Global issues in obstetric anaesthesia: perspectives from South Africa, Japan, China, Latin America and North America

South Africa is classified as a low- and middle-income country, with a complex mixture of resource-rich and resource-limited settings. In the major referral hospitals, the necessary skill level exists for the management of complex challenges. However, this contrasts with the frequently-inadequate skill levels of anaesthesia practitioners in resource-limited environments. In Japan, obstetricians administer anaesthesia for 40% of caesarean deliveries and 80% of labour analgesia. Centralisation of delivery facilities is now occurring and it is expected that obstetric anaesthesiologists will be available 24 h a day in centralised facilities in the future. In China, improvements in women's reproductive, maternal, neonatal, child, and adolescent health are critical government policies. Obstetric anaesthesia, especially labour analgesia, has received unprecedented attention. Chinese obstetric anaesthesiologists are passionate about clinical research, focusing on efficacy, safety, and topical issues. The Latin-American region has different landscapes, people, languages, and cultures, and is one of the world's regions with the most inequality. There are large gaps in research, knowledge, and health services, and the World Federation of Societies of Anaesthesiologists is committed to working with governmental and non-governmental organisations to improve patient care and access to safe anaesthesia. Anaesthesia workforce challenges, exacerbated by coronavirus disease 2019, beset North American healthcare. Pre-existing struggles by governments and decision-makers to improve health care access remain, partly due to unfamiliarity with the role of the anaesthesiologist. In addition to weaknesses in work environments and dated standards of work culture, the work-life balance demanded by new generations of anaesthesiologists must be acknowledged.

Beam Energy Dependence of Fifth- and Sixth-Order Net-Proton Number Fluctuations in Au+Au Collisions at RHIC

We report the beam energy and collision centrality dependence of fifth and sixth order cumulants (C_{5}, C_{6}) and factorial cumulants (κ_{5}, κ_{6}) of net-proton and proton number distributions, from center-of-mass energy (sqrt[s_{NN}]) 3 GeV to 200 GeV Au+Au collisions at RHIC. Cumulant ratios of net-proton (taken as proxy for net-baryon) distributions generally follow the hierarchy expected from QCD thermodynamics, except for the case of collisions at 3 GeV. The measured values of C_{6}/C_{2} for 0%-40% centrality collisions show progressively negative trend with decreasing energy, while it is positive for the lowest energy studied. These observed negative signs are consistent with QCD calculations (for baryon chemical potential, μ_{B}≤110  MeV) which contains the crossover transition range. In addition, for energies above 7.7 GeV, the measured proton κ_{n}, within uncertainties, does not support the two-component (Poisson+binomial) shape of proton number distributions that would be expected from a first-order phase transition. Taken in combination, the hyperorder proton number fluctuations suggest that the structure of QCD matter at high baryon density, μ_{B}∼750  MeV at sqrt[s_{NN}]=3  GeV is starkly different from those at vanishing μ_{B}∼24  MeV at sqrt[s_{NN}]=200  GeV and higher collision energies.

Semiparametric Efficient G-estimation with Invalid Instrumental Variables

The instrumental variable method is widely used in the health and social sciences for identification and estimation of causal effects in the presence of potential unmeasured confounding. In order to improve efficiency, multiple instruments are routinely used, leading to concerns about bias due to possible violation of the instrumental variable assumptions. To address this concern, we introduce a new class of G-estimators that are guaranteed to remain consistent and asymptotically normal for the causal effect of interest provided that a set of at least γ out of K candidate instruments are valid, for γ≤K set by the analyst ex ante, without necessarily knowing the identity of the valid and invalid instruments. We provide formal semiparametric efficiency theory supporting our results. Both simulation studies and applications to the UK Biobank data demonstrate the superior empirical performance of our estimators compared to competing methods.

