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Reducing the environmental problems caused by nitrogen loss and nitrogen pollution is of great significance. The addition of biochar to soil is a new method for increasing nitrogen interception due to the special structural and physicochemical properties of biochar. The optimal modified biochar was screened out after acid–base modification and batch adsorption test in this paper. And then the effects of different soil and biochar mixing methods on soil physicochemical properties and nitrogen adsorption and retention were explored through soil column leaching test. The results showed that the biochar with a pyrolysis temperature of 700 °C had the best adsorption effect on nitrogen after being modified by 0.1 mol/L HCI, and the adsorption capacity of nitrate nitrogen reached 121.46 mg/g. The adsorption process of ammonia nitrogen and nitrate nitrogen conformed to the Langmuir model and was mainly homogeneous monolayer. After mixing the selected modified biochar with black soil, the pH increased by 4.77%, the content of ammonia nitrogen increased by 4.89%, and the nitrate content increased by 16.62%. In this study, the adsorption effect of biochar on nitrogen in black soil was discussed, so as to explore the optimal use of biochar in soil, which provided some reference basis for the relevant research. [ABSTRACT FROM AUTHOR]

Surface electromyography (sEMG) is commonly used to observe the motor neuronal activity within muscle fibers. However, decoding dexterous body movements from sEMG signals is still quite challenging. In this paper, we present a high-density sEMG (HD-sEMG) signal database that comprises simultaneously recorded sEMG signals of intrinsic and extrinsic hand muscles. Specifically, twenty able-bodied participants performed 12 finger movements under two paces and three arm postures. HD-sEMG signals were recorded with a 64-channel high-density grid placed on the back of hand and an 8-channel armband around the forearm. Also, a data-glove was used to record the finger joint angles. Synchronisation and reproducibility of the data collection from the HD-sEMG and glove sensors were ensured. The collected data samples were further employed for automated recognition of dexterous finger movements. The introduced dataset offers a new perspective to study the synergy between the intrinsic and extrinsic hand muscles during dynamic finger movements. As this dataset was collected from multiple participants, it also provides a resource for exploring generalized models for finger movement decoding. Measurement(s) Electromyography Technology Type(s) Surface Electrode Factor Type(s) hand gesture Sample Characteristic - Organism Homo sapiens Sample Characteristic - Environment human house Sample Characteristic - Location China [ABSTRACT FROM AUTHOR]

Co-doped magnetic Mn3O4 was synthesized by the solvothermal method and adopted as an effective catalyst for the degradation of oxytetracycline (OTC) in water. Synergistic interactions between Co-Mn3O4 and Fe3O4 not only resulted in the enhanced catalytic activity through the activation of peroxymonosulfate (PMS) to degrade OTC but also made Fe3O4/Co-Mn3O4 easy to be separated and recovered from aqueous solution. 94.2% of OTC could be degraded within 60 min at an initial OTC concentration of 10 mg L−1, catalyst dosage of 0.2 g L−1, and PMS concentration of 10 mM. The high efficiency of OTC removal was achieved in a wider pH range of 3.0–10.0. Co (II), Co (III), Fe (II), Fe (III), Mn (II), Mn (III), and Mn (IV) on Fe3O4/Co-Mn3O4 were identified as catalytic sites based on XPS analysis. The free radical quenching experiments showed that O2•− radicals and 1O2 played the main role in the degradation process and the catalytic degradation of OTC involved both free radical and non-free radical reactions. Eventually, the intermediates of OTC degradation were examined, and the possible decomposition pathways were proposed. The excellent catalytic performances of Fe3O4/Co-Mn3O4 came from the fact that the large specific surface area could provide abundant active sites for the activation of PMS and the redistribution of inter-atomic charges accelerated the redox reactions of metal ions. The high degradation efficiency and rate constant of OTC in actual water samples indicated that Fe3O4/Co-Mn3O4 had a good practical application potential. [ABSTRACT FROM AUTHOR]

