bluuebunny/crossref_metadata_2025 huggingface dataset:
Directed evolution of Metarhizium fungus improves its biocontrol efficacy against Varroa mites in honey bee colonies
Authors: Han Jennifer O. , Naeger Nicholas L. , Hopkins Brandon K. , Sumerlin David , Stamets Paul E. , Carris Lori M. , Sheppard Walter S.
Published: May 2021

Entomopathogenic fungi show great promise as pesticides in terms of their relatively high target specificity, low non-target toxicity, and low residual effects in agricultural fields and the environment. However, they also frequently have characteristics that limit their use, especially concerning tolerances to temperature, ultraviolet radiation, or other abiotic factors. The devastating ectoparasite of honey bees, Varroa destructor, is susceptible to entomopathogenic fungi, but the relatively warm temperatures inside honey bee hives have prevented these fungi from becoming effective control measures. Using a combination of traditional selection and directed evolution techniques developed for this system, new strains of Metarhizium brunneum were created that survived, germinated, and grew better at bee hive temperatures (35 °C). Field tests with full-sized honey bee colonies confirmed that the new strain JH1078 is more virulent against Varroa mites and controls the pest comparable to current treatments. These results indicate that entomopathogenic fungi are evolutionarily labile and capable of playing a larger role in modern pest management practices.
Optimization of sunflower head pectin extraction by ammonium oxalate and the effect of drying conditions on properties
Authors: Ma Xuemei , Yu Jiayi , Jing Jing , Zhao Qian , Ren Liyong , Hu Zhiyong
Published: May 2021

Pectin is a kind of natural and complex carbohydrates which is extensively used in food, chemical, cosmetic, and pharmaceutical industries. Fresh sunflower (Helianthus annuus L.) heads were utilized as a novel source of pectin extracted by ammonium oxalate. The conditions of the extraction process were optimized implementing the response surface methodology. Under optimal extraction parameters (extraction time 1.34 h, liquid–solid ratio 15:1 mL/g, ammonium oxalate concentration 0.76% (w/v)), the maximum experimental yield was 7.36%. The effect of spray-drying and freeze-drying on the physiochemical properties, structural characteristics, and antioxidant activities was investigated by FT-IR spectroscopy, high performance size exclusion chromatography, and X-ray diffraction. The results showed freeze-drying lead to decrease in galacturonic acid (GalA) content (76.2%), molecular weight (Mw 316 kDa), and crystallinity. The antioxidant activities of pectin were investigated utilizing the in-vitro DPPH and ABTS radical-scavenging systems. This study provided a novel and efficient extraction method of sunflower pectin, and confirmed that different drying processes had an effect on the structure and properties of pectin.
Impact of natural salt lick on the home range of Panthera tigris at the Royal Belum Rainforest, Malaysia
Authors: Lazarus Bryan Andrew , Che-Amat Azlan , Abdul Halim Shah Muhammad Muzammil , Hamdan Azwan , Abu Hassim Hasliza , Mustaffa Kamal Farina , Tengku Azizan Tengku Rinalfi Putra , Mohd Noor Mohd Hezmee , Mohamed Mustapha Noordin , Ahmad Hafandi
Published: May 2021

Natural salt lick (sira) is a strategic localisation for ecological wildlife assemblage to exhibit geophagy which may act as a population dynamic buffer of prey and predators. Undoubtedly, many agree that geophagy at natural licks is linked to nutritional ecology, health and assembly places facilitating social interaction of its users. Overall, natural salt licks not only save energy of obtaining nutrient leading to health maintenance but also forms the basis of population persistence. The Royal Belum Rainforest, Malaysia (Royal Belum) is a typical tropical rainforest in Malaysia rich in wildlife which are mainly concentrated around the natural salt lick. Since this is one of the most stable fauna ecology forest in Malaysia, it is timely to assess its impact on the Malayan tiger (Panthera tigris) home range dynamics. The three-potential home ranges of the Malayan tiger in this rainforest were selected based on animal trails or foot prints surrounding the salt lick viz (e.g. Sira Kuak and Sira Batu; Sira Rambai and Sira Buluh and Sira Papan) as well as previous sightings of a Malayan tiger in the area, whose movement is dependent on the density and distribution of prey. Camera traps were placed at potential animal trails surrounding the salt lick to capture any encountered wildlife species within the area of the camera placements. Results showed that all home ranges of Malayan tiger were of no significance for large bodied prey availability such as sambar deer (Rusa unicolor), and smaller prey such as muntjacs (Muntiacus muntjac) and wild boar (Sus scrofa). Interestingly, all home range harbour the Malayan tiger as the only sole predator. The non-significance of prey availability at each home range is attributed to the decline of the Malayan tiger in the rainforest since tigers are dependant on the movement of its preferred prey surrounding natural salt licks. Thus, the information from this study offers fundamental knowledge on the importance of prey-predator interaction at salt lick which will help in designing strategy in rewilding or rehabilitation programs of the Malayan tiger at the Royal Belum Rainforest.
Publisher Correction: The effect of taxonomic classification by full-length 16S rRNA sequencing with a synthetic long-read technology
Authors: Jeong Jinuk , Yun Kyeongeui , Mun Seyoung , Chung Won‑Hyong , Choi Song‑Yi , Nam Young‑do , Lim Mi Young , Hong Chang Pyo , Park ChanHyeok , Ahn Yong Ju , Han Kyudong
Published: May 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
A bispecific antibody agonist of the IL-2 heterodimeric receptor preferentially promotes in vivo expansion of CD8 and NK cells
Authors: Harris Katherine E. , Lorentsen Kyle J. , Malik-Chaudhry Harbani K. , Loughlin Kaitlyn , Basappa Harish Medlari , Hartstein Sharon , Ahmil Ghenima , Allen Nicole S. , Avanzino Brian C. , Balasubramani Aarti , Boudreau Andrew A. , Chang Karen , Cuturi Maria-Cristina , Davison Laura M. , Ho Dennis M. , Iyer Suhasini , Rangaswamy Udaya S. , Sankaran Preethi , Schellenberger Ute , Buelow Roland , Trinklein Nathan D.
Published: May 2021

