1,651 research outputs found
Serum inflammatory markers as predictors of neurological status in patients with stroke in the course of hypertension: a two-center study
Introduction. Every year, 60.000 people have stroke incidents in Poland. Despite the fact that it can be prevented, stroke remains the leading cause of morbidity and mortality worldwide. Hypertension is one of the leading risk factors for the stroke incident. The aim was to assess the relationship between inflammatory markers and clinical status of hypertensive patients with the stroke.
Material and methods. 713 patients with stroke in the course of hypertension from the Departments of Neurology in Bytom and Zabrze were enrolled in the retrospective study. They were divided into groups: N1, R1 (with improvement in NIHSS and Rankin results, respectively) and N2, R2 (with deterioration or no changes in NIHSS and Rankin between the day of admission and discharge).
Results. The majority of patients were females [%] (51.5 vs 48.5). Women were significantly older than man [years] (78.0 vs 69.0, P = 0.001, respectively) and had higher NIHSS results at admission [points] (6.0 vs 5.0, P = 0.001, respectively). There were significant differences in the serum CRP [mg/l] (4.75 vs 9.40, P = 0.001) and WBC [103/μL] (8.58 vs 9.02, P = 0.006) between N1 and N2, respectively and between R1 and R2: WBC (8.50 vs 9.00, P = 0.006) and CRP (4.20 vs 8.70, P = 0.001), respectively. A significant correlation between CRP and NIHSS on admission was observed (R = 0.191, P < 0.05). NIHSS and Rankin score on admission were correlated with age (R = 0.212, and R = 0.231, P < 0.05, respectively). CRP was related with the volume [cm3] of lesions in CT (R = 0.170, P < 0.05).
Conclusions. Inflammation seems to be associated with the worse neurological status of patients with stroke and hypertension. Age and sex affect the clinical course of stroke. CRP may indicate the size of changes in CT
Повторный гидравлический разрыв пласта в горизонтальных скважинах с нецементируемым хвостовиком
Myocardial perfusion imaging with 99mTc-tetrofosmin is based on the assumption of a linear correlation between myocardial blood flow (MBF) and tracer uptake. However, it is known that 99mTc-tetrofosmin uptake is directly related to energy-depen-dent transport processes, such as Na/H ion channel activity, as well as cellular and mitochondrial membrane potentials. Therefore, cellular alterations that affect these energy-depen-dent transport processes ought to influence 99mTc-tetrofosmin uptake independently of blood flow. Because metabolism (18F-FDG)–perfusion (99mTc-tetrofosmin) mismatch myocardium (MPMM) reflects impaired but viable myocardium showing cel-lular alterations, MPMM was chosen to quantify the blood flow– independent effect of cellular alterations on 99mTc-tetrofosmin uptake. Therefore, we compared microsphere-equivalent MBF (MBF_micr; 15O-water PET) and 99mTc-tetrofosmin uptake i
A Computational Approach for Designing Tiger Corridors in India
Wildlife corridors are components of landscapes, which facilitate the
movement of organisms and processes between intact habitat areas, and thus
provide connectivity between the habitats within the landscapes. Corridors are
thus regions within a given landscape that connect fragmented habitat patches
within the landscape. The major concern of designing corridors as a
conservation strategy is primarily to counter, and to the extent possible,
mitigate the effects of habitat fragmentation and loss on the biodiversity of
the landscape, as well as support continuance of land use for essential local
and global economic activities in the region of reference. In this paper, we
use game theory, graph theory, membership functions and chain code algorithm to
model and design a set of wildlife corridors with tiger (Panthera tigris
tigris) as the focal species. We identify the parameters which would affect the
tiger population in a landscape complex and using the presence of these
identified parameters construct a graph using the habitat patches supporting
tiger presence in the landscape complex as vertices and the possible paths
between them as edges. The passage of tigers through the possible paths have
been modelled as an Assurance game, with tigers as an individual player. The
game is played recursively as the tiger passes through each grid considered for
the model. The iteration causes the tiger to choose the most suitable path
signifying the emergence of adaptability. As a formal explanation of the game,
we model this interaction of tiger with the parameters as deterministic finite
automata, whose transition function is obtained by the game payoff.Comment: 12 pages, 5 figures, 6 tables, NGCT conference 201
Learning and innovative elements of strategy adoption rules expand cooperative network topologies
Cooperation plays a key role in the evolution of complex systems. However,
the level of cooperation extensively varies with the topology of agent networks
in the widely used models of repeated games. Here we show that cooperation
remains rather stable by applying the reinforcement learning strategy adoption
rule, Q-learning on a variety of random, regular, small-word, scale-free and
modular network models in repeated, multi-agent Prisoners Dilemma and Hawk-Dove
games. Furthermore, we found that using the above model systems other long-term
learning strategy adoption rules also promote cooperation, while introducing a
low level of noise (as a model of innovation) to the strategy adoption rules
makes the level of cooperation less dependent on the actual network topology.
