Photoferroelectric thin films for flexible systems by a three-in-one solution-based approach

The effective incorporation of (multi)functional oxides into next-generation flexible electronics systems requires novel fabrication technologies that enable the direct integration of crystalline oxide layers in them. Unfortunately, this is considerably challenging due to the thermal incompatibility between the crystallization temperatures of metal oxides (>600 degrees C) and the thermal stability of the flexible polymer substrates conventionally used (<400 degrees C). Here, it is shown that BiFeO(3)thin films can be grown on flexible plastic by solution processing involving three different but complementary strategies to induce the crystallization of the perovskite phase at a lower temperature limit of 325 degrees C. This "three-in-one" approach is based on the synthesis of tailored metal precursors i) with a molecular structure resembling the crystalline structure of the oxide phase, which additionally allows both ii) photochemical and iii) internal combustion reactions taking place in the thin films. The flexible BiFeO(3)thin films obtained from a specifically designed molecular complex withN-methyldiethanolamine yield a large remnant polarization of 17.5 mu C cm(-2), also showing photovoltaic and photocatalytic effects. This result paves the way for the direct integration of an interesting class of oxides with photoferroelectric properties in flexible devices with multiple applications in information and communication technology, and energy

Retinoid X receptor promotes hematopoietic stem cell fitness and quiescence and preserves hematopoietic homeostasis

Hematopoietic stem cells (HSCs) balance self-renewal and differentiation to maintain hematopoietic fitness throughout life. In steady-state conditions, HSC exhaustion is prevented by the maintenance of most HSCs in a quiescent state, with cells entering the cell cycle only occasionally. HSC quiescence is regulated by retinoid and fatty-acid ligands of transcriptional factors of the nuclear retinoid X receptor (RXR) family. Herein, we show that dual deficiency for hematopoietic RXRα and RXRβ induces HSC exhaustion, myeloid cell/megakaryocyte differentiation, and myeloproliferative-like disease. RXRα and RXRβ maintain HSC quiescence, survival, and chromatin compaction; moreover, transcriptome changes in RXRα;RXRβ-deficient HSCs include premature acquisition of an aging-like HSC signature, MYC pathway upregulation, and RNA intron retention. Fitness loss and associated RNA transcriptome and splicing alterations in RXRα;RXRβ-deficient HSCs are prevented by Myc haploinsufficiency. Our study reveals the critical importance of RXRs for the maintenance of HSC fitness and their protection from premature aging

Retinoid X receptor promotes hematopoietic stem cell fitness and quiescence and preserves hematopoietic homeostasis.

Hematopoietic stem cells (HSCs) balance self-renewal and differentiation to maintain hematopoietic fitness throughout life. In steady-state conditions, HSC exhaustion is prevented by the maintenance of most HSCs in a quiescent state, with cells entering the cell cycle only occasionally. HSC quiescence is regulated by retinoid and fatty-acid ligands of transcriptional factors of the nuclear retinoid X receptor (RXR) family. Here, we show that dual deficiency for hematopoietic RXRa and RXRb induces HSC exhaustion, myeloid cell/megakaryocyte differentiation, and myeloproliferative-like disease. RXRa and RXRb maintain HSC quiescence, survival, and chromatin compaction; moreover, transcriptome changes in RXRa;RXRb-deficient HSCs include premature acquisition of an aging-like HSC signature, MYC pathway upregulation, and RNA intron retention. Fitness loss and associated RNA transcriptome and splicing alterations in RXRa;RXRb-deficient HSCs are prevented by Myc haploinsufficiency. Our study reveals the critical importance of RXRs for the maintenance of HSC fitness and their protection from premature aging.We thank the members of the J.A.C. and M.R. laboratories for extensive discussions and critiques of the manuscript. We thank Daniel Metzger (Université de Strasbourg, France) for Rxrbf/f 418 mice, Juan Carlos Zúñiga-Pflücker (Sunnybrook Health Sciences Centre, Canada) for OP9-NL1 cells, Daniel Jiménez-Carretero (CNIC) for t-SNE analysis, the CRG (Barcelona, Spain) Genomics Unit for ATACseq sequencing, and S. Bartlett (CNIC) for editorial assistance. We also thank the staff of the CNIC Cellomics and Animal facilities for technical support. This study was supported by grants from the Spanish Ministerio de Ciencia e Innovación (MICIN) (SAF2017-90604-REDT-NurCaMein, RTI2018- 095928-B100, and PID2021-122552OB-I00), La Marató de TV3 Foundation (201605-32), and the Comunidad de Madrid (MOIR-B2017/BMD-3684) to M.R and from the Formación de Profesorado Universitario (FPU17/01731) program (MICIN) to J.P. The project also received funding from the US National Institutes of Health (R01 DK124115, P01 HL158688, R01 HL147536, R01 CA237016 and U54 DK126108 to J.A.C). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación (MCIN), and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence (grant CEX2020-001041-S funded by MICIN/AEI/10.13039/501100011033).S

