Efficacy and Safety of Ferrous Bisglycinate and Folinic Acid in the Control of Iron Deficiency in Pregnant Women: A Randomized,Controlled Trial

Iron deficiency in pregnancy is a major public health problem that causes maternal complications. The objective of this randomized, controlled trial was to examine the bioavailability, efficacy, and safety of oral ferrous bisglycinate plus folinic acid supplementation in pregnant women with iron deficiency. Subjects (12–16 weeks of gestation, n = 120) were randomly allocated to receive oral iron as ferrous bisglycinate (equiv. iron 24 mg) in supplement form with folinic acid and multivitamins (test group, n = 60) or as ferrous fumarate (equiv. iron 66 mg iron, control group, n = 60) after breakfast daily. Iron absorption was assessed by measuring fasted serum iron levels at 1 and 2 h immediately after supplementation. Hematological biomarkers and iron status were assessed before intervention, and at 3 and 6 months. Side effects were monitored throughout the intervention. A significant increase in serum iron was seen in both groups (p < 0.001) during the bioavailability assessment; however, the test group increases were comparatively higher than the control values at each timepoint (p < 0.001). Similarly, both test and control groups demonstrated a statistically significant increases in hemoglobin (Hb) (p < 0.001), erythrocytes (p < 0.001), reticulocytes (p < 0.001), mean corpuscular volume (MCV) (p < 0.001), mean corpuscular hemoglobin (MCH) (p < 0.001), mean corpuscular hemoglobin concentration (MCHC) (p < 0.001), % transferrin saturation (p < 0.001), and ferritin (p < 0.001) at 3 and 6 months after supplementation. However, in all cases, the test group increases were numerically larger than the control group increases at each timepoint. The test intervention was also associated with significantly fewer reports of nausea, abdominal pain, bloating, constipation, or metallic taste (p < 0.001). In conclusion, ferrous bisglycinate with folinic acid as a multivitamin nutraceutical format is comparable to standard ferrous fumarate for the clinical management of iron deficiency during pregnancy, with comparatively better absorption, tolerability, and efficacy and with a lower elemental iron dosage.     

High-speed atomic force microscopy reveals a three-state elevator mechanism in the citrate transporter CitS

The secondary active transporter CitS shuttles citrate across the cytoplasmic membrane of gram-negative bacteria by coupling substrate translocation to the transport of two Na⁺ ions. Static crystal structures suggest an elevator type of transport mechanism with two states: up and down. However, no dynamic measurements have been performed to substantiate this assumption. Here, we use high-speed atomic force microscopy for real-time visualization of the transport cycle at the level of single transporters. Unexpectedly, instead of a bimodal height distribution for the up and down states, the experiments reveal movements between three distinguishable states, with protrusions of ∼0.5 nm, ∼1.0 nm, and ∼1.6 nm above the membrane, respectively. Furthermore, the real-time measurements show that the individual protomers of the CitS dimer move up and down independently. A three-state elevator model of independently operating protomers resembles the mechanism proposed for the aspartate transporter Glt_Ph. Since CitS and Glt_Ph are structurally unrelated, we conclude that the three-state elevators have evolved independently.

The cytoplasmic membrane forms a semipermeable barrier between the cellular interior and the periplasm of bacteria. The trafficking of molecules across the membrane is necessary for the cell’s metabolism and is mediated by membrane transporters. These proteins are embedded in the lipid bilayer and undergo conformational changes leading to alternating exposure of the substrate-binding site to either side of the membrane. In secondary active transporters, the transitions between these conformational changes are strictly coupled to the binding and unbinding of not only the primary transported substrate but also a secondary substrate, which leads to their combined transport. Secondary substrates are usually protons or sodium ions of which membrane gradients are maintained in cells, which thereby provides the free energy gain necessary for substrate transport (1).The secondary active transporter CitS mediates the accumulation of citrate in gram-negative bacteria by mechanistic coupling of substrate translocation to the transport of two Na⁺ ions across the cytoplasmic membrane. In the pathogen Klebsiella pneumoniae, CitS is responsible for citrate uptake in the anaerobic citrate degradation pathway (2). CitS belongs to the 2-HydrocyCarboxylate Transporter family. Other members of this family are capable of transporting mono-, di-, and tricarboxylates containing a 2-hydroxy group. These proteins are involved in several energy conservation pathways such as citrate fermentation, malolactic fermentation, citrolactic fermentation, and oxidative malate decarboxylation (3–5). Crystal structures have been solved of CitS from K. pneumoniae and Salmonella enterica (6). The quaternary structure revealed that CitS is a homodimer, with each protomer consisting of two domains: a dimerization domain located centrally and a transport domain located peripherally (SI Appendix, Fig. S1). This dimeric structural arrangement of CitS leads to the presence of two identical transport routes per complex.Before the first structure of CitS was revealed, the alternating access was explained as a “rocker switch” mechanism similarly to LacY and GlpT, two transporters for which crystal structures were available at the time (7, 8). The publication of the structure of CitS from S. enterica suggested that the translocation of the substrates occurs by an elevator mechanism, similarly to the aspartate transporters Glt_Ph and Glt_Tk (9, 10). The structure of CitS suggests that the dimerization domains serve as central membrane anchor, and the peripheral transport domains can move up and down through the bilayer during turnover as a rigid body. This movement leads to a displacement of the binding site by 17 Å perpendicular to the membrane plane, as well as a rotation by ∼35°, and shuttles the protein between the outward-facing and inward-facing conformations (11). This elevator-type mechanistic interpretation, however, was inferred solely from the static crystal structures, and dynamic experiments have not been reported to test this assumption. In this respect, high-speed atomic force microscopy (HS-AFM) (12–15) offers the advantage of probing membrane proteins in liquid in their lipidic environment with high spatial and temporal resolution (16, 17). Uptake experiments performed on CitS report an apparent turnover rate of roughly once every second at saturating conditions (SI Appendix, Table S1) (18). This rate is within the scanning capabilities of HS-AFM, and here, we report HS-AFM experiments directly visualizing the dynamics of citrate transport, at the single-molecule level, to unveil the molecular mechanism behind transport.     

