Could Radiotherapy Effectiveness Be Enhanced by Electromagnetic Field Treatment?

One of the main goals in radiobiology research is to enhance radiotherapy effectiveness without provoking any increase in toxicity. In this context, it has been proposed that electromagnetic fields (EMFs), known to be modulators of proliferation rate, enhancers of apoptosis and inductors of genotoxicity, might control tumor recruitment and, thus, provide therapeutic benefits. Scientific evidence shows that the effects of ionizing radiation on cellular compartments and functions are strengthened by EMF. Although little is known about the potential role of EMFs in radiotherapy (RT), the radiosensitizing effect of EMFs described in the literature could support their use to improve radiation effectiveness. Thus, we hypothesized that EMF exposure might enhance the ionizing radiation effect on tumor cells, improving the effects of RT. The aim of this paper is to review reports of the effects of EMFs in biological systems and their potential therapeutic benefits in radiotherapy.     

Effects of Electromagnetic Waves with LTE and 5G Bandwidth on the Skin Pigmentation In Vitro

With the rapid growth of wireless communication devices, the influences of electromagnetic fields (EMF) on human health are gathering increasing attention. Since the skin is the largest organ of the body and is located at the outermost layer, it is considered a major target for the health effects of EMF. Skin pigmentation represents one of the most frequent symptoms caused by various non-ionizing radiations, including ultraviolet radiation, blue light, infrared, and extremely low frequency (ELF). Here, we investigated the effects of EMFs with long-term evolution (LTE, 1.762 GHz) and 5G (28 GHz) bandwidth on skin pigmentation in vitro. Murine and Human melanoma cells (B16F10 and MNT-1) were exposed to either LTE or 5G for 4 h per day, which is considered the upper bound of average smartphone use time. It was shown that neither LTE nor 5G exposure induced significant effects on cell viability or pigmentation. The dendrites of MNT-1 were neither lengthened nor regressed after EMF exposure. Skin pigmentation effects of EMFs were further examined in the human keratinocyte cell line (MNT-1-HaCaT) co-culture system, which confirmed the absence of significant hyper-pigmentation effects of LTE and 5G EMFs. Lastly, MelanoDerm™, a 3D pigmented human epidermis model, was irradiated with LTE (1.762 GHz) or 5G (28 GHz), and image analysis and special staining were performed. No changes in the brightness of MelanoDerm™ tissues were observed in LTE- or 5G-exposed tissues, except for only minimal changes in the size of melanocytes. Collectively, these results imply that exposure to LTE and 5G EMFs may not affect melanin synthesis or skin pigmentation under normal smartphone use condition.     

Effect of linker sequences between the antibody variable domains on the formation, stability and biological activity of a bispecific tandem diabody

Bispecific single-chain Fv antibodies comprise four covalently linked immunoglobulin variable (V(H) and V(L)) domains of two different specificities connected by three linkers. When assembled in the order V(H)(A)-linker(1)-V(L)(B)-linker(2)-V(H)(B)-linker(3)-V(L)(A), the single-chain molecule either folds head-to-tail with the formation of a diabody-like structure, a so-called bispecific single-chain diabody, or forms a homodimer that is twice as large, a so-called tandem diabody. The formation of the tandem diabody is determined by the association of complementary V(H) and V(L) domains located on different polypeptide chains, and depends on the length and probably the amino acid composition of the three linkers joining the variable domains. We generated a number of single-chain constructs using four V(H) and V(L) domains specific either for human CD3, a component of T-cell receptor (TCR) complex, or for CD19, a human B-cell antigen, separated by different rationally designed peptide linkers of 6-27 amino acid residues. The generated bispecific constructs were expressed in bacterial periplasm and their molecular forms, antigen-binding properties, stability, and T-cell proliferative and anti-tumor activities were compared. Using peripheral blood mononuclear cell cultures from patients suffering from B-cell chronic lymphocytic leukemia, we demonstrated that the tandab-mediated activation of autologous T cells and depletion of malignant cells correlates with the stability of the recombinant molecule and with the distance between the CD19 and CD3 binding sites.     

