bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Stereoconvergent Allylation of Chiral Alkylcopper Nucleophiles with Racemic Allylic Phosphates
Authors: Han Jung Tae , Kim Seoung‐Tae , Baik Mu‐Hyun , Yun Jaesook 
Published: December 2019

AbstractCopper‐catalyzed stereoconvergent allylation of chiral sp3‐hybridized carbon nucleophiles with a racemic mixture of acyclic secondary allylic phosphates is reported. In the presence of a copper‐catalyst complexed with chiral BenzP* ligand, tandem coupling reaction of vinyl arenes, bis(pinacolato)diboron, and racemic allylic phosphates provided β‐chiral alkylboronates possessing (E)‐alkenyl moiety through a direct stereoconvergent allylic coupling with concomitant generation of a C(sp3)‐stereogenic center. A range of vinyl (hetero)arenes and secondary allylic phosphates bearing 1°, 2°, 3° alkyl and phenyl α‐substituents were suitable for the reaction, forming products with high enantioselectivities up to 95 % ee. Density functional theory calculations were conducted in detail to elucidate the origin of the observed regioselectivity of borylcupration and stereoconvergent (E)‐olefin formation from racemic allylic phosphates.
Determination of panthenol enantiomers in cosmetic preparations using an achiral‐chiral–coupled column HPLC system
Authors: Hroboňová Katarína , Lomenova Anna 
Published: December 2019

AbstractA new high‐performance liquid chromatography (HPLC) method for separation and determination of panthenol enantiomers in hair care products was developed. Two types of detectors, low‐wavelength ultraviolet (UV) and polarimetric, were used. Optimized conditions consisted of coupled achiral, amino type, and chiral, amylose tris(3,5‐dimethylphenylcarbamate), stationary phases, mixture of n‐hexane/ethanol (60:40, v/v) as mobile phase under isocratic conditions and flow rate 0.8 cm3 min−1. The effect of column temperature on retention and resolution of enantiomers was studied. The analysis runtime was 10 minutes, and the average retention times for d‐ and l‐panthenol were 7.10 ±0.1 minutes and 8.21 ±0.2 minutes, respectively. The resolution of enantiomers on coupled achiral‐chiral columns was Rs = 2.7. The solid‐phase extraction method was employed for extraction and purification of analytes. The validated method was selective, accurate, and linear (R2 > .998) over the concentration range of 0.001 to 1.0 mg cm−3 for both enantiomeric forms. The limits of detection (LOD) and quantitation (LOQ) of each enantiomer were 0.3 and 1.0 μg cm−3, respectively. The results demonstrated the occurrence of d‐panthenol in hair care products.
Identifying the variables that drive tamoxifen‐independent CreERT2 recombination: Implications for microglial fate mapping and gene deletions
Authors: Van Hove Hannah , Antunes Ana Rita Pombo , De Vlaminck Karen , Scheyltjens Isabelle , Van Ginderachter Jo A. , Movahedi Kiavash 
Published: December 2019

AbstractLigand‐dependent Cre recombinases such as the CreERT2 system allow for tamoxifen‐inducible Cre recombination. Important examples are the Cx3cr1‐CreERT2 and Sall1‐CreERT2 lines that are widely used for fate mapping and gene deletion studies of brain macrophages. Our results now show that both CreERT2 lines can exhibit a high rate of tamoxifen‐independent “leaky” excision with some reporter strains, while this is not observed with others. We suggest that this disparity is determined by the length of the floxed transcriptional STOP cassette that is incorporated in the various reporter lines. In addition, the rate of spontaneous recombination was also determined by the CreERT2 expression levels and the longevity of the CreERT2‐expressing cells. The implications of these results are discussed in the context of fate mapping and inducible gene deletion studies in macrophages and microglia.
Temporal Changes of Phospholipids Fatty Acids and Cholesterol in Breast Milk and Relationship with Diet
Authors: Zhang Niu , Zhuo Cheng‐Fei , Liu Biao , Ye Wen‐Hui , Tao Lin , Zheng Liu‐Feng , Chen Li , Deng Ze‐Yuan , Li Guo‐Yong , Gong Zhi‐Qing , Li Jing 
Published: December 2019

