Exploring the possibility of chemisorption of ethylene on graphene with and without defects

The effect of structural defects on graphene interaction with other molecules is of high interest. In this study, the interaction of ethylene molecules with pristine graphene (PG) and defective graphenes including single (SVG) and double (DVG) vacancies, were investigated using dispersion-corrected periodic density functional theory (DFT). We used various pairs of pseudopotentials and dispersion-corrected methods to calculate the exchange-correlation energies and long-range energies, respectively. We conducted the calculations in the ethylene-graphene equilibrium distance where vdW interaction as a long-range interaction was dominant. Both adsorption and deformation energies were calculated to examine the possibility of ethylene chemisorption. It was found that there is a critical distance from the graphene surface, where the nature of adsorption of adsorbate molecule changes from physisorption to the possible chemisorption depending on the energetical costly distortion induced in adsorbate molecule. In the case of ethylene adsorption on the graphene structures studied here, the mentioned critical distances follow the order SVG < DVG < PG. However, in the range of vdW domination and in comparison with PG, ethylene interacts more with SVG due to the presence of a dangling bond and interacts less with DVG due to the presence of a hole. Furthermore, the interactions of ethylene with reconstructed trivacancy were studied. Moreover, all possible orientations for ethylene adsorption on graphene structures were considered and energetically compared. All calculations were done on fully optimized reconstructed geometries of vacancies with structural characteristics, i.e., reconstruction length and formation energies comparable to those reported in the literature

Comparison of the Frequency and Complications of Inappropriate Antidiuretic Hormone Secretion in Patients with Septic and Aseptic Meningitis

ObjectiveDue to the high prevalence of syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH). This study was carried out to evaluate the prevalence and relevant parameters of SIADH in children with septic and aseptic memingitis hospitalized at Kashan Shahid Beheshti Hospital between 1996 and 2006.Materials &amp; MethodsThis descriptive study was conducted on 230 patients with meningitis hospitalized in the pediatric wards of Kashan Shahid Beheshti Hospital between 1996 and 2006. Relevant information (age, gender, type of meningitis, serum sodium and potassium, urine specific gravity (USG), blood sugar, blood urea nitrogen, serum creatinin, hydration condition) was collected from patients' records. Data was analyzed using Mann-Whitney and K2 tests.ResultsOut of 230 patients with meningitis, 33 had incomplete records and only 197 patients were recruited for this study. Sixty eight cases (34.5%) suffered from SIADH. It was more frequent among 1-2 year old  children.According to this research, SIADH was diagnosed in 57% of the 121 patients with hyponatremia, 58.7% of the 167 patients with USG &gt; 1.004, 74% of the 93 patients with serum osmolity &lt; 280 mOs/L and 100% of the patients with BUN &lt; 10 mg%.ConclusionDue to the high prevalence of SIADH in septic and aseptic meningitis and its complication, it is recommended to restrict fluid therapy and monitor serum sodium, urine specific gravity and other diagnostic tests for SIADH.Keywords: Hyponatremia; Meningitis; SIADH, Septic, Asepti

Exhaled nitric oxide is not a biomarker for idiopathic pulmonary arterial hypertension or for treatment efficacy

BACKGROUND: Idiopathic pulmonary arterial hypertension (IPAH) is a fatal illness. Despite many improvements in the treatment of these patients, there is no unique prognostic variable available to track these patients. The aim of this study was to evaluate the association between fractional exhaled nitric oxide (FeNO) levels, as a noninvasive biomarker, with disease severity and treatment outcome. METHODS: Thirty-six patients (29 women and 7 men, mean age 38.4 ± 11.3 years) with IPAH referred to the outpatient's clinic of Masih Daneshvari Hospital, Tehran, Iran, were enrolled into this pilot observational study. Echocardiography, six-minute walking test (6MWT), FeNO, brain natriuretic peptide (BNP) levels and the functional class of patients was assessed before patients started treatment. Assessments were repeated after three months. 30 healthy non-IPAH subjects were recruited as control subjects. RESULTS: There was no significant difference in FeNO levels at baseline between patients with IPAH and subjects in the control group. There was also no significant increase in FeNO levels during the three months of treatment and levels did not correlate with other disease measures. In contrast, other markers of disease severity were correlated with treatment effect over the three months. CONCLUSION: FeNO levels are a poor non-invasive measure of IPAH severity and of treatment response in patients in this pilot study

Rational Molecular Design Enables Efficient Blue TADF−OLEDs with Flexible Graphene Substrate

