Journal of Polymer Research最新文献

{"title":"Preparation and biocompatibility of collagen surface-modified styrene-isobutylene-styrene","authors":"Minhan Chen,&nbsp;Yushun Jin,&nbsp;Ruofan Liu,&nbsp;Hao Zhang,&nbsp;Yanhong Song,&nbsp;Wei Ding,&nbsp;Jiwei Li,&nbsp;Yibo Wu","doi":"10.1007/s10965-024-04106-0","DOIUrl":"10.1007/s10965-024-04106-0","url":null,"abstract":"<div><p>Styrene-Isobutylene-Styrene (SIBS) is a high-performance biocompatible elastomeric material. However, its low surface energy and hydrophobic nature limit its widespread application in the field of implantable materials within the human body. In this study, UV-initiated polymerization was employed to prepare SIBS-acrylic acid surface-grafted co-polymer. Subsequently, collagen protein (Coll) surface modification of SIBS was achieved through a coupling reaction with acrylic acid, resulting in the production of Collagen Surface-Modified SIBS, denoted as SIBS-AA-Coll. Characterization was carried out using techniques such as infrared spectroscopy, thermal analysis, scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and water contact angle measurements. The results demonstrated that, with a UV exposure time of 4 min and a n_BP:n_AA ratio of 15:100, the grafting ratio reached 9.4%, significantly improving the hydrophilicity of the SIBS surface. In vitro cytotoxicity tests and in vivo animal implantation experiments indicated that Collagen Surface-Modified SIBS exhibited excellent biocompatibility.</p></div>","PeriodicalId":658,"journal":{"name":"Journal of Polymer Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of effective antibacterial composites of low-density polyethylene modified with quaternary ammonium functionalized zinc oxide nanoparticles","authors":"Sipei Zhao,&nbsp;Changlu Zhou,&nbsp;Rui Zan,&nbsp;Mengxuan Shu,&nbsp;Tao Suo,&nbsp;Zhong Xin","doi":"10.1007/s10965-024-04107-z","DOIUrl":"10.1007/s10965-024-04107-z","url":null,"abstract":"<div><p>The antibacterial activity of biomedical polymer materials is an important basis for their resistance to biofilm contamination as implantable medical devices. However, developing durable and stable antibacterial composites through a universal manufacturing method remains a challenge. Herein, based on an organic–inorganic synergistic antibacterial strategy, functional nanoparticles with high antibacterial performance and better polymer compatibility were prepared by combining zinc oxide nanoparticles (ZnO NPs) with quaternary ammonium compound 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (QAS), which containing siloxane group. The ZnO-QAS nanoparticles were then introduced to low-density polyethylene (LDPE) by simple melt blending to manufacture synergistic antibacterial composites. The organic–inorganic hybrid strategy significantly improved the antibacterial activity of the composites, the PE/ZnO-QAS composites possess satisfactory antibacterial efficiency of 99.9% and 99.75% against <i>Escherichia coli</i> (<i>E. coli</i>) and <i>Staphylococcus aureus</i> (<i>S. aureus</i>), respectively, and it could effectively inhibit biofilms. In addition, the functionalization of organic compound QAS provides excellent polymer compatibility for ZnO NPs, which is conducive to their uniform dispersion in LDPE, and comprehensively improves the thermal stability, mechanical properties, and crystallinity of the composites. This provides potential application value for the preparation of long-term stable antibacterial biomedical materials.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":658,"journal":{"name":"Journal of Polymer Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of the interaction of nitric oxide/nitrogen dioxide with the polymer surfaces in ECMO devices","authors":"Moritz Köglmaier,&nbsp;Thilo Joost,&nbsp;Matthias Kronseder,&nbsp;Werner Kunz","doi":"10.1007/s10965-024-04109-x","DOIUrl":"10.1007/s10965-024-04109-x","url":null,"abstract":"<div><p>In this work, the interactions between nitric oxide (NO)/nitrogen dioxide (NO₂) and the polymer materials of a gas exchanger system used in an extracorporeal membrane oxygenation (ECMO) setting are characterized. FTIR-ATR, XPS, and SEM were used to analyze the effects of the gas treatment. The polymer materials used in the gas exchanger system consisted of polymethylpentene (PMP) hollow fiber membranes, inlet/outlet caps made of methyl methacrylate acrylonitrile butadiene styrene (MABS), casting material consisting of polyurethane (PU), and the gas hoses made of polyvinyl chloride (PVC). Gas treatment with NO and NO₂ was conducted, with exposure times ranging from 30 min to 10 days. The gas concentrations range from 80 to 1000 ppm in the case of NO₂ and a maximum of 10,000 ppm in the case of NO. The formation of nitro and nitrate ester groups and nitric acid (HNO3) adsorption on the polymers’ surface was observed using FTIR-ATR and XPS. The investigations showed that these effects depend on exposure time and gas concentration. The alterations persisted over more extended periods. The XPS measurements showed that the reaction only occurred exclusively on the surface of the polymers. The recorded SEM images showed no macroscopic changes in the surface structures of the polymers.