383 research outputs found
Bis(2,6-dihydroxybenzoato-κ2 O 1,O 1′)(nitrato-κ2 O,O′)bis(1,10-phenanthroline-κ2 N,N′)neodymium(III)
In the mononuclear title complex, [Nd(C7H5O4)2(NO3)(C12H8N2)2], the NdIII atom is in a distorted bicapped square-antiprismatic geometry formed by four N atoms from two chelating 1,10-phenanthroline (phen) ligands, four O atoms from two 2,6-dihydroxybenzoate (DHB) ligands and two O atoms from a nitrate anion. π–π stacking interactions between the phen and DHB ligands of adjacent complexes [centroid–centroid distances = 3.520 (6) and 3.798 (6) Å] stabilize the crystal structure. Intramolecular O—H⋯O hydrogen bonds are observed in the DHB ligands
A Non-Intrusive Pressure Sensor by Detecting Multiple Longitudinal Waves
Pressure vessels are widely used in industrial fields, and some of them are safety-critical components in the system - for example, those which contain flammable or explosive material. Therefore, the pressure of these vessels becomes one of the critical measurements for operational management. In the paper, we introduce a new approach to the design of non-intrusive pressure sensors, based on ultrasonic waves. The model of this sensor is built based upon the travel-time change of the critically refracted longitudinal wave (LCR wave) and the reflected longitudinal waves with the pressure. To evaluate the model, experiments are carried out to compare the proposed model with other existing models. The results show that the proposed model can improve the accuracy compared to models based on a single wave
Pressure measurement based on multi-waves fusion algorithm
Measuring the pressure of a pressure vessel accurately is one of fundamental requirements of the operation of many complex engineering systems. Ultrasonic technique has been proposed to be a good alteration of non-intrusive measurement. Based on the study of acoustoelastic effect and thin-shell theory, it has been identified that the travel-time changes of the critically refracted longitudinal wave (LCR wave) and other reflected longitudinal waves are all proportional to the inner pressure. Considering the information redundancy in these waves, we proposed an approach for pressure measurement by using the information fusion algorithm on multiple reflected longitudinal waves. In the paper, we discussed the fusion algorithm in details and proposed a pressure measurement model, which represents an accurate relationship between the pressure and the travel-time changes of multiple waves. Through the experiment, the analysis of data collected from experiment system showed that the pressure measurement based on the multi-wave model is notably more accurate than the one based on the single-wave model (the average relative error (ARE) can be less than 7.24% and the root-mean-square error (RMSE) can be lower than 0.3MPa)
Bis(2,6-dihydroxybenzoato-κ2 O 1 ,O 1′)(nitrato-κ2 O,O′)bis(1,10-phenanthroline-κ2 N,N′)gadolinium(III)
In the mononuclear title complex, [Gd(C7H5O3)2(NO3)(C12H8N2)2], the Gd atom is in a pseudo-bicapped square-antiprismatic geometry formed by four N atoms from two chelating 1,10-phenanthroline (phen) ligands and by six O atoms, four from two 2,6-dihydroxybenzoate (DHB) ligands and the other two from a nitrate anion. π–π stacking interactions between phen–DHB [centroid–centroid distances = 3.5334 (18) and 3.8414 (16) Å] and phen–phen [face-to-face separation = 3.4307 (17) Å] ligands of adjacent complex molecules stabilize the crystal structure. Intramolecular O—H⋯O hydrogen bonds are observed in the DHB ligands
The Rice Diacylglycerol Kinase Family: Functional Analysis Using Transient RNA Interference
Diacylglycerol kinase (DGK) is a pivotal enzyme that phosphorylates diacylglycerol (DAG) to form phosphatidic acid (PA). The production of PA from phospholipase D (PLD) and the coupled phospholipase C/DGK route is an important signaling process in animal and plant cells. In this study, we report a genomic analysis of eight putative rice DGKs encoded by a gene family (OsDGKs) grouped into three clusters. To further investigate the functions of the OsDGKs, a double-stranded RNA (dsRNA)-induced RNA silencing method was established. Introduction of in vitro-synthesized dsRNAs corresponding to a unique or conserved region of OsDGKs into rice protoplasts abolished or diminished the expression of individual or multiple OsDGK genes. Suppressing the expression of OsDGKs resulted in a distinct depletion of the transcripts of the defense gene OsNPR1 and the salt-responsive gene OsCIPK15. Our primary results suggest that OsDGKs are involved in the signaling of stress responses
Genetic variants in ELOVL2 and HSD17B12 predict melanoma‐specific survival
Fatty acids play a key role in cellular bioenergetics, membrane biosynthesis and intracellular signaling processes and thus may be involved in cancer development and progression. In the present study, we comprehensively assessed associations of 14,522 common single‐nucleotide polymorphisms (SNPs) in 149 genes of the fatty‐acid synthesis pathway with cutaneous melanoma disease‐specific survival (CMSS). The dataset of 858 cutaneous melanoma (CM) patients from a published genome‐wide association study (GWAS) by The University of Texas M.D. Anderson Cancer Center was used as the discovery dataset, and the identified significant SNPs were validated by a dataset of 409 CM patients from another GWAS from the Nurses’ Health and Health Professionals Follow‐up Studies. We found 40 noteworthy SNPs to be associated with CMSS in both discovery and validation datasets after multiple comparison correction by the false positive report probability method, because more than 85% of the SNPs were imputed. By performing functional prediction, linkage disequilibrium analysis, and stepwise Cox regression selection, we identified two independent SNPs of ELOVL2 rs3734398 T>C and HSD17B12 rs11037684 A>G that predicted CMSS, with an allelic hazards ratio of 0.66 (95% confidence interval = 0.51–0.84 and p = 8.34 × 10−4) and 2.29 (1.55–3.39 and p = 3.61 × 10−5), respectively. Finally, the ELOVL2 rs3734398 variant CC genotype was found to be associated with a significantly increased mRNA expression level. These SNPs may be potential markers for CM prognosis, if validated by additional larger and mechanistic studies
Modeling biogenic and anthropogenic secondary organic aerosol in China
A revised Community Multi-scale Air Quality (CMAQ) model with updated
secondary organic aerosol (SOA) yields and a more detailed description of SOA
formation from isoprene oxidation was applied to study the spatial and
temporal distribution of SOA in China in the entire year of 2013. Predicted
organic carbon (OC), elemental carbon and volatile organic compounds agreed
favorably with observations at several urban areas, although the high OC
concentrations in wintertime in Beijing were under-predicted. Predicted
summer SOA was generally higher (10–15 µg m<sup>−3</sup>) due to large
contributions of isoprene (country average, 61 %), although the relative
importance varies in different regions. Winter SOA was slightly lower and was
mostly due to emissions of alkane and aromatic compounds (51 %).
