Phase Of Regeneration Research Articles

Enhancing Educational Assessments: Score Regeneration through Post-Item Analysis with Artificial Intelligence

Over the years, the significant increase in candidates taking part in examinations and competitive exams has prompted the relevant bodies and institutions to reconsider their assessment approaches. This evolution largely stems from the growing prevalence of Artificial Intelligence (AI) and continuous technological advances. The primary aim of this research is to evaluate the effectiveness of Multiple-Choice Tests (MCTs) enhanced by AI through comprehensive item analysis followed by score regeneration focusing on the most discriminant items, aiming to strengthen assessment accuracy. The predominant adoption of MCTs has emerged, offering a practical and efficient solution for rigorously assessing a wide range of candidates. The success of this method hinges on the quality of its items. Therefore, ensuring the validity of such exams relies heavily on statistical analysis to select relevant items that are balanced in terms of difficulty and discriminatory power. Given the challenges of this analysis during test development, a new approach using score regeneration through an AI tool is proposed. This approach is based on a posterior statistical analysis of candidate performance with adjusted scores by eliminating the least discriminating items. The research sample was intentionally selected, consisting of computer science trainee teachers spread over the last three academic years. To validate this approach, a comparative study was conducted using the t-student’s test and the Spearman correlation coefficient on the grades obtained in algorithmic and programming training modules each year. The results demonstrate that incorporating this score regeneration phase considerably improves the credibility of MCTs-based assessments, providing a solid foundation for educational decision-making. The findings affirm the research objective by showing that AI-enhanced MCTs offer a reliable and valid method for large-scale candidate assessment.

Characterizing Reversible and Irreversible Degradation Effects of PEM Water Electrolyzer Stacks

Polymer electrolyte membrane water electrolyzers (PEMEL) have been identified as a key component in a decarbonized large-scale energy system, as they can produce high-purity hydrogen from renewable electricity sources for the chemical industry or energy storage. However, the long-term durability and performance of PEM electrolyzers remain a major challenge, with degradation being a critical factor that limits their lifespan and efficiency. Recent studies have focused on developing accelerated stress test (AST) protocols for PEM electrolyzers to better understand the conditions and mechanisms that lead to degradation.1, 2 Especially the reversible rise in cell potential, which in the literature is often regarded as apparent or reversible degradation, must be further investigated to find mitigation strategies for operation.3, 4 We present our research on the development of two testing protocols (static, dynamic) characterizing reversible and irreversible degradation effects for PEMEL stacks in different operation modes. Our aim is to gain a better understanding of the variance of these phenomena in general and the recovery of reversible effects across PEMEL stacks. The measurements are carried out on a commercialized Greenlight E400 test bench equipped with a 7kW 8 cell PEMEL stack (Hydrogen Innovation GmbH). The potential of all cells will be monitored during testing. The measurements include repeated electrochemical characterization protocols measuring i/E-curves, HFR and impedance spectroscopy (EIS) of the PEMEL stack and if possible, every single cell. These protocols include the introduction of low potential regeneration phases before every characterization during the test protocol to distinguish between reversible effects and the irreversible cell degradation. This was seen to be effective for potential recovery by Suermann et al. 2019 for single PEMEL cells.4 The results consist of a description of the two testing procedures and the used equipment. Due to the duration of each test protocol (3000 h) only results of the static test protocol can be presented.The contribution of the presented research is threefold. Firstly, we break down the degradation across a whole stack. Giving valuable insights regarding the distribution of cell efficiency and degradation effects. Secondly, the presented test protocols characterize and account for the reversible rise in cell/stack potential. Thirdly, the characterization of the recovery time of the cell potential across the stack will have implications for the operation of stacks to mitigate or recover these performance losses. We address both static and dynamic operation modes aiming to simulate the application of PEMEL stacks for a constant production of hydrogen used in downstream processes and the volatile operation due to a direct coupling with renewable energy sources.This publication is to be seen as presentation of first results in our ongoing research to find test protocols for short stack systems to develop operation strategies, which can be applied to large scale electrolyzer systems. Furthermore, we try to deepen the understanding of the reversible cell potential rise as well as standardize the general testing of PEMEL stacks.This work is funded by the Federal Ministry of Education and Research (BMBF) in the project “hyBit” under the grant 03SF0687E. The authors declare that the opinions expressed in this submission are their own and are based on a thorough review of existing scientific literature. Sources 1. G. Tsotridis and A. Pilenga, EU harmonized protocols for testing of low temperature water electrolysis, Publications Office of the European Union, Luxembourg (2021). 2. A. Voronova, H.-J. Kim, J. H. Jang, H.-Y. Park and B. Seo, International Journal of Energy Research, 46 (2022) 11867. 3. C. Rakousky, U. Reimer, K. Wippermann, S. Kuhri, M. Carmo, W. Lueke and D. Stolten, Journal of Power Sources, 342 (2017) 38. 4. M. Suermann, B. Bensmann and R. Hanke-Rauschenbach, Journal of The Electrochemical Society, 166 (2019) F645-F652.

