Search

This paper describes the architecture of a comprehensive seismic monitoring system developed in 2009 by the British Columbia Ministry of Transportation and Infrastructure (MoT) and the University of British Columbia, Canada. The main purpose of the British Columbia Smart Infrastructure Monitoring System project is to instrument and monitor key structures to provide confirmation of their seismic capacity, assist in focusing retrofit efforts, detect structural damage, and provide rapid damage assessment of those structures, following a seismic event. The automatic creation of shakemaps following an earthquake provides information for the MoT's non-instrumented bridges. The public notification systems and web pages have been developed to display real-time seismic data both from the strong motion network and seismic structural health monitoring network. Tools and methods have been developed to help transform the current practice of inspecting and evaluating structures to a more rational and effective one that uses the up-to-date sensing technology with fast and efficient techniques. [ABSTRACT FROM AUTHOR]

Multi-story buildings are usually instrumented at a limited number of floors. Consequently, the structural response (e.g., acceleration, displacement) at the non-instrumented floors remains unknown and needs to be estimated using the acceleration data recorded at the instrumented floors. The prevailing way to estimate the unknown structural response is to interpolate the recorded data over the height of the building. Other methods such as the Mode Shape Based Estimation (MSBE) and Timoshenko Beam Based Estimation (TBBE) methods, on the other hand, use the mode shapes of bending, shear and Timoshenko beam modeling to estimate the unknown structural response. The Factor Building at the UCLA campus in Los Angeles, California, USA is utilized to test the performance of these methods, and the results are compared with conventional interpolation methods (e.g., linear or cubic spline interpolations). The results show clearly that both the MSBE and the TBBE methods provide a better estimation of unknown structural response than both linear interpolation methods. [ABSTRACT FROM AUTHOR]

To identify and calibrate the finite element model for multi-story buildings, a simplifıed approach is being introduced in this paper; this methodology is based on interferometric imaging and encompasses spectral ratio (SR) method. Interferometric imaging provides a new set of seismic data free of coupling between structures to its subsurface and independent of the excitation of the building. The SR method, on the other hand, is the ratio of Fourier amplitude spectra of the roof-deconvolved records on two adjacent stories. The newly introduced methodology enables each story to be identified uniquely for its stiffness since the SR of a particular story is dependent only on the properties of itself and the stories above. [ABSTRACT FROM AUTHOR]

A simple approach is introduced to identify and calibrate analytical models of multi-story buildings from their vibration records. The method is based on the Transfer Matrix formulation of the response, and requires that vibration time histories are known at every floor of the building. Since this is typically not the case, first a methodology is developed to estimate vibration time histories at non-instrumented floors of the building from those recorded at the instrumented floors, based on the assumption that the mode shapes of a multi-story building can be approximated as a linear combination of the mode shapes of a shear beam and a bending beam. Once the vibration time histories are known at every floor, it is shown by using the Transfer Matrix formulation that the top-to-bottom spectral ratio of the records at a particular story is dependent only on the properties of this story and the stories above. In other words, any change in the characteristics of the stories below does not affect the spectral ratio for this story. Therefore, starting from the top story, we can identify frequency of each story (i.e., story stiffness/story mass), or directly story stiffness if the story mass is known. In addition to system identification, the approach also provides a simple tool to calibrate analytical models of multi-story buildings from their vibration records. [ABSTRACT FROM AUTHOR]

