"In Our Own Little World": Invisibility of the Social and Ethical Dimension of Engineering Among Undergraduate Students.

This paper explores how undergraduate students understood the social relevance of their engineering course content knowledge and drew (or failed to draw) broader social and ethical implications from that knowledge. Based on a three-year qualitative study in a junior-level engineering class, we found that students had difficulty in acknowledging the social and ethical aspects of engineering as relevant topics in their coursework. Many students considered the immediate technical usability or improved efficiency of technical innovations as the noteworthy social and ethical implications of engineering. Findings suggest that highly-structured engineering programs leave little room for undergraduate students to explore the ethical dimension of engineering content knowledge and interact with other students/programs on campus to expand their "technically-minded" perspective. We discussed the issues of the "culture of disengagement" (Cech, Sci Technol Human Values 39(1):42-72, 2014) fueled by disciplinary elitism, spatial distance, and insulated curriculum prevalent in the current structure of engineering programs. We called for more conscious effort by engineering educators to offer meaningful interdisciplinary engagement opportunities and in-class conversations on ethics that support engineering students' holistic intellectual growth and well-rounded professional ethics.

Frequency, CT findings, and fate of multiple infarcted regenerative nodules in liver cirrhosis after variceal bleeding or septic shock.

PURPOSE: To evaluate the frequency, CT findings, and fate of multiple infarcted regenerative nodules in patients with liver cirrhosis after variceal bleeding or septic shock. METHODS: During a recent 3-year period, 492 patients with hematemesis or melena (n = 445) and septic shock (n = 47) in liver cirrhosis visited our hospital. After applying the exclusion criteria, 136 patients with active variceal bleeding and 29 patients with septic shock were finally included in the study. We diagnosed multiple infarcted regenerative nodules based on the findings of the first follow-up (within 30 days) CT after events. We evaluated the shape, number, size, margin, location, and distribution of the infarcted regenerative nodules. RESULTS: Thirty-four patients were diagnosed with multiple infarcted regenerative nodules (20.6% [34/165]): 29 among 136 patients with variceal bleeding (21.3% [29/136]) and 5 among 29 patients with septic shock (17.2% [5/29]). Most of the infarcted regenerative nodules were round in shape, more than ten in number (79.4%), measured 1 cm or less (76.3%), had well-defined margins (61.8%), were present in the periphery (67.6%), and had a clustered distribution (67.6%). Almost all of the infarcted regenerative nodules disappeared on the second follow-up CT (88.9% [16/18]). CONCLUSIONS: In cirrhotic patients, multiple infarcted regenerative nodules were not rare (they were found in about one-fifth of the patients) on the first follow-up CT after variceal bleeding or septic shock. Majority of the infarcted regenerative nodules were more than ten in number, measured 1 cm or less, were located in the periphery, and had a clustered distribution.

Role of endoscopic ultrasonography in patients with intermediate probability of choledocholithiasis but a negative CT scan.

BACKGROUND/GOALS: Despite the increased role of endoscopic ultrasonography (EUS) in diagnosis, few studies have evaluated its impact on the management of choledocholithiasis in a clinical setting for patients for whom computed tomography (CT) was conducted initially. Our aim in this study was to evaluate the role of EUS in patients with a diagnosis of intermediate probability of choledocholithiasis with a negative CT scan result. STUDY: A total of 98 patients who were diagnosed with symptomatic cholelithiasis with intermediate probability of choledocholithiasis were evaluated prospectively. Twenty-six of the 98 patients (26.5%) were diagnosed with choledocholithiasis by CT scans. The remaining 72 patients underwent EUS. RESULTS: Twenty-five of the 72 patients were shown to have choledocholithiasis (n=20/72, 27.8%) or papillitis with biliary outflow obstruction (n=5/72, 6.9%) on EUS. These 25 patients with positive EUS findings underwent endoscopic sphincterotomy, and choledocholithiasis was endoscopically confirmed in 23 of the 25 patients (92.0%). Postendoscopic retrograde cholangiopancreatography (ERCP) pancreatitis occurred in 3 patients (12.0% of the 25 patients who received ERCP, 4.2% of all 72 patients). Forty-seven patients with no evidence of choledocholithiasis on EUS were followed-up for a median period of 340 days (range, 185 to 755 d), and no recurrent biliary events occurred in these patients during this period. The sensitivity and specificity of EUS for choledocholithiasis was 87.0% and 100%, respectively. CONCLUSIONS: An EUS-first strategy in patients with intermediate probability of choledocholithiasis but a negative CT scan is very useful and can reduce the need to perform invasive ERCP.

