bluuebunny/crossref_metadata_2025 huggingface dataset:
The long noncoding RNA HOTAIRM1 controlled by AML1 enhances glucocorticoid resistance by activating RHOA/ROCK1 pathway through suppressing ARHGAP18
Authors: Liang Liang , Gu Wenbin , Li Meng , Gao Ran , Zhang Xin , Guo Chongye , Mi Shuangli
Published: July 2021

Acquired resistance to glucocorticoids (GCs) is an obstacle to the effective treatment of leukemia, but the molecular mechanisms of steroid insensitivity have not been fully elucidated. In this study, we established an acquired GC-resistant leukemia cell model and found a long noncoding RNA, HOTAIRM1, was overexpressed in the resistant cells by transcriptional profiling, and was higher expressed in patients with poor prognosis. The whole-genome-binding sites of HOTAIRM1 were determined by ChIRP-seq (chromatin isolation by RNA purification combined with sequencing) analysis. Further study determined that HOTAIRM1 bound to the transcriptional inhibitory region of ARHGAP18 and repressed the expression of ARHGAP18, which led to the increase of RHOA/ROCK1 signaling pathway and promoted GC resistance through antiapoptosis of leukemia cells. The inhibition of ROCK1 in GC-resistant cells could restore GCs responsiveness. In addition, HOTAIRM1 could also act as a protein sequester to prevent transcription factor AML1(acute myeloid leukemia 1) from binding to the regulatory region of ARHGAP18 by interacting with AML1. At last, we also proved AML1 could directly activate the expression of HOTAIRM1 through binding to the promoter of HOTAIRM1, which enriched the knowledge on the regulation of lncRNAs. This study revealed epigenetic causes of glucocorticoid resistance from the perspective of lncRNA, and laid a foundation for the optimization of glucocorticoid-based leukemia treatment strategy in clinic.
Restoration of RPGR expression in vivo using CRISPR/Cas9 gene editing
Authors: Gumerson Jessica D. , Alsufyani Amal , Yu Wenhan , Lei Jingqi , Sun Xun , Dong Lijin , Wu Zhijian , Li Tiansen
Published: July 2021

Mutations in the gene for Retinitis Pigmentosa GTPase Regulator (RPGR) cause the X-linked form of inherited retinal degeneration, and the majority are frameshift mutations in a highly repetitive, purine-rich region of RPGR known as the OFR15 exon. Truncation of the reading frame in this terminal exon ablates the functionally important C-terminal domain. We hypothesized that targeted excision in ORF15 by CRISPR/Cas9 and the ensuing repair by non-homologous end joining could restore RPGR reading frame in a portion of mutant photoreceptors thereby correcting gene function in vivo. We tested this hypothesis in the rd9 mouse, a naturally occurring mutant line that carries a frameshift mutation in RPGRORF15, through a combination of germline and somatic gene therapy approaches. In germline gene-edited rd9 mice, probing with RPGR domain-specific antibodies demonstrated expression of full length RPGRORF15 protein. Hallmark features of RPGR mutation-associated early disease phenotypes, such as mislocalization of cone opsins, were no longer present. Subretinal injections of the same guide RNA (sgRNA) carried in AAV sgRNA and SpCas9 expression vectors restored reading frame of RPGRORF15 in a subpopulation of cells with broad distribution throughout the retina, confirming successful correction of the mutation. These data suggest that a simplified form of genome editing mediated by CRISPR, as described here, could be further developed to repair RPGRORF15 mutations in vivo.
NiFeOx decorated Ge-hematite/perovskite for an efficient water splitting system
Authors: Yoon Ki-Yong , Park Juhyung , Jung Minsu , Ji Sang-Geun , Lee Hosik , Seo Ji Hui , Kwak Myung-Jun , Il Seok Sang , Lee Jun Hee , Jang Ji-Hyun
Published: July 2021

To boost the photoelectrochemical water oxidation performance of hematite photoanodes, high temperature annealing has been widely applied to enhance crystallinity, to improve the interface between the hematite-substrate interface, and to introduce tin-dopants from the substrate. However, when using additional dopants, the interaction between the unintentional tin and intentional dopant is poorly understood. Here, using germanium, we investigate how tin diffusion affects overall photoelectrochemical performance in germanium:tin co-doped systems. After revealing that germanium is a better dopant than tin, we develop a facile germanium-doping method which suppresses tin diffusion from the fluorine doped tin oxide substrate, significantly improving hematite performance. The NiFeOx@Ge-PH photoanode shows a photocurrent density of 4.6 mA cm−2 at 1.23 VRHE with a low turn-on voltage. After combining with a perovskite solar cell, our tandem system achieves 4.8% solar-to-hydrogen conversion efficiency (3.9 mA cm−2 in NiFeOx@Ge-PH/perovskite solar water splitting system). Our work provides important insights on a promising diagnostic tool for future co-doping system design.
Deep carbon cycle constrained by carbonate solubility
Authors: Farsang Stefan , Louvel Marion , Zhao Chaoshuai , Mezouar Mohamed , Rosa Angelika D. , Widmer Remo N. , Feng Xiaolei , Liu Jin , Redfern Simon A. T.
Published: July 2021

