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A molecular design platform based on tyramine, a widely existing bio-amine with flexible structural modifiability, has been employed to synthesis a novel phthalonitrile matrix resin and curing agent in this work. The structures of the products were verified via nuclear magnetic resonance (1H-NMR, 13C-NMR), Fourier-transform infrared spectroscopy (FTIR), and elemental analysis (EA) studies. The rheology and DSC data showed that the tyramine-based resin presented a lower melting point and a wider processing temperature window compared with its petroleum-based counterpart. The cured resin exhibited excellent thermal and thermo-oxidative stability, according to thermal gravimetric analysis (TGA) data, and a high glass-transition temperature (480 °C), based on the dynamic mechanical analysis (DMA) curve. The curing chemistry was studied via ex situ FTIR, in situ FTIR, solid-state nuclear magnetic resonance, and molecular simulation studies. The results showed that the methine moiety of the curing agent may initiate –CN polymerization at lower pre-curing temperatures, and the methylene group of tyramine may act as an active site for secondary crosslinking reactions at higher post-curing temperatures.

A series of electric field profile simulations in gallium nitride (GaN) p-i-n vertical diodes with negative bevel termination is carried out to optimize the bevel design. The bevel angles are varied from 90° to 0.1° with reasonably small increments to study the impact of the bevel angle on the electric field profile. The doping densities are also varied to study a more generalized trend; a new parameter defined as transition angle $\theta _{{\text {t}}}$ is proposed to characterize the effectivity of a beveled edge termination. Considering the potential dry etch damage on the bevel side-wall during device fabrication, the fixed surface charge from the dangling bonds and commonly used dielectric passivation are also added separately to investigate their influence. This article presents a comprehensive simulation study of GaN p-i-n diode with negative beveled edge termination, making it a useful guide for designing a simple and effective beveled edge termination, which eventually helps to enable the routine avalanche in GaN p-i-n diodes.

Chemical messengers have been recognized as signaling molecules involved in regulating various physiological and metabolic activities. Nevertheless, they usually show limited regulatory efficiency due to the complexity of biological processes. Especially for tumor cells, antideath pathways and tumor metastasis are readily activated to resist chemical messenger regulation, further impairing antitumor outcomes. Therefore, it is imperative to develop strategies for tumor eradication with chemical messengers. Herein, a nanomessenger was prepared with signaling transduction cascades to amplify the regulatory activity of chemical messengers and mediate antitumor immunotherapy. Casup2+/supand Hsub2/subS as two chemical messengers were released from nanomessengers to synergistically elevate intracellular Casup2+/supstress and mediate subsequent cell death. Meanwhile, zinc protoporphyrin (ZnPP) as a messenger amplifier suppressed the antideath effect of tumor cells. As a result, tumor cells underwent Casup2+/sup-dependent cell deathivia/isignaling transduction cascades to release tumor-associated antigens, which further served as aniin situ/itumor vaccine to activate antitumor immunity.iIn vivo/istudies revealed that both primary tumors and distant metastases were markedly eradicated. Furthermore, immunological memory was fabricated to arrest tumor metastasis and recurrence. This work introduces cascade engineering into chemical messengers and thus offers a strategy for amplifying chemical messenger-mediated cellular regulation, which would promote the future development of chemical messenger-mediated immunotherapy.̀.

The numerous drawbacks hindering the practical take-off of the lithium–sulfur technology requires significant breakthrough in designing novel sulfur host. Herein, bipyramidal sulfur/graphene oxide composite cathode with sulfur content of 92% is obtained via a room-temperature bottom-up approach with the aid of polyvinylpyrrolidone. Material characterization reveals the uniform coating of each individual sulfur particle by a thin wall of graphene oxide and residual polyvinylpyrrolidone molecules. The robustness and close proximity of the protective graphene oxide shell not only facilitates electron and ion transportation but also restrains the diffusion of polysulfides through interfacial chemical interaction. As a result, the cathode manifests a high initial reversible capacity of 1301 mAh g−1 at 0.2 C, outstanding capacity retention of 86.4% at 1 C after 115 cycles and long cycle life of 250 cycles with 360.6 mAh g−1 remaining capacity at 2 C. The present work provides an affordable and sustainable approach of confining sulfur at high content which is essential for high-energy density lithium–sulfur battery.

A novel partial bio-based molecular design platform for high performance polymer (HPP) namely diamine-adenine-monomer platform (DAAMP) was suggested and discussed in this paper. Aimed at introducing the adenine moiety into backbone of HPP and endowing great wide molecular tailorability, DAAMP was synthesized via a nucleophilic displacement between 6-chloropurine and various diamines. Phthalonitrile (PN) resin is a typical class of HPP. To verify the feasibility of DAAMP for HPP design, two new phthalonitrile monomers based on two different diamine namely DAAMP-PN were synthesized. The chemical structures of synthesized monomers were confirmed by Fourier Transform Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). The two new DAAMP-PNs based on different diamines showed an obvious difference in thermal polymerization behavior. Multiple hydrogen bonding was exhibited in DAAMP-PN system. And the prepared DAAMP-PN polymer showed high glass transition temperature, excellent thermal and thermo-oxidative stabilities. The results demonstrated that DAAMP is a promising building-block for HPP design with flexible molecular tailorability.

Here, the supramolecular interaction between nucleobase adenine and graphene was strengthened by a novel chemical molecular designing strategy. Based on this approach, the adenine-bridged aromatic phthalonitrile (AAPN) was prepared as stabilizer toward liquid-phase exfoliation for non-covalent functionalized graphene (AAPN-G). A series of experiments were carried out to verify the strong supramolecular interaction between AAPN and graphene. The feasibility of multifunctional application of the AAPN was briefly demonstrated. This work constitutes a feasible strategy in the preparation and functionalization of graphene that could be extended to some other (bio)molecules toward realization of designing multifunctional materials.

