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Background Histone 3 lysine27-to-methionine mutations (H3-K27M) frequently occur in childhood diffuse midline gliomas (DMGs) of the pons, thalamus and spinal cord, presumed to be driven by the specific spatiotemporal context of these midline locations during postnatal development. While most common in the pons and at mid-childhood ages, the same oncohistone mutation is recurrently detected in adult DMGs and throughout different midline regions. The potential heterogeneity of tumors at different ages and in different anatomical locations of the midline are vastly understudied. Material and Methods Through dissecting the transcriptomic, epigenomic and spatial architectures of a comprehensive cohort of patient H3-K27M DMGs - spanning the age range from 2-68 years and locations from spinal cord to thalamus - at single cell resolution, we delineate how age- and location-dependent contexts shape glioma cell-intrinsic and -extrinsic features in light of the shared driver mutation. Results We identify that oligodendrocyte precursor (OPC)-like cells constitute the stem-like compartment in H3-K27M DMGs across all clinico-anatomical groups, however, depending on location, display varying levels of maturity resembling less differentiated pre-OPCs or more mature OPCs further differentiated along the oligodendroglial lineage. We further demonstrate increased mesenchymal cell states in adult tumors, which we link to age-related differences in glioma-associated immune cell compartments. We for the first time resolve the spatial organization of H3-K27M DMG cell types in intact patient tissues, identifying a local niche of the oligodendroglial lineage. Conclusion Our study provides a powerful resource for rational modeling and therapeutic frameworks taking into account determinants of age and location in this lethal glioma group.

We investigate the role of global value chains in the declines of manufacturing employment and output in the U.S. during COVID-19. Specifically, we identify the role of global value chains by exploiting heterogeneity across industries in cross-country sourcing patterns and its interaction with exogenous cross-country variation in the containment policies introduced to combat the virus. We find that global value chains played a significant role in the decline of output and employment across U.S. manufactures. Moreover, we find a modest impact of diversifying or renationalizing global value chains in mitigating the economy's exposure to foreign shocks.

The engineering of broadband absorbers to harvest white light in thin-film semiconductors is a major challenge in developing renewable materials for energy harvesting. Many solution-processed materials with high manufacturability and low cost, such as semiconductor quantum dots, require the use of film structures with thicknesses on the order of 1 μm to absorb incoming photons completely. The electron transport lengths in these media, however, are 1 order of magnitude smaller than this length, hampering further progress with this platform. Herein, we show that, by engineering suitably disordered nanoplasmonic structures, we have created a new class of dispersionless epsilon-near-zero composite materials that efficiently harness white light. Our nanostructures localize light in the dielectric region outside the epsilon-near-zero material with characteristic lengths of 10-100 nm, resulting in an efficient system for harvesting broadband light when a thin absorptive film is deposited on top of the structure. By using a combination of theory and experiments, we demonstrate that ultrathin layers down to 50 nm of colloidal quantum dots deposited atop the epsilon-near-zero material show an increase in broadband absorption ranging from 200% to 500% compared to a planar structure of the same colloidal quantum-dot-absorber average thickness. When the epsilon-near-zero nanostructures were used in an energy-harvesting module, we observed a spectrally averaged 170% broadband increase in the external quantum efficiency of the device, measured at wavelengths between 400 and 1200 nm. Atomic force microscopy and photoluminescence excitation measurements demonstrate that the properties of these epsilon-near-zero structures apply to general metals and could be used to enhance the near-field absorption of semiconductor structures more widely. We have developed an inexpensive electrochemical deposition process that enables scaled-up production of this nanomaterial for large-scale energy-harvesting applications.

Solubility-enhancing amorphous solid dispersions are used in the oral delivery of hydrophobic, crystallizable drugs. Effective solid dispersion excipients enable high supersaturation drug concentrations and limit crystallization of the dissolved drug over extended times. We prepared poly(N-isopropylacrylamide)-based excipients of varying molar mass and with various end group identities, and examined their ability to improve the aqueous solubility of the Biopharmaceutical Class System Class II drug, phenytoin. Solid dispersions of these excipients and phenytoin were prepared at 10 wt % drug loading. Performance depended largely on the tendency of the polymer excipient to form micellar aggregates in aqueous buffer. We present several systems that achieved significant improvement of phenytoin solubility, with no indication of drug crystallization over 6 h. This is among the highest enhancement factors seen for phenytoin to date, and the success of these systems is ascribed to the added stability of these “se...

