vB_EcoM-P896 coliphage isolated from duck sewage can lyse both intestinal pathogenic Escherichia coli and extraintestinal pathogenic E. coli.

Pathogenic Escherichia coli strains cause diseases in both humans and animals. The limiting factors to prevent as well as control infections from pathogenic E. coli strains are their pathotypes, serotypes, and drug resistance. Herein, a bacteriophage (vB_EcoM-P896) has been isolated from duck sewage. Furthermore, aside from targeting intestinal pathogenic E. coli strains like enteropathogenic E. coli, Shiga toxin-producing E. coli, entero-invasive E. coli, and enteroaggregative E. coli, vB_EcoM-P896 can cause lysis in extraintestinal pathogenic E. coli strains such as avian pathogenic E. coli. Stability analysis revealed that vB_EcoM-P896 was stable under the following conditions: temperature, 4℃-50℃; pH, 3-11. The sequencing of the vB_EcoM-P896 genome was conducted utilizing an HiSeq system (Illumina, San Diego, CA) and subjected to de novo assembling with the aid of Spades 3.11.1. The characteristics of the DNA genome were as follows: size, 170,656 bp; GC content, 40.4%; the number of putative coding regions, 294. Transmission electron microscopy analysis of morphology and genome analysis revealed that the phage vB_EcoM-P896 belonged to the order Caudovirales and the family Myoviridae. The pan-genome analysis of vB_EcoM-P896 was divided into two levels. The first level involved the analysis of 91 strains of muscle tail phages, which were mainly divided into 5 groups. The second level involved the analysis of 24 strains of myophage with high homology. Of the 1480 gene clusters, 23 were shared core genes. Neighbor-joining phylogenetic trees were constructed using the Poisson model with MEGA6.0 based on the conserved sequences of phage proteins, the amino acid sequence of the terminase large subunit, and tail fibrin. Further analysis revealed that vB_EcoM-P896 was a typical T4-like potent phage with potential clinical applications.

Characteristics and phylogenetic analysis of the complete mitochondrial genome of Erasmia pulchella Hope, 1840 (lepidoptera: zygaenidae).

Erasmia pulchella has brightly colored wings and releases toxic cyanide as a defense against predation. At present, the molecular phylogenetic status of this species is still unclear. Here, we presented the first complete mitochondrial genome of the genus Erasmia, which was assembled from data generated using a genome skimming method. The assembled mitogenome was 15,197 bp in length and consists of 37 genes, including 13 protein-coding genes, two rRNAs, 22 tRNAs, and a control region. Phylogenetic analysis based on both maximum likelihood (ML) and Bayesian inference (BI) revealed that E. pulchella was most closely related to Amesia sanguiflua.

Validation and calibration of aerosol optical depth and classification of aerosol types based on multi-source data over China.

A refined classification of aerosol types is essential to identify and control air pollution sources. This study focused on improving the resolution and accuracy of aerosol optical depth (AOD) and further refining the classification of aerosol types in China. We validated the accuracy of the AOD acquired using the Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA2) and Copernicus Atmosphere Monitoring Service (CAMS) by comparing it with that acquired using from the Aeronet Robotic Network (AERONET). We simulated the AOD with high spatial resolution and accuracy based on the extremely randomized trees (ERT), adaptive boosting (AdaBoost), and gradient boosting decision trees (GBDT) models and identified aerosol types based on the Angstrom Exponent (AE) from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the calibrated AOD. The results showed that CAMS overestimates AOD (21.4 %) and MERRA2 underestimates AOD (-17.3 %). Among the three machine learning models, the ERT model performed best, with a determination coefficient (R2) of 0.825 and the root-mean-square error (RMSE) of 0.174. Biomass burning/urban-industrial aerosols dominated China, with the largest contributions to southern, eastern, and central China in spring and summer. Clean continental aerosols contributed the most to southwestern China in fall and winter, whereas desert dust aerosols contributed the most to northwestern and eastern China in spring.

