Integrated photonic circuits (PICs) have seen an explosionin interest,through to commercialization in the past decade. Most PICs rely onsharp resonances to modulate, steer, and multiplex signals. However,the spectral characteristics of high-quality resonances are highlysensitive to small variations in fabrication and material constants,which limits their applicability. Active tuning mechanisms are commonlyemployed to account for such deviations, consuming energy and occupyingvaluable chip real estate. Readily employable, accurate, and highlyscalable mechanisms to tailor the modal properties of photonic integratedcircuits are urgently required. Here, we present an elegant and powerfulsolution to achieve this in a scalable manner during the semiconductorfabrication process using existing lithography tools: by exploitingthe volume shrinkage exhibited by certain polymers to permanentlymodulate the waveguide’s effective index. This technique enablesbroadband and lossless tuning with immediate applicability in wide-rangingapplications in optical computing, telecommunications, and free-spaceoptics. Resonances in photonic nanostructuressuch as microring resonators form the backbone for many of these applicationsand provide high sensitivity in their operation.18 However, thehigh quality factor resonances employed come at the cost of stringentdesign tolerances which are not typically satisfied in their fabrication.19 Active electrical components such as thermo-optic21 or electro-optic23 phase shifters are thereforecommonly employed; these are, however, power hungry and occupy valuablechip real estate.Interest in optical technologieshas experienced an extraordinary surge in recent decades due to themultifaceted functionality that optical signals enable. A proliferationof both integrated and free-space components have emerged capitalizingon the speed, bandwidth, and functionality of photonics to realizetechnologies ranging from displays27 or alternatively using materials which demonstrate permanent geometricalor structural changes based on external programming30 between binaryor multiple states. This can be achieved using electrical, optical,or thermal stimuli which can permanently modify the atomic arrangementin the material or induce permanent chemical changes.18One route to addressing this significant challengeis through theuse of materials which show a permanent modulation of their opticalproperties31 By employing an inexpensive, fab-compatible,and widely available polymer, poly(methyl methacrylate) (PMMA), asan overcladding in photonic circuits, we demonstrate that we can permanentlymodify the modal properties of the waveguides with excellent control.We demonstrate that this method has considerable strengths in scalability,reproducibility, and compatibility with industrial processes, whichmake it highly applicable to standard foundry wafer processing. Ourexperiments shed light on the mechanism of this modification, andusing this we are able to accurately predict the propagation characteristicsof PMMA-clad waveguides.33 Our technique demonstrateshigh-resolution trimming of single- and multi-resonator photonic circuitsin excess of 1 nm with picometer precision.In this work, we exploit the property of certainpolymers to undergochain scission and crosslinking upon exposure to energetic beams—bothultraviolet (UV) and electron beams. We unequivocally demonstratethat chain scission and crosslinking induce a volumetric change inthe polymer film, rather than a modification in its refractive index.34 Thisprocess is known to cause the outgassing of volatile species , which locally reduces the volumeof the polymer.35 Localized changes intopography can then be observed directly by measuring the topographyof the film using an atomic force microscope (AFM) (31H) of the stack with increasing exposuredose as measured by AFM for different polymer thicknesses. The initialthickness of the polymer here is controlled by changing the initialconcentration of the polymer during spin coating. A comparison betweenthe height changes and color changes with increasing dose is shownin 2  1c or indpe (AFM) 1b.31Figun) of 1.5 and near zerochanges in the extinction coefficient (k) . We have thus proved that any opticaleffects are dominated by the structural changes in the polymer ratherthan modifications in its dielectric function.To decouple any optical changes which could besimultaneously occurringin the film, we directly measure the optical parameters of exposedfilms by ellipsometry. As evidenced in H/H = 10% the change in effective index between the two states showsa maximum at an initial thickness of 50 nm for silicon and 100 nmfor silicon nitride based waveguides. This is attributed to the highermode confinement in Si compared to SiN.We then exploit this capability by modulating themodal characteristicsof photonic integrated circuits. In order to determine the claddingthickness which produces the strongest modulation in the effectiveindex of the propagating mode, we perform mode simulations on silicon(SOI) and silicon nitride (SiN) PICs for varying polymer thicknesses.Here, the electric field of the optical mode of the waveguide decaysexponentially throughout the polymer cladding and an optimal balancebetween the interaction volume and the distance to the waveguide issought to maximize the effect of the polymer shrinkage. This is illustratedin Neff in Neff = 1.85 × 10–3.In 2 substrate index values. Upon coating with a layer of PMMA, the resonanceof the ring is measured to red-shift to 1551 nm due to the presenceof the polymer cladding. Figure S1). This isachieved using a uniform coating of the chip in its entirety and aflood exposure to UV light.We proceed to show that theinduced change in effective index canbe employed to accurately and precisely tune the spectrum of an add-dropring resonator. Figure S3) and subsequently measuring each resonator via drop ports1, 2, and 3. The progressive trimming is shown in Figure S2.We proceed to demonstrate the scalabilityof the technique andaddressability of multi-component photonic circuits by individuallytrimming the resonance wavelength of three cascaded ring resonators. 9 scale,andmapped to the height changes (ΔH) reportedin 2 to produce a replica of the originaltopography at a 1:109 scale. The topography of the fabricatedreplica is shown in the AFM micrograph of Figures S4 and S5.It has been demonstrated that high-qualityresonances in integratedphotonics can be modulated by locally modifying the height of a polymerovercladding which in effect utlizes a uniform modulation of the structureout of plane. However, as the polymer layer also affords nanoscalecontrol in plane, we proceed to demonstrate this capability by structuringthe polymer film in three dimensions for the production of complexnanostructures which can be employed in photonics and beyond. Here,by precisely modulating the exposure dose in space, the topographyof the polymer can be modulated with sub-nanometer precision. Thetopography produced can then be used directly for three-dimensionalmodifications of the optical properties of micro- and nanostructures and can be even employedas a fabrication mold for further processing. To demonstrate thiscapability, we reproduced the complex 3D landscape of the Greek islandHydra shown in We have demonstrated the implementationof a scalable, high-resolution,and lossless trimming mechanism for photonic circuits using a single-shotcontrolled exposure of the photosensitive polymer PMMA. In contrastto previous works attributing modifications in the optical mode propagationto a modulation in the refractive index of the material, we show thatthe refractive index remains largely unchanged while the topographyof the film is modified. By understanding and modeling such changes,we show a single-shot linear tuning range of over 1 nm, with picometerprecision. We further demonstrate individual trimming of cascadedring resonators to produce equally spaced resonances without incurringadditional optical losses, which is highly desired in large-scaleintegrated photonic circuits. Owing to the ultrahigh out-of-planeresolution afforded by this method, we extend this work to the patterningof complex three-dimensional structures with high resolution and fidelity,showing the potential of this technique in a broad range of applicationsranging from metasurfaces and free-space optics to integrated nanophotonics.2 plasma for 1 min. The samples were subsequently spin-coated withdifferent thicknesses of PMMA and baked at 180 °C for 10 minto remove all solvents from the thin film.Solutions of PMMA 495k in anisolewere prepared in concentrations ranging from 8% (A8) to 2% (A2). Intrinsicallydoped silicon wafers were used for all samples with the exceptionof samples including photonic integrated circuits, which relied onthe silicon nitride on insulator (SiN) platform. Samples were cleanedin acetone and IPA, dried using nitrogen, subsequently baked at 150°C to remove water condensation, and treated with O3 dry chemical etchingto create the waveguides, grating couplers, and ring resonators. Finallythe resist was removed and the wafers were treated according to theprocedure outlined in the previous section before being exposed toUV radiation using a SUSS mask aligner with a power of 8.49 mW/cm2 measured at 240 nm wavelengths.Siliconnitride on insulator wafers with a 330 nm silicon nitride layer werepurchased from Rogue Valley Microdevices and were cleaned accordingto the procedure outlined above. Samples were subsequently coatedwith CSAR65 positive EBL resist and patterned in a Jeol JBX5500 system.The samples were finally etched by CHF