Stress analysis of self-tightness metal sealing against ultrahigh pressure medium

Stress is one of the most important factors in metal-to-metal sealing. In this paper, two methods (theoretical and empirical) were adopted to calculate the normal stress of the brass sealing surfaces against different ultrahigh pressure liquid. The theoretical formula was derived in terms of force balance, and the empirical formula was obtained by polynomial curve fitting, which the fitted data were from simulated results; besides, the results calculated using the empirical formula agree well with the results by theoretical formula. Meanwhile, the equivalent stresses of the brass seal, normal stress and contact stress on the brass seal surfaces were simulated by finite element method, and the simulated results indicated these stresses are increased with the increase of liquid pressure, and the maximum stresses always appear on the tip of the brass seal.

Development and multicenter validation of a novel radiomics-based model for identifying eosinophilic chronic rhinosinusitis with nasal polyps

BACKGROUND

Reliable noninvasive methods are needed to identify endotypes of chronic rhinosinusitis with nasal polyps (CRSwNP) to facilitate personalized therapy. Previous computed tomography (CT) scoring system has limited and inconsistent performance in identifying eosinophilic CRSwNP. We aimed to develop and validate a radiomics-based model to identify eosinophilic CRSwNP.

METHODS

Surgical patients with CRSwNP were recruited from Tongji Hospital and randomly divided into training (n = 232) and internal validation cohort (n = 61). Patients from two additional hospitals served as external validation cohort-1 (n = 84) and cohort-2 (n = 54), respectively. Data were collected from October 2013 to May 2021. Eosinophilic CRSwNP was determined by histological criterion. The least absolute shrinkage and selection operator and the logistic regression (LR) algorithm were used to develop a radiomics model. Univariate and multivariate LR were employed to build models based on CT scores, clinical characteristics, and the combination of radiological and clinical characteristics. Model performance was evaluated by assessing discrimination, calibration, and clinical utility.

RESULTS

The radiomics model based on 10 radiomic features achieved an area under the curve (AUC) of 0.815 in the training cohort, significantly better than the CT score model based on ethmoid-to-maxillary sinus score ratio with an AUC of 0.655. The combination of radiomic features and blood eosinophil count had a further improved performance, achieving an AUC of 0.903. The performance of these models was confirmed in all validation cohorts with satisfying predictive calibration and clinical application value.

CONCLUSIONS

A CT radiomics-based model is promising to identify eosinophilic CRSwNP. This radiomics-based method may provide novel insights in solving other clinical concerns, such as guiding personalized treatment and predicting prognosis in patients with CRSwNP.

Identification and expression pattern analysis of PtCarA and PtCarB genes in Populus trichocarpa under different nitrogen treatments

Carbamoyl phosphate synthetase (CPS) catalyses the synthesis of ammonia carbamoyl phosphate (CP), which plays a key role in the biosynthesis of arginine and pyrimidine nucleotides. There are two subunits of the CPS enzyme in Populus trichocarpa, CarA (small subunit) and CarB (large subunit). Only when they coexist can CPS catalyse synthesis of CP. However, it is not clear how CPS responds to nitrogen (N) to affect arginine and pyrimidine nucleotide biosynthesis. In this study, bioinformatics methods were used to analyse the expression patterns of genes encoding CarA and CarB, and qRT-PCR and RNA-seq were used to investigate their molecular responses under different N concentrations. Phylogenetic analysis revealed that the phylogenetic trees of CarA and CarB had similar topologies. qRT-PCR showed that the PtCarA and PtCarB genes were regulated by N, while their N-regulated patterns differed in different tissues. The expression patterns of PtCarA and PtCarB show a significant positive correlation according to qRT-PCR and RNA-seq. The analysis of promoter cis-acting elements showed that the promoter regions of PtCarA1, PtCarA2 and PtCarB contained some identical cis-acting elements. According to analysis of the phylogenetic tree, expression patterns and promoter elements, we speculate that there might be coevolution among PtCarA1, PtCarA2 and PtCarB. This study provides valuable information for further understanding the function of CPS in poplar, especially for N response, and provides new ideas for studying the evolution of gene families related to heteromultimers.

