bluuebunny/crossref_metadata_2025 huggingface dataset:
Adipose-derived mesenchymal stromal cells decrease prion-induced glial inflammation in vitro
Authors: Hay Arielle J. D. , Murphy Tanner J. , Popichak Katriana A. , Zabel Mark D. , Moreno Julie A.
Published: December 2022

Prion diseases are characterized by the cellular prion protein, PrPC, misfolding and aggregating into the infectious prion protein, PrPSc, which leads to neurodegeneration and death. An early sign of disease is inflammation in the brain and the shift of resting glial cells to reactive astrocytes and activated microglia. Few therapeutics target this stage of disease. Mesenchymal stromal cells produce anti-inflammatory molecules when exposed to inflammatory signals and damaged tissue. Here, we show that adipose-derived mesenchymal stromal cells (AdMSCs) migrate toward prion-infected brain homogenate and produce the anti-inflammatory molecules transforming growth factor β (TGFβ) and tumor necrosis factor-stimulated gene 6 (TSG-6). In an in vitro model of prion exposure of both primary mixed glia and BV2 microglial cell line, co-culturing with AdMSCs led to a significant decrease in inflammatory cytokine mRNA and markers of reactive astrocytes and activated microglia. This protection against in vitro prion-associated inflammatory responses is independent of PrPSc replication. These data support a role for AdMSCs as a beneficial therapeutic for decreasing the early onset of glial inflammation and reprogramming glial cells to a protective phenotype.
Immunophenotype and function of circulating myeloid derived suppressor cells in COVID-19 patients
Authors: Kiaee Fatemeh , Jamaati Hamidreza , Shahi Heshmat , Roofchayee Neda Dalil , Varahram Mohammad , Folkerts Gert , Garssen Johan , Adcock Ian M. , Mortaz Esmaeil
Published: December 2022

The pathogenesis of coronavirus disease 2019 (COVID-19) is not fully elucidated. COVID-19 is due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes severe illness and death in some people by causing immune dysregulation and blood T cell depletion. Increased numbers of myeloid-derived suppressor cells (MDSCs) play a diverse role in the pathogenesis of many infections and cancers but their function in COVID-19 remains unclear. To evaluate the function of MDSCs in relation with the severity of COVID-19. 26 PCR-confirmed COVID-19 patients including 12 moderate and 14 severe patients along with 11 healthy age- and sex-matched controls were enrolled. 10 ml whole blood was harvested for cell isolation, immunophenotyping and stimulation. The immunophenotype of MDSCs by flow cytometry and T cells proliferation in the presence of MDSCs was evaluated. Serum TGF-β was assessed by ELISA. High percentages of M-MDSCs in males and of P-MDSCs in female patients were found in severe and moderate affected patients. Isolated MDSCs of COVID-19 patients suppressed the proliferation and intracellular levels of IFN-γ in T cells despite significant suppression of T regulatory cells but up-regulation of precursor regulatory T cells. Serum analysis shows increased levels of TGF-β in severe patients compared to moderate and control subjects (HC) (P = 0.003, P < 0.0001, respectively). The frequency of MDSCs in blood shows higher frequency among both moderate and severe patients and may be considered as a predictive factor for disease severity. MDSCs may suppress T cell proliferation by releasing TGF-β.
A retrospective analysis of tumor infiltrating lymphocytes in head and neck squamous cell carcinoma patients treated with nivolumab
Authors: Kuba Kiyomi , Inoue Hitoshi , Matsumura Satoko , Enoki Yuichiro , Kogashiwa Yasunao , Ebihara Yasuhiro , Nakahira Mitsuhiko , Yamazaki Tomoko , Yasuda Masanari , Kaira Kyoichi , Kagamu Hiroshi , Sugasawa Masashi
Published: December 2022

Nivolumab, an immune checkpoint inhibitor is the first-line therapy for platinum-resistant recurrent/metastatic head and neck cancer, and highly effective for some patients. However, no factors have been identified that could predict response or prognosis after nivolumab administration. We retrospectively investigated the association between tumor infiltrating lymphocytes (TILs) of initial pathology and prognosis in patients treated with nivolumab. Twenty-eight patients with human papilloma virus and Epstein–Barr virus unrelated head and neck squamous cell carcinoma were enrolled. CD8+cells, FoxP3+cells and FoxP3−CD4+cells in the tumoral and peritumoral stromal area and PD-L1 were measured. In result, FoxP3−CD4+TIL, FoxP3+TIL, and CD8+TIL were not correlated with survival in either intratumoral and stromal area. In univariate analysis, objective response was significant prognostic factor both in progression-free survival and overall survival (p = 0.01, 0.006, respectively). PD-L1 was also significant prognostic factor both in progression-free survival and overall survival (p = 0.01, 0.01, respectively). ECOG Performance status was a significant prognostic factor in overall survival (p = 0.0009). In the combined analysis of stromal CD8+TIL and PD-L1, PD-L1 positive with high stromal CD8+TIL subgroups had a better prognosis than PD-L1 negative with low stromal CD8+TIL subgroups in progression-free survival (p = 0.006). Although these results require a further investigation, PD-L1 and ECOG Performance status and the combination of stromal CD8+TIL and PD-L1 positivity have potential as useful prognostic markers in patients of virus unrelated head and neck squamous cell carcinoma treated with nivolumab.
Two-dimensional AlN/g-CNs van der Waals type-II heterojunction for water splitting
Authors: Xu Liang , Tao Ji , Xiao Bin , Xiong Feilong , Ma Zongle , Zeng Jian , Huang Xin , Tang Shuaihao , Wang Ling-Ling
Published: December 2022