The use of recombinant interleukin-2 (IL-2) as a therapeutic protein has been limited by significant toxicities despite its demonstrated ability to induce durable tumor-regression in cancer patients. The adverse events and limited efficacy of IL-2 treatment are due to the preferential binding of IL-2 to cells that express the high-affinity, trimeric receptor, IL-2Rαβγ such as endothelial cells and T-regulatory cells, respectively. Here, we describe a novel bispecific heavy-chain only antibody which binds to and activates signaling through the heterodimeric IL-2Rβγ receptor complex that is expressed on resting T-cells and NK cells. By avoiding binding to IL-2Rα, this molecule circumvents the preferential T-reg activation of native IL-2, while maintaining the robust stimulatory effects on T-cells and NK-cells in vitro. In vivo studies in both mice and cynomolgus monkeys confirm the molecule’s in vivo biological activity, extended pharmacodynamics due to the Fc portion of the molecule, and enhanced safety profile. Together, these results demonstrate that the bispecific antibody is a safe and effective IL-2R agonist that harnesses the benefits of the IL-2 signaling pathway as a potential anti-cancer therapy.
Linking genome size variation to population phenotypic variation within the rotifer, Brachionus asplanchnoidis
Authors: Stelzer Claus-Peter , Pichler Maria , Hatheuer Anita
Published: May 2021

Eukaryotic organisms usually contain much more genomic DNA than expected from their biological complexity. In explaining this pattern, selection-based hypotheses suggest that genome size evolves through selection acting on correlated life history traits, implicitly assuming the existence of phenotypic effects of (extra) genomic DNA that are independent of its information content. Here, we present conclusive evidence of such phenotypic effects within a well-mixed natural population that shows heritable variation in genome size. We found that genome size is positively correlated with body size, egg size, and embryonic development time in a population of the monogonont rotifer Brachionus asplanchnoidis. The effect on embryonic development time was mediated partly by an indirect effect (via egg size), and a direct effect, the latter indicating an increased replication cost of the larger amounts of DNA during mitosis. Our results suggest that selection-based change of genome size can operate in this population, provided it is strong enough to overcome drift or mutational change of genome size.
Correction: Transgenic PDGF-BB/sericin hydrogel supports for cell proliferation and osteogenic differentiation
Authors: Wang Feng , Hou Kai , Chen Wenjing , Wang Yuancheng , Wang Riyuan , Tian Chi , Xu Sheng , Ji Yanting , Yang Qianqian , Zhao Ping , Yu Ling , Lu Zhisong , Zhang Huijie , Li Fushu , Wang Han , He Baicheng , Kaplan David L. , Xia Qingyou
Published: May 2021

Correction for ‘Transgenic PDGF-BB/sericin hydrogel supports for cell proliferation and osteogenic differentiation’ by Feng Wang et al., Biomater. Sci., 2020, 8, 657–672, DOI: 10.1039/C9BM01478K.
Nucleophilic transformations of azido-containing carbonyl compounds via protection of the azido group
Authors: Aimi Takahiro , Meguro Tomohiro , Kobayashi Akihiro , Hosoya Takamitsu , Yoshida Suguru
Published: May 2021

Nucleophilic transformations of azido-containing carbonyl compounds are disclosed. The phosphazide formation from azides enabled transformations of carbonyl groups with nucleophiles.
Cucurbit[8]uril facilitated Michael addition for regioselective cysteine modification
Authors: Li Gao , Hu Jun , Chen Huai , Chen Yong-Xiang , Li Yan-Mei
Published: May 2021

Utilizing the interactions between tryptophan, methyl viologen and cucurbit[8]uril, distance between the targeted peptides/protein and the reactive peptide could be shortened, facilitating the Michael addition reaction between cysteine and dehydroalanine.
Catalyst-controlled site-selective N–H and C3-arylation of carbazole via carbene transfer reactions
Authors: Bera Sourav Sekhar , Bahukhandi Srishti Ballabh , Empel Claire , Koenigs Rene M.
Published: May 2021

A site-selective direct arylation reaction of carbazole and other N-heterocycles with diazo-naphthalen-2(1H)-ones has been developed.
Mechanism exploration of the enhancement of thermal energy storage in molten salt nanofluid
Authors: Li Zhao , Cui Liu , Li Baorang , Du Xiaoze
Published: May 2021

MD simulation results demonstrate that the interfacial thermal resistance and the compressed layer only affect the appearance, and the real mechanism involves the constraint on the base salt ions from the nanoparticle.
Multifunctional Pt(iv) prodrug candidates featuring the carboplatin core and deferoxamine
Authors: Harringer Sophia , Hejl Michaela , Enyedy Éva A. , Jakupec Michael A. , Galanski Mathea S. , Keppler Bernhard K. , Dyson Paul J. , Varbanov Hristo P.
Published: May 2021