Earth’s deep carbon cycle affects atmospheric CO2, climate, and habitability. Owing to the extreme solubility of CaCO3, aqueous fluids released from the subducting slab could extract all carbon from the slab. However, recycling efficiency is estimated at only around 40%. Data from carbonate inclusions, petrology, and Mg isotope systematics indicate Ca2+ in carbonates is replaced by Mg2+ and other cations during subduction. Here we determined the solubility of dolomite [CaMg(CO3)2] and rhodochrosite (MnCO3), and put an upper limit on that of magnesite (MgCO3) under subduction zone conditions. Solubility decreases at least two orders of magnitude as carbonates become Mg-rich. This decreased solubility, coupled with heterogeneity of carbon and water subduction, may explain discrepancies in carbon recycling estimates. Over a range of slab settings, we find aqueous dissolution responsible for mobilizing 10 to 92% of slab carbon. Globally, aqueous fluids mobilise $${35}_{-17}^{+20}$$

35

−
17

+
20

% ($${27}_{-13}^{+16}$$

27

−
13

+
16

Mt/yr) of subducted carbon from subducting slabs.
Tumor-killing nanoreactors fueled by tumor debris can enhance radiofrequency ablation therapy and boost antitumor immune responses
Authors: Yang Zhijuan , Zhu Yujie , Dong Ziliang , Li Wei , Yang Nailin , Wang Xianwen , Feng Liangzhu , Liu Zhuang
Published: July 2021

Radiofrequency ablation (RFA) is clinically adopted to destruct solid tumors, but is often incapable of completely ablating large tumors and those with multiple metastatic sites. Here we develop a CaCO3-assisted double emulsion method to encapsulate lipoxidase and hemin with poly(lactic-co-glycolic acid) (PLGA) to enhance RFA. We show the HLCaP nanoreactors (NRs) with pH-dependent catalytic capacity can continuously produce cytotoxic lipid radicals via the lipid peroxidation chain reaction using cancer cell debris as the fuel. Upon being fixed inside the residual tumors post RFA, HLCaP NRs exhibit a suppression effect on residual tumors in mice and rabbits by triggering ferroptosis. Moreover, treatment with HLCaP NRs post RFA can prime antitumor immunity to effectively suppress the growth of both residual and metastatic tumors, also in combination with immune checkpoint blockade. This work highlights that tumor-debris-fueled nanoreactors can benefit RFA by inhibiting tumor recurrence and preventing tumor metastasis.
Single-cell microRNA sequencing method comparison and application to cell lines and circulating lung tumor cells
Authors: Hücker Sarah M. , Fehlmann Tobias , Werno Christian , Weidele Kathrin , Lüke Florian , Schlenska-Lange Anke , Klein Christoph A. , Keller Andreas , Kirsch Stefan
Published: July 2021

Molecular single cell analyses provide insights into physiological and pathological processes. Here, in a stepwise approach, we first evaluate 19 protocols for single cell small RNA sequencing on MCF7 cells spiked with 1 pg of 1,006 miRNAs. Second, we analyze MCF7 single cell equivalents of the eight best protocols. Third, we sequence single cells from eight different cell lines and 67 circulating tumor cells (CTCs) from seven SCLC patients. Altogether, we analyze 244 different samples. We observe high reproducibility within protocols and reads covered a broad spectrum of RNAs. For the 67 CTCs, we detect a median of 68 miRNAs, with 10 miRNAs being expressed in 90% of tested cells. Enrichment analysis suggested the lung as the most likely organ of origin and enrichment of cancer-related categories. Even the identification of non-annotated candidate miRNAs was feasible, underlining the potential of single cell small RNA sequencing.
Metastatic heterogeneity of the consensus molecular subtypes of colorectal cancer
Authors: Eide Peter W. , Moosavi Seyed H. , Eilertsen Ina A. , Brunsell Tuva H. , Langerud Jonas , Berg Kaja C. G. , Røsok Bård I. , Bjørnbeth Bjørn A. , Nesbakken Arild , Lothe Ragnhild A. , Sveen Anita
Published: July 2021

Gene expression-based subtypes of colorectal cancer have clinical relevance, but the representativeness of primary tumors and the consensus molecular subtypes (CMS) for metastatic cancers is not well known. We investigated the metastatic heterogeneity of CMS. The best approach to subtype translation was delineated by comparisons of transcriptomic profiles from 317 primary tumors and 295 liver metastases, including multi-metastatic samples from 45 patients and 14 primary-metastasis sets. Associations were validated in an external data set (n = 618). Projection of metastases onto principal components of primary tumors showed that metastases were depleted of CMS1-immune/CMS3-metabolic signals, enriched for CMS4-mesenchymal/stromal signals, and heavily influenced by the microenvironment. The tailored CMS classifier (available in an updated version of the R package CMScaller) therefore implemented an approach to regress out the liver tissue background. The majority of classified metastases were either CMS2 or CMS4. Nonetheless, subtype switching and inter-metastatic CMS heterogeneity were frequent and increased with sampling intensity. Poor-prognostic value of CMS1/3 metastases was consistent in the context of intra-patient tumor heterogeneity.
Multiscale criticality measures as general-purpose gauges of proper brain function
Authors: Fekete Tomer , Hinrichs Hermann , Sitt Jacobo Diego , Heinze Hans-Jochen , Shriki Oren
Published: July 2021

