Thermal transport across wrinkles in few-layer graphene stacks

Wrinkles significantly influence the physical properties of layered 2D materials, including graphene. In this work, we examined thermal transport across wrinkles in vertical assemblies of few-layer graphene crystallites using the Raman optothermal technique supported by finite-element analysis simulations. A high density of randomly oriented uniaxial wrinkles were frequently observed in the few-layer graphene stacks which were grown by chemical vapor deposition and transferred on Si/SiO₂ substrates. The thermal conductivity of unwrinkled regions was measured to be, κ ∼ 165 W m^-1 K^-1. Measurements at the wrinkle sites revealed local enhancement of thermal conductivity, with κ ∼ 225 W m^-1 K^-1. Furthermore, the total interface conductance of wrinkled regions decreased by more than an order of magnitude compared to that of the unwrinkled regions. The physical origin of these observations is discussed based on wrinkle mediated decoupling of the stacked crystallites and partial suspension of the film. Wrinkles are ubiquitous in layered 2D materials, and our work demonstrates their strong influence on thermal transport.

Regioselective synthesis of 7-acetyl-11c-methyl-4b,5,7,11c-tetrahydro[1]benzofuro[2′,3′:4,5]thiopyrano[2,3-b]indoles by sequential Claisen rearrangement of 2-(4′-aryloxybut-2′-ynylthio)-1-acetylindoles

Hitherto unreported indole-annulated pentacyclic heterocycles containing oxygen, nitrogen and sulfur have been synthesised by thermal Claisen rearrangement followed by Lewis acid catalysed Claisen rearrangement. 9-Acetyl-4-aryloxymethyl-2,9-dihydrothiopyrano[2,3- b]indoles are regioselectively synthesised in 80–85 % yield by thermal rearrangement of 2-(4′-aryloxybut-2′-ynylthio)-1-acetylindoles. A second, Lewis acid catalysed, rearrangement gave 7-acetyl-11c-methyl-4b,5,7,11c-tetrahydro[1]benzofuro[2′,3′: 4,5]thiopyrano[2,3- b]indoles in yields of 85–90 %. The thermal Claisen rearrangement in refluxing N,N-diethylaniline for 3 h gave the same products in lower yield (50–54 %).

Regioselective synthesis of thieno[2,3-b]indoles by tandem cyclisation involving sequential sigmatropic rearrangements

Thieno[2,3- b]indoles can be synthesised in 70–80 % yield by the sulfoxide rearrangement of 2-(4′-aryloxybut-2′-ynylthio)-1-methylindoles. The substrates are prepared by phase-transfer-catalysed alkylation of 1-methylindoline-2-thione with 1-aryloxy-4-chlorobut-2-ynes.

Copper(I) Iodide Supported Synthesis of Coumarin- and Quinolone-Annulated 2-Aminothiazoles

An efficient and convenient method for the synthesis of coumarin- and quinolone-annulated 2-aminothiazoles is reported. The fused ring 2-aminothiazoles were synthesized from substituted coumarin/quinoline and phenylisothiocyanates in the presence of CuI, DABCO, and 1,10-phenanthroline. Both the rings in coumarin moiety supported the annulation by this method.

Tuberculosis in the pituitary fossa: a common pathology in an uncommon site

Tuberculosis (TB) is an important cause of mortality and morbidity across the world. In 2–5% of all cases of systemic TB, the C is affected, with lesions reported in the meninges, cortex and ventricles. Intrasellar tuberculomas, however, are extremely rare. We report the interesting case of a young female patient who presented with secondary hypothyroidism and hyperprolactinaemia. She was treated successfully for pituitary TB. We also highlight and discuss some interesting (and hitherto unreported) endocrine issues. Radiological and histological features and treatment of pituitary TB are discussed using this case as an example.

