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Hypobaric hypoxia causes oxidative stress and inflammatory responses and disrupts the gut microbiome and metabolome. In this study, we developed a synbiotic fermented whey beverage, combining kefir and Brassica rapa L. crude polysaccharides, to explore its protective effects against high-altitude induced injury in mice. The beverage, formulated with 0.8% (w/v) polysaccharides and kefir inoculation, demonstrated robust fermentation parameters and antioxidative capacity. When applied to a hypobaric hypoxia mouse model, the synbiotic fermented whey significantly reduced oxidation and protected the intestinal barrier by lowering inflammation, protecting the intestinal structure, increasing goblet cell counts, and reducing apoptosis. It also modulated the gut microbiota, enriching beneficial taxa as Intestinimonas and Butyricicoccaceae , while reducing harmful ones like Marvinbryantia and Proteus , and enhancing short-chain fatty acid (SCFA) production. Notably, the beverage increased berberine and nicotinic acid levels, activating the adenosine monophosphate-activated protein kinase (AMPK) signalling pathway and influencing nicotinate and nicotinamide metabolites linked to the suppression of Marvinbryantia , thereby alleviating intestinal inflammation and barrier damage. These effects contributed to the alleviation of hypoxia-induced intestinal damage in mice. This study highlights the potential of synbiotics and whey fermentation in novel nutritional interventions in high altitude environments.

Wearable devices hold significant potential in healthcare and medical diagnostics. One major challenge in realizing this potential is the low barrier property of polymer substrates, which fail to withstand surrounding moisture and biofluids. In this work, a two-step strategy involving ALI followed by a UV-curing process is developed to fabricate a K 48 PDMS/Al 2 O 3 ultra-barrier with high barrier property of 7.82 × 10 -5 g m -2 day -1 under stretching strain, representing one of the highest values among current works. Moreover, the K 48 PDMS/Al 2 O 3 barrier enables Ca-tested devices to exhibit extended operational lifetimes of up to 12 days in simulated rain. It also ensures the high sensitivity of strain sensors for real-time monitoring of health-related physiological signals, even when exposed to aggressive solutions such as PBS, KOH, and glucose. A clear "filling-cross-linking" mechanism is revealed, involving the filling of the void spaces within polymer chains followed by the cross-linking of polymer side chains to enhance the density of the hybrid layer. Adjusting porosity and functional group density ensures complete Al 2 O 3 infiltration into the polymer. The cross-linking increases from 12.31% to 73.79% compared to the UV-curing process alone due to the presence of Al 2 O 3 , further enhancing the density of the hybrid layer and its barrier properties. The proposed strategy in our work shows great potential for providing highly reliable encapsulation for wearable electronics.

The challenge of developing phosphors with tailored near-infrared (NIR) emission ranges to meet the diverse demands of various applications is a paramount concern in the contemporary realm of NIR phosphor research. A strong dependence of NIR emission on Cr 3+ concentration has been demonstrated in Sc 2- x Si 2 O 7 : x Cr 3+ , which exhibits an NIR emission band at 840 nm for low Cr 3+ doping concentrations ( x = 0.001-0.01) and an anomalous NIR emission band at 1300 nm for high Cr 3+ doping concentrations ( x = 0.01-0.10). Careful investigation of the crystal structure, excitation and emission spectra, and luminescence decay curves indicates that the two NIR emissions can be attributed to the isolated Cr 3+ ions and the Cr 3+ -Cr 3+ pairs, respectively. The strong interaction of exchange-coupled Cr 3+ -Cr 3+ pairs is supported by temperature-dependent emission spectra, luminescence decay curves and electron paramagnetic resonance (EPR) measurements. This work provides a new insight into the study of Cr 3+ -Cr 3+ pairs for broadband NIR emission.

The discovery of phosphors with highly efficient broadband near-infrared emission is urgent for constructing NIR sources for various applications. Herein, we synthesized a series of near-infrared emitting garnet-type (A 3 B 2 C 3 O 12 ) Lu 2- x CaAl 3.99 Cr 0.01 SiO 12 : x Gd/La and Lu 2 CaAl 3.99- y Cr 0.01 SiO 12 : y Sc/Ga phosphors and systematically investigated the effect of A/B-site substitution on the crystal structure and luminescence properties. Structural and optical analyses revealed that the A/B-site substitution weakened the crystal field strength, further enhancing the broadband emission of the allowed 4 T 2 → 4 A 2 transition and diminishing the narrow-peak emission of the forbidden 2 E → 4 A 2 transition. As expected, NIR phosphors, exemplified by Lu 1.7 CaAl 3.99 Cr 0.01 SiO 12 :0.3Gd and Lu 2 CaAl 3.49 Cr 0.01 SiO 12 :0.5Sc, showed outstanding thermal stabilities at 423 K (150 °C) registering values of 103.02% and 94.91%, with high quantum efficiencies of 80.48% and 85.01%, respectively. In addition, pc-LEDs with broadband NIR output and good optoelectronic properties have been realized, demonstrating the great potential of broadband NIR pc-LEDs for applications. This work not only provides a series of high-efficiency phosphors for NIR pc-LED applications, but also provides a systematic idea and an efficient method to improve the luminescence performance of garnet-type phosphors.

Near-infrared (NIR) phosphors with high thermal stability are significant for NIR light-emitting diodes (LEDs). For a decade, Debye temperature has been a successful indicator of structural rigidity and thermal stability for phosphors, but some exceptions exist due to its dependence on atomic mass. Inspired by the Debye temperature model that relates the elastic properties of solids, our density functional theory calculations revealed that the Vickers hardness of Cr 3+ -doped NIR phosphors was negatively correlated with Stokes shifts (Pearson's R = -0.81) and positively correlated with thermal stabilities (Pearson's R = 0.85) within a set of 13 distinct material types. Highlighting the predictive power of Vickers hardness, two new NIR phosphors were investigated: KMg(PO 3 ) 3 :Cr 3+ showed low thermal stability, correlating with its lower Vickers hardness, in contrast to the high thermal stability and correspondingly higher Vickers hardness of La 2 MgSnO 6 :Cr 3+ . Vickers hardness can be used to screen potential hosts for Cr 3+ -doped NIR phosphors with high thermal stabilities, due to the advantages of the predictable feature by density functional theory calculation and low independence on atomic mass.

