Reversible Switching Between Microwave Absorption and EMI Shielding of VO2 Composite Foam.

Developing lightweight composite with reversible switching between microwave (MW) absorption and electromagnetic interference (EMI) shielding is promising yet remains highly challenging due to the completely inconsistent attenuation mechanism for electromagnetic (EM) radiation. Here, a lightweight vanadium dioxide/expanded polymer microsphere composites foam (VO2/EPM) is designed and fabricated with porous structures and 3D VO2 interconnection, which possesses reversible switching function between MW absorption and EMI shielding under thermal stimulation. The VO2/EPM exhibits MW absorption with a broad effective absorption bandwidth of 3.25 GHz at room temperature (25 °C), while provides EMI shielding of 23.1 dB at moderately high temperature (100 °C). This reversible switching performance relies on the porous structure and tunability of electrical conductivity, complex permittivity, and impedance matching, which are substantially induced by the convertible crystal structure and electronic structure of VO2. Finite element simulation is employed to qualitatively investigate the change in interaction between EM waves and VO2/EPM before and after the phase transition. Moreover, the application of VO2/EPM is demonstrated with a reversible switching function in controlling wireless transmission on/off, showcasing its excellent cycling stability. This kind of smart material with a reversible switching function shows great potential in next-generation electronic devices.

Molecular Characterization and Expression Patterns of Two Pheromone-Binding Proteins from the Diurnal Moth Phauda flammans (Walker) (Lepidoptera: Zygaenoidea: Phaudidae).

Sex pheromone-binding proteins (PBPs) play an important role in sex pheromone recognition in Lepidoptera. However, the mechanisms of chemical communication mediating the response to sex pheromones remain unclear in the diurnal moths of the superfamily Zygaenoidea. In this study, Phauda flammans (Walker) (Lepidoptera: Zygaenoidea: Phaudidae) was used as a model insect to explore the molecular mechanism of sex pheromone perception in the superfamily Zygaenoidea. Two novel pheromone-binding proteins (PflaPBP1 and PflaPBP2) from P. flammans were identified. The two pheromone-binding proteins were predominantly expressed in the antennae of P. flammans male and female moths, in which PflaPBP1 had stronger binding affinity to the female sex pheromones Z-9-hexadecenal and (Z, Z, Z)-9, 12, 15-octadecatrienal, PflaPBP2 had stronger binding affinity only for (Z, Z, Z)-9, 12, 15-octadecatrienal, and no apparent binding affinity to Z-9-hexadecenal. The molecular docking results indicated that Ile 170 and Leu 169 are predicted to be important in the binding of the sex pheromone to PflaPBP1 and PflaPBP2. We concluded that PflaPBP1 and PflaPBP2 may be responsible for the recognition of two sex pheromone components and may function differently in female and male P. flammans. These results provide a foundation for the development of pest control by exploring sex pheromone blocking agents and the application of sex pheromones and their analogs for insect pests in the superfamily Zygaenoidea.

Real-Time Visual Biofeedback via Wearable Ultrasound Imaging Can Enhance the Muscle Contraction Training Outcome of Young Adults.