AbstractPhospholipids (PLs) and cholesterol in human milk (HM) are affected by lactation, and differential lipids are closely related to maternal diet. The contents of PLs and cholesterol in Chinese HM are quantified by gas chromatography and high performance liquid chromatography, respectively, and the relationship between differential lipids and the maternal diet is obtained by Pearson. The result shows that SFA, MUFA, and polyunsaturated fatty acid (PUFA) are not affected by lactation and geography for total fatty acids, but almost all sn‐2 fatty acids are influenced by geography and remain unchanged during lactation. Most SFAs show absolute sn‐2 selectivity and the majority of MUFAs and PUFAs are esterified at the sn‐1 position. Cholesterol (13.8–22.6 mg per 100 g milk) and 25‐hydroxycholesterol (0.45–1.01 mg per 100 g milk) increase significantly and remain constant during lactation, respectively, and they are affected by regions. In addition, the differential lipids (22:1n‐9, C9:0, trans‐PUFA, 22:4n‐6, etc.) of PLs are closely related to the maternal diet. PLs and cholesterol content differ from western research and infant formula, which will help to design an infant formula that is more suitable for Chinese babies in the future.Practical Application: Compared with PLs and cholesterol in western countries and infant formula, the specificity of Chinese HM can more accurately target the development of formulas suitable for the growth of Chinese infants. At the same time, according to the influence of the motherʼs diet on the composition of HM, it is more reasonable to guide the diet of the mother.
Elastic instabilities in the electroosmotic flow of non‐Newtonian fluids through T‐shaped microchannels
Authors: Song Le , Yu Liandong , Li Di , Jagdale Purva P. , Xuan Xiangchun 
Published: December 2019

AbstractElectroosmotic flow (EOF) has been widely used to transport fluids and samples in micro‐ and nanofluidic channels for lab‐on‐a‐chip applications. This essentially surface‐driven plug‐like flow is, however, sensitive to both the fluid and wall properties, of which any inhomogeneity may draw disturbances to the flow and even instabilities. Existing studies on EOF instabilities have been focused primarily upon Newtonian fluids though many of the chemical and biological solutions are actually non‐Newtonian. We carry out a systematic experimental investigation of the fluid rheological effects on the elastic instability in the EOF of phosphate buffer‐based polymer solutions through T‐shaped microchannels. We find that electro‐elastic instabilities can be induced in shear thinning polyacrylamide (PAA) and xanthan gum (XG) solutions if the applied direct current voltage is above a threshold value. However, no instabilities are observed in Newtonian or weakly shear thinning viscoelastic fluids including polyethylene oxide (PEO), polyvinylpyrrolidone (PVP), and hyaluronic acid (HA) solutions. We also perform a quantitative analysis of the wave parameters for the observed elasto‐elastic instabilities.
Phytochemical profile and antioxidation activity of annona fruit and its effect on lymphoma cell proliferation
Authors: Al‐Shaya Huda Mohammed , Li Haiwen , Beg Obaid U. , Hamama Anwar A. , Witiak Sarah Melissa , Kaseloo Paul , Siddiqui Rafat A. 
Published: December 2019

AbstractCancers of the lymphatic system are broadly classified into Hodgkin and non‐Hodgkin types. Although lymphomas can be effectively treated with chemotherapy, this approach is associated with the risk of adverse side effects. High intake of certain vegetables and fruits is associated with a reduced risk of cancer development. We hypothesized that Annona fruit, which is rich in fibers and phytochemicals that are known to possess anticancer properties, can be effective in inhibiting lymphoma growth. The Annona fruit's fractions were extracted with water, methanol, or chloroform and then assayed for total phenolic, flavonoids, and tannins content; antioxidation activities; and inhibition of in vitro cell proliferation using the Ramos‐1 lymphoma cells. The methanol fractions contained the highest phenolics, flavonoids, and tannins content, and antioxidation activity. However, the methanol extracts of skin, pulp, and seeds had a moderate whereas the chloroform extracts of pulp and seeds had strong effects on Ramos‐1 cell proliferation. Our findings suggest that Annona fruits may be effective in the prevention or treatment of lymphoma.
Geotechnical characteristics of soft rocks of the Inneralpine Molasse – Brenner Base Tunnel access route, Unterangerberg, Tyrol, Austria
Authors: Erharter Georg H. , Poscher Gerhard , Sommer Peter , Sedlacek Christoph 
Published: December 2019

