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1.
Langmuir ; 39(13): 4777-4788, 2023 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-36947690

RESUMEN

Metal-directed interfacial self-assembly of well-defined coordination polymer (CP) ultrathin films can control the metal complex arrangement and distribution at the molecular level, providing a convenient route for the design and fabrication of novel opto-electrical devices and heterogeneous catalysts. Here, we report the assembly of two series of CP multilayers with the transition-metal ions of Fe2+, Co2+, Zn2+ and Tb3+ as connectors and tripodal terpyridyl ligands of 4,4',4″-(1,3,5-triazine-2,4,6-triyl)tris(1-(4-([2,2':6',2″-terpyridin]-4'-yl)benzyl)pyridin-1-ium) (TerPyTa) and 4,4',4″-(benzene-1,3,5-triyl)tris(1-(4-([2,2':6',2″-terpyridin]-4'-yl)benzyl)pyridin-1-ium) (TerPyBen) as linkers at the air-water interface. The as-prepared Langmuir-Blodgett (LB) films display strong luminescence, with the emission wavelength and relative intensity dependent on both the metal ions and linkers; among them, the Zn-TerPyTa and Zn-TerPyBen CPs give off the strongest luminescent emission centered at about 370 nm with an emission lifetime of approximately 0.2-0.3 ns. The Tb-TerPyTa CPs can give off emission at approximately 490, 546, 586, and 622 nm, attributed to the 5D4 to 7F3-6 electron transitions of typical Tb3+ ions. Finally, these CP LB films can act as efficient heterogeneous photocatalysts for the CO2 reduction to selectively produce CO. The catalytic efficiency can be optimized by adjusting the experimental conditions (light sensitizer, electron donor, and water content) and CP composition (metal ion and ligand) with an excellent yield of up to 248.1 mmol g-1. In particular, it is revealed that, under the same conditions, the catalytic efficiency of the Fe-TerPyTa CP LB film is nearly 2 to 3 orders of magnitude higher than that of the other metalated complexes investigated in the homogeneous system. UV-vis spectroscopy and cyclic voltammetry studies demonstrated that the dual active sites of Fe-terpyridine and TerPyTa units contribute to the enhanced catalytic activity. This work provides an effective method to introduce the earth-abundant metal complexes into CP films to construct efficient noble-metal-free photocatalysts for the CO2 reduction.

3.
Front Pediatr ; 10: 980179, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36304527

RESUMEN

Objective: This study aimed to determine the influence of fluid overload on bronchopulmonary dysplasia (BPD) in very low-birth-weight infants (VLBWI) within 1 week after birth. Methods: This was a retrospective case control study conducted in the Jingzhou Central Hospital. The clinical data of VLBWI (with a birth weight [BW] < 1,500 g and 26 weeks ≤ gestational age [GA] < 32 weeks) who were admitted to the neonatal intensive care unit of this hospital from January 2016 to December 2021 were analyzed retrospectively. A total of 157 cases were enrolled and divided into a BPD group (n = 60) and a non-BPD group (n = 97) according to whether BPD was present. The general condition, fluid intake, and fluid overload of the two groups of neonates within 1 week after birth were compared. The logistic regression was used to assess the association between infant characteristics and BPD. The ROC curve was used to assess how well the 7 day cumulative fluid overload predicted BPD, and to identify an optimal cut off for prediction. Results: The comparison of the patients' general condition revealed that the neonates in the BPD group had a younger GA, lower BW, lower 5-min Apgar score, longer duration of invasive mechanical ventilation, and higher incidence of intrauterine infections and administration of surfactants (P < 0.05). The differences in the other indicators were not statistically significant between the two groups. The logistic regression analysis revealed that a younger GA, the presence of intrauterine infection, and a 7-day cumulative fluid overload were the risk factors for the development of BPD. A ROC curve was plotted with the 7-day cumulative fluid overload as the test variable and BPD as the status variable. The area under the curve was 0.75 (95% confidence interval: 0.664-0.826, P = 0.042), with a sensitivity of 76.7% and a specificity of 70.1%, corresponding to a 7-day cumulative fluid overload of 36.2%. Conclusion: A younger GA, the presence of intrauterine infection, and a 7-day cumulative fluid overload were risk factors for the development of BPD. A 7 day cumulative fluid overload threshold of 36.2% best predicted the development of BPD.