Observation of thermally activated delayed fluorescence (TADF) in conjugated systems redefined the molecular design approach to realize highly efficient organic light emitting diodes (OLEDs) in the early 2010s. Enabling effective reverse intersystem crossing (RISC) by minimizing the difference between singlet and triplet excited state energies (ΔEST) is proven to be a widely applicable and fruitful approach, which results in remarkable external quantum efficiencies (EQE). The efficacy of RISC in these systems is mainly dictated by the first-order mixing coefficient (λ), which is proportional to spin-orbit coupling (HSO) and inversely proportional to ΔEST. While minimizing ΔEST has been the focus of the OLED community over the last decade, the effect of HSO in these systems is largely overlooked. Here, molecular systems with increased HSO are designed and synthesized by substituting selected heteroatoms of high-performance TADF materials with heavy-atom selenium. A new series of multicolor TADF materials with remarkable EQEs are achieved. One of these materials, SeDF-B, results in pure blue emission with EQEs approaching 20%. Additionally, flexible graphene-based electrodes are developed for OLEDs and revealed to have similar performance as standard indium tin oxide (ITO) in most cases. These devices are the first report of TADF based OLEDs that utilize graphene-based anodes

Global, regional, and national cancer incidence, mortality, years of life lost, years lived with disability, and disability-Adjusted life-years for 29 cancer groups, 1990 to 2017 : A systematic analysis for the global burden of disease study

Importance: Cancer and other noncommunicable diseases (NCDs) are now widely recognized as a threat to global development. The latest United Nations high-level meeting on NCDs reaffirmed this observation and also highlighted the slow progress in meeting the 2011 Political Declaration on the Prevention and Control of Noncommunicable Diseases and the third Sustainable Development Goal. Lack of situational analyses, priority setting, and budgeting have been identified as major obstacles in achieving these goals. All of these have in common that they require information on the local cancer epidemiology. The Global Burden of Disease (GBD) study is uniquely poised to provide these crucial data. Objective: To describe cancer burden for 29 cancer groups in 195 countries from 1990 through 2017 to provide data needed for cancer control planning. Evidence Review: We used the GBD study estimation methods to describe cancer incidence, mortality, years lived with disability, years of life lost, and disability-Adjusted life-years (DALYs). Results are presented at the national level as well as by Socio-demographic Index (SDI), a composite indicator of income, educational attainment, and total fertility rate. We also analyzed the influence of the epidemiological vs the demographic transition on cancer incidence. Findings: In 2017, there were 24.5 million incident cancer cases worldwide (16.8 million without nonmelanoma skin cancer [NMSC]) and 9.6 million cancer deaths. The majority of cancer DALYs came from years of life lost (97%), and only 3% came from years lived with disability. The odds of developing cancer were the lowest in the low SDI quintile (1 in 7) and the highest in the high SDI quintile (1 in 2) for both sexes. In 2017, the most common incident cancers in men were NMSC (4.3 million incident cases); tracheal, bronchus, and lung (TBL) cancer (1.5 million incident cases); and prostate cancer (1.3 million incident cases). The most common causes of cancer deaths and DALYs for men were TBL cancer (1.3 million deaths and 28.4 million DALYs), liver cancer (572000 deaths and 15.2 million DALYs), and stomach cancer (542000 deaths and 12.2 million DALYs). For women in 2017, the most common incident cancers were NMSC (3.3 million incident cases), breast cancer (1.9 million incident cases), and colorectal cancer (819000 incident cases). The leading causes of cancer deaths and DALYs for women were breast cancer (601000 deaths and 17.4 million DALYs), TBL cancer (596000 deaths and 12.6 million DALYs), and colorectal cancer (414000 deaths and 8.3 million DALYs). Conclusions and Relevance: The national epidemiological profiles of cancer burden in the GBD study show large heterogeneities, which are a reflection of different exposures to risk factors, economic settings, lifestyles, and access to care and screening. The GBD study can be used by policy makers and other stakeholders to develop and improve national and local cancer control in order to achieve the global targets and improve equity in cancer care. © 2019 American Medical Association. All rights reserved.Peer reviewe

Effect of Intermediate-Dose vs Standard-Dose Prophylactic Anticoagulation on Thrombotic Events, Extracorporeal Membrane Oxygenation Treatment, or Mortality among Patients with COVID-19 Admitted to the Intensive Care Unit: The INSPIRATION Randomized Clinical Trial

