The effect of frontal trauma on the edentulous mandible with four different interforaminal implant-prosthodontic anchoring configurations. A 3D finite element analysis

PURPOSE

The present three-dimensional (3D) finite element analysis (FEA) was aimed to assess the biomechanical effects and fracture risks of four different interforaminal implant-prosthodontic anchoring configurations exposed to frontal trauma.

MATERIAL AND METHODS

A symphyseal frontal trauma of 1 MPa was applied to four dental implant models with different configurations (two unsplinted interforaminal implants [2IF-U], two splinted interforaminal implants [2IF-S], four unsplinted interforaminal implants[ 4IF-U], four splinted interforaminal implants [4IF-S]. By using a 3D-FEA analysis the effective cortical bone stress values were evaluated in four defined regions of interest (ROI) (ROI 1: symphyseal area; ROI 2: preforaminal area; ROI 3: mental foraminal area; and ROI 4: condylar neck) followed by a subsequent intermodel comparison.

RESULTS

In all models the frontal traumatic force application revealed the highest stress values in the condylar neck region. In both models with a four-implant configuration (4IF-U, 4IF-S), the stress values in the median mandibular body (ROI 1) and in the condylar neck region (ROI 4) were significantly reduced (P <0.01) compared with the two-implant models (2IF-U, 2IF-S). However, in ROI 1, the model with four splinted implants (4IF-S) showed significantly (P < 0.01) reduced stress values compared to the unsplinted model (4IF-U). In addition, all models showed increased stress patterns in the area adjacent to the posterior implants, which is represented by increased stress values for both 2IF-U and 2IF-S in the preforaminal area (ROI 3) and for the four implant-based models (4IF-U, 4IF-S) in the mental foraminal area.

CONCLUSION

The configuration of four splinted interforaminal implants showed the most beneficial distribution of stress pattern representing reduced stress distribution and associated reduced fracture risk in anterior symphysis, condylar neck and preforaminal region.

Clinical, radiographic, and histological/histomorphometric analysis of maxillary sinus grafting with deproteinized porcine or bovine bone mineral: A randomized clinical trial

OBJECTIVE

The present study aimed to compare histomorphometrically evaluated new bone formation, radiographically measured graft stability, and clinical implant outcome between maxillary sinus grafting with either deproteinized porcine bone mineral (DPBM) or deproteinized bovine bone mineral (DBBM).

MATERIALS AND METHODS

Thirty maxillary sinuses were initially included and randomly assigned to the test group (TG; DPBM, n = 15) or control group (CG; DBBM, n = 15). After a healing period (6 months), axially retrieved bone biopsies of the molar region were used for histological/histomorphometric analysis of new bone formations. Additionally, radiographically measured graft stability and clinical implant outcome were assessed.

RESULTS

Twenty-three sinus sites with 10 sinuses of the TG and 13 of the CG were ultimately available for data and statistical analysis. In the TG, a slightly, but yet significantly (p = .040) higher proportion of new bone formation (TG: 27.7 ± 5.6% vs. CG: 22.9 ± 5.1%) and a lesser (p = .019) amount of connective (non-mineralized) tissue (TG: 47.5 ± 9.5% vs. CG: 56.1 ± 9.5%) was found than in the CG. However, both xenografts showed comparable (n.s.) residual bone graft (TG: 23.7 ± 7.2% vs. CG: 21.1 ± 9.85.6%), bone-to-graft contacts (TG: 26.2 ± 9.8% vs. CG: 30.8 ± 13.8%), similar graft height reduction over time (TG: 12.9 ± 6.7% CG: 12.4 ± 5.8%) and implant survival/success rate (100%). At the 3-year post-loading evaluation, the peri-implant marginal bone loss (TG: 0.52 ± 0.19 mm; CG: 0.48 ± 0.15 mm) and the peri-implant health conditions (TG: 87.5%/CG: 81.2%) did not differ between implants inserted in both xenografts used.

CONCLUSIONS

The use of DPBM or DBBM for maxillary sinus augmentation is associated with comparable bone formation providing stable graft dimension combined with healthy peri-implant conditions.

Erratum: Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande [Phys. Rev. Lett. 130, 031802 (2023)]

This corrects the article DOI: 10.1103/PhysRevLett.130.031802.

Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin 2 θ 13 and the impact of priors on the δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin 2 θ 13 from reactors, sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman-Cousins corrected intervals, and Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant Δ χ 2 intervals. The CP-violating phase is constrained to δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman-Cousins corrected intervals, and δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2 σ credible level using a flat prior in δ CP , and just below 2 σ using a flat prior in sin δ CP . When the external constraint on sin 2 θ 13 is removed, sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

Transsinusoidal lateral nasal floor augmentation for implant placement in the atrophic premaxilla: A within-patient, 5-year, prospective comparative study

OBJECTIVES

To evaluate the clinical outcome for implants placed with transsinusoidal-lateral nasal cavity augmentation (NA) compared to implants placed in maxillary sinus augmentation (SA).

MATERIALS AND METHODS

In 28 atrophic edentulous maxillary regions (14 patients bi-maxillary), a lateral window approach was used to perform transsinusoidal-lateral NA (TSLNA) combined with maxillary SA. After healing period of about 6 months, each patient received bimaxillary one anterior implant located in the pre-maxilla having lateral NA and 2-3 implants in the maxillary posterior region with SA. In a prospective follow-up evaluation, clinical implant outcome (survival/success rates) and peri-implant health (mucositis/peri-implantitis) were assessed and compared between implants placed in TSLNA (n = 28) and SA (n = 58).

RESULTS

At the year-1, year-3, and year-5 evaluation, neither patient-based nor implant-based comparisons revealed differences for marginal bone level reduction between implants placed in TSLNA (5-year overall: 1.11 ± 0.26 mm) and SA (5-year overall: 1.07 ± 0.30 mm), although with a significant (p < .001) continuous reduction over the observation time. At the year-5 evaluation, all implants (n = 86) and restorations (n = 14) were still in situ (survival 100%) and showed an implant-based incidence of peri-implant mucositis/peri-implantitis of 14.3%/0% in TSLNA and 6.9%/3.4% in SA corresponding to 21.4%/0% and 28.6%/7.1% for implant-based evaluation. In addition, the implant success rate did not differ between NA and SA at implant- (100%/ 98.8%) and patient-based (100%/97.6%) evaluation.

