Managing business and innovation networks — From strategic nets to business fields and ecosystems

This article introduces the Special Issue of Managing Business and Innovation Networks and makes an independent contribution to the advancement of network management research. The study has three ambitious goals. First, it evaluates the main developments in network management research from 2000 to 2016, focusing on disciplinary openings. Second, it specifies the contributions of recent domain extensions (business fields, ecosystems, platform networks) to network management, and clarifies the role of networks and network management in these domains. Third, it proposes a general theory of network management based on the past 20 years of research in the field and the contributions of SI articles. The theory explains how the factors at three contextual levels – environment, network and actor – influence network management activities, forming patterns of management based on activity configurations. The framework consolidates our fragmented knowledge on network management and paves the way for more advanced research and management. We conclude with suggestions for future research.</p

Association between recurrent fracture risk and implementation of fracture liaison services in four Swedish hospitals: A cohort study

Structured secondary preventions programs, called fracture liaison services (FLSs), increase the rate of evaluation with bone densitometry and use of osteoporosis medication after fracture. However, the evidence regarding the effect on the risk of recurrent fracture is insufficient. The aim of this study was to investigate if implementation of FLS was associated with reduced risk of recurrent fractures. In this retrospective cohort study, electronic health records during 2012 to 2017 were used to identify a total of 21,083 patients from four hospitals in Western Sweden, two with FLS (n = 15,449) and two without (n = 5634). All patients aged 50 years or older (mean age 73.9 [SD 12.4] years, 76% women) with a major osteoporotic index fracture (hip, clinical spine, humerus, radius, and pelvis) were included. The primary outcome was recurrent major osteoporotic fracture. All patients with an index fracture during the FLS period (n = 13,946) were compared with all patients in the period before FLS implementation (n = 7137) in an intention‐to‐treat analysis. Time periods corresponding to the FLS hospitals were used for the non‐FLS hospitals. In the hospitals with FLSs, there were 1247 recurrent fractures during a median follow‐up time of 2.2 years (range 0–6 years). In an unadjusted Cox model, the risk of recurrent fracture was 18% lower in the FLS period compared with the control period (hazard ratio = 0.82, 95% confidence interval [CI] 0.73–0.92, p = .001), corresponding to a 3‐year number needed to screen of 61, and did not change after adjustment for clinical risk factors. In the hospitals without FLSs, no change in recurrent fracture rate was observed. Treatment decisions were made according to the Swedish treatment guidelines. In conclusion, implementation of FLS was associated with a reduced risk of recurrent fracture, indicating that FLSs should be included routinely at hospitals treating fracture patients. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research

Thermalized Epoxide Formation in the Atmosphere

Epoxide formation was established a decade ago as a possible reaction pathway for beta-hydroperoxy alkyl radicals in the atmosphere. This epoxide-forming pathway required excess energy to compete with O-2 addition, as the thermal reaction rate coefficient is many orders of magnitude too slow. However, recently, a thermal epoxide forming reaction was discovered in the ISOPOOH + OH oxidation pathway. Here, we computationally investigate the effect of substituents on the epoxide formation rate coefficient of a series of substituted beta-hydroperoxy alkyl radicals. We find that the thermal reaction is likely to be competitive with O-2 addition when the alkyl radical carbon has a OH group, which is able to form a hydrogen bond to a substituent on the other carbon atom in the epoxide ring being formed. Reactants fulfilling these requirements can be formed in the OH-initiated oxidation of many biogenic hydrocarbons. Further, we find that beta-OOR alkyl radicals react similarly to beta-OOH alkyl radicals, making epoxide formation a possible decomposition pathway in the oxidation of ROOR peroxides. GEOS-Chem modeling shows that the total annual production of isoprene dihydroxy hydroperoxy epoxide is 23 Tg, making it by far the most abundant C-5-tetrafunctional species from isoprene oxidation.Peer reviewe

Kinetics of gene expression and bone remodelling in the clinical phase of collagen-induced arthritis

