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1.
Curr Microbiol ; 2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-32036395

RESUMO

Alpine permafrost regions are important sources of biogenic CH4 and methanogens play an important role in the methane-producing process. The alpine permafrost on the Qinghai-Tibetan plateau comprises about one-sixth of China's land area, and there are various types of alpine ecosystems. However, the methanogenic communities in the typical alpine ecosystems are poorly understood. In this study, the active layers and permafrost layers of the natural ecosystem of alpine grassland (DZ2-1) and alpine swamp meadow (DZ2-5) were selected to investigate the diversity and abundance of methanogenic communities. Methanobacterium (63.65%) are overwhelmingly dominant in the active layer of the alpine grassland (DZ2-1A). ZC-I cluster (26.13%), RC-I cluster (19.56%), and Methanobacterium (15.02%) are the dominant groups in the permafrost layer of the alpine grassland (DZ2-1P). Methanosaeta (32.92%), Fen cluster (29.59%), Methanosarcina (16.33%), and Methanobacterium (13.95%) are the dominant groups in the active layer of the alpine swamp meadow (DZ2-5A), whereas the Fen cluster (50.85%), ZC-I cluster (27.63%), and RC-I cluster (14.15%) are relatively abundant in the permafrost layer of the alpine swamp meadow (DZ2-5P). qPCR data showed that the abundance of methanogens was higher in the natural ecosystem of alpine swamp meadow than in alpine grassland. We found that the community characteristics of methanogens were related to environmental factors. Pearson correlation analyses indicated that the relative abundance of Methanobacterium had a significantly positive correlation with hydrogen concentration (P < 0.01), while the relative abundances of Methanosaeta and Methanosarcina were positively correlated with acetate concentration (P < 0.05). This study will help us to understand the methanogenic communities and their surrounding environments in alpine ecosystems.

2.
Chem Commun (Camb) ; 56(12): 1899, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32016277

RESUMO

Correction for 'A facile strategy to realize a single/double photon excitation-dependent photosensitizer for imaging-guided phototherapy against HeLa cancer cells at separate irradiation channels' by Lin Kong et al., Chem. Commun., 2020, 56, 571-574.

3.
Rev Sci Instrum ; 91(1): 013706, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32012644

RESUMO

Femoral neck-shaft angle (NSA) is the angle included by the femoral neck axis (FNA) and the femoral shaft axis (FSA), which is a critical anatomic measurement index for evaluating the biomechanics of the hip joint. Aiming at solving the problem that the physician's manual measurement of the NSA is time consuming and irreproducible, this paper proposes a fully automatic approach for evaluating the femoral NSA on radiographs. We first present an improved deep convolutional generative adversarial network to automatically segment the femoral region of interest on radiographs of the pelvis. Then based on the geometrical characteristic of the femoral shape, the FNA and FSA are fitted, respectively, and thus, the NSA can be evaluated conveniently. The average accuracy of the proposed approach for NSA evaluation is 97.24%, and the average deviation is 2.58° as compared to the measurements manually evaluated by experienced physicians. There is no significant statistical difference (P = 0.808) between the manual and automatic measurements, and Pearson's correlation coefficient is 0.904. It is validated that the proposed approach can provide an effective and reliable tool for automatically evaluating the NSA on radiographs.

4.
Molecules ; 25(4)2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32074994

RESUMO

Constructed wetlands (CWs) could achieve high removal efficiency of antibiotics, but probably stimulate the spread of antibiotic resistance genes (ARGs). In this study, four CWs were established to treat synthetic wastewater containing sulfamethoxazole (SMX). SMX elimination efficiencies, SMX degradation mechanisms, dynamic fates of ARGs, and bacterial communities were evaluated during the treatment period (360 day). Throughout the whole study, the concentration of SMX in the effluent gradually increased (p < 0.05), but in general, the removal efficiency of SMX remained at a very high level (>98%). In addition, the concentration of SMX in the bottom layer was higher compared with that in the surface layer. The main byproducts of SMX degradation were found to be 4-amino benzene sulfinic acid, 3-amino-5-methylisoxazole, benzenethiol, and 3-hydroxybutan-1-aminium. Temporally speaking, an obvious increase of sul genes was observed, along with the increase of SMX concentration in the bottom and middle layers of CWs. Spatially speaking, the concentration of sul genes increased from the surface layer to the bottom layer.

