Fetal genetically determined birth weight plays a causal role in earlier puberty timing: evidence from human genetic studies.

STUDY QUESTION: Does fetal genetically determined birth weight associate with the timing of puberty? SUMMARY ANSWER: Lower fetal genetically determined birth weight was causally associated with an earlier onset of puberty, independent of the indirect effects of the maternal intrauterine environment. WHAT IS KNOWN ALREADY: Previous Mendelian randomization (MR) studies have indicated a potential causal link between birth weight, childhood BMI, and the onset of puberty. However, they did not distinguish between genetic variants that have a direct impact on birth weight through the fetal genome (referred to as fetal genetic effects) and those that influence birth weight indirectly by affecting the intrauterine environment (known as maternal genetic effects). It is crucial to emphasize that previous studies were limited because they did not account for the potential bias caused by unaddressed correlations between maternal and fetal genetic effects. Additionally, the proportion of birth weight variation explained by the fetal genome is considerably larger than that of the maternal genome. STUDY DESIGN, SIZE, DURATION: We performed two-sample MR analyses to investigate the causal effect of fetal genetically determined birth weight on puberty timing using summary data from large-scale genome-wide association studies (GWASs) in individuals of European ancestry. PARTICIPANTS/MATERIALS, SETTING, METHODS: From the two most recent GWASs specifically centered on birth weight, which included 406 063 individuals and 423 683 individuals (63 365 trios) respectively, we identified genetic variants associated with fetal genetically determined birth weight, while adjusting for maternal genetic effects. We identified genetic variants associated with childhood BMI from an independent GWAS involving 21 309 European participants. On this basis, we employed two-sample MR techniques to examine the possible causal effects of fetal genetically determined birth weight on puberty timing using a large-scale GWAS of puberty timing (including 179 117 females of European ancestry). Furthermore, we employed advanced analytical methods, specifically MR mediation and MR-Cluster, to enhance our comprehension of the causal relationship between birth weight determined by fetal genetics and the timing of puberty. We also explored the pathways through which childhood BMI might act as a mediator in this relationship. MAIN RESULTS AND THE ROLE OF CHANCE: In the univariable MR analysis, a one SD decrease in fetal genetically determined birth weight (∼ 418 g) was associated with a 0.16 (95% CI [0.07-0.26]) years earlier onset of puberty. The multivariable MR analysis including fetal genetically determined birth weight and childhood BMI in relation to puberty timing provided compelling evidence that birth weight had a direct influence on the timing of puberty. Lower birth weight (one SD) was associated with an earlier onset of puberty, with a difference of 0.23 (95% CI [0.05-0.42]) years. We found little evidence to support a mediating role of childhood BMI between birth weight and puberty timing (-0.07 years, 95% CI [-0.20 to 0.06]). LIMITATIONS, REASONS FOR CAUTION: Our data came from European ancestry populations, which may restrict the generalizability of our results to other populations. Moreover, our analysis could not investigate potential non-linear relationships between birth weight and puberty timing due to limitations in genetic summary data. WIDER IMPLICATIONS OF THE FINDINGS: Findings from this study suggested that low birth weight, determined by the fetal genome, contributes to early puberty, and offered supporting evidence to enhance comprehension of the fetal origins of disease hypothesis. STUDY FUNDING/COMPETING INTEREST(S): C.Z. was funded by the Sichuan Province Science and Technology Program [grant number 2021JDR0189]. J.Z. was supported by grants from the National Natural Science Foundation of China [grant number 82373588]. No other authors declare any sources of funding. The authors have no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Diagnosis of soil contamination using microbiological indices: A review on heavy metal pollution.

Heavy metal contamination of soil has become a serious global issue because of their persistence in the environment and the non-biodegradable nature leading to their accumulation to toxic levels. In order to achieve early warning and prevent soil quality from deteriorating, it is necessary to select suitable indices to diagnose heavy metal pollution. Microbiological indices for monitoring soil pollution by heavy metals are gaining attention. However, the related researches are scattered, and critical review is imperative. This review is mainly to provide readers with an in-depth understanding of the merits and limitations of microbiological indices for heavy metals contaminated and remediated soils. Microbiological indicators include microbial abundance, community diversity and structure, functional activity. The changes of different microbiological indices and the mechanism of microbial response to heavy metal stress in soils are comprehensively summarized. Furthermore, research gaps and future directions of the microbial ecotoxicological diagnosis of soil contamination by heavy metals are also proposed and discussed.

PbO2 electrode modified by graphene oxide to boost electrodegradation of 4-hydroxybenzophenone.

4-Hydroxybenzophenone (4-OH-BP), a highly toxic and widely used pharmaceutical and personal care products (PPCPs), has been obtained growing concern recently. Electrochemical anodic oxidation technology has been confirmed efficient in eliminating organics from aqueous solution. In this work, we constructed two novel PbO2 electrodes by modifying the middle or active layer with graphene oxide (GO) to degrade aquatic 4-OH-BP. Compared with the pristine PbO2 electrode, the modification by GO could enhance the anchor of the active layer (PbO2 particles) onto the middle layer and improve the isolation of the titanium matrix from the active layer and solution. Therefore, we might obtain the better performance of PbO2 electrodes after modification. Under the experimental conditions optimized by the Box-Behnken design model, as we expected, two novel electrodes (with modified middle layer: 99.85%; with modified active layer: 100%) outperformed the pristine electrode (95.46%) for 4-OH-BP degradation. We proposed the catalytic mechanism of GO-modified electrodes for 4-OH-BP and the degradation pathway of 4-OH-BP and evaluated the toxicity of intermediates based on the quantitative structure-activity relationship model. Furthermore, two GO-modified PbO2 electrodes consumed less energy than commercial boron-doped diamond electrode, reflecting the prominent practicability of GO-modified PbO2 electrode.

Effects of red mud based passivator on the transformation of Cd fraction in acidic Cd-polluted paddy soil and Cd absorption in rice.

Highly effective, economical, and replicable ways of Cd-polluted paddy field remediation (in situ) are urgently needed. In this work, a yearlong field experiment (both early and late rice) was conducted to investigate the effects of red mud based passivator [red mud, diatomite, and lime (5:3:2)] on remediation of an acidic Cd-polluted paddy field in Hunan Province. Compared with the control, the addition of red mud based passivator in the early and late rice reduced Cd concentration in each part of the rice plant (with the most significant decrease rate of 59.18% and 72.11% for brown rice in the early rice and late rice seasons respectively). The effect of Cd reduction in the rice plant was persistent in the next growing season. The addition of red mud based passivator also reduced the exchangeable fraction of Cd in the soil and converted the exchangeable fraction into other unavailable fractions. This study demonstrated that the pH in acidic soil increased after the application of red mud based passivator. Furthermore, red mud based passivator had no effect on the concentrations of Olsen-K, Alkaline-N, Olsen-P in the soil, but increased rice grain yield. Overall, the results of this study indicated that the red mud based passivator at 0.6 kg m-2 could be a recommendation for Cd-polluted acidic paddy soil stabilization, and it would be a suitable method for remediation of Cd-polluted acidic paddy soil.