Silicon's Influence on Polyphenol and Flavonoid Profiles in Pea (Pisum sativum L.) under Cadmium Exposure in Hydroponics: A Study of Metabolomics, Extraction Efficacy, and Antimicrobial Properties of Extracts

The current study aimed to investigate the impact of silicon (Si) supplementation in the form of Na2SiO3 on the metabolome of peas under normal conditions and following exposure to cadmium (Cd) stress. Si is known for its ability to enhance stress tolerance in various plant species, including the mitigation of heavy metal toxicity. Cd, a significant contaminant, poses risks to both human health and the environment. The study focused on analyzing the levels of bioactive compounds in different plant parts, including the shoot, root, and pod, to understand the influence of Si supplementation on their biosynthesis. Metabolomic analysis of pea samples was conducted using a targeted HPLC/MS approach, enabling the identification of 15 metabolites comprising 9 flavonoids and 6 phenolic acids. Among the detected compounds, flavonoids, such as flavon and quercetin, along with phenolic acids, including chlorogenic acid and salicylic acid, were found in significant quantities. The study compared Si supplementation at concentrations of 1 and 2 mM, as well as Cd stress conditions, to evaluate their effects on the metabolomic profile. Additionally, the study explored the extraction efficiency of three different methods: accelerated solvent extraction (ASE), supercritical fluid extraction (SFE), and maceration (MAC). The results revealed that SFE was the most efficient method for extracting polyphenolic compounds from the pea samples. Moreover, the study investigated the stability of polyphenolic compounds under different pH conditions, ranging from 4.0 to 6.0, providing insights into the influence of the pH on the extraction and stability of bioactive compounds.

Metal tolerance and Cd phytoremoval ability in Pisum sativum grown in spiked nutrient solution

In the presented study, the effects of cadmium (Cd) stress and silicon (Si) supplementation on the pea plant (Pisum sativum L.) were investigated. The tendency to accumulate cadmium in the relevant morphological parts of the plant (roots and shoots respectively)-bioaccumulation, the transfer of this element in the plant (translocation) and the physiological parameters of the plant through indicators of oxidative stress were determined. Model studies were carried out at pH values 6.0 and 5.0 plant growth conditions in the hydroponic cultivation. It was shown that Cd accumulates mostly in plant roots at both pH levels. However, the Cd content is higher in the plants grown at lower pH. The Cd translocation factor was below 1.0, which indicates that the pea is an excluder plant. The contamination of the plant growth environment with Cd causes the increased antioxidant stress by the growing parameters of the total phenolic content (TPC), polyphenol oxidase activity (PPO), the malondialdehyde (MDA) and lipid peroxidation (LP). The results obtained showed that the supplementation with Si reduces these parameters, thus lowering the oxidative stress of the plant. Moreover, supplementation with Si leads to a lower content of Cd in the roots and reduces bioaccumulation of Cd in shoots and roots of pea plants.

Reducing phase errors in multimode interference coupler by side grooves formed on its top surface

The performance of multimode interference (MMI) couplers is limited by the presence of phase errors that represent the deviation of the propagation constants of the modes from the quadratic dependence on their order. In this work, we propose a simple and effective method for reducing the phase errors of spatial modes to a relatively high order by forming rectangular grooves near the side edges of the MMI coupler along its entire length. The influence of the groove dimensions and position on the propagation constants of higher-order modes is analyzed using the perturbation method and strict vector simulations for high- and medium-index contrast material platforms. Through numerical simulations, we demonstrate the effectiveness of the proposed method in improving the performance of air-cladded dual-mode (T E 0 and T E 1) MMI-based 50:50 and 100:0 splitters for 1.31 µm wavelength made of medium- and high-contrast materials, T i O 2:S i O 2/S i O 2 and S i/S i O 2, respectively.

Dielectric properties of the non-glycated and in vitro methylglyoxal-glycated cornea of the rabbit eye

The dielectric properties of the non-glycated and in vitro methylglyoxal-glycated cornea of the rabbit eye were tested in the frequency range of 200 Hz to 100 kHz of the electric field and at temperatures of 25 to 140 °C. The denaturation temperature (T_d) for the non-glycated cornea and the non-enzymatically glycated cornea are approximately 45 and 55 °C, respectively. The mechanism of proton conduction up to T_d in a glycated cornea requires more energy, i.e. more than twice the activation energy (ΔH) than in non-glycated tissue. The dielectric spectra for both examined tissues showed the same characteristic frequency of about 7 kHz assigned to the orientation relaxation time of the polar side groups inside the corneal stroma. These results may be useful in the surgical treatment of the cornea using conductive keratoplasty and in tissue engineering for clinical applications to regenerate this tissue. The medical use of these physico-biological techniques is important because the human cornea protects all eye tissues from various environmental factors.

Ceramic surface relief gratings imprinted on an optical fiber tip

We report on the fabrication, experimental measurement, and numerical simulation of sol-gel diffraction grating structures deposited on the end-face of a single mode optical fiber. Using the imprint method, we manufactured surface relief grating structures in four configurations with different grating-relative-to-fiber arrangements. We demonstrate the high quality of the fabricated structures based on atomic force microscopy imaging and their operational characteristics, presenting measured and simulated far-field intensity distributions. Using a numerical model, we simulated the diffraction patterns in the far-field. We obtained strong agreement between the results of the simulations and the experiments in terms of the angular positions of the diffraction peaks. We also investigated the tolerance of fabricated structures to high-power lasers. Among the proposed structures, the most intriguing is the grism fabricated on a fiber end-face using sol-gel imprint technology for the first time, to the best of our knowledge.

