12,108 research outputs found
Growth Stimulation of Biological Cells and Tissue by Electromagnetic Fields and Uses Thereof
The present invention provides systems for growing two or three dimensional mammalian cells within a culture medium facilitated by an electromagnetic field, and preferably, a time varying electromagnetic field. The cells, and culture medium are contained within a fixed or rotating culture vessel, and the electromagnetic field is emitted from at least one electrode. In one embodiment, the electrode is spaced from the vessel. The invention further provides methods to promote neural tissue regeneration by means of culturing the neural cells in the claimed system. In one embodiment, neuronal cells are grown within longitudinally extending tissue strands extending axially along and within electrodes comprising electrically conductive channels or guides through which a time varying electrical current is conducted, the conductive channels being positioned within a culture medium
Ultrafast photophysics and photochemistry of radical precursors in solution
The photoinduced dynamics of radical precursors in solution were investigated by means of femtosecond transient absorption spectroscopy assisted by quantum chemical calculations. The investigated systems show a wide range of excited state lifetimes ranging from tens of femtoseconds to nanoseconds. Thus, in the first case, on the investigated time scale the dynamics of the generated radicals can be additionally investigated. In the latter case only the excited singlet lifetime is observable
Femtosecond photoelectron and photoion spectrometer with vacuum ultraviolet probe pulses
We describe a setup to study ultrafast dynamics in gas-phase molecules using
time-resolved photoelectron and photoion spectroscopy. The vacuum ultraviolet
(VUV) probe pulses are generated via strong field high-order harmonic
generation from infrared femtosecond laser pulses. The band pass characteristic
in transmission of thin indium (In) metal foil is exploited to isolate the
harmonic of the 800 nm fundamental (H9, 14 eV, 89 nm) from all
other high harmonics. The harmonic is obtained with high
conversion efficiencies and has sufficient photon energy to access the complete
set of valence electron levels in most molecules. The setup also allows for
direct comparison of VUV single-photon probe with 800 nm multi-photon probe
without influencing the delay of excitation and probe pulse or the beam
geometry. We use a magnetic bottle spectrometer with high collection efficiency
for electrons, serving at the same time as a time of flight spectrometer for
ions. Characterization measurements on Xe reveal the spectral width of H9 to be
meV and a photon flux of photons/pulse after
spectral filtering. As a first application, we investigate the S excitation
of perylene using time-resolved ion spectra obtained with multi-photon probing
and time-resolved electron spectra from VUV single-photon probing. The time
resolution extracted from cross-correlation measurements is fs for
both probing schemes and the pulse duration of H9 is found to be fs
Growth stimulation of biological cells and tissue by electromagnetic fields and uses thereof
The present invention provides systems for growing two or three dimensional mammalian cells within a culture medium facilitated by an electromagnetic field, and preferably, a time varying electromagnetic field. The cells and culture medium are contained within a fixed or rotating culture vessel, and the electromagnetic field is emitted from at least one electrode. In one embodiment, the electrode is spaced from the vessel. The invention further provides methods to promote neural tissue regeneration by means of culturing the neural cells in the claimed system. In one embodiment, neuronal cells are grown within longitudinally extending tissue strands extending axially along and within electrodes comprising electrically conductive channels or guides through which a time varying electrical current is conducted, the conductive channels being positioned within a culture medium
Three-Dimensional Co-Culture Process
By the process of the present invention a variety of cells may be co-cultured to produce tissue which has 3-dimensionality and had some of the characteristics of in vivo tissue. The process provides enhanced 3-dimensional tissue which creates a multicellular organoid differentiation model
Pathogen propagation in cultured three-dimensional tissue mass
A process for propagating a pathogen in a three-dimensional tissue mass cultured at microgravity conditions in a culture vessel containing culture media and a culture matrix is provided. The three-dimensional tissue mass is inoculated with a pathogen and pathogen replication in the cells of the tissue mass achieved
Ultrafast photophysics and photochemistry of radical precursors in solution
The photoinduced dynamics of radical precursors in solution were investigated by means of femtosecond transient absorption spectroscopy assisted by quantum chemical calculations. The investigated systems show a wide range of excited state lifetimes ranging from tens of femtoseconds to nanoseconds. Thus, in the first case, on the investigated time scale the dynamics of the generated radicals can be additionally investigated. In the latter case only the excited singlet lifetime is observable
Root canal morphology of the mandibular second premolar: a systematic review and meta- analysis
Background: The aim of this paper was to systematically review the root canal configuration (RCC) and morphology literature of the mandibular second premolar (Mn2P).