5.
Int J Mol Sci ; 21(4)2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32075331

RESUMO

Soybean is an important crop that is grown worldwide. Flowering time is a critical agricultural trait determining successful reproduction and yields. For plants, light and temperature are important environmental factors that regulate flowering time. Soybean is a typical short-day (SD) plant, and many studies have elucidated the fine-scale mechanisms of how soybean responds to photoperiod. Low temperature can delay the flowering time of soybean, but little is known about the detailed mechanism of how temperature affects soybean flowering. In this study, we isolated GmFLC-like from soybean, which belongs to the FLOWERING LOCUS C clade of the MADS-box family and is intensely expressed in soybean leaves. Heterologous expression of GmFLC-like results in a delayed-flowering phenotype in Arabidopsis. Additional experiments revealed that GmFLC-like is involved in long-term low temperature-triggered late flowering by inhibiting FT gene expression. In addition, yeast one-hybrid, dual-luciferase reporter assay, and electrophoretic mobility shift assay revealed that the GmFLC-like protein could directly repress the expression of FT2a by physically interacting with its promoter region. Taken together, our results revealed that GmFLC-like functions as a floral repressor involved in flowering time during treatments with various low temperature durations. As the only the FLC gene in soybean, GmFLC-like was meaningfully retained in the soybean genome over the course of evolution, and this gene may play an important role in delaying flowering time and providing protective mechanisms against sporadic and extremely low temperatures.

6.
Int J Mol Sci ; 21(4)2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-32085472

RESUMO

In roses (Rosa sp.), peduncle morphology is an important ornamental feature. The common physiological abnormality known as the bent peduncle phenomenon (BPP) seriously decreases the quality of rose flowers and thus the commercial value. Because the molecular mechanisms underlying this condition are poorly understood, we analysed the transcriptional profiles and cellular structures of bent rose peduncles. Numerous differentially expressed genes involved in the auxin, cytokinin, and gibberellin signaling pathways were shown to be associated with bent peduncle. Paraffin sections showed that the cell number on the upper sides of bent peduncles was increased, while the cells on the lower sides were larger than those in normal peduncles. We also investigated the large, deformed sepals that usually accompany BPP and found increased expression level of some auxin-responsive genes and decreased expression level of genes that are involved in cytokinin and gibberellin synthesis in these sepals. Furthermore, removal of the deformed sepals partially relieved BPP. In summary, our findings suggest that auxin, cytokinin, and gibberellin all influence the development of BPP by regulating cell division and expansion. To effectively reduce BPP in roses, more efforts need to be devoted to the molecular regulation of gibberellins and cytokinins in addition to that of auxin.

7.
Artigo em Inglês | MEDLINE | ID: mdl-32064707

RESUMO

1,2-Bisphosphines have been identified as one class of important and powerful chiral ligands in asymmetric catalysis with transition metals. Herein, a copper(I)-catalyzed asymmetric hydrophosphination of α,ß-unsaturated phosphine sulfides was developed with the assistance of "soft-soft interaction" between copper(I)-catalyst and the phosphine sulfide moiety, which afforded 1,2-bisphosphine derivatives with diversified electronic nature and steric hindrance in high to excellent yields with high to excellent enantioselectivity. Moreover, the challenging catalytic asymmetric hydrophosphination/protonation reaction was achieved with excellent enantioselectivity. Strikingly, the dynamic kinetic resolution of racemic diarylphosphines was also successfully carried out with high to excellent diastereo- and enantioselectivities. Interestingly, the nucleophilic copper(I)-diphenylphosphide species was characterized by 31 P NMR spectrum and mass spectrum. At last, three products were transformed to chiral 1,2-bisphosphines, which were employed as ligands in Rh-catalyzed asymmetric hydrogenation of α-amino-α,ß-unsaturated ester. The α-amino acid derivative was produced in high enantioselectivity, which demonstrated the utility of the present methodology.

