Time-independent,high electron mobility in thin PC61BM films: Relevance to organic photovoltaics

Ultrafast optical probing of electric field by means of electroabsorption combined with conventional photocurrent measurements was employed to investigate the drift and mobility dynamics of photo-generated charge carriers in the pristine PC₆₁BM film and in the blend with a merocyanine dye. Electrons passed a 40 nm thick PC₆₁BM film within a few picoseconds with time-independent and weakly dispersive mobility. The electron mobility is 1 cm²/(V s) at 1 MV/cm and an estimate of the zero-field mobility yields 5 ⋅ 10⁻² cm²/(V s). The initial electron mobility in the blend is of the order of 10⁻² cm²/(V s) and decreases rapidly. We conclude that electron motion in PC₆₁BM based organic bulk hetero-junction solar cells is limited by barriers between PC₆₁BM domains rather than by intrinsic PC₆₁BM properties.     

Immune Aging and Immunotherapy in Cancer

Immune functions decline as we age, while the incidence of cancer rises. The advent of immune checkpoint blockade (ICB) has not only revolutionized cancer therapy, but also spawned great interest in identifying predictive biomarkers, since only one third of patients show treatment response. The aging process extensively affects the adaptive immune system and thus T cells, which are the main target of ICB. In this review, we address age-related changes regarding the adaptive immune system with a focus on T cells and their implication on carcinogenesis and ICB. Differences between senescence, exhaustion, and anergy are defined and current knowledge, treatment strategies, and studies exploring T cell aging as a biomarker for ICB are discussed. Finally, novel approaches to improve immunotherapies and to identify biomarkers of response to ICB are presented and their potential is assessed in a comparative analysis.     

THE POISSON WAVELET TRANSFORM

This paper introduces a family of wavelet transforms based on the Poisson Transform. The wavelet transform maps L² (R)functions to a space described by two continuous variables, scale and translation, as well as a discrete index. Reconstruction in the wavelet domain can be done for each of the discrete indices. Additionally, a different reconstruction formula exists for the Poisson Transform domain. We develop the Poisson Wavelet Transform, present an example relevant to stable, over-damped, linear, time-invariant systems, and show the relationship between the Poisson Transform and the Poisson Wavelet Transform.     

Nicotine, cotinine, withdrawal, and craving patterns during smoking and nicotine nasal spray use: results from a pilot study with African American men.

Nicotine intake via smoking is highly variable. Individualized dosing of nicotine replacement therapy (NRT) may improve product efficacy, but a better understanding of the within-day and within-subject relationships between smoking, NRT use, nicotine and cotinine concentrations in blood, and cravings and withdrawal symptoms is needed to inform dosing algorithms. A pilot study was undertaken to collect data on these relationships and to assess the feasibility of the methods needed for this type of research, including a sophisticated statistical modeling technique (a two-part mixed-effects model with correlated random effects that accounts for clumping at zero). Because nicotine metabolism varies by gender and race, the sample was homogeneous with respect to these characteristics. In a within-subjects study, 27 African American adult male smokers carried a computerized cigarette dispenser for 1 week, capturing the time each cigarette was smoked. Subjects then entered an inpatient setting for 1 day of scheduled smoking (matched to data from the cigarette dispenser to create an ecologically valid schedule) and 4 days of ad libitum nicotine nasal spray use, while tobacco abstinent. Eight times per day, at 2-hour intervals, blood was drawn and ratings of cigarette cravings and withdrawal symptoms were obtained. On average, subjects used less than half of the manufacturer's recommended minimum daily dose of nicotine nasal spray. Large differences in nicotine and cotinine levels were observed between individuals. When predicting nicotine, cotinine, withdrawal, and cravings, we observed significant interactions between route of nicotine intake and a variety of independent variables.     

Effects of ginseng treatment on neutrophil chemiluminescence and immunoglobulin G subclasses in a rat model of chronic Pseudomonas aeruginosa pneumonia

OBJECTIVE: To examine the effect of different concentrations of calcium on the contractile responses of isolated strips of rabbit bladder detrusor to various forms of stimulation after 2 h incubation in the presence of substrate and oxygen depletion (in vitro ischaemia), followed by 1 h of recovery. The resultant contractile responses were correlated with the level of lipid peroxidation as determined by malonedialdehyde (MDA) concentration. MATERIALS AND METHODS: Isolated strips of rabbit bladder detrusor smooth muscle were incubated in Tyrode's solution containing different concentrations of calcium (0-5.4 mmol/L). The effect of 2 h of incubation in oxygen- and substrate-free medium (in vitro ischaemia), followed by a 1-h incubation in the presence of oxygen and substrate, on the contractile responses to field stimulation, carbachol and KCl were determined. The effects of repetitive stimulation (15 s of stimulation at 32 Hz applied every 5 min during the 2-h experimental period) were also assessed. RESULTS: The contractile responses to all stimuli increased as the extracellular calcium concentration was increased from 0.6 to 5.4 mmol/L. A 2 h exposure to in vitro ischaemia, followed by a return to normal solution, resulted in a diminished response to all stimuli. This contractile dysfunction was least in the presence of calcium chelator (EGTA) and greatest in the presence of 5.4 mmol/L calcium. Repetitive stimulation during in vitro ischaemia also exacerbated the contractile dysfunction. Lipid peroxidation increased during in vitro ischaemia in proportion to the calcium concentration and was enhanced by repetitive stimulation during this period. Regardless of the incubation conditions, the reduction in the contractile response was significantly greater for field-stimulated tissues than for those stimulated with carbachol or KCl. CONCLUSIONS: These results show that the magnitude of contractile dysfunction induced by incubation in the presence of substrate and oxygen depletion is reduced in the presence of low calcium concentrations, increased in the presence of high calcium levels and increased in the presence of repetitive stimulation. In addition, the level of lipid peroxidation after the recovery period was proportional to the magnitude of contractile dysfunction present.     

Comparison of laser-wavelength operation for drilling of via holes in AlGaN/GaN HEMTs on SiC substrates

By using a frequency-tripled Nd:YVO₄ laser source (355 nm) for drilling through-wafer via holes in SiC substrates, we can reduce the surface contamination and achieve better smoothness inside the via holes compared to use of the more common 1064-nm Nd:YVO₄ laser. The sheet and contact resistance of AlGaN/GaN HEMT layers grown on SiC substrates were similar after formation of vias by 355-nm laser drilling to those of the undrilled reference sample. By sharp contrast, 1064-nm laser drilling produces significant redeposition of ablated material around the via and degrades the electrical properties of the HEMT layers.     

The Impact of the Sibling in Clinical Practice: Transference and Countertransference Dynamics.

For many years, the impact of sibling relationships on psychological development has been neglected in the literature, overshadowed by the role of the parent-child relationship. As a result, attention to sibling dynamics and sibling transference as valuable information for case formulation and treatment interventions has not been used to its maximum potential. The authors demonstrate how deliberate consideration of sibling dynamics as well as the transferences and countertransferences associated with those dynamics can facilitate treatment. Several important sibling dynamics are discussed, including siblings' influences on identity development; sibling rivalry, jealousy, envy, guilt, and resentment; and sibling attachment. The impact of sibling dynamics on adult love relationships is discussed, as are potential effects of sibling abuse and sibling bereavement. Examples of how these dynamics can manifest themselves in transference and countertransference reactions and suggestions for working with those dynamics are illustrated with clinical examples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)