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Thermophotovoltaics, devices that convert thermal infrared photons to electricity, offer a key pathway for a variety of critical renewable energy technologies including thermal energy storage, waste heat recovery, and direct solar-thermal power generation. However, conventional far-field devices struggle to generate reasonable powers at lower temperatures. Near-field thermophotovoltaics provide a pathway to substantially higher powers by leveraging photon tunneling effects. Here a large area near-field thermophotovoltaic device is presented, created with an epitaxial co-fabrication approach, that consists of a self-supported 0.28 cm 2 emitter-cell pair with a 150 nm gap. The device generates 1.22 mW at 460 °C, a 25-fold increase over the same cell measured in a far-field configuration. Furthermore, the near-field device demonstrates short circuit current densities greater than the far-field photocurrent limit at all the temperatures tested, confirming the role of photon tunneling effects in the performance enhancement. Modeling suggests several practical directions for cell improvements and further increases in power density. These results highlight the promise of near-field thermophotovoltaics, especially for low temperature applications., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)

The direct epitaxial growth of high-quality III-V semiconductors on Si is a challenging materials science problem with a number of applications in optoelectronic devices, such as solar cells and on-chip lasers. We report the reduction of dislocation density in GaAs solar cells grown directly on nanopatterned V-groove Si substrates by metal-organic vapor-phase epitaxy. Starting from a template of GaP on V-groove Si, we achieved a low threading dislocation density (TDD) of 3 × 10 6 cm -2 in the GaAs by performing thermal cycle annealing of the GaAs followed by growth of InGaAs dislocation filter layers. This approach eliminates the need for a metamorphic buffer to directly integrate low-TDD GaAs on Si. We used these low-TDD GaAs/V-groove Si templates to grow GaAs double heterostructures that had a minority carrier lifetime of 5.7 ns, as measured by time-resolved photoluminescence, a value consistent with the material quality associated with a 20%+ efficient GaAs solar cell. However, front-junction GaAs solar cells grown on these low-TDD substrates produced a conversion efficiency of only 6.6% without an antireflection coating. Electron channeling contrast imaging measurements on this cell showed a high density of misfit dislocations at the interface between the AlInP/GaInP window layer and the GaAs absorber and between the GaAs absorber and the GaInP back surface field (BSF), likely causing a high surface recombination velocity and thus poor performance. We showed that we could reduce (and in the case of the BSF, eliminate) these dislocations by employing an AlGaAs-based window layer and BSF. Compared to GaInP, AlGaAs has dislocation glide properties that are more similar to those of GaAs, resulting in more even threading dislocation glide between layers. AlGaAs passivation improved the external quantum efficiency and open-circuit voltage of the devices, but the overall device performance was still low at an efficiency of 7.7% without an antireflection coating, likely due to cracking in the devices. This work demonstrates a route to high material quality in GaAs grown directly on Si that can be used for the production of III-V/Si optoelectronic devices.

There is no consensus on second allogeneic stem cell transplantation (alloSCT) indications in patients with hematologic malignancies relapsing after a first alloSCT. In historic publications, a very high non-relapse mortality (NRM) has been described, arguing against performing a second alloSCT. We analysed the outcome of 3356 second alloSCTs performed 2011-21 following a hematologic malignancy relapse. Outcomes at two years after second alloSCT were: NRM 22%, relapse incidence 50%, overall survival 38%, and progression-free survival 28%. Key risk factors for increased NRM were: older age, low performance score, high disease-risk-index, early relapse after the first alloSCT, unrelated/haploidentical donor, and GVHD before second alloSCT. Any type of GVHD after first alloSCT was also important risk factor for acute GVHD and chronic GVHD after second alloSCT. There was a preferential use of a different donor (80%) at second alloSCT from first alloSCT. However, in multivariate analysis, the use of the same alloSCT donor for second alloSCT vs. a different donor was not associated with any of the survival or GVHD endpoints. We show considerably improved outcome as compared to historic reports. These current data support a wider use of second alloSCT and provide risk factors for NRM that need to be considered., (© 2024. The Author(s).)

