Interpretable Deep Learning Model for Analyzing the Relationship between the Electronic Structure and Chemisorption Property.

The use of machine learning (ML) is exploding in materials science as a result of its high predictive performance of material properties. Tremendous trainable parameters are required to build an outperforming predictive model, which makes it impossible to retrace how the model predicts well. However, it is necessary to develop a ML model that can extract human-understandable knowledge while maintaining performance for a universal application to materials science. In this study, we developed a deep learning model that can interpret the correlation between surface electronic density of states (DOSs) of materials and their chemisorption property using the attention mechanism that provides which part of DOS is important to predict adsorption energies. The developed model constructs the well-known d-band center theory without any prior knowledge. This work shows that human-interpretable knowledge can be extracted from complex ML models.

[The seroprevalence rate, vaccination rate and seroconversion rate of hepatitis A in central region of Korea].

BACKGROUND/AIMS: Acute hepatitis A (HAV) is markedly increasing recently on. Some patients with acute hepatitis A show severe clinical course. The seroprevalence rate of IgG anti-HAV has been changing with the regions and the times. Vaccination and seroconversion rate of HAV are not well known. In this study, we aimed to study the difference of seroprevalence rate of IgG anti-HAV according to various clinical factors and to know the vaccination rate and seroconversion rate below 10 years old in the central region of South Korea including Cheonan city. METHODS: Seven hundred seventy two subjects were included in the study from January to September 2009. We analyzed seroprevalence rate of IgG anti-HAV according to sex, age, region, and other viral markers. We interviewed the history of vaccination(1st, 2nd) and analyzed seroconversion rate according to vaccination time below 10 years old. RESULTS: The total seroprevalence rate of IgG anti-HAV was 65.3%. The seroprevalence rate of IgG anti-HAV rate in 2nd, 3rd, and 4th decade was very low (1.9%, 18.8%, 44.8%). The vaccination rate of children was about 50%. The seroconversion rate after 1st, and 2nd vaccination were 85%, 96%. CONCLUSIONS: Catch-up vaccination for teenagers and young adults is needed. Immunizing children with HAV vaccine as a routine schedule should be considered.

Phlebosclerotic colitis in a cirrhotic patient with portal hypertension: the first case in Korea.

Phlebosclerotic colitis is a rare form of ischemic colitis characterized by the thickening of the wall of the affected colon due to fibrous degeneration of submucosal layer of colon and fibrotic obstruction of the colono-mesenteric vein, resulting in the disturbance of venous return from the colon. The pathogenic mechanism of this entity remains unknown but chronic liver disease with portal hypertension is maybe thought to be one of the speculated mechanisms. Here we first report the case of surgically confirmed phlebosclerotic colitis, that was in the early stage but showed the aggressive nature, in a 61-yr-old cirrhotic patients with portal hypertension in Korea.

[Clinical, radiological and pathological exploration of focal nodular hyperplasia of liver reported in Korea].

BACKGROUND/AIMS: Focal nodular hyperplasia (FNH) is mandatory to be differentiated from other hepatic tumorous conditions such as hepatocellular carcinoma and adenoma. The purpose of this study was to explore the clinical, radiological and pathological features of FNH cases reported in Korea. METHODS: We have searched the journals from the web site "http://koreamed.org" using keywords "focal nodular hyperplasia" and "liver" - total of 38 cases of FNH, 37 cases from 17 published articles and one case from our experience confirmed histologically, were reviewed and analyzed. RESULTS: Thirty eight cases were diagnosed between gestational age of 36 weeks and 67 years. Seventeen female patients (45%) had no history of taking oral contraceptives. Twenty cases (52.6%) experienced clinical symptoms such as abdominal pain and palpable mass. Computed tomography revealed contrast-enhancement in 34 nodules (85%) and typical central stellate scar in 9 (22.5%) of 40 nodules. Magnetic resonance imaging showed T1 weighted low signal in 18 (60%) and T2 weighted high signal in 22 (73.3%) of 30 nodules. Six (60%) of 10 cases showed hypervascular staining on hepatic angiography. Among 38 cases, 32 (84.2%) cases had single nodule and their mean size was 3.9 cm (0.5-16 cm). Pathologically, fibrous septa, proliferation of bile ductules and arterial wall thickening were seen in most cases. CONCLUSIONS: Of all the FNH cases reported in Korea, there were some differences in clinical aspects of sex ratio, accompanying clinical symptoms, and relationship with oral contraceptives, compared with previous reports. Further prospective studies are needed by means of nation-wide clinical survey and analysis.