The dynamic characteristics of a structure are commonly defined by its modal properties: modal frequencies, damping ratios, and mode shapes. Significant changes in modal properties of a structure after an extreme event, such as an earthquake, or during its service life can be strongly related to damage in the structures. This makes it crucial that the modal properties are accurately estimated and continuously tracked to detect any changes by the structural health monitoring (SHM) system. This paper introduces an algorithm and a MATLAB-based software that includes modules for real-time data processing, modal identification, damage detection, and stakeholder warnings for vibration-based SHM systems. The data processing and modal identification techniques used are based on the classical and stochastic techniques, and utilize running time windows to keep track of time variations in real-time data. The damage detection algorithm makes use of inter-story drifts to detect and locate damage. Since the calculation of inter-story drifts involves double integration and subtraction of acceleration signals, it is extremely hard to get accurate values of inter-story drifts in real-time monitoring. To improve the accuracy, inter-story drifts are calculated for each mode of the structure separately, and then combined synchronously. The displacements at non-instrumented floors are estimated by assuming that the mode shapes can be approximated as a linear combination of those of a shear beam and a bending beam. A software package, REC_MIDS, is developed for this purpose, and it has been operating in a large number of different structures with SHM systems in Turkey (tall buildings, suspension bridges, mosques, museums), and in seven high-rise buildings in UAE. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the variation of the anatomical landmarks at interforaminal region with age and dental status by examining spiral computed tomographies. Fifty young (≤40) and 50 older (>40) patients' interforaminal regions were evaluated with spiral computed tomographic images. In both age groups, 25 of the patients were fully dentate up to mandibular bicuspids contralaterally and the rest were completely edentate at interforaminal region including mandibular bicuspids. The distances between mental foramen to alveolar crest (MF-AC), mental foramen to lower cortex (MF-LC), mental foramen to lingual external border (MF-LEB), mental foramen to contralateral mental foramen (MF-MF), and the height (HMF) and width of MF (WMF) and anterior loop of mental foramen (ML) were measured by an experienced calibrated clinician. In spiral computed tomographic images, MF-AC and MF-LC were significantly lower in edentate subjects being independent of age (p<0.001). WMF and HMF were found significantly smaller in both older and edentate subject groups (p<0.01), MF-MF was significantly longer (p<0.001) in both edentate and older patients, and MF-LEB was not affected by age or dental status (p>0.05). The anatomical landmarks at interforaminal region more likely depend on dental status rather than the age. Safety zone should be 3 mm far from MF for dental implant placement in interforaminal region as the anterior loop of mental foramen was measured as approximately 3 mm. [ABSTRACT FROM AUTHOR]

To investigate the effect of tadalafil on anastomotic healing in an ischemic small intestine. Standardized transection and anastomosis in the small intestine were performed in 48 male Sprague-Dawley rats divided into four equal groups ( n = 12): group 1, normal anastomosis; group 2, ischemic anastomosis; group 3, normal anastomosis+tadalafil treatment; group 4, ischemic anastomosis+tadalafil treatment. Ischemia was established by ligating 2 cm of mesentery on either side of the anastomosis. Tadalafil was given to the rats once a day at dose of 5 mg/kg. The anastomotic bursting pressures and hydroxyproline concentrations were measured on postoperative day 4. A histopathological evaluation of the anastomoses was also performed. The bursting pressure and hydroxyproline concentration in group 2 were significantly lower than those in the other groups. There was no difference in the hydroxyproline concentration among groups 1, 3, and 4. While there was no difference between groups 3 and 4, the bursting pressures were significantly higher in groups 3 and 4 than in group 1. The histopathological evaluation revealed no significant differences in inflammatory cell infiltration, vascularization, or anastomotic collagen deposition among the groups. Tadalafil treatment improved the anastomotic bursting pressure and the hydroxyproline concentration in both normal and ischemic small intestine anastomosis. [ABSTRACT FROM AUTHOR]

