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1.
Plant Phenomics ; 6: 0166, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38590393

RESUMEN

Quantifying the relationship between light and stands or individual trees is of great significance in understanding tree competition, improving forest productivity, and comprehending ecological processes. However, accurately depicting the spatiotemporal variability of light under complex forest structural conditions poses a challenge, especially for precise forest management decisions that require a quantitative study of the relationship between fine-scale individual tree structure and light. 3D RTMs (3-dimensional radiative transfer models), which accurately characterize the interaction between solar radiation and detailed forest scenes, provide a reliable means for depicting such relationships. This study employs a 3D RTM and LiDAR (light detection and ranging) data to characterize the light environment of larch plantations at a fine spatiotemporal scale, further investigating the relationship between absorbed photosynthetically active radiation (APAR) and forest structures. The impact of specific tree structural parameters, such as crown diameter, crown area, crown length, crown ratio, crown volume, tree height, leaf area index, and a distance parameter assessing tree competition, on the daily-scale cumulative APAR per tree was investigated using a partial least squares regression (PLSR) model. Furthermore, variable importance in projection (VIP) was also calculated from the PLSR. The results indicate that among the individual tree structure parameters, crown volume is the most important one in explaining individual tree APAR (VIP = 4.19), while the competition from surrounding trees still plays a role in explaining individual tree APAR to some extent (VIP = 0.15), and crown ratio contributes the least (VIP = 0.03). Regarding the spatial distribution of trees, the average cumulative APAR per tree of larch plots does not increase with an increase in canopy gap fraction. Tree density and average cumulative APAR per tree were fitted using a natural exponential equation, with a coefficient of determination (R2 = 0.89), and a small mean absolute percentage error (MAPE = 0.03). This study demonstrates the potential of combining 3D RTM with LiDAR data to quantify fine-scale APAR in plantations, providing insights for optimizing forest structure, enhancing forest quality, and implementing precise forest management practices, such as selective breeding for superior tree species.

2.
J Med Imaging (Bellingham) ; 11(1): 014008, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38379775

RESUMEN

Purpose: In recent years, the continuous advancement of convolutional neural networks (CNNs) has led to the widespread integration of deep neural networks as a mainstream approach in clinical diagnostic support. Particularly, the utilization of CNN-based medical image segmentation has delivered favorable outcomes for aiding clinical diagnosis. Within this realm, network architectures based on the U-shaped structure and incorporating skip connections, along with their diverse derivatives, have gained extensive utilization across various medical image segmentation tasks. Nonetheless, two primary challenges persist. First, certain organs or tissues present considerable complexity, substantial morphological variations, and size discrepancies, posing significant challenges for achieving highly accurate segmentation. Second, the predominant focus of current deep neural networks on single-resolution feature extraction limits the effective extraction of feature information from complex medical images, thereby contributing to information loss via continuous pooling operations and contextual information interaction constraints within the U-shaped structure. Approach: We proposed a five-layer pyramid segmentation network (PS5-Net), a multiscale segmentation network with diverse resolutions that is founded on the U-Net architecture. Initially, this network effectively leverages the distinct features of images at varying resolutions across different dimensions, departing from prior single-resolution feature extraction methods to adapt to intricate and variable segmentation scenarios. Subsequently, to comprehensively integrate feature information from diverse resolutions, a kernel selection module is proposed to assign weights to features across different dimensions, enhancing the fusion of feature information from various resolutions. Within the feature extraction network denoted as PS-UNet, we preserve the classical structure of the traditional U-Net while enhancing it through the incorporation of dilated convolutions. Results: PS5-Net attains a Dice score of 0.9613 for liver segmentation on the CHLISC dataset and 0.8587 on the ISIC2018 dataset for skin lesion segmentation. Comparative analysis with diverse medical image segmentation methodologies in recent years reveals that PS5-Net has achieved the highest scores and substantial advancements. Conclusions: PS5-Net effectively harnesses the rich semantic information available at different resolutions, facilitating a comprehensive and nuanced understanding of the input medical images. By capitalizing on global contextual connections, the network adeptly captures the intricate interplay of features and dependencies across the entire image, resulting in more accurate and robust segmentation outcomes. The experimental validation of PS5-Net underscores its superior performance in medical image segmentation tasks, offering promising prospects for enhancing diagnostic and analytical processes within clinical settings. These results highlight the potential of PS5-Net to significantly contribute to the advancement of medical imaging technologies and ultimately improve patient care through more precise and reliable image analysis.