Photochemical solution processing of films of metastable phases for flexible devices: the beta-Bi2O3 polymorph

The potential of UV-light for the photochemical synthesis and stabilization of non-equilibrium crystalline phases in thin films is demonstrated for the beta-Bi2O3 polymorph. The pure beta-Bi2O3 phase is thermodynamically stable at high temperature (450-667 degrees C), which limits its applications in devices. Here, a tailored UV-absorbing bismuth(III)-N-methyldiethanolamine complex is selected as an ideal precursor for this phase, in order to induce under UV-light the formation of a -Bi-O-Bi- continuous network in the deposited layers and the further conversion into the beta-Bi2O3 polymorph at a temperature as low as 250 degrees C. The stabilization of the beta-Bi2O3 films is confirmed by their conductivity behavior and a thorough characterization of their crystal structure. This is also supported by their remarkable photocatalytic activity. Besides, this processing method has allowed us for the first time the preparation of beta-Bi2O3 films on flexible plastic substrates, which opens new opportunities for using these materials in potential applications not available until now (e.g., flexible photocatalytic reactors, self-cleaning surfaces or wearable antimicrobial fabrics). Therefore, photochemical solution deposition (PCSD) demonstrates to be not only an efficient approach for the low temperature processing of oxide films, but also an excellent alternative for the stabilization of metastable phases

Water intake, hydration status and 2-year changes in cognitive performance: a prospective cohort study

BackgroundWater intake and hydration status have been suggested to impact cognition; however, longitudinal evidence is limited and often inconsistent. This study aimed to longitudinally assess the association between hydration status and water intake based on current recommendations, with changes in cognition in an older Spanish population at high cardiovascular disease risk.MethodsA prospective analysis was conducted of a cohort of 1957 adults (aged 55-75) with overweight/obesity (BMI between >= 27 and = 300 mmol/L (dehydrated). Water intake was assessed as total drinking water intake and total water intake from food and beverages and according to EFSA recommendations. Global cognitive function was determined as a composite z-score summarizing individual participant results from all neuropsychological tests. Multivariable linear regression models were fitted to assess the associations between baseline hydration status and fluid intake, continuously and categorically, with 2-year changes in cognitive performance.ResultsThe mean baseline daily total water intake was 2871 +/- 676 mL/day (2889 +/- 677 mL/day in men; 2854 +/- 674 mL/day in women), and 80.2% of participants met the ESFA reference values for an adequate intake. Serum osmolarity (mean 298 +/- 24 mmol/L, range 263 to 347 mmol/L) indicated that 56% of participants were physiologically dehydrated. Lower physiological hydration status (i.e., greater serum osmolarity) was associated with a greater decline in global cognitive function z-score over a 2-year period (beta: - 0.010; 95% CI - 0.017 to - 0.004, p-value = 0.002). No significant associations were observed between water intake from beverages and/or foods with 2-year changes in global cognitive function.ConclusionsReduced physiological hydration status was associated with greater reductions in global cognitive function over a 2-year period in older adults with metabolic syndrome and overweight or obesity. Future research assessing the impact of hydration on cognitive performance over a longer duration is needed

One-year longitudinal association between changes in dietary choline or betaine intake and cardiometabolic variables in the PREvención con DIeta MEDiterránea-Plus (PREDIMED-Plus) trial

Choline and betaine intakes have been related to cardiovascular health. We aimed to explore the relation between 1-y changes in dietary intake of choline or betaine and 1-y changes in cardiometabolic and renal function traits within the frame of the PREDIMED (PREvención con DIeta MEDiterránea)-Plus trial. We used baseline and 1-y follow-up data from 5613 participants (48.2% female and 51.8% male; mean ± SD age: 65.01 ± 4.91 y) to assess cardiometabolic traits, and 3367 participants to assess renal function, of the Spanish PREDIMED-Plus trial. Participants met ≥3 criteria of metabolic syndrome and had overweight or obesity [BMI (in kg/m 2) ≥27 and ≤40]. These criteria were similar to those of the PREDIMED parent study. Dietary intakes of choline and betaine were estimated from the FFQ. The greatest 1-y increase in dietary choline or betaine intake (quartile 4) was associated with improved serum glucose concentrations (−3.39 and −2.72 mg/dL for choline and betaine, respectively) and HbA1c levels (−0.10% for quartile 4 of either choline or betaine intake increase). Other significant changes associated with the greatest increase in choline or betaine intake were reduced body weight (−2.93 and −2.78 kg, respectively), BMI (−1.05 and −0.99, respectively), waist circumference (−3.37 and −3.26 cm, respectively), total cholesterol (−4.74 and −4.52 mg/dL, respectively), and LDL cholesterol (−4.30 and −4.16 mg/dL, respectively). Urine creatinine was reduced in quartile 4 of 1-y increase in choline or betaine intake (−5.42 and −5.74 mg/dL, respectively). Increases in dietary choline or betaine intakes were longitudinally related to improvements in cardiometabolic parameters. Markers of renal function were also slightly improved, and they require further investigation. This trial was registered at as ISRCTN89898870

