NTR, signaling molecules, NMDA receptor—NR1 subunit as well as proBDNF and BDNF. Prenatal cocaine exposure reduces activity-dependent proBDNF and BDNF release and elevates BDNF affinity for TrkB leading to increased tyrosine-phosphorylated TrkB, heightened Phospholipase C-γ1 and N-Shc/Shc recruitment and higher downstream PI3K and ERK activation in response to ex vivo BDNF. The augmented BDNF-TrkB signaling is accompanied by increases in association between activated TrkB and NMDARs. These data suggest that cocaine exposure during gestation upregulates BDNF-TrkB signaling and its interaction with NMDARs by increasing BDNF affinity, perhaps in an attempt to restore the diminished excitatory neurotransmission.Prenatal cocaine exposure causes profound changes in neurobehavior as well as synaptic function and structure with compromised glutamatergic transmission. Since synaptic health and glutamatergic activity are tightly regulated by brain-derived neurotrophic factor (BDNF) signaling through its cognate tyrosine receptor kinase B (TrkB), we hypothesized that prenatal cocaine exposure alters BDNF-TrkB signaling during brain development. Here we show prenatal cocaine exposure enhances BDNF-TrkB signaling in hippocampus and prefrontal cortex (PFCX) of 21-day-old rats without affecting the expression levels of TrkB, P75 In the prenatal cocaine exposed group, BDNF-induced pY-145-KDa TrkB was 222%  and 196%  of that of the saline-exposed group in the hippocampus and PFCX, respectively . In cont473Akt1 (55%  and 73%  in hippocampus and PFCX, respectively; 202/pY204-ERK2 (59%  and 59% [t]7) = 6.8395, P = 0.00025] in hippocampus and PFCX, respectively; The finding of a higher BDNF-induced pY-145-KDa TrkB in prenatal cocaine exposed brains was substantiated by higher levels of BDNF-induced recruitment of phospholipase C-γ1 (173%  and 86%  increase in hippocampus and PFCX, respectively) and adaptor proteins Shc (70%  and 50%  increase in hippocampus and PFCX, respectively) and N-Shc (91%  and 42%  increase in hippocampus and PFCX, respectively) to specific pY-TrkB docking sites . AdditioBDNF-TrkB activation can regulate long-term synaptic plasticity by interacting with NMDARs. To assess whether gestational cocaine exposure affects the inter-relationship between activated TrkB and NMDARs, we measured the levels of the obligatory NMDAR subunit, NR1, that co-immunoprecipitated with TrkB with or without BDNF incubation. Our results show that BDNF stimulation increased the level of TrkB-NMDAR association in brain regions from both prenatal cocaine- and saline-exposed P21 rats as indicated by a marked increase in NR1 in anti-TrkB immunoprecipitates. While there was no discernible difference in TrkB-NMDAR complex level under basal conditions, prenatal cocaine exposure increased BDNF-induced TrkB association with NMDARs by 56%  in the hippocampus and by 49%  in PFCX above that of the saline-treated group .Collectively, these data indicate that prenatal cocaine exposure heightens the efficacy of BDNF-TrkB signaling and improves the interaction between activated TrkB and NMDAR complexes.Next, we attempted to resolve the underlying mechanism responsible for the heightened BDNF-TrkB signaling Figs –5 and heTo determine whether conformational changes in TrkB in the prenatal cocaine-exposed brains contribute to enhanced BDNF binding affinity for TrkB, we individually isolated TrkB by immunoprecipitation using immobilized anti-TrkB from the hippocampus and PFCX lysates. Following elution, the TrkB-containing eluate was passed through a 100-KDa molecular weight cut-off filter to remove the 95-KDa truncated TrkB. The isoelectric point (pI) of TrkB was determined by separation on isoelectric-focusing gels followed by Western blotting. The results summarized in  indicate+-depolarization and NMDA/glycine. Endogenous BDNF release was evoked by 65 mM K+-depolarization, presumably from the presynaptic axonal terminals or by 10 μM NMDA/1 μM glycine, presumably from the postsynaptic dendritic field in both hippocampus and PFCX  = -3.3142, p = 0.04525 by K+, t(4) = -5.7900, p = 0.01025 by NMDA/glycine; fold increases in proBDNF: t(4) = -3.1394, p = 0.02568 by K+, t(4) = -3.4097, p = 0.02703 by NMDA/glycine] and PFCX fold increases in BDNF: t(4) = -3.5962, p = 0.02284 by K+, t(4) = -6.1707, p = 0.00350 by NMDA/glycine; fold increases in proBDNF: t(4) = -3.4258, p = 0.01404 by K+, t(4) = -2.7508, p = 0.04027 by NMDA/glycine] . Prenatal cocaine exposure decreased proBDNF release by these stimuli by 51–55% in hippocampi  and PFCX   and tissue plasminogen activator (tPA) inhibitors prior to the induction of proBDNF release by Kglycine] .+: t(4) = 0.5769, p = 0.60443, NMDA/glycine: t(4) = 0.6767, p = 0.55359] and PFCX  of prenatal cocaine- vs. saline-exposed rats.In addition, we measured the tPA levels in both brain regions by Western blotting to confirm that the reduction in BDNF and proBDNF release in the prenatal cocaine-exposed brains was not caused by an alteration in tPA levels. The data summarized in  indicateWe show here that prenatal cocaine exposure leads to adaptive hyperactivation of BDNF-TrkB signaling as indicated by heightened activated (pY) 145 KDa TrkB and increased NMDAR interaction with TrkB. These BDNF-induced TrkB signaling changes are caused by altered TrkB conformation and increased BDNF binding affinity resulting from dramatically reduced proBDNF and BDNF release at pre- and post-synaptic sites.in utero cocaine exposure.Prenatal cocaine exposure has profound deleterious effects on the function of dopamine D1 , 27–29, ex vivo BDNF incubation of prenatal cocaine-exposed brains elevates both TrkB signaling and NMDAR-TrkB association. The increased BDNF-induced TrkB activation in the prenatal cocaine-exposed brains may therefore represent a neuroprotective adaptation in response to dampened NMDAR activity [ex vivo BDNF-induced TrkB activation and signaling were observed in postmortem Alzheimer’s disease brains in which NMDAR function is severely compromised [202/pY204-ERK) and Akt (pS473-Akt) through the binding of adaptor proteins such as Shc and N-Shc to phosphotyrosine residues on activated TrkB [ex vivo BDNF incubation were higher in brains of prenatal cocaine-exposed P21 rats. While our data also show that ex vivo BDNF promotes tyrosine phosphorylation of the truncated form (95-KDa) of TrkB in both brain regions of P21 rats, prenatal cocaine has little effect on pY 95-KDa TrkB levels. The functional significance of the pY 95-KDa is however currently unknown.BDNF-TrkB signaling is essential for the tangential and radial neuronal migration in embryonic forebrain  and estaactivity . Similarpromised , 50. BDNted TrkB . AccordiNTR [NTR and the efficacies of TrkB/p75NTR signaling in different brain regions. However, the BDNF concentration (50 ng/ml) used in the current ex vivo condition does not affect p75NTR (NTR function as demonstrated by the reduction in the p75NTR and TRAF2/6 association in response to 200 ng/ml BDNF and proBDNF (data not shown). Since prenatal cocaine exposure did not result in discernible changes in TRAF2/6 and p75NTR, more thorough investigations are needed to elucidate the underlying mechanisms responsible for the reduced coupling of TRAF2/6 with p75NTR in the prenatal cocaine exposed brains. Because the majority of full-length TrkBs in prenatal cocaine-exposed brains under non-stimulated conditions exhibited a higher pI, an altered TrkB conformation may underlie the observed higher affinity of BDNF for TrkB [NTR system.Changes in BDNF-TrkB signaling during critical developmental stages greatly influence synaptic formation, brain architecture and function later in life . Hence, NTR . The thrt p75NTR  and our for TrkB . Alterna+-depolarization and NMDA/glycine increased BDNF-TrkB signaling by promoting BDNF release, presumably from respective presynaptic neuronal terminals and postsynaptic dendritic fields [+-depolarization and NMDA/glycine elicit proBDNF and mBDNF release. More importantly, prenatal cocaine exposure profoundly reduced K+-depolarization and NMDA/glycine-evoked proBDNF and mBDNF release without affecting spontaneous pro-/m-BDNF efflux. Similarly, prenatal cocaine exposure reduces K+-induced BDNF release in hippocampus, cortex and striatum determined 1-week postnatally [To delineate the origin of TrkB conformational change and heightened BDNF binding affinity in prenatal cocaine-exposed brains, we determined the levels of activity-dependent BDNF and proBDNF release since overall proBDNF and BDNF expression was not altered. Prenatal cocaine exposure transiently reduces BDNF levels in embryonic forebrains early in gestation, which fully recover at later embryonic stages . In our c fields . We showtnatally . Thus, aProBDNF may be converted into mBDNF intracellularly in the trans-Golgi by subtilisin-kexin of the endoprotease family such as furin, or in the immature secretory granules by proprotein convertases . ProBDNFNTR following prenatal cocaine exposure may suggest that the offspring of pregnant cocaine users are more prone to depression, anxiety and certain cognitive impairments. In support of this depression/anxiety-prone hypothesis, exposure to relatively high doses of cocaine (40 mg/kg/day) and/or nicotine (5 mg/kg/day) in utero promotes depression and anxiety in aging rats [in utero cocaine exposure.BDNF-TrkB signaling is linked to psychological distress and associated cognitive decline . The funing rats . Prenataing rats . Moreoveing rats , 63, deling rats , and imping rats . Hence, ing rats  or be uning rats , 33, 67,ing rats , 33 or ding rats , 33, 67.ing rats , the cur


To compare the proliferation and differentiation of osteoblasts derived from different locations in adolescent idiopathic scoliosis (AIS) patients.From January 2011 to May 2012, a total of 16 AIS patients  were recruited in the study, with age from 11 to 17 years. All patients received posterior spinal fusion and instrumentation, as well as thoracoplasty. Trabecular bone chips from ribs, lamina and iliac crest were harvested in each patient intraoperatively for osteoblast culture. P2 cells were used for the experiment. Proliferation and differentiation of osteoblasts were investigated by using MTT method and alkaline phosphatase (ALP) activity, respectively. One-way analysis of variance (ANOVA) was used for comparison of proliferation and differentiation among osteoblasts derived from different locations.For MTT assay, the proliferation of lamina osteoblast  was slightly lower, whereas the proliferation of rib osteoblast  was slightly higher, than that of ilium osteoblast ; however, there was no statistical difference among the 3 types of osteoblasts (P>0.05). ALP activity assay showed that the differentiation of both lamina  and rib  osteoblasts were slightly higher than that of ilium osteoblast , but without statistical significance (P>0.05).There was no difference in the proliferation and differentiation of osteoblasts derived from rib, spinal lamina and iliac crest in patients with AIS. The results of the current study indicate that local and rib bones harvested during surgery may have comparable osteogenic activities to the iliac bone grafts for spinal fusion in AIS patients, potentially eliminating the need for harvesting autologous iliac bone.


