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1.
Mater Today Bio ; 11: 100120, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34337378

RESUMO

Biominerals formed by organisms in the course of biomineralization often demonstrate complex morphologies despite their single-crystalline nature. This is achieved owing to the crystallization via a predeposited amorphous calcium carbonate (ACC) phase, a precursor that is particularly widespread in biominerals. Inspired by this natural strategy, we used robocasting, an additive manufacturing three-dimensional (3D) printing technique, for printing 3D objects from novel long-term, Mg-stabilized ACC pastes with high solids loading. We demonstrated, for the first time, that the ACC remains stable for at least a couple of months, even after printing. Crystallization, if desired, occurs only after the 3D object is already formed and at temperatures significantly lower than those of common postprinting sintering. We also examined the effects different organic binders have on the crystallization, the morphology, and the final amount of incorporated Mg. This novel bio-inspired method may pave the way for a new bio-inspired route to low-temperature 3D printing of ceramic materials for a multitude of applications.

2.
RSC Adv ; 10(57): 34333-34343, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-35514427

RESUMO

A process of atomic layer deposition (ALD) combined with self-assembled monolayers (SAMs) was used to investigate the possible modification of the wetting properties of polyurethane (PUR) paint surfaces without altering their original hue. First, we used an ALD process to produce thin and uniform Al2O3 coatings of these surfaces at temperatures as low as 80 °C. We then successfully achieved the addition of 16-phosphono-hexadecanoic acid (16-PHA) SAMs to the Al2O3-coated paint samples. Given initial hydrophobicity, which however was not stable over time, Al2O3 coatings reduced the contact angle of the PUR surfaces from 110 to 10°. Addition of SAMs on the Al2O3 coatings induced a sustained reduction in their contact angles to 60-70°, and aging of the samples revealed a further decrease to 25-40°. Testing of the Al2O3/16-PHA coating in a Weather-Ometer (WOM) revealed its durability even under harsh outdoor conditions. These experimental results show that by combining ALD with SAMs it is possible to produce durable coatings with modified hydrophilic/hydrophobic properties that are stable over time. The use of SAMs with different end-groups may allow fine-tuning of the coating's wetting properties.

3.
Br J Dermatol ; 173(2): 464-70, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25760289

RESUMO

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic relapsing inflammatory skin disease. OBJECTIVES: To evaluate the association between HS and metabolic syndrome and its component morbidities in a large, community-based cohort of patients with HS, using the database of Clalit Health Services, the largest public healthcare provider in Israel. METHODS: A cross-sectional study was performed. Metabolic syndrome was defined as the presence of at least three of the following conditions: diabetes, hyperlipidaemia, hypertension and obesity. The association between HS and metabolic syndrome was assessed by a multivariate logistic regression model, adjusting for age, sex, diabetes, hypertension, hyperlipidaemia, obesity and smoking status. RESULTS: The study included 3207 patients with HS (general frequency of 0·07%) diagnosed by a dermatologist in primary-care centres, and 6412 age- and sex-matched control patients without HS. HS was significantly associated with metabolic syndrome [odds ratio (OR) 1·61, 95% confidence interval (CI) 1·36-1·89], diabetes (OR 1·41, 95% CI 1·19-1·66), obesity (OR 1·71, 95% CI 1·53-1·91), hyperlipidaemia (OR 1·14, 95% CI 1·02-1·28) and hypertension (OR 1·19, 95% CI 1·03-1·38). CONCLUSIONS: We found an association between HS and diabetes, hyperlipidaemia, obesity, hypertension and metabolic syndrome among a large community-based cohort of patients with HS. Clinicians should take into account that patients with HS may have one or more undiagnosed components of metabolic syndrome despite their young age. Thus, appropriate targeted screening is advised.


Assuntos
Hidradenite Supurativa/complicações , Síndrome Metabólica/complicações , Adulto , Estudos Transversais , Complicações do Diabetes/complicações , Complicações do Diabetes/epidemiologia , Feminino , Hidradenite Supurativa/epidemiologia , Humanos , Hiperlipidemias/complicações , Hiperlipidemias/epidemiologia , Hipertensão/complicações , Hipertensão/epidemiologia , Israel/epidemiologia , Masculino , Síndrome Metabólica/epidemiologia , Obesidade/complicações , Obesidade/epidemiologia
4.
Phys Rev E Stat Nonlin Soft Matter Phys ; 81(2 Pt 2): 026601, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20365666

RESUMO

The interference is considered of guided polariton modes in a two-port ring waveguide composed of dielectric nanospheres. The dependence of the guided polariton intensity on the relative orientation of the input and output channels is investigated. It is shown that, if the frequency of the external light source corresponds to one of the resonant modes of the waveguide ring segment, the guided polariton may be treated as two optical beams running along the ring segment in the opposite directions and interfering with each other. The multisphere Mie scattering formalism is used. The dipole approximation is shown to grasp the essence of physics. Our simple interpretation of the results is obtained in terms of scalar waves. The applications of the interference revealed in the manuscript are discussed as well.