INTRODUCTION: Pathological bone changes differ considerably between inflammatory arthritic diseases and most studies have focused on bone erosion. Collagen-induced arthritis (CIA) is a model for rheumatoid arthritis, which, in addition to bone erosion, demonstrates bone formation at the time of clinical manifestations. The objective of this study was to use this model to characterise the histological and molecular changes in bone remodelling, and relate these to the clinical disease development. METHODS: A histological and gene expression profiling time-course study on bone remodelling in CIA was linked to onset of clinical symptoms. Global gene expression was studied with a gene chip array system. RESULTS: The main histopathological changes in bone structure and inflammation occurred during the first two weeks following the onset of clinical symptoms in the joint. Hereafter, the inflammation declined and remodelling of formed bone dominated. Global gene expression profiling showed simultaneous upregulation of genes related to bone changes and inflammation in week 0 to 2 after onset of clinical disease. Furthermore, we observed time-dependent expression of genes involved in early and late osteoblast differentiation and function, which mirrored the histopathological bone changes. The differentially expressed genes belong to the bone morphogenetic pathway (BMP) and, in addition, include the osteoblast markers integrin-binding sialoprotein (Ibsp), bone gamma-carboxyglutamate protein (Bglap1), and secreted phosphoprotein 1 (Spp1). Pregnancy-associated protein A (Pappa) and periostin (Postn), differentially expressed in the early disease phase, are proposed to participate in bone formation, and we suggest that they play a role in early bone formation in the CIA model. Comparison to human genome-wide association studies (GWAS) revealed differential expression of several genes associated with human arthritis. CONCLUSIONS: In the CIA model, bone formation in the joint starts shortly after onset of clinical symptoms, which results in bony fusion within one to two weeks. This makes it a candidate model for investigating the relationship between inflammation and bone formation in inflammatory arthritis. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13075-015-0531-7) contains supplementary material, which is available to authorized users

Formation of Highly Oxidized Molecules from NO3 Radical Initiated Oxidation of Delta-3-Carene : A Mechanistic Study

NO3 radical oxidation of most monoterpenes is a significant source of secondary organic aerosol (SOA) in many regions influenced by both biogenic and anthropogenic emissions, but there are very few published mechanistic studies of NO3 chemistry beyond simple first generation products. Here, we present a computationally derived mechanism detailing the unimolecular pathways available to the second generation of peroxy radicals following NO3 oxidation of Delta-3-carene, defining generations based on the sequence of peroxy radicals formed rather than number of oxidant attacks. We assess five different types of unimolecular reactions, including peroxy and alkoxy radical (RO2 and RO) hydrogen shifts, RO2 and RO ring closing (e.g., endoperoxide formation), and RO decomposition. Rate constants calculated using quantum chemical methods indicate that this chemical system has significant contribution from both bimolecular and unimolecular pathways. The dominant unimolecular reactions are endoperoxide formation, RO H-shifts, and RO decomposition. However, the complexity of the overall reaction is tempered as only 1 or 2 radical propagation pathways dominate the fate of each radical intermediate. Chemical ionization mass spectrometry (CIMS) measurements using the NO3- reagent ion during Delta-3-carene + NO3 chamber experiments show products consistent with each of the three types of unimolecular reactions predicted to be important from the computational mechanism. Moreover, the SIMPOL group contribution method for predicting vapor pressures suggests that a majority of the closed-shell products inferred from these unimolecular reactions are likely to have low enough vapor pressure to be able to contribute to SOA formation.Peer reviewe

Organ Support Therapy in the Intensive Care Unit and Return to Work in Out-of-Hospital Cardiac Arrest Survivors:a Nationwide Cohort Study