Importance: Thrombotic events are commonly reported in critically ill patients with COVID-19. Limited data exist to guide the intensity of antithrombotic prophylaxis. Objective: To evaluate the effects of intermediate-dose vs standard-dose prophylactic anticoagulation among patients with COVID-19 admitted to the intensive care unit (ICU). Design, Setting, and Participants: Multicenter randomized trial with a 2 � 2 factorial design performed in 10 academic centers in Iran comparing intermediate-dose vs standard-dose prophylactic anticoagulation (first hypothesis) and statin therapy vs matching placebo (second hypothesis; not reported in this article) among adult patients admitted to the ICU with COVID-19. Patients were recruited between July 29, 2020, and November 19, 2020. The final follow-up date for the 30-day primary outcome was December 19, 2020. Interventions: Intermediate-dose (enoxaparin, 1 mg/kg daily) (n = 276) vs standard prophylactic anticoagulation (enoxaparin, 40 mg daily) (n = 286), with modification according to body weight and creatinine clearance. The assigned treatments were planned to be continued until completion of 30-day follow-up. Main Outcomes and Measures: The primary efficacy outcome was a composite of venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days, assessed in randomized patients who met the eligibility criteria and received at least 1 dose of the assigned treatment. Prespecified safety outcomes included major bleeding according to the Bleeding Academic Research Consortium (type 3 or 5 definition), powered for noninferiority (a noninferiority margin of 1.8 based on odds ratio), and severe thrombocytopenia (platelet count &lt;20 �103/µL). All outcomes were blindly adjudicated. Results: Among 600 randomized patients, 562 (93.7) were included in the primary analysis (median interquartile range age, 62 50-71 years; 237 42.2% women). The primary efficacy outcome occurred in 126 patients (45.7%) in the intermediate-dose group and 126 patients (44.1%) in the standard-dose prophylaxis group (absolute risk difference, 1.5% 95% CI,-6.6% to 9.8%; odds ratio, 1.06 95% CI, 0.76-1.48; P =.70). Major bleeding occurred in 7 patients (2.5%) in the intermediate-dose group and 4 patients (1.4%) in the standard-dose prophylaxis group (risk difference, 1.1% 1-sided 97.5% CI,-� to 3.4%; odds ratio, 1.83 1-sided 97.5% CI, 0.00-5.93), not meeting the noninferiority criteria (P for noninferiority &gt;.99). Severe thrombocytopenia occurred only in patients assigned to the intermediate-dose group (6 vs 0 patients; risk difference, 2.2% 95% CI, 0.4%-3.8%; P =.01). Conclusions and Relevance: Among patients admitted to the ICU with COVID-19, intermediate-dose prophylactic anticoagulation, compared with standard-dose prophylactic anticoagulation, did not result in a significant difference in the primary outcome of a composite of adjudicated venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days. These results do not support the routine empirical use of intermediate-dose prophylactic anticoagulation in unselected patients admitted to the ICU with COVID-19. Trial Registration: ClinicalTrials.gov Identifier: NCT04486508. © 2021 American Medical Association. All rights reserved

Disk sekilli eşmerkezli kapasitif mikroüretilmis ultrasonik cevirgeçlerin tasarımı ve mikroüretimi.

In this thesis, a novel concentric annular CMUT design has been fully designed. All design parameters are determined based on the analytical expressions based on CMUT theory. Each CMUT design consists of 4 concentric disc-shaped elements, having equal membrane areas. Each element features hexagonal CMUT cells having side lengths of 50 μm up to 80 μm. The CMUT design features fully-metallized membranes for robust operation. The novel CMUT design presented in this thesis is a state-of-the-art design based on microfabrication using direct wafer bonding technology. A complete microfabrication process flow has been developed for the realization of the CMUT design. Diamond coating on the silicon wafer has been characterized in terms of residual stress via Raman Spectroscopy measurements, and viability as a membrane material has been shown. . These measurements result in stresses between 385 compressive stresses up to 364 tensile stress regardless of the type of diamond and underlying silicon or silicon dioxide layer. An interlayer of PECVD-SiO2 is used on the diamond layer. Rapid thermal annealing (RTA) is used to improve the quality of the oxide layer, which is characterized thoroughly using a V-VASE ellipsometer. A surface activation for direct wafer bonding is developed based on a combination of UV/Ozone treatment followed by O2-plasma-activation using RIE. A successful bonding is achieved on two flat wafer surfaces. Due to lack of some essential cleanroom capabilities, a fully functional prototype could not be realized in our work. However, it is straightforward to microfabricate the CMUT based on the outcome of this thesis in the presence of a cleanroom having the essential equipment and setup.M.S. - Master of Scienc

