Search

Efficient copper-catalyzed [3 + 2] cycloadditions of ethynyl indoloxazolidones with 1,3-cyclohexanediones to access functionalized furan derivatives under mild conditions.

An acid-catalyzed formal [3 + 2] cyclization/N,O-ketalization of in situ formed ortho-alkynyl quinone methides (o-AQMs) and tryptophol derivatives was developed.

Background Gasdermins (GSDMs) are a class of proteins related to pyrolysis and in humans, consist of GSDMA, GSDMB, GSDMC, GSDMD, DFNA5, and DFNB59. The inflammatory factors and cell contents released during pyrolysis can recruit immune cells and change the microenvironment. However, to date, there is a paucity of studies examining the relationship between GSDMs and the immune microenvironment in tumors. Therefore, this current report analyzed the expression of GSDM genes in tumors and their relationship with the immune microenvironment. Methods Apply GSCALite and GEPIA2 online analysis tools to analyze the gene expression levels and the Single nucleotide variant (SNV), copy number variation (CNV), and methylation characteristics of GSDM genes respectively. Use R software or TISIDB online analysis tool to carry out the correlation analysis required in the article. Furthermore, Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted to examine the role of these GSDM genes in various cancers. Results The results demonstrated that CNV can cause an increase in GSDM gene expression, and methylation can inhibit GSDM gene expression. The elevated expression of GSDMA, GSDMB, GSDMC, GSDMD, and DFNA5 in some or most tumors was often accompanied by elevated immune scores, increased immune cell infiltration, and high expression of major histocompatibility complex (MHC) molecules, chemokines and their receptors, and immune checkpoint-related genes. However, DFNB59 was often negatively correlated with these indicators in tumors. GSDMD was the most highly expressed GSDM protein in various normal tissues and tumors, and showed the strongest correlation with immune microenvironment-related genes. Moreover, the methylation of GSDMD was accompanied by low immune cell infiltration, low expression of MHC molecule-related genes, low expression of chemokines and receptor-related genes, and low expression of immune checkpoint-related genes. Conclusions Therefore, the expression of GSDM-related genes is associated with the tumor immune microenvironment. The GSDM genes, especially GSDMD, may be used as therapeutic targets to predict or change the tumor microenvironment and as biomarkers to predict the therapeutic efficacy of immune checkpoint inhibitors.

Background In this research, the factors that influence the self-precautionary behavior during the pandemic are explored with the combination of social support and a risk perception attitude framework. Methods An online survey was conducted among 429 members to collect information on demographic data, social support, perceptions of outbreak risk, health self-efficacy, and self-precautionary behaviors with the guide of the Social Support Scale, the COVID-19 Risk Perception Scale, the Health Self-Efficacy Scale and the Self-precautionary Behavior Scale. Results The research shows that among the three dimensions of social support, both objective support and support utilization negatively predict risk perception, while subjective support positively predicts health self-efficacy; health self-efficacy and risk perception significantly predict self-precautionary behavior; the relationship between risk perception and self-precautionary behavior is significantly moderated by health self-efficacy. Conclusions The combined influence of social capital and risk perception attitudinal frameworks on self-precautionary behavior is highlighted in this study, with the relationship between the public’s risk perception, health self-efficacy, and self-precautionary behavior intentions examined against the background of coronavirus disease 2019 (COVID-19). These findings contribute to understanding the impact of social capital factors on risk perception and health self-efficacy, which provides insight into the current status and influencing factors of the public’s precautionary behavior and facilitates early intervention during a pandemic.

Herein, we present a palladium-catalyzed tandem [4+1] cyclo­addition of 4-vinyl-1,4-dihydro-2H-3,1-benzoxazin-2-ones with ­N-tosyl­hydrazones. The reaction is accomplished by merging the in situ generated aza-ortho-quinone methides (aza-o-QMs) with nucleophilic carbenes. This method enables the construction of diverse indolines with broad functional group compatibility in good yields with high levels of diastereoselectivity under mild conditions.