AIM: With increased survival after out-of-hospital cardiac arrest (OHCA), impact of the post-resuscitation course has become important. Among 30-day OHCA survivors, we investigated associations between organ support therapy in the Intensive Care Unit (ICU) and return to work.METHODS: This Danish nationwide cohort-study included 30-day-OHCA-survivors who were employed prior to arrest. We linked OHCA data to information on in-hospital care and return to work. For patients admitted to an ICU and based on renal replacement therapy (RRT), cardiovascular support and mechanical ventilation, we assessed the prognostic value of organ support therapies in multivariable Cox regression models.RESULTS: Of 1,087 30-day survivors, 212 (19.5%) were treated in an ICU with 0-1 types of organ support, 494 (45.4%) with support of two organs, 26 (2.4%) with support of three organs and 355 (32.7%) were not admitted to an ICU. Return to work increased with decreasing number of organs supported, from 53.8% (95% CI: 49.5-70.1%) in patients treated with both RRT, cardiovascular support and mechanical ventilation to 88.5% (95% CI: 85.1-91.8%) in non-ICU-patients. In 732 ICU-patients, ICU-patients with support of 3 organs had significantly lower adjusted hazard ratios (HR) of returning to work (0.50 [95% CI: 0.30-0.85] compared to ICU-patients with support of 0-1 organ. The corresponding HR was 0.48 [95% CI: 0.30-0.78] for RRT alone.CONCLUSIONS: In 30-day survivors of OHCA, number of organ support therapies and in particular need of RRT were associated with reduced rate of return to work, although more than half of these latter patients still returned to work.</p

Computational Investigation of RO2 + HO2 and RO2 + RO2 Reactions of Monoterpene Derived First-Generation Peroxy Radicals Leading to Radical Recycling

The oxidation of biogenically emitted volatile organic compounds (BVOC) plays an important role in the formation of secondary organic aerosols (SOA) in the atmosphere. Peroxy radicals (RO2) are central intermediates in the BVOC oxidation process. Under clean (low-NOx) conditions, the main bimolecular sink reactions for RO2 are with the hydroperoxy radical (HO2) and with other RO2 radicals. Especially for small RO2, the RO2 + HO2 reaction mainly leads to closed-shell hydroperoxide products. However, there exist other known RO2 + HO2 and RO2 + RO2 reaction channels that can recycle radicals and oxidants in the atmosphere, potentially leading to lower-volatility products and enhancing SOA formation. In this work, we present a thermodynamic overview of two such reactions: (a) RO2 + HO2 -> RO + OH + O-2 and (b) R'O-2 + RO2 -> R'O + RO + O-2 for selected monoterpene + oxidant derived peroxy radicals. The monoterpenes considered are alpha-pinene, beta-pinene, limonene, trans-beta-ocimene, and Delta(3)-carene. The oxidants considered are the hydroxyl radical (OH), the nitrate radical (NO3), and ozone (O-3). The reaction Gibbs energies were calculated at the DLPNO-CCSD(T)/def2-QZVPP//omega B97X-D/aug-cc-pVTZ level of theory. All reactions studied here were found to be exergonic in terms of Gibbs energy. On the basis of a comparison with previous mechanistic studies, we predict that reaction a and reaction b are likely to be most important for first-generation peroxy radicals from O-3 oxidation (especially for beta-pinene), while being less so for most first-generation peroxy radicals from OH and NO3 oxidation. This is because both reactions are comparatively more exergonic for the O-3 oxidized systems than their OH and NO3 oxidized counterparts. Our results indicate that bimolecular reactions of certain complex RO, may contribute to an increase in radical and oxidant recycling under high HO2 conditions in the atmosphere, which can potentially enhance SOA formation.Peer reviewe

Pathways to Highly Oxidized Products in the Delta 3-Carene + OH System

Oxidation of the monoterpene Delta 3-carene (C10H16) is a potentially important and understudied source of atmospheric secondary organic aerosol (SOA). We present chamber-based measurements of speciated gas and particle phases during photochemical oxidation of Delta 3-carene. We find evidence of highly oxidized organic molecules (HOMs) in the gas phase and relatively low-volatility SOA dominated by C-7-C-10 species. We then use computational methods to develop the first stages of a Delta 3-carene photochemical oxidation mechanism and explain some of our measured compositions. We find that alkoxy bond scission of the cyclohexyl ring likely leads to efficient HOM formation, in line with previous studies. We also find a surprising role for the abstraction of primary hydrogens from methyl groups, which has been calculated to be rapid in the alpha-pinene system, and suggest more research is required to determine if this is more general to other systems and a feature of autoxidation. This work develops a more comprehensive view of Delta 3-carene photochemical oxidation products via measurements and lays out a suggested mechanism of oxidation via computationally derived rate coefficients.Peer reviewe