bluuebunny/crossref_metadata_2025 huggingface dataset:
Instructional Tool Development for Biodiversity and its Influence on Scientific Literacy and Higher Order Thinking Skills for High School Students
Authors: Hadiprayitno Gito , Muhlis Muhlis , Artayasa I. Putu , Suyantri Eni , Sukri Ahmad , Lestari Ayudya , Hariadi Ismawan
Published: August 2023

Biodiversity in high school that has been implemented so far has yet to use instructional tools that are oriented towards scientific literacy skills and higher-order thinking. Therefore, this research was intended to develop instructional tools for biodiversity, which aim to improve students’ scientific literacy and higher-order thinking skills. To do so, this research was carried out by adopting the Borg and Gall development model, which consisted of 4 stages, namely (1) needs analysis, (2) model design and development, (3) model validation, and (4) dissemination. The instruments included teaching material validation instruments, instructional tool instruments, and learning tool effectiveness instruments. Lastly, the data were analyzed descriptively and using ANCOVA (Analysis of Covariance. The results showed that (1) based on the expert validation of the Biodiversity instructional tools developed in this study, were categorized as feasible to be implemented in learning activities with a score of 3.90; (2) The practicality of the developed Biodiversity learning tools has been well implemented (score 3.78); and responded well by students (score 3.01) and responded very well by teachers (score 3.63); (3) Implementation of Biodiversity learning tools shows better achievement of scientific literacy and higherorder thinking skills compared to conventional learning; and (4) the results of the Ancova test showed that the Biodiversity learning tools had an influence on students’ scientific literacy and higher order thinking skills (p<0.05). Overall, the results of developing Biodiversity instructional tools are effective in increasing the scientific literacy skills and higher-order thinking of high school students.
Age at Menarche, Menopause Status and Metabolic Syndrome and its
Components: Findings from the Henan Rural Cohort Study
Authors: Wu Xueyan , Zhen Du , Liu Xiaotian , Liao Wei , Dong Xiaokang , Yang Jing , Zhao Bing , Wang Chongjian
Published: August 2023

Introduction To evaluate the effect of age at menarche on metabolic
syndrome (Mets) and its components and explore the impact of menopause status on
the association between age at menarche and Mets in rural Chinese women.

Methods This cross-sectional study enrolled 23382 women from the Henan
Rural Cohort study. The relationship between age at menarche and Mets was
assessed using logistic regression and restricted cubic spline. Interaction
plots were used to describe interactive eﬀects of age at menarche and
menopause status on Mets.

Results Age at menarche was inversely associated with the risk of Mets with
the adjusted OR of 1.16, 0.98, 1.00, 0.82, and 0.77, respectively, for those
with age at menarche≤13, 14, 15–16 (reference), 17,
and≥18 years. Each year of delay in menarche age correlated with a
6.2% (P<0.001) lower risk of Mets. Among the components
of Mets, an inverse association was observed between age at menarche and central
obesity (OR (95% CI): 0.92 (0.90, 0.94)), abnormal FPG (OR (95%
CI): 0.96 (0.94, 0.97)), abnormal BP (OR (95% CI): 0.967 (0.95, 0.98)),
abnormal TG (OR (95% CI): 0.96 (0.94, 0.97)), and abnormal HDL-C (OR
(95% CI): 0.96 (0.95, 0.98)). Significant interactions were discovered
between age at menarche, menopause status, and the risk of Mets, central
obesity, abnormal FPG, abnormal BP, and abnormal TG (all
P
interaction<0.001). The adverse effect of
menopausal status on Mets, central obesity, abnormal FPG, abnormal BP, and
abnormal TG decreased with delayed age at menarche.

Conclusions Later menarche was associated with a lower risk of Mets. More
importantly, the deleterious effect of menopause status on Mets decreased with
the increase in age at menarche.
Eine retrospektive Studie über einen 30-jährigen
Zeitraum von medizinischen Krafttraining als Therapieoption bei 101.000
chronischen Rückenpatienten
Authors: Hollmann Michael , Armbrüster Luca , Uhlig Hermann , Jäger Klaus , Schifferdecker-Hoch Frank
Published: August 2023