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":658,"journal":{"name":"Journal of Polymer Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polypropylene matrix embedded with Curaua fiber through hot compression processing: characteristics study","authors":"Ajay Sharma,&nbsp;R. Venkatesh,&nbsp;Rishabh Chaturvedi,&nbsp;Rakesh Kumar,&nbsp;Pradeep Kumar Khatokar Vivekananda,&nbsp;Vinayagam Mohanavel,&nbsp;Manzoore Elahi Mohammad Soudagar,&nbsp;Sami Al Obaid,&nbsp;Saleh Hussein Salmen","doi":"10.1007/s10965-024-04108-y","DOIUrl":"10.1007/s10965-024-04108-y","url":null,"abstract":"<div><p>The conventional method made polymer matrix composites found voids, inconsistency, and limited production reasons advanced fabrication techniques are referred to for polymer composite production. With the benefits of complex shape production, the hot compression moulding process is suitable for polymer composite fabrication, and thermo-plastic polymer grade polypropylene (PP) is the source of automotive components, including door panels, bumpers, and interior trim reasons. The PP based composites are fabricated with alkali-treated Curaua fiber (ACF) as 0, 6, 12, and 18 percentage of its weight (wt%) through hot compression method followed by 100 MPa compression pressure. The fabricated polypropylene composites like PP, PP/6% ACF, PP/12% ACF, and PP/18% ACF characteristics such as microstructure, interfacial strength, flexural strength, tensile stress, elongation at break, and fracture toughness are investigated. The effect of ACF fiber blend and compression processing on the behaviour of composites are compared. Microstructural studies revealed that the ACF is effectively dispersed in the PP matrix influences better composite behaviour, and the composite sample of PP/18% of ACF exploited superior interfacial strength, flexural strength, tensile stress, elongation at break, and fracture toughness, which values are 9.8 ± 0.1 MPa, 79 ± 1 MPa, 67 ± 2 MPa, 136 ± 2%, and 1.48 MPam^0.5. It is more than the characteristics of PP prepared without ACF. However, the hot compression processing for PP and ACF found better enhancement in interfacial strength.</p></div>","PeriodicalId":658,"journal":{"name":"Journal of Polymer Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modification on PBS using epoxy-functionalized core–shell starch particles","authors":"Q. Liu,&nbsp;L. Ren,&nbsp;X. Y. Li,&nbsp;X. Y. Sui,&nbsp;Y. D. Shen,&nbsp;Y. B. Wang,&nbsp;Y. Q. Li,&nbsp;M. Y. Zhang","doi":"10.1007/s10965-024-04111-3","DOIUrl":"10.1007/s10965-024-04111-3","url":null,"abstract":"<div><p>Polybutylene succinate (PBS) is an aliphatic linear polyester that is known for its excellent biodegradability and biocompatibility, making it one of the most promising application polymers. However, its disadvantages of poor toughness, low thermostability, and high crystallinity limit its large-scale commercial applications. In this article, a novel epoxy-functionalized core–shell starch particle (CSP-GMA) is successfully synthesized by virtue of soap-free emulsion polymerization, which consists of a \"hard\" starch (St) core and a \"soft\" ethyl acrylate (EA) shell grafted with glycidyl methacrylate (GMA). A binary blend of biodegradable polymers is prepared via a melt blend process with CSP-GMA as a core–shell particle modifier and PBS as a polymer matrix. The mechanical properties, thermal behavior, crystallization properties, stability and microscopic morphology of PBS/CSP-GMA blends are thoroughly studied. The incorporation of 20 wt% CSP-GMA into the PBS blend promotes an increase in the impact strength by 55% and the elongation at break by 173% higher than that of pure PBS respectively, which indicates that our work proposes an efficient strategy for fabricating PBS blends with good comprehensive properties and low cost. The DSC testing shows that the crystallinity of PBS blend is reduced in comparison to PBS, while the crystallization temperature is also decreased, confirming that CSP-GMA can facilitate the crystallization of PBS. The SEM observation reveals that owing to the compatibility arising between two phases interface due to the presence of epoxy group on core–shell starch particle surface, CSP-GMA is better dispersed in the PBS matrix, resulting in the improvement for performance of PBS blends.