bluuebunny/crossref_metadata_2025 huggingface dataset:
Policy Entrepreneurs, Policy Opportunists, and Legislative Effectiveness
Authors: Weissert Carol S.
Published: March 2007

Although there is a growing literature on policy entrepreneurs and policy enactment, there has been little systematic examination of legislative policy entrepreneurs and the effect of policy entrepreneurship on a legislator's standing. This article identifies policy entrepreneurs in each of three sessions of the North Carolina General Assembly and examines the effect of policy entrepreneurship on legislators' effectiveness as perceived by peers and close observers. It also defines and identifies a second category —policy opportunists — legislators who have not exhibited expertise and persistence necessary for policy entrepreneurship but who are associated with salient issues whose "policy window" has opened. Both policy entrepreneurs and policy opportunists benefit from increases in their standing, but policy entrepreneurs benefit more than their opportunistic peers. The importance of the issue cycle is illustrated in the changing cast of legislative policy entrepreneurs and policy opportunists over the three sessions.
Cognitive Strategies and Candidate Evaluations
Authors: Riggle Ellen D.
Published: March 2007

Decades of voting behavior studies have found party affiliation, issue stands and ideology, and candidate image to be major factors influencing voter evaluations of candidates. The relative importance of these criteria, however, may depend on the context in which the information processing about the candidate occurs. Specifically, in this study, an experimentally designed survey is used to change the context of the judgment task from an absolute judgment of one candidate to a comparison judgment of two candidates. The results show that subjects changed from a discrete information processing strategy when judging one candidate to a heuristic processing strategy when judging two candidates. The implications for citizen evaluations of political candidates is discussed.
A Model of Nomination Preferences
Authors: Kenney Patrick J. , Rice Tom W.
Published: March 2007

In this article, the authors develop a model that details how individuals come to prefer one candidate over others during the presidential nomination campaign. The model places the forces that influence nomination preferences into a simultaneous and dynamic framework. Empirical tests using the 1980 NES panel data indicate that the model performs well.
Local Sources of Information and Voter Choice in State Elections
Authors: Bowler Shaun , Donovan Todd , Snipp Joseph
Published: March 2007

Previous studies of aggregated election returns have identified a local component to the vote in state election contests. The authors suggest that a geographical distribution of information about candidates produces these aggregate patterns and demonstrate that the farther a voter resides from a candidate's home media market, the less likely it is that the voter knows about the candidate. Furthermore, uncertainty associated with distance reduces the likelihood that a voter will select a candidate. This effect holds in partisan and nonpartisan (primary) contests. The findings call attention to the need for additional study of vehicles that transmit information at the local level.
Running on Their Own
Authors: KING JAMES D.
Published: March 2007

Senators who first reach office by gubernatorial appointment are successful at the polls at half the rate of incumbents in general. Outcomes of elections featuring appointed senators are affected by the incumbent's voting record in the Senate, the divisiveness of the primary, state partisanship, the size of the state, national political conditions, and the quality of the challenger. This last factor is the key to understanding the anomaly, as appointed senators face higher quality challengers than do senators who first gain office through the electoral process.
Survey Bias on the Front Porch
Authors: LEAL DAVID L. , HESS FREDERICK M.
Published: March 2007

We examine whether survey interviewers are biased in their views of certain classes of respondents, thereby introducing unobserved bias into survey results. There has been a great deal of previous research on how racial and gender dynamics affect the responses given by respondents during face-to-face surveys. In this article, we turn this issue around and ask whether human interaction affects how the interviewer views the respondents, and if so, how this may systematically bias surveys. If interviewers are biased, this may impede their ability to conduct interviews in a consistent, nonjudgmental, and unbiased manner. Using three surveys that required the interviewer to evaluate how informed and intelligent the respondents appeared, we found that interviewers were more likely to evaluate respondents of lower socioeconomic status as less informed and less intelligent, even after controlling for objective levels of political information. There is also evidence that Blacks may be negatively evaluated.
The Concept of Culture in International and Comparative HRD Research: Methodological Problems and Possible Solutions
Authors: Ardichvili Alexander , Kuchinke K. Peter
Published: March 2007

International and comparative research is one of the fastest growing areas of scholarly inquiry in HRD. All international HRD studies, regardless of specific topics of investigation, sooner or later refer to culture. Therefore, the treatment of culture in international HRD research is a matter of central importance. The goal of this article is to illuminate some of the central issues in international and comparative HRD research by helping HRD researchers to better understand the current approaches to culture and by discussing the methodological problems arising from the current use of the concept of culture. Several alternative approaches to culture in international research are analyzed and criticized. The authors close the article by outlining directions that might overcome the limitations of current approaches, help us to increase the utility of the international and comparative HRD research, and improve our ability to incorporate the cultural influences in our investigations.
Therapeutics in the Management of Spasticity
Authors: Gelber David A. , Jozefczyk Patricia B.
Published: March 2007

Spasticity is commonly defined as a velocity-dependent increase in tonic stretch re flexes that results from a variety of disorders affecting the brain and spinal cord. Treat ment of spasticity is generally considered when the increase in tone interferes with functional activities, such as positioning, mobility, or daily cares, when it is painful, or when it leads to complications such as contractures or skin breakdown. This re view discusses the pathophysiology of spasticity and details the various treatments avail able, including physical and occupational therapy modalities, use of splints and or thoses, oral and intrathecal medications, nerve blocks, botulinum toxin injections, and orthopedic and neurosurgical interventions.
Analytical Measurements of Package Components for Unintentional Migrants
Authors: Giacin Jack R. , Brzozowska Anna
Published: March 2007

