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This letter presents a soft compact valve inducing self-excited vibration to be aimed for simplification of piping, power saving and downsizing the total system for pneumatic soft mobile robots generating traveling waves. The presented device is composed of flat tubes, permanent magnets, and restraint parts. It is capable of switching the inner pressure among three isolated chambers alternately and periodically by using the constant air pressure supplied from a single line. In this letter, we describe the driving principle of the valve to switch different chambers automatically, while detecting the pre-set pressure inside each chamber without sensors. The prototype has a flexible sheet structure with a mass of 5.1 g and a thickness of 10 mm, and was examined to induce a self-excited vibration of 0.6 Hz by air supply of 80 kPa. Moreover, it was also confirmed that when the developed valve was mounted on a flexible seat-type mobile, it was possible to propel through a narrow space with 25 mm gap smoothly while generating traveling waves. Finally, the effectiveness of the proposed valve is discussed through the experimental results.

Introduction Regenerative therapy using chondrocyte sheets is effective for osteoarthritis. The clinical application of chondrocyte sheet therapy is expected to be further advanced by the use of a feasible cryopreservation technique. Previously, we developed a chondrocyte sheet vitrification method; however, it was too complex to be used for routine clinical application. Here, we aimed to develop a prototype method for vitrifying chondrocyte sheets for clinical practice. Methods We developed a “circulating vitrification bag” as a container to process cell sheets for vitrification in an efficient and sanitary fashion. Moreover, we invented the “vitrification storage box”, which is useful for the vitrification of cell sheets, long-term preservation, and transportation. These devices were used to vitrify rabbit chondrocyte sheets, which were then assessed for their structural characteristics and the viability of the component cells after rewarming. Results In all cell sheet samples (n = 7) vitrified by the circulating vitrification bag method, the integrity of the sheet structure was maintained, and the cell survival rate was similar to that of non-vitrified samples (91.0 ± 2.9% vs. 90.0 ± 3.0%). Proteoglycan and type II collagen, which are major components of cartilage, were densely and evenly distributed throughout the chondrocyte sheet subjected to vitrification similarly to that observed in the non-vitrified sheet. After long-term storage using the vitrification storage box, the cell sheets maintained normal structure and cell viability (survival rate: 81.2 ± 1.0% vs. 84.3 ± 1.8%) compared to the non-vitrified sheet. Conclusion Our results indicate that the circulating vitrification bag method is an effective approach for realizing the clinical application of vitrified chondrocyte sheets. The vitrification storage box is also useful for the long-term preservation of vitrified cell sheets, further enhancing the feasibility of the clinical application of cryopreserved chondrocyte sheets., Highlights • We developed a new device and method for the cryopreservation of cell sheets. • The method and device efficacy were evaluated using vitrified rabbit chondrocyte sheets. • Our approach allows efficient clinical application of vitrified cell sheets.

Graphyne sheets and nanotubes (GyNTs) are known as novel low-dimensional, i.e., two-dimensional (2D) and one-dimensional (1D), semiconducting carbon allotropes that can be used in nanoelectronics and therefore merit fundamental investigation. Among such materials, attention is currently focused on γ-graphyne-1, a member of the graphyne family that exhibits a maximum cohesive energy of −8.37 eV and chemical stabilityhas been focused. In this research density functional tight binding (DFTB) method in the investigation of electrical property under geometrical variation is reported and a detailed description of electrical as well as stability properties for γ-graphyne-1 in uniform strain is illustrated. It is concluded that the γ-graphyne-1 family of materials exhibit semiconducting properties with large bandgap values from 1.34 eV for the sheet structure to 1.93 eV for (3,0) armchair γ-graphyne-1 nanotubes. The γ-graphyne-1 family also displays elastic properties, enabling the modulation of the bandgap and engineering of the effective mass using homogeneous strain. These properties, along with the nonmetallic behavior of GyNTs, make them perfect materials for the design of novel electronic devices.

As a new type of variable thickness sheet structure, the TRB (tailor rolled blank) has good prospects for the development of lightweight materials in the automotive industry. However, springback is a key issue in production. Research on TRB springback characteristics has great significance for further applications due to variations in the sheet thickness and gradient distribution of the material mechanical properties. In this study, the springback characteristics of TRBs were investigated by means of the finite element code ABAQUS/USDFLD and experiments taking cylindrical bending as an example. The results showed that the cylindrical bending process of the TRB gradually evolved from three-point bending to four-point bending and, finally, to multipoint bending. At same time, the gradient of the thickness leads to the nonuniform longitudinal distribution of the von Mises stress. On the contrary, larger bending angles can be achieved by reducing R and improving Rd, but t/T has little effect on the bending angles. In terms of the influence of springback, increasing Rd and reducing R and t/T can lead to a smaller springback angle. This project provided an important opportunity to advance the understanding of TRB springback characteristics.