In this issue of Kidney360, Li and colleagues report a combination of transcriptomics, metabolomics, and targeted assays interrogating metabolism in a subtotal nephrectomy (STN) murine model of CKD.2CKD is characterized by the gradual loss of glomerular filtration function over time. Yet, emerging evidence suggests that CKD is accompanied by intrarenal impairments that extend far beyond filtration. One area that has received substantial attention is the profound alteration in intrarenal metabolism during CKD. These metabolic disturbances may contribute to disease progression.μl/min). Bulk whole-transcriptome analysis revealed 872 genes displaying significant differential expression, with 470 genes being overexpressed and 402 genes being underexpressed in STN kidneys compared with sham kidneys. Significant alterations were observed in the regulation of mitochondrial function, fatty acid metabolism, and glucose metabolism.The authors focused on a time point 4 weeks after STN when GFR had declined by more than 60% of sham controls (approximately 400–150 α), reflecting mitochondrial biogenesis, were both increased in STN kidneys. The increase in Pgc1α is notable because this gene's induction has been shown in several studies to promote the health of the renal tubule in the setting of acute stress or inducers of fibrosis.35 These results suggest a model in which the remnant tubule mass increases its mitochondrial mass to respond to the higher solute load arising from increased single-nephron GFR.6The most significantly different biological pathway was oxidative phosphorylation, within which most of the genes were upregulated in STN kidneys. Furthermore, transcripts for two major substrate utilization pathways used for energy generation—fatty acid oxidation (FAO) and glycolysis—were upregulated in the STN kidneys compared with sham kidneys. In fact, the mRNA for the rate-limiting enzymes in FAO, carnitine palmitoyltransferase I and II, as well as the mRNA levels of several glycolytic enzymes, including hexokinases 1 and 2, phosphofructokinase, and pyruvate kinase, were significantly increased in STN kidneys compared with sham kidneys. The mitochondrial copy number, reflecting mitochondrial content, and the expression of peroxisome proliferator-activated receptor gamma coactivator1 alpha , which catalyzes the conversion of pyruvate to acetyl CoA, was revealed to be intact, but the protein expression of the PDH E1 subunit and the activity of PDH phosphatase, which activates PDH, were both identified as reduced in STN kidneys.α—in STN kidneys' proximal tubules with a concomitant increase in glycolytic flux.Making the metabolic consequences of nephron mass reduction even more complex to discern, Li and colleagues found that functional assays in freshly isolated proximal tubules displayed a consistent profile of mitochondrial impairment. Specifically, mitochondrial basal and maximum oxygen consumption rates and respiratory control ratio, coupling efficiency and ATP-linked respiration to maximal respiration, were all decreased in proximal tubules isolated from STN kidneys compared with sham control counterparts. Conversely, measures of glycolysis in this same experimental setup revealed either increased or unchanged flux in proximal tubules isolated from STN kidneys compared with controls. Together, the flux assays implicated decreased mitochondrial function—despite the elevated oxidative phosphorylation signature in whole-kidney RNA sequencing, increased mitochondrial DNA copy number, and induction of Pgc1e.g., a shift to aerobic glycolysis in the proximal tubule swamped out by a shift to mitochondrial metabolism in many other compartments of the STN kidney. Finally, as the authors caution, metabolomics offers a static snapshot of intermediary metabolism reflecting the balance of anabolic and catabolic processes, whereas flux studies help address the actual flow of substrates.As the authors note, some of this discrepancy could relate to substrate utilization: For example, the per-cell mitochondrial mass may indeed be elevated in the proximal tubule after STN, but defects in substrate import or key steps in substrate conversion to fuel might impair actual oxidative phosphorylation in mitochondria. Although technical issues could impair the fidelity of functional assays, freshly isolated tubules should maintain the core metabolic functions they possessed in vivo. Another possibility is that the whole-kidney RNA sequencing and metabolomics reflect compensatory changes against contrary events in the proximal tubule, 7 Nonetheless, Li and colleagues have provided, to our knowledge, the first extensive description of metabolic alterations in the mouse STN setting, a model that addresses the reduced nephron mass of CKD.8 Glycolysis, FAO, and gluconeogenic pathways were found to be transcriptionally upregulated by Li et al. 4 weeks after STN surgery. The upregulation of glycolysis in CKD is consistent with the existing literature, in contrast to FAO and gluconeogenesis, which are typically described as downregulated9 (Figure 5 Conversely, inhibition of glucose import into the proximal tubule by sodium glucose linked cotransporter inhibitors confers extraordinary renoprotection against a wide range of CKD etiologies.10Several previous studies have emphasized the importance of understanding metabolic adaptations in CKD.9 Figure . In prox11These results highlight the complexity of metabolic regulation in progressive kidney disease and the need for the type of complementary approaches undertaken by Li and colleagues. Further spatial resolution of transcriptomic and metabolic changes, extended through multiple time points in the transition from acute injury to chronic fibrosis and perhaps even across different experimental models, may illuminate the complex spatiotemporal regulation of metabolism and novel opportunities to develop noninvasive health and disease markers or even metabolically inspired treatments. A recent study by Wang and colleagues highlights the promise of coregistered spatial transcriptomics and metabolomics to open such new avenues in kidney biology.To conclude, Li and colleagues report an extensive metabolic characterization of a model of reduced nephron mass. Their results highlight a shift away from mitochondrial oxidative metabolism and toward glycolysis in the proximal tubule, despite the increased solute load encountered by remnant nephrons in this model. Further research should further unravel the dynamics and regional heterogeneity of metabolic alterations in CKD. Given the unexpected and outsized success of sodium glucose linked cotransporter inhibitors against CKD progression, there is an urgent need to advance our knowledge of metabolic processes in kidney health and disease.


Autophagy is an explicit cellular process to deliver dissimilar cytoplasmic misfolded proteins, lipids and damaged organelles to the lysosomes for degradation and elimination. The mechanistic target of rapamycin (mTOR) is the main negative regulator of autophagy. The mTOR pathway is involved in regulating neurogenesis, synaptic plasticity, neuronal development and excitability. Exaggerated mTOR activity is associated with the development of temporal lobe epilepsy, genetic and acquired epilepsy, and experimental epilepsy. In particular, mTOR complex 1 (mTORC1) is mainly involved in epileptogenesis. The investigation of autophagy’s involvement in epilepsy has recently been conducted, focusing on the critical role of rapamycin, an autophagy inducer, in reducing the severity of induced seizures in animal model studies. The induction of autophagy could be an innovative therapeutic strategy in managing epilepsy. Despite the protective role of autophagy against epileptogenesis and epilepsy, its role in status epilepticus (SE) is perplexing and might be beneficial or detrimental. Therefore, the present review aims to revise the possible role of autophagy in epilepsy. Epilepsy is defined as a condition characterized by recurrent two or more epileptic seizures, unprovoked by any immediate identified cause   and Beclin-1 (Atg6)  through activation of IGF receptors (IGFRs) promote the activity of tyrosine kinase and Aκt leading to activation of the mTOR pathway and inhibition of autophagy  is a second messenger that induces the release of Ca2+ from the endoplasmic reticulum (ER). The IP3 receptor (IP3R) was discovered as a developmentally regulated glycol-phosphoprotein, P400 . IRBIT is a pseudo-ligand for IP3 that regulates the frequency and amplitude of Ca2+ oscillations through IP3R , a nicotinamide adenine dinucleotide-dependent deacetylase, is a member of the evolutionarily highly conserved superprotein family, which is located in the nucleus and cytoplasm. It can deacetylate protein substrates in various signal transduction pathways to regulate gene expression, cell apoptosis, and senescence, and participate in the process of neuroprotection, energy metabolism, inflammation and the oxidative stress response in living organisms  is a threonine/serine kinase enzyme that regulates different cellular pathways. GSK3 refers to two paralogs that are commonly referred to as isoforms, GSK3α and GSK3β  is a central regulator of energy homeostasis, which coordinates metabolic pathways and thus balances nutrient supply with energy demand  isoenzymes including PLD1 and PLD1 have basic cell functions such as vesicular trafficking as well as in brain development. They hydrolyzed phosphatidylcholine to generate phosphatidic acid and free choline  and neuronal apoptosis  is primarily responsible for releasing free Taken together, these judgments highlighted that dysregulation of autophagy signaling is involved in epilepsy Fig. . However3 levels. This novel pharmacologic strategy for autophagy induction is independent of mTOR and may help treatment of various neurodegenerative diseases  (Varrassi et al. Metformin is an insulin-sensitizing drug used in the management of type 2 diabetes (Al-Kuraishy et al. Furthermore, metformin increases the neuroprotective progranulin and anti-inflammatory cytokines in rats with experimental temporal lobe epilepsy (Vazifehkhah et al. Furthermore, some types of epilepsy are associated with the up-regulation of the mTOR pathway, and inhibition of this pathway by AMPK activators such as metformin can reduce seizure frequency and severity (Kim et al. Regarding the safety profile of autophagy activators in epilepsy, both lithium and rapamycin are not appropriate for long-term due to systemic adverse effects such as diabetes inspidus and bone marrow depression caused by lithium and rapamycin respectively (Livingstone and Rampes In sum, autophagy inducers play a critical role in reducing seizure frequency and severity and could be adjuvant treatment in the management of epilepsy Fig. .Epilepsy is a neurological disease characterized by repeated seizures. AEDs control epilepsy in about 69%, and one-third of epileptic patients are not controlled by AEDs called refractory epilepsy. Dysregulation of autophagy is intricate in the pathogenesis of epilepsy. Autophagy prevents the development and progression of epilepsy through regulating the balance between inhibitory GABA and excitatory glutamate. Induction of autophagy and autophagy-related proteins like Atg7, LC3, and Beclin-1 might be an innovative therapeutic strategy in managing epilepsy. Despite the protective role of autophagy against epilepsy, though its role in SE is perplexing and might be a double-edged sword, may be detrimental or harmful. Autophagy activators such as rapamycin, metformin and ibuprofen play a critical role in reducing seizure frequency and severity and could be adjuvant treatments in the management of epilepsy. Therefore, autophagy activators could be effective in the management of epilepsy and can be used as adjuvant treatments in the management of resistance epilepsy. Additional preclinical and clinical studies are recommended in this regard.