Background. There are many experimental studies showing that increased intraabdominal pressure (IAP) reduces liver blood flow, leading to ischemia and portal venous congestion. But, there is no study evaluating the effect of increased IAP on liver regeneration. It is well known that acute liver ischemia and portal venous congestion impair liver regeneration. We, therefore, aimed to determine the effect of increased IAP on liver regeneration in this study.Methods. Sprague–Dawley rats underwent partial hepatectomy with or without IAP of 12–14 mm Hg for 24 h or sham operation. Rats were randomly divided into six groups: two sham-operated groups, two hepatectomy groups, and two hepatectomy with increased IAP groups. Mitotic index, proliferating cell nuclear antigen (PCNA)-labeling index, and liver regeneration rate as liver regeneration parameters were studied on day 1 or on day 4 after operation. Additionally, serum aspartate transaminase (AST) level and histopathological changes in intestinal mucosa were studied.Results. Hepatectomy with/without increased IAP groups had significantly higher serum AST levels than the sham-operated group on day 1. Serum AST level was found to be significantly higher in the hepatectomy with increased IAP group than in the other groups on day 4. Intestinal mucosal injury was found in the hepatectomy with increased IAP groups on days 1 and 4. Mitotic index and PCNA-labeling index were markedly higher in all hepatectomy with/without increased IAP groups than in the sham-operated groups. However, together with liver regeneration rate, both indices were significantly less in the hepatectomy with increased IAP groups than in the hepatectomy groups both on day 1 and on day 4.Conclusion. Maintenance of IAP between 12 and 14 mm Hg for 24 h impaired liver regeneration after partial hepatectomy in rats. [Copyright &y& Elsevier]

Objective: To investigate the effect of increased intra-abdominal pressure followed by abdominal deflation on small intestine with or without previous intestinal ischaemia. Design: Randomised experimental study. Setting: University hospital, Turkey. Animals: 78 male New Zealand white rabbits. Interventions: Experiment 1: 30 rabbits (10 in each group) were subjected to intra-abdominal pressure of 0 mmHg (controls), 15 mmHg or 25 mmHg for 60 minutes. Experiment 2: 48 rabbits were divided into four groups (n = 12 in each). The first comprised sham-operated controls. In the other 3, the superior mesenteric artery was occluded for 60 minutes. Reperfusion was started and maintained under intra-abdominal pressure of 0 mmHg, 15 mmHg, or 25 mmHg for one hour. Intestinal specimens were obtained five and 60 minutes after abdominal deflation in the pressure groups and at identical times in the other groups in both experiments. Main outcome measures: Intestinal malondialdehyde concentration, wet:dry intestinal weight ratio, and mucosal injury score under light microscopy. Results: In experiment 1 the malondialdehyde concentration, wet:dry weight ratio, and mucosal injury scores were higher in the 25 mmHg group than in the other groups in both specimens. There was a significant increase in malondialdehyde concentration in the 15 mmHg group in only the 5-minute specimen. In experiment 2, except for the wet:dry weight ratio in the 5-minute specimen in the 15 mmHg group, there were significant increases in malondialdehyde concentration, wet:dry weight ratio, and mucosal injury score in all groups except controls in both specimens. Malondialdehyde concentration and wet:dry weight ratio were higher in the 25 mmHg group than in the 0 mmHg group in the 60-minute specimen, and higher than the 15 mmHg group in both specimens. Wet:dry weight ratio was less in the 15 mmHg group than the 0 mmHg group in both specimens. Mucosal injury score was higher in the 25 mmHg group than the other groups in both specimens. Conclusion: Increased intra-abdominal pressure for 60 minutes followed by abdominal deflation led to an ischaemiareperfusion-like injury in normal small intestine in rabbits, and added to reperfusion injury in the ischaemic small intestine at an intra-abdominal pressure of 25 mmHg. [ABSTRACT FROM AUTHOR]

