Perinatal and neurodevelopmental outcome in complicated monochorionic pregnancy after selective fetal reduction: radiofrequency ablation vs microwave ablation

OBJECTIVES

To summarize our experience in the application of radiofrequency ablation (RFA) and microwave ablation (MWA) for selective fetal reduction in complicated monochorionic pregnancies and compare the perinatal outcome of the two techniques.

METHODS

This was a retrospective study of data from a consecutive cohort of all monochorionic twin pregnancies that underwent selective fetal reduction with RFA or MWA at Peking University Third Hospital, Beijing, China from January 2012 to December 2018. All surviving cotwins were followed up to assess their neurodevelopment using the Age & Stage Questionnaire, Chinese version. Perinatal and neurodevelopmental outcomes were compared between the RFA and MWA groups. We also fitted multivariable models to test the association between procedure-related factors and the main perinatal outcomes, including preterm birth (PTB) < 37 weeks' gestation, intrauterine fetal death (IUFD) of the cotwin, adverse outcome (defined as occurrence of IUFD of the cotwin, termination of pregnancy or PTB < 28 weeks) and overall survival.

RESULTS

In total, 45 cases (42 twin and three triplet pregnancies) underwent RFA and 126 cases (105 twin and 21 triplet pregnancies) underwent MWA. The overall survival rates in monochorionic diamniotic twin pregnancies were similar between the RFA and MWA groups (61.0% vs 67.0%; P = 0.494). However, pregnancies whose indication for fetal reduction was selective intrauterine growth restriction or twin reversed arterial perfusion had higher overall survival rates (75.5% and 82.6%, respectively) compared with those in other indication groups. A total of 104 children were followed up (20 in the RFA group and 84 in the MWA group); four (20.0%) and eight (9.5%) children were assessed as having overall developmental delay in the RFA and MWA groups, respectively, with no significant difference between the two groups. Multivariable analyses showed that procedure indication, number of ablation cycles and gestational age at procedure were associated significantly with the main perinatal outcomes.

CONCLUSIONS

RFA and MWA for selective fetal reduction in complicated monochorionic pregnancies can achieve similar overall survival rate and neurodevelopmental outcome, but MWA is associated with a lower risk of preterm birth. Moreover, procedure-related factors are associated significantly with perinatal outcome. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Logistic regression analysis of risk factors for intra-abdominal hypertension after giant ventral hernia repair: a retrospective cohort study

BACKGROUND

Intra-abdominal hypertension (IAH) is a classical complication after giant ventral hernia surgery and may lead to abdominal compartment syndrome (ACS). Assessment of risk factors and prevention of IAH/ACS are essential for hernia surgeons.

METHODS

We performed a retrospective study including 58 giant ventral hernia patients in our center between Jan 1, 2017, and Mar 1, 2022, we recorded age, gender, chronic obstructive pulmonary disease (COPD), coronary heart disease (CHD), hypertension, type 2 diabetes mellitus (T2DM), hypoproteinemia, body mass index (BMI), the ratio of hernia sac volume to abdominal cavity volume (HSV/ACV), defect width, tension reduction procedure (TRP), positive fluid balance (PFB) and IAH of these patients and analyzed the data using univariate and multivariate logistic regression to screen the risk factors for IAH after surgery.

RESULTS

The multivariate analysis showed that HSV/ACV ≥ 25%, hypoproteinemia, and PFB were independent risk factors for the occurrence of IAH after giant ventral hernia repair (P = 0.025, 0.016, 0.017, respectively). We did not find any correlation between postoperative IAH and the patient's age, gender, COPD, CHD, hypertension, T2DM, BMI, defect width, TRP, and PFB.

CONCLUSION

Identifying risk factors is of great significance for the early identification and prevention of IAH/ACS. We found that HSV/ACV ≥ 25%, hypoproteinemia, and PFB were independent risk factors for IAH after giant ventral hernia repair.

