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The Asian citrus psyllid, Diaphorina citri, is a notorious pest that is an efficient vector for Candidatus Liberibacter asiaticus (CLas), the causal agent of citrus huanglongbing (HLB). The olfactory system of insects is crucial for foraging and mating behavior. Antennae-abundant odorant degrading enzymes (ODEs), including cytochrome P450 (CYPs), are important in degrading redundant odorant molecules to recover the insect olfactory. In this study, to isolate the antennal CYP genes of D. citri, we generated four transcriptomes from female/male antennae and body through deep sequencing of RNA libraries. Seven DcCYP genes preferentially expressed in antennae were first identified by comparing the antennal and body transcriptomes. Phylogenetic analysis grouped four DcCYPs (DcCYP6a13, DcCYP6j1, DcCYP6k1, and DcCYP6a2) into the CYP3 class, whereas DcCYP4d2, DcCYP4c62, and DcCYP4d8 were clustered in the CYP4 clade. qRT-PCR analyses across developmental stages and tissues showed they were antennae-abundant in both genders and constantly expressed from the first instar nymph to the adult. The results presented here highlight the isolation and expression of CYP genes in D. citri antennae, providing valuable insights into their putative role in odorant degradation.

Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), populations exhibit varying levels of resistance to several insecticide classes, including pyrethroids. Artificial laboratory ...

BACKGROUND We investigated rotation using insecticides with multiple modes of action as a resistance management strategy for Asian citrus psyllid, Diaphorina citri, Kuwayama (Hemiptera: Liviidae), in Florida. The stability of thiamethoxam resistance was investigated in the laboratory by establishing populations of field-collected, resistant D. citri and rearing them under no insecticide exposure. Furthermore, recovery of susceptibility was investigated in the field by initiating rotation to insecticides in plots that previously were treated with consecutive thiamethoxam applications. RESULTS The resistance ratio (RR) for thiamethoxam reached between 1266.29- and 1395.00-fold after three and four consecutive applications of thiamethoxam, respectively. However, the RR for thiamethoxam remained low (1.71-5.28-fold) under both rotations at both Lake Alfred and Wauchula. Thiamethoxam was cross-resistant with imidacloprid (RR site 1 = 1059.65-fold, RR site 2 = 1595.43-fold) and clothianidin (RR site 1 = 1798.78-fold, RR site 2 = 1270.57-fold) in the nonrotated treatment at both sites. There was very low cross-resistance to other insecticides with different modes of action. Both laboratory and field investigations indicated that susceptibility to thiamethoxam fully recovered after five D. citri generations. Expression of CYP4C67 was significantly increased in resistant populations. CONCLUSION Our results revealed that D. citri populations develop a high level of resistance following only three or four consecutive neonicotinoid sprays; this was associated with subsequent product failure. Our data suggest that metabolic detoxification by cytochrome P450s contributes to thiamethoxam resistance in D. citri. Overall, the investigation demonstrated that resistance to thiamethoxam can be managed readily in populations of D. citri by rotating modes of action.

Insecticide resistance is an increasing problem in citrus production. The Asian citrus psyllid,Diaphornia citriKuwayama, is recognized as one of the most important citrus pests worldwide and it has developed resistance in areas where insecticides have been overused. The development of insecticide resistance is often associated with fitness costs that only become apparent in the absence of selection pressure. Here, the fitness costs associated with resistance to thiamethoxam and imidacloprid were investigated in three agricultural populations ofD. citrias compared with susceptible laboratory colonies. Results showed that all field populations had greater resistance than laboratory susceptible colonies. For both thiamethoxam and imidacloprid, aCandidatusLiberibacter asiaticus-positive (CLas+) colony was more susceptible than theCLas−colony. Resistance ratios ranged from 7.65–16.11 for imidacloprid and 26.79–49.09 for thiamethoxam in field populations as compared with a susceptible,CLas−laboratory strain. Among three resistant field populations, a significantly reduced net reproductive rate and finite rate of population increase were observed in a population from Lake Wales, FL as compared to both susceptible strains. The fecundity of field populations from Lake Wales, FL was statistically lower than both laboratory susceptible populations. Certain changes in morphological characteristics were observed among resistant, as compared, with susceptible strains. Our data suggest fitness disadvantages associated with insecticide resistance inD. citriare related to both development and reproduction. The lower fitness ofD. citripopulations that exhibit resistance to neonicotinoid insecticides should promote recovery of sensitivity when those populations are no longer exposed to thiamethoxam and/or imidacloprid in the field. The results are congruent with a strategy of insecticide rotation for resistance management.

