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In order to explore the pollution characteristics and potential sources of polycyclic aromatic hydrocarbons (PAHs) in the polluted air of a port area, PM

Cyclopentadienyliron dicarbonyl based allenyliron complexes were prepared, and their formal [3 + 2] cycloaddition with a number of dipolar reagents was investigated as a means of preparing heterocy...

Background The clinical characteristics of Parkinson’s disease (PD) differ between men and women, and late- and early-onset patients, including motor symptoms and some nonmotor symptoms, such as cognition, anxiety, and depression. Objective To explore the features of excessive daytime sleepiness (EDS) and night-time sleep quality in PD patients of different sexes and age at onset (AAO). Methods Demographic data and clinical characteristics of 586 PD patients were collected. Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI) were used to investigate the daytime drowsiness and nocturnal sleep. Multivariate logistic regression analysis was used to explore the risk factors of EDS and poor night-time sleep quality. Results Sleep disorders were common in PD patients. EDS was more prominent in men than in women. There was no significant difference in ESS scores between late-onset PD (LOPD) and early-onset PD. LOPD patients had a higher probability of poor night-time sleep quality. Male sex, disease duration, and depression were risk factors for EDS. In all patients of both sexes and all AAO, depression was a risk factor for poor night-time sleep. Conclusion More attention should be paid to sleep disorders of PD patients, especially male LOPD patients. Depression is a common risk factor for EDS and poor sleep quality in PD patients.

Background The undergraduate program of psychiatry has been widely established in recent years to improve the education and recruitment of psychiatrists in China. We aim to investigate the career choice of medical students majoring in psychiatry in China and the influential factors. Method This multicenter study was conducted in 26 medical schools in China from May to October of 2019. Participants included 4610 medical students majoring in psychiatry and 3857 medical students majoring in clinical medicine. Multivariable logistic regression was used to investigate the influential factors of students’ choices of psychiatry at matriculation and as a career. Results 44.08% of psychiatry majored students gave psychiatry as a first choice at matriculation, and 56.67% of them would choose psychiatry as a career, which was in sharp contrast to the proportion of clinical medicine majored students who would choose psychiatry as a career (0.69%). Personal interest (59.61%), suggestions from family members (27.96%), and experiencing mental problems (23.19%) were main reasons for choosing psychiatry major at matriculation. Personal interest (odds ratio [OR] = 2.12, 95% confidence interval [CI] = 1.87–2.40), experiencing a psychiatry clerkship (OR = 1.99, 95% CI = 1.28–3.08), being female (OR = 1.50, 95% CI = 1.30–1.68), experiencing mental problems (OR = 1.33, 95% CI = 1.28–1.56), and suggestions from family members (OR = 1.25, 95% CI = 1.08–1.46) correlated positively with students’ choice of psychiatry as career. Students who lacked psychiatry knowledge (OR = 0.49, 95% CI = 0.29–0.85) or chose psychiatry because of lower admission scores (OR = 0.80, 95% CI = 0.63–0.97) were less likely to choose psychiatry as a career. Conclusion More than half of psychiatry majored medical school students planned to choose psychiatry as their career, whereas very few students in the clinic medicine major would make this choice. Increasing students’ interest in psychiatry, strengthening psychiatry clerkships, and popularizing psychiatric knowledge are modifiable factors to increase the psychiatry career intention. The extent to which medical students’ attitudes toward psychiatry can be changed through medical school education and greater exposure to psychiatry will need further investigation.

An iron-catalysed C-H functionalisation of simple monosubstituted allenes for the synthesis of 1-tetrahydroisoquinolinyl 1,1-disubstituted allenes is reported. This transformation represents the first example of a direct conversion of allenic C-H bonds to C-C bonds through cross dehydrogenative coupling. The optimized protocol features broad scope and employs mild, functional group tolerant conditions.

During the last few decades, the most widely favored models for coronal heating have involved the in situ dissipation of energy, with footpoint shuffling giving rise to multiple current sheets (the nanoflare model) or to Alfvén waves that leak into the corona and undergo dissipative interactions (the wave heating scenario). As has been recognized earlier, observations suggest instead that the energy deposition is concentrated at low heights, with the coronal loops being filled with hot, dense material from below, which accounts for their overdensities and flat temperature profiles. While an obvious mechanism for footpoint heating would be reconnection with small-scale fields, this possibility seems to have been widely ignored because magnetograms show almost no minority-polarity flux inside active-region (AR) plages. Here, we present further examples to support our earlier conclusions (1) that magnetograms greatly underrepresent the amount of minority-polarity flux inside plages and “unipolar” network, and (2) that small loops are a major constituent of Fe ix 17.1-nm moss. On the assumption that the emergence or churning rate of small-scale flux is the same inside plages as in mixed-polarity regions of the quiet Sun, we estimate the energy flux density associated with reconnection with the plage fields to be on the order of $10^{7}~\mbox{erg}\,\mbox{cm}^{-2}\,\mbox{s}^{-1}$ 10 7 erg cm − 2 s − 1 , sufficient to heat the AR corona.

