Crystal plasticity based modeling of grain boundary sliding in magnesium alloy AZ31B sheet

The aim of present work is to develop a crystal plasticity modeling approach to integrate slip,dynamic recrystallization(DRX)and grain boundary sliding(GBS)for simulating the deformation behavior and texture evolution of magnesium alloys at high temperatures.Firstly,the deformation mechanisms of an AZ31B Mg alloy sheet at 300°C were investigated by examining texture and microstructure evolution during uniaxial tension and compression tests.DRX refines microstructure at strains less than 0.2,and subsequently GBS plays a significant role during deformation process.A GBS model is developed to evaluate strain and grain rotation induced by GBS,and implemented into the polycrystal plasticity framework VPSC.The VPSC-DRX-GBS model can well reproduce the stress−strain curves,grain size,texture evolution and significant texture differences in tension and compression tests due to GBS.The calculated GBS contribution ratio in tension is obviously higher than that in compression due to easier cavity nucleation at grain boundaries under tension loading.

On the Relation Between Coronal Green Line Brightness and Magnetic Fields Intensity

Two-dimensional(2 D) solar coronal magnetogram is difficult to be measured directly until now.From the previous knowledge,a general relation has been noticed that the brighter green-line brightness for corona,the higher coronal magnetic field intensity may correspond to.To try to further reveal the relationship between coronal green line brightness and magnetic field intensity,we use the 2 D coronal images observed by Yunnan Observatories Greenline Imaging System(YOGIS) of the 10 cm Lijiang coronagraph and the coronal magnetic field maps calculated from the current-free extrapolations with the photospheric magnetograms taken by Helioseismic and Magnetic Imager(HMI) on board the Solar Dynamics Observatory(SDO) spacecraft.In our analysis,we identified the coronal loop structures and construct two-dimensional maps of the corresponding magnetic field intensity in the plane of the sky(POS) above the limb.We derive the correlation coefficients between the coronal brightness and the magnetic field intensity for different heights of coronal layers.We further use a linear combination of a Gaussian and a quadratic profile to fit the correlation coefficients distribution,finding a largest correlation coefficient of 0.82 near 1.1 R(solar radii) where is almost the top of the closed loop system.For the small closed loop system identified,the correlation coefficient distributions crossing and covering the loop are calculated.We also investigate the correlation with extended heliocentric latitude zones and long period of one whole Carrington Rotation,finding again that the maximum correlation coefficient occurs at the same height.It is the first time for us to find that the correlation coefficients are high(all are larger than 0.8) at the loop-tops and showing poor correlation coefficients with some fluctuations near the feet of the coronal loops.Our findings indicate that,for the heating of the low-latitude closed loops,both DC(dissipation of currents) and AC(dissipation of Alfvén and magnetosonic waves) mechanisms should act simultaneously on the whole closed loop system while the DC mechanisms dominate in the loop-top regions.Therefore,in the distributions of the correlation coefficients with different heights of coronal layers,for both large-and small-scale latitude ranges,the coefficients can reach their maximum values at the same coronal height of 1.1 R,which may indicate the particular importance of the height of closed loops for studying the coupling of the local emission mechanism and the coronal magnetic fields,which maybe helpful for studying the origin of the low-speed solar wind.

Clinical online nomogram for predicting prognosis in recurrent hepatolithiasis after biliary surgery:A multicenter,retrospective study