Interference of the binding of programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) has become a new inspiring immunotherapy for resisting cancers. To date, the FDA has approved two PD-1 monoclonal antibody drugs against cancer as well as a monoclonal antibody for PD-L1. More PD-1 and PD-L1 monoclonal antibody drugs are on their way in clinical trials. In this review, we focused on the mechanism of the PD-1/PD-L1 signaling pathway and the monoclonal antibodies (mAbs) against PD-1 and PD-L1, which were approved by the FDA or are still in clinical trials. And also presented is the prospect of the PD-1/PD-L1 immune checkpoint blockade in the next generation of immunotherapy. In 2012, 14.1 million new cancer cases were diagnosed worldwide and 8.2 million cancer patients passed away and more than 32.6 million people were living with cancer (within 5 years of diagnosis). About 57% (approximately 8 million) of new arising cancer cases, 65% (approximately 5.3 million) deaths of cancer and 48% (approximately 15.6 million) of the 5-year prevalent cancer cases have taken place in underdeveloped areas . It. It84]. Varied response towards immunotherapy has resulted from the different immune backgrounds of patients. The immune background is dependent on many substances with the immunogenicity a person has in their immune system being determined in the womb. However, the gut microbiota plays a most important role in shaping the systemic immune responses ,86,87. ATo address the immune-related adverse effects of mAbs and get more penetration in solid tumors, some peptides based on immune checkpoint blockers were discovered. A therapeutic peptide targeting PD-1/PD-L1 signal pathway for cancer immunotherapy, AUNP-12 (AUR-12/Aurigene-012) was co-developed by Aurigene Discovery Technologies and Pierre Fabre Laboratories and is currently undegoing preclinical study . The seqOtherwise, there was one patent relating to small drug-like inhibitors. It was filed by Bristol-Myers Squibb in 2015 WO 2015/034820 A1 . The compound and its ramification could inhibit the interactions between PD-1 and PD-L1 having IC50 values between 0.006 and 0.10 mM. It should be noted that Curis, Inc.  announced the FDA has accepted the company’s Investigational New Drug (IND) application for CA-170 at 1 June 2016. CA-170 is the first orally available small molecule targeting and inhibiting the immune checkpoints, PD-L1 and V-domain Immunoglobulin Suppressor of T-cell Activation (VISTA).Science magazine in 2013 reported cancer immunotherapy as the breakthrough of the year [Since the regulatory approval of ipilimumab in 2011, immuno-oncology has not only grown rapidly but also inspired the entire pharmaceutical industry. Dozens of new technologies and investments in immune-oncology have soared overnight, especially since the year . Betweenthe year . Axel Hothe year ,94; and the year ,96,97. GWe expected more PD-1 (or PD-L1) inhibitors to show excellent results at immune checkpoints in reactivating the adaptive or innate immunity for defeating cancers. However, antibody drugs have some insurmountable disadvantages, such as high immunogenicity , high co


GAP-43 is a 25 kDa neuronal intrinsically disordered protein, highly abundant in the neuronal growth cone during development and regeneration. The exact molecular function(s) of GAP-43 remains unclear but it appears to be involved in growth cone guidance and actin cytoskeleton organization. Therefore, GAP-43 seems to play an important role in neurotransmitter vesicle fusion and recycling, long-term potentiation, spatial memory formation and learning. Here we report the nearly complete assignment of recombinant human GAP-43.The online version of this article (doi:10.1007/s12104-015-9660-9) contains supplementary material, which is available to authorized users. GAP-43 is a 25 kDa neuronal intrinsically disordered protein (IDP) highly abundant in the neuronal growth cone during development and regeneration. The exact molecular function(s) of GAP-43 remains unclear but it appears to be involved in growth cone guidance and actin cytoskeleton organization  in minimal medium containing 15N-labeled ammonium chloride and 13C-glucose as sole nitrogen and carbon sources, respectively. GAP-43 expression was induced at an A600nm of 0.6 by addition of 0.8 mM IPTG. The cells were collected after 16 h of expression at 30 °C by centrifugation at 6000 rpm for 10 min and resuspended in 30 ml of ice-cold lysis buffer  per liter of the original bacterial culture. Bacteria were lysed by passing through a French press, and the cell lysate was cleared by centrifugation at 18,000 rpm for 20 min. The supernatant containing the soluble protein fraction was loaded onto a Ni2+ loaded HiTrap 5 ml affinity column , washed with 2 column volumes of high salt buffer  and eluted with high imidazole buffer  using a linear gradient of 15 column volumes. The GAP-43 containing fractions were collected and the buffer was exchanged by dialysis in the measurement buffer, 20 mM NaPi pH 7.4, 50 mM NaCl and subsequently concentrated to 0.5 mM in an Amicon Ultra-15 centrifugal filter device 10 K NMWL (Amicon).The coding region for human GAP-43 was obtained by assembly PCR  processing of higher dimensionality experiments CONCACON . Sampling artefacts from 3D HNCO and 4D HN(CA)NH were removed using cleaner3d  and the assignment transposed to the spectrum of the full-length protein . However, the side chain assignment of the IQ domain for the full-length protein could not be obtained. Consequently, 98 % of backbone 15N, 98 % of 1HN resonance have been assigned and, excluding the IQ domain, 89 % of 13Cα, 85 % of 1Hα, 88 % of 13Cβ, 77 % of 1Hβ and 97 % of 13C′ resonances have been assigned. Additionally, HC(CC-tocsy)CONH spectra allowed the assignment of several side-chain atoms. The neighbor-corrected structural propensity index  under the BMRB accession number 19246.The Supplementary material 1 (DOCX 574 kb)


With the capability of selectively functionalizing graphene, we propose an asymmetric junction between graphene and defective graphene with a high thermal rectification ratio of ∼46%, as demonstrated by our molecular dynamics simulation results. Our findings provide fundamental insights into the physics of thermal transport in defective graphene, and two-dimensional materials in general, which could help on the future design of functional applications such as optothermal and electrothermal devices.Low-dimensional materials such as graphene provide an ideal platform to probe the correlation between thermal transport and lattice defects, which could be engineered at the molecular level. In this work, we perform molecular dynamics simulations and non-contact optothermal Raman measurements to study this correlation. We find that oxygen plasma treatment could reduce the thermal conductivity of graphene significantly even at extremely low defect concentration (∼83% reduction for ∼0.1% defects), which could be attributed mainly to the creation of carbonyl pair defects. Other types of defects such as hydroxyl, epoxy groups and nano-holes demonstrate much weaker effects on the reduction where the  We then explore the possibility to manipulate 2D heat conduction and flow by patterning defects into grapehene by performing MD simulations, and demonstrate a remarkable thermal rectification ratio of ∼46% through a junction between pristine and DG with carbonyl pairs.In this work, we study the thermal conduction in graphene with the presence of a broad spectrum of defects by performing molecular dynamics (MD) simulations. We find that carbonyl pairs and vacancies lead to more significant reduction in the conductivity than hydroxyl, epoxy groups and nano-holes. This conclusion is confirmed by our non-contact opto-thermal Raman measurements, where defects are introduced through oxygen plasma irradiation and a huge reduction of sp2 carbon bonds.Defects could be created in graphene by exotic treatments such as oxygen plasma irradiation or chemical functionalization. Typical defects that have been characterized in oxidized graphene include hydroxyl, epoxy groups, carbonyl pairs, vacancies, as well as nanoholes17181920κDG is related to the thermal conductivity of defects κd, pristine graphene κG, and the areal defect concentration f as:To quantify the concentration dependence, we fit our MD simulation results empirically by using the effective medium theory (EMT)κDG/κG = 1/(1 + rf), we can define a reduction factor r = κG/κd −1 that quantifies the strength of reduction in thermal conductivity, or equivalently an effective size of the defect a = lG − ld = rlG/(r + 1), where lG and ld are the mean free paths by considering the phonon-phonon scattering processes in pristine graphene and defect scattering in DG, respectively. The results summarized in κDG significantly , in stark contrast to the much weaker effects of hydroxyl and epoxy groups that are uniformly distributed in the samples. We also find that once the hydroxyl and epoxy groups clustered into groups, the reduction in κ is almost unchanged. In contrast, the scattering of mono-vacancies is significantly weakened by their coalescence into nano-holes, where scattering occurs at the edges of nanoholes instead of discrete point defects. These results provide an argument that the defects breaking in-plane sp2 bonds are more effective in reducing the thermal conductivity of graphene.By rewriting Thermal conductivity in a solid can in general be expressed in the form of kinetic theory, which is expressed as:c is the specific heat, v, l = vτ, τ are the average phonon group velocity, mean free path, relaxation time, and d is the dimension of problem. The scattering sources arising from defects in graphene include mass difference, local strain and boundaries. If we assume that the relaxation times for all these scattering processes are independent, the