Wyniki wyszukiwania - Biblioteka Nauki

1

Purple membranes with fluorinated retinal

100%

Bryl K. , Yoshihara K.

Biophysics of Membrane Transport

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1994

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tom 12

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nr 2

2

Study on Coordination and Noncovalent Interactions in Cu(II), L-Aspartic acid and Adenosine-5'-monophosphate Systems

88%

Bregier-Jarzebowska R. , Gasowska A. , Abd El-Latif S. T.

Polish Journal of Chemistry

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2008

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tom Vol. 82, nr 11

2057-2065

EN

In the L-aspartic acid (Asp) and adenosine-5c-monophosphate (AMP) systems molecular complexes (Asp)Hx(AMP) are formed as a result of noncovalent dipole-ion interactions between Asp and AMP. Stability constants of particular species has been determined and the interaction centres have been identified as the deprotonated carboxyl groups and the amine group from Asp along with the phosphate group and endocyclic nitrogen atoms from AMP. At pH close to 7 an inversion in the character of the interactions takes place: in an acidic medium the N(1)H group from AMP is a positive reaction centre, while in a basic medium after deprotonation it becomes a negative reaction centre. In the ternary system of Cu(II)/Asp/AMP the formation of protonated complexes of the type Cu(Asp)Hx(AMP), heteroligand complex Cu(Asp)(AMP) and hydroxocomplex Cu(Asp)(AMP)(OH) have been observed to form. The modes of coordination have been established on the basis of the spectroscopic data and equilibrium studies. At low pH the introduction of copper(II) ions to the binary system does not change the sites of intermolecular noncovalent interactions of the bioligands. Start ing from pH near 4, the presence of Cu(II) ions totally eliminates the noncovalent interactions between bioligands observed in the Asp/AMP binary systems.

3

Selection and activation of Escherichia coli strains for L-aspartic acid biosynthesis

88%

Papierz M. , Gadomska G. , Sobierajski B. , Chmiel A.

Polish Journal of Microbiology

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2007

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tom 56

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nr 2

EN

The strain of Escherichia coli K-12 with high aspartase activity was irradiated with UV. After mutagenesis and selection, the mutant B-715 was isolated which was 4-times more active in L-aspartic acid biosynthesis than parental K-12 strain. The highest productivity was achieved while the strain was cultivated in the ammonium fumarate medium in 37°C for 18-30 hours. It was found that better results were obtained when before the main production step of biosynthesis of L-aspartic acid, the cells of E. coli B-715 were incubated in the activation medium with ammonium fumarate. Activation at 37°C was the most advisable for high efficiency of L-aspartic acid biosynthesis. The productivity of E. coli B-715 during 1 hour biosynthesis process was at the range 0.19-0.35 g of L-aspartic acid per 1 gram of dry mass (biomass) per minute.

4

Recombinant strains of Escherichia coli for L-aspartic acid biosynthesis

75%

Gadomska G. , Plucienniczak A. , Chmiel A.

Polish Journal of Microbiology

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2007

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tom 56

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nr 2

EN

The aspartase overproducing mutant B-715 was used as a donor of the aspartase gene for further construction of the aspartase-hyperproducing strains by molecular cloning. In preliminary experiments activity of transformants and their efficiency in L-aspartic acid biosynthesis were compared. The conditions for recombinant strain multiplication, biomass activation and L-aspartic acid biosynthesis were optimized. The optimum temperature for cells multiplication, their activation and for product biosynthesis was 37°C. Two-stage process of the multiplication of bacteria (first in LB medium, and then in FF medium) eliminates the appearing of the inclusion bodies of aspartase in the cells. The shaking during cell activation improved cells productivity. The change of pH in the course of the biosynthesis process was insignificant but did not influence the process.

5

Determination of free and bound amino acids in three strains of Naegleria

63%

Alonso P. , Zubiaur E.

Acta Protozoologica

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1989

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tom 28

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nr 2

6

Chitosan-based hyrogel for industrial waste treatment

63%

Piątkowski M. , Bogdał D. , Radomski P. , Jarosiński A.

