In Vitro and In Vivo Study

Nanofibers have attracted increasing attention in drug delivery and other biomedical applications due to their some special properties. The present study aims to prepare a fiber-based nanosolid dispersion system to enhance the bioavailability of curcumin (CUR). CUR-loaded polyvinyl pyrrolidone (CUR@PVP) nanofibers were successfully prepared via electrospinning. Scanning electron microscopy (SEM) was employed to observe the morphology of the nanofibers, and the SEM image showed that the drug-loaded nanofibers were smooth, and no CUR clusters were found on the surface of the nanofibers. The results of X-ray diffraction (XRD) demonstrated that the CUR was evenly distributed in the nanofibers in an amorphous state. Fourier transform infrared (FTIR) spectroscopy analysis indicated that intermolecular hydrogen bonding occurred between the CUR and the polymer matrix. In vitro dissolution profiles showed that CUR@PVP nanofiber could be quickly dissolved in phosphate-buffered saline (PBS) solution, while negligible dissolution was observed in pure CUR sample. Importantly, in vitro cell viability assays and in vivo animal tests revealed that the nanosolid dispersion system dramatically enhanced the bioavailability and showed effective anticancer effect of the CUR

The older the better: The characteristic of localized prostate cancer in Chinese men

AbstractObjectiveTo assess the clinicopathological features and overall survival between two groups of Chinese patients older or younger than 70 years after retropubic radical prostatectomy.MethodsFrom January 2001 to February 2010, 390 patients receive dretropubic radical prostatectomy. After excluding 89 patients with adjuvant or neoadjuvant hormonal therapy or radiotherapy, a total of 301 patients were included in this study. We arbitrarily divided these patients into younger age group (<70 years, 140 cases, 46.5%) and older age group (≥70 years, 161 cases, 53.5%). The differences in serum prostate specific antigen (PSA), Gleason score, clinical tumor stage, and biochemical-free survival were analyzed between the two groups.ResultsThere were not significant differences between the two groups in high Gleason score rate and clinical tumor stage. However, older patients had significantly lower biochemical recurrence rate than those of younger patients, and had significantly higher PSA levels. Multivariate analysis showed that older age, PSA level and clinical tumor stage were significantly associated with biochemical recurrence free survival.ConclusionIn Chinese men, older age (≥70 years) is associated with better outcome. If the physical condition permits, older age alone should not exclude patients from radical prostatectomy

One-stop stroke management platform reduces workflow times in patients receiving mechanical thrombectomy

Background and purposeClinical outcome in patients who received thrombectomy treatment is time-dependent. The purpose of this study was to evaluate the efficacy of the one-stop stroke management (OSSM) platform in reducing in-hospital workflow times in patients receiving thrombectomy compared with the traditional model.MethodsThe data of patients who received thrombectomy treatment through the OSSM platform and traditional protocol transshipment pathway were retrospectively analyzed and compared. The treatment-related time interval and the clinical outcome of the two groups were also assessed and compared. The primary efficacy endpoint was the time from door to groin puncture (DPT).ResultsThere were 196 patients in the OSSM group and 210 patients in the control group, in which they were treated by the traditional approach. The mean DPT was significantly shorter in the OSSM group than in the control group (76 vs. 122 min; P &lt; 0.001). The percentages of good clinical outcomes at the 90-day time point of the two groups were comparable (P = 0.110). A total of 121 patients in the OSSM group and 124 patients in the control group arrived at the hospital within 360 min from symptom onset. The mean DPT and time from symptom onset to recanalization (ORT) were significantly shorter in the OSSM group than in the control group. Finally, a higher rate of good functional outcomes was achieved in the OSSM group than in the control group (53.71 vs. 40.32%; P = 0.036).ConclusionCompared to the traditional transfer model, the OSSM transfer model significantly reduced the in-hospital delay in patients with acute stroke receiving thrombectomy treatment. This novel model significantly improved the clinical outcomes of patients presenting within the first 6 h after symptom onset

