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1.
Entropy (Basel) ; 22(9)2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-33286783

RESUMO

This article presents several algorithms for controlling water supply system pumps. The aim of having control is the hydraulic optimisation of the network, i.e., ensuring the desired pressure in its recipient nodes, and minimising energy costs of network operation. These two tasks belong to the key issues related to the management and operation of water supply networks, apart from the reduction in water losses caused by network failures and ensuring proper water quality. The presented algorithms have been implemented in an Information and Communications Technology (ICT) system developed at the Systems Research Institute of the Polish Academy of Sciences (IBS PAN) and implemented in the waterworks GPW S.A. in Katowice/Poland.

2.
Opt Express ; 28(21): 30810-30823, 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33115074

RESUMO

The article presents analysis of the formation of charge carrier domains generated by a localized optical beam and the phenomenon of their oscillations. The research was carried out for bipolar photorefractive semiconductors characterized by nonlinear transport of electrons. The analysis allowed us to determine a set of basic quantitative parameters that have an impact on the appearance of carrier oscillations and their character.

3.
Opt Express ; 22(4): 4599-605, 2014 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-24663779

RESUMO

This article analyzes nonlinear light propagation in semiconductors with bipolar conductivity and nonlinear transport of electrons. We show how the competition between electron and hole conductivity can influence light propagation, leading to the self-bending effect of optical beam trajectory, which depending on the value of trap compensation coefficient may be stationary or transient.

4.
Opt Express ; 22 Suppl 7: A1907-25, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25607504

RESUMO

Nonlinear light propagation in photorefractive media can be analyzed by numerical methods. The presented numerical approach has regard to the effects of time nonlocality. Two algorithms are presented, and compared in terms of physical results and computing times. The possibility to address the issue of time nonlocality in two ways is attributed to the fact that, it is possible to completely separate carrier dynamics evaluation and wave equation calculation. This in turn, allows to choose a short integration time for carrier dynamics and a longer one to solve the wave equation. The tests of the methods were carried out for a one-carrier model that describes most of photorefractive media, and for a model with bipolar transport and hot electron effect, used in descriptions of semiconductor materials.

5.
Food Chem ; 139(1-4): 482-7, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23561134

RESUMO

A sensitive, accurate and reliable multiresidue method based on the application of gas chromatography-tandem quadrupole mass spectrometry (GC-QqQ-MS/MS) has been established for screening, identification and quantification of a large number of pesticide residues in produce. The method was accredited in compliance with PN-EN ISO/IEC 17025:2005 standard and it was operated under flexible scope as PB-11 method. The flexible scope of accreditation allowed for minor modifications and extension of the analytical scope while using the same analytical technique. During the years 2007-2010, the method was used for the purpose of verification of organic crop production by multiresidue analysis for the presence of pesticides. A total of 528 samples of differing matrices such as fruits, vegetables, cereals, plant leaves and other green parts were analysed, of which 4.4% samples contained pesticide residues above the threshold value of 0.01 mg/kg. A total of 20 different pesticide residues were determined in the samples.


Assuntos
Grão Comestível/química , Contaminação de Alimentos/análise , Alimentos Orgânicos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Resíduos de Praguicidas/análise , Verduras/química , Polônia , Espectrometria de Massas em Tandem/métodos
6.
Carbohydr Res ; 339(7): 1347-52, 2004 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-15113673

RESUMO

A highly phosphorylated O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Proteus mirabilis O41 followed by GPC. The initial and dephosphorylated polysaccharides and phosphorylated products from two sequential Smith degradations were studied by (1)H, (13)C and (31)P NMR spectroscopy and ESI-MS. The O-polysaccharide was found to have a tetrasaccharide repeating unit containing one ribitol phosphate (presumably d-Rib-ol-5-P) and two ethanolamine phosphate (Etn-P) groups, one of which is present in the stoichiometric amount and the other in a nonstoichiometric amount. The following structure of the O-polysaccharide was established:


