bluuebunny/crossref_metadata_2025_split huggingface dataset:
Facile Approach toC‐Glucosides by Using a Protecting‐Group‐Free Hiyama Cross‐Coupling Reaction: High‐Yielding Dapagliflozin Synthesis
Authors: Vaňková Karolína , Rahm Michal , Choutka Jan , Pohl Radek , Parkan Kamil 
Published: May 2021

AbstractAccess to unprotected (hetero)aryl pseudo‐C‐glucosides via a mild Pd‐catalysed Hiyama cross‐coupling reaction of protecting‐group‐free 1‐diisopropylsilyl‐d‐glucal with various (hetero)aryl halides has been developed. In addition, selected unprotected pseudo‐C‐glucosides were stereoselectively converted into the corresponding α‐ and β‐C‐glucosides, as well as 2‐deoxy‐β‐C‐glucosides. This methodology was applied to the efficient and high‐yielding synthesis of dapagliflozin, a medicament used to treat type 2 diabetes mellitus. Finally, the versatility of our methodology was proved by the synthesis of other analogues of dapagliflozin.
DNA‐Intercalative Platinum Anticancer Complexes Photoactivated by Visible Light
Authors: Shi Huayun , Kasparkova Jana , Soulié Clément , Clarkson Guy J. , Imberti Cinzia , Novakova Olga , Paterson Martin J. , Brabec Viktor , Sadler Peter J. 
Published: May 2021

AbstractPhotoactivatable agents offer the prospect of highly selective cancer therapy with low side effects and novel mechanisms of action that can combat current drug resistance. 1,8‐Naphthalimides with their extended π system can behave as light‐harvesting groups, fluorescent probes and DNA intercalators. We conjugated N‐(carboxymethyl)‐1,8‐naphthalimide (gly‐R‐Nap) with an R substituent on the naphthyl group to photoactive diazido PtIV complexes to form t,t,t‐[Pt(py)2(N3)2(OH)(gly‐R‐Nap)], R=H (1), 3‐NO2 (2) or 4‐NMe2 (3). They show enhanced photo‐oxidation, cellular accumulation and promising photo‐cytotoxicity in human A2780 ovarian, A549 lung and PC3 prostate cancer cells with visible light activation, and low dark cytotoxicity. Complexes 1 and 2 exhibit pre‐intercalation into DNA, resulting in enhanced photo‐induced DNA crosslinking. Complex 3 has a red‐shifted absorption band at 450 nm, allowing photoactivation and photo‐cytotoxicity with green light.
Enhancing the Mechanical Performance of Reduced Graphene Oxide Aerogel with Cellulose Nanofibers
Authors: Yao Chenfei , Yi Jiwang , Lai Haihong , Shi Ge , Hu Yijie , Chen Zehong , Zhai Junye , Wang Xiaohui , Zhong Linxin , Liu Chuanfu 
Published: May 2021

AbstractUltralight, highly compressible and superelastic carbon materials hold great promise in wearable and flexible electronic devices, but the fabrication remains to be a challenge because of the brittleness nature of carbon. Herein, a carbon aerogel with ultralow density yet high mechanical performance is successfully fabricated from graphene oxide (GO) liquid crystal stabilized bubbles with the enhancement of cellulose nanofiber (CNF). The incorporation of CNF into reduced graphene oxide (rGO) nanosheets enhances the interaction among rGO nanosheets through welding effect, which restricts the slip of rGO nanosheets and the detachment among microspheres, leading to a significant improvement on mechanical properties. The as‐prepared carbon aerogel with tightly packaged cell‐wall architecture displays ultrahigh compressibility (up to 99% strain) and elasticity (90.1% stress retention and 99.0% height retention after 10000 cycles at 50% strain), which are superior to those of the present bubble‐templated carbon aerogels and many other carbon materials through various methods. The structural feature leads to rapid and stable current response and high sensitivity to external strain and pressure, allowing the carbon aerogel to detect very small pressure and various human motions from finger bending to pulse. These advantages make the carbon aerogel promising for flexible electronic devices.
Algorithm for reasoning with words based on linguistic fuzzy cognitive map
Authors: Han Nguyen , Cong Hao Nguyen 
Published: May 2021

