To explore the relationship between charge characteristics of rice roots and aluminum (Al) tolerance of rice, roots of 47 different rice genotypes were obtained by hydroponic experiment. The zeta ...potentials of roots were determined by streaming potential method, and the Al tolerance and the functional groups of rice were measured by relative root elongation and infrared spectroscopy (ATR-FTIR), respectively. The exchangeable, complexed and precipitated Al(III) sorbed on the root surface of rice was extracted with 1 mol L−1 KNO3, 0.05 mol L−1 EDTA-2Na and 0.01 mol L−1 HCl, respectively. There was a significant correlation between the zeta potentials and the relative elongation of rice roots, indicating that the zeta potentials of rice roots could be used to characterize rice tolerance to Al toxicity. Twelve Al-tolerant rice varieties, 25 medium Al-tolerant rice varieties, and 10 Al-sensitive rice varieties were obtained. The Al-tolerant rice varieties sorbed less complexed Al(III) and total Al(III) because there was lower negative charge on their roots compared to less tolerant genotypes. A correlation analysis showed that there were significant negative correlations between the zeta potential, relative root elongation, and the total Al(III) sorption capacity of the roots, which further confirmed the reliability of using the root zeta potential to characterize rice tolerance to Al toxicity. The results of this paper provide a new method for screening Al-tolerant rice varieties.
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•Al-tolerant rice roots carried less negative charges than Al-sensitive rice vroots.•Relative root elongation for Al-tolerant rice is greater than Al-sensitive rice.•Zeta potential of rice roots affected the tolerance of rice to Al toxicity.•Rice root zeta potential can be used to characterize rice tolerance to Al toxicity.
Ideal hydrogel fibers with high toughness and environmental tolerance are indispensable for their long-term application in flexible electronics as actuating and sensing elements. However, current ...hydrogel fibers exhibit poor mechanical properties and environmental instability due to their intrinsically weak molecular (chain) interactions. Inspired by the multilevel adjustment of spider silk network structure by ions, bionic hydrogel fibers with elaborated ionic crosslinking and crystalline domains are constructed. Bionic hydrogel fibers show a toughness of 162.25 ± 21.99 megajoules per cubic meter, comparable to that of spider silks. The demonstrated bionic structural engineering strategy can be generalized to other polymers and inorganic salts for fabricating hydrogel fibers with broadly tunable mechanical properties. In addition, the introduction of inorganic salt/glycerol/water ternary solvent during constructing bionic structures endows hydrogel fibers with anti-freezing, water retention, and self-regeneration properties. This work provides ideas to fabricate hydrogel fibers with high mechanical properties and stability for flexible electronics.
Peripheral nerve injury (PNI) is common and, unlike damage to the central nervous system injured nerves can effectively regenerate depending on the location and severity of injury. Peripheral ...myelinating glia, Schwann cells (SCs), interact with various cells in and around the injury site and are important for debris elimination, repair, and nerve regeneration. Following PNI, Wallerian degeneration of the distal stump is rapidly initiated by degeneration of damaged axons followed by morphologic changes in SCs and the recruitment of circulating macrophages. Interaction with fibroblasts from the injured nerve microenvironment also plays a role in nerve repair. The replication and migration of injury-induced dedifferentiated SCs are also important in repairing the nerve. In particular, SC migration stimulates axonal regeneration and subsequent myelination of regenerated nerve fibers. This mobility increases SC interactions with other cells in the nerve and the exogenous environment, which influence SC behavior post-injury. Following PNI, SCs directly and indirectly interact with other SCs, fibroblasts, and macrophages. In addition, the inter- and intracellular mechanisms that underlie morphological and functional changes in SCs following PNI still require further research to explain known phenomena and less understood cell-specific roles in the repair of the injured peripheral nerve. This review provides a basic assessment of SC function post-PNI, as well as a more comprehensive evaluation of the literature concerning the SC interactions with macrophages and fibroblasts that can influence SC behavior and, ultimately, repair of the injured nerve.
Four air-stable cyclometalated half-sandwich iridium complexes 1–4 with C,N-donor Schiff base ligands were prepared through C–H activation in moderate-to-good yields. These complexes have been well ...characterized, and their exact structure was elaborated on by single-crystal X-ray analysis. The iridium(III) complexes 1–4 showed good catalytic activity in the imine synthesis under open-flask conditions (air as the oxidant) from primary amine oxidative homocoupling, secondary amine dehydrogenation, and the cross-coupling reaction of amine and alcohol. Substituents bonded on the ligands of the iridium complexes displayed little effect on the catalytic efficiency. The stability and good catalytic efficiency of the iridium catalysts, mild reaction conditions, and substrate universality showed their potential application in industrial production.
