Influence of beveling and ultrasound application on marginal adaptation of box-only Class II (slot) resin composite restorations

A laboratory study was performed to assess the influence of beveling the margins of cavities and the effects on marginal adaptation of the application of ultrasound during setting and initial light curing. After minimal access cavities had been prepared with an 80 microm diamond bur, 80 box-only Class II cavities were prepared mesially and distally in 40 extracted human molars using four different oscillating diamond coated instruments: (A) a U-shaped PCS insert as the non-beveled control (EMS), (B) Bevelshape (Intensiv), (C) SonicSys (KaVo) and (D) SuperPrep (KaVo). In groups B-D, the time taken for additional bevel finishing was measured. The cavities were filled with a hybrid composite material in three increments. Ultrasound was also applied to one cavity per tooth before and during initial light curing (10 seconds). The specimens were subjected to thermomechanical stress in a computer-controlled masticator device. Marginal quality was assessed by scanning electron microscopy and the results were compared statistically. The additional time required for finishing was B > D > C (p < or = 0.05). In all groups, thermomechanical loading resulted in a decrease in marginal quality. Beveling resulted in higher values for "continuous" margins compared with that of the unbeveled controls. The latter showed better marginal quality at the axial walls when ultrasound was used. Beveling seems essential for good marginal adaptation but requires more preparation time. The use of ultrasonic vibrations may improve the marginal quality of unbeveled fillings and warrants further investigation.

Structural analysis of B-Box 2 from MuRF1: identification of a novel self-association pattern in a RING-like fold

The B-box motif is the defining feature of the TRIM family of proteins, characterized by a RING finger-B-box-coiled coil tripartite fold. We have elucidated the crystal structure of B-box 2 (B2) from MuRF1, a TRIM protein that supports a wide variety of protein interactions in the sarcomere and regulates the trophic state of striated muscle tissue. MuRF1 B2 coordinates two zinc ions through a cross-brace alpha/beta-topology typical of members of the RING finger superfamily. However, it self-associates into dimers with high affinity. The dimerization pattern is mediated by the helical component of this fold and is unique among RING-like folds. This B2 reveals a long shallow groove that encircles the C-terminal metal binding site ZnII and appears as the defining protein-protein interaction feature of this domain. A cluster of conserved hydrophobic residues in this groove and, in particular, a highly conserved aromatic residue (Y133 in MuRF1 B2) is likely to be central to this role. We expect these findings to aid the future exploration of the cellular function and therapeutic potential of MuRF1.

Selective pharmacological targeting of a DEAD box RNA helicase

RNA helicases represent a large family of proteins implicated in many biological processes including ribosome biogenesis, splicing, translation and mRNA degradation. However, these proteins have little substrate specificity, making inhibition of selected helicases a challenging problem. The prototypical DEAD box RNA helicase, eIF4A, works in conjunction with other translation factors to prepare mRNA templates for ribosome recruitment during translation initiation. Herein, we provide insight into the selectivity of a small molecule inhibitor of eIF4A, hippuristanol. This coral-derived natural product binds to amino acids adjacent to, and overlapping with, two conserved motifs present in the carboxy-terminal domain of eIF4A. Mutagenesis of amino acids within this region allowed us to alter the hippuristanol-sensitivity of eIF4A and undertake structure/function studies. Our results provide an understanding into how selective targeting of RNA helicases for pharmacological intervention can be achieved.

The Right to Be Forgotten More Than a Pandora’s Box?

Recently, political voices have stressed the need to introduce a right to be forgotten as new human right. Individuals should have the right to make potentially damaging information disappear after a certain time has elapsed. Such new right, however, can come in conflict with the principle of free speech. Therefore, its scope needs to be evaluated in the light of appropriate data protection rules. Insofar, a more user-centered approach is to be realized. “Delete” can not be a value as such, but must be balanced within a new legal framework.

Cloth-covered Clamshell Music Box

Unbound sheet music and an audio CD of a live performance of the sheet music. GoalTo design an aesthetically cohesive binding and housing for the materials. TreatmentThe sheet music was bound as a double-fan adhesive with cloth-covered case binding. The bound volume and audio CD were housed together in a cloth-covered clamshell box with Volara foam insert.

Beanie Box

Iowa State University freshman beanie, c. 1918. GoalTo design a housing which would support and protect the beanie, and would also allow the beanie to be viewed without being handled. TreatmentA custom, cloth-covered box with Velcro-supported, drop-down sides was constructed to fit the dimensions of a museum-quality hat stand.

Clamshell box for miniature book

Miniature artist's book. Goal To create standard size housing for miniature books so that they can be shelved with the collection. Treatment Based on a standard size, a clamshell box with foam filler was created to house a miniature artist's book. Cotton tape secured beneath the foam was added to gently lift the book from the foam insert.

Artifact exhibit and storage box

Plaster death mask. Goal To design a box that can store and exhibit the death mask without requiring the removal or re-positioning of the mask. Treatment A custom, cloth-covered box with a drop-front was constructed to fit the dimensions of the mask and foam filler. Foam was carved to accommodate the mask and then covered with unbleached muslin.

Laparoscopic-Simulator Box: a Simple Design for Surgical Residency Programs to Improve Trainees’ Laparoscopic Skills

Introduction: Since the introduction and evolution of laparoscopic surgery, there have been some concerns related to surgical training in this field. Laparoscopic box trainers and virtual simulators appear as useful devices which have been demonstrating effectiveness in learning surgical skills. However, these tools remain inaccessible for many centers around the world. Our intent is to share our experience in successful design to inspire others in surgical residency programs to build such boxes for training in laparoscopic techniques and also to encourage the use of simulators in educational centers. [See PDF for complete abstract]

The molecular and genetic characterization of the MADS box transcription factor {\it Drosophila\/} MEF2

The myocyte enhancer factor (MEF)-2 family of transcription factors has been implicated in the regulation of muscle transcription in vertebrates, but the precise position of these regulators within the genetic hierarchy leading to myogenesis is unclear. The MEF2 proteins bind to a conserved A/T-rich DNA sequence present in numerous muscle-specific genes, and they are expressed in the cells of the developing somites and in the embryonic heart at the onset of muscle formation in mammals. The MEF2 genes belong to the MADS box family of transcription factors, which control specific programs of gene expression in species ranging from yeast to humans. Each MEF2 family member contains two highly conserved protein motifs, the MADS domain and the MEF2-specific domain, which together provide the MEF2 factors with their unique DNA binding and dimerization properties. In an effort to further define the function of the MEF2 proteins, and to evaluate the degree of conservation shared among these factors and the phylogenetic pathways that they regulate, we sought to identify MEF2 family members in other species. In Drosophila, a homolog of the vertebrate MEF2 genes was identified and termed D-mef2. The D-MEF2 protein binds to the consensus MEF2 element and can activate transcription through tandem copies of that site. During Drosophila embryogenesis, D-MEF2 is specific to the mesoderm germ layer of the developing embryo and becomes expressed in all muscle cell types within the embryo. The role of D-mef2 in Drosophila embryogenesis was examined by generating a loss-of-function mutation in the D-mef2 gene. In embryos homozygous for this mutant allele, somatic, cardiac, and visceral muscles fail to differentiate, but precursors of these myogenic lineages are normally specified and positioned. These results demonstrate that different muscle cell types share a common myogenic differentiation program controlled by MEF2 and suggest that this program has been conserved from Drosophila to mammals. ^