bluuebunny/crossref_metadata_2025 huggingface dataset:
Porous bioelectronic substrates for simple electrochemical conjugation and subsequent, controlled electrochemical release of antisense oligonucleotide drug
Authors: Beikzadeh Sara , Bryant Devon T. , Akbarinejad Alireza , Pilkington Lisa I. , Phillips Anthony R. J. , Travas-Sejdic Jadranka
Published: August 2023

Electrochemically-driven terpolymer, P(EDOT-co-EDOTSAc-co-EDOTEG), offers rapid and controllable connexin43 antisense conjugation and release.
Size-dependent activity of carbon dots for photocatalytic H2 generation in combination with a molecular Ni cocatalyst
Authors: Casadevall Carla , Lage Ava , Mu Manting , Greer Heather F. , Antón-García Daniel , Butt Julea N. , Jeuken Lars J. C. , Watson Graeme W. , García-Melchor Max , Reisner Erwin
Published: August 2023

We demonstrate that purification and size separation of polydisperse carbon dot materials unveils the real active nanoparticles and enhances the photocatalytic H2 evolution using monodisperse carbon dots.
The technology of wearable flexible textile-based strain sensors for monitoring multiple human motions: construction, patterning and performance
Authors: Liza Liza , Kabir Md Homaune , Jiang Liang , Jerrams Stephen , Chen Shaojuan
Published: August 2023

This paper discusses the development of wearable flexible textile-based strain sensors for monitoring multiple human motions.
Direct numerical simulations of a microswimmer in a viscoelastic fluid
Authors: Kobayashi Takuya , Jung Gerhard , Matsuoka Yuki , Nakayama Yasuya , Molina John J. , Yamamoto Ryoichi
Published: August 2023

We extend the SP method to study the dynamics of squirming and swirling particles in viscoelastic fluids, in order to elucidate the mechanism behind their swimming speed enhancement.
Maximum principle for partially observed leader–follower stochastic differential game
Authors: Li Ruijing , Ma Heping , Hu Chaozhu
Published: August 2023

This paper deals with the optimal control problem for partially observed leader–follower stochastic differential game. By virtue of the classical variational method and Girsanov's theorem, the stochastic maximum principles for the follower under one type of partially observed case and for the leader under the complete information structure are derived. As applications, two partially observed cases are considered for the linear–quadratic models. Then by the stochastic filtering technique, the optimal feedback controls for the follower and the leader are represented by the new stochastic Riccati equations.
Optimal allocation of photovoltaic generations in buildings‐to‐distribution‐network integration system using improved backtracking search optimization algorithm
Authors: Tang Wenhu , Huang Kecan , Zhang Yin , Qian Tong
Published: August 2023

A novel optimal allocation framework for photovoltaic generations in an integration system of buildings‐to‐distribution‐network using improved backtracking search optimization algorithm is proposed here. In the proposed framework, photovoltaic generations are optimally allocated to optimize the overall performance of a buildings‐to‐distribution‐network regarding the efficient active power usage of photovoltaic generations, the energy savings, and voltage profile improvement of distribution network. The effects of building active demand response on the photovoltaic generations' optimal allocation are considered in the proposed framework. An improved backtracking search algorithm using two new operators is developed to optimize the active power reduction factors and locations of photovoltaic generations. The test results of IEEE 33‐bus and 69‐bus systems demonstrate that the developed framework can take full advantage of photovoltaic generation power and the active demand response of buildings to coordinate the efficient active power usage of photovoltaic generations, the voltage profile improvement and energy savings of a buildings‐to‐distribution‐network. In addition, the improved backtracking search optimization algorithm converges faster than genetic algorithm, classical backtracking search optimization algorithm, and bird swarm algorithm.
Inferring the presence of very massive stars in local star-forming regions
Authors: Martins F. , Schaerer D. , Marques-Chaves R. , Upadhyaya A.
Published: August 2023

Context. Very massive stars (VMS) have masses in excess of 100 M⊙ and are rare. However, owing to their powerful winds, very high luminosity, and efficient nucleosynthesis, they are key players of star-forming regions. In particular, their strong ionizing fluxes impact the surrounding interstellar medium.

Aims. We aim at detecting VMS in local star-forming region from the imprint they leave on the integrated UV and optical light.

Methods. We analyzed a sample of 27 star-forming regions and galaxies in the local Universe. We selected sources with a metallicity close to 12+log(O/H) = 8.3, which is typical of the Large Magellanic Cloud. We defined empirical criteria to distinguish sources dominated by VMS and Wolf-Rayet stars (WR), using template spectra of VMS- and WR-dominated regions. We subsequently built population synthesis models with an updated treatment of VMS. We investigated the successes and failures of these new models in accounting for the UV-optical spectroscopy of our sample sources.

Results. We show that the UV range alone is not sufficient to distinguish between VMS- and WR-dominated sources because their spectra are almost identical in this range. The region of the WR bumps in the optical breaks the degeneracy. In particular, the morphology of the blue bump at 4640–4686 Å is a key diagnostic. Beyond the prototypical R136 region, which contains VMS, we identify two galaxies showing clear signatures of VMS. In two other galaxies or regions the presence of VMS can be suspected, as already discussed in the literature. The stellar population is clearly dominated by WR stars in seven other sources. The most recent BPASS population synthesis models can neither account for the strong He II 1640 emission, nor for the shape of the blue bump in VMS- and WR-dominated sources. Our models that include VMS more realistically reproduce the UV-optical spectra of VMS-dominated sources.

