Search

Abstract Background Skeletal Stem Cells (SSCs) are required for skeletal development, homeostasis, and repair. The perspective of their wide application in regenerative medicine approaches has supported research in this field, even though so far results in the clinic have not reached expectations, possibly due also to partial knowledge of intrinsic, potentially actionable SSC regulatory factors. Among them, the pleiotropic cytokine RANKL, with essential roles also in bone biology, is a candidate deserving deep investigation. Methods To dissect the role of the RANKL cytokine in SSC biology, we performed ex vivo characterization of SSCs and downstream progenitors (SSPCs) in mice lacking Rankl (Rankl −/− ) by means of cytofluorimetric sorting and analysis of SSC populations from different skeletal compartments, gene expression analysis, and in vitro osteogenic differentiation. In addition, we assessed the effect of the pharmacological treatment with the anti-RANKL blocking antibody Denosumab (approved for therapy in patients with pathological bone loss) on the osteogenic potential of bone marrow-derived stromal cells from human healthy subjects (hBMSCs). Results We found that, regardless of the ossification type of bone, osteochondral SSCs had a higher frequency and impaired differentiation along the osteochondrogenic lineage in Rankl −/− mice as compared to wild-type. Rankl −/− mice also had increased frequency of committed osteochondrogenic and adipogenic progenitor cells deriving from perivascular SSCs. These changes were not due to the peculiar bone phenotype of increased density caused by lack of osteoclast resorption (defined osteopetrosis); indeed, they were not found in another osteopetrotic mouse model, i.e., the oc/oc mouse, and were therefore not due to osteopetrosis per se. In addition, Rankl −/− SSCs and primary osteoblasts showed reduced mineralization capacity. Of note, hBMSCs treated in vitro with Denosumab had reduced osteogenic capacity compared to control cultures. Conclusions We provide for the first time the characterization of SSPCs from mouse models of severe recessive osteopetrosis. We demonstrate that Rankl genetic deficiency in murine SSCs and functional blockade in hBMSCs reduce their osteogenic potential. Therefore, we propose that RANKL is an important regulatory factor of SSC features with translational relevance.

IntroductionAutosomal recessive osteopetrosis (ARO) is a rare genetic disease, characterized by increased bone density due to defective osteoclast function. Most of the cases are due to TCIRG1 gene mutation, leading to severe bone phenotype and death in the first years of life. The standard therapy is the hematopoietic stem cell transplantation (HSCT), but its success is limited by several constraints. Conversely, gene therapy (GT) could minimize the immune-mediated complications of allogeneic HSCT and offer a prompt treatment to these patients.MethodsThe Tcirg1-defective oc/oc mouse model displays a short lifespan and high bone density, closely mirroring the human condition. In this work, we exploited the oc/oc neonate mice to optimize the critical steps for a successful therapy.ResultsFirst, we showed that lentiviral vector GT can revert the osteopetrotic bone phenotype, allowing long-term survival and reducing extramedullary haematopoiesis. Then, we demonstrated that plerixafor-induced mobilization can further increase the high number of HSPCs circulating in peripheral blood, facilitating the collection of adequate numbers of cells for therapeutic purposes. Finally, pre-transplant non-genotoxic conditioning allowed the stable engraftment of HSPCs, albeit at lower level than conventional total body irradiation, and led to long-term survival and correction of bone phenotype, in the absence of acute toxicity.ConclusionThese results will pave the way to the implementation of an effective GT protocol, reducing the transplant-related complication risks in the very young and severely affected ARO patients.

