[Pregnancy outcome analysis after radiofrequency ablation of monochorionic twin pregnancy in different gestational weeks and psychological intervention].

Objective: To investigate the effect of different gestational weeks and psychological intervention on pregnancy outcome in patients with monochorionic twin pregnancy. Methods: The clinical data of 68 patients with monochorionic twin pregnancy in the middle and late pregnancy who were treated with radiofrequency ablation in the First Affiliated Hospital of Zhengzhou University from March 2017 to April 2021 were retrospectively analyzed, including 54 patients with single chorionic and single amniotic sac and 14 patients with single chorionic and double amniotic sac. Patients were divided into three groups according to the gestational weeks:<20 weeks (n=36), 20-23 weeks (n=17) and ≥24 weeks (n=15); and were divided into intervention group (n=40) and control group (n=28) according to the preoperative psychological intervention. The pregnancy outcome of patients with different pregnancy reduction and the effect of psychological intervention on pregnancy outcome was analyzed. Results: The age of 68 patients was (30.2±4.6) years old, the gestational age was (22.2±3.2) weeks, and 60 cases (88.2%) were live births after fetal reduction. There were no significant difference in age [(31.8±4.7),(28.3±5.0),(30.3±4.0) years old] (P=0.098), abortion rate, preterm birth rate, live birth rate, delivery mode, gestational week of preterm birth, gestational week of delivery, and neonatal weight between the two groups at different gestational weeks (all P>0.05). The ages of the intervention group and the control group were (30.6±4.7) and (29.4±4.0) years old (P=0.352). After psychological intervention for 40 patients in the intervention group, the anxiety score after pregnancy reduction was reduced from (54.8±6.8) to (37.3±7.3) (P<0.001), while the depression score decreased from (62.7±7.2) to (33.2±2.4) (P<0.001). Compared with patients in the control group (12.5%, n=5), the proportion of postoperative discomfort in the intervention group was higher (53.6%, n=15) (P<0.001). Compared with the control group, there were no statistically significant difference in the postoperative preterm birth rate, abortion rate, live birth rate, delivery mode, gestational week of preterm birth, gestational week of delivery, and neonatal weight in the intervention group (all P>0.05). Conclusions: Radiofrequency ablation is a safe and effective minimally invasive technique. For complex monochorionic twin pregnancies, early fetal reduction (<20 weeks) and preoperative psychological intervention can provide a solid guarantee for a good postoperative pregnancy outcome.

[Evaluation and treatment strategy of limb length discrepancy after total hip arthroplasty].

Limb length discrepancy(LLD) is a common complication after total hip arthroplasty (THA). Good positioning of the prosthesis and suitable soft tissue tension are essential to ensure hip joint stability. Patients will be more satisfied if almost the same length of both lower extremities is achieved. Preoperative comprehensive evaluation of patients is helpful to prevent the occurrence of LLD after surgery. Therefore, the pelvic spine conditions, as well as type and cause of LLD should be analyzed in detail before surgery. During operation, limb length should be adjusted by touching the position of patella, Kirschner's wires positioning and referring to the relationship between the center of femoral head and the tip of greater trochanter. After surgery, it is necessary to clearly distinguish true LLD from functional LLD, and make a reasonable therapeutic plan according to patient's symptoms and the range of differences in limb length. This article reviews the latest literatures based on clinical practice experience and summarizes the research status of LLD after THA, which helps joint surgeons to have an in-depth understanding of this postoperative complication.

[Multimodal Magnetic Resonance and Fluorescence Imaging of the Induced Pluripotent Stem Cell Transplantation in the Brain].

The understanding of the engrafted cell behaviors such as the survival, growth and distribution is the prerequisite to optimize cell therapy, and a multimodal imaging at both anatomical and molecular levels is designed to achieve this goal. We constructed a lentiviral vector carrying genes of ferritin heavy chain 1 (FTH1), near-infrared fluorescent protein (iRFP) and enhanced green fluorescent protein (egfp), and established the induced pluripotent stem cells (iPSCs) culture stably expressing these three reporter genes. These iPSCs showed green and near-infrared fluorescence as well as the iron uptake capacity in vitro. After transplanted the labeled iPSCs into the rat brain, the engrafted cells could be in vivo imaged using magnetic resonance imaging (MRI) and near-infrared fluorescent imaging (NIF) up to 60 days at the anatomical level. Moreover, these cells could be detected using EGFP immunostaining and Prussian blue stain at the cellular level. The developed approach provides a novel tool to study behaviors of the transplanted cells in a multi-modal way, which will be valuable for the effectiveness and safety evaluation of cell therapy.

