bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement‐based Monte Carlo dose calculation system for IMRT pretreatment and on‐line transit dose verifications
Authors: Lin Mu‐Han , Chao Tsi‐Chian , Lee Chung‐Chi , Tung Chuan‐Jong , Yeh Chie‐Yi , Hong Ji‐Hong
Published: March 2009

The aim of this study was to develop a dose simulation system based on portal dosimetry measurements and the BEAM Monte Carlo code for intensity‐modulated (IM) radiotherapy dose verification. This measurement‐based Monte Carlo (MBMC) system can perform, within one systematic calculation, both pretreatment and on‐line transit dose verifications. BEAMnrc and DOSXYZnrc 2006 were used to simulate radiation transport from the treatment head, through the patient, to the plane of the aS500 electronic portal imaging device (EPID). In order to represent the nonuniform fluence distribution of an IM field within the MBMC simulation, an EPID‐measured efficiency map was used to redistribute particle weightings of the simulated phase space distribution of an open field at a plane above a patient/phantom. This efficiency map was obtained by dividing the measured energy fluence distribution of an IM field to that of an open field at the EPID plane. The simulated dose distribution at the midplane of a homogeneous polystyrene phantom was compared to the corresponding distribution obtained from the Eclipse treatment planning system (TPS) for pretreatment verification. It also generated a simulated transit dose distribution to serve as the on‐line verification reference for comparison to that measured by the EPID. Two head‐and‐neck (NPC1 and NPC2) and one prostate cancer fields were tested in this study. To validate the accuracy of the MBMC system, film dosimetry was performed and served as the dosimetry reference. Excellent agreement between the film dosimetry and the MBMC simulation was obtained for pretreatment verification. For all three cases tested, gamma evaluation with 3%/3 mm criteria showed a high pass percentage within the area in which the dose was greater than 30% of the maximum dose. In contrast to the TPS, the MBMC system was able to preserve multileaf collimator delivery effects such as the tongue‐and‐groove effect and interleaf leakage. In the NPC1 field, the TPS showed 16.5% overdose due to the tongue‐and‐groove effect and 14.6% overdose due to improper leaf stepping. Similarly, in the NPC2 field, the TPS showed 14.1% overdose due to the tongue‐and‐groove effect and 8.9% overdose due to improper leaf stepping. In the prostate cancer field, the TPS showed 6.8% overdose due to improper leaf stepping. No tongue‐and‐groove effect was observed for this field. For transit dose verification, agreements among the EPID measurement, the film dosimetry, and the MBMC system were also excellent with a minimum gamma pass percentage of 99.6%.
Evaluation of the dose distribution for prostate implants using various and sources
Authors: Meigooni Ali S. , Luerman Christine M. , Sowards Keith T.
Published: March 2009

Recently, several different models of and brachytherapy sources have been introduced in order to meet the increasing demand for prostate seed implants. These sources have different internal structures; hence, their TG‐43 dosimetric parameters are not the same. In this study, the effects of the dosimetric differences among the sources on their clinical applications were evaluated. The quantitative and qualitative evaluations were performed by comparisons of dose distributions and dose volume histograms of prostate implants calculated for various designs of and sources. These comparisons were made for an identical implant scheme with the same number of seeds for each source. The results were compared with the Amersham model 6711 seed for and the Theragenics model 200 seed for using the same implant scheme.
Characterization of a mammographic system based on single photon counting pixel arrays coupled to GaAs x‐ray detectors
Authors: Amendolia S. R. , Bisogni M. G. , Delogu P. , Fantacci M. E. , Paternoster G. , Rosso V. , Stefanini A.
Published: March 2009

The authors report on the imaging capabilities of a mammographic system demonstrator based on GaAs pixel detectors operating in single photon counting (SPC) mode. The system imaging performances have been assessed by means of the transfer functions: The modulation transfer function (MTF), the normalized noise power spectrum, and the detective quantum efficiency (DQE) have been measured following the guidelines of the IEC 62220–1‐2 protocol. The transfer function analysis has shown the high spatial resolution capabilities of the GaAs detectors. The MTF calculated at the Nyquist frequency (2.94 cycles/mm) is indeed 60%. The DQE, measured with a standard mammographic beam setup (Mo/Mo, 28 kVp, with 4 mm Al added filter) and calculated at zero frequency, is 46%. Aiming to further improve the system's image quality, the authors investigate the DQE limiting factors and show that they are mainly related to system engineering. For example, the authors show that optimization of the image equalization procedure increases the DQE(0) up to 74%, which is better than the DQE(0) of most clinical mammographic systems. The authors show how the high detection efficiency of GaAs detectors and the noise discrimination associated with the SPC technology allow optimizing the image quality in mammography. In conclusion, the authors propose technological solutions to exploit to the utmost the potentiality of GaAs detectors coupled to SPC electronics.
Principles and Advanced Methods in Medical Imaging and Image Analysis
Authors: Ritenour E. Russell
Published: March 2009

Principles and Advanced Methods in Medical Imaging and Image Analysis Dhawan Atam P., Huang H. K. and Kim Dae‐Shik World Scientific, Hackensack, NJ, 2008. Hardcover 868 pp. Price: $228.00. ISBN: 978‐981‐270‐534‐1.
Advances in Medical Physics: 2008
Authors: Robinson Donald
Published: March 2009

