Effects of electron acceptors on CH4 emission in alpine wetlands

Alpine wetlands are an important source of methane (CH4) and play a key role in the global carbon cycle. Their CH4 emissions largely depend on microbial CH4 production and oxidation processes that involve external electron acceptors. Seasonal precipitation drives redox cycles of humic acids (HAs), iron oxide and sulfur species, which will in turn affect CH4 production and oxidation. To investigate the effects of electron acceptors on CH4 emissions, soil samples from a typical alpine wetland on the Tibetan Plateau were incubated with the addition of ferrihydrite (HFO), HAs, sodium sulfate (SO42-) or combinations (HAs-HFO, HAs-SO42- and HAs-HFO-SO42-). During long-term anaerobic incubation, CH4 concentrations showed similar trends, increasing rapidly from 0 to 60 days, decreasing from 60 to 240 days, and finally slowly increasing again after 240 days, in all treatments except the sterilised control. Thus, the incubation period was divided into the production, consumption and reproduction phases. The addition of HFO, HAs or HAs-containing electron acceptors promoted the rates of both production and consumption of CH4, increasing the production potential of CH4 by 65–100 % and the oxidation potential of CH4 by 58–115 %. On the other hand, SO42- inhibited the production and consumption of CH4, reducing the production potential by 35 % and the oxidation potential by 50 %. Electron acceptors such as HFO, HAs and SO42- play important roles in CH4 emissions. HAs are the dominant factor affecting CH4 emissions in alpine wetlands. From a broader ecological perspective, organic and inorganic electron acceptors play a key role in CH4 production and oxidation under anaerobic conditions, influencing CH4 emissions from alpine wetlands

Associations between maternal complications during pregnancy and childhood asthma: a retrospective cohort study

© 2023 The Authors. Published by the European Respiratory Society. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://openres.ersjournals.com/content/9/2/00548-2022Background Studies on the associations between maternal complications during pregnancy and childhood asthma are exclusively conducted in Western countries. The findings are mixed and may not be translated to other populations. We aimed to investigate the associations among the Chinese population and to determine whether the associations were mediated through pre-term birth, caesarean delivery, low birthweight and not breastfeeding in the first 6 months. Methods We conducted a retrospective cohort study of 166 772 children in Guangzhou, China. Information on maternal gestational hypertension, gestational diabetes and gestational anaemia during pregnancy was extracted from medical records. Ever-diagnosis of asthma in children aged 6–12 years was obtained by questionnaire. Logistic regression models and mediation analyses were used to estimate the adjusted odds ratios (aORs) and 95% confidence intervals for childhood asthma. Results Gestational hypertension, gestational diabetes and gestational anaemia during pregnancy were associated with an increased risk of ever-diagnosed childhood asthma: aOR 1.48 (95% CI 1.37–1.60), 1.71 (95% CI 1.65–1.78) and 1.34 (95% CI 1.26–1.45), respectively. A stronger association was observed for two or three gestational complications (aOR 2.02 (95% CI 1.93–2.16)) than one gestational complication (aOR 1.64 (95% CI 1.52–1.77)). The aOR for the three gestational complications was 1.35 (95% CI 1.26–1.45), 1.63 (95% CI 1.58–1.70) and 1.32 (95% CI 1.24–1.43), respectively, after controlling for the mediators, including pre-term birth, caesarean delivery, low birthweight and not breastfeeding in the first 6 months. Conclusions Gestational hypertension, gestational diabetes and gestational anaemia were associated with childhood asthma, and the associations were partially explained by the mediation effects.This study was supported by National Natural Science Foundation of China (82073571 and 81773457 to J. Tang).Published versio

