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Maxillary protrusion combined with mandibular retraction is a highly prevalent but extremely complex maxillofacial deformity that can have a serious negative impact on patients' facial aesthetics and mental health. The traditional orthodontic treatment strategy often involves extracting 4 first premolars and conventional fixed techniques, combined with mini-implant screws, to retract the anterior teeth and improve facial protrusion. In recent years, an invisible orthodontic technique, without brackets, has become increasingly popular. However, while an invisible aligner has been used in some cases with reasonable results, there remain significant challenges in achieving a perfect outcome. This case report presents an adolescent patient with bimaxillary protrusion and mandibular retrognathia. Based on the characteristics of the invisible aligners and the growth characteristics of the adolescent's teeth and jawbone, we designed precise three-dimensional tooth movement and corresponding resistance/over-correction for each tooth, while utilizing the patient's jawbone growth potential to promote rapid development of the mandible, accurately and efficiently correcting bimaxillary protrusion and skeletal mandibular retrognathia. The patient's facial aesthetics, especially the lateral morphology, have been greatly improved, and various aesthetic indicators have also shown significant changes, and to the patient's great benefit, invasive mini-implant screws were not used during the treatment. This case highlights the advantages of using invisible aligners in adolescent maxillary protrusion combined with mandibular retraction patients. Furthermore, comprehensive and accurate design combined with good application of growth potential can also enable invisible orthodontic technology to achieve perfect treatment effects in tooth extractions, providing clinical guidance for orthodontists.
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Mandíbula , Adolescente , Humanos , Mandíbula/cirurgia , Maxila/cirurgia , Retrognatismo/cirurgia , Retrognatismo/terapia , Retrognatismo/diagnóstico por imagem , Técnicas de Movimentação Dentária/métodosRESUMO
PURPOSE: To assess the value of orthogonal axial images (OAI) of MRI in gastric cancer T staging. METHODS: This retrospective study enrolled 133 patients (median age, 63 [range, 24-85] years) with gastric adenocarcinoma who underwent both CT and MRI followed by surgery. MRI lacking or incorporating OAI and CT images were evaluated, respectively. Diagnostic performance (accuracy, sensitivity, and specificity) for each T stage, overall diagnostic accuracy and rates of over- and understaging were quantified employing pathological T stage as a reference standard. The McNemar's test was performed to compare the overall accuracy. RESULTS: Among patients with pT1-pT4 disease, MRI with OAI (accuracy: 88.7-94.7%, sensitivity: 66.7-93.0%, specificity: 91.5-100.0%) exhibited superior diagnostic performance compared to MRI without OAI (accuracy: 81.2-88.7%, sensitivity: 46.2-83.1%, specificity: 85.5-99.1%) and CT (accuracy: 88.0-92.5%, sensitivity: 53.3-90.1%, specificity: 88.7-98.1%). The overall accuracy of MRI with OAI was significantly higher (83.5%) than that of MRI without OAI (67.7%) (p < .001). However, there was no significant difference in the overall accuracy of MRI with OAI and CT (78.9%) (p = .35). The over- and understaging rates of MRI with OAI (12.0, 4.5%) were lower than those of MRI without OAI (21.8, 10.5%) and CT (12.8, 8.3%). CONCLUSION: OAI play a pivotal role in the T staging of gastric cancer. MRI incorporating OAI demonstrated commendable performance for gastric cancer T-staging, with a slight tendency toward its superiority over CT.
