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This paper focus on a (N, T) preventive maintenance (PM) policy with lifetime reduction discount rate. In our consideration, the lifetime of component is assumed to be an uncertain variable due to the absence of historical operational data, an uncertain (N, T) PM model with the lifetime reduction in a certain proportion is proposed based on uncertain renewal process. Accordingly, the uncertain model, which minimizes the expected maintenance cost rate, is formulated to find the optimal replacement cycle length T∗ and the number N∗ of preventive maintenance. Finally, a numerical example with sensitivity analysis of parameters is provided to illustrate the proposed model, the results imply that the parameters of cost and lifetime can significantly affect the optimal solutions N∗ and T∗, which can provide a useful reference and guidance for aircraft maintenance decision.

PurposeThe purpose of this paper is to focus on an optimizing maintenance policy with repair limit time for a new type of aircraft component, in which the lifetime is assumed to be an uncertain variable due to no historical operation data, and the repair time is a random variable that can be described by the experimental data.Design/methodology/approachTo describe this repair limit time policy over an infinite time horizon, an extended uncertain random renewal reward theorem is firstly proposed based on chance theory, involves uncertain random interarrival times and stochastic rewards. Accordingly, the uncertain random programming model, which minimized the expected maintenance cost rate, is formulated to find the optimal repair limit time.FindingsA numerical example with sensitivity analysis is provided to illustrate the utility of the proposed policy. It provides a useful reference and guidance for aircraft optimization. For maintainers, it plays an important guiding role in engineering practice.Originality/valueThe proposed uncertain random renewal reward process proved useful for the optimization of maintenance strategy with maintenance limited time for a new type of aircraft components, which provides scientific support for aircraft maintenance decision-making for civil aviation enterprises.

In order to study the compressive strength and crack evolution form of roadside filling body, the strength and acoustic emission of filling body under different loading rates were studied by using PCI-2 acoustic emission tester and pressure testing machine. The crack evolution process of the specimen under different conditions was analyzed, and the compression failure mode, failure mode and internal energy change law of the filling material were obtained, and then the deformation failure and crack evolution law of the filling material were mastered. The results show that the mechanical properties of the filling body are related to the loading rate, while the peak strain is not obviously affected by the loading rate. The cumulative Hit number and cumulative energy of filling materials increase with the increase of loading rate. The higher the Hit number and energy of the filling material, the earlier the internal damage occurs, the earlier the crack evolves, and the easier it is to form instability failure. The abrupt change of the cumulative Hit number and cumulative energy value with time can be used as a reference for entering instability failure.

Understanding regional environmental heterogeneity (EH) and biodiversity relationships (heterogeneity-diversity relationships: HDRs) is the first step toward coupling environmental variables with biodiversity surrogates into regional systematic conservation planning. However, there is no universal method for determining regional HDRs that considers various environmental variables and biodiversity in different regions. This study selected 32 nature reserves as natural areas in Yunnan, China, to examine regional HDRs in Yunnan. We calculated 17 EH parameters (of soil, topography, and climate) and three (ecosystem, plant, and animal) biodiversity indices in the nature reserves. By examining the explanatory power of each EH parameter and area of the nature reserve, we identified the primary parameters and constructed an optimal model for each biodiversity index. The explanatory powers of these parameters varied for each biodiversity index, and those of climatic parameters were generally higher than soil and topographic heterogeneity ones. Heterogeneity of the temperature annual range, followed by area and heterogeneity of soil type, were important parameters for ecosystem diversity of Yunnan and the optimal model explained 56.9%. Plant diversity was explained 54.5% by its optimal model, consisting of heterogeneity of precipitation of the coldest quarter and annual precipitation. Heterogeneity of temperature annual range was important for animal diversity in Yunnan and explained 29.6% of its optimal model. This study suggests that EH parameters can be an effective surrogate for biodiversity, therefore, we suggested that the significance and role of climatically heterogeneous regions for the conservation of biodiversity in Yunnan should be further studied in the future.