ABSTRACT: Huang, Z-H, Ma, CZ-H, Wang, L-K, Wang, X-Y, Fu, S-N, and Zheng, Y-P. Real-time visual biofeedback via wearable ultrasound imaging can enhance the muscle contraction training outcome of young adults. J Strength Cond Res 36(4): 941-947, 2022-Real-time ultrasound imaging (RUSI) can serve as visual biofeedback to train deep muscle contraction in clinical rehabilitative settings. However, its effectiveness in resistance training in sports/fitness fields remains unexplored. This article introduced a newly developed wearable RUSI system that provided visual biofeedback of muscle thickening and movement and reported its effectiveness in improving the training outcomes of muscle thickness change (%) during dynamic contraction. Twenty-five healthy young men participated and performed pec fly exercise both with and without RUSI biofeedback. Statistical analysis was conducted to examine the reliability of the measurements and the immediate effects of (a) RUSI biofeedback of muscle contraction and (b) training intensity (50 vs. 80% of 1-repetition maximum [1RM]) on the pectoralis major (PMaj) thickness change measured by ultrasound images. In addition to significantly high inter-contraction reliability (ICC3,1 > 0.97), we observed significantly increased PMaj thickness change for both training intensities upon receiving biofeedback in subjects, compared with without biofeedback (p < 0.001). We also observed significantly larger PMaj thickness change at 80% of 1RM compared with 50% of 1RM (p = 0.023). The provision of visual biofeedback using RUSI significantly enlarged the magnitude of PMaj thickness change during pec fly exercises, potentially indicating that RUSI biofeedback could improve the ability of targeted muscle contraction of PMaj in healthy young adults. To our knowledge, this study has pioneered in applying RUSI as a form of biofeedback during weight training and observed positive effectiveness. Future iterations of the technique will benefit more subject groups, such as athletes and patients with neuromuscular disorders.

Exceptional points enhance sum sideband generation in a mechanical PT-symmetric system.

Systems exhibiting parity-time (PT) symmetry are, in general, non-Hermitian systems, in which exceptional points (EPs) emerge when the system transits from the PT-symmetric phase to the broken-PT-symmetric phase. Based on the abnormal exponential amplification effect in EPs, it is often used to generate, control and transmit light in non-Hermitian systems. In this paper, we theoretically analyze the generation of the frequency components at the sum sideband by considering the nonlinear terms of the optomechanical dynamics in a double-probe-field-driven mechanical PT-symmetric system. Using experimentally achievable parameters, we demonstrate that the efficiency of sum sideband generation (SSG) can be significantly enhanced in EPs, even that the efficiency of SSG can be raised by three orders of magnitude compared to the general optomechanical system by adjusting the appropriate system parameters. These results are beneficial to explore the transmission and conversion of light in chip-scale optical communications.

Bound state and non-Markovian dynamics of a quantum emitter around a surface plasmonic nanostructure.

A bound state between a quantum emitter (QE) and surface plasmon polaritons (SPPs) can be formed, where the excited QE will not relax completely to its ground state and is partially stabilized in its excited state after a long time. We develop some theoretical methods for investigating this problem and show how to form such a bound state and its effect on the non-Markovian decay dynamics. We put forward an efficient numerical approach for calculating the analytical part of the self-energy for frequency below the lower energy threshold. We also propose an efficient formalism for obtaining the long-time value of the excited-state population without calculating the eigenfrequency of the bound state or performing a time evolution of the system, in which the probability amplitude for the excited state in the steady limit is equal to one minus the integral of the evolution spectrum over the positive frequency range. With the above two quantities obtained, we show that the non-Markovian decay dynamics of an initially excited QE can be efficiently obtained by the method based on the Green's function expression for the evolution operator when a bound state exists. A general criterion for identifying the existence of a bound state is presented. The performances of the above methods are numerically demonstrated for a QE located around a metal nanosphere and in a gap plasmonic nanocavity. Numerical results show that these methods work well and the QE becomes partially stabilized in its excited state at a long time for the transition dipole moment beyond its critical value. In addition, it is also found that this critical value is heavily dependent on the distance between the QE and the metal surface, but nearly independent on the size of the nanosphere or the rod. Our methods can be utilized to understand the suppressed decay dynamics for a QE in an open quantum system and provide a general picture on how to form such a bound state.

Nocardia colli sp. nov., a new pathogen isolated from a patient with primary cutaneous nocardiosis.