AlN/g-CNs materials are potential candidates for water splitting.
A facile precursor route towards the synthesis of Fe1−xS@NC-rGO composite anode materials for high-performance lithium-ion batteries
Authors: Zhan Guanghao , Yan Ruibo , Liao Wenhua , Hu Qianqian , Huang Xiaoying
Published: December 2022

By using an interface engineering technique, nanocomposites with a distinctive double carbon layer of protection were created, which exhibit outstanding charge and discharge performance and excellent long-term cycling stability.
Valorization of heavy metal enriched phytoremediation biomass using a deep eutectic solvent (DES)
Authors: Zhang Chenyuan , Yang Xianpeng , Yang Shuang , Liu Zhongqi , Zhang Lei , He Hailong , Qiu Wenmin , Zhuo Renying , Xu Jing , Wang Lei
Published: December 2022

Phytoremediation is an in situ environmentally friendly and economically feasible remediation technology to treat heavy metal contaminated soil.
A novel approach for the determination of exchangeable copper in serum using protein precipitation
Authors: Tuchtenhagen Max , Stiboller Michael , Witt Barbara , Schwerdtle Tanja
Published: December 2022

A novel method for the determination of exchangeable copper has been developed based on protein precipitation. This method serves as an alternative to common ultrafitration based methods.
π-Facial selectivity in the Diels–Alder reaction of glucosamine-based chiral furans and maleimides
Authors: van der Loo Cornelis H. M. , Schim van der Loeff Rutger , Martín Avelino , Gomez-Sal Pilar , Borst Mark L. G. , Pouwer Kees , Minnaard Adriaan J.
Published: December 2022

Enantiopure glucosamine based furans were used to induce π-facial selectivity in the DA cycloaddition. High π-face selectivity, up to 6.5 : 1, was achieved and afforded oxanorbornene building blocks on multi gram scale in 58–59% yield.
The Preferred Reconstructive Choice for a Lower Third Tibial Exposure Defect: An Online Survey of 356 Microsurgeons
Authors: Čebron Urška , AbdelRahman Mohamed , Kwon Soo-Ha , Lee Che-Hsiung , Hsu Angela Ting-Wei , Huang Jung-Ju , Chen Lisa Wen-Yu , Sung Cheyenne Wei-Hsuan , Chang Tommy Nai-Jen
Published: December 2022

Background One of the most challenging yet common areas in reconstructive surgery is the closure of defects in the lower leg. Surgeons can choose from several reconstructive options including local and free flaps. The aim of this study was to understand the reconstructive strategy for lower leg defects of different microsurgeons around the world by harnessing the power of social media and online questionnaires.

Methods A case of a patient with an exposed plate over distal tibial fracture was presented via an online questionnaire distributed on various social media platforms. A total of 369 international microsurgeons replied with their preferred treatment choice. The data were analyzed according to geographic area, microsurgical training, seniority, and subspecialty.

Results Among all the respondents (n = 369), 64% would have opted for a free flap reconstruction, while the remaining 36% would have opted for a local/pedicle flap. In the group that would have opted for a free flap, 63% would reconstruct the defect using a free fasciocutaneous flap, while the remaining 37% would have used a free muscle flap. In the local flap group, 60% would have used a local perforator while 30% would have chosen a conventional local flap. While North American and European microsurgeons had a clear preference toward free flaps, Asian, Middle Eastern, African, and South American surgeons were evenly divided between local and free flaps.

Conclusion In this study, we provide a current global overview of the reconstructive strategies for a lower limb with skin defect and bone or prosthesis exposure. We hope that this will be able to help global microsurgeons and patients worldwide.
Outcomes and Perioperative Risk Factors after Oncologic Free-Flap Scalp Reconstruction
Authors: Yu Jason W. , Chu Jacqueline J. , Franck Philipp , Polanco Thais O. , Shamsunder Meghana G. , Teven Chad M. , Disa Joseph J. , Matros Evan , Cordeiro Peter G. , Mehrara Babak J. , Nelson Jonas A. , Allen Robert J.
Published: December 2022

Background Little is known about the risk factors associated with complications after free flap scalp reconstruction. The purpose of this study was to identify patient, scalp defect, and flap characteristics associated with increased risk of surgical complications.

Methods A retrospective study was performed of free-flap scalp reconstruction in oncologic patients at Memorial Sloan Kettering Cancer Center from 2002 to 2017. Data collection included patient, defect, flap, and complication characteristics. Complications were classified into major, defined as complications requiring surgical intervention, and minor, defined as complications requiring conservative treatment. Risk factors and outcome variables were compared using chi-square with Fisher's exact test.

Results A total of 63 free flaps to the scalp in 58 patients were performed; average follow-up was 3.5 years. Most flaps were muscle-only or musculocutaneous. One-third of patients with free flaps experienced complications (n = 21, 15 major and 6 minor). Examining risk factors for complications, patients with cardiovascular disease were nearly three times more likely to have suffered a major complication than patients without cardiovascular disease (36.7 vs. 12.1%, p = 0.04). This was the only significant risk factor noted. Perioperative radiotherapy, prior scalp surgery, flap type, and recipient vessel selection were found to be nonsignificant risk factors.

