N′-(5-Bromo-2-hydroxy­benzyl­idene)-4-chloro­benzohydrazide

The title Schiff base, C14H10BrClN2O2, exists in a trans configuration with respect to the C=N bond and the dihedral angle between the two benzene rings is 0.8 (2)°. There is an intra­molecular O—H⋯N hydrogen bond in the mol­ecule, which generates an S(6) loop. In the crystal, inter­molecular N—H⋯O hydrogen bonds link adjacent mol­ecules into extended chains propagating along the c-axis direction

2-Chloro-N′-(5-hydr­oxy-2-nitro­benzyl­idene)benzohydrazide

The mol­ecule of the title Schiff base compound, C14H10ClN3O4, exists in a trans configuration with respect to the acyclic C=N bond. The dihedral angle between the two benzene rings is 62.37 (9)°. An intra­molecular C—H⋯O hydrogen bond is observed. In the crystal structure, adjacent mol­ecules are linked into a ribbon along [10] by O—H⋯O and N—H⋯O hydrogen bonds

2-Chloro-N′-(4-nitro­benzyl­idene)benzo­hydrazide

The title Schiff base compound, C14H10ClN3O3, exists in a trans configuration with respect to the C=N bond. The dihedral angle between the two benzene rings is 15.9 (2)°. In the crystal, the mol­ecules are linked into chains along [101] by inter­molecular N—H⋯O hydrogen bonds

Design and realization of landing-moving integrated gear for mobile lunar lander

For the needs of manned landing, station construction, and material transfer in future lunar exploration missions, the paper proposes a landing–moving integrated gear (LMIG) for mobile lunar lander (MLL), establishes and optimizes the models of cushioning energy-absorbing and movement planning, respectively, and conducts the prototype tests. First, the design requirements of LMIG are given, and the system composition of LMIG and the configuration design of each subsystem are introduced. Second, the effective energy-absorbing model of the aluminum honeycomb is established and experimentally verified, a three-stage aluminum honeycomb buffer is designed and experimentally verified, and the buffer mechanism of LMIG is verified by simulations under various landing conditions. Furthermore, the kinematic and dynamic models of LMIG are established, the moving gait is designed by the center of gravity trajectory planning method, and the driving trajectory during the stepping process is optimized with the goal of minimal jerk of motion. Finally, a cushioning test prototype and a walking test scaled prototype of LMIG are developed, and single leg drop test and ground walking test are carried out. The results show that the established model of LMIG is reasonable, the designed buffer and gait of LMIG are effective, the developed prototypes of LMIG have good cushioning and movement performance, the LMIG’s maximum value of overload acceleration is 6.5g, and the moving speed is 108 m/h, which meets the design requirements

Lentiviral Transgenic MicroRNA-Based shRNA Suppressed Mouse Cytochromosome P450 3A (CYP3A) Expression in a Dose-Dependent and Inheritable Manner

Cytochomosome P450 enzymes (CYP) are heme-containing monooxygenases responsible for oxidative metabolism of many exogenous and endogenous compounds including drugs. The species difference of CYP limits the extent to which data obtained from animals can be translated to humans in pharmacodynamics or pharmacokinetics studies. Transgenic expression of human CYP in animals lacking or with largely reduced endogenous CYP counterparts is recognized as an ideal strategy to correct CYP species difference. CYP3A is the most abundant CYP subfamily both in human and mammals. In this study, we designed a microRNA-based shRNA (miR-shRNA) simultaneously targeting four members of mouse CYP3A subfamily (CYP3A11, CYP3A16, CYP3A41 and CYP3A44), and transgenic mice expressing the designed miR-shRNA were generated by lentiviral transgenesis. Results showed that the CYP3A expression level in transgenic mice was markedly reduced compared to that in wild type or unrelated miR-shRNA transgenic mice, and was inversely correlated to the miR-shRNA expression level. The CYP3A expression levels in transgenic offspring of different generations were also remarkably lower compared to those of controls, and moreover the inhibition rate of CYP3A expression remained comparable over generations. The ratio of the targeted CYP3A transcriptional levels was comparable between knockdown and control mice of the same gender as detected by RT-PCR DGGE analysis. These data suggested that transgenic miR-shRNA suppressed CYP3A expression in a dose-dependent and inheritable manner, and transcriptional levels of the targeted CYP3As were suppressed to a similar extent. The observed knockdown efficacy was further confirmed by enzymatic activity analysis, and data showed that CYP3A activities in transgenic mice were markedly reduced compared to those in wild-type or unrelated miR-shRNA transgenic controls (1.11±0.71 vs 5.85±1.74, 5.9±2.4; P<0.01). This work laid down a foundation to further knock down the remaining murine CYP3As or CYPs of other subfamilies, and a basis to generate CYP knockdown animals of other species

Use of designer nucleases for targeted gene and genome editing in plants

The ability to efficiently inactivate or replace genes in model organisms allowed a rapid expansion of our understanding of many of the genetic, biochemical, molecular and cellular mechanisms that support life. With the advent of new techniques for manipulating genes and genomes that are applicable not only to single-celled organisms, but also to more complex organisms such as animals and plants, the speed with which scientists and biotechnologists can expand fundamental knowledge and apply that knowledge to improvements in medicine, industry and agriculture is set to expand in an exponential fashion. At the heart of these advancements will be the use of gene editing tools such as zinc finger nucleases, modified meganucleases, hybrid DNA/ RNA oligonucleotides, TAL effector nucleases and modified CRISPR/Cas9. Each of these tools has the ability to precisely target one specific DNA sequence within a genome and (except for DNA/ RNA oligonucleotides) to create a double-stranded DNA break. DNA repair to such breaks sometimes leads to gene knockouts or gene replacement by homologous recombination if exogenously supplied homologous DNA fragments are made available. Genome rearrangements are also possible to engineer. Creation and use of such genome rearrangements, gene knockouts and gene replacements by the plant science community is gaining significant momentum. To document some of this progress and to explore the technology’s longer term potential, this review highlights present and future uses of designer nucleases to greatly expedite research with model plant systems and to engineer genes and genomes in major and minor crop species for enhanced food production