Ambient PM2.5 exposures and systemic inflammation in women with early pregnancy

The association between ambient fine particulate matter (PM_2.5) and systemic inflammation in women with early pregnancy is unclear. This study estimated the effects of PM_2.5 exposures on inflammatory biomarkers in women with normal early pregnancy (NEP) or clinically recognized early pregnancy loss (CREPL). Serum interleukin-1beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were measured in 228 early pregnant women recruited in Tianjin, China. Maternal PM_2.5 exposures at lag 0 through lag 30 before blood collection were estimated using temporally-adjusted land use regression models. Daily exposures to ambient PM₁₀, NO₂, SO₂, CO and 8-hours maximum ozone were estimated using city-level concentrations. Single-day lag effects at lag 0 through lag 7 were estimated using multivariable linear regression models. Distributed lag effects and cumulative effects over the preceding seven days and 30 days were estimated using distributed lag non-linear models. Serum IL-1β (8.0% increase at lag 3), IL-6 (33.9% increase at lag 5) and TNF-α (12.7% increase at lag 5) in early pregnant women were significantly increased with an interquartile range increase in PM_2.5 exposures adjusted for temporal confounders and demographic characteristics. These effects were robust in several two-pollutant models. Distributed lag effects over the preceding 30 days also showed that the three cytokines were significantly increased with PM_2.5 on some lag days. Among all cumulative effects of PM_2.5 on the three cytokines in all subjects or in the two groups, only IL-6 was significantly increased in CREPL women over the preceding seven days and 30 days. No significant cumulative effect of PM_2.5 was observed in NEP women. In conclusion, exposure to ambient PM_2.5 may induce systemic inflammation in women in the first trimester of pregnancy. Whether the PM_2.5-related cumulative increase in maternal IL-6 is involved in the pathogenic mechanisms of early pregnancy loss needs to be identified in future research.

rocF affects the production of tetramethylpyrazine in fermented soybeans with Bacillus subtilis BJ3-2

BACKGROUND

Tetramethylpyrazine (TTMP) is a flavoring additive that significantly contributes to the formation of flavor compounds in soybean-based fermented foods. Over recent years, the application of TTMP in the food industry and medicine has been widely investigated. In addition, several methods for the industrial-scale production of TTMP, including chemical and biological synthesis, have been proposed. However, there have been few reports on the synthesis of TTMP through amino acid metabolic flux. In this study, we investigated genetic alterations of arginine metabolic flux in solid-state fermentation (SSF) of soybeans with Bacillus subtilis (B.subtilis) BJ3-2 to enhance the TTMP yield.

RESULTS

SSF of soybeans with BJ3-2 exhibited a strong Chi-flavour (a special flavour of ammonia-containing smelly distinct from natto) at 37 °C and a prominent soy sauce-like aroma at 45 °C. Transcriptome sequencing and RT-qPCR verification showed that the rocF gene was highly expressed at 45 °C but not at 37 °C. Moreover, the fermented soybeans with BJ3-2ΔrocF (a rocF knockout strain in B. subtilis BJ3-2 were obtained by homologous recombination) at 45 °C for 72 h displayed a lighter color and a slightly decreased pH, while exhibiting a higher arginine content (increased by 14%) than that of BJ3-2. However, the ammonia content of fermented soybeans with BJ3-2ΔrocF was 43% lower than that of BJ3-2. Inversely, the NH4+ content in fermented soybeans with BJ3-2ΔrocF was increased by 28% (0.410 mg/kg). Notably, the TTMP content in fermented soybeans with BJ3-2ΔrocF and BJ3-2ΔrocF + Arg (treated with 0.05% arginine) were significantly increased by 8.6% (0.4617 mg/g) and 18.58% (0.504 mg/g) respectively than that of the BJ3-2.

CONCLUSION

The present study provides valuable information for understanding the underlying mechanism during the TTMP formation process through arginine metabolic flux.

Quantitative Collateral Assessment on CTP in the Prediction of Stroke Etiology

BACKGROUND AND PURPOSE

Patients with stroke etiology of large-artery atherosclerosis were thought to have better collateral circulation compared with patients with other stroke etiologies. We aimed to investigate the association between stroke etiology and collateral circulation with a new quantitative collateral assessment method.

MATERIALS AND METHODS

This retrospective study reviewed data from consecutive patients with proximal anterior artery occlusion who underwent CTP before reperfusion therapy. CBF maps were derived from CTP. A new indicator, maximum CBF of collateral vessels within the Sylvian fissure (cCBF_max), was applied to quantitatively assess the collateral status. The relationship between collateral status and stroke etiology was investigated.

RESULTS

A total of 296 patients were finally analyzed. The median cCBF_max was significantly higher in patients with large-artery atherosclerosis than in those without it (92 [interquartile range, 65-123] mL/100 g/min versus 62 [interquartile range, 46-82] mL/100 g/min; P < .001). Multivariable analysis revealed that a higher cCBF_max score was independently associated with large-artery atherosclerosis etiology (OR, 1.010; 95% CI, 1.002-1.018; P = .017) after adjustment. The area under the curve, sensitivity, and specificity of the final model in predicting the etiology of large-artery atherosclerosis were 0.870, 89.7%, and 75.2%, respectively.

CONCLUSIONS

Patients with large-artery atherosclerosis had a more adequate collateral perfusion supply with the new quantitative collateral assessment. The new quantitative collateral measurement might contribute to the prediction of stroke etiology in the acute clinical scenario for patients with acute ischemic stroke.