Whole-genome single nucleotide polymorphism analysis for typing the pandemic pathogen Fusarium graminearum sensu stricto

Recent improvements in microbiology and molecular epidemiology were largely stimulated by whole- genome sequencing (WGS), which provides an unprecedented resolution in discriminating highly related genetic backgrounds. WGS is becoming the method of choice in epidemiology of fungal diseases, but its application is still in a pioneer stage, mainly due to the limited number of available genomes. Fungal pathogens often belong to complexes composed of numerous cryptic species. Detecting cryptic diversity is fundamental to understand the dynamics and the evolutionary relationships underlying disease outbreaks. In this study, we explore the value of whole-genome SNP analyses in identification of the pandemic pathogen Fusarium graminearum sensu stricto (F.g.). This species is responsible for cereal diseases and negatively impacts grain production worldwide. The fungus belongs to the monophyletic fungal complex referred to as F. graminearum species complex including at least sixteen cryptic species, a few among them may be involved in cereal diseases in certain agricultural areas. We analyzed WGS data from a collection of 99 F.g. strains and 33 strains representing all known cryptic species belonging to the FGSC complex. As a first step, we performed a phylogenomic analysis to reveal species-specific clustering. A RAxML maximum likelihood tree grouped all analyzed strains of F.g. into a single clade, supporting the clustering-based identification approach. Although, phylogenetic reconstructions are essential in detecting cryptic species, a phylogenomic tree does not fulfill the criteria for rapid and cost-effective approach for identification of fungi, due to the time-consuming nature of the analysis. As an alternative, analysis of WGS information by mapping sequence data from individual strains against reference genomes may provide useful markers for the rapid identification of fungi. We provide a robust framework for typing F.g. through the web-based PhaME workflow available at EDGE bioinformatics. The method was validated through multiple comparisons of assembly genomes to F.g. reference strain PH-1. We showed that the difference between intra- and interspecies variability was at least two times higher than intraspecific variation facilitating successful typing of F.g. This is the first study which employs WGS data for typing plant pathogenic fusaria.

Optical Thin Films Fabrication Techniques-Towards a Low-Cost Solution for the Integrated Photonic Platform: A Review of the Current Status

In the past few decades, several methods concerning optical thin films have been established to facilitate the development of integrated optics. This paper provides a brief depiction of different techniques for implementing optical waveguide thin films that involve chemical, physical, and refractive index modification methods. Recent advances in these fabrication methods are also been presented. Most of the methods developed for the realization of the thin-films are quite efficient, but they are expensive and require sophisticated equipment. The major interest of the scientists is to develop simple and cost-effective methods for mass production of optical thin films resulting in the effective commercialization of the waveguide technology. Our research group is focused on developing a silica-titania optical waveguide platform via the sol-gel dip-coating method and implementing active and passive optical elements via the wet etching method. We are also exploring the possibility of using nanoimprint lithography (NIL) for patterning these films so that the fabrication process is efficient and economical. The recent developments of this platform are discussed. We believe that silica-titania waveguide technology developed via the sol-gel dip-coating method is highly attractive and economical, such that it can be commercialized for applications such as sensing and optical interconnects.

Reducing bend-induced loss and crosstalk in a two-mode ridge waveguide by steplike thickness structuring

This study demonstrated that two-step structuring of the waveguide thickness in a bent section significantly reduces bend-related inter-mode crosstalk, excess loss, and pure bending loss. A simple analytical formula was derived linking the thickness change required to compensate for bend-induced effects with geometrical parameters of the waveguide and bending radius. The effectiveness of the proposed approach was verified through rigorous numerical simulations of the loss and inter-mode crosstalk based on transformation optics formalism. The numerical results obtained for a TiO₂:SiO₂ medium index contrast waveguide exhibited significant improvement of all relevant parameters for TE₀₀ and TE₀₁ modes.

Patterns of Diversity of Fusarium Fungi Contaminating Soybean Grains

Soybean is an important, high protein source of food and feed. However, like other agricultural grains, soybean may pose a risk to human and animal health due to contamination of the grains with toxigenic Fusaria and associated mycotoxins. In this study, we investigated the diversity of Fusaria on a panel of 104 field isolates obtained from soybean grains during the growing seasons in 2017-2020. The results of species-specific PCR analyses showed that Fusarium avenaceum was the most common (n = 40) species associated with soybean grains in Poland, followed by F. equiseti (n = 22) and F. sporotrichioides (11 isolates). A set of isolates, which was not determined based on PCR analyses, was whole genome sequenced. Multiple sequence analyses using tef-1α, top1, rpb1, rpb2, tub2, pgk, cam and lsu genes showed that most of them belonged to Equiseti clade. Three cryptic species from this clade: F. clavum, F. flagelliforme and FIESC 31 (lacking Latin binomial) were found on soybean for the first time. This is the first report demonstrating the prevalence of Fusaria on soybean grains in Poland.

Dielectric response to thermal denaturation of lenses in healthy and diabetic rabbits

The relative permittivity and conductivity of healthy and alloxane-induced diabetic rabbits lenses were measured over a frequency range of 500 Hz to 100 kHz in an electric field and at temperatures from 25 to 150 °C. The dielectric spectra for both tissues showed two separate relaxations with a characteristic frequency of around 4 and 25 kHz assigned to the cortical and nuclear zones, respectively. These two dispersions are due to the interfacial polarization at the surface of the α-crystallin molecules. The denaturation temperature for the non-diabetic lens and the diabetic lens is approximately 70 and 80 °C, respectively. Moreover, the relative permittivity and conductivity values are higher in the diabetic lens than in the non-diabetic tissue at the same temperature and frequency. Our dielectric studies provide a better understanding of the thermal stability of crystallin-water complexes in normal and diseased human lenses.

