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Autonomous underwater vehicles (AUVs) have a limited bandwidth for real-time communication, limiting rapid responses to unexpected obstacles. This study addressed how AUVs can navigate to a target without a pre-existing obstacle map by generating one in real-time and avoiding obstacles. This paper proposes using forward-looking sonar with an occupancy grid map (OGM) for real-time obstacle mapping and a potential field algorithm for avoiding obstacles. The OGM segments the map into grids, updating the obstacle probability of each cell for precise, quick mapping. The potential field algorithm attracts the AUV towards the target and uses repulsive forces from obstacles for path planning, enhancing computational efficiency in a dynamic environment. Experiments were conducted in coastal waters with obstacles to verify the real-time obstacle mapping and avoidance algorithm. Despite the high noise in sonar data, the experimental results confirmed effective obstacle mapping and avoidance. The OGM-based potential field algorithm was computationally efficient, suitable for single-board computers, and demonstrated proper parameter adjustments through two distinct scenarios. The experiments also identified some of challenges, such as dynamic changes in detection rates, propulsion bubbles, and changes in repulsive forces caused by sudden obstacles. An enhanced algorithm to address these issues is currently under development.

Abstract The conversion of CO2 into fuels and valuable chemicals presents a viable path toward carbon neutrality. The aim of this study is to investigate the potential of metal-doped graphene catalysts in the reduction of CO2 to C1 products. 20 typical M-graphene (M = metal) catalysts were established based on DFT calculations. Six candidate catalysts, i.e., V-, Cr-, Mn-, Ni-, Mo-, and Ta-graphene catalysts, were selected by combining the hydrogen dissociation ability and the energy band gap of the catalysts. Subsequently, the adsorption characteristics and hydrogenation reactions of CO2 over the six candidates were explored. CO2 tends to adsorb at the M site through vertical adsorption and carbon–oxygen co-adsorption. V- and Cr-graphene catalysts promote the production of intermediate COOH, whereas Mn-, Ni-, Mo-, and Ta-doped surfaces are more favorable for HCOO formation. Concerning the hydrogenation to CO and HCOOH, V-, Cr-, Ni- and Mo-graphene catalysts preferentially yield CO from COOH, whereas Ta-doped graphene favors the formation of HCOOH. In total, the competitive hydrogenation of CO2 reveals the selectivity of the C1 products. Cr- and Ni-graphene favor the production of HCOOH and CH3OH, whereas V-, Mn-, Mo-, and Ta-graphene primarily yield CH3OH. Graphical Abstract

In this paper, we present a full coverage path planning (CPP) algorithm for the marine surveys conducted in the convex polygon shaped search area. The survey is supposed to carry out by torpedo-type AUVs (autonomous underwater vehicles). Due to their nonholonomic mechanical characteristics, these vehicles have nonzero minimum turning radius. For any given polygon shaped search area, it can always be partitioned into one or more convex polygons. With this in mind, this paper proposes a novel search algorithm called CbSPSA (Calculation based Shortest Path Search Algorithm) for full coverage of any given convex polygon shaped search area. By aligning the search inter-tracks alongside the edge with the minimum height, we can guarantee the minimum number of the vehicle’s turns. In addition, the proposed method can guarantee the planned path is strictly located inside the polygon area without overlapped or crossed path lines, and also has the total path length as short as possible. Considering the vehicle’s nonzero minimum turning radius, we also propose a sort of smoothing algorithm which can smooth the waypoint path searched by CbSPSA so that the vehicle can exactly follow it. The smoothed path is also guaranteed to be strictly located inside the polygon. Numerical simulation analyses are also carried out to verify the effectiveness of the proposed schemes.

Gastrochilus is an orchid genus containing about 70 species in tropical and subtropical Asia with high morphological diversity. The phylogenetic relationships among this genus have not been fully resolved, and the plastome evolution has not been investigated either. In this study, five plastomes of Gastrochilus were newly reported, and sixteen plastomes of Gastrochilus were used to conduct comparative and phylogenetic analyses. Our results showed that the Gastrochilus plastomes ranged from 146,183 to 148,666 bp, with a GC content of 36.7–36.9%. There were 120 genes annotated, consisting of 74 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. No contraction and expansion of IR borders, gene rearrangements, or inversions were detected. Additionally, the repeat sequences and codon usage bias of Gastrochilus plastomes were highly conserved. Twenty hypervariable regions were selected as potential DNA barcodes. The phylogenetic relationships within Gastrochilus were well resolved based on the whole plastome, especially among main clades. Furthermore, both molecular and morphological data strongly supported Haraella retrocalla as a member of Gastrochilus (G. retrocallus).

