bluuebunny/crossref_metadata_2025_split huggingface dataset:
PEMECAHAN MASALAH KOMPETISI MATEMATIKA BAGI GURU SEKOLAH DASAR TAHAP I
Authors: Yohanes Rudi Santoso , Sari Ana Easti Rahayu Maya 
Published: August 2021

The rapid development of science and technology ushers people into the era of global competition in various fields of science, one of which is mathematics. The national mathematics competition at sd/mi level that has been pioneered in 2003 is one of the strategic containers to realize the educational paradigm. But even so, not all teachers are able to follow the wishes of science and technology. The current condition also requires teachers to be able to follow the development of science and technology in training and accompanying students in self-learning from their own homes. Before this condition teachers have also been subjected to demands to be able to train students to compete in academic fields such as mathematics. However, not all teachers are able to provide proper training to students as a form of preparation for them when they want to enter the competition. Math Competition Problem Solving Training activity is one form of activity that is expected to be a solution to the condition The training activity which was attended by 15 people consisting of 9 teachers, 1 lecturer, 1 civil servant, 1 housewife and 3 students received a positive response through questions and problem solving that had been given during the training, so it will be a consideration for the plan of implementation of similar activities next.

Abstrak: Pesatnya perkembangan ilmu pengetahuan dan teknologi mengantarkan manusia ke era kompetisi global di berbagai bidang ilmu salah satunya adalah matematika. Kompetisi matematika nasional tingkat SD/MI yang telah dirintis tahun 2003 merupakan salah satu wadah yang strategis untuk merealisasi paradigma pendidikan. Namun meskipun demikian belum semua guru mampu untuk mengikuti perkembangan ilmu pengetahuan dan teknologi yang ada. Kondisi sekarang ini pun menuntut guru untuk bisa mengikuti perkembangan ilmu pengetahuan dan teknologi dalam melatih dan mendampingi siswa dalam belajar mandiri dari rumah mereka masing-masing. Sebelum kondisi ini guru pun juga sudah mendapatkan tuntutan untuk dapat melatih siswa agar dapat berkompetisi dibidang akademik seperti matematika. Meskipun demikian belum semua guru mampu untuk memberikan latihan yang tepat kepada siswa sebagai bentuk persiapan bagi mereka ketika hendak mengikuti kompetisi. Kegiatan Pelatihan Pemecahan Masalah Kompetisi Matematika merupakan salah satu bentuk kegiatan yang diharapkan mampu menjadi solusi terhadap kondisi tersebut. Kegiatan Pelatihan yang diikuti oleh 15 orang ini yang terdiri atas 9 orang guru, 1 dosen, 1 pegawai negeri sipil, 1 ibu rumah tangga dan 3 mahasiswa ini mendapatkan respon yang positif melalui pertanyaan dan penyelesaian soal yang telah diberikan selama pelatihan sehingga akan menjadi pertimbangan untuk rencana pelaksanaan kegiatan serupa berikutnya.
Controlled Element Specific Nanoscale Domains by Self‐Assembly for High Performance Bifunctional Alkaline Water Splitting Catalyst
Authors: Fan Hua , Maheshwari Vivek 
Published: August 2021

AbstractA stable bifunctional water‐splitting catalyst can simplify the development of alkaline medium electrolyzers. In this study, a catalytic material with controlled nanoscale domains of Pt and Ni is formed by a self‐assembly process at room temperature. The final structure of the catalyst is achieved through two‐stage transformation, first is the formation of Pt‐Ni nanoscale domains and then inducing Ni to higher oxidation states. The material has a nanowire‐like morphology at the macroscale, which ensures rapid kinetics and mass transfer. The results prove that the nanoscale domains of Pt, Ni, and Ni2+ and Ni3+ with close interfacing are crucial for the performance of the electrocatalyst and ensure the presence of Ni in a high oxidation state, leading to both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activity. The catalyst has a low overpotential and ultralow Tafel slope for both HER and OER, 13.7 and 32 mV dec−1, respectively, crucial for high power applications.
The roles of dispersal limitation, climatic niches and glacial history in endemism of the North American bryophyte flora
Authors: Carter Benjamin E. 
Published: August 2021

