Study on Load Model of PV Generation Planning

AbstractIn distribution system planning with photovoltaic generations (PVGs), if load is not properly modeled in the simulation, the accuracy of results will be affected. A large number of studies show that load characteristics play a impotrant role in the system analysis. This paper presented the resultant load model, and on this basis, studied the impacts of the constant power load model and constant impedance load model on PV generation planning. Simulation results show that the selection of load models has an important impact on PV generation planning

Stability studies of ZnO and AlN thin film acoustic wave devices in acid and alkali harsh environments

Surface acoustic wave (SAW) devices based on piezoelectric thin-films such as ZnO and AlN are widely used in sensing, microfluidics and lab-on-a-chip applications. However, for many of these applications, the SAW devices will inevitably be used in acid or alkali harsh environments, which may cause their early failures. In this work, we investigated the behavior and degradation mechanisms of thin film based SAW devices in acid and alkali harsh environments. Results show that under the acid and alkali attacks, chemical reaction and corrosion of ZnO devices are very fast (usually within 45 s). During the corrosion, the crystalline orientation of the ZnO film is not changed, but its grain defects are significantly increased and the grain sizes are decreased. The velocity of ZnO-based SAW devices is decreased due to the formation of porous structures induced by the chemical reactions. Whereas an AlN thin-film based SAW device does not perform well in acid–alkali conditions, it might be able to maintain a normal performance without obvious degradation for more than ten hours in acid or alkali solutions. This work could provide guidance for the applications of both ZnO or AlN-based SAW devices in acid/alkali harsh environments

Selective Adsorption and Separation of (−)-Epigallocatechin Gallate (EGCG) based on Silica Gel Surface Molecularly Imprinted Polymers

AbstractTo separate and enrich EGCG from a mixture of tea catechins, the molecular imprinted polymers (MIPs) were synthesized on silica gel by surface molecular imprinting technique and characterized with Fourier transform infrared spectroscopy (FT-IR), elemental analysis and scanning electronic microscopy (SEM). MIPs exhibited favorable recognition, better selectivity for EGCG than the other monomers, and the descending order was EGCG, (+)-catechin (C), (−)-epicatechin (EC), (−)-epigallocatechin (EGC), (−)-catechin gallate (CG) and (−)-gallocatechin gallate (GCG). These results demonstrated that MIPs could realize the separation and enrichment of EGCG in real sample

1-(2-Hy­droxy-3,5-dimeth­oxy­phen­yl)ethanone

In title compound, C10H12O4, all of the non-H atoms lie approximately in a plane with the largest deviation being 0.061 (2) Å. An intra­molecular O—H⋯O hydrogen bond generates an S(6) ring motif. No classical inter­molecular hydrogen bonding occurs, with only van der Waals forces stabilizing the crystal structure

Studies on the therapeutic effects of three TCM methods on steroid-induced osteonecrosis of femoral head

Purpose: To determine the therapeutic effects of kidney yang-tonifying, blood-activating and phlegmeliminating methods on steroid-induced osteonecrosis of femoral head (SONFH), and their mechanisms of action.Methods: A rabbit model of SONFH was established. Six rabbit groups were used: control, SONFH (given normal saline); tongluo shenggu group, kidney-tonifying group, blood-activating group, and phlegm--eliminating group, which received tongluo shenggu capsule (0.28 g/kg/day), yougui yin (YGY, 2.52 g/kg/day), taohong siwu decoction (TSD, 2.38 g/kg/day) and linggui zhugan decoction (LZD,1.54 g/kg/day), respectively, for 8 weeks. The following serum indices were assayed on the 2nd, 4th and 8th weeks: total cholesterol, triglycerides, thromboxane B2 (TXB2), 6-keto-PGF1α, osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-Β ligand (RANKL). At the end of the 8th week, mRNA levels of OPG, BMP-2 and VEGF were assayed using real-time fluorescent quantitative polymerase chain reaction (RTF-qPCR).Results: Serum OPG in the kidney-tonifying group was increased, while its RANKL was decreased on the 2nd week, but these parameters, along with mRNA of OPG and BMP-2, reached normal levels at the 8th week (p <0.05). The TXB2 of blood-activating group was decreased, while its 6-keto-PGF1 level was increased at the 2nd week, but both of them attained normal levels at the 8th week, along with VEGF mRNA. Serum total cholesterol, triglycerides and TXB2 in the phlegm-eliminating group were decreased, while its 6-keto-PGF1α was increased at the 2nd week, but the levels of serum total cholesterol and triglycerides were normalized at the 8th week (p <0.05). Histological examination showed increases in bone trabeculae and bone marrow cells, while the proliferation of fat cells was decreased in kidney-tonifying, blood-activating and phlegm-eliminating groups.Conclusion: These findings suggest that the therapeutic effects of the three different TCM methods on SONFH involve different mechanisms. Keywords: Steroid-induced osteonecrosis, Femoral head, Yougui yin, Taohong siwu, Linggui zhugan decoction, Kidney-tonifying yang, Phleg