Conclusions. We conclude that VMS are present in some local star-forming regions, but that separating them from WR-dominated populations requires optical spectroscopy with a high signal-to-noise ratio. A high equivalent width of He II 1640 is not a sufficient condition for identifying VMS. Populations synthesis models need to take VMS into account by incorporating not only evolutionary tracks, but also dedicated spectral libraries. Finally, we stress that the treatment of WR stars needs to be improved as well.
HYPerluminous quasars at the Epoch of ReionizatION (HYPERION): A new regime for the X-ray nuclear properties of the first quasars
Authors: Zappacosta L. , Piconcelli E. , Fiore F. , Saccheo I. , Valiante R. , Vignali C. , Vito F. , Volonteri M. , Bischetti M. , Comastri A. , Done C. , Elvis M. , Giallongo E. , La Franca F. , Lanzuisi G. , Laurenti M. , Miniutti G. , Bongiorno A. , Brusa M. , Civano F. , Carniani S. , D’Odorico V. , Feruglio C. , Gallerani S. , Gilli R. , Grazian A. , Guainazzi M. , Marinucci A. , Menci N. , Middei R. , Nicastro F. , Puccetti S. , Tombesi F. , Tortosa A. , Testa V. , Vietri G. , Cristiani S. , Haardt F. , Maiolino R. , Schneider R. , Tripodi R. , Vallini L. , Vanzella E.
Published: August 2023

The existence of luminous quasars (QSOs) at the epoch of reionization (EoR; i.e., z > 6) powered by well-grown supermassive black holes (SMBHs) with masses ≳109 M⊙ challenges models of early SMBH formation and growth. To shed light on the nature of these sources, we started a multiwavelength program based on a sample of 18 HYPerluminous quasars at the Epoch of ReionizatION (HYPERION). These are the luminous QSOs whose SMBHs must have had the most rapid mass growth during the first gigayear of the Universe and therefore acquired the largest mass at their respective epochs. In this paper, we present the HYPERION sample and report results from the first year of the planned three years of observations of the 2.4 Ms XMM-Newton Multi-Year Heritage program on which HYPERION is based. The goal of this program is to accurately characterise the X-ray nuclear properties of QSOs at the EoR. Through a joint X-ray spectral analysis of ten sources, covering the rest-frame ∼2 − 50 keV energy range, we report a steep average photon index (Γ ≈ 2.4 ± 0.1). No absorption is required at levels of 1021 − 1022 cm−2. The measured average Γ is inconsistent at ≥4σ level with the canonical value (Γ = 1.8 − 2) measured in QSOs at z < 6. Such a steep spectral slope is also significantly steeper than that reported in lower-z analog QSOs with similar luminosity or accretion rate, suggesting genuine redshift evolution. Alternatively, we can interpret this result as suggesting the presence of a very low energy cutoff Ecut ≈ 20 keV on a standard Γ = 1.9 power-law, the likes of which is rarely reported at lower z. We also report mild indications that, on average, HYPERION QSOs show higher levels of coronal soft X-rays at 2 keV compared to the accretion disk UV at 2500 Å than expected for lower-z AGN in the high-luminosity regime. We speculate that either a redshift-dependent coupling between the X-ray corona and accretion disk or intrinsically different coronal properties account for the steepness of the X-ray spectral slope, especially in the presence of powerful winds. The reported steep slopes, if confirmed in lower-luminosity regimes, may have an important impact on the design of next-generation X-ray facilities and future surveys designed to investigate the early Universe.
Post-COVID-Syndrom: Interaktion von Fatigue, Schlafstörungen und Immunsystem
Authors: Schilling Claudia , Koerner-Rettberg Cordula
Published: August 2023

„Genesen, aber nicht gesund“ – das ist die Situation, in der sich etwa 10–15 % der Menschen nach einer COVID-19-Erkrankung befinden. Das Hauptsymptom besteht in einer oft sehr beeinträchtigenden Fatigue. Die subjektive Natur dieses Symptoms und das unvollständige Verständnis von dessen Pathogenese lassen es teils schwer fassbar erscheinen. Dennoch haben wir inzwischen viel über mögliche zugrundeliegende Krankheitsmechanismen gelernt.
eHealth für MS-Betroffene mit Fatigue
Authors: Pöttgen Jana , Penner Iris-Katharina
Published: August 2023

„Kurz nachdem ich morgens aufgestanden bin, könnte ich mich eigentlich schon wieder hinlegen.“ Solche und ähnliche Sätze machen den Alltag von Menschen mit MS-Fatigue deutlich. Darauf zu antworten mit „Das kenne ich, geht mir manchmal genauso.“ zeigt, dass wir Gesunde nicht annähernd eine Vorstellung davon haben, was Fatigue wirklich bedeutet. Digitale Therapieangebote geben Betroffenen neue Hoffnung – zumindest auf Linderung der Symptomatik.
Chronic Hepatitis B In Children: Case Series From A Tertiary
Paediatric Hospital
Authors: Zirek Fazilcan , Hosnut Ferda Ozbay , Sahin Gulseren , Senel Saliha
Published: August 2023

Background Chronic hepatitis B (CHB) remains an important global public
health problem. Seroconversion is highly correlated with favourable long-term
outcome. There is no consensus on the treatment method, onset time and duration
for paediatric CHB patients. In this study, we aimed to evaluate the course of
children with CHB, to determine the characteristics of the patients who
developed spontaneous seroconversion and treatment indications, and to compare
the effectiveness of different treatment modalities.