Rapid and accurate detection of phenolic wastewater from industries has created global concern. Herein, core–shell magnetic cellulose nanocrystal supported MOF (Fe3O4/CNC@ZIF-8) with robust peroxidase-like activity was synthesized with tannic acid as modifier and bridge. The peroxidase-mimic catalytic activity of as-prepared Fe3O4/CNC@ZIF-8 was further investigated using o-phenylenediamine (OPD) as peroxidase substrates in the presence of H2O2. Moreover, the experimental conditions were optimized and the kinetic analysis results showed that Fe3O4/CNC@ZIF-8 had higher affinity towards both the substrate OPD and H2O2 than horseradish peroxidase (HRP). Finally, a phenol colorimetric assay with a linear range of 2–200 µM and a detection limit of 0.316 µM was constructed. The catalytic mechanism of Fe3O4/CNC@ZIF-8 with phenol was further investigated by fluorescence test and the generated ·OH was proved to act a crucial role to produce quinoid radicals. Additionally, the synthesized magnetic material had excellent stability and recyclability and ease to separation. These results suggest that the Fe3O4/CNC@ZIF-8 may be one of the promising candidates as peroxidase mimic for colorimetric detection of phenol. [ABSTRACT FROM AUTHOR]

A sustained release of anti-infection drugs is beneficial for the reduction of required dressing change times and the protection of the granulation tissue against further infection. In this work, the strategy of encapsulating mesoporous SBA-15 particles in a permeable cellulose membrane (CM) was used in the preparation of antibacterial cellulose based composite membranes to depot store and deliver drugs with prolonged anti-microbial drug release characteristics. It was found that SBA-15 with the protection of phosphate buffered saline prefilled in SBA-15 mesoporous channel could resist strong alkali environment during composite membranes preparation and its mesoporous structure remained intact, which was verified by SEM, TEM and BET results. The resultant cellulose based composite membrane containing 30 wt% SBA-15 (denoted as P-CM-SBA (30%)) had achieved 3.6 wt% drug loading and demonstrated the sustained release of chloramphenicol for 250 h, which was resulted from SBA-15/cellulose structure-inducing two-stage release behavior. Strong antibacterial activity of P-CM-SBA (30%) against S. aureus and E. coli. could last 144 h. In addition, the tensile strength, water vapor transmission rate and swelling properties of P-CM-SBA (30%) conformed to the primary requirements of wound dressing materials. Therefore, cellulose based composite membrane with 30 wt% SBA-15 particles possesses the potential for the application of wound healing. [ABSTRACT FROM AUTHOR]

Two rhodamine B-based Schiff bases (RBF, RBC) with different substituent groups (-F and -COOH) have been synthesized. In order to study the sensing properties of two Schiff bases for metal ions, the interaction of Schiff bases with different metal ions was studied over UV-Vis absorption spectra and photofluorescent spectra. The results show that the RBF is a turn-on fluorescent chemosensor for Al3+ ions with being highly selective and sensitive in ethanol. The value of the fluorescence increase factor shows a good linear relationship with the concentration of Al3+ in the range of 1-9 μM with a detection limit of 0.8 μM. Meanwhile, upon addition of Al3+ or Fe3+ ions, the fluorescence intensity of RBC increased significantly (FFe3+FAl3+=0.77). These studies show that, compared with the carboxyl group (-COOH), the introduction of fluorine atoms (-F) to a rhodamine B-based Schiff base can significantly improve selectivity to Al3+. [ABSTRACT FROM AUTHOR]

A new 4,5-diazafluorene-based fluorescent chemosensor has been synthesized by Schiff base condensation of 9,9-bis(3,5-dimethyl-4-aminophenyl)-4,5-diazafluorene with salicylaldehyde. The interaction of Schiff base with different metal ions has been studied over photofluorescent spectra. The results showed that Schiff base exhibited 194-fold enhancements in fluorescence at 465 nm after Zn ions. Such fluorescent responses could be detected by naked eye under UV-lamp. The complex solution ( L-Zn) exhibited reversibility with EDTA. [ABSTRACT FROM AUTHOR]

