it has been proved that sphericity testing for digraphs is an np-complete problem. here, we investigate sphericity of 3-connected single source digraphs. we provide a new combinatorial characterization of sphericity and give a linear time algorithm for sphericity testing. our algorithm tests whether a 3-connected single source digraph with $n$ vertices is spherical in $o(n)$ time.

The molecular analysis of formalin-fixed and paraffin-embedded tissues has application in both investigative studies and clinical practice (1). It is now possible to analyze gene expression in formalin-fixed and paraffin-embedded tissues by in situ reverse transcriptase-polymerase chain reaction (in situ RT-PCR) (2). Degradation of RNA, however, can occur at various stages of tissue preparation...

Molecular diagnostics in personalized medicine increasingly relies on the combination of a variety of analytical technologies to characterize individual diseases and to select patients for targeted therapies. The gold standard for tissue-based diagnostics is fixation in formalin and embedding in paraffin, which results in excellent preservation of morphology but negatively impacts on a variety ...

Autophagy assures cellular homeostasis, and gains increasing importance in cancer, where it impacts on carcinogenesis, propagation of the malignant phenotype and development of resistance. To date, its tissue-based analysis by immunohistochemistry remains poorly standardized. Here we show the feasibility of specifically and reliably assessing the autophagy markers LC3B and p62 (SQSTM1) in forma...

The purpose of the present study was to investigate the possibility of immunoelectron microscopic observation of endocrine cells in paraffin-embedded tissues. The procedure, which involves reprocessing from sliced tissues and immunohistochemical staining by colloidal-gold immunolabeling of paraffin sections from paraffin blocks, was able to reveal the fine characteristics of secretory granules ...

The pathogenesis of 210Po-induced tumors in the peripheral lung of Syrian golden hamsters has been studied in a serial sacrifice experiment utilizing both plastic (glycol methacrylate) and routine paraffin embedding procedures for lung sections. A rapid progression from hyperplasia of bronchiolar-type cells that appear in the alveolar region to malignant tumors was documented. Tumors began appe...

A protocol was developed to detect bacteria inhabiting microarthropods by means of small-subunit rRNA-targeted fluorescence in situ hybridization and microscopy. The protocol is based on cryosections of whole specimens. In contrast to more commonly applied paraffin-embedding techniques, the protocol is quicker and reduces the number of manipulations which might damage the microscopic material. ...

We developed a modified paraffin-embedding histologic technique for processing metallic coil-bearing aneurysm tissues. This modified technique was successfully employed for processing platinum coil-bearing tissue for 30 rabbit aneurysms and 6 swine aneurysms. This technique for sectioning coil-bearing aneurysms resulted in little or no tissue distortion and permitted good preservation of morpho...