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Efficient and sustainable seawater electrolysis is still limited due to the interference of chloride corrosion at the anode. The designing of suitable electrocatalysts is one of the crucial ways to boost electrocatalytic activity. However, the approach may fall short as achieving high current density often occurs in chlorine evolution reaction (CER)-dominating potential regions. Thereby, apart from developing an OER-active high-entropy alloy-based electrocatalyst, the present study also offers a unique way to protect anode surface under high current density or potential by using MoO4 2- as an effective inhibitor during seawater oxidation. The wide variation of d-band center of high-entropy alloy-based electrocatalyst allows great oxygen evolution reaction (OER) proficiency exhibiting an overpotential of 230 mV at current density of 20 mA cm-2. Besides, the electrocatalyst demonstrates impressive stability over 500 h at high current density of 1 A cm-2 or at a high oxidation potential of 2.0 V versus RHE in the presence of a molybdate inhibitor. Theoretical and experimental studies reveal MoO4 2- electrostatically accumulated at anode surface due to higher adsorption ability, thereby creating a protective layer against chlorides without affecting OER.
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BACKGROUND: Human infants develop IgG responses to dietary antigens during the first 2 years of life. Yet, the source of these antibodies is unclear. In previous studies we reported on the thymus as a unique functional niche for plasma cells (PCs) specific to environmental antigens. OBJECTIVE: We sought to examine whether PCs specific to dietary antigens are detected in the infant thymus. METHODS: We tested IgG reactivity to 112 food antigens and allergens in the serum of 20 neonates and infants using microarrays. The presence of PC-secreting IgG specific to the most prominent antigens was then assessed among thymocytes in the same cohort. Using an LC-MS proteomics approach, we looked for traces of these antigens in the thymus. RESULTS: Our studies first confirmed that cow's milk proteins are prevalent targets of serum IgG in early life. Subjects with the highest serum IgG titers to cow's milk proteins also harbored IgG-producing PCs specific to the same antigens in the thymic niche. Furthermore, we detected multiple peptide fragments of cow's milk antigens in the thymus. Lastly, we verified that both serum IgG and IgG secreted by thymic PCs recognized the peptide epitopes found in the thymus. CONCLUSIONS: Our studies reveal the presence of antibody-secreting PCs specific to common dietary antigens in the infant thymus. The presence of these antigens in the thymus suggested that activation and differentiation of specific PCs occurred in this organ. Further studies are now warranted to evaluate the possible implication of these cells in tolerance to dietary antigens.
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Hipersensibilidad a la Leche , Proteínas de la Leche , Recién Nacido , Animales , Femenino , Bovinos , Lactante , Humanos , Formación de Anticuerpos , Células Plasmáticas , Inmunoglobulina G , Leche , AlérgenosRESUMEN
Hydrogen production through pure water electrolysis is often found less economic as it requires high potential for water oxidation. The presence of urea in water involving effective urea oxidation can be considered as an effective strategy to produce hydrogen economically. Herein, we develop trimetallic nickel vanadium manganese nitride porous microspheres as an efficient bifunctional electrocatalyst for both urea oxidation reaction (UOR) as well as hydrogen evolution reaction (HER) mechanisms. The optimized NiVMn nitride exhibits eye-catching UOR activity along with HER activity that required only 1.36 and -0.253 V electrode potentials, respectively, to achieve a high current density of 100 mA cm-2. Combining its bifunctional activity in UOR and HER in a two-electrode system, an energy saving by 0.26 V potential compared to water electrolysis through water oxidation can be acquired to reach 50 mA cm-2 current density. The presence of manganese(II) has a significant influence in stabilizing high valence V(V) and Ni(II), offering large number of active sites, and during UOR, the effective electronic transitions are more between Mn â Ni rather than Mn â V, leading to excellent and stable UOR performance. Indeed, the electrocatalyst and the approach offering considerable energy saving phenomena are believed to make hydrogen production more economic and sustainable.