A novel nocardioform strain, CICC 11023T, was isolated from a tissue biopsy of neck lesions of a patient with primary cutaneous nocardiosis and characterized to establish its taxonomic position. The morphological, biochemical, physiological and chemotaxonomic properties of strain CICC 11023T were consistent with classification in the genus Nocardia. Whole-cell hydrolysates were rich in meso-diaminopimelic acid, galactose, arabinose and fructose. Mycolic acids were present. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid and two unidentified lipids, and the predominant menaquinone was cyclo MK-8 (H4, ω-cyclo). The main fatty acids (>5 %) were C18 : 0 10-methyl (TBSA), C16 : 0, summed feature 4 (C16 : 1 trans 9/C15 : 0 iso 2OH), C15 : 0 and C17 : 0 10-methyl. Phylogenetic analyses based on 16S rRNA gene sequences revealed that the isolate is most closely related (>98 % similarity) to the type strains Nocardia ninae OFN 02.72T, Nocardia iowensis UI 122540T and Nocardia alba YIM 30243T, and phylogenetic analysis of gyrB gene sequences showed similarity (89.1-92.2 %) to Nocardia vulneris NBRC 108936T, Nocardia brasiliensis IFM 0236T and Nocardia exalbida IFM 0803T. DNA-DNA hybridization results for strain CICC 11023T compared to Nocardia type strains ranged from 20.4 to 35.4 %. The genome of strain CICC 11023T was 8.78 Mbp with a G+C content of 67.4 mol% overall. The average nucleotide identity (ANI) values between strain CICC 11023T and N. alba YIM 30243T were low (OrthoANIu=77.47 %), and the ANI values between strain CICC 11023T and N. vulneris NBRC 108936 T were low (OrthoANIu=83.75 %). Consequently, strain CICC 11023T represents a novel Nocardia species on the basis of this polyphasic study, for which the name Nocardia colli sp. nov. is proposed. The type strain is CICC 11023T (=KCTC 39837T).

Prevalence and associated risk factors of insomnia among pregnant women in China.

BACKGROUND: Insomnia is common during pregnancy but the prevalence and risk factors of insomnia in Chinese women during pregnancy is not well studied. This study aimed to examine the prevalence of insomnia and its risk factors in Chinese women during pregnancy. METHODS: In this cross sectional study, 436 Chinese pregnant women with Insomnia Severity Index (ISI) ≥ 8 were clinically assessed using the insomnia criteria based on the combination of DSM-IV (Diagnostic and Statistical Manual-4th Edition) and ICD-10 (International Classification of Dieases, 10th Edition). Beck Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS), Pregnancy Pressure Scale (PPS), Perceived physical discomfort level and number, Epworth Sleepiness Scale (ESS), and a general socio-demographic questionnaire were administered. RESULTS: The results showed that about 20% of the pregnant women met the strict diagnosis criteria of insomnia. Independent-samples t-test revealed that several risk factors were correlated with the group with insomnia (N = 84) compared to the group without insomnia (N = 352). Binary Logistic regression analysis found that more significant bed partner influence (OR = 1.92, 95% CI: 1.03-3.60), depressive symptoms (OR = 1.07, 95% CI: 1.00-1.14), daytime sleepiness (OR = 1.07, 95% CI: 1.01-1.14), subjective somatic discomfort (OR = 2.27, 95% CI: 1.11-4.65), kinds of somatic discomfort (OR = 1.14, 95% CI: 1.03-1.27) and later gestation (OR = 1.05, 95% CI: 1.01-1.09) were significantly associated with insomnia. CONCLUSION: In this cohort of Chinese pregnant women, about a fifth of women suffered from clinically significant insomnia. Measures to prevent the adverse effects of insomnia should be provided to pregnant women with depressive symptoms, Sleep disturbance of the bed partner, excessive daytime sleepiness and somatic discomfort, especially late in gestation.

Research Progress on Oviposition-Related Genes in Insects.