CONCLUSION

The findings obtained show TSLNA as an effective method for implant placement of adequate length and direction in the atrophic premaxilla providing for success rates comparable to those of implants placed in SA.

Efficacy of Labial Split-Thickness Eversion Periosteoplasty for Soft Tissue Management in Posterior Mandibular Horizontal Ridge Augmentation Procedures: A Prospective Clinical Study

Purpose: To evaluate the efficacy of split-thickness labial eversion periosteoplasty (EPP) for soft tissue closure in horizontal ridge augmentation of posterior mandibular regions using a bone shell onlay grafting technique. Materials and Methods: Sixteen patients (12 female and 4 male; mean age: 46.2 ± 8.7 years) with 18 horizontal bone defects in posterior mandibular regions were included for lateral onlay bone grafting using the bone shell technique. After lateral bone augmentation, the EPP was used for soft tissue closure and was prospectively followed up for wound healing efficacy using a modified scoring index. The scoring index included dichotomous (yes: 0 / no: 1) evaluation of the following items: (1) bleeding on palpation or spontaneously, (2) tissue color difference, (3) presence of hematoma, (4) presence of granulation tissue, (5) incomplete incision margin closure, (6) dehiscence with visible augmentation material, (7) presence of exudation, and (8) presence of suppuration. In addition, a visual analog scale (VAS) was used to quantify and record the amount of pain and swelling (0 = no pain/swelling and 5 = severe pain/swelling); VAS scores of 0, 1, and 2 were rated as 1 in the dichotomous scoring index, and VAS scores of 3, 4, and 5 were rated as 0. A summarized wound healing score consisting of all 10 items was assessed at days 2, 7, and 14 and at months 1 and 4 postoperatively, including a comparison of the follow-up evaluations. Results: The summarized healing score increased significantly (P < .01) between day 2 (score: 6.6 ± 1.1) and day 7 (score: 8.9 ± 1.0) but showed little difference between day 14 (score: 9.6 ± 0.6) and the 1- and 4-month follow-ups (score: 10.0 ± 0). There was no wound dehiscence and no incomplete incision margin adaptation. For the individual parameters evaluated, bleeding on palpation, hematoma, and exudation were the most frequent side effects at day 2 at 50%, 100%, and 22.2%, respectively, and at day 7 at 16.7%, 55.6%, and 22.2%, respectively. The average pain score and the swelling/edema score were initially 4.0 ± 0 and 3.0 ± 0.77 on day 2, with a significant decrease (P < .001) by day 7 (pain: 2.0 ± 0; edema/swelling: 2.0 ± 0.59) and day 14 (pain: 1.0 ± 0.42; edema/swelling: 2.0 ± 0.79) and complete absence (score: 0) at months 1 and 4. Conclusions: Labial split-thickness EPP facilitates flap advancement and enables tight soft tissue coverage in large horizontal posterior mandibular bone augmentations as a result of offset double-layer wound closure. Although this procedure is shown to be surgically demanding, the postoperative complication rate may be reduced significantly.

Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande

We report a search for cosmic-ray boosted dark matter with protons using the 0.37  megaton×years data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross section between 10^{-33}cm^{2} and 10^{-27}cm^{2} for dark matter mass from 1  MeV/c^{2} to 300  MeV/c^{2}.

Biopsies of osseous jaw lesions using 3D-printed surgical guides: a clinical study

Background

Bone biopsies are often necessary to make a diagnosis in the case of irregular bone structures of the jaw. A 3D-printed surgical guide may be a helpful tool for enhancing the accuracy of the biopsy and for ensuring that the tissue of interest is precisely removed for examination. This study was conducted to compare the accuracy of biopsies performed with 3D-printed surgical guides to that of free-handed biopsies.

Methods

Computed tomography scans were performed on patients with bony lesions of the lower jaw. Surgical guides were planned via computer-aided design and manufactured by a 3D-printer. Biopsies were performed with the surgical guides. Bone models of the lower jaw with geometries identical to the patients’ lower jaws were produced using a 3D-printer. The jaw models were fitted into a phantom head model and free-handed biopsies were taken as controls. The accuracy of the biopsies was evaluated by comparing the parameters for the axis, angle and depth of the biopsies to the planned parameters.

Results

Eight patients were included. The mean deviation between the biopsy axes was significantly lower in guided procedures than in free-handed biopsies (1.4 mm ± 0.9 mm; 3.6 mm ± 1.0 mm; p = 0.0005). The mean biopsy angle deviation was also significantly lower in guided biopsies than in free-handed biopsies (6.8° ± 4.0; 15.4° ± 3.6; p = 0.0005). The biopsy depth showed no significant difference between the guided and the free-handed biopsies.

Conclusions

Computer-guided biopsies allow significantly higher accuracy than free-handed procedures.

The influence of different forms of sinus membrane perforation on the prevalence of postoperative complications in lateral window sinus floor elevation: A retrospective study

BACKGROUND

Maxillary sinus membrane perforation (SMP) during lateral window sinus floor elevation (SFE) might be associated with postoperative complications (PC).

OBJECTIVES

To evaluate the prevalence of PC and clinical implant outcome for different forms of SMP with lateral window SFE.

MATERIAL AND METHODS

The prevalence of PC such as maxillary sinusitis, graft necrosis and wound infection was retrospectively evaluated for 434 lateral window SFE (334 patients) with 331 SFE (241 patients) without and 103 SFE (93 patients) with SMP. SMP was additionally classified into four subgroups regarding to membrane perforation size (small-moderate [<10 mm] vs. large [>10 mm]) and membrane biotype ([BT] thin vs. thick). Additionally, patient- and surgery-related risk factors affecting PC and the 1-year implant survival rate were evaluated for SFE without and with SMP and subgroups.

RESULTS

A significantly higher prevalence including significant odds ratios of PC such as maxillary sinusitis (10/103 [9.7%] vs. 4/331 [1.2%]; p < 0.021; OR: 8.85; p < 0.021) and graft necrosis (7/103[6.8%] vs. 1/103[0.3%]; p < 0.017; OR:7.43; p < 0.017) was found for SFE with than without SMP. The SMP subgroup with large size and thin BT involved significantly (p < 0.005) more PC (15/20[75%]) than all other SMP subgroups (5/20[25%]). For the risk factors evaluated the univariate analysis demonstrated differences of PC for the presence versus absence of SMP (p < 0.001) and for thin versus thick sinus mucosa (p < 0.038; p < 0.006) but not for sex, smoking, sinus septa and surgical stage. In the multivariate risk factors analysis, PC were significantly related to risk factors such as large size with thin BT (OR:18.049; p < 0.007). The 1-year implant survival rate did not differ between SFE without (99.5%) and with SMP (99.1%), regardless of successfully repaired subtype of SMP.