Sudden sensorineural hearing loss is a hearing loss of >30 dB in at least three consecutive frequencies that occurs in 3 days. The aim of this study was to investigate anxiety and depression caused by sudden, idiopathic, one-sided hearing loss. The levels of anxiety and depression in patients with this type of hearing loss were determined using the Beck Anxiety Scale (BAS) and the Beck Depression Inventory (BDI) at the time of the patient's first visit. In total, 56 patients (32 men and 24 women) with a mean age of 32.8 ± 9.9 years (range: 20 to 58 years) were selected as the patient group and 45 individuals without symptoms of anxiety and depression were selected as the control group. The mean pretreatment air-conduction threshold and bone-conduction threshold were 61.1 ± 26.1 and 49.4 ± 13.8, respectively. In the patient group, the pretreatment mean anxiety, depression, and hopelessness scores were 19.5 ± 10.7, 11.6 ± 8.4, and 6.2 ± 4.7, respectively. The control group's mean anxiety, depression, and hopelessness scores were 4.1 ± 3.0, 3.8 ± 2.1, and 1.8 ± 1.0, respectively. For all the tests, the difference between the patient group and the control group was statistically significant (p < 0.001 for all). Hearing levels were not correlated with scores on the BAS, BDI, and Beck Hopelessness Scale (p = 0.1, p = 0.6, and p = 0.4, respectively). In conclusion, the results of this study show that sudden hearing loss can cause anxiety and depression. Questioning patients with sudden hearing loss about symptoms associated with anxiety and depression might be useful, and a psychiatric consultation should be requested if necessary. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: It is known that acute pancreatitis may cause secondary changes in several organs. Liver is one of these involved organs. In different experimental studies hepatic damages were shown histopathologically in acute pancreatitis but there are a few studies about perfusion disorders that accompany these histopathologic changes. Perfusion CT (pCT) provides the ability to detect regional and global alterations in organ blood flow. The purpose of the study was to describe hepatic perfusion changes in experimental acute pancreatitis model with pCT. Materials and methods: Forty Sprague–Dawley rats of both genders with average weights of 250g were used. Rats were randomized into two groups. Twenty rats were in control group and 20 in acute pancreatitis group. pCT was performed. Perfusion maps were formed by processing the obtained images with perfusion CT software. Blood flow (BF) and blood volume (BV) values were obtained from these maps. All pancreatic and liver tissues were taken off with laparotomy and histopathologic investigation was performed. Student''s t test was used for statistical analyses. Results: In pCT we found statistically significant increase in blood volume in both lobes of liver and in blood flow in right lobe of the liver (p <0.01). Although blood flow in left lobe of the liver increased, it did not reach statistical significance. Conclusion: The quantitative analysis of liver parenchyma with pCT showed that acute pancreatitis causes a significant perfusion changes in the hepatic tissue. Systemic mediators seem to be effective as well as local inflammatory changes in perfusion changes. [Copyright &y& Elsevier]