Noradrenaline (NE) is closely related to attentive performance and impulsive control. However, the potential sex differences regarding attention and impulsivity under the noradrenergic modulation have been largely neglected. Therefore, our study aimed to investigate whether male and female rats exhibit differential responses to NE-related drugs during the five-choice serial reaction time task (5CSRT). Male and female rats were trained in 5CSRT and administered with different NE drugs after obtaining stable baseline performance: atipamezole, a highly selective α2 receptor antagonist; prazosin, an α1 receptor antagonist; and atomoxetine, a selective NE reuptake inhibitor. Later, prazosin was selected to co-administration with atomoxetine. Male and female rats exhibited equal learning speed, and no significant baseline differences were found as measured by the 5CSRT. Atomoxetine decreased premature responses in both sexes, but the extent of this reduction was different, with the reduction greater in males. Besides, atomoxetine (1.8 mg/kg) increased the error of omissions in females. The high dose of prazosin (0.5 mg/kg) decreased the accuracy only in male rats, but this was ameliorated by the co-administration with atomoxetine. Atomoxetine showed significant improvement in impulsivity, but atomoxetine had less beneficial effects on impulsive control in females than in males, and it even impaired attentional performance in female rats. The α1 receptors were mainly responsible for NE drug-related sex differences in attention rather than impulsivity. The results obtained in this study indicate that the sex differences exist in both attention and impulsivity by the modulation of noradrenaline and raise the concern to improve sex-specific treatments.

Microscale, nanometer to micrometer, is critical to research machining quality of abrasive suspension jet processing (ASJP), in which scale the surface topography of the processing section can be clearly shown and the material removal mechanism can be easily determined. In this paper, an experiment was carried out that three kinds of materials, Ti-6Al-4V (TC4), marble, and glass, cut by abrasive suspension jet (ASJ) and the microscale surface topography captured by an ultra-deep three-dimensional microscope. The experimental results showed that microscale surface topography of the three materials cut by ASJ is different due to their brittleness and toughness. TC4 cutting surface is covered by long and thin scratches with straight down direction, marble cutting surface is covered by pot holes, and glass cutting surface is covered by both of the scratches and pot holes. The scratches are between 40 and 140 microns in length, while the pot holes are between 10 and 40 microns in width. Moreover, forming mechanism of the three materials’ microscale surface topography is also different due to their brittleness and toughness. The scratch on TC4 cutting surface is the plastic damage caused by the abrasive particles, and the pot hole is the brittle fracture caused by the abrasive particles. Intermediate between brittle and plastic materials, glass cut by ASJ with both plastic damage and brittle fracture. The conclusions can provide theory guidance in material precision processing with ASJ.

Opioid use disorder mainly results from functional defects in the brain reward loop, which includs the ventral tegmental area (VTA) and nucleus accumbens (NAc; consisting of shell and core, NAcS and NAcC). Reward effects contribute to opioid use disorder. RMTg M

The material ratio of the roadside backfill body in gob-side entry retaining determines its mechanical properties, which plays an important role in the supporting effect of the roadway surrounding rock. In this paper, a similar material modeling is used to verify the spatiotemporal law of the ground pressure in the engineering case of dense solid backfilling mining in Xingtai Mine, China. Based on that law, the theoretical requirements for the bearing performance of the roadside backfill body are proposed. Finally, a material ratio that meets the theoretical requirements is obtained by compression test, and the deformation and failure characteristics of the backfill body with this ratio are analyzed. The results show that the maximum pressure of the backfill body measured in Xingtai Mine is 5.5 MPa, which is about 40 m away from the coal face, after 40m, the pressure of the backfill body will not increase anymore. The similar simulation test also proved that the ground pressure behind the coal face increases gradually and tends to be stable during the backfilling process, which shows certain spatiotemporal characteristics. Through the proportioning experiment, it is determined that the optimal material ratio of the roadside backfill body is gangue: fly ash: cement = 10:3:1, which meets the theoretical requirement that the strength of the roadside backfill body at any position is not less than the ground pressure at that position. The research results provide a reference for the engineering practice of gob-side entry retaining in dense backfilling mining.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) continues to infect people globally. The increased COVID-19 cases and no licensed vaccines highlight the need to develop safe and effective vaccines against SARS-CoV-2 infection. Multiple vaccines candidates are under pre-clinical or clinical trails with different strengths and weaknesses. Here we developed a pilot scale production of a recombinant subunit vaccine (RBD-Fc Vacc) with the Receptor Binding Domain of SARS-CoV-2 S protein fused with the Fc domain of human IgG1. RBD-Fc Vacc induced SARS-CoV-2 specific neutralizing antibodies in non-human primates and mice, and the antibodies induced in macaca fascicularis neutralized three divergent SARS-CoV2 strains, supporting broader neutralizing ability. Three times immunizations protected Macaca fascicularis (20ug or 40ug per dose) and mice (10ug or 20ug per dose) from SARS-CoV-2 infection respectively, including the protection against SARS-CoV-2 adapted virus MASCp6 which contains N501Y mutation, a key residue increasing binding affinity to human and murine ACE2. These data support clinical development of SARS-CoV-2 vaccines and provide a promising strategy to prevent different stains of SARS-CoV-2 infection. RBD-Fc Vacc is currently being assessed in randomized controlled phase 1/II human clinical trails

