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1.
Sensors (Basel) ; 19(21)2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31671727

RESUMO

In view of the time-varying complexity of the heat source for the ball screw feed system, this paper proposes an adaptive inverse problem-solving method to estimate the time-varying heat source and temperature field of the feed system under working conditions. The feed system includes multiple heat sources, and the rapid change of the moving heat source increases the difficulty of its identification. This paper attempts to develop a numerical calculation method for identifying the heat source by combining the experiment with the optimization algorithm. Firstly, based on the theory of heat transfer, a new dynamic thermal network model was proposed. The temperature data signal and the position signal of the moving nut captured by the sensors are used as input to optimize the solution of the time-varying heat source. Then, based on the data obtained from the experiment, finite element software parametric programming was used to optimize the estimate of the heat source, and the results of the two heat source prediction methods are compared and verified. The other measured temperature points obtained by the experiment were used to compare and verify the inverse method of this numerical calculation, which illustrates the reliability and advantages of the dynamic thermal network combined with the genetic algorithm for the inverse method. The method based on the on-line monitoring of temperature sensors proposed in this paper has a strong application value for heat source and temperature field estimation of complex mechanical structures.

2.
Aging (Albany NY) ; 112019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31672930

RESUMO

BACKGROUND: Numerous patients with clear cell renal cell carcinoma (ccRCC) experience drug resistance after immunotherapy. Regulatory T (Treg) cells may work as a suppressor for anti-tumor immune response. PURPOSE: We performed bioinformatics analysis to better understand the role of Treg cells in ccRCC. RESULTS: Module 10 revealed the most relevance with Treg cells. Functional annotation showed that biological processes and pathways were mainly related to activation of the immune system and the processes of immunoreaction. Four hub genes were selected: LCK, MAP4K1, SLAMF6, and RHOH. Further validation showed that the four hub genes well-distinguished tumor and normal tissues and were good prognostic biomarkers for ccRCC. CONCLUSION: The identified hub genes facilitate our knowledge of the underlying molecular mechanism of how Treg cells affect ccRCC in anti-tumor immune therapy. METHODS: The CIBERSORT algorithm was performed to evaluate tumor-infiltrating immune cells based on the Cancer Genome Atlas cohort. Weighted gene co-expression network analysis was conducted to explore the modules related to Treg cells. Gene Ontology analysis and pathway enrichment analysis were performed for functional annotation and a protein-protein interaction network was built. Samples from the International Cancer Genomics Consortium database was used as a validation set.

3.
J Biol Chem ; 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31685661

RESUMO

Nuclear modifier genes have been proposed to modify the phenotypic expression of mitochondrial DNA mutations. Using a targeted exome sequencing approach, here we found that the p.191Gly>Val mutation in mitochondrial tyrosyl-tRNA synthetase 2 (YARS2) interacts with the tRNASer(UCN) 7511A>G mutation in causing deafness. Strikingly, members of a Chinese family bearing both YARS2 p.191Gly>Val and m.7511A>G mutations displayed much higher penetrance of deafness than those pedigrees carrying only the m.7511A>G mutation. The m.7511A>G mutation changed the A4:U69 base pairing to G4:U69 pairing at the aminoacyl acceptor stem of tRNASer(UCN) and perturbed tRNASer(UCN) structure and function, including an increased melting temperature, altered conformation, instability, and aberrant aminoacylation of mutant tRNA. Using lymphoblastoid cell lines derived from symptomatic and asymptomatic members of these Chinese families and control subjects, we show that cell lines harboring only the m.7511A>G or p.191Gly>Val mutation revealed relatively mild defects in tRNASer(UCN) or tRNATyr metabolism, respectively. However, cell lines harboring both m.7511A>G and p.191Gly>Val mutations displayed more severe defective aminoacylations and lower tRNASer(UCN) and tRNATyr levels, aberrant aminoacylation, and lower levels of other tRNAs, including tRNAThr, tRNALys, tRNALeu(UUR), and tRNASer(AGY), than those in the cell lines carrying only the m.7511A>G or p.191Gly>Val mutation. Furthermore, mutant cell lines harboring both m.7511A>G and p.191Gly>Val mutations exhibited greater decreases in the levels of mitochondrial translation, respiration, and mitochondrial ATP and membrane potentials, along with increased production of reactive oxygen species. Our findings provide molecular-level insights into the pathophysiology of maternally transmitted deafness arising from the synergy between tRNASer(UCN) and mitochondrial YARS mutations.