Photoferroelectric thin films for flexible systems by a three-in-one solution-based approach

The effective incorporation of (multi)functional oxides into next-generation flexible electronics systems requires novel fabrication technologies that enable the direct integration of crystalline oxide layers in them. Unfortunately, this is considerably challenging due to the thermal incompatibility between the crystallization temperatures of metal oxides (>600 degrees C) and the thermal stability of the flexible polymer substrates conventionally used (<400 degrees C). Here, it is shown that BiFeO(3)thin films can be grown on flexible plastic by solution processing involving three different but complementary strategies to induce the crystallization of the perovskite phase at a lower temperature limit of 325 degrees C. This "three-in-one" approach is based on the synthesis of tailored metal precursors i) with a molecular structure resembling the crystalline structure of the oxide phase, which additionally allows both ii) photochemical and iii) internal combustion reactions taking place in the thin films. The flexible BiFeO(3)thin films obtained from a specifically designed molecular complex withN-methyldiethanolamine yield a large remnant polarization of 17.5 mu C cm(-2), also showing photovoltaic and photocatalytic effects. This result paves the way for the direct integration of an interesting class of oxides with photoferroelectric properties in flexible devices with multiple applications in information and communication technology, and energy

Low-temperature sol–gel methods for the integration of crystalline metal oxide thin films in flexible electronics

The development of low-temperature sol–gel (solution) processes for the fabrication of crystalline metal oxide thin films has become a key objective in the emerging Flexible Electronics. To achieve this target, crystalline oxide films need to be deposited on flexible substrates, which have degradation temperatures below 350 °C (e.g., polymers or textile). This achievement would be a step towards improving the performance of the flexible device, making feasible applications now restrained (e.g. smart-skin, flexible-displays or solar-cells) and whose performance is associated to the functional properties of the crystalline oxide (e.g., ferroelectricity, pyroelectricity or piezoelectricity). However, this is a challenge because the crystallization of these oxides usually occurs at high temperatures, over 600 °C. This paper shows an overview to the solution strategies devised in our group for the low-temperature fabrication of crystalline metal oxide thin films, mostly ferroelectric perovskites (e.g., BiFeO3, PbTiO3 or Pb(Zr,Ti)O3). We have made use of UV-light as an alternative energy source to the thermal energy conventionally used to obtain the crystalline oxide. High photosensitive sol–gel solutions have been synthesized and the solution-deposited layers irradiated with UV-excimer lamps. A precise control of the photoreactions occurring during the irradiation of these layers has been carried out with the aim of advancing the formation of a high-densified, defect-free amorphous metal oxide film that easily can be converted into crystalline at temperatures compatible with the use of polymer substrates

Low-temperature sol–gel methods for the integration of crystalline metal oxide thin films in flexible electronics

The development of low-temperature sol–gel (solution) processes for the fabrication of crystalline metal oxide thin films has become a key objective in the emerging Flexible Electronics. To achieve this target, crystalline oxide films need to be deposited on flexible substrates, which have degradation temperatures below 350 °C (e.g., polymers or textile). This achievement would be a step towards improving the performance of the flexible device, making feasible applications now restrained (e.g. smart-skin, flexible-displays or solar-cells) and whose performance is associated to the functional properties of the crystalline oxide (e.g., ferroelectricity, pyroelectricity or piezoelectricity). However, this is a challenge because the crystallization of these oxides usually occurs at high temperatures, over 600 °C. This paper shows an overview to the solution strategies devised in our group for the low-temperature fabrication of crystalline metal oxide thin films, mostly ferroelectric perovskites (e.g., BiFeO3, PbTiO3 or Pb(Zr,Ti)O3). We have made use of UV-light as an alternative energy source to the thermal energy conventionally used to obtain the crystalline oxide. High photosensitive sol–gel solutions have been synthesized and the solution-deposited layers irradiated with UV-excimer lamps. A precise control of the photoreactions occurring during the irradiation of these layers has been carried out with the aim of advancing the formation of a high-densified, defect-free amorphous metal oxide film that easily can be converted into crystalline at temperatures compatible with the use of polymer substrates