Resonant transparency of materials with negative permittivity

It is shown that the transparency of opaque material with negative permittivity exhibits resonant behavior. The resonance occurs as a result of the excitation of the surface waves at slab boundaries. Dramatic field amplification of the incident evanescent fields at the resonance improves the resolution of the the sub-wavelength imaging system (superlens). A finite thickness slab can be totally transparent to a \textit{p}-polarized obliquely incident electromagnetic wave for certain values of the incidence angle and wave frequency corresponding to the excitation of the surface modes. At the resonance, two evanescent waves have a finite phase shift providing non-zero energy flux through the non-transparent region

Surface Oscillations in Overdense Plasmas Irradiated by Ultrashort Laser Pulses

The generation of electron surface oscillations in overdense plasmas irradiated at normal incidence by an intense laser pulse is investigated. Two-dimensional (2D) particle-in-cell simulations show a transition from a planar, electrostatic oscillation at $2\omega$, with $\omega$ the laser frequency, to a 2D electromagnetic oscillation at frequency $\omega$ and wavevector $k>\omega/c$. A new electron parametric instability, involving the decay of a 1D electrostatic oscillation into two surface waves, is introduced to explain the basic features of the 2D oscillations. This effect leads to the rippling of the plasma surface within a few laser cycles, and is likely to have a strong impact on laser interaction with solid targets.Comment: 9 pages (LaTeX, Revtex4), 4 GIF color figures, accepted for publication in Phys. Rev. Let

Interface electronic states and boundary conditions for envelope functions

The envelope-function method with generalized boundary conditions is applied to the description of localized and resonant interface states. A complete set of phenomenological conditions which restrict the form of connection rules for envelope functions is derived using the Hermiticity and symmetry requirements. Empirical coefficients in the connection rules play role of material parameters which characterize an internal structure of every particular heterointerface. As an illustration we present the derivation of the most general connection rules for the one-band effective mass and 4-band Kane models. The conditions for the existence of Tamm-like localized interface states are established. It is shown that a nontrivial form of the connection rules can also result in the formation of resonant states. The most transparent manifestation of such states is the resonant tunneling through a single-barrier heterostructure.Comment: RevTeX4, 11 pages, 5 eps figures, submitted to Phys.Rev.

Sex-Related Differences in Characteristics and Therapy of Heart Failure Patients

Aim: To determine the differences in comorbidities, therapy and echocardiographic measures among patients hospitalized for heart failure relative to gender. Methods: The study included patients hospitalized for heart failure at the Department of Cardiovascular Diseases of the Clinical Hospital Center Osijek in the period from 1 January 2020 to 30 March 2021. Results: There were 200 patients included in the study, of which 100 (50%) were male and 100 (50%) were female. Female patients were older, while male patients more frequently had a history of coronary artery disease. Men had a higher dose of loop diuretic on admission to the hospital. No significant difference was found in the representation of beta blockers and ACE inhibitors in therapy with regard to gender. On the other hand, men more frequently used MRA, sacubitril/valsartan and antiplatelet medication at hospital admission. Male patients had a larger left ventricular end-diastolic diameter, left ventricular end-systolic diameter and a lower left ventricular ejection fraction (EF). Regarding the type of heart failure according to EF, 72% of men had HFrEF, 20% HFmrEF and 8% HFpEF. In women, 47% had HFrEF, 33% HFmrEF and 20% HFpEF. During hospitalization due to heart failure, 22 patients died, an equal number of men and women. Conclusion: This research confirmed the differences in risk factors and pathophysiology of heart failure between males and females. Medicine is progressing towards an individual approach to each patient, so further research will be needed to find the best therapy for both male and female patients

Theory of extraordinary optical transmission through subwavelength hole arrays

We present a fully three-dimensional theoretical study of the extraordinary transmission of light through subwavelength hole arrays in optically thick metal films. Good agreement is obtained with experimental data. An analytical minimal model is also developed, which conclusively shows that the enhancement of transmission is due to tunneling through surface plasmons formed on each metal-dielectric interfaces. Different regimes of tunneling (resonant through a ''surface plasmon molecule", or sequential through two isolated surface plasmons) are found depending on the geometrical parameters defining the system.Comment: 4 pages, 4 figure

