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In this study, we proposed a bifunctional sensor of high sensitivity and slow light based on carbon nanotubes (CNTs). An array of left semicircular ring (LSR), right semicircular ring (RSR), and circular ring (CR) resonators are utilized to form the proposed metamaterial. The proposed structure can achieve double plasmon-induced transparency (PIT) effects under the excitation of a TM-polarization wave. The double PIT originated from the destructive interference between two bright modes and a dark mode. A coupled harmonic oscillator model is used to describe the destructive interference between the two bright modes and a dark mode, and the simulation results agree well with the calculated results. Moreover, we investigate the influence of the coupling distance, period, and flare angle on the PIT spectra. The relationship between the resonant frequencies, full width at half maximum (FWHM), amplitudes, quality factors (Q), and the coupling distance is also studied. Finally, a high sensitivity of 1.02 THz RIU-1 is obtained, and the transmission performance can be maintained at a good level when the incident angle is less than 40°. Thus, the sensor can cope with situations where electromagnetic waves are not perpendicular to the structure's surface. The maximum figure of merit (FOM) can reach about 8.26 RIU-1; to verify the slow light property of the device, the slow light performance of the proposed structure is investigated, and a maximum time delay (TD) of 22.26 ps is obtained. The proposed CNT-based metamaterial can be used in electromagnetically induced transparency applications, such as sensors, optical memory devices, and flexible terahertz functional devices.
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Watershed management needs more information on ecological function and services in large regions. Spatial units are particularly important for the watershed management. Zoning of aquatic ecosystem functional management region refers to the zoning of terrestrial ecosystems as per the characteristics of aquatic ecosystems, providing an ecological background and basic spatial units for water environment management in basins. Although basin water environment management based on aquatic ecosystem functional management region and control unit is highly effective in practice, the current need for refined management of water environments cannot be met by existing zoning schemes of aquatic ecosystem functional management regions and control units. In response to the need to protect basin water environments, which is raised in the 14th Five-Year plan, a zoning method of aquatic ecosystem functional management fourth-level region for basins is proposed in this study. It features an effective integration of aquatic ecosystem functional management regions and control units and township-level administrative divisions, thus contributing to the implementation of a basin water environment management system that fulfils the zoning, grading, classification and period goals of aquatic ecosystem functional management. In this way, it can satisfy the business application of administrative management and refined management of water environments, which features coupling terrestrial and aquatic ecosystems and unification of water resources, water environments and aquatic ecology. The feasibility and effectiveness of the proposed zoning method were verified by using the Daqing River Basin, Beijing-Tianjin-Hebei region, China, as a case study. The results were accepted by the Ministry of Ecology and Environment and the Haihe River Water Conservancy Commission of the Ministry of Water Resources, which can provide scientific rationale and technical support for the accurate and differentiated watershed water environments management and ecological restoration of coastal wetlands in the Haihe River Basin based on aquatic ecosystem functional management fourth-level region with clear responsibility for the local government during the period of the 14th Five-Year plan.
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Ecosistema , Ríos , Monitoreo del Ambiente/métodos , China , Agua , Conservación de los Recursos NaturalesRESUMEN
Recently, computational thinking (CT) has gained importance in education systems worldwide, specifically the CT training of pre-service teachers. This study conducted a systematic literature analysis (2011-2021) of 38 works on pre-service teachers' CT based on Web of Science, Science Direct, and Google Scholar databases. The results were as follows: (1) Six training methods were found, (2) CT training effectively improved pre-service teachers' CT, (3) A positive relationship was found between pre-service teachers' CT ability and the five factors affecting the ability, (4) A mode of training to improve CT ability of pre-service teachers and the relationship between CT ability and teaching methods were considered. This study suggested ideas for designing training modules of CT ability and a reference for realizing the best training effect. Finally, future research trends and a general model of training were presented as references for researchers, instructors, and policy makers to promote the CT of pre-service teachers.