CONCLUSION

The synopsis of perforation size and membrane biotype is crucial in differentiating different forms of SMP assessing and anticipating different prevalences of PC in lateral window SFE.

Immediately loaded implants simultaneously placed in fresh extraction and healed sites supporting four-implant-supported fixed mandibular prostheses using the all-on-4 concept: A 5-year prospective study

OBJECTIVES

To evaluate the peri-implant marginal bone level for immediately loaded implants placed simultaneously in both fresh extraction sites (FES) and healed sites (HS) supporting a 4-implant supported mandibular fixed prosthesis (4-ISFMP) using the all-on-4 concept.

MATERIAL AND METHODS

A 5-year prospective study was conducted in 24 patients (96 implants) treated with 4-ISFMP including 55 implants inserted in FES and 41 implants in HS. At implant placement (baseline) and at the 1^st -, 3^rd - and 5^th -year follow-up examinations, peri-implant marginal bone level was evaluated radiographically and compared between placement in FES and HS. Marginal bone loss was calculated as the difference in the marginal bone level evaluated at the follow-up periods. Additionally, implant and prosthesis survival rates as well as the presence of peri-implant mucositis (bleeding on probing+[BOP]) and peri-implantitis (BOP+ >2 mm MBL) were evaluated.

RESULTS

22/24 patients with 88/96 implants (dropout rate: 8.3%) were continually followed for 5 years (survival rate: 100%). Radiographically measured marginal bone level differed significantly between FES and HS at implant placement (1.46 ± 0.80 mm vs. 0.60 ± 0.70 mm; p < .001), at the 1-year (-0.04 ± 0.14 mm vs. -0.18 ± 0.20 mm; p = .002) and 3-year (-0.26 ± 0.49 mm vs. -0.58 ± 0.48 mm, p = .049), but not at the 5-year evaluation (-0.90 ± 0.66 mm vs. -1.00 ± 0.59 mm, p = .361). The marginal bone loss differed significantly (p < .001) between FES and HS between implant placement and the 1-year evaluation but not for the 1- to 3-year (p > .99) and the 3- to 5-year period (p = .082). At the 5-year follow-up evaluation, no implant/prosthesis failed (100% survival) and peri-implant mucositis and peri-implantitis were noted in 41.2% and 11.7% at patient level and in 17.6% and 4.5% at implant level respectively.

CONCLUSION

Implants placed in FES showed a prolonged peri-implant remodelling process but provided for similar peri-implant marginal bone levels as implants placed in HS at the 5-year evaluation for immediately loaded 4-ISFMP.

Prevalence, risk factors, and repair mechanism of different forms of sinus membrane perforations in lateral window sinus lift procedure: A retrospective cohort study

OBJECTIVES

To evaluate prevalences, affecting risk factors and efforts for repair mechanism for different forms of sinus membrane perforations (SMP) during sinus floor elevation (SFE) using the lateral window technique (LWT).

MATERIAL AND METHODS

For 334/434 patients, SFE undergoing LWT prevalence of SMP was retrospectively evaluated including a subselection based on membrane perforation size (<10 mm: small-moderate/≥10 mm: large) and biotype (BT; thick BT/thin BT) into four subgroups (SMP1: thick BT/small-moderate; SMP2: thin BT/small-moderate; SMP3: thick BT/large; SMP4: thin BT/large). For the various subgroups, patient- and surgery-related/anatomic risk factors affecting SMP were evaluated and the scope of sinus membrane repair (SSMR) mechanisms rated with 1 (easy) to 5 (complex) was compared.

RESULTS

For 103/434 SMP (27.6%) in 93/334 patients (30.8%) the prevalence of various forms of SMP differed significantly (p < 0.001) among the four subgroups. SMP4 with a prevalence of 45.6% (n = 47) was the most frequent type, while SMP3 had low prevalence with 4.85% (n = 5). Small/moderate SMPs with thick (SMP1: n = 26) or thin BT (SMP2: n = 23) were seen in 26.2% and 23.3%, respectively. Univariate analysis showed significant differences between subgroups with large perforations (SMP3/SMP4) and those with small/moderate perforations (SMP1/SMP2) regarding anatomic risk factors such as residual ridge height (p = 0.023) and history of previous oral surgical interventions (OSI; p = 0.026). Most evidently, multivariate analysis showed that induction of large SMP with thin biotype (SMP4) was significantly affected by the presence of sinus septa (p < 0.022, OR: 2.415), reduced residual ridge height (p < 0.001, OR: 1.842), and previous OSI (p < 0.001, OR: 4.545). SSMR differed significantly (p < 0.001) between SMP4 (4.62 ± 0.49) and the subgroups SMP1 (1.11 ± 0.32), SMP2 (1.08 ± 028), and SMP3 (2.2 ± 0.55).

CONCLUSION

The most frequently found type of SMP had characteristics of thin biotype and large size associated with risk factors such as sinus septa, reduced residual ridge, and previous surgical interventions and required challenging repair mechanisms assessing clinical impact.

Cosmic Ray Background Removal With Deep Neural Networks in SBND

In liquid argon time projection chambers exposed to neutrino beams and running on or near surface levels, cosmic muons, and other cosmic particles are incident on the detectors while a single neutrino-induced event is being recorded. In practice, this means that data from surface liquid argon time projection chambers will be dominated by cosmic particles, both as a source of event triggers and as the majority of the particle count in true neutrino-triggered events. In this work, we demonstrate a novel application of deep learning techniques to remove these background particles by applying deep learning on full detector images from the SBND detector, the near detector in the Fermilab Short-Baseline Neutrino Program. We use this technique to identify, on a pixel-by-pixel level, whether recorded activity originated from cosmic particles or neutrino interactions.

In-house 3D-printed surgical guides for osseous lesions of the lower jaw: an experimental study

Background

The accuracy of computer-assisted biopsies at the lower jaw was compared to the accuracy of freehand biopsies.