Breast cancer is a heterogeneous disease for which effective treatment depends on correct categorization of its molecular subtype. For the last several decades this determination has relied on hormone receptor status for estrogen, progesterone and HER2. More recently, gene expression data have been generated that further stratify both receptor-positive and receptor-negative cancers. The fatty acid-activating enzyme, ACSL4, has been demonstrated to play a role in the malignant phenotype of a variety of cancers, including breast. This lipid metabolic enzyme is differentially expressed as a function of subtype in breast tumors, with highest expression observed in the mesenchymal (claudin low) and basal-like subtypes. Here we review data that support the potential of utilizing ACSL4 status as both a biomarker of molecular subtype and a predictor of response to a variety of targeted and non-targeted treatment regimens. Based on these findings, we suggest 3 expanded roles for ACSL4: 1. as a biomarker for classification of breast cancer subtypes; 2. as a predictor of sensitivity to hormone-based and certain other therapies; and 3. as a target for the development of new treatment modalities. ACSL4 is one of five mammalian enzyme isoforms responsible for activation (thioesterification) of long-chain fatty acids as a prerequisite to their further utilization in lipid biosynthetic and fatty acid oxidative pathways . ACSL4 iACSL4 activity has been implicated to play a role in both normal and abnormal physiology. Evidence to date suggests that ACSL4 functions in a variety of normal developmental and cell biological processes, including neuronal differentiation , germ liA role for long-chain fatty acid activating enzymes in supporting the malignant phenotype was first suggested in 2000 when Cao et al.  assertedBreast cancer is a heterologous disease initially subcategorized as a function of receptor expression with respect to ER, progesterone receptor (PR) and human epidermal growth factor 2 (HER2) receptors. Cancers lacking all three receptors are termed triple negative breast cancer (TNBC). TNBC exhibits a more aggressive phenotype than receptor positive cancer (RPBC) and currently lacks targeted treatment options. This receptor-based characterization has been further refined by means of mRNA expression analyses, with receptor-positive cancers comprising mainly the luminal A, luminal B and HER2-enriched subcategories , and mosObservational studies have demonstrated that ACSL4 mRNA expression is inversely correlated with ER, AR and HER2 expression in both breast cancer cell lines and tumor samples, and is most highly expressed in TNBCs that fall into the category of claudin-low and basal-like cancers . In partThere are limited proteomic data with respect to breast cancer subtypes; however, these data also support the conclusion that ACSL4 is differentially overexpressed in basal-like breast cancers. A study comparing protein expression in luminal B versus basal-like breast cancer samples clearly indicates that ACSL4 protein is more highly expressed in the basal-like subset . A more in vitro and in vivo; and conversely, silencing of ER expression in MCF7 cells induces expression of ACSL4 in vitro imidazotriazin-2yl)acetamide) that blocks cell proliferation and tumor growth in both breast and prostate cancer models as well as sensitizing tumor cells to chemotherapeutic and hormonal treatment . This coTargeting ACSL4 in cancer treatment, whether it involves forced expression or inhibition, will most likely not comprise a lone therapy but will more likely function as part of a combined therapy. First, it is clear that cells, including malignant cells, are not completely dependent on ACSL4 for fatty acid activation. A number of both normal and cancerous cell types do not express ACSL4 and rely on the alternate isoforms  to carry out activation functions. Preclinical data clearly demonstrate that effects of ACSL4 on proliferation, migration and invasion of cancer cells are incremental rather than absolute , 25, 52. as mTOR  and lipoBreast cancers comprise a heterogeneous disease that has routinely been categorized by receptor status with respect to estrogen, progesterone, HER2 and more recently androgen. Cancers lacking the first three receptors are classified as triple negative breast cancer (TNBC), while those lacking all four, quadruple negative breast cancer (QNBC). Treatments have been developed which specifically target these receptors; however, receptor-negative breast cancers are more aggressive and, to date, lack targeted therapies. Recently, TNBC has been subcategorized into four subtypes based on gene expression data: luminal androgen receptor (LAR), mesenchymal (MES), basal-like immune-suppressed (BLIS) and basal-like immune-activated (BLIA) . The datin vitro and in vivo. As such, ACSL4 presents a possible target for treatment, and indeed the search for specific inhibitors is underway, with one promising candidate recently reported. Furthermore, it is possible that successful inhibition of ACSL4 in breast cancer cells might render these cells more sensitive to other treatments, both hormone-based as well as non-specific chemotherapeutic regimens.Additional data indicate that ACSL4 expression is associated with increased proliferation, migration and invasion of breast cancer cells both de novo fatty acid synthesis and as a result there has been a concerted effort to capitalize on this dependence by developing inhibitors of fatty acid synthetase (FASN). However, these attempts have yet to translate to the clinic due to issues involving lack of specificity and unacceptable toxicity [via blockade of ACSL4 might have advantages over a more general inhibition of de novo fatty acid synthesis in that there are four other long-chain fatty acid activating enzymes that would continue to function.Many cancers, including breast, are dependent on toxicity . InterfeSince ACSL4 has been demonstrated to play a role in augmenting synthesis of the inflammatory prostaglandin, PGE2, it may be possible to ameliorate its effects on proliferation, migration and invasion in QNBC by blocking the action of PGE2 at the level of its receptor, PTGER4. Such inhibitors already exist and it has been suggested that they might be effective in treating colon cancer . It is cDue to the role of ACSL4 in supporting sex steroid biosynthesis in adrenal and gonadal tissue, inhibition of ACSL4 activity may enhance the effects of treatments aimed at lowering endogenous levels/activity of these hormones.Finally, the central role of ACSL4 activity in mediating ferroptosis offers an additional, compelling rationale for determining the status of its expression in breast as well as other cancers, since only those cancers positive for its expression are sensitive to induction of classical ferroptosis as a possible treatment modality. It is conceivable that in the future many different types of malignancies will routinely be assessed for expression of ACSL4 as a prerequisite to treatment with ferroptosis-inducing reagents.To date, initiatives aimed at the development of ACSL4 as a biomarker for classification of molecular subtype or as the basis for treatment have been lacking. While gene expression data are available, protein expression data are limited. It will be mandatory to generate such data to verify the utility of ACSL4 measurement as both a biomarker and treatment target. With respect to breast cancer, expression of ACSL4 protein would strongly suggest insensitivity to receptor-targeted treatment while indicating potential sensitivity to induced ferroptosis. Inhibitors of ACSL4 activity could prove useful in slowing proliferation of ACSL4-positive cancers. While the use of receptor biomarkers in the diagnosis and treatment of breast cancer has proved extraordinarily useful, perhaps it is time to consider adding routine measurement of ACSL4 protein as a predictive indicator in the management of breast cancer.ACSL4 has been demonstrated to play a pivotal role in both normal physiology as well as in a variety of disease states, including breast and other cancers. Data support a potential role for this protein as a single biomarker for classification of breast cancer subtypes, since its expression is indicative of a negative receptor status/resistance to receptor-dependent treatments with respect to ER, PR, AR and HER2 in breast cancer. ACSL4 status has also been demonstrated to predict response to a variety of chemotherapeutic reagents as well as to ferroptotic reagents. The ability of ACSL4 to induce a more aggressive phenotype suggests it might be a potential target for inhibition in the treatment of breast cancer. Additional studies are needed to demonstrate the utility of this protein as both a biomarker and target in the classification and treatment of breast cancer. In particular, an assessment of ACSL4 protein expression in breast tumor samples is needed to ascertain the utility of this protein as a predictive and prognostic biomarker.