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Manganeso , Níquel , Vanadio , Hidrógeno , Urea , AguaRESUMEN
The intrinsic ability of defects within the electrocatalysts can be judiciously utilized in designing robust electrocatalysts for efficient seawater oxidation. Herein, we have fabricated a novel tungsten oxide phosphate (W12PO38.5) with optimized sulfur doping triggering the insertion of a large number of defect sites. This allows for boosted OER performance in alkaline freshwater as well as seawater, avoiding the unwanted chlorine evolution reaction. The optimized electrocatalyst achieved high current densities of 500 mA cm-2 at an overpotential of just 387 mV in fresh water and 100 mA cm-2 at 380 mV in alkaline seawater for OER. Besides the excellent catalytic performances, the developed electrocatalyst appeared to be a durable catalyst as well. An interesting electrocatalytic activation caused by the generous electronic redistribution led the electrocatalyst to achieve great stability over 100 h at a 100 mA cm-2 current density in alkaline real seawater.
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The identification of hydrogen as green fuel in the near future has stirred global realization toward a sustainable outlook and thus boosted extensive research in the field of water electrolysis focusing on the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). A huge class of compounds consisting of transition metal-based nitrides, carbides, chalcogenides, phosphides, and borides, which can be collectively termed transition metal non-oxides (TMNOs), has emerged recently as an efficient class of electrocatalysts in terms of performance and longevity when compared to transition metal oxides (TMOs). Moreover, the superiority of TMNOs over TMOs to effectively catalyze not only OERs but also HERs and ORRs renders bifunctionality and even trifunctionality in some cases and therefore can replace conventional noble metal electrocatalysts. In this review, the crystal structure and phases of different classes of nanostructured TMNOs are extensively discussed, focusing on recent advances in design strategies by various regulatory synthetic routes, and hence diversified properties of TMNOs are identified to serve as next-generation bi/trifunctional electrocatalysts. The challenges and future perspectives of materials in the field of energy conversion and storage aiding toward a better hydrogen economy are also discussed in this review.
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Óxidos , Elementos de Transición , Hidrógeno/química , Oxígeno , Agua/químicaRESUMEN
For progression of health care system, it has always been a challenge to the researchers for formulation to a type of advanced drug delivery system which will have less toxicity, targeted delivery and will be highly biodegradable. Nano science or nanotechnology has been validated to be a successful method as of targeting the drug to its active site be due to its special physicochemical properties and size thereby reducing the dose of administration, increasing bioavailability, and also reducing toxicity. Magnetic nanoparticles recently in few decades have proved as an effective advanced drug delivery system for its elevated magnetic responsiveness, biocompatibility, elevated targeted drug delivery effectiveness, etc. The drug can be easily targeted to active site by application of external magnetic field. Among the various elements, nanoparticles prepared with magnetically active iron oxide or other iron-based spinel oxide nanoparticles are widely used due to its high electrical resistivity, mechanical hardness, chemical stability, etc. Owing to their easy execution towards drug delivery application, extensive research has been carried out in this area. This review paper has summarized all recent modifications of iron-based magnetically active nanoparticle based drug delivery system along with their synthesis, characterization, and applications.
