Search

Bone metastases are common in malignant tumors and the effect of conventional treatment is limited. How to effectively inhibit tumor bone metastasis and deliver the drug to the bone has become an urgent issue to be solved. While bone targeting drug delivery systems have obvious advantages in the treatment of bone tumors. The research on bone-targeted anti-tumor therapy has made significant progress in recent years. We introduced the related tumor pathways of bone metastases. The tumor microenvironment plays an important role in metastatic bone tumors. We introduce a drug-loading systems based on different environment-responsive nanocomposites for anti-tumor and anti-metastatic research. According to the process of bone metastases and the structure of bone tissue, we summarized the information on bone-targeting molecules. Bisphosphate has become the first choice of bone-targeted drug delivery carrier because of its affinity with hydroxyapatite in bone. Therefore, we sought to summarize the bone-targeting molecule of bisphosphate to identify the modification effect on bone-targeting. And this paper discusses the relationship between bisphosphate bone targeting molecular structure and drug delivery carriers, to provide some new ideas for the research and development of bone-targeting drug delivery carriers. Targeted therapy will make a more outstanding contribution to the treatment of tumors.

The removal of or decrease in pesticide residues in soil has attracted considerable attention, due to the serious pollution of pesticides in soil. The purpose of the study was to explore the adsorption behavior of biochar on pesticides and the impact on the degradation of pesticide residues in soil, providing a basis for the remediation of soil by biochar. Biochars were prepared via pyrolysis of rice straw at a high temperature (300 °C, 400 °C, 500 °C, 600 °C). The individual and competitive adsorption of three triazine herbicides, prometryn, atrazine, and simazine, on biochar was investigated, and the degradation of the herbicide residues in biochar-added soil was determined. The selected herbicides presented similar adsorption characteristics to rice straw biochar, and the amount of herbicides adsorbed increased with higher preparation temperature and the amount of biochar. The rice straw biochar adsorbed the studied herbicides simultaneously, and the adsorption amount decreased as follows: simazine > atrazine > prometryn. The competition adsorption of the selected herbicides on the biochar presented a lower adsorption affinity than that when they are adsorbed individually. The adsorption isotherm was best fitted by the Freundlich model. The half-lives of prometryn, atrazine, and simazine were 9.8~12.6 d, 5.2~8.1 d, and 3.7~5.6 d, respectively. Biochar addition increased the degradation of the evaluated herbicides in soil. The rice straw biochar could be the potential sorbents that can be implemented for the removal of pesticides.

Effective prediction of carbon prices matters a great deal for risk management in the carbon financial market. This article designs a blended approach incorporating secondary decomposition and nonlinear error-correction technology to predict the regional carbon price in China. Firstly, the variational mode decomposition (VMD) method is used to decompose the carbon price, and then, the time-varying filter-based empirical mode decomposition (TVFEMD) is introduced to decompose the residual term generated by VMD, and the multiple kernel-based extreme learning machine (MKELM) optimized by the sparrow search algorithm (SSA) is innovatively built to forecast the carbon subsequences. Finally, in order to mine the hidden information contained in the forecasted error, the nonlinear error-correction method based on the SSA-MKELM model is introduced to correct the initial prediction of carbon price. The empirical results show that the proposed model improves the prediction accuracy of carbon prices, with RMSE, MAE, MAPE, and DS up to 0.1363, 0.1160, 0.0015, and 0.9231 in Guangdong, respectively. In the case of the Hubei market, the model also performs best. This research innovatively expands the prediction theory and method of China’s regional carbon price.

The exploding popularity of social networks, provides a new opportunity to study disasters and public emotion. Among the social networks, Weibo is one of the largest microblogging services in China. Taking Guangdong and Guangxi in the south of China as a case, Web Scraper was used to obtain Weibo texts related to floods in 2020. The spatial distribution of floods was analyzed using Kernel Density Estimation. Public emotion was analyzed using Natural Language Processing (NLP) tools. The association between floods and public emotion was explored through correlation analysis methods. The results indicated that: (1) Weibo texts could be utilized as an effective data to identify urban waterlogging risk in Guangdong and Guangxi. (2) More floods occurred in the southeast than in the central and northwest, and more in the south than in the north in Guangdong and Guangxi. The coastal cities and provincial capitals were severely affected. (3) The public emotion was mainly negative and varied significantly over time, generally showing stronger negative emotion during periods of heavy precipitation. (4) There was a strong correlation between public emotion and floods in spatial-temporal variation. The degree of negative public emotion was significantly influenced by the number of waterlogging points. The presented results serve as the pre-liminary data for future planning and designing of emergency management.

