Abstract：
:Lignin, the structural polymer of the plant cell walls, is produced by free radical polymerization of phenolic alcohols, catalyzed by different peroxidases. The mechanism and the structural organization of lignin in the cell have not been completely understood. In this study we applied fractal analysis to images of lignin polymer obtained using scanning tunneling microscope. The analysis showed the regularity of the polymer at different levels of organization. According to the results obtained, at the 95% confidence level, there is no significant difference in the fractal dimension between images representing different organizational levels of lignin. In other words, lignin produced in in vitro conditions has fractal structural organization and, consequently the polymer can be expected to be regular in in vivo conditions. The value of the fractal dimension 1.929 +/- 0.021 is in good agreement with the theoretically predicted value for polyaddition and polycondensation mechanism of polymerization. The mechanism of in vivo lignin synthesis is discussed in terms of various experimental and theoretical evidences. In this paper, we could show that fractal analysis of the lignin polymer is a useful complementary approach to the experimental data collection in structural and phenomenological studies.
journal_name
Gen Physiol Biophysjournal_title
General physiology and biophysicsauthors
Radotić K,Tasić M,Jeremić M,Budimlija Z,Simić-Krstić J,Polzović A,Bozović Zsubject
Has Abstractpub_date
2000-06-01 00:00:00pages
171-80issue
2eissn
0231-5882issn
1338-4325journal_volume
19pub_type
杂志文章abstract：:A possible mechanism is put forward to explain the sliding of thin filaments during muscle contraction. In our model, repulsion due to electrostatic forces is the mechanism which triggers crossbridges to cause the thin filaments to slide. The mechanism proposed could operate regardless of whether the myosin heads rota...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1996-12-01 00:00:00
abstract：:In this study, we investigated the role of AMP-activated protein kinase (AMPK) and the importance of reactive oxygen species (ROS) in apoptosis induction associated with cell cycle arrest induced by sulforaphane in AGS human gastric cancer cells. Our results demonstrated that sulforaphane inhibited proliferation of AG...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2017026
更新日期：2018-03-01 00:00:00
abstract：:Cytochrome P-450 and NADPH: cytochrome P-450 reductase were solubilized by detergents from microsomal fraction of tulip bulbs Tulipa fosteriana L. and purified to electrophoretic homogeneity. The purification was achieved by anion-exchange column chromatography, hydroxyapatite-column chromatography and affinity chroma...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1994-04-01 00:00:00
abstract：:Lidocaine, a use-dependent Na(+) channel blocker, paradoxically evokes neural activation in the slowly adapting stretch receptor organ of crayfish at 5-10 mmol/l concentration. For elucidating the underlying mechanisms of this paradoxical effect, a series of conventional electrophysiological experiments were performed...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2007-03-01 00:00:00
abstract：:Changes in the Young elasticity modulus in perpendicular direction to the membrane surface E perpendicular, in the coefficient of dynamic viscosity eta, in the electric capacitance C, in the surface charge U1, in the conductivity g and in the coefficient of non-linearity beta of current-voltage characteristic caused b...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1987-04-01 00:00:00
abstract：:The capacity of five synthetic analogs of [8-arginine] vasopressin (AVP) to stimulate frog skin sodium transport (natriferic activity) was characterized electrophysiologically using the method of short-circuit current, and compared to that of synthetic AVP. The analogs used were [8-arginine] vasopressins modified in p...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1990-12-01 00:00:00
abstract：:In this study possible connection between radiofrequency exposure (RF) and development of oxidative stress was investigated by measuring impairment in cellular oxidation-reduction balance immediately after RF exposure. Fibroblast cells V79 were exposed for 10, 30 and 60 minutes to 1800 MHz RF radiation. Electric field...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2017007
更新日期：2017-10-01 00:00:00
abstract：:Myosin was isolated from pig atrial and ventricular myocardium during postnatal development and Ca2+-ATPase was determined and myosin light chains were analysed by electrophoresis in sodium dodecylsulfate polyacrylamide gel. During ontogenesis ATPase activity of ventricular myosin remains virtually unchanged, whereas ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1989-02-01 00:00:00
abstract：:The effects of both chronic hypoxia and acute intermittent hypoxia (AIH) on cardiovascular system are unclear. We designed this study to develop a rabbit model of hypertension by exposure to chronic hypobaric hypoxia (CHH) and to investigate the effects of AIH on hypertensive rabbits. Present study was performed in 13...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2013070
更新日期：2014-01-01 00:00:00
abstract：:Recent research has supported a potential role of immune pathology in the etiopathogenesis of schizophrenic. In the CNS various viruses were identified in the brains of schizophrenic patients. Pro-inflammatory cytokines were found to be associated with the stage of disease. Microglial cells were reported to be activat...