Myocardial infarction is the highest cause of cardiovascular death. Previous studies found that patients with myocardial infarction have elevated serum IL-37 and IL-37 treatment significantly alleviates adverse remodeling in myocardial infarction mice. However, the underlying mechanism of IL-37 in myocardial infarction is still unknown. Here we explored the underlying mechanism of IL-37 in attenuating myocardial infarction.The myocardial infarction mice model was constructed by left anterior descending ligation and then submitted to recombinant IL-37 administration. The histology and cardiac function were detected by HEMasson staining and echocardiography, respectively. The macrophage phenotypes were analyzed by flow cytometry and real-time PCR. The cytokines in serum and cell culture supernatant were determined by ELISA. In addition, THP-1 cells were used in vitro to investigate the underlying mechanisms.Infarcted mice showed increased inflammatory cell infiltration and impaired cardiac function. IL-37 treatment alleviated pro-inflammatory macrophage infiltration, tissue injury, and collagen deposition in hearts on day 3 and 7 after infarction in mice. In addition, IL-37 application modulated the balance between M1 and M2 macrophages in infarcted hearts. In vitro, THP-1 cell line polarization was also regulated by IL-37, companied by YAP phosphorylation and NLRP3 inactivation. Verteporfin, a YAP inhibitor, could abolish IL-37-induced NLRP3 inhibition and M2 macrophage polarization.Our results demonstrated that IL-37 achieves a favorable therapeutical function on myocardial infarction by modulating YAP-NLRP3 mediated macrophage programming, providing a promising drug for the treatment of myocardial infarction.

Ecological ditches and bioretention ponds have received widespread attention and application due to their runoff pollution control capabilities and ecological benefits. However, a single ecological ditch or bioretention pond often has problems, such as unstable nitrogen and phosphorus removal and substrate clogging in rural runoff pollution control. Thus, we connected the two facilities in a series to construct a combined system, using the ecological ditch to pretreat, therefore reducing the pollution load of the bioretention pond and mitigating substrate clogging. At the same time, the submerged area was set and an external natural carrier carbon source was added in the bioretention pond to improve the nitrogen removal. The effects of the carrier carbon source, rainfall intensity, and alternating wet and dry conditions on the control of rural runoff pollution by the combined system were explored. The results showed that adding straw and sawdust as carrier carbon sources could increase the TN removal of the bioretention pond by 19.9% and 20.4%, respectively. When the simulated rainfall intensity increased from light rain to heavy rain, the removal efficiencies of COD, NH

Given the serious threat of foodborne multidrug-resistant bacteria to animals and humans, finding an effective antibacterial compound has always been an important topic for scientists. Here, from the soil of Changbaishan, we have identified a bacterium that can inhibit the growth of Staphylococcus aureus. Nr genome database analysis and phylogenetic analysis showed that strain CB6 belongs to Bacillus velezensis. We found that the crude extract of strain CB6 has broad-spectrum antibacterial activity against foodborne pathogens. In addition, we showed that the crude extract loses antibacterial activity after treatment with papain. Next, strain CB6 was purified using ammonium sulfate precipitation, a Sephadex G-75 gel filtration column and high-performance liquid chromatography system (HPLC). Liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis indicated that the antibacterial compound was the protein ATP synthase subunit α (ATP-1), with a molecular weight of 55.397 KDa. Moreover, we reported the complete genome sequence of strain CB6, which is composed of a unique circular 3,963,507 bp chromosome with 3749 coding genes and a G + C content of 46.53%. The genome contained 12 gene clusters with antibacterial functions, which constituted over 20.947% of the complete genome. Of note, the amino acid sequence encoding the ATP-1 protein in the strain CB6 genome was identified. In addition to these findings, we speculate that the ATP-1 protein may provide energy for secondary metabolites, which in turn will improve the antibacterial activity of the secondary metabolites. All the above important features make the ATP-1 as a potential candidate for the development of new antibacterial drugs and food preservatives in the future.

