•The review comprehensively evaluated the effects of prenatal exposure to phthalates on neurodevelopment in children for the first time.•The systematic review assessed the effects by different ...gender.•Effects of multiple types of phthalates during pregnancy were evaluated, including DEHP, BBzP, DBP, DMP, DiNP, DiDP, and DnOP.
Phthalate have been detected widely in the environment; while several studies have indicated that prenatal phthalate exposure has adverse effects on neurodevelopment, the results were inconsistent.
We aimed to determine the current research status of the relationship between prenatal exposure to different types of phthalate and cognition and behavioral development in children. We conducted a systematic review to evaluate the current state of knowledge.
We systematically searched PubMed, Web of Science, and EMBASE electronic databases up to May 2018 with manual searches of the references of retrieved publications and relevant reviews. Only birth cohort studies that reported on the association between phthalate exposure and cognitive or behavioral development were included in this review. We evaluated the risk of bias for each of the included studies using a modified instrument based on the Cochrane Collaboration’s “Risk of Bias” tool.
Twenty-six birth cohort studies met our inclusion criteria, nine of which investigated the impact of phthalate exposure during pregnancy on cognition, 13 on neurobehavior, and 4 on both cognition and neurobehavior. However, ten articles reported that the effect of prenatal exposure to phthalates on cognitive development was statistically significant, 15 articles reported that the effect of prenatal exposure to phthalates on neurobehavior was statistically significant. The effect of prenatal phthalate exposure on neurodevelopment differed according to sex, but the results are inconsistent, for instance, among the five studies investigating the association between mental development index (MDI) and Mono-n-butyl phthalate (MnBP), two of them showed a significantly decreasing MDI scores with increasing concentrations of MnBP among girls, but among boys one study showed the inverse association, another showed the positive association.
Di(2-ethylhexyl) phthalate, dibutyl phthalate, butyl-benzyl phthalate and di-ethyl phthalate exposure during pregnancy was associated with lower cognitive scores and worse behavior in offspring, and sex-specific effects on cognitive, psychomotor, and behavioral development were identified, especially the impact of phthalate exposure on neurobehavior in boys.
This paper proposes a second-order-generalized-integrator (SOGI)-based time-delay compensation method for extending the stable region of a dual-loop grid-current-feedback (GCF) control system. ...According to the analysis, stable region of the dual-loop system should be designed below a certain critical frequency, before time-delay compensation method can be applied. To always meet the requirement, relationship between single-loop converter-current-feedback and dual-loop GCF control is clarified, before a robust inner-loop gain for the dual-loop GCF scheme is determined. Enforcing this gain allows the converter to remain in its stable region, regardless of how its LCL -filter parameters and grid impedance vary. The SOGI-based delay compensation method can then be applied for widening the stable region of the dual-loop GCF scheme, as proven through s-domain Bode diagrams and z -domain root loci. These theoretical proofs are eventually validated by experimental results obtained in the laboratory.
A nonlinear analysis is presented for impact response of carbon nanotube-reinforced composite (CNTRC) structures under thermal conditions. Two plate configurations (i.e., single-layer and sandwich ...plates) are considered, and the nanotube reinforcement is either uniformly-distributed or functionally-graded in the plate thickness direction. The material properties of nanotube reinforced composites are estimated using micromechanical models. The equations of motion are based on a higher-order shear deformation theory with a von Kármán-type of kinematic nonlinearity, and the thermal effects are included by considering the nanotube reinforced composites as temperature-dependent. The equations of motion are solved with a two-step perturbation technique, and the initial stresses caused by either the thermal or in-plane edge loads as in-plane boundary conditions are introduced. The influences of material property gradient, volume fraction distribution, temperature change, initial stress, initial velocity of the impactor, and core-to-face sheet thickness ratio on impact response of plate structures are discussed. The analysis presented can help better understand the nonlinear impact response of functionally-graded materials and facilitate design and optimization of nanocomposite structures against impact and under thermal and other environments.
