Production of ready-to-use few-layer graphene in aqueous suspensions.

Graphene has promising physical and chemical properties such as high strength and flexibility, coupled with high electrical and thermal conductivities. It is therefore being incorporated into polymer-based composites for use in electronics and photonics applications. A main constraint related to the graphene development is that, being of a strongly hydrophobic nature, almost all dispersions (usually required for its handling and processing toward the desired application) are prepared in poisonous organic solvents such as N-methyl pyrrolidone or N,N-dimethyl formamide.

Few-Layer Graphene Kills Selectively Tumor Cells from Myelomonocytic Leukemia Patients.

In the cure of cancer, a major cause of today's mortality, chemotherapy is the most common treatment, though serious frequent challenges are encountered by current anticancer drugs. We discovered that few-layer graphene (FLG) dispersions have a specific killer action on monocytes, showing neither toxic nor activation effects on other immune cells. We confirmed the therapeutic application of graphene on an aggressive type of cancer that is myelomonocytic leukemia, where the monocytes are in their malignant form.

Differential cytotoxic effects of graphene and graphene oxide on skin keratinocytes.

Impressive properties make graphene-based materials (GBMs) promising tools for nanoelectronics and biomedicine. However, safety concerns need to be cleared before mass production of GBMs starts. As skin, together with lungs, displays the highest exposure to GBMs, it is of fundamental importance to understand what happens when GBMs get in contact with skin cells.

Surface Area of Carbon Nanoparticles: A Dose Metric for a More Realistic Ecotoxicological Assessment.

Engineered nanoparticles such as graphenes, nanodiamonds, and carbon nanotubes correspond to different allotropes of carbon and are among the best candidates for applications in fast-growing nanotechnology. It is thus likely that they may get into the environment at each step of their life cycle: production, use, and disposal. The aquatic compartment concentrates pollutants and is expected to be especially impacted.

Graphene Oxide Nanosheets Reshape Synaptic Function in Cultured Brain Networks.

Graphene offers promising advantages for biomedical applications. However, adoption of graphene technology in biomedicine also poses important challenges in terms of understanding cell responses, cellular uptake, or the intracellular fate of soluble graphene derivatives. In the biological microenvironment, graphene nanosheets might interact with exposed cellular and subcellular structures, resulting in unexpected regulation of sophisticated biological signaling.

Graphene-Based Interfaces Do Not Alter Target Nerve Cells.

Neural-interfaces rely on the ability of electrodes to transduce stimuli into electrical patterns delivered to the brain. In addition to sensitivity to the stimuli, stability in the operating conditions and efficient charge transfer to neurons, the electrodes should not alter the physiological properties of the target tissue. Graphene is emerging as a promising material for neuro-interfacing applications, given its outstanding physico-chemical properties.

Graphene-based electroresponsive scaffolds as polymeric implants for on-demand drug delivery.

Stimuli-responsive biomaterials have attracted significant attention in the field of polymeric implants designed as active scaffolds for on-demand drug delivery. Conventional porous scaffolds suffer from drawbacks such as molecular diffusion and material degradation, allowing in most cases only a zero-order drug release profile. The possibility of using external stimulation to trigger drug release is particularly enticing.

Exfoliation of graphite with triazine derivatives under ball-milling conditions: preparation of few-layer graphene via selective noncovalent interactions.

A ball-milling treatment can be employed to exfoliate graphite through interactions with commercially available melamine under solid conditions. This procedure allows the fast production of relatively large quantities of material with a low presence of defects. The milling treatment can be modulated in order to achieve graphene flakes with different sizes.

Few-layer graphenes from ball-milling of graphite with melamine.

We report a simple, practical scalable procedure to produce few-layer graphene sheets using ball-milling. Commercially available melamine can be efficiently used to exfoliate graphite and generate concentrated water or DMF dispersions.

Integrated food chain surveillance system for Salmonella spp. in Mexico.

Few developing countries have foodborne pathogen surveillance systems, and none of these integrates data from humans, food, and animals. We describe the implementation of a 4-state, integrated food chain surveillance system (IFCS) for Salmonella spp. in Mexico.

Rapid and widespread dissemination of multidrug-resistant blaCMY-2 Salmonella Typhimurium in Mexico.

Objectives: We describe the emergence and dissemination of multidrug-resistant (MDR) Salmonella Typhimurium in humans, retail meat and food animals from Yucatan, Mexico.

Methods: Salmonella Typhimurium isolates were collected through an active surveillance system and tested for susceptibility to 12 antimicrobial agents. Isolates that were non-susceptible to ceftriaxone were tested with 10 additional antimicrobials and assayed by PCR for the presence of CMY, CTX-M, SHV, TEM and OXA beta-lactamase genes.

[Pregnancy, delivery and puerperium: beliefs and practices of midwives in San Luis Potosi, Mexico].

Objective: To document the beliefs and practices of traditional midwifes in regard to pregnancy, delivery and puerperium.

Method: Taking advantage of a training course for 160 local traditional midwives from the Media and Huasteca regions of San Luis Potosí State, Mexico. Two of the teacher-nurses interviewed 25 of them, supported by a member of Náhuatl and Tenek communities.

Nontyphoidal Salmonella from human clinical cases, asymptomatic children, and raw retail meats in Yucatan, Mexico.

Background: We report the results of a 3-year Salmonella surveillance study of persons with diarrhea; asymptomatic children; and retail pork, poultry, and beef in Yucatan, Mexico.

Methods: Isolates were characterized according to serotype, antimicrobial susceptibility, and genetic relatedness with pulsed-field gel electrophoresis.

Results: Salmonella Typhimurium was the most common serotype found in ill humans (21.