A plea for extension of the official nomenclature of the microscopic structure of human tissues and organs, the Terminologia Histologica

Background: At first sight, the issue of terminology in morphological sciences may seem as “closed and changeless chapter”, as many of the structures within the human body have been known for centuries. However, the exact opposite is true. Terminologia Histologica: International Terms for Human Cytology and Histology published under the Federative International Programme on Anatomical Terminology in 2008 is a new standard in human cell and tissue terminology. The list of items in the first and still valid official nomenclature of cellular and tissue structures, the Terminologia Histologica (TH), is the best and most extensive of all the histological nomenclatures ever issued. Materials and methods: The aim of this article is a systematic and in-depth analysis of the current internationally accepted nomenclature TH, with focus on important histological structures which are missing in this first edition. Some should be incorporated just for the sake of completeness and consistence, others are purely absent terms for individual structures or some are recently described new tissue structures. Results: We also discuss about a question, how to deal with the issue of eponyms. Eponyms reflect medicine’s rich and colourful history. Although they have not been considered official terms in the anatomical nomenclature since 1955, they are still widely used in clinical practice. Conclusions: We hope that this opinion article will develop a wide scientific discussion before the publication of the second edition, so perhaps the mentioned minor flaws will be corrected, so the new edition of the TH will become truly an internationally accepted communication tool for all histologists, histopathologists and anatomists

Antiferrodistortive phase transition in EuTiO3

X-ray diffraction, dynamical mechanical analysis and infrared reflectivity studies revealed an antiferrodistortive phase transition in EuTiO3 ceramics. Near 300K the perovskite structure changes from cubic Pm-3m to tetragonal I4/mcm due to antiphase tilting of oxygen octahedra along the c axis (a0a0c- in Glazer notation). The phase transition is analogous to SrTiO3. However, some ceramics as well as single crystals of EuTiO3 show different infrared reflectivity spectra bringing evidence of a different crystal structure. In such samples electron diffraction revealed an incommensurate tetragonal structure with modulation wavevector q ~ 0.38 a*. Extra phonons in samples with modulated structure are activated in the IR spectra due to folding of the Brillouin zone. We propose that defects like Eu3+ and oxygen vacancies strongly influence the temperature of the phase transition to antiferrodistortive phase as well as the tendency to incommensurate modulation in EuTiO3.Comment: PRB, in pres

Synthesis of centrifugally spun polyacrylonitrile-carbon fibers

This work demonstrates the carbonization of centrifugally spun polyacrylonitrile (PAN) fibers. Initially, the optimal centrifugal spinning conditions for producing homogeneous PAN fibers were identified. Second, the process continued by stabilization and carbonization of PAN to ensure a pure carbonaceous fiber material by eliminating all non-carbonaceous matter. The spun PAN fibers were stabilized at 240 °C in air at a heating rate of 1 °C/min, then carbonized between 600 and 1200 °C in argon at 5 °C/min. After carbonization, the fibers were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Raman spectroscopy (RS). The SEM results showed that by increasing the carbonization temperature, the prolonged elimination of other functional groups resulted in the formation of thinner carbon fibers. FTIR spectra of PAN fibers revealed that the peaks associated with C≡N bonds were substantially reduced and C–H bonds were eliminated in the fibers during the stabilization. These reductions are attributed to the cyclization of nitrile groups and the stabilizing process, and increasing carbonization temperatures resulted in flatter FTIR curves, supporting the findings. According to XRD, the structure of PAN was disturbed, as desired, and carbonization led to the formation of broad bumps resulting from amorphous carbon. Raman investigations found that increasing the carbonization temperature from 600 to 1200 °C resulted in no significant R values, suggesting that all fibers had no structural ordering. The study results could be used in many other areas, such as the fabrication of electrodes, supporting catalytic reactions, filter media, and energy