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AbstractAluminum (Al) is a known neurotoxic trace element linked to Alzheimer’s disease (AD). Naltrexone, an opioid antagonist, has shown promising effects in reducing neuroinflammation at lower doses than those prescribed for addiction. This study aimed to determine the neuroprotective effects of naltrexone on Al-induced neurotoxicity in an in vitro AD model. The SH-SY5Y cells were first cultivated in a standard growth medium. Subsequently, the cells were induced to differentiate by decreasing the concentration of fetal bovine serum and introducing retinoic acid (RA) into the culture media. Subsequently, the inclusion of brain-derived neurotrophic factor (BDNF) was implemented in conjunction with RA. The process of differentiation was concluded on the seventh day. Study groups (n = 3) were designed as the control group, naltrexone group, Al group, Al-Nal group, Alzheimer’ model (AD) group, Alzheimer model + Al-exposed group (AD-Al), Alzheimer model + Nal applied group (AD-Nal) and Alzheimer model + Al-exposed + Nal applied group (AD-Al-Nal). Hyperphosphorylated Tau protein as the specific marker of AD was measured in all groups. Glycogen synthase kinase-3 (GSK-3)β, Protein phosphatase 2A (PP2A), Akt and Wnt signaling pathways were analyzed comparatively. In addition, oxidative stress parameters (total antioxidant capacity, lipid peroxidase, protein carbonyl and reactive oxygen species) were measured comparatively in the study groups. The results showed that naltrexone reduced hyperphosphorylated tau protein levels by regulating GSK-3β, PP2A, Akt and Wnt signaling. Also, exposure to naltrexone decreased oxidative stress parameters. Based on these results, naltrexone shows promise as a potential therapy for AD, subject to additional clinical assessments. [ABSTRACT FROM AUTHOR]

Hemophagocytic lymphohistiocytosis (HLH) is a rare, albeit potentially fatal, condition in which fever, hepatosplenomegaly, and cytopenia predominate the clinical picture. Although it may be primary, it may also develop secondary to various etiologies. Herein, we aimed to report a patient who was diagnosed with pulmonary tuberculosis, developed fever and cytopenia during follow-up, and received immunomodulatory therapy together with antituberculosis therapy for the diagnosis of HLH. Sequencing of PRF1 showed heterozygous mutation. Although primary HLH has been detected in infants and children, genetic mutation of genes should be considered a differential diagnosis of HLH even in the adolescent. [ABSTRACT FROM AUTHOR]

Different allotropes of phosphorene are possible of which black and blue phosphorus are the most stable. While blue phosphorus has isotropic properties, black phosphorus is strongly anisotropic in its electronic and optical properties due to its anisotropic crystal structure. In this work, we systematically investigated the lattice thermal properties of black and blue phosphorene by using first-principles calculations based on the quasiharmonic approximation approach. Similar to the optoelectronic and electronic properties, we predict that black phosphorene has highly anisotropic thermal properties, in contrast to the blue phase. The linear thermal expansion coefficients along the zigzag and armchair direction differ up to 20% in black phosphorene. The armchair direction of black phosphorene is more expandable as compared to the zigzag direction and the biaxial expansion of blue phosphorene under finite temperature. Our comparative analysis reveals that the inclusion of finite-temperature effects makes the blue phase thermodynamically more stable over the black phase above 135 K. [ABSTRACT FROM AUTHOR]

Carbon-based molecular semiconductors are explored for application in spintronics because their small spin-orbit coupling promises long spin lifetimes. We calculate the electronic transport from first principles through spin valves comprising bi- and tri-layers of the fullerene molecules C60 and C70, sandwiched between two Fe electrodes. The spin polarization of the current, and the magnetoresistance depend sensitively on the interactions at the interfaces between the molecules and the metal surfaces. They are much less affected by the thickness of the molecular layers. A high current polarization (CP>90%) and magnetoresistance (MR>100%) at small bias can be attained using C70 layers. In contrast, the current polarization and the magnetoresistance at small bias are vanishingly small for C60 layers. Exploiting a generalized Jullière model we can trace the differences in spin-dependent transport between C60 and C70 layers to differences between the molecule-metal interface states. These states also allow one to interpret the current polarization and the magnetoresistance as a function of the applied bias voltage. [ABSTRACT FROM AUTHOR]