Five new multifunctional Pt(iv) prodrugs with a carboplatin core and one or two axial deferoxamine ligands were synthesized. The complexes express multiple effects, including cytotoxicity and high affinity towards ferric ions.
Immobilization of Rh(i) precursor in a porphyrin metal–organic framework – turning on the catalytic activity
Authors: Szczepkowska Anna M. , Janeta Mateusz , Siczek Miłosz , Tylus Włodzimierz , Trzeciak Anna M. , Bury Wojciech
Published: May 2021

Installation of rhodium centers in a stable porphyrin-based ZrMOF platform for catalytic hydrogenation of unsaturated hydrocarbons under mild conditions.
Functionalized triphenylphosphine oxide-based manganese(ii) complexes for luminescent printing
Authors: Huang Xiaomeng , Qin Yanyan , She Pengfei , Meng Haixing , Liu Shujuan , Zhao Qiang
Published: May 2021

Three novel neutral manganese(ii) complexes (TPhPONMe2)2MnBr2, (TPhPOOMe)2MnBr2, and (TPhPOCF3)2MnBr2 based on a functionalized Ph3PO ligand were designed and synthesized for luminescent printing with high-resolution.
Electrocatalytic water splitting with unprecedentedly low overpotentials by nickel sulfide nanowires stuffed into carbon nitride scabbards
Authors: Zahran Zaki N. , Mohamed Eman A. , Tsubonouchi Yuta , Ishizaki Manabu , Togashi Takanari , Kurihara Masato , Saito Kenji , Yui Tatsuto , Yagi Masayuki
Published: May 2021

The unprecedentedly low overpotential of 32 mV for oxygen evolution was attained by forming a unique motif of NiSx nanowires stuffed into C3N4 scabbards. With this system, electrocatalytic water splitting was demonstrated at the lowest overall overpotential of 72 mV.
A multi-task deep learning neural network for predicting flammability-related properties from molecular structures
Authors: Yang Ao , Su Yang , Wang Zihao , Jin Saimeng , Ren Jingzheng , Zhang Xiangping , Shen Weifeng , Clark James H.
Published: May 2021

It is significant that hazardous properties of chemicals including replacements for banned or restricted products are assessed at an early stage of product and process design.
CO2(aq) concentration–dependent CO2 fixation via carboxylation by decarboxylase
Authors: Fan Yan , Feng Jianqiang , Yang Miao , Tan Xin , Fan Hongjun , Guo Meijin , Wang Binju , Xue Song
Published: May 2021

CO2(aq) concentration is a crucial parameter for increasing CO2 fixation yield via carboxylation by decarboxylase.
Exploiting a silver–bismuth hybrid material as heterogeneous noble metal catalyst for decarboxylations and decarboxylative deuterations of carboxylic acids under batch and continuous flow conditions
Authors: Mészáros Rebeka , Márton András , Szabados Márton , Varga Gábor , Kónya Zoltán , Kukovecz Ákos , Fülöp Ferenc , Pálinkó István , Ötvös Sándor B.
Published: May 2021

A silver-containing hybrid material is reported as a heterogeneous noble metal catalyst for protodecarboxylations and decarboxylative deuterations of carboxylic acids.
Visible-light-mediated organoboron-catalysed metal-free dehydrogenation of N-heterocycles using molecular oxygen
Authors: Wei Lanfeng , Wei Yu , Zhang Jinli , Xu Liang
Published: May 2021

A visible-light-induced aerobic dehydrogenation reaction of N-heterocycles has been achieved via the catalysis of an organoboron compound, under metal-free conditions.
Irreversible inhibition of BoNT/A protease: proximity-driven reactivity contingent upon a bifunctional approach
Authors: Turner Lewis D. , Nielsen Alexander L. , Lin Lucy , Pellett Sabine , Sugane Takashi , Olson Margaret E. , Johnson Eric A. , Janda Kim D.
Published: May 2021

A proximity-driven covalent bond with intrinsically less reactive warheads has been made possible by using a metal-chelating anchor for directed targeted covalent modification of Cys165 within the BoNT/A protease.
A solution-assisted etching preparation of an MOF-derived NH4CoPO4·H2O/Ti3C2Tx MXene nanocomposite for high-performance hybrid supercapacitors
Authors: Wei Wenhui , Luo Shijian , Zhao Ying , Li Xiaoman , Liang Bin , Fang Junzhuo , Luo Min
Published: May 2021

A novel synthetic is explored by introducing the Co-MOF(ZIF-67) into the layer space of Ti3C2Tx and subsequent in situ etching to transform into NH4CoPO4·H2O/Ti3C2Tx nanocomposite and used for high-performance hybrid supercapcitor.
Catalyst-controlled divergent transformations of N-sulfonyl-1,2,3-triazoles into isoquinolin-3-ones and 2-aminoindanones
Authors: Lee Kyu Ree , Jung Da Jung , Ahn Subin , Kim Ji Won , Lee Sang-gi
Published: May 2021

The intramolecular reaction of triazoles with allylic alcohol can be bifurcated by the choice of catalysts. In a Pd(0) mono-catalytic system, isoquinolin-3-ones were synthesized, while 2-aminoindanones could be produced under tandem Rh(ii)/Pd(0) dual catalytic reaction.
Correction: β-Methyl-δ-valerolactone-containing thermoplastic poly(ester-amide)s: synthesis, mechanical properties, and degradation behavior
Authors: Guptill David M. , Chinta Bhavani Shankar , Kaicharla Trinadh , Xu Shu , Hoye Thomas R.
Published: May 2021

Correction for ‘β-Methyl-δ-valerolactone-containing thermoplastic poly(ester-amide)s: synthesis, mechanical properties, and degradation behavior’ by David M. Guptill et al., Polym. Chem., 2021, 12, 1310–1316, DOI: 10.1039/D1PY00040C.
Single- and mixed-metal–organic framework photocatalysts for carbon dioxide reduction
Authors: Dao Xiao-Yao , Sun Wei-Yin
Published: May 2021

