Digital Workflow for Retrofitting a Surveyed Crown Using a Removable Partial Denture as an Antagonist

Digital workflow expedites the procedure of retrofitting a surveyed crown against an existing removable partial denture (RPD). This article describes a simple and straightforward technique of digital workflow where an existing RPD is scanned as an antagonist to design the rest seat, guide plane, and height of contour of a surveyed crown.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156192/2/jopr13187_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156192/1/jopr13187.pd

Performance Improvement of a High Side Scroll Compressor by Thrust Surface Oil Groove

Performance analysis has been carried out on a high side scroll compressor having a fixed scroll equipped with a circular oil groove on its thrust surface. Oil is supplied to the oil groove through an intermittent opening from a high pressure oil reservoir formed inside the orbiting scroll hub. Oil in the groove is then delivered to both suction and back pressure chambers by pressure differentials and viscous pumping action of the orbiting scroll base plate. Mathematical modeling of this oil groove system has been incorporated into main compressor performance simulation program for optimum oil groove design. Pressure in the oil groove can be controlled by changing the oil passage area and oil groove configuration. With an enlarged oil passage, pressure in the oil groove increases due to increased flow rate, but pressure increase in the back pressure chamber is not that large, resulting in reduced friction loss at the thrust surface between the two scrolls. On the other hand, by increasing the oil passage area, oil content in the refrigerant flow increases, and the orbiting scroll stability could be negatively affected by oil groove pressure increase. Considering all these factors, EER could be improved by about 3.6% at ARI condition by optimum oil groove design

Impact factor of Korean Journal of Pediatrics on Korean Medical Citation Index and Science Citation Index of Web of Science

PurposeThe total number of times a paper is cited, also known as the impact factor (IF) of a medical journal, is widely implied in evaluating the quality of a research paper. We evaluated the citation index data as an IF of Korean J Pediatr in Korean Medical Citation Index (KoMCI) and JCI of Web of Science.MethodsWe calculated the IF of Korean J Pediatr at KoMCI supervised by Korean Association of Medical Journal Editors. And we estimated the IF of Korean J Pediatr by the JCI of Web of Science although it was never officially reported.ResultsThe IF of Korean J Pediatr on KoMCI has increased from 0.100 in the year 2000, to 0.205 in 2008, and 0.326 in 2009. Although the IF of Korean J Pediatr was 0.006 in 2005, 0.018 in 2006, 0.028 in 2008, 0.066 in 2009, and 0.018 in 2010 according to the JCI of Web of Science, the number of citations are steadily increasing.ConclusionUnderstanding and realizing the current status will be a stepping stone for further improvement. The next objective of the Korean J Pediatr is to become registered in the SCI or SCIE. Increasing the IF according to the JCI of Web of Science is crucial in order to achieve this goal

Associations between Organochlorine Pesticides and Vitamin D Deficiency in the U.S. Population

Background: Recently low dose organochlorine (OC) pesticides have been strongly linked to various chronic diseases including diabetes and cardiovascular diseases. Both field and animal studies have suggested a possibility that persistent lipophilic chemicals like OC pesticides can cause vitamin D deficiency, but there have been no human studies of exposure to any chemical as a possible cause of vitamin D deficiency. This study was performed to examine if serum concentrations of OC pesticides were associated with serum concentrations of 25-hydroxyvitamin D (25(OH)D) in the U.S. general population. Methodology/Principal Findings: Cross-sectional associations of serum OC pesticides with serum 25(OH)D were investigated in 1,275 subjects aged $20 in the National Health and Nutrition Examination Survey(NHANES), 2003–2004. We selected 7 OC pesticides detectable in$80 % of participants. Among the 7 OC pesticides, p,p9-DDT (b = 20.022, P,0.01), p,p9-DDE (b = 20.018, P = 0.04), and b-hexachlorocyclohexane (b = 20.022, P = 0.02) showed significant inverse associations with serum 25(OH)D levels. When study subjects were stratified by age, race, and the presence of various chronic diseases, p,p9-DDT showed consistent inverse associations in all subgroups, although stronger associations tended to be observed among subjects with old age, white race, or chronic diseases. Conclusion/Significance: The current study suggests that the background exposure to some OC pesticides leads to vitamin D deficiency in human. Considering the importance of vitamin D deficiency in the development of chronic diseases

Selective disruption of an oncogenic mutant allele by CRISPR/Cas9 induces efficient tumor regression

