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This study is to investigate the natural metatasophalangeal joint (MTP) distance, the appropriate degree of distraction and the associated factors including age, gender, body mass index(BMI). Regarding natural MTP joint space size, the MTP-2 joint had the largest joint size (2.39 ± 0.37 mm). The MTP-5 joint had the smallest joint size (1.59 ± 0.34 mm). In MTP joint arthroscopy, traction power of 10 lbs is sufficient for appropriate distraction for all MTP joints while traction power of 5 lbs is an appropriate power for distraction of the MTP-2 joint. Manual traction is generally not appropriate for distraction because it is not consistent or sufficient. Less distraction power is required for males than for females, especially for MTP-1, MTP-3, and MTP-4 joints.

Rationale: Lisfranc injuries are a dislocation of the metatarsal bones from the tarsal bone. Although closed reduction is possible in most cases of Lisfranc injury when attempted in the early stage, there are some rare cases for which open reduction is required. Herein we report a case of irreducible Lisfranc injury in a 34-year-old man who presented to our institution with painful swelling. Patient concerns: We report a 34-year-old man presented to our institution with painful swelling after a fall from 1.0 m height. Diagnoses: We diagnosed it as irreducible Lisfranc injury by tibialis anterior tendon entrapment through plain radiologic study and surgical findings. Interventions: Plain X-ray, C-arm fluoroscopy and open surgery were performed. Outcomes: We did a closed reduction under a C-arm fluoroscopic guide, but it was not successful. Thus, we had to do an open reduction of a Lisfranc dislocation. Upon exposure, we observed the entrapment of the tibialis anterior tendon between the medial and intermediate cuneiform bones. Lessons: Our report is valuable in that it can contribute to the diagnosis and suggest a clue to the treatment of such a rare pathology. The knowledge in the rare case of entrapment of the tibialis tendon and the understanding of management will be useful when a irreducible Lisfranc dislocation is unsuccessful after an attempt at closed reduction.

Contactin-associated protein-like 4 (Cntnap4) is a member of the neurexin superfamily of transmembrane molecules that have critical functions in neuronal cell communication. Cntnap4 knockout mice display decreased presynaptic gamma-aminobutyric acid (GABA) and increased dopamine release that is associated with severe, highly penetrant, repetitive, and perseverative movements commonly found in human autism spectrum disorder patients. However, no known function of Cntnap4 has been revealed besides the nervous system. Meanwhile, secretory protein neural EGFL-like 1 (Nell-1) is known to exert potent osteogenic effects in multiple small and large animal models without the off-target effects commonly found with bone morphogenetic protein 2. In this study, while searching for a Nell-1-specific cell surface receptor during osteogenesis, we identified and validated a ligand/receptor-like interaction between Nell-1 and Cntnap4 by demonstrating: 1) Nell-1 and Cntnap4 colocalization on the surface of osteogenic-committed cells; 2) high-affinity interaction between Nell-1 and Cntnap4; 3) abrogation of Nell-1-responsive Wnt and MAPK signaling transduction, as well as osteogenic effects, via Cntnap4 knockdown; and 4) replication of calvarial cleidocranial dysplasias-like defects observed in Nell-1-deficient mice in Wnt1-Cre-mediated Cntnap4-knockout transgenic mice. In aggregate, these findings indicate that Cntnap4 plays a critical role in Nell-1-responsive osteogenesis. Further, this is the first functional annotation for Cntnap4 in the musculoskeletal system. Intriguingly, Nell-1 and Cntnap4 also colocalize on the surface of human hippocampal interneurons, implicating Nell-1 as a potential novel ligand for Cntnap4 in the nervous system. This unexpected characterization of the ligand/receptor-like interaction between Nell-1 and Cntnap4 indicates a novel biological functional axis for Nell-1 and Cntnap4 in osteogenesis and, potentially, in neural development and function. © 2018 American Society for Bone and Mineral Research.