Using first principles calculations we showed that the electronic and optical properties of single-layer black phosphorus (BP) depend strongly on the applied strain. Due to the strong anisotropic atomic structure of BP, its electronic conductivity and optical response are sensitive to the magnitude and the orientation of the applied strain. We found that the inclusion of many body effects is essential for the correct description of the electronic properties of monolayer BP; for example, while the electronic gap of strainless BP is found to be 0.90 eV by using semilocal functionals, it becomes 2.31 eV when many-body effects are taken into account within the G0W0 scheme. Applied tensile strain was shown to significantly enhance electron transport along zigzag direction of BP. Furthermore, biaxial strain is able to tune the optical band gap of monolayer BP from 0.38 eV (at -8% strain) to 2.07 eV (at 5.5%). The exciton binding energy is also sensitive to the magnitude of the applied strain. It is found to be 0.40 eV for compressive biaxial strain of -8%, and it becomes 0.83 eV for tensile strain of 4%. Our calculations demonstrate that the optical response of BP can be significantly tuned using strain engineering which appears as a promising way to design novel photovoltaic devices that capture a broad range of solar spectrum. [ABSTRACT FROM AUTHOR]

Using density functional theory, we obtain the mechanical and thermal properties of MX2 monolayers (where M=Cr, Mo, W and X=O, S, Se, Te). The C-centered phonon frequencies (i.e., A1, A00 2, E0, and E00), relative frequency values of A1, and E0 modes, and mechanical properties (i.e., elastic constants, Young modulus, and Poisson's ratio) display a strong dependence on the type of metal and chalcogenide atoms. In each chalcogenide (metal) group, transition-metal dichalcogenides (TMDCs) with W (O) atom are found to be much stiffer. Consistent with their stability, the thermal expansion of lattice constants for TMDCs with O (Te) is much slower (faster). Furthermore, in a heterostructure of these materials, the difference of the thermal expansion of lattice constants between the individual components becomes quite tiny over the whole temperature range. The calculated mechanical and thermal properties show that TMDCs are promising materials for heterostructures. [ABSTRACT FROM AUTHOR]

The energy level alignment in metal-organic and organic-organic junctions of the widely used materials tris-(8-hydroxyquinoline)aluminum (Alq3) and 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) is investigated. The measured alignment schemes for single and bilayer films of Alq3 and NTCDA are interpreted with the integer charge transfer (ICT) model. Single layer films of Alq3 feature a constant vacuum level shift of ∼0.2-0.4 eV in the absence of charge transfer across the interface. This finding is attributed to the intrinsic dipole of the Alq3 molecule and (partial) ordering of the molecules at the interfaces. The vacuum level shift changes the onset of Fermi level pinning, as it changes the energy needed for equilibrium charge transfer across the interface. [ABSTRACT FROM AUTHOR]

Abstract: Substantial potential steps ∼0.5eV are frequently observed in organic multilayers of donor and acceptor molecules. Often such potential steps depend on the order in which the individual layers are deposited, or on which substrate they are deposited. In this paper we outline a model for these potential steps, based upon integer charge transfer between donors and acceptors, charge equilibration across the multilayer, and simple electrostatics. Each donor, acceptor, or substrate material is characterized by a pinning level, and the potential profile can be deduced from the sequential order of the layers, and the differences between their pinning levels. For particular orderings we predict that intrinsic potential differences lead to electric fields across individual layers, which may falsely be interpreted as band bending. [Copyright &y& Elsevier]

The atomic structure of interfaces between conducting electrodes and molecular organic materials varies considerably. Yet experiments show that pinning of the Fermi level, which is observed at such interfaces, does not depend upon the structural details. In this letter, we develop a general model to explain Fermi level pinning, and formulate simple expressions for the pinning levels, based upon integer charge transfer between the conductor and the molecular layer. In particular, we show that DFT calculations give good values for the pinning levels. [ABSTRACT FROM AUTHOR]

