The Growing demands for humidity detection in commercial and industrial applications led to the rapid development of humidity sensors based on different techniques. Surface acoustic wave (SAW) technology is one of these methods that has been found to provide a powerful platform for humidity sensing owing to its intrinsic features, including small size, high sensitivity, and simple operational mechanism. Similar to other techniques, the principle of humidity sensing in SAW devices is also realized by an overlaid sensitive film, which serves as the core element whose interaction with water molecules is responsible for overall performance. Therefore, most researchers are focused on exploring different sensing materials to achieve optimum performance characteristics. This article reviews sensing materials used to develop SAW humidity sensors and their responses based on theoretical aspects and experimental outcomes. Herein the influence of overlaid sensing film on the performance parameters of the SAW device, such as quality factor, signal amplitude, insertion loss, etc., is also highlighted. Lastly, a recommendation to minimize the significant change in device characteristics is presented, which we believe will be a good step for the future development of SAW humidity sensors. Humidity is an important environmental variable that plays a decisive role in our daily lives. In addition to human comfort, its detection and control are necessary for various manufacturing and storage environments to achieve optimum quality in production ,2,3,4. FTo fulfill humidity detection demands, great efforts have been made to develop humidity sensors based on different operational mechanisms. According to the sensing techniques, these sensors are typically categorized as capacitive ,6, resisFor practical implementation, the humidity sensor must possess satisfactory traits, including high sensitivity, wide detection range, low hysteresis, good linearity, good repeatability, quick response, and short recovery time. Additionally, the factors such as compact size, low power consumption, low cost, and compatibility with fabrication processes pave the way to make the sensor design an optimal choice for practical applications. Acoustic sensors have already been found to possess these inherent characteristics.Among different types of acoustic wave devices, Surface acoustic wave (SAW) devices have captured wide attention owing to their simple detection mechanism, easy integration, high sensitivity, good stability, small size, low cost, high accuracy, planar structure, and capability to operate in wireless mode ,20,21. TThe overlaid sensing film is the main determining factor to attain maximum effectiveness of the SAW humidity sensor. Therefore the researchers are mainly concentrated on exploring different sensing materials to optimize the parameter of interest. This article reviews the SAW humidity sensors developed in nearly three decades. Firstly the basic mechanism is elaborated, followed by a detailed review of humidity-sensitive materials. Herein, data on device design, sensing materials, and performance characteristics of various existing SAW humidity sensors are summarized in tables. Moreover, the influence of overlaid sensing materials on the characteristics of SAW devices is addressed in this article. Lastly, a recommendation is presented for the future development of SAW humidity sensors.The operation of humidity detection is realized by a sensing film overlaid on the surface of the SAW device. Any perturbation on the surface due to the absorption/desorption of water molecules affects the intrinsic parameters  of the sensing film, which alters the wave characteristics. The variation in propagating acoustic wave velocity ∆vh is the sensing film thickness, Here, In Equation (1), the first term represents the variation in propagating wave velocity caused by the mass loading effect, i.e., mass density change due to the interaction of vapor molecules within the sensing film. The second term characterizes the alteration in wave velocity due to elastic loading, i.e., the modulus change. The last term illustrates the variation in wave velocity by the acoustoelectric effect, the change in electrical properties such as conductivity and permittivity. All these changes in velocity can be monitored in terms of frequency or phase shift. The algebraic signs in Equation (1) illustrate that the velocity shifts positively with elastic loading and negatively with mass and electric loading. The effect of elastic loading on the sensor response is mostly neglected for semiconducting metal oxides, ceramics, nanostructured and carbon-based materials, as the alteration in mechanical properties due to the vapor molecules absorption is negligible for these sensing materials. Therefore, the mass loading effect is mainly considered the dominant mechanism for SAW humidity sensors. However, in earlier studies, some researchers had observed a significant effect of elastic loading, particularly for viscoelastic polymer films ,29. FurtIn most of the polymer-based SAW humidity sensors, the elastic effect contributes in the same direction as the mass loading effect, i.e., the decrease in velocity (negative frequency shift), mainly due to the reduction in the modulus ,31,32, kThe sensing material coated over the surface of the SAW device is an integral part of humidity detection, which has the sensitivity to grab water molecules and give rise to sensor response based on operational mechanisms . For implementation, sensing material is required to meet a variety of specifications such as strong adhesion with the substrate, good ability to absorb water vapors, long-term repeatability, lengthy operational lifetime, repeatable, quick, and reversible interaction with the water molecules ,36. TherPolymers have become one of the most extensively used humidity-sensitive materials for over 30 years. They have gained particular attention as humidity sensing layers for SAW devices owing to their high response to water molecules, room temperature operation, low cost, and simple coating techniques. Up to present, polyimide (PI), poly (PVA), polyXIO, poly(N-vinylpyrrolidone)(PVNP), polyaniline (PANI), conjugated polymers, poly(p-diethynylbenzene) (PDEB), sodium polysulfonesulfonate (NaSPF), polyvinyl pyrrolidone (PVP) and sulfonated tetrafluorethylene copolymer(Nafion) are reported as humidity sensing membranes in SAW devices ,49,50,51Li et al.  investigIn addition to exploring polymers as humidity-sensitive materials, some researchers have presented the possibilities of improving the performance characteristics by altering the physical parameters of the sensing layer, such as thickness, densities, and mechanical adhesion ,54,55. IApart from physical parameters, the modification in the chemical properties of the sensing film can also aid in improving the sensing characteristics. In , the pol® film deposited with two different techniques, i.e., thermal evaporation and electrospraying. The film deposited by the vacuum evaporation method agglomerated into bubbles, while the electrospray-deposited film was uniform. Moreover, the electrospray Nafion® film showed lower sensitivity and detection limit but quick response time compared to thermal evaporated Nafion® film. Apart from deposition techniques, the conditions and parameters of the deposition methods also affect the humidity response of the sensor. Li et al. [Furthermore, selecting the proper coating technique is another essential factor for optimizing performance characteristics. JASEK et al.  charactei et al.  examinedi et al. . The PVPTo gain the maximum effectiveness of the humidity sensor, it is of utmost importance to carefully select various factors such as thickness, density, physical and chemical properties of sensing film, deposition technique, and their condition and parameters.3O4, CuO, TiO2, and SnO2 have been explored as the humidity sensing films for SAW devices. Among these, ZnO is versatile and one of the most extensively investigated metal oxides. The nanocrystalline ZnO [2), Al2O3, etc., are also used as humidity-sensing membranes due to their porous nature, which is advantageous to provide a large surface area for water molecules absorption. Tang et al. [3O4, CuO, TiO2) and SiO2 films coated on quartz SAW resonators. They obtained much higher responses with sol-gel SiO2 films and observed the increased response with the increase in SiO2 film thicknesses, as shown in 2 film, which facilitates the absorption of water molecules due to the large surface area. On the contrary, the metal oxide films were smooth, dense, and less porous, as shown in SEM and AFM images in 2O3) is another porous ceramic material utilized as the humidity-sensing membrane for SAW devices [Polymer sensing films show good sensing characteristics at room temperature, but their stability and repeatability are adversely affected in different environmental conditions, especially at higher temperatures. To overcome stability issues, metal oxides are utilized as an alternative due to their high thermal stability. Metal oxides such as ZnO, Coline ZnO ,38,60, Gline ZnO , and difline ZnO ,63 are e devices ,65.In recent years, the improved sensitivity based on large surface area escalated the development of nanostructured coatings as the humidity sensing material for SAW sensors. Till now, a variety of nanostructures has been synthesized, including nanofibers ,66,67, n2) and applied it in respiration monitoring. High sensitivity was obtained by the synergetic effect of large diffusion/viscoelastic/mass loading effects with the arrangement of 3DAG/PVA/SiO2 layered structure, respectively.Likewise, owing to the large surface-to-volume ratio and the presence of hydrophilic functional groups, graphene oxide (GO) has become fascinating material for developing humidity sensors. Graphene oxide is a carbon-based material with oxygen-containing, i.e., carboxyl groups, which are hydrophilic functional groups that provide the feasibility of water molecules absorption. Balashov et al.  comparedGraphene-based sensing materials provide good sensitivity, but surface contamination, long-term drift, poor reproducibility, environmental pollution, and explosion hazards are some of their big disadvantages. Each kind of sensing material has advantages and disadvantages. 