Our results demonstrate that long-term learning and random elements in the
strategy adoption rules, when acting together, extend the range of network
topologies enabling the development of cooperation at a wider range of costs
and temptations. These results suggest that a balanced duo of learning and
innovation may help to preserve cooperation during the re-organization of
real-world networks, and may play a prominent role in the evolution of
self-organizing, complex systems.Comment: 14 pages, 3 Figures + a Supplementary Material with 25 pages, 3
Tables, 12 Figures and 116 reference
Scaling Laws in Human Language
Zipf's law on word frequency is observed in English, French, Spanish,
Italian, and so on, yet it does not hold for Chinese, Japanese or Korean
characters. A model for writing process is proposed to explain the above
difference, which takes into account the effects of finite vocabulary size.
Experiments, simulations and analytical solution agree well with each other.
The results show that the frequency distribution follows a power law with
exponent being equal to 1, at which the corresponding Zipf's exponent diverges.
Actually, the distribution obeys exponential form in the Zipf's plot. Deviating
from the Heaps' law, the number of distinct words grows with the text length in
three stages: It grows linearly in the beginning, then turns to a logarithmical
form, and eventually saturates. This work refines previous understanding about
Zipf's law and Heaps' law in language systems.Comment: 6 pages, 4 figure
Homeostatic competition drives tumor growth and metastasis nucleation
We propose a mechanism for tumor growth emphasizing the role of homeostatic
regulation and tissue stability. We show that competition between surface and
bulk effects leads to the existence of a critical size that must be overcome by
metastases to reach macroscopic sizes. This property can qualitatively explain
the observed size distributions of metastases, while size-independent growth
rates cannot account for clinical and experimental data. In addition, it
potentially explains the observed preferential growth of metastases on tissue
surfaces and membranes such as the pleural and peritoneal layers, suggests a
mechanism underlying the seed and soil hypothesis introduced by Stephen Paget
in 1889 and yields realistic values for metastatic inefficiency. We propose a
number of key experiments to test these concepts. The homeostatic pressure as
introduced in this work could constitute a quantitative, experimentally
accessible measure for the metastatic potential of early malignant growths.Comment: 13 pages, 11 figures, to be published in the HFSP Journa
Conservative management versus open reduction and internal fixation for mid-shaft clavicle fractures in adults - The Clavicle Trial: Study protocol for a multicentre randomized controlled trial
Background: Clavicle fractures account for around 4% of all fractures and up to 44% of fractures of the shoulder girdle. Fractures of the middle third (or mid-shaft) account for approximately 80% of all clavicle fractures. Management of this group of fractures is often challenging and the outcome can be unsatisfactory. In particular it is not clear whether surgery produces better outcomes than non-surgical management. Currently there is much variation in the use of surgery and a lack of good quality evidence to inform our decision.Methods/Design: We aim to undertake a multicentre randomised controlled trial evaluating the effectiveness and safety of conservative management versus open reduction and internal fixation for displaced mid-shaft clavicle fractures in adults. Surgical treatment will be performed using the Acumed clavicle fixation system. Conservative management will consist of immobilisation in a sling at the side in internal rotation for 6 weeks or until clinical or radiological union. We aim to recruit 300 patients. These