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BACKGROUND: Hyperglycemia has detrimental effect on ischemic myocardium, but the impact of acute hyperglycemia on the myocardium in asymptomatic diabetic patients has not been fully elucidated. Thus, this follow-up study was aimed to investigate the effects and reversibility of acute hyperglycemia on regional contractile function of left ventricle (LV) in diabetic patients without cardiovascular disease. METHODS: The two-dimensional speckle tracking echocardiography (2D-STE), including multilayer strain analysis, was used for evaluation of global and regional LV function in asymptomatic, normotensive patients with uncomplicated diabetes, with acute hyperglycemia ( ≥ 11.1 mmol/l) (Group A, n = 67), or with optimal metabolic control (fasting plasma glucose < 7 mmol/l and HbA1c < 7%) (Group B, n = 20), while 20 healthy individuals served as controls (Group C). In group A, after 72 h of i.v. continuous insulin treatment (at the time euglycemia was achieved) (second examination) and after 3 months following acute hyperglycemia (third examination) 2D-STE was repeated. RESULTS: Global longitudinal strain (GLS) (- 19.6 ± 0.4%) in Group A was significantly lower in comparison to both groups B (- 21.3 ± 0.4%; p < 0.05) and C (- 21.9 ± 0.4%; p < 0.01) at baseline, while we could not detect the differences between groups B and C. Peak systolic longitudinal endocardial (Endo), mid-myocardial (Mid) and epicardial (Epi) layer strain were significantly lower in group A at baseline compared to both groups B and C. Deterioration in peak systolic circumferential strain was observed at basal LV level, in all three layers (Endo, Mid and Epi) and in mid-cavity LV level in Epi layer in group A in comparison to group C. Moreover, in group A, after euglycemia was achieved (at second and third examination) GLS, as well as peak longitudinal and circumferential strain remain the same. CONCLUSION: Acute hyperglycemia in asymptomatic diabetic patients has significant negative effects on systolic LV myocardial mechanics primarily by reducing GLS and multilayer peak systolic longitudinal and circumferential strain which was not reversible after three months of good glycemic control.
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Glicemia/metabolismo , Diabetes Mellitus/sangue , Cardiomiopatias Diabéticas/diagnóstico por imagem , Ecocardiografia Doppler , Contração Miocárdica , Disfunção Ventricular Esquerda/diagnóstico por imagem , Função Ventricular Esquerda , Adulto , Doenças Assintomáticas , Biomarcadores/sangue , Glicemia/efeitos dos fármacos , Estudos de Casos e Controles , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/tratamento farmacológico , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/fisiopatologia , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de Tempo , Resultado do Tratamento , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/fisiopatologiaRESUMO
The dynamics of charge-ordered states is one of the key issues in underdoped cuprate high-temperature superconductors, but static short-range charge-order (CO) domains have been detected in almost all cuprates. We probe the dynamics across the CO (and structural) transition in La_{1.48}Nd_{0.4}Sr_{0.12}CuO_{4} by measuring nonequilibrium charge transport, or resistance R as the system responds to a change in temperature and to an applied magnetic field. We find evidence for metastable states, collective behavior, and criticality. The collective dynamics in the critical regime indicates strong pinning by disorder. Surprisingly, nonequilibrium effects, such as avalanches in R, are revealed only when the critical region is approached from the charge-ordered phase. Our results on La_{1.48}Nd_{0.4}Sr_{0.12}CuO_{4} provide the long-sought evidence for the fluctuating order across the CO transition, and also set important constraints on theories of dynamic stripes.
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A study of the temperature (T) and density (ns) dependence of conductivity σ(ns,T) of a highly disordered, two-dimensional (2D) electron system in Si demonstrates scaling behavior consistent with the existence of a metal-insulator transition (MIT). The same critical exponents are found when the Coulomb interaction is screened by the metallic gate and when it is unscreened or long range. The results strongly suggest the existence of a disorder-dominated 2D MIT, which is not directly affected by the range of the Coulomb interactions.
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A central issue for copper oxides is the nature of the insulating ground state at low carrier densities and the emergence of high-temperature superconductivity from that state with doping. Even though this superconductor-insulator transition (SIT) is a zero-temperature transition, measurements are not usually carried out at low temperatures. Here we use magnetoresistance to probe both the insulating state at very low temperatures and the presence of superconducting fluctuations in La(2-x)Sr(x)CuO(4) films, for doping levels that range from the insulator to the superconductor (x = 0.03-0.08). We observe that the charge glass behaviour, characteristic of the insulating state, is suppressed with doping, but it coexists with superconducting fluctuations that emerge already on the insulating side of the SIT. The unexpected quenching of the superconducting fluctuations by the competing charge order at low temperatures provides a new perspective on the mechanism for the SIT.
