About seller
The on-surface synthesis of atomically flat N-doped graphene on oxidized copper is presented. Besides circumventing the almost standard use of metallic substrates for growth, this method allows producing graphene with ∼2.0 at % N in a substitutional configuration directly decoupled from the substrate. Angle-resolved photoemission shows a linear energy-momentum dispersion where the Dirac point lies at the Fermi level. Additionally, the N functional centers can be selectively tailored in sp2 substitutional configuration by making use of a purpose-made molecular precursor dicyanopyrazophenanthroline (C16H6N6).Recently two-dimensional (2D) hybrid organic-inorganic perovskites have attracted a lot of interest as more stable analogues of their three-dimensional counterparts for optoelectronic applications. https://www.selleckchem.com/products/eidd-2801.html However, a thorough understanding of the effect that this reduced dimensionality has on dynamical and structural behavior of individual parts of the perovskite is currently lacking. We have used molecular dynamics simulations to investigate the structure and dynamics of 2D Ruddlesden-Popper perovskite with the general formula BA2MA n-1Pb n I3n+1, where BA is butylammonium, MA is methylammonium, and n is the number of lead-iodide layers. We discuss the dynamic behavior of both the inorganic and the organic part and compare between the different 2D structures. We show that the rigidness of the inorganic layer markedly increases with the number of lead-iodide layers and that low-temperature structural phase changes accompanied by tilting of the octahedra occurs in some but not all structures. Furthermore, the dynamic behavior of the MA ion is significantly affected by the number of inorganic layers, involving changes both in the reorientation times and in the occurrence of specific preferred orientations.Bayesian Additive Regression Trees (BART) is a flexible machine learning algorithm capable of capturing nonlinearities between an outcome and covariates and interactions among covariates. We extend BART to a semiparametric regression framework in which the conditional expectation of an outcome is a function of treatment, its effect modifiers, and confounders. The confounders are allowed to have unspecified functional form, while treatment and effect modifiers that are directly related to the research question are given a linear form. The result is a Bayesian semiparametric linear regression model where the posterior distribution of the parameters of the linear part can be interpreted as in parametric Bayesian regression. This is useful in situations where a subset of the variables are of substantive interest and the others are nuisance variables that we would like to control for. An example of this occurs in causal modeling with the structural mean model (SMM). Under certain causal assumptions, our method can be used as a Bayesian SMM. Our methods are demonstrated with simulation studies and an application to dataset involving adults with HIV/Hepatitis C coinfection who newly initiate antiretroviral therapy. The methods are available in an R package called semibart.Emergency physicians often rely on heuristics to facilitate clinical decisions due to the large volume of patients they see daily. Consequently, they are vulnerable to error and bias. We report the case of a 69-year-old male that presented to the emergency department (ED) with shortness of breath, productive cough, and dyspnea on exertion. One day prior to ED admission, he was diagnosed with bronchitis; however, point-of-care ultrasound (POCUS) in the ED identified acute pulmonary embolism. This case illustrates the potential dangers of anchoring bias and shows the benefits of using point-of-care ultrasound of the lungs and heart to assist in the diagnosis of acute pulmonary embolism.Pyoderma gangrenosum (PG) is a rare noninfectious skin condition which clinical picture can overlap with that of the diabetic foot. Meticulous physical examination along with biopsy and magnetic resonance imaging (MRI) can make the distinction easier, saving the patients from undergoing a debilitating intervention. We report a case of pathologically proven PG in the right ankle region of a 55-year old male with known uncontrolled diabetes mellitus and inflammatory bowel disease. Radiographs revealed increased soft tissue density overlying the lateral melleolus of the right ankle. MRI showed a well-defined soft tissue mass with heterogeneously intrinsically high signal intensity on T1- and on T2-weighted images, and heterogeneous peripheral enhancement on fat-suppressed, contrast-enhanced T1-weighted images. Histologically, diffuse neutrophilic infiltrate throughout the dermis was present without micro-organisms. This is the first report of MRI findings of PG in the ankle. We also summarize the findings of previously reported cases of PG.Blake pouch remnant, also known as Blake pouch cyst or persistent Blake pouch, is a posterior fossa embryologic anomaly that is often seen in isolation with most affected patients being asymptomatic. However, even in isolation, Blake pouch remnant can result in obstructive hydrocephalus requiring early neurosurgical intervention making it an important diagnosis for the fetal radiologist to consider. We present a rare case of a patient with prenatally diagnosed "inferior vermian hypoplasia" on fetal MRI that went on to develop progressive obstructive hydrocephalus in infancy secondary to what was determined to be a Blake pouch remnant.Retroperitoneal fibrosis (RPF) is a relatively rare entity, characterized by chronic inflammation and fibrosis in the retroperitoneal periaortic tissues. Due to this rarity, the diagnosis might be delayed or challenging, especially with atypical presentations of RPF. We report the imaging findings of an incidental finding of active RPF in an asymptomatic 84-year-old male patient. This patient was initially diagnosed with a perirenal hematoma due to an atypical imaging presentation on a routine staging computed tomography scan of the chest and the abdomen to stage a recently discovered prostate cancer. However, due to the persistence of the perirenal lesion, subsequent magnetic resonance imaging of this lesion was conducted, which resulted in the final diagnosis of active RPF. With this case report, we want to address attention to the potential atypical presentation of RPF, which could mimic a perirenal mass and demonstrates the importance of a broad differential diagnosis. Secondly, we want to point out the importance of magnetic resonance imaging in the evaluation of RPF, since it can differentiate between inactive or chronic idiopathic RPF and active idiopathic RPF or malignant RPF.