Prediction of carcinoma after resection in subjects with ampullary adenomas on endoscopic biopsy.

BACKGROUND/GOALS: The endoscopic treatment of ampullary adenomas is established; however, the false-negative rate of endoscopic biopsy for carcinoma is 20% to 30%, and it remains uncertain whether identifiable features predict malignancy. Our aim in this study was to evaluate the predictable factors of malignancy in ampullary adenomas on endoscopic biopsy. STUDY: Ninety-one subjects diagnosed with ampullary adenoma on endoscopic biopsy were confirmed after endoscopic or surgical resection of ampullary lesions between 1995 and 2011 respectively. Clinical, laboratory, radiologic, and endoscopic findings were compared between patients with adenoma and carcinoma after resection. We examined the predictors of malignancy in ampullary adenoma on endoscopic biopsy. RESULTS: The malignancy rate in ampullary adenomas on endoscopic biopsy was 26.4%. Univariate analysis revealed that presence of symptoms, villous components, high-grade dysplasia (HGD), papilla enlargement on computed tomography, duct dilatation on radiologic imaging, bilirubin>2 mg/dL, aspartate aminotransferase>40 IU/L, alanine aminotransferase>40 IU/L, and alkaline phosphatase>90 U/L were associated with malignancy in patients over 65 years of age. HGD [odds ratio, 6.86 (95% confidence interval, 1.58-29.79)] and ductal dilatation [odds ratio, 11.12 (95% confidence interval, 2.27-54.37)] were independently associated with malignancy in multivariate analysis. The sensitivity and negative predictive value for ≥1 risk factors were 95.83% and 96.77%, respectively. The presence of 2 risk factors resulted in a high specificity (96%) and positive predictive value (84%) for malignancy. CONCLUSIONS: HGD and ductal dilatation are significant predictors of malignancy in ampullary adenomas. When these risk factors are present, precautions should be taken in the consideration of malignancy in patients with ampullary adenoma.

Intraductal growing acinar cell carcinoma of the pancreas.

Acinar cell carcinoma (ACC) is a rare pancreatic exocrine neoplasm characterized by a huge, exophytic well-circumscribed hypovascular mass. There has been several reports describing intraductal and papillary variant of ACC and they showed different radiologic features from usual ACC. We present histologically confirmed cases of intraductal and papillary variant of ACC that had been found in two patients, who underwent CT and MRI. This report provides CT and MRI features of intraductal and papillary variant of ACC in pancreas with pathologic correlation after surgical excision.

Intraductal papillary neoplasm of the bile ducts: description of MRI and added value of diffusion-weighted MRI.

PURPOSE: To evaluate MRI features of intraductal papillary neoplasm of the bile duct (IPNB) and to determine added value of diffusion-weighted MRI (DWI). METHODS: Twenty-three patients with surgically confirmed invasive (n = 12) and non-invasive (n = 11) IPNB, who underwent preoperative liver MRI were included. Two observers performed consensus review of gadoxetic acid-enhanced MRI and combined gadoxetic acid-enhanced MRI including DWI separately, with regard to conspicuity of intraductal tumor using five point scales, extent of tumors, and the presence of invasiveness. RESULTS: On MRI, there was no significant difference in the conspicuity of intraductal tumors between gadoxetic acid MRI (mean, 4.35) and combined MRI (mean, 4.65) (P = 0.09). However, addition of DWI led seven cases revealed excellent conspicuity as compared with good or moderate conspicuity on gadoxetic acid MRI. With regard to invasiveness, 11 cases (48 %) and 17 (74 %) were correctly diagnosed with gadoxetic acid MRI and combined MRI, respectively (P = 0.06). In invasive tumors, both of the two image sets did not help assess accurate extent of the tumor. CONCLUSIONS: The addition of DWI to gadoxetic acid-enhanced MRI has a potency to improve conspicuity for intraductal tumors of IPNB and is helpful in determining tumor invasiveness, but not tumor extent.