Patients and Methods Patients aged 1–18 years with a diagnosis of
CHB were included in this study and evaluated for the development of spontaneous
hepatitis B envelope antigen (HBeAg)/surface antigen (HBsAg)
seroconversion and treatment modalities. The treated patients were divided into
two groups according to their treatment regimen.

Results Of the 114 patients, the median age at diagnosis was 8.4 years and
median follow-up period was 5.2 years. Spontaneous HBeAg and HBsAg
seroconversion developed in 18 (20.6%) of 87 HBeAg positive patients and
two (1.8%) patients, respectively. Thirty-one patients were treated. The
follow-up period was higher in the group with HBeAg seroconversion (p:0.005).
There was no statistical difference between the patients in terms of
seroconversion development and treatment status. The serum alanine
aminotransferase (ALT) values at the time of diagnosis were statistically higher
in treated patients.

Conclusion HBV infection and CHB continue to be an important problem for
children in our country. Consensus on the appropriate ALT ULN is needed for the
treatment of hepatitis in children.
Capsule endoscopy with artificial intelligence-assisted technology: Real-world usage of a validated AI model for capsule image review
Authors: O'Hara Fintan John , Mc Namara Deirdre
Published: August 2023

Background and study aims Capsule endoscopy is a time-consuming procedure with a significance error rate. Artificial intelligence (AI) can potentially reduce reading time significantly by reducing the number of images that need human review. An OMOM Artificial Intelligence-enabled small bowel capsule has been recently trained and validated for small bowel capsule endoscopy video review. This study aimed to assess its performance in a real-world setting in comparison with standard reading methods.

Patients and methods In this single-center retrospective study, 40 patient studies performed using the OMOM capsule were analyzed first with standard reading methods and later using AI-assisted reading. Reading time, pathology identified, intestinal landmark identification and bowel preparation assessment (Brotz Score) were compared.

Results Overall diagnosis correlated 100% between the two reading methods. In a per-lesion analysis, 1293 images of significant lesions were identified combining standard and AI-assisted reading methods. AI-assisted reading captured 1268 (98.1%, 95% CI 97.15–98.7) of these findings while standard reading mode captured 1114 (86.2%, 95% confidence interval 84.2–87.9), P < 0.001. Mean reading time went from 29.7 minutes with standard reading to 2.3 minutes with AI-assisted reading (P < 0.001), for an average time saving of 27.4 minutes per study. Time of first cecal image showed a wide discrepancy between AI and standard reading of 99.2 minutes (r = 0.085, P = 0.68). Bowel cleansing evaluation agreed in 97.4% (r = 0.805 P < 0.001).

Conclusions AI-assisted reading has shown significant time savings without reducing sensitivity in this study. Limitations remain in the evaluation of other indicators.
The Bethesda ERCP Skills Assessment Tool (BESAT) can reliably differentiate endoscopists of different experience levels
Authors: Liu Kevin , Elmunzer B. Joseph , Wani Sachin , Taft Tiffany , Walsh Catharine M , Arain Mustafa A , Berzin Tyler M. , Buxbaum James , DiMaio Christopher , Fehmi Syed M. Abbas , Gupta Neil , Jonnalagadda Sreenivasa , Kushnir Vladimir , Maple John T. , Muthusamy Raman , Rastogi Amit , Shah Janak N , Chak Amitabh , Faulx Ashley , Forbes Nauzer , Keswani Rajesh N
Published: August 2023

Background and study aims The Bethesda ERCP Skill Assessment Tool (BESAT) is a video-based assessment tool of technical endoscopic retrograde cholangiopancreatography (ERCP) skill with previously established validity evidence. We aimed to assess the discriminative validity of the BESAT in differentiating ERCP skill levels.

Methods Twelve experienced ERCP practitioners from tertiary academic centers were asked to blindly rate 43 ERCP videos using the BESAT. ERCP videos consisted of native biliary cannulation and sphincterotomy and were recorded from 10 unique endoscopists of various ERCP experience (from advanced endoscopy fellow to > 10 years of ERCP experience). Inter-rater reliability, discriminative validity, and internal structure validity were subsequently assessed.

Results The BESAT was found to reliably differentiate between endoscopists of varying levels of ERCP experience with experienced ERCPists scoring higher than novice ERCPists in 11 of 13 (85%) instrument items. Inter-rater reliability for BESAT items ranged from good to excellent (intraclass correlation range: 0.86 to 0.93). Internal structure validity was assessed with item-total correlations ranging from 0.53 to 0.83.

Conclusions Study findings demonstrate that the BESAT, a video-based ERCP skill assessment tool, has high inter-rater reliability and has discriminative validity in differentiating novice from expert ERCP skill. Further investigations are needed to determine the role of video-based assessment in improving trainee learning curves and patient outcomes.
Sociodemographic Factors and Intestinal Microbiome Development in Preterm, Very Low Birth Weight Infants
Authors: Desorcy-Scherer Katelyn , Lamberti Monica F. Torrez , Weaver Michael , Lorca Graciela L. , Parker Leslie A.
Published: August 2023

Objective Preterm very low birth weight (VLBW) infants are at risk for intestinal morbidities and dysbiotic development of the intestinal microbiome. Despite the influence of sociodemographic factors on premature infant health outcomes, whether they shape the intestinal microbiome early in life is not clear. The objective was to explore the associations between race, sex, and socioeconomic status and the intestinal microbiome of VLBW infants during the first 4 weeks of life.

