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Isolated gametes can be used to investigate fertilization mechanisms, and probe distant hybridization between different species. Pollen grains of wheat and Setaria viridis are tricellular, containing sperm cells at anthesis. Sperm from these plants were isolated by breaking open pollen grains in a osmotic solution. Wheat ovules were digested in an enzyme solution for 20 min, and then transferred to an isolation solution without enzymes to separate egg cells from ovules. The fusion of wheat egg cells with wheat and S. viridis sperm was conducted using an electro-fusion apparatus. Under suitable osmotic pressure (10% mannitol), calcium concentration of 0.001% (CaCl2·2H2O), and a 30–35 V alternating electric field for 15 s, egg cells and sperm adhered to each other and became arranged in a line. Electroporation of the plasma membrane of egg cells and sperm using a 300–500 V direct-current electric field (45 µs amplitude pulse) caused them to fuse.
Novel NiMoO4-integrated electrode materials were successfully prepared by solvothermal method using Na2MoO4·2H2O and NiSO4·6H2O as main raw materials, water, and ethanol as solvents. The morphology, phase, and structure of the as-prepared materials were characterized by SEM, XRD, Raman, and FT-IR. The electrochemical properties of the materials in supercapacitors were investigated by cyclic voltammetry, constant current charge–discharge, and electrochemical impedance spectroscopy techniques. The effects of volume ratio of water to ethanol (W/E) in solvent on the properties of the product were studied. The results show that the pure phase monoclinic crystal NiMoO4 product can be obtained when the W/E is 2:1. The diameter and length are 0.1–0.3 µm and approximately 3 µm, respectively. As an active material for supercapacitor, the NiMoO4 nanorods material delivered a discharge specific capacitance of 672, 498, and 396 F/g at a current density of 4, 7, and 10 A/g, respectively. The discharge specific capacitance slightly decreased from 815 to 588 F/g with a retention of 72% after 1000 cycles at a current density of 1 A/g. With these superior capacitance properties, the novel NiMoO4 integrated electrode materials could be considered as promising material for supercapacitors.
Toxigenic Clostridium difficile (C. difficile) carriers represent an important source in the transmission of C. difficile infection (CDI) during hospitalisation, but its prevalence and mode in patients with hepatic cirrhosis are not well established. We investigated longitudinal changes in carriage rates and strain types of toxigenic C. difficile from admission to discharge among hepatic cirrhosis patients. Toxigenic C. difficile was detected in 104 (19.8%) of 526 hepatic cirrhosis patients on admission, and the carriage status changed in a portion of patients during hospitalisation. Approximately 56% (58/104) of patients lost the colonisation during their hospital stay. Among the remaining 48 patients who remained positive for toxigenic C. difficile, the numbers of patients who were positive at one, two, three and four isolations were 10 (55.6%), three (16.7%), two (11.1%) and three (16.7%), respectively. Twenty-eight patients retained a particular monophyletic strain at multiple isolations. The genotype most frequently identified was the same as that frequently identified in symptomatic CDI patients. A total of 25% (26/104) of patients were diagnosed with CDI during their hospital stay. Conclusions: Colonisation with toxigenic C. difficile strains occurs frequently in cirrhosis patients and is a risk factor for CDI.
G-protein-coupled receptor 142 (GPR142) belongs to rhodopsin family. GPR142 and GPR119, both Gq-coupled receptors, are expressed in pancreatic β cells of pancreas; their activation eventually leads to triggering of insulin secretion. In this paper, through a systems and synthetic biology approach, the effect of a common hit compound has been investigated in GPR142 and GPR119 pathways. This hit that has the potential to be developed as a lead for nanodrug was obtained through high-throughput virtual screening. The hit compound was further docked with nanoparticles (GOLD, SPION, and CeO2). The probable effect of this potential hit on insulin secretion in type 2 diabetes and its dynamic behavior was explored. Kinetic simulation was performed for cross-validation of its role in both the pathways. This study opens up a probable avenue in therapy of type 2 diabetes through regulation of GPR142 and GPR119 receptors. The biological circuit constructed may further have an application as a modulator to control the up- and downregulation of the biochemical pathway and can be implemented as sensors or nanochips for therapy.