Iridium (Ir) modified Silicon (Si) (001) surface is studied with Scanning Tunneling Microscopy/Spectroscopy (STM/STS) and Density Functional Theory (DFT). A model for Ir-silicide nanowires based on STM images and ab-initio calculations is proposed. According to our model, the Ir adatom is on the top of the substrate dimer row and directly binds to the dimer atoms. I-V curves measured at 77 K shows that the nanowires are metallic. DFT calculations confirm strong metallic nature of the nanowires. [ABSTRACT FROM AUTHOR]

To investigate coronavirus disease 2019 (COVID-19) in infants aged 0 to 3 months because there is currently a significant gap in the literature on the subject. A cross-sectional study was conducted with the involvement of 19 medical centers across Turkey and 570 infants. The majority of the patients were male (58.2%), and the three most common symptoms were fever (78.2%), cough (44.6%), and feeding intolerance (39.9%). The results showed that a small percentage of infants had positive blood (0.9%) or urine cultures (10.2%). Most infants presented with fever (78.2%). Children without underlying conditions (UCs) had mostly a complicated respiratory course and a normal chest radiography. Significant more positive urine culture rates were observed in infants with fever. A higher incidence of respiratory support requirements and abnormal chest findings were seen in infants with chronic conditions. These infants also had a longer hospital stay than those without chronic conditions. Conclusions: Our study discloses the clinical observations and accompanying bacterial infections found in infants aged under 3 months with COVID-19. These findings can shed light on COVID-19 in infancy for physicians because there is limited clinical evidence available. What is Known: • COVID-19 in infants and older children has been seen more mildly than in adults. • The most common symptoms of COVID-19 in infants are fever and cough, as in older children and adults. COVID-19 should be one of the differential diagnoses in infants with fever. What is New: • Although most infants under three months had fever, the clinical course was uneventful and respiratory complications were rarely observed in healthy children. • Infants with underlying conditions had more frequent respiratory support and abnormal chest radiography and stayed longer in the hospital. [ABSTRACT FROM AUTHOR]

Mushroom production is highly affected by green mould disease, which causes severe losses worldwide. This study aimed to characterize Trichoderma spp. isolates collected from Agaricus bisporus‐ and Pleurotus ostreatus‐growing facilities based on their molecular features and evaluate their aggressiveness in mushroom production in vitro and in vivo. Fifty‐six Trichoderma isolates from mushroom farms in Aegean and Marmara regions were analysed for molecular characteristics. In a phylogenetic tree constructed based on internal transcribed spacer (ITS) and tef1 sequences, they were classified into five groups, which included Trichoderma spp. such as T. aggressivum, T. europaeum, T. pleuroticola, T. virens, T. harzianum and T. afroharzianum. Phylogenetic analyses revealed that tef1 sequences could distinguish between T. aggressivum f. aggressivum and T. aggressivum f. europaeum more specifically. Consequently, tef1 sequence variation identified 15 T. aggressivum f. europaeum isolates compared with ITS sequence variation. In vitro conditions based on the dual‐culture tests of the mycelial growth of A. bisporus showed growth inhibition between 50% and 75% depending on the isolates. Two Trichoderma isolates with different ITS and tef1 sequences (3/9 and 7/5 isolates, respectively) and more lytic and mycoparasitic activities were analysed further to determine their effects on yield and mushroom quality parameters. Therefore, T. aggressivum f. aggressivum is not the only species that affects mushroom production, and T. aggressivum f. aggressivum and T. aggressivum f. europaeum isolates significantly (p < 0.05) inhibited A. bisporus growth in vitro and in vivo. [ABSTRACT FROM AUTHOR]

The effect of the number of stacking layers and the type of stacking on the electronic and optical properties of bilayer and trilayer black phosphorus are investigated by using first-principles calculations within the framework of density functional theory. We find that inclusion of many-body effects (i.e., electron-electron and electron-hole interactions) modifies strongly both the electronic and optical properties of black phosphorus. While trilayer black phosphorus with a particular stacking type is found to be a metal by using semilocal functionals, it is predicted to have an electronic band gap of 0.82 eV when many-body effects are taken into account within the G0W0 scheme. Though different stacking types result in similar energetics, the size of the band gap and the optical response of bilayer and trilayer phosphorene are very sensitive to the number of layers and the stacking type. Regardless of the number of layers and the type of stacking, bilayer and trilayer black phosphorus are direct band gap semiconductors whose band gaps vary within a range of 0.3 eV. Stacking arrangements that are different from the ground state structure in both bilayer and trilayer black phosphorus exhibit significant modified valence bands along the zigzag direction and result in larger hole effective masses. The optical gap of bilayer (trilayer) black phosphorus varies by 0.4 (0.6) eV when changing the stacking type. The calculated binding energy of the bound exciton hardly changes with the type of stacking and is found to be 0.44 (0.30) eV for bilayer (trilayer) phosphorous. [ABSTRACT FROM AUTHOR]