Peritoneal manifestations of fascioliasis on CT images: a new observation.

PURPOSE: To describe peritoneal manifestations of fascioliasis on CT. MATERIALS AND METHODS: We reviewed CT images in 31 patients with fascioliasis confirmed by enzyme-linked immunosorbent assay (ELISA) (n = 24) or surgery (n = 7). Image analyses were performed to identify hepatic, biliary, and peritoneal abnormalities. RESULTS: Hepatic abnormalities were seen in 28 (90.3 %) of the 31 patients. The most common finding was caves sign, which was present in 25 (80.1 %) patients. Three patients (9.7 %) presented with biliary abnormalities exhibiting dilatation and enhancing wall thickening of the bile duct, wall thickening of the gallbladder, and elongated structures in the bile duct or gallbladder. Peritoneal abnormalities were seen in 14 (45.2 %) of the 31 patients. The most common peritoneal abnormality was mesenteric or omental infiltration, which was seen in 9 (29.0 %) patients. Other peritoneal findings included lymph node enlargement (n = 7), ascites (n = 7), thickening of ligamentum teres (n = 2), and peritoneal mass (n = 2). CONCLUSION: Peritoneal manifestations of fascioliasis are relatively common, and CT findings include mesenteric or omental infiltration, lymph node enlargement, ascites, thickening of the ligamentum teres, and peritoneal masses.

The differentiation of autoimmune pancreatitis and pancreatic cancer using imaging findings.

BACKGROUND/AIMS: Differentiation of autoimmune pancreatitis (AIP) and pancreatic cancer (PC) is important to avoid unnecessary surgery. The aim of this study was to compare various image findings and facilitate the differentiation of these two diseases. METHODOLOGY: The radiological features of 36 AIP patients and 36 patients with resected PC diagnosed at Samsung Medical Center from January 1991 to October 2010, were compared. RESULTS: Regarding CT/MRI findings, diffuse pancreas enlargement, capsule-like rim and delayed homogenous enhancement, were significantly more frequent in AIP. For cholangiopancreatography findings, main pancreatic duct (MPD) narrowing by ≥1/3 of the pancreatic length, skipped lesions of the MPD, the presence of side branches at the narrowed MPD portion, and smooth and straight intrapancreatic common bile duct stenosis were significantly more frequent in AIP. However, according to FDG-PET findings, SUVmax, uptake shape and pattern, and uptake by extrapancreatic lesions were not significantly different for AIP and PC. CONCLUSIONS: Diffuse pancreas enlargement, a capsule-like rim, delayed homogenous enhancement, MPD narrowing of ≥1/3 of the pancreatic length, skipped lesions and the presence of side branches at the narrow MPD portion were found to have high specificity for AIP. These findings have great power to differentiate AIP and PC.

Systemic Venous Air Emboli After Emergent Hyperbaric Therapy for Carbon Monoxide Poisoning.

BACKGROUND A venous air embolism is a rare condition but could have a disastrous effect on vital organs. It usually occurs due to iatrogenic sources, such as central venous catheter insertion, neurosurgery, and other invasive procedures. In most cases, hyperbaric oxygen therapy (HBOT) is the best treatment for those conditions. However, multiple venous air emboli after hyperbaric oxygen therapy has not been reported in the literature. CASE REPORT An 82-yr-old woman came to the Emergency Department after inhalation of fumes at the scene of a house fire. She had dizziness and nausea. Her vital signs were normal at the time of presentation. She received HBOT for carbon monoxide poisoning. Soon after the HBOT, the patient started to have dizziness, abdominal pain, and leg pains. Computed tomography scans showed multiple systemic venous air emboli throughout the portal venous system and femoral veins. The air emboli totally disappeared after HBOT with a longer ascent time. CONCLUSIONS To the best of our knowledge, this is the first case of multiple systemic venous air bubbles after emergent HBOT. Physicians should be aware of any kind of complications when treating patients who need HBOT in the emergent setting. Although decompression sickness following HBOT is extremely rare, it should not be ignored by emergency physicians.