4.
Asian J Androl ; 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31670279

RESUMO

The aim of this study was to investigate the role of seminal plasma miR-210-3p in the impairment of semen quality caused by varicocele. This study included 102 patients whose semen quality was normal when they were diagnosed with varicocele. A 2-year follow-up for included patients was performed, and they were divided into Group A (semen quality became abnormal) and Group B (semen quality remained normal) according to the results of semen analysis during the follow-up. Semen parameters and seminal plasma miR-210-3p expression were investigated by semen analysis and quantitative real-time polymerase chain reaction, respectively. In vitro experiments with GC-2 cells were performed to explore the role of miR-210-3p in spermatogenic cells. The results of quantitative real-time polymerase chain reaction showed that the level of seminal plasma miR-210-3p in Group A was higher than that in Group B both after 2-year follow-up and when they were diagnosed with varicocele (both P < 0.01). Apoptosis and proliferation assays showed that miR-210-3p induces apoptosis of spermatogenic cells by promoting caspase-3 activation. In conclusion, our study indicated that seminal plasma miR-210-3p induces spermatogenic cell apoptosis by activating caspase-3 in patients with varicocele. Seminal plasma miR-210-3p may be a potential biomarker for predicting impaired semen quality caused by varicocele.

5.
Nurs Health Sci ; 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31698541

RESUMO

Patient empowerment has been shown to have some positive impacts on self-efficacy, self-esteem, and recovery. However, information about the empowerment needs of patients after a percutaneous coronary intervention is scarce. The aim of this study was to develop a Chinese-language instrument to measure empowerment needs of such patients. The initial instrument was generated based on a literature review and interviews with patients after a percutaneous coronary intervention procedure. Content validity was tested with a panel of experts using the Delphi method. In total, 226 patients were recruited for psychometric tests using the revised instrument. Expert authority coefficient was 0.92, and content validity index was 0.95. The internal consistency reliability was demonstrated by Cronbach's α coefficients (0.86 for the total score, 0.66-0.74 for the dimensions). The newly developed 19-item, five-dimension instrument has shown satisfactory validity (face/content validity and construct validity) and internal consistency reliability. The instrument could help clinical nurses who have close contact with patients after a percutaneous coronary intervention to gain a better understanding of their empowerment needs and could help develop appropriate health education to address such needs.

6.
Nat Chem Biol ; 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31611703

RESUMO

Synthetic microbial consortia have an advantage over isogenic synthetic microbes because they can apportion biochemical and regulatory tasks among the strains. However, it is difficult to coordinate gene expression in spatially extended consortia because the range of signaling molecules is limited by diffusion. Here, we show that spatio-temporal coordination of gene expression can be achieved even when the spatial extent of the consortium is much greater than the diffusion distance of the signaling molecules. To do this, we examined the dynamics of a two-strain synthetic microbial consortium that generates coherent oscillations in small colonies. In large colonies, we find that temporally coordinated oscillations across the population depend on the presence of an intrinsic positive feedback loop that amplifies and propagates intercellular signals. These results demonstrate that synthetic multicellular systems can be engineered to exhibit coordinated gene expression using only transient, short-range coupling among constituent cells.