Precipitirajući čimbenici i simptomi u bolesnika s dijabetičkom ketoacidozom

The aim of the study was to determine the most common precipitating factors and symptoms of diabetic ketoacidosis and the possible difference according to age, gender and severity of diabetic ketoacidosis. Medical records from January 1, 2017 until December 31, 2019 were reviewed and patients diagnosed with diabetic ketoacidosis were selected. The study included 52 patients, median age 34 (interquartile range 21-56) years. There was no statistically significant difference between male and female gender. The severity of diabetic ketoacidosis was moderate in the majority of cases (65.4%; p=0.005). The most common precipitating factor was infection (61.7%). In patients with moderate diabetic ketoacidosis, respiratory infections were more common, while gastrointestinal infections were more common in severe diabetic ketoacidosis (33% and 25%, respectively; p=0.03). Nausea (median age 32 years; p=0.004) and vomiting (median age 31 years; p=0.01) were more common in younger age groups, while altered mental status was more common in the older age group (median age 61 years; p=0.001). Infection was the most common precipitating factor. The most common symptoms in younger age groups were nausea and vomiting, and altered mental status in the older age group.Cilj istraživanja je bio utvrditi najčešće precipitirajuće čimbenike i simptome dijabetičke ketoacidoze te postoji li razlika s obzirom na dob, spol i stupanj dijabetičke ketoacidoze. Pregledana je medicinska dokumentacija od 1. siječnja 2017. do 31. prosinca 2019. godine te su izdvojeni bolesnici s dijagnozom dijabetičke ketoacidoze. U istraživanje je uključeno 52 bolesnika. Medijan dobi bio je 34 godine (interkvartilni raspon 21-56 godina). Nije postojala statistički značajna razlika muškog i ženskog spola. U najvećem broju slučajeva radilo se o umjerenom stupnju dijabetičke ketoacidoze (65,4%; p=0,005). Najčešći precipitirajući čimbenik bila je infekcija (61,7%). Kod umjerenog stupnja najčešće se radilo o respiracijskim infekcijama, a u teškom stupnju o gastrointestinalnim infekcijama (33% i 25%; p=0,03). U mlađim dobnim skupinama češće su se pojavljivale mučnina (medijan dobi 32 godine; p=0,004) i povraćanje (medijan dobi 31 godina; p=0,01), a u starijoj dobnoj skupini poremećaj svijesti (medijan dobi 61 godina; p=0,001). Infekcije su bile najčešći precipitirajući čimbenik dijabetičke ketoacidoze. Najčešći simptomi u mlađim dobnim skupinama bili su mučnina i povraćanje, a u starijoj dobnoj skupini poremećaj svijesti

Serum glucose, sodium and potassium concentrations in patients with diabetic ketoacidosis

Aim To investigate possible differences in serum glucose and sodium and potassium concentrations with respect to age, gender and severity of diabetic ketoacidosis. Methods Medical records from 1 January 2017 to 31 December 2019 were reviewed and patients with the diagnosis of diabetic ketoacidosis were selected. Results The study included 52 patients. Glucose concentration was significantly higher in the age group of 25-44 and >65 years compared to the group of 18-24 years (p=0.02). Sodium concentration was significantly higher in the age group 18-24 and >65 years compared to groups 25-44 and 45-65 years (p=0.002). Females had significantly higher sodium concentration than males (p=0.002). Potassium concentration was significantly higher in the age group 25-44 years compared to other groups (p=0.01). Males had significantly higher potassium concentration (p =0.01). Conclusion This study showed that significant differences exist in electrolyte concentration between specific age groups, male and female gender as well as DKA severity. Knowing these differences could help clinicians to promptly recognize and treat electrolyte derangements, leading to better outcome of patients with DKA

Prevalence of familial hypercholesterolemia in patients with acute coronary syndrome

Aim To investigate the prevalence of familial hypercholesterolemia in patients with acute coronary syndrome (ACS). Methods The study included fifteen patients with first or repeated ACS and treated/nontreated dyslipidaemia admitted to the Department of Cardiovascular Diseases of Clinical Hospital Centre Osijek between 1 January 2020 and 1 January 2021. The cut-off value of low-density lipoprotein (LDL)-C was 4.5mmol/L as a possible cut-off value for familial hypercholesterolemia presence. Data were collected from medical history and during patient’s follow-up. Results Included patients that fulfilled criteria were predominantly male – 14 (93%), mean age 61 years. The median level of LDL cholesterol at admission because of ACS was 5.14 mmol/L, whereas the follow-up level after one year was 2.27 mmol/L (p=0.001). At first follow-up, 7 (46%) patients were treated with atorvastatin 80 mg or rosuvastatin 40 mg, 3 (20%) atorvastatin 80mg + ezetimibe 10mg, 2 (13%) with rosuvastatin 40 mg+ ezetimibe 10 mg, other patients were treated with a lower dose of statin or ezetimibe. According to LDL-C profile and by calculating the Dutch Lipid Clinic Network Score, one (of 15) patient was categorized as having definite familial hypercholesterolemia and two (of 15) as having probable familial hypercholesterolemia leading to the use of triple hypolipidemic therapy (statin+ezetimibe+PCSK9 inhibitor) in 2 (13%) patients (one female and one male). Conclusion LDL-C level ​​of 4.5 mmol/L and higher represents an indication for screening for familial hypercholesterolemia in patients with ACS. The prevalence of familial hypercholesterolemia in ACS, estimated by the Dutch Lipid Clinic Network Score, could be higher than previously reported