The effects of the addition of primary alcohol fuels (methanol, ethanol, and n-butanol) on the combustion characteristics and performance of natural gas engines are examined by experimentation with a dual-fuel test engine, followed by a comparative analysis of the test results. The test engine was operated under a light load, at a fixed speed of 1600 rpm, and with a brake mean effective pressure of 0.387 MPa. The air-fuel ratio was held constant at the stoichiometric equivalent ratio. The engine performance was analyzed for different natural gas/alcohol fuel mixtures by using four alcohol fuel energy substitute ratios (AESRs): 0% (pure natural gas), 19%, 44%, and 60%. The experimental results indicate that faster burning rates can be obtained by mixing any of the three alcohol fuels with natural gas, compared with pure natural gas. Further, by increasing the AESR, faster flame development and flame propagation times can be obtained, and the crank angle when 50% of the mass is burned approaches the top dead center position. These outcomes lead to an advance in combustion phasing. The addition of primary alcohol fuels in the dual-fuel mode can also reduce total hydrocarbon and nitrogen oxide emissions. Moreover, the brake thermal efficiency of natural gas can be improved significantly by adding methanol, whereas negligible improvements in this aspect are obtained by adding ethanol and n-butanol. The comparative analysis indicates that methanol addition has advantages over ethanol and n-butanol additions in increasing the brake thermal efficiency and reducing the regulated emissions of natural gas engines.

Exploring scalable and cost-effective material preparation route is critical for achieving the commercialization of lithium–sulfur batteries. Herein, nitrogen and sulfur codoped carbon dots/reduced graphene oxide (N,S-CDs/rGO) composites are facilely fabricated via hydrothermal and annealing treatment of a mixture of graphene oxide and egg-white without additional reactants. The egg-white, not only act as heteroatoms source, but also produce carbon dots. The as-prepared material possesses a porous architecture with N,S-codoping into both graphene and carbon dots. Benefiting from combined advantages of each constituent, such as superior electrical conductivity, abundant edges and doping sites, N,S-CDs/rGO cathodes (with 65 wt% and 76 wt% sulfur content) exhibits enhanced performances characterize by a higher rate capability and high sulfur utilization. For instance, N,S-CDs/rGO@S65 cathode exhibits a capacity of 1550 mAh g−1 at 0.5 C and still kept high capacities of 1038, 861.1 and 783.6 mAh g−1 at 1, 3, and 5 C respectively. Even at an ultra high rate of 7 C, a capacity of 740.8 mAh g−1 is sustained. Moreover the cathode retains 427.9 mAh g−1 reversible capacity after 600 cycles at 5 C. This work provides a new route toward the simple design of cathode for advanced Li–S cells.

In this paper, an adenine-derived fluorescent chromophore (HCC-APA) was synthesized to detect its interaction with iron ions. The results showed that a large stokes shift (υ = 10981.5 cm−1) fluorescence of the HCC-APA was appeared. The fluorescence quantum yields of HCC-APA in DMF and THF were 3.49% and 17.54%, respectively, demonstrating its higher fluorescence performance than unmodified adenine. Besides, the fluorescence quenching of HCC-APA with iron ions was further detected. Fluorescence titration experiments confirmed that the detection limit of HCC-APA for Fe3+ was 3.69 μM. The interaction between iron ions and HCC-APA was investigated by continuous variable method, indicating that the binding ratio is 1:1. And the interaction site was deeply explored by 1H NMR and molecular simulation.

Lithium–sulfur (Li–S) batteries have attracted an increasing attention for advanced energy storage devices, because of their high energy density, low cost and lower environmental impacts. However, their commercial applications are still hampered with the low conductivity and sulfur utilization, the low sulfur loading and the serious capacity fading at a high current rate. Herein, we prepared flower-like molybdenum disulfide and carbon nanotubes (MoS2/CNTs) composites with mesoporous structures for high sulfur utilization cathodes. The flower-like MoS2 can immobilize sulfur and obstruct the solubility of polysulfide within the structures. The MoS2/CNTs-S cathode with 2.6 mg cm−2 sulfur loading and capacity per area of 3.83 mA h cm−2 delivers an initial specific discharge capacity of 1473 mA h g−1 with 88.0% sulfur utilization and maintains a reversible capacity of 855.5 mA h g−1 with coulombic efficiency up to 96.6% after 50 cycles at the current rate of 0.2 C (335.0 mA g−1). Impressively, the MoS2/CNTs-S cathode at 5 C shows the high specific capacity of 1254 mA h g−1 with 76.0% sulfur utilization and maintains 384.0 mA h g−1 with an average coulombic efficiency of 91% after 200 cycles. The MoS2/CNTs-S cathode could be a good candidate for high-performance Li–S battery.

This paper aimed to study the effects of spark timing and methanol addition on the combustion characteristics and emissions of a natural gas/methanol dual-fuel engine. The engine speed is maintained at 1600 rpm and the brake mean effective pressure (BMEP) is maintained at 0.387 MPa with an excess air/fuel ratio of 1.3. The methanol energy substitution ratio (MSR) is set to 0%, 7.5%, and 14.5%. The spark timings are varied from 18 °CA to 38 °CA before the top dead centre, in intervals of 4 °CA. The results demonstrate that for a specific spark timing, the methanol addition increases the peak cylinder pressure, the maximum of the heat release rate, and the peak cylinder mean temperature. Concurrently, it decreases the flame development period (CA0-10) and the flame propagation period (CA10-90) with an increase in the MSR. An improvement in the brake thermal efficiency (BTE), a reduction in the total hydrocarbon (THC) emission, and an increase in the nitrogen oxide (NOX) emission are achieved using methanol enrichment. In addition, the effect of these trends is more pronounced with an increase in MSR. In contrast, for a specific MSR, a spark timing advance increases the peak cylinder pressure and temperature, while decreasing the exhaust temperature under an identical BMEP. Moreover, the spark timing at the maximum BTE retards as MSR increases.

Accurately modeling the kinetics of the pyrolysis reaction of phthalonitrile resin was helpful to investigate the pyrolysis mechanisms. To study the pyrolysis kinetics, phthalonitrile resin was measured by thermogravimetric analysis (TGA) at different heating rates in flowing nitrogen. The results indicated that there were two consecutive and overlapping stages in the pyrolysis process. The overlapped peaks were separated by multi-peak fitting method. Two models, namely, Kissinger, Kissinger-Akahira-Sunose (KAS), were employed to calculate activation energy at various stages of pyrolysis process. Kinetic models were determined using the differential method and Coats-Redfern method. Based on the attained kinetic models and activation energy values, the pre-exponential factor values were determined by KAS method. According to the calculated apparent activation energies, the most probable kinetic mechanism functions and pre-exponential factors, the simulated data agreed well with the experimental data.