AbstractPremiseBryophytes (mosses, liverworts, and hornworts) tend to have very large geographic ranges, which impedes progress toward understanding the drivers of diversification and extinction. This study aimed to investigate whether North American endemics differ geographically from more widespread species and whether differences in climatic niche or traits related to dispersal and establishment differ between endemics and more widespread species.MethodsAll available herbarium records of bryophytes from North America north of Mexico (106 collections) were used. Traits related to dispersal were obtained from the literature. Analyses tested whether range sizes and extents differed between endemics and nonendemics, and whether trait differences were associated with endemism. Climate data were used to determine whether differences in niche breadth are present between endemics and nonendemics, and whether suitable climate for endemics occurs outside North America.ResultsNonendemics have range sizes twice as large as endemics and they occur farther north and have greater longitudinal extents. However, they do not have the widest niche breadths and do not differ in spore size (with few exceptions) or sexual condition. Asexual propagules are more prevalent among nonendemics. Climatic models indicate that substantial areas of climate suitable for endemics exist outside of North America.ConclusionsDistributions of endemics and nonendemics are consistent with an important role of glaciation in shaping the North American bryophyte flora. Endemics are not limited to the continent based on a lack of suitable climate elsewhere or by spore size or sexual condition.
A survey of current practice in reporting third trimester fetal biometry and Doppler in Australia and New Zealand
Authors: Paoletti Debra , Smyth Lillian , Westerway Susan , Hyett Jon , Mogra Ritu , Haslett Stephen , Peek Michael 
Published: August 2021

AbstractIntroductionInconsistent reporting practices in third trimester ultrasound, the choice of reference charts in particular, have the potential to misdiagnose abnormal fetal growth. But this may lead to unnecessary anxiety and confusion amongst patients and clinicians and ultimately influence clinical management. Therefore, we sought to determine the extent of variability in choice of fetal biometry and Doppler reference charts and reporting practices in Australia and New Zealand.MethodsClinicians performing and/or reporting obstetric ultrasound were invited to answer questions about fetal biometry and Doppler charts in a web‐based survey.ResultsAt least four population‐based charts are in current use. The majority of respondents (78%) report the percentile for known gestational age (GA) alongside measurements and 63% using a cut‐off of estimated fetal weight (EFW) < 10th percentile when reporting small for gestational age (SGA) and/or fetal growth restriction (FGR). The thresholds for the use of fetal and maternal Doppler in third trimester ultrasound varied in terms of the GA, EFW cut‐off, and how measures were reported. The majority of respondents were not sure of which Doppler charts were used in their practice.ConclusionThis survey revealed inconsistencies in choice of reference chart and reporting practices. The potential for misdiagnosis of abnormal fetal growth remains a significant issue.
Conversion of Ammonia to Hydrazine Induced by High‐Frequency Ultrasound
Authors: Humblot Anaelle , Grimaud Laurie , Allavena Audrey , Amaniampong Prince N. , De Oliveira Vigier Karine , Chave Tony , Streiff Stéphane , Jérôme François 
Published: August 2021

AbstractHydrazine is a chemical of utmost importance in our society, either for organic synthesis or energy use. The direct conversion of NH3 to hydrazine is highly appealing, but it remains a very difficult task because the degradation of hydrazine is thermodynamically more feasible than the cleavage of the N−H bond of NH3. As a result, any catalyst capable of activating NH3 will thus unavoidably decompose N2H4. Here we show that cavitation bubbles, created by ultrasonic irradiation of aqueous NH3 at a high frequency, act as microreactors to activate and convert NH3 to NH species, without assistance of any catalyst, yielding hydrazine at the bubble–liquid interface. The compartmentation of in‐situ‐produced hydrazine in the bulk solution, which is maintained close to 30 °C, advantageously prevents its thermal degradation, a recurrent problem faced by previous technologies. This work also points towards a path to scavenge .OH radicals by adjusting the NH3 concentration.
Allosteric Switching of Calmodulin in a Mycobacterium smegmatis porin A (MspA) Nanopore‐Trap
Authors: Liu Yao , Pan Tiezheng , Wang Kefan , Wang Yuqin , Yan Shuanghong , Wang Liying , Zhang Shanyu , Du Xiaoyu , Jia Wendong , Zhang Panke , Chen Hong‐Yuan , Huang Shuo 
Published: August 2021