The luminescence efficiency and thermal stability are enduring topics in the realm of phosphors. It is acknowledged that the structural transformation from disorder to order results in increased lattice rigidity, consequently inducing heightened efficiency and enhanced thermal stability. In this case study of the structural evolution of Ca 3 Ga 2 Ge 4 O 14 :Cr 3+ , NaCa 2 GaGe 5 O 14 :Cr 3+ and Na 2 CaGe 6 O 14 :Cr 3+ near-infrared (NIR) phosphors, a significant paradox is revealed: the incongruent relationship between the fluctuating degrees of disorder and the simultaneous improvements in efficiency and thermal stability. By drawing on insights gained from structural analysis, optical investigations, and theoretical calculations, a notable revelation surfaces: the primary factor affecting rigidity and optical performance is not the disordering of the entire lattice, but rather the disordering of the framework itself. The findings elucidate the principle of framework-order engineering for crafting high-performance NIR phosphors.

The trimester-specific associations of maternal dietary patterns with preterm birth (PTB) are unclear. In a prospective prebirth cohort study, we aimed to examine the critical time window of maternal prenatal dietary patterns and the risk of PTB. We assessed prenatal dietary intake among 1500 pregnant women with validated food frequency questionnaires during the 1 st , 2 nd and 3 rd trimester, respectively. We used logistic regression models and generalized estimating equation models to examine the trimester-specific associations and longitudinal associations between maternal dietary patterns in relation to risk of PTB and PTB subtypes. The incidence rate of PTB was 11.9% (179 out of 1500 pregnant women) in the present study. We observed that maternal adherence to a fish-seafood pattern in the 1 st trimester was associated with higher risk of PTB [tertile 3 (T3) vs. tertile 1 (T1): OR = 2.29, 95% CI: 1.32-3.96] and iatrogenic preterm birth (IPTB) (T3 vs. T1: OR = 2.26, 95% CI: 1.21-4.20), while a fish-seafood pattern in the 2 nd trimester was associated with lower risk of PTB (T3 vs. T1: OR = 0.49, 95% CI: 0.25-0.93). Maternal adherence to a dairy-egg pattern in the 2 nd or 3 rd trimester was associated with higher risks of PTB and IPTB. No dietary patterns were associated with spontaneous preterm birth. Our findings provide new evidence that specific dietary patterns during different trimesters may have different and even inverse health effects on pregnant women. This supports the necessity of guiding the maternal diet according to different periods of pregnancy to prevent PTB.

Improving the efficiency of the anodic oxygen evolution reaction (OER) is important to solve the global energy crisis and greenhouse gas emission problems. In this paper, a preparation method for a MIL-53(Fe)@ZIF-67(Co) composite electrode is proposed. The hierarchical structure formed by the combination of MIL-53(Fe) and ZIF-67(Co) provides a rich channel for the transport of electrons and mass in the OER process. XPS analysis and DFT calculations revealed that Fe electrons in MIL-53(Fe) were transferred to Co in ZIF-67(Co) through O, which confirmed the rapid charge transfer effect of this transport channel. The MIL-53(Fe)@ZIF-67(Co) electrode has significant OER performance. When the current density reaches 10 mA cm -2 , the overpotential is only 193 mV. This study inaugurates a new way for the rational design of a multiphase interface and the construction of new MOF channel structures.

Resistive random access memory has been widely studied as a powerful candidate for building future memories and realizing high-efficiency artificial neuromorphic systems. In this paper, gold nanoparticles (Au NPs) are doped in a leaf solution of Scindapsus aureus (SA) as the active layer to fabricate Al/SA:Au NPs/ITO/glass resistive random access memory. The device exhibits stable bipolar resistance switching characteristics. More importantly, the device's multilevel storage capabilities and synaptic potentiation and depression behaviour have been proven. Compared with the device without doped Au NPs in the active layer, the device has a higher ON/OFF current ratio, which is attributed to the Coulomb blockade effect caused by the Au NPs. The device plays an important role in realizing high-density memory and efficient artificial neuromorphic systems.

The application of heteroatom-doped graphene for photochemical and electrochemical reactions is primarily hindered by the lack of a controllable and facile synthesis strategy. In this work, few-layer CoN-graphene (1.8 nm thickness) with atomic Co has been fabricated via pyrolysis exfoliation. The half wave potential of CoN-graphene reaches 0.875 V vs. RHE, and the corresponding direct methanol fuel cell performance is 100% (higher than that of the commercial Pt/C catalyst), demonstrating potential for practical application in energy conversion devices.

Mixed-valence europium-activated phosphors are receiving attention in many fields, such as lighting, anti-counterfeiting, optical recording, encryption, and temperature sensing. However, it remains difficult to construct mixed-valence europium-activated compounds due to the reductive and oxidative synthesis conditions required to obtain Eu 2+ and Eu 3+ ions, respectively. Herein, mixed-valence Eu 2+ /Eu 3+ was realized in the CaBPO 5 built by rigidly connected BO 4 and PO 4 tetrahedrons by partial Eu 3+ → Eu 2+ self-reduction in the air atmosphere. Commendably, the CaBPO 5 :Eu 2+ /Eu 3+ phosphor exhibits excellent ratiometric temperature sensing performance with the maximum absolute and relative sensitivity being as high as 0.184 K -1 and 3.444% K -1 with good signal discriminability, due to the high and low, respectively, temperature-dependence of Eu 2+ and Eu 3+ emissions. The rapid dropping intensity of Eu 2+ in CaBPO 5 with increasing temperature was due to the small energy gap (∼0.48 eV) between the Eu 2+ -5d state and the conduction band. Our work not only provides a novel thermometer candidate but also enlightens researchers to a method of effectively designing new mixed-valence metal-ion activated luminescent thermometers via selective tetrahedrally coordinated rigid crystal structure.