The parametric instability of homogeneous couplers with and without viscoelasticity has been the subject of many interests. Recently, an attention is given to the use of nonhomogeneous links to reduce the happening of dynamic instability of mechanisms. Therefore, the objective of this study is to perform qualitative analysis of beam-like members composed of periodically embedded arrays in transverse direction to diminish the possibility of occurrence of large amplitude vibration. By assuming that the member is an inhomogeneous continuum, the periodicity and matching conditions across the interfaces of arrays and layers are taken into account by the Fourier series. The embedded arrays have different geometric and material properties and carry linear viscoelastic Kelvin–Voigt model. The proposed model is evaluated by applying it as a coupler into a slider-crank mechanism to examine the influence produced by arrays to the primary and secondary parametric instability. Result shows that the stiffness ratio between arrays and basic layers has visible effect on narrowing the regions of dynamic instability. Meanwhile, even if the damping of basic layer is light, increasing the damping ratio of arrays increases the capability of the coupler to suppress resonant peaks of vibration. As the damping of basic layer is moderate, the combination of stiffness ratio and damping ratio produces significant influence on diminishing the occurrence of large amplitude vibration, even though the fundamental frequency of the coupler is close to the resonant frequency. It is concluded that the growth of small amplitude vibration into large motion regime caused by parametric resonance can be effectively attenuated if the material and geometric properties between arrays and basic layers of the coupler are properly arranged.

In spite of their rich stoichiometric chemistry, cyclopentadienyliron(II) dicarbonyl complexes are rarely used as catalysts in organic synthesis. Inspired by precedents in the chemistry of cationic olefin complexes and neutral allylmetal species, our group has developed a coupling of alkynes or alkenes with aldehydes and other carbonyl electrophiles to give homopropargylic and homoallylic alcohols, respectively, by using a substituted cyclopentadienyliron(II) dicarbonyl complex as the catalyst. In this article, we first contextualize this development within the conceptual background of C–H functionalization chemistry and relative to key stoichiometric precedents. We then give an account of our group’s discovery and development of the catalytic α-functionalization of alkenes and alkynes with electrophilic reagents.IntroductionPreliminary Stoichiometric WorkHydroxyalkylation Development and ScopeConclusions and Future Directions

In order to avoid the effect of photon defect on the imaging during X-ray generation, an imaging integral filter based on quantum enhancement was proposed in this paper to effectively reduce the sensitivity of X-ray detection system for quantum noise. Firstly, the coupling constraint at the end of the image intensifier was analyzed by discussing the X-ray imaging mechanism. The effects of quantum thermal noise and defects on spectrum transfer were studied from the micro perspective. Then the effectiveness of the new integral filter method was verified from the view of the integral effect of fundamental space frequency transfer characteristics in Fourier spectrum. Finally, the superiority and real-time performance of the quantum enhancement filter method were verified by the comparison filter testing.

This study presents the design of an observer-based iterative learning control law for linear systems using the stability theory and optimal function. The observer is introduced for states condition monitoring and output feedback. The D-type iterative learning control law is utilised to update the control inputs. Properties of stability, convergence, robustness, and optimality are investigated and demonstrated by stability theory and optimal theory. The convergence properties of the observer-based iterative learning control design are obtained by linear matrix inequalities. A simulation example is used to illustrate the validity and effectiveness of the proposed method.

Koi carp (Cyprinus carpio) are well-known and highly valuable fish in the international ornamental fish community that have been plagued by Aeromonas veronii infections in recent years. Some A. veronii infections are serious enough to cause death. Lactobacillus plantarum, a probiotic, is one of the most environmentally friendly and safe alternatives to antibiotics for use as a feed additive for aquatic animals such as fish. The present study investigated the effects of L. plantarum C20015 on growth performance, immune responses, and eradication of A. veronii infection in koi carp. During a 6-week feeding experiment in an indoor aquarium and a 14-day A. veronii artificial infection experiment, a control diet group was fed with untreated feed twice a day, while experimental groups were given different concentrations of L. plantarum in their feed. The results indicated that the specific growth rate and percent weight gain of fish were significantly higher in the experimental groups than in the control diet group (P < 0.05). The activity of superoxide dismutase (SOD), peroxidase (POD), and lysozyme (LZM) and the levels of IgM antibody were significantly higher in the L. plantarum–supplemented groups than in the control diet group, and the enzymatic activity in the 108 CFU/g C20015 group was higher than that in the 107 CFU/g C20015 and 109 CFU/g C20015 groups (P < 0.01). In contrast, alkaline phosphatase (AKP) activity in the experimental groups was the highest at 42 days. All fish in the control diet group died 7 days after A. veronii infection. After 14 days, the relative percent survival (%, RPS) of the fish in the L. plantarum–supplemented groups was significantly higher than that of the fish in the control group, and the 108 CFU/g C20015 group had the highest RPS. Therefore, we first reported that fish fed with 108 CFU/g of L. plantarum C20015 could promote food intake and growth for koi carp.