AbstractRecent developments concerning large protein nanopores suggest a new approach to structure profiling of native folded proteins. In this work, the large vestibule of Mycobacterium smegmatis porin A (MspA) and calmodulin (CaM), a Ca2+‐binding protein, were used in the direct observation of the protein structure. Three conformers, including the Ca2+‐free, Ca2+‐bound, and target peptide‐bound states of CaM, were unambiguously distinguished. A disease related mutant, CaM D129G was also discriminated by MspA, revealing how a single amino acid replacement can interfere with the Ca2+‐binding capacity of the whole protein. The binding capacity and aggregation effect of CaM induced by different ions (Mg2+/Sr2+/Ba2+/Ca2+/Pb2+/Tb3+) were also investigated and the stability of MspA in extreme conditions was evaluated. This work demonstrates the most systematic single‐molecule investigation of different allosteric conformers of CaM, acknowledging the high sensing resolution offered by the MspA nanopore trap.
Switchable, Reagent‐Controlled Diastereodivergent Photocatalytic Carbocyclisation of Imine‐Derived α‐Amino Radicals
Authors: Maitland J. Andrew P. , Leitch Jamie A. , Yamazaki Ken , Christensen Kirsten E. , Cassar Doyle J. , Hamlin Trevor A. , Dixon Darren J. 
Published: August 2021

AbstractA reagent‐controlled stereodivergent carbocyclisation of aryl aldimine‐derived, photocatalytically generated, α‐amino radicals possessing adjacent conjugated alkenes, affording either bicyclic or tetracyclic products, is described. Under net reductive conditions using commercial Hantzsch ester, the α‐amino radical species underwent a single stereoselective cyclisation to give trans‐configured amino‐indane structures in good yield, whereas using a substituted Hantzsch ester as a milder reductant afforded cis‐fused tetracyclic tetrahydroquinoline frameworks, resulting from two consecutive radical cyclisations. Judicious choice of the reaction conditions allowed libraries of both single and dual cyclisation products to be synthesised with high selectivity, notable predictability, and good‐to‐excellent yields. Computational analysis employing DFT revealed the reaction pathway and mechanistic rationale behind this finely balanced yet readily controlled photocatalytic system.
Sulfur‐Dopant‐Promoted Electroreduction of CO2 over Coordinatively Unsaturated Ni‐N2 Moieties
Authors: Jia Chen , Tan Xin , Zhao Yong , Ren Wenhao , Li Yibing , Su Zhen , Smith Sean C. , Zhao Chuan 
Published: August 2021

AbstractAtomically dispersed nickel–nitrogen–carbon (Ni‐N‐C) moieties are promising for efficient electrochemical CO2‐to‐CO conversion. To improve the intrinsic electrocatalytic activity, it is essential but challenging to steer the coordination environment of Ni centers for promoting the CO formation kinetics. Here, we introduce alien sulfur atoms to tune the local electronic density of unsaturated NiN2 species. A coordinated structure evolution is detected and S vacancies are generated at high overpotentials, as confirmed by X‐ray absorption spectroscopy. The sulfur dopants enhance CO selectivity and activity over normal unsaturated NiN2 structure, reaching a high CO Faradaic efficiency of 97 % and a large CO current density of 40.3 mA cm−2 in a H‐cell at −0.8 V and −0.9 V (vs. RHE), respectively. DFT calculations reveal both doped S atoms and evolved S vacancies in the NiN2 coordination environment contribute to the reduced energy barriers for CO2 electroreduction to CO.
Facile Synthesis of Chiral Arylamines, Alkylamines and Amides by Enantioselective NiH‐Catalyzed Hydroamination
Authors: Meng Lingpu , Yang Jingjie , Duan Mei , Wang You , Zhu Shaolin 
Published: August 2021

AbstractRegio‐ and enantioselective hydroarylamination, hydroalkylamination and hydroamidation of styrenes have been developed by NiH catalysis with a simple bioxazoline ligand under mild conditions. A wide range of enantioenriched benzylic arylamines, alkylamines and amides can be easily accessed by nitroarenes, hydroxylamines and dioxazolones, respectively as amination reagents. The chiral induction in these reactions is proposed to proceed through an enantiodifferentiating syn‐hydronickellation step.
Determining home range, changes in habitat use with time, and the threats to an endangered freshwater turtle (Rafetus euphraticus) in Turkey
Authors: Bayrakcı Yusuf , Ayaz Dinçer , Luiselli Luca 
Published: August 2021