A hydrogel drug cargo based on 2D tungsten nitride nanosheets was fabricated. It exhibits stable NIR-II responsive photothermal properties and drug release behaviour. Moreover, this hydrogel shows excellent tumour ablation efficiency in vivo via NIR-II triggered multiple chemo/photothermal therapy.

This paper describes the development of vertical GaN PN diodes for high-voltage applications. A centerpiece of this work is the creation of a foundry effort that incorporates epitaxial growth, wafer metrology, device design, processing, and characterization, and reliability evaluation and failure analysis. A parallel effort aims to develop very high voltage (up to 20 kV) GaN PN diodes for use as devices to protect the electric grid against electromagnetic pulses.

Aim Imbalanced mitochondrial dynamics including suppressed mitochondrial fusion has been observed in diabetic hearts. However, it is still unknown whether mitochondrial fusion promoter is an effective protection to diabetic hearts. This study was designed to explore the efficacy of mitochondrial fusion promoter on diabetic cardiomyopathy (DCM). Methods Male Sprague-Dawley rats were injected with streptozotocin (STZ, 65 mg/kg/d) intraperitoneally to induce diabetes. Seven weeks after vehicle or STZ injection, control or diabetic rats were treated with the vehicle or a mitochondrial fusion promoter-M1 (2 mg/kg/d) intraperitoneally for 6 weeks. Moreover, M1 was administrated to the primary cardiomyocytes cultured in normal glucose medium (NG, 5.5 mmol/L) or high glucose (HG, 33 mnol/L). Results Administration of M1 significantly promoted mitochondrial fusion and attenuated the reduction in optic atrophy 1 (Opa1) expression in diabetic hearts. Importantly, M1 treatment attenuated oxidative stress, improved mitochondrial function and alleviated DCM in diabetic rats. In HG-treated cardiomyocytes, M1 treatment consistently increased the expression of Opa1, promoted mitochondrial fusion, enhanced mitochondrial respiratory capacity and reduced mitochondria-derived superoxide production, all of which were blunted by Opa1 siRNA knockdown. In addition, selective upregulation of Opa1 alone can also promote mitochondrial fusion, improve mitochondrial function and inhibit mitochondria-derived superoxide production in HG-cultured cardiomyocytes. Conclusion Our findings show for the first time that mitochondrial fusion promoter M1 effectively balances mitochondrial dynamics and protects against diabetic cardiomyopathy (DCM) via an Opa1-dependent way, suggesting that promoting mitochondrial fusion might be a potential therapeutic strategy for DCM.

A 400-nm thick composite field plate oxide, with a combination of atomic layer deposited and plasma enhanced chemical vapor deposited SiO2 layers, is used to enhance the breakdown voltage of spin-on-glass source/drain doped lateral Ga2O3 MOSFET. Three terminal breakdown voltage measured in Fluorinert ambient reaches 1850 V for a ${L}_{\textsf {gd}}= \textsf {20}\,\,\mu \text{m}$ device. This is the first report of lateral Ga2O3 MOSFET with more than 1.8 kV breakdown voltage. For a device with ${L}_{\textsf {gd}}= \textsf {1.8}\,\,\mu \text{m}$ , the average electric field strength is calculated to be 2.2 ± 0.2 MV/cm while the field simulation of the device shows a peak field of 3.4 MV/cm.

Manganese dioxide (MnO2)-based nanomaterials can be used as sulfur host, improving the cycle stability by inhibiting the shuttle effects of polysulfide through chemisorption with the polar host. In this work, we design a novel soft template synthesis of acetylene black and MnO2 nanosheets (AB/MnO2) composites by simple and cost-effective methodology. The AB/MnO2 was used as a highly efficient sulfur host for advanced lithium–sulfur batteries. The cheap and highly conductive AB facilitates fast electron transport. The polar host, MnO2 nanosheets, provides chemical interactions and efficiently impedes the dissolution of polysulfide. Accordingly, the cathodes AB/MnO2–S (4:1) and AB/MnO2–S (1:1) with 67 and 70 wt% sulfur content deliver the initial discharge specific capacity of 1326 and 1113 mA h g−1 at the current density of 837.5 mA g−1 (0.5 C), respectively. Particularly, the AB/MnO2–S (1:1) cathode shows the most stable coulombic efficiency and cyclability compared with AB/S cathode after 200 cycles. In addition, the AB/MnO2–S (4:1) cathode exhibits a capacity of 1071 mA h g−1 at the current density of 1675 mA g–1 (1 C). Along with this green and cost-effective protocol of synthesis, we expect that the AB/MnO2 composites have potential application in advanced Li–S batteries.

A series of PIs (APIs) containing naturally occurring adenine moiety in polymer backbone has been prepared from adenine-containing diamine (p-APA) and commercial dianhydrides by a two-step polymerization process. FTIR study confirmed the structures of APIs. The hydrogen-bonding interactions of APIs were studied by FTIR, in-situ FTIR and theoretical methods. The crystalline behavior of APIs were studied by XRD, and the results showed that the APIs have relatively high degree of crystalline. Birefringence and polarized ATR FTIR studies showed that the groups and chains in API films could be simultaneously self-arranged in the in-plane direction without any further stretching. Molecular simulation methods were introduced to study the relationship between self-arranged in-plane orientation and hydrogen-bonding interactions. Thermogravimetric analysis (TGA) showed that the 5% weight loss of APIs (T5) are in the range of 511–569 °C in nitrogen, and the char yields (CR) of APIs are in the range of 55–67% under nitrogen condition. Dynamic mechanical analysis showed that the glass-transition temperature (Tg) are in the range of 315–400 °C. The mechanical properties were studied by universal strength tester, and the results showed that the tensile modulus of API films were in the range of 4.43–9.21 GPa, and the tensile strength of API films were in the range of 124.9–162.9 MPa. Thermal mechanical analysis showed that the in-plane CTE of APIs are in the range of −5.85–37.82 ppm/°C.

A benzothiazole-based turn-on fluorescent probe with a large Stokes shift (190nm) has been developed for hypochlorous acid detection. The probe displays prompt fluorescence response for HClO with excellent selectivity over other reactive oxygen species as well as a low detection limit of 0.08μM. The sensing mechanism involves the HClO-induced specific oxidation of oxime moiety of the probe to nitrile oxide, which was confirmed by HPLC-MS technique. Furthermore, imaging studies demonstrated that the probe is cell permeable and can be applied to detect HClO in living cells.

