This study aims at the development of magnetically recyclable solid catalysts for the production of biodiesel. To achieve this, the magnetically susceptible Fe3O4/MCM-41 composites with core-shell ...structure were prepared, and sodium silicate was then supported on the magnetic materials by using epichlorohydrin as a cross-linking reagent. The core-shell structured magnetic support and so-prepared solid catalyst were characterized by various techniques. Characterization results showed that the sodium silicate was chemically bridged onto the Fe3O4/MCM-41 composites without obvious damage to the structure of the magnetic support. The solid catalyst exhibited a strong magnetic response and displayed extraordinary catalytic activities in the transesterification of soybean oil for the production of biodiesel, with the oil conversion reaching 99.2% by using the methanol-to-oil molar ratio of 25:1 and catalyst loading of 3 wt% at reflux of methanol after 8 h of reaction. Moreover, the separation of the solid catalyst from reaction mixture was readily achieved by simple magnetic decantation without obvious mass loss, and the solid catalyst could be reused for five times for the heterogeneous transesterification.
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•Magnetic solid catalysts were used for biodiesel production in a heterogeneous manner.•The catalyst could give the soybean oil conversion of 99.2%.•The solid catalyst had a long-term catalytic activity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Abstract
Magnetic actuation has been well exploited for untethered manipulation and locomotion of small-scale robots in complex environments such as intracorporeal lumens. Most existing magnetic ...actuation systems employ a permanent magnet onboard the robot. However, only 2-DoF orientation of the permanent-magnet robot can be controlled since no torque can be generated about its axis of magnetic moment, which limits the dexterity of manipulation. Here, we propose a new magnetic actuation method using a single soft magnet with an anisotropic geometry (e.g., triaxial ellipsoids) for full 3-DoF orientation manipulation. The fundamental actuation principle of anisotropic magnetization and 3-DoF torque generation are analytically modeled and experimentally validated. The hierarchical orientation stability about three principal axes is investigated, based on which we propose and validate a multi-step open-loop control strategy to alternatingly manipulate the direction of the longest axis of the soft magnet and the rotation about it for dexterous 3-DoF orientation manipulation.
To solve the problem of heavy workload and high cost when acquiring the position of Ultra-Wideband (UWB) mobile base stations in sports fields, a fast self-positioning algorithm for UWB mobile base ...stations algorithm based on Time of Flight (TOF) is proposed. First, according to the layout of the base stations in the sports field, the local coordinate system is determined, and an equation based on the ranging information between the base stations is established; the Least Square method is used to calculate the coordinates of each base station, and the Newton Iteration method is used to converge the positioning results. Then the origin and propagation law of positioning error, as well as the method of reducing the positioning error are analyzed. The simulation data and experimental results show that the average positioning accuracy of the mobile base station is within 0.05 m, which meets the expected accuracy of the base station position measurement. Compared with traditional manual measurement methods, base station self-positioning can effectively save deployment time and reduce workload.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The microstructure and mechanical properties of an extruded Mg-12Dy-1.1Ni alloy have been investigated in this paper. The microstructure of the as-extruded alloy consisted of α-Mg matrix, Mg2Dy phase ...and a lamellar long-period stacking order (LPSO) phase distributed along the extrusion direction. Ageing the extruded alloy at 250 °C showed double peaks at 54 h and 108 h during ageing. The first ageing peak was due to a high number density of blocky 18R LPSO phases in conjunction with the precipitation of underaged 14H LPSO phase. The second ageing peak mainly arose from the precipitation of high volume fraction of 14H LPSO phases in the grain interior. Tensile testing indicated that the extruded alloy aged for 108 h exhibited the highest yield and ultimate tensile strengths from room temperature to 300 °C. The high tensile strengths of the alloy are mainly attributed to grain refinement and precipitation strengthening of 14H LPSO phase and dispersion strengthening of blocky 18R LPSO phase.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Cognitive-behavioral stress management (CBSM) is a psychotherapy that helps patients cognize and manage stress to improve mental health and quality of life. This study aimed to explore the influence ...of CBSM on anxiety, depression, and quality of life in non-small cell lung cancer (NSCLC) patients.
