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The earliest evidence for land plants comes from dispersed cryptospores from the Ordovician, which dominated assemblages for 60 million years. Direct evidence of their parent plants comes from minute fossils in Welsh Borderland Upper Silurian to Lower Devonian rocks. We recognize a group that had forking, striated axes with rare stomata terminating in valvate sporangia containing permanent cryptospores, but their anatomy was unknown especially regarding conducting tissues. Charcoalified fossils extracted from the rock using HF were selected from macerates and observed using scanning electron microscopy. Promising examples were split for further examination and compared with electron micrographs of the anatomy of extant bryophytes. Fertile fossil axes possess central elongate cells with thick walls bearing globules, occasional strands and plasmodesmata-sized pores. The anatomy of these cells best matches desiccation-tolerant food-conducting cells (leptoids) of bryophytes. Together with thick-walled epidermal cells and extremely small size, these features suggest that these plants were poikilohydric. Our new data on conducting cells confirms a combination of characters that distinguish the permanent cryptospore-producers from bryophytes and tracheophytes. We therefore propose the erection of a new group, here named the Eophytidae (eophytes).

Summary Extension of the internode below the point of insertion of the flag leaf of Lolium temulentum L. takes place in the lower 10 to 15 mm. Extension of the long epidermal cells also takes place in this region. However, fibre cells show little extension in the lower 10 mm and maximum extension occurs at about 30 mm above the node. Thus, there is extension of fibre cells within that portion of the internode which has ceased extension and is bounded by an epidermis, the cells of which have also ceased elongation. This suggests the occurrence of intrusive growth of the fibres and evidence for this is shown from the measurement of macerated fibres and from electron micrographs. The walls of fibre cells measured in internodes of different lengths and ages thicken only very slightly in the lower 30 mm and most cell wall thickening occurs between 45 and 90 mm above the node. Thus most cell wall thickening occurs after the fibre cells have ceased to elongate.

Objective To examine the effect of Ureaplasma parvum (U. parvum) infection on mouse sperm motility, structure, and fertilizing ability and on embryo development. Design In vitro model of the effects of U. parvum serovar 3 infection on mouse sperm. Setting Basic research laboratory. Intervention(s) None. Animals Mice. Main Outcome Measure(s) Mouse sperm motility was examined using the swim-up method, and their motility parameters were analyzed using the sperm motility analysis system. Localization and invasion of U. parvum were observed with fluorescence, confocal, and scanning electron microscopy. After in vitro fertilization with U. parvum–infected sperm, the quality of the fertilized egg and embryo development were assessed. Result(s) U. parvum was attached and internalized into mouse sperms and localized mainly at the sperm head and midpiece. U. parvum–infected mouse sperms exhibited decreased motility in a dose- and duration-dependent manner. Electron micrographs revealed that U. parvum infection induced the aggregation and morphological destruction of mouse sperm. Infected mouse sperm transported U. parvum into the fertilized egg with reduced fertilization rates, and infected embryo development was impaired. Conclusion(s) U. parvum infection caused deterioration of the mouse sperm quality and its functions, which affected the fertilization rate and embryo development.