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The absence of thermalization in certain isolated many-body systems is of great fundamental interest. Many-body localization (MBL) is a widely studied mechanism for thermalization to fail in strongly disordered quantum systems, but it is still not understood precisely how the range of interactions affects the dynamical behavior and the existence of MBL, especially in dimensions D > 1. By investigating nonequilibrium dynamics in strongly disordered D = 2 electron systems with power-law interactions â 1/rα and poor coupling to a thermal bath, here we observe MBL-like, prethermal dynamics for α = 3. In contrast, for α = 1, the system thermalizes, although the dynamics is glassy. Our results provide important insights for theory, especially since we obtained them on systems that are much closer to the thermodynamic limit than synthetic quantum systems employed in previous studies of MBL. Thus, our work is a key step towards further studies of ergodicity breaking and quantum entanglement in real materials.
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Primary cutaneous apocrine carcinoma (PCAC), a subtype of sweat gland carcinoma, is an extremely rare malignant neoplasm. Distinguishing an apocrine carcinoma from a breast carcinoma metastasis is difficult even for a pathologist. Most arise in regions of high apocrine gland density like the axilla, and rarely on the scalp and eyelid, but they can occur elsewhere on the skin. Primary cutaneous apocrine carcinoma of the scalp is a rare malignancy most often reported in the literature as case reports or small case series. The giant form of primary cutaneous apocrine carcinoma in the frontal region has not been described in the literature, to the best of our knowledge. There are no established protocols for treatment of primary cutaneous apocrine carcinoma. We report a case of a giant primary cutaneous apocrine carcinoma localized in the frontal region. A definitive diagnosis of a primary cutaneous apocrine carcinoma was established by biopsy with microscopic and immunohistochemical analysis. Wide surgical excision and reconstruction with large local transposition flap and split thickness skin grafts for secondary defect were our therapy of choice. Primary cutaneous apocrine carcinoma is a very rare malignancy, and the giant form has not yet been described. Surgical treatment provided the patient with tumor-free status as well as satisfactory aesthetical appearance and quality of life.
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Neoplasias da Mama , Carcinoma , Neoplasias das Glândulas Sudoríparas , Humanos , Feminino , Qualidade de Vida , Neoplasias das Glândulas Sudoríparas/diagnóstico , Neoplasias das Glândulas Sudoríparas/cirurgia , Neoplasias das Glândulas Sudoríparas/patologia , Melanoma Maligno CutâneoRESUMO
Magnetization and magnetoresistance have been measured in insulating antiferromagnetic La2Cu0.97Li0.03O4 over a wide range of temperatures, magnetic fields, and field orientations. The magnetoresistance step associated with a weak ferromagnetic transition exhibits a striking nonmonotonic temperature dependence, consistent with the presence of Skyrmions.
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The origin of the weak insulating behavior of the resistivity, i.e. [Formula: see text], revealed when magnetic fields (H) suppress superconductivity in underdoped cuprates has been a longtime mystery. Surprisingly, the high-field behavior of the resistivity observed recently in charge- and spin-stripe-ordered La-214 cuprates suggests a metallic, as opposed to insulating, high-field normal state. Here we report the vanishing of the Hall coefficient in this field-revealed normal state for all [Formula: see text], where [Formula: see text] is the zero-field superconducting transition temperature. Our measurements demonstrate that this is a robust fundamental property of the normal state of cuprates with intertwined orders, exhibited in the previously unexplored regime of T and H. The behavior of the high-field Hall coefficient is fundamentally different from that in other cuprates such as YBa2Cu3O6+x and YBa2Cu4O8, and may imply an approximate particle-hole symmetry that is unique to stripe-ordered cuprates. Our results highlight the important role of the competing orders in determining the normal state of cuprates.
