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Benzophenone (BP) and N‐vinylpyrrolidone (NVP) were used to modify the surface of polylactide (PLA) films by UV grafting method. The effects of light distance, temperature, reaction time, and modifier concentration on the structure and properties of PLA films were investigated by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy (XPS), nuclear magnetic resonance spectroscopy, differential scanning calorimetry (DSC), and universal testing machine (UTM). With BP and NVP UV grafting, the hydrophilicity of PLA films is improved, but their thermal and mechanical properties are reduced under different surface modification condition. Base on the principle of good surface hydrophilicity, better mechanical and thermal properties, the hydrolytic degradation performance of modified PLA films in artificial seawater at 70°C was studied by scanning electron microscopy, XPS and DSC. The research results show that the degradation of modified PLA films mainly occurs in the amorphous region, and the degradation process conforms to surface hydrolysis mechanism. The grafting modification of NVP is better than BP to accelerate the degradation process of PLA films in artificial seawater. The degradation of modified PLA undergoes water molecule erosion and autocatalytic degradation reaction. The degradation of BP‐PLA obeys the first‐order kinetics in part, while the degradation of NVP‐PLA is more complex. Therefore, surface hydrophilicity modification is an effective technique for improving the degradability of PLA. [ABSTRACT FROM AUTHOR]

A series of Fe3O4/PLA composites are controllably prepared using consecutive reaction route. The neat PLA and its composites are characterized by FT-IR, WAXRD and XPS for composition analysis. The performances of PLA and Fe3O4/PLA composites are, respectively, determined by SEM, VSM, CAM, POM, DSC and TG. Fe3O4 particles are a good dispersion in the PLA matrix, and the saturation magnetization values of PLA have increased from 0.33 to 5.06 emu/g. When PLA is transformed into composites, the mean thickness of composites has decreased and water contact angle of composites has increased due to heavy and hydrophobicity Fe3O4. After addition of Fe3O4 particles, the 50 k, 100 k and 200 k PLA's crystallization rate is severally increased to 1.84, 1.56 and 1.44 times. It is concluded that the Fe3O4 particles are the efficient crystallization nucleating agent of PLA and faster accelerate the crystallization of low molecular weight PLA in comparison with high molecular weight PLA. The melting points of Fe3O4/PLA composites slightly have decreased compared with the neat PLA, which is in accord with the melting point of the mixture that is lower than that of the pure substance. By introducing 5 mass% of Fe3O4 particles to PLA, the initial decomposition temperatures reached to higher temperatures as compared to the neat PLA, and the final char yield is about 4.60%. The well dispersion of the particles in the PLA matrix is thought to be an effective barrier to the permeation of heat, which would improve the thermal stability. [ABSTRACT FROM AUTHOR]

Increasing evidence indicates an interaction between dysbiosis of the microbiota and the pathogenesis of schizophrenia. However, limited information is available on the specific microbial communities associated with symptoms of schizophrenia. Therefore, this study aimed to investigate gut microbiota dysbiosis and its relationship with psychopathologies in schizophrenia. We recruited 126 participants and divided them into three groups according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, criteria—acute group (patients with acute schizophrenia), remission group (patients with schizophrenia in remission), and control group (healthy controls). Psychotic symptoms were evaluated using the Positive and Negative Syndrome Scale. Microbiota compositions, diversity and community structure were evaluated using 16S rRNA sequencing. Pearson's correlation analysis was used to evaluate the association between bacterial taxa and psychotic symptoms. The beta-diversity of microbiota composition in the acute group was distinct from that in the remission and control groups (PC1 = 21.11% vs. PC2 = 12.86%, P = 0.021). Furthermore, Pearson's correlation analysis revealed that abundance of Haemophilu s was positively correlated with negative psychiatric symptoms (r = 0.303, P = 0.021), while abundance of Coprococcus was negatively correlated with negative psychiatric symptoms (r = − 0.285, P = 0.025). Moreover, abundance of Haemophilus was positively correlated with cognition (r = 0.428, P = 0.009), excitement (r = 0.266, P = 0.037), and depression (r = 0.295, P = 0.020). The study findings suggest that alterations in certain gut microbiota may interfere with psychological symptoms in schizophrenia. Our results provide evidence that may help in the development of therapeutic strategies using microbial-based targets. The data that support the findings of this study have been deposited in the NCBI (https://submit.ncbi.nlm.nih.gov/) with accession number SUB9453991. [ABSTRACT FROM AUTHOR]

This paper proposes a robust wavelet-based tightly coupled Global Positioning System (GPS)/ Beidou Navigation Satellite System (BDS)/Inertial Navigation System (INS) integration scheme aiming to improve the overall position accuracy during signal outages. A robust wavelet denoising model based on α-trimmed mean filter demonstrates its effectiveness on noise reduction and gross error elimination of inertial sensor raw data. Thereafter, a robust wavelet-based tightly coupled GPS/BDS/INS integration scheme is proposed, and GPS/BDS double-difference (DD) carrier-phase and pseudorange measurements are introduced to build a 27-state tightly coupled GPS/BDS/INS integration equation. The extended Kalman filter (EKF) has been designed for state estimation, and the inclusion of BDS enhances the satellite geometric strength of the whole navigation system. A field vehicle test indicates the position accuracy of five simulated GPS/BDS outages can be improved by about 7, 16, and 33% for north, east, and up components with the proposed scheme compared to standard integration scheme, and gross errors have been detected and eliminated with the new integration scheme. The authors also find that the BDS phase residual is larger than GPS and satellite dependent in the tightly coupled GPS/BDS/INS integrated navigation system. [ABSTRACT FROM PUBLISHER]

Abstract: Salen–Na2(1) and (Salen)2–La–Na(2) complexes have been prepared and structurally characterized [Salen= N,N′-bis (3,5-di-tert-butylsalicylidene)-1,3-propanediamine]. Experimental results show that the two complexes are efficient catalysts for the ring-opening polymerization (ROP) of l-lactide. According to the data of 1H NMR and electrospray-ionization (+ESI) mass spectrum, it is suggested that the obtained polymer is mainly cyclic polylactide (PLA) for a short PLA chain, but a mixture of cyclic and linear PLA for a long PLA chain. Structure–activity analysis of the two complexes is also done. We investigated why Salen–Na2 complex is more active (Salen)2–La–Na complex as the catalyst in the ROP of l-lactide and why the PLA catalyzed by complex 2 has lower PDIs than that catalyzed by complex 1. [Copyright &y& Elsevier]

In the crystal structure of the title compound, C(28)H(40)N(2)O(3)S, there are two mol-ecules per asymmetric unit; in each of these mol-ecules, the cyclo-hexyl rings adopt chair conformations. The dihedral angles between the benzene rings are 16.89 (9) and 34.11 (9)°. Each mol-ecule contains an intra-molecular O-H⋯N hydrogen bond, and inter-molecular N-H⋯O hydrogen bonds are also present. In both mol-ecules, the methyl groups of one tert-butyl group are disordered over two positions; the site-occupancy factors in both cases are ca 0.6 and 0.4.

The title compound, C(37)H(52)O(4)S, was obtained by the reaction of 6,6'-(ethane-1,1-di-yl)bis-(2,4-di-tert-butyl-phenol) and 4-methyl-benzene-1-sulfonyl chloride. The mol-ecular conformation is stabilized by an intra-molecular O-H⋯O hydrogen bond. Two of the tert-butyl groups are disordered over two sets of sites with occupancies 0.530 (15)/0.470 (15) and 0.615 (11)/0.385 (11).