Institutionalisation of public participation in China's urban regeneration from the perspective of historical institutionalism: Three-stage cases in Guangzhou

Research into public participation in urban regeneration holds a significant position in global urban research, with a considerable body of literature describing the practices of multiple stakeholders' participation in diverse institutional contexts. In the centralised dynamic context for China's urban regeneration, the institutional arrangements and practices of public participation and the evolution processes between them still remain “black boxes”. This paper aims to clarify the institutionalisation process of public participation in China's urban regeneration. Using the historical institutionalism perspective, this research adapts the institutionalisation framework proposed by Burns and Scapens (2000) to the analysis of participatory governance in China's planning context. It analyses three phases of urban regeneration in Guangzhou and provides corresponding case studies for an in-depth analysis. The findings reveal that the success of public participation in urban regeneration varies across phases, mainly due to the degree of government power sharing and the inclusion of non-governmental actors in decision-making through genuinely participative interactions. This research develops an institutionalisation analysis framework and notes that the proposed institutionalisation path only partially applies to public participation in China's urban regeneration. The institutionalisation of public participation from the institutional realm to the realm of action in China's regeneration practices departs from hysteresis, which is the opposite of synchronisation in historical institutionalism. The root cause of this inefficient institutionalisation and its separation from practice is the imbalance in the allocation of power resources. These findings provide institutionalisation insights into the interrelationships between the evolution of policy and practices of public participation.

Система мониторинга природной динамики лесного массива заповедника «Костомукшский»

The concept and current results of setting up the forest monitoring network at the Kostomukshska Strict Nature Reserve (Zapovednik) are presented. It has been demonstrated that pine forests predominate in the reserve’s forest cover (80.4 % of the forested area), followed by spruce (19.1 %) and birch (0.5 %). The ecological spectrum of the reserve’s forests comprises 7 groups of forest types, with the bilberry group prevailing (67 %) both among pine and among spruce stands. In terms of age structure, coniferous stands in the reserve are even-aged, multi-aged and all-aged, representing stages of the post-catastrophic regeneration succession and phases of subclimax and climax community cycles. Analysis of spatial patterns in the distribution of pristine and secondary forests has shown that anthropogenically altered forests are mainly situated in the western part of the reserve, at the border with Finland. The eastern part is a concentration of pristine north-taiga forests with a distinct mosaic of natural age dynamics phases. It was suggested that the forest monitoring network should be based on the landscape typological and spatial-temporal approaches taking into account the sublandscape-level structure of the reserve’s natural territorial complex and the distribution of forests in the study area by the rate of anthropogenic influence, prevalent species, forest types, and age structure types. Permanent sample plots will be established within 3 model areas (sites). For each of the 5 forest types of pine and 2 types of spruce stands, such plots should represent all age groups of even-aged stands (4 sample plots at maximum), and at least one sample plot should be allocated for each type (subtype) of the uneven-aged structure. The preliminary estimate is that, in total, there should be at least 98 permanent sample plots in the forest monitoring network of the Kostomukshskiy Zapovednik. So many units are needed to work out the algorithm for correcting the existing forest compartment characteristics given by the forest inventory in what concerns the age structure and the succession phase of stands. It is foreseen that all the factual material thus amassed will serve as the basis for modeling the scenarios of the natural dynamics of this forest massif and, perhaps, of other objects with similar structure. For citation: Raevsky B.V., Ilinov A.A., Medvedeva M.V., Rudkovskaya O.V. The Natural Dynamics Monitoring System of the Forests in the Kostomukshsky Reserve. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 6, pp. 81–101. (In Russ.). https://doi.org/10.37482/0536-1036-2023-6-81-101