Effect of the Polysaccharide Extract from the Edible Mushroom Pleurotus ostreatus against Infectious Bursal Disease Virus

The polysaccharide-containing extracellular fractions (EFs) of the edible mushroom Pleurotus ostreatus have immunomodulating effects. Being aware of these therapeutic effects of mushroom extracts, we have investigated the synergistic relations between these extracts and BIAVAC and BIAROMVAC vaccines. These vaccines target the stimulation of the immune system in commercial poultry, which are extremely vulnerable in the first days of their lives. By administrating EF with polysaccharides from P. ostreatus to unvaccinated broilers we have noticed slow stimulation of maternal antibodies against infectious bursal disease (IBD) starting from four weeks post hatching. For the broilers vaccinated with BIAVAC and BIAROMVAC vaccines a low to almost complete lack of IBD maternal antibodies has been recorded. By adding 5% and 15% EF in the water intake, as compared to the reaction of the immune system in the previous experiment, the level of IBD antibodies was increased. This has led us to believe that by using this combination of BIAVAC and BIAROMVAC vaccine and EF from P. ostreatus we can obtain good results in stimulating the production of IBD antibodies in the period of the chicken first days of life, which are critical to broilers’ survival. This can be rationalized by the newly proposed reactivity biological activity (ReBiAc) principles by examining the parabolic relationship between EF administration and recorded biological activity.     

Thermodynamic properties of DyNi intermetallic compounds

Electromotive force (EMF) measurements for various DyNi intermetallic compounds in two-phase coexisting states were carried out in the temperature range of 673-773 K in a molten LiCl-KCl-DyCl₃ (0.5 mol%) system. The activities and relative partial molar Gibbs free energies of Dy were obtained from the measured EMFs for various DyNi intermetallic compounds, DyNi₂, DyNi₃, Dy₂Ni₇, and DyNi₅. The relative partial molar entropies and enthalpies of Dy were also calculated from the temperature dependence of the EMFs. The activities and relative partial molar properties of Ni in the compounds were calculated from the activities of Dy by using Gibbs-Duhem equation. Finally, the standard Gibbs free energies of formation for the DyNi intermetallic compounds were estimated.     

抗转铁蛋白受体鼠源性单链抗体基因的构建、表达及初步鉴定

目的　利用基因工程技术将鼠源性单克隆抗体WuT9改造成单链抗体。方法　从分泌抗CD71单克隆抗体的杂交瘤细胞WuT9中提取总RNA ,采用OligodT为逆转录引物 ,逆转录合成cDNA第一链 ,然后分别采用VL 和VH 框架区的PCR引物 ,扩增VH(重链可变区 )和VL(轻链可变区 )DNA片段 ,利用事先合成的存在于VL 下游引物和VH 上游引物的部分人工连接子重叠互补序列 ,将VL 和VH 的PCR回收产物进行部分重叠PCR(SOE) ,形成单链抗体基因。最后将此基因重组进表达载体pBAD gIII C中 ,经L arabinose(左旋阿拉伯糖 )诱导表达并初步鉴定。结果　构建出 70 0bp左右的单链基因 ,并获得阳性重组表达载体克隆 ,表达产物为相对分子质量 2 70 0 0左右的蛋白分子。结论　经因特网查询表明 ,单链抗体基因重链部分属于小鼠H链可变区ⅠA亚组 ;轻链属于小鼠κ轻链可变区Ⅱ亚组 ,此单链抗体基因的表达产物具有一定的特异结合活性。本研究为抗CD71单链抗体的临床应用打下了基础。     

Physiological Electric Field: A Potential Construction Regulator of Human Brain Organoids

Brain organoids can reproduce the regional three-dimensional (3D) tissue structure of human brains, following the in vivo developmental trajectory at the cellular level; therefore, they are considered to present one of the best brain simulation model systems. By briefly summarizing the latest research concerning brain organoid construction methods, the basic principles, and challenges, this review intends to identify the potential role of the physiological electric field (EF) in the construction of brain organoids because of its important regulatory function in neurogenesis. EFs could initiate neural tissue formation, inducing the neuronal differentiation of NSCs, both of which capabilities make it an important element of the in vitro construction of brain organoids. More importantly, by adjusting the stimulation protocol and special/temporal distributions of EFs, neural organoids might be created following a predesigned 3D framework, particularly a specific neural network, because this promotes the orderly growth of neural processes, coordinate neuronal migration and maturation, and stimulate synapse and myelin sheath formation. Thus, the application of EF for constructing brain organoids in a3D matrix could be a promising future direction in neural tissue engineering.     