Multivalent intrinsically disordered protein (IDP) complexes are prevalent in biology and control diverse cellular functions, including tuning levels of transcription, coordinating cell-signaling events, and regulating the assembly and disassembly of complex macromolecular architectures. These systems pose a significant challenge to structural investigation, due to the continuum dynamics imparted by the IDP and compositional heterogeneity resulting from characteristic low-affinity interactions. Traditional single-particle electron microscopy (EM) is a powerful tool for visualizing IDP complexes. However, the IDPs themselves are typically “invisible” by EM, undermining methods of image analysis and structural interpretation. To overcome these challenges, we developed a pipeline for automated analysis of common ‘beads-on-a-string’ type of assemblies, composed of IDPs bound at multivalent sites to the ubiquitous ~20 kDa cross-linking hub protein LC8. This approach quantifies conformational and compositional heterogeneity on a single-particle basis, and statistically corrects spurious observations arising from random proximity of bound and unbound LC8. After careful validation of the methodology, the approach was applied to the nuclear pore IDP Nup159 and the transcription factor ASCIZ. The analysis unveiled significant compositional and conformational diversity in both systems that could not be obtained from traditional single particle EM class-averaging strategies, and shed new light on how these architectural properties contribute to their physiological roles in supramolecular assembly and transcriptional regulation. Ultimately, we expect that this approach may be adopted to many other intrinsically disordered systems that have evaded traditional methods of structural characterization.Significance StatementIntrinsically disordered proteins (IDPs) or protein regions (IDRs) represent >30% of the human proteome, but mechanistically remain some of the most poorly understood classes of proteins in biology. This dearth in understanding stems from these very same intrinsic and dynamic properties, which make them difficult targets for quantitative and structural characterization. Here, we present an automated approach for extracting quantitative descriptions of conformational and compositional heterogeneity present in a common ‘beads-on-a-string’ type of multivalent IDP system from single-particle images in electron micrographs. This promising approach may be adopted to many other intrinsically disordered systems that have evaded traditional ensemble methods of characterization.

Whole-slide imaging and virtual microscopy are useful tools implemented in the routine pathology workflow in the last 10 years, allowing primary diagnosis or second-opinions (telepathology) and demonstrating a substantial role in multidisciplinary meetings and education. The regulatory approval of this technology led to the progressive digitalization of routine pathological practice. Previous experiences on renal biopsies stressed the need to create integrate networks to share cases for diagnostic and research purposes. In the current paper, we described a virtual lab studying the routine renal biopsies that have been collected from 14 different Italian Nephrology centers between January 2014 and December 2019. For each case, light microscopy (LM) and immunofluorescence (IF) have been processed, analysed and scanned. Additional pictures (eg. electron micrographs) along with the final encrypted report were uploaded on the web-based platform. The number and type of specimens processed for every technique, the provisional and final diagnosis, and the turnaround-time (TAT) have been recorded. Among 826 cases, 4.5% were second opinion biopsies and only 4% were suboptimal/inadequate for the diagnosis. Transmission electron microscopy (TEM) has been performed on 41% of cases, in 22% changing the final diagnosis, in the remaining 78% contributed to the better definition of the disease. For light microscopy and IF the median TAT was of 2 working days, with only 8.6% with a TAT longer than 5 days. For TEM, the average TAT was 26 days (IQR 6–64). In summary, we systematically reviewed the 6-years long nephropathological experience of an Italian renal pathology service, where digital pathology is a definitive standard of care for the routine diagnosis of glomerulonephritides.

The ultrastructural effects of prolonged normothermic and cold ischemia on the cerebral cortex of the adult rat were investigated. Complete cerebral ischemia was produced by cardiac arrest and the animals' temperature was maintained at 37°C for periods ranging from 0 to 81 hours before electron microscopy preparation. Electron micrographs of cold cerebral ischemia were generated after stabilizing the rat's temperature at 0°C after cardiac arrest for periods ranging from 0 hours to 6 months. A qualitative examination of the electron micrographs shows structural signatures of energy depletion such as vessel leaking and chromatin clumping after 1 hour at 37°C and after 24 hours at 0°C, followed by synapse degradation after 6 hours at 37°C and 1 week at 0°C. Evidence of advanced necrosis was observed after 36 hours at 37°C and 2 months at 0°C. A deep learning algorithm was introduced that demonstrates the temperature dependence of ischemia-induced ultrastructural changes and that can also successfully distinguish between early ischemic changes and advanced necrosis.