Abstract

The Euphrates softshell turtle (Rafetus euphraticus) is the most threatened chelonian species in the Middle East, where it is endemic to the Tigris and Euphrates basins. Since the ecology of this species is little known, it is difficult to plan any reliable action for its correct management and conservation.
To enhance the scientific knowledge on R. euphraticus, and to establish a science‐based management strategy, a detailed investigation was undertaken on the distribution, habitat, activity and home range of R. euphraticus in Turkey. The previous distribution records in Turkey are for the 1990s; thus, this study is the first comprehensive field research on the species after nearly 3 decades.
There was a significant sexual size dimorphism in the Turkish population, with males larger than females.
Four individuals were radiotracked for 1 year. The mean home range was highly variable depending on how it was calculated, but that of males was considerably greater than that of females by all methods used.
A quantitative evaluation was made of habitat change with time. The land cover classes potentially available to turtles in the Euphrates River basin increased by more than 100% between the 1990s and 2018: 92% of this enhancement was derived from water bodies and coastal lands.
Fifteen dams have been built in the lower part of the basins in the last 30 years. In addition, continuing human interactions have caused the fragmentation or destruction of suitable habitats for R. euphraticus.
The factors threatening R. euphraticus were assessed and a conservation action plan was developed. Some objectives such as monitoring and creating awareness of this action plan have been met while others are still waiting to be achieved.
Covariant canonical gauge theory of gravitation for fermions
Authors: Struckmeier Jürgen , Vasak David 
Published: August 2021

AbstractWe derive the interaction of fermions with a dynamical space–time based on the postulate that the description of physics should be independent of the reference frame, which means to require the form‐invariance of the fermion action under diffeomorphisms. The derivation is worked out in the Hamiltonian formalism as a canonical transformation along the line of non‐Abelian gauge theories. This yields a closed set of field equations for fermions, unambiguously fixing their coupling to dynamical space–time. We encounter, in addition to the well‐known minimal coupling, anomalous couplings to curvature and torsion. In torsion‐free geometries that anomalous interaction reduces to a Pauli‐type coupling with the curvature scalar via a spontaneously emerged new coupling constant with the dimension of mass. A consistent model Hamiltonian for the free gravitational field and the impact of its functional form on the structure of the dynamical geometry space–time is discussed.
Outcomes of poorly differentiated and plasmacytoid variant bladder urothelial carcinoma
Authors: Lockhart Kathleen , King Simon , Grant Alexander , McLeod Nicholas , Tiu Albert 
Published: August 2021

AbstractObjectivesThe aim of this study is to assess the course and management of poorly differentiated bladder urothelial carcinoma (UC), including plasmacytoid UC (PUC), in our local area. Although bladder cancer is relatively common, PUC is a rare and aggressive subtype with a poor prognosis that is still poorly understood.Materials and MethodsA retrospective assessment of all poorly differentiated high‐grade UC over the last 15 years (2005–2020) in the Hunter New England area was completed. In total, 37 patients were included, and PUC variant was compared with the remaining poorly differentiated UC.ResultsOf the included cases, eight were PUC, nine squamous variant, two neuroendocrine, and one sarcomatoid. Overall, 23 cases proceeded to cystectomy, 15 had chemotherapy (six neoadjuvant), and 11 had radiation therapy. In the PUC subgroup, three had metastatic disease at diagnosis (37.5%). Of the three PUC patients who underwent cystectomy, all were upstaged. Two PUC cases had adjuvant chemotherapy, and one case had radiation. Within the follow‐up period, the PUC group had a cause‐specific mortality of 50% with a mean survival in these patients of 202 days, compared with 37.9% cause‐specific mortality with survival of 671.55 days (p = 0.23) in all other undifferentiated UC cases; 5‐year cause‐specific mortality with Kaplan–Meier analysis was estimated at 26% compared with 59%, respectively (p = 0.058).ConclusionPoorly differentiated UC is demonstrated to have a poor prognosis with a high mortality rate, particularly when PUC is present. Given the rarity of these variants, further studies are necessary to explore the impact of current treatment options.
‘I then had 50 stitches in my arms…such damage to my own body’: An Interpretative Phenomenological Analysis of Izzat trauma and self‐harm experiences among UK women of South Asian heritage
Authors: Mafura Calvin , Charura Divine 
Published: August 2021