Fluid shear stress-induced down-regulation of miR-146a-5p inhibits osteoblast apoptosis via targeting SMAD4

Fluid shear stress (FSS) plays an important role in osteoblast apoptosis. However, the role of miRNA in osteoblast apoptosis under FSS and possible molecular mechanisms remain unknown. Our aim of the study was to explore whether miR-146a-5p regulates osteoblast apoptosis under FSS and its molecular mechanisms. FSS could down-regulate the expression of miR-146a-5p in MC3T3-E1 cells. We confirm that up-regulation of miR-146a-5p promotes osteoblasts apoptosis and down-regulation of miR-146a-5p inhibits osteoblasts apoptosis. We further demonstrated that FSS inhibits osteoblast apoptosis by down-regulated miR-146a-5p. Dual-luciferase reporter assay validated that SMAD4 is a direct target gene of miR-146a-5p. In addition, mimic-146a-5p suppressed FSS-induced up-regulation of SMAD4 protein levels, which suggests that FSS elevated SMAD4 protein expression levels via regulation miR-146a-5p. Further investigations showed that SMAD4 could inhibit osteoblast apoptosis. We demonstrated that miR-146a-5p regulates osteoblast apoptosis via targeting SMAD4. Taken together, our present study showed that FSS-induced down-regulation miR-146a-5p inhibits osteoblast apoptosis via target SMAD4. These findings may provide novel mechanisms for FSS to inhibit osteoblast apoptosis, and also may provide a potential therapeutic target for osteoporosis.

Collision-System and Beam-Energy Dependence of Anisotropic Flow Fluctuations

Elliptic flow measurements from two-, four-, and six-particle correlations are used to investigate flow fluctuations in collisions of U+U at sqrt[s_{NN}]=193  GeV, Cu+Au at sqrt[s_{NN}]=200  GeV and Au+Au spanning the range sqrt[s_{NN}]=11.5-200  GeV. The measurements show a strong dependence of the flow fluctuations on collision centrality, a modest dependence on system size, and very little if any, dependence on particle species and beam energy. The results, when compared to similar LHC measurements, viscous hydrodynamic calculations, and trento model eccentricities, indicate that initial-state-driven fluctuations predominate the flow fluctuations generated in the collisions studied.

Correlation between primary family caregiver identity and maternal depression risk in poor rural China

INTRODUCTION

Prenatal and postpartum depression are important public health challenges because of their long-term adverse impacts on maternal and neonatal health. This study investigated the risk of maternal depression among pregnant and postpartum women in poor rural China, along with the correlation between primary family caregiver identity and maternal depression risk.

METHODS

Pregnant women and new mothers were randomly selected from poor rural villages in the Qinba Mountains area in Shaanxi. Basic demographic information was collected regarding the women and their primary family caregivers. The Edinburgh Postnatal Depression Scale was used to identify women at risk of depression, and the Perceived Social Support Scale was used to evaluate perceived family support.

RESULTS

This study included 220 pregnant women and 473 new mothers. The mean proportions of women at risk of prenatal and postpartum depression were 19.5% and 18.6%, respectively. Regression analysis showed that identification of the baby's grandmother as the primary family caregiver was negatively correlated with maternal depression risk (β=-0.979, 95% confidence interval [CI]=-1.946 to -0.012, P=0.047). However, the husband's involvement in that role was not significantly correlated with maternal depression risk (β=-0.499, 95% CI=-1.579 to 0.581, P=0.363). Identification of the baby's grandmother as the primary family caregiver was positively correlated with family support score (β=0.967, 95% CI=-0.062 to 1.996, P=0.065).

CONCLUSION

Prenatal and postpartum depression are prevalent in poor rural China. The involvement of the baby's grandmother as the primary family caregiver may reduce maternal depression risk, but the husband's involvement in that role has no effect.

Obstetric and offspring outcomes in isolated maternal hypothyroxinaemia: a systematic review and meta-analysis

OBJECTIVE

To examine the association between isolated maternal hypothyroxinaemia (IMH) and adverse obstetric outcomes and offspring outcomes and also investigate the effects of levothyroxine therapy on IMH for the above outcomes.