Clinical substantiation of the platelet-rich plasma effectiveness in complex surgical treatment of gingival recession

Gingival recession is a non-inflammatory pathological process characterized by apical migration of the marginal gingiva below the CEJ. The use of platelet-rich plasma is one of the current technologies in the complex treatment of gingival recession. The aim of the study was to increase the effectiveness of surgical treatment of gingival recession using platelet plasma. As a result of the treatment of gingival recession I, II and III Millers classes, the coverage area of the recipient surface was 84%, 77% and 60%, accordingly; the thickness of the keratinized gingiva increased by an average of 2 times. The use of platelet plasma in the complex treatment of gingival recession optimizes the healing period in the regeneration phase, improves the microcirculation of periodontal tissues and reduces the duration of treatment by an average of three days; shows more efficiency due to less physiological shrinkage of the graft over time.

Design and performance analysis of braking system in an electric vehicle using adaptive neural networks

Research article emphasizes on the impact of braking concepts considering regenerative braking system and energy consumption aspects in electric vehicles through a new perspective. The electric vehicle system is modeled and simulated using the MATLAB/Simulink software. A dataset is developed using the virtual simulation environment created by co-simulation using the MATLAB/Simulink and the IPG Carmaker software. This dataset is also used in a neural network model based on adaptive neuro fuzzy logic and the system performance is analyzed. Parameters considered for training the neural network are the brake pedal displacement, braking change rate and the need for brake application. The highlight of this study is the focus on a front wheel driven electric vehicle, which uses a standard drive cycle input to validate the model. The significant parameters evaluated in this study include the braking effects, kinetic energy, regenerative braking torque, battery state of the charge and the motor torque. The torque generation and its intended braking force requirements based on the acceleration, deceleration and braking conditions are the notable observations. The regenerative capability of this proposed system design is also illustrated along with the surface plots based on the training dataset. Investigation and analysis reveal that, the battery state of charge could be revived throughout the drive with a steady and stable increase. Transitions of motor torques between tractive and regenerative phases are also illustrated and explained for clarity and brevity.

The response of different-aged saplings to light gradients reveals new insights into the light requirements of an endangered woody plant species, Phoebe chekiangensis

Abstract Phoebe chekiangensis is endemic to China and highly valued for art ware, furniture, and timber architecture, having a special status in Chinese history. Natural sources of P. chekiangensis are being depleted, and the species was listed as ‘VULNERABLE’ on the IUCN Red List of Threatened Species in 1998 (https://www.iucnredlist.org/) due to excessive anthropogenic deforestation and the plant’s weak self-regeneration ability. Most studies have attempted to elucidate this weak natural regeneration by culturing seedlings and community surveys, ignoring the different light requirements of seedlings at distinct ages. In this study, we examined five consecutive age groups of seedlings/saplings with current-year (seedling) and 1–4-year-olds exposed to four shading treatments (100%, 40%, 15%, and 5% of full sunlight) for 2 years, based on a randomized complete block design. Using analysis of variance and Duncan’s multiple comparison, the growth rate, photosynthetic response, photosynthetic pigments, and ultrastructure of chloroplasts were evaluated among the shading treatments. The results show that the light requirements of P. chekiangensis change during the development process. Moderate shading (40% of full sunlight) is beneficial for the early development of Phoebe seedlings, increasing height growth, photosynthetic efficiency, and photosynthetic pigment content and protecting the development of chloroplast structures. However, full exposure to sunlight is necessary for growing saplings (more than 2 years old) to meet the increased energy demands for growth and development. Overall, this study elucidates P. chekiangensis light utilization during the early regeneration phase, informing seedling cultivation activities and the development of silvicultural strategies of this endangered species.