This review focuses on the important roles of varied metal types over MOF-based photocatalysts. The basic principles, types of MOF photocatalysts and roles of the reaction system to achieve efficient MOFs for CO2 photoreduction are discussed.
Circularly polarized luminescence from oriented polymer films doped with a tetraphenylethylene-based conjugated oligomer
Authors: Zhang Wan , Ni Baining , Li Hongkun , Yang Yonggang , Li Yongfang , Tang Ben Zhong
Published: May 2021

Oriented polymer films fabricated by photopolymerization of cholesteric liquid crystalline mixtures doped with a tetraphenylethylene-based conjugated oligomer can emit strong yellow-orange CPL with absolute glum values up to 0.77 and ΦF up to 60.4%.
In situ grown MnO2/graphdiyne oxide hybrid 3D nanoflowers for high-performance aqueous zinc-ion batteries
Authors: Wang Fuhui , Jin Weiyue , Xiong Zecheng , Liu Huibiao
Published: May 2021

MnO2@GDYO hybrid 3D nanoflowers have been designed and fabricated via the in situ growth of MnO2 in graphdiyne oxide nanosheets in aqueous solution. This work brings new prospects for the design of GDYO hybrids for high-performance aqueous ZIBs.
Pd-catalyzed cross-electrophile Coupling/C–H alkylation reaction enabled by a mediator generated via C(sp3)–H activation
Authors: Wu Zhuo , Jiang Hang , Zhang Yanghui
Published: May 2021

A cascade Pd-catalyzed cross-electrophile coupling and C–H alkylation reaction of 2-iodo-alkoxylarenes with alkyl chlorides has been developed by using an ortho-methoxy or benzyloxy group as a mediator via C(sp3)–H activation.
Aguardentes vínicas envelhecidas portuguesas: caracterização da produção, da comercialização e do estado de desenvolvimento do sector
Authors: Perdigão Joana , Canas Sara
Published: May 2021

As aguardentes vínicas envelhecidas são percepcionadas como produtos destatuse elevada qualidade, com longa história e tradição em Portugal. Apesar de a nível mundial este sector ter registado um aumento no volume e valor das vendas nos últimos anos, a nível nacional não existe informação disponível. O objectivo principal deste trabalho consiste assim na caracterização do sector das aguardentes vínicas em Portugal. A metodologia seguida incluiu a recolha de dados oficiais, a realização de entrevistas exploratórias a entidades do sector e o inquérito a produtores. Os resultados obtidos revelaram que a tecnologia de produção de aguardentes vínicas envelhecidas segue, em Portugal, os procedimentos estabelecidos como boas práticas a nível internacional. No entanto, uma fracção importante dos produtores não realiza sub-processos relevantes, como a destilação, o que poderá constituir um constrangimento à diversidade, tipicidade e qualidade das aguardentes vínicas envelhecidas portuguesas. Entre 2014 e 2018, os dados disponíveis apontam para uma estagnação do sector, com volumes anuais de vendas próximos dos 850.000 litros e um peso muito reduzido das Denominações de Origem. Os produtores consideram que o sector apresenta fraco dinamismo e que os volumes comercializados são reduzidos, faltando inovação, interesse e investimento. O peso excessivo da burocracia associada às numerosas questões legais que regulam a actividade, a elevada carga fiscal, a reduzida dimensão e a falta de procura (condicionada pelo desconhecimento dos consumidores sobre estes produtos), são as questões apontadas como principais entraves ao crescimento do sector. Em conclusão propõem-se algumas medidas de incentivo ao seu desenvolvimento.
Multi-objective optimal allocation of water resources in Yangchangwan mining area based on ecological priority
Authors: Zhang Zhen , Zhang Panyue , Zhang Guangming
Published: May 2021

With the development of mining area economy and the adjustment of industrial structure from traditional heavy industry to hightech industry, the supply and demand structure of water resources has changed significantly, and the ecological damage in mining area make the ecological water consumption increase significantly. This paper summarizes the water supply of surface water, groundwater, mine drainage and reclaimed water, as well as all kinds of water demand. Based on the principle of ecological priority, a multi-objective optimal allocation model for the coordinated development of ecological environment, social economy and water resources in Yangchangwan mining area was constructed. The results show that the multi-objective optimal allocation model well coordinated the social and economic development goals and resource saving goals, and the optimization scheme ensured that the water demand satisfaction of each water sector reached 100%. On the one hand, it can provide technical support for the mining area to realize the green water and green mountains pattern as soon as possible, on the other hand, it can also provide reference for water resources management in other similar areas.
Spatial heterogeneity analysis of CO2 emissions in China’s thermal power industry: GWR model
Authors: Wen Lei , Liu Fang
Published: May 2021

The thermal power industry is a major contributor to China's CO2 emissions, and its absolute emissions are still increasing year by year. Hence, this paper introduced a geographically weighted regression model to explore the spatial heterogeneity of different driving factors for this industry's CO2 emissions. The empirical results show that standard coal consumption is a decisive factor affecting thermal power industry's CO2 emissions, and its response to the western region is at the forefront. The average utilization hours of thermal power equipment in the central region exert a profound impact, while the western region devotes a lot to the installed capacity, and these two variables have great potential for CO2 emission mitigation. However, the urbanization level and per capita electricity consumption have a slight effect on CO2 emissions. These findings furnish constructive reference and policy implications to achieve emission abatement targets of different regions.
Determination and contents analysis of negative ions in vegetable simultaneous by ion chromatography
Authors: Zhang Yubai , Tang Xuexi
Published: May 2021