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The less productive soils present one of the major problems in wheat production. Because of unfavorable conditions, halomorphic soils could be intensively utilized using ameliorative measures and by selecting suitable stress tolerant wheat genotypes. This study examined the responses of ten winter wheat cultivars on stressful conditions of halomorphic soil, solonetz type in Banat, Serbia. The wheat genotypes were grown in field trails of control and treatments with two soil amelioration levels using phosphor gypsum, in amounts of 25 and 50 tha-1. Across two vegetation seasons, phenotypic variability and genotype by environment interaction (GEI) for yield traits of wheat were studied. The additive main effects and multiplicative interaction (AMMI) models were used to study the GEI. AMMI analyses revealed significant genotype and environmental effects, as well as GEI effect. Analysis of GEI using the IPCA (Interaction Principal Components) analysis showed a statistical significance of the first two main components, IPCA1 and IPCA2 for yield, which jointly explained 70% of GEI variation. First source of variation IPCA1 explained 41.15% of the GEI for the grain weight per plant and 78.54% for the harvest index. The results revealed that wheat genotypes responded differently to stressful conditions and ameliorative measures.
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We report the fabrication of hexagonal-boron-nitride (hBN) encapsulated multiterminal WSe2 Hall bars with 2D/2D low-temperature Ohmic contacts as a platform for investigating the two-dimensional (2D) metal-insulator transition. We demonstrate that the WSe2 devices exhibit Ohmic behavior down to 0.25 K and at low enough excitation voltages to avoid current-heating effects. Additionally, the high-quality hBN-encapsulated WSe2 devices in ideal Hall-bar geometry enable us to accurately determine the carrier density. Measurements of the temperature (T) and density (ns) dependence of the conductivity σ(T, ns) demonstrate scaling behavior consistent with a metal-insulator quantum phase transition driven by electron-electron interactions but where disorder-induced local magnetic moments are also present. Our findings pave the way for further studies of the fundamental quantum mechanical properties of 2D transition metal dichalcogenides using the same contact engineering.
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The phase diagram of underdoped cuprates in a magnetic field (H) is key to understanding the anomalous normal state of these high-temperature superconductors. However, the upper critical field (H c2), the extent of superconducting (SC) phase with vortices, and the role of charge orders at high H remain controversial. Here we study stripe-ordered La-214, i.e., cuprates in which charge orders are most pronounced and zero-field SC transition temperatures T c 0 are lowest. This enables us to explore the vortex phases in a previously inaccessible energy scale window. By combining linear and nonlinear transport techniques sensitive to vortex matter, we determine the T - H phase diagram, directly detect H c2, and reveal novel properties of the high-field ground state. Our results demonstrate that quantum fluctuations and disorder play a key role as T â 0, while the high-field ground state is likely a metal, not an insulator, due to the presence of stripes.
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In underdoped cuprates, the interplay of the pseudogap, superconductivity, and charge and spin ordering can give rise to exotic quantum states, including the pair density wave (PDW), in which the superconducting (SC) order parameter is oscillatory in space. However, the evidence for a PDW state remains inconclusive and its broader relevance to cuprate physics is an open question. To test the interlayer frustration, the crucial component of the PDW picture, we perform transport measurements on charge- and spin-stripe-ordered La1.7Eu0.2Sr0.1CuO4 and La1.48Nd0.4Sr0.12CuO4 in perpendicular magnetic fields (Hâ¥), and also with an additional field applied parallel to CuO2 layers (Hâ¥). We detect several phenomena predicted to arise from the existence of a PDW, including an enhancement of interlayer SC phase coherence with increasing Hâ¥. These data also provide much-needed transport signatures of the PDW in the regime where superconductivity is destroyed by quantum phase fluctuations.
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Different seed priming treatments are widely used in order to improve the nutritional status of wheat, as well as to improve its grain yield and yield- related traits. The present study aimed to evaluate the impact of seed priming with zinc oxide nanoparticles (ZnO NPs) on the yield related traits, such as, field emergence, plant height, spike length and grain yield per plant of four winter wheat genotypes (Triticum aestivum L.) during two vegetation seasons of 2018/2019 and 2019/2020. The seeds of each wheat genotypes were primed with different concentrations of ZnO NPs (0 mg L-1, 10 mg L-1, 100 mg L-1 and 1000 mg L-1) for 48 h in a dark box by continuous aeration and were sown in soil pots with 60-70% moisture content until full maturity. The additive main effects and multiplicative interaction (AMMI) models were used to study the genotype environment effects. The results indicated that the plants response to ZnO nanoparticles significantly increased all of the observed traits of the wheat, while its maximum rates reduced the traits of the wheat. The AMMI analysis revealed the very complex nature of the variation observed in the trial and showed the significant effect of the G×E interaction, in which the first main component was significant for all components.
