bluuebunny/crossref_metadata_2025_split huggingface dataset:
The physicochemical properties of chitosan prepared by microwave heating
Authors: Cheng Jiaqi , Zhu Huaping , Huang Jianlian , Zhao Jianxin , Yan Bowen , Ma Shenyan , Zhang Hao , Fan Daming 
Published: March 2020

AbstractThe aim of this study was to compare the physicochemical properties of chitosan prepared by microwave and water bath heating with an equivalent quantity of heat intake. The structure and physicochemical properties of the chitosan obtained by these two methods were characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray diffractometry (XRD), gel permeation chromatography (GPC), and scanning electron microscopy (SEM). The FTIR and XRD patterns show that there was no significant difference in the structure of chitosan produced by the two heat sources. The results showed that chitosan with 73.86% deacetylation was successfully prepared by microwave heating within 60 min, while a longer time of 180 min was required for the preparation of chitosan with the same deacetylation degree (74.47%) using the conventional heating method under the same heating rate. Even under the same temperature conditions, microwave technology can greatly reduce the reaction time by approximately 1/3, while the chitosan produced by microwaves can obtain relatively low molecular weight and viscosity. These results showed that microwaves may efficiently promote complete chemical reactions by the friction heating mechanism generated by molecular vibration beyond a rapid heating source, turning into a more efficient, energy‐saving, and environmentally friendly method for the further use of rigid shrimp shells and highly crystalline crustacean materials.
The Chemistry of Porous Polymers: The Holey Grail
Authors: Silverstein Michael S. 
Published: March 2020

AbstractPorous polymers have been evolving continuously since the introduction of foam rubber in 1929. Today, pore diameters ranging from sub‐nanometre to millimetre can be generated controllably. Cutting‐edge porous polymers are now being applied at the forefront of critical problems with societal and environmental impact including advanced systems for biomedicine, water purification, energy storage, and gas purification and storage. The commonly‐used pore generation approaches include macromolecular design, self‐assembly, phase separation, solid and liquid templating, sol‐gel formation, and foaming. In each, The Chemistry of Polymers, both the polymerization chemistry and the macromolecular structural chemistry, must be applied advantageously to generate the empty volume within the polymer and then fix it in place. This essay will traverse the various pore size scales, describing the chemistries involved and discussing their implications.
Effect of current guidelines on prevention of pre‐eclampsia with low‐dose aspirin in primary settings: A population‐based case–control study
Authors: Premru‐Srsen Tanja , Kocic Zorana , Verdenik Ivan 
Published: March 2020

AbstractObjectiveTo evaluate the effect of low‐dose aspirin, which was administered at or before the 16th week of pregnancy due to maternal characteristics and history of a pre‐existing medical condition, on prevention of pre‐eclampsia, and on the birth of a small‐for‐gestational‐age (SGA) neonate without pre‐eclampsia in nulliparas in primary settings.MethodsWe performed a case–control study using population‐based data on 47 271 nulliparas with a singleton pregnancy who delivered in Slovenia from 2013 to 2017. The treated group received low‐dose aspirin. For the untreated group, propensity score matching was used to perform a 1:1 matching. In the matched sample, we calculated the odds ratios (OR) with a 95% confidence interval (95% CI) with a two‐way test for pre‐eclampsia, as well as SGA neonates.ResultsIn the treated group (n=584), the odds for an SGA neonate were significantly increased by 42.7% (OR 1.427, 95% CI 1.001–2.034). However, we found no significant effect on the odds for pre‐eclampsia (OR 1.308, 95% CI 0.847–2.022).ConclusionsIn anticipation of more substantial population‐based data studies, in the Slovenian population, preventive treatment with low‐dose aspirin due to maternal characteristics and history of a pre‐existing medical condition is not beneficial for the prevention of pre‐eclampsia and can harm fetal growth.
Estimation of firm‐level productivity in the presence of exports: Evidence from China's manufacturing
Authors: Malikov Emir , Zhao Shunan , Kumbhakar Subal C. 
Published: March 2020