Assessing public health and economic loss associated with black carbon exposure using monitoring and MERRA-2 data.

Black carbon (BC) exposure in China continues to be relatively high, prompting researchers to assess BC exposure levels using data from monitoring sites, satellite remote sensing, and models. However, data regarding the application of a combined strategy comprising the analysis of monitoring data and various types of data to simulate BC exposure levels are lacking. Hence, the current study seeks to estimate short- and long-term BC exposure levels by combining national monitoring data with data from the second Modern-Era Retrospective analysis for Research and Applications (MERRA-2). Furthermore, this study attempts to improve the spatio-temporal resolution of BC exposure levels using Bayesian maximum entropy (BME). The BME model performed well in terms of estimating short- (R2 = 0.74 and RMSE = 1.76 µg/m3) and long-term (R2 = 0.76 and RMSE = 1.3 µg/m3) exposure. Premature mortalities and economic losses were also assessed by applying localised concentration-response coefficients simulated in China. A total of 74,500 (95% confidence interval (CI): 23,900-124,500) and 538,400 (95% CI: 495,000-581,300) all-cause premature mortality cases were found to be associated with short- and long-term BC exposure, respectively. Meanwhile, short-term BC exposure was associated with economic losses ranging from 7.5 to 13.2 billion US dollars (USD) (1 USD = 6.36 RMB on January 19, 2022) based on amended human capital (AHC) and willingness to pay (WTP), accounting for 0.06%-0.1% of China's total gross domestic product (GDP) in 2017 (1.2 × 104 billion USD), respectively. The economic losses for long-term exposure varied from 53 to 93.2 billion USD based on AHC and WTP, accounting for 0.4%-0.8% of China's total GDP in 2017, respectively.

Descriptions and Barcoding of Five New Chinese Deuterophlebia Species Revealing This Genus in Both Holarctic and Oriental Realms (Diptera: Deuterophlebiidae).

The monotypic family Deuterophlebiidae of China was recorded twice previously from far northwest upon adults, the most parts of this country have not been investigated, leaving a huge blank of knowledge on their morphology, diversity, biology, or distribution. After deliberated collecting and rearing in recent years, we obtained more than one thousand specimens of Deuterophlebiidae, they are classified into five new species herein: Deuterophlebia sinensis sp. nov., D. yunnanensis sp. nov., D. wuyiensis sp. nov., D. acutirhina sp. nov. and D. alata sp. nov. Detailed descriptions and photographs of gathered life stages are given for these new species. Adults of them can be identified by chaetotaxy and length ratio of flagellomeres and legs, microtrichia on postgena and shape of their clypeus, pupae can be recognized by thoracic spines and abdominal chitin bands, and larvae can be separated by setae on thorax and abdomen. Genetic distances between species are 0.086-0.175 based on their COI genes. This contribution represents the first database of the enigmatic Deuterophlebiidae from China and shows a new distribution pattern of Deuterophlebia. In addition, the discovery throws some light on the origin and biogeography of the genus and family.

Comparative Mitogenome Analyses of Subgenera and Species Groups in Epeorus (Ephemeroptera: Heptageniidae).

Epeorus Eaton, 1881 is a diverse mayfly genus in Heptageniidae comprising more than 100 species which are further divided into nine subgenera and several species groups. However, the classification and the phylogenetic relationships among them are still uncertain. Here, 15 complete mitochondrial genomes of Epeorus were sequenced and compared together with six available ones of same genus in the NCBI database. Based on morphological classification, the 21 mitogenomes were classified into six subgenera (Proepeorus, Epeorus s.str., Belovius, Iron, Caucasiron and Siniron) and four species groups (G1, G2, montanus and longimanus). Among all analyzed mitogenomes, the gene rearrangement of trnI-trnM-trnQ-NCR-ND2 was first found occurring in three species of group G1, whereas the gene block trnI-trnM-trnQ-trnM-ND2 was observed in all other mitogenomes of Epeorus. Furthermore, the genetic composition and codon usage of species in group G1 were also significantly different from all other Epeorus species, except group longimanus. The intergenic spacer between trnA and trnR, which has the stem-loop secondary structure, occurred in all 21 mitogenomes, and the sequences of stems and loops were conserved within species groups. Furthermore, the phylogenetic analyses strongly support the monophyly of all species groups, although three of six recognized subgenera Proepeorus, Belovius, and Iron, were shown as the non-monophyletic groups.