</p></div>","PeriodicalId":658,"journal":{"name":"Journal of Polymer Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10965-024-04111-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Basalt powder based thermoset and thermoplastic composites for lightweight applications","authors":"Praveenkumara Jagadeesh,&nbsp;Sanjay Mavinkere Rangappa,&nbsp;Vincenzo Fiore,&nbsp;Hom Nath Dhakal,&nbsp;Suchart Siengchin","doi":"10.1007/s10965-024-04103-3","DOIUrl":"10.1007/s10965-024-04103-3","url":null,"abstract":"<div><p>The continuous raise of environmental issues by the polymer products has led to the use of eco-friendly basalt as a reinforcement for the composites fabrication. Basalt reinforcement has attractive qualities such as non-toxicity, ease of processing steps, economical, less harmful, and excellent thermal, and mechanical properties. Basalt loading into different polymer matrices is indeed a comparably novel concept that may offer some very intriguing views, which have not yet been fully explored. The ability of mineral fillers such as basalt powder to reduce the polymer portion in polymer goods by retaining their original characteristics hand out to the establishment of a pollution-free ecosystem and the stabilizing of ecological issues. In this context, the current research aims to manufacture and characterize thermoset (i.e., synthetic epoxy, bio-epoxy, unsaturated polyester, and vinyl ester) and thermoplastic (i.e., polylactic acid, bio-based polypropylene, and bio-based high density polyethylene) composites reinforced with the same weight content (i.e., 30%) of basalt powder. These composites were employed for physical, mechanical, wettability (contact angle analysis), morphological, and water absorption investigations. Moreover, basalt powder was subjected to elemental analysis (Energy dispersive X-ray), particle dimensional analysis, and morphological (Scanning Electron Microscopy) observations. The experimental results revealed that the tensile, flexural, and impact strength characteristics of composites were slightly reduced in comparison to neat polymers because of higher reinforcement. Besides, the tensile modulus, flexural modulus, and hardness values were gradually improved due to the filler effect. The increased water absorption is mainly caused by the voids inside of the composites, which create the quintessential environment for moisture to seep into the interface. Differential scanning calorimetry analysis reveals that the filler has successfully maintained the chain relaxation with the reduction of molecular movement and achieved stability as equivalent to a 100% polymer system, despite the incorporation of basalt by reducing the 30 wt% polymers. Except for synthetic epoxy composite, the remaining polymer composites have shown enhanced thermal conductivity values than neat polymers. However, the obtained findings can be considered satisfactory for prospective applications concerning lightness and environmental friendliness.</p></div>","PeriodicalId":658,"journal":{"name":"Journal of Polymer Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication of thermosensitive palladium imprinted polymers and evaluation of their adsorption separating performances and practical applications","authors":"Wan Xu,&nbsp;Huijuan Zhang,&nbsp;Ting Huo,&nbsp;Yongsheng Xiang,&nbsp;Xiaojian Ou,&nbsp;Yuan Sun,&nbsp;Yuanjun Sun,&nbsp;Zhenbin Chen","doi":"10.1007/s10965-024-04104-2","DOIUrl":"10.1007/s10965-024-04104-2","url":null,"abstract":"<div><p>The excellent physical and chemical properties of palladium(Pd) have made its application and demand increase gradually. Therefore, it is important to develop a new material to efficiently separate and purify palladium from secondary sources to ensure its supply. In this work, a thermosensitive palladium smart imprinted polymer(Pd-T-SIP) was synthesized, which could achieve the efficient separation and purification of Pd. The microstructure and morphology of Pd-T-SIP were characterized. The experimental results showed that the Pd-T-SIP showed the maximum adsorption amount(<i>Q</i>) of 0.1022 mmol/g for Pd(IV), the desorption rate(<i>D</i>) was 83.09%, and it had good reusability. Theoretical studies showed that the adsorption process of Pd-T-SIP was suitable to be described by quasi-first-order model and Langmuir model, which indicated that the adsorption of Pd-T-SIP was monolayer adsorption. Finally, Pd-T-SIP was applied to the platinum group catalyst leach solution, and it could be found that its adsorption/desorption effect was more excellent, with its adsorption amount reaching 0.1558 mmol/L, desorption rate reaching 77.14%, and the palladium purity after one adsorption/desorption cycle increased from 13.75% to 30.62%, and the purity of platinum group metals increased from 40.29% to 73.56% after one adsorption/desorption cycle.