Rheological Behavior of High-Performance Shotcrete Mixtures Containing Colloidal Silica and Silica Fume Using the Bingham Model.

There have been numerous studies on shotcrete based on strength and durability. However, few studies have been conducted on rheological characteristics, which are very important parameters for evaluating the pumpability and shootability of shotcrete. In those studies, silica fume has been generally used as a mineral admixture to simultaneously enhance the strength, durability, pumpability, and shootability of shotcrete. Silica fume is well-known to significantly increase the viscosity of a mixture and to prevent material sliding at the receiving surface when used in shotcrete mixtures. However, the use of silica fume in shotcrete increases the possibility of plastic shrinkage cracking owing to its very high fineness, and further, silica fume increases the cost of manufacturing the shotcrete mixture because of its cost and handling. Colloidal silica is a new material in which nano-silica is dispersed in water, and it could solve the above-mentioned problems. The purpose of this research is to develop high-performance shotcrete with appropriate levels of strength and workability as well as use colloidal silica for normal structures without a tunnel structure. Thereafter, the workability of shotcrete with colloidal silica (2, 3, and 4%) was evaluated with a particle size of 10 nm and silica fume replacement (4 and 7%) of cement. In this study, an air-entraining agent for producing high-performance shotcrete was also used. The rheological properties of fresh shotcrete mixtures were estimated using an ICAR rheometer and the measured rheological parameters such as flow resistance and torque viscosity were correlated with the workability and shootability. More appropriate results will be focusing on the Bingham model properties such that the main focus here is to compare all data using the Bingham model and its performance. The pumpability, shootability, and build-up thickness characteristics were also evaluated for the performance of the shotcrete. This research mainly focuses on the Bingham model for absolute value because it creates an exact linear line in a graphical analysis, which provides more appropriate results for measuring the shotcrete performance rather than ICAR rheometer relative data.

Erratum: Field Cancerization in Sporadic Colon Cancer.

In the version of this article initially published, the first affiliation (affiliation number 1) was incorrectly stated as "Division of Gastroentorology, Department of Internal Medicine." The correct affiliation is "Department of Internal Medicine."

Field Cancerization in Sporadic Colon Cancer.

BACKGROUND/AIMS: Aberrant DNA methylation has a specific role in field cancerization. Certain molecular markers, including secreted frizzled-related protein 2 (SFRP2), tissue factor pathway inhibitor 2 (TFPI2 ), N-Myc downstream-regulated gene 4 (NDRG4) and bone morphogenic protein 3 (BMP3), have previously been shown to be hypermethylated in colorectal cancer (CRC). We aim to examine field cancerization in CRC based on the presence of aberrant DNA methylation in normal-appearing tissue from CRC patients. METHODS: We investigated promoter methylation in 34 CRC patients and five individuals with normal colonoscopy results. CRC patients were divided into three tissue groups: tumor tissue, adjacent and nonadjacent normal-appearing tissue. The methylation status (positive: methylation level >20%) of SFRP2 , TFPI2 , NDRG4 , and BMP3 promoters was investigated using methylation-specific PCR. RESULTS: The methylation frequencies of the SFRP2 , TFPI2 , NDRG4 and BMP3 promoters in tumor/adjacent/nonadjacent normal-appearing tissue were 79.4%/63.0%/70.4%, 82.4%/53.6%/60.7%, 76.5%/61.5%/69.2%, 41.2%/35.7%/50.0%, respectively. The methylation levels of the SFRP, TFPI2, NDRG4 and BMP3 promoters in tumor tissues were significantly higher than those in normal-appearing tissue (SFRP2, p=0.013; TFPI2, p<0.001; NDRG4, p=0.003; BMP3, p=0.001). No significant correlation was observed between the methylation levels of the promoters and the clinicopathological variables. CONCLUSIONS: The field effect is present in CRC and affects both the adjacent and nonadjacent normal-appearing mucosa.

Seasonal variation in months of birth and symptom flares in Korean patients with inflammatory bowel disease.

BACKGROUND/AIMS: Seasonal variation may influence the development and exacerbation of inflammatory bowel disease (IBD). However, most epidemiologic studies on this topic have been conducted in Western countries. The purpose of this study was to determine whether birth dates and symptom flares follow a seasonal pattern in Korean patients with IBD. METHODS: Patients with a diagnosis of IBD established between January 2003 and December 2010 were investigated at six university hospitals in Korea. The expected births and flares, with a uniform distribution during the year and considering differences in the number of days in the months of 1 year, were calculated. RESULTS: A total of 411 patients with ulcerative colitis (UC) and 316 patients with Crohn disease (CD) were included in the study. Birth during the winter period, and especially in January and February, was associated with an increased risk of IBD, especially in UC patients. The symptom flares of CD patients occurred most frequently in the spring, with a nadir in the autumn. However, no disease flare seasonality was noted for UC patients. CONCLUSIONS: Our data suggest that seasonally varying environmental factors during pregnancy and the postpartum period are associated with a susceptibility to IBD later in life and that exacerbations of CD are influenced by seasonal factors.

