Azide Ionic Liquids for Safe, Green, and Highly-Efficient Azidation Reactions to Produce Azide Polymers.

Azide compounds are widely used and especially, polymers bearing pendant azide groups are highly desired in numerous fields. However, harsh reaction conditions are always mandatory to achieve full azidation, causing severe side reactions and degradation of the polymers. Herein, we report the design and preparation of two azide ionic liquids (AILs) with azide anion and triethylene glycol (E3 )-containing cation, [P444E3 ][N3 ] and [MIME3 ][N3 ]. Compared with the traditional sodium azide (NaN3 ) approach, both AILs showed much higher reaction rates and functional-group tolerance. More importantly, they could act as both reagents and solvents for the quantitative azidation of various polymeric precursors under mild conditions. Theoretical simulations suggested that the outstanding performance of AILs originated from the existence of ion pairs during the reaction, and the E3 moieties played a crucial role. Lastly, after the reaction, the AILs could be easily regenerated, presenting a safer, greener, and highly efficient synthesis route for azide polymers.

Synthesis and Properties of Biodegradable Hydrogel Based on Polysaccharide Wound Dressing.

The metabolic disorder of the wound microenvironment can lead to a series of serious symptoms, especially chronic wounds, which result in significant pain in patients. At present, there is no effective and widely used wound dressing. Therefore, it is important to develop new multifunctional wound dressings. Hydrogel is an ideal wound dressing for medical nursing because of its abilities to absorb exudate and maintain wound wetting, its excellent biocompatibility, and its ability to provide a moist environment for wound repair. Because of these features, hydrogel overcomes the shortcomings of traditional dressings. Therefore, hydrogel has high medical value and is widely studied. In this study, a biodegradable hydrogel based on polysaccharide was synthesized and used as a wound dressing. The swelling degree and degradability of hydrogel were characterized as the characteristics of the wound dressing. The results showed that the prepared hydrogel was degraded with trypsin and in the soil environment. Furthermore, the wound dressing can effectively inhibit the bacterial environment, promote the deposition of the collagen structure of the wound tissue, and accelerate the healing of the wound. The proposed hydrogel has value in practical medical nursing application.

Association between the triglyceride-glucose index and arterial stiffness: A meta-analysis.

BACKGROUND: Studies have shown a strong association between the triglyceride-glucose (TyG) index, a simple marker of insulin resistance, and various metabolic diseases. We performed a systematic review of the interaction between the TyG index and arterial stiffness. METHODS: Relevant observational studies assessing the association between the TyG index and arterial stiffness were thoroughly searched in PubMed, Embase, and Scopus, and a manual search of the preprint server was conducted. A random-effects model was utilized to analyze the data. The risk of bias for the included studies was assessed using the Newcastle-Ottawa Scale. A pooled effect size estimate with a random-effects model was used for the meta-analysis. RESULTS: Thirteen observational studies comprising 48,332 subjects were included. Of these, 2 were prospective cohort studies, and the remaining 11 were cross-sectional studies. According to the results of the analysis, the risk of developing high arterial stiffness was 1.85 times greater for those in the highest TyG index subgroup versus the lowest group (risk ratio [RR]: 1.85, 95% confidence interval: 1.54-2.33, I2 = 70%, P < .001). Consistent results were observed when the index was analyzed as a continuous variable (RR: 1.46, 95% confidence interval: 1.32-1.61, I2 = 77%, P < .001). A sensitivity analysis excluding each of the studies one by one yielded similar results (RRs for categorical variables: 1.67-1.94, P all <.001; RRs for continuous variables: 1.37-1.48, P all <.001). A subgroup analysis showed that different characteristics of the study subjects, such as type of study design, age, population, disease status, (including hypertension and diabetes), and pulse wave velocity measurement methods had no substantial effect on the results (P for subgroup analysis, all >0.05). CONCLUSIONS: A relatively high TyG index might be linked to an increased incidence of arterial stiffness.

Preparation and Performance Analysis of Bacterial Cellulose-Based Composite Hydrogel Based on Scanning Electron Microscope.

In order to better prepare and analyze bacterial cellulose-based composite hydrogels, an experimental method based on scanning electron microscopy was proposed. The specific content of the method is to observe the hydrogel through scanning electron microscope, to observe the space between molecules through experiments, and to improve the effect of bacterial cellulose preparation of hydrogel. The experimental results show that the gel preparation effect is best when PEG concentration is not more than observed by scanning electron microscope. It is better to prepare bacterial cellulose complex hydrogel by scanning electron microscopy.

Understanding wildlife crime in China: Socio-demographic profiling and motivation of offenders.