Aluminum Melt Degassing Process Evaluation Depending on the Design and the Degree of the FDU Unit Graphite Rotor Wear

One of the most important indicators of casting quality is porosity. The formation of pores is largely conditioned by the presence of hydrogen in the batch and subsequently in the melt. The gasification of the melt is the primary factor increasing the porosity of casts. This paper addresses the issue of reducing the melt gasification by using FDU (Foundry Degassing Unit) unit. The gas content in the melt is evaluated by determining the Dichte Index depending on the geometry and the degree of the FDU unit rotor wear. For experiments performed under the operating conditions, three types of graphite rotors with different geometries are used. The extent of melt gasification and the Dichte Index are monitored during the rotor wear, at a rate of 0%, 25%, 50%, 75% and 100% rotor wear. Secondly, the chemical composition of the melt is monitored depending on the design and wear of the rotor. It is proven that the design and the degree of rotor wear do not have significant effect on the chemical composition of the melt and all evaluated samples fell within the prescribed quality in accordance with EN 1706. With regard to the overall comparison of the geometry and wear of individual rotor types, it has been proven that, in terms of efficiency, the individual rotors are mutually equivalent and meet the requirements for melt degassing throughout the service life.     

Structure of Randomly Distributed Nanochain Aggregates on Silicon Substrates: Modeling and Optical Absorption Characteristics

Nanoparticle aggregate structures allow for efficient photon capture, and thus exhibit excellent optical absorption properties. In this study, a model of randomly distributed nanochain aggregates on silicon substrates is developed and analyzed. The Gaussian, uniform, and Cauchy spatial distribution functions are used to characterize the aggregate forms of the nanochains and their morphologies are realistically reconstructed. The relationships between the structural parameters (thickness and filling factor), equivalent physical parameters (density, heat capacity, and thermal conductivity), and visible absorptivity of the structures are established and analyzed. All the above-mentioned parameters exhibit extreme values, which maximize the visible-range absorption; these values are determined by the material properties and nanochain aggregate structure. Finally, Al nanochain aggregate samples are fabricated on Si substrates by reducing the kinetic energy of the metal vapor during deposition. The spectral reflection characteristics of the samples are studied experimentally. The Spearman correlation coefficients for the calculated spectral absorption curves and those measured experimentally are higher than 0.82, thus confirming that the model is accurate. The relative errors between the calculated visible-range absorptivities and the measured data are less than 0.3%, further confirming the accuracy of the model.     

Dried Wild-Grown Mushrooms Can Be Considered a Source of Selected Minerals

Dried mushrooms might be a source of mineral components, which are indispensable for human health. The aim of this study was to determine the contents of calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), and selenium (Se) in dried wild-grown mushrooms (Boletus edulis and Xerocomus badius) available for sale, and to evaluate these mushrooms’ contribution to the daily reference intake of the studied bioelements. The concentrations of mineral components in the mushroom samples were determined by the flame method (Ca, Mg, Fe, Zn, Cu, Mn) and the electrothermal (Se) atomic absorption spectrometry method. The mean Ca, Mg, Fe, Zn, Cu, Mn (in mg/kg), and Se concentrations (in µg/kg) in B. edulis were 82.1, 964.1, 233.4, 97.9, 25.3, 22.1, and 6501.6, respectively, whereas in X. badius: 67.5, 1060.2, 87.8, 197.2, 33.9, 19.8, and 282.4, respectively. We have shown that dried B. edulis can be considered a source of Se. In the case of the other microelements, the tested mushrooms may serve only as additional supplements. Therefore, the studied species of mushrooms cannot be regarded as potential nutritional sources of the macroelements in question. Consumers should be properly informed about this, which should be guaranteed by appropriate legal regulations.     

