Characterization and potential of periosteum-derived cells: an overview

As a thin fibrous layer covering the bone surface, the periosteum plays a significant role in bone physiology during growth, development and remodeling. Over the past several decades, the periosteum has received considerable scientific attention as a source of mesenchymal stem cells (MSCs). Periosteum-derived cells (PDCs) have emerged as a promising strategy for tissue engineering due to their chondrogenic, osteogenic and adipogenic differentiation capacities. Starting from the history of PDCs, the present review provides an overview of their characterization and the procedures used for their isolation. This study also summarizes the chondrogenic, osteogenic, and adipogenic abilities of PDCs, serving as a reference about their potential therapeutic applications in various clinical scenarios, with particular emphasis on the comparison with other common sources of MSCs. As techniques continue to develop, a comprehensive analysis of the characterization and regulation of PDCs can be conducted, further demonstrating their role in tissue engineering. PDCs present promising potentials in terms of their osteogenic, chondrogenic, and adipogenic capacities. Further studies should focus on exploring their utility under multiple clinical scenarios to confirm their comparative benefit over other commonly used sources of MSCs

Machine learning-based anomaly detection of groundwater microdynamics: case study of Chengdu, China

Abstract Detection of subsurface hydrodynamic anomalies plays a significant role in groundwater resource management and environmental monitoring. In this paper, based on data from the groundwater level, atmospheric pressure, and precipitation in the Chengdu area of China, a method for detecting outliers considering the factors affecting groundwater levels is proposed. By analyzing the factors affecting groundwater levels in the monitoring site and eliminating them, simplified groundwater data is obtained. Applying sl-Pauta (self-learning-based Pauta), iForest (Isolated Forest), OCSVM (One-Class SVM), and KNN to synthetic data with known outliers, testing and evaluating the effectiveness of 4 technologies. Finally, the four methods are applied to the detection of outliers in simplified groundwater levels. The results show that in the detection of outliers in synthesized data, the OCSVM method has the best detection performance, with a precision rate of 88.89%, a recall rate of 91.43%, an F1 score of 90.14%, and an AUC value of 95.66%. In the detection of outliers in simplified groundwater levels, a qualitative analysis of the displacement data within the field of view indicates that the outlier detection performance of iForest and OCSVM is better than that of KNN. The proposed method for considering the factors affecting groundwater levels can improve the efficiency and accuracy of detecting outliers in groundwater level data

An Investigation of the Influences of SWOT Sampling and Errors on Ocean Eddy Observation

The mission of Surface Water and Ocean Topography (SWOT) is scheduled to be launched in 2022, and global ocean eddies with radius scales of larger than 10 km are expected to be observed from space. However, there are still open questions about the capability of SWOT to detect ocean eddies. Based on ocean model data and SWOT orbit, this study simulates along-track observation of SWOT. Two eddy datasets are derived from simulated observation data via mapping and eddy identification procedures, one of which includes SWOT errors and the other does not. The third eddy dataset is generated from the original model data. Through comparing these three eddy datasets, it is found that 34% (40%) eddies are lost due to insufficient temporal sampling and errors in the Kuroshio Extension (South China Sea) region, and numerous artifact eddies are generated. To further explain the influence of SWOT errors on smaller-scale eddies, two eddies (a cyclonic eddy and an anticyclonic eddy) with the radius of about 10 km are repeatedly observed 100 times using the SWOT-simulator. The cyclonic eddy with larger amplitude has been detected 84 times, while the anticyclonic eddy is visible 76 times. Therefore, the influence of the SWOT sampling and errors on ocean eddy observation is revealed by the results of these observing system simulation experiments (OSSEs)

Experimental study on confined compression deformation and breakage characteristics for different types of coal particles