Repeated administration of morphine profoundly influences the dopaminergic and cholinergic systems in the nucleus accumbens [including the shell of the nucleus accumbens (NAcS)]. Further, dopamine release is regulated by the cholinergic system, especially the M4 receptor. Drug priming is one of the main factors that induces relapse in drug addiction. The present study first investigated how activation of the M4 receptor in the NAcS affects the expression of morphine-induced behavioral sensitization, through the administration of an M4 agonist (LY2033298) and antagonist (tropicamide), as well as a combination of an acetylcholinesterase inhibitor and M4 antagonist (huperzine-A + tropicamide). Additionally, the influence of a dopamine receptor agonist, in conjunction with an M4 agonist (i.e., SKF38393 + LY2033298), was also examined. Behavioral sensitization was established by exposure to 5 mg/kg morphine once every three days for a total of three exposures. The expression of behavioral sensitization was challenged by 5 mg/kg morphine. Results showed that (1) microinjection of the M4 receptor agonist LY2033298 (0.2 μg/side), but not the antagonist tropicamide (5, 10, or 20 μM/side) into the NAcS blocked the expression of behavioral sensitization; (2) tropicamide (20 μM/side) reversed the inhibition effect of huperzine-A on this behavior; and (3) SKF38393 (1 μg/side) reversed the inhibitory effect of LY2033298 on the expression of morphine-induced behavioral sensitization. These results suggest that the cholinergic M4 receptor in the NAcS plays an important role in the morphine-induced expression of behavioral sensitization through the regulation of dopamine function in rats.

The non-selective muscarinic receptor agonist oxotremorine-M has been found to decrease impulsive choice in high-impulsive (HI) rats and increase impulsive choice in low-impulsive (LI) rats, but little is known about the muscarinic M1 receptor agonist N-desmethylclozapine (NDMC). This study investigated effects of NDMC on impulsive choice, and the effect of co-administration of NDMC with the dopamine D1-like receptor antagonist SCH 23390 or D2-like receptor antagonist raclopride on impulsive choice in HI and LI rats, characterized by basal levels of impulsive choice in a delay-discounting task. The results revealed that NDMC (1 and 2 mg/kg) significantly increased impulsive choice in HI, but not LI rats. SCH 23390 significantly promoted impulsive choice in HI rats at 0.01 mg/kg, and in LI rats at 0.0075 and 0.01 mg/kg. Moreover, SCH 23390 (0.005 and 0.0075 mg/kg) significantly inhibited the increase in impulsive choice induced by NDMC (1 mg/kg) in HI rats, whereas the increase in impulsive choice produced by SCH 23390 (0.0075 mg/kg) was significantly reversed by NDMC (1 mg/kg) in LI rats. Raclopride (0.04, 0.08, and 0.12 mg/kg) did not affect choice in both HI and LI rats, but significantly antagonized the increase in impulsive choice induced by NDMC (1 mg/kg) in HI rats. These findings suggest that D1- and D2-like receptors might be involved in different effects of the M1 receptor agonist on impulsive choice between HI and LI rats.