Throughout the course of pregnancy, small maternal spiral arteries that are in contact with fetal tissue undergo structural remodeling, lose smooth muscle cells, and become less responsive to vasoconstrictors. Additionally, placental extravillous trophoblasts invade the maternal decidua to establish an interaction between the fetal placental villi with the maternal blood supply. When successful, this process enables the transport of oxygen, nutrients, and signaling molecules but an insufficiency leads to placental ischemia. In response, the placenta releases vasoactive factors that enter the maternal circulation and promote maternal cardiorenal dysfunction, a hallmark of preeclampsia (PE), the leading cause of maternal and fetal death. An underexplored mechanism in the development of PE is the impact of membrane-initiated estrogen signaling via the G protein-coupled estrogen receptor (GPER). Recent evidence indicates that GPER activation is associated with normal trophoblast invasion, placental angiogenesis/hypoxia, and regulation of uteroplacental vasodilation, and these mechanisms could explain part of the estrogen-induced control of uterine remodeling and placental development in pregnancy.Although the relevance of GPER in PE remains speculative, this review provides a summary of our current understanding on how GPER stimulation regulates some of the features of normal pregnancy and a potential link between its signaling network and uteroplacental dysfunction in PE. Synthesis of this information will facilitate the development of innovative treatment options. Preeclampsia (PE) is a pregnancy-specific syndrome that is estimated to affect approximately 4–5% of pregnancies worldwide –3. In deRecent evidence reveals that PE induces short-term health consequences for both mother and child, with increased risk of cardiorenal disturbances in later life –13. TherNormal early human placental development involves envelopment of the embryo inside the endometrial lining around day 10 post-conception. Under hypoxia and hypoglycemia, nutrition of the blastocyst is provided by secretions from the endometrial glands until the placental circulation is completely established . At 8–10In placentas that develop PE, EVTs fail to transform from the proliferative epithelial to the invasive phenotype, which is the main cause of incomplete remodeling of the spiral arteries . DysfuncSecondary to shallow EVTs invasion, the ischemic and structurally-damaged placenta releases factors into the systemic circulation in an attempt to increase blood flow and oxygen delivery to the fetus. However, these factors also increase oxidative stress in syncytiotrophoblasts (STBs), a continuous, specialized layer of epithelial cells covering the chorionic villi . StresseThe uteroplacental interface undergoes a pro-oxidant stage in the first weeks of normal pregnancy, as the increase in the metabolic rate ensuring adequate fetal development comes together with oxidative stress in the placental tissues. This period of gestation is also characterized by the high expression and activity of antioxidant enzymes to maintain oxidative balance .2•−), ROS molecules that damage the placenta  promote the proliferation and angiogenesis required for placental development . In thisThe biomolecular roles of GPER in hypoxia and angiogenesis during PE have not been dealt with in-depth yet, with only few studies presenting general data such as changes of GPER expression levels in HTR8/SVneo cells submitted to hypoxia-reoxygenation  and GPER2 tension upregulates HIF-1α which, in turn, increases the expression of GPER, and that these both molecules are recruited to the hypoxia-responsive element site located within the VEGF promoter region and cooperatively act as a functional complex for the transcription of VEGF and induction of tumor angiogenesis [The relationship between GPER and HIF-1α seems to be cycle-regulated, as some studies show that GPER expression is increased by HIF-1α , 125, anogenesis . De Franogenesis .As addressed earlier in the present work, HIF-1α levels are increased throughout pregnancies complicated by PE. Therefore, intriguing questions arise: (1) If HIF-1α stimulates the transcription of GPER independently of estrogen agonism in malignant cells, why is the GPER expression reduced in hypoxic placentas? (2) Shouldn’t the relationship between HIF-1α and GPER be cycle-regulated in the PE context as well? Further identifications of context-specific HIF-1α and GPER interaction pattern could be crucial for responding to these questions and developing targeted therapies for PE.Accumulating findings have been well described and reviewed in the literature, concerning the roles triggered by GPER in maintaining the homeostasis of the cardiovascular system , 128–132GPER vasodilation in rat uterine arteries has been found to be endothelium-dependent and mediated by the nitric oxide-cyclic guanosine monophosphate (cGMP) axis  considerIn this review, we have discussed the link between GPER activity and some of the key pathophysiological features of PE. It is evident that the roles of GPER in the regulation of uteroplacental cell functionality in normal pregnancy and in the preeclamptic environment are largely unknown. The successful characterization of GPER as a pharmacological target to treat PE requires significantly more research into what determines its potential of modulating biomarkers of oxidative stress, hypoxia, angiogenesis, inflammation and vascular dysfunction. Since most of the studies that are designed to clarify the mechanisms by which GPER affects uteroplacental biology are performed in vitro, it will be important to unravel its roles in different in vivo models of PE, as well as in normal pregnancy.