Czasopismo Techniczne. Chemia

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2011

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tom R. 108, z. 1-Ch

127-134

EN

The method of chitosan-based hydrogel synthesis from chitosan, aspartic acid and ethylene glycol under microwave irradiation is presented in this article. Application of microwave radiation enables to reduce the reaction time and elimination of catalyst from reaction mixture. Synthesised hydrogel is examined as sorption agent for metal ions (Fe[^2+/3+], Zn[^2+] and Hg[^2+]) within 12 h and 168 h and sorption capacity is calculated.

PL

W artykule przedstawiono metodę otrzymywania hydrożelu na bazie chitozanu, kwasu asparaginowego i glikolu etylenowego w polu promieniowania mikrofalowego, co pozwala na skrócenie czasu reakcji oraz wyeliminowanie katalizatora ze środowiska reakcji. Otrzymany hydrożel zbadano pod kątem wykorzystania jako czynnika sorpcyjnego dla jonów metali (Fe[^2+/3+], Zn[^2+] i Hg[^2+]) w ciągu 12 h i 168 h, a także obliczono pojemność sorpcyjną.

7

Effect of amino acids on the pig muscle enolase

63%

Niemczuk M. , Wolna E.

Archivum Immunologiae et Therapiae Experimentalis

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1993

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tom 41

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nr 1

8

Synteza hydrożeli na bazie soli poli(kwasu asparaginowego) i poli(kwasu akrylowego) wykazujących strukturę przenikających się sieci polimerowych

51%

Grzesik R. , Lukosek M. , Torchała K. , Kotyrba Ł. , Wójcik J.

Przemysł Chemiczny

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2020

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tom T. 99, nr 12

1712--1716

PL

W środowisku wodnym sporządzono mieszaniny typu przenikających się sieci polimerowych w wyniku sieciowania poli(kwasu akrylowego) wobec soli potasowej lub amonowej poli(kwasu asparaginowego). Wykazano, że wartość pH ma duży wpływ na przebieg tego procesu. Otrzymane substancje miały właściwości hydrożelu.

EN

Interpenetrating polymer networks (IPN) of poly(aspartic acid) and poly(acrylic acid) salts were produced by crosslinking of poly(acrylic acid) in the presence of K or NH salts of poly(aspartic acid) (PAs-K and PAs-A, resp.) 4 in aq. soln. The pH of reaction mixts. had a high impact on the process. IPN of PAs-A and poly(acrylic acid) showed hydrogel-like properties and were recommended as water absorbing additives to mineral fertilizers.

9

Zastosowanie promieniowania mikrofalowego w syntezie biodegradowalnego kopolimeru kwasu asparaginowego z kwasem mlekowym

51%

Pagacz J. , Polaczek J. , Pielichowski J. , Migdał M. , Tokarska A.

Polimery

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2009

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tom T. 54, nr 7-8

514-521

PL

Przedstawiono wyniki badań nad nową, polegającą na zastosowaniu promieniowania mikrofalowego metodą otrzymywania biodegradowalnego kopolimeru (PAL): kwas asparaginowy (KA)-kwas mlekowy (KM). Syntezę prowadzono w warunkach różnego stosunku molowego reagentów, temperatury i mocy promieniowania, w roztworze lub w stopie, bez użycia katalizatora oraz - dla porównania - w jego obecności (H3PO4). Oceniono również przebieg degradacji w roztworze soli fizjologicznej kopolimerów PAL otrzymywanych w stopie. Budowę chemiczną produktów scharakteryzowano za pomocą spektroskopii w podczerwieni (FT-IR) oraz protonowego magnetycznego rezonansu jądrowego (1H NMR). Metodą chromatografii żelowej (GPC) oznaczono ciężar cząsteczkowy tych produktów, a także określono ich właściwości termiczne wykorzystując do tego celu termograwimetrię (TG) oraz różnicową kalorymetrię skaningową (DSC).W zależności od doboru badanych, wyżej wymienionych warunków kopolimeryzacji, jak również metody jej prowadzenia uzyskano materiały różniące się ciężarem cząsteczkowym, krystalicznością, rozpuszczalnością oraz odpornością termiczną.