The First Two Complete Mitochondrial Genomes of Neoephemeridae (Ephemeroptera): Comparative Analysis and Phylogenetic Implication for Furcatergalia.

Mayflies of the family Neoephemeridae are widespread in the Holarctic and Oriental regions, and its phylogenetic position is still unstable in the group Furcatergalia (mayflies with fringed gills). In the present study, we determined the complete mitogenomes of two species, namely Potamanthellus edmundsi and Pulchephemera projecta, of this family. The lengths of two mitogenomes were 15,274 bp and 16,031 bp with an A + T content of 73.38% and 73.07%, respectively. Two neoephemerid mitogenomes had a similar gene size, base composition, and codon usage of protein-coding genes (PCGs), and the sequenced gene arrangements were consistent with the putative ancestral insect mitogenomes as understood today. The most variable gene of Furcatergalia mitogenomes was ND2, while the most conserved gene was COI. Meanwhile, the analysis of selection pressures showed that ND6 and ATP8 exhibited a relaxed purifying selection, and COI was under the strongest purifying selection. Phylogenetic trees reconstructed based on two concatenated nucleotide datasets using both maximum likelihood (ML) and Bayesian inference (BI) estimations yielded robust identical topologies. These results corroborated the monophyly of seven studied families and supported the family Leptophlebiidae as being of the basal lineage of Furcatergalia. Additionally, the sister-group relationship of Caenidae and Neoephemeridae was well supported. Methodologically, our present study provides a general reference for future phylogenetic studies of Ephemeroptera at the mitogenome level.

The Imaginal Characters of Neoephemera projecta Showing Its Plesiomorphic Position and a New Genus Status in the Family (Ephemeroptera: Neoephemeridae).

The newly collected imaginal materials of the species Neoephemera projecta Zhou and Zheng, 2001 from Southwestern China, which is linking the other genera of the family Neoephemeridae, are described in detail. Nymphs are also photographed for the first time. The morphology of this species shows some characters of the other genera in Neoephemeridae and several autapomorphies. However, most characters can be seen as plesiomorphies of the family. Specifically, the dorsal-oriented fimbriate gills, projected frons and slim labial palpi in nymphs plus large reddishly pigmented wings, many crossveins, 4-segmented forceps with a relatively long basal segment, fused penes and unforked anal vein show that this species is closer to the taxon Fossoriae rather than to the previously considered Potamanthidae. To reflect its primitive position, a new genus, Pulchephemera Zhou gen. n., is established for this species, Pulchephemera projecta comb. n. Its eggs and observed biology are also described.

A hybrid approach to estimating long-term and short-term exposure levels of ozone at the national scale in China using land use regression and Bayesian maximum entropy.

Because ambient ozone (O3) has fine spatial scale variability in addition to a large scale regional distribution, accurate exposure predictions for population health studies need to also capture fine spatial scale differences in exposure. To address these needs, we developed a 3-year average land use regression (LUR) and combined LUR and Bayesian maximum entropy (BME) by incorporating a national area variability LUR model for China from 2015 to 2017 along with data that take into account incompleteness of O3 monitoring data into a BME framework. Spatio-temporal kriging models that either included or did not include "soft" data were used for comparison. The final LUR model included five predictor variables: road length within a 1000 m buffer, temperature, wind speed, industrial land area within a 3000 m buffer and altitude. The 1-year predicted O3 concentrations based on the ratio method moderately agreed with the measured concentration, and the regression R2 values were 0.53, 0.57 and 0.59 in the year of 2015, 2016 and 2017, respectively. The LUR/BME model performed better (R2 = 0.80, root mean squared error [RMSE] = 23.5 µg/m3) than the ordinary spatio-temporal kriging model that either included "soft" data (R2 = 0.57, RMSE = 49.2 µg/m3) or did not include the "soft" data (R2 = 0.52, RMSE = 58.5 µg/m3). We have demonstrated that a hybrid LUR/BME model can provide accurate predictions of O3 concentrations with high spatio-temporal resolution at the national scale in mainland China.