The forest tree family Aceraceae is widespread in the northern hemisphere and it has ecological and economic importance. However, the phylogenetic relationships and classifications within the family are still controversial due to transitional intraspecific morphological characteristics and introgression hybridization among species. In this study, we determined the evolutionary relationships and molecular evolution of Aceraceae based on plastid phylogenomics and two nuclear gene variations. Phylogenetic analysis based on the plastid genomes suggested that Aceraceae species can be divided into two larger sub-clades corresponding to the two genera Acer and Dipteronia. Conjoint analysis of the plastid and nuclear gene sequences supported the classification with two genera in the family. Molecular dating showed that the two genera diverged 60.2 million years ago, which is generally consistently with previously reported results. Divergence hotspots and positively selected genes identified in the plastid genomes could be useful genetic resources in Aceraceae.

Adalimumab (ADA) and infliximab (IFX) are the cornerstones of the treatment of Crohn's disease (CD). It remains controversial whether there is a difference in the effectiveness and safety between IFX and ADA for CD.To perform a meta-analysis to compare the effectiveness and safety of ADA and IFX in CD.PubMed, Embase, Cochrane Library, and Web of Science databases were searched. Cohort studies were considered for inclusion. The primary outcomes were induction of response and remission, maintenance of response and remission, and secondary loss of response. Adverse events were secondary outcomes.Fourteen cohort studies were included. There was no apparent difference between the two agents in the induction response [odds ratio (OR): 1.27, 95% confidence interval (CI): 0.93-1.74,ADA and IFX have similar clinical benefits for anti-tumor necrosis factor-α naïve or non-naïve CD patients. Overall adverse events rate is higher in patients in the IFX group.

Pinus L. is the largest genus of conifers and provides a classical model for studying species divergence and phylogenetic evolution by gymnosperms. However, our poor understanding of sequence divergence in the whole plastid genomes of Pinus species severely hinders studies of their evolution and phylogeny. Thus, we analyzed the sequences of 97 Pinus plastid genomes, including four newly sequenced genomes and 93 previously published plastomes, to explore the evolution and phylogenetic relationships in the genus Pinus. The complete chloroplast genomes of Pinus species ranged in size from 109 640 bp (P. cembra L.) to 121 976 bp (P. glabra Walter), and these genomes comprised circular DNA molecules in a similar manner to those of most gymnosperms. We identified 9108 repeats where most of the repeats comprised the dispersed type with 3983 (44%), followed by tandem repeats with 2999 (33%), and then palindromic repeats with 2126 (23%). Sixteen divergence hotspot regions were identified in Pinus plastid genomes, which could be useful molecular markers for future population genetics studies. Phylogenetic analysis showed that Pinus species could be divided into two diverged clades comprising the subgenera Strobus (single needle section) and Pinus (double needles section). Molecular dating suggested that the genus Pinus originated approximately 130.38 Mya during the late Cretaceous. The two subgenera subsequently split 85.86 Mya, which was largely consistent with the other molecular results based on partial DNA markers. These findings provide important insights into the sequence variations and phylogenetic evolution of Pinus plastid genomes.

Abies chensiensis Van Tiegh. (Pinaceae) is a rare and endangered endemic conifer in China. In this study, using the Illumina sequencing platform, we firstly characterized its whole plastid genome sequence. Our study revealed that A. chensiensis have a typical plastid genome of 121,498 bp in length, comprised of a large single copy region of 76,484 bp, a small single copy region of 42,654 bp and two inverted repeat regions of 1180 bp. A total of 113 genes, 74 protein-coding genes, 35 tRNA, and 4 rRNA genes were identified. The phylogenetic analysis indicated that A. chensiensis was placed as a sister to the congeneric A. sibirica.

A Lewis acid-catalyzed one-pot aza-Michael addition/fragmentation/sulfinyl conjugate addition/cyclization cascade of o-QMs and arylsulfonyl hydrazides is described for the first time. This technology engages a broad range of substrates with both components under mild conditions, giving the corresponding valuable 3-sulfonylbenzofurans in generally good yields. These investigations show the use of arylsulfonyl hydrazides as nucleophiles for the first time in catalytic C–N and C–S bond formation with o-QMs.