Results: We found that the most investigated dietary factors in the present literature were gluten, dietary advanced glycosylated end products (dAGEs), vitamin D, fatty acids, and iron. The results concerning prenatal exposure to a gluten-free environment showed a consistently protective effect on the development of IA. Prenatal exposures to vitamin D and certain fatty acids appeared to protect against the development of IA, whereas in utero iron and fat exposures correlated with increased risks of IA. Conclusion: We conclude that a definite association is not established for most factors investigated as the literature represents a heterogeneous pool of data, although fetal exposures to some maternal dietary components, such as gluten, show consistent associations with increased risks of IA. We suggest that human prospective dietary intervention studies in both cohort and clinical settings are crucial to better evaluate critical and protective prenatal exposures from the maternal diet during pregnancy.Aims and hypothesis: The incidence of type 1 diabetes mellitus in children is considerably increasing in western countries. Thus, identification of the environmental determinants involved could ultimately lead to disease prevention. Here, we aimed to systematically review (PROSPERO ID: CRD42022362522) the current evidence of the association between maternal dietary factors during gestation and the risk of developing type 1 diabetes and/or islet autoimmunity (IA) in murine and human offspring. Methods: In accordance with PRISMA guidelines, the present systematic review searched PubMed and Scopus ( Autoimmune diseases result from attacks on the body’s tissues by the immune system and comprise at least 80 diverse diseases where the etiology and pathogenesis are not fully elucidated. The incidence of autoimmunity is approximately 3–5% worldwide, and many of the associated diseases, including type 1 diabetes, are increasing in western societies, especially in children below the age of 5 . ConsideThis systematic review aims to evaluate the existing literature concerning the impact of prenatal, dietary factors as part of the environmental determinants of type 1 diabetes and islet autoimmunity, in murine models and in human case-control and birth cohort studies. We will answer the following questions: (1) Which prenatal dietary factors have already been investigated? (2) Can available data suggest protective advantages or hazards of certain prenatal dietary factors for the development of type 1 diabetes and IA in the offspring? (3) Does the pool of accessible data represent homogenous and conclusive information?The systematic review is registered in PROSPERO (CRD42022362522), reported in accordance with Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P), and follows the PRISMA guidelines, as described extensively in Shamseer et al. and Moher et al. ,16 to syPoulation: pregnant murine or human females where data about nutrient factor exposures during prenatal life and the risk of developing type 1 diabetes and/or islet autoimmunity in the offspring are available.Intervention: nutrient interventions and factors that may affect the incidences or occurrences of type 1 diabetes and islet autoimmunity.Comparison: only studies comparing a proper, nonexposed control group with an exposed group were considered eligible.Outcome: changes in type 1 diabetes or IA incidence in offspring of exposed mothers.The present systematic review assesses the following population, intervention, comparison, and outcome (PICO) elements:In addition to the PICO elements, we anticipate that the identification of prenatal dietary factors that influence the pathogenesis of type 1 diabetes could be used in the prevention of the disease.Reviews and meta-analyses from the search were screened for references, but not included in the final report. Regarding murine studies, only dietary intervention studies were included, whereas both prospective and retrospective population-based human birth cohort and case-control studies were included.For murine studies, inclusion criteria were intervention studies, where a defined maternal dietary factor was the exposure, and the readout was either IA or diabetes incidence or time-to-onset assessments in the offspring. Studies where the dietary intervention lasted for only the in utero period and during gestation until weaning were included. As with murine studies, human studies eligible for inclusion had one or more defined maternal dietary factors as prenatal exposure and examined either IA, type 1 diabetes, or both as endpoints. For animal studies examining islet autoimmunity, considered parameters were degree/score/index of insulitis (infiltration of immune cells in the pancreatic islets). Where information of the amount of apoptotic cells, inflammatory cell signaling, inflammatory marker RNA levels, and cytokine protein levels were included in the reviewed articles, this information was also extracted and included in the extensive data tables. Both studies prospectively and retrospectively assessing exposure and outcome were eligible for inclusion. Studies that did not satisfy the stated inclusion criteria were excluded and exclusion reasons were reported .An independent reviewer (V. B. I. J.) selected the studies using a two-step screening approach to assess eligibility as described above and in accordance with PRISMA guidelines. The reference lists of selected articles were further searched for relevant articles that were subsequently subjected to the two-step screening method described A. ReviewBriefly, data collection concerned study design and outcome .The performed search resulted in 343 articles whereof 99 were duplicates from the two different databases. Following the two-step screening approach, 50 articles were eligible for full-text screening, of which 15 articles were excluded . More thAll murine studies examined both diabetes and IA as endpoints, except Essien et al.  reportinOf the 23 eligible human studies, 18 evaluated the association between prenatal, dietary factors and the incidence of type 1 diabetes in the offspring ,54,55,56Low vitamin D levels have been linked to the development of autoimmune diseases , possibl65, IA-2, and insulin autoantibodies in children from the Diabetes Auto Immunity Study in the Young (DAISY) study [In 2003, Fronczak and colleagues reported that maternal vitamin D intake during pregnancy had a protective effect on the child’s risk of developing IA by evaluating measures of GADY) study . InteresY) study . HoweverY) study . Also, wY) study  could noY) study , when thY) study . AlthougIn the early 2000s, a Norwegian research team studied the effect of administrating cod liver oil and other vitamin D-containing supplements during pregnancy. They found that consumption of cod liver oil during pregnancy had a protective effect on the risk of offspring type 1 diabetes  whereas Proline and glutamine-rich gluten proteins are highly hydrophobic and partially resistant to intestinal degradation, which makes them more immunogenic than other nutritional proteins that are efficiently hydrolyzed into single amino acids . Markedln = 247) with a mean follow-up period of 15.6 years, and the risk of type 1 diabetes in the children increased proportionally with maternal gluten intake during pregnancy. Women with the highest gluten intake doubled the risk of type 1 diabetes development in their offspring, which illustrates a potential for gluten intake during pregnancy to significantly affect the childrens’ risk for type 1 diabetes development, supporting the animal studies. However, the findings were not confirmed in the Norwegian birth cohort study, the MoBa cohort [The human DAISY study revealed that maternal consumption of neither gluten-containing foods nor non-gluten cereal grains during pregnancy was associated with the incidence or onset of IA in the children . In the a cohort . The difa cohort .n-6/n-3 fatty acid ratio during the gestation and/or lactation period, developed diabetes faster than offspring from mothers, who were fed a chow diet with low ratio during pregnancy. Interestingly, pups fed a high-fat chow diet after weaning, but born from mothers fed a low-fat chow diet, had a significantly lower diabetes incidence compared to the group of pups fed a low-fat chow diet, but born from mothers fed a high-fat chow diet during gestation and/or lactation [n-3 fatty acid supplementation during pregnancy was not associated with the risk of IA in the offspring [Evaluation of NOD mice offspring from 0–50 weeks after birth showed that offspring, born from and lactated by mothers fed a chow diet with high actation . Additioactation . Similaractation . Howeveractation , and in ffspring .A case-cohort study, using the Danish National Birth Cohort comprising approximately 100,000 Danish pregnant women, and CPR linkage to the Danish Childhood Diabetes Register, found no association between maternal consumption of iron during pregnancy and type 1 diabetes in the offspring . Iron ovIn utero dietary deficiencies or overloads might alone, or in combination with other environmental factors, play a role in the process leading to the development of type 1 diabetes and IA in children. A potential mechanism of how diet during pregnancy could influence the development of IA and type 1 diabetes in the offspring could be the promotion of either an inflammatory or anti-inflammatory environment ,62,66,67This systematic review followed the PRISMA guidelines and evaluated the present literature focusing on in utero dietary exposures and the impact on type 1 diabetes and IA. Maternal consumption of nutritional products, such as gluten, iron, and high fat diet during pregnancy was associated with increased risks of type 1 diabetes and/or IA in the offspring, whereas in utero vitamin D and specific fatty acid exposures protected against these endpoints in some studies. However, these results represent a rather heterogeneous pool of data, and inconsistencies are present, illustrating the importance of research in this field. No prenatal, dietary factor has unequivocally been identified that modulate the frequency of T1D in the child. Thus, it is at present difficult to recommend or discourage specific components from the maternal diet to minimize the disease development in a child with high genetic risk for T1D. Our findings should initiate novel human, prospective, dietary intervention studies in both cohort and clinical settings, which are needed to better understand critical and protective prenatal exposures from the maternal diet during pregnancy. Conclusions from such studies could be an important way to prevent the development of type 1 diabetes in children at genetic risk of the disease.A contributing factor that may be responsible for the lack of consistency in the current literature is that we likely do not know all the risk factors of IA and type 1 diabetes at present. This would explain the heterogenous results and it suggests basic research within this field to further elucidate the environmental and genetic determinants underlying type 1 diabetes. Importantly, committees, guiding and advising pregnant women concerning prenatal dietary exposure, need to carefully consider the findings in the literature. Furthermore, there is a lack of a concluding studies and review/meta-analysis investigating the effect of non-medical interventions  that could be used in IA positive children to prevent progression to type 1 diabetes.


