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In this letter, a novel secret merchant‐4 (SM4) cryptographic circuit implementation is proposed against higher order power analysis attacks (PAAs). Four different random number generators (RNGs) are embedded into the SM4 architecture for breaking the correlation between the processed data and monitored power dissipation against PAAs. Firstly, fake keys are created by the first RNG to scramble the critical information related with the actual secret key. Furthermore, the second RNG controls the implementations of substitution boxes (Sboxes) with composite fields or look‐up tables randomly while the third RNG randomizes the substitution locations with respect to these Sboxes. Ultimately, the fourth RNG randomly swaps the behaviors of the fake SM4 and true SM4 to further break the critical correlation. Under the assistance of the four embedded RNGs, the proposed SM4 cryptographic architecture is capable of resisting against fourth‐order PAAs effectively with a 300 Mbps throughput and 165,354 μm2 area after synthesizing in the TSMC 90 nm process design kits (PDK). [ABSTRACT FROM AUTHOR]

In this letter, a high‐speed and low‐latency Ron Rivest‐4 (RC4) encryption algorithm is designed based on SMIC 14 nm process. Since the key issue of limiting the throughput of RC4 encryption algorithm is the swapping operation of S‐box, this proposed design is capable of achieving four swapping operations of S‐box within a clock cycle by utilizing fully combinational logic designs and advanced computations. All 256 swapping operations of key scheduling algorithm (KSA) can be done in 64 clock cycles. Moreover, the novel design greatly improves the encryption efficiency of RC4 since each clock cycle offers 4 bytes of key stream. The whole area can be further optimized by reusing the existing modules, and a lightweight countermeasure is embedded into the RC4 design to break the correlation between the processed data and power dissipation against differential power analysis (DPA) attacks. Finally, the whole design is assessed by the SMIC 14 nm process design kits (PDK). The corresponding clock frequency, throughput, area, and latency, respectively, are achieved as 1 GHz, 32 Gbps, 51,596 μm2, and 74 clock cycles. [ABSTRACT FROM AUTHOR]

Nowadays, ternary organic solar cells (OSCs) based on all‐small molecules have the convenient strategy toward high‐performance and stable devices. Herein, two coumarin‐based dyes C4 and C4–CN are designed and synthesized with a simple synthetic route. The molecules display different intra‐ and intermolecular interactions in the solid state originating from acceptor substitution, as revealed by the single‐crystal structure analysis. The introduction of dicyanomethylene acceptor group in C4–CN plays a synergistic role in molecular packing and orientation in the solid state, thus fostering the elongation of exciton lifetime and improved charge transport in photoactive layer. The optimized C4–CN:AQx–3‐based binary OSCs show a power conversion efficiency (PCE) of 15.07%, which is appreciably higher than the C4:AQx–3‐based OSC (11.39%) due to the appropriate energy‐level alignment, balanced charge transport, favorable phase separation, and lower charge recombination. Furthermore, by introduction of C4–CN as the third component into C4:AQx–3 blend, the ternary OSC shows an improved PCE of 15.34%, which is linked with the enhanced crystallization, optimized morphology, balanced charge carrier mobility, and suppressed recombination with low energy loss. [ABSTRACT FROM AUTHOR]

Summary: False key‐controlled aggressive voltage scaling (FKCAVS) technique is a lightweight and effective leakage power analysis (LPA) attack countermeasure. However, the regular FKCAVS technique may not be utilized as a countermeasure against differential power analysis (DPA) attacks unconditionally. The primary reason is that the working frequency of DPA attacks is significantly higher than the corresponding frequency of LPA attacks. Thus, it is difficult to make the speed of voltage scaling keep pace with the speed of DPA attacks by employing the regular FKCAVS technique. In this paper, a fast FKCAVS technique is proposed to maximize the security of a cryptographic circuit (CC) against DPA attacks while minimizing the corresponding overhead by embedding a machine learning low‐dropout (LDO) regulator (MLLR). As shown in the result, by deploying the proposed FKCAVS technique, the measurement‐to‐disclose (MTD) value against DPA attacks is maintained over 1 million with less than 17.4% power/area overhead. [ABSTRACT FROM AUTHOR]