Heterotrophic microalgae cultivation has been suggested to reduce conventional photo-autotrophic microalgal biomass production costs. In heterotrophic cultivation, the most relevant operational costs are constituted by the supply of pure substrates used as carbon source (e.g., glucose), and the high energy request for culture aeration. In addition, suboptimal conditions of temperature and pH reduce the algal productivity, further increasing production costs. In this work, an attempt was made to define more sustainable and cost-effective strategies for the heterotrophic cultivation of Chlorellaceae and Scenedesmaceae. Several by-products from a local confectionery industry were thus screened as alternative carbon sources. Manufacturing residues from peppermint and liquorice candies production allowed to achieve comparable maximum growth rates (1.44 d-1), biomass yields (0.33 g COD·g COD-1) and biomass productivities (370 mg COD·L-1·d-1) as those achieved using glucose. A preliminary economic evaluation showed that the operational costs could be lowered of up to 85.6% by substituting glucose with the selected industrial by-products. As for fermentation conditions, high growth rates could be maintained at relatively low dissolved oxygen (DO) concentrations, and in a large range of temperature and pH values. In addition, optimal temperatures (37.0 – 37.2°C), pH values (6.8 – 7.4), and DO concentrations (> 0.5 – 1 mg O2·L-1) were identified. On the overall, the study demonstrated the possibility of achieving the reduction of operational costs for heterotrophic microalgae cultivation, while implementing circular economy principles in the framework of resource recovery during the bioremediation of organic waste.

My aim is to reconstruct the basic steps and the fundamental idea of Kant’s transcendental deduction of categories as well as Hegel’s interpretation and reframing of Kant’s idea. Hegel’s reading is crucial for two reasons: first, for fixing the basic form of the Kant­ian argument and secondly, for understanding its metaphilosophical relevance. For Hegel, philosophical proof has a specific nature, which distinguishes it from scientific proof and brings it closer to a juridical one. In this perspective the transcendental deduction, which is universally considered one of the most difficult chapters in the history of philosophy, reveals itself as the genuine clarification of specifically philosophical proof. I first present the idea of Kant’s transcendental deduction in the Critique of Pure Reason as well as its Hegelian reading in the Science of Logic and reformulation as the very method of philosophy in the Philo­sophy of Right. I show what in the Kantian argumentation constituted the basis for Hegel’s own interpretation and transformation. In so doing, I highlight a ‘red thread’ between the two ideas of the transcendental deduction. I conclude by proposing a formal account of Kant’s and Hegel’s ideas and by summing up the main metaphilosophical insights we can gain from Kant’s idea and its Hegelian interpretation.

Standard machine learning and deep learning architectures have been widely used in the field of sentiment analysis, but their performance is unsatisfactory if the input texts are short (e.g., social media posts). Specifically, the accuracy of standard machine learning methods crucially depends on the richness and completeness of the features used to represent the texts, and in the case of short messages, it is often difficult to obtain high-quality features. Conversely, methods based on deep learning can achieve better expressiveness, but these methods are computationally demanding and often suffer from over-fitting. This paper proposes a new adaptive evolutionary computational integrated learning model (AdaECELM) to overcome the problems encountered by traditional machine learning and deep learning models in sentiment analysis for short texts. AdaECELM consists of three phases: feature selection, sub classifier training, and global integration learning. First, a grid search is used for feature extraction and selection of term frequency-inverse document frequency (TF-IDF). Second, cuckoo search (CS) is introduced to optimize the combined hyperparameters in the sub-classifier support vector machine (SVM). Finally, the training set is divided into different feature subsets for sub-classifier training, and then the trained sub-classifiers are integrated and learned using the AdaBoost integrated soft voting method. Extensive experiments were conducted on six real polar sentiment analysis data sets. The results show that the AdaECELM model outperforms the traditional ML comparison methods according to evaluation metrics such as accuracy, precision, recall, and F1-score in all cases, and we report an improvement in accuracy exceeding 4.5%, the second-best competitor.

