Radiation therapy performs an important function in cancer treatment. However, resistance of tumor cells to radiation therapy still remains a serious concern, so the study of radiosensitizers has ...emerged as a persistent hotspot in radiation oncology. Along with the rapid advancement of nanotechnology in recent years, the potential value of nanoparticles as novel radiosensitizers has been discovered. This review summarizes the latest experimental findings both in vitro and in vivo and attempts to highlight the underlying mechanisms of response in nanoparticle radiosensitization.
A high proportion of species native to China from the genus Dendrobium (Orchidaceae) have been used as folk medicine for more than 2300 years. The fresh or dried stem of many Dendrobium species are ...regarded as “superior grade” tonic in Traditional Chinese Medicine (TCM), for their traditional properties of nourishing the kidney, moisturizing the lung, benefiting the stomach, promoting the production of body fluids and clearing heat.
This review aims to provide comprehensive and updated information on the diversity of Dendrobium species used in TCM and the development of the Dendrobium industry. The supply and demand of the Chinese medicinal Dendrobium are investigated. Moreover, we discuss the problems the industry faces and the relationship between the cultivation and species conservation.
The available information on many Dendrobium species (especially D. officinale) was collected from the electronic databases (using Pubmed, CNKI, Baidu scholar, Google scholar and Web of Science). We also obtained information from communication with specialists with profound knowledge in related research field and industry practitioners. Information was also obtained from website of the Forestry Bureau or relevant government departments, online databases, books, Ph.D. dissertations and M.Sc. theses.
Approximately 41 species in genus Dendrobium have been recorded in TCM. The development of the Dendrobium industry could be divided into three phases: (a) the wild-collection phase, (b) the massive commercial artificial-sheltered cultivation phase and (c) the diversified ecologically-friendly cultivation phase. The development of seedlings production technology, the improvement of substrates and the integration of cultivation technology support the rapid increase of Dendrobium herbs in the Chinese TCM market. Doubts around the quality and efficacy of product in artificial-sheltered cultivation, the lack of product standards and the low level of product development have limited the utilization for TCM and hampered the development of the Dendrobium industry. Both the artificial-sheltered cultivation and ecologically-friendly cultivation contribute to the conservation of Dendrobium species, through the use seedlings derived from seeds of sexual reproduction rather than meristematic-based clonal propagation.
This review summarizes the species and cultivation history of medicinal herbs in the Dendrobium. The review can help inform future scientific research towards the TCM in Dendrobium, including mycorrhizal technology and microorganism fertilizer, pharmacological studies, the directed cultivation of varieties and diversified product. It is suggested that Dendrobium cultivation has a great potential to link the commercial TCM industry together with initiatives of biodiversity conservation.
In this paper we prove some improved Caffarelli–Kohn–Nirenberg inequalities and uncertainty principle for complex- and vector-valued functions on
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•Existing large-scale crowd evacuation simulation methods are challenging.•We proposed a chain navigation grid for virtual reality large-scale crowd evacuation simulation.•Traditional cellular ...automata crowd evacuation simulation algorithms to virtual reality scenes.•The chain evacuation navigation grid transforms the discrete crowd movement into continuous.•Evacuation efficiency improved by about 6%.
Large-scale crowd evacuation simulation in virtual reality is of great significance for emergency response. However, the existing large-scale crowd evacuation simulation methods are challenging to apply to the virtual reality scene. Thus, the efficiency of large-scale crowd rendering in virtual reality needs to be improved. Here we proposed a chain navigation grid for virtual reality large-scale crowd evacuation simulation. The objective of this study was to apply traditional cellular automata crowd evacuation simulation algorithms to virtual reality scenes through a chain navigation grid. Combined with the characteristics of crowd movement, we proposed the vertex raster rendering method to efficiently visualize large-scale crowds in virtual reality scenes. Finally, we constructed two evacuation scenes and carried out experimental analyses. The results show that the chain evacuation navigation grid can transform the discrete crowd movement of cellular automata into continuous crowd movement in virtual reality and can connect multiple cellular automata corresponding to multi-floors. Compared with the evacuation results of Pathfinder software, the chain evacuation navigation can add the factor of environmental familiarity. Therefore, this study improved evacuation simulation by increasing about 6% efficiency in time and computing process. Compared with the traditional crowd evacuation rendering method, the vertex raster rendering method increases the maximum number of people rendering from 2 times to 31 times.
The BeiDou navigation satellite system (BDS) provides precise positioning, navigation, and timing (PNT) services in the Asia-Pacific Region, but the BDS-based structural health monitoring (SHM) ...approach (SHM) is rarely studied, especially in civil engineering. Moreover, how BDS can be applied to complete the tasks of SHM in a real project is also not fully investigated, especially working in conjunction with other techniques. This study aims to propose a BDS-based approach for SHM in civil engineering. The performance of the proposed approach is investigated through a case study-the Tianhan Grand Theater (TGT). A specific Tianhan system corresponding to BDS is proposed to complete the SHM tasks of TGT. Based on the collected data, the trusses with maximum displacement and stress are found by BDS to evaluate structural health in the construction stage. The results show that the maximum displacement and stress have certain safety reserves and meet the requirements of the specifications and regulations. Thus, BDS can satisfactorily complete the tasks of SHM for Long-span steel structures. This study gives a clear view to engineers and researchers that how to apply BDS in structural construction and provides a valuable real case for evaluating the performance of BDS in SHM.