Rückenschmerzen stellen ein großes allgemeines Gesundheitsproblem
dar und verursachen hohe volkswirtschaftliche Kosten. Sie
beeinträchtigen die Lebensqualität der Patienten erheblich und
können zu einer reduzierten Teilhabe am sozialen Leben führen.
Dabei sind die Ursachen von Rückenschmerzen vielfältig und
erfordern einen biopsychosozialen Ansatz zur Diagnostik und Therapie, besonders
um den hohen Anteil funktioneller Störungen von dominierend organischen
Erkrankungen abzugrenzen. In der vorliegenden Studie wird die Wirksamkeit und
Wirtschaftlichkeit einer unter diesen Bedingungen stattfindenden
gerätegestützten Rückenschmerztherapie an über
100.000 chronischen Rückenschmerzpatienten aus einem Zeitraum von 30
Jahren untersucht. Die Teilnehmer nahmen an 24 Therapieeinheiten in einem
Therapiezentrum teil. Vor und nach der Therapie wurden Maximalkraftmessungen der
Rumpf- und Nackenmuskulatur durchgeführt und die Teilnehmer zu
Trainingshäufigkeit, Schmerz und Lebensqualität befragt. Die
Ergebnisse zeigen durchweg signifikante Verbesserungen aller analysierten
Parameter (p<0,001). So erreichen die Patienten Verbesserungen in Kraft,
Schmerz, Lebensqualität sowie ökonomischen Parametern. Aus den
Ergebnissen ergibt sich außerdem eine Steigerung der gesunden
Lebensjahre für die Teilnehmer. Die Studie zeigt somit, dass
spezifisches, adäquat eingesetztes Training eine Verbesserung der
Rückenschmerzen zur Folge hat. Die Beurteilung des Trainings-
beziehungsweise Therapieerfolgs erfolgt dabei nicht nur über den reinen
Kraftgewinn, sondern auch über patientenzentrierte Erfolgsparameter wie
Schmerzen oder Lebensqualität. Auch die wirtschaftliche Wirksamkeit der
Maßnahme ist zweifelsfrei gegeben, da signifikante Reduktionen in allen
untersuchten ökonomischen Parametern festgestellt wurden.
Darüber hinaus gewinnen Patienten durch die Teilnahme an gesunden
Lebensjahren hinzu, die zuvor durch ihre Rückenschmerzen minimiert
waren.
Guided Anti-P2Y12 Therapy in Patients Undergoing PCI: Three Systematic Reviews with Meta-analyses of Randomized Controlled Trials with Homogeneous Design
Authors: Birocchi Simone , Rocchetti Matteo , Minardi Alessandro , Podda Gian Marco , Squizzato Alessandro , Cattaneo Marco
Published: August 2023

Background The value of guided therapy (GT) with anti-P2Y12 drugs in percutaneous coronary intervention (PCI) is unclear. Meta-analyses lumped together randomized controlled trials (RCTs) with heterogeneous designs, comparing either genotype-GT or platelet function test (PFT)-GT with unguided therapy. Some meta-analysis also included RCTs that did not explore GT, but included the effects of switching patients with high on-treatment platelet reactivity (HTPR) to alternative therapies (HTPR-Therapy). We performed three distinct systematic reviews/meta-analyses, each exploring only RCTs with homogeneous design.

Methods MEDLINE, Embase, and Central databases were searched for RCTs testing genotype-GT, PFT-GT, or HTPR-Therapy in PCI-treated patients, through October 1, 2022. Two reviewers extracted the data. Risk ratios (RRs) (95% confidence intervals) were calculated. Primary outcomes were major bleedings (MBs) and major adverse cardiovascular events (MACE).

Results In seven genotype-GT RCTs, RRs were: MB, 1.06 (0.73–1.54; p = 0.76); MACE, 0.65 (0.47–0.91; p = 0.01), but significant risk reduction was observed in RCTs performed in China (0.30, 0.16–0.54; p < 0.0001) and not elsewhere (0.75, 0.48–1.18; p = 0.21). In six PFT-GT RCTs, RRs were: MB, 0.91 (0.64–1.28, p = 0.58); MACE, 0.82 (0.56–1.19; p = 0.30): 0.62 (0.42–0.93; p = 0.02) in China, 1.08 (0.82–1.41; p = 0.53) elsewhere. In eight HTPR-Therapy RCTs, RRs were: MB, 0.71 (0.41–1.23; p = 0.22); MACE, 0.57 (0.44–0.75; p < 0.0001): 0.56 (0.43–0.74, p < 0.0001) in China, 0.58 (0.27–1.23, p = 0.16) elsewhere.

Conclusion No GT strategy affected MB. Overall, genotype-GT but not PFT-GT reduced MACE. However, genotype-GT and PFT-GT reduced MACE in China, but not elsewhere. PFT-GT performed poorly compared to HTPR-Therapy, likely due to inaccurate identification of HTPR patients by PFT.
A New Arthroscopic Classification of Triangular Fibrocartilage Complex Disorders
Authors: Herzberg Guillaume , Burnier Marion , Ly Lyliane , Nakamura Toshiyatsu , Piñal Francisco del , Atzei Andrea
Published: August 2023

Introduction The use of wrist arthroscopy has become a prerequisite for diagnosis and treatment of triangular fibrocartilage complex (TFCC) disorders. Since Palmer's landmark paper, many new arthroscopic descriptions of TFCC tears have been published but there is no currently available updated comprehensive arthroscopic classification of TFCC lesions.

Purpose We recently described the arthroscopic anatomy of the TFCC as viewed from a 3–4 portal. Our purpose was to propose a new TFCC disorders classification based on this new arthroscopic TFCC description.

Methods We included all currently described TFCC disorders to the best of our knowledge into our arthroscopic, functional, and vascular anatomical concept. We also included patient's specific ulnar variance and distal radial ulnar joint coronal inclination as baseline treatment-oriented parameters. The fresh or chronic, reparable or nonreparable nature of some types of TFCC tears were considered as separate parameters.

Results The proposed classification includes disc “D” (degenerative or traumatic), reins “R” (traumatic), and wall “W” (traumatic) lesions. Combined lesions of those three parts of the TFCC may be easily identified. This new classification should facilitate future analysis of isolated or combined TFCC disorders whether they are degenerative and/or traumatic.