Advances in Medical Physics: 2008 Wolbarst Anthony B., Mossman Kenneth L. and Hendee William R. Medical Physics Publishing, Madison, WI, 2008. Hardcover 368 pp. Price: $94.00. ISBN: 9781930524385.
Screening eucalypts for frost tolerance in breeding programs
Authors: Raymond C.A. , Owen J.V. , Eldridge K.G. , Harwood C.E.
Published: March 2009

Improvements in a laboratory technique and statistical methods for screening eucalypts for relative frost tolerance using small samples of leaf tissue are described. As a contribution to more efficient genetic selection in a breeding program, these methods aim to provide reliable estimates of relative frost tolerance for ranking genotypes and to allow partitioning of total variation into components due to provenances, families, and individuals. Examination of sampling strategies indicated that four leaf discs per seedling at three frosting temperatures and 10 seedlings per family provided highly reliable estimates of frost tolerance. Mean relative conductivity values were found to be highly correlated with mean leaf damage sustained by a seedling across the whole range of values. Alternative methods of data analysis are compared. Estimation of LD50 values (the temperature at which 50% of leaf discs would be killed) and calculation of percent survival of leaf discs were found to be less efficient means of data analysis than directly analysing relative conductivity values. The nature of genetic control of frost tolerance and the assumptions underlying such nondestructive screening techniques are examined.
QUANTUM DYNAMICS OF DOUBLE QUBIT IN A SPIN STAR LATTICE WITH AN x–y INTERACTION
Authors: JING JUN , LÜ ZHIGUO , MA HONG-RU
Published: March 2009

The dynamics of two spins-1/2 interacting with a spin-bath via the quantum Heisenberg x–y coupling is studied. The purity, z-component summation and the concurrence of the central subsystem are determined by the Laguerre polynomial scheme. It is found that (i) at a low temperature, the uncoupled subsystem in a product state can be entangled by the bath, which is tested by the Peres–Horodecki separability; (ii) the resistance of the subsystem in Bell states to the destroy effect from the bath increases with its inner-coupling strength.
Lichtwahrnehmung und Pfingstauffassung im Frühmittelalter
Authors: Kleinschmidt Harald
Published: March 2009

The early medieval exegesis of the Pentecost account in the Acts of the Apostles emphasised the divine origin of the light that some early medieval theologists, specifically Hrabanus Maurus, believed to have descended upon the Apostles (or the congregation) and provided them with special powers. The following article links Hrabanus Maurus's exegetical work with early pictorial representations of Pentecost as well as medieval theories of action.
Implementation and Analysis of Networked Radar Refractivity Retrieval
Authors: Fritz Jason , Chandrasekar V.
Published: March 2009

The surface-layer moisture field can be obtained by estimating the refractive index of air, measured in parts per million, and is referred to as refractivity. A technique to estimate the refractivity by using radar has been demonstrated experimentally using the measured change in phase from stationary ground targets. Recently, a new network-based algorithm was proposed within the Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) as an alternative approach, especially when dealing with multiple radars. That work presented the algorithm and applied it to purely simulated data. The research presented here provides more detail and takes the new networked radar approach to the next level by independently validating and demonstrating the output with data collected during a refractivity field experiment in Colorado during the summer of 2006. The practical aspects of implementing the network-based algorithm are presented along with a more complete mathematical representation. The results are then compared with the previously fielded technique starting from the same filtered phase data. From this comparison, the authors conclude that the networked algorithm has potential for providing a good refractivity estimate from a radar network once some of its own shortcomings are addressed.
Transient in utero disruption of Cystic Fibrosis Transmembrane Conductance Regulator causes phenotypic changes in Alveolar Type II cells in adult rats
Authors: Gad Ashraf , Callender Delon L , Killeen Erin , Hudak Joseph , Dlugosz Malgosia A , Larson Janet E , Cohen J Craig , Chander Avinash
Published: March 2009

Background

Mechanicosensory mechanisms regulate cell differentiation during lung organogenesis. We have previously demonstrated that cystic fibrosis transmembrane conductance regulator (CFTR) was integral to stretch-induced growth and development and that transient expression of antisense-CFTR (ASCFTR) had negative effects on lung structure and function. In this study, we examined adult alveolar type II (ATII) cell phenotype after transient knock down of CFTR by adenovirus-directed in utero expression of ASCFTR in the fetal lung.

Results

In comparison to (reporter gene-treated) Controls, ASCFTR-treated adult rat lungs showed elevated phosphatidylcholine (PC) levels in the large but not in the small aggregates of alveolar surfactant. The lung mRNA levels for SP-A and SP-B were lower in the ASCFTR rats. The basal PC secretion in ATII cells was similar in the two groups. However, compared to Control ATII cells, the cells in ASCFTR group showed higher PC secretion with ATP or phorbol myristate acetate. The cell PC pool was also larger in the ASCFTR group. Thus, the increased surfactant secretion in ATII cells could cause higher PC levels in large aggregates of surfactant. In freshly isolated ATII cells, the expression of surfactant proteins was unchanged, suggesting that the lungs of ASCFTR rats contained fewer ATII cells. Gene array analysis of RNA of freshly isolated ATII cells from these lungs showed altered expression of several genes including elevated expression of two calcium-related genes, Ca2+-ATPase and calcium-calmodulin kinase kinase1 (CaMkk1), which was confirmed by real-time PCR. Western blot analysis showed increased expression of calmodulin kinase I, which is activated following phosphorylation by CaMkk1. Although increased expression of calcium regulating genes would argue in favor of Ca2+-dependent mechanisms increasing surfactant secretion, we cannot exclude contribution of alternate mechanisms because of other phenotypic changes in ATII cells of the ASCFTR group.

