Comparing the TiOblast and Osseospeed surfaces. Histomorphometric and histological analysis in humans

The aim of the present study was to compare two implant surfaces, the TiOblast (Astra Tech) surface, manufactured by blasting the surface and already present in literature and the Osseospeed (Astra Tech) surface, manufactured by blasting and treating the surface with fluoride ions and recently launched onto the market with the modified surfaces of the latest generation. This study is part of a more extensive research project whose protocol required the insertion of 10 couples of implants; thus in the present discussion partial data are being taken into consideration, with an eye at collecting more data in the future, regarding both microscopy and histomorphometric histological analysis on 5 couples of implants. The purpose of the study is to investigate how the modified surfaces of the latest generation can guarantee a greater osseointegration both from a qualitative and quantitative level compared to the surfaces presently used and that they may represent the first example of "bioactivity", that is, an active interaction with the processes of new bone formation and tissue healing

Ka-band (32-GHz) performance of 70-meter antennas in the Deep Space Network

Two models are provided of the Deep Space Network (DSN) 70 m antenna performance at Ka-band (32 GHz) and, for comparison purposes, one at X-band (8.4 GHz). The baseline 70 m model represents expected X-band and Ka-band performance at the end of the currently ongoing 64 m to 70 m mechanical upgrade. The improved 70 m model represents two sets of Ka-band performance estimates (the X-band performance will not change) based on two separately developed improvement schemes: the first scheme, a mechanical approach, reduces tolerances of the panels and their settings, the reflector structure and subreflector, and the pointing and tracking system. The second, an electronic/mechanical approach, uses an array feed scheme to compensate fo lack of antenna stiffness, and improves panel settings using microwave holographic measuring techniques. Results are preliminary, due to remaining technical and cost uncertainties. However, there do not appear to be any serious difficulties in upgrading the baseline DSN 70 m antenna network to operate efficiently in an improved configuration at 32 GHz (Ka-band). This upgrade can be achieved by a conventional mechanical upgrade or by a mechanical/electronic combination. An electronically compensated array feed system is technically feasible, although it needs to be modeled and demonstrated. Similarly, the mechanical upgrade requires the development and demonstration of panel actuators, sensors, and an optical surveying system

The DICE calibration project: design, characterization, and first results

We describe the design, operation, and first results of a photometric calibration project, called DICE (Direct Illumination Calibration Experiment), aiming at achieving precise instrumental calibration of optical telescopes. The heart of DICE is an illumination device composed of 24 narrow-spectrum, high-intensity, light-emitting diodes (LED) chosen to cover the ultraviolet-to-near-infrared spectral range. It implements a point-like source placed at a finite distance from the telescope entrance pupil, yielding a flat field illumination that covers the entire field of view of the imager. The purpose of this system is to perform a lightweight routine monitoring of the imager passbands with a precision better than 5 per-mil on the relative passband normalisations and about 3{\AA} on the filter cutoff positions. The light source is calibrated on a spectrophotometric bench. As our fundamental metrology standard, we use a photodiode calibrated at NIST. The radiant intensity of each beam is mapped, and spectra are measured for each LED. All measurements are conducted at temperatures ranging from 0{\deg}C to 25{\deg}C in order to study the temperature dependence of the system. The photometric and spectroscopic measurements are combined into a model that predicts the spectral intensity of the source as a function of temperature. We find that the calibration beams are stable at the $10^{-4}$ level -- after taking the slight temperature dependence of the LED emission properties into account. We show that the spectral intensity of the source can be characterised with a precision of 3{\AA} in wavelength. In flux, we reach an accuracy of about 0.2-0.5% depending on how we understand the off-diagonal terms of the error budget affecting the calibration of the NIST photodiode. With a routine 60-mn calibration program, the apparatus is able to constrain the passbands at the targeted precision levels.Comment: 25 pages, 27 figures, accepted for publication in A&

A simplified sars-cov-2 pseudovirus neutralization assay

COVID-19 is an ongoing pandemic caused by the highly infectious coronavirus SARS-CoV-2 that is engaging worldwide scientific research to find a timely and effective eradication strategy. Great efforts have been put into anti-COVID-19 vaccine generation in an effort to protect the world population and block SARS-CoV-2 spread. To validate the protective efficacy of the vaccination campaign and effectively control the pandemic, it is necessary to quantify the induction of neutralizing antibodies by vaccination, as they have been established to be a correlate of protection. In this work, a SARS-CoV-2 pseudovirus neutralization assay, based on a replication-incompetent lentivirus expressing an adapted form of CoV-2 S protein and an ACE2/TMPRSS2 stably expressing cell line, has been minimized in terms of protocol steps without loss of accuracy. The goal of the present simplified neutralization system is to improve SARS-CoV-2 vaccination campaign by means of an easy and accessible approach to be performed in any medical laboratory, maintaining the sensitivity and quantitative reliability of classical serum neutralization assays. Further, this assay can be easily adapted to different coronavirus variants by simply modifying the pseudotyping vector

Angiogenesis modifications related with cetuximab plus irinotecan as anticancer treatment in advanced colorectal cancer patients.

Introduction: Angiogenesis has been correlated with increased invasion and metastases in a variety of human neoplasms. Inadequate inhibition of the growth of tumor microvessels by anticancer agents may result in treatment failure, rated clinically as progressive or stable disease. We designed this trial to investigate the modification of the vascular endothelial growth factor (VEGF) and interferon-c (IFN-c) in advanced colorectal cancer patients during treatment with a weekly combination of cetuximab plus irinotecan. Materials and methods: Forty-five metastatic colorectal cancer patients were prospectively evaluated for circulating levels of VEGF and IFN-c during the treatment with cetuximab (initial dose of 400 mg/m2 , followed by weekly infusions of 250 mg/m2 ) plus weekly irinotecan (90 mg/m2 ). The circulating levels of the cytokines were assessed at the following time points: just before and at 1, 21, 50 and 92 days after the start of cetuximab plus irinotecan treatment. Results: Basal serum VEGF median levels were significantly decreased just at the first day (after the first treatment infusion (P = 0.016). The VEGF persisted at the following time points reaching the highest statistical significance 92 days after the first infusion (P < 0.0001). On the contrary, IFN-c values showed a statistical significant increase one day after the first infusion (P < 0.0001). This effect persisted 21 days after the treatment start (P = 0.001), but was no more evident at the following time points. Moreover, a linear regression model with variance analysis showed a significant negative correlation between VEGF and IFN-c values 1, 21 and 50 days after the treatment beginning (P = 0.002, 0.001 and 0.047, respectively). Conclusions: This study suggests that a cetuximab may induce a modulation of VEGF circulating levels. The reduction of VEGF serum levels is a sudden and long lasting phenomenon. Moreover, in our study we identified a IFN-c increase, even if the specific role of this behavior remains to be investigated