Publications by authors named "Chengming Li"

44 Publications

Computed Tomography-Based Delta-Radiomics Analysis for Discriminating Radiation Pneumonitis in Patients With Esophageal Cancer After Radiation Therapy.

Int J Radiat Oncol Biol Phys 2021 May 8. Epub 2021 May 8.

Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China. Electronic address:

Purpose: Our purpose was to construct a computed tomography (CT)-based delta-radiomics nomogram and corresponding risk classification system for individualized and accurate estimation of severe acute radiation pneumonitis (SARP) in patients with esophageal cancer (EC) after radiation therapy.

Methods And Materials: Four hundred patients with EC were enrolled from 2 independent institutions and were divided into the training (n = 200) and validation (n = 200) cohorts. Eight hundred fifty radiomics features of lung were extracted from treatment planning images, including the positioning CT before radiation therapy (CT) and the resetting CT after receiving 40 to 45 Gy (CT). The longitudinal net changes in radiomics features from CT to CT were calculated and defined as delta-radiomics features. Least absolute shrinkage and selection operator algorithm was performed to features selection and delta-radiomics signature building. Integrating the signature with multidimensional clinicopathologic, dosimetric, and hematological predictors of SARP, a novel CT-based delta-radiomics nomogram was established according to multivariate analysis. The clinical application values of nomogram were both evaluated in the training and validation cohorts by concordance index, calibration curves, and decision curve analysis. Recursive partitioning analysis was used to generate a risk classification system.

Results: The delta-radiomics signature consisting of 24 features was significantly associated with SARP status (P < .001). Incorporating it with other high-risk factors, Subjective Global Assessment score, pulmonary fibrosis score, mean lung dose, and systemic immune inflammation index, the developed delta-radiomics nomogram showed increased improvement in SARP discrimination accuracy with concordance index of 0.975 and 0.921 in the training and validation cohorts, respectively. Calibration curves and decision curve analysis confirmed the satisfactory clinical feasibility and utility of nomogram. The risk classification system displayed excellent performance on identifying SARP occurrence (P < .001).

Conclusions: The delta-radiomics nomogram and risk classification system as low-cost and noninvasive means exhibited superior predictive accuracy and provided individualized probability of SARP stratification for patients with EC.
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http://dx.doi.org/10.1016/j.ijrobp.2021.04.047DOI Listing
May 2021

Structural basis of tetanus toxin neutralization by native human monoclonal antibodies.

Cell Rep 2021 May;35(5):109070

Department of Cell Biology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Trinomab Biotech Co., Ltd, Zhuhai 519040, China; Institute of Biomedicine, Jinan University, Guangzhou 510632, China. Electronic address:

Four potent native human monoclonal antibodies (mAbs) targeting distinct epitopes on tetanus toxin (TeNT) are isolated with neutralization potency ranging from approximately 17 mg to 6 mg each that are equivalent to 250 IU of human anti-TeNT immunoglobulin. TT0170 binds fragment B, and TT0069 and TT0155 bind fragment AB. mAb TT0067 binds fragment C and blocks the binding of TeNT to gangliosides. The co-crystal structure of TT0067 with fragment C of TeNT at a 2.0-Å resolution demonstrates that mAb TT0067 directly occupies the W pocket of one of the receptor binding sites on TeNT, resulting in blocking the binding of TeNT to ganglioside on the surface of host cells. This study reveals at the atomic level the mechanism of action by the TeNT neutralizing antibody. The key neutralization epitope on the fragment C of TeNT identified in our work provides the critical information for the development of fragment C of TeNT as a better and safer tetanus vaccine.
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http://dx.doi.org/10.1016/j.celrep.2021.109070DOI Listing
May 2021

An Improved Method for Stable Feature Points Selection in Structure-from-Motion Considering Image Semantic and Structural Characteristics.

Sensors (Basel) 2021 Apr 1;21(7). Epub 2021 Apr 1.

College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266590, China.

Feature matching plays a crucial role in the process of 3D reconstruction based on the structure from motion (SfM) technique. For a large collection of oblique images, feature matching is one of the most time-consuming steps, and the matching result directly affects the accuracy of subsequent tasks. Therefore, how to extract the reasonable feature points robustly and efficiently to improve the matching speed and quality has received extensive attention from scholars worldwide. Most studies perform quantitative feature point selection based on image Difference-of-Gaussian (DoG) pyramids in practice. However, the stability and spatial distribution of feature points are not considered enough, resulting in selected feature points that may not adequately reflect the scene structures and cannot guarantee the matching rate and the aerial triangulation accuracy. To address these issues, an improved method for stable feature point selection in SfM considering image semantic and structural characteristics is proposed. First, the visible-band difference vegetation index is used to identify the vegetation areas from oblique images, and the line feature in the image is extracted by the optimized line segment detector algorithm. Second, the feature point two-tuple classification model is established, in which the vegetation area recognition result is used as the semantic constraint, the line feature extraction result is used as the structural constraint, and the feature points are divided into three types. Finally, a progressive selection algorithm for feature points is proposed, in which feature points in the DoG pyramid are selected by classes and levels until the number of feature points is satisfied. Oblique images of a 40-km area in Dongying city, China, were used for validation. The experimental results show that compared to the state-of-the-art method, the method proposed in this paper not only effectively reduces the number of feature points but also better reflects the scene structure. At the same time, the average reprojection error of the aerial triangulation decrease by 20%, the feature point matching rate increase by 3%, the selected feature points are more stable and reasonable.
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http://dx.doi.org/10.3390/s21072416DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8036694PMC
April 2021

Synthesis of Imidazole-Based [30]Heptaphyrin and Stable Figure-Eight [60]Tetradecaphyrins via [5 + 2] Condensations in One Pot.

Org Lett 2021 05 22;23(9):3746-3750. Epub 2021 Apr 22.

Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, Sichuan 610064, PR China.

Derived from a Pd-catalyzed oxidative C-H/C-H coupling reaction, two giant imidazole-based [60]tetradecaphyrins adopting stable figure-eight geometry together with one [30]heptaphyrin are obtained by [5 + 2] MacDonald condensations in one pot. The directional imidazole is believed to play a vital role for the diverse cyclization and conformation stabilization.
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http://dx.doi.org/10.1021/acs.orglett.1c01156DOI Listing
May 2021

The Predictive Value of Tumor Volume and Its Change on Short-Term Outcome for Esophageal Squamous Cell Carcinoma Treated With Radiotherapy or Chemoradiotherapy.

