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This review highlights the effectiveness and robust nature of eco-friendly room-temperature polymerization initiated in emulsions, and some of its applications in polymer and materials science. The polymerization in emulsions initiated through a thermal or redox approach can be safely conducted under ambient conditions without using other hazardous chemicals. Thermal initiators decompose efficiently at the surfactant-stabilized oil–water interfaces at room temperature. The interface-induced initiation is found to be somewhat independent of surfactant type, insensitive to oxygen, and works for several thermal initiators. Redox initiators without transition metal compounds also effectively initiate room-temperature polymerization in emulsions. With the assistance of room temperature initiation, the polymers synthesized at room temperature are of high molecular mass. In addition, room-temperature polymerization allows temperature-sensitive molecules, for example, proteins and enzymes, to be incorporated with the polymers in situ. The applications of room-temperature polymerization in high internal phase emulsions and biomedicine are also discussed. The initiation of radicals from oil–water interfaces or transition metal-free redox systems is a promising eco-friendly method to promote radical reactions at room temperature. [ABSTRACT FROM AUTHOR]

Projection imaging has been employed widely in many areas, such as x-ray radiography, due to its penetration power and ballistic geometry of their paths. However, its resolution limit remains a major challenge, caused by the conflict of source intensity and source size associated with image blurriness. A simple yet robust scheme has been proposed here to solve the problem. An unconventional square aperture, rather than the usual circular beam, is constructed, which allows for the straightforward deciphering of a blurred spot, to unravel hundreds originally hidden pixels. With numerical verification and experimental demonstration, our proposal is expected to benefit multiple disciplines, not limited to x-ray imaging. [ABSTRACT FROM AUTHOR]

Biochemical pregnancy is a type of embryo transfer failure, patients with unexplained repeated implantation failure (RIF) also have higher biochemical pregnancy rate. Our study intends to evaluate the effect of granulocyte colony-stimulating factor (G-CSF) in patients with unexplained RIF with low hCG levels in early pregnancy. Unexplained RIF patients with low hCG levels after embryo transfer were allocated. G-CSF were administrated from the ninth days after embryo transfer. Clinical pregnancy, miscarriage and live birth rates were evaluated. The clinical pregnancy and live birth rates were 52.5% and 30%. G-CSF is an effective treatment for potential biochemical pregnancy in unexplained RIF patients. [ABSTRACT FROM AUTHOR]

The stem cell niche (SCN) is critical in maintaining continuous postembryonic growth of the plant root. During their growth in soil, plant roots are often challenged by various biotic or abiotic stresses, resulting in damage to the SCN. This can be repaired by the reconstruction of a functional SCN. Previous studies examining the SCN's reconstruction often introduce physical damage including laser ablation or surgical excision. In this study, we performed a time-course observation of the SCN reconstruction in pWOX5:icals3m roots, an inducible system that causes non-invasive SCN differentiation upon induction of estradiol on Arabidopsis (Arabidopsis thaliana) root. We found a stage-dependent reconstruction of SCN in pWOX5:icals3m roots, with division-driven anatomic reorganization in the early stage of the SCN recovery, and cell fate specification of new SCN in later stages. During the recovery of the SCN, the local accumulation of auxin was coincident with the cell division pattern, exhibiting a spatial shift in the root tip. In the early stage, division mostly occurred in the neighboring stele to the SCN position, while division in endodermal layers seemed to contribute more in the later stages, when the SCN was specified. The precise re-positioning of SCN seemed to be determined by mutual antagonism between auxin and cytokinin, a conserved mechanism that also regulates damage-induced root regeneration. Our results thus provide time-course information about the reconstruction of SCN in intact Arabidopsis roots, which highlights the stage-dependent re-patterning in response to differentiated quiescent center. [ABSTRACT FROM AUTHOR]

Purpose: Higher serum estradiol levels occur in women undergoing assisted reproductive technology (ART) owing to ovarian stimulation. Here, we investigated the association between maternal serum estradiol levels and the intellectual development of offspring conceived with ART. Methods: A total of 204 singletons born after fresh embryo transfer were recruited for this cohort study. Among them, 102 children were born from mothers with high serum estradiol levels (> 12,000 pmol/L) on the day that human chorionic gonadotropin was administered. Another 102 children, matched by gestational age and age of the children, were recruited as controls from mothers with low serum estradiol (≤ 12,000 pmol/L). The Wechsler Preschool and Primary Scale of Intelligence was used to evaluate the intellectual development of the children. Results: Children from mothers with higher serum estradiol levels scored lower in the verbal intelligence quotient (IQ) tests and verbal comprehension than children whose mothers had lower estradiol levels. The main difference between the two groups was in verbal subtests including information, vocabulary, and sorting. Partial correlation analysis revealed that the logarithm of maternal serum estradiol level negatively correlated with verbal IQ, performance IQ, and full scale IQ. Conclusion: Our data demonstrate that a high maternal serum estradiol level may negatively associate the verbal ability of children conceived via ART. [ABSTRACT FROM AUTHOR]