Center arena activity in open field (OF) test is associated with risk-taking behaviors. Noradrenaline and serotonin (5-HT) are neurotransmitters involved in both center arena activity and risk-based decision-making. However, the effects of noradrenergic/serotonergic systems on risk-based decision-making in rats with different center arena activity levels have not been clearly characterized. In this study, we explored the effects of the noradrenergic and serotonergic systems on risk-based decision-making in long center-time (LCT group) and short center-time (SCT group) rats. The two groups were formed based on performance in OF test. Then we tested their risk-based decision-making using probability discounting task (PDT); rats had to choose between “small/certain” lever that always delivered one pellet and “large/risky” lever that delivered four pellets in a probabilistic manner (100%, 50%, 25%, 12.5%). The results showed the SCT group chose the large/risky lever less often in 12.5% block and were more sensitive to loss than the SCT group. α2-adrenergic receptor agonist dexmedetomidine (0.01 mg/kg) decreased the frequency of risky choice, while the noradrenaline reuptake inhibitor (NRI) reboxetine (10 mg/kg) had the opposite effect only in the SCT group. Serotonin-noradrenaline reuptake inhibitor (SNRI) duloxetine (5 mg/kg) decreased preference for the large/risky option only in the SCT group. In contrast, pharmacological manipulations of the serotonin system did not affect the frequency of risky choices. These results suggest that noradrenergic system may be involved in weighing gains and losses for probabilistic discounting. Our findings also provide a better understanding of the involvement of center arena activity in risk-taking.

Background and Aim The cholinergic system can affect drug reward. The present study aimed to examine the roles of muscarinic acetylcholine receptor (mAChR) and nicotinic acetylcholine receptor (nAChR) in morphine-induced behavioral sensitization. Methods To analyze the roles of mAChR and nAChR in behavioral sensitization induced by morphine (5 mg/kg), seven experiments were designed. Experiment 1 , Experiment 2 examined the effects of 3, 1, and 0.3 mg/kg scopolamine and 0.2, 0.1, and 0.05 mg/kg scopolamine, respectively, on the locomotor activity when administered alone. Experiment 3 , Experiment 4 explored the effect of scopolamine on morphine-induced behavioral sensitization. Experiment 5 studied the effect of mecamylamine on morphine-induced behavioral sensitization. Experiment 6 , Experiment 7 investigated the effects of scopolamine + huperzine A and mecamylamine + huperzine A, respectively, on morphine-induced behavioral sensitization. Results The results revealed that 3 mg/kg scopolamine, which significantly enhanced locomotor activity when administered alone, inhibited the acquisition of morphine-induced sensitization. However, mecamylamine (0.5, 1, 2 mg/kg) did not have these effects. The co-administration of scopolamine (0.05 mg/kg) + huperzine A (0.4 mg/kg) or mecamylamine (1 mg/kg) + huperzine A (0.4 mg/kg) did not affect the acquisition of morphine-induced behavioral sensitization. Scopolamine (0.05 mg/kg) which did not affect the locomotor activity when administered alone, but not mecamylamine (1 mg/kg), reversed the acute attenuation effect of huperzine A (0.4 mg/kg) on morphine-induced locomotor activity at the acquisition stage and reversed the inhibition of huperzine A on the expression of morphine-induced sensitization. Conclusion The mAChR might play a more important role in morphine-induced locomotor activity and the expression of morphine-induced behavioral sensitization. The mechanisms of mAChR and nAChR were relatively separate in morphine-induced sensitization.

Purpose This paper aims to develop a computer simulation processing method to simulate the mining operation of self-advancing semi-continuous mining technology and optimize the shift step of belt conveyor by using simulation modeling framework based on intelligent objects (SIMIO). The method would effectively solve the challenge of field testing such large-scale equipment. Design/methodology/approach The four operational modes of self-advancing semi-continuous mining technology at single bench had been illustrated. The operational system of this technology was analyzed and broken down to single units. By analyzing the time constitution of one operation cycle, the theoretical optimization model of shift step can be established and the optimization criteria is the time utilization ratio being maximum. Once the simulation flow was determined, a three-dimensional (3D) computer simulation model of this mining technology was developed by adapting the SIMIO simulating software to the theoretical model. The models were run to investigate the outputs from different operational modes using geological and mining data from East open-pit mine. Findings The result of these simulations showed that the four-mining-width one-shift (FMWOS) is at maximum production capacity during all operation modes. If transfer equipment is necessary, then this mode can adapt, but system will become more complex. There are minor differences between two-mining-width one-shift and three-mining-width one-shift. If transfer equipment is not necessary, then the two-mining-width one-shift can adapt during actual production. Originality/value The simulation results show that the proposed method can achieve the optimal shift step of a belt conveyor and effectively reduce the time loss caused by the coordination of multiple pieces of equipment while simultaneously improving operational efficiency.