A clear liquid diet is not mandatory for polyethylene glycol-based bowel preparation for afternoon colonoscopy in healthy outpatients.

BACKGROUND/AIMS: A dietary regimen consisting of a clear liquid diet (CLD) for at least 24 hours is recommended for colonoscopy preparation. However, this requirement results in problems in patient compliance with bowel preparation. The aim of this study was to evaluate the efficacy of a CLD compared with a regular diet (RD) for colonoscopy preparation using a polyethylene glycol (PEG) solution. METHODS: This was a multicenter, randomized, investigator-blind prospective study. A total of 801 healthy outpatients undergoing afternoon colonoscopy were randomized to either a CLD or RD in addition to a 4 L PEG regimen. RESULTS: The quality of bowel cleansing was not different between the CLD and RD groups in terms of the proportion with excellent or good preparation. In addition, no significant differences were observed between the two groups for polyp and adenoma detection rates and overall adverse events. Good compliance with bowel preparation was higher in the RD group than in the CLD group. CONCLUSIONS: A CLD for a full day prior to colonoscopy should not be mandatory for PEG-based bowel preparation. Dietary education concerning the avoidance of high-fiber foods for 3 days before colonoscopy is sufficient, at least for healthy outpatients.

Enhanced A-FABP expression in visceral fat: potential contributor to the progression of NASH.

BACKGROUND/AIMS: Adipose tissue is an active endocrine organ that secretes various metabolically important substances including adipokines, which represent a link between insulin resistance and nonalcoholic steatohepatitis (NASH). The factors responsible for the progression from simple steatosis to steatohepatitis remain elusive, but adipokine imbalance may play a pivotal role. We evaluated the expressions of adipokines such as visfatin, adipocyte-fatty-acid-binding protein (A-FABP), and retinol-binding protein-4 (RBP-4) in serum and tissue. The aim was to discover whether these adipokines are potential predictors of NASH. METHODS: Polymerase chain reaction, quantification of mRNA, and Western blots encoding A-FABP, RBP-4, and visfatin were used to study tissue samples from the liver, and visceral and subcutaneous adipose tissue. The tissue samples were from biopsy specimens obtained from patients with proven NASH who were undergoing laparoscopic cholecystectomy due to gallbladder polyps. RESULTS: PATIENTS WERE CLASSIFIED INTO TWO GROUPS: NASH, n=10 and non-NASH, n=20 according to their nonalcoholic fatty liver disease Activity Score. Although serum A-FABP levels did not differ between the two groups, the expressions of A-FABP mRNA and protein in the visceral adipose tissue were significantly higher in NASH group than in non-NASH group (104.34 vs. 97.05, P<0.05, and 190.01 vs. 95.15, P<0.01, respectively). Furthermore, the A-FABP protein expression ratio between visceral adipose tissue and liver was higher in NASH group than in non-NASH group (4.38 vs. 1.64, P<0.05). CONCLUSIONS: NASH patients had higher levels of A-FABP expression in their visceral fat compared to non-NASH patients. This differential A-FABP expression may predispose patients to the progressive form of NASH.

Association between red cell distribution width and disease activity in patients with inflammatory bowel disease.

BACKGROUND: Recent studies have suggested that a higher red blood cell distribution width (RDW) is associated with disease activity in patients with inflammatory bowel disease (IBD). However, the RDW in IBD patients without anemia has not been investigated. AIM: This study aimed to determine whether or not RDW could be used for the assessment of disease activity in IBD patients with and without anemia. METHODS: The serum C-reactive protein (CRP) level, erythrocyte sedimentation rate (ESR), hemoglobin concentration, platelet and white blood cell counts, and RDW were assessed in 221 IBD patients, comprised of 120 patients with ulcerative colitis (UC) and 101 patients with Crohn's disease (CD). Disease activity was determined for UC and CD with the Mayo score and the Crohn's disease activity index, respectively. RESULTS: The CRP level, ESR, hemoglobin concentration, hematocrit, and RDW increased according to disease activity in patients with and without anemia (all P < 0.05). Multivariate analysis demonstrated that RDW was the best independent indicator for predicting disease activity in CD patients without anemia [odd ratios (OR), 1.702; 95% confidence interval (CI), 1.185-2.445; P = 0.004] and UC patients without anemia (OR, 4.921; 95% CI, 2.281-10.615; P < 0.001). Also, ROC curve analysis showed the RDW to be the most significant indicator of non-anemic active IBD [area under curve (AUC) in CD, 0.852, P < 0.001; AUC in UC, 0.827, P < 0.001]. CONCLUSION: The association between increased RDW and active IBD was evident in IBD patients with and without anemia.

