Enhanced Nonlinear Response by Manipulating the Dirac Point at the (111) LaTiO_{3}/SrTiO_{3} Interface

Tunable spin-orbit interaction (SOI) is an important feature for future spin-based devices. In the presence of a magnetic field, SOI induces an asymmetry in the energy bands, which can produce nonlinear transport effects (V∼I^{2}). Here, we focus on such effects to study the role of SOI in the (111) LaTiO_{3}/SrTiO_{3} interface. This system is a convenient platform for understanding the role of SOI since it exhibits a single-band Hall response through the entire gate-voltage range studied. We report a pronounced rise in the nonlinear longitudinal resistance at a critical in-plane field H_{cr}. This rise disappears when a small out-of-plane field component is present. We explain these results by considering the location of the Dirac point formed at the crossing of the spin-split energy bands. An in-plane magnetic field pushes this point outside of the Fermi contour, and consequently changes the symmetry of the Fermi contours and intensifies the nonlinear transport. An out-of-plane magnetic field opens a gap at the Dirac point, thereby significantly diminishing the nonlinear effects. We propose that magnetoresistance effects previously reported in interfaces with SOI could be comprehended within our suggested scenario.

Two-component nematic superconductivity in 4Hb-TaS2

Most superconductors have an isotropic, single component order parameter and are well described by the standard (BCS) theory for superconductivity. Unconventional, multiple-component superconductors are exceptionally rare and are much less understood. Here, we combine scanning tunneling microscopy and angle-resolved macroscopic transport for studying the candidate chiral superconductor, 4Hb-TaS2. We reveal quasi-periodic one-dimensional modulations in the tunneling conductance accompanied by two-fold symmetric superconducting critical field. The strong modulation of the in-plane critical field, Hc2, points to a nematic, unconventional order parameter. However, the imaged vortex core is isotropic at low temperatures. We suggest a model that reconciles this apparent discrepancy and takes into account previously observed spontaneous time-reversal symmetry breaking at low temperatures. The model describes a competition between a dominating chiral superconducting order parameter and a nematic one. The latter emerges close to the normal phase. Our results strongly support the existence of two-component superconductivity in 4Hb-TaS2 and can provide valuable insights into other systems with coexistent charge order and superconductivity.

RBE Model Based Proton Planning of Stereotactic Body Radiotherapy for Spine Metastasis: A Dosimetric Analysis

PURPOSE/OBJECTIVE(S)

Study of proton stereotactic body radiotherapy (SBRT) for spine metastasis is limited, largely due to theorized increased risk of spinal cord injury with higher end of range RBE. Though the 1.1 RBE constant for proton beam is clinically used, data indicate that proton RBE is variable and dependent on technical-, tissue-, and patient-factors. To better understand safety of proton SBRT for spine metastasis, we performed a dosimetric analysis comparing plans delivered by photon robotic technique versus intensity modulated proton therapy (IMPT) and accounting for RBE weighted dose.

MATERIALS/METHODS

A total of 9 patients with spine metastasis (3 cervical, 3 thoracic, 3 lumbar) previously treated with a frameless robotic radiosurgery system (Sunnyvale, CA) were identified. Each level contained a case with paraspinal extension, a reirradiation case, and a case with epidural extension (Bilsky grade ≥1c) as such cases in current practice often require planning target volume (PTV) under-coverage in order to meet organ at risk (OAR) dose constraints. Given these challenges, selected cases were clinically treated with 30 Gy in 5 fractions despite an institutional preference of further dose escalation. Comparative IMPT plans were generated using 30 GyE in 5 fractions and 1.1 RBE constant. IMPT plans were then made using 1.1 RBE and 45 GyE in 5 fractions: a prescription dose associated with a 2-yr local control rate of 95% on prior tumor control probability modelling. A treatment planning system was used to separately generate and optimize RBE weighted plans based on Carabe-, McNamara-, or Wedenberg models for prescription doses of 30 GyE and 45 GyE. IMPT plans used robust optimization parameters of ± 3.5% range and 2-mm setup uncertainties. PTV coverage and OAR sparing were compared using Wilcoxon signed-rank tests.

