Creating sustainable, resilient, and livable cities calls for integrative approaches and collaborative practices across temporal and spatial scales. However, practicability is challenged by ...institutional, social, and technical complexities and the need to build collective understanding of integrated approaches. Rapid urbanization along the United States-Mexico border, fueled by industrialization, trade, and migration, has resulted in cities confronted with recurrent flooding risk, extended drought, water pollution, habitat destruction and systemic vulnerabilities. The international border, which separates natural and built ecosystems, is both a challenge and an opportunity, making a unique social and institutional setting ideal for testing the integration of urban planning and water management. Our research focuses on fusing multi-functional and multi-scalar green infrastructure to restore ecosystem services through a strategic binational planning process. This paper describes this planning process, including the development and application of both a land suitability analysis and a hydrological model to optimally site green infrastructure in the Nogales, Arizona, United States—Nogales, Sonora, Mexico, cross border region. We draw lessons from this process and stakeholder feedback focused on the potential for urban green infrastructure, to allow for adaptation and even transformation in the face of current and future challenges such as limited resources, underdeveloped governance, bordering, and climate change. In sum, a cross border network of green infrastructure can provide a backbone to connect this transboundary watershed while providing both hydrological and social benefits.
The use of trace elements such as iodine and selenium in agriculture is gaining great importance due to the benefits in plants before different types of biotic or abiotic stress. This research aimed ...to evaluate the seedling root priming with Na2SeO3 (0, 0,5, 1, 2, 3 mg L-1) and KIO3 (0, 100, 150, 200, 250 mg L-1) on the antioxidant compounds of tomato (Solanum lycopersicum L.) fruits and leaves. The crop was established under greenhouse conditions in 10-L polyethylene containers containing peat moss and perlite 1:1 (v/v), in a randomized complete block experimental design with a 52 factorial arrangement. In the fruits, the Na2SeO3 influenced the GHS, flavonoids, lycopene and β-carotene contents, while the KIO3 influenced the GHS, vitamin C and lycopene contents. The KIO3-Na2SeO3 interactions affected the GSH, phenols, flavonoids, lycopene and β-carotene contents in fruits. In the leaves the GHS content increased with the Na2SeO3, while the GSH, flavonoids, and chlorophyll contents increased with the KIO3 factor and KIO3-Na2SeO3 interactions. The evaluated enzymes in fruits and leaves decreased with the both the KIO3 and Na2SeO3 concentrations. The Na2SeO3 influenced the hydrophilic compounds by ABTS and DPPH, while the KIO3 influenced the hydrophilic compounds by ABTS. In the leaves, the KIO3 influenced the lipophilic compounds by ABTS. The KIO3-Na2SeO3 interactions influenced the hydrophilic compounds by ABTS in both the fruits and leaves. Seedling root imbibition in KIO3 and Na2SeO3 is a method that implemented in the tomato crop presents interesting aspects in the increase of the antioxidant capacity and the non-enzymatic compounds, such as vitamin C, phenols, flavonoids and GSH contents. However, this method presented an inhibition in the antioxidant enzymes.
The use of trace elements in agriculture as a complement to crop fertilization programs is a practice that is gaining importance and relevance worldwide. Iodine and selenium perform essential ...functions in human health, related to the proper functioning of the thyroid gland, acting as antioxidants and antiproliferatives, and their limited intake through food consumption can cause malnutrition, reflected in the abnormal development and growth of humans. This research aimed to evaluate the nutraceutical quality of tomato (
L.) in response to seed priming based on KIO
(0, 100, 150, 200, 250 mg L
) and Na
SeO
(0, 0.5, 1, 2, 3 mg L
), performed by interaction from a 5
-factorial design and by independent factors in a 24-h imbibition time. The tomato crop was established under greenhouse conditions in 10-L polyethylene containers containing peat moss and perlite 1:1 (
/
). Regarding non-enzymatic antioxidant compounds, lycopene, β-carotene and flavonoid contents in tomato fruits significantly increased with KIO
and Na
SeO
treatments; however, vitamin C content was negatively affected. KIO
increased the phenol and chlorophyll-
contents of leaves. In relation to enzymatic activity, KIO
positively influenced GSH content and PAL activity in tomato fruits. KIO
also positively influenced GSH content in leaves while negatively affecting PAL and APX activities. Na
SeO
favored GSH content and GPX activity in tomato fruits and leaves. Na
SeO
negatively affected the antioxidant capacity of hydrophilic compounds by ABTS in fruits and leaves and favored hydrophilic compounds by DPPH in leaves. Seed imbibition based on KIO
and Na
SeO
is a method that is implemented in the tomato crop and presents interesting aspects that favor the nutraceutical quality of tomato fruits, which may contribute to increasing the intake of these minerals in humans through tomato consumption.