电致孔条件下巴布剂中青藤碱透皮吸收的药动学研究

目的:将巴布剂结合电致孔透皮给药,与被动扩散透皮给药进行比较,初步考察在电致孔条件下巴布剂中青藤碱透皮吸收的药动学特点.方法:以青风藤为模型药物,以活体兔分别进行被动扩散给药(PD)和电致孔透皮给药(EP),高效液相色谱仪测定不同时间的血药浓度,采用统计矩分析法处理分析血药浓度数据.结果:电致孔技术透皮给药的AUC0→∞为43.396,是被动扩散的1.32倍,体内平均滞留时间为20.025,是被动扩散的86%,cmax为1.825,是被动扩散的1.31倍, tmax减小,比被动扩散提前4 h;消除速率常数λ二者一致;电致孔技术透皮给药的药-时曲线比被动扩散的药-时曲线平滑且下降较慢.结论: 将电致孔技术与巴布剂结合能够提高药物透皮吸收的速度和程度,从而提高生物利用度.     

Acoustic Metamaterials for Low-Frequency Noise Reduction Based on Parallel Connection of Multiple Spiral Chambers

Acoustic metamaterials based on Helmholtz resonance have perfect sound absorption characteristics with the subwavelength size, but the absorption bandwidth is narrow, which limits the practical applications for noise control with broadband. On the basis of the Fabry–Perot resonance principle, a novel sound absorber of the acoustic metamaterial by parallel connection of the multiple spiral chambers (abbreviated as MSC-AM) is proposed and investigated in this research. Through the theoretical modeling, finite element simulation, sample preparation and experimental validation, the effectiveness and practicability of the MSC-AM are verified. Actual sound absorption coefficients of the MSC-AM in the frequency range of 360–680 Hz (with the bandwidth Δf₁ = 320 Hz) are larger than 0.8, which exhibit the extraordinarily low-frequency sound absorption performance. Moreover, actual sound absorption coefficients are above 0.5 in the 350–1600 Hz range (with a bandwidth Δf₂ = 1250 Hz), which achieve broadband sound absorption in the low–middle frequency range. According to various actual demands, the structural parameters can be adjusted flexibly to realize the customization of sound absorption bandwidth, which provides a novel way to design and improve acoustic metamaterials to reduce the noise with various frequency bands and has promising prospects of application in low-frequency sound absorption.     

Calibration and response of an EMI scanner

Summary Computed tomography provides a measurement of the linear absorption coefficient of material in vivo. The precision and accuracy of the measurements of this parameter made by the EMI scanner have been investigated at all three recommended voltage settings of the machine. The relationship between the EMI number and the linear absorption coefficient was found to be linear despite the polychromatic nature of the X-ray beam. The spatial resolution of the machine and the response to materials at different depths within the section have also been investigated.     

Characterization and Performance Evaluation of Metakaolin-Based Geopolymer Foams Obtained by Adding Palm Olein as the Foam Stabilizer

Geopolymer foams with different pore structures can be used in construction, water treatment, and heavy metal adsorption. The preparation of high porosity geopolymer foams using vegetable oil as a foam stabilizer is a feasible and cost-effective route. In this study, metakaolin-based geopolymer foams with hierarchical pore structures were fabricated by adding H₂O₂ as the foaming agent with palm olein as the foam stabilizer. The effects of H₂O₂ and palm olein content on the chemical features and pore structure of geopolymer foams were evaluated. Water absorption, thermal conductivity, and mechanical behaviors of geopolymer foams were also investigated. The results indicate that fatty acid salt surfactants were generated in situ in the geopolymer matrix due to the addition of palm olein. Geopolymer foams with H₂O₂ and palm olein addition possess a homogeneously concentrated macropore distribution. Palm olein exhibits a refining effect on intrinsic pores formed by geopolymerization. In addition, using appropriate amounts of palm olein and H₂O₂, geopolymer foams can achieve higher open porosity and better pore connectivity, resulting in the improvement of water absorption and thermal insulation capacity.     

The Uncertainty Propagation for Carbon Atomic Interactions in Graphene under Resonant Vibration Based on Stochastic Finite Element Model

Graphene is one of the most promising two-dimensional nanomaterials with broad applications in many fields. However, the variations and fluctuations in the material and geometrical properties are challenging issues that require more concern. In order to quantify uncertainty and analyze the impacts of uncertainty, a stochastic finite element model (SFEM) is proposed to propagate uncertainty for carbon atomic interactions under resonant vibration. Compared with the conventional truss or beam finite element models, both carbon atoms and carbon covalent bonds are considered by introducing plane elements. In addition, the determined values of the material and geometrical parameters are expanded into the related interval ranges with uniform probability density distributions. Based on the SFEM, the uncertainty propagation is performed by the Monte Carlo stochastic sampling process, and the resonant frequencies of graphene are provided by finite element computation. Furthermore, the correlation coefficients of characteristic parameters are computed based on the database of SFEM. The vibration modes of graphene with the extreme geometrical values are also provided and analyzed. According to the computed results, the minimum and maximum values of the first resonant frequency are 0.2131 and 16.894 THz, respectively, and the variance is 2.5899 THz. The proposed SFEM is an effective method to propagate uncertainty and analyze the impacts of uncertainty in the carbon atomic interactions of graphene. The work in this paper provides an important supplement to the atomic interaction modeling in nanomaterials.