Research on the spatial temporary evolution of urban expansion in Xining city and its surrounding areas based on Landsat time series data.

Quantitative analysis of the process of urban expansion and evolution is of great practical significance for the future planning and development potential of valley cities. Based on GEE cloud platform and Landsat satellite data, this paper analyzed the spatio-temporal change characteristics and transfer rules of land cover in Xining City and its surrounding areas in the past 33 years by using random forest algorithm, spatio-temporal consistency test, land use dynamic attitude, transfer matrix and transfer hot spot analysis methods. The results show that the accuracy range of the preliminary classification of construction land is improved by 1.57%-3.53 % by using the spatio-temporal consistency test algorithm. The characteristics of land cover change in the study area are mainly the increase of construction land and forest area, the decrease of cultivated land and grassland area, the small change of water body and unused land, and the change of land cover type from cultivated land to urban construction land is prominent. The hot areas of construction land have gradually shifted from the central and eastern districts of the city in 1987 to the hot areas dominated by the Haihu New District of the West of the city, the Biological Park and the higher education base of the North District of the city, the South New District of the city, Duoba Town and the Ganhe Industrial Park in 2019.

Estimation and mapping of soil texture content based on unmanned aerial vehicle hyperspectral imaging.

Soil texture is one of the important physical and natural properties of soil. Much of the current research focuses on soil texture monitoring using non-imaging geophysical spectrometers. However there are fewer studies utilizing unmanned aerial vehicle (UAV) hyperspectral data for soil texture monitoring. UAV mounted hyperspectral cameras can be used for quickly and accurately obtaining high-resolution spatial information of soil texture. A foundation has been laid for the realization of rapid soil texture surveys using unmanned airborne hyperspectral data without field sampling. This study selected three typical farmland areas in Huangshui Basin of Qinghai as the study area, and a total of 296 soil samples were collected. Data calibration of UAV spectra using laboratory spectra and field in situ spectra to explore the feasibility of applying laboratory soil texture models directly to field conditions. This results show that UAV hyperspectral imagery combined with machine learning can obtain a set of ideal processing methods. The pre-processing of the spectral data can obtain high accuracy of soil texture estimation and good mapping effect. The results of this study can provide effective technical support and decision-making assistance for future agricultural land planning on the Tibetan Plateau. The main innovation of this study is to establish a set of processing procedures and methods applicable to UAV hyperspectral imagery to provide data reference for monitoring soil texture in agricultural fields on the Tibetan Plateau.

Scale Effect of Land Cover Classification from Multi-Resolution Satellite Remote Sensing Data.

Land cover data are important basic data for earth system science and other fields. Multi-source remote sensing images have become the main data source for land cover classification. There are still many uncertainties in the scale effect of image spatial resolution on land cover classification. Since it is difficult to obtain multiple spatial resolution remote sensing images of the same area at the same time, the main current method to study the scale effect of land cover classification is to use the same image resampled to different resolutions, however errors in the resampling process lead to uncertainty in the accuracy of land cover classification. To study the land cover classification scale effect of different spatial resolutions of multi-source remote sensing data, we selected 1 m and 4 m of GF-2, 6 m of SPOT-6, 10 m of Sentinel-2, and 30 m of Landsat-8 multi-sensor data, and explored the scale effect of image spatial resolution on land cover classification from two aspects of mixed image element decomposition and spatial heterogeneity. For the study area, we compared the classification obtained from GF-2, SPOT-6, Sentinel-2, and Landsat-8 images at different spatial resolutions based on GBDT and RF. The results show that (1) GF-2 and SPOT-6 had the best classification results, and the optimal scale based on this classification accuracy was 4-6 m; (2) the optimal scale based on linear decomposition depended on the study area; (3) the optimal scale of land cover was related to spatial heterogeneity, i.e., the more fragmented and complex was the space, the smaller the scale needed; and (4) the resampled images were not sensitive to scale and increased the uncertainty of the classification. These findings have implications for land cover classification and optimal scale selection, scale effects, and landscape ecology uncertainty studies.