Background: Brucea javanica oil emulsion (BJOE) is a traditional Chinese medicine with recognized antitumor effects in various cancers, but the effects and mechanisms of action of BJOE against cervical cancer need to be further studied. Herein, we investigated the effects of BJOE on the human papillomavirus (HPV)16-expressing human cervical cancer line SiHa and explored the possible underlying mechanisms. Methods: Cell viability and apoptosis of SiHa cells treated with BJOE were assessed by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and annexin V-fluorescein isothiocyanate (annexin V-FITC)/propidium iodide (PI) staining assays, respectively. Quantitative reverse transcription- polymerase chain reaction and Western blot analyses were performed to assess the expression levels of the E6 oncogene and key signaling molecules involved in apoptosis. A subcutaneous xenograft nude mouse model bearing SiHa cells was established and treated with BJOE through intraperitoneal injection. Tumor growth was monitored, and immunohistochemical analysis was performed. Results: BJOE exhibited substantial cytotoxic effects in SiHa cells and significantly suppressed tumor growth in SiHa cell xenografts. BJOE inhibited E6 expression and induced apoptosis in vitro in a dose- dependent manner. BJOE-induced apoptosis was characterized by activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase (PARP). Moreover, BJOE induced phosphorylation of extracellular-signal regulated kinase (ERK) and inhibited the expression of nuclear factor-kappa B (NF-κB). Conclusions: BJOE exerts a strong tumor-suppressive effect in SiHa cells in vitro and in vivo , likely caused by E6 inhibition and apoptosis induction achieved through the ERK/mitogen-activated protein kinase (MAPK) and NF-κB signaling pathways, supporting potential use of BJOE in cervical cancer treatment.

Nonribosomal peptides (NRPs) and polyketides (PKs) have widely been widely applied in clinical drugs in use today, and one of the main sources for novel NRPs and PKs is soil microbes. However, the diversity of soil bacteria and distribution of their NRPs and PKs biosynthetic genes in different landscapes in extreme environments have not been reported. In this study, 16S rRNA gene fragments from five landscape belts in Changbaishan were analyzed. The results demonstrated that Acidobacteria, Proteobacteria and Chloroflexi accounted for 65% of all bacterial species. Furthermore, the diversities of the PKs and NRPs in the different landscape belts of Changbaishan were compared based on the diversity of gene fragments of the polyketide synthase (PKs) ketosynthase (KS) domain and nonribosomal peptide synthetase (NRPs) adenylation domain (AD). The results showed that NRPs and PKs had highest richness in alpine tundra and birch forest belts, which were negatively correlated with the contents of the available phosphorus, nitrogen, calcium, potassium, and soil organic matter. NRPs and PKs mainly existed in unidentified bacteria, Proteobacteria and Actinobacteria. In addition, a 16S rRNA KEGG pathway analysis showed that the soil microorganisms of Changbaishan have the potential to promote secondary metabolite biosynthesis, resist diseases and regulate immune systems. These combined results suggest that soils of alpine tundra and birch forest belts in Changbaishan may be the main sources for searching the novel antibacterial drugs.

On the basis of the higher order perturbation formulas of g factors for a 4d

Six flavonoid glycosides ( 1 – 3 , 6 – 8 ), one lignan ( 4 ), and one galloyl glycoside ( 5 ) were isolated based on the phytochemical study for the MeOH extract of Polygonum aviculare L. herb. The eight isolated compounds' structures were determined by comparing their physicochemical and spectral data with published ones. Compounds 5 and 6 were first isolated from this plant, and all the compounds were evaluated for DNA topoisomerase inhibitory activities and cytotoxicities. Among the purified compounds, 5 showed stronger inhibitory activity against topoisomerase I with an IC 50 value of 12.0 μM, while the value of positive control camptothecin (CPT) was 17.0 μM. For compounds 1 , 3 , and 5 – 8 , the value ranged from 0.054 to 17.0 µM, suggesting more potent inhibitory activity against topoisomerase II, and that of etoposide (VP-16) was 28.0 µM. Particularly, compounds 6 and 8 (IC 50 = 0.054 and 0.077 µM, respectively) inhibited Topo II about 500 times stronger than VP-16, making them safer agents of DNA topoisomerase. Furthermore, all compounds demonstrated no cytotoxic activity against four cancer cell lines. This study is the first to report the inhibition of DNA topoisomerases of compounds from P. aviculare , suggesting that these compounds may be potential candidates for treating cancer.