The title compound, C15H10I2O, is a halogenated chalcone formed from two iodine substituted rings, one para-substituted and the other meta-substituted, linked through a prop-2-en-1-one spacer. The crystal structure shows the mol­ecules contain halogen bonds which are always between equivalent iodine atoms, either para–para or meta–meta., The title compound, C15H10I2O, is a halogenated chalcone formed from two iodine substituted rings, one para-substituted and the other meta-substituted, linked through a prop-2-en-1-one spacer. In the mol­ecule, the mean planes of the 3-iodo­phenyl and the 4-iodo­phenyl groups are twisted by 46.51 (15)°. The calculated electrostatic potential surfaces show the presence of σ-holes on both substituted iodines. In the crystal, the mol­ecules are linked through type II halogen bonds, forming a sheet structure parallel to the bc plane. Between the sheets, weak inter­molecular C—H⋯π inter­actions are observed. Hirshfeld surface analysis showed that the most significant contacts in the structure are C⋯H/H⋯C (31.9%), followed by H⋯H (21.4%), I⋯H/H⋯I (18.4%). I⋯I (14.5%) and O⋯H/H⋯O (8.1%).

Pulp fiber airlaid nonwovens were bonded with three binder formulations in a spray and foam process. The binders were: a commercial acrylic dispersion binder, a commercial bio-containing acrylic binder; and a citric acid-carboxymethyl cellulose mixture (CACMC) (1:1 by-weight). The binder solutions were applied at same concentrations onto A4-size airlaid sheets (80 gsm) under a vacuum with 2-sided spraying and 1-sided foam coating. The sheet structure, dry and wet tensile properties, and total absorption capacity were compared. The foam application densified and bulk bonded the sheets, whereas the spray application induced surface bonding. These factors fundamentally influenced the measured sheet properties. The dry tensile strength was linearly correlated with the relatively low binder dosages. The CACMC binder exposed the differences in the binder application processes well, and lead to strong sheets with small elongation and highly application method-dependent absorption capacity compared to acrylic binders.

T he highest total color difference values ( ∆E) were found in the panels produced with the similar proportions of waste paper and OCC into gypsum (A4: 6.09; B4: 5.79). These boards have also show highest CIE whiteness reduction (A4: -33.19; B4: -28.44). With the help of FTIR, some chemical groups are modified to some extent but similar functional groups were observed in surface of boards. For A- and C-type boards, similar TGA degradation trends (spectra) were observed while the B-type panels show markedly higher mass loss, especially at initial temperature stage (100-120 0 C). This is probably because of the presence of some non-cellulosic materials (i.e. starch, silica, etc.) and the high rate of lignin in sheet structure of OCC material. The flame propagation characteristic of the surfaces of all test boards shows that the flame did not reach the threshold limit of 150 mm. These indicates, even if the source of fire is not removed, flame did not reach the threshold limit that boards that could be classified as non-flammable material class according to TS EN-ISO 11925-2 standard. The heat insulation properties of the test sample were found to be lowered with addition of lignocellulosic material to the gypsum structure. It was seen that waste paper ratio in gypsum structure higher than 10% (A3 to A6 boards) show better insulation properties than counterpart OCC (B-types) and secondary fiber based (C-types) gypsum boards. In general, reduction heat transfer in average values of samples attracted attention as compared with control specimens. Interestingly, the boards are indicated best insulation properties as mentioned above, show higher mass loss too. The highest mass loss for A-type boards found to be 3.52% (A6), for B-type boards 3.46% (B6) and for C-type boards 3.28% (C8).

An organic–inorganic hybrid CuII–ErIII heterometallic arsenotungstate Na3[Cu(en)2(H2O)][Cu(en)2]1.5[H3Er(α-AsW11O39)2]·4H2O (1) (en = ethylenediamine) has been hydrothermally synthesized and structurally characterized by elemental analyses, IR and UV spectra, X-ray photoelectron spectroscopy (XPS), cyclic voltammetry and single-crystal X-ray diffraction. 1 displays an organic–inorganic 2-D sheet structure constructed by sandwich-type [H3Er(α-AsW11O39)2]8− fragments and [Cu(en)2]2+ connectors. From the topological viewpoint, if the [H3Er(α-AsW11O39)2]8− fragments are viewed as 3-connected nodes and [Cu(en)2]2+ connectors are considered as linkers, the 2-D sheet can be simplified into a 2-D (6,3)-network topology. Keywords: Polyoxometalate, Arsenotungstate, CuII–ErIII heterometallic derivative, Spectroscopic characterization