Study Design This was a secondary analysis of data from an ongoing randomized trial of 79 infants ≤30 weeks' gestation and ≤1,500 g. Stool samples were collected at week 1 through week 4, frozen to −80°C and analyzed by 16S rRNA sequencing of the V4 region using Illumina MiSeq. Reads were analyzed to measure α and β diversity as well as relative abundance of bacteria in the intestinal microbiome.

Results Of the 79 infants, 63 had at least one sample available. Twenty-three (37%) of infants were African American, 30 (48%) were male, and 44 (71%) had Medicaid insurance. There were no statistically significant (<0.05) differences in α diversity or β diversity, and the differential abundance analysis suggests limited patterns of distinction in the intestinal microbiome between non-African American and African American infants, male and female infants, and infants with maternal private or Medicaid insurance.

Conclusion Our results suggest race, sex, and socioeconomic status shape colonization of specific microorganisms to a limited extent. Future studies should confirm these findings and determine clinical relevance through further study of differentially abundant microorganisms and additional factors contributing to colonization patterns.

Key Points
Detecting Oxygenator Thrombosis in ECMO: A Review of Current Techniques and an Exploration of Future Directions
Authors: Leerson Jack , Tulloh Andrew , Lopez Francisco Tovar , Gregory Shaun , Buscher Hergen , Rosengarten Gary
Published: August 2023

Extracorporeal membrane oxygenation (ECMO) is a life-support technique used to treat cardiac and pulmonary failure, including severe cases of COVID-19 (coronavirus disease 2019) involving acute respiratory distress syndrome. Blood clot formation in the circuit is one of the most common complications in ECMO, having potentially harmful and even fatal consequences. It is therefore essential to regularly monitor for clots within the circuit and take appropriate measures to prevent or treat them. A review of the various methods used by hospital units for detecting blood clots is presented. The benefits and limitations of each method are discussed, specifically concerning detecting blood clots in the oxygenator, as it is concluded that this is the most critical and challenging ECMO component to assess. We investigate the feasibility of solutions proposed in the surrounding literature and explore two areas that hold promise for future research: the analysis of small-scale pressure fluctuations in the circuit, and real-time imaging of the oxygenator. It is concluded that the current methods of detecting blood clots cannot reliably predict clot volume, and their inability to predict clot location puts patients at risk of thromboembolism. It is posited that a more in-depth analysis of pressure readings using machine learning could better provide this information, and that purpose-built imaging could allow for accurate, real-time clotting analysis in ECMO components.
Metastasis of maxillary sinus adenoid cystic carcinoma to the humerus bone—A rare case report
Authors: Sagar Mala , Singh Anurag , Qayoom Sumairya , Singh U. S.
Published: August 2023

Adenoid cystic carcinoma accounts for 10 to 12% of all salivary gland malignant neoplasms with an estimated incidence of 3 to 4.5 cases per million per year. Perineural spread and multiple local recurrences are its defining features, although the liver and lung are the most frequent sites for distant metastases. It is extremely uncommon for adenoid cystic carcinoma of the maxillary sinus to spread to distant bones. Few cases of adenoid cystic carcinoma with distant bone metastasis have been reported. Here, we report a known case of the adenoid cystic carcinoma of the maxillary sinus in a 40-yearold male, with isolated metastasis to the left humerus bone presenting 4 years later to the excision of the primary lesion. The fine-needle aspiration cytology, trucut biopsy, and immunocytochemistry of the left humerus osteoexpansile lesion confirmed the diagnosis of metastatic adenoid cystic carcinoma. This rare case report re-emphasizes the distant metastatic potential of adenoid cystic carcinoma.
Reconstruction Of Facial Defect In Cancrum Oris
Authors: Khan Prof. Masood H. , Khan Dr. Arshad Hafeez , Yaseen Dr. Mohd. , Bhat Dr. Farooq
Published: August 2023

Reconstruction of composite, massive tissue loss in 12 cases of cancrum oris is carried out. Three different flaps have been used and their merits are listed.
The Role of Single Dose Heparin in Prevention of Thrombus Formation in a New Experimental Thrombosis Model
Authors: Nanda V , Khazanchi R K , Rakshit K , Chopra P
Published: August 2023

Vascular thrombosis continues to remain a major problem in microvascular surgery. Various antithrombotic agents have been used in experimental models in order to study their influence on the incidence of thrombosis. A new microvascular thrombosis model which utilizes a crushing artery forceps on the rat femoral vessels was used to evaluate the effect of a single does of heparin administered subcutaneously just prior to release of the crushing clamp. Patency across the traumatized segments was determined after 24 hours, by the “milking” test and by dividing the vessels downstream to the site of trauma.