8.
Sci Total Environ ; 713: 136621, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32019018

RESUMO

The dissemination of antibiotic resistance mediated by horizontal transfer of antibiotic resistance genes (ARGs) is exacerbating the global antibiotic crisis. Currently, little is known about whether non-antibiotic, anti-microbial (NAAM) chemicals are associated with the dissemination of ARGs in the environment. In this study, we aimed to evaluate whether a ubiquitous NAAM chemical, triclosan (TCS), is able to promote the transformation of plasmid-borne antibiotic resistance genes (ARGs). By using the plasmid pUC19 carrying ampicillin resistance genes as the extracellular ARG and a model microorganism Escherichia coli DH5ɑ as the recipient, we found that TCS at environmentally detected concentrations (0.2 µg/L to 20 µg/L) significantly enhanced the transformation of plasmid-borne ARGs into E. coli DH5ɑ for up to 1.4-fold. The combination of phenotypic experiments, genome-wide RNA sequencing and proteomic analyses revealed that TCS exposure stimulated the reactive oxygen species (ROS) production for 1.3- to 1.5-fold, induced bacterial membrane damage and up-regulated the translation of outer membrane porin. Moreover, general secretion system Sec (1.4-fold), twin arginine translocation system Tat (1.2-fold) and type IV pilus secretion systems (2.5-fold) were enhanced by TCS, which might contribute to the DNA searching/capture by pilus. Together, TCS might increase the transformation frequency of ARGs into E. coli DH5ɑ by ROS over-production, damaging cell membrane barrier, mediating the pilus capture of plasmid and the translocation of plasmid via cell membrane channels. This study reports that TCS could accelerate the transformation of extracellular ARGs to competent bacteria at environmentally relevant concentrations. The findings advance our understanding of the fate of ARGs in ecosystems and call for risk assessments of NAAM chemicals on disseminating antibiotic resistance.

9.
Int J Mol Sci ; 21(4)2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32054061

RESUMO

This study aimed to show the α-L-Hexaguluroic acid hexasodium salt (G6) protective effect against UVA-induced photoaging of human keratinocyte cells. We found that G6 localized to the mitochondria and improved mitochondrial functions. G6 increased respiratory chain complex activities, which led to increased cellular ATP content and NAD+/NADH ratio. Thus, G6 alleviated the oxidative stress state in UVA-irradiated cells. Moreover, G6 can regulate the SIRT1/pGC-1α pathway, which enhanced the cells' viability and mitochondria energy metabolism. Notably, the anti-photoaging potential of G6 was directly associated with the increased level of MMP and SIRT1, which was followed by the upregulation of pGC-1α, D-LOOP, and Mt-TFA, and with the transcriptional activation of NRF1/NRF2. Taking all of the results together, we conclude that G6 could protect HaCaT cells from UVA-induced photo-aging via the regulation of mitochondria energy metabolism and its downstream signaling pathways.

10.
Cell Commun Signal ; 18(1): 23, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32046726

RESUMO

BACKGROUND: Porcine circovirus type 2 (PCV2) is the causative agent of postweaning multisystemic wasting syndrome, and is associated with a number of other diseases. PCV2 is widely distributed in most developed swine industries, and is a severe economic burden. With an eye to developing an effective, safe, and convenient vaccine against PCV2-associated diseases, we have constructed a recombinant Bacillus subtilis strain (B. subtilis-Cap) that expresses the PCV2 capsid protein (Cap). METHODS: Electroporation of a plasmid shuttle vector encoding the PCV2 Cap sequence was use to transform Bacillus subtilis. Flow cytometry was used to evaluate in vitro bone marrow derived dendritic cell (BM-DC) maturation and T cell proliferation induced by B. subtilis-Cap. Orally inoculated piglets were used for in vivo experiments; ELISA and western blotting were used to evaluate B. subtilis-Cap induced PCV2-specific IgA and IgG levels, as well as the secretion of cytokines and the expression of Toll-like receptor 2 (TLR2) and Toll-like receptor 9 (TLR9). RESULTS: We evaluated the immune response to B. subtilis-Cap in vitro using mouse BM-DCs and in vivo using neonatal piglets orally inoculated with B. subtilis-Cap. Our results showed that the recombinant B. subtilis-Cap activated BM-DCs, significantly increased co-stimulatory molecules (CD40 and CD80) and major histocompatibility complex II, and induced allogenic T cells proliferation. Piglets immunized with B. subtilis-Cap had elevated levels of PCV2-specific IgA in the mucosal tissues of the digestive and respiratory tract, and PCV2-specific IgG in serum (P < 0.05 or P < 0.01). Ileal immunocompetent cells, such as the IgA-secreting cells (P < 0.01), intestinal intraepithelial lymphocytes (IELs) (P < 0.01), CD3+ T lymphocytes (P < 0.01) and CD4+ T lymphocytes (P < 0.01) increased significantly in the B. subtilis-Cap immunized piglets. Additionally, B. subtilis-Cap inoculation resulted in increased the expression of TLR2 and TLR9 (P < 0.01), and induced the secretion of cytokines IL-1ß, IL-6, interferon-γ, and ß-defensin 2 (P < 0.01). CONCLUSIONS: We constructed a prototype PCV2 vaccine that can be administered orally and elicits a more robust humoral and cellular immunity than inactivated PCV2. B. subtilis-Cap is a promising vaccine candidate that is safe, convenient, and inexpensive. Further in vivo research is needed to determine its full range of efficacy in pigs.

