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Purpose Single-agent gemcitabine became standard first-line treatment for advanced pancreatic cancer after demonstration of superiority compared with fluorouracil. The Gruppo Italiano Pancreas 1 randomized phase III trial aimed to compare gemcitabine plus cisplatin versus gemcitabine alone (ClinicalTrials.gov ID NCT00813696). Patients and Methods Patients with locally advanced or metastatic pancreatic cancer, age 18 to 75 years, and Karnofsky performance status (KPS) ≥ 50, were randomly assigned to receive gemcitabine (arm A) or gemcitabine plus cisplatin (arm B). Arm A: gemcitabine 1,000 mg/m2 weekly for 7 weeks, and, after a 1-week rest, on days 1, 8, and 15 every 4 weeks. Arm B: cisplatin 25 mg/m2 added weekly to gemcitabine, except cycle 1 day 22. Primary end point was overall survival. To have 8% power of detecting a 0.74 hazard ratio (HR) of death, with bilateral α .05, 355 events were needed and 400 patients planned. Results Four hundred patients were enrolled (arm A: 199; arm B: 201). Median age was 63, 59% were male, 84% had stage IV, and 83% had KPS ≥ 80. Median overall survival was 8.3 months versus 7.2 months in arm A and B, respectively (HR, 1.10; 95% CI, 0.89 to 1.35; P = .38). Median progression-free survival was 3.9 months versus 3.8 months in arm A and B, respectively (HR, 0.97; 95% CI, 0.80 to 1.19; P = .80). The objective response rate was 10.1% in A and 12.9% in B (P = .37). Clinical benefit was experienced by 23.0% in A and 15.1% in B (P = .057). Combination therapy produced more hematologic toxicity, without relevant differences in nonhematologic toxicity. Conclusion The addition of weekly cisplatin to gemcitabine failed to demonstrate any improvement as first-line treatment of advanced pancreatic cancer.

The direct search for dark matter is entering a period of increased sensitivity to the hypothetical Weakly Interacting Massive Particle (WIMP). One such technology that is being examined is a scintillation only noble liquid experiment, MiniCLEAN. MiniCLEAN utilizes over 500 kg of liquid cryogen to detect nuclear recoils from WIMP dark matter and serves as a demonstration for a future detector of order 50 to 100 tonnes. The liquid cryogen is interchangeable between argon and neon to study the A2 dependence of the potential signal and examine backgrounds. MiniCLEAN utilizes a unique modular design with spherical geometry to maximize the light yield using cold photomultiplier tubes in a single-phase detector. Pulse shape discrimination techniques are used to separate nuclear recoil signals from electron recoil backgrounds. MiniCLEAN will be spiked with additional 39Ar to demonstrate the effective reach of the pulse shape discrimination capability. Assembly of the experiment is underway at SNOLAB and an update on the project is given., Los Alamos National Laboratory, United States. Department of Energy. Office of Science, National Science Foundation (U.S.), National Institute of Standards and Technology (U.S.)

MiniCLEANis a single-phase noble liquid scintillator experiment designed to detect nuclear recoils due to weakly interacting massive particles hypothesized to constitute the dark matter. The principle of the detector is to monitor scintillation light resulting from ionizing radiation using 92 photomultiplier tubes surrounding a spherical target. Photomultiplier tube response is known to be affected by sub-Gauss magnetic fields, so that the Earth's magnetic field has a non-negligible effect on the photomultiplier tube efficiency. In this experiment, the crucial nuclear recoil energy threshold depends on the ability to detect very small amounts of scintillation light; high photomultiplier tube efficiency is critical. Therefore, the MiniCLEAN collaboration has designed active compensation coils to mitigate the Earth's local magnetic field. Two features of the experimental environment make this situation unique: first, the underground laboratory (SNOLAB) is located in a nickel mine, so that direct measurement of the potentially distorted geomagnetic field is mandatory. Second, the close proximity of another experiment based on photomultiplier tubes (DEAP-3600) makes the compensating field outside our detector a concern. An additional complication is that MiniCLEANis surrounded by a steel water tank needed for shielding and a muon veto composed of four strings of 12 photomultipliers suspended in the water. We describe our design based on these considerations, survey data, field calculations and simulations of the photomultiplier tube response.