Abstract: Background: Many therapeutic strategies have been proposed to treat liver fibrosis, but no drugs have been proved effective. Matrix metalloproteinases (MMPs) have been reported to play a role in some cellular cascades of hepatic inflammation and fibrosis. Objective: The purpose of this study was to investigate whether silymarin and pentoxifylline (PTX) have hepatoprotective and antifibrotic effects in experimental hepatic fibrosis. Methods: Sprague-Dawley rats were divided into 4 groups: silymarin group (silymarin 4 mg/kg · d−1 orally, common bile duct ligation [CBDL]); PTX group (PTX 2 mg/kg · d−1 intraperitoneally, CBDL); sham group (common bile duct [CBD] exploration only); and control group (saline 1 mL/d orally, CBDL). The CBD was explored and dissected sufficiently to allow passage of a 3/0 silk suture via midline laparotomy. On day 10, all animals were euthanized via cervical dislocation. Then, 5-cm3 liver samples from the right lobe were removed for histomorphologic evaluation and 3-mL blood samples were taken via cardiac puncture for biochemical analyses. Apoptosis was determined using the terminal deoxynucleotidyltransferase-biotin nick end-label (TUNEL) staining method. Plasma levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyltransferase; total and indirect bilirubin concentration; hepatic MMP-1 and -2 and tissue inhibitor of MMP (TIMP)-l and -2 activity; and transforming-growth factor (TGF)-β1 concentration were measured. Collagen content was determined by measuring hydroxyproline in liver samples. Malondialdehyde (MDA) was used to estimate lipid peroxidation. Results: Thirty-two adult male Sprague-Dawley rats were divided into 4 groups: silymarin group (n = 7), PTX group (n = 7), sham group (n = 9), and control group (n = 9). Compared with the control group (14.6 [2.44]), mean (SD) hepatocyte apoptosis (as measured by the ratio of TUNEL-positive cells) was significantly suppressed in the silymarin group (1.2 [0.13]; P = 0.001) and the PTX group (3.8 [0.34]; P = 0.001). Mean (SD) MMP-2 activity in the silymarin group (57.35 [9.89] μg/mL; P = 0.04) and the PTX group (46.88 [9.56] μg/mL; P = 0.04) was significantly lower than that observed in the control group (232.32 [79.76] μg/mL). Compared with the control group (1.37 [0.38] μg/mL), TIMP-2 activity was significantly lower in the silymarin group (0.55 [0.13] μg/mL; P = 0.04) and the PTX group (0.42 [0.09] μg/mL; P = 0.01). Compared with the control group (909.17 [117.35] μg/mL), TGF-β1 was significantly lower in the silymarin group (518.24 [30.34] μg/mL; P = 0.01) and the PTX group (519.57 [47.27] μg/mL; P = 0.01). Histomorphologic changes were significantly greater in the sham group than in the silymarin and PTX groups: hemorrhage (2.44 [0.29] vs 1.29 [0.18] and 1.57 [0.20], respectively; both, P = 0.04); sinusoidal dilatation (2.22 [0.22] vs 1.57 [0.20] and 1.71 [0.18]; both, P = 0.04); presinusoidal polymorphonuclear cell infiltration (3-44 [0.24] vs 2.57 [0.20] and 2.14 [0.26]; P = 0.03 and P = 0.008, respectively); and inflammation (3.44 [0.24] vs 2.57 [0.20] and 2.14 [0.26]; P = 0.03 and P = 0.008, respectively). In the control group, all biochemical markers were elevated, supporting the presence of liver injury. Compared with the control group (630.00 [46.80] U/L), plasma AST activity was significantly lower in the silymarin group (443.11 [78.73]; P = 0.04) and the PTX group (349.42 [34.00]; P = 0.03). Compared with the control group (191.12 [32.93] U/L), plasma ALT activity was significantly lower in the silymarin group (86.14 [4.97]; P = 0.04) and the PTX group (84.14 [11.21]; P = 0.04). MDA concentration was significantly lower in the silymarin group compared with the control group (0.08 [0.01] vs 0.22 [0.03] nmol/mL; P = 0.004); MDA was also significantly lower in the silymarin group than in the PTX group (0.11 [0.02]; P = 0.03). Conclusions: Silymarin and PTX were associated with lower histopathologic liver damage, hepatocyte apoptosis, and regulation of extracellular matrix proteins. Lipid peroxidation in hepatocytes was significantly lower in the silymarin group compared with the PTX group. Silymarin and PTX appeared to have hepatoprotective effects in this experimental liver fibrosis model, but further clinical and experimental studies are needed. [Copyright &y& Elsevier]

Dental avulsion is a common and complex injury which affects multiple oral tissues. In this case report, a 9-year-old girl patient with two traumatically avulsed maxillary central incisors with loss of periodontal tissue was presented. Treatment guidelines for avulsed permanent teeth with open apex were carried out. Bilateral laterally sliding flap procedure was performed, to repair loss of gingival soft tissue. Conventional immobilization was carried out for 6 weeks. Five months follow-up of the patient in whom replantation was performed resulted in positive sensitivity test, no symptoms of infection, pain or any discomfort and good periodontal wound healing. In conclusion, this report presents successful replantation and periodontal treatment of a patient with complex dentoalveolar injury. [ABSTRACT FROM AUTHOR]

