The demonstrated novel and simple scheme for obtaining graphene p-n junctions can be used for other optoelectronic devices such as solar cells and be applied to other two dimensional materials based devices.Graphene has been considered as an attractive material for optoelectronic applications such as photodetectors owing to its extraordinary properties, e.g. broadband absorption and ultrahigh mobility. However, challenges still remain in fundamental and practical aspects of the conventional graphene photodetectors which normally rely on the photoconductive mode of operation which has the drawback of e.g. high dark current. Here, we demonstrated the photovoltaic mode operation in graphene p-n junctions fabricated by a simple but effective electron irradiation method that induces n-type doping in intrinsic p-type graphene. The physical mechanism of the junction formation is owing to the substrate gating effect caused by electron irradiation. Photoresponse was obtained for this type of photodetector because the photoexcited electron-hole pairs can be separated in the graphene p-n junction by the built-in potential. The fabricated graphene p-n junction photodetectors exhibit a high detectivity up to ~3 × 10 Graphene, a single layer of carbon atoms arranged in a honeycomb lattice with broadband light absorption spectrum57et al.1213151720Pioneering works have already been reported on building asymmetric potential in graphene sheet, attempting to obtain graphene p-n junctions where the photoexcited electron-hole pairs can be intrinsically separated. For instance, Mueller 2 interface in the substrate which induces a gating effect on the irradiated graphene. Using this novel but simple strategy, we obtained graphene photodetectors in a field effect transistor (FET) structure with high detectivity and fast response time which were found to be strongly dependent on the electron irradiation. The methodology demonstrated here enables us to modify the transport properties of graphene by electron irradiation, thus paving the way to fabricating graphene homo-junctions controllably and benefiting the future electronic and photonic applications of graphene and other two dimensional (2D) materials based electronic and optoelectronic devices.In this study, we partially irradiated the graphene sheet to obtain an n-type graphene region which is originally p-doped, thus forming a lateral graphene p-n junction. The physical mechanism behind it is due to the interaction of the electron beam with the Si/SiO2/Si wafer and then verified by Raman spectroscopy (see Methods). We next fabricated single layer graphene FETs with the heavily doped silicon substrate as a backgate electrode by standard photolithography and e-beam evaporation. After that, the FETs were placed in a scanning electron microscope (SEM) under high vacuum and selected area was exposed to the electron beam with controlled low-energy electron beam irradiation (see Methods). The electron beam irradiates part of the graphene sheet and modifies the properties of graphene and the SiO2/Si substrateSingle layer graphene samples were fabricated by mechanical exfoliation of highly ordered pyrolytic graphite (HOPG) on SiOds/dVb × L/(W × (ε0εr/d) × Vds), where L, W and d are the channel length, width and the thickness of SiO2 layer (285 nm in our devices), Vds, Ids and Vb are source-drain bias, current and bottom gate voltage, ε0 and εr are the vacuum dielectric constant and the dielectric constant of SiO2 (εr = 3.9), respectively. The mobility of the n-type region (~1500 cm2 V−1s−1) is several times lower than that of pristine graphene (~5500 cm2 V−1s−1), which might be caused by the change of carrier density and the shift of Fermi level in the graphene channel after the electron irradiation2223Electrical transport measurements were employed to investigate the effect of electron beam irradiation on the electronic properties of graphene FETs. As shown in Fermi level of graphene can be characterized and qualified by the G peak position of graphene. As shown in The doping effect of electron irradiation on graphene as demonstrated by the G peak shift as shown in D2> is the deformation potential of the E2g mode, M is the atomic weight of carbon, ω0 is the frequency of the G-band in perfect graphene, υF is the Fermi velocity of graphene, and ΔEF is the shift of the Fermi level. The blue shift of G peak indicates n-type doping resulting from the charge transfer from the treatment or the substrate to grapheneG peak. Similarly we can plot the Fermi level shifts of the samples with different irradiated times from 10 s to 50 s in where <D, D’ and D + G bands at ~1350 cm−1, 1630 cm−1 and 2930 cm−1, and their intensities increase with irradiation dosage that controlled by the irradiation time. On the other hand, these three bands are absent in the pristine graphene sample as shown in 2D band at ~2700 cm−1 remains symmetric, although the intensity decreases slowly with the irradiation dosage, which indicates the decrease of the quality of graphene under the electron irradiation. The decrease of I2D/IG with the irradiation time longer than 50s indicates the amorphization of graphene from sp2 to sp3 carbonThere are two mechanisms that may contribute to the shift of the Fermi level of graphene from negative (p-doped) to positive (n-doped): defect effectD) induced by electron irradiation can be calculated fromL (2.33 eV) is the laser excitation energy, I(D) and I(G) are the intensities of the D band and G band as shown in 13 cm−2). This low defect effect here cannot cause the opening of bandgap of graphene, which is consistent with the density function theory (DFT) calculations in previous worksHowever, we note that a relatively large Fermi level shift of ~0.3 eV for the sample after 50 second electron irradiation cannot be totally contributed to the generation of defects in which the excess electrons are localized according to density function theory (DFT) predication and experimental demonstration292/Si interface because of the mismatch of the workfunction of silicon and p-doped silica where the conduction and valence bands in Silicon bend downward at the interface2 interface2/Si interfaceThe main physical mechanism changing the p-doped graphene to n-doped under electron beam irradiation is shown in IPC = CPγ (C is a constant and P is the illumination power) as shown in 34533The potential barrier built here is the force driving the separation and transportation of photo-excited electron-hole pairs and facilitates the optoelectronic applications of graphene. 10 Jones (cm Hz1/2 W−1) for both 633 nm and 532 nm laser illuminations (see methods), which is in the same level as these for conventional semiconductor phototransistors.Another key figure of merit for a photodetector is the detectivity, which is defined as the ability to distinguish photoresponse signal from noise. In our devices, all the photoresponse measurements are conducted without source-drain bias as the photoexcited carriers can be separated by the built-in potential in the p-n junction, resulting in an extremely low dark current and invoking a high detectivity in the range of 3 × 10To summarize, we investigated the electron irradiation effect on graphene FETs and its optoelectronic application as a photodetector. The energetic electron collision induces defects on graphene sheet and modifies the substrate band bending, resulting in localized n-type doping of graphene. A potential barrier is built between the un-irradiated and irradiated regimes efficiently separating the photo-excited electron-hole pairs. On the other hand, the energetic electron/graphene collision reduces the carrier mobility and photoresponse speed of graphene based photodetectors. This work highlights the importance of the irradiation created potential barrier for graphene photodetectors and opens new venues for exploring graphene based optoelectronic devices.2 layer. The silicon substrate was heavily doped p-type silicon which was employed as a back gate electrode. The location and quality of graphene was identified by optical contrast using an optical microscope and Raman spectroscopymW to avoid the laser induced damage of the graphene sample.Single layer graphene flakes were mechanically exfoliated from a crystal of highly oriented pyrolytic graphite (HOPG) using adhesive 3M-tape and deposited on a silicon wafer with a 285 nm thermalized SiO−6 Torr) under a voltage of 20 kV. The emission current was kept at 10 μA, which corresponded to a ~10 pA beam current under our experimental condition. The SEM images were taken under a low voltage (~1 kV) to reduce the irradiation effect. Soon after the location of the sample, the irradiation process was carried out with a selected area of 20 × 20 μm2 focused by the electron gun and covered part of the FET channel. The electron irradiation dosage (DOS) was controlled by the exposing time as the electron flux was kept constant during all experiments. The dose density for our device was ~n × 40 e/nm2 after n times of scans (every scan lasts 10 s). AFM  was used to image the un-exposed and exposed graphene samples in taping mode in air by measuring the surface morphology and height profiles. The electrical characteristics were examined by a semiconductor analyzer . The photoresponsivity measurement was performed in a digital deep level transient spectroscopy (BIORAD) system with different lasers to illuminate the whole devices. The gain and detectivity are calculated as followingElectron beam irradiation was conducted with a JEOL field-emission SEM system under high vacuum .


