bluuebunny/crossref_metadata_2025 huggingface dataset:
Human BM-MSC secretome enhances human granulosa cell proliferation and steroidogenesis and restores ovarian function in primary ovarian insufficiency mouse model
Authors: Park Hang-soo , Chugh Rishi Man , El Andaloussi Abdeljabar , Hobeika Elie , Esfandyari Sahar , Elsharoud Amro , Ulin Mara , Garcia Natalia , Bilal Mahmood , Al-Hendy Ayman
Published: February 2021

Primary ovarian insufficiency (POI) is defined as the loss of ovarian function before 40 years of age. It clinically manifests as amenorrhea, infertility, and signs of estrogen insufficiency. POI is frequently induced by chemotherapy. Gonadotoxic chemotherapy reagents damage granulosa cells, which are essential for follicular function and development. Our recently published studies demonstrated that intraovarian transplantation of human mesenchymal stem cells (hMSCs) can restore fertility in a chemotherapy-induced POI mouse model. However, the regenerative mechanism underlying the hMSC effect in POI mice is not fully understood. Here, we report that the hMSC secretome increased the proliferation of human granulosa cells (HGrC1). We showed by FACS analysis that treatment of HGrC1 cells with hMSC-conditioned media (hMSC CM) stimulates cellular proliferation. We also demonstrated that the expression of steroidogenic enzymes involved in the production of estrogen, CYP19A1 and StAR, are significantly elevated in hMSC CM-treated HGrC1 cells. Our data suggest that hMSC CM stimulates granulosa cell proliferation and function, which may explain the therapeutic effect of hMSCs in our chemotherapy-induced POI animal model. Our findings indicate that the hMSC secretome may be a novel treatment approach for restoring granulosa cell and ovarian function in patients with POI.
A highly sensitive octopus-like azobenzene fluorescent probe for determination of abamectin B1 in apples
Authors: Guo Zhenlong , Su YiFei , Li Kexin , Tang MengYi , Li Qiang , Xu Shandong
Published: February 2021

The development of detecting residual level of abamectin B1 in apples is of great importance to public health. Herein, we synthesized a octopus-like azobenzene fluorescent probe 1,3,5-tris (5′-[(E)-(p-phenoxyazo) diazenyl)] benzene-1,3-dicarboxylic acid) benzene (TPB) for preliminary detection of abamectin B1 in apples. The TPB molecule has been characterized by ultraviolet–visible absorption spectrometry, 1H-nuclear magnetic resonance, fourier-transform infrared (FT-IR), electrospray ionization mass spectroscopy (ESI-MS) and fluorescent spectra. A proper determination condition was optimized, with limit of detection and limit of quantification of 1.3 µg L−1 and 4.4 μg L−1, respectively. The mechanism of this probe to identify abamectin B1 was illustrated in terms of undergoing aromatic nucleophilic substitution, by comparing fluorescence changes, FT-IR and ESI-MS. Furthermore, a facile quantitative detection of the residual abamectin B1 in apples was achieved. Good reproducibility was present based on relative standard deviation of 2.2%. Six carboxyl recognition sites, three azo groups and unique fluorescence signal towards abamectin B1 of this fluorescent probe demonstrated reasonable sensitivity, specificity and selectivity. The results indicate that the octopus-like azobenzene fluorescent probe can be expected to be reliable for evaluating abamectin B1 in agricultural foods.
Role of the V1G1 subunit of V-ATPase in breast cancer cell migration
Authors: De Luca Maria , Romano Roberta , Bucci Cecilia
Published: February 2021

V-ATPase is a large multi-subunit complex that regulates acidity of intracellular compartments and of extracellular environment. V-ATPase consists of several subunits that drive specific regulatory mechanisms. The V1G1 subunit, a component of the peripheral stalk of the pump, controls localization and activation of the pump on late endosomes and lysosomes by interacting with RILP and RAB7. Deregulation of some subunits of the pump has been related to tumor invasion and metastasis formation in breast cancer. We observed a decrease of V1G1 and RAB7 in highly invasive breast cancer cells, suggesting a key role of these proteins in controlling cancer progression. Moreover, in MDA-MB-231 cells, modulation of V1G1 affected cell migration and matrix metalloproteinase activation in vitro, processes important for tumor formation and dissemination. In these cells, characterized by high expression of EGFR, we demonstrated that V1G1 modulates EGFR stability and the EGFR downstream signaling pathways that control several factors required for cell motility, among which RAC1 and cofilin. In addition, we showed a key role of V1G1 in the biogenesis of endosomes and lysosomes. Altogether, our data describe a new molecular mechanism, controlled by V1G1, required for cell motility and that promotes breast cancer tumorigenesis.
The mitral regurgitation effects of cardiac structure and function in left ventricular noncompaction
Authors: Zou Qing , Xu Rong , Li Xiao , Xu Hua-yan , Yang Zhi-gang , Wang Yi-ning , Fan Hai-ming , Guo Ying-kun
Published: February 2021