3 SAW delay line. Similarly, Su et al. [2 for respiration monitoring, as shown in 2) based SAW humidity sensor was found to detect the different breath levels, i.e., normal, deep, fast, and rapid. In addition, the same humidity sensor was capable of detecting the noncontact motion of fingers due to the generation of the sharp gradient field of humidity around the fingertip. These outcomes suggest the applicability of SAW humidity sensors in different applications. Moreover, these works indicate that the SAW humidity sensors with high sensitivity, fast response-recovery time, good repeatability, and stability are appropriate for respiratory monitoring and human activity detection.The main traits of humidity sensors are high sensitivity, low hysteresis, fast response time, quick recovery time, stability, durability, linearity, and wide sensing range. However, the conditions for humidity detection depend on the specific application. Breath monitoring and skin humidity detection are among the main applications of humidity sensors for human healthcare detection. Some researchers have successfully implemented SAW humidity sensors for respiration monitoring and noncontact detection of finger motion ,69,73,78u et al.  develope11) of about 15.44 dB with the SiO2 film coated on the surface of the SAW resonator, as shown in 2 film coated on the entire SAW device, and the loss was further increased with the deposition of PVA and graphene/PVA on the delay path of the SAW device, as shown in The overlaid sensing film works as the core element whose existence predominantly characterizes the humidity sensing of the SAW device. The deposition of any kind of sensing membrane permanently changes the device parameters such as resonant frequency, quality factor, signal amplitude, etc. Yan et al.  observed2/GO-based humidity sensors, as shown in 2-based SAW humidity sensor in [The decrease in quality factor and loss in magnitude further increases with the absorption of water molecules due to the change in mass loading of sensing film. In , with thensor in . Buvailoensor in  comparedensor in ,61,68,69Moreover, the parameters such as thickness, density, viscosity, etc., of the sensing film also influence the characteristics of the SAW device. Mostly the thicker films are utilized to obtain high sensitivity, which increases the mass loading, affecting the device characteristics, i.e., reducing the amplitude of the resonant peak and broader bandwidth . It shouThe significant change in device characteristics is mostly observed for polymer films and thicker coatings. The moderate loss can be acceptable as it originates from the change in mass loading on the SAW device, but the significant loss limits the practical implementation of the sensor. Therefore it is crucial to consider both the sensing characteristics and the performance parameters of the SAW device. There exist few studies that have addressed this issue. In  small-si2, etc., causes a significant change in the SAW device characteristics. To the best of our knowledge, the existing humidity sensors are based on traditional SAW device structures. According to [2 films at different areas of the two port SAW resonator structure consisting of three IDTs as illustrated in As mentioned previously, the deposition of some sensing materials, i.e., polymers, SiOrding to , the deprding to  investigrding to  analyzedTaking these findings as a foundation, our recommendation for the future development of humidity sensors is to modify the conventional SAW device and deposit the sensing film on the optimal regions of the modified design. This can be carried out by changing the design parameters and configuration of the SAW device so that the wave energy concentrate at the required regions of the device. As discussed before, the reflector-coated SAW sensor provides better device characteristics but low sensitivity, as the wave energy is concentrated toward IDTs. Our idea is to confine a part of the wave at the reflectors by delaying the wave energy and this can be conducted with the variation in the design parameters of the SAW device. So, the deposition of sensing film only on the reflectors can result in improved sensitivity, reduce the mass loading, and also aid in minimizing the significant loss of device characteristics that originate from the large mass loading of sensing film on the entire surface of the SAW device.This article summarizes the research on SAW humidity sensors. SAW devices are effectively utilized for humidity detection due to their tremendous features. Current studies are more focused on exploring new sensing materials to get the optimal performance of humidity sensors. Polymers, metal oxides, ceramics, and nanostructured and carbon-based materials are most commonly used as humidity-sensing films for SAW devices. Each of these materials has its advantages and disadvantages. A huge number of polymer-based humidity sensors with good performance characteristics were presented. However, the stability and repeatability of these sensors are adversely affected at high temperatures, which is one of the most sounded shortcomings. Contrarily, metal oxides are found as a good alternative due to their stability in different environmental conditions. Furthermore, ceramics, nanostructures, and carbon-based materials have captured particular attention owing to their porous and large surface areas, which provide the facility of vapor molecules absorption within sensing film, resulting in enhanced sensing characteristics. The overlaid sensing layer is the core element of humidity sensors, as the response highly depends on its interaction with absorbed water molecules. Hence, most of the current studies focus on exploring and altering sensing materials to enhance sensing characteristics such as sensitivity, detection range, linearity, hysteresis, response, and recovery time. As highlighted in this review, the deposition of some sensing materials causes a significant deterioration in the performance parameter of the SAW device, i.e., signal amplitude, bandwidth, insertion loss, Q factor, etc. This loss in device characteristics becomes worst with the absorption of water molecules, especially at high humidity levels, due to large mass loading. Therefore, despite exhibiting good sensing characteristics, such sensors cannot be implemented, as a narrow bandwidth, high-quality factor, and low loss are preferred for practical applications. It is necessary to consider the significance of device characteristics while optimizing the sensing characteristics to make the sensor suitable for practical applications. Few studies addressed this issue and attempted to overcome it by small mass loading effect and deposition of sensing film over the specific regions of the SAW device. Taking these works as a foundation, our recommendation is to modify the traditional SAW device  and deposit the sensing film over optimum regions of the modified design instead of covering the whole area of the traditional device. This can be a good step in the future development of SAW-based humidity sensors.


Secondary electron emission (SEE) is a fundamental phenomenon of particle/surface interaction, and the multipactor effect induced by SEE can result in disastrous impacts on the performance of microwave devices. To suppress the SEE-induced multipactor, an Ni (111) surface covered with a monolayer of graphene was proposed and studied theoretically via the density functional theory (DFT) method. The calculation results indicated that redistribution of the electron density at the graphene/Ni (111) interface led to variations in the work function and the probability of SEE. To validate the theoretical results, experiments were performed to analyze secondary electron yield (SEY). The measurements showed a significant decrease in the SEY on an Ni (111) surface covered with a monolayer of graphene, accompanied by a decrease in the work function, which is consistent with the statistical evidence of a strong correlation between the work function and SEY of metals. A discussion was given on explaining the experimental phenomenon using theoretical calculation results, where the empty orbitals lead to an electron trapping effect, thereby reducing SEY. Secondary electron emission (SEE) under electron bombardment is a very important effect of electron solid interactions, and plays an important role in many fields of applied physics such as magnetron sputtering, plasma physics, spacecraft potential, gas discharge, scanning electron microscope, etc. ,3,4,5,6.To date, many investigations have been conducted to reduce the SEY to suppress multipactor effects. Mature techniques for low SEY mainly include surface roughening ,13,14,15In addition, as early as 1950, Baroody  pointed Therefore, the aim of this work was to investigate the characters of the graphene/Ni (111) interface through theoretical calculations, and to design a feasible solution of low SEY based on this which could withstand the experimental verification. The greater expectation was to further obtain the underlying mechanisms and a practical law for seeking low SEY. Specifically, we were interested in how the calculated electronic properties affect the work function value and how this effect reflected on the SEY. All DFT calculations in this work were performed using Vienna Ab-initio Simulation Package (VASP) within the generalized gradient approximation (GGA) ,39 for tk-point mesh of 15 × 15 × 1. The cut-off energy for the plane wave basis was 1.3 times the maximum energy value based on experiential rules and so it was set to 520 eV, and the energy convergence criterion was set to 10−10 Hartree. Ground state calculations and optimization of the studied systems were performed using the pseudopotentials of the Perdew–Burke–Ernzerhof functional with the projector augmented wave (PAW-PBE). In the structural relaxation, one layer of atoms at the bottom of the substrate metal was fixed to simulate the bulk material, whereas the three layers on the surface were released. Relaxation ended when the maximum value of the interatomic force was less than 0.02 eV/Å. Furthermore, the work function φ calculated in this study was obtained by self-consistent calculations, as given by:z-axis averaging the electrostatic potential output LOCPOT, and The length of the vacuum gap was set to 16.57 Å, and the initial distance between surface nickel atoms and carbon atoms was 3 Å. With the convergence test, the first Brillouin zone was sampled using a Experiments were designed to verify the theoretical calculations. In the experimental preparation, single-crystal Ni (111) (cubic phase) samples were machined into dimensions of 10 mm × 10 mm × 1 mm in a class 1000 clean room . The nominal uncertainty of these samples was ±3 Å in the crystal direction, and the surface roughness was less than 100 Å. Then, graphene was grown on copper foils  via low-pressure chemical vapor deposition and later transferred to the surface of the nickel samples. The specific steps of this process are shown in The Ni (111) and graphene/Ni (111) surfaces were characterized by X-ray diffraction, a field emission scanning electron microscope (FE-SEM) , and Raman spectrometry (HR800). The X-ray diffraction pattern was used to determine the crystalline phase of the nickel surface, and the SEM images were used to show the morphology of graphene on the Ni (111) surface. The Raman spectra of the graphene-covered samples were obtained using an excitation laser at 532 nm to investigate the monolayer graphene.−1 and the G’ peak at 2690 cm−1, which can be seen in the Figure, indicating the presence of graphene. The G peak can be slightly different for graphene on different substrates such as Si, glass, and NiFe [The characterization results confirmed the applicability of the experimental samples. The crystal plane of the Ni (111) surface was confirmed by the characteristic angle of 44.7° in the X-ray diffraction pattern . Figure and NiFe ,42,43, cand NiFe .p-PDOS, the density peaks of the carbon atom in the composite were lower in the energy range of −15–10 eV, while the density peaks of the red nickel atom in the composite were higher in the energy range of 0–17 eV. For the d-PDOS from s- and p-electrons are the main contributors to the charge transfer. To show more detail, s and p orbitals of Ni, as well as the p orbitals of carbon. This implies the hybridization between the nickel atom and the carbon atom, which contributes to the transfer of electrons.More results of DFT calculations will support this deduction as presented in z-axis direction of the graphene/Ni (111) interface can be further used in a future correction of SEY Monte Carlo simulation. Considering the variation of fermi energy level after the composite, the work function φ can be calculated for this composite structure, as shown in the second column of In addition, the redistribution of the electron density at the graphene/Ni (111) interface leads to a variation in the electrostatic potential, thus affecting the probability of electrons emitting and exiting the interface as well as the work function as Equation (1). Work function and SEY were measured before and after the coverage. The SEY measurement was carried out using a home-made SEY system as outlined in sulators .(2)δ=Is−10 mbar and the irradiation of 21.22 eV photons (He I line).The ultraviolet photoelectron spectra of the Ni (111) surface and the graphene covered ones were obtained using an ultraviolet photoelectron spectrometer (UPS)   composite interface to suppress SEY, which were validated by the results from an experimental study of surface modification with graphene on an Ni (111) surface. Moreover, the results of theoretical calculations provided a way to reveal the mechanism of SEE suppression and work function decrease on graphene/Ni (111) surfaces. A general strategy for achieving low SEY surface modification was summarized, which manifested that the work function fication ,51,52. T