Spatial Autocorrelation Analysis of Land Use and Ecosystem Service Value in the Huangshui River Basin at the Grid Scale.

The Huangshui River Basin is one of the most densely populated areas on the Qinghai-Tibet Plateau and is characterized by a high level of human activity. The contradiction between ecological protection and socioeconomic development has become increasingly prominent; determining how to achieve the balanced and coordinated development of the Huangshui River Basin is an important task. Thus, this study used the Google Earth Engine (GEE) cloud-computing platform and Sentinel-1/2 data, supplemented with an ALOS digital elevation model (ALOS DEM) and field survey data, and combined a remote sensing classification method, grid method, and ecosystem service value (ESV) evaluation method to study the spatial correlation and interaction between land use (LU) and ESV in the Huangshui River Basin. The following results were obtained: (1) on the GEE platform, Sentinel-1/2 active and passive remote sensing data, combined with the gradient tree-boosting algorithm, can efficiently produce highly accurate LU data with a spatial resolution of 10 m in the Huangshui River Basin; the overall accuracy (OA) reached 88%. (2) The total ESV in the Huangshui River Basin in 2020 was CNY 33.18 billion (USD 4867.2 million), of which woodland and grassland were the main contributors to ESV. In the Huangshui River Basin, the LU type, LU degree, and ESV have significant positive spatial correlations, with urban and agricultural areas showing an H-H agglomeration in terms of LU degree, with woodlands, grasslands, reservoirs, and wetlands showing an H-H agglomeration in terms of ESV. (3) There is a significant negative spatial correlation between the LU degree and ESV in the Huangshui River Basin, indicating that the enhancement of the LU degree in the basin could have a negative spatial spillover effect on the ESV of surrounding areas. Thus, green development should be the future direction of progress in the Huangshui River Basin, i.e., while maintaining and expanding the land for ecological protection and restoration, and the LU structure should be actively adjusted to ensure ecological security and coordinated and sustainable socioeconomic development in the Basin.

Green Tea Polyphenols Cause Apoptosis and Autophagy in HPV-16 Subgene-Immortalized Human Cervical Epithelial Cells via the Activation of the Nrf2 Pathway.

Infection with human papillomavirus (HPV) is relatively common and certain high-risk HPV strains can induce epithelial dysplasia, increasing the risk of cervical cancer. Green tea polyphenol (GTP) preparations exhibit diverse anti-inflammatory, antioxidative, and antitumor properties In Vitro and In Vivo. Topical GTP application has been recommended as a treatment for genital warts, but the effect of GTP treatment on HPV infection and HPV-associated cancer remains to be established. The present study aimed to explore the mechanism by which GTP affected HPV type 16 (HPV-16)-positive immortalized human cervical epithelial cells. Survival, apoptosis, and autophagocytosis of these cells following GTP treatment was assessed using CCK-8 assay, flow cytometry, and monodansylcadaverine (MDC) staining. These cells were further transfected with an shRNA specific for Nrf2 to generate stable Nrf2-knockdown cells. The levels of Caspase-3, Bcl-2, Bax, P53, Rb, HPV-16 E6, HPV-16 E7, P62, Beclin1 and LC3B were determined via Western blotting. These analyses revealed that GTP treatment induced autophagy and apoptosis in HPV-16-positive cells, while Nrf2 gene knockdown reversed GTP-induced autophagic and apoptotic effects. Together, these results suggested that GTP could alleviate HPV infection and HPV-associated precancerous lesions In Vitro by regulating the Nrf2 pathway, highlighting the therapeutic potential of GTP in treating HPV infection.

Curcumin protection against ultraviolet-induced photo-damage in Hacat cells by regulating nuclear factor erythroid 2-related factor 2.