Non-stretched adenine-containing polyimide films based on pyromellitic dianhydride (PMDA) and adenine-containing diamine (p-APA) were prepared and annealed at various temperatures. IR studies indicated the existence of transformation of hydrogen bonding types from N-H⋯N (in purine) to N-H⋯O (in carbonyl). The PMDA API films showed negative in-plane coefficient of thermal expansion (CTE) even annealed much higher than Tg. Morphology studies showed that the groups in PMDA API were inclined to self –arranged along the in-plane direction when annealed higher than Tg. The free volume fraction (FFV) of PMDA API films decreased with increasing annealing temperature. An orientation & hinge model was proposed to discuss the negative in-plane CTE behavior.

A turn-on fluorescent probe 1 has been developed for Cu2+ by the incorporation of picolinate onto a tricyanofuran-based fluorophore. The probe was weakly fluorescent due to the masked phenolic group and the resulted inhibition of the push-pull character of the fluorophore. The chemoselective reaction of probe 1 with Cu2+ leads to a dramatic fluorescence enhancement at 610 nm via the Cu2+-mediated hydrolysis of picolinate moiety and the subsequent release of the highly emissive fluorophore. This probe features high selectivity for Cu2+ over other cations, as well as high sensitivity with a low detection limit of 54 nM. Moreover, cell cytotoxicity and imaging tests indicate that probe 1 is biocompatible and can be utilized for imaging Cu2+ in live cells.

To broaden the application of polyimide materials, adenine-based polyimide/nano-silica hybrid films were prepared via sol-gel method without using coupling agents. Adenine-based diamine, 9,10-bis(4-aminopheny)adenine (p-APA), was introduced to polymerize with 3,3′,4,4′-tetracarboxydiphthalic ether dianhydride (ODPA) to synthesize polyimide (API) matrix. The compatibility between the polymer matrix and silica was improved by hydrogen bonding between NH group in p-APA and Si OH group in silica. Systematic studies showed that API hybrid films possess high transparency and outstanding thermal properties even though the doping content was up to 20 wt% (glass transition temperature (Tg): 328 °C, maximum decomposition occurring temperature (Tmax): 603 °C (N2), coefficient of thermal expansion (CTE): 16.60 ppm/oC).

Reducing environmental harm and improving fertilizer use efficiency is critical in Chinese agriculture. Azolla has particular value for paddy rice crop due to its biological nitrogen (N) fixation ability; however, the Chinese rice fields are highly fertilized, which will depress the N fixation of Azolla. Urea deep placement (UDP) reduces floodwater NH4+ and ammonia volatilization losses. To date, few studies have explored the effects of UDP combined with Azolla on the N uptake pattern, N recovery and N loss from 15N-labeled urea. Therefore, a 3-year field experiment was conducted with five treatments (control without urea (CK), urea broadcasting without Azolla (B) or with Azolla (BA), and UDP without Azolla (P) or with Azolla (PA)) in an intensive rice cropping system in the Taihu Region of China. The total 15N recovery (soil-plant system), crop 15N uptake (straw and grain) and 15N loss were assessed, and the ammonia (NH3) loss, rice yield, gross return and net economic benefit were measured. The results showed that the UDP treatments had delayed but long-lasting fertilization effects. The PA treatment resulted in the lowest 15N loss and highest total 15N recovery at harvest due to the prolonged N availability and negligible NH3 loss. The PA, P and BA treatments decreased 15N loss by 47%, 33% and 18% and increased total 15N recovery by 58%, 40% and 22%, respectively, compared to urea broadcasting alone. Almost all labeled Azolla-N was released within two months of which approximately 40% could be absorbed by the crop. Little labeled fertilizer N was absorbed by Azolla during the rice season. In addition, the PA, P and BA treatments increased rice yield and gross return by 13%, 10% and 9%, respectively, and they produced similar net economic benefit compared to urea broadcasting alone. In conclusion, UDP combined with Azolla is a potential strategy to further reduce fertilizer N loss and improve total fertilizer N recovery while maximizing rice yield if it can be widely adopted by Chinese rice farmers. However, widespread adoption will require improved technologies with lower labour requirement for mechanized deep placement of urea and for the propagation of Azolla.

It is urgently necessary to reduce environmental harm while simultaneously ensuring food security from agriculture in China. Fertilizer deep placement, especially urea deep placement (UDP), has been widely recognized as an efficient way to increase rice yield with less N use in flooded rice fields; however, few studies have explored UDP as a way to abate N loss, particularly ammonia (NH3) volatilization, in intensive rice cropping systems. Therefore, a field experiment was performed in the Taihu Region with five treatments (two surface split broadcasting treatments: a current traditional practice with 300 kg N ha−1 (CT) and a reduced N practice with 225 kg N ha−1 (RN), two one-time UDP treatments: a current traditional practice under UDP (CTDP) and a reduced N practice under UDP (RNDP), and a CK treatment with no urea). The NH3 volatilization, grain yield and N use efficiency in terms of the N recovery efficiency (NRE) were investigated during the 2014–2016 rice growing seasons. Additionally, N diffusion and 15N-labeled urea experiments were conducted to explore the N release pattern and the fate of 15N under UDP. The results demonstrated that little NH4+-N could diffuse into surface water under UDP, thus, negligible floodwater NH4+-N was detected. The seasonally cumulative NH3 volatilization of the UDP accounted for only 1% of the total applied N, which decreased by 91% compared to surface broadcasting treatments. As a result, the NH3 intensity (NH3-N loss per crop yield) was reduced by 92% over surface broadcasting. Moreover, the deep placement of urea could supply a higher NH4+-N concentration in the soil during the early growth stage and prolong the duration of N availability for 2 months; as a result, UDP remarkably increased the N uptake by 28% compared with surface broadcasting treatments in the 3 years. The UDP treatments significantly increased the yield and NRE by 10% and 55% under favorable weather conditions (2015 and 2016 rice seasons), respectively. The RNDP treatment obtained the lowest N surplus (36 kg N ha−1), and the plant 15N uptake was 62% higher and the 15N loss was 38% lower with RNDP than surface broadcasting. Therefore, the deep placement of urea can be considered a slow release fertilizer, which better matches the N demand of rice plants and effectively minimizes N losses, especially NH3 volatilization. The RNDP treatment, with a 25% reduction in the N dose, can represent an effective and promising strategy to achieve environmental integrity and food security in intensive rice cropping systems.