This paper considers the coverage path planning (CPP) problem for marine surveys, where the survey vehicles’ movements are confined in the irregular polygon search area. So this is a sort of milling problem with the minimum number of turns in order for improvement of the acquired sonar image quality. For this purpose, this paper proposes a novel method called CbSPSA (calculation based shortest path search algorithm). Especially in the irregular corner area, this algorithm can easily calculate a kind of shortest path for its full coverage of this irregular area. For any given polygon, it can always be partitioned into convex polygon(s). In this paper, we only consider the case where these divided convex polygons are all connected one by one. In this case, the shortest path with minimum turns in each convex polygon can be easily searched by CbSPSA. And further by simply linking all of these pieces, the total coverage path for any given polygon area can be constructed. On the other hand, for a given polygon, usually there are several different cases of partition. Among the searched coverage paths for each of these different partitions, the final optimal coverage path is determined through a predefined criteria. Numerical simulation and analyses are carried out to demonstrate the effectiveness of the proposed method.

This study presents a mission management technique that is a key component of underwater docking system used to expand the operating range of autonomous underwater vehicle (AUV). We analyzed the docking scenario and AUV operating environment, defining the feasible initial area (FIA) level, event level, and global path (GP) command to improve the rate of docking success and AUV safety. Non-holonomic constraints, mounted sensor characteristic, AUV and mission state, and AUV behavior were considered. Using AUV and docking station, we conducted experiments on land and at sea. The first test was conducted on land to prevent loss and damage of the AUV and verify stability and interconnection with other algorithms; it performed well in normal and abnormal situations. Subsequently, we attempted to dock under the sea and verified its performance; it also worked well in a sea environment. In this study, we presented the mission management technique and showed its performance. We demonstrated AUV docking with this algorithm and verified that the rate of docking success was higher compared to those obtained in other studies.

AIM: To investigate the current quality of life in children with amblyopia and its influencing factors.METHODS: Cross-sectional study. Using random sampling method, 178 children with amblyopia were selected as the research objects, and the Chinese version of the Universal Core Scale of Children's Quality of Life was used to investigate the research objects. The impact of amblyopia on children's quality of life was analyzed. RESULTS:The quality of life score of children with amblyopia was(77.23±15.52)points. The results of multiple linear regression showed that parental education, left eye best-corrected visual acuity, right eye corrected visual acuity, coverage, premature delivery, hypoxia at birth and delivery way were the main factors affecting the quality of life of amblyopic children. It can explain 38.6% of the variance in the quality of life of children with amblyopia(F=15.242, P

Grain sorghum has been a significant contributor to global food security since the prehistoric period and may contribute even more to the security of both food and energy in the future. Globally, precise management techniques are crucial for increasing grain sorghum productivity. In China, with diverse ecological types, variety introduction occasionally occurs across ecological zones. However, few information is available on the effect of ecological type on genotype performance and how plant spacing configuration influences grain yield in various ecological zones. Hence, a series of two-year field experiments were conducted in 2020 and 2021 in four ecological zones of China, from the northeast to the southwest. The experiments included six widely adapted sorghum varieties under six plant spacing configurations (two row spacing modes: equidistant row spacing (60 cm) mode and wide (80 cm)-narrow (40 cm) row spacing mode; three in-row plant spacings: 10 cm, 15 cm, and 20 cm). Our results indicated that ecological type, variety, and plant spacing configuration had a significant effect on sorghum yield. Ecological type contributed the highest proportion to the yield variance (49.8%), followed by variety (8.3%), while plant spacing configuration contributed 1.8%. Sorghum growth duration was highly influenced by the ecological type, accounting for 87.2% of its total variance, whereas plant height was mainly affected by genotype, which contributed 81.6% of the total variance. All test varieties, developed in the south or north, can reach maturity within 94-108 d, just before fall sowing in central China. Generally, sorghum growth duration becomes longer when a variety is introduced from south to north. A late-maturing variety, developed in the spring sowing and late-maturing regions, possibly could not reach maturity in the early-maturing region. The row spacing modes had no significant affect on sorghum yield, but the equal-row spacing mode consistently caused higher yields with only one exception; this might imply that equal-row spacing mode was more advantageous for boosting sorghum yield potential. In contrast, decreasing in-row plant spacing showed significant positive linear associations with sorghum grain yield in most cases. In addition, these results demonstrated that sorghum is a widely adapted crop and enables success in variety introduction across ecological zones.

