Wyniki wyszukiwania

1

Elements of thermodynamics in RNA evolution

100%

Kierzek E., Biala E., Kierzek R.

Acta Biochimica Polonica

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2001

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tom 48

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nr 2

The pa per pres ents some as pects cor re lat ing ther mal sta bil ity of RNA fold ing and the oc cur rence of struc tural mo tifs in nat u ral ri bo nu cleic ac ids. Par tic u larly, the ther- mody namic sta bil ity of 2 -5' and 3'-5' linked RNA and the contribution of unpaired ter mi nal nu cleo tides (dan gling ends) in sec ond ary (2D) and ter tiary (3D) struc tures of RNA are dis cussed. Both ex am ples sug gest that dur ing evo lu tion na ture se lected sequences and struc tures of RNA which are the most ther mally sta ble and ef fi cient for their bi o log i cal func tion.

2

Diagonal [canonical] form of the dissipation function

100%

Kargol M., Kosztolowicz T., Przestalski S.

Biophysics of Membrane Transport

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1994

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tom 12

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nr 2

3

Amphiphilic counterion effect on gell-fluid phase transition of lipid bilayers

100%

Kubica K.

Biophysics of Membrane Transport

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1994

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tom 12

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nr 2

4

Geochemical aspects of gold occurrence in the Fore-Sudetic Copper Deposit

100%

Jasinski A. W., Kijewski P.

Bulletin of the Polish Academy of Sciences. Earth Sciences

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1996

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tom 44

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nr 4

5

The thermodynamics of biomolecular sequences

88%

Dewey T. G.

Cellular and Molecular Biology Letters

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1999

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tom 04

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nr 1

A statistical mechanical treatment of biopolymers is presented that includes the sequence information as an internal coordinate. This approach allows an assessment of the contribution of sequence information to the thermodynamic entropy. Even in cases where the sequence composition has no effect on the intersubunit interactions, the sequence composition contributes to the entropy of the system. Using a path integral representation, the canonical partition function can be represented as a product of a polymer configurational path integral and a sequence walk path integral. In most, biological instances the sequence composition influences the potential energy of intersubunit interaction. Consequently, the two path integrals are not separable, but rather "interact" via a sequence-dependent configurational potential. Biological constraints can also be built into the system and these effectively introduce an external potential. In proteins and RNA, the sequence walk occurs in dimensions greater than 3 and, therefore, will be an ideal "polymer". The Markovian nature of this walk can be exploited to show that all the structural information is contained in the sequence. This later effect is a result of the dimensionality of the sequence walk and is not necessarily a result of biological optimization of the system.

6

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Termodinamicheskaja vozmozhnost' povyshenija ehffektivnocti DVS

75%

Podznoev G., Abdulgazic U., Zharik T.

Motrol. Motoryzacja i Energetyka Rolnictwa

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2014

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tom 16

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nr 1

7

Obosnovanie processa kondicionirovanija vozdukha s ispol'zovaniem sistemy recirkuljacii pri proizvodstve soloda

75%

Podlesnyjj V.

Motrol. Motoryzacja i Energetyka Rolnictwa

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2015

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tom 17

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nr 5

8

Investigation of the kinetics of the development of the distribution

75%

Marchenko D.

Teka Komisji Motoryzacji i Energetyki Rolnictwa

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2012

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tom 12

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nr 4

9

Helix-coil transition theories. Are they correct?

75%

Bierzynski A., Pawlowski K.

Acta Biochimica Polonica

|

1997

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tom 44

|

nr 3

Principles of contemporary theoretical description of a-helix formation by polypeptide chains in water solution are shortly presented and critically discussed. The theory treats the unfolded state of a peptide as "random coil" — an ideal conformation quite distant from reality. We suggest that for this reason the helix propagation parameters of amino-acid residues, determined using series of model peptides with different sequential patterns, are not the same. Interpretation of the so called "nucleation parameter" is erroneous. In fact, it is not determined by the helix nucleation process but rather by a specific situation of residues at the helix N- and C-termini, and it strongly depends on solvation of their NH and CO groups, respectively. Consequently, helical segments with terminal sequences dominated by residues with strongly hydrophobic, bulky side chains can be very unstable. We postulate that an unexpectedly high stability of very short, pre-nucleated helices studied by us arises from a "helix end separation effect": separated helix termini are better solvated than when they overlap each other. Because of this effect, helix initiation may be much more difficult than predicted by the theoretical "helix nucleation parameters".