A series of new polyamides (inherent viscosities between 0.61 and 1.84 dL g−1) were prepared directly by low-temperature polycondensation of a new purine-moiety-containing diamines, 7,10-bis(4-amin...

Hollow structured mesoporous materials have attracted great interest in recent years. We present a new glucose biosensor based on dual function hollow structured mesoporous Prussian Blue (PB) mesocrystals (HMPB). HMPB serve as both a scaffold carrier matrix to immobilize the enzyme glucose oxidase (GOx-HMPB) on the electrode and as a redox mediator to H2O2, the by-product of GOx catalyzed glucose reaction. The Barrett–Joyner–Halenda (BJH) calculation based on nitrogen adsorption isotherm measurement indicates a ∼20 nm mesoporous outer shell and a ∼60 nm hollow cavity of HMPB that provide a large area (258 m2 g−1) for GOx loading. The larger surface area of HMPB compared to solid PB makes it much easier to reduce the HMPB at lower applied potential (0.130 V). The HMPB display enhanced sensitivity towards glucose detection due to increased GOx loading and increased catalytic sites of HMPB with the linear detection range from 0.05 to 7.3 mM, a limit of detection of 0.04 mM (S/N = 3) and a fast response time (within 6 s). The detected glucose level in human serum samples is in good agreement with the data from hospital clinical measurements. The data demonstrate that the HMPB mesocrystals acted effectively as both a redox mediator to H2O2 and a good enzyme carrier, suggesting that the strategy can be applied to other electroactive hollow mesoporous materials to prepare simplified biosensors for a wide range of clinical applications.

Phthalonitrile and alicyclic imide moiety blends were obtained by mechanical mixing, and the curing behaviors and kinetics parameters of the phthalonitrile/alicyclic imide moiety systems were investigated by non-isothermal differential scanning calorimetry (DSC). The results showed that an apparent autocatalytic model dα/dt = k(T)αm(1 − α)n can be determined to describe the systems, and the apparent activation energy of 3BOCN/CC-55, 3BOCN/CC-73 and 3BOCN/HCC-55 are 105.9, 120.6 and 83.4 kJ/mol with not much different reaction orders 1.67, 1.49 and 1.56, respectively. The conversions which are approximately 0.36, 0.41 and 0.40 corresponding to the maximum reaction rate values of 3BOCN/CC-55, 3BOCN/CC-73 and 3BOCN/HCC-55 are experimentally determined, respectively, which are in good agreement with the fitting values.

Further enriching the source of bio-based raw materials for thermosets is of significant importance in the current development context. In this paper, we synthesized a novel bio-based phthalonitrile monomer derived from L-tyrosine to verify the feasibility of a bio-based L-tyrosine molecular design platform for thermosets, and to prove that the L-tyrosine building-block can confer high performance. The biomass content of L-tyrosine-based phthalonitrile monomer reaches 56%, higher than other bio-based phthalonitrile resins. The structure was confirmed by 1H NMR, 13C NMR, Fourier-Transform Infrared Spectroscopy (FTIR) and elemental analyses. The curing behavior was investigated by FTIR spectra, differential scanning calorimetry (DSC) and in situ FTIR spectra. The processability was studied by rheological analysis. And a study of the curing kinetics of the TPN monomer was carried out by non-isothermal DSC. Finally, the physical properties of the cured polymer were evaluated by dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). The results indicate that the phthalonitrile resin exhibited a high glass transition temperature (Tg) and excellent thermal properties compared with petroleum-based bisphenol A phthalonitrile resin. The results also demonstrate that introducing L-tyrosine into thermosets is feasible and can simultaneously impart excellent performances to the materials with relatively high level of biomass.

Increasing rice production to feed the world’s growing population while protecting the environment requires more optimal use of fertilizers. In China, the current high input, high output and high reliance on synthetic nitrogen (N) fertilizer in agriculture has resulted in high N losses, especially ammonia (NH 3 ) emission. Urea combined with green manure (GM) might be a promising approach to improve N fertilizer management. However, few studies have evaluated duckweed in this manner. Duckweed does not require arable land for cultivation and thus avoids competition with food crops. Therefore, a field experiment was conducted for three years with five treatments (CK, no N-fertilizer; CT, conventional practice, urea alone at 300 kg N ha −1 ; CTD, urea combined with duckweed at 300 kg N ha −1 ; RN, urea alone at 225 kg N ha −1 ; and RND, urea combined with duckweed at 225 kg N ha −1 ) in an intensive rice cropping system in the Taihu Region of China. The results for two years showed that urea combined with duckweed cover reduced NH 3 loss by 36–52% over CT. This reduction was attributed primarily to the formation of a physical barrier and the uptake of NH 4 + by duckweed. The 15 N recovery for 15 N balance conducted for one year was 38% higher and the 15 N loss was 16% lower for CTD than that of CT. Furthermore, urea combined with duckweed increased N accumulation in the aboveground plants by 14–25% over CT for the 3 years. As a result, urea combined with duckweed achieved higher rice yield by 9–10%, and higher net economic benefit by 10–11% over CT for the 3 years; however, using the conventional rate of 300 kg N ha −1 did not increase rice yield over using the reduced N rate of 225 kg N ha −1 , with or without duckweed. Thus, duckweed as GM combined with chemical fertilizer application provided an approach for increasing the rice yield without increasing inputs of N fertilizer and thereby provided a financially attractive option for farmers to achieve environmental integrity and ensure food security in rice production.

We reported an enzyme-free ELISA to detect breast cancer biomarker human epidermal growth factor receptor 2 (HER2) in human serum samples. Instead of enzymes (such as horseradish peroxidase) used in traditional ELISA, CuO nanoparticles were utilized as the signal probe. Compared to traditional enzymes, CuO nanoparticles have the advantages of low cost and good stability. After dissolving CuO nanoparticles with acid, the Cu (II) ions generated catalyzed the reaction of o-phenylenediamine with ascorbic acid to produce fluorescent quinoxaline derivative molecules. The immunoassay displays high sensitivity and good selectivity towards HER2 with detection limit as low as 9.65pg·mL-1. The assay was successfully applied to the analysis of HER2 in serum of breast cancer patients. The analysis results demonstrated the HER2 level in the serum samples determined by our assay were in good agreement with those determined by commercial HER2 ELISA kit. This enzyme-free ELISA assay can be easily adapted to the detection of other analytes. With these merits, the simple, sensitive and cost effective fluorescence immunoassay shows great potential for clinical applications.

