Using wearable devices to monitor respiration rate is essential for reducing the risk of death or permanent injury in patients. Improving the performance and safety of these devices and reducing their environmental footprint could advance the currently used health monitoring technologies. Here, we report high-performance, flexible bioprotonic devices made entirely of biodegradable biomaterials. This smart sensor satisfies all the requirements for monitoring human breathing states, including noncontact characteristic and the ability to discriminate humidity stimuli with ultrahigh sensitivity, rapid response time, and excellent cycling stability. In addition, the device can completely decompose after its service life, which reduces the risk to the human body. The cytotoxicity test demonstrates that the device shows good biocompatibility based on the viability of human skin fibroblast-HSAS1 cells and human umbilical vein endothelial (HUVECs), illustrating the safety of the sensor upon integration with the human skin. Electronic sensors, such as wearable physiological monitoring and stimulating devices, have been widely used in biomedical applications , 2. SuchNatural materials, those produced from renewable and abundant feedstocks and having intrinsically biocompatibility and biodegradability, have been used in various applications , 10, sucμm thick degradable biocomposite film   has been subject to extensive biocompatibility studies that have demonstrated that it offers cell and tissue biocompatibilities comparable to those of other reference biodegradable polymers for transient applications. In the present study, we further confirmed the biocompatibility of the natural degradable biocomposite film for direct interfacing with the human skin or living tissue via cytotoxicity tests. In the biocompatibility tests, human skin fibroblast-HSAS1 and HUVEC were exposed to the degradable biocomposite film  curves (τres/τrecov), defined as the time required for 90% of the current increase or decrease [Finite element analysis (FEA), which combines both humidity and proton density simulations, revealed that the sensor has high humidity-sensing performance. The increase in the sensitivity is due to the increase in the number of water molecules adsorbed by the biomaterial in the channels at the same relative humidity, which results in more proton density for transport and substantially influences the conductivity of the channel. ) curves  exhibit ) curves . The resdecrease , were evTo evaluate the ability of these sensors to detect physiological behaviors related to humidity in the human body, we measured the respiration rate change before and after human exercise . Since rIn addition to its application in medicine, our sensor can also be used as a switch in contactless controllers due to its superior response to fingertip humidity , 30. PosTo further indicate the noncontact humidity-sensing characteristics of this sensor array, one fingertip held close to the sensor matrix allows the individual current of each pixel to be measured. The pixel currents in the sensor array rapidly increased when the finger was near the center of the sensor array, as illustrated in Assessing the biodegradability of flexible sensors is crucial not only for modern biomedical technologies but also for cutting-edge wearable electronics . The uniThe bioprotonic flexible devices based on the functional polysaccharides reported here show high humidity sensitivity for monitoring the human body and the environment, and the devices are fully biocompatible and biodegradable, allowing the safe monitoring of patients while avoiding the risks of permanent injury associated with the integration of devices with the human skin and reducing the environmental footprint of these devices. These bioprotonic flexible devices exhibit high-humidity sensitivity, great flexibility, and excellent noncontact characteristics. These features will be useful for monitoring ambient conditions and various diseases of the human body, from human environmental comfort to chronic diseases. In addition, utilizing the rapid response of the sensor to fingertip humidity at different distances, a smart noncontact control switch system was successfully prepared. Thus, this is suitable for practical flexible sensors for use in stimulating, recording, sensing, and medical monitoring and treatment, not only in the medical applications explored here but also in the field of intelligent human-machine systems.In brief, 0.9 g of chitosan and 0.1 of active lignin (0.1 g) were added to 0.5 M, 10 mL of acetic acid. An advanced ultrasound instrument (Cole Parmer 750 W) was used to treat the mixture with 30% power for 30 min. The resulting dispersion to form homogeneous solution was stirred for 20 h, and the supernatant was retained to be utilized for the biocomposite film forming.