Front Oncol 2020 1;10:586145. Epub 2021 Feb 1.

Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China.

Objectives: To investigate the tumor volume and its change on short-term outcome in esophageal squamous cell carcinoma (ESCC) patients who underwent definitive radiotherapy or chemoradiotherapy.

Methods And Materials: All data were retrospectively collected from 418 ESCC patients who received radiotherapy or chemoradiotherapy at our institution between 2015 and 2019. Short-term outcome using the treatment response evaluation was assessed according to the RECIST 1.1. The tumor volume change rate (TVCR) was defined as follows: TVCR {1 [gross tumor volume (GTV) at shrinking irradiation field planning)]/(GTV at the initial treatment planning)} ×100%. Chi square test was used to compare the clinic characteristics in different TVCR groups, and the difference between initial GTV (GTVi) and shrinking GTV (GTVs) was compared using Wilcoxon's sign rank test. Logistic regression analysis and Spearman correlation was performed.

Results: There was a significant decrease in GTVi compared to GTVs ( < 0.001). In univariate analysis, age, cT-stage, TNM stage, treatment modality, GTVi, and TVCR were associated with short-term outcome (all 0.05). In multivariate analysis, gender and TVCR were statistically significant ( = 0.010, <0.001) with short-term outcome, and the combined predictive value of gender and TVCR exceeded that of TVCR (AUC, 0.876 0.855).

Conclusions: TVCR could serve to forecast short-term outcome of radiotherapy or chemoradiotherapy in ESCC. It was of great significance to guide the individualized treatment of ESCC.
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http://dx.doi.org/10.3389/fonc.2020.586145DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7901880PMC
February 2021

An elimination method for isolated meshes in a road network considering stroke edge feature.

PLoS One 2020 30;15(11):e0239828. Epub 2020 Nov 30.

Chinese Academy of Surveying and Mapping, Beijing, China.

The road network is the skeletal element of topographic maps at different scales. In general, urban roads are connected by road segments, thus forming a series of road meshes. Mesh elimination is a key step in evaluating the importance of roads during the road network data management and a prerequisite to the implementation of continuous multiscale spatial representation of road networks. The existing mesh-based method is an advanced road elimination method whereby meshes with the largest density are sequentially selected and road segments with the least importance in each mesh are eliminated. However, the road connectivity and integrity may be destroyed in specific areas by this method because some eliminated road segments could be located in the middle of road strokes. Therefore, this paper proposed an elimination method for isolated meshes in a road network considering stroke edge feature. First, small meshes were identified by using mesh density thresholds, which can be obtained by the sample data statistical algorithm. Thereafter, the small meshes related to the edge segments of road strokes were taken out and defined as stroke edge meshes, and the remaining small meshes were defined as stroke non-edge meshes. Second, by computing the mesh density of all stroke edge meshes, the mesh with the largest density was selected as the starting mesh, and the least important edge segment in the mesh was eliminated. The difference between the existing mesh-based method and the proposed method is that the starting mesh is a stroke edge mesh, not any given small mesh, and the eliminated segment is just only one of edge segments of strokes not chosen from among all segments. Third, mesh elimination was implemented by iteratively processing the stroke edge meshes with the largest mesh density until all of them were eliminated and their mesh density exceeded the threshold. The stroke non-edge meshes were directly preserved. Finally, a 1:10,000 topographic road map of an area in Jiangsu Province of China was used for validation. The experimental results show that for all stroke non-edge meshes and 23% of the stroke edge meshes, compared to the mesh-based method, the road stroke connectivity and integrity of road strokes were better preserved by the proposed method, and the remaining 77% of the elimination results for the stroke edge meshes were the same under the two methods.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0239828PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7703882PMC
January 2021

A nomogram to predict short-term outcome of radiotherapy or chemoradiotherapy based on pre/post-treatment inflammatory biomarkers and their dynamic changes in esophageal squamous cell carcinoma.

Int Immunopharmacol 2021 Jan 18;90:107178. Epub 2020 Nov 18.

Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China; Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China. Electronic address:

Objective: We initially aimed to investigate pre/post-treatment inflammatory biomarkers (pre/post-IBs) and their dynamic changes (delta-IBs) on the short-term outcome (STO) of radiotherapy or chemoradiotherapy in esophageal squamous cell carcinoma (ESCC). Furthermore, a nomogram was built to provide an accurate prediction of STO.

Methods: The STO using the treatment response evaluation was assessed according to RECIST 1.1 at 1 month after radiotherapy or chemoradiotherapy. The IBs (absolute lymphocyte counts (ALC), neutrophil/lymphocyte (NLR), platelet/lymphocyte (PLR), and lymphocyte/monocyte (LMR)) and clinical variables were collected and analyzed from 398 ESCC patients at Shandong Cancer Hospital between 2015 and 2019. The nomogram was then established for predicting STO.

Results: Pre-ALC and pre-LMR significantly increased, pre-NLR and pre-PLR significantly decreased during radiotherapy or chemoradiotherapy (all P < 0.001). Meanwhile, there was a positive correlation between delta-NLR as well as delta-PLR (r = 0.621) and delta-LMR (r = 0.613), whereas a negatively correlated between delta-LMR and delta-PLR (r = -0.573). Multivariate analysis indicated that gender [OR, 0.473; 95%CI, 0.274-0.816; P = 0.007], pre-ALC [OR, 0.554; 95%CI, 0.335-0.915; P = 0.021], pre-NLR [OR, 3.176; 95%CI, 1.733-5.823; P < 0.001], post-NLR [OR, 2.418; 95%CI, 1.271-4.600; P = 0.007] and delta-NLR [OR, 1.929; 95%CI, 1.035-3.595; P = 0.039] were statistically significant with STO. And c-index of the nomogram established by combining all independent predictors for STO was 0.770 [95%CI, 0.719-0.820].

Conclusion: Pre-NLR, pre-ALC, post-NLR, and delta-NLR were significant with STO in ESCC patients treated with radiotherapy or chemoradiotherapy. Further, pre-NLR had the best predictive value, and the developed nomogram with superior prediction ability for STO could assist in patients counseling and guide to make individual treatments.
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http://dx.doi.org/10.1016/j.intimp.2020.107178DOI Listing
January 2021

Mechanistic Insights to the Binding of Antibody CR3022 Against RBD from SARS-CoV and HCoV-19/SARS-CoV-2: A Computational Study.

