On-orbit radiometric calibration of the optical sensors on-board SuperView-1 satellite using three independent methods.

On-orbit radiometric calibration of the optical sensors on-board SuperView-1 satellites is the foundation for further quantitative applications. A field calibration campaign was orchestrated to radiometrically calibrate the SuperView-1 optical sensors at the Baotou calibration site in China during September 2018. Based on the collected datasets, three independent methods (reflectance-based, radiance-based, and cross-calibration) were used to determine the radiometric calibration coefficients of the SuperView-1 optical sensors with multiple permanent artificial calibration targets. Comparisons of the desert top-of-atmosphere radiance calculated based on the coefficients determined with independent methods were analyzed. Comparison results show that the minimum and maximum relative differences of the radiometrically-calibrated desert TOA radiance between the reflectance-based and radiance-based methods are 1.26% and 4.23% for SV0102 and SV0104, respectively. While, the minimum and maximum relative differences of the radiometrically-calibrated desert TOA radiance between the reflectance-based and radiance-based methods are 0.82% and 6.83% for SV0101 and SV0103, respectively. The reasonably good agreement of the radiometrically calibrated coefficients of the SuperView-1 on-board sensors between these independent methods is encouraging. An uncertainty analysis was also discussed, and the results suggest that the overall uncertainties of the predicted TOA radiance are less than 4.5%, 4.0%, and 5.15% for the reflectance-based, radiance-based, and cross-calibration methods, respectively.

Immunohistochemistry and clinical value of sirtuin 2 in non-metastasized non-small cell lung cancer.

BACKGROUND: This study aimed to define whether sirtuin 2 (SIRT2) expression levels are related to the prognosis of non-small cell lung cancer (NSCLC) patients. METHODS: A survival analysis was carried out using the Kaplan-Meier (KM) plotter database. Immunohistochemical staining was performed and KM's method was used to estimate the survival rates for SIRT2 expression in 72 clinical samples. RESULTS: A survival analysis of 1,926 NSCLC patients showed that patients with low SIRT2 expression levels had significantly longer overall survival (OS) than those with high SIRT2 expression levels (P=0.0077; HR =1.19). In 72 non-metastasized NSCLC tissues, the positive rate of SIRT2 expression was 90.3% (65/72), among which, the positive expression rates of squamous cell carcinoma (SCC) and adenocarcinoma (ADC) were 96.4% (27/28) and 85.4% (35/41), respectively. Survival analysis showed that patients with low SIRT2 expression levels had significantly longer median survival time (MST) than those with high SIRT2 expression levels (15.0 versus 14.0 months, P=0.029). Furthermore, the results of subgroup analysis demonstrated patients with low SIRT2 expression levels had significantly longer survival time in ADC group (15.0 versus 12.0 months, P=0.022), but there wasn't significant difference in SCC group (15.0 versus 14.0 months, P=0.932). A multivariate Cox proportional hazards model, which included gender, age, TNM stage, differentiation and SIRT2 expression, showed that SIRT2 expression was an independent factor related to prognosis [HR =1.903, 95% confidence interval (95% CI): 1.085-3.339, P=0.025]. CONCLUSIONS: SIRT2 expression levels were significantly related to the survival time of patients with lung ADC but not SCC. Our study indicated SIRT2 was perhaps a specific prognostic biomarker for non-metastasized lung ADC.

[Progress on base editing systems].

Base editing is a newly developed precise genome editing technique based on the CRISPR/Cas system. According to different base modification enzymes, the current base editing systems can be divided into cytosine base editors (CBE) and adenine base editors (ABE). They use cytosine deaminases or artificially evolved adenine deaminases to perform single-base editing, and achieve C to T (G to A) or A to G (T to C) substitutions, respectively. Due to high efficiency, independence of DNA double-strand breaks, and no need for donor DNA, base editing systems have been successfully applied in diverse species including animals, plants and other organisms since the first report in 2016. Therefore, base editing systems will have a high prospect of providing important support for gene therapy and crop genetic improvement in the future. In this review, we describe the development and current applications of base editing systems for basic research and biotechnology, highlight the challenges, and discuss the directions for future research in this important field. The information presented may facilitate interested researchers to grasp the principles of base editing, to use relevant base editing tools in their own studies, or to innovate new versions of base editing in the future.