Wildlife crime presents a growing threat to the integrity of ecological communities. While campaigns have raised consumer awareness, little is known about the socio-demographic profile of wildlife offenders, or how to intervene. Using data from China Judgements Online (2014-2018), we documented 4,735 cases, involving 7,244 offenders who smuggled, hunted, transported, sold and/or purchased protected species in contravention of China's Criminal Law. Offenders were predominantly men (93.0% of 7,143 offenders), aged 30-44 (43.9% of 4,699), agricultural workers (48.4% of 3,960), with less schooling (78.6% of 4,699 < senior secondary school). Socio-economic profiles related to crime seriousness, the type of illegal activity, motivation and taxon involved. These generalizations reveal scope to tailor specific intervention and mitigation approaches to offender profiles, through public information campaigns, proactive incentives opposed by punitive disincentives, and provision of alternative incomes.

Prosecution records reveal pangolin trading networks in China, 2014-2019.

In a precautionary response to the current coronavirus (COVID-19) pandemic, China's Ministries permanently banned eating and trading in terrestrial wild (non-livestock) animals on 24 February 2020, and extensively updated the list of Fauna under Special State Protection (LFSSP) in 2020 and 2021, in which pangolins (Manidae spp.) were upgraded to the highest protection level. Examining 509 pangolin prosecution records from China Judgements online prior to these changes (01/01/14-31/12/19), we identified that Guangdong, Guangxi and Yunnan Provinces were hotspots for trade in whole pangolins and their scales. Interrupting trade in these three principal southern provinces would substantially fragment the pangolin trade network and reduce supply of imports from other south-east Asian countries. In the context of the revised legislation and strategies intended to prevent wildlife trade, we conclude that targeting interventions at key trade nodes could significantly reduce illegal trade in pangolins, and that this approach could also be effective with other taxa.

Factors regulating trophic status in a large subtropical reservoir, China.

We evaluated a 4-year data set (July 2003 to June 2007) to assess the trophic state and its limiting factors of Three-Gorges Reservoir (TGR), China, a large subtropical reservoir. Based on Carlson-type trophic state index (TSI)(CHL), the trophic state of the system was oligotrophic (TSI(S) < 40) in most months after the reservoir became operational, although both TSI(TP) and TSI(TN) were higher than the critical value of eutrophic state (TSI(S) > 50). Using Carlson's (1991) two-dimensional approach, deviations of the TSI(S) indicated that factors other than phosphorus and nitrogen limited algal growth and that nonalgal particles affected light attenuation. These findings were further supported by the significant correlation among the values of TSI(CHL) - TSI(SD) and nonvolatile suspended solids and water residence time. The logarithmic model showed that an equivalent TSI(CHL) and TSI(SD) could be found at tau = 54 days in the TGR (Fig. 7). Accordingly, nonalgal particulates dominated light attenuation and limited algal biomass of the reservoir when tau < 54 days.

Characteristics and variability of functional brain networks.

Functional brain networks were constructed from functional magnetic resonance imaging (fMRI) data originating from 96 healthy adults. These networks possessed a total of 360 nodes, derived from the latest multi-modal brain parcellation method. A novel group network (overlay network) analysis model is proposed to study common attributes as well as differences found in the human brain by analysis of the functional brain network. Currently, the mean network is generally used to represent the group network. But mean networks have a modularity problem making them distinct from real networks. The overlay network is constructed by calculating the connections between the whole brain network regions, and then filtering the connections by limiting the threshold value. We find that the overlay network is closer to the real network condition of the group in terms of network characteristics related to modularity. Multiple network features are applied to investigate the discrepancies between the new group network and the mean network. Individual divergences between brain regions of everyone are also explored. Results show that the brain network of different people has a high consistency in the global measures, while there exist great differences for local measures in brain regions. Some brain regions show variability over other brain regions on most measures. In addition, we explored the impact of different thresholds on the overlay network and find that different thresholds have a greater impact on the clustering coefficient, maximized modularity, strength, and global efficiency.

Alzheimer's disease, mild cognitive impairment, and normal aging distinguished by multi-modal parcellation and machine learning.

A 360-area surface-based cortical parcellation is extended to study mild cognitive impairment (MCI) and Alzheimer's disease (AD) from healthy control (HC) using the joint human connectome project multi-modal parcellation (JHCPMMP) proposed by us. We propose a novel classification method named as JMMP-LRR to accurately identify different stages toward AD by integrating the JHCPMMP with the logistic regression-recursive feature elimination (LR-RFE). In three-group classification, the average accuracy is 89.0% for HC, MCI, and AD compared to previous studies using other cortical separation with the best classification accuracy of 81.5%. By counting the number of brain regions whose feature is in the feature subset selected with JMMP-LRR, we find that five brain areas often appear in the selected features. The five core brain areas are Fusiform Face Complex (L-FFC), Area 10d (L-10d), Orbital Frontal Complex (R-OFC), Perirhinal Ectorhinal (L-PeEc) and Area TG dorsal (L-TGd, R-TGd). The features corresponding to the five core brain areas are used to form a new feature subset for three classifications with the average accuracy of 80.0%. Results demonstrate the importance of the five core brain regions in identifying different stages toward AD. Experiment results show that the proposed method has better accuracy for the classification of HC, MCI, AD, and it also proves that the division of brain regions using JHCPMMP is more scientific and effective than other methods.