Impulsivity is an important personality trait that affects people's lives every day. Because of the complicated structures and various measurements of impulsivity, the conclusion that whether there were gender differences on impulsivity remained controversial. In our study, we used delay discounting and probability discounting to measure impulsive choice and employed stop signal reaction time task (SSRT) to measure impulsive action within the same subjects. No inherent gender differences were found, either on impulsive choice or on impulsive action. However, after adding a working memory (WM) task, we found an interaction between gender and WM: males made more impulsive choices in the delay discounting task, but females remained no change, and this only occurred when the reward amount was large; in the SSRT, the males showed better inhibitory control under the WM load condition, but females did not. These results demonstrate that gender difference does not exist on impulsivity biologically, but the increased working memory load could affect the gender's sense of delay gratification and the ability of inhibitory control differently. These findings can contribute to the studies of gender differences on impulsivity and draw attention to the need for further research that gender factors should be considered more carefully when exploring the effects of working memory.

Opioids strongly inhibit GABAergic neurons in the rostromedial tegmental nucleus (RMTg) that expresses μ-opioid receptors to induce rewarding and psychomotor effects. M

Acetylcholinesterase inhibitors are regarded as promising therapeutic agents to treat addiction. The current study aimed to examine the effects of huperzine A, a cholinesterase inhibitor, on behavioral sensitization induced by repeated morphine administration and relapse induced by contextual conditioning. The present study also assessed whether the state-dependency hypothesis may explain the results. Adult rats were divided into four groups (n=8) and intraperitoneally injected with 0.2, 0.3 or 0.4 mg/kg huperzine A or saline (1 ml/kg, control), for 5 days. The effect of repeated huperzine A administration alone on locomotor activity was assessed. For the experiments that analyzed the development of morphine-induced sensitization, 40 rats were divided into five groups (n=8): Saline+Saline, Saline+Morphine, 0.2, 0.3 and 0.4 mg/kg huperzine A+Morphine. Following a withdrawal period of 7 days, all animals were administered saline or morphine, as appropriate. To test the state-dependency hypothesis, the rats in the Saline+Morphine group were injected with saline and morphine, while the other three groups were administered different doses of huperzine A and morphine. To examine the effect of huperzine A on the expression of morphine-induced sensitization, the rats in huperzine A+Morphine groups were injected with appropriate concentrations of huperzine A, and morphine. The current results indicated that the administration of huperzine A alone did not affect locomotor activity, while higher doses of huperzine A inhibited the addictive behavior induced by morphine at the development phase. Additionally, huperzine A administration during the expression phase of morphine sensitization did not inhibit the relapse induced by administration of saline. Furthermore, 0.4 mg/kg huperzine A inhibited the expression of morphine-induced behavioral sensitization. Therefore, the results of the current study do not support the state-dependency hypothesis.