[Down-regulation of survivin in growth inhibition of hepatoma cells induced by a selective cyclooxygenase-2 inhibitor].

BACKGROUND/AIMS: Cyclooxygenase-2 (COX-2) inhibitors reportedly inhibit the growth of hepatocellular carcinoma (HCC) via caspase-dependent or caspase-independent apoptosis, which is due to COX-2 being associated with hepatocarcinogenesis. Survivin is highly expressed in most human cancers, but the mechanism regulating survivin expression remains unclear. We investigated the regulatory expression of survivin in selective-COX-2-inhibitor-induced growth inhibition of hepatoma cells. METHODS: After treatment with NS-398 (a selective COX-2 inhibitor) at various concentrations (10, 50, 100, 150, and 200 micrometer), the growth inhibition of Hep3B hepatoma cells was assessed by an MTT cell-viability assay, DNA fragmentation gel analysis, and flow cytometry. The expression of survivin transcript was analyzed by reverse-transcription polymerase chain reactions. RESULTS: NS-398 inhibited the growth of hepatoma cells by an amount dependent on the concentration and the time since treatment. Apoptotic DNA ladder and flow-cytometry shifting to the sub-G1 phase were revealed in NS-398-induced growth inhibition of hepatoma cells. NS-398 suppressed the expression of the survivin gene in a concentration- and time-dependent manner. CONCLUSIONS: Survivin was down-regulated in the growth inhibition of hepatoma cells induced by a selective COX-2 inhibitor, NS-398, in a concentration- and time-dependent manner. These results suggest the therapeutic inhibition of COX-2 via suppression of survivin in HCC.

[A case of hepatocellular carcinoma presented as a huge intrahepatic hematoma].

Spontaneous intrahepatic bleeding is a rare condition. In the absence of trauma, intrahepatic hematoma may be due to underlying liver disease. We report a case of hepatocellular carcinoma in the patient who had huge intrahepatic hematoma without definite intrahepatic tumor at the time of initial presentation. A 54-year-old man was admitted to our hospital with a sudden onset of upper abdominal pain. Initial abdominal CT scan showed huge hematoma measuring more than 13 cm in diameter in the right lobe of the liver. However, there was no enhancing lesion in the liver. Laboratory data showed high alanine aminotransferase, alpha-fetoprotein and positive HBsAg. The MRI and angiography could not also depict any mass in the liver. The patient was treated with percutaneous drainage on the intrahepatic hematoma. The cytology from drainaged blood revealed no malignant cell. After hematoma decreased, follow-up CT scan depicted an enhancing tumor in the liver. He underwent right hepatic lobectomy and histopathological examination showed hepatocellular carcinoma.

[A case of severe skin eruption caused by lamivudine in a patient with chronic hepatitis B].

Lamivudine is widely used for the treatment of chronic hepatitis B infection because of it's remarkable antiviral efficacy and safety. We report a case of severe skin eruption caused by lamivudine. A 47-year-old female was admitted because of jaundice and itching sensation. She was diagnosed as chronic hepatitis B infection a few years ago but did not receive any specific treatment. Laboratory data showed acute deterioration of chronic hepatitis B infection. We prescribed lamivudine as a rescue therapy. Her general condition improved and lab data showed improvement in liver function test thereafter. However, she complained of severe skin eruption and itching sensation a few days after the discharge. We stopped lamivudine because the symptoms did not improve despite the use of anti-histamine. Skin biopsy showed interface dermatitis. After stopping lamivudine, her symptoms improved. However, the skin eruption developed again after lamivudine was restarted. Adefovir was used instead, and the patient did not experience any further skin problems since then.