Search

First, to develop a reasonable carbon sequestration model to predict the amount of carbon dioxide sequestered by forests and their products, we constructed an EPIC-based carbon sequestration model to simulate the amount of carbon dioxide sequestered and the actual amount of carbon dioxide sequestered. forest management strategies and find the best strategies. In addition, a meta-analysis-based optimal forest resource utilization model was established, which comprehensively analyzed forests, including carbon dioxide sequestration and other natural, social and economic values.

Human induced neural stem/progenitor cells (iNPCs) are a promising source of cells for stem cell-based therapy. The therapeutic potential of human iNPCs has been extensively tested in animal models, including both mouse and monkey models. However, the comprehensive characterization of grafted iNPCs in the brain of non-human primates has been lagged behind. In this study, we transplanted human iNPCs into the basal forebrain of adult cynomolgus monkeys. We found that grafted iNPCs predominantly differentiated into neurons that displayed long-term survival up to 12 months. Additionally, iNPC-derived human neurons gradually matured in term of morphology and subtype differentiation. More excitingly, we observed that human neurons displayed electrophysiological activities resembling those of mature neurons, indicating the acquisition of functional membrane properties. Collectively, this study systematically characterized human iNPCs in the brain of non-human primates, and will provide invaluable clues for developing safe and effective stem cell-based therapies for different brain disorders.

Type VI secretion systems (T6SS) are specific antibacterial weapons employed by diverse bacteria to protect themselves from competitors. Pseudomonas putida KT2440 possesses a functional T6SS (K1-T6SS) and exhibits antibacterial activity towards a broad range of bacteria. Here we found that the Wsp signal transduction system regulated K1-T6SS expression via synthesizing the second messenger cyclic di-GMP (c-di-GMP), thus mediating antibacterial activity in P. putida. High-level c-di-GMP produced by Wsp system repressed the transcription of K1-T6SS genes in structural operon and vgrG1 operon. Transcriptional regulator FleQ and ATPase FleN functioned as repressors in the Wsp system-modulated K1-T6SS transcription. However, FleQ and FleN functioned as activators in biofilm formation, and Wsp system promoted biofilm formation largely in a FleQ/FleN-dependent manner. Furthermore, FleQ-FleN complex bound directly to the promoter of K1-T6SS structural operon in vitro, and c-di-GMP promoted the binding. Besides, P. putida biofilm cells showed higher c-di-GMP levels and lower antibacterial activity than planktonic cells. Overall, our findings reveal a mechanism by which Wsp system oppositely modulates antibacterial activity and biofilm formation via FleQ-FleN, and demonstrate the relationship between plankton/biofilm lifestyles and antibacterial activity in P. putida.

The 5-fluorouracil (5-FU) was a classical chemotherapy drug. The administrational carrier of nano-particle provides enhancement effect prior to target and reduce side effect. But the specific function of nano-particle on the peritoneal metastasis of breast cancer was poorly understood. Our study was designed to discover the biological function of anti-tumor nano-particle with new type 5-FU on breast cancer. The nano-particle of 5-fluorouracil (5-FU-NPs) was prepared by multiple emulsion method. The distribution of particle size was analyzed by electron microscope. The proliferation and apoptosis of cell in breast cancer was interfered by 5-FU solution (control group) or 5-FU-NPs. Cell cycle was assessed by flow cytometry and proliferation was detected by MTT and cell clone technology. The rat was injected with 5-FU solution (control group) or 5-FU-NPs intraperitoneally followed by analysis of tumor volume and size. The average tumor diameter was 200±10.84 nm. The encapsulation rate and loading rate was 81.6±5.7% and 7.29±0.14% respectively. The apoptosis of MCF-7 cell treated by 5-FU-NPs was increased significantly with abundant rounded and floating apoptotic cellular morphology as well as reduced quantity of surviving cells. The number of bacterial colony induced by 5-FU-NPs, which could interdict cell cycle. The 5-FU-NPs could restrain tumor cell growth in peritoneal metastasis of breast cancer. The new-type nano-particle of 5-FU loaded with PEG-PLGA could retard breast cancer cell proliferation and peritoneal metastasis of breast cancer in rats.

