during the second wave of the pandemic. Material and methods: The study group consisted of patients admitted to two hospitals and diagnosed with COVID-19 between October 2020 and May 2021. Clinical and demographic features, the presence of comorbidities, laboratory parameters, and radiological findings at admission were recorded. The relationship of these parameters with in-hospital mortality was evaluated. Results: A total of 1040 COVID-19 patients (553 men and 487 women) qualified for the study. The in-hospital mortality rate was 26% across all patients. In multiple logistic regression analysis, age ≥ 70 years with OR = 7.8 (95% CI 3.17−19.32), p < 0.001, saturation at admission without oxygen ≤ 87% with OR = 3.6 (95% CI 1.49−8.64), p = 0.004, the presence of typical COVID-19-related lung abnormalities visualized in chest computed tomography ≥40% with OR = 2.5 (95% CI 1.05−6.23), p = 0.037, and a concomitant diagnosis of coronary artery disease with OR = 3.5 (95% CI 1.38−9.10), p = 0.009 were evaluated as independent risk factors for in-hospital mortality. Conclusion: The relationship between clinical and laboratory markers, as well as the advancement of lung involvement by typical COVID-19-related abnormalities in computed tomography of the chest, and mortality is very important for the prognosis of these patients and the determination of treatment strategies during the COVID-19 pandemic.

Determinants of the Level of Anti-SARS-CoV-2 IgG ANTibodiEs after Vaccination (DANTE-SIRIO 7) Study in a Large Cohort of Healthcare Workers

The aim of this study was to determine anti-SARS-CoV-2 IgG concentrations and their major determinants in healthcare workers (HCWs) after full vaccination with the BNT162b2 vaccine. We recruited 847 individuals vaccinated with two doses of the BNT162b2 vaccine, who completed the questionnaire, and whose antibody concentrations were tested after 3 and 6 months after full vaccination. Anti-SARS-CoV-2 IgG levels were measured on the routinely employed Siemens Atellica system. The cutoff for positivity was ≥21.8 BAU/mL. Three and 6 months after vaccination, the majority of participants were seropositive. Median concentrations of anti-SARS-CoV-2 IgG significantly decreased from 1145 BAU/mL (IQR: 543-2095) to 225 BAU/mL (IQR: 100-510). Major positive determinants of antibody levels were fever after both doses of vaccine, prior-COVID-19 exposure, and muscle pain after the first dose. Lack of symptoms after the second dose and time since vaccination were significant negative determinants of anti-SARS-CoV-2 IgG concentrations. No other factors, including age and gender, or underlying comorbidities had a significant effect on antibody levels in HCWs. The anti-SARS-CoV-2 response after two doses of BNT162b2 vaccine was independently associated with prior-COVID-19 exposure, time since vaccination, and the occurrence of symptoms after either dose of vaccine. Easily reportable adverse reactions may facilitate the identification of immune response in HCWs.

Searching for better X-ray and γ-ray photodetectors: structure-composition properties of the TlPb2Br5-x I x quaternary system

Developing X-ray and γ-ray detectors with stable operation at ambient temperature and high energy resolution is an open challenge. Here, we present an approach to search for new detector materials, combining binary photodetector compounds. More specifically, we explore quaternary TlPb₂Br_5-x I _x compositions, relying on materials synergy between TlBr, TlI, and PbI₂ photodetectors. We discover a broad solid solution in the TlPb₂Br₅-'TlPb₂I₅' section, which can be derived from a new quaternary compound, TlPb₂BrI₄, by partial substitution of Br by I atoms on the 4c site or by replacement of I by Br atoms on the 16l site. We carry out a thorough crystallographic analysis of the new TlPb₂BrI₄ compound and prepare a high-quality standardized structure file. We also complete the phase diagram of the TlPb₂Br₅-'TlPb₂I₅' section, based on 21 alloys. Furthermore, we synthesize a series of high quality centimeter-sized TlPb₂Br_5-x I _x single crystals (x = 2, 2.5, 3, 3.5, 4, 4.5) by the Bridgman-Stockbarger method and study their structure and properties using a combination of experimental techniques (X-ray diffraction, X-ray photoelectron spectroscopy, and absorption spectroscopy) and theoretical calculations.