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Imageamento por Ressonância Magnética , Estadiamento de Neoplasias , Sensibilidade e Especificidade , Neoplasias Gástricas , Tomografia Computadorizada por Raios X , Humanos , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/patologia , Pessoa de Meia-Idade , Masculino , Feminino , Imageamento por Ressonância Magnética/métodos , Idoso , Adulto , Estudos Retrospectivos , Idoso de 80 Anos ou mais , Tomografia Computadorizada por Raios X/métodos , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/patologia , Meios de ContrasteRESUMO
This paper presents a detailed theoretical understanding of the noncovalent interactions between antibiotics tetracycline and conjugated microporous polymer (CMP), which is important to understand the recent experimental finding of efficient removal of antibiotics by CMP materials. We show that the co-work of π-π and H-π interactions determines the final equilibrium structures, when a tetracycline molecule spontaneously adsorbs to the surface or within the pores of the CMP network at physisorption distances. The binding energies for tetracycline/CMP systems are calculated to be -0.31 â¼ -1.15 eV, demonstrating the reliability of the adsorption. The electronic structures of CMP nanostructures remain basically undamaged upon the tetracycline adsorption. The replacement of benzothiadiazole unit with S and N heteroatoms to the phenyl moiety in the linker effectively enhanced the molecular polarity of CMP molecule and increases the interaction area between tetracycline and CMP network, consequently enhancing the average binding energies notably. Our calculations provide useful theoretical guidance for design of novel carbon-based porous adsorbents with good adsorption performance to remove residual tetracycline and other antibiotics in water.
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Antibacterianos , Tetraciclina , Adsorção , Reprodutibilidade dos Testes , Antibacterianos/química , Tetraciclina/química , Polímeros/químicaRESUMO
Hao DingBackground This study aimed to screen potential key genes associated with lipid metabolism and to evaluate their expressions and prognosis values in hepatocellular carcinoma (HCC). Methods Data sets GSE6764, GSE14520, and GSE112790 were used to identify the common differentially expressed genes (DEGs). Protein-protein interaction (PPI) network was constructed by STRING database. Hub genes in PPI network were identified and subjected to functional enrichment analysis to screen lipid metabolism-related genes. The expressions of selected genes and their associations with prognosis were analyzed using UALCAN, The Human Protein Atlas, and Kaplan-Meier plotter databases. The transcriptional factor (TF)-gene regulatory network was constructed using NetworkAnalyst. Results A total of 331 common DEGs including 106 upregulated and 225 downregulated genes were identified. PPI network analysis showed that 76 genes with high degrees were identified as hub genes, among which 14 genes were lipid metabolism-related genes. PON1, CYP2C9, and SPP1 were found to be the independent prognostic markers. Key TFs with close interactions with these prognostic genes, including HINFP, SRF, YY1, and NR3C1, were identified from the TF-gene regulatory network. Conclusion This study presented evidence for the prognostic capabilities of lipid metabolism-related genes in HCC, and newly identified HINFP and NR3C1 as potential biomarkers for HCC.
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Hepatocellular carcinoma (HCC) is the most common type of liver malignancy with high incidence and poor prognosis. Transmembrane protein 147 (TMEM147) has been implicated in the development of colon cancer. However, the role of TMEM147 in HCC remains unclear. In this study, data of 371 HCC tissues, 50 adjacent nontumor tissues, and 110 normal liver tissues were retrieved from the TCGA and GTEx databases. TMEM147 expression was found to be increased in HCC tissues. High expression of TMEM147 was related to poor prognosis, and TMEM147 was confirmed to be an independent prognostic factor for HCC patients. A receiver operating characteristics (ROC) analysis was performed and showed that the diagnostic efficacy of TMEM147 was significantly higher than that of AFP (0.908 versus 0.746, p < 0.001). Furthermore, TMEM147 promoted tumor immune infiltration, and macrophages were the immune cells that predominantly expressed TMEM147 in HCC. Further analysis revealed that TMEM147 mainly impacted the ribosome pathway, and CTCF, MLLT1, TGIF2, ZNF146, and ZNF580 were predicted to be the upstream transcription factors for TMEM147 in HCC. These results suggest that TMEM147 serves as a promising biomarker for diagnosis and prognosis and may potentially become a therapeutic target for HCC.
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Recently low-energy-gap benzoindenothiophene (BIT)-based organic dyes have been experimentally sensitized to dye-sensitized solar cells (DSSCs) with impressive 10.9% power conversion efficiency. This paper presents a computational study of the modification of BIT-based dyes with fused thiophene moieties to build novel low band gap sensitizers. Density functional theory (DFT), tight-binding DFT, and time dependent DFT (TDDFT) approaches are used to demonstrate the electronic and optical properties of the BIT dyes and dye/(TiO2)46 complexes. Our calculations show that the structural modification by using fused thiophenes can effectively lower the band gap of the BIT dyes by 0.07-0.12 eV and affect the optical properties of BIT dyes. Enlarging the thiophene unit in BIT with thienothiophene and dithienothiophene improves the oscillator strength by 14%-25%, while the lowest-energy absorption peak basically remains at 559 nm. The incorporation of cyclopentadithiophene unit leads to a significant 47 nm red-shift of absorption peak and a 25% enhanced oscillator strength, compared to the original BIT dye. Those fused thiophenes modified BIT dyes also demonstrate ideal molecular orbital distribution patterns and ultra-fast injection time at the dye/(TiO2)46 interface. Our calculations provide useful guidance for the molecular design of novel naphthalene-based dyes for DSSC optimizations.