Fractures are common, with an incidence of 13.7 per 1000 adults annually. Systemic agents have been widely used for enhancing bone regeneration; however, the efficacy of these therapeutics for the management and prevention of fracture remains unclear. NEL-like protein 1 (NELL-1) is a potent pro-osteogenic cytokine that has been modified with polyethylene glycol (PEG)ylation [PEGylated NELL-1 (NELL-PEG)] to enhance its pharmacokinetics for systemic therapy. Our aim was to investigate the effects of systemic administration of NELL-PEG on fracture healing in mice and on overall bone properties in uninjured bones. Ten-week-old CD-1 mice were subjected to an open osteotomy of bilateral radii and treated with weekly injections of NELL-PEG or PEG phosphate-buffered saline as control. Systemic injection of NELL-PEG resulted in improved bone mineral density of the fracture site and accelerated callus union. After 4 weeks of treatment, mice treated with NELL-PEG exhibited substantially enhanced callus volume, callus mineralization, and biomechanical properties. NELL-PEG injection significantly augmented bone regeneration, as confirmed by high expression of bone turnover rate, bone formation rate, and mineral apposition rate. Consistently, the immunohistochemistry results also confirmed a high bone remodeling activity in the NELL-PEG-treated group. Our findings suggest that weekly injection of NELL-PEG may have the clinical potential to accelerate fracture union and enhance overall bone properties, which may help prevent subsequent fractures.

The causes of late-onset pain after total ankle replacement (TAR) are various, and include infection, subsidence, polyethylene spacer failure, osteolysis, and wear. There are few reports of late-onset pain caused by gouty attacks after total knee and hip arthroplasty. In addition, no research has reported gouty attacks after total ankle arthroplasty. Therefore, we report a case of a gouty attack after total ankle replacement. A 43-year-old man presented with pain after total ankle arthroplasty performed 5 years previously. We found a white-yellow crystalline deposit within the synovial tissue during ankle arthroscopy, confirmed by histologic examination.

Dislocation of the lunate and proximal pole of the scaphoid with displacement of the fragments proximal to the radiocarpal joint, characterized as a total dislocation, is very rare, with only six cases reported. Dislocated lunate are generally located around the radiocarpal joint or within carpal ligament. However, there have been no reports of dislocated lunate over the carpal ligament. We present the case of a patient with volar dislocation of the lunate that featured extreme migration to approximately 6 cm proximal to flexor digitorum superficialis through the transcarpal ligament. DOI: 10.3944/AOTT.2015.14.0428This abstract belongs to the un-edited version of the article and is only for informative purposes. Published version may differ from the current version.

Upregulation of Nell-1 has been associated with craniosynostosis (CS) in humans, and validated in a mouse transgenic Nell-1 overexpression model. Global Nell-1 inactivation in mice by N-ethyl-N-nitrosourea (ENU) mutagenesis results in neonatal lethality with skeletal abnormalities including cleidocranial dysplasia (CCD)-like calvarial bone defects. This study further defines the role of Nell-1 in craniofacial skeletogenesis by investigating specific inactivation of Nell-1 in Wnt1 expressing cell lineages due to the importance of cranial neural crest cells (CNCCs) in craniofacial tissue development. Nell-1(flox/flox); Wnt1-Cre (Nell-1(Wnt1) KO) mice were generated for comprehensive analysis, while the relevant reporter mice were created for CNCC lineage tracing. Nell-1(Wnt1) KO mice were born alive, but revealed significant frontonasal and mandibular bone defects with complete penetrance. Immunostaining demonstrated that the affected craniofacial bones exhibited decreased osteogenic and Wnt/β-catenin markers (Osteocalcin and active-β-catenin). Nell-1-deficient CNCCs demonstrated a significant reduction in cell proliferation and osteogenic differentiation. Active-β-catenin levels were significantly low in Nell-1-deficient CNCCs, but were rescued along with osteogenic capacity to a level close to that of wild-type (WT) cells via exogenous Nell-1 protein. Surprisingly, 5.4% of young adult Nell-1(Wnt1) KO mice developed hydrocephalus with premature ossification of the intrasphenoidal synchondrosis and widened frontal, sagittal, and coronal sutures. Furthermore, the epithelial cells of the choroid plexus and ependymal cells exhibited degenerative changes with misplaced expression of their respective markers, transthyretin and vimentin, as well as dysregulated Pit-2 expression in hydrocephalic Nell-1(Wnt1) KO mice. Nell-1(Wnt1) KO embryos at E9.5, 14.5, 17.5, and newborn mice did not exhibit hydrocephalic phenotypes grossly and/or histologically. Collectively, Nell-1 is a pivotal modulator of CNCCs that is essential for normal development and growth of the cranial vault and base, and mandibles partially via activating the Wnt/β-catenin pathway. Nell-1 may also be critically involved in regulating cerebrospinal fluid homeostasis and in the pathogenesis of postnatal hydrocephalus.