How to cite this article: Valentini V., Marazzi F., Bossola M., Micciche F., Nardone L., Balducci M., Dinapoli N., Bonomo P., Autorino R., Silipigni S., Giuliani F., Tamanti C., Mele M.C. & Martorana G.E. (2012) Nutritional counselling and oral nutritional supplements in head and neck cancer patients undergoing chemoradiotherapy. J Hum Nutr Diet. 25, 201–208 Abstract Background: The role of nutritional counselling (NC) with or without oral nutritional supplements (ONS) in patients receiving chemoradiotherapy (CRT) for head and neck cancer (HNC) still remains to be clearly defined, particularly with regard to CRT-related toxicity. Methods: Patients undergoing CRT for HNC received NC by the dietitian within the first 4 days of radiotherapy and weekly for the course of radiotherapy (approximately 6 weeks). A weekly supply of oral nutrition supplements [1560 kJ (373 kcal) per 100 g] for up to 3 months was provided to all patients. Results: Twenty-one patients completed CRT. Mucositis G3 developed in seven (33.3%) patients, whereas mucositis G4 was absent. Dysphagia was present before the start of treatment in four patients. In the remaining 17 patients, dysphagia G3 developed during/at the end of treatment in five cases. The percentage of patients interrupting anti-neoplastic treatment for was 28% for ≥6 days, 28% for 3–5 days and 44% for 0–2 days. Mucositis G3 frequency was lower in patients with a baseline body mass index (BMI, kg m−2) ≥25 (two out of 12; 16.6%) than in patients with BMI 30 cm than in those with a mid arm circumference in the range 28.1–30 cm and

We present a study on the role of dislocations and impurities for the unintentional n-type conductivity in high-quality InN grown by molecular beam epitaxy. The dislocation densities and H profiles in films with free electron concentrations in the low 10 17 cm - 3 and mid 10 18 cm - 3 range are measured, and analyzed in a comparative manner. It is shown that dislocations alone could not account for the free electron behavior in the InN films. On the other hand, large concentrations of H sufficient to explain, but exceeding substantially, the observed free electron densities are found. Furthermore, enhanced concentrations of H are revealed at the film surfaces, resembling the free electron behavior with surface electron accumulation. The low-conductive film was found to contain C and it is suggested that C passivates the H donors or acts as an acceptor, producing compensated material in this case. Therefore, it is concluded that the unintentional impurities play an important role for the unintentional n-type conductivity in InN. We suggest a scenario of H incorporation in InN that may reconcile the previously reported observations for the different role of impurities and dislocations for the unintentional n-type conductivity in InN.

A method based on focused ion beam milling and analytical electron microscopy to investigate the nature of the tool-chip interface is presented. It is employed to study tool-chip interfaces of the rake face of a (Ti0.83Si0.17)N coated PCBN insert after turning of case-hardened steel. Analytical electron microscopy shows the presence of a smeared adhered layer on the coating, which consists of steel elements from the work-piece, oxygen, and Si and N, most likely originating from the coating. Original Publication:Axel Flink, R M Saoubi, Finn Giuliani, J Sjolen, T Larsson, Per Persson, M P Johansson and Lars Hultman, Microstructural characterization of the tool-chip interface enabled by focused ion beam and analytical electron microscopy, 2009, WEAR, (266), 11-12, 1237-1240.http://dx.doi.org/10.1016/j.wear.2009.03.001Copyright: Elsevier Science B.V., Amsterdam.http://www.elsevier.com/