Colloidal quantum dots (CQD) are an attractive thin-film material for photovoltaic applications due to low material costs, ease of fabrication, and size-tunable band gap. Unfortunately, today they suffer from a compromise between light absorption and photocarrier extraction, a fact that currently prevents the complete harvest of incoming above-band-gap solar photons. We have investigated the use of structured substrates and/or electrodes to increase the effective light path through the active material and found that these designs require highly conformal application of the light-absorbing films to achieve the greatest enhancement. This conformality requirement derives from the need for maximal absorption enhancement combined with shortest-distance charge transport. Here we report on a means of processing highly conformal layer-by-layer deposited CQD absorber films onto microstructured, light-recycling electrodes. Specifically, we engineer surface hydrophilicity to achieve conformal deposition of upper layers atop underlying ones. We show that only with the application of conformal coating can we achieve optimal quantum efficiency and enhanced power conversion efficiency in structured-electrode CQD cells.

The performance of photodetectors is judged via high responsivity, fast speed of response, and low background current. Many previously reported photodetectors based on size-tuned colloidal quantum dots (CQDs) have relied either on photodiodes, which, since they are primary photocarrier devices, lack gain; or photoconductors, which provide gain but at the expense of slow response (due to delayed charge carrier escape from sensitizing centers) and an inherent dark current vs responsivity trade-off. Here we report a photojunction field-effect transistor (photoJFET), which provides gain while breaking prior photoconductors' response/speed/dark current trade-off. This is achieved by ensuring that, in the dark, the channel is fully depleted due to a rectifying junction between a deep-work-function transparent conductive top contact (MoO3) and a moderately n-type CQD film (iodine treated PbS CQDs). We characterize the rectifying behavior of the junction and the linearity of the channel characteristics under illumination, and we observe a 10 μs rise time, a record for a gain-providing, low-dark-current CQD photodetector. We prove, using an analytical model validated using experimental measurements, that for a given response time the device provides a two-orders-of-magnitude improvement in photocurrent-to-dark-current ratio compared to photoconductors. The photoJFET, which relies on a junction gate-effect, enriches the growing family of CQD photosensitive transistors.

Extremely thin-absorber solar cells offer low materials utilization and simplified manufacture but require improved means to enhance photon absorption in the active layer. Here, we report enhanced-absorption colloidal quantum dot (CQD) solar cells that feature transfer-stamped solution-processed pyramid-shaped electrodes employed in a hierarchically structured device. The pyramids increase, by up to a factor of 2, the external quantum efficiency of the device at absorption-limited wavelengths near the absorber band edge. We show that absorption enhancement can be optimized with increased pyramid angle with an appreciable net improvement in power conversion efficiency, that is, with the gain in current associated with improved absorption and extraction overcoming the smaller fractional decrease in open-circuit voltage associated with increased junction area. We show that the hierarchical combination of micron-scale structured electrodes with nanoscale films provides for an optimized enhancement at absorption-limited wavelengths. We fabricate 54.7° pyramid-patterned electrodes, conformally apply the quantum dot films, and report pyramid CQD solar cells that exhibit a 24% improvement in overall short-circuit current density with champion devices providing a power conversion efficiency of 9.2%.

Interface recombination was studied in colloidal quantum dot photovoltaics. Optimization of the TiO2-PbS interface culminated in the introduction of a thin ZnO buffer layer deposited with atomic layer deposition. Transient photovoltage measurements indicated a nearly two-fold decrease in the recombination rate around 1 sun operating conditions. Improvement to the recombination rate led to a device architecture with superior open circuit voltage (VOC) and photocurrent extraction. Overall a 10% improvement in device efficiency was achieved with Voc enhancements up to 50 mV being realized.

Recent advances in spectrally tuned, solution-processed plasmonic nanoparticles have provided unprecedented control over light's propagation and absorption via engineering at the nanoscale. Simultaneous parallel progress in colloidal quantum dot photovoltaics offers the potential for low-cost, large-area solar power; however, these devices suffer from poor quantum efficiency in the more weakly absorbed infrared portion of the sun's spectrum. Here, we report a plasmonic-excitonic solar cell that combines two classes of solution-processed infrared materials that we tune jointly. We show through experiment and theory that a plasmonic-excitonic design using gold nanoshells with optimized single particle scattering-to-absorption cross-section ratios leads to a strong enhancement in near-field absorption and a resultant 35% enhancement in photocurrent in the performance-limiting near-infrared spectral region.

