43 research outputs found
Empirical study of long-range connections in a road network offers new ingredient for navigation optimization models
Navigation problem in lattices with long-range connections has been widely studied to understand the design principles for optimal transport networks; however, the travel cost of long-range connections was not considered in previous models. We define long-range connection in a road network as the shortest path between a pair of nodes through highways and empirically analyze the travel cost properties of long-range connections. Based on the maximum speed allowed in each road segment, we observe that the time needed to travel through a long-range connection has a characteristic time Th ~ 29 min, while the time required when using the alternative arterial road path has two different characteristic times Ta ~ 13 and 41 min and follows a power law for times larger than 50 min. Using daily commuting originādestination matrix data, we additionally find that the use of long-range connections helps people to save about half of the travel time in their daily commute. Based on the empirical results, we assign a more realistic travel cost to long-range connections in two-dimensional square lattices, observing dramatically different minimum average shortest path ā©lāŖ but similar optimal navigation conditions.National Natural Science Foundation (China) (number 51208520)National Natural Science Foundation (China) (number 71071165)New England University Transportation Center (Year 23 grant)NEC Corporation of America (Funding award)Massachusetts Institute of Technology (Solomon Buchsbaum AT&T Research Fund)Central South University of Technology (China) (Shenghua Scholar Program
Visible light responsive titania photocatalysts codoped by nitrogen and metal (Fe, Ni, Ag, or Pt) for remediation of aqueous pollutants
Various cation and nitrogen doped and codoped TiO2 photocatalysts, such as NāTiO2, PtāTiO2, NāFeāTiO2, NāNiāTiO2, NāAgāTiO2 and NāPtāTiO2, were prepared by an acid-catalysed solāgel process. The photocatalysts were characterised by X-ray diffraction (XRD), nitrogen adsorptionādesorption isotherms, UVāvisible diffuse reflectance absorption spectroscopy (UVāvis DRS), and X-ray photoelectron spectroscopy (XPS). The activities of the photocatalysts were evaluated in photodegradation of phenol solutions under simulated sunlight irradiations. A negative effect of some transition metals (iron and nickel) onphotocatalysis was observed on N-metal codoped TiO2, while enhancements in photocatalysis from noble metals (silver and platinum) were obtained. NāPt codoped TiO2 showed a higher activity under UVāvis irradiations than Degussa P25, with an enhancement of 5.9 times higher. The synergistic effect of NāPt-codoping was ascribed to the multivalent states of platinum. In addition, photocatalytic activity of N-, Pt-doped and NāPt-codoped materials were further investigated under visible light irradiations with lambda > 430 nm and lambda > 490 nm. This study therefore demonstrated a promising strategy for design of highly efficient photocatalysts for remediation of aqueous pollutants
Association of ERCC gene polymorphism with osteosarcoma risk
Background: The relationship between ERCC gene polymorphism and
osteosarcoma risk / overall survival of osteosarcoma is still
conflicting, and this meta-analysis was performed to assess these
associations. Material and methods: The association studies were
identified from PubMed, and eligible reports were included and
calculated using meta-analysis method. Results: Four studies were
included for the association of ERCC gene polymorphism with
osteosarcoma risk, and nine studies were recruited into this
meta-analysis for the relationship between ERCC gene polymorphism and
overall survival of osteosarcoma. The meta-analysis indicated that
ERCC1 rs3212986 (8092 C>A) gene polymorphism, ERCC1 rs11615 (19007
T>C) gene polymorphism, ERCC2 rs1799793 (A>G) gene polymorphism,
ERCC2 rs13181 (Lys751Gln) gene polymorphism were not associated with
osteosarcoma risk. ERCC1 rs2298881 (C>A) gene polymorphism, ERCC1
rs3212986 (8092 C>A) gene polymorphism, ERCC1 rs11615 (19007 T>C)
gene polymorphism, ERCC2 rs1799793 (Asp312Asn) gene polymorphism were
not associated with overall survival of osteosarcoma. Interestingly,
ERCC2 rs13181 A allele and GG genotype were associated with overall
survival of osteosarcoma, but AA genotype not (A allele: OR = 0.78, 95%
CI: 0.65-0.93, P = 0.007; GG genotype: OR = 1.32, 95% CI: 1.05-1.65, P
= 0.02; AA genotype: OR = 0.69, 95% CI: 0.45-1.04, P = 0.08).