[COVID-19 vaccines primary features and research progress on possible trigger of liver injury post-vaccination].

The COVID-19 outbreak is a global pandemic that has had caused a profound impact on social stability, economic development and national security, and has further evolved into a major public health crisis. The rapid research and development and efficient deployment of vaccines is one of the effective means to prevent and control the epidemic. This article reviews the primary features of current COVID-19 vaccines, simultaneously focus the clinical features of liver injury post-vaccination and explore its possible pathogenesis.

[Cost-effectiveness of anti-tumor associated antigen autoantibody screening for hepatocellular carcinoma in the population with chronic hepatitis B-related cirrhosis].

Objective: To evaluate the cost-effectiveness of anti-tumor associated antigen autoantibody (TAAb) for hepatocellular carcinoma (HCC) screening in cirrhosis population with chronic hepatitis B (CHB). Methods: A simulated cohort of 40-year-old patients with CHB cirrhosis was established with a sample size of 10 000. Using TAAb screening alone or TAAb and AFP screening in parallel (TAAb + AFP) as the research strategy, and liver ultrasound and AFP screening in parallel (liver ultrasound + AFP) as the control strategy, the decision analysis Markov model was constructed and the model validity was evaluated. The 6-month cycle was simulated using TreeAge Pro 2020 software. Cost and quality-adjusted life years (QALY) were calculated. Incremental cost-effectiveness ratio (ICER) was used to compare the two strategies, and sensitivity analysis was used to evaluate the uncertainty of results. Results: The Markov model had a total of 11 outcomes, of which 7 were natural outcomes and 4 wereclinical intervention outcomes, and the goodness of fit was 0.969. The lifetime screening cost of TAAb+AFP strategy for HCC screening was 249 612 yuan/case, and the QALY per capita was 7.704 years. Compared with liver ultrasound +AFP strategy (247 805 yuan/case), the total health cost increased by 1 807 yuan/case, and the QALY obtained was 0.014. The ICER was 127 635 yuan /QALY. When the TAAb screening fee was higher than 889.552 yuan, or the discount rate was higher than 0.068, or the antiviral treatment compliance was lower than 45.1%, ICER > 212 676 yuan /QALY. When the single TAAb screening fee was 400-600 yuan, the TAAB+AFP strategy had cost effective value. When the willingness to pay was 70 892, 141 784 and 212 676 yuan /QALY, the probability of cost-effectiveness of TAAb+AFP strategy was 70.6%, 75.3% and 77.8%, respectively. Conclusion: It is cost-effective to use TAAb+AFP for early screening of liver cancer in Chinese population with CHB cirrhosis.

[Influence of correction degree on the clinical effect of valgus knee after total knee arthroplasty].