Land surface reflectance retrieval from optical hyperspectral data collected with an unmanned aerial vehicle platform.

We present a physical-based atmospheric correction algorithm for land surface reflectance retrieval based on radiative transfer model MODTRAN 5, with which the aerosol optical thickness @550 nm (AOT@550nm), columnar water vapor (CWV) could also be estimated from the hyperspectral data collected over UAV platform. Then, the method was tested on both the synthetic and field campaign-collected hyperspectral data by an UAV-VNIRIS (UAV visible/near-infrared imaging hyperspectrometer) with the spectral range covering from 400 to 1000 nm. The retrieval results were validated with theoretical values from synthetic data and truth values from field campaign measurements. The results show that the averaged MAE (mean absolute error) and RMSE (root mean squared error) of measured and retrieved surface reflectance based on estimated AOT@550nm and CWV is 0.0134 and 0.0130. Meanwhile, the averaged MAE and RMSE of measured and retrieved surface reflectance based on ground measured AOT@550nm and CWV is 0.0101 and 0.0112. The results show that our introduced method has good agreement with the method based on ground-measured AOT@550nm and CWV. These encouraging results also indicate that the introduced physical-based atmospheric approach provides a quick and reliable way to acquire the land surface reflectance from UAV platform-observed hyperspectral data for further quantitative remote sensing applications.

Effects of liraglutide, metformin and gliclazide on body composition in patients with both type 2 diabetes and non-alcoholic fatty liver disease: A randomized trial.

AIMS/INTRODUCTION: To compare the effects of gliclazide, liraglutide and metformin on body composition in patients with type 2 diabetes mellitus with non-alcoholic fatty liver disease. MATERIALS AND METHODS: A total of 85 patients were randomly allocated to receive gliclazide (n = 27), liraglutide (n = 29) or metformin (n = 29) monotherapy for 24 weeks. Body composition was measured using dual-energy X-ray absorptiometry. RESULTS: Liraglutide and metformin reduced total, trunk, limb, android and gynoid fat mass; this also led to weight reduction. However, gliclazide treatment produced no significant changes in weight or fat mass, likely because reductions in fat mass were concomitant with increases in lean tissue mass. Blood glucose concentrations and glycated hemoglobin levels improved in all treatment arms; levels of the latter were lower in patients treated with liraglutide and metformin. Serum alanine aminotransferase concentrations decreased in all treatment arms, whereas serum aspartate aminotransferase concentrations were reduced only by liraglutide and metformin. In all patients, weight loss and total, trunk, limb, and android fat mass reductions were positively correlated with decreases in serum alanine aminotransferase and aspartate aminotransferase levels, whereas reductions in waist circumference were positively correlated with lower serum alanine aminotransferase levels. CONCLUSIONS: Compared with gliclazide, liraglutide and metformin monotherapies result in greater weight loss, reductions in body fat mass, and better blood glucose control among type 2 diabetes mellitus patients with non-alcoholic fatty liver disease. Reductions in weight, fat mass and waist circumference favorably affect hepatic function.

Effects of exenatide versus insulin glargine on body composition in overweight and obese T2DM patients: a randomized controlled trial.

BACKGROUND: Weight loss, especially fat mass reduction, helps to improve blood glucose control, insulin sensitivity, and ß-cell function. This study aimed to compare the effect of exenatide and glargine on body composition in overweight and obese patients with type 2 diabetes (T2DM) who do not achieve adequate glycemic control with metformin. METHODS: We performed a prospective, randomized study of 37 overweight or obese patients with T2DM who had inadequate glycemic control with metformin. The patients were treated with either exenatide or glargine for 16 weeks. Dual-energy X-ray absorptiometry was used to assess body composition. RESULTS: Post-intervention weight, body mass index (BMI), waist circumference, body mass, and fat mass were lower in patients treated with exenatide, while weight and BMI significantly increased with glargine. Reductions in weight, BMI, body fat mass, and percent fat mass (except for gynoid) were greater with exenatide than with glargine, and percent lean tissue (other than the limbs) increased with exenatide. In all body regions except for the limbs, fat mass decreased with exenatide to a greater extent than lean tissue. Glucose control, insulin resistance, and ß-cell function were not different between the treatment groups. CONCLUSIONS: For overweight and obese patients whose T2DM was inadequately controlled with metformin, exenatide and glargine achieved similar improvements in glycemic control, insulin sensitivity, and ß-cell function.However, exenatide produced better weight and fat mass reduction, which were beneficial for blood glucose control. Our findings may guide the selection of appropriate drugs for glycemic and weight control. TRIAL REGISTRATION: NCT02325960, registered 25 December 2014.