As a result of progresses in surveillance programs and improvements in diagnosis, an increased number of hepatocellular carcinomas are diagnosed in early stage, when effective treatment options are available. Surgical resection, liver transplantation and radiofrequency ablation are considered potentially curative treatments and may be successfully applied when the disease is limited. In intermediate and advanced stages only palliative therapies can be employed and chemoembolization and the oral dual inhibitor sorafenib are considered the treatments of choice. Future directions will explore the role of sorafenib in the adjuvant setting, the addition of sorafenib to chemoembolization procedures and the combination of sorafenib with chemotherapeutic agents or other biological drugs in advanced stages of disease.

Previous acoustic instrumentation of the SIMPLE detector has relied on the use of a low-cost piezoelectric transducer, which was generally unable to provide discrimination between true bubble nucleation events and ambiental sources of acoustic noise. The use of a high-quality electret microphone and adaptive electronics is shown to provide this capacity through reduced noise levels and distinct fast Fourier transforms of the event registration.

International audience; The application of Superheated Droplet Detectors in dark matter searches by the SIMPLE project uses an acoustic instrumentation sensitive to the shock wave generated by the bubble nucleation of the refrigerant droplets. Previous instrumentation has been unable to distinguish between true nucleation and background noise events in the device, in particular microleaks associated with the escape of overpressuring nitrogen gas into the surrounding water bath. We here describe the development of an improved instrumentation which is shown to provide this discrimination capacity through a reduced noise level of the transducer amplification circuitry. (c) 2007 Elsevier B.V. All rights reserved.

Single-crystal NaCl-structure Al0.68Cr0.32N thin films were deposited onto MgO(0 0 1) substrates. The films exhibit cube-on-cube epitaxial growth with an initial pseudomorphic strained layer before ...

It is generally accepted that the hardness of silicon and germanium at low temperature is limited by a phase transformation under the indenter, as the measured hardness is equal to the transformation pressure. However, observations of the deformation under indents using transmission electron microscopy indicate that, in addition to the phase transformation, there is also plastic flow both in the transformed region and outside it. An analysis based on the spherical cavity model for indentation was developed to quantify the effect of a phase transformation on the measured hardness. This predicts that plastic deformation will extend beyond the transformed zone when the transformation pressure is greater than two-thirds of the yield stress. The analysis also predicts that the hardness can only be approximately equal to the transformation pressure if the yield strength of the transformed material is low, consistent with the experimental observations of substantial plastic deformation of the transformed phase, as well as with estimates of its lattice resistance.

Dedicated high-resolution detectors are required for detection of small cancerous breast tumours by molecular imaging with radionuclides. Absorptive collimation is normally applied in imaging single photon emitters, but it results in a strong reduction in detection efficiency. Systems based on electronic collimation are complex and expensive. For these reasons simulations and measurements have been performed to design optimised dedicated high-resolution mini gamma camera. Critical parameters are contrast and signal-to-noise ratio (SNR). Intrinsic performance (spatial resolution, pixel identification, and response linearity and uniformity) were first optimised. Pixellated scintillator arrays (NaI(Tl)) of different pixel size were coupled to arrays of PSPMTs with different anode pad dimensions (6 6m m 2 and 3 3m m 2 ). Detectors having a field of view (FOV) of 100 100 mm 2 and 150 200 mm 2 were designed and built. The electronic system allows read out of all the anode pad signals. The collimation technique was then considered and limits of coded aperture option were studied. Preliminary results are presented.

This paper reviews how layered interfaces influence the deformation behaviour of thin ceramic films. It is shown that the substantial increases in hardness of approximately 30 GPa that have been reported are not generally observed, and the ideas to explain them, based on changes in dislocation line energy, are inconsistent with these observations. Cross-sectional transmission electron microscopy of TiN/NbN multilayers with wavelengths from 2 to 25 nm shows that flow occurs by dislocation motion across the layers and by the compaction of layers if they are porous. The hardness of the multilayers is approximately 6 GPa greater than that of the monolithic films using a rule of mixtures, whilst there is no significant variation in hardness with layer thickness. It is shown that these observations are significantly closer to the predictions made using analyses based on changes to the dislocation line energy and it is tentatively suggested that the high values previously reported were associated with high internal stresses.

10th International Conference on Radiation Shielding (ICRS-10)/13th ANS Topical Meeting on Radiation Protection and Shielding (RPS 2004), Funchal, PORTUGAL, MAY 09-14, 2004; International audience; SIMPLE is a superheated droplet detector (SDD) experiment designed to search for the evidence of spin-dependent weakly interacting neutralino dark matter (WIMPs). SDDs, a type of emulsion detector, consist of a uniform suspension of superheated liquid droplets in a compliant material such as a polymeric or aqueous gel. We report on the first neutron spectrometry experiments with SIMPLE SDDs, a spin-off of the neutron detector calibrations performed at the Portuguese Research Reactor. SIMPLE SDDs differ from most SDDs available commercially as they have a 10 times higher loading factor, containing 103 times more freon than their commercial counterparts and a 100 times larger volume. We have analysed the response of SIMPLE SDDs to two quasi-monochromatic neutron beams of energies 54 and 144 keV obtained with passive filters. Results show that the characteristic peaks in the fluence distribution of both filters could be determined and their energy position obtained using a simple thermodynamic relation.

Examination of cross-sections of nanoindents with the transmission electron microscope has recently become feasible owing to the development of focused ion beam milling of site-specific electron transparent foils. Here, we discuss the development of this technique for the examination of nanoindents and survey the deformation behaviour in a range of single crystal materials with differing resistances to dislocation flow. The principal deformation modes we discuss, in addition to dislocation flow, are phase transformation (silicon and germanium), twinning (gallium arsenide and germanium at 400 °C), lattice rotations (spinel), shear (spinel), lattice rotations (copper) and lattice rotations and densification (TiN/NbN multilayers). The magnitude of the lattice rotation, about the normal to the foil, was measured at different positions under the indents. Indents in a partially recrystallized metallic glass Mg 66 Ni 20 Nd 14 were also examined. In this case a low-density porous region was formed at the indent tip and evidence of shear bands was also found. Further understanding of indentation deformation will be possible with three-dimensional characterization coupled with modelling which takes account of the variety of competing deformation mechanisms that can occur in addition to dislocation glide. Mapping the lattice rotations will be a particularly useful way to evaluate models of the deformation process.

The use of an analytical approach to determine the relation between hardness and yield strength for materials with a high ratio of yield strength to Young's modulus is re-examined. It is shown that predictions using the analogy of the spherical cavity fail to reproduce experimental and finite element results because the surface deflection that occurs during loading is not taken into account. A modification is proposed to allow this. This gives a greatly improved prediction of the relationship between the hardness and yield strength of a material. It also enables the effect of the indenter shape on the measured hardness to be incorporated and explains why in some very hard materials, indentation is observed to be completely elastic.

We report measurements of the response of large-volume superheated droplet detectors for the SIMPLE project to filtered monochromatic neutron beams of energies 54 and 149 keV. The results continue to indicate a significantly higher than anticipated response at low temperatures, but provide good support for the theoretical device calibration in temperature. A significant moderation of the incident beams by the aqueous gel of the detector and the temperature-stabilizing water bath is observed, such that the detector response is primarily governed by the superheating factor of the detector refrigerant. Translated into background neutron sensitivity of WIMP searches, these features indicate that a good choice of operating conditions is 9°C and 2 atm, with the temperature implying a mass sensitivity >5 GeV given that sufficient background reduction below this temperature can be achieved.

We report an MCNP study of filtered monochromatic neutron beams of energies 25, 54 and 149 keV for response studies of a superheated droplet detector for the SIMPLE experiment. The results identify the importance of the detector temperature stabilizing water bath and the aqueous gel of the detector on the beam quality, in general agreement with recent measurements made on the thermal port of the Portuguese research reactor.

Synchrotron-based x-ray microbeam fluorescence and diffraction have been used for in situ measurements of Cu concentration and biaxial stress in a 200-μm-long, 10-μm-wide Al(0.25 at. % Cu) conductor line with 1.5-μm-thick SiO2 passivation during electromigration. Measurements over 48 h with T=300 °C and j=1.5×105 A/cm2 show that a stress gradient of 3 MPa/μm develops over the upstream 130 μm of line length where Cu concentration drops below 0.15 at. %, and a 10-μm-long void develops at the cathode end of the line, but little change in stress occurs over the downstream 70 μm of line length where Cu concentration remains above 0.15 at. %. These experimental results have been reproduced by a finite element model in which the downstream Cu transport is accompanied by a counter flow of Al in the upstream direction, and downstream Al motion is blocked where the local Cu concentration is above ∼0.15 at. %. Defect mediated coupling between Al and Cu diffusive flows, e.g., Cu–vacancy binding, is proposed as the ca...

In a bilayer system, the decay rate of an excited quasiparticle is enhanced by momentum and energy transfer to low energy plasmonic modes. These correspond to antisymmetric charge density oscillations that propagate acoustically, with ω∼q. Within the random phase approximation, we study the relaxation rate dependence on the excitation energy above the Fermi level and suggest an experimental situation that can probe this estimate.

The aim of this work is to determine the role of different metal contacts on the performances of one-dimensional thin-film position-sensitive detectors produced by plasma-enhanced chemical vapour deposition, to be used in optical rulers for alignment applications. The device consists on an indium tin oxide/p-i-n structure where the metal contacts used were based on Al, Al + Cu and Ag. The results achieved show that the contact mainly influences the final sensor range by limiting the magnitude of the analogue signals recorded. In spite of soldering problems the Al contact was the contact that lead to better discrimination of the sensor, with a nonlinearity of ± 0.8% and a fall-off parameter of 3.2 × 103 cm−1. The Al + Cu contact also exhibits good performances (nonlinearity, of ±1.1%; fall-off parameter, 1.4 × 10−2cm−1) and should be chosen since it is much easier to solder but requires protection against oxidation. The integration of these sensors on the optical ruler lead to the production of a ...

An improved SIMPLE experiment comprising four superheated droplet detectors with a total exposure of 0.42 kg.d yields ~factor 10 improvement in the previously-reported results. Despite the low exposure, the result provides restrictions on the allowed phase space of spin-dependent coupling strengths almost equivalent to those from the significantly larger exposure NAIAD-CDMS/ZEPLIN searches.

We examine the potential impact of a WIMP search based on CF3I-loaded SDDs, projected on the basis of the experience and results of the SIMPLE dark matter search. We find such a ''heavy'' SIMPLE experiment to have spin-independent sensitivity comparable to that of leading searches like ZEPLIN-I and CDMS, while preserving the spin-dependent sensitivity of fluorine-based experiments.

It is shown that inelastic scattering suffered by tunneling electrons in the barrier of an S-I-S Josephson junction can lead to a remarkable nonmonotonic temperature dependence of the critical current of the structure. The understanding of this effect rests on the fact that under suitable conditions the inevitable loss of coherence can be more than compensated by a temperature-dependent exponential enhancement of the pair tunneling probability.

Within linear response the long range oscillations caused by short or long ranged impurities embedded in an otherwise homogeneous electron gas reflect the singularities of the static response function. By making use of the theory of the many-body local fields and the results of recent quantum Monte Carlo studies we have calculated the exact dependence of the amplitude of these oscillations on the density in a two dimensional electron Fermi liquid.

The role of nutritional counselling (NC) with or without oral nutritional supplements (ONS) in patients receiving chemoradiotherapy (CRT) for head and neck cancer (HNC) still remains to be clearly defined, particularly with regard to CRT-related toxicity.Patients undergoing CRT for HNC received NC by the dietitian within the first 4 days of radiotherapy and weekly for the course of radiotherapy (approximately 6 weeks). A weekly supply of oral nutrition supplements [1560 kJ (373 kcal) per 100 g] for up to 3 months was provided to all patients.Twenty-one patients completed CRT. Mucositis G3 developed in seven (33.3%) patients, whereas mucositis G4 was absent. Dysphagia was present before the start of treatment in four patients. In the remaining 17 patients, dysphagia G3 developed during/at the end of treatment in five cases. The percentage of patients interrupting anti-neoplastic treatment for was 28% for ≥6 days, 28% for 3-5 days and 44% for 0-2 days. Mucositis G3 frequency was lower in patients with a baseline body mass index (BMI, kg m(-2) ) ≥25 (two out of 12; 16.6%) than in patients with BMI25 (five out of nine; 55.5%) (P = 0.161) and in patients with a baseline mid arm circumference30 cm than in those with a mid arm circumference in the range 28.1-30 cm and28 cm, and higher in patients with a greater weight loss and a greater reduction of serum albumin and mid arm circumference.Nutritional counselling and ONS are associated with relatively low CRT-related toxicity and with mild deterioration of nutritional parameters.

Purpose Colon carcinoma is a malignant tumor showing a marked preference to metastasize to distant organs. The presence of circulating tumor cells (CTCs) in the peripheral blood is a prerequisite for the formation of distant metastases. However, whether circulating cytokines are linked to the circulation of tumor cells, as individual cells or clusters, remain unclear. In this study, we investigated the circulating levels of TGF-beta, CXCL1, VEGF and PAI-1 as potential bioindicators of the presence of CTCs in patients with metastatic colon cancer.

A powerful, continuous-wave millimeter radiation source is presented. An electrostatic Cockcroft-Walton accelerator (2.5 MV) drives an FEL (free-electron laser) of 1 MW power. The accelerator has a new design in order to obtain a very powerful (50 MW) electron beam and very small ripple. A recovery system is used to increase RF power and efficiency. The FEL oscillator is 1.5-m long, with a permanent magnet helical wiggler. The cavity is equipped with Bragg mirrors. The FEL is set at the high voltage terminal. >

A pulsed powerful Cockcroft-Walton generator for an electrostatic accelerator is presented. The electrostatic accelerator is designed to provide a pulsed electron beam of 5.5 MeV, 100 A, and 0.5 mu s with a repetition rate of 1 kHz. The output voltage has a descending staircase waveform. This voltage provides an electron beam made up of ten sections having different energies. Two adjacent pieces have a relative energy variation Delta gamma ij/ gamma of 1%. A dispersive system spatially separates those sections into ten 50-ns-long electron beam pulses. >

A sublimation-recondensation process is presented for high quality AlN (0001) crystals at a high growth rate by employing 4H-SiC substrates with a predeposited epilayer. It is based on the coalesce ...

Plastic behavior during loading of ferroelectric bulk materials is commonly explained by domain switching processes. In this study the authors show that dislocation induced deformation also occurs during nanoindentation of BaTiO3. Studies were conducted using a spheroconical shaped indenter together with observations using atomic force microscopy (AFM) and focussed ion beam cross sections for transmission electron microscopy (TEM) of the contact areas. Force/displacement measurements showed the sudden appearance of “pop-in” events, which AFM/TEM observations revealed were associated with plastic deformation and dislocation arrays at the surface. TEM cross sections of the indents showed paired parallel slip lines with 45° to the original surface.

we consider the current direction of searches for spin-dependent dark matter as indicated by the plethora of currently-proposed large volume search activities, indicating a possible blindside to the developments.

Spin-independent exclusion limits on WIMPs reported by various experiments assume theWIMP couples with nucleons in an isospin-independent way. Current exclusions from leading experiments are reassessed in the frame of a new WIMP-model-independent treatment which removes the above restriction. The leading spin-independent searches are shown to constrain a fully isospin-dependent WIMP interaction even though the WIMP-nucleus cross section is quenched.

The darkening and subsequent fading of silver‐halide photochromic glass upon irradiation with a Q‐switched laser pulse has been investigated. Together with new steady‐state optical measurements and ESR observations of photolytic Cu++, the data reveal three major components of the darkening at room temperature: prompt (τ

The effector arm of antibody-dependent cellular cytotoxicity (ADCC) was evaluated using 51Cr-labelled chicken erythrocytes as targets in BALB/c mice transplanted with the Moloney sarcoma virus-induced tumours T-MSV and MS2, and in C57BL/6 mice transplanted with the chemically induced FS6 sarcoma, Lewis lung carcinoma and B16 melanoma. Tumour-bearing animals showed higher levels of ADCC than normal mice, a stimulation confirmed in MS2-bearing mice, using SL2 lymphoma cells as targets in a cytostasis assay. ADCC effector-cell capacity was higher in animals transplanted with the immunogenic, spontaneously regressing T-MSV than in mice bearing the poorly immunogenic metastasizing MS2 sarcoma. The increased ADCC activity detectable in the spleen of tumour-bearing hosts was not abolished by removal of phagocytic-adherent cells.

We present the first systematic investigation by the technique of total internal optical reflection of a homologous series of low molecular weight alkanes adsorbed as hydrated films on a glass surface. The detected optical signals for these hydrated alkanes can be shown to depend empirically on the square of their molar refractivity times an optical depolarization scaling parameter. Relative scattering cross‐section measurements between a hydrated film of methane and a water film allowed for an estimate to be made of the number of water molecules which surround the methane molecule in the ‘‘cage‐like’’ hydrate structure.

Measurements of optical absorption, kinetics, electron‐spin resonance, and flash photolysis, as well as x‐ray fluorescence and wet‐chemical analysis, have been applied to a series of silver‐halide photochromic glasses having precisely controlled variations in silver and copper concentrations as well as in the size of the precipitated silver‐halide microphases. These combined experimental data have enabled us to clarify the manner in which copper enters the microphases and the mechanisms whereby it affects their photochromic properties. Most notably, we have succeeded in determining the site and valence‐state distribution of copper ions, produced by the separation of the microphases. We have demonstrated, for example, that copper enters the silver‐halide phase only as cuprous ions, which then act as the dominant hole traps in the photochromic darkening process. Optical absorption of these cuprous ions in the silver‐halide phase was also found to make a major contribution to the absorption edge observed in the undarkened photochromic glasses. The increase of thermal fade rate with increasing copper content is discussed in light of these new experimental results.

The addition of ammonium hydroxide to a weakly acidic oxazine perchlorate dye produces a color change by means of a deprotonation mechanism in which the hydroxyl radical abstracts a loosely bound proton, leaving the positively charged ammonium cation to counter balance the perchlorate anion. This reaction produces significant absorption and fluorescence band shifts which can be accounted for by a semi-classical oscillator model predicting two dichroic electronic band systems associated with this dye. Peculiar wavelength excitation dependent fluorescence band shifts are attributed to overlapping triplet states simultaneously excited.

Current‐voltage behavior of the dark current and photocurrent, photocurrent frequency response, and light spot profiles have been measured for silicon phototransistors irradiated by short pulses from a neodymium glass laser above energy densities of 10 J/cm2. The principal bulk damage effects observed were the generation of an Ohmic dark current, the formation of localized conduction paths, and the narrowing of the base layer of the device. An empirical model was used to account for these results and was shown to be consistent with previous predictions based upon the migration of phosphorus across the detector by laser‐induced melting and subsequent refreezing.