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Interesting coherence and correlations appear between superpositions of two bosonic modes when the modes are parametrically coupled to a third intermediate mode and are also coupled to external modes which are in thermal states of unequal mean photon numbers. Under such conditions, it is found that one of linear superpositions of the modes, which is effectively decoupled from the other modes, can be perfectly coherent with the other orthogonal superposition of the modes and can simultaneously exhibit anticoherence with the intermediate mode, which can give rise to entanglement between the modes. It is shown that the coherence effects have a substantial effect on the population distribution between the modes, which may result in lowering the population of the intermediate mode. This shows that the system can be employed to cool modes to lower temperatures. Furthermore, for appropriate thermal photon numbers and coupling strengths between the modes, it is found that entanglement between the directly coupled superposition and the intermediate modes may occur in a less restricted range of the number of the thermal photons such that the modes could be strongly entangled, even at large numbers of the thermal photons.
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A coherent feedback scheme is used to enhance the degree of squeezing of the output field in a cavity optomechanical system. In the feedback loop, a beam splitter (BS) plays the roles of both a feedback controller and an input-output port. To realize effective enhancement, the output quadrature should take the same form as the input quadrature, and the system should operate at the deamplification situation in the meantime. This can be realized by choosing an appropriate frequency-dependent phase angle for the generalized quadrature. Additionally, both the transmissivity of the BS and the phase factor induced by time delays in the loop affect optical squeezing. For the fixed frequency, the optimal values of transmissivity and phase factor can be used to achieve the enhanced optical squeezing. The effect of optical losses on squeezing is also discussed. Optical squeezing is degraded by the introduced vacuum noise owing to the inefficient transmission in the loop. We show that the enhancement of squeezing is achievable with the parameters of the current experiments.
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This study systematically searched CNKI and Web of Science(WoS) for the research papers on the toxicity of Tripterygium wilfordii included from database inception to August 31, 2021, and visually displayed the authors, research institutions, keywords, and other contents using bibliometrics and CiteSpace 5.8.3. Furthermore, the current situation and research progress on T. wilfordii safety were also analyzed based on information extraction to find the research hotspot, evolution path, and development trend, and to provide references for future research. A total of 1 876 Chinese papers and 243 English papers were included in the study. The analysis of authors showed that WANG Qi and ZHANG Luyong had the most publications in Chinese and English papers, respectively. According to the analysis of research institutions, National Institutes for Food and Drug Control and China Pharmaceutical University possessed the largest number of Chinese and English papers, respectively, but there was less cooperation between them. The analysis of keywords in Chinese and English papers showed that the research contents of the safety of T. wilfordii mainly focused on clinical monitoring, mechanism, dosage form improvement, quality standard, component analysis, monomer research, efficiency and toxicity reduction, etc. Metabonomics, tripterine, and the underlying mechanism of toxicity were the research hotspots in the future. At present, the research on the toxicity of T. wilfordii is still under development. It is necessary to highlight the in-depth research and strengthen the inter-group and inter-region cooperation of authors or institutions to provide references for the research on the toxicity of T. wilfordii.
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Medicamentos Herbarios Chinos , Tripterygium , Bibliometría , China , Medicamentos Herbarios Chinos/toxicidad , HumanosRESUMEN
The ultra-field infrared and visible image registration is a challenging task due to its nonlinear imaging and multi-modal image features. In this paper, a robust registration method is proposed for the ultra-field infrared and visible images. First, control points are extracted utilizing phase congruency and optimized based on the guidance map, which is proposed according to significant structures information. Second, ROI pair matching is accomplished based on epipolar curve. Its effect is equivalent to a search window that is popular in methods with the standard field of view, and it can overcome the content differences in the search window caused by nonlinear imaging and vision disparity. Third, a descriptor, named multiple phase congruency directional pattern (MPCDP), is established and composed of distribution information and main direction. The phase congruency amplitudes are encoded as binary patterns, and then they are represented as weighted histogram for distribution information. Six pairs of ultra-field infrared and visible images are employed for registration experiments, and the results demonstrate that the performance of the proposed is robust and accurate in five types of ultra-field scenes and two different camera relationships.