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OBJECTIVE: All-trans retinoic acid (ATRA), a derivative of vitamin A, has been reported to exert its synergistic antitumor effect with chemotherapy in various cancer types; however, its effect in cervical cancer remains unclear. The objective of this study was to investigate the antitumor effect of ATRA with or without cisplatin and elucidate its potential mechanisms in cervical cancer cells. METHODS: Cell viability was determined by CCK-8 assay. Cell cycle and cell apoptosis were analyzed by flow cytometry. Caspase-3, cleaved caspase-3 and cell cycle-related proteins were detected by western blotting. Scratch wound-healing assay was performed to evaluate cell migration ability. The expression of CD44, a biomarker of cervical cancer stem-like cells, was determined by flow cytometry and western blotting. In addition, the activity of the Wnt signaling pathway was monitored by luciferase reporter assay and western blotting. RESULTS: Compared with cisplatin treatment alone, combined use of ATRA and cisplatin significantly inhibited cell proliferation (p<0.01) and migration (p<0.01), and induced G0/G1 phase arrest (p<0.01) and apoptosis (p<0.05) in cervical cancer Hela cells. Furthermore, ATRA treatment also effectively induced differentiation of cancer stem-like cells as represented by reduced expression of CD44 and inhibited Wnt signaling pathway activity. CONCLUSIONS: ATRA significantly enhanced the antitumor effect of cisplatin in cervical cancer cells, the mechanism of which might be attributed to its effect of inducing the differentiation of cancer stem-like cells.
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Células-Tronco Neoplásicas/metabolismo , Tretinoína/farmacologia , Neoplasias do Colo do Útero/metabolismo , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Sinergismo Farmacológico , Feminino , Células HeLa , Humanos , Células-Tronco Neoplásicas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Tretinoína/metabolismo , Neoplasias do Colo do Útero/genéticaRESUMO
This paper presents a computational study of the adsorptive desulfurization of small aromatic sulfur compounds by conjugated microporous polymers (CMPs). The density-functional tight-binding method augmented with an R-6 dispersion correction is employed to investigate the physisorption binding mechanism and electronic properties of the CMP-aromatic sulfur complexes. We show that the widely extended π conjugation in the CMP skeletons is favorable for the non-covalent adsorption of aromatic thiophene and dibenzothiophene via π-π, H-π, and S-π interactions. The average binding energies are calculated to be -6.2 â¼ -15.2 kcal/mol for CMP- thiophene/dibenzothiophene systems. For the dibenzothiophene molecule with larger size and more extended conjugation, it binds more than twice stronger to CMP than the thiophene molecule. We show that the replacement of quinoline unit to the phenylene group in the network linker effectively enhances the average binding capacities by around 0.8-1.8 kcal/mol. Our calculations theoretically demonstrate that CMPs materials are kind of promising candidates for the adsorptive desulfurization of small aromatic sulfur compounds. This paper provides useful theoretical guidance for design of novel carbon-based adsorbents for adsorptive desulfurization.