We summarize the findings from an interlaboratory study conducted between ten international research groups and investigate the use of the commonly used maximum separation distance and local concentration thresholding methods for solute clustering quantification. The study objectives are: to bring clarity to the range of applicability of the methods; identify existing and/or needed modifications; and interpretation of past published data. Participants collected experimental data from a proton-irradiated 304 stainless steel and analyzed Cu-rich and Ni–Si rich clusters. The datasets were also analyzed by one researcher to clarify variability originating from different operators. The Cu distribution fulfills the ideal requirements of the maximum separation method (MSM), namely a dilute matrix Cu concentration and concentrated Cu clusters. This enabled a relatively tight distribution of the cluster number density among the participants. By contrast, the group analysis of the Ni–Si rich clusters by the MSM was complicated by a high Ni matrix concentration and by the presence of Si-decorated dislocations, leading to larger variability among researchers. While local concentration filtering could, in principle, tighten the results, the cluster identification step inevitably maintained a high scatter. Recommendations regarding reporting, selection of analysis method, and expected variability when interpreting published data are discussed.
Normal odd-chain SFA (OCSFA), particularly tridecanoic acid (n-13 : 0), pentadecanoic acid (n-15 : 0) and heptadecanoic acid (n-17 : 0), are normal components of dairy products, beef and seafood. The ratio of n-15 : 0:n-17 : 0 in ruminant foods (dairy products and beef) is 2:1, while in seafood and human tissues it is 1:2, and their appearance in plasma is often used as a marker for ruminant fat intake. Human elongases encoded by elongation of very long-chain fatty acid (ELOVL)1, ELOVL3, ELOVL6 and ELOVL7 catalyse biosynthesis of the dominant even-chain SFA; however, there are no reports of elongase function on OCSFA. ELOVL transfected MCF7 cells were treated with n-13 : 0, n-15 : 0 or n-17 : 0 (80 µm) and products analysed. ELOVL6 catalysed elongation of n-13 : 0→n-15 : 0 and n-15 : 0→n-17 : 0; and ELOVL7 had modest activity toward n-15 : 0 (n-15 : 0→n-17 : 0). No elongation activity was detected for n-17 : 0→n-19 : 0. Our data expand ELOVL specificity to OCSFA, providing the first molecular evidence demonstrating ELOVL6 as the major elongase acting on OCSFA n-13 : 0 and n-15 : 0 fatty acids. Studies of food intake relying on OCSFA as a biomarker should consider endogenous human metabolism when relying on OCSFA ratios to indicate specific food intake.
The aim of this study was to investigate the in vivo degradation mechanism and the mechanical properties of poly(lactide-co-glycolide)/beta-tricalcium phosphate (PLGA/β-TCP) composite anchors. Anchors composed of PLGA and β-TCP were implanted in the dorsal subcutaneous tissue of beagle dogs for 6, 12, 16, and 26 weeks. The degradation of the materials was evaluated by measuring the changes in thermal behavior, crystallinity, and mechanical properties. Scanning electron microscope (SEM) was used to observe the surface and longitudinal section of the material. The evaluation of mechanical strength retention and degradation properties suggest that the addition of β-TCP particles efficiently enhances their mechanical properties and thermal characteristics and delays their degradation rate. By analyzing the results of SEM, X-ray diffraction, and differential scanning calorimetry, we can infer that after 12 weeks, the connection between β-TCP and PLGA becomes less compact, which accelerates the decline of mechanical strength.
