Laser Interference Lithography for the Nanofabrication of Stimuli‐Responsive Bragg Stacks

Dynamic structural coloration in Tmesisternus isabellae beetle elytra is a unique example of Bragg stack‐based wavelength tuning in response to external stimuli. The underlying principles could guide the design of quantitative optical stimuli‐responsive polymers. Existing nanofabrication techniques to create such materials are costly, time‐consuming, and require high expertise. This study reports a nanofabrication method to produce slanted Bragg stack structures in poly(acrylamide‐co‐poly(ethylene glycol) diacrylate) hydrogel films by combining laser interference lithography and silver halide chemistry in a cost‐effective and rapid process (≈10 min). The Bragg stacks consist of silver bromide nanocrystal multilayers having a lattice spacing of ≈200 nm. Upon broadband light illumination, the Bragg stacks diffract a narrow‐band peak at 520 nm at ≈10° with respect to the normal incidence. The lattice spacing of the hydrogel films can be modulated by external stimuli to shift the Bragg peak for dynamic quantitative measurements. To demonstrate the utility of this method, the Bragg stacks are functionalized with phenylboronic acid molecules. Bragg peak shift analysis allows reversible glucose sensing within a physiological dynamic range (0.0–20.0 mmol L^?1) having a sensitivity of 0.2 mmol L^?1. The developed Bragg stacks may have application in portable, wearable, and implantable real‐time medical diagnostics at point‐of‐care settings.     

Repositioning the Substrate Activity Screening (SAS) Approach as a Fragment‐Based Method for Identification of Weak Binders

Fragment‐based drug discovery (FBDD) has evolved into an established approach for “hit” identification. Typically, most applications of FBDD depend on specialised cost‐ and time‐intensive biophysical techniques. The substrate activity screening (SAS) approach has been proposed as a relatively cheap and straightforward alternative for identification of fragments for enzyme inhibitors. We have investigated SAS for the discovery of inhibitors of oncology target urokinase (uPA). Although our results support the key hypotheses of SAS, we also encountered a number of unreported limitations. In response, we propose an efficient modified methodology: “MSAS” (modified substrate activity screening). MSAS circumvents the limitations of SAS and broadens its scope by providing additional fragments and more coherent SAR data. As well as presenting and validating MSAS, this study expands existing SAR knowledge for the S1 pocket of uPA and reports new reversible and irreversible uPA inhibitor scaffolds.     

Ovarian stimulation with FSH reduces phosphorylation of gonadotrope progesterone receptor and LH secretion in the rat

Administration of human FSH (hFSH) to cyclic rats during the dioestrous phase attenuates progesterone receptor (PR)-dependent events of the preovulatory LH surge in pro-oestrus. The increased bioactivity of the putative ovarian gonadotropin surge inhibiting/attenuating factor induced by hFSH treatment is not associated with a decrease in PR protein expression, and the possibility of its association at a PR posttranslational effect has been raised. The present experiments aimed to analyse PR phosphorylation status in the gonadotrope of rats with impaired LH secretion induced by in vivo hFSH injection. Two experimental approaches were used. First, incubated pro-oestrous pituitaries from hFSH-injected cycling and oestrogen-treated ovariectomized (OVX) rats were used to analyze the effect of calyculin, an inhibitor of intracellular phosphatases, on PR-dependent LH release, which was measured in the incubation medium by RIA. Second, pituitaries taken from hFSH-injected intact cycling and OVX rats and later incubated with P or GNRH1 were used to assess the phosphorylation rate of gonadotrope. The latter was analysed in formalin-fixed, paraffin-embedded tissue sections by immunohistochemistry using a MAB that recognizes the phosphorylated (p) form of PR at Ser294. Calyculin reduced the ovary-mediated inhibition of hFSH in GNRH1-stimulated LH secretion. In addition, the immunohistochemical expression of pSer294 PR was significantly reduced after ovarian stimulation with hFSH in pituitaries from pro-oestrous rats incubated with P or GNRH1. Altogether, these results suggested that the ovarian-dependent inhibitory effect of FSH injection on the preovulatory LH secretion in the rat may involve an increase in dephosphorylation of PR.     