Summary: In modern integrated circuits (ICs), integrating workload‐agnostic multiphase switched‐capacitor (SC) voltage converters on‐chip is an effective way to reduce the transient response time, improve the security, and boost the power efficiency. However, a stochastic and unbalanced active sequence within the multiphase SC converter may undermine the corresponding output voltage ripple significantly. In this paper, a novel algorithm that is based on Fourier transform is capable of efficiently mitigating the amplitude of output ripple without compromising its security drastically. To achieve this objective, firstly, the output ripple of a single‐phase SC converter needs to be approximated with a Fourier expansion. Then the relationship between the output ripple and active phase sequence of a multiphase SC converter can be modeled precisely under the assistance of Fourier transform. After maximizing the randomness of the active sequences of the multiphase SC converter under different workload conditions and filtering a certain number of phase sequences with unsatisfied output ripples, the optimum control algorithm is generated. As shown in the result, the amplitude of output ripple of a multiphase SC converter can be reduced by 69.5% with negligible security loss and less than 29% power and area overhead under the 55 nm process design kits (PDK). [ABSTRACT FROM AUTHOR]

Summary: Traditional hardware security primitives such as physical unclonable functions (PUFs) are quite vulnerable to machine learning (ML) attacks. The primary reason is that PUFs rely on process mismatches between two identically designed circuit blocks to generate deterministic math functions as the secret information sources. Unfortunately, ML algorithms are pretty efficient in modeling deterministic math functions. In order to resist against ML attacks, in this letter, a novel hardware security primitive named neural network (NN) chain is proposed by utilizing noise data to generate chaotic NNs for achieving authentication. In a NN chain, two independent batches of noise data are utilized as the input and output training data of NNs, respectively, to maximize the uncertainty within the NN chain. In contrast to a regular PUF, the proposed NN chain is capable of achieving over 20 times ML attack‐resistance and 100% reliability with less than 39% power and area overhead. [ABSTRACT FROM AUTHOR]

The choice of molecular material plays a crucial role in improving the performance of organic solar cells. Herein, two coumarin‐based small molecules are designed and synthesized in which the π‐system is extended by the introduction of double bonds. The molecules are differed by the attachment of central acceptor units. The replacement of the carbonyl group in C3 by the dicyanomethylene unit in C3–CN red‐shift the absorption, reduced the energy gap, and stabilized the highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels. When blended with a complementary absorbing all‐fused acceptor F13, the binary devices using C3 donor delivered a power conversion efficiency (PCE) of 11.09%. In contrast, C3–CN:F13‐based binary device displayed an impressive PCE of 14.84% due to the obvious increase in all open circuit voltage, short circuit current density, and fill factor values. The inclusion of CN group to the molecular backbone induces a tighter intermolecular packing, which is beneficial for the charge transport properties. The study demonstrates that the subtle modification in conjugation length and tuning of the energy level by the proper choice of acceptor could be a promising way to improve the device's performance. [ABSTRACT FROM AUTHOR]

The exploitation of new fungicides and the discovery of action targets are effective ways to solve the problem of resistance, and structural optimization of natural products has become an resultful method to discover lead compounds. In this work, in conjunction with the structures of the fungicidal lead compounds h‐I‐9, X‐I‐3, and X‐II‐5 found in our previous project, waltherione F‐derived diamide compounds were synthesized and characterized by 1H NMR, 13C NMR, and HRMS. The biological assays suggested that the target compounds exhibited weak to good fungicidal activity against the tested pathogens, while most of the target compounds displayed high cellular cytotoxicity against Hela cells. The investigation of accidentally discovered fluorescence characteristics revealed that the compound I‐1 exhibited the most vigorous fluorescence intensity at 350 nm, which was significantly higher than that of I‐3 at 225 nm and was further elucidated by density functional theory (DFT) calculations. Overall, the above results would provide theoretical guidance for the design of active target molecules and the development of fluorescent probes. [ABSTRACT FROM AUTHOR]