Two phases of diabase-sill-forming magmatism are recorded within the Badu anticline where magmas were emplaced into upper Palaeozoic carbonates and clastic rocks of the Youjiang fold-and-thrust belt in the SW South China Block, China. Zircons from these diabase units yield weighted mean U–Pb ages of 249.2±2.0 Ma and 187.1±3.3 Ma, and magmatic oxygen fugacity values from ‒20 to ‒6 (average of ‒12, equating to FMQ +5) and ‒20 to ‒10 (average of ‒15, equating to FMQ +2), respectively. These data indicate that the sills were emplaced during Early Triassic and Early Jurassic times. The discovery of c. 250 Ma mafic magmatism in this area was probably related to post-flood-basalt extension associated with the Emeishan mantle plume or rollback of the subducting Palaeo-Tethys slab. The c. 190 Ma diabase sills indicate that the southwestern South China Block records Early Jurassic mafic magmatism and lithospheric extension that was likely associated with a transition from post-collisional to within-plate tectonic regimes. The emplacement of diabase intrusions at depth may have driven hydrothermal systems, enabling the mobilization of elements from sedimentary rocks and causing the formation of a giant epigenetic metallogenic domain. The results indicate that high-oxygen-fugacity materials within basement rocks caused crustal contamination of the magmas, contributing to the wide range of oxygen fugacity conditions recorded by the Au-bearing Badu diabase. In addition, data from inherited xenocrystic zircons within the Badu diabase and detrital zircons from basement rocks suggest that the Neoproterozoic Jiangshao suture extends to the south of the Badu anticline.
Monosized spherical Cu–20% Sn (wt%) alloy particles with diameter ranging from 70.6 to 334.0 μm were prepared by the pulsated orifice ejection method (termed “POEM”). Fully dense without pores and bulk inclusions, the cross-sectional micrographs of the spherical alloy particles indicate an even distribution of Cu and Sn. These spherical Cu–Sn alloy particles exhibit a good spherical shape and a narrow size distribution, suggesting that the liquid Cu–Sn alloy can completely break the balance between the surface tension and the liquid static pressure in the crucible micropores and accurately control the volume of the droplets. Furthermore, the cooling rate of spherical Cu–20% Sn alloy particles is estimated by a Newton’s cooling model. The cooling rate of the Cu–20% Sn alloy particle decreases gradually with the particle diameter increasing. Smaller particles have higher cooling rates and when the particle diameter is less than 70 μm, the cooling rate of particles can reach more than 3.3 × 104 K/s. The secondary dendrite arm spacing has strong dependence on particle diameter which increases gradually with the increase of particle diameter. The results demonstrate that POEM is an effective route for fabrication of high-quality monosized Cu–20% Sn alloy particles.
The lichen family Ophioparmaceae contains three genera: Boreoplaca, Hypocenomyce and Ophioparma. The genus Hypocenomyce is reported here for the first time for China, being represented by the species Hypocenomyce scalaris which is distributed in south-western China. For the genus Ophioparma, one new species is described in this paper, namely Ophioparma pruinosa Li S. Wang & Y. Y. Zhang sp. nov., which is characterized by a pruinose thallus and the presence of usnic acid. Ophioparma araucariae is also reported as new for the Chinese lichen biota. Previous reports of O. lapponica in China are recognized as misidentifications of O. ventosa. Descriptions, keys and phylograms are provided for these species.
Despite recent interest in community-based screening programs to detect undiagnosed cognitive disorder, little is known about whether screening leads to further diagnostic evaluation, or the effects of such programs in terms of actual changes in patient or caregiver behavior. This study followed up informants of older adults (i.e. caregivers of patients who completed informant-based screening regarding the patient) following participation in a study screening for undiagnosed memory problems, to explore uptake of further diagnostic evaluation or treatment, advance planning or preparations, lifestyle changes, medication adherence, and use of support services.
A total of 140 informants of older adult patients were surveyed four to fifteen months following participation in a cognitive screening study. The informants were interviewed with a study-specific survey about cognitive assessment, advance planning, lifestyle changes, and use of support services and general medication adherence.