BACKGROUND Methods for predicting the prognosis of patients undergoing surgery for recurrent hepatolithiasis after biliary surgery are currently lacking.AIM To establish a nomogram to predict the prognosis of patients with recurrent hepatolithiasis after biliary surgery.METHODS In this multicenter,retrospective study,data of consecutive patients in four large medical centers who underwent surgery for recurrent hepatolithiasis after biliary surgery were retrospectively analyzed.We constructed a nomogram to predict the prognosis of recurrent hepatolithiasis in a training cohort of 299 patients,following which we independently tested the nomogram in an external validation cohort of 142 patients.Finally,we used the concordance index(C-index),calibration,area under curve,decision curve analysis,clinical impact curves,and visual fit indices to evaluate the accuracy of the nomogram.RESULTS Multiple previous surgeries[2 surgeries:Odds ratio(95%confidence interval),1.451(0.719-2.932);3 surgeries:4.573(2.015-10.378);≥4 surgeries:5.741(1.347-24.470)],bilateral hepatolithiasis[1.965(1.039-3.717)],absence of immediate clearance[2.398(1.304-4.409)],neutrophil-to-lymphocyte ratio≥2.462[1.915(1.099-3.337)],and albumin-to-globulin ratio≤1.5[1.949(1.056-3.595)]were found to be independent factors influencing the prognosis.The nomogram constructed on the basis of these variables showed good reliability in the training(C-index:0.748)and validation(C-index:0.743)cohorts.Compared with predictions using traditional classification models,those using our nomogram showed better agreement with actual observations in the calibration curve for the probability of endpoints and the receiver operating characteristic curve.Dichloroacetate and clinical impact curves showed a larger net benefit of the nomogram.CONCLUSION The nomogram developed in this study demonstrated superior performance and discriminative power compared to the three traditional classifications.It is easy to use,highly accurate,and shows excellent calibration.

Comparison of the Coronal Green-line Intensities with the EUV Measurements from SDO/AIA

The intensity of the green line(Fe ⅩⅣ 5303 A) is the strongest in the visible spectrum of the solar corona,and this line has been used as long-term powerful diagnostic tools for studying the coronal configurations and hot plasma dynamics.However,it remains unclear and an open question whether there exists close relationship between the green line intensities and the coronal extreme ultraviolet(EUV) line emissions for various coronal structures.In this paper,we use the green-line data by the Lijiang YOGIS Lyot coronagraph and the EUV data from the Solar Dynamics Observatory/Atmospheric Imaging Assembly instruments in order to perform direct comparisons and analyses,based on two algorithms developed to extract particular features in the low corona.It is found that,among the correlation coefficients obtained between the intensities of 5303 A and the EUV lines,the coefficients between the green line and the 211 A wavelength for different coronal structures and different limb locations always keep the highest values(ranging from 0.89 to 0.99),which has not been reported before.This result can be helpful and promising to link together the various physical processes involved at different heights in the corona by precisely tracking the bright loops or other features observed in 5303 A above the limb down to the correct surface locations revealed by the 211 A data.Furthermore,the ground-based observations of the coronal green line and the space-based EUV observations at 211 A can advantageously complement each other when there is a need.

Rapid progression of heart failure secondary to radioactive iodine treatment of hyperthyroidism:A case report

BACKGROUND The deterioration of thyroid health is involved in the progression of heart failure(HF).This is usually a lengthy process,so there are almost no reports on its rapid development.Here we report a case of a young male who rapidly developed hypothyroid cardiomyopathy secondary to radioactive iodine treatment,suggesting that severe HF might occur even after a short period of hypothyroidism.CASE SUMMARY A 26-year-old man was referred to our hospital for HF presenting with dyspnea on exertion and chest discomfort lasting for 1 mo.He received radioactive iodine treatment for hyperthyroidism 1 year ago and had an almost normal echocardiogram 6 mo ago.Admission echocardiogram and cardiac magnetic resonance(CMR)revealed left ventricle(LV)global hypokinesia and severely depressed systolic function.In addition,late gadolinium enhancement indicated no obvious changes in the myocardium.Thyroid function tests showed decreased serum levels of thyroid hormone(TH)and elevated thyroid-stimulating hormone.Based on an exclusionary examination,the patient was diagnosed with hypothyroid cardiomyopathy and was started on replacement therapy.His HF symptoms were completely relieved during the six-month follow-up,and echocardiogram and CMR revealed recovered LV size and ejection fraction.CONCLUSION This report demonstrates that severe fluctuations in TH levels may lead to acute HF,which can completely recover with timely thyroid hormone replacement.In addition,our findings highlight the importance of routinely detecting cardiac function in patients treated with radioactive iodine.