Objective: To investigate the influence of correction degree on the clinical effect of valgus knee after total knee arthroplasty(TKA). Methods: Clinical data of 91 patients with unilateral valgus knee who underwent TKA from January 2015 to December 2018 at Department of Orthopaedic Surgery,Zhongda Hospital,Southeast University were retrospectively analyzed. According to postoperative hip-knee-ankle angle(HKA),these patients were divided into neutral group (-3°≤HKA≤3°) and residual valgus group(HKA>3°). There were 70 patients in the neutral group,with a median age of 71.5 years(range:57 to 91 years),and 21 patients in the residual valgus group,with a median age of 71.5 years(range:60 to 85 years). The postoperative clinical indicators,including the range of motion (ROM),American Knee Society score(KSS),Western Ontario and McMaster University(WOMAC) osteoarthritis index,forgotten joint score (FJS-12) were collected. Meanwhile,the imaging indexes of femoral angle,tibial angle,femoral prosthesis flexion angle,tibial prosthesis posterior slope angle,patella tilt angle,congruence angle were also collected. Additionally,postoperative complications were recorded. The clinical data were analyzed by independent sample t test,Mann-Whitney U test or χ2 test. Results: There were no differences between the two groups in postoperative ROM (122.5°±8.5° vs. 119.4°±7.1°,t=1.534,P=0.128),KSS(159.8±8.9 vs. 150.0±8.9,t=-0.103,P=0.918),WOMAC osteoarthritis index(10.0(3.0) vs. 9.0(5.0),Z=-0.733,P=0.464),FJS-12(52.1(8.4) vs. 50.1(7.5),Z=-0.594,P=0.553)and femoral angle(94.0°(4.0°) vs. 94.0°(5.0°),Z=-0.209,P=0.835),tibial angle(90.0°(3.0°) vs. 91.0°(2.5°),Z=-1.226,P=0.220),femoral prosthesis flexion angle(3.0°(1.0°) vs. 3.0°(1.0°),Z=-0.652,P=0.514),tibial prosthesis posterior slope angle(4.0°(2.0°) vs. 4.0°(2.0°),Z=-0.763,P=0.445),patella tilt angle(9.0°(3.0°) vs. 9.0°(3.5°),Z=-1.429,P=0.153),congruence angle(14.0°(4.0°) vs. 15.0°(4.0°),Z=-1.690,P=0.091). However,abnormal proportions of patella tilt angle(33.3% vs.11.4%,χ²=5.630,P=0.018) and congruence angle(38.1% vs.17.1%,χ²=4.136,P=0.042) were apparent in the residual valgus group. The patients were follow-up for (32.1±5.2) months(range:24 to 40 months). Six weeks after operation,one case of joint stiffness occurred in the residual valgus group, which was improved after manual relaxation and rehabilitation exercises. At the last follow-up,two cases in the residual valgus group suffered patella instability which were fixed by patella braces and strengthening of the medial femoral muscles. There were no cases requiring reoperation for dislocation of patella,joint instability and aseptic loosening of the prosthesis in both groups. Conclusions: Residual valgus after TKA for valgus knee has no significant effect on the short-term clinical outcome,but it is more likely to cause abnormal proportions of patella tilt angle and congruence angle which may induce the risk of postoperative patella instability. The mid-and long-term outcomes need to be further investigated.

Identification of potential crucial genes associated with vasculogenic mimicry in human osteosarcoma based on gene expression profile.

We previously reported the presence of vasculogenic mimicry (VM) in human osteosarcoma. However, the mechanistic basis of osteosarcoma VM remains unclear. Three hundred eighty-one upregulated differentially expressed genes (DEGs) and 526 downregulated DEGs between human osteosarcoma cell line 143B and HOS cell exposed to Matrigel were screened out by microarray. GO categories such as "cell adhesion", "angiogenesis" were enriched in 143B group. PATHWAY analysis showed enriched TGF-beta, Wnt and VEGF signaling pathway in 143B group. The hub gene ITGA2 in signal-network of DEGs exhibited pro-VM and pro-metastasis effect. Our study provides fundamental data for further studies regarding molecules involved in osteosarcoma VM.

Population Structure and Genetic Diversity of Fungi Causing Rice Seedling Blight in Northeast China Based on Microsatellite Markers.

Rice seedling blight, which is caused by diverse pathogenic microorganisms, occurs worldwide and is the most important seedling disease affecting rice production in Northeast China. To further characterize the population structure and genetic diversity of the fungi responsible for rice seedling blight in Northeast China, 225 fungal strains were isolated from diseased rice seedlings collected from various rice-producing areas. The isolated strains included Fusarium oxysporum (48.0%), F. verticillioides (11.6%), F. tricinctum (8.0%), F. redolens (6.7%), F. equiseti (6.2%), F. solani (6.2%), Rhizoctonia solani (6.7%), Alternaria alternata (4.0%), and Curvularia coatesiae (2.7%). F. oxysporum was the dominant fungal species causing rice seedling blight, with most isolates exhibiting moderate pathogenicity. Moreover, to our knowledge, this is the first study to identify A. alternata and C. coatesiae as causal agents of rice seedling blight in Northeast China. None of the F. oxysporum isolates were sensitive to 10 µg/ml of carbendazim, implying that carbendazim is ineffective for controlling rice seedling blight in Northeast China. The F. oxysporum isolates were divided into nine groups based on a simple sequence repeat analysis involving 14 primer pairs. In addition, an analysis of molecular variance revealed a significant correlation between the F. oxysporum population and geographical location, which had a significant effect on the differentiation of the dominant isolate population. The results of this study provide insights into the genetic diversity of F. oxysporum strains causing rice seedling blight and may be useful for selecting isolates to screen for disease-resistant rice varieties, evaluating fungicide efficacy, and developing effective disease management strategies.