Ventilator-associated pneumonia (VAP) is commonly overdiagnosed & a primary driver of antibiotic overuse within intensive care units (ICUs). Antimicrobial stewardship programs have successfully leveraged diagnostic stewardship interventions (DSIs) to prevent overdiagnosis/overtreatment of diverse clinical syndromes, yet this approach has not been extended to VAP. In this trial, we aimed to evaluate the safety, feasibility & efficacy of a novel DSI care bundle (DSI-CB) targeting VAP.The DIVA trial (NCT05176353) was a pilot/feasibility trial conducted in 2 ICUs at Michigan Medicine from February 2022-February 2023. A DSI-CB targeting the respiratory culture testing pathway was implemented sequentially in study ICUs, using an interruptive electronic health record clinical decision support tool & modifications to microbiology laboratory workflows (Table 1). Providers were counseled on DSI-CB use during bimonthly educational sessions during trial rollout & via monthly email reminders thereafter. Rates of prespecified co-primary safety and secondary efficacy outcomes were compared between the postintervention study cohort & 5-year preintervention historical controls using negative binomial regression. Interrupted time series analysis was used to evaluate ICU antibiotic utilization rates (ICU-AURs) to account for temporal trends.1810 patients were admitted to study ICUs following DSI-CB implementation, 29% of whom were eligible for DSI-CB use. DSI-CB was utilized in 77% of eligible patients. Patient demographics, comorbidities & measures of acute severity of illness were similar pre- & post-intervention. DSI-CB implementation was not associated with increases in primary adverse safety outcomes (Table 2). DSI-CB implementation was associated with significant reductions in rates of total respiratory cultures ordered, rates of positive respiratory cultures & reductions in both total & broad-spectrum ICU-AURs .Implementation of a novel VAP DSI-CB was safe, feasible & associated with significant reductions in rates of respiratory culture positivity and ICU-AURs. This represents the first trial of a DSI targeting VAP & a novel avenue for ICU antimicrobial stewardship. Large-scale trials are warranted.Owen Albin, MD, Biomeriux: Grant/Research Support|Charles River Laboratories: Advisor/Consultant|Shionogi: Advisor/Consultant Weirauch J. Andrew, RRT, Drager Medical: Equipment loaned for research purposes, but no monetary funds were provided.|Jones and Bartlett Learning: Honoraria Krishna Rao, MD, MS, Merck & Co.: Grant/Research Support|Rebiotix: Advisor/Consultant|Seres Therapeutics: Advisor/Consultant|Summit Therapeutics: Advisor/Consultant Keith S. Kaye, MD, MPH, Entasis: Advisor/Consultant|Entasis: Honoraria|GSK: Advisor/Consultant|GSK: Honoraria|Merck: Advisor/Consultant|Merck: Honoraria|Shionogi: Advisor/Consultant|Shionogi: Honoraria|VenatoRx: Advisor/Consultant|VenatoRx: Honoraria


Since its initial involvement in numerous neurodegenerative pathologies in 2006, either as a principal actor or as a cofactor, new pathologies implicating transactive response (TAR) DNA-binding protein 43 (TDP-43) are regularly emerging also beyond the neuronal system. This reflects the fact that TDP-43 functions are particularly complex and broad in a great variety of human cells. In neurodegenerative diseases, this protein is often pathologically delocalized to the cytoplasm, where it irreversibly aggregates and is subjected to various post-translational modifications such as phosphorylation, polyubiquitination, and cleavage. Until a few years ago, the research emphasis has been focused particularly on the impacts of this aggregation and/or on its widely described role in complex RNA splicing, whether related to loss- or gain-of-function mechanisms. Interestingly, recent studies have strengthened the knowledge of TDP-43 activity at the chromatin level and its implication in the regulation of DNA transcription and stability. These discoveries have highlighted new features regarding its own transcriptional regulation and suggested additional mechanistic and disease models for the effects of TPD-43. In this review, we aim to give a comprehensive view of the potential epigenetic (de)regulations driven by (and driving) this multitask DNA/RNA-binding protein. Epigenetic mechanisms in both general and specific neurodegenerative diseases are gaining momentum ,3,4,5,6.TDP-43 gained momentum in the neurodegeneration field when it was first discovered that almost all amyotrophic lateral sclerosis (ALS) cases and as many as half of frontotemporal dementia (FTD) cases present pathological ubiquitinated inclusions of TDP-43 ,8. SinceAt the functional level, TDP-43 is a highly conserved protein involved in the regulation of RNA processing. Mechanistically, TDP-43 is able to bind with different affinity both single-stranded (ss)RNA and ssDNA but also double-stranded DNA (dsDNA). From a structural point of view, the binding of TDP-43 to nucleic acids is mediated by two RNA recognition motif (RRM) domains in its N-terminal region ,21,22,23In agreement with its strong affinity for nucleic acids, TDP-43 localization is mainly nuclear, and cytoplasmic aggregation is attributed to pathological processes. However, it is now well recognized that TDP-43 is capable of shuttling back and forth from the nucleus to the cytoplasm, even under normal physiological conditions . On the Being a DNA/RNA-binding protein, TDP-43 is highly involved in many aspects of RNA metabolism, such as the control of alternative splicing (AS), microRNA (miRNA) processing, and messenger RNA (mRNA) stability and transport ,34,35,36UG-repeated sequences within RNA [During the last decade, TDP-43 has been mostly studied for the functions linked to its RNA-binding properties. Notwithstanding this focus, initial studies established the capacity of TDP-43 to bind to ssDNA TG repeats with at least the same efficiency as it does to thin RNA ,16,19,22thin RNA . Insteadthin RNA ,20,21 anthin RNA .More recently, additional studies have found TDP-43 to be able to specifically bind DNA sequences in promoter regions and affect the expression of several genes ,47,48,49As already mentioned, the function of TDP-43 as a more general transcriptional activator/repressor has been known for about a decade . Its invDrosophila leg, Sreedharan et al. identified three factors, namely, sgg/GSK3, hat-trick, and xmas-2, needed to mediate TDP-43Q331K toxicity [xmas-2 or hat-trick, implicated in chromatin remodeling and RNA export, affected TDP-43 post-transcriptionally, resulting in a reduction in TDP-43 protein level [For example, using a mosaic genetic screen to study motor neuron degeneration in the toxicity . Interestoxicity . Among ttoxicity . In paratoxicity ,55. Finain level .Drosophila photoreceptor neurons [In addition to this evidence, two recent studies using the suppressor screen techniques have led to the identifications of other epigenetic modifiers able to contrast TDP-43 neurotoxicity. In these two studies, human TDP-43 was over-expressed in a subset of  neurons , motor n neurons . Then, u neurons , while B neurons .e(y)3/PHF10; polybromo/BAF180; ash1/ASH1L; enok/KAT6A; br/-; Br140/BRPF1; and mor/BAF170S/MARCC2. The remaining, the Chromodomain-helicase-DNA binding protein 1 (Chd1) with two human homologues, CHD1/CHD2, is an ATPase involved in the remodeling and assembly of chromatin [Numerous genes implicated in nucleocytoplasmic transport or in pathways that are deregulated in TDP-43-related neurodegeneration were identified among the glial and motoneuronal TDP-43 suppressors of toxicity. However TDP-43-phenotype suppressors were principally composed of chromatin remodeling and basal transcription machinery factors. In particular, 25% of them were chromatin remodelers. Seven out of eight of these factors promote open chromatin as part of the Trithorax and SWI/SNF (Brahma) complexes, most of them with human known homologues: hromatin . Furtherhromatin . By hijahromatin . The ChdChd1 KD could cause an opposite effect on TDP-43 overexpression-mediated toxicity; in particular, instead of counteracting the effects of TDP-43 overexpression upon motor neurons KD, an exacerbation of toxicity was observed upon glial and photoreceptor neurons KD [Importantly, according to the different brain cells investigated, it was also observed that urons KD ,52. Thesurons KD .C. elegans, it was found that the TDP-43 homolog, TDP-1, could regulate the chromatin localization of another chromatin remodeler, HPL-2, the heterochromatin protein 1 homolog [tdp-1 mutant worm [Changing the model organism to  homolog . Direct ant worm . As a siant worm ,35. At tC9orf72 GC expansion (C9ALS) or sALS without mutations in common ALS-linked genes [Additional evidence of TDP-43 function in chromatin remodeling and its relevance to neurodegenerative diseases comes from the study of nBAFs proteins in cultured mouse motor neurons expressing ALS-linked mutant (G418C and A315T) human TDP-43 . The Braed genes .M337V, whereas TDP-43WT overexpression led to a significant increase in H3K9me3. On the contrary, no relevant global losses or gains of these epigenetic marks were observed for the TDP-43A382T mutant [The contribution of TDP-43, and especially of its ALS-related mutants to more global epigenome alteration, was also recently tested in the human neuroblastoma SH-SY5Y cell line, together with other ALS-causative proteins, SOD1 and FUS . In thisT mutant .WT expression [In line with these findings, the fly Chd1-TDP-43 interaction study previously mentioned was part of a broad in vivo RNAi screen to search for TDP-43 toxicity modifiers . This scpression . Note thpression .HDAC6 mRNA, regulating both its mRNA and protein expression in neuronal and non-neuronal cell lines [Drosophila model of TDP-43 proteinopathy reduced the amount of insoluble poly-ubiquitinated proteins and ameliorated the lifespan and climbing defects associated with the overexpression of both TDP-43 and Ataxin-2 (ATXN2). These results indicated that HDAC6 could modulate, albeit in a non-enzymatic manner, the TDP-43 activity via the autophagy–lysosome pathway (ALP) [Finally, two HDACs, HDAC1 and HDAC6, have been shown to influence and to be influenced by TDP-43, respectively. Thus, it has been shown that the silencing of both HDAC1 in SH-SY5Y and its fly ortholog Rpd3 in Drosophila is able to mitigate the toxic effect induced by TDP-43 expression . Notablyll lines ,60. In oll lines . On the ll lines . In 2020ll lines . They foay (ALP) . NAP1L1 genes, on the contrary, were all downregulated [Hist1h3 and Hist1h4 mRNAs were aberrantly polyadenylated, while at least 10 out of 15 variant histones were slightly but significantly downregulated in the TDPΔNLS bigenic mice [At the level of gene expression, substantial alterations were observed in the cortices of transgenic mice expressing inducible WT or mutant hTDP-43 lacking the nuclear localization signal (tTA/TDPΔNLS). These alterations appeared even before the onset of significant gliosis and neuronal cell loss . Despiteegulated . Althougegulated . In partnic mice . In partnic mice , thus fuTo relate these findings to the human pathological condition, it is now known that not all cells in the brain of a patient present a reduced load of nuclear TDP-43, and the transcriptome of these cellular populations was recently investigated . To achiDNA methylation is another major epigenetic modification, acting on DNA itself, rather than on the chromatin or nucleosomal proteins wrapped around it. At the biological level, DNA methylation is established via DNA methyltransferases (DNMTs) and is passively erased during DNA replication or, as can be more relevant for neuronal cells, by active