Contrast-enhanced microCT evaluation of degeneration following partial and full width injuries to mouse lumbar intervertebral disc

Study Design: Preclinical animal study. Objective: Evaluation of the degenerative progression resulting from either a partial- or full- width injury to the mouse lumbar intervertebral disc (IVD) using contrast-enhanced micro-computed tomography and histological analyses. We utilized a lateral-retroperitoneal surgical approach to access the lumbar IVD, and the injuries to the IVD were induced by either incising one side of the annulus fibrosus or puncturing both sides of the annulus fibrosus. The full-width injury caused dramatic reduction in nucleus pulposus hydration and significant degeneration. A partial-width injury produces localized deterioration around the annulus fibrosus site that resulted in local tissue remodeling without gross degeneration to the IVD. Methods: Female C57BL/6J mice of 3-4 months age were used in this study. They were divided into three groups to undergo a partial-width, full-width, or sham injuries. The L5/L6 and L6/S1 lumbar IVDs were surgically exposed using a lateral-retroperitoneal approach. The L6/S1 IVDs were injured using either a surgical scalpel (partial-width) or a 33G needle (full-width), with the L5/L6 serving as an internal control. These animals were allowed to recover and then sacrificed at 2-, 4-, or 8- weeks post-surgery. The IVDs were assessed for degeneration using contrast-enhanced microCT (CEμCT) and histological analysis. Results: The high-resolution 3D evaluation of the IVD confirmed that the respective injuries localized within one side of the annulus fibrosus or spanned the full width of the IVD. The full-width injury caused deteriorations in the nucleus pulposus after 2 weeks that culminated in significant degeneration at 8 weeks, while the partial width injury caused localized disruptions that remained limited to the annulus fibrosus. Conclusion: The use of CEμCT revealed distinct IVD degeneration profiles resulting from partial- and full- width injuries. The partial width injury may serve as a better model for IVD degeneration resulting from localized annulus fibrosus injuries in humans.

Predicting Diameter Increase Using a Quadriceps Tendon Augmentation for Undersized Hamstring Grafts in ACL Reconstruction

Background The failure rate for ACL reconstruction varies between 5 to 25% depending on the population. Recent studies found a higher failure rate with grafts of 8 millimeters in diameter or less. Various options are described when the graft’s diameter is inferior to the target value, but little literature helps us predict the final diameter during surgeries. Therefore, this study’s goal is to describe a new technique supplementing a hamstring graft folded in half with a quadricipital tendon band of partial width and thickness (4S+Q), and to predict the final diameter. Methods Thirty-three cadaveric knees were dissected in order to harvest semitendinosus and gracilis tendons (4S) along with a 6mm wide tendon band from the rectus femoris. Harvesting was done according to the usual surgical technique. Measures of length and diameter in 4S and 4S+Q configurations were performed separately by three evaluators. Results The threshold diameter of 8,5 mm was attained in only 30% of 4S grafts within our population in comparison with 88% when augmented with a quadriceps band. The average diameter increase with the 4S+Q configuration was 1,49 mm. A threshold of 7,5 mm was established for the applicability of this augmentation technique considering that 93% of the grafts measuring 7,5 mm or more reached the 8,5mm target. Conclusions The 4S+Q configuration offers a salvage option worth adding to one’s arsenal, significantly increasing the graft’s diameter. The width of the quadricipital tendon sample can be adjusted and will need further study.

A phenomenological analysis on isospin-violating decay of X(3872)

In a molecular scenario, we investigate the isospin-breaking hidden charm decay processes of X(3872), i.e., $$X(3872) \rightarrow \pi ^+ \pi ^- J/\psi $$ X ( 3872 ) → π + π - J / ψ , $$X(3872) \rightarrow \pi ^+ \pi ^- \pi ^0 J/\psi $$ X ( 3872 ) → π + π - π 0 J / ψ , and $$X(3872)\rightarrow \pi ^0\chi _{cJ}$$ X ( 3872 ) → π 0 χ cJ . We assume that the source of the strong isospin violation comes from the different coupling strengths of X(3872) to its charged components $$D^{*+} D^-$$ D ∗ + D - and neutral components $$D^{*0 } {\bar{D}}^0$$ D ∗ 0 D ¯ 0 as well as the interference between the charged meson loops and neutral meson loops. The former effect could fix our parameters by using the measurement of the ratio $$\Gamma [X(3872) \rightarrow \pi ^+ \pi ^- \pi ^0 J/\psi ]/\Gamma [X(3872) \rightarrow \pi ^+ \pi ^- J/\psi ]$$ Γ [ X ( 3872 ) → π + π - π 0 J / ψ ] / Γ [ X ( 3872 ) → π + π - J / ψ ] . With the determined parameter range, we find that the estimated ratio $$\Gamma [X(3872) \rightarrow \pi ^0 \chi _{c1}/\Gamma [X(3872) \rightarrow \pi ^+ \pi ^- J/\psi ]$$ Γ [ X ( 3872 ) → π 0 χ c 1 / Γ [ X ( 3872 ) → π + π - J / ψ ] is well consistent with the experimental measurement from the BESIII collaboration. Moreover, the partial width ratio of $$\pi ^0 \chi _{cJ}$$ π 0 χ cJ for $$J=0,1,2$$ J = 0 , 1 , 2 is estimated to be $$1.77{-}1.65:1:1.09{-}1.43$$ 1.77 - 1.65 : 1 : 1.09 - 1.43 , which could be tested by further precise measurements of BESIII and Belle II.