Clinicopathologic features of intraductal papillary neoplasm of the bile duct according to histologic subtype.

OBJECTIVES: Despite an increase in the reports of intraductal papillary neoplasm of the bile duct (IPN-B), the clinical characteristics and long-term prognosis of this disease are not well known compared with those of intraductal papillary mucinous neoplasms of the pancreas. The objective of our study was to compare the clinical features, radiologic findings, and clinical outcomes of IPN-B according to histologic subtype. METHODS: A retrospective analysis was performed on the medical records of 97 patients diagnosed with IPN-B by pathologic analysis of their surgical specimens between May 1995 and May 2010. We compared the clinical manifestations, radiological findings, pathologic grade, curative resection rate, recurrence, and overall survival according to four histologic subtypes: gastric (n=15), intestinal (n=46), pancreaticobiliary (n=33), and oncocytic (n=3), which were classified on the basis of hematoxylin and eosin staining and the immunohistochemical profile of mucin core proteins. RESULTS: Mucin hypersecretion was significantly more frequent in patients with gastric and intestinal types than it was in those with oncocytic and pancreaticobiliary types (P=0.014). There were no significant differences between groups regarding the presence of bile duct stones or tumor location. The frequency of invasive carcinoma in the pancreaticobiliary type was significantly higher than those in the gastric and intestinal types (72.7 vs. 26.7 and 32.6%, P<0.001 and P<0.001). When comparing the survival curves according to histologic subtype, patients with pancreaticobiliary type demonstrated significantly worse survival compared to those with gastric and intestinal types (P=0.035). CONCLUSIONS: Gastric and intestinal types of IPN-B have similar clinical characteristics compared with the pancreaticobiliary type, which has a worse prognosis.

Outcomes of therapeutic hypothermia in unconscious patients after near-hanging.

BACKGROUND: Hanging has been increasingly used to commit suicide. There is no specific treatment besides general intensive care after near-hanging. Therapeutic hypothermia (TH) has been used in unconscious patients after near-hanging. OBJECTIVE: To describe the outcomes in unconscious patients after near-hanging in order to determine whether TH improves the outcome of near-hanging injury. METHODS: Medical charts were reviewed of unconscious patients after near-hanging who presented to Chonnam National University Hospital between January 2006 and December 2010 and who were considered to be eligible for TH. According to local policy, unconscious survivors after near-hanging, whether or not they experienced cardiac arrest at the scene, were treated with TH if this was agreed by next-of-kin. RESULTS: There were 16 survivors of asphyxial cardiac arrest after near-hanging, of whom 13 received TH. Among them, only one (7.7%, 95% CI 1.4% to 33.3%) attained Cerebral Performance Category (CPC) 1; the other 15 patients had poor neurological outcomes (CPC 5 in seven patients and CPC 4 in eight patients). Nine of the patients did not experience cardiac arrest at the scene and of these, four received TH and five received normothermic treatment. All patients who did not have cardiac arrest recovered and were discharged with CPC 1. CONCLUSION: In this study, outcomes in unconscious near-hanging patients with cardiac arrest were poor despite treatment with TH. Before recommending TH in near-hanging patients, a prospective, randomised controlled study is required.

Transmission of Toxocara canis via ingestion of raw cow liver: a cross-sectional study in healthy adults.

The aim of this study is to ascertain the relationship between ingestion of raw cow liver and Toxocara canis infection. A total of 150 apparently healthy adults were divided into 2 groups; 1 group consisted of 86 adults with positive results of Toxocara ELISA, and the other group of 64 adults with negative results. One researcher collected the history of ingestion of raw cow liver within 1 year and recent history of keeping dogs. Among 86 seropositive adults for T. canis, 68 (79.1%) had a recent history of ingestion of raw cow liver. Multivariate statistical analysis showed that a recent ingestion of raw cow liver and keeping dogs were related to an increased risk of toxocariasis (odds ratios, 4.4 and 3.7; and 95% confidence intervals, 1.9-10.2 and 1.2-11.6, respectively). A recent history of ingestion of raw cow liver and keeping dogs was significantly associated with toxocariasis.