In this work, an ultralight porous carbon foam with excellent electromagnetic interference (EMI) shielding properties was successfully prepared derived from coassembly of graphene oxide and the adenine-polyimide. The structure and performance of the coassembled carbon foam were studied by SEM, XRD, Raman spectroscopy, XPS, etc. The introduction of graphene is conducive to the construction of a conductive network, the retention of nitrogen, the preferred conversion of N-X nitrogen, the increase in porosity, and the graphitization of the carbon layer. The carbon foam showed high electrical conductivity (0.22–0.55 S/cm). In the X-band (8.2–12.4 GHz), outstanding EMI performance was obtained in the values of EMI SE (48.96 dB), SSE (8370.8 dB cm3/g), and SSE/d (19789 dB cm2/g). Furthermore, the carbon foams showed compression recoverability and absorption capability for organic solvents.

A novel full-aromatic dicyanoimidazole (DCI) resin monomer—2,2'-((1,4-phenylenebis(oxy))bis(4,1-phenylene))bis(1H-imidazole-4,5-dicarbonitrile) (4PODCI)was synthesized by a simple Schiff base route. A variety of research methods (including FT-IR, UV–Vis, molecular simulation, model monomer, etc.) were applied to study the curing behavior of 4PODCI, the results show that the curing reaction of 4PODCI can be accelerated by N–H on the imidazole, and triazine is observed in the cured products. The 5% weight loss (T5%) of cured 4PODCI under nitrogen and air atmosphere is as high as 591 °C and 558.5 °C respectively, and its Tg is above 500 °C. These results confirm the excellent thermal and thermomechanical properties of cured 4PODCI, and DCI can be employed as a new type of cross-linked elements of high-performance thermosetting resin.

The addition curing polymer (CN-PcP) containing [2.2]paracyclophane and phthalonitrile was prepared. The results indicated that carbon radical resulting from [2.2]paracyclophane at high temperature could effectively promote the curing reaction of phthalonitrile. The curing behaviors of CN-PcP were studied by differential scanning calorimetry (DSC) and rheological analysis. Thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) revealed that the cured resin of CN-PcP showed high glass transition temperature and outstanding thermal properties.

Due to the simplicity of the exhaust gas aftertreatment system, the heavy-duty natural gas spark ignition (SI) engines play an important role in achieving the macro targets of the reduction of petroleum consumption, carbon and harmful emissions. Considering that power-to-methanol is economically more feasible than power-to-methane, methanol is proposed to continue the advantages of natural gas engines. Based on the fuel properties of methanol and our researching experience, methanol mixture preparation and flow within the cylinder are the most significant. A novel high-pressure port fuel injection (PFI) system is utilized to promote atomization and evaporation of methanol. The effects of the injection strategy, including injection pressure (pinj) and injection timing (αinj), and excess air–fuel ratio (λ) on the mixture formation were simulated and then studied by engine experiments. Three-dimensional simulation and engine tests were conducted under the condition of 1500 rpm and the brake mean effective pressure (BMEP) of 0.854 MPa. pinj varied from 8 MPa to 24 MPa by 4 MPa, αinj was from 240°CA BTDC to 400°CA BTDC by 40°CA and λ was set to be 1.1,1.2 and 1.3, respectively. Simulation results indicate that the mixture homogeneity can be promoted by the optimized injection strategy. The mixture is the most homogeneous at αinj = 340 °CA BTDC and pinj = 8 MPa and the most inhomogeneous at αinj = 400 °CA BTDC and pinj = 24 MPa when λ = 1.2. The experimental results indicate that the more homogeneous mixture can improve engine brake thermal efficiency by shortening CA0-10 and CA10-90 as well as methanol lean-burn. The optimized injection strategy can improve the brake thermal efficiency by 2.6%, 2.7% and 2.8% when λ = 1.1, 1.2 and 1.3, respectively.

Abstact The pyrolysis behaviors of bio-based adenine containing phthalonitrile resin (ADCN) processed by powder metallurgy-like process are studied through the thermogravimetric analysis (TGA), thermogravimetry coupled with Fourier Transform Infrared Spectroscopy and Mass Spectrometry (TG-FTIR-MS), X-Ray photoelectron spectroscopy (XPS) and Raman spectra. The results indicate the pyrolysis process of ADCN resin can be dived into four stages. In the first stage (400–500 °C), The weight loss of the sample is small which may be caused by the volatilization of some oligomers. The second and third stages (500–820 °C) correspond to the major degradation process, where the release of small molecular compounds including HCN, NH3, CH4, CO2, CO, H2O, benzene and its derivatives. In addition, the release amount of HCN is more than other phthalonitrile (PN) systems. In the fourth stage (600–1000 °C), with the increase of temperature, the degree of disorder in carbon material increase, and the forms of nitrogen transform from pyrrolic nitrogen (N-5) and pyridinic nitrogen (N-6) to quaternary nitrogen (N-Q), which is benefit for the application of carbon materials in the electrical field.

Hydroxy-containing low molecular weight poly(2,6-dimethyl-1,4-phenylene oxide) (rPPO) and self-promoted hydroxycontaining phthalonitrile (HPPH) were prepared by redistribution reaction and the simple nucleophilic displacement of a nitro-substituent from 4-nitrophthalonitrile in a dipolar aprotic solvent respectively. The hydroxy-containing phthalonitriles modified by rPPO were prepared by mechanical blending without compatibilizer, followed by heating. The curing behavior was studied using dynamic rheological analysis, and the results showed that the rPPO-modified phthalonitrile exhibited a large processing window (over −67 °C) and complex viscosity (0.18−0.8 Pa·s) at moderate temperatures. After curing at 300 °C, the resulting polymers showed good thermal stability and high modulus as observed by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The dielectric properties and the morphology of rPPO-modified phthalonitrile networks were studied by dielectric analysis and field-emission scanning electron microscopy (SEM).

