The flat nature of the device lowers parasitic capacitance, increasing charging energy EC. Our design also eases geometric restrictions and minimizes output channel separation. As a result we measure a visibility of up to 86% and a splitting efficiency of up to 62%. This will pave the way towards near unity efficiencies, long distance splitting, and post-splitting electron manipulation.Generation and manipulation of quantum entangled electrons is an important concept in quantum mechanics, and necessary for advances in quantum information processing; but not yet established in solid state systems. A promising device is a superconductor-two quantum dots Cooper pair splitter. Early nanowire based devices, while efficient, are limited in scalability and further electron manipulation. We demonstrate an optimized, high efficiency, CVD grown graphene-based Cooper pair splitter. Our device is designed to induce superconductivity in graphene via the proximity effect, resulting in both a large superconducting gap Δ = 0.5 meV, and coherence length  A source of quantum entangled particles is essential to quantum information processing145791011121314μeV. Moreover the Cooper pairs tunnel directly from the Al wire into the quantum dot pinning the superconducting gap Δ and superconducting coherence length ξ to that of Al. These factors adversely affect the CPS efficiency of the device - only an efficiency up to 10% has been reported. In our work we design the sample to utilize the two dimensional and highly crystalline nature of graphene thus improving on all the relevant parameters required to achieve a high CPS efficiency. As a result, we see CPS efficiency that is up to 6 times greater than the previous work. Moreover, we predict that by using ultra-clean graphene devices of the same design, near unity efficiency can be achieved.Graphene is a single layer, crystalline sheet of carbon with hexagonal structure leading to a gamut of unique electronic properties which would contribute well to a CPS device1617I) to the background current due to two electron processes (IBG) is α depends exponentially on the superconducting coherence length ξ and the separation of the normal-metal output channels Δr according to the relation: α = (sin(kFΔr)/(kFΔr))2exp(−2Δr/πξ). The variable EC: γ is the level resonance width, which is related to the tunneling rate, and varies with the gate voltages. We tune the design parameters to maximize α and ξ while keeping Δ large. Moreover, the device is patterned into a true Y-shape  resulting in a large EC. In our Y-shape Cooper pair splitter we achieve a 100% larger value for α and a full order of magnitude larger kF is similar in both devices). Maximizing these variables allows us to find a gate region where the splitting visibility is up to 86% and an efficiency that is 6 times more efficient than previously demonstrated.The ratio between the current due to Cooper pair splitting  normal metal leads. Finally, Lead (Pb) with a sticking layer of Palladium (Pd) is used to induce superconductivity in the graphene25In a step further, we move away from the conventional method of mechanically exfoliated graphene as it has many of the same drawbacks as the nanowire based samples. Such as: the unpredictable size and location of the graphene crystals requiring that each device must be designed and aligned individually, and the small average size of the exfoliated crystals which places limits on the device complexity. Recent advances in growing macroscopic sized sheets of high quality graphene using Chemical Vapor Deposition (CVD)212223r, is 140 nm. The central lead (made from graphene) acts as the superconductor (2528μV) and a frequency of 447 Hz is applied to the central lead, with a possible DC bias offset. Currents through the right and the left channels are measured simultaneously. The channels can be controlled individually via the side-gates, or simultaneously via the heavily doped substrate which acts as a global back gate.The sample is patterned into a Y-shaped junction to minimize separation between the normal metal channels . The disSiO2/Si are formed by defects, the Coulomb peaks are irregularly spaced. However, we estimate that the quantum dot charging energy EC is around 5 meV, which is greater than the energy gap of Pb (1.2 meVEC ≫ Δ is required.) Having the superconducting contact in the plane of the quantum dot 0.5l = 60 nm (obtained from bulk graphene resistance), giving us a minimal coherence length of ξ = 199 nm. To contrast, the literature value for the superconducting coherence length of pure Lead (Pb)ξPb0 = 83 nm: considerably less than our lead separation Δr. In fact, our Pb film is not pure; the lower mean free path would suppress ξPb0 by at least a factor of 2. Using ξPb0 instead of ξ, but keeping all other parameters same we would see a suppression of α by a factor of 2 for the case of pure Pb, and more than 6 for the realistic case.Initial characterization measurements are presented in b 1.2 meV30. (SincQDL) and Right (QDR) channels via the side gates. Grounding the back gate ensures that the charged carriers in bulk region of graphene are electrons as the Dirac point in unannealed graphene is consistently shifted to large negative voltages. All data from this point on are taken at zero DC bias. IL through QDL . Several Coulomb blockade resonances can be seen for both quantum dots. The difference in efficiencies for a given quantum dot of the side gates (as well as the back gate) scales approximately with the distance of the gate to the channel constrictionVGL and VGR results in a greater variability of the quantum dot tunneling barriers increasing the tunability of γ.Grounding the back gate for stability, we now individually control the quantum dots associated with the Left  when QDR (QDL) is moved directly off-resonance. The QDR background current IBGR = 24.7 pA was calculated by taking the average of IR for 1.51 < VG < 1.56 V and 1.71 < VG < 1.76 V  for the peak studied); that is ΔI = IPeak − IBG. This gives us ΔIR = 0.148 nA and ΔIL = 0.172 nA. Hence we find that the CPS current does not have the same value for both channels. We attribute this imbalance to the finite interdot coupling present in our device which makes it possible for the split electrons to tunnel through the graphene from the Right to the Left quantum dot1214QDL featured much weaker tunneling barriers than QDR as evidenced by the higher background current; meaning, the time the electron would spend in QDL would be much shorter than in QDR.For comparison, the < 1.76 V . While,  −1.14 V  inset. WkF is inaccessible and our dataset is not sufficient enough to precisely extract the level resonance widths γL and γR. As an estimate, the upper value for γ is bound by Δ while the lower bound comes from the minimum acceptable EC. Giving us a range 100 μV ≤ γL ≤ 400 μV. With the total measured ratio of splitting current to background current 5 cm−1 ≤ kF ≤ 2 × 105 cm−1. The possible values of kF are an order of magnitude lower than expected in normal graphene. We speculate that this discrepancy may come with the lower quasiparticle population density in superconducting graphene compared to normal graphene. . For the resonance peak presented in ηRight = 0.86 and ηLeft = 0.51. The lower visibility of QDL is due to the high background current. Finally we calculate the splitting efficiency of our system by comparing the CPS current to the total current in the system: s = (ΔIR + ΔIL)/(IPeak Left + IPeak Right). We find the efficiency s = 0.62. This is significantly higher than previously reported in graphene, but much lower than needed to observe a violation of Bells inequality35We calculate the visibility of the Cooper pair splitting by finding the fraction of the CPS current relative to the total current: QDR while sweeping the Left channel gate. VGR) for resonance peaks from VGL) such that the absolute value of the current at the Apex is maximal. We now study how the splitting signature evolves as we sweep QDL through a resonance peak while keeping QDR at the positions denoted by the marks in Previous works showed that the CPS efficiency was not maximum directly at the top of the quantum dot Coulomb resonance, but instead slightly off peak10BC ~770 mT, and therefore reversibly eliminates superconductivity in our devicesIR while QDL is swept through several resonances at zero magnetic field for a sample different than that in IR is enhanced when QDL is on resonance.  of apparent .ξ (while maintaining large gap Δ) and ensuring that ξ is larger than the QD separation Δr. While we do not have direct evidence that the central graphene region is superconducting, the observation of a zero-bias gap in the Coulomb blockade in strong indirect evidence. Assuming that the splitting effect is due to Lead (Pb) alone leads to a superconducting coherence length that is much smaller than the lead separation, making the observed high efficiency inaccessible. Moreover, considering that the mean free path is estimated at 60 nm, and the central graphene region prior to the quantum dots is about 150 nm long, the Cooper pairs would have decohered by the time they reached the QDs if the graphene was in the normal state. In addition, having the superconductor in plane with the quantum dots, as opposed to directly over them, we greatly increase the quantum dot charging energy EC. As a result, when both quantum dot channels are on resonance we see a Cooper pair splitting current that is up to 62% of the total current through the device.  becoming superconducting via proximityξ in graphene is suppressed due to the material being un-annealed. Simply by increasing the complexity of our device processing by adding a cleaning step or encapsulating the graphene, ξ can be increased by as much as an order of magnitude. This would dramatically increase the efficiency of future devices; or, alternatively achieve Cooper Pair splitting distances of more than a micron. Unlike nanowire based devices, the CVD graphene allows for more expanded complexity: moving towads measurements and manipulation of the spins of the split electron pairs, and paving a way towards applications.It is clear that in our sample design the superconducting coherence length μm, which is much larger than the critical area of the device of a few μmSi/SiO2 wafer using a standard FeCl3, PMMA transfer method2125Graphene is grown on Copper via Chemical vapor deposition method with  and domain sizes of ~100 π filters for low frequencies, followed by Copper powder filters for high frequencies, with an overall cutoff frequency of 10 kHz. An AC voltage of (350 μV) and a frequency of 447 Hz is applied to the central lead, with a possible DC bias offset. Currents through the right and the left channels are measured simultaneously via Ithaco 1211 preamplifiers. The channels can be controlled individually via the side-gates, or simultaneously via the heavily doped substrate which acts as a global back-gate.Measurements are taken in a Oxford Instruments MX-100 dilution refrigerator at the base temperature of 100 mK using lock-in technique. The sample is isolated from the environment by a Copper can, and filtered using RC How to cite this article: Borzenets, I. V. et al. High Efficiency CVD Graphene-lead (Pb) Cooper Pair Splitter. Sci. Rep.6, 23051; doi: 10.1038/srep23051 (2016).