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Do charge modulations compete with electron pairing in high-temperature copper oxide superconductors? We investigated this question by suppressing superconductivity in a stripe-ordered cuprate compound at low temperature with high magnetic fields. With increasing field, loss of three-dimensional superconducting order is followed by reentrant two-dimensional superconductivity and then an ultraquantum metal phase. Circumstantial evidence suggests that the latter state is bosonic and associated with the charge stripes. These results provide experimental support to the theoretical perspective that local segregation of doped holes and antiferromagnetic spin correlations underlies the electron-pairing mechanism in cuprates.
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BACKGROUND: We analyzed cardiovascular inflammatory (C-reactive protein (CRP), interleukin 6 (IL-6)), haemostatic (homocysteine) risk markers in lean and obese patients at admission and acute hyperglicemic crisis (AHC) resolving, involving diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS). METHODS: In that context, we included group A: N = 20 obese, B: N=20 lean patients with DKA; C: N = l0 obese, D: N=10 lean patients with HHS; E: N = 15 obese, F: N=15 lean controls. CRP IL-6, homocysteine were determined by ELISA. RESULTS: Our results showed that CRP IL-6, and homocysteine levels decreased in all groups: (A: p<0.001; B: p<0.001, C: p<0.05; D: p<0.001 mg/L), (A: p<0.001 B: p<0.001, C: p<0.001, D: p<0.01 pg/mL), (A: p<0.001, B: p <0.001; C: p<0.05, D: p=0.001 µmol/L), respectively, at resolving AHC. However, CRP persisted higher (p<0.001, p<0.01), IL-6 lower (p<0.05, p<0.001), while homocysteine levels turned out to be similar to controls. CONCLUSIONS: AHC is associated with increased inflammatory and hemostatic cardiovascular risk markers. Also, insulin therapy in AHC has had more pronounced favorable effect on IL-6 and homocystein than on CRP.
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BACKGROUND, AIM, AND SCOPE: The paper presents the complex approach to the assessment of the state of the environment in Southern Serbia, surroundings of Bujanovac, the region which is of great concern as being exposed to contamination by depleted uranium (DU) ammunition during the North Atlantic Treaty Organization (NATO) attacks in 1999. It includes studies on concentrations of radionuclides and heavy metals in different environmental samples 5 years after the military actions. MATERIALS AND METHODS: In October 2004, samples of soil, grass, lichen, moss, honey, and water were collected at two sites, in the immediate vicinity of the targeted area and 5 km away from it. Radionuclide ((7)Be, (40)K, (137)Cs, (210)Pb, (226)Ra, (232)Th, (235)U, (238)U) activities in solid samples were determined by standard gamma spectrometry and total alpha and beta activity in water was determined by proportional alpha-beta counting. Concentrations of 35 elements were determined in the samples of soil, moss, grass, and lichen by instrumental neutron activation analysis (INAA). RESULTS: The results are discussed in the context of a possible contamination by DU that reached the environment during the attacks as well as in the context of an environmental pollution by radionuclides and heavy metals in Southern Serbia. The results are compared to the state of environment in the region and other parts of the country both prior to and following the attacks. DISCUSSION: This is the first comprehensive study of the contents of radionuclides and heavy metals in Southern Serbia and consequently highly important for the assessment of the state of environment in this part of the country concerning possible effects of DU ammunition on the environment, as well as anthropogenic source of pollution by radionuclides and heavy metals and other elements. Also, the highly sensitive method of INAA was used for the first time to analyze the environmental samples from this area. CONCLUSIONS: The results of the study of radionuclides in the samples of soils, leaves, grass, moss, lichen, honey, and water in Southern Serbia (Bujanovac) gave no evidence of the DU contamination of the environment 5 years after the military actions in 1999. Activities of radionuclides in soils were within the range of the values obtained in the other parts of the country and within the global average. The ratio of uranium isotopes confirmed the natural origin of uranium. In general, concentrations of heavy metals in the samples of soils, plant leaves, mosses, and lichen are found to be less or in the lower range of values found in other parts of the country, in spite of the differences in plant and moss species or soil characteristics. Possible sources of heavy metal contamination were identified as a power coal plant in the vicinity of the sampling sites and wood and waste burning processes. RECOMMENDATIONS AND PERSPECTIVES: The collected data should provide a base for the health risk assessments on animals and humans in the near future. It should be emphasized that the sampling was carried out 5 years after the military action and that the number of samples was limited; therefore, the conclusions should be accepted only as observed tendencies and a detailed study should be recommended in the future.