phonon relaxation or scattering time τ can be calculated by the Matthiessen’s rule τ−1 = Σiτi−1, where the relaxation time τi characterize all scattering mechanisms including the phonon-phonon scattering and defect scatteringsp2 lattice integrity not only introduce stronger scattering centers for propagating phonons, but also reduce the group velocities by softening the latticewhere −1, namely the G peakID/IG, is commonly used to estimate the defect concentrationD/IG increases with the plasma power density (Stage 1), and decreases after a certain point (Stage 2). Here, Stage 1 indicates the structural transition from high quality graphene to defective graphene and Stage 2 refers to the transition from defective graphene to amorphous carbonLD follows the relation of 2930To verify our simulation results, the thermal conductivity of oxygen-plasma-treated graphene was measured by using a non-contact optothermal Raman technique. Oxygen plasma irradiation creates oxygen-containing functional groups and a certain amount of vacancies in graphene1CA ∼4.2 is a parameter given by previous experiment resultsrS ∼1 nm determines the radius of the structurally disordered area, and rA ∼3.1 nm is defined as the radius of the area where the D peak scattering takes placeID/IG of oxygen plasma treated sample is about ∼0.4, ∼1.8, ∼2.3, ∼3.0 and ∼2.2 (Stage 2) when the absorbed laser power is 0.1 mW, corresponding to an average defect distance of ∼17.7, ∼7.5, ∼6.3, ∼5.1 and ∼2 nm  is:In our opto-thermal Raman experiments, the increase in local temperature at the laser spot causes a redshift of Raman peaks 3233, bec32T1 is the temperature at the boundary of suspended graphene, i.e. the part in contact with the gold film, which is assumed to keep at room temperature. Q is the absorbed laser power in total and R = 1.5 μm is the radius of suspended graphene. t = ∼0.34 nm is thickness of graphene, and r is radial position from the laser beam’s center. Ei(x) is exponential integral and r0 = 0.15 μm is the radius of measured laser beam. In this work, the thermal coefficient for G peak of 4.05 ± 0.2 × 10−2 cm−1/K is adopted for the thermal conductivity data fitting3 W/mK at 350 K, which is comparable to previously reported values173 W/mK with the increase of defect concentration. The calculated reduction factor r from experimental results is comparable to the values predicted for lattice vacancy and carbonyl pair by our MD simulations, as shown in where κ much more gently. It should be mentioned that the measured thermal conductivity of graphene could be differed by experimental details, such as the effects of absorptance on graphene, the temperature coefficient of G peak172536r should be a reliable measurement since all graphene samples are measured under same condition and the influence of absorptance and temperature coefficient is minimized via the calculation of κDG/κG.It is interesting to find that in experiments, with the defect concentration of 0.1%, the thermal conductivity of graphene has dropped by ∼83%. While as suggested by our MD simulation results, such a reduction requires for a much higher defect concentration when the defect type being hydroxyl, epoxy groups, as well as nano-holes +  plasma, which is believed to introduce vacancy-like defects in graphene only. Previous work has demonstrated that the intensity ratio between the Raman D and D’ peaks (ID/ID’) can be used to distinguish the nature of defects in graphene, e.g. ID/ID’ is much higher for sp3-like defects (∼13) than vacancy-like defects (∼7) + - and oxygen-plasma-treated graphene, and ID/ID’ for these two samples (∼7.3 and ∼13.0) agree quite well with the above signature. With the increase of absorbed laser power, the ID/IG for Ar+-plasma-treated-graphene dramatically decreases, as shown in D/IG of Ar+- and oxygen-plasma-treated graphene as a function of the absorbed laser power in ID/IG of oxygen-plasma-treated-graphene dropped by ∼25% (from ∼4 to ∼3) only, while that of Ar+-plasma-treated-graphene dropped by ∼75% (from ∼4 to ∼1).In order to verify whether the vacancy-like defects play an important role in thermal conductivity reduction in our experiment, we study the sample treated by Are.g. nanoholes could be formed. Further work is required to elucidate the detailed atomic structures and reconstruction regimes.The above phenomena could be related to the self-repairing of vacancy-like defects. Previous work has shown that the vacancy-like defects tend to self-heal while being annealed in vacuum, which is attributed to the mechanisms of mobile carbon adatoms recombination with vacancies40 + - and oxygen-plasma-treated graphene with the increase in the absorbed laser power are plotted in  + -plasma-treated graphene should be larger than the oxygen-plasma-treated one. However,  + -plasma-treated graphene is ∼0.77 × 103 W/mK, that is higher than the value of oxygen-plasma-treated graphene (∼0.55 × 103 W/mK). Based on the above analysis, vacancy-like defects might not be the major source for the huge thermal conductivity reduction in our oxygen-plasma-treated graphene because of its strong self-repairing effect at high temperature. We suggest that oxygen groups leading to significant modification of the in-plane carbon-bonding network, such as the carbonyl pairs, are the main source of thermal conductivity reduction.The frequency shifts of Are.g. the design of thermal rectification. Thermal rectifier is a two terminal device with a thermal conductance depending on the direction of heat flow, which has broad applications for heat control/management in the futureRth = (κG-DG – κDG-G)/κDG-G could reach 46% at defect concentration f = 1% , we propose a thermal rectifier with high rectification ratio ∼46%, at only 1% defect concentration. Our results could also help on the better understanding of mechanism of thermal conductivity reduction in graphene-based materials, and also provide an efficient way to tune the local thermal conductivity for the future design of graphene based devices, e.g. optothermal, electrothermal devices. +  plasma treatment . The defect concentration can be modulated by fixing the plasma power  and changing the gas pressure .Monolayer graphene was synthesized on a copper foil (25 μm) by means of chemical vapor deposition (CVD) in a vacuum chamber, with a gas mixture of methane and hydrogen  at 1045 °C for 10 minQ on the sample surface leads to the shift in the G peak position, which corresponds to change in the temperature at laser spot.Raman spectra were taken by a Witec alpha 300 R confocal Raman system with an excitation laser of 532 nm (2.33 eV). A 100x objective lens with numerical aperture of 0.9 is used, and the spot size of the laser is estimated to be ∼300 nm by scanning across a smooth cleaved edge of Au125f is defined as nD/nC where nD is number of the defective atom site and nC is the number of carbon atoms in the pristine graphene lattice. The distribution of defects in DG is sampled randomly.The molecular structure of DG consists of hydroxyl, epoxy, and carbonyl groups on the basal plane, as well as defective sites and open edges2 supercell of graphene and DG, which are verified to capture the thermal conduction in G and DG structures57Classical MD simulations are performed using the large-scale atomic/molecular massively parallel simulator (LAMMPS)535455κ of pristine and defective graphene from MD simulations, we use the Green-Kubo method based on the linear response theoryκ could thus be expressed as an integration of the heat flux operator multiplied by a prefactorTo compute the thermal conductivity T is the temperature of system, kB is the Boltzmann constant, and V is the system volume that is defined here as the area of graphene or DG multiplied by a nominal thickness . The upper limit of time integration τc needs to be long enough so the current-current correlation function decays to zero, Jx and Jy are the heat current operators in the x and y directions, and the angular bracket represents the ensemble average, namely the heat flux autocorrelation function (HFACF). The heat flux J of the system is computed from the expression J = (Σieivi – ΣiSivi)/V, where ei, vi and Si are the total energy, velocity vector, and stress tensor of each atom i, respectively. We first integrate HFACF with an integration time τ following κ and τ. The decorrelation time for the heat flux is typically on the scale 100 ps for our models, and thus converged results for κ could be extracted when τ > τc in the simulations. The advantage of Green-Kubo method, compared to the non-equilibrium molecular dynamics (NEMD) simulations with thermal gradient built up across the material that is used in our investigation on the non-equilibrium processes, is that it does not need to perturb the simulated system out of equilibrium, where nonlinearity arises60κ as the mean value of κxx and κyy that may differ in the finite system under simulation though, where the maximum difference between κxx and κyy in our simulations is less than 0.1κ.where T = 350 K, where the quantum nuclear effect is weak) under a Nosé-Hoover thermostat for 200 ps, in which the time step is 0.1 fs. The stress is released by coupling with a barostat. The structure is further equilibrated in a NVE ensemble for 50 ps before the thermal conductivity is calculated. In the equilibrium Green-Kubo calculations, the system is simulated in a microcanonical ensemble as well. The atomic positions and velocities are collected during the simulations to evaluate the heat flux and its autocorrelation functions. The thermal conductivity is finally obtained by following the Green-Kubo formula. The results are calculated by averaging over five different runs for the same DG sample at a certain defect concentration.In the MD simulations, the atomic structures of graphene or DG are firstly equilibrated at the same temperature as the experimental condition .