Oviposition-related genes have remained a consistent focus of insect molecular biology. Previous research has gradually clarified our mechanistic understanding of oviposition-related genes, including those related to oviposition-gland-related genes, oogenesis-related genes, oviposition-site-selection-related genes, and genes related to ovulation and hatching. Moreover, some of this research has revealed how the expression of single oviposition-related genes affects the expression of related genes, and more importantly, how individual node genes function to link the expression of upstream and downstream genes. However, the research to date is not sufficient to completely explain the overall interactions among the genes of the insect oviposition system. Through a literature review of a large number of studies, this review provides references for future research on oviposition-related genes in insects and the use of RNAi or CRISPR/Cas9 technology to verify the functions of oviposition-related genes and to prevent and control harmful insects.

Generation and enhancement of sum sideband in a quadratically coupled optomechanical system with parametric interactions.

We investigate theoretically the generation and enhancement of sum sideband in a quadratically coupled optomechanical system with parametric interactions. It is shown that the generation of frequency components at the sum sideband stems from the nonlinear optomechanical interactions via two-phonon processes in the quadratically coupled optomechanical system, while an optical parametric amplifier (OPA) inside the system can considerably improve the sum sideband generation (SSG). The dependence of SSG on the system parameters, including the power of the control field, the frequency detuning of the probe fields and the nonlinear gain of OPA are analyzed in detail. Our analytic calculation indicates that the SSG can be obtained even under weak driven fields and greatly enhanced via meeting the matching conditions. The effect of SSG may have potential applications for achieving measurement of electric charge (or other weak forces) with higher precision and on-chip manipulation of light propagation.

Circular RNAs in human and vertebrate neural retinas.

Circular RNAs (circRNAs) belong to an endogenous class of RNA molecules with both ends covalently linked in a circle. Although their expression pattern in the mammalian brain has been well studied, the characteristics and functions of circRNAs in retinas remain unknown. To reveal the whole expression profiles of circRNAs in the neural retina, we investigated retinal RNAs of human, monkey, mouse, pig, zebrafish and tree shrew and detected thousands of circRNAs showing conservation and variation in the retinas across different vertebrate species. We further investigated one of the abundant circRNAs, circPDE4B, identified in human retina. Silencing of circPDE4B significantly inhibited the proliferation of human A549 cells. Functional assays demonstrated that circPDE4B could sponge miR-181C, thereby altering the cell phenotype. We have explored the retinal circRNA repertoires across human and different vertebrates, which provide new insights into the important role of circRNAs in the vertebrate retinas, as well as in related human diseases.

TGF-ß3 Induces Autophagic Activity by Increasing ROS Generation in a NOX4-Dependent Pathway.

Higher concentrations of reactive oxygen species (ROS) have been associated with epithelial cell damage, cell shedding, and airway hyperresponsiveness. Previous studies have indicated that transforming growth factor-beta (TGF-ß) mediates ROS production and NADPH oxidase (NOX) activity. In our previous study, we also observed that TGF-ß3 increases mucus secretion in airway epithelial cells in an autophagy-dependent fashion. Although it is well known that the relationship between ROS and autophagy is cell context-dependent, the exact mechanism of action remains unclear. The following study examined whether ROS act as upstream of autophagy activation in response to TGF-ß3 induction. Using an allergic inflammation mouse model induced by house dust mite (HDM), we observed elevated lung amounts of TGF-ß3 accompanied by increased ROS levels. And we found that ROS levels were elevated and NOX4 expression was increased in TGF-ß3-induced epithelial cells, while the lack of NOX4 in the epithelial cells could reduce ROS generation and autophagy-dependent MUC5AC expression treated with TGF-ß3. Furthermore, our studies demonstrated that the Smad2/3 pathway was involved in TGF-ß3-induced ROS generation by promoting NOX4 expression. The inhibition of ROS generation by N-Acetyl-L-cysteine (NAC) resulted in a decrease in mucus expression and autophagy activity in vivo as well as in vitro. Finally, TGF-ß3-neutralizing antibody significantly reduced the ROS generation, mucus expression, and autophagy activity and also decreased the phosphorylation of Smad2 and Smad3. Taken together, the obtained results revealed that persistent TGF-ß3 activation increased ROS levels in a NOX4-dependent pathway and subsequently induced autophagy as well as MUC5AC expression in the epithelial cells.