RESULTS

PTV coverage (PTV volume receiving prescription dose) was significantly improved with IMPT at 30 GyE / 1.1 RBE (median PTV V30: 93%) compared to CK at 30 Gy (median: 88.5%, p = .02). PTV coverage was similar when comparing CK at 30 Gy with IMPT at 45 GyE / 1.1 RBE (median PTV V45: 90%, p = .23). When comparing maximum spinal cord dose (cord Dmax), there was improved OAR sparing with IMPT at 30 GyE / 1.1 RBE (median: 17.6 GyE, p = .04) and IMPT at 45 GyE / 1.1 RBE (median: 16.1 GyE, p = .04) when respectively compared to CK at 30 Gy (median: 18 Gy). No difference was seen in cord Dmax when comparing CK at 30 Gy to RBE weighted plans at 30 GyE using Carabe- (median: 17.3 GyE, p = .22), McNamara- (median: 17.4 GyE, p = .22), or Wedenberg (median: 17.0 GyE, p = .08) model. Median cord Dmax values for RBE weighted plans at 45 GyE were numerically equivalent. The average increase in variable RBE plans' maximum dose compared to fixed RBE plans was 105.3% +/- 3.5%.

CONCLUSION

We report the first dosimetric analysis of proton SBRT for spine metastasis using variable RBE dose models. IMPT may provide improved target coverage and better sparing of adjacent OARs compared to CK though fixed RBE computation may underestimate maximum dose to adjacent OARs.

HPV Infection Causes Dependence on Alternative DNA Damage Response Pathways Providing Cancer Specific Targets for Radiosensitization

PURPOSE/OBJECTIVE(S)

Cancer-specific radiosensitization is an attractive approach to improving the efficacy of radiotherapy. However, drugs targeting ubiquitous DNA damage response pathways are not cancer specific and can increase radiation related side effects. Thus, there is an unmet need for tumor specific molecular targets. This approach requires an identification of DNA damage signaling pathways that are unique to cancer cells. We hypothesized that by expressing its genome in the host cells HPV infection can rewire DNA damage signaling making HPV-positive tumor cells dependent on alternative pathways to survive radiation, which can be exploited for radiosensitization of HPV-induced cancers.

MATERIALS/METHODS

We have performed a CRISPR/Cas9 screen in HPV-positive SiHa cells that either express HPV16 proteins E6 and E7 or contain a selective knock-out of E6 or E7. We used next-generation sequencing to determine the abundance of gRNA in cells that were mock-treated or irradiated. We identified genes that were required for survival of radiation specifically in the context of E6 or E7 expression. Results of the screen were validated by generating knock-outs of the discovered genes using CRISPR/Cas9. By applying an array of molecular tools to analyze cell survival, cell cycle progression and mitotic progression we assessed the role of these genes in radiation response in HPV-positive cancer cells.

RESULTS

We have identified genes that are required for survival of radiation-induced DNA damage in the context of either E6 or E7 expression. We demonstrate that targeting these genes results in hypersensitization of cervical cancer cells to radiation specifically in the presence of E6 or E7. We show that the gene product required for survival in E6-expressing cells is critical for mitotic progression after radiation exposure serving as a member of a protein complex stabilizing the attachment of mitotic spindle to centromeres.

CONCLUSION

We have uncovered specific genes that are critical for DNA damage response and cell survival after radiation exposure in HPV-positive cells. Our findings suggest that expression of the HPV proteins E6 and E7 rewires DNA damage signaling causing dependence on alternative response pathways. We propose that these pathways can be targeted for a tumor-specific radiosensitization of HPV-induced cancers.

Inelastic Scattering of a Photon by a Quantum Phase Slip

Spontaneous decay of a single photon is a notoriously inefficient process in nature irrespective of the frequency range. We report that a quantum phase-slip fluctuation in high-impedance superconducting waveguides can split a single incident microwave photon into a large number of lower-energy photons with a near unit probability. The underlying inelastic photon-photon interaction has no analogs in nonlinear optics. Instead, the measured decay rates are explained without adjustable parameters in the framework of a new model of a quantum impurity in a Luttinger liquid. Our result connects circuit quantum electrodynamics to critical phenomena in two-dimensional boundary quantum field theories, important in the physics of strongly correlated systems. The photon lifetime data represent a rare example of verified and useful quantum many-body simulation.