Начально-краевые задачи для матричной системы Лакшманана-Порсезиана-Дэниеля изучаются с использованием унифицированного преобразования Фокаса. Проведен спектральный анализ ($4\times4$)-матричной пары Лакса типа Абловица-Каупа-Ньюэла-Сигура. Показано, что решения исследуемой матричной системы можно восстановить из ($4\times4$)-матричной задачи Римана-Гильберта. Кроме того, доказано, что спектральные функции не являются независимыми, а связаны так называемым глобальным соотношением.

In this paper, we investigate the fifth-order modified Korteweg-de Vries (fomKdV) equation on the half-line via the Fokas unified transformation approach. We show that the solution u(x,t) of the fomKdV equation can be represented by the solution of the matrix Riemann-Hilbert problem constructed on the plane of complex spectral parameter θ. The jump matrix L(x,t,θ) has an explicit representation depended on x, t and it can be represented exactly by the two pairs of spectral functions y(θ),z(θ) (obtained from the initial value u0(x)) and Y(θ),Z(θ) (obtained from the boundary conditions v0(t), vk(t), k=1,2,3,4). Furthermore, the two pairs spectral functions y(θ),z(θ) and Y(θ),Z(θ) are not independent of each other, but are related to the compatibility condition, the so-called global relation.

Purpose:This study examined safety, pharmacokinetics, and efficacy of veliparib, a PARP inhibitor, combined with carboplatin and etoposide in patients with extensive-stage (ED) small cell lung cancer (SCLC) and other solid tumors.Patients and Methods:The 3 + 3 design was used for dose escalation of oral veliparib in combination with carboplatin (AUC 5 on day 1) and etoposide (100 mg/m2 on days 1–3) in 21-day cycles. Veliparib dose was explored from 80 to 240 mg b.i.d. on 7-day, 14-day, or continuous schedules. Patients without disease progression continued on maintenance monotherapy (veliparib 400 mg b.i.d.) until disease progression or unacceptable toxicity.Results:Thirty-nine patients were enrolled to determine the recommended phase II dose of 240 mg veliparib for 14 days combined with carboplatin and etoposide based on long-term tolerability. Dose-limiting toxicity occurred in 1 patient (grade 2 toxic motor polyneuropathy) at veliparib 240 mg b.i.d. for 7 days. Most common adverse events related to veliparib were nausea (39%), fatigue (39%), and hematologic toxicities. Continuous dosing of veliparib 240 mg b.i.d. with carboplatin and etoposide resulted in excessive chemotherapy dose delays due to hematologic toxicity (grade 3/4 neutropenia/thrombocytopenia). Etoposide pharmacokinetics was not affected by veliparib. Confirmed responses occurred in 17 of 39 (44%) and 16 of 25 (64%) of all enrolled and ED SCLC patients, respectively. At the RP2D, confirmed responses occurred in 6 of 13 (46%) and 5 of 6 (83%) of all enrolled and ED SCLC patients, respectively.Conclusions:Veliparib (240 mg b.i.d. 14 days) plus carboplatin/etoposide can be safely combined. Phase II of this study is ongoing in first-line patients with ED SCLC.

Table S1. Tolerability of veliparib, carboplatin, and etoposide over entire combination cycles treatment period Table S2. Mean {plus minus} SD (% CV) pharmacokinetic parameters of veliparib following oral administration of veliparib in combination with carboplatin and etoposide on Cycle 1 Day 1 Figure S1. Mean (+SD) dose normalized etoposide plasma concentration-time profile with and without veliparib co-administration Table S3. Pharmacokinetic parameters of etoposide {plus minus} veliparib Table S4. Objective response rate in biomarker cohort by tumor type and veliparib dose level Figure S2. Tumor response and time on study for all dosed patients (n=39) Figure S3. Progression-free survival by disease type Figure S4. Confirmed objective response by gene type in small cell lung cancer samples (n=17)

