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PurposeThe purpose of this study is to enhance the comprehensive understanding of the roles of resource investments, explicit contracts and three components ofguanxi(i.e.renqing,ganqingandmianzi) in asymmetric research and development (R&D) partnerships. Treating dependence asymmetry as a multidimensional construct, this study examines the moderating effects of these elements on the relationships between resources and information asymmetry and opportunism.Design/methodology/approachThe study was executed by issuing questionnaires to R&D managers participating in R&D projects and collaborations in the Shanghai and Jiangsu provinces via e-mail and face to face surveys. A multiple regression analysis was used to test the hypotheses.FindingsThe empirical test generally supported the conceptual model and produced the following findings: first, resources and information asymmetry significantly and positively affect opportunism. Second, the partner's resource investments can weaken the effect of resources and information asymmetry on the partner's opportunism. Third, explicit contracts can reduce the impact of information asymmetry on the partner's opportunism. Fourth,renqingandganqingbut notmianzican weaken the influence of information asymmetry on the partner's opportunism.Originality/valueThis study provides a comprehensive and clear understanding of how opportunism can be curbed by jointly considering resource investments, explicit contracts andguanxiin asymmetric R&D cooperative relationships. Moreover, dependence asymmetry andguanxiare measured as a multidimensional construct and reveal their underlying structure, which expands previous understandings of risk management in R&D collaborations.

The exploration of highly efficient catalysts based on nano-sized Ti-rich titanosilicate zeolites with controllable active titanium species is of great importance in zeolite catalytic reactions. Herein, we reported an efficient and facile synthesis of nano-sized Ti-rich TS-1 (MFI) zeolites by replacing tetrabutyl orthotitanate (TBOT) with tetrabutyl orthotitanate tetramer (TBOT-tetramer) as the titanium source. The introduced TBOT-tetramer slowed down the zeolite crystallization process, and accordingly balanced the rate of incorporating Ti and the crystal growth and inhibited the massive formation of anatase species. Notably, the prepared Ti-rich TS-1 zeolite sample had a Si/Ti as low as 27.6 in contrast to conventional one with a molar ratio of 40. The TBOT-tetramer endowed the titanosilicate zeolites with enriched active titanium species and enlarged external surface area. It also impeded the formation of anatase species, resulting in superior catalytic behavior toward the oxidative desulfurization of dibenzothiophene compared with the conventional TS-1 zeolite counterpart prepared with TBOT. ; The authors thank the National Natural Science Foundation of China, China (Grant 21920102005, 21621001, and 21835002), the 111 Project, China (B17020), the European Union through the European Research Council, European Union (grant ERC-AdG-2014-671093, SynCatMatch), and the Spanish Government through "Severo Ochoa", Spain (SEV-2016-0683, MINECO) for supporting this work. R. Bai acknowledges the financial support from China Scholarship Council, China. ; Peer reviewed

Titanosilicate zeolites are catalysts of interest in the field of fine chemicals. However, the generation and accessibility of active sites in titanosilicate materials for catalyzing reactions with large molecules is still a challenge. Herein, we prepared titanosilicate zeolite precursors with open zeolitic structures, tunable pore sizes, and controllable Si/Ti ratios through a hydrothermal crystallization strategy by using quaternary ammonium templates. A series of quaternary ammonium ions are discovered as effective organic templates. The prepared amorphous titanosilicate zeolites with some zeolite framework structural order have extra-large micropores and abundant octahedrally coordinated isolated Ti species, which lead to a superior catalytic performance in the oxidative desulfurization of dibenzothiophene (DBT) and epoxidation of cyclohexene. It is anticipated that the amorphous prezeolitic titanosilicates will benefit the catalytic conversion of bulky molecules in a wide range of reaction processes. ; The authors thank the National Key Research and Development Program of China (Grant 2016YFB0701100), the National Natural Science Foundation of China (Grant 21621001, 21920102005 and 21835002), the 111 Project (B17020), the European Union through the European Research Council (grant ERC-AdG-2014-671093, SynCatMatch), and the Spanish Government through "Severo Ochoa" (SEV-2016-0683, MINECO) for supporting this work. The APS was operated for the U.S. DOE Office of Science by the Argonne National Laboratory, and the CLS@APS facilities (Sector 20) were supported by the U.S. DOE under contract no. DEAC02-06CH11357, and the Canadian Light Source and its funding partners. R. Bai acknowledges the China Scholarship Council for the financial support. ; Peer reviewed

Yue Song,1,* Kaifeng Lin,2,* Shu He,3,* Chunmei Wang,1 Shuaishuai Zhang,1 Donglin Li,1 Jimeng Wang,4 Tianqing Cao,1 Long Bi,1 Guoxian Pei1 1Department of Orthopedics, Xijing Hospital, The Fourth Military Medical University, Xi'an, China; 2Second Department of Orthopedics and Traumatology, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA, Fuzhou, China; 3Department of Orthopedics, Xi'an Hong Hui Hospital, Xi'an, China; 4Department of Orthopedics, The 251st Hospital of Chinese PLA, Zhangjiakou, China *These authors contributed equally to this work Background and aim: As a newly emerging three-dimensional (3D) printing technology, low-temperature robocasting can be used to fabricate geometrically complex ceramic scaffolds at low temperatures. Here, we aimed to fabricate 3D printed ceramic scaffolds composed of nano-biphasic calcium phosphate (BCP), polyvinyl alcohol (PVA), and platelet-rich fibrin (PRF) at a low temperature without the addition of toxic chemicals.Methods: Corresponding nonprinted scaffolds were prepared using a freeze-drying method. Compared with the nonprinted scaffolds, the printed scaffolds had specific shapes and well-connected internal structures.Results: The incorporation of PRF enabled both the sustained release of bioactive factors from the scaffolds and improved biocompatibility and biological activity toward bone marrow-derived mesenchymal stem cells (BMSCs) in vitro. Additionally, the printed BCP/PVA/PRF scaffolds promoted significantly better BMSC adhesion, proliferation, and osteogenic differentiation in vitro than the printed BCP/PVA scaffolds. In vivo, the printed BCP/PVA/PRF scaffolds induced a greater extent of appropriate bone formation than the printed BCP/PVA scaffolds and nonprinted scaffolds in a critical-size segmental bone defect model in rabbits.Conclusion: These experiments indicate that low-temperature robocasting could potentially be used to fabricate 3D printed BCP/PVA/PRF scaffolds with desired shapes and internal structures and incorporated bioactive factors to enhance the repair of segmental bone defects. Keywords: three-dimensional printing, nano-biphasic calcium phosphate, polyvinyl alcohol, platelet-rich fibrin, bone substitutes, tissue engineering