A simple preparation process for the monodispersed pH-sensitive core-shell magnetic microspheres was carried out consisting of chitosan self-assembled on magnetic iron oxide nanoparticles. Meanwhile, glucoamylase was immobilized as a model enzyme on this carrier of FeO/CS microspheres by ionic adsorption. The morphology, inner structure, and high magnetic sensitivity of the resulting magnetic chitosan microspheres were studied, respectively, with a field emission scanning electron microscope (SEM), transmission electron microscope (TEM), FT-IR spectroscopy, thermogravimetric analysis (TGA), and a vibrating sample magnetometer (VSM). Subsequently, the properties of glucoamylase immobilized on the regenerated supports were also investigated by determining storage stability, pH stability, reusability, magnetic response, and regeneration of supports. The results from characterization and determination remarkably indicated that the immobilized glucoamylase obtained presents excellent storage stability, pH stability, reusability, magnetic response, and regeneration of supports. Therefore, this kind of magnetic FeO/CS microspheres with perfect monodispersity should be an ideal support for enzyme immobilization. [ABSTRACT FROM AUTHOR]

Brain iron deposition has been proposed to play an important role in the pathophysiology of Alzheimer disease (AD). The aim of this study was to investigate the correlation of brain iron accumulation with the severity of cognitive impairment in patients with AD by using quantitative MR relaxation rate R2′ measurements. Fifteen patients with AD, 15 age- and sex-matched healthy controls, and 30 healthy volunteers underwent 1.5T MR multi-echo T2 mapping and T2* mapping for the measurement of transverse relaxation rate R2′ (R2′=R2*−R2). We statistically analyzed the R2′ and iron concentrations of bilateral hippocampus (HP), parietal cortex (PC), frontal white matter (FWM), putamen (PU), caudate nucleus (CN), thalamus (TH), red nucleus (RN), substantia nigra (SN), and dentate nucleus (DN) of the cerebellum for the correlation with the severity of dementia. Two-tailed t-test, Student-Newman-Keuls test (ANOVA) and linear correlation test were used for statistical analysis. In 30 healthy volunteers, the R2′ values of bilateral SN, RN, PU, CN, globus pallidus (GP), TH, and FWM were measured. The correlation with the postmortem iron concentration in normal adults was analyzed in order to establish a formula on the relationship between regional R2′ and brain iron concentration. The iron concentration of regions of interest (ROI) in AD patients and controls was calculated by this formula and its correlation with the severity of AD was analyzed. Regional R2′ was positively correlated with regional brain iron concentration in normal adults ( r=0.977, P<0.01). Iron concentrations in bilateral HP, PC, PU, CN, and DN of patients with AD were significantly higher than those of the controls ( P<0.05); Moreover, the brain iron concentrations, especially in parietal cortex and hippocampus at the early stage of AD, were positively correlated with the severity of patients' cognitive impairment ( P<0.05). The higher the R2′ and iron concentrations were, the more severe the cognitive impairment was. Regional R2′ and iron concentration in parietal cortex and hippocampus were positively correlated with the severity of AD patients' cognitive impairment, indicating that it may be used as a biomarker to evaluate the progression of AD. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the effect of tyrosine kinase Src on Tyrosine 307(Y307) phosphorylation, protein phosphatase 2A (PP2A) activity, and on tau phosphorylation. Specific Src siRNA was transfected into cultured mouse neuroblastoma N2a cells to inhibit the expression of Src protein, and the phosphorylation levels of PP2A Y307 and tau at different sites, as well as PP2A activity were detected at different time points after siRNA transfection. Twelve hours after siRNA transfection, the protein level of Src was dramatically decreased, with decreased PP2A Y307 phosphorylation. However, the total PP2A protein level was also decreased, together with a decreased PP2A activity. Tau was hyperphosphorylated at the Ser198/199/202 sites. Multiple factors may be involved in the cellular regulation of PP2A activity. Inhibiting Src expression could induce inactivation of PP2A and tau hyperphosphorylation. [ABSTRACT FROM AUTHOR]

