Causal relationship between kidney stones and gut microbiota contributes to the gut-kidney axis: a two-sample Mendelian randomization study

BackgroundGut microbiota, particularly Oxalobacter formigenes, has been previously reported to be associated with kidney stones. However, the conflicting results from both observational and intervention studies have created substantial uncertainty regarding the contribution of Oxalobacter formigenes to the formation of kidney stone.MethodsWe employed a two-sample MR analysis to investigate the causal relationship between gut microbiota and kidney stones using GWASs summary statistics obtained from the MiBioGen and FinnGen consortia. Moreover, we conducted a reserve MR analysis to assess the direction of the causal associations between gut microbiota and kidney stones. The inverse variance weighted (IVW) approach represents the primary method of Mendelian Randomization (MR) analysis.ResultsOur analyses do not yield supportive evidence for a causal link between the genus Oxalobacter (OR = 0.99, 95% CI: 0.90–1.09, p = 0.811) and the formation of kidney stones. The order Actinomycetales (OR = 0.79, 95% CI: 0.65–0.96, p = 0.020), family Actinomycetaceae (OR = 0.79, 95% CI: 0.65–0.96, p = 0.019), family Clostridiaceae 1 (OR = 0.80, 95% CI: 0.67–0.96, p = 0.015), genus Clostridiumsensustricto 1 (OR = 0.81, 95% CI: 0.67–0.98, p = 0.030) and genus Hungatella (OR = 0.86, 95% CI: 0.74–0.99, p = 0.040) had protective effects on kidney stones, and the genus Haemophilus (OR = 1.16, 95% CI: 1.01–1.33, p = 0.032), genus Ruminococcaceae (UCG010) (OR = 1.38, 95% CI: 1.04–1.84, p = 0.028), genus Subdoligranulum (OR = 1.27, 95% CI: 1.06–1.52, p = 0.009) were risk factors for kidney stones. Differential abundance analysis provide no evidence of a association between Oxalobacter formigenes and kidney stones, and showed genus Subdoligranulum were risk factors for kidney stones. Reverse MR analysis did not indicate any causal association of kidney stones on gut microbiota. No considerable heterogeneity of instrumental variables or horizontal pleiotropy was observed.ConclusionOur two-sample MR study did not find any causal relationship between genus Oxalobacter and kidney stones. The association between gut microbiota and kidney stones does not solely depend on the presence of genus Oxalobacter/Oxalobacter formigenes. A more integrated approach using multiple omics platforms is needed to better understand the pathogenesis of kidney stones in the context of complex gene–environment interactions over time

Lifestyle factors, serum parameters, metabolic comorbidities, and the risk of kidney stones: a Mendelian randomization study

Background and objectiveThe early identification of modifiable risk factors is important for preventing kidney stones but determining causal associations can be difficult with epidemiological data. We aimed to genetically assess the causality between modifiable factors (lifestyle factors, serum parameters, and metabolic comorbidities) and the risk of kidney stones. Additionally, we aimed to explore the causal impact of education on kidney stones and its potential mediating pathways.MethodsWe conducted a two-sample Mendelian randomization (MR) study to explore the causal association between 44 modifiable risk factors and kidney stones. The FinnGen dataset initially explored the causal relationship of risk factors with kidney stones and the UK Biobank dataset was used as the validation set. Then, a meta-analysis was conducted by combining discovery and validation datasets. We used two-step MR to assess potential mediators and their mediation proportions between education and kidney stones.ResultsThe combined results indicated that previous exposures may increase the risk of kidney stones, including sedentary behavior, urinary sodium, the urinary sodium/potassium ratio, the urinary sodium/creatinine ratio, serum calcium, 25-hydroxyvitamin D (25OHD), the estimated creatinine-based glomerular filtration rate (eGFRcrea), GFR estimated by serum cystatin C (eGFRcys), body mass index (BMI), waist circumference, type 2 diabetes mellitus (T2DM), fasting insulin, glycated hemoglobin, and hypertension. Coffee intake, plasma caffeine levels, educational attainment, and the urinary potassium/creatinine ratio may decrease the risk of kidney stones. Ranked by mediation proportion, the effect of education on the risk of kidney stones was mediated by five modifiable risk factors, including sedentary behavior (mediation proportion, 25.7%), smoking initiation (10.2%), BMI (8.2%), T2DM (5.8%), and waist circumference (3.2%).ConclusionThis study provides MR evidence supporting causal associations of many modifiable risk factors with kidney stones. Sedentary lifestyles, obesity, smoking, and T2DM are mediating factors in the causal relationship between educational attainment and kidney stones. Our results suggest more attention should be paid to these modifiable factors to prevent kidney stones