This paper proposes an optimal design method for an unmanned underwater vehicle (UUV) platform to overcome strong current. First, to minimize the hydrodynamic drag components in water, the vehicle is designed to have a streamlined disc shape, which help maintaining horizontal motion (zero roll and pitch angles posture) while overcoming external current. To this end, four vertical thrusters are symmetrically mounted outside of the platform to stabilize the vehicle’s horizontal motion. In the horizontal plane, four horizontal thrusters are symmetrically mounted outside of the disc, and each of them has the same forward and reverse thrust performances. With these four thrusters, a specific thrust vector control (TVC) method is proposed, and for external current in any direction, four horizontal thrusters are controlled to generate a vectored thrust force to encounter the current while minimizing the vehicle’s rotation and maintaining its heading. However, for the numerical simulations, the vehicle’s hydrodynamic coefficients related to the horizontal plane are derived based on both theoretical and empirically derived formulas. In addition to the simulation, experimental studies in both the water tank and circulating water channel are performed to verify the vehicle’s various final performances, including its ability to overcome strong current.

Sorghum [Sorghum bicolor (L.) Moench] is an important crop for food security in semiarid and arid regions due to its high tolerance to abiotic and biotic stresses and its good performance in marginal lands with relatively low fertility. To deeply understand the interrelationship among sorghum genotype, environment, sowing dates, and densities in the spring sowing early maturing (SSEM) areas of China, and to provide a basis for specifying scientific and reasonable cultural practices, a two-year field experiment was conducted with six popular varieties at six locations. Combined ANOVA showed that the yield difference between years was significant (P

In this paper, we propose a trajectory tracking controller with experimental verification for torpedo-like autonomous underwater vehicles (AUVs) with underactuation characteristics. The proposed controller overcomes the underactuation problem by designing the desired error dynamics in a coupled form using state variables in body-fixed and world coordinates. Unlike the back-stepping control requiring high-order derivatives of state variables, the proposed controller only requires the first derivatives of the states, which can alleviate noise magnification issues due to differentiation. We adopt time delay estimation to estimate the dynamics indirectly using control inputs and vehicle outputs, making the proposed controller relatively easy to apply without requiring the all of the vehicle dynamics. We also address some practical issues that commonly arise in experimental environments: handling measurement noises and actuation limits. To mitigate the effects of noise on the controller, a filtering technique using a moving window average is employed. Additionally, to account for the actuation limits, we design an anti-windup structure that takes into consideration the nonlinearity between the thrusting force and rotating speed of the thruster. We verify the tracking performance of the proposed controller through experimentation using an AUV. The experimental results show that the 3D motion control of the proposed controller exhibits an RMS error of 0.3216 m and demonstrate that the proposed controller achieves accurate tracking performance, making it suitable for survey missions that require tracking errors of less than one meter.

We developed a heavy-duty work class ROV trencher named URI-T (Underwater robot it’s trencher) that can conduct burial and maintenance tasks for underwater cables and small diameter pipelines. It requires various supporting systems, including a dynamic positioning (DP) vessel, launch and recovery system (LARS), A-frame, and winch in order to perform burial tasks because of its dimensions (6.5 m × 5.0 m × 4.5 m, 20 t) and the tough working environment. However, operating a DP vessel has disadvantages as it is expensive to rent and operate and it is difficult to adjust the working schedule for some domestic coast construction cases. In this paper, we propose a method using a barge instead of a DP vessel to avoid the above disadvantages. Although burying the cable and pipeline using a barge has lower working efficiency than a DP vessel, it can save construction expenses and does not require a large crew. The proposed method was applied over two months at the construction of the water supply in Yokji-do, and the results were verified.