Deuterium retention during 10 eV and 500 eV/D + irradiations at 300 and 500 K was compared for 99.96% pure polycrystalline tungsten (PCW) foils and similar PCW foils contaminated with carbon and oxygen impurities. The contaminated foils showed reduced deuterium retention at 500 K compared with pure foil specimens while there was no difference for 300 K irradiations. X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS) of the unirradiated specimens showed regions of highly localised, non-homogeneous C and O contamination as well as a broader region of low level contamination of about 1–10% areal coverage. It is hypothesised that the C/O contamination creates a diffusion barrier in the PCW foil preventing deuterium from diffusing from the near surface into the bulk, thus reducing overall D retention at 500 K. This finding has implications for tritium retention in ITER; if carbon contamination even at low levels can impede T diffusion into the bulk it would mean reduced T loading in W plasma-facing components.

The size-effect tunability of colloidal quantum dots enables facile engineering of the bandgap at the time of nanoparticle synthesis. The dependence of effective bandgap on nanoparticle size also presents a challenge if the size dispersion, hence bandgap variability, is not well-controlled within a given quantum dot solid. The impact of this polydispersity is well-studied in luminescent devices as well as in unipolar electronic transport; however, the requirements on monodispersity have yet to be quantified in photovoltaics. Here we carry out a series of combined experimental and model-based studies aimed at clarifying, and quantifying, the importance of quantum dot monodispersity in photovoltaics. We successfully predict, using a simple model, the dependence of both open-circuit voltage and photoluminescence behavior on the density of small-bandgap (large-diameter) quantum dot inclusions. The model requires inclusion of trap states to explain the experimental data quantitatively. We then explore using this same experimentally tested model the implications of a broadened quantum dot population on device performance. We report that present-day colloidal quantum dot photovoltaic devices with typical inhomogeneous linewidths of 100-150 meV are dominated by surface traps, and it is for this reason that they see marginal benefit from reduction in polydispersity. Upon eliminating surface traps, achieving inhomogeneous broadening of 50 meV or less will lead to device performance that sees very little deleterious impact from polydispersity.

The aim of this study is to describe the initial antibiotic treatment regimens, severity of illness, and in-hospital mortality among culture-negative (CN) and culture-positive (CP) patients with health-care-associated pneumonia (HCAP).We used a retrospective cohort study, examining adult patients with HCAP from Barnes-Jewish Hospital, a 1,200-bed urban teaching hospital.Eight hundred seventy patients with HCAP were identified over a 3-year period (January 2003 through December 2005) of whom 431 (49.5%) were CP. Among the non-CP patients, 290 (66.1%) had no respiratory cultures obtained, and 149 (33.9%) had no growth or nonpathogenic oral flora identified and were classified as CN. CN patients were more likely to have received an initial antibiotic regimen (ceftriaxone +/- azithromycin or moxifloxacin) targeting community-acquired pneumonia pathogens compared with CP patients (71.8% vs 25.5%, P.001). Severity of illness as assessed by ICU admission and mechanical ventilation (MV) was statistically lower in CN compared with CP patients (ICU admittance 12.1% vs 48.7%, P.001; MV: 6.7% vs 44.5%, P.001). In-hospital mortality and hospital length of stay were also statistically lower for CN patients (mortality: 7.4% vs 24.6%, P.001; hospital length of stay: 6.7 +/- 7.4 days vs 12.1 +/- 11.7 days, P.001).In this analysis, patients with CN HCAP had lower severity of illness, hospital mortality, and hospital length of stay compared with CP patients. These data suggest that patients with CN HCAP differ substantially from patients with HCAP with positive microbiologic cultures.

OBJECTIVE: To examine the relationship between treatment-related variables for Candida bloodstream infection and hospital mortality. DESIGN: Retrospective cohort analysis. SETTING: Thousand two hundred-bed academic medical center. PATIENTS: A total of 245 consecutive patients with Candida bloodstream infections who received antifungal therapy. INTERVENTIONS: Identification of treatment-related risk factors: central vein catheter retention, inadequate initial fluconazole dosing, and delayed administration of antifungal therapy. MEASUREMENTS AND MAIN RESULTS: A total of 245 patients with Candida bloodstream infections who received antifungal therapy were identified. One hundred eleven (45.3%) patients were managed in an intensive care unit and analyzed as a separate subgroup. In the hospital cohort, 72 (29.4%) patients died during hospitalization and 40 (36.0%) patients died in the intensive care unit cohort. In the hospital cohort, logistic regression analysis identified Acute Physiology and Chronic Health Evaluation II scores (1-point increments) (adjusted odds ratio [AOR], 1.18; 95% confidence interval [CI], 1.11-1.25; p = 0.003), corticosteroid use at the time a positive blood culture was drawn (AOR, 3.41; 95% CI, 1.96-5.93; p = 0.027), inadequate initial fluconazole dosing (AOR, 3.31; 95% CI, 1.83-6.00; p = 0.044), and retention of a central vein catheter (AOR, 4.85; 95% CI, 2.54-9.29; p = 0.015) as independent determinants of hospital mortality. In the intensive care unit cohort, logistic regression analysis identified Acute Physiology and Chronic Health Evaluation II scores (1-point increments) (AOR, 1.21; 95% CI, 1.14-1.29; p = 0.001), inadequate initial fluconazole dosing (AOR, 9.22; 95% CI, 2.15-19.79; p = 0.004), and retention of a central vein catheter (AOR, 6.21; 95% CI, 3.02-12.77; p = 0.011), as independent determinants of hospital mortality. For both cohorts the incremental presence of treatment-related risk factors was statistically associated with greater hospital mortality. CONCLUSIONS: Treatment-related factors, including retention of central vein catheters and inadequate initial fluconazole dosing, were associated with increased hospital mortality in patients with Candida bloodstream infections. These data suggest that optimization of initial antifungal therapy and removal of central vein catheters may improve the outcomes of patients with Candida bloodstream infections.