Conclusion: ERCC2 rs13181 A allele and GG genotype were associated with
overall survival of osteosarcoma
Characterization of viral RNA splicing using whole-transcriptome datasets from host species
RNA alternative splicing (AS) is an important post-transcriptional mechanism enabling single genes to produce multiple proteins. It has been well demonstrated that viruses deploy host AS machinery for viral protein productions. However, knowledge on viral AS is limited to a few disease-causing viruses in model species. Here we report a novel approach to characterizing viral AS using whole transcriptome dataset from host species. Two insect transcriptomes (Acheta domesticus and Planococcus citri) generated in the 1,000 Insect Transcriptome Evolution (1KITE) project were used as a proof of concept using the new pipeline. Two closely related densoviruses (Acheta domesticus densovirus, AdDNV, and Planococcus citri densovirus, PcDNV, Ambidensovirus, Densovirinae, Parvoviridae) were detected and analyzed for AS patterns. The results suggested that although the two viruses shared major AS features, dramatic AS divergences were observed. Detailed analysis of the splicing junctions showed clusters of AS events occurred in two regions of the virus genome, demonstrating that transcriptome analysis could gain valuable insights into viral splicing. When applied to large-scale transcriptomics projects with diverse taxonomic sampling, our new method is expected to rapidly expand our knowledge on RNA splicing mechanisms for a wide range of viruses
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High-throughput monitoring of wild bee diversity and abundance via mitogenomics
1. Bee populations and other pollinators face multiple, synergistically acting threats, which have led to population declines, loss of local species richness and pollination services, and extinctions. However, our understanding of the degree, distribution and causes of declines is patchy, in part due to inadequate monitoring systems, with the challenge of taxonomic identification posing a major logistical barrier. Pollinator conservation would benefit from a high-throughput identification pipeline.
2. We show that the metagenomic mining and resequencing of mitochondrial genomes (mitogenomics) can be applied successfully to bulk samples of wild bees. We assembled the mitogenomes of 48 UK bee species and then shotgun-sequenced total DNA extracted from 204 whole bees that had been collected in 10 pan-trap samples from farms in England and been identified morphologically to 33 species. Each sample data set was mapped
against the 48 reference mitogenomes.
3. The morphological and mitogenomic data sets were highly congruent. Out of 63 total species detections in the morphological data set, the mitogenomic data set made 59 correct detections (93ļæ½7% detection rate) and detected
six more species (putative false positives). Direct inspection and an analysis with species-specific primers suggested that these putative false positives were most likely due to incorrect morphological IDs. Read frequency
significantly predicted species biomass frequency (R2 = 24ļæ½9%). Species lists, biomass frequencies, extrapolated
species richness and community structure were recovered with less error than in a metabarcoding pipeline.