Electron, phonon and thermoelectric properties of Cu7PS6 crystal calculated at DFT level

The promising class of the environment-friendly thermoelectrics is the copper-based argyrodite-type ion-conducting crystals exhibiting just extraordinary low thermal conductivity below the glass limit associated with the molten copper sublattice leading to a softening of phonon modes. To explain why the argyrodite structure containing copper ions favors the low thermal conductivity, we have utilized the ab initio calculations of the electron, phonon, and thermoelectric properties of Cu₇PS₆ crystal in the framework of the density functional and Boltzmann transport theories. To obtain the reliable thermoelectric properties of Cu₇PS₆, we take into account the dependence of the electron effective mass m^* on the redundant carrier concentration n. We propose to use the Burstein–Moss effect for the calculation of the electron effective mass m^* of a semiconductor. We have found the strong nonlinear character of copper atom vibrations in Cu₇PS₆ which exceeds substantially the similar values for phosphorous and sulfur atoms. The large vibration nonlinearity of the copper atoms found in Cu₇PS₆ explains the diffusion-like heat transfer and the relatively low coefficient of the lattice thermal conductivity (κ = 0.7 W/(m K)), which is favorable to achieve the large thermoelectric figure of merit.

Clinical significance of asymptomatic [i]Clostridium difficile[/i] colonisation in patients undergoing antibiotic treatment

BACKGROUND

[i]Clostridium difficile[/i] infections become a serious problem in terms of nosocomial infections, as well as a consequence of common use of antibiotics.

AIM

The aim of the study was to evaluate [i]Clostridium difficile[/i] carriage in patients admitted to the Clinical Department of Infectious Diseases and Hepatology without acute or chronic diarrhea and to assess the impact of antibiotic treatment on the development of enteritis in hospital. Other factors that may affect the risk of infection were also analyzed.

RESULTS

Fourteen patients (14%) were carriers of [i]Clostridium difficile[/i] at admission. Second assessment taken after fourteen days of antibiotic treatment showed decrease in GDH antigen prevalence to eight subjects (12.1%). Three patients (3%) had diarrhea during hospitalization, and the toxins A and/or B were found in them.

CONCLUSIONS

The frequency of [i]Clostridium difficile[/i] carriage among adults in Poland may be underestimated. Screening for Clostridium difficile GDH antigen may be useful although do not provide definite prognosis of symptomatic disease during ceftriaxone treatment. The risk of Clostridium difficile infection may be reduced mainly by rationalizing antibiotic therapy and following appropriate procedures.

Low risk of HBV reactivation in a large European cohort of HCV/HBV coinfected patients treated with DAA

OBJECTIVES

The aim of the study was to analyze the prevalence and clinical characteristics of HCV/HBV coinfection and to evaluate the rate of HBV-reactivation during anti-HCV therapy in a large real-world study.

METHODS

Analyzed population consisted of 10,152 chronic hepatitis C patients treated with DAA between 2015 and 2019 in a nationwide study. Prior to the DAA all subjects had HBsAg and 60% anti-HBc testing.

RESULTS

111 of 10,152 patients (1.1%) had detectable HBsAg and 1239 of 6139 (20.2%) anti-HBcAb. The prevalence of occult hepatitis B was 0.48%. HCV/HBV patients were younger with a higher proportion of males, HIV-coinfected, and advanced fibrosis. They were less often diagnosed with diabetes but more often with chronic kidney disease. In HBsAg(+) subjects with baseline HBV-DNA available 6/102 (5.9%) HBV-reactivations during or after DAA therapy were observed, and in two (1.9%) significant hepatic flares were noted. In HBsAg(-)/anti-HBc(+) group 2 (0.16%) reactivations were observed only in patients undergoing immunosuppressive therapy.

DISCUSSION

Data from a large European cohort suggest a relatively low risk of HBV-reactivation during DAA-therapy for HCV infection in HBsAg(+) patients. In HBsAg(-)/anti-HBc(+) HBV-reactivation seems to be limited to subjects with immunodeficiency. Importantly, previous exposure to HBV and occult hepatitis B is present in a significant proportion of HCV-infected.