3.
Nat Ecol Evol ; 7(11): 1790-1798, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37710041

RESUMEN

Vegetation 'greenness' characterized by spectral vegetation indices (VIs) is an integrative measure of vegetation leaf abundance, biochemical properties and pigment composition. Surprisingly, satellite observations reveal that several major VIs over the US Corn Belt are higher than those over the Amazon rainforest, despite the forests having a greater leaf area. This contradicting pattern underscores the pressing need to understand the underlying drivers and their impacts to prevent misinterpretations. Here we show that macroscale shadows cast by complex forest structures result in lower greenness measures compared with those cast by structurally simple and homogeneous crops. The shadow-induced contradictory pattern of VIs is inevitable because most Earth-observing satellites do not view the Earth in the solar direction and thus view shadows due to the sun-sensor geometry. The shadow impacts have important implications for the interpretation of VIs and solar-induced chlorophyll fluorescence as measures of global vegetation changes. For instance, a land-conversion process from forests to crops over the Amazon shows notable increases in VIs despite a decrease in leaf area. Our findings highlight the importance of considering shadow impacts to accurately interpret remotely sensed VIs and solar-induced chlorophyll fluorescence for assessing global vegetation and its changes.


Asunto(s)
Bosques , Bosque Lluvioso , Estaciones del Año , Sesgo , Clorofila
4.
J Ethnopharmacol ; 298: 115650, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-35988838

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Pinellia ternata tuber (PTT), the dried tuber of Pinellia ternata (Thunb.) Breit., has a long history of use in traditional Chinese medicine for drying dampness, resolving phlegm, down-bearing counterflow to check vomiting and dissipating masses. Modern pharmacology studies have revealed that PTT has diverse pharmacological effects such as antitussive and expectorant, anti-emetic, anti-tumor, and anti-inflammatory effect, etc. AIM OF THE REVIEW: This review aims to provide a critical and comprehensive evaluation on ethnopharmacological uses, chemical constituents, pharmacological and toxicological effects, analytical methods and quality control of PTT, which would provide scientific evidence for exploring future therapeutic, and formulating quality and safety criteria of PTT. MATERIALS AND METHODS: Pertinent information was systematically collected from several electronic scientific databases including Web of Science, Science Direct, PubMed, Elsevier, Wiley Online Library and China national knowledge infrastructure (CNKI), as well as the classic Chinese medical books. RESULTS: PTT is reported to be widely used traditionally for the treatment of cough, vomiting, infection, and inflammatory diseases in many southeast Asian countries. Phytochemical studies have revealed the presence of a total of 233 compounds belonging to alkaloids, nucleosides, organic acids, polysaccharides, volatile oils, amino acids, proteins, starches, etc. The extracts and components of PTT have possessed diverse pharmacological activities, such as antitussive, antiemetic, antitumor, antibacterial, and sedative-hypnotic activities. Raw P. ternata tuber (RPTT) with a pungent taste causes acrid irritation of the oral and laryngopharynx mucosa when taken by mistake, while its toxicity and side effects of RPTT can be dramatically reduced with proper processing. Three kinds of processed P. ternata tuber with different processing methods are available and traded in market, as well as applied in clinical treatments. Additionally, although raw or processed PTT have been recorded in several mainstream pharmacopoeias such as Chinese Pharmacopoeia, Japanese Pharmacopoeia, and Korean Pharmacopoeia, the quality items and requirements varies a lot. Therefore, a unified international standard of raw and processed PTT is urgent need to be done. CONCLUSIONS: The ethnopharmacological, phytochemical, pharmacological and toxicological and quality evaluation of PTT were highlighted in this review, which provides potential reference information to future investigate and commercially explore for pharmaceutical applications. Nevertheless, an efficient method for chemical profiling is still unavailable to find potent bioactive markers for quality control, and then comprehensive pharmacological effects and mechanisms and toxicological evaluation of PTT require further detailed research to ensure their quality and safety.