Light influenced by the turbulent ocean can be fully characterized with the help of the power spectrum of the water's refractive index fluctuations, resulting from the combined effect of two scalars, temperature and salinity concentration advected by the velocity field. The Nikishovs' model [ Fluid Mech. Res. 27, 8298 (2000)] frequently used in the analysis of light evolution through the turbulent ocean channels is the linear combination of the temperature spectrum, the salinity spectrum and their co-spectrum, each being described by an approximate expression developed by Hill [ J. Fluid Mech. 88, 541562 (1978)] in the first of his four suggested models. The fourth of the Hill's models provides much more precise power spectrum than the first one expressed via a non-linear differential equation that does not have a closed-form solution. We develop an accurate analytic approximation to the fourth Hill's model valid for Prandtl/Schmidt numbers in the interval [3, 3000] and use it for the development of a more precise oceanic power spectrum. To illustrate the advantage of our model, we include numerical examples relating to the spherical wave scintillation index evolving in the underwater turbulent channels with different average temperatures, and, hence, different Prandtl numbers for temperature and different Schmidt numbers for salinity. Since our model is valid for a large range of Prandtl number (or/and Schmidt number), it can be readily adjusted to oceanic waters with seasonal or extreme average temperature and/or salinity or any other turbulent fluid with one or several advected quantities.

A novel Lewis base-catalyzed [4 + 3] annulation process for the construction of benzo[b]oxepine scaffolds has been developed. 1,4-Diazabicyclo[2.2.2]octane (DABCO) promotes the union of o-QMs and Morita–Baylis–Hillman carbonates in reasonable to excellent yields and good stereoselectivities (dr > 20:1). This straightforward, catalytic approach offers access to a variety of synthetically useful benzo[b]oxepine derivatives bearing oxindole scaffolds containing all-carbon spiro-quaternary stereocenters.

The calculation of non-point source (NPS) pollutant loads of nitrogen and phosphorus is the key step in preparing a pollution control plan. This study modified the export coefficient model by taking into account the precipitation, slope, distance between pollution sources and water bodies, and other relevant factors. The NPS pollution load assessment method established in this study can be applied to data-scarce basins and is suitable for plateau lake regions affected by terrain and precipitation. In this study, Chenghai Lake, which belongs to one of the nine major plateau lakes in Yunnan Province, is selected for the case study. This study first verifies the rationality of the improved export coefficient model based on actual observed values, and then utilizes the improved export coefficient model to assess the loads of dissolved nitrogen (DN) and dissolved phosphorus (DP) pollution. As indicated by the results, in 2014, the loads of DN and DP into Chenghai Lake are 158.48 t·a

This paper studies the experience, characteristic and future development of curriculum reform in China and Japan by comparing the current status of the curriculum reform in the above two countries. Taking the curriculums of the same major of two famous universities in two countries as an example, we explore the similarities and differences of two universities in the aspects of curriculum policy, curriculum setting and curriculum content. Then, the merits and drawbacks of different curriculums in two universities are compared and analyzed. Finally, we propose some constructive opinions and suggestions for the reform of university curriculum in our country.

Pinus pumila is a rare and endangered conifer plant in the family Pinaceae. Here, we determined the complete chloroplast (cp) genome sequence of P. pumila. The cpDNA was 117,398 bp in lengt...

Research on steam condensation in the presence of non-condensable gas is needed to support the thermal design of containment and capacity analysis of its cooling systems for nuclear power plants (NPPs). Based on classical and newly published literatures in related fields, the theoretical and experimental achievements are analyzed in this paper and research emphasis is consequently summarized. Considering the design and application characteristics of small-sized NPPs, several prospects of following-up study are proposed, which can be referenced in future work.

In the present work, a Ti–Nb alloyed layer was successfully formed on the pure titanium surface by double-glow plasma surface alloying technology with Nb and the wear resistance has been investigated. The microstructure, phase identification and elements distribution were analyzed by optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray powder diffraction (XRD). Specified tribological characterization was carried out by using a ball-on-disc tribometer and MicroXAM Surface Mapping Microscope at room temperature. The nano-hardness of the alloyed layer was also improved from 3.25 GPa to 5.25 GPa. As compared with pure titanium substrate, the friction coefficient of the alloyed layer was reduced from 0.57 to 0.27. The wear volume and relative wear rate at room temperature were reduced by 82% and 86%, which corresponded to an improvement of wear resistance. In the Haemolysis test, the treated sample exhibited better biocompatibility. Measuring the anodic polarization curves in Tyrode’s solution, the treated sample indicated a decreased corrosion rate.

