Towards a live homogeneous database of solar active regions based on SOHO/MDI and SDO/HMI synoptic magnetograms. I. Automatic detection and calibration

Recent studies indicate that a small number of rogue solar active regions (ARs) may have a significant impact on the end-of-cycle polar field and the long-term behavior of solar activity. The impact of individual ARs can be qualified based on their magnetic field distribution. This motivates us to build a live homogeneous AR database in a series of papers. As the first of the series, we develop a method to automatically detect ARs from 1996 onwards based on SOHO/MDI and SDO/HMI synoptic magnetograms. The method shows its advantages in excluding decayed ARs and unipolar regions and being compatible with any available synoptic magnetograms. The identified AR flux and area are calibrated based on the co-temporal SDO/HMI and SOHO/MDI data. The homogeneity and reliability of the database are further verified by comparing it with other relevant databases. We find that ARs with weaker flux have a weaker cycle dependence. Stronger ARs show the weaker cycle 24 compared with cycle 23. Several basic parameters, namely, location, area, and flux of negative and positive polarities of identified ARs are provided in the paper. This paves the way for AR's new parameters quantifying the impact on the long-term behavior of solar activity to be presented in the subsequent paper of the series. The constantly updated database covering more than two full solar cycles will be beneficial for the understanding and prediction of the solar cycle. The database and the detection codes are accessible online.Comment: Accepted for publication in the Astrophysical Journal Supplement Series. 14 pages, 8 figures, 3 table

The Sun's Magnetic Power Spectra Over Two Solar Cycles. I. Calibration Between SDO/HMI And SOHO/MDI Magnetograms

The Sun's magnetic field is strongly structured over a broad range of scales. The magnetic spatial power spectral analysis provides a powerful tool to understand the various scales of magnetic fields and their interaction with plasma motion. We aim to investigate the power spectra using spherical harmonic decomposition of high-resolution SOHO/MDI and SDO/HMI synoptic magnetograms covering three consecutive solar cycle minima in a series of papers. As the first of the series, we calibrate and analyze the power spectra based on co-temporal SDO/HMI and SOHO/MDI data in this paper. For the first time, we find that the calibration factor $r$ between SOHO/MDI and SDO/HMI varies with the spatial scale $l$ of the magnetic field, where $l$ is the degree of a spherical harmonics. The calibration factor satisfies $r(l)=\sqrt{-0.021 l^{0.64}+2} \quad(5<\mathrm{l}\leq539)$. With the calibration function, most contemporaneous SOHO/MDI and SDO/HMI magnetograms show consistent power spectra from about 8 Mm to the global scales over about 3 orders of magnitudes. Moreover, magnetic power spectra from SOHO/MDI and SDO/HMI maps show peaks/knees at $l\approx120$ corresponding to the typical supergranular scale (about 35 Mm) constrained from direct velocimetric measurements. This study paves the way for investigating the solar-cycle dependence of supergranulation and magnetic power spectra in subsequent studies.Comment: Accepted for publication in the Astrophysical Journal. 15 pages, 7 figures, 2 table

Sequence homolog-based molecular engineering for shifting the enzymatic pH optimum

AbstractCell-free synthetic biology system organizes multiple enzymes (parts) from different sources to implement unnatural catalytic functions. Highly adaption between the catalytic parts is crucial for building up efficient artificial biosynthetic systems. Protein engineering is a powerful technology to tailor various enzymatic properties including catalytic efficiency, substrate specificity, temperature adaptation and even achieve new catalytic functions. However, altering enzymatic pH optimum still remains a challenging task. In this study, we proposed a novel sequence homolog-based protein engineering strategy for shifting the enzymatic pH optimum based on statistical analyses of sequence-function relationship data of enzyme family. By two statistical procedures, artificial neural networks (ANNs) and least absolute shrinkage and selection operator (Lasso), five amino acids in GH11 xylanase family were identified to be related to the evolution of enzymatic pH optimum. Site-directed mutagenesis of a thermophilic xylanase from Caldicellulosiruptor bescii revealed that four out of five mutations could alter the enzymatic pH optima toward acidic condition without compromising the catalytic activity and thermostability. Combination of the positive mutants resulted in the best mutant M31 that decreased its pH optimum for 1.5 units and showed increased catalytic activity at pH < 5.0 compared to the wild-type enzyme. Structure analysis revealed that all the mutations are distant from the active center, which may be difficult to be identified by conventional rational design strategy. Interestingly, the four mutation sites are clustered at a certain region of the enzyme, suggesting a potential “hot zone” for regulating the pH optima of xylanases. This study provides an efficient method of modulating enzymatic pH optima based on statistical sequence analyses, which can facilitate the design and optimization of suitable catalytic parts for the construction of complicated cell-free synthetic biology systems