Considerable efforts have been devoted to the development of visible light-emitting phosphors for anti-counterfeiting application, but the design of multifunctional near-infrared materials with suitable luminescent properties was lacking. Based on the crystal field theory, a near ultraviolet excitable and near-infrared emitting Ca 2 Sn 2(1- x ) Al 2(1- x ) O 9 :2 x Cr 3+ ,2 x Si 4+ phosphor was designed. On the one hand, the Ca 2 Sn 2(1- x ) Al 2(1- x ) O 9 :2 x Cr 3+ ,2 x Si 4+ phosphor showed great potential for applications including anti-counterfeiting and secret signals under a 405 nm near UV laser. The integrated intensity at 150 °C was 75.9%, implying high thermal stability when irradiated with a high power light source. On the other hand, an unexpected red emission component originating from the Cr 3+ -Cr 3+ dimer was observed and was confirmed by fast luminescence decay and electron spin resonance signals. The different thermal stabilities of Cr 3+ near-infrared and Cr 3+ -Cr 3+ red emissions opened up a new opportunity for luminescence ratiometric thermometers.

Designing and developing earth-abundant electrocatalysts for the oxygen evolution reaction (OER) in alkaline media is a critical element in the societal development of sustainable energy. MIL-53(Fe-Ni)/NF-2200Gs was synthesized under an external magnetic field. Such MIL-53(Fe-Ni)/NF-2200Gs show exceptionally high catalytic activity and require an overpotential of only 174 mV to drive a geometrical catalytic current density of 10 mA cm -2 in 1.0 M KOH, superior to RuO 2 and most Fe, Ni-based electrocatalysts. Our work emphasizes the optimization of catalytic activity originating from the improvement of the magnetic properties of the catalyst, which enhances the spin polarization and tailors the d-electron structure of cations, leading to outstanding OER activity. This work would open new opportunities to design and develop transition-metal-based nanometer arrays toward efficient and stable water oxidation in alkaline media for applications., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The construction of functionalized covalent organic frameworks (COFs) is of great significance for broadening their potential applications, but is yet challenging to achieve, especially for three-dimensional (3D) COFs, because the connection of the building organic skeleton must strictly follow the pre-designed topology. Here we present the synthesis of two diamondyne-like 3D COFs (CPOF-2 and CPOF-3) functionalized with acetylene (-CC-) and diacetylene (-CC-CC-), respectively. The obtained COFs show a high crystallinity, permanent porosity, and chemical stability. Furthermore, CPOF-3 exhibited an extremely high volatile iodine uptake (as high as 5.87 g g -1 ), much higher than that of most reported COF-based adsorbents for iodine capture. Therefore, this study provides a new design principle to obtain high-performance iodine loading porous materials to solve the environmental pollution problem caused by radioactive iodine in the waste of the nuclear industry.

In multiphase materials, structured fluid-fluid interfaces can provide mechanical resistance against destabilization, applicable for conformance control, Pickering emulsion, liquid 3D printing and molding, etc. Currently all research prepare the particle-ladened fluid-fluid interfaces by dispersing ex situ acquired particles to the immiscible interface, which limits their application in the harsh environment, such as oil reservoir which can impair particle stability and transport ability. Here, we investigated the interfacial and assembly properties of the interface where SiO 2 nanoparticles (NPs) were in situ produced. The experimental results show that ammonia as catalyst could accelerate the processes of silica NPs formation as well as the interfacial tension (IFT) evolution. High temperature could not accelerate the reaction processes to achieve the lowest equilibrium IFT, but it induced the sine-wave IFT evolution curves regardless of the presence of ammonia. The equilibrium IFTs corresponded to the saturation states of interfaces trapping with SiO 2 NPs, while the sine-wave fluctuating patterns of IFT were attributed to the alternating transition between interfacial jammed and unjammed states changing along with the reaction process. Silica NPs diffusing into aqueous phase with high salinity also showed good stability, due to the abundant surface decoration with in situ anchored organic species., Competing Interests: The authors declare no competing financial interest., (This journal is © The Royal Society of Chemistry.)

Ce 3+ and Eu 2+ doped and Ce 3+ -Eu 2+ co-doped Sr 2 MgSi 2 O 7 phosphors are prepared via a high-temperature solid-state reaction technique. The synchrotron radiation vacuum ultraviolet-ultraviolet (VUV-UV) excitation and ultraviolet-visible (UV-vis) emission spectra of diluted Ce 3+ and Eu 2+ doped Sr 2 MgSi 2 O 7 samples are measured at cryogenic temperatures. The electron-vibrational interaction (EVI) between Ce 3+ and its surroundings is analyzed. The dependencies of the 4f-5d transitions of Ce 3+ on the structure of the host compounds Sr 2 MgSi 2 O 7 , Ba 2 MgSi 2 O 7 and BaMg 2 Si 2 O 7 are discussed in detail. Then the thermal quenching channel is proposed based on the measurements of temperature dependent luminescence intensities and decay times of Ce 3+ and Eu 2+ in Sr 2 MgSi 2 O 7 , and the Ce 3+ → Eu 2+ energy transfer mechanism is understood by three luminescence dynamic models. In addition, Sr 2 MgSi 2 O 7 :Ce 3+ /Eu 2+ samples are evaluated for the possibilities of X-ray detection applications using X-ray excited luminescence (XEL) spectroscopy, and it was found that they are not suitable.

