The main goal of this study is to investigate the effectiveness of seismic retrofit using CFRP wrapping in reducing the damage and preventing the failure of RC bridge piers under vehicular impacts. ...This paper reports the results of an experimental investigation on the performance of cantilever CFRP-wrapped circular RC columns under lateral low-velocity impact. To this aim, a total of nine 1/3-scale cantilever columns without axial load, comprising three types of shear-deficient RC columns with different reinforcement layout, were tested in a horizontal collision facility at two different impact velocities. The columns were tested in plain configuration (0 plies) and two wrapped configurations with 2 and 4 plies of CFRP. Generally, for plain columns, brittle shear-type damage was observed. Larger damage was obtained by increasing the impact velocity and decreasing the amount of transverse reinforcements while the variation of the amount of longitudinal steel bars has a negligible effect. The experimental results demonstrate that seismic retrofit using CFRP can provide an effective solution to convert the failure mechanism under lateral impact loading, from shear- to flexural-dominated, with a reduction of the impact damage. This strategy has a beneficial effect given sufficient bending capacity of the plain RC column.
The chewing cycle is a functional movement, closely related to occlusion, the neuromuscular system and the central nervous system. Although actual chewing paths are complicated and vary from ...individual to individual, there are two typical patterns. One is more vertical in nature and is similar to a chopping movement. The other is a more lateral type that is similar to a grinding movement. The purpose of this study was to evaluate the effects of chewing patterns on occlusal wear. Fifteen subjects exhibiting a chopping–chewing pattern and 15 subjects exhibiting a grinding–chewing pattern were selected using a jaw tracking device. The occlusal wear values, obtained by both ordinal and Woda’s arbitrary scales, and frequencies of non‐working facets were calculated for each group. The occlusal wear values in all teeth and in each segment, obtained by the use of the ordinal scale did not vary significantly between the chopping and the grinding type group. However, the occlusal wear values of the grinding type group in all teeth and in posterior teeth segments, obtained by the use of Woda’s arbitrary scale, were significantly greater than those of the chopping type group. Frequencies of non‐working facets in posterior teeth showed no significant differences between the groups.
Background. Ventilator-associated pneumonia (VAP) is a leading cause of morbidity and mortality in patients hospitalized in intensive care units. Recent studies suggest that dental plaque biofilms ...serve as a reservoir for respiratory pathogens. The goal of this study was to determine the genetic relationship between strains of respiratory pathogens first isolated from the oral cavity and later isolated from bronchoalveolar lavage fluid from the same patient undergoing mechanical ventilation with suspected VAP. Methods. Plaque and tracheal secretion samples were obtained on the day of hospital admission and every other day thereafter until discharge from the intensive care unit from 100 patients who underwent mechanical ventilation. Bronchoalveolar lavage was performed for 30 patients with suspected VAP. Pulse-field gel electrophoresis and multilocus sequence typing were used to determine the genetic relatedness of strains obtained from oral, tracheal, and bronchoalveolar lavage samples. Results. Isolates of Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter species, and enteric species recovered from plaque from most patients were indistinguishable from isolates recovered from bronchoalveolar lavage fluid (i.e., had >95% similarity of pulse-field gel electrophoresis patterns). Nearly one-half of the Pseudomonas strains showed identical genetic profiles between patients, which suggested a common environmental source of infection. Conclusions. Respiratory pathogens isolated from the lung are often genetically indistinguishable from strains of the same species isolated from the oral cavity in patients who receive mechanical ventilation who are admitted to the hospital from the community. Thus, dental plaque serves as an important reservoir for respiratory pathogens in patients who undergo mechanical ventilation. Trial registration. ClinicalTrials.gov identifier: NCT00123123
PM2.5 samples were collected at a centrally located urban monitoring site in Seoul, Korea, every third day from March 2003 to December 2006 and analyzed for their chemical constituents. Sources were ...identified using positive matrix factorization (PMF). A total of 393 samples were obtained during the sampling period, and 20 chemical species were measured. Nine PM2.5 source categories were identified providing physically realistic profiles and interesting insights into the source contributions to the ambient mass concentrations. The major contributors of PM2.5 were secondary nitrate (20.9%), secondary sulfate (20.5%), gasoline-fueled vehicles (17.2%), and biomass burning (12.1%), with lesser contributions from diesel emissions (8.1%), soil (7.4%), industry (6.7%), road salt and two-stroke vehicles (5.1%), and aged sea salt (2.2%). PM2.5 levels in Seoul were influenced by both local urban activities and regional-scale transport. Conditional probability function (CPF) results identified possible source directions of local sources such as motor vehicles (gasoline and diesel), industry, and road salt. Potential source contribution function (PSCF) results showed that possible source areas contributing to the elevated secondary particle concentrations (sulfate and nitrate) in Seoul to be the major industrial areas in China.