Purpose:Bromodomain and extraterminal (BET) proteins play important roles in transcriptional regulation relevant to cancer pathogenesis, and therapeutic targeting/inhibition of BET causes apoptosis of cancer cells in vitro. In this first-in-human study of the pan-BET inhibitor mivebresib (ABBV-075), the safety profile, MTD, and recommended phase II dose (RP2D) were determined in patients with advanced solid tumors.Patients and Methods:A 3 + 3 dose escalation for different mivebresib dosing schedules [daily, Monday/Wednesday/Friday (M-W-F), 4 days on/3 off (4/7)] was followed by dose expansion in patients with prostate cancer. Endpoints were safety, tolerability, pharmacokinetics, and preliminary antitumor activity.Results:Seventy-two patients with solid tumors (14% uveal melanoma; 11% colorectal; 11% breast; 8% pancreatic; 7% head/neck; 49% others) were treated with mivebresib during dose escalation, and 12 additional patients with prostate cancer in expansion cohort. Most common treatment-emergent adverse events (TEAE) related to mivebresib were dysgeusia (49%), thrombocytopenia (48%), fatigue (26%), and nausea (25%). Most common grade 3/4 TEAEs related to mivebresib were thrombocytopenia (35%) and anemia (6%). Dose-limiting toxicities included thrombocytopenia (2 mg daily; 4.5 mg M-W-F), gastrointestinal bleed (2 mg daily), hypertension (2–3 mg 4/7), fatigue, decreased appetite, and aspartate aminotransferase elevation (4 mg M-W-F). Of 61 evaluable patients from dose escalation, 26 (43%) had stable disease and 35 (57%) had progressive disease. Median progression-free survival was 1.8 months (95% confidence interval, 1.8–1.9).Conclusions:On the basis of safety and tolerability, mivebresib RP2D is 1.5 mg for the daily schedule, 2.5 mg for 4/7, and 3 mg for M-W-F. Mivebresib has a tolerable safety profile, and stable disease was observed in some patients with malignant solid tumors.

Supplemental Methods, Figures S1-S5, Tables S1-S7

Being at the forefront of China’s regional innovation and development, enterprises in the National Innovation Demonstration Zones must take the lead in completing high-quality transformation and upgrading. In this study, we use data from 1770 manufacturing companies from China’s 21 National Innovation Demonstration Zones. Based on the multi-factor influence model, we quantitatively study a series of factors that affect enterprise transformation and upgrading capability in terms of innovation-driven input, economically beneficial output, regional high-quality development, and the enterprise’s basic environment. The research results show a good trend in enterprise transformation and upgrading capability, and 45% of the enterprises have higher capabilities than the average of these zones. There are significant differences in these capabilities across the different National Innovation Demonstration Zones. Economically beneficial output has a relatively large impact on enterprise transformation and upgrading capability, while innovation-driven input, regional high-quality development, and the enterprise’s basic environment all have a relatively small impact. We suggest that the National Innovation Demonstration Zones and relevant departments should provide policy guarantees for enterprise transformation and upgrading in terms of regional systems, industrial chain layout, and soft environment optimization, so as to fully enable policy benefits from top-level design.

Organogels are excellent drug carrier for controlled release. Organogels based on amino acid derivatives has been widely used in the area of drug delivery. In this study, a series of the organogel system based on amino acid derivatives gelators was designed and prepared to investigate the structure-property correlation in organogels. To investigate the factors that influence the property of drug release, we varied the formulation in the organogels: gelator structure, gelator concentration, volume of antigelation solvent, and drug loading. Through the Box–Behnken tests, the optimum organogel formulation in vitro was obtained. The self-healing properties of the organogel have been utilised for injection of a model lipophilic risperidone in situ, and sustained release of the drug has been studied over about one week in vivo. In conclusion, the gelation ability of gelators could be adjusted by the gelator structure. Gel property is related with the whole composition of the formulation. As drug carrier, the drug release property of organogels is affected by multiple factors. Our investigation of the gel release property will play a theoretical guiding role in the application in the in situ drug delivery system.