Improving the utilization of noble metals is extremely urgent for fuel cell electrocatalysis, while three-dimensional hierarchical noble metal aerogels with abundant sites and channels are proposed to reinforce their electrocatalytic performances and decrease their amounts. Herein, novel Pd aerogels with tunable surface chemical states were prepared through a facile in situ electrochemical activation, starting with PdO x aerogels by the hydrolysis method. The hierarchical porous Pd aerogels showed unprecedented high activity towards the electrocatalytic oxidation of fuels including methanol (2.99 A mg Pd -1 ), ethanol (8.81 A mg Pd -1 ), and others in alkali, outperforming commercial catalysts (7.12- and 13.66-fold, corresponding to methanol and ethanol). Theoretical investigation unveiled the hybrid surface states with metallic and oxidized Pd species in Pd aerogels to regulate the adsorption of intermediates and facilitate the synergistic oxidation of adsorbed *CO, resulting in enhanced activity with the MOR as the model. Therefore, efficient Pd aerogels through the in situ electrochemical activation of PdO x aerogels were proposed and showed great potential for fuel cell anodic electrocatalysis., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Currently, π-conjugated [B 2 O 5 ] moieties are rarely studied for designing deep-UV birefringent crystals. Here, we report a new deep-UV birefringent crystal Ba 2 Zn 2 B 6 O 13 with a deep-UV cut-off edge of 190 nm and large birefringence (Δ n = 0.085@ 532 nm), indicating that it can be used as the birefringent material in the DUV area. The first-principles calculation analyses suggest that its large birefringence mainly originates from the coplanar [B 2 O 5 ] dimers in the unnoted U-shaped [B 6 O 13 ].

The phosphate interphase of anisotropic amorphous vanadium oxide (VO-PO@CNPs) can prevent structural reorganization and enrich ion diffusion paths in cathode materials for aqueous zinc ion batteries. VO-PO@CNPs cathodes achieve a high initial capacity, the average capacity reduction rate is just 0.13% for each cycle, and durability is prolonged to 280 hours at 0.2 A g -1 .

A palladium-catalyzed Heck/carbonylative cyclization process has been explored for the synthesis of functionalized amides. By using nitroarenes as readily accessible nitrogen sources, a variety of amide products were obtained in moderate to excellent yields with good functional group compatibility. Furthermore, a late-stage modification of a natural molecule is also achieved by this protocol.

A simple and rapid simultaneous sensing strategy of multiple biomarkers is of great importance but challenging in health diagnosis. In this study, a novel free-standing edge-rich graphene film (fs-ERG) was in situ fabricated via a facile chemical vapor deposition route on a porous Si 3 N 4 substrate. The subsequent superhydrophilic modification of the fs-ERG not only makes it maintain the original abundant edge-rich sites, high conductivity, and hierarchical porosity, but also endows it with collective electrochemical characteristics. Thereafter, the superhydrophilic fs-ERG (S-fs-ERG) demonstrated a fast electron-transfer kinetics towards the oxidation of dopamine (DA), ascorbic acid (AA), and uric acid (UA), which promised a sensitive simultaneous electrochemical determination with low detectable limits of 0.1, 2.5 and 0.5 μM, respectively. Furthermore, this sensing electrode displayed high selectivity in the presence of co-existing interferences as well as excellent reproducibility, and thus performed well in DA, AA and UA detection in real samples. These superior sensing performance metrics combined with the low-cost and scalable fabrication of S-fs-ERG based electrodes bode well for their great potential for the simultaneous and disposable sensing of DA, AA and UA in practical application.

Recently, molecules with aggregation-induced luminescence (AIE) characteristics have received more and more attention due to the fluorescence of traditional dyes being easily quenched in the aggregated state. AIE molecules have significant advantages, such as excellent light stability, bright fluorescence, high contrast, and large Stokes shift. These characteristics have aroused wide interest of researchers and opened up new applications in many fields, especially in the field of biological applications. However, AIE molecules or their aggregates have certain limitations in multifunctional biological research due to their low specific targeting ability, poor biocompatibility, and poor stability in physiological body fluids. In order to overcome these problems, a novel nanoparticle, FFM1, was fabricated and characterized. FFM1 displayed good water solubility, biocompatibility, and AIE emission properties. It could target HeLa cells specifically by recognizing their folate receptor. Reactive oxygen triggered by light irradiation induced tumor cell apoptosis. Summarily, FFM1 displayed excellent capacity in target imaging and photodynamic killing of HeLa cells. It has shown potential application value in targeted diagnosis and photodynamic therapy of tumors, and has important guiding significance for the treatment of malignant tumors. It paves a way for the development of a novel strategy for tumor theranostics., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Polymer substrates with superior barrier properties are of great importance for the development of highly-stable flexible displays. The atomic layer infiltration (ALI) method has been utilized to integrate nanoscale inorganic materials in the subsurface of commercial PEN substrates, and the in-suit quartz crystal microbalance (QCM) is employed to study the growth behaviour as the process parameters vary, in which the nucleation and infiltration stages have been demonstrated. The O 2 plasma pre-treatment prior to Al 2 O 3 infiltration was used to determine its effect on the water vapor transmission rate (WVTR), and significantly improved barrier properties were observed compared to those of the ones without the O 2 plasma pre-treatment via the electrical Ca tests, which was attributed to the surface clean and improved film adhesion. The lowest WVTR value measured was 1.28 × 10 -5 g m -2 day -1 for the O 2 plasma pre-treated PEN substrate coated with 100 ALI cycles, which improved 3-4 orders of magnitude compared to that of the pristine ones. Besides, the infiltrated PEN substrate with O 2 plasma pre-treatment exhibited good mechanical stability, with only a slight increase of the WVTR value which was observed after the bending fatigue test with a radius of 5 mm. Furthermore, when applied to the encapsulation of organic light-emitting diodes (OLEDs), the normalized luminance remained above 94% after storage for 800 hours.

The speed with which electronic products are updated is continuously increasing. Consequently, since waste electronic products can cause serious environmental pollution, the demand for electronic products made of biological materials is becoming increasingly urgent. Although biological memristors have significant advantages, their electrical characteristics still do not meet the requirements to be used in future nonvolatile memories. Therefore, how to control their electrical characteristics has become a popular topic of research. In this study, tunable biomemristors with an Al/tussah blood (TB)-carbon nanotube (CNT)/indium tin oxide (ITO)/glass structure were fabricated. Such a device exhibits stable bipolar resistance switching behavior and good retention characteristics (10 4 s). Experimental results show that the ON/OFF current ratio can be effectively controlled by modifying the CNT concentration in the TB-CNT composite film. Multilevel (8 levels, 3 bits per cell) storage capabilities can be achieved in the device by controlling its compliance current in order to achieve high-density storage. The resistance switching behavior originates from the formation and rupture of conductive oxygen vacancy filaments. TB is a promising natural biomaterial in the field of green electronics, and this research could blaze a new trail for the development of biological memory devices. Biomemristors with multilevel resistance states can be used as electronic synapses and are one of the choices for simulating biological synapses.