Approximately 15% of non-small cell lung cancer cases are associated with a mutation in the epidermal growth factor receptor (EGFR) gene, which plays a critical role in tumor progression. With the goal of treating mutated EGFR-mediated lung cancer, we demonstrate the use of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein 9 (Cas9) system to discriminate between the oncogenic mutant and wild-type EGFR alleles and eliminate the carcinogenic mutant EGFR allele with high accuracy. We targeted an EGFR oncogene harboring a single-nucleotide missense mutation (CTG > CGG) that generates a protospacer-adjacent motif sequence recognized by the CRISPR/Cas9 derived from Streptococcus pyogenes. Co-delivery of Cas9 and an EGFR mutation-specific single-guide RNA via adenovirus resulted in precise disruption at the oncogenic mutation site with high specificity. Furthermore, this CRISPR/Cas9-mediated mutant allele disruption led to significantly enhanced cancer cell killing and reduced tumor size in a xenograft mouse model of human lung cancer. Taken together, these results indicate that targeting an oncogenic mutation using CRISPR/Cas9 offers a powerful surgical strategy to disrupt oncogenic mutations to treat cancers; similar strategies could be used to treat other mutation-associated diseases.

Effects of dodecacalcium heptaaluminate content on the setting time, compressive strength, alkalinity, and cytocompatibility of tricalcium silicate cement

Objective: This study aimed to investigate the effects of dodecacalcium hepta-aluminate (C12A7) content on some physicochemical properties and cytocompatibility of tricalcium silicate (C3S) cement using human dental pulp cells (hDPCs). Material and Methods: High purity C3S cement was manufactured by a solid phase method. C12A7 was mixed with the cement in proportions of 0, 5, 8, and 10 wt% (C12A7-0, -5, -8, and -10, respectively). Physicochemical properties including initial setting time, compressive strength, and alkalinity were evaluated. Cytocompatibility was assessed with cell viability tests and cell number counts. Statistical analysis was performed by using one-way analysis of variance (ANOVA) and Tukey’s test (p<0.05). Results: The initial setting time of C3S-based cement was shorter in the presence of C12A7 (p<0.05). After 1 day, C12A7-5 showed significantly higher compressive strength than the other groups (p<0.05). After 7 days, the compressive strength of C12A7-5 was similar to that of C12A7-0, whereas other groups showed strength lower than C12A7-0. The pH values of all tested groups showed no significant differences after 1 day (p>0.05). The C12A7-5 group showed similar cell viability to the C12A7-0 group (p>0.05), while the other experimental groups showed lower values compared to C12A7-0 group (p<0.05). The number of cells grown on the C12A7-5 specimen was higher than that on C12A7-8 and -10 (p<0.05). Conclusions: The addition of C12A7 to C3S cement at a proportion of 5% resulted in rapid initial setting time and higher compressive strength with no adverse effects on cytocompatibility

Large-scale preparation of active caspase-3 in E. coli by designing its thrombin-activatable precursors

<p>Abstract</p> <p>Background</p> <p>Caspase-3, a principal apoptotic effector that cleaves the majority of cellular substrates, is an important medicinal target for the treatment of cancers and neurodegenerative diseases. Large amounts of the protein are required for drug discovery research. However, previous efforts to express the full-length caspase-3 gene in <it>E. coli </it>have been unsuccessful.</p> <p>Results</p> <p>Overproducers of thrombin-activatable full-length caspase-3 precursors were prepared by engineering the auto-activation sites of caspase-3 precursor into a sequence susceptible to thrombin hydrolysis. The engineered precursors were highly expressed as soluble proteins in <it>E. coli </it>and easily purified by affinity chromatography, to levels of 10–15 mg from 1 L of <it>E. coli </it>culture, and readily activated by thrombin digestion. Kinetic evaluation disclosed that thrombin digestion enhanced catalytic activity (<it>k</it>_cat/<it>K</it>_<it>M</it>) of the precursor proteins by two orders of magnitude.</p> <p>Conclusion</p> <p>A novel method for a large-scale preparation of active caspase-3 was developed by a strategic engineering to lack auto-activation during expression with amino acid sequences susceptible to thrombin, facilitating high-level expression in <it>E. coli</it>. The precursor protein was easily purified and activated through specific cleavage at the engineered sites by thrombin, generating active caspase-3 in high yields.</p