Conclusion Cardiovascular disease may be a significant marker of risk for major complications in patients undergoing free-flap reconstruction of the scalp. This information should be used to help guide perioperative counseling and decision making in this challenging patient population.
Correlation between Risk Factors and Healing Times in Long Bone Nonunions Treated with Corticoperiosteal Flap from the Medial Femoral Condyle
Authors: Guzzini Matteo , Ciclamini Davide , Arioli Leopoldo , Titolo Paolo , Carrozzo Alessandro , Latini Francesca , Battiston Bruno , Ferretti Andrea
Published: December 2022

Background The rate of fracture nonunion varies depending on the anatomical site. Numerous procedures have been proposed to treat recalcitrant nonunions. The vascularized medial femoral condyle corticoperiosteal free flap (MFCCFF) is increasingly used in nonunions with small bone loss.

The percentage of success of the MFCCFF is high but the factors involved in delayed bone healing or failure of this technique or the contraindications are not described in the literature.

This multicentric study aims to identify and report the different factors involved in determining the time of bone healing in the treatment of atrophic nonunion of long bones with the vascularized medial MFCCFF.

Methods All patients who underwent vascularized medial MFCCFF from January 2011 to December 2020 for the treatment of recalcitrant atrophic nonunions of long bones. Patients were reviewed at 2 and 6 weeks, and 3, 6, and 12 months postoperatively and evaluated by physical and radiographic examinations and patient-reported outcome measures.

Results The final study population comprised 59 patients with a mean follow-up of 26.2 ± 7.6 months, a rate of bone healing of 94.9% with a mean radiographic bone healing time of 4.1 ± 1.3 months, and low morbidity of the donor site. Diabetes mellitus, a body mass index (BMI) ≥30 kg/m2, and ≥2 previous surgeries on the fracture site were factors predicting timing for bone healing at the multivariate analysis.

Conclusion This study demonstrates the MFCCFF as an effective and safe procedure for the treatment of the recalcitrant atrophic nonunion of long bones. An association was found between the lengthening of bone healing time and a high BMI, presence of ≥2 previous surgical interventions, and diabetes mellitus, indicating these comorbidities as risk factors (not absolute contraindications) for this microsurgical treatment. So, to our knowledge, the MFCCFF could be the first-choice treatment for atrophic nonunion of long bones.
A Case Report of Behavioural Refinement in a Child Suffering from Attention-Deficit Hyperactivity Disorder Using Individualised Homoeopathic Medicine
Authors: Singh Pravin Kumar , Naaz Sabiha
Published: December 2022

Background Attention-deficit hyperactivity disorder (ADHD) is the commonest juvenile psychiatric disorder distinguished by symptoms of inattention, hyperactivity and impulsivity. ADHD is a serious public health concern because it has a long-term negative impact on academic, career and social-emotional development, thereby hampering the quality of life of the individual. Owing to the prolonged, expensive and ambiguous treatment, an increasing number of parents turn towards homeopathy for safe and cost-effective treatment of their ‘trouble-makers’ as they are labeled.

Method A 7-year-old child diagnosed with ADHD (combined type) and patent ductus arteriosus (PDA) uncomplicated with other psychiatric comorbidity presented to the outpatient department after having consulted various physicians in succession in search of effective treatment. The child received individualised homoeopathic medicine. Outcome was measured using the parent completed Conners' Parent Rating Scale-Revised-Short version (CPRS:R-S) every 4 months.

Results At the start of the treatment, the child's CPRS:R-S score was 76 which was very high. After a year, it was reduced to eight (within normal range).

Conclusion This case demonstrates the usefulness of individualised homoeopathic treatment in improving the ADHD status over a span of 1 year. Nevertheless, large sample randomised controlled trials would be required to approve or disprove this single case observation.
MTL-P300 as a marker of the epileptogenic zone and hippocampal functionality in the presurgical evaluation of temporal lobe epilepsy: a systematic review
Authors: Morange Daniela de Andrade , Martinez-Silveira Martha Silvia , Amaral Magali Teresópolis Reis , Trebuchon Agnès
Published: December 2022

Background In the past twenty years, there has been an increasing interest among neuroscientists and physicians in mapping the cortical areas involved in the epileptogenic zone (EZ) through event-related potentials (ERPs) that enable the evaluation of the functional preservation of these areas. The present review is an update on publications on this topic.

Objective To investigate the accuracy of the cognitive evoked of the medial temporal lobe P300 (MTL-P300) potential in detecting the EZ in temporal lobe epilepsy (TLE).

Methods The systematic review of articles on the PubMed, Embase and Lilacs databases was conducted between February and December 2020. Articles published in English from 1985 to December 2020 were included. Additional studies were identified by searching the references of the selected studies and review articles. The studies were included for the following reasons: in-depth intracranial electroencephalography (iEEG) analysis of hippocampal activity; investigations of patients with TLE; and correlations between regarding the ERP results obtained in the temporal regions (MTL-P300) and the EZ.

Results In the three studies analyzed, the authors were able to define the laterality of the EZ during the preoperative investigation through the MTL-P300 results. The sensitivity of this method was of ∼ 70% to 80%, and the specificity between 70% and 94.7%. One of the limitations of the present review was the low number of studies.