A series of new organic hybrid polyoxovanadate clusters [V 4 O 4 (μ-OH) 2 (acac) 2 (Htri) 2 ] (1, H 3 tri = tris(hydroxymethyl) aminomethane, acac = acetylacetone), [V 4 O 4 (acac) 2 (Htri) 2 (L) 2 ] {HL = methanol (2), ethanol (3a and 3b), ethylene glycol (4) and benzyl alcohol (5)}, {V 4 O 4 (H 2 O) 2 (tri-acetamide) 2 (CH 3 COO) 2 } (6, H 3 tri-acetamide = N -(2-hydroxy-1,1-bis-hydroxymethyl-ethyl)-acetamide), [V 6 O 8 (μ-OH) 2 (Htri) 3 ]·6H 2 O (7) and [V 14 O 18 (tri) 2 (Htri) 6 (HCOO)(CH 3 COO)]·2H 2 O (8) were prepared by hydro(solvo)thermal methods and characterized structurally. 1 contains [VO(OH)(acac)] and [VO 2 (Htri)] units, which are further interconnected via common edges to build a tetravanadyl cluster [V 4 O 4 (OH) 2 (acac) 2 (Htri) 2 ] with the double-deficient cube [V 4 O 6 ]. The tetravanadyl cluster frameworks of 2-5 can be derived from the tetravanadyl cluster of 1 by replacing two -OH groups with two deprotonated organic alcohol ligands, namely, CH 3 O - (2), CH 3 CH 2 O - (3a and 3b), HO(CH 2 ) 2 O - (4) and C 6 H 5 CH 2 O - (5). Interestingly, both 3a and 3b have the same chemical structure, but they exhibit different conformational polymorphisms [denoted as α-type (3a) and β-type (3b)]. Such conformational polymorphisms within the polyoxovanadate clusters incorporating tris(hydroxymethyl)methane derivatives emerged for the first time. 6 displays another tetravanadyl cluster {V 4 O 4 (H 2 O) 2 (tri-acetamide) 2 (CH 3 COO) 2 } with a [V 4 O 16 ] fragment, where the tri-acetamide unit comes from the amidation reaction of H 3 tri and acetic acid and caps the tetrahedral void of the tetravanadyl cluster. The polyoxovanadate cluster of 7 can originate from the Lindqvist-type hexavanadyl cluster [V 6 O 19 ] by replacing nine μ-oxides with nine alkoxides of three tri-acetamide 3- ligands. 8 exhibits a fully reduced tetradecavanadyl cluster based on the linkage of two heptavanadyl clusters via two O bridges. The magnetic properties of 1-8 show typical antiferromagnetic interactions.

Hydrolysed polyacrylamide (HPAM) is widely used in many industrial fields where its rheological properties play a leading role. Recent discovery of the reduction of HPAM's viscosity by adding carbon quantum dots (CQDs), however, is controversial to the established theories. By using all atom molecular dynamics simulation with an OPLS-AA force field, this study aims to provide detailed molecular insight into such an uncommon phenomenon. The dynamic structures of the HPAM chain in the presence or absence of CQDs were clearly captured from the molecular aspect. The results reveal that the adsorption of CQD reduces the gyration radius of the HPAM chain, and it is the corresponding hydration effect that leads to the reduction of the viscosity. The amide rather than the carboxylate group along the HPAM chain is dominant in terms of the interaction with the CQDs, and the driven atoms depend on the surface where the polymer is adsorbed., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Focused ultrasound (FU) is in demand for clinical cancer therapy, but the possible thermal injury to the normal peripheral tissues limits the usage of the ablative FU for tumors with a large size; therefore research efforts have been made to minimize the possible side effects induced by the FU treatment. Non-ablative focused ultrasound assisted chemotherapy could open a new avenue for the development of cancer therapy technology. Here, low intensity focused ultrasound (LIFU) for controlled quick intracellular release of small molecules (Mw ≤ 1000 Da) without acute cell damage is demonstrated. The release is achieved by a composite poly(allylamine hydrochloride) (PAH)/poly-(sodium 4-styrenesulfonate) (PSS)/SiO2 microcapsules which are highly sensitive to LIFU and can be effectively broken by weak cavitation effects. Most PAH/PSS/SiO2 capsules in B50 rat neuronal cells can be ruptured and release rhodamine B (Rh-B) into the cytosol within only 30 s of 0.75 W cm-2 LIFU treatment, as demonstrated by the CLSM results. While the same LIFU treatment shows no obvious damage to cells, as proved by the live/dead experiment, showing that 90% of cells remain alive.

Decorating Au onto Ni aerogel via a one-step spontaneous gelation preserved the highly porous structure of Ni aerogel, and contributed to more active sites and enhanced intrinsic activity for water oxidation with low overpotential of 377 mV for the current density of 100 mA cm -2 .