This study devotes to uncertainty principles under the linear canonical transform (LCT) of a complex signal. A lower-bound for the uncertainty product of a signal in the two LCT domains is proposed ...that is sharper than those in the existing literature. We also deduce the conditions that give rise to the equal relation of the new uncertainty principle. The uncertainty principle for the fractional Fourier transform is a particular case of the general result for LCT. Examples, including simulations, are provided to show that the new uncertainty principle is truly sharper than the latest one in the literature, and illustrate when the new and old lower bounds are the same and when different.
Stable and crystalline pure-phase gadolinium hydroxide (Gd(OH)3) with diameters of approximately 100–200 nm and lengths of 200–500 nm was synthesized using a surfactant (hexamethylenetetramine or ...polyvinylpyrrolidone) micelle solution in a hydrothermal process. The as-synthesized Gd(OH)3 nanomaterials were subsequently sintered to form gadolinium oxide (Gd2O3) nanorods. X-ray diffraction, transmission electron microscopy, ultraviolet spectroscopy, and Fourier-transform infrared spectroscopy were used to examine the microstructures, morphologies, and optical characteristics of the sintered products. The results suggest that this hydrothermal process may be an effective and convenient approach to prepare Gd(OH)3 and Gd2O3 with one-dimensional nanostructures. The photoluminescence spectra were studied at excitation wavelengths of 210 and 230 nm, and the samples exhibited emission peaks indicating room-temperature photoluminescence.
•Gd(OH)3 nanorods were prepared by hydrothermal synthesis.•GdCl3·6H2O and NH3·H2O used as reactants; HMT or PVP used in micelle solution.•Gd(OH)3 nanorods transformed to Gd2O3 nanorods after high-temperature sintering.•Gd(OH)3 nanorods exhibited room-temperature photoluminescence at λ < 510 nm.•All Gd2O3 nanorods exhibited emission band at about 393 nm.
It is accepted knowledge that inner functions and outer functions in complex analysis correspond, respectively, to all-pass filters and signals of minimum phase. The knowledge, however, has not been ...justified for general inner and outer functions. In digital signal processing the correspondence and related results are based on studies of rational functions. In this paper, based on the recent result on positivity of phase derivatives of inner functions, we establish the theoretical foundation for all-pass filters and signals of minimum phase. We, in particular, deal with infinite Blaschke products and general singular inner functions induced by singular measures. A number of results known for rational functions are generalized to general inner functions. Both the discrete and continuous signals cases are rigorously treated.
Radiotherapy performs an important function in the treatment of cancer, but resistance of tumor cells to radiation still remains a serious concern. More research on more effective radiosensitizers is ...urgently needed to overcome such resistance and thereby improve the treatment outcome. The goal of this study was to evaluate and compare the radiosensitizing efficacies of gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) on glioma at clinically relevant megavoltage energies. Both AuNPs and AgNPs potentiated the in vitro and in vivo antiglioma effects of radiation. AgNPs showed more powerful radiosensitizing ability than AuNPs at the same mass and molar concentrations, leading to a higher rate of apoptotic cell death. Furthermore, the combination of AgNPs with radiation significantly increased the levels of autophagy as compared with AuNPs plus radiation. These findings suggest the potential application of AgNPs as a highly effective nano-radiosensitizer for the treatment of glioma.
Crowd evacuation simulation using virtual reality (VR) is significant for digital emergency response construction. However, existing evacuation simulation studies suffer from poor adaptation to ...complex environments, inefficient evacuations, and poor simulation effects and do not fully consider the impacts of specific disaster environments on crowd evacuation. To more realistically express the crowd evacuation results obtained under the influence of fire environments and the subjective consciousness of pedestrians in subway stations, we designed a dynamic pedestrian evacuation path planning method under multiple constraints, analysed the influences of an 'environmental role' and a 'subjective initiative' on crowd evacuation, established an improved social force model (ISFM)-based crowd evacuation simulation method in VR, developed a prototype system and conducted experimental analyses. The experimental results show that the crowd evacuation time of the ISFM is affected by the disaster severity. In simulation experiments without disaster scenarios, the improved model's crowd evacuation efficiency improved by averages of 12.53% and 15.37% over the commercial Pathfinder software and the original social force model, respectively. The method described herein can effectively support real-time VR crowd evacuation simulation under multiexit and multifloor conditions and can provide technical support for emergency evacuation learning and management decision analyses involving subway fires.
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