BackgroundThe primary objective of Tissue engineering is a regeneration or replacement of tissues or organs damaged by disease, injury, or congenital anomalies. At present, Tissue engineering repairs damaged tissues and organs with artificial supporting structures called scaffolds. These are used for attachment and subsequent growth of appropriate cells. During the cell growth gradual biodegradation of the scaffold occurs and the final product is a new tissue with the desired shape and properties.In recent years, research workplaces are focused on developing scaffold by bio-fabrication techniques to achieve fast, precise and cheap automatic manufacturing of these structures. Most promising techniques seem to be Rapid prototyping due to its high level of precision and controlling. However, this technique is still to solve various issues before it is easily used for scaffold fabrication.In this article we tested printing of clinically applicable scaffolds with use of commercially available devices and materials. Research presented in this article is in general focused on “scaffolding” on a field of bone tissue replacement.ResultsCommercially available 3D printer and Polylactic acid were used to create originally designed and possibly suitable scaffold structures for bone tissue engineering. We tested printing of scaffolds with different geometrical structures. Based on the osteosarcoma cells proliferation experiment and mechanical testing of designed scaffold samples, it will be stated that it is likely not necessary to keep the recommended porosity of the scaffold for bone tissue replacement at about 90%, and it will also be clarified why this fact eliminates mechanical properties issue. Moreover, it is demonstrated that the size of an individual pore could be double the size of the recommended range between 0.2–0.35 mm without affecting the cell proliferation.ConclusionRapid prototyping technique based on Fused deposition modelling was used for the fabrication of designed scaffold structures. All the experiments were performed in order to show how to possibly solve certain limitations and issues that are currently reported by research workplaces on the field of scaffold bio-fabrication. These results should provide new valuable knowledge for further research.

Physics beyond the Standard Model predicts the possible existence of new particles that can be searched at the low energy frontier in the sub-eV range. The OSQAR photon regeneration experiment looks for "Light Shining through a Wall" from the quantum oscillation of optical photons into "Weakly Interacting Sub-eV Particles", such as axion or Axion-Like Particles (ALPs), in a 9 T transverse magnetic field over the unprecedented length of 2 × 14.3 m. In 2014, this experiment has been run with an outstanding sensitivity, using an 18.5 W continuous wave laser emitting in the green at the single wavelength of 532 nm. No regenerated photons have been detected after the wall, pushing the limits for the existence of axions and ALPs down to an unprecedented level for such a type of laboratory experiment. The di-photon couplings of possible pseudoscalar and scalar ALPs can be constrained in the nearly massless limit to be less than 3.5·10 −8 GeV −1 and 3.2·10 −8 GeV −1 , respectively, at 95% Confidence Level.

2 3 4 5 6 7 8 9 10 11 12 and experimental 13, , , 14 15 16 studies shed light on possible new physics beyond the standard model of particle physics, which can be probed with sub-eV energy experiments. They were triggered by the observation of the PVLAS collaboration 17 , newly disclaimed 18,19 , of a rotation of polarization for light propagating in the vacuum permeated by a transverse magnetic field. The OSQAR project 20 proposed to investigate such possibilities by reusing superconducting dipole prototypes and related infrastructure developed at CERN for the Large Hadron Collider (LHC). Combined with innovative optical techniques, unique opportunities in the emerging field of laser-based particle physics are being taken. Here we report first results from the OSQAR photon regeneration experiment. When submitted to a transverse magnetic field, properly polarized photons can couple to weakly interacting scalar or pseudo-scalar particles like axions undergoing quantum oscillations 21 in a similar way to neutrinos. If an optical barrier is introduced in the light path, only photons converted into scalars or pseudoscalars will not be absorbed and can be regenerated on the other side of the barrier, allowing their detection as "a shining light through a wall" 22 . For this, a LHC superconducting dipole providing a field of up to 9.5 T over 14.3 m was equipped with an optical barrier at centre. As a new way to amplify the photon-axion conversions, the magnet aperture was filled with nitrogen gas at a specific pressure. At one magnet end an 18 W Ar+ laser was installed and aligned with a CCD detector sitting on the opposite end. As a result, no regenerated photons were detected. New bounds for mass and coupling constant for purely laboratory experiments aiming to detect any hypothetical scalars and pseudo-scalars which can couple to photons were obtained at 95% confidence level.The axion is a neutral pseudo-scalar particle predicted independently by S. Weinberg 23 and F. Wilczek 24 from the Peccei and Quinn 25 symmetry breaking. It remains the most plausible solution to the strong-CP problem 26 , i.e. the answer to the following question: Why the CP symmetry (Charge and Parity conservation), in view of the negative measurement results of the neutron electric dipolar moment 27 , seems not to be broken by the strong interaction? Recently, it has also been emphasized that the axion constitutes a fundamental underlying feature of the string theory in which a great number of axions or Axion-Like Particles (ALPs) is naturally present 26 . In addition, the interest in axion search lies beyond particle physics since such hypothetical light spin-zero particles are considered as one of the most serious darkmatter candidates 28 , and the only non-supersymmetric one. Within this scope and in agreement with previous measurement results excluding heavy axions 29 , the allowed range for the axion mass is nominally 10 -6 < m A < 10 -2 eV. From the experimental point of view, the hunt for light axions can be classified in two compleme...

Recent theoretical and experimental studies highlight the possibility of new fundamental particle physics beyond the Standard Model that can be probed by subeV energy experiments. The OSQAR photon regeneration experiment looks for "Light Shining through a Wall" from the quantum oscillation of optical photons into "Weakly Interacting Sub-eV Particles", like axion or axion-like particles (ALPs), in a 9 T transverse magnetic field over the unprecedented length of 2 × 14.3 m. No excess of events has been detected over the background. The di-photon couplings of possible new light scalar and pseudo-scalar particles can be constrained in the massless limit to be less than 8.0×10 −8 GeV −1 . These results are very close to the most stringent laboratory constraints obtained for the coupling of ALPs to two photons. Plans for further improving the sensitivity of the OSQAR experiment are presented.

We propose a miniaturised light stage for measuring the bidirectional reflectance distribution function (BRDF) and the bidirectional texture function (BTF) of surfaces on site in real world application scenarios. The main principle of our lightweight BTF acquisition gantry is a compact hemispherical skeleton with cameras along the meridian and with light emitting diode (LED) modules shining light onto a sample surface. The proposed device is portable and achieves a high speed of measurement while maintaining high degree of accuracy. While the positions of the LEDs are fixed on the hemisphere, the cameras allow us to cover the range of the zenith angle from 0∘ to 75∘ and by rotating the cameras along the axis of the hemisphere we can cover all possible camera directions. This allows us to take measurements with almost the same quality as existing stationary BTF gantries. Two degrees of freedom can be set arbitrarily for measurements and the other two degrees of freedom are fixed, which provides a tradeoff between accuracy of measurements and practical applicability. Assuming that a measured sample is locally flat and spatially accessible, we can set the correct perpendicular direction against the measured sample by means of an auto-collimator prior to measuring. Further, we have designed and used a marker sticker method to allow for the easy rectification and alignment of acquired images during data processing. We show the results of our approach by images rendered for 36 measured material samples.