Thermophotovoltaics (TPVs) convert predominantly infrared wavelength light to electricity via the photovoltaic effect, and can enable approaches to energy storage 1,2 and conversion 3-9 that use higher temperature heat sources than the turbines that are ubiquitous in electricity production today. Since the first demonstration of 29% efficient TPVs (Fig. 1a) using an integrated back surface reflector and a tungsten emitter at 2,000 °C (ref. 10 ), TPV fabrication and performance have improved 11,12 . However, despite predictions that TPV efficiencies can exceed 50% (refs. 11,13,14 ), the demonstrated efficiencies are still only as high as 32%, albeit at much lower temperatures below 1,300 °C (refs. 13-15 ). Here we report the fabrication and measurement of TPV cells with efficiencies of more than 40% and experimentally demonstrate the efficiency of high-bandgap tandem TPV cells. The TPV cells are two-junction devices comprising III-V materials with bandgaps between 1.0 and 1.4 eV that are optimized for emitter temperatures of 1,900-2,400 °C. The cells exploit the concept of band-edge spectral filtering to obtain high efficiency, using highly reflective back surface reflectors to reject unusable sub-bandgap radiation back to the emitter. A 1.4/1.2 eV device reached a maximum efficiency of (41.1 ± 1)% operating at a power density of 2.39 W cm -2 and an emitter temperature of 2,400 °C. A 1.2/1.0 eV device reached a maximum efficiency of (39.3 ± 1)% operating at a power density of 1.8 W cm -2 and an emitter temperature of 2,127 °C. These cells can be integrated into a TPV system for thermal energy grid storage to enable dispatchable renewable energy. This creates a pathway for thermal energy grid storage to reach sufficiently high efficiency and sufficiently low cost to enable decarbonization of the electricity grid., (© 2022. The Author(s).)

Wide-band gap metal halide perovskites are promising semiconductors to pair with silicon in tandem solar cells to pursue the goal of achieving power conversion efficiency (PCE) greater than 30% at low cost. However, wide-band gap perovskite solar cells have been fundamentally limited by photoinduced phase segregation and low open-circuit voltage. We report efficient 1.67-electron volt wide-band gap perovskite top cells using triple-halide alloys (chlorine, bromine, iodine) to tailor the band gap and stabilize the semiconductor under illumination. We show a factor of 2 increase in photocarrier lifetime and charge-carrier mobility that resulted from enhancing the solubility of chlorine by replacing some of the iodine with bromine to shrink the lattice parameter. We observed a suppression of light-induced phase segregation in films even at 100-sun illumination intensity and less than 4% degradation in semitransparent top cells after 1000 hours of maximum power point (MPP) operation at 60°C. By integrating these top cells with silicon bottom cells, we achieved a PCE of 27% in two-terminal monolithic tandems with an area of 1 square centimeter., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

: The occasional ingestion of 3,4-methylenedioxy-N-methylamphetamine (MDMA) presents serious risks of side effects including death through multivisceral failure in a context of serotonin syndrome. The significant increasing evolution of illicit MDMA street dosages over the past 2 decades and the difficulty for physicians to know what quantity the patients may have consumed, make MDMA a drug with unpredictable effects. Through this case report of a 16-year-old Caucasian, we made use of a unique and nationwide French health monitoring system called TREND (Recent Trends and New Drugs)-SINTES (National Identification System for Drugs and Substances), which, combined with the hair follicle test, can assist medical practitioners in rapidly establishing a precise diagnosis and consequently provide the most appropriate treatment for each individual case in a timely manner.