Posttraumatic Stress Disorder (PTSD) is a prevalent, chronic, and disabling anxiety disorder that may develop following exposure to a traumatic event. The majority of individuals with PTSD often have comorbid psychiatric conditions such as major depression, generalized anxiety disorder, and substance use disorders, and are at increased risk for suicide. Despite the public health significance of PTSD, relatively little is known about the etiology or pathophysiology of this disorder, and pharmacotherapy development to date has been largely opportunistic instead of mechanism-based. One promising target for modulation is Tropomyosin Receptor Kinase B (TrkB), the receptor for Brain-Derived Neurotrophic Factor (BDNF), a signaling pathway important for neuronal plasticity, survival, and growth. The following discusses how genetic and environmental alterations to this signaling pathway may contribute to anatomical and functional changes in the hippocampus, amygdala, anterior cingulate cortex, ventromedial prefrontal cortex, and the nucleus accumbens. Changes in these brain regions may in turn contribute to the predisposition to or maintenance of some of the clinical manifestations of PTSD, including intrusive memories, hyperarousal, increased fear, and emotional numbing. Post-Traumatic Stress Disorder (PTSD) is a disease which affects millions of people a year, yet no strong, universal prevention or treatment strategy is available. One promising target for the development of trsategies of treatment and secondary prevention is tropomyosin receptor kinase B (TrkB), the receptor for brain-derived neurotrophic factor (BDNF). This signaling pathway has been implicated in a wide variety of psychiatric diseases, with significant changes in levels of BDNF and TrkB mRNA and protein levels in the hippocampal and pre-frontal cortical regions in the post-mortem brains of individuals with various psychiatric diseases –4. More Searches were carried out using primarily Google Scholar and NCBI’s PubMed databases. Key search terms used, some in combination, include: “PTSD,” “BDNF,” “TrkB” “neurogenesis,” “stress,” “corticosterone,” “post-mortem,” “depression,” “hippocampus,” “nucleus accumbens,” “prefrontal cortex,” “anterior cingulate cortex,” “amygdala,” “fMRI,” “volume,” “heterozygous,” “child,” “Val66Met,” “5-HTTLPR,” “fear,” “contextual fear,” and “reward responsiveness.” Additional literature was found using review papers to fill in any gaps generated from the above search criteria. The paper itself attempts to describe the strength and quality of evidence found in any given paper, for example, whether it is cross-sectional, genetic, meta-analytic, prospective, or experimental, and whether it was done in humans or animal models. An effort is made to include all literature directly relevant to the arguments made herein, with a special focus on the highest-quality evidence.The effects of BDNF-TrkB signaling are wide ranging and include increased cell plasticity, survival, and growth. TrkB signals through Ras, PI3K, and PLC-gamma and is important for long-term potentiation in the hippocampus ,9, hippoTo understand how PTSD develops, it must be explained how genetic and environmental variables lead to predisposing neurocircuitry abnormalities, which when confronted with a traumatic stimulus, induce or uncover other abnormalities, resulting in sustained PTSD symptoms. Using various prospective, twin, and genetic studies, there has been some recent work that attempts to differentiate which abnormalities present in individuals with PTSD pre-date the traumatic experience from those acquired during and after the trauma . BuildinCross-sectional studies have associated decreased hippocampal volume, especially in the cornu ammonis region 3 and the dentate gyrus of the hippocampus, with PTSD ,21. StroWhile childhood neglect and maltreatment clearly pre-dispose individuals towards increased amygdala reactivity, it is more uncertain whether these factors contribute to decreased hippocampal volume. Some have found decreased hippocampal volume among those maltreated as children , while oIn addition to potential stress induced changes in BDNF-TrkB signaling and hippocampal volume, genetic variation in this pathway probably also contributes to some PTSD vulnerability with respect to hippocampal volume. The BDNF Met allele is associated with declarative memory deficits, decreased hippocampal NAA levels , and decGiven the importance of both of these structures in bringing about the fear response, and in the case of the dACC inhibiting fear extinction, increased responsivity to emotional stimuli in these areas may account for some of the increased fear expression, hyperarousal and to a lesser extent intrusive memories seen in PTSD ,58–60. IChanges in the function of the amygdala have been associated with childhood maltreatment, deprivation, and institutionalization ,67–70 anNonetheless, it should be noted that increased BDNF signaling could theoretically increase the risk of PTSD, if present in certain brain areas such as the amygdala. During fear acquisition BDNF expression and TrkB phosphorylation are increased in the basolateral amygdala, while inhibition of TrkB in the BLA resulted in disrupted fear acquisition . All togAnother major brain area important in PTSD is the ventromedial prefrontal cortex, an area involved in fear extinction . In the Another brain region implicated in the pathogenesis of PTSD is the nucleus accumbens area. Evidence indicates that in PTSD the nucleus accumbens may be less active, corresponding to a decrease in reward responsiveness ,90. HoweChanges in peripheral concentrations of BDNF have been found in a diverse set of psychiatric diseases, including schizophrenia, depression, bipolar disorder –95. PeriOverall, there is moderately strong evidence to suggest that increased peripheral BDNF is associated with a current diagnosis of PTSD. One study found increased BDNF serum concentrations among those with PTSD, but only in the PTSD group whose traumatic experienced occurred in the past year . AnotherAlthough there is evidence that suggests an elevation in peripheral BDNF after developing PTSD, it is unclear how this is related to the pathogenesis of the disease. For instance, it may be a compensatory response, rather than a predisposing one. More prospective studies need to be carried out to determine how peripheral BDNF levels are related to the neurocircuitry models discussed in the other sections of this paper.Overall, it appears that alterations in BDNF-TrkB signaling may play an important role in PTSD. In the hippocampus, vmPFC, ACC, and NAcc deficient BDNF-TrkB signaling likely aids in the pre-disposition to maintenance of impaired contextual fear learning, fear extinction, and restricted range of affect. In turn, these may be associated with some of the clinical manifestations of PTSD, such as intrusive and incomplete memories, hyperarousal, fear expression, and restricted range of affect.Although a decrease in signaling in the BDNF-TrkB pathway is likely a contributing factor in PTSD, as a neurotrophin and regulator of plasticity, changes in either direction in BDNF signaling, depending on its location, intensity, and time course may moderate the risk of developing stress related psychopathology. In animal models, systemic administration of TrkB receptor modulators have resulted in changes in phenotypes related to human PTSD, such as fear acquisition and extinction  and anxi


The response of graphene surface plasmon (SP) in the ultraviolet (UV) region and the realization of short-wavelength semiconductor lasers not only are two hot research areas of great academic and practical significance, but also are two important issues lacked of good understanding. In this work, a hybrid Fabry-Perot (F-P) microcavity, comprising of monolayer graphene covered ZnO microbelt, was constructed to investigate the fundamental physics of graphene SP and the functional extension of ZnO UV lasing. Through the coupling between graphene SP modes and conventional optical microcavity modes of ZnO, improved F-P lasing performance was realized, including the lowered lasing threshold, the improved lasing quality and the remarkably enhanced lasing intensity. The underlying mechanism of the improved lasing performance was proposed based on theoretical simulation and experimental characterization. The results are helpful to design new types of optic and photoelectronic devices based on SP coupling in graphene/semiconductor hybrid structures. In recent years, short-wavelength semiconductor lasers have drawn much attention due to their unique properties and wide applications in optoelectronic devices1357910121617192021et al. have demonstrated that graphene has about 2.3% absorption in visible region but an abnormal absorption in the UV region due to its unique electronic structure and the Dirac-fermionic energy dispersion25π → π* transition would response to the excitation in low-energy UV region according to the theoretical research by Eberlein and Trevisanutto et al28et al. further revealed graphene-induced strong light-matter interaction and the corresponding optical field confinementet al. reported an enhancement of the random lasing action in a nanocomposite of reduced graphene oxide nanoflakes and ZnO nanorodsGraphene, a flat monolayer of carbon atoms tightly packed into a honeycomb lattice, has attracted much attention ever since its discovery in 2004 due to its remarkable properties and potential applications232425In this work, to provide sufficient evidence of graphene SP's response in UV region and extend its functionality, a hybrid F-P microcavity consisted of monolayer graphene covered ZnO microbelt was designed and fabricated. ZnO microbelt with rectangular cross-section can be treated as an intrinsic F-P type microresonators, whilst as the gain medium. Graphene covered on the surface of the microbelt acted as the external modulation. Graphene SP excited along the interface of graphene/ZnO could modulate the local field, which can compensate the optical loss and make the radiative photons be better imprisoned within the F-P microresonators. Through the coupling between graphene SP modes and conventional optical microcavity modes, obviously improved F-P lasing performance was achieved. The interaction mechanism was investigated through theoretical simulation and experimental characterization. The results are helpful not only to understand the interaction between graphene and semiconductor under the optical excitation in physics but also to inspire novel design of graphene-based optic and photoelectronic devices in technology.ZnO microbelts were synthesized by a vapor phase transport (VPT) method and x-y plane (i.e. the cross-section) of the bare ZnO microcavity. In By using a finite difference time domain (FDTD) method, the optical field distribution and the mode structure in the bare and the hybrid microcavity were simulated. As aforementioned, in order to improve the performance of conventional optical microcavities, a kind of hybrid plasmonic microcavity system was proposed to achieve the coupling of SP modes with conventional optical cavity modes343637Experimentally, in order to investigate the influence of graphene on the optical behaviors of the ZnO microbelt, a hybrid microstructure was fabricated by partially covering ZnO microbelt with monolayer graphene. 2(high) modes of wurtzite ZnO at 437 cm−1, but also the sharp and intensive 2D peak and G peak of graphene. The strong E2 mode demonstrates the good crystal quality of the ZnO microbelt. The sharp 2D peak and G peak of graphene present single-Lorentzian curves with FWHM of 31 cm−1 and 14 cm−1, respectively, and the intensity ratio of 2D mode to G mode (I2D/IG) is ~2.2, indicating the high quality of the monolayer graphene. Based on these characteristics, we can believe that the monolayer graphene was successfully covered on the ZnO microrbelt and the graphene/ZnO hybrid microcavity was fabricated. Two spots labelled as spot 1 (without graphene covering) and spot 2 (with graphene covering) were selected to compare the optical behaviors of ZnO with/without graphene. To assess the coverage state of graphene on the ZnO microbelt, Raman spectrum from the graphene covered ZnO microbelt was measured, as shown in Besides the enhanced PL intensity, an interesting phenomenon, i.e. the optical field confinement induced by graphene covering was also observed distinctly. As shown in 2, the PL spectrum presents a broad spontaneous emission, which comes from the near band-edge (NBE) emission of ZnO2, some distinct and sharp peaks emerged in the spectrum, indicating the lasing generation from the bare ZnO microbelt. So we can deduce that the threshold for the bare microbelt is about 120 KW/cm2. The sharp peaks demonstrated distinctly the mode structure of the stimulated emission, while the broad and strong background indicates the optical loss and poor lasing quality, consistent with the simulation results demonstrated in λ = (λ2/[2L(n−λdn/dλ)]dn/dλ = −0.026 nm−1 at λ = 390.2 nm denotes the dispersion relation for the refractive index, Δλ = 0.2 nm as indicated by the PL spectrum, the calculated cavity length L = 30 μm, which agrees well with the experimental value measured by SEM. This indicates that the observed stimulated emission belong to the F-P lasing mechanism, which is formed in the cavity at the width direction of the cross-section of the microbelt. Actually, this F-P lasing mechanism also can be confirmed througth the dark field optical images of the bare ZnO microbelt and the hybrid microcavity. As shown in PL spectra from the bare and the hybrid microcavity were measured to investigate the impact of graphene SP on the lasing behaviors of the ZnO microbelt, as shown in 2, distinct lasing peaks have appeared in the spectrum, indicating a lower threshold of spot 2 than that of spot 1. This can be attributed to the graphene SP's confinement of the optical field and its coupling with ZnO interband emission, as has been reported by our previous reportAs the microbelt was covered with graphene, the PL spectra from spot 2 changed dramatically, as shown in 2, the slope increased sharply and some distinct and sharp peaks appeared in the spectrum as shown in 2. The slow increase of the lasing intensity with increase of the excitation power density was caused by the optical loss of the bare microcavity, as shown in 2, the mode structure is clearer and the intensity of the emission is much higher than that of the bare microcavity at the same excitation condition. From this we can conclude that the threshold of the hybrid microcavity is 110 KW/cm2, which is lower than that of the bare one. It should be noted that the lasing emission intensity of the hybrid microcavtiy increase more quickly than that of the bare one, indicating the more efficient output of the microcavity due to the optical field confinement induced by graphene SP and its effective coupling with ZnO.2 is shown in A clearer comparison of the lasing behaviors of the two spots under the same excitation of 140 KW/cmIn summary, a hybrid plasmonic F-P microcavity was constructed and fabricated by covering monolayer graphene on the ZnO microbelt, and unambiguously improved F-P lasing performance was realized, including the lowered lasing threshold, the improved lasing quality and the significantly enhanced lasing intensity. Theoretical simulation indicated that the graphene SP wave was excited along the interface of graphene/ZnO and the crossover region provide a platform to realize the coupling interaction between graphene SP modes and the ZnO F-P modes. On the other hand, the coupling interaction can play a modulation of the oscillation and energy storage of the ZnO F-P microcavity. The results presented here would be valuable for both understanding the interaction between graphene and semiconductor under the optical excitation in physics and motivating new ideas for designing of graphene-based optic and photoelectronic devices in technology.ZnO microbelts were synthesized by a VPT methodC.X. Xu conceived and designed the experiments. J.T. Li and Y. Lin carried out the optically pumped experiments. Y.Y. Wang and J.F. Lu optimized the growth conditions for the ZnO microbelts and the CVD-grown graphene. M.M. Jiang carried out the simulations and theoretical analysis. Z.L. Shi gave scientific advice. J.T. Li and C.X. Xu wrote the paper and all authors commented on the manuscript at all stages.