In total, 172 NSCLC patients who received tumor resection were randomized 1:1 into the usual care (UC) group (
= 86) and CBSM group (
= 86) to receive 10-week UC and CBSM interventions. Moreover, all participants attended a 6-month follow-up.
Hospital Anxiety and Depression Scales (HADS)-anxiety score at 3
month (M3) (
= 0.015) and 6
month (M6) (
= 0.018), HADS-depression score at M3 (
= 0.040) and M6 (
= 0.028), and depression rate at M6 (
= 0.035) were descended in CBSM group compared to UC group. Besides, depression severity was reduced at M6 (
= 0.041) in CBSM group compared to UC group, but anxiety severity only showed a decreased trend (
= 0.051). Additionally, Quality of Life Questionnaire-Core 30 (QLQ-C30) global health status score and QLQ-C30 function score at 1
month (M1), M3, and M6 were elevated (all
< 0.05), while QLQ-C30 symptoms score was declined at M1 (
= 0.031) and M3 (
= 0.014) in CBSM group compared to UC group. Notably, the efficacy of CBSM was impressive in patients with baseline depression or undergoing adjuvant therapy.
CBSM is a feasible intervention that effectively improves mental health and quality of life in postoperative NSCLC patients.
Contact resistance hinders the high performance of electrical devices, especially devices based on two-dimensional (2D) materials, such as graphene and transition metal dichalcogenide. To engineer ...contact resistance, understanding the resistance distribution and carrier transport behavior at the contact area is essential. Here, we developed a method that can be used to obtain some key parameters of contact, such as transfer length (L t), sheet resistance of the 2D materials beneath the contacting metal (R sh), and contact resistivity between the 2D materials and the metal electrode (ρc). Using our method, we studied the contacts between molybdenum disulfide (MoS2) and metals, such as titanium and gold, in bilayer and few-layered MoS2 devices. Especially, we found that R sh is obviously larger than the sheet resistance of the same 2D materials in the channel (R ch) in all the devices we studied. With the increasing of the back-gate voltage, L t increases and R sh, ρc, R ch, and the contact resistance R c decrease in all the devices we studied. Our results are helpful for understanding the metal–MoS2 contact and improving the performances of MoS2 devices.
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MicroRNAs (miRNAs) are widely known as critical regulators in isoflurane-induced neurotoxicity during the development of brain. Moreover, isoflurane could aggravate cognitive impairment in diabetic ...rats. The present study was designed to investigate the role and mechanism of miR-140-5p on isoflurane-induced neurotoxicity in diabetic rats. Firstly, a diabetic rat model was established by injection of streptozotocin (STZ) and identified by Morris water maze test. The result indicated that isoflurane treatment exacerbated STZ-induced cognitive impairment, as demonstrated by increase of the latency to the platform and decrease of the proportion of time spent in the target quadrant. Secondly, miR-140-5p was up-regulated in diabetic rats treated with isoflurane. Functional assays revealed that knockdown of miR-140-5p attenuated neurotoxicity in diabetic rats, which was shown by a decrease of the latency to the platform and an increase of the proportion of time spent in the target quadrant. Mechanistically, we demonstrated that miR-140-5p directly bonded to SNX12 (sorting nexin 12). At last, the neuroprotective effect of miR-140-5p knockdown against isoflurane-aggravated neurotoxicity in diabetic rats was dependent on up-regulation of SNX12 and inhibition of cell apoptosis. In summary, these meaningful results demonstrated the mitigation of miR-140-5p knockdown against isoflurane-aggravated neurotoxicity in diabetic rats via SNX12, suggesting a novel target for neuroprotection in diabetes under isoflurane treatment.
