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l-carnitine is essential for mitochondrial β-oxidation and has been used as a lipid-lowering feed additive in humans and farmed animals. d-carnitine is an optical isomer of l-carnitine and dl-carnitine has been widely used in animal feeds. However, the functional differences between l- and d-carnitine are difficult to study because of the endogenous l-carnitine background. In the present study, we developed a low-carnitine Nile tilapia model by treating fish with a carnitine synthesis inhibitor, and used this model to investigate the functional differences between l- and d-carnitine in nutrient metabolism in fish. l- or d-carnitine (0·4 g/kg diet) was fed to the low-carnitine tilapia for 6 weeks. l-carnitine feeding increased the acyl-carnitine concentration from 3522 to 10 822 ng/g and alleviated the lipid deposition from 15·89 to 11·97 % in the liver of low-carnitine tilapia. However, as compared with l-carnitine group, d-carnitine feeding reduced the acyl-carnitine concentration from 10 822 to 5482 ng/g, and increased lipid deposition from 11·97 to 20·21 % and the mRNA expression of the genes involved in β-oxidation and detoxification in the liver. d-carnitine feeding also induced hepatic inflammation, oxidative stress and apoptosis. A metabolomic investigation further showed that d-carnitine feeding increased glycolysis, protein metabolism and activity of the tricarboxylic acid cycle and oxidative phosphorylation. Thus, l-carnitine can be physiologically utilised in fish, whereas d-carnitine is metabolised as a xenobiotic and induces lipotoxicity. d-carnitine-fed fish demonstrates increases in peroxisomal β-oxidation, glycolysis and amino acid degradation to maintain energy homeostasis. Therefore, d-carnitine is not recommended for use in farmed animals.
The effect of maternal folate intake on small-for-gestational-age (SGA) births remains inconclusive. The present study aimed to investigate the associations of maternal folate intake from diet and supplements with the risk of SGA births using data from a cross-sectional study in Shaanxi Province of Northwest China. A total of 7307 women who were within 12 months (median 3; 10th–90th percentile 0–7) after delivery were included. Two-level models were adopted to examine the associations of folate (dietary folate, supplemental folic acid and total folate) intake with the risk of SGA births and birth weight Z score, controlling for a minimum set of confounders that were identified in a directed acyclic graph. Results showed that a higher supplemental folic acid intake during the first trimester was negatively associated with the risk of SGA births (≤60 d v. non-use: OR 0·80; 95 % CI 0·66, 0·96; >60 d v. non-use: OR 0·78; 95 % CI 0·65, 0·94; Ptrend = 0·010; per 10-d increase: OR 0·97; 95 % CI 0·95, 0·99). A higher total folate intake during pregnancy was associated with a reduced risk of SGA births (highest tertile v. lowest tertile: OR 0·77; 95 % CI 0·64, 0·94; Ptrend = 0·010; per one-unit increase in the log-transformed value: OR 0·81; 95 % CI 0·69, 0·95). A similar pattern was observed for the birth weight Z score. Our study suggested that folic acid supplementation during the first trimester and a higher total folate intake during pregnancy were associated with a reduced risk of SGA births.
North-east China occupies an important geographic position for understanding the process of Neolithisation in East Asia. Although archaeologists have long debated the trajectory of change in this region, a lack of intensive survey and excavation has precluded convincing interpretations. This article presents research on the newly excavated sites of Huayang and Taoshan in the southern Lesser Khingan Mountains, with a particular focus on the lithic assemblages. Comparative and environmental analyses demonstrate the largely uniform trajectory of lithic technologies across north-east China and close correspondence with Late Glacial palaeoclimatic and palaeoenvironmental changes.
Under conventional solidification conditions, immiscible alloy melt would undergo large-scale composition segregation after liquid–liquid phase separation, resulting in the loss of properties and application value. In the present study, the ternary immiscible Al70Bi10Sn20 alloy was chosen to study the effect of cooling rate on its resultant microstructure by casting the melt under different cooling conditions. The results indicated that the Al–Bi–Sn alloy with a slow cooling rate exhibits a strong spatial phase separation trend during solidification. However, as the cooling rate increases, the decreasing volume fraction of the segregated Bi–Sn-rich regions indicates the efficient suppression of spatial phase separation. The relatively dispersed distribution of Bi–Sn phase in the Al-rich matrix can be obtained by quenching the melt into water. The influence mechanism of cooling rate on the microstructure of the alloy is also discussed. The present study is beneficial to further tailoring the microstructure of immiscible alloys.
