A fine addition! A highly enantioselective and efficient procedure for the amino‐alcohol–zinc‐catalyzed addition of trimethylsilylacetylene to aromatic, α,β‐unsaturated, and aliphatic aldehydes has ...been developed (see scheme; R=aryl, alkynyl, or alkyl; TMS=trimethylsilyl; TBDMS=tert‐butyldimethylsilyl). The present protocol was successfully applied in the concise synthesis of the natural products marine alkynol and falcarindiol.
A one-step sintering process was developed to produce magnetocaloric La(Fe,Si)13/Ce-Co composites. The effects of Ce2Co7 content and sintering time on the relevant phase transformations were ...determined. Following sintering at 1373 K/30 MPa for 1–6 h, the NaZn13-type (La,Ce)(Fe,Co,Si)13 phase formed, the mass fraction of α-Fe phase reduced and the CeFe7-type (La,Ce)(Fe,Co,Si)7 phase appeared. The mass fraction of the (La,Ce)(Fe,Co,Si)7 phase increased, and the α-Fe phase content decreased with increasing Ce2Co7 content. However, the mass fraction of the (La,Ce)(Fe,Co,Si)7 phase reduced with increasing sintering time. The EDS results showed a difference in concentration between Co and Ce at the interphase boundary between the 1:13 phase and the 1:7 phase, indicating that the diffusion mode of Ce is reaction diffusion, while that of Co is the usual vacancy mechanism. Interestingly, almost 100 % single phase (La,Ce)(Fe,Co,Si)13 was obtained by appropriate Ce2Co7 addition. After 6 h sintering at 1373 K, the Ce and Co content in the (La,Ce)(Fe,Co,Si)13 phase increased for larger Ce2Co7 content. Therefore, the Curie temperature increased from 212 K (binder-free sample) to 331 K (15 wt.% Ce2Co7 sample). The maximum magnetic entropy change (−ΔSM)max decreased from 8.8 (binder-free sample) to 6.0 J/kg·K (15 wt.% Ce2Co7 sample) under 5 T field. High values of compressive strength (σbc)max of up to 450 MPa and high thermal conductivity (λ) of up to 7.5 W/m·K were obtained. A feasible route to produce high quality La(Fe,Si)13 based magnetocaloric composites with large MCE, good mechanical properties, attractive thermal conductivity and tunable TC by a one-step sintering process has been demonstrated.
The three-dimensional (3D) visualization of the functional bundles in the peripheral nerve provides direct and detailed intraneural spatial information. It is useful for selecting suitable surgical ...methods to repair nerve defects and in optimizing the construction of tissue-engineered nerve grafts. However, there remain major technical hurdles in obtaining, registering and interpreting 2D images, as well as in establishing 3D models. Moreover, the 3D models are plagued by poor accuracy and lack of detail and cannot completely reflect the stereoscopic microstructure inside the nerve. To explore and help resolve these key technical problems of 3D reconstruction, in the present study, we designed a novel method based on re-imaging techniques and computer image layer processing technology. A 20-cm ulnar nerve segment from the upper arm of a fresh adult cadaver was used for acetylcholinesterase (AChE) staining. Then, 2D panoramic images were obtained before and after AChE staining under the stereomicroscope. Using layer processing techniques in Photoshop, a space transformation method was used to fulfill automatic registration. The contours were outlined, and the 3D rendering of functional fascicular groups in the long-segment ulnar nerve was performed with Amira 4.1 software. The re-imaging technique based on layer processing in Photoshop produced an image that was detailed and accurate. The merging of images was accurate, and the whole procedure was simple and fast. The least square support vector machine was accurate, with an error rate of only 8.25%. The 3D reconstruction directly revealed changes in the fusion of different nerve functional fascicular groups. In conclusion. The technique is fast with satisfactory visual reconstruction.
•LaFe11.8Si1.2 alloys were prepared by either HPS or by SPS techniques.•With decreasing particle size, the porosity and (−ΔSM)max of HPS samples reduced.•SPS samples with initial powders of ...100–200 μm had larger (−ΔSM)max of 12.80 J/kg·K.•Due to low porosity and high α-Fe phase content, SPS samples had good mechanical properties.•SPS is a promising processing technology to prepare MCMs with excellent performance.
