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To investigate the value of magnetic resonance imaging (MRI) signal intensity ratios (SIRs) based on fat-suppressed T2-weighted imaging (FS-T2WI), together with demographic features, MRI anatomical characteristics, and SIRs of histopathological patterns of the tumors, in the differentiation of parotid pleomorphic adenoma (PA) from Warthin tumor (WT). In total, 90 patients with PA and 56 patients with WT were enrolled in the study. SIRs of tumor to normal parotid gland (SIR-T/P), spinal cord (SIR-T/S), and muscle (SIR-T/M) were calculated. Demographic and radiological features of the 2-patient groups were compared with univariate analysis and multivariate logistic regression analysis. The area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were analyzed to evaluate the utility of SIRs in distinguishing between PA and WT. SIR-T/P exhibited outstanding discriminating ability (AUC = 0.934), SIR-T/S had excellent discrimination (AUC = 0.839), and SIR-T/M showed acceptable discrimination (AUC = 0.728). When SIR-T/P of 1.96 was selected as the cutoff value, sensitivity and specificity were 0.756 and 0.982, respectively. SIR-T/P, age, sex, and number of lesions were identified as independent predictors by multivariate logistic regression analysis. Differences in SIRs between histopathological patterns were significant. SIR-T/P based on FS-T2WI is an effective discriminator in the differential diagnosis between PA and WT. Age, sex, and number of lesions provided additional value in differentiation. [ABSTRACT FROM AUTHOR]

Abstract: Oligonucleotides containing 7-bromo-7-deaza-2,8-diaza-2′-deoxyadenosine ( 3 ) and 5-amino-3-bromo-4-carbamoyl-1-(2′-deoxy-β-d-erythro-pentofuranosyl)pyrazole ( 4 ) were synthesized. Compound 3 was prepared from 7-bromo-8-aza-7-deaza-2′-deoxyadenosine ( 5 ) via the 1,N 6-etheno derivative 6 and was converted into the phosphoramidite 11 . The 7-bromo substituent of 3 increases oligonucleotide duplex stability compared to the non-halogenated nucleoside. Oligonucleotides incorporating 3 are transformed to those containing 4 during long time deprotection at elevated temperature (25% aq ammonia, 60°C, 30h). Compound 3 forms a strong base pair with dG. The base pair stability decreases in the order dG>dT>dA>dC. Similar recognition selectivity is observed for the pyrazole nucleoside 4 , however, due to decreased stacking and higher flexibility of the pyrazole moiety, duplexes are less stable than those containing 3 . [Copyright &y& Elsevier]

A series of chiral oxazolines, which had been conveniently prepared from commercially available (1S,2S)-2-amino-1-phenylpropane-1,3-diol, was applied in the diethylzinc addition to diphenylphosphinoyl imines to give high yields of 68–84% and excellent e.e. values of 90–93%. [Copyright &y& Elsevier]

• A terahertz compressed sensing imaging method based on line array detection is proposed. • In the experiment, the reconstruction of the letter sample is realized at a sampling rate of 16%. • The proposed technology is used to reconstruct the imaging images of the terahertz line scan system. In this paper, a terahertz compressed sensing imaging technique based on line array detection is proposed. The feasibility of the proposed terahertz compressed sensing imaging based on line array detection is verified by theoretical derivation, MATLAB and ZEMAX simulation as well as practical experiment. Firstly, we compare the traditional single-pixel compressed sensing imaging, block compressed sensing imaging and the proposed terahertz compressed sensing imaging based on line array detection by MATLAB simulation, and the results show that the proposed technique can achieve high-quality image reconstruction. Then, we import self-designed mask and lenses as well as other devices into ZEMAX to simulate the compressive sensing process of line array detection using non-sequential mode. According to the simulation results, a terahertz line array compressive sensing imaging system is built using a high-speed line-array detector. The experimental results show that the technique has higher imaging stability and the sampling process is highly generalizable to different objects. Compared with the traditional single-pixel random sampling compressed sensing method, this method greatly reduces the sampling rate and successfully reconstructs the original image at a sampling rate of 16%. We believe that the compressed sensing terahertz imaging technology based on line array detection proposed in this paper provides a new idea for terahertz multi-pixel compressed sensing imaging, which is expected to promote the development of terahertz high-resolution rapid imaging. In addition, this technology can be applied to both terahertz line and area scan imaging systems, which has great application potential in correcting image distortion caused by movement of imaging objects. [ABSTRACT FROM AUTHOR]