Enhanced Piezoelectric Performance of Electrospun PVDF-TrFE by Polydopamine-Assisted Attachment of ZnO Nanowires for Impact Force Sensing

In this work, piezoelectric PVDF-TrFE electrospun fibers (EFs) were fabricated using a high-throughput nozzle-free electrospinning process. Zinc oxide (ZnO) nanoparticles were robustly anchored to the PVDF-TrFE EFs, assisted by a self-polymerized polydopamine (PDA) layer, and subsequently grown into ZnO nanowires (NWs) using a low-temperature hydrothermal growth method. The EF mats were investigated for active impact force transduction and the piezoelectric voltage outputs of different combinations of PVDF-TrFE and ZnO nanomaterials were compared using two different impact force testing setups. The horizontal impact force test saw an increase in force sensitivity by a factor of 2.5 for the nanowires compared to the unmodified PVDF-TrFE EFs. Similarly, vertical drop impact testing demonstrated a 5.8-fold increase in sensitivity with a linear response (R² = 0.986) for a large range of impact forces up to 970 N. The EFs were also tested as a wearable impact force sensor to quantify soccer ball heading force, which was measured as 291.3 ± 51.0 N for a vertical ball speed of 7.8 ± 1.5 ms⁻¹¹ with an 8.2% average error compared to theoretical force values. It is believed the enhanced piezoelectric performance of these materials could provide a useful platform for wearable sensing and energy harvesting.     

Scenario modeling of ammonia emissions from surface applied urea under temperate conditions: application effects and model comparison

The use of emission factors (EF) for ammonia (NH₃) after fertilizer application is a central tool for nitrogen management. Ammonia loss measurements after application of urea fertilizer at three research sites in Germany indicated that emissions deviated from European standard EFs. Scenario modelling of emissions based on long term weather data and variable application dates could provide a robust basis for the derivation of EFs. Two model approaches were used to test this approach for urea applied to winter wheat. The two model approaches comprised the dynamic model Volt’Air’ and a statistical model. Scenario calculations were run for 15 years and 4 application dates in each year for the 3 sites. The empirical model performed better at predicting cumulative losses. Both models simulated more than half of relative NH₃ emissions (% urea N applied) in a range of 0–10%. The average and median EFs by both models over all application dates were 10.2 and 8.1%, respectively, and were substantially lower than the current European EFs for urea (15–16%). The lowest median and mean EFs were observed at beginning of the vegetation period with 4.3/4.8 and 7.2/6.7% applied N for empirical and Volt’Air model, respectively, and highest at wheat anthesis (15/17.4 and 11/10.2%). Scenario modelling can be considered as a tool for the derivation of robust and representative EFs for NH₃ emissions not only for urea but also other emitting fertilizer sources. A much more expanded data set is needed and both model approaches require further development to reach this aim.     

A Germline-Encoded Structural Arginine Trap Underlies the Anti-DNA Reactivity of a Murine V Gene Segment

Autoimmunity may have its origins of early repertoire selection in developmental B cells. Such a primary repertoire is probably shaped by selecting B cells that can efficiently perform productive signaling, stimulated by self-antigens in the bone marrow, such as DNA. In support of that idea, we previously found a V segment from V_H10 family that can form antibodies that bind to DNA independent of CDR3 usage. In this paper we designed four antibody fragments in a novel single-chain pre-BCR (scpre-BCR) format containing germinal V gene segments from families known to bind DNA (V_H10) or not (V_H4) connected to a murine surrogate light chain (SLC), lacking the highly charged unique region (UR), by a hydrophilic peptide linker. We also tested the influence of CDR2 on DNA reactivity by shuffling the CDR2 loop. The scpre-BCRs were expressed in bacteria. V_H10 bearing scpre-BCR could bind DNA, while scpre-BCR carrying the V_H4 segment did not. The CDR2 loop shuffling hampered V_H10 reactivity while displaying a gain-of-function in the nonbinding V_H4 germline. We modeled the binding sites demonstrating the conservation of a positivity charged pocket in the V_H10 CDR2 as the possible cross-reactive structural element. We presented evidence of DNA reactivity hardwired in a V gene, suggesting a structural mechanism for innate autoreactivity. Therefore, while autoreactivity to DNA can lead to autoimmunity, efficiently signaling for B cell development is likely a trade-off mechanism leading to the selection of potentially autoreactive repertoires.     