Soiling is a major source of power degradation in photovoltaic (PV) modules, with variable impact as a function of environmental conditions. For concentrated photovoltaic (CPV) modules the impact is greater due to requirements in preserving the optical path within the module. In an effort to reduce soiling a number of self-cleaning coatings have been developed and implemented in solar modules. Self-cleaning films are generally based on high (hydrophilic) or low (hydrophobic) surface energy materials that leverage extreme wetting behavior to reduce contamination, and/or photocatalytic materials that decompose contaminants with ultraviolet (UV) activation. In this study we explore a number of third-party coating materials to reduce soiling losses in Morgan Solar’s Sun Simba CPV modules. The primary objective is to identify coating solutions that are mechanically robust and effective in anti-soiling, as well as compatible with our materials and optical concentration architecture. In preliminary testing two products were compared with extreme wetting characteristics. The material 1 coating reduces soiling rates to 0.8-1.4%/month, whereas the material 2 coating failed mechanically and the module soiled at a rate of 6.6%/month as a consequence – the control module soiled at a rate of 4.1%/month for comparison. We followed-up with the deployment of a long-term study that will compare 4 self-cleaning/easy-to-clean products. The materials have been selected for their extreme wetting characteristics and suitable optical properties. Deposition parameters were optimized and the coated modules have been mounted for evaluation in the Mojave Desert, California.

The medium frequency interferometer (MFI) is the first direction-sensitive instrument to observe auroral radio emissions in the frequency range 2500-3000 kHz. The MFI has observed many auroral roar events since operations began at the Sondrestrom Research Facility near Kangerlussuaq, Greenland, in April 1999. The MFI data reveal that individual auroral roar events often propagate to the MFI from multiple directions and that the source locations show interesting time-variable features such as drifting and oscillations with a period of a few minutes in both azimuth and zenith angles. Most events have a direction of arrival from the local magnetic south, with the latitude distribution of the apparent source regions peaked near the poleward edge of the statistical auroral oval. The altitude distribution of apparent source locations has a bimodal form, which may be interpreted as evidence for two distinct well-separated sources, one on the topside F region and one on the bottomside.

The results of two surveys of arriving and departing air travelers at O'Hare and Midway airports in Chicago concerning their choice of ground access and egress modes are reported. The purpose of the surveys was to better understand the travelers' trip purpose, trip frequency, origin and destination location, and perception of rail rapid transit as an access mode, so that promotional programs can be developed to increase this transit use. For both airports, about 15 percent of all air travelers whose ground trip-ends fell within the Chicago Transit Authority’s (CTA’s) service area used rail transit for access and egress. Rail access has been provided to O'Hare (Northwest Corridor, Blue Line) since 1984 and to Midway (Southwest Corridor, Orange Line) since 1993. The CTA has undertaken targeted promotional campaigns to increase the overall diversion of automobile travelers in both corridors to rapid transit. Such improved access to the airport increases the potential for greater market penetration. Passenger characteristics and survey methods are summarized, and the two ground access surveys are compared. The importance of express transit service as a significant consideration for managers and designers of major airports is highlighted.

Colloidal quantum dots (CQDs) offer promise in flexible electronics, light sensing and energy conversion. These applications rely on rectifying junctions that require the creation of high-quality CQD solids that are controllably n-type (electron-rich) or p-type (hole-rich). Unfortunately, n-type semiconductors made using soft matter are notoriously prone to oxidation within minutes of air exposure. Here we report high-performance, air-stable n-type CQD solids. Using density functional theory we identify inorganic passivants that bind strongly to the CQD surface and repel oxidative attack. A materials processing strategy that wards off strong protic attack by polar solvents enabled the synthesis of an air-stable n-type PbS CQD solid. This material was used to build an air-processed inverted quantum junction device, which shows the highest current density from any CQD solar cell and a solar power conversion efficiency as high as 8%. We also feature the n-type CQD solid in the rapid, sensitive, and specific detection of atmospheric NO2. This work paves the way for new families of electronic devices that leverage air-stable quantum-tuned materials.