Abstract Background Gene flow in plants via pollen and seeds is asymmetrical at different geographic scales. Orchid seeds are adapted to long-distance wind dispersal but pollinium transfer is often influenced by pollinator behavior. We combined field studies with an analysis of genetic diversity among 155 physically mapped adults and 1105 F1 seedlings to evaluate the relative contribution of pollen and seed dispersal to overall gene flow among three sub-populations of the food-deceptive orchid Phalaenopsis pulcherrima on Hainan Island, China. Results Phalaenopsis pulcherrima is self-sterile and predominantly outcrossing, resulting in high population-level genetic diversity, but plants are clumped and exhibit fine-scale genetic structuring. Even so, we detected low differentiation among sub-populations, with polynomial regression analysis suggesting gene flow via seed to be more restricted than that via pollen. Paternity analysis confirmed capsules of P. pulcherrima to each be sired by a single pollen donor, probably in part facilitated by post-pollination stigma obfuscation, with a mean pollen flow distance of 272.7 m. Despite limited sampling, we detected no loss of genetic diversity from one generation to the next. Conclusions Outcrossing mediated by deceptive pollination and self-sterility promote high genetic diversity in P. pulcherrima. Long-range pollinia transfer ensures connectivity among sub-populations, offsetting the risk of genetic erosion at local scales.

In this paper, we present a 3D formation control scheme for a group of torpedo-type underactuated autonomous underwater vehicles (AUVs). These multiple AUVs combined with an unmanned surface vessel (USV) construct a sort of star-topology acoustic communication network where the USV is at the center point. Due to this kind of topological feature, this paper applies a virtual school concept. This is a geometric graph where each node is taken as a virtual leader for each specific AUV and assigned its own reference trajectory. For each individual vehicle, its formation strategy is simple: just follow the trajectory of its corresponding virtual leader so as for multiple AUVs to compose the given formation. As for the formation subject, this paper mainly focuses on the formation tracking problem rather than the formation producing. For the torpedo-type vehicle considered in this paper, there are only three control inputs (surge force, pitch, and yaw moments) available for its underwater 3D motion and therefore this is a typical underactuated system. For the following vehicle’s trajectory, a sort of potential field method is used for obstacle avoidance, and a neural network-based adaptive scheme is applied to on-line approximate the vehicle’s unknown nonlinear dynamics, and the uncertainty terms including modeling errors, measurement noises, and external disturbances are handled by the properly designed robust scheme. The proposed formation method can guarantee the uniform ultimate boundedness (UUB) of the closed-loop system. Numerical studies are also carried out to verify the effectiveness of the proposed scheme.

Starch is the most important component in endosperm of sorghum grain. Usually, two types of starch are present: amylose (AM) and amylopectin (AP). The levels of AM and AP contents play a significant role in the appearance, structure, and quality of sorghum grains and in marketing applications. In the present study, a panel of 634 sorghum (Sorghum bicolor (L.) Moench) accessions were evaluated for starch, AM, and AP contents of grain, which included a mini core collection of 242 accessions from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in India, and 252 landraces and 140 cultivars from China. The average starch content was 67.64% and the average AM and AP contents were 20.19 and 79.81%, respectively. We developed a total of 260 000 high-confidence single nucleotide polymorphism (SNP) markers in the panel of 634 accessions of S. bicolor using specific locus amplified fragment sequencing (SLAF-seq). We performed genome-wide association studies (GWAS) of starch, AM, and AM/AP of grain and SNP markers based on a mixed linear model (MLM). In total, 70 significant association signals were detected for starch, AM, and AM/AP ratio of grain with P