EN

The results of investigations on the new method, based on microwave radiation use, of preparation of aspartic acid (KA)/lactic acid (KM) biodegradable copolymer (PAL) are presented. The syntheses were carried out at various molar ratios of reagents, different temperature and radiation dose, in the solution or bulk, without catalyst (H3PO4) or - for comparison - with it (Table 1-4). The course of degradation of PAL copolymers prepared in bulk, in physiological solutions was also evaluated (Fig. 1). Chemical structure of the products were characterized by infrared spectroscopy (FT-IR) (Fig. 2 and 3) and nuclear magnetic resonance (1H NMR) (Fig. 4). Molecular weights of the products (Table 5) were determined by gel permeation chromatography (GPC). Thermal properties were investigated by thermogravimetry (TG) (Fig. 5, Table 6) and differential scanning calorimetry (DSC) (Fig. 6 and 7, Table 7). Dependently on the method of copolymerization and its conditions the resulted materials varied in molecular weights, crystallinity, solubility and thermal stability.

10

SHP-2 and PTP PEST induction during Rb-E2F associated apoptosis

51%

Morales L. D. , Pena K. , Kim D. J. , Lieman J. H.

Cellular and Molecular Biology Letters

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2012

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tom 17

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nr 3

EN

Apoptosis is intimately connected to cell cycle regulation via the Retinoblastoma (Rb)-E2F pathway and thereby serves an essential role in tumor suppression by eliminating aberrant hyperproliferative cells. Upon loss of Rb activity, an apoptotic response can be elicited through both p53-dependent and p53-independent mechanisms. While much of this apoptotic response has been attributed to the p19ARF/p53 pathway, increasing evidence has supported the role of protein tyrosine phosphatases (PTPs) in contributing to the initiation of the Rb-E2F-associated apoptotic response. One protein tyrosine phosphatase, PTP-1B, which is induced by the Rb-E2F pathway, has been shown to contribute to a p53-independent apoptotic pathway by inactivating focal adhesion kinase. This report identifies two additional PTPs, SHP-2 and PTP-PEST, that are also directly activated by the Rb-E2F pathway and which can contribute to signal transduction during p53-independent apoptosis.

11

Long-term effect of neonatal monosodium glutamate [MSG] treatment on reproductive system of the female rat

51%

Miskowiak B. , Kesa B. , Limanowski A. , Patryka M. , Filipiak B.

Folia Morphologica

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1999

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tom 58

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nr 2

EN

The study aimed at determining effects of monosodium glutamate (MSG), introduced in the perinatal period, on the reproductive system of .sexually mature female rats. ln days 2, 4, 6, 8, l0 the: newborns received s.c. injections of MSG (4 mg/g body weight) or2% NaCl solution. When the animals reached the age of 6, l2 or l8 months, their ovaries and uteri were isolated for histological and morphometric studies while in their sera estradiol level was estimated by the RIA technique. The perinatal injection of MSG was found to decrease relative weights of ovaries and uteri. In the ovaries increased numbers of primordial follicles and deceased numbers of graafian follicles were detected . Also the thickness of endometrium and of the epithelium, which lined the endometrium, were lowered in females, which received perinatal injections of MSG, as compared to the controls. Serum estradiol level in MSG injected females was lowered at the age of 12 and 18 month old females the alterations were accompanied by obesity and a decreased body length.

12

Environment of Mg2 cation and hydrogen bonding system in lactate and citrate magnesium salts

44%

Majzner W. R. , Wieczorek M. W. , Blaszczyk J. , Krol B. W.

Zeszyty Naukowe. Politechnika Łódzka. Chemia Spożywcza i Biotechnologia

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1998

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tom 59

13

Optimal production conditions of an extracellular protease from Streptomyces corchorusii ST 36

44%