Dynamic disasters such as coal and gas outburst seriously restrict the safety of mine production. Different types of coal particles reflect the coal structure, mechanical characteristics and energy storage behavior under load, which is of great significance to the study of coal and gas outburst disasters. However, there is little research on the coal particles breakage characteristics at present. In this study, raw coal and tectonic coal particles were selected to carry out confined compression experiments under different particle size distributions and stress conditions. The results show that the loading process is divided into slip stage, breakage stage and consolidation stage in turn. The deformation resistance of tectonic coal is weaker than that of raw coal in slip stage and breakage stage, but its strain hardening tendency is obviously stronger in compression stage than that of raw coal. Although the stress has a great influence on the relative breakage rate of coal particles, it has a weak influence at the consolidation stage. Due to the unstable structure of some coal particles in the middle particle size during loading, obvious particle size loss occurs after loading. At the same time, particle size distribution also affects the coal particle breakage. The relative breakage rate of large-size sample in single-graded sample group is higher and that of mixed-graded sample group is lower than that of single-graded sample group as a whole. Compared with the raw coal, the absolute breakage rate of large and medium size coal particles of tectonic coal is higher, and tends to break into smaller size coal particles during breakage process. The breakage degree of tectonic coal particles is always higher than that of raw coal. In general, strain hardening of tectonic coal particles is obvious, breakage degree is high, and even presents rheological characteristics in the experiment, which is the basic reason for low porosity and low permeability of tectonic coal. Moreover, most of the energy input to tectonic coal particles from outside is dissipated by friction, breakage and plastic deformation of coal particles, so the elastic energy stored in them is low

Chiral π-Conjugated Double Helical Aminyl Diradical with Triplet Ground State

We report a neutral high-spin diradical of chiral C2-symmetric bis[5]diazahelicene with ΔEST ≈ 0.4 kcal mol-1, as determined by EPR spectroscopy/SQUID magnetometry. The diradical is the most persistent among all high-spin aminyl radicals reported to date by a factor of 20, with a half-life up to 6 days in 2-MeTHF at room temperature. Its triplet ground state and excellent persistence may be associated with the unique spin density distribution within the dihydrophenazine moiety, characterizing two effective 3-electron C-N bonds analogous to the N-O bond of nitroxide radical. The enantiomerically enriched (ee ≥ 94%) (MM)- and (PP)-enantiomers of the precursors to the diradicals are obtained by either preparative chiral supercritical flow chromatography (SFC) or resolution via functionalization with chiral auxiliary of the C2-symmetric racemic tetraamine. The barrier for racemization of the solid tetraamine is ΔG‡ = 43 ± 0.01 kcal mol-1 in the 483 – 523 K range. The experimentally estimated lower limit of the barrier for racemization of diradical, ΔG‡ ≥ 26 kcal mol-1 in 2-MeTHF at 293 K, is comparable to the DFT-determined barrier of ΔG‡ = 31 kcal mol-1 in the gas phase at 298 K. While the enantiomerically pure tetraamine displays strong chiroptical properties, with anisotropy factor |g| = |Δε|/ε = 0.036 at 376 nm, |g| ≈ 0.005 at 548 nm of the high-spin diradical is comparable to that recently reported triplet ground state diradical dication. Notably, the radical anion intermediate in the generation of diradical exhibits large SOMO-HOMO inversion, SHI = 35 kcal mol-1

A case of placental trisomy 18 mosaicism causing a false negative NIPT result

Abstract Background The non-invasive prenatal testing that evaluates circulating cell free DNA, and has been established as an additional pregnancy test for detecting the common fetal trisomies 21, 18 and 13 is rapidly revolutionizing prenatal screening as a result of its increased sensitivity and specificity. However, false positive and false negative results still exist. Case presentation We presented a case in which the non-invasive prenatal testing results were normal at 15 gestational age (GA), but an ultrasound examination at 30GA showed that the fetus had heart abnormalities, and the third trimester ultrasound at 33GA noted multiple anomalies including a 3.0 mm ventricular septal defect. Along with cordocentesis at 33GA, the cord blood sample cytogenetics analysis showed a mos 47,XN,+18[61]/46,XN[39] T18 karyotype. Six placental biopsies confirmed that the chromosome 18 placenta chimerism ratio had changed from 33% to 72%. Ultimately, the pregnancy was interrupted at 34GA. Conclusions We presented this case to highlight the need to clearly explain false positive or false negative results to patients. We believe that this information will also influence the development of future diagnostic test methodologies