Development of a battery-free ultrasonically powered functional electrical stimulator for movement restoration after paralyzing spinal cord injury.

BACKGROUND: Functional electrical stimulation (FES) is used to restore movements in paretic limbs after severe paralyses resulting from neurological injuries such as spinal cord injury (SCI). Most chronic FES systems utilize an implantable electrical stimulator to deliver a small electric current to the targeted muscle or nerve to stimulate muscle contractions. These implanted stimulators are generally bulky, mainly due to the size of the batteries. Furthermore, these battery-powered stimulators are required to be explanted every few years for battery replacement which may result in surgical failures or infections. Hence, a wireless power transfer technique is desirable to power these implantable stimulators. METHODS: Conventional wireless power transduction faces significant challenges for safe and efficient energy transfer through the skin and deep into the body. Inductive and electromagnetic power transduction is generally used for very short distances and may also interfere with other medical measurements such as X-ray and MRI. To address these issues, we have developed a wireless, ultrasonically powered, implantable piezoelectric stimulator. The stimulator is encapsulated with biocompatible materials. RESULTS: The stimulator is capable of harvesting a maximum of 5.95 mW electric power at an 8-mm depth under the skin from an ultrasound beam with about 380 mW/cm2 of acoustic intensity. The stimulator was implanted in several paraplegic rats with SCI. Our implanted stimulator successfully induced several hindlimb muscle contractions and restored leg movement. CONCLUSIONS: A battery-free miniature (10 mm diameter × 4 mm thickness) implantable stimulator, developed in the current study is capable of directly stimulating paretic muscles through external ultrasound signals. The required cost to develop the stimulator is relatively low as all the components are off the shelf.

Towards Wearable Comprehensive Capture and Analysis of Skeletal Muscle Activity during Human Locomotion.

BACKGROUND: Motion capture and analyzing systems are essential for understanding locomotion. However, the existing devices are too cumbersome and can be used indoors only. A newly-developed wearable motion capture and measurement system with multiple sensors and ultrasound imaging was introduced in this study. METHODS: In ten healthy participants, the changes in muscle area and activity of gastrocnemius, plantarflexion and dorsiflexion of right leg during walking were evaluated by the developed system and the Vicon system. The existence of significant changes in a gait cycle, comparison of the ankle kinetic data captured by the developed system and the Vicon system, and test-retest reliability (evaluated by the intraclass correlation coefficient, ICC) in each channel's data captured by the developed system were examined. RESULTS: Moderate to good test-retest reliability of various channels of the developed system (0.512 ≤ ICC ≤ 0.988, p < 0.05), significantly high correlation between the developed system and Vicon system in ankle joint angles (0.638R ≤ 0.707, p < 0.05), and significant changes in muscle activity of gastrocnemius during a gait cycle (p < 0.05) were found. CONCLUSION: A newly developed wearable motion capture and measurement system with ultrasound imaging that can accurately capture the motion of one leg was evaluated in this study, which paves the way towards real-time comprehensive evaluation of muscles and joint motions during different activities in both indoor and outdoor environments.

Quasi-static method and finite element method for obtaining the modifications of the spontaneous emission rate and energy level shift near a plasmonic nanostructure.

We provide numerical demonstrations of the applicability and accuracy of the quasi-static method and the finite-element method in the investigation of the modifications of the spontaneous emission rate and the energy level shift of an emitter placed near a silver-air interface or a silver nano-sphere. The analytical results are presented as a reference. Our calculations show that the finite element method is an accurate and general method. For frequency away from the radiative mode, the quasi-static method can be applied more effectively for calculating the energy level shift than the spontaneous emission rate. But for frequency around, there is a blue shift for both and this shift increases with the increasing of emitter-silver distance. Applying the theory to the nanosphere dimmer, we see similar phenomenon and find extremely large modifications of the spontaneous emission rate and energy level shift. These findings are instructive in the fields of quantum light-matter interactions.