Hyperproteinemia is a metabolic disorder associated with increased plasma protein concentration (PPC). It is often clinically complicated by malignant diseases or severe infections. Research on the molecular mechanism of High PPC (HPPC) is scant. Here, an animal model of primary hyperproteinemia was constructed in an invertebrate, Bombyx mori, to investigate the effect of HPPC on circulating blood cells. We showed that HPPC affected blood cell homeostasis and enhanced blood cell phagocytosis, leading to increased reactive oxygen species levels, and induced programmed cell death that depended on the endoplasmic reticulum-calcium ion signaling pathway. HPPC induced the proliferation of blood cells, mainly granulocytes, by activating the JAK/STAT signaling pathway. Supplementation with endocrine hormone active substance 20E significantly reduced the impact of HPPC on blood cell homeostasis. Herein, we reported a novel signaling pathway by which HPPC affected blood cell homeostasis, which was different from hyperglycemia, hyperlipidemia, and hypercholesterolemia. In addition, we showed that down-regulation of gene expression of the hematopoietic factor Gcm could be used as a potential early monitoring index for hyperproteinemia.Highlights•HPPC induced proliferation of circulating blood cells through the JAK/STAT pathway, leading to a significant increase in the proportion of granulocytes.•Supplementing endocrine hormone 20E improved hematopoietic function and restored the homeostasis of circulating blood cells through modulation of the JAK/STAT signaling pathway.•HPPC induced PCD in blood cells through the endoplasmic reticulum-calcium ion release signaling pathway.•Down-regulation of the gene expression of the hematopoietic factor Gcm could be used as a potential early monitoring index for hyperproteinemia.

Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is an important economic pest of citrus crops because it vectors the causal pathogen of huanglongbing (HLB, aka citrus greening). Population suppression of D. citri with insecticides has been disproportionally relied on for HLB management and a greater diversity of more sustainable tools is needed. Periglandula spp. is a fungal endosymbiont (family Clavicipitaceae) that forms a mutualistic relationship with members of plants in family Convolvulaceae. This association results in the production of ergot alkaloids that were previously documented as having psyllicidal properties. We investigated the mortality and behavior of D. citri exposed to crude extracts from morning glories in the plant family Convolvulaceae, as well as synthetic ergot alkaloids. Nymphs and adults were exposed to the crude plant extracts from Periglandula positive species of Convolvulaceae, as well as five synthetic ergot alkaloids. Treatments were prepared by exposing clippings of citrus to 100 ng/µL of crude extract from Periglandula-positive species of Ipomoea (I. imperati, I. leptophylla, I. pandurata and I. tricolor), and Turbina corymbosa, and from one Periglandula-negative species (I. alba) (100 ng/µL). Mortality of adult and nymphal D. citri was significantly higher than the control after exposure to extracts from I. tricolor and I. imperati. The synthetic ergot alkaloids, lysergol (10–100 ng/µL), ergonovine maleate (100 ng/µL), agroclavine (10–100 ng/µL), and ergosine (10–100 ng/µL) increased mortality of D. citri nymphs, while ergosine (100 ng/µL) and agroclavine (100 ng/µL) increased mortality of adults compared to water controls. Fewer D. citri adults settled on plants treated with crude extracts or synthetic ergot alkaloids than on water controls at 48 h after release. D. citri that fed on citrus leaves treated with 10 ng/μL solution of crude extract from the Periglandula-positive species Ipomoea (I. imperati, I. leptophylla, I. pandurata, I. tricolor), and Turbina corymbosa excreted significantly less honeydew compared with a negative water control and extract from Periglandula-negative species (I. alba). Our results indicate that crude extracts and ergot alkaloids exhibit toxic and sub-lethal effects on D. citri that could be useful for management of this pest.