SummaryMotivated by the long‐standing interest of economists in understanding the nexus between firm productivity and export behavior, this paper develops a novel structural framework for control‐function‐based nonparametric identification of the gross production function and latent firm productivity in the presence of endogenous export opportunities that is robust to recent unidentification critiques of proxy estimators. We provide a workable identification strategy, whereby the firm's degree of export orientation provides the needed (excluded) relevant independent exogenous variation in endogenous freely varying inputs, thus allowing us to identify the production function. We estimate our fully nonparametric instrumental variable model using the Landweber–Fridman regularization with the unknown functions approximated via artificial neural network sieves with a sigmoid activation function, which are known for their superior performance relative to other popular sieve approximators, including the polynomial series favored in the literature. Using our methodology, we obtain robust productivity estimates for manufacturing firms from 28 industries in China during the 1999–2006 period to take a close look at China's exporter productivity puzzle, whereby exporters are found to exhibit lower productivity levels than nonexports.
Chronic Kidney Disease Increases the Risk of Hip Fracture: A Prospective Cohort Study in Korean Adults
Authors: Kim Se Hwa , Yi Sang-Wook , Yi Jee-Jeon , Kim Yoo Mee , Won Young Jun 
Published: March 2020

ABSTRACT
This study was conducted to examine the association between renal function and hip fracture. We followed up 352,624 Korean adults, who participated in health examinations during 2009–2010 until 2013. Kidney function was assessed by creatinine-based estimated glomerular filtration rate (eGFR) and albuminuria using urine reagent strip results. The incidence of hip fracture was examined by hospital discharge records. Hazard ratios (HRs) for hip fracture were calculated using Cox proportional hazard models after adjusting for multiple confounders. During a mean follow-up of 4.0 years, 1177 participants suffered a hip fracture. Lower eGFR and more severe albuminuria were associated with a higher risk of hip fracture. The HRs for hip fracture were 1.89 (95% confidence interval [CI] 1.47–2.43) and 3.75 (95% CI 2.30–6.11) among participants with eGFRs of 30 to 44 and 15 to 29 mL/min/1.73m2 relative to those with an eGFR ≥60 mL/min/1.73m2, respectively. The HRs were 1.30 (95% CI 1.02–1.65) for moderate albuminuria and 1.58 (95% CI 1.07–2.35) for severe albuminuria (p for trend = 0.002). Participants with albuminuria had a higher risk of hip fracture than those without albuminuria, even when they belonged to the same eGFR category (HR = 1.75 versus 3.30 for an eGFR of 30 to 44 mL/min/1.73m2; HR = 2.72 versus 7.84 for an eGFR of 15 to 29 mL/min/1.73m2). The effects of each 10 mL/min/1.73m2 decrease in eGFR were stronger with advancing albuminuria severity (pinteraction = 0.016). In conclusion, both low eGFR and albuminuria were risk factors for incident hip fracture in Korean adults. Moreover, these factors exerted a synergistic effect on the risk of hip fracture. © 2020 American Society for Bone and Mineral Research.
Pregnancy-Related Bone Mineral and Microarchitecture Changes in Women Aged 30 to 45 Years
Authors: Ó Breasail Mícheál , Prentice Ann , Ward Kate 
Published: March 2020

ABSTRACTAt birth, the neonatal skeleton contains 20 to 30 g calcium (Ca). It is hypothesized maternal bone mineral may be mobilized to support fetal skeletal development, although evidence of pregnancy-induced mineral mobilization is limited. We recruited healthy pregnant (n = 53) and non-pregnant non-lactating (NPNL; n = 37) women aged 30 to 45 years (mean age 35.4 ± 3.8 years) and obtained peripheral quantitative computed tomography (pQCT) and high-resolution pQCT (HR-pQCT) scans from the tibia and radius at 14 to 16 and 34 to 36 weeks of pregnancy, with a similar scan interval for NPNL. Multiple linear regression models were used to assess group differences in change between baseline and follow-up; differences are expressed as standard deviation scores (SDS) ± SEM. Decreases in volumetric bone mineral density (vBMD) outcomes were found in both groups; however, pregnancy-related decreases for pQCT total and trabecular vBMD were −0.65 ± 0.22 SDS and −0.50 ± 0.23 SDS greater (p &lt; .05). HR-pQCT total and cortical vBMD decreased compared with NPNL by −0.49 ± 0.24 SDS and −0.67 ± 0.23 SDS, respectively; trabecular vBMD decreased in both groups to a similar magnitude. Pregnancy-related changes in bone microarchitecture significantly exceeded NPNL change for trabecular number (0.47 ± 0.23 SDS), trabecular separation (−0.54 ± 0.24 SDS), cortical thickness (−1.01 ± 0.21 SDS), and cortical perimeter (0.78 ± 0.23 SDS). At the proximal radius, cortical vBMD and endosteal circumference increased by 0.50 ± 0.23 SDS and 0.46 ± 0.23 SDS, respectively, compared with NPNL, whereas cortical thickness decreased −0.50 ± 0.22 SDS. Pregnancy-related decreases in total and compartment-specific vBMD exceed age-related change at the distal tibia. Changes at the radius were only evident with pQCT at the cortical-rich proximal site and suggest endosteal resorption. Although the magnitude of these pregnancy-related changes in the appendicular skeleton are small, if they reflect global changes across the skeleton at large, they may contribute substantially to the Ca requirements of the fetus. © 2020 Crown copyright. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.
Identification of functional circRNA/miRNA/mRNA regulatory network for exploring prospective therapy strategy of colorectal cancer
Authors: Xu Dongping , Wu Yutong , Wang Xiufang , Hu Xiaoyun , Qin Wenyan , Li Yalun , Wang Yilin , Zhang Zhen , Lu Senxu , Sun Tong , Wu Zhikun , Fu Dandan , Fu Boshi , Zhang Jing , Chen Qiuchen , Wei Minjie , Zhao Lin , Wu Huizhe 
Published: March 2020

