43 research outputs found
Hydroelectric Power Auto with Torque Peripheral to the Wheels
The current state of the art of means of transport was affected by heat engines which predominated for the absence of viable renewable energy with small dimensions But the invention of the pump with double separate supply until the impeller has allowed the pressurized hydropower invention with recycling water which can replace thermal engines Certainly it is more cumbersome but immensely cheaper and nonpolluting From the point of view of the electro-mechanical means of transport that will use the pressurized hydropower are simplified eliminating in addition to heat engines the fuel tank the mufflers and exhaust pipes the engine cooling system the transmission shafts the exchange gears clutch differential The hydroelectricelectronic system which will be used does not need of fuels and even of heavy and expensive batteries lithium accumulators with little shipping autonomy which involve considerable disposal costs and the use of materials in the process of exhaustion The hydroelectric means of transport will cost less of the existing means of transport for the absence of many of the components mentioned above but also because the motion transmission by electric-electronic means is much more economical than the mechanical without sacrificing the safety on the road In fact the fourwheel drive of the wheels may be of series and all the wheels powered and controlled individually Also the control of the differential speed in the curves and the braking system ABS may be incorporated in the motors that turn the wheels by transmitting the driving torque to the periphery and not in the center of the wheels as in the existing vehicle
Pressurized Domestic Hydraulic System, Producer of Hydroelectric Energy
The invention of pump with dual supply until to the impeller has allowed developing different ways to produce hydroelectric energy with water recycling But those which guarantee the best performance with reduced dimensions are those which use pressurized water tanks with compressed air In fact in the case of a hydraulic system with pressurized autoclave 1 we can not use the energy of the water surface position of an open basin which produces kinetic energy in the descending pipe which feeds the pump and turbine but we can exploit the compressed air pressure that pushes the pressurized water directly in a turbine or a pump used as a turbine 2 and discharging in a reservoir at atmospheric pressure 3 In this case we exploit the pressure drop and the flow rate through the turbine while the pump with double separate supply until to the impeller immediately re-inserting the water in the pressurized tank 1 from the suction side of one of the two feeding inlets and by recycling simultaneously with the other feed the pressurized water inside the tank allows to maintain constant the water level saving the energy that would be necessary for the restoration of the pressure of the air cushion and that to win the hydrostatic pressure consuming only the energy required for water circulation within the accumulated volume of water The energy sources of this plant are the compressibility of the air and the noncompressibility of water Pairing two identical systems one for hot water and one for cold water in our homes we can produce energy for twenty-four hours a day and three hundred sixty-five days per year distributing the hot or cold water to the heating system cooling and services but without gas boilers and even solar panels in part by reducing energy production only in the pickup phase of water consumption and for heating or cooling of the apartment The energy produced by pressurized domestic hydroelectric plants will be about ten times greate
Non-Homologous end joining induced alterations in DNA methylation: A source of permanent epigenetic change
In addition to genetic mutations, epigenetic revision plays a major role in the development and progression of cancer; specifically, inappropriate DNA methylation or demethylation of CpG residues may alter the expression of genes that promote tumorigenesis. We hypothesize that DNA repair, specifically the repair of DNA double strand breaks (DSB) by Non-Homologous End Joining (NHEJ) may play a role in this process. Using a GFP reporter system inserted into the genome of HeLa cells, we are able to induce targeted DNA damage that enables the cells, after successfully undergoing NHEJ repair, to express WT GFP. These GFP+ cells were segregated into two expression classes, one with robust expression (Bright) and the other with reduced expression (Dim). Using a DNA hypomethylating drug (AzadC) we demonstrated that the different GFP expression levels was due to differential methylation statuses of CpGs in regions on either side of the break site. Deep sequencing analysis of this area in sorted Bright and Dim populations revealed a collection of different epi-alleles that display patterns of DNA methylation following repair by NHEJ. These patterns differ between Bright and Dim cells which are hypo- and hypermethylated, respectively, and between the post-repair populations and the original, uncut cells. These data suggest that NHEJ repair facilitates a rewrite of the methylation landscape in repaired genes, elucidating a potential source for the altered methylation patterns seen in cancer cells, and understanding the mechanism by which this occurs could provide new therapeutic targets for preventing this process from contributing to tumorigenesis
LSD1: more than demethylation of histone lysine residues
Lysine-specific histone demethylase 1 (LSD1) represents the first example of an identified nuclear protein with histone demethylase activity. In particular, it plays a special role in the epigenetic regulation of gene expression, as it removes methyl groups from mono- and dimethylated lysine 4 and/or lysine 9 on histone H3 (H3K4me1/2 and H3K9me1/2), behaving as a repressor or activator of gene expression, respectively. Moreover, it has been recently found to demethylate monomethylated and dimethylated lysine 20 in histone H4 and to contribute to the balance of several other methylated lysine residues in histone H3 (i.e., H3K27, H3K36, and H3K79). Furthermore, in recent years, a plethora of nonhistone proteins have been detected as targets of LSD1 activity, suggesting that this demethylase is a fundamental player in the regulation of multiple pathways triggered in several cellular processes, including cancer progression. In this review, we analyze the molecular mechanism by which LSD1 displays its dual effect on gene expression (related to the specific lysine target), placing final emphasis on the use of pharmacological inhibitors of its activity in future clinical studies to fight cancer