[Feasibility and perioperative safety of the combined procedure of catheter ablation and watchman left atrial appendage closure].

Objective: We aimed to explore the feasibility and perioperative safety of performing catheter ablation and left atrial appendage closure (LAAC) in a single (one-stop) session in patients with atrial fibrillation (AF). Methods: This study is an observational study. Consecutive AF patients who underwent the combined procedure of catheter ablation and LAAC with Watchman device of Xinhua Hospital in Shanghai between March 2017 and May 2019 were prospectively enrolled. Baseline, intra-and peri-procedural parameters were evaluated. Results: A total of 358 AF patients (189 males, (69.0±8.0) years) underwent the one-stop procedure. The CHA2DS2-VASc score was 3.2±1.5 and HAS-BLED score was 2.4±1.1, respectively in this patient cohort. Pulmonary vein isolation was achieved in all patients, while additional linear ablation was applied in 180 (50.3%) patients, yielding immediate success rate of 99.7%. Successful Watchman implantation was achieved in all patients. The perioperative serious adverse event occurred in 14 cases (3.9%). including 6 pericardial effusions (1.7%), 1 stroke (0.3%) and 5 vascular complications (1.4%), yielding procedure-related complication rate of 3.4%. In addition, 2 (0.6%) new-onset heart failures occurred postoperatively. There was no major bleeding or death during the perioperative period. Conclusions: Combined catheter ablation and LAAC can be successfully and safely performed in AF patients with high stroke risk. Follow-up data are needed to evaluate the outcome of this one-stop procedure.

Population structure and genetic diversity of Setosphaeria turcica from corn in Heilongjiang province, China.

AIM: The aims of this study were to identify races and mating types of Setosphaeria turcica causing northern corn leaf blight in Heilongjiang province of China and analyse the genetic diversity of S. turcica isolates using SSR markers. METHODS AND RESULTS: Based on gene-for-gene interactions, 13 races of S. turcica (races 0, 1, 2, 3, 12, 13, 23, 123, N, 1N, 12N, 3N and 23N) were isolated from infected corn plants in Heilongjiang province. Races 0 and 1 were the predominant races, and race 23N was identified for the first time in the region. Using two pairs of specific primers, three mating types, 'a', 'Aa' and 'A', were identified, with 'a' being the predominant mating type. SSR markers were used to analyse genetic diversity of 60 S. turcica isolates. Five SSR primers were polymorphic, which resulted in 45 reproducible bands with 2-15 bands for each primer. Cluster analysis separated the isolates into five groups at a similarity coefficient of 0·84. Analysis of molecular variance showed that there was significant correlation between SSR groups and mating type of the isolates. No significant correlation was found between SSR groups and physiological races or geographical location of the isolates. CONCLUSIONS: The work reported that races 0 and 1 were the predominant races, and race 23N was identified for the first time in Heilongjiang province with 'a' being the predominant mating type. There was significant correlation between SSR groups and mating type of S. turcica isolates. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results provide information on population structure and genetic diversity of S. turcica causing Northern corn leaf blight, which will facilitate the development of effective disease management programs.

Simultaneous non-contrast angiography and intraplaque haemorrhage (SNAP) imaging for cervical artery dissections.

