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Open access

Junying Zhang, Qingyang Liu, Yuanju Ding and Yiling Bei

3-aminopropyltriethoxysilane functionalized nanoscale zero-valent iron for the removal of dyes from aqueous solution

Batch studies were conducted to investigate the potential of 3-aminopropyltriethoxysilane modified nano zero-valent iron (APS-NZVI) to adsorb two dyes (acid brilliant scarlet GR and reactive brilliant red K-2BP) from aqueous solution. APS-NZVI showed good adsorption performance for two dyes. Under the adsorption conditions of pH 4.5, initial concentration was 100 mg/L, and time=4h, the maximum adsorption capacities of APS-NZVI were 121.06 mg/g for acid brilliant scarlet GR and 191.5 mg/g for reactive brilliant red K-2BP, respectively. The results revealed that the adsorption behavior of the dyes on the nano-particles fitted well with the Langmuir model and the sorption kinetics fits well the pseudo-second-order rate equation.

Open access

Zhang Ji-wang, Zhang Lai-bin, Ding Ke-Qin and Duan Li-xiang

Abstract

High-speed blades form core mechanical components in turbomachines. Research concerning online monitoring of operating states of such blades has drawn increased attention in recent years. To this end, various methods have been devised, of which, the blade tip-timing (BTT) technique is considered the most promising. However, the traditional BTT method is only suitable for constant-speed operations. But in practice, the rotational speed of turbomachine blades is constantly changing under the influence of external factors, which lead to unacceptable errors in measurement. To tackle this problem, a new BTT method based on multi-phases is proposed. A plurality of phases was arranged as evenly as possible on the rotating shaft to determine the rotation speed. Meanwhile, the corresponding virtual reference point was determined in accordance with the number of blades between consecutive phases. Based on these reference points, equations to measure displacement due to blade vibrations were deduced. Finally, mathematical modeling, numerical simulation and experimental tests were performed to verify the validity of the proposed method. Results demonstrate that the error in measurement induced when using the proposed method is less than 1.8 %, which is much lower compared to traditional methods utilized under variable-speed operation.

Open access

Wenjuan Ding, Huayong Zhang, Fangjuan Zhang, Lijun Wang and Songbo Cui

Abstract

Water level fluctuation and inorganic nitrogen enrichment are two serious problems caused by anthropogenic disturbances in aquatic ecosystems. They cause resource fluctuation and thus might influence the invasive-ness of alien plants. Alternanthera philoxeroides is an amphibious and widespread clonal plant which exhibits significant invasiveness. This experimental study examined the plant's morphological traits under different nitrogen concentrations and water levels. The responses of A. philoxeroides to water levels and nitrogen concentrations were similar for both land-like and riverbank-like initial conditions. A. philoxeroides showed an escape strategy of shoot elongation when its growth was suppressed by shallow submergence. No toxic symptoms but increased clonal spread was observed at high nitrogen concentrations, suggesting that A. philoxeroides not only tolerated but benefitted from nitrogen-polluted water. High nitrogen level mitigated the negative effects of submergence on its leaf survival, thereby enhancing its adaptation to water level fluctuation. Such strong adaptability and clonal spread helps A. philoxeroides to grow and invade successfully in shallow eutrophic water.

Open access

Maha El Fattah, Gang Ding, Fulan Wei, Chunmei Zhang, Eman Ezz and Songlin Wang

Identification and Cementoblastic / Osteoblastic Differentiation of Postnatal Stem Cells from Human Periodontal Ligament

Background. Periodontal diseases that lead to the destruction of periodontal tissues, including periodontal ligament (PDL), cementum, and bone, are a major cause of tooth loss in adults and are a substantial public health burden worldwide. PDL is a specialized connective tissue that connects cementum and alveolar bone to maintain and support teeth in situ and preserve tissue homoeostasis. In this study we aimed to isolate, identify periodontal ligament stem cells and their osteoblastic/cementoblastic differentiation.

Methods. Periodontal ligament tissue was obtained from human impacted third molars (n=5) from different individuals from the oral surgery department, Department of Oral and Maxillofacial Surgery, Capital Medical University School of Stomatology (Beijing, China) following which a colony forming unit - fibroblast assay, identification of periodontal ligament stem cells (PDLSCs; STRO-1 + & CD146+) by using immunocytofluorescence and isolation of PDLSCs (STRO-1+) by using flow cytometry and cementoblastic/osteoblastic exvivo induction were performed.

Results. Mesenchymal stem cells were identified in the periodontal ligament derived by their capacity to form adherent clonogenic cell clusters. Ex-vivo expanded periodontal ligament stem cells were found to express the mesenchymal stem cell markers STRO-1 and CD146. Flow cytometric study showed that a total of 24.53% of periodontal ligament cell population stained positive for the STRO-1 antibody and of that population 1.14% were strongly positive.

Conclusions. The finding of this study indicated that some PDL cells possess crucial stem cells properties, such as self renewal and express the mesenchymal stem cell markers (STRO-1 and CD 146) on their cell surface and small round alizarin red-positive nodules formed in the PDLSC cultures after 4 weeks of induction, indicating calcium accumulation in vitro. Thus, PDL cells can be used for periodontal regenerative procedures.