4.
Ophthalmol Sci ; 2(3): 100180, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36245759

RESUMEN

Objective: We aimed to develop a deep learning (DL)-based algorithm for early glaucoma detection based on color fundus photographs that provides information on defects in the retinal nerve fiber layer (RNFL) and its thickness from the mapping and translating relations of spectral domain OCT (SD-OCT) thickness maps. Design: Developing and evaluating an artificial intelligence detection tool. Subjects: Pretraining paired data of color fundus photographs and SD-OCT images from 189 healthy participants and 371 patients with early glaucoma were used. Methods: The variational autoencoder (VAE) network training architecture was used for training, and the correlation between the fundus photographs and RNFL thickness distribution was determined through the deep neural network. The reference standard was defined as a vertical cup-to-disc ratio of ≥0.7, other typical changes in glaucomatous optic neuropathy, and RNFL defects. Convergence indicates that the VAE has learned a distribution that would enable us to produce corresponding synthetic OCT scans. Main Outcome Measures: Similarly to wide-field OCT scanning, the proposed model can extract the results of RNFL thickness analysis. The structural similarity index measure (SSIM) and peak signal-to-noise ratio (PSNR) were used to assess signal strength and the similarity in the structure of the color fundus images converted to an RNFL thickness distribution model. The differences between the model-generated images and original images were quantified. Results: We developed and validated a novel DL-based algorithm to extract thickness information from the color space of fundus images similarly to that from OCT images and to use this information to regenerate RNFL thickness distribution images. The generated thickness map was sufficient for clinical glaucoma detection, and the generated images were similar to ground truth (PSNR: 19.31 decibels; SSIM: 0.44). The inference results were similar to the OCT-generated original images in terms of the ability to predict RNFL thickness distribution. Conclusions: The proposed technique may aid clinicians in early glaucoma detection, especially when only color fundus photographs are available.

5.
World J Clin Cases ; 10(28): 10317-10325, 2022 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-36246798

RESUMEN

BACKGROUND: Malignant peritoneal mesothelioma (MPM) is an extremely rare tumor with nonspecific clinical manifestations, which is extremely difficult to diagnose. Herein, we reported a case of MPM in the abdominal cavity with massive short-term ascites as the first symptom. CASE SUMMARY: A 65-year-old woman presented to the hospital with abdominal pain, distention, and shortness of breath that persisted for 15 d. The serum CA-125 level was 1075 U/mL. The abdominal computed tomography showed massive ascites and no obvious tumor lesions. The pathological examination of the ascitic fluid showed numerous heterotypic cells with some papillary structures. The immunohistochemistry and fluorescence in situ hybridization showed the deletion of CDX2 (-), WT-1 (-), Ki-67 (about 10% +), CEA (-), Glut-1 (+++), desmin (-), PD-L1 (-), and CDKN2A (P16). The final diagnosis was MPM. The patient refused tumor cytoreductive surgery and received two cycles of cisplatin plus pemetrexed bidirectional chemotherapy. In the second cycle, she received an additional cycle of hyperthermic intraperitoneal chemotherapy and immune checkpoint inhibitor therapy due to massive recalcitrant ascites. She died of disease progression 2 mo after diagnosis. CONCLUSION: In case of massive unexplained ascites, the possibility of MPM should not be excluded to avoid misdiagnosis and delay in treatment.