7.
Sheng Li Xue Bao ; 71(5): 705-716, 2019 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-31646324

RESUMO

The aim of the present study was to investigate the differences of the pathological changes and cognitive function after bilateral common carotid artery occlusion (BCCAO) between Sprague-Dawley (SD) and Wistar rats. Male SD and Wistar rats were randomly divided into 2 groups, respectively: sham operated (S-sham and W-sham) and operated (S-BCCAO and W-BCCAO) groups. The survival rate and the rate of loss of pupillary light reflex (PLR) were observed on day 1, 3, 7, 14 and 28 after the operation, and the light-dark box, Y-maze and odor recognition tests were performed to detect cognitive function on day 28 after the operation. HE and Luxol fast blue staining were used to observe the pathological changes of gray matter (hippocampus), white matter (optical tract), optic nerve, and retina. The results showed that the survival rate of the W-BCCAO group was 62.5%, and PLR loss rate was 100%; whereas the survival rate of the S-BCCAO group was 100%, and PLR loss rate was 58.3%. In the W-BCCAO group, percentages of time spent and distance traveled in the light box were more than those in the W-sham group, but there was no statistical significance between the S-BCCAO and S-sham groups. In the S-BCCAO group, the percentages of time spent and distance traveled in the III arm (labyrinth arm) of the Y-maze were less than those in the S-sham group, but no statistical significance was found between the W-BCCAO group and W-sham group. In the S-BCCAO group, the discrimination ratio of the odor recognition task was less than that in the S-sham group, but no statistical significance could be seen between the W-BCCAO and W-sham groups. Ischemic injury was observed in the CA1 area of the hippocampus in the S-BCCAO group, but no readily visible damage was observed in the W-BCCAO group. Ischemic injury of the visual beam and optic nerve was observed in both the S-BCCAO and W-BCCAO groups. Compared with the corresponding sham groups, the S-BCCAO and W-BCCAO groups showed serious retinal damage with significant thinner retina. The ganglion cell layer (GCL), inner plexiform layer (IPL), and outer plexiform layer (OPL) were thinner in the S-BCCAO group, but no statistical significances were shown in the other layers. All the layers, except the outer nuclear layer (ONL), were significantly thinner in the W-BCCAO group. The results indicate that there are differences of the pathological changes in the hippocampus and visual conduction pathway after BCCAO between SD and Wistar rats, and the degree of learning and memory injury was also different, which suggests that the vascular dementia model of different rat strains should be selected according to research purpose.


Assuntos
Encéfalo/patologia , Doenças das Artérias Carótidas/patologia , Artéria Carótida Primitiva/patologia , Cognição , Animais , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-Dawley , Ratos Wistar
8.
Artigo em Inglês | MEDLINE | ID: mdl-31650356

RESUMO

This work presents a novel lipase immobilization method via polylactic acid (PLA) modified by polyethylene glycol (PEG). The immobilization performance of lipase was characterized by SEM and FTIR. The results indicated that lipase from Candida rugosa type VII was successfully immobilized on the biocompatible PLA/PEG film in the presence of 1, 6-hexamethylene diamine and glutaraldehyde. In addition, the presence of 1, 6-hexylenediamime (8%, w/w) could maintain the maximum enzymatic activity. Moreover, the optimum temperature of lipase shifted from 45 to 50 °C after immobilization. The thermal inactivation experiment illustrated that the immobilized lipase retained up to 63% of the original activity after treated at 50 °C in buffer for 120 min, significantly higher than that of the control (33%) (p < 0.05). The optimum pH value of the immobilized lipase shifted from 6.5 to 7.5. Additionally, compared with the free lipase maintaining 23% of its original activity, the immobilized lipase successfully retained up to 70% after 30 days of storage. Furthermore, the immobilized lipase displayed the excellent reusability of 82% after six cycles. In conclusion, the proposed immobilization approach developed can be potentially used as a sustainable alternative for the immobilization of lipases and the utilization of biocompatible polymer. Graphical Abstract.