The results of selected studies dealing with the transfer or migration of indirect additives from food contact materials to foodstuffs and/or their appropriate simulants have been reviewed in terms of the polymeric packaging material or packaging article, specific migrant, nature of the contact phase, level of migrant transferred under the conditions of test, and the analytical method employed to monitor com positional changes. The references presented on the analytical procedures developed for quantitation of migrated species are intended as a guide to the literature, where only representative studies have been reviewed.
A Novel Processing Aid for Greater Flexibility in Blown Film Extrusion
Authors: Schumacher Paul A.
Published: March 2007

The high melt viscosity of linear low density polyethylene (LLDPE) presents several problems, particularly melt fracture, when this resin is processed on blown film equipment which has been designed for use with high pressure, low density polyethylene (LDPE) resin. With the help of processing aids, the same equipment may be used to process LLDPE, LDPE and resin blends to produce blown films. Data is presented to show that the use of one of these processing aids, UCARSIL PA-1, results in blown film through narrow gap dies with improved properties while throughput rates are maintained without excessive pressures in the extrusion pro cess.
Creep Behavior of Oriented Pet: Films and Bottles
Authors: Gay Frank P.
Published: March 2007

Several authors [1-7] have discussed the influence of molecular weight and pro cessing conditions on the physical properties of products made from polyethylene terephthalate (PET). Since creep is an important and inevitable characteristic of polymers, it was decided to determine the affects of these factors on the creep of PET and then compare them to other plastics. Oriented PET turns out to be surprisingly resistant to creep, compared to many other polymers. However, it is possible to miss creep goals even with PET, if the balance of orientation and processing conditions is not controlled.
High-Rate Extrusion of Pvdc Polymers
Authors: Jenkins S.R. , Powers J.R. , Hyun K.S. , Naumovitz J.A.
Published: March 2007

The current extrusion technology for PVDC polymers is reviewed m detail Items covered include extruder screw design, controlled feeding, and screw temperature control The application of these principles to obtain rates of 185-195 kg/h is described
Effects of Bubble Cooling On Performance and Properties of Hmw-Hdpe Film Resins
Authors: Harris W.D. , Van Kerckhoven C.A.A. , Cantu L.K.
Published: March 2007

In the blown film process, bubble cooling significantly impacts the ori entation of the film and plays an intergral role in the physical perfomance of the finished product. This study describes the effects of cooling on the processing param eters and physical properties of HMW-HDPE film resins The effects of fabrication with internal bubble cooling (IBC) versus non-IBC at various neck heights are also explored. Physical properties as well as process information are provided which focus on film properties in both IBC and non-IBC configurations
Evaluation of the Performance of a New Tandem Air, Ring System
Authors: Perdikoulias John , Smith Dave
Published: March 2007

The purpose of this paper is to compare the performance of a typi cal dual lip air ring with that of the new Uni-Flo tandem air ring system. The goal is to determine whether the increased production rate attainable with the tandem air ring system has any adverse effects on the physical properties of the film. Both LDPE films and LLDPE/LDPE film samples were made and their physical properties analyzed by resin suppliers. There were some differences found when comparing the physical properties of the samples produced with the conventional air ring and those produced with the tandem air ring system. The magnitude of the effect also appears to be material dependent. The samples produced with the tandem air ring showed slight increase in gloss and a reduction in haze as compared to those produced on the conventional air ring.
Oxygen Permeability Measurements: Methodology Effects on Commercial LLDPE Film
Authors: Deschenes Louise , Rodrigue Natalie , Doyon Gilles , Wolynetz Mark S.
Published: March 2007

This paper investigates the effects of several parameters on the permeability measurement of LLDPE film used to package food. Measure ments were obtained using an OX-TRAN** 10/50 oxygen permeation instru ment. Permeability was higher in older film, increased with temperature and decreased under particular conditions with repeated testing. These results con firmed that careful procedures and sampling control are required to obtain reliable results and to optimize experimental effort.
Social Integration, System Integration and Collective Subjectivity
Authors: Domingues José Maurício
Published: March 2007

This article argues that Lockwood's piece on social and system integration was quite insightful at the time, but that it failed in correctly solving the issues it raised. More recent versions of the distinction, such as Giddens's and Archer's, are deemed not satisfactory either. Three steps are then taken in order to provide an alternative solution, which tackles the general problem of the relationship between structure and agency. The critical analysis of the notion of `emergent properties', along with those of `structure' and `mechanism', is the groundwork for a discussion of collective causality that substantiates an alternative view which defines social systems as collective subjectivities, including some methodological considerations. A broad notion of realism is upheld in the article.
Breast cancer screening – prevalence of disease in women who only respond after an invitation reminder
Authors: Hofvind Solveig
Published: March 2007

An analysis of the Norwegian Breast Cancer Screening Programme, including 1,390,310 screening examinations, showed an attendance rate of 71.7% in response to one invitation letter (ordinary attendees) and a further 4.5% increase only after an additional reminder (reminded attendees). Our aim was to examine the prevalence of breast cancer in ordinary and reminded attendees, the frequency of positive mammograms, and the positive predictive value in the two groups.