Innovative methods producing transparent and flexible electrodes are highly sought in modern optoelectronic applications to replace metal oxides, but available solutions suffer from drawbacks such as brittleness, unaffordability and inadequate processability. Here we propose a general, simple strategy to produce hierarchical composites of functionalized graphene in polymeric matrices, exhibiting transparency and electron conductivity. These are obtained through protein-assisted functionalization of graphene with magnetic nanoparticles, followed by magnetic-directed assembly of the graphene within polymeric matrices undergoing sol–gel transitions. By applying rotating magnetic fields or magnetic moulds, both graphene orientation and distribution can be controlled within the composite. Importantly, by using magnetic virtual moulds of predefined meshes, graphene assembly is directed into double-percolating networks, reducing the percolation threshold and enabling combined optical transparency and electrical conductivity not accessible in single-network materials. The resulting composites open new possibilities on the quest of transparent electrodes for photovoltaics, organic light-emitting diodes and stretchable optoelectronic devices. Transparent and electrically conducting flexible films are in high demand but production can be both time-consuming and expensive. Here, the authors report a method for assembling modified graphene flakes in controlled distributions within polymeric matrices by use of magnetic fields. However, bulk materials containing mixtures of the conductive elements and the flexible matrix present the advantage to provide more mechanical integrity over sandwich or layered structures, as well as the possibility to create more complex three-dimensional (3D) circuits. In addition, direct ink writing or 3D printing techniques can be applied to build on-demand materials with inks containing both the transparent support and the conductive elements78−1 for films of 1 μm thicknessThe increasing demand for optoelectronic tools from tissue-compatible biomedical devices for health monitoring to indium–tin-oxide-free electrodes for flexible solar cells has recently stimulated the search for cost-effective materials with comparable performance, but improved flexibility to replace the commonly used stiff and brittle components1235−1 in cellulose nanofibrils aerogel membranes while maintaining 90% in transparency and 5% in strain at rupture−1 in 81% transparent polyethylene terephthalate-congo red single-wall carbon nanotube composites1819202223242530Recent efforts have focused on employing conductive anisotropic particles exhibiting high aspect ratio to reduce the amount of opaque material needed to reach the percolation threshold in the composite11121314One enticing approach to further decrease the amount of conductive particles needed to achieve the percolation threshold is to fabricate hierarchical composites exhibiting multiple percolating networks at different length scales32In this study, we describe a simple processing route to fabricate transparent and conducting polymer-based composite films using external magnetic fields to assemble magnetized graphene flakes into hierarchical networks of predefined features. Using virtual magnetic moulds, transparency is obtained by locally concentrating the dark conductive flakes into continuous networks. When large micrometric mesh sizes are used as moulds, such control is achieved over areas spanning over several centimeters, resulting in double-percolating hierarchical networks. In addition to spatial control, tuning the orientation of the functionalized graphene flakes within the microscopic pattern further enhances the electrical conductivity. By carefully engineering the mesh size of virtual magnetic moulds, we demonstrate how this new strategy can lead to transparent, electrically conducting polymer–graphene composites with great potential for applications in advanced compliant optoelectronics.Hydrophilic magnetically responsive reduced graphene oxide (m-rGO) flakes are synthesized through decoration of exfoliated micrometric graphene oxide nanosheets (GO) with 10 nm superparamagnetic iron oxide nanoparticles . The at37xy-plane is achieved by applying a horizontally rotating magnetic field394041z axis  compared with a horizontal configuration is the first evidence of the successful alignment of the flakes in the intended direction  patterns through magnetic manipulation of diluted dispersions enables the creation of hierarchical double-percolating networks . At the ϕi is calculated from the density of the m-rGO flakes and the coverage of iron oxide nanoparticles and BSA . Such a small resolution has not yet been reported in stretchable and transparent strain sensors used for health-monitoring devices where high strains, typically up to 300%, is the main property targeted5051A possible further advantage of the proposed strategy is that of allowing the production of conductive and stretchable functional composites serving as strain sensors of high precision. Indeed, thanks to the intrinsic flexibility of polymers, we conducted in-plane confined compression experiments on polydimethylsiloxane substrates covered by the gelatin m-rGO film while recording the change in electrical conductivity  were dissolved in 25 ml water and vigorously stirred. After heating to 60 °C, 10 ml NaOH solution at 2 wt% was added with 250 mg of hexadecylpyridinium bromide (Fluka).Spherical magnetite nanoparticles were synthesized by co-precipitation of FeSOA measure of 18 ml of the GO stock solution was mixed with 2 ml of 0.5 wt% of the BSA protein (Sigma-Aldrich). In a following step, this suspension was stirred with 250 μl of 4.4 wt% SPIONs suspension for 1 h to allow for the physical adsorption of the SPIONs at the surface of the graphene oxide sheets through interactions with the BSA. Volume of 100 μl of reducing agent hydrazine monohydrate (Sigma-Aldrich) was added at 80 °C for 20 h under continuous stirring. After cooling to room temperature, the mixtures were kept at 4 °C.z axis, whereas the samples with biaxially aligned flakes were obtained by rotating the magnetic field on the x–y plane. The samples were afterwards cooled down to room temperature and dried for 24 h in ambient conditions to consolidate the gelatin and fix the designed architecture  aqueous solution of 20 wt% gelatin  was mixed with the corresponding volume of the suspension of m-rGO in water and stirred at 55 °C. For the experiments with controlled orientation, the mixture was cast into small polyethylene moulds. A static vertical magnetic field of 50 mT was used for the uniaxial alignment of the graphene flakes along the itecture . Samplesitecture . To demoitecture . The welPAMPS hydrogel was synthesized according to a modified processCharacterization of the m-rGO and the composites film is detailed in the The data that support the findings of this study are available from the corresponding authors on request.How to cite this article: Le Ferrand, H. et al. Magnetic assembly of transparent and conducting graphene-based functional composites. Nat. Commun. 7:12078 doi: 10.1038/ncomms12078 (2016).Supplementary Figures 1-8, Supplementary Tables 1-2, Supplementary Note 1, Supplementary Discussion, Supplementary Methods and Supplementary References


Hippocampi were collected for analysis of mRNA of ERα and BDNF, protein levels of ERα, p-TrkB, p-src, and cleaved caspase 3 (c-caspase-3) post-HI. Our results demonstrate that: (1) HI differentially induces ERα expression in the hippocampus of the female versus male neonate, (2) src and TrkB phosphorylation post-HI is greater in females than in males after 7,8-DHF therapy, (3) src and TrkB phosphorylation post-HI depend on the presence of ERα, and (4) TrkB agonist therapy decreases the c-caspase-3 only in ERα+/+ female mice hippocampus. Together, these observations provide evidence that female-specific induction of ERα expression confers neuroprotection with TrkB agonist therapy via SFK activation and account for improved functional outcomes in female neonates post-HI.Male neonate brains are more susceptible to the effects of perinatal asphyxia resulting in hypoxia and ischemia (HI)-related brain injury. The relative resistance of female neonatal brains to adverse consequences of HI suggests that there are sex-specific mechanisms that afford females greater neuroprotection and/or facilitates recovery post-HI. We hypothesized that HI preferentially induces estrogen receptor α (ERα) expression in female neonatal hippocampi and that ERα is coupled to Src family kinase (SFK) activation that in turn augments phosphorylation of the TrkB and thereby results in decreased apoptosis. After inducing the Vannucci’s HI model on P9 (C57BL/6J) mice, female and male ERα wild-type (ERα Female neonate brains are more resistant to the effects of hypoxia-ischemia (HI). We report a novel mechanism that involves the female-biased induction of ERα expression in the hippocampus post-HI, coupled to activation of a cytoplasmic kinase (src) and increased TrkB phosphorylation in the presence of a TrkB agonist. Thus, the enhanced TrkB receptor signaling resulting from this crosstalk mechanism confers decreased programmed cell death in response to TrkB agonist treatment in female versus male subjects. These results clearly demonstrate a role for ERα in enhancing TrkB activation