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Polímeros , Enxofre , Adsorção , Compostos de EnxofreRESUMO
Long noncoding RNA CRNDE (CRNDE) recently emerged as a carcinogenic promoter in various cancers including medulloblastoma. However, the functions and molecular mechanisms of CRNDE to the acquired drug resistance of medulloblastoma are still unclear. The transcript levels of CRNDE were examined in four medulloblastoma cell lines exposed to cisplatin treatment, and IC50 values were calculated. Effects of CRNDE knockdown or miR-29c-3p overexpression on cell viability, colony formation, apoptosis, migration, and invasion were assessed using the CCK-8, colony formation assay, flow cytometry, and Transwell assays, respectively. RNA pulldown and RNA-binding protein immunoprecipitation (RIP) were performed to confirm the molecular interactions between CRNDE and miR-29c-3p involved in medulloblastoma cells. The in vivo role of CRNDE knockdown or miR-29c-3p overexpression on tumor growth and apoptosis was evaluated in a xenograft mouse model of human medulloblastoma. The transcript levels of lncRNA CRNDE were significantly higher in cisplatin-treated tumor cells with higher IC50 values. Depletion of CRNDE inhibited tumor cell proliferation and colony formation, induced cell apoptosis, and suppressed migration and invasion in medulloblastoma cells. Moreover, overexpression of miR-29c-3p inhibited tumor cell proliferation and colony formation, migration, and invasion, and enhanced apoptosis and chemosensitivity to cisplatin. In addition, CRNDE was found to act as a miR-29c-3p sponge. Furthermore, in vivo experiments showed the CRNDE/miR-29c-3p interactions involved in medulloblastoma. Our study demonstrates that CRNDE acts as a critical mediator of proliferation, apoptosis, migration, invasion, and resistance to chemotherapeutics via binding to and negatively regulating miR-29c-3p in medulloblastoma cells. These results provide novel molecular targets for treatment of medulloblastoma.
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Neoplasias Cerebelares/genética , Resistencia a Medicamentos Antineoplásicos/genética , Meduloblastoma/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Neoplasias Cerebelares/tratamento farmacológico , Neoplasias Cerebelares/metabolismo , Cisplatino/farmacologia , Feminino , Humanos , Masculino , Meduloblastoma/tratamento farmacológico , Meduloblastoma/metabolismo , Camundongos , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJECTIVES: To determine the effect of NF-κB on cell proliferation and apoptosis, we investigate the expression of inflammation and apoptosis-related factors in the bovine mammary epithelial cell line, MAC-T. RESULTS: MAC-T cells were cultured in vitro and MTT and LDH assays used to determine the effects of lipopolysaccharide (LPS) on proliferation and cytotoxicity respectively. RT-PCR and western blotting were used to evaluate the effect of LPS and NF-κB inhibition [pyrrolidine dithiocarbamate (PDTC) treatment] on the expression of inflammation and apoptosis-related factors. LPS significantly inhibited MAC-T cell proliferation in a dose- and time-dependent manner. Furthermore, LPS promoted apoptosis while the NF-кB inhibitor PDTC attenuated this effect. After LPS treatment, the NF-кB signaling pathway was activated, and the expression of inflammation and apoptosis-related factors increased. When PDTC blocked NF-кB signaling, the expression of inflammation and apoptosis-related factors were decreased in MAC-T cells. CONCLUSIONS: LPS activates the TLR4/NF-κB signaling pathway, inhibits proliferation and promotes apoptosis in MAC-T cells. NF-кB inhibition attenuates MAC-T cell apoptosis and TLR4/NF-κB signaling pathway. NF-кB inhibitor alleviating MAC-T cell apoptosis is presumably modulated by NF-кB.