Comb Chem High Throughput Screen 2020 10 26. Epub 2020 Oct 26.

Institute of Biomedicine, Jinan University, Guangzhou, 510632. China

Aims & Objective: Corona Virus Disease 2019 (COVID-19) caused by the human coronavirus 2019 (HCoV-19, also known as SARS-CoV-2) infection is currently in a global outbreak. COVID-19 has posed a huge threat to public health and economic stability worldwide. CR3022, a human monoclonal neutralizing antibody isolated from a Severe Acute Respiratory Syndrome (SARS) recovery patient, was confirmed to be able to bind the S protein of HCoV-19 with a certain degree of neutralizing activity. Crystal structural information indicated that CR3022 could bind to the epitope on the receptor binding domain (RBD) of HCoV-19, whose epitope consists of 28 amino acids, and 24 of them are conserved in SARS-CoV of SARS. However, the crystal structure is only a static conformation at a certain moment in time, and it cannot provide dynamic details of the interaction between antigen and antibody.

Methods: In this study, molecular dynamics (MD) simulation combined with MM/PBSA and CAS methods were performed to investigate the binding mechanism of binding of CR3022 against SARS-CoV-RBD and HCoV-19-RBD in order to determine their holographic dynamic information.

Results: It was found that the CR3022-SARS-CoV-RBD complex was more stable during 100ns MD run than that of the CR3022-HCoV19-RBD system. There were common conservative amino acids on the β2 sheet of RBD, including Tyr369, Phe377, Lys378, Tyr380, Gly381, Lys386, Leu390 and others. These conservative amino acids play significant roles in the binding process of CR3022 antibody against SARS-CoV-RBD and HCoV-19-RBD. It was also found that the binding mode of CR3022 to its native target SARS-CoV-RBD is more comprehensive and uniform. Moreover, the β2 sheet residue Thr385 and non-β2 sheet residues Arg408 and Asp428 of the CR3022- SARS-CoV-RBD system were found to be crucial for their binding affinities, thus forming a special conformational epitope. However, these key amino acids are not present in the CR3022-HCoV-19-RBD system. The binding mode of CR3022 and HCoV-19-RBD is similar to that of SARS-CoV-RBD, but the deficiency of crucial hydrogen-bonds and salt-bridges. Therefore, the binding of CR3022 and HCoV19-RBD only draws on the partial mode of the binding of CR3022 and SARS-CoV-RBD, so there is a loss of affinity.

Conclusion: Thus, in order to better fight the epidemic of COVID-19 with the CR3022 antibody, this antibody needs to further improve the neutralization efficiency of HCoV-19 through mutation of it's CDR region.
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http://dx.doi.org/10.2174/1386207323666201026160500DOI Listing
October 2020

Dearomatizing [4+1] Spiroannulation of Naphthols: Discovery of Thermally Activated Delayed Fluorescent Materials.

Angew Chem Int Ed Engl 2021 Feb 21;60(7):3493-3497. Epub 2021 Jan 21.

Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China.

Disclosed here is a palladium-catalyzed direct [4+1] spiroannulation of ortho-C-H bonds of naphthols with cyclic diaryliodonium salts to construct spirofluorenyl naphthalenones (SFNP) under mild reaction conditions. This spiroannulation directly transforms the hydroxy group into a carbonyl group, and also tolerates reactive functional groups such as the halo groups, which provide an opportunity to rapidly assemble structurally new thermally activated delayed fluorescent (TADF) materials that feature a carbonyl group with an adjacent spirofluorenyl unit as the acceptor. As an illustrated example, the OLED device utilizing the assembled DMAC-SFNP as the host material exhibits a low turn-on voltage of 2.5 V and an ultra-high external quantum efficiency of 32.2 %. This work provides inspiration for structurally new TADF materials, and also displays the potential of C-H activation as a synthetic strategy for the innovation of optoelectronic materials.
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http://dx.doi.org/10.1002/anie.202012842DOI Listing
February 2021

An Ensemble of Generation- and Retrieval-based Image Captioning with Dual Generator Generative Adversarial Network.

IEEE Trans Image Process 2020 Oct 15;PP. Epub 2020 Oct 15.

Image captioning, which aims to generate a sentence to describe the key content of a query image, is an important but challenging task. Existing image captioning approaches can be categorised into two types: generation-based methods and retrieval-based methods. Retrieval-based methods describe images by retrieving pre-existing captions from a repository. Generation-based methods synthesize a new sentence that verbalizes the query image. Both ways have certain advantages but suffer from their own disadvantages. In the paper, we propose a novel EnsCaption model, which aims at enhancing an ensemble of retrieval-based and generation-based image captioning methods through a novel dual generator generative adversarial network. Specifically, EnsCaption is composed of a caption generation model that synthesizes tailored captions for the query image, a caption re-ranking model that retrieves the best-matching caption from a candidate caption pool consisting of generated captions and pre-retrieved captions, and a discriminator that learns the multi-level difference between the generated/retrieved captions and the ground-truth captions. During the adversarial training process, the caption generation model and the caption re-ranking model provide improved synthetic and retrieved candidate captions with high ranking scores from the discriminator, while the discriminator based on multi-level ranking is trained to assign low ranking scores to the generated and retrieved image captions. Our model absorbs the merits of both generation-based and retrieval-based approaches. We conduct comprehensive experiments to evaluate the performance of EnsCaption on two benchmark datasets: MSCOCO and Flickr-30K. Experimental results show that EnsCaption achieves impressive performance compared to the strong baseline methods.
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http://dx.doi.org/10.1109/TIP.2020.3028651DOI Listing
October 2020

FLASH Investigations Using Protons: Design of Delivery System, Preclinical Setup and Confirmation of FLASH Effect with Protons in Animal Systems.

Radiat Res 2020 12;194(6):656-664

Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.

