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1.
J Phys Condens Matter ; 29(18): 185402, 2017 May 10.
Article in English | MEDLINE | ID: mdl-28272023

ABSTRACT

Elastic moduli, hardness (both at room temperature) and thermal expansion (4.2-670 K) have been experimentally determined for polycrystalline CePt3Si and its prototype compound CePt3B as well as for single-crystalline CePt3Si. Resonant ultrasound spectroscopy was used to determine elastic properties (Young's modulus E and Poisson's ratio ν) via the eigenfrequencies of the sample and the knowledge of sample mass and dimensions. Bulk and shear moduli were calculated from E and ν, and the respective Debye temperatures were derived. In addition, ab initio DFT calculations were carried out for both compounds. A comparison of parameters evaluated from DFT with those of experiments revealed, in general, satisfactory agreement. Positive and negative thermal expansion values obtained from CePt3Si single crystal data are fairly well explained in terms of the crystalline electric field model, using CEF parameters derived recently from inelastic neutron scattering. DFT calculations, in addition, demonstrate that the atomic vibrations keep almost unaffected by the antisymmetric spin-orbit coupling present in systems with crystal structures having no inversion symmetry. This is opposite to electronic properties, where the antisymmetric spin-orbit interaction has shown to distinctly influence features like the superconducting condensate of CePt3Si.

2.
Acta Crystallogr E Crystallogr Commun ; 71(Pt 12): m240-1, 2015 Dec 01.
Article in English | MEDLINE | ID: mdl-26870444

ABSTRACT

In the structure of the title compound, [Zn(C8H6NO4)2(C3H10N2)2], the Zn(II) atom is located on a center of symmetry with one independent Zn-O distance of 2.199 (2) Å, and two Zn-N distances of 2.157 (2) and 2.144 (2) Å. The overall coordination geometry around the Zn(II) atom is octa-hedral. Several types of hydrogen-bonding inter-actions are evident. Both intra-molecular [2.959 (3) Å] and inter-molecular [3.118 (3) and 3.124 (3) Šinter-actions occur between the O atoms of the acetate group and the amino N atoms, and weak inter-molecular C-H-O inter-actions involving the nitro groups, leading to an extended chain of the molecules aligned along the ac plane.

3.
J Phys Condens Matter ; 24(36): 365801, 2012 Sep 12.
Article in English | MEDLINE | ID: mdl-22892902

ABSTRACT

Results of first-principles calculations of the Fe/GaAs/Ag(001) epitaxial tunnel junctions reveal that hybridization of interface resonances formed at both interfaces can enhance the tunnelling anisotropic magnetoresistance (TAMR) of the systems. This mechanism is manifested by a non-monotonic dependence of the TAMR effect on the thickness of the tunnel barrier, with a maximum for intermediate thicknesses. A detailed scan of k([parallel])-resolved transmissions over the two-dimensional Brillouin zone proves an interplay between a few hybridization-induced hot spots and a contribution to the tunnelling from the vicinity of the Γ[combining overline] point. This interpretation is supported by calculated properties of a simple tight-binding model of the junction, which reproduce qualitatively most of the features of the first-principles theory.

4.
Vnitr Lek ; 57(5): 491-5, 2011 May.
Article in Czech | MEDLINE | ID: mdl-21695930

ABSTRACT

Therapeutic hypothermia is currently recommended neuroprotective therapeutic measure for comatose patients after cardiac arrest. Hypothermia has been proven not only to affect the neurological outcomes but also the survival of patients after cardiac arrest. This communication summarizes the issue of early infectious complications in patients after cardiac arrest undergoing therapeutic hypothermia. Diagnosis of infectious events is complicated in patients after cardiac arrest not only by the physiological effects of therapeutic hypothermia but also by the consequences of reperfusion injury and development of postresuscitation disease associated with systemic inflammatory response syndrome. Furthermore, there are discussed limited diagnostic options of infectious complications. The significance of the usual symptoms of infections is reduced, as well as the value of laboratory markers such as procalcitonin and C-reactive protein. Finally, the possibility of antibiotic treatment and eventual antibiotic prophylaxis during therapeutic hypothermia in patients after cardiac arrest outside hospitals is mentioned.


