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Background Despite the widespread use of portfolios in medical education, their outcomes remain variable. This study evaluated students’ perceptions of portfolios at an institution that recently adopted an outcome-based curriculum. Methods This descriptive cross-sectional study involved 4th, 5th, and 6th -year medical students ( n  = 94; response rate = 64.8%) at Prince Sattam Bin Abdulaziz University, Saudi Arabia, during the 2023–2024 academic year. A 13-item Likert-type questionnaire assessed students’ portfolio perceptions across five domains: design, feedback and reflection, benefits in assessment, openness to their broader use in the college, and usefulness. Students’ Grade Point Average (GPA) was also recorded as an index of academic performance. Data were analyzed quantitatively; results were expressed as frequencies, means, medians, and percentages. Correlation analyses were conducted to explore the relationships between overall portfolio perception and other measured domains. Results Ninety four students participated in this study. Only 48.9% of students found portfolios useful, with neutral average score of 3.3 ± 1.4 on the Likert scale and 5.66 ± 2.7 on the visual scale. Fewer than half reported positive perceptions across the five assessed domains. Differences in perceptions across academic levels were analyzed using the Kruskal-Wallis test which revealed statistically significant differences ( p  < 0.05). Post-hoc pairwise comparisons using the Mann-Whitney U test showed that fourth-year students had significantly higher perception scores than both fifth- and sixth-year students ( p  < 0.05). Although perceptions improved slightly in the sixth year, these differences were not statistically significant. Strong positive correlations were observed among the survey variables ( p  < 0.001), but no significant correlations were found between portfolio perceptions and academic performance ( p  > 0.05). Conclusion The transition to outcome-based education may be associated with poor portfolio perceptions. Adjusting workload, enhancing feedback, and integrating portfolios into the curriculum may improve portfolio acceptability.

Despite the widespread use of portfolios in medical education, their outcomes remain variable. This study evaluated students' perceptions of portfolios at an institution that recently adopted an outcome-based curriculum. This descriptive cross-sectional study involved 4th, 5th, and 6th -year medical students (n = 94; response rate = 64.8%) at Prince Sattam Bin Abdulaziz University, Saudi Arabia, during the 2023-2024 academic year. A 13-item Likert-type questionnaire assessed students' portfolio perceptions across five domains: design, feedback and reflection, benefits in assessment, openness to their broader use in the college, and usefulness. Students' Grade Point Average (GPA) was also recorded as an index of academic performance. Data were analyzed quantitatively; results were expressed as frequencies, means, medians, and percentages. Correlation analyses were conducted to explore the relationships between overall portfolio perception and other measured domains. Ninety four students participated in this study. Only 48.9% of students found portfolios useful, with neutral average score of 3.3 ± 1.4 on the Likert scale and 5.66 ± 2.7 on the visual scale. Fewer than half reported positive perceptions across the five assessed domains. Differences in perceptions across academic levels were analyzed using the Kruskal-Wallis test which revealed statistically significant differences (p < 0.05). Post-hoc pairwise comparisons using the Mann-Whitney U test showed that fourth-year students had significantly higher perception scores than both fifth- and sixth-year students (p < 0.05). Although perceptions improved slightly in the sixth year, these differences were not statistically significant. Strong positive correlations were observed among the survey variables (p < 0.001), but no significant correlations were found between portfolio perceptions and academic performance (p > 0.05). The transition to outcome-based education may be associated with poor portfolio perceptions. Adjusting workload, enhancing feedback, and integrating portfolios into the curriculum may improve portfolio acceptability.

Acetic acid is by-product from fermentation processes for producing succinic acid using Mannheimia succiniciproducens. To obtain pure succinic acid from the final fermentation broth, acetic acid was selectively removed based on the different extractability of succinic acid and acetic acid with pH using tri-n-octylamine (TOA) as extractant. When successive batch extractions were performed using 0.25 mol TOA kg(-1) dissolved in 1-octanol at pH 5, the mol ratio of succinic acid to acetic acid before extraction was 4.9 and the final ratio after the fourth batch was 9.4.