Methods: Systematic research of five electronic databases was performed to identify published literature concerning the root canal configuration (RCC) of the Mn2P up through July 2020. Studies were selected according to predefined search terms and keywords inclusion criteria: âroot canal configurationâ, âroot canal systemâ, âroot canal morphologyâ, âmandibular second premolarâ, âmandibular premolarsâ, âmorphologyâ and âanatomyâ. Further possible studies were identified by cross-referencing and screening the bibliographies of the selected articles.
Results: From 1622 retrieved studies, 44 studies investigating the internal morphology of 17,839 Mn2Ps were included. Most examined Mn2Ps were single-rooted (89.5â100%); two-rooted (0.1â8%) and three-rooted (0.1â3.5%) Mn2Ps at lower frequency. Most frequent RCCs reported were 1â1â1/1 (55.3â99.6%) followed by 1â1â2/2 (0.5â57%) and 2â2â2/2 (0.6â18%). The meta-analysis of seven studies demonstrated that a significantly higher number of RCC type 1â2â1/1 (OR [95%CI] = 2.05 [1.27, 3.33]) and 2â2â2/2 (OR [95%CI] = 2.32 [0.65, 8.63]) were observed in male than in female patients.
Conclusions: Different RCC research methods have been reported. Whereas clearing and radiographs were com- monly used in the past, CBCT has been prevalent in recent years. A globally high frequency of a 1â1â1/1 RCC in the Mn2P has been reported. Nevertheless, the probability that different, more complicated RCCs can appear in Mn2Ps should not be underestimated and, thus, should be taken into consideration when making decisions during an endo- dontic treatment
Hyperdeterminants as integrable discrete systems
We give the basic definitions and some theoretical results about
hyperdeterminants, introduced by A. Cayley in 1845. We prove integrability
(understood as 4d-consistency) of a nonlinear difference equation defined by
the 2x2x2-hyperdeterminant. This result gives rise to the following hypothesis:
the difference equations defined by hyperdeterminants of any size are
integrable.
We show that this hypothesis already fails in the case of the
2x2x2x2-hyperdeterminant.Comment: Standard LaTeX, 11 pages. v2: corrected a small misprint in the
abstrac
Intravitreal bevacizumab for the treatment of macular oedema secondary to branch retinal vein occlusion
Purpose: To evaluate the effect of intravitreal bevacizumab (Avastin) injections on visual acuity (VA) and foveal retinal thickness in patients with macular oedema secondary to branch retinal vein occlusion.Methods: A prospective, non-comparative, consecutive, interventional case series of 34 patients. Patients received repeated intravitreal injections of 1.25 mg bevacizumab. Main outcome measures were VA (Snellen charts and ETDRS) and retinal thickness (optical coherence tomography measurements) in a follow-up period of 6 months.Results: Patients presented at a mean age of 69 years (range 44--86). Mean duration of symptoms was 40 weeks (range 1--300). Mean (SD) VA at baseline was 0.79 (0.39) logMAR, improving to 0.51 (0.34) logMAR at 6 months (p = 0.009). Mean number of letters on the ETDRS chart at baseline was 45.3 (19.0), improving to 60.6 (19.9) at 6 months (p = 0.003). Mean (SD) retinal thickness at baseline was 474 (120) \textgreekmm, declining to 316 (41) \textgreekmm at 6 months.Conclusion: Intravitreal injection of 1.25 mg bevacizumb appears to be an effective treatment option for branch retinal vein occlusion
- âŠ