Role of multidetector computed tomography in patients with acute infectious colitis.

BACKGROUND: The role of multidetector computed tomography (MDCT) in patients with acute infectious colitis is still unclear. AIM: To examine the usefulness of MDCT in distinguishing the etiology of acute infectious colitis. METHODS: Overall, 244 patients who met the criteria for acute infectious colitis and visited the Hospital from February 2015 to 2018 were retrospectively enrolled and divided into two groups (bacterial: 204, viral: 40) according to causes of acute colitis, based on stool PCR. Eleven MDCT parameters, including wall thickening, submucosal edema, mucosal enhancement, serosa involvement, empty colon sign, small bowel involvement, comb sign, continuous distribution, accordion sign, mucosal thickening, and lymph node enlargement, were constructed in a blinded fashion. RESULTS: MDCT parameters of wall thickening (OR: 13.60; 95%CI: 5.80-31.88; P < 0.001), submucosal edema (OR: 36.08; 95%CI: 13.54-96.13; P < 0.001), mucosal enhancement (OR: 22.55; 95%CI: 9.28-54.81; P < 0.001), serosal involvement (OR: 14.50; 95%CI: 3.33-63.23; P < 0.001), empty colon sign (OR: 6.68; 95%CI: 2.44-18.32; P < 0.001), continuous distribution (OR: 24.09; 95%CI: 9.38-61.90; P < 0.001), accordion sign (OR: 9.02; 95%CI: 1.12-72.35; P = 0.038), mucosal thickening (OR: 46.41; 95%CI: 10.38-207.51; P < 0.001), and lymph node enlargement (OR: 4.39; 95%CI: 1.22-15.72; P = 0.023) were significantly associated with bacterial colitis. At least one positive finding in four CT outcomes (submucosal edema, mucosal enhancement, continuous distribution, mucosal thickening) in summer showed a high probability of bacterial colitis (sensitivity, 41.67; specificity, 92.50; OR: 24.95). CONCLUSION: MDCT provides many clues that can be useful in suggesting a specific etiology of acute infectious colitis.

Cyst-forming intraductal papillary neoplasm of the bile ducts: description of imaging and pathologic aspects.

OBJECTIVE: Intraductal papillary neoplasm (IPN) of the bile duct is a newly described pathologic entity characterized by the presence of intraluminal tumors, which sometimes produce a large amount of mucin and form a cystic tumor. Cystic IPN of the bile duct is different from biliary cystadenoma or cystadenocarcinoma in that the former produces intraductal microscopic and macroscopic papillary tumors without ovarian-like stroma, whereas the latter produce a mucin-containing septate cystic tumor without communication with bile duct and with ovarian-like stroma in the cyst wall. The purpose of this study was to evaluate the potential relationships between cyst-forming IPNs of the bile duct and peribiliary glands and also intraductal papillary mucinous neoplasms of the pancreas. MATERIALS AND METHODS: From a cohort of 87 patients with surgically resected and pathologically proved IPN of the bile duct, 12 patients with cystic IPN of the bile duct who underwent CT (n = 12), MRCP (n = 3), ultrasound (n = 3), and ERCP (n = 4) were included. Imaging findings were evaluated for the relationship of cystic tumors to the bile ducts; in particular, a diverticulum-like appearance was considered as suggestive of the peribiliary gland origin. Pathologic examination was conducted, and both gross and microscopic findings were recorded. RESULTS: Radiologic examination revealed aneurysm-like dilatation of the involved bile ducts in five patients and intrahepatic biliary cystic tumor in two patients. Interestingly, the remaining five patients had diverticulum-like cystic tumor with or without communication; one patient had a cystic tumor laterally attached to the extrahepatic bile duct. Histopathologically, cystic tumors are lined by atypical biliary epithelium showing intracystic papillary proliferation, with an appearance similar to that of pancreatic intraductal papillary mucinous neoplasm. CONCLUSION: This study suggests that cyst-forming IPN of the bile duct may be a biliary counterpart to pancreatic intraductal papillary mucinous neoplasm. In particular, at least some of the tumors seem to arise from peribiliary glands, and these cases might be a counterpart to branch-duct intraductal papillary mucinous neoplasm of the pancreas, given the histologic similarity between peribiliary glands and pancreatic branch ducts.