Effects of pre-operative enteral immunonutrition for esophageal cancer patients treated with neoadjuvant chemoradiotherapy: protocol for a multicenter randomized controlled trial (point trial, pre-operative immunonutrition therapy)

BACKGROUND

Neoadjuvant chemoradiation followed by esophagectomy has been established as the first-line treatment for locally advanced esophageal cancer. Postoperative enteral nutrition has been widely used to improve perioperative outcomes. However, whether to implement preoperative nutritional intervention during neoadjuvant therapy is yet to be verified by prospective studies.

METHODS

POINT trial is a multicenter, open-labeled, randomized controlled trial. A total of 244 patients with surgically resectable esophageal cancer are randomly assigned to nutritional therapy group (arm A) or control group (arm B) with a 2:1 ratio. Both groups receive neoadjuvant chemotherapy with concurrent radiotherapy based on the CROSS regimen followed by minimally invasive esophagectomy. The primary endpoint is the rate of nutrition and immune-related complications after surgery. Secondary endpoints include completion rate of neoadjuvant chemoradiation and related adverse events, rate of pathological complete response, perioperative outcomes, nutritional status, overall survival, progression-free survival and quality of life.

DISCUSSION

This trial aims to verify whether immunonutrition during neoadjuvant chemoradiation can reduce the rate of complications and improve perioperative outcomes. Frequent communication and monitoring are essential for a multicenter investigator-initiated trial.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04513418. The trial was prospectively registered on 14 August 2020, https://www.

CLINICALTRIALS

gov/ct2/show/NCT04513418 .

Gadolinium deposition in the brain is related to various contrast agents: a matched case-control study

AIM

To assess the relationship between gadolinium deposition in the brain and various gadolinium-based contrast agents (GBCAs) and to explore confounding variables.

METHODS

The study group included 87 patients with multiple enhanced brain magnetic resonance imaging (MRI) examinations of which 48 patients were in the linear GBCA group (33 patients in gadopentetate dimeglumine group and 15 patients in gadobenate dimeglumine group) and 39 patients in the macrocyclic GBCA group (22 patients in gadobutrol group and 17 patients in gadoterate meglumine group). The control group included 87 normal participants who were matched regarding age, sex, MRI machine and imaging sequences to the study cohort. T1 signal intensity (SI) ratios of the dentate nucleus to the pons (DN/pons) and of the globus pallidus to the frontal white matter (GP/FWM) in both groups were calculated and compared. The relationships between SI ratios and confounding variables were analysed.

RESULTS

Significant differences were detected between two linear GBCA groups and control groups in T1 SI ratios of the DN/pons and GP/FWM (all p<0.001). There were no differences for two the macrocyclic GBCA groups compared with matching control groups (all p>0.05). T1 SI ratios of the linear GBCA group were significantly higher than those of the macrocyclic GBCA group (p<0.001). In the linear GBCA group, the T1 SI ratios of the DN/pons correlated moderately positively with the number of GBCA administrations (r=0.643, p<0.001), and MRI machine and sequence used.

CONCLUSIONS

Increased T1 SI could be observed after repeated administrations of linear GBCA. T1 SI of the DN correlated with the number of linear GBCA administrations, and detection might be affected by MRI machine and sequence.

Application of machine learning approaches to predict the 5-year survival status of patients with esophageal cancer

Background

Accurate prognostic estimation for esophageal cancer (EC) patients plays an important role in the process of clinical decision-making. The objective of this study was to develop an effective model to predict the 5-year survival status of EC patients using machine learning (ML) algorithms.

Methods

We retrieved the information of patients diagnosed with EC between 2010 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) Program, including 24 features. A total of 8 ML models were applied to the selected dataset to classify the EC patients in terms of 5-year survival status, including 3 newly developed gradient boosting models (GBM), XGBoost, CatBoost, and LightGBM, 2 commonly used tree-based models, gradient boosting decision trees (GBDT) and random forest (RF), and 3 other ML models, artificial neural networks (ANN), naive Bayes (NB), and support vector machines (SVM). A 5-fold cross-validation was used in model performance measurement.