[Study on Autophagy and Apoptosis Induced by Amiodarone Combined with Glycyrrhetinic Acid in HepG2 Cells].

OBJECTIVE: To investigate the effects of amiodarone combined with glycyrrhetinic acid on the activity, apoptosis and autophagy in human hepatoma HepG2 cells. METHODS: After using amiodarone and glycyrrhetinic acid alone or in combination treatment for HepG2 cells, MTT assay was used to detect cell proliferation, Annexin Ⅴ/PI flow cytometry was used to detect apoptosis; Western blot was used to detect the expression of autophagy-related proteins Beclin-1, LC3 and p62. The formation of EGFP-LC3 green fluorescent aggregates was observed under a fluorescence microscope. The effects of autophagy on cell proliferation and apoptosis were studied by autophagy inhibitor hydroxychloroquine (HCQ) and autophagy promoter Rapamycin. RESULTS: The cell viability in combination group was lower than that in single drug group, and the apoptosis rate was higher than that in single drug group. Compared with single-drug group, the expressions of Beclin-1 and LC3Ⅱ protein in the combination group were higher than that in the single-drug group, while the expression of p62 protein was lower in the single-drug group. Fluorescence microscopy results showed that the number of EGFP-LC3 fluorescent aggregates in the combination group were more than that in the single-drug. Using amiodarone and glycyrrhetinic acid treated HepG2 cells, inhibition of auotophagy could decrease cell viability, increase apoptosis rate of cells; promoting autophagy would decrease the apoptosis rate and increase cells viability. CONCLUSION: By increasing apoptosis of hepatocellular carcinoma HepG2 cells and autophagy level, and decreasing the cell activity, amiodarone combining with glycyrrhetinic acid treatment inducing autophagy a protective mechanism for cells.

[Development and application of polymorphic microsatellite markers in Saxifraga genus].

In order to develop genomic-SSR markers for species of Saxifraga genus, a mixed plant genomic DNA sample was sequenced based on high-throughput Illumina MiSeq platform. According to genomic sequencing data, SSR loci were identified with MISA software, and then primers were designed with Primer 3 software. A total of 120 pairs of primers were randomly synthesized and amplified in genomic DNA of a few plant samples. Those primers who have yielded polymorphic bands and were considered easy to amplify were identified. After that, transferability of these primers was evaluated, and phylogenetic relationship of 25 species of Saxifraga genus was analyzed with UPGMA (unweighted pair group method analysis). In our results, 587 256 sequences containing SSRs were identified from a total of 1 881 979 combined read pairs obtained in genomic sequencing. Primers were designated to amplify SSRs containing two to six nucleotide repeat units, screened in a small portion of species. Finally, 17 pairs of primers which have produced abundant of polymorphic bands with little problem were amplified in 25 species of Saxifraga genus. A total of 2 687 polymorphic bands were obtained, the average polymorphic rate was 158 bands per pairs of primers. The transferability rate was ranging from 88.0% to 100% across 25 species of Saxifraga. In phylogenetic analysis, the clustering of 25 species based on 17 pairs of SSR primers was different from morphological classification. Our analysis has provided molecular data for genetic relationship of Saxifraga genus, and the transferable and polymorphic SSRs have provided information for genetic diversity research.

A homologue of vitamin K epoxide reductase in Solanum lycopersicum is involved in resistance to osmotic stress.