COMMBINI: an experimentally-informed COmputational Model of Macrophage dynamics in the Bone INjury Immunoresponse.

Bone fracture healing is a well-orchestrated but complex process that involves numerous regulations at different scales. This complexity becomes particularly evident during the inflammatory stage, as immune cells invade the healing region and trigger a cascade of signals to promote a favorable regenerative environment. Thus, the emergence of criticalities during this stage might hinder the rest of the process. Therefore, the investigation of the many interactions that regulate the inflammation has a primary importance on the exploration of the overall healing progression. In this context, an in silico model named COMMBINI (COmputational Model of Macrophage dynamics in the Bone INjury Immunoresponse) has been developed to investigate the mechano-biological interactions during the early inflammatory stage at the tissue, cellular and molecular levels. An agent-based model is employed to simulate the behavior of immune cells, inflammatory cytokines and fracture debris as well as their reciprocal multiscale biological interactions during the development of the early inflammation (up to 5 days post-injury). The strength of the computational approach is the capacity of the in silico model to simulate the overall healing process by taking into account the numerous hidden events that contribute to its success. To calibrate the model, we present an in silico immunofluorescence method that enables a direct comparison at the cellular level between the model output and experimental immunofluorescent images. The combination of sensitivity analysis and a Genetic Algorithm allows dynamic cooperation between these techniques, enabling faster identification of the most accurate parameter values, reducing the disparity between computer simulation and histological data. The sensitivity analysis showed a higher sensibility of the computer model to the macrophage recruitment ratio during the early inflammation and to proliferation in the late stage. Furthermore, the Genetic Algorithm highlighted an underestimation of macrophage proliferation by in vitro experiments. Further experiments were conducted using another externally fixated murine model, providing an independent validation dataset. The validated COMMBINI platform serves as a novel tool to deepen the understanding of the intricacies of the early bone regeneration phases. COMMBINI aims to contribute to designing novel treatment strategies in both the biological and mechanical domains.

Proenkephalin-A secreted by renal proximal tubules functions as a brake in kidney regeneration

Organ regeneration necessitates precise coordination of accelerators and brakes to restore organ function. However, the mechanisms underlying this intricate molecular crosstalk remain elusive. In this study, the level of proenkephalin-A (PENK-A), expressed by renal proximal tubular epithelial cells, decreases significantly with the loss of renal proximal tubules and increased at the termination phase of zebrafish kidney regeneration. Notably, this change contrasts with the role of hydrogen peroxide (H2O2), which acts as an accelerator in kidney regeneration. Through experiments with penka mutants and pharmaceutical treatments, we demonstrate that PENK-A inhibits H2O2 production in a dose-dependent manner, suggesting its involvement in regulating the rate and termination of regeneration. Furthermore, H2O2 influences the expression of tcf21, a vital factor in the formation of renal progenitor cell aggregates, by remodeling H3K4me3 in renal cells. Overall, our findings highlight the regulatory role of PENK-A as a brake in kidney regeneration.

The Dynamic Landscapes of Circular RNAs in Axolotl, a Regenerative Medicine Model, with Implications for Early Phase of Limb Regeneration.

Circular RNAs (circRNAs) are of relevance to regenerative medicine and play crucial roles in post-transcriptional and translational regulation of biological processes. circRNAs are a class of RNA molecules that are formed through a unique splicing process, resulting in a covalently closed-loop structure. Recent advancements in RNA sequencing technologies and specialized computational tools have facilitated the identification and functional characterization of circRNAs. These molecules are known to exhibit stability, developmental regulation, and specific expression patterns in different tissues and cell types across various organisms. However, our understanding of circRNA expression and putative function in model organisms for regeneration is limited. In this context, this study reports, for the first time, on the repertoire of circRNAs in axolotl, a widely used model organism for regeneration. We generated RNA-seq data from intact limb, wound, and blastema tissues of axolotl during limb regeneration. The analysis revealed the presence of 35,956 putative axolotl circRNAs, among which 5331 unique circRNAs exhibited orthology with human circRNAs. In silico data analysis underlined the potential roles of axolotl circRNAs in cell cycle, cell death, and cell senescence-related pathways during limb regeneration, suggesting the participation of circRNAs in regulation of diverse functions pertinent to regenerative medicine. These new observations help advance our understanding of the dynamic landscape of axolotl circRNAs, and by extension, inform future regenerative medicine research and innovation that harness this model organism.