Through molecular mechanics we find that non-covalent interactions modify the fractality of crumpled damaged graphene. Pristine graphene membranes are damaged by adding random vacancies and carbon-hydrogen bonds. Crumpled membranes exhibit a fractal dimension of 2.71 ± 0.02 when all interactions between carbon atoms are considered, and 2.30 ± 0.05 when non-covalent interactions are suppressed. The transition between these two values, obtained by switching on/off the non-covalent interactions of equilibrium configurations, is shown to be reversible and independent on thermalisation. In order to explain this transition, we propose a theoretical model that is compatible with our numerical findings. Finally, we also compare damaged graphene membranes with other crumpled structures, as for instance polymerised membranes and paper sheets, that share similar scaling properties. Graphene is a one-atom thick membrane possessing extraordinary mechanical and electronic properties12Through sophisticated molecular mechanics simulations we show here that, for sufficient degree of damage, graphene sheets become fractal with a dimension that depends on the interaction range of the potential. Non-covalent interactions (NCIs) like van der Waals forces play such a dominant role, that they not only densify the molecular structure but even enhance the fractal dimension of DGM by over 20%.We simulate DGMs using molecular mechanics with the adaptive intermolecular reactive bond-order (AIREBO) potential3 carbon atoms, where ab initio simulations are computationally too expensive.where L = 60 Å. The exact value of the initial bond length is irrelevant, since the potential dynamically changes it, and finally adjusts it to the equilibrium length. To introduce disorder, we create vacancies by randomly removing carbon atoms, obtaining vacancy concentrations ranging from p = 0 to the critical percolation point pc = 0.303 for hexagonal lattices, which is the highest possible vacancy concentration that can be achieved for our purpose, because only small clusters remain for higher values of p. After damaging the graphene membranes with vacancies, we extract the largest connected cluster. Note that there is experimental evidence showing that if similar graphene clusters (or flakes) have a certain size, then fullerenes cages can be formedz-direction (randomly up or down in order to avoid a preferred crumpling direction). For carbon atoms with one single carbon neighbour, we add two hydrogen atoms, one in positive and one in negative z-direction. Note that adding hydrogen atoms is crucial for the stability of the DGM. If we do not add hydrogen atoms to avoid the passivation of the dangling bonds, then we can only simulate vacancy concentrations up to 10%. For higher vacancy probabilities, the graphene sheet cannot recover and gets more akin to amorphous carbon. Thus, the presence of hydrogen atoms inhibit the saturation of benzene rings in the disordered hexagonal lattice, allowing to keep sp2 hybridisation and the conjugated bonds. By applying this procedure, we obtain for p = 0 a graphene sheet where the open edges with dangling σ-orbitals are terminated by carbon-hydrogen bonds. The densities of these DGMs exhibit a power-law dependence on p.The initial building block for our DGM is a quadratic graphene membrane  with an initial bond length of 1.4 Å (which is close to the equilibrium bond length of graphene) and an edge length of p. We set the time step for the molecular mechanics simulation to 0.1 fs, which is sufficiently small to capture the carbon-carbon and the carbon-hydrogen interaction properly. In order to fix the temperature, we apply a Nosé-Hoover thermostat obtaining the equilibrium state of the DGM in the canonical ensemble (NVT). Each simulation begins with a flat DGM located in the x − y plane at a temperature of 800 K which corresponds to an optimal value that is low enough to keep covalent bonds, provides enough kinetic energy to explore the phase space, and speeds up the equilibration process. , and shift the origin of the coordinate system to the center of mass frame. The gyration tensor is then obtained byThe obtained DGM structures are characterized in terms of the gyration tensor and the fractal dimension. We first compute the center of mass, i.e. m, n ∈ {1, 2, 3}. This matrix is symmetric and, therefore, its eigenvalues λn are real and their associated eigenvectors orthogonal to each other. The eigenvalues λn correspond to the extensions in the direction of their eigenvectors. The sum of the eigenvalues gives the square of the radius of gyration, Rg is an appropriate measure to quantify the compactness of various structures, like for instance organic moleculesRg should relate with the mass M of the total DGM as a power law,where MM(r) is the mass of the atoms contained in a sphere of radius r and origin at the closest atom to the center of mass (See M(r) in discrete exponential intervals, rk = 1.05k, where dF for each single DGM.To obtain the fractal dimension we use the sand-box method through the relation mass See . We compRg for different temperatures and vacancy densities p. We observe that Rg is strongly dependent on temperature and can vary as much as 30% for high values of p. This is in agreement with the fact that thermal fluctuations act stronger on the out-of-plane bending modes than on the in-plane stretching modesRg, and find, by considering different system sizes, that DGMs display self-similarity for all vacancy densities p , the DGM has only a few local vacancies and hydrogen atoms. The fractal dimension of both simulations (with and without NCIs) is dF ≈ 2  do not change significantly in this region. Surprisingly, the simulations without NCI reveal a much smaller fractal dimension, dF = 2.30 ± 0.05, showing that the NCI play a crucial role in compressing the DGMs. In principle, our simulation allows for the creation of new covalent bonds during the crumpling process. However, as shown in the In contrast to region I, we observe that in region III the DGM extends in all three principal axes  become visible  and for high values of p we have the crumpled phase.For low vacancy densities ture see . TherefoNote that from dF = 2.35 ± 0.05, which is in agreement with our results. The crumpling driven by mechanically compressing an isotropic elastic shell that contains a graphene membrane led to the same fractal dimension within error barsInterestingly, fractal dimensions comparable to our findings have been observed experimentally for dry and fresh cream layers, 2.65 ± 0.10 and 2.45 ± 0.15, respectively1315US = AR2 USA = Bρ2V leads to a mass-size scaling M ∝ R2.5, which is consistent with our results for DGM in absence of NCIs. NCIs expressed through a modified Lennard-Jones potential influence the repulsive energy USA leading to a term R, the mass-size relation M ∝ R2.75 follows straightforwardly, which is consistent with our results , the DGM is only extended in two principal axes and dF ≈ 2; in region II (0.1 < p < 0.22), a system size dependent transition occurs from a flat to a crumpled object ; and in region III (p > 0.22), we observe essentially an isotropic and crumpled DGM. The crumpled graphene sheets are self-similar, with a fractal dimension of 2.71 ± 0.02 and 2.30 ± 0.05 for simulations with and without NCIs, respectively. From this last result, we deduce that the NCIs play a crucial role in the crumpling process during compression of DGMs. Finally, we also provide a phenomenological model that describes qualitatively our numerical findings.In summary, we have studied the crumpling transition of DGMs obtained by introducing random vacancies and hydrogen atoms to a graphene sheet. We have shown that there is a clear transition from a flat membrane towards a crumpled DGM by increasing the fraction How to cite this article: Giordanelli, I. et al. Crumpling Damaged Graphene. Sci. Rep.6, 25891; doi: 10.1038/srep25891 (2016).


