Rational design of large flat nitrogen-doped graphene oxide quantum dots with green-luminescence suitable for biomedical applications

Rational synthesis and simple methodology for the purification of large (35–45 nm in lateral size) and flat (1.0–1.5 nm of height) nitrogen-doped graphene oxide quantum dots (GOQDs) are presented. The methodology allows robust metal-free and acid-free preparation of N-GOQDs with a yield of about 100% and includes hydrothermal treatment of graphene oxide with hydrogen peroxide and ammonia. It was demonstrated that macroscopic impurities can be separated from N-GOQD suspension by their coagulation with 0.9% NaCl solution. Redispersible in water and saline solutions, particles of N-GOQDs were characterized using tip-enhanced Raman spectroscopy (TERS), photoluminescent, XPS, and UV-VIS spectroscopies. The size and morphology of N-GOQDs were studied by dynamic light scattering, AFM, SEM, and TEM. The procedure proposed allows nitrogen-doped GOQDs to be obtained, having 60–51% of carbon, 34–45% of oxygen, and up to 7.2% of nitrogen. The N-GOQD particles obtained in two hours of synthesis contain only pyrrolic defects of the graphene core. The fraction of pyridine moieties grows with the time of synthesis, while the fraction of quaternary nitrogen declines. Application of TERS allows demonstration that the N-GOQDs consist of a graphene core with an average crystallite size of 9 nm and an average distance between nearest defects smaller than 3 nm. The cytotoxicity tests reveal high viability of the monkey epithelial kidney cells Vero in the presence of N-GOQDs in a concentration below 60 mg L⁻¹. The N-GOQDs demonstrate green luminescence with an emission maximum at 505 nm and sedimentation stability in the cell culture medium.

This paper reveals the methodology for robust preparation of purified nitrogen-doped graphene oxide quantum dots with non-cytotoxic activity against monkey epithelial kidney cells (Vero ATCC® CCL-81™).     

Mutagenicity and Genotoxicity in Gill Erythrocyte Cells of Poecilia reticulata Exposed to a Glyphosate Formulation

Poecilia reticulata were exposed to herbicide Roundup Transorb^® for micronucleus test, nuclear abnormalities and comet assay. The exposure-concentrations were based on CL_50–96 h following 0, 1.41, 2.83, 4.24 and 5.65 μL L^?1 for 24 h. Micronucleus and comets were significantly increased in the gill erythrocyte cells after herbicide exposure compared with the non-exposed group. Results showed a gradual increase in the number of damaged cells, indicating a concentration-dependent effect and that this herbicide was mutagenic and genotoxic to P. reticulata and this effect could be attributed to a combination of compounds contained in the formulation with the active ingredient glyphosate.     

Transitional Care Coordination in New York City Jails: Facilitating Linkages to Care for People with HIV Returning Home from Rikers Island

New York City (NYC) jails are the epicenter of an epidemic that overwhelmingly affects Black and Hispanic men and offer a significant opportunity for public health intervention. The NYC Department of Health and Mental Hygiene instituted population based approaches to identify the HIV-infected, initiate discharge planning at jail admission, and facilitate post-release linkages to primary care. Using a caring and supportive ‘warm transitions’ approach, transitional care services are integral to continuity of care. Since 2010, over three-quarters of known HIV-infected inmates admitted to jails received discharge plans; 74 % of those released were linked to primary care. The EnhanceLink initiative’s new Health Liaison, a lynchpin role, facilitated 250 court-led placements in medical alternatives to incarceration. Transitional care coordination programs are critical to facilitate continuity of care for people with chronic health conditions including the HIV-infected returning home from jail and for the public health of the communities to which they return.     

Knowledge and behavior among health professionals in relation to cadaveric organ donation and transplantation: a questionnaire-based analysis in Portuguese hospitals

Objective

To assess knowledge and behavior relative to cadaveric organ donation and transplantation among physicians and nurses working at nine Portuguese hospitals.

Methods

This prospective study between May and October 2009 included 495 questionnaires that were returned among 840 that were delivered, a 59% response rate. The transplant questionnaire comprised three main sections: section 1, sociodemographic-professional variables of the participants with nine questions; section 2, generic questions on organ donation and transplantation with 12 questions; and section 3 evaluated knowledge with 20 specific questions on organ donation and transplantation.

Results

Sixty-one percent of the participants were females, with 40% of the overall cohort between 31 and 40 years old; 62% married; 63% working in the emergency department; and 78% nurses. Although 78% of the participants stated that they had undergone specific training on organ donation and transplantation, 62% felt that they needed more training. The reasons evoked for the low rate of donation included difficulties in initiating the process of organ donation, in diagnosing cerebral death and in obtaining necessary human resources. There were no significant differences in knowledge between physicians and nurses concerning specific organ donation and transplantation issues. Having had specific training on organ donation and transplantation was significantly associated with correct answers to several questions, including those pertaining to knowledge of the national legislation on organ donation and transplantation.

Conclusions

The present study showed a lack of specific knowledge and training on organ donation and transplantation issue. It also suggested that for hospital staff to successfully act as initiators of the organ procurement process, more information and education are necessary. This effort could significantly increase the rate of organ donation and transplantation in Portugal.