The occlusion illusion: Partial modal completion or apparent distance?

In the occlusion illusion, the visible portion of a partly occluded object (eg a semicircle partly hidden behind a rectangle) appears to be significantly larger than a physically identical region that is fully visible. This illusion may occur either because the visual system 'fills in' a thin strip along the occluded border (the partial-modal-completion hypothesis) or because the partly occluded object is perceived as farther away (the apparent-distance hypothesis). We measured the magnitude of the occlusion illusion psychophysically in several experiments to investigate its causes. The results of experiments 1-3 are consistent with the general proposal that the magnitude of the illusion varies with the strength of the evidence for occlusion, supporting the inference that it is due to occlusion. Experiment 4 provides a critical test between apparent-distance and partial-modal-completion explanations by determining whether the increase in apparent size of the occluded region results from a change in its perceived shape (due to the modal extension of the occluded shape along the occluding edge, as predicted by the partial-modal-completion hypothesis) or from a change in its perceived overall size (as predicted by the apparent-distance hypothesis). The results more strongly support the partial-modal-completion hypothesis

Prognostic Factors for Transplant-Free Survival and Validation of Prognostic Models in Chinese Patients with Primary Biliary Cholangitis Receiving Ursodeoxycholic Acid

OBJECTIVES: We aimed to validate the prognostic models for primary biliary cholangitis (PBC) in Chinese patients receiving ursodeoxycholic acid (UCDA), and to compare their performances in predicting the long-term survival. METHODS: Chinese patients with PBC from a tertiary center were identified via electronic search of hospital medical registry. Risk factors associated with adverse events (liver transplantation or death from liver-related causes including hepatocellular carcinoma (HCC) and liver decompensation) were determined. Transplant-free survival was defined as survival free of liver-related death or transplantation. RESULTS: Of the 144 patients, 41 (28.5%) had baseline cirrhosis. The median age at diagnosis was 57.8 years. During a median follow-up of 7.0 years, 40 patients died (21 liver-related; 19 non-liver-related), 12 developed HCC, and 10 underwent transplantations. The 5-, 10-, and 15-year transplant-free survival probabilities were 91.0%, 78.1%, and 58.9%, respectively. Independent risk factors for adverse events were increasing age (hazard ratio (HR) 1.05), cirrhosis (HR 8.53), and suboptimal treatment response (HR 3.06). Aspartate aminotransferase/platelet ratio index at 1 year (APRI-r1) in combination with treatment response optimized the risk stratification. The performances of the GLOBE, UK-PBC scores, Rotterdam criteria, and APRI-r1 were comparable in predicting adverse events. The area under receiver operating curves within 5, 10, and 15 years were as follows-GLOBE score: 0.83, 0.85, and 0.85, respectively; UK-PBC score: 0.89, 0.83, and 0.79, respectively; Rotterdam criteria: 0.82, 0.76, and 0.80, respectively; APRI-r1: 0.80, 0.83, and 0.77, respectively. CONCLUSIONS: The UK-PBC, GLOBE scores, Rotterdam criteria, and APRI-r1 had good and comparable prognostic prediction values for Chinese PBC patients receiving UCDA.published_or_final_versio

Epidemiology and Natural History of Primary Biliary Cholangitis in the Chinese: A Territory-Based Study in Hong Kong between 2000 and 2015

OBJECTIVES: Studies on the epidemiology of primary biliary cholangitis (PBC) in the Chinese population are lacking. We aimed to determine the epidemiology of PBC in Hong Kong (HK) with a population of 7.3 million. METHODS: We retrieved data from the electronic database of the HK Hospital Authority, the only public healthcare provider in Hong Kong. PBC cases between 2000 and 2015 were identified by International Classification of Diseases (ICD)-9 code. We estimated the age-/sex-adjusted incidence rate and prevalence of PBC, and analyzed the adverse outcomes (hepatocellular carcinoma (HCC), liver transplantation, and death). RESULTS: One thousand and sixteen PBC patients aged >/=20 years were identified (female-to-male ratio 4:1; median age 60.6 years, interquartile range (IQR) 51.8-72.6 years; median follow-up 5.6 years, IQR 1.6-8.7 years). The average age/sex-adjusted annual incidence rate and prevalence were 8.4 per million person-years and 56.4 per million, respectively. Between 2000 and 2015, the age/sex-adjusted annual incidence rate increased from 6.7 to 8.1 per million person-years (Poisson P=0.002), while age/sex-adjusted prevalence increased from 31.1 to 82.3 per million (Poisson P<0.001). Fifty patients developed HCC, and 49 underwent liver transplantation. Case fatality risk decreased from 10.8 to 6.4% (Poisson P=0.003). The 5- and 10-year overall survival rates were 81.5 and 78.3%, whereas the transplant-free survival rates were 78.0% and 74.3%, respectively. Increasing age, cirrhosis and being treatment-naive were associated with lower transplant-free survival. CONCLUSIONS: There is a considerable increase in the incidence and prevalence of PBC in the Chinese population over the past 16 years, with significant morbidity and mortality.published_or_final_versio