Biological modifications of the silk fibroin (silk) material have broad applications in textiles, biomedical materials and other industrial materials. It is economical to incorporate nanoparticles to the biosynthesis of silk fibroin by adding them to silkworm larval diets. This strategy may result in the rapid stable production of modified silk. Glucose-coated silver nanoparticles (AgNPs) were used to improve the AgNPs' biocompatibility, and the AgNPs were efficiently incorporated into silk by feeding. Larvae fed with AgNPs produced silk with significantly improved antibacterial properties and altered silk secondary structures. Both positive and negative effects on the growth and synthesis of silk proteins were observed after different AgNPs doses. Larvae feeding with low concentration of 0.02% and medium 0.20% AgNPs have greater transfer efficiencies of AgNPs to silk compared with feeding high concentration of 2.00% AgNPs. In addition, the elongation and tensile strength of the produced silk fibers were also significantly increased, with greater mammalian cell compatibility. The appropriate AgNPs concentration in the diet of silkworms can promote the synthesis of silk proteins, enhance their mechanical properties, improve their antibacterial property and inhibit the presence of Gram-negative bacteria.

Cladding stainless steel layer on the inner surface of ferrite pressure vessel is a common method to improve the corrosion resistance and save the economic cost. However, the movement of heat source and temperature gradient in the process of cladded welding will lead to the anisotropy of cladded layer material. When measuring the residual stress of pressure vessel steel plate with stainless steel cladded layers by contour method, it is necessary to know the elastic mechanical properties of stainless steel cladded layers accurately. The assumption of transversely isotropy was employed, and the relationship between the material compliance matrix and the elastic modulus of transversely isotropic material was utilized. Based on the elastic modulus of each cladded layer and the whole steel plate from the longitudinal direction (0°) until the transverse direction (90°) measured by the experiment, the independent constants S11, S13, S33 and S44 in the compliance matrix of each cladded layer and the whole steel plate were obtained by regression analysis method. Furthermore, by using the relationship between the independent constants of the stiffness matrix of the transversely isotropic material and the single crystal material, the independent constants S12 in the compliance matrix of each stainless steel cladded layer and the whole steel plate were obtained. And then the independent constants of the stiffness matrix of each cladded layer and the whole steel plate were acquired. Hence, a method for calculating the anisotropic elastic constants of the stainless steel cladded layer and the whole steel plate was proposed. The results will provide material data support for measuring residual stress of pressure vessel steel plate with stainless steel cladded layers by contour method.

Hyperproteinemia is a severe metabolic disease characterized by abnormally elevated plasma protein concentrations (PPC). However, there is currently no reliable animal model for PPC, and the pathological mechanism of hyperproteinemia thus remains unclear. In this study, we evaluated the effects of hyperproteinemia on reproductive development in an invertebrate silkworm model with a controllable PPC and no primary disease effects. High PPC inhibited the synthesis of vitellogenin and 30K protein essential for female ovarian development in the fat body of metabolic tissues, and inhibited their transport through the hemolymph to the ovary. High PPC also induced programmed cell death in testis and ovary cells, slowed the development of germ cells, and significantly reduced the reproductive coefficient. Furthermore, the intensities and mechanisms of high-PPC-induced reproductive toxicity differed between sexes in this silkworm model.

Metabolic disorders of the circulatory system of animals (e.g., hyperglycemia and hyperlipidemia) can significantly affect immune function, however, since there is currently no reliable animal model for hyperproteinemia, its effects on immunity remain unclear. In this study, we established an animal model for hyperproteinemia in an invertebrate silkworm model, with a controllable plasma protein concentration (PPC) and no primary disease effects. We evaluated the influence of hyperproteinemia on innate immunity. The results showed that high PPC enhanced hemolymph phagocytosis via inducing a rapid increase in granulocytes. Moreover, while oenocytoids increased, the plasmacytes quickly dwindled. High PPC inhibited hemolymph melanization due to decreased phenoloxidase (PO) activity in the hemolymph via inhibiting the expression of the prophenoloxidase-encoding genes, PPO1 and PPO2. High PPC upregulated the gene expression of antimicrobial peptides via differential activation of the Toll and Imd signaling pathways associated with NF-κB signaling, followed by an induction of inconsistent antibacterial activity towards Gram-positive and Gram-negative bacteria in an animal model of high PPC. Therefore, high PPC has multiple significant effects on the innate immune function of the silkworm circulatory system.

Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), transmits the causal pathogen of huanglongbing and is a global pest of citrus. D. citri populations exhibit resistance to multiple insecticide modes of action in areas where these chemicals have been overused. We performed genome-wide transcriptional analysis for two field populations of D. citri (Wauchula and Lake Alfred, Florida, USA) that exhibit 1300-fold resistance to the neonicotinoid insecticide, thiamethoxam, and compared it to that of susceptible psyllids collected from the same area and without imposed selection. The Lake Alfred population responded to insecticide resistance by up-regulation of 240 genes and down-regulation of 148 others. The Wauchula population exhibited similar patterns to the Lake Alfred population with up-regulation of 253 genes and down-regulation of 115 others. Gene Ontology annotation associated with cellular processes, cell, and catalytic activity were assigned to differentially expressed genes (DEGs). The DEGs from Lake Alfred and Wauchula populations were mapped to Kyoto Encyclopedia of Gene and Genomes pathways and implicated enrichment of metabolic pathways, oxidative phosphorylation, extracellular matrix-receptor interaction, terpenoid backbone biosynthesis, and insect hormone biosynthesis in the resistant populations. Up-regulation of 60s ribosomal proteins, UDP-gluscoyltransferases, cytochrome c oxidases, and CYP and ABC transporters among thiamethoxam-resistant D. citri implicates a broad array of novel and conventionally understood resistance mechanisms.

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a major pest that transmits phloem-limited, gram negative bacteria including ‘Candidatus’ liberibacter asiaticus (Clas), causing huanglongbing. Management of this pest relies primarily on insecticides, such as the neonicotinoid imidacloprid, that may affect secondary pests including the brown citrus aphid, Toxoptera citricida (Kirkaldy) (Hemiptera: Aphididae). Here, we report on direct toxicity and sublethal dose effects of imidacloprid on T. citricida nymphs and adults following direct contact and ingestion. We also examined transgenerational dose-response and hormetic effects following exposure of T. citricida to a sublethal concentration of imidacloprid. Toxicity of imidacloprid was similar for nymphs (0.6 ng per µL) and adults (1 ng per µL) at 72 h. Fecundity and finite rate of increase were greater for populations exposed to systemic and foliar treatments at a sublethal concentration (0.1 ng per µL) compared with untreated controls. Development times of first instar nymphs in the F1 generation and third instar nymphs in the F2 generation were significantly greater for individuals treated with the sublethal dose than an untreated control. Survival of second instar T. citricida on plants treated with a sublethal concentration also was significantly greater than controls. There also was a significant increase in fecundity of F1 and F2 individuals after sublethal treatment compared with controls. Our results indicated that a sublethal concentration of imidacloprid increased the reproductive performance and induced possible physiologically stimulative (hormetic) effects in T. citricida. Hormesis in secondary pests should be considered when developing a management program for pathogen vectors such as D. citri. Resumen El psilido asiatico de los citricos, Diaphorina citri Kuwayama (Hemiptera: Liviidae), es una plaga importante que transmite bacterias gramnegativas limitadas por el floema, incluyendo Liberibacter asiaticus (Clas), Candidatus, causando la enfermedad huanglongbing. El manejo de esta plaga se basa principalmente en insecticidas, como el imidacloprid neonicotinoide, que puede afectar a las plagas secundarias, incluido el pulgon marron de los citricos, Toxoptera citricida (Kirkaldy) (Hemiptera: Aphididae). Aqui, informamos sobre la toxicidad directa y los efectos de la dosis subletal de imidacloprid en ninfas de T. citricida y adultos despues del contacto directo y la ingestion. Tambien examinamos la respuesta a la dosis transgeneracional y los efectos hormeticos despues de la exposicion de T. citricida a una concentracion subletal de imidacloprid. La toxicidad de imidacloprid fue similar para las ninfas (0.6 ng por µL) y adultos (1 ng por µL) a las 72 h. La fecundidad y la tasa finita de aumento fueron mayores para las poblaciones expuestas a tratamientos sistemicos y foliares a una concentracion subletal (0.1 ng por µL) en comparacion con los controles no tratados. Los tiempos de desarrollo de las ninfas de primer estadio en la generacion F1 y las ninfas del tercer estadio en la generacion F2 fueron significativamente mayores para los individuos tratados con la dosis subletal que un control no tratado. La sobrevivencia del segundo estadio de T. citricida en plantas tratadas con una concentracion subletal tambien fue significativamente mayor que los controles. Tambien hubo un aumento significativo en la fecundidad de los individuos F1 y F2 despues del tratamiento subletal en comparacion con los controles. Nuestros resultados indicaron que una concentracion subletal de imidacloprid aumento el rendimiento reproductivo e indujo posibles efectos fisiologicamente estimulantes (hormeticos) en T. citricida. Se debe considerar la hormesis en plagas secundarias al desarrollar un programa de manejo para vectores de patogenos como D. citri. Key Words: secondary pests; stimulated reproduction; stress conditioning; toxicity; huanglongbing

