Search

Sichuan is the China’s leading producer of loquat, with the largest cultivation area and yield ranked first in China. Loquat is a seasonal fruit highly appreciated by consumers; however, the fruit is prone to browning and lignification after harvest, affecting its storage quality. The effects of L-Cysteine (L-Cys, 0.01, 0.05, 0.1, 0.2%) and γ-aminobutyric acid (GABA, 0.025, 0.05, 0.075, 0.1%) on the sensory quality and antioxidant activity of loquat fruit during cold storage at 4 °C for 35 days and simulated shelf life for 5 days were investigated. The results showed that after 40 days of storage, compared with the control, 0.05% L-Cys and 0.05% GABA treatment of ‘Zaozhong No. 6’ loquat fruit effectively reduced the weight loss rate, browning index, decay index, respiratory rate, firmness, and lignin content and slowed the decreases in total soluble solids, soluble sugar, titratable acidityand vitamin C contents. The application of 0.05% L-Cys and 0.05% GABA significantly increased the contents of total phenols, total flavonoids, flavanols, and carotenoids; delayed the increase of relative electric conductivity, MDA, POD, and PPO activities; and significantly enhanced the activities of SOD and CAT, DPPH free radical scavenging ability, and FRAP, thereby improving antioxidant capacity. In summary, 0.05% L-Cys and 0.05% GABA treatment promotes the quality of loquat fruit after 40 days of storage, and significantly enhances antioxidant capacity, thus delaying senescence after harvest.

A modified gel polymer electrolyte (GPE) with boron nitride (BN) additive was designed to boost the electrochemical performance of rechargeable lithium metal battery, which consists of Li-rich layered cathode and possesses a high energy density. BN, electron insulator and ion conductor, has excellent thermodynamic and electrochemical stability. BN particles were well dispersed in polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) polymer matrices and thus substantially enhanced the electrochemical and physical properties of the GPEs. With only 0.5 wt% BN additive, it remarkably improved the mechanical modulus and ionic conductivity (to 4.1 × 10−4 S∙cm−2) of GPEs, which was beneficial for suppressing lithium dendrite formation and fast ion transportation, respectively, thereby enabling high-performance lithium metal batteries with ultra-long cycle life and high safety at ambient temperature (25 °C) and high temperature (55 °C).

Partially reduced and nitrogen-doped graphene oxides (PRNGs) were prepared through a one-step hydrothermal method with graphene oxide as raw material and phenylethylamine as reducing-doping agents. Benefiting from nitrogen- and oxygen-containing functional groups, interconnected 3D porous networks and high specific surface area, the as-prepared samples demonstrate good electrochemical performances. Particularly, the PRNG-10 electrodes in the wet state show an enhanced gravimetric and volumetric specific capacitance (264.1 F g−1 and 211.3 F cm−3), good rate capability and excellent cycle stability (101.85% of the initial capacitance after 10000 cycles) in 6 M KOH electrolyte.

We fabricate a novel 3D N-doped graphene/silicon composite for lithium-ion battery anodes, with Si nanoparticles uniformly dispersed and thoroughly embedded in the N-doped graphene matrix. The favorable structure of the composite results in a BET surface area and an average mesopore diameter of 189.2 m2 g−1 and 3.82 nm, respectively. The composite delivers reversible capacities as high as 1132 mA h g−1 after 100 cycles under a current of 5 A g−1 and 1017 mA h g−1 after 200 cycles at 1 A g−1, and exhibits an improved rate capability. The present approach shows promise for the preparation of other high-performance anode materials for lithium-ion batteries.

A novel method for scalable fabricating porous silicon/carbon composite as anode material for lithium-ion batteries is reported in this article. Diatomite is used as a raw material for synthesis of porous silicon via combining mechanical ball milling with magnesiothermic reduction method, employing NaCl as a heat scavenger. The resulting silicon maintains the porous structure of diatomite, with large specific surface area of 288.5 m2 g−1 and average pore size of 9.6 nm. The C@pSi-I composite delivers improved cycling stability and good rate capability. A discharge capacity of 1116.7 mA h g−1 at current density of 200 mA g−1 is achieved after 200 cycles, which will be beneficial to the scalable synthesis of porous silicon materials for the next generation lithium-ion batteries.

