Age, pelvic incidence, facet joint angle and pedicle-facet angle as correlative factors for isthmic spondylolisthesis: a retrospective case control study.

BACKGROUND: Isthmic spondylolisthesis (IS) is a common clinical disease with a high incidence rate. However, most current researches explain the clear pathogenesis from a single perspective. The aim of our study was to explore the relationships between multiple parameters in patients and find the potential risk factors of this disease. METHODS: Our study retrospectively included 115 patients who were diagnosed with isthmic spondylolisthesis and the same number of individuals without spondylolisthesis. The following parameters were measured or collected: age, pelvic incidence (PI), facet joint angle (FJA) and pedicle-facet angle (P-F angle). The radiographic files were imported into Mimics Medical 20.0 and all collected data were analyzed using SPSS, version 26.0, statistical software. RESULTS: The age was higher in IS group than in control group. PI was also higher in the IS group (50.99 ± 7.67) than in the control group (43.77 ± 9.30) significantly (P = 0.009). There was significant difference in cranial and average FJA tropism in L3-L4 level (P = 0.002, P = 0.006, respectively) and in L4-L5 level (P < 0.001). P-F angle of L4-L5 level showed significantly larger in IS group than in control group (P = 0.007).The logistic regression analysis showed a larger age, a greater L3-L4 cranial FJA tropism, and a greater L4-L5 cranial FJA tropism were potential predictors of IS, with an OR of 1.07, 1.28, and 1.39 respectively. The thresholds of the predictors were 60 years, 5.67°, and 8.97° according to the ROC curve. The linear regression equation was established: degree of slippage (%) = 0.220*age - 0.327* L3-4 cranial FJA tropism - 0.346* L4-5 average FJA tropism (F = 3.460, P = 0.011, r = 0.659). CONCLUSIONS: Our study revealed that isthmic spondylolisthesis may be related to multiple factors rather than a single factor. Age, PI, PJA and P-F angle are potentially associated with spondylolisthesis.

Recovery of rare earth elements from waste phosphors via alkali fusion roasting and controlled potential reduction leaching.

Waste phosphors, which contain the quantity of rare earth and toxic metals, need to be recycled for both environmental protection and the sustainable development of rare earth resources. Due to the magnesium-aluminum spinel structure, it is difficult to extract cerium and terbium from waste phosphors. In this study, a facile process for recovering rare earth elements from waste phosphors was developed. First, the waste phosphors were alkali roasted to destroy the aluminum-magnesium spinel structure in the blue and green powders. NaOH was found to be a more suitable additive than Na2CO3, NaHCO3, and K2CO3 for alkali roasting. Then, the roasted slag was washed with water to remove the aluminum and controlled potential reduction leaching was conducted. FeCl2 was used as the reductant (dosage of 0.04) in the 3 mol·L-1 HCl solution at a leaching temperature of 50 °C for 60 min. The leaching efficiencies of Y, Eu, Ce, and Tb were up to 99.1 %, 99.4 %, 98.6 %, and 98.8 %, respectively. The reduction leaching process obeys the shrinking core model and depends on the diffusion. This process can effectively improve the leaching efficiency of rare earth elements from waste phosphors and provides theoretical and technical support for the recycling of waste phosphors.

Identification of a Locus Conferring Dominant Susceptibility to Pyrenophora tritici-repentis in Barley.

The fungus Pyrenophora tritici-repentis (Ptr) causes tan spot, a destructive foliar disease of wheat worldwide. The pathogen produces several necrotrophic effectors, which induce necrosis or chlorosis on susceptible wheat lines. Multiple races of Ptr have been identified, based on their ability to produce one or more of these effectors. Ptr has a wide host range of cereal and non-cereal grasses, but is known to cause damage only on wheat. Previously, we showed that Ptr can interact specifically with cultivated barley (Hordeum vulgare ssp. vulgare), and that the necrotrophic effector Ptr ToxB induces mild chlorosis in a highly selective manner when infiltrated into certain barley genotypes. In the present study, a barley doubled-haploid (DH) population was evaluated for reaction to Ptr race 5, a Ptr ToxB-producer. Then a comprehensive genetic map composed of 381 single nucleotide polymorphism (SNP) markers was used to map the locus conditioning this chlorosis. The F1 seedlings, and 92 DH lines derived from a cross between the resistant Japanese malting barley cultivar Haruna Nijo and the susceptible wild barley (H. vulgare ssp. spontaneum) OUH602 were inoculated with a conidial suspension of Ptr race 5 isolate at the two-leaf stage. The seedlings were monitored daily for symptoms and assessed for chlorosis development on the second leaf, 6 days after inoculation. All tested F1 seedlings exhibited chlorosis symptoms similar to the susceptible parent, and the DH lines segregated 1:1 for susceptible:resistant phenotypes, indicating the involvement of a single locus. Marker-trait linkage analysis based on interval mapping identified a single locus on the distal region of the short arm of chromosome 2H. We designate this locus Susceptibility to P. tritici-repentis1 (Spr1). The region encompassing this locus has 99 high confidence gene models, including membrane receptor-like kinases (RLKs), intracellular nucleotide-binding, leucine-rich repeat receptors (NLRs), and ankyrin-repeat proteins (ANKs). This shows the involvement of a dominant locus conferring susceptibility to Ptr in barley. Further work using high-resolution mapping and transgenic complementation will be required to identify the underlying gene.