Conclusion

Developmental changes due to transient disruption of CFTR in fetal lung reflect in altered ATII cell phenotype in the adult life.
Physical Performance Limitations in the Childhood Cancer Survivor Study Cohort
Authors: Ness Kirsten K. , Hudson Melissa M. , Ginsberg Jill P. , Nagarajan Rajaram , Kaste Sue C. , Marina Neyssa , Whitton John , Robison Leslie L. , Gurney James G.
Published: March 2009

Physical performance limitations are one of the potential long-term consequences following diagnosis and treatment for childhood cancer. The purpose of this review is to describe the risk factors for and the participation restrictions that result from physical performance limitations among childhood cancer survivors who participated in the Childhood Cancer Survivor Study (CCSS). Articles previously published from the CCSS cohort related to physical performance limitations were reviewed and the results summarized. Our review showed that physical performance limitations are prevalent among childhood cancer survivors and may increase as they age. Host-based risk factors for physical disability include an original diagnosis of bone tumor, brain tumor, or Hodgkin's disease; female sex; and an income less than $20,000 per year. Treatment-based risk factors include radiation and treatment with a combination of alkylating agents and anthracyclines. Musculoskeletal, neurologic, cardiac, pulmonary, sensory, and endocrine organ system dysfunction also increase the risk of developing a physical performance limitation. In summary, monitoring of physical performance limitations in an aging cohort of childhood cancer survivors is important and will help determine the impact of physical performance limitations on morbidity, mortality, and caregiver burden. In addition, in developing restorative and preventive interventions for childhood cancer survivors, we must take into account the special needs of survivors with physical disability to optimize their health and enhance participation in daily living activities.
Globalization and the Welfare State: A Review of Hans-Werner Sinn'sCan Germany Be Saved?
Authors: Snower Dennis J , Brown Alessio J. G , Merkl Christian
Published: March 2009

What are the challenges that globalization makes on welfare states and how should welfare states respond? How should welfare states be designed to enable countries to reap the benefits of globalization? These are the main themes of Hans-Werner Sinn's book, Can Germany Be Saved? We view Germany as a case study of how a welfare state can go wrong in reacting to the pressures of globalization. We present two views of globalization—the “specialization view” (of Sinn) and the “Great Reorganization view” (ours)—and examine the policy implications of each for the welfare state design.
Charnley low-frictional torque arthroplasty
Authors: Wroblewski B. M. , Siney P. D. , Fleming P. A.
Published: March 2009

Of the 11 054 Charnley low-frictional torque arthroplasties carried out at our hospital between 1962 and 1977, 110 (94 patients) had a minimum follow-up of 30 years with a mean of 32.3 years (30.0 to 40.5). The mean age of the patients at operation was 43.3 years (17.0 to 65.0) and 75.7 years (51.0 to 97.0) at follow-up. Overall, 90% of hips (99) were free from pain and activity was reported as normal in 58% of the patients.

A total of 13 hips (11.8%) were revised at a mean follow-up of 32.3 years (30.0 to 39.5), with wear and loosening of the acetabular component as the main indications.

The clinical results did not reflect the mechanical state of the implant. Follow-up with sequential radiographs of good quality is essential. Revision for radiological changes alone must be accepted if gross loss of bone stock is to be avoided.

Improvements in the design, materials and operative technique, based on the long-term outcome, are highlighted.
Ecotoxicological Assessment of an In-Lake Remediation Method
Authors: Soumis-Dugas Gabriel , Triffaut-Bouchet Gaëlle , Galvez Rosa , Martel Louis
Published: March 2009

Eutrophication and contaminated sediments are preoccupying issues in aquatic ecosystems and water resources protection. Saint-Augustin Lake (Quebec, Canada) is affected by both problems (eutrophication and contaminated sediment) and the presence of de-icing salts. According to sustainable management principles, Galvez and collaborators are developing an in-lake remediation method to restore eutrophicated lakes which consists of (a) the precipitation of the phosphorus present in the water column by the addition of alum in association with (b) the deposit of an active capping layer (calcite+sand) to isolate P, Al, and the contaminated sediments. The objective of this study is to assess the ecotoxicological impact of this restoration method for the Saint-Augustin Lake. Two ecotoxicological approaches will be used to assess this impact: (a) single-species bioassays using algal (Pseudokirchneriella subcapitata; growth), duckweed (Lemna minor; growth), daphnid (Daphnia magna; survival and reproduction), amphipod (Hyalella azteca; survival and reproduction), and invertebrate (Chironomus riparius; survival, growth, and emergence); and (b) a 2-L microcosm assay using the same organisms for purpose of comparisons. Alum toxicity, calcite impact, and organisms’ recolonization ability will be studied separately: first in artificial conditions, by using formulated sediments and artificial water and by considering de-icing salts impact, and secondly by using the sediments and overlying water of the Saint-Augustin lake. Preliminary results are available and presented here. No effect was measured for salt (NaCl) toxicity on algae, daphnids, chironomids, and amphipods. Alum inhibited algal growth strongly, had no impact on D. magna mobility and survival, but a clear dose-effect response was observed for daphnid reproduction. The global remediation method had almost the same effect as alum on P. subcapitata but stimulated daphnid reproduction at 10 mg/L alum, while it was reduced with 20 mg/L, and completely inhibited with 30 mg/L.
Chapter 12-Bone Graft Substitutes: A Regulatory Perspective
Authors: Attawia M , Rosier R , Gadaleta SJ
Published: March 2009