The prelimbic (PL) cortex allows rodents to adapt their responding under changing experimental circumstances. In line with this, the PL cortex has been implicated in strategy set shifting, attentional set shifting, the resolution of response conflict, and the modulation of attention towards predictive stimuli. One interpretation of this research is that the PL cortex is involved in using information garnered from higher-order cues in the environment to modulate how an animal responds to environmental stimuli. However, data supporting this view of PL function in the aversive domain are lacking. In the following experiments, we attempted to answer two questions. Firstly, we wanted to investigate whether the role of the PL cortex in using higher-order cues to influence responding generalizes across appetitive and aversive domains. Secondly, as much of the research has focused on a role for the PL cortex in performance, we wanted to assess whether this region is also involved in the acquisition of hierarchal associations which facilitate an ability to use higher-order cues to modulate responding. In order to answer these questions, we assessed the impact of PL inactivation during both the acquisition and expression of a contextual bi-conditional discrimination. A contextual bi-conditional discrimination involves presenting two stimuli. In one context, one stimulus is paired with shock while the other is presented without shock. In another context, these contingencies are reversed. Thus, animals have to use the present contextual cues to disambiguate the significance of the stimulus and respond appropriately. We found that PL inactivation disrupted both the encoding and expression of these context-dependent associations. This supports a role for the PL cortex in allowing higher-order cues to modulate both learning about, and responding towards, different cues. We discuss these findings in the broader context of functioning in the medial prefrontal cortex (PFC). Previous research has demonstrated that the prelimbic (PL) cortex facilitates the ability of animals to respond adaptively under changing circumstances. For example, function in the PL cortex is necessary to allow animals to exhibit an instrumental response which is reflective of the current value of a goal, a switch between response and strategy sets, the use of contextual cues to resolve response conflict, and a change in the degree of attention directed towards a stimulus on the basis of how well it predicts a motivationally-significant outcome . In one context (context A), one CS (CS1) would be paired with shock, and the other CS (CS2) would be presented in the absence of shock. In the other context (context B), these contingencies are reversed so that CS1 would now be presented in the absence of shock, and CS2 would be paired with shock in this context. In a subsequent test session, rats will be presented with both CSs in both contexts under extinction to assess whether their behavior towards the CSs is reflective of the contexts in which they were trained. The nature of this procedure, where the CSs are predictive of shock in one context and not in another, likely necessitates that the animals use the context  to inform the animal of the status of the CS in that context. This would allow the context to exert top-down modulation over responding to the CS. Thus, investigating the role of the PL cortex in this task will bring insight into whether this region is involved in using contextual cues to modulate responding towards a CS in an aversive procedure.We investigated the role of the PL cortex in the contextual bi-conditional discrimination at two time points. More specifically, Experiment 1 investigated the impact of PL inactivation during the extinction test session, where animals had to express the associations formed during acquisition of the contextual bi-conditional discrimination. On the basis of the research in the appetitive domain, we anticipated that animals without PL function would be unable to use the contextual cues present at test to modulate responding towards the CSs. In Experiment 2, we investigated the impact of PL inactivation during acquisition of the discrimination. If the PL cortex is involved in the development of a conditional association where the context comes to modulate the expression of a response, inactivation during acquisition will disrupt the subsequent expression of the contextually-dependent response at test.Subjects were experimentally-naïve male albino Wistar rats , weighing between 350 and 450 g at the start of the experiment. All animals were housed 4 rats per cage in a temperature- and humidity-controlled (22°C) environment in a 12 h light/dark cycle (lights on at 7:00 am). Rats were between 10–14 weeks at the commencement of the experiment. All behavioral and surgical procedures took place during the light cycle. Rats were handled 3 days prior to surgical procedures.All animal procedures, both experimental and routine care, were carried out in accordance with the National Institute of Health Guide for the Care and Use of Laboratory Animals  and were approved by the University of New South Wales Animals Care and Ethics Committee (ACE: 13/102A).Prior to any training, surgery was conducted under complete anesthesia induced by inhalation of isoflurane in oxygen carrier . Following the onset of anesthesia, rats were placed in a stereotaxic frame . An incision was made into the scalp, and the skin was retracted to expose the skull. For each rat, the incisor bar was adjusted such that bregma and lambda were level. Small holes above the intended lesion site were made with a high-speed dental drill, and the dura mater was severed to reveal the cortical parenchyma. Bilateral stainless steel guide cannulae  were lowered 0.5 mm dorsal to the infusion site . Cannulae were held in place by dental cement and anchored to the skull with four fixing screws located on different bone plates. Removable dummy cannulae were inserted into the guide cannulae to prevent the cannulae from blocking.A agonist; 5-aminomethyl-3-hydroxyisoxazole; Sigma- Aldrich, Australia) was dissolved in nonpyrogenic saline (0.9% w/v) to obtain a final concentration of 0.5μg/μl and was infused bilaterally into the PL cortex by inserting a 33 gauge internal cannula into the guide cannula. The internal cannula was connected to a 25 μl glass syringe  attached to an infusion pump (World Precision Instruments Inc.) and projected an additional 0.5 mm from the tip of the guide cannula. A total volume of 0.5 μl was infused bilaterally at a rate of 0.5 μl/min. This amount was in line with those used in appetitive experiments demonstrating effects selective to the PL cortex  and one in the afternoon (PM) separated by at least 3 h.Training and testing took place in 8 operant chambers  which were individually housed in light- and sound-attenuating compartments. Boxes were 30 cm wide × 24 cm deep × 21 cm high and consisted of two aluminium walls and an aluminium ceiling, and two Perspex side walls. The chamber floors were constructed of 19 stainless steel rods . Each chamber was equipped with a pellet dispenser that delivered one 45-mg pellet into a recessed magazine when activated. Two levers could be extended to the left and right of the recessed magazine. Two panel lights (2 cm in diameter), were located on the right hand wall of the chamber above the magazine. A 3 W house light was located on the upper left hand wall of the chambers. The chambers contained a white noise and a heavy duty relay that delivered a 5 kHz clicker stimulus. A computer equipped with MED-PC software (Med Associates) controlled the equipment and recorded the responses.Different wallpapers, scents, and lighting were used to create two contexts that were used for the duration of the experiments. Four of the chambers were designated as contexts A (CXT A) and fitted out with laminated spotted wallpapers on three of the four walls. During sessions in these boxes, the house light and both panel lights were illuminated and diluted peppermint essence (10% solution) was dropped in four corners of the bedding below the steel rod flooring to create a strong scent within these compartments. The remaining four boxes served as context B and were fitted out with sandpaper on three of the four walls, and only the house light was illuminated during sessions in this context. Further, diluted rose essence (10% solution) was used as the defining scent for this context. Half the rats in each experiment received AM training sessions in context A and PM training sessions in context B, while the other half received AM training in context B and PM training sessions in context A.The CSs used were 30-s presentations of a clicker stimulus and a white noise. The unconditioned stimulus (US) used for fear conditioning was a 1-s 0.8 mA shock delivered through the stainless steel rods on the floor of the operant chambers connected to a scrambled shock generator . The design for Experiments 1 and 2 is represented in Table In Experiment 1 and 2, rats each received lever training in both CXT A and CXT B prior to conditioning. During conditioning sessions in CXT A, rats received pairings of CS1 with shock, while CS2 was presented without shock. In CXT B rats received pairings of CS2 with shock, while CS1 was paired without shock. Rats were then tested for levels of responding to both CSs in both CXT A and CXT B. CS1 and CS2 were either a clicker or a white noise stimulus, counterbalanced across rats. + denotes delivery of a 0.8 mA shock. Bold characters indicate infusion of either muscimol or saline.All rats received 2 30-min sessions of magazine training, one in each context, where a 45 mg grain pellet  was delivered according to a 60-s variable time schedule. Following magazine training, rats received 6 lever-training sessions, three in each context. In context A, the right lever was made available whereas in context B the left lever was made available. In the first two lever-training sessions, each lever press was reinforced with delivery of a pellet  and ended once rats had received forty rewards. Rats then progressed onto a 30-s variable interval schedule where a reward became available on average once every 30 s and the next lever-press response led to the delivery of this reward. In the final two lever-training sessions, this schedule was reduced further and the reward became available on average once every 60 s. Following instrumental training, rats progressed to conditioning phase of the experiment. During all training and testing sessions, the lever was extended and reinforcement available according to a 60-s variable interval schedule as per the last sessions of training.Rats each received 7 conditioning sessions. Two CSs were used, a clicker and a white noise. If the stimulus was followed by the shock US, the shock was presented at the offset of the stimulus. For half the rats in each experiment, context A signaled that the clicker would lead to shock and the noise did not, whereas context B signaled that the noise would be followed by shock and the clicker would not. This contingency was reversed for the other half of the rats in each experiment. Each conditioning session comprised 6 CS presentations, 3 of each stimulus, with an ITI varying around a 7-min mean. This yielded sessions of approximately around 55 min long. In Experiment 1, rats received mock infusions 10 min prior to the conditioning session, where dummy cannulae were removed and the infusion needle was lowered into the PL cortex without the administration of any substance. In Experiment 2, rats received infusions of muscimol or saline into the PL cortex 10 min prior to the start of the session.Twenty four hours following the final conditioning session, rats received two extinction test sessions, one in each context. The extinction test sessions were the same as the conditioning sessions with the exception that no CS was followed by delivery of shock. In Experiment 1, rats received infusions of muscimol or saline into the PL cortex 10 min prior to the start of the extinction test session. In Experiment 2, rats received mock infusions 10 min prior to the extinction test session, where dummy cannulae were removed and the infusion needle was lowered into the PL cortex without the administration of any substance.Suppression of lever pressing was used to assess fear to the CS , where A is the period during CS presentation and B is the 30 s pre-CS period). Thus, a suppression ratio below 0.5 indicates a suppression of lever pressing during CS presentation, where lower number indicates greater suppression .All the end of all experiments, rats were killed with an overdose of sodium pentobarbitone  and decapitated. Brains were removed, immediately placed on a Peltier element of a cryostat  and frozen overnight. 