Assuntos
Antígenos O/química , Proteus mirabilis/química , Sequência de Carboidratos , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Estrutura Molecular , Antígenos O/isolamento & purificação , Antígenos O/metabolismo , Pentosefosfatos/química , Fosforilação
7.
Eur J Immunol ; 33(10): 2842-52, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14515268

RESUMO

We show that Proteus vulgaris O25 (PO25) lipopolysaccharide (LPS) induced an anaphylactoid reaction not only in wild-type and in lipid A non-responding mice but also in recombinase-activating gene-2-deficient (RAG-2(-/-)) and in mast cell-deficient (W/Wv) animals. Western blot analysis indicated that PO25 LPS bound to Ra-reactive factor (RaRF), the complex of mannan-binding lectins (MBL) and MBL-associated serine proteases. Binding of RaRF to PO25 LPS led to the activation of C4 component without participation of either C1 or Ig, via the lectin pathway. Relative concentration of RaRF and hemolytic activity in mouse serum decreased rapidly during the process of anaphylactoid reaction. A significant drop of MBL-A, but not MBL-C level was observed. Administrationwith antiserum to RaRF prevented animals from death as a consequence of the inhibition of interaction of RaRF with the carbohydrate target and complement activation. These results indicate that complement-lectin pathway activation is responsible for the anaphylactoid reaction induced with LPS in muramyldipeptide-primed mice. RaRF also activated fibrinogen in vitro suggesting the involvement of the coagulation system in the process investigated.


Assuntos
Anafilaxia/etiologia , Ativação do Complemento , Lipopolissacarídeos/toxicidade , Lectina de Ligação a Manose/fisiologia , Serina Endopeptidases/fisiologia , Animais , Fibrinogênio/metabolismo , Serina Proteases Associadas a Proteína de Ligação a Manose , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H
8.
Carbohydr Res ; 338(13): 1425-30, 2003 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-12801716

RESUMO

The O-polysaccharide (O-antigen) of Providencia alcalifaciens O21 was obtained by mild acid degradation of the lipopolysaccharide and studied by chemical methods and NMR spectroscopy. It was found that the polysaccharide is built up of branched pentasaccharide repeating units with a terminal residue of 3-formamido-3,6-dideoxy-D-galactose (D-Fuc3NFo) and has the following structure: [structure: see text]. Anti-P. alcalifaciens O21 serum cross-reacted with the O-antigen of Proteus vulgaris O47, which contains a GalNAc trisaccharide similar to that present in the P. alcalifaciens O21 O-polysaccharide.


Assuntos
Antígenos O/química , Oligossacarídeos de Cadeias Ramificadas/química , Providencia/química , Acetilgalactosamina/análise , Amino Açúcares/análise , Sequência de Carboidratos , Reações Cruzadas/imunologia , Ácidos Hexurônicos/análise , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Oligossacarídeos de Cadeias Ramificadas/imunologia , Proteus vulgaris/química , Proteus vulgaris/imunologia
9.
Carbohydr Res ; 337(24): 2463-8, 2002 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-12493231

RESUMO

An acidic O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Proteus vulgaris O15 and studied by sugar and methylation analyses along with 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, ROESY, and H-detected 1H,(13)C HMQC experiments. The polysaccharide was found to contain an ether of GlcNAc with lactic acid, and the following structure of the repeating unit was established:-->3)-alpha-D-GlcpNAc4(R-Lac)6Ac-(1-->2)-beta-D-GlcpA-(1-->3)-alpha-L-6dTalp2Ac-(1-->3)-beta-D-GlcpNAc-(1-->where L-6dTal and D-GlcNAc4(R-Lac) are 6-deoxy-L-talose and 2-acetamido-4-O-[(R)-1-carboxyethyl]-2-deoxy-D-glucose, respectively. The latter sugar, which to our knowledge has not been hitherto found in nature, was isolated from the polysaccharide by solvolysis with anhydrous triflic acid and identified by comparison with the authentic synthetic compound. Serological studies with the Smith-degraded polysaccharide showed an importance of 2-substituted GlcA for manifesting of the immunospecificity of P. vulgaris O15.