Open access

Bo Jiang, Chengyun Ding, Guoen Yao, Cunshan Yao, Yunyan Zhang, Junling Ge and Enchao Qiu

Summary

Background: Hyperhomocysteinemia (HHcy) may be corre- lated with cognitive function. Although intervention with folic acid and VitB12 can decrease the homocysteine (Hey) level, its effect on cognitive function remains uncertain. This prospective study aimed to explore the effects of folic acid and VitB/!2 on the ^су an<^ cognitive function in patients with vascular cognitive impairment-no dementia (VCIND) complicated with HHcy.

Methods: A total of 120 patients with VCIND complicated fcy HHcy were randomly selected. They were divided into inter- vention and control groups. The intervention group was given 5 mg of folic acid per day and 500 цд of VitB^ thrice per day apart from conventional therapy. Folic acid, V'itBl2, and Hey were determined and Montreal cognitive assess- ment (MoCA) and event-related potential P300 determination were performed before and after treatment.

Results: Before treatment, no significant differences in the folic acid, VitB^, Hey, MoCA, and P300 parameters were observed between the groups. After treatment, the folic acid and VitBl2 levels increased and the Hey level decreased in the intervention group compared with that before treatment and in the control group. At 24 weeks, the MoCA score and P300 outcomes in the intervention group improved com- pared with those before treatment and in the control group.

Conclusions: Folic acid and VitB^ effectively decrease the Hey level in VCIND patients and improve their cognitive functions.

Open access

Ding Zhu, Chao Zhang, Huahao Shen and Songmin Ying

Open access

Chongjian Fu, Xuelei Huang, Liang Zhang, Bingbing Yu, Gang Sun, Wenwen Li, Juan Ding and Rongfa Bu

Abstract

Background: Mandibular movements are reliable indicators of mandibular system disease and changes in movements can be useful to estimate treatment effect. Detection of mandibular movement is important.

Objectives: We evaluated four-dimensional (4D) visualization of mandibular and temporomandibular joint movement using 320-row computed tomography (CT).

Methods: A stepwise mouth gag was placed between mandibular and maxillary incisors to control mouth opening (0.5-cm increments) in healthy volunteers and one temporomandibular disorder (TMD) patient. A 320-row CT Joint-Move and Shot sequence was used for scanning with an image taken after each increment. 4D reconstruction was used to establish volume data.

Results: 4D visualization of joint and dentition in a rest state and in a state of mandibular movement from multiple angles and in different planes demonstrated differences between healthy subjects and the subject with TMD. The effective dose per scan was approximately 17% of the 16-slice spiral CT.

Conclusion: 4D visualization of mandibular movement can be achieved through 320-row volume CT, which may provide a diagnosis of temporomandibular joint disorder and assessment of treatment effects.

Open access

Jinping Zhang, Zhihong Ding and Jinjun You

Abstract

River runoff and sediment transport are two related random hydrologic variables. The traditional statistical analysis method usually requires those two variables to be linearly correlated, and also have an identical marginal distribution. Therefore, it is difficult to know exactly the characteristics of the runoff and sediment in reality. For this reason, copulas are applied to construct the joint probability distribution of runoff and sediment in this article. The risk of synchronous-asynchronous encounter probability of annual rich-poor runoff and sediment is also studied. At last, the characteristics of annual runoff and sediment with multi-time scales in its joint probability distribution space are simulated by empirical mode decomposition method. The results show that the copula function can simulate the joint probability distribution of runoff and sediment of Huaxia hydrological station in Weihe River well, and that such joint probability distribution has very complex change characteristics at time scales.

Open access

Yiming Zhao, Baitong Chen, Jin Zhang, Ying Ding, Jin Mao and Lihong Zhou

Abstract

This study investigates the evolution of diabetics’ concerns based on the analysis of terms in the Diabetes category logs on the Yahoo! Answers website. Two sets of question-and-answer (Q&A) log data were collected: one from December 2, 2005 to December 1, 2006; the other from April 1, 2013 to March 31, 2014. Network analysis and a t-test were performed to analyze the differences in diabetics’ concerns between these two data sets. Community detection and topic evolution were used to reveal detailed changes in diabetics’ concerns in the examined period. Increases in average node degree and graph density imply that the vocabulary size that diabetics use to post questions decreases while the scope of questions has become more focused. The networks of key terms in the Q&A log data of 2005–2006 and 2013–2014 are significantly different according to the t-test analysis of the degree centrality and betweenness centrality. Specifically, there is a shift in diabetics’ focus in that they have become more concerned about daily life and other nonmedical issues, including diet, food, and nutrients. The recent changes and the evolution paths of diabetics’ concerns were visualized using an alluvial diagram. The food- and diet-related terms have become prominent, as deduced from the visualization results.

Open access

Hu Jiyong, Zhang Xiaofeng, Li Guohao, Yang Xudong and Ding Xin

Abstract

Body motion signals indicate several pathological features of the human body, and a wearable human motion monitoring system can respond to human joint motion signal in real time, thereby enabling the prevention and treatment of some diseases. Because conductive fabrics can be well integrated with the garment, they are ideal as a sensing element of wearable human motion monitoring systems. This study prepared polypyrrole conductive fabric by in situ polymerization, and the anisotropic property of the conductive fabric resistance, resistance–strain relationship, and the relationship between resistance and the human knee and elbow movements are discussed preliminarily.