The prevalence of breast cancer in ordinary attendees was 5.6 per 1000 screens compared with 6.3 per 1000 screens in reminded attendees ( p<0.001). The frequencies of positive mammograms were 3.5% and 4.0% ( p<0.001), and the positive predictive values were 15.9% and 15.2% ( p=0.387), respectively, in ordinary and reminded attendees.

The risk of breast cancer is higher in women who respond only after a reminder letter, indicating that the value of sending a reminder should be assessed in the light of these results, as well as by the increase in the attendance rate.
Viral Infections
Authors: Harwood Catherine A. , Sterling Jane C.
Published: March 2024

Viruses can cause disease in the skin or mucosa by direct infection or, via a systemic infection, produce secondary skin abnormalities. The chapter reviews the viruses associated with skin lesions, outlining the pathophysiology, the clinical features, diagnostic methods and the approaches to treatment. Primary skin infection following direct contact occurs with poxviruses, some herpesviruses and papillomaviruses leading to visible features which may be readily diagnostic. Less specific skin changes are seen with systemic infections, when infection is often via mucosae or inoculation, for example with parvovirus, measles or coronavirus and for these infections, diagnosis will usually involve body fluid analysis.
Leprosy
Authors: Lockwood Diana N. J. , Walker Stephen L.
Published: March 2024

Leprosy is a chronic granulomatous disease caused by infection of the skin and nerves with
Mycobacterium leprae
and
M. lepromatosis
and about 220 000 new cases are diagnosed annually, 60% in India. The patient’s host immune response to the mycobacterium determines clinical presentation and the occurrence of immune‐mediated reactions and neuritis. Skin lesions range from anaesthetic macules to nodules. Diagnosis is clinically based on the type of skin lesions, peripheral nerve thickening and presence of mycobacteria in the skin. A skin biopsy is often useful in diagnosing leprosy. Nerve damage causes sensorimotor damage affecting the hands, feet and eyes. The infection is readily treatable with a combination of antibiotics (rifampicin, dapsone, clofazimine) but the associated nerve damage and inflammation is difficult to switch off and patients may need repeated courses of steroid treatment. Leprosy patients are still stigmatised and this needs combatting at all levels; most patients are not infectious.
Pityriasis Rubra Pilaris
Authors: Conrad Curdin
Published: March 2024

Pityriasis rubra pilaris represents a group of rare inflammatory skin disorders of unknown aetiopathology sharing common clinical and histopathological features. The disease is characterised by the appearance of hyperkeratotic follicular papules, which tend to coalesce to diffuse pink or red plaques, and a yellowish palmoplantar keratoderma. It may progress to erythroderma with characteristic distinct areas of uninvolved skin, the so‐called ‘islands of sparing’. Based on its age of onset, clinical presentation and prognosis, pityriasis rubra pilaris has been classified into distinct subtypes.
Xanthomas and Abnormalities of Lipid Metabolism and Storage
Authors: Flynn Paul D.
Published: March 2024

Xanthomas are frequently a sign of hypercholesterolaemia or other dyslipidaemias. Investigating and treating the underlying lipid disorders reduces the risk of their systemic complications: principally atherosclerotic cardiovascular disease and acute pancreatitis. This chapter describes the different xanthomas, the molecular basis of the associated dyslipidaemias and the expanding array of hypolipidaemic drugs.
Dermatoses of the External Ear
Authors: Kennedy Cameron , Sharma Ashish
Published: March 2024

The external ear comprises the pinna (auricle), the external auditory canal and the outer surface of the tympanic membrane. Numerous disorders can affect the ear, from childhood to old age. Ear malformations can arise as developmental abnormalities. Traumatic conditions include contusion, haematoma, split earlobes, pseudocyst, keloid and chondrodermatitis. Infections, including viral, bacterial and fungal, may manifest as acute or chronic otitis externa. Ear signs can be a manifestation of an underlying systemic disorder, such as autoimmune and inflammatory disease. Common cancers affecting the ear include basal cell carcinoma and squamous cell carcinoma, the latter carrying a risk of direct and metastatic spread.
Cutaneous Photosensitivity Diseases
Authors: Ibbotson Sally
Published: March 2024

The photodermatoses are a diverse group of conditions in which abnormal responses to light exposure are the hallmark. Photodiagnostic investigations through a specialist unit may be essential to ensure accurate diagnosis and management, and this chapter explores the nature of the photodermatoses and the photodiagnostic techniques that can be applied. Management approaches include early diagnosis, prevention and disease suppression, and awareness of the significant adverse impact on well‐being and psychological health that can occur with photosensitivity. Photoprotection is a mainstay approach for the photodermatoses but is often not sufficient alone for disease control. Desensitisation through natural hardening or light‐based therapies may be feasible, although systemic immunosuppressants and immunomodulators may be required. Awareness of the possibility of vitamin D deficiency is also necessary. This chapter will cover these approaches in detail.
Cutaneous Lymphomas
Authors: Whittaker Sean J.
Published: March 2024