AbstractBackground and aimsSelf‐mutilation (self‐harm) is a phenomenon that is increasingly being seen in patients presenting in mental health services in the United Kingdom. This present study aimed to explore the lived experience of South Asian women raised in the United Kingdom and their perspective of ‘Izzat’, which refers to honour.MethodSemi‐structured interviews were conducted with 12 women of ‘South Asian' heritage. Their accounts were analysed using interpretative phenomenological analysis (IPA).Findings and discussionThe findings suggest that the concept of Izzat and Asian cultural identity permeated the narratives of all the participants. The results position Izzat as central to cultural discord felt by the women and as a base for some of the discontent that led to self‐mutilating. The analysis revealed five over‐arching themes as the most common factors to self‐harm among South Asian women, which include: (1) The struggle to maintain cultural identity, (2) Experience of loss of control and trauma, (3) Focus on self‐mutilation as a distraction process, (4) Psychological angst as metacommunication of pain, and (5) Enactment of perceived deserved punishment. Our conclusions argue for the importance of understanding the complexity of cultural diversity, introjected cultural expectations, and its impact on the development of trauma and implications for clinical practice.Future research and practice should focus on exploring trauma‐informed methodologies and culturally sensitive approaches in working with those impacted by Izzat and the cultural responsibility of maintaining family honour.
Persistent gestational trophoblastic disease following ovarian molar pregnancy: A case report of a rare entity with review of the literature
Authors: Thapa Bibechan , Maharjan Meenu , Tuladhar Heera 
Published: August 2021

AbstractOvarian molar pregnancy, though a very rare entity, behaves like any other molar pregnancy. After surgical management, close follow‐up with β‐hCG surveillance is invariable to detect progression to persistent gestational trophoblastic disease.
Retroperitoneal Fibrosis as a presentation with masked multiorgan involvement of IgG4‐related disease—demystifying the diagnosis: A case report from Nepal
Authors: Shah Sangam , Chamlagain Rajan , Baral Bikash , Shrestha Sanjib , Adhikari Yagya Raj , Jha Saket 
Published: August 2021

AbstractThe timely diagnosis of the disease helps in preventing the progression of RF and unnecessary interventions that may mislead the diagnosis. Biopsy and serum IgG4 both can be non‐specific.
Single‐Atom Catalysts‐Enabled Reductive Upgrading of CO2
Authors: Tan Xiang , Li Hu , Yang Song 
Published: August 2021

AbstractSingle‐atom catalysts (SACs) have attracted extensive attention since their emergence. During the single‐atomic catalytic process, the “active center” exists in the form of atomical monodispersion, with nearly 100 % utilization of metal atoms. Uniform and atomically dispersed catalytic centers give SACs pronounced reaction activity and chemical selectivity. Here, we review the development processes, synthetic strategies, characterization methods, and applications of SACs in CO2 reductive upgrading. Also, a comparison of SACs with conventional heterogeneous catalysts in catalytic CO2 reduction is made and discussed. SACs have built a bridge between homogeneous and heterogeneous catalysis and have the advantages of both, showing a broad prospect in the field of catalysis.
Developing N‐Rich Carbon from C3N4‐Polydopamine Composites for Efficient Oxygen Reduction Reaction
Authors: Ferraz Beatriz J. , Li Bing , Guo Zhengxiao , Blackman Christopher , Liu Zhaolin 
Published: August 2021

AbstractNitrogen‐rich carbon‐based materials are amongst the most promising electrocatalysts for the oxygen reduction reaction (ORR) and/or the oxygen evolution reaction (OER). The introduction of nitrogen within the carbonaceous framework generates catalytic active sites and alters the electrical conductivity. However, the synthesis of these materials often involves long processes and severe reaction conditions which yield a low concentration of nitrogen (N) functionalities. Herein, we present a facile method for the synthesis of N‐rich carbon by carbonizing a carbon nitride (C3N4)‐polydopamine composite (CNDA) which can readily be prepared by room temperature self‐polymerisation of dopamine in the presence of C3N4. The intrinsically high N content in C3N4 leads to a highly N‐doped carbon. The CNDA catalyst synthesized at 900 °C contained 12.5 at% of N, enhancing both the ORR and OER catalytic activities through a 4‐e− dominated pathway, providing a comparable E1/2 and a remarkably improved diffusion‐limited current to the other reported N‐doped carbon catalysts. When used as an air‐cathode in a zinc‐air battery, this CNDA catalyst possessed stable discharge‐charge cycling performance for 216 h, outperforming the Pt/C standard. This work opens a promising platform for the development of template‐free processes for the synthesis of non‐metal and nitrogen‐rich carbon materials which are attractive for metal‐air batteries and fuel cells.