Inference Based on Empirical Likelihood for Varying Coefficient Model with Random Effect

In this article, we develop a statistical inference technique for the unknown coefficient functions in the varying coeffi- cient model with random effect. A residual-adjusted block empirical likelihood (RABEL) method is suggested to inves- tigate the model by taking the within-subject correlation into account. Due to the residual adjustment, the proposed RABEL is asymptotically chi-squared distribution. We illustrate the large sample performance of the proposed method via Monte Carlo simulations and a real data application.

Mechanical compression management of the right middle cerebral artery inferior trunk using a stent during coil embolization of middle cerebral artery aneurysms:A case report and literature review

Endovascular coil embolization is a minimally invasive,rapid,and effective method for the treatment of intracranial aneurysms.However,complications associated with coil embolization,such as intraoperative aneurysm rupture or arterial occlusion,should be promptly managed during the procedure to avoid catastrophic consequences.This study presents a case of mechanical compression management of the right middle cerebral artery(MCA)inferior trunk during coil embolization for bilateral MCA aneurysms.The inferior trunk of the right MCA was abruptly occluded due to mechanical compression during coil embolization of the right MCA bifurcation aneurysm.A Solitaire AB stent(4×20 mm,Covidien/Medtronic,Dublin,Ireland)was implanted in the inferior trunk of the right MCA after tirofiban was injected via a microcatheter,and the right inferior trunk was recanalized.The patient also underwent coil embolization of the left MCA bifurcation aneurysm,without any complications.It is crucial to recognize compressive occlusion of adjacent aneurysm branches to avoid severe complications during intracranial aneurysm embolization.Stent placement is a rescue treatment option for recanalization of an occluded artery.

Efficient Shrinkage Estimation about the Partially Linear Varying Coefficient Model with Random Effect for Longitudinal Data

In this paper, an efficient shrinkage estimation procedure for the partially linear varying coefficient model (PLVC) with random effect is considered. By selecting the significant variable and estimating the nonzero coefficient, the model structure specification is accomplished by introducing a novel penalized estimating equation. Under some mild conditions, the asymptotic properties for the proposed model selection and estimation results, such as the sparsity and oracle property, are established. Some numerical simulation studies and a real data analysis are presented to examine the finite sample performance of the procedure.

A survey of the information needs of visually impaired library users

Purpose:The research aims to investigate the information needs of visually impaired library users in China in order to increase our understanding of these users and help the Chinese public libraries improve their services for them.Design/methodology/approach:A questionnaire survey was used to study the library users’ information needs.Eleven large public libraries in different areas of China,which were pioneers in implementing services for visually impaired people,were chosen to conduct the survey.Data analysis was based on 97 valid questionnaires retrieved.Findings:Radio and television were still the preferred sources of information for visually impaired users.In information seeking,they had a strong preference for obtaining information in the most convenient way,and accessing a vast amount of information,which was updated quickly.They paid more attention to the information closely related to their work and life.Their purposes of seeking information were mainly for learning,relaxation and intercommunication.Visually impaired users felt some barriers in their access to library services such as a lack of time or a sighted companion who can come along for the trip to the library.Moreover,it was difficult for them to use the Internet to search for information,because many websites do not support the auxiliary software designed especially for visually impaired users or the websites offer only a paid subscriber service.Research limitations:A majority of the respondents were young and middle-aged people and engaged in work.The sample size needs to be enlarged,and different groups of users such as old people and students should be included to yield more useful results.Practical implications:The survey results provide insights into the information needs of the Chinese visually impaired library users.Meanwhile,the research can serve as a reference source for the future studies of the service for visually impaired library users.Originality/value:So far,few studies were conducted to investigate the information needs of visually impaired library users in China.