In 2010, the Korean government launched a new funding scheme for social scientists, Social Science Korea (SSK). Contrary to conventional grant programs, the SSK adopted a competition scheme among research teams by eliminating those who failed to pass annual evaluations, while, at the same time, emphasizing cooperation and interdisciplinary research. Substantial research has documented the determinants of receiving research grants in Western countries, but little is known about how these determinants operate in Korean academia. Using results from the stage evaluations of the SSK, we estimate logistic regression models. The results indicate that factors of meritocracy, such as publication record, strongly affect the likelihood of success, but so do political factors, such as a PI obtaining his or her doctoral degree from a foreign institution. The importance of a PI’s gender and age, and of being located in Seoul, is not supported by the data.

Trabecular bone is frequently studied in osteoporosis research because changes in trabecular bone are the most common cause of osteoporotic fractures. Dual energy X-ray absorptiometry (DXA) analysis specific to trabecular bone-rich regions is crucial to longitudinal osteoporosis research. The purpose of this study is to define a novel method for accurately analyzing trabecular bone-rich regions in mice via DXA. This method will be utilized to analyze scans obtained from the International Space Station in an upcoming study of microgravity-induced bone loss. Thirty 12-week-old BALB/c mice were studied. The novel method was developed by preanalyzing trabecular bone-rich sites in the distal femur, proximal tibia, and lumbar vertebrae via high-resolution X-ray imaging followed by DXA and micro-computed tomography (micro-CT) analyses. The key DXA steps described by the novel method were (1) proper mouse positioning, (2) region of interest (ROI) sizing, and (3) ROI positioning. The precision of the new method was assessed by reliability tests and a 14-week longitudinal study. The bone mineral content (BMC) data from DXA was then compared to the BMC data from micro-CT to assess accuracy. Bone mineral density (BMD) intra-class correlation coefficients of the new method ranging from 0.743 to 0.945 and Levene's test showing that there was significantly lower variances of data generated by new method both verified its consistency. By new method, a Bland–Altman plot displayed good agreement between DXA BMC and micro-CT BMC for all sites and they were strongly correlated at the distal femur and proximal tibia (r=0.846, p

The primary goal of this paper is to provide a balanced perspective for understanding inequality in research productivity among Korean scholars in humanities and social sciences. Specifically, we examine cumulative advantage over the careers of a sample of Korean social scientists and humanities scholars (N = 8933). Descriptive analyses indicated that the level of inequality among junior humanists and social scientists rivals that found among similar scholars in the USA, and among engineers and natural scientists in Korea. Inequality indices examined over 25 years reveal a U-shaped trajectory for social scientists and an L-shaped trajectory for humanities scholars. In both disciplines, female scholars averaged fewer publications than their male counterparts at any given time in their respective careers. Furthermore, according to results from generalized estimating equations, age at receipt of doctorate and years to doctoral degree completion were negatively associated with the number of publications. The prestige of scholars’ undergraduate and graduate schools also appears to be associated with productivity, though to a greater extent in the social sciences than in the humanities. The results imply that the incentive structure in Korean academia does not necessarily lead to an increase in the number of publications. Rather, it appears that, in the later career stages, activities outside the university become more important than scholarly performance, perhaps due to the tradition of basing wage and promotion systems on seniority.

Category: Arthroscopy; Bunion; Lesser Toes Introduction/Purpose: Appropriate distraction for metatarsophalangeal joint arthroscopy is paramount to increase in visualization and to decrease iatrogenic complications. However, there are few studies on how much adequate distraction is. The purpose of this study was to investigate the appropriate degree of distraction and the associated factors. Methods: 40 patients who underwent toe arthroscopy from April 2015 to June 2018 were enrolled. Under general or spinal anesthesia, the anterio-posterior foot plain radiograph were taken using mini-fluoroscan; no traction, manual traction, 5, 10 and 15 pound traction and were used to measure the metatasophalangeal joint (MTP) distance. Age, gender, body mass index were compared as associated factors. The minimum joint distance of toe arthroscopy defined as 2.8mm which was sheath size of 1.9mm 30° high definition arthroscopy. Appropriate distraction is defined as an over 70% possible rate. Results: 10lb traction was appropriate distraction on first and fourth MTP joint arthroscopy. 5lb traction was appropriate on second, third, fifth MTP. In first MTP with 5lb traction, there was significant difference according to gender; 9 of 23 male, none of 17 female. (p=0.005). With 10lb traction, 16 of 27 patients under 60 and 3 of 13 patients over 60 years old were could arthroscopy (p=0.046). In third MTP with 5lb traction, 18 of 28 patients over 30 were could arthroscopy, but only 4 of 13 under 30 years old were could(p=0.038). In fourth MTP with 5lb traction, there was significant difference according to gender, male (12 of 23 patients) was had arthroscopy, but only 2 of 17 female patients. (p=0.017). Conclusion: In the MTP joint arthroscopy, 10lb was needed in first and fourth MTP joint, and 5lb was needed in second, third, fifth MTP joint. Manual traction is generally not appropriate for distraction. Female and under 60 years old patients needed more distraction in first toe arthroscopy. Under 30 years old patients in third toe and female patients in fourth toe arthroscopy needed more distraction than 5lb. [Table: see text]