Risk perception is an important factor that may mediate risk-based decision-making processes regulated by noradrenergic (NA) and serotonergic (5-HT) systems. Most risk-based decision-making models involve complex factors, such as risk perception or reward value, such that the final decision is the result of the interactions among these factors. However, the contribution of risk perception per se in risk decisions has remained unclear. Therefore, in the present study, we made some modifications to the classical probabilistic discounting task (PDT) to focus on the impact of risk perception and noradrenergic/serotonergic systems on decision-making behavior. Meanwhile, we conducted an elevated plus-maze (EPM) test to detect the correlation between anxiety and choice behavior. In the current study, rats had to choose between a “certain” lever that delivered a certain number of pellets and a “risky” lever that delivered eight pellets in a probabilistic manner (descending: 50%, 25%, 12.5% or ascending 12.5%, 25%, 50% of the time). The long-term rewarding values of the two levers were always identical in each block within each session. According to their baseline performances in choosing the risky lever, rats were divided into the risk-prefer group and risk-averse group. The results showed that there was a significant correlation between open arm time in EPM and risky choice for both descending order and ascending order, indicating that highly anxious rats more often preferred the safe option under risk. Pharmacological stimulation of α2-adrenergic receptors via dexmedetomidine (0.01 mg/kg) decreased the preference of probabilistic rewards in the risk-prefer group, while blocking α2 receptors by atipamezole (0.3 mg/kg) also reduced risky choices. The NA reuptake inhibitor, atomoxetine, increased the preference for risky choices in the risk-prefer group, the effect of which was attained via multiple superimposed doses. Administration of the 5-HT2A receptor agonist, DOI (0.1 mg/kg), increased risk-taking behavior in the risk-prefer group. Taken together, these results suggest that NA may be more inclined to process negative information such as loss or uncertainty in the regulation of risk-related decision making, whereas 5-HT may function primarily to increase risk-taking behavior. Our findings may help to further elucidate how noradrenergic and serotonergic systems differentially affect individuals with different risk preferences in terms of regulating risk perception in risk-related decision making.

Opioids strongly inhibit GABAergic neurons in the rostromedial tegmental nucleus (RMTg) that expresses μ-opioid receptors to induce rewarding and psychomotor effects. M3 and M4 muscarinic receptors are co-localized with μ-opioid receptors at these GABAergic neurons. This study explored whether RMTg M3 and M4 muscarinic receptors are involved in regulating opioid-induced reward and locomotion via a conditioned place preference (CPP) paradigm. Selective muscarinic receptor agonists and antagonists were both singly and combinatorically injected into the RMTg to examine their effects on the acquisition of systemic morphine-induced CPP and locomotor activity. The M3 muscarinic receptor agonist, pilocarpine, inhibited the acquisition of morphine-induced CPP, whereas its antagonist, 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide (4-DAMP, 1 μg/side), reversed the inhibitory effect of pilocarpine (30 μg/side). Additionally, 4-DAMP increased locomotor activity while pilocarpine (30 μg/side) partially decreased locomotor activity when combined with morphine. In contrast, the M4 muscarinic receptor agonist, LY2033298 (0.1 and 0.2 μg/side), and antagonist, tropicamide (20 and 40 μM/side), did not affect the acquisition of morphine-induced CPP or locomotor activity. Taken together, our findings suggest that RMTg M3 muscarinic receptors are involved in opioid-induced rewarding and psychomotor effects. Therefore, RMTg M3 muscarinic receptors may represent a promising target for the treatment of opioid addiction.

Repeated administration of morphine profoundly influences the dopaminergic and cholinergic systems in the nucleus accumbens [including the shell of the nucleus accumbens (NAcS)]. Further, dopamine release is regulated by the cholinergic system, especially the M

The non-selective muscarinic receptor agonist oxotremorine-M has been found to decrease impulsive choice in high-impulsive (HI) rats and increase impulsive choice in low-impulsive (LI) rats, but little is known about the muscarinic M

Rationale Clinical studies have shown that patients with exaggerated risk-taking tendencies have high baseline levels of norepinephrine. In this work, we systemically manipulated norepinephrine levels in rats and studied their behavioral changes in a probabilistic discounting task, which is a paradigm for gauging risk taking. Methods This study aims to explore the effects of the selective norepinephrine reuptake inhibitor (atomoxetine at doses of 0.6, 1.0 and 1.8 mg/kg), and receptor selective antagonists (propranolol at a single dose of 1.0/kg, and prazosin at a single dose of 0.1 mg/kg), on risk taking using a probabilistic discounting task. In this task, there were two levers available to rats: pressing the ‘small/certain’ lever guaranteed a single food pellet, and pressing the ‘large/risky’ lever yielded either four pellets or none. The probability of receiving four food pellets decreased across the four experimental blocks from 100% to 12.5%. Results Atomoxetine increased the tendency to choose the large/risky lever. It significantly reduced the lose-shift effect (i.e. pressing a different lever after losing a trial), but did not affect the win-stay effect (i.e. pressing the same lever after winning a trial). Furthermore, co-administration of beta-adrenoreceptor antagonist, propranolol, eliminated the effects of atomoxetine on risk taking and the lose-shift effect; but co-administration of alpha 1 -adrenoreceptor antagonist, prazosin, did not. Conclusions Atomoxetine boosted NE levels and increased risk taking. This was because atomoxetine decreased rats' sensitivity to losses. These effects were likely mediated by beta-adrenoreceptor.