A method of high-speed to determine some negative ions and their contents in vegetable by ion chromatography is proposed in this paper, which was based on the research of 2 negative ions in 16 kinds of vegetable from Hainan Danzhou market. This method is of easy usage, high-speed, good reappearance and the result is satisfactory. The correlation coefficients(r) of NO2- and NO3- were 0.9998 and 0.9991. Relative standard deviations (RSD) were 0.65% and 0.04%, respectively.By the determination of NO2-, and NO3- in vegetable, the results indicated that the contents of negative ions in different vegetables (the organ for eating) are fairly different.
The impact of extreme climate change on the fluctuation of electricity energy demand——Evidence from China's prefecture-level cities
Authors: Tan Yudong , Jiang Tong , Xiao Hao , Tang Jingyi , Jia Zhen
Published: May 2021

Climate change directly make the demand for electricity diversified and uncertain, which increase the risk of power grid operation. This paper attempts to explore the impact of extreme climate change on the fluctuation of China's electricity energy demand from the perspective of climate change. Based on the panel data of 90 prefecture-level cities in China from 1989 to 2017, the author builds an econometric model to test the impact of extreme low temperature and extreme high temperature on electricity demand. The results show that the occurrence of extreme high temperature weather has a positive effect on residential electricity demand while the emergence of extreme low temperature weather has a negative effect.
Study on the influence of soil moisture and plant roots on slope stability of dump
Authors: Liang Zhanqi , Liu Yanping
Published: May 2021

Under the background of ecological civilization construction and comprehensive promotion of "green mine" construction in China, for the waste dump formed by a large amount of abandoned soil and slag in the process of mineral resource production, it is one of the important contents of mine ecological restoration to restore and reconstruct the ecology, especially the slope vegetation. Based on the origin of the dump, when rainfall or irrigation water infiltrates into the soil, the physical and mechanical properties of slope soil are changed, and the shear strength of soil is continuously reduced, which has a negative impact on the slope stability. In this paper, we take south mining of DaTang open-pit mine as an example, through field investigation and sampling, laboratory analysis and the computer software analysis method, we set up soil shear strength parameters under different soil water content and different depth of plant roots, using the Slope stability of Slope/W module, establishing the model of slope . Based on limit equilibrium theory to calculate the safety factor, it is concluded that under the condition of the bare Slope stability of Slope soil water safety threshold is 14%. The root system of slope vegetation plays an important role in slope stability, in which the effect of leguminous vegetation on slope stability is obviously better than that of gramineous vegetation. When the soil moisture of slope is 20%, the slope stability coefficient can be increased by 7%.
A remote test method for power grid security and stability control system and its engineering application
Authors: Guo Qi , Zhu Yihua , Chang Dongxu , Li Shengnan , Chen Yong , Wu Mingkang
Published: May 2021

Security and stability control (SSC) system or special protection system (SPS) is an important means to ensure the safe operation of power grid. In view of the insufficiency that the current open-loop testing method cannot fully test the SSC system on-site, a remote real-time closed-loop test method is proposed. The solutions of key techniques such as information interaction, remote communication and signal conversion in remote test system are studied. Then the platform architecture and standard interface of the remote test system are designed. A remote test platform for SSC system is developed, and there application modes of the platform is deeply analysed. Finally, taking SSC system of Yunnan AC power outgoing grid as pilot application, experiment of two substations on-site is carried out. The results in practical project further prove the effectiveness of the method presented in this paper.
Research on terrain aerodynamics analysis of power grid structure at different temperature
Authors: Ye Yu , Xu Xunjian , Yang Li , Yi Yusheng
Published: May 2021

The distribution of near-surface meteorological elements will be greatly affected by topography and other factors, such as wind, which making the dynamic structure of the micro-topography area passed by the power transmission and transformation equipment more susceptible to micro-topography climate. The single hill is one of the typical topography in the micro-topography. This paper studies the variation of buoyant flow and temperate circulation in a typical long hilly terrain. Integrating factors such as buoyancy, turbulence and micro-topography, the separation vortex simulation technology is adopted to the special conditions of microtopography climate. The effect of different surface temperatures on the wind field of the power grid is described in detail. Experiments in the thesis show that the difference in surface temperature will directly affect the speedup ratio. Compared with the change of air temperature, when the surface temperature is higher, the acceleration effect is less obvious, but when the surface temperature is lower, the acceleration effect is more obvious.
Wind power short-term prediction over mountain area using a high-resolution WRF model
Authors: Cai Zelin , Feng Tao , Guo Jun , Hu Bo , Wang Lei
Published: May 2021

Accurate wind power prediction are crucial for power-grid integration and load balancing, as well as the safe and stable operation of the power grid. In this study, the relationship between the wind speed and wind power over mountain area is firstly investigated using the observations in Hunan Baiguoshan Mountain, and the fitting equation is proposed to predict the wind power with wind speed. Using the simulation of the WRF model with a 3-kilometer horizontal resolution, its prediction performance for short-term wind power is further analyzed. The results show that a sixth power relationship exists between wind speeds and wind powers over the mountain area. Also, when the wind speed reaches up to about 9.5 m/s (half of the cut-out wind speeds), the wind power is almost up to its rated power (2200 KW). The evolution characteristics of the wind powers predicted by the WRF model resemble that in observations, but the predicted wind powers are larger than that as observations in most time, which results from the overestimated predicted wind speeds like that in observations.
Probabilistic prediction of short term wind power considering temporal and spatial dependence of prediction error
Authors: Sun Yong , Li Zhenyuan , Shi Chaoyu , Li Baoju , Yang Mao
Published: May 2021