AIM: To evaluate the feasibility of high-resolution magnetic resonance imaging (MRI) with a simultaneous non-contrast angiography and intraplaque haemorrhage (SNAP) sequence in identifying cervical artery dissections (CeAD). MATERIALS AND METHODS: Fifty-three patients with suspected CeAD underwent the SNAP sequence (including non-contrast magnetic resonance angiography [MRA] and heavy T1-weighting vessel wall images simultaneously in a single scan) and conventional MRI sequences (including three-dimensional [3D] time-of-flight MRA and T1-weighted black-blood imaging [T1W BB]) and cervical vascular ultrasound (CVUS). In diagnosis of CeAD, the diagnostic sensitivity and specificity of SNAP, and the diagnostic coherence between SNAP and conventional sequences and between SNAP and CVUS was analysed. At follow-up, the absolute signal (AS) and signal index (SI) of the intramural haematoma (IMH) between vessel wall images on SNAP and T1W-BB images were compared. The image quality of SNAP was analysed by comparing the signal-to-noise ratio (SNR) between vessel wall images from the SNAP and T1W-BB sequences. RESULTS: The SNAP sequence was found to provide good performance in the diagnosis of CeAD (sensitivity 72.2%, specificity 98.2%); good agreement was found between SNAP and conventional sequences (Cohen's κ=0.76, p<0.05); and excellent agreement was found between SNAP and CVUS (Cohen's κ=0.83, p<0.05). There was no significant difference between AS or SI of the IMH of the vessel wall images within the SNAP and T1W-BB sequences during the review. The SNAP sequence had higher SNR of the IMH compared to T1W-BB, T2W-BB, proton-density-weighted volume isotropic turbo-spin-echo acquisition imaging (PD-VISTA) sequences (p<0.05). CONCLUSION: The SNAP sequence holds the potential to be preferred choice for screening of patients with a high suspicion of CeAD and for the follow-up of IMH after treatment.

[Effect of acid etching of retropreparation cavities on seal of retrofill materials].

OBJECTIVE: To evaluate the effect of acid etching of retropreps on seal of different retrofill materials. METHODS: In the study, 80 freshly extracted lower molar teeth were used. They were examined under 3.5× magnifying glass to rull out fractures. They were cleaned and stored in distilled water before use. The distal roots were sectioned off and underwent root canal treatment. Rotary nickel-titanium instruments were used during instrumentation and the roots were obturated using lateral condensation technique. The apical portion (3 mm in length) was removed with a fine grit diamond bur, the root tip was retroprepared with a ultrasonic tip (3 mm in depth). The retroprepared roots were randomly assigned to 4 groups and retrofilled with amalgam, intermediate restorative material (IRM), iRoot BP Plus and mineral trioxide aggregate (MTA). The groups were further divided into subgroups according to treatment of the root end cavity (etch and non-etch). The root tips were covered with alginate impression material and were left to set in PBS solution for a week and stained with methylene blue for a week. The roots were removed from the dye solution, thoroughly rinsed and dried, split in halves along the long axis with a diamond disk and observed under a stereoscope. The linear dye leakage was measured and analyzed. One way ANOVA and Tamhane's T2 method were used to analyze the data. The significance level was set at 0.05. RESULTS: The dye leakage results (mean±standard deviation) according to the treatment groups were: amalgam etch (2.80±0.72) mm, amalgam non-etch (2.07±0.86) mm, IRM etch (1.54±0.19) mm, IRM non-etch (1.12±0.28) mm , iRoot BP Plus etch (0.20±0.20) mm, iRoot BP Plus non-etch (0.11±0.08) mm, MTA etch (0.19±0.19) mm, and MTA non-etch (0.17±0.14) mm. One way ANOVA showed significant differences between the groups. Comparison between the groups using Tamhane's T2 method showed roots retrofilled with iRoot BP Plus and MTA had significant less leakage than those retrofilled with amalgam and IRM (P<0.05); There was no significant difference in terms of leakage between iRoot BP Plus and MTA; Acid etching increased leakage of IRM but did not affect MTA, iRoot BP Plus or amalgam retrofillings. CONCLUSION: Acid etching is not shown to benefit apical sealing of retrofill materials.

[HBsAg loss with Pegylated-interferon alfa-2a in hepatitis B patients with partial response to nucleos(t)-ide analog: new switch study].