LaFe11.8Si1.2 bulk magnetocaloric materials were prepared by hot-pressing sintering (HPS) and spark plasma sintering (SPS) techniques. The effects of the particle size, phase content and porosity on the thermal conductivity, mechanical and magnetocaloric properties were studied. Our results demonstrated that the reduction of porosity in bulk magnetocaloric materials was an effective way to enhance the magnetocaloric effect. Compared to the HPS samples, the porosity of the SPS samples, with an initial powder size of 100−200 μm, reduced by 18%, which resulted in (−ΔSM)max and (−ΔSM)Vmax increasing by 15% and 19%, respectively. The SPS samples had a large (−ΔSM)max value in the range of 7.3‒12.8 J/kg·K (μ0ΔH=2T), good maximum compressive strength of 216‒636 MPa and thermal conductivity of 5.8‒7.6 W/m·K. Thus, SPS has been shown to be a promising processing technology to fabricate magnetocaloric materials (MCMs) with excellent performance.
LFe11.8Si1.2 bulk alloys were prepared by hot-pressing sintering or spark plasma sintering (a); The effect of the change of 1:13 phase content, Fe/Si ratio in 1:13 phase and porosity on (−ΔSM)max (b) and (−ΔSM)Vmax (c) for HPS and SPS samples. Compressive stress-strain curves of SPS samples (d); Thermal conductivity of SPS samples (e).
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Propolis is commonly used in traditional Chinese medicine. Studies have demonstrated the therapeutic effects of propolis extracts and its major bioactive compound caffeic acid phenethyl ester (CAPE) ...on obesity and diabetes. Herein, CAPE was found to have pharmacological activity against nonalcoholic fatty liver disease (NAFLD) in diet-induced obese mice. CAPE, previously reported as an inhibitor of bacterial bile salt hydrolase (BSH), inhibited BSH enzymatic activity in the gut microbiota when administered to mice. Upon BSH inhibition by CAPE, levels of tauro-β-muricholic acid were increased in the intestine and selectively suppressed intestinal farnesoid X receptor (FXR) signaling. This resulted in lowering of the ceramides in the intestine that resulted from increased diet-induced obesity. Elevated intestinal ceramides are transported to the liver where they promoted fat production. Lowering FXR signaling was also accompanied by increased GLP-1 secretion. In support of this pathway, the therapeutic effects of CAPE on NAFLD were absent in intestinal FXR-deficient mice, and supplementation of mice with C16-ceramide significantly exacerbated hepatic steatosis. Treatment of mice with an antibiotic cocktail to deplete BSH-producing bacteria also abrogated the therapeutic activity of CAPE against NAFLD. These findings demonstrate that CAPE ameliorates obesity-related steatosis at least partly through the gut microbiota-bile acid-FXR pathway via inhibiting bacterial BSH activity and suggests that propolis enriched with CAPE might serve as a promising therapeutic agent for the treatment of NAFLD.
Tight sandstone has a certain anisotropy. Using ultrasonic measurements of samples in three different directions and related matched experiments, this study systematically analyzes the pore structure ...and anisotropy of tight sandstone samples obtained from oil fields and compares results with those of shale. Results firstly show that the anisotropy of tight sandstone is mainly related to the compositional layering and thin interbedding which occur in different sedimentary environments. Tight sandstone has typical transverse isotropic medium characteristics, Young’s modulus increases in different directions with increasing confining pressure, Poisson’s ratio change is not obvious, anisotropic coefficients decrease with increasing effective pressure, and a certain linear relationship exists between ε, γ, and δ. This article finally summarizes anisotropy in different areas, thereby providing a foundation for the use of suitable appraisal models in different regions. This research can be used as an experimental reference for logging evaluation, seismic data interpretation, and fracturing develop of tight sandstones.