A relatively new insecticide chemistry for controlling sucking insects, afidopyropen, was investigated for toxicity against Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). We evaluated the mortality of D. citri eggs, nymphs, and adults treated with afidopyropen using both laboratory-reared and field populations. We also quantified the effects of sublethal doses of afidopyropen on D. citri feeding, host choice selection, and fecundity. For laboratory susceptible adults, the contact LC50, topical application LD50, and leaf dip LC50 were 2.13, 2.00, and 3.08 ng/µL, respectively. For adults collected from a commercially managed citrus grove in Florida, the contact LC50, topical application LD50, and leaf dip LC50 were 1.37, 1.92, and 4.89 ng/µL, respectively. Egg hatch was significantly reduced following exposure to afidopyropen at 100 ng/µL. Furthermore, afidopyropen reduced D. citri nymph survival and adult emergence at concentrations ranging between 0.01 and 100 ng/µL. Diaphorina citri adult feeding decreased on citrus leaves treated with afidopyropen in a concentration-dependent manner as measured indirectly by honeydew excretion, and appeared almost completely inhibited after treatment with 10 and 100 ng/µL solutions of afidopyropen. In choice tests, significantly fewer D. citri adults settled on afidopyropen-treated plants than on control plants at 24, 48, and 72 h after release, with no differences in settling between males and females. Afidopyropen reduced the fecundity of D. citri in a concentration-dependent manner. Collectively, the results suggest that afidopyropen could contribute to the integrated management of D. citri and may therefore be useful in rotational programs to improve resistance management.

The Asian citrus psyllid (Diaphorina citri Kuwayama) is known to exhibit abdominal color polymorphisms. In the current study, susceptibility to four insecticides was compared among orange/yellow, blue/green and gray/brown color morphs of field collected D. citri. The LD50 values and 95% fiducial limits were quantified for each insecticide and color morph combination and ranged between 0.10 ng/μL (0.06-0.10) and 6.16 ng/μL (3.30-12.50). Second, we measured the detoxification enzyme activity levels of orange/yellow, blue/green and gray/brown color morphs for cytochrome P450, glutathione S-transferase, and general esterase. The mean P450 activity (equivalent units) was significantly lower in gray/brown (0.152 ± 0.006) and blue/green morphs (0.149 ± 0.005) than in the orange/yellow morphs (0.179 ± 0.008). GST activity (μmol/min/mg protein) was significantly lower in the orange/yellow morph (299.70 ±1.24) than gray/brown (350.86 ± 1.19) and blue/green (412.25 ± 1.37) morphs. The mean EST activity (μmol/min/mg protein) was significantly higher in blue/green (416.72 ± 5.12) and gray/brown morphs (362.19 ± 4.69) than in the orange/yellow morphs (282.56 ± 2.93). Additionally, we analyzed the relative expression of assortment genes involved in cuticular melanization and basal immunity. The transcripts of Dopa Decarboxylase and Tyrosine Hydroxylase were expressed higher in blue/green and gray/brown than orange/yellow morphs. The transcription results paralleled the susceptibility of D. citri to organophosphate, neonicotinoid and pyrethroid insecticides. GST and EST activity may also be correlated with low levels of insecticide susceptibility. Cuticular melanization could be a factor for the development of resistance to insecticides among different color morphs.