AbstractThe engineering geological investigation for the environmental impact assessment of the more than 20 km long route section Schaftenau–Radfeld in the Lower Inn Valley (Tyrol) was conducted in 2017/18. As a central structure, a nearly 3 km long tunnel will be built through the Unterangerberg. The bedrock of the Unterangerberg consists of turbiditic, marine deposits of the Inneralpine Molasse with interbedded layers of marl, claystone and sandstone. The proximity to the Inntal shearzone and exogeneous effects like several glaciations have softened the surface of the inherently weak bedrock and led to heterogeneous mechanical properties. The monotonous lithology is therefore accompanied by an inhomogeneous rock mass characterization. This paper describes experiences of the geotechnical investigation of this weak rock. It was observed that only a quick transport of samples from the drilling site to the laboratory can guarantee for test results in accordance with the standards. The results, lying in the transitional zone between soft rock and hard soil, are in good accordance with data from other studies.
Ergonomics risk assessment among maintenance operators in a Tunisian railway company: A case study
Authors: Sebti Riheb , Boulila Atef , Hamza Samir 
Published: December 2019

AbstractRailway truck maintenance plays a crucial role for rail transport. It aims at ensuring the availability of the equipment and the safety of the operations. However, maintenance activities often involve uncommon work and nonroutine tasks and it is obvious that maintenance operators are more threatened than other employees to be exposed to various hazards in their workplace. In Tunisia, the prevalence of occupational accidents and injuries among maintenance workers is not well documented. The target of this cross‐sectional study is to assess ergonomics risks associated with maintenance activities in a railway company. Data collection was carried out through a self‐administrated questionnaire and via direct observations. The Body Parts Symptom Survey (BPSS) was used to identify the discomfort level of the workers. More than 100 maintenance operators working in nine different workshops were involved in this study. From BPSS results, this paper proposed a new method to calculate the discomfort index related to each body part in order to calculate the global discomfort index (GDI) for each workshop. Results showed that the most hazardous workshop was rail‐car maintenance workshop (GDI = 43.06). Four main tasks were assessed with normalized score. Final scores were found to be extremely high. To remedy the raised problems, new adjustable workstations were proposed, which showed a considerable improvement on workers’ postures.
Thermal conductivity of aluminum foam based on 3‐D stochastic sphere model
Authors: Sun Minghan , Fan Meichen , Li Lingxiao , Xu Zhiqiang , Yang Tingsong 
Published: December 2019

AbstractTo accurately characterize the geometric structure of closed‐cell aluminum foam, a three‐dimensional stochastic sphere model with adjustable porosity and pore size was established, and its thermal conductivity was studied by numerical simulation. A closed‐cell aluminum foam heat conduction experiment was designed to verify the accuracy of the model. Using this model, the thermal conductivity of aluminum foam with different pore sizes and porosity was calculated, and the variation of thermal conductivity was studied. The results show that with the same porosity, the thermal conductivity increases linearly with the pore size. With the same pore size, the thermal conductivity decreases linearly with the porosity. The equivalent thermal conductivity decreases with the increase of porosity. According to the simulation results, the formula of equivalent thermal conductivity of aluminum foam is .
Early response evaluation during preoperative chemotherapy for colorectal liver metastases: Combined size and morphology‐based criteria predict pathological response and survival after resection
Authors: Primavesi Florian , Fadinger Nikolaus , Biggel Simon , Braunwarth Eva , Gasser Elisabeth , Sprung Susanne , Göbel Georg , Gassner Eva , Stättner Stefan , Öfner Dietmar 
Published: December 2019

AbstractBackgroundShort treatment‐duration with early restaging is crucial to avoid liver injury after preoperative chemotherapy (preopCTX) for colorectal liver metastases (CRLM). Response evaluation according to response evaluation criteria in solid tumors (RECIST) criteria implies several limitations. Early tumor shrinkage (ETS; ≥20% size reduction <6‐12 weeks) or morphological criteria (MC) may better predict oncological outcome.MethodsIn patients undergoing resection after preopCTX between 2003–2017 pathological and radiological response was reassessed according to Blazer classification, ETS, MC, and RECIST within 90 days and correlated with survival.ResultsSeventy‐two patients were included, with a median of two (1‐10) liver lesions, 53% bilobar involvement, and 7% extrahepatic disease. PreopCTX was applied for 3 months in median (1‐6). During restaging after a median of 62 days, presence of ETS was associated with improved median overall survival (OS; 57.1 vs 33.7 months; P = .010) and disease‐free survival (16 vs 7.2 months; P = .025). MC significantly correlated with major pathological response (P = .021). When combining ETS with optimal MC, presence of one or both factors was associated with pathological response (61.5% and 92.3%; P = .044) and OS in log‐rank (P = .011), and multivariable analysis (hazard ratio [HR] 0.41; 95% confidence interval [CI], 0.19‐0.90 and HR 0.32; 95%CI, 0.11‐0.97).ConclusionResponse‐grading by combined ETS/MC criteria less than 90 days after preopCTX initiation predicts pathological response and postoperative survival in CRLM.
Molecularly imprinted polymer functionalized magnetic Fe3O4 for the highly selective extraction of triclosan
Authors: Kong Xuan , Li Fei , Li Yijun , He Xiwen , Chen Langxing , Zhang Yukui 
Published: December 2019