Urban multimodal transportation effectively meets the diversified travel demand of residents. However, it also generates extensive development problems such as traffic congestion, exhaust emissions and low operational efficiency. Therefore, there is an urgent need in urban sustainable development to achieve the coordinated and stable development of various modes of transportation. In this study, we took 36 major cities in China as the research object; measured the comprehensive development level of urban multimodal transportation; used the coupling coordination degree model (CCDM) to research the coordinated development relationship among buses, rail transit, and taxis; and clarified the shortcomings of the coordinated development of multimodal transportation. The results show that the comprehensive development of urban multimodal transportation in China has shown a significant upward trend from 2016 to 2020, with an average annual growth rate of about 7.36%. There are significant differences in the development levels of multimodal transportation in different cities. In addition, the relationship among buses, rail transit, and taxis in the major cities in China presents a state of uncoordinated development. Therefore, the relevant departments of cities should optimize the allocation of transportation resources, in terms of infrastructure construction and operation, according to these development levels and coordination of multimodal transportation.

Для изучения начально-краевой задачи для комбинированного уравнения Шредингера-Герджикова-Иванова на полуоси применяется метод Фокаса. В предположении, что решение $u(x,t)$ этого уравнения существует, его можно представить как единственное решение матричной задачи Римана-Гильберта на плоскости комплексного спектрального параметра $\xi$. Матрицы скачков определяются спектральными функциями, которые не являются независимыми, а связаны глобально.

In this paper, by using Fokas method, we study the initial-boundary value problems (IBVPs) of the fourth-order dispersive nonlinear Schrödinger (FODNLS) equation on the half-line, which can simulate the nonlinear transmission and interaction of ultrashort pulses in the high-speed optical fiber transmission system, and can also describe the nonlinear spin excitation phenomenon of one-dimensional Heisenberg ferromagnetic chain with eight poles and dipole interaction. By discussing the eigenfunctions of Lax pair of FODNLS equation and analyzing symmetry of the scattering matrix, we get a matrix Riemann–Hilbert (RH) problem from for the IBVPs of FODNLS equation. Moreover, we get the potential function solution u(x, t) of the FODNLS equation by solving this matrix RH problem. In addition, we also obtain that some spectral functions satisfy an important global relation.

Most proteins given orally have low bioavailability and are easily eliminated by rapid metabolism in vivo. In order to immobilize the drug at the site of administration and delay its release, a natural, gentle release system was designed. In this study, a heteropolysaccharide (ZOP) was isolated from Zingiber officinale using an ultrasonic assisted extraction method. ZOP Ara = 1.97: 1.15: 94.33: 1.48: 1.07. The ZOP/Chitosan (CS) composite hydrogel was synthesized using epichlorohydrin (ECH) as a cross-linking agent. The structure, morphology, and water-holding capacity of the composite hydrogel were characterized. The data showed that the addition of ZOP improved the hardness and water-holding capacity of the material. A swelling ratio test showed that the prepared hydrogel was sensitive to pH and ionic strength. In addition, the degradation rate of the hydrogel in a phosphate-buffered saline (PBS) solution with a pH value of 1.2 was higher than that in PBS with pH value of 7.4. Similarly, the release kinetics of Bovine serum albumin (BSA) showed higher release in an acidic system by the hydrogel composed of ZOP/CS. The hydrogel prepared by this study provided a good microenvironment for protein delivery. In summary, this composite polysaccharide hydrogel is a promising protein-drug-delivery material.

Most proteins given orally have low bioavailability and are easily eliminated by rapid metabolism in vivo. In order to immobilize the drug at the site of administration and delay its release, a natural, gentle release system was designed. In this study, a heteropolysaccharide (ZOP) was isolated from

