Effects of non-landslide sampling strategies on machine learning models in landslide susceptibility mapping.

This study aims to explore the effects of different non-landslide sampling strategies on machine learning models in landslide susceptibility mapping. Non-landslide samples are inherently uncertain, and the selection of non-landslide samples may suffer from issues such as noisy or insufficient regional representations, which can affect the accuracy of the results. In this study, a positive-unlabeled (PU) bagging semi-supervised learning method was introduced for non-landslide sample selection. In addition, buffer control sampling (BCS) and K-means (KM) clustering were applied for comparative analysis. Based on landslide data from Qiaojia County, Yunnan Province, China, collected in 2014, three machine learning models, namely, random forest, support vector machine, and CatBoost, were used for landslide susceptibility mapping. The results show that the quality of samples selected using different non-landslide sampling strategies varies significantly. Overall, the quality of non-landslide samples selected using the PU bagging method is superior, and this method performs best when combined with CatBoost for predicting (AUC = 0.897) landslides in very high and high susceptibility zones (82.14%). Additionally, the KM results indicated overfitting, displaying high accuracy for validation but poor statistical outcomes for zoning. The BCS results were the worst.

Study on the space field reconstruction method of the radial basis function of electromagnetic radiation under optimal parameters.

Electromagnetic radiation (EM) pollution has a certain impact on human life and health, and the reconstruction of the EM space field in this paper is of great practical significance for EM analysis and research. The radial basis function (RBF) sufficiently considers the influence of each sampling point and is more suitable for reconstructing the EM space field than other spatial interpolation methods. Currently, when RBF is used to reconstruct the EM space field, the optimal determination of the basis function and shape parameter (SP) is rarely considered. This ultimately leads to low reconstruction accuracy of the EM space field. Therefore, in this paper, the particle swarm optimization (PSO) is used to calculate the optimal SP of the RBF. On this basis, reliable EM space field reconstruction is performed, which helps people understand the EM distribution characteristics in actual situations from a visual perspective. The EM sampling data of a region on the Yunnan Normal University campus are used as the data source, and the RBF under the optimal parameters is used for EM reconstruction. The accuracy of its interpolation results is evaluated and compared and analyzed with inverse distance weighting (IDW) after distance index optimization. The results show that the RBF under optimal parameters reconstructs the EM space field with high accuracy and good effect, which can truly reflect the actual distribution of EM.

Electromagnetic radiation (EM) pollution has a great impact on the surrounding environment. Therefore, EM space field reconstruction can help us analyze the characteristics of the electromagnetic environment in a visual way. Radial Basis Function (RBF) is a method more suitable for EM space field reconstruction than other methods because it fully considers the influence of each sampling point. However, when currently using RBF to reconstruct the EM space field, few researchers consider how to choose the most appropriate basis function and shape parameter (SP). This results in low reconstruction accuracy. Therefore, this study uses particle swarm optimization (PSO) to find the optimal SP parameters for reliable EM space field reconstruction. The study used the EM sampling data of an area within the campus of Yunnan Normal University as the study material, and a parameter-optimized RBF method was adopted for the reconstruction of the EM space field. The reconstruction results were then evaluated for accuracy and compared and analyzed with the IDW method optimized with a distance index. Research results show that using RBF with optimal parameters to reconstruct the EM space field has high accuracy and can effectively reflect the actual EM distribution, thereby helping people better understand the characteristics of the electromagnetic environment.

Study on landslide susceptibility mapping with different factor screening methods and random forest models.