10

Munch-Kargol model of phloemic transport - two-port representation

75%

Suchanek G., Przestalski S.

Biophysics of Membrane Transport

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1994

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tom 12

|

nr 2

11

The hydrophobic effect: thermodynamics of micelle formation

75%

Fisicaro E.

Biophysics of Membrane Transport

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1992

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tom 11

|

nr 1

12

Haman's inspiration concerning new mechanics of three-phase media

75%

Konstankiewicz K., Pukos A.

International Agrophysics

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1993

|

tom 07

|

nr 1

13

Some thermodynamic aspects of the As-sulphosalt mineralization of the Fore-Sudetic Copper Deposit, SW Poland

75%

Jasinski A. W.

Bulletin of the Polish Academy of Sciences. Earth Sciences

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1993

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tom 41

|

nr 2

14

Thermodynamic steam traps used in the wood industry

63%

Cyrankowski M., Osipiuk J., Wilkowski J., Lapinski J.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2014

|

tom 88

"Thermodynamic steam traps used in the wood industry". We use three big families of demountable steam traps in the wood industry - mechanical steam traps with closed or open float, thermodynamic and thermostatic steam traps. In addition to these families dismountable steam traps have appeared on the market. They are produced in thermostatic and mechanical float versions. For heating devices, in which we have to deal with heat load, changing in the wide broad, which may lead to suspension of the condensate, we use pumping steam traps combining the features of float steam traps and portion pump. Using appropriate steam trap selection criteria, we are able to eliminate energy loss due to steam loss.

15

Interaction of anesthetic supplement thiopental with human serum albumin

63%

Khan S. N., Islam B., Rajeswari M. R., Usmani H., Khan A. U.

Acta Biochimica Polonica

|

2008

|

tom 55

|

nr 2

399-409

Thiopental (TPL) is a commonly used barbiturate anesthetic. Its binding with human serum albumin (HSA) was studied to explore the anesthetic-induced protein dysfunction. The basic binding interaction was studied by UV-absorption and fluorescence spectroscopy. An increase in the binding affinity (K) and in the number of binding sites (n) with the increasing albumin concentration was observed. The interaction was conformation-dependent and the highest for the F isomer of HSA, which implicates its slow elimination. The mode of binding was characterized using various thermodynamic parameters. Domain II of HSA was found to possess a high affinity binding site for TPL. The effect of micro-metal ions on the binding affinity was also investigated. The molecular distance, r, between donor (HSA) and acceptor (TPL) was estimated by fluorescence resonance energy transfer (FRET). Correlation between the stability of the TPL-N and TPL-F complexes and drug distribution is discussed. The structural changes in the protein investigated by circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy reflect perturbation of the albumin molecule and provide an explanation for the heterogeneity of action of this anesthetic.

16

Model of turbo-charging with pulse supply of turbine

63%

Danilecki K.

Teka Komisji Motoryzacji i Energetyki Rolnictwa

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2008

|

tom 08

17

Thermodynamics of irreversible plant cell growth

63%

Pietruszka M., Lewicka S., Pazurkiewicz-Kocot K.

Acta Societatis Botanicorum Poloniae

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2006

|

tom 75

|

nr 3

183-190

The time-irreversible cell enlargement of plant cells at a constant temperature results from two independent physical processes, e.g. water absorption and cell wall yielding. In such a model cell growth starts with reduction in wall stress because of irreversible extension of the wall. The water absorption and physical expansion are spontaneous consequences of this initial modification of the cell wall (the juvenile cell vacuolate, takes up water and expands). In this model the irreversible aspect of growth arises from the extension of the cell wall. Such theory expressed quantitatively by time-dependent growth equation was elaborated by Lockhart in the 60's.The growth equation omit however a very important factor, namely the environmental temperature at which the plant cells grow. In this paper we put forward a simple phenomenological model which introduces into the growth equation the notion of temperature. Moreover, we introduce into the modified growth equation the possible influence of external growth stimulator or inhibitor (phytohormones or abiotic factors). In the presence of such external perturbations two possible theoretical solutions have been found: the linear reaction to the application of growth hormones/abiotic factors and the non-linear one. Both solutions reflect and predict two different experimental conditions, respectively (growth at constant or increasing concentration of stimulator/inhibitor). The non-linear solution reflects a common situation interesting from an environmental pollution point of view e.g. the influence of increasing (with time) concentration of toxins on plant growth. Having obtained temperature modified growth equations we can draw further qualitative and, especially, quantitative conclusions about the mechanical properties of the cell wall itself. This also concerns a new and interesting result obtained in our model: We have calculated the magnitude of the cell wall yielding coefficient (T) [m3 J-1•s-1] in function of temperature which has acquired reasonable numerical value throughout.