Discussion The authors present a new three-dimensional-three-part arthroscopic updated description of TFCC disorders with relevance to etiology and treatment principles.
Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection
Authors: Yilmaz Sumeyye , Gorgun Emre
Published: August 2023

Up to 15% of colorectal polyps are amenable for conventional polypectomy. Advanced endoscopic resection techniques are introduced for the treatment of those polyps. They provide higher en bloc resection rates compared with conventional techniques, while helping patients to avoid the complications of surgery. Note that 20 mm is considered as the largest size of a polyp that can be resected by polypectomy or endoscopic mucosal resection (EMR) in an en bloc fashion. Endoscopic submucosal dissection (ESD) is recommended for polyps larger than 20 mm. Intramucosal carcinomas and carcinomas with limited submucosal invasion can also be resected with ESD. EMR is snare resection of a polyp following submucosal injection and elevation. ESD involves several steps such as marking, submucosal injection, incision, and dissection. Bleeding and perforation are the most common complications following advanced endoscopic procedures, which can be treated with coagulation and endoscopic clipping. En bloc resection rates range from 44.5 to 63% for EMR and from 87.9 to 96% for ESD. Recurrence rates following EMR and ESD are 7.4 to 17% and 0.9 to 2%, respectively. ESD is considered enough for the treatment of invasive carcinomas in the presence of submucosal invasion less than 1000 μm, absence of lymphovascular invasion, well–moderate histological differentiation, low-grade tumor budding, and negative resection margins.
Evidence for a Pathogenic Role of CSMD1 in Childhood Apraxia of Speech
Authors: Formicola Daniela , Podda Irina , Pantaleo Marilena , Andreucci Elena , Lopergolo Diego , Giglio Sabrina , Santorelli Filippo Maria , Chilosi Anna
Published: August 2023

Childhood apraxia of speech (CAS) is a pediatric motor speech disorder. The genetic etiology of this complex neurological condition is not yet well understood, although some genes have been linked to it. We describe the case of a boy with a severe and persistent motor speech disorder, consistent with CAS, and a coexisting language impairment.

Whole exome sequencing in our case revealed a de novo and splicing mutation in the CSMD1 gene.
Unmet Needs in Geriatric Oncology
Authors: Pathi Nikhil , Parikh Purvish Mahendra , Banerjee Joyita , Tilak TVSVGK , Prem Naganath Narsimhan , Pillai Anupa
Published: August 2023

India's population is aging, with the number of people aged 60 and over projected to reach 340 million by 2050. This is expected to lead to an increase in the number of older adults with cancer. Geriatric oncology is a rapidly growing field in India that is facing several challenges. Some of these include inadequate access to cancer screening and early detection programs in elderly, leading to late diagnoses and poor outcomes, lack of specialized geriatric oncology services, cancer-specific treatment guidelines and protocols in elderly, limited availability of treatment options due to accessibility, finances and other logistic issues, lack of trained healthcare professionals with expertise in geriatric oncology, lack of awareness, and access to early integrated palliative care services. There are several challenges faced by elderly in this journey like financial dependency, social isolation, difficulty in transportation to healthcare for treatments, and psychosocial aspects attributed to cancer. Awareness about availability of resources, patient assistance programs to reduce financial burdens, education campaigns, use of telemedicine and telehealth services to bypass transportation issues in remote and underserved areas, and integration of geriatric oncology into mainstream oncology services might be some solutions. Additionally, there is a need for more research on the unique characteristics and needs of older cancer patients in India, as well as the development of culturally appropriate interventions to address these needs. Development of India-specific geriatric assessment scales encompassing medical, psychosocial, and functional problems in elderly identifies areas of vulnerability. A multidisciplinary team-based decision-making is required at various levels. There is a need for increased investment in geriatric oncology research, training, and integrated palliative care services in India. Geriatric oncology is slowly being recognized as a separate subspeciality and more geriatric oncology centers and clinics are being set up in major cities in India that should be the way forward.
History of Neurointervention
Authors: Sahoo Anurag , Abdalkader Mohamad , Saatci Isil , Raymond Jean , Qiu Zhongming , Huo Xiaochuan , Sun Dapeng , Weyland Charlotte S. , Jia Baixue , Zaidat Osama O. , Hu Wei , Qureshi Adnan I. , Miao Zhongrong , Nguyen Thanh N.
Published: August 2023

In this review article, we aim to provide a summary of the discoveries and developments that were instrumental in the evolution of the Neurointerventional field. We begin with developments in the advent of Diagnostic Cerebral Angiography and progress to cerebral aneurysm treatment, embolization in AVMs and ischemic stroke treatment. In the process we discuss many persons who were key in the development and maturation of the field. A pivotal aspect to rapid growth in the field has been the multidisciplinary involvement of the different neuroscience specialties and therefore we close out our discussion with excitement about ongoing and future developments in the field with a focus on treatments in the non-cerebrovascular disease realm.
Clinical and microbiology profile of typhoidal and nontyphoidal Salmonella blood stream infection: An observational study from a university hospital
Authors: Siddiqui Tasneem , Sinha Richa , Singh Patel Sangram , Sahu Chinmoy
Published: August 2023

Objectives:

Species distribution and antibiotic resistance pattern of Salmonella varies with time and place. Rapid and correct use of antibiotics requires understanding of the distribution and drug resistance patterns. Therefore, we aimed to study the clinical profile of patients along with speciation and antibiogram of Salmonella isolates from blood.

Materials and Methods:

It is an observational study, conducted from December 2019 to December 2021 at our university hospital. Blood cultures were processed by automated blood culture system. Salmonella isolates were identified by their morphological properties, biochemical reaction, and serological tests. Antibiotic susceptibility pattern was assessed by Kirby–Bauer’s disc diffusion method and Phoenix automated system.