9.
CNS Neurosci Ther ; 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31651093

RESUMO

AIMS: To explore the relationship between the circulating neutrophil-to-lymphocyte ratio (NLR) and the remote diffusion-weighted imaging lesions (R-DWILs) after spontaneous intracerebral hemorrhage (ICH). METHODS: Consecutive patients with spontaneous ICH were prospectively collected from November 2016 to May 2018 and retrospectively analyzed. We included subjects who presented within 24 hours after symptom onset and were free of detectable infections on admission or in hospital. Blood samples were obtained at 24-48 hours after ICH ictus, while all complete MRI scans were performed at 5-8 days. R-DWILs were defined as focal hyperintensities remote from the site of the ICH or the peri-hematoma regions. NLR was calculated by dividing the absolute neutrophil counts by the absolute lymphocyte counts. Multivariate binary logistic regression models were generated to evaluate the relationship between NLR and R-DWILs. RESULTS: One hundred sixty-three subjects met eligibility criteria (age 62.3 ± 13.6 years, 60.7% males), of whom 31(19.0%) experienced R-DWILs. Higher circulating NLR was documented in patients with R-DWILs. With the best cutoff value of 6.01, elevated NLR was independently associated with the presence of R-DWILs (OR = 3.170, 95% CI 1.306-7.697, P = .011) in the bivariate logistic regression analysis with adjustment for age, sex, atrial fibrillation, previous ischemic stroke/TIA, SBP on admission, hematoma volume, and IVH. CONCLUSIONS: This study provides significant evidence of the association between circulating NLR and R-DWILs in spontaneous ICH patients. Patients with NLR > 6.01 at 24-48 hours after ICH ictus should be paid more attention to when evaluating R-DWILs.

10.
Stem Cell Reports ; 13(4): 642-656, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31564646

RESUMO

Cellular responses to transforming growth factor ß (TGF-ß) depend on cell context. Here, we explored how TGF-ß/nodal signaling crosstalks with the epigenome to promote mesendodermal differentiation. We find that expression of a group of mesendodermal genes depends on both TRIM33 and nodal signaling in embryoid bodies (EBs) but not in embryonic stem cells (ESCs). Only in EBs, TRIM33 binds these genes in the presence of expanded H3K18ac marks. Furthermore, the H3K18ac landscape at mesendodermal genes promotes TRIM33 recruitment. We reveal that HDAC1 binds to active gene promoters and interferes with TRIM33 recruitment to mesendodermal gene promoters. However, the TRIM33-interacting protein p300 deposits H3K18ac and further enhances TRIM33 recruitment. ATAC-seq data demonstrate that TRIM33 primes mesendodermal genes for activation by maintaining chromatin accessibility at their regulatory regions. Altogether, our study suggests that HDAC1 and p300 are key factors linking the epigenome through TRIM33 to the cell context-dependent nodal response during mesendodermal differentiation.

11.
Helicobacter ; : e12656, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31571330

RESUMO

BACKGROUND & AIMS: Developing countries are making efforts to improve health management. Practice deviating from the guideline means inefficient control. The study aims to investigate the management of Helicobacter pylori (H pylori) infection from a developing country perspective. METHODS: An authoritative survey was conducted in 14th (2014) and 17th (2017) Congress of Gastroenterology China, respectively. The Maastricht V/Florence consensus report was invoked as the evaluation criterion. RESULTS: A total of 4182 valid samples were included in this study. Most of the respondents (94%) updated knowledge by lectures. Respondents had a different awareness rate of H pylori-related diseases, ranging from 45% to 95%. Up to 40% of the respondents did not follow the recommendations for the diagnosis. Choice accuracy of eradication regimens and antibiotic combinations was <70%. About 20% of the respondents did not pay attention to the confirmation after the eradication. The situation had been improved in 2017 when compared with that in 2014 (all P < .05). Multivariate logistic regression analysis revealed that influencing factors including nongastroenterologists, bachelor degree and below, the primary professional title, hospital location, and a small proportion of H pylori infection in daily practice related to the deviation of consensus (all P < .05). CONCLUSIONS: Although the management of H pylori infection has been improved in a developing country, there is still a gap between the real-world practices and the consensus. Influencing factors should be taken into account in decision-making, and the corresponding population should be strengthened with precision training during the promotion of the guideline.