Many studies have demonstrated the benefits achieved in the majority of patients treated with DAAs 2015), due to the significant reduction in liver morbidity and mortality observed [5, due toCancers [As part of this editorial, we have selected three compelling articles recently published in the journal Cancers ,4,5, whiCancers  or hepatCancers .the AMBER study [The first paper by Flisiak et al.  presentsER study , of 192 p < 0.01 through KM analysis).The PITER study, based on an Italian multicenter prospective data collection , showed sword of Damocles” on the head of cases with LTR, particularly in those with F3–F4 staging according to the Metavir fibrosis classification.The importance of Child class B was further confirmed in a study on 139 HCV-related cirrhotic patients, whose condition was independent of a previous history of HCC . The samTherefore, in response to this issue, Caviglia et al.  attemptea point of no return, which leads to an unfavorable long-term disease outcome in the majority of cases. The early identification of these cases may be predictable through the non-invasive TE measurement of spleen stiffness (SS) or through the application of combined scores, such as the LS–spleen diameter to platelet score (LSPS) [Despite the fact that LTR after DAA administration has been found to be associated with slowing down the progression of liver disease in many cases with advanced fibrosis, those with clinically significant portal hypertension have probably passed e (LSPS) ,13. These (LSPS) ,14.to face the other side of the coin and conclude our perspective on this topic. The authors present a retrospective-multicenter analysis of 1389 cases with HCC, which includes patients who developed HCC who were either viremic (78%) or non-viremic following DAA therapy (301 cases) to compare the characteristics and survival curves between the cases. The non-viremic status in the cases with HCC occurrence correlated significantly with higher survival (153.3 vs. 55.6 months) in comparison with the HCC viremic cases, with them also showing a lower rate of obesity, metabolic dysfunction-associated steatotic liver disease (MASLD), and liver cirrhosis and better liver function and an earlier stage of HCC (BCLC stage 0-A in 74.8%). This fact certainly also determines the chance of receiving curative tumor treatment compared to viremic cases with HCC . By applying selective criteria and propensity matching scores, this retrospective study demonstrated that viremic cases with HCC undergoing DAA therapy showed amelioration of liver function and a longer survival rate after viral eradication [Finally, the retrospective, multicenter collection by Yeh et al.  offers uIn conclusion, many aspects that drive the onset of HCC in cases with LTR after DAA administration remain unsolved, implying a more intimate cellular mechanism, for example, the unreversibility of the genetic tumor risk signature , the HCVTherefore, the hypothesis of sequential events favoring the onset of HCC after DAA administration may be rational, and some biomolecular events, even indirectly triggered by HCV or DAA administration in cases with an aptitude for more clinically advanced liver disease and/or biological genetic signatures, could be crucial for the acquisition of HCC status, even after a long-term response to DAA administration.The Main Take-Home Message from These Studies Are The Following(a) The benefit of DAAs in the treatment of CHC is closely related to the patient’s stage of liver fibrosis , with th(b) DAAs do not eliminate HCC risk even in cases with LTR; thus, careful surveillance for HCC is mandatory and must offer better and more radical intervention for all cases, which often involves the patients’ listing for liver transplantation.(c) Non-invasive scoring systems mainly reflecting hepatic function must be associated with standard fibrosis staging methods  for the identification of patients at higher risk of de novo HCC during long-term FU after DAA administration.


Such stresses include cold stress, heat stress, high stocking density, feed restriction environmental and pollutants ; “this being first report in any vertebrate species that following a stressor there occurs significant increases of CRH2 gene expression in two neural structures that play a role in regulating the stress response, the nucleus of the hippocampal commissure and the paraventicular hypothalamic nucleus, resulting in a sustained increase in the stress hormone, corticosterone” .There are multiple members of the CRH family of genes/peptides across the vertebrates: CRH in eutherian mammals , CRH 2 in multiple vertebrate groups but neither in eutherian mammals nor teleost fish, urocortin (UCN) 1, 2, and 3 ; the lasKang). This is consistent with neurons in the premammillary being dual sensory-neurosecretory units (Kang). Moreover, there was greater expression of tryptophan hydroxylase 2, tyrosine hydroxylase and glucocorticoid receptor in the ventral tegmental area in birds raised on low that higher light intensity or on variable light intensity .There is increasing information of gene expression in neurons within the hypothalamic stress related nuclei in birds. For instance, the premammillary (PMM) nucleus contains neurons expressing enzymes required for the synthesis of dopamine and melatonin together with expression of the light sensitive opsin (Kadhim and Kuenzel).There is cross-talk between the hypothalamo pituitary adrenocortical and thyroid axes in birds with thyrotropin releasing hormone (TRH) receptor 2 present in avian thyrotropes. Chicken thyrotropes not only express CRH-R2 but also both CRH (CRH 1) and urocortin 3 (another ligand for the CRH-R) stimulate thyrotropin release . Somatossalmonella challenge . Salmonella challenge was associated with depressed growth rate in convention broiler chicks but not slow growing chickens .Pathogens represent a stressor affecting poultry. There were marked differences in ileal and cecal microbiome between conventional broiler chickens and slow growing birds and following Brugaletta et al.). Both growth and feed intake were decreased in 1995 random bred , and fast growing modern random bred (a mixture of the broilers of the 2020s) subjected to heat stress but did not influence growth or feed intake in either Jungle fowl, Athens Canadian Random Bred  . However, hypothalamic expression of feeding related neither neuropeptides nor their receptors were not affected by elevated environmental temperatures .Heat stress adversely affects poultry. In this Research Topic, differences in the responses to heat stress were reported between unselected broiler type chickens and chickens highly selected for growth . Body condition scoring rubric for welfare assessment was employed also to assess the welfare of the birds . Heat stress depressed welfare as assessed by feather quality and cleaniless together with foot pad condition . Chronic heat stress was accompanied by increases in the norepinephrine concentrations in the egg albumin but not yolk of domestic ducks However, there were no effect of chronic heat stress on the concentrations in the norepinephrine precursor, L-3,4-dihydroxyphenylalanine (l-dopa) in either the albumin and yolk .Heat stress was accompanied by increases in the plasma concentration of both corticosterone and cortisol but decreases in egg production in domestic female ducks (4), testosterone and estradiol (E2) . Hypothalamic expression of TRH was increased in ducks on 24L:0D but decreased in 8L:16D . Similarly, expression of TSH β sub-unit in the anterior pituitary gland was increased in ducks on 24L:0D but decreased in 8L:16D . It is questioned whether continuous lighting is stressful.Domesticated birds respond to two characteristics of light, namely, duration and intensity. Transfer of mountain ducks from a long-daylength (17L5D) to continuous lighting (24L:0D) was accompanied by increased plasma concentrations of gonadotropin releasing hormone (GnRH), luteinizing hormone (LH), prolactin, progesterone . Moreover, the responses to a novel object test were greater in young broiler chickens raised under a low light intensity compared to a higher light intensity which in turn were greater than birds under a variable lighting regimen . There was greater expression of tryptophan hydroxylase 2 in both the caudal raphe nucleus and the dorsal raphe nucleus . There were also differences with birds on natural lighting . It is also questioned whether low and/or high light intensities and/or an environment with little differences in light intensity are stressful.Light intensity influences birds. For instance, the incidence of dust bathing was greater in broiler chickens raised with a variable light intensity in different parts of the pen compared to either those raised on either 5 or 20 lux light intensity . In addition, the were line/genetic differences in plasma concentrations of corticosterone, heterophil to lymphocyte ratio and physical asymmetry .Fear is a stressor. Line differences in fear related behaviors in laying hens such as latency following tonic immobility and vocalization following isolation stress  in the liver and muscle, plasma concentrations of aminomethylphosphonic acid (AMPA) and cecal concentrations of short chain fatty acids . Moreover, in a companion paper, the same group reports differences in growth rate, circulating concentrations of triglyceride and the adipokinin, chemerin, together with abdominal adiposity and behaviors in the progeny of hens that had previously been treated with glyphosate-based herbicide compared to control hens (Chickens are used as models for the effects of potential toxicants in the environment on reproduction. An example of this is a definitive study by rol hens .