Multiple-choice questions (MCQ) are still widely used in high stakes medical exams. We wanted to examine whether and to what extent a national licensing exam uses the concept of pattern recognition to test applied clinical knowledge.We categorized all 4,134 German National medical licensing exam questions between October 2006 and October 2012 by discipline, year, and type. We analyzed questions from the four largest disciplines: internal medicine (n = 931), neurology (n = 305), pediatrics (n = 281), and surgery (n = 233), with respect to the following question types: knowledge questions (KQ), pattern recognition questions (PRQ), inverse PRQ (IPRQ), and pseudo PRQ (PPRQ).A total 51.1% of all questions were of a higher taxonomical order (PRQ and IPRQ) with a significant decrease in the percentage of these questions (p <0.001) from 2006 (61.5%) to 2012 (41.6%). The proportion of PRQs and IPRQs was significantly lower (p <0.001) in internal medicine and surgery, compared to neurology and pediatrics. PRQs were mostly used in questions about diagnoses (71.7%). A significantly higher (p <0.05) percentage of PR/therapy questions was found for internal medicine compared with neurology and pediatrics.The concept of pattern recognition is used with different priorities and to various extents by the different disciplines in a high stakes exam to test applied clinical knowledge. Being aware of this concept may aid in the design and balance of MCQs in an exam with respect to testing clinical reasoning as a desired skill at the threshold of postgraduate medical education. Multiple-choice questions (MCQs) are still used in high stakes exams worldwide to assess the knowledge of medical students. Even though alternative assessment formats are available and increasingly applied, such as modified essay questions (MEQs) or objective structured clinical exams (OSCEs), the ease of use and testing efficiency of these formats are tempting features for the continued and widespread application of MCQs. In the USA and Germany, for example, MCQs constitute a major part of the National Medical Licensing Exam. While MCQs were originally designed to assess factual knowledge, well-constructed MCQs can also assess the application of knowledge, resembling a taxonomically higher order than the simple recall of isolated facts . AnsweriClinical reasoning used by physicians in daily practice presents itself as a combination of two different approaches: diagnostic pattern recognition (PR) and analytical hypothesis-based thinking . The abiEven though PR is, by definition, a personal and idiosyncratic process and might not be explicitly taught as clinical reasoning in every medical school, we hypothesize that it is an ideal concept to test applied medical knowledge in high stakes exams. To test whether and to what extent PR is used in MCQs, we defined a framework for the detection of disease patterns clinically used for PR. Based on this framework we analyzed all MCQs from the German National Licensing Exams, Part 2, between October 2006 and October 2012 in the disciplines of internal medicine, surgery, neurology, and pediatrics.Since October 2006, every German National Medical Licensing Exam, Part 2, has consisted of 320 MCQs and an additional oral-practical exam lasting two hours per student. The exam takes place at the end of the final year of a six-year medical undergraduate curriculum and is held twice a year, in April and October. The actual final number of valid questions per exam is often below 320, because invalid MCQs are excluded after the exam has taken place. All MCQs have five possible answers and include questions with either a single correct or a single incorrect answer. In addition, long patient cases with six to 17 questions related to the same case are presented, with a single correct answer per question. Extended-matching MCQs are not included in this exam.MCQs for the German National Medical Licensing Exam, Part 2, are developed by a national institute . Panelists, recruited from the different specialist medical societies develop and revise the questions with respect to their scientific and clinical content. In a second step, IMPP employees check the questions with respect to formal correctness, comprehensibility, and difficulty. In a third step, referees in different panels solve the anonymized questions and discuss and revise them afterwards, if necessary, with respect to content and structure. The vote to actually use a certain question in an exam has to be unanimous.We screened a total of 4,134 questions from the German National Medical Licensing Exam, Part 2 (October 2006 until October 2012), and assigned each question to one of 23 medical disciplines based on its topic and the correct answer. Questions from the four largest disciplines , which constituted more than 42% of all questions, were included in this study. Questions from other disciplines, such as ophthalmology, were excluded from our analysis, because their numbers per discipline were too small for statistical analysis. In certain years, some disciplines were not even included in the exam. Questions were assigned to the pediatric discipline when the age of the described patient was below 18 years. When an overlap between internal medicine and surgery was detected, questions were assigned to the surgery discipline when surgical procedures were the correct treatment. This resulted in 1,750 questions, which were included in our analysis .We defined four categories of questions for our analysis: PR questions (PRQ), pseudo PR questions (PPRQ), inverse PR questions (IPRQ), and knowledge questions (KQ). An example of every type of question is given in Table Each question was assessed and categorized by two of four physician panelists. When disagreement in categorizing occurred, the question was discussed with one of the other two panelists and categorized according to the best fitting category according to the descriptions mentioned above.χ2-test and significance levels of p <0.05.Data were analyzed using SPSS statistical software (version 21). We assessed differences between the question categories and between the different disciplines with the KQs were identified to constitute the single largest question category (44.3%), while 51.1% of all questions were of a higher taxonomy (PRQ 42.2% and IPRQ 8.9%), and PPRQs occurred in only 4.6%  in internal medicine (40.9%) and surgery (45.1%), when compared with either neurology (74.4%) or pediatrics 65.2%) Figure . The per% Figure Subgroups of the PR questions are displayed in Figure The dual process theory of reasoning includes a fast and intuitive approach and a slow and analytical approach . ExpertsOur study revealed that PR/diagnosis questions occurred in more than 70% of all identified PRQs that used only the first step of the clinical reasoning process  as theirUsing PRQs more frequently in MCQ exams to increase the cognitive level of the questions cannot be concluded from our study without additional considerations. A possible reason why PR/diagnosis questions occur mostly in neurology and pediatrics could be the high availability of disease patterns in these disciplines , 26. ThiA limitation of our study is that it only included the four largest disciplines and excluded 19 smaller disciplines from the original analysis, albeit for statistical reasons. As another limitation, we only studied high stakes exams from one country. However, the framework we suggest for categorizing MCQs can be applied easily in all disciplines and countries and provides an additional concept for quality analysis of MCQ based exams. Furthermore, this framework provides a tool to design MCQs for applied knowledge using pattern recognition as the basis to test diagnostic and therapeutic strategies. It could also be helpful to find the desired balance between MCQs testing factual knowledge and applied knowledge while the amount of MCQs for applied knowledge might be higher in exams at the threshold of postgraduate medical education.Pattern recognition is a prominent concept in MCQs from a National Medical Licensing Exam to test the application of clinical knowledge. Panelists involved in designing questions for high stakes exams should be aware of the PR concept in MCQs, in order to create PRQs with different emphases, depending on the requirements of the individual discipline. Undergraduate medical students should be provided with longitudinal learning opportunities for clinical reasoning, including feedback on their pattern recognition skills in the application of their knowledge. The quality of questions for applied knowledge in MCQ-based exams can be increased by using questions with unambiguous medical patterns to assess the clinical reasoning processes.


Oxaliplatin (OXP) was reported to show low anti-tumor activity when used alone and to display side effects; this low activity was attributed to high partitioning to erythrocytes and low accumulation in tumors. Thermosensitive liposomes (TSL) were considered able to specifically deliver drugs to heated tumors and to resolve the OXP distribution problem. Regretfully, TSL encapsulating doxorubicin did not demonstrate significant improvement in progression-free survival. Drug release below 41°C and significant leakage were considered major reasons for the failure. The purpose of this study was to acquire OXP TSL with rapid release at the triggered temperature and high stability at body temperature and at storage temperatures. A small quantity of poloxamer 188 was introduced into the TSL formulation to stabilize the encapsulated drug. It was shown that the addition of poloxamer 188 had no influence on the TSL characteristics. More than 90% of OXP was released within 10 min at 42°C, and less than 15% was released within 60 min at temperatures below 39°C. TSL were stable at 37°C for 96 h and at 4°C for 6 months. The anti-tumor activity of TSL at the dose of 2.5 mg/kg was certified to be equal to those of OXP injection and non-thermosensitive liposomes (NTSL) at the dose of 5 mg/kg, and significant improvement of tumor inhibition was observed in TSL compared with injection and NTSL at the same dose. It was also shown from the histological transmutation of tumors that TSL had stronger anti-tumor activity. Therefore, it could be concluded that TSL composed of a proper amount of poloxamer had rapid release and high stability, and OXP TSL would be anticipated to exert prominent anti-tumor activity in the clinic. Poloxamer 188 was purchased from Beijing Fengli Jingqiu Commerce and Trade Co., Ltd. OXP was obtained from Jie Rui pharmaceutical company . OXP for injection was purchased from Heng Rui pharmaceutical company . All these reagents were of analytical grade.Lewis Lung Cancer Cell (LLCC) was purchased from the Cell Resource Centre . Male Nu/Nu nude mice (weighing 18–20 g) were purchased from Vital River Laboratories . Mice were all housed in ventilated cages with free access to food and water under standardized conditions . Mice were acclimatized to laboratory condition for one week before the experiment. Meanwhile, a dim red light was used for mice treated during the dark phase. All surgery was carried out under sodium pentobarbital anesthesia and all efforts were made to relieve suffering. All animals were handled in research according to the code of ethics laid down by the Animal Care and Use Ethics Committee of Academy of Military Medical Sciences.OXP TSL were composed of DPPC, MSPC, poloxamer 188 and DSPE-PEG2000 . OXP non-thermosensitive liposomes (NTSL) were composed of HSPC, cholesterol and DSPE-PEG2000 . All liposomes were prepared according to the reported method with some modifications , 23. BriThe morphology of liposomes was observed by transmission electron microscopy (TEM). Liposomes were diluted with distilled water to a certain concentration and dropped on a copper grid to form a dry film at room temperature. Then, liposomes were negatively stained with 2% phosphotungstic acid. The sample was air-dried at room temperature once again and then observed using TEM .Particle size and population distribution of TSL and NTSL were determined by photo cross correlation spectroscopy . The laser intensity was adjusted to 50%-60%, the cross correlation mode was used, and the analysis was operated at 25°C. The measurements were conducted in triplicate. The results were reported as the mean value of 50% particle distribution.The phase transition temperatures of TSL and NTSL were determined with differential scanning calorimeter . The temperature was increased from 30°C to 50°C with a speed of 2°C/min.Encapsulation efficiency (EE) of OXP in liposomes was determined by a modified ultra-filtration centrifugation method . BrieflyThe amount of free OXP in filtrate and the total amount of OXP encapsulated and unencapsulated in liposomes were all determined by HPLC. The separation was performed on a normal phase silica column . The mobile phase consisted of methanol and water  