The brain is universally regarded as a system for processing information. If so, any behavioral or cognitive dysfunction should lend itself to depiction in terms of information processing deficiencies. Information is characterized by recursive, hierarchical complexity. The brain accommodates this complexity by a hierarchy of large/slow and small/fast spatiotemporal loops of activity. Thus, successful information processing hinges upon tightly regulating the spatiotemporal makeup of activity, to optimally match the underlying multiscale delay structure of such hierarchical networks. Reduced capacity for information processing will then be expressed as deviance from this requisite multiscale character of spatiotemporal activity. This deviance is captured by a general family of multiscale criticality measures (MsCr). MsCr measures reflect the behavior of conventional criticality measures (such as the branching parameter) across temporal scale. We applied MsCr to MEG and EEG data in several telling degraded information processing scenarios. Consistently with our previous modeling work, MsCr measures systematically varied with information processing capacity: MsCr fingerprints showed deviance in the four states of compromised information processing examined in this study, disorders of consciousness, mild cognitive impairment, schizophrenia and even during pre-ictal activity. MsCr measures might thus be able to serve as general gauges of information processing capacity and, therefore, as normative measures of brain health.
Enantioselective “organocatalysis in disguise” by the ligand sphere of chiral metal-templated complexes
Authors: Larionov Vladimir A. , Feringa Ben L. , Belokon Yuri N.
Published: July 2021

An overview about the principles, applications and perspectives on the catalytic use of chiral metal-templated complexes that operate as “chiral organocatalysts in disguise” is presented.
Recent advances in activating surface reconstruction for the high-efficiency oxygen evolution reaction
Authors: Gao Likun , Cui Xun , Sewell Christopher D. , Li Jian , Lin Zhiqun
Published: July 2021

The recent progress in activating surface reconstruction by integrating advanced characterizations with theoretical calculations for high-efficiency oxygen evolution reaction is reviewed.
Enhanced electrochemical biosensing on gold electrodes with a ferri/ferrocyanide redox couple
Authors: Lee Seowon , Kim Won Jae , Chung Minsub
Published: July 2021

Ferricyanide with phosphate buffer is revealed to greatly promote the dissolution of gold electrodes. Stable electrochemical measurement with Fe(CN)6 is found to be possible with Tris buffer.
Defect engineering in perovskite oxide thin films
Authors: Sun Yunlong , Yang Jack , Li Sean , Wang Danyang
Published: July 2021

The modulation of properties in perovskite oxide thin films by defect engineering.
Hollow cuboidal MnCo2O4 coupled with nickel phosphate: a promising oxygen evolution reaction electrocatalyst
Authors: Shah Adit Kumar , Bhowmick Sourav , Gogoi Devipriya , Peela Nageswara Rao , Qureshi Mohammad
Published: July 2021

Growth of unique hierarchical hollow-cuboidal complex metal oxide directly on the substrate coupled with nickel phosphate.
A nitrogen-doped asymmetric phenalenyl with a zwitterionic ground state
Authors: Miao Fang , Chen Hanjiao , Moles Quintero Sergio , Xue Guodong , Casado Juan , Zheng Yonghao
Published: July 2021

Asymmetric azaphenalenyl radicals! A unique strategy from Blatter radicals is used to access rare asymmetric phenalenyl radicals.
Design and enantioselective synthesis of 3-(α-acrylic acid) benzoxaboroles to combat carbapenemase resistance
Authors: Xiao You-Cai , Chen Xiao-Pan , Deng Ji , Yan Yu-Hang , Zhu Kai-Rong , Li Gen , Yu Jun-Lin , Brem Jürgen , Chen Fener , Schofield Christopher J. , Li Guo-Bo
Published: July 2021

An organocatalytic MBH cascade reaction was developed to construct new 3-(α-acrylic acid) benzoxaboroles, designed to mimic ‘anchoring’ pharmacophore features of carbapenems, with the aim of helping overcome carbapenemase resistance.
Acyl silane directed Cp*Rh(iii)-catalysed alkylation/annulation reactions
Authors: Priebbenow Daniel L. , Hua Carol
Published: July 2021

Studies into the Cp*Rh(iii)-catalysed hydroarylation of alkenes with aryl acyl silanes led to the discovery of a new synthetic strategy to access unique silicon derived indene frameworks.
Biomimetic calcium-inactivated ion/molecular channel
Authors: Li Minmin , Cao Yuchen , Zhang Xin , Wang Dongdong , Qian Shengxu , Li Guodong , Zhang Fusheng , Xiong Yuting , Qing Guangyan
Published: July 2021

A phosphopeptide-modified nanochannel demonstrates the reversible Ca2+-induced inactivation effect toward the ion flow and molecular transport through the nanochannel.
Rhodium catalyzed multicomponent dehydrogenative annulation: one-step construction of isoindole derivatives
Authors: Lyu Hairong , Quan Yangjian , Cheng Biao , Xie Zuowei
Published: July 2021

A strategy for one-pot synthesis of isoindoles is described via an effective catalytic multicomponent dehydrogenative annulation of diarylimines, vinyl ketones and primary amines.
Selective, radical-free activation of benzylic C–H bonds in methylarenes
Authors: Chan Antony P. Y. , Jakoobi Martin , Wang Chenxu , Tian Yancong , Halcovitch Nathan , Boulatov Roman , Sergeev Alexey G.
Published: July 2021

We report the selective oxidative addition of benzylic C–H bonds in industrially important methylarenes using rare η4-arene iridium complexes.
The characteristics of Ib diamond crystals synthesized in a Fe–Ni–C system with different SiC contents
Authors: Wang Yongkui , Wang Zhiwen , Lu Zhiyun , Cai Zhenghao , Fang Shuai , Zhao Hongyu , Jia Hongsheng , Ma Hongan , Chen Liangchao , Jia Xiaopeng
Published: July 2021

