Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 253
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Med Virol ; 96(4): e29586, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38587173

RESUMO

Inappropriate sinus tachycardia (IST) is one of the manifestations of the post-COVID-19 syndrome (PCS), which pathogenesis remains largely unknown. This study aimed to identify potential risk factors for IST in individuals with PCS. The 1349 patients with PCS were included into the study. Clinical examination, 24H Holter ECG, 24H ambulatory blood pressure monitoring and biochemical tests were performed 12-16 weeks after the COVID-19 in all participants. IST was found in 69 (3.5%) individuals. In the clinical assessment IST patients were characterized by a higher age (p < 0.001) and lower prevalence of the diagnosed hypertension (p = 0.012), compared to remaining patients. Biochemical testing showed higher serum triglycerides (1.66 vs. 1.31 pmol/L, p = 0.007) and higher prevalence of a low high-density lipoprotein (HDL) cholesterol (24.6% vs. 15.2%, p = 0.035) in the IST group. Subsequently, the triglicerydes (TG)/HDL ratio, an indicator of insulin resistance, was significantly higher in the IST individuals (3.2 vs. 2.4, p = 0.005). 24H monitoring revealed a significantly higher minimum diastolic, maximum systolic and mean arterial blood pressure values in the IST group (p < 0.001 for all), suggesting a high prevalence of undiagnosed hypertension. A multivariate analysis confirmed the predictive value TG/HDL ratio >3 (OR 2.67, p < 0.001) as predictors of IST development. A receiver operating characteristic curve analysis of the relationship between the TG/HDL ratio and the IST risk showed that the predictive cut-off point for this parameter was 2.46 (area under the ROC curve = 0.600, p = 0.004). Based on these findings, one can conclude that insulin resistance seems to be a risk factor of IST, a common component of PCS.


Assuntos
COVID-19 , Hipertensão , Resistência à Insulina , Humanos , Estudos Retrospectivos , Taquicardia Sinusal/diagnóstico , Lipoproteínas HDL , Monitorização Ambulatorial da Pressão Arterial , Síndrome de COVID-19 Pós-Aguda , Triglicerídeos , HDL-Colesterol , Fatores de Risco , Hipertensão/complicações , Hipertensão/epidemiologia
2.
Langenbecks Arch Surg ; 409(1): 195, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38904793

RESUMO

PURPOSE: SASI (single anastomosis sleeve ileal) bypass can lead to nutritional deficiencies, including disorders of iron metabolism and anemia. This study aims to evaluate the effect of SASI bypass on weight loss, anemia, and iron deficiency in patients with obesity during the follow-up period. METHODS: This study is a retrospective analysis of prospectively collected data from patients who underwent SASI bypass at our hospital between January 2020 and February 2022. RESULTS: The mean age of the patients was 42 years (range 22-58). The average duration of the follow-up period was 26 months. The mean percentage of excess weight loss (%EWL) was 90.1%, and total weight loss (%TWL) was 30.5%. During the postoperative observation period, anemia was identified in ten patients (25%), comprising 70% with normocytic anemia, 10% with microcytic anemia, and two macrocytic anemia cases (20%). Iron deficiency was observed in two patients (5%). CONCLUSION: SASI bypass is an effective bariatric procedure in weight loss outcomes. However, there may be an increased risk of anemia and iron metabolism disruptions associated with this procedure. The common limb length (250 vs. 300 cm) did not significantly impact hemoglobin, iron, TIBC, ferritin levels, or anemia incidence among patients undergoing SASI bypass. The decrease in postoperative ferritin levels signifies a depletion in tissue iron reserves, thereby emphasizing the necessity for surveillance of iron homeostasis parameters following SASI bypass.