Conformational Motions and Functionally Key Residues for Vitamin B12 Transporter BtuCD–BtuF Revealed by Elastic Network Model with a Function-Related Internal Coordinate

BtuCD–BtuF from Escherichia coli is a binding protein-dependent adenosine triphosphate (ATP)-binding cassette (ABC) transporter system that uses the energy of ATP hydrolysis to transmit vitamin B12 across cellular membranes. Experimental studies have showed that during the transport cycle, the transporter undergoes conformational transitions between the “inward-facing” and “outward-facing” states, which results in the open–closed motions of the cytoplasmic gate of the transport channel. The opening–closing of the channel gate play critical roles for the function of the transporter, which enables the substrate vitamin B12 to be translocated into the cell. In the present work, the extent of opening of the cytoplasmic gate was chosen as a function-related internal coordinate. Then the mean-square fluctuation of the internal coordinate, as well as the cross-correlation between the displacement of the internal coordinate and the movement of each residue in the protein, were calculated based on the normal mode analysis of the elastic network model to analyze the function-related motions encoded in the structure of the system. In addition, the key residues important for the functional motions of the transporter were predicted by using a perturbation method. In order to facilitate the calculations, the internal coordinate was introduced as one of the axes of the coordinate space and the conventional Cartesian coordinate space was transformed into the internal/Cartesian space with linear approximation. All the calculations were carried out in this internal/Cartesian space. Our method can successfully identify the functional motions and key residues for the transporter BtuCD–BtuF, which are well consistent with the experimental observations.     

Impact of the Versatile Aerosol Concentration Enrichment System (VACES) on Gas Phase Species

The performance of the Versatile Aerosol Concentration Enrichment System (VACES) was assessed in terms of the enrichment factor (EF) for highly soluble vapors. Gases ranged in their behavior from a slight enrichment for ammonia (EF(NH ₃ ) = 1.9 ± 0.8) to strong depletion of nitric acid (EF(HNO₃) = 0.12 ± 0.06). H₂O₂ fell in between, with EF(H₂O₂₎ averaging 0.37 (±0.25) and ranging from 0.07 and 0.91 depending on conditions. Detailed results for H₂O₂ indicate that there are two competing processes at play: soluble gases are lost to condensed water in the VACES, particularly in the saturator water bath but also other locations, depleting outlet gas-phase concentrations and resulting in EFs well below 1. Working in the opposite direction, H₂O₂ (and other soluble gases) can also be concentrated together with particles. Presumably, the gases are absorbed into the particles as they take up water, pass through the concentration step, and are released once particles are re-dried. Depending on conditions and the gas solubility, depletion and concentration play larger or smaller roles. The relative importance of these competing processes appear to follow in order of Henry's law solubilities, with modest particle-mediated concentration (resulting in EFs >1) dominating for ammonia, the least soluble gas, and loss in the water bath and other condensed water in the VACES dominating for H₂O₂ and HNO₃, which are more soluble (i.e., have higher Henry's law coefficients).     

Nanoscale Transport Dynamics inside a Hydrated Nafion Membrane with Electric Field Effects

Atomistic simulations were performed to investigate the effects of electric field on the transport dynamics inside a hydrated Nafion membrane. An electric field, varied from 2.5 × 10³ to 7.5 × 10³ V m^–1 simulating the operating voltage from 0.25 to 0.75 V and the membrane thickness of 100 μm was applied along the proton transport direction in the simulation cell. A significant change in the membrane morphology can be observed when the electric field was considered. With increase in the electric field strength, mobilities of hydronium ions and water molecules are enhanced. The difference in the transport phenomena, with and without the electric field, can be visualised from the molecular trajectory diagrams. The distribution of water clusters and their sizes under the influence of the electric field can also be investigated using this molecular analysis technique.     