Molecular dynamics (MD) simulations have been performed to study the effects of pressure (P) on the crystallization of tantalum (Ta) under different pressures from [0, 100] GPa. The average potential energy of atoms in the system, the pair distribution function and largest standard cluster analysis (LSCA) have been employed to analyze the structure evolution. It was found that the solidified state at 100 K changes from the complex crystal (β-Ta) through the body-centered cubic (bcc) crystal (α-Ta) to the hexagonal close-packed (hcp) crystal with increasing pressure. At P ≤ 3 GPa, the favorable state is β-Ta, which is composed of Z12, Z14 and Z15 atoms, and crystallization starts at the same temperature of crystallization (Tc = 1897 K), while there is a stochastic relationship between the crystallinity and pressure. At P ∈ [3, 57.5] GPa, the melt is always crystallized into rather perfect α-Ta, and Tc is nearly linear to pressure. However, when P > 57.5 GPa, a quite perfect bcc crystal is first formed and then transforms to a hcp crystal via a solid-solid (bcc-hcp) phase transition. Moreover, if the new hcp atoms formed in the bcc stage are arranged in regular grains, the bcc-hcp transition would take a multiple-intermediate-state pathway else, a single-intermediate-state pathway is the possibilty. Additionaly, the parameter δs readily reflects the crystallinity of the β-Ta, and smaller the value of δs, higher is the crystallinity of the β-Ta. Finally, during the bcc-hcp transition under high pressure, the volume reduction is due to the rearrangement of atoms rather than the reduction in the atomic radius; a slight increase in the number of nearest neighboring pairs results in a significant increase of the system energy.

Wearable biochemical sensors are of great interest nowadays due to their powerful potential in personalized medicine and continuous monitoring of human health. Thus, a great deal of effort has been put into the development of such sensors to enable real-time and non-invasive quantification of various chemical constituents in the human body such as sweat, saliva, and tears. Owing to the advances in materials science and mechanical engineering, wearable biochemical sensors have been developed to probe various biomarkers and have been subsequently considered as wearable electronic devices for practical applications. In this review, we present a broad overview on the recent advances in electrochemical wearable sensors towards various organic components and ions closely linked to human health. With an emphasis on materials and manufacturing technologies of the sensing electrodes, the research status is summarized, and the challenges and opportunities in this growing field are prospected.

While the external quantum efficiency (EQE) of iridium(iii) (Ir(iii)) phosphor based near-infrared organic light-emitting diodes (NIR OLEDs) has been limited to 5.7% to date, there is no significant EQE improvement for these types of OLEDs due to the lack of efficient Ir(iii) emitters. Here, a convenient approach within three synthetic steps is developed to afford two novel and efficient deep-red to near-infrared (DR-NIR) emitting phosphors ( CNIr and TCNIr ), in which a cyano group is added into a commercial red emitter named Ir(piq)2(acac) to significantly stabilize the lowest unoccupied molecular orbitals of the newly designed Ir(iii) complexes. They emit strong DR-NIR phosphorescence emissions at a wavelength of around 700 nm, with relatively high absolute quantum efficiencies of around 45% for their doped films. DR-NIR OLEDs made using CNIr and TCNIr exhibit high-efficiencies, affording peak EQEs of 10.62% and 9.59% with emission peak wavelengths of 690 and 706 nm, respectively. All these devices represent the most efficient Ir(iii)-based DR-NIR OLEDs with a similar color gamut. The simplified synthesis procedure of the DR-NIR-emitting phosphors in conjunction with their excellent performance in OLEDs confirms our efficient strategy to achieve the DR-NIR-emitting Ir(iii) phosphors., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Three novel donor-acceptor polymers (PCz0, PCz2 and PCz4) based on 9-(9-heptadecanyl)-9 H -carbazole and isoindolo[2,1- a ]benzimidazol-11-one with fluorine substituents (0, 2 and 4) on the acceptor unit were prepared by Suzuki polymerization. The synthesized polymers were studied by theoretical calculation, and optical and electrochemical characterizations to further investigate the performance of memory storage and light-emission. The memory devices of the three polymers all exhibited obvious ternary flash behavior with total ON/OFF state current ratio around 10 4 and threshold voltages below 3.0 V, with no other blending or doping. Bright emissions of an electroluminescence device based on PCz0 was obtained at 556 nm, the maximum brightness was 2006 cd m -2 with EQE of 0.21%. The results suggested that polymers with the structure of carbazole-based donor as backbone and isoindolo[2,1- a ]benzimidazol-11-one segment as acceptor could be excellent materials for memory storage and light-emitting applications with further investigation and could be used for further design of other new polymer systems., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Molecular structure characteristics and morphological features of asphaltene can be significantly influenced by the addition of asphaltene inhibitors (AI). We have recently developed a novel concept of using nanoemulsions (NE) as carriers for controlled release of asphaltene inhibitors, which could prohibit the precipitation problem with reduced AI quantity. In this work, X-ray diffraction (XRD) was utilized to investigate the changes in the stacking behaviour of asphaltenes in the presence of three cases: (i) strong organic acids (dodecyl benzene sulfonic acid, DBSA), (ii) nanoemulsions (blank NEs), and (iii) nanoemulsion loaded DBSA (DBSA NEs). Based on the XRD and transmission electron microscopy (TEM) analyses, the stacking distance between aromatic rings of asphaltene was found to be increased by 22.2%, suggesting that the modification of the π system over the aromatic zone prevented the ultimate π-π interactions between asphaltene sheets. The evidence of multiple intermolecular interactions quantitatively obtained from Fourier-transform infrared spectroscopy (FTIR) supported our proposed mechanism for controlled release effect and long-term asphaltene stability, i.e. , the decrease of the aromaticity and the reduction in the aliphatic side chains of asphaltene. The refractory nature of asphaltenes was examined by thermogravimetric analysis (TGA), which showed that the asphaltene structure was improved considerably and the coke yield was decreased by 62% due to the decrease of the cluster size and the increase of the stacking distance., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Pharmaceutically important compounds were synthesized through the organocatalytic 1,3-dipolar cycloaddition reaction. In the presence of a cinchonine-derived squaramide catalyst, the cycloaddition of N-2,2,2-trifluoroethylisatin ketimines with α,β-unsaturated pyrazolones gave a spiro-pyrrolidine-linked oxindole and pyrazolone compound bearing four consecutive stereocenters and two vicinal spiroquaternary chiral centers, in excellent yields and stereoselectivities.

The first organocatalytic method for the asymmetric construction of CF3-containing spiro-thiazolone-pyrrolidine compounds has been developed. This is one of the very few methods to reach spiro-thiazolones, and afforded the products in excellent yields and stereoselectivities catalysed by only 1 mol% cinchona alkaloid-derived catalyst.

