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Electromagnetically induced transparency (EIT) plays an important role in enhancing nonlinear optical processes at the quantum level. This paper proposes an accessible scheme for realizing high‐efficiency second‐order nonlinear difference‐frequency generation beyond the conventional EIT technique in superconducting circuits. By designing two subsystems to create two transparency windows from Autler–Townes splitting (ATS), a dual‐ATS mechanism is triggered in the scheme. This mechanism leads to an efficient difference‐frequency generation, and the efficiency obtained here can be four orders of magnitude larger than that of the EIT scheme. This study may pave a way for exploring ATS‐enhanced nonlinear optics. [ABSTRACT FROM AUTHOR]

Background and Aim: The role of hypoxia‐inducible factor‐1α (HIF‐1α) and hypoxia‐inducible factor‐2α (HIF‐2α) has been implicated in the clinical prognosis of hepatocellular carcinoma (HCC), but the results remain controversial. We aim to investigate the association of HIF‐1α and HIF‐2α overexpression with the prognosis and clinicopathological features of HCC. Methods: A systematic search was conducted in PubMed, Embase, Scopus, Web of Science, and Cochrane Library until June 20, 2020. Meta‐analysis was conducted to generate combined HRs with 95% confidence intervals (CI) for overall survival (OS) and disease‐free survival (DFS). Odds ratios (ORs) with 95% CI were also derived by fixed or random effect model. Results: Twenty‐two studies involving 3238 patients were included. Combined data suggested that overexpression of HIF‐1α in HCC was not only correlated with poorer OS [HR = 1.75 (95% CI: 1.53–2.00)] and DFS [HR = 1.64 (95% CI: 1.34–2.00)] but was also positively associated with vascular invasion [OR = 1.83 (95% CI: 1.36–2.48)], tumor size [OR = 1.36 (95% CI: 1.12–1.66)], and tumor number [1.74 (95% CI: 1.34–2.25)]. In contrast, HIF‐2α overexpression was not associated with the prognosis and clinicopathological features of HCC. Conclusion: Our data provided compelling evidence of a worse prognosis of HCC in HIF‐1α overexpression patients but not HIF‐2α overexpression ones. [ABSTRACT FROM AUTHOR]

The brown planthopper (BPH) and striped stem borer (SSB) are the most devastating insect pests in rice (Oryza sativa) producing areas. Screening for endogenous resistant genes is the most practical strategy for rice insect‐resistance breeding. Forty‐five mutants showing high resistance against BPH were identified in a rice T‐DNA insertion population (11,000 putative homozygous lines) after 4 years of large‐scale field BPH‐resistance phenotype screening. Detailed analysis showed that deficiency of rice mitochondrial outer membrane protein 64 (OM64) gene resulted in increased resistance to BPH. Mitochondrial outer membrane protein 64 protein is located in the outer mitochondrial membrane by subcellular localization and its deficiency constitutively activated hydrogen peroxide (H2O2) signaling, which stimulated antibiosis and tolerance to BPH. The om64 mutant also showed enhanced resistance to SSB, a chewing insect, which was due to promotion of Jasmonic acid biosynthesis and related responses. Importantly, om64 plants presented no significant changes in rice yield‐related characters. This study confirmed OM64 as a negative regulator of rice herbivore resistance through regulating H2O2 production. Mitochondrial outer membrane protein 64 is a potentially efficient candidate to improve BPH and SSB resistance through gene deletion. Why the om64 mutant was resistant to both piercing‐sucking and chewing insects via a gene deficiency in mitochondria is discussed. [ABSTRACT FROM AUTHOR]

When using RNA interference (RNAi) to study gene functions in Lepidoptera insects, we discovered that some genes could not be suppressed; instead, their expression levels could be up-regulated by double-stranded RNA (dsRNA). To predict which genes could be easily silenced, we treated the Asian corn borer (Ostrinia furnacalis) with dsGFP (green fluorescent protein) and dsMLP (muscle lim protein). A transcriptome sequence analysis was conducted using the cDNAs 6 h after treatment with dsRNA. The results indicated that 160 genes were up-regulated and 44 genes were down-regulated by the two dsRNAs. Then, 50 co-up-regulated, 25 co-down-regulated and 43 unaffected genes were selected to determine their RNAi responses.All the 25 down-regulated geneswere knocked down by their corresponding dsRNA. However, several of the up-regulated and unaffected genes were up-regulated when treated with their corresponding dsRNAs instead of being knocked down. The genes up-regulated by the dsGFP treatment may be involved in insect immune responses or the RNAi pathway. When the immune-related genes were excluded, only seven genes were induced by dsGFP, including ago-2 and dicer-2. These results not only provide a reference for efficient RNAi target predications, but also provide some potential RNAi pathway-related genes for further study. [ABSTRACT FROM AUTHOR]

Numerous studies indicate that target gene silencing by RNA interference (RNAi) could lead to insect death. This phenomenon has been considered as a potential strategy for insect pest control, and it is termed RNAi-mediated crop protection. However, there are many limitations using RNAi-based technology for pest control, with the effectiveness target gene selection and reliable double-strand RNA (dsRNA) delivery being two of the major challenges. With respect to target gene selection, at present, the use of homologous genes and genome-scale high-throughput screening are the main strategies adopted by researchers. Once the target gene is identified, dsRNA can be delivered by micro-injection or by feeding as a dietary component. However, micro-injection, which is the most common method, can only be used in laboratory experiments. Expression of dsRNAs directed against insect genes in transgenic plants and spraying dsRNA reagents have been shown to induce RNAi effects on target insects. Hence, RNAi-mediated crop protection has been considered as a potential new-generation technology for pest control, or as a complementary method of existing pest control strategies; however, further development to improve the efficacy of protection and range of species affected is necessary. In this review, we have summarized current research on RNAi-based technology for pest insect management. Current progress has proven that RNAi technology has the potential to be a tool for designing a new generation of insect control measures. To accelerate its practical application in crop protection, further study on dsRNA uptake mechanisms based on the knowledge of insect physiology and biochemistry is needed. [ABSTRACT FROM AUTHOR]