Passability test and simulation of sand control string with natural gas hydrates completion in large curvature hole

To meet the requirements of marine natural gas hydrate exploitation,it is necessary to improve the penetration of completion sand control string in the large curvature borehole.In this study,large curvature test wells were selected to carry out the running test of sand control string with pre-packed screen.Meanwhile,the running simulation was performed by using the Landmark software.The results show that the sand control packer and screen can be run smoothly in the wellbore with a dogleg angle of more than 20°/30 m and keep the structure stable.Additionally,the comprehensive friction coefficient is 0.4,under which and the simulation shows that the sand control string for hydrate exploitation can be run smoothly.These findings have important guiding significance for running the completion sand control string in natural gas hydrate exploitation.

Design and Imaging Application of Room-Temperature Terahertz Detector with Micro-Bolometer Focal Plane Array

Room-temperature terahertz （THz） detectors indicate a great potential in the imaging application because of their real-time, compact bulk, and wide spectral band responding characteristics. THz detectors with different dimensions based on a micro-bridge structure have been designed and fabricated to get optimized micro-bolometer parameters from the test results of membrane deformation. A nanostructured titanium （Ti） thin film absorber is integrated in the micro-bridge structure of the VOx micro-bolometer by a combined process of magnetron sputtering and reactive ion etching （RIE）, and its improvement of THz absorption is verified by an optical characteristics mesurement. Continuous-wave THz detection and imaging are demonstrated by using a 2.52 THz far infrared CO2 laser and a 320x240 vanadium oxide micro-bolometer focal plane array with an optimized cell structure. With this detecting system, THz imaging of metal concealed in a wiping cloth and an envelope is demonstrated, respectively.

Danggui Sini decoction treatment of refractory allergic cutaneous vasculitis:A case report

BACKGROUND Allergic cutaneous vasculitis(ACV)is a difficult disease to treat.At present,there is no effective treatment for this condition.Traditionally,immunosuppressants and hormones have been primarily used in its management,but the treatment effect is suboptimal,and it has several side effects.CASE SUMMARY We present the case of a 19-year-old woman who presented at our hospital with a four-year history of symmetric skin lesions mainly affecting her lower extremities.She had previously undergone treatment with prednisolone acetate,cetirizine hydrochloride,and loratadine tablets but had not experienced any relief in her condition.Thereafter,she was treated with oral traditional Chinese medicine.Her skin damage gradually improved within two months of treatment initiation.After six months,the skin ulcers had completely subsided.No evidence of skin ulcer recurrence was observed during the subsequent follow-up.This report presents the first case of a female patient who received oral Danggui Sini decoction for the treatment of ACV.CONCLUSION Danggui Sini decoction may be a promising oral treatment for ACV patients.

Effect of negative remodeling of the side branch ostium on the efficacy of a two-stent strategy for distal left main bifurcation lesions:an intravascular ultrasound study

OBJECTIVES To investigate whether negative remodeling(NR)detected by intravascular ultrasound(IVUS)of the side branch ostium(SBO)would affect in-stent neointimal hyperplasia(NIH)at the one-year follow-up and the clinical outcome of target lesion failure(TLF)at the long-term follow-up for patients with left main bifurcation(LMb)lesions treated with a two-stent strategy.METHODS A total of 328 patients with de novo true complex LMb lesions who underwent a 2-stent strategy of percutaneous coronary intervention(PCI)treatment guided by IVUS were enrolled in this study.We divided the study into two phases.Of all the patients,48 patients who had complete IVUS detection pre-and post-PCI and at the 1-year follow-up were enrolled in phase I analysis,which aimed to analyze the correlation between NR and in-stent NIH at SBO at the 1-year follow-up.If the correlation was confirmed,the cutoff value of the remodeling index(RI)for predicting NIH≥50%was analyzed next.The phase II analysis focused on the incidence of TLF as the primary endpoint at the 1-to 5-year follow-up for all 328 patients by grouping based on the cutoff value of RI.RESULTS In phase I:according to the results of a binary logistic regression analysis and receiver operating characteristic(ROC)analysis,the RI cutoff value predicting percent NIH≥50%was 0.85 based on the ROC curve analysis,with a sensitivity of 85.7%,a specificity of 88.3%,and an AUC of 0.893(0.778,1.000),P=0.002.In phase II:the TLR rate(35.8%vs.5.3%,P<0.0001)was significantly higher in the several NR(sNR,defined as RI≤0.85)group than in the non-sNR group.CONCLUSION The NR of LCxO is associated with more in-stent NIH post-PCI for distal LMb lesions with a 2-stent strategy,and NR with RI≤0.85 is linked to percent NIH area≥50%at the 1-year follow-up and more TLF at the 5-year follow-up.