This study evaluated the effects of mitral regurgitation (MR) on cardiac structure and function in left ventricular noncompaction (LVNC) patients. The clinical and cardiovascular magnetic resonance (CMR) data for 182 patients with noncompaction or hypertrabeculation from three institutes were retrospectively included. We analyzed the difference in left ventricular geometry, cardiac function between LVNC patients with and without MR. The results showed that patients with MR had a worse New York Heart Association (NYHA) class and a higher incidence of arrhythmia (P < 0.05). MR occurred in 48.2% of LVNC patients. Compared to LVNC patients without MR, the two-dimensional sphericity index, maximum/minimum end-diastolic ratio and longitudinal shortening in LVNC patients with MR were lower (P < 0.05), and the peak longitudinal strain (PLS) of the global and segmental myocardium were obviously reduced (P < 0.05). No significant difference was found in strain in LVNC patients with different degree of MR; end diastolic volume, end systolic volume, and global PLS were statistically associated with MR and NYHA class (P < 0.05), but the non-compacted to compacted myocardium ratio had no significant correlation with them. In conclusion, the presence of MR is common in LVNC patients. LVNC patients with MR feature more severe morphological and functional changes. Hypertrabeculation is not an important factor affecting structure and function at the heart failure stage.
A convention-radiomics CT nomogram for differentiating fat-poor angiomyolipoma from clear cell renal cell carcinoma
Authors: Ma Yanqing , Ma Weijun , Xu Xiren , Guan Zheng , Pang Peipei
Published: February 2021

This study aimed to construct convention-radiomics CT nomogram containing conventional CT characteristics and radiomics signature for distinguishing fat-poor angiomyolipoma (fp-AML) from clear-cell renal cell carcinoma (ccRCC). 29 fp-AML and 110 ccRCC patients were enrolled and underwent CT examinations in this study. The radiomics-only logistic model was constructed with selected radiomics features by the analysis of variance (ANOVA)/Mann–Whitney (MW), correlation analysis, and Least Absolute Shrinkage and Selection Operator (LASSO), and the radiomics score (rad-score) was computed. The convention-radiomics logistic model based on independent conventional CT risk factors and rad-score was constructed for differentiating. Then the relevant nomogram was developed. Receiver operation characteristic (ROC) curves were calculated to quantify the accuracy for distinguishing. The rad-score of ccRCC was smaller than that of fp-AML. The convention-radioimics logistic model was constructed containing variables of enhancement pattern, VUP, and rad-score. To the entire cohort, the area under the curve (AUC) of convention-radiomics model (0.968 [95% CI 0.923–0.990]) was higher than that of radiomics-only model (0.958 [95% CI 0.910–0.985]). Our study indicated that convention-radiomics CT nomogram including conventional CT risk factors and radiomics signature exhibited better performance in distinguishing fp-AML from ccRCC.
Quantifying the alignment error and the effect of incomplete somatosensory feedback on motor performance in a virtual brain–computer-interface setup
Authors: Lienkämper Robin , Dyck Susanne , Saif-ur-Rehman Muhammad , Metzler Marita , Ali Omair , Klaes Christian
Published: February 2021

Invasive brain–computer-interfaces (BCIs) aim to improve severely paralyzed patient’s (e.g. tetraplegics) quality of life by using decoded movement intentions to let them interact with robotic limbs. We argue that the performance in controlling an end-effector using a BCI depends on three major factors: decoding error, missing somatosensory feedback and alignment error caused by translation and/or rotation of the end-effector relative to the real or perceived body. Using a virtual reality (VR) model of an ideal BCI decoder with healthy participants, we found that a significant performance loss might be attributed solely to the alignment error. We used a shape-drawing task to investigate and quantify the effects of robot arm misalignment on motor performance independent from the other error sources. We found that a 90° rotation of the robot arm relative to the participant leads to the worst performance, while we did not find a significant difference between a 45° rotation and no rotation. Additionally, we compared a group of subjects with indirect haptic feedback with a group without indirect haptic feedback to investigate the feedback-error. In the group without feedback, we found a significant difference in performance only when no rotation was applied to the robot arm, supporting that a form of haptic feedback is another important factor to be considered in BCI control.
Hamiltonian transformability, fast adiabatic dynamics and hidden adiabaticity
Authors: Wu Lian-Ao , Segal Dvira
Published: February 2021

We prove the existence of a unitary transformation that enables two arbitrarily given Hamiltonians in the same Hilbert space to be transformed into one another. The result is straightforward yet, for example, it lays the foundation to implementing or mimicking dynamics with the most controllable Hamiltonian. As a promising application, this existence theorem allows for a rapidly evolving realization of adiabatic quantum computation by transforming a Hamiltonian where dynamics is in the adiabatic regime into a rapidly evolving one. We illustrate the theorem with examples.
Vitamin D receptor gene polymorphisms and haplotypes in the etiology of recurrent miscarriages
Authors: Wolski Hubert , Kurzawińska Grażyna , Ożarowski Marcin , Mrozikiewicz Aleksandra E. , Drews Krzysztof , Karpiński Tomasz M. , Bogacz Anna , Seremak-Mrozikiewicz Agnieszka
Published: February 2021

