Micron最新文献

{"title":"Practical considerations for plunge freezing samples over 40 °C for Cryo-EM","authors":"Iain Harley ,&nbsp;Francesca Mazzotta ,&nbsp;Xhorxhina Shaulli ,&nbsp;Frank Scheffold ,&nbsp;Katharina Landfester ,&nbsp;Ingo Lieberwirth","doi":"10.1016/j.micron.2024.103745","DOIUrl":"10.1016/j.micron.2024.103745","url":null,"abstract":"<div><div>Cryo-EM is now an established tool for examining samples in their native, hydrated states—a leap made possible by vitrification. Utilising this sample preparation method to directly visualise temperature-responsive samples allows for deeper insights into their structural behaviours under functional conditions. This requires samples to be plunge-frozen at elevated temperatures and presents additional challenges, including condensation within the blotting chamber and difficulties in maintaining a stable sample temperatures. Here, we address these challenges and suggest practical strategies to minimise condensation and reduce temperature fluctuations during the plunge-freezing of samples at elevated temperatures (&gt;40 °C). By preheating equipment and reducing chamber humidity and blotting times, we can improve sample preservation and grid reproducibility. These considerations are then demonstrated on poly(N-isopropylacrylamide) microgels, which exhibit a volume phase transition due to temperature changes.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"188 ","pages":"Article 103745"},"PeriodicalIF":2.5,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142643947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Poly(L-lactide)/nano-hydroxyapatite piezoelectric scaffolds for tissue engineering","authors":"Angelika Zaszczyńska ,&nbsp;Arkadiusz Gradys ,&nbsp;Dorota Kołbuk ,&nbsp;Konrad Zabielski ,&nbsp;Piotr K. Szewczyk ,&nbsp;Urszula Stachewicz ,&nbsp;Paweł Sajkiewicz","doi":"10.1016/j.micron.2024.103743","DOIUrl":"10.1016/j.micron.2024.103743","url":null,"abstract":"<div><div>The development of bone tissue engineering, a field with significant potential, requires a biomaterial with high bioactivity. The aim of this manuscript was to fabricate a nanofibrous poly(L-lactide) (PLLA) scaffold containing nano-hydroxyapatite (nHA) to investigate PLLA/nHA composites, particularly the effect of fiber arrangement and the addition of nHA on the piezoelectric phases and piezoelectricity of PLLA samples. In this study, we evaluated the effect of nHA particles on a PLLA-based electrospun scaffold with random and aligned fiber orientations. The addition of nHA increased the surface free energy of PLLA/nHA (42.9 mN/m) compared to PLLA (33.1 mN/m) in the case of aligned fibers. WAXS results indicated that at room temperature, all the fibers are in an amorphous state indicated by a lack of diffraction peaks and amorphous halo. DSC analysis showed that all samples located in the amorphous/disordered alpha' phase crystallize intensively at temperatures just above the T_g and recrystallize on further heating, achieving significantly higher crystallinity for pure PLLA than for doped nHA, 70 % vs 40 %, respectively. Additionally, PLLA/nHA fibers show a lower heat capacity for PLLA in the amorphous state, indicating that nHA reduces the molecular mobility of PLLA. Moreover, piezoelectric constant d₃₃ was found to increase with the addition of nHA and for the aligned orientation of the fibers. <em>In vitro</em> tests confirmed that the addition of nHA and the aligned orientation of nanofibers increased osteoblast proliferation.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"188 ","pages":"Article 103743"},"PeriodicalIF":2.5,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142623952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conservative character of the germ-line cyst organization within enchytraeids (Annelida: Clitellata) ovary – New proofs based on two Achaeta species","authors":"Anna Z. Urbisz ,&nbsp;Rüdiger M. Schmelz ,&nbsp;Karol Małota ,&nbsp;Łukasz Chajec ,&nbsp;Piotr Świątek","doi":"10.1016/j.micron.2024.103732","DOIUrl":"10.1016/j.micron.2024.103732","url":null,"abstract":"<div><div>Ovaries in a minute and mainly aquatic clitellates, collectively termed microdriles, are usually tiny paired gonads localized, depending on the family/subfamily, in segments VI, XI, XII, or XIII. Sometimes, two pairs of ovaries are present in consecutive segments, or ovaries are unpaired. Usually, accumulating yolk (vitellogenic) oocytes detach from ovaries and float in the coelom cavity. This study presents the microscopical analyses of unpaired ovaries found in two representatives of the genus <em>Achaeta</em> (family Enchytraeidae). The ovary is an inconspicuous organ composed of germ-line cysts uniting early meiotic cells. Cysts comprise 16 synchronously developing cells interconnected via cytoplasmic bridges to the central cytoplasmic mass, termed cytophore. Each interconnected cell has one bridge connecting it to the cytophore. Clustering germ cells are enveloped by elongated somatic cells. The developmental synchrony within cysts is lost when one cell per cyst forms