Advances in the biology of lymphoid cells have greatly improved the classification and understanding of the pathogenesis of primary cutaneous lymphomas. Classification is based on clinical, pathological, immunopathological, molecular and cytogenetic findings and recognises that the site of origin of extranodal lymphomas and tumour morphology determines clinical behaviour, which in turn has a critical influence on prognosis and therapeutic approach. Mycosis fungoides and its variants are the most common primary cutaneous T‐cell lymphoma subset, but other subsets with clearly identifiable clinicopathological features and varying prognoses have also been described. A critical observation has been the realisation that lymphomas with a similar pathology arising in different organs have different prognoses and distinct pathogenesis: nodal CD30+ anaplastic large‐cell lymphomas are usually anaplastic lymphoma kinase (ALK) positive but ALK‐negative variants are associated with a poor prognosis, whereas primary cutaneous CD30+ anaplastic large‐cell lymphomas are invariably ALK negative and have a good prognosis. The majority of primary cutaneous B‐cell lymphomas also have an excellent prognosis, and primary cutaneous follicle centre lymphomas are pathogenetically distinct from nodal follicular lymphomas. Furthermore, it is appreciated that cutaneous and systemic T‐cell lymphomas are usually derived from specific tissue‐resident T‐cell subsets.
Error detection using a multi‐channel hybrid network with a low‐resolution detector in patient‐specific quality assurance
Authors: Yan Bing , Shi Jun , Xue Xudong , Peng Hu , Wu Aidong , Wang Xiao , Ma Chi
Published: March 2024

Purpose

This study aimed to develop a hybrid multi‐channel network to detect multileaf collimator (MLC) positional errors using dose difference (DD) maps and gamma maps generated from low‐resolution detectors in patient‐specific quality assurance (QA) for Intensity Modulated Radiation Therapy (IMRT).

Methods

A total of 68 plans with 358 beams of IMRT were included in this study. The MLC leaf positions of all control points in the original IMRT plans were modified to simulate four types of errors: shift error, opening error, closing error, and random error. These modified plans were imported into the treatment planning system (TPS) to calculate the predicted dose, while the PTW seven29 phantom was utilized to obtain the measured dose distributions. Based on the measured and predicted dose, DD maps and gamma maps, both with and without errors, were generated, resulting in a dataset with 3222 samples. The network's performance was evaluated using various metrics, including accuracy, sensitivity, specificity, precision, F1‐score, ROC curves, and normalized confusion matrix. Besides, other baseline methods, such as single‐channel hybrid network, ResNet‐18, and Swin‐Transformer, were also evaluated as a comparison.

Results

The experimental results showed that the multi‐channel hybrid network outperformed other methods, demonstrating higher average precision, accuracy, sensitivity, specificity, and F1‐scores, with values of 0.87, 0.89, 0.85, 0.97, and 0.85, respectively. The multi‐channel hybrid network also achieved higher AUC values in the random errors (0.964) and the error‐free (0.946) categories. Although the average accuracy of the multi‐channel hybrid network was only marginally better than that of ResNet‐18 and Swin Transformer, it significantly outperformed them regarding precision in the error‐free category.

Conclusion

The proposed multi‐channel hybrid network exhibits a high level of accuracy in identifying MLC errors using low‐resolution detectors. The method offers an effective and reliable solution for promoting quality and safety of IMRT QA.
Exploring the neurological features of individuals with germline PTEN variants: A multicenter study
Authors: Dhawan Andrew , Baitamouni Sarah , Liu Darren , Busch Robyn , Klaas Patricia , Frazier Thomas W. , Srivastava Siddharth , Parikh Sumit , Hsich Gary E. , Friedman Neil R. , Ritter David M. , Hardan Antonio Y. , Martinez‐Agosto Julian A. , Sahin Mustafa , Eng Charis
Published: March 2024

Objective

PTEN, a known tumor suppressor gene, is a mediator of neurodevelopment. Individuals with germline pathogenic variants in the PTEN gene, molecularly defined as PTEN hamartoma tumor syndrome (PHTS), experience a variety of neurological and neuropsychiatric challenges during childhood, including autism spectrum disorder (ASD). However, the frequency and nature of seizures and the utilization of allied health services have not been described.

Methods

Young patients with PHTS and sibling controls were recruited across five centers in the United States and followed every 6–12 months for a mean of 2.1 years. In addition to the history obtained from caregivers, neurodevelopmental evaluations and structured dysmorphology examinations were conducted, and brain MRI findings, received therapies, and epilepsy characteristics were reported.

Results

One hundred and seven patients with PHTS (median age 8.7 years; range 3–21 years) and 38 controls were enrolled. ASD and epilepsy were frequent among patients with PHTS (51% and 15%, respectively), with generalized epilepsy strongly associated with ASD. Patients with epilepsy often required two antiseizure medications. Neuroimaging revealed prominent perivascular spaces and decreased peritrigonal myelination in individuals with PHTS‐ASD. Allied therapy use was frequent and involved physical, occupational, speech, and social skills therapies, with 89% of all patients with PHTS, regardless of ASD diagnosis, utilizing at least one service.