Methods

Patients with a bony lesion of the lower jaw with an indication for biopsy were prospectively enrolled. Two customized bone models per patient were produced using a 3D printer. The models of the lower jaw were fitted into a phantom head model to simulate operation room conditions. Biopsies for the study group were taken by means of surgical guides and freehand biopsies were performed for the control group.

Results

The deviation of the biopsy axes from the planning was significantly less when using templates. It turned out to be 1.3 ± 0.6 mm for the biopsies with a surgical guide and 3.9 ± 1.1 mm for the freehand biopsies.

Conclusions

Surgical guides allow significantly higher accuracy of biopsies. The preliminary results are promising, but clinical evaluation is necessary.

Closure of the radial forearm free flap donor site with split-thickness skin graft or amniotic membrane: A prospective randomized clinical study

The purpose of this study was to compare the clinical, aesthetic, and functional outcomes between amniotic membrane (test group) and split-thickness skin grafts (control group) used for radial forearm free flap defect closure. The primary outcome measurement for both groups was assessment of the defect closure healing process. In addition, aesthetic (Vancouver Scar Scale) and functional outcomes (skin sensitivity, hand/wrist functionality, grip strength) were evaluated. Fifty eligible patients with radial forearm free flap donor site defects were randomly assigned to two groups receiving either amniotic membrane (test group; n = 25) or split-thickness skin graft (control group; n = 25) for defect covering. Forty-seven of the 50 patients (n = 47) were able to be followed up for 6 months and showed a significantly longer healing process (p < 0.001) with amniotic membrane (64.5 ± 38.4 days; n = 24) than with split-thickness skin grafts (29.2 ± 8.9 days; n = 23); however, there were no differences in the prevalence of healing defects/dehiscence and/or wound infections. Forty-two of the 47 patients (21 in each group) were able to be continually followed up for 12 months, and showed no differences in terms of clinical outcome as well as the subjective and objective aesthetic and functional results evaluated. With regard to the clinical, aesthetic, and functional outcomes evaluated for radial forearm free flap defects, coverage with amniotic membrane offers an excellent alternative treatment approach, avoiding secondary induced donor site morbidity.

Risk Factor Analysis Affecting Sinus Membrane Perforation During Lateral Window Maxillary Sinus Elevation Surgery

PURPOSE

To analyze risk factors affecting sinus membrane perforation (SMP) during sinus floor elevation (SFE) procedures using the lateral window technique (LWT).

MATERIALS AND METHODS

For patients with SFEs using the LWT, patient-related risk factors (age/sex/smoking/diabetes) and surgical-anatomical-related risk factors (stage approach/sinus side/residual ridge height/sinus membrane thickness/previous surgical interventions) were compared between perforated and nonperforated sites and were evaluated for their influence affecting SMP. Additionally, SMPs were further subdivided into small/moderate (< 10 mm) or large (≥ 10 mm) in dimension, which were also analyzed for risk factors and consecutively for their influence on perforation.

RESULTS

The study sample comprised 434 SFE procedures in 355 patients; 94/355 patients (26.5%) presented SMP in 103 of 434 SFE procedures (23.8%). SFE procedures with (n = 103) and without (n = 331) SMP did not differ for patient-related risk factors but differed significantly (P = .001) for surgical-anatomical factors as follows: residual ridge height (3.05 ± 1.35 mm vs 4.15 ± 1.46 mm), sinus membrane thickness (1.2 ± 0.5 mm vs 2.6 ± 1.1 mm), prevalence of staged procedures (78.6% vs 57.7%), presence of maxillary sinus septa (75.7% vs 14.2%), presence of thin (< 1.5 mm) mucosa biotype (62.1% vs 29%), and previous oral surgical interventions (37.9% vs 16.3%). In the multivariate analysis, significant associations of SMP were found with the presence of sinus septa (odds ratio [OR] = 31.992; P = .001), residual ridge height (OR = 1.563; P = .007), sinus membrane thickness (OR = 1.057; P = .001), presence of thin (< 1.5 mm) sinus biotype (OR = 8.883; P = .001), previous surgical interventions (OR = 4.689; P = .002), and smoking habits (OR = 2.238; P = .030). For inducing a large (≥ 10 mm) SMP, the presence of thin sinus membrane thickness/thin sinus membrane biotype (OR = 5.319; P = .006; OR = 22.222; P = .001) and reduced alveolar ridge height (OR = 0.629; P = .026) were assessed as being significant risk factors.

CONCLUSION

In general, the presence of sinus septa, thin sinus mucosa, staged procedures, and previous surgical interventions are the main risk factors inducing SMP for SFE using the LWT. In particular, the presence of thin sinus membrane in conjunction with a staged procedure significantly increases the risk for a large SMP.

Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

Atorvastatin enhances apoptotic effects of tamoxifen on melanoma cancer cells

AIM

Tamoxifen engages mitochondrial estrogen receptor beta as an antagonist, increases mitochondrial cytotoxicity and induces tumor cell death. Tamoxifen also engages plasma membrane estrogen receptor alpha as an agonist, while it is suggested that in some users its activation is put into action by mechanism of resistance to tamoxifen. Apoptotic inducers have been shown to promote tamoxifen-induced cell death, which might be of great importance in overcoming tamoxifen resistance. Considering the pleiotropic effects of statins, in the present study, we investigated the effects of atorvastatin on tamoxifen-induced intrinsic apoptotic pathway activity in melanoma cells.

METHODS

Melanoma B16F10 cells were treated for 24 and 48 h with various concentrations of tamoxifen, atorvastatin and combination of tamoxifen + atorvastatin. Cells with no treatment were considered a control group, and the study was then followed by quantitative RT- PCR assay. Bax and cytochrome c gene expressions were calculated by ΔΔct method.

RESULTS

Co-treatment of atorvastatin + tamoxifen could strongly enhance the expression of pro/apoptotic factors of Bax and cytochrome c in melanoma cells compared to the tamoxifen and atorvastatin groups.

CONCLUSION

In general, we conclude that the atorvastatin-induced increase in Bax and cytochrome c gene expression might be a permissive response to tamoxifen-induced cell death (Fig. 2, Ref. 37).