Increased incidence of Susac syndrome: a case series study

BACKGROUND

Susac syndrome (SuS) is a rare condition characterized by a clinical triad of sensorineural hearing loss, branch artery occlusion and encephalopathy. This study reports an increased incidence of SuS in Israel. We describe the clinical characteristics of these patients, diagnostic procedures and the use and subsequent outcomes of newly published treatment guidelines.

METHODS

This is a single center retrospective study. Patients who were diagnosed with SuS between July 2017 and August 2018 were enrolled in this study.

RESULTS

Seven patients were diagnosed with SuS according to the diagnostic criteria in a time period of 13 months. The annual incidence was recently evaluated in Austria to be 0.024/100000, therefore, our case series represent at least a 5.4- fold increase in the annual incidence of SuS expected in Israel and a 7-fold increase in the annual incidence expected in our medical center. Mean time from the onset of the symptoms to diagnosis was three weeks and follow-up time was twenty four months. Recent exposure to cytomegalovirus was serologically evident in three patients and one patient had high titer of anti-streptolysin antibody. All patients underwent brain MRI, fluorescein angiography and audiometry. All patients were treated according to the newly recommended guidelines. All patients achieved clinical and radiological stability.

CONCLUSIONS

We report of an increased incidence of SuS in Israel. Infectious serological findings may imply a post infectious mechanism. The use of the recommended diagnostic procedures reduced the time to diagnosis. Newly published treatment guidelines led to favorable clinical outcomes.

Abstract 580: Detailed analysis of immune responses induced against patient-specific neoantigens using the ex-vivo induction protocol, NEO-STIM™

Background: Neoantigens are tumor-specific antigens that have been shown to be critical in the anti-tumor immune response. These antigens are not subject to central immune tolerance and are therefore potentially more immunogenic than tumor-associated antigens. The goal of our studies is to assess the immunogenic potential of high-quality neoantigen targets, as defined through our bioinformatic engine RECON®, as well as perform detailed characterization of the induced T cell responses towards these neoantigen targets.

Methods: Patient-specific neoantigens were predicted using our bioinformatic engine RECON. The predicted high quality neoantigens were utilized in our proprietary ex-vivo stimulation protocol NEO-STIM to assess immunogenicity. NEO-STIM is used to prime, activate and expand memory and de novo T cell responses from both the CD4+ as well as the CD8+ compartment. In-depth analysis was performed to characterize the specificity, functionality (cytokine production and cytolytic capacity) and diversity of the induced T cell responses.

Results: Here we present the successful induction of memory and de novo CD8+ T cell responses in PBMCs isolated by leukapheresis from three patients using NEO-STIM (2 with melanoma & 1 with NSCLC). We then deeply characterize the induced CD8+ T cell responses of one of the melanoma patients and show that these responses are functional, specific and have cytolytic capacity. Furthermore, we use paired single cell RNA and TCR sequencing to assess the diversity and gene expression profile of these responses.

Conclusions: NEO-STIM is a novel platform to understand the immunogenic potential of high-quality neoantigen-targets in detail. Moreover, this platform can be utilized to generate T cell products for adoptive cell therapy for patients with a variety of solid and liquid tumors.

Citation Format: Divya Lenkala, Jessica Kohler, Brian McCarthy, Michael Nelson, Rachel DeBarge, Yvonne Ware, Yuting Huang, Janani Sridar, Yusuf Nasrullah, Dewi Hartjano, Asaf Poran, Sejuti Sengupta, Joost H. van den Berg, Matt Goldstein, Richard B. Gaynor, Marit M. van Buuren. Detailed analysis of immune responses induced against patient-specific neoantigens using the ex-vivo induction protocol, NEO-STIM™ [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 580.