The Efficacy and Safety of Radiofrequency Ablation for Bilateral Papillary Thyroid Microcarcinoma

ObjectiveTo investigate the long-term clinical results of radiofrequency ablation (RFA) for bilateral papillary thyroid microcarcinoma (PTMC).Materials and MethodsFrom October 2014 to February 2018, 47 patients (37 females, 10 males, mean age 43.39 ± 9.26 years) with 100 bilateral PTMC (mean volume 75.22 ± 73.87 mm3) treated by RFA were included in this retrospective study. Bilateral PTMC was defined as at least one tumor located in the contralateral lobe. Patients were followed up at 1, 3, 6, 12 months and every 6–12 months thereafter. Volume, volume reduction ratio (VRR) and local tumor recurrence were evaluated during the follow-up period.ResultsAfter a mean follow-up period of 47.77 ± 11.54 months, the mean volume of bilateral PTMC decreased from 75.22 ± 73.87 mm3 to 0.09 ± 0.44 mm3. The mean VRR was 99.94 ± 0.28% and the complete disappearance rate was 92.00%. During the follow-up, one patient (2.13%) developed lymph node metastasis and two patients (4.26%) had recurrent PTMC. All the recurrent lesions underwent additional RFA and two of them disappeared completely. No life-threatening or delayed complications occurred.ConclusionsWith sufficient preoperative evaluation, RFA might be a promising alternative for bilateral PTMC patients who were unsuitable for surgery or refused surgery

Differences of microscopic seepage mechanisms of water flooding and polymer flooding and prediction models of final oil recovery for conglomerate reservoir

The special sedimentary environments of conglomerate reservoir lead to pore structure characteristics of complex modal, and the reservoir seepage system is mainly in the “sparse reticular-non reticular” flow pattern. As a result, the study on microscopic seepage mechanism of water flooding and polymer flooding and their differences becomes the complex part and key to enhance oil recovery. In this paper, the actual core samples from conglomerate reservoir in Karamay oilfield are selected as research objects to explore microscopic seepage mechanisms of water flooding and polymer flooding for hydrophilic rock as well as lipophilic rock by applying the Computed Tomography (CT) scanning technology. After that, the final oil recovery models of conglomerate reservoir are established in two displacement methods based on the influence analysis of oil displacement efficiency. Experimental results show that the seepage mechanisms of water flooding and polymer flooding for hydrophilic rock are all mainly “crawling” displacement along the rock surface while the weak lipophilic rocks are all mainly “inrushing” displacement along pore central. Due to the different seepage mechanisms among the water flooding and the polymer flooding, the residual oil remains in hydrophilic rock after water flooding process is mainly distributed in fine throats and pore interchange. These residual oil are cut into small droplets under the influence of polymer solution with stronger shearing drag effect. Then, those small droplets pass well through narrow throats and move forward along with the polymer solution flow, which makes enhancing oil recovery to be possible. The residual oil in weak lipophilic rock after water flooding mainly distributed on the rock particle surface and formed oil film and fine pore-throat. The polymer solution with stronger shear stress makes these oil films to carry away from particle surface in two ways such as bridge connection and forming oil silk. Because of the essential attributes differences between polymer solution and injection water solution, the impact of Complex Modal Pore Structure (CMPS) on the polymer solution displacement and seepage is much smaller than on water flooding solution. Therefore, for the two types of conglomerate rocks with different wettability, the pore structure is the main controlling factor of water flooding efficiency, while reservoir properties oil saturation, and other factors have smaller influence on flooding efficiency although the polymer flooding efficiency has a good correlation with remaining oil saturation after water flooding. Based on the analysis on oil displacement efficiency factors, the parameters of water flooding index and remaining oil saturation after water flooding are used to establish respectively calculation models of oil recovery in water flooding stage and polymer flooding stage for conglomerate reservoir. These models are able to calculate the oil recovery values of this area controlled by single well control, and further to determine the oil recovery of whole reservoir in different displacement stages by leveraging interpolation simulation methods, thereby providing more accurate geological parameters for the fine design of displacement oil program