Subject(s)
Cardiopulmonary Resuscitation/adverse effects , Heart Arrest/therapy , Hypothermia, Induced/adverse effects , Infections/etiology , Antibiotic Prophylaxis , Humans , Infections/diagnosis , Infections/immunology , Risk Factors
5.
J Int Med Res ; 39(2): 629-36, 2011.
Article in English | MEDLINE | ID: mdl-21672368

ABSTRACT

This study evaluated inflammatory, coagulation and microvascular responses to a continuous 24-h work day in 13 healthy intensive care physicians. Inflammatory markers (interleukin [IL]-2, IL-6, IL-10, tumour necrosis factor-α, matrix metalloproteinase [MMP]-9 and adiponectin), adhesion molecules (vascular cellular adhesion molecule-1 and intercellular adhesion molecule-1 [ICAM-1]), coagulation parameters (thrombin-anti thrombin, von Willebrand factor and tissue factor) and sublingual micro circulation were assessed before and after a 24-h work shift. The 24-h work shift had no effect on inflammatory markers and ICAM-1. Direct visualization of micro-circulation did not reveal stress-related perfusion abnormalities. A 24-h work shift in the intensive care unit was associated with significantly increased plasma levels of tissue factor - a potentially important mechanism linking acute job strain, haemostasis and atherosclerosis. The long-term consequences warrant further evaluation.


Subject(s)
Biological Phenomena , Health Personnel , Health , Intensive Care Units , Stress, Physiological , Adult , Biomarkers/blood , Endothelium, Vascular/physiopathology , Female , Hemodynamics , Hemostasis , Humans , Inflammation Mediators/metabolism , Male , Microcirculation , Thromboplastin/metabolism , Time Factors
6.
Physiol Res ; 60(3): 531-40, 2011.
Article in English | MEDLINE | ID: mdl-21401302

ABSTRACT

Vasoactive intestinal peptide (VIP) is a neuropeptide released from the autonomic nerves exerting multiple antiinflammatory effects. The aim of the present study was to investigate the impact of severe sepsis and hemofiltration in two settings on plasma and tissue concentrations of VIP in a porcine model of sepsis. Thirty-two pigs were divided into 5 groups: 1) control group; 2) control group with conventional hemofiltration; 3) septic group; 4) septic group with conventional hemofiltration; 5) septic group with high-volume hemofiltration. Sepsis induced by faecal peritonitis continued for 22 hours. Hemofiltration was applied for the last 10 hours. Hemodynamic, inflammatory and oxidative stress parameters (heart rate, mean arterial pressure, cardiac output, systemic vascular resistance, plasma concentrations of tumor necrosis factor-alpha, interleukin-6, thiobarbituric acid reactive species, nitrate + nitrite, asymmetric dimethylarginine) and the systemic VIP concentrations were measured before faeces inoculation and at 12 and 22 hours of peritonitis. VIP tissue levels were determined in the left ventricle, mesenteric and coronary arteries. Sepsis induced significant increases in VIP concentrations in the plasma and mesenteric artery, but it decreased peptide levels in the coronary artery. Hemofiltration in both settings reduced concentrations of VIP in the mesenteric artery. In severe sepsis, VIP seems to be rapidly depleted from the coronary artery and, on the other hand, upregulated in the mesenteric artery. Hemofiltration in both settings has a tendency to drain away these upregulated tissue stores which could result in the limited secretory capacity of the peptide.


Subject(s)
Hemofiltration , Peritonitis/complications , Sepsis/metabolism , Vasoactive Intestinal Peptide/metabolism , Animals , Coronary Vessels/metabolism , Female , Male , Mesenteric Arteries/metabolism , Oxidative Stress , Sepsis/etiology , Sepsis/physiopathology , Swine , Vasoactive Intestinal Peptide/blood , Vasoactive Intestinal Peptide/genetics
7.
Vnitr Lek ; 57(1): 72-7, 2011 Jan.
Article in Czech | MEDLINE | ID: mdl-21351665