Asunto(s)
Antitusígenos , Pinellia , Etnofarmacología , Fitoquímicos/uso terapéutico , Fitoquímicos/toxicidad , Pinellia/química , Control de Calidad , Vómitos
5.
Materials (Basel) ; 15(4)2022 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-35207908

RESUMEN

Rare earth (RE) inclusions with high melting points as heterogeneous nucleation in liquid steel have stimulated many recent studies. Evaluating the potency of RE inclusions as heterogeneous nucleation sites of the primary phase is still a challenge. In this work, the edge-to-edge matching (E2EM) model was employed to calculate the atomic matching mismatch and predict the orientation relationship between La2O2S and γ-Fe from a crystallographic point of view. A rough orientation relationship (OR) was predicted with the minimum values of fr=9.43% and fd=20.72% as follows: [21¯1¯0]La2O2S∥[100]γ-Fe and (0003¯)La2O2S∥(002¯)γ-Fe. The interface energy and bonding characteristics between La2O2S and γ-Fe were calculated on the atomic scale based on a crystallographic study using the first-principles calculation method. The calculations of the interface energy showed that the S-terminated and La(S)-terminated interface structures were more stable. The results of difference charge density, electron localization function (ELF), the Bader charges and the partial density of states (PDOS) study indicated that the La(S)-terminated interface possessed metallic bonds and ionic bonds, and the S-terminated interface exhibited metallic bond and covalent bond characteristics. This work addressed the stability and the characteristics of the La2O2S/γ-Fe interface structure from the standpoint of crystallography and energetics, which provides an effective theoretical support to the study the heterogeneous nucleation mechanism. As a result, La2O2S particles are not an effective heterogeneous nucleation site for the γ-Fe matrix from crystallography and energetics points of view.

6.
Sensors (Basel) ; 21(13)2021 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-34283143

RESUMEN

Freehand exercises help improve physical fitness without any requirements for devices or places. Existing fitness assistant systems are typically restricted to wearable devices or exercising at specific positions, compromising the ubiquitous availability of freehand exercises. In this paper, we develop MobiFit, a contactless freehand exercise assistant using just one cellular signal receiver placed on the ground. MobiFit passively monitors the ubiquitous cellular signals sent by the base station, which frees users from the space constraints and deployment overheads and provides accurate repetition counting, exercise type recognition and workout quality assessment without any attachments to the human body. The design of MobiFit faces new challenges of the uncertainties not only on cellular signal payloads but also on signal propagations because the sender (base station) is beyond the control of MobiFit and located far away. To tackle these challenges, we conducted experimental studies to observe the received cellular signal sequence during freehand exercises. Based on the observations, we constructed the analytic model of the received signals. Guided by the insights derived from the analytic model, MobiFit segments out every repetition and rest interval from one exercise session through spectrogram analysis and extracts low-frequency features from each repetition for type recognition. Extensive experiments were conducted in both indoor and outdoor environments, which collected 22,960 exercise repetitions performed by ten volunteers over six months. The results confirm that MobiFit achieves high counting accuracy of 98.6%, high recognition accuracy of 94.1% and low repetition duration estimation error within 0.3 s. Besides, the experiments show that MobiFit works both indoors and outdoors and supports multiple users exercising together.


Asunto(s)
Ejercicio Físico , Dispositivos Electrónicos Vestibles , Terapia por Ejercicio , Humanos , Monitoreo Fisiológico , Descanso
7.
Ther Clin Risk Manag ; 14: 551-556, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29588594

RESUMEN

BACKGROUND: This study aimed to analyze the stage-situation depression and anxiety as well as independent influential factors in patients with postsurgical gastroparesis syndrome (PGS) and to provide dependent indications for treatment. PATIENTS AND METHODS: The self-rating depression scale (SDS) and self-rating anxiety scale (SAS) were used to test the depression and anxiety of 53 patients with PGS, who were treated in the Department of Gastroenterological Surgery of Gansu Provincial Hospital from January 2012 to October 2016. A comparison between the SDS or SAS scores of patients with PGS and without PGS was undertaken; then, we retrospectively analyzed the factors influencing depression and anxiety in PGS patients. RESULTS: The patients with PGS' mean scores of depression and anxiety were 49.92±11.37 and 50.91±6.57, respectively, which were higher than that of patients without PGS in the Chinese population (P<0.05). The results of multivariate logistic regression analysis indicated that the independent influential factors of depression and anxiety in patients with PGS included course of disease, pancreatic juice leakage, preoperative outflow tract obstruction, postoperative abdominal infection, and anastomotic complication (P<0.05). Patients with a disease course longer than 30 days; with pancreatic juice leakage; and who suffered from preoperative outflow tract obstruction, postoperative abdominal infection, and anastomotic complication had higher ratios of depression and anxiety. CONCLUSION: Depression and anxiety are clearly evident in patients with PGS, and we should pay attention to this phenomenon and provide appropriate treatment.