Background: In clinical practice, abnormal biochemical changes often occur in women who eventually develop preeclampsia (PE). The study aims to investigate whether maternal serum biochemical markers in the early third trimester can predict PE and neonatal birth weight. Study Design: A retrospective case–control study was performed on 287 women who subsequently developed PE (mild = 139; severe = 148) and 143 healthy women. Fasting venous blood samples of all gravidas were drawn for routine biochemical markers screening in the early third trimester (28.49 ± 1.63 weeks). Appropriate statistical methods were selected for analysis with SPSS software. Results: (1) The concentrations of plasma triglyceride (TG), low-density lipoprotein cholesterol (LDL), and uric acid (UA) in the severe and mild subgroups of the PE group were significantly higher compared with the respective levels in the normal pregnancy groups (3.90 vs. 4.03 vs. 3.14 mmol/L; 3.41 vs. 3.33 vs. 2.89 mmol/L; 365.42 vs. 318.91 vs. 284.69 μmol/L; p < 0.0001). Serum calcium levels in PE group were significantly lower than those in control group (2.10 vs. 2.18 vs. 2.22 mmol/L; p < 0.0001). (2) By using the receiver operating characteristic curve to estimate the diagnosis rate of screening for PE of each marker, the highest sensitivity appeared by the combination of TG, total cholesterol (TC), LDL, high-density lipoprotein cholesterol (HDL), LDL/HDL, UA, Ca2+, and homocysteine (HCY) (79%). The area under curve (AUC) of UA was 0.70, which was the highest among these eight markers, but the AUC of an eight-marker combination model (0.85) had a better diagnostic indication. (3) In PE, the maximum systolic/diastolic blood pressure was significantly positively correlated with serum UA (r = 0.212/0.205, p < 0.0001); and negatively correlated with serum total calcium (r = −0.193/−0.196, p = 0.001). The neonatal birth weight of PE group had a positive correlation with serum TG levels (r = 0.141, p = 0.017) and serum total calcium levels (r = 0.221, p < 0.0001), and a negative correlation with UA levels (r = −0.265, p < 0.0001). Conclusion: The individual marker really performs terrible in predicting PE. Joint monitoring and evaluation of these parameters may improve the screening efficiency for the prediction of PE and poor fetal growth early. [ABSTRACT FROM AUTHOR]

Presents a study which examined the polyimide films containing water by dielectric relaxation and [sup]hydrogen nuclear magnetic resonance spectroscopies. Materials and methods used; Characteristics of the dielectric loss of the Kapton polyimide; Details on the nuclear magnetic resonance of deuteron.

In order to monitor salbutamol (SAL) use in goats as a repartitioning, we determined SAL residues in various tissues of goats after repeated oral SAL administration at a dose of 0.15mg/kg daily for 21 days. SAL concentrations were measured by ultra performance liquid chromatography tandem mass spectrometry in extracts of tissues from goats sacrificed 0.25, 1, 3, 7, 14, 21 and 28 days after the last dose. Our results showed that on Day 0.25 of the withdrawal period, the residual proportions of SAL (expressed as percentage) in liver, kidney, lung, hair, stomachs and muscle were 19.5%, 15.3%, 3.3%, 9.6%, 28.2% and 0.8%, respectively. As the withdrawal time increased, the SAL concentrations in most tissues (except hair) decreased rapidly over the first 3 days and more slowly in the following 25 days. After a 28-day withdrawal period, hair, lung, muscle, liver, fat, eyes, rumen, kidney and abomasum still contained ~32.3%, 15.3%, 7.1%, 6.5%, 5.6%, 1.5%, 0.8% and 0.5% compared to the initial residual concentrations determined on Day 0.25, respectively. On withdrawal Day 28, the highest concentrations of SAL were found in hair (16.58 ± 9.48 μg/kg), followed by liver (7.01 ± 0.94 μg/kg), lung (2.81 ± 1.23 μg/kg), kidney (0.64 ± 0.56 μg/kg), whereas the concentrations in other tissues were lower than limit of quantification (0.50 μg/kg). SAL residues were not detected in bile, plasma and brain on Days 7, 7 and 3 after discontinuation of dosing. These findings indicated that the distribution and depletion rates of SAL differed between tissues. It should be noted that SAL residues in stomach were higher than those in muscles during the early withdrawal. We conclude that hair is the preferred tissue to monitor the administration of SAL to living goats, whereas liver can be used to monitor SAL in the carcass for determination of compliance with food safety regulation. [ABSTRACT FROM AUTHOR]

We report the effect of finer structures, or more levels, in a particular type of planar metallic fractal pattern on the stop bands or band gaps in the transmission spectrum of electromagnetic wave. It is found that the band gaps shift to low frequencies with the increase of levels, showing tunable band gap properties. In addition, we find from both experiments and theoretical calculations that the bands appearing in long wavelength range are determined by individual patterns which compose a 6×6 fractal array, while those bands located in the range of short wavelength are strongly influenced by their neighboring residents. Our experimental observations are in good agreement with those of finite difference time domain simulations. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Gangliosides are glycolipids in which an oligosaccharide headgroup containing one or more sialic acids is connected to a ceramide. Gangliosides reside in the outer leaflet of the plasma membrane and play a crucial role in various physiological processes such as cell signal transduction and neuronal differentiation by modulating structures and functions of membrane proteins. Because the detailed behavior of gangliosides and protein-ganglioside interactions are poorly known, we investigated the interactions between the gangliosides GM1 and GM3 and the proteins aquaporin (AQP1) and WALP23 using equilibrium molecular dynamics simulations and potential of mean force calculations at both coarse-grained (CG) and atomistic levels. In atomistic simulations, on the basis of the GROMOS force field, ganglioside aggregation appears to be a result of the balance between hydrogen bond interactions and steric hindrance of the headgroups. GM3 clusters are slightly larger and more ordered than GM1 clusters due to the smaller headgroup of GM3. The different structures of GM1 and GM3 clusters from atomistic simulations are not observed at the CG level based on the Martini model, implying a difference in driving forces for ganglioside interactions in atomistic and CG simulations. For protein-ganglioside interactions, in the atomistic simulations, GM1 lipids bind to specific sites on the AQP1 surface, whereas they are depleted from WALP23. In the CG simulations, the ganglioside binding sites on the AQP1 surface are similar, but ganglioside aggregation and protein-ganglioside interactions are more prevalent than in the atomistic simulations. Using the polarizable Martini water model, results were closer to the atomistic simulations. Although experimental data for validation is lacking, we proposed modified Martini parameters for gangliosides to more closely mimic the sizes and structures of ganglioside clusters observed at the atomistic level. [ABSTRACT FROM AUTHOR]