Conclusion There is evidence that the reduced amplitude of the MTL-P300 has high specificity in identifying the EZ, and this is a good marker for diagnosis in unilateral TLE. The low sensitivity and negative likelihood ratios negative that a normal MTL-P300 response does not exclude the epileptogenicity of the hippocampus.
Ultrasound as a Useful Tool for a Peripheral Nerve Surgeon: Examples in Clinical Practice
Authors: Aravind Pathik , Tiongco Rafael Felix P. , McNichols Colton H. , Williams Eric H.
Published: December 2022

Background Peripheral nerve surgeons often require additional imaging for examination, diagnostic testing, and preoperative planning. Point-of-care ultrasound (US) is a cost-effective, accessible, and well-established technique that can assist the surgeon in diagnosing and treating select peripheral nerve pathologies. With this knowledge, the properly trained surgeon may perform US-guided nerve blocks to help accurately diagnose and treat causes of neuropathic pain. We offer this paper, not as an exhaustive review, but as a selection of various peripheral nerve pathologies, which the senior author treats, and their associated US examination findings. Our goal is to encourage other peripheral nerve surgeons to incorporate US into their practices.

Methods We provide various cases from our outpatient peripheral nerve clinic demonstrating relevant US anatomy. We also review techniques for US guided nerve blocks with relevant anatomic landmarks.

Results US imaging successfully assisted in identification and injection techniques for various peripheral nerve pathologies in a surgeon's practice. Examples were presented from the neck, trunk, upper extremity, and lower extremity.

Conclusion Our review highlights the use of US by a peripheral nerve surgeon in an outpatient private practice clinic to diagnose and treat select peripheral nerve pathologies. We encourage reconstructive surgeons to add US to their arsenal of diagnostic tools.
Association of Obesity and Surgery Outcomes in Patients with Endometrial Cancer: A Single-Center Analysis
Authors: Ozdemir Savas , Dogan Gul Ozel
Published: December 2022

Objective Although obesity can result in high morbidity and mortality in surgical outcomes because of multiple comorbidities, determinants of outcome in obese patients who underwent endometrial cancer surgery remain unclear. The aim of this study is to assess the relationship between body mass index (BMI) and surgical outcomes in obese patients with endometrial cancer.

Methods An institutional retrospective review of the demographic details, clinical characteristics, and follow-up data of 142 patients with endometrial cancer who underwent surgery during a 72-month period was performed. The patients were divided into three groups based on their BMI; patients with BMI < 25 were identified as normal weight, patients with BMI between 25 and 30 were accepted as overweight, and those with BMI ≥ 30 kg/m2 were identified as obese. The groups' demographic and clinical variables were compared.

Results Of the 142 patients, 42 were in the normal weight group, 55 in the overweight group, and 45 in the obese group. Age, surgical procedures, blood loss, preoperative health status, and metastatic lymph nodes did not show a significant difference between groups. However, surgery time and total lymph nodes were higher in the obese group. (p = 0.02, p = 0.00, and p = 0.00, respectively). Common complications were anemia, fever, intestinal injury, deep vein thrombosis, fascial dehiscence and urinary infection. There was no significant difference according to the complications.

Conclusion Our results indicated that higher BMI was significantly associated with a longer duration of endometrial cancer surgery. Minimally invasive surgeries and conventional laparotomy could be performed safely in obese patients.
Neonatal Screening for Sickle Cell Disease in Western Andalusia: Results and Lessons Learnt after 3 Years of Implementation
Authors: Núñez-Jurado David , Payán-Pernía Salvador , Álvarez-Ríos Ana I. , Jiménez-Jambrina Margarita , Concepcion Pérez-De-Soto Inmaculada , José Palma-Vallellano Antonio , Zapata-Bautista Rocío , Carlos Hernández-Castellet José , Paz Garrastazul-Sánchez Mari , Arqueros-Martínez Víctor , Urbano-Ramos María del Mar , Abdelkader-Maanan Mohamed , Raúl García-Lozano José , Delgado-Pecellín Carmen
Published: December 2022

Objective The aim of this study was to present the results obtained in the Newborn Screening Program (NSP) for sickle cell disease (SCD) in western Andalusia and the autonomous city of Ceuta in the first 3 years of implementation, and to describe the discrepancies found in the diagnosis of hemoglobinopathies between the screening method and the confirmatory tests.

Study Design A descriptive and retrospective study was carried out, and the findings obtained in the newborns included in the NSP between November 2018 and December 2021 were analyzed.

Results A total of 111,205 samples were screened by high-performance liquid chromatography (HPLC). The birth prevalence of SCD, sickle cell trait, hemoglobin C carriers, and the compound heterozygosity Hb C/β-thalassemia was 1/12,356, 1/467, 1/1,278, and 1/55,602 newborns, respectively. Although there was a correlation between the first-line HPLC screening technique (VARIANTnbs HPLC analyzer, Bio-Rad) and the confirmatory tests in most cases, major discrepancies were found in detecting carriers of G-Philadelphia, D, E, and O-Arab hemoglobin variants, with the former having an incidence of 1/10,110 and the others 1/22,241. The carrier status of Hb G-Philadelphia produced an FAD pattern on the screening method that could be mistaken as Hb D, while Hb O-Arab was identified as an FA5 pattern. Hb D was initially recognized as Hb D in two cases.