Novel gene rearrangement pattern in the mitochondrial genomes of Torleya mikhaili and Cincticostella fusca (Ephemeroptera: Ephemerellidae).

The mayfly family Ephemerellidae (Insecta: Ephemeroptera) is distributed around the world and has very high species diversity. However, its evolution pattern of mitogenome and phylogenetic relationships within Ephemeroptera remain unclear. In this study, the complete mitochondrial genomes (mitogenomes) of Torleya mikhaili (15,042 bp) and Cincticostella fusca (15,135 bp) were firstly determined and analyzed. Two ephemerellid mitogenomes shared similar gene organization with 37 typical genes as well as a putative control region. Compared with other reported mitogenomes of mayflies, the unique gene order (I'-CR-Q-M) was found in these two mitogenomes. Although the observed rearrangement pattern is novel within ephemeropteran mitogenomes, it could be explained presumably by the mechanisms of tandem duplication-random loss and recombination. The phylogenetic analyses using both Bayesian inference (BI) and maximum likelihood (ML) methods based on four nucleotide datasets placed three ephemerellid species together. Furthermore, the phylogenetic relationships of the three genera were recovered as ((Ephemerella + Cincticostella) + Torleya).

Estimation of health and economic benefits based on ozone exposure level with high spatial-temporal resolution by fusing satellite and station observations.

In recent years, ozone pollution has become more and more serious in China. Several epidemiological studies have demonstrated the correlation between short-term ozone exposure and several health risks including all-cause mortality, cardiovascular mortality, and respiratory mortality. In this study, the daily ozone exposure levels with 10 km × 10 km resolution were estimated based on satellite data derived from Ozone Monitoring Instrument (OMI) and the monitoring data. The health impacts for potential decrease in the daily ozone concentration and the corresponding economic benefits in 2016 were estimated by applying the environmental Benefits Mapping and Analysis Program-Community Edition (BenMAP-CE) model. By reducing the daily maximum 8-h average concentration of ozone to 100 µg/m3, the estimated avoided all-cause mortalities were 120 × 103 (95% confidence interval (CI): 67 × 103, 160 × 103) cases and the correspondingly economic benefits ranged from 36 to 64 billion CNY using amended human capital (AHC) and willingness to pay (WTP) method in 2016. If the daily maximum 8-h average concentration of ozone were rolled back to 70 µg/m3, the estimated avoided all-cause mortalities were 160 × 103 (95% CI: 98 × 103, 230 × 103) cases and economic benefits ranged from 54 to 95 billion CNY based on AHC and WTP methods.

The effects of extended π-conjugation in bipyridyl ligands on the tunable photophysics, triplet excited state and optical limiting properties of Pt(ii) naphthalimidyl acetylide complexes.

Pt(ii) complexes that exhibit long-lived triplet excited state lifetimes are promising for optical power limiting materials. The introduction of large π-conjugated substituents can switch the triplet excited state to a long-lived 3π,π* state. Herein, we report four Pt(ii) diimine complexes with high π-conjugation via inserting an aryl group on the diimine ligand. Their photophysical properties were investigated using spectroscopic techniques. All the complexes exhibit strong ground absorption bands in their UV-Vis absorption spectra (maximum peaks ranging from 370 to 530 nm) and long-lived emission and triplet excited states. The insertion of π-conjugated substituents induces a pronounced red-shift in the ground state absorption and longer emission lifetime. Broadband transient absorption spectra in the visible-NIR region and Z-scan properties under 532 nm were carried out on the Pt(ii) diimine complexes, resulting in a remarkably strong reverse saturable absorption at 532 nm for nanosecond laser pulses. Otherwise, the high π-conjugation in the bipyridyl ligand increases the reverse saturable absorption. Therefore, these Pt(ii) diimine complexes with high π-conjugation are excellent candidates for devices that require strong reverse saturable absorption.