Accurate correlations to estimate refinery fuel gas,natural gas,and fuel oil CO2 emission factors and its uncertainty

The quantification of Greenhouse Gas (GHG) inventories and its associated uncertainty is a relevant activity often requested by authorities. Accurate methods to calculate both inventories and the involved uncertainty are convenient for close monitoring purposes. Using Monte Carlo simulations, correlations of high accuracy between emission factors (EFs), lower heating value (LHV), and density were built for refinery fuel gas, natural gas and fuel/residual oil. In all cases, the data generated by the simulations also served the purpose of building correlations for upper and lower bounds of the EF that can be readily used to estimate the EF estimation uncertainty. The correlations were tested against actual refinery data and the results show that more accurate estimations were obtained compared with EF obtained from laboratory composition methods and from methods that estimate EF as proportional to LHV only. In the case of fuel and residual oils, the correlations developed are a function of LHV only but were improved by using a cubic polynomial. The calculation of upper and lower bounds for EF offer a convenient method to estimate EF uncertainties that are required in official GHG emissions inventory calculations. In conclusion, in addition to LHV, the use of one additional readily available fuel property, namely fuel density is sufficient to reduce uncertainty of estimation of GHG (in this case CO₂) from combustion to acceptable levels. © 2010 American Institute of Chemical Engineers AIChE J, 2010     

Going Forward Laterally: Transmembrane Passage of Hydrophobic Molecules through Protein Channel Walls

Regular phospholipid bilayers do not pose efficient barriers for the transport of hydrophobic molecules. The outer membrane (OM) surrounding Gram‐negative bacteria is a nontypical, asymmetric bilayer with an outer layer of lipopolysaccharide (LPS). The sugar molecules of the LPS layer prevent spontaneous diffusion of hydrophobic molecules across the OM. As regular OM channels such as porins do not allow passage of hydrophobic molecules, specialized OM transport proteins are required for their uptake. Such proteins, exemplified by channels of the FadL family, transport their substrates according to a lateral diffusion mechanism. Here, substrates diffuse from the lumen of the β‐barrel laterally into the OM, through a stable opening in the wall of the barrel. In this way, the lipopolysaccharide barrier is bypassed and, by depositing the substrates into the OM, a driving force for uptake is provided. Lateral diffusion through protein channel walls also occurs in α‐helical inner membrane proteins, and could represent a widespread mechanism for proteins that transport and interact with hydrophobic substrates.     

TLR4-Mediated Inflammatory Responses Regulate Exercise-Induced Molecular Adaptations in Mouse Skeletal Muscle

Endurance exercise induces various adaptations that yield health benefits; however, the underlying molecular mechanism has not been fully elucidated. Given that it has recently been accepted that inflammatory responses are required for a specific muscle adaptation after exercise, this study investigated whether toll-like receptor (TLR) 4, a pattern recognition receptor that induces proinflammatory cytokines, is responsible for exercise-induced adaptations in mouse skeletal muscle. The TLR4 mutant (TLR4m) and intact TLR4 control mice were each divided into 2 groups (sedentary and voluntary wheel running) and were housed for six weeks. Next, we removed the plantaris muscle and evaluated the expression of cytokines and muscle regulators. Exercise increased cytokine expression in the controls, whereas a smaller increase was observed in the TLR4m mice. Mitochondrial markers and mitochondrial biogenesis inducers, including peroxisome proliferator-activated receptor beta and heat shock protein 72, were increased in the exercised controls, whereas this upregulation was attenuated in the TLR4m mice. In contrast, exercise increased the expression of molecules such as peroxisome proliferator-activated receptor-gamma coactivator 1-alpha and glucose transporter 4 in both the controls and TLR4m mice. Our findings indicate that exercise adaptations such as mitochondrial biogenesis are mediated via TLR4, and that TLR4-mediated inflammatory responses could be involved in the mechanism of adaptation.     