Conclusion An NSP requires at least two different combined methods in order to identify the hemoglobin variant with sufficient certainty. Furthermore, even though software solutions for HPLC suggest a pattern, it must be confirmed with another technique to obtain a correct interpretation of the chromatograms.

Key Points
Role of Vascular Receptors in the Development of Hypertension in the Elderly Population
Authors: Shaulian Shlomo Yosef , Makaryus Amgad N. , Zeltser Roman
Published: December 2022

Hypertension is a disease common in adults, with many risk factors and potentially life-threatening outcomes. Blood pressure is controlled by receptors that inform the brain about the amount of pressure inside the arteries, and the amount of oxygen and carbon dioxide in the blood, respectively. Research has revealed that baroreflex sensitivity (BRS) decreases with increasing age and that there is a high correlation between hypertension and low BRS. However, various studies with differing results have indicated that high blood pressure is what causes BRS to decline, and vice versa. Several studies have shown very conflicting results on the correlation between chemoreflex and age; there have been indications of chemoreflex having a positive, negative, and zero correlation with age. In several experiments, the surgical removal of the chemoreceptors of hypertensive rats was followed by a decrease in blood pressure. These animal experiments, and an additional noninvasive human experiment in which the chemoreceptors were temporarily “shut off,” are reasons why more attention should be given to chemoreceptors as a route of alleviating hypertension.
Optimization of Phenylalanine Cut-Off Value in Newborn Screening Based on Blood Sampling Time
Authors: Liu Zhijuan , Jin Huiya , Ye Minggang , Han Rui , Han Ningning , Zhao Jing
Published: December 2022

Objective The aim of this study was to optimize the cut-off value of phenylalanine (Phe) for phenylketonuria (PKU) screening in Xinjiang Uygur Autonomous Region based on the time of blood sampling.

Study Design In this study, 110,806 neonates born in 91 obstetrics and gynecology hospitals of Xinjiang Uygur Autonomous Region between June 2017 and December 2019 were divided into two groups (i.e., groups 1 and 2) based on the sampling time. The concentration of Phe was determined using fluorimetric method. The optimization of the Phe cut-off value was conducted using the receiver operating characteristic curve from the treating set involving 80,354 neonates. Then, the diagnostic values of the optimized Phe cut-off value were evaluated using validation set involving 30,452 neonates, based on the comparison of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) obtained from conventional cut-off value.

Results A range of cut-off values was used for preliminary Phe concentrations in the two groups to analyze the sensitivity, specificity, PPV, and NPV. The optimized cut-off value of Phe in group 1 was 2.0, while that in the group 2 was 2.21. A comparison was given to PPV, NPV, sensitivity, and specificity generated by the optimized cut-off value and the conventional cut-off value, which yielded similar sensitivity, specificity, and PPV, and less recalled number of samples.

Conclusion The optimization of cut-off value of Phe based on sampling time is feasible for PKU screening in Xinjiang Uygur Autonomous Region. In addition, the false positive rate was significantly reduced, which may save more efforts in sample recalling process.

Key Points
Commercial Surrogacy: An Overview
Authors: Brandão Pedro , Garrido Nicolás
Published: December 2022

Objective Surrogacy is the process in which a woman carries and delivers a baby to other person or couple, known as intended parents. When carriers are paid for surrogacy, this is known as commercial surrogacy. The objective of the present work is to review the legal, ethical, social, and cultural aspects of commercial surrogacy, as well as the current panorama worldwide.

Methods This is a review of the literature published in the 21st century on commercial surrogacy.

Results A total of 248 articles were included as the core of the present review. The demand for surrogate treatments by women without uterus or with important uterine disorders, single men and same-sex male couples is constantly increasing worldwide. This reproductive treatment has important ethical dilemmas. In addition, legislation defers widely worldwide and is in constant change. Therefore, patients look more and more for treatments abroad, which can lead to important legal problems between countries with different laws. Commercial surrogacy is practiced in several countries, in most of which there is no specific legislation. Some countries have taken restrictive measures against this technique because of reports of exploitation of carriers.

Conclusion Commercial surrogacy is a common practice, despite important ethical and legal dilemmas. As a consequence of diverse national legislations, patients frequently resort to international commercial surrogacy programs. As of today, there is no standard international legal context, and this practice remains largely unregulated.
Forgotten Poles in the history of neurology: from Flatau to Frey
Authors: Gotowiec Mateusz
Published: December 2022

With the majority of eponyms being removed from disease classification systems, it is even more difficult to remember the neurologists who influenced the development of techniques and understanding of the brain over the last centuries. Determining whether Polish researchers were given similar attention to Western equivalents based on eponymic presence in medical databases is an interesting way to provide an overview of unremembered Polish neurologists. This work aims to recognize the developments of forgotten Polish neurologists, whose work, although important, was not properly appreciated over the centuries.
Thermal laser evaporation of elemental metal sources in oxygen
Authors: Kim Dong Yeong , Smart Thomas J. , Majer Lena , Smink Sander , Mannhart Jochen , Braun Wolfgang
Published: December 2022