In the arterial model there was an increase in patency from 83% to 96% and that in the vein model, from 35% to 80% . The results suggest that single dose heparin significantly increases patency rate in veins, in the immediate and early postoperative period. The arterial thrombosis model was however insufficiently thrombogenic and needs further evaluation.
A System for Documentation of Cleft Lip and Nose Deformity and Postoperative Analysis
Authors: Agarwal Rajiv , Bhatnagar S K , Chandra Ramesh
Published: August 2023

A reliable system of documentation of the extent of deformity of the cleft lip, alveolus, palate and nose is essential to compare treatment methods and results of this common problem. We are presenting here a symbolic system of documenting preoperative deformity, intraoperative technique and postoperative status in cleft lip nose deformity which is based on previously published diagnosis and documentation systems. Modified striped Y system is used to document the extent of the deformity and this is combined with standard measurements for the cleft lip nose deformity and charts to document the intraoperative steps. We find this to be simple and reliable for the analysis of the results.
An Unusual Injury of the Hand in a Plastic Injection Moulding Machine
Authors: Aiyer Purnima M , Vij VK , Rana RE
Published: August 2023

Injuries in plastic moulding machines are not uncommon. Usually the hand is caught between the two parts of the closing mould in which the plastic product sets, resulting in severe crushing and avulsion of tissues. An unusual penetrating injury sustained in a plastic moulding machine is described.
The diminutive morphological function between English and Pashto languages: a comparative study
Authors: Khan Afzal
Published: August 2023

This study aimed to investigate the phenomenon of diminutive morphological function in terms of productivity, similarities, and differences in inflectional bound morphemes between English and Pashto, particularly in the categories of nouns and adjectives. The study also aims to examine the possible influence of ancient languages, such as Greek, on the diminutive morphological function and productivity of these two languages. It is generally assumed that languages descending from similar parental groups share the same diminutive function and productivity pattern in marking morphological mechanisms such as number, gender, and case. Different online sources, libraries, and publication papers were consulted to make a comparison between these two varieties. The findings revealed that both English and Pashto retain a morphological function, but English uses limited inflectional morphemes. Pashto, on the other hand, employs a wide range of suffixations, particularly in marking the diminutive aspect, and that differentiates it from English in semantic and pragmatic expressions. The findings aligned with the initial hypothesis developed that languages descending from similar parental groups use a similar pattern of morphological mechanisms. The only difference is that English drops the inflections to a greater extent because it underwent different phases of modifications, while Pashto still retains the inflections and, in turn, reveals greater productivity. Moreover, the findings disclosed that Pashto is closer to Greek in its inflectional nature and functioning of diminutives than English.
Measuring the impact of COVID-19 on heritage sites in the UK using social media data
Authors: Liu Ziwen , Orr Scott Allan , Kumar Pakhee , Grau-Bove Josep
Published: August 2023

The COVID-19 pandemic has had a profound impact on almost all aspects of society. Cultural heritage sites, which are deeply intertwined with the tourism industry, are no exception. The direct impacts of the virus on the population, as well as indirect impacts, such as government-mandated measures including social distancing, face coverings, and frequent temporary closures of sites, have greatly impacted visitor experiences at heritage sites. To quantitatively evaluate the impact of these measures from the perspective of visitors, we collected 1.4 millions visitor reviews from the Google Maps platform for 775 heritage sites. We analyzed visiting rates using the number of online reviews as a proxy and adopt state-of-the-art natural language processing techniques to more deeply understand visitor perception of preventive measures put in place to control the spread of COVID-19. Our findings reveal that even if visitor focus on COVID-19 has significantly decreased, there may still be notable difference between actual and expected number of reviews, suggesting that visitor involvement (e.g., number of visitors) for cultural heritage sites, especially urban indoor sites, needs more time to recover. Our findings further show that most comments by visitors to sites were associated with negative sentiment toward restricted access, but recognized the necessity of other safeguarding measures (e.g., social distancing and the requirement for face coverings). Moreover, they exhibited negative sentiment towards staff or other visitors who did not adhere to these measures. We make specific recommendations for heritage sites to adapt to the COVID-19 pandemic and a more general observation that the method used to gather information from online reviews in this paper will be effective in measuring visitor perceptions towards specific aspects of heritage sites, particularly in capturing changes in perception before and after unexpected or disruptive events at heritage sites.
New approach to KPZ models through free fermions at positive temperature
Authors: Imamura Takashi , Mucciconi Matteo , Sasamoto Tomohiro
Published: August 2023

We give a short account of our new approach to study models in the Kardar–Parisi–Zhang universality class by connecting them to free fermions at positive temperature. Our ideas and methods are explained mainly for the semi-discrete directed polymer model due to O’Connell and Yor.
Sub-nanosecond time-resolved radiation measurement using x-ray focusing crystal spectrometers
Authors: Elshafiey A. T. , Chalmers N. G. , Pikuz S. A. , Shelkovenko T. A. , Hammer D. A.
Published: August 2023

In this paper, we describe a technique using a crystal spectrometer, a silicon-diode detector, and a filtered photoconductive detector to monitor photon energies in the L-shell (0.9–1 keV) and K-shell regimes for nickel and copper hybrid X-pinch x-ray sources. The detectors, system cabling, and an 8 GHz digital oscilloscope in combination enable time resolution better than 200 ps for photoconductive detectors and 700 ps for silicon-diode detectors of the K- and L-shell radiation signals, respectively. We substantially improve the relative timing of signals obtained using the oscilloscope by using an x-ray streak camera with a crystal spectrometer to monitor the L-shell line spectra and, separately, the K-shell line spectra relative to the continuum burst to better than 17 ps time resolution. This combination of instruments enabled and validated a new method by which plasma conditions in nickel and copper X-pinches can be assessed immediately before and after the ∼30 ps continuum x-ray burst produced by 370 kA hybrid X-pinches. In general, the method described here can be applied to observe otherwise highly filter-absorbed radiation in the presence of a broad spectrum of higher energy radiation by combining x-ray crystals and detectors.
Tunable acoustic resonances: From weak to strong coupling regime
Authors: Günay Mehmet , Biçer Ahmet , Korozlu Nurettin , Cicek Ahmet
Published: August 2023