Ex vivo mono-ring technique simplifies culotte stenting for treatment of true bifurcation lesions: Insights from bench testing and clinical application

Background: Despite various culotte-based stenting techniques available clinically, the optimal one remains undetermined. The study aimed to test whether ex vivo mono-ring culotte stenting (MRC) was technically feasible and superior to mini culotte stenting (MCS) in treatment of coronary bifurcation lesions.Methods: Mono-ring culotte stenting was characterized by ex vivo wiring of the most proximal cell of the side branch (SB) stent to ensure a mono-ring result of the culotte stenting. Comparison of MRC vs. MCS in treatment of true bifurcation lesions was performed in vitro (n = 15 for each group) and in clinical case-controlled study with propensity matching at a ratio of 1:2 (n = 21 for MRC group; n = 42 for MCS group).Results: Compared to MCS, MRC had lower incidence of stent under-expansion band (0% vs. 53.3%, p = 0.002) and less residual ostial area stenosis of SB (9.2 ± 9.0% vs. 20.0 ± 14.8%, p = 0.023), as assessed in vitro by micro-computed tomography. In a case-controlled study, no adverse cardiac events were observed in the MRC group. The procedural success was similar between MRC and MCS (100% vs. 95.2%, p = 0.548), but MRC had less residual ostial stenosis of the SB (8.7% ± 11.0% vs. 16.8% ± 11.2%, p = 0.008), lower procedural(33.3 ± 9.5 min vs. 46.7 ± 15.6 min, p = 0.001) and fluoroscopic (19.7 ± 4.9 min vs. 26.2 ± 7.1 min, p &lt; 0.001) time, and less contrast use (114.3 ± 28.9 mL vs. 156.5 ± 56.4 mL, p = 0.002).Conclusions: Mono-ring culotte stenting as compared to MCS is associated with better bifurcation stent morphology,less procedural complexity and residual ostial SB stenosis

Effect of Low-Density Lipoprotein Cholesterol Goal Achievement on Vascular Physiology Evaluated by Quantitative Flow Ratio in Patients Who Underwent Percutaneous Coronary Intervention

Purpose: The change in coronary physiology from lipid-lowering therapy (LLT) lacks an appropriate method of examination. Quantitative flow ratio (QFR) is a novel angiography-based approach allowing rapid assessment of coronary physiology. This study sought to determine the impact of low-density lipoprotein cholesterol (LDL-C) goal achievement on coronary physiology through QFR.Methods: Cases involving percutaneous coronary intervention (PCI) and 1-year angiographic follow-up were screened and assessed by QFR analysis. Patients were divided into two groups according to the LDL-C level at the 1-year follow-up: (1) goal-achievement group (LDL-C &lt; 1.8 mmol/L or reduction of ≥50%, n = 146, lesion = 165) and (2) non-achievement group (n = 286, lesion = 331). All QFR data and major adverse cardiovascular and cerebrovascular events (MACCEs) at 1 year were compared between groups.Results: No differences between the groups in quantitative coronary angiography (QCA) data or QFR post-PCI were found. At the 1-year follow-up, lower percentage diameter stenosis (DS%) and percentage area stenosis (AS%) were recorded in the goal-achievement group (27.89 ± 10.16 vs. 30.93 ± 12.03, p = 0.010, 36.57 ± 16.12 vs. 41.68 ± 17.39, p = 0.003, respectively). Additionally, a better change in QFR was found in the goal-achievement group (0.003 ± 0.068 vs. −0.018 ± 0.086, p = 0.007), with a lower incidence of physiological restenosis and MACCEs (2.1 vs. 8.4%, p = 0.018, 5.4 vs. 12.6%, p = 0.021, respectively).Conclusion: Evaluated by QFR, patients who achieved the LDL-C goal appear to have a better coronary physiological benefit. This group of patients also has a better clinical outcome