SummaryIn this paper, we introduce a method for reasoning with words based on hedge algebra using linguistic cognitive map (). Our model consists of a set of vertices and edges whose values are linguistic variables that are constrained by a linguistic lattice. The algorithm for the system studied consists of fuzzification, reasoning, and defuzzification. Further, the total effect between any two vertices in the is computed.
Crystallization and Morphology of Pb0.92La0.08(Zr0.68Ti0.32)0.98O3 Powders Synthesized Using the Gel‐Hydrothermal Process
Authors: Zong Xingsheng , He Xiyun , Zeng Xia , Qiu Pingsun , Ling Liang , Shi Ying 
Published: May 2021

AbstractPure perovskite Pb0.92La0.08(Zr0.68Ti0.32)0.98O3 (PLZT (8/68/32)) crystal powders with good dispersibility are prepared by using gel‐hydrothermal method. The effects of mineralizer concentration, hydrothermal treatment time, and excess lead content on powder crystallization and morphology are examined and analyzed. The suitable mineralizer concentration and hydrothermal treatment time are found to be helpful to promote the PLZT crystal powders growth and improve the particle surface morphology. Noticeably, the introduction of excessive Pb can well compensate for the lack of A‐site ions in the solution, thereby promoting the formation of rhombohedral PLZT crystal powders. The following optimized hydrothermal conditions are established: the temperature ≈230 °C, the mineralizer concentration ≈2 m, the hydrothermal treatment time ≈24 h, and the amount of excess Pb ≈ 80%. The obtained PLZT crystal powders with clean and complete cube morphology, uniform particle size, and excellent dispersibility would be used as the crystal seeds applying in the seed‐induced growth of PLZT ceramics.
CircMYBL2 regulates the resistance of cervical cancer cells to paclitaxel via miR‐665‐dependent regulation of EGFR
Authors: Dong Mingqiang , Li Peng , Xie Yuquan , Wang Zhihua , Wang Rui 
Published: May 2021

AbstractCircular RNAs are considered to be associated with cancer resistance. This study aims to investigate the function and mechanism of circMYBL2 in paclitaxel (PTX) resistance of cervical cancer (CC). The expression of circMYBL2, miR‐665 and epidermal growth factor receptor (EGFR) was investigated using quantitative real‐time polymerase chain reaction assay. Cell viability, cell colony number, cell proliferation, apoptosis and lactate dehydrogenase (LDH) were detected by 3‐(4, 5‐Dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide, colony formation, 5‐ethynyl‐2′‐deoxyuridine incorporation, flow cytometry and LDH release assays, respectively. The interaction between miR‐665 and circMYBL2 or EGFR was confirmed by dual‐luciferase reporter assay. The protein expression levels were quantified by western blot or immunohistochemistry assay. Mice xenograft models were constructed to investigate the effect of circMYBL2 on CC tumor growth. CircMYBL2 was upregulated in CC tissues and cells, especially in PTX‐resistant CC tissues and cells, and it was a stable circRNA mainly distributed in the cytoplasm. CircMYBL2 could enhance the PTX resistance of CC cells in vitro and promote CC tumor growth in vivo. Mechanistically, circMYBL2 could inhibit the PTX sensitivity and promote cell malignant behaviors in PTX‐sensitive and PTX‐resistant CC cells via upregulating EGFR mediated by miR‐665. CircMYBL2 played a positive role in the PTX resistance and malignant activities of PTX‐sensitive and PTX‐resistant CC cells by regulating the miR‐665/EGFR network, providing a novel therapeutic strategy for the treatment of CC patients resistant to PTX.
CG11426 gene product negatively regulates glial population size in the Drosophila eye imaginal disc
Authors: Rhee Jong‐Eun , Choi Jin‐Hyeon , Park Jae H. , Lee Gyunghee , Pak Banya , Kwon Seung‐Hae , Jeon Sang‐Hak 
Published: May 2021

AbstractGlial cells play essential roles in the nervous system. Although glial populations are tightly regulated, the mechanisms regulating the population size remain poorly understood. Since Drosophila glial cells are similar to the human counterparts in their functions and shapes, rendering them an excellent model system to understand the human glia biology. Lipid phosphate phosphatases (LPPs) are important for regulating bioactive lipids. In Drosophila, there are three known LPP‐encoding genes: wunen, wunen‐2, and lazaro. The wunens are important for germ cell migration and survival and septate junction formation during tracheal development. Lazaro is involved in phototransduction. In the present study, we characterized a novel Drosophila LPP‐encoding gene, CG11426. Suppression of CG11426 increased glial cell number in the eye imaginal disc during larval development, while ectopic CG11426 expression decreased it. Both types of mutation also caused defects in axon projection to the optic lobe in larval eye–brain complexes. Moreover, CG11426 promoted apoptosis via inhibiting ERK signaling in the eye imaginal disc. Taken together, these findings demonstrated that CG11426 gene product negatively regulates ERK signaling to promote apoptosis for proper maintenance of the glial population in the developing eye disc.
Selective Nitration of Open‐Cage [60]Fullerene Derivatives by Ponzio Reaction
Authors: Zhang Hao , Gao Rui , Liu Zhen , Wang Xiaoge , Su Jie , Gan Liangbing 
Published: May 2021