7.
J Insect Sci ; 21(5)2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34581410

RESUMEN

RNAi is an effective tool for gene function analysis and a promising strategy to provide environmentally friendly control approaches for pathogens and pests. Recent studies support the utility of bacterium-mediated RNAi as a cost-effective method for gene function study and a suitable externally applied delivery mechanism for pest control. Here, we developed a bacterium-mediated RNAi system in Spodoptera frugiperda based on four target genes, specifically, Chitinase (Sf-CHI), Chitin synthase B (Sf-CHSB), Sugar transporter SWEET1 (Sf-ST), and Hemolin (Sf-HEM). RNAi conducted by feeding larvae with bacteria expressing dsRNAs of target genes or injecting pupae and adults with bacterially synthesized dsRNA induced silencing of target genes and resulted in significant negative effects on growth and survival of S. frugiperda. However, RNAi efficiency and effects were variable among different target genes and dsRNA delivery methods. Injection of pupae with dsCHI and dsCHSB induced a significant increase in wing malformation in adults, suggesting that precise regulation of chitin digestion and synthesis is crucial during wing formation. Injection of female moths with dsHEM resulted in lower mating, fecundity, and egg hatching, signifying a critical role of Sf-HEM in the process of egg production and/or embryo development. Our collective results demonstrate that bacterium-mediated RNAi presents an alternative technique for gene function study in S. frugiperda and a potentially effective strategy for control of this pest, and that Sf-CHI, Sf-CHSB, Sf-ST, and Sf-HEM encoding genes can be potent targets.


Asunto(s)
Interferencia de ARN , ARN Bicatenario/farmacología , Spodoptera , Animales , Bacterias/genética , Quitinasas/efectos de los fármacos , Quitinasas/genética , Fertilidad/efectos de los fármacos , Genes de Insecto/efectos de los fármacos , Inmunoglobulinas/efectos de los fármacos , Inmunoglobulinas/genética , Proteínas de Insectos/efectos de los fármacos , Proteínas de Insectos/genética , Larva/efectos de los fármacos , Larva/genética , Larva/fisiología , Control Biológico de Vectores , Pupa/efectos de los fármacos , Pupa/genética , Pupa/fisiología , Reproducción/efectos de los fármacos , Spodoptera/efectos de los fármacos , Spodoptera/genética , Spodoptera/fisiología
8.
Insects ; 12(8)2021 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-34442259

RESUMEN

Investigation of mating-induced trade-offs between reproduction and survival is conducive to provide evolutionary insights into reproductive strategies and aging. Here, we used RNAseq and bioinformatics to reveal mating-induced changes of genes and pathways related to reproduction and survival in female Cephalcia chuxiongica, a pine defoliator with facultative parthenogenesis and long larval dormancy. Results showed that mating induced substantial downregulation on genes and pathways associated to immunity, stress response, and longevity. However, mating induced divergent reproductive response, with downregulation on genes and pathways related to egg production while upregulation on genes and pathways related to egg fertilization. Considering the nature of limited resources in adults, low fecundity, and egg protection behavior in C. chuxiongica, we suggest that mating triggers trade-offs between reproduction and survival in this insect and females of this species may have evolved specific strategies to adapt to the environmental and hosts' conditions, e.g., restrict whole fecundity to ensure higher fertilization and offspring's survival. Moreover, mating induced significant responses on genes and pathways that play important roles in vertebrate reproduction while their function in insects are unclear, such as the progesterone-mediated oocyte maturation pathway; the significant regulation after mating suggests that their function may be evolutionarily conserved in animal kingdom.

9.
Medicine (Baltimore) ; 100(20): e25969, 2021 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-34011080

RESUMEN

INTRODUCTION: Transvaginal natural orifice transluminal endoscopic surgery (vNOTES) is an emerging technique in the area of minimally invasive surgery. Vaginal leiomyoma is a rare benign tumor, with only a few cases being reported in the literature. we demonstrate a novel approach for excision of a vaginal leiomyoma via vNOTES. To ensure reproducibility and replicability akin to a standardized procedure, we have provided a step-by-step video description of the use of vNOTES for upper anterior vaginal myomectomy. PATIENT CONCERNS: A 35-year-old female (G2P0A2) presented with a tumor in the upper anterior vaginal wall, which gradually increased in size. DIAGNOSIS: A vaginal examination revealed a swollen area approximately 3-cm in diameter on the upper anterior vaginal wall. The swelling was mobile and solid. All other vitals were normal. Transvaginal ultrasound detected a 3.0 × 3.4 cm hypoechogenic mass on the superior vaginal wall, and a preoperative diagnosis of the vaginal tumor was confirmed. INTERVENTIONS: The upper vaginal leiomyoma treated using transvaginal natural orifice transluminal endoscopic surgery. OUTCOMES: The procedure lasted for 20 min, and the postoperative course was uneventful. CONCLUSIONS: vNOTES can be a promising alternative to traditional vaginal surgery for upper vaginal disease due to advantages such as excellent exposure, easy access and precise suturing. However, more studies are needed to assess its long-term efficacy.


