Acarbose improved survival for Apc+/Min mice

Acarbose blocks the digestion of complex carbohydrates, and the NIA Intervention Testing Program (ITP) found that it improved survival when fed to mice. Yet, we do not know if lifespan extension was caused by its effect on metabolism with regard to the soma or cancer suppression. Cancer caused death for ~80% of ITP mice. The ITP found rapamycin, an inhibitor to the pro‐growth mTORC1 (mechanistic target of rapamycin complex 1) pathway, improved survival and it suppressed tumors in Apc^+/Min mice providing a plausible rationale to ask if acarbose had a similar effect. Apc^+/Min is a mouse model prone to intestinal polyposis and a mimic of familial adenomatous polyposis in people. Polyp‐associated anemia contributed to their death. To address this knowledge gap, we fed two doses of acarbose to Apc^+/Min mice. Acarbose improved median survival at both doses. A cross‐sectional analysis was performed next. At both doses, ACA fed mice exhibited reduced intestinal crypt depth, weight loss despite increased food consumption and reduced postprandial blood glucose and plasma insulin, indicative of improved insulin sensitivity. Dose‐independent and dose‐dependent compensatory liver responses were observed for AMPK and mTORC1 activities, respectively. Only mice fed the high dose diet exhibited reductions in tumor number with higher hematocrits. Because low‐dose acarbose improved lifespan but failed to reduced tumors, its effects seem to be independent of cancer. These data implicate the importance of improved carbohydrate metabolism on survival.     

A colorimetric sensor array based on natural pigments for the discrimination of saccharides

A colorimetric sensor array based on natural pigments was developed to discriminate between various saccharides. Anthocyanins, pH‐sensitive natural pigments, were extracted from fruits and flowers and used as components of the sensor array. Variation in pH, due to the reaction between saccharides and boronic acids, caused obvious colour changes in the natural pigments. Only by observing the difference map with the naked eye could 11 common saccharides be divided into independent individuals. In conjunction with pattern recognition, the sensor array clearly differentiated between sugar and sugar alcohol with highly accuracy and allowed rapid quantification of different concentrations of maltitol and fructose. This sensor array for saccharides is expected to become a promising alternative tool for food monitoring. The link between anthocyanin and saccharide detection opened a new guiding direction for the application of anthocyanins in foods.     

Assessment of the potential bactericide effect of self‐cleaning floors: a proposed protocol

The antibacterial properties of self‐cleaning coatings are based on bactericide nanoparticles (NPs). Ecotoxicity of these NPs have been assessed mostly in suspension, using standard bioassays. Here a protocol is proposed to test actual coating samples, using the Vibrio fischeri bioluminescence inhibition bioassay. The protocol was designed to test bactericide properties of specially coated PVC floors being used in hospital environments under quasinatural conditions, such as prolonged exposure or room temperature. To take into consideration that the light output of the bacteria under prolonged exposure naturally changes, a correction factor is proposed.     

Molten salt synthesis and luminescence of Dy3+‐doped Y3Al5O12 phosphors

Dy³⁺‐doped Y₃Al₅O₁₂ phosphors were prepared at a relatively low temperature using molten salt synthesis. The phase of the prepared Dy³⁺‐doped Y₃Al₅O₁₂ phosphors was confirmed using X‐ray powder diffraction. Results indicated that Dy³⁺ doping did not change the Y₃Al₅O₁₂ phase. Following excitation at 352 nm, emission spectra of the Dy³⁺‐doped Y₃Al₅O₁₂ phosphors consisted of blue, yellow, and red emission bands. The influence of Dy³⁺ concentration and excitation wavelength on emission was investigated. The ratio of yellow light to blue light varied with change in Dy³⁺ doping concentration, due to changes in the structure around Dy³⁺. Emission intensities also changed when the excitation wavelength was changed. This variation is luminescence generated a system for tunable white light for Dy³⁺‐doped Y₃Al₅O₁₂ phosphors.     

Genetically Encoded FRET Biosensor Detects the Enzymatic Activity of Prostate-Specific Antigen

Prostate cancer is the most common cancer among men beyond 50 years old, and ranked the second in mortality. The level of Prostate-specific antigen (PSA) in serum has been a routine biomarker for clinical assessment of the cancer development, which is detected mostly by antibody-based immunoassays. The proteolytic activity of PSA also has important functions. Here a genetically encoded biosensor based on fluorescence resonance energy transfer (FRET) technology was developed to measure PSA activity. In vitro assay showed that the biosensor containing a substrate peptide ‘RLSSYYSGAG’ had 400% FRET change in response to 1 µg/ml PSA within 90 min, and could detect PSA activity at 25 ng/ml. PSA didn’t show enzymatic activity toward the biosensor in serum solution, likely reflecting the existence of other inhibitory factors besides Zn2+. By expressing the biosensor on cell plasma membrane, the FRET responses were significant, but couldn’t distinguish well the cultured prostate cancer cells from non-prostate cancer cells under microscopy imaging, indicating insufficient speci- ficity to PSA. The biosensor with the previously known ‘HSSKLQ’ substrate showed little response to PSA in solution. In summary, we developed a genetically encoded FRET biosensor to detect PSA activity, which may serve as a useful tool for relevant applications, such as screening PSA activation substrates or inhibitors; the purified biosensor protein can also be an alternative choice for measuring PSA activity besides currently commercialized Mu-HSSKLQ-AMC substrate from chemical synthesis.     

A cost–benefit analysis of the environmental taxation policy in China: A frontier analysis‐based environmentally extended input–output optimization method

China's high‐speed economic development and reliance on overconsumption of natural resources have led to serious environmental pollution. Environmental taxation is seen as an effective economic tool to help mitigate air pollution. In order to assess the effects of different scenarios of environmental taxation policies, we propose a frontier‐based environmentally extended input–output optimization model with explicit emission abatement sectors to reflect the inputs and benefits of abatement. Frontier analysis ensures policy scenarios are assessed under the same technical efficiency benchmark, while input–output analysis depicts the wide range of economic transactions among sectors of an economy. Four scenarios are considered in this study, which are increasing specific tax rates of SO₂, NO_x, and soot and dust separately and increasing all three tax rates simultaneously. Our estimation results show that: raising tax rates of SO₂, NO_x, and soot and dust simultaneously would have the highest emission reduction effects, with the SO₂ tax rate making the greatest contribution to emission reduction. Raising the soot and dust tax rate is the most environmentally friendly strategy due to its highest abatement to welfare through avoided health costs. The combination of frontier analysis and input–output analysis provides policy makers a comprehensive and sectoral approach to assess costs and benefits of environmental taxation.     

Review: Helicobacter pylori infection in children

Helicobacter pylori infection in children and adolescents differs in comparison to adults with respect to epidemiology, host responses, and disease manifestations. Furthermore, treatment options are limited in this population and antibiotic resistance rates continue to increase. Therefore, ongoing research is vital to understand disease pathogenesis and provide optimal management of children with infection. This review summarizes relevant publications from April 2019 to March 2020. Similar to adults, recent studies show a decreasing prevalence of infection in the pediatric population. Studies of pathogenesis investigated serum immune responses and the potential inverse association of infection and allergy. Several studies investigated the effect of H pylori and related inflammation on the gut microbiome. The recommendation of endoscopy‐based testing to identify the cause of symptoms and not just H pylori, reserving noninvasive UBT or stool antigen tests for post‐eradication follow‐up, was supported by the current literature.