FOR MORE THAN 30 YEARS, the orthopedic community, including academic, industrial, and government sectors, has been investigating the use of synthetic-, growth factor-, and cell-based therapies as bone graft substitutes; the ultimate goal of which is to reduce or eliminate the use of autograft in healing bony defects. Synthetic bone graft substitutes, demineralized bone matrix, and bone morphogenetic proteins are legally marketed bone graft substitutes; however, each of these products has a distinct regulatory classification and, as such, requires a different regulatory path for approval prior to marketing.
Chapter 15-The Development of Coralline Porous Ceramic Graft Substitutes
Authors: Agrawal M , Katti DS , Shors EC
Published: March 2009

BONE, UNLIKE MOST TISSUES, HAS a unique ability to regenerate, reforming completely without a scar. Surgeons have learned over the centuries to capitalize on this natural and invaluable attribute for the repair of large defects or to generate bone where it does not normally form. Autograft is the undisputed “gold standard” today for generating or regenerating bone. Over 250,000 autograft procedures are performed annually for orthopedic and neurosurgical treatments in the United States alone. However, autografting is not without disadvantages. Clinical studies show that it causes increased donor site morbidity to the patient, such as pain, blood loss, and scarring [1]. In addition, harvesting bone adds additional operating room time to the procedure. Further, the volume or quantity of autograft may be limited. Therefore, other bone grafting materials have been developed.
Segmental Duplications Contribute to Gene Expression Differences Between Humans and Chimpanzees
Authors: Blekhman Ran , Oshlack Alicia , Gilad Yoav
Published: March 2009

In addition to specific changes in cis- and trans-regulatory elements, structural changes in the genome are hypothesized to underlie a large number of differences in gene expression between species. Accordingly, we show that species-specific segmental duplications are enriched with genes that are differentially expressed between humans and chimpanzees.
Remission in Rheumatoid Arthritis: Physician and Patient Perspectives
Authors: WOLFE FREDERICK , BOERS MAARTEN , FELSON DAVID , MICHAUD KALEB , WELLS GEORGE A.
Published: March 2009

Objective.

To examine the prevalence of remission in rheumatoid arthritis (RA) as determined by physicians and patients independently, and to determine the degree of agreement among methods, the strength of predictor variables of remission, and the length of remission.

Methods.

Eight hundred patients with RA completed a remission questionnaire on the day of their rheumatologist visit and their rheumatologists completed a separate questionnaire the same day. The question(s) were: “Given all your experience with disease activity in RA, are you [is your patient] currently in remission?”. Patients also completed 0–10 visual analog scales for RA activity, pain, and functional limitation.

Results.

The percentage of patients in remission by physician and patient assessment was 34.8% [95% confidence interval (CI) 31.4–38.2] and 30.9% (95% CI 27.7–34.20), respectively. The percentage of patients classified concordantly (full agreement) was 78.6%, and the associated kappa statistic was 0.54 (95% CI 0.45–0.58). The median duration of remission was 2.0 years. The median RA activity, pain, and functional scores were 1.0, 1.5, and 1.25 for patient-determined remission and 1.5, 1.5, and 1.5 for physician-determined remission.

Conclusion.

Physician and patient estimates of remission in RA are similar (34.8% to 30.9%), and agreement was 78.6% (kappa 0.53). Based on previous data and the observed presence of disease activity, this definition of remission appears to be a measure of minimal disease activity rather than true remission. The problem of remission rates will not be solved until a consensus definition that has relevance in research and the clinic is developed.
L'alcool donne-t-il un genre ?
Authors: Beck François , Legleye Stéphane , De Peretti Gaël
Published: March 2009

Résumé L’étude des comportements de consommation d’alcool et de leur perception par la société est une approche intéressante de la notion de genre, en particulier en France où cette consommation est fortement intégrée aux relations sociales (repas de famille ou entre amis, célébrations en tout genre, etc.) et donc a priori moins stigmatisée que dans certains autres pays. En nous appuyant sur les travaux de Sidsel Eriksen (1999) qui définit l’alcool comme un « symbole » du genre et une exploitation statistique de nombreuses sources récentes (Baromètre santé 2000, Eropp2002), nous montrons que la dichotomieentre genre et perception par la société de la consommation d’alcool qui s’affirme au xix e siècle se prolonge aujourd’hui. En particulier, bien que la consommation d’alcool reste faible chez les femmes et très inférieure à celle des hommes, le spectre de l’explosion de cette consommation est régulièrement agité comme une réelle menace pour la société.
De la migration au travail
Authors: Yun Gao , Lévy Florence , Poisson Véronique
Published: March 2009

Résumé La vulnérabilité est au cœur des parcours migratoires des Chinois vers la France. Elle commence lors du trajet et se poursuit bien après leur arrivée. Leur voyage se déroule souvent sur plusieurs mois dans des conditions inhumaines. L’arrivée en France ne marque pas la fin du calvaire, bien au contraire. Ils se retrouvent en situation irrégulière et pris en tenaille entre l’impossibilité d’obtenir une autorisation de travail et la nécessité de rembourser leurs dettes au plus vite. L’économie souterraine, grande pourvoyeuse d’emplois illégaux, et en particulier l’économie ethnique apparaît comme la seule issue possible. Une issue qui prend la forme d’une exploitation extrême par le travail. Cet article met en lumière ce type d’exploitation mis en œuvre par des employeurs souvent issus de la communauté chinoise et à ce titre les mieux placés pour abuser de la vulnérabilité des nouveaux migrants.
Preoperative GLP-1 Receptor Agonist Use and Risk of Postoperative Respiratory Complications
Authors: Dixit Anjali A. , Bateman Brian T. , Hawn Mary T. , Odden Michelle C. , Sun Eric C.
Published: April 2024