We previously reported that the injection of okadaic acid (OA) into the Meynert nucleus basalis of rats induced spatial memory deficits. The present study was designed to further explore the underlying mechanisms. We found that the level of acetylcholine (Ach) in the hippocampus significantly decreased 24 h after injection of OA into the Meynert nucleus basalis of rats. Simultaneously, spatial memory deficit, PP-2A inhibition and tau hyperphosphorylation at Ser-198/Ser-199/Ser-202 (Tau-1 epitope) and Ser-396/Ser-404 (PHF-1 epitope) were observed. With the restoration of hippocampus Ach to normal levels at 48 and 72 h after the injection, the spatial memory deficits, PP-2A inhibition and tau hyperphosphorylation were reversed. It is suggested that injection of OA into the Meynert nucleus basalis of rats may impair the hippocampus-dependent spatial memory through damaging the cholinergic projection between the Meynert nucleus basalis and the hippocampus and the selective inhibition of PP-2A and tau hyperphosphorylation may be at least part of the underlying mechanisms. [ABSTRACT FROM AUTHOR]

One of the neuropathological features of Alzheimer’s disease (AD) is the deposition of senile plaques containing β-amyloid (Aβ). There is limited evidence for the treatment to arrest Aβ pathology of AD. In our present study, we tested the effect of coenzyme Q10 (CoQ10), an endogenous antioxidant and a powerful free radical scavenger, on Aβ in the aged transgenic mice overexpressing Alzheimer presenilin 1-L235P (leucine-to-proline mutation at codon 235, 16–17 months old). The treatment by feeding the transgenic mice with CoQ10 for 60 days (1,200 mg kg−1 day−1) partially attenuated Aβ overproduction and intracellular Aβ deposit in the cortex of the transgenic mice compared with the age-matched untreated transgenic mice. Meanwhile, an increased oxidative stress reaction was detected as evidenced by elevated level of malondialdehyde (MDA) and decreased activity of superoxide dismutase (SOD) in the transgenic mice relative to the wild-type mice, and supplementation of CoQ10 partially decreased MDA level and upregulated the activity of SOD. The results indicate that oxidative stress is enhanced in the brain of the transgenic mice, that this enhancement may further promote Aβ42 overproduction in a vicious formation, and that CoQ10 would be beneficial for the therapy of AD. [ABSTRACT FROM AUTHOR]

In Alzheimer’s disease (AD), hyperphosphorylation of tau may be the underlying mechanism for the cytoskeletal abnormalities and neuronal death. It was reported that cyclin-dependent kinase5 (cdk-5) could phosphorylate tau at most AD-related epitopes in vitro. In this study, we investigated the effect of cdk-5 overexpression on tau phosphorylation and spatial memory in rat. We demonstrated that 24 h after transfection into rat hippocampus, cdk-5 was overexpressed and induced a reduced staining with antibody tau-1 and an enhanced staining with antibodies 12e8 and PHF-1, suggesting hyperphosphorylation of tau at Ser199/202, Ser262/356 and Ser396/404 sites. Additionally, the cdk-5 transfected rats showed long latency to find the hidden platform in Morris water maze compared to the control rat. 48 h after transfection, the level of cdk-5 was decreased significantly, and the latency of rats to find the hidden platform was prolonged. It implies that in vivo overexpression of cdk-5 leads to impairment of spatial memory in rat and tau hyperphosphorylation may be the underlying mechanism. [ABSTRACT FROM AUTHOR]

Object handover is one of the fundamental tasks of service robots. This paper focuses on a robot-to-human object handover controller applied to a domestic service robot. People in need often have manual operation constraints caused by different body postures or declined physical functions. The preplanned handover strategy used in previous studies potentially increases their cognitive burden and makes it difficult to meet their needs for flexible real-time control and intuitive interaction. It also remains challenging to deal with sensing and prediction errors, motion planning and coordination. The robot no longer provides assistance after an object is delivered to a preplanned handover location, and the receiver needs to make extra efforts to get the object released. Therefore, inspired by a human study, a handover controller is designed based on a manually guided handover strategy that solve problems from grasp adjustment to object release in dynamic retraction motion. Flexible control and intuitive interaction are enabled through motion with continuous support from the robot. Without additional sensors or modeling learning, changes in motion and energy consumption are taken into account to explore an appropriate release timing. The results of robot-to-human handover experiments and the user studies indicate that the receiver can freely pull an object to a suitable location as desired and smoothly obtain the object’s control to complete a subsequent task using the proposed controller with proper release timing. [ABSTRACT FROM AUTHOR]