Huanglongbing (HLB) or citrus greening is an economically important disease of citrus associated with the bacterium ‘Candidatus Liberibacter asiaticus’. The pathogen is transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama. Currently, insecticide management of D. citri and removal of infected trees are the only means of decreasing HLB infections. Therefore, with continuous use of insecticides, resistance is one of the most important problems facing citrus production. Flupyradifurone is a new generation butenolide insecticide that has been shown to deter insect feeding and reduce pathogen transmission. We determined the concentration-mortality response of D. citri to flupyradifurone. We also quantified sublethal effects of flupyradifurone on D. citri feeding, settling, flight behaviors, as well as, fecundity of females. We found that after 24 and 48 h of exposure, the LC50 was 0.39 ng/μl (0.16–0.82) in a bottle bioassay and 10.43 ng/μl (2.07–55.87) in a leaf dip bioassay, respectively. D. citri that fed on citrus leaves treated with 0.001, 0.02, 0.39, 8.25 and 130.13 ng/μl solution of flupyradifurone excreted significantly less honeydew (8–83%) compared with a negative control; feeding inhibition occurred in a concentration dependent manner suggesting an antifeedant effect of flupyradifurone. There was no effect of flupyradifurone on D. citri settling behavior at 24 and 48 h after leaf treatment. However, there were significantly fewer adults on treated leaves at 72 h after treatment compared to untreated leaves. D. citri exposed to sublethal concentrations of flupyradifurone initiated flight at greater frequency than negative controls. D. citri exposed to sublethal concentrations (LC10 and LC25) of flupyradifurone laid more eggs than those treated with the negative control. Exposure to lethal and sublethal concentrations of flupyradifurone induced hormesis in D. citri with respect to fecundity. Our data indicate that flupyradifurone may be a useful tool for managing D. citri; however, unexpected sublethal effects must be considered when integrating this chemistry into management programs.

The biological toxicity of nanomaterials is a concern because they have many potential applications in biomedical fields. In this study, silkworm hemolymph was exposed to high-dose cadmium telluride quantum dots (CdTe QDs), citric-acid–nitrogen-doped carbon dots (C–NCDs), or silicon nanoparticles (SiNPs) and the differences in the immune responses and programmed cell death induced in hemocytes were compared. Changes in the expression of innate-immunity-related genes and the occurrence of hemocytes in the hemolymph indicated that the three types of nanomaterials entered several types of hemocytes by endocytosis, but their toxicity differed significantly. C–NCDs only induced autophagy in the hemocytes, whereas SiNPs induced both hemocyte autophagy and the simultaneous apoptosis of a large number of cells. CdTe QD exposure rapidly induced hemocyte apoptosis and necrosis. The mechanisms of hemocyte apoptosis induced by the different nanomaterials differed significantly. The apoptosis induced by CdTe QDs was dependent on the lysosomal apoptotic pathway, whereas SiNPs also used the endoplasmic reticulum apoptotic pathway. The autophagy and even apoptosis that appeared in the hemocytes after SiNP exposure quickly self-repaired, whereas the autophagy induced in hemocytes by C–NCD exposure persisted.

Count data with excess zeros are often encountered in many medical, biomedical and public health applications. In this paper, an extension of zero-inflated Poisson mixed regression models is presented for dealing with multilevel data set, referred as hierarchical mixture zero-inflated Poisson mixed regression models. A stochastic EM algorithm is developed for obtaining the ML estimates of interested parameters and a model comparison is also considered for comparing models with different latent classes through BIC criterion. An application to the analysis of count data from a Shanghai Adolescence Fitness Survey and a simulation study illustrate the usefulness and effectiveness of our methodologies.

The silk gland in silkworm (Bombyx mori) is a highly specialized organ that specifically synthesizes silk proteins. A function shift to the synthesis of large quantities of 30K proteins occurs in the degenerating silk gland cells during larval-pupal metamorphosis. The posterior silk gland developmental mutant model of silkworm was used in this study and changes in the programmed cell death (PCD) regulatory signals and 30K protein synthesis during silk gland degeneration were investigated. The results showed that PCD induced by 20-hydroxyecdysone was initiated early during larval-pupal metamorphosis in the mutant, but PCD proceeded slowly, resulting in the degeneration process of the silk gland being extended and took almost twice the time compared with the wild type. Caspase-dependent pathway signals regulated by Dronc in the silk gland cells of the mutant were significantly reduced, while the PCD initiation signal regulated by the Atg family was not delayed or reduced, and PCD-related epigenetic modification such as lysine methylation, acetylation, and succinylation, and tyrosine phosphorylation changed significantly. During the degeneration process in the mutant, 30K proteins were efficiently synthesized in the silk gland cells in stage PP1 even when no caspase protein was detected. Degeneration of the silk gland is a PCD process in which autophagy and apoptosis may participate. The degeneration process was regulated by a caspase-dependent pathway, while the synthesis of 30K proteins along with silk gland degeneration may not be entirely dependent on caspase signals.