Sleep disorders have been observed among patients with heart failure. The aim of this study was to investigate whether acute sleep deprivation (SD) aggravates left heart function. Male C57B/L6 mice were assigned to four experimental groups. Ligation of the left anterior descending branch (LAD) caused myocardial infarction (MI) in mice in the LAD group and the LAD+SD group, while mice in the sham and sham+SD groups underwent the same surgery without ligation. Echocardiography was performed before and 8 weeks after ligation of the LAD to evaluate the left ventricular internal diameter at diastole (LVIDd), left ventricular internal diameter at systole (LVIDs), ejection fraction (EF), and fractional shortening (FS). Seven days of sleep deprivation induced using the modified single platform method resulted in a lower EF and FS and a higher LVIDd and LVIDs, as well as increased expression of the IL-1β, IL-18, and IL-10 mRNAs in the left ventricular tissue of MI mice. ELISA also indicated higher levels of IL-1β and IL-10 in the LAD+SD group. It was concluded that acute sleep deprivation induced cardiovascular alterations in cardiac structure and function in HF mice, accompanied by increased levels of inflammatory cytokines.

Two-component systems (TCSs) are predominant means by which bacteria sense and respond to environment signals. Genome of Pseudomonas putida contains dozens of putative TCS-encoding genes, but phenotypical-genotypical correlation and transcriptional regulation of these genes are largely unknown. Herein, we characterized function and transcriptional regulation of a conserved P. putida TCS, named TarR-TarS. TarS (PP_0769) encodes a potential histidine kinase, and tarR (PP_0768) encodes a potential response regulator. Protein-protein interaction assay and phosphorylation assay confirmed that TarR-TarS was a functional TCS. Growth assay under antibiotics revealed that TarR-TarS positively regulated bacterial resistance to multiple antibiotics. Pull-down assay revealed that TarR directly interacted with PP_0800 (a hypothetical protein) and GroEL (the chaperonin). GroEL played a positive role in antibiotic resistance, while PP_0800 seemed to have no effect on antibiotic resistance. The regulator FleQ indirectly activated tarR-tarS transcription. However, the second messenger c-di-GMP antagonized FleQ activation to inhibit tarR-tarS transcription. The sigma factor FliA directly activated tarR-tarS transcription via a consensus motif. These findings reveal function and transcriptional regulation of TarR-TarS, and enrich knowledge regarding the relationship between c-di-GMP and antibiotic susceptibility in P. putida.

At container terminals, quay cranes, yard trucks, and yard cranes are mainly used to transfer containers. Driven by the demand for a green and low-carbon economy, an integrated scheduling problem considering three types of handling equipment of container handling systems is studied. As the task of transferring each container is completed by the three handling equipment sequentially, the optimal solution may not be found by only studying one type of equipment separately from a green operations perspective. The inter-dependency of different equipment should be considered to guarantee the overall performance of container handling systems with low-carbon operations so as to reduce energy consumption. In this paper, this integrated problem is formulated as a mixed integer linear programming (MILP). Since the MILP cannot be applied to solve large-sized practical problems, a genetic algorithm (GA) is developed. In the proposed GA, a three-dimension chromosome representation is proposed, which integrates the coordination of three handling equipment. A new mechanism including three pairs of crossover and mutation is used in parallel in GA with the aim of enhancing the efficiency of searching for good solutions. Each pair of crossover and mutation is specific to one dimension of a solution. Moreover, a novel heuristic mutation is developed to diversify solutions. The computational results indicate that the developed solution method for the integrated scheduling problem is promising and the heuristic mutation can highly improve the solution quality.