A few years ago it was shown that disturbed metabolism of the vitamin D/receptor (VD/VDR) complex may be important in the etiology of spontaneous abortion, as well as in the etiology of recurrent miscarriages (RM). The goal of this study was to investigate the association between four maternal VDR polymorphisms as well as haplotypes settings and RM occurrence in a Polish population of women in reproductive age. A total of 230 women were recruited to this study (110 with RM, 120 consecutively recruited age-matched healthy women with at least two full-term pregnancies and with no history of miscarriages). DNA samples were genotyped for VDR polymorphisms: FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236). Significant differences in genotype distributions and allele frequencies between case and control groups were observed in VDR BsmI polymorphism (GG vs. GA and AA, OR = 0.56, p = 0.036 and OR = 1.49, p = 0.035, respectively). The best evidence of an association with RM prevention was observed for the TTGT haplotype, which was more frequent among controls than cases even after permutation test (0.09 vs. 0.017, p = 0.0024). Other haplotypes were also significantly more frequent in the control group: TGT (rs7975232, rs1544410, rs2228570), TG (rs7975232, rs1544410), TTG (rs731236, rs7975232, rs1544410), TT (rs731236, rs7975232). Our research indicated the possible role of VDR BsmI genetic polymorphism in RM etiology, suggesting at the same time the active role of maternal VD metabolism and its influence on pregnancy outcome. The significant influence of several maternal haplotypes was shown to prevent RM occurrence.
The behavior of residual tumors following incomplete surgical resection for vestibular schwannomas
Authors: Park Hun Ho , Park So Hee , Oh Hyeong-Cheol , Jung Hyun-Ho , Chang Jong Hee , Lee Kyu-Sung , Chang Won Seok , Hong Chang-Ki
Published: February 2021

The management of vestibular schwannoma (VS) with residual tumor following incomplete resection remains controversial and little is known regarding postoperative tumor volume changes. The behavior of residual tumors was analyzed for 111 patients who underwent surgery for newly diagnosed VS between September 2006 and July 2017. The postoperative tumor volume changes were assessed during a mean follow-up of 69 months (range 36–147 months). Fifty-three patients underwent imaging surveillance following incomplete resection. There was no residual tumor growth in 44 patients (83%). A significant regression of residual tumor volume was noted in the no growth group at postoperative 1 year (p = 0.028), 2 years (p = 0.012), but not from 3 years onwards. Significant predictors of regrowth were immediate postoperative tumor volume ≥ 0.7 cm3 (HR 10.5, p = 0.020) and residual tumor location other than the internal auditory canal (IAC) (HR 6.2, p = 0.026). The mean time to regrowth was 33 months (range 5–127 months). The 2-, 5-, and 10-year regrowth-free survival rates were 90.6%, 86.8%, and 83%, respectively. In conclusion, significant residual tumor regression could occur within 2 years for a VS with an immediate postoperative tumor volume less than 0.7 cm3 or residual tumor in IAC.
Author Correction: CTCF interacts with the lytic HSV-1 genome to promote viral transcription
Authors: Lang Fengchao , Li Xin , Vladimirova Olga , Hu Benxia , Chen Guijun , Xiao Yu , Singh Vikrant , Lu Danfeng , Li Lihong , Han Hongbo , Wickramasinghe J. M. A. S. P. , Smith Sheryl T. , Zheng Chunfu , Li Qihan , Lieberman Paul M. , Fraser Nigel W. , Zhou Jumin
Published: February 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Publisher Correction: Low Antarctic continental climate sensitivity due to high ice sheet orography
Authors: Singh Hansi A. , Polvani Lorenzo M.
Published: February 2021

A Correction to this paper has been published: https://doi.org/10.1038/s41612-021-00170-1
Stable nitrogen-rich scandium nitrides and their bonding features under ambient conditions
Authors: Lin Jiani , Peng Dong , Wang Qinglin , Li Jianfu , Zhu Hongyang , Wang Xiaoli
Published: February 2021

Enthalpies of formation of P1̄-ScN3 and C2/m-ScN5 are predicted relative to ScN and N2 with CALYPSO structural search.
Perfecting electrocatalystsviaimperfections: towards the large-scale deployment of water electrolysis technology
Authors: Jiao Shilong , Fu Xianwei , Wang Shuangyin , Zhao Yong
Published: February 2021

A tuned electronic structure favors the electrocatalytic water splitting reactionviaaccelerating the reaction kinetics, changing the rate-determining step, and optimizing the adsorption energy for intermediates; this is achievedviaintentionally incorporating imperfections into the crystal lattices of electrocatalysts.
Dual transition-metal atoms doping: an effective route to promote the ORR and OER activity on MoTe2
Authors: Gao Can , Rao Dewei , Yang Huan , Yang Shaokang , Ye Jingjing , Yang Shasha , Zhang Chaonan , Zhou Xuecheng , Jing Tianyun , Yan XiaoHong
Published: February 2021

Compared to traditional single-atom doping method, the OER/ORR electrocatalytic activity of inert 2H-MoTe2 can be efficiently triggered by properly dual TM atoms doping.
Measuring trapped DNA at the liquid-air interface for enhanced single molecule sensing
Authors: Farajpour Nasim , Lastra Lauren S. , Sharma Vinay , Freedman Kevin J.
Published: February 2021

Higher capture rate and enhanced sensing at the liquid-air interface using nanopores.
A palladium doped 1T-phase molybdenum disulfide–black phosphorene two-dimensional van der Waals heterostructure for visible-light enhanced electrocatalytic hydrogen evolution
Authors: Song Xiancheng , Li Bin , Peng Wenchao , Wang Chi , Li Kai , Zhu Yuanzhi , Mei Yi
Published: February 2021

