Comparison between computer recognition and manual measurement methods for the estimation of leaf area.

BACKGROUND AND AIMS: Leaf area (A) is a crucial indicator of the photosynthetic capacity of plants. The Montgomery equation (ME), which hypothesizes that A is proportional to the product of leaf length (L) and width (W), is a valid tool for nondestructively measuring A for many broad-leaved plants. At present, the methods used to compute L and W for ME can be broadly divided into two kinds: using computer recognition, and measuring manually. However, the potential difference in the prediction accuracy using either method has not been thoroughly examined in prior studies. METHODS: In the present study, we measured 540 Alangium chinense leaves, 489 Liquidambar formosana leaves, and 215 Liriodendron × sinoamericanum leaves, utilizing computer recognition and manual measurement methods to determine L and W. ME was used to fit the data determined by the two methods, and the goodness of fits were compared. The prediction errors of A were analyzed by examining the correlations with two leaf symmetry indices (areal ratio of the left side to the right side, and standardized index for bilateral asymmetry), as well as the leaf shape complexity index (the leaf dissection index). KEY RESULTS: The results indicate that there is a neglectable difference in the estimation of A between both methods. This further validates that ME is an effective method for estimating A in broad-leaved tree species, including those with lobes. Additionally, leaf shape complexity significantly influenced the estimation of A. CONCLUSIONS: These results show that the use of computer recognition and manual measurement in the field are both effective and feasible, although the influence of leaf shape complexity should be considered when applying ME to estimate A in the future.

[Characterization of Metal Pollution of Regional Atmospheric PM2.5 and Its Sources Based on the PMF Model].

As important components of PM2.5, metal elements are extremely harmful to people and also have source specificity. Understanding the characteristics of PM2.5 metal pollution in the two different types of cities can help adjust the layout of regional industrial structure and improve the environment. PM2.5 samples during haze/non-haze periods were collected in Chengdu City and Renshou County. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to determine the mass concentrations of eighteen metal elements in collected PM2.5 samples. The positive matrix factorization (PMF) model was used for source apportionment analysis for metal elements in PM2.5. The analysis showed that the ratio of trace elements from fugitive dust, motor vehicle emissions, and coal burning to the total elements is greater in Chengdu City than that in Renshou County. The proportion of trace elements from biomass combustion, industrial, and fuel sources in Renshou County is higher than that in Chengdu City. In addition, concentrations of Cd, As, and Cr in both areas exceeded the standards, indicating the occurrences of heavy metal pollution. During the haze period, the total concentrations of compositional metal elements in PM2.5 increased, although the rate was much lower than that for PM2.5. The ratios of elements between haze and non-haze periods ranged from 0.7 (Al) to 2.8 (Ba) in Chengdu City, and from 0.8 (Al) to 3.1 (Mn) in Renshou County. Among all metal elements, the increase rate for trace elements from coal burning and industrial activities was relatively large but small for those from fugitive dust, with the growth in trace elements from motor vehicles being modest. The results of this study indicated that the characteristics of pollution and source of metal elements in PM2.5 varied by economic scale, development mode, and industrial layout. In large cities such as Chengdu City, where economic development is mainly focused on tertiary industry, air pollution is mainly caused by transportation and urban construction, while in suburban area such as Renshou County, where secondary or heavy industry are the focus for economic development, the pollution is mainly affected by energy consumption and industrial production.

[Comparative Analysis of Pollution Characteristics of Carbonaceous Aerosol Components in the Atmosphere Between Urban and Suburban Areas].

To compare the pollution characteristics of carbonaceous aerosol components in the atmosphere between urban and suburban areas, Chengdu City and Renshou County were selected as study areas from which 88 samples of PM2.5 during haze and non-haze periods were collected and analyzed. Quantification of mass concentrations of PM2.5, carbonaceous aerosol components[organic carbon (OC), elemental carbon (EC), and secondary organic carbon (SOC)], along with correlation analysis of OC and EC, and principal component analysis (PCA) of carbon components were carried out. The results show that pollutant concentrations during the haze period were higher than those during the non-haze period. The OC and EC for Chengdu City and Renshou County were positively correlated, with their correlation coefficients during the non-haze period higher than those during the haze period. The ratios of SOC/PM2.5 in Renshou County were higher than those in Chengdu City during the haze period. This indicates that secondary aerosols play a more important role in haze formation in Renshou than in Chengdu City. In contrast, the proportion of secondary aerosols during the non-haze period in Chengdu City was significantly higher, indicating that direct emissions are still the main cause of air pollution in Chengdu City. PCA results showed that PM2.5 formation in both Chengdu City and Renshou County was mainly due to coal burning, vehicle operation, and biomass burning.

Upregulation of SPAG6 in Myelodysplastic Syndrome: Knockdown Inhibits Cell Proliferation via AKT/FOXO Signaling Pathway.