This review is the second part of a series which presents the state of the art in stratum corneum (SC) lipid matrix (LM) research in depth. In this part, the various hypothetical models which were developed to describe the structure and function of the SC LM as the skin’s barrier will be discussed. New as well as a cumulative assortment of older results which change the view on the different models are considered to conclude how well the different models are holding up today. As a final conclusion, a model, factoring in as much of the known data as possible, is concluded, unifying the varying different models into one which can be developed further, as new results are found in the future. So far, the model is described with a single crystalline or gel-like phase with a certain amount of nanocrystallites of concentrated ceramides (CERs) and free fatty acids and more fluid nanodomains caused by a fluidizing effect of the cholesterol. These domains are dynamically resolved and reformed and do not impair the barrier function. The chain conformation is not completely clear yet; however, an equilibrium of fully extended and hairpin-folded CERs with ratios depending on the properties of each individual CER species is proposed as most likely. An overlapping middle layer as described for the tri-layer model in part I of this series would be present for both conformations. The macroscopic broad-narrow-broad layering, observed in electron micrographs, is explained by an external templating by the lipid envelope, and an internal templating by short and long lipid chains each preferentially show a homophilic association, forming thicker and thinner bilayers, respectively. The degree of influence of the very long ω-hydroxy-CERs is discussed as well.

The ability to visualize cell and tissue morphology at a high magnification using scanning electron microscopy (SEM) has revolutionized plant sciences research. In plant–insect interactions studies, SEM-based imaging has been of immense assistance to understand plant surface morphology including trichomes [plant hairs; physical defense structures against herbivores], spines, waxes, and insect morphological characteristics such as mouth parts, antennae, and legs, that they interact with. While SEM provides finer details of samples, and the imaging process is simpler now with advanced image acquisition and processing, sample preparation methodology has lagged. The need to undergo elaborate sample preparation with cryogenic freezing, multiple alcohol washes, and sputter coating makes SEM imaging expensive, time consuming, and warrants skilled professionals, making it inaccessible to majority of scientists. Here, using a desktop version of SEM (SNE- 4500 Plus Tabletop), we show that the “plug and play” method can efficiently produce SEM images with sufficient details for most morphological studies in plant–insect interactions. We used leaf trichomes of Solanum genus as our primary model, and oviposition by tobacco hornworm (Manduca sexta; Lepidoptera: Sphingidae) and fall armyworm (Spodoptera frugiperda; Lepidoptera: Noctuidae), and leaf surface wax imaging as additional examples to show the effectiveness of this instrument and present a detailed methodology to produce the best results with this instrument. While traditional sample preparation can still produce better resolved images with less distortion, we show that even at a higher magnification, the desktop SEM can deliver quality images. Overall, this study provides detailed methodology with a simpler “no sample preparation” technique for scanning fresh biological samples without the use of any additional chemicals and machinery.

SummaryMitochondrial dynamics (fission, fusion, and the formation of nanotunnels) and morphology are very sensitive to the cellular environment. Mitochondria may be adversely affected by oxidative stress, changes in calcium levels, and hypoxia. Investigating the precise relationship between organelle structure and function requires methods that can adequately preserve mitochondria while providing accurate, quantitative measurements of morphological attributes. Here, we demonstrate a practical approach for preserving and measuring fine structural changes using two-dimensional, high-resolution electron micrographs. This approach is further applicable for three-dimensional volume renderings, obtained using serial block-face and focused ion beam-scanning electron microscopy, highlighting the specific advantages of these techniques. Additionally, this study defines a set of quantifiable metrics that can be applied to measure mitochondrial architecture and other organellar structures. Finally, we validated specimen preparation methods that avoid the introduction of morphological artifacts that may interfere with mitochondrial appearance and do not require whole-animal perfusion.

Goal: To develop a micron-scale device that can operate as an MRI-based reporter for the presence of SARS-CoV-2 virus. Methods: Iron rod microdevices were constructed via template-guided synthesis and suspended in phosphate buffered saline (PBS). Heat-inactivated SARS-CoV-2 viruses were added to the samples and imaged with low-field MRI. Results: MRI of microdevices and viruses showed decreased signal intensity at low concentrations of viruses that recovered at higher concentrations. Electron micrographs suggest that reduced MRI intensity may be due to concentration-dependent shielding of water protons from local magnetic inhomogeneities caused by the iron microdevices. Conclusions: The preliminary results presented in this letter provide justification for further studies exploring the potential diagnostic role of magnetic microdevices in assessing the presence and concentration of SARS-CoV-2 viruses.