We synthesized a well-defined 2D van der Waals heterostructure composed of Pd doped 1T-phase MoS2 and black phosphorene. The hetero-interfacial charge transfer improve the visible-light enhanced eletrocatalytic hydrogen evolution performance.
Chemical tuning of spin clock transitions in molecular monomers based on nuclear spin-free Ni(ii)
Authors: Rubín-Osanz Marcos , Lambert François , Shao Feng , Rivière Eric , Guillot Régis , Suaud Nicolas , Guihéry Nathalie , Zueco David , Barra Anne-Laure , Mallah Talal , Luis Fernando
Published: February 2021

We have directly monitored spin level anti-crossings, or “clock transitions”, in Ni(ii) molecular monomers and shown that the quantum tunnelling gap admits a chemical tuning.
Microswimmers near corrugated, periodic surfaces
Authors: Kurzthaler Christina , Stone Howard A.
Published: February 2021

We derive an analytical theory for the hydrodynamic interactions between microswimmers and corrugated surfaces and study the impact of a periodic surface on the velocities of active agents.
Synthesis of an industrial by-product-based polymeric additive for use with non-coking coal in metallurgical coke making and a combined density functional theory assessment of its molecular mechanism in fluidity development
Authors: Ghorai Soumitra , Sen Kaushik , Nag Debjani , Dash Pratik Swarup
Published: February 2021

Coal tar-based polymeric additive enhances the coke quality (CSR) of a non-coking coal enriched blend during carbonization, which opens a new window in the steel-making industry.
Determination of perchlorate in tea using SERS with a superhydrophobically treated cysteine modified silver film/polydimethylsiloxane substrate
Authors: Guo Zhiming , Chen Ping , Wang Mingming , Barimah Alberta Osei , Chen Quansheng , El-Seedi Hesham R. , Zou Xiaobo
Published: February 2021

Perchlorate is a new type of persistent pollutant, which interferes with the synthesis and secretion of thyroxine and affects human health.
Nitrochloranilic acid: a novel asymmetrically substituted quinoid bridging ligand for design of coordination polymers
Authors: Milašinović Valentina , Jurić Marijana , Molčanov Krešimir
Published: February 2021

A series of alkali salts and transition metal complexes of a novel asymmetrically substituted quinoid ligand, 3-nitro-6-chloro-2,5-dihydroxyquinone (nitrochloranilic acid, H2NCA) was prepared and characterised.
Experimental and theoretical studies on the formation of pure β-phase polymorphs during fabrication of polyvinylidene fluoride membranes by cyclic carbonate solvents
Authors: Ismail Norafiqah , Essalhi Mohamed , Rahmati Mahmoud , Cui Zhaoliang , Khayet Mohamed , Tavajohi Naser
Published: February 2021

The preparation of β-phase PVDF membranes using three green, inexpensive, and biodegradable cyclic carbonate solvents: ethylene carbonate, propylene carbonate, and butylene carbonate.
Development of completely furfural-based renewable polyesters with controllable properties
Authors: Zhang Haiyan , Jiang Min , Wu Yuanpeng , Li Lu , Wang Zhipeng , Wang Rui , Zhou Guangyuan
Published: February 2021

23 novel bio-based polyesters with high molecular weight were obtained via melt polycondensation. A series of novel quadri-copolyesters PBTCx(SnFm)y were synthesized, affording excellent comprehensive properties compared to commercial petrochemical polyesters.
Amoeba-inspired reengineering of polymer networks
Authors: Zhong Yuanbo , Li Panpan , Wang Xu , Hao Jingcheng
Published: February 2021

Inspired by the habits of amoebas, the sugar-fueled transient liquefaction of covalent adaptable hydrogels is utilized to reconfigure the crosslinked polymer networks, which provides a green way towards the fabrication of multifunctional materials.
Tailored dealloying-driven, graphene-boosted defective rutile TiO2−x for long-term lithium storage
Authors: Chen Yang , Li Zhangfeng , Yang Chaofan , Qiu Dong , He Chengli , Jiang Zhiyu , Cui Xiaoli
Published: February 2021

A tailored low-temperature dealloying approach, involving a new in situ oxidation–reduction mechanism, is proposed to synthesize blue defective rutile TiO2−x directly.
Cobalt- and iron-catalyzed regiodivergent alkene hydrosilylations
Authors: Zhang Sheng , Liao Jia-Shia , Unruh Daniel K. , Li Guigen , Findlater Michael
Published: February 2021

Regiodivergent olefin hydrosilylation products are accessed through a simple change in the metal center. Linear products (anti-Markovnikov) are obtained using cobalt-based catalysts whereas branched (Markovnikov) products result from an iron-based analogue.
Whole genome survey and microsatellite motif identification ofArtemia franciscana
Authors: Jo Euna , Lee Seung Jae , Choi Eunkyung , Kim Jinmu , Lee Sung Gu , Lee Jun Hyuck , Kim Jeong-Hoon , Park Hyun
Published: February 2021