Downloads and citations of papers are regarded as significant metrics of the academic level of researchers and the influence of journals. Besides, exploring the association between them helps grease the wheels of the academic evaluation system. In this paper, we select 7552 articles published in The Lancet from January 2007 to October 2017 as the research sample and conduct Granger causal inference to investigate the relationship and directionality between downloads and citations. Furthermore, based on the download-citation patterns of articles, this study stratifies articles to explore the directionality between the downloads and citations of articles with different patterns. The results show that 75.86% of the articles have Granger causality between download and citation counts, suggesting that there is a significant causal relationship between downloads and citations. Specifically, the proportion of articles with bilateral Granger causality between download counts and citation counts is the highest, accounting for 35.51%; the proportion of articles whose download counts affect citation counts unilaterally accounts for 14.3%; and the proportion of articles whose citation counts affect download counts unilaterally accounts for 26.05%; 24.14% of the articles have no Granger causality between downloads and citations. Further, most Lancet articles are downloaded more at the early stage after publication, while the citations mainly appear after a period of time, making the slope trend of downloads and citations inconsistent throughout the citation life cycle. Meanwhile, the Granger causal relationship between downloads and citations is related to the slope of their curves. That is, the metric with a lower slope tends to be influenced by the metric with a higher slope.

Correlation has become a fundamental method for information science. However, correlations are limited in making concrete decisions. In this article, we detail how causal inference could be utilised in the field of information science. There are six main steps of implementing matching for causal inference, namely, selecting candidate control variables, determining control variables, calculating similarities among all samples, forming control group, examining the performance of control group and estimating causal effects. As an example, this article applies causal inference to investigate whether Nobel Physics award increases the after-award citations. The method is presented in a step-by-step manner so that researchers can reproduce our analysis in the future.

Polygonatum sibiricum polysaccharides (PSPs) have important biological functions, such as antioxidation, immunomodulatory, and hypolipidemic functions. Different extraction methods have effects on their structures and activities. In this study, six extraction methods, including hot water extraction (HWE), alkali extraction (AAE), ultrasound-assisted extraction (UAE), enzyme-assisted extraction (EAE), microwave-assisted extraction (MAE), and freeze–thaw-assisted extraction (FAE) were used to extract PSPs, and their structure–activity relationships were analyzed. The results showed that all six PSPs had similar functional group compositions, thermal stability, and glycosidic bond compositions. PSP-As (PSPs extracted by AAE) exhibited better rheological properties due to their higher molecular weight (Mw). PSP-Es (PSPs extracted by EAE) and PSP-Fs (PSPs extracted by FAE) had better lipid-lowering activity due to their lower Mw. PSP-Es and PSP-Ms (PSPs extracted by MAE), which do not contain uronic acid and have a moderate Mw, had better 1,1-diphenyl-2-picrylhydrazyl (DPPH)-radical-scavenging activity. On the contrary, PSP-Hs (PSPs extracted by HWE) and PSP-Fs, with the Mw of uronic acid, had the best OH-radical-scavenging activity. The high-Mw PSP-As had the best Fe2+-chelating ability. In addition, mannose (Man) may play an important role in the immunomodulatory activity. These results indicate that different extraction methods affect the structure and biological activity of polysaccharides to varying degrees, and these results are helpful for understanding the structure–activity relationship of PSPs.

Background: Tumor mutation burden (TMB) has been considered biomarker for using of immune checkpoint inhibitors(ICIs), but whole exome sequencing(WES) and cancer gene panel(CGP) based on next generation sequencing for TMB detection are costly. Here, we use transcriptome data of TCGA to construct a model for TMB prediction in gastrointestinal tumors.Methods: Transcriptome data, somatic mutation data and clinical data of four gastrointestinal tumors from TCGA, including esophageal cancer (ESCA), stomach adenocarcinoma (STAD), colon adenocarcinoma (COAD) and rectal adenocarcinoma (READ). Using R, we performed visual analysis of somatic mutation data, differentially expressed genes (DEGs) function enrichment analysis, gene set enrichment analysis (GSEA), and estimated the value of TMB in clinic. Finally, a deep neural network (DNN) model was constructed for TMB prediction.Results: Visualization of somatic mutation data summarized the classification of mutation, frequency of each mutation type, and top-mutated genes. GSEA showed the enrichment of CD4+/CD8+ T cells in the high TMB group and the activation of tumor suppressing pathways. Single-sample GSEA (ssGSEA) found that the high-TMB group had higher level of multiple immune cells infiltration. In addition, distribution of TMB was related to age, M stage, N stage, AJCC stage, and overall survival. After model optimization with the genetic algorithm, in the training set, validation set, and testing set, the Pearson relevance coefficient r between predicted values and actual values reaches 0.98, 0.82, and 0.92, respectively; the coefficient of determination R2 is 0.95, 0.82, and 0.7, respectively. Conclusion: TMB correlates with clinicopathological parameters in gastrointestinal carcinoma, and patients with high TMB have higher levels of immune infiltration. In addition, the DNN model based on 31 genes predicts TMB of gastrointestinal tumors in a high accuracy.