Actinomycosis - a forgotten chronic infectious disease - case report series

Actinomycosis is one of the greatest 'chameleons' among infectious diseases. It may imitate inflammation, abscess or a neoplasmatic tumor. Moreover, correct diagnosis is even more challenging due to the fact that the disease takes on various forms like: cervicocephalic, abdominal, or affects the reproductive organs. In order to highlight the diagnostic difficulties of actinomycosis, we have decided to describe six cases of female patients (aged 31-73 years, mean age: 52 years) hospitalized due to actinomycosis in the Department of Infectious Diseases and Hepatology between 2014-2019. Additionally, a case of one patient was described in detail as the course of her disease was exceptionally non-specific. Only in 2 of 6 patients the primary diagnosis was correct. The four other patients were initially suspected with cancer or inflammation. Three of the patients were diagnosed with the abdominal form of actinomycosis, one - neck and head, and one presented both locations. Only histopathological examinations during invasive procedures allowed to state the final diagnosis. An adequate diagnosis was associated with a number of additional tests and delayed appropriate treatment. WBC and CRP were within normal range in all patients. Four patients completed treatment successfully after 60-192 days, one is still on therapy and one is lost to follow-up. In conclusion, common features of actinomycosis presented in this case series include predominance of female gender, abdominal localization and lack of typical symptoms. What is more, therapy with antibiotics, mainly doxycycline and beta-lactams resulted in complete regression of lesions in the majority of cases. Given the examples of our patients we believe that actinomycosis should be considered in the differential diagnosis of all abdominal tumors, especially in women. Abbreviations: WBC - white blood cells, CRP - C-reactive protein, CT - computed tomography, IUD - Intra-Uterine Device, i.v. - intravenous.

Long-Term Endurance and Power Training May Facilitate Motor Unit Size Expansion to Compensate for Declining Motor Unit Numbers in Older Age

The evidence concerning the effects of exercise in older age on motor unit (MU) numbers, muscle fiber denervation and reinnervation cycles is inconclusive and it remains unknown whether any effects are dependent on the type of exercise undertaken or are localized to highly used muscles. MU characteristics of the vastus lateralis (VL) were assessed using surface and intramuscular electromyography in eighty-five participants, divided into sub groups based on age (young, old) and athletic discipline (control, endurance, power). In a separate study of the biceps brachii (BB), the same characteristics were compared in the favored and non-favored arms in eleven masters tennis players. Muscle size was assessed using MRI and ultrasound. In the VL, the CSA was greater in young compared to old, and power athletes had the largest CSA within their age groups. Motor unit potential (MUP) size was larger in all old compared to young (p < 0.001), with interaction contrasts showing this age-related difference was greater for endurance and power athletes than controls, and MUP size was greater in old athletes compared to old controls. In the BB, thickness did not differ between favored and non-favored arms (p = 0.575), but MUP size was larger in the favored arm (p < 0.001). Long-term athletic training does not prevent age-related loss of muscle size in the VL or BB, regardless of athletic discipline, but may facilitate more successful axonal sprouting and reinnervation of denervated fibers. These effects may be localized to muscles most involved in the exercise.

The age-related loss of skeletal muscle mass and function: Measurement and physiology of muscle fibre atrophy and muscle fibre loss in humans

•

Loss of muscle mass with age is due to atrophy and loss of individual muscle fibres.

•

Anabolic resistance is fundamental in age-related fibre atrophy.

•

Fibre loss is associated with denervation and remodelling of motor units.

•

The plasticity of both factors should be considered in future research.

Age-related loss of skeletal muscle mass and function, sarcopenia, is associated with physical frailty and increased risk of morbidity (chronic diseases), in addition to all-cause mortality. The loss of muscle mass occurs incipiently from middle-age (∼1%/year), and in severe instances can lead to a loss of ∼50% by the 8–9th decade of life. This review will focus on muscle deterioration with ageing and highlight the two underpinning mechanisms regulating declines in muscle mass and function: muscle fibre atrophy and muscle fibre loss (hypoplasia) – and their measurement. The mechanisms of muscle fibre atrophy in humans relate to imbalances in muscle protein synthesis (MPS) and breakdown (MPB); however, since there is limited evidence for basal alterations in muscle protein turnover, it would appear that “anabolic resistance” to fundamental environmental cues regulating diurnal muscle homeostasis (namely physical activity and nutrition), underlie age-related catabolic perturbations in muscle proteostasis. While the ‘upstream’ drivers of the desensitization of aged muscle to anabolic stimuli are poorly defined, they most likely relate to impaired efficiency of the conversion of nutritional/exercise stimuli into signalling impacting mRNA translation and proteolysis. Additionally, loss of muscle fibres has been shown in cadaveric studies using anatomical fibre counts, and from iEMG studies demonstrating motor unit loss, albeit with few molecular investigations of this in humans. We suggest that defining countermeasures against sarcopenia requires improved understandings of the co-ordinated regulation of muscle fibre atrophy and fibre loss, which are likely to be inextricably linked.