Enhancement of spectral response of Bragg gratings written in nanostructured and multi-stepped optical fibers with radially shaped GeO2 concentration

We present experimental results on fiber Bragg gratings inscription in nanostructured graded-index (nGRIN) and multi-step index (MSIN) optical fibers, both having non-uniform radial distribution of GeO₂ dopant in the fiber cores. In particular, the positive role of radial shaping the GeO₂ distribution in the fiber core on grating reflection efficiency is reported. We postulate that an appropriate spatial distribution of the germanium concentration that matches the fundamental mode profile improves grating spectral response due to more efficient grating-mode interaction, as compared with uniformly doped step-index optical fibers with the same overall doping level. Moreover, we show that radially shaped fibers exhibit moderately higher temperature responses than their step-index counterparts.

International Nosocomial Infection Control Consortium (INICC) report, data summary of 45 countries for 2012-2017: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2012 to December 2017 in 523 intensive care units (ICUs) in 45 countries from Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, prospective data from 532,483 ICU patients hospitalized in 242 hospitals, for an aggregate of 2,197,304 patient days, were collected through the INICC Surveillance Online System (ISOS). The Centers for Disease Control and Prevention-National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI) were applied.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the medical-surgical ICUs, the pooled central line-associated bloodstream infection rate was higher (5.05 vs 0.8 per 1,000 central line-days); the ventilator-associated pneumonia rate was also higher (14.1 vs 0.9 per 1,000 ventilator-days,), as well as the rate of catheter-associated urinary tract infection (5.1 vs 1.7 per 1,000 catheter-days). From blood cultures samples, frequencies of resistance, such as of Pseudomonas aeruginosa to piperacillin-tazobactam (33.0% vs 18.3%), were also higher.

CONCLUSIONS

Despite a significant trend toward the reduction in INICC ICUs, DA-HAI rates are still much higher compared with CDC-NHSN's ICUs representing the developed world. It is INICC's main goal to provide basic and cost-effective resources, through the INICC Surveillance Online System to tackle the burden of DA-HAIs effectively.

Pupil autoregulation impairment as an early marker of glaucomatous damage

BACKGROUND

Glaucoma, a degenerative and progressive disease, leads to structural and functional changes in the optic nerve head and retinal ganglion cells (RGCs), while the vasculature of the iris stays intact.

OBJECTIVES

The aim of this study was to determine whether the coherence level associated with pupil geometry and peripheral arterial pulsation can be the basis for differentiating glaucoma and glaucoma-suspected patients from a control group.

MATERIAL AND METHODS

This is an investigator-initiated, single-center prospective cohort study. Patients with diagnosed glaucoma (glaucoma group - GG) or glaucoma suspects (glaucoma suspects group - GSG), as well as healthy participants (control group - CG), were prospectively enrolled in the study. Glaucoma-diagnosed patients and glaucoma suspects who converted to glaucoma within 5 years were included. All patients underwent a full ophthalmological examination that included measurements of the thicknesses of the retinal nerve fiber layer (RNFL) and the ganglion cell complex (GCC) along with other parameters. A custom-made pupilometer was synchronized with a pulsometer to simultaneously record an image of the pupil and the peripheral arterial pulsation signal. All readings were processed with a script developed by the researchers. The main indicator of an increased influence of the vascular structures of the iris on pupil geometry in the patients and CG were the coherence levels (levC) between parameters describing the pupillary shape and peripheral arterial pulsation.

RESULTS

Differences in the median value of the levCpS, levCpε and levCpθ parameters between the GG and GSG compared to the CG were found (p < 0.001). During the follow-up period, a larger decrease was observed in RNFL thickness and GCC thickness in the GSG than in the GG (p < 0.05). Strong correlations were found between levCpS and RNFL and GCC loss among the GSG group (p < 0.001), while in the GG this parameter correlated with RNFL and GCC thickness (p < 0.001).

CONCLUSIONS

This is the first attempt to relate changes in the neuronal signaling pathways in glaucoma to the vascular-dependent changes of pupil geometry. The findings presented herein suggest that this approach can be used to determine which glaucoma suspects have autonomic system impairment in the eye, increasing their probability of glaucoma conversion.

Method for direct coupling of a semiconductor quantum dot to an optical fiber for single-photon source applications

We present an effective method for direct fiber coupling of a quantum dot (QD) that is deterministically incorporated into a cylindrical mesa. For precise positioning of the fiber with respect to the QD-mesa, we use a scanning procedure relying on interference of light reflected back from the fiber end-face and the top surface of the mesa, applicable for both single-mode and multi-mode fibers. The central part of the fiber end-face is etched to control the required distance between the top surface of the mesa and the fiber core. Emission around 1260 nm from a fiber-coupled InGaAs/GaAs QD is demonstrated and its stability is proven over multiple cooling cycles. Moreover, a single photon character of emission from such system for a line emitting above 1200 nm is proven experimentally by photon autocorrelation measurements with an obtained value of the second order correlation function at zero time-delay well below 0.5.