replication-independent mechanisms involving oxidations steps mediated by the ten-eleven translocation (TET) enzymes and base excision repair ,67,68. DC9orf72, TARDBP, SOD1, or FUS, as well as datasets from patients’ biopsies [No relevant changes in global DNA methylation were observed by Masala et al. in the human neuroblastoma SH-SY5Y cell line overexpressing WT or mutant ALS-linked proteins, including TDP-43, as cited above ; howeverbiopsies . Analysibiopsies . These rbiopsies . In addibiopsies . MeCP2 ibiopsies .Cell cycle alterations have also been reported following TDP-43 suppression. In two recent publications, TDP-43 activity was linked to sister chromatid cohesion through the splicing regulation of a cohesin complex subunit, namely, Stromal Antigen 2 (STAG2). In particular, depletion of TDP-43 in HeLa and neuroblastoma cell lines upregulated STAG2 exon 30b inclusion ,78. AccoTAF1, and e(y)1 orthologs of the mammalian TAF1 and TAF9 transcription factors, members of the TFIID initiation complex, and also Tombola involved in the transcriptional activation of the male germline during meiosis [Finally, genes related to transcriptional machinery constitute another broad category of TDP-43-phenotype suppressors that have been identified thanks to several screening techniques. These genes include the transcription elongation factor, Su(Tpl) ,79, whic meiosis . The alt meiosis , thus reTaken together, these studies on chromatin factors interacting with, modified by, or phenotypically rescuing TDP-43, indicate a potentially important role of TDP-43 as an epigenetic regulator with a high capacity for modulating chromatin, transcriptional processes, and DNA damage/repair pathways. A synthesis of the identified factors can be found in Since 1995, when TARDBP was first identified as being able to bind TAR motif within HIV proviral DNA , a dozenAcrv1 gene coding for the sperm acrosomal protein SP-10 led to the discovery that TDP-43 can bind and repress this gene [Acrv1 was found to occur in vitro via two GTGTGT motifs located within the Acrv1 promoter and the N-terminal RRM1 domain of TDP-43. TDP-43 was able to tether Acrv1 at the nuclear matrix, impeding promoter–enhancer interaction, thus acting as an insulator [Acrv1 gene promoter in several non-neuronal tissues and cell lines, with different intensities, but it was not always able to maintain transcriptional silencing. However, TDP-43 presence in spermatocytes was necessary in order to Acrv1 silencing at this stage. As the authors mentioned, this suggests that biological conditions exist under which TDP-43 does not act as a transcriptional repressor [Acrv1 promoter TDP-43-mediated repression was specifically associated with histone H3 dimethylated K9 (H3K9me2) [For example, studies on the testis-specific mouse his gene ,39,40. Ac-fos core promoter by using a fusion construct between the DNA-binding domain (DBD) of Gal4 protein and TDP-43, and by coding Gal4-binding sequences upstream of the c-fos promoter. In HeLa cells, the use of this system led to the repression of the downstream luciferase reporter gene, respective to the use of Gal4 DBD protein alone. Similar constructs with Gal4 DBD fused to p53 protein, on the contrary, enhanced luciferase expression [This study also illustrated a potential generic repressor function of TDP-43. This property was demonstrated by artificially bringing TDP-43 in proximity of the pression , therefoParticularly relevant for ALS is the work of Schwenk et al., that revealed a mechanistic link between nuclear loss of TDP-43, TDP-43 gene expression regulatory functions and trophic signaling alteration in neurons . The autneuroLNC and found it to strictly localize in the cell nucleus and to be implicated in synaptic vesicle (SV) release. neuroLNC lncRNA is conserved from rodents to humans, and its expression appears highly restricted to the brain, and more specifically to neuronal cells. Interestingly, mass spectrometry (MS) analysis for protein interactors highlighted TDP-43 as the highest and only highly significant enriched protein interacting with neuroLNC. Further IP assays against TDP-43 confirmed their interaction and featured the importance of the neuroLNC RNA UG-repeats in the interaction, since a neuroLNC with mutated UG-repeats loses its ability to bind to TDP-43. At the functional level, downregulation of TDP-43 abolished the effects of neuroLNC overexpression on synaptic vesicles, and the UG-repeats-mutated neuroLNC was unable to potentiate SV release. Like TDP-43, neuroLNC is chromatin-associated, as shown by DNA ChIRP-seq analysis, and localized chiefly at intronic regions (82%) and at the upstream regulatory regions (13%) of genes. The ChiRP also revealed the binding of neuroLNC to several classes of RNA. Gene ontology (GO) analysis of the DNA- and RNA-bound elements highlighted several neuronal genes implicated in neurotransmitter release, synapse organization, glutamatergic signaling, and regulation of neuritogenesis [neuroLNC in the nucleoplasm or on chromatin has not been clearly established, and whether neuroLNC promotes the transcription of these genes and/or the stabilization of the mRNAs that are bound will deserve future studies [neuroLNC in ChIRP experiments are only partially overlapping [neuroLNC that may not all be related to TDP-43. Another additional mechanism potentially linking TDP-43 nuclear functions to neuronal signaling was recently identified [neuroLnC is the best-characterized example of a neuron-specific lncRNA- TDP-43 interaction with implications on the regulation of gene/chromatin. However, there are additional examples already documented in other tissues that suggest a wider role for TDP-43–lncRNA interaction. For example, a previous study showed that TDP-43 is part of a proteins–lncRNA Xist condensate, and is required for anchoring Xist to the inactive X (Xi) and for the silencing of the Xi-territory in ESCs [Cyp8b1 transcription [lncLSTR, a liver-enriched nuclear lncRNA with lipid-lowering effects. Direct interaction of lncLSTR with TDP-43 was demonstrated via reciprocal pulldown experiments in liver tissue [At present,  in ESCs  . In this way, TDP-43 was found to act as a mediator of LPS promotion of the pro-inflammatory factor TNF-alpha, a result confirmed by both siRNA knockdown and the overexpression of TDP-43 [TNF-alpha mRNA upregulation [TNF-alpha promoter, and suggested that TDP-43 could be the factor by which NF-kB reaches the TNF-alpha promoter [Surprisingly, other examples of recent evidence indicate a role for TDP-43 in the positive regulation of the transcription of other genes. One example is represented by TNF-alpha activation in human monocytic cells THP-1, differentiated into macrophages by PMA and stimulated by LPS . Analysif TDP-43  , not acetylation-null (KK-AA) in the RRM1–RRM2 region of TDP-43, were found to abolish CHOP transcriptional activation. On the contrary, CHOP promoter activity was enhanced by HDAC1, which deacetylated WT TDP-43 [TNF-alpha and CHOP promoters are still unknown.Another recent study reported a case of TDP-43 behaving as a transcriptional activator using both ChIP and a luciferase reporter assay in SH-SY5Y, this time activating the C/EBP-homologous protein (CHOP) promoter, also known as DNA-damage-inducible transcript 3 (GADD153) . Indeed,radation . Recent promoter   [Myolinc and TDP-43 are critical to activating myogenic regulatory networks for the differentiation of myoblasts into myocytes and for the subsequent formation of multinucleated myotubes. Lack of Myolinc relocalized TDP-43 to other regions and abrogated activation of the myogenic regulatory network [Myolinc has been observed in other tissues, including in the brain, albeit at lower levels. In addition, an siRNA against TDP-43 not only significantly reduced the gene expression levels of these muscle genes but also that of Myolinc, suggesting that the Myolinc gene itself is also under the control of the TDP-43 protein [MyoD1 in Porcine muscle satellite progenitor cells, thus representing another lncRNA involved in TDP-43-mediated muscle differentiation. Although the precise underlying mechanisms at play are yet to be elucidated, H19 has already been reported to directly interact with TDP-43 [As shown for TDP-43-mediated gene repression, gene activation can also be mediated by lncRNA-TDP-43 interaction. Thus, in mouse skeletal muscle, the interaction of TDP-43 with a muscle-enriched lncRNA called  Filip1)   repeat expansions, and the PCR2 HMT subunit EZH2 was found largely insoluble [About 7 years later, a higher resolution of the genome localization of TDP-43 was first given on its Drosophila homolog, TBPH, by a plethora of experiments based on ChIP-seq, RNAi depletion, transcription blockade, affinity chromatography, and immunoprecipitation conducted in Drosophila . This stnsoluble . Interesnsoluble . TDP-43 nsoluble . siRNA-insoluble . Still, nsoluble . As TDP-C9orf72 poly(PR) ((PR)50) mutant and the interesting finding that (PR)50-induced neuronal death can be dampened via p53 inhibition, the authors nonetheless obtained very interesting findings regarding TDP-43 neuronal overexpression. Despite the neurodegeneration looking “grossly similar”, the modifications of the underlying chromatin and gene expression programs were different. TDP-43 and C9orf72 (PR)50 conveyed unique chromatin and transcriptional footprints. Loss of chromatin accessibility was observed for all lentiviral-treated cultures, even the GFP control; however, a gain in chromatin accessibility was observed for TDP-43 after 60 h and associated with a chromatin more accessible for a variety of TFs, as evidenced via ChromVar, and several gene co-expression networks were deregulated [At the beginning of 2021, Maor-norf and colleagues, working on mouse cortical culture and combining ATAC-seq and RNA-seq, investigated the consequences on the chromatin accessibility of ALS-related protein overexpression . Though egulated , findingAs a result of these investigations, it appears that TDP-43 has a broad ability to affect the transcription of all categories of genes, from coding to non-coding classes, to a degree that is greater than had been previously appreciated. This can be achieved indirectly through the modulation of genes involved in chromatin remodeling and transcription, or directly via association with genes promoters. While direct, multimodal regulation, either repressive or activating, has, as discussed above, been reported for several genes, understanding of the general function of TDP-43 at the TSS of active genes genome-wide still requires further investigation. It was proposed that the transcription-independent binding of TBPH, and hence possibly of TDP-43, could serve to reduce the fluctuations in the levels of transcription over time, with the intriguing possibility that the aggregate-prone low-complexity C terminal domains in TBPH might also facilitate enhancer–promoter looping or loops stabilization .Acrv1 gene promoter activity during mouse spermatogenesis [Remarkably, Nie and colleagues reported very recently on the requirement of the maternal (oocyte) TDP-43 protein to activate the zygotic genome during embryogenesis by promoting RNA Pol II transition from a paused to an elongating state . Experimogenesis , the herogenesis . Overallogenesis , myogeneogenesis , and embogenesis ).Alongside the TDP-43 function in gene transcriptional regulation, several recent studies have strengthened the potential role of TDP-43 in genome stability and DNA repair ,94,95,96Upon DNA damage induced in pluripotent stem cell (iPSCs)-derived motor neurons from a healthy subject, or in differentiated neuronal line SH-SY5Y, normal TDP-43 is rapidly recruited at double-stranded breaks (DSB) sites. TDP-43 was shown to stably interact with DNA damage response (DDR) and neighbor homologous end-joining (NHEJ) repair factors. Specifically, it acted as a scaffold protein for the DDR complex  and the break-sealing XRCC4-DNA ligase 4 complex , mediating its recruitment at induced DSB