Extremely high-dose-rate irradiation, referred to as FLASH, has been shown to be less damaging to normal tissues than the same dose administrated at conventional dose rates. These results, typically seen at dose rates exceeding 40 Gy/s (or 2,400 Gy/min), have been widely reported in studies utilizing photon or electron radiation as well as in some proton radiation studies. Here, we report the development of a proton irradiation platform in a clinical proton facility and the dosimetry methods developed. The target is placed in the entry plateau region of a proton beam with a specifically designed double-scattering system. The energy after the double-scattering system is 227.5 MeV for protons that pass through only the first scatterer, and 225.5 MeV for those that also pass through the second scatterer. The double-scattering system was optimized to deliver a homogeneous dose distribution to a field size as large as possible while keeping the dose rate >100 Gy/s and not exceeding a cyclotron current of 300 nA. We were able to obtain a collimated pencil beam (1.6 × 1.2 cm2 ellipse) at a dose rate of ∼120 Gy/s. This beam was used for dose-response studies of partial abdominal irradiation of mice. First results indicate a potential tissue-sparing effect of FLASH.
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http://dx.doi.org/10.1667/RADE-20-00068.1DOI Listing
December 2020

An Effective Hybrid Learning Model for Real-Time Event Summarization.

IEEE Trans Neural Netw Learn Syst 2020 Aug 31;PP. Epub 2020 Aug 31.

Real-time event summarization (RES) aims at extracting a handful of document updates from an overwhelming document stream as the real-time event summary that tracks and summarizes the evolving event of interest. It has been attracting much attention, especially with the growth of streaming applications. Despite the effectiveness of previous studies, obtaining relevant, nonredundant, and timely event summaries remains challenging in real-life applications. This study proposes an effective Hybrid learning model for RES (HRES), which attempts to resolve all three challenges (i.e., nonredundancy, relevance, and timeliness) of RES in a unified framework. The main idea is to: 1) exploit the factual background knowledge from the knowledge base (KB) to capture the informative knowledge and implicit information from the input document/query for better text matching; 2) design a memory network to memorize the input facts temporally from the historical document stream and avoid pushing redundant facts in subsequent timesteps; 3) leverage relevance prediction as an auxiliary task to strengthen the document modeling and help to extract relevant documents; and 4) consider both historical dependencies and future uncertainty of the real-time document stream by exploiting the reinforcement learning technique. Extensive experiments demonstrate that HRES has robust superiority over competitors and gains the state-of-the-art results.
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http://dx.doi.org/10.1109/TNNLS.2020.3017747DOI Listing
August 2020

Investigation of the Impact of Land-Use Distribution on PM in Weifang: Seasonal Variations.

Int J Environ Res Public Health 2020 07 16;17(14). Epub 2020 Jul 16.

Chinese Academy of Surveying and Mapping, Beijing 100830, China.

As air pollution becomes highly focused in China, the accurate identification of its influencing factors is critical for achieving effective control and targeted environmental governance. Land-use distribution is one of the key factors affecting air quality, and research on the impact of land-use distribution on air pollution has drawn wide attention. However, considerable studies have mostly used linear regression models, which fail to capture the nonlinear effects of land-use distribution on PM (fine particulate matter with a diameter less than or equal to 2.5 microns) and to show how impacts on PM vary with land-use magnitudes. In addition, related studies have generally focused on annual analyses, ignoring the seasonal variability of the impact of land-use distribution on PM, thus leading to possible estimation biases for PM. This study was designed to address these issues and assess the impacts of land-use distribution on PM in Weifang, China. A machine learning statistical model, the boosted regression tree (BRT), was applied to measure nonlinear effects of land-use distribution on PM, capture how land-use magnitude impacts PM across different seasons, and explore the policy implications for urban planning. The main conclusions are that the air quality will significantly improve with an increase in grassland and forest area, especially below 8% and 20%, respectively. When the distribution of construction land is greater than around 10%, the PM pollution can be seriously substantially increased with the increment of their areas. The impact of gardens and farmland presents seasonal characteristics. It is noted that as the weather becomes colder, the inhibitory effect of vegetation distribution on the PM concentration gradually decreases, while the positive impacts of artificial surface distributions, such as construction land and roads, are aggravated because leaves drop off in autumn (September-November) and winter (December-February). According to the findings of this study, it is recommended that Weifang should strengthen pollution control in winter, for instance, expand the coverage areas of evergreen vegetation like Zucc. and Thunb, and increase the width and numbers of branches connecting different main roads. The findings also provide quantitative and optimal land-use planning and strategies to minimize PM pollution, referring to the status of regional urbanization and greening construction.
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http://dx.doi.org/10.3390/ijerph17145135DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7400403PMC
July 2020

Hierarchical Human-Like Deep Neural Networks for Abstractive Text Summarization.

IEEE Trans Neural Netw Learn Syst 2021 Jun 2;32(6):2744-2757. Epub 2021 Jun 2.

Developing an abstractive text summarization (ATS) system that is capable of generating concise, appropriate, and plausible summaries for the source documents is a long-term goal of artificial intelligence (AI). Recent advances in ATS are overwhelmingly contributed by deep learning techniques, which have taken the state-of-the-art of ATS to a new level. Despite the significant success of previous methods, generating high-quality and human-like abstractive summaries remains a challenge in practice. The human reading cognition, which is essential for reading comprehension and logical thinking, is still relatively new territory and underexplored in deep neural networks. In this article, we propose a novel Hierarchical Human-like deep neural network for ATS (HH-ATS), inspired by the process of how humans comprehend an article and write the corresponding summary. Specifically, HH-ATS is composed of three primary components (i.e., a knowledge-aware hierarchical attention module, a multitask learning module, and a dual discriminator generative adversarial network), which mimic the three stages of human reading cognition (i.e., rough reading, active reading, and postediting). Experimental results on two benchmark data sets (CNN/Daily Mail and Gigaword) demonstrate that HH-ATS consistently and substantially outperforms the compared methods.
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http://dx.doi.org/10.1109/TNNLS.2020.3008037DOI Listing
June 2021

Identifying optimal first-line interventions for advanced non-small cell lung carcinoma according to PD-L1 expression: a systematic review and network meta-analysis.

Oncoimmunology 2020 7;9(1):1746112. Epub 2020 Apr 7.

Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China.