4. Mitogenomics automates the onerous task of taxonomic identification, even for cryptic species, allowing the
tracking of changes in species richness and istributions. A mitogenomic pipeline should thus be able to contain
costs, maintain consistently high-quality data over long time series, incorporate retrospective taxonomic revisions and provide an auditable evidence trail. Mitogenomic data sets also provide estimates of species counts within samples and thus have potential for tracking population trajectories
Effect of angiotensin receptor-neprilysin inhibitor on atrial electrical instability in atrial fibrillation
Background and objectiveAround 33.5 million patients suffered from atrial fibrillation (AF), causing complications and increasing mortality and disability rate. Upstream treatment for AF is getting more popular in clinical practice in recent years. The angiotensin receptor-neprilysin inhibitor (ARNI) is one of the potential treatment options. Our study aimed to investigate the effect of ARNI on atrial electrical instability and structural remodeling in AF.MethodsOur research consisted of two parts ā a retrospective real-world clinical study and an animal experiment on calmness to verify the retrospective founding. In the retrospective study, we reviewed all patients (n = 110) who had undergone the first AF ablation from 1 August 2018 to 1 March 2022. Patients with ARNI (n = 36) or angiotensin II receptor antagonist (ARB) (n = 35) treatment were enrolled. Their clinical data, ultrasound cardiogram (UCG) and Holter parameters were collected before radiofrequency catheter ablation (RFCA) as baseline and at 24-week follow-up. Univariate and multivariate logistic regression analysis were performed. In the animal experiment, we established an AF model (n = 18) on canines by rapid atrial pacing. After the successful procedure of pacing, all the 15 alive beagles were equally and randomly assigned to three groups (n = 5 each): Control group, ARB group, and ARNI group. UCG was performed before the pacing as baseline. Physiological biopsy, UCG, and electrophysiological study (EPS) were performed at 8-week.ResultsClinical data showed that the atrial arrhythmia rate at 24-week was significantly lower in ARNI group compared to ARB group (P < 0.01), and ARNI was independently associated with a lower atrial arrhythmia rate (P < 0.05) at 24-week in multivariate regression logistic analysis. In the animal experiment, ARNI group had a higher atrial electrical stability score and a shorter AF duration in the EPS compared to Control and ARB group (P < 0.05). In the left atrium voltage mapping, ARNI group showed less low voltage and disordered zone compared to Control and ARB group. Compared to Control group, right atrium diameter (RAD), left ventricle end-diastolic volume index (LVEDVI), E/A, and E/Eā² were lower in ARNI group (P < 0.05) at the 8-weeks follow-up, while left atrium ejection fraction (LAEF) and left ventricle ejection fraction (LVEF) were higher (P < 0.01). Compared to ARB group, LVEF was higher in ARNI group at the 8-week follow-up (P < 0.05). ARB and ARNI group had a lower ratio of fibrotic lesions in the left atrium tissues compared to Control group (P < 0.01), but no difference was found between the ARB and the ARNI group.ConclusionARNI could reduce atrial electrical instability in AF in comparison with ARB in both retrospective study and animal experiment
Supported cobalt catalysts by one-pot aqueous combustion synthesis for catalytic phenol degradation
Cobalt oxides (Co) and Al2O3-, SiO2-, and TiO2-supported cobalt oxide catalysts were prepared by anaqueous combustion method using urea and glycine as fuels. Their catalytic performance in activationof OXONE for phenol degradation in aqueous solution was investigated. It was found that unsupported Co oxide and supported Co oxide presented different mechanisms in activation of OXONE for phenol degradation. The supported Co catalysts presented higher activity in activation of OXONE for phenol degradation due to higher dispersion of Co3O4 on the supports and Co(II) coordination sites. The major oxidizing radicals were identified to be SO4- by competitive radical reactions. The Co oxides synthesized from urea or glycine showed a similar activity; however, the supported Co catalysts prepared by glycine fuel exhibited better activity than those prepared by urea. For Al2O3-, SiO2-, and TiO2-supported Co catalysts, Co/TiO2 presented a higher activity in phenol degradation compared with Co/SiO2 and Co/Al2O3. But, Co/SiO2 showed the best stability among the catalysts. Total organic carbon could be reduced by 80%, 72%, and 45% on Co/TiO2, Co/SiO2, and Co/Al2O3, respectively, at 30 ppm phenol. Phenol degradation was found to follow the zero-order kinetics. The causes of deactivation were investigated, and the regeneration methods were proposed
Transvenous left bundle branch pacing during cardiac surgery: A case report
Key Clinical Message Left bundle branch pacing (LBBP) was a promising physiological pacing method, which could prevent or treat heart failure. We reported a young woman with severe valvular disease and heart failure receiving LBBP under direct vision and without xāray assistance during cardiac surgery. To the best of our knowledge, this was the first case report of this type of pace maker implantation