sites ,93. In vitro experiments further showed that TDP-43 can directly bind dsDNA oligonucleotides with free blunted ends, but not if ends are biotin-blocked or in case of a ssDNA break , thus suAs expected from these findings, deprivation of TDP-43 led to an accumulation of DNA damage. As such, TDP-43 deprivation in cycling iPSCs-derived NPCs and SH-SY5Y conveyed an accumulation of endogenous DSBs, despite DDR activation, with an increase in γH2AX, p53BP1, and pATM at 96 h after TDP-43 KD . SubsequListeria monocytogenes [Listeria monocytogenes causes SIRT2 accumulation in the nuclear and chromatin spaces. SIRT2 is a deacetylase and its translocation to the chromatin provoked a global loss of H3 Lysine 18 acetylation (H3K18ac), a mark enriched at the TSS of transcriptionally active and poised genes. On a local scale, both SIRT2 and H3K18ac were redistributed. SIRT2 enriched at the TSS of a large subgroup of genes that lost H3K18ac and became repressed, and get depleted at other genes that gained increased H3K18ac and became activated [Additional insights into the protective role of TDP-43 against DNA damage and the mechanism behind it come from a recent work on the bacterial pathogen ytogenes . Upon inctivated . Eldridgctivated . Mechanictivated . As obsectivated . In the ctivated . In the ctivated , but itsPOLDIP3 exon 3 was significantly altered in different cell lines depleted for TDP-43 and other hnRNPs linked to TDP-43 functions [In addition to a direct intervention of TDP-43 at DSB site, TDP-43 was shown to be important for the production of two proteins involved in DNA repair, SIRT1 and POLDIP3 . SIRT1 is a Sirtuin implicated in dsDBR and is required for cell survival. RNA-IP and RNA pull-down assays in human neuroblastoma SH-SY5Y and embryonic kidney HEK293T cells demonstrated that TDP-43, in complex with FMRP  and STAU1 (Staufen) proteins, specifically binds to the 3′-UTR of SIRT1 mRNA and positively regulates its stability and hence its protein production  Figure D. In a cunctions ,77,78, aunctions . Althougunctions ,106. HowInterestingly, a role in the prevention and/or repair of DNA damage has also been proposed for FUS, another well-characterized fALS-linked protein, both in the motor neuron-differentiated neuronal cell line and in non-neuronal dividing cells ,107,108.Apart from their gene regulatory function, R-loops can also function to promote DNA repair, particularly in the context of transcriptionally coupled repair ,110. IntLnc530, localizes to R-loops, controls their levels, and preserves genomic stability. To understand how Lnc530 regulates R-loops, they performed in vivo RNA pull-down with MS analysis and found two strong candidates, DEAD-box RNA helicase 5 (DDX5) and TDP-43, with whom the Lnc530 forms a DDX5- Lnc530-TDP-43 complex that prevents unwanted R-loop formation and elevates the concentration of DDX5 and TDP-43. [Lnc530-TDP-43 complex, probably elevating the local concentrations of DDX5 and TDP-43 to regulate the resolving of R-loops [Lnc530 expression is much less abundant in differentiated cells, its ectopic expression in such cells effectively increased the recruitment of DDX5-TDP-43 at R-loops and reduced their aberrant formation [Lnc530 expression in different brain regions of mice at even higher levels than that in mESCs. If Lnc530 participate in TDP-43, R-loop regulation in mice brain is should be further examined. Similarly, the functionality of the human Lnc530, reported to show only partial conservation with mice Lnc530 [The key role of TDP-43 in preventing R-loop accumulation has been further highlighted in the recent work of Gong et al. . Studyin TDP-43. . RNA-pul R-loops . While Lormation . Interese Lnc530 , and it Q331K had a reduced interaction with XRCC4 and Ligase 4, both in unstressed and irradiated cells, and prevented XRCC4-Lig4 nuclear translocation. The authors showed that in addition to defective DNA repair, Q331K expression induced ROS stress, at least in cycling cells, thus fueling the vicious cycle [The link between TDP-43 function in DNA stability and ALS features was also supported by the fact that the spinal cord DNA of a ALS patient presenting the TDP-43 Q331K mutation showed a higher level of γH2AX, a DNA single- and double-stranded break marker, compared to age-matched controls . In the us cycle . Loss ofus cycle . This waus cycle . Finallyus cycle  . In parallel, their subsequent within-germline propagations by means of retrotranspositions or reinfections (copy–paste-like mechanisms) over millions of years led to the formation of several multicopy families that group under the long terminal repeat (LTR) class of TEs. Retroviral ORFs , pro/int/pol , env (envelope glycoprotein), and accessory proteins) accumulated disruptive nonsense mutations and proviruses often recombined leading to solo-LTRs. In the human, HERV-derived copies and fragments represent about 8% of our genomic DNA ,115,116.The long interspersed elements (LINEs) constitute another important class of retrotransposons; they are able to conduct autonomous self-propagation via another copy–paste mechanism thanks to their ORFs encoding ribonucleoproteins, endonuclease, and reverse transcriptase. They account for 17% of the human genome, and several of them, albeit representing a small fraction, are polymorphic within the population . They diOverall, TE subfamilies are species specific, but they rely on the same molecular mechanisms for their control and propagation , notablyBeing highly repetitive by nature, TEs are routinely dismissed from deep-sequencing analyses if not under specific focus, although new sequencing modes have greatly improved their mappability. However, by reanalyzing a series of deep sequencing datasets from RIP-seq and iCLIP-seq from normal brains of rat, mouse, and human, the group of Dubnau uncovered an extensive binding of TDP-43 to TE transcripts . In thisSOD1 mRNA (61%), or a strong bias for inflammation and pan-glial cells activation (19%).Importantly, this physiological binding of TDP-43 to TEs was observed to be altered in at least two of the major TDP-43 proteinopathies: FTLD and in a specific subtype of ALS ,138. In These conclusions were broadly supported by analyses performed in human SH-SY5Y neuroblastoma cells, where the use of CLAM, a tool designed to handle repetitive reads on sequencing data of TDP-43-bound RNA obtained by using enhanced cross-linking and immunoprecipitation (eCLIP-seq), unmasked 439 TE-derived RNA bound to TDP-43, corresponding to 31% of all mapping reads . SpecifiAll these data support a specific functional and conserved role for TDP-43 in the repression/regulation of TE elements. Importantly, misregulated TE expression can have a number of detrimental impacts on chromatin, such as those observed in ALS and other neurodegenerative diseases. They may include genome instability via the spurious integrations of new repeats, activation of the DNA-damage stress response, or deregulation of the neighboring genes A.pol gene containing mRNA, identified several actively transcribed loci in the HERV-K HML-2 and 3 subfamilies, including specific copies with protein coding potential lying within a candidate interval for MND, in which the susceptibility genes were not identified [gag, pol, and env retroviral genes regions in a correlated dose-dependent manner, supporting the activation of proviral forms of HERV-K [An increased expression of the primate specific ERV-K family in a subgroup of sALS patients was reported in at least two studies ,141, andentified . Expressentified . In the Mechanistically, the knockdown of endogenous TDP-43 with siRNA reduced HERV-K expression, thus arguing against a derepression of a HERV-K copy (or copies) caused by overexpression-mediated nuclear depletion of TDP-43 in the neurons of these patients or in vitro. In addition, ChIP assays, together with in vitro luciferase assays on the HERV-K LTR in HeLa cells, confirmed the activating effects of TDP-43 load and binding onto the LTR . FurtherHeterochromatic regions are typically enriched for different types of intergenic repeats and depleted from genes. In agreement, the loss of heterochromatin identified in post-mortem human ALS brain nuclei without TDP-43 by Liu and colleagues via ATAC-seq was enriched for a particular class of interspersed intergenic repeat, i.e., the LINE1 elements . ImportaThese results suggest that there may be an accumulation of LINE1 nucleic acids in TDP-43-negative nuclei, which can potentially increase LINE1 DNA content, even in the absence of complete retrotransposition leading to truncated L1 . IncreasL1 RNA was shown to negatively regulate the enzymatic activity of the H3K9me3 SUV39H1, thus sustaining heterochromatin loss [Therefore, in the brain of ALS patients, TDP-43 alterations may lead to LINE-1 reactivation via H3K9me3 reduction and chromatin decondensation, but in some instances, they could also be directly linked to the increase in L1 new copies integrated into the neurons genome. It is interesting to stress that in another pathological condition, i.e., a mouse model of progeria, tin loss . A schemDcr-2 mRNA and protein, regulating both its levels and activity [Flies have often represented a good model for TDP-43 deregulation and ALS. For this reason, TDP-43 impact on TE was recently examined  has also been demonstrated to be effective in partially reverting the locomotion defects in TDPH-deficient flies induced by RTEs activation, with azidotimidine been the most efficient. Enotaxin, a compound capable of activating the siRNA pathway and able to counteract RTE activation, was also able to restore the locomotive behaviors and the formation of neuromuscular synapsis .Naturally occurring splice variant isoforms of TDP-43 leading to shorter TDP-43 proteins have been revealed on several occasions since the early 2000s ,157, butAcrv1 gene regulation by TDP-43, the author identified several RNA isoforms of mTDP-43 in testicular tissue [Acrv1 promoter in GC-2 cells or minimal c-fos promoter in HeLa cells, these variants were able, like the TDP-43 FL, to repress their expression [For example, in the study on the r tissue . These Tr tissue . When prpression  , a result that is in accordance with the lack of the glycine reach C-term region . Their pAnother intriguing finding of the work performed by Giannini and colleagues is the presence of the TDP-35 form at chromatin at R-loop, as highlighted by co-IP in both whole-cell lysates and chromatin fractions of lymphoblastoid cell lines (LCL). Regarding the importance of TDP-43 disease-associated mutations, it is interesting to note that this interaction was higher in for LCL carrying the A382T mutation of TDP-43 .2+-activated calpain cleavage produces N-term fragments identified to be of about 36, 34, and 32 kDa [Malat-1 lncRNA binding to TDP-43 in the nucleus [The authors initially understood TDP-35 to correspond to CTF35, a C-terminal fragment of 35 kDA, resulting from the truncation TDP-43  using and 32 kDa . Anotherd 32 kDa . Notablyd 32 kDa ,163. Thid 32 kDa  could be nucleus . In any  nucleus . Finally nucleus ,159 or t nucleus . Indeed,TARDBP mutations have been identified mostly in familial ALS patients but also in sporadic FTD, AD, and PD cases, and more than 50 TDP-43 variants have been linked to the incidence of ALS/FTD ,166. TheFew TDP-43 models carrying null or point mutations have been investigated to explore the association of pathological TDP with altered epigenetics treats. We have reported them in the previous sections in relation to their impact on chromatin in their dedicated sections. In the present paragraph, we condense the impact of TDP-43 mutations on chromatin homeostasis from a mutation point of view. Acrv1 promoter [CHOP transcriptional activation [Depending on the regions hinted by mutations, different scenarios on chromatin impact can be envisaged. Indeed, mutations in the C-term—known to guide nuclear loss—are expected to have a broad impact on TDP-43 functions both at the RNA and the DNA levels. This might