Estimating short-term mortality and economic benefit attributable to PM10 exposure in China based on BenMAP.

With the rapidly booming economy, China has been suffering from serious particulate matter (PM) pollution in recent years. In order to improve the air quality, Chinese government issued a new China National Ambient Air Quality Standard (No. GB3095-2012) in 2012. In this study, PM10 exposure level was simulated based on the data of 912 newly constructed monitoring sites and Voronoi Neighborhood Averaging (VNA) interpolation method. It is widely accepted that PM10 can cause short-term health effects. We calculated the short-term health benefit due to decreasing PM10 concentration to the levels of China National Ambient Air Quality Standard based on Environmental Benefits Mapping and Analysis Program (BenMAP). Our results indicated that if the daily average concentration of PM10 reduced to the daily Grade II standard (150 µg/m3), the avoided deaths for all cause, cardiovascular disease, and respiratory disease would be 82,000 (95%CI: 49,000-120,000), 56,000 (95%CI: 34,000-78,000), and 16,000 (95%CI: 10,000-22,000) in 2014, respectively. The economic benefits of avoiding deaths due to all cause for rolling back the concentration of PM10 to the level of 50 µg/m3 were estimated to be 240 billion CNY and 16 billion CNY using willingness to pay (WTP) and human capital (HC) methods, respectively, which accounted for 0.38% (95%CI: 0.11-0.64%) and 0.03% (95%CI: 0.02-0.03%) of the total annual gross domestic product (GDP) of China in 2014.

Spatiotemporal modeling of PM2.5 concentrations at the national scale combining land use regression and Bayesian maximum entropy in China.

Concentrations of particulate matter with aerodynamic diameter <2.5 µm (PM2.5) are relatively high in China. Estimation of PM2.5 exposure is complex because PM2.5 exhibits complex spatiotemporal patterns. To improve the validity of exposure predictions, several methods have been developed and applied worldwide. A hybrid approach combining a land use regression (LUR) model and Bayesian Maximum Entropy (BME) interpolation of the LUR space-time residuals were developed to estimate the PM2.5 concentrations on a national scale in China. This hybrid model could potentially provide more valid predictions than a commonly-used LUR model. The LUR/BME model had good performance characteristics, with R2 = 0.82 and root mean square error (RMSE) of 4.6 µg/m3. Prediction errors of the LUR/BME model were reduced by incorporating soft data accounting for data uncertainty, with the R2 increasing by 6%. The performance of LUR/BME is better than OK/BME. The LUR/BME model is the most accurate fine spatial scale PM2.5 model developed to date for China.

Cerebral Microbleeds Do Not Predict Hemorrhagic Transformation in Acute Ischemic Stroke Patients with Atrial Fibrillation and/or Rheumatic Heart Disease.