Curcumin suppressed ultraviolet (UV) induced skin carcinogenesis and activated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. However, whether curcumin protects skin injury caused by UV is still unknown. A vitro model was established and curcumin effects on Hacat cells were detected. Nrf2 was knocked down in Hacat cells to verify the Nrf2 role in the protective effect of curcumin. Results indicated that ultraviolet A (UVA) (or ultraviolet B (UVB)) irradiation would lead to decreased cell proliferation, increased cell apoptosis, decreased catalase, heme oxygenase 1, and superoxide dismutase expression, and increased levels of protein carbonylation and malondialdehyde (p < 0.05). These adverse events could be reversed by adding 5-µM curcumin. Meanwhile, we found that the application of curcumin effectively induced Nrf2 nuclear accumulation in Hacat cells. While in the Nrf2 knockdown cells, the protective effects of curcumin against UVA (or UVB) were attenuated. Conclusively, curcumin protects Hacat cells against UV exposure-induced photo-damage by regulating Nrf2 expression.

Inhibition of protein kinase C activity inhibits osteosarcoma metastasis.

INTRODUCTION: For some cancers bone is the preferred site for metastasis and involves a cascade involving transition of epithelial cells to mesenchymal cells and subsequent intravasation to the blood and lymph vessels, and finally hematogenous dissemination to perivascular niches of the bone marrow sinusoids. It has been shown that protein kinase C can aid metastasis to bone. Hence, pharmacological inhibition of protein kinase C (PKC) activity is thought of as a potential therapeutic option in bone metastatic lesions. The objective of the current study was to investigate how PKCs exert their effect on bone cancer metastasis and to test the efficacy of pharmacological inhibition of PKC on bone metastasis. MATERIAL AND METHODS: The effect of the PKC inhibitor Go6983 on epithelial and mesenchymal cell marker expression in the osteosarcoma cell line DAN was determined by immunoblot and immunofluorescence analysis. The in vivo effect of Go6983 was evaluated with a xenograft model using DAN cells. RESULTS: Treatment with transforming growth factor ß (TGF-ß) led to loss of the epithelial cell marker and gain of mesenchymal cell markers in the osteosarcoma cell line, DAN. This transition occurred concomitantly with PKC activation. TGF-ß-mediated PKC activation resulted in activation of ribosomal protein 6 (S6), but not S6K1. Pharmacological inhibition of PKC activation attenuated these effects. In a xenograft model of experimental metastasis, pharmacological inhibition of PKC activation over a period of 4 weeks reduced both tumor burden and metastasis to lungs. CONCLUSIONS: Our results indicate that PKC potentiates tumor metastasis to the bone by potentiating translation increase and can be putatively inhibited by pharmacological inhibition.

Pterostilbene's protective effects against photodamage caused by UVA/UVB irradiation.

Aim: The aim of this study was to further elucidate the mechanism of pterostilbene against UVA/UVB irradiation and the Nuclear factor E2-related factor 2 (Nrf2) signal pathway. Methods: A photo-damage model with UVA/UVB irradiation in HaCat cells was established and used in this study. The dose of pterostilbene was selected through MTS assay. Cell proliferation and apoptosis in Nrf2 and knockdown Nrf2 cells was detected by MTS assay. Expression of CAT, HO-1, and SOD in Nrf2 and knockdown Nrf2 cells was explored by qPCR. Western blot was used to analysis of Nrf2 nuclear translocation changes in Nrf2 and knockdown Nrf2 cells. Protein carbonyl content and MDA content was tested. Results: Our photo-damage model was successfully established and 20J/cm² UVA and 57mJ/cm² UVB irradiation was the suitable dose for HaCaT cell damage study. UVA/UVB irradiation would affect Nrf2 protein location, especial for 9.75 µM pterostilbene dose. In addition, cell proliferation could be significantly inhibited by UVA/UVB treatments (P<0.05), whereas, 9.75 µM pterostilbene treatment can alleviate the photo-damage. UVA/UVB irradiation would lead to decreased expressions of CAT, HO-1, and SOD. Carbonyl content and MDA was significantly changed by UVA/UVB treatments (P<0.05). The adverse events could be reversed by adding 9.75 µM pterostilbene. Western blot analysis showed that Nrf2 cytoplasm content in UVA/UVB treated cells was reduced and Nrf2 nuclear content was increased, which are different with the normal HaCaT cells without knockdown Nrf2 treatment (P<0.05). The results of cell proliferation, apoptosis, and cell antioxidant capacity in knockdown Nrf2 treated HaCaT cells were also significantly different with the normal HaCaT cells without knockdown Nrf2 treatment (P<0.05). Conclusion: We hypothesize that pterostilbene could play an anti-oxidation role via the Nrf2 signal pathway.