Asunto(s)
Leiomioma/cirugía , Cirugía Endoscópica por Orificios Naturales/métodos , Miomectomía Uterina/métodos , Neoplasias Vaginales/cirugía , Adulto , Femenino , Humanos , Leiomioma/diagnóstico , Leiomioma/patología , Resultado del Tratamiento , Ultrasonografía , Vagina/diagnóstico por imagen , Vagina/patología , Vagina/cirugía , Neoplasias Vaginales/diagnóstico , Neoplasias Vaginales/patología
10.
Mitochondrial DNA B Resour ; 5(3): 3638-3639, 2020 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-33367040

RESUMEN

The black-winged fly, Felderimyia fuscipennis (Diptera: Tephritidae), is an insect pest of bamboo shoot, mainly distributed in Thailand, Malaysia and Yunnan Province and Guangxi Autonomous Region, China. The complete sequence of the mitogenome of F. fuscipennis has been determined in this study. The whole mitogenome sequence is 16,536 bp in length, which totally contains 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and a non-coding region (putative control region, CR). The phylogeny indicates that F. fuscipennis of subfamily Trypetinae was monophyletic and clearly separated from both Dacinae and Tephritinae with high bootstrap value supported.

11.
J Synchrotron Radiat ; 27(Pt 3): 753-761, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32381778

RESUMEN

Anaerobic ammonium-oxidizing (anammox) bacteria play a key role in the global nitrogen cycle and in nitrogenous wastewater treatment. The anammox bacteria ultrastructure is unique and distinctly different from that of other prokaryotic cells. The morphological structure of an organism is related to its function; however, research on the ultrastructure of intact anammox bacteria is lacking. In this study, in situ three-dimensional nondestructive ultrastructure imaging of a whole anammox cell was performed using synchrotron soft X-ray tomography (SXT) and the total variation-based simultaneous algebraic reconstruction technique (TV-SART). Statistical and quantitative analyses of the intact anammox bacteria were performed. High soft X-ray absorption composition inside anammoxosome was detected and verified to be relevant to iron-binding protein. On this basis, the shape adaptation of the anammox bacteria response to iron was explored.


Asunto(s)
Compuestos de Amonio/metabolismo , Bacterias/metabolismo , Bacterias/ultraestructura , Imagenología Tridimensional/métodos , Algoritmos , Anaerobiosis , Gránulos Citoplasmáticos/ultraestructura , Procesamiento de Imagen Asistido por Computador , Hibridación Fluorescente in Situ , Espectrometría de Masas , Microscopía Confocal , Oxidación-Reducción , Programas Informáticos , Sincrotrones
12.
Ying Yong Sheng Tai Xue Bao ; 31(1): 249-258, 2020 Jan.
Artículo en Chino | MEDLINE | ID: mdl-31957402

RESUMEN

Stellera chamaejasme is one of the most serious weeds in Qinhai-Tibetan Plateau, the rapid expansion of which exerts an increasing effect on the alpine meadow ecosystem. With high-throughput sequencing technology, geostatistics and GIS method, the spatial heterogeneity of soil fungal diversity in Stellera occurrence area and the spatial correlation between Stellera coverage and soil fungal diversity were investigated in a typical degraded alpine meadow of the Qilian Mountain. Compared to no-Stellera area, the fungi richness in Stellera area decreased, the dominance increased, and the α-diversity reduced. The difference of fungal species composition enhanced and ß-diversity significantly increased. The spatial pattern of soil fungal diversity was affected by the invasion of Stellera, resulting in higher fragmentation in occurrence area. Spatial heterogeneity of species composition increased remarkably, and spatial stability of α-diversity and ß-diversity decreased. The portion of positive correlation and negative correlation interlaced, indicating no clear spatial correlation between Stellera coverage and soil fungal diversity. Our results indicate that the spatial pattern of soil fungal diversity was affected by the interaction of soil and vegetation in Stellera invaded meadows.