The Criteria of Underground Rock Structure Failure and Its Implication on Rockburst in Roadway: A Numerical Method

Rockburst in roadway happened along with a large-scale destruction of the surrounding rock. To study the failure laws of the surrounding rock in the process of rockburst in roadway, the evolution behaviors of the plastic zone and the criteria of large-scope failure were studied by using FLAC numerical simulation. Meanwhile, the stress response laws of the plastic zone were studied by loading or unloading in a single direction. The results showed that, in the 20 MPa stress environment, large-scale failure zone would appear when the maximum confining pressure was loaded to 50 MPa or the minimum confining pressure was unloaded to 6 MPa. Loading in the direction of maximum confining pressure or unloading in the direction of minimum confining pressure, when the stresses reached a certain limit, could lead to a large-scale expansion to the failure zone of the surrounding rock a roadway. Meanwhile, the stress response of the plastic zone became more sensitive, which might easily trigger rockburst in roadway. In addition, two sine qua nonstress conditions for rockburst in roadway were determined: high stress ratio and high stress level. This might provide a theoretical basis for the stress source mechanism of roadway rockburst

Energy Accumulation Characteristics and Induced Rockburst Mechanism of Roadway Surrounding Rock under Multiple Mining Disturbances: A Case Study

The source of energy release when rockburst occurs must be determined to understand the mechanisms underlying disaster formation and achieve accurate prevention and control. Although previous research has systematically investigated the energy source underlying rockburst from different perspectives, issues such as an unclear understanding of the energy accumulation state and inaccurate positioning of the energy release source remain to be resolved. In this study, the “1·17” major roof accident in the Danshuigou Mine was used as the background to evaluate and analyze the stress environment and energy accumulation characteristics of roadway surrounding rock under multiple mining disturbances, and the results showed that a super energy package occurs in the surrounding rock of the mining roadway. Subsequently, the evolution process of energy in this region and the mechanism of induced rockburst were elaborated. The results showed that the degree of stress concentration in the surrounding rock of the roadway will increase several times as the number of mining disturbances increases. Under the influence of multiple mining disturbances, the maximum principal stress peak of the surrounding rock of the roadway can reach 5–10 times the maximum principal stress value outside the mining-affected area. A large amount of elastic energy was accumulated in the rock surrounding the roadway, and super-high-density energy packages were formed locally. The maximum energy density value reached 50–185 times the value observed in areas outside the mining-affected zone. Thus, rockburst may be induced when the large amount of energy accumulated in the super energy package is suddenly and violently released; moreover, the degree of energy accumulation in the super energy package is likely closely related to the magnitude of rockburst. These results have important theoretical significance and application value for clarifying the mechanism of rockburst and improving the effectiveness of rockburst prediction and prevention

Positive effects of tree species richness on fine-root production in a subtropical forest in SE-China