A minority of patients and informants had engaged in advance planning or made relevant lifestyle changes following cognitive screening. Those assessed as being at higher risk of memory problems were more likely to have attended a full diagnostic evaluation, engaged in support services and experienced medication adherence difficulties.
Only a small proportion of patients participating in cognitive screening subsequently engaged in diagnostic evaluation, advance planning, or lifestyle changes. However, those with higher risk of cognitive impairment were generally more likely to take some action following cognitive screening. Those at higher risk were also more vulnerable due to greater difficulties with medication adherence.
Numerical simulations are used to investigate the hydrodynamic benefits of body–fin and fin–fin interactions in a fish model in carangiform swimming. The geometry and kinematics of the model are reconstructed in three-dimensions from high-speed videos of a live fish, Crevalle Jack (Caranx hippos), during steady swimming. The simulations employ an immersed-boundary-method-based incompressible Navier–Stokes flow solver that allows us to quantitatively characterize the propulsive performance of the fish median fins (the dorsal and the anal fins) and the caudal fin using three-dimensional full body simulations. This includes a detailed analysis of associated performance enhancement mechanisms and their connection to the vortex dynamics. Comparisons are made using three different models containing different combinations of the fish body and fins to provide insights into the force production. The results indicate that the fish produces high performance propulsion by utilizing complex interactions among the fins and the body. By connecting the vortex dynamics and surface force distribution, it is found that the leading-edge vortices produced by the caudal fin are associated with most of the thrust production in this fish model. These vortices could be strengthened by the vorticity capture from the vortices generated by the posterior body during undulatory motion. Meanwhile, the pressure difference between the two sides of posterior body resulting from the posterior body vortices (PBVs) helps with the alleviation of the body drag. The appearance of the median fins in the posterior region further strengthens the PBVs and caudal-fin wake capture mechanism. This work provides new physical insights into how body–fin and fin–fin interactions enhance thrust production in swimming fishes, and emphasizes that movements of both the body and fins contribute to overall swimming performance in fish locomotion.
The description of the gravitational field at the surface of the Earth requires two quantities: the absolute value of the gravitational acceleration and the gravitational direction (deviation from vertical direction). At present, the various gravimeters measure the former quantity, and there is no effective instrument for monitoring the latter. This shortcoming seriously affects the comprehension and further knowledge of the gravitational field.
TiO2 nanotubes have been demonstrated with promising future in photoelectrocatalytic (PEC)_ applications and deposition of Pt nanoparticles on TiO2 has been widely used to enhance their PEC activities. However, those Pt nanoparticles are normally randomly deposited on the surface of TiO2 nanotubes. Selective deposition of Pt nanoparticles is important to achieve better charge separation. In this study, we reported an electrochemical activation step to prepare TiO2 nanotubes deposited with Pt nanoparticles on their open ends. The “activation step” played a key role in achieving a clean surface of the TiO2 nanotubes, thus ensuring the uniform growth of Pt nanoparticles and efficient photogenerated electrons transportation. The Pt-A-TiO2 films have photocatalytic activities in hydrogen generation and methyl orange degradation with a high hydrogen generation rate of 0.74 mL/h/cm2, three times that of the pure TiO2 nanotubes (0.24 mL/h/cm2). Thus, this study demonstrated an effective method for improving the performance of Pt/TiO2 photocatalyst.