AbstractThe carbonyl group on the rim of open‐cage C60 derivative was converted into an oxime group when treated with hydroxylamine. Nitrogen tetroxide could convert the oxime group into gem‐dinitro groups, similar to the Ponzio reaction of classical organic compounds. Single crystal X‐ray diffraction data shows that one of the nitro group is directly above the orifice acting as an effective stopper. Presence of the gem‐dinitro groups also showed significant effect on the reactivity of other functional groups on the rim of the orifice.
International connectivity and the location of multinational enterprises'knowledge‐intensiveactivities: Evidence fromUSmetropolitan areas
Authors: Castellani Davide , Lavoratori Katiuscia , Perri Alessandra , Scalera Vittoria G. 
Published: May 2021

AbstractResearch summaryInternational connectivity is a multidimensional construct that plays a pivotal role in attracting the activities of multinational enterprises (MNEs) by facilitating intra‐firm coordination and access to external resources. We conceptualize how the different dimensions of international connectivity determine the location of MNEs' knowledge‐intensive activities, with a focus on Research and Development (R&D) laboratories and Headquarter units (HQ). By analyzing 3,101 greenfield investments of MNEs in US Metropolitan Statistical Areas, we show that R&D activities are attracted toward areas connected to the rest of the world by international networks of inventors. Moreover, we find that infrastructures which ensure the mobility of people across borders, and greater connectivity through advanced producer services are key location factors for HQ activities.Managerial summaryThe choice of where multinational enterprises (MNEs) locate their knowledge‐intensive activities is a crucial decision for managers, with important implications for policymakers. It has become increasingly clear that MNEs value the extent to which individual locations are connected globally. We study this international connectivity and highlight that it is a multidimensional construct spanning knowledge, infrastructure, and producer service networks. This study shows that not every dimension of international connectivity is equally important for MNEs in locating different knowledge‐intensive activities. Research and Development laboratories are attracted toward areas connected worldwide by international networks of inventors. Moreover, headquarter units are more likely to be established in locations featuring greater connectivity through the mobility of people and advanced producer services.
The complementarity of drug monitoring programs and health IT for reducing opioid‐related mortality and morbidity
Authors: Wang Lucy Xiaolu 
Published: May 2021

AbstractIn response to the opioid crisis, each US state has implemented a prescription drug monitoring program (PDMP) to collect data on controlled substances prescribed and dispensed in the state. I study whether health information technology (HIT) complements patient prescription data in PDMPs to reduce opioid‐related mortality and morbidity. A novel dataset is constructed that records state policies that integrate PDMP with HIT and facilitate interstate data sharing. Using difference‐in‐differences models, I find that PDMP‐HIT integration policies reduce opioid‐related inpatient morbidity. The reductions are substantial in states that established integration without ever mandating the use of a PDMP. A mechanism test suggests that PDMP integration works mainly through the hospital system while a mandate affects legal opioids prescription. The impacts from integration are strongest for the vulnerable groups—middle‐aged, low‐to middle‐income patients, and those with public insurance. There is suggestive evidence that interstate data sharing further complements integration despite not having a significant impact independently. The results are robust to a set of tests using alternative specifications and measures. The total benefits from integration far exceed the associated costs.
The ‘hub and spoke model’ for the management of surgical patients during the COVID‐19 pandemic
Authors: Kasivisvanathan Ramanathan , Tilney Henry S. , Jhanji Shaman , O’Mahony Michelle , Gruber Pascale , Nicol David , Morgan Dominic , Kipps Emma , Rasheed Shahnawaz 
Published: May 2021