[Fluorescence Characteristics and Influencing Factors of Dissolved Organic Matter (DOM) in Water and Sediment of Urban Watershed: A Case Study of Xiaojia River in Ningbo City].

Rapid urbanization has a significant impact on dissolved organic matter (DOM) in water and sediment; thus, it is important to explore the distribution characteristics and influencing factors of DOM in watersheds. Xiaojia River is a typical urban area in Beilun District of Ningbo City, Yangtze River Delta. The spectral characteristics of DOM in the water and sediment in this river were studied to examine their sources and characteristics. The DOM was analyzed by three-dimensional fluorescence spectroscopy (EEM) coupled with the parallel factor analysis (PARAFAC) model. The following results were noted. ① Four fluorescence DOM components were derived by EEM-PARAFAC:C1 represents terrestrial humus with a high molecular weight; C2 represents terrestrial humus with a low molecular weight, which was produced by biodegradation; C3 represents protein-like substances that were sensitive in a microenvironment; and C4 is terrestrial humus. ② Both new-born endogenous and terrestrial sources have large impacts on DOM components. The humification degree was very weak with a low concentration of humus. The DOM in the sediments was derived mainly from terrestrial or soil sources with small endogenous contribution with high humification. The concentration of humus in the sediments was significantly higher than that in water. ③ Redundancy analysis (RDA) showed that farmland and urban land use were the dominant environmental factors and had relatively high correlation with the water indicators. Construction land, farmland, and wetland land use positively correlated with the sediment components. Among them, urban land use had the greatest influence on the concentration parameter Fn(355) of humus-like substance C4 and the humus-like substance in sediments.

A novel joint HCPMMP method for automatically classifying Alzheimer's and different stage MCI patients.

A 360-area surface-based cortical parcellation was recently generated using multimodal data in a group average of 210 healthy young adults from the Human Connectome Project (HCP). In order to automatically and accurately identify mild cognitive impairment (MCI) at its two levels (early MCI and late MCI), Alzheimer's disease (AD) and healthy control (HC), a novel joint HCP MMP method was first proposed to delineate the cortical architecture and function connectivity in a group of non healthy adults. The proposed method was applied to register a dataset of 96 resting-state functional connectomes from the Alzheimer's Disease Neuroimaging Initiative (ADNI) to Connectivity Informatics Technology Initiative (CIFTI) space and parcellated brain into human connectome project multi-modal parcellation (HCPMMP) with 360 areas. Various network features in each node of the connectivity network were considered as the candidate features for classification.The fine-grained multi-modal based on HCP-MMP combined with machine learning in identification for EMCI, LMCI, AD and HC. Applying various network features, including strength, betweenness centrality, clustering coefficient, local efficiency, eigenvector centrality, etc, we trained and tested several machine learning models. Thousands of features were processed by filter and wrapper feature selection procedures, and finally there were thirty features to be selected to achieve classification accuracies of 93.8% for EMCI vs. HC, 95.8% for LMCI vs. HC, 95.8% for AD vs. HC, and 91.7% for LMCI vs. AD, respectively by using support vector machine (SVM) algorithm. Most of the selected features locate in the region of temporal or cingulate cortex. Compared with previous studies, our results demonstrate the superiority of the proposed method over existing techniques.

[Characteristics of Dissolved Organic Matter (DOM) and Relationship with Dissolved Heavy Metals in a Peri-urban and an Urban River].

Dissolved organic matter (DOM) is ubiquitous in the aquatic environment, playing an important role in the fate of heavy metals in aquatic systems. In this study, we characterized the DOM and heavy metals and their distribution in a peri-urban river and an urban river in Ningbo city. In addition, the relationship between DOM and dissolved heavy metals was also determined. Results showed that higher DOC, CDOM, and FDOM concentrations were found in the river with the higher urbanization level. Four fluorescence peaks were identified in the excitation-emission matrix (EEM) of DOM, including fulvic acid-like fluorescence peaks A and C and protein-like fluorescence peaks B and T. The higher fluorescence intensities of peak B and T were found in the urban river, and similar trends were also found for the degree of humification and aromaticity of DOM. Similarly, concentrations of heavy metals, such as As, Cu, and Mn, were significantly higher in the urban river. Moreover, DOM had significant positive correlations with Cu, Cr, Mn, As, Zn, and Pb in the urban river, while DOM only exhibited significant positive correlations with Mn, Pb, and Cu in the peri-urban river. In conclusion, urbanization level influenced the characteristics and concentrations of CDOM in rivers which were closely related to the distribution of heavy metals.