Asunto(s)
Suelo , Thymelaeaceae , Ecosistema , Hongos , Pradera , Microbiología del Suelo
13.
Mitochondrial DNA B Resour ; 5(3): 2828-2829, 2020 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33457965

RESUMEN

The melon fly, Zeugodacus cucurbitae (Diptera:Tephritidae) is an important invasive pest and distributed throughout tropical, subtropical countries and areas. In this study, we report the complete mitochondrial genome of the fly with 15, 685 base pair in length, which includes 37 genes (the large and small ribosomal RNA subunits, 22 transfer RNA genes, 13 genes encoding mitochondrial proteins) and a non-coding A + T-rich control region. Molecular phylogeny indicated that there was a high bootstrap value supported among Z. cucurbitae and Z. tau belonging to the Z. tau complex.

14.
World J Surg Oncol ; 17(1): 106, 2019 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-31208415

RESUMEN

BACKGROUND: To retrospectively analyze the tumor resection method used in 20 patients with clavicular tumors and evaluate its clinical efficacy. METHODS: A total of 9 patients with clavicular benign tumors underwent intracapsular resection, and 11 patients with clavicular malignant tumors underwent tumor resection from May 2012 to May 2017. Of the 11 patients, 5 underwent clavicular reconstruction using the plate-cement complex. Surgical efficacy was assessed using the Musculoskeletal Tumor Society, Constant-Murley, and American Shoulder and Elbow Surgeons shoulder outcome scores preoperatively until 12 months postoperatively. RESULTS: The average duration of follow-up care was 33.7 (12-71) months. Of the 20 patients, 3 patients died, 3 survived with tumor recurrence or metastasis, and 14 survived with no tumor recurrence. Among the 5 patients who underwent resection of malignant clavicular tumors and reconstruction, 2 underwent a re-operation because of a loose screw and plate displacement. In the functional assessment of the shoulder joint, patients with benign and malignant clavicular tumors showed significantly higher scores postoperatively compared with preoperative scores. For malignant clavicular tumors, no significant improvement was observed when comparing the non-reconstruction and reconstruction groups. CONCLUSIONS: Surgery is an optimal treatment for clavicular tumors. In patients with benign clavicular tumors, simple intracapsular resection can achieve a satisfactory prognosis. Reconstruction of a clavicular defect after resection of a clavicular malignant tumor is not recommended.


Asunto(s)
Neoplasias Óseas/cirugía , Clavícula/cirugía , Recurrencia Local de Neoplasia/cirugía , Adolescente , Adulto , Neoplasias Óseas/patología , Niño , Preescolar , Clavícula/patología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia , Adulto Joven
15.
J Insect Sci ; 19(3)2019 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-31115473

RESUMEN

Recent studies on polyandry evolution have revolutionized our understanding of sexual selection. Therefore, study on traits in females, such as sensory perception and remating strategies, is expected to disclose a greater role of sexual selection in female evolution. Here, we tested how bodyweights of both sexes affected female and male remating behavior in Spodoptera litura (Fabricius, 1775) (Lepidoptera: Noctuidae). Results show most (74.4%; unmated virgin females may be sexually immature) females and males mated the first time in the second scotophase after eclosion. In the subsequent scotophase, 41.9% once-mated females and 94.1% once-mated males mated the second time with a novel virgin mate. Analyses indicate that female remating probability significantly increased with the increase of her own and the second male's bodyweight but decreased with the increase of the first male's bodyweight, while bodyweights of both sexes have no significant effect on male remating probability. Considering the nature of the low level of polyandry (two times on average) and last male precedence in S. litura, we propose that 1) females are more choosy when remating, from which females will benefit indirectly by sequential mate comparison and remate to replace sperm from the previous mates with those from higher quality mates, and 2) males will generally like to remate with any possible females, from which males will gain direct benefit by siring more offspring. The outcome of polyandry rate is likely to be the result of male investment × female choice interactions.