μm on a flexible PI substrate as the sensing layer. The flexible PI substrate was ultrasonicated in acetone, deionized water, and isopropanol and then treated with oxygen plasma for 1 min at 150 W before spin coating (Technics MicroRIE Series 800). To the process for fabricating the bioprotonic flexible humidity sensors on a biocomposite film was the same as that previously reported by our group [μm thick biocomposite film via a shadow mask. The first layer of Cr is used to generate nucleation sites on the 60 nm gold electrode layer deposited at 150°C, which was used for adhesion.The sensor was assembled as described in Figure ur group , 39. Au/μm thick functionalized polysaccharides biocomposite film via spin coating and thermal evaporation.The electrodes were fabricated by evaporating Mg/Fe (60/10 nm thick) on top of a 20 The humidity measurement set-up consisted of a Keithley 4200-SCS System SourceMeter (Keithley) used in combination with a humidity generator (DHD-II), while the RH was measured with a humidity generator (DHD-II). Measurements were performed in a different controlled RH atmosphere at room temperature. Digital cameras  are used to collect optical images of flexible devices.G represents the conductivity of the biocomposite film, a represents the limit saturation value (when humidity reaches infinity), and Hd represents RH. Electrical  properties of our materials were affected by exposure to different RH levels. To calculate the conductivity of the biocomposite film, we first estimated a = 1.29707e−6, Hd0 = 84.74426, and k = 0.04437 in this case. The electrical properties of our materials were then calculated by imported COMSOL tool.Electrical  properties of the materials were obtained by using the Gompertz equation together throughout a finite element method . The relationship between conductivity of the materials and RH was determined by solving the following equation:RH distributions in the surrounding finger were simulated by using a CFD model, Fluent (version 6.1). In this model, air acts as a mixture of water vapor and dry air, and the finger acts as fixed fluids with ordinary wall characteristics. This makes it possible to simulate the transfer of moisture on the surface of the finger. Here, we choose a finger with a thickness of 10 mm and used one side of the finger as a fixed fluid wall. The humidity distribution was simulated in the range of 30 mm × 30 mm on one side. Relative pressure in the set area is 0, finger temperature is 37°C, and finger surface humidity is 95-100%RH. The RH distribution was estimated by the simple equation of Navier-Stokes.5 cells mL−1, as counted by a hemocytometer. The cells were seeded on the biocomposite film with a density of 2 × 104 cells in the wells of the tissue culture plates and maintained in culture medium supplemented with a 10% of fetal bovine serum and 10% of the pancreatic enzyme-EDTA in a 37°C incubator  with 5% CO2. On 48 h, 96 h, and 144 h  of in vitro culture, two cells were stained by 10 μL calcein AM and 10 μL polyimide for 15-20 min and then washed three times with PBS. The morphologies of the cells on the hydrogel surfaces were obtained by using a laser scanning confocal microscope .Human skin fibroblast-HSAS1 and HUVEC  were sterilized under high temperature and pressure. The cells were suspended in the culture medium to obtain a cell density of 4 × 10


N-acetylglucosamine kinase (NAGK) promotes dynein functionality and suggested this might promote aggregate removal and effectively address proteinopathies. Here, we report NAGK interacts with dynein light chain roadblock type 1 (DYNLRB1) and efficiently suppresses mutant huntingtin (mHtt) (Q74) and α-synuclein (α-syn) A53T aggregation in mouse brain cells. A kinase-inactive NAGKD107A also efficiently cleared Q74 aggregates. Yeast two-hybrid selection and in silico protein–protein docking analysis showed the small domain of NAGK (NAGK-DS) binds to the C-terminal of DYNLRB1. Furthermore, a small peptide derived from NAGK-DS interfered with Q74 clearance. We propose binding of NAGK-DS to DYNLRB1 ‘pushes up’ the tail of dynein light chain and confers momentum for inactive phi- to active open-dynein transition.Emerging evidence indicates that neurodegenerative diseases (NDs) result from a failure to clear toxic protein aggregates rather than from their generation. We previously showed  However, cells are endowed with complex surveillance machineries that identify faulty proteins in need of repair or disposal with the aid of chaperones, which act as central coordinators3. When a native folding state cannot be attained, chaperones typically label the misfolded protein for proteolytic removal via the ubiquitin (Ub)–proteasomal system (UPS)4. However, under proteotoxic stress, the capacity of the chaperone-UPS system may be swamped by the overproduction of misfolded proteins5. In such cases, aggregation-prone proteins not degraded may be transported along microtubules (MTs) in a retrograde manner to a microtubule organizing center (MTOC) to form an “aggresome” in the juxtanuclear region6. Aggresomes are then captured by lysosomes and cleared by the autophagy-lysosome pathway (ALP)7.Excessive accumulation and aggregation of a specific