The influence of different SiC doping contents on the synthesis of diamond crystals in the Fe–Ni–C system was investigated.
First global analysis of the GSK database of small molecule crystal structures
Authors: Kalash Leen N. , Cole Jason C. , Copley Royston C. B. , Edge Colin M. , Moldovan Alexandru A. , Sadiq Ghazala , Doherty Cheryl L.
Published: July 2021

Analysis of the molecular and structural features of the GSK crystal structure database and Cambridge Structural Database leads to improved reliability in hydrogen bond propensity models for pharmaceutical polymorphs.
Imaging defects in vanadium(iii) oxide nanocrystals using Bragg coherent diffractive imaging
Authors: Barringer Zachary , Jiang Jie , Shi Xiaowen , Schold Elijah , Pateras Anastasios , Cipiccia S. , Rau C. , Shi Jian , Fohtung Edwin
Published: July 2021

Here, Fohtung and colleagues capture nanoscale three-dimensional defects in vanadium(iii) oxide nanocrystals using X-ray Bragg coherent diffractive imaging.
Selection rule for Raman spectra of two-dimensional materials using circularly-polarized vortex light
Authors: Saito Riichiro , Ukhtary Muhammad Shoufie , Wang Sake , Hung Nguyen Tuan
Published: July 2021

Conservation of spin and orbital angular momenta of circularly-polarized vortex light is discussed for Raman spectra of two-dimensional materials.
Fabrication of high quality electrochemical SERS (EC-SERS) substrates using physical vapour deposition
Authors: Farling Carolyn G. , Stackaruk Mary C. , Pye Cory C. , Brosseau Christa L.
Published: July 2021

Silver-coated screen-printed electrodes (SPEs) are an efficient and inexpensive substrate for electrochemical surface-enhanced Raman spectroscopy (EC-SERS) studies.
Surface oxidation-induced restructuring of liquid Pd–Ga SCALMS model catalysts
Authors: Wittkämper Haiko , Maisel Sven , Moritz Michael , Grabau Mathias , Görling Andreas , Steinrück Hans-Peter , Papp Christian
Published: July 2021

We have examined model systems for the recently reported Pd–Ga Supported Catalytically Active Liquid Metal Solutions (SCALMS) catalysts using near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) under oxidizing conditions.
A facile strategy for third-component selection in non-fullerene acceptor-based ternary organic solar cells
Authors: Li Yun , Cai Yunhao , Xie Yuanpeng , Song Junhua , Wu Hongbo , Tang Zheng , Zhang Jie , Huang Fei , Sun Yanming
Published: July 2021

We synthesized three fluorinated non-fullerene acceptors, BTP-F, Y6-F and L8-BO-F, and further used them as the third components to fabricate ternary organic solar cells. The PM6:BTP-eC9:BTP-F ternary device yielded a high efficiency of 18.45%.
Towards sustainable continuous production of azo dyes: possibilities and techno-economic analysis
Authors: Shukla Chinmay A. , Kute Mahesh S. , Kulkarni Amol A.
Published: July 2021

A scalable continuous process for synthesizing azo dyes using a bubble column reactor is reported. This process shows yields >92% and requires ∼40% less water than a typical industrial batch process.
Sustainable one-pot synthesis of strontium phosphate nanoparticles with effective charge carriers for the photocatalytic degradation of carcinogenic naphthylamine derivative
Authors: Arumugam Balamurugan , Muthukutty Balamurugan , Chen Shen-Ming , Amanulla Baishnisha , Ramaraj Sayee Kannan
Published: July 2021

In this work, a sustainable one-pot precipitation method was applied for synthesizing strontium phosphate nanoparticles (SrPO NPs), which can be utilized as effective charge separation photocatalysts for the degradation of oncogenic naphthylamine derivatives (congo red).
Theoretical insight into dihydrogen activation with β-diketiminato ligand supported Group 13 and 14 elements: mechanism and activity difference
Authors: Li Weiyi , Li Cai-Qin , Zhang Xiaoyan , Xia Chuanxi , Leng Geng
Published: July 2021

Mechanisms and activity difference for dihydrogen activation with the BDI-supported Group 13 and 14 elements are comparatively studied.
A hybrid nanosensor based on novel fluorescent iron oxide nanoparticles for highly selective determination of Hg2+ions in environmental samples
Authors: Tümay Süreyya Oğuz , Şanko Vildan , Şenocak Ahmet , Demirbas Erhan
Published: July 2021

Novel fluorescent iron oxide nanoparticles were prepared for the determination of Hg2+in real samples. The fluorescence behaviors of the sensor were examined using absorption and fluorescence (steady-state, time-resolved, 3-D, EEM) spectroscopies.
In/ZnO@C hollow nanocubes for efficient electrochemical reduction of CO2 to formate and rechargeable Zn–CO2 batteries
Authors: Teng Xue , Niu Yanli , Gong Shuaiqi , Xu Mingze , Liu Xuan , Ji Lvlv , Chen Zuofeng
Published: July 2021

In/ZnO@C hollow nanocubes derived from In(OH)3-doped Zn-MOFs were developed for the electrochemical reduction of CO2 to formate and rechargeable aqueous Zn–CO2 batteries.
Synthesis, structure elucidation and functionalization of sulfonamide [2]catenanes
Authors: Wang Yu , Lu Shuai , Wang Xu-Qing , Niu Yan-Fei , Wang Heng , Wang Wei
Published: July 2021