Metal–organic frameworks (MOFs) based oxygen-evolution reaction (OER) catalyst is an emerging class of highly porous materials that have become increasingly attractive to develop a highly active an...

The data presented in this article are related to the research paper entitled “Correlation of Spectral Domain Optical Coherence Tomography with Histology and Electron Microscopy in the Porcine Retina” (Xie et al., 2018) [2]. This research data highlights our technique for retinal fundus image acquisition during spectral domain optical coherence tomography (SD-OCT) in a large animal model. Low and high magnification electron micrographs are included to demonstrate the ultrastructural features of the porcine retina. Data on horizontal tissue shrinkage during processing of the porcine retina are presented.

Peter B. Rosenthal⇑Division of Physical Biochemistry, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UKe-mail: peter.rosenthal{at}nimr.mrc.ac.uk; peter.rosenthal{at}crick.ac.ukAbstract Elucidation of the structure of biological macromolecules and larger assemblies has been essential to understanding the roles they play in living processes. Methods for three-dimensional structure determination of biological assemblies from images recorded in the electron microscope were therefore a key development. In his paper published in Philosophical Transactions B in 1971, Crowther described new computational procedures applied to the first three-dimensional reconstruction of an icosahedral virus from images of virus particles preserved in negative stain. The method for determining the relative orientation of randomly oriented particles and combining their images for reconstruction exploited the high symmetry of the virus particle. Computational methods for image analysis have since been extended to include biological assemblies without symmetry. Further experimental advances, combined with image analysis, have led to the method of cryomicroscopy, which is now used by structural biologists to study the structure and dynamics of biological machines and assemblies in atomic detail. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society. electron microscopycryomicroscopyvirusreconstructionimage analysisicosahedronFootnotesOne contribution of 18 to a theme issue ‘Celebrating 350 years of Philosophical Transactions: life sciences papers’.The featured article can be viewed at http://dx.doi.org/10.1098/rstb.1971.0054.© 2015 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.

In-resin CLEM of Epon embedded samples can greatly simplify the correlation of fluorescent images with electron micrographs. The usefulness of this technique is limited at present by the low number of fluorescent proteins that resist CLEM processing. Additionally, no study has reported the possibility of two-color in-resin CLEM of Epon embedded cells. In this study, we screened for monomeric green and red fluorescent proteins that resist CLEM processing. We identified mWasabi, CoGFP variant 0, and mCherry2; two green and one red fluorescent proteins as alternatives for in-resin CLEM. We expressed mitochondria-localized mCherry2 and histone H2B tagged with CoGFP variant 0 in cells. Green and red fluorescence was detected in 100 nm-thin sections of the Epon-embedded cells. In the same thin sections, we correlated the fluorescent signals to mitochondria and the nucleus using a scanning electron microscope. Similar results were obtained when endoplasmic reticulum-localized mCherry2 and histone H2B tagged with CoGFP variant 0 were expressed in the cells. Two-color in-resin CLEM of two cytoplasmic organelles, mitochondria and endoplasmic reticulum, was also achieved using mitochondria-localized mCherry2 and endoplasmic reticulum-localized mWasabi. In summary, we report three new fluorescent protein-alternatives suitable for in-resin CLEM of Epon-embedded samples, and achieved Epon-based two-color in-resin CLEM.