Artemia is an industrially important genus used in aquaculture as a nutritious diet for fish and as an aquatic model organism for toxicity tests. However, despite the significance of Artemia, genomic research remains incomplete and knowledge on its genomic characteristics is insufficient. In particular, Artemia franciscana of North America has been widely used in fisheries of other continents, resulting in invasion of native species. Therefore, studies on population genetics and molecular marker development as well as morphological analyses are required to investigate its population structure and to discriminate closely related species. Here, we used the Illumina Hi-Seq platform to estimate the genomic characteristics of A. franciscana through genome survey sequencing (GSS). Further, simple sequence repeat (SSR) loci were identified for microsatellite marker development. The predicted genome size was ∼867 Mb using K-mer (a sequence of k characters in a string) analysis (K = 17), and heterozygosity and duplication rates were 0.655 and 0.809%, respectively. A total of 421467 SSRs were identified from the genome survey assembly, most of which were dinucleotide motifs with a frequency of 77.22%. The present study will be a useful basis in genomic and genetic research for A. franciscana.
Syllabic Diadochokinesis in Adults With and Without Traumatic Brain Injury: Severity, Stability, and Speech Considerations
Authors: Solomon Nancy Pearl , Brungart Douglas S. , Wince Jessica R. , Abramowitz Jordan C. , Eitel Megan M. , Cohen Julie , Lippa Sara M. , Brickell Tracey A. , French Louis M. , Lange Rael T.
Published: February 2021

Purpose

Syllabic diadochokinesis (DDK) is a standard assessment task for motor speech disorders. This study aimed to compare rate and regularity of DDK according to the presence or absence of traumatic brain injury (TBI) and severity of TBI, examine the stability of DDK over time, and explore associations between DDK and extemporaneous speech.

Method

Military service members and veterans were categorized into three groups: no history of TBI (control), uncomplicated mild TBI (mTBI), and moderate through severe (including penetrating) TBI (msTBI). Participants produced rapid alternating-motion and sequential-motion syllable repetitions during one or two sessions. A semi-automated protocol determined syllabic rate and regularity. Perceptual ratings of selected participants' connected speech samples were compared to DDK results.

Results

Two hundred sixty-three service members and veterans provided data from one session and 69 from two sessions separated by 1.9 years (SD= 1.0). DDKs were significantly slower overall for mTBI and msTBI groups compared to controls. Regularity of productions did not differ significantly across groups. A significant Group × Task interaction revealed that the msTBI group produced sequential-motion syllable repetitions but not alternating-motion repetitions with greater regularity, whereas the opposite occurred for control and mTBI groups. DDK results did not differ significantly between sessions. Perceptual speech analysis for 30 participants, including 20 with atypical or questionable DDK performance, revealed two participants with mildly abnormal speech.

Conclusions

Overall, DDK productions are slower than normal in adults with moderate, severe, and penetrating TBI and are stable over time. Regularity of productions did not differentiate groups, although this result differed according to task. There were surprisingly few people identified with disordered speech, making comparisons to DDK data tenuous, and indicating that dysarthria is a rare complication in a population of adults with mostly uncomplicated mTBI who are not selected from referrals to a speech-language pathology clinic.
Cognitive Flexibility and Effortful Control in School-Age Children With and Without Stuttering Disorders
Authors: Eichorn Naomi , Pirutinsky Steven
Published: February 2021

Purpose

This study compared attention control and flexibility in school-age children who stutter (CWS) and children who do not stutter (CWNS) based on their performance on a behavioral task and parent report. We used a classic attention-shifting paradigm that included manipulations of task goals and timing to test effects of varying demands for flexibility on switching accuracy and speed. We also examined associations between task performance, group, and relevant aspects of temperament.

Method

Participants included 33 children (15 CWS, 18 CWNS) between 8 and 11 years of age. Children sorted stimuli that differed on two dimensions (color and shape) based on sorting rules that varied from block to block or trial to trial. Timing manipulations included intervals of 200-, 600-, or 1,200-ms durations for critical trial components. Temperament data were obtained via the Children's Behavior Questionnaire.

Results

All children showed expected performance costs in response to block and trial manipulations; however, CWS were more affected by task conditions that increased demands for cognitive flexibility. Effects of interval durations also differed by group. Factor scores on the Children's Behavior Questionnaire indicated differences in effortful control between groups; however, this aspect of temperament did not mediate between-groups differences in switching performance.

Conclusions

Findings suggest that stuttering continues to be associated with differences in attention control and flexibility beyond the preschool years. Further research is needed to clarify how these cognitive processes shape the development of stuttering throughout childhood.
Speech Metrics and Samples That Differentiate Between Nonfluent/Agrammatic and Logopenic Variants of Primary Progressive Aphasia
Authors: Haley Katarina L. , Jacks Adam , Jarrett Jordan , Ray Taylor , Cunningham Kevin T. , Gorno-Tempini Maria Luisa , Henry Maya L.
Published: February 2021

Purpose

Of the three currently recognized variants of primary progressive aphasia, behavioral differentiation between the nonfluent/agrammatic (nfvPPA) and logopenic (lvPPA) variants is particularly difficult. The challenge includes uncertainty regarding diagnosis of apraxia of speech, which is subsumed within criteria for variant classification. The purpose of this study was to determine the extent to which a variety of speech articulation and prosody metrics for apraxia of speech differentiate between nfvPPA and lvPPA across diverse speech samples.

Method

The study involved 25 participants with progressive aphasia (10 with nfvPPA, 10 with lvPPA, and five with the semantic variant). Speech samples included a word repetition task, a picture description task, and a story narrative task. We completed acoustic analyses of temporal prosody and quantitative perceptual analyses based on narrow phonetic transcription and then evaluated the degree of differentiation between nfvPPA and lvPPA participants (with the semantic variant serving as a reference point for minimal speech production impairment).