Lycium barbarum polysaccharide protects HSF cells against ultraviolet-induced damage through the activation of Nrf2.

BACKGROUND: Lycium barbarum polysaccharide (LBP) is considered an antioxidant agent. NF-E2-related factor-2 (Nrf2) is an important regulator for protection against UV damage. In this study, we verified the performance of LBP and the correlation between LBP and Nrf2. METHODS: HSF cells were treated with LBP to determine dose and time dependencies. An antioxidant response element (ARE) reporter was designed to monitor the activity of the Nrf2 antioxidant pathway. RESULTS: For HSF cells, the optimal LBP treatment was 300 µg/ml for 3 h. The ARE-reporter assay showed that LBP could increase the robustness of p-Nrf2. Treatments with genistein and LY294002 reduced of nuclear p-Nrf2 after 24 h. LBP increased the level of nuclear Nrf2, which functions by both phosphorylation and nuclear translocation. Silencing Nrf2 led to increased reactive oxygen species (ROS) levels, lower cell viability, and decreased superoxide dismutase (SOD) and glutathione peroxidase (GSP-PX) levels. This induced a higher level of lipid peroxide (LPO). However, LBP could decrease the levels of ROS and LPO and enhance the levels of SOD and GSP-PX. CONCLUSION: LBP protects HSF cells against UV damage via the regulation of Nrf2.

Pterostilbene protects against UVB-induced photo-damage through a phosphatidylinositol-3-kinase-dependent Nrf2/ARE pathway in human keratinocytes.

OBJECTIVE: Ultraviolet B (UVB) irradiation is the initial etiological factor for various skin disorders, including erythema, sunburn, photoaging, and photocarcinogenesis. Pterostilbene (Pter) displayed remarkable antioxidant, anti-inflammatory, and anticarcinogenic activities. This study aimed to investigate the effective mechanism of Pter against UVB-induced photodamage in immortalized human keratinocytes. METHODS: Human keratinocytes were pretreated with Pter (5 and 10 µM) for 24 h prior to UVB irradiation (300 mJ/cm2). Harvested cells were analyzed by MTT, DCFH-DA, comet, western blotting, luciferase promoter, small interference RNA transfection, and quantitative real-time polymerase chain reaction assay. RESULTS: Pter significantly attenuated UVB-induced cell death and reactive oxygen species (ROS) generation, and effectively increased nuclear translocation of NF-E2-related factor-2 (Nrf2), expression of Nrf2-dependent antioxidant enzymes, and DNA repair activity. Moreover, the protective effects of Pter were abolished by small interference RNA-mediated Nrf2 silencing. Furthermore, Pter was also found to induce the phosphorylation of Nrf2 and the known phosphatidylinositol-3-kinase (PI3K) phosphorylated kinase, Akt. The specific inhibitor of PI3K, LY294002, successfully abrogated Pter-induced Nrf2 phosphorylation, activation of Nrf2-antioxidant response element pathway, ROS scavenging ability, and DNA repair activity. CONCLUSION: The present study indicated that Pter effectively protected against UVB-induced photodamage by increasing endogenous defense mechanisms, scavenging UVB-induced ROS, and aiding in damaged DNA repair through a PI3K-dependent activation of Nrf2/ARE pathway.

Lycium barbarum polysaccharide protects human keratinocytes against UVB-induced photo-damage.