This paper presents the autonomous swimming technology developed for an Autonomous Underwater Vehicle (AUV) operating in the underwater jacket structure environment. To prevent the position divergence of the inertial navigation system constructed for the primary navigation solution for the vehicle, we've developed kinds of marker-recognition based underwater localization methods using both of optical and acoustic cameras. However, these two methods all require the artificial markers to be located near to the cameras mounted on the vehicle. Therefore, in the case of the vehicle far away from the structure where the markers are usually mounted on, we may need alternative position-aiding solution to guarantee the navigation accuracy. For this purpose, we develop a sonar image processing based underwater localization method using a Forward Looking Sonar (FLS) mounted in front of the vehicle. The primary purpose of this FLS is to detect the obstacles in front of the vehicle. According to the detected obstacle(s), we apply an Occupancy Grid Map (OGM) based path planning algorithm to derive an obstacle collision-free reference path. Experimental studies are carried out in the water tank and also in the Pohang Yeongilman port sea environment to demonstrate the effectiveness of the proposed autonomous swimming technology. Keywords: Autonomous Underwater Vehicle (AUV), Autonomous navigation, Underwater localization, Occupancy Grid Map (OGM), Obstacle detection, Path planning

An ROV trencher is a type of heavy-duty work class ROV equipped with high-pressure water jet tools for cutting into the sea floor and burying cables. This kind of trencher is mostly used for PLIB operations. This paper introduces the development of this kind of ROV trencher, which has a 698 kW power system, with a 250 kW hydraulic system and two 224 kW water jet systems. The project was launched in January 2014. After four years of design, manufacturing, and system integration, we carried out two sea trials near the Yeongilman port (about 20–30 m in depth) in Pohang to evaluate the system performance in November 2017 and August 2018. Through tests, we found that most of specifications were satisfied, including a maximum bury depth of 3 m, maximum bury speed of 2 km/h, and maximum forward speed of 1.54 m/s.

When burying underwater cables using robots, heading control is one of the key functions for the robots to improve task efficiency. This paper addresses the heading control issue for URI-T, an ROV for underwater construction tasks, including the burial and maintenance of cables or small diameter pipelines. Through modeling and identifying the heading motion of URI-T, the dynamic characteristics and input limitation are analyzed. Based on the identification results, a PD type controller with appropriate input treatment is designed for the heading control of URI-T. The performance of the heading controller was verified in water tank experiments. The field applicability of the proposed controller was also evaluated through the sea trial of URI-T at the East Sea, with a water depth of 500 m.

Robust and accurate estimation of position and attitude of a UUV (Unmanned Underwater Vehicle) from sonar scans is essential for simultaneous localization and mapping (SLAM). Both dead-reckoning based on the inertial navigation system and the motion parameter estimation based on the registration of the ultrasound scan sequence can contribute to the performance of the system. However, the rapidly-growing accumulated error tends to counteract the precise localization of the vehicle. In this paper, a method for loop-closure detection is proposed that adjusts the accumulated error for the underwater acoustic SLAM when the vehicle scans the underwater environment using an Mechanical Scanning Imaging Sonar (MSIS). Firstly, a similarity matrix for pairs of scans is constructed to represent the loop-closing tracks. In the registration step, two novel features, namely the intensity projection histograms and a polar gradient matrix, are extracted to calculate the translational and rotational parameters respectively. Secondly, the probability hypothesis density (PHD) filter is used to extract the possible loop-closure constraints from the similarity matrix, removing the random noise brought by accidental correlation and refining the concurrent loop-closing tracks resulted from long-range scanning. Lastly, the loop-closure constraints from the refined loop-closing tracks are fed into the GraphSLAM system to adjust the pose of each scan by constraint optimization. Experiments on the MSIS sonar images collected in structured and unstructured underwater environments validate the effectiveness of the proposed loop-closure detection method.

