A Hybrid Framework of Reinforcement Learning and Convex Optimization for UAV-Based Autonomous Metaverse Data Collection

Unmanned aerial vehicles (UAVs) are promising for providing communication services due to their advantages in cost and mobility, especially in the context of the emerging Metaverse and Internet of Things (IoT). This paper considers a UAV-assisted Metaverse network, in which UAVs extend the coverage of the base station (BS) to collect the Metaverse data generated at roadside units (RSUs). Specifically, to improve the data collection efficiency, resource allocation and trajectory control are integrated into the system model. The time-dependent nature of the optimization problem makes it non-trivial to be solved by traditional convex optimization methods. Based on the proposed UAV-assisted Metaverse network system model, we design a hybrid framework with reinforcement learning and convex optimization to {cooperatively} solve the time-sequential optimization problem. Simulation results show that the proposed framework is able to reduce the mission completion time with a given transmission power resource.Comment: This paper appears in IEEE Network magazin

Interventional therapy of diabetes mellitus type 2 complicated with acute cerebral hemorrhage by using dexmedetomidine

AbstractObjectiveTo study the effects of dexmedetomidine on cerebral injury, inflammation, oxidative stress and renal function of patients with diabetes mellitus type 2 complicated with acute cerebral hemorrhage.MethodsA total of 98 cases who had been diagnosed with diabetes mellitus type 2 complicated with acute cerebral hemorrhage and treated with interventional therapy in Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from September 2014 January 2016 were chosen to be our study subjects. Among them, 50 cases given dexmedetomidine treatment in the process of anesthesia were included in the dexmedetomidine group (Group A), while the other 48 cases treated with equal amount of normal saline were considered as the negative control group. The postoperative cerebral injury indexes and the serum biochemical indexes were detected after 24 h.ResultsThe contents of serum S100β [(2.1 ± 0.2) μg/L] and neuron-specific enolase (NSE) [(14.2 ± 1.3) μg/mL] in Group A were all significantly lower than serum S100β [(2.9 ± 0.3) μg/L] and NSE [(16.6 ± 1.7) μg/mL] of patients in negative control group. The contents of cerebrospinal fluid S100β [(0.9 ± 0.1) μg/L] and NSE [(10.7 ± 1.3) μg/mL] in Group A were all significantly lower than cerebrospinal fluid S100β [(1.3 ± 0.2) μg/L] and NSE [(15.3 ± 1.7) μg/mL] of patients in negative control group. The contents of erythrocyte sedimentation rate [(11.7 ± 2.5) mm/h], c-reactive protein [(2.3 ± 0.4) mg/L], urea nitrogen [(10.7 ± 1.2) mmol/L] and serum creatinine [(151.6 ± 14.9)] μmol/L in Group A were all significantly lower than erythrocyte sedimentation rate [(23.6 ± 3.8) mm/h], c-reactive protein [(6.9 ± 1.1) mg/L], urea nitrogen [(16.7 ± 1.7) mmol/L] and serum creatinine [(192.5 ± 18.3)] μmol/L of patients in negative control group.ConclusionsThe application of dexmedetomidine in the interventional therapy of diabetes mellitus type 2 complicated with acute cerebral hemorrhage could protect brain and renal functions and reduce systemic inflammatory responses

Impact of a staggered scaffold structure on the mechanical properties and cell response in bone tissue engineering

The primary goal of bone tissue engineering is to fabricate scaffolds that can provide a microenvironment similar to that of natural bone. Therefore, various scaffolds have been designed to replicate the bone structure. Although most tissues exhibit complicated structures, their basic structural unit includes stiff platelets arranged in a staggered micro-array. Therefore, many researchers have designed scaffolds with staggered patterns. However, relatively few studies have comprehensively analyzed this type of scaffold. In this review, we have analyzed scientific research pertaining to staggered scaffold designs and summarized their effects on the physical and biological properties of scaffolds. Compression tests or finite element analysis are typically used to evaluate the mechanical properties of scaffolds, and most studies have performed experiments in cell cultures. Staggered scaffolds improve mechanical strength and are beneficial for cell attachment, proliferation, and differentiation in comparison with conventional designs. However, very few have been studied in vivo experiments. Additionally, studies on the effect of staggered structures on angiogenesis or bone regeneration in vivo, particularly in large animals, are required. Currently, with the prevalence of artificial intelligence (AI)-based technologies, highly optimized models can be developed, resulting in better discoveries. In the future, AI can be used to deepen our understanding on the staggered structure, promoting its use in clinical applications.publishedVersio

Impact of Ultra-Low Interfacial Tension on Enhanced Oil Recovery of Ultra-Low Permeability Reservoir

Ultra-low permeability reservoirs have the characteristics of complex pore throat structure, generally higher injection pressure and lower oil recovery. By means of casting thin sections, pore structure of selected ultra-low permeability core was surveyed. The core was classified into low porosity, low permeability and without natural fractures. Vast majority of throats of the core varied in width from 2.5 μm to 15 μm. Core displacement experiments showed that surfactant flooding could have certain effect of reducing injection pressure and enhancing oil recovery. When interfacial tension was 5.93×10-2 mN/m, decompression rate reached 7.65%, and recovery was improved by 4.09%. And when interfacial tension was 4.9×10-5 mN/m, decompression rate reached 25%, and recovery was improved by 11.6%. The lower interfacial tension is, the better the effect of reducing injection pressure is, and the higher the extent of enhancing oil recovery is. In general, surfactants have a great application prospect on the oil field development of ultra-low permeability reservoir, and the interfacial tension should be reduced as far as possible.Key words: Low permeability; Surfactant; Interfacial tension; Emulsion; Enhancing oil recover