The short-term probabilistic prediction of wind power has the characteristics of spatial dependence and time-series dependence. Considering the two characteristics at the same time can improve the prediction level. In this paper, a probabilistic short-term wind power prediction model considering the temporal and spatial dependence of prediction error is proposed. Considering the coupling relationship between the two properties, the NWP(Numerical Weather Prediction) wind speed point prediction error in the historical period is hierarchical clustering, and the empirical distribution model is used to fit the probability distribution of the error under different wind conditions; the cumulative empirical distribution probability value corresponding to the NWP wind speed at the time to be predicted is bootstrap sampling; under the given confidence level, the possible wind speed at each time point to be predicted in the short term is calculated The power fluctuation range of the generator. The test results show that this method can ensure the statistical significance and fitting stability of the sub sample set at the same time, and improve the classification accuracy of the days to be predicted. Compared with considering a single property, the result of probability prediction performs better on multiple evaluation indexes.
Software design of rotating machinery fault diagnosis system based on deep learning
Authors: He Xiaofeng , Liu Xiaofeng , Lu Xiulian , He Lipeng , Ma Yunxiang , Zhang Jiasheng , Yang Tao
Published: May 2021

With the development of Industry 4.0, in order to meet the needs of intelligent fault diagnosis of rotating machinery in the industrial field, this paper developed a fault diagnosis system for rotating machinery based on deep learning and wavelet transform methods. The system is based on the Python language and mainly combines the PyQt graphical interface framework and the TensorFlow machine learning framework to complete the training requirements for historical or online fault data, and perform online monitoring and diagnosis of equipment operating conditions. The diagnostic accuracy of the system test results is more than 95%, the software interface is friendly, the algorithm generalization ability is good, and the reliability is strong. It provides guidance for the diagnosis of rotating machinery.
Research on multifunctional integrated intelligent stair-climbing chair based on ergonomics
Authors: Zhang Man , Huang Jingde , Jiang Chenbo
Published: May 2021

In view of the practical problems faced by the group with travel inconvenience, the wheelchairs in today’s Chinese market can’t meet the needs of society. Taking the integrated function chair as the research object, this paper puts forward the whole structure of the self-help ladder climbing intelligent chair. The chair is designed on the basis of analyzing the working principle of the main and the auxiliary structure. Based on Ergonomics, the composition and driving mode of each core module and auxiliary mechanism are developed, and the three-dimensional model of self-help ladder climbing intelligent chair is established by using UG. Selfhelp intelligent stair-climbing chair is not only conductive to improving the quality of life of special people and easing their family burden, but also has positive significance to the healthy and sustainable development of wheelchair industry.
Influence analysis of beam support mode on linear guide deformation
Authors: Cao Jiangping , Li Gang , Peng Yuanhui , Yang Chang
Published: May 2021

As the basis of carrying guide rail operation, beam support mode has been widely used in high-end manufacturing, equipment, mechanical engineering and other fields. With beam support and rotating structure driving position and attitude changes, flexible three-dimensional space movement can be realized.The key technology of the beam support to drive the branch guide rail is to control the deformation of the guide rail. The deformation of the guide rail mainly affects the guide rail structure, stiffness, supporting mode, driver design and load, etc.When the driving mode, driving position and driving force, guide bracket (including bracket and connection mode) and load (including mass load, load moving position and moving range) are determined,Or affected by the use of the requirements of the adjustment range is very small, the beam support mode becomes the main influencing factor of guide deformation, especially in the rotary state of the branch guide, guide force, deformation, deflection and so on will show different trends, such as the maximum deformation of the driving end may be 26 times.This paper through the analysis of the main parameters affecting the guide rail deformation characteristics, the default part, on the basis of mathematical modeling and simulation analysis with Solidworks software, compare a variety of support and attitude under the guide of stress and deformation, gives the relative deformation degree under different mode, can provide a reference for relevant involved.
Design of a potato stubble cutting machine for side delivery
Authors: Tang Peng , Ren Shiyi , A Jikui , Liu Zheng , Lv Xiaorong
Published: May 2021

In order to solve the problem that the traditional stubble cutting machine of potato is not complete, which the chopped stalks cannot be collected and utilized, a side delivering potato stubble cutting mechanism was designed in this paper. The characteristic is that the cutting, clamping and delivering of potato plant stalks completed by the cooperation of the reel and the triangle-clamping chain, and the strip is laid on the right side of the machine. The machine can manually adjust the height of the cutting table, easy to operate, installed in the front of the tractor.
Research status and application of prefabricated concrete frame joints
Authors: Sha Mo , Liu Ping , Gao Jierui , Ma Hua
Published: May 2021

Prefabricated concrete structure has the advantages of less energy consumption, easy quality control, fast construction speed, good construction site environment, and less contraction crack. As one of the important development directions of building structure at home and abroad, it is not only conducive to the development of China's construction industrialization and the improvement of production efficiency, but also greatly reduces the construction waste. The design of the connection between beam and column in the core plays an important role in the normal use and seismic performance improvement of the whole concrete structure. This paper reviews the research progress of prefabricated concrete frame joints both at home and abroad, introduce some applications of new connection, and analyses the merit and demerit of various connection methods and future development trend, in order to provide design reference for the engineering application of prefabricated concrete structure.
Synthesis and formation mechanism of BN nanotubes catalyzed by Mg through ball milling and annealing process
Authors: Li Yanjiao , Guo Jianfeng , Wang Xinfeng , Wang Han , He Xuan
Published: May 2021