The number of input factors affects the prediction accuracy of a model. Factor screening plays an important role as the starting point for data input. The aim of this study is to explore the influence of different factor screening methods on the prediction results. Taking the 2014 landslide inventory of Jingdong County as an example, a landslide database was constructed based on 136 landslide events and 11 selected factors, which were randomly divided into a training dataset and a test dataset according to a ratio of 7:3. Four factor screening methods, namely, the information gain ratio (IGR), GeoDetector, Pearson correlation coefficient and multicollinearity test (MT), were selected to screen the factors. A random forest (RF) model was then used in combination with each factor set for landslide susceptibility mapping (LSM). Finally, accuracy validation was performed using confusion matrices and ROC curves. The results show that factor screening is beneficial in improving the accuracy of the resulting model compared to the original model. Second, the IGR_RF model had the highest AUC value (0.9334), which was higher than that of the MT_RF model without factor screening (0.9194), and the IGR_RF model predicted the most landslides in the very high susceptibility zone (51.22%), indicating the good prediction performance of the IGR_RF model. Finally, the factor weighting analysis revealed that NDVI, elevation and aspect had the greatest influence on landslides in Jingdong County and that curvature had the least influence on landslides. This study can provide a reference for factor screening in LSM.

Spatial distribution, source identification, and risk assessment of heavy metals in riparian soils of the Tibetan plateau.

Riparian soils in the lower sections of the Lhasa River were chosen as the research focus, to examine the characteristics and sources of heavy metals in riparian soils of high-cold regions. To investigate the influence of various factors on the geographical distribution of heavy metals, three horizontal and one vertical profiles were considered. The geoaccumulation index, prospective ecological risk index, and enrichment factor were used to evaluate the extent of soil contamination. Correlation analysis and the positive-matrix-analysis receptor model were used to quantitatively examine the sources of the elements. According to the soil-evaluation, the topsoil was more polluted than the deep soil. Overall, the soil was slightly degraded and posed minor ecological concern. Cd was the primary contributor to the overall contamination, with moderate and considerable risk levels at certain locations. Five sources were identified for the six heavy metals. Transportation and agricultural production were the principal sources of Cd. Ni and Cr were mostly connected to agricultural practices and weathering of parent-soil materials. Pb and Zn were mostly related to geological history, geothermal development, and traffic pollution. Mineral resource development has had a major impact on Cu. Non-carcinogenic risk index of each heavy metal and their total value were <1, indicating they are not harmful to human health. The riparian soil of the Lhasa River Basin contains heavy metals from various sources; therefore, it is important to monitor these heavy metals. This study provides a scientific foundation for the safe utilization and classification of soils in high cold regions.

Development of Silver Nanoparticles Green-formulated by Matricaria Chamomilla as Novel Chemotherapeutic Nanoformulation for the Treatment of Oral Squamous Cell Carcinoma.

AIM: To develop modern chemotherapeutic nanoformulation from plant extract to treat oral squamous cell carcinoma. BACKGROUND: The use of biodegradable polymers to deliver drugs via nanoparticles solves a number of issues. AgNPs nanoparticle composites could be a promising material with applications in biological and pharmaceutical sciences. The biomolecules in the extract give the AgNPs additional stability against oxidation and corrosion. As a result, we are interested in reporting the synthesis, characterization, and uses of unique AgNPs decorated with Matricaria chamomilla extract. OBJECTIVE: We developed a natural chemotherapeutic nanoformulation containing M. chamomilla aqueous extract and silver nanoparticles (AgNPs) for treating oral squamous cell carcinoma. METHODS: UV-Visible Spectroscopy (UV-Vis), Fourier Transformed Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), and Field Emission Scanning Electron Microscopy (FESEM) were used to characterize AgNPs. The antioxidant activities of AgNO3, M. chamomilla, and AgNPs were evaluated using the DPPH assay in the presence of Butylated Hydroxytoluene (BHT) as a positive control. The MTT assay was employed on the HSC-4, Ca9-22, and HSC-3 cell lines to assess the cytotoxicity and anti-oral squamous cell carcinoma effects. RESULTS: Silver nanoparticles demonstrated reduced cell viability and anti-oral squamous cell carcinoma capabilities in HSC-4, Ca9-22, and HSC-3 cell lines in a dose-dependent manner, with minimal damage to the normal cell line. The HSC-3 cell line showed the strongest anti-oral squamous cell carcinoma characteristics of AgNPs when tested against the above cell lines. CONCLUSION: According to the findings, silver nanoparticles containing M. chamomilla aqueous extract may treat different forms of oral squamous cell carcinoma in people.