Assuntos
Íleo , Redução de Peso , Humanos , Adulto , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Íleo/cirurgia , Complicações Pós-Operatórias/etiologia , Obesidade Mórbida/cirurgia , Obesidade Mórbida/complicações , Anemia , Anastomose Cirúrgica , Cirurgia Bariátrica/métodos , Cirurgia Bariátrica/efeitos adversos , Adulto Jovem , Anemia Ferropriva , Ferro/metabolismo , Ferro/sangue
3.
J Med Virol ; 95(12): e29331, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38112151

RESUMO

Clinical evidence indicates that COVID-19 is a multiorgan disease that significantly impacts the cardiovascular system. However, little is known about the predictors of myocardial dysfunction after SARS-CoV-2 infection. Therefore, this research aimed to evaluate the clinical and electrocardiographic correlates of myocardial dysfunction after SARS-CoV-2 infection in nonhospitalised patients without previously diagnosed cardiovascular disease. This observational study included 448 patients selected from the database of 4142 patients in the Polish Long-Covid Cardiovascular study. All patients underwent a 12-lead electrocardiogram (ECG); 24-h Holter ECG monitoring, 24/7 ambulatory blood pressure monitoring, echocardiography, and cardiac magnetic resonance imaging. According to the results of diagnostic tests, patients were divided into two groups depending on the occurrence of myocardial dysfunction after COVID-19. Group 1-without myocardial dysfunction after COVID-19-consisted of 419 patients, with a mean age of 48.82 (SD ± 11.91), and Group 2 (29 patients)-with myocardial dysfunction after COVID-19, with a mean age of 51.45 (SD ± 12.92). When comparing the analysed groups, there were significantly more men in Group 2 (p = 0.006). QRS (corresponds to the time of ventricular contraction in an electrocardiographic examination) fragmentation (p = 0.031), arrhythmias (atrial fibrillation, supraventricular extrasystole, ventricular extrasystole) (p = 0.008), and male gender (p = 0.007) were independently associated with myocardial dysfunction after COVID-19. The study showed that myocardial damage after COVID-19 affects men more often and is independent of typical clinical factors and the severity of the disease course. The QRS fragmentation and arrhythmias observed in the ECG indicate the possibility of myocardial dysfunction in patients after COVID-19, which may be a valuable marker for physicians.


Assuntos
COVID-19 , Cardiomiopatias , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Ambulatorial da Pressão Arterial , COVID-19/complicações , Eletrocardiografia/métodos , Seguimentos , Coração/diagnóstico por imagem , Polônia/epidemiologia , Síndrome de COVID-19 Pós-Aguda , SARS-CoV-2 , Feminino , Adulto
4.
Langenbecks Arch Surg ; 408(1): 84, 2023 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-36773074

RESUMO

INTRODUCTION: The aim of the study is to assess the effect of shortening the excluded loop of the small intestine to 150 cm on the effectiveness of one anastomosis gastric bypass (OAGB) in remission of type 2 diabetes with Io obesity. MATERIAL AND METHODS: The study included 25 patients with a body mass index (BMI) 30-35 kg/m2, with a diagnosis of diabetes mellitus type 2 (T2DM), and undergoing OAGB with excluded 150 cm of the small intestine. RESULTS: There were no deaths in the study group, bleeding during the postoperative period requiring reoperation, anastomotic leakage/leakage throught mechanical stitching. The mean a glycated haemoglobin (HbA1C) level 12 months after surgery was 6.16 ± 0.96%, corresponding to a 2.29 ± 3.3% decrease. In more than 85% of the patients taking insulin before surgery, the insulin was discontinued in the postoperative period. Additionally, the level of glycaemia was assessed in patients on the day of surgery (163 ± 58 mg/dl) and on the day of discharge from the hospital (4.7 ± 1.3 days)-it was lower by over 18% (133 ± 39.2 mg). Over the period of 12 months following OAGB, there was a reduction in the mean BMI value from 33.5 ± 2 to 25.5 ± 2.5 kg/m2 and improvement in lipid parameters and mean values of blood pressure. CONCLUSION: OAGB with excluded 150 cm of the small intestine has beneficial effect on the remission of T2DM in patients with a BMI of 30-35kg/m2 and is associated with an acceptable level of complications. The achieved weight loss after surgery is satisfactory.


Assuntos
Diabetes Mellitus Tipo 2 , Derivação Gástrica , Obesidade Mórbida , Masculino , Humanos , Feminino , Derivação Gástrica/efeitos adversos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/cirurgia , Índice de Massa Corporal , Obesidade Mórbida/cirurgia , Obesidade/complicações , Obesidade/cirurgia , Resultado do Tratamento , Insulina , Estudos Retrospectivos
5.
Pol Merkur Lekarski ; 51(3): 216-220, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37589105