Contributions of monoterpene SOA was relatively constant (8–10 %).
Overall, biogenic SOA accounted for approximately 75 % of total SOA in
summer, 50–60 % in autumn and spring, and 24 % in winter. The
Sichuan Basin had the highest predicted SOA concentrations in the country in
all seasons, with hourly concentrations up to 50 µg m<sup>−3</sup>.
Approximately half of the SOA in all seasons was due to the traditional
equilibrium partitioning of semivolatile components followed by
oligomerization, while the remaining SOA was mainly due to reactive surface
uptake of isoprene epoxide (5–14 %), glyoxal (14–25 %) and
methylglyoxal (23–28 %). Sensitivity analyses showed that formation of
SOA from biogenic emissions was significantly enhanced due to anthropogenic
emissions. Removing all anthropogenic emissions while keeping the biogenic
emissions unchanged led to total SOA concentrations of less than
1 µg m<sup>−3</sup>, which suggests that manmade emissions facilitated
biogenic SOA formation and controlling anthropogenic emissions would result
in reduction of both anthropogenic and biogenic SOA
Genetic variants in TKT and DERA in the NADPH pathway predict melanoma survival
Background: Cutaneous melanoma (CM) is the most lethal type of skin cancers. Nicotinamide adenine dinucleotide phosphate (NADPH) plays an important role in anabolic reactions and tumorigenesis, but many genes are involved in the NADPH system.
Methods: We used 10,912 single-nucleotide polymorphisms (SNPs) (2018 genotyped and 8894 imputed) in 134 NADPH-related genes from a genome-wide association study (GWAS) of 858 patients from The University of Texas MD Anderson Cancer Center (MDACC) in a single-locus analysis to predict CM survival. We then replicated the results in another GWAS data set of 409 patients from the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS).
Results: There were 95 of 858 (11.1%) and 48 of 409 (11.7%) patients who died of CM, respectively. In multivariable Cox regression analyses, we identified two independent SNPs (TKT rs9864057 G > A and deoxyribose phosphate aldolase (DERA) rs12297652 A > G) to be significantly associated with CM-specific survival [hazards ratio (HR) of 1.52, 95% confidence interval (CI) = 1.18-1.96, P = 1.06 × 10-3 and 1.51 (1.19-1.91, 5.89 × 10-4)] in the meta-analysis, respectively. Furthermore, an increasing number of risk genotypes of these two SNPs was associated with a higher risk of death in the MDACC, the NHS/HPFS, and their combined data sets (Ptrend A and DERA rs12297652 A > G were also significantly associated with higher mRNA expression levels in sun-exposed lower-leg skin (P = 0.043 and 0.006, respectively).
Conclusions: These results suggest that these two potentially functional SNPs may be valuable prognostic biomarkers for CM survival, but larger studies are needed to validate these findings
Multipath ultrasonic gas flow-meter based on multiple reference waves
Several technologies can be used in ultrasonic gas flow-meters, such as transit-time, Doppler, cross-correlation and etc. In applications, the approach based on measuring transit-time has demonstrated its advantages and become more popular. Among those techniques which can be applied to determine time-of-flight (TOF) of ultrasonic waves, including threshold detection, cross correlation algorithm and other digital signal processing algorithms, cross correlation algorithm has more advantages when the received ultrasonic signal is severely disturbed by the noise. However, the reference wave for cross correlation computation has great influence on the precise measurement of TOF. In the applications of the multipath flow-meters, selection of the reference wave becomes even more complicated. Based on the analysis of the impact factors that will introduce noise and waveform distortion of ultrasonic waves, an averaging method is proposed to determine the reference wave in this paper. In the multipath ultrasonic gas flow-meter, the analysis of each path of ultrasound needs its own reference wave. In case study, a six-path ultrasonic gas flow-meter has been designed and tested with air flow through the pipeline. The results demonstrate that the flow rate accuracy and the repeatability of the TOF are significantly improved by using averaging reference wave, compared with that using random reference wave
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