Objective(s): Assisted reproductive technology (ART) is associated with DNA methylation dysfunction of offspring. However, it is unclear whether ovarian stimulation (OS) is responsible for DNA methylation dysfunction of offspring STUDY DESIGN: We built the first-generation (F1) and second-generation (F2) offspring mice model of ovarian stimulation. Bodyweight of F1 and F2 were measured. Expression levels of several imprinted genes (Impact, H19, Igf2, Plagl1, Mest, and Snrpn) in F1 placenta were tested. Methylation status of Plagl1 and H19 promoters was examined with bisulfite sequencing. Glucose tolerance, blood pressure, and heart rate were evaluated in F2 mice.Results: The OS F1 showed elevated bodyweights in the 2nd, 3rd and 4th weeks, but the difference disappeared in the 5th week. Plagl1 was down-regulated in OS F1. Promoters of Plagl1 and H19 were also hypermethylated in OS F1. F2 of OS mice had the similar bodyweight and glucose tolerance compared with the control F2. However, F2 of OS ♂F1+OS♀ F1 showed the decreased systolic pressure, diastolic pressure, and heart rate.Conclusions: Ovarian stimulation perturbs expression levels and methylation status of imprinted genes in offspring. The effect of ovarian stimulation may be passed to F2. [ABSTRACT FROM AUTHOR]

This study investigated the ractopamine (RAC) distribution and depletion process in goat plasma, urine and various muscle tissues which were associated with a potential risk for consumer health. The experiment was carried out in 21 goats (18 treated and 3 controls). Treated animals were administered orally a dose of 1 mg/kg body mass per day for 28 consecutive days and randomly sacrificed on Days 0.25, 1, 3, 7, 14 and 21 of the withdrawal period. RAC in goat samples was analyzed by using ultra-high performance liquid chromatography-quadrupole-orbitrap high-resolution mass spectrometry. RAC was below the limits of detection (LOD = 0.15 ng/mL) in plasma while which was higher than the LOD in urine on withdrawal day 21. The residues in goat longissimus dorsi muscle, biceps femoris muscle and triceps surae muscle were differed significantly. These findings demonstrated that urine can be used as the target matrix for monitoring RAC abuse in goat. [ABSTRACT FROM AUTHOR]

Poly(methyl methacrylate) (PMMA)/silica/cetyltrimethylammonium bromide (CTAB) composites were prepared through surfactant catalyzed free radical polymerizations at 40 °C. Fumed silica particles controlled the morphology of the polymeric composites producing porous structures. The internal structures of the porous composite were determined using temperature-modulated differential scanning calorimetry (TMDSC). The fumed silica particles were encapsulated by an incompletely covered CTAB monolayer, with a crystallization temperature, T C,CTAB = 76 °C, and a mixed PMMA/CTAB shell, with T C,CTAB = 63 °C. The fumed silica surfaces acted as inhibitors for PMMA free radical polymerizations. Much of the PMMA formed in the composites was adsorbed on the silica, as evidenced by its elevated glass transition temperature compared to bulk. The enhanced decomposition of the initiator was catalyzed by CTAB and resulted in free radical polymerization of PMMA at 40 °C, which is considerably lower than the temperatures normally used for PMMA synthesis by free radical means with thermal initiation. These lowered polymerization temperatures allow energy efficient production of composites, which can incorporate temperature sensitive materials. [ABSTRACT FROM AUTHOR]

The ATP binding cassette (ABC) transporters form one of the largest protein superfamilies. They use the energy of ATP hydrolysis to transport chemically diverse ligands across membranes. An alternating access mechanism in which the transporter switches between inward- and outward-facing conformations has been proposed to describe the translocation process. One of the main open questions in this process is the degree of opening of the transporter at different stages of the transport cycle, as crystal structures and biochemical data have suggested a wide range of distances between nucleotide binding domains. Recently, the crystal structure of McjD, an antibacterial peptide ABC transporter from Escherichia coli, revealed a new occluded intermediate state of the transport cycle. The transmembrane domain is closed on both sides of the membrane, forming a cavity that can accommodate its ligand, MccJ25, a lasso peptide of 21 amino acids. In this work, we investigate the degree of opening of the transmembrane cavity required for ligand translocation. By means of steered molecular dynamics simulations, the ligand was pulled from the internal cavity to the extracellular side. This resulted in an outward-facing state. Comparison with existing outward-facing crystal structures shows a smaller degree of opening in the simulations, suggesting that the large conformational changes in some crystal structures may not be necessary even for a large substrate like MccJ25. [ABSTRACT FROM AUTHOR]

Alzheimer’s disease (AD) isone of the most common dementia.The aggregation and deposition of the amyloid-β peptide (Aβ)in neural tissue is its characteristic symptom. To destabilize anddissolve Aβ fibrils, a number of candidate molecules have beenproposed. wgx-50 is a compound extracted from Sichuan pepper (Zanthoxylum bungeanum) and a potential candidate drug fortreating AD. Our early experiments show it is effective in disassemblingAβ42 aggregations. A series of molecular dynamics simulationswere performed in this work to explain the molecular mechanism ofthe destabilization of Aβ42 protofibril by wgx-50. It is foundthat there were three possible stable binding sites including twosites in hydrophobic grooves on surface of Aβ protofibril thatmade no significant changes in Aβ structures and one site inthe interior that caused destabilization of the protofibril. In thissite, wgx-50 was packed against the side chains of I32 and L34, disruptedthe D23–K28 salt bridges, and partially opened the tightlycompacted two β-sheets. The results were confirmed by simulationsat 320 K, where deeper insertion of wgx-50 into the whole protofibrilwas observed. The molecular mechanism of this novel drug candidatewgx-50 to disaggregate Aβ protofibril may provide some insightinto the strategy of structure-based drug design for AD. [ABSTRACT FROM AUTHOR]