Clinical Outcome of Implants Placed in Staged Maxillary Sinus Augmentation Using Bovine Bone Mineral Mixed with Autogenous Bone at Three Different Ratios: A 5-Year Prospective Follow-up Study

PURPOSE

To evaluate the 5-year clinical outcomes for implants placed in a staged sinus floor elevation (SFE) procedure and to compare three patient groups with sinus grafts with three different ratios of bovine bone mineral (BBM) and autogenous bone (AB) mixture.

MATERIALS AND METHODS

A 5-year prospective cohort study was conducted on 81 patients with 119 staged SFEs non-randomly distributed to three groups based on the origin of the AB and the mixture ratio with BBM: group 1 (locally harvested AB [LHB] from osteotomy sites + BBM, ratio: 1:10), 31 patients, 37 SFEs; group 2: (LHB + intraorally harvested peripheral AB [IHPB] from retromolar/chin region + BBM, ratio: 1:4), 22 patients, 29 SFEs; and group 3 (LHB + extraorally harvested peripheral AB [EHPB] from iliac crest/tibia + BBM, ratio 1:1), 28 patients, 53 SFEs. After graft healing (5 to 7 months), 284 dental implants (group 1: 76, group 2: 61, group 3: 147 [overall: 2.3 implants/sinus]) were placed. After an additional healing period (5 to 7 months), all implants placed were functionally loaded and prospectively followed by clinical and radiographic evaluations assessing implant survival/success rate as well as peri-implant marginal bone level (MBL) alteration at 1, 3, and 5 years postloading.

RESULTS

A total of 76/81 patients with 267/284 implants were followed for up to 5 years (dropouts: 5 patients/15 implants; implant loss = 2). The 5-year implant survival and implant success rate (group 1: 100%/98.6%; group 2: 98.3%/96.6%; group 3: 99.3%/95.7%) did not differ between the three graft mixture groups. The peri-implant marginal bone alteration (reduction) averaged over all 5 years was 1.40 ± 0.29 mm for group 1, 1.41 ± 0.22 mm for group 2, and 1.46 ± 0.46 mm for group 3 (P = .187). However, over time, a continual and significant MBL reduction (P = .045) was noted for all groups presenting peri-implant MBL changes between 1 year and 5 years of -0.17 mm (group 1), -0.12 mm (group 2), and -0.24 mm (group 3), respectively.

CONCLUSION

According to the clinical results obtained, dental implants inserted in grafted (staged) SFE using a mixture of BBM with a minimal amount of AB harvested from local sites provide for similarly high 5-year implant/augmentation success rates as graft mixtures with AB harvested from peripheral intraoral or extraoral donor sites, confirming no need for additional bone harvesting.

Search for CP Violation in Neutrino and Antineutrino Oscillations by the T2K Experiment with 2.2×10^{21} Protons on Target

The T2K experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and antineutrino beams. With an exposure of 14.7(7.6)×10^{20} protons on target in the neutrino (antineutrino) mode, 89 ν_{e} candidates and seven anti-ν_{e} candidates are observed, while 67.5 and 9.0 are expected for δ_{CP}=0 and normal mass ordering. The obtained 2σ confidence interval for the CP-violating phase, δ_{CP}, does not include the CP-conserving cases (δ_{CP}=0, π). The best-fit values of other parameters are sin^{2}θ_{23}=0.526_{-0.036}^{+0.032} and Δm_{32}^{2}=2.463_{-0.070}^{+0.071}×10^{-3}  eV^{2}/c^{4}.

Characterization of an artificial skull cap for cranio-maxillofacial surgery training

Cranial grafts are favored to reconstruct skeletal defects because of their reduced resorption and their histocompatibility. Training possibilities for novice surgeons include the "learning by doing" on the patient, specimens or simulators. Although the acceptance of simulators is growing, the major drawback is the lack of validated bone models. The aim of this study was to create and validate a realistic skull cap model and to show superiority compared to a commercially available skull model. Characteristic forces during machinery procedures were recorded and thickness parameters from the bony layers were obtained. The thickness values of the bone layers of the developed parietal bone were comparable to the human ones. Differences between drilling and sawing forces of human and artificial bones were not detected using statistical analysis. In contrast the parameters of the commercially available skull model were significantly different. However, as a result, a model-based simulator for tabula externa graft lift training, consisting of a brain, skull bone cap and covering soft tissues was created. This simulator enables the training of all procedural steps of a "split thickness graft lift". In conclusion, an artificial skull cap suitable for parietal graft lift training was manufactured and validated against human parietal bones.

Regenerative endodontics: a comprehensive review

The European Society of Endodontology and the American Association for Endodontists have released position statements and clinical considerations for regenerative endodontics. There is increasing literature on this field since the initial reports of Iwaya et al. (Dental Traumatology, 17, 2001, 185) and Banchs & Trope (Journal of Endodontics, 30, 2004, 196). Endogenous stem cells from an induced periapical bleeding and scaffolds using blood clot, platelet rich plasma or platelet-rich fibrin have been utilized in regenerative endodontics. This approach has been described as a 'paradigm shift' and considered the first treatment option for immature teeth with pulp necrosis. There are three treatment outcomes of regenerative endodontics; (i) resolution of clinical signs and symptoms; (ii) further root maturation; and (iii) return of neurogenesis. It is known that results are variable for these objectives, and true regeneration of the pulp/dentine complex is not achieved. Repair derived primarily from the periodontal and osseous tissues has been shown histologically. It is hoped that with the concept of tissue engineering, namely stem cells, scaffolds and signalling molecules, that true pulp regeneration is an achievable goal. This review discusses current knowledge as well as future directions for regenerative endodontics. Patient-centred outcomes such as tooth discolouration and possibly more appointments with the potential for adverse effects needs to be discussed with patients and parents. Based on the classification of Cvek (Endodontics and Dental Traumatology, 8, 1992, 45), it is proposed that regenerative endodontics should be considered for teeth with incomplete root formation although teeth with near or complete root formation may be more suited for conventional endodontic therapy or MTA barrier techniques. However, much is still not known about clinical and biological aspects of regenerative endodontics.

Toward broadband, dynamic structuring of a complex plasmonic field

The ability to tailor a coherent surface plasmon polariton (SPP) field is an important step toward many new opportunities for a broad range of nanophotonic applications. Previously, both scanning a converging SPP spot and designing SPP profiles using an ensemble of spots have been demonstrated. SPPs, however, are normally excited by intense, coherent light sources, that is, lasers. Hence, interference between adjacent spots is inevitable and will affect the overall SPP field distributions. We report a reconfigurable and wavelength-independent platform for generating a tailored two-dimensional (2D) SPP field distribution by considering the coherent field as a whole rather than as individual spots. With this new approach, the inherent constraints in a 2D coherent field distribution are revealed. Our design approach works not only for SPP waves but also for other 2D wave systems such as surface acoustic waves.