Ultraviolet B (UVB) irradiation plays a key role in skin damage, which induces oxidative and inflammatory damages, thereby causing photoaging or photocarcinogenesis. Lycium barbarum polysaccharide (LBP), the most biologically active fraction of wolfberry, possesses significant antioxidative and anti-inflammatory effects on multiple tissues. In the present study, the photoprotective effects and potential underlying molecular mechanisms of LBP against UVB-induced photo-damage were investigated in immortalized human keratinocytes (HaCaT cells). The data indicated that pretreatment with LBP significantly attenuated UVB-induced decrease in cell viability, increase in ROS production and DNA damage. LBP also significantly suppressed UVB-induced p38 MAPK activation, and subsequently reversed caspase-3 activation and MMP-9 expression. Notably, LBP was found to induce Nrf2 nuclear translocation and increase the expression of Nrf2-dependent ARE target genes. Furthermore, the protective effects of LBP were abolished by siRNA-mediated Nrf2 silencing. These results showed that the antioxidant LBP could partially protect against UVB irradiation-induced photo-damage through activation of Nrf2/ARE pathway, thereby scavenging ROS and reducing DNA damage, and subsequently suppressing UVB-induced p38 MAP pathway. Thus, LBP can be potentially used for skincare against oxidative damage from environmental insults.

Topical treatment of green tea polyphenols emulsified in carboxymethyl cellulose protects against acute ultraviolet light B-induced photodamage in hairless mice.

Ultraviolet (UV) radiation causes skin injury and inflammation resulting in impaired immune response and increased risk of skin cancer. It has been shown that green tea polyphenols (GTPs) enhanced intracellular antioxidant defense and promoted the downregulation of proapoptotic genes, and they could be used to protect against the damage induced by UV irradiation. However, the high instability and poor bioavailability of GTPs impose restrictions on their potential pharmacological use. Here we show that carboxymethyl cellulose sodium (CMC-Na) had a stabilizing effect on GTPs under aqueous conditions and topical application of GTPs (emulsified in CMC-Na) had a strong photoprotective effect against acute UVB induced photodamage in uncovered (Uncv) hairless mice skin. After 8 h of incubation at 50 °C with CMC-Na, a percentage i.e. 93% of GTPs was preserved, while in the absence of CMC-Na, a percentage of only 61% was preserved. Topical treatment of emulsified GTPs effectively inhibited acute UVB-induced infiltration of inflammatory cells, increase of skin thickness, oxidative stress such as depletion of antioxidant enzymes and lipid oxidation, and induced nuclear accumulation of Nrf2 in the mice skin. We also discovered the ability of GTPs to simultaneously trigger accumulation of nuclear Nrf2 and export of nuclear Bach1. Altogether, our findings reinforced the putative application of GTPs in the prevention/minimization of the deleterious effects of UV on the skin.

Protective Effect of Curcumin Against Acute Ultraviolet B Irradiation-induced Photo-damage.

Ultraviolet B (UVB) irradiation is one of the most dangerous insults for skin and causes sunburn, erythema, photoaging and photocarcinogenesis. Curcumin (diferuloylmethane), a yellow spice derived from dried rhizomes of Curcuma longa, has been shown to possess significant anti-inflammatory, antioxidant, anticarcinogenic, antimutagenic, anticoagulant and anti-infective effects. However, the protective effects of curcumin against acute photo-damage are poorly understood. In this study, we investigated the photoprotective effects of curcumin against UVB-induced acute photo-damage in hairless mice and immortalized human keratinocytes (HaCaT). Topical application of curcumin significantly inhibited acute UVB (540 mJ cm-2 , for 3 successive days)-induced inflammatory cells, collagen accrementition derangement and lipid peroxidation, and effectively induced NF-E2-related factor 2 (Nrf2) nuclear accumulation in uncovered (Uncv) hairless mice skin. Treatment of HaCaT cells with curcumin significantly attenuated acute UVB (300 mJ cm-2 )-induced lactate dehydrogenase release, intracellular reactive oxygen species production and DNA damage, activated the expression of the phase II detoxifying enzymes and promoted DNA repair activity. The photoprotective effect provided by curcumin was potential associated with modulation of Nrf2-dependent antioxidant response. Our study suggested that curcumin is a potential agent for preventing and/or treating UV radiation-induced acute inflammation and photoaging.