Abstract P6-18-30: Phase Ib/II study of capecitabine 7/7 schedule with neratinib in patients with HER2-positive metastatic breast cancer (MBC)

Background: Neratinib (N) is a potent irreversible inhibitor of HER1, HER2, and HER4 and has been shown to have antitumor activity in patients (pts) with human epidermal growth factor receptor 2 (HER2) - positive breast cancer. A previous study of combination of neratinib with capecitabine (X) was associated with > G 3 diarrhea in > 20% of patients. Currently, the NALA study is evaluating this combination of N with X at standard schedule against control. X at 7 day on and 7 day off schedule (7/7) has been shown to be well-tolerated with less ≥G3 toxicities. We are conducting a phase Ib/II study of N with X (7/7) in pts with pretreated HER2+ MBC (NCT03377387). Methods: Eligible pts had HER2+ MBC, normal left ventricular ejection fraction (LVEF ≥ 50%); pts can have any and up to 4 prior chemotherapy-based treatments in phase Ib and II portions, respectively. Primary endpoints are to define maximum tolerated dose and efficacy in phase I and phase II portions, respectively. Secondary endpoints include safety and tolerability; exploratory endpoint is to quantify cell-free DNA to correlate with response for phase II portion. There were 4 cohorts for phase Ib with dose level 1 with starting dose of X at 1500 mg BID at 7/7 schedule with N at 240 mg daily. Results: As of July 1, 2018 8 pts have been enrolled in 2 cohorts. The median age is 63y (range: 57-79), and median ECOG is 0 (range: 0-1). 4 patients were treated at dose level 1 and 2 of 4 patients experienced dose-limiting toxicity with G3 diarrhea during cycle 1. Other significant toxicities included G3 hand foot syndrome (n=1), G3 fatigue (n=1) and G3 nausea (n=1). Three pts have now been treated at dose level -1 (X at 1000 mg twice daily 7/7 and N at 240 mg daily) and no ≥ G3 toxicities has been noted. Once MTD is reached, the phase II portion will occur to assess the efficacy and to further establish the safety and tolerability of capecitabine and neratinib at the MTD. Conclusions: The phase Ib/II study combining neratinib and capecitabine 7/7 is ongoing and updated result will be presented.

Citation Format: Wang R, Singh J, Sterlin V, Goldstein M, Lake D, Wong S, Baselga J, Norton L, Dang C. Phase Ib/II study of capecitabine 7/7 schedule with neratinib in patients with HER2-positive metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-30.

Axial Length, Refractive Error, and Keratometry in Patients with Branch Retinal Vein Occlusion

Purpose

To evaluate ocular parameters that may predispose to the development of branch retinal vein occlusion (BRVO).

METHODS

This prospective study included patients with unilateral BRVO evaluated in the authors' clinic. The mean period from the acute phase was 2.29 ±1.57 years (range 1–6 years). All patients underwent a complete ophthalmologic examination including subjective refraction, axial length measurements, and keratometry readings. The fellow eye served as a control in each patient. The variables of interest were compared between the affected eye and the fellow eye using the parametric t-test and the nonparametric Wilcoxon test.

Results

Twenty-four consecutive patients (14 women, 10 men, mean age 62.4 years) were included in the study. The mean axial length in the affected eye was significantly shorter compared to the mean fellow eye length. No difference was found between the two eyes in mean subjective refraction or mean keratometry readings.

CONCLUSIONS

The authors found that eyes with BRVO have a shorter axial length compared to the fellow eye in the same patient.

Evaluating the peptide structure prediction capabilities of a purely ab-initio method

DEEPSAM is a relatively new global optimization algorithm aimed to predict the structure of bio-molecules from sequence, without any additional preliminary assumption. It is an evolutionary algorithm whose mutation operators are built by hybridizing the diffusion equation method, molecular dynamics simulated annealing, and a quasi-Newton local minimization method. The goal of this study was to evaluate the structure prediction capabilities of DEEPSAM by running it upon NMR structures of linear peptides (10-20 residues). The results indicate that DEEPSAM successfully predicted the conformations of these peptides, using modest computing resources.

The impact of CT head scans on ED management and length of stay in bizarre behavior patients

METHODS

A 5-year retrospective chart review was conducted at 3 EDs. Inclusion criteria were patients ≥18years old triaged as "mental health - bizarre behavior" (deviation from normal cognitive behaviour with no obvious cause) with a CT head scan ordered in the ED. Exclusion criteria were focal neurologic deficits on exam, alternative medical etiology (i.e. delirium, trauma) and/or pre-existing CNS disease. Clinical, demographic and administrative data were extracted with 10% of charts independently reviewed by an Emergency Physician for inter-rater reliability.