18

Impact of short- and long-term agricultural use of chernozem on its quality indicators

63%

Balashov E., Buchkina N., Buchkina N.

International Agrophysics

|

2011

|

tom 25

|

nr 1

19

Mg2plus does not induce isomerization of the open transcription complex of Escherichia coli RNA polymerase at the model Pa promoter bearing consensus -10 and -35 hexamers

63%

Kolasa I. K., Lozinski T., Wierzchowski K. L.

Acta Biochimica Polonica

|

2001

|

tom 48

|

nr 4

The kinetics and thermodynamics of the formation of the transcriptional open complex (RPo) by Escherichia coli RNA polymerase at the synthetic Pa promoter bearing consensus -10 and -35 recognition hexamers were studied in vitro. Previously, this promoter was used as a control one in studies on the effect of DNA bending by An • Tn sequences on transcription initiation and shown to be fully functional in E. coli (Łoziński et al., 1991, Nucleic Acids Res. 19, 2947; Łoziński & Wierzchowski, 1996, Acta Biochim. Polon. 43, 265). The data now obtained demonstrate that the mechanism of Pa-RPo formation and dissociation conforms to the three-step reaction model: bind-nucleate-melt, commonly accepted for natural promoters. Measurements of the dissociation rate constant of Pa-RPo as a function of MgCl2 concentration allowed us to determine the number of Mg2+ ions, nMg ~ 4, being bound to the RPo in the course of renaturation of the melted DNA region. This number was found constant in the temperature range of 25-37°C, which indicates that under these conditions the complex remaines fully open. This observation, taken together with the recent evidence from KMnO4 footprinting studies that the length of the melted region in Pa-RPo at 37°C is independent of the presence of Mg2+ ions (Łoziński & Wierzchowski, 2001, Acta Biochim. Polon. 48, 495), testifies that binding of Mg2+ to RPo does not induce its further isomerization, which has been postulated for the λPr-RPo complex (Suh et al., 1992, Biochemistry 31, 7815; 1993, Science 259, 358).

20

Ratchets, molecular motors, and noise-induced transport

63%

Luczka J.

Cellular and Molecular Biology Letters

|

1996

|

tom 01

|

nr 3

The Feynman ratchet and pawl machine is presented to illustrate some implications of the Second Law of thermodynamics and to demonstrate how the useful work can be extracted from fluctuations. Molecular motors moving along microtubules and responsible for transporting vesicles, organelles and other substances in cells are described in terms of Brownian ratchets driven by non-equilibrium fluctuations of the ATP cycles. Models of non-thermal fluctuations are presented and used for showing the noise-induced transport phenomena in spatially periodic structures.

Ograniczanie wyników

Elements of thermodynamics in RNA evolution

Diagonal [canonical] form of the dissipation function

Amphiphilic counterion effect on gell-fluid phase transition of lipid bilayers

Geochemical aspects of gold occurrence in the Fore-Sudetic Copper Deposit

The thermodynamics of biomolecular sequences

Termodinamicheskaja vozmozhnost' povyshenija ehffektivnocti DVS

Obosnovanie processa kondicionirovanija vozdukha s ispol'zovaniem sistemy recirkuljacii pri proizvodstve soloda

Investigation of the kinetics of the development of the distribution

Helix-coil transition theories. Are they correct?

Munch-Kargol model of phloemic transport - two-port representation

The hydrophobic effect: thermodynamics of micelle formation

Haman's inspiration concerning new mechanics of three-phase media

Some thermodynamic aspects of the As-sulphosalt mineralization of the Fore-Sudetic Copper Deposit, SW Poland

Thermodynamic steam traps used in the wood industry

Interaction of anesthetic supplement thiopental with human serum albumin

Model of turbo-charging with pulse supply of turbine

Thermodynamics of irreversible plant cell growth

Impact of short- and long-term agricultural use of chernozem on its quality indicators

Mg2plus does not induce isomerization of the open transcription complex of Escherichia coli RNA polymerase at the model Pa promoter bearing consensus -10 and -35 hexamers

Ratchets, molecular motors, and noise-induced transport