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We investigate the force measurement sensitivity in a squeezed dissipative optomechanics within the free-mass regime under the influence of shot noise (SN) from the photon number fluctuations, laser phase noise from the pump laser, thermal noise from the environment, and optical losses from outcoupling and detection inefficiencies. Generally, squeezed light could generate a reduced SN on the squeezed quadrature and an enlarged quantum backaction noise (QBA) due to the antisqueezed conjugate quadrature. With an appropriate choice of phase angle in homodyne detection, QBA is cancellable, leading to an exponentially improved measurement sensitivity for the SN-dominated regime. By now, the effects of laser phase noise that is proportional to laser power emerge. The balance between squeezed SN and phase noise can lead to an sub-SQL sensitivity at an exponentially lower input power. However, the improvement by squeezing is limited by optical losses because high sensitivity is delicate and easily destroyed by optical losses.
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Alzheimer's disease (AD) is the most common cause of dementia among older people in worldwide. miR-29c-3p was reported to play a role in AD development. However, the detail function of miR-29c-3p in AD remains unclear. The aim of this research is to analyze the functional mechanism of miR-29c-3p in AD. The RNA levels of miR-29c-3p and Tumor necrosis factor-α-inducible protein-1 (TNFAIP1) were detected by Quantitative real time polymerase chain (qRT-PCR) reaction. Western blot assay was carried out to examine the protein levels of TNFAIP1, Bax, B-cell lymphoma-2 (Bcl-2), Cleaved caspase 3, and Nuclear factor-k-gene binding (NF-κB). The interaction between miR-29c-3p and TNFAIP1 was predicted by online tool TargrtScan and verified using the dual luciferase reporter assay and RNA immunoprecipitation RIP (RIP) assay. Besides, cell proliferation and apoptosis rate were determined by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry analysis, respectively. Aß treatment decreased miR-29c-3p expression and increased TNFAIP1 expression. Overexpression of miR-29c-3p mitigated the effects of Aß on proliferation and apoptosis. Similarly, knockdown of TNFAIP1 also reversed the effects of Aß on cell progression. Interestingly, miR-29c-3p suppressed the expression of TNFAIP1 via binding to 3'UTR of TNFAIP1 mRNA. As expected, overexpression of TNFAIP1 reversed the effects of miR-29c-3p on Aß-mediated cell progression. Besides, we also confirmed that miR-29c-3p affected Aß-mediated cell progression by regulating TNFAIP1/NF-κB signaling pathway. In conclusion, our findings confirmed that miR-29c-3p attenuated Aß-induced neurotoxicity through regulation of NF-κB signaling pathway by directly targeting TNFAIP1, providing the potential value for the treatment of AD patients.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Apoptosis/fisiología , Supervivencia Celular/fisiología , MicroARNs/metabolismo , Subunidad p50 de NF-kappa B/metabolismo , Transducción de Señal/fisiología , Proteínas Adaptadoras Transductoras de Señales/genética , Péptidos beta-Amiloides/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Regulación hacia Abajo , Humanos , MicroARNs/genética , Fragmentos de Péptidos/farmacología , Regulación hacia ArribaRESUMEN
We developed a convenient technique to detect Herpesviral haematopoietic necrosis attributed to cyprinid herpes virus 2 (CyHV-2), a serious disease of Crucian carp and goldfish related to high mortality. In the present study, we employed a lateral flow dipstick (LAMP-LFD) to present a loop-mediated isothermal amplification assay. The specificity was ascertained via other six viruses, and the sensitivity was compared using PCR method, which are the reaction conditions changes for the method improved. The results revealed that CyHV-2 performance was observable at 64 °C in a separated tube within 60 min, when the samples hybridized using an FITC-labeled probe. As the LAMP-LFD method's specificity was high, with its sensitivity identical to that of traditional PCR, the overall DNA collected revealed the lowest detection limit of 0.18 pg/µl from goldfish diseased by CyHV-2. In summary, the development of LAMP-LFD's method does not require expensive instruments, and it can be regarded as a fast, simple, and reliable method for CyHV-2 detection.
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Herpesviridae/genética , Herpesviridae/aislamiento & purificación , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Reología/métodos , Animales , Cyprinidae/virología , Enfermedades de los Peces/virología , Sensibilidad y EspecificidadRESUMEN
We discuss the generation of strong stationary mechanical squeezing and entanglement in the modulated two-and three-mode optomechanics. Following the reservoir engineering scheme, the beam-splitter and parametric optomechanical interactions can be simultaneously achieved through appropriately choosing the modulation frequency on mechanical motion, which is essential to strong squeezing and entanglement. In the two-mode modulated optomechanics, squeezing is tunable by the relative ratio of parametric and beam-splitter couplings, and also robust to thermal noise due to the simultaneously optically induced cooling process. In the three-mode modulated optomechanics, strong EPR-type entanglement is also attainable, which can surpass the 3dB limit of nondegenerate parametric interaction. However, the ideal entanglement is impossible since only one of mechanical Bogoliubov modes is cooled by the cavity mode, which also makes the entanglement fragile to the mechanical noise.