RESUMO

OBJECTIVE: Aim: Determination of factors associated with frailty syndrome (FS) in patients with heart failure (HF). PATIENTS AND METHODS: Materials and methods: Consecutive patients hospitalized in the department were assessed for the presence of FS using L. Fried criteria, Edmonton Frail Scale (EFS) and Tilburg Frailty Indicator (TFI). Presence of arterial hypertension, diabetes, obesity, chronic obstructive pulmonary disease (COPD), and heart failure was included in the analysis based on patients' medical history and findings from current hospitalization. Patients were assessed for the presence of depression using Beck's Depression Inventory (BDI). Physical capacity was assessed using NYHA classification. RESULTS: Results: 87 patients (mean age 81.4±6.7; 57 women; 11 HFrEF, mean NYHA 2.36±1.21; 11 HFmrEF, mean NYHA 2.18±1.08; 65 HFpEF mean NYHA 1.94±1.09) were included in the analysis. Multivariable analysis showed significant relationship between FS assessed with EFS and age (ß=0.316, SE=0.08; p=0.0001), arterial hypertension (ß=-0.194, SE=0.08; p=0.0173), COPD (ß=0.176, SE=0.08; p=0.0300) and depression (ß=0.565, SE=0.08; p=0.0000). FS assessed with L. Fried criteria was significantly related to age (ß=0.359, SE=0.09; p= 0.0001), NYHA classification (ß= 0.336, SE=0.09; p=0.0002) and depression (ß=0.297, SE=0.09; p=0.0010). Age (ß=0.251, SE=0.10; p=0.0114) and depression (ß=0.375, SE=0.1; p=0.0002) were significantly related to FS assessed using TFI. In multivariable analysis HF phenotype was not significantly related to FS. CONCLUSION: Conclusions: Age and depression assessed with BDI are related to FS in patients with HF. Arterial hypertension and COPD are linked to FS assessed using EFS, whereas NYHA classification is linked to FS assessed with L. Fried criteria. No statistically significant relationship was found between FS and HF phenotype.


Assuntos
Fragilidade , Insuficiência Cardíaca , Hipertensão , Doença Pulmonar Obstrutiva Crônica , Feminino , Humanos , Idoso , Fragilidade/epidemiologia , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/epidemiologia , Idoso Fragilizado , Volume Sistólico , Doença Pulmonar Obstrutiva Crônica/complicações
6.
Int J Mol Sci ; 23(17)2022 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-36076952

RESUMO

Atherosclerosis, the underlying cause of coronary artery disease (CAD), has a significant inflammatory component. White blood cell count is an affordable and accessible way to assess the systemic immune response, as it comprises many subgroups with distinct and complex functions. Considering their multidirectional effect on atherosclerosis, new biomarkers integrating various leukocyte subgroups, the Systemic Inflammatory Index (SII) and the Systemic Inflammatory Response Index (SIRI), were recently devised to describe the balance between inflammation and immune reaction. This research aimed to evaluate the relationship of the intensity of inflammation measured by these biomarkers with the severity of CAD assessed with coronary angiography and with the diagnosis of acute coronary syndrome (ACS) or stable CAD in 699 patients. SIRI, but not SII, was associated with the diagnosis, having the highest values for patients with ACS (STEMI), significantly higher than in patients with stable CAD (p < 0.01). The highest SII and SIRI values were observed in patients with three-vessel CAD. SII and SIRI require further in-depth and well-designed research to evaluate their potential in a clinical setting.


Assuntos
Síndrome Coronariana Aguda , Aterosclerose , Doença da Artéria Coronariana , Aterosclerose/complicações , Biomarcadores , Humanos , Inflamação , Síndrome de Resposta Inflamatória Sistêmica
7.
Small ; 17(17): e2007242, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33719216

RESUMO

Lithium-sulfur (Li-S) batteries are considered one of the most promising energy storage technologies, possibly replacing the state-of-the-art lithium-ion (Li-ion) batteries owing to their high energy density, low cost, and eco-compatibility. However, the migration of high-order lithium polysulfides (LiPs) to the lithium surface and the sluggish electrochemical kinetics pose challenges to their commercialization. The interactions between the cathode and LiPs can be enhanced by the doping of the carbon host with heteroatoms, however with relatively low doping content (<10%) in the bulk of the carbon, which can hardly interact with LiPs at the host surface. In this study, the grafting of versatile functional groups with designable properties (e.g., catalytic effects) directly on the surface of the carbon host is proposed to enhance interactions with LiPs. As model systems, benzene groups containing N/O and S/O atoms are vertically grafted and uniformly distributed on the surface of expanded reduced graphene oxide, fostering a stable interface between the cathode and LiPs. The combination of experiments and density functional theory calculations demonstrate improvements in chemical interactions between graphene and LiPs, with an enhancement in the electrochemical kinetics, power, and energy densities.