Adipose tissue-derived hormones (adipocytokines), such as adiponectin, leptin, resistin and visfatin, and the pancreatic hormone insulin, have been suggested to play a role in carcinogenesis. We therefore hypothesized that the oncological treatment of breast cancer may alter the serum levels of these adipocytokines and insulin. In this study, we aimed to compare the serum levels of adipocytokines and insulin between the pre- and post-treatment period in patients with breast cancer. In this prospective study, 20 consecutive patients with stage II and III breast cancer underwent breast-conserving surgery or total mastectomy and/or axillary dissection. The patients received adjuvant chemotherapy and radiotherapy, if necessary. Blood samples were obtained during the preoperative period and postoperatively after completion of the adjuvant therapy. There was no statistically significant difference between the pre- and post-treatment levels of visfatin, adiponectin and leptin. However, the serum insulin and resistin levels and insulin resistance were found to be statistically significantly increased following treatment (P<0.05). Post-treatment resistin levels were positively correlated with insulin resistance (r=0.45, P<0.05). Therefore, oncological treatment of stage II and III breast cancer did not affect visfatin, adiponectin and leptin levels, but statistically significantly increased resistin levels and insulin resistance. In addition, the post-treatment resistin levels were positively correlated with insulin resistance, suggesting that resistin may be involved in the development of insulin resistance in breast cancer patients following treatment. [ABSTRACT FROM AUTHOR]

Sepsis remains a difficult problem for clinicians, with its systemic effects and high morbidity and mortality rates. The roles of oxidative stress, endothelial dysfunction, and lipid peroxidation in sepsis-induced organ damage are being investigated.The aim of this study was to investigate the effects of selective cyclooxygenase (COX)-2 inhibition on tissue lipid peroxidation, endothelial dysfunction, and hepatic cell morphology in a rat model of sepsis.Thirty rats with sepsis induced by cecal ligation and puncture were divided equally into 3 groups: treatment group (rofecoxib 1 mg/kg PO), control group (saline 1 mL PO), and sham group (sham surgery only). All the rats were sacrificed 1 day after sepsis induction. The livers were removed using a median laparotomy for histopathologic and biochemical analysis.Histomorphologic hepatic damage and lipid peroxidation were significantly reduced in the rofecoxib treatment group compared with the control group (P < 0.05 and P = 0.001, respectively). Endothelial nitric oxide synthase and inducible nitric oxide synthase staining of liver samples was statistically significantly reduced in the treatment group compared with the control group (both, P < 0.001). The hepatic nitric oxide level and malonyldialdehyde activity decreased significantly (P < 0.001 and P = 0.001, respectively) in the rofecoxib group compared with the control group. Hepatic myeloperoxidase activity was similar between the treatment and control groups.Further investigation of selective COX-2 inhibition as an alternate therapeutic choice for sepsis-induced hepatic damage should be considered. [Copyright &y& Elsevier]

• A deflection-based method for damage diagnosis in buildings is proposed. • The deflections are estimated from identified modal flexibility matrices. • The method is applicable for plan-symmetric buildings with asymmetric damage. • The method can be used for damage detection, localization and quantification. • The proposed method extends an existing method developed for planar structures. Effective methods for vibration-based damage diagnosis in building structures are based on the estimation of structural deflections from identified modal flexibility (MF) matrices. However, most of the existing methods and previous studies that use MF-based deflections were developed by considering the case of buildings that can be modeled as planar structures (e.g. plan-symmetric buildings) both in the baseline and possibly damaged states. In an attempt to fill this research gap, a deflection-based method for output-only damage diagnosis in building structures tested under ambient vibrations is proposed in this paper. The method is applicable for simple rectangular plan-symmetric "box type" 3D building structures which may experience asymmetric damage, and it can be used for detecting, localizing and quantifying the damage. One of the main differences between the proposed and the existing methods is related to the inspection loads adopted to estimate the MF-based deflections. The inspection loads of the proposed method are more complex than the uniform translational loads adopted in the existing methods. Such proposed loads in fact can be assembled only after having estimated the position of the center of stiffness for each story of the structure. According to the proposed approach, the locations of the centers of stiffness are extracted from the experimentally-derived modal flexibility matrices, before performing the damage diagnosis process. The effectiveness and validity of the proposed method was demonstrated both through numerical analyses and by executing experimental ambient vibration tests on a frame building. The results of the proposed method were also compared with the existing approach which was developed for planar structures. This comparison (made both through numerical and experimental analyses) demonstrated that only the proposed approach can be used to perform a correct damage diagnosis process in plan-symmetric buildings which may experience asymmetric damage, especially when considering the damage quantification problem. [ABSTRACT FROM AUTHOR]