Tumorigenicity is a well-documented risk to overcome for pluripotent or multipotent cell applications in regenerative medicine. To address the emerging demand for safe cell sources in tissue regeneration, we established a novel, protein-based reprogramming method that does not require genome integration or oncogene activation to yield multipotent fibromodulin (FMOD)-reprogrammed (FReP) cells from dermal fibroblasts. When compared with induced pluripotent stem cells (iPSCs), FReP cells exhibited a superior capability for bone and skeletal muscle regeneration with markedly less tumorigenic risk. Moreover, we showed that the decreased tumorigenicity of FReP cells was directly related to an upregulation of cyclin-dependent kinase inhibitor 2B (CDKN2B) expression during the FMOD reprogramming process. Indeed, sustained suppression of CDKN2B resulted in tumorigenic, pluripotent FReP cells that formed teratomas in vivo that were indistinguishable from iPSC-derived teratomas. These results highlight the pivotal role of CDKN2B in cell fate determination and tumorigenic regulation and reveal an alternative pluripotent/multipotent cell reprogramming strategy that solely uses FMOD protein.

NELL-1, an osteoinductive protein, has been shown to regulate skeletal ossification. Interestingly, an interstitial 11p14.1-p15.3 deletion involving the Nell-1 gene was recently reported in a patient with short stature and delayed fontanelle closure. Here we sought to define the role of Nell-1 in endochondral ossification by investigating Nell-1-specific inactivation in Col2α1-expressing cell lineages. Nell-1flox/flox ; Col2α1-Cre+ (Nell-1Col2α1 KO) mice were generated for comprehensive analysis. Nell-1Col2α1 KO mice were born alive but displayed subtle femoral length shortening. At 1 and 3 months postpartum, Nell-1 inactivation resulted in dwarfism and premature osteoporotic phenotypes. Specifically, Nell-1Col2α1 KO femurs and tibias exhibited significantly reduced length, bone mineral density (BMD), bone volume per tissue volume (BV/TV), trabecular number/thickness, cortical volume/thickness/density, and increased trabecular separation. The decreased bone formation rate revealed by dynamic histomorphometry was associated with altered numbers and/or function of osteoblasts and osteoclasts. Furthermore, longitudinal observations by in vivo micro-CT showed delayed and reduced mineralization at secondary ossification centers in mutants. Histologically, reduced staining intensities of Safranin O, Col-2, Col-10, and fewer BrdU-positive chondrocytes were observed in thinner Nell-1Col2α1 KO epiphyseal plates along with altered distribution and weaker expression level of Ihh, Patched-1, PTHrP, and PTHrP receptor. Primary Nell-1Col2α1 KO chondrocytes also exhibited decreased proliferation and differentiation, and its downregulated expression of the Ihh-PTHrP signaling molecules can be partially rescued by exogenous Nell-1 protein. Moreover, intranuclear Gli-1 protein and gene expression of the Gli-1 downstream target genes, Hip-1 and N-Myc, were also significantly decreased with Nell-1 inactivation. Notably, the rescue effects were diminished/reduced with application of Ihh signaling inhibitors, cyclopamine or GANT61. Taken together, these findings suggest that Nell-1 is a pivotal modulator of epiphyseal homeostasis and endochondral ossification. The cumulative chondrocyte-specific Nell-1 inactivation significantly impedes appendicular skeletogenesis resulting in dwarfism and premature osteoporosis through inhibiting Ihh signaling and predominantly altering the Ihh-PTHrP feedback loop. © 2018 American Society for Bone and Mineral Research.