[Usefulness of model for end-stage liver disease score for predicting mortality after intra-abdominal surgery in patients with liver cirrhosis in a single hospital].

BACKGROUND/AIMS: Recent studies have suggested that the model for end-stage liver disease (MELD) score is superior to the Child-Turcotte-Pugh (CTP) score as a predictor of postoperative mortality, especially up to 90 days. This study aimed to determine whether MELD score can predict the postoperative outcome of patients with liver cirrhosis in Korea. METHODS: We reviewed the medical records of 98 patients with liver cirrhosis who underwent intra-abdominal surgery under generalized anesthesia between March 2003 and December 2008 at Kangbuk Samsung Hospital. Univariate and multivariate cox proportional hazards analyses were performed to determine the correlation between risk factors and mortality. RESULTS: Eighty-two percent of patients (n=80) were male. Mean MELD score was 10.82 ± 3.84. Common causes of liver cirrhosis were hepatitis B (57.2%) and alcohol (22.4%). Ninety-day mortality ranged from 2.1% (MELD score, ≤ 9) to 25% (MELD score, ≥ 17). By multivariate analysis, MELD score > 9 (HR 2.490; [95% CI 1.116-5.554; p=.026]) and American Society of Anesthesiologists Class ≥ IV (HR 2.433; [95% CI 1.039-5.695; p=.041]) predicted mortality at 30 days after surgery. Only MELD score was a predictor of prognosis at 90 days (HR 2.446; [95% CI 1.118-5.352; p=.025]). Etiology of cirrhosis and CTP score were not predictors of mortality. CONCLUSIONS: MELD score was a useful predictive parameter of postoperative mortality at 30 days and 90 days, independent of the etiology of cirrhosis.

Prediction of mortality in patients undergoing maintenance hemodialysis by Charlson Comorbidity Index using ICD-10 database.

BACKGROUND/AIMS: Many patients with end-stage renal disease have additional comorbidities that are important to clinical study and impact the patient's outcome. The Charlson Comorbidity Index (CCI) is a popular tool and a strong predictor of outcome in end-stage renal disease patients. We obtained comorbidity data from the hospital discharge database using the International Classification of Disease, 10th revision (ICD-10) and analyzed the mortality rate in incident patients undergoing maintenance hemodialysis (HD). METHODS: We evaluated the medical records of a total of 456 patients on HD (58 ± 14 years of age, 56% males). We calculated CCI scores at the start of HD with information from the hospital discharge summary according to the ICD-10 code. We then analyzed patient mortality according to these CCI scores. RESULTS: The percentages of patients that had diabetes with end-organ damage (51.1%), congestive heart failure (9.9%), coronary artery disease (8.1%) and stroke (6.8%) were identified. CCI scores were 5.09 ± 2.01 (range 2-11). Four comorbidity groups were established by quartile ranking of the CCI scores: low, moderate, high and very high. The mortality rates were: 0.83, 7.70, 14.09 and 18.69 deaths/100 patient-years, respectively (p = 0.001). Compared with the low comorbidity group, the hazard ratios for mortality were 9.22 (95% CI 3.29-25.84) for the moderate group, 16.77 (95% CI 5.97-47.11) for the high group, and 22.37 (95% CI 8.08-61.93) for the very high group. CONCLUSIONS: The CCI scores using the ICD-10 database information were significant predictors of mortality in incident patients undergoing maintenance HD.

A case of metachronous metastasis to the breast from non-small cell lung carcinoma.

Breast metastases from an extramammary primary tumor are very rare and the prognosis for such patients is generally poor. We report here on a case of a 42-year-old female with metastasis of non-small cell lung cancer to the breast, and she is now being followed up on an outpatient basis. In 2004, she presented with a solitary pulmonary nodule in the left lung, and this lesion had been noted to have gradually increased in size over time. The final pathological diagnosis was adenocarcinoma, and the diagnosis was made by performing percutaneous needle aspiration and lobectomy of the left upper lobe. Adjuvant chemotherapy and radiotherapy were given. Unfortunately, a nodule in the left breast was noted three years later, and metastatic non-small-cell lung cancer to the breast was diagnosed by excisional biopsy. Making the correct diagnosis to distinguish a primary breast carcinoma from a metastatic one is important, because the therapeutic plan and outcome for these two types of cancer are quite different.