Temporal Asynchrony of Trophic Status Between Mainstream and Tributary Bay Within a Giant Dendritic Reservoir: The Role of Local-Scale Regulators.

Limnologists have regarded temporal coherence (synchrony) as a powerful tool for identifying the relative importance of local-scale regulators and regional climatic drivers on lake ecosystems. Limnological studies on Asian reservoirs have emphasized that climate and hydrology under the influences of monsoon are dominant factors regulating seasonal patterns of lake trophic status; yet, little is known of synchrony or asynchrony of trophic status in the single reservoir ecosystem. Based on monthly monitoring data of chlorophyll a, transparency, nutrients, and nonvolatile suspended solids (NVSS) during 1-year period, the present study evaluated temporal coherence to test whether local-scale regulators disturb the seasonal dynamics of trophic state indices (TSI) in a giant dendritic reservoir, China (Three Gorges Reservoir, TGR). Reservoir-wide coherences for TSI(CHL), TSI(SD), and TSI(TP) showed dramatic variations over spatial scale, indicating temporal asynchrony of trophic status. Following the concept of TSI differences, algal productivity in the mainstream of TGR and Xiangxi Bay except the upstream of the bay were always limited by nonalgal turbidity (TSI(CHL)-TSI(SD) <0) rather than nitrogen and phosphorus (TSI(CHL)-TSI(TN) <0 and TSI(CHL)-TSI(TP) <0). The coherence analysis for TSI differences showed that local processes of Xiangxi Bay were the main responsible for local asynchrony of nonalgal turbidity limitation levels. Regression analysis further proved that local temporal asynchrony for TSI(SD) and nonalgal turbidity limitation levels were regulated by local dynamics of NVSS, rather than geographical distance. The implications of the present study are to emphasize that the results of trophic status obtained from a single environment (reservoir mainstream) cannot be extrapolated to other environments (tributary bay) in a way that would allow its use as a sentinel site.

[Spatiotemporal distribution of total nitrogen and total phosphorus in sediments of Xiangxi Bay, Three Gorges Reservoir].

The spatiotemporal distribution of total nitrogen (TN) and total phosphorus (TP) in sediments of Xiangxi Bay, Three Gorges Reservoir was investigated from October 2004 to July 2006, with related affecting factors analyzed. The TN and TP concentrations in the sediments were higher in the middle stretch but lower in the two edges of the Bay. The maximum value of TN concentration (1.08 mg x g(-1)) appeared in the middle part of the Bay, and the minimum (0.89 mg x g(-1)) occurred at the adjacent areas to the river mouth; while the maximum value of TP concentration (1.07 mg x g(-1)) appeared in the middle, and the minimum (0.80 mg x g(-1)) was in the edges of the Bay. The TN concentration decreased in the sequence of autumn-winter-spring, but increased from spring to summer dramatically; while the seasonal variation of TP concentration was not very significant, with the maximum occurred in spring. Significant inter-annual variations were observed in the TN and TP concentrations. The spatial distributions of TN and TP concentrations were mainly affected by the sedimentation of suspended matter. In the regions where sedimentation rate was high, the TN and TP concentrations were also very high. The seasonal fluctuation of TN concentration was mainly affected by river discharge, while that of TP concentration was mainly affected by point source pollution.

[Macrobenthos in Jinping reach of Yalongjiang River and its main tributaries].

In this paper, an investigation was made on the macrobenthos at 25 sites in the Jinping reach of Yalongjiang River and its main tributaries in May and November 2004, aimed to study the relationships between macrobenthos distribution and environmental factors. The results showed that the dominant species of macrobenthos was Baetis sp. (Baetidae, Ephemeroptera), with a relative abundance being 14.9% and 27.0% in May and November, respectively. Based on the species composition and their relative abundance, and by using two-way indictor species analysis (TWINSPAN) and detrended correspondence analysis (DCA), the macrobenthods was divided into four groups, according to the habitat types of the sites. Canonical correspondence analysis (CCA) on the relationships between macrobenthods community structure and environmental factors indicated that in May, elevation and water hardness and NH4+ -N content were the main environmental factors affecting macrobenthods distribution, while in November, elevation, water hardness, NH4+ -N and SiO2 contents were the main ones.