Solution processed colloidal quantum dot (CQD) solar cells have great potential for large area low-cost photovoltaics. However, light utilization remains low mainly due to the tradeoff between small carrier transport lengths and longer infrared photon absorption lengths. Here, we demonstrate a bottom-illuminated periodic nanostructured CQD solar cell that enhances broadband absorption without compromising charge extraction efficiency of the device. We use finite difference time domain (FDTD) simulations to study the nanostructure for implementation in a realistic device and then build proof-of-concept nanostructured solar cells, which exhibit a broadband absorption enhancement over the wavelength range of λ = 600 to 1100 nm, leading to a 31% improvement in overall short-circuit current density compared to a planar device containing an approximately equal volume of active material. Remarkably, the improved current density is achieved using a light-absorber volume less than half that typically used in the best planar devices.

Colloidal quantum dot photovoltaics combine low-cost solution processing with quantum size-effect tuning to match absorption to the solar spectrum. Rapid advances have led to certified solar power conversion efficiencies of over 7%. Nevertheless, these devices remain held back by a compromise in the choice of quantum dot film thickness, balancing on the one hand the need to maximize photon absorption, mandating a thicker film, and, on the other, the need for efficient carrier extraction, a consideration that limits film thickness. Here we report an architecture that breaks this compromise by folding the path of light propagating in the colloidal quantum dot solid. Using this method, we achieve a substantial increase in short-circuit current, ultimately leading to improved power conversion efficiency.

Colloidal quantum dot (CQD) solar cells combine solution-processability with quantum-size-effect tunability for low-cost harvesting of the sun's broad visible and infrared spectrum. The highest-performing colloidal quantum dot solar cells have, to date, relied on a depleted-heterojunction architecture in which an n-type transparent metal oxide such as TiO2 induces a depletion region in the p-type CQD solid. These devices have, until now, been limited by a modest depletion region depth produced in the CQD solid owing to limitations in the doping available in TiO2. Herein we report a new device geometry-one based on a donor-supply electrode (DSE)-that leads to record-performing CQD photovoltaic devices. Only by employing this new charge-extracting approach do we deepen the depletion region in the CQD solid and thereby extract notably more photocarriers, the key element in achieving record photocurrent and device performance. With the use of optoelectronic modeling corroborated by experiment, we develop the guidelines for building a superior CQD solar cell based on the DSE concept. We confirm that using a shallow-work-function terminal electrode is essential to producing improved charge extraction and enhanced performance.

We present a review of colloidal quantum dot photovoltaics, emphasizing advancements in the development of device architectures, materials engineering, and mutli-junction configurations in pursuit of high-efficiency, low-cost solar cells for eventual deployment in commercial applications.

Summary form only given. Earth's auroral ionosphere emits several types of spontaneous emissions, including auroral hiss, medium frequency burst, and roar. Auroral roar occurs at harmonics of the electron cyclotron frequency. The most commonly observed harmonic is 2fce, first reported in the 1970's. Since the 1990's, the 3fce harmonic has also been regularly observed from ground level. These emissions both favor pre-midnight magnetic local times and require darkness for observation at ground-level. Significant evidence has accumulated that they result from mode conversion of upper hybrid waves excited where the upper hybrid frequency matches the cyclotron harmonic. Satellite and rocket observations of the 2fce emission support that mechanism. Recently, two papers report observations of 4fce and 5fce emissions in Svalbard and in Antarctica. These higher harmonic emissions also favor pre-midnight magnetic local times but require sunlit ionosphere for observation. For all harmonics observed so far, the frequency scales linearly with the strength of the geomagnetic field at the observing station. Combining data from multiple stations allows estimation of source altitudes. Observations of the harmonics at a given station also provides a method for remotely sensing the ionospheric density.

Semiconductors with bandgaps in the near- to mid-infrared can harvest solar light that is otherwise wasted by conventional single-junction solar cell architectures. In particular, colloidal quantum dots (CQDs) are promising materials since they are cost-effective, processed from solution, and have a bandgap that can be tuned into the infrared (IR) via the quantum size effect. These characteristics enable them to harvest the infrared portion of the solar spectrum to which silicon is transparent. To date, IR CQD solar cells have been made using a wasteful and complex sequential layer-by-layer process. Here, we demonstrate ∼1 eV bandgap solar-harvesting CQD films deposited in a single step. By engineering a fast-drying solvent mixture for metal iodide-capped CQDs, we deposited active layers greater than 200 nm in thickness having a mean roughness less than 1 nm. We integrated these films into infrared solar cells that are stable in air and exhibit power conversion efficiencies of 3.5% under illumination by t...