Species Composition and Trichothecene Genotype Profiling of Fusarium Field Isolates Recovered from Wheat in Poland

Fusarium head blight (FHB) of cereals is the major head disease negatively affecting grain production worldwide. In 2016 and 2017, serious outbreaks of FHB occurred in wheat crops in Poland. In this study, we characterized the diversity of Fusaria responsible for these epidemics using TaqMan assays. From a panel of 463 field isolates collected from wheat, four Fusarium species were identified. The predominant species were F. graminearum s.s. (81%) and, to a lesser extent, F. avenaceum (15%). The emergence of the 15ADON genotype was found ranging from 83% to 87% of the total trichothecene genotypes isolated in 2016 and 2017, respectively. Our results indicate two dramatic shifts within fungal field populations in Poland. The first shift is associated with the displacement of F. culmorum by F. graminearum s.s. The second shift resulted from a loss of nivalenol genotypes. We suggest that an emerging prevalence of F. graminearum s.s. may be linked to boosted maize production, which has increased substantially over the last decade in Poland. To detect variation within Tri core clusters, we compared sequence data from randomly selected field isolates with a panel of strains from geographically diverse origins. We found that the newly emerged 15ADON genotypes do not exhibit a specific pattern of polymorphism enabling their clear differentiation from the other European strains.

Is eye lens dosimetry needed in nuclear medicine?

INTRODUCTION

The exact level of exposure experienced by nuclear medicine personnel, whose work often requires performing manual procedures involving radioactive isotopes, is associated with the form of radiation source used. The variety of radionuclides and medical procedures, and the yearly increase in the number of patients, as well as the change of the individual dose limit for the lens of the eye from a value of 150 mSv yr^-1 to 20 mSv yr^-1, mean that issues of eye lens routine dosimetry become interesting from the radiation protection point of view.

OBJECTIVE

This paper presents an analysis of the exposure of the eye lenses of nuclear medicine department personnel, as well as those of personnel in the facilities that produce radiopharmaceuticals for the purpose of diagnosis by positron emission tomography, from the viewpoint of the advisability of routine eye lens exposure monitoring, taking into account changes in the dose limit for the lens of the eye.

MATERIALS AND METHODS

The paper considers the two most commonly used radionuclides for diagnostic purposes ^99mTc, ¹⁸F, and-for therapeutic purposes-¹³¹I. Dose measurements were made using thermoluminescent detectors.

RESULTS

The estimated exposure analysis identifies the cases when the maximum annual value of the personal dose equivalent, in terms of Hp(3), exceeds threefold the new limit value (20 mSv yr^-1).

CONCLUSIONS

It is recommended that Hp(3) doses be routinely monitored in the group of radiopharmacists who label pharmaceuticals with the radionuclide ^99mTc and in chemists working in ¹⁸F-FDG quality control departments in production units, where this is carried out manually.

International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs.

CONCLUSIONS

Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically.

Dielectric study of interaction of water with normal and osteoarthritis femoral condyle cartilage

The main goal of this paper is the in vitro study of healthy and osteoarthritis (OA) human cartilage using the dielectric spectroscopy in the alpha-dispersion region of the electric field and in the temperatures from 25 to 140°C. The activation energy of conductivity needed to break the bonds formed by water in the extracellular matrix takes the average values of 61kJ/mol and 44kJ/mol for the control and OA cartilages, respectively. At 28°C, the small difference appears in the permittivity decrement between the control and OA cartilages, while the conductivity increment is about 2 times higher for the control tissue than that for the OA tissue. At 75°C, the conductivity increment for both of these samples is 8 times higher than their respective permittivity decrement. In addition, at 140°C the values of these both parameters for the OA tissue decrease by 8 times as compared to those recorded for the control sample. The relaxation frequency of about 10kHz is similar for both of these samples. The knowledge on dielectric properties of healthy and OA cartilage may prove relevant to tissue engineering focused on the repair of cartilage lesions via the layered structure designing.

Higher-order rocking filters induced mechanically in fibers with different birefringence dispersion

We studied the transmission characteristics of higher-order rocking filters induced mechanically in birefringent microstructured fibers and standard elliptical core fibers with varying spectral dependence of phase modal birefringence. We demonstrated the effect of birefringence dispersion on polarization mode coupling induced by a point-like force. We also investigated the spectral dependence of the resonance depth and force-induced resonance wavelength shift in mechanical rocking filters. The observed phenomena were explained by a numerical model linking the spectral dependence of the polarization mode coupling coefficient with the dispersion of intrinsic fiber birefringence and applied force.

Nonlinear frequency conversion in a birefringent microstructured fiber tuned by externally applied hydrostatic pressure

We studied vector frequency conversion in externally tuned microstructured fibers for applications as a novel, nonlinear fiber-optic sensor. We investigated both experimentally and numerically a possibility of shifting vector and scalar modulation instability gain bands by pressure-induced changes in the linear properties of a microstructured fiber. Our results show that polarization-dependent vector nonlinear processes sensitive to variation of fiber group velocity difference (group birefringence) exhibit a clear advantage for pressure-sensing applications compared with scalar nonlinear processes only sensitive to group velocity dispersion changes. Analytical predictions and numerical simulations confirm our measurement results.

Dielectric properties of hypothermic rat artery

The temperature and frequency dependencies of the dielectric parameters for the rat artery are used to analyse effects of hypothermia on this tissue. Measurements were performed over the frequency range 500 Hz to 100 kHz and at temperatures from 19 to 60°C. The artery samples contained about 12% water by mass at room temperature at a relative humidity of 70%. The frequency dependencies of the loss tangent for the control, mild hypothermic and moderate hypothermic artery exhibit two peaks at 2 kHz and 35 kHz in the α-dispersion region. The results were discussed in terms of the distribution of relaxation frequencies and the activation energy for the conduction and polarization mechanisms particularly in the elastin-water and collagen-water systems. The knowledge about dielectric behavior of the hypothermic rat artery in vitro is important due to clinical application of local and systemic hypothermia.