This multi-center point prevalence study evaluated children who were diagnosed as having coronavirus disease 2019 (COVID-19). On February 2nd, 2022, inpatients and outpatients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were included in the study from 12 cities and 24 centers in Turkey. Of 8605 patients on February 2nd, 2022, in participating centers, 706 (8.2%) had COVID-19. The median age of the 706 patients was 92.50 months, 53.4% were female, and 76.7% were inpatients. The three most common symptoms of the patients with COVID-19 were fever (56.6%), cough (41.3%), and fatigue (27.5%). The three most common underlying chronic diseases (UCDs) were asthma (3.4%), neurologic disorders (3.3%), and obesity (2.6%). The SARS-CoV-2-related pneumoniae rate was 10.7%. The COVID-19 vaccination rate was 12.5% in all patients. Among patients aged over 12 years with access to the vaccine given by the Republic of Turkey Ministry of Health, the vaccination rate was 38.7%. Patients with UCDs presented with dyspnea and pneumoniae more frequently than those without UCDs (p < 0.001 for both). The rates of fever, diarrhea, and pneumoniae were higher in patients without COVID-19 vaccinations (p = 0.001, p = 0.012, and p = 0.027). Conclusion: To lessen the effects of the disease, all eligible children should receive the COVID-19 vaccine. The illness may specifically endanger children with UCDs. What is Known: • Children with COVID-19 mainly present with fever and cough, as in adults. • COVID-19 may specifically threaten children with underlying chronic diseases. What is New: • Children with obesity have a higher vaccination rate against COVID-19 than children without obesity. • Among unvaccinated children, fever and pneumoniae might be seen at a higher ratio than among vaccinated children. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenides (TMDs) are considered as promising candidates for next generation of electronic and optoelectronic devices. To make use of these materials, for instance in field effect transistor applications, it is mandatory to know the detailed properties of contacts of such TMDs with metal electrodes. Here, we investigate the role of the contact structure on the electronic and transport properties of metal-MoSe2 interfaces. Two different contact types, namely face and edge contacts, are studied. We consider both low (Sc) and high (Au) work function metals in order to thoroughly elucidate the role of the metal work function and the type of metal. First principles plane wave calculations and transport calculations based on nonequilibrium Green's function formalism reveal that the contact type has a large impact on the electronic and transport properties of metal-MoSe2 interfaces. For the Sc electrode, the Schottky barrier heights are around 0.25 eV for face contact and bigger than 0.6 eV for edge contact. For the Au case, we calculate very similar barrier heights for both contact types with an average value of 0.5 eV. Furthermore, while the face contact is found to be highly advantageous as compared to the edge contact for the Sc electrode, the latter contact becomes a better choice for the Au electrode. Our findings provide guidelines for the fabrication of TMD-based devices. [ABSTRACT FROM AUTHOR]

Objective: In this study, we sought to describe the clinical, laboratory, and genetic characteristics of patients diagnosed with primary hemophagocytic lymphohistiocytosis. Thus, we aimed to evaluate the early diagnosis and appropriate treatment options for pediatric hemophagocytic lymphohistiocytosis patients. Materials and Methods: Medical records of 9 patients diagnosed with primary hemophagocytic lymphohistiocytosis between November 2013 and December 2019 were analyzed retrospectively. Clinical, genetic, and laboratory characteristics, family histories, initial complaints, physical examination findings, age at diagnosis, treatment choices, and clinical follow-up of all patients were investigated. Results: The mean age at diagnosis was 11 months (range: 1.5 months to 17 years). Genetic analysis was performed in all patients, and a disease-related mutation was detected in 8 (89%) of them. Among clinical features, 6 (66%) patients had fever, 5 (56%) had splenomegaly, 4 (44%) had lymphadenopathy, 4 (44%) had skin rash, and 4 (44%) had neurological findings. Hemophagocytosis was observed in the bone marrow samples of 6 (66%) patients. Disease remission was achieved in 7 (78%) patients. Hematopoietic stem cell transplantation was performed in 7 (78%) patients. Conclusion: Hemophagocytic lymphohistiocytosis may present with different clinical symptoms that can cause a significant diagnostic delay. The only curative treatment option in primary hemophagocytic lymphohistiocytosis patients is hematopoietic stem cell transplantation. The chemotherapy should be started as early as possible, in order to achieve a disease remission. Patients should be referred to the appropriate bone marrow transplant center for hematopoietic stem cell transplantation as soon as they reach the disease remission. [ABSTRACT FROM AUTHOR]