We report on an alternative modified TiO 2 -based photoanode for obtaining enhanced photovoltaic (PV) properties in DSSCs. Multiferroics BiFeO 3 was employed to construct BiFeO 3 +TiO 2 composite photoanode for DSSCs. Here, BiFeO 3 may also act as photoelectric conversion medium and increases photogenerated carrier transport channels, consequently, improves the PCE of DSSCs with BiFeO 3 +TiO 2 composite photoanodes. More importantly, magnetic-field enhanced PV properties in abovementioned DSSCs was firstly obtained. The investigated results offer both an alternative method to improve PV properties in DSSCs, and a referential train of thought to manipulate photoelectric properties of solar cells. [Display omitted] • Multiferroics BiFeO 3 , which presents magnetic, electric, and visible light catalytic properties, was firstly introduced to act as part of photoanode in the investigation of DSSCs. • Enhancement of photoelectric conversion efficiency in DSSC devices with BiFeO 3 + TiO 2 composite photoanodes has been obtained , indicating an alternative approach for enhancing photoelectric conversion efficiency of solar cells is achieved. Also, suggesting a promising potential in the application of photoelectric conversion. • External magnetic field enhancing photoelectric conversion performance was observed firstly in DSSC devices with BiFeO 3 + TiO 2 composite photoanodes. • Providing a universal way that can be available in photovoltaic cell field by non-contact external magnetic field modulation method. In dye-sensitized solar cells (DSSCs), the light absorbance of photoanode is the most important factor in power conversion efficiency (PCE). Here the authors report on an alternative modified TiO 2 -based photoanode for obtaining enhanced photovoltaic (PV) properties in DSSCs. Multiferroics BiFeO 3 , which possesses excellent magnetic, electric, and photocatalytic performances, was employed to construct BiFeO 3 + TiO 2 composite photoanode for DSSCs. In this type of DSSCs with BiFeO 3 + TiO 2 composite photoanodes, BiFeO 3 with suitable bandgap may also act as photoelectric conversion medium, which is generally acted by dye in DSSCs, and increases photogenerated carrier transport channels, which improves the PCE of DSSCs with BiFeO 3 + TiO 2 composite photoanodes. More importantly, magnetic-field enhanced PV properties in abovementioned DSSCs was firstly obtained, which may result from magnetic-field-suppression the recombination of charge carriers and magnetoresistance effect in BiFeO 3. The investigated results offer both an alternative method to improve PV properties in DSSCs, and a referential train of thought to manipulate photoelectric properties of solar cells. [ABSTRACT FROM AUTHOR]

Abstract: Two sets of novel chiral oxazoline ligands were designed and conveniently prepared from readily available l-aspartic acid and evaluated in enantioselective diethylzinc addition to N-diphenylphosphinoyl imines. In the presence of stoichiometric amounts of these ligands, high enantioselectivities (up to 95% ee) and yields (up to 85%) were achieved for several aromatic imines in toluene at room temperature. Furthermore, the effect of the structure of the ligand on the reaction was studied. [Copyright &y& Elsevier]

Abstract: Enantioselective hydrosilylation of N-aryl and N-benzyl ketimines with trichlorosilane catalyzed by readily accessible chiral N-picolinoylaminoalcohols proceeded smoothly furnishing chiral secondary amines in good yields (up to 93%) and moderate to excellent enantioselectivities (up to 95% ee). [Copyright &y& Elsevier]