Results

After excluding records with missing data, the final study population comprised 10,588 patients. Feature selection was conducted based on the χ² test, however, the experiment results showed that the complete dataset provided better prediction of outcomes than the dataset with removal of non-significant features. Among the 8 models, XGBoost had the best performance [area under the receiver operating characteristic (ROC) curve (AUC): 0.852 for XGBoost, 0.849 for CatBoost, 0.850 for LightGBM, 0.846 for GBDT, 0.838 for RF, 0.844 for ANN, 0.833 for NB, and 0.789 for SVM]. The accuracy and logistic loss of XGBoost were 0.875 and 0.301, respectively, which were also the best performances. In the XGBoost model, the SHapley Additive exPlanations (SHAP) value was calculated and the result indicated that the four features: reason no cancer-directed surgery, Surg Prim Site, age, and stage group had the greatest impact on predicting the outcomes.

Conclusions

The XGBoost model and the complete dataset can be used to construct an accurate prognostic model for patients diagnosed with EC which may be applicable in clinical practice in the future.

[Application of machine learning in orthodontics]

With the increasing integration of artificial intelligence (AI) with other fields, machine learning, one of the major methods in AI, has been extensively applied in dentistry in the stage of diagnosis, therapy and prognosis evaluation. Nowadays, numerous studies have reported the applications of machine learning in orthodontics in two major aspects, including image identification and clinical decision support system. Herein, we reviewed the application progress of machine learning in orthodontics in order to provide new insight for the future precision medicine.

Atomistic modelling of the immiscible Fe-Bi system from a constructed bond order potential

An analytical bond-order potential (BOP) of Fe-Bi has been constructed and has been validated to have a better performance than the Fe-Bi potentials already published in the literature. Molecular dynamics simulations based on this BOP has been then conducted to investigate the ground-state properties of Bi, structural stability of the Fe-Bi binary system, and the effect of Bi on mechanical properties of BCC Fe. It is found that the present BOP could accurately predict the ground-state A7 structure of Bi and its structural parameters, and that a uniform amorphous structure of Fe_100-xBi_xcould be formed when Bi is located in the composition range of 26 ⩽x< 70. In addition, simulations also reveal that the addition of a very small percentage of Bi would cause a considerable decrease of tensile strength and critical strain of BCC Fe upon uniaxial tensile loading. The obtained results are in nice agreement with similar experimental observations in the literature.

[Changes in the related indicators of bone formation and bone resorption in severely burned rats]

Objective: To observe the changes in the related indicators of bone formation and bone resorption in severely burned rats. Methods: The experimental research method was adopted. Thirty female Sprague-Dawley rats aged 6 to 8 weeks were divided into sham injury group, 12% total body surface area (TBSA) full-thickness burn group, and 24%TBSA full-thickness burn group according to the random number table, with 10 rats in each group. The rats were treated on the back correspondingly, after which, the burned rats were rehydrated by intraperitoneal injection according to the Parkland formula, and the wound was coated with 20 g/L iodophor until wound healing. On post injury day (PID) 28, the tibia tissue of rats in each group was collected. The new bone tissue and the number of osteoclasts were observed after staining with Masson and tartrate-resistant acid phosphatase, respectively. The abdominal aortic blood of rats in each group was harvested for serum preparation. The bone metabolism indexes of serum calcium ion and phosphorus ion concentration were determined by the methyl thymol blue colorimetric method and phosphomolybdic acid method, respectively. The serum levels of bone formation marker of aminoterminal propeptide of type 1 procollagen (P1NP) and bone resorption marker of beta-carboxy-terminated peptide of type Ⅰ collagen (β-CTX) were determined by enzyme-linked immunosorbent assay. The first lumbar spine tissue of rats in each group was collected, and the mRNA expression levels of osteoprotegerin, receptor activator of nuclear factor-κB ligand (RANKL), tumor necrosis factor receptor-associated factor 6 (TRAF-6), nuclear factor of activated T cell 1 (NFATC1), c-Fos, and c-Src were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with one-way analysis of variance, Bonferroni method, Welch test, Games-Howell test, Kruskal-Wallis test, Mann-Whitney U test, and Bonferroni correction. Results: On PID 28, compared with that in sham injury group, the formation of new bone tissue in the tibia tissue of rats in the two burn groups was decreased, and the larger the burn area, the more obvious the decrease. The numbers of osteoclasts in the tibia tissue of rats in the two burn groups were similar, both significantly more than the number in sham injury group. On PID 28, the serum calcium ion concentration and serum level of β-CTX of rats in the three groups were similar (P>0.05). The serum phosphorus ion concentration of rats in 24%TBSA full-thickness burn group was significantly higher than that in 12%TBSA full-thickness burn group (P<0.05), and the serum phosphorus ion concentrations in the two burn groups were significantly higher than the concentration in sham injury group (P<0.01). The serum level of P1NP of rats in 24%TBSA full-thickness burn group was significantly lower than that in sham injury group (P<0.01). On PID 28, the mRNA expression levels of osteoprotegerin in the first lumbar spine tissue of rats in sham injury group, 12%TBSA full-thickness burn group, and 24%TBSA full-thickness burn group were 1.01±0.20, 1.71±0.83, and 2.24±0.51, respectively, and that in 24%TBSA full-thickness burn group was significantly higher than that in sham injury group (P<0.01). The mRNA expression level of RANKL in the first lumbar spine tissue of rats in 24%TBSA full-thickness burn group was 1.31±0.17, which was significantly higher than 1.00±0.14 in sham injury group and 0.97±0.10 in 12%TBSA full-thickness burn group (P<0.01). The mRNA expression levels of TRAF-6, NFATC1 (Z=3.141, 3.782), and c-Src in the first lumbar tissue of rats in 12%TBSA full-thickness burn group and 24%TBSA full-thickness burn group and the mRNA expression level of c-Fos in the first lumbar tissue of rats in 12%TBSA full-thickness burn group were significantly higher than those in sham injury group (P<0.05 or P<0.01). The mRNA expression levels of c-Fos and c-Src in the first lumbar spine tissue of rats in 12%TBSA full-thickness burn group were significantly higher than those in 24%TBSA full-thickness burn group (P<0.01). Conclusions: Severe burns can cause a decrease in the generation of new bone tissue, an increase in the number of osteoclasts and the serum phosphorus ion concentration, and a decrease in the serum level of P1NP in rats. The level of osteoprotegerin, RANKL, TRAF-6, NFATC1, c-Fos, and c-Src in bone tissue showed an increasing trend while the level of NFATC1, c-Fos, and c-Src showed a decreasing trend with the increase of burn area.

