Using of sonochemically prepared SbSI for electrospun nanofibers.

A novel polymeric, polyacrylonitrile (PAN) nanofibers containing ferroelectric and semiconducting antimony sulfoiodide (SbSI) have been made by electrospinning. SbSI nanowires, used as the filler, have been prepared sonochemically from antimony sulphide (Sb2S3) and antimony tri-iodide (SbI3) for the first time. Nanocrystalline SbSI has been fabricated in ethanol under ultrasonic irradiation (20kHz, 565W/cm2) at 323K within 2h. The products have been characterized by using techniques such as powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, high-resolution transmission electron microscopy, selected area electron diffraction and optical diffuse reflection as well as transmission spectroscopy. The good quality of the nanocrystals and their dispersion in the nanofiber's volume is important because this material is attractive for nanogenerators due to its ferroelectric and piezoelectric properties. The amplitude of the voltage pulse, generated under shock pressure of 3.0MPa, has reached 180V in the prototype PAN/SbSI piezoelectric nanogenerator. The peak output voltage of about 0.2V was measured in bending/releasing conditions with the deformation frequency of 1Hz.

Optimization of data analysis for the in vivo neutron activation analysis of aluminum in bone.

An existing system at McMaster University has been used for the in vivo measurement of aluminum in human bone. Precise and detailed analysis approaches are necessary to determine the aluminum concentration because of the low levels of aluminum found in the bone and the challenges associated with its detection. Phantoms resembling the composition of the human hand with varying concentrations of aluminum were made for testing the system prior to the application to human studies. A spectral decomposition model and a photopeak fitting model involving the inverse-variance weighted mean and a time-dependent analysis were explored to analyze the results and determine the model with the best performance and lowest minimum detection limit. The results showed that the spectral decomposition and the photopeak fitting model with the inverse-variance weighted mean both provided better results compared to the other methods tested. The spectral decomposition method resulted in a marginally lower detection limit (5µg Al/g Ca) compared to the inverse-variance weighted mean (5.2µg Al/g Ca), rendering both equally applicable to human measurements.

Measurements of neutron energy spectra from 7Li(p,n)7Be reaction with Bonner sphere spectrometer, Nested Neutron Spectrometer and ROSPEC.

Neutron spectrometry measurements were carried out at the McMaster Accelerator Laboratory (MAL), which is equipped with a 3-MV Van de Graaff-type accelerator. Protons were accelerated onto a thick natural lithium target inducing the (7)Li(p,n)(7)Be threshold reaction. Depending on the proton energy, slightly different poly-energetic neutron fields were produced. Neutron spectra were measured at two incident proton energies: 2.15 and 2.24 MeV, which produced poly-energetic neutrons with maximum kinetic energies of 401 and 511 keV, respectively. Measurements were performed at a distance of 1.5 m from the target in the forward direction with three different instruments: Bonner sphere spectrometer, Nested Neutron Spectrometer and ROtational proton recoil SPECtrometer.

Neutron spectrometry and dosimetry study at two research nuclear reactors using Bonner sphere spectrometer (BSS), rotational spectrometer (ROSPEC) and cylindrical nested neutron spectrometer (NNS).

Neutron spectrometry and subsequent dosimetry measurements were undertaken at the McMaster Nuclear Reactor (MNR) and AECL Chalk River National Research Universal (NRU) Reactor. The instruments used were a Bonner sphere spectrometer (BSS), a cylindrical nested neutron spectrometer (NNS) and a commercially available rotational proton recoil spectrometer. The purposes of these measurements were to: (1) compare the results obtained by three different neutron measuring instruments and (2) quantify neutron fields of interest. The results showed vastly different neutron spectral shapes for the two different reactors. This is not surprising, considering the type of the reactors and the locations where the measurements were performed. MNR is a heavily shielded light water moderated reactor, while NRU is a heavy water moderated reactor. The measurements at MNR were taken at the base of the reactor pool, where a large amount of water and concrete shielding is present, while measurements at NRU were taken at the top of the reactor (TOR) plate, where there is only heavy water and steel between the reactor core and the measuring instrument. As a result, a large component of the thermal neutron fluence was measured at MNR, while a negligible amount of thermal neutrons was measured at NRU. The neutron ambient dose rates at NRU TOR were measured to be between 0.03 and 0.06 mSv h⁻¹, while at MNR, these values were between 0.07 and 2.8 mSv h⁻¹ inside the beam port and <0.2 mSv h⁻¹ between two operating beam ports. The conservative uncertainty of these values is 15 %. The conservative uncertainty of the measured integral neutron fluence is 5 %. It was also found that BSS over-responded slightly due to a non-calibrated response matrix.