Hodgesmithite, ideally (Cu,Zn)6Zn(SO4)2(OH)10·3H2O, is a new copper zinc sulfate mineral from the Block 14 Opencut, Broken Hill, New South Wales, Australia. Electron microprobe analysis provided the empirical formula Cu4.84,Zn2.16,Cd0.04[(SO4)1.89,(SiO4)0.12]2.01(OH)9.82·3.15H2O based on 21 oxygen atoms per formula unit. Hodgesmithite is trigonal, space groupP3, witha= 8.1905 (12),c= 7.0990 (14) Å,V= 412.43 (12) Å3andZ= 1. The crystal structure of hodgesmithite,R1= 0.0272 for 5145 reflections withFo> 4σ(Fo) measured with synchrotron X-ray radiation (λ = 0.71080 Å), contains interrupted sheets of edge-sharing Cu(O,OH)6octahedra in the (001) plane. Every seventh octahedral site is vacant and capped by a ZnO4tetrahedron and an SO4tetrahedron which are attached to the sheet above and below this position. The sheets are additionally decorated on one side by SO4tetrahedra that share a vertex incident to three Cu—O(apical) bonds. Interstitial H2O groups lie between the sheets. ZnO4tetrahedra share vertices with SO4tetrahedra from the adjacent sheet to provide linkage between the sheets in thecdirection.

Humanity has been continuously threatened by epidemics and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has shown greater epidemic potential. According to the World Health Organization, measures such as rapid diagnosis, immediate isolation, and precautionary contact tracing are key tools of epidemic control. The method of detection or testing is critical in this epidemiological control, where SARS-CoV-2-positive cases are increasingly growing, leading to community infection. Immunochromatographic test kits have been described for the diagnosis of various infectious diseases because of their rapid scalability, convenient use, and prompt validation. The benefits of the immunochromatographic test kits include evaluation of the sample in approximately 20 minutes, lower cost per sample, and simple directions to use. Such test kits are composed of an uncut sheet structure that is protein conjugated, labeled with markers, and reagents coated in a nitrocellulose membrane. The need for thorough vetting is a major concern for the Central Drugs Standard Control Organization, Indian Council of Medical Research and other regulators, as more businesses are rushing to produce serologic test kits for SARS-CoV-2 worldwide. Initial reports of 86%−89% sensitivity and 84.2%–98.6% specificity were reported for these kits. Nonetheless, many national reports show variability in test accuracy significantly among various commercial suppliers. The virus’s more recent mutated strains (B.1.1.7, B.1.617, and B.1.351) have also raised concerns about their detectability using these test kits. In India, manufacturers are developing rapid test kits to detect SARS-CoV-2 by importing pre-antigen or antibody-coated uncut sheets from vendors and then cutting them into strips. Such sheets also have problems with specificity and are expensive. The possibility of developing kits with an indigenous protein coating and conjugation to detect antigens and antibodies needs to be explored by Indian researchers. This communication describes techniques to develop precise rapid test kits for detecting SARS-CoV-2. © 2021

Conformational changes in amyloidogenic proteins, such as β-amyloid protein, prion proteins, and α-synuclein, play a critical role in the pathogenesis of numerous neurodegenerative diseases, including Alzheimer’s disease, prion disease, and Lewy body disease. The disease-associated proteins possess several common characteristics, including the ability to form amyloid oligomers with β-pleated sheet structure, as well as cytotoxicity, although they differ in amino acid sequence. Interestingly, these amyloidogenic proteins all possess the ability to bind trace metals, can regulate metal homeostasis, and are co-localized at the synapse, where metals are abundantly present. In this review, we discuss the physiological roles of these amyloidogenic proteins in metal homeostasis, and we propose hypothetical models of their pathogenetic role in the neurodegenerative process as the loss of normal metal regulatory functions of amyloidogenic proteins. Notably, these amyloidogenic proteins have the capacity to form Ca2+-permeable pores in membranes, suggestive of a toxic gain of function. Therefore, we focus on their potential role in the disruption of Ca2+ homeostasis in amyloid-associated neurodegenerative diseases.