Carbon dots with intrinsic theranostic properties for photodynamic therapy of oral squamous cell carcinoma.

Carbon dots (CDs) are one of the carbon-based materials with remarkable optical properties, good water dispersibility and high biocompatibility. However, few studies have emphasized the intrinsic photodynamic and anticancer properties of CDs. Herein, we used CDs as photosensitizers to explore their photodynamic therapy (PDT) effect on oral squamous cell carcinoma (OSCC) cells. The obtained CDs had an effective cellular internalization capacity and possessed good biocompatibility in both CAL-27 and UM1 cells. After irradiation, the CDs showed obvious photodynamic effects on the test cells, which were confirmed by apoptosis analysis. In addition, the CDs exhibited excellent intracellular ROS generation under irradiation, and the subsequent induced cell death may be related to a lysosome-associated pathway.

Screening the key genes of prognostic value in the microenvironment for head and neck squamous cell carcinoma.

ABSTRACT: Head and neck squamous cell carcinoma (HNSCC) is the sixth common malignancy worldwide. The tumor microenvironment is highly related to tumor initiation, progression, and prognosis. This study aims to screen the tumor microenvironment related key genes of prognostic value for HNSCC.The gene expression and clinical data for HNSCC were downloaded from the cancer genome atlas (TCGA). The immune/stromal/ESTIMATE scores were downloaded from the website of the MD Anderson Cancer Center. Correlation of patient gender and tumor grade with immune/stromal/ESTIMATE score was tested. Patients were divided into low and high immune/stromal/ESTIMATE score subgroups. Survival analysis was performed to evaluate the prognostic value of the immune/stromal/ESTIMATE score. Tumor microenvironment related differentially expressed genes were determined and applied for functional enrichment analysis and protein-protein interaction network was predicted. The prediction value of the common differentially expressed genes on patient survival was tested.Four hundred eighty samples with complete clinical, expression data, and immune/stromal/ESTIMATE scores were enrolled for analysis. Immune/stromal/ESTIMATE score was higher in female patients than males. A total of 44 common differentially expressed genes were screened in high and low immune/stromal/ESTIMATE score subgroups. Of the 44 genes, 7 genes (ADGRG7, CSN3, CST8, KRT81, MUC7, MYH6, and SEZ6) were found to be closely related to patient survival. Enrichment analysis showed that the differentially expressed genes mainly enriched in the protein-coupled receptor signaling pathway, extracellular region, G-protein coupled receptor activity, salivary secretion, and regulation of lipolysis in adipocytes. Protein-protein interaction analysis revealed that POSTN and OGN were crucial microenvironments related genes.Tumor microenvironment related genes ADGRG7, CSN3, CST8, KRT81, MUC7, MYH6, and SEZ6 are valuable predictors for HNSCC patient survival. POSTN and OGN are crucial in modulating the microenvironment and tumor biology for HNSCC.

Abundance and mobility of metal(loid)s in reservoir sediments of Singe Tsangpo and Yarlung Tsangpo in Tibet, China: Implications for ecological risk.