Hand exposure of nuclear medicine workers during administration of radioiodine

(131)I has been widely used in nuclear medicine for many years, particularly in the form of iodide for the diagnosis and therapy of thyroid cancer and other thyroid diseases. Manual dispensing of radioiodine-based radiopharmaceuticals results in potentially significant radiation doses to the hands of nuclear medicine personnel performing this task. This article reports the results of thermoluminescent dosemeter-based measurement of radiation doses at various points on the hands of personnel dispensing radioiodine radiopharmaceuticals.

Diabetes mellitus effect on rat corneal dielectric properties

In the course of the study, we carried out a dielectric examination to determine the effect of diabetes mellitus on the rat corneal function. Measurements were performed over the frequency range of 500 Hz-100 kHz in air and at the temperatures from 25 to 150°C. The frequency dependencies of the loss tangent for the healthy and the diabetic cornea exhibit two peaks at 2 kHz and 16 kHz in the α-dispersion region. The amplitude of these both peaks is smaller for the diabetic cornea than that for the healthy one. The temperature dependencies of the loss tangent for the healthy and the diabetic cornea reveal β-relaxation in the range of 30-70°C and 50-90°C, respectively. The present study exhibits that the dielectric spectroscopy is useful in detection of the effect of diabetes mellitus on the corneal molecular behavior.

Implications of the alpha dispersion for studies on interaction of tobacco smoke--corneal tissue

In this work, we have carried out a dielectric study to determine the effect of tobacco smoke on the rat corneal function. Measurements were performed over the frequency range of 500 Hz-100 kHz in air and at the temperature of 35°C. The frequency dependencies of the loss tangent for both healthy and smoky cornea exhibit two peaks with different width occurring as a narrow at 2 kHz and a broad at around 16 kHz. The distribution parameter α at 2 kHz has a value of about 0.3, which increases to 0.6 at 16 kHz. The magnitude of the permittivity decrement at 2 and 16 kHz is about two and four times higher, respectively, for the smoky cornea than that for the healthy one. These dielectric studies indicate that the present method is useful in detection of the effect of tobacco smoke exposure on the corneal behavior.

Supplementation with L-arginine does not influence arterial blood pressure in healthy people: a randomized, double blind, trial

BACKGROUND AND OBJECTIVES

It cannot be excluded that supplementation with L-arginine, by improving function of endothelium and hypotensive effect, can be advantegeous in prevention of cardiovascular diseases in healthy people. However, reports about hypotensive effect of L-arginine in healthy people are unclear. Moreover, no research including ambulatory blood pressure measurement (ABPM) has been conducted so far. Therefore, the aim of our study was to show if 4-week supplementation of healthy people with L-arginine influences blood pressure measured with ABPM.

MATERIALS AND METHODS

The study was carried out on 19 healthy people randomized to 6 g/24-hour, 12 g/24-hours of L-arginine or placebo. ABPM was carried out 4 times: before randomization, after 2 and 4 weeks of supplementation and 2 weeks after finishing supplementation.

RESULTS

It was found that 4 weeks of supplementation of healthy people with L-arginine (6 or 12 g/24-hour) led to nonsignificant decrease of systolic and diastolic blood pressure; the decrease was greater during night.

CONCLUSION

These findings showed that supplementation with L-arginine is not necessarily advantageous in healthy people.

Impaired nucleotide excision repair pathway as a possible factor in pathogenesis of head and neck cancer

Tobacco smoking is one of the major risk factors in pathogenesis of head and neck squamous cell carcinomas (HNSCC). Many of the chemical compounds present in tobacco are well-known carcinogens which form adducts with DNA. Cells remove these adducts mainly by the nucleotide excision repair pathway (NER). NER also eliminates a broad spectrum of pyrimidine dimers (CPD) and photo-products (6-4PP) induced by UV-radiation or DNA cross-links after cisplatin anti-cancer treatment. In this study DNA damage and repair was examined in peripheral blood lymphocytes obtained from 20 HNSCC patients and 20 healthy controls as well as HTB-43 larynx and SSC-25 tongue cancer cell lines. DNA repair kinetics in the examined cells after cisplatin or UV-radiation treatment were investigated using alkaline comet assay during 240min of post-treatment incubation. MTT assay was used to analyse cell viability and the Annexin V-FITC kit specific for kinase-3 was employed to determine apoptosis after treating the cells with UV-radiation at dose range from 0.5 to 60J/m(2). NER capability was assessed in vitro with cell extracts by the use of a bacterial plasmid irradiated with UV-light as a substrate for the repair. The results show that lymphocytes from HNSCC patients and HTB-43 or SSC-25 cancer cells were more sensitive to genotoxic treatment with UV-radiation and displayed impaired DNA repair. Also evidenced was a higher rate of apoptosis induction after UV-radiation treatment of lymphocytes from the HNSCC patients and the HTB-43 cancer cells than after treatment of those from healthy donors. Finally, our results showed that there was a significant decrease in NER capacity in HTB-43 or SSC-25 cancer cells as well as in peripheral blood lymphocytes of HNSCC patients compared to controls. In conclusion, we suggest that the impaired NER pathway might be a critical factor in pathogenesis of head and neck cancer.