METHODS

We systematically searched PubMed, EMBASE, and Cochrane Library, and the reference lists of key reviews were hand searched on June 9, 2021. Two authors independently screened titles/abstracts. Full articles were further assessed if the information suggested that the study met the inclusion/exclusion criteria, and two researchers performed data extraction and risk-of-bias assessment using standardized tables. Summary relative risks or the mean difference between maternal effects and offspring outcomes were calculated by a random-effects model.

RESULTS

We identified 38 eligible articles (35 cohort studies and two randomized controlled trials [RCT]). Meta-analysis showed that maternal IMH was associated with increased gestational diabetes mellitus, preterm premature rupture of membranes, preterm birth, fetal distress, and macrosomia outcomes in IMH compared to euthyroid women, and the relative risks were 1.42 (1.03-1.96), 1.50 (1.05-2.14), 1.33 (1.15-1.55), 1.75 (1.16-2.65) and 1.62 (1.35-1.94), respectively. IMH was not associated with placenta previa, gestational hypertension, pre-eclampsia, intrauterine growth restriction, and offspring outcomes like birth weight, low birth weight infants, fetal macrosomia, neonatal intensive care, neonatal death, or fetal head circumference. In addition, we did not find an association between IMH and adverse offspring cognitive defects. Due to insufficient data for meta-analysis, it failed to pool the evidence of levothyroxine's therapeutic effect on IMH and their offspring.

CONCLUSIONS AND RELEVANCE

IMH in pregnancy may relate to a few maternal and offspring outcomes. Moreover, there is currently no sufficient evidence that levothyroxine treatment during pregnancy reduces adverse maternal outcomes and disability in offspring. Further investigation to explore the beneficial effects of levothyroxine therapy is warranted.

Observation of Rayleigh-Lamb waves generated by the 2022 Hunga-Tonga volcanic eruption with the POLA detectors at Ny-Ålesund

The eruption of the Hunga-Tonga volcano in the South Pacific Ocean on January 15, 2022, at about 4:15 UTC, generated a violent explosion, which created atmospheric pressure disturbances in the form of Rayleigh-Lamb waves detected all over the globe. Here we discuss the observation of the Hunga-Tonga shock-wave performed at the Ny-Ålesund Research Station on the Spitsbergen island, by the detectors of the PolarquEEEst experiment and their ancillary sensors. Online pressure data as well as the results of dedicated offline analysis are presented and discussed in details. Results include wave arrival times, wave amplitude measurements and wave velocity calculation. We observed five passages of the shock wave with a significance larger than 3 [Formula: see text] and an amplitude up to 1 hPa. The average propagation velocity resulted to be (308 ± 0.6) m/s. Possible effects of the atmospheric pressure variation associated with the shock-wave multiple passages on the cosmic-ray rate at ground level are also investigated. We did not find any significant evidence of this effect.

Parameter Study of Interfacial Capacities for FRP-Steel Bonded Joints Based on 3D FE Modeling

This paper investigated the stress distribution of an adhesive layer for GFRP-steel bonded joints under 22.48 kN tensile loading using a three-dimensional numerical simulation. Firstly, a stress analysis of three paths was conducted, and after comparison, path II (through the middle layer of the bonding layer) was adopted as the analyzing path. Furthermore, a systemically parametric study of the effects of the FRP stiffness (i.e., elastic modulus and thickness), bonding length, adhesive thickness, and adhesive modulus was conducted. For the joints with different FRP elastic moduli, the minimum value of normal peeling stress was calculated as -3.80 MPa by the FRP for 10 GPa, showing a significantly severe stress concentration of FRP for 10 GPa. An analysis of the von Mises stresses proved that the increase in FRP stiffness could reduce the stress concentration of the adhesive layer effectively. The study of the effect of bonding lengths indicated that a more uniform peeling stress distribution could result from the longest bonding size; the largest peeling stress of 6.54 MPa was calculated for a bonding length of 30 mm. Further parameter analysis showed that the stress concentration of the adhesive layer could be influenced by the FRP thickness, bonding thickness, and elastic modulus of the adhesive layer.