We aimed to construct a highly efficient, lentivirus-mediated vector for RNA interference (RNAi) silencing of the Id1 gene and to examine whether silencing of this gene promotes the neural differentiation of mesenchymal stem cells (MSCs). Three short hairpin RNA sequences targeting the coding region of the Id1 gene and one negative control (NC) sequence were designed. After monophosphorylation, these sequences were introduced into lentiviral vectors containing enhanced green fluorescent protein (EGFP) using the restriction enzyme BsmBI to construct the recombinant vectors pWSLV-EGF-shId1 (1-3) and pWSLV-EGF-NC. These recombinant lentivirus vectors were transfected into H9C2 cells to assess the silencing effect of the shId1 (1-3) sequences on the Id1 gene. Subsequently, pWSLV-EGF-NC and pWSLV-EGF-shId1 which exhibited the strongest silencing effect were transfected into the packaging cell line 293 FT. After determining the viral titers, the cultured MSCs were infected with the lentivirus (multiplicity of infection, MOI = 10). Real-time polymerase chain reaction (PCR) and Western blotting were used to examine the amounts of Id1 mRNA and protein, respectively, in the transfected MSCs, and the results revealed that Id1 expression was markedly inhibited. Finally, MSCs were treated with the growth factors EGF and bFGF in conjunction with ligustrazine to induce their differentiation into neuron-like cells. The expression of NSE/MAP-2/Nestin was detected using immunocytochemistry and real-time PCR, which revealed that the rate of neural differentiation in the pWSLV-EGF-shId1 group was higher than that of the other groups, as was NSE/MAP-2 expression. Thus, Id1 gene silencing promotes the neural differentiation of MSCs.

In underwater environments restricted from human access, many intervention tasks are performed by using robotic systems like underwater manipulators. Commonly, the robotic systems are tele-operated from operating ships; the operation is apt to be inefficient because of restricted underwater information and complex operation methods. In this paper, an assistance technique for tele-manipulation is investigated and evaluated experimentally. The key idea behind the assistance technique is to operate the manipulator by touching several points on the camera images. To implement the idea, the position estimation technique utilizing the touch inputs is investigated. The assistance technique is simple but significantly helpful to increase temporal efficiency of tele-manipulation for underwater tasks. Using URI-T, a cable burying ROV (Remotely Operated Vehicle) developed in Korea, the performance of the proposed assistance technique is verified. The underwater cable gripping task, one of the cable maintenance tasks carried out by the cable burying ROV, is employed for the performance evaluation, and the experimental results are analyzed statistically. The results show that the assistance technique can improve the efficiency of the tele-manipulation considerably in comparison with the conventional tele-operation method.

ROV trencher is a kind of ROV which trenches the sea floor using a specifically designed tool and buries the subsea cables and pipelines. According to the soil conditions, this trenching method can have two different types, one is mechanical cutting and the other one is water jetting. In this paper, we present a water jet tool design method for a 2500 m depth-rated ROV trencher. A series of CFD simulations and laboratory tests with one nozzle, and a ground test using 1:6 scale jetting arm model were carried out to derive and demonstrate the jetting tool design parameters. In October 2018, the constructed ROV trencher was put into the sea trial in the East Sea of Korea to evaluate its final performances. In addition, in December 2019, the trencher was applied in a construction site to bury subsea water pipelines near the Yogji Island in the Korea. Through these two field tests and operation, the trencher was demonstrated for both its operational capability and trenching performance. The main contribution of this paper is that it presents the entire design procedures of water jet tools, including CFD simulations, laboratory tests, field test with 1:6 scaled jetting tool, and the final prototype tool design. These consecutive procedures are carried out in order for us to set up sort of relationship between jetting angle, trench depth, trench speed, and jetting power, from which we can predict and evaluate the trenching performance of the prototype jetting tool.

This paper presents the development of an unmanned underwater vehicle (UUV) platform, especially the derivation of the vehicle’s simulation model and its control method to overcome strong sea current. The platform is designed to have a flattened ellipsoidal exterior so as to minimize the hydrodynamic damping on the horizontal plane. Four horizontal thrusters with the identical specifications are symmetrically mounted on the horizontal plane, and each of them has the same thrust dynamics in both forward and reverse directions. In addition, there are three vertical thrusters used to handle the vehicle’s roll, pitch and heave motions. Control strategy proposed in this paper to overcome strong current is that: maximizing the vectored horizontal thrust force against the sea current without or with the least of the vehicle’s rotation on the horizontal plane. For the vehicle model, due to it being symmetric in all of three axes, the vehicle dynamics can be simplified and all of hydrodynamic coefficients are calculated through both of theoretical and empirically-derived formulas. Numerical simulations and experimental studies in both of the water tank and the circulating water channel are carried out to demonstrate the vehicle’s capability of overcoming strong current.