8.
Chem Rev ; 119(7): 4569-4627, 2019 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-30859816

RESUMO

This review addresses concepts, approaches, tools, and outcomes of multiscale modeling used to design and optimize the current and next generation rechargeable battery cells. Different kinds of multiscale models are discussed and demystified with a particular emphasis on methodological aspects. The outcome is compared both to results of other modeling strategies as well as to the vast pool of experimental data available. Finally, the main challenges remaining and future developments are discussed.

9.
Eur Heart J Suppl ; 23(Suppl B): B124-B127, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34248436

RESUMO

May Measurement Month 2019 is the third edition of a global initiative organized by the International Society of Hypertension aimed at raising awareness of hypertension and the need for blood pressure (BP) screening. We present data analysis from Poland. To evaluate the potential of opportunistic BP measurements as a tool for cardiovascular disease prevention programmes. To collect new country data for further annual comparisons. An opportunistic cross-sectional survey of volunteers aged ≥18 was carried out in 201 sites in May 2019. BP was measured in 7072 subjects (mean age: 54 ± 15 years; 62.3% females). After multiple imputation, the age- and sex-standardized systolic BP (SBP) and diastolic BP (DBP) was 125.4/78.5 mmHg in the whole group, 133.3/82.8 mmHg in individuals on antihypertensive medication and 123.3/77.7 mmHg in those not taking antihypertensive drugs. The proportion of subjects with high BP (≥140/90 mmHg) were 41.8% in subjects taking antihypertensive drugs, and 19.6% in those not taking any antihypertensive drugs. Overall, hypertension was present in 55.4% of participants (3917 out of 7072), of whom 83.0% were aware of their diagnosis. 80.4% of hypertensives were taking antihypertensive medication. 46.7% of all hypertensives had BP controlled to target (<140/90 mmHg). Higher BP correlated with body mass index and age but not tobacco smoking. SBP but not DBP was higher in diabetic participants. These data provide evidence on the current epidemiology of hypertension and may serve as a source of information to introduce primary and secondary prevention programmes to reduce cardiovascular risk in Poland.

10.
Eur Heart J Suppl ; 22(Suppl H): H108-H111, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32884486

RESUMO

Hypertension remains the most important cardiovascular risk factor in Poland. May Measurement Month is a global initiative organized by the International Society of Hypertension aimed at raising awareness of hypertension and the need for blood pressure (BP) screening and demonstrating the potential of the opportunistic BP measurements. An opportunistic cross-sectional survey of volunteers aged ≥18 was carried out in 146 sites in May 2018. Blood pressure was measured in 6450 subjects (mean age: 41 ± 15 years; 59% females). After multiple imputation, the age and sex standardized systolic and diastolic BP was 126.7/78.4 mmHg in the whole analysed group, 132.8/81.3 mmHg in subjects taking antihypertensive drugs, and 125.7/78.0 mmHg in those not taking any antihypertensive drugs. After multiple imputation, the proportions of subjects with high BP (systolic ≥140 mmHg or diastolic ≥90 mmHg or on treatment for raised BP) were 22.2% in the whole analysed group, 39.2% in subjects taking antihypertensive drugs, and 18.6% those not taking any antihypertensive drugs. Overall, hypertension was present in 32.8% of participants, among them 38.7% were not aware of the disease, 53.1% were taking antihypertensive drugs, and 32.3% had BP controlled to target (<140/90 mmHg). Blood pressure was increasing with increasing body mass index and alcohol intake. Smokers and project participants with diabetes had increased average BP. In conclusion, this project provides additional evidence for a considerable potential for further reduction of cardiovascular risk through improvement in detection and treatment of hypertension in Poland.