patients will be followed-up for at least 9 months. The primary endpoint will be the rate of non-union at 3 months following treatment. Secondary endpoints will be limb function measured using the Constant-Murley Score and the Disabilities of the Arm, Shoulder and Hand (DASH) Score at 3 and 9 months post-operatively.Discussion: This article presents the protocol for a multicentre randomised controlled trial. It gives extensive details of, and the basis for, the chosen methods, and describes the key measures taken to avoid bias and to ensure validity.Trial Registration: United Kingdom Clinical Research Network ID: 8665. The date of registration of the trial is 07/09/2006. The date the first patient was recruited is 18/12/2007. © 2011 Longo et al; licensee BioMed Central Ltd
The Effects of Serotonin Receptor Antagonists on Contraction and Relaxation Responses Induced by Electrical Stimulation in the Rat Small Intestine
Background: The main source of 5-HT in body is in enterchromafin cells of intestine, different studies mentioned different roles for endogenous 5-HT and receptors involved and it is not clearified the mechanism of action of endogenous 5-HT.
Objectives: To study the role of endogenous 5-HT on modulation of contraction and relaxation responses induced by electrical field stimulation (EFS) in different regions of the rat intestine.
Materials and Methods: Segments taken from the rat duodenum, jejunum, mid and terminal ileum were vertically mounted, connected to a transducer and exposed to EFS with different frequencies in the absence and presence of various inhibitors of enteric mediators i. e. specific 5-HT receptor antagonists.
Results: EFS-induced responses were sensitive to TTX and partly to atropine, indicating a major neuronal involvement and a cholinergic system. Pre-treatment with WAY100635 (a 5-HT1A receptor antagonist) and granisetron up to 10.0 µM, GR113808 (a 5-HT4 receptor antagonist), methysergide and ritanserin up to 1.0 µM, failed to modify responses to EFS inall examined tissues. In the presence of SB258585 1.0 µM (a 5-HT6 receptor antagonist) there was a trend to enhance contraction in the proximal part of the intestine and reduce contraction in the distal part. Pre-treatment with SB269970A 1.0 µM (5-HT7 receptor antagonist) induced a greater contractile response to EFS at 0.4 Hz only in the duodenum.
Conclusions: The application of 5-HT1A, 5-HT2, 5-HT3, 5-HT4, 5-HT6 and 5-HT7 receptor antagonists, applied at concentrations lower than 1.0 µM did not modify the EFS-induced contraction and relaxation responses, whichsuggests the unlikely involvement of endogenous 5-HT in mediating responses to EFS in the described test conditions.
Keywords: Electric Stimulation Therapy; Serotonin 5-HT1 Receptor Antagonists; Intestine, Smal
A thermodynamic unification of jamming
Fragile materials ranging from sand to fire-retardant to toothpaste are able
to exhibit both solid and fluid-like properties across the jamming transition.
Unlike ordinary fusion, systems of grains, foams and colloids jam and cease to
flow under conditions that still remain unknown. Here we quantify jamming via a
thermodynamic approach by accounting for the structural ageing and the
shear-induced compressibility of dry sand. Specifically, the jamming threshold
is defined using a non-thermal temperature that measures the 'fluffiness' of a
granular mixture. The thermodynamic model, casted in terms of pressure,
temperature and free-volume, also successfully predicts the entropic data of
five molecular glasses. Notably, the predicted configurational entropy avoids
the Kauzmann paradox entirely. Without any free parameters, the proposed
equation-of-state also governs the mechanism of shear-banding and the
associated features of shear-softening and thickness-invariance.Comment: 16 pgs double spaced. 4 figure
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