Space power systems require photovoltaics that are lightweight, efficient, reliable, and capable of operating for years or decades in space environment. Current solar panels use planar multijunction, III-V based solar cells with very high efficiency, but their specific power (power to weight ratio) is limited by the added mass of radiation shielding (e.g., coverglass) required to protect the cells from the high-energy particle radiation that occurs in space. Here, we demonstrate that III-V nanowire-array solar cells have dramatically superior radiation performance relative to planar solar cell designs and show this for multiple cell geometries and materials, including GaAs and InP. Nanowire cells exhibit damage thresholds ranging from ∼10-40 times higher than planar control solar cells when subjected to irradiation by 100-350 keV protons and 1 MeV electrons. Using Monte Carlo simulations, we show that this improvement is due in part to a reduction in the displacement density within the wires arising from their nanoscale dimensions. Radiation tolerance, combined with the efficient optical absorption and the improving performance of nanowire photovoltaics, indicates that nanowire arrays could provide a pathway to realize high-specific-power, substrate-free, III-V space solar cells with substantially reduced shielding requirements. More broadly, the exceptional reduction in radiation damage suggests that nanowire architectures may be useful in improving the radiation tolerance of other electronic and optoelectronic devices.

Necrotizing autoimmune myopathy (NAM) is a group of acquired myopathies characterized by prominent myofiber necrosis with little or no muscle inflammation. Recently, researchers identified autoantibodies (aAb) against 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) in patients with NAM, especially in statin-exposed patients. Here we report what is to our knowledge the first European cohort of patients with NAM.The serum of 206 patients with suspicion of NAM was tested for detection of anti-HMGCR aAb using an addressable laser bead immunoassay. Forty-five patients were found to be anti-HMGCR positive. Their mean age was 48.9 ± 21.9 years and the group was predominantly female (73.3%). Statin exposure was recorded in 44.4% of patients. Almost all patients had a muscular deficit (97.7%), frequently severe (Medical Research Council [MRC] 5 ≤3 in 75.5%). Subacute onset (<6 mo) was noted for most of them (64.4%). Nevertheless, 3 patients (6.6%) had a slowly progressive course over more than 10 years. Except for weight loss (20%), no extramuscular sign was observed. The mean CK level was high (6941 ± 8802 IU/L) and correlated with muscle strength evaluated by manual muscle testing (r = -0.37, p = 0.03). Similarly, anti-HMGCR aAb titers were correlated with muscular strength (r = -0.31; p = 0.03) and CK level (r = 0.45; p = 0.01). Mean duration of treatment was 34.1 ± 40.8 months, and by the end of the study no patient had been able to stop treatment.This study confirms the observation and description of anti-HMGCR aAb associated with NAM. The majority of patients were statin naive and needed prolonged treatments. Some patients had a dystrophic-like presentation. Anti-HMGR aAb titers correlated with CK levels and muscle strength, suggesting their pathogenic role.

Therapeutic botulinum neurotoxin type A preparations have found an increasing number of clinical uses for a large variety of neuromuscular disorders and dermatological conditions. The accurate determination of potency in the clinical application of botulinum toxins is critical to ensuring clinical efficacy and safety, and is currently achieved by using a lethal dose (LD50) assay in mice. Ethical concerns and operational constraints associated with this assay have prompted the development of alternative assay systems that could potentially lead to its replacement. As one such alternative, we describe the development and evaluation of a novel ex vivo assay (the Intercostal Neuromuscular Junction [NMJ] Assay), which uses substantially fewer animals and addresses ethical concerns associated with the LD50 assay. The assay records the decay of force from electrically-stimulated muscle tissue sections in response to the toxin, and thus combines the important mechanisms of receptor binding, translocation, and the enzymatic action of the toxin molecule. Toxin application leads to a time-related and dose-related reduction in contractile force. A regression model describing the relationship between the applied dose and force decay was determined statistically, and was successfully tested as able to correctly predict the potency of an unknown sample. The tissue sections used were found to be highly reproducible, as determined through the innervation pattern and the localisation of NMJs in situ. Furthermore, the efficacy of the assay protocol to successfully deliver the test sample to the cellular target sites, was critically assessed by using molecular tracer molecules.