Aims: Fine roots play an important role in the biogeochemical cycles of terrestrial ecosystems and are vital for understanding forest ecosystem functioning and services. Higher plant species diversity has been largely reported to increase aboveground community biomass, but how biodiversity affects fine-root production and the related mechanisms in forests remain unclear. In this study, we aim to answer two questions: (i) does fine-root production increase with tree species richness? (ii) Can this effect be explained by niche complementarity among species? Methods: We analyzed data from a large forest biodiversity experiment (BEF-China) with 5-year-old trees. Fine-root growth was measured as standing biomass and annual fine-root regrowth was estimated using ingrowth cores. Moreover, relative yield was calculated to test whether over- or under-yielding occurred when mixtures were compared with the average monoculture of the species included in the mixtures. We calculated functional diversity for fine-root (≤2mm in diameter) traits by Rao’s quadratic entropy index for each species mixture. The effects of manipulated tree species richness and identity on fine-root traits were analyzed with linear mixed-effects models. Mixed models were also used to test the relationships between tree species richness and fine-root standing biomass, annual regrowth and vertical heterogeneity. Important Findings: Fine roots of more than one species were found in half of the soil cores in mixtures indicating that belowground interactions in these young forest stands occurred much earlier than canopy closure. We found significant differences among species in fine-root traits such as diameter and specific root length (SRL), which suggested different resource-use strategies and niche partitioning among species. Mean fine-root diameter of species ranged from 0.31 to 0.74mm, mean SRL ranged from 12.43 m·g−1 to 70.22 m·g−1 and mean vertical distribution index β ranged from 0.68 to 0.93. There was a significant positive relationship between species richness and the evenness of the vertical distribution of fine-root standing biomass. Moreover, marginally significant positive relationships existed between species richness and standing biomass as well as annual regrowth of fine roots. Relative yields and Rao’s quadratic entropy index were both not significantly affected by species richness. However, the relative yield of fine-root standing biomass was marginally correlated with Rao’s quadratic entropy index, implying that belowground niche complementarity between species does contribute to diversity effects. In conclusion, our study showed positive effects of species richness on the filling of soil volume by fine roots in the studied experimental forest communities. This has positive effects on fine-root standing biomass and may also lead to increased aboveground biomass

Perfect narrowband circular dichroism based on intrinsic chiral dual quasi-bound states in the continuum in terahertz metasurfaces

Circular dichroism (CD) of chiral structures has wide applications in ultra-sensitive biosensing, wavefront manipulation, and other fields. However, 3D chiral structures require a complex fabrication process, and 2D non-intrinsic chiral structures are difficult to achieve narrow-band perfect CD. Here we proposed a tilted cylindrical structure of a terahertz intrinsic chiral metasurface. Through energy band calculation, topological analysis, multipole decomposition and other research methods, we have realized the separation and merging of topological charges, the degeneracy of modes with opposite polarizations, the free selection of mode eigenstates, and the perfect CD with ultra-high quality (Q) factor. In the study of narrowband chirality, the Q-factor reaches 6822 and the CD reaches 0.99. In addition, both bound states in the continuum (BICs) of the structure exhibit CD at the same time, with Q-factors of 862 and 2673 and CD of –0.98 and 0.98 for the two BICs, respectively. Our work provides new solutions for the study of terahertz narrowband chirality and spin-selective asymmetric transport

Positive effects of tree species richness on fine-root production in a subtropical forest in SE-China

Aims Fine roots play an important role in the biogeochemical cycles of terrestrial ecosystems and are vital for understanding forest ecosystem functioning and services. Higher plant species diversity has been largely reported to increase aboveground community biomass, but how biodiversity affects fine-root production and the related mechanisms in forests remain unclear. In this study, we aim to answer two questions: (i) does fine-root production increase with tree species richness? (ii) Can this effect be explained by niche complementarity among species? Methods We analyzed data from a large forest biodiversity experiment (BEF-China) with 5-year-old trees. Fine-root growth was measured as standing biomass and annual fine-root regrowth was estimated using ingrowth cores. Moreover, relative yield was calculated to test whether over-or under-yielding occurred when mixtures were compared with the average monoculture of the species included in the mixtures. We calculated functional diversity for fine-root (<= 2 mm in diameter) traits by Rao's quadratic entropy index for each species mixture. The effects of manipulated tree species richness and identity on fine-root traits were analyzed with linear mixed-effects models. Mixed models were also used to test the relationships between tree species richness and fine-root standing biomass, annual regrowth and vertical heterogeneity. Important Findings Fine roots of more than one species were found in half of the soil cores in mixtures indicating that belowground interactions in these young forest stands occurred much earlier than canopy closure. We found significant differences among species in fine-root traits such as diameter and specific root length (SRL), which suggested different resource-use strategies and niche partitioning among species. Mean fine-root diameter of species ranged from 0.31 to 0.74 mm, mean SRL ranged from 12.43 m.g(-1) to 70.22 m.g(-1) and mean vertical distribution index beta ranged from 0.68 to 0.93. There was a significant positive relationship between species richness and the evenness of the vertical distribution of fine-root standing biomass. Moreover, marginally significant positive relationships existed between species richness and standing biomass as well as annual regrowth of fine roots. Relative yields and Rao's quadratic entropy index were both not significantly affected by species richness. However, the relative yield of fine-root standing biomass was marginally correlated with Rao's quadratic entropy index, implying that belowground niche complementarity between species does contribute to diversity effects. In conclusion, our study showed positive effects of species richness on the filling of soil volume by fine roots in the studied experimental forest communities. This has positive effects on fine-root standing biomass and may also lead to increased aboveground biomass

