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4D printing can be defined as the evolution of 3D printing structure in terms of shape, performance and function. It has time dependence, printer independence and predictability, and its smart dynamic performance creates promising capabilities and broad potential applications. On the basis of a brief review of the status of 4D printing at home and abroad, the concept and components of 4D printing were given firstly. Then the 4D printing was classified from the dimension of printing structure shape change. Furthermore, the key technologies such as printing materials, incentive mechanism and mathematical modeling method in 4D printing elements were analyzed. Finally, it was pointed out that the development direction of 4D printing technology is to combine intelligent materials with 3D printing, simplify the manufacture of complex structures, and realize the automation, intellectualization and personalization applications in special service environments and fields such as aerospace, deep sea and precise medical treatment by using its unique characteristics of self-assembly, self-adaption and self-repairing.

The resistance and the surface morphology of the graphene films were studied after atomic oxygen exposure. The graphene films can be etched away during atomic oxygen exposure, the resistance of graphene films decreases at first and then increases. It shows that the adsorption of oxygen atom may play an important role in the change of the resistance of graphene films at the beginning of the exposure and then the change of the resistance conforms to the law of resistance. The atomic oxygen erosion rate which is about 1.2×10-25cm3/atom to 1.3×10-25cm3/atom can be obtained. A kind of new atomic oxygen detector was put forward based on the relationship between the resistance of graphene films and atomic oxygen fluence.

BACKGROUND: Ionotropic γ‐aminobutyric acid (GABA) receptor (GABAR) in an insect is the major inhibitory receptor and is one of the most important targets for insecticides. Due to the high spatiotemporal resolution of GABAR, the photopharmacological ligands acting on it in vertebrates but not insect have been developed. RESULTS: In this study, two types of photochromic ligands (PCLs) including DTFIPs (DTFIP1 and DTFIP2) and ABFIPs (p‐, m‐, and o‐ABFIP) were synthesized by incorporating photoswitch azobenzene or dithienylethene into fipronil (FIP), which is the antagonist of insect GABAR. Their photomodulation was measured by mosquito larval behavior, and their potential action mechanism was explored by the two‐electrode voltage clamp (TEVC) technique in vitro. DTFIP1 and m‐ABFIP exhibited the most significant difference of insecticidal activity by about 90‐ and 5‐fold to mosquito larvae between non‐irradiated and irradiated formation, respectively, and allowed for optical control of mosquito swimming activity. TEVC assay results indicated that m‐ABFIP and DTFIP1 enable optical control over the homomeric LsRDL‐type GABAR, which is achieved by regulating the chloride channel of resistance to dieldrin (RDL)‐type GABAR by photoisomerization. CONCLUSION: Our results suggested that PCLs synthesized from fipronil provide an alternative and precise tool for studying insect ionotropic GABARs and GABA‐dependent behavior. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND Broflanilide has been registered in China for the control of Lepidoptera and Coleoptera pests, and is widely used to control the target pests at lethal and sublethal levels. The lethal and sublethal effects of broflanilide on the common cutworm (CCW) Spodoptera litura Fabricius, a representative Lepidopteran pest in agricultural crops, were examined to explore its ecological influence on pests. RESULTS: In F0, broflanilide had little influence on the hatchability of eggs, but significantly reduced the neonate survival rate. The lethal activity of broflanilide towards third‐instar larvae and adults was 0.13 mg kg–1 (LD50) and 3.59 mg L–1 (LC50) respectively at 48 h. After being treated with a sublethal dose (LD10 and LD30) of broflanilide, the duration of third‐ to sixth‐instar larvae and the mean fecundity of reproductive females were significantly increased, but pupation rate, weight of pupae and life‐cycle rate were significantly decreased. In F1, the duration of F1 larvae and the doubling time were prolonged, whereas the rates of pupation and the life cycle were decreased by 14.92% and 18.00%, respectively. The intrinsic rate of increase, finite rate of increase and net reproductive rate in the sublethal group were lower than in the control group. The relative fitness of F1 treated by LD10 and LD30 was 0.81 and 0.66, respectively. CONSLUSION: Broflanilide not only has highly lethal activity, but also suppresses the population growth and progeny of CCW, as a critical factor for guidelines of its usage in the field. [ABSTRACT FROM AUTHOR]