The Influence of the Urban-Rural Income Disparity on the Industrial Structure—Taking the Yangtze River Delta Region as an Example

In this paper, the effect of the mediation effect is mainly used to test and analyze the regression model, and most scholars have studied the impact of the modernization of the industrial structure on the income gap. However, this paper is from another perspective, based on the social background of high-quality development, the main study is the impact mechanism of urban and rural income gap on the industrial structure, taking the Yangtze River Delta as the main research object, and specifically selecting 22 central cities in the Yangtze River Delta region, which is also one of the highlights of this study. The regression model is constructed by using the intermediary effect, and the four intermediary variables of fiscal expenditure (M1), fixed asset investment (M2), number of patent applications (M3), and total import and export (M4) are selected, which represent the role of the government, fixed asset investment, scientific and technological level and opening-up level, and study and analyze the inherent influence mechanism between each variable. Before doing specific research, I consulted the papers and literature of many other outstanding scholars, among which Cheng Yuhong and Cheng Chi’s “The Influence Mechanism of industrial structure of urban and rural income gap” [1] has great reference value for this paper. According to the research results, under the background of high-quality development in the Yangtze River Delta region, the expansion of the income gap between urban and rural areas will inhibit the upgrading of the industrial structure, so it is necessary to focus on building a new type of urbanization, accelerating the construction of an urban innovation system, optimizing the rural employment structure to narrow the income gap between urban and rural areas, and providing impetus for the continuous upgrading of the industrial structure.

Vapor-phase postsynthetic amination of hypercrosslinked polymers for efficient iodine capture

Hypercrosslinked polymers(HCPs)with large surface areas,high intrinsic porosities and low production costs may be available platforms for iodine capture.However,the lack of iodine-philicity binding sites limits their adsorption capacity.Here we use vapor-phase postsynthetic amination strategy to introduce electron-donating amino groups into the prefabricated HCPs for enhancing their iodine capture performance.Through simple vapor-phase exposure,the halogen-containing HCPs can be grafted by amines through nucleophilic substitution toward chloro groups.Combining with the abundant amino groups and high porosities,the amino-functionalized porous polymers show substantially increased iodine adsorption capacity,about 221%as that of original one,accompanied by excellent recyclability.Mechanism investigations reveal the key roles of the electron-donor amino groups andπ-conjugated benzene rings along with structure characteristics of porous polymer frameworks in iodine capture.Moreover,this vapor-phase amination strategy shows good generality and can be extended to various amines,e.g.,ethylenediamine,1,3-diaminopropane and diethylenetriamine.Our work proves that this simple vapor-phase postsynthetic functionalization strategy may be applied in other porous polymers with wide application prospects in adsorption,separation and storage.

南朗河鱼类资源现状调查

2011年12月上旬,对南朗河澜沧县河段进行鱼类资源调查。调查范围北起澜沧县勐朗镇勐滨村,南至惠民乡芒景村,实际调查河段流程约65千米。综合调查实际采集标本鉴定结果和走访当地从业人员,确定澜沧县南朗河调查鱼类24种、虾类1种。南朗河中下游鱼类资源明显比中上游丰富,不仅体现在采捕到鱼的数量和体重方面,鱼的种类也随河流向下游延伸而呈现增多的趋势。鱼类资源现状主要表现为:鱼类资源仍然较丰富,但小型化、低龄化趋势明显,品种结构趋于单一,传统名优鱼类资源量下降显著;资源变动主要原因水域环境污染、过度捕捞。

Highly stable and antifouling graphene oxide membranes prepared by bio-inspired modification for water purification

Graphene oxide(GO)membranes show great potential in molecular separation for water treatment.However,the inferior stability of GO membranes is a major bottleneck for practical applications.In this study,bio-inspired polydopamine(PDA)deposition is reported for enhancing the stability of GO membranes.Through simple and mild immersion,PDA is self-polymerized on GO membranes.The blocking of PDA chains to membrane defects improves the rejections for various molecules.Because the inherently strong adhesion and crosslinking of PDA greatly strengthen the interactions of substrates to GO layers and the binding force of GO nanosheets,the prepared PDA-GO membranes exhibit impressive long-te rm stability in cross-flow filtration,and maintain good nanofiltration perfo rmance at various feed pressures,tangential velocities,and eve n after external scratching.Moreover,because the deposited PDA layers obstruct the direct contact between GO and contaminants,the antifouling property of the PDA-GO membranes increases substantially,with recovery ratio about 98%.

