Dye Solar Cells: Basic and Photon Management Strategies

Since the introduction and development of the dye-sensitized solar cell (DSC) several efforts have been made to optimize the materials involved in the photo-electrochemical process and to improve the light conversion efficiency of the device , by exploiting a low cost production process based on simple fabrication methods, similar to those used in printing processes

Rapid Assessment of Susceptibility of Bacteria and Erythrocytes to Antimicrobial Peptides by Single-Cell Impedance Cytometry

Antimicrobial peptides (AMPs) represent a promising classof compoundsto fight antibiotic-resistant infections. In most cases, they killbacteria by making their membrane permeable and therefore exhibitlow propensity to induce bacterial resistance. In addition, they areoften selective, killing bacteria at concentrations lower than thoseat which they are toxic to the host. However, clinical applicationsof AMPs are hindered by a limited understanding of their interactionswith bacteria and human cells. Standard susceptibility testing methodsare based on the analysis of the growth of a bacterial populationand therefore require several hours. Moreover, different assays arerequired to assess the toxicity to host cells. In this work, we proposethe use of microfluidic impedance cytometry to explore the actionof AMPs on both bacteria and host cells in a rapid manner and withsingle-cell resolution. Impedance measurements are particularly well-suitedto detect the effects of AMPs on bacteria, due to the fact that themechanism of action involves perturbation of the permeability of cellmembranes. We show that the electrical signatures of Bacillus megaterium cells and human red blood cells(RBCs) reflect the action of a representative antimicrobial peptide,DNS-PMAP23. In particular, the impedance phase at high frequency (e.g.,11 or 20 MHz) is a reliable label-free metric for monitoring DNS-PMAP23bactericidal activity and toxicity to RBCs. The impedance-based characterizationis validated by comparison with standard antibacterial activity assaysand absorbance-based hemolytic activity assays. Furthermore, we demonstratethe applicability of the technique to a mixed sample of B. megaterium cells and RBCs, which paves the wayto study AMP selectivity for bacterial versus eukaryotic cells inthe presence of both cell types

Plasma Dynamics

Contains table of contents for Section 2 and reports on three research projects.U.S. Navy - Office of Naval Research Grant N00014-90-J-4130Princeton University/Tokamak Physics Experiment Grant S-03688-GU.S. Department of Energy Grant DE-FG02-91-ER-54109National Science Foundation Grant ATM 94-2428

Toward a theranostic device for gliomas

Background: In the surgical management of glioblastoma, a highly aggressive and incurable type of brain cancer, identification and treatment of residual tissue is the most common site of disease recurrence. Monitoring and localized treatment are achieved with engineered microbubbles (MBs) by combining ultrasound and fluorescence imaging with actively targeted temozolomide (TMZ) delivery. Methods: The MBs were conjugated with a near-infrared fluorescence probe CF790, cyclic pentapeptide bearing the RGD sequence and a carboxyl-temozolomide, TMZA. The efficiency of adhesion to HUVEC cells was assessed in vitro in realistic physiological conditions of shear rate and vascular dimensions. Cytotoxicity of TMZA-loaded MBs on U87 MG cells and IC50 were assessed by MTT tests. Results: We report on the design of injectable poly(vinyl alcohol) echogenic MBs designed as a platform with active targeting ability to tumor tissues, by tethering on the surface a ligand having the tripeptide sequence, RGD. The biorecognition of RGD-MBs onto HUVEC cells is quantitatively proved. Efficient NIR emission from the CF790-decorated MBs was successfully detected. The conjugation on the MBs surface of a specific drug as TMZ is achieved. The pharmacological activity of the coupled-to-surface drug is preserved by controlling the reaction conditions. Conclusions: We present an improved formulation of PVA-MBs to achieve a multifunctional device with adhesion ability, cytotoxicity on glioblastoma cells and supporting imaging

The brain functional networks associated to human and animal suffering differ among omnivores, vegetarians and vegans.

Empathy and affective appraisals for conspecifics are among the hallmarks of social interaction. Using functional MRI, we hypothesized that vegetarians and vegans, who made their feeding choice for ethical reasons, might show brain responses to conditions of suffering involving humans or animals different from omnivores. We recruited 20 omnivore subjects, 19 vegetarians, and 21 vegans. The groups were matched for sex and age. Brain activation was investigated using fMRI and an event-related design during observation of negative affective pictures of human beings and animals (showing mutilations, murdered people, human/animal threat, tortures, wounds, etc.). Participants saw negative-valence scenes related to humans and animals, alternating with natural landscapes. During human negative valence scenes, compared with omnivores, vegetarians and vegans had an increased recruitment of the anterior cingulate cortex (ACC) and inferior frontal gyrus (IFG). More critically, during animal negative valence scenes, they had decreased amygdala activation and increased activation of the lingual gyri, the left cuneus, the posterior cingulate cortex and several areas mainly located in the frontal lobes, including the ACC, the IFG and the middle frontal gyrus. Nonetheless, also substantial differences between vegetarians and vegans have been found responding to negative scenes. Vegetarians showed a selective recruitment of the right inferior parietal lobule during human negative scenes, and a prevailing activation of the ACC during animal negative scenes. Conversely, during animal negative scenes an increased activation of the inferior prefrontal cortex was observed in vegans. These results suggest that empathy toward non conspecifics has different neural representation among individuals with different feeding habits, perhaps reflecting different motivational factors and beliefs

Novel application of custom-made stent-grafts with inner branches for secondary treatment after stent-graft migration of previous infrarenal endovascular aortic repair

Purpose: We present a novel application of custom-made stent grafts (CMSGs) with inner branches to incorporate target vessels (TVs) as an alternative to fenestrations or directional branches for secondary treatment after stent graft migration of previous infrarenal endovascular aortic repair (EVAR). Case report: Two consecutive patients with stent graft migration of previous EVAR were electively treated at our institution from January 1, 2018 through December 31, 2018. Stent graft migration was defined as radiologic evidence of stent graft displacement >10 mm. In both cases, a proximal type I endoleak was noted, and the residual infrarenal aorta above the previous endograft was unsuitable as the proximal landing zone for a nonfenestrated cuff. Repair was planned by means of a CMSG with 4 inner branches. The procedures were conducted in two-stage fashion to minimize the risk of spinal cord ischemia. The procedures were technically successful with a total of 8 TVs stented. Both patients did not suffer from any early (i.e., up to 30 days) major adverse events, and no access-site complications were noted. At one-year follow-up, computed tomography angiography showed regular placement of the CMSGs, widely patent TVs, absence of any type I or III endoleak, and stable sac size. No late reinterventions were recorded. Conclusions: Secondary treatment of stent graft migration after previous EVAR is safe and feasible using CSMGs with 4 inner branches. This technique is effective as showed by stable sac size and 100% freedom from TVI at mid-term imaging follow-up. Larger cohorts and longer follow-up are needed to confirm the preliminary results

Graph showing error bars of means and standard deviations of empathy quotient (EQ) score in the three groups of subjects.

<p>See text for further details.</p

Cluster maxima coordinates of activations/deactivations, at the within-group one sample t test analysis of the areas which showed a significant interaction between groups and conditions (p<0.001, uncorrected).

<p>MNI = Montreal Neurological Institute, R = right, L = left, IFG = inferior frontal gyrus, ACC = anterior cingulate cortex.</p><p>Note that none of the regions shown in the table was significantly deactivated (one-sample t test).</p