40 μm coronal sections were cut through the region of the PL cortex and mounted onto glass slides. Tissue was stained using 1% cresyl violet nissl stain and subsequently assessed for the placement of cannulae microscopically by a trained observer. The PL region was defined by the boundaries specified in the atlas of Paxinos and Watson . Rats win = 9, muscimol-infused animals n = 12.Figure F < 1). It is worth noting here that this is a relatively low rate of responding. It is possible that the presence of the cannulae on the heads of the animals make magazine entries slightly more arduous and therefore lever pressing is reduced as it take longer for animals to retrieve reward or check whether reward has been delivered in the magazine. This would be particularly the case early on in instrumental training when magazine entries are the dominant response. In line with this, our pilot studies have indicated that animals perform at a slightly higher rate without the presence of cannulae.All rats acquired the lever-press response within the first two CRF sessions, each receiving 40 pellets in each context. Further, all animals maintained a stable rate of responding across instrumental sessions with the leaner reinforcement schedule with a one-way ANOVA of the average number of lever presses made per minute during these sessions revealing no differences in baseline rates between the intended groups (mean (±SEM): saline 3.57 (0.49); muscimol 3.50 (0.23), F = 4.03, p > 0.05) and no interaction between the intended groups (F < 1). Further, this analysis also demonstrated that there was no overall differences between levels of suppression between the intended groups (F < 1). A one-way ANOVA also revealed that there was no difference between the intended groups in the number of lever-press responses made during the 30-s pre-CS period (mean (SEM): to-be saline 2.19 (0.37); to-be muscimol 2.72 (0.52); F < 1).Figure F = 4.01, p = 0.06), however, there was a significant interaction between CS and group  = 7.17, p < 0.05). This analysis also revealed that there was no overall difference in levels of suppression between groups (F < 1). Follow-up analyses of simple main effects demonstrated that the source of this interaction was due to rats in the saline-infused group exhibiting a significant difference in levels of fear exhibited towards the CS trained in the test context relative to the CS that did not predict shock in that context  = 9.58, p < 0.05). Rats infused with muscimol during the test session failed to demonstrate this difference (F < 1). There was no difference between groups in levels of responding to the non-reinforced cues  = 1.91, p > 0.05), or the reinforced cues (F < 1). There was also no difference in average levels of pre-CS responding across these sessions (mean (±SEM): saline 3.78 (0.33); muscimol 3.63 (0.48), F < 1).Figure n = 6, muscimol-infused animals n = 7.Figure F < 1).All rats acquired both left and right lever-press responses within the first two CRF sessions, each receiving 40 pellets in each context. All animals maintained a stable rate of responding across instrumental sessions with the lean reinforcement schedule with a one-way ANOVA of the average number of lever presses made per minute during the final session demonstrating that there was no differences in lever-pressing rates between the intended groups (mean (±SEM): saline 4.52 (0.68); muscimol 4.94 (0.71), Fs < 1). Further, there was no difference in average number of lever presses made during the 30-s pre-CS period across conditioning sessions (mean (±SEM): saline 2.50 (0.56); muscimol 3.07(0.29); F = 1.41, p > 0.05).Figure F = 5.68, p < 0.05). This analysis also demonstrated that there was no significant between-group differences in overall levels of suppression (F < 1). Follow-up analysis of simple main effects demonstrated that the source of the interaction was due to a significant difference in responding to the non-reinforced and reinforced cues in the saline-infused animals  = 7.02, p < 0.05), but no such difference in the muscimol-infused animals (F < 1). There was no significant simple main effect for responding to cues non-reinforced in the test context  = 2.68, p > 0.05), or in responding to the cues non-reinforced in the test context (F < 1). Further, there were no differences in levels of lever pressing during the pre-CS period (mean (±SEM): saline 4.07 (1.52); muscimol 3.33 (0.29), F < 1).Figure The present experiments aimed to address two questions. Firstly, we wanted to investigate whether a role for the PL cortex in using contextual cues to modulate responding could be generalized to the aversive domain. Secondly, we wanted to examine whether the PL cortex may also be involved in the acquisition of an hierarchal association which subsequently allows an animal to use contextual cues to modulate responding. In Experiment 1 we found that animals without PL function during the extinction test session failed to use the present contextual cues to modulate responding to the CSs. Further, Experiment 2 demonstrated that the PL cortex is also involved in the acquisition of the contextual bi-conditional discrimination. That is, we found that animals without PL function during the conditioning phase failed to express context-specific responding towards the CSs when tested drug free. Taken together, these data demonstrate that the PL cortex is necessary to allow animals to modulate their response towards a stimulus. In addition, these studies show for the first time that the PL cortex also contributes to the ability of animals to form context-specific associations that allows them to use conditional cues to modulate responding towards CSs in the future.There are many forms that the contextually-mediated associations developed in the contextual bi-conditional association may take. For example, Bouton’s , 1994 inIn contrast to a role of context in exerting control over Pavlovian associations, other researchers have argued that the association that is formed when the CS is not reinforced involves a stimulus-response (S-R) association , rather, the IL cortex is argued to be involved in the promotion of S-R pathways independently of contextual cues, whether the associations between the stimulus and response is inhibitory or excitatory. For example, in the case of extinction these S-R pathways may involve inhibitory associations (Delamater, In line with the framework discussed above, these data can be interpreted as a role for the IL cortex in opposing the process whereby the PL cortex exert top-down control to bias activation of the S-R pathway appropriate to current circumstance. Rather, the IL cortex appears to promote the performance of the response at the terminal end of the stronger S-R pathway. This results in behavior becoming impervious to the influence of contextual cues following extended training, where the strong S-R pathway becomes capable of dominating behavior. It is unclear whether the IL cortex directly opposes the influence of the PL locally, or whether the IL cortex promotes the activation of the stronger S-R pathway at a broader, circuit level. Given the lack of projections of the IL cortex to other regions involved in promoting habitual performance (i.e., the dorsolateral striatum, DLS; but see a role for the central nucleus of the amygdala, Lingawi and Balleine, The present experiments have demonstrated that the PL cortex is involved in facilitating the use of contextual cues to modulate responding towards a CS in the aversive domain. Further, we have found for the first time that this region is involved in the formation of the context-specific associations. In doing so, we have found evidence to support for a framework whereby the PL cortex exerts top-down control over S-R pathways according to present contextual cues, to influence both the acquisition and expression of conditioned fear. This is consistent with the functional role of the PL cortex in appetitive procedures. In contrast, previous research has suggested that the IL cortex opposes the role of the PL cortex in facilitating context-specific responding to promote execution of the well-trained, context-independent response across both aversive and appetitive procedure. Taken together, these data suggest that the PL and IL cortices act in a manner to establish a trade-off between using contextual cues to change responding when appropriate and performing a well-trained response independently of contextual cues.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Transposable elements (TEs) are notable drivers of genetic innovation. Over evolutionary time, TE insertions can supply new promoter, enhancer, and insulator elements to protein-coding genes and establish novel, species-specific gene regulatory networks. Conversely, ongoing TE-driven insertional mutagenesis, nonhomologous recombination, and other potentially deleterious processes can cause sporadic disease by disrupting genome integrity or inducing abrupt gene expression changes. Here, we discuss recent evidence suggesting that TEs may contribute regulatory innovation to mammalian embryonic and pluripotent states as a means to ward off complete repression by their host genome. Mammalian embryonic development is governed by a complex set of genetic and epigenetic instructions. This genomic blueprint undergoes evolutionary selection and, as such, the fundamental order of development is well conserved among mammals. At fertilization, sperm and egg unite to form the zygote, which undergoes successive cleavage divisions, yielding two-, four-, and eight-cell embryonic stages , 2. InitPluripotent states arising embryonically in vivo, or achieved in vitro by cellular reprogramming, are associated with epigenetic derepression and transcriptional activation of transposable elements (TEs) –6. TheseAll retrotransposons mobilize via a “copy-and-paste” mechanism involving a transcribed RNA intermediate that is reverse transcribed and integrated as a nascent cDNA into genomic DNA. However, there are essential differences in the retrotransposition mechanisms used by LTR and non-LTR retrotransposons Fig. . L1 mRNARecent studies have revealed a complex and somewhat paradoxical interplay between retrotransposons and their host genome in pluripotent cells. On one hand, retrotransposons have long been regarded as fundamentally selfish genetic elements  that, toHere, we review the restraint and activity of TEs in embryonic cells and later in development, as well as the unexpected promotion of pluripotent states by ERVs. We further appraise the convergent contributions to embryogenesis made by ERVs in distinct mammalian clades as evidence of an evolved strategy to avoid, or at least delay, host genome repression.Although there are spectacular examples of TE proteins underpinning functional innovation, such as in the placenta , regulatERV transcription independent of protein-coding genes has also been linked to pluripotency. Despite an apparent lack of retrotransposition activity, specific HERVs are actively transcribed in hESCs and are thought to influence pluripotency maintenance –32, 47. Human oocytes and zygotes (to the cell–cell stage) contain the highest percentages of HERV transcripts observed during development; these are almost certainly deposited maternally prior to embryonic genome activation . Abundanenv gene and is responsible for nuclear export and translation of viral RNAs , 4226, 4ral RNAs . Rec canral RNAs , 52. Conral RNAs  suggestev region , 54. Intv region . It is tv region , that hEHERV-H is another primate-specific retrotransposon  with a pXist, a prototypical lncRNA involved in X chromosome inactivation, TEs are a core component of lncRNA biogenesis [Xist, and a few additional examples, lncRNAs have proven difficult to evaluate functionally because, as well as containing TEs, lncRNAs are often expressed at very low levels [Long noncoding RNAs (lncRNAs) are RNA transcripts greater than 200 nucleotides long that possess no, or very little, protein-coding potential –60. Mostogenesis . Other tw levels . Howeverw levels , 63. Intw levels  reportedw levels , and in w levels , 44, 47.w levels .Alu element. HPAT5 is thus an unusual, and yet fascinating, example of retrotransposon-driven regulatory innovation.One particularly interesting lincRNA, HPAT5, is hypothesized to be involved in post-transcriptional gene regulation: HPAT5 binds AGO2, a core protein catalyzing microRNA (miRNA) processing , and thelincRNA-RoR, with its TSS located in a HERV-H element, represents an excellent example of a primate-specific TE found to modulate pluripotency [lincRNA-RoR is expressed more highly in iPSCs than in ESCs and can promote iPSC reprogramming [ESRG, which uses a domesticated HERV-H promoter, plays a role unique to human pluripotency [ESRG encodes an intact open reading frame (ORF) in humans, but possibly not in other primates, and is expressed exclusively in the human ICM and cultured pluripotent cells [ESRG knockdown compromises stem cell self-renewal and promotes differentiation, while ESRG overexpression aids reprogramming [More broadly, HERV-driven transcripts contributing to pluripotency networks unique to humans or primates are of particular interest. ipotency . Notablygramming , perhapsgramming . In anotipotency . Unusualnt cells . ESRG kngramming . These cTo discover new lncRNAs regulating pluripotency, Fort et al.  surveyedDomesticated TEs clearly play important functional roles in stem cell biology. However, TE repression can shift as cells transition through pluripotent states, as encountered during reprogramming. As a result, opportunistic TEs may mobilize, cause insertional mutagenesis and, potentially, compromise the integrity of reprogrammed cells , 48, 71.TE repression is dynamic during reprogramming. In a high-resolution analysis of mouse and human iPSC lines, Friedli et al.  found thThe machineries responsible for ERV regulation in ESCs are evidence of the complex relationships that can form between TEs and their host genome. Broadly speaking, to reduce the