Interpretation

This prospective, longitudinal study highlights the wide neurological spectrum seen in young individuals with PHTS. ASD is common in PHTS, comorbid with epilepsy, and allied health services are used universally. Our findings inform care discussions with families about neurological outcomes in PHTS.
NIDA: More than 11% of high school seniors use delta‐8
Authors: Knopf Alison
Published: March 2024

About 11% of 12th graders have used delta‐8 tetrahydrocannabinol (THC) in the past year, according to an analysis of last year's Monitoring the Future Study which is conducted by the National Institute on Drug Abuse (NIDA).
FDA warning on delta‐8
Authors: Knopf Alison
Published: March 2024

Here are five things you should know about delta‐8 THC to keep you and those you care for safe from products that may pose serious health risks.
HHS Office for Civil Rights opens investigation into UnitedHealthcareGroup cyberattack
Authors: Knopf Alison
Published: March 2024

Last week, the U.S. Department of Health and Human Services' Office for Civil Rights (OCR) issued a “Dear Colleague” letter addressing the cybersecurity incident impacting Change Healthcare, a unit of UnitedHealthcare Group (UHG), and many other health care entities. The cyberattack is disrupting health care and billing information operations nationwide and poses a direct threat to critically needed patient care and essential operations of the health care industry. OCR enforces the HIPAA Privacy, Security, and Breach Notification Rules, which require that HIPAA covered entities – virtually all health care providers, clearinghouses, and insurance companies – protect the privacy and security of protected health information. The likelihood that substance use disorder (SUD) treatment information was included in the breach is very likely. However, OCR does not mention 42 CFR Part 2, just HIPAA. HHS views ransomware and hacking as the “primary cyber threats in health care.” There has been a 256% increase in large breaches involving hacking, and a 264% increase in ransomware, over the last 5 years, and this only includes those breaches OCR was notified of. $22 million was reportedly paid to the Change Healthcare hackers, in the form of bitcoin, likely from UHG, according to news reports. HHS OCR says: “If you believe that your or another person's health information privacy or civil rights have been violated, you can file a complaint with OCR at https://www.hhs.gov/ocr/complaints/index.html.” The one bright side of the new Part 2 rules are that OCR now enforces the regulation.
Aptamers: Promising Reagents in Biomedicine Application
Authors: Zhou Hongxin , Li Yuhuan , Wu Weizhong
Published: March 2024

Nucleic acid aptamers, often termed “chemical antibodies,” are short, single‐stranded DNA or RNA molecules, which are selected by SELEX. In addition to their high specificity and affinity comparable to traditional antibodies, aptamers have numerous unique advantages such as wider identification of targets, none or low batch‐to‐batch variations, versatile chemical modifications, rapid mass production, and lack of immunogenicity. These characteristics make aptamers a promising recognition probe for scientific research or even clinical application. Aptamer‐functionalized nanomaterials are now emerged as a promising drug delivery system for various diseases with decreased side‐effects and improved efficacy. In this review, the technological strategies for generating high‐affinity and biostable aptamers are introduced. Moreover, the development of aptamers for their application in biomedicine including aptamer‐based biosensors, aptamer–drug conjugates and aptamer functionalized nanomaterials is comprehensively summarized.
Investigating the Microstructural and Mechanical Characteristics of Laser Additive‐Manufactured AlSi10Mg Specimens Through Experimental and Phase‐Field Modeling Approaches
Authors: Panda Bibhu Kalyan , Sahoo Seshadev , Kumar Cheruvu Siva , Nath Ashish Kumar
Published: March 2024

Metal‐based additive manufacturing can make complicated parts that are complex or expensive to cast and process. Rapid cooling rates increase laser powder bed fusion (LPBF's) mechanical properties during manufacturing. The objective of this study is to examine the impact of process parameters in the L‐PBF technique on the characteristics of microstructure and mechanical properties, specifically, on the nanohardness influenced by Si segregation. The microstructures of the produced specimens are examined using field‐emission scanning electron microscopy and the analysis identifies the existence of bimodal equiaxed α‐Al grains, accompanied by Si phases located within their grain boundaries. In addition, the solidified sample exhibits the segregation of secondary precipitates, particularly Mg2Si, which results in enhanced mechanical properties. Both cellular walls and Si precipitates impede the motion and generation of dislocations, thereby influencing the overall behavior of dislocations. The examination of segregation at the top layer is conducted in a comprehensive manner, subsequently using energy‐dispersive X‐ray spectroscopy for analysis. The presence of Mg2Si, Al2MgSi2, and other phases in all samples is confirmed through X‐ray diffraction. The as‐built samples’ residual stress under different process conditions is also investigated. Additionally, the obtained microstructure is compared to a phase‐field model to forecast the evolution of the microstructure.
Enhancement of Perpendicular Magnetic Anisotropy in Tm3Fe5O12(111) Epitaxial Films via Synergistic Stoichiometry and Strain Engineering
Authors: Liang Zhengguo , Lu Jingdi , Yang Shuo , Fang Zheng , Yan Yifei , Wang Qing , Li Peng , Fan Minghui , Wang Lingfei
Published: March 2024

Establishing a reliable control of perpendicular magnetic anisotropy (PMA) is challenging but essential for the full utilization of rare‐earth iron garnets in spintronic devices. In this study, a feasible approach to enhance the PMA of ferrimagnetic thulium iron garnet (TmIG) films is presented. This approach involves precise adjustments in cation stoichiometry and epitaxial strain state. By fine‐tuning the pre‐ablation process and oxygen partial pressure during pulsed laser deposition, a series of high‐quality TmIG films can grow with variable cation stoichiometry, i.e., the Tm/Fe molar ratio. The finding reveals that cation stoichiometry plays a crucial role in determining the magnetic properties of the TmIG films. Particularly, the stoichiometric TmIG film has the strongest PMA due to the maximized magnetostriction coefficient. Combining this stoichiometry optimization and strain engineering, an unprecedented PMA strength of ≈30 kJ m−3 for TmIG is achieved. This achievement demonstrates a simple and effective method for harnessing the magnetic properties of rare‐earth iron garnet films, paving the way for their advanced applications in next‐generation spintronic devices.
Highly Conductive PEDOT:PSS Aerogels
Authors: Feng Jiaojiao , Zhuang Zetong , Zhou Yiqing , Li Chun
Published: March 2024