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Hexokinase (HXK, EC 2.7.1.1) is a multifunctional protein that both is involved in catalyzing the first step of glycolysis and plays an important role in sugar signaling. However, the supporting genetic evidence on hexokinases (CsHXKs) from grape (Vitis vinifera L. cv. Cabernet Sauvignon) berries has been lacking. Here, to investigate the role of CsHXK isoforms as glucose (Glc) and abscisic acid (ABA) sensors, we cloned two hexokinase isozymes, CsHXK1 and CsHXK2 with highly conserved genomic structure of nine exons and eight introns. We also found adenosine phosphate binding, substrate recognition and connection sites in their putative proteins. During grape berry development, the expression profiles of two CsHXK isoforms, sucrose synthases (SuSys) and cell wall invertase (CWINV) genes increased concomitantly with high levels of endogenous Glc and ABA. Furthermore, we showed that in wild type grape berry calli (WT), glucose repressed the expression levels of sucrose synthase (SuSy) and cell wall invertase (CWINV) genes, while ABA increased their expression levels. ABA could not only effectively improve the expression levels of SuSy and CWINV, but also block the repression induced by glucose on the expression of both genes. However, after silencing CsHXK1 or CsHXK2 in grape calli, SuSy and CWINV expression were enhanced, and the expressions of the two genes are insensitive in response to Glc treatment. Interestingly, exogenous ABA alone could not or less increase SuSy and CWINV expression in silencing CsHXK1 or CsHXK2 grape calli compared to WT. Meantime, ABA could not block the repression induced by glucose on the expression of SuSy and CWINV in CsHXK1 or CsHXK2 mutants. Therefore, Glc signal transduction depends on the regulation of CsHXK1 or CsHXK2. ABA signal was also disturbed by CsHXK1 or CsHXK2 silencing. The present results provide new insights into the regulatory role of Glc and ABA on the enzymes related to sugar metabolism in grape berry.
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Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Glucosiltransferasas/metabolismo , Hexoquinasa/metabolismo , Proteínas de Plantas/metabolismo , Vitis/enzimología , beta-Fructofuranosidasa/metabolismo , Ácido Abscísico/farmacología , Secuencia de Aminoácidos , Pared Celular/enzimología , Frutas/enzimología , Frutas/metabolismo , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Glucosa/farmacología , Glucosiltransferasas/genética , Hexoquinasa/genética , Modelos Moleculares , Filogenia , Proteínas de Plantas/genética , Conformación Proteica , beta-Fructofuranosidasa/genéticaRESUMEN
A vegetation study was conducted to investigate the interactive effects of perfluoroalkyl substances (PFASs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), and Cadmium (Cd) on soil enzyme activities, phytotoxicity and bioaccumulation of wheat (Triticum aestivum L.) and rapeseed (Brassica campestris L.) from co-contaminated soil. Soil urease activities were inhibited significantly but catalase activities were promoted significantly by interaction of PFASs and Cd which had few effects on sucrase activities. Joint stress with PFASs and Cd decreased the biomass of plants and chlorophyll (Chl) content in both wheat and rapeseed, and malondialdehyde (MDA) content, superoxide dismutase (SOD) and peroxidase (POD) activities were increased in wheat but inhibited in rapeseed compared with single treatments. The bioconcentration abilities of PFASs in wheat and rapeseed were decreased, and the translocation factor of PFASs was decreased in wheat but increased in rapeseed with Cd addition. The bioaccumulation and translocation abilities of Cd were increased significantly in both wheat and rapeseed with PFASs addition. These findings suggested important evidence that the co-existence of PFASs and Cd reduced the bioavailability of PFASs while enhanced the bioavailability of Cd in soil, which increased the associated environmental risk for Cd but decreased for PFASs.