Fusion cross-sections for deuterium cycle fusion reactors (D-cycle): an analysis of geometric, Gamow-Sommerfeld and astrophysical S-factors

Fusion reactions in the deuterium cycle (D+D, D+T and D+3He) are the main nucleus-nucleus interactions which occur in tokamaks and stellerators. These reactions are the limiting case between the Woods-Saxon potential field at nuclear distances and the Coulomb electrostatic potential (scattering) at longer distances. In this paper several fusion cross-sections, geometric, Gamow-Sommerfeld and astrophysical S-factors have been reviewed and compared with experimental data from the last ENDF/B-VIII.0 cross-section library. The XDC-fusion code has been developed to calculate fusion cross-sections, geometric, Gamow-Sommerfeld and S-factors of the deuterium-cycle (D-cycle), including resonance parameters (energy and partial width). The software estimates also fusion reaction heat (Q) and Woods-Saxon/Coulomb proximity potentials. Although relative differences between fusion cross-sections are lower than 5 %, S-factors present considerable differences between the energies and partial width (FWHM) of the single-level Breit-Wigner (SLBW) resonances. The energy at which is placed the maximum fusion cross-section is also different between cases. In conclusion, fusion reaction models for light nuclei (deuterium, tritium and helium) should be reviewed in order to apply fusion to energy production in safety conditions.

Enhanced $\Gamma(p\to K^0\mu^+)/\Gamma(p\to K^+\bar{\nu}_\mu)$ as a signature of minimal renormalizable SUSY SO (10) GUT

The ratio of the partial widths of some dimension-5 proton decay modes can be predicted without detailed knowledge of supersymmetric (SUSY) particle masses, and this allows us to experimentally test various SUSY grand unified theory (GUT) models without discovering SUSY particles. In this paper, we study the ratio of the partial widths of the $p\to K^0\mu^+$ and $p\to K^+\bar{\nu}_\mu$ decays in the minimal renormalizable SUSY $SO(10)$ GUT, under only a plausible assumption that the 1st- and 2nd-generation left-handed squarks are mass-degenerate. In the model, we expect that the Wilson coefficients of dimension-5 operators responsible for these modes are on the same order and that the ratio of $p\to K^0\mu^+$ and $p\to K^+\bar{\nu}_\mu$ partial widths is $O(0.1)$. Hence, we may be able to detect both $p\to K^0\mu^+$ and $p\to K^+\bar{\nu}_\mu$ decays at Hyper-Kamiokande, thereby gaining a hint for the minimal renormalizable SUSY $SO(10)$ GUT. Moreover, since this partial width ratio is quite suppressed in the minimal $SU(5)$ GUT, it allows us to distinguish the minimal renormalizable SUSY $SO(10)$ GUT from the minimal $SU(5)$ GUT. In the main body of the paper, we perform a fitting of the quark and lepton masses and flavor mixings with the Yukawa couplings of the minimal renormalizable $SO(10)$ GUT, and derive a concrete prediction for the partial width ratio based on the fitting results. We find that the partial width ratio generally varies in the range $0.05$–$0.6$, confirming the above expectation.

Resonance width for a particle–core coupling model with a square-well potential

We derive a compact formula for the width of a multi-channel resonance state. To this end, we use a deformed square-well potential and solve the coupled-channels equations. We obtain the $S$-matrix in the Breit–Wigner form, from which partial widths can be extracted. We apply the resultant formula to a deformed nucleus and discuss the behavior of partial width for an $s$-wave channel.

Covariance generation for the prompt neutron multiplicity of 239Pu including the (n,γf) process

Fission cross section of 239Pu can be seen as a sum of the “immediate" fission and “two-step" (n,γf) reactions. In the Resolved Resonance Range of the reaction cross sections, the contribution of the (n,γf) process has an impact on the determination of the partial widths magnitude involved in the Reich-Moore approximation of the R-matrix theory. The present work aims to investigate this impact by using the CONRAD code and the partial width Γγf for the (n,γf) reaction calculated by Lynn et al. [1]. A special attention will be paid to the covariance matrix obtained on νp.

Screening effects on resonant thermonuclear reaction rates

The reaction rate of several astrophysically important nuclear reactions is dominated by the contribution of narrow resonances at the astrophysically most effective energies. In the stellar plasma the partial width of the resonances in the entrance channel is modified due to screening corrections. This effect, so far ignored in stellar reaction network calculations, reduces the conventional Salpeterscreening enhancement of the reaction rate. We derive analytical screening correction factors for the contributions of narrow resonances to the stellar reaction rate and discuss the effects for UC (a, j)lsO, 150(a,7)19 Ne and other reactions of relevance to explosive hydrogen burning