Tunable interaction strength between a side-coupled ring resonator and an acoustic waveguide structure is demonstrated. Fano resonances in the weak coupling regime are observed from the interference between a discrete state of the ring resonator and a continuum state of the waveguide. As the distance between the two structures is decreased, a transition from weak to strong coupling regime is obtained, where we observe splitting in the transmission spectrum and Rabi oscillations in the temporal behavior for smaller values. The findings of the finite-element method simulations are supported with the results obtained from a simple theoretical model in which one can explain the dynamics of the hybrid modes. The results can contribute to device applications in acoustic sensors, switches, and surface acoustic wave integrated circuits.
Anisotropic strain-modulated monoclinic phases with giant piezoelectricity in high-index-oriented PbTiO3 films
Authors: Fang Zhong , Guo Xiang-Wei , Zhang Heng , Wang Yu-Jia , Tang Yun-Long , Zhu Yin-Lian , Ma Xiu-Liang
Published: August 2023

By combining phase-field simulations and first-principles calculations, we proposed to modulate the monoclinic phases of high-index-oriented PbTiO3 films through epitaxial anisotropic strain to obtain superior piezoelectric performance. It was found that the piezoelectric coefficients e22 were remarkably enhanced (up to 2400%) in both (111)- and (110)-oriented PbTiO3 films. The excellent piezoelectric property is mainly attributed to the polarization rotation due to the flatter energy landscapes in the monoclinic phases, while the variation of polarization magnitude contributes little to piezoelectricity. Our research suggests modulating material properties through anisotropic strain, which might bring some insight to other functional materials.
Temperature activated chiral induced spin selectivity
Authors: Fransson J.
Published: August 2023

Recent experiments performed on chiral molecules, comprising transition metal or rare earth elements, indicate temperature reinforced chiral induced spin selectivity. In these compounds, spin selectivity is suppressed in the low temperature regime but grows by one to several orders of magnitude as the temperature is increased to room temperature. By relating temperature to nuclear motion, it is proposed that nuclear displacements acting on the local spin moments, through indirect exchange interactions, generate an anisotropic magnetic environment that is enhanced with temperature. The induced local anisotropy field serves as the origin of a strongly increased spin selectivity at elevated temperature.
Enhanced tunable terahertz Mie resonance and magnetoplasmonic effect through chain formation in ferrofluid
Authors: Wei Yi-An , Wu Pei-Jung , Tsai Po-Yu , Chen Kuen-Lin , Yang Chan-Shan
Published: August 2023

We present experimental and theoretical evidence demonstrating the Mie resonance effect in the terahertz (THz) range, utilizing Fe3O4/Kerosene ferrofluid. Our findings indicate a significant and rapid change in the complex refractive indices at 0.5 THz with an increase in the magnetic field strength. Moreover, we observed a prominent absorption peak at 0.5 THz in transmittance and absorption coefficient measurements, corresponding to a magnetic field intensity of 178.0 mT. This phenomenon occurs due to the adjustment of particle spacing, leading to resonance under different magnetic field conditions. These research results hold immense potential in advancing the development of magneto-optical THz modulators for imaging and communication applications.
Germanium wafers for strained quantum wells with low disorder
Authors: Stehouwer Lucas E. A. , Tosato Alberto , Degli Esposti Davide , Costa Davide , Veldhorst Menno , Sammak Amir , Scappucci Giordano
Published: August 2023

We grow strained Ge/SiGe heterostructures by reduced-pressure chemical vapor deposition on 100 mm Ge wafers. The use of Ge wafers as substrates for epitaxy enables high-quality Ge-rich SiGe strain-relaxed buffers with a threading dislocation density of (6±1)×105 cm−2, nearly an order of magnitude improvement compared to control strain-relaxed buffers on Si wafers. The associated reduction in short-range scattering allows for a drastic improvement of the disorder properties of the two-dimensional hole gas, measured in several Ge/SiGe heterostructure field-effect transistors. We measure an average low percolation density of (1.22±0.03)×1010 cm−2 and an average maximum mobility of (3.4±0.1)×106 cm2/Vs and quantum mobility of (8.4±0.5)×104 cm2/Vs when the hole density in the quantum well is saturated to (1.65±0.02)×1011 cm−2. We anticipate immediate application of these heterostructures for next-generation, higher-performance Ge spin-qubits, and their integration into larger quantum processors.
Superhydrophobicity of thermally annealed aluminum surfaces and its effect on corrosion resistance
Authors: Zhang Dejian , Wan Yong , Nagayama Gyoko
Published: August 2023

Surface functionalization with chemical modification, i.e., low surface energy coating, is the most commonly used method to obtain hydrophobic/superhydrophobic surfaces. However, the fabrication procedures are complex or harmful to environment, and the factors affecting corrosion resistance of chemically modified surfaces are difficult to determine owing to the complicated anticorrosive mechanism. In this study, a simple and environment-friendly method was employed to prepare hydrophobic/superhydrophobic surfaces without chemical modification. The electrochemical impedance method was applied to measure the corrosion resistances, and the effective wetting area was used to elucidate the anticorrosive mechanism of hydrophobic surfaces. We found that the corrosion resistances of the fabricated Al samples were closely correlated with the surface wettability and further related to the effective wetting area at the solid–liquid interface. Consequently, a smaller effective wetting area results in a larger corrosion resistance and thus enhances the corrosion protection performance.
State-specific frozen natural orbital for reduced-cost algebraic diagrammatic construction calculations: The application to ionization problem
Authors: Mukhopadhyay Tamoghna , Jangid Bhavnesh , Dutta Achintya Kumar
Published: August 2023

