An exploration of relative health stock in advanced cancer patients.

OBJECTIVE: The authors sought to empirically test whether relative health stock, a measure of patients' sense of loss in their health due to illness, influences the treatment decisions of patients facing life-threatening conditions. Specifically, they estimated the effect of relative health stock on advanced cancer patients' decisions to participate in phase I clinical trials. METHOD: A multicenter study was conducted to survey 328 advanced cancer patients who were offered the opportunity to participate in phase I trials. The authors asked patients to estimate the probabilities of therapeutic benefits and toxicity, their relative health stock, risk preference, and the importance of quality of life. RESULTS: Controlling for health-related quality of life, an increase in relative health stock by 10 percentage points reduced the odds of choosing to participate in a phase I trial by 16% (odds ratio = 0.84, 95% confidence interval = 0.72, 0.97). CONCLUSION: Relative health stock affects advanced cancer patients' treatment decisions.     

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™).     

Small Molecule,Big Difference: The Role of Water in the Crystallization of Paclitaxel

Paclitaxel is an important antineoplastic drug, which is used widely in the treatment of many forms of cancer. The crystal structures of the anhydrous form and the hemihydrate were determined from laboratory X-ray powder diffraction data, whereas the dihydrate was solved from single-crystal synchrotron diffraction data. Intermolecular spaces allow for the inclusion of loosely bound water molecules, which are then lost easily upon heating. All three forms were found to crystallize in the orthorhombic spacegroup P2₁2₁2₁, with Z′ = 2. The unit cell parameters were found to be a = 9.6530(3) Å, b = 28.1196(8) Å, c = 33.5378(14) Å, and V = 9103.5(5) Å for the anhydrous form (363 K); a = 9.6890(2) Å, b = 28.0760(4) Å, c = 33.6166(8) Å, and V = 9144.7(3) ų for the hemihydrate (333 K); and a = 9.512(6) Å, b = 28.064(16) Å, c = 33.08(2) Å, and V = 8829.0(9) ų for the dihydrate (120 K). Water loss occurs in two steps between 120 K ≤ t ≤ 363 K. The thermal stability of the hydrates and accompanying unit cell changes were observed in situ via temperature-resolved X-ray powder diffraction and thermogravimetric analysis.     

Risk-Taking in Disorders of Natural and Drug Rewards: Neural Correlates and Effects of Probability,Valence, and Magnitude

Pathological behaviors toward drugs and food rewards have underlying commonalities. Risk-taking has a fourfold pattern varying as a function of probability and valence leading to the nonlinearity of probability weighting with overweighting of small probabilities and underweighting of large probabilities. Here we assess these influences on risk-taking in patients with pathological behaviors toward drug and food rewards and examine structural neural correlates of nonlinearity of probability weighting in healthy volunteers. In the anticipation of rewards, subjects with binge eating disorder show greater risk-taking, similar to substance-use disorders. Methamphetamine-dependent subjects had greater nonlinearity of probability weighting along with impaired subjective discrimination of probability and reward magnitude. Ex-smokers also had lower risk-taking to rewards compared with non-smokers. In the anticipation of losses, obesity without binge eating had a similar pattern to other substance-use disorders. Obese subjects with binge eating also have impaired discrimination of subjective value similar to that of the methamphetamine-dependent subjects. Nonlinearity of probability weighting was associated with lower gray matter volume in dorsolateral and ventromedial prefrontal cortex and orbitofrontal cortex in healthy volunteers. Our findings support a distinct subtype of binge eating disorder in obesity with similarities in risk-taking in the reward domain to substance use disorders. The results dovetail with the current approach of defining mechanistically based dimensional approaches rather than categorical approaches to psychiatric disorders. The relationship to risk probability and valence may underlie the propensity toward pathological behaviors toward different types of rewards.     

Flexural strength,biocompatibility, and antimicrobial activity of a polymethyl methacrylate denture resin enhanced with graphene and silver nanoparticles

Clinical Oral Investigations - The study evaluates the effect of adding graphene-Ag nanoparticles (G-AgNp) to a PMMA auto-polymerizing resin, with focus on antibacterial activity, cytotoxicity,...     

Primary versus post-treatment apical periodontitis: microbial composition,lipopolysaccharides and lipoteichoic acid levels,signs and symptoms

Clinical Oral Investigations - To compare the microbial load and composition and to determine the lipopolysaccharides (LPS) and lipoteichoic acid (LTA) concentrations found in primary apical...