A Si-rGO/NCT composite, in which Si nanoparticles (SiNPs) are enwrapped with N-doped carbon and combine with N-doped graphene and CNTs as conductive matrices synthesized by simple solution-mixing and carbonization process with pyrolyzing melamine formaldehyde resin (MFR) is developed as a promising candidate anode material for lithium ion batteries (LIBs). The N-doped carbon outside SiNPs can not only improve the electrical conductivity of the composite, but also buffer the stress causing by huge volume change of SiNPs during the lithiation/delithiation process. The Si-rGO/NCT composite exhibits high specific capacity and good cycling stability (892.3 mAh g−1 at 100 mA g−1 up to 100 cycles), as well as improved rate capability. This approach provides a very facile route to obtain silicon-based anode materials.

In this work, the 3D macroscopic graphene hydrogels (MGHs) with a high capacitor performance were easily prepared by a one-step hydrothermal method from graphene oxide (GO) dispersions. A very small amount of 1,4-butanediamine was employed to realize the partial reduction of GO, modification of the 3D structure of MGHs, and nitrogen doping of graphene, at the same time. The synthesized MGH-6 sample in the wet state exhibit a high specific capacitance of 268.8 Fg −1 at 0.3 A g −1 in 6 M KOH electrolyte, and this capacitance can be maintained for 84.9% even as the discharging current density was increased up to 10 A g −1 . The MGH-6 sample also shows good cycle stability along with a 1.03% increase of its initial specific capacitance after 10000 cycles at current density of 10 Ag −1 . These remarkable properties are ascribed to the both nitrogen- and oxygen-containing functional groups, modified macroporous 3D framework, and the high specific surface area of the graphene. Combining with the economical and easy path toward mass production, the present MGH-6 can be expected as a promising candidate for high-performance supercapacitors.

Electrochemical energy devices including batteries, supercapacitors and fuel cells are reliable and practical technologies in which carbon-based electrode materials play critical roles in enhancing performance. Because of this, the source and synthesis of these carbon-based materials have been extensively explored and developed. And of the various carbon-based materials, biomass-derived carbon materials and corresponding composites have been recognized to be capable of delivering high capacities, enhanced rate performances and prolonged cycling stabilities in both lithium-ion batteries and supercapacitors as partially induced through a combination of favorable pore structures and heteroatom-doping. In addition, biomass-derived carbon materials can provide significantly enhanced activity and stability for cathode oxygen reduction reactions if used as catalyst support materials in polymer electrolyte membrane fuel cells. Based on this, this review will provide a comprehensive assessment as well as critical analysis and systematic comparison of biomass-derived carbon materials and corresponding composites as electrode materials in various electrochemical energy devices based on recent progresses in research and development. In addition, related technical challenges are analyzed and possible research directions are proposed to further development for practical application.

Although cation-deficient nanomaterials, especially one-dimensional (1D) nanowires, have demonstrated to be feasible in electrochemical energy storage as promising electrode materials, the effects of cation defects on charge transfer and electrode performance are not fully explored and understood. In this paper, the cation defects are generated in the as-prepared gallium nitride (GaN) via a cost-effective plasma process, serving as the reversible active sites to boost electrochemical performance by simultaneously promoting electrical conductivity and charge transfer. Several techniques, including XRD, TEM, XANES, cyclic voltammetry, Electrochemical impedance spectroscopy, etc., are used to characterize and understand the material morphology, structure and composition as well as the electrochemical properties. Results show that the cation-deficient GaN nanowires have abundant nanochannels, which can facilitate the rapid ionic transfer. The anode of such a material cation can deliver much higher capacities of 746.5 mAh g−1 at 0.1 A g−1 after 100 cycles and 370.2 mAh g−1 at 10 A g−1 after 1000 cycles, respectively. Density functional theory (DFT) calculations prove that benefited from the unique self-supported 1D architecture and cation defects, the local atomic arrangement and electronic structure can be tuned to significantly increase the electrical conductivity and charge transfer efficiency and subsequently boost lithium-ion storage for lithium-ion batteries. This strategy provides an accessible approach to utilize cation-defect nanomaterials for advanced electrochemical energy applications.