Validation of a simulator for cranial graft lift training: Face, content, and construct validity

PURPOSE

Surgical skills can be improved through practical exercise. The use of specimens, human as well as animal, or live animals for surgical training is limited due to ethical concerns. Drawbacks of simulators are costs, fidelity and creditibility. Thus, simulators must be evaluated objectively to determine their validity before they can be used as teaching modalities. The aim of this study was to verify the face content and construct validity of a novel model-based simulator for lifting tabula externa transplants from the parietal skull.

MATERIALS AND METHODS

Participants were invited to perform a tabula externa graft lift during a training session on the simulator. Task performance was analyzed with a standardized assessment tool evaluating realism and appropriateness. Specialist ratings were used to evaluate the performance of the participants. This was an exploratory study using a questionnaire, at Kepler University Hospital, Linz, Austria, a university hospital. According to their expertise in craniomaxillofacial surgery, 17 participants were subdivided into 3 groups: 8 novices, 7 experts and 2 raters.

RESULTS

The face validity (realism) obtained an average score of 4.2 of a maximum of 5 points. Likewise, the content validity (appropriateness as a teaching modality) obtained an average score of 4.8 of maximum 5 points. No differences were found between experts and novices concerning the recorded surgery completion times (p = 0.418) or the sizes of the lifted grafts (p = 0.110). During the evaluation of task performance, the expert surgeons (46.9 ± 3.7) were graded significantly better than the novices (36.4 ± 8.5), which proved the construct validity of the simulator (p = 0.001).

CONCLUSION

All investigated validities were confirmed and approved the simulator as a valid training tool for parietal graft lift.

Abstract P2-03-03: A multicenter clinical study of Xpert® breast cancer STRAT4 demonstrates high concordance with central lab ER, PgR, HER2, and Ki67 IHC and HER2 FISH tests in FFPE breast tumor tissues

The Xpert® Breast Cancer STRAT4 (STRAT4) is a CE-IVD marked, semi-quantitative, cartridge-based RT-qPCR assay for the detection of ESR1, PGR, ERBB2 (HER2), and MKi67 mRNAs from formalin fixed, paraffin embedded (FFPE) breast tumors. The assay is fast (&lt; 2 hrs), reproducible, robust, and easy to perform.

The aim of this multicenter clinical study was to assess the performance characteristics of the STRAT4 assay relative to central lab immunohistochemistry (IHC) for ER, PgR, HER2, and Ki67 and to fluorescence in situ hybridization (FISH) for HER2 gene amplification.

Methods: A total of 200 archived primary invasive breast cancer FFPE blocks were sourced from Indivumed for this study. From each block, twelve (12) adjacent tissue sections (4-µm thickness) on slides were prepared for pathological H&E confirmation to define tumor area, and for testing by STRAT4, IHC (ER, PgR, HER2,Ki67), and HER2 FISH. Standard STRAT4 lysate preparation using a single unstained slide per specimen and testing on N=84, N=68, and N=48 samples was performed at 3 independent sites, respectively (2 US and 1 EU). A single slide from each specimen was also processed using the recommended concentrated lysate procedure for STRAT4 testing at Cepheid. All IHC and FISH testing was performed by a central academic reference laboratory in the US. For a given sample, STRAT4 data generated using the standard lysate procedure was included for concordance analysis when all target gene test results were valid. In cases where the standard lysate preparation yielded indeterminate test results for any target, data from the concentrated lysate preparation was used for the data analysis. Receiver Operating Characteristic (ROC) analysis, overall percent agreement (OPA), positive percent agreement (PPA), and negative percent agreement (NPA) between STRAT4 and IHC (IHC/FISH for HER2) were determined for ESR1,PGR, ERBB2, and MKi67.

Results: Of the 200 samples tested by STRAT4, all samples generated valid results for ESR1 and ERBB2, 199 of 200 samples were valid for PGR, and 198 of 200 samples were valid for MKi67 using the standard or concentrated lysate preparation protocol. One sample failed to generate results for both ER and PgR IHC. Twelve samples failed to yield HER2 FISH results.

The STRAT4 success rate and results concordance with IHC were comparable across study sites. OPA between STRAT4 and IHC was 97% for ESR1, 88.9% for PGR, 93.3% for HER2 (92.4% for IHC and FISH), and 90.7% for MKi67 (excluding IHC 10-20% staining). Areas under the ROC curves were 0.9922 for ESR1, 0.9509 for PGR, 0.9958 for ERBB2, and 0.9395 for MKi67.

Conclusion: STRAT4 measurements for ESR1, PGR, ERBB2 and MKi67 mRNA expression are robust and highly concordant with IHC (IHC/FISH for HER2). The technical portion of the assay is easily performed in &lt; 2 hrs including hands-on time using standard FFPE tissue sections. Xpert STRAT4 offers local pathology labs an alternative to centralized, subjective IHC/FISH tests that require a higher level of expertise. Further investigations correlating STRAT4 markers directly with clinical outcomes in independent cohorts are in progress.

Citation Format: Wu NC, Wong E, Acca B, Birkmeier J, Tran L, Zhao S, Wong W, Chu VC, Ho K, Malek M, Lu C, Ge G, David K, Quigley NB, Beqaj SS, Davenport S, Weidler J, Bates M, Press M. A multicenter clinical study of Xpert® breast cancer STRAT4 demonstrates high concordance with central lab ER, PgR, HER2, and Ki67 IHC and HER2 FISH tests in FFPE breast tumor tissues [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-03-03.

Protective effect of gastric distension preconditioning on renal ischemia/reperfusion injury in rats

The stomach mechanoreceptors can be stimulated by gastric distension (GD) and through afferent vagal nerve, increased activity of the renal sympathetic pathways. Because renal sympathectomy can abolish the protective effect of ischemic preconditioning, it seems that GD preconditioning can be effective in renal ischemia/reperfusion (I/R) injury. Gastric inflate (8 ml of 37°C water for 20 min) by a latex balloon inserted into the stomach through the fundus; I/R group was subjected to 45 min of bilateral ischemia and 24 h of reperfusion. GD preconditioning decreases blood urea nitrogen, creatinine, kidney damage score, and alkaline phosphatase levels compared to the sham GD group (P < 0.05). GD preconditioning may protect renal I/R injury through anti-inflammatory activity, but this efficacy requires extensive studies on the methods and mechanisms.