Delineating the biosynthesis of gentamicin x2, the common precursor of the gentamicin C antibiotic complex.

Gentamicin C complex is a mixture of aminoglycoside antibiotics used worldwide to treat severe Gram-negative bacterial infections. Despite its clinical importance, the enzymology of its biosynthetic pathway has remained obscure. We report here insights into the four enzyme-catalyzed steps that lead from the first-formed pseudotrisaccharide gentamicin A2 to gentamicin X2, the last common intermediate for all components of the C complex. We have used both targeted mutations of individual genes and reconstitution of portions of the pathway in vitro to show that the secondary alcohol function at C-3″ of A2 is first converted to an amine, catalyzed by the tandem operation of oxidoreductase GenD2 and transaminase GenS2. The amine is then specifically methylated by the S-adenosyl-l-methionine (SAM)-dependent N-methyltransferase GenN to form gentamicin A. Finally, C-methylation at C-4″ to form gentamicin X2 is catalyzed by the radical SAM-dependent and cobalamin-dependent enzyme GenD1.This work was supported by a project grant from the Medical Research Council, UK (G1001687) to P.F.L.; and by the 973 and 863 programs from the Ministry of Science and Technology of China, National Science Foundation of China, and the Translational Medical Research Fund of Wuhan University School of Medicine to Y.S.; E.M. thanks the Gates Cambridge Trust for a scholarship. We also gratefully acknowledge Dr. Xinzhou Yang, SouthCentral University for Nationalities, for his assistance in separation of gentamicin A2. We thank Dr. Andrew Truman (John Innes Institute) for helpful discussions.This is the final published version. It was originally published in Chemistry and Biology, Volume 22, Issue 2, 19 February 2015, Pages 251–261, doi:10.1016/j.chembiol.2014.12.01

Elevated level of anterior gradient-2 in pancreatic juice from patients with pre-malignant pancreatic neoplasia

<p>Abstract</p> <p>Background</p> <p>Pancreatic intraepithelial neoplasias (PanINs) are precursors of malignant pancreatic cancer, an ideal stage for early cancer detection. We applied quantitative proteomics to identify aberrantly elevated proteins in pancreatic juice samples derived from patients with PanIN3.</p> <p>Results</p> <p>Twenty proteins were found elevated in all three PanIN juices by at least two-fold. Among these proteins, anterior gradient-2 (AGR2) was found to be 2-10 fold elevated in PanIN3 juice samples analyzed by quantitative proteomics. An ELISA assay was developed to evaluate AGR2 levels in 51 pancreatic juice samples and 23 serum samples from patients with pancreatic cancer, pre-malignant lesions (including PanIN3, PanIN2, Intraductal Papillary Mucinous Neoplasms (IPMNs)) and benign disease controls (including chronic pancreatitis). AGR2 levels in the pancreatic juice samples were found significantly elevated in patients with pre-malignant conditions (PanINs and IPMNs) as well as pancreatic cancer compared to control samples (p ≤ 0.03). By ROC analysis, the AGR2 ELISA achieved 67% sensitivity at 90% specificity in predicting PanIN3 juice samples from the benign disease controls.</p> <p>Conclusions</p> <p>These results suggest that elevation of AGR2 levels in pancreatic juice occurs in early pancreatic cancer progression and could be further investigated as a potential candidate juice biomarker for early detection of pancreatic cancer.</p