Sensorineural Hearing Loss as the Prominent Symptom in Meningeal Carcinomatosis

Sensorineural hearing loss (SNHL) has been reported rarely in patients with meningeal carcinomatosis (MC). We summarized the clinical data of eight MC patients with SNHL and 35 patients reported from publications. In the eight patients with SNHL, the medium onset age was 48 (range from 37 to 66) years and six (75%) were male. Seven (87.5%) suffered from headaches as the initial symptom, and they experienced SNHL during the first two months after the occurrence of headaches (0.5 to 2 months, average 1.5 months). The audiogram configuration was flat in three patients (37.5%) and showed total deafness in five patients (62.5%). The damage of cranial nerves VI (abducens) was observed in six patients (75%), and four patients (50%) had cranial nerves VII (facial) injury during the disease course. The percentage of damage of cranial nerves was higher than the patients without SNHL (VIth, 75.0% vs. 13.3%, p = 0.002 and VIIth 50.0% vs. 6.7%, p = 0.012). Four (50%) patients suffered from lung adenocarcinoma as primary tumor, two (25%) experienced stomach adenocarcinoma, one had colon cancer, and one patient was unknown. The symptom of SNHL improved after individualized therapy in four patients (focal radiotherapy and chemotherapy for three patients and whole brain radiotherapy for one patient), but all passed away from 2 to 11 months after diagnosis. Total deafness and flat hearing loss in audiogram were the common types of SNHL resulting from MC. MC patients with SNHL were more likely to suffer from the damage of other cranial nerves, especially to cranial nerves VI and VII. Treatment might improve SNHL, but not improve the case fatality rate

The Effectiveness Assessment of Agricultural Subsidy Policies on Food Security: Evidence from China’s Poverty-Stricken Villages

This paper builds a theoretical model based on a representative peasant household in the neoclassical model, comprehensively considers three types of farmer households in China, and evaluates the effects of the agricultural subsidy policy under equilibrium conditions. Based on the two bottom lines of guaranteeing China’s grain security and ensuring no large-scale return to poverty, this paper uses 2010, 2012, and 2014 tracking survey data from the Mutual Aid Fund for Poverty-Stricken Villages in China to construct an econometric model to evaluate agricultural subsidy effectiveness from the three aspects of farmers’ total sown area, total grain output, and total income. The research draws the following conclusions: (1) Agricultural subsidies can significantly increase the sown area, grain production, and total income of farmers in poverty-stricken areas, which is conducive to improving the farmers’ comprehensive capacity for grain production as well as income, and this conclusion remains valid after performing a series of robustness tests and solving endogeneity problems. (2) The effects of the agricultural subsidy policy are affected by natural conditions, economic development levels, and functional orientation of grain production in different regions, and they have divergent influences on farmers’ total sown area, total output, and total income. (3) Agricultural subsidies boost farmers’ willingness to cultivate grain, reduce land abandonment, and increase the total sown area, total output, and total grain income. The willingness to cultivate grain is an important mechanism that affects the effectiveness of the agricultural subsidy policy

Hot Oscillatory Pressing of Carbon Nanotube-Reinforced Copper Matrix Nanocomposite

Carbon nanotube reinforced copper matrix nanocomposites have great potential in machinery, microelectronics, and other applications. The materials are usually prepared by powder metallurgy processes, in which consolidation is a key step for high performance. To improve the density and mechanical properties, the authors explored the use of hot oscillatory pressing (HOP) to prepare this material. A carbon nanotube reinforced copper matrix nanocomposite was synthesized by both HOP and hot pressing (HP) at various temperatures, respectively. The samples prepared by HOP exhibited significantly higher density and hardness than those prepared by HP at the same temperature, and this was because the oscillatory pressure of HOP produced remarkable plastic deformation in copper matrix during sintering. With the decrease of sintering temperature in HOP, the amount of deformation defect increased gradually, playing a key role in the increasing hardness. This work proves experimentally for the first time that HOP can produce much more plastic deformation than HP to promote densification, and that HOP could be a very promising technique for preparing high-performance carbon nanotube reinforced copper matrix nanocomposites

Influence of Soft Phase and Carbon Nanotube Content on the Properties of Hierarchical AZ61 Matrix Composite with Isolated Soft Phase