AbstractCircular RNA (circRNA) has been reported to have great scientific significance and clinical value in multiple cancers including colorectal cancer (CRC). However, the biological function of most circRNAs in CRC is still in its infancy. Herein, we discovered the differential expressed circRNAs (DECs) between CRC tissues and matched adjacent using deep RNA sequencing and further confirmed the DECs expression by combining with another Gene Expression Omnibus dataset. Furthermore, we validated the expression of the top four upregulated circRNAs (hsa_circ_0030632, hsa_circ_0004887, hsa_circ_0001550, and hsa_circ_0001681) in both of paired CRC tissues and CRC cell lines. Then, a circRNA/microRNA/messenger RNA regulatory network was established and the Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed these four circRNAs participated in various biological processed including apoptotic process and multiple metabolic processes. Moreover, based on the regulatory network, three bioactive compounds (pergolide, pivampicillin, and methylergometrine) for the treatment of CRC were also found. In conclusion, this study improved our understanding of circRNAs and may also facilitate the finding of promising targets and biomarkers in CRC.
Rare earth–porphyrin complex catalysts for transforming CO2 into cyclic carbonate under mild conditions
Authors: Wang Wenzhen , Fan Wei , Jia Xingang , Li Leilei 
Published: March 2020

AbstractA series of rare earth metal complexes RE(TPP)(acac) (RE = NdIII, YbIII, EuIII, ErIII, PrIII, and LuIII; TPP = 5,10,15,20‐tetraphenylporphyrin) were synthesized and characterized via UV–vis, IR, and elemental analyses. Their catalytic activities on the synthesis of cyclic carbonates from carbon dioxide and epoxides under different reaction conditions (temperature, pressure, and reaction time) were investigated. Catalytic reaction tests showed that the complex Lu(TPP)(acac) could significantly enhance the catalytic reactivity under mild conditions without any co‐solvent.
CircRNA_103762 promotes multidrug resistance in NSCLC by targeting DNA damage inducible transcript 3 (CHOP)
Authors: Xiao Guanhua , Huang Wenqi , Zhan Yongzhong , Li Jing , Tong Wancheng 
Published: March 2020

AbstractBackgroundCircRNAs have been found to play crucial roles in multiple tumor including non‐small cell lung cancer (NSCLC). Here, we researched the correlation between circRNA_103762 and chemotherapy resistance.MethodsRT‐PCR assay was performed to detect circRNA_103762 and DNA damage inducible transcript 3 (CHOP) expression. CCK8 assay was performed to examine cell proliferation and IC50 of different drug. Migration and invasion assay was used to detect cell migration and invasion.ResultsIn our study, circRNA_103762 expression was upregulated in NSCLC tissues and cell. Knockdown of circRNA_103762 can inhibited cell proliferation, migration and invasion in NSCLC. In addition, downregulation of circRNA_103762 promoted CHOP expression and inhibited multidrug resistance (MDR) in NSCLC.ConclusionTogether, we demonstrated that circRNA_103762 is upregulated in NSCLC and functions as an oncogene in NSCLC, and circRNA_103762 enhanced MDR by inhibited CHOP expression in NSCLC cells. These results will help us understand the MDR of NSCLC, providing better effective therapy strategies for patients.
Electrochemical oxidation of the pesticide nitenpyram using a Gd‐PbO2 anode: operation parameter optimization and degradation mechanism
Authors: Yang Yang , Xia Yun , Wei Feng , Zhang Liman , Yao Yingwu 
Published: March 2020

