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J Nawrocki

Publications and source records attributed to J Nawrocki.

At least 19 recordsLinked to original sources
PubMed2005

[Vitreous surgery with trypan blue staining of membranes in PVR retinal detachment surgery].

BACKGROUND: In our clinic we used trypan blue staining routinely for removal of internal limiting membranes (ILM) and epiretinal membranes (ERM) during vitreoretinal surgery for PVR retinal detachment. PATIENTS AND METHODS: We treated 27 eyes of 27 patients with severe PVR retinal detachment with vitreoretinal surgery. After complete vitrectomy and removal of epiretinal membranes we injected 0.15 % trypan blue solution and proceeded with further removal of the visualized remaining epiretinal membranes and ILM. We performed relaxing retinotomies in 14 eyes. Follow-up lasted six months. RESULTS: After the first surgery the retina was reattached in 24 of 27 eyes and after the second surgery in all eyes. The final visual acuity was: hand movements in 3 eyes, 1/50 or better in 24 eyes (eight of them had a visual acuity of 0.1 - 0.5). No case of macular pucker was observed during the follow-up. CONCLUSIONS: Trypan blue staining during vitreoretinal surgery in PVR retinal detachment therapy allows complete removal of ILM, ERM, and peripheral vitreous. It upgrades the quality of the surgery.

Female↗
PubMed2005

The biological evaluation of Zato 50 WG in protection of carrot against Alternaria blight.

Effectiveness of new fungicide Zato 50 WG (biologically active substances BAS - trifloxystrobin 50%) in the control of Alternaria blight on carrot was studied. Field experiments were carried out in the years 2003-2004 on carrot cv. Koral. As the standard fungicide Amistar 250 SC (BAS - azoxystrobin 250 g/dm3) was used. The results of health status of carrot leaves analysis in first and second year of experiment showed, that development of disease symptoms was lower on leaves of chemical protected plants than on leaves of control plants. The last estimation of infestation degree of carrot leaves made immediately before harvest showed, that standard fungicide Amistar had longer systemic influence on plants. This was confirmed the lower (statistically significant) infestation index of protected carrot in combination with Amistar. The estimations of health status of carrot roots were made directly after digging up indicate, that there wasn't difference of value of infestation index between protected combination and control. Experiment showed, significant effect of tested fungicides on crop quantity of carrot roots per 1 m2. Especially in the second year of study the crop of carrot roots in combination with Zato was higher - statistically significant - than in the rest combinations.

Alternaria↗
PubMed2004

Part II. Chromatography using ultra-stable metal oxide-based stationary phases for HPLC.

In this part of the review authors discuss methods used for modification of metal oxide surfaces. On the basis of literature data it is shown, that silanization of the surfaces do not form stable supports for chromatography. On the other hand, the success of polymer modified surfaces such as polybutadiene (PBD) and polystyrene (PS) is emphasized. Permanent modification of metal oxide surfaces with Lewis bases is also widely discussed. Chromatographic properties of polymer modified surfaces of zirconia are discussed in details. The perspectives of carbon-coated metal oxide surfaces in HPLC and high temperature separations are described.

Chromatography, High Pressure Liquid↗
PubMed2004

Part I. Chromatography using ultra-stable metal oxide-based stationary phases for HPLC.

The first part of the review contrasts the main drawbacks of silica-based packings such as their relative thermal and chemical instability with excellent stability of metal oxides. The paper concerns mainly ZrO2, TiO2 and Al2O3. Methods of preparation of spherical particles for HPLC are described. Surface chemistry of the oxides is, however, very different from that of silica. Ability of the oxides to ion- and ligand exchange is discussed from a chromatographic point of view.

Chromatography, High Pressure Liquid↗
PubMed2004

Biodegradability of organic by-products after natural organic matter oxidation with ClO2--case study.

Apart from well-known chlorites and chlorates, chlorine dioxide also generates easily biodegradable carbonyl compounds and short chain carboxylic acids during water disinfection. The main goal of the presented study was to examine the influence of natural organic matter (NOM) oxidation with chlorine dioxide, on the quantity as well as the quality of formed biodegradable by-products. In the experiments conducted at the pilot plant the sand filtered water (MWI) and ozonated/biofiltrated water (BAF) were oxidised with ClO2. The amount of BDOC formed as a result of the oxidation of both waters with ClO2 was compared. The results showed considerable differences in formation of ClO2 oxidation by-products between non-ozonated and ozonated/biofiltered waters. The disinfection of ozonated/biofiltrated water with ClO2 generated comparable amounts of aldehydes and much higher amounts of carboxylic acids than ClO2 oxidation of sand filtered water. These findings are essential for waterworks with ozonation/biofiltration units and ClO2 disinfection implemented.

Biodegradation, Environmental↗
PubMed2004

Reactivity of natural organic matter fractions with chlorine dioxide and ozone.