Collaborative research has become more prevalent and important across disciplines because it stimulates innovation and interaction between scholars. Seeing as existing studies relatively disregarded the institutional conditions triggering collaborative research, this work aims to analyze the changing trend in collaborative work patterns among Korean social scientists. The focus of this research is the performance of social scientists who received research grants through the government’s Social Science Korea (SSK) program. Using quantitative statistical methods, collaborative research patterns in a total of 2,354 papers published under the umbrella of the SSK program in peer-reviewed scholarly journals from 2013 to 2016 were examined to identify changing trends and triggering factors in collaborative research. A notable finding is that the share of collaborative research is overwhelmingly higher than that of individual research. In particular, levels of collaborative research surpassed 70%, increasing much quicker compared to other research done in the social sciences. Additionally, the most common composition of collaborative research was for two or three researchers to conduct joint research as coauthors, and this proportion has also increased steadily. Finally, a strong association between international journals and co-authorship patterns was found for the papers published by SSK program researchers from 2013 to 2016. The SSK program can be seen as the driving force behind collaboration between social scientists. Its emphasis on competition through a merit-based financial support system along with a rigorous evaluation process seems to have influenced researchers to cooperate with those who have similar research interests., {"references":["D. N. Laband and R. D. Tollison. 2000. \"Intellectual Collaboration.\" Journal of Political Economy 108: 632-662.","D. H. Sonnenwald. 2007. \"Scientific Collaboration.\" Annual Review of Information Science and Technology 41(1): 643-681.","J. W. Endersby. 1996. \"Collaboration Research in the Social Sciences: Multiple Authorship and Publication Credit.\" Social Science Quarterly 77(2): 375-392.","S. Wuchty, B. F. Jones, and B. Uzzi. 2007. \"The Increasing Dominance of Teams in Production of Knowledge.\" Science 316(5827): 1036-1039.","B. S. Fisher, C. T. Cobane, T. M. Vander Ven, F. T. Cullen. 1998. \"How Many Authors Does It Take to Publish an Article? Trends and Patterns in Political Science.\" Political Science Online 847-856.","J. Han and S. Kim. 2017. \"How Rankings Change Universities and Academic Fields in Korea.\" Korean Journal of Sociology 51(1): 1-37. (In Korean).","J. Moody. 2004. \"The Structure of a Social Science Collaboration Network: Disciplinary Cohesion from 1963 to 1999.\" American Sociological Review 69(2): 213-238.","K. Kim and J. K. Kim. 2016. \"Meritocracy in the Awarding of Research Grants? Evidence from Social Science Korea.\" Korean Social Science Journal 43: 1-13.","S. H. Park, J.K. Kim, and D. H. Kim. 2014. \"Exploratory Study for Research Collaboration of Social Scientists in Korea.\" Discourse 201 17(1): 1-37. (In Korean).\n[10]\tR. Guimera, B. Uzzi, J. Shapiro, and L. A. Amaral. 2005. \"Team Assembly Mechanisms Determine Collaboration Network Structure and Team Performance.\" Science 308(5722): 697-702. \n[11]\tM. Newman. 2004. \"Collaboration Networks and Patterns of Scientific Collaboration.\" Proceedings of the National Academy of Science 101 (suppl 1):5200-5205.\n[12]\tP. Bourdieu. 1991. \"Epilogue: On the Possibility of a Field of World Sociology.\" Pp. 373-387 in Social Theory for a Changing Society, edited by Pierre Bourdieu and James S. Coleman. Boulder, CO: Westview Press. \n[13]\tM. Fourcade. 2006. \"The Construction of a Global Profession: The Transnationalization of Economics.\" American Journal of Sociology 112(1): 145-194. \n[14]\tJ. Heilbron. 2014. \"The Social Sciences as an emerging global field.\" Current Sociology 62(6): 685-703. \n[15]\tR. Collins. 2000. \"The Sociology of Philosophies: A Precis.\" Philosophy of the Social Sciences 30(2): 157-201.\n[16]\tN. Mullins. 1973. Theories and Theory Groups in Contemporary American Sociology. New York, NY: Harper & Row Publishers. \n[17]\tE. Ollion and A. Abbott. 2016. \"French Connections: The Reception of French Sociologists in the USA.\" European Journal of Sociology 57(2): 331-372. \n[18]\tD. J. de Solla Price. 1986. Little Science, Big Science ... and Beyond. New York, NY: Columbia University Press."]}