Here, we found that chondroitin polymerizing factor is upregulated in breast carcinoma and associated with worse prognosis according to bioinformatic analysis. Functionally, chondroitin polymerizing factor acts as an oncogene that promotes breast carcinoma cell progression by facilitating proliferation, invasion and migration, as well as by elevating the expression of matrix metallopeptidase 2 and epithelial–mesenchymal transition‐related markers., Chondroitin polymerizing factor (CHPF) plays an important role in the development of certain malignant tumors. However, the role of CHPF in breast carcinoma (BRCA) and its underlying mechanism are still not fully elucidated. Expression profiles for CHPF in BRCA tissues were retrieved from The Cancer Genome Atlas database and used for prognostic analysis. Cell viability, invasion and migration were measured in vitro using MCF7 and MDA‐MB‐231 cell lines upon knockdown or over‐expression of CHPF. Bioinformatic analysis showed that CHPF was substantially upregulated in BRCA tissues, and a quantitative reverse transcriptase‐PCR was performed to confirm its upregulation in BRCA cells. High expression of CHPF was observed to be significantly associated with pathologic stage, metastasis and worse prognosis. We also observed that depletion of CHPF significantly inhibited cell proliferative, invasive and migratory abilities, whereas overexpression of CHPF exerted the opposite effects. Furthermore, analysis of the GEPIA database revealed that CHPF expression is positively correlated with the epithelial–mesenchymal transition‐related markers vimentin, Snail, Slug and motion‐related protein matrix metallopeptidase 2; these findings were confirmed via western blotting. Our data suggest that CHPF may contribute to BRCA progression by modulating epithelial–mesenchymal transition‐related markers and matrix metallopeptidase 2 expression.

Introduction Circulating intact parathyroid hormone (iPTH) levels include full-length (1-84) PTH and long C-PTH fragments, but primarily (7-84) PTH, which have been reported to have antagonistic effects on the bones and kidneys. However, their effects on the cardiovascular system remain unclear. In this study, the relationships between the plasma PTH fragments levels and heart rate variability (HRV) in stage 5 chronic kidney disease (CKD5) patients are explored. Furthermore, the effects of parathyroidectomy (PTX) on the above indices are investigated. Methods In this cross-sectional study, 164 healthy controls and 354 CKD5 patients, including 208 secondary hyperparathyroidism (SHPT) subgroup with PTX, were enrolled. Circulating (7-84) PTH levels were calculated by subtracting plasma (1-84) PTH levels from iPTH levels. The HRV parameters were measured using a 24-hour Holter. Results The baseline levels of plasma iPTH, (1-84) PTH, and (7-84) PTH in the CKD5 patients were 930.40 (160.65, 1792.50) pg/mL, 448.60 (99.62, 850.45) pg/mL, and 468.20 (54.22, 922.55) pg/mL, respectively. In the CKD5 patients, plasma (1-84) PTH levels were independently correlated with the standard deviation of the normal-to-normal R-R intervals (SDNN) and the standard deviation of the five-minute average of the normal R-R intervals (SDANN). With a median follow up time of 6.50 months after PTX in the SHPT patients (n = 30), improved SDNN and SDANN markers were related with decreased (1-84) PTH levels. Furthermore, an improved SDNN was related with decreased (7-84) PTH levels. Conclusions The CKD5 patients’ baseline (1-84) PTH levels were correlated with the SDNN and SDANN. After PTX, an improved SDNN was related with decreased (1-84) PTH and (7-84) PTH levels, while improved SDANN was related with decreased (1-84) PTH levels. No antagonistic effects of (1-84) PTH and (7-84) PTH on HRV were found in the CKD5 patients.