This cohort study evaluates the risk of postoperative respiratory complications among patients with diabetes undergoing surgery who had vs those who had not a prescription fill for glucagon-like peptide 1 receptor agonists.
Biological Poverty Line for Infants—Evidence and Implications
Authors: Luby Joan L. , Rank Mark R. , Barch Deanna M.
Published: April 2024

This Viewpoint discusses whether protective and promotive interventions in brain development would benefit from identification of a “biological poverty line” during pregnancy and early childhood, above which the brain is informed and enhanced by experience in positive ways, and below which adverse experiences may influence the brain in ways that do not support long-term health trajectories.
Pathologically based criteria to distinguish essential tremor from controls: analyses of the human cerebellum
Authors: Faust Phyllis L. , McCreary Morgan , Musacchio Jessica B. , Kuo Sheng‐Han , Vonsattel Jean‐Paul G. , Louis Elan D.
Published: April 2024

Objective

Essential tremor is among the most prevalent neurological diseases. Diagnosis is based entirely on neurological evaluation. Historically, there were few postmortem brain studies, hindering attempts to develop pathologically based criteria to distinguish essential tremor from control brains. However, an intensive effort to bank essential tremor brains over recent years has resulted in postmortem studies involving >200 brains, which have identified numerous degenerative changes in the essential tremor cerebellar cortex. Although essential tremor and controls have been compared with respect to individual metrics of pathology, there has been no overarching analysis to derive a combination of metrics to distinguish essential tremor from controls. We asked whether there is a constellation of pathological findings that separates essential tremor from controls, and how well that constellation performs.

Methods

Analyses included 100 essential tremor brains from the essential tremor centralized brain repository and 50 control brains. A standard tissue block from the cerebellar cortex was used to quantify 11 metrics of pathological change. Three supervised classification algorithms were investigated, with data divided into training and validation samples.

Results

Using three different algorithms, we illustrate the ability to correctly predict a diagnosis of essential tremor, with sensitivity and specificity >87%, and in the majority of situations, >90%. We also provide a web‐based application that uses these metric values, and based on specified cutoffs, determines the likely diagnosis.

Interpretation

These analyses set the stage for use of pathologically based criteria to distinguish clinically diagnosed essential tremor cases from controls, at the time of postmortem.
Development of Fe‐10% (HA/β‐Tricalcium Phosphate) Composite via Solid‐State Manufacturing Route and Investigation of Material Properties for Biodegradable Implant Applications
Authors: Gunay Bulutsuz Asli , Chrominski Witold , Bazarnik Piotr , Bruder Enrico
Published: April 2024

Day‐by‐day biodegradable alloys and composites are getting more attention. Besides their competing material properties with traditional permanent implants, their harmless degradation in the body eliminates the need for a second surgery to remove the implant. Beyond other biodegradable materials such as Mg and Zn, Fe is known with high strength with low degradation rate. However there is still need to improve its biocompatibility. Herein, a Fe‐based composite is developed via solid‐state manufacturing route. 10% HA/β‐TCP is selected as an additive which is a biocompatible ceramic material and the powder mix is ball‐milled. Afterward, the powders are consolidated via high‐pressure torsion (HPT) with 1–5–10 revolutions at room temperature. Crack‐free structures are obtained even after 1 HTP rotation. Fe is in lamellar form around HA‐βTCP particles. With the increase of HPT rotation numbers, lath thickness decreased. After 10 HPT rotations, 24% enhancement in density is observed that points to a more condensed structure. Transmission electron microscopy observations show significant grain refinement after 1 HPT rotation, and Fe grain size remains constant (≈300 nm) up to 10 turns. Ultimate tensile strength increases while degradation rate decreases after 5 HPT rotations. This study provides the potential of enhanced Fe‐based biomaterials for thinner and smaller implant designs.
Vortex Engineering on Oxide Bowl‐Coated Oxide/Gold Dual‐Layer Array for Dual Electrical/Spectroscopic Monitoring of Volatile Organic Compounds
Authors: Lu Yanyan , Yang Xiaowei , Bao Haoming , Lei Biao , Chen Kang , Wei Yi , Zhao Qian , Zhang Hongwen , Cai Weiping
Published: April 2024