5.
Opt Express ; 15(25): 17380-91, 2007 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-19551032

RESUMO

We have investigated low frequency guiding polariton modes in finite linear chains of closely packed dielectric spherical particles of different optical materials. These guiding (chain bound) modes cannot decay radiatively, because photon emission cannot take place with simultaneous conservation of energy and momentum. For extending previous work on infinite chains of spherical particles [1] and infinite rods [2, 3], we were able to apply the multisphere Mie scattering formalism to finite chains of dielectric particles to calculate quality factors of most bound modes originating from the first two Mie resonances depending on the number of particles N and the material's refractive index nr. We found that, in agreement with the earlier work [4], guiding modes exist for n(r) > 2 and the quality factor of the most bound mode scales by N(3). We interpreted this behavior as the property of "frozen" modes near the edges of guiding bands with group velocity vanishing as N increases. In contrast with circular arrays, longitudinal guiding modes in particle chains possess a higher quality factor compared to the transverse ones.

6.
J Hum Hypertens ; 20(7): 504-9, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16625240

RESUMO

To assess vascular compliance in patients with antiphospholipid syndrome (APS), or antiphospholipid antibodies (aPLs) positivity in comparison to healthy people and diabetes mellitus patients. Twenty-five patients with APS or aPLs, 33 healthy people (HP), 28 patients with diabetes mellitus (DM) underwent pulse wave analysis. Data calculated included the small artery elasticity (SAE), large artery elasticity (LAE) and systemic vascular resistance (SVR). Statistical analysis was performed as appropriate. The patient group was divided into two subgroups: APS-1 with warfarin treatment, and APS-2 without warfarin treatment. All patients and healthy subjects were matched by gender, body mass index and lipid profiles. Patients in APS-1 group were significantly younger in comparison to three other groups. After the adjustment for age, we found that SAE in APS-1 group did not differ from SAE in the HP group (6.4+/-1.8 ml/mmHg x 100 and 5.54+/-3.4 ml/mmHg x 100, respectively, P>0.05). In contrast, SAE in the group APS-2 was significantly lower (3.41+/-1.2 ml/mmHg x 100) than in the APS-1 and was almost equal to SAE in the DM group (4.2+/-2.37 ml/mmHg x 100). The SAE in the APS-2, DM and HP groups was inversely correlated with age, whereas in the APS-1 group we did not find such correlation. This pilot study showed abnormal small vascular elasticity in the patients with positive aPL, relative to the healthy subjects. The APS patients, treated with warfarin had the normal vascular function. This data support the hypothesis that APS may be associated with diffuse changes in the arterial wall, and may be a risk factor for atherosclerotic disease.


Assuntos
Síndrome Antifosfolipídica/patologia , Artérias/patologia , Diabetes Mellitus/patologia , Adulto , Fatores Etários , Análise de Variância , Anticorpos Antifosfolipídeos/sangue , Síndrome Antifosfolipídica/imunologia , Síndrome Antifosfolipídica/fisiopatologia , Artérias/imunologia , Artérias/fisiopatologia , Índice de Massa Corporal , Estudos de Casos e Controles , Complacência (Medida de Distensibilidade) , Diabetes Mellitus/sangue , Diabetes Mellitus/fisiopatologia , Feminino , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade
7.
Phys Rev Lett ; 96(2): 025505, 2006 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-16486595

RESUMO

The standard tunneling model describes quite satisfactorily the properties of amorphous solids at temperatures T < 1K in terms of an ensemble of two-level systems including the logarithmic temperature dependence of the dielectric constant. Yet, experiments have shown that at ultralow temperatures T< 5 mK such a temperature behavior breaks down and the dielectric constant becomes temperature independent (plateau effect). In this Letter we suggest an explanation of this behavior exploiting the effect of the nuclear quadrupole interaction on tunneling. We also predict that the application of a sufficiently large magnetic field B> 10T should restore the logarithmic dependence because of the suppression of the nuclear quadrupole interaction.

8.
Lupus ; 12(1): 67-9, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12587830

RESUMO

We report a case of a patient with clinical features of progressive supranuclear palsy and raised titres of anticardiolipin antibodies in blood, thrombocytopenia and livedo reticularis on skin. Magnetic resonance imaging of brain and isotope scan of brain were distinctive of vascular disorder.