Thermal laser epitaxy (TLE) is a novel film growth technique capable of fabricating ultrapure films of many material systems. For growing oxide films with TLE, the impact of source oxidation on the evaporation rate is a central issue, which, however, has not yet been explored systematically. Here, we report a systematic, experimental study of the role of source oxidation on source evaporation at various oxygen pressures and source temperatures in TLE. The volatility of the oxidized metal sources affects the source evaporation rate. When the oxidized metal source is more volatile than the metal, the source evaporation rate increases with the oxygen supply. In a strongly oxidizing environment, stable oxides with lower volatility tend to form and decrease the evaporation rate of the source. Increasing the laser power—and thereby the source temperature—tends to prevent the formation of stable oxides. At even higher source temperatures, the metal vapor pressure can dominate the oxide vapor pressure even in a high oxygen pressure atmosphere. A power-law relation between deposition rate and oxidizing gas pressure is found in case the formation and evaporation of volatile oxides of the elemental source material dominates the total evaporation process. The exponent of this law is a measure of the relevance of source oxidation for the evaporation of the source.
Highly morphing and reconfigurable fluid–solid interactive metamaterials for tunable ultrasonic guided wave control
Authors: Song Yihao , Shen Yanfeng
Published: December 2022

Fluid–structural interactions enable the alternation of local resonance behaviors of elastic metamaterial unit cells. Magnetically active ferrofluids facilitate reconfiguration couplings for breaking and tunneling ultrasonic wave energy transmission. This Letter presents a magnetic fluid–solid interactive metamaterial to achieve the tunable manipulation of multimodal, dispersive ultrasonic guided waves. It is revealed that the phenomenon of the fluid–structure interaction plays an indispensable role in the achievement of bandgap formation and translation. The tunable mechanism stems from the variation of the fluid–solid coupling reconfiguration arising from liquid morphing via electromagnetic stimuli. The tunable wave control performance was explicitly validated through both numerical simulations and experimental verifications. Such an active metamaterial system may possess application potential for future highly flexible and tunable wave control, e.g., selective-tunnel waveguiding and adaptive mechanical frequency filtering.
Notch sensitivity of polymer-based thermal interface materials
Authors: Cai Linfeng , He Dongyi , Peng Xu , Fan Jianfeng , Ding Shengchang , Zeng Xiangliang , Sun Rong , Ren Linlin , Zhong Cheng , Lu Jibao , Zeng Xiaoliang
Published: December 2022

Thermal interface materials (TIMs) used between the chip and the heat spreader play an indispensable role in effective heat removal to ensure the chip's performance and reliability. As they suffer from stresses in practical applications, TIMs need to have high toughness to resist fracture. The notch sensitivity of TIMs is considered an important parameter to evaluate its toughness. However, the notch sensitivity of TIMs is seldom mentioned, and the mechanism to enhance the toughness is still unclear. Here, using polymer-based TIMs consisting of polydimethylsiloxane/aluminum as a model, we specifically investigate notch sensitivity of TIMs and analyze the mechanical mechanism in detail from the macroscopic and microscopic scales. It was found that a transition from notch insensitive to notch sensitive will happen with a notch length of 2.0 mm, which is much higher than typical soft materials, such as hydrogels. We interpret the notch sensitivity of the TIM by finite element analysis at macroscopic scales and the Lake–Thomas theory at microcosmic scales. The relationship between the area of the strain concentration region to the notch length in finite element analysis is in good agreement with the fracture stretch ratio with different notch lengths measured in a uniaxial tensile experiment. This investigation gives an insight into designing notch-insensitivity TIM and understanding their fracture behavior.
Data-driven construction of stochastic reduced dynamics encoded with non-Markovian features
Authors: She Zhiyuan , Ge Pei , Lei Huan
Published: December 2022

One important problem in constructing the reduced dynamics of molecular systems is the accurate modeling of the non-Markovian behavior arising from the dynamics of unresolved variables. The main complication emerges from the lack of scale separations, where the reduced dynamics generally exhibits pronounced memory and non-white noise terms. We propose a data-driven approach to learn the reduced model of multi-dimensional resolved variables that faithfully retains the non-Markovian dynamics. Different from the common approaches based on the direct construction of the memory function, the present approach seeks a set of non-Markovian features that encode the history of the resolved variables and establishes a joint learning of the extended Markovian dynamics in terms of both the resolved variables and these features. The training is based on matching the evolution of the correlation functions of the extended variables that can be directly obtained from the ones of the resolved variables. The constructed model essentially approximates the multi-dimensional generalized Langevin equation and ensures numerical stability without empirical treatment. We demonstrate the effectiveness of the method by constructing the reduced models of molecular systems in terms of both one-dimensional and four-dimensional resolved variables.
Planar acoustomagnetoelectric effect in three-dimensional Dirac materials
Authors: Margulis Vl. A. , Muryumin E. E.
Published: December 2022