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Nanopartículas de Magnetita , Nanopartículas , Nanopartículas de Magnetita/química , Sistemas de Liberación de Medicamentos , Hierro/química , Nanotecnología , Técnicas de Transferencia de GenRESUMEN
T cells are implicated in the pathogenesis of cardiac allograft vasculopathy (CAV), yet their clonality, specificity, and function are incompletely defined. Here we used T cell receptor ß chain (TCRB) sequencing to study the T cell repertoire in the coronary artery, endomyocardium, and peripheral blood at the time of retransplant in four cases of CAV and compared it to the immunoglobulin heavy chain variable region (IGHV) repertoire from the same samples. High-dimensional flow cytometry coupled with single-cell PCR was also used to define the T cell phenotype. Extensive overlap was observed between intragraft and blood TCRBs in all cases, a finding supported by robust quantitative diversity metrics. In contrast, blood and graft IGHV repertoires from the same samples showed minimal overlap. Coronary infiltrates included CD4+ and CD8+ memory T cells expressing inflammatory (IFNγ, TNFα) and profibrotic (TGFß) cytokines. These were distinguishable from the peripheral blood based on memory, activation, and tissue residency markers (CD45RO, CTLA-4, and CD69). Importantly, high-frequency rearrangements were traced back to endomyocardial biopsies (2-6 years prior). Comparison with four HLA-mismatched blood donors revealed a repertoire of shared TCRBs, including a subset of recently described cross-reactive sequences. These findings provide supportive evidence for an active local intragraft bystander T cell response in late-stage CAV.
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Trasplante de Corazón , Aloinjertos , Vasos Coronarios , Rechazo de Injerto/etiología , Trasplante de Corazón/efectos adversos , Humanos , Linfocitos TRESUMEN
In this work, ammonia-assisted one step growth of SnO2 and mixed metal hydroxide CoSn(OH)6 on Ni foam is illustrated. The nanostructured films grown on Ni foam are highly porous in nature. The CoSn(OH)6 nanostructures were deposited using three different molar ratios of Sn/Co precursors i.e., 1:1, 1:2 and 2:1 and their performances as supercapacitor have been investigated and compared with pristine SnO2. Interestingly, the CoSn(OH)6 thin films prepared with 1:2 molar ratio of Sn/Co showed remarkably high areal capacitance and good cyclic stability. It is believed that the presence of different metal cations and their valence states along with the porous nanostructure makes the material outstanding as supercapacitor. The highest areal capacitance of 4189 mF cm-2 was obtained at a current density of 2 mA cm-2 for CoSn(OH)6 thin films offering an excellent cyclic stability with a capacity retention of 90.3% after 2000 cycles.
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Tin oxide thin films were uniformly deposited by successive ionic layer adsorption reaction (SILAR) method on glass substrates using ethylene diamine as a complexing agent. The proper annealing treatment in air converts as-deposited amorphous films into crystalline and removes defects, reducing strain in the crystal lattice. The films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Atomic Force Microscopy (AFM), Fourier Transform Infrared (FTIR) spectroscopy. The film shows good optical transparency in the range of 200-1000 nm wavelength and electrical resistivity decreases upon annealing.
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INTRODUCTION: The aim of the study is to assess and correlate the different cephalometric parameters used to determine the vertical jaw relationship. METHODS: Cephalometric radiographs from 148 patients were assessed and comparison was made using all eight parameters. Statistical analysis was performed using mean, standard deviation and coefficient of variance. A correlation was found between different variables using the Pearson's correlation coefficient. RESULTS: In the entire sample, the basal plane angle displayed the most variable distribution, while the R angle displayed the most homogeneous distribution. There was a significant correlation found between the Jarabak ratio, Steiner's mandibular plane angle (SN-GoGn), Frankfort mandibular plane angle (FMA), R angle, and DR angle. There was a moderate to weak correlation between the Y-axis, basal plane angle, and facial height ratio with other skeletal analyses. CONCLUSION: Among angular variables DR angle, R angle, SN-GoGn and FMA can be used and among linear variables Jarabak ratio could be used reliably to assess the growth pattern. It suggested that in order to obtain an accurate evaluation of the vertical jaw relationship, a variety of measurements should be combined.
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The quest for cost effective but active electrocatalysts for water oxidation is at the forefront of research towards hydrogen economy. In this regard, bamboo as biomass derived N-doped cellulosic carbon has shown potential electrocatalytic performance towards water oxidation. The impregnation of optimum metallic Fe boosts the performance further, achieving an overpotential value of 238 mV at a benchmark current density of 10 mA cm-2. Owing to its promising OER performances in alkaline freshwater, the electrocatalyst was further explored in alkaline saline water and alkaline real seawater, exhibiting overpotentials of 272 mV and 280 mV, respectively, to reach 10 mA cm-2 current density. Most importantly, the protective graphitic multilayer surrounding the metallic Fe allowed the electrocatalyst to demonstrate excellent durability over 30 h even at a high current density in alkaline real seawater electrolyte.