1-(4-{[(E)-3-Eth­oxy-2-hy­droxy­benzyl­idene]amino}­phen­yl)ethanone oxime

In the title compound, C17H18N2O3, the benzene rings form a dihedral angle of 3.34 (2)°. There is a strong intra­molecular O—H⋯N hydrogen bonds (which induces planarity of the structure). In the crystal, mol­ecules are linked by pairs of O—H⋯N hydrogen bonds, forming inversion dimers

EFFECT OF CHINESE MEDICAL HERBS- BURN LINIMENT ON DEEP SECOND DEGREE BURN IN RATS

Background: Burn Liniment (BL) is a popular traditional Chinese medicine formula consisting five herbal medicines (Flos Lonicerae, Rhizoma Polygoni Cuspidati, Pericarpium Granati,Terminalia chebula Retz. and Galla Chinensis), that has been used in China for centuries to cure burn. This study investigated the healing effect of BL on deep second degree burn wounds in rats. Materials and methods: The animals were divided into four groups including control group, model group,1% silver sulfadiazine (SSD) group and BL group. On days 0,3,7,14 and 21,animal weight, wound area as well as histo-pathological observations of the skin were evaluated in different groups. Serum anti-intercellular adhesion molecule 1(ICAM-1), IL-10 levels and myeloperoxidase (MPO) activity were measured on the 21st day. HPLC chromatography of BL was prepared and concentrations of active constituents were determined. Antibacterial test and toxicological test were also performed. Results: The average wound area of BL treatment group was also significantly smaller than model control rats on days 14 and 21. Serum anti-intercellular adhesion molecule 1(ICAM-1) levels and myeloperoxidase (MPO) activity of BL group decreased significantly than in model rats on day 21 while IL-10 level of BL group increased remarkably than in model rats on the 21st day, showing that BL has strong anti-inflammatory activity on burned rats. The histological studies indicated that inflammatory cells disappeared significantly and were replaced by new granulation tissue, and epithelialization progressed quickly and was treated with BL on the 21st day. Meanwhile, HPLC chromatography of BL was prepared and concentration of Chlorogenic acid, Polydatin and Gallic acid from BL were determined. Antibacterial test revealed that the MIC of BL on Staphyloccocus aureus, Pseudomonas aeruginosa and Escherichia coli were 1.56, 6.25 and 1.56 mg•mL-1 respectively. Toxicological test showed that BL does not induce skin irritation or sensitivity signs and has no acute toxicity reaction. Conclusions: Our study revealed that BL could enhance cutaneous burn wound healing effectively. It also showed strong anti-inflammatory and antibacterial activity in rats

Temperature-dependent structure of an intermetallic ErPd2_2Si2_2 single crystal: A combined synchrotron and in-house X-ray diffraction study

We have grown intermetallic ErPd$_2$Si$_2$ single crystals employing laser-diodes with the floating-zone method. The temperature-dependent crystallography was determined using synchrotron and in-house X-ray powder diffraction measurements from 20 to 500 K. The diffraction patterns fit well with the tetragonal $I$4/$mmm$ space group (No. 139) with two chemical formulas within one unit cell. Our synchrotron X-ray powder diffraction study shows that the refined lattice constants are $a$ = 4.10320(2) {\AA}, $c$ = 9.88393(5) {\AA} at 298 K and $a$ = 4.11737(2) {\AA}, $c$ = 9.88143(5) {\AA} at 500 K, resulting in the unit-cell volume $V$ = 166.408(1) {\AA}$^3$ (298 K) and 167.517(2) {\AA}$^3$ (500 K). In the whole studied temperature range, we did not find any structural phase transition. Upon cooling, the lattice constants a and c are shortened and elongated, respectively.Comment: 5 Figures, 4 Table

A UPLCâ MS/MS method for simultaneous determination of five flavonoids from Stellera chamaejasme L. in rat plasma and its application to a pharmacokinetic study

Stellera chamaejasme L. has been used as a traditional Chinese medicine for the treatment of scabies, tinea, stubborn skin ulcers, chronic tracheitis, cancer and tuberculosis. A sensitive and selective ultraâ high liquid chromatographyâ tandem mass spectrometry (UPLCâ MS/MS) method was developed and validated for the simultaneous determination of five flavonoids (stelleranol, chamaechromone, neochamaejasmin A, chamaejasmine and isochamaejasmin) of S. chamaejasme L. in rat plasma. Chromatographic separation was accomplished on an Agilent Poroshell 120 ECâ C18 column (2.1 à 100â mm, 2.7â μm) with gradient elution at a flow rate of 0.4â mL/min and the total analysis time was 7â min. The analytes were detected using multiple reaction monitoring in positive ionization mode. The samples were prepared by liquidâ liquid extraction with ethyl acetate. The UPLCâ MS/MS method was validated for specificity, linearity, sensitivity, accuracy and precision, recovery, matrix effect and stability. The validated method exhibited good linearity (r â ¥ 0.9956), and the lower limits of quantification ranged from 0.51 to 0.64â ng/mL for five flavonoids. The intraâ and interâ day precision were both <10.2%, and the accuracy ranged from â 11.79 to 9.21%. This method was successfully applied to a pharmacokinetic study of five flavonoids in rats after oral administration of ethyl acetate extract of S. chamaejasme L.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144258/1/bmc4189.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144258/2/bmc4189_am.pd