Facile fabrication of nickel nanostructures on a copper-based template via a galvanic replacement reaction in a deep eutectic solvent

We describe an unusual galvanic replacement process for facile synthesis of nickel nanostructures by using Cu as a sacrificial template in a deep eutectic solvent (DES), ethaline. This replacement process occurred through a galvanic exchange of [NiCl4]2 − ions in ethaline at 353 K with an immersed Cu substrate, which acted as both reactive template and reductant. The mechanism for this replacement reaction and the morphology and topography evolution process of the nickel nanostructures were investigated. This facile preparation method performed in ethaline provides a novel way to fabricate nickel nanostructures with particulate or porous architecture on a copper-based template

Facile fabrication of nickel nanostructures on a copper-based template via a galvanic replacement reaction in a deep eutectic solvent

We describe an unusual galvanic replacement process for facile synthesis of nickel nanostructures by using Cu as a sacrificial template in a deep eutectic solvent (DES), ethaline. This replacement process occurred through a galvanic exchange of [NiCl4]2 − ions in ethaline at 353 K with an immersed Cu substrate, which acted as both reactive template and reductant. The mechanism for this replacement reaction and the morphology and topography evolution process of the nickel nanostructures were investigated. This facile preparation method performed in ethaline provides a novel way to fabricate nickel nanostructures with particulate or porous architecture on a copper-based template

Fighting against kidney diseases with small interfering RNA: opportunities and challenges

The significant improvements in siRNA therapy have been achieved, which have great potential applications in humans. The kidney is a comparatively easy target organ of siRNA therapy due to its unique structural and functional characteristics. Here, we reviewed recent achievements in siRNA design, delivery and application with focuses on kidney diseases, in particular kidney transplant-related injuries. In addition, the strategy for increasing serum stability and immune tolerance of siRNA was also discussed. At last, the future challenges of siRNA therapy including organ/tissue/cell-specific delivery and time-controlled silence, as well as selecting therapeutic targets, were addressed as well

Terrestrial support of pelagic consumers: patterns and variability revealed by a multilake study

1. Lake food webs can be supported by primary production from within the lake, organic matter imported from the catchment or some mixture of these two sources. Generalisations about food-web subsidies to lake ecosystems are often based on data from only a few ecosystems and therefore do not consider the potential variability of subsidies among diverse ecosystems in a landscape. 2. We measured the variation among lake ecosystems in terrestrial (allochthonous) utilisation by pelagic consumers and developed models to describe the variability. Stable isotope ratios of hydrogen and carbon were measured for Chaoborus spp. and crustacean zooplankton taxa in 40 lakes to quantify consumer allochthonous resource use (allochthony). 3. The median fraction of consumer allochthony estimated using a two-source Bayesian mixing model varied between 4 and 82% (mean among all lakes = 36%) for Chaoborus sp. among lakes and between 1 and 76% in a more limited sample of crustacean zooplankton consumers. The degree of allochthonous resource use increased linearly with the availability of allochthonous resources. 4. Terrestrial support of Chaoborus was correlated (using best fitting relationships) with covariates for lake organic matter sources including dissolved inorganic carbon, total phosphorus, chlorophyll α, colour and catchment area. However, the most parsimonious model was an inverse relationship between lake surface area and consumer allochthony, indicating that allochthonous subsidies are more important in smaller than larger systems. Given the preponderance of small waterbodies, allochthonous subsidies are important in a large number of lake ecosystems

Characterization of an aerosol generation system to assess inhalation risks of aerosolized nano-enabled consumer products