Integrating real‐time electrical gas sensing and highly identifiable surface‐enhanced Raman spectroscopy (SERS) for volatile organic compounds (VOCs) monitoring holds significant potential for safeguarding public health and safety. However, this technique remains in the proof‐of‐concept stage because the performance and reproducibility of devices fall short of meeting the practical application requirements. This work addresses this challenge by employing vortex engineering on a bifunctional dual‐layer array of Ni‐doped SnO2 (Ni‐SnO2) bowl‐coated on Ni‐SnO2/Au/SiO2 and developing highly reproducible device fabrication. In the dual‐layer array, vortices generated in upper Ni‐SnO2 bowls slow down the VOC flow and direct its delivery to gaps between lower Ni‐SnO2/Au/SiO2 units that are critical to SERS and electrical sensing. Experimental results show that the vortex effect in the array enables a low limit of detection of 10 ppb with a response and recovery in seconds. The excellent practicality of the array has been demonstrated through a ca. 100 hours of quantitative dual‐monitoring of styrene in a spacious environment (~60 m3) with a 5‐meter distance between the leakage source and the array. This work advances dual‐monitoring sensors for practical applications and offers insights for designing gas‐sensing materials and devices.
Guest‐Induced Thermally Activated Delayed Fluorescence Organic Supramolcular Macrocycle Scintillators for High‐Resolution X‐Ray Imaging
Authors: Zhang Guozhen , Chen Fuhai , Di Yiming , Yuan Siqi , Zhang Yang , Quan Xin , Chen Yong , Chen Hongming , Lin Meijin
Published: April 2024

Organic scintillators, pivotal in security and medical applications, face challenges due to limited X‐ray absorption and exciton utilization. Herein, a novel class of organic scintillators is introduced, named guest‐induced thermally activated delayed fluorescence (TADF) within supramolecular macrocycles via host‐guest through‐space charge transfer (TSCT). Four co‐crystals are obtained through orthogonal crystallizations involving calix[3]acridan (C[3]A) and calix[3]phenothiazine (C[3]P) macrocycles as hosts, along with 1,2‐dicyanobenzene (DCB) and 4‐bromo‐1,2‐benzenedicarbonitrile (BrDCB) as guests. Interestingly, DCB@C[3]A and BrDCB@C[3]A co‐crystals exhibit strong host‐guest TSCT with reduced single‐triplet energy gap for efficient TADF emission, which leads to enhanced exciton utilization and X‐ray absorption, yielding radioluminescence intensities over 29 and 25 times higher than C[3]A. Similarly, substituting C[3]A with C[3]P, the obtained TADF co‐crystals also outperform C[3]P in scintillation performance. Additionally, the scintillation color of co‐crystals can be adjusted by varying the electron‐donating abilities of macrocycles and the electron‐accepting abilities of guests, offering a simpler color‐tuning mechanism than covalent‐bonded scintillators. Furthermore, the flexible film based on DCB@C[3]A exhibits promising application in X‐ray radiography, showcasing a high spatial resolution of 20 lp mm−1 @MTF = 0.77. The innovative strategy of fabricating organic scintillators via reversible non‐covalent interactions presents a novel solution for designing color‐tunable and high‐performance scintillators.
Atomically Dispersed Ga Synergy Lewis Acid‐Base Pairs in F‐doped Mesoporous Cu2O for Efficient Eletroreduction of CO2 to C2+ Products
Authors: Wang Jiahao , Ji Qinyuan , Zang Hu , Zhang Yan , Liu Changjiang , Yu Nan , Geng Baoyou
Published: April 2024

Electroreduction of CO2 into high‐value chemicals and fuels driven is an effective way to alleviate the environmental crisis, but it suffers from poor activity and low selectivity of the catalyst. Single‐atom catalysts have excellent selectivity and the highest atomic efficiency, and are widely used in the 2‐electron transfer to produce CO. However, electroreduction of CO2 to C2+ products involves complex processes such as multi‐electron reaction and competitive adsorption, so single‐atom catalysis is often powerless. Herein, a single‐atom Ga‐anchored F‐doped Cu2O catalyst with dual active sites is reported. The Lewis acid‐base pairs and Ga single atom sites promote the adsorption/activation of CO2 and the dissociation of water molecules, respectively, enhance the coverage of *CO and *H, and their synergy optimizes the reaction path. At a high current density of 600 mA cm−2, the FEC2+ reached 72.8 ± 3.2% with remarkable stability. Experiments and theory calculations demonstrate that the dual sites increase the coverage of *CO and *H, and the key intermediate *CO is transformed into *CHO through protonation reaction, which changes the reaction path from the C─C coupling (*OCCO) to the protonation followed by C─C coupling (*OCCHO) with low energy barrier, greatly improving the selectivity for C2+ products.
High‐Entropy Anti‐Perovskites with Enhanced Negative Thermal Expansion Behavior
Authors: Yuan Xiuliang , Wang Bing , Sun Ying , Guo Huaiming , Shi Kewen , Deng Sihao , He Lunhua , Lu Huiqing , Zhang Hong , Xu Shengdi , Du Yi , Hao Weichang , Chu Shengqi , Ma Zhijie , An Shihai , Cui Jin , Hu Dongmei , Han Huiming , Wang Cong
Published: April 2024