We here perform a systematic bioinformatic analysis to uncover the role of sorting nexin (SNX) family in clinical outcome of gastric cancer (GC). Comprehensive bioinformatic analysis were realized with online tools such as TCGA, GEO, String, Timer, cBioportal and Kaplan–Meier Plotter. Statistical analysis was conducted with R language or Perl, and artificial neural network (ANN) model was established using Python. Our analysis demonstrated that SNX4/5/6/7/8/10/13/14/15/16/20/22/25/27/30 were higher expressed in GC, whereas SNX1/17/21/24/33 were in the opposite expression profiles. GSE66229 was employed as verification of the differential expression analysis based on TCGA. Clustering results gave the relative transcriptional levels of 30 SNXs in tumor, and it was totally consistent to the inner relevance of SNXs at mRNA level. Protein–Protein Interaction map showed closely and complex connection among 33 SNXs. Tumor immune infiltration analysis asserted that SNX1/3/9/18/19/21/29/33, SNX1/17/18/20/21/29/31/33, SNX1/2/3/6/10/18/29/33, and SNX1/2/6/10/17/18/20/29 were strongly correlated with four kinds of survival related tumor-infiltrating immune cells, including cancer associated fibroblast, endothelial cells, macrophages and Tregs. Kaplan–Meier survival analysis based on GEO presented more satisfactory results than that based on TCGA-STAD did, and all the 29 SNXs were statistically significant, SNX23/26/28 excluded. SNXs alteration contributed to microsatellite instability (MSI) or higher level of MSI-H (hyper-mutated MSI or high level of MSI), and other malignancy encompassing mutation of TP53 and ARID1A, as well as methylation of MLH1.The multivariate cox model, visualized as a nomogram, performed excellently in patients risk classification, for those with higher risk-score suffered from shorter overall survival (OS). Compared to previous researches, our ANN models showed a predictive power at a middle-upper level, with AUC of 0.87/0.72, 0.84/0.72, 0.90/0.71 (GSE84437), 0.98/0.66, 0.86/0.70, 0.98/0.71 (GSE66229), 0.94/0.66, 0.83/0.71, 0.88/0.72 (GSE26253) corresponding to one-, three- and five-year OS and recurrence free survival (RFS) estimation, especially ANN model built with GSE66229 including exclusively SNXs as input data. The SNX family shows great value in postoperative survival evaluation of GC, and ANN models constructed using SNXs transcriptional data manifesting excellent predictive power in both OS and RFS prediction works as convincing verification to that.

The purposes of this study were to analyse the spatiotemporal variations in greenhouse gas diffusive fluxes at the sediment–water interface of sewage-draining rivers and natural rivers, and investigate the factors responsible for the changes in greenhouse gas diffusive fluxes. Greenhouse gas diffusive fluxes at the sediment–water interface of rivers in Tianjin city (Haihe watershed) were investigated during July and October 2014, and January and April 2015 by laboratory incubation experiments. The influence of environmental variables on greenhouse gas diffusive fluxes was evaluated by Spearman’s correlation analysis and a multiple stepwise regression analysis. Sewage-draining rivers were more seriously polluted by human sewage discharge than natural rivers. The greenhouse gas diffusive fluxes at the sediment–water interface exhibited obvious spatiotemporal variations. The mean absolute value of the CO2 diffusive fluxes was seasonally variable with spring>winter>fall>summer, while the mean absolute values of the CH4 and N2O diffusive fluxes were both higher in summer and winter, and lower in fall and spring. The annual mean values of the CO2, CH4 and N2O diffusive fluxes at the sewage-draining river sediment–water interface were − 123.26 ± 233.78 μmol m−2 h−1, 1.88 ± 6.89 μmol m−2 h−1 and 1505.03 ± 2388.46 nmol m−2 h−1, respectively, which were 1.22, 4.37 and 134.50 times those at the natural river sediment–water interface, respectively. The spatial variation of the N2O diffusive fluxes in the sewage-draining rivers and the natural rivers was the most significant. As a general rule, the more serious the river pollution was, the greater the diffusive fluxes of the greenhouse gases were. On average for the whole year, the river sediment was the sink of CO2 and the source of CH4 and N2O. There were positive correlations among the CO2, CH4 and N2O diffusive fluxes. The main influencing factor for CO2 and N2O diffusive fluxes was the water temperature of the overlying water; however, the key factors for CH4 diffusive fluxes were the Eh of the sediment and the NH4+-N of the overlying water. River sediment can be either a sink or a source of greenhouse gases, which varies in different levels of pollution and different seasons. Human sewage discharge has greatly affected the carbon and nitrogen cycling of urban rivers.