and may account for the relative resistance of the female neonate brain to HI.Perinatal asphyxia resulting in hypoxia-ischemia (HI)-related brain injury leads to severe, life-long morbidities in thousands of neonates and children born in the U.S. each year . The phy2) therapy is terminated  plays an essential role in the sexual differentiation of neurons in mammalian brain  and incrrminated . In adulrminated . HoweverThe development and survival of the mammalian nervous system is largely dependent on the existence of soluble neurotrophic factors. One example is BDNF whose function is primarily mediated through the high-affinity cell-surface receptor TrkB. In the CNS, TrkB is widely expressed in neurons and contributes to diverse biological processes including neuronal survival and neuronal differentiation . Followi2 therapy induces phosphorylation of TrkB in the adult mouse hippocampus the response is absent in ERα−/− mice  antibody, goat serum, and 7,8-DHF were obtained from Sigma-Aldrich. Rabbit polyclonal anti-phospho-src (Y418), rabbit polyclonal anti-phospho-TrkB (Y515) and rabbit anti-cleaved caspase 3 for immunohistochemistry were purchased from Abcam. Rabbit polyclonal phospho-TrkB (Y705) for immunoblotting was obtained from Signalway Antibody. Rabbit polyclonal anti-TrkB for immunoblotting and mouse monoclonal anti-neuronal nuclei (NeuN) for immunohistochemistry were obtained from EMD Millipore. Rabbit monoclonal anti-src for immunoblotting and rabbit polyclonal anti-cleaved caspase 3 (Asp 175) were obtained from Cell Signaling. Rabbit anti-ERα (MC-20) for immunoblotting was obtained from Santa Cruz Biotechnology. Mouse anti-β-actin was obtained from Developmental Studies Hybridoma Bank. Vectashield mounting media with DAPI was purchased from Vector Laboratories. Goat anti-mouse AlexaFluor 488-conjugated IgG, goat anti-rabbit AlexaFluor 546-conjugated IgG, PlatinumTaq Master Mix, Trizol, Purelink, PCR master mix, TaqMan probes for ERα, ERβ, BDNF and β-actin, trypsin-EDTA, HBSS, horse serum, penicillin/streptomycin, neurobasal medium, and B-27 medium were obtained from Life Technologies.Guide for the Care and Use of Laboratory Animals using protocols reviewed by the Institutional Animal Care and Use Committee at our institution.All procedures on animals were carried out in adherence with the NIH +/−) C57BL/6J mice were bred and pups were sexed and genotyped within 9 d of birth. Genotypes were determined by PCR of genomic DNA from finger or toe clippings. Clippings were heated at 95°C for 45 min in 50 mm NaOH and neutralized with equal volume of 1 m Tris, pH 6.8. One microliter of this DNA solution was added to 19 μL of the following: 0.25 μM of primers for the ERα gene, 1× GoTaq Buffer (Promega), 0.2 mm each deoxynucleotide (Promega) and 8 U Platinum Taq (Life Technologies). PCR was performed for 30 cycles as follows: 95°C for 3 min, denaturation at 95°C for 30 s, annealing at 58°C for 30 s (ERα−/− PCR1) or 51°C for 30 s (ERα−/− PCR2), and elongation at 72°C for 1 min. PCR products were separated electrophoretically on an ethidium bromide-containing 2% agarose gel and visualized under UV illumination.ERα heterogeneous . Under a surgical microscope , a midline skin incision was made and the muscle overlying the trachea visualized. The left common carotid artery was freed from the carotid sheath by blunt dissection, electrically cauterized, and cut. The incision was injected with 0.5% bupivacaine and closed with a single 6.0 silk suture. Animals were returned to their dams and monitored continuously for a 2 h recovery period. To induce unilateral ischemic injury, the animals were placed in a hypoxia chamber (BioSpherix) equilibrated with 10% O2 and 90% N2 at 36°C for 50 min. After HI, animals were returned to their dams and monitored for pain and discomfort every minute for the first 30 min, every 30 min for the next 2 h, and then daily until sacrificed. This is a well-characterized model of neonatal HI and results in reproducible brain injury ipsilateral (IL) to the electrocauterized left common carotid artery diluted in 0.1 m PBS at 10 min after HI. Subsequently, mice were given a daily dose for 2 d after HI. The HI-vehicle control groups received an equal volume of PBS at the same time points.in situ. For perfusion fixation, the animals were anesthetized with isoflurane as described and transcardially perfused with 4% paraformaldehyde and decapitated. After postfixation of the brains in 4% paraformaldehyde overnight, brains were stored in a 30% sucrose/PBS solution for 48 h and then sectioned (35μm thick) on a freezing sliding microtome (Leica SM2000R). The brain sections were then cryoprotected in an antifreeze solution for storage at −20°C.On day 3 (P12) or day 1 (P10) post-HI, animals were either decapitated for collection of fresh tissue or perfusion fixed ++ (0.1% Triton X-100 and 3% goat serum in 0.1 m TBS) for 30 min at 37°C. Slices were double-stained with anti-MAP2 (1:500) and anti- p-TrkBY515 (1:100) or anti-cleaved caspase 3 (1:200) and anti-NeuN (1:200), or anti-p-srcY418 (1:250) and anti- NeuN (1:200), for 1 h at 37°C and then overnight at 4°C. After washing with TBS (3 × 10 min), brain sections were incubated for 1 h at 37°C with goat anti-rabbit AlexaFluor 488-conjugated IgG (1:200) and goat anti-mouse AlexaFluor 546-conjugated IgG (1:200) in TBS++. Following rinsing with TBS, the slices were mounted on slides using Vectashield mounting media with DAPI. Primary antibodies were eliminated in some slices to control for nonspecific secondary antibody staining. Slides were imaged with either a Nikon A1R-Si confocal microscope using a 20× objective or whole-brain images collected with a Zeiss epifluorescent microscope using a 5× objective and Stereo Investigator software (MBF Bioscience).After rinsing with 0.1M Tris-buffered saline (TBS), brain slices were incubated with TBSY515 staining, whole-brain images were imported into Image J software  at 1 d post-HI were quantified. The CL and IL hippocampi from two brains were harvested and pooled in order to achieve the adequate protein content. The tissues were homogenized and centrifuged at 2200 × g for 5 min at 4°C. The protein content was determined by the bicinchionic acid method (Pierce). The protein samples (50 μg) and pre-stained molecular mass markers in a SDS buffer were electrophoretically separated on 4–20% gradient SDS gels. The resolved proteins were electrophoretically transferred to a nitrocellulose membrane. After incubation in 5% nonfat dry milk in TBS for 1 h, the blots were probed with the anti-TrkB antibody (1:1000) and anti-p-TrkBY705 antibody (1:800); or anti-t-src (1:1000) and anti-p-srcY418 (1:800); or anti-ERα (1:500) and β-actin (1:2000); or c-caspase-3 (1:800) and β-actin (1:2000) overnight at 4°C. After rinsing with TBS, the blots were incubated with goat anti-rabbit horseradish peroxidase-conjugated secondary IgG (1:6000) or rabbit anti-mouse horseradish peroxidase-conjugated secondary IgG (1:6000) for 1 h. Bound antibodies were visualized using an enhanced chemiluminescence assay (Millipore or Biorad).The hippocampal protein expression of total TrkB, p-TrkB −ΔΔCT method  or a standard curve for the control gene (β-actin) was obtained by serial 1:10 dilution of the cDNA from the female CL hippocampus and the undiluted sample assigned a value of 1. Cycles to threshold values were analyzed using the System 7500 SDS software (Life Technologies). The calculated values were normalized to their corresponding β-actin values and expressed relative to the value for the female CL hippocampus.CL and IL hippocampi were freshly harvested and immediately placed on dry ice. Total RNA was extracted from single hippocampi using Trizol and a Purelink kit from Life Technologies. The amount of total RNA was determined from the optical densities measurements at 260 and 280 nm . The reverse transcription reaction (RT) was performed using SuperScript III reverse-transcription reagents and protocols from Life Technologies. Two micrograms of total RNA, random hexamers, oligdTs, dNTPS, and RT buffer were heated for 10 min at 65° for denaturation. First Strand Buffer, DTT, RNAase inhibitor, and the superscript reverse III transcriptase were then added and the samples heated up to 42°C for 1 h followed by 5 min at 95°C to inactivate the reverse transcriptase. The resulting cDNA samples were then diluted 1:10 with RNAase free water and stored at −80°C until use. For quantitative PCR (qPCR) amplification ∼20 ng of cDNA was used. Each reaction  for a single gene was done in duplicate and consisted of predesigned gene-specific primers and probes for ERα (Mn00433149_m1), ERβ (Mm00599821_m1), BDNF (Mm04230607_s1), or β-actin (Mm00607969_s1) and TaqMan Master Mix on a 96-well plate. PCR amplification was accomplished using an Applied Biosystem 7500 qPCR system (Life Technologies) running a standard amplification protocol . Relative gene expression was calculated by the 2Y705/f-TrkB, f-TrkB/β-actin, t-TrkB/β-actin, i-TrkB/β-actin, p-srcY418/t-src, and c-caspase-3/β-actin). The primary outcome variables were the immunoblot band density parameters from the IL side. The analyses were adjusted by including the corresponding CL side values as covariates in the model. Thus, in these figures we report the adjusted IL mean ± SEM. The main and interaction effects between factors were evaluated. p values were calculated from the corresponding