The new processing method of spark plasma sintering (SPS) followed by hot extrusion was developed to produce Mg–1Al–xCNTs composites. Microstructural characterization revealed that the reinforcement particles were distributed uniformly in Mg matrix. The results of mechanical properties indicated a fact that compared with monolithic Mg, all Mg–1Al–xCNTs composites, especially the Mg–1Al–0.15CNTs composite, fabricated by SPS followed by hot extrusion exhibited better tensile and compressive properties. Under tension, Mg–1Al–0.15CNTs composite exhibited higher 0.2% tensile yield strength (TYS) (157 MPa versus 98 MPa, increased by ∼60%) and ultimate tensile strength (271 MPa versus 188 MPa, increased by ∼44%) than monolithic Mg. In compression, Mg–1Al–0.15CNTs composite also obtained a great enhancement in 0.2% compressive yield strength (118 MPa versus 81 MPa, increased by ∼46%) and ultimate compressive strength (321 MPa versus 255 MPa, increased by ∼26%) compared to monolithic Mg. Meanwhile, Mg–1Al–0.15CNTs composite maintained a high tensile failure strain of ∼8.8% and a high compressive failure strain of ∼17.9%.
In traditional antenna design, metal components are not placed in the central part of the antenna as they change the characteristics of near field radiation. However, we show that placing a metal ring in the centre of the strip lines, which connect the ends of folded high-frequency dipoles, does not damage the performance of the feed. Instead it significantly improves the voltage standing wave ratio of the feed whilst other performance indicators are not compromised. Thus, our findings show an excellent way of improving the wide band feed. Based on this foundation, a new circularly polarised feed for operation between 0.4 to 2 GHz is introduced for the Chinese Spectral Radioheliograph in this paper. The issue of a feed impedance matching network is investigated. By optimising the impedance matching, the performance of the feed is enhanced with respect to the previous realisations of the Eleven feed. The simulation and experimental results show that the gain of the feed is about 10 dBi, and the VSWR is less than 2:1. In addition, the feed has a low axial ratio, fixed phase centre location, and constant beam width in the range of 0.4 to 2 GHz.
Cerebral small vessel disease (SVD) is the common cause of cognitive decline in the old population. MRI can be used to clarify its mechanisms. However, the surrogate markers of MRI for early cognitive impairment in SVD remain uncertain to date. We investigated the cognitive impacts of cerebral microbleeds (CMBs), diffusion tensor imaging (DTI), and brain volumetric measurements in a cohort of post-stroke non-dementia SVD patients.
Fifty five non-dementia SVD patients were consecutively recruited and categorized into two groups as no cognitive impairment (NCI) (n = 23) or vascular mild cognitive impairment (VaMCI) (n = 32). Detailed neuropsychological assessment and multimodal MRI were completed.
The two groups differed significantly on Z scores of all cognitive domains (all p < 0.01) except for the language. There were more patients with hypertension (p = 0.038) or depression (p = 0.019) in the VaMCI than those in the NCI group. Multiple regression analysis of cognition showed periventricular mean diffusivity (MD) (β = −0.457, p < 0.01) and deep CMBs numbers (β = −0.352, p < 0.01) as the predictors of attention/executive function, which explained 45.2% of the total variance. Periventricular MD was the independent predictor for either memory (β = −0.314, p < 0.05) or visuo-spatial function (β = −0.375, p < 0.01); however, only small proportion of variance could be accounted for (9.8% and 12.4%, respectively). Language was not found to be correlated with any of the MRI parameters. No correlation was found between brain atrophic indices and any of the cognitive measures.
Arteriosclerotic CMBs and periventricular white matter disintegrity seem to be independent MRI surrogated markers in the early stage of cognitive impairment in SVD.
Much can be learned from terrestrial planets that appear to have had the potential to be habitable, but failed to realize that potential. Mars shows evidence of a once hospitable surface environment. The reasons for its current state, and in particular its thin atmosphere and dry surface, are of great interest for what they can tell us about habitable zone planet outcomes. A main goal of the MAVEN mission is to observe Mars’ atmosphere responses to solar and space weather influences, and in particular atmosphere escape related to space weather ‘storms’ caused by interplanetary coronal mass ejections (ICMEs). Numerical experiments with a data-validated MHD model suggest how the effects of an observed moderately strong ICME compare to what happens during a more extreme event. The results suggest the kinds of solar and space weather conditions that can have evolutionary importance at a planet like Mars.