Recently, two-dimensional transition metal dichalcogenides (2D TMDCs) have drawn certain attentions in many fields. The unique and diversified electronic structure and ultrathin sheet structure of 2D TMDCs offer opportunities for moving ahead of other 2D nanomaterials such as graphene and expanding the wide application of inorganic 2D nanomaterials in many fields. For a better understanding of 2D TMDCs, one needs to know methods for their synthesis and modification, as well as their potential applications and possible biological toxicity. Herein, we summarized the recent research progress of 2D TMDCs with particular focus on their biomedical applications and potential health risks. Firstly, two kinds of synthesis methods of 2D TMDCs, top-down and bottom-up, and methods for their surface functionalization are reviewed. Secondly, the applications of 2D TMDCs in the field of biomedicine, including drug loading, photothermal therapy, biological imaging and biosensor were summarized. After that, we presented the existing researches on biosafety evaluation of 2D TMDCs. At last, we discussed major research gap in current researches and challenges and coping strategies in future studies.

Background: The outbreak of coronavirus disease 2019 (COVID-19) has led to substantial infections and mortality around the world. Fast screening and diagnosis are thus crucial to quick isolation and clinical intervention. Methods: Patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A/B, and respiratory syncytial virus (RSV), as well as healthy controls, were included in this study. All viral infections were confirmed by reverse transcriptase PCR (RT-PCR). The serum samples were measured by attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR). Multivariate and statistical analysis was performed to differentiate between or among groups. Findings: We found that the most discriminatory bands for COVID-19 vs. control classification were amide I, amide II, and νs(PO2−) in original spectra and centered at 1632, 1545, 1400, 1079, and 1037 cm-1 in the second derivative infrared (SD-IR) spectra. Normal controls, non-severe, and severe COVID-19 patients were well separated by unsupervised methods. ATR FT-IR coupled with partial least square discriminant analysis (PLS-DA) was effective to differentiate COVID-19 from normal controls and other respiratory viral infections with the area under the receiver operating characteristic curve (AUROC) of 0·9866 (95%CI 0·9721-0·9939). Interpretation: The band centered at 1633 cm-1 in the SD-IR spectra is mainly attributed to the β-pleated sheet structure from immunoglobulins. Increases in antibody levels and dysregulation of phospholipids can be derived from the measured spectra. The serum FT-IR spectra exhibited “chemical fingerprints” towards different viral infections. Funding Statement: This work was funded by the National Natural Science Foundation of China (52041701). Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: This study was approved by the Ethics Committees from Tsinghua University and Peking Union Medical College Hospital.

The research aims was to describe the structure of a Narrative Essay rhetoric Describing Student primary school teacher education STKIP PGRI Lubuklinggau, using qualitative research methods. As for the steps in analyzing the following: a). data analysis will be started from an analysis of the "text" of the text of a collection of short stories which is read repeatedly, b). After that number sort on a collection of short stories, followed by c). give the numbers sort as well on each of the paragraphs in the short story collection, d). Then give the code based on the categories of items that appear in each paragraph (identify text elements), e). Make a general description of the sheet structure of rhetoric that appeared every paragraph, f). Further describes and discusses the results of data analysis, g). Draw conclusions from the results of research. The results of this study show that in general the rhetoric of narrative essay with using theory of generic text labov has a pattern variable that is 1). O contained on the (KR 8 dan KR 18), 2). O – PP contained on the (KR 3, KR 4,KR 5,KR 7, KR 13, KR 17,KR 20, KR 22,KR 24, KR 27, R 28, KR 29, KR, 32,dan KR 34), 3). O – PP – R contained on the ( KR 1, KR 2,KR 6,KR 9,KR 10, KR 11,KR 12,KR 14, KR 16,KR 19, KR 21,KR 23, KR 25 dan KR 26,dan 4). O – PP – R – K contained on the (KR 15,KR 30 dan KR 31). Beside it from 33 describing These consist of 33 bouquet that has elements of orientation (O), the describing has elements of perumitan events (PP) totaled 29 describing while elements of the resolution (R) totaled 17 describing, and last element of koda (K) amounted to 3 wreaths. Here's an explanation of each of the structures contained in the narrative essay. Keyword: Rethoric Structure, Describing, and Narrative

The aggregation cascade of disease‐related amyloidogenic proteins, terminating in insoluble amyloid fibrils, involves intermediate oligomeric states. The structural and biochemical details of these oligomers have been largely unknown. Here we report crystal structures of variants of the cytotoxic oligomer‐forming segment residues 28–38 of the ALS‐linked protein, SOD1. The crystal structures reveal three different architectures: corkscrew oligomeric structure, nontwisting curved sheet structure and a steric zipper proto‐filament structure. Our work highlights the polymorphism of the segment 28–38 of SOD1 and identifies the molecular features of amyloidogenic entities.