Poly(3,4‐ethylenedioxythiophene):poly(4‐styrenesulfonate) (PEDOT:PSS) aerogel has attracted much attention in bioelectronics, electromagnetic shielding, and energy‐related systems due to its biocompatibility, intrinsic electronic conductivity, and favorable processability. However, fabrication of highly conductive and low‐density PEDOT:PSS aerogels is still challenging. In this work, highly conductive PEDOT:PSS aerogels are produced via ice‐templated pre‐assembly followed by a specially designed thawing process in H2SO4 solution. Upon optimization of heat and mass transfer during the thawing process, along with the unique ice template effect, the microstructure and thin walls of PEDOT:PSS frozen samples are well preserved. Importantly, the porous structure and thin walls facilitate diffusion of H2SO4 into polymer matrix, inducing phase separation of PEDOT:PSS, thus increasing PEDOT crystallinity and partially removing of PSS component. As a result, the as‐prepared pristine PEDOT:PSS aerogels exhibit a high electrical conductivity of 1200 ± 231 S m−1 along the freezing direction at a low density of 15.3 ± 1.5 mg cm−3, enhanced mechanical properties, and a competitive electromagnetic interference shielding efficiency of 25 115 dB cm2 g−1. Moreover, the compressed aerogels show good performances as active materials in symmetrical supercapacitors with thickness‐independent capacitance (maximum 2.1 F cm−2 at 1.0 mA cm−2) and in current collector‐free micro‐supercapacitors processed by laser carving.
Innovative Conversion Strategy for Wastewater with One‐Pot Uranium Extraction and Valuable Chemical Production by a Smart COF Photocatalyst
Authors: Guo Liecheng , Yang Yuting , Gong Lele , Zhang Qingyun , Liao Yuxin , Hua Rong , Yu Zhiwu , Luo Feng
Published: March 2024

Environmental protection and resource reclamation make the extraction of uranium from uranium‐containing wastewater be a key role in the nuclear chemistry and industry. Although previous studies have revealed several effective methods and materials for such use, however, few studies are concerned about the wastewater discharge issues. In fact, the direct discharge of treated wastewater into the environment is still not a green way. Here, an innovative conversion approach is shown, which can simultaneously achieve the uranium extraction and conversion of wastewater to valuable chemical. This concept is implemented by an azobenzene‐pendent covalent organic framework, showing smart trans‐to‐cis photoresponsive properties in both space and electronic structure and consequently, largely enhanced extraction and conversion efficiency under UV irradiation, relative to visible light irradiation. In real wastewater, the material is found to give selective and 100% uranium extraction and H2O2 generation (1872.3 µmol g−1 h−1). The mechanism is due to a unique photocatalysis coupling between the uranium reduction reaction (URR), aiming at uranium recovery or removal, and the water oxidation reaction (WOR), targeting the conversion of wastewater into a valuable chemical of H2O2.
Dual Alloying Enables High Thermoelectric Performance in AgSbTe2by Manipulating Carrier Transport Behavior
Authors: Zhang Kaiqi , Liu Shuang , Wang Xincan , Wu Shuai , Xiong Qihong , Wang Xue , Chen Junqi , Wang Guiwen , Zhang Bin , Fu Huixia , Han Guang , Wang Guoyu , Lu Xu , Zhou Yun , Zhou Xiaoyuan
Published: March 2024

AgSbTe2exhibits superior thermoelectric performance in the mid‐temperature region, but its electrical properties are strongly affected by intrinsic defects and secondary phases. Distinctively, the high mobility electrons still play an important role as minority carriers in p‐type AgSbTe2even below the bipolarization temperature and decrease the Seebeck coefficient. Here, the Al and Se dual alloying can effectively increase the hole concentration by reducing the cation vacancy formation energy and simultaneously reduce the electron concentration by suppressing the n‐type Ag2Te secondary phase are demonstrated, which results in the shift of carrier transport from two‐type to one‐type as confirmed by Hall measurement. Consequently, through adjusting the ratio of hole and electron conductivity, the average power factor of alloyed sample is enhanced by 70%. Combined with further reduced lattice thermal conductivity resulting from high‐density stacking faults and superstructures, a maximumzTof 1.90 and an averagezTof 1.42 are obtained in the temperature range of 323 to 623 K in the (AgSbTe2)0.98(AgAlSe2)0.02sample. Finally, based on the finite element analysis modeling results, both single‐leg and double‐leg thermoelectric devices are fabricated, which show high conversion efficiency of 11.2% and 5.2%, respectively.
Gradient‐Strained Van Der Waals Heterojunctions for High‐Efficient Photodetectors
Authors: Zeng Haoran , Yu Huihui , Liu Baishan , Lu Shucao , Wei Xiaofu , Gao Li , Hong Mengyu , Zhang Xiankun , Zhang Zheng , Zhang Yue
Published: March 2024

