Klobuchar, NeQuickG, BDGIM, GLONASS, IRI-2016, IRI-2012, IRI-Plas, NeQuick2, and GEMTEC Ionospheric Models: A Comparison in Total Electron Content and Positioning Domains.

Global navigation satellite systems (GNSS) provide a great data source about the ionosphere state. These data can be used for testing ionosphere models. We studied the performance of nine ionospheric models (Klobuchar, NeQuickG, BDGIM, GLONASS, IRI-2016, IRI-2012, IRI-Plas, NeQuick2, and GEMTEC) both in the total electron content (TEC) domain-i.e., how precise the models calculate TEC-and in the positioning error domain-i.e., how the models improve single frequency positioning. The whole data set covers 20 years (2000-2020) from 13 GNSS stations, but the main analysis involves data during 2014-2020 when calculations are available from all the models. We used single-frequency positioning without ionospheric correction and with correction via global ionospheric maps (IGSG) data as expected limits for errors. Improvements against noncorrected solution were as follows: GIM IGSG-22.0%, BDGIM-15.3%, NeQuick2-13.8%, GEMTEC, NeQuickG and IRI-2016-13.3%, Klobuchar-13.2%, IRI-2012-11.6%, IRI-Plas-8.0%, GLONASS-7.3%. TEC bias and mean absolute TEC errors for the models are as follows: GEMTEC--0.3 and 2.4 TECU, BDGIM--0.7 and 2.9 TECU, NeQuick2--1.2 and 3.5 TECU, IRI-2012--1.5 and 3.2 TECU, NeQuickG--1.5 and 3.5 TECU, IRI-2016--1.8 and 3.2 TECU, Klobuchar-1.2 and 4.9 TECU, GLONASS--1.9 and 4.8 TECU, and IRI-Plas-3.1 and 4.2 TECU. While TEC and positioning domains differ, new-generation operational models (BDGIM and NeQuickG) could overperform or at least be at the same level as classical empirical models.

Impact of renal insufficiency on patients with hepatocellular carcinoma undergoing radiofrequency ablation.

BACKGROUND AND AIM: Renal insufficiency (RI) is commonly seen in patients with hepatocellular carcinoma (HCC). We aimed to investigate the impact of RI on the long-term survival of HCC patients undergoing radiofrequency ablation (RFA) and to determine the optimal staging strategy for these patients. METHODS: RI was defined as an estimated glomerular filtration rate < 60 mL/min/1.73 m(2) . A total of 123 and 344 patients with and without RI undergoing RFA, respectively, were enrolled. A one-to-one propensity score matching analysis with preset caliper width was performed. The prognostic ability of four currently used staging systems was compared by the Akaike information criterion (AIC). RESULTS: HCC patients with RI undergoing RFA were older (P < 0.001) and had significantly different baseline characteristics. Of all patients, RI was significantly associated with a decreased long-term survival (P = 0.03). After matching in the propensity model, the baseline characteristics were similar between patients with (n = 92) and without (n = 92) RI. In the propensity model, RI was not significantly associated with a shortened survival (P = 0.273). In the Cox multivariate analysis, Child-Turcotte-Pugh class B or C was identified as the only independent predictor of poor prognosis. Among patients with RI undergoing RFA, the Taipei Integrated Scoring (TIS) system provided the highest homogeneity and lowest AIC value among the currently used staging systems. CONCLUSIONS: The long-term survival of HCC patients undergoing RFA is not affected by RI. The TIS staging system may provide a better prognostic prediction for HCC patients with RI undergoing RFA.

Inflammation-associated D-dimer predicts neurological outcome of recent small subcortical infarct: A prospective clinical and laboratory study.

OBJECTIVE: Elevated level of D-Dimer often indicates a worse prognosis in cerebral infarction. However, there is limited research on this impact within recent small subcortical infarction (RSSI). We aim to explore the role of inflammation and the total magnetic resonance imaging (MRI) burden of cerebral small vessel disease (cSVD) in this process. METHODS: 384 RSSI patients and 189 matched healthy controls were strictly registered in the current research. We evaluated short-term and long-term outcomes by measuring the percentage of the National Institutes of Health Stroke Scale (NIHSS) improvement and the modified Rankin Scale (mRS) at 3 months, respectively. We also assessed the chronic, sustained brain damage associated with cSVD using the total MRI burden and confirmed the relationship between prognosis and the total MRI burden of cSVD. Furthermore, we explored the associations between D-dimer and C-reactive protein (CRP) levels with NIHSS improvement and mRS at 3 months, as well as their relationships with both the total MRI burden of cSVD and its 4 imaging features. RESULTS: Both NIHSS improvement and the mRS at 3 months were found to be correlated with the total MRI burden of cSVD. Higher D-dimer and CRP levels showed a linear correlation, indicating worse prognosis and a higher total MRI burden of cSVD. The four imaging features of the total MRI burden of cSVD did not exhibit entirely consistent patterns when exploring their correlations with prognosis and laboratory indicators. CONCLUSION: Inflammation-associated D-dimer predicts neurological outcomes in patients with recent small subcortical infarct, and reflects a more severe total MRI burden of cSVD.