Results

Most, but not all, articulatory and prosodic metrics differentiated statistically between the nfvPPA and lvPPA groups. Measures of distortion frequency, syllable duration, syllable scanning, and—to a limited extent—syllable stress and phonemic accuracy showed greater impairment in the nfvPPA group. Contrary to expectations, classification was most accurate in connected speech samples. A customized connected speech metric—the narrative syllable duration—yielded excellent to perfect classification accuracy.

Discussion

Measures of average syllable duration in multisyllabic utterances are useful diagnostic tools for differentiating between nfvPPA and lvPPA, particularly when based on connected speech samples. As such, they are suitable candidates for automatization, large-scale study, and application to clinical practice. The observation that both speech rate and distortion frequency differentiated more effectively in connected speech than on a motor speech examination suggests that it will be important to evaluate interactions between speech and discourse production in future research.
Performance analysis of power splitting SWIPT‐enabled full duplex cooperative NOMA system with direct link
Authors: V Aswathi , AV Babu
Published: February 2021

This paper considers a full duplex (FD) cooperative non‐orthogonal multiple access system that employs power splitting relaying (PSR)‐based simultaneous wireless information and power transfer (SWIPT) technique, that is, FD‐PSR‐NOMA system. A single cell network is considered consisting of a base station (BS) and two pre‐paired users, where the near user is configured to act as FD relay to assist the BS for information delivery to the far user. It is assumed that the far user implements maximal ratio combining to combine the direct link signal arriving from the BS and the relayed signal from the near user, to exploit the diversity advantage. Analytical expressions are derived for the outage probabilities of the downlink users, system outage probability, and the throughput of the considered network under imperfect successive interference cancellation (i‐SIC). Analytical expressions are also derived for the outage probabilities and throughput of half duplex (HD) cooperative NOMA system under PSR‐based SWIPT, that is, HD‐PSR‐NOMA system. Further, the asymptotic outage probabilities and diversity orders are derived as well. The optimal power allocation factors at the BS that minimize the system outage probabilities of FD/HD‐PSR‐NOMA networks are determined. Extensive simulation results are provided to corroborate the analytical findings.
Learning near‐optimal broadcasting intervals in decentralized multi‐agent systems using online least‐square policy iteration
Authors: Palunko Ivana , Tolić Domagoj , Prkačin Vicko
Published: February 2021

Here, agents learn how often to exchange information with neighbours in cooperative multi‐agent systems (MASs) such that their linear quadratic regulator (LQR)‐like performance indices are minimized. The investigated LQR‐like cost functions capture trade‐offs between the energy consumption of each agent and MAS local control performance in the presence of exogenous disturbances, delayed and noisy data. Agent energy consumption is critical for prolonging the MAS mission and is composed of both control (e.g. acceleration, velocity) and communication efforts. Taking provably stabilizing upper bounds on broadcasting intervals as optimization constraints, an online off‐policy model‐free learning algorithm based on least square policy iteration (LSPI) to minimize the cost function of each agent is employed. Consequently, the obtained broadcasting intervals adapt to the most recent information (e.g. delayed and noisy agents' inputs and/or outputs) received from neighbours whilst provably stabilize the MAS. Chebyshev polynomials are utilized as the approximator in the LSPI whereas Kalman filtering handles sampled, corrupted, and delayed data. Subsequently, convergence and near‐optimality of our LSPI scheme are inspected. The proposed methodology is verified experimentally using an inexpensive motion capture system and nano quadrotors.
Current harmonic elimination for dual three‐phase PMSM based on a spatial analytical model of flux linkage
Authors: Zhong Zaimin , Yin Xing , Zhou Shuihua , Zhen Yongcheng
Published: February 2021

Compared with the conventional three‐phase motors, the dual three‐phase permanent magnet synchronous motors (PMSMs) have many advantages and have been widely used in various drive fields. However, one major disadvantage of these machines is that they are easy to generate large stator current harmonics, which makes it difficult to have an excellent performance in the drive field. To solve this problem, this study introduces a current harmonic elimination method based on a spatial analytical model of flux linkage. The study reconstructed the analytical model of flux linkage from finite element analysis. The analytical model can describe the spatial harmonics of flux linkage by considering the rotor position information. Based on the model, an active feedforward controller was proposed to eliminate current harmonics by actively injecting the corresponding voltage harmonics, the voltage harmonics are calculated by the model of flux linkage. The performance of the proposed method in eliminating current harmonics is verified by simulations and experiments.
Verification of effect of secondary conductor bar on starting characteristics in line‐start type self‐excited wound‐field synchronous motor
Authors: Aoyama Masahiro , Mizuta Takahiro , Ito Kazumasa
Published: February 2021

This study clarifies experimentally the effect of the secondary conductor bar on line‐start characteristics in a line‐start type self‐excited wound‐field synchronous motor. This motor is based on a brushless wound‐field synchronous motor having a rotor winding connected to a diode rectifier circuit. And it has a secondary conductor bar that is independently connected at a pitch of one pole, without end‐ring. First, the operation principle of the proposed motor and its magnetic circuit design are described, and then the details of the prototype for principle verification are clarified. Next, when the combination of the connecting of the secondary conductor bar is changed, an experiment of line‐starting characteristics and measured rotor field current is demonstrated. Consequently, it was clarified that the influence on the synchronous pull‐in, speed ripple, and rotor field current.
System‐level optimal design process of inverter‐fed BLAC motor used for 12–48 V integrated electric brake system
Authors: Hwang Kyu Yun , Kwon Byung Il
Published: February 2021

