Search

The difference in the volatile flavors of five different Chinese acid-curd cheeses including milk fan, milk cake, Qula (yak milk cheese), Hurood cheese and milk knot was analyzed by sensory evaluation, gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS). The results of sensory evaluation showed that the five cheeses had a significant difference in flavor. Among them, dairy fan, with strong milky, fruity and bread-like aromas, had the best overall aroma performance and the highest preference score. The combination of GC-IMS and GC-MS expanded the detection range of volatile flavor compounds, and could more comprehensively reflect the volatile compounds in different Chinese acid-curd cheeses. The sensory evaluation results were verified by GC-IMS analysis. All five samples had their own characteristic peak areas, and the characteristic peak areas of dairy fan and Qula were significantly larger than those of the other samples. GC-MS analysis showed that the proportion of acids in dairy fan, Hurood cheese and Qula was the highest, the proportion of esters in milk cake was the highest, and the proportion of alcohols in milk knot was the highest. The calculation of odor activity value (OAV) combined with the results of principal component analysis (PCA) showed that ethanol, ethyl butyrate, ethyl caproate, 2-heptanone and δ-caprylactone were the major contributors to the flavor of dairy fan. Phenethyl formate, phenethyl acetate, caprylic acid, lauric acid and n-decanoic acid were the major contributors to the flavor of Qula. Dodecyl aldehyde was identified as the characteristic flavor compound of dairy cake. Partial least squares analysis (PLSA) revealed the correlation between aroma properties and volatile flavor compounds. Dairy fan has the potential to be developed and promoted in China because of its excellent flavor and consumer preference.

The behaviour of photoexcited electrons in light-responsive coordination polymers (CPs) significantly determines their performance in fluorescence sensing, smart materials, photoelectric display and photocatalysis, and this behaviour can be skilfully manipulated by optimizing the geometric and electronic structures of the ligand field around the metal ion. To reveal the micro-environmental effect of the ligand field on the bandgap and photoexcited electrons, three semiconductive Cd(II)-based CPs have been achieved through coordination of π-conjugated 2,6-bis(2-pyrazin-2-yl)-4-(4-(tetrazol-5-yl)phenyl)pyridine (HL) and 1,3,5-benzenetricarboxylic acid (H3BTC) with Cd(II) ion. Possessing N3O4 and O6 donors, complex 1 assumed an extended triple-decker sandwich structure with a central {Cd2(BTC)} sheet terminated up and down by planar L− spacers. Two quadrangular {Cd2(L)2} dimers with N4O3 and N4O2 donors were propagated by doubly deprotonated HBTC2− connectors to the cationic (4 4) layer of 2. The reproducible {Cd2(L)2} dimers with only N4O3 donors in 3 were extended by mirror-symmetric HBTC2− linkers to a bent chain. The distinct donor combinations in the local ligand fields of Cd(II) ions dominated the bandgaps and movements of the charge-carriers. Emitting intense steel blue fluorescence, complex 1 served as a highly efficient bilirubin probe with a quenching constant up to 9.48 × 104 M−1 driven by photo-induced electron charge and Förster resonance energy transfer. In contrast, complex 2, with excellent separation efficiency of charge carriers, acted as a photocatalyst to completely degrade methylene blue up to 97% within 90 minutes of UV irradiation. Apparently, slight modifications of the surroundings of the ligand field by a heterodonor strategy achieved a remarkable effect on the photophysical properties of the semiconductive CPs, providing valuable hints for the construction of photosensitive CPs. [ABSTRACT FROM AUTHOR]

In order to improve the shortcomings of poor dispersibility, easy agglomeration and easy corrosion of flaky zinc powder in inorganic zinc-rich coatings, the surface of flaky zinc powder was modified by silane coupling agent KH560 and cerium nitrate, and the optimum process conditions for surface modification of zinc powder was screened by polarization curve test.The changes in physical properties and corrosion resistance of zinc powder on zinc-rich coatings before and after modification were compared.Results showed that the optimal modification conditions of silane coupling agent KH560 were 12%(mass fraction), 60 ℃ of reaction temperature, pH 8 and 60 min of reaction time.The optimum dosage of cerium nitrate modified zinc flake/zinc powder was 0.01%(mass fraction)under the process conditions of room temperature, pH 7 and 60 min of reaction time.The dispersibility of modified zinc powder in water was improved.Moreover, the workability, drying time and adhesion of the modified zinc powder changed significantly.The corrosion current of the coating prepared by modified zinc powder was reduced by about 1 order of magnitude, the polarization resistance was increased by about 1 order of magnitude, and the corrosion resistance of the coating was significantly improved.In general, the cerium nitrate modified coating had the lowest passivation current and the smallest corrosion rate, which could be recommended to use cerium nitrate modified zinc powder for long-term protection.a