Changes in optical coherence tomography biomarkers in eyes with advanced idiopathic epiretinal membrane treated with dexamethasone implantation

Abstract Purpose To investigate the effects of vitrectomy and intravitreal dexamethasone (DEX) implantation on retinal biomarkers in patients with advanced idiopathic epiretinal membrane (IERM) and to evaluate this treatment’s anatomical and functional outcomes. Methods This retrospective study included 41 patients with advanced IERM who underwent vitrectomy and were divided into a pars plana vitrectomy (PPV) group (20 eyes) and a dexamethasone (DEX) group (21 eyes) based on intravitreal DEX implantation. We collected data on best-corrected visual acuity (BCVA), central macular thickness (CMT), disorganization of the retinal inner layers (DRIL), subretinal fluid, intraretinal cystoid changes (IRC), integrity of the inner-outer segment layer, and intraocular pressure. Results BCVA improved significantly in both groups; the DEX group had a higher visual acuity gain at 1 and 6 months (P = 0.002 and 0.023, respectively). Postoperative CMT gradually decreased in both groups, with the DEX group showing a greater decrease at 1 and 6 months (P = 0.009 and 0.033, respectively). Six months after surgery, the DRIL and IRC grades in the DEX group were significantly improved compared to those in the PPV group (P = 0.037 and 0.038, respectively). Multivariate regression analyses revealed that patients with intraoperative DEX implants were more likely to have a significant CMT reduction (≥ 100 μm) from baseline (odds ratio (OR), 9.44; 95% confidence intervals (CI), 1.58–56.56; P = 0.014) at 6 months and less likely to exhibit DRIL at 6 months postoperatively (OR, 0.08; 95% CI, 0.01–0.68; P = 0.021). Conclusion Vitrectomy combined with intravitreal DEX implantation facilitates the recovery of postoperative visual acuity and improvement of anatomical outcomes in patients with advanced IERM, effectively reducing CMT and improving DRIL

PDCoV nsp5 cleaves POLDIP3 through its protease activity.

(A) PDCoV nsp5 cleaves POLDIP3. IPEC-J2 cells were co-transfected with plasmids of POLDIP3-HA and PDCoV nsp5-Flag or empty vector, and then cell samples were collected at 30 h post-transfection for Western blotting analysis. (B) POLDIP3 cleavage in a PDCoV nsp5 dose-dependent manner. IPEC-J2 cells were co-transfected with POLDIP3-HA and increased quantities of PDCoV nsp5-Flag or empty vector. Cell lysates were prepared and analyzed by Western blotting at 30 h post-transfection. (C) PDCoV nsp5 cleaves POLDIP3 depending on its protease activity. IPEC-J2 cells were transfected with POLDIP3-HA along with the wild-type PDCoV nsp5-Flag (nsp5) or its protease-defective mutant (nsp5 H41A or nsp5 C144A). After 30 h post-transfection, cells were collected and lysed for Western blotting. (D) PDCoV nsp5-mediated cleavage of POLDIP3 independent of proteasome degradation and autophagy. IPEC-J2 cells transfected with POLDIP3-HA and PDCoV nsp5-Flag were treated with MG132 (10 μM) or 3-MA (5 mM), followed by detection of cleavage by Western blotting. (E) PDCoV infection induces POLDIP3 cleavage. IPEC-J2 cells were infected with PDCoV and harvested to detect POLDIP3 expression and cleavage at 24 h post-infection.</p