Constitutive Equations for Describing the Warm and Hot Deformation Behavior of 20Cr2Ni4A Alloy Steel

Isothermal hot compression tests of 20Cr2Ni4A alloy steel were performed under temperatures of 973&ndash;1273 K and strain rates of 0.001&ndash;1 s&minus;1. The behavior of the flow stress of 20Cr2Ni4A alloy steel at warm and hot temperatures is complicated because of the influence of the work hardening, the dynamic recovery, and the dynamic recrystallization. Four constitutive equations were used to predict the flow stress of 20Cr2Ni4A alloy steel, including the original strain-compensated Arrhenius-type (osA-type) equation, the new modified strain-compensated Arrhenius-type (msA-type) equation, the original Hensel&ndash;Spittel (oHS) equation and the modified Hensel&ndash;Spittel (mHS) equation. The msA-type and mHS are developed by revising the deformation temperatures, which can improve prediction accuracy. In addition, we propose a new method of solving the parameters by combining a linear search with multiple linear regression. The new solving method is used to establish the two modified constitutive equations instead of the traditional regression analysis. A comparison of the predicted values based on the four constitutive equations was performed via relative error, average absolute relative error (AARE) and the coefficient of determination (R2). These results show the msA-type and mHS equations are more accurate and efficient in terms of predicting the flow stress of the 20Cr2Ni4A steel at elevated temperature

Epigenetic landscape in PPARγ2 in the enhancement of adipogenesis of mouse osteoporotic bone marrow stromal cell

AbstractOsteoporosis is one of the most prevalent skeletal system diseases; yet, its pathophysiological mechanisms remain elusive. Adipocytes accumulate remarkably in the bone marrow of osteoporotic patients. The potential processes and molecular mechanisms underlying adipogenesis in osteoporotic BMSCs have attracted significant attention as adipocytes and osteoblasts share common precursor cells. Some environmental factors influence bone mass through epigenetic mechanisms; however, the role of epigenetic modifications in osteoporosis is just beginning to be investigated, and there is still little data regarding their involvement. In the current study, we investigated how epigenetic modifications, including DNA methylation and histone modifications, lead to adipogenesis in the bone marrow during osteoporosis. A glucocorticoid-induced osteoporosis (GIO) mouse model was established, and BMSCs were isolated from the bone marrow. Compared with normal BMSCs, osteoporotic BMSCs had significantly increased adipogenesis potential and decreased osteogenesis potential. In osteoporotic BMSCs, PPARγ2 regulatory region DNA hypo-methylation, histone 3 and 4 hyper-acetylation and H3K9 hypo-di-methylation were observed. These epigenetic modifications were involved not only in PPARγ2 expression but also in osteoporotic BMSC adipogenic differentiation potential. We also found that Wnt/β-catenin signal played an important role in the establishment and maintenance of epigenetic modifications at PPARγ2 promoter in osteoporotic BMSCs. Finally, we inhibited adipogenesis and rescued osteogenesis of osteoporotic BMSCs by modulating those epigenetic modifications. Our study provides a deeper insight into the pathophysiology of osteoporosis and identifies PPARγ2 as a new target for osteoporosis therapy based on epigenetic mechanisms