11.
Sci Total Environ ; 717: 137081, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32070891

RESUMO

Cadmium (Cd) is a well-known environmental pollutant and can damage fish. MicroRNAs (miRNAs) can involve in inflammation and immunosuppression. However, the mechanisms of miRNAs are still unclear in common carp (Cyprinus carpio L.) treated by Cd. In current study, 54 juvenile common carp were randomly divided into the control group and the Cd group (0.26 mg L-1 Cd) and were cultured for 30 days. The results revealed inflammatory damage in the spleens of common carp after Cd exposure using morphological construction. There were 23 differentially expressed miRNAs including 17 up-regulated differentially expressed miRNAs (miR-1-4-3p, miR-7-1-5p, miR-7-2-5p, miR-10-43-5p, miR-34-3-5p, miR-128-4-3p, miR-128-5-3p, miR-132-2-5p, miR-132-6-5p, miR-216-3-5p, miR-216-4-5p, miR-375-2-3p, miR-375-4-3p, miR-375-5-3p, miR-375-7-3p, miR-375-8-3p, and miR-724-5p) and 6 down-regulated differentially expressed miRNAs (miR-9-6-5p, miR-25-9-3p, miR-31-3-5p, miR-31-12-5p, miR-103-5-5p, and miR-122-1-3p). The 23 miRNAs regulated 2022 target mRNAs. There were 10 pathways and 9 annotation clusters on 2022 target mRNAs using KEGG and GO analysis, respectively. Among them, 5 pathways (NF-κB signaling pathway, Jak-STAT signaling pathway, MAPK signaling pathway, Th1 and Th2 cell differentiation, and Toll-like receptor signaling pathway) and 7 GO terms (negative regulation of immune system process, T cell mediated immunity, regulation of immune response, inflammatory response, positive regulation of inflammatory response, regulation of inflammatory response, and inflammasome complex) were associated with inflammatory response and immunosuppression. miR-375-4-3p, NF-κB, COX-2, PTGES, and IL-4/13A increased and miR-31-12-5p, miR-9-6-5p, MMP9, IL-11, SPI1, and T-Bet decreased using transcriptome sequencing and RT-qPCR in Cd-treated common carp spleens, which revealed that our results were reliable. Our data indicated that miRNAs mediated inflammation-immunosuppressive injury caused by Cd in common carp spleens using whole transcriptome-based miRNA-mRNA network analysis. Our study provided new insights into the toxicology of Cd exposure.

12.
J Neuroradiol ; 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32035971

RESUMO

BACKGROUND AND PURPOSE: The aim of the study was to evaluate whether leukoaraiosis (LA) severity is associated with earlier neurological outcome in acute stroke patients undergoing mechanical thrombectomy. MATERIALS AND METHODS: In this retrospective multicenter study, we evaluated 273 acute stroke patients treated with mechanical thrombectomy. LA severity was graded as 0-2 (absent-to-moderate) versus 3-4 (severe) according to the van Swieten scale. The main clinical outcome was the proportion of early neurological improvement and early neurological deterioration. Early neurological improvement was defined as a decrease of≥4 points on the NIHSS, or an NIHSS score of zero 24hours after baseline assessment. Early neurological deterioration was defined as an increase of≥4 points on the NIHSS 24hours after baseline assessment. RESULTS: There was a significantly lower early neurological improvement rate (17.1% versus 39.2%; P=0.006) and non-significantly higher early neurological deterioration rate (29.3% versus 17.7%; P=0.084) in patients with severe LA (sLA) compared with patients with absent-to-moderate LA. In multivariable analysis, sLA was inversely associated with early neurological improvement (OR, 0.31; 95% CI, 0.13-0.78; P=0.012). There was no significant association of sLA with early neurological deterioration. However, in patients without symptomatic intracranial hemorrhage, sLA was an independent predictor of early neurological deterioration (OR, 2.65; 95% CI, 1.09-6.45; P=0.032). CONCLUSIONS: sLA is a significant negative predictor of early neurological improvement and is an independent predictor of early neurological deterioration in patients without symptomatic intracranial hemorrhage.

