Malignant papillary neoplasms of the intrahepatic bile ducts: CT and histopathologic features

OBJECTIVE. We describe the CT and pathologic features of malignant papillary neoplasms of the intrahepatic bile ducts in 15 patients. CONCLUSION. CT is a useful technique for revealing intraductal lesions, although the findings are nonspecific and variable. When intraductal masses or nodules are seen with localized dilatation of the intrahepatic bile ducts on CT scans, malignant papillary neoplasms of the intrahepatic bile ducts should be included in the differential diagnosis.     

The impact of social capital on depression among older Chinese and Korean immigrants: similarities and differences

Objectives: The objective of this study is to examine similarities and differences in terms of the influence of social capital on depression among older Chinese and Korean immigrants.

Methods: The study used data collected from both 172 Chinese and 210 Korean immigrants living in Los Angeles County. The variables included depression Geriatric Depression Scale-Short Form, (GDS-SF), social capital (five indices of norms, trust, partnership in community, information sharing, and political participation), and demographics.

Results: The study found that partnership in community was significantly associated with a lower level of depression for both the groups. On the other hand, political participation was only associated with a lower level of depression for older Chinese immigrants. Also, norms and information sharing were only associated with a lower level of depression for older Korean immigrants.

Conclusion: There was an evidence for the correlation between social capital and depression in older Chinese and Korean immigrant population. It suggests the needs to develop social programs and service in order to build more social capital for older immigrants.     

Ultrasensitive detection of low-ppm H2S gases based on palladium-doped porous silicon sensors

In this study, the sensing properties of palladium-doped porous silicon (Pd/p-Si) substrates for low-ppm level detection of toxic H₂S gas are investigated. A Si substrate with dead-end pores ranging from nano- to macroscale was generated by a combined process of metal-assisted chemical etching (MacE) and electrochemical etching with tuned reaction time, in which nano-Pd catalysts were decorated by E-beam sputtering deposition. The sensing properties of the Pd/p-Si were enhanced as the thickness of the substrate layer increased; along with the resulting variation in surface area, this resulted in superior H₂S sensing performances in the low-ppm range (less than 3 ppm), with a detection limit of 300 ppb (sensitivity 30%) at room temperature. Furthermore, the sensor displayed excellent selectivity toward the hazardous H₂S molecules in comparison with various other reducing gases, including NO₂, CO₂, NH₃, and H₂, showing its potential for application in workplaces or environments affected by other toxic gases. The enhancement in sensing performance was possibly due to the increased dispersion and surface area of Pd nano-catalysts, which led to an increase in chemisorption sites of adsorbate molecules.

In this study, the sensing properties of palladium-doped porous silicon (Pd/p-Si) substrates for low-ppm level detection of toxic H₂S gas are investigated.     

Usefulness of Known Computed Tomography and Clinical Criteria for Diagnosing Strangulation in Small-Bowel Obstruction: Analysis of True and False Interpretation Groups in Computed Tomography

Computed tomography (CT) criteria have proven useful, but not sufficient, for diagnosis of bowel strangulation. The purpose of the present study was to evaluate the useof clinical criteria in the interpretation of CT scans as a means of improving the diagnostic accuracy of CT, especially in patients whose CT scans are equivocal for distinguishing simple obstruction from strangulated obstruction. We analyzed the CT scans of 136 patients with simple (n = 70) or strangulated (n = 66) small-bowel obstruction. Three radiologists interpreted the CT scans independently for the presence of intestinal strangulation. According to their interpretation, 136 patients were divided into two groups, i.e., a false and a true interpretation group. The diagnostic value of known CT and four clinical criteria (tenderness, tachycardia, fever, and leukocytosis) were compared in the two groups. The diagnostic accuracy of CT criteria for distinguishing simple obstructions from strangulated small-bowel obstructions ranged between 73% and 80%. Of the 136 patients, 31 belonged to the false group and 105 to the true group. The CT criteria that were highly specific in both groups included severe mesenteric haziness, serrated beak, and poor bowel wall enhancement. Among the clinical criteria, both tachycardia and leukocytosis were highly specific in both groups. The number of positive clinical criteria was helpful in making a diagnosis; none or one clinical criterion indicated a simple obstruction, whereas three or four criteria indicated a strangulated obstruction; when this result was applied retrospectively to the false group, the CT diagnostic accuracy improved in 19 of the 31 patients. The use of clinical criteria when CT findings are equivocal, may overcome the inherent limitations of CT for diagnosing strangulated small-bowel obstruction.