Bone morphogenetic proteins (BMPs) are crucial regulators of chondrogenesis. BMPs transduce their signals through three type I receptors: BMPR1A, BMPR1B, and ACVR1/ALK2. Fibrodysplasia ossificans progressiva (FOP), a rare disorder characterized by progressive ossification of connective tissue, is caused by an activating mutation in Acvr1 (the gene that encodes ACVR1/ALK2). However, there are few developmental defects associated with FOP. Thus, the role of ACVR1 in chondrogenesis during development is unknown. Here we report the phenotype of mice lacking ACVR1 in cartilage. Acvr1(CKO) mice are viable but exhibit defects in the development of cranial and axial structures. Mutants exhibit a shortened cranial base, and cervical vertebrae are hypoplastic. Acvr1(CKO) adult mice develop progressive kyphosis. These morphological defects were associated with decreased levels of Smad1/5 and p38 activation, and with reduced rates of chondrocyte proliferation in vertebral cartilage. We also tested whether ACVR1 exerts coordinated functions with BMPR1A and BMPR1B through analysis of double mutants. Acvr1/Bmpr1a and Acvr1/Bmpr1b mutant mice exhibited generalized perinatal lethal chondrodysplasia that was much more severe than in any of the corresponding mutant strains. These findings demonstrate that ACVR1 is required for chondrocyte proliferation and differentiation, particularly in craniofacial and axial elements, but exerts coordinated functions with both BMPR1A and BMPR1B throughout the developing endochondral skeleton.

Pedicle screw fixation is the gold standard for the treatment of spinal diseases. However, many studies have reported the issue of loosening pedicle screws after spinal surgery, which is a serious concern. To address this problem, diverse types of pedicle screws have been examined to identify those with good fixation strength and osseointegration in spine bone. The porcine spine is a good alternative for the human spine in the evaluation of pedicle screws due to the anatomical size, mechanical characteristics, and cost. Although several studies have reported that pedicle screws are efficient in the porcine model, no study has described detailed protocols for the evaluation of a pedicle screw using the porcine model. Here, we describe a detailed method for evaluating transpedicular screws using an in vivo porcine lumbar spine model. The technical details for anesthesia, spine surgery, and harvest provided here will facilitate with the evaluation of the transpedicular screw fixation model.

Stem cells are poorly permissive to non-viral gene transfection reagents. In this study, we explored the possibility of improving gene delivery into human embryonic (hESC) and mesenchymal (hMSC) stem cells by synergizing the activity of a cell-binding ligand with a polymer that releases nucleic acids in a cytoplasm-responsive manner. A 29 amino acid long peptide, RVG, targeting the nicotinic acetylcholine receptor (nAchR) was identified to bind both hMSC and H9-derived hESC. Conjugating RVG to a redox-sensitive biodegradable dendrimer-type arginine-grafted polymer (PAM-ABP) enabled nanoparticle formation with plasmid DNA without altering the environment-sensitive DNA release property and favorable toxicity profile of the parent polymer. Importantly, RVG-PAM-ABP quantitatively enhanced transfection into both hMSC and hESC compared to commercial transfection reagents like Lipofectamine 2000 and Fugene. ∼60% and 50% of hMSC and hESC were respectively transfected, and at increased levels on a per cell basis, without affecting pluripotency marker expression. RVG-PAM-ABP is thus a novel bioreducible, biocompatible, non-toxic, synthetic gene delivery system for nAchR-expressing stem cells. Our data also demonstrates that a cell-binding ligand like RVG can cooperate with a gene delivery system like PAM-ABP to enable transfection of poorly-permissive cells.

The authority of the state and the market, the duumvirate of the industrial society, has been challenged in various ways in the current information era advanced by the rapid development of information and communication technology. By comparison, the weight of civil organizations has increased sharply, and netizens equipped with information technology have emerged as a major player in civil society. This article experientially examines the changes in power dynamics of the state, the market, and civil society in the Korean context, based on a survey of people's perception of the communication adaptiveness of these spheres, that is, their openness and exclusiveness internally and externally. The survey results suggest that the state sphere tends to be perceived as less communicative and open than the market and civil society. By contrast, civil society is perceived to be the most open and communicative sphere. This may reflect some change in power dynamics of these spheres, which can be characterized as the ...

The textural properties of TiO2–SiO2 composites (TSCs) were successively enhanced using three approaches; (1) washing the hydrogels with different solvents, (2) using surfactant and (3) forming the TiO2 sol in ethanol medium. The sol–gel process was exquisitely used to form the composites using cost effective precursors. Initially, the precipitated hydrogels were washed with water or alcohol to evaluate the influence of washing on the dried hydrogels. Consequently, two composites were formed differently in the presence of stearic acid (SA) as a surfactant and the other by forming TiO2 sol in ethanol medium prior to reaction with silica source. The TSC powders were examined by XRD, N2 physisorption studies, FTIR, TGA, SEM, XRF and HRTEM. The BET surface area of the sample obtained after washing the hydrogels with ethanol (TSCE) was the largest (594 m2/g) while porosities of the composites obtained using stearic acid as a surfactant (TSCSA, 0.96 cm3/g) and ethanol as a medium to form the TiO2 sol (TSCES, 1.85 cm3/g) were relatively superior to those obtained under influence of changing washing solvent. Photocatalytic decolorization of methylene blue by the composites calcined at 800 °C revealed that the TSCES-800 possessed the highest activity of all the composites due to its superior properties.