ORGANİK IŞIK YAYAN DİYOTLAR İÇİN ŞEFFAF GRAFEN ANOTLARI

This thesis presents a novel method for fabrication of OLEDs on a specific flexible PET substrate with graphene anodes, demonstrating low sheet resistance, high work function, and an extremely high luminance. Firstly, a single-layer graphene growth process with chemical vapor deposition (CVD) method is optimized. Flexible anodes are then fabricated by stacking 7-layers of graphene films and doped with nitric acid to reduce the sheet resistance. Modified few layer graphene anodes by 29 Ω/□ sheet resistance and 84% transparency are used to fabricate OLEDs with a new family of thermally activated delayed fluorescence (TADF) materials. Observation of TADF in conjugated systems redefined the molecular design approach to realize highly efficient OLEDs in the early 2010s. Enabling effective reverse intersystem crossing (RISC) by minimizing the difference between singlet and triplet excited state energies (ΔEST) has been proven to be a widely applicable and fruitful approach, which resulted in the unproduction of numerous OLED devices with remarkable external quantum efficiencies (EQE). Here, a new series of TADF materials (SeTADFs) with heavy-atom selenium is used as emitters in OLED structure. One of these materials, SeDF-B, resulted in pure blue emission with EQEs approaching 26%. Additionally, flexible graphene-based electrodes were developed for OLEDs vi and revealed similar performance with indium tin oxide (ITO) on glass in most cases while, remarkably, suppressing ITO/Glass in pure blue OLED devices. These devices highlight the first-ever TADF based OLEDs that utilize graphene-based anodes in the literature.Mevcut çalışma düşük levha direnci, yüksek iş fonksiyonu ve yüksek parlaklık özellikleri sergileyerek bükülebilir bir alt taş üzerinde OLED üretiminde yeni bir metot ortaya koymaktadır. İlk olarak, kimyasal buhar biriktirme (CVD) metodu ile tek katman grafen büyüme süreci optimize edilmiştir. Daha sonra, esnek anotlar yedi kat grafen üst üste birleştirilerek ve levha direncini azaltmak için nitrik asit ile katkılanılarak üretilmiştir. 29 Ω/□ levha direnci ve 84% şeffaflığa sahip modifiye edilmiş birkaç katmanlı grafen anotları TADF OLED’lerin üretiminde kullanılmıştır. Konjuge sistemlerdeki TADF gözlemi, 2010’ların başında yüksek verimliliğe sahip OLED’lerin moleküler dizaynına ilişkin yaklaşımı yeniden tanımlamıştır. Tekli ve üçlü uyarılmış hâl enerjileri (ΔEST) arasındaki farkı minimize ederek efektif RISC için imkan sağlamaktadır ve olağanüstü yüksek EQE özelliğine sahip çeşitli OLED cihazların üretimiyle sonuçlanan geniş çapta uygulanabilir ve verimli bir yaklaşım olarak kanıtlamıştır. Burada ağır-atom selenyumlu yeni bir TADF malzemeler serisi OLED yapısında ışık yayıcı olarak kullanılmıştır. Söz konusu malzemelerden biri olan SeDF-B 26%’ya yaklaşan EQE değerinde saf mavi ışık yaymıştır. Buna ek olarak, OLED için esnek grafen bazlı elektrotlar geliştirilmiş ve bu elektrotlar çoğu zaman cam üzerindeki ITO’lara benzer performans göstermiştir, dahası saf mavi viii OLED’lerdeki ITO/Cam elektrodunu belirgin bir şekilde geçmiştir. Bu cihazlar literatürde ilk grafen bazlı TADF OLED’ler olarak yer almaktadır.Ph.D. - Doctoral ProgramTUBİTAK 115F60

Relationship Comparisons on Instagram

The aim of this study was to investigate whether making comparisons to the relationship posts of known and unknown others (celebrities/influencers) on Instagram is associated with relationship quality (satisfaction, investment, commitment and quality of alternatives). Characteristics such as gender and romantic attachment—people’s comfort with closeness and independence— were also investigated to analyze whether they are associated with relationship comparisons on Instagram. Past research states that people are intrinsically motivated to compare to others and that comparisons are common in relationships. Specifically, people may make upward (i.e., contrasting one’s relationship with a superior relationship) or downward comparisons (i.e., contrasting one’s relationship with an inferior relationship) and this is associated with different effects on relationship quality. Instagram is a popular social media platform which allows for widespread access to other people’s lives and relationships, providing increased opportunities for comparisons. As posts on Instagram are often idealized versions of people’s lives, the present study explored how users evaluate their own relationships when making online comparisons