BACKGROUND AND AIMS Calciphylaxis is a rare disease characterized histologically by microvessel calcification and microthrombosis, with high mortality and no proven therapy. Here, we reported multidisciplinary regenerative treatment for rescuing a severe uremic calciphylaxis patient with human amnion-derived mesenchymal stem cells (hAMSCs). METHOD A 34-year-old uremic woman presented progressive skin ischaemia, large areas of painful malodorous ulcers and mummified legs. The patient was diagnosed as calciphylaxis based on clinical manifestations, laboratory examinations and skin pathological features. Because of her refractory to conventional therapy, treatment with hAMSCs was approved. HAMSCs were administered intravenously to the patient at a dose of 1.0 × 106 cells per kilogram of body weight, local intramuscular injection along the wound edge (2.0 × 104 cells/cm2) and external application of the cell culture supernatant on wound surfaces. RESULTS Following up 15 months regularly after hAMSCs treatment, the patient's blood biochemical, inflammatory, mineral and bone metabolic indices improved significantly, with immunoregulation effects, regeneration of skin and soft tissue. Besides, wound healing (Figure 1), pain status and quality of life, evaluated by Pain Visual Analog Scale, Bates-Jensen Wound Assessment and the wound-quality of life questionnaire were also improved significantly (Figure 2). CONCLUSION This case represented the new method of hAMSC regeneration therapy for uremic calciphylaxis with safety and effectiveness, which deserved further investigation. Before hAMSC treatment, the patient had irregular ulcers on the buttocks and lower extremities, some of which were crusted on the surface or had purulent fishy discharge. Skin and soft tissue necrosis can be seen at the ulcerated area of the buttocks, localized deep to the fascia, with purulent secretions on the surface and brown pigmentation of the skin at the edge of the ulcer (Figure 1A and B). Because of her worsening symptoms and signs refractory to conventional therapy, the patient was given intravenous and local intramuscular injections of hAMSCs, supplemented by application of hAMSC culture supernatant to the wound. After 4 months of treatment, the sacrococcygeal wound has reduced size and become shallow with less exudate, some new granulation tissue was visible. The infection was controlled with pain significantly reduced (Figure 1C). After 12 months, most of the sacrococcygeal wound had healed with only a few erosions (Figure1D). Fifteen months later, her skin scarring of the wound was healed without pain (Figure 1E). The pain Visual Analogue Scale (Figure 2A) showed that the pain was unbearable before treatment (10 points) and disappeared after 15 months of hAMSC treatment (0 point). BWAT (Figure 2B) showed that all the 13 indexes got 5 points (worst) before hAMSC treatment, with a total score of 65 points. After 15 months of hAMSC treatment, each index got 1 point (best), and the total score was 13 points. The Wound-QoL questionnaire (Figure 2C) showed that the 17 items were quantified as 4 points (very serious) before treatment, with a total score of 68 points. After 15 months of hAMSC treatment, the score was 0 (none at all), and the total score was 0.

Antibacterial air filtration membranes are essential for personal protection during the pandemic of coronavirus disease 2019 (COVID-19). However, high-efficiency filtration with low pressure drop and effective antibiosis is difficult to achieve. To solve this problem, an innovative electrospinning system with low binding energy and high conductivity was built to enhance the jet splitting, and a fluffy nanofibrous membrane containing numerous ultrafine nanofibers and large quantities of antibacterial agents was achieved, which was fabricated by electrospinning polyamide 6 (PA6), poly(vinyl pyrrolidone) (PVP), chitosan (CS), and curcumin (Cur). The filtration efficiency for 0.3 μm NaCl particles was 99.83%, the pressure drop was 54 Pa, and the quality factor (QF) was up to 0.118 Pa

Autapses selectively form in specific cell types in many brain regions. Previous studies have also found putative autapses in principal spiny projection neurons (SPNs) in the striatum. However, it remains unclear whether these neurons indeed form physiologically functional autapses. We applied whole-cell recording in striatal slices and identified autaptic cells by the occurrence of prolonged asynchronous release (AR) of neurotransmitters after bursts of high-frequency action potentials (APs). Surprisingly, we found no autaptic AR in SPNs, even in the presence of Sr

Autapses (or self-synapses) selectively form in specific cell types in many brain regions including the neocortex and the hippocampus, where they provide feedback control over self-spiking activities. Previous morphological studies also found putative autapses in medium spiny neurons (MSNs) of the striatum. However, it remains unclear whether striatal neurons indeed form physiologically functional autapses. We performed whole-cell recordings from striatal neurons in acute mouse brain slices, and identify autaptic neurons by the occurrence of prolonged asynchronous release (AR) of neurotransmitter after high-frequency burst of action potentials (APs) in the same cell. To our surprise, we found no autaptic release in all recorded MSNs after the AP burst, even in the presence of Sr2+ that should desynchronize and thus prolong synaptic vesicle release. In sharp contrast, we observed robust autaptic AR events in half of the recorded parvalbumin (PV)-positive neurons. Autaptic responses in PV cells were mediated by GABAA receptors, and the AR strength was dependent on the frequency and the number of APs during the burst. Further simulation results show that autapses regulate burst spiking in PV cells by providing self-inhibition and thus shape network oscillation at certain frequencies. Together, we reveal that, distinct from MSNs, striatal PV neurons form functional autapses, activation of which would regulate self-activities in PV cells, and thereby shape MSN firing and network oscillations.Author summarySynapses, which usually occur between two neurons, are key structures for signal communication in the nervous system. However, some types of neurons form autapses, where a neuron synapses onto itself. Autaptic transmission provides feedback signal regulating self-spiking activities. Neuronal and network activities in the striatum play critical roles in motor control and other brain functions. Previous studies suggest formation of autapses in striatal principal MSNs, but it remains unclear whether striatal neurons form functional autapses. We performed direct recordings from striatal neurons and examined the occurrence of autaptic transmission in acute brain slices. Surprisingly, we did not detect any autaptic responses in MSNs. A large proportion of striatal PV neurons, however, produced robust autaptic GABA release upon high-frequency stimulation, indicating selective formation of autapses in striatal PV cells. Our computation simulations suggest that autapses provide self-inhibition in PV cells and thereby shape activities in MSNs and striatal network, particularly when PV cells discharge at high frequencies corresponding to a high dopamine state. Together, our findings indicate that PV cells, but not MSNs, in the striatum form physiologically functional autapses. Autapses in PV cells could be essential circuit elements in the striatum and contribute to striatal functions, such as motor control.