The effects of ozone and chlorine dioxide on the aquatic natural organic matter (NOM) were studied. The natural as well as oxidised organic matter in aerated and sand filtered water were fractionated using XAD, anion-exchange, and cation-exchange resins procedure into humic acid, hydrophobic acids and neutrals, and hydrophilic acids, bases and neutrals. The main NOM components were hydrophobic, while oxidation with both ozone and chlorine dioxide increased the proportion of hydrophilic fractions. High-pressure size exclusion chromatography with UV-254 nm and UV-220 nm detection was used to determine the differences between molecular weight distribution of natural and oxidised organic matter fractions. The main purpose of this paper was to compare the reactivity of individual NOM fractions with oxidants in order to compare the productivity of biodegradable by-products after oxidation with chlorine dioxide and ozone. The quantity as well as the quality of by-products were analysed by means of ion and gas chromatography.

Biodegradation, Environmental↗
PubMed2004

Effectiveness of some means using against root rot on parsley seedling root.

The results of a two-year study concern the effectiveness of 4 substances--biopreparate Chitosol (beta-1,4 D-glucosamine polymer) and fungicides: Rovral Flo 255 SC (BAS iprodione 255 g/dm3), Sportak Alpha 380 EC (BAS prochloraz 0,300 dm3/dm3 and carbendazim 80 g/dm3) and Zaprawa Funaben T (carbendazim 20% + tiuram 45%)--used against root rot and plant rot was described. These experiments were conducted in glasshouse and field conditions. Root of parsley cultivar Berlińska were treated one of tested substances autumn before storage period in clamp or spring immediately before planting seedling roots. The results showed that autumn dressing was ineffective, indices of root infestation were similar in each combination including control in both years of observation. Spring dressing was better, but not only in controls were many parsley plants decaying in the fields. Among substances used for spring dressing of seedling roots, the best efficacy exhibited Zaprawa Funaben T and Sportak Alpha 380 EC.

Alternaria↗
PubMed2003

Reduction of ClO2 demand by ClO2 oxidation and subsequent GAC filtration.

The effective removal of soluble natural organic matter (NOM) during water treatment can significantly decrease the ClO(2) demand of processed water. This can be achieved through the oxidation and/or the removal of NOM. The purpose of the study was to examine the influence of ClO(2) oxidation and subsequent GAC filtration on the final ClO(2) demand of treated water. The study showed the ClO(2) demand to be strongly correlated with the abundance of high molecular fractions of NOM in treated water. As it was shown, this part of NOM was effectively removed during the GAC filtration. Moreover, the pre-treatment of water with ClO(2) considerably increased the total capacity of GAC filters for organic and inorganic (i.e. chlorites) oxidation by-products. Therefore, the oxidation of NOM molecules in conjunction with a very efficient GAC filtration can be successfully employed to control the abundance of high molecular NOM components, and thus the ClO(2) demand of finished water.

Chlorine Compounds↗
PubMed2003

Formation of aldehydes upon ClO2 disinfection.

Carbonyl compounds are considered to be the most common ozonation by-products. Apart from well-known chlorites and chlorates, chlorine dioxide (ClO(2)) also generates organic by-products. The goal of this paper is an investigation into the influence of disinfection with ClO(2) on the aldehydes formation. Three types of waters were disinfected with different doses of ClO(2) at the various pH values. The results of size exclusion chromatography show that the reaction of ClO(2) with humic fraction of natural organic matter proceeds mainly on an aromatic part of the molecules. The results obtained indicate that the level of carbonyls concentration can significantly increase with the time of ClO(2) reaction with carbonyl precursors in treated water. There is no noticeable correlation between quantity of aldehydes and pH value of disinfected water. The range of "productivity" of aldehydes in water treated with chlorine dioxide is similar to the range estimated for the carbonyls formed upon ozonation.

Aldehydes↗
PubMed2003

Aldehyde contamination of mineral water stored in PET bottles.

Aldehyde contaminations that might accompany production of mineral water stored in PET bottles were investigated. One of the production lines of carbonated mineral water in Poland was monitored and PET bottles commonly used for mineral water storage were evaluated. Formaldehyde and acetaldehyde were the most important carbonyls identified in series of bottled water samples, but also propanal, nonanal and glyoxal were found in water samples from the production line. Aldehydes are present everywhere in the environment and can be determined even in pure water at low microg l(-1) levels. It was observed that the concentration of acetaldehyde in water stored in PET bottles depended mainly on the concentration of acetaldehyde in PET material and could reach more than 200 microg l(-1). The temperature, time of storage and concentration of carbon dioxide gas contribute to the migration of aldehydes from bottle walls to mineral water. Higher pressure of the carbonated waters and not CO(2) itself or lower pH of waters seems responsible for higher concentration of acetaldehyde.