AbstractDuring the on‐going COVID‐19 pandemic a number of key public health services have been severely impacted. These include elective surgical services due to the synergetic resources required to provide both perioperative surgical care whilst also treating acute COVID‐19 patients and also the poor outcomes associated with surgical patients who develop COVID‐19 in the perioperative period. This article discusses the important principles and concepts for providing important surgical services during the COVID‐19 pandemic based on the model of the RMCancerSurgHub which is providing surgical cancer services for a population of approximately 2 million people across London during the pandemic. The model focusses on creating local and regional hub centres which provide urgent treatment for surgical patients in an environment that is relatively protected from the burden of COVID‐19 illness. The model extensively utilises the extended multidisciplinary team to allow for a flexible approach with core services delivered in ‘clean’ sites which can adapt to viral surges. A key requirement is that of a clinical prioritisation process which allows for equity in access within and between specialties ensuring that patients are treated on the basis of greatest need, while at the same time protecting those whose conditions can safely wait from exposure to the virus. Importantly, this model has the ability to scale‐up activity and lead units and networks into the recovery phase. The model discussed is also broadly applicable to providing surgical services during any viral pandemic.
Mercury cycling during acid rain recovery at the forested Lesní potok catchment, Czech Republic
Authors: Navrátil Tomáš , Shanley James B. , Rohovec Jan , Dobešová Irena , Matoušková Šárka , Roll Michal , Nováková Tereza , Oulehle Filip 
Published: May 2021

AbstractFrom 2011 to 2019, mercury (Hg) stores and fluxes were studied in the small forested catchment Lesní potok (LES) in the central Czech Republic using the watershed mass balance approach together with internal measurements. Mean input fluxes of Hg via open bulk deposition, beech throughfall and spruce throughfall during the periodwere 2.9, 3.9 and 7.6 μg m−2 year−1, respectively. These values were considerably lower than corresponding deposition Hg fluxes reported in the early years of the 21st century from catchments in Germany. Current bulk precipitation inputs at unimpacted Czech mountainous sites were lower than those in Germany. The largest Hg inputs to the catchment were via litterfall, averaging 22.6 and 17.8 μg m−2 year−1 for beech and spruce stands. The average Hg input, based on the sum of mean litterfall and throughfall deposition, was 23.0 μg m−2 year−1, compared to the estimated Hg output in runoff of 0.5 μg m−2 year−1, which is low compared to other reported values. Thus, only ~2% of Hg input is exported in stream runoff. Stream water Hg was only weakly related to dissolved organic carbon (DOC) but both concentrations were positively correlated with water temperature. The estimated total soil Hg pool averaged 47.5 mg m−2, only 4% of which was in the O‐horizon. Thus Hg in the O‐horizon pool represents 72 years of deposition at the current input flux and 3800 years of export at the current runoff flux. Age‐dating by 14C suggested that organic soil contains Hg from recent deposition, while mineral soil at 40–80 cm depth contained 4400‐year old carbon, suggesting the soil had accumulated atmospheric Hg inputs through millennia to reach the highest soil Hg pool of the soil profile. These findings suggest that industrial era intensification of the Hg cycle is superimposed on a slower‐paced Hg cycle during most of the Holocene.
A century of change: Reconstructing the biogeochemical history of Hubbard Brook
Authors: Likens Gene E. , Buso Donald C. , Bernhardt Emily S. , Rosi Emma 
Published: May 2021

AbstractEcosystems constantly adjust to altered biogeochemical inputs, changes in vegetation and climate, and previous physical disturbances. Such disturbances create overlapping ‘biogeochemical legacies’ affecting modern nutrient mass balances. To understand how ‘legacies’ affected watershed‐ecosystem (WEC) biogeochemistry during five decades of studies within the Hubbard Brook Experimental Forest (HBEF), we extended biogeochemical trends and hydrologic fluxes back to 1900 to provide an historical framework for our long‐term studies. This reconstruction showed acid rain peaking at HBEF in the late 1960s‐early 1970s near the beginning of the Hubbard Brook Ecosystem Study (HBES). The long‐term, parabolic arc in acid inputs to HBEF generated a corresponding arc in the ionic strength of stream water, with acid inputs generating increased losses of H+ and soil base cations between 1963 and 1969 and then decreased losses after 1970. Nitrate release after disturbance is coupled with previous N‐deposition and storage, biological uptake, and hydrology. Sulfur was stored in soils from decades of acid deposition but is now nearly depleted. Total exports of base cations from the soil exchange pool represent one of the largest disturbances to forest and associated aquatic ecosystems at the HBEF since the Pleistocene glaciation. Because precipitation inputs of base cations currently are extremely small, such losses can only be replaced through the slow process of mineral weathering. Thus, the chemistry of stream water is extremely dilute and likely to become even more dilute than pre‐Industrial Revolution estimates. The importance of calculating chemical fluxes is clearly demonstrated in reconstruction of acid rain impacts during the pre‐measurement period. The aggregate impact of acid rain on WEC exports is far larger than historical forest harvest effects, and even larger than the most severe deforestation experiment (Watershed 2) at HBEF. A century of acid rain had a calcium stripping impact equivalent to two W2 experiments involving complete deforestation and herbicide applications.
Ferroptosis: A potential therapeutic target for neurodegenerative diseases
Authors: Vitalakumar D. , Sharma Ankita , Flora Swaran J. S. 
Published: May 2021