Adrenocortical oncocytomas are rare and mostly nonfunctioning neoplasms. We report the case of a 27-year-old woman diagnosed with an ACTH-independent Cushing’s syndrome due to left adrenal oncocytoma. She underwent laparoscopic adrenalectomy. Histopathological examination revealed an oncocytoma of uncertain malignant potential with a low Ki-67 proliferation index, inhibin A positivity, and chromogranin A negativity. Electron micrographs confirmed adrenal oncocytoma cells, characterized by the presence of a large amount of mitochondria. The postoperative course was uneventful, and the patient experienced a progressive regression of Cushing-related symptoms. Periodical follow-ups with MRI and cortisol dosage are required due to the neoplasm’s uncertain malignant potential. Considerations on the diagnosis, pathology findings, clinical remarks, and interventions are made.

Collaborative studies open doors to breakthroughs otherwise unattainable by any one laboratory alone. Here we describe the initial collaboration between the Griffith and de Lange laboratories that led to thinking about the telomere as a DNA template for homologous recombination, the proposal of telomere looping, and the first electron micrographs of t-loops. This was followed by collaborations that revealed t-loops across eukaryotic phyla. The Griffith and Tomaska/Nosek collaboration revealed circular telomeric DNA (t-circles) derived from the linear mitochondrial chromosomes of nonconventional yeast, which spurred discovery of t-circles in ALT-positive human cells. Collaborative work between the Griffith and McEachern labs demonstrated t-loops and t-circles in a series of yeast species. The de Lange and Zhuang laboratories then applied super-resolution light microscopy to demonstrate a genetic role for TRF2 in loop formation. Recent work from the Griffith laboratory linked telomere transcription with t-loop formation, providing a new model of the t-loop junction. A recent collaboration between the Cesare and Gaus laboratories utilized super-resolution light microscopy to provide details about t-loops as protective elements, followed by the Boulton and Cesare laboratories showing how cell cycle regulation of TRF2 and RTEL enables t-loop opening and reformation to promote telomere replication. Twenty years after the discovery of t-loops, we reflect on the collective history of their research as a case study in collaborative molecular biology.

VAR2CSA is the placental-malaria specific member of the antigenically variant Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family. It is expressed on the surface of Plasmodium falciparum infected host red blood cells and binds to specific chondroitin-4-sulfate (CSA) chains of the placental proteoglycan receptor. The functional ~310 kDa ectodomain of VAR2CSA is a multi-domain protein that requires a minimum 12-mer CSA molecule for specific, high affinity receptor binding. However, how these domains interact to create the receptor binding surface is not known, limiting efforts to exploit its potential as an effective vaccine or drug target. Using small angle X-ray scattering and single particle reconstruction from negative stained electron micrographs of the ectodomain and multidomain constructs, we have determined the structural architecture of VAR2CSA. The relative location of the domains creates two distinct pores that can each accommodate the 12-mer of CSA, suggesting a model for receptor binding. This model has important implications for understanding cytoadherence of IRBCs and potentially provides a starting point for developing novel strategies to prevent and/or treat placental malaria.

Primary ciliary dyskinesia (PCD) is a heterogeneous genetic condition. European and North American diagnostic guidelines recommend transmission electron microscopy (TEM) as one of a combination of tests to confirm a diagnosis. However, there is no definition of what constitutes a defect or consensus on reporting terminology. The aim of this project was to provide an internationally agreed ultrastructural classification for PCD diagnosis by TEM.A consensus guideline was developed by PCD electron microscopy experts representing 18 centres in 14 countries. An initial meeting and discussion were followed by a Delphi consensus process. The agreed guideline was then tested, modified and retested through exchange of samples and electron micrographs between the 18 diagnostic centres.The final guideline a) provides agreed terminology and a definition of Class 1 defects which are diagnostic for PCD; b) identifies Class 2 defects which can indicate a diagnosis of PCD in combination with other supporting evidence; c) describes features which should be included in a ciliary ultrastructure report to assist multidisciplinary diagnosis of PCD; and d) defines adequacy of a diagnostic sample.This tested and externally validated statement provides a clear guideline for the diagnosis of PCD by TEM which can be used to standardise diagnosis internationally. ispartof: EUROPEAN RESPIRATORY JOURNAL vol:55 issue:4 ispartof: location:England status: published