Results:

The male-to-female ratio of the patients in the study was 2.5:1 and the mean age of the patients was 11.7 years (1–27 years). Salmonella spp. was isolated from 21 patients out of 1,350 positive blood cultures. Nine isolates were identified as S. Typhi seven as S. Choleraesuis three as S. Paratyphi A and two as S. Paratyphi B. Immuno-compromised conditions were significantly associated in nontyphoidal Salmonella bacteremia (p = 0.0253). Isolates showed maximum resistance toward nalidixic acid (100%) followed by fluoroquinolones (52.4%). Multidrug resistance, extreme drug resistance, and azithromycin resistance was seen in 14.3, 4.8, and 4.8% isolates, respectively. Posttreatment recovery was observed in 20 patients.

Conclusions:

Emergence of S. Choleraesuis among Salmonella spp. in blood stream infection, next only to S. Typhi was noted. Rising drug resistance is a matter of concern.
Hamiltonian structure of rational isomonodromic deformation systems
Authors: Bertola M. , Harnad J. , Hurtubise J.
Published: August 2023

The Hamiltonian approach to isomonodromic deformation systems is extended to include generic rational covariant derivative operators on the Riemann sphere with irregular singularities of arbitrary Poincaré rank. The space of rational connections with given pole degrees carries a natural Poisson structure corresponding to the standard classical rational R-matrix structure on the dual space L*gl(r) of the loop algebra Lgl(r). Nonautonomous isomonodromic counterparts of isospectral systems generated by spectral invariants are obtained by identifying deformation parameters as Casimir elements on the phase space. These are shown to coincide with higher Birkhoff invariants determining local asymptotics near to irregular singular points, together with the pole loci. Pairs consisting of Birkhoff invariants, together with the corresponding dual spectral invariant Hamiltonians, appear as “mirror images” matching, at each pole, the negative power coefficients in the principal part of the Laurent expansion of the fundamental meromorphic differential on the associated spectral curve with the corresponding positive power terms in the analytic part. Infinitesimal isomonodromic deformations are shown to be generated by the sum of the Hamiltonian vector field and an explicit derivative vector field that is transversal to the symplectic foliation. The Casimir elements serve as coordinates complementing those along the symplectic leaves, defining a local symplectomorphism between them. The explicit derivative vector fields preserve the Poisson structure and define a flat transversal connection, spanning an integrable distribution whose leaves may be identified as the orbits of a free Abelian local group action. The projection of infinitesimal isomonodromic deformation vector fields to the quotient manifold under this action gives commuting Hamiltonian vector fields corresponding to the spectral invariants dual to the Birkhoff invariants and the pole loci.
User-friendly microfluidic system reveals native-like morphological and transcriptomic phenotypes induced by shear stress in proximal tubule epithelium
Authors: Khalil Natalie N. , Petersen Andrew P. , Song Cheng J. , Chen Yibu , Takamoto Kaelyn , Kellogg Austin C. , Chen Elaine Zhelan , McMahon Andrew P. , McCain Megan L.
Published: August 2023

Drug-induced nephrotoxicity is a leading cause of drug attrition, partly due to the limited relevance of pre-clinical models of the proximal tubule. Culturing proximal tubule epithelial cells (PTECs) under fluid flow to mimic physiological shear stress has been shown to improve select phenotypes, but existing flow systems are expensive and difficult to implement by non-experts in microfluidics. Here, we designed and fabricated an accessible and modular flow system for culturing PTECs under physiological shear stress, which induced native-like cuboidal morphology, downregulated pathways associated with hypoxia, stress, and injury, and upregulated xenobiotic metabolism pathways. We also compared the expression profiles of shear-dependent genes in our in vitro PTEC tissues to that of ex vivo proximal tubules and observed stronger clustering between ex vivo proximal tubules and PTECs under physiological shear stress relative to PTECs under negligible shear stress. Together, these data illustrate the utility of our user-friendly flow system and highlight the role of shear stress in promoting native-like morphological and transcriptomic phenotypes in PTECs in vitro, which is critical for developing more relevant pre-clinical models of the proximal tubule for drug screening or disease modeling.
Lead-free CsCu2Br3 perovskite for multilevel resistive switching memory
Authors: Hu Jingyang , Gao Long , Li Wentong , Wang Meng , Cheng Tuo , Li Zhe , Zhang Xiaoyu , Wang Yinghui , Zhang Jiaqi
Published: August 2023

Organic–inorganic metal halide perovskites have recently attracted enormous interest in the field of resistive switching memories owing to their unique electrical properties. Unfortunately, two challenges, the inadequate long-term stability and the toxicity of lead, largely hinder their further practical application. Herein, a 1D all-inorganic lead-free CsCu2Br3 perovskite is proposed for resistive switching devices to resolve these issues. The CsCu2Br3-based resistive switching devices exhibit typical bipolar resistive switching behavior with low set voltage, high on/off ratio (103), stable retention properties (>2 × 104 s), and endurance (200 cycles) in air. The unencapsulated CsCu2Br3-based device still maintains resistive switching characteristics while stored in ambient environment for over 2 months. Moreover, four on-state multilevel information storage behavior has been observed by regulating the value of compliance current during set process. The resistive switching behavior is dominated by the formation and fracture of conductive filaments, which are induced by the movement of Br− ions under electrical bias. This work offers the opportunity and strategy for the design of air-stable and environment-friendly metal halide perovskite-based memory devices.
The influence of a combined aerator on aeration characteristics
Authors: Zhang Pengfei , Song Kai , Chen Chaoxu , Yang Zhengli
Published: August 2023