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Ácidos Alcanesulfónicos/toxicidad , Brassica rapa/efectos de los fármacos , Cadmio/toxicidad , Caprilatos/toxicidad , Fluorocarburos/toxicidad , Triticum/efectos de los fármacos , Ácidos Alcanesulfónicos/metabolismo , Ácidos Alcanesulfónicos/farmacocinética , Biomasa , Cadmio/farmacocinética , Caprilatos/farmacocinética , Clorofila/farmacología , Interacciones Farmacológicas , Contaminación Ambiental/análisis , Fluorocarburos/farmacocinética , Malondialdehído/metabolismo , Suelo/química , Contaminantes del Suelo/toxicidad , Superóxido Dismutasa/metabolismoRESUMEN
The cinchona alkaloid-catalyzed [4 + 2] cyclocondensation of α,ß-unsaturated acyl chlorides with imines is developed to give the corresponding substituted dihydropyridinones in good yields with high to excellent enantioselectivities. Reduction of the dihydropyridinones gave highly optically active substituted tetrahydropyridinone and piperidine derivatives.
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Alcaloides de Cinchona/química , Dihidropiridinas/síntesis química , Hidrocarburos Clorados/química , Iminas/química , Piperidinas/síntesis química , Piridonas/síntesis química , Catálisis , Ciclización , Dihidropiridinas/química , Estructura Molecular , Piperidinas/química , Piridonas/química , EstereoisomerismoRESUMEN
The Fengfeng mining area is an important coal-producing area in China and crucial environmental problems have been caused by large-scale exploitation of coal mines. The spatio-temporal evolution and driving factors of the ecological environment quality in this area must be explored for promoting the transformation of coal-based cities. Based on Landsat data of the Google earth engine ï¼GEEï¼ platform, this study constructed a new remote sensing-based ecological index ï¼RSEInewï¼ for the Fengfeng mining area from 2000 to 2020. The spatial and temporal evolution of RSEInew and its driving factors were evaluated by using trend analysis and geographic detector methods. The results showed thatï¼ â From 2000 to 2020, the RSEInew of the Fengfeng mining area presented a fluctuating increasing trend ï¼trend = 0.002 2ï¼, and the proportion of good and excellent ecological environmental quality showed an increasing trend, rising from 24.80% in 2000 to 65.54% in 2020. â¡ The change in the RSEInew grade indicated that the proportion of significant improvement ï¼3 and 4ï¼ of ecological environment quality grade in the Fengfeng Mining area from 2000 to 2020 was 10.21%, which was mainly distributed in Hexun town and Yijing town in the northwest of the Fengfeng mining area. The proportion of significant degradation ï¼-3 and -4ï¼ was only 1.58%, mainly scattered in Linshui town and Dashe town. ⢠RSEInew values increased significantly during 2000-2020 in the area accounting for 18.29%, mainly distributed in the central and northern areas and the western fringe of the Fengfeng mining area. The significantly reduced area accounted for 9.25%, mainly concentrated in the eastern area of the Fengfeng mining area. The coefficient of variation results showed that the areas with high fluctuation of RSEInew were mainly concentrated in Pengcheng town and Linshui town in the middle and eastern Fengfeng mining area. ⣠From the perspective of influencing factors, the average q value of land use type ï¼X6ï¼ during 2000-2020 was 0.290, which was much higher than other factors. The q value of social and economic factors showed an increasing trend, indicating that the spatial distribution of ecological environment quality in this region was increasingly strongly influenced by human activities. The interaction results showed that land use change was the key factor influencing ecological environment quality in the Fengfeng mining area.