</p></div>","PeriodicalId":658,"journal":{"name":"Journal of Polymer Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiple layered PVDF-CNTs foams with gradient structure and high electromagnetic shielding performance","authors":"Yongbo Si,&nbsp;Kun Li,&nbsp;Zihao Ding,&nbsp;Shixun Zhang,&nbsp;Xiaoli Zhang,&nbsp;Xia Liao,&nbsp;Yang Yang,&nbsp;Xiaoqin Guo,&nbsp;Jingbo Chen","doi":"10.1007/s10965-024-04102-4","DOIUrl":"10.1007/s10965-024-04102-4","url":null,"abstract":"<div><p>Multiple layered PVDF-CNTs with different CNTs were prepared by facile melt blending process. Due to varied electrical conductivity in each layer, incident electromagnetic (EM) waves could be reflected and absorbed between these layers, and thus their electromagnetic interference (EMI) efficiency was obviously improved. EMI shielding effectiveness of a three- layered PVDF-CNTs with CNTs content of 6, 8, 10 wt. % sequentially, is 36.4 dB, compared to a 27.2 dB of single layered PVDF-8CNTs with a same sample thickness of 2 mm, an increase of 34% was induced. Furthermore, based on different viscoelasticity of PVDF-CNTs with various CNTs content, three- layered PVDF-6–8-10 CNTs foams with a gradient cell structure and thickness of 2 mm, were manufactured by an environment friendly supercritical CO₂ batch foaming method, an absolute EM SE value of 35.2 dB at a frequency of 26 GHz was measured. Because of the introduction of microcellular sized cells, the electromagnetic waves were absorbed and reflected inside the cells, cooperated with the multiple reflections between different layers, an increased absorption dominated mechanism in these foamed PVDF-CNTs composites was resulted, which means a successful mechanism transformation from reflection to absorption after foaming.</p></div>","PeriodicalId":658,"journal":{"name":"Journal of Polymer Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Silver doped boron nitride approach to improve the thermal conductivity of polyurethane composites","authors":"Shuangshuang Sun,&nbsp;Yang Wu,&nbsp;Yu Zhang,&nbsp;Yue-Ming Sun,&nbsp;Hongtao Lin,&nbsp;Ming Wang,&nbsp;Chuanzeng Wang,&nbsp;Shuhai Chen","doi":"10.1007/s10965-024-04089-y","DOIUrl":"10.1007/s10965-024-04089-y","url":null,"abstract":"<div><p>High thermal conductivity composites have attracted considerable attention due to their extensive applications in electronic devices. In the present work, we propose a novel strategy by employing boron nitride doped silver nanoparticles (BN-Ag) to improve the thermal conductivity of polyurethane composites. The BN-Ag composite was prepared by depositing silver nanoparticles (AgNPs) onto the surface of boron nitride (BN), facilitating cross-linking between adjacent BN sheets. Interestingly, despite the low concentration of AgNPs at just 2.5% (The proportion is determined by the quantity of BN, and the subsequent statement remains unchanged), their thermal conductivity of BN-Ag/PU is significant enhanced by approximately 184%, while maintaining excellent thermal stability and high resistivity. Meanwhile, to further augment the thermal conductivity, a more noticeable improvement up to 236% without compromising its superior insulation properties (5.03 × 10¹³ Ω · cm) was recorded by doping BN-Ag/PU with silver nanowires (BN-Ag@AgNP/PU).</p></div>","PeriodicalId":658,"journal":{"name":"Journal of Polymer Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel eco-friendly PVA/Alginate biocomposites containing C.niveum extract: Development, characterization and optical properties","authors":"Sibel Selçuk Pekdemir ,&nbsp;Serpil Yalcin Kuzu,&nbsp;Mustafa Ersin Pekdemir,&nbsp;Pelin Yılmaz Sancar,&nbsp;Mediha Kök","doi":"10.1007/s10965-024-04088-z","DOIUrl":"10.1007/s10965-024-04088-z","url":null,"abstract":"<div><p>This study explores the development of eco-friendly biocomposite films incorporating Poly(vinyl alcohol) (PVA), Alginate, and <i>Cyclotrichium niveum</i> (<i>C. niveum</i>) extract. The research emphasizes the fabrication of PVA/Alginate blend biocomposites produced by solvent casting with varying concentrations of <i>C. niveum</i>, analyzing their physicochemical, biochemical, and optical characteristic features. These biocomposites exhibited enhanced properties making them suitable to for applications such as packaging, and agricultural films. Significant outcomes of the research include the biocomposites improved thermal stability and semiconductor properties, evidenced by the decrease in band gap energy as the concentration of <i>C. niveum</i> increases. This work underscores the crucial role of integrating natural and synthetic polymers to address environmental challenges posed by traditional plastics, steering the field toward sustainable material solutions.</p></div>","PeriodicalId":658,"journal":{"name":"Journal of Polymer Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}