Measurement Invariance of the Internet Addiction Test Among Hong Kong, Japanese, and Malaysian Adolescents

There has been increased research examining the psychometric properties on the Internet Addiction Test across different ages and populations. This population-based study examined the psychometric properties using Confirmatory Factory Analysis and measurement invariance using Item Response Theory (IRT) of the IAT in adolescents from three Asian countries. In the Asian Adolescent Risk Behavior Survey (AARBS), 2,535 secondary school students (55.91% girls) in Grade 7 to Grade 13 (Mean age = 15.61 years; SD=1.56) from Hong Kong (n=844), Japan (n=744), and Malaysia (n=947) completed a survey on their Internet use that incorporated the IAT scale. A nested hierarchy of hypotheses concerning IAT cross-country invariance was tested using multi-group confirmatory factor analysis. Replicating past finding in Hong Kong adolescents, the construct of IAT is best represented by a second-order three-factor structure in Malaysian and Japanese adolescents. Configural, metric, scalar, and partial strict factorial invariance was established across the three samples. No cross-country differences on Internet addiction were detected at latent mean level. This study provided empirical support to the IAT as a reliable and factorially stable instrument, and valid to be used across Asian adolescent populations

Wisteria floribunda agglutinin-positive human Mac-2 binding protein predicts liver cancer development in chronic hepatitis B patients under antiviral treatment

AIM: The risk factors for hepatocellular carcinoma (HCC) development in chronic hepatitis B (CHB) patients with undetectable serum HBV DNA under nucleos(t)ide analogue (NA) therapy are not well defined. We aimed to examine the relationship between Wisteria floribunda agglutinin-positive human Mac-2 binding protein (WFA+-M2BP) and HCC development in these patients. RESULTS: There was a significant difference in the median levels of pre-treatment WFA+-M2BP between the HCC and control groups (0.67 vs 0.41 COI, respectively, p < 0.001). Among patients with cirrhosis, the median level of WFA+-M2BP was higher in HCC group than in control group (0.74 vs 0.47 COI, respectively, p = 0.014). Among patients without cirrhosis, the median level of WFA+-M2BP of HCC group was also higher (0.48 vs 0.28 COI, respectively, p = 0.002). With a cutoff value of 0.69, the AUROC of pre-treatment WFA+-M2BP to predict HCC development for the whole cohort was 0.70. With cutoff values of 0.69 and 0.34, the AUROCs to predict HCC were 0.67 and 0.77 for patients with and without cirrhosis, respectively. MATERIALS AND METHODS: Fifty-seven NA-treated patients with undetectable HBV DNA who developed HCC were compared with 57 controls (matched with demographics and treatment duration). WFA+-M2BP levels were measured, and expressed as cutoff index (COI). Subgroup analyses were also performed in patients with and without cirrhosis. CONCLUSIONS: A higher pre-treatment WFA+-M2BP level was associated with an increased risk of HCC development in patients with undetectable HBV DNA under NA therapy. Further longitudinal studies are required to examine the role of WFA+-M2BP as an accessory risk marker for HCC development.published_or_final_versio

Tellurium quantum dots: Preparation and optical properties

Herein, we report an effective and simple method for producing Tellurium Quantum dots (TeQDs), zero-dimensional nanomaterials with great prospects for biomedical applications. Their preparation is based on the ultrasonic exfoliation of Te powder dispersed in 1-methyl-2-pyrrolidone. Sonication causes the van der Waals forces between the structural hexagons of Te to break so that the relatively coarse powder breaks down into nanoscale particles. The TeQDs have an average size of about 4 nm. UV-Vis absorption spectra of the TeQDs showed an absorption peak at 288 nm. Photoluminescence excitation (PLE) and photoluminescence (PL) are used to study the optical properties of TeQDs. Both the PLE and PL peaks revealed a linear relationship against the emission and excitation energies, respectively. TeQDs have important potential applications in biological imaging and catalysis as well as optoelectronics