AbstractBACKGROUNDNitenpyram is a neonicotinoid insecticide widely used in agriculture and horticulture, which is stable and builds up in wastewater, causing serious environmental concerns. In this work, the process of advanced electrochemical oxidation for degrading nitenpyram was investigated in detail. The influences of operation parameters (including applied current density, initial nitenpyram concentration, Na2SO4 concentration and pH value) on the electrochemical removal of nitenpyram and its relative degradation mechanism were studied by a gadolinium‐doped lead dioxide (Gd‐PbO2) anode.RESULTSThe results demonstrated that the electrochemical oxidation of nitenpyram follows pseudo‐first‐order reaction kinetics under different operation conditions. After that, 95.44% of nitenpyram and 79.22% of COD could be eliminated from 0.15 mol L−1 Na2SO4 solution dissolving 75 mg L−1 nitenpyram under 70 mA cm−2 at pH = 5.0. Ultimately, high‐performance liquid chromatography (HPLC) and HPLC/mass spectroscopy (MS) were adopted to discover the degradation by‐products during the nitenpyram oxidization process, and up to 14 by‐products were successfully identified. Then a typical nitenpyram degradation pathway was proposed based on these by‐products, comprising two divided parallel sub‐routes. Indirect electrochemical oxidation was responsible for nitenpyram degradation by Gd‐PbO2 anode, and hydroxyl radicals were the main reactive oxygen species.CONCLUSIONThe Gd‐PbO2 electrode presented remarkable performance in nitenpyram degradation. Therefore, the electrochemical oxidation method by Gd‐PbO2 anode is considered to be a very promising and practical mode of herbicide wastewater treatment. © 2020 Society of Chemical Industry
Fabrication of a ternary carbon dots/CoO/g‐C3N4 nanocomposite photocatalyst with enhanced visible‐light‐driven photocatalytic hydrogen production
Authors: Shi Weilong , Wang Jingbo , Yang Shuang , Lin Xue , Guo Feng , Shi Junyou 
Published: March 2020

AbstractBACKGROUNDPhotocatalytic hydrogen (H2) production using sunlight is a promising solution for obtaining clean renewable energy. Therefore, the study of efficient, nontoxic and stable photocatalysts is very important.RESULTSA novel ternary carbon dots/cobalt monoxide/graphitic carbon nitride (CDs/CoO/g‐C3N4) composite photocatalyst was prepared by a simple solvothermal method for photocatalytic H2 production under visible light irradiation (λ > 420 nm). Compared with single semiconductors CoO and g‐C3N4, and binary composite CoO/g‐C3N4, the ternary CDs/CoO/g‐C3N4 nanocomposite exhibited higher photocatalytic performance. The optimal photocatalytic H2 rate of CDs/CoO/g‐C3N4 photocatalyst was 987.4 μmol g−1·h−1 with the apparent quantum efficiency of 2.39% at 420 nm. This enhanced photocatalytic activity can be attributed to the synergy effect of strong absorption and electron buffer property of CDs as well as the merits of the internal heterojunction formed between CoO and g‐C3N4.CONCLUSIONSThis work provides a new approach to the design of a high‐efficiency composite photocatalyst for converting solar energy into chemical fuel. © 2020 Society of Chemical Industry
West Nile neuroinvasive disease. Report of four cases in Northern Greece, 2018
Authors: Papagiannis Ioannis , Tsolaki Magda , Kiryttopoulos Andreas , Antoniadi Eleni , Kyriakogianni Chrysanthi , Fotiou Dimitrios , Notas Konstantinos , Liougka Evangelia , Myrou Athina , Hatzitolios Apostolos , Haloudis Pantelis , Papaioannou Maria , Spilioti Martha , Papa Anna , Tegos Thomas 
Published: March 2020

AbstractWest Nile virus (WNV) is a mosquito‐borne RNA flavivirus which caused several epidemics worldwide. The year 2018 was a WNV record year for Europe, including Greece, with earlier and longer transmission season with higher than the previous number of cases. It has been proposed that some simple biochemical markers may be helpful for the recognition of WNV neuroinvasive disease, its differential from other neurological infectious diseases and prognosis. We describe four cases that suffered from WNV meningitis and/or encephalitis hospitalized in 2018 in a tertiary hospital in Thessaloniki, Greece, and investigate the importance of simple biomarkers for the recognition of WNV etiology.
Field‐matching at the compact SIW horn antenna aperture using genetic algorithm
Authors: Mohammadi‐Parastoo Mahdi , Mohammad‐Ali‐Nezhad Sajad , Saviz Soorena 
Published: March 2020