Aerators with sharp lateral enlargements and bottom drops generally cause adverse effects in spillway tunnels with a mild base slope, including serious cavity back flow and water wings striking the tunnel roof. Taking RM Hydropower Station’s spillway tunnel as its example, this paper proposes a new type of combined aerator characterized by a “variable base slope” longitudinally and a transverse “sharp enlargement plus straight section.” This not only increases cavity stability, resulting in more effective aeration, but also inhibits the development of water wings, contributing to an improved pattern of water flow. In addition, this paper systematically explores the influence of the flip bucket (drop), gently sloping section, and steeply sloping section of the “variable base slope” aerator upon the aerated cavity and summarizes the rules according to which the sharp lateral enlargement and diffusion angle influence the formation of water wings. This offers technical solutions, with theoretical support, for the design of aerators in spillway tunnels with a mild base slope.
Detailed analysis of banded chorus gap formation by an electron shell distribution
Authors: Min Kyungguk
Published: August 2023

In a recent paper [K. Min, Phys. Plasmas 30, 012904 (2023)], the formation of the banded chorus with a gap in intensity at half the electron cyclotron frequency (Ωe/2) is demonstrated by particle-in-cell simulations including an isotropic shell distribution at an intermediate energy. This follow-up study focuses on the phase space density (PSD) hill formation process and its role in the chorus wave damping at the gap. We first show that phase-trapped particles closely follow single wave characteristics in momentum space. This means that the formation of either PSD hole or hill is primarily determined by the temperature anisotropy, T⊥/T‖, of an initial distribution function. The critical value of T⊥/T‖ increases (decreases) for a higher (lower) resonant frequency. We then revisit the recent banded chorus simulations to investigate how the presence of an isotropic shell distribution self-consistently affects chorus wave evolution at the gap. Initially, with an increasing wave frequency, more and more shell electrons get trapped and a PSD hill is formed. The enhanced PSD hill counteracts wave growth driven by phase-trapped anisotropic electrons and subsequently reduces wave amplitude. The weakened wave self-consistently feeds back to the particle trapping, ultimately suppressing both the PSD hole and hill. By the time the wave frequency reaches about 0.45Ωe, the gyro-phase structure of the electron distribution becomes much less organized. In some cases, however, the wave growth at the upstream source region can be strong enough that waves still manage to go through the gap frequency, suggesting that additional process(es) should likely be accompanied.
Design of the Lanthanum hexaboride based plasma source for the large plasma device at UCLA
Authors: Qian Yuchen , Gekelman Walter , Pribyl Patrick , Sketchley Tom , Tripathi Shreekrishna , Lucky Zoltan , Drandell Marvin , Vincena Stephen , Look Thomas , Travis Phil , Carter Troy , Wan Gary , Cattelan Mattia , Sabiston Graeme , Ottaviano Angelica , Wirz Richard
Published: August 2023

The Large Plasma Device (LAPD) at UCLA (University of California, Los Angeles) produces an 18 m long, magnetized, quiescent, and uniform plasma at a high repetition rate to enable studies of fundamental plasma physics. Here, we report on a major upgrade to the LAPD plasma source that allows for more robust operation and significant expansion of achievable plasma parameters. The original plasma source made use of a heated barium oxide (BaO) coated nickel sheet as an electron emitter. This source had a number of drawbacks, including a limited range of plasma density (≲4.0 × 1012 cm−3), a limited discharge duration (∼10 ms), and susceptibility to poisoning following oxygen exposure. The new plasma source utilizes a 38 cm diameter lanthanum hexaboride (LaB6) cathode, which has a significantly higher emissivity, allowing for a much larger discharge power density, and is robust to exposure to air. Peak plasma density of up to 3.0 × 1013 cm−33 in helium gas has been achieved. The typical operating pressure is ∼10−5 Torr, while dynamic pressure can be achieved through the gas-puffing technique. Discharges as long as 70 ms have been produced, enabling a variety of long-time-scale studies of processes, such as turbulent particle transport. The new source has been in continuous operation for 14 months, having survived air leaks, power outages that led to rapid temperature changes on the cathode and heater, and planned machine openings. We describe the design, construction, and initial operation of this novel new large-area LaB6 plasma source.
Effect of passivation on buried interface of CsPbI2Br perovskite films
Authors: Yang Xingming , Jiang Junjie , Xu Cuiping , Ji Peiqi , Xu Ziyi , Ma Ligang , Cai Hongling , Zhang Fengming , Wu Xiaoshan
Published: August 2023

Passivation on the surface or interface is one of the key issues in fabricating the efficient and stable perovskite solar cells (PSCs). In this Letter, we report a way to passivate the buried interface on the perovskite film by optimizing the growth kinetics of the precursor film. A solvent-controlled growth (SCG) strategy of the precursor film is adopted, that is, inducing the solvent volatilization of the precursor film before high-temperature annealing. It is found that the solvent distribution of the precursor film is the key to the growth kinetics of perovskite films. The vacuum pretreated precursor film can obtain a dense buried interface to avoid the generation of small grains and pores at the interfaces of the perovskite/electron transport layer after high temperature crystallization. After passivation, non-radiative recombination in CsPbI2Br films is suppressed, accompanied by favorable carrier separation and extraction at the interface. The power conversion efficiency of all-inorganic CsPbI2Br carbon-based PSCs without a hole transport layer reaches 13.46%. The SCG strategy on the precursor films provides a way to passivate the buried interface of PSCs.
Optical properties and electronic structures of intrinsic gapped metals: Inverse materials design principles for transparent conductors
Authors: Khan Muhammad Rizwan , Gopidi Harshan Reddy , Malyi Oleksandr I.
Published: August 2023