Pre-B cell leukemia factor 1 (PBX1) is a Three Aminoacid Loop Extension (TALE) homeodomain-containing transcription factor playing crucial roles in organ pattering during embryogenesis, through the formation of nuclear complexes with other TALE class and/or homeobox proteins to regulate target genes. Its contribution to the development of several organs has been elucidated mainly through the study of murine knockout models. A crucial role for human development has been recently highlighted through the discovery of different de novo pathogenic PBX1 variants in children affected by developmental defects. In the adult, PBX1 is expressed in selected tissues such as in the brain, in the gastro-intestinal and urinary systems, or in hematopoietic stem and progenitor cells, while in other organs is barely detectable. When involved in the t(1;19) chromosomal translocation it acts as an oncogene, since the resulting fusion protein drives pre-B cell leukemia, due to the induction of target genes not normally targeted by the native protein. Its aberrant expression has been associated to tumor development, progression, or therapy-resistance as in breast cancer, ovarian cancer or myeloproliferative neoplasm (MPN). On the other hand, in colorectal cancer PBX1 functions as a tumor suppressor, highlighting its context-dependent role. We here discuss differences and analogies of PBX1 roles during embryonic development and in cancer, focusing mainly on the most recent discoveries.

The integration of microalgae cultivation in anaerobic digestion (AD) plants can take advantage of relevant nutrients (ammonium and ortho-phosphate) and CO2 loads. The proposed scheme of microalgae integration in existing biogas plants aims at producing approximately 250 t·y−1 of microalgal biomass, targeting the biostimulants market that is currently under rapid expansion. A full-scale biorefinery was designed to treat 50 kt·y−1 of raw liquid digestate from AD and 0.45 kt·y−1 of CO2 from biogas upgrading, and 0.40 kt·y−1 of sugar-rich solid by-products from a local confectionery industry. An innovative three-stage cultivation process was designed, modelled, and verified, including: i) microalgae inoculation in tubular PBRs to select the desired algal strains, ii) microalgae cultivation in raceway ponds under greenhouses, and iii) heterotrophic microalgae cultivation in fermenters. A detailed economic assessment of the proposed biorefinery allowed to compute a biomass production cost of 2.8 ± 0.3 €·kg DW−1, that is compatible with current downstream process costs to produce biostimulants, suggesting that the proposed nutrient recovery route is feasible from the technical and economic perspective. Based on the case study analysis, a discussion of process, bioproducts and policy barriers that currently hinder the development of microalgae-based biorefineries is presented.

In this work, the nutrients and eutrophication problem are integrated into a nature-based solution by incorporating microalgae-based nutrient removal from wastewater and collecting the residue in an anaerobic digestion plant to produce biogas that is directly exported to an existing gas-fired power plant and closes the bioresource loop. El Burullus lake in Egypt was selected as a case study because it is rich in nutrients and suitable for the integrated system. The theoretical results were promising as for one-hectare, nutrient pollution could be reduced with a total nitrogen removal rate of 4 kg d-1, a total phosphorus removal rate of 1.1 kg d-1, and a total COD removal rate of 9.3 kg d-1. The digester volume corresponding to the biomass produced was 120 m3 per hectare of algae pond and the methane yield (Y) from anaerobic digestion was 73 m^3 d^(-1).

This work provides insights into the possibility of integrating recovered volatile fatty acids (VFAs) into biological nitrogen removal processes. VFAs are the main products of the acidogenic fermentation of waste sludge and are an effective carbon source for denitrification in activated sludge processes. The assessment of denitrification rates and the utilisation hierarchy of different VFAs are relevant to evaluating the possibility of replacing external carbon sources with the fermented liquid, FL, from acidogenic fermentation. To this scope, single VFAs, FL collected from a full-scale waste sludge fermenter, and commercial hydroalcoholic solutions have been tested with manometric lab-scale tests. Regarding single acids, acetic acid showed the highest denitrification rates, up to 4 mg N-NO3 g VSS−1 h−1, while more complex acids usually showed a lower denitrification rate. The synthetic VFA mixture and FL showed a higher denitrification rate than the sole acetate (up to 134% of the acetate denitrification rate). Mass balances across the full-scale wastewater treatment plant demonstrated the positive role of FL dosage in enhancing the denitrification process in the activated sludge treatment, with an average nitrogen removal equal to 57% and 78% without and with FL dosage, respectively. Batch manometric tests proved to be an efficient and reliable tool to assess the quality of the carbon sources as well as the activity of denitrifying bacteria in activated sludge samples.