F values of the main or interaction effects. The comparisons of the outcome parameters between males and females were made by constructing sliced contrast matrices of the corresponding two- or three-way interaction effects. Analogously, ANCOVA was conducted to evaluate the sex effect for HI treated subjects on BDNF and ERα expression levels. The results were presented using bar charts displaying the adjusted means and corresponding standard error bars. Analysis of variance was performed to evaluate the effects of sex and mutation status on the percentage change in the IL/CL ratio of hippocampal pTrkBY705 staining levels. All p values are two-sided and p<0.05 was used to define statistical significance. Statistical analyses were conducted using SAS software (SAS Institute) version 9.3 (Table 1).ANCOVA was used to evaluate the effect of sex, HI, and 7,8-DHF therapy on all immunoblot band density parameters   in both CL and IL hippocampi obtained from sham-operated and post-HI mice in both sexes. The sexually differentiated up-regulation of ERα prompted us to further investigate the role of ERα in TrkB phosphorylation both in ERα+/+ and ERα−/− mice.ERα mRNA and protein expression were increased in the ischemic cortex of ovariectomized adult female rats, but were unchanged in adult males in an MCAO model . Howeverctively) . ERβ mRNY705 3 d after sham operation. We could not detect any sex differences in hippocampal TrkBY705 phosphorylation between treatment groups in sham-operated neonatal mice . Similar to the results of p=0.028c; Y705 phosphorylation in mice 3 d post-HI was also detected regardless of the sex and 7,8-DHF therapy (p=0.0002d). There was also a significant sex and HI interaction (p=0.023e). This latter response is more robust in females than males and may account for the sexually differentiated neuroprotection observed with TrkB agonist therapy. We then sought to determine whether hippocampal ERα expression is required for TrkBY705 phosphorylation in neonatal mice post-HI or not, using ERα−/− mice.al mice A–C. SimiY515 expressions in both ERα+/+ and ERα−/− mice post-HI by immunostaining. Supporting our in vivo immunoblotting studies, semiquantitative analysis of pTrkB immunostaining revealed an ∼17% increase in the IL hippocampal pTrkBY515 immunoreactivity at 3 d post-HI in the hippocampus of both male and female ERα+/+ mice  and female (p = 0.00015g) ERα−/− mice compared with ERα+/+ mice . There was a statistically significant difference in f-TrkB levels between the female sham and HI animals, this difference did not persist in 7,8-DHF treated animals (p=0.01h). However, our results did show a statistically higher hippocampal t-TrkB expression in female IL hippocampus (adjusted for CL) post-HI compared with males (p = 0.01i), this significance did not hold in 7,8-DHF treated females post-HI. More importantly, there was no difference in hippocampal t-TrkB expression between males and females with 7,8-DHF therapy at 3 d post-HI. Thus, the sexually differentiated hippocampal TrkBY705 phosphorylation in response to 7,8-DHF therapy does not appear to be dependent on differential expression of TrkB subtypes post-HI.TrkB can exist in other isoforms that could affect its signaling capacity. The two dominant TrkB receptor isoforms expressed in the brain are full-length (f-TrkB) and truncated TrkB (t-TrkB). Presence of t-TrkB can prevent f-TrkB phosphorylation in male mouse mammary gland . In addi2 binding to nuclear ERα resulting in DNA binding at estrogen response elements in the BDNF promoter region resulting in differentially increased BDNF expression in females. However, in our experiments BDNF mRNA expression was not increased, but instead significantly decreased in female hippocampus at 3 d post-HI  in female IL hippocampus post-HI (p=0.045j) and (1.6-fold) after 7,8-DHF therapy (p = 0.001l) compared with males post-HI . In addition, TrkB agonist therapy mediated attenuation of c-caspase-3 levels observed in female ERα+/+ mice is abolished in the absence of ERα (p = 0.043°). Together, our data suggest that the sexually differentiated response to HI and HI + p-TrkB agonist therapy in the female neonate hippocampus is mediated by ERα and provides neuroprotection via facilitation of prosurvival cell signaling pathways downstream of TrkB phosphorylation. However, there were no differences detected in attenuation or exacerbation of the apoptosis when assessed by c-caspase-3 levels in male neonate hippocampus regardless of the TrkB agonist therapy or ERα status 1 d post-HI.TrkB signaling leads to activation of prosurvival pathways including PI3K/AKT, PLCγ-CaRas/MAPK . Thus, tpocampus A, right.−/− mice B–D at 1+/+ female mice hippocampus  HI differentially induces ERα expression in the hippocampus of the female versus male neonate, (2) src and TrkB phosphorylation post-HI is greater in females than in males after 7,8-DHF therapy, (3) src and TrkB phosphorylation post-HI depend upon the presence of ERα, (4) TrkB agonist therapy decreases the c-caspase-3 only in ERαpocampus . These o2 in adult rodents were dependent on ERα but not on ERβ after MCAO. It has also been reported that ERα is differentially increased in adult female cortex compared with males at the ischemia site after MCAO (2 in neonatal brains have not been studied. We report here that ERα expression is upregulated in the ischemic neonatal hippocampus in a sexually differentiated manner, with greater ERα mRNA and protein expression occurring in the female versus male neonate, in a manner similar to that previously reported in adult rodents at the ischemia site after MCAO (Using ERα and ERβ KO mice ter MCAO . Althougter MCAO , the invter MCAO . The mecter MCAO . In adulWe have examined the possibility that the ERα expression is linked to decreased neurodegeneration and improved neurological outcome via interactions of ERα with TrkB signaling. Neurotrophins, such as BDNF, play critical roles in neuronal survival, neurogenesis, and synaptic plasticity . Intrace−/− mice (−/− mice 3 d post-HI. These results clearly demonstrate that the hippocampal TrkB phosphorylation depends upon the presence of ERα. When coupled with the observation that ERα expression is greater in the female hippocampus post-HI, these findings provide strong evidence that the sexually differentiated pattern of phosphorylation of TrkB following HI and after TrkB agonist therapy is mediated by ERα. The hippocampal E2 action could be exerted through increased production of a TrkB ligand or through stimulation of intracellular signaling pathways following HI in neonatal brains (2 inducing increased production of intrinsic TrkB ligand via classical pathway cannot be held responsible for increased TrkB phosphorylation. Thus, we hypothesized that the crosstalk between the ERα and TrkB is through the cytoplasmic kinase signaling after rapid membrane ERα activation.Estradiol therapy has been shown to increase the hippocampal TrkB phosphorylation in adult mice, but this response is ablated in ERα−/− mice . We ther−/− mice . We founl brains . To testY705/Y706. In addition, the fact that TrkB immunoprecipitates with both src and fyn confirms a physical relationship between these kinases and TrkB (−/− mice. Thus, increases in ERα expression in female hippocampus could lead to increases in signaling through p-src, which could facilitate phosphorylation of TrkB and promote downstream anti-apoptotic signaling post-HI (One possible mechanism that can link the ERα with TrkB is that ERα can couple to the cytoplasmic SFKs through the membrane initiated signaling resulting in phosphorylation of the TrkB . Using mand TrkB . Our res post-HI .−/− mice hippocampus and 7,8-DHF therapy did not have any effects decreasing the apoptosis. In contrast, neither 7,8-DHF therapy nor ERα deletion changed c-caspase-3 expression in the male hippocampus. This could be the result of different apoptotic pathways present in the male hippocampus that may not be caspase dependent. Future studies are required to elucidate that relationship between sex-dependent cell death pathways and ERα-dependent neurotrophin signaling.The mechanisms underlying the sex differences in neonatal brains post-HI is unknown. Recent experiments into sex-dependent cell death pathways in neonates have led to a hypothesis that in females cell death occurs primarily through a caspase-dependent pathway, whereas in males it is secondary to PARP activation post-HI . GeneticTo our knowledge, this is the first study to reveal that hippocampal ERα signaling is integrated with TrkB signaling in a manner that it is more robust in neonatal females, potentially accounting for the sex differences seen after HI-related brain injury. We have shown that genetic deletion of ERα abolishes the sexually differentiated expression of p-TrkB in response to its agonist, 7-8, DHF, in neonatal mice post-HI. In addition, we demonstrated that there is a sex difference in the post-HI activation of p-src in neonatal hippocampus that is also ERα dependent. Thus, increased ERα signaling through src in female hippocampus that facilitates TrkB signaling resulting in decreased c-caspase-3 is a novel mechanism that could account for the sex differences in brain injury following HI in neonates. Better understanding of the mechanisms involved in female resistance to injury could lead to targeted therapies in neonates following hypoxic and ischemic encephalopathy.