Traditional solid-state physics has long correlated the optical properties of materials with their electronic structures. However, recent discoveries of intrinsic gapped metals have challenged this classical view. Gapped metals possess electronic properties distinct from both metals and insulators, with a large concentration of free carriers without any intentional doping and an internal bandgap. This unique electronic structure makes gapped metals potentially superior to materials designed by intentional doping of the wide bandgap insulators. Despite their promising applications, such as transparent conductors, designing gapped metals for specific purposes remains challenging due to the lack of understanding of the correlation between their electronic band structures and optical properties. This study focuses on representative examples of gapped metals and demonstrates the cases of (i) gapped metals (e.g., CaN2) with strong intraband absorption in the visible range, (ii) gapped metals (e.g., SrNbO3) with strong interband absorption in the visible range, and (iii) gapped metals (e.g., Sr5Nb5O17) that are potential transparent conductors. We explore the complexity of identifying potential gapped metals for transparent conductors and propose inverse materials design principles for discovering next-generation transparent conductors.
Effect of static electric fields on liquid water, its structure, dynamics, and hydrogen bond asymmetry: A molecular dynamics simulation study of TIP4P/2005 water model
Authors: Prasad Mahabir , English Niall J. , Chakraborty Somendra Nath
Published: August 2023

We study the effect of static electric fields of 0.1, 0.4, and 1.0 V/nm on the hydrogen bond structure and dynamics of TIP4P/2005 water at 1 bar and at temperatures between 300 and 200 K using molecular dynamics simulations. At all these temperatures, simulating liquid water with electric fields of 0.1 and 0.4 V/nm has no additional effect on its structural and dynamical changes, which otherwise already take place due to cooling. However, the introduction of 1.0 V/nm field enhances the slowing down of liquid water dynamics, crystallizes it to cubic ice at 240 and 220 K, and amorphizes it at 200 K. At 240 and 220 K, crystallization occurs within 5 and 50 ns, respectively. An electric field of 1 V/nm increases the relaxation times in addition to what cooling does. We note that when liquid water’s metastability limit is reached, crystallization is averted and amorphization takes place. Both equilibrium (liquid–solid) and non-equilibrium (liquid–amorphous) transformations are observed at 1 V/nm. Moreover, with an increase in the electric field, H-bonds become stronger. However, the donor–acceptor asymmetry (the difference between the strengths of two donor/acceptor bonds) remains even when crystallization or amorphization takes place. At low temperatures, increasing electric fields on liquid water increases both its crystallization and amorphization tendencies.
Preparation of thin-film SOI wafer by low-dose ion implantation
Authors: Zhang Yuhang , Sun Chenguang , Zhang Hui , Xie Luxiao , Liu Heyan , Chen Guifeng
Published: August 2023

Silicon-on-insulator (SOI) devices have many advantages, such as high speed, low energy consumption, radiation-hard, and high integration. In this paper, the separation by implanted oxygen process under low-dose implantation conditions is studied by the two-step implantation method combined with the internal thermal oxidation process. The effects of different types of silicon wafers and different implantation doses on SOI surface defects, top Si thickness, buried oxide (BOX) layer thickness, BOX layer breakdown voltage, and top Si defect density were investigated. Ultra-thin SOI wafers are prepared by epitaxial silicon wafers and control the first implantation dose. The number of surface defects of SOI materials is less than 100 counts, the breakdown voltage of the BOX layer is about 7.8 MV/cm, and the top Si dislocation density is about 8 × 103 cm−2.
Enhanced carrier management and photogenerated charge dynamics for selenium (Se) film photovoltaics
Authors: Liu Xinsheng , Duan Kaiyao , Ma Zhaohua , Tian Xingyuan , Li Fumin , Liang Siyang , Qin Chaoran , Liu Xiangyang
Published: August 2023

Although power conversion efficiency (PCE) of selenium (Se) solar cells has been improved, the device performance is capped by unexpected open-circuit voltage(VOC), short-circuit current (JSC), and fill factor (FF). The Se solar cells with tin oxide (SnO2) as the n-type buffer layer (NBL) have been reported. Here, the polyacrylic acid with carboxylic functional groups was added into the Alfa-SnO2 colloid to impede SnO2 aggregation during spin-coating. The superior Alfa-SnO2 film compactness with improved film coverage can enhance carrier management. The decreased conduction band offset at NBL/Se can promote rapid carrier injection from Se to Alfa-SnO2. Furthermore, the electrostatic attraction between carboxylic groups and Se atoms will passivate interface defects and promote charge extraction. The increased external quantum efficiency with high photovoltaic parameters (VOC, JSC, and FF) will evidently improve the device performance. Ultimately, a high PCE of 5.82% (a VOC of 0.870 V, a JSC of 10.77 mA cm−2, and a FF of 0.621) for the best-performing Se solar cells is achieved. Also, the photogenerated carrier separation, transport, and extraction processes have also been measured to determine the charge dynamics. The conformal P-Alfa-SnO2 films can largely enhance the light-harvesting performance, and the colloidal Alfa-SnO2 will open up a simple and effective way for improving device performance of Se solar cells.
Normalized solutions to the mass supercritical Kirchhoff-type equation with non-trapping potential
Authors: Rong Ting , Li Fuyi
Published: August 2023