Summary: Browning decreases the quality and shortens the shelf life of fresh‐cut potato, causing enormous economic losses. This study indicated that nitrogen treatment could inhibit this browning process. However, whether microRNAs (miRNAs) are involved in inhibiting the fresh‐cut potato browning by nitrogen remains unclear. Therefore, nine small RNA libraries were constructed and performed high‐throughput sequencing using fresh‐cut potatoes from control and nitrogen‐treated for 1 h groups at 25 °C to identify the miRNAs and their target genes involved in fresh‐cut potato browning inhibition by nitrogen. The results revealed that four common differentially expressed miRNAs (DEmiRNAs) were identified as associated with browning. The correlation analysis indicated that fresh‐cut potato browning was closely related to the expression of DEmiRNAs and their potential target genes. The miR172d targeting APETALA2/ethylene response factor and phospholipase D, miR482e targeting ATPase GET3‐like, and PC‐3p‐17015_391 targeting stachyose synthase are vital in the nitrogen inhibited fresh‐cut potato browning by regulating the ethylene signalling pathway, membrane lipid metabolic process, ATPase activity, and carbohydrate metabolic process. This study provides new insights into fresh‐cut potato browning inhibition and helps to improve the quality of fresh‐cut potato using nitrogen. [ABSTRACT FROM AUTHOR]

It has been recently demonstrated that the superlubricity behavior of polyalkylene glycol (PAG) aqueous solutions can be achieved in a wide variety of applied conditions. However, certain parameters are expected to be adjusted further to achieve a more controllable superlubricity system. Herein, it is demonstrated that an ultralow friction coefficient can be obtained by concentrated PAG aqueous solutions (80 wt% HB‐260) as the contact pressure becomes relatively low (37 MPa). Meanwhile, the superlubricity state can be adjusted in a timely manner by adjusting the relative sliding speed. Here, the viscosity of the PAG aqueous solution (determined by its concentration and molecular weight) and applied conditions, including contact pressure and relative sliding speed, are considered as critical parameters influencing the lubricating performance. According to the theoretical analysis, the superlubricity state is confirmed and a fitted superlubricity region is proposed, which provides a comprehensive guide for achieving controllable superlubricity in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND Succinate dehydrogenase (SDH) has been identified as one of the most significant targets for fungicide discovery. To date, 23 commercial SDH inhibitor (SDHI) fungicides have been approved for plant protection since the first launch of carboxin in 1966, and extensively applied to combat destructive plant fungi. RESULTS: In this project, 20 novel pyridine sulfide derivatives containing SDH‐based heterocyclic amide fungicide were designed, synthesized, and characterized by proton nuclear magnetic resonance (1H‐NMR), carbon‐13 (13C)‐NMR and high‐resolution mass spectrometry (HRMS). In vitro fungicidal activity experiment, the target compound I‐1 displayed excellent inhibitory rates against the common agricultural pathogens with half maximal effective concentration (EC50) values of 5.2 to 39.8 μg mL−1. The in vivo fungicidal activities demonstrated that the compound I‐1 could effectively prevent Botrytis cinerea from infecting tomato and cucumber leaves with the preventative rates of 67% and 50%. The mitochondrial membrane potential detection, SDH enzyme assay and the molecular docking simulation revealed that the mechanism of action of the compound I‐1 and the relevant interactions with the target enzyme may be similar to those of the control fluopyram. CONCLUSION: The biological activity screening and validation of mechanism of action indicated that the compound I‐1 could be identified as a potential SDH inhibitor for further study. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Ethyl methyl carbonate is selective synthesized from dimethyl carbonate and ethanol via catalytic reactive distillation (RD) over heterogeneous MgO/HZSM‐5. It is shown that 2.3%MgO/HZSM‐5 catalyst has high catalytic activity with 99.4% conversion of ethanol (EtOH) and 98.1% selectivity to EMC, in a RD column. The prepared catalysts is characterized by XRD, SEM, N2 adsorption‐desorption CO2‐TPD and NH3‐TPD. The high performance of this catalyst is attributed to high basicity. According to the results of CO2‐TPD, this catalyst total basicity is 1.72 mmol/g. In order to optimize the catalytic reaction, the reaction conditions, such as amount of catalyst, reflux ratio and EtOH LHSV were studied. [ABSTRACT FROM AUTHOR]