Objective: Hepatitis B surface antigen (HBsAg) loss is seldom achieved with nucleos(t)ide analog (NA) therapy in chronic hepatitis B patients but may be enhanced by switching to finite pegylated-interferon (Peg-IFN) alfa-2a. We assessed HBsAg loss with 48- and 96-week Peg-IFN alfa-2a in chronic hepatitis B patients with partial response to a previous NA. Methods: Hepatitis B e antigen (HBeAg)-positive patients who achieved HBeAg loss and hepatitis B virus DNA < 200 IU/mL with previous adefovir, lamivudine or entecavir treatment were randomized 1:1 to receive Peg-IFN alfa-2a for 48 (n = 153) or 96 weeks (n = 150). The primary endpoint of this study was HBsAg loss at end of treatment. The ClinicalTrials.gov identifier is NCT01464281. Results: At the end of 48 and 96 weeks' treatment, 14.4% (22/153) and 20.7% (31/150) of patients, respectively, who switched from NA to Peg-IFN alfa-2a cleared HBsAg. Rates were similar irrespective of prior NA or baseline HBeAg seroconversion. Among those who cleared HBsAg by the end of 48 and 96 weeks' treatment, 77.8% (14/18) and 71.4% (20/28), respectively, sustained HBsAg loss for a further 48 weeks. Baseline HBsAg < 1 500 IU/mL and week 24 HBsAg < 200 IU/mL were associated with the highest rates of HBsAg loss at the end of both 48- and 96-week treatment (51.4% and 58.7%, respectively). Importantly, extending treatment from 48 to 96 weeks enabled 48.3% (14/29) more patients to achieve HBsAg loss. Conclusion: Patients on long-term NA who are unlikely to meet therapeutic goals can achieve high rates of HBsAg loss by switching to Peg-IFN alfa-2a. HBsAg loss rates may be improved for some patients by extending treatment from 48 to 96 weeks, although the differences in our study cohort were not statistically significant. Baseline and on-treatment HBsAg may predict HBsAg loss with Peg-IFN alfa-2a.

[Study on the metastatic sequence of cervix lymph node in hypopharyngeal carcinoma].

Objective: To investigate the metastatic sequence of cervical lymph node in hypopharyngeal carcinoma aimed at guiding neck exploration. Methods: Seventy-five serial sections of integrally dissected lateral neck specimens from 67 patients of hypophayryngeal carcinoma were histopathologically observed, and the metastatic sequence of cervical lymph node of hypophayryngeal carcinoma were analysed. Results: In 75 integrally dissected lateral neck specimens, 63 laterals were found to occur cervical lymph node metastases, the metastatic ratio was 84.0%. The analytic result of 63 dissected lateral neck specimens with positive lymph nodes showed that the metastatic lymph node ratio in descending order was level Ⅱ (90.5%), level Ⅲ (76.2%), level Ⅳ (41.3%), level Ⅴ (15.9%), level Ⅰ (7.9%) and level Ⅵ (3.2%). The metastatic ratio of lymph node between level Ⅰ~Ⅵ were significantly different from each other (P<0.01). When the tumor metastasized to one cervical lymph node, this could be found in levels Ⅱ or Ⅲ, when metastasized to two cervical lymph nodes, these could be found in levels Ⅱ, Ⅲ, Ⅳ, and when metastasized to more than 5 of cervical lymph nodes, these could be found in levels Ⅱ, Ⅲ, Ⅳ, Ⅴ, Ⅰand Ⅵ. According to the occurring sequence, metastatic ratio and number of cervical lymph node metastasis (LNM), levels Ⅱ and Ⅲ were identified as the first station, level Ⅳ was the second station and levels Ⅴ, Ⅰ and Ⅵ were the third station of cervical LNM in hypopharyngeal carcinoma. Conclusion: The confirmation of metastatic sequence of cervical lymph node in hypophayryngeal carcinoma provides a reliable evidence for neck lymph node dissection and reference value for clinic therapy.

[Biomechanical effects on adjacent segments of different growing-rod fixation in early onset scoliosis].

