Atmospheric Ice‐Nucleating Particles in the Dusty Tropical Atlantic

Desert dust is one of the most important atmospheric ice-nucleating aerosol species around the globe. However, there have been very few measurements of ice-nucleating particle (INP) concentrations in dusty air close to desert sources. In this study we report the concentration of INPs in dust laden air over the tropical Atlantic within a few days' transport of one of the world's most important atmospheric sources of desert dust, the Sahara. These measurements were performed as part of the Ice in Clouds Experiment-Dust campaign based in Cape Verde, during August 2015. INP concentrations active in the immersion mode, determined using a droplet-on-filter technique, ranged from around 10² m⁻³ at -12°C to around 10⁵ m⁻³ at -23°C. There is about 2 orders of magnitude variability in INP concentration for a particular temperature, which is determined largely by the variability in atmospheric dust loading. These measurements were made at altitudes from 30 to 3,500 m in air containing a range of dust loadings. The ice active site density (n s ) for desert dust dominated aerosol derived from our measurements agrees with several laboratory-based parameterizations for ice nucleation by desert dust within 1 to 2 orders of magnitude. The small variability in n s values determined from our measurements (within about 1 order of magnitude) is striking given that the back trajectory analysis suggests that the sources of dust were geographically diverse. This is consistent with previous work, which indicates that desert dust's ice-nucleating activity is only weakly dependent on source

Direct Injection of Functional Single-Domain Antibodies from E. coli into Human Cells

Intracellular proteins have a great potential as targets for therapeutic antibodies (Abs) but the plasma membrane prevents access to these antigens. Ab fragments and IgGs are selected and engineered in E. coli and this microorganism may be also an ideal vector for their intracellular delivery. In this work we demonstrate that single-domain Ab (sdAbs) can be engineered to be injected into human cells by E. coli bacteria carrying molecular syringes assembled by a type III protein secretion system (T3SS). The injected sdAbs accumulate in the cytoplasm of HeLa cells at levels ca. 105–106 molecules per cell and their functionality is shown by the isolation of sdAb-antigen complexes. Injection of sdAbs does not require bacterial invasion or the transfer of genetic material. These results are proof-of-principle for the capacity of E. coli bacteria to directly deliver intracellular sdAbs (intrabodies) into human cells for analytical and therapeutic purposes

‘Squeezing’ near-field thermal emission for ultra-efficient high-power thermophotovoltaic conversion

We numerically demonstrate near-field planar ThermoPhotoVoltaic systems with very high efficiency and output power, at large vacuum gaps. Example performances include: at 1200 °K emitter temperature, output power density 2 W/cm[superscript 2] with ~47% efficiency at 300 nm vacuum gap; at 2100 °K, 24 W/cm[superscript 2] with ~57% efficiency at 200 nm gap; and, at 3000 °K, 115 W/cm[superscript 2] with ~61% efficiency at 140 nm gap. Key to this striking performance is a novel photonic design forcing the emitter and cell single modes to cros resonantly couple and impedance-match just above the semiconductor bandgap, creating there a ‘squeezed’ narrowband near-field emission spectrum. Specifically, we employ surface-plasmon-polariton thermal emitters and silver-backed semiconductor-thin-film photovoltaic cells. The emitter planar plasmonic nature allows for high-power and stable high-temperature operation. Our simulations include modeling of free-carrier absorption in both cell electrodes and temperature dependence of the emitter properties. At high temperatures, the efficiency enhancement via resonant mode cross-coupling and matching can be extended to even higher power, by appropriately patterning the silver back electrode to enforce also an absorber effective surface-plasmon-polariton mode. Our proposed designs can therefore lead the way for mass-producible and low-cost ThermoPhotoVoltaic micro-generators and solar cells.Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (Contract W911NF-13-D-0001

Supportive care in early rehabilitation for advanced-stage radiated head and neck cancer patients

Item does not contain fulltextObjective To investigate the health-related quality of life (HRQoL) and supportive follow-up care needs 1 month posttreatment for patients with advanced-stage (stage III or IV) radiated head and neck cancer (HNC) who were treated with curative intent. Study Design An exploratory, descriptive analysis of HRQoL data obtained from 3 treatment groups: conventional radiotherapy (RT, n = 21), surgery + radiotherapy (SRT, n = 10), and chemoradiation (CRT, n = 21). Setting The head and neck oncology center of a university hospital. Subjects and Methods Fifty-two patients completed the EORTC QLQ-C30 and EORTC QLQ H&N35 self-report questionnaires 1 month posttreatment. Descriptive statistics and clinically relevant differences between the groups were analyzed. Results The HRQoL outcomes between groups differed. Clinically relevant difference was observed in the RT and CRT groups with respect to dry mouth, coughing, feeling ill, use of painkillers, and the use of nutritional supplements. The RT group differed from the other groups with respect to pain and swallowing. The CRT group differed from the other groups regarding role functioning. Conclusion Health-related quality of life differs between RT, SRT, and CRT patients 1 month posttreatment. The RT- and CRT-treated patients reported higher impairment than the patients who were treated with SRT. Nutritional intake and oral function emphasize the importance of providing supportive care to radiated advanced-stage HNC patients throughout the treatment trajectory and the need for continuation during the first few posttreatment months