Assessment of the implementation of the infectious diseases screening programmes among pregnant women in the Lesser Poland region and comparison with similar programmes conducted in other European Union countries

OBJECTIVES

The aim of the study was to assess the level of implementation of recommendations of the Ministry of Health regarding infectious disease screening during pregnancy.

MATERIAL AND METHODS

The study included 477 patients who were admitted to the delivery room between December 2015 and February 2016. Data on screening test results were collected based on medical records covering the period before the admission.

RESULTS

The Human Immunodeficiency Virus (HIV) screening was conducted in 410 (86%). 460 (96%) of patients were screened for Hepatitis B Virus (HBV) and 427 (89.5%) for Hepatitis C Virus (HCV). Syphilis screening covered 465 (97.5%) of patients. Immunoglobulin M (IgM) titer against Rubella Virus (RV) was assessed in 218 (45%) patients and immunoglobulin G (IgG) in 319 (66.9%). Screening for Toxoplasma gondii based on assessment of IgM titer was conducted in 440 (92%) patients while IgG titter was assessed in 413 (86.6%). 343 (71.9%) patients had obtained vaginal swabs for Group B Streptococci (GBS) while the anal swabs were taken only from 268 (56.2%) patients.

CONCLUSIONS

Coverage of screening for syphilis and HBV was similar to the countries with highest prevalence of conducting such screening, on the other hand RV screening place as among countries with lowest prevalence. There is an increasing trend in conducting HIV screening. Screening for HCV and toxoplasmosis is at satisfactory level and Poland is one of a few European countries offering such screening. The screening for GBS is insufficient which result in excessive use of intrapartum antibiotic prophylaxis.

Failure to expand the motor unit size to compensate for declining motor unit numbers distinguishes sarcopenic from non-sarcopenic older men

Key points

The age‐related loss of muscle mass is related to the loss of innervating motor neurons and denervation of muscle fibres.

Not all denervated muscle fibres are degraded; some may be reinnervated by an adjacent surviving neuron, which expands the innervating motor unit proportional to the numbers of fibres rescued.

Enlarged motor units have larger motor unit potentials when measured using electrophysiological techniques.

We recorded much larger motor unit potentials in relatively healthy older men compared to young men, but the older men with the smallest muscles (sarcopenia) had smaller motor unit potentials than healthy older men.

These findings suggest that healthy older men reinnervate large numbers of muscle fibres to compensate for declining motor neuron numbers, but a failure to do so contributes to muscle loss in sarcopenic men.

Abstract

Sarcopenia results from the progressive loss of skeletal muscle mass and reduced function in older age. It is likely to be associated with the well‐documented reduction of motor unit numbers innervating limb muscles and the increase in size of surviving motor units via reinnervation of denervated fibres. However, no evidence exists to confirm the extent of motor unit remodelling in sarcopenic individuals. The aim of the present study was to compare motor unit size and number between young (n = 48), non‐sarcopenic old (n = 13), pre‐sarcopenic (n = 53) and sarcopenic (n = 29) men. Motor unit potentials (MUPs) were isolated from intramuscular and surface EMG recordings. The motor unit numbers were reduced in all groups of old compared with young men (all P < 0.001). MUPs were higher in non‐sarcopenic and pre‐sarcopenic men compared with young men (P = 0.039 and 0.001 respectively), but not in the vastus lateralis of sarcopenic old (P = 0.485). The results suggest that extensive motor unit remodelling occurs relatively early during ageing, exceeds the loss of muscle mass and precedes sarcopenia. Reinnervation of denervated muscle fibres probably expands the motor unit size in the non‐sarcopenic and pre‐sarcopenic old, but not in the sarcopenic old. These findings suggest that a failure to expand the motor unit size distinguishes sarcopenic from pre‐sarcopenic muscles.