Magnetic memory signals and hardness of 35CrMo tempered and quenched steel were acquired during tensile testing. The magnetic signals of 35CrMo steel increased monotonously with the increase of tensile stress before yielding, followed by sudden decrease with further increase of stress after yielding. The zero-cross point ofHp(y) varied during tensile testing, indicating varied position of stress concentration zones with the process of tensile testing. Vickers hardness of the stress concentration zones of 35CrMo steel was lower than that around it, which may be attributed to the residual stress. The relationship between zero-cross point ofHp(y) and Vickers hardness was considered.

The upper and lower courses of sea oil and gas exploitationare connected by submarine pipeline which is called life line project. Free span often occurs because of the unevenness and scour of seabed, and fatigue is one of the main failure modes.In this paper, with the finite element numerical simulation method, based on the harmonic response analysis, the research on the structural response of free span under the vibration induced by vortex was investigated, and the effect of the factors such as flow velocity, length of free span. According to the analysis results,the fatigue life of free span was evaluated.

The creep behavior of 2.25Cr-1Mo-0.25V ferritic steel was investigated using a set of physically-based creep damage constitutive equations. The material constants were determined according to the creep experimental data, using an efficient genetic algorithm. The user-defined subroutine for creep damage evolution was developed based on the commercial finite element software ANSYS and its user programmable features (UPFs), and the numerical simulation of the stress distribution and the damage evolution of the semi V-type notched specimen during creep were studied. The results showed that the genetic algorithm is a very efficient optimization approach for the parameter identification of the creep damage constitutive equations, and finite element simulation based on continuum damage mechanics can be used to analyze and predict the creep damage evolution under multi-axial stress states.

The reheat cracking, also known as stress relief cracking, has occurred many times in the welding coarse grained heat affected zones (CGHAZ) of Vanadium-modified (V-mod) 2.25Cr1Mo steel, but seldom researches on this problem have been conducted until now. In this paper, reheat cracking in welding CGHAZ of V-mod 2.25Cr1Mo steel was studied by the thermo-mechanical simulation methods. A screening test was carried out for simulating similar material to the real CGHAZ. The high temperature ductility of simulated CGHAZ was measured in the range of 600~705°C for determining the most sensitive temperature to reheat cracking. And then, the reheat cracking phenomena at the sensitive temperature was reproduced by Isothermal stress relaxation test and the micro-morphology of cracks was observed and analyzed. The results show that the thermal simulation parameters for acquiring the most similar materials to real CGHAZ are heat input of 35kJ/cm, heating rate of 1000°C/s and holding time at 1320°C of 1s. The reduction of area (RoA) of the simulated CGHAZ specimen first decreases and then increases with increasing temperature. It exhibits a minimum value at 675°C, corresponding to the most sensitive temperature to reheat cracking. In the stress relaxation test, the sample failure typically occurs with very low stress relaxation proportion (less than 15%) and extremely poor ductility (less than 5% in RoA). Both microvoid coalescence along the PAGB and intergranular wedge type cracks were observed in the fractured sample, proposing a mixed cracking mode of W-type and R-type in stress relaxation.

Objective: To explore the clinical efficacy of budesonide in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Methods: A total of 60 patients with moderate and severe AECOPD who were admitted in our hospital from January, 2015 to January, 2016 were included in the study and randomized into the experiment group and the control group. The patients in the two groups were given oxygen inhalation, anti-infection, phlegm dispersing, ipratropium bromide (0.5 mg/time), and aerosol liquid of salbutamol sulfate (2.5 mg/time), 3 times/d, 20 min/time, aerosol inhalation. The patients in the experiment group were given budesonide (2 mg/time), while the patients in the control group were given budesonide (1 mg/time), every 8 h for one aerosol inhalation. The patients in the two groups were continuously treated for 7 d. The changes of PaO2, PaCO2, FEV1, and FEV1/FVC before and after treatment were detected, and the efficacy was evaluated. Results: After treatment, PaO2 and PaCO2 in the two groups were significantly improved when compared with before treatment, and the improved degree in the observation group was significantly superior to that in the control group. After treatment, FEV1 and FEV1/FVC in the two groups were significantly improved when compared with before treatment, and the improved degree in the observation group was significantly superior to that in the control group. The total effective rate in the observation group (93.33%) was significantly higher than that in the control group (76.67%). Conclusions: Aerosol inhalation of budesonide in the treatment of AECOPD in a large dose for a short term can significantly improve the blood gas and pulmonary function.