journal_title：General physiology and biophysics
pub_type： 杂志文章,评审
doi：
更新日期：2009-01-01 00:00:00
abstract：:It is well known that in vitro storage lesions lead to membrane dysfunction and decreased number of functional erythrocytes. As erythrocytes get older, in storage media as well as in peripheral circulation, they undergo a variety of biochemical changes. In our study, the erythrocytes with different age groups in citra...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2016001
更新日期：2016-07-01 00:00:00
abstract：:This study specified the role of several key calcium-operating ion channels in contraction/relaxation of human detrusor muscle as possible target for overactive bladder (OAB) treatment. Detrusor samples, obtained from 18 males (average age 61.5 ± 5.9 years), were investigated by organ tissue bath method with following...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2017064
更新日期：2018-07-01 00:00:00
abstract：:A number of studies have reported that male reproductive organs are susceptible to electromagnetic fields (EMFs). The aim of this study was to explore the effects of microwave radiation exposures on 6-8 weeks old male Swiss albino mice. Mice were divided into two groups: group I - sham-exposed (Control), and group II ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2017059
更新日期：2018-07-01 00:00:00
abstract：:Effects of six thiol reagents with different physico-chemical properties were tested on the Na+-dependent 45Ca2+ transport into the rat brain microsomal membrane vesicles. The mercurials p-chlormercuribenzoate and Mersalyl effectively inhibited 45Ca2+ uptake with IC50 values in the order of 10(-4) mol X l-1 in the med...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1987-04-01 00:00:00
abstract：:CCAAT/enhancer binding proteins (C/EBP) alpha, -beta and -delta play an important role in mediating I interleukin-6 (IL-6) dependent expression of acute-phase protein (APP) genes in liver during acute-phase (AP) response. Based on the presence of type IL-6 responsive element (IL-6 RE) in the rat haptoglobin (Hp) gene ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2003-06-01 00:00:00
abstract：:Somatostatin analogues are currently used to treat various disorders such as hypersecretion and different neuroendocrine tumors. In this study we examined the effects on the adrenal cortex of somatostatin (SRIH-14) and octreotide administered subcutaneously twice daily for 5 days to adult male rats. Control rats recei...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2008-09-01 00:00:00
abstract：:The membrane lipid and fatty acid compositions of red blood cells from a paramyotonia patient were investigated. Cholesterol and total phospholipid contents in paramyotonia were not different from control. Only the sphingomyelin content was lower, and thus the molar ratio of phosphatidylcholine/sphingomyelin was highe...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1986-04-01 00:00:00
abstract：:The passive mechanical properties of whole muscle in active and nonactive states are compared. The experimental results are presented as stress-strain curves, which are analyzed in the framework of the current theoretical background [viz. the freely-jointed chain model (FJCM) and the worm-like chain model (WLCM)] in a...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1999-06-01 00:00:00
abstract：:Although the A1 adenosine receptor (A1 receptor), the main adenosine receptor type in cardiac muscle, is involved in powerful cardioprotective processes such as ischemic preconditioning, the atrial A1 receptor reserve has not yet been quantified for the direct negative inotropic effect of adenosine. In the present stu...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2013041
更新日期：2013-09-01 00:00:00
abstract：:The effects of thrombin stimulation on megakaryocytopoiesis and pulmonary-platelet interactions were investigated before and after administration of the compound to 15 mongrel dogs. Each dog served as its own control. Thrombin was given to encourage the traffic of megakaryocytes into the lung and to study the thrombin...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1989-12-01 00:00:00