Evaluation of the Ribosomal Protein S1 Gene (rpsA) as a Novel Biomarker for Mycobacterium Species Identification

Objectives. To evaluate the resolution and reliability of the rpsA gene, encoding ribosomal protein S1, as a novel biomarker for mycobacteria species identification. Methods. A segment of the rpsA gene (565 bp) was amplified by PCR from 42 mycobacterial reference strains, 172 nontuberculosis mycobacteria clinical isolates, and 16 M. tuberculosis complex clinical isolates. The PCR products were sequenced and aligned by using the multiple alignment algorithm in the MegAlign package (DNASTAR) and the MEGA program. A phylogenetic tree was constructed by the neighbor-joining method. Results. Comparative sequence analysis of the rpsA gene provided the basis for species differentiation within the genus Mycobacterium. Slow-and rapid-growing groups of mycobacteria were clearly separated, and each mycobacterial species was differentiated as a distinct entity in the phylogenetic tree. The sequences discrepancy was obvious between M. kansasii and M. gastri, M. chelonae and M. abscessus, M. avium and M. intracellulare, and M. szulgai and M. malmoense, which cannot be achieved by 16S ribosomal DNA (rDNA) homologue genes comparison. 183 of the 188 (97.3%) clinical isolates, consisting of 8 mycobacterial species, were identified correctly by rpsA gene blast. Conclusions. Our study indicates that rpsA sequencing can be used effectively for mycobacteria species identification as a supplement to 16S rDNA sequence analysis

Space-time crystals of trapped ions

Spontaneous symmetry breaking can lead to the formation of time crystals, as well as spatial crystals. Here we propose a space-time crystal of trapped ions and a method to realize it experimentally by confining ions in a ring-shaped trapping potential with a static magnetic field. The ions spontaneously form a spatial ring crystal due to Coulomb repulsion. This ion crystal can rotate persistently at the lowest quantum energy state in magnetic fields with fractional fluxes. The persistent rotation of trapped ions produces the temporal order, leading to the formation of a space-time crystal. We show that these space-time crystals are robust for direct experimental observation. We also study the effects of finite temperatures on the persistent rotation. The proposed space-time crystals of trapped ions provide a new dimension for exploring many-body physics and emerging properties of matter.Comment: updated to the version published in PR

A potential relationship between MMP-9 rs2250889 and ischemic stroke susceptibility

PurposeIschemic stroke (IS), a serious cerebrovascular disease, greatly affects people's health and life. Genetic factors are indispensable for the occurrence of IS. As a biomarker for IS, the MMP-9 gene is widely involved in the pathophysiological process of IS. This study attempts to find out the relationship between MMP-9 polymorphisms and IS susceptibility.MethodsA total of 700 IS patients and 700 healthy controls were recruited. The single nucleotide polymorphism (SNP) markers of the MMP-9 gene were genotyped by the MassARRAY analyzer. Multifactor dimensionality reduction (MDR) was applied to generate SNP–SNP interaction. Furthermore, the relationship between genetic variations (allele and genotype) of the MMP-9 gene and IS susceptibility was analyzed by calculating odds ratios (ORs) and 95% confidence intervals (CIs).ResultsOur results demonstrated that rs2250889 could significantly increase the susceptibility to IS in the codominant, dominant, overdominant, and log-additive models (p &lt; 0.05). Further stratification analysis showed that compared with the control group, rs2250889 was associated with IS risk in different case groups (age, female, smoking, and non-drinking) (p &lt; 0.05). Based on MDR analysis, rs2250889 was the best model for predicting IS risk (cross-validation consistency: 10/10, OR = 1.56 (1.26–1.94), p &lt; 0.001).ConclusionOur study preliminarily confirmed that SNP rs2250889 was significantly associated with susceptibility to IS