P–129 Follicular extracellular vesicles of women with polycystic ovarian syndrome inhibit oocyte maturation

Study question

Does follicular extracellular vesicles of women with polycystic ovarian syndrome (PCOS-EVs) interfere with the quality of oocytes?

Summary answer

PCOS-EVs induced oxidative stress in the oocytes and inhibited oocyte maturation by increasing the abnormal mitochondria distribution and abnormal spindle rates.

What is known already

Polycystic ovarian syndrome (PCOS) is a common endocrine disorder in women of reproductive age, with a prevalence up to 10%. Women with PCOS are characterized by a clustering of features, including hyperandrogenism, polycystic ovarian morphology, and notably, anovulation. Although international guidelines recommend assisted reproduction techniques to be an effective resort for PCOS patients to conceive. However, even after overcoming ovulatory dysfunction via ovulation induction, the pregnancy outcomes of patients with PCOS were far from satisfying with lower fertilization, cleavage, and implantation rates, implicating that theoocyte quality of these patients are affected. Whereas the mechanisms have not been elucidated yet.

Study design, size, duration

Follicular fluid of PCOS patients (n = 10) and healthy controls (n = 10) were collected and used for extracellular vesicles (EVs) isolation via ultracentrifugation. Germinal vesicle (GV) oocytes collected from female ICR mice were cocultured with RIF-EVs or FER-EVs, respectively, and PBS served as a blank control. GV breakdown (GVBD) rate and maturation rate were calculated at two-hour and fourteen-hour of co-culture, respectively. Besides, oocyte mitochondria distribution, meiosis spindle morphology, and oxidative status were assessed in different groups.

Participants/materials, setting, methods

EVs were determined by western blotting, nanoparticle tracking analysis, and transmission electron microscopy. Fluorescence labeled EVs were used to visualize internalization by oocytes. Oocytes mitochondria and mitosis spindles were stained with fluorescence, and abnormal mitochondria rate or abnormal spindle rate was calculated. Reactive oxygen species (ROS) level was detected in the differently treated oocytes. Moreover, the expression of CAT, GSS, and SOD was determined in the oocytes using quantitative reverse transcription polymerase chain reaction.

Main results and the role of chance

Both PCOS-EVs and CTRL-EVs are bilayered vesicles, ranging from 100 to 150 nm, and enriched in Alix, TSG101, and CD9. EVs could be internalized by oocytes within one hour. After coculture, the GVBD rate was similar among the three groups; whereas the maturation rate was significantly decreased in the PCOS-EV group compared with CTRL-EV group or PBS group. In addition, the abnormal mitochondria distribution rate or abnormal spindle rate were significantly increased in the PCOS-EV group compared with PBS or CTRL-EV group. The ROS level was increased in the PCOS-EV group compared with CTRL-EV group, and the expression of CAT, GSS, and SOD was increased in the PCOS-EV-treated oocytes.

Limitations, reasons for caution

Our study did not identify the contents of PCOS-EVs and CTRL-EVs, and the molecular mechanisms of dysregulations induced by PCOS-EVs need further researches to investigate.