•Seven acoustic indices are tested using three controlled computational experiments.•Three acoustic dimensions of bird vocalizations affect acoustic indices’ performance.•H, ADI, and AEI show ...moderate correlations with avian species richness.•ADI is relatively more robust regarding bird species richness surveys.
Passive acoustic monitoring of biotic sounds is increasingly popular in conservation biology. Among vocalizing animals, birds are most frequently studied and multiple acoustic indices have been proposed for rapid acoustic assessment of avian diversity. Preliminary results suggest that several indices can be used as proxies for bird species richness, however it is still unclear to what extent different conditions of bird vocalizations affect the relationship between indices and bird species richness – should it matter if the bird vocalizations contain different sound unit shapes, or if the frequency of vocalization occurrence differs, or if the vocalizations are made with various intensities?
In this work, seven commonly used acoustic indices were tested using three controlled computational experiments with real-world recordings to provide an objective measure of each index’s performance for answering the aforementioned questions. In the experiments, different options of sound unit shape and frequency of vocalization occurrence were precisely controlled and intensity variations were expressed as different signal-to-noise ratios (SNR) of the vocalizations.
The first experiment showed that three indices (the acoustic entropy index (H), acoustic diversity index (ADI), and acoustic evenness index (AEI)) performed better than the other four, showing moderate correlations with avian species richness. The second experiment revealed that ADI for each sound unit shape tended towards a constant value with increasing frequency of vocalization occurrence while the influence from frequency of vocalization occurrence on H and AEI varied with different sound unit shape options. Our third experiment showed that the vocalization intensity affected the values of these three indices while the performance disparity among different sound unit shapes for only ADI explicitly appeared a decreasing tendency with increasing vocalization intensities. We conclude that ADI, among the tested indices, is relatively more robust with regard to bird species richness surveys when sound unit shape, frequency of vocalization occurrence, and vocalization intensity are considered. Meanwhile, since multiple indices are usually applied together to provide a comprehensive observation, the above acoustic dimensions should be taken into account especially in comparative research of different bird communities.
Purpose
This study aimed to apply a newly developed semi-automatic phantom-less QCT (PL-QCT) to measure proximal humerus trabecular bone density based on chest CT and verify its accuracy and ...precision.
Methods
Subcutaneous fat of the shoulder joint and trapezius muscle were used as calibration references for PL-QCT BMD measurement. A self-developed algorithm based on a convolution map was utilized in PL-QCT for semi-automatic BMD measurements. CT values of ROIs used in PL-QCT measurements were directly used for phantom-based quantitative computed tomography (PB-QCT) BMD assessment. The study included 376 proximal humerus for comparison between PB-QCT and PL-QCT. Two sports medicine doctors measured the proximal humerus with PB-QCT and PL-QCT without knowing each other’s results. Among them, 100 proximal humerus were included in the inter-operative and intra-operative BMD measurements for evaluating the repeatability and reproducibility of PL-QCT and PB-QCT.
Results
A total of 188 patients with 376 shoulders were involved in this study. The consistency analysis indicated that the average bias between proximal humerus BMDs measured by PB-QCT and PL-QCT was 1.0 mg/cc (agreement range – 9.4 to 11.4;
P
> 0.05, no significant difference). Regression analysis between PB-QCT and PL-QCT indicated a good correlation (
R
-square is 0.9723). Short-term repeatability and reproducibility of proximal humerus BMDs measured by PB-QCT (CV: 5.10% and 3.41%) were slightly better than those of PL-QCT (CV: 6.17% and 5.64%).
Conclusions
We evaluated the bone quality of the proximal humeral using chest CT through the semi-automatic PL-QCT system for the first time. Comparison between it and PB-QCT indicated that it could be a reliable shoulder BMD assessment tool with acceptable accuracy and precision.
Summary
This study developed and verify a semi-automatic PL-QCT for assessment of proximal humeral bone density based on CT to assist in the assessment of proximal humeral osteoporosis and development of individualized treatment plans for shoulders.