Based on the original text information, this paper converts the users' theme preferences and text sentiment features into attention information and combines different forms with the LSTM (Long Short-Term Memory) model to predict the personality characteristics of social network users. Finally, the experimental results of multiple groups’ show that the Attention-based LSTM model proposed in the paper can achieve better results than the currently popular methods in the recognition of user personality traits and that the model has good generalization ability.

Microbe-secreted EPSs are high-molecular-weight polysaccharides that have the potential to be used as industrially important biomaterials. The EPS Pea in P. putida is essential for wrinkly colony morphology and pellicle formation.

Calciphylaxis is a rare disease characterized histologically by microvessel calcification and microthrombosis, with high mortality and no proven therapy. Here, we reported a severe uremic calciphylaxis patient with progressive skin ischemia, large areas of painful malodorous ulcers, and mummified legs. Because of the worsening symptoms and signs refractory to conventional therapies, treatment with human amnion-derived mesenchymal stem cells (hAMSCs) was approved. Preclinical release inspections of hAMSCs, efficacy, and safety assessment, including cytokine secretory ability, immunocompetence, tumorigenicity, and genetics analysis in vitro, were introduced. We further performed acute and long-term hAMSC toxicity evaluations in C57BL/6 mice and rats, abnormal immune response tests in C57BL/6 mice, and tumorigenicity tests in neonatal Balbc-nu nude mice. After the preclinical research, the patient was treated with hAMSCs by intravenous and local intramuscular injection and external supernatant application to the ulcers. When followed up to 15 months, the blood-based markers of bone and mineral metabolism improved, with skin soft tissue regeneration and a more favorable profile of peripheral blood mononuclear cells. Skin biopsy after 1-month treatment showed vascular regeneration with mature noncalcified vessels within the dermis, and 20 months later, the re-epithelialization restored the integrity of the damaged site. No infusion or local treatment-related adverse events occurred. Thus, this novel long-term intravenous combined with local treatment with hAMSCs warrants further investigation as a potential regenerative treatment for uremic calciphylaxis due to effects of inhibiting vascular calcification, stimulating angiogenesis and myogenesis, anti-inflammatory and immune modulation, multidifferentiation, re-epithelialization, and restoration of integrity.

This paper presents a novel dual-band circularly polarized patch antenna for precise satellite navigation. The radiation elements are composed of the inner cross-shaped patch and the outer annular patch which are printed on the same surface of one substrate. Two patches work in different bands, respectively, and emit dual-band circularly polarized radiation. In order to obtain a more compact antenna to meet the application of precise satellite navigation, we vertically place four metal cylinders under the ends of the cross-shaped patch to form four capacitive loadings to lower the resonant frequency of the inner cross-shaped patch. A capacitive coupling feed structure is used to match the input impedance of a patch antenna and make the antenna compact enough. The simulated and measured results show that the proposed antenna can produce appropriate dual-band circularly polarized radiation patterns for precise satellite navigation. The measured results of the antenna illustrate that maximum RHCP gain of the antenna is 4.72 dBi in the low band and 3.98 dBi in the high band, the 3 dB gain bandwidth is 70 MHz in the low band and 65 MHz in the high band.