AbstractWe present a facile strategy to prepare the molecularly imprinted polymers layer on the surface of Fe3O4 nanoparticles with core‐shell structure via sol–gel condensation for recognition and enrichment of triclosan. The Fe3O4 nanoparticles were first synthesized by a solvothermal method. Then, template triclosan was self‐assembled with the functional monomer 3‐aminopropyltriethoxysilane on the silica‐coated Fe3O4 nanoparticles in the presence of ethanol and water. Finally, the molecularly imprinted polymers were formed on the surface of silica‐coated Fe3O4 nanoparticles to obtain the product. The morphology, magnetic susceptibility, adsorption, and recognition property of magnetic molecularly imprinted polymers were characterized using transmission electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffractometry, vibrating sample magnetometry, and re‐binding experiments. The magnetic molecularly imprinted polymers showed binding sites with good accessibility, fast adsorption rate, and high adsorption capacity (218.34 μg/g) to triclosan. The selectivity of magnetic molecularly imprinted polymers was evaluated by the rebinding capability of triclosan and two other structural analogues (phenol and p‐chlorophenol) in a mixed solution and good selectivity with an imprinting factor of 2.46 was obtained. The application of triclosan removal in environmental samples was demonstrated.
Efficient separation of tocopherol homologues in vegetable oil by ionic‐liquid‐based countercurrent chromatography using a non‐aqueous biphasic system
Authors: Fan Chen , Li Nai , Cao Xueli 
Published: December 2019

AbstractTocopherol homologues are important fat‐soluble bioactive compounds with high nutritional value. However, it is of great challenge to separate these homologues because of their high structural similarities. In this work, ionic‐liquid‐based countercurrent chromatography was used for the separation and purification of tocopherol homologues. Conventional countercurrent chromatography and ionic‐liquid‐based countercurrent chromatography solvent systems were evaluated in respect of partition coefficient, separation factor, and stationary phase retention factor to separate these targets. Kind of ionic liquids, amount of ionic liquid, and sample amount were systematically optimized. A novel countercurrent chromatography non‐aqueous biphasic system composed of n‐hexane‐methanol‐1‐butyl‐3‐methylimidazolium chloride was established. The baseline separation of tocopherol mixtures was obtained in one cycle process. The ionic liquid played a key role in the countercurrent chromatography separation, which resulted in difference of partition behavior of individual tocopherol in the whole system through different hydrogen‐bonding affinity. Finally, n‐hexane‐methanol‐1‐butyl‐3‐methylimidazolium chloride (5:5:3, v/v) water‐free biphasic system was successfully applied to separate tocopherol homologues from vegetable oil that was not achieved beforehand. This method can be widely employed to separate many similar molecules such as tocotrienols, tocomonoenols, and marine‐derived tocopherol in food samples.
Fetal Nasal Bone Length in the East African Population
Authors: Burn Sabrina C. , Markese Amy , Bangdiwala Ananta , Gill Lisa , Jacobs Katherine 
Published: December 2019