13.
Artigo em Inglês | MEDLINE | ID: mdl-31945707

RESUMO

Some previous studies have demonstrated that Herba Lysimachiae (HL) has a certain protective effect on synovial lesion. But the synovial diseases HL is suitable for treating have remained unclear, as well as the mechanisms involved. To investigate the therapeutic potentials of HL in synovial diseases based on the biolabel-led research pattern. Label-free quantitative proteomics analysis was used to screen the potential biolabels responsible for the intervention of HL on synovium. The effects of HL on the joint swelling and synovial platelet aggregation in osteoarthritis model was applied to confirm the biolabels analysis results. Totally, 140 common proteins were differentially expressed after treatment with HL, out of which 23 were involved in 4 key pathways and considered as the potential biolabels responsible for the interventions of HL on synovium. Biolabels analysis showed that HL increased the levels of the proteins promoting platelet aggregation in physiological situations. The potential biolabels and their related pathways were mainly associated with the pathogenesis of osteoarthritis. In osteoarthritis model, HL inhibited the joint swelling and the overexpression of Itga2b and Itgb3 in synovium to some extent. This study reveals that HL is suitable to treat osteoarthritis. Additionally, HL may produce the dual effects on platelet aggregation in synovium.

14.
Chem Commun (Camb) ; 56(11): 1749-1752, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-31942911

RESUMO

Magnesium doped ultra-fine RuO2 nanoparticles are prepared by a one-step annealing of Ru-exchanged Mg-MOF-74. Mg-RuO2 exhibits excellent oxygen evolution reaction performance with a low overpotential of 228 mV at 10 mA cm-2. The excellent performance is attributed to the altered electronic structure and the optimized surface atomic arrangement.

15.
Talanta ; 210: 120586, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31987199

RESUMO

Monodisperse cross-linked poly (styrene-divinylbenzene) (P(S-DVB)) porous microspheres with a particle size of about 10 µm were obtained by using the improved two-step seed swelling polymerization method. The influence of different crosslinking degree on specific surface area of porous microparticles was carefully investigated. The surface morphology and pore structure of seed microspheres and porous microspheres were characterized by scanning electron microscopy (SEM), accelerated surface area and porosimetry analyzer. Porous P(S-DVB) microparticles were sulfonated and used as a hydrophilic column packing material for high performance liquid chromatography (HPLC). The separation of oxalic acid, formic acid, acetic acid and acrylic acid was achieved by using the sulfonated-P(S-DVB) particles as packing materials in HPLC. The back pressure of sulfonated-P(S-DVB) column could be maintained at especially low level even at high flow rates due to the excellent permeability of the fillers. Moreover, the separation of chiral drugs was successfully carried out by using the chitosan coated sulfonated-P(S-DVB) microspheres as a column packing material in HPLC. By using water soluble non-toxic photosensitive diazoresin (DR) as linker, a green and facile way to modify packing materials was developed.

16.
Medicine (Baltimore) ; 99(2): e18623, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31914042

RESUMO

BACKGROUND: The surgical management of acute malignant left-sided bowel obstruction is associated with high morbidity and mortality. Recently, transanal drainage tubes (DTs) and metallic stents (MSs) used as a "bridge to surgery" have become widely used decompression methods compared with emergency surgery. This study aims to evaluate the efficacy and safety of DTs and MSs for the decompression of acute left-sided malignant colorectal obstruction. METHODS: All studies were acquired from PubMed, Medline, Embase, CNKI and the Cochrane Library. The data were extracted by two of the coauthors independently and were analyzed with RevMan5.3. Mean differences (MDs), odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The Cochrane Collaboration's risk of bias tool and the Newcastle-Ottawa scale were used to assess the risk of bias. RESULTS: Eleven studies, which included three randomized controlled trials (RCTs) and 8 observational studies, were assessed. The methodological quality of the trials ranged from low to moderate. The pooled results of the technical success rate showed that the difference was not statistically significant between the2 devises. The differences in clinical success rate, operative time and complications were statistically significant between MSs and DTs, and MSs were associated with a better clinical success rate, increased operative time and fewer complications. Sensitivity analysis proved the stability of the pooled results, and the publication bias was low. CONCLUSION: MS insertion for acute left-sided malignant bowel obstruction is effective and safe with a better technical success rate and with fewer complications than decompression using a DT, and MS insertion can avoid stoma formation. Moreover, MS insertion appears to be a useful treatment strategy for malignant colonic obstruction even if the lesion is located in the right colon. More large-sample, multicenter, high-quality RCTs are needed to verify the outcomes of this meta-analysis.