AbstractFerroptosis is a newly identified regulated form of cell death, which is thought to play a major role in neurodegenerative diseases. In this review, we discuss recent studies elucidating the molecular mechanisms involved in the regulation and execution of ferroptotic cell death and also its role in the brain. Ferroptosis is regulated mainly via iron homeostasis, glutathione metabolism, and lipid peroxidation. Ferroptotic cell death and pro‐ferroptotic factors are correlated with the etiopathogenesis of Parkinson's disease (PD) and Alzheimer's disease (AD). Ferroptosis and etiological factors act synergistically in PD and AD pathogenesis. Furthermore, several preclinical and clinical studies targeting ferroptosis in PD and AD have also shown positive results. Evidence of ferroptosis in the brain thus gives new insights into understanding neurodegenerative diseases. Ferroptosis studies in the brain are still in their infancy, but the existing pieces of evidence suggest a strong correlation between ferroptotic cell death and neurodegenerative diseases. Thus, ferroptosis might be a promising target for treating neurodegenerative diseases.
Three ‐(pyridin‐2‐yl)‐2‐(pyridin‐2‐ylimino)thiazolidin‐4‐one as a novel inhibitor of cerebral MAO‐B activity with antioxidant properties and low toxicity potential
Authors: Carraro Junior Luiz Roberto , Alves Amália Gonçalves , Rech Taís da Silva Teixeira , Campos Júnior José Coan , Siqueira Geonir Machado , Cunico Wilson , Brüning César Augusto , Bortolatto Cristiani Folharini 
Published: May 2021

AbstractSome brain diseases are associated with oxidative stress and altered monoamine oxidase (MAO) activity. The objective of this study was to evaluate the antioxidant and neuroprotective actions through MAO inhibition of 3‐(pyridin‐2‐yl)‐2‐(pyridine‐2‐ylimino) thiazolidin‐4‐one (PPIT, a synthetic molecule containing a thiazolidinone nucleus), as well as its effects on toxicity parameters in Swiss female mice. Five in vitro assays were carried out to verify the PPIT antioxidant capacity: protein carbonylation (PC), 2,2'‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS), 1,1‐diphenyl‐2‐picryl‐hydrazil (DPPH), ferric ion (Fe3+) reducing antioxidant power (FRAP), and superoxide dismutase (SOD)‐like activity. The results showed that PPIT reduced the level of PC in the homogenate of the brain. This compound did not demonstrate SOD mimetic activity, but it acted as a free radical scavenger (ABTS and DPPH) and exhibited reducing activity in the FRAP assay. In addition, the effects of PPIT on cerebral MAO activity (MAO‐A and B isoforms) were investigated in vitro. Our data revealed inhibition of the MAO‐B activity by PPIT with no effects on MAO‐A. Lastly, an acute oral toxicity test was conducted in mice. No changes in food intake, body weight, and biochemical markers of kidney and liver damage were detected in mice treated with a high dose of PPIT (300 mg/kg). In conclusion, the present study demonstrated that PPIT exhibits antioxidant activity and selectively inhibits the MAO‐B isoform without causing apparent toxicity. These findings suggest PPIT as a potential therapeutic candidate to be tested in preclinical models of brain diseases involving perturbations of MAO‐B activity and redox status.
Raman electronic effect for non‐destructive boron calibration in type IIb semiconducting diamond
Authors: Zhang Shengya , Zhang Zhuangfei , Yi Wencai , Chen Xin , Liu Xiaobing 
Published: May 2021

AbstractWhereas p type semiconducting diamond is well‐developed with boron doping, it is still challenge to directly determine boron content within type IIb diamonds in material science. In this work, we show a systematic study on analysis of electronic Raman effect in boron‐doped diamond (BDD) containing boron ranging from several to ~104 ppm. Beside a sharp peak near 5.2 cm−1, a shoulder associated with the Raman electronic effect near 12.1 cm−1 presents in the BDD samples and the intensity is observed to increase significantly with the increasing boron content. Our results demonstrate that the electronic line can be employed as an effective indication for simple, non‐destructive, accurate and broadly applicable boron calibration in semiconducting BDD samples.