The shortage of safe drinking water in developing countries and at the sites of natural disaster has spurred scientists to develop more effective materials for water disinfection at the point of use. In the present study, silver nanoparticle supported silica beads (Ag-NPBs) with sizes ranging from 0.5 to 1 mm were prepared, and their potential for water disinfection was examined. Escherichia coli was utilized to assess water disinfection potential by flow tests using a filter column filled with Ag-NPBs. Ag-NPBs inactivated > 99% of E. coli with a contact time of several seconds when the input water had a bacterial load of approximately 10 6 colony-forming units per mL. Ag-NPBs have an antibacterial capacity of 4.5 L/g. The effect of ammonium and urea on the release rate of silver into filtrate was investigated. The results suggest that Ag-NPBs could be an effective material for water disinfection.

Thiol-functionalized silica that has been used to remove heavy metal from an aqueous solution and support metallic nanoparticles is usually synthesized by reflux in an organic solvent containing 3-mercaptopropyltrimethoxysilane (MPTMS). In this paper, we report a gentle method for grafting thiol-functional groups onto silica gel by an aging process that does not require mixing and refluxing in an organic solvent. Silica gel was synthesized by a sol–gel method from H2SO4 (40%) and sodium silicate, which was crushed into beads with sizes ranging from 180 to 450 μm. Silica beads (50 g) were mixed with 75 mL of a functionalization solution consisting of MPTMS, H2O, and C2H5OH and aged at 50 °C for 36 h in a box dryer. The success of the functionalization process was confirmed by FT-IR, BET, SEM and elemental analyses. The functionalization solution was percolated into pores and thiol-functional groups were grafted onto the surface and pore walls of the silica beads. The ability of these functionalized silica beads to adsorb silver ions was determined by the Langmuir isotherm equation with a maximum adsorption of 75.8 mg/g. Silver nanoparticles with sizes ranging from 2 to 6 nm formed by chemical reduction were located inside the pores and on the surfaces.

This study reports on the quantitative recovery of high purity nanoporous silica from wastes material (H2SiF6) of the phosphate fertilizer industry and Na2O·SiO2. The silica recovered from the wastes was compared with silica from the reaction of H2SO4 and Na2O·SiO2 because H2SO4 is commonly used. The product recovered from the wastes material and H2SO4 were 99.3% and 99.1% pure, respectively. The quantity recovered were 22.30 g and 20.11 g, respectively. The product had superior properties suitable for applications such as chromatography, reinforcing material for rubber and plastics. The process may significantly reduce the release of SiF4 gas into the environment.

\Titania–silica composites (TSC) with various Ti/Si ratios were synthesized via sol–gel process using less expensive precursors; sodium silicate solution as a silica source and titanium oxychloride as a titania source. The influence of varying Ti content in the composites was examined by FTIR, SEM, TEM, DTA/TGA, N2 physisorption studies, XRF and XRD. The BET surface area of the raw materials increased with increasing Ti/Si ratio up to 2.9 (461 m2/g) but further increase of Ti content beyond that ratio yielded composites with decreased surface area. The effect of aging evaluated in the sample with Ti/Si = 2.9 revealed that aging the composite for 2 h yields titania–silica powder with the highest surface area (461 m2/g). The FTIR analysis displayed the presence of a vibration band at 945 cm− 1, assignable to hetero linkage of the Si–O–Ti depicting the incorporation of TiO2 into SiO2 to form a composite. Moreover, photodegradation of methyl orange (MO) by the samples calcined at 800 °C showed that the TSC-5-800 (Ti/Si = 5.6) exhibited the highest maximum photocatalytic activity of all the composites.

siRNA entrapment within endosomes is a significant problem encountered with siRNA delivery platforms that co-opt receptor-mediated entry pathways. Attachment of a cell-penetrating peptide (CPP), such as nona-arginine (9R) to a cell receptor-binding ligand like the Rabies virus glycoprotein, RVG, allows effective siRNA delivery to the cytoplasm by non-endocytic pathways, but a significant amount of siRNA complexes also enters the cell by ligand-induced receptor endocytosis and remain localized in endosomes. Here, we report that the incorporation of trileucine (3 Leu) residues as an endo-osmolytic moiety in the peptide improves endosomal escape and intracellular delivery of siRNA. The trileucine motif did not affect early non-endosomal mechanism of cytoplasmic siRNA delivery but enhanced target gene silencing by 20% only beyond 24 h of transfection when siRNA delivery is mostly through the endocytic route and siRNA trapped in the endosomes at later stages were subject to release into cytoplasm. The mechanism may involve endosomal membrane disruption as trileucine residues lysed RBCs selectively under endosomal pH conditions. Interestingly 3 Leu or 3 Leu residues were not as effective, suggesting that 3 Leu residues are useful for enhancing cytoplasmic delivery of siRNA routed through endosomes.