Geogenic arsenic enrichment in soil and river sediments of Tibet compared to its upper crustal abundance has been observed, raising the question whether other trace elements are also enriched and thus may pose ecological risks. Because human activities are limited, the reservoir sediments after the recent construction of the Shiquan dam on the Singe Tsangpo (ST) and the Zam dam on the Yarlung Tsangpo (YT) collect and thus represent material sourced from 14,870 km2 and 157,668 km2 of drainage areas, respectively. Bulk concentrations of the metalloid (As) and 13 metals (Li, Be, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Cs, and Pb) are analyzed for 123 samples from 9 mostly silty sediment cores (depth: 11-20 cm) from the Shiquan Reservoir and for 250 samples from 13 mostly sandy sediment cores (depth: 9-28 cm) from the Zam Reservoir. These elemental concentrations are normalized to the upper crustal Fe abundance of 3.9% to arrive at a regional sediment geochemical background value for each element. The regional background values of most elements in the ST drainage and the YT drainage are comparable with the upper crustal abundance. However, three elements (Li, As, and Cs) in both drainage basins display significant enrichment compared to their respective upper crustal abundance. Sequential leaching of a subset of sediment samples from the ST (n = 18) and YT (n = 29) drainages reveals that chemical fractions of metals and metalloids in these two reservoirs are similar, with most of the elements dominated by the residual fraction with low mobility. Taken together, the ecological risks of the most studied elements in the reservoir sediments are likely low pending further aquatic bioavailability investigations, except that As, Cu, Pb, and Be deserve more attention due to their elevated levels in mobile fractions.

[Hydrochemical Characteristics and Possible Controls of the Surface Water in Ranwu Lake Basin].

To study the chemistry of surface water and potential control measures in the Ranwu Lake basin, 19 samples were collected from Ranwu Lake in 2019. Conventional hydrochemical techniques and statistical analysis methods (descriptive statistics, the Gibbs figure, ion ratio, Piper triangular diagrams) were applied to better understand the solute geochemistry and surface water hydrochemistry in the Ranwu Lake catchment. Surface water in the Ranwu catchment is slightly alkaline (pH of the samples ranged from 7.54 to 8.48 with an average value of 8.06). The concentrations of total dissolved solids (TDS) in the water range from 59.89 to 96.75 mg ·L-1 with an average of 79.98 mg ·L-1, the total dissolved solids of all samples are less than 100 mg ·L-1 and belong to fresh water. The TDS are dominated by Ca2+, Mg2+, HCO3-, and SO42- in the Ranwu Lake. The ion concentrations in the lake water samples are in the order of Ca2+ > Mg2+ > Na+ > K+. The concentrations of Na+and K+are very low. Ranging from 0.5 to 1.21 mg ·L-1, with an average value of 0.58 mg ·L-1, the equivalent concentration of Ca2+ accounts for 63.3% to 76.2% of total cations with an average value of 67.2%. The equivalent concentration of Mg2+ accounts for 23.4% to 36.2% of total cations with an average value of 31.4%. Ca2+ and Mg2+ account for 98.5% of total cations. The main anions were HCO3- and SO42-. The equivalent concentration of HCO3- accounts for 74.31% to 84.29% of total anions with an average value of 78.21%. The equivalent concentration of SO42- accounts for 9.59% to 19.37% of total anions with an average value of 15.34%. HCO3- and SO42- together account for 93.55% of total anions on average. All the water samples fall in the water-rock interaction field, which suggests that the weathering of rocks primarily controls the major ion chemistry of groundwater in this area. Solutes are mainly derived from carbonate weathering and silicate weathering. The role of cation exchange in the geochemical process of the lake and the influence of human activities on the lake are found to be weak.

Effects of dam construction on arsenic mobility and transport in two large rivers in Tibet, China.