In this study, to maximise the performance and efficiency of 48 V integrated electric brake (IEB) system, a system‐level optimal design process is proposed for inverter‐driven brushless AC (BLAC) motor, taking into account the available input voltage that varies depending on the motor operating conditions. To get available input voltages, the voltage drops of battery wiring and inverter are reversely calculated from the motor output power. In the optimal design process, the resistance components in the inverter are separated into DC and AC parts, and these are analysed by including the dq equivalent circuit for motor analysis. The battery currents are obtained using the calculated maximum output performance and the loss between the battery and inverter. The proposed design process is applied to the optimal design of the 48 V motor for IEB systems. Also, to reduce the development cost of the 48 V motor, the manufacturing tools of the previously developed 12 V motor are shared. As an optimal design results, it is confirmed that there is an efficiency improvement effect of ∼5% compared to the conventional design of 12–48 V BLAC motor.
Voting technique‐based islanding detection using superimposed phase angle variation
Authors: Kumar‐Phanindra Kumar Ganivada G.P. , Jena‐Premalata Jena P.
Published: February 2021

In this study, a passive islanding detection technique based on the variation in the angles of superimposed sequence components of voltage and current is proposed. The pre‐ and post‐islanding voltage and current superimposed components are derived using the corresponding voltage and current phasors. The angle between the positive and negative sequence voltage and current and the superimposed components of these quantities are derived to take further action. Furthermore, decisions obtained from the angles of different superimposed components are combined using a voting technique to take the final decision with more reliability and accuracy. The scheme does not require the establishment of any threshold and completely relies on the rule base obtained through a simulation study. A microgrid with multiple connection points is simulated using a real‐time digital simulator (RTDS). A hardware‐in‐the‐loop test bench is arranged using a dSPACE DS1104 and RTDS. Numerous test cases are simulated to assess the performance of the proposed technique.
Gene expression technique‐based approach to improve the accuracy of estimating the total generated power by neighbouring photovoltaic systems
Authors: Al‐Hilfi Hasanain A.H. , Shahnia Farhad , Abu‐Siada Ahmed
Published: February 2021

The penetration of photovoltaic systems (PVs) to existing power grids is increasing as they are considered attractive options for electricity generation in distribution networks. This paper focuses on estimating the total power generated by a group of neighbouring PVs, spread over a distribution network using a single pyranometer for measuring the solar irradiance. A new empirical‐based model that employs the Gene Expression Programming (GEP) technique is proposed to correlate the distribution of the PVs and the irradiance measured by the pyranometer and estimate the total power generated by the PVs. The geographic variability reduction index has been considered in developing the proposed model that also employs a Wavelet Transform technique to enhance its accuracy. The effective performance of the proposed model is validated using real data collected by the Solar Project at the University of Queensland, Brisbane, Australia. Results reveal that the proposed technique yields more accurate results when compared with other existing approaches in the literature.
Finding the mechanism of wave energy flux damping in solar pores using numerical simulations
Authors: Riedl J. M. , Gilchrist-Millar C. A. , Van Doorsselaere T. , Jess D. B. , Grant S. D. T.
Published: February 2021

Context. Solar magnetic pores are, due to their concentrated magnetic fields, suitable guides for magnetoacoustic waves. Recent observations have shown that propagating energy flux in pores is subject to strong damping with height; however, the reason is still unclear.

Aims. We investigate possible damping mechanisms numerically to explain the observations.

Methods. We performed 2D numerical magnetohydrodynamic (MHD) simulations, starting from an equilibrium model of a single pore inspired by the observed properties. Energy was inserted into the bottom of the domain via different vertical drivers with a period of 30 s. Simulations were performed with both ideal MHD and non-ideal effects.

Results. While the analysis of the energy flux for ideal and non-ideal MHD simulations with a plane driver cannot reproduce the observed damping, the numerically predicted damping for a localized driver closely corresponds with the observations. The strong damping in simulations with localized driver was caused by two geometric effects, geometric spreading due to diverging field lines and lateral wave leakage.
Discovery of allenyl acetylene, H2CCCHCCH, in TMC-1
Authors: Cernicharo J. , Cabezas C. , Agúndez M. , Tercero B. , Marcelino N. , Pardo J. R. , Tercero F. , Gallego J. D. , López-Pérez J. A. , deVicente P.
Published: February 2021

We present the discovery in TMC-1 of allenyl acetylene, H2CCCHCCH, through the observation of nineteen lines with a signal-to-noise ratio ∼4–15. For this species, we derived a rotational temperature of 7 ± 1 K and a column density of 1.2 ± 0.2 × 1013 cm−2. The other well known isomer of this molecule, methyl diacetylene (CH3C4H), has also been observed and we derived a similar rotational temperature, Tr = 7.0 ± 0.3 K, and a column density for its two states (A and E) of 6.5 ± 0.3 × 1012 cm−2. Hence, allenyl acetylene and methyl diacetylene have a similar abundance. Remarkably, their abundances are close to that of vinyl acetylene (CH2CHCCH). We also searched for the other isomer of C5H4, HCCCH2CCH (1.4-Pentadiyne), but only a 3σ upper limit of 2.5 × 1012 cm−2 to the column density can be established. These results have been compared to state-of-the-art chemical models for TMC-1, indicating the important role of these hydrocarbons in its chemistry. The rotational parameters of allenyl acetylene have been improved by fitting the existing laboratory data together with the frequencies of the transitions observed in TMC-1.
Population dynamics and expansion of Crangonyx pseudogracilis, a potentially invasive amphipod
Authors: Correia Daniela , Banha Filipe , Gama Mafalda , Anastácio Pedro M.
Published: February 2021