Preoperative evaluation of the longitudinal extent of borderline resectable hilar cholangiocarcinoma by intraductal ultrasonography.

BACKGROUND AND AIM: In patients with hilar cholangiocarcinoma (HC), longitudinal tumor extent is important for curative resection. The purpose of this study was to evaluate the longitudinal extents of HC using transpapillary intraductal ultrasonography (IDUS) for optimal surgical planning. METHODS: From July 2006 to April 2010, a total of 42 patients with borderline resectable HC were enrolled at Samsung Medical Center, a tertiary referral hospital in Seoul, Korea. All patients were evaluated using multi-detector computed tomography (MDCT), endoscopic retrograde cholangiopancreatography (ERCP) and IDUS. The new modified Bismuth Type (MBT) classification, in which the traditional Bismuth type IV stage is divided into stages IVa and IVb, was used to determine whether the tumor invaded the left lateral section. Among the subtypes of HC, the periductal infiltrative type (PDI) and intraductal papillary neoplasm of the bile duct (IPN-B) were compared. The accuracies of CT, ERCP, and IDUS were assessed through comparison with the postoperative histology findings. RESULTS: A total of 42 patients were prospectively enrolled, and the tumor extent could be assessed histologically in 30 patients. The accuracies of CT, ERCP, and IDUS were 66.6%, 60%, and 90%, respectively. The accuracy of IDUS was 85.7% in 21 patients with PDI and 100% in nine patients with IPN-B. CONCLUSIONS: Hilar cholangiocarcinoma staging based on IDUS findings was highly accurate. We therefore highly recommend using IDUS for optimal surgical planning in patients with borderline resectable HC.

Morphology of intraductal papillary neoplasm of the bile ducts: radiologic-pathologic correlation.

PURPOSE: Intraductal papillary neoplasm of the bile duct (IPN-B) is known as a premalignant lesion of invasive cholangiocarcinoma. The purpose of this study was for radiologic-pathologic correlation of morphologic features of IPN-B and to correlate the subclassifications with biological behavior in regard to the bile duct wall invasion. MATERIALS AND METHODS: A pathologist classified gross morphology of 75 cases (44 men and 31 women, age range, 39-85) of histopathologically proven IPN-B into polypoid, cast-like, superficial-spreading, and cyst-forming type. Preoperative images were retrospectively reviewed by two observers independently and classified the gross appearance of intraductal tumors into the four types. RESULTS: The pathologist classified macroscopic appearances of 75 cases of IPN-B into polypoid type in 26, cast-like intraductal growth in 17, superficial-spreading growth in 21, and cyst-forming type in 11. Two observers classified image findings in accordance with pathologist's classification in 58 and 57 (77% and 76%) among the 75 cases of IPN-B, respectively; 18 and 19 of 26 cases of polypoid type, 14 and 14 of 17 cases of cast-like growth type, 16 and 19 of 21 cases of superficial-spreading type, 10 and 5 of 11 cases of cyst-forming type, respectively. Interobserver agreement for subclassification of tumor morphology was in the category of good agreement (k = 0.651). There was no correlation between morphological subclassification and tendency to invasive cholangiocarcinoma. CONCLUSION: IPN-Bs can be classified morphologically into polypoid, cast-like growth, superficial-spreading, and cystic type, but there is no correlation between the types and tendency to invasive cholangiocarcinoma.

The clinicopathological features of biliary intraductal papillary neoplasms according to the location of tumors.