Vitamin K epoxide reductase (VKOR) exists widely in the chloroplasts of higher plants and plays important roles in redox regulation. However, investigations of plant VKOR function have primarily focused on VKOR from Arabidopsis, and knowledge concerning this function is therefore quite limited. In this study, Solanum lycopersicum was used to study the function of VKOR. Transcription level analysis revealed that SlVKOR (S. lycopersicum VKOR) expression was upregulated by salt or drought stress. To further investigate the function of SlVKOR in plants, we generated sense and antisense transgenic S. lycopersicum homozygotes at T2 generation plants. Compared with wild-type (WT) plants, the leaf disks of the SlVKOR overexpression plants retained a much higher percentage of chlorophyll after salt or drought treatment, whereas the antisense transgenic plants displayed an opposite response. The overexpressed plants displayed lower levels of H2O2 and superoxide anion radical (O2(·-)) than WT plants, whereas antisense plants accumulated considerably more H2O2 and O2(·-). The activities of reactive oxygen scavenger enzymes, including superoxide dismutase, peroxidase, ascorbate peroxidase and catalase, were consistent with the accumulation of reactive oxygen species. Based on these results, we suggest that SlVKOR is involved in resistance to salt or drought stress.

High-order nonlinear excitations in the Joyeux-Buyukdagli model of DNA.

By means of the semidiscrete multiple-scale method, we study the existence and properties of high-order envelope solitons and discrete breathers in a homogeneous DNA chain model that is based on pairing enthalpies and site-dependent finite stacking. We obtain the analytical solutions for an envelope soliton, and find that at the Brillouin zone center, discrete breather solutions can appear below the bottom of the phonon band. The behavior of two solitons in collisions and the stability of discrete breathers are confirmed by numerical simulations of the exact equations of the system.

[Cloning and tissue expression of mevalonate disphosphate decarboxylase genes from Andrographis paniculata].

Andrographolide is a main bioactive substance in Andrographis paniculata, and extensively used in anti-inflammatory drugs. In order to increase andrographolide production in plant, three 1260 bp ORFs encoding mevalonate disphosphate decarboxylases with 419 amino acids were cloned from A. paniculata by RACE method and analyzed by bioinformatic software. Their tissue expression patterns were predicted by real time PCR. Eleven conserved amino acid residues determining specificity and activity of these MVDs were predicted in these amino acid sequences, but no plastid targeted signal peptides were detected. These MVDs have high similarities with the MVD protein (GenBank number: AEZ55675.1) from Salvia miltiorrhiza. In stems and leaves, expression levels of these MVD genes were constant, and reached the highest level at bud stage and the beginning of flowering. The MVD genes we have cloned from A. paniculata could be used in genetic engineering of andrographolide biosynthsis pathway in future.

Genome-wide characterization and analysis of F-box protein-encoding genes in the Malus domestica genome.

The F-box protein family is a large family that is characterized by conserved F-box domains of approximately 40-50 amino acids in the N-terminus. F-box proteins participate in diverse cellular processes, such as development of floral organs, signal transduction and response to stress, primarily as a component of the Skp1-cullin-F-box (SCF) complex. In this study, using a global search of the apple genome, 517 F-box protein-encoding genes (F-box genes for short) were identified and further subdivided into 12 groups according to the characterization of known functional domains, which suggests the different potential functions or processes that they were involved in. Among these domains, the galactose oxidase domain was analyzed for the first time in plants, and this domain was present with or without the Kelch domain. The F-box genes were distributed in all 17 apple chromosomes with various densities and tended to form gene clusters. Spatial expression profile analysis revealed that F-box genes have organ-specific expression and are widely expressed in all organs. Proteins that contained the galactose oxidase domain were highly expressed in leaves, flowers and seeds. From a fruit ripening expression profile, 166 F-box genes were identified. The expressions of most of these genes changed little during maturation, but five of them increased significantly. Using qRT-PCR to examine the expression of F-box genes encoding proteins with domains related to stress, the results revealed that F-box proteins were up- or down-regulated, which suggests that F-box genes were involved in abiotic stress. The results of this study helped to elucidate the functions of F-box proteins, especially in Rosaceae plants.