Using the Boltzmann equation techniques, we develop a theory of the planar acoustomagnetoelectric (AME) effect in three-dimensional (3D) gapless Dirac materials with a linear (massless) dispersion law of conduction electrons. The effect arises if the magnetic field H applied to the sample makes an angle Φ≠0, π/2 with the wavevector q of the acoustic wave and consists in the appearance of a dc electric field Eac directed perpendicular to the wavevector q, with all three vectors q, H, and Eac lying in the same plane. We study this effect in the quantum regime (the electron mean free path l0 is large compared to the wavelength 2π/q), where it occurs as a result of the momentum transfer from an excited acoustic wave, considered a flow of individual acoustic quanta, to conduction electrons subjected to the magnetic field. Our theory predicts that for the 3D Dirac material Cd3As2 exposed to a strong, but non-quantizing magnetic field H=10 kOe and an acoustic wave with a frequency of 10 GHz and an intensity of 2 kW/cm2, the AME field Eac with its specific angular dependence (Eac∝sin⁡2Φ) can reach values of the order of 0.01 V/cm at room temperature, which can be readily measured in the experiment.
Probe and control of photo-excited magnetization precession in Co/Pd multilayer films at low laser fluence regime
Authors: Smith Nicholas W. G. , Pleimling Yannick , Magill Brenden A. , Mudiyanselage Rathsara R. H. H. , Shenenberger Alex , Ogawa Shunta , Nishizawa Nozomi , Munekata Hiro , Khodaparast Giti A.
Published: December 2022

We present femtosecond-pulse-induced precession of magnetization at low laser fluence (<5μJ/cm2) regime as a function of magnetic field and laser fluence in three Co/Pd multilayer (ML) systems. These systems belong to three different regimes of magnetic anisotropy that vary with Co thickness (tCo): in-plane (sample 1, tCo = 0.74 nm), weakly out-of-plane (sample 2, tCo = 0.6 nm), and out-of-plane (sample 3, tCo = 0.40 nm). Interestingly, we observed that the precession amplitudes increase significantly with decreasing the Co layer thickness. In this study, the influence of various spin dynamics and static magneto-optical parameters on precession amplitude is examined critically and compared with a previously proposed analytical expression that connects those quantities. It is found that the enhancement of structural-dependent energy transfer efficiency between charge and spin subsystems is indeed responsible for the observed variations in precession amplitudes. On the basis of this fact, we discuss that the spin–orbit interaction that yields perpendicularly spin-polarized electrons in the MLs through the Co/Pd interface is responsible for the observed increase in precession amplitudes of locally excited magnetization. Our approach of employing low-fluence laser excitation of magnetization precession could be practical for developing a non-thermal, all-optical magnetic switching toward photonic memory applications.
Pressure induced modification of the electronic properties of stilbene by two-photon spectroscopy
Authors: Agati M. , Fanetti S. , Bini R.
Published: December 2022

Carbon nanothreads are the most exciting carbon based nanomaterials recently discovered. Obtained by compressing aromatics around 20 GPa, they are characterized by potentially exceptional mechanical properties. The reaction mechanisms have been partly elucidated through computational studies and x-ray diffraction experiments. However, in all these studies, the electronic modifications to which the molecule is subjected with increasing pressure are neglected as also if, and to which extent, the electronic excited states are involved in the high-pressure reactivity. In fact, the pressure increase induces remarkable changes in the electronic properties of molecular crystals, which are often directly related to the reaction’s onset and path. We report the pressure evolution of the two-photon induced emission spectrum of crystalline stilbene, the archetype of a class of molecules from which double-core nanothreads are obtained, with the twofold purpose of gaining insight into the reaction mechanism and monitoring if the structural changes observed in x-ray diffraction studies have a detectable counterpart in the electronic properties of the system. The freezing of the spectral diffusion observed on rising pressure is ascribed to a hampered conformational rearrangement because of the larger stiffness of the local environment. The transition to the high pressure phase where the nanothreads form is revealed by the slope change of the pressure shift of all spectral components, while the progressive intensification with pressure of the 0-0 transition suggests a strengthening of the ethylenic bond favoring the charge delocalization on the benzene moieties, which is likely the trigger of the chemical instability.
A study on prenucleation and heterogeneous nucleation in liquid Pb on solid Al using molecular dynamics simulations
Authors: Men H. , Fan Z.
Published: December 2022

In this paper, we investigate prenucleation and heterogeneous nucleation in the liquid Pb/solid Al system as an example of systems with large lattice misfit using molecular dynamics simulation. Solid Pb and Al have a large positive lattice misfit (f) of 18.2% along the densely packed [110] direction. This study reveals that prenucleation occurs at 600 K (an undercooling of 15 K), and a 2-dimensional (2D) ordered structure forms at the interface with a coincidence site lattice (CSL) between the first Pb and first Al layers. The CSL accommodates the major part of the f, and only a small residual lattice misfit (fr) of 1.9% remains. The formation of the CSL transforms the original substrate into a considerably potent nucleant, where the first Pb layer becomes the new surface layer of the substrate. At an undercooling of about 22 K, nucleation proceeds by merging 2D ordered structure through structural templating: the second Pb layer is epitaxial to the CSL Pb layer, the third Pb layer largely accommodates the fr, and the fourth Pb layer is a nearly perfect crystalline plane. Further analysis indicates that the interface with the CSL has a lower interfacial energy than with a cube-to-cube orientation relationship. For the first time, we established that the CSL was an effective mechanism to accommodate the f for systems with a large positive misfits. Heterogeneous nucleation is governed not by a single mechanism (misfit dislocations in Turnbull’s model), but instead by various mechanisms depending on f. This study sheds new light on the atomistic mechanism of heterogeneous nucleation.
On the flow characteristics of two supercavitating projectiles moving in water side-by-side
Authors: Qi Chao , Wang Xu , Lyu Xujian
Published: December 2022