• Aspheric lens for large depth-of-field terahertz imaging at long distances. • Depth-of-field extension is achieved by incident light with a wide field-of-view. • Farther from the element than the Bessel beam depth-of-field start point. • Fast imaging of large targets can be achieved with multipixel terahertz detectors. Terahertz (THz) imaging can serve as a versatile instrument to disclose contents of various packages or items hidden under clothing. When imaging a large target with a certain thickness at a long distance, the requirements for the imaging speed and imaging quality of the system are particularly worthy of attention. To tackle these problems and extend an assortment of application, this paper proposes a wide field-of-view (FOV) aspheric lens suitable for rapid imaging systems for extending the depth-of-field (DOF) of THz imaging at long distances. The designed aspherical lens with a diameter of 264 mm – made of high-density polyethylene (HDPE) and manufactured by machining – allows extending the DOF up to 85 mm by separately focusing incident light with different FOV angles, which not only allows fast THz imaging combined with linear array detector but also refuses the use of complicated imaging optical paths. A reflective one-dimensional (1D) scanning imaging system with a 0.1 THz source reveals that the lens can simultaneously achieve wavelength-level resolution and a DOF range of 85 mm for objects at a distance greater than 415 mm from the lens surface in a wide-field illumination system, in which the contrast of the obtained results can reach more than 15%. The observed results justify the application value of the lens in long-distance, wide-field THz imaging systems. [ABSTRACT FROM AUTHOR]

• A modified isotope-based method was developed to estimate the evapotranspiration partitioning, and it can be applied on various time scales. • The modified method and the traditional method are equivalent at a 15-minute time scale. • The modified method is capable of partitioning evapotranspiration at high-frequency and distributed the high sensitivity parameter δ ET into other three less sensitive parameters. • The high-frequency method is advantageous in avoiding the extrapolation of the keeling plot regression line, and enabling the calculation of confidence interval of evapotranspiration partition. • The high-frequency method might be useful when investigating evapotranspiration partitioning under short-term extreme weather events and flush agricultural irrigation. To better understand water and energy cycles, numerous efforts to partition evapotranspiration (ET) into evaporation (E) and transpiration (T) have been made over the recent half century. One of the analytical methods is the isotopic approach. The isotopic composition of ET (δ ET) is a crucial parameter in the traditional isotope-based ET partitioning model, which however, has considerable uncertainty and high sensitivity. Here we proposed a modified T fraction in total ET (F T) calculation using Keeling plot slope (k), the atmospheric vapor concentration (C v), and the isotopic composition of atmospheric vapor (δ v), to avoid the direct use of δ ET. Following the traditional method, we used the Craig-Gordon model for the isotopic composition of evaporation (δ E) and chamber method for the isotopic composition of transpiration (δ T) in our modified method. The modified F T calculation method (F T (m)) can be applied at a 15-min time scale using the average values (F Ti (mp)) and at a 1 Hz time scale for high-frequency method (F Ti). The modified method was verified by both theoretical derivations and field observations. F Ti (mp) was equivalent to those using the traditional isotopic method at a 15-min time scale. However, F Ti eliminated the highly sensitive parameter δ ET , and redistributed the sensitivity of δ ET into three less sensitive parameters. Additionally, F Ti has two main advantages. First, the high-frequency method avoids the extrapolation of the Keeling plot regression line intercept. Second, the high-frequency method can produce a 95% confidence interval of F T in a measurement cycle (e.g., 15 min). The calculated confidence interval was different from that of traditional uncertainty analysis. The high-frequency method might be useful when investigating evapotranspiration partitioning under short-term extreme weather events and flush agricultural irrigation. [ABSTRACT FROM AUTHOR]

Abstract: Ethyl (R)-2-hydroxy-4-phenylbutyrate ((R)-HPBE), a key intermediate in the production of angiotensin-converting enzyme (ACE) inhibitors, was prepared by the microbial reduction of ethyl 2-oxo-4-phenylbutyrate (OPBE). Among 63 microorganisms tested, Candida krusei SW2026, for the first time, was proven to be a highly effective biocatalyst in this reduction process, leading to the (R)-enantiomer in 99.7% ee and 95.1% yield at 2.5g/L of OPBE (under optimal conditions of 30°C, pH 6.6, and in the presence of 5% glucose as co-substrate). In order to achieve higher product concentration with desired enantiopurity and yield for application in large-scale production, strategies such as substrate fed-batch and aqueous/organic biphasic system were successfully conducted in the biotransformation reaction. At 20g/L of OPBE, the enantiomeric excess (ee), yield, and product concentration were enhanced to 97.4%, 82.0%, and 16.6g/L, respectively, in water/dibutyl phthalate biphasic system, compared with 87.5%, 45.8%, and 9.2g/L in aqueous medium. This study provides an attractive process of (R)-HPBE production for potential green chemistry applications. [Copyright &y& Elsevier]