Measurements of the associated production of a Z boson and b jets in pp collisions at s = 8 TeV

Measurements of the associated production of a Z boson with at least one jet originating from a b quark in proton-proton collisions ats = 8 TeV are presented. Differential cross sections are measured with data collected by the CMS experiment corresponding to an integrated luminosity of 19.8fb - 1 . Z bosons are reconstructed through their decays to electrons and muons. Cross sections are measured as a function of observables characterizing the kinematics of the b jet and the Z boson. Ratios of differential cross sections for the associated production with at least one b jet to the associated production with any jet are also presented. The production of a Z boson with at least two b jets is investigated, and differential cross sections are measured for the dijet system. Results are compared to theoretical predictions, testing two different flavour schemes for the choice of initial-state partons.

Gold nanoparticles partition to and increase the activity of glucose-6-phosphatase in a synthetic phospholipid membrane system

Engineered nanomaterials can alter the structure and/or function of biological membranes and membrane proteins but the underlying mechanisms remain unclear. We addressed this using a Langmuir phospholipid monolayer containing an active transmembrane protein, glucose-6-phosphatase (G6Pase). Gold nanoparticles (nAu) with varying ligand shell composition and hydrophobicity were synthesized, and their partitioning in the membrane and effects on protein activity characterized. nAu incorporation did not alter the macroscopic properties of the membrane. Atomic force microscopy showed that when co-spread with other components prior to membrane compression, nAu preferentially interacted with G6Pase and each other in a functional group-dependent manner. Under these conditions, all nAu formulations reduced G6Pase aggregation in the membrane, enhancing catalytic activity 5-6 fold. When injected into the subphase beneath pre-compressed monolayers, nAu did not affect G6Pase activity over 60 minutes, implying they were unable to interact with the protein under these conditions. A small but significant quenching of tryptophan fluorescence showed that nAu interacted with G6Pase in aqueous suspension. nAu also significantly reduced the hydrodynamic diameter of G6Pase in aqueous suspension and promoted catalytic activity, likely via a similar mechanism to that observed in co-spread monolayers. Overall, our results show that nAu can incorporate into membranes and associate preferentially with membrane proteins under certain conditions and that partitioning is dependent upon ligand shell chemistry and composition. Once incorporated, nAu can alter the distribution of membrane proteins and indirectly affect their function by improving active site accessibility, or potentially by changing their native structure and distribution in the membrane.

Combined Analysis of Neutrino and Antineutrino Oscillations at T2K

T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January 2010 to May 2016 and comprise 7.482×10^{20} protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135  μ-like events, and 7.471×10^{20} protons on target in antineutrino mode, which yielded 4 e-like and 66  μ-like events. Reactor measurements of sin^{2}2θ_{13} have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δ_{CP} spans the range (-3.13, -0.39) for normal mass ordering. The CP conservation hypothesis (δ_{CP}=0, π) is excluded at 90% C.L.

Abstract P1-03-11: Analytical validation for the RT-qPCR based multiplex mRNA measurements of ER, PgR, HER2, and Ki67 from FFPE tumor tissue using the GeneXpert breast cancer stratifier assay

BACKGROUND: Accurate assessment of ER, PgR, HER2 and Ki67 status is crucial for breast cancer therapy and patient management. Immunohistochemistry (IHC) assays have been standard diagnostic tools but they are complex and time-consuming to perform and may not be readily available in decentralized laboratories, particularly in low-to-middle income countries. Molecular diagnostics can be a sensitive and accurate alternative to the traditional IHC, and the GeneXpert Breast Cancer Stratifier assay RUO (BC Strat), a single use cartridge-based assay performed on the broadly distributed GeneXpert® Instrument (GX) platform, streamlines a technically demanding RT-qPCR process to provide easy, robust, and reproducible ESR1, PGR, ERBB2, and MKi67 mRNA measurements from a 4 µm thick, formalin-fixed paraffin embedded (FFPE) breast tumor section in less than 2 hours.

METHODS: Analytical validation of the BC Strat assay included studies of Linearity/Dynamic Range, Analytical Sensitivity (Minimum Assay Input), Specificity (Potential Interfering Substances), Carryover Contaminations, and Kit and Specimen Slide Stabilities. Both in-vitro RNA transcript (IVT) and/or clinical breast cancer tissues were used as sample input materials. Assay results for each analyte were generated from cycle threshold (Ct) values, and final positive/negative test results for each target were also reported as delta Ct values, where dCt = Ct [CYFIP1 Reference] – Ct [Target], using dCt cutoffs previously derived from a clinical sample cohort.

RESULTS: The BC Strat assay demonstrated ≥3 log Linear Dynamic Range covering 5-7 logs sample input for all 4 Target dCts with R2≥0.95 independently. The assay currently requires minimal sample input equivalent to CYFIP1 Ct≤35 (Ct=33.5 ±1.5Ct SD) from 20 replicates of 5-level serial sample dilutions using two independent assay lot materials. It is acceptably robust against non-tumor tissues, DCIS, necrotic and/or hemorrhagic cells, lymphocytes, and genomic DNA contaminants. No carryover contamination from the same GeneXpert module was observed over 20 repeat tests during 9 consecutive days. Current real-time data supports assay stability at 5, 30, 37, 45 and 50°C for at least 3 months with minimal performance impact. Sectioned FFPE breast tumor tissues generated consistent dCt results when stored at 4°C and 30°C for up to 1 month before BC Strat assay testing.

CONCLUSIONS: The analytical validations of the BC Strat assay demonstrate an easy and robust mRNA detection with high sensitivity, specificity, reproducibility, and stability in order to aid medical pathologists and clinicians to more rapidly and objectively determine ESR1, PGR, ERBB2, and MKi67 mRNA status in breast cancer. Although stability studies out to 37 months are ongoing, current data suggest the assay is stable for at least 3 months over a wide range of temperatures. The GeneXpert Breast Cancer Stratifier assay potentially offers a rapid, standardized, and cost-effective solution to streamlining complex molecular diagnostics available for use in local pathology laboratories worldwide.