In this paper, an ultra-broadband and polarization insensitive terahertz (THz) metamaterial absorber is presented and investigated. With the optimization of the structural parameters, resonant peaks are merged into a broadband absorption spectrum. The simulation results demonstrate that a wide bandwidth of 3.1 THz is obtained in the range from 2.6 to 5.7 THz, where the absorption is higher than 90% for the normal incident THz waves. The full width at half maximum (FWHM) of absorption spectrum is 95% with respect to central frequency (similar to 4 THz), which is five times greater than the FWHM of a single layer structure. Furthermore, this structure can keep the absorption above 88% over a large frequency range (>2.5 THz) when the incident angle is smaller than 50 degrees. This metamaterial absorber can find potential applications in terahertz imaging and stealth technology. Crown Copyright (C) 2015 Published by Elsevier B.V. All rights reserved.

The analysis of status and major sources of human pressures on natural reserves (NRs) is important for optimizing their management. This study selected population density, gross domestic product (GDP) density and areal percentage of human land use to reveal the human pressures of national and provincial NRs (NNRs and PNRs) in Yunnan Province, China. We calculated three types of internal and external human pressure index (HPI) and comprehensive HPI (CHPI) for NRs. Human pressures on most of NRs were slight and light, indicating that most of NRs were well protected. Human pressures on PNRs were higher than on NNRs; with respect to five types of NRs, geological relict NRs were facing the highest human pressures, followed by wetland ecosystem NRs. Land use and population density were the main human pressures on these NRs. Yunnan Province should put the highest emphasis on three NNRs and two Ramsar site PNRs with severe CHPI, secondly pay attention to eight conservation-oriented PNRs with extreme or severe CHPI. It’s urgent for Yunnan to implement scientific policies and measures to reduce land use and population density pressures of NRs, especially with severe and extreme CHPI, by transforming internal land use and/or implementing residents’ eco-migration.

Both drug-related cues and drug priming are the main factors that induce relapse of drug addiction. Previous research has reported that blockade of the muscarinic receptors could significantly depress addictive behavior, suggesting that the muscarinic receptors might be involved in drug use and relapse behavior. The nucleus accumbens (NAc), especially the shell of the NAc, where the muscarinic receptors are expressed, is critical for craving and relapse. This study investigated the effects of microinfusion of the muscarinic receptor antagonist scopolamine into the NAc shell on context- and morphine-induced expression of behavioral sensitization. Behavioral sensitization was established by exposure to 5mg/kg morphine once daily for five consecutive days. Expression of behavioral sensitization was induced by saline challenge or 5mg/kg morphine challenge. The results showed that: (a) the muscarinic receptor antagonist scopolamine (10.8μg/rat) microinjected into the NAc shell blocked expression of conditional sensitization; (b) acetylcholinesterase inhibitor huperzine-A (0.5 and 0.1μg/rat), but not scopolamine (10.8μg/rat), microinjected into the NAc shell blocked morphine-induced expression of sensitization; and (c) pre-infusion of scopolamine (10.8μg/rat) reversed the inhibitory effect of huperzine-A (0.5μg/rat) on morphine-induced sensitization. Our findings suggest that muscarinic receptors in the NAc shell play different roles in context-induced and morphine-challenged expression of behavioral sensitization.