In this paper, the TiO2 alloyed layer was successfully formed on pure titanium surface using the double glow plasma surface alloying technology. The microstructure and phase composition of the alloyed layer were analyzed by optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray powder diffraction (XRD). The micro-hardness of the alloyed layer was investigated by nano-indentation test. The surface roughness was decreased after the treatment. Measuring the anodic polarization curves in Tyrode’s solution, the corrosion rates of the untreated and treated samples were compared. The results indicated that the uniform dense TiO2 alloyed layer was obtained on the pure titanium surface. As compared with pure titanium, the free corrosion potential of TiO2 alloyed layer increased and the free corrosion current density decreased, which corresponded to a decreased corrosion rate. It led to the improvement of corrosion resistance of the pure titanium surface.

The hot-dipped zinc–aluminum alloy coating was used to avoid galvanic corrosion problems of titanium–aluminum alloy. The microstructure and corrosion properties of the coating were investigated by scanning electron microscopy, electrochemical measurement, and immersion test. The microstructure indicated that the coating consisted of outermost layer and middle interdiffusion layer, which metallurgically combined with the substrate. The electrochemical properties indicated that the coating on the titanium alloy decreased the electrochemical potential difference of galvanic couple. The corrosion current density showed that aluminum alloy contact with the coating changed the electrode, in other words, aluminum alloy specimen turned out to be the cathode in the galvanic couple. Immersion test was carried out to evaluate the performance of coating for galvanic corrosion, results confirmed that aluminum alloy contacted with coating on titanium–aluminum alloy exhibited less surface corrosion.

Premise of the study: Pinus armandii (Pinaceae) is an important conifer tree species in central and southwestern China, and it plays a key role in the local forest ecosystems. To investigate its population genetics and design effective conservation strategies, we characterized 18 polymorphic microsatellite markers for this species. Methods and Results: Eighteen novel polymorphic and 16 monomorphic microsatellite loci of P. armandii were isolated using Illumina MiSeq technology. The number of alleles per locus ranged from two to five. The expected heterozygosity ranged from 0.061 to 0.609 with an average of 0.384, and the observed heterozygosity ranged from 0.063 to 0.947 with an average of 0.436. Seventeen loci could be successfully transferred to five related Pinus species (P. koraiensis, P. griffithii, P. sibirica, P. pumila, and P. bungeana). Conclusions: These novel microsatellites could potentially be used to investigate the population genetics of P. armandii and related species.

Fourier transform near-infrared spectroscopy (FT-NIR) can reflect the overall molecular composition of microbial cells to identify different types of microorganisms. To establish an accurate, effective method about the differentiation and identification of Alicyclobacillus strains between different species, the present research performed the following studies by FT-NIR: (1) The FT-NIR spectra about seven type stains was clustered for data analysis. After preprocessing, reduction of data was performed by Principal Component Analysis (PCA) and Linear Discriminant Analysis(LDA), exploring the feasibility of differentiation and identification between different species, the result suggested that the PCA model can cluster the seven species of Alicyclobacillus strains correctly and the LDA model I can predict the unknown species with 100% accuracy. It evidenced that the method could identify different species of Alicyclobacillus strains preliminary. (2)In order to improve the robustness and practicability of the model, a total of 41 Alicyclobacillus strains including type and isolated strains were prepared for LDA model II, using the same methods as mentioned before. The result indicated that the LDA model validated by fifteen sample with 86.67% accuracy. It was more perfect and more comprehensive. As a result, the FT-NIR technology combined with chemometrics method can accurately and effectively identify Alicyclobacillus strains between different microbial species.