Intermodal interferometer for strain and temperature sensing fabricated in birefringent boron doped microstructured fiber

We present a compact in-line fiber interferometric sensor fabricated in a boron doped two-mode highly birefringent microstructured fiber using a CO(2) laser. The intermodal interference arises at the fiber output due to coupling between the fundamental and the first order modes occurring at two fiber tapers distant by a few millimeters. The visibility of intermodal interference fringes is modulated by a polarimetric differential signal and varies in response to measurand changes. The proposed interferometer was tested for measurements of the strain and temperature, respectively, in the range of 20-700 °C and 0-17 mstrain. The sensitivity coefficients corresponding to fringe displacement and contrast variations are equal respectively for strain -2.51 nm/mstrain and -0.0256 1/mstrain and for temperature 16.7 pm/°C and 5.74×10(-5) 1/°C. This allows for simultaneous measurements of the two parameters by interrogation of the visibility and the displacement of interference fringes.

Polymorphisms of the DNA repair genes XRCC1 and ERCC4 are not associated with smoking- and drinking-dependent larynx cancer in a Polish population

BACKGROUND

Tobacco smoking and alcohol drinking generate oxidative DNA damage and may contribute to larynx carcinogenesis. The X-ray repair cross complementing 1 (XRCC1) and excision repair cross-complementing rodent repair deficiency, complementation group 4 (ERCC4(XPF)) genes are important components of DNA excision repair systems, which repair DNA damage induced by various factors, including tobacco smoking and alcohol.

AIM

To investigate the association between the genotypes of the XRCC1-Arg399Gln (rs25487) and ERCC4-Arg415Gln (rs1800067) polymorphisms and smoking- and drinking-related larynx cancer in a Polish population.

METHODS

The polymorphisms were determined by PCR-RFLP method in 253 patients with squamous cell carcinoma of the larynx and 253 sex- and age-matched controls.

RESULTS

We did not find any association between the investigated polymorphisms and larynx carcinoma, dependent on either smoking or drinking status. No association was found between these polymorphisms and larynx cancer grade, stage or age at diagnosis.

CONCLUSIONS

The results indicated that Arg399Gln polymorphism of XRCC1 gene and Arg415Gln polymorphism of ERCC4 gene may not be associated with smoking- and drinking-related larynx cancer in Polish population.

Highly birefringent microstructured fibers with enhanced sensitivity to hydrostatic pressure

We designed, manufactured and characterized two birefringent microstructured fibers that feature a 5-fold increase in polarimetric sensitivity to hydrostatic pressure compared to the earlier reported values for microstructured fibers. We demonstrate a good agreement between the finite element simulations and the experimental values for the polarimetric sensitivity to pressure and to temperature. The sensitivity to hydrostatic pressure has a negative sign and exceeds -43 rad/MPa x m at 1.55 microm for both fibers. In combination with the very low sensitivity to temperature, this makes our fibers the candidates of choice for the development of microstructured fiber based hydrostatic pressure measurement systems.

DNA double strand breaks repair and apoptosis induction in peripheral blood lymphocytes of head and neck cancer patients

AIM

To evaluate the generation and repair of DNA double strand breaks (DSBs) as a critical factors that define the efficiency of radiation therapy of cancer patients.

METHODS

Peripheral blood lymphocytes obtained from 18 patients with head and neck squamous cell carcinoma (HNSCC) and 18 healthy donors were studied. The efficiency of DSBs repair after genotoxic treatment with hydrogen peroxide and gamma-radiation were examined by neutral comet assay. MTT assay was used for cell viability analysis and Annexin V-FITC kit specific for kinase-3 was employed to determine apoptosis.

RESULTS

Lymphocytes from HNSCC patients were sensitive to genotoxic treatment and displayed impaired DSBs repair. Finally, as a consequence of this finding we have evidenced higher rate of apoptosis induction after gamma-radiation treatment of lymphocytes from HNSCC patients than those from healthy controls.

CONCLUSIONS

DSBs repair and increased apoptosis in cells of patients with head and neck cancer is relevant for efficient therapy of HNSCC.

Nonlinear control of soliton pulse delay with asymmetric dual-core photonic crystal fibers

Dual-core photonic crystal fiber nonlinear couplers permit the achievement of distortion-free power-controlled delay of picosecond pulses. The stable control of pulse time delay is achievable by means of resonance soliton solutions.

Polymorphisms of the DNA base excision repair gene MUTYH in head and neck cancer

BACKGROUND

Head and neck squamous cell carcinomas (HNSCC) comprise about 6% of all malignant neoplasms. The major risk factors of -HNSCC are smoking and alcohol consumption. Genetic polymorphisms of DNA repair enzymes may lead to genetic instability and carcinogenesis. MUTYH gene encodes a DNA glycosylase that can initiate the base excision repair (BER) pathway and prevent G:C > T:A transversion by excising adenine mispaired with 8-hydroxyguanine produced by reactive oxygen species (ROS).

AIM

to perform a case-control study to test the association between polymorphism in the MUTYH gene: Tyr165Cys and head and neck cancer risk progression.

METHODS

Genotypes were determined in DNA from peripheral blood lymphocytes of 193 patients (among them 97 subjects with precancerous hyperplastic laryngeal lesions and 96 subjects with head and neck cancer) and 140 age, sex and ethnic-matched cancer-free controls by tetra-primer amplification refractory mutation system PCR (T-ARMS-PCR).

RESULTS

We found an association between head and neck cancer risk and the Tyr165Tyr variant of the MUTYH gene (OR 2.18; 95% CI 1.19-3.97). For Tyr165Tyr genotype we also observed positive correlation with cancer progression assessed by tumor size (OR 4.56; 95% CI 1.60-12.95). We did not observe any correlation between Tyr165Cys polymorphism of MUTYH gene and precancerous hyperplastic laryngeal lesions risk.

CONCLUSION

The Tyr165Tyr polymorphic variant of the MUTYH gene may be associated with head and neck cancer in Polish population.