In order to improve the yield of BN nanotubes prepared by ball milling annealing method, a small amount of magnesium was used as catalyst to synthesized boron nitride nanotubes. The results showed that boron nitride nanotubes with high yield, high purity and uniform size were synthesized. The morphology of the synthesized BNNTs is bamboo-like and cylinder-shaped. The diameter of them is about 50 to 150 nm and most of them are 100nm. The length of them is dozens of microns. The existence of end particles indicates that the growth mechanism of BNNTs can be attributed to a gas-liquid-solid growth model. The magnesium catalyzed preparation of boron nitride nanotubes has stable process, high yield and high purity, which is expected to be a good method for large-scale preparation of boron nitride nanotubes.
Snapshot of photovoltaics − March 2021
Authors: Jäger-Waldau Arnulf
Published: May 2021

For the past 10 years, photovoltaic electricity generation has been the fastest-growing power generation source worldwide. It took almost six decades to achieve 100 GW of solar energy capacity in 2012, but the 1 TW barrier is likely to be broken during 2022. Despite the ongoing COVID-19 pandemic, the overall investments in solar energy have increased by 12% to USD 148.6 billion (EUR 125 billion). In 2020, more than 135 GW of new solar photovoltaic electricity generation capacity was installed. The recovery of China, the continuous growths in Europe and the USA as well as new emerging markets were the main drivers. The number of countries installing more than 1 GW annually has increased to 18 in 2020. The continuation of price reductions in the battery storage sector has again resulted in a growing market for local battery storage systems in solar farms as well as decentralised photovoltaic electricity generation systems. Apart from classic electricity use, renewable electricity for the generation of green hydrogen will become more and more important in the future.
Fair insurance premium rate in connected SEIR model under epidemic outbreak
Authors: Chernov Alexey A. , Shemendyuk Aleksandr A. , Kelbert Mark Y.
Published: May 2021

In this paper, we aim to determine an optimal insurance premium rate for health-care in deterministic and stochastic SEIR models. The studied models consider two standard SEIR centres characterised by migration fluxes and vaccination of population. The premium is calculated using the basic equivalence principle. Even in this simple set-up, there are non-intuitive results that illustrate how the premium depends on migration rates, the severity of a disease and the initial distribution of healthy and infected individuals through the centres. We investigate how the vaccination program affects the insurance costs by comparing the savings in benefits with the expenses for vaccination. We compare the results of deterministic and stochastic models.
Validität präoperativ entnommener SARS-CoV-2-Abstriche bei Kindern
Authors: Zaubitzer Lena , Ludwig Sonja , Jungbauer Frederic , Walter Beatrice , Lange Bettina , Rotter Nicole , Schell Angela
Published: May 2021

Hintergrund Aufgrund der eingeschränkten Compliance ist bei Kindern die technisch korrekte Entnahme eines gepoolten Nasopharyngealabstrichs deutlich erschwert. Vor allem bei Operationen im Bereich der oberen Atemwege besteht für alle im Operationssaal Anwesenden infolge der intraoperativen Aerosolbildung ein deutlich erhöhtes Infektionsrisiko für eine Erkrankung an COVID-19. Ziel der Studie ist die Analyse der Validität präoperativ unter im Einzelfall suboptimalen Bedingungen entnommener SARS-CoV-2-Abstriche bei Kindern.

Material und Methoden Retrospektiver Vergleich der PCR-Ergebnisse von präoperativ und intraoperativ abgenommenen SARS-CoV-2-Abstrichen bei 62 Kindern im Zeitraum April – Juli 2020. Das Alter der Kinder lag zwischen einem und 14 Jahren (Median 4,49 Jahre). Insgesamt 56 der 62 untersuchten Operationen wurden hinsichtlich des erhöhten Infektionsrisikos als Risikoeingriffe gewertet. Die PCR-Diagnostik erfolgte 1–2 Tage (bei Notfalleingriffen am selben Tag) präoperativ sowie erneut intraoperativ mittels gepooltem Nasopharyngealabstrich.

Ergebnisse Alle 62 präoperativ abgenommenen Abstriche waren negativ. Abweichend vom präoperativen Testergebnis war ein intraoperativ gewonnener Abstrich positiv.

Schlussfolgerungen Aufgrund eingeschränkter Compliance kann bei Kindern nicht immer von einer korrekten präoperativen Abstrichtechnik (Präanalytik) ausgegangen werden. Infolgedessen sind die Testergebnisse im Hinblick auf eine mögliche SARS-CoV-2-Infektion womöglich inkorrekt. Ausreichende Schutzmaßnahmen für alle im Operationssaal Anwesenden sind daher zwingend erforderlich. Zum Schutz des Personals und zur Prävention möglicher Infektionsketten perioperativ erscheint in dieser Altersgruppe trotz der guten Reproduzierbarkeit der präoperativen Abstrichergebnisse eine erneute intraoperative Testung erwägenswert, falls der präoperative Abstrich unter erschwerten Bedingungen erfolgte oder eine umfassende Anamnese, z. B. vor Notfalleingriffen oder bei Sprachbarriere, nicht möglich ist.
Triarylpyrazole Derivatives as Potent Cytotoxic Agents; Synthesis and Bioactivity Evaluation “Pyrazole Derivatives as Anticancer Agent”
Authors: Sameem Bilqees , Moghadam Ebrahim Saeedian , Darabi Majid , Shahsavari Zahra , Amini Mohsen
Published: May 2021

Background During the last recent years, several anti-cancer agents were introduced for the treatment of diverse kinds of cancer. Despite their potential in the treatment of cancer, drug resistance and adverse toxicity such as peripheral neuropathy are some of the negative criteria of anti-cancer agents and for this reason, the design and synthesis of new anti-cancer agents are important.