Analysis of petroleum contaminated soils by spectral modeling and pure response profile recovery of n-hexane

This pilot study compared penalized spline regression (PSR) and random forest (RF) regression using visible and near-infrared diffuse reflectance spectroscopy (VisNIR DRS) derived spectra of 164 petroleum contaminated soils after two different spectral pretreatments [first derivative (FD) and standard normal variate (SNV) followed by detrending] for rapid quantification of soil petroleum contamination. Additionally, a new analytical approach was proposed for the recovery of the pure spectral and concentration profiles of n-hexane present in the unresolved mixture of petroleum contaminated soils using multivariate curve resolution alternating least squares (MCR-ALS). The PSR model using FD spectra (r(2) = 0.87, RMSE = 0.580 log10 mg kg(-1), and residual prediction deviation = 2.78) outperformed all other models tested. Quantitative results obtained by MCR-ALS for n-hexane in presence of interferences (r(2) = 0.65 and RMSE 0.261 log10 mg kg(-1)) were comparable to those obtained using FD (PSR) model. Furthermore, MCR ALS was able to recover pure spectra of n-hexane.

Rapid estimation of compost enzymatic activity by spectral analysis method combined with machine learning

The aim of this study was to investigate the feasibility of using visible near-infrared (VisNIR) diffuse reflectance spectroscopy (DRS) as an easy, inexpensive, and rapid method to predict compost enzymatic activity, which traditionally measured by fluorescein diacetate hydrolysis (FDA-HR) assay. Compost samples representative of five different compost facilities were scanned by DRS, and the raw reflectance spectra were preprocessed using seven spectral transformations for predicting compost FDA-HR with six multivariate algorithms. Although principal component analysis for all spectral pretreatments satisfactorily identified the clusters by compost types, it could not separate different FDA contents. Furthermore, the artificial neural network multilayer perceptron (residual prediction deviation=3.2, validation r(2)=0.91 and RMSE=13.38 μg g(-1) h(-1)) outperformed other multivariate models to capture the highly non-linear relationships between compost enzymatic activity and VisNIR reflectance spectra after Savitzky-Golay first derivative pretreatment. This work demonstrates the efficiency of VisNIR DRS for predicting compost enzymatic as well as microbial activity.

Retrieval of kidney tissue for light microscopy from frozen tissue processed for immunofluorescence: A simple procedure to avoid repeat kidney biopsies

We highlight a method that is helpful in situations where the tissue sent for LM is inadequate whereas the tissue sent for IF showed glomeruli useful for interpretation. We utilized the leftover frozen tissue after the sections for IF were taken. This tissue was post-fixed in formalin for the purpose of light microscopic diagnosis. The glomerular pathology could be commented upon with a fair degree of accuracy and a repeat biopsy was avoided in 74.7% of the cases. However, the tubules showed marked fixation artefact and tubular pathology was distorted. This procedure can help to reach a correct diagnosis in large percentage of cases otherwise labeled as inadequate biopsy and hence, save the patient from the trauma of a repeat biopsy.

Cytodiagnosis of alveolar soft part sarcoma: Report of two cases with special emphasis on the first orbital lesion diagnosed by aspiration cytology

Alveolar soft part sarcoma (ASPS) is a rare neoplasm of uncertain cell of origin. Known to occur in adolescents and young adults, this tumor usually involves the muscles and deep soft tissues of the extremities and trunk. Orbital localization is rare and not yet subjected to cytological assessment, as per our literature search. We present here two cases of ASPS diagnosed by aspiration cytology, one in the orbit and the other in the lower extremity. The cells displayed abundant clear to finely vacuolated cytoplasm, often with disrupted margins and flowing of the cytoplasmic material; prominent nucleoli and scattered bare nuclei were also seen in the background. Two close cytological differential diagnoses include metastatic renal cell carcinoma and paraganglioma. Intracytoplasmic periodic acid schiff (PAS) positive, diastase-resistant, needle-shaped crystals and corresponding rhomboid crystals with regular lattice pattern on ultrastructure are the hallmarks of this neoplasm. Due to its slowly progressive clinical course and poor outcome, preoperative diagnosis of ASPS through fine-needle aspiration cytology may be essential for deciding therapy, especially in rare and difficult locations like orbit, where adjuvant radiation may not be possible.