A pyrene-functionalized [2]catenane with switchable optical output was constructed through a novel sulfonamide [2]catenane synthesized by a self-templation approach.
Cu(i)- and Au(i)-catalyzed regioselective oxidation of diynes: divergent synthesis of N-heterocycles
Authors: Shen Wen-Bo , Zhang Ting-Ting , Zhang Meng , Wu Jing-Jing , Jiang Xiao-Lei , Ru Guang-Xin , Gao Guang-Qin , Zhu Xiu-Hong
Published: July 2021

The efficient and divergent construction of two types of valuable N-heterocycle is achieved easily, with the first example of the generation of α-oxo copper carbenes via copper-catalyzed oxidation of non-polarized alkynes.
Mesoporous calcium silicate nanoparticles for superficial dental tissue reconstruction, in vitro and in vivo
Authors: Gao Yixue , Huang Pin , Chen Ruiying , Wang Man , Wang Yining , Sa Yue , Jiang Tao
Published: July 2021

MCSNs could be used as a promising biomaterial for occluding the dentinal tubules in vitro and in vivo. Also, the outstanding drug delivery and antibacterial properties enable it to carry antibiotics easily for inhibiting deeper pulp infection.
Catalyst-free synthesis of novel 1,5-benzodiazepines and 3,4-dihydroquinoxalines using isocyanide-based one-pot, three- and four-component reactions
Authors: Mohlala Reagan L. , Coyanis E. Mabel , Fernandes Manuel A. , Bode Moira L.
Published: July 2021

Reaction of benzimidazole derivatives with an isocyanide and acetone led to tricyclic benzodiazepine derivatives or dihydroquinoxalines depending on the nature of the substituents R1 and R2.
6-Halo-2-pyridone as an efficient organocatalyst for ester aminolysis
Authors: Yamada Takeshi , Watanabe Yusuke , Okamoto Sentaro
Published: July 2021

6-Halo-2-pyridones effectively catalyse ester aminolysis as bifunctional catalysts. This reaction did not require any special conditions and was operationally convenient.
Efficient continuous-flow synthesis of long-chain alkylated naphthalene catalyzed by ionic liquids in a microreaction system
Authors: Yang Tian , Wang Fajun , Huang Jinpei , Da Ling Si , Liu Suli , Zhang Angui , Wang Yundong , Xu Jianhong
Published: July 2021

A microreaction system for the synthesis of long-chain alkylated naphthalene is presented, indicating a high yield of alkylated naphthalene (>99%) could be obtained in 60 s at mild temperature (30 °C) within 5 cycles of ionic liquid catalyst reuse.
Continuous biphasic chemical processes in a four-phase segmented flow reactor
Authors: Volk Amanda A. , Epps Robert W. , Yonemoto Daniel , Castellano Felix N. , Abolhasani Milad
Published: July 2021

A four-phase segmented flow regime for continuous biphasic reaction processes is introduced, characterized over 1500 automatically conducted experiments, and used for biphasic ligand exchange of CdSe quantum dots.
Case study analysis of reflective essays by chemistry post-secondary students within a lab-based community service learning water project
Authors: Ho Karen , Smith Sahara R. , Venter Catharina , Clark Douglas B.
Published: July 2021

Intentional reflection is a key component of Community Service Learning (CSL) as it guides students to integrate knowledge of theory with experience in practice. A semester-long chemistry curriculum with an integrated CSL intervention was implemented in a Canadian university to investigate how reflection in the laboratory setting enhances post-secondary students’ (n= 14) conscious awareness of their learning and their attitudes toward having reflection as part of a course. In typical chemistry laboratories, students follow cookbook recipes from the lab manual and are assessed through written lab reports. These lab reports are similar to a technical report with scientific writing where the design aims to communicate scientific information to other scientists. A case study was conducted with reflective essays, focus group interviews, and student observation to analyze qualitatively how students' attitudes changed in their learning over the course of the CSL activity and how they engaged in this type of reflection. The expected audience that may be interested in this study are those involved in teaching chemistry in higher education and those that are interested in Community Service Learning and experiential learning. The results demonstrate that science students are able to articulate their academic growth, civic engagement, and personal growth through reflective pieces. Furthermore, the reflective pieces support self-regulated learning with a positive engagement and attitude over time. The results support the integration of reflective pieces in laboratory settings.
Rigidochromism by imide functionalisation of an aminomaleimide fluorophore
Authors: Husband Jonathan T. , Xie Yujie , Wilks Thomas R. , Male Louise , Torrent-Sucarrat Miquel , Stavros Vasilios G. , O'Reilly Rachel K.
Published: July 2021

In this study, by systematic tuning of imide substituent a maleimides dye with sensitivity to its solid-state environment was investigated.
Porous biochar nanosheets loaded with Fe3C particles accelerate electrochemical reactions and their applications in Li–S batteries
Authors: Wang Xuri , Zhang Yawen , Chang Qihong , Wu Yaqin , Lei Weixin , Zou Youlan , Ma Zengsheng , Pan Yong
Published: July 2021

Schematic diagram of the manufacturing process and mechanism of Fe3C-GB@S.
Strong sensitivity enhancement in lifetime-based luminescence thermometry by co-doping of SrTiO3:Mn4+ nanocrystals with trivalent lanthanide ions
Authors: Piotrowski W. M. , Trejgis K. , Dramicanin M. , Marciniak L.
Published: July 2021