naturally hold true for mutations within the NLS or the NES controlling the nucleocytoplasmic shuttling. Instead, mutations in the N-term, whether at the RRM1 or RRM2, may have a more focalized impact on the RNA-processing aspect or on chromatin, whether linked to RNA processing aspects or lncRNA-related functions of TDP-43 on chromatin, but also on TDP-43′s ability to bind ssDNA or dsDNA, as has been documented in different studies ,20,21,22promoter  and on ipromoter . In additivation . Insteadtivation . Expresstivation ,64) convAll ALS/FTD TDP-43 mutations reported to date to have an impact on chromatin are concentrated in the C-term region and lead to either a defect in DNA methylation or DNA damage or to both, and some also impact TDP-43 own regulation .Finally, as we detail further in the next section  with different susceptibility according to the cell type and/or differentiation stage ,159,160 y SUP-46 . In party SUP-46 . SUP-46 y SUP-46 ,182. TheOne thing that can be said, however, is that the TDP-43 isoforms appear comparatively much less expressed than TDP-43 FL mRNA in human iNeurons and WT mouse cortex . HoweverTARDBP transcripts, sTDP43-1 and sTDP43-2 splice events were found to be highly enriched in lumbar motor neurons, reaching 17% and 22% of total TARDBP transcripts, respectively. In the human, by re-examining available RNA-seq data, the authors consistently observed significant expression of sTDP43-1 but not sTDP43-2 in several different regions of the CNS, including but not limited to the spinal cord ventral horn, spinal motor neurons, cerebellum, and frontal cortex, making from 30% up to 55% of the TARBDP transcripts. In the lumbar motor neurons, sTDP43-1 even reached almost 70% of the total transcripts against less than 10% of TDP-43 mRNA. Lumbar glial cells also contained significant amounts of the isoform proteins. No significant differences between control, sALS, and C9ALS  patient samples were identified [Thus, in mouse, compared to frontal cortex homogenate where they contribute around 1% of entified . These dentified . In addientified . As for Although TDP-43 is ubiquitously expressed and can regulate/maintain its own expression through the negative feedback loop discussed above, some observations suggest that its overall expression level is not frozen but can also experience regulated variations in time and space. In particular, each tissue has its specific amount of TDP-43, and these are adequately compensated in Tardbp +/− mice in physiological condition . In addiThus, regulation of its expression might also occur at a more classical transcriptional level through its promoter. While the mechanisms of it auto-regulation by splicing and NMD decay have been the focus of many efforts, the promoter features have been less intensively investigated until the last two years ,173,186.In 2009, prediction of the TARDBP promoter identified a bipartite promoter made from the about 500 bp before the exon1 TSS and two regions within the intron1 . From a ChIP-seq tracks from the UCSC Genome Browser show that the histone mark H3K4me3, the enrichment of which marks active promoter regions, is indeed found from upstream exon 1 (TSS) down to exon 2 in the human cortex  and in oThe TSS of TDP-43 FL NM_007374.4 results as the main TSS , but adChIP analyses in HEK293T cells revealed that TDP-43 binds to its own upstream-and intron1 bipartite promoter . SpecifiIn parallel, hnRNP-K, another hnRNP, was shown to bind to the TARDBP promoter, most probably at its predicted i-motif located upstream (at −371_−309) of the reference TSS, which represents a motif particularly well-conserved between human and mice. At the functional level, hnRNP-K binds to TARDBP promoter and appears to act as a dose-dependent activator of transcription in luciferase assays , possiblIn addition, the upstream promoter region of TARDBP appears to drive high transcriptional activity in cell lines of neuronal origin and in HeLa when compared to the non-neural human embryonic kidney 293 cells , suggestIn the 2009 study, non-coding DNA variants investigated in the upstream promoter or intron 1 region of the TARDBP gene were detected quite frequently (35%) in the brain  of sALS patients (16/46), including two promoter variants found more frequently in sALS patients than in controls . These dTardbp mRNA and TDP-43 expression as observed in normal aging mice in muscle and brain. It is therefore probable that similar epigenetic modifications modulate the expression of human TARDBP locus . In addition, no such epigenetic changes were noted in the liver, suggesting some tissue-specific susceptibility [A second potential line of regulation of TDP-43 transcription involves epigenetic modifications. Specifically, DNA methylation at CpGs has been found to be important for TDP-43 nonsense-mediated decay-isoform production and autoregulation, as reported above. In addition, CpG methylation is well known to regulate gene expression at promoter regulatory regions. The human TARDBP holds a large CpG island with at least three CpG clusters along upstream-intron1 bipartite promoter, accounting for 123 CpG ,186. In The treatment for ALS involves the multidisciplinary management of symptoms and the use of drugs, principally neuroprotective, neurotrophic, anti-inflammatory, antioxidative, and anti-glutamatergic drugs . Many efClinicalTrials.gov Identifier: NCT05193994). Here, it is important also to underline that, apart from the ARV effect on HERV-K, lamivudine is also a well-known inhibitor of the LINE-1 retrotransposition [Alongside TDP-43 itself, the many studies reported in this review also open routes to new targets for treatment, notably pharmacologic inhibition of retrotransposons, even in the absence of overt retrotransposition, or endogenous retroviruses proteins. In particular, inhibition of the HERV-K family env protein may mitigate the neurotoxic effects and/or spreading of TDP-43 pathology. The therapeutic use of an antiretroviral (ARV) cocktail has already been explored to some extent. Some HIV-infected patients develop ALS-like symptoms (HALS) , maybe lposition , widely ClinicalTrials.gov identifiers: NCT03574428 and NCT03179423) [HERV-K env glycoprotein, when produced in the diseased cells, should be directed to the cell plasma membrane and exposed at the surface. Indeed, focal accumulations of HERV-K env at the cell membrane of cortical neurons and motor neurons in the lumbar spinal cord have been evidenced in some ALS patients . Thus, i3179423) ,203).Epigenetic modifications do not modify the DNA sequence but are generally stable. Many are reversible, and pathological TDP-43-related modifications, either caused by TDP-43 or causing TDP-43 alterations, could constitute a new era of therapeutic target investigations for TDP-43 proteinopathies. Targeted delivery of molecules modulating the toxic impact of TDP-43 alterations, such as the ones presented in the first paragraph on chromatin modifiers, could represent a path for new therapies and could, notably, benefit from novel pharmacological approaches derived from research against cancer .C9orf72 repeat expansion in patients-derived iPSCs and the promoter of the APP protein involved in Alzheimer’s disease in HEK293T. The manipulation of DNA methylation notably employed HDR, not NEHJ [Moreover, a more meticulous investigation on functions and targets specifically related to the short protein isoforms of TDP-43 on chromatin would bring further insight to the TDP-43/TARDBP pathologies and onset. Furthermore, it will bring a deeper understanding of TARDBP gene regulation and isoforms modulations, hopefully providing reliable future directions for new therapies. In particular, targeted manipulation of the DNA methylation status of the TARDBP 3′UTR could represent another way of correcting TDP-43 autoregulation. Technologies using dCas9-DNMT3a fusion protein constructs can direct specific on-site targeting of DNMT3a by accurately designing guide RNAs , or the not NEHJ ; thus, inot NEHJ . AlthougIn this review, we have emphasized the broad role of TDP-43 in the chromatin context, and, conversely, the potential role that could be played by the epigenetics on its own regulation. The results of all these studies show that TDP-43  has many interconnections with chromatin and can profoundly impact chromatin homeostasis and gene expression through a range of different modalities. TDP-43 thus appears to be a pleiotrophic protein whose perturbation alters a wide variety of crucial cellular functions. It is important to state that most of the reported works have been performed on cellular models or on brain samples from ALS and FTD–ALS patients post-mortem. Therefore, we still lack confirmation in advanced disease models and in human early disease stages. Gaining information at earlier stages could presumably allow us to identify some targets as early biomarkers. In addition, as described in the introduction, ALS and FTD–ALS are not the unique neurodegenerative contexts in which TDP-43 abnormalities are observed. Notably, TDP-43 abnormalities in LATE, Alzheimer’s and Huntington’s diseases and brains after traumatic brain injury (TBI) have already been well described. However, TDP-43 inclusions are now shown to appear in a large panel of neurological and muscular disorders, as presented in a recent review . TherefoAttention must also be drawn to the diversity of the lncRNAs interacting with TDP-43. We reported a variety of them, which we discussed in relation to the process in which their functional interaction with TDP-43 has been shown. However, we limited our review to the processes with a direct impact on chromatin: either chromatin eviction or targeting for transcriptional regulation, or else for DNA repair. Still, it is worth underlining that TDP-43 interaction with at least two other lncRNAs has been described, namely. NEAT1 long isoform (NEAT1_2) and LCETRL3. NEAT1 promotes TDP-43 inclusion in NEAT1 nuclear paraspeckles by liquid–liquid phase separation in case of stress, forming protective nuclear bodies . The proQ331K knock-in mouse reported weight gain and age-dependent increases in food intake and a generally intact innate exploratory digging behavior in the mutant female compare to the male [An additional factor to be considered in TDP-43-linked pathologies is the role that gender has in the prognosis of ALS-FTD. Population-based datasets have highlighted a male prevalence of ALS cases with a 2:1 gender ratio , althougthe male . Thus, fFinally, the new technological possibilities enabling single-cell analysis or TDP-43 nuclear loss-based differential sorting appear crucial. Such cell partitioning can be used for single or multi-omic data analysis, for example, such as in transcription, DNA methylation, or chromatin accessibility , to idenSources specific to the epigenetic aspects regarding TDP-43 for this review were identified via PubMed searches using the key terms “TDP-43”, “TDP43”, or “TARDBP” AND the epigenetic features “DNA methylation”, “Methylation ”, “Chromatin”, “Chromatin associated”, or “Epigenetics”, or the RNA/DNA elements “lncRNA ”, “miRNA”, “Retrotransposons”, or technical methods “ChIP”, “RIP”, “RNA-IP”, or “ATAC-seq”. No time limitation was applied (up to July 2023), with the aim of covering the thematic of the review as exhaustively as possible, including its implication for neurodegenerative pathologies. Additional sources were taken from the references used in the above-retained research or review articles and from the publications already known by the authors. No bias was assigned for authors or institutions. Manual curation was performed to remove protein post-translational modifications  not directly linked to TDP-43 epigenetic regulation. Likewise, resources treating the implication of TDP-43 in RNA splicing with no clear consequences for epigenetic processes or in miRNA processing were not included as they were already covered by other recent reviews. When a review was used as a resource, it was cited in the text.