8.
Int J Clin Oncol ; 23(4): 659-670, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29344744

RESUMEN

BACKGROUND: Interleukin-1 alpha (IL-1α) plays an important role in tumorigenesis and angiogenesis of gastric cancer. The interleukin-1 receptor antagonist (IL-1RA) inhibits IL-1 selectively and specifically through IL-1R type I (IL-1RI). However, the underlying mechanism by which IL-1RA modulates the interactions of tumor cells and their micro-environment is poorly understood. We have evaluated the role of IL-1RA in the metastatic process as well as the mutual or reciprocal actions between gastric cancer cells and stromal cells. MATERIALS AND METHODS: The expressions of IL-1α, vascular endothelial growth factor (VEGF), and IL-1RI mRNA were determined by reverse transcriptase-PCR. The regulatory effect of IL-1RA on the secretion of VEGF in human gastric cancer cells and human umbilical vein endothelial cells (HUVECs) was detected by enzyme-linked immunosorbent assay. The effect of IL-1RA on metastatic potential was evaluated using proliferation, invasion, and angiogenesis assays, respectively, including in vitro co-culture system models consisting of tumor cells and stromal cells that were used to detect invasion and angiogenesis. RESULTS: Interleukin-1α mRNA was detected in the higher liver metastatic gastric cell line MKN45. IL-1α protein was expressed in MKN45 cells and in HUVECs. VEGF mRNA and protein were detected in the three gastric cancer cell lines (MKN4, NUGC-4, and AGS). Levels of VEGF secreted by gastric cancer cells and HUVECs appeared to be reduced through the action of IL-1RA via IL-1RI in a dose-dependent manner (P < 0.01). IL-1RA significantly inhibited the proliferation and migration of HUVECs (P < 0.01) and tube formation by HUVECs (P < 0.01), both in a dose-dependent manner. Compared with HUVECs grown without cancer cells (control) or with NUGC-4 cells, tube formation by HUVECs was significantly enhanced by co-culture with MKN45 cells (P < 0.01). The enhanced tube formation in the presence of MKN45 cells was inhibited by the addition of IL-1RA (P < 0.01). CONCLUSIONS: The IL-1RA downregulated the metastatic potential of gastric cancer through blockage of the IL-1α/VEGF signaling pathways. IL-1RA has the potential to play a role in the treatment of gastric cancer.


Asunto(s)
Proteína Antagonista del Receptor de Interleucina 1/administración & dosificación , Neovascularización Patológica/prevención & control , Receptores de Interleucina-1/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacos , Neoplasias Gástricas/tratamiento farmacológico , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Células Endoteliales de la Vena Umbilical Humana/patología , Humanos , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patología , Receptores de Interleucina-1/genética , Receptores de Interleucina-1/metabolismo , Neoplasias Gástricas/irrigación sanguínea , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patología
9.
Cancer Manag Res ; 9: 481-493, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29062241

RESUMEN

PURPOSE: This article investigates the relationship between cancer cells and stromal cells in carcinoma cell living microenvironment and elucidates the mechanism that interleukin-1 receptor antagonist (IL-1RA) blocks metastatic potential in colon cancer. METHODS: Western blot and RT-PCR assay were used to determine the expression of hepatocyte growth factor (HGF) and IL-1α in colon carcinoma cells and stromal cells. Effect of IL-1RA and HGF on metastatic potential of colon cancer cells were examined by proliferation, invasion, and angiogenesis assays. The interactional role of IL-1RA and HGF were detected by ELISA assay, invasion, and angiogenesis assay making up a co-culture system consisting of stromal and colon cancer cells in cells living microenvironment. RESULTS: IL-1α was expressed in human umbilical vein endothelial cells (HUVECs) and HT-29 and WiDr (colon cancer cell lines with higher liver metastatic potential). HGF was expressed only in fibroblast. HGF secretion from fibroblasts was significantly inhibited by IL-1RA (P<0.01). Furthermore, IL-1RA could significantly inhibit migration, proliferation, and angiogenesis of HUVECs (P<0.01). In the double co-culture system, there is a high liver metastatic potential of colon cancer cell line (HT-29) because it can secrete autocrine IL-1α, significantly enhanced angiogenesis compared with low liver metastatic cell line (CaCo-2) (P<0.01), which does not secrete IL-1α. On the contrary, blockage of autocrine IL-1α by IL-1RA might significantly decrease metastatic potential of colon carcinoma cells through downregulation of IL-1α/PI3K/NF-κB pathway. CONCLUSION: IL-1 receptor antagonist (IL-1RA) is an important inhibitor in metastatic process of colon carcinoma cell. Based on the above results, we suggest that IL-1RA may be a promising new therapeutic approach in inhibiting colon cancer with IL-1-producing patients.