Carbon nanotube-reinforced magnesium matrix (CNTs/Mg) composite has great application potential in the transportation industry, but the trade-off between strength and ductility inhibits its widespread application. In order to balance the strength and plasticity of the composite, in this work, on the basis of the AZ61 matrix composite homogeneously reinforced by Ni-coated CNTs (hard phase), 30 vol.% large-size AZ61 particles are introduced as an isolated soft phase to fabricate hierarchical CNTs/AZ61 composites. The compression tests show the fracture strain and compressive strength of this composite increases by 54% and 8%, respectively, compared with homogeneous CNTs/AZ61 composite. During deformation, the hard phase is mainly responsible for bearing the load and bringing high strength, due to the precipitation of the Mg17Al12 phase, uniformly dispersed CNT and strong interfacial bonding of the CNTs/Mg interface through nickel plating and interfacial chemical reaction. Furthermore, the toughening of the soft phase results in high ductility. With the increase in CNT content, the compressive strength of composites is nearly unchanged but the fracture strain gradually decreases due to the stress concentration of CNT and its agglomeration

pH: A core node of interaction networks among soil organo-mineral fractions

Mineral-associated organic matter (MAOM) is the largest soil organic carbon (OC) pool with the longest turnover. MAOM is expected to have relatively little sensitivity to climate change due to mineral protection, but its persistence involves several organo-mineral fractions. The uncertainty in the response of specific organo-mineral fractions to climate change hampers the reliability of predictions of MAOM preservation in the future. Here, we applied a sequential chemical fractionation method integrated with network analysis to investigate MAOM stabilization mechanisms across five alpine ecosystems: alpine desert, alpine steppe, alpine meadow, alpine wetland, and alpine forest. Hierarchical cluster analysis revealed grouping of seven extractable OM fractions in MAOM into three OM clusters: a cluster with weak bondings consisting of water-soluble OM (WSOM) and weakly adsorbed fractions (2.1–21.3% of total OC); a cluster with metal-bound complexes comprising Ca-OM complexes and Fe/Al-OM complexes (3.8–12.2% of total OC); and a cluster with strong bonding composed of Al oxyhydroxides, carbonates and Fe oxyhydroxides (12.2–33.5% of total OC). The relative percentages of OM from soils of the five ecosystems in the three clusters exhibited distinct pH dependence patterns. With the increase in pH, the cluster with weak bondings decreased, and that with strong bondings increased, while the one with metal-bound complexes showed a maximum at weakly acidic pH. Organo-mineral fractions and metal cations in MAOM constructed a complex network with pH as the central node. Results suggest that precipitation does not only alter vegetation type and microbial biomass but also regulate soil pH, which is balanced by specific metal cations, thus resulting in particular pH preference of specific OM clusters. These findings demonstrate that soil pH plays a central role in unveiling MAOM dynamics and can serve as a good predictor of soil organo-mineral fractions across alpine ecosystems

Stigma predicting fertility quality of life among Chinese infertile women undergoing in vitro fertilization–embryo transfer

Objective To investigate stigma and fertility quality of life (FertiQoL) and identify predictors of FertiQoL in Chinese infertile women undergoing in vitro fertilization–embryo transfer (IVF-ET). Methods A descriptive correlational design was adopted to investigate the association between stigma and FertiQoL in 588 infertile women undergoing IVF-ET. The personal information questionnaire, Infertility Stigma Scale (ISS) and FertiQoL tool were used to measure study variables. Results The mean scores of ISS and FertiQoL were 62.59 (SD = 21.58) and 63.64 (SD = 13.72), respectively. There were significant differences of ISS scores among participants with different educational level, residence, occupation, religious belief, financial condition, age group, duration of infertility and infertility treatment, while significant differences of the FertiQoL scores were found in participants with different insurance status, determinism of etiology, infertile type, duration of infertility treatment and cycles of IVF-ET. Pearson’s correlation analysis showed stigma was negatively correlated with FertiQoL (r = −0.081 to −0.669, p < .05). The self-devaluation (β = −0.290, p < .001), social withdrawal (β = −0.237, p < .001), family stigma (β = −0.217, p < .001) and insurance status (β = 0.066, p=.035) were identified as the significant predictor of FertiQoL accounting for 43.5% of variance. Conclusions The stigma was significantly associated with FertiQoL in infertile women undergoing IVF-ET with higher level of stigma predicting poorer FertiQoL. More psychological support should be provided to infertile women to reduce stigma and improve FertiQoL