Spontaneous Coronary Artery Dissection as a Cause of Acute Myocardial Infarction in Young Female Population： A Single-center Study

Background： Spontaneous coronary artery dissection （SCAD） is a nonatherosclerotic but a rare and extremely dangerous clinical entity, it has a high prevalence in young female population with acute myocardial infarction （AMI）. The previous reports were restricted to other countries＇ population, but rare in China. Hence, this study aimed to focus on the characteristics of SCAD as a cause of young female AMI population in Jiangsu, China. Methods： This study enrolled young female AMI patients aged ≤50 years who underwent coronary angiography （CAG） and intracoronary imaging in our center between January 2013 and December 2016. Their clinical presentations, risk factors, and CAG characteristics were analyzed. Results： A total of 60 young l＇emale AMI （〈7 days） patients were enrolled. From their CAG and intracoronary imaging results, the prevalence of SCAD in young female AMI population was 35% （21/60）, the prevalence of coronary atherosclerostic heart disease was 65% （39/60）. In the SCAD group, 43% （9/21） presented with non-ST-elevation myocardial infarction （NSTEM1） and the remainder presenting as STEMI. SCAD usually occurred in a single vessel （20/21, 95%）, especially in left anterior descending artery （14/21, 67%）. Eighteen patients （18/21, 86%） underwent conservative treatment, whereas the remaining three patients （3/21, 14%） underwent percutaneous coronary intervention. Regarding the angiographic results of SCAD lesions, intramural hematoma was discriminated in 95% （20/21）, and Type I imaging was observed in 5% （1/21）, Type l I was observed in 67% （14/21）, and Type Ⅲ was 29% （6/21）. The average stenosis in the group was 76.9% - 20.6%, and the mean lesion length was 36.6 ± 8.6 ±m. Conclusions： SCAD has a high prevalence in young female AMI population in Jiangsu, China. Discriminating the cause of AMI in young female population is very important.

Intensive statin versus low-dose statin + ezetimibe treatment for fibrous cap thickness of coronary vulnerable plaques

Background:Acute coronary syndromes mainly result from abrupt thrombotic occlusion caused by atherosclerotic vulnerable plaques (VPs) that suddenly rupture or erosion. Fibrous cap thickness (FCT) is a major determinant of the propensity of a VP to rupture and is recognized as a key factor. The intensive use of statins is known to have the ability to increase FCT;however, there is a risk of additional adverse effects. However, lower dose statin with ezetimibe is known to be tolerable by patients. The present study aimed to investigate the effect of intensive statin vs. low-dose stain + ezetimibe therapy on FCT, as evaluated using optical coherence tomography. Method:Patients who had VPs (minimum FCT <65 μm and lipid core >90°) and deferred from intervention in our single center from January 2014 to December 2018 were included in the trial. They were divided into the following two groups: intensive statin group (rosuvastatin 15-20 mg or atorvastatin 30-40 mg) and combination therapy group (rosuvastatin 5-10 mg or atorvastatin 10-20 mg + ezetimibe 10 mg). At the 12-month follow-up, we compared the change in the FCT (ΔFCT%) between the two groups and analyzed the association of ΔFCT% with risk factors. Fisher exact test was used for all categorical variables. Student’s t test or Mann-Whitney U-test was used for analyzing the continuous data. The relationship between ΔFCT% and risk factors was analyzed using linear regression analysis. Result:Total 53 patients were finally enrolled, including 26 patients who were in the intensive statin group and 27 who were in the combination therapy group. At the 12-month follow-up, the serum levels of total cholesterol (TC), total triglyceride, low-density lipoprotein (LDL-C), hypersensitive C-reactive protein (hs-CRP), and lipoprotein-associated phospholipase A2 (Lp-PLA2) levels were reduced in both the groups. The ΔTC%, ΔLDL-C%, and ΔLp-PLA2% were decreased further in the combination therapy group. FCT was increased in both the groups (combination treatment group vs. intensive statin group: 128.89 ± 7.64 vs. 110.19 ± 7.00 μm, t = -9.282, P < 0.001) at the 12-month follow-up. The increase in ΔFCT% was more in the combination therapy group (123.46% ± 14.05% vs. 91.14% ± 11.68%, t = -9.085, P < 0.001). Based on the multivariate linear regression analysis, only the serum Lp-PLA2 at the 12-month follow-up ( B = -0.203, t = -2.701, P = 0.010), ΔTC% ( B = -0.573, t = -2.048, P = 0.046), and Δhs-CRP% ( B = -0.302, t = -2.963, P = 0.005) showed an independent association with ΔFCT%. Conclusions:Low-dose statin combined with ezetimibe therapy maybe provide a profound and significant increase in FCT as compared to intensive statin monotherapy. The reductions in Lp-PLA2, ΔTC%, and Δhs-CRP% are independently associated with an increase in FCT.