12.
Arch Pharm (Weinheim) ; 352(11): e1900129, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31478565

RESUMO

To gain further knowledge of the structure-activity relationship and druggability of novel oxazolidinone-based UDP-3-O-acyl-N-acetylglucosamine deacetylase (LpxC) inhibitors as Gram-negative antibacterial agents, compounds containing the hydrophobic tails with different lengths and terminal substitutions were synthesized and their antibacterial activities against standard and clinically isolated Gram-negative strains were evaluated. We summarized their structure-activity relationships and found that oxazolidinone-based compounds exhibited a narrower antibacterial spectrum compared with threonine-based compounds. Furthermore, we parallelly compared the metabolic stabilities of the compounds with the classic threonine scaffold and the novel oxazolidinone scaffold in liver microsomes. The results indicated that the druggability of the oxazolidinone scaffold may be inferior to the classic threonine scaffold in the design of LpxC inhibitors.

13.
Nat Commun ; 10(1): 4268, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31537811

RESUMO

Atropisomeric biaryl motifs are ubiquitous in chiral catalysts and ligands. Numerous efficient strategies have been developed for the synthesis of axially chiral biaryls. In contrast, the asymmetric construction of o-quinone-aryl atropisomers has yet to be realized. Inspired by the rapid progress of the chemistry of biaryls, here we present our initial investigations about the atroposelective construction of axially chiral arylquinones by a bifunctional chiral phosphoric acid-catalyzed asymmetric conjugate addition and central-to-axial chirality conversion. With o-naphthoquinone as both the electrophile and the oxidant, three types of arylation counterparts, namely 2-naphthylamines, 2-naphthols and indoles, are utilized to assemble a series of atropisomeric scaffolds in good yields and excellent enantioselectivities. This approach not only expands the axially chiral library but also offers a route to a class of potential, chiral biomimetic catalysts.

14.
J Exp Clin Cancer Res ; 38(1): 412, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31547840

RESUMO

BACKGROUND: The transcription factor HOXD9 is one of the members of the HOX family, which plays an important role in neoplastic processes. However, the role of HOXD9 in the growth and metastasis of gastric cancer (GC) remains to be elucidated. METHODS: In vitro functional role of HOXD9 and RURY3 in GC cells was determined using the TMA-based immunohistochemistry, western blot, EdU incorporation, gelatin zymography, luciferase, chromatin Immunoprecipitation (ChIP) and cell invasion assays. In vivo tumor growth and metastasis were conducted in nude mice. RESULTS: HOXD9 is overexpressed in GC cells and tissues. The high expression of HOXD9 was correlated with poor survival in GC patients. Functionally, HOXD9 expression significantly promoted the proliferation, invasion and migration of GC cells. Mechanically, HOXD9 directly associated with the RUFY3 promoter to increase the transcriptional activity of RUFY3. Inhibition of RUFY3 attenuated the proliferation, migration and invasiveness of HOXD9-overexpressing GC cells in vitro and in vivo. Moreover, both HOXD9 and RUFY3 were highly expressed in cancer cells but not in normal gastric tissues, with their expressions being positively correlated. CONCLUSIONS: The evidence presented here suggests that the HOXD9-RUFY3 axis promotes the development and progression of human GC.

15.
Angew Chem Int Ed Engl ; 58(43): 15478-15487, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31464086

RESUMO

Polymerizing epoxides after cyclic esters remains a major challenge, though their block copolymers have been extensively studied and used for decades. Reported here is a simple catalytic approach based on a metal-free Lewis pair that addresses the challenge. When the Lewis acid is used in excess of a base, selective (transesterification-free) polymerization of epoxides occurs in the presence of esters, while selectivity toward cyclic esters is achieved by an oppositely biased catalyst. Hence, one-pot block copolymerization can be performed in both ester-first and ether-first orders with selectivity being switchable at any stage, yielding ether-ester-type block copolymers with unlimited ordering of sequences as well as widely variable compositions and architectures. The selectivity can also be switched back and forth several times to generate a multiblock copolymer. Experimental and calculational results indicate that the selectivity originates mainly from the state of catalyst-activated hydroxy species.