No risk assessment tools for the efficacy of folic acid treatment for hyperhomocysteinaemia (HHcy) have been developed. We aimed to use two common genetic risk score (GRS) methods to construct prediction models for the efficacy of folic acid therapy on HHcy, and the best gene–environment prediction model was screened out. A prospective cohort study enrolling 638 HHcy patients was performed. We used a logistic regression model to estimate the associations of two GRS methods with the efficacy. Performances were compared using area under the receiver operating characteristic curve (AUC). The simple count genetic risk score (SC-GRS) and weighted genetic risk score (wGRS) were found to be independently associated with the efficacy of folic acid treatment for HHcy. Using the SC-GRS, per risk allele increased with a 1·46-fold increased failure risk (P < 0·001) after adjustment for traditional risk factors, including age, sex, BMI, smoking, alcohol consumption, history of diabetes, history of hypertension, history of hyperlipidaemia, history of stroke and history of CHD. When used the wGRS, the association was strengthened (OR = 2·08, P < 0·001). Addition of the SC-GRS and wGRS to the traditional risk model significantly improved the predictive ability by AUC (0·859). A precise gene–environment predictive model with good performance was developed for predicting the treatment failure rate of folic acid therapy for HHcy.
We assessed inheritance of resistance to sugarcane brown rust (Puccinia melanocephala) in selfing F1 populations of wild sugarcane germplasm Erianthus rockii ‘Yundian 95-19’ and E. rockii ‘Yundian 95-20’. We tested parent and selfing F1 individuals for the brown rust resistance gene, Bru1, that has been shown to confer resistance to brown rust in sugarcane. The Bru1 gene was not detected in E. rockii ‘Yundian 95-19’, E. rockii ‘Yundian 95-20’ or their selfing F1 individuals, and we found there was segregation of resistance in the two selfing F1 populations (segregation ratio: 3:1). The results confirmed resistance in E. rockii ‘Yundian 95-19’ and E. rockii ‘Yundian 95-20’ to sugarcane brown rust is controlled by a novel, single dominant gene.
Using polarized light microscopy, the large, triangular or cylindrical second brachial plate of the Petalocrinidae is demonstrated to be a compound brachial formed through fusion of brachial plates along the distal margin of the growing arms. Based on the number of ambulacral bifurcations, brachials from the primibrachitaxis through at least the quintibrachitaxis may have been fused to form this large plate. In Petalocrinus, fused brachials form a second brachial that assumed the same crystallographic orientation, but in Spirocrinus, multidirectional extinctions preserve some of the original multiplate arrangement.
A company’s emphasis on corporate social responsibility (CSR) signals its concern with benefits for society, whereas a company’s emphasis on corporate ability (CA) signals its expertise in delivering good quality products. Product-harm crises often put companies at serious risk. Would a company’s prior emphasis on CSR versus CA mitigate the potential reputation damage of a product-harm crisis? In an experiment, we found that when a product-harm crisis occurred, having a CSR focus softened the public’s negative evaluation of the focal company, but this protective function of CSR was found only among people who had the lay theory that CSR and CA are compatible. The joint effect of CSR focus and the lay theory was mediated by the tendency to exonerate the focal company for the causal responsibility of the crisis.
Conventional underwater navigation and positioning methods for Autonomous Underwater Vehicles (AUVs) either require the installation of acoustic arrays, which make AUVs less independent, or result in cumulative errors. This paper proposes an Underwater Terrain Positioning Method (UTPM) using Maximum a Posteriori (MAP) estimation and a Pulse Coupled Neural Network (PCNN) model for highly accurate navigation by AUVs. The PCNN model is used as a secondary discriminant to effectively identify pseudo-anchor points in flat terrain feature areas and to find the true positioning point, which significantly improves the matching positioning accuracy in these areas. Simulation results show that the proposed method effectively corrects Inertial Navigation System (INS) cumulative errors and has high matching positioning accuracy, which satisfy the requirements of AUV underwater navigation and positioning.
The aim of this study was to investigate the in vivo degradation mechanism and the mechanical properties of poly(lactide-co-glycolide)/beta-tricalcium phosphate (PLGA/β-TCP) composite anchors. Anchors composed of PLGA and β-TCP were implanted in the dorsal subcutaneous tissue of beagle dogs for 6, 12, 16, and 26 weeks. The degradation of the materials was evaluated by measuring the changes in thermal behavior, crystallinity, and mechanical properties. Scanning electron microscope (SEM) was used to observe the surface and longitudinal section of the material. The evaluation of mechanical strength retention and degradation properties suggest that the addition of β-TCP particles efficiently enhances their mechanical properties and thermal characteristics and delays their degradation rate. By analyzing the results of SEM, X-ray diffraction, and differential scanning calorimetry, we can infer that after 12 weeks, the connection between β-TCP and PLGA becomes less compact, which accelerates the decline of mechanical strength.