Huangqin decoction (HQD), composed of Scutellaria(Huangqin), Peony(Shaoyao), Liquorice(Gancao) and Jujube(Dazao), is a traditional Chinese medicine prescription, originated from treatise on Febrile Diseases, has the functions of clearing heat, stopping benefits and relieving pain. It is the original prescription for treating heat and relieving dysentery, and is commonly used in clinic for diarrhea and other diseases. In ulcerative colitis, damp-heat syndrome is the most common. However, its mechanism of action is not completely clear.The purpose of the research is to investigate the protective effect of HQD on ulcerative colitis rats and the regulation effect of mitochondrial DNA, TLR4, p-Akt, p-PI3K protein and microbiota.The effects of HQD anti-UC were investigated by fluorescence quantitative PCR, cytokine level and histopathological analysis in DSS-induced ulcerative colitis (UC) rats. The content of mtDNA in colon epithelial cells of rats in each group was detected by fluorescence quantitative PCR, p-PI3K, p-Akt and TLR4 protein expressions in colon tissues of rats in each group were detected by Western blotting. IL-6, IL-17 and IL-23 inflammatory factors were detected by ELISA. The effect of HQD on intestinal microbiota of rats with ulcerative colitis was studied by high-throughput sequencing technology, and the correlation between mtDNA level and inflammatory factors as well as protein expression in colonic epithelium of rats with ulcerative colitis was analyzed by SPSS23.0.HQD significantly alleviated UC symptoms by improving the mucosal intestinal epithelial cell structure, mental state, hair gloss, fecal occult blood, lamina propria intestinal glands and inflammatory cell infiltration. And HQD reduced the pro-inflammatory cytokines in the colonic epithelium of UC rats Production of IL-6, IL-17 and IL-23. The HE stained section of colon tissue showed a complete intestinal epithelial mucosal layer structure. The structure of epithelial cells was more normal and abundant. There were more goblet cells in lamina propria adenoma, which improved the infiltration of inflammatory cells. HQD significantly inhibited the mtDNA content in rat colonic epithelial tissue, and significantly inhibited the expression of TLR4, p-PI3K and p-Akt inflammatory signaling pathways. The results of the microbiota experiment showed that the abundance of HQD in the phylum Firmicutes increased, and the number of Bacteroides phylum decreased (p 0.05). At the genus level, HQD significantly increased Lactobacillus and Firmicutes Bacteroides, while Treponema and Bacteroides were significantly reduced (p 0.05).HQD has a certain protective effect on rats with damp heat ulcerative colitis. Its mechanism may be related to regulating the expression of p-PI3K, p-Akt and TLR4 proteins, mitochondrial DNA as well as microbiota.

Publisher’s Note: This paper, originally published on 9 October 2021, was withdrawn on 13 October 2021 per author request.

Calciphylaxis is a rare disease characterized histologically by microvessel calcification and microthrombosis, with high mortality and no proven therapy. We reported a severe uremic calciphylaxis patient with progressive skin ischemia, large areas of painful malodorous ulcers and mummified legs. Because of her rapid progression and refractory to conventional therapy, human amnion-derived mesenchymal stem cells (hAMSCs) treatment was approved. Establishment and release inspection of hAMSCs, efficacy and safety assessment including cytokines secretory ability, immunocompetence, tumorigenicity and genetics analysisin vitrowere introduced. We further performed acute and long-term hAMSC toxity evaluations in C57BL/6 mice/rats, abnormal immune response tests in C57BL/6 mice and tumorigenic tests in the neonatal NU nude mice. After pre-clinical research, she was treated by hAMSCs with intravenous and local intramuscular injection and external supernatants application to her ulcers. When followed up to 15 months, her blood-based markers of bone and mineral metabolism were improved, with regeneration of skin soft tissue and a more favorable profile of peripheral blood mononuclear cells. Skin biopsy after 1 month treatment showed vascular regeneration with mature non-calcified vessels within dermis and 20 months later re-epithelialization restored the integrity of damaged site. No infusion or local treatment related adverse events occurred. To the best of our knowledge, this is the first evidence for the clinical use of hAMSCs. These findings suggest hAMSCs warrant further investigation as a potential regenerative treatment for uremic calciphylaxis with effects of inhibiting vascular calcification, stimulating angiogenesis and myogenesis, anti-inflammatory and immune modulation, multi-differentiation, re-epithelialization and restorage of integrity.