The title crystals are isomorphous, and form centrically stacked planar sheets formed by CN⋯I and NC⋯I short contacts., The title crystals, C7H2I3N, are isomorphous. Both mol­ecules lie across two crystallographic mirror planes and a twofold axis. The principal supra­molecular inter­action is centric R 2 2(10) CN/NC⋯I short contacts involving both ortho I atoms, with two contacts bis­ecting each cyano and iso­cyano group. These form ribbons along [010] and give rise to a planar sheet structure parallel to (100). All pairs of adjacent sheets have centric stacking, a mode not previously reported for sheets of this type. This study completes the series of homo-2,4,6-trihalobenzo­nitriles, in which I atoms give the strongest CN⋯X and NC⋯X inter­actions (X = F, Cl, Br, I).

Aβ42 peptides can form helix and sheet structure under different conditions. The conformational conversion is closely associated with Aβ peptides aggregation and their neurotoxicity. But the transition from helix to sheet is not be clearly understood. In this study we performed microsecond timescale MD simulations of Aβ42 peptide to investigate the conformation transition from α-helix to β-sheet. Markov state model (MSM) was built to facilitate identification of crucial intermediate states and possible transition pathway. Based on the analysis, we found that the region Y10-A21 in the middle of Aβ42 peptide plays an initial role in this transition. MSM model revealed that the collapse of helical structure in this region might trigger the formation of sheet structure. Moreover, we further simulated the aggregation of Aβ42 peptides with different conformations. We found that the Aβ42 peptides forming sheet structure have higher aggregation potential compared with peptides with helix structure. These results demonstrate that we can prevent the aggregation of Aβ42 peptides by stabilizing the helix structure in the region of Y10-A21. In addition, this study provides new insight into better understanding the conformational transition and aggregation of Aβ42 peptides.

Natural enzymes are expected to be used in biomedical fields due to their extensive antibacterial activity, good biocompatibility and resistance to bacteria. Herein, we constructed a multi-enzyme protein assembly with ultrathin single protein sheet structure by the strategy of interface assembly and developed an efficient and intelligent antibacterial system based on the combination of multi-enzymes. The multi-enzyme protein assembly not only displayed extremely high antibacterial activity, but can also be turned on and off through the denaturant induced folding and unfolding of natural enzymes, and this process can be realized for several reversible cycles. Such an intelligent antibacterial material provides the possibility for its application in biomedical and other fields.

In the title compound, the 1,3-dioxane ring has an envelope conformation. In the crystal, classical O—H⋯O and N—H⋯O hydrogen bonds link mol­ecules into a sheet structure, and a weak inter­molecular C—H⋯Cl inter­action extends the sheet structure into a three-dimensional network., In the title compound, C10H14Cl3NO5, the five-membered dioxolane ring adopts an envelope conformation with the C atom bonded to the butenoate side chain as the flap. It deviates from the mean plane of the other atoms in the ring by 0.446 (6) Å. In the crystal, mol­ecules are connected by O—H⋯O hydrogen bonds into helical chains running along the b-axis direction. The chains are linked into a sheet structure parallel to (001) by an N—H⋯O hydrogen bond. These classical hydrogen bonds enclose an R 4 4(24) graph-set motif in the sheet structure. Furthermore, a weak inter­molecular C—H⋯Cl inter­action expands the sheet structures into a three-dimensional network.

Globular proteins composed of different secondary structures and fold types were examined by synchrotron radiation circular dichroism spectroscopy to determine the effects of dehydration on their secondary structures. They exhibited only minor changes upon removal of bulk water during film formation, contrary to previously reported studies of proteins dehydrated by lyophilization (where substantial loss of helical structure and gain in sheet structure was detected). This near lack of conformational change observed for globular proteins contrasts with intrinsically disordered proteins (IDPs) dried in the same manner: the IDPs, which have almost completely unordered structures in solution, exhibited increased amounts of regular (mostly helical) secondary structures when dehydrated, suggesting formation of new intra-protein hydrogen bonds replacing solvent-protein hydrogen bonds, in a process which may mimic interactions that occur when IDPs bind to partner molecules. This study has thus shown that the secondary structures of globular and intrinsically disordered proteins behave very differently upon dehydration, and that films are a potentially useful format for examining dehydrated soluble proteins and assessing IDPs structures.

Hard carbon with large interlayer spacing is suitable as the anode material for sodium-ion batteries. Rape seed shuck derived lamellar hard carbon is synthesized through hydrothermal and pyrolysis processes. As the anode, it exhibited good cycling stability, delivering a capacity of 143 mAh g −1 after 200 cycles at 100 mA g −1 . The promising performances are attributed to the sheet structure with expanded interlayer distance (0.39 nm) and much void which can lower the sodium-ion insertion-extraction barrier and promote Na-ion diffusion and storage. The effect of pyrolysis temperature on the performance is also investigated.