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Seawater electrolysis is considered to be very challenging owing to competitive reaction kinetics in between oxygen evolution reaction and corrosive chlorine evolution reaction mechanism at anode, especially towards higher current density. The present work, proposes a promising and energy efficient strategy by coupling seawater splitting with urea decomposition lowering oxidation potential and thereby avoiding hypochlorite formation even at high current density. The rational design of Mott-Schottky heterojunction of Se/NiSe2 as electrocatalyst is considered to be highly effective in this regard. The developed Se/NiSe2 exhibits extraordinary energy saving for alkaline seawater splitting in presence of urea. The Se/NiSe2/NF || Se/NiSe2/NF electrolyser configuration achieved 10 and 50 mAcm-2 current densities with cell voltage of 1.59 and 1.70 V along with outstanding operational durability over 50 h. The large number of carrier density generates by synergistic self-driven electron transfer from Se to NiSe2 at the heterojunction, unique metallic properties of selenium (Se), and also abundance accessible reactive edges on the porous channel of Ni foam are believed to be the reason behind such enhanced electrocatalytic activities towards urea oxidation reaction and hydrogen evolution reaction offering unique and much energy saving approach for alkaline-urea-seawater electrolysis avoiding hypochlorite formation.
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Selenio , Urea , Ácido Hipocloroso , Conservación de los Recursos Energéticos , Electrólisis , Agua de Mar , HidrógenoRESUMEN
The urea oxidation reaction (UOR) with low required oxidation potential is not only an energy-saving strategy for efficient hydrogen production but also offers an effective way to treat wastewater by decomposing urea. An amorphous cobalt oxyborate with optimum vanadium doping has been identified as an efficient electrocatalyst for UOR for the first time with great stability. The electrocatalyst requires only 1.37 V potential to achieve a current density of 20 mA cm-2. Impressively, the developed electrocatalyst exhibited very active and long stability in alkaline raw bovine urine as extreme urine sewage media coupled with efficient hydrogen production at the cathode.
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Electrocatalytic direct seawater splitting is considered to be one of the most desirable and necessary approach to produce substantial amount of green hydrogen to meet the energy demand. However, practical seawater splitting remains far-fetched due to the electrochemical interference of multiple elements present in seawater, among which chlorine chemistry is the most aggravating one, causing severe damages to electrodes. To overcome such limitations, apart from robust electrocatalyst design, electrolyte engineering along with in depth corrosion engineering are essential aspects, which needs to be thoroughly judged and explored. Indeed, extensive studies and various approaches including smart electrolyzer design have been attempted in the last couple of years on this matter. The present review offers a comprehensive discussion on various strategies to achieve effective and sustainable direct seawater splitting, avoiding chlorine electrochemistry to achieve industry-level performances.
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Natural antibodies are an integral part of innate humoral immunity yet their development and polyreactive nature are still enigmatic. Here, we show that characteristic monoclonal natural antibodies recognize common chemical moieties or adducts, supporting the view that polyreactive antibodies may often correspond to anti-adduct antibodies. We next examined the development of immunoglobulin M (IgM) and IgG to 81 ubiquitous adducts from birth to old age. Newborn IgM only reacted to a limited number of consensus determinants. This highly restricted neonatal repertoire abruptly diversified around 6 months of age through the development of antibodies to environmental antigens and age-driven epigenetic modifications. In contrast, the IgG repertoire was diverse across the entire life span. Our studies reveal an unrecognized component of humoral immunity directed to common adducts. These findings set the ground for further investigations into the role of anti-adduct B cell responses in homeostatic functions and pathological conditions.