Controlling the properties of precipitated silica (PS) synthesized by acidizing sodium silicate solution is a significant challenge. Here, we report the effect of gelation on the BET surface area and pore volume of the PS produced at the pilot scale. H2SO4 was added to a mixture of sodium silicate and sodium chloride in two stages: the first stage ends before the gelation point and the second one ends as pH of solution reached to 5. The interval (Δt) from the end of the first stage to the gelation point was recorded to evaluate its effect on the properties of the resulting PS. The obtained samples were characterized by nitrogen adsorption–desorption method, field emission scanning electron microscopy (FE-SEM), and field emission scanning transmission electron microscopy (FE-STEM). The results revealed that the BET surface area and pore volume of the prepared PS decreases with the increase of Δt and temperature, while the pore size is not affected. The variations in the properties of the PS were successfully explained by the application of a percolation model to the flocculation and bridging of the primary particles.

In this article we report synthesis of mesoporous silica with superior properties for application in green tire (environmentally friendly tire) as filler. The synthesis was done using a newly innovated apparatus which produce mesoporous silica with superior properties. The desired superior properties are big pore size, optimum BET, large pore volume, uniform properties, and improved performance in real application as tire filler. Mesoporous silica was characterized by BET method and final product with a pore diameter of up to 37 nm was obtained without using surfactants. This is unprecedented step toward synthesis of silica that is suitable for tire industry.

We report a two-step rapid route of synthesizing inexpensive mesoporous silica using the waste material (hexafluorosilicic acid, H2SiF6) of phosphate fertilizer industry and sodium silicate (Na2O·SiO2). The reaction was performed in a newly innovated manufacturing apparatus. This apparatus produces mesoporous silica with uniform properties through controlled mixing of source materials at predetermined equivalent ratio. The precursors are rapidly mixed within the nozzles to enable uniform control of physical properties of the final product. The obtained mesoporous silica was characterized using N2 physisorption studies, scanning electron microscope (SEM), and EDS. The final product was found to have superior properties that are suitable for green tire (environmentally friendly tire) as inorganic filler. The process reported in this study may significantly reduce the release of hazardous materials into the environment and it might confer economic benefits to the responsible industries. A project on innovative industrial application of our products for the tire industry is in progress.

Here, we report on the synthesis of silver nanoparticles (Ag-NPs) manipulating the pores of silica beads (SBs) with sizes ranging from 0.5 to 1 mm. Silver ions were occluded inside the pores of SBs and in situ reduced to Ag-NPs using Sodium borohydride (NaBH 4 ). SBs with different average pore diameters from 3.8 to 20 nm were used to assess the effect of their pore sizes and porous structures on the formation of Ag-NPs. Obtained results revealed that the silver amount occluded inside pores increases along with the increase of total pore volume. The particle sizes of the synthesized Ag-NPs mainly distribute from 8 to 15 nm and vary with the pore sizes and porous structure.

Mesoporous titania–silica composite (MTSC) with a large surface area (387 m 2 /g) and large pore volume was synthesized by a two step condensation sol–gel method. Transparent TiO 2 sol was formed at room temperature through condensation and peptization of titanium oxychloride solution using ammonium hydroxide and aqueous nitric acid respectively. Sodium silicate was used as a silica source to form a composite with the preformed TiO 2 sol. The physical properties of the composite were examined by Fourier Transform infrared (FTIR), BET surface area, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The nitrogen physisorption behavior of the synthesized composite was compared to that obtained from grafting and one-pot co-condensation methods using the same precursors in the presence of cetyltrimethylammonium bromide (CTAB). It was found that MTSC synthesized under this method possessed large pore sizes and pore volume but its thermal stability was comparatively low. FTIR spectra showed the formation of a Ti O Si bond at 940 cm − 1 suggesting that titania was incorporated in silica to form a composite. The XRD patterns showed that the major phase of the titania had an anatase phase up to 900 °C but it transforms into rutile when calcined at 1000 °C. Furthermore the EDS studies of the as-synthesized and calcined samples substantiated the formation of titania–silica composites.