The photocurrent measurements indicated that thepresence of graphene considerably contributed to the visible lightutilization and photocatalytic efficiency of g-C3N4. This contribution was also revealed by the UV–visdiffuse reflectance spectra measurements, which showed that the incrementaladdition of the graphene reduced the optical band gap of the nanocompositeincrementally. The photocatalyst performance of the g-C3N4/graphene nanocomposite was also observed in the photo-assistedcharging tests of the Li-ion oxygen battery, and the presence of 2Dgraphene in the structure improved the effectiveness of g-C3N4 in the reduction of the charging potential, especiallyat high current densities.In this work, weaimed to synthesize an effective nanocompositephotocatalyst for the photo-assisted charging of the Li-ion oxygenbattery. Initially the graphene films were synthesized by chemicalvapor deposition, and subsequently, g-C Dye-sensitized TiO2,1 g-C3N4,2 TiN/TiO2/carbon cloth,3 Au/TiO2 nanotubes,4 TiO2/Fe2O3,5 WO3/g-C3N4,6 and rGO/g-C3N47 were synthesized as photocatalysts for the photo-assisted chargingof the Li-ion oxygen batteries. In addition to the thermodynamic requirements,the visible light harvesting efficiency of the photocatalyst is ananother criterion in the reduction of the charge potential at highcharging current densities.7The photo-assisted chargingof the Li-ion oxygen batteries withthe aid of triiodide/iodide (I9 Graphitic carbon nitride(g-C3N4), a 2D nonmetallic semiconductor, isa very promising photocatalyst owing to its convenient light harvestingband gap (2.7 eV), good physicochemical stability, and easy and low-costsynthesis.14 However, the severe recombination of the photogenerated electron–holepairs, low surface area, and low electrical conductivity restrictits application.15 The synthesis of g-C3N4-based nanocomposites with the carbonaceous nanomaterialsis accepted as the most effective pathway to overcome these handicapssince they are the most compatible constituents of the nanocompositesdue to their similar carbon network and sp2-conjugatedπ structure.24Two-dimensional(2D) materials and their composites are expectedto make a significant impact on the advancement of the energy conversionand storage technologies.2-hybridizedcarbon atoms, attracts worldwide research interest due to its exceptionalphysical properties.25 Graphene finds largepractical applications in microelectronics, optoelectronics, and energystorage.26 Chemical vapor deposition (CVD)is recognized as the most suitable synthesis route to get high quality graphene.27Graphene, a 2D single-layer sheet of sp3H6N6) and g-C3N4/graphene nanocomposites were obtained by thermalreduction at different graphene/g-C3N4 ratios.After structural and optical characterizations of the nanocomposites,the best nanocomposite composition was determined and it was usedas a photocatalyst in the photo-assisted charging of the Li-ion oxygenbattery. The improved photocatalytic activity was obtained in theg-C3N4/graphene nanocomposites since the highquality graphene brought about an increase in both the surface areaand electrical conductivity of g-C3N4. Additionally,the presence of graphene caused a redshift and narrowing of the bandgap slightly in the semiconductor nanocomposites.In this work, following the efforts on the development ofthe effectivephotocatalyst for the Li-ion oxygen battery, a novel nanocompositewas synthesized. Initially, the few layer graphene films were synthesizedon the copper substrate by CVD. Then, the graphene films were mixedwith melamine  cathodes (oxygen electrodes) were reportedin our previous work.Figure S1 on the Cu foil substrate . After the synthesis process,the Cu substrate was dissolved in 50% HCl solution including 0.5 MFeCl3 and the graphene films were collected in high purityethanol. Since the graphene films were covering the Cu foil substratesurface continuously without any damage, the surface area of the graphenefilm was assumed to be equal to the surface area of the Cu foil substrate.For the characterizations of the graphene films, the Cu foil was coatedwith the poly methyl methacrylate (PMMA) on the spin coater and thenthe copper substrate was dissolved. PMMA was also cleaned with acetone/isopropanolcombinations after the coated graphene film was transferred to eitherSiO2/Si or transmission electron microscopy (TEM) grit.Graphene wassynthesized by CVD according to the procedure provided in –1) and heatedup to 550 °C at a rate of 3 °C min–1 andthen kept at this temperature for 3 h. Subsequently, g-C3N4/graphene nanocomposites were collected after coolingto R.T. Nanocomposite compositions were determined according to theratio of graphene surface area to g-C3N4 weight(cm2 graphene/mg g-C3N4).In order to prepare nanocomposites, melamine and graphene weremixed in ethanol at 50 °C until all the ethanol evaporates. Aftercomplete drying, melamine and graphene were put into a crucible (30mL) under continuous Ar flow (1.2 L min2.2–2)by a spin coater and then drying at 100 °C for 12 h in a vacuum-desiccator.The photoelectrochemical measurements were made in a conventionalthree-electrode cell with a platinum wire as the auxiliary electrodeand an Ag/AgCl (saturated KCl) as the reference electrode on a GamryReference 3000 workstation in a spectral cell containing 0.1 M KClbuffered by 0.1 M K2HPO4 to pH 7. The photocurrentswere measured by the linear sweep voltammetry technique, and the semiconductorloading was 0.05 mg cm–2. A solar simulator  was used as the light source. The semiconductor loadingwas 0.8 mg cm–2 for the Mott–Schottky measurements.The working electrode was prepared by loadingthe nanocomposite on ITO glass was used as a separator. The oxygen electrode was prepared by mixingthe porous Pd@rGO/Super P carbon black/PVDF (80:10:10 wt %) in NMP,and then, the slurry was coated onto one side of 16 mm diameter GDL(TGP-H-060) with a loading rate of 0.1 mg cm–2.The semiconductor nanocomposite was coated on the other side of GDLwith a loading rate of 0.05 mg cm–2 as a photoelectrode.Before the battery assembly, the electrodes were dried in a vacuumoven at 100 °C overnight. 0.5 M LiClO4 and 0.05 MLiI dissolved in TEGDME were used as an electrolyte for photo-assistedcharging. LiI was excluded if charging was conducted without illumination.The discharge and charge tests were performed galvanostatically andthe discharge cutoff potential was 2.0 VLi+/Li. The chargecutoff potentials were 3.6 VLi+/Li and 4.2 VLi+/Li for the photoassisted and dark charging, respectively. The currentdensities changed between 10 mA g–1 (10–3 mA cm–2) and 500 mA g–1 (5 ×10–2 mA cm–2).Photo-assisted charging of the Li-ion oxygen battery was carriedout by a homemade cell in an oxygen cabin, which had 1 bar positiveoxygen pressure during the measurements, as shown in our previouswork.2.3–1. The morphologies were examined with a ZEISSUltraplus scanning electron microscope. FTIR measurements were conductedby a PerkinElmer Spectrum Two. The graphene film morphology was characterizedusing a JEOL JEM 2010F transmission electron microscope running at200 kV and atomic force microscopy . UV/vis spectrawere recorded by Cary 5000 UV/vis/NIR spectrometer with a diffusereflectance accessory between 200 and 800 nm. The Raman analysis wascarried out by Raman spectroscopy (RENISHAW RAMAN inVia microscope)with an excitation wavelength of 532 nm.X-raydiffraction (XRD) analyses were performed on a PANalytical Empyreandiffractometer with Cu Kα radiation at a scanning rate of 2°min33.1Figure S2a. Two main peaks can be assigned inthe Raman spectrum. The G (∼1582 cm–1) and2D (∼2694 cm–1) bands are attributed to thesp2 hybridizations of the C atoms.28 The 2D band is sensitive to the number of layers of graphene films.28 The 2D/G intensity ratio is 3.2 in Figure S2a, in which the synthesized graphenelooks to have only a few layers. The absence of the D band in Figure S2a indicates that the graphene filmsare synthesized without any defect. The scanning electron microscopy(SEM) and TEM images of the synthesized graphene on the TEM grit arepresented in Figure S2b,c, respectively.These images reflect the typical few-layer graphene morphology. Itis also understood from the images that there are occasional wrinklesand overlaps. Similar characteristics of the graphene film can alsobe observed in the AFM image in Figure S2d.The normalizedRaman spectra from the synthesized graphene film are provided in 3N4/graphenenanocomposites are determined according to the total surface areaof graphene (cm2) per weight of g-C3N4 (mg) present in the nanocomposite structure. The nanocompositeswith three different compositions are synthesized: 1 cm2 graphene/mg g-C3N4, 2 cm2 graphene/mgg-C3N4, and 3 cm2 graphene/mg g-C3N4. The structural changes in the synthesized nanocompositesare identified by FTIR spectra , as shown in 3N4 andnanocomposites (novel ones) are shown by blue and red dashed lines,respectively, in –1 are associated with N=H stretching  in pure g-C3N4.29 Spectrum peaks located between 1200 and 1650cm–1 are due to the stretching modes of CN heterocycles.29 Peaks located in the range change from 735 to806 cm–1 and at 885 cm–1 are attributedto the triazine ring stretching and N–H band deformation modes,respectively.29 The synthesized nanocompositeshave all of the characteristic peaks of pure g-C3N4. Novel peaks (marked by red dashed lines) in nanocompositeslocated in the range between 2880 and 2950 cm–1 (mediumstrength) and at 660 cm–1 (strong) can be attributedto the C–H stretching vibrations probably due to the interactionof graphene with the residual amino groups or absorbed water, andthe C=C bond bending vibrations, respectively, in 3N4 and graphene duringthe decomposition of melamine to g-C3N4 at 550°C as reported previously.7The composition of the g-C3N4 and g-C3N4/graphene nanocomposites. A strong characteristic(002) peak at 27.6° in the pure g-C3N4 patternis associated with the layered structure.17 The peak at around 13.2° (100) in the pure g-C3N4 pattern in s-triazine units.28 All the nanocompositeshave almost the same characteristic peaks as those of pure g-C3N4 in 2 graphene/mgg-C3N4, 2 cm2 graphene/mg g-C3N4, and 3 cm2 graphene/mg g-C3N4 nanocomposites are provided in Figure S3. Morphologies of the nanocomposites are very similarto that of pure g-C3N4, which has a characteristicslate-like stacked lamellar microstructure.7 No clear change is observed in the nanocomposite morphologies sincethe amount of CVD graphene is considerably small in the nanocompositestructure.The morphologies of thesynthesized 1 cm3.23N4 by the linear sweep