Asunto(s)
Peso Corporal , Conducta Sexual Animal , Spodoptera/fisiología , Animales , Femenino , Masculino
17.
Mitochondrial DNA B Resour ; 4(2): 3838-3839, 2019 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-33366211

RESUMEN

Carpomya vesuviana (Diptera: Tephritidae), commonly known as the ber fruit fly, is the most destructive insect pest of 'ber' (jujube) throughout Asia and Western Europe. Complete sequence of the mitogenome of C. vesuviana has been determined in this study. The circular genome is 15,267 bp long and contains a standard gene complement, that is, the large and small ribosomal RNA subunits, 22 transfer RNA genes, 13 genes encoding mitochondrial proteins, and a non-coding A + T-rich control region. The phylogeny showed that C. vesuviana of subfamily Trypetinae was monophyletic and clearly separated from both Dacinae and Tephritinae with maximum support (p = 1).

18.
Mitochondrial DNA B Resour ; 5(1): 106-107, 2019 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-33366443

RESUMEN

Acrotaeniostola dissimilis (Diptera: Tephritidae) is an insect pest of bamboo shoot and distributed in the Yunnan and Sichuan Provinces, Southwest China. Complete mitogenome sequence has been determined in this study. The circular genome is 15384 bp long and contains a standard gene complement, that is, the large and small ribosomal RNA subunits, 22 transfer RNA genes, 13 genes encoding mitochondrial proteins, and a non-coding A + T-rich control region. The phylogeny showed that A. dissimilis in tribe Gastrozonini was a monophyletic branch and clearly separated from both tribe Dacini and tribe Ceratitidini with high bootstrap value supported.

19.
Math Biosci Eng ; 17(2): 1593-1603, 2019 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-32233597

RESUMEN

Long non-coding RNAs (lncRNAs) consist of over 200 nucleotides and are not translated into proteins. Previous studies have shown the importance of lncRNAs in the development of the lung adenocarcinoma (LUAD). Emergence of the high-throughput sequencing technology has led to the identification of a lot of lncRNAs which plays important roles in various biological events. Increasingly evidence has revealed that aberrant lncRNAs expression is related to the development of various cancers. We analyzed the RNA-seq data of 551 lung adenocarcinoma patients downloaded from The Cancer Genome Atlas (TCGA). By analyzing the pre-cancerous and cancer tissues of the relevant patient transcriptomes, we discovered the significant lncRNAs associated with the lung adenocarcinoma. Based on their median score, the prognosis of the patients was categorized as either poor or favorable. Univariate and multivariate COX analysis were used to further analyze the differential lncRNAs. Co-expression and gene enrichment analysis were performed to further investigate the function of the related lncRNA. RNA-seq data analysis led to the discovery of the lncRNA, OGFRP1 as an interesting factor involved in the lung adenocarcinoma. Therefore, lncRNAs play an important role in the clinical diagnosis and the treatment of the lung adenocarcinoma.


Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , ARN Largo no Codificante , Adenocarcinoma del Pulmón/genética , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/genética , ARN Largo no Codificante/genética , Transcriptoma
20.
Ying Yong Sheng Tai Xue Bao ; 29(9): 2835-2842, 2018 Sep.
Artículo en Chino | MEDLINE | ID: mdl-30411558

RESUMEN

Rapid and accurate estimation of soil nutrient content based on hyperspectral data is an optimal method for the monitoring of soil nutrient and inversion of soil physical and chemical characters. The relationship between soil nutrient content and spectral reflectance was analyzed with soil samples being collected from the loess hilly-gully region of northern Shaanxi Province. The prediction models of the content of soil organic matter, total nitrogen, total phosphorus and total potassium were constructed by the combination of three techniques, including partial least squares (PLS), multiple linear regression (MLR), and support vector machine (SVM). Then, the optimal model was selected by comparison analysis. The results showed good correlations between the content of soil nutrients and spectral reflectance in visible region (400-760 nm) and near infrared region (760-1100 nm). The maximum values of correlation coefficient located in both spectral regions. The SPA-SVM model had the best applicability and highest inversion accuracy for the contents of all soil nutrients, with simple and efficient modeling process. Our results provided a reference for applying machine learning algorithm in the construction of hyperspectral prediction model of soil nutrient content in the loess hilly-gully region.


Asunto(s)
Monitoreo del Ambiente/métodos , Modelos Estadísticos , Suelo/química , China , Análisis de los Mínimos Cuadrados , Nitrógeno/análisis , Nutrientes , Fósforo/análisis
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