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AIM: To explore the effects of tibial osteotomy varus angle combined with posterior tibial slope (PTS) on the stress of polyethylene liner in total knee arthroplasty (TKA) by building finite element model (FEM). METHODS: Established the FEM of standard TKA with tibial osteotomy varus angle 0° to 9° were established and divided into 10 groups. Next, each group was created 10 FEMs with 0° to 9° PTS separately. Calculated the stress on polyethylene liner in each group in Abaqus. Finally, the relevancy between tibial osteotomy angle and polyethylene liner stress was statistically analyzed using multiple regression analysis. RESULTS: As the varus angle increased, the area of maximum stress gradually shifted medially on the polyethylene liner. As the PTS increases, the percentage of surface contact forces on the medial and lateral compartmental of the polyethylene liner gradually converge to the same. When the varus angle is between 0° and 3°, the maximum stress of the medial compartmental surfaces of polyethylene liner rises smoothly with the increase of the PTS. When the varus angle is between 4° and 9°, as the increase of the PTS, the maximum stress of polyethylene liner rises first and then falls, forming a trough at PTS 5° and then rises again. Compared to the PTS, the varus angle has a large effect on the maximum stress of the polyethylene liner (p < .001). CONCLUSION: When the varus angle is 0° to 3°, PTS 0° is recommended, which will result in a more equalized stress distribution of the polyethylene liner in TKA.
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Artroplastia de Reemplazo de Rodilla , Análisis de Elementos Finitos , Prótesis de la Rodilla , Osteotomía , Polietileno , Estrés Mecánico , Tibia , Humanos , Artroplastia de Reemplazo de Rodilla/métodos , Osteotomía/métodos , Tibia/cirugía , Diseño de PrótesisRESUMEN
In this paper, we use the InVEST model and five periods of land use data from 1980 to 2020 to assess the habitat quality of the Ningxia Hui Autonomous Region in Western China, which has characteristics of a typical fragile ecosystem. We further analyse the spatial and temporal characteristics of habitat quality evolution and its relationship with land use and landscape pattern indices to explore the close relationship between regional habitat quality changes and human natural resource conservation and utilization. The research results show that the overall habitat quality of Ningxia Hui Autonomous Region was stable and at a moderate level (0.57-0.60) during the 40 years from 1980 to 2020; Habitat patches (2020) with low (24.89%), high (22.45%) and very high (29.81%) quality occupy a larger proportion of the area, followed by very low (13.31%) and moderate levels (9.54%). Over the past 40 years, there have been 275 sample sites in Ningxia where habitat quality has deteriorated, 1593 sample sites where the habitat quality has remained stable, and 184 sample sites where the habitat quality has increased. From 1980 to 2020, the Mean Patch Area of landscape types in Ningxia decreased by 25.9 hm2. The Patch Density increased by 0.06 /hm2. The Largest Patch Index decreased by 15.69%. The Edge Density increased by 2.5 m/hm2. The Contagion Index decreased by 2.99%. The Area-Weighted Mean Patch Fractal Dimension remained basically unchanged (0.01). The Landscape Shape Index showed a trend of first increasing and then decreasing, increasing by 13.94. The Area-Weighted Mean Shape Index has been reduced by 9.45. The Shannon Diversity Index and Shannon Evenness Index both show an increasing trend, but the amplitude is relatively small, with 0.09 and 0.04, respectively. There was a significant spatial aggregation of high and low habitat quality in Ningxia, with high values usually distributed in the northern and southern areas with good natural conditions and low values distributed in areas with frequent human activities and poor natural conditions. The decrease in habitat quality in Ningxia was mainly due to the expansion of cultivated land and construction land, the increase in landscape fragmentation and the resulting decrease in connectivity. On the other hand, due to the implementation of ecological protection measures, such as the project of returning farmland to pasture and grass to forest, the quality of habitats in Ningxia increased. The conclusions of this study support the idea that the conservation of habitat quality in ecologically fragile areas should fully preserve the original natural habitats and reduce the interference of human activities to increase the habitat suitability of the landscape and the habitat connectivity between patches. At the same time, targeted ecological protection policies should be developed to restore the areas where the habitat quality has been damaged and ultimately maintain the stability of biodiversity and ecosystems in ecologically fragile areas. Meanwhile, for ecologically fragile areas with similar ecological characteristics to those of Ningxia, our research supports the idea of increasing the protection of the stability of the original habitats, increasing the proportion of ecological restoration projects, financial investment and seeking cooperation with local community managers and residents will help to improve the quality of the regional habitats and the enrichment of the biodiversity, and ultimately promote the harmonious coexistence of human beings and nature in the modernized sense of the word.