Land use regression (LUR) models are mainly used for the simulation and prediction of conventional atmospheric pollutants. Whether the LUR models can be expanded to study more toxic and hazardous pollutants (such as heavy metals) remains to be verified. Combined with the factors of road, land use type, population, pollution enterprise, meteorology, and terrain, the LUR models were used to simulate the spatial distribution characteristics of heavy metals in road dust and determine the main influencing factors. Samples of road surface dust were collected from 144 evenly distributed points in Tianjin, China, with 108 modelling points and 36 verification points. The R

Data Availability Statement: The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation. Supplementary Material: The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fped.2022.739296/full#supplementary-material Copyright © 2022 Liu, Evans, Wang, Hu, Tong, Li, Tian, Li, Zhang, He and Zheng. Background: Visual impairments related to non-correctable vision loss, including blindness and low vision, have been consistently shown to lower a person's health-related quality of life. This study assessed the reliability, validity, and discrimination of the Quality of Life Scale for Children with Visual Impairments (QOLS-CVI) in China. Methods: The Pediatric Quality of Life Inventory™ 4.0 and World Health Organization Quality of Life-Disability Scale for physical disability were selected to define conceptual frameworks and item libraries based on relevant existing studies. According to two rounds of expert consultations and group discussions, some items were modified, and the draft scale was developed. Two item selection processes based on classical test theory and item response theory were used to conduct a preliminary survey and a formal survey in special schools in Shanxi and Hebei Provinces. Finally, the reliability and validity of the quality of life scale for visually impaired children in China were verified. Results: The final QOLS-CVI consisted of 38 items, 10 subdomains, and 6 domains. Reliability was verified by Cronbach's alpha coefficient, split-half reliability, and test-retest reliability (Cronbach's alpha for the full scale, 0.841; split-half reliability, 0.629; and test–retest reliability, 0.888). The validity results showed that the multidimensional scale met expectations: exploratory factor analysis and confirmatory factor analysis indicated good fitting models for children with visual impairments. Conclusions: The QOLS-CVI was determined to be reliable and valid and to have strong feasibility and effectiveness. This scale can be used as an evaluation tool to study the QOL and social-participation ability of children with visual impairments. National Natural Science Foundation of China (approval number 71203126).

The lipid-coated mesoporous silica nanoparticles (LMSNs) that can synergistically harness the advantages and mitigate the disadvantages of the liposomes and MSNs are considered potential drug carriers. So far, several methods have been developed to prepare LMSNs, including vesicle fusion, thin-film hydration, and solvent exchange. Despite their wide application in LMSN preparation, these methods are short of detailed elaboration and comparison, which hinders their further development. In this review, for the first time, the three methods are systematically summarized, including their mechanisms, influence factors, advantages, and limitations. Although these methods are all based on lipid self-assembly, there is still a difference between them. In order to efficiently prepare LMSNs, we proposed that a suitable method should be selected based on the actual situation. It is conceivable that the elaboration and comparison in this review will make these methods easy to be understood and provide guidance for the design of LMSNs as drug carriers.