Wider implications of the findings: This work confirmed that EV-conducted cellular communication played an important role in oocyte development in women with PCOS. The dysregulation of oocytes induced by PCOS-EVs might be related to the poor oocyte quality of women with PCOS, which may provide a novel target to improve pregnancy outcomes of these patients.

Trial registration number

Not applicable

FOXO3 Mediates Tooth Movement by Regulating Force-Induced Osteogenesis

The high prevalence of malocclusion and dentofacial malformations means that the demand for orthodontic treatments has been increasing rapidly. As the biological basis of orthodontic treatment, the mechanism of mechanical force-induced alveolar bone remodeling during orthodontic tooth movement (OTM) has become the key scientific issue of orthodontics. It has been demonstrated that bone mesenchymal stem cells (BMSCs) are crucial for bone remodeling and exhibit mechanical sensing properties. Mechanical force can promote osteoblastic differentiation of BMSCs and osteogenesis, but the key factor that mediates mechanical force-induced osteogenesis during OTM remains unclear. In this study, by performing reverse-phase protein arrays on BMSCs exposed to mechanical force, we found that the expression level of forkhead box O3 (FOXO3) was significantly upregulated during the mechanical force-induced osteoblastic differentiation of BMSCs. The number of FOXO3-positive cells was consistently higher on the OTM side as compared with the control side and accompanied by the enhancement of osteogenesis. Remarkably, inhibiting FOXO3 with repaglinide delayed OTM by severely impairing mechanical force-induced bone formation in vivo. Moreover, knockdown of FOXO3 effectively inhibited the mechanical force-induced osteoblastic differentiation of BMSCs, whereas the overexpression of FOXO3 enhanced this effect. Mechanistically, we revealed a novel regulatory model in which FOXO3 promoted osteocalcin transcription by activating its promoter in cooperation with runt-related transcription factor 2 (RUNX2). We collectively obtained the first evidence that FOXO3 is critical for OTM, where it responds to mechanical force and directly regulates downstream osteoblastic differentiation in an efficient manner.

Evolution of diversity and dominance of companies in online activity

Ever since the web began, the number of websites has been growing exponentially. These websites cover an ever-increasing range of online services that fill a variety of social and economic functions across a growing range of industries. Yet the networked nature of the web, combined with the economics of preferential attachment, increasing returns and global trade, suggest that over the long run a small number of competitive giants are likely to dominate each functional market segment, such as search, retail and social media. Here we perform a large scale longitudinal study to quantify the distribution of attention given in the online environment to competing organisations. In two large online social media datasets, containing more than 10 billion posts and spanning more than a decade, we tally the volume of external links posted towards the organisations' main domain name as a proxy for the online attention they receive. We also use the Common Crawl dataset-which contains the linkage patterns between more than a billion different websites-to study the patterns of link concentration over the past three years across the entire web. Lastly, we showcase the linking between economic, financial and market data by exploring the relationships between online attention on social media and the growth in enterprise value in the electric carmaker Tesla. Our analysis shows that despite the fact that we observe consistent growth in all the macro indicators-the total amount of online attention, in the number of organisations with an online presence, and in the functions they perform-we also observe that a smaller number of organisations account for an ever-increasing proportion of total user attention, usually with one large player dominating each function. These results highlight how evolution of the online economy involves innovation, diversity, and then competitive dominance.

A rare multiple primary sarcomatoid carcinoma (SCA) of small intestine harboring driver gene mutations: a case report and a literature review

Primary sarcomatoid carcinoma (SCA) is a type of rare tumor consisting of both malignant epithelial and mesenchymal components. Only 32 cases of SCA of the small bowel have been reported in the literature to date. Due to its rarity and complexity, this cancer has not been genetically studied and its diagnosis and treatment remain difficult. Here we report a 54-year-old male underwent emergency surgical resection in the small intestine due to severe obstruction and was diagnosed with multiple SCA based on postoperative pathological examination. Over 100 polypoid tumors scattered along his whole jejunum and proximal ileum. Chemotherapy (IFO+Epirubicin) was performed after surgery while the patient died two months after the surgery due to severe malnutrition. Whole-exome sequencing was performed for the tumor tissue with normal tissue as the control. Important cancer-related gene mutations, including KRAS (c.37G>T, p.G13C), TP53 (c.871A>T, p.K291*), EGFR (c.1351C>T, p.R451C), and CDKN2A (c.104_138del, p.G35fs), were found among 286 nonsynonymous somatic mutations (SNV and Indel). Copy-number amplified genes mainly gathered in chromosome 6, 7, 16 and 20. Mutation clustering analysis showed that main genetic abnormalities included DNA methylation, DNA alkylation, cellular homeostasis, and shared similarities with melanoma, glioma, prostate cancer, bladder cancer, non-small cell lung cancer, and pancreatic cancer. In summary, the genomic features of the small intestine SCA were explored at whole-exome level for the first time, and over 200 somatic mutations were identified in the tumor tissue. Key tumor driver gene mutations were revealed, as well as several aberrant functional pathways. These results contribute to further understanding of the pathogenesis and molecular mechanism of this rare tumor.