Histological and Immunohistochemical Characterization of Osteoimmunological Processes in Scaffold-Guided Bone Regeneration in an Ovine Large Segmental Defect Model.

Large-volume bone defect regeneration is complex and demands time to complete. Several regeneration phases with unique characteristics, including immune responses, follow, overlap, and interdepend on each other and, if successful, lead to the regeneration of the organ bone's form and function. However, during traumatic, infectious, or neoplastic clinical cases, the intrinsic bone regeneration capacity may exceed, and surgical intervention is indicated. Scaffold-guided bone regeneration (SGBR) has recently shown efficacy in preclinical and clinical studies. To investigate different SGBR strategies over periods of up to three years, we have established a well-characterized ovine large segmental tibial bone defect model, for which we have developed and optimized immunohistochemistry (IHC) protocols. We present an overview of the immunohistochemical characterization of different experimental groups, in which all ovine segmental defects were treated with a bone grafting technique combined with an additively manufactured medical-grade polycaprolactone/tricalcium phosphate (mPCL-TCP) scaffold. The qualitative dataset was based on osteoimmunological findings gained from IHC analyses of over 350 sheep surgeries over the past two decades. Our systematic and standardized IHC protocols enabled us to gain further insight into the complex and long-drawn-out bone regeneration processes, which ultimately proved to be a critical element for successful translational research.

Role of LCN2 in a murine model of hindlimb ischemia and in peripheral artery disease patients, and its potential regulation by miR-138-5P

Background and aimsPeripheral arterial disease (PAD) is a leading cause of morbimortality worldwide. Lipocalin-2 (LCN2) has been associated with higher risk of amputation or mortality in PAD and might be involved in muscle regeneration. Our aim is to unravel the role of LCN2 in skeletal muscle repair and PAD. Methods and resultsWT and Lcn2−/− mice underwent hindlimb ischemia. Blood and crural muscles were analyzed at the inflammatory and regenerative phases. At day 2, Lcn2−/− male mice, but not females, showed increased blood and soleus muscle neutrophils, and elevated circulating pro-inflammatory monocytes (p < 0.05), while locally, total infiltrating macrophages were reduced (p < 0.05). Moreover, Lcn2−/− soleus displayed an elevation of Cxcl1 (p < 0.001), and Cxcr2 (p < 0.01 in males), and a decrease in Ccl5 (p < 0.05). At day 15, Lcn2 deficiency delayed muscle recovery, with higher density of regenerating myocytes (p < 0.04) and arterioles (αSMA+, p < 0.025). Reverse target prediction analysis identified miR-138-5p as a potential regulator of LCN2, showing an inverse correlation with Lcn2 mRNA in skeletal muscles (rho = -0.58, p < 0.01). In vitro, miR-138-5p mimic reduced Lcn2 expression and luciferase activity in murine macrophages (p < 0.05). Finally, in human serum miR-138-5p was inversely correlated with LCN2 (p ≤ 0.001 adjusted, n = 318), and associated with PAD (Odds ratio 0.634, p = 0.02, adjusted, PAD n = 264, control n = 54). ConclusionsThis study suggests a possible dual role of LCN2 in acute and chronic conditions, with a probable role in restraining inflammation early after skeletal muscle ischemia, while being associated with vascular damage in PAD, and identifies miR-138-5p as one potential post-transcriptional regulator of LCN2.