An iron-catalyzed C-H functionalization of simple monosubstituted allenes is reported. An efficient protocol for this process was made possible by the use of a newly developed electron-rich and sterically hindered cationic cyclopentadienyliron dicarbonyl complex as the catalyst and N-sulfonyl hemiaminal ether reagents as precursors to iminium ion electrophiles. Under optimized conditions, the use of a mild, functional-group-tolerant base enabled the conversion of a range of monoalkyl allenes to their allenylic sulfonamido 1,1-disubstituted derivatives, a previously unreported and contrasteric regiochemical outcome for the C-H functionalization of electronically unbiased and directing-group-free allenes.

In this study, a bacteriocin PA996 isolated from Pseudomonas azotoformans (P. azotoformans) was purified to homogeneity by ammonium sulphate precipitation and SP-Sepharose column chromatography. P. azotoformans began to grow at 6 h, reached exponential phase at 12-18 h. Bacteriocin PA996 was produced at 18 h and reached a maximum level of 2400 AU/mL. The molecular mass of purified bacteriocin PA996 was estimated by SDS-PAGE and its molecular mass was approximately 50 kDa. By screening in vitro, the bacteriocin PA996 showed an antimicrobial activity against Pasteurella multocida (P. multocida). The bacteriocin PA996 showed antibacterial activity in the range of pH2-10 and it was heat labile. The inhibitory activities were diminished after treatment with proteinase K, trypsin and papain, respectively, while catalase treatment was ineffective. The minimal inhibitory concentration (MIC) and bactericidal kinetics curves showed that the bacteriocin PA996 had a good inhibitory ability against P. multocida. Our data indicate that bacteriocin PA996 could inhibit the growth of P. maltocida and it may have the potential to apply as an alternative therapeutic drug.

Proline-rich antimicrobial peptides (PR-AMPs) have attracted much interest as they target Gram-negative and do not act by lytic mechanisms. In this study, a novel hybrid peptide OM19R was designed based on the Oncocin and MDAP-2. OM19R showed specific and improved potency against Escherichia coli (E. coli), Salmonella and Shigella standard strains compared to parental peptides. The minimum inhibitory concentrations (MICs) ranged from 1 to 2 μM. However, the activity against Klebsiella pneumoniae (K. pneumoniae) was inhibited. The dependence of the SbmA protein for OM19R activity was also studied by a gene-knockout strain. The confocal laser scanning microscopy further revealed that OM19R could rapidly penetrate into E. coli cells without membrane damage. In summary, the hybrid peptide OM19R is a strong cell-selective antibacterial peptide and a promising specific antibacterial agent.

Isolation and characterization of a bacteriocin from Brevibacillus laterosporus DS-3 and its ability in producing antibacterial activity were examined in this study. We isolated 48 bacterial strains from different native ecological niches. Sources included lake water, soil, air, and food. Among the isolates from the soil sample, morphological and biochemical tests identified Brev. laterosporus DS-3, which showed great potential for bacteriocin production. It was purified by ammonium sulfate precipitation, then applied in a Sephadex G-15 gel filtration column connected to a purification of AKTA Pure (USA) and reverse phase chromatography. MALDI-TOF mass spectrometry indicated that bacteriocin DS-3 has a low molecular weight of 1592.579 Da. LNTLETEEWFFK was identified as the sequence by mass spectrometry analysis in tandem liquid chromatography and MASCOT research. This bacteriocin inhibited Gram-positive and Gram-negative bacteria and was effective against Methicillin-resistant Staphylococcus aureus (MRSA). Brev. laterosporus DS-3 present in here is thermostable and tolerant to extreme pH. However, inactivation of its antibacterial activity was observed when treated with papain and trypsin but not pepsin, proteinase K, and catalase.

The present study evaluated the antibacterial activity and mode of action of fibrauretine on Escherichia coli (E. coli) and Staphylococcus aureus, and synergistic effect with kanamycin against multi-drug resistant E. coli. The fibrauretine exhibited inhibitory effect on the growth of the tested bacteria with minimum inhibitory concentration (MIC) and minimum bactericidal concentration of 2.5–5 and 5–10 mg/ml, respectively. Morphological changes of cell microstructure were observed after adding fibrauretine at MIC. The mode of action was further confirmed by measuring release of 260-nm absorbing materials and extracellular potassium ions. Checkerboard dilution test suggested that fibrauretine exhibited synergistic activity when combined with kanamycin (FICI ranging from 0.5625 to 0.625). Our results indicated that fibrauretine exerted synergistic effect with kanamycin and its antibacterial mode of action mainly attributed to disruption of cell membrane integrity.