One of the main drivers of biodiversity loss is the introduction of exotic invasive species. In 2011, an abundant population of Crangonyx pseudogracilis, a freshwater amphipod native to North America, was detected in Portugal. This study allowed us to better understand its biology, analysing the population dynamics in a temporary river and a small lake for one year, and to follow its expansion. Our results showed that this species reproduces in the temporary river during most of the year, but in the lake only from March to July. Amphipod density decreases from May to October and increases from November to April. As usual, females were larger than males, but the proportion of females was higher than males at both sampling locations. Finally, we noticed a great increase in C. pseudogracilis distribution area in relation to what was observed in 2014, with a diffusion coefficient of 2495.27 km2/year and a spread rate of 26 km/year. However, no overlap was yet detected between native and exotic amphipod species.
Bulk photovoltaic effect in BaTiO3-based ferroelectric oxides: An experimental and theoretical study
Authors: Pal Subhajit , Muthukrishnan S. , Sadhukhan Banasree , N. V. Sarath , Murali D. , Murugavel Pattukkannu
Published: February 2021

The bulk photovoltaic (PV) effect exhibited by non-centrosymmetric systems gained research interest due to the observed large open-circuit voltage. Ferroelectric systems exhibiting anomalous photovoltaic effects are mostly crystallized with multi-phase coexistence. Hence, the computational difficulty in building a multi-phase system restricts the detailed photovoltaic studies through phenomenological and shift current theory. In this work, ferroelectric Ba1−x(Bi0.5K0.5)xTiO3 (BBKT) oxide is designed to crystallize in single-phase tetragonal symmetry with improved polarization characteristics, and it is found to exhibit large PV response. Both experimental and theoretical studies on BBKT samples reveal ∼18% reduction in bandgap compared to the parent BaTiO3. Short-circuit current measured as a function of light intensity and light polarization angle reveal linear and sinusoidal response, respectively. The observed features are in accordance with phenomenological theory. Remarkably, the x = 0.125 sample displays ∼8 times higher open-circuit voltage (7.39 V) than the parent compound. The enhanced PV effect is attributed to the large shift current along the z direction as evidenced by the additional charge-center shift of the valence band occupied by the O-2p orbital and the conduction band occupied by the Bi-6p orbital. Notably, the degenerate Bi-pz state at the conduction band minimum in BBKT favors the large shift current response in the z direction.
Ultrasensitive flexible magnetoelectric sensor
Authors: Yang Nana , Wu Hanzhou , Wang Shidong , Yuan Guoliang , Zhang Ji , Sokolov Oleg , Bichurin M. I. , Wang Ke , Wang Yaojin
Published: February 2021

Ever-evolving advances in flexible magnetic sensors are promising to fuel technological developments in the fields of touchless human–machine interaction, implantable medical diagnosis, and magnetoreception for artificial intelligence. However, the realization of highly flexible and extremely sensitive magnetic sensors remains a challenge. Here, we report a cost-effective, flexible, and ultra-sensitive heterostructural magnetoelectric (ME) sensor consisting of piezoelectric Pb(Zr0.52Ti0.48)O3 (PZT) thick films and Metglas foils. The flexible sensor exhibits a strong ME coefficient of 19.3 V cm−1 Oe−1 at low frequencies and 280.5 V cm−1 Oe−1 at resonance due to the exceptionally high piezoelectric coefficient d33 ∼ 72 pC N−1 of the constituent PZT thick films. The flexible ME sensor possesses not only ultrahigh sensitivities of 200 nT at low frequencies and 200 pT at resonance but also shows an excellent mechanical endurance. Through 5000 bending cycles (radii of ∼1 cm), the sensors showed no fatigue-induced performance degradation. This ultrasensitive flexible sensor provides a platform capable of sensing and responding to external magnetic fields and will find applications in soft robotics, wearable healthcare monitoring, and consumer electronics.
Gain-type optomechanically induced absorption and precise mass sensor in a hybrid optomechanical system
Authors: Liu Shaopeng , Liu Bo , Wang Junfeng , Zhao Lilong , Yang Wen-Xing
Published: February 2021

The sign of quantum interference (constructive or destructive) based on cavity optomechanics is crucial for observing quantum phenomena and designing high-sensitivity sensors with an integrable structure. Here, we propose an efficient scheme to generate constructive interference and optomechanically induced absorption (OMIA) in a hybrid atom–cavity optomechanical system. Using experimentally achievable parameters, we theoretically demonstrate that a gain-type OMIA dip with the extremely narrow linewidth and the enhanced spectral intensity can be modulated by an assisted atom that is excited by an external control field. More importantly, we report that a precise mass sensor is achieved by employing an observable correlation between the OMIA dip and the added mass deposited on the mechanical object. With the help of the back-action cooling of the mechanical object, we identify that the detection sensitivity and minimum resolution of the mass sensor can reach 3.14MHz/ng and 1fg, respectively.