Assuntos
Síndrome Antifosfolipídica/diagnóstico , Paralisia Supranuclear Progressiva/diagnóstico , Anticorpos Anticardiolipina/sangue , Síndrome Antifosfolipídica/imunologia , Diagnóstico Diferencial , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
9.
Phys Rev Lett ; 86(24): 5616-9, 2001 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-11415315

RESUMO

The delocalization of excitations in an ensemble of two-level systems with a strong disorder due to an external alternating acoustic or electric field is considered. The propagating modes are shown to appear if a ratio of the field amplitude to the frequency is large enough. Two complementary approaches, the static one similar to that of Anderson and the dynamic one related to Landau-Zener, are developed. It is shown that the field-induced relaxation mechanism can have a strong influence on the kinetics. The internal friction is argued to be vastly affected by the relaxation mechanism proposed.

10.
Artigo em Russo | MEDLINE | ID: mdl-9082723

RESUMO

Data on some parameters of the epidemic process of campylobacteriosis in the Ukraine are presented. Campylobacteriosis patients were found to constitute 1.9 +/- 0.095% of all examined patients with acute enteric infections (AEI). No statistically significant difference in the proportion of campylobacteriosis among child and adult AEI patients was established. The proportion of sick persons at the period of the spring-summer rise in morbidity was 71.5%. A definite relationship between the epizootic and epidemic processes in campylobacteriosis was noted. In the Ukraine the predominant infective agent was Campylobacter jejuni belonging mainly to serotype Lio and biotype 1. Quite frequently campylobacteriosis was found to be accompanied by mixed infections.


Assuntos
Infecções por Campylobacter/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Adulto , Animais , Técnicas de Tipagem Bacteriana , Campylobacter/classificação , Campylobacter/isolamento & purificação , Infecções por Campylobacter/microbiologia , Galinhas/microbiologia , Criança , Pré-Escolar , Humanos , Lactente , Carne/microbiologia , Estações do Ano , Sorotipagem , Ucrânia/epidemiologia , População Urbana/estatística & dados numéricos
13.
Lik Sprava ; (11-12): 118-9, 1992.
Artigo em Russo | MEDLINE | ID: mdl-1292206

RESUMO

Analyzed were results of a clinical use of a new drug carbabanzpyrid in 57 patients as an analgetic, antipyretic, anti-inflammatory, interferonogenic drug. The drug proved effective in the complex treatment of several diseases, accompanied by fever, pain syndromes of different genesis and location, acute respiratory viral infections, active inflammatory processes of different etiology including bronchitis, pneumonia, active rheumatism, arthralgias, myalgias. The drug was of little efficacy in infections-allergic polyarthritis with a marked exudative component.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Compostos Heterocíclicos , Anti-Inflamatórios não Esteroides/efeitos adversos , Feminino , Febre/tratamento farmacológico , Humanos , Masculino , Dor/tratamento farmacológico , Compostos de Piridínio
14.
Vrach Delo ; (11): 35-8, 1990 Nov.
Artigo em Russo | MEDLINE | ID: mdl-1983050

RESUMO

The authors studied 67 patients with ischemic heart disease associated with hypertensive disease and revealed that the use of beta-adrenoblockaders and calcium antagonists resulted in a reduction of the manifestations of the disease, increase of physical load tolerance, optimization of its hemodynamic and oxygen provision. In patients under 60 years of age of beta-adrenoblockaders resulted in an increase of the myocardial contractility. This was not observed in those over 60 years of age. It is concluded that in patients combining IHD with hypertensive disease under 60 it is more preferable to use beta-adrenoblockers, in those over 60--calcium antagonists.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Doença das Coronárias/tratamento farmacológico , Hipertensão/tratamento farmacológico , Adulto , Idoso , Envelhecimento/efeitos dos fármacos , Envelhecimento/fisiologia , Doença das Coronárias/fisiopatologia , Avaliação de Medicamentos , Teste de Esforço , Humanos , Hipertensão/fisiopatologia , Pessoa de Meia-Idade , Propranolol/uso terapêutico , Verapamil/uso terapêutico
16.
Vrach Delo ; (6): 51-2, 1989 Jun.
Artigo em Russo | MEDLINE | ID: mdl-2781761

RESUMO

The authors describe two cases of during life diagnosis of thromboembolism of pulmonary artery branches confirmed at autopsy. Certain criteria or such diagnosis are discussed, namely: latent cor pulmonale, reduction of ECG voltage, ECG signs of interventricular septum infarction, hemorrhagic syndrome as a manifestation of intravascular coagulation.


Assuntos
Embolia Pulmonar/diagnóstico , Doença Aguda , Idoso , Feminino , Humanos , Masculino , Artéria Pulmonar/patologia , Embolia Pulmonar/patologia
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