The second-order generalized integrator based quadrature signal generator (SOGI-QSG) is able to produce in-quadrature signals for many applications, such as frequency estimation, grid ...synchronization, and harmonic extraction. However, the SOGI-QSG is sensitive to input dc and harmonic components with unknown frequencies (e.g., interharmonics). To overcome the drawback, this letter begins by analyzing the dynamic response of SOGI-QSG from the first-order system (FOS) perspective. A second-order SOGI-QSG (SO-SOGI-QSG) with a fourth-order transfer function is then proposed, after referring to the relationship between standard FOS and second-order system. The proposed method is subsequently found to inherit the simplicity of the SOGI-QSG, while demonstrates better disturbance attenuation. Its parameter design procedure is also easy to understand, and can be followed step-by-step without difficulty. Performance of the proposed SO-SOGI-QSG is finally validated by experimental results presented in this letter.
Triggering receptor expressed on myeloid cells 2 (TREM2) is a DAP12-associated receptor expressed in microglia, macrophages, and other myeloid-derived cells. Previous studies have suggested that ...TREM2/DAP12 signaling pathway reduces inflammatory responses and promotes phagocytosis of apoptotic neurons. Recently, TREM2 has been identified as a risk gene for Alzheimer disease (AD). Here, we show that DAP12 stabilizes the C-terminal fragment of TREM2 (TREM2-CTF), a substrate for γ-secretase. Co-expression of DAP12 with TREM2 selectively increased the level of TREM2-CTF with little effects on that of full-length TREM2. The interaction between DAP12 and TREM2 is essential for TREM2-CTF stabilization as a mutant form of DAP12 with disrupted interaction with TREM2 failed to exhibit such an effect. Silencing of either Trem2 or Dap12 gene significantly exacerbated pro-inflammatory responses induced by lipopolysaccharides (LPS). Importantly, overexpression of either full-length TREM2 or TREM2-CTF reduced LPS-induced inflammatory responses. Taken together, our results support a role of DAP12 in stabilizing TREM2-CTF, thereby protecting against excessive pro-inflammatory responses.
TREM2 is a DAP12-coupled receptor associated with neurodegenerative diseases.
Co-expression of DAP12 increased the level of TREM2 C-terminal fragment (TREM2-CTF) which suppressed the release of pro-inflammatory cytokines.
A major function of DAP12 is to stabilize TREM2-CTF, which regulates inflammatory responses in microglia.
Our studies unraveled a novel function of DAP12 and provided new link between TREM2/DAP12 complexes and neuroinflammation.
This paper studied the large amplitude vibration and the nonlinear bending of a sandwich plate with carbon nanotube-reinforced composite (CNTRC) face sheets resting on an elastic foundation in ...thermal environments. The material properties of CNTRC face sheets are assumed to be graded in the thickness direction, and are estimated through a micromechanical model. The governing equation of the plate that includes plate-foundation interaction is solved by a two-step perturbation technique. The thermal effects are also included and the material properties of both CNTRC face sheets and homogeneous core layer are assumed to be temperature-dependent. A detailed parametric study is conducted to study the effects of nanotube volume fraction, core-to-face sheet thickness ratio, temperature change, foundation stiffness and in-plane boundary conditions on the nonlinear vibration characteristics and nonlinear bending behaviors of sandwich plates with functionally graded CNTRC face sheets. The results for the same plate with uniformly distributed CNTRC face sheets are also provided for comparison.
Scope
Gastrointestinal toxicity is one of the major side effects of abdominopelvic tumor radiotherapy. Studies have shown that perillaldehyde (PAH) has antioxidant, antiinflammatory, antimicrobial ...activity, and antitumor effects. This study aims to determine whether PAH has radioprotective effects on radiation‐induced intestinal injury and explore the underlying mechanisms.