A series of polymer blends were prepared from 1,3-bis(3,4-dicyanophenoxy)benzene (3BOCN) and epoxy resin with methyl tetrahydrophthalic anhydride as curing agent. The curing behavior and curing kinetics of the blends were studied by differential scanning calorimetry. The apparent activation energy of the blends with various contents of 3BOCN was higher than that of the blends without 3BOCN. A model experiment suggested that there is no obvious reaction between phthalonitrile and epoxy. The thermal and mechanical properties of the polymer blends were evaluated. The polymer blends exhibit high storage modulus and char yield compared with the neat epoxy. The polymer blends show ductile fracture morphology by scanning electron microscopy (SEM) images.

We have developed a new DNA self-assembly amplification technology that generates electric current for electrochemical biosensing. The new technology was used for detection of human epidermal growth factor receptor 2 (HER2). In our technology, an aptamer was utilized both as a ligand for recognition and as a signal generating reporter. The aptasensor is based on a sandwich format and a DNA primer on a HER2 aptamer initiates auxiliary DNA self-assembled on the electrode to form a long one-dimensional DNA. The resulting DNA is then reacted with molybdate to generate electrochemical current. The sensitivity of the aptasensor with DNA self-assembly was greater than that of the aptasensor without DNA self-assembly due to the extended length of the DNA strand. Aptasensor analysis of HER2 in serum of breast cancer patients and healthy individuals is highly correlated (R2 = 0.9924) with ELISA measurements, with a p value of 1.37 × 10–7. The analysis of HER2 in serum (confirmed by ELISA) suggests that HER2 levels ...

The paper describes a colorimetric sandwich enzyme-linked immunosorbent assay (ELISA) for the determination of human IgG. It is based on the use of an Fe(II) coordination complex as a signal amplifier and of mesoporous silica nanoparticles modified with glucose oxidase (GOx) and secondary antibodies (Ab2). After formation of the immuno sandwich complex, the quantity of GOx is proportional to the quantity of IgG. On addition of Fe(II) and glucose, GOx catalyzes the oxidation of glucose to produce hydrogen peroxide which oxidizes Fe(II) to Fe(III). After adding a stop solution containing the complexing ligand 1,10-phenanthroline (Phen), un-reacted Fe(II) forms an orange-red complex with Phen which can be detected by plate reader and even seen with bare eyes. This sandwich ELISA has a linear response in the 1 pg.mL−1 to 100 ng.mL−1 human IgG concentration range and a 860 fg.mL−1 detection limit. This is 20 times lower than the commercial ELISA for human IgG. The assay also is selective, stable, highly sensitive and cost-effective.

Three-dimensional (3D) nitrogen and sulfur dual-doped graphene aerogels (NSGAs) are successfully synthesized by using a rational hydrothermal self-assembly process with ammonia and sulfur powder as nitrogen and sulfur sources, respectively. Structural characterization, including TEM, HAADF-STEM, SEM, and XPS indicated that the NSGA catalyst exhibits an interconnected macroporous framework of graphene sheets and tunable contents of N and S. The as-prepared NSGAs show an excellent electrocatalytic activity for the oxygen reduction reaction, including a highly positive onset potential, high kinetic limiting current density, and fuel tolerance. In particular, the NSGA catalyst reveals a much better long-term stability than that of Pt/C in alkaline medium.

Binary blends composed of benzimidazole-containing phthalonitrile (PNBI) and epoxy resin E51 were prepared. The PNBI/E51 (PE) blends showed good compatibilities and unique synergistic curing behaviors on full consumption of nitrile groups (PE19, PNBI:E51 = 1 : 9 in weight ratio) and epoxy groups in the view of DSC, rheology and IR. Curing procedures of the PE blends were determined by DSC and DMA. Studies on the curing procedure showed that the PE blends exhibited good processability and could be fully cured at a temperature lower than 210 °C. Studies on the cured PE blends showed that they have excellent thermal and mechanical properties. The glass transition temperatures (Tg) of cured PNBI/E51 blends were higher than 207 °C (obtained by DMA). The 5% weight loss (T5) and char yield at 800 °C (CR) were higher than 360 °C and 14% in nitrogen, respectively (obtained by TGA). Consequently, this study shows a novel modification in the method for the preparation of epoxy or phthalonitrile blend systems.

"All-in-one" nanodrugs integrating various functionalities into one nanosystem are highly desired for cancer treatment. Coordination nanosheets as one type of two dimensional (2D) nanomaterials offer great opportunities, but there is lack of enough candidates. Here, a new kind of coordination nanosheets based on phthalocyanine are constructed. Manganese phthalocyanine (MnPc) tetracarboxylic acid is employed as photoactive ligand to form MnPc nanosheets; meanwhile, hyaluronic acid (HA) is coated on their surface. The obtained MnPc@HA nanosheets exhibit superior near-infrared (NIR) photothermal effect with photothermal conversion efficiency of 72.3%, much higher than those of the previously reported photothermal agents. Due to their 2D nanostructures, MnPc@HA nanosheets possess superhigh drug-loading capacity for chemotherapy drug curcumin. With HA as a targeting group, the nanosheets selectively accumulated in CD44 overexpressed tumors, followed by drug release under the control of NIR light. Moreover, MnPc@HA nanosheets with intrinsic paramagnetism can serve as T1 contrast agent for magnetic resonance imaging. The synergistic effect of phototherapy and chemotherapy endows curcumin-loaded MnPc@HA nanosheets with superior tumor-eradicating efficacy. Besides, MnPc@HA nanosheets are biocompatible and safe for biomedical applications. This work provides novel insight for developing new multifunctional platforms based on 2D coordination nanosheets to synergistically combat cancer.

The preparation of high-performance thermosets from sustainable raw resources is a vital research topic in current society faced with the pressure of resource shortage and environmental deterioration. In this work, the cyclic peptide dominated hydrogen bonding physical cross-linking network (HB–PCN) and promoted nitrile reaction produced chemical cross-linking network (NC–CCN) were utilized to achieve the target. A novel bio-based thermoset was prepared by co-polymerization of 70% of tyrosine cyclic peptide (TCP) and 30% of 1,3-bis(3,4-dicyanophenoxy) (3BOCN). Thermal analysis was applied to determine the unique curing behavior of this system. The cured resin exhibits excellent thermal properties and relatively high glass transition temperature (Tg), which embodies the characteristics of typical high-performance polymers and reaches a trade-off between biomass content and performance. The curing reaction pathway of this system was reasonably proposed by Fourier-Transform Infrared Spectroscopy (FT-IR) analysis. Moreover, scanning electron microscope (SEM) confirmed that TCP-3BOCN blend could form porous material via ambient-molding and hot-sintering process. Ultraviolet–visible (UV–Vis) spectrometer was employed to quantitatively describe the adsorption capability of the porous materials to methyl violet.