16.
Genet Test Mol Biomarkers ; 23(9): 634-643, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31386584

RESUMO

Aims: Caveolin-1, which is encoded by the caveolin-1 (CAV1) gene, plays an important role in the development of pulmonary hypertension (PH). The purpose of this study was to determine the relationship between 3' untranslated region (UTR) single nucleotide polymorphisms (SNPs) of the CAV1 gene and the risk of PH in Chinese Han patients with chronic obstructive pulmonary disease (COPD). Methods: From March 2016 to October 2018, 235 patients with COPD combined with PH (COPD/PH+) and 240 patients with COPD and without PH (COPD/PH-) were recruited to the study. The CAV1 gene rs1049314, rs8713, rs1049334, rs6867, and rs1049337 loci were genotyped and the plasma hsa-miR-451 and caveolin-1 levels were measured in all subjects. Results: The risk of PH in patients with COPD carrying the C allele of the rs8713 locus was 2.82 times higher than that in A allele carriers (95% confidence interval [CI], 1.94-4.08; p < 0.001). The risk of PH in patients with COPD carrying the T allele of the rs1049337 locus was significantly lower than that in C allele carriers (odds ratio [OR], 0.48; 95% CI, 0.37-0.63; p < 0.001). The ACGAC haplotype was found to be a highly-significant risk factor for COPD combined with PH (OR, 2.24; 95% CI, 1.20-4.17; p = 0.01). Plasma levels of hsa-miR-451 and the caveolin1 protein in patients with the rs8713 C allele were significantly lower than in those with the wild type (WT) allele regardless of PH status. Conversely, the hsa-miRN-451 and caveolin-1 levels in patients with the rs1049337 mutant C allele were significantly higher than those in the WT T allele (p < 0.05). There was a positive correlation between plasma hsa-miR-451 and caveolin-1 levels in patients with COPD/PH+ and COPD/PH- (r = 0.72 and 0.63, respectively). Conclusion: SNPs of the CAV1 gene loci rs8713 and rs1049337 are associated with a risk of PH in COPD patients. The underlying mechanism is likely to be related to the effect of the SNPs on the regulation of caveolin-1 by hsa-miR-451.

17.
Clin Sci (Lond) ; 133(17): 1857-1870, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31467135

RESUMO

Chronic kidney disease (CKD) affects 10-15% of the population worldwide, results in high morbidity and mortality, and requires costly treatment and renal replacement therapy. Glomerulosclerosis, tubulointerstitial fibrosis, and persistent intestinal flora disturbance are common in CKD. Short-chain fatty acids (SCFAs), produced by the intestinal microbiota, have been previously reported to ameliorate kidney injury; however, the specific concentrations and types that are required to improve renal function remain unknown. The present study aims to evaluate the levels of SCFAs in healthy and CKD patients, and to test the hypothesis that SCFAs play a critical role in delaying CKD progression. One hundred and twenty-seven patients with CKD and 63 healthy controls from China were enrolled in the present study. Butyrate, which is considered beneficial to humans, was almost three-times higher in healthy volunteers than that in CKD5 subjects (P=0.001). Moreover, the serum SCFA levels in controls were significantly higher than that in CKD patients (P<0.05), and the butyrate level among CKD5 patients (1.48 ± 0.60 µmol/l) was less than half of that in controls (3.44 ± 2.12 µmol/l, P<0.001). In addition, we observed an inverse correlation between butyrate level and renal function (P<0.05). A CKD rat model transplanted with microbiota obtained from CKD patients exhibited accelerated CKD progression via increased production of trimethylamine N-oxide (TMAO), which was reversed by supplementation with extra butyrate. Our results showed that SCFA levels were reduced in CKD patients and that butyrate supplementation might delay CKD progression.