prominent microvilli, gather vast amounts of nutrients (yolk), and becomes an oocyte. The remaining 15 cells do not form microvilli, grow slowly, and are regarded as nurse cells that supply the oocyte with organelles and probably macromolecules. Such cysts detach from the ovary and float freely in the segmental cavity. Nurse cells and vitellogenic oocyte are still connected to the ball-like cytophore. Vitellogenic oocytes gather vast amounts of reserve material, mainly protein spheres. Finally, oocytes lose contact with the cytophore, and nurse cells no longer accompany them. The ovary organization and oogenesis scenario observed in this study are broadly similar to that described for other enchytraeid species, such as <em>Enchytraeus albidus</em> and <em>Grania postclitellochaeta</em>, and have been classified as the “Enchytraeus” type of ovary. The obtained results show that despite the unpaired nature of the <em>Achaeta</em> ovary and some differences in ovary morphology and oogenesis between different enchytraeid taxa, the ovaries of these clitellates are consistently composed of 16-celled germ-line cysts equipped with cytophore. Moreover, the presence of cysts equipped with cytophore in the ovaries of the studied <em>Achaeta</em> specimens provides the subsequent evidence that the formation of such germ-line cysts is a conserved aspect of oogenesis within the Clitellata. This consistency in the ovarian and oogenic patterns underscores the evolutionary conservation of these reproductive traits within the Enchytraeidae and clitellate annelids.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"188 ","pages":"Article 103732"},"PeriodicalIF":2.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142639021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Topological analysis of the three-dimensional radiodensity distribution of fish otoliths: Point sampling effects on dimensionality reduction","authors":"João Valerio ,&nbsp;Jonas E. Vasconcelos-Filho ,&nbsp;Borko Stosic ,&nbsp;Wilson R. de Oliveira ,&nbsp;Francisco M. Santana ,&nbsp;Antonio C.D. Antonino ,&nbsp;Paulo J. Duarte-Neto","doi":"10.1016/j.micron.2024.103731","DOIUrl":"10.1016/j.micron.2024.103731","url":null,"abstract":"<div><div>Otoliths are calcified structures found in the inner ears of teleost fish, pivotal in marine biology for studies on metabolism, age, growth, and the identification of fish stocks, potentially leading to sustainable management practices. An important feature of this structure is its density, as it corresponds to modifications in the crystalline form of calcium carbonate during the fish's lifetime, resulting in variations in its final shape. The internal and external 3D radiodensity of otoliths from different species was obtained utilizing micro-computed tomography, however, an appropriate methodology for describing and conducting comparative studies on these data appears to be absent in the current body of literature. Therefore, we study otolith density variations from 3D computed tomography images, employing the <em>Ball Mapper</em> technique of <em>Topological Data Analysis</em>. We focus on reducing the computational cost of this analysis by applying probabilistic sampling and assessing its effects on the density variations provided by the <em>Ball Mapper</em> graph. To determine the sample size, we used the topology to establish what we term \"Topological Sample Validation\", which provided the minimum resolution with the same density information as raw data. Sample representativeness was validated through non-parametric statistical tests on the density variable. Based on the network's structural characteristics, network properties allowed for evaluating similarity between graphs. Besides the small sample size, remarkable correlations were obtained between age and network variables. Additionally, the <em>Ball Mapper</em> technique proved effective as a preprocessing algorithm for tomographic images, enabling the segmentation of undesired features in the object of interest.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"188 ","pages":"Article 103731"},"PeriodicalIF":2.5,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bring your paper into the ‘Fast Lane’ of the editorial process and increase your changes for final acceptance in Micron, The International Research and Review Journal for Microscopy – Part II","authors":"Filip Braet ,&nbsp;Roberto Romani ,&nbsp;Ferdinand Hofer ,&nbsp;Ute Kaiser ,&nbsp;Ray Egerton","doi":"10.1016/j.micron.2024.103727","DOIUrl":"10.1016/j.micron.2024.103727","url":null,"abstract":"<div><div>It has been ten years since the Editors of Micron contributed an editorial offering tips and tricks to help potential contributors navigate the editorial process and improve their chances of manuscript acceptance. In this contribution, we report how the updated guidelines have positively impacted the journal’s content and performance over time, and provide new recommendations and insights to ensure your submission receives the attention it deserves from our editorial team.