Disrupting the hydrophobic patches at the antibody variable/constant domain interface: improved in vivo folding and physical characterization of an engineered scFv fragment

By constructing Fv and single-chain Fv (scFv) fragments of antibodies, the variable domains are taken out of their natural context in the Fab fragment, where they are associated with the constant domains of the light (CL) and heavy chain (CH1). As a consequence, all residues of the former variable/constant domain interface become solvent exposed. In an analysis of 30 non-redundant Fab structures it was found that at the former variable/constant domain interface of the Fv fragment the frequency of exposed hydrophobic residues is much higher than in the rest of the Fv fragment surface. We investigated the importance of these residues for different properties such as folding in vivo and in vitro, thermodynamic stability, solubility of the native protein and antigen affinity. The experimental model system was the scFv fragment of the anti-fluorescein antibody 4-4-20, of which only 2% is native when expressed in the periplasm of Escherichia coli. To improve its in vivo folding, a mutagenesis study of three newly exposed interfacial residues in various combinations was carried out. The replacement of one of the residues (V84D in VH) led to a 25-fold increase of the functional periplasmic expression yield of the scFv fragment of the antibody 4-4-20. With the purified scFv fragment it was shown that the thermodynamic stability and the antigen binding constant are not influenced by these mutations, but the rate of the thermally induced aggregation reaction is decreased. Only a minor effect on the solubility of the native protein was observed, demonstrating that the mutations prevent aggregation during folding and not of the native protein. Since the construction of all scFv fragments leads to the exposure of these residues at the former variable/constant domain interface, this strategy should be generally applicable for improving the in vivo folding of scFv fragments and, by analogy, also the in vivo folding of other engineered protein domains.      

Identification of pharmacological chaperones for Gaucher disease and characterization of their effects on beta-glucocerebrosidase by hydrogen/deuterium exchange mass spectrometry

Point mutations in beta-glucocerebrosidase (GCase) can result in a deficiency of both GCase activity and protein in lysosomes thereby causing Gaucher Disease (GD). Enzyme inhibitors such as isofagomine, acting as pharmacological chaperones (PCs), increase these levels by binding and stabilizing the native form of the enzyme in the endoplasmic reticulum (ER), and allow increased lysosomal transport of the enzyme. A high-throughput screen of the 50,000-compound Maybridge library identified two, non-carbohydrate-based inhibitory molecules, a 2,4-diamino-5-substituted quinazoline (IC(50) 5 microM) and a 5-substituted pyridinyl-2-furamide (IC(50) 8 microM). They raised the levels of functional GCase 1.5-2.5-fold in N370S or F213I GD fibroblasts. Immunofluorescence confirmed that treated GD fibroblasts had decreased levels of GCase in their ER and increased levels in lysosomes. Changes in protein dynamics, monitored by hydrogen/deuterium-exchange mass spectrometry, identified a domain III active-site loop (residues 243-249) as being significantly stabilized upon binding of isofagomine or either of these two new compounds; this suggests a common mechanism for PC enhancement of intracellular transport.     

基于分子动力学水分和离子在水化硅酸钙纳米孔道中的传输特性研究

水化硅酸钙凝胶是水泥水化产物中最基本的粘结相,水分子和离子在凝胶孔中的传输从根本上决定着水泥混凝土材料的服役寿命.采用分子动力学方法系统地研究了水分子、氯离子和钠离子在1nm、2nm、3nm和4nm的水化硅酸钙凝胶孔中的传输过程.基于径向分布函数和均方位移的离子轨迹分析发现在纳米孔道中离子和水分子展现出异于毛细水的分子结构和动力学特性:水分子有序性排布、离子大量在界面吸附和扩散速度急剧下降.这种分子结构与动力学的特性是因为水化硅酸钙界面处硅链中的非桥接氧会与水分子形成稳定的氢键连接,而钠离子可以形成Na-O化学键,同时表面的钙离子也可以与氯离子形成CaCl2团簇体.此外,随着孔径的增大,离子和水分子的扩散系数逐渐由0.15×10-9m2/s、0.7×10-9m2/s增大到1.3×10-9m2/s、3×10-9m2/s,这很接近于实验测得的毛细水的扩散系数,说明在纳米尺度上,孔径的约束和界面化学键作用是决定离子和水分子传输的关键因素.