The age‐related loss of muscle mass is related to the loss of innervating motor neurons and denervation of muscle fibres.

Not all denervated muscle fibres are degraded; some may be reinnervated by an adjacent surviving neuron, which expands the innervating motor unit proportional to the numbers of fibres rescued.

Enlarged motor units have larger motor unit potentials when measured using electrophysiological techniques.

We recorded much larger motor unit potentials in relatively healthy older men compared to young men, but the older men with the smallest muscles (sarcopenia) had smaller motor unit potentials than healthy older men.

These findings suggest that healthy older men reinnervate large numbers of muscle fibres to compensate for declining motor neuron numbers, but a failure to do so contributes to muscle loss in sarcopenic men.

Hip and spine bone mineral density are greater in master sprinters, but not endurance runners compared with non-athletic controls

We examined bone density in older athletes and controls. Sprinters had greater hip and spine bone density than endurance athletes and controls, whereas values were similar in the latter two groups. These results could not be explained by differences in impact, muscle size or power between sprint and endurance athletes.

PURPOSE

We examined the relationship between prolonged participation in regular sprint or endurance running and skeletal health at key clinical sites in older age, and the factors responsible for any associations which we observed.

METHODS

We recruited 38 master sprint runners (28 males, 10 females, mean age 71 ± 7 years), 149 master endurance runners (111 males, 38 females, mean age 70 ± 6 years) and 59 non-athletic controls (29 males, 30 females, mean age 74 ± 5 years). Dual X-ray absorptiometry was used to assess hip and spine bone mineral density (BMD), body composition (lean and fat mass), whilst jump power was assessed with jumping mechanography. In athletes, vertical impacts were recorded over 7 days from a waist-worn accelerometer, and details of starting age, age-graded performance and training hours were recorded.

RESULTS

In ANOVA models adjusted for sex, age, height, body composition, and jump power, sprinter hip BMD was 10 and 14% greater than that of endurance runners and controls respectively. Sprinter spine BMD was also greater than that of both endurance runners and controls. There were no differences in hip or spine BMD between endurance runners and controls. Stepwise regression showed only discipline (sprint/endurance), sex, and age as predictors of athlete spine BMD, whilst these variables and starting age were predictive of hip BMD.

CONCLUSIONS

Regular running is associated with greater BMD at the fracture-prone hip and spine sites in master sprinters but not endurance runners. These benefits cannot be explained by indicators of mechanical loading measured in this study including vertical impacts, body composition or muscular output.

Ionicity and birefringence of α-LiNH4SO4crystals: ab initio DFT study, X-ray spectroscopy measurements

The structural, electronic properties and ionicity of the α-LiNH₄SO₄dielectric crystals are examined using a complex approach: experimental studies of X-ray spectroscopy and the first principles band structure techniques within a framework of DFT.

Improving green emission of Tb3+ ions in BaO-B2 O3 -P2 O5 glasses by means of Al3+ ions

BaO-B₂ O₃ -P₂ O₅ glasses doped with a fixed concentration of Tb³⁺ ions and varying concentrations of Al₂ O₃ were synthesized, and the influence of the Al³⁺ ion concentration on the luminescence efficiency of the green emission of Tb³⁺ ions was investigated. The optical absorption, excitation, luminescence spectra and fluorescence decay curves of these glasses were recorded at ambient temperature. The emission spectra of terbium ions when excited at 393 nm exhibited two main groups of bands, corresponding to ⁵ D₃  → ⁷ F_j (blue region) and ⁵ D₄  → 7F_j (green region). From these spectra, the radiative parameters, viz., spontaneous emission probability A, total emission probability A_T , radiative lifetime τ and fluorescent branching ratio β, of different transitions originating from the ⁵ D₄ level of Tb³⁺ ions were evaluated based on the Judd-Ofelt theory. A clear increase in the quantum efficiency and luminescence of the green emission of Tb³⁺ ions corresponding to ⁵ D₄  → ⁷ F₅ transition is observed with increases in the concentration of Al₂ O₃ up to 3.0 mol%. The improvement in emission is attributed to the de-clustering of terbium ions by Al³⁺ ions and also to the possible admixing of wave functions of opposite parities. Copyright © 2016 John Wiley & Sons, Ltd.