In the title dimedone derivative, the 4-hy­droxy-3-meth­oxy­benzyl substituent adopts a sofa conformation. In the crystal, mol­ecules are assembled into a sheet structure parallel to the ab plane via O—H⋯O hydrogen bonds., In the title compound, C16H20O4, a new starting compound for the synthesis of various heterocycles, the partially saturated six-membered ring adopts a sofa conformation. An intra­molecular O—H⋯O hydrogen bond is observed in the guaiacol residue. In the crystal, mol­ecules are assembled into a sheet structure parallel to the ab plane via O—H⋯O hydrogen bonds. The hydrogen-bond pattern is described by an R 4 4(28) graph-set motif. The sheets are further linked by C—H⋯O hydrogen bonds into a three-dimensional network.

The p53 protein is a commonly studied cancer target because of its role in tumor suppression. Unfortunately, it is susceptible to mutation-associated loss of function; approximately 50% of cancers are associated with mutations to p53, the majority of which are located in the central DNA-binding domain. Here, we report molecular dynamics simulations of wild-type (WT) p53 and 20 different mutants, including a stabilized pseudo-WT mutant. Our findings indicate that p53 mutants tend to exacerbate latent structural-disruption tendencies, or vulnerabilities, already present in the WT protein, suggesting that it may be possible to develop cancer therapies by targeting a relatively small set of structural-disruption motifs rather than a multitude of effects specific to each mutant. In addition, α-sheet secondary structure formed in almost all of the proteins. α-Sheet has been hypothesized and recently demonstrated to play a role in amyloidogenesis, and its presence in the reported p53 simulations coincides with the recent re-consideration of cancer as an amyloid disease.

This study focused on web forming at a 5–10% consistency range, termed Ultra High Consistency (UHC). The study continued work done by Gullichsen with his research groups (1981–2007) and combined it with the HC forming research done by Valmet (HC, 1999–2004). The hypothesis was that by utilizing a rotor to fluidize suspension and a wedge to eliminate the free jet and thus prevent reflocculation, web forming at UHC is feasible at commercial speeds. The research method was experimental. The bulk of the research was conducted at pilot scale. A new UHC headbox was designed and mounted on a pilot former. The key elements of the headbox are the rotor and the wedge. As fluidization forms the base for UHC forming, this was evaluated at the pilot former using image analysis. In addition, fluidization was studied using a laboratory-scale device. Besides basic paper analysis, X-ray microtomography and sheet splitting methods were utilized to analyze the sheet structure. The results show that forming is possible within the focus area, 5–10% consistency and machine speeds of 150–600 m/min, although the operation potential of the UHC former is even wider. The results demonstrate that the wedge is needed for successful UHC forming, but the rotor is not required, providing the flow rate is sufficiently high. This indicates that various forces induced by the flow itself can be adequate to fluidize suspension for forming. The critical Reynolds number of full fluidization was found to be 200–250. The Reynolds numbers were estimated utilizing the linear dependencies found between the apparent viscosity and consistency, using the maximum mean flow velocities inside the headbox, and neglecting the possible rotation of the rotor. The corresponding critical flow velocities at 10% consistency are 12 and 19 m/s for a eucalyptus and pine pulp. The velocities are on average 70 and 60% lower than those given in the literature (40–50 m/s). The results reveal that the fiber orientation of UHC sheets is planar, the floc size of the web increases with consistency, the internal bond increases linearly with the floc size, and the tensile strength appears to decrease with increasing floc size. In consequence, it is postulated that the increase in the out-of-plane strength at the expense of in-plane strength with the consistency increase results from a more flocculated structure. Tiivistelmä Tutkimus keskittyi rainanmuodostukseen 5–10 % sakeudessa. Sakeusalue nimitettiin ultra korkeaksi (lyhenne UHC). Tämä työ jatkoi Gullichsenin ja hänen tutkimusryhmiensä tutkimustyötä (1981–2007) ja samalla yhdisti sen Valmetin tekemään suursakeusrainaustutkimukseen (HC, 1994–2004). Työn hypoteesina oli, että käyttämällä roottoria massan fluidisoimiseen sekä ns. wedgeä eliminoimaan vapaa suihku ja estämään jälleenflokkaantuminen, rainanmuodostus UHC-sakeudessa on mahdollista kaupallisissa nopeuksissa. Tutkimusmetodi oli kokeellinen. Pääosa tutkimuksesta suoritettiin koekonemittakaavassa. Uusi UHC-perälaatikko suunniteltiin ja asennettiin koeformeille. Perälaatikon pääelementit ovat pyörivä roottori ja wedge. Koska fluidisointi muodostaa UHC-rainauksen perustan, fluidisointia evaluoitiin koekoneella käyttäen kuva-analyysiä sekä tutkittiin lisäksi käyttäen röntgenmikrotomografia ja arkin halkaisu -metodeja. Tulokset osoittavat, että rainaaminen on mahdollista määritellyllä fokusalueella, 5–10 %sakeudessa ja konenopeudella150–600 m/min, joskin UHC-formerin toimintapotentiaali on vieläkin laajempi. Tulokset osoittavat, että wedge tarvitaan onnistuneeseen UHC-muodostamiseen, mutta roottoria ei tarvita, mikäli virtausnopeus on riittävän suuri. Tämä tarkoittaa, että virtauksen aikaansaamat voimat voivat itsessään olla riittäviä massan fluidisoimiseksi rainaamista varten. Täyden fluidisaation kriittisen Reynoldsin luvun havaittiin olevan välillä 200–250. Reynoldsin luvut arvioitiin käyttäen löydettyjä viskositeetin ja sakeuden välisiä lineaarisia riippuvuuksia, päävirtauksen maksiminopeuksia perälaatikossa ja jättäen huomioon ottamatta mahdollinen roottorin pyöriminen. Reynoldsin lukuja vastaavat kriittiset virtausnopeudet 10 % sakeudessa ovat eukalyptus- ja mäntymassalla 12 ja 19 m/s. Nopeudet ovat keskimäärin 70 ja 60 % pienempiä kuin kirjallisuudessa annetut (40–50 m/s). Tulokset osoittavat, että UHC-arkeissa kuituorientaatio on tasomainen, rainan flokkikoko kasvaa sakeuden kasvaessa, palstautumislujuus kasvaa lineaarisesti flokkikoon kanssa ja vetolujuus näyttäisi laskevan flokkikoon kasvaessa. Näin ollen esitetään, että sakeuden kasvaessa tapahtuva palstautumislujuuden kasvu tasolujuuksien kustannuksella johtuu flokkaantuneemmasta rakenteesta.