Aldehydes↗
PubMed2002

Adsorption of natural organic matter oxidized with ClO2 on granular activated carbon.

The paper describes the influence of the oxidation of natural organic matter (NOM) molecules with chlorine dioxide (ClO2) on granulated activated carbon (GAC) adsorption. In order to determinate the influence of ClO2 dosage on the NOM adsorption on GAC two parallel pilot scale experiments were performed. The raw water was treated respectively with 0.2 and 0.4 mg ClO2 L(-1) followed by the adsorption on GAC filters. Experiments were total organic carbon (TOC) measurements and size exclusion chromatography (SEC) controlled. The molecular weight distribution of NOM in the filtration bed outlet demonstrates that the low molecular weight molecules are less retained than the higher molecular weight components of NOM. It is shown that low molecular weight NOM causes less ClO2 demand. The oxidation of NOM molecules and very high capacity of GAC filter bed for NOM components can be used to control high ClO2 demand.

Adsorption↗
PubMed2002

Investigation of carbonyl compounds in bottled waters from Poland.

Poly(ethylene terephtalate) (PET) bottles are commonly used for storing mineral water. The migration of carbonyl compounds from PET bottles into mineral water was observed. Carbonation of water, sunlight and high temperature enhance the process of migration. Formaldehyde, acetaldehyde and acetone were the most important carbonyls identified in series of bottled water samples. The concentration of carbonyls can change depending on the time of storage as well as storage conditions. It was identified particularly high concentration of acetaldehyde (more than 100 microg 1(-1)) in samples of mineral water saturated with CO2 gas.

Aldehydes↗
PubMed2001

Derivatization of the mutagen MX (3-chloro-4(dichloromethyl)-5-hydroxy-2(5H)-furanone) with butyl alcohols prior to GC-MS analysis.

An extremely potent mutagen, 3-chloro-4(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) is commonly present in chlorinated drinking water. Due to its high mutagenic activity and according to WHO guidelines its concentration should be controlled in drinking waters. Determination of MX is difficult due to the low (ppt) levels at which the compound usually exists in drinking waters. Results obtained with butanols as MX derivatization agents are shown and derivatization with sec-butanol is presented as a method which significantly lowers GC/MS detection levels of MX.

Butanols↗
PubMed2000

Low-carbon silica sorbents for solid-phase extraction.

The applicability of silica gels, modified with cyclic organosiloxanes, in solid-phase extraction (SPE) has been tested. Surface characteristics of the adsorbents prepared are determined by: elemental analysis, 29Si cross-polarisation magic angle spinning nuclear magnetic resonance spectroscopy (29Si CP MAS NMR) and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. The sorbents with low carbon contents are used for extraction of chlorinated pesticides, polychlorinated biphenyls and nitro-compounds from water. The properties of the sorbents are compared with commercial C18 ones. It is shown that the low-carbon silica SPE sorbents can ensure satisfactory recoveries and reveal some selectivity.

Adsorption↗
PubMed2000

[Implantation of black diaphragm intraocular lenses in congenital and traumatic aniridia].

PURPOSE: To evaluate the safety and efficacy of the black diaphragm intraocular lens (IOL) implantation for the treatment of congenital and traumatic aniridia. MATERIAL AND METHODS: Seven black diaphragmatic IOLs were implanted in the eyes of 6 patients between 1997 and 1998. There were 5 males and 1 female. The mean age of them was 42.8 years (range: 22-54 years). Follow-up ranged from 9 to 20 months (mean: 14.2 months). Traumatic aniridia was present in 4 eyes and congenital aniridia in 3 eyes. Pars plana vitrectomy was combined with the simple outside-in method of scleral fixation of IOLs in 6 cases. Three of these eyes were aphakic (all with traumatic aniridia) and in 3 eyes (two congenital cases, one traumatic case) subluxated lens was simultaneously removed. In one case of congenital aniridia with mature cataract, ECCE and ciliary sulcus implantation without scleral fixation were performed. RESULTS: There were very few complications. Ciliary sulcus bleeding appeared in 2 cases during scleral fixation. Transient post-operative corneal oedema was observed in 2 eyes, raised intraocular pressure in 3 eyes, and dispersed blood in vitreous cavity in 2 eyes. All IOLs were well centred. The improvement in best corrected visual acuity was achieved in 5 cases, while good pre-operative best corrected visual acuity was maintained in 2 cases. CONCLUSIONS: Diaphragmatic IOL can be fixated to the sclera in cases without capsular support or it can be implanted into ciliary sulcus after ECCE. Reconstruction of 5 mm pupil and intraocular correction of aphakia enable good visual rehabilitation of patients. The combined procedure of pars plana vitrectomy and scleral fixation of diaphragmatic lens is safe and effective in traumatic and congenital aniridia.

Adult↗