Inflammatory and hyperalgesic effects of oxidized multi-walled carbon nanotubes in rats.

We evaluated local inflammatory activity of oxidized multiwalled carbon nanotubes in rat experimental models of acute inflammation (paw edema and hyperalgesia) by analyzing their toxicity in non-mesoendothelial tissues. Subcutaneous injection of the nanotubes induced paw edema, that was maximal in the first 2 h after administration at 0.1 mg/kg (43.25 +/- 3.8 AUC) and 1 mg/kg (30.1 +/- 1.8 AUC) compared to saline (18.32 +/- 02.05 AUC). The histopathological analysis showed acute inflammation characterized by vasodilatation, edema formation, neutrophil infiltrate and tissue damage. The nanotubes also elicited hyperalgesic response, seen by the increase of animal paw withdrawal that was maximal in the first 3 hours. The data obtained at the 3rd h was: 75 +/- 9.3% (0.01 mg/kg), 58 +/- 8.3% (0.1 mg/kg) and 53 +/- 6.69% (1 mg/kg) in relation with saline (28 +/- 3.5%). In conclusion, the oxidized multiwalled carbon nanotubes elicit inflammatory and hyperalgesic effects associated to severe tissue damage in rats.

Discrimination and Latino Health: A Systematic Review of Risk and Resilience.

INTRODUCTION: As anti-immigrant hostility toward Latino populations grows, more fervent attention is needed to consider strength-based approaches to attenuate the effects of perceived discrimination. This systematic review synthesizes the evidence about the effects of racial/ethnic discrimination on mental, physical, and health behaviors of Latinos and examines the coping mechanisms and cultural factors that attenuate the negative association between discrimination and health among adult Latinos living in the United States. METHOD: The search criteria included articles that (a) examined ethnic/racial discrimination in relationship to a health outcome, (b) had study samples composed of least 25% Latino adults, and (c) were written in English. RESULTS: A total of 33 studies were included in the review. Our findings demonstrated the negative relationship between perceived discrimination, mental health, and health behaviors. The evidence for the relationship between perceived discrimination and physical health was less robust. For mental health, greater feeling of ethnic pride and belonging attenuated the negative relationship between perceived discrimination and mental health. CONCLUSIONS: Our findings highlight the potential for building on ethnic identity for addressing mental health and perceived discrimination. Future research directions are outlined to address identified gaps.

Association of Perceived Stress and Discrimination on Medication Adherence among Diverse Patients with Uncontrolled Hypertension.

Background: Uncontrolled hypertension is a significant risk factor for cardiovascular morbidity and mortality. In the United States, many patients remain uncontrolled, in part, due to poor medication adherence. Efforts to improve hypertension control include not only attending to medical management of the disease but also the social determinants of health, which impact medication adherence, and ultimately blood pressure control. Purpose: To determine which social determinants - health care access or community and social stressors - explain medication adherence. Methods: In this cross-sectional analysis, we used baseline data (N=1820, collected August 2017 to October 2019) from a pragmatic trial, which compares the effectiveness of a multi-level intervention including collaborative care and a stepped approach with enhanced standard of care for improving blood pressure. We used logistic regression analyses to examine the association between patient experiences of care and community and social stressors with medication adherence. Results: The participants represented a diverse sample: mean age of 60 years; 59% female; 57.3% Black, 9.6% Hispanic, and 33.2% White. All participants had a blood pressure reading ≥140/90 mm Hg (mean blood pressure - 152/85 mm Hg). Half of the participants reported some level of non-adherence to medication. Regression analysis showed that, compared with Whites, Blacks (AOR .47; 95% CIs: .37-.60, P<.001) and Hispanics (AOR .48; 95% CIs: .32- .73, P<.001) were less likely to report medication adherence. Also part-time workers (AOR .57; 95% CIs: .38-.86, P<.05), and those who reported greater perceived stress (AOR .94; 95% CIs: .91 - .98, P<.001) and everyday discrimination (AOR .73; 95% CIs: .59 - .89; P<.001) had lower odds of medication adherence. Among Blacks, greater perceived stress (AOR .93; 95% CIs: .88-.98, P<.001) and everyday discrimination (AOR .63; 95% CIs: .49 - .82, P<.005) were negatively associated with medication adherence. Among Hispanics, greater report of everyday discrimination (AOR .36; 95% CIs: .14 - .89, P<.005) was associated with lower odds of medication adherence. Among Whites, the negative effect of perceived stress on medication adherence was attenuated by emotional support. Conclusions: Using the social determinants of health framework, we identified associations between stress, everyday discrimination and medication adherence among non-Hispanic Blacks and Hispanics that were independent of health status and other social determinants. Programs to enhance self-management for African American and Hispanic patients with uncontrolled blood pressure should include a specific focus on addressing social stressors.

Raman evidence for pressure-induced formation of diamondene.

Despite the advanced stage of diamond thin-film technology, with applications ranging from superconductivity to biosensing, the realization of a stable and atomically thick two-dimensional diamond material, named here as diamondene, is still forthcoming. Adding to the outstanding properties of its bulk and thin-film counterparts, diamondene is predicted to be a ferromagnetic semiconductor with spin polarized bands. Here, we provide spectroscopic evidence for the formation of diamondene by performing Raman spectroscopy of double-layer graphene under high pressure. The results are explained in terms of a breakdown in the Kohn anomaly associated with the finite size of the remaining graphene sites surrounded by the diamondene matrix. Ab initio calculations and molecular dynamics simulations are employed to clarify the mechanism of diamondene formation, which requires two or more layers of graphene subjected to high pressures in the presence of specific chemical groups such as hydroxyl groups or hydrogens.The synthesis of two-dimensional diamond is the ultimate goal of diamond thin-film technology. Here, the authors perform Raman spectroscopy of bilayer graphene under pressure, and obtain spectroscopic evidence of formation of diamondene, an atomically thin form of diamond.

Structural and proactive safety aspects of oxidation debris from multiwalled carbon nanotubes.

The removal of oxidation debris from the oxidized carbon nanotube surface with a NaOH treatment is a key step for an effective functionalization and quality improvement of the carbon nanotube samples. In this work, we show via infrared spectroscopy and ultrahigh resolution and accuracy mass spectrometry that oxidation debris obtained from HNO(3)-treated multiwalled carbon nanotubes is a complex mixture of highly condensed aromatic oxygenated carbonaceous fragments. We have also evaluated their cytotoxicity by using BALB/c 3T3 mouse fibroblasts and HaCaT human keratinocytes as models. By knowing the negative aspects of dissolved organic carbon (DOC) to the water quality, we have demonstrated the removal of these carbon nanotube residues from the NaOH solution (wastewater) by using aluminium sulphate, which is a standard coagulant agent used in conventional drinking water purification and wastewater treatment plants. Our results contribute to elucidate the structural and proactive safety aspects of oxidation debris from oxidized carbon nanotubes towards a greener nanotechnology.