ABSTRACT

INTRODUCTION AND AIMS: Therapeutic hypothermia is a standard part of post-resuscitation care. Here we present cohort patients after non-traumatic cardiac arrest and their neurological outcomes who underwent 12 hours of therapeutic hypothermia. Moreover, we focused on examining the results of particular subgroup of patients with initial ventricular fibrillation (VF) with acute myocardial infarction with ST-elevation (STEMI) who underwent coronary intervention (PCI). METHODS: We evaluated retrospectively the patients with non-traumatic out-of- and in-hospital cardiac arrest (IHCA, OHCA), admitted to our intensive care unit (ICU) in 2006-2009. Therapeutic hypothermia was induced in all patients with persistent coma after restoration of spontaneous circulation (ROSC). We maintained the target temperature (32-34 degrees C) for 12 hours. Then, passive rewarming followed. Intravascular cooling device was not used. A good neurological outcome was considered to be cerebral performance category (CPC) 1 or 2 at hospital discharge. RESULTS: Total number of patients was 88 (OHCA n = 63; IHCA n = 25), average age 58 (+/- 16) years, average APACHE II was 29 (+/- 6). Men were in 65%. Target temperature was achieved and maintained in 76% of patients. ICU mortality was 32%, hospital mortality 53%. Initial ECG rhythm was VF in 59%, asystoly in 32% and pulsless electrical activity in 9%. Coronary angiography was performed in 57% and PCI in 42% patients. We did not observe severe arrhythmias, minor gastrointestinal bleeding occurred in 2%. The infectious complications were recorded: early pneumonia in 7%, tracheobronchitis in 10% and bacteraemia in 1% patients. In the group of 23 patients with VF/STEMI/PCI target temperature was achieved and maintained in 91%, ICU and hospital survival rates were 87% and 78%. CPC 1 and 2 was observed in 83% among survivors (n = 15). CONCLUSIONS: We achieved similar results in patients after non-traumatic cardiac arrest who underwent a protocol with 12 hours of therapeutic hypothermia as in studies reporting 24 hours of hypothermia, particularly in patients with VF/STEMI/PCI. Twelve hours of therapeutic hypothermia was associated with a low incidence of infectious complications.


Subject(s)
Heart Arrest/therapy , Hypothermia, Induced , Female , Heart Arrest/diagnostic imaging , Humans , Hypothermia, Induced/adverse effects , Hypothermia, Induced/methods , Male , Middle Aged , Radiography
8.
Physiol Res ; 59(6): 859-869, 2010.
Article in English | MEDLINE | ID: mdl-20533855

ABSTRACT

The kidney is a common "victim organ" of various insults in critically ill patients. Sepsis and septic shock are the dominant causes of acute kidney injury, accounting for nearly 50 % of episodes of acute renal failure. Despite our substantial progress in the understanding of mechanisms involved in septic acute kidney injury there is still a huge pool of questions preclusive of the development of effective therapeutic strategies. This review briefly summarizes our current knowledge of pathophysiological mechanisms of septic acute kidney injury focusing on hemodynamic alterations, peritubular dysfunction, role of inflammatory mediators and nitric oxide, mitochondrial dysfunction and structural changes. Role of proteomics, new promising laboratory method, is mentioned.


Subject(s)
Acute Kidney Injury/etiology , Shock, Septic/etiology , Animals , Apoptosis , Humans , Inflammation/metabolism , Nitric Oxide/metabolism , Proteomics/methods , Renal Circulation/physiology
9.
Vnitr Lek ; 55(10): 991-4, 2009 Oct.
Article in Czech | MEDLINE | ID: mdl-19947245

ABSTRACT

A 24-year-old man presented with cough, sore throat, fever, maculopapulous exanthema, pericardial and pleural effusion. Despite extensive evaluation neither infectious, autoimmune, hematological nor oncological disorders were revealed. Broad spectrum antibiotic and subsequently corticosteroid treatment failed to resolve the symptoms. Multiorgan failure with rapid progress of acute respiratory distress syndrome and circulatory failure developed and patient died. Adult onset Still's disease (AOSD), a diagnosis considered in this patient, is a rare disease with unknown prevalence, pathogenesis and etiology. Clinically it is characterized by spiking fever, arthritis, rash, and impairment of multiple organs. There is no single diagnostic test for AOSD. Rather, the diagnosis is based on the clinical criteria and requires the exclusion of infectious, neoplastic, and other autoimmune diseases. Rarely the course of the disease can be rapidly progressive to death. Treatment includes the use of non-steroid antirheumatic drugs and corticosteroids. Limited data suggest that biological agents (e.g. anti-TNF-alpha, anti-IL-1), rituximab or intravenous immunoglobulins might be promising for the treatment of severe cases.