In this study, we aimed to evaluate possible toxic effects of thimerosal, aluminum and combination of thimerosal and aluminum in SH-SY5Y cells. Inhibitory concentrations were determined by MTT assay; reactive oxygen species (ROS) were determined by a fluorometric kit and antioxidant/oxidant parameters were measured by spectrophotometric kits. Nuclear factor erythroid 2-associated factor 2 (Nrf2), norepinephrine (NE), dopamine transporter (DAT) and dopamine beta β-hydroxylase (DBH) levels were measured by sandwich ELISA kits while 8-hydroxy deoxyguanosine (8-OHdG) and dopamine levels were determined by competitive ELISA kits. Thimerosal (1.15 μM) and aluminum (362 μM) were applied to cells at inhibitory concentrations 20 (IC20s) for 24 h. ROS increased significantly in cells aluminum- and aluminum+thimerosal-treated cells. Glutathione levels decreased in aluminum group while total antioxidant capacity and protein oxidation levels increased significantly in aluminum and aluminum+thimerosal groups. Lipid peroxidation increased significantly in groups treated with aluminum and aluminum+thimerosal. Nrf2 levels and DNA damage were significantly higher in all groups while dopamine levels significantly increased in cells treated with thimerosal and aluminum+thimerosal, DAT levels were found to be higher in all experimental groups compared to the control. These findings showed that both thimerosal and aluminum can change oxidant/antioxidant status, cause DNA damage, alter dopamine and DAT levels. Changes seen in cells treated with combined exposure to aluminum and thimerosal are more pronounced. Special care should be taken while vaccinating sensitive populations and safer alternatives for aluminum and thimerosal should used. [ABSTRACT FROM AUTHOR]

Objectives: In this study, we present our clinical severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) experience in patients with childhood rheumatic disease during novel coronavirus-2019 (COVID-19) pandemic. Patients and methods: A total of 87 patients (50 males, 37 females; median age: 12 years; range, 6.6 to 16 years) suspected of having COVID-19 at our pediatric rheumatology clinic between March 11th and October 15th 2020 were retrospectively analyzed. Demographic and clinical features, treatments, laboratory results, imaging findings, and clinical outcomes of the patients diagnosed with COVID-19 and/or multisystem inflammatory syndrome in children (MIS-C) were retrieved from the medical records. The diagnosis of SARS-CoV-2 infection was made based on the reverse transcriptase-polymerase chain reaction test. Results: The most common rheumatic diseases were juvenile idiopathic arthritis and familial Mediterranean fever (35.6% and 34.5%, respectively). Twenty-six of these patients were treated with biological disease-modifying anti-rheumatic drugs. SARS-CoV-2 infection was tested as positive in 84 (96.5%) patients. Also, 51 (58.6%) patients had an epidemiological contact to a person with COVID-19. Eighteen patients met the clinical criteria and diagnosed with MIS-C. The COVID-19 outbreak also caused exacerbation of systemic disease in 56 children due to medication cessation, postponed drug switch, or recurrent viral infection. Conclusion: Children with rheumatic disease do not appear to present a higher risk of severe COVID-19. The immunosuppressive treatments can be adjusted in case of infection; otherwise, it is not recommended to interrupt the treatments. Physicians should be cautious about the hyperinflammatory syndrome associated with COVID-19 in rheumatic children, which may be severe in this group of patients and may be confused with primary diseases. [ABSTRACT FROM AUTHOR]