Therapeutic opportunities to modulate immune tolerance through the metabolism-chromatin axis
: The ability of the immune system to discriminate external stimuli from self-components - namely immune tolerance - occurs through a coordinated cascade of events involving a dense network of immune cells. Among them, CD4+CD25+ T regulatory cells are crucial to balance immune homeostasis and function. Growing evidence supports the notion that energy metabolites can dictate T cell fate and function via epigenetic modifications, which affect gene expression without altering the DNA sequence. Moreover, changes in cellular metabolism couple with activation of immune pathways and epigenetic remodeling to finely tune the balance between T cell activation and tolerance. This Review summarizes these aspects and critically evaluates novel possibilities for developing therapeutic strategies to modulate immune tolerance through metabolism via epigenetic drugs
A novel workflow for the qualitative analysis of DNA methylation data
DNA methylation is an epigenetic modification that plays a pivotal role in major biological mechanisms, such as gene regulation, genomic imprinting, and genome stability. Different combinations of methylated cytosines for a given DNA locus generate different epialleles and alterations of these latter have been associated with several pathological conditions. Existing computational methods and statistical tests relevant to DNA methylation analysis are mostly based on the comparison of average CpG sites methylation levels and they often neglect non-CG methylation. Here, we present EpiStatProfiler, an R package that allows the analysis of CpG and non-CpG based epialleles starting from bisulfite sequencing data through a collection of dedicated extraction functions and statistical tests. EpiStatProfiler is provided with a set of useful auxiliary features, such as customizable genomic ranges, strand-specific epialleles analysis, locus annotation and gene set enrichment analysis. We showcase the package functionalities on two public datasets by identifying putative relevant loci in mice harboring the Huntington's disease-causing Htt gene mutation and in Ctcf +/- mice compared to their wild-type counterparts. To our knowledge, EpiStatProfiler is the first package providing functionalities dedicated to the analysis of epialleles composition derived from any kind of bisulfite sequencing experiment
Tracing and tracking epiallele families in complex DNA populations
DNA methylation is a stable epigenetic modification, extremely polymorphic and driven by stochastic and deterministic events. Most of the current techniques used to analyse methylated sequences identify methylated cytosines (mCpGs) at a single-nucleotide level and compute the average methylation of CpGs in the population of molecules. Stable epialleles, i.e. CpG strings with the same DNA sequence containing a discrete linear succession of phased methylated/non-methylated CpGs in the same DNA molecule, cannot be identified due to the heterogeneity of the 5′–3′ ends of the molecules. Moreover, these are diluted by random unstable methylated CpGs and escape detection. We present here MethCoresProfiler, an R-based tool that provides a simple method to extract and identify combinations of methylated phased CpGs shared by all components of epiallele families in complex DNA populations. The methylated cores are stable over time, evolve by acquiring or losing new methyl sites and, ultimately, display high information content and low stochasticity. We have validated this method by identifying and tracing rare epialleles and their families in synthetic or in vivo complex cell populations derived from mouse brain areas and cells during postnatal differentiation
RNA stabilizes transcription-Dependent Chromatin Loops Induced By Nuclear Hormones
We show that transcription induced by nuclear receptors for estrogen (e2) or retinoic acid (RA) is associated with formation of chromatin loops that juxtapose the 5’ end (containing the promoter) with the enhancer and the 3′ polyA addition site of the target gene. We nd three loop con gurations which change as a function of time after induction: 1. RA or E2-induced loops which connect the 5′ end, the enhancer and the 3′ end of the gene, and are stabilized by RNA early after induction; 2. E2-independent loops whose stability does not require RNA; 3. Loops detected only by treatment of chromatin with RNAse H1 prior to hormonal induction. RNAse H1 digests RNA that occludes the relevant restriction sites, thus preventing detection of these loops. R-loops at the 5′ and 3′ ends of the RA or e2-target genes were demonstrated by immunoprecipitation with anti-DNA-RNA hybrid antibodies as well as by sensitivity to RNAse H1. The cohesin RAD21 subunit is preferentially recruited to the target sites upon RA or e2 induction of transcription. R21 binding to chromatin is eliminated by RNAse H1. We identi ed e2-induced and RNase H1-sensitive antisense RNAs located at the 5′ and 3′ ends of the e2-induced transcription unit which stabilize the loops and RAD21 binding to chromatin. This is the rst report of chromatin loops that form after gene induction that are maintained by RNA:DNA hybrids
DNA damage and Repair Modify DNA methylation and Chromatin Domain of the Targeted Locus: Mechanism of allele methylation polymorphism
We characterize the changes in chromatin structure, DNA methylation and transcription during and after homologous DNA repair (HR). We find that HR modifies the DNA methylation pattern of the repaired segment. HR also alters local histone H3 methylation as well chromatin structure by inducing DNA-chromatin loops connecting the 5' and 3' ends of the repaired gene. During a two-week period after repair, transcription-associated demethylation promoted by Base Excision Repair enzymes further modifies methylation of the repaired DNA. Subsequently, the repaired genes display stable but diverse methylation profiles. These profiles govern the levels of expression in each clone. Our data argue that DNA methylation and chromatin remodelling induced by HR may be a source of permanent variation of gene expression in somatic cells