11.
Angew Chem Int Ed Engl ; 59(28): 11483-11490, 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32220137

RESUMO

The development of multivalent metal (such as Mg and Ca) based battery systems is hindered by lack of suitable cathode chemistry that shows reversible multi-electron redox reactions. Cationic redox centres in the classical cathodes can only afford stepwise single-electron transfer, which are not ideal for multivalent-ion storage. The charge imbalance during multivalent ion insertion might lead to an additional kinetic barrier for ion mobility. Therefore, multivalent battery cathodes only exhibit slope-like voltage profiles with insertion/extraction redox of less than one electron. Taking VS4 as a model material, reversible two-electron redox with cationic-anionic contributions is verified in both rechargeable Mg batteries (RMBs) and rechargeable Ca batteries (RCBs). The corresponding cells exhibit high capacities of >300 mAh g-1 at a current density of 100 mA g-1 in both RMBs and RCBs, resulting in a high energy density of >300 Wh kg-1 for RMBs and >500 Wh kg-1 for RCBs. Mechanistic studies reveal a unique redox activity mainly at anionic sulfides moieties and fast Mg2+ ion diffusion kinetics enabled by the soft structure and flexible electron configuration of VS4 .

12.
Eur Heart J Suppl ; 21(Suppl D): D97-D100, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31043891

RESUMO

Elevated blood pressure (BP) is a worldwide burden, leading to over 10 million deaths yearly. May Measurement Month (MMM) is a global initiative organized by the International Society of Hypertension aimed at raising awareness of hypertension and the need for BP screening. An opportunistic cross-sectional survey of volunteers aged ≥18 was carried out in May 2017. BP measurement, the definition of hypertension and statistical analysis followed the globally approved MMM17 Study Protocol. In Poland 5834 (98.9%, Caucasian) individuals were screened. After multiple imputation, 2601 (35.3%) had hypertension. Of individuals not receiving anti-hypertensive medication, 976 (20.6%) were hypertensive. Of individuals receiving anti-hypertensive medication, 532 (49.1%) had uncontrolled BP. In the crude screened group, 81.4% declared to not receive any anti-hypertensive treatment, while the remaining 18.6% were on such medications. In overweight and obese patients both systolic and diastolic BP were significantly higher than in normal weight and underweight subjects. In addition, BP measured on Sundays was significantly lower than on Mondays. MMM17 was one of the largest recent BP screening campaigns in Poland. We found that over 1/3 of participants were hypertensive. Almost half of the treated subjects had uncontrolled BP. These results suggest that opportunistic screening can identify substantial numbers with raised BP.

13.
COPD ; 16(5-6): 354-361, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31631716

RESUMO

Blood eosinophilia has been proposed as a surrogate marker for airway eosinophilia and as a predictor of treatment response in chronic obstructive pulmonary disease (COPD). The aim of the study was to assess the relationship between blood and sputum eosinophils and to investigate the association between blood and sputum eosinophil count and clinical features of mild-to-moderate COPD. We performed a retrospective analysis of blood and sputum eosinophil count, as well as demographic and lung function data in a cohort of 90 stable, steroid-naive (Global Initiative for Chronic Obstructive Lung Disease 1 or 2) COPD patients and 20 control subjects. Blood and sputum eosinophil count did not correlate both in patients with COPD (r = -0.04 p = 0.705) and in controls (r = 0.05, p = 0.838). Sputum eosinophilia (≥3%) was present in 40% of COPD patients. The median blood eosinophil count in patients with COPD was 180 (interquartile range 90-270)/µL; patients with low blood eosinophils (<180/µL) did not differ from those with high blood eosinophils (≥180/µL) in terms of forced expiratory volume in 1 second, bronchial reversibility or hyperresponsiveness. This was also the case when COPD patients with and without sputum eosinophilia were compared. At the same time, positive bronchial reversibility and positive bronchial hyperresponsiveness were observed in 2 (11%) COPD patients with high blood eosinophils and in 1 (5%) patient with sputum eosinophilia. There was a weak, albeit significant correlation (r = 0.22 p = 0.041) between blood eosinophil count and age in patients with COPD. Peripheral eosinophil count poorly reflects sputum eosinophils and lung function in stable steroid-naive mild-to-moderate COPD patients.