Increased Expression of Serum Monocyte Chemoattractant Protein-1,Chemokine(C-C motif)Ligand 3,and Interleukins in Patients With Vitiligo

Objective:Vitiligo is a chronic,acquired depigmentation of the skin,which can be divided into active and stable vitiligo.The stable and active stages are not immutable and often alternate.Identification of internal markers would help to diagnose the active stage of vitiligo,and the purpose of this study was to find potential active markers in the progression of vitiligo.Methods:We compared 30 healthy controls to 60 patients with vitiligo(30 with active disease and 30 with stable disease)regarding the expression of serum monocyte chemoattractant protein(MCP)-1,chemokine(C-C motif)ligand(CCL)3,CCL5,CCL21,interleukin(IL)-6,and IL-17.Specimens were collected from May 2017 to December 2018.Serological detection was carried out by enzyme-linked immunosorbent assay.The difference between groups was compared by Kruskal-Wallis H test and Mann-Whitney U test.Results:We found that the serum levels of MCP-1,CCL3,IL-6,and IL-17 were significantly higher in patients with vitiligo than in healthy controls(P<0.01)and that IL-17 was higher in patients with active vitiligo than in those with stable vitiligo(P<0.01).After 3months of treatment,the serum IL-17 level of patients with active vitiligo was not significantly different from that before treatment(P=0.526);after 6months of treatment,however,the serum IL-17 level had significantly decreased(P<0.01).Conclusion:These findings suggest that the serum IL-17 level can be used as a marker of vitiligo disease activity giving it certain guiding significance for clinical treatment.

Nomogram based on inflammation-related markers for predicting survival of patients undergoing hepatectomy for hepatocellular carcinoma

BACKGROUND Previous nomograms for hepatocellular carcinoma(HCC)did not include the neutrophil-to-lymphocyte ratio(NLR)or platelet-to-lymphocyte ratio(PLR).This study aimed to establish an effective nomogram capable of estimating the association between preoperative inflammatory factors and overall survival(OS)of HCC patients after hepatectomy.AIM To analyse the factors affecting the prognosis of HCC and establish a nomogram.METHODS A total of 626 HCC patients(410 training set patients from the First Affiliated Hospital of Anhui Medical University and 216 validation set patients from the First Affiliated Hospital of University of Science and Technology of China)underwent hepatectomy from January 2014 to December 2017 and were followed up every 3–6 mo.The nomogram was based on OS-related independent risk factors identified by Cox regression analysis.The C-index,calibration curve,and area under the curve(AUC)were used to evaluate the nomogram’s accuracy.RESULTS The 1-,2-and 3-year OS rates were 79.0%,68.0%and 45.4%in the training cohort(median OS=34 mo)and 92.1%,73.9%and 51.2%in the validation cohort(median OS=38 mo).Higherα-fetoprotein[hazard ratio(HR)=1.812,95%confidence interval(CI):1.343–2.444],NLR(HR=2.480,95%CI:1.856–3.312)and PLR(HR=1.974,95%CI:1.490–2.616),tumour size≥5 cm(HR=1.323,95%CI:1.002–1.747),and poor differentiation(HR=3.207,95%CI:1.944–5.290)were significantly associated with shortened OS.The developed nomogram integrating these variables showed good reliability in both the training(C-index=0.71)and validation cohorts(C-index=0.75).For predicting 1-,2-and 3-year OS,the nomogram had AUCs of 0.781,0.743 and 0.706 in the training cohort and 0.789,0.815 and 0.813 in the validation cohort.The nomogram was more accurate in predicting prognosis than the AJCC TNM staging system.CONCLUSION The prognostic nomogram combining pathological characteristics and inflammation indicators could provide a more accurate individualized risk estimate for the OS of HCC patients with hepatectomy.