The acanthocephalans are characterized by a retractible proboscis, armed with rows of recurved hooks, which serves as the primary organ for attachment of the adult worm to the intestinal wall of the vertebrate definitive host. Whilst there is a considerable variation in the size, shape and armature of the proboscis across the phylum, intraspecific variation is generally regarded to be minimal. Consequently, subtle differences in proboscis morphology are often used to delimit congeneric species. In this study, striking variability in proboscis morphology was observed among individuals of Neorhadinorhynchus nudus (Harada, 1938) collected from the frigate tuna Auxis thazard Lacépède (Perciformes: Scombridae) in the South China Sea. Based on the length of the proboscis, and number of hooks per longitudinal row, these specimens of N. nudus were readily grouped into three distinct morphotypes, which might be considered separate taxa under the morphospecies concept. However, analysis of nuclear and mitochondrial DNA sequences revealed a level of nucleotide divergence typical of an intraspecific comparison. Moreover, the three morphotypes do not represent three separate genetic lineages. The surprising, and previously undocumented level of intraspecific variation in proboscis morphology found in the present study, underscores the need to use molecular markers for delimiting acanthocephalan species.
Given the global water challenges, solar-driven steam generation has become a renewed topic recently as an energy-efficient way for clean water production. Here, a hybrid plasmonic structure consisting of a top layer of TiN nanoparticles (NPs) and a bottom layer of mesoporous anodized alumina membrane (AAM) was rationally designed and fabricated. The top TiN NPs with broadband light absorption acted as a plasmonic heating layer, which converted the absorbed light to heat efficiently for interfacial water heating. The AAM acted as the mechanical support layer, guaranteeing the heat isolation and continuous water replenishment. With optimized thickness of the TiN top layer, a solar steam generation efficiency of 87.7% was achieved in this study. This efficiency is comparable or even higher than prior studies. The current work proves the capability of the TiN NPs as an alternative photothermal material.
Previous studies have demonstrated that type 1 diabetes mellitus (T1DM) could be triggered by an early childhood infection. Whether maternal infection during pregnancy is associated with T1DM in offspring is unknown. Therefore, we aimed to study the association using a systematic review and meta-analysis. Eighteen studies including 4304 cases and 25 846 participants were enrolled in this meta-analysis. Odds ratios (ORs) and 95% confidence intervals (CIs) were synthesised using random-effects models. Subgroup analyses and sensitivity analyses were conducted to assess the robustness of associations. Overall, the pooled analysis yielded a statistically significant association between maternal infection during pregnancy and childhood T1DM (OR 1.31, 95% CI 1.07–1.62). Furthermore, six studies that tested maternal enterovirus infection showed a pooled OR of 1.54 (95% CI 1.05–2.27). Heterogeneity from different studies was evident (I2 = 70.1%, P < 0.001) and was mainly attributable to the different study designs, ascertaining methods and sample size among different studies. This study provides evidence for an association between maternal infection during pregnancy and childhood T1DM.
In this work, corrosion-resistant fluoridated Ca–Mg–P composite coatings were prepared on magnesium alloys via a hydrothermal assisted sol–gel process. All these coatings derived from Coating Sols with different F− concentrations are composed of fluoridated hydroxyapatite, magnesium hydroxide, and dittmarite. When F− concentration of Coating Sol is 0.03 M, the coating exhibited uniform and dense surface, and its thickness reached 32 μm, thus possessing a high charge transfer resistance of 312 ± 12.69 kΩ cm2 in simulated body fluid (SBF). Immersion test in SBF showed that this coating could quickly induce the formation of the mineralized layer, implying relatively high bioactivity. After 49 days of immersion, the original composite coating and newly formed mineralized layer reached 60 μm in thickness, providing effective long-term protection for magnesium alloys. These attractive results indicate that this fluoridated Ca–Mg–P composite coating is a promising protective coating on biodegradable magnesium and magnesium alloy implants for orthopaedic applications.
Coherent cuboidal B2 nanoprecipitation in body-centered cubic (BCC)-based high-entropy alloys (HEAs) is important for the improvement of mechanical strength. The present work primarily investigated the effect of Ti substitution for Al on the cuboidal B2 nanoprecipitates in BCC Al0.7NiCoFeCr2 HEAs. A series of (Al,Ti)0.7NiCoFeCr2 HEAs with different Al/Ti ratios were prepared by suction-cast processing, and their microstructures and mechanical properties were then characterized comprehensively. It was found that the substitution of Ti for Al can change the phase structures of ordered precipitation, from the B2-AlNi to a highly ordered L21-Ni2AlTi phase. Especially, a small amount addition of Ti (≤4.2 at.%, Al/Ti ratio ≥2/1) renders the HEAs with cuboidal L21 nanoparticles coherently precipitated into the BCC matrix, which is attributed to the moderate lattice misfit (ε = 0.5–0.6%) between BCC and L21 phases. HEAs with such coherent microstructures exhibit high compressive yield strength of about 1700–1800 MPa. When the Ti content reaches up to 6.25 at.%, the matrix of the alloy will be turned into the σ phase, rather than BCC, leading to a heavy brittleness.