Polystyrene (PS)/cetyltrimethylammonium bromide (CTAB)/silica composites were prepared by CTAB-catalyzed in-situ polymerization of high internal phase emulsion gels (HIPE gels) at room temperature. The room temperature approach in HIPE gels yielded mono-dispersed PS/CTAB/silica spherical composite particles with sizes of 121 and 155 nm. The complex microscopic internal structures of these particles were determined with the use of temperature-modulated differential scanning calorimetry (TMDSC). CTAB, in particular, was identified in different environments within the composite particles based on its different crystallization temperatures observed on cooling: a thin layer at the surface of the fumed silica ( T C , CTAB = 74 °C), multilayers ( T C , CTAB = 82 °C), and a mixed PS/CTAB shell ( T C , CTAB = 65 °C). The amounts of each component were estimated from the enthalpies of the crystallization. The PS/CTAB mixed shell contained CTAB on the surface of the particle plus internal CTAB domains. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the quality of five commercial enzyme linked immunosorbent assay (ELISA) kits (A, B, C, D, and E) from different suppliers for detecting aflatoxin B1 (AFB1). AFB1-free corn samples supplemented with different levels of AFB1 (5, 10, and 20 μg/kg) were used as positive controls and 6 replicates of each control sample were tested to evaluate the accuracy and precision of these kits. In addition, we also evaluated the performance of these ELISA kits for AFB1 in 30 feed samples, including corn, distillers dried grains with soluble, wheat samples, soybean meal, and poultry feed, which were verified by high performance liquid chromatography. Results showed that the coefficients of variation ranged from 1.18% to 16.22% in intra-plate and 2.85% to 18.04% in inter-plate for the determination of AFB1. The half maximal inhibitory concentration for five kits ranged from 3.72 to 7.22 μg/kg. The quantitation limits of AFB1 were all under the legal limit in China but somewhat inconsistent with kit instructions. Although the recovery rate of four of the five kits were either less than 90% or more than 110%, all these values were acceptable in practice. Two kits had high false positive rates (C and E). In conclusion, our results revealed that the qualities of five tested ELISA kits were significantly different. [ABSTRACT FROM AUTHOR]

Many problems in natural language processing, data mining, information retrieval, and bioinformatics can be formalized as string transformation, which is a task as follows. Given an input string, the system generates the $k$ most likely output strings corresponding to the input string. This paper proposes a novel and probabilistic approach to string transformation, which is both accurate and efficient. The approach includes the use of a log linear model, a method for training the model, and an algorithm for generating the top $k$ candidates, whether there is or is not a predefined dictionary. The log linear model is defined as a conditional probability distribution of an output string and a rule set for the transformation conditioned on an input string. The learning method employs maximum likelihood estimation for parameter estimation. The string generation algorithm based on pruning is guaranteed to generate the optimal top $k$ candidates. The proposed method is applied to correction of spelling errors in queries as well as reformulation of queries in web search. Experimental results on large scale data show that the proposed approach is very accurate and efficient improving upon existing methods in terms of accuracy and efficiency in different settings. [ABSTRACT FROM AUTHOR]

Objective To introduce our device and procedure of electromagnetic navigation (EMN)-guided radiofrequency thermocoagulation (RFT) in patients with trigeminal neuralgia (TN). Methods The EMN system mainly consists of an electromagnetic localizer, a thermoplastic facial mask with fiducial markers, and navigation software. A new surgical interface in which the foramen ovale (FO) and the trigeminal ganglion (TG) were integrated was used. It was applied in three patients with TN. Results FO was successfully and accurately cannulated on the first attempt by using EMN guidance. During the follow-up period, pain did not reoccur, and appropriate trigeminal sensory paresthesia was elicited. There were no surgery-related complications. Conclusion The EMN system is effective and highly accurate for RFT in patients with primary TN. Our modification of the registration system and surgical interface could make the RFT process more simple and accurate. [ABSTRACT FROM AUTHOR]

We present the first computational kinetic model of polyamine metabolism in bloodstream-form Trypanosoma brucei, the causative agent of human African trypanosomiasis. We systematically extracted the polyamine pathway from the complete metabolic network while still maintaining the predictive capability of the pathway. The kinetic model is constructed on the basis of information gleaned from the experimental biology literature and defined as a set of ordinary differential equations. We applied Michaelis-Menten kinetics featuring regulatory factors to describe enzymatic activities that are well defined. Uncharacterised enzyme kinetics were approximated and justified with available physiological properties of the system. Optimisation-based dynamic simulations were performed to train the model with experimental data and inconsistent predictions prompted an iterative procedure of model refinement. Good agreement between simulation results and measured data reported in various experimental conditions shows that the model has good applicability in spite of there being gaps in the required data. With this kinetic model, the relative importance of the individual pathway enzymes was assessed. We observed that, at low-to-moderate levels of inhibition, enzymes catalysing reactions of de novo AdoMet (MAT) and ornithine production (OrnPt) have more efficient inhibitory effect on total trypanothione content in comparison to other enzymes in the pathway. In our model, prozyme and TSHSyn (the production catalyst of total trypanothione) were also found to exhibit potent control on total trypanothione content but only when they were strongly inhibited. Different chemotherapeutic strategies against T. brucei were investigated using this model and interruption of polyamine synthesis via joint inhibition of MAT or OrnPt together with other polyamine enzymes was identified as an optimal therapeutic strategy. [ABSTRACT FROM AUTHOR]

Abstract: Despite its long history, detailed studies on the dynamics of mechanical watch movement are still lacking. In this paper, extending our previous mechanics model, the dynamical wave motion of the hairspring—balance wheel assembly, the core of the timekeeping mechanism called the escapement, is analyzed by partial differential equations. It is found that the corresponding eigenfunctions may be formulated into a Fourier series, through which the relative amplitudes of high order harmonics can be obtained. The relative error incurred owing to the high order harmonics is estimated to be around 10−3, or 102 s/day, much higher than the needed accuracy. This is why manual adjustment is needed in practice. Moreover, addition of the pricy Tourbillon mechanism, which is designed to counteract the gravity effect, is found to trigger complexity in the motion and hence, may not be worth much. [Copyright &y& Elsevier]