probability of retrotransposon-derived mutagenesis, mammalian genomes target ERVs with DNA methylation, heterochromatin-forming factors, transcriptional repressor complexes, proviral silencing factors, and post-transcriptional arrest or degradation of viral RNAs Table  19, 20,,20, 72. Even ERVs in accessible chromatin can be decisively silenced by DNA methylation. In mice, de novo DNA methylation is regulated by the canonical Zfp/Trim28/Eset machinery . KrüppelIt follows that models explaining ERV silencing are typically complex, which, at times, can lead to differing conclusions. For instance, the SNF2-type chromatin remodeler Atrx is another crucial component for IAP silencing that renders Eset-dependent heterochromatin less accessible  and is lAlu and SINE–VNTR–Alu (SVA) elements have also been reported by Klawitter et al. [Alu insertion in a cultured hESC line. L1 may, therefore, trans mobilize Alu and other SINEs during development, an important finding due to the high potential of SINEs to impact gene regulation [The early embryo is a viable niche for the generation of potentially heritable retrotransposon insertions. In particular, L1 mobilization in human and rodent embryos may drive somatic and germline mosaicism –101 and,r et al.  in severgulation , 104. Klgulation .Although both L1 and ERV retrotransposons are active in the mouse germline , 106, thSomatic L1 retrotransposition can also occur later in development. Over the past decade, it has become accepted that the mammalian brain, particularly cells of the neuronal lineage, accommodate mobilization of engineered and endogenous L1 elements –37, 108.Neuronal L1 insertions impart no obvious evolutionary benefit as they cannot be transmitted to subsequent generations. Thus, it is tempting to speculate that L1 activity is derepressed during neuronal commitment to serve a biological purpose for the host organism, analogous to the potential exaptation of ERV transcription for pluripotency maintenance and following the example of the vertebrate adaptive immune system, where domesticated TEs mediate V(D)J recombination and functional diversification through genomic mosaicism . SimilarThe mammalian genome clearly strives to limit TE activity in pluripotent cells. The silencing mechanisms involved are collectively complex and broadly potent and yet are also capable of great specificity and dynamism in targeting individual TE copies . In thisWhy are TEs active, and apparently essential, in the embryo? The relationship between TEs and the host genome is often referred to as an evolutionary arms race , 124. A Although not rejecting models based on serendipity or conflict, we highlight that ERVs and other successful TE families commonly arise as low copy number families and then rapidly expand over generations. This scenario could lead to TEs acquiring traits of early pioneers in a potentially hostile genomic landscape. Two not necessarily exclusive strategies can aid TE survival in this environment. One is stealth. For example, adaptation of the L1 5′ promoter (Box 2) enables evasion of host genome surveillance, leading to continuing L1 retrotransposition during development. That most new L1 copies are 5′ truncated, and lack the canonical promoter, also reduces their visibility to surveillance. Although this self-limits the capacity of new L1 insertions to retrotranspose, it also reduces pressure on the host genome to clamp down on L1 activity. The other strategy is gaining acceptance by being useful. ERV promoters are repeatedly found in pluripotency regulatory networks and may, therefore, be intrinsic to the pluripotent state. In this setting, efforts by the host genome to limit ERV activity could be detrimental to pluripotency. As such, ERVs may be able to propagate for longer than would be possible should the host engage in resolute inhibition. Importantly, these strategies are predicated on embryonic retrotransposition having potential for germline transmission, i.e., carrying risk for host genome integrity, as many studies have now found. Even after ERV families are no longer capable of mobilization, their inherent capacity for regulation, especially by solo LTRs, is retained and provides a long-term evolutionary incentive for the host genome to maintain at least one active TE family, as almost all mammals do. As such, rather than an arms race, conflict, or even symbiotic relationship, we would propose that pioneer ERVs adopt peaceful survival strategies and that intricate mechanisms for TE repression have evolved to allow the host genome to harness those strategies over time, allowing some ERV families to expand and, as witnessed in the embryo, securely embed themselves by becoming indispensable. In advocating this model, we emphasize that indispensability of ERV-mediated regulatory effects in natural pluripotency and embryogenesis in vivo is still an open question. While difficult to pursue in humans, genetic knockout or deletion of individual mouse ERVs or ERV families implicated in pluripotency is possible  and, indMyc using retroviral vectors [Programmed shifts in transcriptional and epigenetic states during embryogenesis have been studied primarily using in vitro systems. Embryonic stem cells (ESCs) are pluripotent cells derived from the blastocyst inner cell mass. Cultured ESCs are intensively used to study pluripotency, particularly in humans. Over the past decade, a core regulatory circuit incorporating the transcription factors Oct4 , Sox2, and Nanog –128 has  vectors , 132. Nu vectors . As for  vectors , 132Alu and SINE–VNTR–Alu (SVA) elements in trans [F, GF, and A) that are autonomous, as well as nonautonomous short interspersed elements (SINEs) retrotransposed by L1 [cis to form a cytoplasmic ribonucleoprotein particle (RNP) [The non-long terminal repeat retrotransposon long interspersed element-1 (L1) is the only autonomous, mobile human transposable element , 134. L1in trans , 136. Mied by L1 . L1 accoed by L1 . A full-ed by L1 , 137–139ed by L1  can alsoed by L1 . This aned by L1 , 140. L1ed by L1  and reveed by L1  activitile (RNP) . The RNPle (RNP)   are derived from exogenous retroviruses that, at some point, infected an individual organism’s germ cells, integrated into their genome, and were subsequently inherited by their offspring. ERVs are divided into class I, class II, and class III elements, based on the exogenous virus class that they are most similar to . Full-leansposon , 148. ERansposon   comprise about 8 % of the human genome . All HER


Thin-film elastomers (elastic polymers) have a number of technologically significant applications ranging from sportswear to medical devices. In this work, we demonstrate that graphene can be used to reinforce 20 micron thin elastomer films, resulting in over 50% increase in elastic modulus at a very low loading of 0.1 wt%, while also increasing the elongation to failure. This loading is below the percolation threshold for electrical conductivity. We demonstrate composites with both graphene oxide and reduced graphene oxide, the reduction being undertaken in-situ or ex-situ using a biocompatible reducing agent in ascorbic acid. The ultrathin films were cast by dip moulding. The transparency of the elastomer films allows us to use optical microscopy image and confirm the uniform distribution as well as the conformation of the graphene flakes within the composite. Rubber is most commonly processed in the form of a latex, a stable dispersion (emulsion) of polymer microparticles in an aqueous medium Elastomers are viscoelastic polymers with weak inter-molecular forces that exist in an amorphous state above their glass transition temperature. Elastomers can be classified as thermosets or thermoplastics; thermosets such as various rubbers require cross-linking by a curing process such as vulcanisation, whereas thermoplastics such as polystyrene are not cross-linked Elastomer products can be formed by a variety of techniques such as injection moulding, dip moulding, blow moulding, compression moulding, etc. There are a wide range of elastomer products which are produced worldwide predominantly by dip-moulding method. Such applications include gloves, plastic bags, condoms, coatings on metallic objects for corrosion protection, rubber grip coatings, etc. Dip-coating is used because it can form a thin, conformal coating over a range of arbitrary and complex shapes; this is not achieved by other moulding or coating methods. The coatings may either be left on the object (e.g. for corrosion or damage protection) or removed and utilised as a thin-film such as gloves and condoms.For thin-film applications such as condoms and gloves, where the elastomers are formed to thicknesses of less than 100 microns, traditional fillers with particle sizes in the micro-scale or larger are unsuitable. Nano-scale fillers such as graphene 22.12.1.1GO was produced by oxidising graphite according to a modified Hummers method 2.1.2® DLN-SD (Covestro AG). The NRL used in this work was Revultex® HR 8/012  SDN BHD). wPU at 40% solids or NRL at 60% solids content was blended with graphene oxide at 2.5 mg/ml using a magnetic stirrer at room temperature to obtain a homogenous blend to obtain the GO/wPU or GO/NRL blends. To obtain rGO, 1 M ascorbic acid The wPU used in this work was Impranil2.1.3wPU films were dipped on 32 mm OD smooth glass mandrels and NRL films were dipped on 22 mm OD smooth glass mandrels without any release agents or other processing aids, as shown in 2.1.4b/2Ax, where: T = tensile strength, Fb = breaking force , and Ax is the cross-section area of the ring. The formula used for elongation at break is: E = 100((2D + G−C)/C), where: E = elongation at break, %, D = distance between centres of rollers at break, G = circumference of one roller, C = circumference of the specimen.Tensile testing of graphene/wPU composite was performed followed the procedures in ASTM Standard D3492 – 97 3We used two ‘grades’ of GO, with flake size distribution of <1 μm , and 3–30 μm (large). 2 surface layer. Additional magnifications and images are shown in online supporting information. GO, on the other hand, did not offer sufficient optical contrast to be imaged optically in the NRL matrix. Excellent uniform dispersion of individual graphene flakes could be observed in the NRL matrix for rGO for small and large flakes. The NRL appears to stabilise the dispersion of the graphene effectively and prevent aggregation prior to or during the dip moulding process. The small rGO flakes were general flat, but occurring in small clusters. Large rGO flakes were generally individually dispersed, but not flat. This morphology of the different rGO flake sizes could correlate to the resulting mechanical properties described subsequently. This also confirms that the general assumption of graphene as a flat sheet Due to the good transparency of NRL thin-films, the distribution of rGO flakes inside the NRL matrix could be imaged by optical microscopy in reflectance mode . In ordeSince the wPU used here is an anionic aliphatic polyester and GO is also anionic This could be attributed to the morphology of the small and large graphene flakes within the elastomer matrix. The built-in undulations in the large graphene flakes compared to the flat small graphene flakes is attributed to the higher ultimate elongation whereas the same morphology combined with the clustering of small graphene flakes is attributed to the lower ultimate elongation. There are two major contributing factors to the different aggregation rates of small and large rGO flakes. Rheology measurements on similar concentration dispersions of small and large GO flakes have shown that larger flake dispersions have higher viscosities, especially at low shear rate and amplitudes, both in the GO dispersion The above results, taken together, demonstrates that the addition of a small amount of optimum graphene filler to NRL and wPU significantly improves the mechanical properties of these elastomers in their thin-film form.One of the various ways to test the integrity of elastomer thin-film products, such as gloves and condoms, is electrical conductance test. This is the only standard non-destructive test that is integrated into the production flow, where electrical conductivity across the elastomer thin-film is interpreted as a flaw such as a pin-hole leading to product rejection. To avoid invalidating this unique industrial standard test, it is essential that the addition of a conductive filler such as graphene should not introduce electrical conductivity to the thin-film product. Owing to the low graphene loading in the composites studied here, which is well below the percolation threshold, no electrical conductivity is observed in the thin-film composite samples tested here.4In conclusion, we have developed two varieties of water-based graphene/elastomer composite thin-films, which are 10s of microns thick. In the case of wPU, the graphene was incorporated as GO followed by in-situ reduction by ascorbic acid, whereas in the case of NRL, the graphene was first reduced to rGO and then added to the NRL so as to not disturb the stability of the latex emulsion. The graphene was well-dispersed as monolayers within the composites. In both composites, the elastic modulus was improved by 50% by the addition of just 0.1 wt % of large rGO flakes, while the elongation to failure was either maintained or improved. This is critical; as summarised in Ref.