Safety and immunogenicity of a recombinant COVID-19 vaccine(Sf9 cells)in healthy population aged 18 years or older:two single-center,randomised,double-blind,placebo-controlled,phase 1 and phase 2 trials

COVID-19 vaccines from multiple manufacturers are needed to cope with the problem of insufficient supply.We did two singlecenter,randomised,double-blind,placebo-controlled phase 1 and phase 2 trials to assess the safety,tolerability and immunogenicity of a recombinant COVID-19 vaccine(Sf9 cells)in healthy population aged 18 years or older in China.Eligible participants were enrolled,the ratio of candidate vaccine and placebo within each dose group was 3:1(phase 1)or 5:1(phase 2).From August 28,2020,168 participants were sequentially enrolled and randomly assigned to receive the low dose vaccine,high dose vaccine or placebo with the schedule of 0,28 days or 0,14,28 days in phase 1 trial.From November 18,2020,960 participants were randomly assigned to receive the low dose vaccine,high dose vaccine or placebo with the schedule of 0,21 days or 0;14,28 days in phase 2 trial.The most common solicited injection site adverse reaction within 7 days in both trials was pain.The most common solicited systematic adverse reactions within 7 days were fatigue,cough,sore throat,fever and headache.ELISA antibodies and neutralising antibodies increased at 14 days,and peaked at 28 days(phase 1)or 30 days(phase 2)after the last dose vaccination.The GMTs of neutralising antibody against live SARS-CoV-2 at 28 days or 30 days after the last dose vaccination were highest in the adult high dose group(0,14,28 days),with 102.9(95%Cl 61.9-171.2)and 102.6(95%Cl 75.2-140.1)in phase 1 and phase 2 trials,respectively.Specific T-cell response peaked at 14 days after the last dose vaccination in phase 1 trial.This vaccine is safe,and induced significant immune responses after three doses of vaccination.

Cut-off values of lesion and vessel quantitative flow ratio in de novo coronary lesion post-drug-coated balloon therapy predicting vessel restenosis at mid-term follow-up

Background:Drug-coated balloons(DCBs)have emerged as potential alternatives to drug-eluting stents in specific lesion subsets for de novo coronary lesions.Quantitative flow ratio(QFR)is a method based on the three-dimensional quantitative coronary angiography and contrast flow velocity during coronary angiography(CAG),obviating the need for an invasive fractional flow reserve procedural.This study aimed to assess the serial angiographic changes of de novo lesions post-DCB therapy and further explore the cut-off values of lesion and vessel QFR,which predict vessel restenosis(diameter stenosis[DS]≥50%)at mid-term follow-up.Methods:The data of patients who underwent DCB therapy between January 2014 and December 2019 from the multicenter hospital were retrospectively collected for QFR analysis.From their QFR performances,which were analyzed by CAG images at follow-up,we divided them into two groups:group A,showing target vessel DS≥50%,and group B,showing target vessel DS<50%.The median follow-up time was 287 days in group A and 227 days in group B.We compared the clinical characteristics,parameters during DCB therapy,and QFR performances,which were analyzed by CAG images between the two groups,in need to explore the cut-off value of lesion/vessel QFR which can predict vessel restenosis.Student's t test was used for the comparison of normally distributed continuous data,Mann-Whitney U test for the comparison of non-normally distributed continuous data,and receiver operating characteristic(ROC)curves for the evaluation of QFR performance which can predict vessel restenosis(DS≥50%)at mid-term follow-up using the area under the curve(AUC).Results:A total of 112 patients with 112 target vessels were enrolled in this study.Group A had 41 patients,while group B had 71.Vessel QFR and lesion QFR were lower in group A than in group B post-DCB therapy,and the cut-off values of lesion QFR and vessel QFR in the ROC analysis to predict target vessel DS≥50%post-DCB therapy were 0.905(AUC,0.741[95%confidence interval,CI:0.645,0.837];sensitivity,0.817;specificity,0.561;P<0.001)and 0.890(AUC,0.796[95%CI:0.709,0.882];sensitivity,0.746;specificity,0.780;P<0.001).Conclusions:The cut-off values of lesion QFR and vessel QFR can assist in predicting the angiographic changes post-DCB therapy.When lesion/vessel QFR values are<0.905/0.890 post-DCB therapy,a higher risk of vessel restenosis is potentially predicted at follow-up.