Controlling the chemistry on the surface of new carbon materials is a key factor to widen the range of their applicability. In this paper we show a grafting methodology of polyalkylamines to the ...surface of carbon nanomaterials, in particular, carbon nanotubes and a carbon black. The aim of this work is to reach large degrees of covalent functionalization with hyperbranched polyethyleneimines (HBPEIs) and to efficiently preserve the strong chelating properties of the HBPEIs when they are fixed to the surface of these carbon materials. This functionalization opens new possibilities of using these carbon nanotubes-based hybrids. The results show that the HBPEIs are covalently attached to the carbon materials, forming hybrids. These hybrids emerge from the reaction of amine functions of the HBPEIs with carbonyls and carboxylic anhydrides of the carbon surface which become imine and imide bonds. Thus, due to the nature of these bonds, the pre-oxidized samples with relevant number of C=O groups showed an increase in the degree of functionalization with the HBPEIs. Furthermore, both the acid-base properties and the coordination capacity for metal ions of the hybrids are equivalent to that of the free HBPEIs in solution. This means that the chemical characteristics of the HBPEIs have been efficiently transferred to the hybrids. To reach this conclusion we have developed a novel procedure to assess the acid-base and the coordination properties of the hybrids (solids) by means of potentiometric titration. The good agreement of the values obtained for the hybrids and for the free HBPEIs in aqueous solution supports the reliability of the procedure. Moreover, the high capacity of the hybrids to capture Ni
2+
by complexation opens new possibilities of using these hybrids to capture high-value metal ions such as Pd
2+
and Pt
2+
.
Hyperbranched polyethylenimines are covalently fixed to the surface of carbon materials, so the chemical characteristics of the amines are transferred to the hybrid materials.
Porous pillared graphene oxide (GO) materials were prepared using solvothermal reaction of Hummers GO with solution of Tetrakis(4-aminophenyl)methane (TKAm) in methanol. The intercalation of TKAm ...molecules between individual GO sheets, performed under swelling condition, results in expansion of inter-layer distance of GO from ∼7.5 Å to 13-14 Å. Pillaring GO with bulky, rigid 3D shaped TKAm molecules could be an advantage for the preparation of stable pillared structures compared to e.g. aliphatic or aromatic diamines. Insertion of TKAm molecules into inter-layer space of GO results in formation of interconnected network of sub-nanometer slit pores. The expanded GO structure prepared with optimized GO/TKAm composition shows Specific Surface Area (SSA) up to 660 m2/g which is among the highest reported for GO materials pillared using organic spacers. Modelling of GO structures pillared with TKAm molecules shows that maximal SSA of about 2300 m2/g is theoretically possible for realistic concentration of pillaring molecules in GO interlayers. Hydrogen sorption by pillared GO/TKAm is found to follow standard correlation with SSA both at ambient and liquid nitrogen temperatures with highest uptakes of 1.66 wt% achieved at 77 K and 0.25 wt% at 295 K. Our theoretical simulations show that pillared GO structures do not provide improvement of hydrogen storage beyond well-established physisorption trends even for idealized materials with subnanometer pores and SSA of 2300–3700 m2/g.
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This paper reports a new method to obtain ultra-small Pd and Pt nanoparticles (0.5-1 nm) supported on multi-walled carbon nanotubes (MWCNTs). Even at high loadings of both metals (22.3 and 31.5% ...(wt/wt) of Pd
2+
and Pt
2+
, respectively), very narrow and unimodal particle size distributions are achieved. The complexing capabilities of polyethyleneimine covalently attached to the surface of the tubes are optimal for the retention of Pd
2+
and Pt
2+
from solution. We have addressed the reduction of the retained ions by two approaches: a classical treatment with NaBH
4
in aqueous solution, and a novel method using hydrogen cold plasma to preserve the structural features of the material. Cold plasma produced degrees of reduction similar or even larger than NaBH
4
, supporting the advantage of hydrogen cold plasma as reducing agent as it is a simple, clean and fast (15 minutes) procedure. XPS analysis of the reduced materials show an increase in the electron density near the Fermi level. Pt/MWCNT materials have been tested as anode for methanol electrooxidation, showing a catalytic profile typical of that observed for platinum nanoparticles. The stability after 1000 cycles of the plasma-reduced materials is much larger than these reported for Pt/carbon materials, indicating the stability of the ultra-small nanoparticles.
This paper reports a new method to obtain ultra-small Pd and Pt nanoparticles (0.5-1 nm) supported on multi-walled carbon nanotubes (MWCNTs).
