Inter-organizational governance and trilateral trust building: a case study of crowdsourcing-based open innovation in China

In a case study of a Chinese crowdsourcing intermediary, we explore the impact of inter-organizational governance on trilateral trust-building. We show that formal control and relational governance mechanisms are essential for swift and knowledge-based trust in R&D crowdsourcing. The case also indicates that Chinese businesses continue to use guanxi (informal personal connections) as a relational and contingent mechanism to maintain affect-based trust, but guanxi is shown to inhibit the growth of Internet-based crowdsourcing for open innovation in China

Imaging findings in craniofacial childhood rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the commonest paediatric soft-tissue sarcoma constituting 3–5% of all malignancies in childhood. RMS has a predilection for the head and neck area and tumours in this location account for 40% of all childhood RMS cases. In this review we address the clinical and imaging presentations of craniofacial RMS, discuss the most appropriate imaging techniques, present characteristic imaging features and offer an overview of differential diagnostic considerations. Post-treatment changes will be briefly addressed

Immediate release tablet formulation of varenicline salicylate and comparative pharmacokinetic study in human volunteers

Seong Shin Kwak,1,* Eun Seok Lee,1,* Ho Yub Yoon,1 Chang Hyun Kim,1 Yoon Tae Goo,1 Myung Joo Kang,2 Sangkil Lee,3 Bong Sang Lee,4 Hong Ryeol Jeon,4 Chang Hyun Oh,5 Young Wook Choi1 1College of Pharmacy, Chung-Ang University, Heuksuk-ro, Dongjak-gu, Seoul 06974, Republic of Korea; 2College of Pharmacy, Dankook University, Dandae-ro, Dongnam-gu, CheonanChungnam 31116, Republic of Korea; 3College of Pharmacy, Keimyung University, Dalgubeol-daero, Daegu 42601, Republic of Korea; 4CTCBIO INC., Hyundaikia-ro, Paltan, Hwaseong, Gyeonggi 18576, Republic of Korea; 5Center for Biomaterials, Korea Institute of Science & Technology (KIST), Hwarang-ro, Seongbuk-gu, Seoul 02792, Republic of Korea *These authors contributed equally to this work Purpose: To develop an immediate release-type tablet containing varenicline salicylate (VRC-S), a smoking cessation agent, formulation and stability studies were performed. The in vitro dissolution and in vivo pharmacokinetic (PK) behavior of the tablets were compared with those of the commercial product (Champix) as a reference. Materials and methods: The characteristics of the powder were investigated by particle morphology, size distribution, solubility, hygroscopicity, differential scanning calorimetry, and powder X-ray diffraction. Based on the drug–excipient compatibility test, different VRC-S tablets were prepared with the selected excipients through direct compression or wet granulation method and subjected to a dissolution test. The stability of the most promising VRC-S tablet (F4) was evaluated under accelerated conditions (40°C and 75% relative humidity). Further, the dissolution and human pharmacokinetic profiles of the F4 tablet and Champix were compared. Results: VRC-S showed a positively skewed unimodal size distribution with a specific surface area of 2.02 m2/g, single endothermic peak of 225.2°C in differential scanning calorimetry, crystalline internal structure in powder X-ray diffraction, aqueous solubility of 244.7 mg/mL, and hygroscopicity of 0.256 mg/g. The wet granulation method was preferred for tablet preparation and employed the following excipients: microcrystalline cellulose and anhydrous dibasic calcium phosphate as diluents, croscarmellose sodium as a disintegrant, and colloidal silicon dioxide and magnesium stearate as lubricants. The F4 tablet was stable for 6 months under accelerated conditions. The dissolution of VRC was pH independent, revealing f2 values of 76.49 and 68.38 at pH 1.2 and pH 6.8, respectively. After the oral administration of F4 tablet and Champix to healthy human volunteers, pharmacokinetic parameters, including time to reach the maximum plasma concentration (Tmax), maximum plasma concentration (Cmax), and area under the curve from 0 to infinity (AUCinf), were compared. The values of 90% CI were 0.972–1.035 for Cmax and 0.982–1.075 for AUCinf, which was indicative of the bioequivalence of both products. Conclusion: VRC-S–containing F4 tablet might be a good candidate for smoking cessation treatment. Keywords: varenicline salicylate, smoking cessation, formulation, stability, dissolution, bioavailabilit

Irreversible Inactivation of Glutathione Peroxidase 1 and Reversible Inactivation of Peroxiredoxin II by H2O2 in Red Blood Cells

Catalase, glutathione peroxidase1 (GPx1), and peroxiredoxin (Prx) II are the principal enzymes responsible for peroxide elimination in RBC. We have now evaluated the relative roles of these enzymes by studying inactivation of GPx1 and Prx II in human RBCs. Mass spectrometry revealed that treatment of GPx1 with H2O2 converts the selenocysteine residue at its active site to dehydroalanine (DHA). We developed a blot method for detection of DHA-containing proteins, with which we observed that the amount of DHA-containing GPx1 increases with increasing RBC density, which is correlated with increasing RBC age. Given that the conversion of selenocysteine to DHA is irreversible, the content of DHA-GPx1 in each RBC likely reflects total oxidative stress experienced by the cell during its lifetime. Prx II is inactivated by occasional hyperoxidation of its catalytic cysteine to cysteine sulfinic acid during catalysis. We believe that the activity of sulfiredoxin in RBCs is sufficient to counteract the hyperoxidation of Prx II that occurs in the presence of the basal level of H2O2 flux resulting from hemoglobin autoxidation. If the H2O2 flux is increased above the basal level, however, the sulfinic Prx II begins to accumulate. In the presence of an increased H2O2 flux, inhibition of catalase accelerated the accumulation of sulfinic Prx II, indicative of the protective role of catalase. Antioxid. Redox Signal. 12, 1235–1246