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Células Epiteliais/citologia , Lipopolissacarídeos/farmacologia , NF-kappa B/genética , NF-kappa B/metabolismo , Pirrolidinas/farmacologia , Tiocarbamatos/farmacologia , Acidose/genética , Acidose/metabolismo , Acidose/patologia , Animais , Apoptose/efeitos dos fármacos , Bovinos , Doenças dos Bovinos/genética , Doenças dos Bovinos/metabolismo , Doenças dos Bovinos/patologia , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacosRESUMO
Dexmedetomidine (DEX) has been hypothesized to possess anti-oxidative properties that may mitigate the damage caused by ischemia-reperfusion (IR) injury. The aim of the present study was to examine the effects of DEX on intestinal contractile activity, inflammation and apoptosis following intestinal IR injury. Intestinal IR injury was induced in rats by complete occlusion of the superior mesenteric artery for 60 min, followed by a 60-min reperfusion period. Rats received an intraperitoneal injection of 25 µg/kg DEX at 30 min prior to the mesenteric IR injury. Following reperfusion, segments of the terminal ileum were rapidly extracted and transferred into an isolated organ bath. The contractile responses to receptor-mediated acetylcholine (Ach) and non-receptor-mediated potassium chloride (KCl) were subsequently examined. Nitric oxide (NO) levels were determined and the expression levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, Bax and Bcl-2 were measured using an enzyme-linked immunosorbent assay. The levels of telomerase and caspase-3 were determined using reverse transcription-quantitative polymerase chain reaction. The results indicated that DEX treatment produced a significant reduction in the IR-induced contractile response to Ach and KCl in the intestinal tissue. Furthermore, DEX appeared to significantly ameliorate intestinal IR injury, in addition to reducing the production of NO. Similar reductions were observed in the intestinal expression levels of TNF-α and IL-6. In addition, DEX treatment resulted in a reduction in the expression levels of Bax in the intestinal tissues, while increasing those of Bcl-2, in addition to significantly increasing the mRNA levels of telomerase and caspase-3. Therefore, the present study indicated that NO, TNF-α and IL-6 may partially contribute to the pathogenesis of intestinal IR injury in addition to the increased expression levels of Bax, Bcl-2, telomerase and caspase-3. These findings suggest that DEX possesses beneficial anti-apoptotic and anti-inflammatory effects in intestinal tissue following bowel injury.
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BACKGROUND AND AIM: Previous studies have revealed significantly increased levels of plasma and mucosal homocysteine (Hcy) in patients with Crohn's disease (CD); however, whether Hcy is involved in intestinal fibrosis of CD remains unclear. This study aimed to investigate the effects of Hcy on intestinal fibrosis in TNBS/ethanol-induced colitis and to elucidate its potential mechanisms. METHODS: Sprague-Dawley rats were divided into 4 groups: normal control, normal + Hcy injection, TNBS model and TNBS model + Hcy injection. Hyperhomocysteinemia was induced by subcutaneous injection of Hcy. DAI, CMDI and HI were calculated to evaluate the severity of colitis. Masson trichrome staining was performed to assess the severity of fibrosis. The plasma and mucosal levels of Hcy were measured by HPLC-FD. The levels of IL-1ß, IL-6, TNF-α, TGF-ß1, CTGF, MMP-2,9 and collagen I, III in the colon were determined by ELISA, and the mRNA expressions of TGF-ß1, MMP-2,9 and TIMP-1 were detected by RT-PCR. RESULTS: Hcy was found to increase the scores of DAI, CMDI and HI; levels of IL-1ß, Il-6, TNF-α, TGF-ß1, CTGF, MMP-2,9 and collagen I, III; and mRNA expressions of TGF-ß1, MMP-2,9 and TIMP-1 in colonic tissue of rats with TNBS/ethanol-induced colitis. CONCLUSIONS: Hcy promotes intestinal fibrosis in rats with TNBS/ethanol-induced colitis, the underlying mechanisms of which may be attributed to its effects of increasing inflammatory damage, promoting the expression of profibrogenic cytokines and influencing MMPs/TIMPs balance.
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Colite/induzido quimicamente , Colo/patologia , Homocisteína , Hiper-Homocisteinemia/induzido quimicamente , Ácido Trinitrobenzenossulfônico , Animais , Colite/sangue , Colite/patologia , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Colo/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Etanol , Fibrose , Homocisteína/sangue , Hiper-Homocisteinemia/sangue , Hiper-Homocisteinemia/patologia , Mediadores da Inflamação/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Ratos Sprague-DawleyRESUMO
First-principles calculations based on density functional theory have been performed to explore the stable configurations, electronic structures, and vibrational spectra of neutral and charged silicon monoxide clusters (SiO)n((0,±)) (n = 2-7), which could be used as precursors in the synthesis of silicon nanowires. Our theoretical calculations provide new results on characteristic electron affinity, ionization potential, and vibrational spectroscopy, guiding future experiments in the synthesis of high-quality silicon nanowires. Specifically, as the number of SiO units n increases, IR spectra of (SiO)n(±) and Raman spectra of (SiO)n(-) show an evident blue shift, and Raman spectra of (SiO)n demonstrate a red shift. Moreover, most of the neutral silicon monoxide clusters have strong IR intensities and weak Raman activities, while most of the anionic counterparts have relatively weak IR intensities and strong Raman activities. Some other energetically competitive isomers of some (SiO)n((0,±)) species were also studied for comparison.