Objective To evaluate treatment outcomes of in situ abdominal aortic reconstruction with cryopreserved arterial allograft (CAA) for patients with abdominal aortic infection. Materials and methods A ...retrospective review of prospectively collected data was conducted of patients who underwent in situ aortic reconstruction using CAA for primary, secondary, or prosthetic infection of the abdominal aorta between May 2006 and July 2015, at a single institution. Clinical presentation, indications for treatment, procedural details, early post-operative mortality and morbidity, late death, and graft related complications during the follow up period were investigated. Patient survival and event free survival (any death or re-operation) were calculated using the Kaplan-Meier method. Results Twenty-five patients (male, n = 20, 80%; mean age, 70.2 ± 8.7 years) underwent in situ abdominal aortic reconstruction (48% aortic, 52% aorto-bi-iliac) with vessel size and ABO matched CAA for treatment of abdominal aortic infection caused by infected abdominal aortic aneurysm ( n = 15), aortic prosthesis infection ( n = 7), aortic reconstruction with concomitant colon resection ( n = 2), and primary suppurative aortitis ( n = 1). The median follow up was 19.1 months (range 1–73 months). There were seven post-operative deaths including two (8%) early (<30 days) and five (20%) late deaths There were three (12%) graft related complications including thrombotic occlusion of the CAA, aneurysmal dilatation, and aorto-enteric fistula. Three years after CAA implantation, patient survival was 74% and the event free survival was 58%. Conclusions It is believed that in situ abdominal aortic reconstruction with CAA is a useful option for treating primary, secondary, or prosthetic infection of the abdominal aorta.
Risk perception research, targeting the general public, necessitates the study of the multi-faceted aspects of perceived risk through a holistic approach. This study aimed to investigate the ...association between the two dimensions of risk perception of COVID-19, i.e., risk as a feeling and analysis, trust in the current government, political ideologies, and socio-demographic factors in South Korea. This study used a year-long repeated cross-sectional design, in which a national sample (n = 23,018) participated in 23 consecutive telephone surveys from February 2020 to February 2021. Most factors differed in the magnitude and direction of their relationships with the two dimensions of risk perception. However, trust in the current government, alone, delineated an association in the same direction for both dimensions, i.e., those with a lower level of trust exhibited higher levels of cognitive and affective risk perception. Although these results did not change significantly during the one-year observation period, they are related to the political interpretation of risk. This study revealed that affective and cognitive risk perceptions addressed different dimensions of risk perception. These findings could help governments and health authorities better understand the nature and mechanisms of public risk perception when implementing countermeasures and policies in response to the COVID-19 pandemic and other public health emergencies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background and Aims: No information is available on the nature of the correlation between cyclooxygenase‐2 (COX‐2) expression and the clinicopathological features and prognosis of cholangiocarcinoma ...(CC). The goal of the present study was to determine the possible roles and clinical significance of COX‐2 expression in CC.
Methods: We investigated the immunohistochemical expression of COX‐2 in 102 patients with CC with respect to clinicopathological characteristics, namely evidence of Clonorchis sinensis infection, proliferation index (PI, assessed by Ki‐67 expression), apoptotic index (AI, assessed by TUNEL stain), and microvessel density (MVD, assessed by CD34 expression). Evidence of C. sinensis infection was assessed by the microscopic examination of stools for C. sinensis ova, serological testing (ELISA), and the detection of peripheral bile duct dilations by imaging studies.