About 6 million people search for health information on the Internet each day in the United States. Both patients and caregivers search for information about prescribed courses of treatments, unanswered questions after a visit to their providers, or diet and exercise regimens. Past literature has indicated potential challenges around quality in health information available on the Internet. However, diverse information exists on the Internet—ranging from government-initiated webpages to personal blog pages. Yet we do not fully understand the strengths and weaknesses of different types of information available on the Internet.The objective of this research was to investigate the strengths and challenges of various types of health information available online and to suggest what information sources best fit various question types.We collected questions posted to and the responses they received from an online diabetes community and classified them according to Rothwell’s classification of question types . We selected 60 questions  and the replies the questions received from the community. We then searched for responses to the same questions using a search engine and recorded theCommunity responses answered more questions than did search results overall. Search results were most effective in answering value questions and least effective in answering policy questions. Community responses answered questions across question types at an equivalent rate, but most answered policy questions and the least answered fact questions. Value questions were most answered by community responses, but some of these answers provided by the community were incorrect. Fact question search results were the most clinically valid.The Internet is a prevalent source of health information for people. The information quality people encounter online can have a large impact on them. We present what kinds of questions people ask online and the advantages and disadvantages of various information sources in getting answers to those questions. This study contributes to addressing people’s online health information needs. On average, about 6 million individuals in the United States search for health information on the Internet per day . This nuPeople look for health information on the Internet as patients or as caregivers . They loThe Internet provides users access to a myriad of health-related sources, such as government and professional organization websites, medical journals, mailing lists, articles, and online support groups . The IntIn this study, we compared how 2 frequently used sources of health information on the Internet—answers from other patients  and Internet search results —have unique advantages and disadvantages. We discuss implications for how online health information seekers can be further supported to receive high-quality information. Depending on the types of questions health information seekers have, search engines could provide more helpful resources than would online health communities, or vice versa. Identifying the most appropriate Internet health information resource is challenging for patients. We addressed this challenge by investigating what informative sources are most appropriate for the types of questions information seekers have.In 2013, the Pew Research Center found that 8 out of 10 health-related inquiries started with a search engine .” To this question, the top search result was a website containing information about oral and noninsulin injectable medications for diabetes. This website contained information on Byetta being a noninsulin medication but it lacked information on whether it could be consumed with metformin, which was part of what the question was asking.Some search results did not answer the questions at all. These results included information irrelevant to the questions with large amounts of text on the page, which would be overwhelming for lay users. The search results coded as not answering questions by both the nonclinical coder and clinician A presented extraneous information such as a class study guide, commercials for products, or a response to the question but not in a diabetes context. Some search results also did not include sources or citations from which the information was derived, thereby making the validity of the information questionable.Community responses for fact questions contained personal experiences, anecdotes, and assessment of information provided by other responders. The community responses also included reassurances and compliments to the poster, psychosocially supporting them. For instance, to the question “I am new to diabetes. I have noticed that my blood sug[a]r goes to 180–200 when I exercise. The more strenuous the exercise the higher the blood sug[a]r. Does anyone know why this happens?”, a poster responded: “Exercise is a form of stress on the body. Whenever you have stress, your liver secretes sugar. Even though it goes up during exercise, you may notice it dropping low after you are done. This does happen to me too, and I make sure to drink plenty of water while I work out.” This conversation describes how a community response answers a poster’s question while also providing personal experience with the problem and a way to resolve it based on the responder’s own method. This was the most critical difference between the search results and community responses. Another prevalent answer to posters’ questions was responders asking the posters to discuss their questions with their health care providers in case it was something that needed medical intervention. The responders also assessed the accuracy of other people’s responses. Responders also denied answering questions due to the liability of the community.Clinician A determined that 35/66 community responses answered fact questions. Similar to fact question search results, those community responses coded as not answering questions included general encouragement for the poster only , responses to conversations with other individuals involved in the post, or just responses that were clinically incorrect. Additionally, 37/66 of the community responses were both clinically relevant and clinically valid.Fact question community responses not only advised a poster to visit a health professional, but also provided suggestions about what should be discussed during this visit, referred posters to external resources, gave compliments and reassurances about the difficult time the poster was going through, and even alerted a poster to incorrect or dangerous information provided by other responders.Overall, community responses presented more information related to answering the question content than did the search results.Finally, we calculated the interrater reliability of clinicians A and B using Cohen kappa score. The overall kappa for fact questions was .46, indicating a weak level of agreement between the 2 clinicians . A more Search results of policy questions included diabetes management pages, blogs, stepwise instructions on how to solve a problem, and patient forums. However, not all answers were available within an article reached through a search result—often, the information was present  in the discussion or comments section of the page. Because these were how-to questions, the search results also led to different social media platforms such as Facebook, where other similar questions fully or partially answered the poster’s question. For instance, the question “hi i just checked my blood sugar and its 490 how can i get it down my vision is blurry? [sic]” leads to a Facebook type 1 diabetes page post discussing eyesight fluctuation for a 25-year-old with newly diagnosed type 1 diabetes. This post is not an exact answer to the poster’s query, but it partially explores the poster’s questions. Furthermore, the comments the Facebook post received could help the poster get his or her answer. Some results did not answer the questions asked.Our coding results indicated that a very low number of policy questions were answered through search results. Among the search results of policy questions, clinician A identified that 8/60 results correctly answered the questions. This coder also found that 8/60 search results were clinically relevant but 24/60 were clinically valid.A search engine does not directly answer “what or how should I do [something]?” questions. For instance, a person asking about how to lower blood sugar first thing in the morning, due to high early-morning numbers, is led to a page describing the “dawn phenomenon”—a condition many diabetics experience wherein their morning sugar levels are higher than usual . This heOther search results included discussion pages related to the question posed, a stepwise to-do response to the question (such as ways to lose baby weight), external resources, advice on what the poster can do next , and access to social media pages displaying similar situations to the poster’s.Community responses to policy questions provided personal experiences with similar problems and gave posters insight on how to deal with their problems. These responses also prompted posters to think about other questions related to the situation, advised them to visit their health care provider, provided additional resources, reassured posters that they were not alone, and made them aware of potential dangers. For instance, to the question “is anyone on that can tell me how to lower my blood sugar. What can I eat right now to lower it. I had to many carb’s and it’s 202 usually it’s 90 to 101 [sic]”, a response provided stated “Hi, The only way to get your BG lowered from a spike is to exercise and drink a lot of water. There are no foods to bring your glucose level down. At least this is my meager experience and if someone else has a better idea I hope they share with you. Good luck and watch those carbs [sic].”Clinician A observed that 30/49 community responses answered the questions posed, 30/49 responses were clinically relevant, and 31/49 responses were clinically valid. This imbalance between clinical relevance and clinical validity occurred because 1 poster posed a question about having a blood sugar level of 490 and asked how to bring it down so as to get rid of blurry vision. A responder suggested this person should wash his or her hands and try again and, if the sugar reading stayed as high, should call 911 or head to the emergency room immediately. This post was marked clinically valid because all the information it provided was clinically accurate; however, it was not marked as clinically relevant, because the information was not relevant to the actual question asked and did not help answer it .Other community responses to policy questions stressed the dangers of a situation a poster may be in; provided potential solutions to help solve a problem, including suggesting home remedies and advising the poster to visit a health professional; offered personal stories, anecdotes, and opinions; and helped detect emergencies from the situation presented by the poster.Finally, we calculated the interrater reliability of clinicians A and B using Cohen kappa score. The overall kappa for policy questions was .52, indicating weak agreement between the clinicians .Search results for value questions included personal experiences and, therefore, a lot of the search results only partially answered the question or provided an overview of the subject. Search results included products and their reviews, patients’ stories through blog posts, and discussion forums. One result helped with alleviating nervousness, while another showed how others also had similar symptoms. A portion of the questions asked about people’s experiences with medicine or health issues (as elaborated in detail above); therefore, the search results led to online stores and reviews for these products, such as Amazon, where other customers provided reviews for the health information seeker to review. Lastly, some questions were answered, but not necessarily in a diabetes context. For instance, a poster’s question was “I had my first [mammogram] last week and it came back suspicious. Had to go for more [picture] and an ultrasound and now for a biopsy. I am way past scared to death. Can anyone help me [sic]?” the first search result to this question led to a webpage discussion about mammograms in patients. This information provided encouragement to the poster as requested.Among the search results of value questions, clinician A identified that 23/60 results correctly answered the questions. This clinician also found that 23/60 search results were clinically relevant and 29/60 were clinically valid. These results indicate that, while some questions were answered, still others were clinically relevant and clinically valid, but did not answer the question.Other search results for value questions included a comprehensive overview of the subject in question; discussed side effects from credible sources; had comment sections on some webpages discussing the subject; helped differentiate between myths and facts related to the question; led to question-and-answer pages that help answer the question posed; resulted in product reviews for questions about specific products, thereby informing the poster about the quality and effectiveness of the product; included personal experience stories and encouragement, which reduced posters’ nervousness; and included some results that were also backed up with statistical evidence.Community responses, on the other hand, included details about things the question poser should be cautious about, provided side effects of medication, tips, and suggestions, conducted online searches, and found answers for the poster.People are enthusiastic about providing their opinion. The downside of this is that there is no way to verify the answers provided. For instance, a poster posed the question “Have any of you had the Bayer Contour meter just readout “HIGH”? No numeric reading just “HIGH”. I suspect that is a very bad sign [sic].” A response to this was, “Most meters read up to about 500 or 600. Anything higher than that and it simply greets you and says “HI”. Did you test again after washing your hands? If you