Objective: To analyse the biomechanical effects on adjacent segments of different growing-rod (GR) fixation in early onset scoliosis through a finite element analysis method. Methods: A severe early-onset scoliosis patient was selected and the pre-operation and post-GR-operation (Upper instrumented levels: T(4), T(5). Lower instrumented levels: L(3), L(4)) whole spine 3-dimentional CT scan data were collected to build the finite models. Based on the different models, biomechanical differences on adjacent segments were analysed. Results: The stress on the adjacent structures decreased after the GR surgery compared with the pre-operation. Compared with the single GR, stress on T(3) vertebrae decreased by 6.2%, stress on T(3/4) disc decreased by 6.7%, stress on T(3/4) ligament decreased by 27.7%, stress on T(6) vertebrae decreased by 16.9%, stress on T(5/6) disc decreased by 1.2%, stress on T(5/6) ligament decreased by 40.4%, stress on L(2) vertebrae decreased by 32.6%, stress on L(2/3) disc decreased by 30%, stress on L(2/3) ligament decreased by 15.6%, stress on L(5) vertebrae decreased by 1.2%, stress on L(4/5) disc decreased by 15.7%, stress on L(4/5) ligament decreased by 100.0% in dual GR structure. The application of hook (s) on the upper instrumented vertebrae (s) decreased the stress on the cranial adjacent segment. Stress on T(3) vertebrae decreased by 2.8% and 2.2%, stress on T(3/4) disc decreased by 2.4% and 1.5%, stress on T(3/4) ligament decreased by 3.6% and 5.7% in single GR and dual GR models separately when the hook (s) were utilized. In the meanwhile, the stress on the adjacent segment was more concentrated in the single GR model. Conclusion: Dual-rod growing-rod and the application of hook (s) on the upper instrumented vertebrae could reduce the stress on the adjacent segments more effectively in patients with early onset scoliosis.

[Process of the degradation in vivo and biosafety of biodegradable magnesium alloy stent].

Objective: To observe the degradation process of biodegradable magnesium alloy stent (BMAS) in vivo in order to evaluate its degradation time and biological safety. Methods: Twenty-four male New Zealand white rabbits were divided into two groups: group A (n=12) and group B (n=12). The BMAS (a total of 12) was implanted in the infrarenal aorta of each rabbit in group A, while group B was the control group, without treatment. Color Doppler ultrasound was used at the 1, 2, 3, 4 months postoperatively to observe the degradation process of stents in group A. The arterial blood samples and main organs of two groups were also collected for biochemical examination and biosafety. Degradation assessment included transmission X-ray tomography (XRT), scanning electron microscope (SEM) and energy dispersion spectrum (EDS). Results: The XRT showed that the morphology of the stent was basically intact at 1 month after implantation, then scaffold composites were gradually degraded and absorbed. Degradation was basically completed at 4 months after operation. The early degradation products were Mg(2+) , then gradually replaced by Ca(2+) , P and other inorganic composition. There was no obvious adverse reactions in group A during the 4 months follow-up period. There was no statistical difference between the two groups in blood biochemical and pathological results (all P>0.05). Conclusion: BMAS can be degraded within 4 months in the abdominal aorta of rabbit, and the main degradation products are Ca(2+) and P, with good biosafety.

Observation of Double Impurity Critical Gradients for Electromagnetic Turbulence Excitation in Tokamak Plasmas.

The impact of impurity ions on a pedestal has been investigated in the HL-2A Tokamak, at the Southwestern Institute of Physics, Chengdu, China. Experimental results have clearly shown that during the H-mode phase, an electromagnetic turbulence was excited in the edge plasma region, where the impurity ions exhibited a peaked profile. It has been found that double impurity critical gradients are responsible for triggering the turbulence. Strong stiffness of the impurity profile has been observed during cyclic transitions between the I-phase and H-mode regime. The results suggest that the underlying physics of the self-regulated edge impurity profile offers the possibility for an active control of the pedestal dynamics via pedestal turbulence.

Effects of carbomer eye drops in combination with orthokeratology lens in treating adolescent myopia.

To investigate the effects of carbomer eye drops (CED) during long-time wearing of overnight orthokeratology lens of adolescents with myopia, 260 teenagers with myopia treated in the Henan Provincial People’s Hospital from June 2012 to August 2014 and followed-up for more than 2 years were enrolled. All the patients underwent regular fitting of orthokeratology lens. They were divided into a CED (Vidisic) group (130 cases, 260 eyes treated with CED) and rewetting drops (RD) (Baushe and Lomb) group (130 cases, 260 eyes treated with RD). The effects in the two groups were observed. The incidence of corneal epithelial defects one day, one week and one month after treatment of the CED group was lower than that of the RD group, and the difference was statistically significant (P less than 0.05); the tear break up time (TBUT) of the CED group was higher than that of the RD group at different time points, and the difference had statistical significance (P less than 0.05); the difference of the value of Schirmer I test between the two groups had no statistical significance (P>0.05). It is concluded that carbomer eye drops can stabilize tear film and protect and repair corneal epithelium during the wearing of orthokeratology lens.