Maximizing light‐to‐electricity conversion efficiency is a crucial challenge for the practical applications of 2D material photodetectors. However, due to the lack of stable and precise electronic structure control methods for 2D materials, the driving force of photogenerated carriers is insufficient that severely hinders the efficiency of separation and transport. Herein, a gradient‐modulated, stable and precise strain applied strategy for 2D materials is designed and constructed, which results in a significant improvement in the detect efficiency of ZnO/WSe2/graphene van der Waals heterojunction photodetectors. Different from the overall strain of all‐component materials in typical photodetectors, biaxial tensile strain is applied to WSe2 that can be precisely modulated by controlling the height of ZnO nanorods, while the strain is nearly unaffected to ZnO. As the strain modulation increases from 1.3% to 4.0%, the external quantum efficiency (EQE) of the heterojunction increases from 11.4% to 35.3%, representing a threefold increase. Furthermore, with increasing strain, the EQE can reach higher levels. Moreover, the strain‐enhanced conversion efficiency mechanism is elucidated that results from the synergistic effect of the strain‐induced WSe2 exciton convergence and the strain‐increased ZnO/WSe2 interface barrier, which enhances the carrier interface separation efficiency.
Atomic Scale Structure of Self‐Assembled Lipidated Peptide Nanomaterials
Authors: Williams‐Noonan Billy J. , Kulkarni Ketav , Todorova Nevena , Franceschi Matteo , Wilde Christopher , Borgo Mark P. Del , Serpell Louise C. , Aguilar Marie‐Isabel , Yarovsky Irene
Published: March 2024

β‐Peptides have great potential as novel biomaterials and therapeutic agents, due to their unique ability to self‐assemble into low dimensional nanostructures, and their resistance to enzymatic degradation in vivo. However, the self‐assembly mechanisms of β‐peptides, which possess increased flexibility due to the extra backbone methylene groups present within the constituent β‐amino acids, are not well understood due to inherent difficulties of observing their bottom‐up growth pathway experimentally. A computational approach is presented for the bottom‐up modelling of the self‐assembled lipidated β3‐peptides, from monomers, to oligomers, to supramolecular low‐dimensional nanostructures, in all‐atom detail. The approach is applied to elucidate the self‐assembly mechanisms of recently discovered, distinct structural morphologies of low dimensional nanomaterials, assembled from lipidated β3‐peptide monomers. The resultant structures of the nanobelts and the twisted fibrils are stable throughout subsequent unrestrained all‐atom molecular dynamics simulations, and these assemblies display good agreement with the structural features obtained from X‐ray fiber diffraction and atomic force microscopy data. This is the first reported, fully‐atomistic model of a lipidated β3‐peptide‐based nanomaterial, and the computational approach developed here, in combination with experimental fiber diffraction analysis and atomic force microscopy, will be useful in elucidating the atomic scale structure of self‐assembled peptide‐based and other supramolecular nanomaterials.
Ultrafast Non‐Volatile Floating‐Gate Memory Based on All‐2D Materials
Authors: Wang Hao , Guo Hui , Guzman Roger , JiaziLa Nuertai , Wu Kang , Wang Aiwei , Liu Xuanye , Liu Li , Wu Liangmei , Chen Jiancui , Huan Qing , Zhou Wu , Yang Haitao , Pantelides Sokrates T. , Bao Lihong , Gao Hong‐Jun
Published: March 2024

The explosive growth of massive‐data storage and the demand for ultrafast data processing require innovative memory devices with exceptional performance. 2D materials and their van der Waal heterostructures with atomically sharp interfaces hold great promise for innovations in memory devices. Here, this work presents non‐volatile, floating‐gate memory devices with all functional layers made of 2D materials, achieving ultrafast programming/erasing speeds (20 ns), high extinction ratios (up to 108), and multi‐bit storage capability. These devices also exhibit long‐term data retention exceeding 10 years, facilitated by a high gate‐coupling ratio (GCR) and atomically sharp interfaces between functional layers. Additionally, this work demonstrates the realization of an “OR” logic gate on a single‐device unit by synergistic electrical and optical operations. The present results provide a solid foundation for next‐generation ultrahigh‐speed, ultralong lifespan, non‐volatile memory devices, with a potential for scale‐up manufacturing and flexible electronics applications.
In‐Synthesis Se‐Stabilization Enables Defect and Doping Engineering of HgTe Colloidal Quantum Dots
Authors: Yu Mengxuan , Yang Ji , Zhang Xingchen , Yuan Mohan , Zhang Jianbing , Gao Liang , Tang Jiang , Lan Xinzheng
Published: March 2024