Objective: The aerosolization of common nano-enabled consumer products such as cosmetics has significantly increased engineered nanoparticle inhalation risks. While several studies have investigated the impact of cosmetic dermal exposures, inhalation hazards of aerosolized cosmetics are much less known but could pose considerable harm to users due to potential co-exposure of nanoparticles and other product components. Materials and Methods: In this study, we developed a fully automated aerosol generation system to examine the aerosol properties of four aerosolized nano-enabled cosmetics using real-time monitoring and sampling instrumentation. Physicochemical characterization of aerosols was conducted using scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (SEM-EDX). Characterization and calibration of animal exposure pods coupled to the system were also performed by measuring and comparing particle concentrations between pods. Results and Discussion: Results show peak emissions are shade dependent and varied between 12,000–22,000 particles/cm3 with modal diameters ranging from 36 nm–1.3 µm. SEM-EDX analysis determined that the original products and collected aerosols have similar morphological features consisting of micron-sized particles decorated with nanoparticles and crystalline structures. Mean total particle concentration in pods at 5 and 10 mg/m3 target levels were 2.22E + 05 #/cm3 and 4.33E + 05 #/cm3, respectively, with Conclusions: The fully automated exposure platform described herein provides reproducible aerosol generation, conforms to recommended guidelines on chemical testing, and therefore is suitable for future in vivo toxicological assessments to examine potential respiratory hazards of aerosolized nano-enabled consumer products.</p

Assigning hydrogen, carbon, and nitrogen isotope values for phytoplankton and terrestrial detritus in aquatic food web studies

Studies designed to assess the resources supporting aquatic consumers using stable isotope analysis require measurements of the potential end members (basal resources). While some basal resources are easily measured, it is often difficult to physically separate phytoplankton (one potential end member) from other components in seston. Further, terrestrial materials entering aquatic ecosystems undergo diagenetic change, potentially altering isotope composition and making it difficult to assign end member values. We tested techniques for determining the isotopic hydrogen (δ 2 H), carbon (δ 13 C), and nitrogen (δ 15 N) values of terrestrial and phytoplankton end members in seston. Long term in situ leaf decomposition experiments were performed. No appreciable change was found in the isotope values of degraded material (mean change 3.6‰ for δ 2 H, 0.0‰ for δ 13 C, and −0.1‰ for δ 15 N). We conclude that the isotope values of terrestrial plant material can be used to assign end members for terrestrial detritus. Using samples collected from 10 lakes with phytoplankton-dominated seston, we compared 3 published methods for estimating the δ 13 C and δ 15 N of phytoplankton. One method, which corrected bulk particulate organic matter (POM) isotope values based on a δ 2 H mixing model, accurately predicted measured phytoplankton δ 13 C. Another method, which used a C:N mixing model to correct bulk POM, also performed well. A new method, proposed here, modified seston isotope values using the difference in C:N of phytoplankton and terrestrial material in a δ 2 H mixing model and correctly predicted measured phytoplankton δ 15 N. We recommend estimating phytoplankton δ 13 C and δ 15 N by correcting bulk POM using a δ 2 H mixing model, with the C:N modification proposed here for δ 15 N

<i>VDR</i> gene <i>Apa</i>I polymorphism and risk of postmenopausal osteoporosis: a meta-analysis from 22 studies

The ApaI polymorphism (G > T, rs7975232) of the vitamin D receptor (VDR) gene in the risk of postmenopausal osteoporosis has been widely researched, and the results have yielded conflicts. Therefore, we performed an updated pooled analysis to comprehensively assess the association between VDR ApaI polymorphism and postmenopausal osteoporosis risk. We searched eligible studies about ApaI polymorphism and osteoporosis through the PubMed, Embase, CNKI and Wanfang databases; case–control studies containing available genotype frequencies of A/a were chosen. We used the odds ratio with 95% confidence interval to assess the strength of this association. Sensitivity analysis and publication bias assessment were performed. Trial sequential analysis (TSA) was performed to evaluate a sufficient sample. Twenty-two studies assessed the relationship between ApaI polymorphism and the risk of osteoporosis in postmenopausal women. The comprehensive analyses showed no significant association for ApaI polymorphism with postmenopausal osteoporosis in the overall population, equally valid for Asian and Caucasian subgroups with any genetic model. TSA still indicated the results were robust. The present meta-analysis suggests that the VDR ApaI genotype may not affect the risk of postmenopausal osteoporosis in Asians and Caucasians.</p