The frequency of bacterial factors causing central nervous system infections has decreased as a result of the development of our national immunization program. In this study, it is aimed to obtain the data of our local surveillance by defining the viral etiology in cases diagnosed with meningoencephalitis for 1 year. Previously healhty 186 children, who applied with findings suggesting viral meningoencephalitis to 8 different tertiary health centers between August 2018 and August 2019, in Istanbul, were included. The cerebrospinal fluid (CSF) sample was evaluated by polymerase chain reaction. The M:F ratio was 1.24 in the patient group, whose age ranged from 1 to 216 months (mean 40.2 ± 48.7). Viral factor was detected in 26.8%. Enterovirus was the most common agent (24%) and followed by Adenovirus (22%) and HHV type 6 (22%). In the rest of the samples revealed HHV type 7 (10%), EBV (6%), CMV (6%), HSV type 1 (6%), Parvovirus (4%) and VZV (2%). The most common symptoms were fever (79%) and convulsions (45.7%). Antibiotherapy and antiviral therapy was started 48.6% and 4% respectively. Mortality and sequela rate resulted 0.53% and 3.7%, respectively. This highlights the importance of monitoring trends in encephalitis in Turkey with aview to improving pathogen diagnosis for encephalitis and rapidly identifying novel emerging encephalitis-causing pathogens that demand public health action especially in national immunisation programme. [ABSTRACT FROM AUTHOR]

Objective: 5.5-12.8% of drug intoxications attending to the emergency departments are admitted to the intensive care unit (ICU). In our country, this rate can reach up to 37%. Most of these patients do not receive any treatment that requires intensive care, but they are admitted for observation only. The aim of this study was to retrospectively examine the drug intoxication patients in ICU and to determine how many of these patients really needed intensive care admission. Materials and Methods: Cases of drug intoxications admitted to our intensive care unit between March 2016 and March 2018 were retrospectively evaluated. Demographic data, toxicological characteristics, vital signs at admission, presence of ICU admission criteria, intensive care treatments, duration of stay in ICU, prognosis and mortalities were investigated retrospectively. Results: Data of 130 patients (40 male/90 female) were evaluated. When drug types were evaluated, multiple drug intake was the first followed by antidepressants and anticonvulsants respectively. At the time of admission to ICU, vital signs of 120 patients were stable. Twenty seven patients had at least one ICU admission criteria. 4 of these patients were on mechanical ventilation; inotropicvasopressor treatment was applied in 3 patients. The number of patients requiring treatment that has to be performed in ICU was 8. No complication developed in patients whose vital signs were stable on admission and did not have any of the ICU admission criteria. Seven of the patients were referred to the ward and one was to the nephrology intensive care unit, 122 of them were discharged home directly. The total length of stay in the ICU was 251.5 days. Conclusion: We think that constituting clear criteria for admission to ICU for patients presenting with drug intoxications and follow-up of some patients in the emergency departments or wards will reduce unnecessary bed occupation in ICUs. [ABSTRACT FROM AUTHOR]