Construction of dams on the Singe Tsangpo (ST) and the Yarlung Tsangpo (YT) Rivers, the upper stretch of the Indus and the Brahmaputra Rivers, respectively, are expected to affect material transport. To evaluate the effects of dam construction on arsenic (As) mobility and transport in the ST River and the YT River in Tibet and the downstream river basins, water column and sediment core samples in the Shiquan Reservoir of the ST River and in the Zam Reservoir of the YT River were obtained in August 2017, and January and May 2018, and additionally, at the inflows and outfalls of the reservoirs. The seasonal variation of dissolved As contents in the inflow water of the Zam Reservoir and the Shiquan Reservoir was regulated by the mixing between the low-As river runoff and the high-As hot spring input. Water residence time (WRT) is a key variable regulating the variation of dissolved As contents in reservoirs and outflow waters with time. The absence of the oxic layer at the sediment-water interface reduced the accumulation of As in surface sediments under high-flow conditions. Arsenic mobility in sediment of the two reservoirs was mainly controlled by Mn oxides and organic matter. Reservoirs with long water residence time are more favorable for As retention. Sedimentation was the main mechanism of As retention. The Shiquan Reservoir with a longer WRT of 385 days can effectively retain 55% of the total arsenic load from upstream, while the Zam Reservoir has no effective retention of arsenic due to the very short WRT of 1.1 days. These have important implications on the geochemical and ecological environments of the downstream river basins.

Dietary exposure to arsenic and human health risks in western Tibet.

The health effects of drinking water exposure to inorganic arsenic are well known but are less well defined for dietary exposure. The rising concerns of arsenic risks from diet motivated this study of arsenic concentrations in highland barley, vegetables, meat, and dairy products to evaluate arsenic exposure source and to assess health risks among rural residents of Ngari area, western Tibet. Total arsenic and arsenic speciation were measured by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography combined with ICP-MS (HPLC-ICP-MS) respectively. Average total arsenic concentrations of 0.18 ± 0.21 (n = 45, median: 0.07 mg·kg-1), 0.40 ± 0.57 (n = 17, median: 0.15 mg·kg-1), 0.21 ± 0.16 (n = 12, median: 0.17 mg·kg-1), and 0.18 ± 0.08 (n = 11, median: 0.22 mg·kg-1) were observed in highland barley, vegetables, meat, and dairy products, respectively. Inorganic arsenic was determined to be the main species of arsenic in highland barley, accounting for about 64.4 to 99.3% (average 83.3%) of total arsenic. Nearly half (44.4%) of the local residents had ingested >3.0 × 10-4 mg·kg-1·d-1 daily dose of arsenic from highland barley alone, above the maximum oral reference dose recommended by the United States Environmental Protection Agency (USEPA). The inorganic arsenic daily intake from highland barley was 3.6 × 10-4 mg·kg-1·d-1. Dietary exposure to inorganic arsenic alone increased the cancer risk probability to 5.4 in 10,000, assuming that the inorganic arsenic in highland barley has the same carcinogenic effects as that in water.

In vitro biocompatibility of biohybrid polymers membrane evaluated in human gingival fibroblasts.

The biohybrid polymer membrane (BHM) is a new biomaterial designed for the treatment of soft periodontal tissue defects. We aimed to evaluate the in vitro biocompatibility of the membrane in human gingival fibroblasts and the capability to induce cell adhesion, migration, differentiation and improving the production of the extracellular matrix. BHM and Mucograft® collagen matrix (MCM) membranes were punched into 6 mm diameter round discs and placed in 96-well plates. Human primary gingival fibroblasts were seeded on the membranes or tissue culture plastic (TCP) serving as the control. Cell proliferation/viability and morphology were evaluated after 3, 7, and 14 days of culture by cell counting kit (CCK)-8 assay and scanning electron microscopy, respectively. Additionally, the gene expression of transforming growth factor (TGF)-ß1, focal adhesion kinase (FAK), collagen type 1 (Col1), alpha-smooth muscle actin (α-SMA), and fibroblasts growth factor (FGF)-2 was analyzed at 3, 7, and 14 days of culture by qPCR. Cell proliferation on BHM was significantly higher than on MCM and similar to TCP. Gene expression of TGF-ß1, FAK, Col1, and α-SMA were significantly increased on BHM compared to TCP at most investigated time points. However, the gene expression of FGF-2 was significantly decreased on BHM at Day 7 and recovered at Day 14 to the levels similar to TCP. The finding of this study showed that BHM is superior for gingival fibroblasts in terms of adhesion, proliferation, and gene expression, suggesting that this membrane may promote the healing of soft periodontal tissue.