The co-doping of SrTiO3:Mn4+ luminescent nanocrystals with trivalent lanthanide ions (Ln3+ = Lu3+, Tm3+, Er3+, Ho3+, Dy3+, Eu3+, and La3+) is demonstrated as a new strategy for significant sensitivity improvement of lifetime-based luminescent thermometers.
Ultrasound: Reliability of a Pocket-Sized System in the Assessment of Swallowing
Authors: Winiker Katharina , Burnip Emma , Gozdzikowska Kristin , Hernandez Esther Guiu , Hammond Rebecca , Macrae Phoebe , Thomas Paige , Huckabee Maggie-Lee
Published: July 2021

Purpose

Ultrasound imaging offers a noninvasive adjunct to clinical swallowing assessment. Published reliability of sophisticated ultrasound systems is promising; however, no data exist for reliability using more affordable, pocket-sized devices. This study explored intrarater, interrater, and test–retest reliability of swallowing measures acquired with pocket-sized ultrasound technology.

Method

Five participants collected measures of swallowing from 20 healthy individuals using the Clarius ultrasound. Hyoid excursion and thyrohyoid approximation were derived during saliva, liquid, and puree swallowing. The cross-sectional area of the floor of mouth muscles and tongue thickness were obtained at rest. Measures were collected at two occasions minimum 11 days apart. Reliability was assessed for the entire process of data acquisition including scanning and online measurement, and for offline measurement of saved images.

Results

For most measures, reliability was poor (ICC [intraclass correlation coefficient] < .50) to moderate (ICC = .50–.75) for the entire process of data acquisition and poor to good (ICC > .75) when measuring saved images.

Conclusion

Further work is needed to elucidate whether our study findings apply to the Clarius system only or the data suggest a general limitation of pocket-sized ultrasound technology.
The Necessity of Application of Frequency Electric Drives for Irrigation Systems
Authors: Kaidar A.B. , Shapkenov B.K. , Markovsky V.P. , Kislov A.P. , Borzykh A.O.
Published: July 2021

The article substantiates the possibility of using frequency drives in agricultural production, shows promising areas of their application, shows the positive qualities of frequency drives, which make it possible to confidently compete with gear drives that are widespread in agriculture. It is indicated that the use of a frequency electric drive can reduce the current and mechanical loads due to soft start. Due to the additional control inputs of the frequency converter, it is possible to synchronize the processes on the load or set the change factors for some values depending on others. For example, to establish the dependence of the speed of the irrigation pumping system on the pressure in the system. The process will be optimized because as the load on the pump increases, the flow will increase. Recommendations are given on the choice of the power of the frequency converter, taking into account the rated currents and voltage of the converter and the motor. Recommendations are given on the choice of the power of the frequency converter, taking into account the rated currents and voltage of the converter and the motor. The advantages of starting and braking electric drives with frequency regulation are shown.
Selection of the optimum device parameters for constant magnetic field generation
Authors: Khazieva Regina , Ivanov Maksim
Published: July 2021

The aim of the work is to develop a device design for creating constant magnetic fields and select its parameters, select an electrical circuit for powering the device and determine how the energy efficiency of the device changes with an increase in its overall dimensions. When solving the problem, the KOMPAS-3D three-dimensional modeling system was used, the magnetic field induction was calculated using the Pascal ABC programming system, the optimal device parameters were selected using the Microsoft Excel program. Calculations have shown that the coefficient taking into account the inhomogeneous distribution of the magnetic field in the device is 0.883. The optimum ratio between the height and the radius of the cylinder, along which the emulsion flows, is h = r √ 20 hr. Using the KOMPAS-3D three-dimensional modeling system, a model of the device under development was built taking into account the obtained relationships. When using a circuit with an uncontrolled rectifier and autotransformer, the power consumed by the device is 2.67 times lower than the power consumed by the device when using a circuit with a controlled rectifier and a transformer. Energy efficiency increases significantly with the increase in device performance.
Effective energy storage power control to extend the acceptable range of generator frequency in distributed generation
Authors: Ilyushin Pavel , Filippov Sergey , Kulikov Aleksandr
Published: July 2021

Gas-turbine and gas-piston generator sets (GS) are widely used at distributed generation (DG) facilities. International GS manufacturers configure relay protections (RP) in a way that narrows the acceptable range (AR) and causes properly functioning RPs to effect unnecessary disconnections. It has been shown that the worst disturbances are observed when a microgrid that carries a DG facility is islanded, and power imbalance occurs; when motors start in groups; when the GS’s shed 95% of their output; and when a 3-phase short-circuit occurs in an islanded grid segment. Energy storage units (ESU) are the most recent and highly successful solution to many problems of power engineering. The authors hereof have developed a method that controls active and reactive power of an ESU independently to avoid unnecessary GS disconnections that would otherwise be caused by a short-term deviation in frequency; this will help reliably deliver electricity to the users of an islanded microgrid. Simulation results show that the use of ESUs helps to effectively extend the acceptable range for generator sets. There are recommendations on drawing technical requirements to ES. An important advantage of the proposed ESU power control method is that it does not need to adjust ES-received control actions (CA) online for frequency deviation.
Energy interaction of two-link converters of a multi-motor drive with mains supply
Authors: Ganiev Rishat
Published: July 2021