Unveiling the additive-assisted oriented growth of perovskite crystallite for high performance light-emitting diodes.

Solution-processed metal halide perovskites have been recognized as one of the most promising semiconductors, with applications in light-emitting diodes (LEDs), solar cells and lasers. Various additives have been widely used in perovskite precursor solutions, aiming to improve the formed perovskite film quality through passivating defects and controlling the crystallinity. The additive's role of defect passivation has been intensively investigated, while a deep understanding of how additives influence the crystallization process of perovskites is lacking. Here, we reveal a general additive-assisted crystal formation pathway for FAPbI3 perovskite with vertical orientation, by tracking the chemical interaction in the precursor solution and crystallographic evolution during the film formation process. The resulting understanding motivates us to use a new additive with multi-functional groups, 2-(2-(2-Aminoethoxy)ethoxy)acetic acid, which can facilitate the orientated growth of perovskite and passivate defects, leading to perovskite layer with high crystallinity and low defect density and thereby record-high performance NIR perovskite LEDs (~800 nm emission peak, a peak external quantum efficiency of 22.2% with enhanced stability)

Equivalent energized coil model for magnetic field of permanent-magnet spherical actuators

Magnetic field modeling is extremely important for electromagnetic (EM) driven spherical actuators. This paper proposes a novel mathematic modeling method based on equivalent energized coil and Biot-Savart law to formulate the complex magnetic field distribution in three-dimensional (3D) space. The energized coil model is employed as an equivalent substitution of cylindrical permanent magnet (PM) poles. The magnetic field distribution of single energized coil is then formulated analytically. The complete magnetic field model of the actuator with multiple cylindrical PM poles is thus achieved from linear superpositions. Compared with other conventional approaches, as there are no omission of high order of harmonic terms, shape approximation of magnet poles and assumption of evenly distributed flux field, it helps to improve the modeling accuracy. Furthermore, this method is more generic for other flux field applications. It is available for both PM and EM poles, and theoretically could be implemented for other magnet shapes. The computational time may increase for complex magnet shapes and distribution patterns. The proposed method is applied to the spherical actuator with novel 3D magnetic pole array that helps to improve the actuator torque output. Numerical computation is conducted to validate the derived analytical magnetic field model. It shows that the analytical model fits with the result from finite element method (FEM) closely. A research prototype and an automatic experimental platform have been developed. Experiment is thus conducted to measure the magnetic field distribution of the spherical actuator. The data comparison shows that the analytical model matches the experimental measurement result well. The developed model can be employed for subsequent study of torque formulation and control implementation. (C) 2015 Elsevier B.V. All rights reserved

Additional file 1 of Proton pump inhibitors use is associated with a higher prevalence of kidney stones: NHANES 2007–2018

Supplementary Material

Modeling of Torque Output and Magnetic Force for Novel Spherical Actuator with Three-dimensional Pole Arrays

A novel PM spherical actuator based on three-dimensional pole array is proposed and developed in this paper. Conventionally, 2D pole arrays are widely employed in the design of spherical actuators, which constraints the system torque output greatly. The concept of 3D pole array is aimed at improving the torque performance. The torque has been analyzed and the corresponding analytical model is established based on curve fitting method (CFM) due to the importantance to real-time control. Magnetic force has been studied in a similar way. The results shows that the modeling method has a relatively high precision and can be further used in the real-time control