This paper is concerned with the existence of solutions to the Kirchhoff-type equation −a+b∫R3|∇u|2Δu+(V+λ)u=|u|p−2u+μ|u|q−2uinR3 under the normalized constraint ∫R3u2=ρ2, where a, b, ρ > 0, 14/3 < q < p ⩽ 6, μ > 0 is a constant, and λ∈R appears as a Lagrange multiplier. Under an explicit assumption on V, we can prove the existence of positive ground state solutions to the above equation. A new concentration compactness type result is established to recover compactness in the Sobolev critical case.
Evolution of spin Hall mechanism and spin–orbit torque in (
α
,
β
) phase tantalum film
Authors: Xie Nian , Fan Weijia , Tang Meng , Pan Chang , Zhu Wei , Zhou Shiming , Qiu Xuepeng
Published: August 2023

We investigate the spin Hall mechanism and spin–orbit torque (SOT) efficiency in Ta/CoFeB/MgO heterostructures with varying Ta crystalline phases. The Ta crystalline phase, specifically (α + β) mixed phase and β phase, is achieved by controlling the sputtering power (PTa) during Ta deposition. We observe a negative temperature coefficient of resistivity for Ta deposited at PTa ≥ 40 W, which corresponds to the β phase of Ta. Our phenomenological scaling law analysis reveals a significant contribution of skew scattering to the spin Hall effect (SHE) in β phase Ta. Furthermore, we conduct a comprehensive comparison of the critical switching current density of Ta (JCTa) and power consumption between (α + β) Ta and β Ta phases. Despite β Ta exhibiting higher resistivity, its power consumption remains lower than that of (α + β) Ta phase, suggesting that β Ta is a superior spin–orbit material. Our findings serve as a valuable reference for manipulating SOT and SHE mechanisms through crystalline phase engineering.
Recurrence plots bridge deterministic systems and stochastic systems topologically and measure-theoretically
Authors: Hirata Yoshito , Shiro Masanori
Published: August 2023

We connect a common conventional value to quantify a recurrence plot with its motifs, which have recently been termed “recurrence triangles.” The common practical value we focus on is DET, which is the ratio of the points forming diagonal line segments of length 2 or longer within a recurrence plot. As a topological value, we use different recurrence triangles defined previously. As a measure-theoretic value, we define the typical recurrence triangle frequency dimension, which generally fluctuates around 1 when the underlying dynamics are governed by deterministic chaos. By contrast, the dimension becomes higher than 1 for a purely stochastic system. Additionally, the typical recurrence triangle frequency dimension correlates most precisely with DET among the above quantities. Our results show that (i) the common practice of using DET could be partly theoretically supported using recurrence triangles, and (ii) the variety of recurrence triangles behaves more consistently for identifying the strength of stochasticity for the underlying dynamics. The results in this study should be useful in checking basic properties for modeling a given time series.
Research on prediction of critical pressure of FGM cylindrical shells under hydrostatic pressure based on homogenization transformation method
Authors: Liu Xiao Min , Yang Meng , Li Rong , Liang Bin
Published: August 2023

This study uses the classical Flügge shell theory and homogenization transformation method to predict the critical pressure of functionally graded material (FGM) cylindrical shells under hydrostatic pressure. The method considers the similarity in physical properties and mechanical behavior between FGM and uniform materials. The vibration equation of the coupled system of an underwater FGM cylindrical shells is derived using the wave method, taking into account the influence of fluids. The natural frequency of the FGM cylindrical shell under hydrostatic pressure is obtained using the Newton iteration method. Based on the linear correlation between critical load and load level with zero natural frequency, the fitting curve method and the formula method after homogenization transformation are used to predict and analyze the critical pressure of FGM cylindrical shells under hydrostatic pressure. The effects of various parameters on the critical pressure are discussed. The results show that the material elastic modulus E, geometric dimensions h/R and L/R of FGM cylindrical shells, and different boundary conditions have a significant impact on the critical pressure. Through multiple comparative analyses of examples, the correctness and effectiveness of the proposed method are verified. The method has high prediction accuracy and low computational cost, providing a new exploration path for the analysis of non-uniform structural mechanical behavior.
N-representability violations in truncated equation-of-motion coupled-cluster methods
Authors: Yuwono Stephen H. , DePrince A. Eugene
Published: August 2023

One-electron reduced density matrices (1RDMs) from equation-of-motion (EOM) coupled-cluster with single and double excitations (CCSD) calculations are analyzed to assess their N-representability (i.e., whether they are derivable from a physical N-electron state). We identify EOM-CCSD stationary states whose 1RDMs violate either ensemble-state N-representability conditions or pure-state conditions known as generalized Pauli constraints. As such, these 1RDMs do not correspond to any physical N-electron state. Unphysical states are also encountered in the course of time-dependent EOM-CC simulations; when an external field drives transitions between a pair of stationary states with pure-state N-representable 1RDMs, the 1RDM of the time-dependent state can violate ensemble-state conditions. These observations point to potential challenges in interpreting the results of time-dependent EOM-CCSD simulations.
Excitonic interactions and Stark fluorescence spectra
Authors: Novoderezhkin Vladimir I.
Published: August 2023