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"188 ","pages":"Article 103727"},"PeriodicalIF":2.5,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomic force microscopy wide-field scanning imaging using homography matrix optimization","authors":"Liguo Tian ,&nbsp;Lanjiao Liu ,&nbsp;Zihe Liu ,&nbsp;Liqun Cheng ,&nbsp;Hongmei Xu ,&nbsp;Yujuan Chen ,&nbsp;Zuobin Wang ,&nbsp;Jingran Zhang","doi":"10.1016/j.micron.2024.103730","DOIUrl":"10.1016/j.micron.2024.103730","url":null,"abstract":"<div><div>During the offline combination of multiple atomic force microscopy (AFM) images, changes in probe displacement can be affected by dynamic noise, leading to dislocation and tearing in the stitching. To overcome this, we designed a homography matrix optimization method to describe the relative positional relationship between images by constructing the original image matrix and applying singular value decomposition to denoise the homography matrix. Additionally, we implemented a scale-invariant feature transform (SIFT) to extract feature points. To verify the effectiveness of this method, the SIFT + RANSAC (R), SIFT + affine transformation (AT), and oriented FAST and rotated BRIEF (ORB) algorithms were compared with the proposed algorithm. The experimental results demonstrate that the proposed method precisely computes the transformation matrix, thereby guaranteeing the geometric consistency of mosaic imaging. The proposed method preserves the intricate details of the original image and enhances the stitching quality of wide-field images.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"188 ","pages":"Article 103730"},"PeriodicalIF":2.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142503631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plant-derived compounds that target histone acetyltransferases inhibit Trypanosoma cruzi proliferation and viability and affect parasite ultrastructure","authors":"Fernanda Pereira Bortolami ,&nbsp;Aline Araujo Zuma ,&nbsp;Wanderley de Souza ,&nbsp;Maria Cristina Machado Motta","doi":"10.1016/j.micron.2024.103729","DOIUrl":"10.1016/j.micron.2024.103729","url":null,"abstract":"<div><div><em>Trypanosoma cruzi</em>, the causative agent of Chagas disease, exhibits a chromatin structure and organization similar to that of other eukaryotes, undergoing certain epigenetic modifications, such as histone acetylation and deacetylation. Histone acetyltransferase inhibitors have been frequently applied as therapy agents against tumor cells, but their effects on protozoa have not yet been adequately explored. In this study, the effects of three acetyltransferase inhibitors, curcumin, triptolide and anacardic acid, were investigated on <em>T. cruzi</em>. Curcumin was able to inhibit epimastigote and amastigote proliferation and was the most effective compound. Triptolide also impaired <em>T. cruzi</em> proliferation and, along with curcumin, promoted the unpacking of nuclear heterochromatin and nucleolus disorganization. Anacardic acid did not alter parasite growth or viability, but caused ultrastructural changes, such as mitochondrial swelling and cristae enlargement. None of these compounds affected the microtubule cytoskeleton. These findings indicate that histone acetyltransferase inhibitors, especially curcumin, display the potential to be applied in chemotherapeutic studies against <em>T. cruzi</em>. Our results reinforce the necessity of developing new compounds that can be used successfully in therapy against neglected diseases.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"188 ","pages":"Article 103729"},"PeriodicalIF":2.5,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142469727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Freeze response indicators in sugarcane (Saccharum spp. hybrids)","authors":"Minori Uchimiya ,&nbsp;Andre Froes de Borja Reis ,&nbsp;Bruno Cocco Lago ,&nbsp;Kaitlyn Taylor ,&nbsp;Kerstin Höner zu Bentrup ,&nbsp;Diandra Ellis ,&nbsp;Collins Kimbeng","doi":"10.1016/j.micron.2024.103726","DOIUrl":"10.1016/j.micron.2024.103726","url":null,"abstract":"<div><div>A recent series of extreme weather events in Southern U.S. (2022 winter freeze followed by 2023 summer drought) calls for quantitative markers to expedite the release of climate resilient sugarcane varieties. A cluster analysis revealed potential markers for freeze damage including fluorescent amino acids. Of 8 cultivars investigated, tolerant variety HoCP 04–838 sustained 3–5 fold lower stalk fracture from the freeze; contained among the highest fiber; and maintained the lowest particulate juice decomposition byproducts (p&lt;0.05). Based on those observations, fluorescence cellular markers were developed in fiber components of sugarcane to assess cold tolerance. Fluorescence microscopy visualized a cluster of markers in lignin cells around the vascular bundles of HoCP 04–838, within the far-red emission ranges attributable to lipids and other hydrophobic components. Cellular distributions of markers were made visible using fluorescent nanoparticles designed to enhance cellular uptake and imaging at wider wavelengths. Developed chemical phenotyping approaches offer advantages over post-freeze damage assessment currently used in the breeding program, as no genetic marker exists for cold tolerance of sugarcane.