Herein, a solution-processed, bottom-up-fabricated, nanowire network electrode is developed. This electrode features a ZnO template which is converted into locally connected, infiltratable, TiO2 nanowires. This new electrode is used to build a depleted bulk heterojunction solar cell employing hybrid-passivated colloidal quantum dots. The new electrode allows the application of a thicker, and thus more light-absorbing, colloidal quantum dot active layer, from which charge extraction of an efficiency comparable to that obtained from a thinner, planar device could be obtained.

To identify the determinants of hospital mortality among patients with septic shock receiving appropriate initial antibiotic treatment.A retrospective cohort study of hospitalized patients with blood culture positive septic shock (January 2002-December 2007).Barnes-Jewish Hospital, a 1,250-bed urban teaching hospital.Four hundred thirty-six consecutive patients with septic shock and a positive blood culture.Data abstraction from computerized medical records.Septic shock was associated with bloodstream infection due to Gram-negative bacteria (59.2%) and Gram-positive bacteria (40.8%). Two hundred twenty-four patients (51.4%) died during their hospitalization. The presence of infection attributed to antibiotic-resistant bacteria was similar for patients who survived and expired (22.6% vs. 20.1%; p = .516). Multivariate logistic regression analysis demonstrated that infection acquired in the intensive care unit (adjusted odds ratio 1.99; 95% confidence interval 1.52-2.60; p = .011) and increasing Acute Physiology and Chronic Health Evaluation II scores (one-point increments) (adjusted odds ratio 1.11; 95% confidence interval 1.09-1.14; p.001) were independently associated with a greater risk of hospital mortality, whereas infection with methicillin-susceptible Staphylococcus aureus (adjusted odds ratio 0.32; 95% confidence interval 0.20-0.52; p = .017) was independently associated with a lower risk of hospital mortality. Patients infected with methicillin-susceptible Staphylococcus aureus infections were statistically younger and had lower Charlson comorbidity and Acute Physiology and Chronic Health Evaluation II scores compared to patients with non-methicillin-susceptible Staphylococcus aureus infections.Among patients with septic shock who receive appropriate initial antibiotic treatment, acquisition of infection in the intensive care unit and severity of illness appear to be the most important determinants of clinical outcome.

Colloidal quantum dot (CQD) films allow large-area solution processing and bandgap tuning through the quantum size effect. However, the high ratio of surface area to volume makes CQD films prone to high trap state densities if surfaces are imperfectly passivated, promoting recombination of charge carriers that is detrimental to device performance. Recent advances have replaced the long insulating ligands that enable colloidal stability following synthesis with shorter organic linkers or halide anions, leading to improved passivation and higher packing densities. Although this substitution has been performed using solid-state ligand exchange, a solution-based approach is preferable because it enables increased control over the balance of charges on the surface of the quantum dot, which is essential for eliminating midgap trap states. Furthermore, the solution-based approach leverages recent progress in metal:chalcogen chemistry in the liquid phase. Here, we quantify the density of midgap trap states in CQD solids and show that the performance of CQD-based photovoltaics is now limited by electron-hole recombination due to these states. Next, using density functional theory and optoelectronic device modelling, we show that to improve this performance it is essential to bind a suitable ligand to each potential trap site on the surface of the quantum dot. We then develop a robust hybrid passivation scheme that involves introducing halide anions during the end stages of the synthesis process, which can passivate trap sites that are inaccessible to much larger organic ligands. An organic crosslinking strategy is then used to form the film. Finally, we use our hybrid passivated CQD solid to fabricate a solar cell with a certified efficiency of 7.0%, which is a record for a CQD photovoltaic device.

We discuss strategies to reduce midgap trap state densities in colloidal quantum dot films and requirements to control doping type and magnitude. We demonstrate that these improvements result in colloidal quantum dot solar cells with certified 7.0% efficiency.