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Negative photoconductivity is observed in InAs nanowires (NWs) without a surface defective layer. The negative photoconductivity is strongly dependent on the wavelength and intensity of the light, ...and is also sensitive to the environmental atmosphere. Two kinds of mechanisms are discerned to work together. One is related to gas adsorption, which is photodesorption of water molecules and photo-assisted chemisorption of O2 molecules. The other one can be attributed to the photogating effect introduced by the native oxide layer outside the NWs.
A novel TiO2 supported core-shell (Pd@Ag) bimetallic catalyst was fabricated via the sequential photodeposition method. The Ag shell effectively blocks the high coordination sites on the Pd core, and ...therefore pronouncedly enhances the ethylene selectivity for the catalytic hydrogenation of acetylene in excess ethylene.
Recently, inhibiting the PD-1/PD-L1 checkpoint pathway utilizing anti-PD-1 or anti-PD-L1 antibodies has achieved great clinical success in cancer treatment. However, anti-PD-1 immunotherapy cannot be ...applied to all cancer patients, no more than 25% showed a positive response. Immunohistochemistry (IHC) is the gold standard to determine the PD-L1 expression level in malignant lesions, but a noninvasive imaging-meditated strategy is urgently required for clinical diagnosis to cover the shortcomings of invasive techniques. MX001, which is an anti-PD-L1 antibody, was labeled with Cu-64 (t 1/2 = 12.7 h) and purified by PD-10 chromatography. Comprehensive studies including positron emission tomography (PET), ex vivo biodistribution, IHC, and immunotherapy have been performed in mice bearing MC38 (PD-L1 positive (+)) and 4T1 (PD-L1 negative (−)) xenografts. PET imaging of 18FFDG was taken before and after therapy to monitor the therapeutic efficacy. 64CuCu-NOTA-MX001 exhibited 2.3 ± 1.2, 5.6 ± 2.1, 5.6 ± 1.2, 6.1 ± 1.1, 6.1 ± 0.5, and 10.2 ± 1.7%ID/g uptake in MC38 xenografts at 0.5, 12, 24, 36, 48, and 62 h post-injection (p.i.), respectively. Meanwhile, the uptake in the liver and muscle at corresponding time points was 17.5 ± 2.2, 8.4 ± 2.4, 11.3 ± 3.2, 7.2 ± 2.1, 7.9.1 ± 3.5, and 3.8 ± 1.8%ID/g, and 1.2 ± 0.5, 1.3 ± 0.4, 1.5 ± 0.5, 0.7 ± 0.1, 0.6 ± 0.2, and 0.2 ± 0.1%ID/g, respectively. The uptake of 18FFDG in MC38 and 4T1 xenografts at 1-h p.i. was 5.3 ± 0.4 and 6.4 ± 0.6%ID/g, while the uptake of 64CuCu-NOTA-MX001 was 5.6 ± 0.3 and 1.3 ± 0.4%ID/g at 12-h p.i. IHC analysis confirmed that the MC38 tumor exhibited high PD-L1 expression, and the 4T1 tumor, liver, and muscle exhibited low PD-L1 expression. In addition, MC38 xenografts were suppressed by MX001 about 88% in the immunotherapy study. MX001 was successfully developed as a fully human anti-PD-L1 antibody with a high binding affinity in mouse, monkey, and human. The in vivo pharmacokinetics of MX001 was evaluated with PET imaging after being radiolabeled with Cu-64. The uptake of 64CuCu-NOTA-MX001 was clearly correlated to the PD-L1 expression on various types of cancer. Subsequent immunotherapy studies demonstrated that MX001 could effectively suppress tumor growth with positive PD-L1 expression, but had poor antitumor efficacy on tumors which exhibited low PD-L1 expression. Together with the above results, MX001 has the potential to be further developed as an antibody theranostic agent for both PET imaging and immunotherapy of cancers in clinics.
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