The STOPAH trial was a double-blind, 2x2 factorial, phase III randomised clinical trial assessing the treatment of prednisolone and pentoxifylline in patients with severe alcoholic hepatitis; a study that aimed to evaluate 28-day mortality .At the time of trial development, the benefits/harms of pentoxifylline in this patient population were unknown. Prednisolone had a significant though uncertain evidence base. No treatment interaction was assumed yet there was uncertainty about its effect. Therefore, pre-specified stopping rules to assist decision making in stopping treatment arms were required.There was no published methodology on stopping rules for factorial trials, so a design based on the Peto-Haybittle  rule wasAn independent data monitoring committee assessed these stopping rules after 200, 400 and 800 patients had reached the primary endpoint. The stopping rules were not met at any of the three interim looks. The results of the STOPAH trial have recently been published .


Deoxyribonucleic acid or DNA based sensors, especially as humidity and alpha particle sensors have become quite popular in recent times due to flexible and highly optimizable nature of this fundamental biomaterial. Application of DNA electronics allow for more sensitive, accurate and effective sensors to be developed and fabricated. In this work, we examined the effect of different humidity conditions on the capacitive and resistive response of Aluminum (Al)/DNA/Al Schottky barrier structure when bombarded by time-dependent dosages of alpha particles. Based on current-voltage profiles, which demonstrated rectifying behaviours, Schottky diode parameters such as ideality factor, barrier height and series resistance was calculated. Results observed generally pointed towards a decrease in the resistance value from the pristine to the radiated structures. It was also demonstrated that under the effect of humidity, the capacitance of the DNA thin film increased from 0.05894 to 92.736 nF, with rising relative humidity level. We also observed the occurrence of the hypersensitivity phenomena after alpha irradiation between 2 to 4 min by observing a drop in the series resistance, crucial in the study of DNA damage and repair mechanisms. These observations may also suggest the exciting possibility of utilizing Al/DNA/Al Schottky diodes as potentially sensitive humidity sensors. The quantity of water vapor in the atmosphere is called humidity, which affects all environmental biological and chemical processes. Humidity also negatively affects various industrial-manufacturing methods if proper steps are not taken. As such, humidity level in terms of relative humidity (RH) are closely monitored to reveal fluctuations in situations ranging from high to low temperatures or in mixtures with other gasesFlexible, chipless and wireless humidity sensors are built based on the difference in dielectric constant (capacitive), proton/ionic conduction (resistive), refractive index , frequency (impedance) or mass of the active material against humidity level68910et al. and Otsuka et al. observed the RH value effect on the conductance of samples involving various DNA molecules. They reported that poly(dC)-poly(dG) sample demonstrated a higher sensitivity to RH13et al.et al. observed that the conductivity of DNA of length 140 nm demonstrated insulating behaviors when placed in dry environment (about 30% RH). This was in contrast to improved conductivity under moist environment (80–90% RH)et al. and Yamahata et al. observed and reported that the conductivity followed the increase in humidity level exponentially in dsDNA and single-strand DNA (ssDNA) due to the absorption of water molecules to the nanostructured film surface17+2 and Ni+2 mixed with DNA. A color transition from blue to red with change in the UV absorption due to the humidity effect was observed. This type of sensors are flexible, non-hazardous and cheap to fabricateet al. used DNA functionalized carbon nanotube (DFC) networks to develop a field effect transistor (FET)-based humidity sensor. They reported that the charge transfer mechanism between the DNA and the water molecules caused the exponential variation of conductance of the DFC network with RHHan et al. observed that the ionic conduction through water layers under atmospheric conditions was the dominant conduction mechanism by using the frequency (100-1 KHz). Utilizing micro- and nanoelectrodes of DNA film, they observed that the semicircle becomes smaller in the high frequency range at high humidityet al. demonstrated that the sensitivity of Graphene Oxide (GO) at 1 KHz was higher than that at 100 Hz and 10 KHz of frequencieset al. meanwhile found that for carbon film, the capacitive response at 1 kHz was over 200% for RH shifting from 11 to 95%, compared with other frequenciesStructures of DNA are strongly influenced by the environmental conditions due to their polymorphic nature212527Generally, the experiments involved measuring various diode parameters against bombardment of alpha particles under various humidity conditions. As such, the data provides information of humidity dependent electronic parameters of sensitive DNA sensing material. The results, as clearly observed shows a distinct behavior specific to the humidity level used. These features, we believe, provides an effective avenue towards accurately and effectively sensing humidity fluctuations using the DNA molecules, which are totally biodegradable and abundant in nature besides having a high degree of flexibility. It is also very well known that humidity highly influences the semiconducting behavior of DNA, forming a solid reason behind the motivation into utilizing DNAs as a humidity sensing organic material. The experiments conducted in these studies have also brought to light the possibility of interrogating various important DNA related processes especially damage and repair mechanisms based on the occurrence of the interesting effect of hypersensitivity.In this current study, we developed and utilized for the first time, a novel Al/DNA/Al surface-type Schottky diode as the humidity sensor. The fabricated Schottky diodes are further studied by investigating the fundamental changes induced by different time-dependent dosages of alpha particle irradiation on the DNA molecules. This was achieved by measuring its electrical characteristics under controlled chamber humidity to establish its humidity sensing potentials.293018At high humidity levels, water molecules play an important role towards improvement in conductivity in which case, the increase in electron transfer along the dsDNA helix may lead to the improvement in charge conduction. The charge transfer phenomena may therefore play an important role in the sensing mechanism, which could have primarily lead to the insignificant base-line shift and faster recovery time. This change in the electrical properties of the Al/DNA/Al structure due to the change in RH may therefore be generally attributed to the absorption of water molecules and the increase of the number of holes due to tracks made by the alpha particles upon bombardment.In is known that alpha particles lead to primary and secondary ionizations in atoms upon interaction. These processes in turn produce several types of ions and excited molecules in cells ultimately causing intermolecular bond biomolecule cleavage. Cleavage occurs within the cytoplasm and other intracellular components besides the cell nucleus. As such, DNA molecule being double stranded exhibits cleavage in one or both the strands. The DNA molecule has characteristic capability to repair single-strand damage; but a scission in double-stranded DNA repair to its original form is not trivial. However repair of double-stranded scission of the DNA molecule may cause gene mutations as a result of the exposure to radiationThe relationship between humidity and the resistance within the range from 20 to 99.9% RH is demonstrated in 2O molecule concentration and displacement currents, and the concentration of charge carriers doped by water moleculeset al., who in their work indicated that the reason for the low output signal current from the networks may be due to it being unsuitable for use in low RH sensors. Since the output signal current of the detector rises exponentially with increase in RH, the device display elevated sensitivity especially at higher RHAs discussed, the resistance in general decreased exponentially , while tThe resistance meanwhile decreased exponentially and was attributed to adsorption of water molecules by the DNA. This change is explained as follows; DNA consists of three portions; bases, sugars, and phosphoric acids. The hydrophilic phosphoric acid around the base pairs of DNA caused the water molecules to be easily absorbed and form hydrogen bonds between the phosphoric acid and the water molecule. Resistance values quickly decline as the RH increases and tend to saturate for humidity above 99.9%. These phenomena agree with ionic conduction at higher humidity scaleet al. studied the humidity influence on the electrical conductivity of DNA thin film1 and OH− species produced by water adsorption. The ions separate and recombine according to the Grotthus mechanism, which describes the passing of protons through the cooperation of neighboring water moleculesOtsuka 1039o is the initial capacitance, ε represents the relative dielectric constant, εo the absolute permittivity, A is equal to the area of the surface and d the distance between the electrodes. where C1 and m2 are the constants. In the case of relative capacitance, where H is the relative humidity level and mFrom et al.4243Sensitivity is calculated using the following relation;Sensitivity = Capacitance at high humidity (99.9%) − Capacitance at low humidity (20%)/(high humidity - low humidity) as shown in The dielectric constant from the fits made from 3445The surface morphology of the Al/DNA/Al thin films was examined using Atomic Force Microscope (AFM)  and shown in 1030The profiles in The electrical characteristics of the Schottky barrier height connections are very sensitive to the features of the metal-semiconductor (MS) interface. As such, the I–V characteristics of the connection are suitable displays of the interface features. For a Schottky barrier diode, the thermionic emission theory predicts that the I–V characteristics at forward bias V are given by* = 120 Am−2K−2 is the effective Richardson constant for Alb is the barrier height (in eV). For values of V > 3 KT/q, the ideality factor can be obtained from where Aet al. obtained under different humidity conditions. The highly rectifying curve and inverted S shape in this work at high relative humidity are clearly attributed to water molecules adsorbed by the DNA. Dielectric constant increase lead to the increase of the ionic conduction+ and OH− and the different mobility between