The highest-performing colloidal quantum dot (CQD) photovoltaics (PV) reported to date have relied on high-temperature (500°C) annealing of electron-accepting TiO2. Room-temperature processing reduces energy payback time and manufacturing cost, enables flexible substrates, and permits tandem solar cells that integrate a small-bandgap back cell atop a low-thermal-budget larger-bandgap front cell. Here we report an electrode strategy that enables a depleted-heterojunction CQD PV device to be fabricated entirely at room temperature. We find that simply replacing the high-temperature-processed TiO2 with a sputtered version of the same material leads to poor performance due to the low mobility of the sputtered oxide. We develop instead a two-layer donor-supply electrode (DSE) in which a highly doped, shallow work function layer supplies a high density of free electrons to an ultrathin TiO2 layer via charge-transfer doping. Using the DSE we build all-room-temperature-processed small-bandgap (1 eV) colloidal quantum dot solar cells having 4% solar power conversion efficiency and high fill factor. These 1 eV bandgap cells are suitable for use as the back junction in tandem solar cells. The DSE concept, combined with control over TiO2 stoichiometry in sputtering, provides a much-needed tunable electrode to pair with quantum-size-effect CQD films.

Healthcare-associated pneumonia patients have worse outcomes and a different microbiologic profile than those with community-acquired pneumonia, including a greater risk for multidrug-resistant (MDR) organism infection. Risks include hospitalization for 2 or more days within 90 days, presentation from a nursing home or long-term care facility, attending a hospital or hemodialysis clinic, receiving intravenous therapy within 30 days, and immunosuppression. Ability to predict infection with MDR organisms varies, and the relative frequency of MDR organisms varies by geographic region. Initial treatment is broad-spectrum empiric antibiotics.

The Earth’s aurorae radiate away up to 1% of their energy in the form of radio waves, called Auroral Kilometric Radiation (AKR). The mechanism responsible for the emission, the electron cyclotron maser (ECM), produces similar emissions at other planets, in the solar atmosphere, and in astrophysical systems. AKR was not unambiguously identified until the 1970’s because its detection requires a suitably instrumented satellite. The ECM theory predicts radiation beamed outward that cannot penetrate the increasing magnetic field and electron density near the Earth. Nevertheless, there have been observations over the years of AKR-like radio signals detected by ground-based, rocket-borne, and low-earth orbiting satellite-borne instruments, raising the question of whether a mechanism exists by which AKR can penetrate to low altitudes. Here we show the first unambiguous evidence that AKR indeed penetrates to low altitudes on occasions. We identified three examples of AKR-like emissions detected with a ground-based radio receiver at South Pole Station, Antarctica, during a 9-day interval in July, 2004, when the Geotail satellite, monitoring AKR, had a field of view including the auroral field lines above the station. The AKR-like emissions detected at ground-level have the same frequenc–time structure as simultaneous AKR emissions detected on Geotail 115,000-190,000 km away from the Earth. Slight differences in the frequency extent of the emissions at the two locations can be explained by, for example, plasmaspheric screening of the emissions detected by Geotail. These observations represent the first coincident detections of AKR in space and on the ground. They require the existence of an as-yet unidentified mechanism to produce the ground-level emissions which are not predicted by ECM theory, they suggest that previous AKR-like emissions observed at low altitudes may indeed be AKR, and they require revision of the widely-held view that AKR is only detectable from space.

Early therapy of sepsis involving fluid resuscitation and antibiotic administration has been shown to improve patient outcomes. A proactive tool to identify patients at risk for developing sepsis may decrease time to interventions and improve patient outcomes. The objective of this study was to evaluate whether the implementation of an automated sepsis screening and alert system facilitated early appropriate interventions.Prospective, observational, pilot study.Six medicine wards in Barnes-Jewish Hospital, a 1250-bed academic medical center.Patients identified by the sepsis screen while admitted to a medicine ward were included in the study. A total of 300 consecutive patients were identified comprising the nonintervention group (n=200) and the intervention group (n=100).A real-time sepsis alert was implemented for the intervention group, which notified the charge nurse on the patient's hospital ward by text page.Within 12 hrs of the sepsis alert, interventions by the treating physicians were assessed, including new or escalated antibiotics, intravenous fluid administration, oxygen therapy, vasopressors, and diagnostic tests. After exclusion of patients without commitment to aggressive management, 181 patients in the nonintervention group and 89 patients in the intervention group were analyzed. Within 12 hrs of the sepsis alert, 70.8% of patients in the intervention group had received≥1 intervention vs. 55.8% in the nonintervention group (p=.018). Antibiotic escalation, intravenous fluid administration, oxygen therapy, and diagnostic tests were all increased in the intervention group. This was a single-center, institution- and patient-specific algorithm.The sepsis alert developed at Barnes-Jewish Hospital was shown to increase early therapeutic and diagnostic interventions among nonintensive care unit patients at risk for sepsis.