Self-perceived competence correlates poorly with objectively measured competence in Evidence Based Medicine among medical students

<p>Abstract</p> <p>Background</p> <p>Previous studies report various degrees of agreement between self-perceived competence and objectively measured competence in medical students. There is still a paucity of evidence on how the two correlate in the field of Evidence Based Medicine (EBM). We undertook a cross-sectional study to evaluate the self-perceived competence in EBM of senior medical students in Malaysia, and assessed its correlation to their objectively measured competence in EBM.</p> <p>Methods</p> <p>We recruited a group of medical students in their final six months of training between March and August 2006. The students were receiving a clinically-integrated EBM training program within their curriculum. We evaluated the students' self-perceived competence in two EBM domains ("searching for evidence" and "appraising the evidence") by piloting a questionnaire containing 16 relevant items, and objectively assessed their competence in EBM using an adapted version of the Fresno test, a validated tool. We correlated the matching components between our questionnaire and the Fresno test using Pearson's product-moment correlation.</p> <p>Results</p> <p>Forty-five out of 72 students in the cohort (62.5%) participated by completing the questionnaire and the adapted Fresno test concurrently. In general, our students perceived themselves as moderately competent in most items of the questionnaire. They rated themselves on average 6.34 out of 10 (63.4%) in "searching" and 44.41 out of 57 (77.9%) in "appraising". They scored on average 26.15 out of 60 (43.6%) in the "searching" domain and 57.02 out of 116 (49.2%) in the "appraising" domain in the Fresno test. The correlations between the students' self-rating and their performance in the Fresno test were poor in both the "searching" domain (r = 0.13, p = 0.4) and the "appraising" domain (r = 0.24, p = 0.1).</p> <p>Conclusions</p> <p>This study provides supporting evidence that at the undergraduate level, self-perceived competence in EBM, as measured using our questionnaire, does not correlate well with objectively assessed EBM competence measured using the adapted Fresno test.</p> <p>Study registration</p> <p>International Medical University, Malaysia, research ID: IMU 110/06</p

Treatment of severe acute respiratory syndrome with lopinavir/ritonavir: A multicentre retrospective matched cohort study

Objectives. To investigate the possible benefits and adverse effects of the addition of lopinavir/ritonavir to a standard treatment protocol for the treatment of severe acute respiratory syndrome. Design. Retrospective matched cohort study. Setting. Four acute regional hospitals in Hong Kong. Patients and methods. Seventy-five patients with severe acute respiratory syndrome treated with lopinavir/ritonavir in addition to a standard treatment protocol adopted by the Hospital Authority were matched with controls retrieved from the Hospital Authority severe acute respiratory syndrome central database. Matching was done with respect to age, sex, the presence of co-morbidities, lactate dehydrogenase level and the use of pulse steroid therapy. The 75 patients treated with lopinavir/ritonavir were divided into two subgroups for analysis: lopinavir/ritonavir as initial treatment, and lopinavir/ritonavir as rescue therapy. These groups were compared with matched cohorts of 634 and 343 patients, respectively. Outcomes including overall death rate, oxygen desaturation, intubation rate, and use of pulse methylprednisolone were reviewed. Results. The addition of lopinavir/ritonavir as initial treatment was associated with a reduction in the overall death rate (2.3%) and intubation rate (0%), when compared with a matched cohort who received standard treatment (15.6% and 11.0% respectively, P<0.05) and a lower rate of use of methylprednisolone at a lower mean dose. The subgroup who had received lopinavir/ritonavir as rescue therapy, showed no difference in overall death rate and rates of oxygen desaturation and intubation compared with the matched cohort, and received a higher mean dose of methylprednisolone. Conclusion. The addition of lopinavir/ritonavir to a standard treatment protocol as an initial treatment for severe acute respiratory syndrome appeared to be associated with improved clinical outcome. A randomised double-blind placebo-controlled trial is recommended during future epidemics to further evaluate this treatment.published_or_final_versio