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To assess the impact of human activities on regional nitrogen ï¼Nï¼ flow, based on the statistical data of 27 cities in the Yangtze River Delta Region ï¼YRDï¼, N flow characteristics of the agricultural production and consumption system ï¼APCï¼ in the YRD from 2011 to 2020 were analyzed using substance flow analysis, and driving factors for N flow were analyzed using scenario analysis. The results showed that from 2011 to 2020, the mean N input intensity of the APC in the YRD was 194.6 kg·ï¼hm2·aï¼-1, which was more than five times the national average valueï¼ thus, the YRD was a hotspot of N input intensity in China. Chemical N fertilizer was the largest component of N input, and the YRD changed from a net export area of grain and animal products to a net import area due to the rapid growth of food consumption demand. The N output of the system was mainly N loss to the environment, accounting for 53.2% on average. The N use efficiency ï¼NUEï¼ of cropland and the N recycling ratio of the APC ranged from 38.7-42.2% and 15.8-21.5%, respectively, which were both at a low level. In addition, the total amount of N input and output of the APC both showed a parabolic decline trend, decreasing by 11.3% and 10.0%, respectively. Spatially, the overall N input intensity showed a pattern of "high in the north and low in the south," and the spatial heterogeneity of N input intensity among cities was significant. Cities with high input intensity were mainly located in the north and east of Jiangsu, Shanghai, and northeast of Zhejiang. A significant positive spatial autocorrelation of the distribution of mean N input intensity was observed. The uncertainty of N flows was estimated using the error propagation equation. The uncertainty interval of N input and output ranged from 4.5% to 34.6%, which was roughly equivalent to the results of related studies, indicating that the model results were reliable. Based on the scenario analysis method, the decrease of the livestock scale led to a decrease of -0.27%-7.53% in the N input, making it the main reason for the decrease of total N input in the APC. Improving the NUE of cropland and re-establishing the linkage between cropland and livestock will help reduce N loss to the environment.
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Productos Agrícolas , Fertilizantes , Nitrógeno , Ríos , China , Nitrógeno/análisis , Productos Agrícolas/crecimiento & desarrollo , Agricultura/métodos , Monitoreo del AmbienteRESUMEN
Unregulated regional integrated development disrupts the reactive nitrogen (Nr) cycle, adding complexity to anthropogenic Nr environmental losses. The objective of this study was to establish a framework for mitigating anthropogenic Nr loss through a new regional integration perspective by analyzing anthropogenic Nr loss and integrated control strategies in the Yangtze River Delta (YRD) region from 2011 to 2020. The results revealed that the total Nr loss in the YRD ranged from 1780.7 to 1972.0 Gg N yr-1. Re-linking cropland and livestock is crucial for reducing Nr loss, as they act as the main sources of Nr loss. Spatial analysis at the regional scale revealed that regional integration has led to a dispersion of Nr loss, while uneven development among cities has resulted in a westward shift of 8.6 km in the Nr loss centroid, suggesting the need for the implementation of collaborative governance and integrated environmental regulation in the YRD. At the city scale, 27 cities were clustered into six types based on the similarity of Nr loss structural characteristics, allowing for the development of targeted reduction policies based on the specific Nr structural characteristics of each city. The results of driver and mitigation potential analysis indicated the feasibility of achieving the shared goal of sustainable regional integration and the application of optimal mitigation strategies in different cities and the YRD. Overall, the new-perspective framework established in this study provides valuable references for sustainable Nr management in the context of regional integration.
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Osteosarcoma (OS) is the most common primary malignant bone tumor. In the clinic, usual strategies for OS treatment include surgery, chemotherapy, and radiation. However, all of these therapies have complications that cannot be ignored. Therefore, the search for better OS treatments is urgent. Black phosphorus (BP), a rising star of 2D inorganic nanoparticles, has shown excellent results in OS therapy due to its outstanding photothermal, photodynamic, biodegradable and biocompatible properties. This review aims to present current advances in the use of BP nanoparticles in OS therapy, including the synthesis of BP nanoparticles, properties of BP nanoparticles, types of BP nanoparticles, and modification strategies for BP nanoparticles. In addition, we have discussed comprehensively the application of BP in OS therapy, including single, dual, and multimodal synergistic OS therapies, as well as studies about bone regeneration and antibacterial properties. Finally, we have summarized the conclusions, limitations and perspectives of BP nanoparticles for OS therapy.