Synthesis and structure of novel Ag2Ga2SiSe6 crystals: promising materials for dynamic holographic image recording

Phase diagrams of the AgGaSe₂–SiSe₂ system were explored by differential thermal analysis (DTA) and X-ray diffraction (XRD) analysis methods for the first time.

Age-related neuromuscular changes affecting human vastus lateralis

KEY POINTS

Skeletal muscle size and strength decline in older age. The vastus lateralis, a large thigh muscle, undergoes extensive neuromuscular remodelling in healthy ageing, as characterized by a loss of motor neurons, enlargement of surviving motor units and instability of neuromuscular junction transmission. The loss of motor axons and changes to motor unit potential transmission precede a clinically-relevant loss of muscle mass and function.

ABSTRACT

The anterior thigh muscles are particularly susceptible to muscle loss and weakness during ageing, although how this is associated with changes to neuromuscular structure and function in terms of motor unit (MU) number, size and MU potential (MUP) stability remains unclear. Intramuscular (I.M.) and surface electromyographic signals were recorded from the vastus lateralis (VL) during voluntary contractions held at 25% maximal knee extensor strength in 22 young (mean ± SD, 25.3 ± 4.8 years) and 20 physically active older men (71.4 ± 6.2 years). MUP size, firing rates, phases, turns and near fibre (NF) jiggle were determined and MU number estimates (MUNEs) were made by comparing average surface MUP with maximal electrically-evoked compound muscle action potentials. Quadriceps cross-sectional area was measured by magnetic resonance imaging. In total, 379 individual MUs were sampled in younger men and 346 in older men. Compared to the MU in younger participants, those in older participants had 8% lower firing rates and larger MUP size (+25%), as well as increased complexity, as indicated by phases (+13%), turns (+20%) and NF jiggle (+11%) (all P < 0.0005). The MUNE values (derived from the area of muscle in range of the surface-electrode) in older participants were ∼70% of those in the young (P < 0.05). Taking into consideration the 30% smaller cross-sectional area of the VL, the total number of MUs in the older muscles was between 50% and 60% lower compared to in young muscles (P < 0.0005). A large portion of the VL MU pool is lost in older men and those recruited during moderate intensity contractions were enlarged and less stable. These MU changes were evident before clinically relevant changes to muscle function were apparent; nevertheless, the changes in MU number and size are probably a prelude to future movement problems.

IR laser induced spectra in novel crystals CdTe-CuInTe2

The novel crystalline alloys CdTe-CuInTe2 were synthesized. The photoinduced spectral changes of the anharmonic phonon modes were explored by cw CO2 laser at power about 2 kW in the vicinity of the 1650 cm(-1) mode. The changes of the intensities for principal phonon modes were found. These modes were assigned both to harmonic as well as anharmonic modes. All the measurements are studied after the Ir illumination. The performed quantum chemical calculations with application of the norm-conserving pseudopotential method and Green functions allow to identify the origin of the content dependent anharmonic phonon modes. Some correlation between the intensities of the corresponding phonon modes at about 1600-1700 cm(-1) and the corresponding IR induced changes were found.

Absorption and photoconductivity spectra of Ag₂GeS₃ crystal: experiment and theory

Spectral features of polycrystalline Ag(2)GeS(3) samples synthesized from high-purity elements (at least 99.99 wt.% purity) in quartz ampoules evacuated to 0.1 Pa were explored. The band energy gap of Ag(2)GeS(3) crystals estimated from the fundamental absorption edge and photoconductivity spectra were found to be equal to 1.98 eV and 2.16 eV, respectively. Simultaneously we have performed calculations of the band structure, total and partial density of states and the electron charge density using the ab initio FP-LAPW method. All the calculations were performed with four different exchange-correlation (xc) potentials. It was found that the effect of using different xc is very marginal on the valence band maximum (VBM) while it is dramatically shifted the conduction band minimum (CBM) towards higher energies with respect to the Fermi energy position. Our theoretical results have given a band energy gap equal to 0.40 eV (for LDA), 0.42 eV (GGA), 1.03 eV (EVGGA) and 1.30 eV (mBJ) xc potentials. Thus the underestimation of the energy gap in LDA and GGA was partially corrected in EVGGA and mBJ model. As a remarkable fact mBJ did not bring the energy band gap very close to the experimental once. We have discovered that the Ag-s states have only a small effect on the conduction bands shifts whereas Ge-s states have a strong effect in extending of the gap, while remaining the valence bands unchanged.