We have developed a reduced-cost algebraic diagrammatic construction (ADC) method based on state-specific frozen natural orbital and natural auxiliary functions. The newly developed method has been benchmarked on the GW100 test set for the ionization problem. The use of state-specific natural orbitals drastically reduces the size of the virtual space with a systematically controllable accuracy and offers a significant speedup over the standard ionization potential (IP)-ADC(3) method. The accuracy of the method can be controlled by two thresholds and nearly a black box to use. The inclusion of the perturbative correction significantly improves the accuracy of the calculated IP values, and the efficiency of the method has been demonstrated by calculating the IP of a molecule with 60 atoms and more than 2216 basis functions.
Study on hydrodynamic characteristics of a hybrid wind-wave energy system combing a composite bucket foundation and wave energy converter
Authors: Song Haoyang , Yu Tongshun , Shi Hongda , Wang Yuqiao , Zhang Zhenyu
Published: August 2023

In this paper, a new type of combined wind-wave system is proposed, that is, composite bucket foundation-oscillating buoy (CBF-OB) combined device. A three-dimensional numerical wave flume is established by using the renormalization group k–ε model. The hydrodynamic characteristics around the wave and the combined power generation device are studied. The relationship between wave parameters and wave run-up and wave pressure is analyzed. The absorption efficiency performance of the combined power generation device is evaluated. The results show that in the combined power generation system, the wave run-up and wave pressure at 0°–135° around the CBF are smaller than those in the presence of only CBF, but near 180° the ones are larger than those in the presence of only CBF. In the rear side of the combined power generation system, the smaller the scattering parameters, the more obvious the phenomenon of the second wave peak, and the stronger the nonlinearity of the wave and CBF-OB combined power generation system. The proposed CBF-OB combined power generation device can significantly improve the absorption efficiency of the buoy, which can be increased by about 1.5–4.0 times compared with the absorption efficiency under the action of only the buoy alone. There is an optimal power takeoff parameter, that is, when the damping parameter is 500 N·s/m, to maximize the absorption efficiency of the combined power generation device.
Modulated super-Gaussian laser pulse to populate a dark rovibrational state of acetylene
Authors: Aerts Antoine , Jolly Spencer W. , Kockaert Pascal , Gorza Simon-Pierre , Auwera Jean Vander , Vaeck Nathalie
Published: August 2023

A pulse-shaping technique in the mid-infrared spectral range based on pulses with a super-Gaussian temporal profile is considered for laser control. We show a realistic and efficient path to the population of a dark rovibrational state in acetylene (C2H2). The laser-induced dynamics in C2H2 are simulated using fully experimental structural parameters. Indeed, the rotation–vibration energy structure, including anharmonicities, is defined by the global spectroscopic Hamiltonian for the ground electronic state of C2H2 built from the extensive high-resolution spectroscopy studies on the molecule, transition dipole moments from intensities, and the effects of the (inelastic) collisions that are parameterized from line broadenings using the relaxation matrix [A. Aerts, J. Vander Auwera, and N. Vaeck, J. Chem. Phys. 154, 144308 (2021)]. The approach, based on an effective Hamiltonian, outperforms today’s ab initio computations both in terms of accuracy and computational cost for this class of molecules. With such accuracy, the Hamiltonian permits studying the inner mechanism of theoretical pulse shaping [A. Aerts et al., J. Chem. Phys. 156, 084302 (2022)] for laser quantum control. Here, the generated control pulse presents a number of interferences that take advantage of the control mechanism to populate the dark state. An experimental setup is proposed for in-laboratory investigation.
Activation of atomic transport via vibrational coupling-induced force fluctuations
Authors: Noh Yechan , Aluru N. R.
Published: August 2023

Vibrational coupling, although well-explored in many fields, has seldom been investigated in the context of mass transport. In this Letter, we examine the impact of vibrational coupling on atomic transport using simple molecular dynamics simulations. Our study shows that the atomic transport can be activated when the natural frequency of the atomic slit is close to the natural frequency of the atom being transported. We uncover the presence of fluctuating forces induced by vibrational coupling with higher amplitudes observed when the coupling is strong. We show that the transport activation mechanism is due to the high force fluctuations that arise during strong vibrational coupling allowing the atom to temporarily surpass the transport barrier of the slit. Our findings will serve as a foundation for the continued examination of vibrational coupling in the realm of mass transport.
Doping-induced facet transformation boosts water oxidation activity of cobalt carbonate hydroxide hydrate
Authors: Liu Xue-Ying , Bi Haohao , Li Lei , Li Bo , Wang Yu-Han , Shi Jinghui , Nie Jianhang , Huang Gui-Fang , Hu Wangyu , Huang Wei-Qing
Published: August 2023