Abstract The objective was to evaluate the efficacy and safety of add-on artemether in first-episode, untreated people with schizophrenia, who were Toxoplasma gondii seropositive, and explore the ...change in T. gondii antibodies during treatment. In this eight-week, double-blind, randomized, placebo-controlled trial, 100 T. gondii seropositive participants with schizophrenia were randomized to either the artemether or placebo group. Participants in the artemether group received 80 mg artemether once per day during the second week (days 8–14) and the fourth week (days 22–28). Participants in the placebo group received identical looking placebo capsules. Psychopathology, adverse side effects and cognitive function were measured using standardized instruments. The group × time interaction effects for the scores of the Positive and Negative Syndrome Scale (PANSS) subscales and performances on all cognitive components were not significant, only the main effect of group was significant. Compared to the placebo group, artemether group participants showed significantly greater reduction in the PANSS negative symptom scale ( F(1,46) = 4.7, p = 0.03) and the Clinical Global Impressions Scale ( F(1,96) = 6.2, p = 0.01) scores, but there were no significant differences in the PANSS positive symptom and general psychopathology scales ( p > 0.05). There were also no significant differences between the two groups in performance on any of the Brief Assessment of Cognition in Schizophrenia (BACS) cognitive domains. The artemether–risperidone combination is safe and well tolerated, but artemether as an adjunct to risperidone does not appear to alleviate cognitive deficits of schizophrenia. Trial Registration Chinese Clinical Trial Register (ChiCTR) TRC-13003145
•Y2Fe16-xCoxSi/paraffin composites were prepared by three different orientation methods.•Orientation tuning improved the electromagnetic parameters and microwave absorption properties.•The ...permittivity and permeability of these composites could be enhanced by orientation methods a and c.•The (EAB)max of 8.4 GHz (2.1 mm) was obtained for the Y2Fe16Si/paraffin composites with method c.•These composites exhibited huge potential for microwave absorption in the X-Ku band.
Y2Fe16-xCoxSi/paraffin composites were prepared by three different orientation methods. The effect of these orientation methods and the magnetocrystalline anisotropy of Y2Fe16‒xCoxSi alloys on the electromagnetic parameters and the microwave absorption properties were investigated. The results demonstrated that orientation tuning improved the electromagnetic parameters and microwave absorption properties. Anisotropy in dielectric properties and magnetic properties of Y2Fe16-xCoxSi/paraffin composites were achieved by tuning the orientation of Y2Fe16-xCoxSi powders. The planar and conical anisotropic materials had superior microwave absorption properties than uniaxial anisotropic materials for the same orientation method. The Y2Fe16‒xCoxSi/paraffin composite had an effective absorption bandwidth of 8.4 GHz (9.6–18 GHz) and a reflection loss of ‒59.6 dB which can almost cover the X–Ku bands and exceed the performance of many reported absorbing materials, showing its great prospects for microwave absorption in the X–Ku bands.
Y2Fe16-xCoxSi/paraffin composites were prepared by method A, method C or method R (a); Electromagnetic parameters of Y2Fe16-xCoxSi/paraffin (x = 0) composites with methods A, C, R at 0.5‒18 GHz (b–e); The effective absorption bandwidth of the Y2Fe16-xCoxSi/paraffin (x = 0) composites with methods A, C and R at different thicknesses (f).
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Preclinical studies have shown that brain-derived neurotrophic factor (BDNF) may be involved in antidepressant action, and the BDNF gene has been suggested to be involved in the pharmacological ...treatment of major depressive disorder (MDD). In this study, the relationship between BDNF Val66Met polymorphism (Single Nucleotide Polymorphism Database ID: rs6265) and severity of depression, efficacy of fluoxetine and its side effects was tested in Chinese patients with MDD.
Patients with MDD took the oral selective serotonin reuptake inhibitor (SSRI) fluoxetine (20 mg/day) for 6 weeks. Its clinical efficacy and side effects were measured by the 17-item Hamilton Rating Scale for Depression and the Treatment-Emergent Symptoms Scale (TESS), respectively. The patients were genotyped for Val66Met polymorphism of the BDNF gene.
In the multivariate regression analysis, there was no significant association between severity of depression and BDNF Val66Met polymorphism. There was no association between efficacy of fluoxetine and BDNF Val66Met polymorphism, but there was a marginal positive suggestion that heterozygous patients tended to have a better remission with fluoxetine in comparison with homozygous analogs. Insomnia and decreased sexual desire, side effects of fluoxetine, may have an association with the BDNF Val66Met polymorphism, and Met allele carriers showed a lower incidence of these side effects.
These results indicate that there was a lack of association between severity of depression and BDNF Val66Met polymorphism in Chinese patients with MDD. The BDNF Val66Met polymorphism may play a major role in the efficacy and side effects of SSRI (fluoxetine) in Chinese patients with MDD.
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