did call your doc and see someone immediately. This is not good [sic].”For community responses, clinician A noted that 63/104 responses provided answered the questions posed. Additionally, 51/104 were clinically relevant and 47/104 were clinically valid.The types of community responses received by a poster for value questions helped them be wary about new trends; informed them about medicinal side effects and provided insights about how this information was obtained; alerted people to any potential dangers; provided personal experiences, opinions and anecdotes, and tips and solutions to help resolve issues; advised the questioner to visit a health professional; corrected or clarified misinformation; redirected the poster to more resources and information; and reassured and encouraged the poster about his or her current situation.Finally, we calculated the interrater reliability of clinicians A and B using Cohen kappa score. The overall kappa for fact questions was .46, indicating a weak agreement between the 2 clinicians .As can be noted, the Cohen kappa score between both clinicians was not very high, signifying weak interrater reliability. Some of the difference in coding between them can be explained through the following reasons. First, we found many of the search results on webpages containing large amounts of text, thereby making the process of locating the response on the page a difficult one. This sometimes led to 1 clinician coding the search result as answering the question posted, whereas the other did not. This observation depicts how different people, including clinicians, interpret different kinds of search results in terms of whether they answer the question asked. If both coders coded a question differently, the subsequent questions about clinical relevancy and clinical validity also tended to follow different paths. Sometimes, in a situation like this, the search result was coded as answering the question, but the validity or relevance of the answer was queried, therefore leading to different codes between the 2 clinicians. This variability in the results between the 2 clinicians speaks to the complexity of the problem, that is, the difficulty of defining and assessing the quality of information on the Internet.Finally, the 2 coders interpreted the accuracy and relevance of some responses differently, therefore leading to lower kappa scores. This result points to the importance of the way information is shared and interpreted on the Internet and how better guidance and direction for gathering information is necessary. This study contributes to understanding the various factors clinicians consider and how these factors lead to their evaluations.For example, the question “recently lost a kidney/ureter to cancer. sugar levels are moderately changed and i need to know the actual effects i can expect as my body adjusts to life with only one kidney [sic].” leads to a human anatomy textbook online, which clinician A deemed to have an “unknown” value.The community responses, on the other hand, varied in number, since we included every answer to a question posed. The total numbers indicated above are the number of responses each category of community responses received. However, there were questions with no responses at all, such as the question “Help. I just gave myself my pre dinner shot in my leg. It formed a huge bump on my leg. Will the insulin still get in me or do I need to take my shot again???[sic]” had no responses at all and therefore clinician A marked it as “not applicable.”Our analyses showed that community responses answered more questions than did search results across the board. These community responses were more clinically relevant than their search result counterparts. However, clinical validity varied, with search results being more clinically valid than community responses for fact and value questions, but community responses being more clinically valid than search results for policy questions. These observations show that answers from both sources contain clinically accurate information, which does not necessarily answer questions.Search results for fact questions showed that results were often clinically valid but not clinically relevant. Fact question search results had the highest validity among all question types. Even if search results were clinically relevant, only a small portion of those results completely addressed the questions in the query. Questions left unanswered can be attributed to imprecise question phrasing. Wording questions so that their meaning is clear and concise will lead to more relevant search results than will questions with meandering and unclear content. We need mechanisms to help patients formulate queries and questions online.We learned from the search results of policy questions that nearly half of the search results to policy questions contained clinically valid information. However, most of this information was irrelevant to answering the questions and the information was incomplete. A reason for this finding could be the way policy questions are framed. These questions require information about how or what needs to be done in a particular situation. Factoring in the multiple variables in an individual’s question would result in varied search results, none of which answer the question as required.Analysis of value question search results showed that search results often did not answer the question posed, nor was the information clinically relevant. However, a greater number of results were clinically valid, showing that accurate information does not always lead to answers. This observation is in line with fact and policy question search results, where a larger number of results were clinically valid but did not answer the question posed.We observed a similar pattern in the community responses to fact questions, where a greater number of questions were clinically valid and clinically relevant, but fewer questions were answered.For community responses to policy questions, clinician A observed that a much higher number of questions were answered as compared with policy question search results. This shows how the specific nature of policy questions makes them a better fit for an audience who are familiar with the issues of the community, thereby providing posters with the information required.Community responses to value questions were opposite to fact and policy community responses. Value questions were the only question type to which the community provided a greater number of answers, but a smaller fraction of the information provided was accurate. In comparison, fact and policy questions tended to get superfluous but clinically valid responses, leading to more unanswered questions. This finding is important because it portrays the risks of unchecked information being exchanged in online health communities. Value questions ask others for their personal experiences and evaluations, which is a warning to posters about the unmoderated nature of the information.The combined analyses of the coders and the clinicians indicated that policy and value questions get more community responses than do fact questions. This observation could be because these 2 categories ask responders to provide their personal experiences with a situation, and knowing an answer to a question or not (as with fact questions) is not a criterion.Community responses also make question posters feel better about their situation and remind them that they are not alone through reassurances and compliments. The responses warn question posters about potentially dangerous actions or incorrect advice they get from other responders.We also observed that community responses consistently got a higher percentage of questions answered. as opposed to a search results. Therefore, while past research indicates that people go online and search for health-related information, these individuals are more likely to get their questions answered through online social support groups of people in similar situations to their own.Based on the advantages and disadvantages of the search results and community responses (Table1), there are potential recommendations for stakeholders involved.Patients must be vigilant about the information they find through search results by keeping track of the sources of websites and the validity of the information provided. Formation of the question asked in search results also plays a role in the kinds of responses it gets; therefore, posing a clear question while searching for results on the Internet is important. Community responses are provided by similar others, that is, other individuals facing health situations similar to the question poster’s. While this indicates a familiarity with a question posed or a situation described, it is important to verify medically related information or steps to be taken with one’s health care provider so as to prevent negative health consequences.Guiding patients toward accurate information obtained through search results helps providers by not having to correct misconceptions patients build through information they gather via search results. It would be helpful to patients for providers to guide them in searching for information online and in determining whether information is trustworthy.Online health communities play a critical role in providing social support to people going through similar health issues. Self-management of health conditions plays an important role in management of chronic illnesses , such asResearchers should compare different online communities to analyze information sharing for a variety of health conditions. Such health information can help technology developers create more efficient health communities, with more opportunities and resources for patients participating in them. One important finding was the sharing of incorrect or dangerous information by other participants in an online community. Developers could create a way to tag dangerous posts, based on feedback provided by other users, which would require moderators of the community to evaluate such posts and rectify the information provided as needed. Classification of questions based on our codebook may help researchers and developers in the future to tag questions needing professional evaluation. Answers to policy questions provide direction to individuals in need, and value questions give personal evaluation, both of which we have observed to have incorrect information. In future studies, researchers should also focus on the best way to formulate questions to gain the most accurate information through search results. Additionally, it is important to develop a way to help patients analyze whether the information they gather through Internet search results is accurate. Patients look for health information online in large numbers. Therefore, ensuring the accuracy of this information is crucial.Informaticists should analyze the way information is shared in online health communities, especially through the relations between participants within these communities. Participants roles in these communities provide insights into how relationships form and how these relationships lead to an exchange of information. These insights include the kinds of information they share and receive, and whether it is clinical or social in nature. Additionally, informaticists should look into the questions posted, both those searched for on the Internet and those posted in online communities. Such an analysis would prove valuable to determine which questions would be ideally suited to be answer through a search engine versus those ideally posted in an online community .Finally, the trouble faced by both of our clinicians in interpreting similar information differently is a commentary on how difficult it is to find and assess health information online. This observation is important so future websites can address this wide-ranging quality issue.As mentioned above, because the questions posted in the search engine came from a diabetes health community, not all of the questions mention their diabetes context. Community members assume this diabetes context. For example, an evaluation of a particular diet would not ask members to keep in mind that the diet was for a person with diabetes because it was posed in a diabetes community. Because we decided to search unaltered questions in the search engine, the answers we got could have been less efficient (answers not in a diabetes context) than if we had modified the questions to include this parameter. Future studies could make the context explicit to study the differences in answers it would produce.Searching complete questions could misguide a search engine. Future research can focus on alternatives such as carrying out keyword searches with pertinent information from the question as opposed to using the question as an exact-phrase search.Additionally, more than 3 search results can be included in the search result answers. While most people do not venture beyond the first page of search engine results, and even there they focus on simply the first few search results ,29, addiFinally, Google’s page ranking method ranks high-quality websites higher than other websites with a lower level of authority in the related topic . As a result, our findings on the high accuracy of online health information in the first 3 search results are biased toward what Google already ranked as having high authority in the topic. However, most searchers check the first 2 search results, thereby correcting this imbalance .We evaluated the responses people get to health information they seek online from 2 different avenues: search engine results and online community responses. Our findings indicate how question types matter for determining information quality and sources. Health care practitioners, informatics researchers, and policy makers should consider the strengths and weaknesses of each information source based on the types of questions information seekers have. Our study contributes to improving online health information quality, making self-management of health more efficient and lowering costs for medical professionals and patients.


