Hyun Hee Chung

A High Performance Co-design of 26 nm 64 Gb MLC NAND Flash Memory using the Dedicated NAND Flash Controller

It is progressing as new advents and remarkable developments of mobile device every year. On the upper line reason, NAND FLASH large density memory demands which can be stored into portable devices have been dramatically increasing. Therefore, the cell size of the NAND Flash memory has been scaled down by merely 50% and has been doubling density each per year. [1] However, side effects have arisen the cell distribution and reliability characteristics related to coupling interference, channel disturbance, floating gate electron retention, write-erase cycling owing to shrinking around 20㎚ technology. Also, FLASH controller to manage shrink effect leads to speed and current issues. In this paper, It will be introduced to solve cycling, retention and fail bit problems of sub-deep micron shrink such as Virtual negative read used in moving read, randomization. The characteristics of retention, cycling and program performance have 3 K per 1 year and 12.7 MB/s respectively. And device size is 179.32 ㎟ (16.79 ㎜ × 10.68 ㎜) in 3 metal 26 ㎚ CMOS.

Stability of Isoflavone Daidzein and Genistein in Riboflavin, Chlorophyll b, or Methylene Blue Photosensitization

Effects of photosensitizers including riboflavin, chlorophyll b, or methylene blue on the stability of daidzein and genistein were studied in model systems by high-performance liquid chromatography (HPLC). Concentration of daidzein and genistein in 80% methanol with riboflavin under light for 7 h was significantly decreased with the apparent 1st-order rate constants of 0.234 and 0.193/h, respectively, (P < 0.05), while those without riboflavin under light did not change significantly (P > 0.05). The stability of isoflavone aglycones in the dark did not change significantly irrespective of the presence of riboflavin (P > 0.05). The concentrations of daidzein and genistein in chlorophyll b or methylene blue model systems under light were not significantly different from those in the dark for 7 h (P > 0.05). Addition of sodium azide increased the stability of daidzein and genistein in riboflavin photosensitization with concentration dependent manner. However, the protective effects of beta-carotene addition on the photodegradation of isoflavones were not high. The stability difference of daidzein and genistein in riboflavin photosensitization may be due to the high reactivity of riboflavin through type I pathway, although singlet oxygen may be involved in part.

Comparison of scoring systems in predicting the severity of acute pancreatitis

AIM To investigate the prognostic usefulness of several existing scoring systems in predicting the severity of acute pancreatitis (AP). METHODS We retrospectively analyzed the prospectively collected clinical database from consecutive patients with AP in our institution between January 2011 and December 2012. Ranson, Acute Physiology and Chronic Health Evaluation (APACHE)-II, and bedside index for severity in acute pancreatitis (BISAP) scores, and computed tomography severity index (CTSI) of all patients were calculated. Serum C-reactive protein (CRP) levels were measured at admission (CRPi) and after 24 h (CRP24). Severe AP was defined as persistent organ failure for more than 48 h. The predictive accuracy of each scoring system was measured by the area under the receiver-operating curve (AUC). RESULTS Of 161 patients, 21 (13%) were classified as severe AP, and 3 (1.9%) died. Statistically significant cutoff values for prediction of severe AP were Ranson≥3, BISAP≥2, APACHE-II≥8, CTSI≥3, and CRP24≥21.4. AUCs for Ranson, BISAP, APACHE-II, CTSI, and CRP24 in predicting severe AP were 0.69 (95%CI: 0.62-0.76), 0.74 (95%CI: 0.66-0.80), 0.78 (95%CI: 0.70-0.84), 0.69 (95%CI: 0.61-0.76), and 0.68 (95%CI: 0.57-0.78), respectively. APACHE-II demonstrated the highest accuracy for prediction of severe AP, however, no statistically significant pairwise differences were observed between APACHE-II and the other scoring systems, including CRP24. CONCLUSION Various scoring systems showed similar predictive accuracy for severity of AP. Unique models are needed in order to achieve further improvement of prognostic accuracy.

The Relationship between Metformin and Cancer in Patients with Type 2 Diabetes

Background Recently, several studies reported that the cancer incidence in type 2 diabetes patients is higher than in the general population. Although a number of risks are shared between cancer and diabetes patients, there have been few studies of its correlation. We evaluated the influences of several factors including low density lipoprotein cholesterol (LDL-C), albuminuria and use of metformin on the risk of cancer in patients with type 2 diabetes. Methods We enrolled 1,320 patients with at least 5 years of follow-up and 73 patients were diagnosed with cancer during this period. The associations of the risk factors with cancer incidence were evaluated by multiple regression analysis. The subjects were placed into two subgroups based on metformin dosage (<1,000 mg/day, ≥1,000 mg/day) and we compared cancer incidence using analysis of covariance. Results LDL-C and albuminuria were not significantly correlated with cancer risk. In contrast, metformin showed a reverse correlation with cancer risk (P=0.006; relative risk, 0.574). In the metformin nonadministration group, smoking, male gender, and high triglyceride levels tended to be contributing factors without statistical significance. Cancer occurence was lower in the low dose metformin group (less than 1,000 mg/day) (P=0.00). Conclusion These results suggest that the administration of low dose metformin in patients with type 2 diabetes may be associated with a reduced risk of cancer.

Su1242 Clinical Significance of Colonoscopic Examination in Patients With Early Gastric Cancer

Background/Aims;In patients with gastric cancer, colorectal cancer is one of themost common synchronous cancers.Recently, preoperative colonoscopy for patients with gastric adenocarcinoma has been recommended. We aimed to assess the clinical value of colonoscopy by evaluating the frequency of colorectal neoplasm in patients with early gastric cancer(EGC) compared to healthy controls and analyzed the risk factors of advanced colorectal neoplasm in patients with EGC. Methods; The medical records of 203 patients who diagnosed as EGC and 201 healthy control matched sex and age were reviewed retrospectively. All of the subjects underwent colonoscopy for routine check-up. The frequency and clinical feature of the colorectal polyp were assessed and compared with control group. Risk factors of advanced colorectal neoplasm(high grade dysplasia, size ≥1cm, with villous component, carcinoma in situ and intramucosal cancer) in EGC were also analyzed. Results;Mean age of the patients was 61±10.3 years and 72.3% of the patients were male. The triglyceride level was significantly higher in EGC subgroup and BMI was higher in control group (P<0.05). The frequency of overall colorectal polyp was 62.6 % in the EGC group and 54.2% in the control group (p = 0.09). There was no significant difference in number of the polyps per patients between groups. However, the colorectal polyps in patients with EGC were located at right colon more frequently than in the control group(p<0.05). Advanced colorectal neoplasms were found in 10.3% of patients with EGC and 3% of controls (p <0.05). Colorectal cancers were found in 6 patients(4.6%) with EGC . By univariate analysis, patients with advanced colorectal neoplasm in EGC group were older than those with non-advanced neoplasm (66.9±12.4 vs 61.7±10.0, p=0.04). Multivariate analysis showed that the risk factors for advanced colorectal neoplasms in patients with EGC were old age and smoking. Conclusion: Although there was no significant difference in the frequency of overall colorectal polyp, the prevalence of coexisting advanced colorectal neoplasm was higher in patients with EGC than in normal population. Preoperative colonoscopy is strongly indicated in patients with EGC who are old age or smoker The present study showed that colonoscopy