Serum biochemical indicators in rats of different ages after replacing femoral metaphysis defects with allogeneic bone implants saturated with mesenchymal stem cells

The aim of the study: to evaluate the course of metabolic processes after replacing femoral metaphysis defects with allogeneic bone implants saturated with allogeneic mesenchymal stem cells (MSCs) based on the analysis of serum biochemical indicators of connective tissue metabolism in laboratory rats. Material and methods. A critical-sized transcortical femoral defect model in the femur metaphysis of white rats was used. Blood serum concentrations of glycoproteins, total chondroitin sulfates, total protein and calcium, alkaline and acid phosphatase activity were measured. Results. On the 28th day, in 3-month-old animals with MSC, in comparison with the data of rats without MSC, clear signs of connective tissue formation and bone resorption activity were observed, as evidenced by an increase in serum chondroitin sulfates and acid phosphatase activity. On the 90th day, this group of rats under the influence of MSCs showed signs of decreased bone tissue formation with lower serum activity of alkaline phosphatase. In 3-month-old rats with MSC, signs of the inflammatory process chronization with higher serum concentrations of glycoproteins were detected on the 90th day of the experiment in comparison with data from animals without MSC. In 12-month-old rats with MSCs, signs of bone resorption were documented on the 14th day, which were manifested by a higher serum activity of acid phosphatase with less formation of connective tissue and lower concentrations of chondroitin sulfates. On the 28th day, the effect of MSCs in 12-month-old animals was manifested in the form of a slowdown in bone formation with a decrease in alkaline phosphatase activity. On the 90th day, the connective tissue formation was activated with higher concentrations of chondroitin sulfates in these animals. Conclusions. The studied biochemical indicators in 3-month-old animals showed greater lability. The regeneration phases were faster in 3-month-old animals as well as in animals with alloimplants without MSCs. Injections of allogeneic MSCs together with an allograft immediately after a bone damage, regardless of age, caused signs of bone formation slowing and excessive formation of connective tissue, therefore, the combination of allogeneic MSCs with an allogeneic bone implant is not advisable to use in fresh fractures.

The role of predictive and prognostic values of inflammatory markers in acute pancreatitis: a narrative review

Pancreatitis is an inflammatory condition affecting the pancreas and is classified into 2 types, acute and chronic, which can manifest in various forms. This review article summarizes the role of predictive and prognostic values of inflammatory markers in the pathogenesis of acute pancreatitis, mainly focused on preclinical and clinical studies. It includes serum amyloid A (SAA), monocyte chemotactic protein-1 (MCP-1), erythrocyte sedimentation rate (ESR), interleukin-6 (IL-6), C-reactive protein (CRP), IL-10, myeloperoxidase, pentraxin 3, and plasminogen activator inhibitor 1. SAA3 plays a crucial role in developing acute pancreatitis by triggering a receptor-interacting protein 3–dependent necroptosis pathway in acinar cells. Targeting SAA3 could be a potential strategy for treating acute pancreatitis. The recruitment of monocytes/macrophages and the activation of the systemic MCP-1 signaling pathway play a role in the progression of pancreatitis, and blocking MCP-1 may have a suppressive effect on the development of pancreatic fibrosis. The ESR can predict severe acute pancreatitis with slightly lower accuracy than CRP. When ESR and CRP levels are combined at 24 hours, they predict severe acute pancreatitis accurately. IL-6 plays a crucial role in activating the Janus kinase/signal transducers and activators of the transcription pathway, exacerbating pancreatitis and contributing to the initiation and progression of pancreatic cancer. Endogenous IL-10 plays a crucial role in controlling the regenerative phase and limiting the severity of fibrosis and glandular atrophy induced by repeated episodes of acute pancreatitis in mice. The predictive and diagnostic roles of these inflammatory factors in pancreatitis were introduced in detail in this review.