BACKGROUND AND PURPOSE: Cerebral microbleeds (CMBs) are known to be potential risk factors for intracerebral hemorrhage (ICH), but there is controversy on the relationship between CMBs and hemorrhagic transformation (HT) after ischemic stroke. Besides, the question regarding whether the relationship between CMBs and HT can be affected by antithrombotic drugs in acute stage of ischemic stroke has not yet reached a consensus. METHODS: 174 acute ischemic stroke patients with atrial fibrillation (AF) and/or rheumatic heart disease (RHD) were prospectively and consecutively enrolled in the study, of which 160 patients (mean 68.09 ±12.59 years) were finally included in the final analysis (West China Hospital, Sichuan University, n=125; People's Hospital of Deyang City, n=35).We assessed the presence, location and number of CMBs by using susceptibility-weighted imaging (SWI) within 7 days after admission, and the incidence of hemorrhagic transformation was evaluated by magnetic resonance imaging(MRI) during hospitalization. The univariate and multivariate analyses were used to analyze the relationship between CMBs and HT. RESULTS: CMBs were detected in 90 patients (56.3%). HT was found in 62 (38.8%) patients, among which 43 were hemorrhagic infarction (HI) and 19 were parenchymal haemorrhage (PH). The presence of CMBs was not significantly different among different HT subtypes (no HT, HI and PH; 59.2%, 51.2%, versus 52.6%, P=0.64). There was no relationship between the number/location of CMBs and hemorrhagic transformation subtypes (P=0.38). In the 2 subgroups of patients treated with anticoagulants and antiplatelets after admission, the incidence of HT was not significantly different between patients with and without CMBs (anticoagulants, 13.3% versus 18.2%, P=0.71; antiplatelets, 29.2% versus 40.3%, P= 0.21). CONCLUSION: The present study suggests that CMBs do not predict the presence of hemorrhagic transformation in acute ischemic stroke patients with AF and/or RHD. The results were not affected by anticoagulant or antiplatelet agents used in acute stage of ischemic stroke.

A new species of the genus Teloganopsis with setaceous mouthparts and forelegs from southern China (Ephemeroptera, Ephemerellidae).

The nymph and reared male and female of a new ephemerellid species, which was collected from southern China and named Teloganopsis setosa Zhou, sp. n., are described. The nymph is unique because of its long and dense setae on labrum, mandibles, maxillae, labium, and forelegs as well as the elongated segments II of labial palpi and expanded paraglossae. The male can be differentiated from close relatives by its larger penis lobes with dorsolateral projections, and the more pigmented tergum IV and caudal filaments. The nymph described in this paper represents a new adaptive and ecological type in the family Ephemerellidae.

High-sensitivity cardiac troponin T levels and risk of cerebral microbleeds in acute ischemic stroke patients with atrial fibrillation and/or rheumatic heart disease.

BACKGROUND AND OBJECTIVE: Elevated high-sensitivity cardiac troponin T (hs-cTnT) levels are associated with coronary disease and small-vessel ischemic stroke through their associations with atherosclerosis. Considering the relationship between atherosclerosis and cerebral microbleeds (CMBs), the purpose of this study was to examine associations between serum hs-cTnT levels and risk of CMBs in acute ischemic stroke patients. METHODS: This prospective study involved consecutively recruited acute ischemic stroke patients with atrial fibrillation and/or rheumatic heart disease treated at a large tertiary care hospital in southwestern China. Clinico-demographic data were collected and analyzed by logistic regression to identify the relationship between serum hs-cTnT levels and CMB occurrence and location. RESULTS: In the final analysis, of 66 patients (27 males; mean age, 68.7years), 39 (59.1%) had CMBs. Hs-cTnT levels were not associated with risk of strictly lobar CMBs. However, after adjusting age, sex, current alcohol consumption, total cholesterol, hypertension, diabetes mellitus, prior antithrombotic therapy and NIHSS on admission, patients in the higher tertile were more likely to have CMBs and deep or infratentorial CMBs (P<0.05) compared with the lower hs-cTnT tertile. CONCLUSION: Hs-cTnT may be an independent predictor for the occurrence of CMBs, particularly of deep or infratentorial CMBs. This finding justifies further research into how hs-cTnT levels may contribute to CMBs and potentially other subclinical small-vessel diseases.

A cohort study of relationship between serum calcium levels and cerebral microbleeds (CMBs) in ischemic stroke patients with AF and/or RHD.