Subject(s)
Fever/etiology , Multiple Organ Failure/complications , Respiratory Distress Syndrome/complications , Still's Disease, Adult-Onset/diagnosis , Adult , Disease Progression , Fatal Outcome , Humans , Male , Young Adult
10.
Bratisl Lek Listy ; 110(8): 447-53, 2009.
Article in English | MEDLINE | ID: mdl-19750979

ABSTRACT

THE AIM OF STUDY: The limits of liver surgery are restricted today by the functional reserves of remnant parenchyma. The aim of this article was to acquaint the general surgical and medical public with the results of experimental liver regeneration stimulated by cytokines and thus to enhance their effort to carry on with implementing the research results in clinical practice. METHODS: Authors present their experimental model of liver regeneration after ligation of portal branches for caudate and right lateral, and right medial liver lobes. The regeneration was induced by application of TNF-alpha and IL-6 into the non-occluded portal branches, and compared with the results of other experimental teams. RESULTS AND CONCLUSION: The absolute volume of hypertrophic lobes increases after application of TNF-alpha more rapidly, whereas in the control group, practically no changes were recorded in hypertrophic liver lobes volumes in first three days. The achieved acceleration of growth of hypertrophic liver lobes after application of TNF-alpha and IL-6 confirmed the key role of studied pleiotropic cytokines in the priming of liver parenchyma regeneration after portal vein ligation (Fig. 3, Ref. 26).


Subject(s)
Cytokines/blood , Liver Regeneration/physiology , Animals , Interleukin-6/blood , Interleukin-6/pharmacology , Ligation , Liver/blood supply , Liver Regeneration/drug effects , Portal Vein/surgery , Recombinant Proteins/pharmacology , Swine , Tumor Necrosis Factor-alpha/blood , Tumor Necrosis Factor-alpha/pharmacology
12.
Vnitr Lek ; 54(11): 1106-10, 2008 Nov.
Article in Czech | MEDLINE | ID: mdl-19069686

ABSTRACT

We present a case report of a 59-year-old man with a history of arterial hypertension and excision of malignant melanoma. He was admitted to the hospital because of two months history of diarrhoea, weight loss and circulatory collapse. In addition, the patient suffered from marked vegetative instability with symptomatic hypotension, polyneuropathy and progression of renal insufficiency, without proteinuria. Complex examination did not reveal neoplasms, endocrine, autoimmune, infectious or neurodegenerative disorders. A serial biopsy of colon failed to provide a clue to the diagnosis. However, AA amyloidosis was found on the kidney biopsy. Neither chronic inflammation nor malignancy was revealed and, hence, no causal treatment could have been established. The patient died from multiple organ failure. The autopsy confirmed systemic AA amyloidosis. The triad consisting ofdiarrhoea, polyneuropathy and hypotension should rise the suspicion on amyloidosis.


Subject(s)
Amyloidosis/diagnosis , Diarrhea/complications , Hypotension/complications , Polyneuropathies/complications , Amyloidosis/complications , Amyloidosis/pathology , Female , Humans , Middle Aged
13.
Vnitr Lek ; 54(10): 1000-5, 2008 Oct.
Article in Czech | MEDLINE | ID: mdl-19009768

ABSTRACT

Sepsis is the leading cause of mortality in non-coronary intensive care units. The uncontrolled and deregulated systemic inflammatory response to infection plays a central role in the pathophysiology of sepsis. This response is mediated by a broad spectrum of endogenous mediators leading to dysfunction in multiple organs remote from the primary infectious site. The failure of numerous clinical trials aimed at eliminating a single mediator stimulated the research to focus on non-selective removal of excessively produced mediators of sepsis. This "detoxification" forms the theoretical basis and biological rationale for the use of hemopurification therapies as an adjunctive treatment of sepsis. Our article reviews the current evidence of hemopurification methods in the supportive treatment of sepsis, briefly discusses new trends and summarizes the recommendations for clinical practice.