Assuntos
Hiper-Reatividade Brônquica/etiologia , Eosinofilia/etiologia , Eosinófilos/metabolismo , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Adulto , Idoso , Hiper-Reatividade Brônquica/diagnóstico , Estudos de Casos e Controles , Eosinofilia/diagnóstico , Eosinofilia/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/terapia , Testes de Função Respiratória , Estudos Retrospectivos , Índice de Gravidade de Doença , Escarro/metabolismo
14.
Wiad Lek ; 72(3): 472-483, 2019.
Artigo em Polonês | MEDLINE | ID: mdl-31051001

RESUMO

Despite significant improvements in the diagnosis and treatment of cardiovascular diseases that have occurred in recent years, they remain the main cause of morbidity and mortality in the population. In many European countries, the incidence of coronary heart disease is currently 50% lower than it was in the early 1980s, which is the result of cardiovascular prevention. A special group of patients are people after myocardial infarction with very high cardiovascular risk. They should definitely implement activities at the individual level e. g. work on improving the unhealthy lifestyle and pharmacologically control other risk factors. A diet low in saturated fats should be recommended, i.e. mainly containing whole grains, vegetables, fruits and fish, recommend regular physical exercise: 150 min / week of moderate, aerobic physical activity, reducing the supply of calories in order to get rid of overweight or obesity. Help in quitting tobacco addiction should take place through the minimal nicotine intervention and, if necessary, pharmacological therapy. Another thing is the control of other risk factors, i. e. the appropriate treatment of dyslipidemia (the primary target is LDL cholesterol <1.8 mmol/l or reduction by ≥ 50%, if the initial concentration is between 1.8 and 3.5 mmol/l, treatment hypertension (target arterial pressure for most people aged 18-65 is in the range: 120-130/70-79 mmHg, if it is well tolerated, while for older people it is in the range: 130-139/70-79mmHg, if it is well tolerated), optimal diabetes therapy (target glycated hemoglobin <7%) and appropriate antiplatelet therapy (in most patients double antiplatelet therapy is recommended for 12 months after acute coronary syndrome). These activities lead to a significant improvement in quality of life and a decrease in mortality due to cardiovascular diseases.


Assuntos
Doenças Cardiovasculares , Infarto do Miocárdio , Idoso , Animais , Criança , Europa (Continente) , Humanos , Qualidade de Vida , Fatores de Risco
15.
Faraday Discuss ; 212(0): 467-497, 2018 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-30302450

RESUMO

Path-Integral Monte Carlo methods were applied to calculate the second, B(T), and the third, C(T), virial coefficients for water. A fully quantum approach and state-of-the-art flexible-monomer pair and three-body potentials were used. Flexible-monomer potentials allow calculations for any isotopologue; we performed calculations for both H2O and D2O. For B(T) of H2O, the quantum effect contributes 25% of the value at 300 K and is not entirely negligible even at 1000 K, in accordance with recent literature findings. The effect of monomer flexibility, while not as large as some claims in the literature, is significant compared to the experimental uncertainty. It is of opposite sign to the quantum effect, smaller in magnitude than the latter below 500 K, and varies from 2% at 300 K to 10% at 700 K. When monomer flexibility is accounted for, results from the CCpol-8sf pair potential are in excellent agreement with the available experimental data and provide reliable B(T) values at temperatures outside the range of experimental data. The flexible-monomer MB-pol pair potential yields B(T) values that are slightly too high compared to experiment. For C(T), our calculations confirm earlier findings that the use of three-body potential is necessary for meaningful predictions. However, due to various uncertainties of the potentials used, especially the three-body ones, we were not able to establish benchmark values of C(T), although our results are in qualitative agreement with available experimental data. The quantum effect, never before included for water, reduces the magnitude of the classical value for H2O by a factor of 2.5 at 300 K and is not entirely negligible even at 1000 K.

16.
J Org Chem ; 82(15): 8234-8241, 2017 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-28670903

RESUMO

Ten bis(boranils) differently substituted at the boron atom and iminophenyl groups were synthesized from 1,5-dihydroxynaphthalene-2,6-dicarboxaldehyde using a simple one-pot protocol. Their photophysical properties can be easily tuned in a wide range by the variation of substituents. Their absorption and emission spectral bands are significantly red-shifted (λmax = 495-590 nm, λem = 533-683 nm) when compared with simple boranils, whereas fluorescence quantum yields are strongly improved to reach 83%. The attachment of pendant NO2 and NEt2 groups at the opposite positions of the π-conjugated bis(boranil) scaffold resulted in the formation of an unprecedented system featuring push-pull architecture.