Selected examples of these species are characterized in regard of their properties and possible applications.In the review hybrids of cationic porphyrins ( Porphyrins are planar tetrapyrrolic macrocycles that have interesting properties and value for applications in various fields. They are promising in the design of sensors [e.g. design of solar cells [ sensors  and they sensors ; some me sensors . The rea sensors –10, e.g.ar cells , 12 and ar cells .i.e. porphyrins meso-functionalized by quaternary azaaromatic units, due to the presence of four positive charges are of interest in the construction of next generation photosensitizers [Cationic porphyrins, sitizers . CationiN-methyl-4-pyridinium porphyrin (TMPyP), in this review referred to as A. Among hybrids of cationic porphyrins, those with nanocarbons are a topic of present review.The representative compound of cationic porphyrins is meso-tetrakis, generating singlet oxygen for selective destruction of localized tumors [A growing attention is paid today to interaction of cationic porphyrins with nucleic acids . Cationid tumors .It is noteworthy that antimicrobial photodynamic therapy (aPDT) is now emerging as an alternative to antibiotics; in this procedure the cationic photosensitizers such as cationic porphyrins interact in the excited state with molecular oxygen to produce singlet oxygen that kills the microbial cells .Among a variety of other applications of porphyrins in medicinal field  one may Nanocarbons, belonging to carbon allotropes include zero-dimensional (0D) fullerenes, one-dimensional (1D) carbon nanotubes and two-dimensional (2D) graphene. Nanocarbons have attracted recently a growing attention due to their unique electronic, optical, thermal and chemical properties, promising for their applications in a variety of areas [of areas .i.e. fullerenes consist of bent sp2 carbon atoms. From fullerenes to graphene the strain at sp2 carbon atoms decreases; the surfaces of fullerenes and graphene have different reactivities. In fullerenes attempts to release strain by formation of sp3 carbon centers exist, therefore fullerenes have anomalously large reactivity, while in graphene no strain at carbon atoms is observed, i.e. no tendency for sp3 hybridization occurs, and consequently, graphene is less reactive than fullerenes [The smallest species, llerenes .Nanocarbons are today a topic of an intense research, and a considerable progress in this area is observed. Due to valuable properties they may find applications in various fields; one should point out the importance of these materials so from theoretical and practical viewpoints.Fullerenes, carbon nanotubes and graphene are of interest in the study of artificial photosynthesis and solar energy conversion, in the construction of electronic, optoelectronic, photovoltaic and sensing devices  and in t2 (produced as an emission from use of hydrocarbon fuels) to hydrocarbon fuels [Carbon nanotubes and graphene may be applied in photocatalytic reduction of COon fuels . Carbon on fuels .Carbon nanotubes and graphene are investigated in order to facilitate charge transport across abiotic-biotic interfaces , they ari.e. fullerenes, single wall carbon nanotubes SWCNTs and graphene), acting as electron acceptors, with photosensitizers, acting as electron donors, are promising for this aim. In the experiments concerning the above theme, the light-induced electron transfer processes of nanocarbon hybridized with photosensitizers, have been shown to be very useful for this purpose.Today the use of solar energy is crucial to solve the energy problems for a sustainable society; molecular devices employing hybrids of nanocarbons,  assemblies by electrostatic and charge-transfer interactions; due to these interactions the obtained assemblies are very stable [It was established that octacationic zinc porphyrin ZnPy stable , 60. One60 dendrofullerenes the compounds 1–3 have been used. The formation of the assemblies was investigated by gel electrophoresis. For example, the aggregation of ZnP8+ with 2 yields the assembly porph·2, and with 3 the assemblies porph·3 and porph2·3 are obtained.As C·+/C60·− are formed. All radical ion-pair states decay to their singlet ground states without passing through the intermediate triplet excited states of ZnP8+ or C60 [The results of experiments have shown that radical ion pairs ZnP+ or C60 , 60.The layer-by-layer (LbL) deposition of positively and negatively charged oligoelectrolyte multilayer (OEM) films was investigated in view of their assembly and disassembly behavior. The LbL technique is a simple and very efficient wet-coating method.e.g. on metal or glass. Formation of iterative dipping circles makes it possible to obtain the deposited thin films composed of alternating monolayers of polycations and polyanions. This easy and cheap method affords advanced materials based on polyelectrolyte multilayer films.The LbL process involves the alternate deposition of cationic and anionic species from a solution –65. Due 8+ was used as a positively charged oligoelectrolyte, and compounds 4–6 served as negatively charged oligoelectrolytes. By use of electrolytes 5 and 6 containing the porphyrin chromophore, the deposition could be easily followed by UV–Vis spectroscopy [The octacationic zinc porphyrin ZnPtroscopy . HoweverBesides the assembly, also the first study of disassembly was made; this investigation is promising in incorporation of bioactive molecules at a given inter-layer position, since after removal of the outer layers the bioactive molecules can be released. Such drug delivery is interesting for biomedical use.8+ and 4, 5 or 6 were deposited on planar silica substrates using the alternate dipping method. For investigation of possible application of OEMs as drug delivery systems, the biologically active pamidronate 7 used in the bone metastasis was employed as an anionic building block. The porphyrin ZnP8+ served as a cationic component and at the same time as a reporter electrolyte, therefore the detection of the anionic component occurred indirectly. It was found that the absorbance of ZnP8+ is enhanced when the number of ZnP8+ layers increases; the correlation is linear. This behavior enables the regulation of the amount of deposited 7 by the number of layers.For LbL assembly of molecular oligoelectrolytes, the layers of porphyrin ZnPIt was established that the use of chromophore containing electrolytes, in particular porphyrins allows the observation of both assembly and disassembly of OEMs by optical spectroscopy; the compounds containing chromophore serve here as reporter electrolytes. One should point out that oligoelectrolytes used are monodisperse, and various synthetic procedures enable modification of properties of OEMs. It is of interest that the investigated OEMs may show the time dependent release of active components, this behavior being promising for drug delivery .Carbon nanotubes have interesting mechanical, electronic and optical properties, therefore they are promising for design of composite materials, drug carriers as well as sensing and energy conversion devices. They are investigated with the aim to obtain photo- and redox-responsive materials. Carbon nanotubes, due to their unique structural and electronic properties are of interest for design of hybrids useful in various areas. The applications of nanotubes are today a topic of an enormous amount of reports –72.SWCNTs may be chemically modified for use as nanosized building blocks. This process may be performed by covalent or noncovalent functionalization. The covalent functionalization is rather disadvantageous because of structural changes of nanotubes and loss of some of their unique properties. To overcome this difficulty the noncovalent functionalization of nanotubes is used, this process leads to hybrids of nanotubes with functionalizing agents.The noncovalent functionalization of nanotubes usually proceeds by π-stacking interactions of an organic molecule or polymer with nanotube walls. It is preferable when the attached molecule has an extended π-electron system of bonds, in this respect the use of porphyrins is convenient. It is noteworthy that in porphyrin/nanotube hybrids, the existence of a light-induced charge transfer between porphyrins and SWCNTs is promising for their application in solar energy conversion.In the study of mechanism of the hybrid formation it was found that the interaction of nanotubes and porphyrins with charged side residues is much stronger than in the case of neutral porphyrins. Quantum-chemical calculations have shown that the hybrids formed by nanotubes with charged molecules are stabilized due to strong cation-π interactions. It is noteworthy that such complexes are highly stable in water . HybridsHybrids of cationic porphyrins with carbon nanotubes are a topic of an intense research, below some examples are presented.8 and anionic sodium copper chlorophyllin 9 were used.It is known that assembling composites of chromophores with carbon nanotubes is a crucial process for construction of photoelectronic devices, biosensors and electron storage devices ; for ass8-SWNT/9-SWNT was built from noncovalently adsorbed composites 8-SWNT and 9-SWNT. For this purpose SWNTs were dissolved in water soluble cationic 8 and anionic 9, and the obtained solution served for electrostatic LbL multilayer preparation. The composites were highly dispersed due to existence of π-π interactions [The LbL film ractions .8 and 9 fluorescence resulting from their interaction with SWNT was observed. Due to the efficient charge separation and electron transfer in the above LbL film electrodes, the photocurrent generation is enhanced as compared with 8/9 film electrodes without SWNT.A strong quenching of meso-5,10,15,20-tetraphenylporphyrin 10 with zigzag single-walled carbon nanotube (SWNT) has been investigated by resonance Raman spectroscopy and by ab initio and molecular dynamic calculations [In the study of hybrids of porphyrins with carbon nanotubes the interaction of porphyrins A and ulations .10 with SWNT, since between A and SWNT the cation-π attraction exists. In the molecule A the strong cation-π attraction leads to the saddling; the saddled structure of A provides a closer contact between the charged groups of A with the SWNT surface. The formation of A/SWNT complex in the aqueous solution has been modeled by the molecular dynamics method, showing its stability in the water environment.The results have shown that the interaction of A with SWNT is stronger than the interaction of 4+ or MS4−, respectively, serving as electron donors, and from noncovalently functionalized SWNTs serving as electron acceptors. In a first step, SWNTs were solubilized by π-π stacking of pyrene functionalized by anionic (COO−) or cationic (NH3+) groups. Cationic or anionic porphyrins MA4+ or MS4− were ion-paired with functionalized SWNT/pyr− and SWNT/pyr+ systems to give porphyrin-SWNT donor–acceptor hybrids MA8+/SWNT/pyr− or MS8+/SWNT/pyr+ [Photoinduced electron transfer in ion-paired porphyrin/SWNT hybrids has been studied. The donor–acceptor hybrids have been built from water-soluble cationic or anionic porphyrins MAWNT/pyr+ . The ste2+ or HV2+, respectively) and an electron–hole shifter 1-benzyl-1,4-dihydronicotinamide (BNAH) in water or DMF, used as solvents. The photoinduced processes resulted in the accumulations of radical cations MV·+ and HV·+, due to the electron-pooling in the presence of a sacrificial electron donor. This behavior shows the photoinduced electron transfer and enables photocatalytic applications of the above systems.The charge separation process was further confirmed by an electron mediator (methyl or hexylviologen dication MVThe immobilization of porphyrin A on the carbon nanohorn (CNH) was investigated in order to design donor–acceptor CNH-based hybrids for managing electronic interactions in environmentally friendly aqueous media. In the experiments the water soluble porphyrin A has been immobilized by π-π stacking interactions on carbon nanohorns (CNHs); this process does not disrupt their π-electronic network .i.e. oxidation of the porphyrin and reduction of