Methods and results
C57BL/6J mice are gavaged with PAH for 7 days, then exposed to a single dose of 13 Gy X‐ray total abdominal irradiation (TAI). PAH treatment prolongs the survival time, promotes the survival of crypt cells, attenuates radiation‐induced DNA damage, and mitigates intestinal barrier damage in the irradiated mice. PAH also shows radioprotective effects in intestinal crypt organoids and human intestinal epithelial cells (HIEC‐6). PAH‐mediated radioprotection is associated with the upregulation of nuclear factor erythroid‐2 related factor 2 (Nrf2), activation of the antioxidant pathway, and inhibition of ferroptosis. Notably, treatment with the Nrf2 inhibitor ML385 abolishes the protective effects of PAH, indicating that Nrf2 activation is essential for PAH activity.
Conclusion
PAH inhibits ionizing radiation (IR)‐induced ferroptosis and attenuates intestinal injury after irradiation by activating Nrf2 signaling. Therefore, PAH is a promising therapeutic strategy for IR‐induced intestinal injury.
The middle capacitor voltage of an LCL-filter, if fed back for synchronization, can be used for active damping. An extra sensor for measuring the capacitor current is then avoided. Relating the ...capacitor voltage to existing popular damping techniques designed with capacitor current feedback would however demand a noise-sensitive derivative term. Digital implementation of this derivative term is generally a challenge with many methods presently developed for resolving it. These methods are however still facing drawbacks, which have comprehensively been explained in this paper. Two derivatives are then proposed, based on either second-order or nonideal generalized integrator. Performances of these derivatives have been found to match the ideal "s" function closely. Active damping based on capacitor voltage feedback can therefore be realized accurately. Experimental results presented have verified the effectiveness of the proposed derivative, which can similarly be used with other applications, where differentiation is needed.
Present investigation deals with the nonlinear vibration of a sandwich plate with a homogeneous core and graphene-reinforced composite (GRC) face sheets supported by an elastic foundation under ...thermal environmental conditions. The material properties of GRC face sheets are assumed to be piece-wise functionally graded by changing the volume fraction of graphene in the thickness direction. The material properties of both the homogeneous core and the GRC face sheets are assumed to be temperature-dependent, and are estimated by the extended Halpin-Tsai micromechanical model. Reddy’s higher order shear deformation plate theory and the von Kármán-type kinematic nonlinearity are used to derive the motion equations which account for the plate-foundation interaction and the thermal effects. The nonlinear vibration solutions for the sandwich plate can be obtained by using a two-step perturbation technique. The effects of distribution type of reinforcements, core-to-face sheet thickness ratio, temperature variation, foundation stiffness and in-plane boundary conditions on the nonlinear vibration characteristics of sandwich plates with piece-wise functionally graded GRC face sheets are discussed in detail.
This paper presents an investigation on the nonlinear dynamic response of carbon nanotube-reinforced composite (CNTRC) plates resting on elastic foundations in thermal environments. Two ...configurations, i.e., single-layer CNTRC plate and three-layer plate that is composed of a homogeneous core layer and two CNTRC surface sheets, are considered. The single-walled carbon nanotube (SWCNT) reinforcement is either uniformly distributed (UD) or functionally graded (FG) in the thickness direction. The material properties of FG-CNTRC plates are assumed to be graded in the thickness direction, and are estimated through a micromechanical model. The motion equations are based on a higher-order shear deformation theory with a von Kármán-type of kinematic nonlinearity. The thermal effects are also included and the material properties of CNTRCs are assumed to be temperature-dependent. The equations of motion that includes plate-foundation interaction are solved by a two-step perturbation technique. Two cases of the in-plane boundary conditions are considered. Initial stresses caused by thermal loads or in-plane edge loads are introduced. The effects of material property gradient, the volume fraction distribution, the foundation stiffness, the temperature change, the initial stress, and the core-to-face sheet thickness ratio on the dynamic response of CNTRC plates are discussed in detail through a parametric study.
PDF