Multiple projectiles moving in water often encounter problems such as motion disturbance from adjacent body and unsteady cavity coupling, making the flow structure and motion characteristics very complex. In this study, a computational fluid dynamics (CFD) method is employed to model two parallel supercavitating projectiles moving in water side-by-side. The cavity characteristics and flow details around the two projectiles are presented, and the variation of mutual disturbance with axis distance and flow velocity are analyzed. Numerical results show that the two cavities feature good mirror symmetry, and the influence of axis distance and flow velocity on the cavity contour is mainly reflected in the varying cavity diameter and length. It is found that the parallel projectiles repel each other at different axis distances and flow velocities. It is more easily for the parallel projectiles to achieve supercavitating motion state than a single projectile due to the flow interaction between the twin projectiles.
Quantum-chemical calculation of two-dimensional infrared spectra using localized-mode VSCF/VCI
Authors: Brüggemann Julia , Wolter Mario , Jacob Christoph R.
Published: December 2022

Computational protocols for the simulation of two-dimensional infrared (2D IR) spectroscopy usually rely on vibrational exciton models which require an empirical parameterization. Here, we present an efficient quantum-chemical protocol for predicting static 2D IR spectra that does not require any empirical parameters. For the calculation of anharmonic vibrational energy levels and transition dipole moments, we employ the localized-mode vibrational self-consistent field (L-VSCF)/vibrational configuration interaction (L-VCI) approach previously established for (linear) anharmonic theoretical vibrational spectroscopy [P. T. Panek and C. R. Jacob, ChemPhysChem 15, 3365–3377 (2014)]. We demonstrate that with an efficient expansion of the potential energy surface using anharmonic one-mode potentials and harmonic two-mode potentials, 2D IR spectra of metal carbonyl complexes and dipeptides can be predicted reliably. We further show how the close connection between L-VCI and vibrational exciton models can be exploited to extract the parameters of such models from those calculations. This provides a novel route to the fully quantum-chemical parameterization of vibrational exciton models for predicting 2D IR spectra.
Investigation of cavitation bubble dynamics near a solid wall by high-resolution numerical simulation
Authors: Bußmann Alexander , Riahi Farbod , Gökce Bilal , Adami Stefan , Barcikowski Stephan , Adams Nikolaus A.
Published: December 2022

We investigate dynamics of a single cavitation bubble in the vicinity of a horizontal wall throughout expansion and collapse using a sharp–interface level-set method. The numerical scheme is based on a finite-volume formulation with low-dissipation high-order reconstruction schemes. Viscosity and surface tension are taken into account. The simulations are conducted in three-dimensional axi-symmetric space. A wide range of initial bubble wall standoff distances is covered. We focus, however, on the near-wall region where the distance between the bubble and the wall is small. We reproduce three jetting regimes: needle, mixed, and regular jets. The needle jets impose a significant load on the solid wall, exceeding the force induced by the collapse of the pierced torus bubble. For intermediate standoff distances, the large delay time between jet impact and torus bubble collapse leads to a significant decrease in the imposed maximum wall pressure. A liquid film between bubble and wall is observed whenever the bubble is initially detached from the wall. Its thickness increases linearly for very small standoff distances and growths exponentially for intermediate distances leading to a significant increase in wall-normal bubble expansion and bubble asymmetry. For configurations where the torus bubble after jet impact reaches maximum size, the collapse time of the cavitation bubble also is maximal, leading to a plateau in the overall prolongation of the cycle time of the bubble. Once the initial bubble is attached to the solid wall, a significant drop of all macroscopic time and length scales toward a hemispherical evolution is observed.
Pressure-induced negative capacitance and enhanced grain boundary conductivity in nanocrystalline solid electrolyte BaZrO3
Authors: Duan Susu , Wang Qinglin , Zou Boyu , Jiang Jialiang , Liu Kai , Zhang Guozhao , Zhang Haiwa , Sang Dandan , Xu Zhenzhen , Geng Yanlei , Li Jianfu , Wang Xiaoli , Li Yinwei , Liu Cailong
Published: December 2022

Proton-conducting BaZrO3-doped electrolytes are considered as potential high temperature proton conductors due to their high ionic conductivity and electrical efficiency in the operating temperature range of solid oxide fuel cells. However, doping leads to a decrease in grain boundary conductivity and greatly limits its applications. Here, the charge transport properties of sub-micro and nano-BaZrO3 electrolytes were studied by in situ high-pressure impedance measurements and first-principles calculations. Mixed ionic-electronic conduction was found in both samples in the whole pressure range. Pressure-induced negative capacitance in the tetragonal phase of nano-BaZrO3 was observed, which was related to the space charge layer of grain boundaries as well as the electrostrictive strain of grains. The enhanced electrostrictive effect was attributed to the existence of polar nano-domains in nano-BaZrO3. Furthermore, the coincident imaginary part of impedance and modulus peaks on the frequency scale indicated a non-localized carrier conduction in the tetragonal phase of nano-BaZrO3. The grain boundary conductivity of nano-BaZrO3 was enhanced by four orders of magnitude, and the impedance response changed from a constant phase element to an ideal capacitance, which was accompanied by the cubic to tetragonal phase transition. At a switching frequency of 0.1 Hz, the real part of the dielectric function of nano-BaZrO3 increases sharply with frequencies from negative to positive values, exhibiting a plasma-like Drude behavior. Our results provide insight into the optimization and application of BaZrO3-based proton conductors in solid oxide fuel cells.