protein, either a wild or mutant type, is referred to as proteinopathy8. Dynein transports misfolded protein aggregates to MTOCs and many studies have reported direct or indirect evidence of dynein participation in NDs9. Although lysosomes are broadly distributed throughout cytoplasm, they concentrate in a central region surrounding the MTOC (the ‘perinuclear cloud’)10. Because protein aggregates might be transported by dynein motor to MTOCs to form “aggresomes”, it is reasonable to assume dynein activity increases accelerate the ALP. In this regard, N-acetylglucosamine kinase (NAGK) is a good candidate for promoting dynein activation. Specifically, NAGK interacts with dynein light chain roadblock type 1 (DYNLRB1)11 to promote dynein functions during mitosis12 and axonal13 and dendritic growth15. In the present study, we asked whether NAGK also promotes the clearance of protein aggregates. For this purpose, we tested two mutant proteins that are prone to aggregate; namely, mutant huntingtin (mHtt) with polyglutamine expansion that forms aggregates in HD and α-synuclein (α-syn) A53T that forms aggregates in PD.Cytoplasmic dynein is a minus end-directed microtubule motor protein and is involved in a diverse range of intracellular vesicular traffickingsp < 0.001) reduced the percentage of cells containing aggregates as compared with the DsRed2 control.We first investigated the effect of NAGK on mHtt aggregate formation in HEK293T cells (a human embryonic kidney cell-line). To facilitate aggregate formation, we transfected cells with pEGFP-Q74 (pQ74), which expresses EGFP-tagged HTT partial exon 1 (Q74) protein. At 72 h post-transfection, Q74 formed aggregates of various sizes in nuclei and cytoplasm Fig. , Q74. To16. For this purpose, neurons from rat embryonic (E19) cortices were cultured and co-transfected on DIV 2 with pQ74 plus pDsRed2-NAGK or with pDsRed2 as a control. After incubation for 72 h, Q74 aggregates were rarely seen in neurons co-transfected with pQ74 and pDsRed2-NAGK  reduced the percentage of neurons containing aggregates as compared with the DsRed2 control  reduced the percentage of aggregation-positive cells as compared with the DsRed2 control  plus pDsRed2-NAGK or with pDsRed2 as a control. After incubation for 72 h, cultures were double-stained with anti-α-syn and -RFP antibodies and then with DAPI Fig. . Controlrol Fig. .p < 0.01) in neurons co-transfected with pDsRed2-NAGK than with pDsRed2 , which had a dominant-negative effect on the non-canonical function of NAGK, that is, its effects were similar to those of sh-NAGK15. To investigate the effects of sh-NAGK and NAGK-DS, we triply co-transfected HEK293T cells with pQ74, pDsRed2, and a shRNA vector (pSh-NAGK) or a control mismatch vector (pMismatch). After incubation for 72 h, cells were double-immunostained with antibodies against GFP and RFP and nuclei were counterstained with DAPI. Q74 aggregates were seen in HEK293T cells transfected with pSh-NAGK  also exhibited Q74 aggregation . Furthermore, statistical analysis showed pSh-NAGK vector and pNAGK-DS significantly (p < 0.001) increased the percentage of aggregate-positive cells 15 might also suppress aggregate formation. For this purpose, we triply co-transfected HEK293T cells with pQ74, pDsRed2, and pDsRed2-NAGKD107A (pD107A). After incubation for 72 h, cells were double-stained with antibodies against GFP and RFP  and then DAPI stained. To our surprise, the exogenous expression of D107A suppressed the formation of Q74 aggregates  lower than that in the pMismatch plus pDsRed2 co-transfected control  targeting a coding region [418–438] of lls Fig. . The obsrol Fig. .Fig. 2EfS transfected neurons exhibited aggregates  increased the percentage of aggregate-positive neurons  in neurons suppressed Q74 aggregation  reduced the percentage of aggregate-positive cells versus mismatch RNA or DsRed2 controls  transfected with pQ74 and various combinations of pDsRed2-NAGK, pD107A, pNAGK-DS, pMismatch, pSh-NAGK, and pDsRed2. We found co-transfection with pSh-NAGK and pNAGK-DS significantly (p < 0.001) increased the proportions of large and medium-sized aggregates, whereas co-transfection with pDsRed2-NAGK and pD107A significantly (p < 0.001) reduced the proportions large and medium aggregates as compared with the pMismatch plus pDsRed2 control , medium (0.8–1.5 µm), or large (≥1.5 µm) see Fig.  and thenrol Fig. . Howeverant Fig. . Interesp < 0.01)   Fig. . Similar01) Fig.  and sign01) Fig. , indicat17. Therefore, we investigated the effect of NAGK on mitochondrial morphology in a cellular model of HD. HEK293T cells were co-transfected with pQ74, pCMV6-Myc-DDK-NAGK (pDDK-NAGK), and pMitoTimer, the latter of which encodes a mitochondria-targeting GFP that shifts irreversibly to red fluorescence when oxidized18. After incubation for 24 h, cells were double-immunostained with antibodies against GFP and RFP. A series of optically dissected images of mitochondria along the z-axis were acquired; lower, middle, and upper layers are shown in Fig. p < 0.01) increased the