ObjectivesTo establish normal ranges of fetal nasal bone length throughout gestation in the East African population and to subsequently compare these measurements with the standardized reference.MethodsA retrospective cross‐sectional study was performed at the University of Minnesota from January 2011 to December 2016. Fetal nasal bone length measurements were generated in a midsagittal plane at an angle of insonation of 45° from ultrasound images of 1407 nonanomalous fetuses of 1130 mothers of East African decent between 14 and 40 weeks’ gestation. The proportion of fetal nasal bone lengths of less than 5.2 mm at week 20 of gestation in the East African population was then compared with the 5% noted by the standardized reference by a χ2 test.ResultsThe fetal nasal bone length increased linearly with advancing gestational age in fetuses of East African mothers (R2 = 0.53; P < .0001). The fetal nasal bone lengths of the East African fetuses were found to be shorter at all ages of gestation compared with the standard reference. At 20 weeks’ gestation 17% (95% confidence interval, 13%–22%) of the nasal bone lengths of the East African fetuses were less than 5.2 mm compared with 5% of white and African American fetuses.ConclusionsUsing the standard reference may lead to a greater than 3.5‐fold overdiagnosis of hypoplastic nasal bones in the East African population. To improve aneuploidy risk stratification and patient counseling in the East African population, the introduction of a standardized East African–based fetal nasal bone length reference seems warranted.
Chronic Kidney Disease in Liver Transplant Candidates: A Rising Burden Impacting Post–Liver Transplant Outcomes
Authors: Cullaro Giuseppe , Verna Elizabeth C. , Lee Brian P. , Lai Jennifer C. 
Published: December 2019

The burden of chronic kidney disease (CKD) is rising among patients with cirrhosis, though it is not known what impact this has had on outcomes after liver transplantation (LT). All patients listed for LT in the United States between 2002 and 2017 were analyzed, excluding those listed with Model for End‐Stage Liver Disease (MELD) exceptions. The primary outcome was post‐LT mortality. We defined pre‐LT CKD as an estimated glomerular filtration rate <60 mL/minute for 90 days or ≥42 days of hemodialysis. Cox regression determined the association between pre‐LT CKD and post‐LT mortality. Of 78,640 LT candidates, the proportion with CKD among LT recipients increased from 7.8% in 2002 to 14.6% in 2017 (test for trend, P < 0.001). Among the 39,719 LT recipients, pre‐LT CKD was significantly associated with post‐LT mortality (hazard ratio [HR], 1.16; P < 0.001) even after adjusting for donor risk index (DRI), age, MELD, etiology, hepatic encephalopathy, simultaneous liver‐kidney transplantation (SLKT), and diabetes. There was no mediating influence of SLKT on the effect of pre‐LT CKD on post‐LT survival (P > 0.05). Therefore, pre‐LT CKD has a deleterious impact on post‐LT outcomes, which is an impact that is not mediated through SLKT. These findings highlight the need for the identification of CKD when preventative measures are possible.
Dynamic glucose‐enhanced (DGE) MRI in the human brain at 7 T with reduced motion‐induced artifacts based on quantitative R1ρ mapping
Authors: Boyd Philip S. , Breitling Johannes , Zimmermann Ferdinand , Korzowski Andreas , Zaiss Moritz , Schuenke Patrick , Weinfurtner Nina , Schlemmer Heinz‐Peter , Ladd Mark E. , Bachert Peter , Paech Daniel , Goerke Steffen 
Published: December 2019

PurposeDynamic glucose‐enhanced (DGE)‐MRI based on chemical exchange‐sensitive MRI, that is, glucoCEST and gluco‐chemical exchange‐sensitive spin‐lock (glucoCESL), is intrinsically prone to motion‐induced artifacts because the final DGE contrast relies on the difference of images, which were acquired with a time gap of several mins. In this study, identification of different types of motion‐induced artifacts led to the development of a 3D acquisition protocol for DGE examinations in the human brain at 7 T with improved robustness in the presence of subject motion.MethodsDGE‐MRI was realized by the chemical exchange‐sensitive spin‐lock approach based either on relaxation rate in the rotating frame (R1ρ)‐weighted or quantitative R1ρ imaging. A 3D image readout was implemented at 7 T, enabling retrospective volumetric coregistration of the image series and quantification of subject motion. An examination of a healthy volunteer without administration of glucose allowed for the identification of isolated motion‐induced artifacts.ResultsEven after coregistration, significant motion‐induced artifacts remained in the DGE contrast based on R1ρ‐weighted images. This is due to the spatially varying sensitivity of the coil and was found to be compensated by a quantitative R1ρ approach. The coregistered quantitative approach allowed the observation of a clear increase of the DGE contrast in a patient with glioblastoma, which did not correlate with subject motion.ConclusionThe presented 3D acquisition protocol enables DGE‐MRI examinations in the human brain with improved robustness against motion‐induced artifacts. Correction of motion‐induced artifacts is of high importance for DGE‐MRI in clinical studies where an unambiguous assignment of contrast changes due to an actual change in local glucose concentration is a prerequisite.