In this study, we predicted two new stable metallic Re C based monolayer structures with a rectangular (r-ReC 2 ) and a hexagonal (h-Re 2 C) crystal symmetry using first-principle calculations based on density functional theory. Our results obtained from mechanical and phonon calculations and high-temperature molecular dynamic simulations clearly proved the stability of these two-dimensional (2D) crystals. Interestingly, Re C monolayers in common transition metal carbide structures (i.e. MXenes) were found to be unstable, contrary to expectations. We found that the stable structures, i.e. r-ReC 2 and h-Re 2 C, display superior mechanical properties over the well-known 2D materials. The Young’s modulus for r-ReC 2 and h-Re 2 C are extremely high and were calculated as 351 (1310) and 617 (804) N/m (GPa), respectively. Both materials have larger Young’s modulus values than the most of the well-known 2D materials. We showed that the combination of the short strong directional p - d bonds, the high coordination number of atoms in the unit-cell and high valence electron density result in strong mechanical properties. Due to its crystal structure, the r-ReC 2 monolayer has anisotropic mechanical properties and the crystallographic direction parallel to the C 2 dimers is stiffer compared to perpendicular direction due to strong covalent bonding within C 2 dimers. h-Re 2 C was derived from the corresponding bulk structure for which we determined the critical thickness for the dynamically stable bulk-derived monolayer structures. In addition, we also investigated the electronic of these two stable structures. Both exhibit metallic behavior and Re-5d orbitals dominate the states around the Fermi level. Due to their ultra high mechanical stability and stiffness, these novel Re C monolayers can be exploited in various engineering applications. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Postnatal CMV (cytomegalovirus) infection in the premature infants is most often transmitted with infected breast milk. The other routes of transmission are blood transfusion and genital secretions. Diagnosis is made by PCR or viral culture of urine, blood, or other body secretions after the first 3 weeks of life. It is mostly asymptomatic in term infants. CMV infection may cause sepsis and many clinical signs in premature infants. There are a few reports of premature infants with CMV sepsis in the literature. CASE REPORTS: Both of our cases were premature infants weighing less than 1000 g and born with ceaserean section. Since both of the mothers did not have breast milk, infants were fed with premature formula. They were transfused with erythrocyte suspension more than once. The first case has developed feeding intolerance and splenomegaly, the second case had increased oxygen demand and invasive mechanical ventilation support at the end of the second month of life. Laboratory findings showed cholestasis, thrombocytopenia, elevated transaminases and acute phase reactants. Blood CMV IgM and CMV DNA PCR were positive in both cases. Ganciclovir treatment was started. The first case had improvement in clinical and laboratory findings in 2 weeks, the second case had improvement in 6th week of the treatment. None of the patiens developed neurological sequelae or hearing loss. CONCLUSİON: We aimed to remind that postnatal CMV infection should be suspected in preterm infants who developed sepsis later than fist 3 weeks of life. [ABSTRACT FROM AUTHOR]

In this study, we investigated physical and electronic properties of possible two-dimensional structures formed by Si (silicon) and Ir (iridium). To this end, different plausible structures were modeled by using density functional theory and the cohesive energies calculated for the geometry of optimized structures, with the lowest equilibrium lattice constants. Among several candidate structures, we identified three mechanically (via elastic constants and Young's modulus), dynamically (via phonon calculations), and thermodynamically stable iridium silicide monolayer structures. The lowest energy structure has a chemical formula of Ir2Si4 (called r-IrSi2), with a rectangular lattice (Pmmn space group). Its cohesive energy was calculated to be −0.248 eV (per IrSi2 unit) with respect to bulk Ir and bulk Si. The band structure indicates that the Ir2Si4 monolayer exhibits metallic properties. Other stable structures have hexagonal (P-3m1) and tetragonal (P4/nmm) cell structures with 0.12 and 0.20 eV/f.u. higher cohesive energies, respectively. Our calculations showed that Ir-Si monolayers are reactive. Although O2 molecules exothermically dissociate on the surface of the free-standing iridium silicide monolayers with large binding energies, H2O molecules bind to the monolayers with a rather weak interaction. [ABSTRACT FROM AUTHOR]

• Chromium silicide (CrSi 2) crystallites were grown on Si(110) surface. • At low annealing temperatures, the surface had the grains of epitaxially grown CrSi 2. The burgers vector is 1 2 〈 11 − 1 〉. • Annealing at higher temperatures led to the formation of CrSi 2 crystallites. • The crystallites were metallic although the bulk is a semiconductor with a bandgap of about 0.35 eV. • The LDOS curves measured on the crystallites showed that they were metallic even though the bulk of the crystallite is a semiconductor. • Ab-initio DFT simulations confirmed the metallic nature of the crystallites. C rSi 2 is an important refractory metal-silicide with high thermal power and a narrow bandgap which makes it a suitable material for high-temperature thermoelectric applications. The present work investigates the early stages of the growth of Cr film on Si(110) and its electronic properties by combining Scanning Tunneling Microscopy and Density Functional Theory. Cr atoms deposited on Si(110) formed grains of CrSi 2 with interfacial dislocations along 1 2 〈 11 − 1 〉 Burgers vectors. After annealing at 1100°C, disconnected CrSi 2 crystallites emerged. The crystallites had well-defined facets. Scanning tunneling spectroscopy measurements showed that the crystallites were metallic. Simulated DOS data of the facets also confirmed the metallic nature of the crystallites. Image, graphical abstract [ABSTRACT FROM AUTHOR]