voltammetry techniques,as shown in 3N4.The photoanodiccurrents, via on–off cycles under visible-light irradiation,are obtained for all the synthesized nanocomposites and pure g-C3N4 and nanocomposites are given in 3N4 is 485 nm and it increases slightly to 490, 500, and510 nm for 1 cm2 graphene/mg g-C3N4, 2 cm2 graphene/mg g-C3N4, and3 cm2 graphene/mg g-C3N4, respectively.The optical band gaps (Eg) can be obtainedby the Tauc plot,30 as in 3N4, 1 cm2 graphene/mgg-C3N4, 2 cm2 graphene/mg g-C3N4, and 3 cm2 graphene/mg g-C3N4, respectively. It was reported previously that theincorporation of the nanocarbons to g-C3N4 causesa redshift in the absorption band edges of g-C3N4 and thus the absorption band edges shift to the higher wavelengthsand then the corresponding optical band gaps are narrow.7 The redshift in the nanocomposites is attributedto the formation of a novel chemical bonding during the synthesisof the nanocomposites.73N4 nanocomposites.The UV–vis diffuse reflectance spectra of pure g-C3–/I– shuttle for the photo-assistedcharging. If the flat band potential is assumed to be approximatelyequal to the CB edge potential, Mott–Schottky plots can providethe CB edge potential of the photocatalysts as in The VB edge potential of the photocatalysts directly determinesthe photo-oxidation power which is critical to drive I3.3– ions are oxidized to I3– ions by the photoexcited holes of the photocatalystas in –/I3– couple  and spontaneouslyoxidize low-conducting Li2O2 to Li+ ions and O2  and the overall result is thatthe charge potential of the Li-ion oxygen battery is compensated bythe generated photovoltage.1 Thermodynamically,the reduction extension in the charging potential of the Li-ion oxygenbattery is directly related to the level of CB edge potential thatthe lower the CB edge potential, the lower the charging potential.2 Despite the thermodynamic conveniences of allthe tabulated semiconductors in 2 graphene/mg g-C3N4 nanocomposite has the highest photoanodic currents in 3N4 structureimproves the light-harvesting capability of the g-C3N4.If the photoexcited electrons of thephotocatalyst are efficientlyseparated from the photoexcited holes, then they flow to the anodeto reduce the Li3N4 and 3 cm2 graphene/mgg-C3N4 nanocomposite photoelectrodes are preparedand 1 h-long charge curves at various current densities are obtainedas in Li+/Li at 10 mAg–1 (0.001 mA cm–2) in Li+/Li) at 50mA g–1 (0.005 mA cm–2) in –1 (0.01 mA cm–2) in 3N4 photoelectrode passes above the discharge curvewhile that in the presence of 3 cm2 graphene/mg g-C3N4 photoelectrode still in the scale range of thedischarge curve. Further increases in the current densities to 200mA g–1 (0.02 mA cm–2) and 500mA g–1 (0.05 mA cm–2), in 3N4  for 50 cycles under the photoassistanceas in –/I3– couple (3.586 VLi+/Li) acts as a cutoff potential, which is slightly less than the theoreticalpotential in the used electrolyte, for the charging, and when thecharge curve reaches this potential, the charging stops. In the presenceof pure g-C3N4 as a photocatalyst, the chargecurve reaches the cutoff potential at around the 40th cycle, and asthe cycle number increases further, the discharge capacity decreasesbelow 2500 mA h g–1 (0.25 mA h cm–2). It is reduced to 1780 mA h g–1 (0.178 mA h cm–2) at the 50th cycle. In the presence of the 3 cm2 graphene/mg g-C3N4 nanocomposite asa photocatalyst, however, the charge curves are still below the cutoffpotential and thus there is no reduction in the discharge capacityat the 50th cycle in 3N4 structure causethe Li-ion oxygen battery to have improved performance under the illuminatedconditions.The photocatalytic efficienciesof both g-C–/I3– couple (3.586 VLi+/Li) to drive redox reaction shuttling, and the CB edgepotential of the photocatalyst should be as low as possible to suppressthe charge potential. This work shows that in addition to the thermodynamicconstraints, increased conductivity, surface area, and light absorptioncapability are required for the photocatalyst to effectively reducethe charge potential under photoassistance, especially at the highcurrent densities.Effective photo-assisted charging requires a photocatalystwithimproved properties. Thermodynamically, the VB edge potential of thephotocatalyst should be greater than the redox potential of the I43N4/graphene, whichwas initially synthesized by CVD, nanocomposites were synthesizedby thermal reduction as the photocatalysts for the photo-assistedcharging of the Li-ion oxygen battery. Optical characterizations showedthat the presence of graphene reduced the optical band gaps of thenanocomposites and improved the visible light utilization of g-C3N4. The positive contribution of the graphene filmsto the photocatalytic efficiency of g-C3N4 wasalso observed in the photo-assisted charging tests of the Li-ion oxygenbattery that the charging potential was reduced considerably evenat the high charging current densities.In conclusion,the g-C


In this study, graphite, graphene, and hydrophilic-treated graphene electrodes were evaluated in a dual-chamber microbial fuel cell (DC-MFC). Free-oxygen conditions were promoted in anodic and cathodic chambers. Hydrochloric acid at 0.1 M and pH 1.1 was used as a catholyte, in addition to deionized water in the cathodic chamber. Domestic wastewater was used as a substrate, and a DuPontTM Nafion 117 membrane was used as a proton exchange membrane. The maximum power density of 32.07 mW·m Domestic wastewater contains a high level of organic compounds that store chemical energy, and with proper treatment, this energy can be harnessed . Microbirm water . Energy Some strategies to maximize the benefits of DC-MFCs focus on user-controllable parameters such as electrode materials, substrate, catholyte, and device scale ,5,6. TheGraphene is a material that has recently been used as anode and cathode in MFCs. Since its isolation in 2004, it has stood out for its unique properties. Graphene can be produced from graphite as the raw material, and then it is considered a low-cost material . Its structure is a two-dimensional (2D) cohesion of carbon atoms, with a crystalline arrangement similar to a honeycomb. It can be found in nature in the form of powder or flakes . This chctively) ,10,11, tThe catholyte is another user-manipulable parameter, which influences the electron transfer, the participation of different final electron acceptors, and the reduction potential. Oxygen is the most widely used electron acceptor due to its unlimited availability and high standard redox potential. However, it is also a limiting factor in the performance of MFCs because it can have low oxygen reduction kinetics. To address this limitation, different catholytes with a higher redox potential that facilitate the availability of other electron acceptors have been used. Examples of these catholytes are ferricyanide, sodium hypochlorite (NaOCl), sodium bromate, and hydrochloric acid (HCl) ,13,14,15To date, significant progress has been made in MFCs, however, there are still gaps to be addressed in order to improve energy efficiency and simultaneously the capacity to treat wastewater. Therefore, the objective of this work is to evaluate different carbon-based materials and the use of HCl acid as a catholyte to enhance the capacity of DC-MFCs to generate electricity and treat domestic wastewater and highlight the importance of identifying the optimal operating parameters, which directly influence MFC performance. For this purpose, three different carbon-based materials, graphite, graphene, and hydrophilic-treated graphene (HTG), were evaluated as electrodes in DC-MFCs. Additionally, HCl was evaluated as a catholyte, aiming to elucidate its influence on the catalytic properties of the cathodic chamber and to improve the degradation of organic matter in domestic wastewater. Furthermore, anoxic conditions were promoted in the anodic and cathodic chambers. Simultaneously, a control was run using the same electrode materials and under typical MFC operating conditions (deionized water in the cathodic chamber).The carbon-based materials used as electrodes were characterized by scanning electron microscopy (SEM) and Zeiss Evo ma24 energy dispersive X-ray spectroscopy (EDS) with a Bruker xflash6|10 detector, . The specific surface area and pore structure of the electrode materials were obtained with a Quantachrome Autosorb iQ tpx  by measuring the nitrogen . The membrane was activated before being used following the procedure described by Lavorante et al. . J. J−1 CODctrolyte  also repIn addition, the HTG electrodes exhibited the maximum power output in DC-MFC, compared to the untreated graphene, and graphite electrodes. This can be attributed to the fact that the Ti depositions on the HTG participate as optimizers of graphene features including electrical conductivity and the surface area of the material, as confirmed in the previous Few studies have reported the use of a low-pH environment in MFCs: Jannelli et al.  evaluatei et al.  evaluateutral pH ,49,50. THence, the use of HTG or graphene as electrodes, both operated under acidic conditions (HCl as catholyte), stand out as the scenarios that best favor energy production in DC-MFCs. Regarding the efficiencies obtained in scenarios 2 and 3 to degrade the organic matter in the wastewater, it is suggested to analyze new scenarios with a lower concentration of HCl as the catholyte. The aim is to take advantage of the benefits to produce electrical energy, and at the same time decrease the possible adverse effects on the electrogenic microorganisms and increase the capacity to oxidize the substrate.This study evaluated three electrode materials ) in DC-MFC in the capacity of treating 3.40 L of domestic wastewater and using HCl  as a catholyte, and deionized water in the cathodic chamber. A comparison of electrode materials, taking into account both their ability to produce energy and to treat wastewater, ranked them from highest to lowest performance in the following order: HTG, graphene, and graphite using HCl as catholyte. According to the characterization of the HTG material, a larger surface area, large pore volume, and higher electrical conductivity were observed, which can be attributed to the Ti deposition found on its surface. These properties in the HTG promoted the availability of active sites and, in turn, the availability of improved adhesion of the electrogenic microorganisms, resulting in the better overall performance of the DC-MFCs. In the scenario with HTG electrodes, HCl as catholyte, and an external resistance of 100, the maximum power density of 32.07 mW·m