In this paper, we investigate the design of energy-efficient space-time modulation for peak-limited MISO broadcast visible light communication (VLC) systems by cooperatively managing the non-negative ...multiuser interference. We first characterize a constellation-optimal structure that maximizes the worst-case minimum Euclidean distance of all users for a general space-time modulation design. It turns out that the optimal space-time constellation can be constructed via the spatial repetition of the optimal multidimensional constellation in time dimension over ideal additive white Gaussian noise channels. Then, based on this structure, we specifically design two classes of energy-efficient time-dimensional constellations: 1) for the integer overall bit rate, we design the optimal linear precoded block design, which admits fast maximum likelihood demodulation algorithms. 2) for the non-integer case, we propose a nonlinear precoding scheme called block coded modulation, which sums the code word sets of the optimal linear design and a block channel code. In addition, we show that these two classes of designs are addition-unique, thus, generating an energy-efficient mapping from users' data to the transmitted constellations. This property enables the efficient demodulation of the sum signal from a noisy received signal as well as the decoding of individual signal from the estimated sum signal. Extensive computer simulations indicate that our addition-unique designs have remarkable performance gains over the currently available zero-forcing, minimum mean square error and time-division multiple access methods for the multiuser multi-input-single-output VLC broadcast systems.
In this paper, joint direction-of-departure (DOD) and direction-of-arrival (DOA) estimation for bistatic multiple-input-multi-output (MIMO) radar in an unknown spatially correlated noise environment ...is investigated. The signal model is based on the assumption that the waveforms are transmitted by two separated subarrays having M 1 and M 2 sensors and received by two separated subarrays having N 1 and N2 sensors, respectively. The received data are pulse-compressed using a matching matrix consisting of M=M 1 +M 2 orthogonally transmitted waveforms. The joint covariance matrix of unknown correlated noise is analyzed. A novel algorithm is proposed by jointly estimating the DOD and DOA with transmitter and receiver subarrays in unknown noise. The joint estimation algorithm is based on the canonical correlation decomposition (CCD) and exploits the shift-invariance properties in the Kronecker product structure of each column of the various steering matrices. The estimated DOA and DOD can be automatically paired correspondingly. In addition, the formulas of stochastic Cramér-Rao bounds (CRB) for DOD and DOA estimation are derived. Simulations show that our method can effectively improve the performance of estimation in unknown correlated noise environments and is insensitive to having different noise environments in the two subarrays.
Colorectal cancer (CRC) is one of the most common types of cancers in humans and is closely linked to the global cancer-related mortalities worldwide. Molecular pathological epidemiology studies can ...reveal the risk factors of CRC and contribute to biomarker research and precision medicine. The current clinical treatment for CRC mainly involves surgery and chemotherapy. However, because of the occurrence of side effects and the emergence of drug resistance, there is an urgent need to find new and more effective drugs for CRC treatment. An increasing number of studies have demonstrated that many natural products possess effective anti-CRC effects and may serve as alternative chemotherapy agents for CRC treatment. In this review, we summarize the natural products with anti-CRC effects from different sources based on the chemical structures such as alkaloids, polysaccharides, polyphenols, terpenoid, unsaturated fatty acids, and discuss the natural product-derived drugs used clinically for colorectal cancer treatment. Furthermore, natural products of marine origin are also discussed for their enormous potential to serve as the candidate drugs. Notably, we generalize the experiment-based molecular mechanisms and the regulatory networks whereby natural products exert anticancer effects on cell proliferation, metastasis, apoptosis, autophagy, and angiogenesis.
This paper studies the prescribed-time stabilization problem of a class of uncertain linear systems. With the aid of some properties of a class of parametric Lyapunov equations and time-varying ...Lyapunov-like functions, time-varying linear smooth observer-based output feedback controllers are designed to achieve the prescribed-time stabilization. The studied uncertain linear systems can include part of the linear parameter varying systems and the semi-Markovian jump linear systems. As an application, some control problems of aircraft systems have been addressed. The efficacy of the proposed approaches is confirmed through numerical simulations.