A Novel Mechanical Frequency Tuning Method Based on Mass-Stiffness Decoupling for MEMS Gyroscopes.

MEMS gyroscopes play an important role in inertial navigation measurements, which mainly works in n = 2 mode. However, mode matching is the basis for high-precision detection, which can improve the sensitivity, resolution, and signal-to-noise ratio of the gyroscopes. An initial frequency split is inevitably generated during the manufacturing process. There are two methods to eliminate the frequency split and to achieve mode matching for the gyroscopes, which are electrostatic tuning and mechanical trimming, respectively. In this paper, we report a novel ring MEMS resonator and a novel method of mechanical frequency tuning. The most prominent characteristic of the resonator is that 16 raised mass blocks are increased in the circumferential positions of the ring uniformly. This structural design can achieve mass-stiffness decoupling, which means that punching holes on the mass blocks only affects the mass distribution but the stiffness is almost unchanged for the resonator. We verify the mass-stiffness decoupling by way of comparing the simulation with the conventional resonator. In addition, we put up an online tuning platform based on a femtosecond laser and reduce a resonator's frequency split from 23.3 Hz to 0.4 Hz, which reveals that the frequency split is linearly related to the removed mass. These findings will have a referential significance for other transducers.

A supramolecularly tunable chiral diphosphine ligand: application to Rh and Ir-catalyzed enantioselective hydrogenation.

A supramolecularly tunable chiral bisphosphine ligand bearing two pyridyl-containing crown ethers, (-) or (+)-Xyl-P16C6-Phos, was fabricated and utilized in the Rh-catalyzed asymmetric hydrogenation of α-dehydroamino acid esters and Ir-catalyzed asymmetric hydrogenation of quinolines in high yields with excellent enantioselectivities (90-99% ee). Up to a 22% enhancement in enantioselectivity was achieved by the addition of certain amounts of alkali ions (Li+, Na+ or K+), which could be selectively recognized and effectively complexed by the crown ethers on the chiral Xyl-P16C6-Phos.

Synthesis of novel dendrimer-like star block copolymers with definite numbers of arms by combination of ROP and ATRP.

Well-defined biodegradable dendrimer-like star block copolymers with up to 24 arms were successfully synthesized by combination of living ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP) on the basis of dendritic benzyl alcohols.

Inhibition of mCD14 inhibits TNFα secretion and NO production in RAW264.7 cells stimulated by Brucella melitensis infection.

Brucellosis, caused by Brucella spp., is an important disease affecting not only human health, but also a number of animal species around the world. A receptor for LPS of Brucella and important innate immune molecule, CD14, has been implicated in the initiation of the inflammatory response to sepsis. Evidence indicates that upstream inhibition of the LPS initiated inflammatory pathway is an effective therapeutic approach for attenuating damaging immune activation. The aim of this study was to explore the possibility of using RNA interference (RNAi) targeting mCD14 as a strategy for inhibiting the secretion of tumor necrosis factor alpha (TNFα) and the production of nitric oxide (NO) from Brucella-stimulated RAW264.7 cells and attenuating damaging immune activation. The current study stably incorporated mCD14-shRNA-224 into the RAW264.7 cell line by lentiviral gene transfer to successfully knockdown mCD14, and was then challenged with Brucella melitensis M5-90. The secretion of TNFα, interleukin (IL)-12, CXCL1/KC, and inducible nitric oxide synthase (iNOS) protein expression, and NO production were evaluated. The mCD14-shRNA-224 knockdown was shown to effectively inhibit B. melitensis M5-90-stimulated TNFα release, iNOS protein expression, and NO production, but no significant differences were observed for IL-12 and CXCL1/KC. These findings provide the basis for the development of RNAi-based prophylaxis and therapy for B. melitensis induced inflammatory disease.