Prevention of ultraviolet radiation­induced immunosuppression by sunscreen in Candida albicans­induced delayed­type hypersensitivity.

Ultraviolet (UV) radiation-induced immunosuppression leading to skin cancer has received increased attention in previous years. The present study aimed to investigate the immunoprotection offered by Anthelios sunscreen in a mouse model of Candida albicans­induced delayed­type hypersensitivity. Anthelios sunscreen was applied to the skin on the dorsal skin of BALB/c mice treated with a sub­erythema dose of solar­simulated radiation. Delayed­type hypersensitivity was induced by immunization with Candida albicans. Changes in the skin thickness of the foot pads were measured, and immunosuppression rates were also evaluated. The expression levels of CD207, CD80 and CD86 in the Langerhans cells were semi­quantitatively detected using Western blotting and immunohistochemical assays. The delayed­type hypersensitivity mouse model was successfully established. The minimal erythema doses of UVA and UVB exposure to the mice were 2,000 and 145 mJ/cm2, respectively. The immunosuppression rates in the sunscreen group and non­sunscreen group were 24.39 and 65.85%, respectively (P<0.01). The results of the Western blotting and immunohistochemistry showed that the expression levels of CD207 (P<0.01), CD80 (P<0.05) and CD86 (P<0.01) were higher in the sunscreen group, compared with those in the non­sunscreen group. UV exposure reduced Candida albicans antigen­induced delayed­type hypersensitivity. Anthelios sunscreen was found to protect the skin from immunosuppression through the activation of epidermal Langerhans cells.

Activation of coagulation, anti-coagulation, fibrinolysis and the complement system in patients with urticaria.

BACKGROUND: Recently released studies indicate that activation of blood coagulation may be involved in causing urticaria. OBJECTIVE: To evaluate whether or not anticoagulation, fibrinolysis and the complement system are also involved in the pathogenesis of urticaria. METHODS: Coagulant factors, anticoagulant factors, fibrinolytic markers and complement components were analysed in patients with acute urticaria (AU) and chronic urticaria (CU). Conclusion: The activation of coagulation, anti-coagulation, fibrinolysis and the complement system may be involved in the pathogenesis of urticaria. It also indicates that coagulation conditions in CU patients can recover after antihistamine treatment, but do not immediately return to normal levels directly after administration. RESULTS: Plasma levels of activated factor VII (FVIIa) were higher in AU patients (P <0.01) but not significantly different in CU patients (P >0.05), while levels of the thrombin-antithrombin complex (TAT) and prothrombin fragment 1+2 (F1+2) were significantly higher in CU patients (P <0.01). Levels of factor IX (FIX) and tissue factor (TF) were lower in CU patients (P <0.01). Plasma levels of tissue factor pathway inhibitor/activated factor X (TFPI/Xa) were higher in CU patients (P <0.01) but not significantly different in AU patients (P >0.05), whereas levels of thrombomodulin (TM) were lower in CU patients (P <0.01). Plasma levels of D-dimer in AU and CU patients and levels of high molecular weight kininogen (HMWK) in CU patients were increased significantly (P <0.01), while levels of tissue-type plasminogen activator (t-PA) were decreased (P <0.01). Plasma concentrations of C5a in CU patients were superior to those in healthy controls (P <0.01). Serum levels of C4 also increased (P <0.01). CONCLUSION: The activation of coagulation, anti-coagulation, fibrinolysis and the complement urticaria. It also indicates that coagulation conditions in CU patients can recover after antihistamine treatment, but do not immediately return to normal levels directly after administration.