Oxidative stress and inflammation are hypothesized to contribute to the pathogenesis of chronic obstructive pulmonary disease (COPD). Resveratrol (trans-3,5,4′-trihydroxystilbene) is known for its antioxidant and anti-inflammatory properties. The study aimed to investigate the effects of resveratrol in a rat model with COPD on the regulation of oxidative stress and inflammation via the activation of Sirtuin1 (SIRTl) and proliferator-activated receptor-γ coactivator-1α (PGC-1α). Thirty Wistar rats were randomly divided into three groups: control group, COPD group and resveratrol intervention group. The COPD model was established by instilling with lipopolysaccharide (LPS) and challenging with cigarette smoke (CS). The levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) in serum were measured. The levels of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) were measured. The expression levels of SIRT1 and PGC-1α in the lung tissues were examined by immunohistochemistry as well as real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR) and western blotting analysis. After the treatment with resveratrol (50 mg/kg), compared with the COPD group, alleviation of inflammation and reconstruction in the small airways of the lungs were seen. Resveratrol might be correlated not only with the lower level of MDA and the higher activity of SOD, but also with the upregulation of SIRT1 and PGC-1α expression. Resveratrol treatment decreased serum levels of IL-6 and IL-8. Our findings indicate that resveratrol had a therapeutic effect in our rat COPD model, which is related to the inhibition of oxidative stress and inflammatory response. The mechanism may be related to the activation and upgrading of the SIRT1/PGC-1α signaling pathways. Thus resveratrol might be a therapeutic modality in COPD.

Abstract NMDA receptor-dependent long-term depression (LTD) in the hippocampus is a well-known form of synaptic plasticity that has been linked to different cognitive functions. Although the underlying mechanisms remain unclear, this form of LTD cannot be induced by low-frequency stimulation (LFS) in adult mice. In this study, we found that LFS-induced LTD was not easily induced in adult animals and was age dependent. Interestingly, the level of the 5-HT1A receptor was correspondingly increased and exhibited an inverse correlation with the magnitude of LFS-LTD during development. Knockout or pharmacological inhibition of the 5-HT1A receptor reversed impaired LFS-LTD in adult mice (P60), while activation or inhibition of this receptor disturbed or enhanced LFS-LTD in adolescent mice (P21), respectively. Furthermore, the astrocytic 5-HT1A receptor in the hippocampus predominantly mediated age-dependent LFS-LTD through enhancing GABAergic neurotransmission. Finally, fear memory extinction differed among the above conditions. These observations enrich our knowledge of LTD at the cellular level and suggest a therapeutic approach for LTD-related psychiatric disorders.

Abstract Background Ichang papeda (Citrus ichangensis), a wild perennial plant of the Rutaceae family, is a cold-hardy plant. WRKY transcription factors are crucial regulators of plant growth and development as well as abiotic stress responses. However, the WRKY genes in C. ichangensis (CiWRKY) and their expression patterns under cold stress have not been thoroughly investigated, hindering our understanding of their role in cold tolerance. Results In this study, a total of 52 CiWRKY genes identified in the genome of C. ichangensis were classified into three main groups and five subgroups based on phylogenetic analysis. Comprehensive analyses of motif features, conserved domains, and gene structures were performed. Segmental duplication plays a significant role in the CiWRKY gene family expansion. Cis-acting element analysis revealed the presence of various stress-responsive elements in the promoters of the majority of CiWRKYs. Gene ontology (GO) analysis and protein-protein interaction predictions indicate that the CiWRKYs exhibit crucial roles in regulation of both development and stress response. Expression profiling analysis demonstrates that 14 CiWRKYs were substantially induced under cold stress. Virus-induced gene silencing (VIGS) assay confirmed that CiWRKY31, one of the cold-induced WRKYs, functions positively in regulation of cold tolerance. Conclusion Sequence and protein properties of CiWRKYs were systematically analyzed. Among the 52 CiWRKY genes 14 members exhibited cold-responsive expression patterns, and CiWRKY31 was verified to be a positive regulator of cold tolerance. These findings pave way for future investigations to understand the molecular functions of CiWRKYs in cold tolerance and contribute to unravelling WRKYs that may be used for engineering cold tolerance in citrus.