This network meta-analysis (NMA), based on one phase II and nine phase III studies, involving 6,124 patients with metastatic NSCLC, indirectly compares Atezolizumab + Bevacizumab + chemotherapy (ABC), Atezolizumab + chemotherapy (AC), Pembrolizumab + chemotherapy (PC), Pembrolizumab alone, Bevacizumab + chemotherapy (BC) and chemotherapy alone. Each of these is recommended as front-line interventions, according to the US FDA and the European Medicines Agency (EMA) for advanced NSCLC without EGFR mutation or ALK rearrangement. Studies were identified through PubMed, EMBASE, the Cochrane Library, Medline, and abstracts found in oncology articles. Primary endpoints, i.e., progression-free survival (PFS) and overall survival (OS) with corresponding hazard ratios (HR), objective response rates (ORR) and adverse event (AEs) with odds risk (OR) were pooled according to frequentist network meta-analytical techniques. PD-L1 expression thresholds, as well as non-squamous/squamous were used to determine subgroups. Immunotherapy plus chemotherapy appeared superior to Pembrolizumab alone for PD-L1-high (i.e., TPS≥50%) NSCLC patients. BC might also be specifically recommended as an initial first-line treatment for PD-L1-high, non-squamous NSCLC patients, since BC was not inferior to Pembrolizumab alone. PC and ABC might be preferred for NSCLC patients with intermediate PD-L1 (1% ≤PD-L1, TPS<50%) expression. BC can also be tentatively recommended specifically for PD-L1-intermediate, non-squamous NSCLC patients. Combined immunotherapies can all be recommended for PD-L1-negative (i.e., TPS<1%) NSCLC patients, although especially the ABC combination for non-squamous NSCLC patients, which was superior to PC in regards of PFS. However, PC performed comparable to ABC in the whole population and in all subgroup save this one. More predictive biomarkers could be factored into further analyses to help identifying the most effective treatment regimens for specific patient groups.
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http://dx.doi.org/10.1080/2162402X.2020.1746112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7153822PMC
April 2020

A Hybrid Method for Predicting Traffic Congestion during Peak Hours in the Subway System of Shenzhen.

Sensors (Basel) 2019 Dec 25;20(1). Epub 2019 Dec 25.

School of Resources and Environmental Science, Wuhan University, Wuhan 430079, China.

Traffic congestion, especially during peak hours, has become a challenge for transportation systems in many metropolitan areas, and such congestion causes delays and negative effects for passengers. Many studies have examined the prediction of congestion; however, these studies focus mainly on road traffic, and subway transit, which is the main form of transportation in densely populated cities, such as Tokyo, Paris, and Beijing and Shenzhen in China, has seldom been examined. This study takes Shenzhen as a case study for predicting congestion in a subway system during peak hours and proposes a hybrid method that combines a static traffic assignment model with an agent-based dynamic traffic simulation model to estimate recurrent congestion in this subway system. The homes and work places of the residents in this city are collected and taken to represent the traffic demand for the subway system of Shenzhen. An origin-destination (OD) matrix derived from the data is used as an input in this method of predicting traffic, and the traffic congestion is presented in simulations. To evaluate the predictions, data on the congestion condition of subway segments that are released daily by the Shenzhen metro operation microblog are used as a reference, and a comparative analysis indicates the appropriateness of the proposed method. This study could be taken as an example for similar studies that model subway traffic in other cities.
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http://dx.doi.org/10.3390/s20010150DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6982792PMC
December 2019

An unusual [4 + 2] fusion strategy to forge /-heteroarene-fused (quinoidal) porphyrins with intense near-infrared Q-bands.

Chem Sci 2019 Aug 17;10(30):7274-7280. Epub 2019 Jun 17.

Key Laboratory of Green Chemistry and Technology of Ministry of Education , College of Chemistry , Sichuan University , 29 Wangjiang Road , Chengdu 610064 , P. R. China . Email:

Here we present a divergent synthesis of brand-new types of /-heteroarene-fused (quinoidal) porphyrins through Rh-catalyzed β-C-H activation/annulation of 5,15-dioxoporphyrins and dioxime derivatives with alkynes, in which the synthetic disconnections are difficult to access through the commonly used intramolecular cyclization strategy. Using the -methyl oxime as a traceless oxidizing directing group, the -embedded pyridine-fused -quinoidal porphyrin and pyridinium-fused cation are formed with controllable chemoselectivity and complete -selectivity. Replacing the exocyclic oxime with a carbonyl group delivers the pyran-fused porphyrin , achieving structural conversion from a quinoidal conformation to a stable porphyrin macrocycle. Further oxidation of the expanded dimer gives the oxonium , which exhibits intense near-infrared (NIR) Q-bands up to 1300 nm. Theoretical studies demonstrate that the incorporation of a heteroatom at the -position enables more effective π-extension, resulting in a 22π aromatic ( 18π aromatic) character of pyran-fused porphyrins (/-). Compared with the commercially available methylene blue (), - exhibits a better ability ( = 0.61) to sensitize singlet oxygen (O) when irradiated with a 680 nm laser beam, and has potential as a photodynamic therapy (PDT) photosensitizer in the body's therapeutic window (650-900 nm).
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http://dx.doi.org/10.1039/c9sc01596eDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6686728PMC
August 2019

Spatiotemporal Characteristics of Air Quality across Weifang from 2014-2018.

Int J Environ Res Public Health 2019 08 27;16(17). Epub 2019 Aug 27.

Chinese Academy of Surveying and Mapping, Beijing 100830, China.

Air pollution has become a severe threat and challenge in China. Focusing on air quality in a heavily polluted city (Weifang Cty), this study aims to investigate spatial and temporal distribution characteristics of air pollution and identify the influence of weather factors on primary pollutants in Weifang over a long period from 2014-2018. The results indicate the annual Air quality Index (AQI) in Weifang has decreased since 2014 but is still far from the standard for excellent air quality. The primary pollutants are O (Ozone), PM (Particles with aerodynamic diameter ≤10 µm), and PM (Particles with aerodynamic diameter ≤10 µm); the annual concentrations of PM and PM show a significant reduction but that of O is basically unchanged. Seasonally, PM and PM show a U-shaped pattern, while O exhibits inverted U-shaped variations, and different pollutants also present different characteristics daily. Spatially, O exhibits a high level in the central region and a low level in the rural areas, while PM and PM are high in the northwest and low in the southeast. Additionally, the concentration of pollutants is greatly affected by meteorological factors, with PM being negatively correlated with temperature and wind speed, while O is positively correlated with the temperature. This research investigated the spatiotemporal characteristics of the air pollution and provided important policy advice based on the findings, which can be used to mitigate air pollution.
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http://dx.doi.org/10.3390/ijerph16173122DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6747545PMC
August 2019

Dosimetric and Radiobiological Comparison of External Beam Radiotherapy Using Simultaneous Integrated Boost Technique for Esophageal Cancer in Different Location.