In the wireless power transfer system, the front stage power supply is used to efficiently transfer power to the post-stage circuit. As a bridge connecting the front stage power supply and the rear stage circuit of the wireless power transmission system, power converter network is generally placed behind the inverter so as to achieve output filtering of inverter and stability of output voltage and current. This paper analyses the LCC (inductance-capacitance-capacitance) and LCL (inductance-capacitance-inductance) transform network circuit model, and transmission characteristics of LCC and LCL conversion networks are analysed and compared based on two different circuit topologies. By means of parameter calculation, simulation analysis, and parameter optimisation design, it is concluded that both LCC and LCL networks have different characteristics. The results show that for both LCC and LCL network topologies, when the parameters of network components satisfy certain conditions, they can relatively achieve stable voltage or current output within a certain load range to meet the specific power transmission requirements. [ABSTRACT FROM AUTHOR]

Non-technical summary Optical imaging is widely used to map functional areas of the cerebral cortex. We present a method for fast fluorescence imaging of map-level cortical activity using a calcium indicator protein. Sensory-evoked neuronal activity can be imaged repeatedly in the same mouse over weeks, enabling new opportunities for the longitudinal study of cortical function and dysfunction. We hope this method will be flexibly applied across different cortical areas and to a variety of newly developed genetically encoded calcium and voltage sensors. [ABSTRACT FROM AUTHOR]

Current research indicates that exciton dissociation into free charge carriers can be achieved in material combinations with the highest occupied molecular orbital (HOMO) offset lowered to 0 eV in non‐fullerene organic solar cells. However, the quantitative relationship between the HOMO offset and exciton dissociation has not been established because of the difficulty in achieving continuously tunable HOMO offsets. Here, the binary blends of PTQ10:ZITI‐S and PTQ10:ZITI‐N are combined to form the positive and negative HOMO offsets of 0.20 and −0.07 eV, respectively. While the PTQ10:ZITI‐S binary blend delivers a decent power conversion efficiency (PCE) of 10.69% with a short‐circuit current (Jsc) of 16.94 mA cm−2, the PTQ10:ZITI‐N with the negative offset shows a much lower PCE of 7.06% mainly because of the low Jsc of 12.03 mA cm−2. Because the tunable HOMO levels can be realized in organic semiconducting alloys based on ZITI‐N and ZITI‐S acceptors, the transformation of the HOMO energy offset from negative to positive values is achieved in the PTQ10:ZITIN:ZITI‐S ternary blends, delivering much‐improved PCEs up to 13.26% with a significant, 74% enhancement of Jsc to 20.93 mA cm−2. With detailed investigations, the study reveals that the minimum HOMO offset of ≈40 meV is required to achieve the most‐efficient exciton dissociation and photovoltaic performance. [ABSTRACT FROM AUTHOR]

The article discusses impaired fatty acid utilization in thiredoxin binding protein-2 (TBP-2)-deficient mice. TBP-2-/- mice are predisposed to death with severe bleeding during fasting. Glucose supplementation corrected the fatal anomaly in TBP-2-/- mice, while fatty acids were unable to do so.