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Poluentes Ambientais/química , Metais Pesados/química , Radioisótopos/química , Monitoramento Ambiental , Mel/análise , Plantas/química , Solo/análise , Água/química , IugosláviaRESUMO
The relaxations of conductivity have been studied in the glassy regime of a strongly disordered two-dimensional electron system in Si after a temporary change of carrier density during the waiting time tw. Two types of response have been observed: (a) monotonic, where relaxations exhibit aging, i.e., dependence on history, determined by tw and temperature; (b) nonmonotonic, where a memory of the sample history is lost. The conditions that separate the two regimes also have been determined.
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The paper presents the results of indoor radon concentration survey in 201 homes and offices in Niska Banja (the Spa of Nis), a well-known health resort and a spa in the South-East of Serbia. Radon indoor concentrations were determined by active charcoal method, according to standard EPA procedure. The indoor radon concentrations were in the range of up to 200 Bq/m(3) (47%), from 200-600 Bq/m(3) (26%) and over 600 Bq/m(3) (27%). Three areas of extremely high average radon concentrations were found (1,340-4,340 Bq/m(3)), with a maximum above 13,000 Bq/m(3). The content of natural radionuclides ((226)Ra, (214)Pb, (214)Bi, (235)U, (228)Ac, (212)Pb, (212)Bi, (208)Tl, (40)K) and (137)Cs, as well as the content of total uranium, thorium and potassium in mud used in peloidotherapy in the Health Institute "Niska Banja" was determined, too. The activities of the radionuclides were determined on an HPGe detector, by standard gamma spectroscopy. The results indicated considerably high amounts of total uranium and thorium (0.021 g/kg mud and 0.003 g/kg mud, respectively), due to the karsts origin of the soil.
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Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental , Radioisótopos/análise , Radônio/análise , Humanos , Radioisótopos de Potássio/análise , Medição de Risco , Tório/análise , Urânio/análise , Ventilação , IugosláviaRESUMO
Leaves of linden (Tilia tomentosa L. and Tilia cordata Mill.) and horse chestnut (Aesculus hippocastanum L.) were analysed as biomonitors of radionuclides in urban air. Samples of soils, leaves and aerosols were collected in Belgrade, Serbia. Activities of (137)Cs, (40)K, (210)Pb and (7)Be in the samples were measured on an HPGe detector by standard gamma spectrometry. "Soil-to-leaves" transfer factors were calculated. Student's t test and linear Pearson correlation coefficients were used for statistical analysis. Differences in local conditions at the sampling sites were not significant, and the mechanisms of the radionuclides' accumulation in both plant species are similar. Ceasium-137 was detected in some of the leaf samples only. Transfer factors for (137)Cs and (40)K were (0.03-0.08) and 1.3, respectively. The concentrations of (210)Pb and (7)Be in leaves were higher in autumn than in spring, and there were some similarities in their seasonal patterns in leaves and in air. Weak to medium correlation was obtained for the (210)Pb and (7)Be activities in leaves and aerosols. Large positive correlation was obtained for the (210)Pb activities in linden leaves and the mean activity in aerosols for the preceding months. Different primary modes of radionuclides accumulation in leaves were observed. Since large positive correlation was obtained for the (210)Pb activity in linden leaves and the mean in aerosols for the preceding months, mature linden leaves could be used as biomonitors of recent (210)Pb activity in air.
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Poluentes Radioativos do Ar/análise , Folhas de Planta/química , Monitoramento de Radiação/métodos , Radioisótopos/análise , Berílio/análise , Radioisótopos de Césio/análise , Cidades , Radioisótopos de Chumbo/análise , Radioisótopos de Potássio/análise , SérviaRESUMO
Concentrations of beryllium-7 ((7)Be), lead-210 ((210)Pb) and caesium-137 ((137)Cs) were measured at two sites in the city of Belgrade (Serbia). One monitoring site was located in the central city area with heavy traffic and the other within the Institute of Nuclear Sciences Vinca, in the suburbs. Presented data cover the period 2004-9. Activity of the radionuclides was determined on an HPGe detector (Canberra, relative efficiency 23 %) by standard gamma spectrometry. Activities of (7)Be and (210)Pb exhibit a similar seasonal pattern. The mean monthly concentrations of (7)Be did not exceed 7 mBq m(-3). The maxima are correlated with the seasonal increase in temperature, whereas the minima are linearly correlated with the amount of precipitation. The activity of (210)Pb was below 0.9 mBq m(-3). The activities of both radionuclides were very low in winters and were largely affected by precipitation and snow coverage. Concentrations of (137)Cs were mainly below the limit of detection.