Recently, sperm-associated antigen 6 (SPAG6), a member of the cancer-testis antigen family, has been shown to be involved in tumorigenesis. An increasing number of studies have shown that SPAG6 expression is associated with the pathogenesis of myelodysplastic syndrome (MDS). However, the mechanism has not been clearly elucidated. Our previous results indicated that SPAG6 affected cell apoptosis in MDS. In this study, we used reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to demonstrate that the mRNA expression of SPAG6 in bone marrow cells of patients with MDS or MDS-derived acute myeloid leukemia (MDS-AML) was higher than that of cancer-free patients. Kaplan-Meier survival curve analysis of published AML found that patients with high expression of SPAG6 had poor survival. The results of the cell counting kit-8, FACS, RT-qPCR, and Western blotting assays indicated that SPAG6 knockdown in the SKM-1 cell line inhibited cell proliferation, and affected cell cycle and differentiation. Furthermore, we found that SPAG6 knockdown affected the proliferation of SKM-1 cells by mediating the G1-to-S transition of the cell cycle. Moreover, we demonstrated that the antiproliferative effect of SPAG6 knockdown was associated with the upregulation of the cyclin-dependent kinase inhibitor p27Kip1, and regulation of the AKT/FOXO pathway. These findings indicated that SPAG6 might be a potential therapeutic target.

MicroRNA­143 increases cell apoptosis in myelodysplastic syndrome through the Fas/FasL pathway both in vitro and in vivo.

Whilst the role of microRNA­143 (miR­143) in myelodysplastic syndrome (MDS) remains unclear, abnormally expressed microRNA­143 has been detected in many types of cancer tissues. In this study, we describe a cohort study for the verification of miR­143 expression, as well as the investigation of the molecular mechanisms of miR­143 in MDS/acute myeloid leukaemia (AML). In a series of experiments, miR­143 recombinant lentiviral vectors transformed into SKM­1 cells were either overexpressed or knocked down, and the results illustrated that the overexpression of miR­143 inhibited SKM­1 cell growth, arrested the SKM­1 cells in the G0/G1 phase, interfered with cell proliferation and induced cell apoptosis via the Fas/FasL pathway. Conversely, miR­143 knockdown induced a decrease in the apoptosis and promoted the proliferation of SKM­1 cells. Moreover, miR­143 was shown to suppress MLLT3/AF9 expression by binding to its 3'­UTR. Taken together, the findings of this study indicate that miR­143 may be a critical regulator of MDS/AML cell carcinogenesis, acting as a potent antitumour molecular target for the diagnosis or treatment of cancers associated with the abnormal expression of MLLT3/AF9, hence facilitating the development of potential therapeutics against MDS/AML.

Association between serum leptin levels and breast cancer risk: An updated systematic review and meta-analysis.

BACKGROUND: Many studies have indicated that leptin is correlated with breast cancer occurrence and tumor behavior. However, this issue remains controversial. Therefore, we conducted an updated meta-analysis to investigate the role of leptin in breast cancer. METHODS: We performed a systematic literature search and identified relevant papers up to 1 September 2017. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were used to evaluate effect sizes. RESULTS: Thirty-five eligible studies were included in the current meta-analysis. Serum leptin levels were related to breast cancer risk as demonstrated by calculations of the overall SMD = 0.46 (95% CI = 0.31-0.60, I = 93.5%). A subgroup analysis of BMI identified an association between breast cancer and serum leptin levels in patients who are overweight and obese (overweight: SMD = 0.35, 95% CI = 0.13-0.57, I = 88.1%; obesity: SMD = 1.38, 95% CI = 0.64-2.12, I = 89.6%). Additionally, menopausal status subgroup analysis revealed a significant association in postmenopausal women (SMD = 0.26, 95% CI = 0.12-0.40, I = 77.9%). Furthermore, we identified a significant association between breast cancer and serum leptin levels in Chinese women (SMD = 0.61, 95% CI = 0.44-0.79, I = 40.6%). CONCLUSION: The results of this meta-analysis suggested that leptin could be a potential biomarker for breast cancer risk in women, especially overweight/obese or postmenopausal women. Therefore, it may be useful for identifying subjects with a high risk for breast cancer who may benefit from preventive treatments.

[A new method for the preparation of potassium ferrate and spectroscopic characterization].

Calcium hypochlorite was used as the raw material for preparation of the high purity potassium ferrate. The study includes the effects of reaction temperature, recrystallization temperature, reaction time, Ca(ClO)2 dosage, and the amount of calcium hypochlorite on the yield. It was determined that when the reaction temperature was 25 degrees C, recrystallization temperature 0 degree C and reaction time 40 min, the yield was more than 75%. The purity was detected by direct spectrophotometric method to be more than 92%. The product was characterized by infrated spectrum(IR), X-ray diffraction (XRD) and ultraviolet spectrum (UV) methods and proved to be potassium ferrate that was prepared by calcium hypochlorite as the raw material.

[Removal of arsenic (II) by ferrate oxidation-coagulation from drinking water].

Ferrate is multi-function agent in water treatment and shows great oxidizing ability and excellent purifying effect. This experiment evaluated the performance of ferrate for arsenic removal. Experimental results show that the best rate of ferrate and arsenic (III) is 15:1, the efficiency of As removal can be achieved 98%, and the residual concentration of As3 + is < 0.05 mg/L. The optimum pH is 5.5 to approximately 7.5. The oxidative and coagulation time is 10 min and 30 min respectively. The salinity and hardness did not interfere with removal arsenic. This method is easy, very effective comparing with ferric method and KMnO4-Ferric method.