Aiming at the path tracking control of the underactuated USV in the horizontal, the LOS guidance strategy for USV path tracking control is studied in detail, which can be divided into two categories the LOS guidance strategy based on the encirclement and the look ahead distance. The advantages and disadvantages of the two algorithms are discussed. Next, the mathematical model of the USV in the three-degree-of-freedom is established. Then, based on the LOS guidance strategy of look ahead distance and output feedback control, the path tracking control algorithm is designed. The algorithm is based on the stabilization of heading angle, longitudinal velocity and position error to realize the straight and curve line path following of the underactuated USV. Finally, the simulation experiment proves that the path following control algorithm proposed in the paper has good dynamic performance and smaller steady-state error.

The bacterial second messenger cyclic diguanylate (c-di-GMP) modulates plankton-to-biofilm lifestyle transition of Pseudomonas species through its transcriptional regulatory effector FleQ. FleQ regulates transcription of biofilm- and flagellum-related genes in response to c-di-GMP. Through transcriptomic analysis and FleQ-DNA binding assay, this study identified five new target genes of c-di-GMP/FleQ in P. putida, including PP_0681, PP_0788, PP_4519 (lapE), PP_5222 (cyaA), and PP_5586. Except lapE encoding an outer membrane pore protein and cyaA encoding an adenylate cyclase, the functions of the other three genes encoding hypothetical proteins remain unknown. FleQ and c-di-GMP coordinately inhibit transcription of PP_0788 and cyaA and promote transcription of PP_0681, lapE, and PP_5586. Both in vitro and in vivo assays show that FleQ binds directly to promoters of the five genes. Further analyses confirm that LapE plays a central role of in the secretion of adhesin LapA and that c-di-GMP/FleQ increases lapE transcription, thereby promoting adhesin secretion and biofilm formation. The adenylate cyclase CyaA is responsible for synthesis of another second messenger, cyclic AMP (cAMP). FleQ and c-di-GMP coordinate to decrease the content of cAMP, suggesting that c-di-GMP and FleQ coregulate cAMP by modulating cyaA expression. Overall, this study adds five new members to the c-di-GMP/FleQ-regulated gene family and reveals the role of c-di-GMP/FleQ in LapA secretion and cAMP synthesis regulation in P. putida. IMPORTANCE c-di-GMP/FleQ promotes the plankton-to-biofilm lifestyle transition at the transcriptional level via FleQ in Pseudomonas species. Identification of new target genes directly regulated by c-di-GMP/FleQ helps to broaden the knowledge of c-di-GMP/FleQ-mediated transcriptional regulation. Regulation of lapE by c-di-GMP/FleQ guarantees highly efficient LapA secretion and biofilm formation. The mechanism of negative correlation between c-di-GMP and cAMP in both P. putida and P. aeruginosa remains unknown. Our result concerning transcriptional inhibition of cyaA by c-di-GMP/FleQ reveals the mechanism underlying the decrease of cAMP content by c-di-GMP in P. putida.

Cyclic diguanylate (c-di-GMP) is a broadly conserved bacterial signalling molecule that modulates diverse cellular processes, such as biofilm formation, colony morphology and swimming motility. The intracellular level of c-di-GMP is controlled by diguanylate cyclases (DGCs) with GGDEF domain and phosphodiesterases (PDEs) with either EAL or HD-GYP domain. Pseudomonas putida KT2440 has a large group of genes on its genome encoding proteins with GGDEF/EAL/HD-GYP domains. However, phenotypic-genotypic correlation and c-di-GMP metabolism of these genes were largely unknown. Herein, by systematically constructing deletion mutants/overexpression strains of the 42 predicted c-di-GMP metabolism-related genes and analysing the phenotypes, we preliminarily revealed the role of each gene in biofilm formation, colony morphology and swimming motility. Subsequent results from protein sequence alignments and cellular c-di-GMP assessment indicated that 25 out of the 42 genes were likely to encode DGCs, nine genes were predicted to encode PDEs, four genes encoded bifunctional enzymes and the other four genes encoded enzymatically inactive proteins. This study offers a basic understanding of the roles of these 42 genes and can serve as a toolkit for investigators to further elucidate the functions of these GGDEF and EAL/HD-GYP domain-containing proteins.