Obesity is a severe public health problem worldwide. Our study aims to assess whether a saponin-enriched extract from the leaves of Boussingaultia gracilis (SBG) could attenuate obesity and its related metabolic disorders in mice and to explore the potential mechanism of this effect. Three-week old male mice were fed with a HFD for 7 weeks followed by a 10-week period in which the mice were supplemented with distilled water or SBG (250 mg per kg bodyweight). We demonstrated that SBG supplementation for 10 weeks mitigated obesity and its complications in diet-induced obesity (DIO) mice, such as reducing the hepatic damage underlying steatosis, modulating lipid metabolism, enhancing adipocyte thermogenesis, restoring insulin sensitivity and glucose homeostasis, and alleviating inflammation status. Finally, we established an untargeted metabolomics approach based on UPLC-MS to profile the metabolic changes in liver tissue and thereby discovered novel potential biomarkers to clarify the mechanisms of action of SBG in treating a mouse model of DIO. Thirty-nine potential biomarkers and five metabolic pathways contributing to the beneficial effect of SBG were discovered and identified.

Two-dimensional boron nitride (2D-BN) materials doped with metallic atoms are suitable candidates for the oxygen reduction reaction (ORR) to replace Pt-based catalysts. In this study, a series of model 2D-BN materials doped with metallic atoms were designed to uncover the relationship between ORR activity and metallic dopants. A volcano curve correlation was derived between ORR overpotential and the adsorption free energy values of *OH. Only the doped structures, located at the top of the volcano curve, exhibit optimized activity. Through analyzing the dynamic results, the ORR was found to occur only via the 4e- pathway on Co doped 2D-BN materials with the activation energy of 0.30 eV, which is lower than that achieved with the state-of-the-art Pt-based catalysts (0.79 eV). Furthermore, based on the calculations of electronic structure properties, we find that the small highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap is more beneficial to the 4e- pathway and prove that the binding strength between metallic atoms-doped 2D-BN materials and oxygenated intermediates is regulated by the HOMO of the metallic dopant consisting non-bonding or delocalized orbitals. These results provide an effective method to facilitate the design of new BN-based materials with high electrocatalytic performances besides the ORR performance.

Nonvolatile ternary memory devices were fabricated from the composites polymer blends containing zinc oxide (ZnO) nanoparticles. When applying a negative bias on the top electrode, the fabricated devices with a simple sandwich structure of indium tin oxide (ITO)/composite polymer/aluminum (Al) exhibited three distinct resistance states, which could be labeled as "OFF", "ON1" and "ON2" for ternary data storage application. The ITO/polystyrene (PS) + ZnO/Al devices can endure 3 × 10 4 read-cycles and exhibit a retention time of 10 4 s. The resistance-temperature dependence at different resistance states was investigated to confirm the temperature-dependent properties. The resistance of the "OFF" and "ON1" state reveals negative temperature dependence, manifesting a typical semiconductor characteristic. The resistance of the "ON2" state exhibits positive temperature dependence, showing metallic properties.

Gels and aerogels derived from colloidal nanoparticles not only own the advantages of the traditional aerogels like ultra-low density, large surface area and high porosity, but also retain some of the unique properties of the nanoparticles. These characteristics endow such new types of materials with the possibility of promising applications. In this review, we focus on the function-led design of aerogels from the 3D assembly of 0D spherical particles, 1D nanowires, and 2D nanosheets, and especially their applications in catalysis, sensing, optoelectronics, pollutant adsorbents/filtration, and beyond.

For enhanced oil recovery (EOR) applications, the oil/water flow characteristics during the flooding process was numerically investigated with the volume-of-fluid method at the pore scale. A two-dimensional pore throat-body connecting structure was established, and four scenarios were simulated in this paper. For oil-saturated pores, the wettability effect on the flooding process was studied; for oil-unsaturated pores, three effects were modelled to investigate the oil/water phase flow behaviors, namely the wettability effect, the interfacial tension (IFT) effect, and the combined wettability/IFT effect. The results show that oil saturated pores with the water-wet state can lead to 25-40% more oil recovery than with the oil-wet state, and the remaining oil mainly stays in the near wall region of the pore bodies for oil-wet saturated pores. For oil-unsaturated pores, the wettability effects on the flooding process can help oil to detach from the pore walls. By decreasing the oil/water interfacial tension and altering the wettability from oil-wet to water-wet state, the remaining oil recovery rate can be enhanced successfully. The wettability-IFT combined effect shows better EOR potential compared with decreasing the interfacial tension alone under the oil-wet condition. The simulation results in this work are consistent with previous experimental and molecular dynamics simulation conclusions. The combination effect of the IFT reducation and wettability alteration can become an important recovery mechanism in future studies for nanoparticles, surfactant, and nanoparticle-surfactant hybrid flooding process.

This study presents the first evidence for the accelerated degradation of phenol by Fenton's reagent in a mini-fluidic VUV/UV photoreaction system (MVPS). A low-pressure mercury lamp used in the MVPS led to a complete degradation of phenol within 4-6 min. The HO˙ and HO 2 ˙ originating from both Fenton's reagent and VUV photolysis of water were identified with suitable radical scavengers. The effects of initial concentrations of phenol, H 2 O 2 and Fe 3+ as well as solution pH on phenol degradation kinetics were examined. Increasing the initial phenol concentration slowed down the phenol degradation, whereas increasing the initial H 2 O 2 or Fe 3+ concentration accelerated the phenol degradation. The optimal solution pH was 3.7. At both 254 and 185 nm, increasing phenol concentration enhanced its absorption for the incident photons. The reaction mechanism for the degradation of phenol was suggested consistent with the results obtained. This study indicates that the VUV/UV photo-Fenton process has potential applications in the treatment of industrial wastewater containing phenol and related aromatic pollutants.

