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A series of novel benzimidazolyl tetrahydroprotoberberines were conveniently designed and efficiently synthesized from berberine via direct cyclization of tetrahydroprotoberberine ...aldehyde and o-phenylene diamines under metal-free aerobic oxidation. All the new compounds were characterized by IR, 1H NMR, 13C NMR and HRMS spectra. The antimicrobial evaluation revealed that the 5-fluorobenzimidazolyl derivative 5b was the most active antibacterial and antifungal molecule with broad spectrum in comparison to Berberine, Chloromycin, Norfloxacin and Fluconazole. It triggered almost no resistance development against MRSA even after 15 passages. Further studies demonstrated that compound 5b could not only effectively interact with Topo IA by hydrogen bonds, but also intercalate into calf thymus DNA and cleave pBR322 DNA, which might be responsible for its powerful bioactivities.
Oxygen reduction reaction (ORR) plays a crucial role in many energy storage and conversion devices. Currently, the development of inexpensive and high-performance carbon-based non-precious-metal ORR ...catalysts in alkaline media still gains a wide attention. In this paper, the mesoporous Fe-N/C catalysts were synthesized through SiO
2
-mediated templating method using biomass soybeans as the nitrogen and carbon sources. The SiO
2
templates create a simultaneous optimization of both the surface functionalities and porous structures of Fe-N/C catalysts. Detailed investigations indicate that the Fe-N/C3 catalyst prepared with the mass ratio of SiO
2
to soybean being 3:4 exhibits brilliant electrocatalytic performance, excellent long-term stability and methanol tolerance for the ORR, with the onset potential and the half-wave potential of the ORR being about 0.890 V and 0.783 V (vs RHE), respectively. Meanwhile, the desired 4-electron transfer pathway of the ORR on the catalysts can be observed. It is significantly proposed that the high BET specific surface area and the appropriate pore-size, as well as the high pyridinic-N and total nitrogen loadings may play key roles in enhancing the ORR performance for the Fe-N/C3 catalyst. These results suggest a feasible route based on the economical and sustainable soybean biomass to develop inexpensive and highly efficient non-precious metal electrochemical catalysts for the ORR.
Although psoriasis occurs worldwide, the prevalence varies considerably between different peoples and regions. In China, a questionnaire-based study was carried out in 1987 and the prevalence of ...psoriasis was found to be 0.12%. Since then, no large-scale, population-based study has been reported.
To obtain the accurate figures for the prevalence of psoriasis in China.
A population-based survey was conducted in 6 cities. The cluster sampling method was used to select communities in each city. The subjects were required to fill out self-reporting questionnaires during a face-to-face interview and also received physical examination by dermatologists.
19,974 subjects were visited and 17,345 completed the questionnaires and received dermatological examination. 102 subjects (0.59%) were found to have psoriasis. After standardization, the prevalence of psoriasis was 0.47%. The prevalence of psoriasis in males and females was 0.54% and 0.44% respectively. 97.06% of the patients had psoriasis vulgaris. 28.43% of the patients reported a family history of psoriasis. 59.80% of patients experienced a negative influence on the quality of life.
This population-based and dermatologist-confirmed study showed that the prevalence of psoriasis in China is 0.47%, which is higher than that reported in 1987.
Marine bacterial alginate lyases play a role in marine alginate degradation and carbon cycling. Although a large number of alginate lyases have been characterized, reports on alginate lyases with ...special characteristics are still rather less. Here, a gene alyPM encoding an alginate lyase of polysaccharide lyase family 7 (PL7) was cloned from marine Pseudoalteromonas sp. SM0524 and expressed in Escherichia coli. AlyPM shows 41% sequence identity to characterized alginate lyases, indicating that AlyPM is a new PL7 enzyme. The optimal pH for AlyPM activity was 8.5. AlyPM showed the highest activity at 30°C and remained 19% of the highest activity at 5°C. AlyPM was unstable at temperatures above 30°C and had a low T m of 37°C. These data indicate that AlyPM is a cold-adapted enzyme. Moreover, AlyPM is a salt-activated enzyme. AlyPM activity in 0.5-1.2 M NaCl was sixfolds higher than that in 0 M NaCl, probably caused by a significant increase in substrate affinity, because the K m of AlyPM in 0.5 M NaCl decreased more than 20-folds than that in 0 M NaCl. AlyPM preferably degraded polymannuronate and mainly released dimers and trimers. These data indicate that AlyPM is a new PL7 endo-alginate lyase with special characteristics.