Assuntos
Ácidos Murâmicos/química , Antígenos O/química , Polissacarídeos/química , Proteus vulgaris/química , Configuração de Carboidratos , Sequência de Carboidratos , Carboidratos/análise , Lipopolissacarídeos/química , Lipopolissacarídeos/imunologia , Metilação , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular
10.
Carbohydr Res ; 337(18): 1667-71, 2002 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-12423969

RESUMO

The O-specific polysaccharide of Providencia alcalifaciens O16 was obtained by mild-acid degradation of the lipopolysaccharide and studied by chemical methods and NMR spectroscopy, including 2D 1H,(1)H COSY, TOCSY, NOESY, and 1H,(13)C HSQC experiments. It was found that the polysaccharide contains N-acetylmuramic acid, which was isolated by solvolysis with trifluoromethanesulfonic acid and identified by the specific optical rotation and NMR spectroscopy. The following structure of the trisaccharide repeating-unit of the polysaccharide was established:


Assuntos
Ácidos Murâmicos/química , Ácidos Murâmicos/isolamento & purificação , Antígenos O/química , Providencia/química , Configuração de Carboidratos , Sequência de Carboidratos , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular , Rotação Ocular , Providencia/classificação
11.
Arch Immunol Ther Exp (Warsz) ; 50(5): 345-50, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12455869

RESUMO

O-specific polysaccharide (O-antigen) of the lipopolysaccharide of Proteus penneri 20 was studied using sugar analysis along with various one- and two-dimensional NMR spectroscopy techniques. The following structure of the polysaccharide was established: [formula: see text] It has the same carbohydrate backbone structure as that described earlier for P. penneri 16, in which the positions of the O-acetyl groups have not been determined. P. penneri 20 O-antiserum showed a strong cross-reactivity with the lipopolysaccharides of P. penneri 10, 16, 18, 32, 45 and P. mirabilis O17. These data enable classifying these strains together with P. penneri 20 in one Proteus serogroup, O17.


Assuntos
Antígenos O/química , Proteus/classificação , Proteus/imunologia , Acetilação , Animais , Anticorpos Antibacterianos , Técnicas de Tipagem Bacteriana , Sequência de Carboidratos , Reações Cruzadas , Humanos , Dados de Sequência Molecular , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Antígenos O/isolamento & purificação , Proteus/patogenicidade , Coelhos , Sorotipagem , Especificidade da Espécie
12.
Microbiology (Reading) ; 147(Pt 10): 2769-2781, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11577156

RESUMO

Polycations [protamine, polymyxin B nonapeptide (PMBN) and polyethyleneimine (PEI)] have been shown to increase the cell wall permeability of Mycobacterium vaccae to highly hydrophobic compounds, as manifested in enhanced intracellular bioconversion of beta-sitosterol to 4-androsten-3,17-dione (AD) and 1,4-androstadien-3,17-dione (ADD), and cell sensitization to erythromycin and rifampicin. The quantity of AD(D) formed per biomass unit was twice as high in the presence of PMBN and PEI, and three times higher with protamine. The sensitization factor, i.e. the MIC(50) ratio of the control bacteria to those exposed to polycations, ranged from 4 to 16, depending on the polycation/antibiotic combination. Non-covalently bound free lipids were extracted from the control and polycation-treated cells and fractionated with the use of chloroform, acetone and methanol. Chloroform- and acetone-eluted fractions (mainly neutral lipids and glycolipids, respectively) showed significant polycation-induced alterations in their quantitative and qualitative composition. The fatty acid profile of neutral lipids was reduced in comparison to control, whereas acetone-derived lipids were characterized by a much higher level of octadecenoic acid (C(18:1)) and a considerably lower content of docosanoic acid (C(22:0)), the marker compound of mycolate-containing glycolipids. Methanol-eluted fractions remained unaltered. Cell-wall-linked mycolates obtained from delipidated cells were apparently unaffected by the action of polycations, as judged from the TLC pattern of mycolic acid subclasses, the mean weight of mycolate preparations and the C(22:0) acid content in the mycolates, determined by GC/MS and pyrolysis GC. The results suggest the involvement of the components of non-covalently bound lipids in the outer layer in the M. vaccae permeability barrier.