Thrombolite is a non-laminated fabric of microbial carbonate, which is in sharp contrast with stromatolite that is characterized by the laminated fabric. Thrombolite bioherm developed in Cambrian Zhangxia Formation in the Western part of Shandong Province mainly consists of clots that are composed of dense micrite and microspar. Both the remain of calcified extracellular polymers (EPS) and calcified cyanobacteria fossils are observed within the clot that makes up thrombolite. Within the complex microscopic fabrics, it can be observed that the remain of calcified EPS are marked by the spherical structure, the sheet structure, the mat structure, and the honeycomb-like structure, which further indicate that the formation of clots within thrombolite should belong to a complex organic mineralization process. Together with both the dense micrite and the calcified cyanobacteria fossil, the calcified EPS provides an important clue for understanding the enigmatic formation mechanism of thrombolites. Therefore, this study can provide an important clue and thinking approach for further research in the future.

The use of steel-aluminum heterogeneous sheets and its adhesive-coated hemming process for cover parts helps to realize the lightweight of the car body, and its vibration characteristics greatly affect the NVH characteristics of the vehicle. Traditional cover parts vibration characteristics research ignores the influence of adhesives. Facing the higher performance of lightweight cover parts systems, it is necessary to establish a “sandwich”; multi-material structure model consisting of aluminum outer sheet-ductile structural adhesive layer-steel inner sheet. Based on the typical straight edge-flat surface unit structure of cover parts, this paper established a calculation model for the vibration characteristics of steel-aluminum heterogeneous sheet adhesive structure, and the effect of adhesive thickness is quantified through experimental verification. The results show that the natural frequencies of the finite element calculation model and the experimental model are highly consistent in the first two modes, and the first two natural frequencies become larger as the thickness of the adhesive increases. The shell element of finite element calculation model based on the laminated sheet vibration theory can effectively simulate the calculation of the first two modes of the steel-aluminum heterogeneous sheet adhesive structure.

Controllable Cu 2 O nanocrystals with petal-like structure were successfully synthesized by the introduction of a concentrated ripening process into the methodology developed by the preparation of Cu 2 O nanocubes. The mechanism of shape evolution of petal-like Cu 2 O nanoflowers was proposed to reveal the concentrated ripening process as a novel strategy in the fabrication of special structured nanocrystals. Cu 2 O nanoflowers with petal-like structure exhibited enhanced activity and stability in hydrogen evolution compared with Cu 2 O naonocubes via the same route. The enhanced activity and stability of Cu 2 O nanoflowers was attributed to their unique petal-like sheet structure, which exhibited large BET surface area and pore volume. The results of cycle experiments also confirmed the enhanced stability of Cu 2 O nanoflower, which the H 2 evolution rate of Cu 2 O nanoflower only decreased by 5.5% after the 4th cycles.