In urban North China, nitrate ( NO 3 − ) is a primary contributor to haze formation. So far, the production processes and source apportionments of atmospheric NO 3 − during the heating season (i.e. the wintertime) have not yet been well understood. This study determined δ15N– NO 3 − , δ18O– NO 3 − , and Δ17O– NO 3 − of aerosol samples to compare the potential sources and formation pathways of atmospheric NO 3 − during heating (November to March) and non-heating (April to May) seasons. Combining stable isotope composition with the MixSIAR model based on Δ17O– NO 3 − showed that NO3 + DMS/HC (dimethyl sulfate/hydrocarbon) pathway was the dominant process of atmospheric nitrate formation during the heating season (mean = 52.88 ± 16.11%). During the non-heating season, the contributions of NO3 + DMS/HC (mean = 37.89 ± 13.57%) and N2O5 + H2O (mean = 35.24 ± 3.75%) pathways were comparable. We found that Δ17O– NO 3 − was negatively correlated with wind speed and positively correlated with relative humidity during the heating season, possibly associated with the sources and production of atmospheric NO 3 − . In specific, in a dust storm event, the very low Δ17O– NO 3 − is likely associated with particles from land surface. Under the premise of considering 15N fractionation, the constraint-based on δ15N– NO 3 − illustrated that coal combustion was the major source of NO x emission during the heating season, and the relative contribution of coal combustion decreased rapidly from the heating season (mean = 42.56 ± 15.50%) to the non-heating season (mean = 21.86 ± 4.91%). Conversely, the proportion of NOx emitted by soil microbes rose significantly from the heating (mean = 9.67 ± 5.99%) to non-heating season (mean = 24.02 ± 11.65%). This study revealed differences in the sources and formation processes of atmospheric NO 3 − during the heating and non-heating seasons, which are of significance to atmospheric nitrogen oxide/nitrate pollution mitigation.

In order to provide more scientific guidance for wetland bird protection, this study addressed the dynamics of the bird community sorted by ecotypes, classifications and threat categories from 2015 to 2019, and non-metric multidimensional scaling analysis, generalized additive models and the Mantel test were used to examine the relationships between bird communities and habitat types. The results showed that: (1) The abundance of birds peaked in 2017 at 88,258 individuals and then declined. Moreover, there was an inverse trend between species richness and abundance of birds, meaning greater abundance is associated with fewer species. (2) Swimming birds were dominant ecotypes and Anseriformes possessed the highest abundance. It was noteworthy that the abundance of critically endangered birds (Aythya baeri and Grus leucogeranus) and the species richness of endangered birds increased. (3) Building land and farmland had dominant impacts on the composition of bird community. Wading birds and birds in Gruiformes were significantly impacted by building land and farmland, and near threatened species were substantially influenced by farmland. Therefore, maintaining good connectivity between protected areas and surrounding areas is one of the best ways to effectively manage biodiversity of the target area. This research may provide a broader insight for coastal wetland bird habitat management and bird diversity preservation.

The inverse scattering transformation for a generalized derivative nonlinear Schrödinger (GDNLS) equation is studied via the Riemann–Hilbert approach. In the direct scattering process, we perform the spectral analysis of the Lax pair associated with a 2 × 2 matrix spectral problem for the GDNLS equation. Then, the corresponding Riemann–Hilbert problem is constructed. In the inverse scattering process, we obtain an N-soliton solution formula for the GDNLS equation by solving the Riemann–Hilbert problem with the reflection-less case. In addition, we express the N-soliton solution of the GDNLS equation as determinant expression.

Recently, mixed bromine/chlorine transformation products of tetrabromobisphenol A (Cl

The large increase in the number of tourists brings challenges to the tourist carrying capacity of tourist destinations. By constructing a tourism carrying capacity indicator system and a coupling coordination model, we calculate and compare the development of tourism carrying capacity and the coupling coordination between all first-class indicators of tourism carrying capacity for provinces and cities in China. We find that the tourism carrying capacity and the coupling coordination between all first-class indicators of tourism carrying capacity for provinces and cities in China both showed an upward trend from 2008 to 2017, but the development was not balanced. In coastal provinces, their development level was high although lately showing a downward trend. In the provinces of the northwest China, their development level is low, and their development speed is relatively slow. The provinces and cities in the middle reaches of the Yangtze River and the southwest China recorded the fastest growth rate. In addition, we found that the development of tourism carrying capacity is closely related to coupling coordination between all first-class indicators of tourism carrying capacity.