Colloidal Quantum Dots (CQDs) of mercury telluride (HgTe) hold particular appeal for infrared photodetection due to their widely tunable infrared absorption and good compatibility with silicon electronics. While advances in surface chemistry have led to improved CQD solids, the chemical stability of HgTe material is not fully emphasized. In this study, it is aimed to address this issue and identifies a Se‐stabilization strategy based on the surface coating of Se on HgTe CQDs via engineering in the precursor reactivity. The presence of Se‐coating enables HgTe CQDs with improved colloidal stability, passivation, and enhanced degree of freedom in doping tuning. This enables the construction of optimized p‐i‐n HgTe CQD infrared photodetectors with an ultra‐low dark current 3.26 × 10−6 A cm⁻2 at −0.4 V and room‐temperature specific detectivity of 5.17 × 1011 Jones at wavelength ≈2 um, approximately one order of magnitude improvement compared to that of the control device. The stabilizing effect of Se is well preserved in the thin film state, contributing to much improved device stability. The in‐synthesis Se‐stabilization strategy highlights the importance of the chemical stability of materials for the construction of semiconductor‐grade CQD solids and may have important implications for other high‐performance CQD optoelectronic devices.
CogniFiber: Harnessing Biocompatible and Biodegradable 1D Collagen Nanofibers for Sustainable Nonvolatile Memory and Synaptic Learning Applications
Authors: Rokade Kasturi A. , Kumbhar Dhananjay D. , Patil Snehal L. , Sutar Santosh S. , More Krantiveer V. , Dandge Padma B. , Kamat Rajanish K. , Dongale Tukaram D.
Published: March 2024

Here, resistive switching (RS) devices are fabricated using naturally abundant, nontoxic, biocompatible, and biodegradable biomaterials. For this purpose, 1D chitosan nanofibers (NFs), collagen NFs, and chitosan–collagen NFs are synthesized by using an electrospinning technique. Among different NFs, the collagen‐NFs‐based device shows promising RS characteristics. In particular, the optimized Ag/collagen NFs/fluorine‐doped tin oxide RS device shows a voltage‐tunable analog memory behavior and good nonvolatile memory properties. Moreover, it can also mimic various biological synaptic learning properties and can be used for pattern classification applications with the help of the spiking neural network. The time series analysis technique is employed to model and predict the switching variations of the RS device. Moreover, the collagen NFs have shown good cytotoxicity and anticancer properties, suggesting excellent biocompatibility as a switching layer. The biocompatibility of collagen NFs is explored with the help of NRK‐52E (Normal Rat Kidney cell line) and MCF‐7 (Michigan Cancer Foundation‐7 cancer cell line). Additionally, the biodegradability of the device is evaluated through a physical transient test. This work provides a vital step toward developing a biocompatible and biodegradable switching material for sustainable nonvolatile memory and neuromorphic computing applications.
New Carbon Materials for Multifunctional Soft Electronics
Authors: Xue Jie , Liu Dan , Li Da , Hong Tianzeng , Li Chuanbing , Zhu Zifu , Sun Yuxuan , Gao Xiaobo , Guo Lei , Shen Xi , Ma Pengcheng , Zheng Qingbin
Published: March 2024

Soft electronics are garnering significant attention due to their wide‐ranging applications in artificial skin, health monitoring, human–machine interaction, artificial intelligence, and the Internet of Things. Various soft physical sensors such as mechanical sensors, temperature sensors, and humidity sensors are the fundamental building blocks for soft electronics. While the fast growth and widespread utilization of electronic devices have elevated life quality, the consequential electromagnetic interference (EMI) and radiation pose potential threats to device precision and human health. Another substantial concern pertains to overheating issues that occur during prolonged operation. Therefore, the design of multifunctional soft electronics exhibiting excellent capabilities in sensing, EMI shielding, and thermal management is of paramount importance. Because of the prominent advantages in chemical stability, electrical and thermal conductivity, and easy functionalization, new carbon materials including carbon nanotubes, graphene and its derivatives, graphdiyne, and sustainable natural‐biomass‐derived carbon are particularly promising candidates for multifunctional soft electronics. This review summarizes the latest advancements in multifunctional soft electronics based on new carbon materials across a range of performance aspects, mainly focusing on the structure or composite design, and fabrication method on the physical signals monitoring, EMI shielding, and thermal management. Furthermore, the device integration strategies and corresponding intriguing applications are highlighted. Finally, this review presents prospects aimed at overcoming current barriers and advancing the development of state‐of‐the‐art multifunctional soft electronics.
Engineering Covalent Organic Frameworks Toward Advanced Zinc‐Based Batteries
Authors: Zhang Qingqing , Zhi Peng , Zhang Jing , Duan Siying , Yao Xinyue , Liu Shude , Sun Zhefei , Jun Seong Chan , Zhao Ningning , Dai Lei , Wang Ling , Wu Xianwen , He Zhangxing , Zhang Qiaobao
Published: March 2024

Zinc‐based batteries (ZBBs) have demonstrated considerable potential among secondary batteries, attributing to their advantages including good safety, environmental friendliness, and high energy density. However, ZBBs still suffer from issues such as the formation of zinc dendrites, occurrence of side reactions, retardation of reaction kinetics, and shuttle effects, posing a great challenge for practical applications. As promising porous materials, covalent organic frameworks (COFs) and their derivatives have rigid skeletons, ordered structures, and permanent porosity, which endow them with great potential for application in ZBBs. This review, therefore, provides a systematic overview detailing on COFs structure pertaining to electrochemical performance of ZBBs, following an in depth discussion of the challenges faced by ZBBs, which includes dendrites and side reactions at the anode, as well as dissolution, structural change, slow kinetics, and shuttle effect at the cathode. Then, the structural advantages of COF‐correlated materials and their roles in various ZBBs are highlighted. Finally, the challenges of COF‐correlated materials in ZBBs are outlined and an outlook on the future development of COF‐correlated materials for ZBBs is provided. The review would serve as a valuable reference for further research into the utilization of COF‐correlated materials in ZBBs.