H+ and OHThe ideality factor determined from the slope of the linear region of the forward bias (ln (I)–V) characteristic through the relation in 52S = S) versus voltage of the surface type Schottky diode is demonstrated in S values were the highest for 8, 2 and 6 min, respectively in reducing order, followed by the sample radiated for 4 min and non-radiated at 76% RH. At 99.9% RH meanwhile, the series resistance values were the highest for 8 min, non-radiated and 2 min in reducing order followed by the sample radiated for 4 and 6 min. However above 2.0 V, the series resistance values become insignificant.The values of series resistance are calculated from the junction resistance formula R2O molecules  and intermolecular features under humidity effectAccording to Ha 59S) were extracted. The results generally indicate an increase in the ideality factor with increasing humidity, while the series resistance and the barrier height values register attenuations with increase in the humidity. The influence of RH on capacitance and resistance of the sensor was studied in the humidity range of 20 to 99.9% RH. The sensors fabricated in this work demonstrated higher sensitivity across all the humidity range tested. Results also indicated that with the rise in humidity, capacitance increases while the device resistance dropped. Resistance and capacitance-humidity relationships recorded significant variations in the range of 50–99.9% and 45–75% RH. The resistance of the film generally reduced from a high of 1678 to a low of 6.523 KΩ and 1512 to 1.801 KΩ for the non-radiated and 2 min of alpha irradiation, respectively. The series resistance value increased after the irradiation for 2 min, followed by a decrease at 4 min (≈53.0755 KΩ) for characteristic to the hypersensitivity phenomena, which may correspond directly to the damage and repair mechanism in DNA, It was also shown that under the effect of increasing humidity, the capacitance of DNA thin film increased from 0.05894 to 92.736 nF for both the non-radiated and irradiated samples. These observations show the exciting possibility of utilizing Al/DNA/Al Schottky barriers as potentially sensitive humidity sensors and may even provide a platform to allow the study of charge transfer mechanism in DNA damage and repair processes.Humidity sensing properties of the DNA films deposited by drop casting method were investigated. Electrical characterization studies were carried-out using I–V profiles under humidity fluctuations and Schottky diode parameters such as ideality factor (n), barrier height (ф) and series resistance  amplification. The procedure starts with the collection of minute quantities of mycelium (0.1–1.0 g) from a colony of the fruiting body (Stipe) of a mushroom species using a sterilized tweezer. Standard procedures according to Hibbett −5 mbar, whereas the deposition rate was maintained at 0.1 nm/s and the gap length and width of gaps (between the electrodes) was 25 mm and 400 μm, respectively. After which, formation of the organic DNA layer was carried-out by using a micro-syringe  containing the pre-prepared DNA solution (concentration of 1.80 ng/μl). The fabricated device was then kept in a 1 K Cleanroom to allow self-assembly overnight. Sample irradiation by alpha particles was achieved using a 241Am source with an activity of 150 nCurie and t1/2 of 457 years for periods of 2, 4, 6 and 8 min. The top and cross-sectional view of the Al/DNA/Al surface-type Schottky diode fabricated is shown in A glass substrate was cleaned for 15 min using deionized water  in an ultrasonic cleaner and later dried in a dust-free environment. Thin films of Al (thickness ~325 nm) were deposited on the glass substrate using an Edward Auto 306 vacuum coater with a diffusion pumping system  and Al metal wire  of 99.999% purity). While depositing the Al thin film, the pressure inside the chamber was kept at 10in-situ capacitance and resistance values versus RH measurements of the Al/DNA/Al sensor at ambient temperature (25 ± 1 °C), were carried-out by placing the device in the hermetically sealed humidity chamber capable of providing a humidity range of 20–99.9% RH. The humidity meter and the Al/DNA/Al placed in a closed chamber were exposed to irradiation of alpha particles in a controlled humidity environment. The chamber has built-in input and output valves for gas flow. Nitrogen gas was then passed through water and then channeled into the chamber to control and maintain a certain humidity level within the chamber. LCR Meter (Instruments Instek LCR-829 LCR Meter) was used to measure the capacitance of the sensor. The How to cite this article: Al-Ta’ii, H. M. J. et al. Humidity influenced capacitance and resistance of an Al/DNA/Al Schottky diode irradiated by alpha particles. Sci. Rep.6, 25519; doi: 10.1038/srep25519 (2016).


Turning during locomotion involves considerable changes of the body’s center of mass and reduced stability, as well as lower limb kinematics and kinetics. However, many previous studies have been carried out to evaluate the effectiveness and applications of orthotic insoles as well as different types of orthotic materials in various clinical symptoms, which are focused primarily on straight line walking. Hence, the influence of custom-made insoles with the use of advanced three-dimensional spacer fabrics on biomechanics parameters in terms of plantar pressure distribution and lower limb electromyography during turning movement was studied.Twelve subjects performed 180-degree turning at a speed 3.07-3.74 km/h for five successful trials under 3 insoles conditions: wearing traditional ethylene vinyl acetate insoles and two different spacer-fabricated insoles, with the plantar pressure and lower limb muscle activity collected simultaneously. Turning movement was broken down into 3 phases for analysis: Turning initiation, turn around and turn termination.p < 0.05). Compared to the traditional insoles, insoles made of a spacer fabric reduced the peak pressure (>12 %) and pressure–time integral (>13 %) in toes, metatarsal head 1 and metatarsal heads 2–3 at turning initiation; (>15 %) and (>17 %) in medial midfoot and medial heel at turn around. Insoles with spacer fabrics on the top and middle layer reduced both pressure parameters (>18 %) in toes and MTH 1 at turn termination. In terms of muscle activities, insoles with two-layer spacer fabrics could lower maximum muscle activities of vastus lateralis  at turn around.There was a statistically significance difference in plantar pressure between the traditional insoles and the insoles made of a spacer fabric as the top layer (Insoles with different fabrications could offer various pressure offloading patterns across the plantar and muscle activity changes while turning. Insoles with a spacer fabric on the top tend to reduce plantar pressure loading at different regions during turn initiation and turn around phases, while two-layer spacer-fabricated insoles may contribute to reduced vastus lateralis muscle activation during turn around. More importantly, this study provides a new dimension in the potential use of the textile-fabricated insoles which may widen the range of insole materials selection in the design and development of insoles so as to enhance the effectiveness of orthotic treatment. Turning is a common occurrence, accounting for approximately 35-45 % of all steps in activities of daily living –3. It isFoot orthotic treatment is one of the primary means to handle various foot problems such as reducing the occurrence or recurrence of ulceration which is due to the excessive shearing together with abnormal levels of repeated pressure that occur within the foot leading to severe damage to soft tissue , 10. EveCustom-made orthotic insoles, which are designed to relieve and reduce plantar pressure over a wider surface area, have been widely used and highly promoted in the treatment of foot deformities and/or neuropathic conditions of the foot –24. TheyTo improve the quality of foot rehabilitation treatment, a thorough understanding of foot plantar loading behaviors and lower limb muscles activation patterns when foot orthoses are worn during the process of turning is imperative. The purpose of this article was to explore whether the novel textile materials could have a better performance in plantar pressure and muscle activity reduction during turning in healthy participants. Hence, the specific aim of the study was to examine the changes of plantar pressure distribution and lower limb muscle activity in response to custom-made textile insoles and traditional insoles during different phases of turning. It was hypothesized that 1) the overall distribution of plantar pressure and muscle activities associated with turning could be reduced, 2) the magnitude of pressure and muscle activities reductions vary at different turning phases by the use of textile insoles made of spacer fabrics.In this within-subject repeated measures study, the participants wore three types of insoles made with different materials combinations. The plantar pressure distribution and muscle activity were measured during the wear trials.2 (SD: 2.6). Their foot sizes ranged from European 40 to 43  and 37 to 40 . All participants signed a written consent in accordance with the ethics policy on human subjects as stipulated by the university before participation. The experimental protocol was approval by the Human Subjects Ethics Sub-committee of the Research Committee.Twelve healthy subjects, 6 men and 6 women, who did not have any history of orthopedic or neurological conditions and were free of foot pain during the time of study participated in the study. Their average age was 23.0 (SD: 4.3); and body mass index (BMI) was 20.3 kg/mWhile the subjects were in an upright sitting position , the foot contour with the subtalar neutral position was captured by a contact digitizer of the Amfit® technology system . The CAD/CAM mill connected to the digitizer receives the foot images and fabricates the 3D bottom layers of the insoles by a certified orthotist/prosthetist. Each participant was fitted with 3 pairs of custom-made multilayer insoles that were made with the same combinations of materials as shown in Table The data for each subject were collected on the same day. The subjects went through a 4-h acclimatising period of each insole wear  for 3 to 4 days before the data acquisition. Previous studies have found that subjects, especially those with healthy foot conditions, probably feel uncomfortable for the contoured shape of the insoles and the overall comfort is likely influenced by arch comfort . In thisPressure was measured at 160 Hz using the Pedar®-X in-shoe pressure measurement system  on the dominant foot. Each Pedar® insole sensor, which was 2 mm in thickness and consisted of sampling with 99 sensors, was fitted in accordance with foot size and placed