BACKGROUND: Neuroligin (NLG) protein is a nerve cell adhesion molecule and plays a key role in the precision apposition of presynaptic domains on inhibitory and excitatory synapses. Existing studies mainly focused on the function of NLG3 against the excitatory channel. However, the interaction between insect NLG3 and ionotropic GABA receptor, which is the main inhibitory channel, remains unclear. In this study, the Nlg3 of common cutworm (CCW), Spodoptera litura Fabricius, one important agricultural Lepidopteron, is selected to explore its function in the inhibitory channel. RESULTS: The SlNlg3 was obtained and the SlNLG3 contains the characteristic features including transmembrane domain, PDZ‐binding motif and type‐B carboxylesterases signature 2 motif. The SlNlg3 messenger RNA (mRNA) was most abundant in midgut, and exhibited multiple expression patterns in different developmental stages and tissues or body parts. Compared with the single injection of SlRDL1, the median effective concentration value of GABA in activating currents was smaller in Xenopus laevis oocytes co‐injected with SlRDL1 and SlNlg3. In addition, SlNlg3 could enhance the GABA‐induced current of homomeric SlRDL1 channel from −391.86 ± 15.41 to −2152.51 ± 30.09 nA. DsSlNlg3 depressed the expression level of SlNlg3 mRNA more than 64.29% at 6 h. After exposure to median lethal dose of fluralaner, the mortality of CCW injected with dsSlNlg3 was significantly decreased by 13.34% and 30.00% at 24 and 48 h, respectively, compared to injection of dsEGFP. CONCLUSION: NLG3 should have physiological function on ionotropic GABA receptor in vitro, which provided a favorable foundation for further research on the physiological function of Nlg gene in Lepidopteron. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The resistance to dieldrin gene (RDL) encodes the primary subunit of the insect ionotropic γ‐aminobutyric acid (GABA) receptor (GABAR), which is the target of phenylpyrazole and isoxazoline insecticides. The splice variants in exons 3 and 6 of RDL, which have been widely explored in many insects, modulate the agonist potency of the homomeric RDL GABAR and potentially play an important role in the development of insects. In the present study, four splice variants of exon 9 were identified in RDL of the small brown planthopper, Laodelphax striatellus (LsRDL), resulting in LsRDL‐9a, LsRDL‐9a', LsRDL‐9b, and LsRDL‐9c. LsRDL‐9a has one more amino acid (E, glutamic acid) compared with LsRDL‐9a', and LsRDL‐9b lacked two amino acids and had seven different amino acids compared with LsRDL‐9c. Two‐electrode voltage‐clamp recording on LsRDLs expressed in Xenopus oocytes showed that alternative splicing of exon 9 has significant impact on LsRDL sensitivity to the agonists GABA and β‐alanine, whereas no significant difference was observed in the potencies of the non‐competitive antagonists (NCAs) ethiprole and fluralaner on the splice variants. Our results suggest that alternative splicing of RDL exon 9 broadens functional capabilities of the GABAR in L. striatellus by influencing the action of GABA. [ABSTRACT FROM AUTHOR]

BACKGROUND: Two‐spotted spider mite (TSSM), Tetranychus urticae Koch is a serious agricultural pest and has developed high levels of resistance to many acaricides. Hence, screening new acaricides is important in the control of TSSM. Fluralaner, a novel isoxazoline, has high activity against agricultural and ectoparasitic pests; however, little information is available about its effects on agricultural mites. Lethal and sublethal effects of fluralaner towards TSSM eggs and female adults were therefore evaluated in this study. RESULTS: Fluralaner exhibited higher activity towards TSSM female adults (LC50, 0.49 mg L−1) compared with commercial acaricides including fenpyroximate, pyridaben and hexythiazox, and also excellent activity towards eggs (LC50, 0.36 mg L−1). The results of a sublethal effect study showed a significant reduction in the duration and fecundity of female adults with increases in the tested concentrations. The net reproductive rate (R0) decreased to 67.34 ± 3.96 and 50.29 ± 3.40 offspring per individual in LC10 and LC30 treatments compared with control (108.31 ± 7.61 offspring per individual). The intrinsic rate of increase (r) and finite rate of increase (λ) in the controls (0.30 and 1.36 d−1) were significantly higher than in the LC30 treatment (0.25 and 1.29 d−1); whereas, they were almost identical to values for the LC10 treatment. No change in mean generation time (T) was observed at sublethal concentrations treatments. CONCLUSION: Our results demonstrated that fluralaner has high acaricidal activity and could be considered a potential acaricide for TSSM management. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]