Objective Design, synthesis, and anticancer activity evaluation of some pyrazole derivatives.

Methods A series of Target compounds were prepared using multistep synthesis. Their cytotoxic activity against three different human cancer cell lines namely human colon carcinoma cells (HT-29), epithelial carcinoma cells (U-87MG), pancreatic cancerous cells (Panc-1) as well as AGO1522 normal cell line using in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was investigated.

Results 1,3-Diaryl-5-(3,4,5-trimethoxyphenyl)-4,5-dihydro-1H-pyrazole and 1,3-Diaryl-5-(3,4,5-trimethoxyphenyl)- 1H-pyrazole were synthesized in good yields and their structure and purity were confirmed using 1H-NMR, 13C-NMR, and elemental analysis. Generally, the synthesized scaffolds exhibited good cytotoxicity against cancerous cell lines in comparison to the reference standard, paclitaxel. Compounds 3a and 3c, in Annexin V/ PI staining assay, exerted remarkable activity in apoptosis induction in HT-29 cell lines. Both of them also led to cell cycle arrest in the sub-G1 phase which is inconsistent with the results of apoptosis assay.

Conclusion Concerning obtained results, it is interesting to synthesis more pyrazole derivatives as anticancer agents.
Chemoselective Electrochemical Oxidation of Secondary Alcohols Using a Recyclable Chloride-Based Mediator
Authors: Cantillo David , Sommer Florian , Kappe C. Oliver
Published: May 2021

Selective anodic oxidation of alcohols in the presence of other functional groups can be accomplished by using nitroxyl radical mediators. However, the electrochemical chemoselective oxidation of secondary alcohols in the presence of primary alcohols is an unsolved issue. Herein, we report an electrochemical procedure for the selective oxidation of secondary alcohols by using an inexpensive chloride salt that acts as a redox mediator and supporting electrolyte. The method is based on the controlled anodic generation of active chlorine species, which selectively oxidize secondary alcohols to the corresponding ketones when primary hydroxy groups are present. The method has been demonstrated for a variety of substrates. The corresponding ketones were obtained in good to excellent yields. Moreover, the chloride salt can be easily recovered by a simple extraction procedure for reuse, rendering the method highly sustainable.
A Palladium-Catalyzed Oxa-(4+4)-Cycloaddition Strategy Towards Oxazocine Scaffolds
Authors: Garrec Julian , Archambeau Alexis , Scuiller Anaïs , Liu Xueyang , Cordier Marie
Published: May 2021

A Pd-catalyzed oxa-(4+4)-cycloaddition between 1-azadienes and (2-hydroxymethyl)allyl carbonates is described. Aurone-derived azadienes furnished polycyclic 1,5-oxazocines in good yields. Interestingly, linear azadienes have also been involved and yielded monocyclic heterocycles with complete regioselectivity. DFT calculations were carried out to gain insight on this observation.
A New Application of Gelatin Sponge in the Treatment of Hemifacial Spasm by Microvascular Decompression: A Technical Note
Authors: Chang Bowen , Tang Yinda , Wei Xiangyu , Li Shiting
Published: May 2021

Objectives Microvascular decompression (MVD) for facial nerve remains the highly efficient hemifacial spasm (HFS) treatment. Nonetheless, a variety of cases have poor response to MVD. Using Teflon plus gelatin sponge in MVD seems to be a good solution. No existing study has examined the efficacy of using Teflon combined with gelatin sponge during MVD for HFS. Therefore, this study aimed to compare the efficacy of Teflon combined with gelatin sponge in HFS patients relative to that of Teflon alone.

Patients and Methods We retrospectively compared the follow-up results of patients treated with Teflon and gelatin sponge with those treated with Teflon alone previously. Six hundred and eighty-eight primary HFS patients undergoing surgery from January 2010 to January 2018 were retrospectively analyzed. Three hundred and forty-seven cases received simple Teflon, while 342 cases underwent Teflon combined with gelatin sponge.

Results In the Teflon plus gelatin sponge group, the incidences of facial palsy and hearing loss at 1 day, 1 year, and 2 years following surgery was significantly lower than those in the simple Teflon group. Differences in the success rates between Teflon plus gelatin sponge and the simple Teflon group were not statistically significant at 1 day, 1 year, and 2 years after surgery. The recurrence rate in the Teflon plus gelatin sponge group was significantly lower at 2 years.

Conclusion For HFS patients undergoing MVD, using Teflon plus gelatin sponge can remarkably reduce the incidence of recurrence, facial palsy, and hearing loss compared with those using Teflon alone.
Cervical and Thoracic Spondylotic Myelopathies
Authors: Onofrei Ligia V. , Henrie A. Michael
Published: May 2021

Spondylotic myelopathies are among the most common disorders of the spine, yet the clinical and treatment approach is far from standardized. This article discusses our current understanding of the epidemiology, pathophysiology, clinical assessment, natural history, and treatment options in degenerative myelopathies of the cervical and thoracic spine. We additionally review diagnostic modalities including imaging modalities of the spine and neurophysiological tools such as electromyography/nerve conduction studies, somatosensory-evoked potentials, and motor-evoked potentials. Assessment instruments that can be used for the assessment of myelopathies are reviewed, including the Japanese Orthopedic Association (JOA) score, modified-JOA scale, Nurick scale, nine-hole peg test, and 30-m walking test. We also review common disorders that mimic spondylotic myelopathies, as well as helpful diagnostic clues in differentiating spondylotic and nonspondylotic myelopathies.