Two alternative binding sites of adamantane-type drugs in the influenza A M2 channel have been suggested, one with the drug binding inside the channel pore and the other with four drug molecule S-binding to the C-terminal surface of the transmembrane domain. Recent computational and experimental studies have suggested that the pore binding site is more energetically favorable but the external surface binding site may also exist. Nonetheless, which drug binding site leads to channel inhibition in vivo and how drug-resistant mutations affect these sites are not completely understood. We applied molecular dynamics simulations and potential of mean force calculations to examine the structures and the free energies associated with these putative drug binding sites in an M2-lipid bilayer system. We found that, at biological pH (∼7.4), the pore binding site is more thermodynamically favorable than the surface binding site by ∼7 kcal/mol and, hence, would lead to more stable drug binding and channel inhibition. This result is in excellent agreement with several recent studies. More importantly, a novel finding of ours is that binding to the channel pore requires overcoming a much higher energy barrier of ∼10 kcal/mol than binding to the C-terminal channel surface, indicating that the latter site is more kinetically favorable. Our study is the first computational work that provides both kinetic and thermodynamic energy information on these drug binding sites. Our results provide a theoretical framework to interpret and reconcile existing and often conflicting results regarding these two binding sites, thus helping to expand our understanding of M2-drug binding, and may help guide the design and screening of novel drugs to combat the virus. [ABSTRACT FROM AUTHOR]

The pharmacological activity of a series of novel amide derivatives was characterized on several nicotinic acetyicholine receptors (AChRs). Ca2+ influx results indicate that these compounds are not agonists of the human (h) α4β2, α3β4, α7, and α1/β1γδ AChRs; compounds 2-4 are specific positive allosteric modulators (PAMs) of hα7 AChRs, whereas compounds 1-4, 7, and 12 are noncompetitive antagonists of the other AChRs. Radioligand binding results indicate that PAMs do not inhibit binding of [³H]methyllycaconitine but enhance binding of [³H]epibatidine to hα7 AChRs, indicating that these compounds do not directly, but allosterically, interact with the hα7 agonist sites. Additional competition binding results indicate that the antagonistic action mediated by these compounds is produced by direct interaction with neither the phencydidine site in the Torpedo AChR ion channel nor the imipramine and the agonist sites in the hα4β2 and hα3β4 AChRS. Molecular dynamics and docking results suggest that the binding site for compounds 2-4 is mainly located in the inner β-sheet of the hα7-α7 interface, ∼12 Å from the agonist locus. Hydrogen bond interactions between the amide group of the PAMs and the hα7 AChR binding Site are found to be critical for their activity. The dual PAM and antagonistic activities elicited by compounds 2-4 might be therapeutically important. [ABSTRACT FROM AUTHOR]

The interaction of the agonist JN403 with the human (h) α7 nicotinic acetylcholine receptor (AChR) was compared to that for the competitive antagonist methyllycaconitine (MLA). The receptor selectivity of JN403 was studied on the hα7, hα3β4, and hα4β2 AChRs. The results established that the cationic center and the hydrophobic group found in JN430 and MLA are important for the interaction with the AChRs. MLA preincubation inhibits JN403-induced Ca2+ influx in GH3-hα7 cells with a potency 160-fold higher than that when MLA is co-injected with JN403. The most probable explanation, based on our dynamics results, is that MLA (more specifically the 3-methyl-2,5-dioxopyrrole ring and the B-D rings) stabilizes the resting conformational state. The order of receptor specificity for JN403 is as follows: hα7 > hα3β4 (∼40-fold) > hα4β2 (∼500-fold). This specificity is based on a larger number of hydrogen bonds between the carbamate group (another pharmacophore) of JN403 and the hα7 sites, the electrostatic repulsion between the positively charged residues around the hα3β4 sites and the cationic center of JN403, fewer hydrogen bonds for the interaction of JN403 with the hα3β4 AChR, and an unfavorable van der Waals interaction between JN403 and the α4-β2 interface. The higher receptor specificity for JN403 could be important for the treatment of α7-related disorders, including dementias, pain-related ailments, depression, anxiety, and wound healing. [ABSTRACT FROM AUTHOR]

An experimental approach is employed by using transparent electrodes to investigate the column size distribution where an external electric field applied to a colloidal suspension is increased. The coarsening profile of ER suspension is strongly related to field strength, but is insensitive to particle size. In addition, the interaction among the suspended particles, i.e. the shear stress, corresponding to the mean column diameter is studied and the power-law dependence is found at low field range. However, this dependence is not valid when the field strength surpasses a threshold value. [ABSTRACT FROM AUTHOR]

Abstract: The presence of a surfactant (such as hexadecyltrimethylammonium bromide, CTAB) enhanced the rate of polymerization of styrene in emulsion gels with and without silica. The emulsion gels consisted of styrene, azobisisobutyronitrile (AIBN), surfactant, water, and, in some cases, fumed silica. Polymerization of the emulsions was carried out at room temperature in one or several days depending on the composition of the emulsion. The conversion of monomer to polymer could exceed 90% in a couple of days. In contrast, very little polymerization occurred in the absence of surfactant. A simple model, incorporating a surfactant–initiator complex and standard free radical polymerization, successfully fits the experimental kinetics data. This analysis suggests that the initiator is complexed with approximately three surfactant molecules. [Copyright &y& Elsevier]

Abstract: The decomposition of 2,2′-azobis(isobutyronitrile) (AIBN) at room temperature was studied in emulsion gels, with and without silica, using UV/visible spectroscopy. The emulsion gels consisted of toluene, AIBN, an aqueous solution of a surfactant (either hexadecyltrimethylammonium bromide, CTAB, or sodium dodecyl sulfate, SDS), and, in some cases, fumed silica. The AIBN compositions were determined in the opaque emulsion gels by converting them to transparent microemulsions. The decomposition rate constants for AIBN were determined to be () for the emulsion gels and () for the silica-containing emulsion gels. These rate constants were significantly greater than that in toluene solution, which, by our technique, is below our measurement threshold (effectively 0). [Copyright &y& Elsevier]