BACKGROUND AND AIM: In this study, we analyzed the clinical and pathological features of biliary intraductal papillary neoplasms (IPN-B) according to the location of the tumors. METHODS: A total of 55 patients with IPN-B were analyzed. We divided them into three groups: common bile duct (CBD), hilar, and intrahepatic duct (IHD) groups. The clinical and laboratory findings, cell types, depth of invasion, malignancy, existence of stones, lymph node metastasis, recurrence, and survival rate were analyzed. RESULTS: There was no difference in the depth of invasion, lymph node metastasis, and coexistence of stones between the three groups. There were four different cell types; the intestinal cell type was the most common type in each group. The gastric cell type was prevalent in the IHD and hilar groups (58.3% and 33.3%, respectively). Invasive colloid carcinoma mainly showed the intestinal cell type, and tubular carcinoma showed the pancreaticobiliary cell type. There was a trend that malignancy was more prevalent in the CBD group (94.1%) than in the hilar group (64.3%) and IHD group (79.2%), but there was no statistically significant difference. There was no difference in the recurrence rate and the 3-year survival rate between the three groups. CONCLUSION: IPN-B showed no difference in the malignancy and survival rates according to the location of the tumors. Because IPN-B show good prognosis after surgery, aggressive surgical resection for the treatment of IPN-B is recommended.

Are the echogenicities on intraductal ultrasonography really biliary microlithiasis?

BACKGROUND: Intraductal ultrasonography (IDUS) is a useful procedure for diagnosing microlithiasis in the bile duct but it is not easy to differentiate between tiny echogenicity and real microlithiasis. We compared the echogenicity seen on IDUS and the findings of bile microscopy (BM) of bile that was collected in the common bile duct (CBD) to determine whether the echogenicity seen on IDUS is real microlithiasis. METHODS: This prospective study involved a total of 30 patients who experienced biliary pain (n = 11), acute cholecystitis (n = 11) or indeterminate pancreatitis (n = 8) without a filling defect or obstruction in the bile duct. IDUS was performed during endoscopic retrograde cholangiopancreatography (ERCP), followed by bile aspiration for BM. Endoscopic sphincterotomy (EST) was performed if definite echogenic materials were observed on IDUS. RESULTS: Of the 30 patients, 23 (77%) had echogenic materials visible in the CBD on IDUS. Of these 23 patients, 13 (57%) were found to have biliary crystals by BM. The size of the echogenic materials was the only significant factor associated with BM positivity. Using the receiver operating curve, the optimal size of the echogenicity to differentiate real microlithiasis was 1.4 mm. CONCLUSIONS: Optimal concordance between IDUS and BM was observed when the size of the microlithiasis was greater than 1.4 mm; under these conditions the sensitivity and specificity were 71% and 75%, respectively. This information may be useful when deciding whether to perform endoscopic sphincterotomy.

Omental Torsion and Infarction Secondary to Omental Hernia in the Right Inguinal Canal.

Omental torsion secondary to inguinal hernia has rarely been reported as a cause of acute abdominal pain. However, in our case, omental infarction due to prolonged inguinal hernia-associated omental torsion led to the formation of a large omental mass with marginal fibrosis, and the patient presented with chronic abdominal pain. A 74-year-old man presented with complaints of lower abdominal pain for 1 month; subsequently, bilateral inguinal hernias were identified through inguinal ultrasonography. CT scans revealed that the greater omentum was trapped within the right inguinal canal, leading to omental torsion. The greater omentum, distal to the pedicle, appeared as a 30 cm-sized oblong fibrofatty mass in the right lower abdomen and pelvic cavity. Laparoscopic omentectomy with hernia repair was successfully performed.

Effect of Electron Injection Layer on the Parasitic Recombination at the Hole Transport Layer/Quantum Dot Interface in Quantum Dot Light-Emitting Diodes.

Zinc oxide (ZnO) nanoparticles layers are used as a substitute for organic electron transport layer due to high electron mobility, higher thermal stability and less sensitivity to the oxygen/moisture. In this study, we investigated the electron injection properties of ZnO nanoparticles in QLED compared with TPBi commonly used as injection layer in OLEDs. The expected electron injection barrier from energy diagram is similar in both devices, but the current density of the ZnO injection layer was slightly high compared with the TPBi injection layer. The current efficiency of ZnO and TPBi devices were 5.21 cd/A and 2.24 cd/A, respectively. The current efficiency of TPBi device is below half of ZnO device. We found that the electron-hole recombination occurs not only in the QD but also in the poly-TPD for TPBi device.