10.
World J Gastroenterol ; 23(28): 5167-5178, 2017 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-28811711

RESUMEN

AIM: To investigate the underlying mechanism by which CXCL12 and CXCL6 influences the metastatic potential of colon cancer and internal relation of colon cancer and stromal cells. METHODS: Western blotting was used to detect the expression of CXCL12 and CXCL6 in colon cancer cells and stromal cells. The co-operative effects of CXCL12 and CXCL6 on proliferation and invasion of colon cancer cells and human umbilical vein endothelial cells (HUVECs) were determined by enzyme-linked immunosorbent assay, and proliferation and invasion assays. The angiogenesis of HUVECs through interaction with cancer cells and stromal cells was examined by angiogenesis assay. We eventually investigated activation of PI3K/Akt/mTOR signaling by CXCL12 involved in the metastatic process of colon cancer. RESULTS: CXCL12 was expressed in DLD-1 cancer cells and fibroblasts. The secretion level of CXCL6 by colon cancer cells and HUVECs were significantly promoted by fibroblasts derived from CXCL12. CXCL6 and CXCL2 could significantly enhance HUVEC proliferation and migration (P < 0.01). CXCL6 and CXCL2 enhanced angiogenesis by HUVECs when cultured with fibroblast cells and colon cancer cells (P < 0.01). CXCL12 also enhanced the invasion of colon cancer cells. Stromal cell-derived CXCL12 promoted the secretion level of CXCL6 and co-operatively promoted metastasis of colon carcinoma through activation of the PI3K/Akt/mTOR pathway. CONCLUSION: Fibroblast-derived CXCL12 enhanced the CXCL6 secretion of colon cancer cells, and both CXCL12 and CXCL6 co-operatively regulated the metastasis via the PI3K/Akt/mTOR signaling pathway. Blocking this pathway may be a potential anti-metastatic therapeutic target for patients with colon cancer.


Asunto(s)
Quimiocina CXCL12/metabolismo , Quimiocina CXCL6/metabolismo , Colon/citología , Neoplasias del Colon/patología , Neovascularización Patológica/patología , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Técnicas de Cocultivo , Colon/metabolismo , Ensayo de Inmunoadsorción Enzimática , Fibroblastos/metabolismo , Células Endoteliales de la Vena Umbilical Humana , Humanos , Invasividad Neoplásica/patología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Recombinantes/metabolismo , Transducción de Señal , Células del Estroma/metabolismo , Serina-Treonina Quinasas TOR/metabolismo
11.
Zhonghua Wei Chang Wai Ke Za Zhi ; 20(1): 84-89, 2017 Jan 25.
Artículo en Chino | MEDLINE | ID: mdl-28105626