Graphite phased carbon nitride and indium silver molybdate [g-C3N4 / AgIn(MoO4)2]photocatalytic materials were prepared by hydrothermal method. X-ray diffraction, transmission electron microscope, scanning electron microscope, X-ray photoelectric spectrum, UV-vis diffuse reflection spectrum and solid fluorescence were used to analyze its structure and morphology. The results showed that the catalytic activity of g-C3N4 / AgIn(MoO4)2 was significantly higher than that of pure g-C3N4 and AgIn(MoO4)2 under visible light irradiation. Under the conditions of g-C3N4 and AgIn(MoO4)2 with a compound ratio of 2:1 and hydrothermal reaction at 120℃ for 6 hours, the degradation efficiency of tetracycline hydrochloride was the best. After 1 hour of light reaction, the degradation rate of tetracycline hydrochloride could reach 75.3%. g-C3N4/AgIn(MoO4)2 is expected to be a promising photocatalyst for wastewater treatment.

In this paper, three phthalonitrile (PN) model compounds containing benzene ring-linked alkyl units, bisphenol A (methyl) phthalonitrile monomer (BPAh), bisphenol E (methyne) phthalonitrile monomer (BPEh) and bisphenol F (methylene) phthalonitrile monomer (BPFh), were synthesized. It was confirmed that methylene/methyne could effectively promote the curing reaction of phthalonitrile. Rheology analysis showed that the promotion effect of methylene is stronger than that of methyne, but methyl has no obvious promotion effect. The effect of DPPH on the reaction rate, added considerable evidences that the curing reaction of BPEh and BPFh involved a free radical process. Qualified thermal properties were investigated by Dynamic mechanical analysis (DMA) and thermal gravimetric analysis (TGA). For post-cured resin of BPEh and BPFh, the Tg is more than 500 °C, the T5% were observed at 495 °C and 491 °C, and the char yield in 800 °C reached 73.1% and 71.9% respectively.

Alzheimer's disease (AD) is the most common type of progressive neurodegenerative disorder, and is responsible for the most common form of dementia in the elderly. Inflammation occurs in the brains of patients with AD, and is critical for disease progression. In the present study, the effects of rapamycin (RAPA) on neuroinflammation lipopolysaccharide (LPS)-induced were investigated. SH‑SY5Y human neuroblastoma cells were treated with 20 µg/ml LPS and 0.1, 1 or 10 nmol/l RAPA, and were analyzed at various time points (6, 12 and 24 h). The mRNA expression levels of interleukin (IL) 1β, IL6 and hypoxia‑inducible factor 1α (HIF1α) were determined using reverse transcription‑quantitative polymerase chain reaction. The protein expression levels of phosphorylated (p‑)S6, p‑nuclear factor κB (NFκB), p‑inhibitor of NFκB kinase subunit β (IKKβ) and p‑tau protein were measured by western blot analysis. p‑IKKβ, p‑NFκB, p‑S6 and p‑tau were significantly decreased at 6, 12 and 24 h when cells were treated with ≥0.1 nmol/ml RAPA. In addition, female Sprague Dawley rats were intracranially injected with a single dose of 100 µg/kg LPS in the absence or presence of 1 mg/kg RAPA pretreatment. Brain tissues were subjected to immunohistochemical analysis 6‑24 h later, which revealed that the expression levels of HIF1α and p‑S6 in rat cerebral cortex were increased following LPS injection; however, this increase was abrogated by RAPA treatment. RAPA may therefore be considered a potential therapeutic agent for the early or emergency treatment of neuroinflammation.

Blends of phthalonitrile ( CN ) and alicyclic imide compounds synthesized from tetrahydrophthalic anhydride ( CC ), methyl tetrahydrophthalic anhydride ( MCC ) and hexahydrophthalic anhydride ( HCC ), respectively, were prepared and characterized. Results from rheological studies demonstrated the scope of a novel Thermal Synergistic Polymerization (TSP) effect between phthalonitrile and the alicyclic imide compounds. FTIR data showed a unique phenomenon, which is, the C N of the phthalonitrile compound could be completely and rapidly consumed without generating any triazine ring. Further works on cured products of CC / CN system showed comparable or even higher thermal oxidation stability, low boiling water absorbance and moderate dielectric constant ( e′ in the range of 4.8∼4.5) with almost no voids compared with that of the phthalonitrile resins promoted by traditional curing system of active hydrogen. Model system was designed to study the mechanism of TSP effect of alicyclic imide moiety/phthalonitrile. The systematic characterizations by FTIR, UV–Vis, MALDI-TOF MS, free radical scavenger (DPPH), EPR, etc. showed that the TSP reaction undergoes both copolymerization and homopolymerization with no triazine formation, involving a free radical process. Structural analysis of the oligomers suggested that phthalocyanine rings were a minor component of the thermoset networks, while polyisoindolines were the primary structural motif.

The aim of the present study was to develop layered double hydroxide (LDH) nanoparticles coated with PEGylated phospholipid membrane. By comparing the size distribution and zeta potential, the weight ratio of LDH to lipid materials which constitute the outside membrane was identified as 2:1. Transmission electron microscopy photographs confirmed the core-shell structure of PEGylated phospholipid membrane coated LDH (PEG-PLDH) nanoparticles, and cell cytotoxicity assay showed their good cell viability on Hela and BALB/C-3T3 cells over the concentration range from 0.5 to 50 μg/mL.

A novel methyl tetrahydrophthalic anhydride end-capped imide compound (MODA) was firstly used to promote the curing reaction of phthalonitrile monomer 1,3-bis(3,4-dicyanophenoxy) (3BOCN). The curing behaviors of 3BOCN/MODA blend were studied by differential scanning calorimetry (DSC) and rheological analysis, which suggested that the blend possessed a wide processing window. IR spectra exhibited no triazine has been formed in the curing process and the nitrile group absorption peak almost disappeared after post-cured, the thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) revealed that the cured phthalonitrile resins have excellent thermal properties and high glass transition temperature (Tg).