Memory devices based on composites of polystyrene (PS) and [6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM) were investigated with bistable resistive switching behavior. Current-voltage (I-V) curves for indium-tin-oxide (ITO)/PS + PCBM/Al devices with 33 wt% PCBM showed non-volatile, rewritable, flash memory properties with a maximum ON/OFF current ratio of 1 × 10 4 , which was 100 times larger than the ON/OFF ratio of the device with 5 wt% PCBM. For ITO/PS + PCBM/Al devices with 33 wt% PCBM, the write-read-erase-read test cycles demonstrated the bistable devices with ON and OFF states at the same voltage. The programmable ON and OFF states endured up to 10 4 read pulses and possessed a retention time of over 10 5 s, indicative of the memory stability of the device. In the OFF state, the I-V curve at lower voltages up to 0.45 V was attributed to the thermionic emission mechanism, and the I-V characteristics in the applied voltage above 0.5 V dominantly followed the space-charge-limited-current behaviors. In the ON state, the curve in the applied voltage range was related to an Ohmic mechanism.

Nonvolatile memory devices based on active layers of poly(vinyl alcohol) (PVA) + graphene oxide (GO) hybrid composites have been fabricated. The performance of the ITO/PVA + GO/Al device was compared with that of the ITO/PVA/Al device. The ITO/PVA + GO/Al device showed excellent performance compared to the ITO/PVA/Al device (an ON/OFF resistance ratio of 1.2 × 10(2) at 1 V, V(SET )∼ -1.45 V and V(RESET) ∼ 3.6 V), with a higher ON/OFF resistance ratio of 3 × 10(4) at 1 V and lower operating voltages of V(SET) ∼ -0.75 V and V(RESET) ∼ 3.0 V. Furthermore, endurance performance and write-read-erase-reread (WRER) cycle tests manifest that the presence of GO in ITO/PVA + GO/Al devices makes them have better stability and repeatability. The results show that the performance of hybrid devices can be effectively enhanced by the introduction of GO into the PVA matrix.

Nonvolatile memory devices, based on electrical conductance tuning in thin films of poly(4-vinyl phenol) (PVP) and 2-(4-tert-butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole (PBD) composites, are fabricated. The current-voltage characteristics of the fabricated devices show different electrical conductance behaviors, such as the write-once read-many-times (WORM) memory effect, the rewritable flash memory effect and insulator behavior, which depend on the content of PBD in the PVP + PBD composites. The OFF and ON states of the WORM and rewritable flash memory devices are stable under a constant voltage stress or a continuous pulse voltage stress at a read voltage. The memory mechanism is deduced from the modeling of the nature of currents in both states in the devices.

The electrical conductance switching behavior and nonvolatile memory effects in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), Pedot: PSS and single-wall carbon nanotubes (SWCNTs) composite thin films have been investigated. The effect of doping level on electrical conductance switching behavior of an indium tin oxide/, Pedot: PSS + SWCNTs/aluminum (ITO/PEDOT:PSS + SWCNTs/Al) sandwich structure has been reported. The ITO/(PEDOT:PSS + SWCNTs)/Al devices show current bistability. Moreover, the ON/OFF state current ratio is in an extent of 10(2)-10(4). The OFF state current increased with the decreasing SWCNTs content in the composite film, and the ON/OFF state current ratio of the device increases with the increase in SWCNTs content of the composite film. Thus, by varying the doping level of SWCNTs in, Pedot: PSS composite thin films, the electrical conductance switching behavior of ITO/PEDOT:PSS + SWCNTs/Al can be modulated in a controlled manner.

A class of novel nickel cobalt oxide hollow nanosponges were synthesized through a sodium borohydride reduction strategy. Due to their porous and hollow nanostructures, and synergetic effects between their components, the optimized nickel cobalt oxide nanosponges exhibited excellent catalytic activity towards oxygen evolution reaction.

Chemiluminescent acridinium dimethylphenyl esters are highly sensitive labels that are used in automated assays for clinical diagnosis. Light emission from these labels and their conjugates is triggered by treatment with alkaline peroxide. Conjugation of acridinium ester labels is normally done at the phenol. During the chemiluminescent reaction of these acridinium esters, the phenolic ester is cleaved and the light emitting acridone moiety is liberated from its conjugate partner. In the current study, we report the synthesis of three new acridinium esters with conjugation sites at the acridinium nitrogen and compare their properties with that of a conventional acridinium ester with a conjugation site at the phenol. Our study is the first that provides a direct comparison of the emissive properties of acridinium dimethylphenyl esters (free labels and protein conjugates) with different conjugation sites, one where the light emitting acridone remains attached to its conjugate partner versus conventional labeling which results in cleavage of the acridone from the conjugate. Our results indicate that the conjugation at the acridinium nitrogen, which also alters how the acridinium ring and phenol are oriented with respect to the protein surface, has a minimal impact on emission kinetics and emission spectra. However, this mode of conjugation to three different proteins led to a significant increase in light yield which should be useful for improving the assay sensitivity.

Many chemical and biomedical systems require delivery and controlled release of small molecules, which cannot be achieved by conventional polyelectrolyte-based layer-by-layer capsules. This work proposes an innovative hybrid microcapsule by incorporating in situ formed silica nanoparticles within or on the shell. The influence of various experimental conditions on the stability, mechanical strength and morphology of capsules was investigated and characterised by SEM, TEM, XRD, EDX and FTIR. The multifunctional capabilities of the formed capsules were examined by encapsulating a small molecule rhodamine B (Rh-B) which could be further released by an ultrasonic trigger. The results show that in situ formed SiO 2 nanoparticles through hydrolysis greatly reduced the permeability of the shell yet showed increased mechanical strength and ultrasound response. SiO 2 nanoparticles were shown to be distributed on the surface or inside the polyelectrolyte shell, acting as supports for free-standing capsules in both liquid and dry environments. Rapid Rh-B molecule release and the fragmentation of the capsule shells were observed under 50 W ultrasound irradiation for a few seconds. Such innovative capsules with the capability of small molecule encapsulation and high ultrasound sensitivity could be promising for many applications where pulse release of small molecules is required.