Relative humidity (RH) is a common interferent in chemical gas sensors, influencing their baselines and sensitivity, which can limit the performance of e-nose systems. Tuning the composition of the sensing materials is a possible strategy to control the impact of RH in gas sensors. Hybrid gel materials used as gas sensors contain self-assembled droplets of ionic liquid and liquid crystal molecules encapsulated in a polymeric matrix. In this work, we assessed the effect of the matrix hydrophobic properties in the performance of hybrid gel materials for VOC sensing in humid conditions (50% RH). We used two different polymers, the hydrophobic PDMS and the hydrophilic bovine gelatin, as polymeric matrices in hybrid gel materials containing imidazolium-based ionic liquids, [BMIM][Cl] and [BMIM][DCA], and the thermotropic liquid crystal 5CB. Better accuracy of VOC prediction is obtained for the hybrid gels composed of a PDMS matrix combined with the [BMIM][Cl] ionic liquid, and the use of this hydrophobic matrix reduces the effect of humidity on the sensing performance when compared to the gelatin counterpart. VOCs interact with all the moieties of the hybrid gel multicomponent system; thus, VOC correct classification depends not only on the polymeric matrix used, but also on the IL selected, which seems to be key to achieve VOCs discrimination at 50% RH. Thus, hybrid gels’ tunable formulation offers the potential for designing complementary sensors for e-nose systems operable under different RH conditions. Electronic-noses (e-noses) are devices that mimic the biological olfactory system, by combining an array of independent semi-selective gas sensors with a signal transduction unit and a pattern-recognition system, allowing the differentiation of distinct odors ,2,3. GasHumidity is a common interferent in gas sensors and it can seriously affect sensors’ performance ,8,9. DifIn the present work, we aim at understanding the effect of the polymer hydrophobicity in hybrid gel gas sensors’ response to humidity. Furthermore, we assess the hybrid gel sensors’ performance to classify different VOCs in a humid atmosphere (average 50% RH). For that, we studied hydrophobic (PDMS) and hydrophilic (bovine gelatin) matrices to incorporate liquid crystal–ionic liquid droplets. We employed the well-studied ionic liquids from the imidazolium family, [BMIM][DCA] and [BMIM][Cl] , and theThe polymer polydimethylsiloxane  was purchased from The Dow Chemical Company , and gelatin from bovine skin  was purchased from Sigma Aldrich . The liquid crystal 4-cyano-4′-pentylbiphenyl  was purchased from TCI Europe . The ionic liquids 1-butyl-3-methylimidazolium dicyanamide ([BMIM][DCA] > 98.0%) and 1-butyl-3-methylimidazolium chloride  were purchased from IoLiTec . The anhydrous binary salts magnesium chloride (≥98.0%), potassium carbonate (99.9%) and sodium bromide (≥99.0%) were purchased from Sigma-Aldrich ; sodium chloride (>99.5%) and the solvents dichloromethane and hexane were purchased from VWR International . Ethanol and acetic acid (purity 99.8%) were purchased from Sigma-Aldrich . Acetonitrile (purity 99.9%), chloroform, diethyl ether (HPLC grade), ethyl acetate, heptane, methanol (HPLC grade) and toluene were supplied by Fisher Scientific . Acetone (purity 99.5%) was purchased from Honeywell , and isopropanol (purity 99.5%) from ROTH .The gelatin hybrid sensors containing the ionic liquids (ILs) [BMIM][DCA] or [BMIM][Cl] and the liquid crystal 5CB were prepared as previously described ,13. To pThe films were left at room temperature and a controlled humidity (50% relative humidity) before further use. For the morphological characterization of the prepared films, we used polarized optical microscopy (POM) and scanning electron microscopy (SEM). For the POM analysis, images were taken under crossed (at 90°) and semi-crossed (at 45°) polarizers, as well as under the absence of polarizers (bright field) in a Zeiss Axio Observer. Z1/7 microscope equipped with an Axiocam 503 color camera and ZEN 2.3 software for image acquisition and processing. As for the scanning electron microscopy (SEM), observations were conducted on a Carl Zeiss AURIGA CrossBeam (FIB-SEM) workstation coupled with energy dispersive X-ray spectroscopy (EDS). The dried hybrid gel materials were previously coated with an Ir and Au/Pd conductive film to avoid charge effects. Stability to long-time storage was also evaluated by following a selected optically active region of interest by POM, for a period of a month.Humidity reference sensors  were installed in the outlet of the detection chamber of the optical signal transducer device to record the variations of relative humidity in the chamber and in the cap of the saturated salt solution vial to record the generated RH . The meaTriplicates of sensing films were placed in the detection chamber and exposed to five humidification/drying periods for each RH level. The optical signals were acquired with the associated in-house developed optical signal transducer at constant temperature (room temperature of 22 ± 2 °C) ,14,15,16To assess the performance of the hybrid gels as sensors and to classify 12 distinct VOCs with small structural differences, a tailor-made optical e-nose was used ,13. The The sensors were positioned in the six sensor slots of the detection chamber, including three films of each PDMS and gelatin matrix gels—PDMS with [BMIM][DCA], PDMS with [BMIM][Cl], gelatin with [BMIM][DCA], gelatin with [BMIM][Cl] and the two control sensors (the formulation without ionic liquid). Their responses were tested against a set of 12 saturated atmospheres of VOCs: heptane, hexane, chloroform, toluene, dichloromethane, diethyl ether, ethyl acetate, acetonitrile, acetone, ethanol, methanol and acetic acid (VOCs listed in order of exposure). The solvents were kept in a thermostatized bath at 37 °C, for at least 15 min prior to exposure. The VOCs were pumped for 5 s into the detection chamber, followed by 15 s of ambient air for recovery , completing 1 cycle. A total of 45 cycles were performed, totalizing 15 min of duration per test. The optical signals of all sensing films were acquired at a sampling rate of 90 Hz, and assays were performed in triplicates. The signals were then analyzed using python programming tools previously developed, including an automatic classifier algorithm based on support vector machines ,15,16,17To sample known concentrations of VOC  was used to program the carrier MFC and solenoid valve operation, as well as to synchronize them with the optical e-nose device and the readings of the reference RH sensor at the outlet of the detection chamber .SR) of each cycle was determined by subtracting its offset and normalizing it to its baseline, according to Equation (1):signal is the smoothed and filtered cycle signal and baseline is the average of the signal immediately before (10 sample points) the start of the exposure period.The raw optical signals yielded by the hybrid sensors were firstly filtered with a median filter (to attenuate sporadic high intensity noise peaks) and smoothed with a Hanning window smoothing filter (to attenuate high frequency noise). Then, using a custom-made Python 3.7 script, the resulting signals were divided in cycles. The relative optical signal (aR), defined as the maximum variation of the relative optical signal .Regarding the humidity assays, for each cycle, the following features were extracted from the relative optical signal using custom-made Python 3.7. scripts: maximum derivative, minimum derivative and relative amplitude (rest), defined as the time required to reach the maximum variation of the relative optical signal (SR) after the start of a humidity step change (t0), was estimated from the response speed Equation (2) both for the humidification and for the drying periods of the experiments.The minimum and maximum derivatives were used to calculate the slope of the signals in the humidification and drying periods, which correspond to the response speed to relative humidity step changes. The response time , as reported previously ,14,15,16Liquid crystal molecules are appealing for sensing purposes due to their high molecular order and intrinsic stimuli-responsive nature, turning them into fast optical probes. In particular, the confinement of liquid crystal molecules into spherical arrangements increases the available surface area and yields a variety of optical textures that can be used as input signals ,19. The The produced gelatin and PDMS-based optical hybrid gels were firstly characterized by SEM and polarized optical microscopy (POM) to observe the morphological and optical textures, and to infer on liquid crystal molecular arrangements within the materials .In gelatin-based films, SEM images confirmed that the flexible, and yet robust, gelatin matrix contains droplets at its surface as previously reported . For thev/v) allows for better phase separation between the liquid crystal and the polymeric matrix. This effect prevents droplet coalescence, leading to the formation of small radial droplets  when compared to the PDMS control gel, polydisperse and occasionally irregularly shaped droplets are detected as a result. The droplets are very polydisperse in size and in most cases are significantly larger than those observed in the PDMS control gels. This induces weaker anchoring conditions between the liquid crystal and the polymer, leading to formations which feature a variety of configurations, typically bipolar  and [Cl−] anions give rise to different physical constraints upon interactions with the imidazolium headgroup [BMIM+]. Since both nitrile and chloride anions exhibit a similar ionic radius  [−] contains two nitrile groups, it is likely that due to steric hindrance at the droplet interface, the [DCA−] anion facilitates the formation of larger droplets when compared to those containing [Cl−].Interestingly, the ionic liquid presence in hybrid gels leads to distinct optical textures and droplets sizes . For thectively)  and consTo evaluate the stability of the hybrid gels to storage at room temperature and controlled humidity conditions (50% RH), we monitored the films by POM during one-month. In general, droplets in [BMIM][DCA] materials, using either PDMS or gelatin, lead to more stable to storage optical sensors when compared to those bearing [BMIM][Cl] .The presence of liquid crystal molecules encapsulated within droplets in the PDMS and gelatin matrices makes it possible to study the changes in optical textures derived from the interaction of chemical analytes with the sensing films. In particular, the liquid crystal molecules inside the droplets can manipulate the polarization of light, allowing the transmission of light in optical devices under crossed polarizers. Based on previous works, the disruption in the organization of liquid crystal molecules within the droplet leads the molecular ordering to reversibly change from the nematic . The hybrid gels and respective controls were sequentially exposed to twelve VOCs from distinct chemical classes and small structural differences. The sensors were exposed to saturated atmospheres of the following compounds: heptane, hexane, chloroform, toluene, dichloromethane, diethyl ether, ethyl acetate, acetonitrile, acetone, ethanol, methanol and acetic acid (VOCs listed in order of exposure). The representative relative optical signals obtained for each sensor and VOC are shown in Considering the [BMIM][DCA]-based sensors, gelatin materials yielded signals with higher relative amplitudes and distinct responses to VOCs when compared to PDMS. For example, gelatin materials were unresponsive to acetic acid but more responsive to hexane and heptane. For the [BMIM][Cl]-based sensors, those containing PDMS yielded relative signals with higher amplitude and sharper signals with fast response and recovery. In the case of the control sensors, the PDMS controls gave very low signals to VOCs except for acetone which yielded a relative optical signal 10 times higher than the IL-containing sensors. In the case of gelatin controls, relative signal amplitudes were also higher than the IL-containing sensors, in particular the response to acetic acid which was extremely high for IL-gelatin sensors. The signals’ response times depend on a combination of factors related to the composition of the sensing material (such as the hydrophilicity of the polymer matrix and the size of the droplets) and with the chemical nature of the VOC itself  and favoAfter signals collection, the data were analyzed through machine learning tools, using several features and parameters of curve fitting models as inputs for support vector machine-based classification algorithm. This resulted in plots summarizing mean normalized wave signals deriving from each VOC–gel interaction yielding typical signals, and also confusion matrices , where tThe volatiles prediction performance, in general, was higher for the PDMS with [BMIM][Cl] ionic liquid, achieving, on average, 56% of correct predictions, being the best results for acetic acid (96%), acetonitrile (86%) and hexane (77%), and the worst for methanol (17%). On the other hand, the lowest rates of correct predictions were obtained for the same matrix using the [BMIM][DCA] ionic liquid, which yielded, on average, a correct prediction rate of 33% scoring relatively good values for acetonitrile (59%) and toluene (64%).The [BMIM][DCA]–gelatin matrices presented better scores for ethanol (72%), methanol (72%), heptane (70%) and hexane (62%) prediction, when compared to [BMIM][DCA] in PDMS, obtaining an average rate of correct predictions of 45%. For [BMIM][Cl] in the gelatin matrix, good scores were also found in general for volatiles such as acetic acid (64%), acetonitrile (66%) and hexane (66%), similar to [BMIM][Cl] in the PDMS matrix, which points to the critical role of ionic liquid in VOCs discrimination. Additionally, [BMIM][Cl] in gelatin presented the best discrimination for chloroform (85%) of all gels.The presence of PDMS in the formulation of the sensing films favored the distinction of both toluene and acetonitrile, while the gelatin matrices performed better for heptane, hexane and chloroform discrimination. Overall, the results corroborate the joint effect of all the moieties of the multicomponent hybrid gels during VOC interaction, and also point out the important impact of the IL on VOCs discrimination. Furthermore, the diversity in the sensors’ composition and the complementary accuracy results obtained open the possibility to combine the results from several sensors to improve VOC discrimination.After assessing the effect of humidity and the potential for VOC sensing in humid conditions using PDMS and gelatin hybrid gels, we assessed their limit of detection for selected VOCs under humid conditions. Ethanol, acetone, toluene and hexane were chosen as the representatives of chemical groups with distinct polarity, hydrophilicity and affinity to the components of the studied materials ,30. The To ensure a constant baseline for the VOC experiments, the films were first allowed to stabilize for 15 min in 50% RH. In addition, a calibration blank assay under the same humidity and nitrogen flow rates but without VOC was performed, to discount the interference of noise in the signal, where it was previously seen that the optical signal from noise causes a minimal interference .The relative optical responses to increasing concentrations of VOCs under a controlled RH of the hybrid films containing [BMIM][DCA] or [BMIM][Cl] in a PDMS or gelatin matrix are represented in −] to [Cl−] does not cause an evident alteration in terms of VOC-sensitivity performance. The optical response of the films has very similar waveforms, but the limits of detection (LOD) towards each VOC differ for PDMS and gelatin-based films.The polarity of the VOCs influences the optical response of the films, as reported in our previous works ,13,20. M− counterion is slightly weaker than the [DCA]-counterpart, likely because ethanol being very polar interacts strongly with surrounding water molecules, and films containing [BMIM][Cl] are less responsive to humidity than [BMIM][DCA]-based films. Additionally, the LOD in PDMS and gelatin-based films for [BMIM][DCA] is slightly lower than for [BMIM][Cl]  than what is observed for gelatin (2.27% v/v).The response to hexane is significantly different between PDMS and gelatin-based films. In addition, the LODs vary by changing the counter-ion of the IL . The detThe more hydrophobic PDMS polymer easily interacts with the less polar VOCs, while gelatin likely has a greater affinity towards more polar VOCs. In the case of hexane, perhaps due to its greater hydrophobicity, it probably penetrates the IL droplets to interact with the LC and hydrophobic moiety of the IL, while the other VOCs are able to interact with the surface of the droplets .In summary, the change in the polymeric matrix between the PDMS and gelatin of the hybrid films does not produce an evident improvement in VOC-sensitivity sensing-performance. Yet, due to the opposing nature of the two polymers, the films complement well one another, in terms of sensitivity to distinct VOCs.Hybrid gel sensors were successfully produced using a PDMS matrix with 5CB liquid crystal and two different ionic liquids ([BMIM][Cl] and [BMIM][DCA]) and tested in an in-house built optical electronic nose device against a set of 12 different volatile organic compounds.The presence of PDMS in the formulation of the sensing films seems to favor in general the distinction of both toluene and acetonitrile volatiles in general, as opposed to the presence of gelatin, which seems to do the same for heptane, hexane and chloroform instead. In this work, however, we conclude that the classification of VOCs through these experiments are a consequence of the interactions with the entire multicomponent system, and not just dependent on the matrix individual component, but also that choice of the IL seems to be key to achieve different VOCs discrimination.The best overall VOC prediction performance was obtained for the PDMS with [BMIM][Cl] ionic liquid, yielding, on average a 56% rate of correct predictions, followed by PDMS control (scoring 41%), and the least accurate formulation was the PDMS with [BMIM][DCA] ionic liquid, achieving only 33% of general accuracy predicting volatiles.When comparing the PDMS gels with the traditional gelatin sensing films with two different ionic liquids, in terms of morphology they diverge a lot in both droplets’ visual appearance and quantity. As for the stability to long-time storage, sensing materials containing [BMIM][DCA] , proved to be the most stable gels, exhibiting radial stable droplets for over a one month period against the ones where [BMIM][Cl] ionic liquid is used, which proved to be very unstable .Studies regarding the optical response of the sensing films to different humidity levels were also conducted, and the results indicate that, overall, in the absence of ionic liquid in the sensors composition (control films), the influence of humidity in the optical sensors response derives essentially from the hydrophobic properties of the polymeric matrix.In summary, the use of PDMS as a supporting matrix for the thin films changes the effect of humidity on the sensing performance compared to gelatin, but it does not entirely optimize it; due to the presence of the amphiphilic IL, when adding the IL into the composition, the measured optical signal is mostly affected by the nature of the anion from the IL. A higher humidity effect is clearly observed for [BMIM][DCA]-containing hybrid gels. The amplitude of the optical response for PDMS-based hybrid gels is lower than for gelatin-based gels, indicating a lower water interference. Generally, sensors containing [BMIM][DCA] are more responsive to humidity variations, while films containing [BMIM][Cl] remain very unresponsive in comparison.VOC sensing-performance was also explored in this work, and conclusions can be drawn that neither gelatin nor PDMS-based films outperform one another, but the two distinct film recipes complement well each other. In the future, the sensors could be used in combination for VOC-sensing in distinct humidity conditions. Characterization of the sensors tackling issues such as the impact of temperature and the 3S  should be studied in more detail to fully understand these new materials.