Citation Format: Chu VC, Wu N, Ho KE, Rizo A, Malek M, Weidler JM, Bates M, Wong W. Analytical validation for the RT-qPCR based multiplex mRNA measurements of ER, PgR, HER2, and Ki67 from FFPE tumor tissue using the GeneXpert breast cancer stratifier assay [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-03-11.

Search for Dark Matter and Supersymmetry with a Compressed Mass Spectrum in the Vector Boson Fusion Topology in Proton-Proton Collisions at sqrt[s]=8 TeV

A first search for pair production of dark matter candidates through vector boson fusion in proton-proton collisions at sqrt[s]=8  TeV is performed with the CMS detector. The vector boson fusion topology enhances missing transverse momentum, providing a way to probe supersymmetry, even in the case of a compressed mass spectrum. The data sample corresponds to an integrated luminosity of 18.5  fb^{-1}, recorded by the CMS experiment. The observed dijet mass spectrum is consistent with the standard model expectation. In an effective field theory, dark matter masses are explored as a function of contact interaction strength. The most stringent limit on bottom squark production with mass below 315 GeV is also reported, assuming a 5 GeV mass difference with respect to the lightest neutralino.

Measurements of the [Formula: see text] production cross section in lepton+jets final states in pp collisions at 8 [Formula: see text] and ratio of 8 to 7 [Formula: see text] cross sections

A measurement of the top quark pair production ([Formula: see text]) cross section in proton-proton collisions at the centre-of-mass energy of 8[Formula: see text] is presented using data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.6[Formula: see text]. This analysis is performed in the [Formula: see text] decay channels with one isolated, high transverse momentum electron or muon and at least four jets, at least one of which is required to be identified as originating from hadronization of a b quark. The calibration of the jet energy scale and the efficiency of b jet identification are determined from data. The measured [Formula: see text] cross section is [Formula: see text]. This measurement is compared with an analysis of 7[Formula: see text] data, corresponding to an integrated luminosity of 5.0[Formula: see text], to determine the ratio of 8[Formula: see text] to 7[Formula: see text] cross sections, which is found to be [Formula: see text]. The measurements are in agreement with QCD predictions up to next-to-next-to-leading order.

Measurement of Coherent π^{+} Production in Low Energy Neutrino-Carbon Scattering

We report the first measurement of the flux-averaged cross section for charged current coherent π^{+} production on carbon for neutrino energies less than 1.5 GeV, and with a restriction on the final state phase space volume in the T2K near detector, ND280. Comparisons are made with predictions from the Rein-Sehgal coherent production model and the model by Alvarez-Ruso et al., the latter representing the first implementation of an instance of the new class of microscopic coherent models in a neutrino interaction Monte Carlo event generator. We observe a clear event excess above background, disagreeing with the null results reported by K2K and SciBooNE in a similar neutrino energy region. The measured flux-averaged cross sections are below those predicted by both the Rein-Sehgal and Alvarez-Ruso et al.

Measurement of dijet azimuthal decorrelation in pp collisions at [Formula: see text]

A measurement of the decorrelation of azimuthal angles between the two jets with the largest transverse momenta is presented for seven regions of leading jet transverse momentum up to 2.2[Formula: see text]. The analysis is based on the proton-proton collision data collected with the CMS experiment at a centre-of-mass energy of 8[Formula: see text] corresponding to an integrated luminosity of 19.7[Formula: see text]. The dijet azimuthal decorrelation is caused by the radiation of additional jets and probes the dynamics of multijet production. The results are compared to fixed-order predictions of perturbative quantum chromodynamics (QCD), and to simulations using Monte Carlo event generators that include parton showers, hadronization, and multiparton interactions. Event generators with only two outgoing high transverse momentum partons fail to describe the measurement, even when supplemented with next-to-leading-order QCD corrections and parton showers. Much better agreement is achieved when at least three outgoing partons are complemented through either next-to-leading-order predictions or parton showers. This observation emphasizes the need to improve predictions for multijet production.

Development of parietal bone surrogates for parietal graft lift training

Currently the surgical training of parietal bone graft techniques is performed on patients or specimens. Commercially available bone models do not deliver realistic haptic feedback. Thus customized parietal skull surrogates were developed for surgical training purposes. Two human parietal bones were used as reference. Based on the measurement of insertion forces of drilling, milling and saw procedures suitable material compositions for molding cortical and cancellous calvarial layers were found. Artificial skull caps were manufactured and tested. Additionally microtomograpy images of human and artificial parietal bones were performed to analyze outer table and diploe thicknesses. Significant differences between human and artificial skulls were not detected with the mechanical procedures tested. Highly significant differences were found for the diploe thickness values. In conclusion, an artificial bone has been created, mimicking the properties of human parietal bone thus being suitable for tabula externa graft lift training.

Measurement of the differential cross section and charge asymmetry for inclusive [Formula: see text] production at [Formula: see text] TeV

The differential cross section and charge asymmetry for inclusive [Formula: see text] production at [Formula: see text] are measured as a function of muon pseudorapidity. The data sample corresponds to an integrated luminosity of 18.8[Formula: see text] recorded with the CMS detector at the LHC. These results provide important constraints on the parton distribution functions of the proton in the range of the Bjorken scaling variable x from [Formula: see text] to [Formula: see text].

Search for direct pair production of supersymmetric top quarks decaying to all-hadronic final states in pp collisions at [Formula: see text]

Results are reported from a search for the pair production of top squarks, the supersymmetric partners of top quarks, in final states with jets and missing transverse momentum. The data sample used in this search was collected by the CMS detector and corresponds to an integrated luminosity of 18.9[Formula: see text] of proton-proton collisions at a centre-of-mass energy of 8[Formula: see text] produced by the LHC. The search features novel background suppression and prediction methods, including a dedicated top quark pair reconstruction algorithm. The data are found to be in agreement with the predicted backgrounds. Exclusion limits are set in simplified supersymmetry models with the top squark decaying to jets and an undetected neutralino, either through a top quark or through a bottom quark and chargino. Models with the top squark decaying via a top quark are excluded for top squark masses up to 755[Formula: see text] in the case of neutralino masses below 200[Formula: see text]. For decays via a chargino, top squark masses up to 620[Formula: see text] are excluded, depending on the masses of the chargino and neutralino.