Large multivesicular liposomes (LMVV) remotely loaded with bupivacaine (Bupisome) were previously demonstrated to be a stable, long-acting local anesthetic. We demonstrate that this is not the case for small unilamellar vesicles (SUV) of the same lipid composition also remotely loaded with bupivacaine. We show that the trapped volume in LMVV is 21-fold higher and the drug-to-lipid mole ratio is 10-fold higher than in SUV. Cryo-transmission electron micrographs and differential interference contrast microscopy show that there are no bupivacaine crystals inside LMVV and SUV. The thermotropic characterization studied by DSC demonstrates that the drug interacts with the liposome membrane, which, together with the above results on the drug-to-lipid ratio, explains the small in vitro drug release from the SUV and large (but

Cryo-EM single-particle analysis has proven powerful in determining the structures of rigid macromolecules. However, many protein complexes are flexible and can change conformation and composition as a result of functionally-associated dynamics. Such dynamics are poorly captured by current analysis methods. Here, we present cryoDRGN, an algorithm that for the first time leverages the representation power of deep neural networks to efficiently reconstruct highly heterogeneous complexes and continuous trajectories of protein motion. We apply this tool to two synthetic and three publicly available cryo-EM datasets, and we show that cryoDRGN provides an interpretable representation of structural heterogeneity that can be used to identify discrete states as well as continuous conformational changes. This ability enables cryoDRGN to discover previously overlooked structural states and to visualize molecules in motion.

This is a very special book for two reasons. First, it is a tribute to Professor Sir Peter Hirsch from his students, colleagues and friends. Second, it is a collection of specially written review articles by world-class scientists that take the readers from the origins of modem materials science through to the cutting edge of the subject in the twenty- first century. The book will be a valuable resource for all researchers in materials science, particularly those specialising in electron microscopy and diffraction, and in the mechanical properties of materials. The front and back covers of this book are coloured images of historic electron micrographs depicting the first observation in the world of moving dislocations. The pictures were taken by Mike Whelan, then a research student of Peter Hirsch. The image on the front cover is before some dislocations have moved, and the back cover image is after the movement. See if you can spot the difference! This book had its genesis in a symposium organised by Mike Goringe, John Hutchison and myself to mark the retirement of Peter Hirsch from the Isaac Wolfson Chair of Metallurgy at Oxford. This symposium brought together a large number of Peter's former students and colleagues. Some of the most distinguished of these have now written the chapters in this book. The opening chapter, by Professor Ugo Valdre, provides a fascinating biographical sketch of Peter Hirsch from his early career in Cambridge to his retirement in Oxford. It contains many illuminating insights into the personality of Peter, both as a scientist and as a man. The next two chapters focus on the development of electron microscopy and diffraction. Professor Mike Whelan gives an eye-witness account of the seminal early work of Peter and his colleagues at Cambridge on the first observation of dislocations and their movements, using trans-mission electron microscopy. Professor Archie Howie extends this account to the present day, describing nanometer-scale resolution in scanning electron microscopes and atomic scale resolution in the scanning tunnelling microscope.

Normal human cultured melanocytes were exposed to various glutathione concentrations (0.1, 0.5, 1.0, 5.0, and 10.0 mg/mL) for 72 hours. At the end of the experiment, proliferation, viability, migration, and ultrastructural changes were monitored. Glutathione at the doses of 0.5 to 10.0 mg/mL reduced the viability of melanocytes significantly as compared to the control (P < .05). Glutathione significantly reduced the proliferation of melanocytes at the doses of 0.5 to 10.0 mg/mL as compared to the control (P < .001). Glutathione at 0.5 to 10.0 mg/mL significantly reduced the migration of melanocytes as compared to the control (P < .001). The percentage of mature melanosomes was 53.43% in control and 50.58%, 41.83%, 33.4%, and 8.95% in 0.1, 0.5, 1.0, and 5.0 mg/mL glutathione exposed cells, respectively. This reduction in the number of mature melanosomes was statistically significant as compared to the control. However, no cytotoxic effects were recognized by electron micrographs. These results encourage the potential implementation of glutathione as a skin-lightening agent. However, this study is limited by cell culture and ultrastructural. It should therefore be expanded in the future to include patients with pigmentary disorders.