Subject(s)
Hemofiltration , Sepsis/therapy , Hemodiafiltration , Humans , Renal Replacement Therapy , Systemic Inflammatory Response Syndrome/therapy
14.
Cas Lek Cesk ; 147(10): 516-20, 2008.
Article in Czech | MEDLINE | ID: mdl-19177733

ABSTRACT

BACKGROUND: Enteral nutrition (EN) represents a preferred type of nutritional support in critical care patients, in spite of the high incidence of intolerance. One of the methods which can speed up the delivery of adequate amounts of food is to switch from the gastric to post-pyloric feeding. A three-luminal tube (TLT) enables post-pyloric enteral feeding with accompanying gastric decompression. The aim of our study was to evaluate effectiveness and safety of the endoscopically introduced TLT along with the estimation of the adequate dose of enteral nutrition. METHODS AND RESULTS: Retrospective analysis of 111 critical care patients with 140 introduced TLT during 2003 to 2006 in two intensive care units (UIC) in the Teaching hospital in Plzen included patients of average age 54 years (+/- 15), APACHE II score 26 (+/- 10) and UIC mortality was 24%. Eight introductions were technically not successful (6%). Reintroduction of the tube was necessary in 21 patients (19%). The average time of tube introduction was 6 minutes (+/- 3). In direct relation to endoscopy no serious complication was observed. In our cohort, 34 ventilator-associated pneumonias developed (31%). Average time interval since the admission to the hospital till TLT introduction was 7 days (+/- 6). Evaluation of a subgroup of 77 patients from one UIC has shown that the adequate amount of EN was achieved in 82% of patients in 4 days (+/- 3) after the TLT introduction. In average, TLT was introduced for 11 days (+/- 7). CONCLUSIONS: Endoscopic TLT introduction represents a safe and reliable method which can ensure adequate amount of enteral nutrition in majority of critical care patients with gastrointestinal dysfunction. In our conditions, TLT is probably not sufficiently used.


Subject(s)
Critical Care , Enteral Nutrition , Intubation, Gastrointestinal/instrumentation , APACHE , Endoscopy, Gastrointestinal , Female , Humans , Male , Middle Aged
15.
Rev. bras. anal. clin ; 23(3): 59-62, 1991. tab, ilus
Article in Portuguese | LILACS | ID: lil-119556

ABSTRACT

Duzentos e trinta e uma amostras fecais,coletadas durante o periodo de julho de 1984 a julho de 1988, originarias de crianças de um mes a cinco anos de idade, acometidas de diarreia aguda, foram analisadas atraves de microscopia eletronica (ME), ensaio imunoenzimatico (IE), eletroforese em gel de poliacrilamida (EGPA) do RNA viral e aglutinaçao do latex (AL), a fim de se comparar a sensibilidade e a importancia das tecnicas usadas. Constatou-se que do total, 47 amostras (47/231, 20,3%)foram consideradas positivas para rotavirus por pelo menos uma tecnica, 32 amostras detectadas por ME (32/47,68,0%); 31 amostras por EGPA (31/47, 65,9%), 31 por IE (31/47,65,9%) e 30 amostras por AL (30/47,63,8%). Dezoito amostras (18/47,38,2%) foram positivas pelas quatro tecnicas, nove amostras (9/47,19,1%) positivas por tres tecnicas, sete amostras (7/47, 14,8%) positivas por duas tecnicas e 184 amostras (l84/231,79,6%) negativas pelas quatro tecnicas. A concordancia entre as quatro tecnicas foi de 87,4% (202/231). A analise estatistica (Teste de McNemar) entre os resultados dos testes em que se detectou maior diferença de positividade,i.e., ME x AL, mostrou nao haver diferença significativa na sensibilidade dos metodos utilizados (P>0,5).


Subject(s)
Humans , Female , Male , Infant, Newborn , Infant , Child, Preschool , Electrophoresis, Polyacrylamide Gel , Immunoenzyme Techniques , Latex Fixation Tests , Rotavirus/analysis , Brazil
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