Sub-5 nm porous polymer decoration toward superhydrophobic MOFs with enhanced stability and processability

Metal-organic frameworks(MOFs) show great potential for various applications, but many of them suffer from the drawbacks of hydrolysis propensity and poor processability. Herein, we employ polymers of intrinsic microporosity(PIMs) with hydrophobic pores to decorate MOFs toward substantially improved water stability and shapeability. Through simple PIM-1 decoration, the sub-5 nm polymer layers can be uniformly deposited on MOF surfaces with almost no deterioration in porosity. Owing to the existence of superhydrophobic coating and the obstruction of water entrance into MOFs, the PIM-1 coated Cu BTC exhibits impressive water resistance and excellent pore preservation ability after exposure in water, even in acidic and alkaline solutions. Moreover, polymer decoration improves the processability of MOFs, while various MOF/PIM-1 bulk wafers and oil-water separators can be obtained straightforwardly.

Fast Blood Oxygenation through Hemocompatible Asymmetric Polymer of Intrinsic Microporosity Membranes

Membrane technology has attracted considerable attention for chemical and medical applications,among others.Artificial organs play important roles in medical science.A membrane oxygenator,also known as artificial lung,can replenish O_(2) and remove CO_(2) of blood to maintain the metabolism of patients with cardiopulmonary failure.However,the membrane,a key component,is subjected to inferior gas transport property,leakage propensity,and insufficient hemocompatibility.In this study,we report efficient blood oxygenation by using an asymmetric nanoporous membrane that is fabricated using the classic nonsolvent-induced phase separation method for polymer of intrinsic microporosity-1.The intrinsic superhydrophobic nanopores and asymmetric configuration endow the membrane with water impermeability and gas ultrapermeability,up to 3,500 and 1,100 gas permeation units for CO_(2) and O_(2),respectively.Moreover,the rational hydrophobic–hydrophilic nature,electronegativity,and smoothness of the surface enable the substantially restricted protein adsorption,platelet adhesion and activation,hemolysis,and thrombosis for the membrane.Importantly,during blood oxygenation,the asymmetric nanoporous membrane shows no thrombus formation and plasma leakage and exhibits fast O_(2) and CO_(2) transport processes with exchange rates of 20 to 60 and 100 to 350 ml m^(−2) min^(−1),respectively,which are 2 to 6 times higher than those of conventional membranes.The concepts reported here offer an alternative route to fabricate high-performance membranes and expand the possibilities of nanoporous materials for membrane-based artificial organs.

Effect of Fluorination on the Photovoltaic Properties of Medium Bandgap Polymers for Polymer Solar Cells

Fluorination of conjugated polymers is one of the effective strategies to tune the molecular energy levels and morphology for high efficient polymer solar cells （PSCs）. Herein, two novel donor-acceptor conjugated polymers, PffBT and PBT, based on bis（3,5-bis（hexyloxy）phenyl）benzo[1,2- b：4,5-b＇]dithiophene and benzo[c][1,2,5]thiadiazole （BT） with or without fluorination, respectively, were synthesized, and their photovoltaic properties were compared. The polymer PffBT based on fluorinated BT showed lower frontier energy levels, improved polymer ordering, and a well-developed fibril structure in the blend with PC71BM. As a result, the PSCs based on PffBT/PC71BM exhibit a superior power conversion efficiency （PCE） of 8.6% versus 4.4% for PBT-based devices, due to a high space charge limit current （SCLC） hole mobility, mixed orientation of polymer crystals in the active layer, and low bimolecular recombination.