The negative thermal expansion (NTE) materials, which can act as thermal‐expansion compensators to counteract the positive thermal expansion, have great applications merit in precision engineering. However, the exploration of NTE behavior with a wide temperature range has reached its upper ceiling through traditional doping strategies due to composition limitations. In this paper, the unique sluggish characteristics and extended optimization space in empirically screened high‐entropy anti‐perovskite (HEAP) are utilized to broaden the NTE temperature range. Typically, the NTE temperature range in Mn3Cu0.2Zn0.2Ga0.2Ge0.2Mn0.2N is broadened to ΔT = 235 K (5 K ≤ T ≤ 240 K), which is two or three times wider than that of traditional low‐entropy doping systems. The neutron diffraction analysis reveals a unique sluggish characteristic in magnetic phase transition which survives in an ultra‐wide temperature range of 5 K ≤ T ≤ 350 K (ΔT = 345 K). The sluggish characteristic is further experimentally proved to come from disturbed phase transition dynamics due to distortion in atomic spacing and chemical environmental fluctuation observed by the spherical aberration‐corrected electron microscope. The demonstration provides a unique paradigm for broadening the temperature range of NTE materials through entropy engineering.
Boltzmann Switching MoS2 Metal–Semiconductor Field‐Effect Transistors Enabled by Monolithic‐Oxide‐Gapped Metal Gates at the Schottky–Mott Limit
Authors: Kim Yeon Ho , Jiang Wei , Lee Donghun , Moon Donghoon , Choi Hyun‐Young , Shin June‐Chul , Jeong Yeonsu , Kim Jong Chan , Lee Jaeho , Huh Woong , Han Chang Yong , So Jae‐Pil , Kim Tae Soo , Kim Seong Been , Koo Hyun Cheol , Wang Gunuk , Kang Kibum , Park Hong‐Gyu , Jeong Hu Young , Im Seongil , Lee Gwan‐Hyoung , Low Tony , Lee Chul‐Ho
Published: April 2024

A gate stack that facilitates a high‐quality interface and tight electrostatic control is crucial for realizing high‐performance and low‐power field‐effect transistors (FETs). However, when constructing conventional metal‐oxide‐semiconductor structures with two‐dimensional (2D) transition metal dichalcogenide channels, achieving these requirements becomes challenging due to inherent difficulties in obtaining high‐quality gate dielectrics through native oxidation or film deposition. Here, a gate‐dielectric‐less device architecture of van der Waals Schottky gated metal–semiconductor FETs (vdW‐SG MESFETs) using a molybdenum disulfide (MoS2) channel and surface‐oxidized metal gates such as nickel and copper is reported. Benefiting from the strong SG coupling, these MESFETs operate at remarkably low gate voltages, <0.5 V. Notably, they also exhibit Boltzmann‐limited switching behavior featured by a subthreshold swing of ≈60 mV dec−1 and negligible hysteresis. These ideal FET characteristics are attributed to the formation of a Fermi‐level (EF) pinning‐free gate stack at the Schottky–Mott limit. Furthermore, authors experimentally and theoretically confirm that EF depinning can be achieved by suppressing both metal‐induced and disorder‐induced gap states at the interface between the monolithic‐oxide‐gapped metal gate and the MoS2 channel. This work paves a new route for designing high‐performance and energy‐efficient 2D electronics.
Highly Reusable Electrochemical Immunosensor for Ultrasensitive Protein Detection
Authors: Singampalli Kavya L. , Neal – Harris Camille , Yee Cassian , Lin Jamie S. , Lillehoj Peter B.
Published: April 2024

The detection and quantification of protein biomarkers in bodily fluids is important for many clinical applications, including disease diagnosis and health monitoring. Current techniques for ultrasensitive protein detection, such as enzyme‐linked immunosorbent assay (ELISA) and electrochemical sensing, involve long incubation times (1.5–3 h) and rely on single‐use sensing electrodes which can be costly and generate excessive waste. This work demonstrates a reusable electrochemical immunosensor employing magnetic nanoparticles (MNPs) and dually labeled gold nanoparticles (AuNPs) for ultrasensitive measurements of protein biomarkers. As proof of concept, this platform is used to detect C‐X‐C motif chemokine ligand 9 (CXCL9), a biomarker associated with kidney transplant rejection, immune nephritis from checkpoint inhibitor therapy, and drug‐associated acute interstitial nephritis, in human urine. The sensor successfully detects CXCL9 at concentrations as low as 27 pg mL−1 within ≈1 h. This immunosensor was also adapted onto a handheld smartphone‐based diagnostic device and used for measurements of CXCL9, which exhibited a lower limit of detection of 65 pg mL−1. Lastly, this work demonstrates that the sensing electrodes can be reused for at least 100 measurements with a negligible loss in analytical performance, reducing the costs and waste associated with electrochemical sensing.
Rewiring Photosynthesis by Water‐Soluble Fullerene Derivatives for Solar‐Powered Electricity Generation
Authors: Zhu Huawei , Cabrerizo Franco M. , Li Jing , He Tao , Li Yin
Published: April 2024

Natural photosynthesis holds great potential to generate clean electricity from solar energy. In order to utilize this process for power generation, it is necessary to rewire photosynthetic electron transport chains (PETCs) of living photosynthetic organisms to redirect more electron flux toward an extracellular electrode. In this study, a semi‐artificial rewiring strategy, which use a water‐soluble fullerene derivative to capture electrons from PETCs and donate them for electrical current generation, is proposed. A positively charged fullerene derivative, functionalized with N,N‐dimethyl pyrrolidinium iodide, is found to be efficiently taken up by the cyanobacterium Synechocystis sp. PCC 6803. The distribution of this fullerene derivative near the thylakoid membrane, as well as site‐specific inhibitor assays and transient absorption spectroscopy, suggest that it can directly interact with the redox centers in the PETCs, particularly the acceptor side of photosystem I (PSI). The internalized fullerene derivatives facilitate the extraction of photosynthetic electrons and significantly enhance the photocurrent density of Synechocystis by approximately tenfold. This work opens up new possibility for the application of fullerenes as an excellent 3D electron carrier in living biophotovoltaics.
Alloying Driven Antiferromagnetic Skyrmions on NiPS3 Monolayer: A First‐Principles Calculation
Authors: Wang Yanxia , Xing Jianpei , Zhao Ying , Wang Yi , Zhao Jijun , Jiang Xue
Published: April 2024