and was pumped at a flow rate of 1.0 mL/min. The detection wavelength was 210 nm, and the injection volume was 20 μL.total indicates the amount of OXP in the whole liposome suspension, and OXPfree indicates the amount of OXP unencapsulated in the liposomes.EE was obtained according to in vitro release curves were plotted with the cumulative percentage of drug released as a function of time (minutes).t represents the measured concentration of OXP in the filtrate at time t, ∑Cm denotes the sum total of the previous concentrations, Vr corresponds to the volume of samples removed for analysis, and dose is the amount of OXP added into the release medium.The drug release studies were carried out at 37°C, 39°C, 41°C and 42°C, respectively. Briefly, 2 mL of liposomes was diluted to 20 mL with 5% glucose solution, stirred and heated at different temperatures. At various time intervals, certain volumes of samples were withdrawn and separated immediately with ultra-filter under centrifugation . The OXP® Expert , an innovative analytical instrument able to determine the small changes of colloidal systems. To obtain these data, the samples were placed into cylindrical glass tubes and then submitted to Turbiscan Lab® Expert at predesigned time points. The stability was evaluated with delta transmission and delta backscattering as indexes [TSL and its 50-fold dilutions with 5% glucose solution and cell culture media (MEM) containing 10% fetal bovine serum (FBS) were kept at 37°C, and parameters of these samples, including particle size, pH and EE, were monitored daily for short-term stability. To evaluate the stability of TSL in the long term, TSL was kept at 4°C, and indexes comprising particle size, pH and EE were examined regularly during a period of 6 months. The stability of TSL and its dilutions was also monitored with a Turbiscan Lab indexes .7 LLCC, and the tumors were allowed to grow until the volume was approximately 200 mm3. The mice were randomly divided into six groups (12 mice per group), and mice in each group were treated every four days by tail vein injection with 5% glucose solution (Control group), OXP solution (5 mg/kg), TSL  and NTSL (5 mg/kg). The injection volume was approximately 200 μL, which was calculated from the weight of mice and the administration dosage. The tumor regions were heated using a homemade hyperthermia device connected with a thermostatic circulator  at 42°C for 30 min after injection. The tumor volume of mice was measured daily and calculated based on t represents the average weight of tumors in each treated group. The excised tumors were fixed in formalin and sliced after paraffin embedding. The slice was stained with hematoxylin and eosin (H&E) for histopathological analysis.The anti-tumor efficacy was evaluated in LLCC tumor-bearing male nude mice. Briefly, the mice were inoculated subcutaneously at the flank region with 200 μL of cell suspension containing 2×10The OXP distribution in plasma and tumors was also evaluated in LLCC tumor-bearing male nude mice. The mice were randomly divided into six groups (3 mice per group), and mice in each two groups were treated every four days by tail vein injection with OXP solution, TSL and NTSL respectively at a dose of 5 mg/kg for 12 days. In one of the two groups given the same formulation, the tumor regions were heated at 42°C for 30 min after injection, and the tumors in the other group were treated without heat. Then, about 1 mL venous blood sample was collected from anesthetized animals in each group, thereafter the mice were sacrificed and the tumors were removed. All blood samples were centrifuged immediately at 4000 rpm for 10 min, and the plasma was obtained by collecting the supernatant. All of the excised tumors were weighed and homogenized. One hundred microliters of 6% (V/V) perchloric acid in water was added into 200 μL of the plasma or the tumor homogenate to precipitate the proteins, and the supernatants for analysis were collected after centrifugation.The content of OXP in supernatants was determined with HPLC. Analysis was performed on a Venusil MP-C18  at room temperature, and the mobile phase contained acetonitrile– 0.1% (V/V) acetic acid in water  and was pumped at a flow rate of 1.0 mL/min. The detection wavelength was 250 nm and the injection volume was 50 μL.p) was less than 0.05.All data were expressed as the mean ± standard deviation (SD) unless specifically outlined. Student’s t-test or one-way analyses of variance (ANOVA) were performed for the statistical evaluation of data. Differences between groups were considered statistically significant when the probability (p>0.05), respectively  [gel of poloxamer in situ gel depends on the concentration and the molecular weight of poloxamers and is commonly no more than 37°C [Poloxamer is an amphipathic nonionic triblock copolymer composed of a central hydrophobic polypropylene oxide chain with two hydrophilic polyethylene oxide  chains , 27. Thigel) . Tgel ofhan 37°C . Poloxamhan 37°C . As abovhan 37°C , 31. ThiUltrafast triggered release of drugs within 20 s  and slowThe most promising liposomal system with desirable efficacy was always characterized by slow leaking and high stability as previous literature reported . Regretf® Expert. The variations of each sample in transmission or backscattering profiles over 4 days were shown in The results of TSL stability at 37°C were shown in The pH, particle size and EE of TSL kept at 4°C were also monitored for 6 months as shown in in vivo precipitation. Poloxamer 188 was also mixed with DPPC as a liposomal membrane component to modify the surface of liposomes and prevent the phagocytosis of TSL by macrophages; however, the incorporation of poloxamer 188 into DPPC liposomes might destabilize the liposomal membrane [Poloxamer has been introduced into several liposomal systems because its moderately concentrated solution is free-flowing at or below normal ambient temperature and is able to transform into gel at body temperature . For examembrane . It has membrane . RegretfThe anti-tumor activities of free OXP, TSL and NTSL were evaluated, and the results were shown in HT has been applied successfully in the clinic to treat solid tumors, and HT combined with chemotherapy is recommended because cancer cells can’t be killed completely because of the gradual decrease in temperature from the center of the tumor to the periphery. A temperature-triggered drug delivery system is the most common combination of HT and chemotherapy. It is reasonable to expect increased accumulation of delivery carriers after localized HT due to elevated blood perfusion and vesicle extravasation, and TSL are considered to achieve the highest accumulation in all delivery carriers because of their rapid intravascular drug release in heated tumors , 31, 37.The body weight and health status of mice were also monitored during the whole treatment period to evaluate the toxicity of different formulations. As shown in The histological transmutation of an excised tumor stained with H&E was shown in In conclusion, TSL showed more powerful anticancer ability than the injection solution and NTSL.To explain the targeting action of TSL combined with HT, the OXP concentrations in plasma and tumors of mice treated with OXP solution, NTSL or TSL combined with or without HT were determined . It was in vivo and increase drug accumulation in affected organ sites [in vivo. The higher tumor accumulation of OXP for both NTSL and TSL was perhaps related to the enhanced permeability and retention (EPR) effect [in vivo and that encapsulated drugs could be released immediately once TSL was combined with HT.Relatively low efficacy had been reported for OXP injection, and it was believed that this low efficacy was due to its pharmacokinetic properties, such as high irreversible binding to plasma proteins, tissue proteins and erythrocytes . For thian sites , and thean sites . The hig) effect . Unfortu) effect , 40. So,in vitro was displayed for 4 days at 37°C and for 6 months at 4°C. The distinguished antitumor activity of TSL combined with HT was also certified. Taken together, the OXP TSL had an optimal release timing and efficiency, marked antitumor activity, and high stability. This system might provide an opportunity to improve the therapeutic index of OXP and offer an evocation for testing TSL in clinical trials.OXP TSL with an entrapment efficiency of approximately 90% and complete drug release within 10 min after triggering were obtained through conventional TSL formulation combined with poloxamer 188. The high stability of these TSL


While natural microbial communities are composed of a mix of microbes with often unknown functions, the construction of synthetic microbial communities allows for the generation of defined systems with reduced complexity. Used in a top-down approach, synthetic communities serve as model systems to ask questions about the performance and stability of microbial communities. In a second, bottom-up approach, synthetic microbial communities are used to study which conditions are necessary to generate interaction patterns like symbiosis or competition, and how higher order community structure can emerge from these. Besides their obvious value as model systems to understand the structure, function and evolution of microbial communities as complex dynamical systems, synthetic communities can also open up new avenues for biotechnological applications. Current Opinion in Microbiology 2014, 18:72–77Cell regulationThis review comes from a themed issue on Cecília Maria Arraiano and Gregory M CookEdited by Issue and the EditorialFor a complete overview see the Available online 14th March 20141369-5274/$ – see front matter, © 2014 The Authors. Published by Elsevier Ltd. All rights reserved.http://dx.doi.org/10.1016/j.mib.2014.02.002Recent years have seen a surge in the analysis of microbial communities thanks to the development and cost-reduction in sequencing technologies. The continuing application of these has led to the characterisation of species diversity in different natural communities from the oceans to the human gut . DespiteWhile even the simplest of the natural microbial communities characterised to date contain tens to more than thousands of species , it is uA promising way to overcome the difficulties associated with studying natural communities is to create artificial communities that retain the key features of their natural counterparts. These can then act as a model system to assess the role of key ecological, structural and functional features of communities in a controlled way. Here, we define a synthetic community as one that is created artificially by co-culturing of select (two or many) species under a  well-defined media. While the individual species in such a community can be further engineered, we do not require presence of synthetically engineered species for a community to be defined as synthetic. Towards an increased understanding of natural communities, these synthetic communities can be utilised in two general ways, which we classify as function-based and interaction-based.This top-down approach focuses on determining a functional definition for a community first and then using this definition to characterise community structure and dynamics in detail. The value of having a defined ‘function’ for a microbial community allows us to measure the extent and stability of this function and, perhaps more importantly, gives us a way to compare different communities with the same function.Within this approach, ‘natural’ microbial communities utilised in biotechnology are of interest, as they are operated under relatively well-defined conditions and where the production or degradation of a target substance can act as an objective measure of performance. In anaerobic digestion and wastewater-treatment plants, for example, production of biogas or reduction of toxic organic compounds can be taken as the community function. This allows long-term measuring of parameters such as functional stability and performance, and correlation of these with community composition . While pet al. found an improvement in functional efficiency with increasing diversity [et al. used indirect control on radial diversification of Pseudomonas fluorescens to show that productivity (i.e. the rate of production of organic matter by a community) displays a unimodal relation to diversity, peaking at intermediate levels of diversity [This limitation can be surpassed by directly manipulating the level of diversity in a carefully designed synthetic community, which allows exploring the relation between community structure and function in a controlled way. For example, by defining mercury removal as the community function and creating communities with different levels of diversity, Von Canstein iversity . Similariversity .The functional approach to communities is not only useful to study the relations between key properties such as diversity, function, and