The effect of dust particle size on the distribution and bioaccessibility of flame retardants (FRs) in indoor dust remains unclear. In this study, we analyzed 20 FRs (including 6 organophosphate ...flame retardants (OPFRs), 8 polybrominated diphenyl ethers (PBDEs), 4 novel brominated flame retardants (NBFRs), and 2 dechlorane plus (DPs)) in composite dust samples from offices, public microenvironments (PME), and cars in Nanjing, China. Each composite sample (one per microenvironment) was separated into 6 size fractions (F1–F6: 200–2000µm, 150–200µm, 100–150µm, 63–100µm, 43–63µm, and <43µm). FRs concentrations were the highest in car dust, being 16 and 6 times higher than those in offices and PME. The distribution of FRs in different size fractions was Kow-dependent and affected by surface area (Log Kow=1–4), total organic carbon (Log Kow=4–9), and FR migration pathways into dust (Log Kow>9). Bioaccessibility of FRs was measured by the physiologically-based extraction test, with OPFR bioaccessibility being 1.8–82% while bioaccessible PBDEs, NBFRs, and DPs were under detection limits due to their high hydrophobicity. The OPFR bioaccessibility in 200–2000µm fraction was significantly higher than that of <43µm fraction, but with no difference among the other four fractions. Risk assessment was performed for the most abundant OPFR-tris(2-chloroethyl) phosphate. The average daily dose (ADD) values were the highest for the <43µm fraction for all three types of dust using total concentrations, but no consistent trend was found among the three types of dust if based on bioaccessible concentrations. Our results indicated that dust size impacted human exposure estimation of FRs due to their variability in distribution and bioaccessibility among different fractions. For future risk assessment, size selection for dust sampling should be standardized and bioaccessibility of FRs should not be overlooked.
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•Indoor dust from office/public microenvironments/cars were separated into 6 size fractions.•FR distribution was dependent on Kow/dust surface area/TOC/FR migration pathway.•OPFR bioaccessibility was 1.8–82%, bioaccessible PBDEs/NBFRs/DPs were < detection limit.•Human exposure to FR was dependent on dust particle size and bioaccessibility.
Lipomas are common benign tumors, constituting 16% of soft tissue mesenchymal tumors. They usually occur under the skin or in the large muscles of the thigh, shoulder, or upper arm. There are few ...reported cases of lipomas located in the forearm and hand muscles, accounting for less than 1% of all lipomas.
A 47-year old man presented with a history of swelling and accompanying pain in the left wrist for 2 years.
The patient was diagnosed with intramuscular lipoma in the pronator quadratus.
The mass was resected completely with wide-awake technique.
The patient was followed up for 2 years with no recurrence. The symptoms of swelling and pain resolved within 3 weeks post-surgery, and there was no clear abnormality in wrist and finger movement and sensation. A satisfactory outcome was achieved.
Intramuscular lipoma in the pronator quadratus is a rare benign tumor which should be distinguished from malignant tumors. Especially for patients with carpal tunnel syndrome presenting with wrist swelling, ultrasound, computed tomography, or magnetic resonance imaging can be used to assess deep tissue masses.
As one type of effective earthquake-resisting structural systems, buckling-restrained braced frames are expected to provide good seismic performance through significant plastic yielding to dissipate ...earthquake energy. This plastic deformation can cause significant structural damage and residual drift, leading to high retrofitting cost or even demolishment of structures after strong earthquakes. As a result, development of new systems that can not only dissipate seismic energy, but also possess self-centering ability, becomes necessary. This paper makes use of a newly proposed type of self-centering dual-steel buckling-restrained braces (SC-DBRBs). The SC-DBRB consists of a low-yield-point steel and a high strength steel, in which the low-yield-point steel mainly provides energy dissipation ability, and the high strength steel offers self-centering ability and additional energy dissipation ability during strong earthquakes. Compared with a conventional BRB (CBRB) commonly with a typical bilinear constitutive model, the SC-DBRB has a trilinear hysteretic behavior, leading to early re-yielding of the low-yield-point steel during subsequent strain reversals. This early re-yielding mechanism can greatly mitigate residual deformation of the SC-DBRB. In this paper, the constitutive model of the SC-DBRB is first established, and its correlation with main design parameters is also discussed. To demonstrate the self-centering ability of the SC-DBRB and its effect on post-earthquake performance of structures, a series of six-story and nine-story steel frames were numerically investigated using ABAQUS: unbraced frames, CBRB-equipped frames and SC-DBRB-equipped frames. Time history analysis results show that the SC-DBRB can effectively reduce residual drift.
•A novel self-centering dual-steel buckling restrained brace with a trilinear constitutive model proposed.•Self-centering mechanism is owing to early re-yielding of low-yield-point steel in reversal loading.•High secondary stiffness of the braces leads to small drift ratio of the SC-DBRB frames.•High secondary stiffness of the braces can ensure relatively uniform deformation of the frame.•The self-centering property leads to small residual drift of the SC-DBRB frames.
Bioinformatics is challenged by the fact that traditional analysis tools have difficulty in processing large-scale data from high-throughput sequencing. The open source Apache Hadoop project, which ...adopts the MapReduce framework and a distributed file system, has recently given bioinformatics researchers an opportunity to achieve scalable, efficient and reliable computing performance on Linux clusters and on cloud computing services. In this article, we present MapReduce frame-based applications that can be employed in the next-generation sequencing and other biological domains. In addition, we discuss the challenges faced by this field as well as the future works on parallel computing in bioinformatics.
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