Topological magnetic states are promising information carriers for ultrahigh‐density and high‐efficiency magnetic storage. Recent advances in two‐dimensional (2D) magnets provide powerful platforms for stabilizing various nanometer‐size topological spin textures within a wide range of magnetic field and temperature. However, non‐centrosymmetric 2D magnets with broken inversion symmetry are scarce in nature, making direct observations of the chiral spin structure difficult, especially for antiferromagnetic (AFM) skyrmions. In this work, it is theoretically predicted that intrinsic AFM skyrmions can be easily triggered in XY‐type honeycomb magnet NiPS3 monolayer by alloying of Cr atoms, due to the presence of a sizable Dzyaloshinskii–Moriya interaction. More interestingly, the diameter of the AFM skyrmions in Ni3/4Cr1/4PS3 decreases from 12 to 4.4 nm as the external magnetic field increases and the skyrmion phases remain stable up to an external magnetic field of 4 T. These results highlight an effective strategy to generate and modulate the topological spin texture in 2D magnets by alloying with magnetic element.
A Three‐in‐One Hybrid Strategy for High‐Performance Semiconducting Polymers Processed from Anisole
Authors: Liu Cheng , Liang Huanhuan , Xie Runze , Zhou Quanfeng , Qi Miao , Yang Chongqing , Gu Xiaodan , Wang Yunfei , Zhang Guoxiang , Li Jinlun , Gong Xiu , Chen Junwu , Zhang Lianjie , Zhang Zesheng , Ge Xiang , Wang Yuanyu , Yang Chen , Liu Yi , Liu Xuncheng
Published: April 2024

The development of semiconducting polymers with good processability in green solvents and competitive electrical performance is essential for realizing sustainable large‐scale manufacturing and commercialization of organic electronics. A major obstacle is the processability‐performance dichotomy that is dictated by the lack of ideal building blocks with balanced polarity, solubility, electronic structures, and molecular conformation. Herein, through the integration of donor, quinoid and acceptor units, an unprecedented building block, namely TQBT, is introduced for constructing a serial of conjugated polymers. The TQBT, distinct in non‐symmetric structure and high dipole moment, imparts enhanced solubility in anisole—a green solvent—to the polymer TQBT‐T. Furthermore, PTQBT‐T possess a highly rigid and planar backbone owing to the nearly coplanar geometry and quinoidal nature of TQBT, resulting in strong aggregation in solution and localized aggregates in film. Remarkably, PTQBT‐T films spuncast from anisole exhibit a hole mobility of 2.30 cm2 V‐1 s‐1, which is record high for green solvent‐processable semiconducting polymers via spin‐coating, together with commendable operational and storage stability. The hybrid building block emerges as a pioneering electroactive unit, shedding light on future design strategies in high‐performance semiconducting polymers compatible with green processing and marking a significant stride towards ecofriendly organic electronics.
Ultralow Strain‐Induced Emergent Polarization Structures in a Flexible Freestanding BaTiO3 Membrane
Authors: Wang Jie , Liu Zhen , Wang Qixiang , Nie Fang , Chen Yanan , Tian Gang , Fang Hong , He Bin , Guo Jinrui , Zheng Limei , Li Changjian , Lü Weiming , Yan Shishen
Published: April 2024

The engineering of ferroic orders, which involves the evolution of atomic structure and local ferroic configuration in the development of next‐generation electronic devices. Until now, diverse polarization structures and topological domains are obtained in ferroelectric thin films or heterostructures, and the polarization switching and subsequent domain nucleation are found to be more conducive to building energy‐efficient and multifunctional polarization structures. In this work, a continuous and periodic strain in a flexible freestanding BaTiO3 membrane to achieve a zigzag morphology is introduced. The polar head/tail boundaries and vortex/anti‐vortex domains are constructed by a compressive strain as low as ≈0.5%, which is extremely lower than that used in epitaxial rigid ferroelectrics. Overall, this study c efficient polarization structures, which is of both theoretical value and practical significance for the development of next‐generation flexible multifunctional devices.
High‐Performance Thermoelectric and Electromagnetic Interference Shielding Derived from MXene/Ag2Se Nanowire Composite Film
Authors: Park Dabin , Kim Minsu , Kim Jooheon
Published: April 2024

A flexible n‐type composite film consisting of MXene/Ag2Se nanowires (MX‐AS), is synthesized herein via a facile wet chemical sintering process. The thermoelectric properties of the composites with various MXene concentrations are systematically explored. The as‐synthesized 2D MXene exhibits homogeneous intercalation and dispersion of the Ag2Se nanowires. A comparative analysis reveals that these composite films outperform the pristine Ag2Se nanowire films fabricated using the same process. Specifically, the MX‐AS composite film containing 1.5 wt.% MXene exhibits a significant (≈1.25 times) improvement in the maximum thermoelectric power factor (PF), exhibiting a value of ≈933.4 µW m−1 K−2 at 400 K. This enhancement can be attributed to the combination of the remarkable intrinsic Seebeck coefficient of the Ag2Se and the high electrical conductivity of the MXene. Moreover, cyclic bending tests demonstrate the exceptional mechanical durability and flexibility of the composite film, with only an ≈7% decrease in the PF after 1000 cycles. In addition, the as‐prepared MX‐AS composite exhibits a high electromagnetic interference (EMI) shielding efficiency.