Orchidaceae is the 3rd largest family of angiosperms, an evolved young branch of monocotyledons. This family contains a number of economically-important horticulture and flowering plants. However, the limited availability of genomic information largely hindered the study of molecular evolution and phylogeny of Orchidaceae. In this study, we determined the evolutionary characteristics of whole chloroplast (cp) genomes and the phylogenetic relationships of the family Orchidaceae. We firstly characterized the cp genomes of four orchid species: Cremastra appendiculata, Calanthe davidii, Epipactis mairei, and Platanthera japonica. The size of the chloroplast genome ranged from 153,629 bp (C. davidi) to 160,427 bp (E. mairei). The gene order, GC content, and gene compositions are similar to those of other previously-reported angiosperms. We identified that the genes of ndhC, ndhI, and ndhK were lost in C. appendiculata, in that the ndh I gene was lost in P. japonica and E. mairei. In addition, the four types of repeats (forward, palindromic, reverse, and complement repeats) were examined in orchid species. E. mairei had the highest number of repeats (81), while C. davidii had the lowest number (57). The total number of Simple Sequence Repeats is at least 50 in C. davidii, and, at most, 78 in P. japonica. Interestingly, we identified 16 genes with positive selection sites (the psbH, petD, petL, rpl22, rpl32, rpoC1, rpoC2, rps12, rps15, rps16, accD, ccsA, rbcL, ycf1, ycf2, and ycf4 genes), which might play an important role in the orchid species’ adaptation to diverse environments. Additionally, 11 mutational hotspot regions were determined, including five non-coding regions (ndhB intron, ccsA-ndhD, rpl33-rps18, ndhE-ndhG, and ndhF-rpl32) and six coding regions (rps16, ndhC, rpl32, ndhI, ndhK, and ndhF). The phylogenetic analysis based on whole cp genomes showed that C. appendiculata was closely related to C. striata var. vreelandii, while C. davidii and C. triplicate formed a small monophyletic evolutionary clade with a high bootstrap support. In addition, five subfamilies of Orchidaceae, Apostasioideae, Cypripedioideae, Epidendroideae, Orchidoideae, and Vanilloideae, formed a nested evolutionary relationship in the phylogenetic tree. These results provide important insights into the adaptive evolution and phylogeny of Orchidaceae.

Oceanic turbulence is described by the oceanic refractive-index spectrum (ORIS), which considers several important hydrodynamic parameters. Based on ORIS, many optical oceanic quantities can be calculated using numerical integration. However, it is difficult to calculate the analytical solutions. In this paper, an approximate oceanic temperature spectrum is obtained by multiplying the non-Kolmogorov spectrum with a correction factor. By analogy with the obtained temperature spectrum, an approximate salinity spectrum and an approximate coupling spectrum are obtained. A linear summation of these three approximate spectra forms the approximate form of ORIS. The approximate form of ORIS we obtained helps calculate the analytical solutions of the relevant oceanic optical quantities.

The complete nucleotide sequence of the Taiwan red pine Pinus taiwanensis Hayata chloroplast genome (cpDNA) is determined in this study. The genome is composed of 119,741 bp in length, containing a pair of very short inverted repeat (IRa and IRb) regions of 495 bp, which was divided by a large single-copy (LSC) region of 65,670 bp and a small single-copy (SSC) region of 53,080 bp in length. The cpDNA contained 115 genes, including 74 protein-coding genes (73 PCG species), 4 ribosomal RNA genes (four rRNA species) and 37 tRNA genes (22 tRNA species). Out of these genes, 12 harbored a single intron, and one (rps12) contained a couple of introns. The overall AT content of the Taiwan red pine cpDNA is 61.5%, while the corresponding values of the LSC, SSC and IR regions are 62.2%, 60.6% and 63.6%, respectively. A maximum parsimony phylogenetic analysis suggested that the genus Pinus, Picea, Abies and Larix were strongly supported as monophyletic, and the cpDNA of P. taiwanensis is closely related to that of P. thunbergii.

Premise of the study: Pinus armandii (Pinaceae) is an important conifer tree species in central and southwestern China, and it plays a key role in the local forest ecosystems. To investigate its population genetics and design effective conservation strategies, we characterized 18 polymorphic microsatellite markers for this species. Methods and Results: Eighteen novel polymorphic and 16 monomorphic microsatellite loci of P. armandii were isolated using Illumina MiSeq technology. The number of alleles per locus ranged from two to five. The expected heterozygosity ranged from 0.061 to 0.609 with an average of 0.384, and the observed heterozygosity ranged from 0.063 to 0.947 with an average of 0.436. Seventeen loci could be successfully transferred to five related Pinus species (P. koraiensis, P. griffithii, P. sibirica, P. pumila, and P. bungeana). Conclusions: These novel microsatellites could potentially be used to investigate the population genetics of P. armandii and related species.