An efficient olefination protocol for the oxidative dehydrogenation of phenols and acrylates has been achieved using a palladium catalyst and O2 as the sole oxidant. This reaction exhibits high ...regio- and stereo-selectivity (E-isomers) with moderate to excellent isolated yields and a wide substrate scope (32 examples) including ethyl vinyl ketone and endofolliculina.
Background:
Mounting evidence has revealed an inverse association between cigarette smoking and the risk of Parkinson’s disease (PD). Meanwhile, cigarette smoking has been found to be associated with ...cognitive impairment in PD patients. However, the neural mechanisms of the association between cigarette smoking and PD are not fully understood.
Objective:
The aim of this study is to explore the neural mechanisms of the association between cigarette smoking and PD.
Methods:
A total of 129 PD patients and 69 controls were recruited from the Parkinson’s Progression Markers Initiative (PPMI) cohort, including 39 PD patients with regular smoking history (PD-S), 90 PD patients without regular smoking history (PD-NS), 26 healthy controls with regular smoking history (HC-S), and 43 healthy controls without regular smoking history (HC-NS). Striatal dopamine transporter (DAT) binding and gray matter (GM) volume of the whole brain were compared among the four groups.
Results:
PD patients showed significantly reduced striatal DAT binding compared with healthy controls, and HC-S showed significantly reduced striatal DAT binding compared with HC-NS. Moreover, smoking and PD showed a significant interaction effect in the left medial prefrontal cortex (mPFC). PD-S showed reduced GM volume in the left mPFC compared with PD-NS.
Conclusion:
The degeneration of dopaminergic neurons in PD results in a substantial reduction of the DAT and dopamine levels. Nicotine may act as a stimulant to inhibit the action of striatal DAT, increasing dopamine levels in the synaptic gap. The inverse alteration of dopamine levels between PD and nicotine addiction may be the reason for the inverse association between smoking and the risk of PD. In addition, the mPFC atrophy in PD-S may be associated with cognitive impairment.
The size distribution of airborne dust particles is an important parameter in the measurement of dust emissions due to wind erosion, and a quantitative and accurate description is necessary. ...Observations regarding the size distribution of airborne dust particles are currently lacking in Tibetan Plateau (TP). This study aims to obtain a dust particle size distribution and compare the difference in spatial distribution at a field site (FS) and two urban observation sites (Minfeng and Hetian), in the north of the TP, under the condition of the dust-days and clear-days. The observation data was collected from 5 July to 4 August, 2019. The mass concentration of dust (PM
20
) was measured with a 10-stage quartz crystal microbalance cascade impactor. The results suggested that 91.9% of the particles were less than 1.4 µm on clear-days, and particles of
d
≥ 1.4 µm increased to 27.2% with the occurrence of the dust events. More than 80% of the airborne dust particles were less than 1.4 µm for each friction velocity. The proportion of
d
< 0.7 µm was the greatest at 3.0 m (above the surface, similarly hereinafter) on dust-days, while the proportion of
d
> 0.7 μm was the greatest at 0.5 m on clear-days. During urban observation, with the occurrence of dust events, the concentration of a particle size greater than 2.5 µm increased most significantly in Minfeng, while the concentration of a particle size less than 0.7 µm increased most significantly in Hetian. Moreover, the proportion of particles with
d
< 0.7 μm had the smallest difference, while the proportion of particles with
d
> 1.4 µm had the most obvious difference among these three sites.