In the crystal of the title compound, a supra­molecular sheet structure is formed through N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds., In the title compound, C19H19NO5, the amide carbonyl O atom is positioned anti to the other two carbonyl O atoms. The 4-hy­droxy­hydro­cinnamate fragment is disordered over two positions with an occupancy ratio of 0.729 (12):0.271 (12). The N—(C=O)—C plane of the acetamide group and the acetate O—(C=O)—C plane are almost co-planar; the acetamide plane makes dihedral angles of 1.9 (6) and 16.0 (19)°, respectively, with the acetate planes of the major and minor occupancy components. In the crystal, N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules into a supra­molecular sheet structure parallel to (102).

Nacre (mother of pearl) is an attractive model for the development of new materials. Its sheet structure of alternating layers of calcium carbonate and an organic matrix confers it highly desirable properties such as high toughness and strength. In this study, we produce a nacre-inspired composite material using only bacterially-produced components. Calcium carbonate is crystallized via the action of ureolytic bacteria. After each crystallization event, we apply bacterially produced γ-polyglutamate (PGA) to the sample, which promotes layering compared to the PGA-free control. We show that the combination of these two compounds yields a layered material reminiscent of nacre, showing a way towards the biotechnological production of new, nacre-inspired materials.

Waterproof-breathable (WB) materials with outstanding waterproofness, breathability, and mechanical performance are critical in diverse consumer applications. Electrospun nanofibrous membranes with thin fiber diameters, small pore sizes, and high porosity have attracted significant attention in the WB fabric field. Hot-press treatment technology can induce the formation of inter-fiber fusion structures and hence improve the waterproofness and mechanical performance. By combining electrospinning and hot-press treatment technology, polyurethane/fluorinated polyurethane/thermoplastic polyurethane/alkylsilane-functionalized graphene (PU/FPU/TPU/FG) nanofiber WB fabric was fabricated. Subsequently, the morphologies, porous structure, hydrostatic pressure, water vapor transmission rate (WVTR), and stress&ndash, strain behavior of the nanofiber WB fabric were systematically investigated. The introduction of the hydrophobic FG sheet structure and the formation of the inter-fiber fusion structure greatly improved not only the waterproofness but also the mechanical performance of the nanofiber WB fabric. The optimized PU/FPU/TPU-50/FG-1.5 WB fabric exhibited an excellent comprehensive performance: a high hydrostatic pressure of 80.4 kPa, a modest WVTR of 7.6 kg m&minus, 2 d&minus, 1, and a robust tensile stress of 127.59 MPa, which could be used to achieve various applications. This work not only highlights the preparation of materials, but also provides a high-performance nanofiber WB fabric with huge potential application prospects in various fields.

Alzheimer&rsquo, s disease (AD) is one of the most common neurodegenerative diseases and a widespread form of dementia. Aggregated forms of the amyloid &beta, peptide (A&beta, ) are identified as a toxic species responsible for neuronal damage in AD. Extensive research has been conducted to reveal the aggregation mechanism of A&beta, However, the structure of pathological aggregates and the mechanism of aggregation are not well understood. Recently, experimental studies have confirmed that the &alpha, sheet structure in A&beta, drives aggregation and toxicity in AD. However, how the &alpha, sheet structure is formed in A&beta, and how it contributes to A&beta, aggregation remains elusive. In the present study, molecular dynamics simulations suggest that A&beta, adopts the &alpha, strand conformation by peptide-plane flipping. Multiple &alpha, strands interact through hydrogen bonding to form &alpha, sheets. This structure acts as a nucleus that initiates and promotes aggregation and fibrillation of A&beta, Our findings are supported by previous experimental as well as theoretical studies. This study provides valuable structural insights for the design of anti-AD drugs exploiting the &alpha, strand/&alpha, sheet structure.

Molecules of the title compound, C7H2Br2ClN (RNC), are bisected by a mirror plane that passes through the chloro and isocyano groups. The isocyano C atom is bisected by two NC...Br contacts, one per Br atom. The resulting centric R 2 2(10) rings form ribbons along [010], which align to form a nearly planar sheet structure that is very similar to the sheets observed in several related 2,6-dibromophenyl cyanides and isocyanides. The crystal of RNC is isomorphous with the corresponding cyanide, with solely translational stacking between sheets. This is in contrast to the 2,4,6-tribromophenyl cyanide and isocyanide, which occur as different polytypes.