Cu nanoparticles of well-defined size and stability were synthesized with the aid of a double-template method. The templates consisted of sodium dodecyl sulfate (SDS) aggregates combined with and wrapped by poly(vinylpyrrolidone) (PVP) chains. Copper sulfate was reduced within the templates resulting in multicrystalline Cu nanoparticles. The size of the particles was uniform. They were capped by PVP–SDS complexes and the shape turned out to be non-spherical. PVP used in the experiments has an average molecular weight of 40,000. In this case, the particle dimensions were essentially determined by the chosen concentration of SDS in the reaction solution. No oxidation of the as-grown copper particles was detected even in the absence of inert gas protection during the synthesis process. When exposed to air at room temperature, Cu nanoparticles capped by PVP–SDS complexes showed much better resistance to oxidation than those without the capping agents. Furthermore, the steric and screening effect of the capping agents permitted the preparation of uniform colloidal dispersions stable over months. The material obtained by this double-template method was found to be very sensitive to the synthesis temperature. At synthesis temperatures above 40 °C, CuO instead of Cu was obtained.

Abnormalities of external anal sphincter electromyography (EAS-EMG) characterize multiple system atrophy (MSA) and focal cauda equina or conus medullaris lesions. This study is designed to determine whether and how diabetic polyneuropathy (DPN) affects EAS as compared to the abnormalities seen in MSA.We conducted multi-motor unit potential (MUP) analysis of EAS in 22 healthy controls, 32 diabetes mellitus (DM) patients without neuropathy, 38 DPN patients, and 68 MSA patients.DPN patients had a significant (P 0.01) increase in MUP mean duration, mean amplitude, percentage of long duration MUPs, and satellite rate, but to a lesser extent than MSA. Mean duration and satellite rate showed the least overlap among different groups in individual value distributions.Compared with MSA, DPN affects EAS to a lesser degree as judged by neurogenic MUP abnormalities in EMG. Mean duration and satellite rate may serve as the most discriminating aspects in MUP analysis of EAS.

To investigate the features and application of diaphragmatic electromyography (DEMG) in amyotrophic lateral sclerosis (ALS) patients.We recorded the electromyography of 43 diaphragms from 43 ALS patients by inserting concentric needle electrode from intercostal space, when they held their breath, breathed smoothly and drew deep breath, and took electromyography of 22 healthy diaphragms as controls. The percentage of forced vital capacity (%FVC) was performed simultaneously in 28 ALS patients.All subjects showed no side-effect. The spontaneous activities could be found when ALS patients held their breath. During the period of their smooth breath, the duration of their diaphragmatic motor unit action potential (DMUAP) (12.1 ms +/- 2.7 ms) was longer than those of controls, and the common logarithmic value of the amplitude (2.585 +/- 0.132) and the area (2.722 +/- 0.208) of DMUAP were larger than those of controls. The percentage of polyphasic (53%) and satellite potential (5%) was also increased in ALS patients. The duration (13.6 ms +/- 3.6 ms) of the ALS patients with clinical dyspnoea was longer than that (11.6 ms +/- 2.2 ms) of others without it. The spontaneous activities were correlated with clinical dyspnoea and %FVC.DEMG with needle electrode could evaluate the respiratory state of ALS patients at the level of electrophysiology. The duration and the spontaneous activity were its sensitive indexes.