This study investigated the relationships among an enriched environment, stress levels, and drug addiction. Mice were divided randomly into four treatment groups (n=12 each): enriched environment without restraint stress (EN), standard environment without restraint stress (SN), enriched environment with restraint stress (ES), and standard environment with restraint stress (SS). Mice were reared in the respective environment for 45 days. Then, the ES and SS groups were subjected to restraint stress daily (2 h/day) for 14 days, whereas the EN and SN groups were not subjected to restraint stress during this stage. The stress levels of all mice were tested in the elevated plus maze immediately after exposure to restraint stress. After the 2-week stress testing period, mice were administered acute or chronic morphine (5 mg/kg) treatment for 7 days. Then, after a 7-day withdrawal period, the mice were injected with saline (1 ml/kg) or morphine (5 mg/kg) daily for 2 days to observe locomotor activity. The results indicated that the enriched environment reduced the stress and locomotor activity induced by acute morphine administration or saline after chronic morphine treatment. However, the enriched environment did not significantly inhibit locomotor activity induced by morphine challenge. In addition, the stress level did not mediate the effect of the enriched environment on drug-induced locomotor activity after acute or chronic morphine treatment.

In China there are large amounts of coal located underneath buildings. In this article the severity of the problem is studied, and the characteristics of the mining technology used for the extraction of coals under buildings are described. Based on the comprehensive analyses of the abundant literature, separated bed grouting, backfill mining, Partial Mining and homonic mining technology, are the main mining technologies that exist for extraction of these coals. At the same time, the necessary measures for protecting the buildings are also considered. In particular, the authors have analysed the development of these mining technologies and concluded that the waste filling will be the focus of development, and that the main developing technologies of the filling mining method should be further perfecting the separated bed filling, strip mining and strenthening the anti-deformation of building.

Repetitive exposure to opioids elicits sensitization to its psychomotor stimulating effect and environmental stimuli contribute to this effect. This study first developed a procedure that simultaneously measures conditioned hyperactivity and locomotor sensitization, and then investigated the effects of physostigmine on the development and expression of conditioned hyperactivity and locomotor sensitization in rats. Five groups of rats (10-12 rats each) were conditioned with a conditioned stimulus (CS) for 20 min and then drug or saline paired with CS for 2 h daily for 10 days. Rats were tested 20 min on day 18. On day 25, rats were tested 20 min and subsequently 2 h (immediately after morphine injection). Although the 20 min locomotion was not different among the rats on day 1, rats that received 5 mg/kg morphine during conditioning showed higher locomotion than those received saline or 5 mg/kg morphine in the home cage on day 18 and day 25. Rats received 0.1 mg/kg physostigmine and 5 mg/kg morphine during conditioning showed higher locomotion than those received 5 mg/kg morphine on day 18. On day 25, 0.1 mg/kg physostigmine attenuated the conditioned hyperactivity and expression of morphine locomotor sensitization. In contrast, rats received 0.1 mg/kg physostigmine and 5 mg/kg morphine during conditioning showed higher locomotion during 2 h test period than those received 5 mg/kg morphine. In conclusion, this study established a procedure that simultaneously study conditioned hyperactivity and locomotor sensitization. Physostigmine attenuates the expressions but enhances the development of conditioned hyperactivity and sensitization and the possible mechanisms are discussed.

The effect of acetylcholine on impulsive choice is thought to be due to interactions between cholinergic and dopaminergic systems, but this hypothesis has not been proven. This study investigated whether D1-like receptors were involved in the effects of the muscarinic cholinergic agonist oxotremorine on impulsive choice in high-impulsive rats (HI rats, n=8) and low-impulsive rats (LI rats, n=8) characterized by basal levels of impulsive choice in a delay-discounting task. The results revealed that oxotremorine (0.05mg/kg) significantly increased the choice of the large reinforcer in HI rats, whereas decreased the choice of the large reinforcer in LI rats. The D1-like antagonist SCH 23390 produced significant reductions in the large-reinforcer choice in HI rats (0.01mg/kg) and LI rats (0.005, 0.0075, and 0.01mg/kg). SCH 23390 significantly inhibited the increase in the choice of the large reinforcer induced by oxotremorine (0.05mg/kg) in HI rats at doses of 0.005 and 0.0075mg/kg, but enhanced the effect of oxotremorine in LI rats only at the dose of 0.0075mg/kg. These findings suggested that D1-like receptors might be involved in the differential effects of oxotremorine on impulsive choice between HI rats and LI rats.