RESULTS

266 cases met study criteria. Population demographics: 49% percent female, average age 51years old, 28% homeless, 58% arrived by police or ambulance. CT head results: 1 (0.4%) case with possible acute findings, 105 (39%) with incidental findings (i.e. cerebral atrophy) that did not impact clinical management. Average time to physician assessment was 1:48 (hour:min) (sd 1:11), time to CT completion was 5:05 (sd 7:28) and an average delay of 3:17 awaiting results. Subgroup analysis revealed a net increase in ED length of stay (ED LOS) of 5:02 from obtaining neuroimaging. 85% of patients were referred to a consultant, 92% were to psychiatry.

CONCLUSIONS

CT head results prolonged ED LOS, delayed patient disposition and did not change the patient's clinical management. A prospective trial for ordering CT head scans in these patients is warranted.

Comparative study of magnetic resonance defaecography and evacuation proctography in the evaluation of obstructed defaecation

AIM

Obstructed defaecation syndrome is a common condition of multifactorial aetiology and requires specialized evaluation. Accurate and reproducible pelvic floor imaging is imperative for multidisciplinary decision-making. Evacuation proctography (EP) and magnetic resonance defaecography (MRD) are the main imaging modalities used to assess dynamic pelvic floor function. The aim of this prospective study was to compare the findings and acceptability of MRD and EP in the same cohort of patients.

METHOD

This was a prospective comparative study of MRD vs EP in 55 patients with obstructed defaecation syndrome in a single National Health Service Foundation Trust.

RESULTS

Fifty-five patients were recruited and underwent both EP and MRD. Detection rates for rectocoele were similar (82% vs 73%, P = 0.227), but EP revealed a significantly higher number of trapping rectocoeles compared to MRD (75% vs 31%, P < 0.001). EP detected more rectal intussusceptions than MRD (56% vs 35%, P = 0.023). MRD appeared to underestimate the size of the identified rectocoele, although it detected a significant number of anatomical abnormalities in the middle and anterior pelvic compartment not seen on EP (1.8% enterocoele, 9% peritoneocoele and 20% cystocoele). Patients achieved higher rates of expulsion of rectal contrast during EP compared to MRD, but this difference was not significant (76% vs 64% in MRD, P = 0.092). Of the two studies, patients preferred MRD.

CONCLUSIONS

MRD provides a global assessment of pelvic floor function and anatomical abnormality. MRD is better tolerated by patients but it is not as sensitive as EP in detecting trapping rectocoeles and intussusceptions.

Pricing the urban cooling benefits of solar panel deployment in Sydney, Australia

Cities import energy, which in combination with their typically high solar absorption and low moisture availability generates the urban heat island effect (UHI). The UHI, combined with human-induced warming, makes our densely populated cities particularly vulnerable to climate change. We examine the utility of solar photovoltaic (PV) system deployment on urban rooftops to reduce the UHI, and we price one potential value of this impact. The installation of PV systems over Sydney, Australia reduces summer maximum temperatures by up to 1 °C because the need to import energy is offset by local generation. This offset has a direct environmental benefit, cooling local maximum temperatures, but also a direct economic value in the energy generated. The indirect benefit associated with the temperature changes is between net AUD$230,000 and $3,380,000 depending on the intensity of PV systems deployment. Therefore, even very large PV installations will not offset global warming, but could generate enough energy to negate the need to import energy, and thereby reduce air temperatures. The energy produced, and the benefits of cooling beyond local PV installation sites, would reduce the vulnerability of urban populations and infrastructure to temperature extremes.