A new species of the firmoss from China, Huperzia crassifolia sp. nov., is described and illustrated based on morphological characters and molecular evidence. The new species resembles species associated with the H. javanica complex, in particular H. javanica based on leaf shape and serrations, but can be easily distinguished by elliptic lanceolate and thick coriaceous leaves, well differentiated seasonal constriction zones, and reflexed leaf margins when get dried. Phylogenomic reconstruction using whole chloroplast genome sequences recovered H. crassifolia as sister to H. sutchueniana and only distantly related to morphological similar species H. javanica, H. nanlingensis, and H. serrata. The genome size 2C = 17.2 pg indicated the new species to be a tetraploid, whereas diploid H. javanica had a genome size of 8.7 pg. Morphological characters, distribution, and conservation status of the new species are also presented. [ABSTRACT FROM AUTHOR]

Introduction Programmed death-1 receptor (PD-1) or its ligand-1 (PD-L1, B7-H1) is a promising therapeutic target in aggressive cancers (1, 2). PD-1 is mainly expressed by exhausted or suppressive lymphocytes and [...], Programmed death-1 receptor ligand 1 (PD-L1) is a promising therapeutic target in aggressive cancers. However, immune landscapes and cancer hallmarks of human PD-[L1.sup.+] tumors as well as their roles in determining therapeutic efficacies are unknown. Here, we showed, in detailed studies of gene data regarding 9769 patients of 32 types of human cancers, that PD-L1 could not exclusively represent the IFN-[gamma] signature and potentially signified proinflammatory myeloid responses in a tumor. PD-L1 heterogeneity endowed by local immune landscapes controlled cancer hallmarks and clinical outcomes of patients. Mechanically, NF-[kappa]B signal elicited by macrophage inflammatory responses generated PD-[L1.sup.+] cancer cells exhibiting capabilities to aggressively survive, support angiogenesis, and metastasize, whereas STAT1 signal triggered by activated T cells induced PD-[L1.sup.+] cancer cells susceptive to apoptosis. Importantly, PD-[L1.sup.+] cancer cells generated by macrophages established great resistance to conventional chemotherapy, cytotoxicity of tumor-specific effector T cells, and therapy of immune-checkpoint blockade. Therapeutic strategy combining immune-checkpoint blockade with macrophage depletion or NF-[kappa]B inhibition in vivo effectively and successfully elicited cancer regression. Our results provide insight into the functional features of PD-[L1.sup.+] tumors and suggest that strategies to influence functional activities of inflammatory cells may benefit immune-checkpoint blockade therapy.

Interlayer magnetic couplings of low-dimensional magnets have significantly dominated magnetic behavior through skillful regulation of interlayer interacting forces. To identify interaction-force-regulated interlayer magnetic communications, two air-stable Co(II)-based coordination polymers (CPs), a well-isolated layered structure with approximately 12.6 Å interlayer separation and a carboxylate-extended three-dimensional framework with an inter-ribbon distance of 5.8 Å, have been solvothermally fabricated by varying polycarboxylate mediators in a ternary CoII-tetrazolate–carboxylate system. The layered CP with antiparallel-arranged {Co2(COO)2}n chains interconnected only via cyclic tetrazolyl linkages behaves as a spin-canted antiferromagnet with a Néel temperature of 2.6 K, due to strong intralayer antiferromagnetic couplings and negligible interlayer magnetic interactions. In contrast, the compact three-dimensional framework with corner-sharing Δ-ribbons tightly aggregated through μ2–η1:η1-COO− is a field-induced metamagnet from a canted antiferromagnet to a weak ferromagnet with a small critical field of Hc = 90 Oe. Apparently, these interesting magnetic responses reveal the importance of an interacting force from the magnetic subunits for the magnetic behavior of the molecular magnet, greatly enriching the magnetostructural correlations of transition-metal-based molecular magnets. [ABSTRACT FROM AUTHOR]