It is known that the total power electrical loads consume from the mains is the sum of their two components – active and reactive. Most electric drives of modern industrial enterprises consume up to 40% of reactive energy in relation to the total energy. This results in an increased full power consumption thereby increasing the load on the supply mains. Modern electric drives are built as follows: supply mains – rectifier-direct current link-inverter – asynchronous motor. The total power consumption is at the "mains-rectifier" interface, where the required active power factor of the converter can be formed. The higher the active power factor, the lower the reactive component in the total consumed energy. Thus, the paper proposes a solution to the problem of building highly efficient converting devices for powering electric motors with the required power factor. In particular, the paper discusses possible increase in the power factor of the electric drive mains input with two-link frequency converters based on active (controlled) rectifiers with current and voltage inverters. The author proposes new ways to control active rectifiers based on the use of AC rectifying devices with fully controlled GTO, GCT thyristors, as well as pulse-width control IGBT transistors. The paper offers options for the construction of these rectifiers and the results of modeling the proposed control methods, confirming a decrease in the passive components of the mains current, and, as a consequence, an increase in the mains input power factor. The simulation results were obtained in MathLab 10, and are the basis for confirming the method of increasing the active power factor at the mains input of a controlled two-link frequency converter.
Method for producing low-viscosity marine fuel oil
Authors: Mendybayev Rafail , Uteuliyev Nurlan , Mendybayeva Diana , Akhmetov Sairanbek , Bukanova Aigul
Published: July 2021

Low-viscosity marine fuel oil that is obtained from the products of residual raw materials and middle distillate fractions of oil is intended for use in ship engines instead of a diesel fuel. A real-world application of this new composition is of great importance A proposed new composition of low-viscosity marine fuel oil is created by compounding a mixture of oil distillates in accordance with the following parameters. The oil distillate mixture should contain a vacuum distillate fraction 420-490°C, a vacuum distillate fraction 350-420°C and a straight-run diesel fraction 180-350°C taken in certain ratios. This study presents the new fuel composition and its technical advantages over previous analogues. The benefits include improvements in the coking properties and storage stability due to the stability in the pour point indicator.
Digital transformation of energy in the Russian Federation: project approach, realities and prospects
Authors: Kulkova Varvara , Khusainova Ekaterina , Serkina Nina , Dolonina Elena , Shackih Zoya
Published: July 2021

The digital transformation of energy infrastructure is a priority task for the development of energy in the Russian Federation, implemented in a project-based approach - in the initiation of the departmental project “Digital Energy” by the Ministry of Energy of the Russian Federation. The project can get an additional impetus for development in the current conditions of the “crisis of 2020”, which are positioned as a trigger for digital transformations in the sectors of the economy. To what extent are the activities of the Digital Energy project aimed at digital transformation of the energy industry and do consumers see changes when they receive services? Should we expect an intensification of the digital transformation of the energy sector in the context of the 2020 crisis? The questions are acute and relevant, which determine the purpose of the study - to assess the digital transformation of the energy sector in the Russian Federation implemented in the project approach in the context of the “crisis of 2020”, revealing the expert opinion of the stakeholders. Research methods: end-to-end analysis of project activities in a comparative assessment with foreign factography; secondary analysis of interviews with top managers of energy enterprises on the issue of digitalization and digital transformation of energy; survey of individuals-consumers of electricity (N = 60). The conducted research provides a basis for the conclusion about the implementation of the digitalization process in the energy sector and does not allow identifying the conditions of the “crisis of 2020” as a trigger for the transition of digitalization to the digital transformation of the energy industry. Identified consumers-detractors, whose positions are working to identify “points of growth” of digital transformation of the electric power industry in the future.
Determination of the characteristic points of approximation for traction electric machines of electric rolling stock
Authors: Filina Olga , Yashagina Anna , Salnikova Olga
Published: July 2021

The paper presents a new approach to the selection of characteristic points on the current-voltage curve (CVC) of the brush contact of traction electric machines, for their approximation in the form of three different functions, with characteristic points of transition to the field weakening mode. The problem of raising resources by using new design electro brushes. This constructive solution is consistent with the specific types of traction motors used in urban and rail transport and satisfies the technical conditions for their operation. A construction brush holders, which will save the cost of electro, in connection with their wear and tear due to friction on the walls of the brush holders. Improving the quality of machines saves material means and human resources, increase the profitability of their use, resulting in a significant increase in productivity. The method of calculating the current-voltage characteristics of a new type electro brushes, the distinguishing feature of which is the introduction of a cross section of the body brush. In the course of the experiment revealed steadily increasing rate of proposed electro brushes, compared with the standard of the same type EG61A. Data collected during the experiment showed that electro brushes with a transverse incision is more stable contact with the collector.
Problems of Power Factor Correction in Power Supply Systems with Higher Harmonics Sources
Authors: Govorun Vladimir , Govorun Oleg , Markovskiy Vadim , Zhumadirova Aliya
Published: July 2021

In this paper, on the basis of simulation modeling, an algorithm for studying the current resonance that occurs in the power supply system with a chaotic change of the load power and variation of reactive power compensation degree, in the presence of consumers with a nonlinear current-voltage characteristic is proposed. It is shown that overloading of capacitor banks can occur in a wide frequency range, close to the resonant frequency. The proposed algorithm determines all possible frequencies at which an increase of currents in capacitor banks can occur above the permissible values in parallel resonance. The purpose of the proposed work: to show in what operating modes of the enterprise power supply system an overload of capacitors by currents of higher harmonics can occur when the load power changes and the degree of reactive power compensation varies.
Distributed automated control and protection system for power lines with any degree of longitudinal compensation
Authors: Novokreshenov Vitaly Viktorovich , Ivanova Viliya Ravilevna , Rozhencova Nataliya Vladimirovna
Published: July 2021