Aflibercept as a Second Line Therapy for Neovascular Age Related Macular Degeneration in Israel (ASLI) study

PurposeThe purpose of this study is to evaluate an early switch to aflibecept in eyes with neovascular age-related macular degeneration (nvAMD) showing partial or lack of response for initial therapy with bevacizumab.MethodsThe Aflibercept as a Second Line Therapy for Neovascular Age Related Macular Degeneration in Israel (ASLI) was a prospective, multicenter, single-arm clinical trial. Eyes with nvAMD having incomplete response to 3-9 prior bevacizumab injections were recruited. Three monthly intravitreal aflibercept (2 mg) injections were administered, followed by two bi-monthly injections and a final examination at week 28. An optional injection was allowed at week 20.ResultsForty-seven eyes of 46 patients (mean±SD age 76±8 years) were recruited. The mean number of prior bevacizumab injections was 5.5±2.9. The mean visual acuity improved from 60.3±10 ETDRS letters at baseline to 63.1±15 letters at week 28 (P=0.02, paired t-test). The central subfield thickness (CST) reduced from 409±127 micron at baseline to 330±110 microns at week 4 (P=0.0002; paired t-test), and 277±70 microns at week 28 (P=0.00002; paired t-test). Twenty-two eyes had three to five prior bevacizumab injections (mean 5.1±0.7), and 25 eyes had six to nine prior injections (7.32±1.2). Both groups had reduced CST from baseline to week 28 (P=0.0004 and P=0.0007; paired t-test, respectively). Thirty-five (75%) eyes required the optional additional aflibercept injection at week 20.ConclusionsThe ASLI study demonstrated improved BCVA and reduced CST following an early switch to aflibercept therapy in eyes with prior incomplete response to initial therapy with three to nine bevacizumab injections.

The FIELDS Instrument Suite for Solar Probe Plus: Measuring the Coronal Plasma and Magnetic Field, Plasma Waves and Turbulence, and Radio Signatures of Solar Transients

NASA's Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument concept of operations and planned data products.

History matching of a complex epidemiological model of human immunodeficiency virus transmission by using variance emulation

Complex stochastic models are commonplace in epidemiology, but their utility depends on their calibration to empirical data. History matching is a (pre)calibration method that has been applied successfully to complex deterministic models. In this work, we adapt history matching to stochastic models, by emulating the variance in the model outputs, and therefore accounting for its dependence on the model's input values. The method proposed is applied to a real complex epidemiological model of human immunodeficiency virus in Uganda with 22 inputs and 18 outputs, and is found to increase the efficiency of history matching, requiring 70% of the time and 43% fewer simulator evaluations compared with a previous variant of the method. The insight gained into the structure of the human immunodeficiency virus model, and the constraints placed on it, are then discussed.

Mercury Strain-Gauge Plethysmography Venous Mode: Non-Invasive Technique of Choice in Vascular Pathology

Mercury strain-gauge plethysmography venous mode is a non-invasive technique for exploration of the haemodynamics of the extremities. The plethysmographic parameters used are: (1) the venous inflow (in ml/100 ml/min); (2) the venous outflow (in ml/100 ml/min); (3) the venous capacity in ml/100ml; (4) the venous distensibility index in ml/100 ml/ mmHg; and (5) the venous pressure measured by ‘hysteresis curve’. This method permits us to analyse the venous haemodynamics of both extremities simultaneously (the normal limb serving as the control), to obtain a precise diagnosis and to appreciate the efficacy of treatment at follow-up.

The aetiology of the swollen limb can be precisely identified in 95% of the studied cases: oedema in superficial venous insufficiency, oedema in the deep venous insufficiency, oedema of inflammatory origin, oedema in the arterial insufficiency, oedema of cardiac origin, lymphoedema.

During the last 3 years, we have followed up 580 patients with this method.

Surface characterization and in vivo evaluation of laser sintered and machined implants followed by resorbable-blasting media process: A study in sheep

Background

This study aimed to compare the histomorphometric and histological bone response to laser-sintered implants followed by resorbable-blasting media (RBM) process relative to standard machined/RBM surface treated implants.

Material and Methods

Six male sheep (n=6) received 2 Ti-6Al-4V implants (1 per surface) in each side of the mandible for 6 weeks in vivo. The histomorphometric parameters bone-implant contact (BIC) and bone area fraction occupancy (BAFO) were evaluated.

Results

Optical interferometry revealed higher Sa and Sq values for the laser-sintered/RBM surface in relation to standard/RBM implants. No significant differences in BIC were observed between the two groups (p>0.2), but significantly higher BAFO was observed for standard/RBM implants (p<0.01).