stability, but also allows deriving a mechanistic understanding of community structure. In the context of anaerobic digestion, the definition of community function as conversion of complex organic matter into methane has allowed a mechanistic understanding of the underlying communities as species assemblies interlinked through the different levels of the degradation process . This meIn this bottom-up approach the focus is on identifying common interaction patterns and processes among bacterial species, with the expectation that these could be key determinants of the overall community structure and dynamics. Species interactions in microbial communities can be either metabolism-based or be driven by social traits. To date, social interactions among microbes has attracted attention and several good reviews have summarised the study of these interactions in synthetic as well as natural microbial communities •,16–18. The commonly considered social interactions of competition and cooperation are only two of all possible interactions among microbial species. The net effect of an organism A on a second organism B can be neutral, positive or negative, resulting in the number of possible mutual interactions between two organisms to be 9. Since the directionality of a reaction is not of interest for the type of interaction (i.e. +/− = −/+), there are six basal interaction patterns that make up the minimal interaction motifs in microbial communities . While eet al. found the interactions between two randomly selected members of a beech tree hole community to be mostly competitive [It is hypothesised for example that cooperative interactions among the members of the community could be a major driver of community function and structure •. This ipetitive .et al. used engineered strains of Escherichia coli to analyze species dynamics resulting from predator-prey interactions (corresponding to a food chain with waste inhibition in metabolic-terms) [et al. used a similar approach to create a three-species interaction pattern corresponding to a rock-paper-scissors game [The potential role of the presence or absence of cooperation on community dynamics can also be analysed by synthetically engineering cooperation. Cooperation between two microbial strains can either be engineered by knocking out different essential genes in each of the strains , by specc-terms) , while Kors game .While such applications of synthetic biology in constructing synthetic communities were so far driven by an ecological view of interaction motifs, we believe that the construction of interactions using a metabolism-based view could be highly useful for several reasons. Firstly, ‘metabolic interaction motifs’ could be more easily linked to natural systems. Naturally prevalent motifs could be potentially identified by combining metagenomic and species co-occurrence analyses, with the graph-theoretical analyses of metabolic network models of each species. For example, the concept of ‘seed sets’, the set of metabolites a microbial species needs to acquire from the environment , could bSynthetic microbial communities can also be used to combine the function-first and interaction-first approaches summarised above. This can be achieved by creating synthetic communities where both species composition and community function are defined. The resulting systems provide important insights into the relation between community function, structure and dynamics. Examples of this combined approach include those that focused on characterising species interactions and stable performance in synthetic communities for cellulose degradation •,36.We believe that understanding metabolic interactions in microbial communities and the ability to artificially stabilise interactions between microbes will eventually allow us to better understand and harvest the full metabolic potential of the microbial world.Several challenges, however, need to be overcome for the rational engineering of microbial communities. The foremost of these is to achieve media compositions that can maintain multiple species. Given that media composition is a dynamic parameter of the system, linked to population dynamics, further development of metabolic as well as population dynamics models  need to We expect that as these challenges are overcome and rational engineering of synthetic communities becomes more mainstream and high-throughput, synthetic microbial communities will find more applications both in microbial ecology and in biotechnology. Especially with respect to biotechnology, the synthetic microbial community concept has a great potential for the future . A ratioSynthetic microbial communities are abstractions of natural systems that allow the in detail study and analysis of the fundamental building blocks and processes that compose a microbial community. Both the top-down and bottom-up approaches summarised above have yielded important results on simple communities and are paving the way for the assembly of higher order communities. With the aid of novel approaches such as micro bead encapsulation of a small number of microorganisms ••,47 micResearch into synthetic microbial communities is witnessing a re-incarnation after the first attempts in creating co-culture and tri-culture about several decades ago . We feel• of special interest•• of outstanding interestPapers of particular interest, published within the period of review, have been highlighted as:


The bioengineering of individual microbial organisms or microbial communities has great potential in agriculture, bioremediation and industry. Understanding community level drivers can improve community level functions to enhance desired outcomes in complex environments, whereas individual microbes can be reduced to a programmable biological unit for specific output goals. While understanding the bioengineering potential of both approaches leads to a wide range of potential uses, public acceptance of such technology may be the greatest hindrance to its application. Public perceptions and expectations of “naturalness,” as well as notions of disgust and dread, may delay the development of such technologies to their full benefit. We discuss these bioengineering approaches and draw on the psychological literature to suggest strategies that scientists can use to allay public concerns over the implementation of this technology. Cells within a mixed community interact, communicate, influence and alter the biochemical and physiological processes among the members. This vast potential among microorganisms provides a tremendous environmental, industrial and agricultural potential to be used as a tool.Microorganisms are present in almost every habitat on earth. Microbes have shaped our planet over billions of years and are the drivers of global and local carbon, oxygen, nitrogen, sulfur, and phosphorus cycles that form the basis of life on our planet.The simplest of natural communities still contains a wide range of species,Microbes within mixed communities can undergo a wide range of interactions that can be broadly characterized into commensalism, competition, predation, cooperation, amensalism or no interaction at all.Synthetic communities, microbial communities created from defined constituents, are greatly simplified to allow a bottom up approach for isolating specific interactions and providing in depth information from communities comprising as few as just 2 species. Numerous studies have followed the initial approach to reduce complexity to focus on specific interactions. The study of syntrophic interactions has benefited greatly by establishment of co-culture of the syntrophic partners to allow investigation of their interactions. Initial culturing was only possible with the use of both syntrophic partners in a 2-species community.Microbial communities undergo a number of interactions, the most significant being metabolic, that need to be understood if desired outcomes are to be achieved. These interactions are outlined in One of the most important bioengineered communities currently in widespread use is wastewater treatment. Wastewater treatment plants exist worldwide with mixed inputs, but all with the aim of treating wastewater and removing contaminants. Often, open systems involving microbial populations can be difficult to predict and seem to occur almost at random in their initial stages.2 as a carbon source.Electromicrobiology is now providing the ability to add energy into a community in a specifically targeted manner.E. coli is an example of an early success in engineered pure cultures.Biorefinery is seen as a key concept in the development of industrial biotechnology.Synthetic biology has the goal of overcoming these limitations by reducing the microorganism to a programmable chassis whose functions can be predicted using standardized DNA building blocks.Synthetic biology has the potential to provide access to a huge range of diverse complex molecules with a wide range of applications. Environmental and production constraints can be removed through design and new and novel compounds produced. Synthetic biology has the promise to reinvigorate drug discovery pipelines and is stimulating a range of bioengineering tools.possible in microbial communities, it is also important to establish the conditions under which biotechnology is acceptable in human communities. Citizens' scepticism about agricultural biotechnology has driven consumer backlash, which has led to financial losses for agricultural biotechnology organizations and delays in regulatory approval of GM crops.While it is important to establish the biotechnology that is Several studies have demonstrated that people's attitudes to GM foods are not determined by a simple calculation of potential risks and benefits, but are driven by several factors.Human concerns about interfering with a natural entity can be divided into 2 categories: instrumental and ideational. Instrumental concerns are essentially an assessment of risk and benefit, and are centered on the view that preservation of the natural world is ultimately better  for the success and even survival of the human race. There are specific advantages to natural entities – they are thought to be healthier, more appealing, or kinder to the environment than non-natural entities. Ideational concerns operate independent of concerns for human welfare: the ideational view posits that the original form is, by its nature, the best form, and it is morally correct to preserve and defend the natural world. The natural entity is preferred because it is simply “better” – more moral, more beautiful, or simply “right.”Ideational concerns involve a moral element – the preservation of nature as a moral imperative – and psychologists have established that the emotional response elicited by moral violations is disgust , scientists must also address the public's moral concerns about interfering with nature. Recently, food security has re-emerged as a global issue, as the specter of food shortages is raised by population growth, increasing demand from more affluent countries, and climate change.Finally, scientists and policy makers should be aware that one factor affecting the acceptability of risk is voluntariness: voluntarily chosen risks are perceived as more acceptable than those that are imposed.in situ, exploiting naturally occurring microbial communities. In an almost opposite approach, synthetic biology is removing complexity to engineering microorganisms that are programmable for specific tasks. Advances are making these applications more useful with products being produced for market. Interestingly, there is still a divide between acceptance of these different approaches to bioengineering microbial communities for beneficial process and products. The psychological literature leads us to conclude that people will find cultivation of microbial communities more palatable when it is done via a process of natural selection in situ than through modification at the genetic level. If genetic modification is employed, the species from which genes are derived will be important in determining public support, as will the characteristics of the public audience  managing the biotechnology). The psychological literature also suggests some proactive mechanisms by which we can make biotechnology more palatable to the human communities in which it will be applied. Understanding these human responses to biotechnology can inform our strategies for cooperation and communication with the public, better enabling us to allay any unnecessary fears held in the community.The bioengineering of microbial communities for agricultural and industrial uses has great potential. Current research utilizing top down and bottom up approaches is providing insights and important mechanistic understanding of processes and interactions that may be exploited in the environment. Electromicrobiology is allowing the targeted input of energy to drive these processes