DOSIMETRIC response of a REM-500 in low energy neutron fields typical of nuclear power plants.

This study investigates the response of a REM-500 to assess neutron quality factor and dose equivalent in low energy neutron fields, which are commonly encountered in the workplace environment of nuclear power stations. The McMaster University 3 MV Van de Graaff accelerator facility was used to measure the response of the instrument in monoenergetic neutron fields in the energy range 51 to 727 keV by bombarding a thin LiF target with 1.93-2.50 MeV protons. The energy distribution of the neutron fields produced in the facility was measured by a (3)He filled gas ionization chamber. The MCA mode of the REM-500 instrument was used to collect lineal energy distributions at varying neutron energies and to calculate the frequency and dose-mean lineal energies. The effective quality factor, Q-, was also calculated using the values of Q(y)listed in the REM-500 operation manual and compared with those of ICRP 60. The authors observed a continuously increasing trend in y - F, y-D, and Q-with an increase in neutron energy. It is interesting to note that standard tissue equivalent proportional counters (TEPCs) filled with tissue equivalent(TE) gas give rise to a similar trend for these microdosimetric quantities of interest in the same energy range; however, the averages calculated in this study are larger by about 15%compared to a TEPC filled with propane-based TE gas probably because of the larger stopping power of protons in propane compared to TE gas. These somewhat larger event sizes did not result in any significant increase in the Q-compared to those obtained from a TEPC filled with TE gas and were found to be in good agreement with other measurements reported earlier at corresponding neutron energies. The instrument quality factor response, R(Q), defined as the ratio of measured quality factor to the calculated quality factor in an ICRU tissue sphere,was found to vary with neutron energy. The instrument response,R(Q), was ~0.6 at 727 keV, which deteriorates further to ~0.3 at 51 keV neutron energy. The counter response based on ICRP 60 was comparable to an ideal response of 1.0 above 600 keV, which dropped to ~0.8 at 159 keV and ~0.4 at 51 keV neutron energy. The decline in counter quality factor response based on ICRP 60 was found to be much steeper than that when using the instrument's built-in function for quality factor.The REM-500 measures a dose equivalent at 727 keV,which is 60% of the ambient dose equivalent, 40% at 159 keV,and 15% at 51 keV. Two algorithms have been developed, one for real time measurement and another to be used post measurement,and their efficacy is demonstrated in determining the quality factor and the ambient dose equivalent in low energy neutron fields, which are typical for the workplace environment in CANDU® nuclear power generating stations.

Dosimetric characterization of the irradiation cavity for accelerator-based in vivo neutron activation analysis.

A neutron irradiation cavity for in vivo activation analysis has been characterized to estimate its dosimetric specifications. The cavity is defined to confine irradiation to the hand and modifies the neutron spectrum produced by a low energy accelerator neutron source to optimize activation per dose. Neutron and gamma-ray dose rates were measured with the microdosimetric technique using a tissue-equivalent proportional counter at the hand irradiation site and inside the hand access hole. For the outside of the cavity, a spherical neutron dose equivalent meter and a Farmer dosemeter were employed instead due to the low intensity of the radiation field. The maximum dose equivalent rate at the outside of the cavity was 2.94 microSv/100 microA min, which is lower by a factor of 1/2260 than the dose rate at the hand irradiation position. The local dose contributions from a hand, an arm and the rest of a body to the effective dose rate were estimated to be 1.73, 0.782 and 2.94 microSv/100 microA min, respectively. For the standard irradiation protocol of the in vivo hand activation, 300 microA min, an effective dose of 16.3 microSv would be delivered.

[Levels of CEA, antibodies against mycobacterial antigens and ACE activity in serum and in BALF in patients with sarcoidosis, tuberculosis and lung cancer--preliminary results]. / Stezenie CEA, przeciwcial skierowanych przeciw antygenom pratkowym oraz aktywnosc ACE w surowicy i w BALF chorych na sarkoidoze, gruzlice i raka pluca--wyniki wstepne.