Background: The MCF7 breast cancer cell line is a cellular model for breast cancer studies and marker discovery. Therefore, a better knowledge of its proteome is a prerequisite for a more efficient use of this model., Materials and Methods: Proteins expressed during the exponential growth phase of MCF7 cells were analyzed and mapped using two-dimensional gel electrophoresis and mass spectrometry., Results: From the spots excised from preparative gels of whole-cell extracts, a subset of 368 different polypeptides, corresponding to 249 different proteins, was identified. These polypeptides were positioned on a silver-stained gel to construct a reference map., Conclusion: The data allowed the construction of the most extensive reference map for MCF7 published to date, with 189 novel proteins, which had not been previously listed on maps, and are now accessible on World 2D-PAGE database, providing a basis for further studies on MCF7., (Copyright© 2006 International Institute of Anticaner Research (Dr. John G. Delinassios), All rights reserved.)

Basic science research in hematology has been determining the functions of gene products using classical approaches that typically involve studying one or a few genes at a time. Proteomics, defined as the study of protein properties on a large scale, provides tools to globally analyze malignant hematologic cells. A major challenge in cancer therapy is the identification of drugs that kill tumor cells while preserving normal cells. Differential display via proteomics enables analysis of direct as well as side-effects of drugs at a molecular level. Proteomics also allows a better understanding of cell signaling pathways involved during apoptosis in hematologic cells. Storing the information in a 2D electrophoresis database enhances the efficiency of proteome research on malignant cells. Finally, the work needed to be carried out on proteomic analysis prior to routine clinical adoption is discussed, and the necessity for multi-institutional collaborations is emphasized.

The isolation and characterization of homogeneous arginine kinase from the cockroach is reported. The purification protocol produces 6.6 mg of pure enzyme from 6.8 g of whole cockroach. The purified enzyme cross-reacts with a heterologous antibody and monoclonal antibody against arginine kinase from the shrimp. Both antibody preparations also cross-react with extracts from several species known to contain monomeric arginine kinase, but fail to react with extracts from organisms containing dimeric arginine kinase. Cockroach arginine kinase has a molecular mass of approximately 43,000 determined from measurements by gel filtration and gel electrophoresis. Compared with other arginine kinases, the enzyme from the cockroach is relatively thermostable (50% activity retained at 50 degrees C for 10 min) and has a pH optima of 8.5 and 6.5-7.5, for the forward and reverse reactions, respectively. Treatment with 5,5'dithiobis[2-nitrobenzoic acid] indicates that arginine kinase has a single reactive sulfhydryl group and, interestingly, the reaction is biphasic. The Michaelis constants for the phosphagen substrates, arginine: 0.49 mM, phosphoarginine: 0.94 mM, and nucleotide substrates MgATP: 0.14 mM, MgADP: 0.09 mM, are in the range reported for other arginine kinases. A 1% solution of pure enzyme has an absorbance of 7.0 at 280 nm. Calculations based on circular dichroic spectra indicate that arginine kinase from the cockroach has 12% alpha-helical structure. The intrinsic protein fluorescence emission maximum at 340 nm suggests that tryptophan residues are below the surface of the protein and not exposed to solvent. Arginine kinase from the cockroach and shrimp are known to be deleterious immunogens towards humans. The availability of pure protein, its characterization and potential regulation of activity, will be useful in developing agents to control the cockroach population and its destructive role in agriculture and human health., (Copyright 2004 Wiley-Liss, Inc.)