Assuntos
Neoplasias Colorretais/complicações , Drenagem/instrumentação , Obstrução Intestinal/etiologia , Obstrução Intestinal/cirurgia , Stents , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia
17.
Cell Adh Migr ; 14(1): 12-23, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31942821

RESUMO

In this study, we aimed to study the effect of fluid shear stress on fibroblasts and BMSCs on plane and groove topographies. The results showed that 0.6-Hz stress had the greatest influence on the alignment, polarity, migration and adhesion of fibroblasts on plane by increasing the expression of reoriented actin and vinculin; whereas 1.0-Hz stress promoted differentiation of fibroblasts into myofibroblasts by increasing Col-I and α-SMA expression. Interestingly, under the given frequency stress, the groove structure strengthened the above characteristics of fibroblasts beyond adhesion, and promoted differentiation of BMSCs into myofibroblasts. The above results indicate that 0.6 Hz may improve the implant-tissue sealing, while 1.0-Hz stress probably causes the disordered fiber deposition around implants.

18.
Med Sci Monit ; 26: e919221, 2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31917778

RESUMO

It is well known that cerebrovascular disease has become an important cause of adult death and disability. Strikingly, the Tibet Autonomous Region (TAR) ranks on the top in China for the incidence of stroke. To help explain this phenomenon, we have searched for and analyzed stroke-related literature for the TAR in the past 2 decades and have referenced reports from other regions at similar altitudes. This article focuses on epidemiology features, risk factors, and pathogenesis of stroke in the TAR in an effort to generate a better understanding of the characteristics of stroke in this region. The special plateau-related factors such as its high elevation, limited oxygen, the high incidence of hypertension, smoking, and the unique dietary habits of the region are correlated with the high incidence of stroke. In addition to these factors, the pathogenesis of stroke in this high-altitude area is also unique. However, there is no established explanation for the unique occurrence and high incidence of stroke in the TAR. Our study provides an important rationale not only for the clinic to prevent and treat this disease, but also for the government to develop appropriate health policies for the prevention of stroke in the TAR.

19.
J Am Chem Soc ; 142(5): 2355-2363, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31934768

RESUMO

Solid-binding peptides (SBPs) recognizing inorganic and synthetic interfaces have enabled a broad range of materials science applications and hold promise as adhesive or morphogenetic control units that can be genetically encoded within desirable or designed protein frameworks. To date, the underlying relationships governing both SBP-surface and SBP-SBP interactions and how they give rise to different adsorption mechanisms remain unclear. Here, we combine protein engineering, surface plasmon resonance characterization, and molecular dynamics (MD) simulations initiated from Rosetta predictions to gain insights on the interplay of amino acid composition, structure, self-association, and adhesion modality in a panel of variants of the Car9 silica-binding peptide (DSARGFKKPGKR) fused to the C-terminus of superfolder green fluorescent protein (sfGFP). Analysis of kinetics, energetics, and MD-predicted structures shows that the high-affinity binding of Car9 to the silanol-rich surface of silica is dominated by electrostatic contributions and a spectrum of several persistent interactions that, along with a high surface population of bound molecules, promote cooperative interactions between neighboring SBPs and higher order structure formation. Transition from cooperative to Langmuir adhesion in sfGFP-Car9 variants occurs in concert with a reduction of stable surface interactions and self-association, as confirmed by atomic force microscopy imaging of proteins exhibiting the two different binding behaviors. We discuss the implications of these results for the de novo design of SBP-surface binding systems.

20.
Ecol Appl ; 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31985123

RESUMO

Organic farming has been praised for many profound reasons, but there are some negative effects of organic practices. Research on the interactions between soil insect pests and organic farming practices is still scarce, although such interactions might sometimes lead to severe crop damage. Here, we explore the influences of organic farming inputs and key host crops on the oviposition behaviour of soil insect pests likely to infest crops. We also shed light on the factors driving this behaviour and analyse 4 years of data from an on-farm investigation. Our study offers clear support that decomposing organic matter and legume crops affect oviposition behaviour and provides evidence that butyric acid and 1-hexanol are major attractants. The results suggest that poor management or returning decomposing organic matter to the field is risky. The silver lining, however, is that oviposition behaviour can be disrupted by the identified key attractants to benefit crop protection.

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