the nanohorns were studied by transient absorption spectroscopy. In the presence of MV2+ and a hole trap, the accumulation of the reduced form of methyl viologen was observed by the illumination of A-CNH; this behavior shows the electron migration from the initially formed charge-separated state [The efficient fluorescence quenching of the A unit in the A/CNH assembly suggests charge separations from the photoexcited A to CNH. The photoinduced charge-separation processes within the illuminated A/CNH hybrids, ed state .2 laser ablation of graphite in the absence of metal catalyst under the inert argon atmosphere. The mild sonication of CNH in aqueous solution of A afforded the water soluble A/CNH hybrid. It was found that the morphology of CNH was retained upon immobilization of A, this suggests that the stacking of A onto CNH does not alter the aggregation of CNHs. The high solubilization of CNHs in aqueous solution shows that the surface of CNHs is covered by A.The CNHs were produced by COIt is noteworthy that CNHs are more convenient for design of nanomaterials than carbon nanotubes, since they are of a high purity due to the absence of any metal nanoparticles during the laser ablation production, and they have heterogenous surface structure resulting from highly strained conical ends. It is important that the rough surface structure of CNH aggregates enables the better dispersion of CNHs in liquid media than in the case of tightly bundled carbon nanotubes.In investigation of systems able to mimic natural photosynthesis, the hybrids built from porphyrins and CNHs are of interest. They contain CNHs behaving as electron acceptors and porphyrins as electron donors which act as light-harvesting antennas capturing visible light and transducing the excitation energy. It should be pointed out that the above A/CNH assemblies are promising for use in solar energy conversion.8+, namely FeP8+ and CoP8+ with SWNTs was investigated. For this purpose SWNTs were functionalized with anionic pyrenes from among 11a–d and treated with metalloporphyrins FeP8+ or CoP8+. It was observed that the resulting MP8+/SWNT/pyr− assemblies form stable hybrid structures in aqueous media (pyr− = pyrene). An important feature of this procedure is that an efficient exfoliation of the initial bundles affords isolated nanohybrid structures [Formation of hybrids of cationic, water soluble metalloporphyrins MPructures .8+/SWNT/pyr− hybrid with visible light, the rapid intrahybrid electron transfer from the photoexcited MP8+ to SWNT occurs. This fact causes the reduction of the electron-accepting SWNT and, at the same time, the oxidation of the electron donating MP8+.Upon excitation of the above MPOne should note the importance of SWNT templates bearing carboxylate or sulfonate groups. These negative groups act as promoters for suspending SWNT samples in aqueous media and as anchors interacting with pyridinium headgroups present in metalloporphyrins. Pyrene compounds are strong fluorophores therefore they are useful sensitive markers in the performed experiments, the fluorescence spectroscopy being a very convenient tool for investigation of the above electron donor–acceptor interactions.e.g. high charge carrier mobility, graphene is today a topic of an intense research [Graphene is a single layer of graphite, where carbon atoms are arranged in a honeycomb lattice; owing to its specific electronic and mechanical properties, research –92. One research . In contresearch .The selected techniques for preparation of graphene and related species are presented below . The comGraphene oxide (GO) is the single-layered graphite oxide which can be prepared by the exfoliation of graphite oxide. GO having many functional groups such as hydroxyl, aldehyde, carboxyl, epoxy is obtained by exposing graphite powder to strong oxidant solutions, e.g. KMnO4/H2SO4 followed by H2O2 (30 %). Exfoliation is performed by sonication of GO dispersion.Chemically converted graphene (CCG) is prepared by reduction of GO suspensions e.g. with hydrazine; in this way a majority of the oxygen functional groups undergoes elimination and the conjugated structure of GO is restored.Carboxylic acid modified GO (CGO) is obtained by sonication of GO under basic conditions, followed by neutralization with HCl; it selectively reserves the carboxylic acid functional groups.The unique electronic system of graphene results from its high quality 2D crystal lattice in which electrons can move without being scattered off, therefore high electrical conductivity exists. As drawbacks of graphene may be considered its severe stacking as well as its complete insolubility in all solvents including water. Therefore in the investigation of graphene the main topics are its exfoliation from graphite and its solubilization. Chemical methods of exfoliation involve the use of strong acids , ionic lIn order to improve the chemical compatibility of graphene with diverse media, it is necessary to develop its well-dispersed form. For this purpose covalent and noncovalent functionalization of graphene with various molecules and nanomaterials was investigated in water and in organic solvents –103.covalent functionalization of graphene introduces sp3 defects in its lattice; this behavior decreases its high conductivity [noncovalent functionalization may be used, in this way the electronic network of graphene is not disrupted [Functionalization of graphene offers its new application possibilities. However, the extensive uctivity . To overisrupted . NoncovaIn the noncovalent functionalization the planar aromatic organic molecules are employed; they interact through numerous π–π van des Waals forces with the graphitic framework and promote spontaneous exfoliation . For a ngraphene-coated metal NPs and graphenes modified by metal NPs; four examples concerning this theme will be given (NP = nanoparticle).Describing graphene it seems noteworthy to mention graphene-coated metal NPs two examples will be shown. In the first one the graphene-coated CoNPs 12 which can be functionalized are presented; e.g. they can react with 4-nitrobenzene diazonium tetrafluoroborate to give p-nitrophenyl derivative 13, which upon reduction with elemental sulfur affords aminoderivative 14 useful for peptide coupling [In the study of coupling , 110–11215 undergo “click” reaction with stable radical propargyl ether TEMPO 16 yielding 17 which is an efficient catalyst for oxidation of primary and secondary alcohols [In the next example the graphene-coated CoNPs functionalized by (azidomethyl)benzene alcohols .graphenes modified by NPs, two examples, i.e. graphenes modified by AuNPs and by AgNPs will be shown. Graphene sheets composed from 2 to 10 layers may serve for preparation of graphenes modified by NPs. Chemical exfoliation of graphite in aqueous medium  afforded GO; the subsequent thermal treatment of GO  promoted further exfoliation.In the study of 4 solution, and the subsequent reaction with sodium citrate afforded graphene modified by AuNPs. This material may serve as a substrate for surface-enhanced Raman scattering (SERS) [The oxygen functionalities (hydroxyl and epoxy groups) situated on the graphene surface are reactive sites for chemical modification and for deposition of NPs . The preg (SERS) .2 films. It was observed that upon UV illumination of TiO2/GO films, the photogenerated electrons from TiO2 are captured by GO. [2 network. The stored electrons can serve for reduction of metal ions to metal NPs.Another method was used for preparation of graphene modified by AgNPs. GO sheets have been anchored onto TiOd by GO. , 116. Th2, since GO is able to transport electrons through its plane. The above procedure is possible due to the unique property of GO/RGO to shuttle electrons in a direction orthogonal to its plane, and transfer electrons to Ag+ ions. The formed semiconductor-graphene-metal (SGM) film is valuable for catalysis and sensor use. These SGM films, tested as SERS sensors produced considerable target molecule signal enhancement, in this way enabling detection of their nanomolar concentrations.In the presence of silver ions, the AgNPs begin deposit onto GO surface opposite TiOIt seems that the above examples concerning graphene-coated NPs and graphenes modified by NPs may be considered as a supplement to the wide field of graphene applications –122.i.e. hybrids of cationic porphyrins with graphene [Hybrids of cationic porphyrins with graphene are today intensively studied. Among many works concerning graphenes functionalized by porphyrins –126, a sgraphene –131.i.e. GO, CCG and CGO with porphyrin A was studied. It was observed that the intermolecular interaction occurs immediately upon mixing graphene with A; in this process A is immobilized on the graphene surface via electrostatic and π-π stacking interactions.The noncovalent functionalization of graphene with porphyrins was widely investigated , 131. InIt is worth noting that functional groups on the surface and edge of GO, CCG and CGO play an important role in functionalization of graphenes with A. The strong fluorescence quenching of A upon its interaction with graphene is due to the efficient electron or energy transfer from excited state A to graphene. The red shift of Soret band of A occurring at its interaction with graphene depends on the kind of functional groups of graphene and decreases in the order CCG > CGO > GO .4+. As a result, the aqueous dispersion of graphene/pol/A4+ assembly was formed. It was established by photoluminescence experiments that in this assembly the graphene layers act as electron acceptor, and A is the photoexcited electron donor.In further experiments porphyrin A was integrated via Coulombic interactions to exfoliated graphene, and the possible photoinduced electron/energy transfer phenomena have been investigated . It is kThe absorption and fluorescence spectroscopic measurements have shown the presence of electronic communication between A and graphene in the ground and excited states. Basing on experimental results and taking into account the reported redox potential of graphene , one mayIt is known that the selectivity and improved sensitivity of SERS measurements are desirable for analytical and environmental applications. The RGO-AgNP composite has been studied for improvement of surface-enhanced resonance Raman signal (SERRS) sensitivity of porphyrin A . The SERS-active materials include noble metal NPs, such as silver or gold NPs. These NPs provide a localized surface plasmon resonance leading to a large local electromagnetic field which can enhance Raman scattering signals, enabling single molecule SERS . Metal NThe RGO-AgNP composite is promising for use as a SERS substrate. Graphene has high surface area, therefore is suitable for dispersion of metal NPs. It was observed that metal NPs can be grown directly on graphene by a simple solution-based approach. The intrinsic ability of RGO to adsorb and complex with molecular species facilitates the enhanced SERRS sensing.i.e. porphyrin A interaction; in experiments RGO was shown to be an effective substrate for dispersing AgNPs. The red shift of the Soret band of A in UV–Vis absorption spectrophotometry, observed upon complexation of A with RGO-AgNP confirms this behavior [The increased sensitivity for SERS detection using RGO-AgNP composite was investigated in terms of RGO-AgNP-target molecule, behavior . It was i.e. fullerenes, carbon nanotubes and graphene showed to be promising for various applications, therefore recently they are a topic of a wide investigation. In view of the intense progress in the field of porphyrins [e.g. in the area of electronics or photovoltaics.Hybrids of cationic porphyrins with nanocarbons, rphyrins –138, fulrphyrins –142, carrphyrins –146 and rphyrins –150 one In a summary it should be pointed out that the theme concerning hybrids of cationic porphyrins with nanocarbons is very large, therefore from among a great number of reports only selected works have been shown in the review. However, one may hope that, although not exhaustive, it would to some extent help to gain better insight into this area, promising for novel, valuable applications.