SPOP promotes FADD degradation and inhibits NF-κB activity in non-small cell lung cancer.

FAS-associated protein with death domain (FADD) is the pivotal adaptor protein, which transmits apoptotic signals mediated by the death receptors. Here we report that high FADD protein level predicts poor prognosis of non-small cell lung cancer (NSCLC) patients and its protein level is mainly regulated by the 26S proteasome. We also found that ubiquitin ligase SPOP (speckle-type POZ protein) binds to FADD and mediates its degradation, which can be blocked by MG132 treatment. Notably, SPOP inhibits NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) activity and its target genes expression via FADD. These results reveal the function of SPOP-FADDNFκB axis in NSCLC cells, which is associated with prognosis of NSCLC patients.

Research progress of genome editing and derivative technologies in plants.

Genome editing technologies using engineered nucleases have been widely used in many model organisms. Genome editing with sequence-specific nuclease (SSN) creates DNA double-strand breaks (DSBs) in the genomic target sites that are primarily repaired by the non-homologous end joining (NHEJ) or homologous recombination (HR) pathways, which can be employed to achieve targeted genome modifications such as gene mutations, insertions, replacements or chromosome rearrangements. There are three major SSNs─zinc finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN) and clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9) system. In contrast to ZFN and TALEN, which require substantial protein engineering to each DNA target, the CRISPR/Cas9 system requires only a change in the guide RNA. For this reason, the CRISPR/Cas9 system is a simple, inexpensive and versatile tool for genome engineering. Furthermore, a modified version of the CRISPR/Cas9 system has been developed to recruit heterologous domains that can regulate endogenous gene expression, such as activation, depression and epigenetic regulation. In this review, we summarize the development and applications of genome editing technologies for basic research and biotechnology, as well as highlight challenges and future directions, with particular emphasis on plants.

[CRISPR/Cas: a novel way of RNA-guided genome editing].

Bacteria and archaea have evolved an adaptive immune system, known as type II prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system, which uses short RNA to direct the degradation of target sequences present in invading viral and plasmid DNAs. Recent advances in CRISPR/Cas system provide an improved method for genome editing, showing robust and specific RNA-guided endonuclease activity at targeted endogenous genomic loci. It is the latest technology to modify genome DNA specifically and effectively following zinc finger nucleases (ZFNs) and TALE nucleases (TALENs). Compared with ZFNs and TALENs, CRISPR/Cas is much simpler and easier to engineer. This review summarizes recent progress, and discusses the prospects of CRISPR/Cas system, with an emphasis on its structure, principle, applications and potential challenges.

Specific TaqMan probed real-time quantitative RT-PCR methods and their application to differentiate the transcripts of duplicated BF or BLB genes in chicken MHC.

BF and BLB genes of chicken major histocompatibility complex (MHC) are responsible for classical antigen processing and presentation; therefore they play a central role in determining the genetic resistance or susceptibility of different MHC-B haplotypes to some infectious diseases. In this study, we developed specific TaqMan probed real-time quantitative reverse transcription PCR (TaqMan qRT-PCR) methods based on the diagnostic nucleotide polymorphisms present in duplicated BF or BLB genes in B2 and B19 haplotypes. The results showed very similar amplification efficiency but no cross-reaction between the duplicated BF or BLB genes of the same haplotype. Spleen mRNA samples of B2 and B19 chickens were used to validate these TaqMan qRT-PCR methods. We observed that BF2 or BLB2 gene was dominantly transcribed in all B2 and B19 chickens. Our findings verified the impact of diversified promoter sequences on the function of duplicated BF or BLB genes. Hence the principles adopted to establish these specific TaqMan qRT-PCR methods in this study can be applied to differentiate the transcripts of duplicated BF or BLB genes of other MHC-B haplotypes in chicken.