With the increasing cases of the soft foundation embankment driven by shield tunneling, study on the influence of embankment's security and stability caused by shield tunneling becomes a research focus. The calculated model considering tunnel face pressure and friction stress between shield shell and soil is established, and the influence on embankment's stability and security caused by tunnel depth, tunnel diameter, embankment slope ratio and shield additional pressure are analyzed. The results show: when shield gradually drives to the place at the ahead of slope toe to be about 7.5m, the influence on embankment's safety stability is the most unbeneficial; when the buried depth reaches 2.5 times of the diameter, the effect can be ignored.

Because earthquakes may cause severe damage to buried pipelines, it is important to study dynamic response of buried pipelines. For dynamic response problem of buried pipelines, variational method is the suitable method. In the paper, Gurtin-type quasi-variational principle of buried pipelines dynamics is established by convolutional variational integral method, which is theoretical foundation of finite element method for solving buried pipelines dynamics problems.

In many practical applications, count data often exhibit greater or less variability than allowed by the equality of mean and variance, referred to as overdispersion/underdispersion, and there are several reasons that may lead to the overdispersion/underdispersion such as zero inflation and mixture. Moreover, if the count data are distributed as a generalized Poisson or a negative binomial distribution that accommodates extra variation not explained by a simple Poisson or a binomial model, then the dispersion occurs too. In this paper, we deal with a class of two-component zero-inflated generalized Poisson mixture regression models to fit such data and propose a local influence measure procedure for model comparison and statistical diagnostics. At first, we formally develop a general model framework that unifies zero inflation, mixture as well as overdispersion/underdispersion simultaneously, and then we mainly investigate two types of perturbation schemes, the global and individual perturbation schemes, for perturbing various model assumptions and detecting influential observations. Also, we obtain the corresponding local influence measures. Our method is novel for count data analysis and can be used to explore these essential issues such as zero inflation, mixture, and dispersion related to zero-inflated generalized Poisson mixture models. On the basis of the results of model comparison, we could further conduct the sensitivity analysis of perturbation as well as hypothesis test with more accuracy. Finally, we employ here a simulation study and a real example to illustrate the proposed local influence measures.

In this paper, buckling analysis was carried out on a super-large storage tank under uniform external pressure or wind pressure with finite element method. The critical pressures and buckling deformation modes are obtained and the effects of wind girders and reinforcing rings are investigated. It is found that the critical external pressure of the tank under uniformly applied external pressure obtained by the eigenvalue method is smaller than that obtained by the nonlinear method. Buckling only occurs on the windward side of the tank under the wind pressure. As strengthened by the wind girders and reinforcing rings at the upper par of the tank, buckling deformations here are much smaller than those at the lower part of the tank.

In this paper, a generalized partially linear model (GPLM) with missing covariates is studied and a Monte Carlo EM (MCEM) algorithm with penalized-spline (P-spline) technique is developed to estimate the regression coefficients and nonparametric function, respectively. As classical model selection procedures such as Akaike's information criterion become invalid for our considered models with incomplete data, some new model selection criterions for GPLMs with missing covariates are proposed under two different missingness mechanism, say, missing at random (MAR) and missing not at random (MNAR). The most attractive point of our method is that it is rather general and can be extended to various situations with missing observations based on EM algorithm, especially when no missing data involved, our new model selection criterions are reduced to classical AIC. Therefore, we can not only compare models with missing observations under MAR/MNAR settings, but also can compare missing data models with complete-data models simultaneously. Theoretical properties of the proposed estimator, including consistency of the model selection criterions are investigated. A simulation study and a real example are used to illustrate the proposed methodology.

The present paper proposes a semiparametric reproductive dispersion nonlinear model (SRDNM) which is an extension of the nonlinear reproductive dispersion models and the semiparameter regression models. Maximum penalized likelihood estimates (MPLEs) of unknown parameters and nonparametric functions in SRDNM are presented. Assessment of local influence for various perturbation schemes are investigated. Some local influence diagnostics are given. A simulation study and a real example are used to illustrate the proposed methodologies.