Birefringence in microstructure fiber with elliptical GeO2 highly doped inclusion in the core

We studied both numerically and experimentally a birefringence in a microstructure fiber with elliptical inclusion highly doped with GeO(2). We demonstrate that such inclusion increases the phase modal birefringence and modifies its dispersion in the short wavelength range, thus causing that group birefringence crosses zero value at a certain wavelength. Moreover, we numerically analyzed different factors contributing to the overall fiber birefringence, including geometrical birefringence induced by holes distribution and ellipticity of the inclusion as well as stress birefringence associated with thermal shrinkage of the doped glass.

Hand exposure to ionising radiation of nuclear medicine workers

The specific nature of work in nuclear medicine departments involves the use of isotopes and handling procedures, which contribute to the considerable value of an equivalent dose received, in particular, by the fingertips. Standard nuclear medicine department uses ring dosemeters placed usually at the base of the middle finger. The main aim of the study was to find out whether a relationship exists between the doses recorded by thermoluminescent detectors placed at various locations on the radiopharmacists' hands and the doses recorded by the ring detectors, and to determine the character of that relationship. The correction factor represents a correction value to be used to calculate the doses which might be received by locations on the hand from the dose recorded by the ring dosemeter. The dose recorded by the ring dosemeter is on the average five times lower than that received by the fingertips of thumb, index and middle fingers.

Experimental investigations of bending loss oscillations in large mode area photonic crystal fibers

We demonstrate experimentally that bending loss in large mode area photonic crystal fibers oscillates with wavelength. To do so we carried out loss measurements for different fiber bend radii and for different angular orientations. These results confirm the oscillatory behavior of bending loss vs. wavelength as predicted recently by numerical analysis [J. Olszewski et al., Opt. Express 13, 6015 (2005)]. We also found good agreement between our measurement results and our simulations relying on a finite element method with perfectly matched layers and an equivalent index model.

PCR approach based on the esyn1 gene for the detection of potential enniatin-producing Fusarium species

Fusarium head blight (FHB) is a disease of small-grain cereals and corn caused by a complex of fungal species of the genus Fusarium. The disease reduces the yield and quality of seeds and results in the accumulation of various mycotoxins which cause a variety of toxic effects on humans and livestock. Beauvericin (BEA) and enniatins (ENs) are a group of toxins with antimicrobial, insecticidal and phytotoxic activities produced mainly by F. avenaceum, F. poae and F. tricinctum. In this study, primer sets were designed that were targeted to esyn1 gene homologs encoding multifunctional enzyme enniatin synthetase. Primers used in multiplex PCR amplified products from the FHB species reported to produce (ENs) and/or BEA. The use of the marker developed on asymptomatic wheat seed samples originating from Northern and Southern Poland demonstrated that all samples were positive for the presence of potential enniatin-producing Fusarium species.

Sentinel node biopsy in patients with breast cancer—evaluation of exposureto radiation of medical staff

AIM

To measure the absorbed doses of radiation to hands of medical staff performing sentinel node biopsy in breast cancer patients.

METHODS

The study was conducted in 2004, during sentinel node biopsies in 13 breast cancer patients (T1/T2N0). Sentinel nodes were identified with the use of combined radiotracer/blue dye technique (lymphoscintigraphy--99mTc on albumin carrier, surgery after 24 h; blue dye; intraoperative detection of gamma radiation). Highly sensitive thermoluminescent dosimeters (TLD) made of LiF were used to assess the absorbed doses of radiation during the procedure. During lymphoscintigraphy and during surgical procedure a total of 57 TLDs was placed on different parts of hands of medical staff.

RESULTS

Maximal dose recorded during lymphoscintigraphy by TLDs placed on the hands of the physician injecting the radiotracer was 164 microSv. Mean recorded doses were higher for non-dominant hand, especially for distal parts of the index finger, third finger and thumb. During the surgical procedure, TLDs placed on the hands of medical staff recorded much lower doses of radiation than during lymphoscintigraphy. The highest dose was recorded by TLD placed on the pulp of the dominant hand index finger (22 microSv) of the operating surgeon. Mean doses recorded by TLDs placed on the hands of the operating surgeon ranged from 2 to 8 microSv. The absorbed dose of radiation to hands of the scrub nurse was similar to that absorbed to hands of the operating surgeon.

CONCLUSION

The maximum recorded dose during sentinel node biopsy in this study was 2200 times smaller than current 1-year dose limit.

Comparative assessment of aluminum and lead concentrations in serum and tissue bioptates in patients with laryngeal papilloma or cancer

A comparative assessment of toxic element concentrations in serum and tissue bioptates in patients with laryngeal papilloma or cancer was performed. Examinations were conducted in 60 patients (40 men and 20 women) aged 20-88 years (average 59 +/- 05). Patients were divided into 3 groups; 20 patients with laryngeal papilloma were in group I, 20 with laryngeal cancer were in group II, and 20 with deviated nasal septums were included as a control group (III). Diagnosis of laryngeal papilloma (removed by direct microlaryngoscopy--Kleinsasser method) and laryngeal cancer (removed by the Rethi method) was histopatologically confirmed in patients from groups I and II, respectively. Patients in the control group received functional surgery to repair deviated nasal septums. Serum and tissue samples were obtained from all patients before surgery. Aluminum and lead concentrations were analysed by inductively coupled plasma atomic emission spectrometry (ICP-AES) using a Spectroflame M spectrometer. The considerable rise of aluminum and lead concentration in tissue bioptates and aluminum in serum in groups I and II in comparison to the control group suggests that these elements may play a significant part in the aetiology and development of precancerous lesions and laryngeal cancers. Measuring toxic chemical element concentrations in tissue bioptates can be useful in the diagnosis and estimation of development of precancerous lesions of the larynx as well as laryngeal cancer. Toxic elements concentration may play a significant role in carcinogenesis and may determine trends in cancer aetiology.