Oil from transgenic Camelina sativa as a source of EPA and DHA in feed for European sea bass (Dicentrarchus labrax L.)

Aquaculture, the fastest growing food production sector cannot continue to rely on finite stocks of marine fish as the primary source of the omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic acid (EPA; 20:5n3) and docosahexaenoic acid (DHA; 22:6n-3), for feeds. A four-month feeding trial was conducted to investigate the impact of a de novo oil, with high levels of EPA and DHA, obtained from transgenic Camelina sativa on growth performance, tissue fatty acid profiles, and expression of lipid metabolism genes when used as a replacement for fish oil in feed for European seabass (Dicentrachus labrax). Triplicate groups of 50 juvenile fish (initial weight 16.7 ± 0.92 g) per tank were fed for 4 months with one of three isolipidic and isoproteic experimental diets consisting of a standard diet containing a commercial blend of fish oil and rapeseed oil (CFO), a diet containing transgenic Camelina oil (TCO), or a blend of fish oil and rapeseed oil with enhanced levels of EPA and DHA (EFO) formulated to match the n-3 LC-PUFA profile of the TCO feed. Final weight of fish fed the GM-derived oil was not different to fish fed either CFO or EFO. Slight lower growth performance of fish fed TCO at the beginning of the trial was related to transient reduced feed intake, possibly caused by glucosinolates in the raw Camelina sativa oil. The GM-derived oil improved the nutritional quality of the fish fillet by enhancing total n-3 PUFA levels compared to the fish fed the other two feeds, and maintained flesh EPA and DHA at the same levels as in fish fed the diets containing fish oil. The metabolic response in liver and intestine was generally relatively mild although diets TCO and EFO seemed to trigger a metabolic response consisting of an up-regulation of both β-oxidation (cpt1a) and fatty acid transport (fabp1), possibly reflecting higher levels of LC-PUFA. Overall, the present study indicated that an oil of terrestrial origin, Camelina sativa, when engineered to contain high levels of EPA and DHA can replace fish oil in feeds for European seabass with no detrimental impact on growth or feed efficiency, while also maintaining or increasing tissue n-3 LC-PUFA contents.

Development of a new dynamic foveated imager on wide-angle infra-red thermography system to improve local spatial resolution in EAST

A new dynamic foveated imager has been developed and commissioned on the wide-angle infra-red thermography system in the Experimental Advanced Superconducting Tokamak. This technique improves the local spatial resolution by a factor of 2 while maintaining the wide-angle view to ensure safety operation. Taking advantage of the new foveated imager, heat flux splitting under the application of resonant magnetic perturbation (RMP) coils has been clearly observed. The results indicate that the toroidal asymmetric power load pattern is closely related to the perturbation field induced by the RMP coils.

Ambient PM2.5 exposures and systemic biomarkers of lipid peroxidation and total antioxidant capacity in early pregnancy

Evidence for effects of PM_2.5 on systemic oxidative stress in pregnant women is limited, especially in early pregnancy. To estimate the associations between ambient PM_2.5 exposures and biomarkers of lipid peroxidation and total antioxidant capacity (T-AOC) in women with normal early pregnancy (NEP) and women with clinically recognized early pregnancy loss (CREPL), 206 early pregnant women who had measurements of serum malondialdehyde (MDA) and T-AOC were recruited from a larger case-control study in Tianjin, China from December 2017 to July 2018. Ambient PM_2.5 concentrations of eight single-day lags exposure time windows before blood collection at the women's residential addresses were estimated using temporally-adjusted land use regression models. Effects of PM_2.5 exposures on percentage change in the biomarkers were estimated using multivariable linear regression models adjusted for month, temperature, relative humidity, gestational age and other covariates. Unconstrained distributed lag models were used to estimate net cumulative effects. Increased serum MDA and T-AOC were significantly associated with increases in PM_2.5 at several lag exposure time windows in both groups. The net effects of each interquartile range increase in PM_2.5 over the preceding 8 days on MDA were significantly higher (p < 0.001) in CREPL [52% (95% CI: 41%, 62%)] than NEP [22% (95% CI: 9%, 36%)] women. Net effects of each interquartile range increase in PM_2.5 over the preceding 5 days on T-AOC were significantly lower (p = 0.010) in CREPL [14% (95% CI: 9%, 19%)] than NEP [24% (95% CI: 18%, 29%)] women. Exposure to ambient PM_2.5 may induce systemic lipid peroxidation and antioxidant response in early pregnant women. More severe lipid peroxidation and insufficient antioxidant capacity associated with PM_2.5 was found in CREPL women than NEP women. Future studies should focus on mechanisms of individual susceptibility and interventions to reduce PM_2.5-related oxidative stress in the first trimester.