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Anticuerpos Monoclonales , Antígenos , Recién Nacido , Lactante , Humanos , Inmunoglobulina M , Inmunoglobulina GRESUMEN
BACKGROUND: Potentially harmful nonhuman leukocyte antigen antibodies have been identified in renal transplantation, including natural immunoglobulin G antibodies (Nabs) reactive to varied antigenic structures, including apoptotic cells. METHODS: In this retrospective, multicenter study, we assessed Nabs by reactivity to apoptotic cells in sera collected from 980 kidney transplant recipients across 4 centers to determine their association with graft outcomes. RESULTS: Elevated pretransplant Nabs were associated with graft loss (hazard ratio [HR] 2.71; 95% confidence interval [CI], 1.15-6.39; P = 0.0232), the composite endpoint of graft loss or severe graft dysfunction (HR 2.40; 95% CI, 1.13-5.10; P = 0.0232), and T cell-mediated rejection (odds ratio [OR] 1.77; 95% CI, 1.07-3.02; P = 0.0310). High pretransplant Nabs together with donor-specific antibodies (DSAs) were associated with increased risk of composite outcomes (HR 6.31; 95% CI, 1.81-22.0; P = 0.0039). In patients with high pretransplant Nabs, the subsequent development of posttransplant Nabs was associated with both T cell-mediated rejection (OR 3.64; 95% CI, 1.61-8.36; P = 0.0021) and mixed rejection (OR 3.10; 95% CI, 1.02-9.75; P = 0.0473). Finally, elevated pre- and posttransplant Nabs combined with DSAs were associated with increased risk of composite outcomes (HR 3.97; 95% CI, 1.51-10.43; P = 0.0052) and T cell-mediated rejection (OR 7.28; 95% CI, 2.16-25.96; P = 0.0016). CONCLUSIONS: The presence of pre- and posttransplant Nabs, together with DSAs, was associated with increased risk of poor graft outcomes and rejection after renal transplantation.
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Trasplante de Riñón , Humanos , Trasplante de Riñón/efectos adversos , Estudios Retrospectivos , Trasplante Homólogo , Inmunoglobulina G , Antígenos HLA , Aloinjertos , Rechazo de Injerto , Supervivencia de InjertoRESUMEN
Cobalt chromium vanadium layered triple hydroxides have been identified as a promising electrocatalyst for seawater splitting. The insertion of vanadium as a third metal into cobalt chromium layered double hydroxides not only adds extra cationic active sites but also facilitates electronic transition from Co(II) to V(V) boosting the OER activity and suppressing the CER.
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An electrocatalyst which is suitable for use in both fresh water and real seawater electrolysis is very uncommon. In this work, we have developed a series of iron-tuned cobalt phosphates and cobalt-tuned iron phosphate solid solutions as electrocatalysts exhibiting excellent OER activities not only in freshwater but also in alkaline real seawater with a faradaic efficiency of 95%.
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The present work shows a significant enhancement of the photoelectrochemical water-splitting performance of anodic TiO(2) nanotube layers grown on low concentration (0.01-0.2 at% Ru) Ti-Ru alloys. Under optimized preparation conditions (0.05 at% Ru, 450 °C annealing) the water splitting rate of the oxide tubes could be 6-fold increased. Moreover, the beneficial effect is very stable with illumination time; this is in contrast to other typical doping approaches of TiO(2).
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TiO(2) is one of the most studied compounds in materials science. Owing to some outstanding properties it is used for instance in photocatalysis, dye-sensitized solar cells, and biomedical devices. In 1999, first reports showed the feasibility to grow highly ordered arrays of TiO(2) nanotubes by a simple but optimized electrochemical anodization of a titanium metal sheet. This finding stimulated intense research activities that focused on growth, modification, properties, and applications of these one-dimensional nanostructures. This review attempts to cover all these aspects, including underlying principles and key functional features of TiO(2), in a comprehensive way and also indicates potential future directions of the field.