Results: An immunohistochemical investigation demonstrated the immunolabeling of tumor cells, mainly in the cytoplasmic and perinuclear regions, in 53 (52%) of the 102 patients with CC. No significant differences were found in terms of age, sex, tumor differentiation, involvement of the resection margin, presence of lymph nodes or liver metastases, or in pTNM stage between COX‐2 positive and COX‐2 negative patients. However, evidence of C. sinensis infection was more common in COX‐2 positive patients (P < 0.05). No significant differences were found for PI, AI, MVD, or cumulative survival between COX‐2 positive and COX‐2 negative patients.
Conclusion: Clonorchis sinensis infection is related to aberrant COX‐2 expression in patients with CC. However, COX‐2 expression is not related to clinical outcome in CC patients.
Inflammatory responses and osteoclast differentiation play pivotal roles in the pathogenesis of osteolytic bone diseases such as periodontitis. Although overexpression or inhibition of ...peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (PIN1) offers a possible therapeutic strategy for chronic inflammatory diseases, the role of PIN1 in periodontal disease is unclear. The aim of the present study was to evaluate PIN1 expression in periodontitis patients as well as the effects of PIN1 inhibition by juglone or PIN1 small-interfering RNA (siRNA) and of PIN1 overexpression using a recombinant adenovirus encoding PIN1 (Ad-PIN1) on the inflammatory response and osteoclastic differentiation in lipopolysaccharide (LPS)- and nicotine-stimulated human periodontal ligament cells (PDLCs). PIN1 was up-regulated in chronically inflamed PDLCs from periodontitis patients and in LPS- and nicotine-exposed PDLCs. Inhibition of PIN1 by juglone or knockdown of PIN1 gene expression by siRNA markedly attenuated LPS- and nicotine-stimulated prostaglandin E2 (PGE2) and nitric oxide (NO) production, as well as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, whereas PIN1 overexpression by Ad-PIN1 increased it. LPS- and nicotine-induced nuclear factor (NF)-κB activation was blocked by juglone and PIN1 siRNA but increased by Ad-PIN1. Conditioned medium prepared from LPS- and nicotine-treated PDLCs increased the number of tartrate-resistant acid phosphatase–stained osteoclasts and osteoclast-specific gene expression. These responses were blocked by PIN1 inhibition and silencing but stimulated by Ad-PIN1. Furthermore, juglone and PIN1 siRNA inhibited LPS- and nicotine-induced osteoclastogenic cytokine expression in PDLCs. This study is the first to demonstrate that PIN1 inhibition exhibits anti-inflammatory effects and blocks osteoclastic differentiation in LPS- and nicotine-treated PDLCs. PIN1 inhibition may be a therapeutic strategy for inflammatory osteolysis in periodontal disease.
Summary Objective Cartilage regenerative procedures using the cell-based tissue engineering approach involving mesenchymal stem cells (MSCs) have been receiving increased interest because of their ...potential for altering the progression of osteoarthritis (OA) by repairing cartilage lesions. The aim of this study was to investigate the clinical and magnetic resonance imaging (MRI) outcomes of MSC implantation in OA knees and to determine the association between clinical and MRI outcomes. Design Twenty patients (24 knees) who underwent arthroscopic MSC implantation for cartilage lesions in their OA knees were evaluated at 2 years after surgery. Clinical outcomes were evaluated according to the International Knee Documentation Committee (IKDC) score and the Tegner activity scale, and cartilage repair was assessed according to the MRI Osteoarthritis Knee Score (MOAKS) and Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. Results The clinical outcomes significantly improved ( P < 0.001 for both). The cartilage lesion grades (as described in MOAKS grades for size of cartilage-loss area and percentage of full-thickness cartilage loss) at follow-up MRI were significantly better than the preoperative values ( P < 0.001 for both). The clinical outcomes at final follow-up were significantly correlated with the MOAKS and MOCART score at follow-up MRI ( P < 0.05 for all). Conclusions Considering the encouraging clinical and MRI outcomes obtained and the significant correlations noted between the clinical and MRI outcomes, MSC implantation seems to be useful for repairing cartilage lesions in OA knees. However, a larger sample size and long-term studies are needed to confirm our findings.
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