Rational engineering of non-noble metal catalysts with exposed highly active facets for water splitting is desirable yet remains greatly challenging. Herein, we report a doping-induced facet transformation strategy to prepare single-crystalline cobalt carbonate hydroxide hydrate (CCOH) nanowires with high oxygen evolution reaction (OER) activity. Specifically, Cu doping induces the CCOH nanowires to grow along the (020) direction, whereas nanowires without Cu dopant grow along the (121) direction. Density functional theory calculations reveal that compared with the (121) surface, the (020) surface of CCOH has higher intrinsic OER activity due to different atomic arrangements and coordination. As a result, the Cu-doped (020)-faceted CCOH nanowire arrays exhibit outstanding OER performances with a low overpotential of 210 mV at 10 mA cm−2 and a Tafel slope of 67 mV dec−1 in alkaline medium, as well as extremely long-term durability over 36 h. Our findings demonstrate that doping-induced facet engineering is an effective strategy to design and develop highly active catalysts.
Spin-orbit charge transfer from guanine and 9-methylguanine radical cations to nitric oxide radicals and the induced triplet-to-singlet intersystem crossing
Authors: Benny Jonathan , Liu Jianbo
Published: August 2023

Nitric oxide (●NO) participates in many biological activities, including enhancing DNA radiosensitivity in ionizing radiation-based radiotherapy. To help understand the radiosensitization of ●NO, we report reaction dynamics between ●NO and the radical cations of guanine (a 9HG●+ conformer) and 9-methylguanine (9MG●+). On the basis of the formation of 9HG●+ and 9MG●+ in the gas phase and the collisions of the radical cations with ●NO in a guided-ion beam mass spectrometer, the charge transfer reactions of 9HG●+ and 9MG●+ with ●NO were examined. For both reactions, the kinetic energy-dependent product ion cross sections revealed a threshold energy that is 0.24 (or 0.37) eV above the 0 K product 9HG (or 9MG) + NO+ asymptote. To interrogate this abnormal threshold behavior, the reaction potential energy surface for [9MG + NO]+ was mapped out at closed-shell singlet, open-shell singlet, and triplet states using density functional and coupled cluster theories. The results showed that the charge transfer reaction requires the interaction of a triplet-state surface originating from a reactant-like precursor complex 3[9MG●+(↑)⋅(↑)●NO] with a closed-shell singlet-state surface evolving from a charge-transferred complex 1[9MG⋅NO+]. During the reaction, an electron is transferred from π∗(NO) to perpendicular π∗(9MG), which introduces a change in orbital angular momentum. The latter offsets the change in electron spin angular momentum and facilitates intersystem crossing. The reaction threshold in excess of the 0 K thermochemistry and the low charge-transfer efficiency are rationalized by the vibrational excitation in the product ion NO+ and the kinetic shift arising from a long-lived triplet intermediate.
Airfoil shape optimization using genetic algorithm coupled deep neural networks
Authors: Wu Ming-Yu , Yuan Xin-Yi , Chen Zhi-Hua , Wu Wei-Tao , Hua Yue , Aubry Nadine
Published: August 2023

To alleviate the computational burden associated with the computational fluid dynamics (CFD) simulation stage and improve aerodynamic optimization efficiency, this work develops an innovative procedure for airfoil shape optimization, which is implemented through coupling the genetic algorithm (GA) optimizer with the aerodynamic coefficients prediction network (ACPN) model. The ACPN is established using a fully connected neural network with the airfoil geometry as the input and aerodynamic coefficients as the output. The results show that the ACPN's mean prediction accuracy for the lift and drag coefficient is high up to about 99.02%. Moreover, the prediction time of each aerodynamic coefficient is within 5 ms, four orders of magnitude faster compared to the CFD solver (3 min). Taking advantage of the fast and accurate prediction, the proposed ACPN model replaces the expensive CFD simulations and couples with GA to force the airfoil shape change to maximize the lift–drag ratio under multiple constraints. In terms of time efficiency, optimized airfoils can be fast obtained within 25 s. Even considering an extra 50 h spent on data preparing and 20 s for model training, the overall calculation cost is reduced by a remarkable 62.1% compared to the GA-CFD optimization method (5.5 days). Furthermore, the GA-ACPN model improves the lift–drag ratio with and without constraint by 51.4% and 55.4% for NACA0012 airfoil, respectively, while 50.3% and 60.0% improvement achieved by the GA-CFD optimization method. These results indicate that the GA-ACPN optimization approach significantly enhances the optimization efficiency and has great potential to address varying constraint optimization problems.
A laterally excited bulk acoustic resonator with scattering vias in electrodes
Authors: Wen Zhiwei , Liu Wenjuan , Luo Tiancheng , Tong Xin , Xie Ying , Gu Xiyu , Liu Yan , Cai Yao , Guo Shishang , Wang Jian , Sun Chengliang
Published: August 2023

Laterally excited bulk acoustic resonators (XBARs) using interdigital electrodes are currently limited in potential 5G applications due to the accompanied spurious modes and small capacitance. This Letter presents an XBAR with scattering vias in electrodes, named SV-BAR. The non-parallel boundaries thoroughly disrupt the coherent formation of standing waves in the lateral direction, thereby suppressing the higher-order spurious modes. The duty factor of SV-BAR is optimized as 0.5 using COMSOL Multiphysics finite element analysis for the 50 Ω impedance matching. The SV-BAR is fabricated using a 390 nm Z-cut LiNbO3 on an insulator substrate and exhibits an impressive ratio of Zp/Zs near 64.5 dB, a Kt2 of 21.80% at 4.762 GHz, as well as a large value f · Bode_Qmax · Kt2 (3.43 × 1011). The measured temperature coefficient of frequency is −69.8 ppm/°C, which can be compensated using SiO2 thin films. The SV-BAR provides an effective solution for high-performance radio frequency filters for 5G communication.