High Mobility Group Box 1 Protein Level as a Novel Biomarker for the Development of Peri-Implant Disease.

Peri-implant disease is a chronic inflammation of the soft and hard tissues around a dental implant, resulting from bacterial infection. Recent evidence indicates that some pro-inflammatory cytokines and chemokines released by immunocytes are substantially responsible for the progress and consequence of inflammation. High mobility group box 1 (HMGB1) is released into the extracellular matrix and acts as a key pro-inflammatory factor during injury, necrosis and inflammation. A higher concentration of HMGB1 has been found in gingival crevicular fluid from inflammatory gingival tissue than from healthy sites. HMGB1 mRNA and protein are overexpressed in murine periodontal ligament fibroblasts stimulated with lipopolysaccharide (LPS) and IL-1ß. Thus, this study sought to assess HMGB1 expression in peri-implant crevicular fluid (PICF) at each stage of peri-implant disease and to investigate the correlation between HMGB1 and peri-implant disease progress. The results demonstrated that the HMGB1 expression level in PICF is indicative of the progress of peri-implant disease and hence may be a useful diagnostic and prognostic biomarker for peri-implant tissue.

Magnetic Resonance Imaging (MRI) Evaluation for Anterior Disc Displacement of the Temporomandibular Joint.

BACKGROUND Magnetic resonance imaging (MRI) is the criterion standard imaging technique for visualization of the temporomandibular joint (TMJ) region, and is currently considered the optimum modality for comprehensive evaluation in patients with temporomandibular joint disorder (TMD). This study was aimed at finding the value of MRI in pre-clinical diagnosis of TMJ disc displacement. MATERIAL AND METHODS Patients primarily diagnosed as having anterior disc displacement by clinical symptoms and X-ray were selected in the present study. MRI was used to evaluate surrounding anatomical structures and position, as well as morphological and signal intensity change between patients and normal controls. RESULTS Posterior band position was significantly different between the patient group and control group. At the maximum opened-mouth position, the location of disc intermediate zone returned to normal. At closed-mouth position, the thickness of anterior and middle, but not posterior, band increased. The motion range of the condyle in the anterior disc displacement without reduction (ADDWR) patient group was significantly less than the value in the anterior disc displacement with reduction (ADDR) patient group and the control group. Whether at closed-mouth position or maximum opened-mouth position, the exudate volume in the patient group was greater than in the normal group. CONCLUSIONS MRI can be successfully used to evaluate multiple morphological changes at different mouth positions of normal volunteers and patients. The disc-condyle relationship can serve as an important indicator in assessing anterior disc displacement, and can be used to distinguish disc displacement with or without reduction.

[Therapeutic effect of GDNF gene-modified mesencephalic neural stem cell transplantation in a rat model of Parkinson disease].

OBJECTIVE: To evaluate the therapeutic effect of transplantation of mesencephalic neural stem cells (mNSCs) genetically modified by glial cell line-derived neurotrophic factor (GDNF) gene in a rat model of Parkinson disease. METHODS: mNSCs isolated from the lateral component of the midbrain of fetal rats at gestational age of 14 or 15 days were cultured for 5 days before genetic modification with GFP or GDNF gene. Rat models of Parkinson disease established by stereotactic injection of 6-hydroxy dopamine in the ventral area of the midbrain and the medial forebrain bundle were randomized into 3 groups to receive PBS injection, GFP gene-modified mNSCs transplantation, or GDNF gene-modified mNSCs transplantation into the right stratum. The behavioral changes of the rats were evaluated by observing rotations induced by intraperitoneal injection of apomorphine after the transplantation, and the survival, migration and differentiation of the transplanted cells were identified by immunohistochemistry. RESULTS: Transplantation with GDNF gene-modified mNSCs significantly improved the behavioral abnormalities of the rat models as compared with PBS injection and GFP gene-modified mNSCs transplantation. At 56 days after the transplantation, a greater number of the transplanted cells survived in the rat brain and more differentiated dopaminergic neurons were detected in GDNF gene-modified mNSCs transplantation group than in GFP gene-modified mNSCs transplantation group. CONCLUSION: GDNF gene-modified mNSCs transplantation can significantly improve dyskinesia in rat models of Parkinson disease, but the molecular mechanism needs further clarification.