Etched V-grooves along the [1 1 0] direction on (0 0 1) surface of Si wafers have been used to achieve high precision alignment between fibers in opto-electronic devices by epoxy-bonding. Nevertheless, the positioning of fibers using epoxy-bonding lacks long-term stability. We developed a novel technology of using metallic solder bonding instead of the organic epoxy-bonding.The challenge is because of the fact that solder does not wet SiO2 surface. To circumvent this problem, electron-beam evaporation was used to deposit a multi-layered metallic coating on the surfaces of fibers and V-grooved chips. Three types of coatings were investigated, and they are Ti/Au, Ti/Cu/Au, and Ti/Ni/Au. These metallic film coatings have good adhesion on the fiber and the V-groove. We utilized a low melting point Pb-free solder, eutectic 43Sn57Bi (in wt.%), with a melting point of 139 °C to bond an array of fibers to V-grooved chips. The mechanical and optical tests illustrated that we can achieve precision alignment of fibers by the soldering method and the bonded structure is stable at room temperature. The metallic solder bonding can be hermetic and it can isolate the optical device from ambient environment. [Copyright &y& Elsevier]

We present a comprehensive theoretical description of quantum well exciton-polaritons imbedded in a planar semiconductor microcavity. The exact nonlacal dielectric response of the quantum well exciton is treated in detail. The 4-spinor structure of the hole subband in the quantum well is considered, including the pronounced band mixing effect. The scheme is self-contained and can be used to treat different semiclassical aspects of the microcavity properties. As an example, we analyze the "selection" rules for the exciton-cavity mode coupling for different excitons. [ABSTRACT FROM AUTHOR]

Charge injection between the active layers in organic semiconducting devices is a key determinant of device function. Accordingly, understanding the effect of intermixing between the layers at these interfaces is of fundamental importance. In this letter, via the use of the time-of-flight method, a comparison is made between the charge injection across discrete versus intermixed interfaces of N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine and 1,1-bis((di-4-tolylamino)phenyl)-cyclohexane doped polycarbonate, semiconducting thin-film layers. No perturbation to the overall charge transport was observed with the discrete interface; however, in contrast the rate of charge transport was clearly reduced through the intermixed interface. [ABSTRACT FROM AUTHOR]

With existing methods it is difficult to measure the mobility of semiconducting thin films that have submicron thickness and submicrosecond charge-carrier transit time. To simplify these measurements we demonstrate a technique that is a combination of the time-of-flight and transient electroluminescence methods. The technique is fundamentally optical in that it decouples the carrier transient signal from the device charging circuit and hence removes the RC time constant constraint that limits existing methods. The technique was applied to measure electron mobility in a tris(8-hydroxyquinoline) aluminum (AlQ3) thin film. Results agree well with mobility values obtained using other methods. [ABSTRACT FROM AUTHOR]

Discrete interfaces between successive layers in an organic semiconducting device simplify any examination of interface barriers for charge transport. To form discrete interfaces between organic layers we propose lamination as an alternate approach to physical vapor deposition. Transient photocurrent measurements as a function of pressure, thickness, and electric field were performed on cells of 1,1-bis[(di-4-tolylamino)phenyl]-cyclohexane (TAPC), N,N-bis(3,4-dimethylphenyl)-4-aminobiphenyl (DMPAB), and N,N’-diphenyl-N,N’-bis(3-methylphenyl)-[1,1’-biphenyl]-4,4’-diamine (TPD). It was found that, in the range 0.8–3.0 MPa, a pressure-laminated interface between two identical materials causes no measurable perturbation to charge transport. This justifies the use of pressure lamination to study interfaces between nonidentical layers. [ABSTRACT FROM AUTHOR]

Introducing a hole-injection-tunable-anode-buffer-layer (HITABL) at the indium tin oxide anode contact of an organic light-emitting device can finely tune hole injection to establish proper charge balance, thus remarkably improves its operational stability. The HITABL consists of two sublayers: (i) an ∼2.5 nm thick metal (e.g., Ca, Mg, or Ag) sublayer and (ii) an ∼10 nm thick tetrafluorotetracyanoquinodimethane (F4TCNQ) doped N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine sublayer. Hole injection can be tuned by changing (i) the metal in the first sublayer and/or (ii) the concentration of the F4TCNQ dopant in the second sublayer. The choice of the metal used in the first sublayer and/or the concentration of F4TCNQ in the second sublayer affect the hole-injection efficiency. Therefore, by using the HITABL, one can make the necessary diminutive adjustments to the hole injection of a device and achieve proper charge balance, resulting in a significant improvement in operational stability. [ABSTRACT FROM AUTHOR]

Extended X-ray Absorption Fine Structure (EXAFS) has been one of the few structural probes available for crystalline, non-crystalline and even highly disordered specimens. However, the data analysis involves a patchy and tinkering process, including back-and-forth fitting and filtering, leading to ambiguous answers sometimes. Here we try to resolve this long standing problem, to extract the inter-atomic distances from the experimental data by a single step minimization, in order to replace the tedious and tinkering process. The new strategy is built firmly by the mathematical logic, and made straightforward and undeniable. The finding demonstrates that it is possible to break off from the traditional patchy model fitting, and to remove the logical confusion of a priori prediction of the structure to be matched with experimental data, making it a much more powerful technique than the existing methods. The new method is expected to benefit EXAFS users covering all disciplines. Also, it is anticipated that the current work to be the motivation and inspiration to the further efforts. [ABSTRACT FROM AUTHOR]

Abstract To fight against diabetes mellitus, from which more than 400 million people suffer in the world, the patients have to puncture their fingers 4–5 times a day for the blood glucose level checks when using a glucometer, causing invasive pain and the risk of infection. Therefore, non-invasive method has been urged for blood glucose monitoring, among which the mid-infrared spectroscopy (Mid-IR) response of interstitial fluid was found to be promising. However, despite the prolonged effort, the accuracy still falls below the FDA's requirement. To break this barrier which lasted for almost three decades, we discovered the finger contact pressure playing a critical role during the measurement, where the Mid-IR reading could be affected significantly by a small change of the finger posture. In addition, the Mid-IR absorption level was also found to be highly associated with individual, revealing the necessity of adjusting the calibration correlation for each patient. By imposing a certain contact pressure monitored by a pressure transducer, we were able to achieve over 95% certainty from the Mid-IR measurement of glucose concentration and 100% comparability to the "true" glucose concentration for the first time, which was mainly attributed to the morphological change of finger tissue under pressure. The previous works resulted in only about 70% accuracy on average, barely hitting 80 + %, whereas ours reaches 95%, finally exceeding the requirement of FDA. Graphical abstract fx1 Highlights • the first study of the impact of contact pressure. • indicate the significance of contact pressure. • achieve 95% certainty and exceed FDA's requirement. [ABSTRACT FROM AUTHOR]