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We report possible cage-like nanostructures formed by a representative amino acid, serine octamers and decamers, determined by binding energy calculations and molecular dynamic simulations using the density functional tight-binding method. We used the l-handed serine to construct complex conformers linked by hydrogen bonds. We found the structures linked by -COOH···O=C- to be the most stable conformers and the calculation of the vibrational modes of complexes further illustrated this result. We attempted to apply our cage-like structures to the delivery of C(20) and cycloserine as model molecules. Our results may shed light on the design of cage-like biocompatible complexes for drug delivery.
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Portadores de Fármacos/química , Simulação de Dinâmica Molecular , Nanoestruturas/química , Serina/química , Ciclização , Dimerização , TermodinâmicaRESUMO
Monitoring grassland species and area real-timely and accurately is of great significance in species diversity research, as well as in sustainable development of ecosystem. Flowers have their own unique spectral characteristics. Compared with the nutrient stage, species are more easily identified by florescence. So, florescence is a critical period for identification. In the present paper, spectral differences among such flowers as Galium verum Linn., Hemerocallis citrina Baroni, Serratula centauroides Linn., Clematis hexapetala Pall., Lilium concolor var. pulchellum, Lilium pumilum and Artemisia frigida Willd. Sp. Pl. were found, along with identification methods, by analyzing canopies spectra and parametrizing characteristics. Verification results showed that when the coverage of flowers was greater than 10%, the accuracy of identification methods would be higher than 90%. On this basis, linear unmixing model was adopted to calculate the area of flowers in quadrates. Results showed that linear unmixing model was an effective method for estimating the coverage of flowers in grassland because the accuracy was about 4%.
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Flores/classificação , Pradaria , Tecnologia de Sensoriamento Remoto , Conservação dos Recursos Naturais , Modelos Lineares , Análise EspectralRESUMO
The distributing of China's grassland is abroad and the status of grassland degradation is in serious condition. So achieving real-time and exactly grassland ecological monitoring is significant for the carbon cycle, as well as for climate and on regional economies. With the field measured spectra data as data source, hyperspectral remote sensing monitoring of grassland degradation was researched in the present article. The warm meadow grassland in Hulunbeier was chosen as a study object. Reflectance spectra of leaves and pure canopies of some dominant grassland species such as Leymus chinensis, Stipa krylovii and Artemisia frigid, as well as reflectance spectra of mixed grass community were measured. Using effective spectral feature parametrization methods, the spectral feature of leaves and pure canopies were extracted, so the constructive species and degenerate indicator species can be exactly distinguished. Verification results showed that the accuracy of spectral identification was higher than 95%. Taking it as the foundation, the spectra of mixed grass community were unmixed using linear mixing models, and the proportion of all the components was calculated, and the errors were less than 5%. The research results of this article provided the evidence of hyperspectral remote sensing monitoring of grassland degradation.
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Monitoramento Ambiental/métodos , Pradaria , Tecnologia de Sensoriamento Remoto , China , Modelos Lineares , Poaceae , Análise EspectralRESUMO
Soil water content is a key parameter in monitoring drought. In recent years, a lot of work has been done on monitoring soil water content based on hyperspectral remotely sensed data both at home and abroad. In the present review, theories, advantages and disadvantages of the monitoring methods using different bands are introduced first. Then the unique advantages, as well as the problems, of the monitoring method with the aid of hyperspectral remote sensing are analyzed. In addition, the impact of soil water content on soil reflectance spectrum and the difference between values at different wavelengths are summarized. This review lists and summarizes the quantitative relationships between soil water content and soil reflectance obtained through analyzing the physical mechanism as well as through statistical way. The key points, advantages and disadvantages of each model are also analyzed and evaluated. Then, the problems in experimental study are pointed out, and the corresponding solutions are proposed. At the same time, the feasibility of removing vegetation effect is discussed, when monitoring soil water content using hyperspectral remote sensing. Finally, the future research trend is prospected.