RESUMEN

OBJECTIVE: To investigate the effects of polyunsaturated fatty acids (PUFA) ω-3 and ω-6, and their middle metabolites PGE2 and PGE3 on angiogenesis formation of gastric cancer, and to explore associated mechanism. METHODS: The effects of ω-3, ω-6, PGE2, PGE3 on the proliferation and migration of human umbilical vein endothelial cell (HUVEC) were measured by proliferation and migration assay respectively. The angiogenesis assay in vivo was used to measure the effects of ω-3, ω-6, PGE2 and PGE3 on neovascularization. In all the assays, groups without ω-3, ω-6, PGE2 and PGE3 were designed as the control. RESULTS: With the increased concentration of ω-6 from 1 µmol/L to 10 µmol/L, the proliferation ability of HUVECs enhanced, and the number of migration cells also increased from 28.2±3.0 to 32.8±2.1, which was higher than control group (21.2±3.2) respectively (both P<0.05). With the increased concentration of ω-3 from 1 µmol/L to 10 µmol/L, the proliferation ability of HUVECs was inhibited, and the number of migration cells decreased from 15.8±2.0 to 11.0±2.1, which was lower than control group (22.1±3.0) respectively (both P<0.05). In the angiogenesis assay, compared with control group (standard number: 43 721±4 654), the angiogenesis ability of HUVECs was significantly enhanced by ω-6 in concentration-dependent manner (1 µmol/L group: 63 238±4 795, 10 µmol/L group: 78 166±6 123, all P<0.01). Meanwhile, with the increased concentration of ω-3 from 1 µmol/L to 10 µmol/L, the angiogenesis ability was significantly decreased from 30 129±3 102 to 20 012±1 541(all P<0.01). The proliferation and migration ability of HUVECs were significantly promoted by ω-6 metabolites PGE2 (P<0.05) in a concentration-dependent manner. In contrast, ω-3 metabolites PGE3 significantly inhibited the proliferation and migration ability of HUVECs in a concentration-dependent manner (all P<0.05). After rofecoxib (a COX-2 specific inhibitor) inhibited the expression of COX-2, the expression level of PGE2 was significantly decreased in a dose-dependent manner. In co-culture system, whose gastric cancer cells expressed positive COX-2, ω-6 could increase angiogenesis of gastric cancer cells(P<0.01), but ω-3 could inhibit such angiogenesis(P<0.01). In co-culture system, whose gastric cancer cells did not express COX-2, ω-3 could inhibit the angiogenesis of gastric cancer cells (P<0.05), but ω-6 had no effect on angiogenesis. CONCLUSIONS: The PUFA ω-6 can enhance the angiogenesis via the promotion of proliferation and migration of HUVECs, and COX-2 and PGE2 may play an important role in this process, whereas, the ω-3 can inhibit the angiogenesis through its middle metabolites PGE3 to inhibit the proliferation and migration of HUVECs. Results of this experiment may provide a new approach to inhibit and prevent the spread of gastric cancer.


Asunto(s)
Alprostadil/análogos & derivados , Inductores de la Angiogénesis/farmacología , Línea Celular Tumoral/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Dinoprostona/farmacología , Ácidos Grasos Omega-3/farmacología , Ácidos Grasos Omega-6/farmacología , Ácidos Grasos Insaturados/farmacología , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Neovascularización Patológica/fisiopatología , Alprostadil/farmacología , Inductores de la Angiogénesis/metabolismo , Inhibidores de la Angiogénesis/farmacología , Recuento de Células/métodos , Línea Celular Tumoral/fisiología , Ensayos de Migración Celular , Técnicas de Cocultivo , Ciclooxigenasa 2/farmacología , Dinoprostona/metabolismo , Ácidos Grasos Omega-6/metabolismo , Células Endoteliales de la Vena Umbilical Humana/fisiología , Humanos , Lactonas/farmacología , Neoplasias Gástricas/fisiopatología , Sulfonas/farmacología
12.
Opt Express ; 23(6): 7694-702, 2015 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-25837107

RESUMEN

A novel method for registering imagery with Light Detection And Ranging (LiDAR) data is proposed. It is based on the phenomenon that the back-projection of LiDAR point cloud of an object should be located within the object boundary in the image. Using this inherent geometrical constraint, the registration parameters computation of both data sets only requires LiDAR point clouds of several objects and their corresponding boundaries in the image. The proposed registration method comprises of four steps: point clouds extraction, boundary extraction, back-projection computation and registration parameters computation. There are not any limitations on the geometrical and spectral properties of the object. So it is suitable not only for structured scenes with man-made objects but also for natural scenes. Moreover, the proposed method based on the inherent geometrical constraint can register two data sets derived from different parts of an object. It can be used to co-register TLS (Terrestrial Laser Scanning) LiDAR point cloud and UAV (Unmanned aerial vehicle) image, which are obtaining more attention in the forest survey application. Using initial registration parameters comparable to POS (position and orientation system) accuracy, the performed experiments validated the feasibility of the proposed registration method.

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