inside each shoe between the foot and the insole. The participants wore the standard sports shoes, socks and insoles provided during data collection. The plantar pressure map was divided into nine subareas: hallux, toes, metatarsal head (MTH) 1, MTHs 2–3, MTHs 4–5, medial and lateral midfoot (MF) and medial and lateral heel by using the Novel Multimask software  as shown in Fig. th order Butterworth low-pass filter with a band-pass filtered at 10–500 Hz and stored for office analysis . The sEMG data were analyzed by converting the data into root mean square values, which were calculated for a 400-ms window. The resultant maximum and mean amplitudes were averaged under each condition and normalized to the MVC of each subject which was expressed as a percentage. The average of five successful trials was then used for data analysis.During the gait trials with each insole condition, surface electromyography (sEMG) data for the vastus lateralis, tibialis anterior and lateral gastrocnemius muscles were simultaneously collected with the plantar pressure distribution by using a 10-channel Datalog sEMG system at a sampling frequency of 2048 Hz . Bipolar Ag/AgCl surface electrode pairs were placed parallel to the alcohol cleaned and shaven surface of the skin overlying the corresponding muscle bellies. The electrodes were 10 mm in diameter and had 22 mm inter-electrode separation distance. Electrode placement followed the recommendations of Surface ElectroMyoGraphy for the Non-Invasive Assessment of Muscles (SENIAM) . All sEMAll of the data are reported as mean (SD). The IBM SPSS software (version 16) was used for data analysis. Two-factor repeated measures analysis of variance (ANOVA) was performed to explore each measurement of the plantar pressure distribution, and muscle activity across the three insole conditions. There were two within-subject independent variables for each measurement: type of insole and subarea; and type of insole and muscle. In addition, one-factor repeated-measures ANOVA was used to further examine the difference between each dependent variable in each measurement among the three insole conditions. Bonferroni post hoc test was used for multiple pairwise comparisons when there was a demonstrated significant difference in both types of ANOVA.Table 2,22 = 18.5, p < 0.001; F8,88 = 20.6, p < 0.001 respectively), and during turn termination . There is no interaction effect during turn initiation. The two-way interaction (insole-subareas) is only significant for the PP (p < 0.02) during turn termination. The post hoc tests indicate that when compared with insole I, there were statistically significant differences in PP during the turn initiation (120.5 vs. 105.1), turn around (97.0 vs. 87.2), and turn termination (120.1 vs. 112.4) in insole II. Insole II resulted in lower peak pressures compared to insole I during various turning phases. Reduction in PP was also found in insole III during turn initiation  and turn termination . No significant differences were shown with reference to turn around.The insoles and subareas have statistically significant effects on PP during turn initiation (Fp < 0.05). Statistically significant pressure differences were also found in medial MF and medial heel at turn around. The Bonferroni pair-wise comparison showed significant pressure differences at toes (mean difference (SD): 34.4 (5.5), % change: 24.0 %, p < 0.001), MTH 1 (22.7 (8.4), 16.3 %, p = 0.01) and medial MF (9.6 (1), 16.0 %, p = 0.012) during turn initiation, and medial MF (11.6 (3.0), 15.8 %, p = 0.041) and medial heel (23.7 (6.8), 19.1 %, p = 0.005) during turn around between insole I and insole II. Similar trend of pressure reduction was also observed in Insole III at hallux (27.5 (0.7), 18.4 %, p = 0.011), toes (26.4 (1.8), 18.0 %, p = 0.007) and MTH 1 (23.0 (0.3), 18.7 %, p = 0.03) during turn termination when compared to Insole I. No significant differences were shown with reference to heel areas during turn initiation and termination, while no significant difference was found in forefoot areas during turn around. When comparing PP in different phases as shown in Fig. The results in Table 2,22 = 8.0, p = 0.002; F8,88 = 7.8, p < 0.001 respectively), turn around  and turn termination . Nevertheless, none of the two-way interaction (insole-subareas) is significant. The post hoc tests indicate that insole II reduced PTI at turn initiation  and turn around  compared with insole I.Analysis of the PTI yielded similar results, whereby the insoles and subareas have statistically significant effects on the PTI during turn initiation (Fp < 0.05) amongst different insole conditions. Significant differences were also found in hallux, medial MF and medial heel at turn around. In the pairwise comparison, significant PTI differences at toes (9.4 (2.0), 23.7 %, p = 0.001), MTH 1 (7.8 (1.0), 19.5 %, p = 0.007) during turn initiation, and hallux (8.8 (0.4), 19.2 %, p = 0.02), medial MF (5.3 (0.9), 17.2 %, p = 0.025) and medial heel (11.0 (5.3), 24.5 %, p = 0.007) during turn around between insole I and insole II. Similar trend of PTI reduction was also observed in insole III at toes (9.4 (2.0), 18.5 %, p = 0.024) and MTH 1 (7.9 (2.4), 23.9 %, p = 0.013)) during turn termination when compared to insole I. No significant differences were shown with reference to midfoot and heel areas during turn initiation and termination.With reference to Table Table 2,22 = 4.9, p = 0.017) is only significant for the maximum muscle activity during turn termination. The two-way interaction (insole-muscle) or pair-wise comparison of insoles is not significant (p > 0.05). The results in Table p < 0.05) is detected only in the vastus lateralis muscle across insoles during turn around, where insole III reduced the maximum muscle activity (3.8 (0.1), 16.9 %, p = 0.044) compared to insole I in the pairwise comparison. No significant differences were found in any muscle group amongst insole conditions during turn initiation and termination. Besides, when comparing maximum muscle activity in different phases as shown in Fig. The main effect of the muscle type , turn around  and turn termination  but the two-way interaction (insole-muscle) is not significant (p > 0.05). The post hoc tests indicate that reduction in the mean muscle activity in insole I during turn initiation , turn around , and turn termination  when compared to insole II. Results shown in Table The main effect of the insole type is significant for the mean muscle activity during turn initiation , textile-fabricated insoles could reduce pressure loading in various plantar subareas during different phases of the turning. In this study, when the insole consists of one layer of textile material (i.e. insole II), the PP and PTI are significantly reduced mostly in forefoot regions such as Toes, MTH 1 and MTHs 2–3 at turning initiation and a significant reduction in the medial side of midfoot and heel are found at turn around. In regard to the insole composing of two-layer textile materials (i.e. insole III), the pressure loading is significantly reduced in toes and MTH 1 during turn termination. This may be attributed to the soft sandwiched structure of spacer fabrics that spacer fabrics are used as the top layer of insoles II and III with direct contact with the foot for better resilience and recovery performance , 34, thuIn this study, the redistribution of the body center of mass may also induce the turn-related sensory feedback which leads to activate more muscles around the knee of the inner limb during the stance phase to enable body support and maintain whole body stability while turning –50. For With respect to the noticeable decrease in the maximum and mean muscle activity of almost all of the muscle groups after the use of textile insoles during different phases of turning, the reason may be related to the material features that make up the insoles. For instance, the viscoelastic and shock-absorbing properties of Poron® together with the transversal compressible spacer fabric with a high pile height in insole II could possibly reduce the frequency of the overuse of the foot . This maMost previous studies have been conducted on investigating the effects of different orthotic insoles on plantar pressure distribution and muscular activities during straight line walking. The major novelty of our work is focusing on turning which had been further differentiated into turn initiation, turn around and turn termination. Related studies have reported that plantar peak pressure is redistributed across the plantar with the insertion of contoured shape insoles when compared to no insole condition. In Redmond’s study, custom made insoles with EVA insertion at heel posts could reduce peak pressure 12.7 % and 17.2 % at heel area when compared to prefabricated insole and control shoe conditions respectively . Hinza iIt is noted that there are some limitations in this study. The sample size is relatively small and therefore might have limited the generalizability of the results. The current turning task was merely a single subset of turning gait, which may not be representative of all types of turns that occur during daily ambulation and of all human turnings. More rigorous and various types of turning in daily tasks would be necessary for further studies. Also, it is recognized that only the immediate effect of the insole was tested. Further research is required to evaluate the long term effects of the materials on pressure loading and to investigate the durability of the materials when exposed to prolonged wear and tear. As footwear comfort is emerging as an important research field, further work is necessary to identify the determining factors. It is recognized that the use of young healthy adults may be responsible for the lack of differentiation between the effects of the material on plantar and muscle response because they may have been able to modify their gait or plantar loading to prevent any foot areas from excessive stress. Nonetheless, the study provides preliminary evidence that supports the use of spacer fabrics in designing orthotic insoles, thereby providing a basis for future studies to highlight the high flexibility of spacer with its significant thermal features in further developments.Turning is one of the major motions and makes up a large portion of steps taken during activities and therefore should be taken account of during lower limb kinematic and kinetic investigations of different insole designs. The present study has provided a novel approach on the use of spacer fabricated insoles, which not only reduces/redistributes plantar pressure, but also lowers muscle activity of the lower limbs during various phases of turning. The wide availability, versatility and cost effectiveness of knitted spacer fabrics and/or advanced textile materials also allow practitioners to widen their selection of insole materials in the design and development of orthotic insoles. It is suggested that a spacer fabric is used as the top layer while a soft and cushioning material is used as the middle layer for orthotic insoles, and that different pile heights and thicknesses be used for patients with different needs and support requirements.EVA, ethylene vinyl acetate; MF, midfoot; MTH, Metatarsal head; MVC, maximum voluntary contractions; PP, peak pressure; PTI, pressure time integral, sEMG, surface electromyography