Science advances 6(43), eabc1370 (1-14) (2020). doi:10.1126/sciadv.abc1370, The serpinopathies are among a diverse set of conformational diseases that involve the aberrant self-association of proteins into ordered aggregates. α$_1$-Antitrypsin deficiency is the archetypal serpinopathy and results from the formation and deposition of mutant forms of α$_1$-antitrypsin as “polymer” chains in liver tissue. No detailed structural analysis has been performed of this material. Moreover, there is little information on the relevance of well-studied artificially induced polymers to these disease-associated molecules. We have isolated polymers from the liver tissue of Z α$_1$-antitrypsin homozygotes (E342K) who have undergone transplantation, labeled them using a Fab fragment, and performed single-particle analysis of negative-stain electron micrographs. The data show structural equivalence between heat-induced and ex vivo polymers and that the intersubunit linkage is best explained by a carboxyl-terminal domain swap between molecules of α$_1$-antitrypsin., Published by Assoc., Washington, DC [u.a.]

We re-examined the database of some 20,000 electron micrographs from the Echigo-1, the 263K-strain or the 22C-H of scrapie-infected hamsters to look for the cytoplasmic clearance. We reevaluated the largest database in the world of photographed dystrophic neurites for the presence of cytoplasmic clearance as shown in transgenic fruit flies transfected with A-42. In several neurites, we found electron-lucent areas not bound by any membranes or only partially bound; thus, they were not autophagic vacuoles as the latter are membrane-bound and contain cargo. Those changes were not observed in every examined neurite and no correlation with any other changes were noticed. In some neurites, which could be traced over several sections, the electron-lucent areas were evident to change size, i.e. to expand.

WOS: 000439435100004 Two new species of the spider family Dysderidae, Harpactea forceps sp. n. and Dysdera furcatus sp. n. are described from the west Black Sea region of Turkey. Detailed morphological descriptions and diagnoses are presented. Photographs and electron micrographs are included. The two new species are compared with closely related species.

To identify the key stages in the amyloid fibril formation we studied the aggregation of amyloidogenic fragments of Aβ peptide, Aβ(16-25), Aβ(31-40), and Aβ(33-42), using the methods of electron microscopy, X-ray analysis, mass spectrometry, and structural modeling. We have found that fragments Aβ(31-40) and Aβ(33-42) form amyloid fibrils in the shape of bundles and ribbons, while fragment Aβ(16-25) forms only nanofilms. We are the first who performed 2D reconstruction of amyloid fibrils by the Markham rotation technique on electron micrographs of negatively stained fragments of Aβ peptide. Combined analysis of the data allows us to speculate that both the fibrils and the films are formed via association of ring-shaped oligomers with the external diameter of about 6 to 7 nm, the internal diameter of 2 to 3 nm, and the height of ∼3 nm. We conclude that such oligomers are the main building blocks in fibrils of any morphology. The interaction of ring oligomers with each other in different ways makes it possible to explain their polymorphism. The new mechanism of polymerization of amyloidogenic proteins and peptides, described here, could stimulate new approaches in the development of future therapeutics for the treatment of amyloid-related diseases.