Middle-aged forests in the Eastern U.S. have significant climate mitigation potential

Middle-aged forests in the Eastern U.S. are broadly defined to consist of forests between the regeneration phase following harvest or disturbance, and an older phase with forests composed of large trees, complex structure, and increasing natural mortality. Study objectives were to develop new carbon accumulation curves based on recent inventory data that represent the actual growth rates of forests as they advance beyond middle age; quantify the projected carbon sink from reducing or increasing harvest of middle-aged forests; and disseminate credible estimates of future carbon stocks in ecosystems and harvested wood products to support policies designed to enhance the role of forests in removing carbon dioxide from the atmosphere and storing it securely. We found that middle-aged Eastern U.S. forests could continue to accumulate carbon for many decades or several centuries in the absence of harvesting, with relatively low risk of natural disturbances. Compared with a recent study that estimated a potential increase in biomass of only 22%, and some analyses that anticipate significant increases in risks from natural disturbances, our results indicate a potential increase of about 100% over current biomass stocks by 2100. Temperate Continental forests have greater potential to increase carbon stock over longer time periods than Subtropical Humid forests. Results from scenario analyses showed that in the near term of 20–40 years, reducing harvest will yield the greatest reduction in net greenhouse gas emissions compared with business as usual. Under an extreme “no-harvest” scenario, C sequestration could increase by about 20 TgC yr−1 in Temperate Continental forests by 2050, and by about 30 TgC yr−1 in Subtropical Humid forests over the same time period. In contrast, a scenario of tripling harvest would increase C emissions by 30 and 60 TgC yr−1 in the Temperate Continental and Subtropical Humid ecozones by 2050, respectively. In the longer term of 80 or so years, all scenarios and “business as usual” converge toward similar impacts on greenhouse gas emissions, nearing neutrality in the Subtropical Humid ecozone but separated by about 30 TgC yr−1 in the Temperate Continental ecozone. Our estimated annual emission reduction from stopping harvest over the 73 million ha of middle-aged forests amounts to 117 Mg CO2 per year in 2050, equivalent to about 7% of the emissions from using fossil energy in the two ecozones. Increasing harvest would have the opposite effect of increasing emissions by a similar magnitude in 2050. How middle-aged forests in the Eastern U.S. are managed can clearly affect their contribution to achieving net-zero GHG emissions by 2050 and beyond.

The most effective techniques of industrial purification processes: a technical review

This paper reviews various separation techniques used in purification processes to remove pollutants like carbon dioxide and hydrogen sulfide from petroleum products. The most effective techniques include absorption, adsorption, cryogenic distillation, chemical looping combustion, and membrane separation. The study reviews over 100 published studies to assess their characteristics, benefits, and drawbacks. The choice of separation technology depends on ideal conditions, cost, efficiency, and energy required in the regeneration phase.

Functional and molecular profiling of hematopoietic stem cells during regeneration

Hematopoietic stem cells (HSCs) enable hematopoietic stem cell transplantation (HCT) through their ability to replenish the entire blood system. Proliferation of HSCs is linked to decreased reconstitution potential, and a precise regulation of actively dividing HSCs is thus essential to ensure long-term functionality. This regulation becomes important in the transplantation setting where HSCs undergo proliferation followed by a gradual transition to quiescence and homeostasis. While mouse HSCs have been well studied during homeostatic conditions, the mechanisms regulating HSC activation during stress remain unclear. Here, we analyzed the different phases of regeneration following transplantation. We isolated bone marrow from mice at eight time points after transplantation and examined the reconstitution dynamics and transcriptional profiles of stem and progenitor populations. We found that regenerating HSCs initially produced rapidly expanding progenitors and displayed distinct changes in fatty acid metabolism and glycolysis. Moreover, we observed molecular changes in cell cycle, MYC and mTOR signaling in both HSCs and the progenitor subsets. We used a decay rate model to fit the temporal transcription profiles of regenerating HSCs and identified genes with progressively decreased or increased expression after transplantation. These genes overlapped to a large extent with published gene sets associated with key aspects of HSC function demonstrating the potential of this data set as a resource for identification of novel HSC regulators. Taken together, our study provides a detailed functional and molecular characterization of HSCs at different phases of regeneration and identifies a gene set associated with the transition from proliferation to quiescence.