MAEBL Contributes to Plasmodium Sporozoite Adhesiveness

The sole currently approved malaria vaccine targets the circumsporozoite protein—the protein that densely coats the surface of sporozoites, the parasite stage deposited in the skin of the mammalian host by infected mosquitoes. However, this vaccine only confers moderate protection against clinical diseases in children, impelling a continuous search for novel candidates. In this work, we studied the importance of the membrane-associated erythrocyte binding-like protein (MAEBL) for infection by Plasmodium sporozoites. Using transgenic parasites and live imaging in mice, we show that the absence of MAEBL reduces Plasmodium berghei hemolymph sporozoite infectivity to mice. Moreover, we found that maebl knockout (maebl-) sporozoites display reduced adhesion, including to cultured hepatocytes, which could contribute to the defects in multiple biological processes, such as in gliding motility, hepatocyte wounding, and invasion. The maebl- defective phenotypes in mosquito salivary gland and liver infection were reverted by genetic complementation. Using a parasite line expressing a C-terminal myc-tagged MAEBL, we found that MAEBL levels peak in midgut and hemolymph parasites but drop after sporozoite entry into the salivary glands, where the labeling was found to be heterogeneous among sporozoites. MAEBL was found associated, not only with micronemes, but also with the surface of mature sporozoites. Overall, our data provide further insight into the role of MAEBL in sporozoite infectivity and may contribute to the design of future immune interventions.     

Optimal green tax reforms yielding double dividend

In an stylized endogenous growth economy with a negative externality created by CO2 emissions and in which abatement activities are made by private firms, we find a wide range of dynamically feasible green tax reforms yielding the double dividend without any need to assume a complex production structure or tax system, or a variety of externalities in production. As a remarkable finding, we obtain certain scenarios in which increasing the emissions tax up to the Pigouvian level and removing completely the income tax is dynamically feasible and, also, it is the second-best reform. Hence, as a difference to previous literature, in these scenarios the first-best tax mix is implementable, allowing for the elimination of both environmental and non-environmental inefficiencies. Our result arises because of the consideration of public debt issuing and the management of the government budget balance with an intertemporal perspective. The result is obtained for an intermediate range of environmental bearing in preferences, the valid range being contingent on the pre-existing income tax rate. The type of tax reform that we propose could also be implemented for different energy taxes.     

EXTRACTION OF IRON(II) BY 2-(2'-THIAZOLYLAZO)-4,6-DIMETHYLPHENOL AND 2-(4',5'-DIMETHYL-2'-THIAZOLYLAZO)-4,6-DIMETHYLPHENOL

The extraction of Fe(II) from 0.1M NaClO₄. by 2-(2'-thiazolylazo)-4,6-dimethylphenol (TADMP) and 2-(4 ', 5'-dimethy1-2’-thiazolylazo)-4,6-dimethylphenol (DMTADMP) dissolved in chloroform has been studied by distribution methods. The experimental data, treated by both graphical and numerical methods, may be explained by assuming the formation of the species FeRClO₄. (logK₁₀₁₁ = 7.58±0.09 and 9.58±0.10) and FeR₂ logK₁₀₂₀. = 14.31±0.22 and 15.32±0.18) for Fe(II)-TADMP and Fefll)-DMTADMP systems, respectively.     

Chemical composition,bioactive compounds extraction,and observed biological activities from jussara (Euterpe edulis): The exotic and endangered Brazilian superfruit

In this article, we reviewed studies on the fruits of the jussara palm (Euterpe edulis Martius), an endangered Brazilian Atlantic Forest palm tree, also coined as “Superfruit.” We summarized the chemical components of the pulp and observed biological activities in murine and humans, as well as the best practices involving the extraction of its target compounds, bioavailability, and stability of extracts. Jussara has shown a rich phenolic profile that justifies its antioxidant properties, in addition to a considerable lipidic and energetic value. As the main feature, the fruit possesses large amounts of anthocyanins that can be commercially explored as a food additive or cosmetic colorants. Recent studies emphasized jussara's antioxidant, anti-inflammatory, and cardioprotective capabilities via reshaping of the gut microbiota. Further knowledge is needed to establish bioavailability and optimal serving size, as many of its antioxidant compounds go under chemical bioconversion in the intestinal tract. While extraction of phenolic compounds, anthocyanins, and oils have interesting results, more studies are required in order to reduce the use of conventional organic solvents and improve their stability and shelf life when added to food products, an area in which nanotechnology seems promising.