Front Oncol 2019 25;9:674. Epub 2019 Jul 25.

Department of Radiation Oncology, School of Medicine, Shandong University, Jinan, China.

To compare treatment plans of intensity modulated radiotherapy (IMRT), volumetric modulated arc radiotherapy (VMAT), and helical tomotherapy (HT) with simultaneous integrated boost (SIB) technique for esophageal cancer (EC) of different locations using dosimetry and radiobiology. Forty EC patients were planned for IMRT, VMAT, and HT plans, including 10 cases located in the cervix, upper, middle, and lower thorax, respectively. Dose-volume metrics, conformity index (CI), homogeneity index (HI), tumor control probability (TCP), and normal tissue complication probability (NTCP) were analyzed to evaluate treatment plans. HT showed significant improvement over IMRT and VMAT in terms of CI ( = 0.007), HI ( < 0.001), and TCP ( < 0.001) in cervical EC. IMRT yielded more superior CI, HI and TCP compared with VMAT and HT in upper and middle thoracic EC (all < 0.05). Additionally, V30 (27.72 ± 8.67%), mean dose (1801.47 ± 989.58cGy), and NTCP (Niemierko model: 0.44 ± 0.55%; Lyman-Kutcher-Burman model: 0.61 ± 0.59%) of heart in IMRT were sharply reduced than VMAT and HT in middle thoracic EC. For lower thoracic EC, the three techniques offered similar CI and HI (all > 0.05). But VMAT dramatically lowered liver V30 (9.97 ± 2.84%), and reduced NTCP of lungs (Niemierko model: 0.47 ± 0.48%; Lyman-Kutcher-Burman model: 1.41 ± 1.07%) and liver (Niemierko model: 0.10 ± 0.08%; Lyman-Kutcher-Burman model: 0.17 ± 0.17%). HT was a good option for cervical EC with complex target coverage but little lungs and heart involvement as it achieved superior dose conformity and uniformity. Due to potentially improving tumor control and reducing heart dose with acceptable lungs sparing, IMRT was a preferred choice for upper and middle thoracic EC with large lungs involvement. VMAT could ameliorate therapeutic ratio and lower lungs and liver toxicity, which was beneficial for lower thoracic EC with little thoracic involvement but being closer to heart and liver. Individually choosing optimal technique for EC in different location will be warranted.
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http://dx.doi.org/10.3389/fonc.2019.00674DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6669560PMC
July 2019

The Interface and Mechanical Properties of a CVD Single Crystal Diamond Produced by Multilayered Nitrogen Doping Epitaxial Growth.

Materials (Basel) 2019 Aug 6;12(15). Epub 2019 Aug 6.

Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China.

In the present investigation, a nitrogen-doped multilayer homoepitaxial single crystal diamond is synthesized on a high-pressure high temperature (HPHT) Ib-type diamond substrate using the microwave plasma chemical vapor deposition (MPCVD) method. When 0.15 sccm of nitrogen was added in the gas phase, the growth rate of the doped layer was about 1.7 times that of the buffer layer, and large conical and pyramidal features are formed on the surface of the sample. Raman mapping and photoluminescence imaging of the polished cross sectional slice shows a broadband emission, with a characteristic zero phonon line (ZPL) at 575 nm in the doped layers, and large compressive stress was formed in the nitrogen-doped layers. X-ray topography shows that the defects at the interface can induce dislocation. The pyramid feature is formed at the defect, and more nitrogen-related defects are formed in the pyramid region. Thin nitrogen-doped multilayers were successfully prepared, and the thickness of the nitrogen-doped and buffer layers was about 650 nm each. The indentation measurements reveal that the thin nitrogen-doped multilayers are ultra-tough (at least ~22 MPa m), compared to the Ib-type HPHT seed substrate (~8 MPa m) and the unintentionally doped chemical vapor deposition (CVD) single crystal diamond (~14 MPa m).
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http://dx.doi.org/10.3390/ma12152492DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6696372PMC
August 2019

Hierarchical elimination selection method of dendritic river network generalization.

PLoS One 2018 3;13(12):e0208101. Epub 2018 Dec 3.

Chinese Academy of Surveying and Mapping, Beijing, China.

Dendritic river networks are fundamental elements in cartography, and the generalization of these river networks directly influences the quality of cartographic generalization. Automatic selection is a difficult and important process for river generalization that requires the consideration of semantic, geometric, topological, and structural characteristics. However, owing to a lack of effective use of river features, most existing methods lose important spatial distribution characteristics of rivers, thus affecting the selection result. Therefore, a hierarchical elimination selection method of dendritic river networks is proposed that consists of three steps. First, a directed topology tree (DTT) is investigated to realize the organization of river data and the intelligent identification of river structures. Second, based on the "180° hypothesis" and "acute angle hypothesis", each river is traced in the upstream direction from its estuary to create the stroke connections of dendritic river networks based on a consideration of the river semantics, length, and angle features, and the hierarchical relationships of a dendritic river network are then determined. Finally, by determining the total number of selected rivers, a hierarchical elimination algorithm that accounts for density differences is proposed. The reliability of the proposed method was verified using sample data tests, and the rationality and validity of the method were demonstrated in experiments using actual data.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0208101PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6277113PMC
May 2019

Spatial Concordance of Tumor Proliferation and Accelerated Repopulation from Pathologic Images to 3'-[F]Fluoro-3'-Deoxythymidine PET Images: a Basic Study Guided for PET-Based Radiotherapy Dose Painting.

Mol Imaging Biol 2019 08;21(4):713-721

Department of Radiation Oncology, Shandong Academy of Medical Science, Shandong Cancer Hospital Affiliated to Shandong University, No 440, Jiyan Road, Jinan, 250117, China.

Purpose: To assess tumor cell proliferation and repopulation during fractionated radiotherapy and investigate the spatial concordance of cell proliferation and repopulation according to the uptake of 3'-[F]fluoro-3'-deoxythymidine ([F]FLT).