Herein, we aimed to synthesize an efficient room-temperature gas sensor using biomass-derived graphene nanosheets-Ag2S based hybrid nanostructure by a microwave-assisted hydrothermal method. The electron micrographs of the synthesized Ag2S-GNS nanostructure depicts rice-shaped Ag2S nanoparticles impregnated onto graphene surfaces. Interestingly, the bandgap of Ag2S and Ag2S-GNS based hybrid nanostructures were identified to be 2.04 eV and 1.75 eV, respectively. The Ag2S-GNS based hybrid nanostructure showed better hydrogen sensing efficiency than the pure Ag2S nanoparticles. The maximum response of 45.5 % for 150 ppm exposure of hydrogen gas was obtained for Ag2S-GNS based hybrid nanostructure at room temperature. The sensing response and recovery of Ag2S-GNS hybrid nanostructures towards hydrogen gas were found to be 19 sec and 31 sec, respectively. The high gas sensitivity and fast response time of the hybrid sensor were due to assorted attributes and synergetic effect between Ag2S and GNS hybrids.

Cardiomyocytes are particularly prone to lipofuscin accumulation. In the aging heart, lipofuscin accumulation is augmented. This study examined distribution of lipofuscin and senescent cardiomyocytes and evaluated improvement of lipofuscin accumulation and cardiomyocytic senescence of the aging heart after treatment with rapamycin. The results of Schmorl staining, Sudan black staining and autofluorescence detection showed that there was more lipofuscin in the myocardium of the ventricles especially in the left ventricle. The conductive tissue contained less lipofuscin than the myocardium. In the aged hearts, lipofuscin accumulation and senescent cardiomyocytes were increased, and the level of autophagy was reduced. In double staining of Sudan black B and senescence-associated β-galactosidase, 10%–20% lipofuscin-loaded cardiomyocytes became senescent. All senescent cardiomyocytes contained lipofuscin deposits. After enhancing autophagy with feed of rapamycin for six months, lipofuscin accumulation and senescence of cardiomyocytes were improved in old rats. Colocalization of autophagic structure and lipofuscin as well as electron micrographs showed that some lipofuscin-loaded lysosomes were sequestrated by autophagic structures. This study suggests that rapamycin-enhanced autopahgy is effective for reducing lipofuscinogenesis and promoting degradation of lipofuscin. Therefore, enhancing autophagy is a novel therapy for alleviating lipofuscin accumulation and myocardial senescence.

In this paper, we used Niggli reduced cell theory to determine lattice constants of a micro/nano crystal by using electron diffraction patterns. The Niggli reduced cell method enhanced the accuracy of lattice constant measurement obviously, because the lengths and the angles of lattice vectors of a primitive cell can be measured directly on the electron micrographs instead of a double tilt holder. With the aid of digitized algorithm and least square optimization by using three digitized micrographs, a valid reciprocal Niggli reduced cell number can be obtained. Thus a reciprocal and real Bravais lattices are acquired. The results of three examples, i.e., Mg4Zn7, an unknown phase (Precipitate phase in nickel-base superalloy) and Ba4Ti13O30 showed that the maximum errors are 1.6% for lengths and are 0.3% for angles.

Tilapia skin gelatin (TSG) was studied in a 3-stage process (cooling, annealing, and heating) for pure gelatin gels and in a 4-stage process (acidification, cooling, annealing, and heating) for acid milk gels and cultured yogurt. The aim was to evaluate the use of TSG as a replacement for mammalian gelatin in yogurt. In pure TSG gels, stronger gels with higher melting temperatures were formed with increasing TSG concentrations. Compared with bovine gelatin (BG), which gelled at a concentration of 2.5%, TSG gels had lower gelling (14.1°C) and melting (24°C) temperatures but comparable storage moduli during annealing. In acid milk gels, addition of TSG increased the firmness of the gels with increasing concentration. Gelling and melting points of TSG in milk gels were observed at sufficient concentrations during cooling and heating. Strands and sheets were observed in the electron micrographs of milk gels with 1% TSG and a very dense structure was observed with 2.5% TSG. Yogurt with 0.4% TSG had similar viscosity, consistency, pseudoplasticity, and thixotropy as yogurt containing 0.4% BG; no difference was perceived by sensory panelists according to a triangle test. Addition of 0.4% TSG completely prevented whey separation from the acid milk gel and yogurt. The results suggest that TSG could be a suitable replacement for mammalian gelatin in low-fat stirred yogurt.