With longitudinal compensation of the reactance of the line, the problem of its protection against overcurrents arises from the point of view of relay protection. The problem is relevant with a greater degree of compensation. When compensating more than 50% of the reactance of the line, the protection of the power transmission line becomes practically impossible due to the failure or false operation of all existing types and forms of protection [1, 2]. Therefore, at present, the compensation of the line reactance is, as a rule, no more than 50% [3, 4], which does not allow the full potential of the line in terms of its transmission capacity to be revealed. The purpose of this study was to develop and test a new relay protection algorithm to be able to solve the above problem. The studies were carried out using modeling techniques in the PS CAD package, where a power transmission line with longitudinal compensation and an algorithm to protect it from internal damage were built. When carrying out the research, the work was carried out on the protection algorithm of the power transmission line with longitudinal compensation in the static mode without transferring electricity between substations and without the transmission mode along the active power line in both directions. It is shown that in order to determine the location of the damage, it is possible to use the criterion of the angle of the active component of the short-circuit current, which depends exclusively on the voltage angle and does not depend on the reactive parameters of the electrical network. The simulation result showed correct operation in all investigated modes. The algorithm described in the article showed quite satisfactory results, which makes it possible to protect the power transmission line with any degree of longitudinal compensation.
Impact of globalization on the development of commerce
Authors: Salikhova Regina , Dyganova Renata , Khusainova Ekaterina , Derbeneva Anna
Published: July 2021

Globalization, the transition to an information society - modern processes of social development, due to a number of factors: the structure of social reproduction of countries, the level of economic development of countries, the availability of natural resources, the peculiarities of the internal market, etc. Globalization and the increasingly active use of digital technologies are affecting changes in the country's internal trade, increasing the share of electronic commerce in its composition. Electronic commerce predetermines the development of channels of distribution of goods and services different from traditional channels, and the applied business processes make it possible to discover and apply existing reserves and previously unused potential opportunities in economic activity in order to increase not only the income received, but also provide goods to remote (and small) populations. points.
Investigation of the shapes of cuts in a plate in contact with a rigid stamp
Authors: Abdigaliyeva Akmaral , Bigaliyeva Venera , Zholdassova Sharaina , Shabdirov Daryn , Shagayeva Ainur
Published: July 2021

A mathematical model of a contact interaction between a plate and rigid stamp is derived taking into account physical and design details. The plate is considered to have a crack, that changes its form. The problem of the contact is evaluated based on the theory of variational inequalities. The shape of the stamp is assumed to be perpendicular to the plate surface and the Poisson’s ratio is between 0 and 0.5. Analytical formulation of the study consists of transformation equation, boundary conditions and integral equation. The result is used in maximization and minimization problems for choosing extremal shape of the vertical break in the plate.
A PMU-based algorithm of synchronous generator stability prediction during a disturbance
Authors: Senyuk Mihail , Moiseichenkov Alexander , Kovalenko Pavel , Mukhin Valentin
Published: July 2021

A PMU-based algorithm of synchronous generator stability prediction is proposed and tested in the paper. The algorithm is based on the application of the equal area criterion for the following spaces: active power – load angle, active power – time. The deceleration area is formed using the least squares curve fitting by the second order polynomial. The algorithm was tested on the single synchronous machine power system. A number of transients was simulated with the power angle curve polynomial accuracy of 50 ms. The results have shown high adaptability and efficiency of the proposed algorithm. It can be used in adaptive protection and control devices to form control actions aimed at ensuring the stability of a power system operation.
Features of calculations for arc quenching reactors with non-magnetic gaps in core of magnetic circuit
Authors: Bayazitov Ildar , Galimzyanov Rustem , Medvedev Vjacheslav , Petrov Mikhail
Published: July 2021

This article presents the results of comparative studies of existing methods to calculate the inductance of dynamic and static single-phase reactors of arc extinguishing by double-rod and armored magnetic circuits with non-magnetic gaps in terms of the geometric parameters of the device. There are proposed expressions to correct the determination of the effective area of the winding of reactors by the shunting magnetic flux. On the basis of numerical calculations, the significant influence of the correct calculation of the effective area of the reactor winding by the shunt magnetic flux on the result of calculating the inductance is shown, it undoubtedly affecting the accuracy of the operation of both many digital devices of existing substations in particular, and new digital substations being introduced in general. It was also found in the work, that carrying out the correct calculation will improve both electrical characteristics of the device, and technical economic indicators of capacitive current compensation systems as part of digital substations, when setting the inverse problem of determining the geometric dimensions of the electrical part of the reactor according to the known inductance value, which depends and is calculated on the parameters of the given network, including capacitive currents.
Energy of adsorption of polar molecules on NaLSX zeolite
Authors: Jumaeva Dilnoza , Toirov Olimjon , Rakhmatullaeva Ravshan Akhmedov Nigora , Eshmetov Izzat
Published: July 2021

The article presents precision data of isotherms and total thermodynamic characteristics, i.e. ΔH, ΔF and ΔS of H2O adsorption on NaLSX zeolite. The stepwise nature of the change in the heat of adsorption on the studied systems with surface filling is revealed, and the molecular mechanism of water adsorption on NaLSX zeolite in the entire filling area is revealed. It was found that the polar water molecule is adsorbed in the NaLSX zeolite in an amount of 31.8 H2O/1/8 e.u., of which 25.3 are in super cavities, and 6.5 are in β-cavities.