Procedures: Mice bearing A549 xenograft tumors were assigned to five irradiated groups, including 3 fraction (f)/6 days (d), 6f/12d, 9f/18d, 12f/24d, and 18f/36d with 2 Gy/f irradiations performed every other day and one non-irradiated group. Serial [F]FLT positron emission tomography (PET) scans were performed at different time points as the groups finished the radiotherapy. The maximum of standard uptake values (SUVmax) were measured to confirm the likely time of tumor repopulation. A layer-by-layer comparison between SUVmax of PET images and Ki-67 LI of pathology images, including the thresholds at which maximum overlap occurred between FLT-segmented areas and cell proliferation areas were conducted to evaluate the spatial correlation.

Results: The SUVmax decreased in the 3f/6d group (P = 0.000) compared to the non-irradiated group, increased in the 6f/12d group and then gradually reduced with prolonged treatment. Proliferation changes in 6f/12d group on pathology images were also confirmed. Significant correlations were found between the SUVmax and Ki-67 LI in each in vitro tumor of cell proliferation group and accelerated repopulation group (both of the P < 0.001). Furthermore, the mean overlap region rates (ORRs) were 56.21 % and 57.82 % in the proliferation group and repopulation group, respectively. The data represented the preferable registration.

Conclusions: [F]FLT PET is a promising imaging surrogate of tumor proliferative response to fractionated radiotherapy and may help make an adaptive radiation oncology treatment plan to realize radiotherapy dose painting.
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http://dx.doi.org/10.1007/s11307-018-1292-xDOI Listing
August 2019

Synthesis of Phenalenyl-Fused Pyrylium Cations: Divergent C-H Activation/Annulation Reaction Sequence of Naphthalene Aldehydes with Alkynes.

Angew Chem Int Ed Engl 2017 10 11;56(42):13094-13098. Epub 2017 Sep 11.

Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China.

Described herein is the synthesis of stable oxonium-doped polycyclic aromatic hydrocarbons (PAHs) by the rhodium-catalyzed C-H activation/annulations of naphthalene-type aldehydes with internal alkynes. This protocol provides four divergent reaction types, including two unexpected annulations with an oxygen transposition process, which lead to diverse types of phenalenyl-fused pyrylium cations comprising a four-, five-, or six-ring-fused π-conjugated core. The annulations exhibit an exquisite regioselectivity and a high tolerance of sensitive functional groups. These PAHs feature intriguing photophysical properties such as full-color tunable fluorescence emission, high quantum yield, and positively charged core, and can be reduced easily to the phenalenyl radicals.
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http://dx.doi.org/10.1002/anie.201708127DOI Listing
October 2017

Enhancing the Performance of Quantum Dot Light-Emitting Diodes Using Room-Temperature-Processed Ga-Doped ZnO Nanoparticles as the Electron Transport Layer.

ACS Appl Mater Interfaces 2017 May 1;9(18):15605-15614. Epub 2017 May 1.

Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia.

Colloidal ZnO nanoparticle (NP) films are recognized as efficient electron transport layers (ETLs) for quantum dot light-emitting diodes (QD-LEDs) with good stability and high efficiency. However, because of the inherently high work function of such films, spontaneous charge transfer occurs at the QD/ZnO interface in such a QD-LED, thus leading to reduced performance. Here, to improve the QD-LED performance, we prepared Ga-doped ZnO NPs with low work functions and tailored band structures via a room-temperature (RT) solution process without the use of bulky organic ligands. We found that the charge transfer at the interface between the CdSe/ZnS QDs and the doped ZnO NPs was significantly weakened because of the incorporated Ga dopants. Remarkably, the as-assembled QD-LEDs, with Ga-doped ZnO NPs as the ETLs, exhibited superior luminances of up to 44 000 cd/m and efficiencies of up to 15 cd/A, placing them among the most efficient red-light QD-LEDs ever reported. This discovery provides a new strategy for fabricating high-performance QD-LEDs by using RT-processed Ga-doped ZnO NPs as the ETLs, which could be generalized to improve the efficiency of other optoelectronic devices.
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http://dx.doi.org/10.1021/acsami.7b03262DOI Listing
May 2017

In-vivo Comparison of F-FLT uptake, CT Number, Tumor Volume in Evaluation of Repopulation during Radiotherapy for Lung cancer.

Sci Rep 2017 04 7;7:46000. Epub 2017 Apr 7.

Department of Radiation Oncology, Shandong Cancer Hospital Affiliated to Shandong University, Shandong Academy of Medical Science, Jinan, China.

Accelerated repopulation has been observed in various tumors. This study was aimed to evaluate the potential of 3'-deoxy-3'-F-fluorothymidine (F-FLT) uptake and Computed Tomography Number (CTN) in monitoring tumor responses to radiotherapy compared with tumor volume (TV) changes. Tumor bearing nude mice were assigned to either irradiated daily or every second day group and then randomized to 6 sub-groups to receive 0Gy, 6Gy, 12Gy, 18Gy, 24Gy, 36Gy irradiation, respectively. TV was measured every 3 days. F-FLT micro-PET/CT scans were performed after irradiation being completed. Tumor sections were stained to calculate the immunohistochemical (Ki-67) labeling index (LI). Comparison analysis between FLT uptake parameters, CTNs, VTs and Ki-67 LI results were conducted to determine the correlation. Ki-67 LI increased significantly after 6 times of irradiation at irradiated daily group and after 3 times at irradiated every second day group, suggesting accelerated repopulation. No shrinkage of TV was noticed at two groups during irradiation delivery. Both F-FLT uptake and CTN increased significantly after irradiation of 12Gy/6f/6d and 6Gy/3f/6d. Comparison analysis found a significant relationship between Ki-67 LI and F-FLT uptake parameters as well as CTN. Both F-FLT PET and CT have the potential to reflect the tumor proliferative response during radiation delivery.
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http://dx.doi.org/10.1038/srep46000DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5384084PMC
April 2017

Uptake and subcellular distribution of triclosan in typical hydrophytes under hydroponic conditions.

Environ Pollut 2017 Jan 29;220(Pt A):400-406. Epub 2016 Sep 29.

Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou 310029, China. Electronic address:

The increasing discharge of pharmaceuticals and personal care products (PPCPs) into the environment has generated serious public concern. The recent awareness of the environmental impact of this emerging class of pollutants and their potential adverse effects on human health have been documented in many reports. However, information regarding uptake and intracellular distribution of PPCPs in hydrophytes under hydroponic conditions, and potential human exposure is very limited. A laboratory experiment was conducted using C-labeled triclosan (TCS) to investigate uptake and distribution of TCS in six aquatic plants (water spinach, purple perilla, cress, penny grass, cane shoot, and rice), and the subcellular distribution of C-TCS was determined in these plants. The results showed that the uptake and removal rate of TCS from nutrient solution by hydrophytes followed the order of cress (96%) > water spinach (94%) > penny grass (87%) > cane shoot (84%) > purple perilla (78%) > rice (63%) at the end of incubation period (192 h). The range of C-TCS content in the roots was 94.3%-99.0% of the added C-TCS, and the concentrations in roots were 2-3 orders of magnitude greater than those in shoots. Furthermore, the subcellular fraction-concentration factor (3.6 × 10-2.6 × 10 mL g), concentration (0.58-4.47 μg g), and percentage (30%-61%) of C-TCS in organelles were found predominantly greater than those in cell walls and/or cytoplasm. These results indicate that for these plants, the roots are the primary storage for TCS, and within plant cells organelles are the major domains for TCS accumulation. These findings provide a better understanding of translocation and accumulation of TCS in aquatic plants at the cellular level, which is valuable for environmental and human health assessments of TCS.
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http://dx.doi.org/10.1016/j.envpol.2016.09.076DOI Listing
January 2017

Modified Separator Using Thin Carbon Layer Obtained from Its Cathode for Advanced Lithium Sulfur Batteries.

ACS Appl Mater Interfaces 2016 Jun 15;8(25):16101-7. Epub 2016 Jun 15.

State Key Laboratory of Chemical Resource Engineering, The Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology , 15 Beisanhuan East Road, Beijing 100029, China.

The realization of a practical lithium sulfur battery system, despite its high theoretical specific capacity, is severely limited by fast capacity decay, which is mainly attributed to polysulfide dissolution and shuttle effect. To address this issue, we designed a thin cathode inactive material interlayer modified separator to block polysulfides. There are two advantages for this strategy. First, the coating material totally comes from the cathode, thus avoids the additional weights involved. Second, the cathode inactive material modified separator improve the reversible capacity and cycle performance by combining gelatin to chemically bond polysulfides and the carbon layer to physically block polysulfides. The research results confirm that with the cathode inactive material modified separator, the batteries retain a reversible capacity of 644 mAh g(-1) after 150 cycles, showing a low capacity decay of about 0.11% per circle at the rate of 0.5C.
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http://dx.doi.org/10.1021/acsami.6b04418DOI Listing
June 2016

In situ formation of nanoscale zero-value iron on fish-scale-based porous carbon for Cr(VI) adsorption.

Water Sci Technol 2016 ;73(9):2237-43

State Key Laboratory of Chemical Resource Engineering, Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, 15 Beisanhuan East Road, Beijing 100029, China E-mail:

Magnetic carbon materials that have nanoscale zero-valent iron (nZVI) supported on fish scale based hierarchical lamellar porous carbon (FHLC) is reported in this study. The nZVI on FHLC was in the form of body-centered-cubic iron (Fe) crystal. Although it was demonstrated that the specific surface area (SBET), total pore volume (Vt) and micropore volume (Vm) of the FHLC decreased with the increase of Fe contents, a certain amount of addition of iron nanoparticles on FHLC enhances the Cr(VI) adsorption properties. The as-prepared material shows faster adsorption rate and higher maximum adsorption capacity (357.14 mg/g) compared to bare FHLC (344.83 mg/g). In addition, this magnetic carbon material exhibits a high saturated magnetization (16.49 emu/g). It is indicated that the as-prepared carbon material not only can be used to remove Cr(VI) efficiently but also shows excellent magnetic separation performance from wastewater.
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http://dx.doi.org/10.2166/wst.2016.077DOI Listing
July 2016

High-temperature stable field emission of B-doped SiC nanoneedle arrays.

Nanoscale 2015 May;7(17):7585-92

School of Materials Science and Engineering, University of Science & Technology Beijing, Beijing City, 100083, P.R. China.

Current emission stability is one of the key issues for field emitters for them to be practically applied as electron sources. In the present work, large-scale and well-aligned B-doped SiC nanoneedle arrays have been grown on 6H-SiC wafer substrates via pyrolysis of polymeric precursors. The measured field emission (FE) characteristics suggest that the turn-on fields of the as-synthesized SiC nanoneedle arrays are reduced from 1.92 to 0.98 V μm(-1) with temperature increasing from room temperature (RT) to 500 °C, suggesting their excellent FE performances. The slightly changed current fluctuations (only ∼1.3%) between RT and 200 °C confirm that the present SiC nanoarrays with B dopants could be highly stable field emitters to be used in service under harsh conditions of high temperatures.
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http://dx.doi.org/10.1039/c5nr00952aDOI Listing
May 2015

Long-lived and well-resolved Mn²⁺ ion emissions in CuInS-ZnS quantum dots.

Sci Rep 2014 Dec 17;4:7510. Epub 2014 Dec 17.

Institute of Materials, Ningbo University of Technology, Ningbo 315016, China.

CuInS2 (CIS) quantum dots (QDs) have tunable photoluminescence (PL) behaviors in the visible and near infrared spectral range with markedly lower toxicity than the cadmium-based counterparts, making them very promising applications in light emitting and solar harvesting. However, there still remain material- and fabrication- related obstacles in realizing the high-performance CIS-based QDs with well-resolved Mn(2+) d-d emission, long emission lifetimes as well as high efficiencies. Here, we demonstrate the growth of high-quality Mn(2+)-doped CuInS-ZnS (CIS-ZnS) QDs based on a multi-step hot-injection strategy. The resultant QDs exhibit a well-resolved Mn(2+) d-d emission with a high PL quantum yield (QY) up to 66% and an extremely long excited state lifetime up to ~3.78 ms, which is nearly two times longer than the longest one of "green" QDs ever reported. It is promising that the synthesized Mn(2+)-doped CIS-ZnS QDs might open new doors for their practical applications in bioimaging and opto/electronic devices.
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http://dx.doi.org/10.1038/srep07510DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5378940PMC
December 2014