AbstractA compact substrate integrated waveguide (SIW) horn antenna is proposed with improvements in antenna gain and back lobe level. By pixelating the metal part of the antenna aperture and considering the presence or absence of metal in each pixel using Genetic Algorithm (GA), the electromagnetic field distribution could be controlled especially in the front panel of the antenna. As a result, an increase of 4 dBi occurs in gain and back lobe level is 10.8 dB better than the conventional SIW horn antenna. The proposed antenna works at the frequency of 30.2 GHz and without adding any parts to conventional SIW Horn antenna we do not leave the antenna in compact mode. In order to verify the simulation results, two commercial software has been used and the results are good both in CST and HFSS.
Tumor Proliferation and Invasiveness Derived From Ultrasound Appearances of Invasive Breast Cancers
Authors: Li Jia‐Wei , Tong Yu‐Yang , Zhou Jin , Shi Zhao‐Ting , Sun Pei‐Xuan , Chang Cai 
Published: March 2020

ObjectivesTo investigate the correlation between ultrasound (US) appearances of invasive breast cancers and tumor proliferation and invasiveness measured according to the histologic grade, Ki‐67 expression, axillary lymph node metastasis (ALNM), and lymphovascular invasion (LVI).MethodsThis study evaluated 676 patients who underwent primary surgical treatment of invasive breast cancers. The preoperative US reports and postoperative pathologic and immunohistochemical results of the patients were retrospectively reviewed. Ultrasound characteristics were evaluated according to the American College of Radiology Breast Imaging Reporting and Data System (BI‐RADS) lexicon. Logistic regression analyses were used to identify independent predictive US features that were correlated with tumor proliferation and invasiveness of breast cancers. Odds ratios (ORs) were calculated.ResultsPosterior acoustic enhancement and calcifications on US images were independent predictive factors of a higher histologic grade and a higher Ki‐67 level (OR, 1.69–6.54; P < .05). Meanwhile, a noncircumscribed margin (OR, 2.61; P < .05) and posterior acoustic shadow (OR, 1.62; P < .05) were independent predictors of ALNM. An irregular shape (OR, 2.13; P < .05) and calcifications (OR, 1.69; P < .05) were independent risk factors for LVI. Infiltrative breast cancers scored as BI‐RADS category 5 had higher probability to be associated with ALNM (OR, 3.33; P < .0005) and LVI (OR, 2.87; P < .0005).ConclusionsUltrasound features of invasieve breast cancers might have a predictive value for tumor proliferation and invasiveness. The US features correlated with a high cellular proliferation rate were different from those associated with ALNM. The tumor shape, margin, posterior acoustic pattern, and calcifications at US are suggested to be considered by clinicians when making clinical decisions.
Characterization of a PLDζ2 Homology Gene from Developing Castor Bean Endosperm
Authors: Tian Bo , Sun Meijuan , Jayawardana Kethmi , Wu Ding , Chen Guanqun 
Published: March 2020

AbstractCastor oil contains approximately 90% ricinoleic acid (RA) which is stored mainly in the form of tri‐ricinoleic acid containing triacylglycerols (TAG). Ricinoleate is synthesized from oleate (18:1n‐9) esterified to the sn‐2 position of phosphatidylcholine (PtdCho) catalyzed by oleoyl‐12‐hydroxylase. PtdCho‐derived diacylglycerol (DAG) is an important substrate pool for TAG synthesis, and the interconversion between PtdCho and DAG has been shown to play a critical role in channeling hydroxy fatty acids (HFA) to TAG. Although phospholipase D (PLD) has been reported to catalyze the hydrolysis of PtdCho to produce phosphatidic acid which can then be converted to DAG, its potential functions in the channeling of RA from PtdCho to DAG and the assembly of RA on TAG is largely unknown. In the present study, 11 PLD genes were identified from the Castor Bean Genome Database. Gene expression analysis indicated that RcPLD9 is expressed at relatively high levels in developing seeds compared to other plant tissues. Sequence and phylogenetic analyses revealed that RcPLD9 is a homolog of Arabidopsis PLDζ2. Overexpression of RcPLD9 in the Arabidopsis CL7 line producing C18‐HFA resulted in RA content reductions in the polar lipid fraction (mainly PtdCho) and mono‐HFA‐TAG, but increased RA content in di‐HFA‐TAG. Since part of RA in di‐HFA‐TAG is derived from HFA‐DAG, the results indicated that RcPLD9 facilitates the channeling of RA from PtdCho to DAG for its assembly on TAG in developing seeds.