UNLABELLED: Assessment of CEA concentration, levels of the antibodies against mycobacterial antigens A60 and 38 kDa and ACE activity in serum and in BALF of the patients with sarcoidosis (n = 8), tuberculosis (n = 13) and lung cancer (n = 10) was performed. Nine healthy volunteers were referred to as the control group. Sarcoidosis and lung cancer were confirmed histopathologically. Diagnosis of tuberculosis was stated using the radiometric Bactec 460 system. Serum and BALF CEA concentration and IgG levels against A-60 and 38 kDa were measured by ELISA: IMx, Immunozym and Pathozyme, respectively. ACE activity was assayed by the spectrophotometric method. Statistically significant (p < 0.01) increase in BALF-ACE activity in patients with sarcoidosis compared to each group was observed. Serum level of antibodies against 38 kDa and serum ACE activity were specific for tuberculosis and sarcoidosis respectively, but their sensitivity were very poor. Serum CEA concentration was fairly specific for lung cancer but its sensitivity was not satisfactory. CONCLUSIONS: 1. Determination of BALF-ACE activity may be helpful in diagnosis of sarcoidosis but it is recommended to continue the study on more numerous groups of patients taking into consideration polymorphism in the ACE gene. 2. High level of antibodies against 38 kDa and ACE activity in serum are specific for tuberculosis and sarcoidosis respectively but both tests have restricted application because of their poor sensitivity. 3. Serum CEA concentration could be considered only as an auxiliary test in the diagnosis of lung cancer.

[Frequency and intensity of behavioral and psychological symptoms in the course of Alzheimer's disease]. / Czestosc oraz intensywnosc wystepowania zaburzen psychicznych i zachowania w otepieniu o róznym nasileniu w przebiegu choroby Alzheimera.

The aim of the study was: 1) to estimate the occurrence and intensity of some psychopathological symptoms in the course of Alzheimer's disease, and 2) to examine whether the occurrence of behavioral and psychological symptoms increases with the deepening of dementia process among persons with Alzheimer's disease living in their homes with outpatient treatment. The study was conducted among 94 persons (38 men and 56 women ageing from 52 to 86 years (x = 72.4 +/- 6.9), with education: from 2 to 17 years (x = 11.2 +/- 3.7). Three subgroups were selected for study with regard to the intensity of dementia process, estimated according to Clinical Dementia Rating (CDR): very mild (n = 16, x = 71.4 +/- 6.7), mild (n = 43, x = 72.6 +/- 7.9), moderate (n = 35, x = 72.5 +/- 6.9). Subjects in group II and III fulfill diagnostic criteria of dementia according to ICD-10, DSM IV and criteria of probable AD according to NINCDS-ADRDA. In the estimation of occurrence of behavioral and psychological disturbances: Alzheimer's Disease Assessment Scale--non-cognitive behavior (ADAS-non-cog) and subscale "Change in Personality, Interests, Drive" of Blessed Dementia Scale were used. The results have shown that with the progress of dementia process, the occurrence of the following psychopathological symptoms such as: hallucinations, intensive motor activity, purposeless hyperactivity, pacing, rigidity increases and there is a relinquishment of hobbies. In addition, regardless of the stage of dementia, such behaviors as: apathy, depression, tearfullness, impaired emotional control and disturbances of appetite were observed relatively frequently.

Depressed immune surveillance against cancer: role of deficient T cell: extracellular matrix interactions.

Although T cells infiltrate malignant tumors, the local immune response is usually inefficient and tumors escape destruction. While extracellular matrix proteins strongly costimulate T cell responses in normal individuals, our studies indicate that peripheral blood T cells from cancer patients and tumor infiltrating cells respond poorly or are resistant to stimulative signals mediated by collagen I and IV and fibronectin. Moreover, the adhesive properties of cancer T cells are markedly depressed. Those functional deficiencies are paralleled by variable deficits in integrin and non-integrin T cell receptors for extracellular matrix. Immunotherapy with BCG causes a dramatic but transient increase in T cell: ECM interactions.

[Morphohistochemical examination of white rat kidneys kept on a diet containing electroenergetic ashes]. / Badania morfohistochemiczne nerki szczurów bialych pozostajacych na diecie zawierajacej popioly elektroenergetyczne.

Kidneys of the rats kept on a diet containing electroenergetical ashes were examined histochemically. An increase in activity of enzymes in cells of kidney canaliculi in animals which were the longest subject to experiment, were observed.