Down-Regulating Receptor Interacting Protein Kinase 1 (RIP1) Promotes Oxaliplatin-Induced Tca8113 Cell Apoptosis.

BACKGROUND: Oxaliplatin is a crucial chemotherapy drug that plays an important role in colorectal cancer and oral cancer treatment. However, the molecular mechanism of oxaliplatin in killing tongue squamous cell cancer cells is still unknown. This paper investigates the mechanism of by which oxaliplatin regulates tongue squamous cell carcinoma Tca8113 cell survival and death. MATERIAL AND METHODS: Tca8113 was treated with 1 µmol/L oxaliplatin for 24 h. Tca8113 cell proliferation and apoptosis were determined by MTT method and flow cytometry, respectively. Western blot was applied to detect receptor-interacting protein kinase 1 (RIP1) level. Tca8113 was transfected with siRNA RIP1 and then treated with 1 µmol/L oxaliplatin, and the cell apoptosis was detected. RESULTS: We found that 1 µmol/L oxaliplatin could inhibit Tca8113 cell growth (cell survival rate was 19.3%), reduce mitochondrial membrane potential (reduce 82.3%) and phosphatidylserine eversion (positive rate was 62.7%), and activate caspase-3 (increased 2.6 times). We also found that 1 µmol/L oxaliplatin treatment could increase RIP1 expression in Tca8113 cells. Cell apoptosis rate increased after siRNA RIP1 and 1 µmol/L oxaliplatin treatment (apoptosis rate was 90.2%). CONCLUSIONS: Down-regulating RIP1 promotes oxaliplatin induced Tca8113 cells apoptosis.

[Effects of PRF and released three growth factors on migration of rat adipose tissue-derived stem cells].

PURPOSE: To analyze the effects of PRF and released three growth factors on migration of rat adipose tissue-derived stem cells and to investigate the mechanism of migration. METHODS: The inguinal adipose tissue of rat was excised at aseptic condition to obtain primary ADSCs by enzyme digestion. Multi-directional differentiation was used to identify the ADSCs. PRF membrane was acquired through one time centrifuge. The cell migration was examined by Transwell assay and wound healing assay. The mRNA expression of MMP2 and MT1-MMP was tested by real-time PCR. Statistical analysis was performed using SPSS 13.0 software package. RESULTS: Cell migration test showed that the migration of rat ADSCs in PRF group were significantly higher than those in the negative group（P<0.05） and inhibitor group（P<0.05）. The ADSCs migration effects in three growth factors group at different concentrations showed significant difference（P<0.05）. Real-time PCR showed that gene expressions of MMP2 and MT1-MMP were significantly higher in PRF group than control group (P<0.05). PCR showed that gene expressions of MMP2 and MT1-MMP were significantly higher in three growth factors group than control group (P<0.05). CONCLUTIONS: PRF and three growth factors consistently enhanced the migration of rat ADSCs in a dose-response manner. The migration increase of rat ADSCs may be associated with the up-regulation of MMP2 and MT1-MMP gene expression.

miR-101 sensitizes A549 NSCLC cell line to CDDP by activating caspase 3-dependent apoptosis.