Optical and photoconductivity spectra of novel Ag₂In₂SiS₆ and Ag₂In₂GeS₆ chalcogenide crystals

Complex spectral studies of near-band gap and photoconductive spectra for novel Ag(2)In(2)SiS(6) and Ag(2)In(2)GeS(6) single crystals are presented. The spectral dependences of photoconductivity clearly show an existence of spectral maxima within the 450 nm-540 nm and 780 nm-920 nm. The fundamental absorption edge is analyzed by Urbach rule. The origin of the spectral photoconductivity spectral maxima is discussed. Temperature dependences of the spectra were done. The obtained spectral features allow to propose the titled crystals as photosensors. An analysis of the absorption and photoconductivity spectra is given within a framework of oversimplified spectroscopic model of complex chalcogenide crystals.

Structural investigations on PbO-Sb(2)O(3)-B(2)O(3):CoO glass ceramics by means of spectroscopic and dielectric studies

PbO-Sb(2)O(3)-B(2)O(3) glasses mixed with different concentrations of CoO (ranging from 0 to 2.0 mol%) were crystallized. The samples were characterized by x-ray diffraction, scanning electron microscopy and differential scanning calorimetric techniques. The x-ray diffraction and scanning electron microscopic studies have revealed the presence of CoSb(2)O(6), Co(2.33)Sb(0.67)O(4), Pb(5)Sb(2)O(8),Pb(3)(SbO(4))(2), PbB(4)O(7) and Co(3)O(4) crystalline phases in these samples. The DSC studies have indicated the spreading of the crystallization from the inside to the surface of the samples as the concentration of the crystallizing agent is increased. The IR and Raman spectroscopic studies have pointed out the existence of conventional BO(3), BO(4), SbO(4) and also Co(III)-O structural units in the glass ceramic samples. These studies have further indicated the decreasing concentration of symmetrical structural vibrational groups with increase in the concentration of CoO. The results of various studies, namely dielectric properties over a range of frequency and temperature, photo-induced birefringence, optical absorption, fluorescence and magnetic susceptibility at room temperature of PbO-Sb(2)O(3)-B(2)O(3):CoO glass ceramics, have also been reported. The variations observed as a function of the concentration of crystallizing agent in all these properties have been analyzed in the light of different oxidation states and environments of cobalt ions in the glass ceramic network.

Second order optical effects in Au nanoparticle-deposited ZnO nanocrystallite films

Photoinduced second harmonic generation (SHG) in Au nanoparticle-deposited ZnO nanocrystallite (NC) films was explored by applying bicolor coherent treatment of a Nd-YAG laser with wavelength 1.06 µm and its SHG. We have established that coexistence of the ZnO and Au nanoparticles gives a substantially larger SHG output with respect to pure ZnO NC deposited on the glass substrate. It was established that the value of the second order susceptibility is about 23 pm V(-1). Better nonlinear optical susceptibilities were obtained during phototreatment at temperatures near 30-35 °C for the Au doped samples. The samples without gold NCs are temperature independent. Generally an increasing temperature leads to a decrease of the optical SHG.

Biosynthesis of gibberellic acid (GA3) and mycotoxins by F. moniliforme sheldon and other species of Liseola section

F. moniliforme and other species of Liseola section, F. culmorum, F. dlamini, and F. nygamai, were examined for their ability to produce gibberellic acid (GA3), fumonisins, trichothecenes, zearalenone, moniliformin, and bikaverin (TLC method). Gibberellic acid was produced by F. moniliforme strains in liquid medium and on rice kernels with a maximum concentration level of 470 mg/dm3 and 1 g/kg, respectively. No strain isolated in Poland produced GA3. High-yielding gibberellic acid strains produced neither trichothecenes and fumonisins nor other tested compounds. Also the rest of strains of examined species did not produce trichothecenes and other mycotoxins except for fumonisins which were found in rice cultures of F. moniliforme, F. proliferatum, and F. subglutinans. Bikaverin was produced by F. moniliforme always together with fumonisins. Filtrates of liquid cultures of gibberellin producing strains were tested for their toxicity to brine shrimps larvae (Artemia salina). It was found that GA3 presence does not increase toxicity of these filtrates.