We have examined the fluorescence properties and acrylamide quenching of calcium-loaded (holo) and calcium-depleted (apo) alpha-lactalbumin (alpha-LA) as a function of guanidine hydrochloride (GDN/HCl) concentration. The spectral changes accompanying increasing GDN/HCl are consistent with protein unfolding and a release of internal fluorescence quenching, which occurs among the three tryptophan residues located in the region of the so-called "tertiary fold." Values for the intrinsic fluorescence emission, the wavelength maximum of the emission, the Stern/Volmer dynamic quench constant, and the static quench constant are consistent with a significant stabilization effect by calcium against protein unfolding. The dynamic quench constant of apo-alpha-LA increases fourfold to its maximum, in the transition from the native state to protein in 1.5 M GDN/HCl. The dynamic quench constant for holo-alpha-LA remains unchanged until exposed to 2.5 M GDN/HCl, but increases by threefold with addition denaturant to 4 M GDN/HCl. The static quench constant of the apo-protein in the native solvent, approximately 0.2 M(-1), declines to zero in 1 M denaturant, where the molten globule folding intermediate is most populated. A more protracted denaturant-dependent decline in the static quench constant occurs for the holo-protein. Sharp increase in the static quenching occurs for apo-alpha-LA and holo-alpha-LA above 1.5 M GDN/HCl and 3.5 M GDN/HCl, respectively. The results for apo-alpha-LA in dilute GDN/HCl suggest that acrylamide can penetrate the protein molecule (as judged by the collision quenching) but is unable to form a stable complex within the quenching domain for the tryptophans (as judged by the absence of the static quench constant). It seems reasonable to suggest that the protein folding intermediate which occurs in dilute denaturant represents a structure in which the tryptophans are, on average, more accessible to collisional quenching but sufficiently compact to prevent formation of a stable, dark equilibrium complex with acrylamide., (Copyright 2000 Academic Press.)

Human keratinocytes were cultured on plasma copolymers (PCPs), self-assembled monolayers (SAMs), and tissue culture poly(styrene) (TCPS). Plasma copolymerization was used to deposit films with controlled concentrations of carboxylic acid functional groups (<5%). Human keratinocytes were cultured onto these PCP surfaces, TCPS, and collagen I. A hydrocarbon plasma polymer surface was used as the negative control. Keratinocyte attachment was measured at 24 h and cell proliferation and growth at 3 and 7 days using optical microscopy and DNA concentrations. The PCP surfaces were compared with two SAM systems comprising pure acid and pure hydrocarbon functionalities, and pure gold was used as a control surface. PCP surfaces containing carboxylic acid functionalities promoted keratinocyte attachment. The level of attachment on these surfaces was comparable to that seen on collagen I, a preferred substratum for the culturing of keratinocytes. After several days in culture the cells were well attached and proliferative, forming confluent sheets of keratinocytes. This result was confirmed by DNA assays that suggested the acid PCP surfaces were performing as well as collagen I. Keratinocytes attached well to gold and acid-terminated SAMs but attached poorly to methyl-terminated SAMs. The acid functionality also promoted proliferation and growth of keratinocytes after several days in culture. DNA assays revealed that keratinocyte growth on the acid surface was higher than on collagen I., (Copyright 1999 John Wiley & Sons, Inc.)

Arginine kinase from the tail muscle of the Gulf shrimp (Penaeus aztecus) was purified to apparent homogeneity, using a rapid, high-yield method. The protein exhibits a molecular weight of 40 kDa according to the methods of gel filtration and gel electrophoresis in sodium dodecyl sulfate, also indicating that arginine kinase from shrimp is a monomer. The amino acid content of arginine kinase from shrimp is similar to arginine kinases from several species and to creatine kinase from rabbit muscle. Arginine kinase derivatized at the reactive sulfhydryl with 2-(4'-(iodoacetamido)anilino)naphthalene-6-sulfonic acid exhibits significant changes in fluorescence anisotropy only in the presence of the guanidino substrate and the so-called "dead-end complex" containing arginine + MgADP. Several compounds structurally similar to arginine, e.g., ornithine do not interact with arginine kinase, suggesting a narrow specificity for substrate binding. The most suitable description of the decay of the fluorescence of arginine kinase derivatized with 5-[(((acetyl)-amino)ethyl)amino]naphthalene-1-sulfonate (AEDANS-AK), from among discrete and distributed models, is a triple exponential discrete decay. The presence of the dead-end complex only marginally increases the rate of decay, but significantly shifts the magnitude of the preexponentials (amplitudes) between the two major decay components. One interpretation of these results is that multiple conformational isomers may occur, in which the relative concentrations are dependent upon the presence of the dead-end complex. Measurement of the time-dependent anisotropy decay of AEDANS-AK reveals a two-term decay law with rotational correlation times of 0.88 and 15.2 ns. The slower component is close to the theoretical value of 16.7 ns for an isotropic rotator of the molecular mass of arginine kinase. This finding suggests that the overall conformation of arginine kinase may differ considerably from the prolate ellipsoidal subunits of the functionally analogous creatine kinase.

The unfolding transition of monomeric arginine kinase from shrimp was examined in a multiparameter equilibrium approach. Parameters investigated included catalytic activity, circular dichroism, intrinsic fluorescence characteristics including acrylamide quenching, and steady-state anisotropy of arginine kinase derivatized at the reactive cysteine with fluorescent dye 5-[[[(iodoacetyl)amine]ethyl]amino]-naphthalene-1-sulfonic acid. The time course of electrophoretic patterns in urea gradient gels was also determined. Midpoints of the transitions varied considerably depending upon the parameter, indicating the presence of populated intermediates. Significant unfolding began after 2 M urea with most secondary and tertiary structure eliminated in 5 M urea. In dilute denaturant, arginine kinase exhibited a small increase in specific activity and physical properties characteristic of a protein with collapsed structure, including an increase in alpha-helical content, a decrease in intrinsic fluorescence (without a shift in the emission maximum), an increase in anisotropy, and a decrease in fractional accessibility by tryptophan to acrylamide quenching. The electrophoretic pattern of arginine kinase in urea gradient gels is consistent with the presence of a compact conformation in dilute denaturant. The results indicate the existence of a contracted overall conformation in dilute urea. The persistence of catalytic activity suggests this structure may be a functional molecular isoform, but the obvious differences in structure between the native state and the conformation of arginine kinase in 0.5 M urea raise the question of whether such isoforms may also be a type of folding intermediate.

(1) A single subunit and both subunits of creatine kinase from rabbit muscle was derivatized at the active site with the thiol-specific reagent 2-(4'-(iodoacetamido)anilino)-naphthalene-6-sulfonic acid. (2) The highly biphasic kinetics of the labelling reaction were characterized from measurements of activity, steady-state fluorescence and anisotropy. Derivatization of one thiol and both thiols resulted in 48 and 100% inhibition, respectively. The dead-end complex (DEC), consisting of creatine, MgADP and protein, inhibited the rate, but not the extent, of derivatization and resulted in a 2-fold increase in fluorescence. (3) The fluorescence of singlylabelled (1AANS/CK) and doublylabelled (2AANS/CK) protein exhibited three discrete lifetime components or a two-term Lorentzian distribution. The decay laws for both preparations were not remarkably different, except that, unlike 1AANS/CK, the longer decay component of 2AANS/CK was distributed, which narrowed in the presence of the DEC. (4) The steady-state anisotropies of 1AANS/CK and 2AANS/CK at 25 degrees C were 0.305 and 0.240, respectively. It was concluded that the fast reacting site was immobile and the slow reacting site was flexible. Kinetics of labelling and anisotropy emission spectra indicated that the DEC immobilized the flexible site. (5) The anisotropy decay of 1AANS/CK with and without the DEC was described by a rotational correlation time of about 50 ns, characteristic of the molecular rotation of the CK dimer. At least two terms were required to fit the data for 2AANS/CK, indicating additional segmental motion which was eliminated upon formation of the DEC. (6) Energy transfer from tryptophans to AANS indicated movement of approx. 3 A accompanying formation of the DEC.