Calcium is an essential element for life and has cerebroprotective property in stroke patients. Low serum calcium levels were found to be related to large hematoma volumes in intracerebral hemorrhagic patients and hemorrhagic transformation in ischemic stroke patients after thrombolysis. However, their impact on hemorrhage-prone small vessel disease represented by cerebral microbleeds (CMBs) is uncertain. We aim to investigate whether low serum calcium levels are associated with presence and location of CMBs.Ischemic stroke patients with atrial fibrillation (AF) and/or rheumatic heart disease admitted to our hospital were consecutively and prospectively enrolled. Demographic and clinical information were collected and analyzed according to the occurrence and location of CMBs, and levels of serum calcium. We used logistic regression analysis to estimate the multivariable adjusted relationship between serum calcium levels and the presence or location of CMBs.Among the 67 patients (28 males; mean age, 67.3 years) in the final analysis, 39 (58.2%) were found to have CMBs. After adjustment for age, sex, smoking habits, drinking habits, and renal impairment, the presence of CMBs and deep CMBs was, respectively, 4.96- and 4.83-fold higher in patients with lower serum calcium levels (≤2.15 mmol/L) than in patients with higher serum calcium levels.Lower serum calcium levels (≤2.15 mmol/L) are independently associated with the presence of CMBs and deep CMBs in ischemic stroke patients with AF and/or rheumatic heart disease, which should be verified and extended in large cohorts, with other types of stroke patients and the general population.

Altered default mode and affective network connectivity in stroke patients with and without dysphagia.

OBJECTIVE: Neuroimaging studies in stroke patients provide substantial evidence for the involvement of widespread cortical and subcortical regions in the control of swallowing. Although the affective network and the default mode network are functionally related to "autonomic" and "volitional" swallowing, little is known about their functional changes in dysphagic stroke patients. METHODS: Unbiased seeds functional connectivity analysis was used to study the connectivity patterns of these resting-state networks. Resting-state functional magnetic resonance imaging was performed in stroke patients with (n = 12) and without dysphagia (n = 12). RESULTS: Compared with healthy controls, stroke patients with and without dysphagia had decreased functional connectivity in the default mode network and the affective network. Moreover, stroke patients with dysphagia also had decreased functional connectivity in both the default mode network and the affective network relative to patients without dysphagia. CONCLUSION: The difference in the extent of impairment in the default mode network and affective network of stroke patients with and without dysphagia may lead to improved understanding of the neuropathophysiological mechanism and rehabilitation of dysphagia.

Altered resting-state functional and white matter tract connectivity in stroke patients with dysphagia.

BACKGROUND: Swallowing dysfunction is intractable after acute stroke. Our understanding of the alterations in neural networks of patients with neurogenic dysphagia is still developing. OBJECTIVE: The aim was to investigate cerebral cortical functional connectivity and subcortical structural connectivity related to swallowing in unilateral hemispheric stroke patients with dysphagia. METHODS: We combined a resting-state functional connectivity with a white matter tract connectivity approach, recording 12 hemispheric stroke patients with dysphagia, 12 hemispheric stroke patients without dysphagia, and 12 healthy controls. Comparisons of the patterns in swallowing-related functional connectivity maps between patient groups and control subjects included (a) seed-based functional connectivity maps calculated from the primary motor cortex (M1) and the supplementary motor area (SMA) to the entire brain, (b) a swallowing-related functional connectivity network calculated among 20 specific regions of interest (ROIs), and (c) structural connectivity described by the mean fractional anisotropy of fibers bound through the SMA and M1. RESULTS: Stroke patients with dysphagia exhibited dysfunctional connectivity mainly in the sensorimotor-insula-putamen circuits based on seed-based analysis of the left and right M1 and SMA and decreased connectivity in the bilateral swallowing-related ROIs functional connectivity network. Additionally, white matter tract connectivity analysis revealed that the mean fractional anisotropy of the white matter tract was significantly reduced, especially in the left-to-right SMA and in the corticospinal tract. CONCLUSIONS: Our results indicate that dysphagia secondary to stroke is associated with disruptive functional and structural integrity in the large-scale brain networks involved in motor control, thus providing new insights into the neural remodeling associated with this disorder.