Bulk aluminum nitride (AlN) crystals with different polarities were grown by physical vapor transport (PVT). The structural, surface, and optical properties of m-plane and c-plane AlN crystals were comparatively studied by using high-resolution X-ray diffraction (HR-XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Temperature-dependent Raman measurements showed that the Raman shift and the full width at half maximum (FWHM) of the E2 (high) phonon mode of the m-plane AlN crystal were larger than those of the c-plane AlN crystal, which would be correlated with the residual stress and defects in the AlN samples, respectively. Moreover, the phonon lifetime of the Raman-active modes largely decayed and its line width gradually broadened with the increase in temperature. The phonon lifetime of the Raman TO-phonon mode was changed less than that of the LO-phonon mode with temperature in the two crystals. It should be noted that the influence of inhomogeneous impurity phonon scattering on the phonon lifetime and the contribution to the Raman shift came from thermal expansion at a higher temperature. In addition, the trend of stress with increasing 1000/temperature was similar for the two AlN samples. As the temperature increased from 80 K to ~870 K, there was a temperature at which the biaxial stress of the samples transformed from compressive to tensile stress, while their certain temperature was different. [ABSTRACT FROM AUTHOR]

An optical blackbody is an ideal absorber for all incident optical radiation, and the theoretical study of its radiation spectra paved the way for quantum mechanics (Planck's law). Herein, we propose the concept of an electron blackbody, which is a perfect electron absorber as well as an electron emitter with standard energy spectra at different temperatures. Vertically aligned carbon nanotube arrays are electron blackbodies with an electron absorption coefficient of 0.95 for incident energy ranging from 1 keV to 20 keV and standard electron emission spectra that fit well with the free electron gas model. Such a concept might also be generalized to blackbodies for extreme ultraviolet, X-ray, and γ-ray photons as well as neutrons, protons, and other elementary particles. [ABSTRACT FROM AUTHOR]

An abstract of the article "Modelling the cAMP pathway using BioNessie, and the use of BVP techniques for solving ODEs," by Xu Gu, David Gilbert, Des Higham, and Miles Houslay is presented.

P-glycoprotein (P-gp) exports a broad range of dissimilar compounds, including drugs, lipids, and lipid-like molecules. Because of its substrate promiscuity, P-gp is a key player in the development of cancer multidrug resistance. Although P-gp is one of the most studied ABC transporters, the mechanism by which its substrates access the cavity remains unclear. In this study, we perform coarse-grained molecular dynamics simulations to explore possible lipid access pathways in the inward-facing conformation of P-gp embedded in bilayers of different lipid compositions. In the inward-facing orientation, only lipids from the lower leaflet access the cavity of the transporter. We identify positively charged residues at the portals of P-gp that favor lipid entrance to the cavity, as well as lipid-binding sites at the portals and within the cavity, which is in good agreement with previous experimental studies. This work includes several examples of lipid pathways for phosphatidylcholine and phosphatidylethanolamine lipids that help elucidate the molecular mechanism of lipid binding in P-gp. [ABSTRACT FROM AUTHOR]

The ambient stability of α-FAPbI3 perovskite remains one of the biggest barriers to its commercialization, despite many attempts to enhance its lifetime. Due to the difficulties in experimentally investigating the transition kinetics, numerical simulation was performed. Surprising results were uncovered that the unstable α phase could be maintained in ambient conditions under compression, caused by the reduced Gibbs free energy of this phase. By analysing the transition rate, the detailed kinetic parameters have also been obtained, enabling us to construct a more complete phase map as a function of temperature and stress, offering a possible path towards stable high PCE perovskite solar devices, which opens an unprecedented avenue in perovskite solar cell research, and will hopefully be of intrinsic interest to the broad materials research community as well. [ABSTRACT FROM AUTHOR]

Understanding the inversely correlated series resistance ( R s ) and parallel resistance ( R p ) remains a challenge. Here we report that the variation of R s and R p is inversely related through the morphology of the donor and acceptor interface in CuPc organic solar cells, when comparing the bilayer structure and bulk heterojunction structure. It was also found that the charge carrier concentration near the donor–acceptor interface plays an important role in the relationships of R s and R p under fixed interfacial morphology, which was verified by the change of V oc . The inversely correlated R s and R p contributes to the improvement of the fill factor, and in turn the power conversion efficiency. [ABSTRACT FROM AUTHOR]

Ultra-high-speed (UHS) surface-mounted permanent-magnet synchronous motors (SPMSMs) are widely used for driving air compressors. UHS SPMSMs can suffer from high stator iron loss and rotor eddy current loss due to their high rotational speed and changes in the magnetic flux density when loading. Since these losses do not have a linear trend but change according to the motor design parameters, mathematical models cannot always predict them. This study aims to design UHS SPMSMs based on a kriging surrogate model that takes into account the stator iron loss and rotor eddy current loss. Since the kriging surrogate model is highly predictive for nonlinear inputs, it is the perfect candidate to take into account the stator iron loss and rotor eddy current loss. The design proposed in this study allowed to minimize the size and losses of a motor that satisfied the power specification. [ABSTRACT FROM AUTHOR]