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"188 ","pages":"Article 103726"},"PeriodicalIF":2.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sperm ultrastructure in two species of Choanomphalus (Hygrophila: Lymnaeoidea: Planorbidae)","authors":"Elena V. Soldatenko,&nbsp;Andrei B. Shatrov,&nbsp;Anatoly A. Petrov","doi":"10.1016/j.micron.2024.103728","DOIUrl":"10.1016/j.micron.2024.103728","url":null,"abstract":"<div><div>Sperm ultrastructure has been successfully used in gastropod taxonomy and here we attempted to identify potential synapomorphies within the Hygrophila, a group of freshwater lung-bearing gastropods, by examining sperm morphology and ultrastructure in two hygrophilan species of the genus <em>Choanomphalus</em> Gerstfeldt, 1859 (Lymnaeoidea: Planorbidae): <em>Ch. riparius</em> (Westerlund, 1865) and <em>Ch. rossmaessleri</em> (A. Schmidt, 1851). The spermatozoa of both species, like those of other Hygrophila, are divided into a head with an acrosome and nucleus, a midpiece containing a mitochondrial derivative, a glycogen piece, and an endpiece. The acrosome consists of an apical vesicle and a lucent-cored pedestal, plugged basally by compact electron-dense material (acrosomal plug) and separated from the nucleus by a membrane-bound vesicle (basal cap). The midpiece bears apically four surface ridges and contains four glycogen-filled helices inside the mitochondrial derivative. The midpiece is separated from the glycogen piece by an annulus composed of electron-dense material at the tip of the mitochondrial derivative and a hollow cylinder, but the latter appears to consist of two fused structures, making the annulus essentially tripartite. Spermatozoa of the two species show interspecific differences: in <em>Ch. rossmaessleri</em>, the acrosomal plug lacks a stem and the midpiece ridges differ in size, while <em>Ch. riparius</em> has spermatozoa with a stemmed plug and equal-sized ridges. The results of this and earlier studies suggest that sperm ultrastructure can provide synapomorphies for hygrophilan groups at different taxonomic levels. The Lymnaeoidea, one of the two superfamilies of the Hygrophila, appears to be characterised by a lucent-cored acrosomal pedestal, multiple glycogen helices and a tripartite annulus. The presence of a basal plug in the acrosomal pedestal is a possible synapomorphy for the clade uniting Planorbini Rafinesque, 1815 and Segmentinini F.C. Baker, 1945. In Planorbini including the two species of <em>Choanomphalus</em>, the pedestal is separated from the nucleus by a membrane-bound basal cap, a feature readily distinguishing this tribe from Segmentinini and other Lymnaeoidea. The spermatozoa of the two <em>Choanomphalus</em> species differ from those of other Planorbini in having two nuclear keels instead of one, but this character may not be taxonomically reliable.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"188 ","pages":"Article 103728"},"PeriodicalIF":2.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of biomechanical passive synergistic vibration reduction inspired by the structure, morphology, nano-mechanics of the beetles’ hindwing","authors":"Yongwei Yan,&nbsp;Fa Song,&nbsp;Yuping Liu,&nbsp;Wenzhe Wang,&nbsp;Haochen Zhu,&nbsp;Jiyu Sun","doi":"10.1016/j.micron.2024.103725","DOIUrl":"10.1016/j.micron.2024.103725","url":null,"abstract":"<div><div>Using scanning electron microscopy (SEM), a small animal imaging system, and biological tissue sections, the relationships between the flapping vibrations in the hindwings of <em>Trypoxylus dichotomus</em> and their morphology, structure, and hemolymph dynamics were investigated. Based on these findings, a three-degree-of-freedom (3-DOF) model incorporating nano-mechanical properties was developed to investigate spanwise passive synergistic vibration reduction (PSVR) in the hindwing elements. To ensure precision, the Runge-Kutta and incremental harmonic balance (IHB) methods were employed for both solving and comparing solutions. Analysis of the spanwise force (<em>F</em>_OX) signals confirmed the validity of the PSVR model. Parametric analysis revealed that reducing system mass and stiffness increased the resonance amplitude while shifting the resonance frequency in the opposite direction. The resonance frequency and flexible deformation amplitude of the hindwing system could be controlled by adjusting mass and stiffness within the synergistic framework. The mass and damping of the wing base, along with the stiffness of the wing membrane, were identified as critical factors in the system. This model provides valuable insights into the PSVR mechanism, potentially informing the design and manufacture of bionic flexible flapping wings.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"188 ","pages":"Article 103725"},"PeriodicalIF":2.5,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}