Acute effects of the selective cholinergic channel activator (nicotinic agonist) ABT-418 in Alzheimer's disease

To explore further the potential for cognitive enhancement utilizing nicotinic stimulation in Alzheimer's disease (AD), six otherwise healthy subjects with moderate AD received placebo and three doses (6, 12, and 23 mg) of the novel selective cholinergic channel activator (ChCA) (nicotinic agonist) ABT-418 over 6 h in a double-blind, within-subjects, repeated-measures design. Subjects showed significant improvements in total recall and a decline in recall failure on a verbal learning task. Qualitatively similar improvements were seen in non-verbal learning tasks such as spatial learning and memory, and repeated acquisition. No significant behavioral, vital sign, or physical side effects were seen. These results confirm that stimulating central nicotinic receptors has acute cognitive benefit in AD patients. These findings suggest that selective ChCAs have a potential therapeutic role in dementing disorders, and that further studies with this or similar agents in AD and/or Parkinson's disease are warranted.

Age and management team performance

One hundred eighty male managers participated as age-homogeneous 4-person teams in a validated all-day decision-making simulation. Fifteen teams consisted of 28- to 35-year-old participants (young), 15 teams were in the 45-55 age range (middle-aged), and 15 teams consisted of 65- to 75-year-old (older) persons. More than 40 objective performance measures (loading on 12-15 factors) were calculated on the basis of team decision making, planning, and other indicators. Performance by young and middle-aged teams was generally similar. Older teams made fewer decisions and were less strategic and less responsive to incoming information. Their overview of the task was less broad; action diversity and information search was reduced. However, older teams used opportunities and handled a simulated emergency as effectively as their younger and middle-aged counterparts. Alternative explanations for the obtained differences are presented.

Effects of beta blockade with metoprolol on simple and complex task performance

The effect of treatment with the beta-blocker metoprolol on several indicants of task performance was investigated. Twenty-five male hypertensives were treated for 2 weeks each with drug and placebo in a double-blind crossover design. Comparisons to 25 matched untreated normotensives were made. Participants responded twice to a Mood Adjective Check List (MACL) and the Stroop Color-Word Test. In addition, they participated in two parallel decision-making simulations. Normotensives and hypertensives on drug or placebo did not differ on MACL and Stroop scores. Comparisons on 12 validated simulation measures showed that drug treatment with metoprolol aided complex task performance. Drug treatment improved strategic capacity and the ability to deal effectively with emergencies. Preliminary evidence that treatment with metoprolol might help restore performance capacity that may have been lost due to hypertensive disease was also obtained.

Impact of beta-blockade on complex cognitive functioning

Fifty adult men with mild to moderate hypertension were recruited to participate in a double-blind crossover study. Each subject received 14 days of drug treatment and 14 days of placebo treatment (random order). Half the subjects were assigned to a metoprolol (150 mg/day) vs placebo treatment regimen and half to an atenolol (100 mg/day) vs placebo regimen. Blood pressure levels as well as measures of simple (proofreading), intermediate (visual-motor task), and complex (management simulation) task performance were obtained at the end of the drug and placebo treatment periods. Metoprolol treatment generated better scores than did placebo or atenolol treatment for proofreading, visual-motor performance, and several measures of complex managerial competence. Atenolol treatment generally resulted in performance levels that did not differ from those observed with placebo. However, atenolol-treated subjects made more errors than did placebo-treated subjects in the visual-motor task and also showed some deterioration on one measure of complex managerial functioning.

[Experiences with processing control in the radiology department of a large municipal hospital]

Processing control is an important part of quality control in X-ray diagnostics. From 1 July 1984 to 31 December 1985 the processing of 10 of the 11 processors in the Radiology Department at the Augsburg Municipal Hospital was controlled regularly on a total of 304 days. The speed index was at 95.8%, the contrast index at 96.1% within the limits recommended by the Federal German DIN standard. Processing control has proved meaningful and effective in keeping processing on a constant level. It also indicates where to look for the reasons for poor image quality. It takes less than 5 minutes to carry out the processing control of one processor. Processing control is a task of the radiographer.