For many years, people believed that in conventional x-ray crystallography one can only record the scattering intensities but not the phases. In order to study structures at the atomic scale, one has to use multibeam measurement or to rely on additional knowledge such as bonding length and to fit the intensity data by trial structure models. In this letter, however, we show that the phases are in fact hidden in the intensity data and can be recovered by studying the peak shoulders. To demonstrate, the x-ray diffraction data of aluminum powder were used to recover the phases and to reconstruct the electron density map. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Abstract: Organic solar cells (OSCs) have been under intensive studies, due to their attractive properties such as large scale, low cost, lightweight. However, their short lifetime, compared with the inorganic counterparts, has placed a severe restriction on the potential applications. To reveal the cause of the short life, here we report the finding of two distinguishable degradation mechanisms, from a typical organic/polymeric solar cell, based on polymer blend of regioregular poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester, fabricated on indium tin oxide-coated glass substrate. The first mode is associated with a localized failed area due to moisture encroachment, where the confronted areas are either completely dead or still 100% functioning. The second mode was found to be related to a mild decrease in power conversion efficiency (PCE) and was induced by a possible interfacial passivation occurred at the organic/cathode interface, due to the presence of residual oxygen, moisture and other impurities. The simulation results agree well with our experimental findings in showing that the degradation due to the localized moisture encroachment may be delayed by encapsulating the OSCs with desiccant. The degradation due to the interfacial passivation could be eliminated by the removal of low work function cathode at the sacrifice of PCE. [Copyright &y& Elsevier]

Abstract: An easy method is reported for fabricating a stable superhydrophobic coating made from a composite comprising carbon nanotubes and a fluoroplastic such as polytetrafluoroethylene or perfluoroalkoxy resin (Teflon® PFA). The superhydrophobic coatings with hierarchical structure characteristics are fabricated by a spray coating technique using an environmentally friendly aqueous dispersion containing carbon nanotubes and perfluoroalkoxy resin. Coatings with a contact angle of 153.1±2° and a sliding angle less than 5° are stable under much stress conditions, i.e., either soaking in concentrated hydrochloric acid and concentrated sulfuric acid, or attacking with extreme-pH or ionic-strength solutions. Both the contact angle and sliding angle can be tuned simply by changing the carbon nanotube loading. To further the understanding of the formation of superhydrophobicity, we investigated both the formation of the nano/microscale structures and their effects. [Copyright &y& Elsevier]

Abstract: We studied temperature-dependence of electroluminescence (EL) in fluorescent dye-doped and undoped organic light-emitting devices. Results show that the EL efficiency of the fluorescent dye-doped devices increases substantially with rising temperatures, as opposed to the dramatic decrease in EL efficiency of the undoped devices. Our experimental results demonstrate directly that thermally activated exciton diffusion is responsible for the reduced luminescence efficiency of the undoped devices at higher temperatures. However, in the doped devices, EL spectra show that excitons are effectively localized onto the guest molecules, which prevents them from being quenched by randomly distributed nonradiative recombination sites and from exciton–exciton annihilations during thermally activated diffusion, resulting in an enhanced EL efficiency at elevated temperatures. [Copyright &y& Elsevier]

This article is a critical review of computational techniques used to model, analyse and simulate signalling networks. We propose a conceptual framework, and discuss the role of signalling networks in three major areas: signal transduction, cellular rhythms and cell-to-cell communication. In order to avoid an overly abstract and general discussion, we focus on three case studies in the areas of receptor signalling and kinase cascades, cell-cycle regulation and wound healing. We report on a variety of modelling techniques and associated tools, in addition to the traditional approach based on ordinary differential equations (ODEs), which provide a range of descriptive and analytical powers. As the field matures, we expect a wider uptake of these alternative approaches for several reasons, including the need to take into account low protein copy numbers and noise and the great complexity of cellular organisation. An advantage offered by many of these alternative techniques, which have their origins in computing science, is the ability to perform sophisticated model analysis which can better relate predicted behaviour and observations. [ABSTRACT FROM AUTHOR]

Maternal metabolism dysregulation during pregnancy predisposes offspring to major diseases, including hypertension, in later life, but the mechanism involved remains to be fully elucidated. A high-fat-diet (HFD) pregnant rat model was used to investigate whether excessive intrauterine lipid exposure was associated with elevated blood pressure in offspring and increased levels of leptin, an important biomarker and mediator of vascular dysfunction and hypertension. We found that gestational hyperlipidemia predisposed offspring to blood pressure elevation and sustained increases in leptin levels with no difference in body weight in the rat model. Increased leptin expression and leptin promoter hypomethylation were found in adipose tissues of HFD-exposed offspring. The treatment of mesenchymal stem cells with free fatty acids during adipogenic differentiation resulted in increased leptin expression, accompanied by leptin promoter hypomethylation. In addition, we also followed up 121 children to evaluate the association between maternal triglyceride levels and offspring blood pressure. Consistent with the animal study results, we observed elevated serum leptin levels and blood pressure in the offspring born to women with gestational hypertriglyceridemia. Our findings provide new insights that maternal hyperlipidemia is associated with elevated blood pressure in offspring and is associated with increases in leptin levels through epigenetic memory. [ABSTRACT FROM AUTHOR]

As a major step forward in machine learning, generative adversarial networks (GANs) employ the Wasserstein distance as a metric between the generative distribution and target data distribution, and thus can be viewed as optimal transport (OT) problems to reflect the underlying geometry of the probability distribution. However, the unequal dimensions between the source random distribution and the target data, result in often instability in the training processes, and lack of diversity in the generative images. To resolve the challenges, we propose here a multiple-projection approach, to project the source and target probability measures into multiple different low-dimensional subspaces. Moreover, we show that the original problem can be transformed into a variant multi-marginal OT problem, and we provide the explicit properties of the solutions. In addition, we employ parameterized approximation for the objective, and study the corresponding differentiability and convergence properties, ensuring that the problem can indeed be computed. [ABSTRACT FROM AUTHOR]

To resolve the issue of which of the “indium migration” model and the “unstable AlQ3 cationic” model plays a more important role in luminescence degradation of organic light-emitting devices, we investigated the effect of the device structures on device operational stability. The results show that alterations in device layer structures can significantly affect the device operational stability, although they do not appear to noticeably change the magnitude of indium migrations. This suggests that the indium migration model may not play a dominant role in device degradation. On the other hand, the change in device stability with the alteration in the device structures can be plausibly explained by the unstable AlQ3 cationic model. [ABSTRACT FROM AUTHOR]