Effect of coupling between fundamental and cladding modes on bending losses in photonic crystal fibers

The paper presents a fully vectorial analysis of bending losses in photonic crystal fibers employing edge/nodal hybrid elements and perfectly matched layers boundary conditions. The oscillatory character of losses vs. both the wavelength and the bending radius has been demonstrated. The shown oscillations originate from the coupling between the fundamental mode guided in the core and the gallery of cladding modes arising due to light reflection from the boundary between solid and holey part of the cladding.

Experimental and theoretical investigations of birefringent holey fibers with a triple defect

We have manufactured and characterized a birefringent holey fiber of a new construction. The birefringence in this fiber is induced by the highly elliptical shape of the core, which consists of a triple defect in a hexagonal structure. Using a hybrid edge-nodal finite-element method, we calculated the spectral dependence of phase and group modal birefringence for spatial modes E11 and E21 in idealized and in real fiber, whose geometry we determined by using a scanning-electron microscope. Results of our calculations show that technological imperfections significantly affect the fiber's birefringence. Normalized cutoff wavelengths for higher-order modes relative to the filling factor were also determined for the idealized structure. We observed a significant disagreement between theoretical and experimental values of cutoff wavelengths, which was attributed to high confinement losses near the cutoff condition. We also measured the spectral dependence of the phase and the group modal birefringence for spatial modes E11 and E21. The measured parameters showed good agreement with the results of modeling.

Qualitative and quantitative studies in electron microscopy on influence of experimental ischemia of the vertebral arteries on the outer hair cells function in guinea pigs

Histological studies were performed in 20 guinea pigs, both sexes, weighing 250-300 g and divided into two groups: I--control (anaesthetized animals without surgery), II--examined (in anaesthetized animals through an incision of the skin and muscles of the neck), the left or right vertebral artery was exposed and a vascular clip was inserted into the foramen of the transverse process of the 2-nd cervical vertebra. 50 days after this procedure, the guinea pigs were again anaesthetized by intraperitoneal injection of 35% solution of chloral hydrate, then vascular and cochlear perfusion with 3.6% solution of glutaraldehyde was performed. Simultaneously, by means of micropreparation, samples of cochlea were made for electron studies by means of electron microscope (Philips EM 300). In qualitative histopathologic examinations in guinea pigs of II group, the ischemia changes of the outer hair cells were greater in the side of irritation of the vertebral artery than at the opposite side. At the receptor side of these cells, under the membrane, there are multilamellar outgrowths in the shape of cisterns, partly expanded. The relative volume of external compartment of mitochondria in control group is as follows respectively: 0.15 +/- 0.0% at the right side and 0.15 +/- 0.08% at the left side, and in II group, respectively: 0.22 +/- 0.06% at the side of irritation and 0.19 +/- 0.07% at the opposite side. The obtained data in electron microscopy, both qualitative and quantitative pointed at ischemia changes of outer hair cells in guinea pigs after prolonged irritation of periarterial plexus of vertebral artery.

Distribution of equivalent doses to skin of the hands of nuclear medicine personnel

During direct contact with radiation sources, for example in nuclear medicine departments, the skin of the hands of workers is the area most exposed to radiation. Measurements with finger dosemeters containing thermoluminescent detectors showed that doses received may reach values as high as 100 mSv y(-1). The specific nature of work performed with isotopes contributes to the considerable differences in the value of an equivalent dose received by the metacarpus, wrist and fingertips. The annual equivalent doses to which fingertips are exposed may exceed the annual dose limit of 500 mSv.

[Therapeutic efficacy assessment of cefuroxime axetil in short 4 day course of empirical antibiotic therapy in patients with bacterial infections of upper respiratory tract and otitis media]

There were examined 261 patients aged 18-62 ambulatory treated and divided into five groups: I--65 patients with acute maxillary sinusitis, II--43 patients with exacerbation of chronic maxillary sinusitis, III--40 patients with angina, IV--61 patients with acute otitis media and V--52 patients with exacerbation of chronic otitis media. Cefuroxime axetil have applied 2 times a day in 500 mg oral dose by 4 days. The therapeutic efficacy of cefuroxime axetil was assessed on the basis: fever chart and self assessment chart of showed symptoms which were assessed from 0 to 4.4 days course antibiotic therapy showed that the total receding of illness symptoms stated in 90.8% patients with acute maxillary sinusitis, in 69.8% patients with exacerbation of chronic maxillary sinusitis, in 62.5% patients with angina, in 91.8% patients with acute otitis media and receding of acute symptoms of exacerbation with chronic otitis media--a ear pain in 88.5% patients and a ear leakage in 44.2% patients. The obtained results stated that the 4 days course of cefuroxime axetil can be sufficient and efficacy in treatment of acute bacterial infections of maxillary sinuses and ear media.

[Histopathological verifications clinical indications in the inferior turbinoplasty]

Surgical treatment in cases of disturbances of nasal patency caused changes in the nasal inferior turbinates are controversial. The authors performed the microscopic (light microscope) and morphometric examinations of mucous membrane of the nasal inferior turbinates obtained after inferior turbinoplasty in patients with vasomotor and perennial allergic rhinitis and compensation hypertrophy of nasal inferior turbinate accompanied of nasal deviation septum. Analysing of morphologic changes in mucous membrane of the nasal inferior turbinates verified of clinic indications to inferior turbinoplasty.