[Changes in serum osteoprotegerin/receptor activator of nuclear factor-κB ligand and related indexes of calcium and phosphorus in the early stage of severe burn patients]

Objective: To investigate the early changes in serum osteoprotegerin/receptor activator of nuclear factor-κB ligand (RANKL) and related indexes of calcium and phosphorus in severe burn patients. Methods: Thirty severe burn patients who met the inclusion criteria and were admitted to Tongren Hospital of Wuhan University & Wuhan Third Hospital within 8 hours post injury from June 2017 to December 2018 were recruited into severe burn group (24 males and 6 females, aged (38±13) years). Ten healthy volunteers with normal physical examination results in the Physical Examination Center of the same hospital in the same period of time were recruited into healthy control group (7 males and 3 females, aged (37±8) years). A prospective controlled study was conducted. The fasting venous blood of 5 mL was taken from each patient in severe burn group on post injury day (PID) 1, 7, 14, 21, and 28, respectively, and the fasting venous blood of 5 mL was taken from each volunteer in healthy control group. The serum osteoprotegerin, RANKL, 25 hydroxyvitamin D, and parathyroid hormone (PTH) levels were determined by enzyme-linked immunosorbent assay, and the RANKL/osteoprotegerin ratio was calculated. Serum albumin, serum calcium, and serum phosphorus levels were determined by bromocresol green method, methylthymol blue method, and phosphomolybdic acid method, respectively. Data were statistically analyzed with Fisher's exact probability test, analysis of variance for repeated measurement, Mann-Whitney U test, independent sample t test, and Bonferroni correction. Results: (1) The serum osteoprotegerin levels of patients in severe burn group on PID 1, 7, 14, 21, and 28 were 155.11 (102.91, 187.02), 170.07 (84.60, 196.86), 174.95 (59.09, 208.35), 190.01 (47.08, 214.52), and 188.85 (58.73, 223.13) pg/mL, respectively, which were significantly higher than 33.34 (28.59, 45.68) pg/mL of volunteers in healthy control group, Z=-3.436, -4.311, -3.248, -2.811, -4.217, P<0.01. The serum levels of RANKL of patients in severe burn group on PID 1, 7, 14, 21, and 28 were (1 869±791), (1 746±857), (1 781±713), (2 015±825), and (2 272±583) pg/mL, respectively, significantly higher than (49±16) pg/mL of volunteers in healthy control group, t=12.600, 10.844, 13.294, 13.041, 20.880, P<0.01. The ratios of RANKL/osteoprotegerin of patients in severe burn group on PID 1, 7, 14, 21, and 28 were 12.23 (8.10, 24.73), 11.40 (8.25, 16.96), 11.15 (6.91, 38.32), 12.98 (9.22, 49.68), and 13.91 (10.29, 40.68), respectively, which were significantly higher than 1.17 (0.91, 1.74) of volunteers in healthy control group, Z=-4.560, -4.529, -4.529, -4.560, -4.623, P<0.01. (2) The serum level of 25 hydroxyvitamin D of patients in severe burn group on PID 1 was significantly lower than that of volunteers in healthy control group (Z=-2.749, P<0.01). Compared with those of volunteers in healthy control group, the serum levels of albumin of patients in severe burn group on PID 1, 7, 14, 21, and 28 were significantly lower (t=-4.374, -7.689, -8.257, -7.651, -6.259, P<0.01), the serum levels of PTH were significantly elevated (Z=-4.685, -4.685, -4.685, -4.654, -4.685, P<0.01), and the serum levels of phosphorus were not changed significantly. The serum levels of calcium of patients in severe burn group on PID 1, 7, 14, and 21 were significantly lower than the level of volunteers in healthy control group (Z=-2.375, -3.455, -2.442, -2.016, P<0.05 or P<0.01). Conclusions: The serum osteoprotegerin, RANKL, RANKL/osteoprotegerin ratio, and PTH are increased, and the serum 25 hydroxyvitamin D, albumin, and calcium are decreased in the early stage of severe burn patients, which may be the mechanism leading to bone loss in patients.