However, diameter dependence of thermal conductivity of SWCNTs received less attentions. So far, diverse trends of the diameter dependence have been discussed by different methods and all the previous results were based on empirical interatomic potentials. In this paper, we emphasize to clarify accurate κ values of SWCNTs with different diameters and in-plane κ of graphene. All the studies were under the framework of anharmonic lattice dynamics and Boltzmann transport equation (BTE) based on first principle calculations. We try to infer the right trend of diameter dependent thermal conductivity of SWCNTs. We infer that graphene is the limitation as SWCNT with an infinite diameter. We analyzed the thermal conductivity contributions from each phonon mode in SWCNTs to explain the trend. Meanwhile, we also identify the extremely low thermal conductivity of ultra-thin SWCNTs.The effects of temperature, tube length, defects, and surface functionalization on the thermal conductivity ( In their research, the κ of SWCNTs is smaller than graphene and exists a minimum value at a certain diameterκ for SWCNTs and compared with graphene, which can be regarded as the SWCNT with diameter approaching infinity in structural configuration.In the previous study of density functional theory (DFT), the vibrational properties of SWCNTs are studied including the radial breathing modes (RBM), tangential totally symmetric modes, zone folding approximation for phonons of nanotubes, phonon dispersion relations with the helical Brillouin zone, and the electron-phonon coupling effects15κ of SWCNTs with different diameters. We try to investigate the high κ values of the SWCNTs accurately and clarify the relationship between κ and diameter. The calculation results agree very well with the experimental data that have been reported. From the first principle calculation results, we can infer that κ of SWCNTs increases with diameter decreasing, and κ of graphene shows to be the lowest boundary value of these SWCNTs. We also study the thermal transport in ultra-thin SWCNTs with diameters 2.07 Å and 2.71 Å. We demonstrate that the ultra-thin SWCNTs possess relatively lower thermal conductivities than graphene, which agrees with the recent MD simulations resultIn this work, we applied the method which considers the anharmonic three-phonon scattering based on ab initio calculation and combines with BTE to study the κ obviouslyκ for these SWCNTs and graphene at room temperature are displayed in κ of graphene from our calculation is 3409.08 W/mK. This result excellently agrees with recent research by first principlesSeven armchair SWCNTs and one chiral ultra-thin SWCNT  were calculated. In previous report, the chirality of SWCNTs does not effect κ of SWCNTs increases with the diameter descending from 10.85 Å to 4.07 Å. In this diameter range, the diffusive phonon thermal conductivity κ of SWCNTs are larger than in-plane κ of graphene. From κ along the tube direction will approach to the graphene in-plane value.From the data in κ contribution in percentage from each phonon mode of SWCNTs and graphene. κ along the tube-direction for SWCNT, SWCNT and SWCNT respectively. Color bar indicates the contribution magnitude of each phonon mode. Red data point on phonon spectrum represents the large contribution phonon mode to κ. From the phonon spectrum of SWCNTs we see that there are four acoustic phonon branches and two degenerated transverse acoustic branchesκ along tube-direction mainly originates from four acoustic phonon branches and one optical branch near the Γ point. Comparing with the phonon spectrums of SWCNT and SWCNT, we can see that with the diameter increasing there are more optical phonon branches participating to the lattice thermal transport. These optical phonon modes concentrate on the area away from Γ point in k-space at relatively low frequency. That means there are more optical phonons participating into the optical-acoustic scattering process. This mechanism causes the total calculated κ in tube-direction descending with the diameter value increasing. This trend is the same with previous MD simulation study by Thomas et al.κ in SWCNT becomes weaker in the SWCNT and SWCNT. In these three phonon dispersions shown here, the phonons with frequency higher than 30 THz contribute little to the κ. This results is the same with the results of spectral energy density method based on MD simulationTo analyze the mechanism behind the phonon transport behavior, in κ of graphene. In the 3D phonon dispersion, we use the color to map the different contributions to the κ along κ. From the contributions in 3D phonon dispersion, we can see clearly the out-of-plane flexural (ZA) modes contribute the most to the total κ along κ at room temperature21κ contribution along κ contributions of phonon modes distribute in two in-plane lattice directions that are equivalent in terms of geometric symmetry. And from the average κ contributions of ZA modes map on 2D BZ, the in-plane isotropic property is revealed clearly. In our method we calculate the in-plane phonons diffusive transport behaviors of graphene, and there do not exist the zigzag and armchair boundaries in our model. That is the origin of isotropic κ of graphene.κ of ultra-thin SWCNT and SWCNT are much lower than graphene. From cross-sectional view of their atomic structures  and SWCNT, the data points with very small κ contribution (<0.1%) concentrates in the range of 1 ~ 10 THz, due to the strong scattering among these phonons. This is consistent with our previous analysis in κ of graphene. It indicates clearly that the contributions from ZA modes are much higher than that from other modes, and in another way reflect the same information in Summarizing the information from κ contributions information verse frequency , SWCNT and SWCNT, while for graphene, 90% of in-plane κ originates from phonons below 12.95 THz. However, for SWCNT because the much more optical phonon modes each one carries a little contribution to κ, the 90% contribution threshold is increased to 17.15 THz.In cumulative requency , we can κ of graphene for comparison with the same method. Our results suggest that lattice thermal conductivity of SWCNTs increases with diameter descending and graphene behaves as lower limit of SWCNTs with infinite diameter. We also indicate that the ultra thin SWCNTs have relatively small κ. From the analysis of each phonon mode contribution to overall κ (phonon polarization), we clarify that the SWCNT with larger diameter has more optical phonons participating in the scattering process, leading to the reduced κ with diameter increasing, and finally approaching the graphene limit. For graphene, by analyzing phonon mode specific group velocity and phonon lifetime, we observe the dominant role of ZA modes, originating from the overwhelming enhancement in their phonon lifetime compensating the low phonon group velocity. However, due to the limitation of the computing resource and the huge computational demand, the κ of SWCNTs with larger diameters do not exhibit here. More calculations are still needed to reveal the real trend about the κ behavior of SWCNTs with much larger diameters. Nevertheless, we expect that our work provides deeper insight into the phonon transport mechanism in small diameter carbon nanotubes and offers a clear and reliable trend for device applications involving thin carbon nanotubes in the future.In conclusion, we studied the lattice thermal conductivities of seven armchair SWCNTs from  to  and one chiral ultra-thin SWCNT through the lattice anharmonic dynamic coupled with BTE method based on the first principle calculations. We also provide the in-plane Thermal conductivity is introduced through Fourier′s lawJ is the net heat flux, κ is the thermal conductivity tensorJ can also be expressed as:where V is the system volume, p and q denote the phonon branch and wave vector respectively, vg is the phonon group velocity and δf is the net diffusive change of phonon distribution. In steady state, the rate of phonon distribution total change is zero. This condition renders the BTE form:where where the diffusive term can be treated as linear with the gradient of temperature:Combining Eqs τ is the phonon lifetime, Cph is the specific heat capacity of system:where Cph and vg from the harmonic phonon dispersion calculated by the second order IFCs, and get the scattering rate 1/τ from the third order IFCswhere s2) electrons, with the 2s2 and 2p2 electrons of carbon considered as valence electrons. The kinetic energy cutoff of wave functions was set as 500 eV, and Monkhorst-pack k-mesh 4*4*24 including Γ point was used to sample the Brillouin Zone (BZ). A vacuum layer 10 Å was used to hinder the self-interactions between cylinders arising from the employed periodic boundary condition. All geometries were fully optimized with the Hellmann—Feynman force tolerance is Both second and third IFCs were obtained from the first-principle calculations. Before the IFCs calculations we optimized the structures of each case in unit cell. All first-principles calculations were performed based on the density functional theory (DFT) as implemented in the Vienna Ab-initio Simulation Package (VASP)4245κ, anharmonic third order IFCs are also necessary. The same supercell and k-mesh were used to get the anharmonic third order IFCs, and interactions between atoms were taken into account up to forth nearest neighbors. The total number of third order IFC evaluations depends on the number of carbon atoms in the supercell. With the third order IFCs, we solved the phonon BTE with iterative method with ShengBTE code developed by Li et alκ. The grid convergence in k-space of all cases were examinedκ reported here was the converged value . In details for ShengBTE calculations of SWCNTs and graphene, the interactive length we took is 3.4 Å which is the van der Waals force radius of carbon atoms. For the SWCNTs with diameter longer than 3.4 Å, we used the cross-sectional areaS = πdh, where d is the diameter of SWCNT and h = 3.4 Å. In ultra-thin SWCNTs which their diameters shorter than 3.4 Å, the cross-sectional area we used was For the calculation of How to cite this article: Yue, S.-Y. et al. Diameter Dependence of Lattice Thermal Conductivity of Single-Walled Carbon Nanotubes: Study from Ab Initio. Sci. Rep. 5, 15440; doi: 10.1038/srep15440 (2015).