Assuntos
Permeabilidade da Membrana Celular/efeitos dos fármacos , Parede Celular/metabolismo , Mycobacterium/metabolismo , Poliaminas/farmacologia , Antibacterianos/farmacologia , Parede Celular/química , Parede Celular/efeitos dos fármacos , Eritromicina/farmacologia , Ácidos Graxos/análise , Testes de Sensibilidade Microbiana , Mycobacterium/química , Mycobacterium/efeitos dos fármacos , Ácidos Micólicos/análise , Polieletrólitos , Rifampina/farmacologia , Sitosteroides/metabolismo , Propriedades de Superfície
13.
J Med Microbiol ; 49(2): 127-138, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10670563

RESUMO

The saccharide constituents of lipopolysaccharides (LPS) of Proteus spp. vary with the strain and contain unique components about which little is known. The biological activities of LPS and lipid A from S- and R-forms of 10 Proteus strains were examined. LPS from all S-form Proteus strains was lethal to D-(+)-galactosamine (GalN)-loaded, LPS-responsive, C3H/HeN mice, but not to LPS-hypo-responsive C3H/HeJ mice. P. vulgaris 025 LPS evoked strong anaphylactoid reactions in N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP)-primed C3H/HeJ mice. LPS from S- and R-form Proteus strains induced production of nitric oxide (NO) and tumour necrosis factor (TNF) by macrophages isolated from C3H/HeN but not C3H/HeJ mice. Lipid A from Proteus strains also induced NO and TNF production, although lipid A was less potent than LPS. The effects of LPS were mainly dependent on CD14; LPS-induced NO and TNF production in CD14+ J774.1 cells was significantly greater than in CD14-J7.DEF.3 cells. All LPS from Proteus strains, and especially from P. vulgaris 025, exhibited higher anti-complementary activity than LPS from Escherichia coli or Pseudomonas aeruginosa. Polymyxin B inactivated proteus LPS in a dose-dependent manner, but these LPS preparations were more resistant to polymyxin B than E. coli LPS. CAP18(109-135), a granulocyte-derived peptide, inhibited proteus LPS endotoxicity only when the LPS:CAP18(109-135) ratio was appropriate, which suggests that CAP18(109-135) acts through a different mechanism than polymyxin B. The results indicate that LPS from Proteus spp. are potently endotoxic, but that the toxicity is different from that of LPS from E. coli or Salmonella spp. and even varies among different Proteus strains. The variation in biological activities among proteus LPS may be due to unique components within the respective LPS.


Assuntos
Peptídeos Catiônicos Antimicrobianos , Proteínas de Transporte/farmacologia , Lipopolissacarídeos/toxicidade , Fragmentos de Peptídeos/farmacologia , Polimixina B/farmacologia , Proteus/efeitos dos fármacos , Proteus/patogenicidade , Acetilmuramil-Alanil-Isoglutamina/administração & dosagem , Sequência de Aminoácidos , Anafilaxia/induzido quimicamente , Animais , Sequência de Carboidratos , Proteínas de Transporte/química , Catelicidinas , Proteínas Inativadoras do Complemento/farmacologia , Feminino , Galactosamina/administração & dosagem , Lipídeo A/antagonistas & inibidores , Lipídeo A/toxicidade , Receptores de Lipopolissacarídeos/imunologia , Lipopolissacarídeos/antagonistas & inibidores , Ativação de Macrófagos , Masculino , Camundongos , Camundongos Endogâmicos C3H , Dados de Sequência Molecular , Óxido Nítrico/biossíntese , Proteus/metabolismo , Proteus mirabilis/efeitos dos fármacos , Proteus mirabilis/metabolismo , Proteus mirabilis/patogenicidade , Proteus vulgaris/efeitos dos fármacos , Proteus vulgaris/metabolismo , Proteus vulgaris/patogenicidade , Fator de Necrose Tumoral alfa/biossíntese
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