In this paper, the prescribed-time control problem for a class of high-order nonholonomic systems is investigated. With the aid of a novel state transformation, the nonholonomic systems are ...decoupled. Further, a time-varying high-gain feedback controller is constructed by backstepping. It is shown that the proposed control law can achieve the prescribed-time convergence for high-order nonholonomic systems and the controller is bounded. Numerical examples verify the effectiveness of the method proposed in this paper.
The self-assembly of well-defined 2D supramolecular polymers in solution has been a challenge in supramolecular chemistry. We have designed and synthesized a rigid stacking-forbidden ...1,3,5-triphenylbenzene compound that bears three 4,4′-bipyridin-1-ium (BP) units on the peripheral benzene rings. Three hydrophilic bis(2-hydroxyethyl)carbamoyl groups are introduced to the central benzene ring to suppress 1D stacking of the triangular backbone and to ensure solubility in water. Mixing the triangular preorganized molecule with cucurbit8uril (CB8) in a 2:3 molar ratio in water leads to the formation of the first solution-phase single-layer 2D supramolecular organic framework, which is stabilized by the strong complexation of CB8 with two BP units of adjacent molecules. The periodic honeycomb 2D framework has been characterized by various 1H NMR spectroscopy, dynamic light scattering, X-ray diffraction and scattering, scanning probe and electron microscope techniques and by comparing with the self-assembled structures of the control systems.
Two novel C(sp3)−H functionalization of inert alkanes and visible‐light promoted oxidation decarboxylation of N‐hydroxyphthalimide (NHP) esters to access polycyclic quinazolinones have been ...described. These methods do not involve metal catalysts and are carried out in water or water/DMSO media. The wide substrate scope, even including the seven‐membered ring under mild reaction conditions, demonstrate the practicability of these strategies.
This work describes the cleavage of the C(sp3)−H bond of inert alkanes and the visible‐light promoted oxidation decarboxylation of NHP‐esters to form alkyl radicals, which then efficiently synthesize valuable polycyclic quinazolinones through radical addition and cyclization. Both methods were carried out in water or water/DMSO media without metal catalysts with good functional group compatibility.
Connective tissue growth factor (CTGF) is a key signaling and regulatory molecule involved in different biological processes, such as cell proliferation, angiogenesis, and wound healing, as well as ...multiple pathologies, such as tumor development and tissue fibrosis. Although the underlying mechanisms of CTGF remain incompletely understood, a commonly accepted theory is that the interactions between different protein domains in CTGF and other various regulatory proteins and ligands contribute to its variety of functions. Here, we highlight the structure of each domain of CTGF and its biology functions in physiological conditions. We further summarized main diseases that are deeply influenced by CTGF domains and the potential targets of these diseases. Finally, we address the advantages and disadvantages of current drugs targeting CTGF and provide the perspective for the drug discovery of the next generation of CTGF inhibitors based on aptamers.
The effects of different heat treatments on the structure and functional properties of quinoa protein isolates (QPI) were investigated. QPI‐MW and QPI‐BL still had good solubility, emulsification and ...gelability and seemed to be more suitable for application in thermally processed foods. Microwave heating and boiling might be better heat treatment methods for QPI.
Summary
The effects of microwave heating (MW), steaming (SM), boiling (BL) and baking (BK) on the structure and functional properties of quinoa protein isolates (QPI) were investigated. SDS‐PAGE showed the 20–30 kDa band strength of QPI‐BL was enhanced, which indicated the disulphide bond was broken and protein molecules dissociated. Due to the recombination of subunits, some large molecular weight or insoluble polymer components of QPI‐SM and QPI‐BK did not pass through the gel. Microwave heating and boiling showed negative effects for α‐helix and positive effects for β‐sheet, which implied the molecular structure was transformed from ordered to disordered, the secondary structure became loose. The reduction of free SH (sulfhydryl) and surface hydrophobicity implied that aggregation and cross‐linking of protein molecules for QPI‐SM and QPI‐BK. QPI, QPI‐MW and QPI‐BL exhibited better solubility, which was related to the water holding capacity (WHC) and emulsification. For QPI‐SM and QPI‐BK, functional properties (including solubility, WHC and gel‐forming ability) decreased due to molecular aggregation. Heat treatments significantly affect the structure and functional properties of QPI, the current research showed that microwave heating and boiling might be better heat treatment methods for QPI and would help the development of quinoa protein products.
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