abstract：:For characterization of Na(+),K(+)-ATPase, a key enzyme involved in maintenance of intracellular sodium homeostasis, expression of alpha1 subunit and the ATP- and Na(+)-binding properties were investigated by Western blot analysis and by enzyme kinetics, respectively. Previous studies documented time-dependent alterat...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2010_03_266
更新日期：2010-09-01 00:00:00
abstract：:Pretreatment with diazoxide, mitochondrial K(ATP) channel opener, was found to protect the rat heart against ischemia/reperfusion injury. Our aim was also to characterize the effects of diazoxide on the alterations of regulatory myocardial proteins, on mitochondrial ultrastructure, integrity and induction of apoptotic...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2007-06-01 00:00:00
abstract：:The hormone leptin, by binding to hypothalamic receptors, suppresses food intake and decreases body adiposity. Leptin receptors are also widely expressed in extra-hypothalamic areas such as hippocampus, amygdala and cerebellum, where leptin modulates synaptic transmission. Here we show that a defective leptin receptor...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2013056
更新日期：2014-01-01 00:00:00
abstract：:A simple graphical method is proposed to distinguish between two-state and gradual alterations in DNA conformation from circular dichroic spectra. The method is advantageous particularly to identify two-state conformational isomerizations which exhibit low degree of cooperativity. The usefulness of the method is illus...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1986-08-01 00:00:00
abstract：:Thiamine deficiency (TD) results in lactate acidosis, which is associated with neurodegeneration. The aim of this study was to investigate this alteration in primary rat brain endothelia. Spectrophotometric analysis of culture media revealed that only a higher concentration of pyrithiamine, which accelerates the intra...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2005-12-01 00:00:00
abstract：:The distributions of K, Na, Mg and Ca within frog ovarian and oviductal oocytes were studied by electron probe wavelength dispersive X-ray microanalysis. An important heterogeneity could be found both in nuclear and jelly coated oocytes. The highest K, Mg and, to a lesser extent, Na concentrations were found in the pi...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1985-06-01 00:00:00
abstract：:The activity of different cathepsins and neutral proteinases was measured in normal and vitamin E-deficient rabbit muscles using specific substrates. Among the changes of enzyme activities in dystrophy caused by vitamin E-deficiency the increase in the activity of cathepsin B is the most striking. The activity of cath...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1991-10-01 00:00:00
abstract：:Fasting for 48 h and the same period of recovery induced by 48 h refeeding increased rat hypothalamic monoamine oxidase (MAO) activity. However, in the interscapular brown adipose tissue (IBAT), only refeeding induced a significant elevation of the enzyme activity. As far as hypothalamic antioxidative enzymes are conc...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2000-09-01 00:00:00
abstract：:This study examines the effects of a 2.1-GHz WCDMA-modulated microwave (MW) radiation on apoptotic activity and mitochondrial membrane potential (ΔΨm) in MCF-7 cells. The cells were exposed to the MW at a specific absorption rate (SAR) of 0.528 W/kg for 4 or 24 h. The antiproliferative effect of MW exposure was determ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2016021
更新日期：2017-04-01 00:00:00
abstract：:Quercetin and epigallocatechin gallate are two of the most abundant polyphenols in dietary plants, including apples, onions, red wine and green tea. The bioactivity of polyphenols is linked to their ability to interact with cell membranes without being internalized. The aim of the present study was to assess the short...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2012_005
更新日期：2012-03-01 00:00:00