MicroRNA-101 (miR-101) is evidently downregulated in several types of cancer, including non-small cell lung cancer (NSCLC), and is crucial in sensitizing cells to chemotherapy drugs. The aim of the present study was to investigate the correlation between miR-101 and chemosensitivity in the A549 NSCLC cell line. Here, we used the human A549 cell line for transfection with an miR-101 overexpressing vector and detected the cytotoxic acticity, proliferation and apoptosis of cis-diaminedichloroplatinum (CDDP) in A549-miR-101 and A549-mock cells. We demonstrated that overexpression of miR-101 sensitized A549 cells to CDDP, one of the most frequently used agents in curing or controlling NSCLC and enhanced CDDP-induced cell death and caspase 3-dependent apoptosis. In addition, miR-101 facilitated the inhibitory role of CDDP in A549 cell colony formation. Overall, the results of the present study demonstrated that miR-101 sensitizes the A549 NSCLC cell line to CDDP via the activation of caspase 3-dependent apoptosis.

Enrichment of Arsenic in Surface Water, Stream Sediments and Soils in Tibet.

Groundwater in sedimentary deposits in China, Southern, and Southeast Asia down gradient from the Tibetan plateau contain elevated As concentrations on a regional scale. To ascertain the possibility of source region As enrichment, samples of water (n=86), stream sediment (n=77) and soil (n=73) were collected from the Singe Tsangpo (upstream of the Indus River), Yarlung Tsangpo (upstream of the Brahmaputra River) and other drainage basins in Tibet in June of 2008. The average arsenic concentration in stream waters, sediments and soils was 58±70 µg/L (n=39, range 2-252 µg/L), 42±40 mg/kg (n=37, range 12-227 mg/kg), and 44±27mg/kg (n=28, range 12-84 mg/kg) respectively for the Singe Tsangpo and was 11±17 µg/L (n=30, range 2-83 µg/L), 28±11 mg/kg (n=28, range 2-61 mg/kg), and 30±34 mg/kg (n=21, range 6-173 mg/kg) respectively for the Yarlung Tsangpo. A dug well contained 195 µg/L of As. In addition to elevated As levels in surface and shallow groundwater of Tibet, hot spring and alkaline salt lake waters displayed very high As levels, reaching a maximum value of 5,985 µg/L and 10,626 µg/L As, respectively. The positive correlation between [As] and [Na]+[K] in stream waters indicates that these surface water arsenic enrichments are linked to the hot springs and/or salt lakes. Further, 24% of As in stream sediment is reductively leachable, with bulk As displaying a positive correlation with stream water As, suggesting sorption from stream water. In contrast, the fraction of reductively leachable As is negligible for soils and several rock samples, suggesting that As in them are associated with unweathered minerals. Whether the pronounced As anomaly found in Tibet affects the sedimentary As content in deltas downstream or not requires further study.

[Distribution of arsenic in surface water in Tibet].

This research was aimed on studying the arsenic distribution of water in Yarlung Zangbo and Singe Zangbo basins in Tibet. Results showed that arsenic concentrations were different in different types of the water. The sequence of arsenic concentration from high to low was hot spring water (4920 microg x L(-1) +/- 1520 microg x L(-1), n =2), salt lake water (2180 microg x L(-1) +/- 3840 microg x L(-1), n =7), well water (194 microg x L(-1), n = 1), freshwater lake water (163 microg x L(-1) +/- 202 microg x L(-1), n =2) and stream water (35.5 microg x L(-1) +/- 57.0 microg x L(-1), n=74). The high arsenic concentration in surface water in Singe Zangbo and the upstream of Yarlung Zangbo were found. The average concentration of arsenic in water from Singe Zangbo (58.4 microg x L(-1) +/- 69.9 microg x L(-1), n = 39) was significantly higher than that from Yarlung Zangbo (10.8 microg x L(-1) +/- 16.9 microg x L(-1), n = 30). Arsenic concentration in 43.2% of stream water samples and all of the hot springs, saline lakes and well water were higher than 10 microg x L(-1). Yarlung Zangbo and Singe Zangbo are important sources of drinking water for the local people. There is a high risk for the local people who may suffer from chronic arsenic poisoning.