Background Candida represents the most common cause of invasive fungal disease, and candidal blood stream infections (CBSI) are prevalent in the ICU. Inappropriate antifungal therapy (IAT) is known to increase a patient's risk for death. We hypothesized that in an ICU cohort it would also adversely affect resource utilization. Methods We retrospectively identified all patients with candidemia on or before hospital day 14 and requiring an ICU stay at Barnes-Jewish Hospital between 2004 and 2007. Hospital length of stay following culture-proven onset of CBSI (post-CBSI HLOS) was primary and hospital costs secondary endpoints. IAT was defined as treatment delay of ≥24 hours from candidemia onset or inadequate dose of antifungal agent active against the pathogen. We developed generalized linear models (GLM) to assess independent impact of inappropriate therapy on LOS and costs. Results Ninety patients met inclusion criteria. IAT was frequent (88.9%). In the IAT group antifungal delay ≥24 hours occurred in 95.0% and inappropriate dosage in 26.3%. Unadjusted hospital mortality was greater among IAT (28.8%) than non-IAT (0%) patients, p = 0.059. Both crude post-CBSI HLOS (18.4 ± 17.0 vs. 10.7 ± 9.4, p = 0.062) and total costs ($66,584 ± $49,120 vs. $33,526 ± $27,244, p = 0.006) were higher in IAT than in non-IAT. In GLMs adjusting for confounders IAT-attributable excess post-CBSI HLOS was 7.7 days (95% CI 0.6-13.5) and attributable total costs were $13,398 (95% CI $1,060-$26,736). Conclusions IAT of CBSI, such as delays and incorrect dosing, occurs commonly. In addition to its adverse impact on clinical outcomes, IAT results in substantial prolongation of hospital LOS and increase in hospital costs. Efforts to enhance rates of appropriate therapy for candidemia may improve resource use.

Study Objectives. To evaluate the impact of inappropriate therapy—defined as delayed antifungal therapy beyond 24 hours from culture collection, inadequate antifungal dosage, or administration of an antifungal to which an isolate was considered resistant—on postculture hospital length of stay and costs, and to evaluate the relationship between modifiable risk factors, including failure to remove a central venous catheter, antifungal delay, and inadequate dosage, for an additive effect on hospital length of stay and costs. Design. Single-center retrospective cohort study. Setting. 1250-bed academic medical center. Patients. One hundred sixty-seven consecutive adult patients admitted between January 2004 and May 2006 with culture-confirmed Candida bloodstream infections that occurred within 14 days of hospital admission and who received at least one dose of antifungal treatment. Measurements and Main Results. Patients were stratified according to appropriateness of antifungal therapy. Appropriate therapy was defined as initiation of an antifungal to which the isolated pathogen was sensitive in vitro within 24 hours of positive culture collection, in addition to receipt of an adequate dose as recommended by the Infectious Diseases Society of America and the antifungal package insert. Postculture length of stay was the primary outcome and hospital costs the secondary outcome. An evaluation of modifiable risk factors was performed separately. Data were analyzed for 167 patients (22 in the appropriate therapy group and 145 in the inappropriate therapy group). Postculture length of stay was shorter in the appropriate therapy group (mean 7 vs 10.4 days, p=0.037). This correlated with total hospital costs that were lower in the appropriate therapy group (mean $15,832 vs $33,021, p

The composition of extracellular material produced by non-mucoid strains of Pseudomonas aeruginosa differed when grown on surfaces that either did or did not induce the formation of slime under conditions where the medium was identical. The nature of the changes in protein composition indicated that protein expression differed in the course of growth on the two surfaces, and hence that there were physiological consequences associated with growth under conditions which do or do not lead to slime formation. The compositional differences also included elevated levels in extracellular material from the slimy colonies of two virulence factors, protease and rhamnolipids.

The 352 MHz RF accelerating systems for the SOLEIL Booster (BO) and Storage Ring (SR) are in operation since mid 2006. In the BO, a 5-cell copper cavity of the CERN-LEP type is powered with a 35 kW solid state amplifier. In the SR, the required RF accelerating voltage (up to 4.4 MV) and power (560 kW at full beam current of 500 mA) will be provided by two cryomodules, each containing a pair of superconducting cavities, specifically designed for SOLEIL. The parasitic impedances of the high order modes are strongly attenuated by means of four coaxial couplers, located on the tube connecting the two cavities. The first cryomodule is operational, while the second one, which is being constructed by ACCEL (Germany), will be implemented beginning of 2008. Both cryomodules are cooled down to 4.2 K with liquid helium from a single 350 W liquefier and each cavity is powered by a 180 kW solid state amplifier. Using a single cryomodule and two amplifiers, the first objective of storing 300 mA stable beam was successfully achieved in 2006. The RF system commissioning and operation results are reported.