Correction for 'ATP dephosphorylation can be either enhanced or inhibited by pH-controlled interaction with a dendrimer molecule' by Carla Bazzicalupi
et al., Chem. Commun.
, 2015,
51
, 3907-3910.
The selective functionalization of carbon nanotube surfaces is crucial for many potential applications of these materials. For this purpose several oxidants, among other substances, are used. The aim ...is to reach a large degree of functionalization which depends on the oxidant character of the reagent. For this reason the functionalization of multiwall carbon nanotubes (MWCNTs) by treatment with ozone in basic solution is studied. At basic pHs, ozone results into hydroxyl radicals whose reduction potential is very high (E° = 3.06 V). The results have been compared to those obtained by ozone in gas phase and with cold oxygen plasma. The oxidation with ozone in basic solution seems to be kinetically restricted. As a consequence, the degree of oxidation in this medium is smaller than this of ozone gas, in spite of the larger oxidation capacity of the former. The oxygen-containing groups fixed by these two treatments are mainly attached to defects of the nanotubes. Moreover, no modification of the graphene layers and no porosity result from these treatments. The oxygen plasma treatment stands out in the content of oxygen groups fixed to the MWCNTs, as it is by far more effective, although some of these groups have relatively low thermal stability. Nevertheless, this treatment mainly fixes the oxygen groups on the walls of the nanotubes.
•We have developed a simple model for T2DM prediction based on basic parameters.•Higher FPG levels represent greater risk of incident T2DM in the next years. In intermediate FPG values, age ...determines T2DM risk and BMI in a second step.•In individuals with lower FPG, higher FTGs increases risk of developing T2DM. The present model correctly classified 93.5% of individuals.
To develop a simple multivariate predictor model of incident type 2 diabetes in general population.
Participants were recruited from the Spanish Di@bet.es cohort study with 2570 subjects meeting all criteria to be included in the at-risk sample studied here. Information was collected using an interviewer-administered structured questionnaire, followed by physical and clinical examination. CHAID algorithm, which collects the information of individuals with and without type 2 diabetes, was used to develop a decision tree based type 2 diabetes prediction model.
156 individuals were identified as having developed type 2 diabetes (6.5% incidence). Fasting plasma glucose (FPG) at the beginning of the study was the main predictive variable for incident type 2 diabetes: FPG ≤ 92 mg/dL (ref.), 92–106 mg/dL (OR = 3.76, 95%CI = 2.36–6.00), > 106 mg/dL (OR = 13.21; 8.26–21.12). More than 25% of subjects starting follow-up with FPG levels > 106 mg/dL developed type 2 diabetes. When FPG <106 mg/dL, other variables (fasting triglycerides (FTGs), BMI or age) were needed. For levels ≤ 92 mg/dL, higher FTGs levels increased risk of incident type 2 diabetes (FTGs > 180 mg/dL, OR = 14.57; 4.89–43.40) compared with the group of FTGs ≤ 97 mg/dL (FTGs = 97–180 mg/dL, OR = 3.12; 1.05–9.24). This model correctly classified 93.5% of individuals.
The type 2 diabetes prediction model is based on FTGs, FPG, age, gender, and BMI values. Utilizing commonly available clinical data and a simple blood test, a simple tree diagram helps identify subjects at risk of developing type 2 diabetes, even in apparently low risk subjects with normal FPG.
Hyperbranched poly(ethyleneimine) (HBPEI) molecules in solution present high capacity to form stable complexes with transition metal ions due to the large number of amino groups ready to form ...chelates. We grafted HBPEI molecules to a multi-walled carbon nanotube (MWCNT) surface through covalent bonding, preparing solid hybrids which retain the chemical properties of the free poly-alkylamine molecules. In this way, we are able to transfer the complexation capacity of such molecules to a solid material adequate to act as a high-capacity sorbent for metal transition ions. We tested the HBPEI/MWCNT hybrids for the retention of Pd 2+ and Pt 2+ and the retention values obtained are much larger than those previously reported with fast retention kinetics. The kinetics and the XPS analysis of the metal ion/HBPEI/MWCNT ensemble indicate that the retention takes place through the formation of chelates with two or three nitrogen atoms and with Cl − anions as co-ligands. Moreover, the results allow us to tune the metal loading on the hybrids by controlling the solution conditions. This is important because the XPS valence band analysis demonstrates that metal complexation directly modifies the electronic behaviour of the carbon nanotubes, which supports the stable covalent bond between HBPEI molecules and MWCNT and opens the possibility for tuning the electronic properties of the tubes.
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