We develop the theory for the Stark fluorescence (SF) of molecular aggregates by taking into account the mixing of the excited states [including the states with charge-transfer (CT) characters]. We use the sum-over-state approach and modified rotating wave approximation to describe interactions of the static and optical fields with the permanent and transition dipoles of the excited states. The SF spectral profiles are calculated using the standard and modified Redfield theories for the emission lineshapes. The resulting expression allows an interpretation of the SF response based on the calculation of only one-exciton states (i.e., the calculation of two-exciton states is not needed). The shape and amplitude of the SF spectrum can exhibit dramatic changes in the presence of the CT states, especially when the CT state is mixed with the red-most emitting exciton levels. In this case, the SF responses are much more sensitive to the exciton-CT mixing as compared with the usual Stark absorption. The limitation of the proposed theory is related to the simplified nature of the Redfield picture, which neglects the dynamic localization within the mixed exciton-CT configuration.
Engineering the electro-optic effect in HfO2 and ZrO2 through strain and polarization control
Authors: Delodovici Francesco , Atkinson Cassidy , Xu Ran , Janolin Pierre-Eymeric , Alpay S. Pamir , Paillard Charles
Published: August 2023

The ability to control the optical properties of a material with an electric field has led to optical memory devices, communication systems, optical signal processing, or quantum cryptography. Understanding electro-optic effects, especially in thin films, would improve the efficiency of these applications. In particular, the influence of epitaxial strains is of prime importance. In addition, the active control of these effects would be of great interest to tailor the material to the desired performance. Here, we demonstrate through first-principle calculations that the linear electro-optic response (Pockels effect) of two silicon-compatible ferroelectrics is stable with respect to bi-axial strain and that the electro-optic response can be strongly enhanced through the electrical control of the polarization. We attribute the former to the lack of optical phonon softening and a weak elasto-optic response and the latter to the externally induced softening of a phonon of symmetry A1. Our results are readily applicable to other polar materials and show that the electro-optic effect can be efficiently engineered to meet the performance criteria of future technologies.
Atomic layer etching (ALE) of III-nitrides
Authors: Ho Wan Ying , Chow Yi Chao , Biegler Zachary , Qwah Kai Shek , Tak Tanay , Wissel-Garcia Ashley , Liu Iris , Wu Feng , Nakamura Shuji , Speck James S.
Published: August 2023

Atomic layer etching (ALE) was performed on (Al, In, Ga)N thin films using a cyclic process of alternating Cl2 gas absorption and Ar+ ion bombardment in an inductively coupled plasma etcher system. The etch damage was characterized by comparing photoluminescence of blue single quantum well light-emitting diodes before and after the etch as well as bulk resistivities of etched p-doped layers. It was found that etched surfaces were smooth and highly conformal, retaining the step-terrace features of the as-grown surface, thus realizing ALE. Longer exposures to the dry etching increased the bulk resistivity of etched surfaces layers slightly, with a damaged depth of ∼55 nm. With further optimization and damage recovery, ALE is a promising candidate for controlled etching with atomic accuracy. It was found that Al0.1Ga0.9N acts as an etch barrier for the ALE etch, making it a suitable etch to reveal buried V-defects in III-nitride light emitting diodes.
Mechanical characterization of osteoporosis based on x-ray induced acoustic computed tomography
Authors: Hu Yang , Zhang Xingchao , Su Ningning , Shi Xiaohan , Chen Jiahui , Wu Hui , Liu Guoqing , Li Liming , Bai Caixun , Xiu Junshan , Zhao Yue
Published: August 2023

X-ray induced acoustic computed tomography (XACT) utilized the ultrasound generated by the thermoelastic effect to reconstruct the x-ray absorption distribution of tissues. In this Letter, we propose a method for mechanical characterization of osteoporosis based on an XACT technique. The theoretical and simulation studies were performed on the influence of elasticity effect on x-ray induced acoustic (XA) generation. The images of normal and osteoporotic bones reconstructed by the simulated XACT were found to be in good agreement with micro-CT. Furthermore, through XA signal analysis, the rise time of tissue displacement can be obtained to characterize the elasticity of bone tissues. Experimental results demonstrated that this method can provide structural and mechanical information of bone tissues, which has future potentials for assessment of bone in osteoporosis.
Investigation into a perfect matching between fracture transfer performance and vertical well productivity based on multi-scale and total factor characteristic models
Authors: Deng Jia , He Jiujiu , Zhang Lan , Chen Jingang , Song Hongqing , Gao Li
Published: August 2023

In fractured tight gas reservoirs, complex hydraulically induced fracture networks determine fluid flowing abilities of reservoirs. Thus, characterizing the complex fracture networks and revealing fracture transfer performances become a challenging work because of fracture branching, bending, and reversing in fractured reservoirs. In this paper, a fractal-like tree-shaped fracture model for gas transfer is proposed to optimize flow conductivity, pressure distribution at fracture intersection points, and flow transfer in such a complex fracture network considering the multi-scale effect, and total factor characteristics, including the length ratio, width ratio, branching angle, and branching level. The model is implemented to conduct validation against the experiment data in the literature. Subsequently, applying the proposed fracture model, the productivity equation for a vertical gas well intercepted by the fractal-like tree-shaped fracture network is further formulated. In addition, the good match with productivity simulation validates the accuracy of the developed productivity model for a vertical gas well. As a result, the impacts of the Knudsen number, fracture total factor characteristics, reservoir parameters, etc. on fracture transfer performances and well productivity are examined using the two proposed models. The results demonstrate that optimum fracture transfer performances do not match with the maximum well productivity. In contrast, the well productivity is jointly determined by both inlet flow volume of the fracture network and matrix permeability. Hence, a new formula considering both fracture characteristics and reservoir properties is proposed to match with the optimum fracture total length and maximum well productivity, thereby contributing to high-efficient and economic exploration of tight gas reservoirs.