Interferometric speckle visibility spectroscopy (ISVS) for human cerebral blood flow monitoring

Infrared light scattering methods have been developed and employed to non-invasively monitor human cerebral blood flow (CBF). However, the number of reflected photons that interact with the brain is low when detecting blood flow in deep tissue. To tackle this photon-starved problem, we present and demonstrate the idea of interferometric speckle visibility spectroscopy (ISVS). In ISVS, an interferometric detection scheme is used to boost the weak signal light. The blood flow dynamics are inferred from the speckle statistics of a single frame speckle pattern. We experimentally demonstrated the improvement of measurement fidelity by introducing interferometric detection when the signal photon number is insufficient. We apply the ISVS system to monitor the human CBF in situations where the light intensity is $\sim$100-fold less than that in common diffuse correlation spectroscopy (DCS) implementations. Due to the large number of pixels ($\sim 2\times 10^5$) used to capture light in the ISVS system, we are able to collect a similar number of photons within one exposure time as in normal DCS implementations. Our system operates at a sampling rate of 100 Hz. At the exposure time of 2 ms, the average signal photon electron number is $\sim$0.95 count/pixel, yielding a single pixel interferometric measurement signal-to-noise ratio (SNR) of $\sim$0.97. The total $\sim 2\times 10^5$ pixels provide an expected overall SNR of 436. We successfully demonstrate that the ISVS system is able to monitor the human brain pulsatile blood flow, as well as the blood flow change when a human subject is doing a breath holding task

Sodium selenite inhibits leukemia HL-60 cell proliferation and induces cell apoptosis by enhancing the phosphorylation of JNK1 and increasing the expression of p21 and p27

Selenium is an essential trace element and has shown chemopreventive or therapeutic activities on human solid cancers; however, whether it has anticancer effects on leukemia has not yet been elucidated. The present study was designed to determine the role of selenium on HL-60 human promyelocytic leukemia cells. We found that 100 nM of sodium selenite (Se) had no significant effects on cell proliferation, apoptosis and the cell cycle; however, a higher concentration of 250 nM of Se significantly inhibited cell proliferation, promoted apoptosis and induced cell cycle arrest at the S phase after 48 h of treatment (P<0.05), thus demonstrating the anticancer activities of selenium in leukemia. However, the decrease in c-Jun NH2-terminal kinase 1 (JNK1) expression by targeting JNK1 using small interfering RNA attenuated the inhibitory effects of Se on cell proliferation and the induction of apoptosis. Mechanistic studies showed that the anticancer activities of Se were associated with the enhanced phosphorylation of JNK1 and the increased expression of the cell cycle regulators, p21 and p27, as well as the downregulation of cyclin D1. Our data provide further evidence that the appropriate concentration of selenium has therapeutic potential in leukemia

Sodium selenite inhibits leukemia HL-60 cell proliferation and induces cell apoptosis by enhancing the phosphorylation of JNK1 and increasing the expression of p21 and p27

Selenium is an essential trace element and has shown chemopreventive or therapeutic activities on human solid cancers; however, whether it has anticancer effects on leukemia has not yet been elucidated. The present study was designed to determine the role of selenium on HL-60 human promyelocytic leukemia cells. We found that 100 nM of sodium selenite (Se) had no significant effects on cell proliferation, apoptosis and the cell cycle; however, a higher concentration of 250 nM of Se significantly inhibited cell proliferation, promoted apoptosis and induced cell cycle arrest at the S phase after 48 h of treatment (P<0.05), thus demonstrating the anticancer activities of selenium in leukemia. However, the decrease in c-Jun NH2-terminal kinase 1 (JNK1) expression by targeting JNK1 using small interfering RNA attenuated the inhibitory effects of Se on cell proliferation and the induction of apoptosis. Mechanistic studies showed that the anticancer activities of Se were associated with the enhanced phosphorylation of JNK1 and the increased expression of the cell cycle regulators, p21 and p27, as well as the downregulation of cyclin D1. Our data provide further evidence that the appropriate concentration of selenium has therapeutic potential in leukemia