Glycoprotein gene gB, gC and gD of pseudorabies virus (PrV) strain Ea, which was isolated locally in Wuhan, were cloned from the viral genome DNA and expressed in vitro controlled by the major immediately-early promotor/enhancer of HCMV. In the presented paper, Balb/c mice, rabbits and piglets were vaccinated intramuscularly two times at 2-week interval with those eukaryotic expression plasmid pcDB, pcDC and pcDD, respectively. The animals injected with pcDB, pcDC, pcDD or mix DNA developed anti-PrV antibodies. Neutralizing antibody titers obtained 2–5 log 2, 2 weeks after the second vaccination. Cellular immune responses were also detected by lymphoproliferation assay and cytotoxic T lymphocyte (CTL) activity assay in all groups vaccinated with DNA. Immune responses elicited by DNA vaccines provided protections with different degrees against lethal dose PrV challenge. In mice, protections induced by pcDC, pcDD or mix DNA were 100%, similar to that by inactivated vaccine. Protections were more than 50% induced by pcDC, pcDD or mix DNA in rabbits. Protections induced by pcDB were the lowest among DNA immunization in mice or rabbits. However, pcDB could elicit the higher cellular responses in rabbits or piglets. In piglets, body temperatures of animals injected with pcDB, pcDC, pcDD or mix DNA did not change significantly after challenge with 2×10 5 pfu of PrV strain Ea, and the means daily growth post-challenge of those animals were higher than those injected with inactivated vaccine or parental plasmid. Neither DNA vaccines nor inactivated vaccine could prevent or delay virus excretion after challenge. Our experiments in experimental animals and natural hosts suggested the efficiency and potential application of DNA vaccines for pseudorabies in pigs.

Predispersed solvent extraction (PDSE) of succinic acid with Tri-n-octylamine (TOA) dissolved in 1-octanol from aqueous solutions of 50 g/L succinic acid was examined. It was found that the equilibrium data in PDSE was equal to that in conventional solvent extraction in spite of the lack of mechanical mixing in PDSE. The influence of salts on succinic acid extraction and the stability of colloidal liquid aphrons (CLAs) were also investigated. Results indicated that in the presence of sodium chloride, less succinic acid was extracted by CLAs and the stability of CLAs decreased. However, the stability of CLAs was sufficient to make PDSE practically applicable to real fermentation broth, considering the concentration range of salts in the fermentation process for succinic acid.

In production of succinic acid by fermentation, succinic acid and acetic acid are co-produced. To purify the succinic acid from binary-acid mixture of succinic acid and acetic acid, the tertiary amine-based extraction was used. In 1-octanol, the selectivity for succinic acid was proportional to the chain length of tertiary amine. But, the distribution of acids into organic phase was low in n-heptane. These results are due to the different degree of intramolecular hydrogen bonding of succinic acid and hydrophobicity of each acid.[PUBLICATION ABSTRACT]

The Oligomeric proanthocyanidin (OPC) in green and black tea, grape seeds, grapes and wine has raised much attention but that OPC in wild grape seed remains to be intensively investigated. This study investigated the total OPC contents and total antioxidant activity of wild grape seeds and developed an efficient extraction process with various temperatures, solvent compositions and times. Also, a chromatography column packed with the Dia-ion HP-20 resin was used for further purification of the OPC. The total OPC contents were determined with the Folin-Ciocalteu reagent, and the antioxidant activity using total antioxidant potential (TAP) and 1,1-diphenyl-2picrylhydrazyl (DPPH). The yield of final purified OPC was 1.78 (+)-catechin equivalent (CE) g/100 g, with IC^sub 50^ activities of TAP and DPPH of 31.60 and 15.70 μg/mL. These activities of the final purified OPC were about two times higher than that of the BHA used as a reference sample.[PUBLICATION ABSTRACT]

A study of the PDSE (predispersed solvent extraction) for succinic acid by colloidal liquid aphrons was conducted. The organic phase contaning TOA (tri-n-octylamine) and 1-octanol permits a selective extraction of succinic acid from its aqueous solution. There was no difference of the extractability of PDSE and that of conventional mixer-settler type extraction. Taking into account the no mechanical mixing in PDSE, it was concluded that the PDSE process is more adaptive than the conventional mixer-settler type extraction process. From mass transfer analysis at the various concentration of TOA in counter-current continuous operation, the concentration of TOA had no influence on the mass transfer coefficient. The loading values in continuous PDSE were almost same as those in batch operation.

Colloidal liquid aphrons (CLAs) are surfactant-stabilized solvent droplets which have recently been explored for predispersed solvent extraction (PDSE). We have compared the equilibrium distribution of lactic acid with solvent alone and with CLAs. In spite of the short contact time in the PDSE process with CLAs, there was little difference in equilibrium distribution with solvent alone. The toxicity of extractants and diluents on Lactobacillus rhamnosus was measured for in situ extraction. Long chain alcohols such as 1-octanol and 1-decanol were less toxic among diluents. CLAs reduced the toxicity of solvents on Lactobacillus rhamnosus.[PUBLICATION ABSTRACT]

Stevens-Johnson syndrome and the related disease toxic epidermal necrolysis are life-threatening reactions of the skin to particular types of medication. Here we show that there is a strong association in Han Chinese between a genetic marker, the human leukocyte antigen HLA-B*1502, and Stevens-Johnson syndrome induced by carbamazepine, a drug commonly prescribed for the treatment of seizures. It should be possible to exploit this association in a highly reliable test to predict severe adverse reaction, as well as for investigation of the pathogenesis of Stevens-Johnson syndrome.