To investigate the features and application of diaphragmatic motor evoked potential (DMEP) in amyotrophic lateral sclerosis (ALS) patients.To record the latency and amplitude of diaphragmatic compound muscle action potential (DCMAP) from 37 ALS patients and 31 control subjects with surface electrodes after transcranial and transcervical magnetic stimulation, central motor conduction time (CMCT) was calculated. The percentage of forced vital capacity (%FVC) was performed in 22 ALS patients simultaneously.Cortical and cervical latencies of the ALS patients were longer than those of the controls, and cortical and cervical amplitudes of the ALS patients were lower than those of the controls. CMCT of the ALS patients were longer than that of the controls. Cortical latency, cortical amplitude and CMCT were all correlated with the dysfunction of the pyramidal tract. Cortical latency and CMCT were also correlated with the clinical respiratory dysfunction, cervical latency was correlated with %FVC.CMCT, Cortical and cervical latencies are sensitive index in DMEP parameters reflecting respiratory dysfunction in ALS, CMCT reflects cortical spinal tract function of ALS patients associated with respiration. It would be helpful to detect the neurological basis of the respiratory disturbance in ALS combining CMCT with cervical latency.

To investigate the features and application of phrenic nerve conduction in amyotrophic lateral scle-rosis (ALS) patients.The latency and amplitude of diaphragmatic compound muscle action potential (DCMAP) were recorded among 44 ALS patients and 31 control subjects with surface electrodes after the cervical part of phrenic nerve was stimulated with electricity. The percentage of forced vital capacity (%FVC) was examined in 28 ALS patients simultaneously.Right and left phrenic distal motor latencies (PDML) of ALS patients were 8.4 ms +/- 2.2 ms and 7.6 ms +/- 1.4 ms respectively, longer than those of the controls, and the logarithmic value of amplitudes among ALS patients was 2.68 +/- 0.37, lower than that among the controls. Take the right side for example, although PDML was correlated with %FVC, it had no correlation with clinical respiratory dysfunction. Neither %FVC nor clinical respiratory dysfunction was correlated with the amplitude of DCMAP. The rate of abnormal PDML (47.7%) was higher than the rate of clinical dyspnea (25%).PDML is a sensitive index in phrenic conduction parameter reflecting respiratory dysfunction in ALS. Only when the PDML is combined with the central motor conduction time of the diaphragmatic motor evoked potential the nervous system basis of the respiratory disturbance in ALS can be revealed.

We recorded event-related potentials (ERPs) in 15 subjects in order to elicit a N270 of arithmetic conflict. Subjects calculated an arithmetic problem and matched their calculation result to an answer digit. They pressed a button when the presented digit is a true answer (condition 1) and pressed another button when the answer is false (condition 2). ERP components of P90, N130, P180, N200 and late positive component (LPC) were recorded in condition 1. In condition 2, N270 was elicited between N200 and LPC and it peaked at approximately 270 ms (268.6 +/- 29.0 ms at Cz). The peak latency of LPC in condition 2 (405.7 +/- 51.3 ms) is significantly delayed than condition 1 (307.5 +/- 22.7 ms). N270 reflects the endogenous conflict processing in human brain.

It is uncertain if the several brain areas in response to presemantic picture processing are functionally homogeneous. Subjects were asked to discriminate visual stimulus pairs and event-related potentials (ERPs) were recorded from the scalp. A line-drawing picture (S1) was followed by another stimulus (S2) 600 ms later. S2 was the same as S1 in condition 1, a reversed picture of S1 in condition 2, the corresponding Chinese word in condition 3 and the syllabic alphabet of S1 in condition 4. Amplitudes of ERPs over right posterior scalp with time window from 102-180 ms after the onset of S2 in condition 1 and 2 were significantly larger than condition 3 and 4. The N2 component on the right anterolateral scalp with time window from 182-240 ms was significantly larger in condition 1 than other conditions, whereas the N2 on the left anterolateral scalp with time window from 262-350 ms in condition 2, 3 and 4 was significantly larger than condition 1. It is suggested that pictures and words are processed in different systems at the presemantic stage: repetitive and physically deviant stimuli evoke different responses in different brain regions.

We studied eight patients with carcinoma of the pharynx and larynx (five cases) or lungs (three cases) who, during treatment with the radiosensitizing drug misonidazole, developed peripheral neuropathy dominated by severe sensory symptoms and signs mainly localized to the lower extremities. The symptoms partially subsided within months after cessation of therapy. Electrophysiological and histological findings indicated an axonal neuropathy with loss of large fibers and secondary demyelination. The neurotoxic property of misonidazole limits its therapeutic use.