Expression profiles of lncRNAs, miRNAs, and mRNAs during the proliferative phase of liver regeneration in mice with liver fibrosis

The role of lncRNAs in the regeneration of fibrotic liver is unclear. To address this issue, we established a 70% hepatectomy model of liver fibrosis in mice, used high-throughput sequencing technology to obtain the expression profiles of lncRNAs, miRNAs, and mRNAs, and constructed a lncRNA–miRNA–mRNA regulatory network. A total of 1329 lncRNAs, 167 miRNAs, and 6458 mRNAs were differentially expressed. On this basis, a lncRNA–miRNA–mRNA ceRNA regulatory network consisting of 38 DE lncRNAs, 24 DE miRNAs, and 299 DE mRNAs was constructed, and a transcription factor (TF) – mRNA regulatory network composed of 20 TFs and 98 DE mRNAs was built. Through the protein network analysis, a core protein interaction network composed of 20 hub genes was derived. Furthermore, Xist/miR-144-3p/Cdc14b and Snhg3/miR-365-3p/Map3k14 axes in the ceRNA regulatory network were verified by Real-Time quantitative PCR. Therefore, we concluded that these new insights may further our understanding of liver regeneration.

Traditional Chinese Medicine for Topical Treatment of Skeletal Muscle Injury.

Muscle injuries are common musculoskeletal problems, but the pharmaceutical agent for muscle repair and healing is insufficient. Traditional Chinese Medicine (TCM) frequently uses topical treatments to treat muscle injuries, although scientific evidence supporting their efficacy is scarce. In this study, an in vitro assay was used to test the cytotoxicity of a topical TCM formula containing Carthami Flos, Dipsaci Radix, and Rhei Rhizoma (CDR). Then, a muscle contusion rat model was developed to investigate the in vivo effect and basic mechanisms underlying CDR on muscle regeneration. The in vitro assay illustrated that CDR was non-cytotoxic to immortalized rat myoblast culture and increased cell viability. Histological results demonstrated that the CDR treatment facilitated muscle repair by increasing the number of new muscle fibers and promoting muscle integrity. The CDR treatment also upregulated the expression of Pax7, MyoD and myogenin, as evidenced by an immunohistochemical study. A gene expression analysis indicated that the CDR treatment accelerated the regeneration and remodeling phases during muscle repair. This study demonstrated that topical CDR treatment was effective at facilitating muscle injury repair.

Hepatocytes reprogram liver macrophages involving control of TGF-β activation, influencing liver regeneration and injury.

Macrophages play an important role in maintaining liver homeostasis and regeneration. However, it is not clear to what extent the different macrophage populations of the liver differ in terms of their activation state and which other liver cell populations may play a role in regulating the same. Reverse transcription PCR, flow cytometry, transcriptome, proteome, secretome, single cell analysis, and immunohistochemical methods were used to study changes in gene expression as well as the activation state of macrophages in vitro and in vivo under homeostatic conditions and after partial hepatectomy. We show that F4/80+/CD11bhi/CD14hi macrophages of the liver are recruited in a C-C motif chemokine receptor (CCR2)-dependent manner and exhibit an activation state that differs substantially from that of the other liver macrophage populations, which can be distinguished on the basis of CD11b and CD14 expressions. Thereby, primary hepatocytes are capable of creating an environment in vitro that elicits the same specific activation state in bone marrow-derived macrophages as observed in F4/80+/CD11bhi/CD14hi liver macrophages in vivo. Subsequent analyses, including studies in mice with a myeloid cell-specific deletion of the TGF-β type II receptor, suggest that the availability of activated TGF-β and its downregulation by a hepatocyte-conditioned milieu are critical. Reduction of TGF-βRII-mediated signal transduction in myeloid cells leads to upregulation of IL-6, IL-10, and SIGLEC1 expression, a hallmark of the activation state of F4/80+/CD11bhi/CD14hi macrophages, and enhances liver regeneration. The availability of activated TGF-β determines the activation state of specific macrophage populations in the liver, and the observed rapid transient activation of TGF-β may represent an important regulatory mechanism in the early phase of liver regeneration in this context.