Conclusions

The present study demonstrated that both surfaces were biocompatible and osseoconductive, and the combination of laser sintering and RBM has no advantage over the standard machined implants with subsequent RBM.

Key words:Dental implants, osseointegration, resorbable- blasting media, sheep, in vivo.

Tauopathy PET and amyloid PET in the diagnosis of chronic traumatic encephalopathies: studies of a retired NFL player and of a man with FTD and a severe head injury

Single, severe traumatic brain injury (TBI) which elevates CNS amyloid, increases the risk of Alzheimer's disease (AD); while repetitive concussive and subconcussive events as observed in athletes and military personnel, may increase the risk of chronic traumatic encephalopathy (CTE). We describe two clinical cases, one with a history of multiple concussions during a career in the National Football League (NFL) and the second with frontotemporal dementia and a single, severe TBI. Both patients presented with cognitive decline and underwent [(18)F]-Florbetapir positron emission tomography (PET) imaging for amyloid plaques; the retired NFL player also underwent [(18)F]-T807 PET imaging, a new ligand binding to tau, the main constituent of neurofibrillary tangles (NFT). Case 1, the former NFL player, was 71 years old when he presented with memory impairment and a clinical profile highly similar to AD. [(18)F]-Florbetapir PET imaging was negative, essentially excluding AD as a diagnosis. CTE was suspected clinically, and [(18)F]-T807 PET imaging revealed striatal and nigral [(18)F]-T807 retention consistent with the presence of tauopathy. Case 2 was a 56-year-old man with personality changes and cognitive decline who had sustained a fall complicated by a subdural hematoma. At 1 year post injury, [(18)F]-Florbetapir PET imaging was negative for an AD pattern of amyloid accumulation in this subject. Focal [(18)F]-Florbetapir retention was noted at the site of impact. In case 1, amyloid imaging provided improved diagnostic accuracy where standard clinical and laboratory criteria were inadequate. In that same case, tau imaging with [(18)F]-T807 revealed a subcortical tauopathy that we interpret as a novel form of CTE with a distribution of tauopathy that mimics, to some extent, that of progressive supranuclear palsy (PSP), despite a clinical presentation of amnesia without any movement disorder complaints or signs. A key distinguishing feature is that our patient presented with hippocampal involvement, which is more frequently seen in CTE than in PSP. In case 2, focal [(18)F]-Florbetapir retention at the site of injury in an otherwise negative scan suggests focal amyloid aggregation. In each of these complex cases, a combination of [(18)F]-fluorodeoxyglucose, [(18)F]-Florbetapir and/or [(18)F]-T807 PET molecular imaging improved the accuracy of diagnosis and prevented inappropriate interventions.

Pharmacological approach to diabetic macular edema

Diabetic macular edema (DME) is a highly prevalent cause of vision loss and has a remarkable impact on public health, and on the quality of life of diabetic patients. Even though laser photocoagulation has been the standard of care for decades, a substantial group of patients are unresponsive and fail to improve after laser treatment. Recently, new pharmacological approaches based on the use of intravitreal drugs, such as corticosteroids and anti-vascular endothelial growth factor, have revolutionized the treatment of DME. The use of intravitreal drugs is supported by the improvement in visual acuity reported by several clinical trials and can limit the potentially destructive effects of the laser treatment. Encouraging results also emerged from studies evaluating the use of a combination therapy, or the association of intravitreal drugs and laser treatment. This review aims at providing a brief synopsis of the main investigations regarding the current pharmacological approach to DME.

Proposed Rabi-Kondo correlated state in a laser-driven semiconductor quantum dot

Spin exchange between a single-electron charged quantum dot and itinerant electrons leads to an emergence of Kondo correlations. When the quantum dot is driven resonantly by weak laser light, the resulting emission spectrum allows for a direct probe of these correlations. In the opposite limit of vanishing exchange interaction and strong laser drive, the quantum dot exhibits coherent oscillations between the single-spin and optically excited states. Here, we show that the interplay between strong exchange and nonperturbative laser coupling leads to the formation of a new nonequilibrium quantum-correlated state, characterized by the emergence of a laser-induced secondary spin screening cloud, and examine the implications for the emission spectrum.