17.
J Chem Phys ; 146(5): 054304, 2017 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-28178790

RESUMO

We use a new high-accuracy all-dimensional potential to compute the cross second virial coefficient B12(T) between molecular hydrogen and carbon monoxide. The path-integral method is used to fully account for quantum effects. Values are calculated from 10 K to 2000 K and the uncertainty of the potential is propagated into uncertainties of B12. Our calculated B12(T) are in excellent agreement with most of the limited experimental data available, but cover a much wider range of temperatures and have lower uncertainties. Similar to recently reported findings from scattering calculations, we find that the reduced-dimensionality potential obtained by averaging over the rovibrational motion of the monomers gives results that are a good approximation to those obtained when flexibility is fully taken into account. Also, the four-dimensional approximation with monomers taken at their vibrationally averaged bond lengths works well. This finding is important, since full-dimensional potentials are difficult to develop even for triatomic monomers and are not currently possible to obtain for larger molecules. Likewise, most types of accurate quantum mechanical calculations, e.g., spectral or scattering, are severely limited in the number of dimensions that can be handled.

18.
Przegl Lek ; 73(11): 821-3, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-29693355

RESUMO

Introduction: Cancer appears to be a major noncardiovascular factor affecting morbidity and mortality of heart failure (HF) patients. Risk of developing cancer seems to increase over time. It is well documented that patients with cancer treated with chemiotherapy are at risk of developing HF and therefore they should be screened for HF on regular basis. There is limited data whether the opposite should be done, namely routinely screen each HF patient for cancer. Purpose: We hypothesized that in HF patients cancer might be responsible for some symptoms that are incorrectly diagnose as HF related. Material and Methods: The data from "Renal Denervation in Patients With Chronic Heart Failure and Resynchronization Therapy" study of 18 patients (22% women) aged 73.2 (±9.1 years) with HF in NYHA Class II-IV and resynchronization pacemaker implanted according to current ESC guideliness at least 6 months earlier were analyzed. Patients had symptoms of heart failure despite optimal HF therapy including pharmacotherapy and CRT. Medical history including current symptoms of HF was taken, patients' demographics and vital signs were assessed. Diagnostic tests in the study group included echocardiography, abdominal CT scan and laboratory tests. Results: Only in 5 patients CT scan did not show any abnormalities. Renal cysts were present in 5 patients, adrenal glands adenomas were observed in 3 patients and both changes were present in 1 patient. Tumors suspected of malignancy were diagnosed in 4 patients - 2 had a tumor in adrenal glands, 1 had kidney tumor and 1 had tumors both in kidney and adrenal gland. All patients with malignancy were directed for further oncological evaluation. Conclusion: Considering the complex physiology of HF, there is possibility that some HF related mechanisms might trigger cancer development and presence of cancer may aggrevate the symptoms of HF. One should consider evaluation of HF patients on optimal medical therapy, yet still symptomatic to identify some common forms of cancer.


Assuntos
Neoplasias Abdominais/diagnóstico por imagem , Terapia de Ressincronização Cardíaca , Insuficiência Cardíaca/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Neoplasias Abdominais/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/terapia , Humanos , Masculino , Pessoa de Meia-Idade
19.
J Phys Chem A ; 119(12): 2940-64, 2015 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-25687650

RESUMO

A potential energy surface for the water dimer with explicit dependence on monomer coordinates is presented. The surface was fitted to a set of previously published interaction energies computed on a grid of over a quarter million points in the 12-dimensional configurational space using symmetry-adapted perturbation theory and coupled-cluster methods. The present fit removes small errors in published fits, and its accuracy is critically evaluated. The minimum and saddle-point structures of the potential surface were found to be very close to predictions from direct ab initio optimizations. The computed second virial coefficients agreed well with experimental values. At low temperatures, the effects of monomer flexibility in the virial coefficients were found to be much smaller than the quantum effects.

20.
J Chem Phys ; 141(4): 044119, 2014 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-25084893

RESUMO

We present a path-integral Monte Carlo procedure for the fully quantum calculation of the second molecular virial coefficient accounting for intramolecular flexibility. This method is applied to molecular hydrogen (H2) and deuterium (D2) in the temperature range 15-2000 K, showing that the effect of molecular flexibility is not negligible. Our results are in good agreement with experimental data, as well as with virials given by recent empirical equations of state, although some discrepancies are observed for H2 between 100 and 200 K.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA