bluuebunny/crossref_metadata_2025 huggingface dataset:
Sampling considerations for intensity modulated radiotherapy verification using electronic portal imaging
Authors: Evans Philip M. , Partridge Mike , Symonds‐Tayler J. Richard N.
Published: July 2002

A model has been developed to describe the sampling process that occurs when intensity modulated radiotherapy treatments (delivered with a multileaf collimator) are imaged with an electronic portal imaging device that acquires a set of frames with a finite dead‐time between them. The effects of the imaging duty cycle and frame rate on the accuracy of dosimetric verification have been studied. A frame interval of 1 s with 25%, 50% and 75% duty cycle, and a 50% duty cycle with frame intervals of 1, 2, 4, 8, and 16 s have been studied for a smoothly varying hemispherical intensity profile, and a 50% duty cycle with frame intervals of 1, 2, 4, and 8 s for a pixellated distribution. In addition an intensity modulated beam for breast radiotherapy has been modeled and imaged for 0.33 s frame time and 1, 2, and 3 s frame separation. The results show that under sparse temporal sampling conditions, errors of the order of 10% may ensue and occur with an oscillatory pattern. For the beams studied, imaging with a 1 or 2 s frame interval resulted in small errors at the 1%–2% level, for all duty cycles shown.
Three‐dimensional dosimetric analysis and quantitative bremsstrahlung SPECT imaging for treatment of nonresectable pancreatic cancer using colloidal phosphorus‐32
Authors: Parsai E. Ishmael
Published: July 2002

A clinically applicable methodology was developed to: (1) co‐register the reconstructed three‐dimensional images from CT and SPECT, and (2) determine the 3‐D absorbed dose distribution from bremsstrahlung SPECT images for patients undergoing infusional brachytherapy using colloidal P‐32. The image co‐registration helps verify that the region of P‐32 activity distribution corresponds to the anatomic site selected for injection. For outer surfaces, the body contours obtained from bremsstrahlung SPECT data were co‐registered with corresponding contours from CT. For the administered activity, a 3‐D surface was generated by mapping the iso‐counts in the SPECT image in real coordinates. The corresponding surface objects from the CT then were matched with the SPECT using an outer surface‐fitting algorithm. The accuracy of the fit measured as the mean distance between the SPECT and CT surfaces was then calculated. Calibration curves were generated from phantom studies and activity per voxel from the attenuation corrected measured counts per voxel were determined. The cumulative activity at each voxel position was then converted to dose (Gy) using a Monte Carlo based P‐32 point dose kernel in water. Two‐ and three‐dimensional quantitative dose distributions were then generated and projected on the reconstructed SPECT or CT slices and dose‐volume histograms were analyzed.
Predicting optical densitometer response as a function of light source characteristics for radiochromic film dosimetry
Authors: Reinstein L. E. , Gluckman G. R. , Amols H. I.
Published: July 2002

Various forms of GAFChromic (GC) film have been used for several years as radiographic media for measuring dose distributions of brachytherapy sources and small radiation fields. In order to optimize the measurement sensitivity and thus improve precision, we describe a method to calculate the dose response curves (net optical density at a give wavelength or spectrum versus absorbed dose) for different densitometer light sources using measured GC film absorption spectra. Comparison with measurements on the latest version of GC film (model MD‐55‐2) using four types of densitometers [He‐Ne laser, broadband (white light) densitometer, and two LED (red‐light) filtered densitometers] confirm the accuracy of this predictive model. The linearity and sensitivity of the dose response curves are found to be highly dependent on the light source spectrum. Initial slope is a function of the average weighted absorbance. Early saturation and decreased linearity of the dose response curves are ascribed to the nonuniform transmission of the light source through the GC film. We found that an LED (red‐light) source with a narrow bandpass filter centered at 671 nm near the major absorption peak achieves nearly the maximum possible sensitivity (almost four times more sensitive than He‐Ne laser, 632.8 nm) and may be suitable for in vivo dosimetry.
Design of a dual chamber heat conduction calorimeter for ultrasonic beam measurement
Authors: See Ong Hang
Published: July 2002

This thesis describes a device that is capable of measuring ultrasonic output power quickly and accurately. The device is a dual chamber heat conduction calorimeter (HCC) designed, built, and tested for the purpose of measuring ultrasonic output power of clinical diagnostic ultrasound devices. The HCC is composed of two identical water filled aluminum wells housed in two separated compartments of an insulated box. The two compartments form the measuring and reference chambers of the calorimeter. The wells are sealed with plastic membranes that constitute the entrance window for the ultrasound. The bottom of each well is stuffed with a 4 cm layer of 0.5 cm thick rubber pads. These pads serve as a sonic‐to‐heat energy converter. In both chambers, a small resistive heater is embedded between the first and the second layer of rubber pads for calibration purposes. Heat is measured with a series of Seebeck effect thermoelectric devices (thermopiles) sandwiched between the well and the heat sink surrounding the wells. The performance and sensitivity of the HCC was measured, initially with the embedded resistive heaters, then with an experimental transducer, and lastly with transducers from clinical ultrasound scanners. The minimum detectability and the measurement uncertainty of the HCC was determined to be 1.2 mW and 6.6%, respectively.
Functional fitting of interstitial brachytherapy dosimetry data recommended by the AAPM Radiation Therapy Committee Task Group 43
Authors: Furhang Eli E. , Anderson Lowell L.
Published: July 2002

This work was undertaken to expedite implementation of the AAPM Task Group 43 recommendations, which call for significant modifications in the way dose is calculated for interstitial sources of and as well as significant changes in the dose rate constant for sources. The TG43 recommendations include a new formalism for dose calculation at points defined by the radial distance, r, from the source center and the angle, θ, that such a radius makes with the source axis. For each source type, values are tabulated for the radial dose function, the anisotropy function, and the anisotropy factor. The TG43 report includes fitting functions for the radial dose function in the form of polynomials, which are poorly behaved outside the range of fitted data. No functions are offered for the anisotropy function data or the anisotropy factor data, both of which could profit from some smoothing by such functions. We have found a double exponential fit to the radial dose function that not only approximates the data adequately but also appropriately approaches zero for very large distances. The anisotropy function is conveniently fit with a form of type which is exactly 1 at and approaches 1 for large r (for ), where is a selected polynomial in the two variables. The form chosen for the anisotropy factor was which appropriately approaches 1 for large r (and ). Functional fits of these types are expected to facilitate implementation of TG43 recommendations, in that they may be either incorporated into dose algorithms or used to generate lookup tables of either the x, y or the θ format.
The use of contrast for automated pulmonary nodule detection in low‐dose computed tomography
Authors: Narayan T. K. , Herman G. T.
Published: July 2002

A methodology for automated detection of pulmonary nodules in low‐dose computed tomography (CT) images is investigated. The methodology in question consists of (i) identifying some connected set of pixels in the CT image as a potential site for a nodule (this set of pixels is referred to as the target); (ii) specifying a further small set of pixels which are believed to be in the healthy tissue surrounding the target (this set of pixels is referred to as the background); and (iii) evaluating a function that is calculated based on the CT values in the target and in the background. The value of this function is indicative of the “noduleness” of the target; hence such a function is referred to as a detector. We present a large family of such detectors; two widely used detectors included in this family are contrast and signal‐to‐noise ratio (SNR). We show that for automated nodule detection contrast appears to be the detector of choice from this family (and, in particular, that contrast proves to be a detector superior to SNR for a variety of situations). Such claims are validated using a receiver operating characteristic (ROC) study on simulated low‐dose CT data sets (representative of thoracic cross sections with nodules) and with reconstruction algorithms appropriately optimized for the purpose of automated nodule detection.
An investigation into the applications of polymer gel dosimetry in radiotherapy
Authors: Farajollahi Ali Reza
Published: July 2002

The verification of complex dose distributions produced using novel techniques in radiotherapy requires measurements in three dimensions with high spatial resolution. Recent developments in polymer gel dosimetry employing MRI suggest this may be the best available method. In this work the properties of BANG (bis, acrylamide, nitrogen, and gelatin) polymer gel were investigated. The gel was found to be tissue equivalent and its response to absorbed dose reproducible to within ±4% and linear up to 10–12 Gy. The response of the gel was also found to be independent of energy and dose rate, but dependent on oxygen contamination and gel temperature during MR imaging. The application of BANG gel in different areas of radiotherapy was investigated. In brachytherapy a comparison of the relative dose rate distributions between gel, calculation, and TLDs agreed to within ±5%. The measured dose distributions from complex brachytherapy and multifield external beam irradiations agreed well with the distribution produced by the Helax‐TMS planning system. For external beam irradiation the depth doses measured in the gel showed good agreement with ion chamber measurements to within ±3%. The gel was also used to verify the absorbed dose distribution produced by intensity modulated beam techniques using compensators. The results agreed well with film dosimetry. BANG gel was also found to be an excellent candidate for dynamic measurements and measurements in areas with restricted access. A novel technique for measurements in boron neutron capture therapy using boron‐loaded gel is also described. It was concluded that gel can be used to verify complex dose distributions. [Copies of the thesis are available from Main Library, University of Leicester, University Road, Leicester, LE1 7RH, England.]
Source localization from axial image sets by iterative relaxation of the nearest neighbor criterion
Authors: Bice William S. , Dubois Donald F. , Prete James J. , Prestidge Bradley R.
Published: July 2002

The use of axial image sets has become widely used to localize interstitial brachytherapy sources. One application of this method of localization is to perform post‐implant dosimetry following transperineal interstitial permanent prostate brachytherapy (TIPPB) where the target structure and the source locations are displayed on the same image. The design of an appropriate scanning sequence often results in abutting slices of an intermediate slice width (3, 4, or 5 mm). Because a single source may be imaged on more than one slice, the resultant scans always show many more source locations than actual sources implanted. The physicist is then faced with the tedious task of determining which sources appear on more than one slice and deciding which source locations to eliminate from the data set. We have developed an algorithm, similar to one employed by Roy et al., which automates this process by relaxing the nearest neighbor criterion until the number of sources is reduced to either the number of sources implanted or the number counted on a projection radiograph. This paper details this algorithm and the results of its application to phantom studies, comparing to known source locations, as well as clinical studies, comparing to orthogonal film source localization, on a series of ten patients. Phantom studies demonstrate the superiority of the algorithm over orthogonal film reconstruction, locating 100% of the sources within 5 mm of the actual location as compared to 66% for the paired radiographs. The clinical study findings are commensurate with these results, with 72% of the sources on average located within 5 mm of the corresponding source in the other data set. The positive correlation of the quality of the orthogonal film reconstruction results with the quality of the coregistration results suggests that differences in registration between the two data sets may be due primarily to the uncertainties in the orthogonal film reconstruction.
Quantum information processing by nuclear magnetic resonance spectroscopy
Authors: Havel T. F. , Cory D. G. , Lloyd S. , Boulant N. , Fortunato E. M. , Pravia M. A. , Teklemariam G. , Weinstein Y. S. , Bhattacharyya A. , Hou J.
Published: July 2002

Nuclear magnetic resonance (NMR) is a direct macroscopic manifestation of the quantum mechanics of the intrinsic angular momentum of atomic nuclei. It is best known for its extraordinary range of applications, which include molecular structure determination, medical imaging, and measurements of flow and diffusion rates. Most recently, liquid-state NMR spectroscopy has been found to provide a powerful experimental tool for the development and evaluation of the coherent control techniques needed for quantum information processing. This burgeoning new interdisciplinary field has the potential to achieve cryptographic, communications, and computational feats far beyond what is possible with known classical physics. Indeed, NMR has made the demonstration of many of these feats sufficiently simple to be carried out by high school summer interns working in our laboratory (see the last two authors). In this paper the basic principles of quantum information processing by NMR spectroscopy are described, along with several illustrative experiments suitable for incorporation into the undergraduate physics curriculum. These experiments are spin–spin interferometry, an implementation of the quantum Fourier transform, and the quantum simulation of a harmonic oscillator.
Virtual probability current associated with the spin
Authors: Mita Katsunori
Published: July 2002

A simple derivation of the spin probability current density from the expectation value of the spin operator is given. The properties of the spin probability current density are then examined in detail. We show that the spin probability current is solenoidal, virtual, and gives null contribution to the momentum of the particle. Expressions of the spin probability current density are derived for the Gaussian wave packet and the s states of the hydrogen atom.
Age differences for stop-consonant and vowel perception in adults
Authors: Ohde Ralph N. , Abou-Khalil Rima
Published: July 2002

The purpose of this study was to determine the role of static, dynamic, and integrated cues for perception in three adult age groups, and to determine whether age has an effect on both consonant and vowel perception, as predicted by the “age-related deficit hypothesis.” Eight adult subjects in each of the age ranges of young (ages 20–26), middle aged (ages 52–59), and old (ages 70–76) listened to synthesized syllables composed of combinations of [b d g] and [i u a]. The synthesis parameters included manipulations of the following stimulus variables: formant transition (moving or straight), noise burst (present or absent), and voicing duration (10, 30, or 46 ms). Vowel perception was high across all conditions and there were no significant differences among age groups. Consonant identification showed a definite effect of age. Young and middle-aged adults were significantly better than older adults at identifying consonants from secondary cues only. Older adults relied on the integration of static and dynamic cues to a greater extent than younger and middle-aged listeners for identification of place of articulation of stop consonants. Duration facilitated correct stop-consonant identification in the young and middle-aged groups for the no-burst conditions, but not in the old group. These findings for the duration of stop-consonant transitions indicate reductions in processing speed with age. In general, the results did not support the age-related deficit hypothesis for adult identification of vowels and consonants from dynamic spectral cues.
Acoustical properties of irregular and fractal cavities
Authors: Sapoval B. , Haeberlé O. , Russ S.
Published: July 2002

Acoustical properties of irregular cavities described by fractal shapes are investigated numerically. Geometrical irregularity has three effects. First, the low-frequency modal density is enhanced. Second, many of the modes are found to be localized at the cavity boundary. Third, the acoustical losses, computed in a boundary layer approximation, are increased proportionally to the perimeter area of the resonator and a mathematical fractal cavity should be infinitely damped. We show that localization contributes to increase the losses. The same considerations should apply to acoustical waveguides with irregular cross section.
A simplified model for linear and nonlinear processes in thermoacoustic prime movers. Part II. Nonlinear oscillations
Authors: Yuan H. , Karpov S. , Prosperetti A.
Published: July 2002

The simplified quasi-one-dimensional model of thermoacoustic devices formulated in Part I [Watanabe et al., J. Acoust. Soc. Am. 102, 3484–3496 (1997)] is studied in the nonlinear regime. A suitable numerical method is described which is able to deal with the steep waveforms that develop in the system without inducing spurious oscillations, appreciable numerical damping, or numerical diffusion. The results are compared with some experimental ones available in the literature. Several of the observed phenomena are reproduced by the model. Quantitative agreement is also reasonable when allowance is made for likely temperature nonuniformities across the heat exchangers.
Do nasalized fricatives exist?
Authors: Ohala John J. , Sole Maria-Josep , Ying S. Goangshiuan
Published: July 2002

It has been claimed that nasalized fricatives, even sibilant fricatives, exist in some languages. To assess this claim we sought to discover how much velopharyngeal opening can be present before the acoustic and auditory characteristics of fricatives are affected. Two trained phoneticians produced steady-state voiced and voiceless strong and weak fricatives. The back pressure was intermittently bled with a tube of varying diameter (and thus impedance) inserted into the speaker’s mouth via the buccal sulcus and the gap behind the back molars, simulating nasal leakage. Intraoral pressure (Po) was sampled via a catheter inserted into the pharynx through the nose. The changes in amplitude and quality of frication were analyzed acoustically. We found that (1) a vent area of about 18 mm2 caused auditorily and acoustically noticeable lessening of fricative energy, e.g., sibilants sounded more like nonsibilants, (2) for a given vent aperture, Po was diminished less for voiceless than voiced fricatives (because the voiced fricatives have higher upstream impedance at the glottis) and consequently the same vent aperture impaired the amplitude and quality of frication of voiced fricatives more than voiceless ones. Thus the aerodynamic requirements for fricatives seem to be relatively narrow and unforgiving. [Research supported by Committee on Research, UCB, and by DGICYT, Spain, PB 96-1158.]
Determining an ocean internal wave model using acoustic log-amplitude and phase: A Rytov inverse
Authors: Ewart Terry E. , Reynolds Stephen A. , Rouseff Daniel
Published: July 2002

The feasibility of inverting acoustic field statistics to obtain the parameters of a stochastic internal wave model is demonstrated using numerical simulations. For weak scattering satisfying the Rytov approximation, the parameters of a generalized form of the Garrett–Munk internal wave model can be obtained. A hierarchy of experiment scenarios has been studied. Scenarios range from a densely populated vertical receiving array to single-point measurements. In each case, the intrinsic range-averaging of acoustic measurements provides integral constraints on the environmental model. The success of the inversion improves with increasing experimental complexity. With a vertical array, up to four parameters of the internal wave model can be recovered. For the simplest situation, two parameters can be fit with reasonable accuracy. The implications of these results for understanding oceanographic processes are discussed.
Reconstructing interior acoustic pressure fields via Helmholtz equation least-squares method
Authors: Wu Sean F. , Yu Jingyou
Published: July 2002

This paper extends the Helmholtz equation least-squares (HELS) method previously developed by Wang and Wu [J. Acoust. Soc. Am. 102, 2020–2032 (1997)] to reconstruction of acoustic pressure fields inside the cavity of a vibrating object. The acoustic pressures are reconstructed through an expansion of the acoustic modes generated by the Gram–Schmidt orthonormalization with respect to the particular solutions to the Helmholtz equation. Such an expansion is uniformly convergent because the selected acoustic modes consist of a uniformly convergent series of Legendre functions. The coefficients associated with these acoustic modes are determined by requiring the assumed-form solution to satisfy the pressure boundary condition at the measurement points. The errors incurred in this process are minimized by the least-squares method. Numerical examples of partially vibrating spheres and cylinders with various half-length to radius aspect ratios subject to different frequency excitations are demonstrated. The reconstructed acoustic pressures are compared with the analytic solutions and numerical ones obtained by using the standard boundary element method (BEM) codes.
A new bending wave solution for the classical plate equation
Authors: Kauffmann Christiaan
Published: July 2002

A new, flexural wave solution is derived for the Kirchhoff, thin plate equation on a semi-infinite domain with a free edge. This wave is a freely propagating wave that travels parallel to the edge, i.e., the curves of constant phase are straight lines perpendicular to the edge, while the wave amplitude falls off exponentially with distance from the edge, so the curves of constant amplitude are straight lines parallel to the edge. For a fixed frequency its speed is proportional to that of the standard bending wave speed. The constant of proportionality depends on the Poisson ratio only. Its value is slightly less than 1.
Nonlinear slow dynamics and memory in rocks
Authors: TenCate James A. , Smith Eric , Guyer Robert A.
Published: July 2002

Longitudinal resonance experiments on thin bars of sandstone reveal that their nonlinear behavior is richly diverse; they exhibit nonlinear mesoscopic elasticity. Resonance experiments show that, as a function of increasing drive level, resonance frequencies shift downward, curve-shape changes, and harmonics and slow dynamics appear. Slow dynamics [Geophys Res. Lett. 23, 3019–3022 (1996)] refers to the following: a large strain applied to a rock (‘‘conditioning’’) reduces its modulus (i.e., it behaves like a softer spring); if the strain is applied for several minutes, the rock will remain ‘‘soft’’ even after the strain is removed. The rock eventually recovers to its initial stiffness although the recovery may take minutes to hours. In order to explore the mechanisms of nonlinear response, including slow dynamics, experiments were performed to study the processes of conditioning and recovery. It was found that the two processes appear to be asymmetric. Conditioning takes place quickly; recovery takes place in two stages. After the conditioning strain is removed, the rock’s modulus quickly recovers to nearly the same stiffness. However, the final stage of recovery (i.e., completely back to its original state) takes minutes to hours, depending on the length of time the conditioning strain was applied.
Experimental verification of the calculated diffraction field generated by inhomogeneous waves obliquely incident on a periodically rough liquid–solid boundary
Authors: Briers R. , Leroy O. , Poncelet O. , Deschamps M.
Published: July 2002

In this paper, the diffraction of an inhomogeneous plane bulk wave at a corrugated liquid–solid boundary is considered. The classical diffraction law of Bragg for homogeneous plane waves is generalized for incident inhomogeneous bulk waves, and the obtained results are verified experimentally. The solution of the generalized diffraction law is not unique. Depending on the chosen solution, the reflection (and transmission) coefficients of the diffracted inhomogeneous waves have a different modulus and phase. An illustration is given for the zeroth-order reflection and compared with experimental results. A reflection coefficient greater than unity is observed. This effect agrees with the inhomogeneous wave theory.
On the number of channels needed to understand speech
Authors: Loizou Philipos C. , Dorman Michael , Tu Zhemin
Published: July 2002

Recent studies have shown that high levels of speech understanding could be achieved when the speech spectrum was divided into four channels and then reconstructed as a sum of four noise bands or sine waves with frequencies equal to the center frequencies of the channels. In these studies speech understanding was assessed using sentences produced by a single male talker. The aim of experiment 1 was to assess the number of channels necessary for a high level of speech understanding when sentences were produced by multiple talkers. In experiment 1, sentences produced by 135 different talkers were processed through n (2⩽n⩽16) number of channels, synthesized as a sum of n sine waves with frequencies equal to the center frequencies of the filters, and presented to normal-hearing listeners for identification. A minimum of five channels was needed to achieve a high level (90%) of speech understanding. Asymptotic performance was achieved with eight channels, at least for the speech material used in this study. The outcome of experiment 1 demonstrated that the number of channels needed to reach asymptotic performance varies as a function of the recognition task and/or need for listeners to attend to fine phonetic detail. In experiment 2, sentences were processed through 6 and 16 channels and quantized into a small number of steps. The purpose of this experiment was to investigate whether listeners use across-channel differences in amplitude to code frequency information, particularly when speech is processed through a small number of channels. For sentences processed through six channels there was a significant reduction in speech understanding when the spectral amplitudes were quantized into a small number (<8) of steps. High levels (92%) of speech understanding were maintained for sentences processed through 16 channels and quantized into only 2 steps. The findings of experiment 2 suggest an inverse relationship between the importance of spectral amplitude resolution (number of steps) and spectral resolution (number of channels).
Wave-number domain representation of tire vibration
Authors: Bolton J. Stuart , Kim Yong-joe
Published: July 2002

In the work to be described here, wave-number decomposition techniques have been used to study tire vibration. In the experimental component of this work, a tire was driven radially at a point on its treadband. Measurements of the resulting radial treadband vibration were made at approximately 200 points around the treadband circumference by using a laser Doppler velocimeter. From an inspection of the resulting space-frequency data, it was possible to identify the frequency ranges in which the tire responded either modally or nonmodally. Further, by performing a circumferential wave-number decomposition of the space-frequency data, the propagation characteristics of the wave types that contributed to the response of a tire could be determined. It was observed that a small number of circumferentially propagating waves combine to control the response of a tire in both low- and high-frequency ranges. The cut-on and propagation characteristics of these waves are closely related to propagating waveguide modes of flexural wave-bearing systems. Together, these results are consistent with a curved waveguide model of a tire. It is therefore suggested that a membrane-like waveguide model combined with a propagating wave representation of the tire vibration may offer an efficient way of representing tire vibration.
The Dynamic Shear Modulus of Paving Asphalts as a Function of Frequency
Authors: Dickinson E. J. , Witt H. P.
Published: July 2002

The deformation response of paving asphalts to small-amplitude sinusoidal loading in shear is linear and thermorheologically simple so that master curves relating the dynamic shear modulus to the (reduced) frequency can be constructed. A simple analytical expression which gives a good fit to these master curves is proposed. Data were obtained for the response of 14 different asphalts over a range of frequencies and temperatures, and master curves relating the absolute value of the modulus to the reduced frequency were constructed. These were found to fit closely to an equation which is one arm of an hyperbola whose asymptotes represent the purely viscous and purely elastic behavior expected at infinitely low and infinitely high frequencies, respectively. The rapidity with which an asphalt changes from a viscous to an elastic response as the frequency of loading increases (shear susceptibility parameter) is indicated by the distance between the point at which the hyperbola crosses its “modulus” axis and its origin. The phase angle is approximately proportional to the slope of the hyperbola, and the equation relating the phase angle with reduced frequency obtained using this relationship gave an adequate fit to the data. From this equation, and that of the hyperbola, the relaxation spectra of the materials were calculated. Shear susceptibility parameters, limiting viscosities, and moduli at a very high frequency of the materials are given and the increase of these parameters when a Kuwait asphalt was air blown in the refinery is indicated. The method used to fit the hyperbola equation to the data and an indication of the precision of fit are given in the Appendix.
X-ray powder data for MgMnSiO4 and Mg0.6Mn1.4SiO4
Authors: Yamazaki S. , Toraya H.
Published: July 2002

X-ray powder diffraction data for synthetic materials MgMnSiO4 and Mg0.6Mn1.4SiO4 are reported. Samples were prepared by firing mixtures of MgO, MnCO3, and SiO2 in prescribed molar ratios at 1523 K. Powder diffraction data were collected with a laboratory X-ray source (CuKα) for refinement of unit-cell parameters and synchrotron radiation (λ=1.1980 Å) for intensity measurement of individual reflections. Crystallographic data were MgMnSiO4, orthorhombic, Pnma (No. 62), a=10.4510(1), b=6.12446(5), c=4.80757(4) Å, V=307.717(4) Å3, Z=4, and Dx=3.697 g·cm−3, and Mg0.6Mn1.4SiO4, orthorhombic, Pnma (No. 62), a=10.5241(1), b=6.17903(6), c=4.83927(5) Å, V=314.692(5) Å3, Z=4, and Dx=3.873 g·cm−3.
SMG1, a nonsense‐mediated mRNA decay (NMD) regulator, as a candidate therapeutic target in multiple myeloma
Authors: Leeksma Alexander C. , Derks Ingrid A. M. , Garrick Brett , Jongejan Aldo , Colombo Martino , Bloedjes Timon , Trowe Torsten , Leisten Jim C. , Howarth Michelle , Malek Mehnaz , Mortensen Deborah S. , Blease Kate , Groza Mathew C. , Narla Rama Krishna , Loos Remco , Kersten Marie‐José , Moerland Perry D. , Guikema Jeroen E. J. , Kater Arnon P. , Eldering Eric , Filvaroff Ellen H.
Published: November 2022

Early data suggested that CC‐115, a clinical molecule, already known to inhibit the mammalian target of rapamycin kinase (TORK) and DNA‐dependent protein kinase (DNA‐PK) may have additional targets beyond TORK and DNA‐PK. Therefore, we aimed to identify such target(s) and investigate a potential therapeutic applicability. Functional profiling of 141 cancer cell lines revealed inhibition of kinase suppressor of morphogenesis in genitalia 1 (SMG1), a key regulator of the RNA degradation mechanism nonsense‐mediated mRNA decay (NMD), as an additional target of CC‐115. CC‐115 treatment showed a dose‐dependent increase of SMG1‐mediated NMD transcripts. A subset of cell lines, including multiple myeloma (MM) cell lines sensitive to the endoplasmic reticulum stress‐inducing compound thapsigargin, were highly susceptible to SMG1 inhibition. CC‐115 caused the induction of UPR transcripts and cell death by mitochondrial apoptosis, requiring the presence of BAX/BAK and caspase activity. Superior antitumor activity of CC‐115 over TORK inhibitors in primary human MM cells and three xenograft mouse models appeared to be via inhibition of SMG1. Our data support further development of SMG1 inhibitors as possible therapeutics in MM.
Extended disturbance observer for nonlinear system with time‐varying disturbance gain
Authors: Kim Dong‐Hyun , Choi Seibum B.
Published: November 2022

In control engineering, the disturbance is a major problem that deteriorates system robustness. To address this problem, a disturbance observer (DOB) has been proposed and developed. In particular, a general method of estimating high‐order disturbance, expressed as a time series expansion, was studied (H‐DOB). However, systems to which H‐DOB are applicable are limited to those in which disturbance gain is constant. This constraint degrades the generality of H‐DOB because applicable systems are limited. Therefore, by expanding to a system with a time‐varying disturbance gain, we propose a more general H‐DOB. The DOB proposed in this paper redesigns the dynamics of the observer based on the structure of the H‐DOB. The proposed DOB is applicable even if the system is highly nonlinear. This paper verifies the convergence of the proposed DOB through proof. Using this proof, the same characteristic error dynamics can be obtained, so the same design method can be applied. The simulation for the verification of the proposed method performs disturbance estimation of the extension system. This simulation proves that, compared to H‐DOB, the proposed DOB has good disturbance estimation performance.
Boosting B Cell and Macrophage‐Mediated Humoral Immunity with Fusion Nanovesicles for Triple‐Negative Breast Cancer Combined Therapy
Authors: Yu Yulin , Li Yang , Tian Yinmei , Hu Qian , Li Xiaonan , Tu Jingyao , Liu Han , Yang Conglian , Kong Li , Zhang Zhiping
Published: November 2022

Cell‐derived nanovesicles are widely utilized as therapeutic agents for cancer therapy. Current research mostly focuses on their ability to activate antitumor cellular immunity. However, whether they can activate and participate in antitumor humoral immunity is rarely studied. Here, doxorubicin‐loaded hybrid cell nanovesicles (DNVs) are designed for boosting antitumor humoral and cellular immunity. The hybrid cell nanovesicles are generated through fusion of nanovesicles derived from M1‐type macrophages and 4T1 tumor cells. It is found that DNVs can accumulate at tumor tissues and draining lymph nodes effectively, which results in the activation of antitumor immune response and significant inhibition of tumor progression. During this process, dendritic cells are effectively activated, subsequently inducing cytotoxicity T lymphocytes‐mediated cellular immunity. Furthermore, DNVs elicit the antitumor humoral immunity through boosting T follicular helper cells and germinal center B cells. By analyzing the mechanism behind humoral immunity activation, it is found that M1‐type macrophages repolarized by DNVs play an important role. In general, besides antitumor cellular immunity, the proposed hybrid nanovesicles provide a promising strategy for enhancing antitumor humoral immunity by macrophages repolarization and germinal center B cells activation.
Rhythm Mild‐Temperature Photothermal Therapy Enhancing Immunogenic Cell Death Response in Oral Squamous Cell Carcinoma
Authors: Ran Jianchuan , Liu Tao , Song Chuanhui , Wei Zheng , Tang Chuanchao , Cao Zichen , Zou Huihui , Zhang Xinyu , Cai Yu , Han Wei
Published: November 2022

The low antitumor efficiency and unexpected thermo‐tolerance activation of mild‐temperature photothermal therapy (mPTT) severely impede the therapeutic efficacy, thereby the implementation of reasonable mPTT procedure to improve antitumor efficiency is of great significance for clinical transformation. Herein, a rhythm mPTT with organic photothermal nanoparticles (PBDB‐T NPs) is demonstrated, synergistically increasing tumor elimination and intense immunogenic cancer cell death (ICD) to elicit tumor‐specific immune responses for tumor treatment. Specifically, PBDB‐T NPs are characterized by favorable biocompatibility, excellent and controllable photothermal properties, exhibit the properties of noninvasive diagnostic imaging, and effective mPTT against oral squamous cell carcinoma (OSCC). Encouragingly, a temperature‐dependent release of damage‐associated molecular patterns (DAMPs) is discovered during the mPTT‐induced ICD. Meanwhile, orchestrated rhythm mPTT referring to radiotherapy procedure amplifies and balances antitumor efficiency and abundant DAMPs generation to gain optimal immune activation within clinical‐recommended hyperthermia temperature compared with conventional PTT. The in vitro and in vivo results show that the rhythm mPTT unites the killing effect and ICD induction, generating strong mPTT efficacy and active tumor‐specific adaptive immune responses. The study offers a promising strategy and a new opportunity for the clinical application of mPTT.
Photolithography‐Based Microfabrication of Biodegradable Flexible and Stretchable Sensors
Authors: Bathaei Mohammad Javad , Singh Rahul , Mirzajani Hadi , Istif Emin , Akhtar Muhammad Junaid , Abbasiasl Taher , Beker Levent
Published: November 2022

Biodegradable sensors based on integrating conductive layers with polymeric materials in flexible and stretchable forms have been established. However, the lack of a generalized microfabrication method results in large‐sized, low spatial density, and low device yield compared to the silicon‐based devices manufactured via batch‐compatible microfabrication processes. Here, a batch fabrication‐compatible photolithography‐based microfabrication approach for biodegradable and highly miniaturized essential sensor components is presented on flexible and stretchable substrates. Up to 1600 devices are fabricated within a 1 cm2 footprint and then the functionality of various biodegradable passive electrical components, mechanical sensors, and chemical sensors is demonstrated on flexible and stretchable substrates. The results are highly repeatable and consistent, proving the proposed method's high device yield and high‐density potential. This simple, innovative, and robust fabrication recipe allows complete freedom over the applicability of various biodegradable materials with different properties toward the unique application of interests. The process offers a route to utilize standard micro‐fabrication procedures toward scalable fabrication of highly miniaturized flexible and stretchable transient sensors and electronics.
Radiative Recombination Processes in Halide Perovskites Observed by Light Emission Voltage Modulated Spectroscopy
Authors: Sánchez Rafael S. , Villanueva‐Antolí Alexis , Bou Agustín , Ruiz‐Murillo Marta , Mora‐Seró Iván , Bisquert Juan
Published: November 2022

The kinetics of light emission in halide perovskite light‐emitting diodes (LEDs) and solar cells is composed of a radiative recombination of voltage‐injected carriers mediated by additional steps such as carrier trapping, redistribution of injected carriers, and photon recycling that affect the observed luminescence decays. These processes are investigated in high‐performance halide perovskite LEDs, with external quantum efficiency (EQE) and luminance values higher than 20% and 80 000 Cd m−2, by measuring the frequency‐resolved emitted light with respect to modulated voltage through a new methodology termed light emission voltage modulated spectroscopy (LEVS). The spectra are shown to provide detailed information on at least three different characteristic times. Essentially, new information is obtained with respect to the electrical method of impedance spectroscopy (IS), and overall, LEVS shows promise to capture internal kinetics that are difficult to be discerned by other techniques.
MoS2‐Mediated Epitaxial Plating of Zn Metal Anodes
Authors: Wang Yizhou , Xu Xiangming , Yin Jian , Huang Gang , Guo Tianchao , Tian Zhengnan , Alsaadi Rajeh , Zhu Yunpei , Alshareef Husam N.
Published: November 2022

Metal‐based anodes (Li, Zn, etc.) are regarded as promising solutions for next‐generation advanced batteries due to their high theoretical specific capacities. However, most of these metal anodes suffer from dendrite growth, which severely restricts their practical applications. Recently, epitaxial anode metal deposition by choosing a suitable substrate has received tremendous attention as an effective strategy to suppress dendrites. However, the epitaxial relationship between plated metal and the substrate has been a subject of debate. Herein, large‐area, mono‐orientated 2D material (MoS2) is used, for the first time, to electrodeposit truly epitaxial Zn anodes. The continuous (without edges) mono‐orientated MoS2 films are shown to be an effective strategy for suppressing metal dendrites. In addition, the epitaxial nature of the electrodeposited Zn anode is proven by pole figure analysis, which provides the first demonstration of truly epitaxial Zn anode growth over large area as metal anode protection strategy through epitaxy.
Piezoelectric 1T Phase MoSe2 Nanoflowers and Crystallographically Textured Electrodes for Enhanced Low‐Temperature Zinc‐Ion Storage
Authors: Li Yihui , Dong Xingfang , Xu Zewen , Wang Menglei , Wang Ruofei , Xie Juan , Ding Yangjian , Su Pengcheng , Jiang Chengying , Zhang Xingmin , Wei Liyu , Li Jing‐Feng , Chu Zhaoqiang , Sun Jingyu , Huang Cheng
Published: November 2022

Transition metal dichalcogenides (TMDs) are regarded as promising cathode materials for zinc‐ion storage owing to their large interlayer spacings. However, their capabilities are still limited by sluggish kinetics and inferior conductivities. In this study, a facile one‐pot solvothermal method is exploited to vertically plant piezoelectric 1T MoSe2 nanoflowers on carbon cloth (CC) to fabricate crystallographically textured electrodes. The self‐built‐in electric field owing to the intrinsic piezoelectricity during the intercalation/deintercalation processes can serve as an additional piezo‐electrochemical coupling accelerator to enhance the migration of Zn2+. Moreover, the expanded interlayer distance (9–10 Å), overall high hydrophilicity, and conductivity of the 1T phase MoSe2 also promoted the kinetics. These advantages endow the tailored 1T MoSe2/CC nanopiezocomposite with feasible Zn2+ diffusion and desirable electrochemical performances at room and low temperatures. Moreover, 1T MoSe2/CC‐based quasi‐solid‐state zinc‐ion batteries are constructed to evaluate the potential of the proposed material in low‐temperature flexible energy storage devices. This work expounds the positive effect of intrinsic piezoelectricity of TMDs on Zn2+ migration and further explores the availabilities of TMDs in low‐temperature wearable energy‐storage devices.
Bio‐Inspired Synthetic Hydrogen‐Bonded Organic Frameworks for Efficient Proton Conduction
Authors: Sun Yayong , Wei Jing , Fu Zhihua , Zhang Minyi , Zhao Sangen , Xu Gang , Li Chunsen , Zhang Jian , Zhou Tianhua
Published: November 2022

Hydrogen‐bonded organic frameworks (HOFs) are a rising class of promising proton‐conducting materials. However, they always suffer from the inherent contradiction between chemical stability and proton conduction. Herein, inspired by the self‐assembly of lipid bilayer membranes, a series of aminomethylphosphonic acid‐derived single‐component HOFs are successfully developed with different substituents attached to the phosphonate oxygen group. They remain highly stable in strong acid or alkaline water solutions for one month owing to the presence of charge‐assisted hydrogen bonds. Interestingly, in the absence of external proton carriers, the methyl‐substituted phosphonate‐based HOF exhibits a very high proton conductivity of up to 4.2 × 10−3 S cm−1under 80 °C and 98% relative humidity. This value is not only comparable to that of HOFs consisting of mixed ligands but also is the highest reported in single‐component HOFs. A combination of single‐crystal structure analysis and density functional theory calculations reveals that the high conductivity is attributed to the strengthened H‐bonding interactions between positively charged amines and negatively charged phosphonate groups in the channel of bio‐inspired HOFs. This finding demonstrates that the well‐defined molecular structure of proton conductors is of great importance in the precise understanding of the relationship between structure and property.
BSA‐AIE Nanoparticles with Boosted ROS Generation for Immunogenic Cell Death Immunotherapy of Multiple Myeloma
Authors: Liu Zhaoyun , Zhang Jingtian , Liu Hui , Shen Hongli , Meng Nanhao , Qi Xinwen , Ding Kai , Song Jia , Fu Rong , Ding Dan , Feng Guangxue
Published: November 2022

The main obstacle of multiple myeloma (MM) therapy is the compromised immune microenvironment, which leads to MM relapses and extramedullary disease progression. In this study, a novel strategy is reported of enhanced immunogenic cell death (ICD) immunotherapy with aggregation‐induced emission (AIE) photosensitizer‐loaded bovine serum albumin (BSA) nanoparticles (referred as BSA/TPA‐Erdn), which can activate T cells, convert the cold tumor to hot, and reverse T cell senescence to restore the immune microenvironment for MM treatment. Loading AIE photosensitizer into the hydrophobic domain of BSA proteins significantly immobilizes the molecular geometry, which massively increases reactive oxygen species (ROS) generation and elicits a promising ICD immune response. Employing a NOD‐SCID IL‐2receptor gamma null mice model with MM patients’ monocytes, it is shown that BSA/TPA‐Erdn can simulate human dentric cell maturation, activate functional T lymphocytes, and increase additional polarization and differentiation signals to deliver a promising immunotherapy performance. Intriguingly, for the first time, it is shown that BSA/TPA‐Erdn can greatly reverse T cell senescence, a main challenge in treating MM. Additionally, BSA/TPA‐Erdn can effectively recruit more functional T lymphocytes into MM tumor. As a consequence, BSA/TPA‐Erdn restores MM immune microenvironment and shows the best MM tumor eradication performance, which shall pave new insights for MM treatment in clinical practices.