18.
Ying Yong Sheng Tai Xue Bao ; 30(8): 2682-2690, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31418193

RESUMO

Based on the field investigation data and the integration GIS spatial methods and geographical detector model, we analyzed the main and interactive effects of geographical and social environmental factors on the distribution of invasive plants in Fujian Province, China. The results showed that a total of 82 invasive plant species were recorded, with Compositae as the dominant family. Conyza canadensis, Ageratum conyzoides, and Alternanthera philoxeroides had the highest frequencies. There were more invasive species in coastal areas than in inland areas. Fuzhou and Xiamen were the hot areas for plant invaision. The invasive plants widely distributed at different altitudes, and the invasion reduced with the increasing altitude. The geographical detector analysis showed that rainfall as a natural environment factor and road density and people density as socio-economy factors were the major driving factors for the distribution of invasive plant species. The multi-factor interaction had a positive effect on the spatial distribution of invasive plants, implying the complexity of impact factors on the distribution of invasive plant species. In conclusion, the geographical detector could be used in the studies of invasive plants, and environmental factors could be also applied for monitoring the suitable establishment areas of invasive plants in Fujian Province. Our results provide a scientific basis for effective management of invasive plants.


Assuntos
Espécies Introduzidas , Plantas , Altitude , China , Geografia
19.
Int J Biol Macromol ; 140: 10-16, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31419550

RESUMO

Regenerated chitin (RCh)/poly (lactic acid) (PLA) blends with enhanced properties were successfully prepared via the Pickering emulsion approach. An oil-in-water Pickering emulsion of PLA/dichloromethane (DCM) stabilized with RCh via an ultrasonic homogenizer was formed. A uniformly dispersed blends were obtained upon slow volatilization of DCM. The effects of RCh on physical/morphological, thermal, mechanical and rheology properties of the blends were studied. The introduction of RCh in PLA improved its crystallinity from 23.4% to over 38.0%. The blends displayed an improvement in storage modulus of 393% at 70 °C for 2 wt%RCh as compared with neat PLA. The RCh/PLA blends showed an enhancement in both tensile strength and elongation at break of 18% and 31% respectively at the loading of 1.5 wt%-RCh. Moreover, the complex viscosity of the blends was increased compared to neat PLA, and all the blends exhibited shear-thinning behaviour without any plateau region at low angular frequencies (ω < 10 rad/s). These results suggest that the low weight content RCh introduced to PLA matrix via this facile Pickering emulsion approach not only promotes nucleation in RCh/PLA blends but also acts as a promising reinforcing agent for PLA.

20.
Viruses ; 11(9)2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31461875

RESUMO

The identification of a new circovirus (Porcine Circovirus 3, PCV3) has raised concern because its impact on swine health is not fully known. In Fujian Province in eastern China, even its circulating status and genetic characteristics are unclear. Here, we tested 127 tissue samples from swine from Fujian Province that presented respiratory symptoms. All of the PCV3 positive samples were negative for many other pathogens involved in respiratory diseases like PCV2, PRRSV, and CSFV, suggesting that PCV3 is potentially pathogenic. From phylogenetic analysis, PCV3 strains are divided into two main clades and five sub-clades; PCV3a-1, PCV3a-2, PCV3a-3, PCV3b-1, and PCV3b-2. Our identified strains belong to genotypes PCV3a-1, PCV3a-2, PCV3a-3, and PCV3b-2, indicating a high degree of genetic diversity of PCV3 in Fujian province until 2019. Interestingly, we found the time of the most recent common ancestor (tMRCA) of PCV3 was dated to the 1950s, and PCV3 has a similar evolutionary rate as PCV2 (the main epidemic genotypes PCV2b and PCV2d). In addition, positive selection sites N56D/S and S77T/N on the capsid gene are located on the PCV3 antigen epitope, indicating that PCV3 is gradually adaptive in swine. In summary, our results provide important insights into the epidemiology of PCV3.

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