Reproductive dysfunction associated with obesity is increasing among women of childbearing age. Emerging evidence indicates that maternal obesity impairs embryo development and offspring health, and ...these defects are linked to oxidative stress in the ovary and in oocytes. Phycocyanin (PC) is a biliprotein from
Spirulina platensis
that possesses antioxidant, anti-inflammatory, and radical-scavenging properties. Our previous studies have shown that PC can reduce reactive oxygen species (ROS) accumulation in oocytes in D-gal-induced aging mice. Here, at the Institute of Cancer Research (ICR) mice fed a high-fat diet (HFD) to model obesity were used to test the effect of PC on reversing the fertility decline caused by obesity. We observed a significant increase in litter size and offspring survival rates after PC administration to obese mice. Further, we found that PC not only ameliorated the level of ovarian antioxidant enzymes, but also reduced the occurrence of follicular atresia in obese female mice. In addition, the abnormal morphology of the spindle-chromosome complex (SCC), and the abnormal mitochondrial distribution pattern in oocytes both recovered. The obesity-related accumulation of ROS, increased number of early apoptotic cells, and the abnormal expression of H3K9me3 in oocytes were all partially reversed after PC administration. In summary, this is the first demonstration that PC can improve fertility by partially increasing ovarian and oocyte quality in obese female mice and provides a new strategy for clinically treating obesity-related infertility in females.
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•65 plastomes were used to explore structural evolution and phylogenetic relationships.•Only two autotrophic species exhibited loss and/or pseudogenization of ndh genes.•Extreme IR ...expansion and SSC contraction in Hetaeria oblongifolia.•Phylogenetic trees resulted in high support, and five subclades were recovered.•Goodyera and Hetaeria are polyphyletic, but nomenclatural revision remain unresolved.
Goodyerinae are one of phylogenetically unresolved groups of Orchidaceae. The lack of resolution achieved through the analyses of previous molecular sequences from one or a few markers has long confounded phylogenetic estimation and generic delimitation. Here, we present large-scale phylogenomic data to compare the plastome structure of the two main clades (Goodyera and Cheirostylis) in this subtribe and further adopt two strategies, combining plastid coding sequences and the whole plastome, to investigate phylogenetic relationships. A total of 46 species in 16 genera were sampled, including 39 species in 15 genera sequenced in this study. The plastomes of heterotrophic species are not drastically reduced in overall size, but display a pattern congruent with a loss of photosynthetic function. The plastomes of autotrophic species ranged from 147 to 165 kb and encoded from 132 to 137 genes. Three unusual structural features were detected: a 1.0-kb inversion in the large single-copy region of Goodyera schlechtendaliana; the loss and/or pseudogenization of ndh genes only in two species, Cheirostylis chinensis and C. montana; and the expansion of inverted repeat regions and contraction of small single-copy region in Hetaeria oblongifolia. Phylogenomic analyses provided improved resolution for phylogenetic relationships. All genera were recovered as monophyletic, except for Goodyera and Hetaeria, which were each recovered as non-monophyletic. Nomenclatural changes are needed until the broader sampling and biparental inherited markers. This study provides a phylogenetic framework of Goodyerinae and insight into plastome evolution of Orchidaceae.
This paper reports a study on the reconstruction of broken Si-O-Si bonds in iron ore tailings (IOTs) in concrete. Limestone and IOTs were used to investigate the influence of different types of ...coarse aggregates on the compressive strengths of concrete samples. The differences in interfacial transition zones (ITZs) between aggregate and paste were analyzed by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Meanwhile, X-ray diffraction (XRD) and infrared spectroscopy (IR) were used to study microscopic changes in limestone and IOTs powders in a simple alkaline environment that simulated cement. The results show that the compressive strengths of IOTs concrete or paste are higher than those of limestone concrete or paste under identical conditions. The Ca/Si atom ratios in the ITZs of IOTs concrete samples are lower than those of limestone concrete; the diffraction peak of the calcium silicate phase at 2
θ
= 29.5°, as well as the bands of Si-O bonds shifting to lower wavenumbers, indicates reconstruction of the broken Si-O-Si bonds on the surfaces of IOTs with Ca(OH)
2
.
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