proportion of filamentous mitochondria and markedly reduced (p < 0.001) those of fragmented and spherical mitochondria  mutation is known to be directly responsible for increasing ROS levels in neuronal and non-neuronal cells4. To observe the effect of NAGK on ROS levels, HEK293T cells were transfected with pQ74 or co-transfected with pQ74 and pDDK-NAGK. After incubation for 24 h, intercellular ROS levels were measured by treating cultures with CellROX Deep Red (Invitrogen). Co-transfected cells were found to fluoresce significantly less than pQ74 transfected cells  and pDsRed2 (p < 0.01) electroporated brains  and large (residues 118–344) domains, and the small domain interacts with the C-terminal DYNLRB1, as we previously reported11. Consistently, the resulting NAGK-DYNLRB1 complex exhibited similar orientations of NAGK to DYNLRB1, and thus, it was subjected to molecular dynamics simulation (MDS). Simulation stability was checked using root-mean-square deviations (RMSDs)  with NAGK, because an earlier report suggested DYNLRB1 exists as a dimer in dynein complexDs) Fig. , which sDs) Fig.  after 25Ds) Fig. . For morDs) Fig. . The 2D Ds) Fig. .Fig. 6Mo59AGVDPLVPLR69) binds specifically to the C-terminal DYNLRB1  reduced the percentage of aggregate-positive cells as compared with pDsRed2 transfected control cells, which reconfirmed our earlier results  as compared with pDsRed2-NAGK control cells. Collectively, these observations suggested that the designed peptide specifically inhibited the NAGK to DYNLRB1 interaction and inhibited Q74 clearance.We then examined whether peptide binding to DYNLRB1 influences the NAGK-DYNLRB1 interaction and affects aggregate clearance. For this purpose, we first co-transfected HEK293T cells with pQ74 and pDsRed2 or pDsRed2-NAGK, and 6 h later, transfected cells with different concentrations of the peptide. Remarkably, pDsRed2-NAGK transfection significantly 7, accelerated transport would aid aggregate clearance. Second, NAGK expression did not affect the number of small aggregates, whereas large and medium aggregates were significantly fewer in NAGK-overexpressing cells. Q74-expressing cells always exhibited green fluorescence, and small aggregates were consistently observed in cytoplasm. Although the threshold size of aggregates required for dynein transport is not known, our results indicate that an aggregate must attain a certain size before it is disposed of via the ALP. This suggestion regarding minimal aggregate size is supported by the gathering of scattered polyubiquitinated protein aggregates induced by HDAC6, which plays an essential role in transporting protein aggregates via microtubule tracts26, and thus, favors aggresome formation and autophagy27. HDAC6 binds to both polyubiquitinated aggregates and dynactin/p150Glued (a component of dynein motor complex), and links ubiquitinated proteins to dynein motor and promotes cargo transport to MTOC28. Thus, we believe the background green fluorescence observed in Q74-expressing cells was caused by small scattered aggregates.We found NAGK in DsRed2- or DDK-tagged forms efficiently reduced Q74 and α-syn A53T aggregates in cultured neuronal and non-neuronal cells and Q74 aggregates in mouse brains, which suggested NAGK either suppressed aggregate formation or promoted their removal. We favor the latter scenario for two reasons. First, NAGK promotes the function of cytoplasmic dynein30, and that oxidative stress can lead to non-specific post-translational modifications of proteins and contribute to protein aggregation. Hence, it is likely that protein aggregate clearance would reduce ROS levels and support mitochondrial health. Indeed, the present study shows NAGK overexpression significantly reduced numbers of dysfunctional spherical mitochondria and increased numbers of ‘thread-like’ healthy mitochondria in our HD cellular model, which suggests NAGK promoted ALP activity by dynein activation and consequently reduced ROS levels and mitochondrial damage.The present study shows that protein aggregate reduction by exogenous NAGK suppressed ROS generation and helped maintain a ‘thread-like’ mitochondrial morphology in our cellular model of HD. Extensive evidence shows dysregulation of autophagy increases oxidative stress, as has been demonstrated by pharmacological inhibitor and knockout studies14. This upregulation was found to be a non-canonical function of NAGK, because enzyme activity-nullified D107A mutant NAGK also upregulated dendritic arborization as effectively as the wild-type15. Furthermore, exogenous expression of the small domain of NAGK (NAGK-DS) resulted in dendrite degeneration15, indicating NAGK-DS played a negative-dominant effect by a structural role in dynein regulation. Indeed, the ectopic introduction of a small peptide derived from the C-terminal amino acids 74–96 of DYNLRB1 resulted in the stunting of hippocampal neuron axons13. In the present study, overexpression of NAGK-DS abrogated aggregate clearance by NAGK and aggravated aggregation, and the NAGK-DS-derived peptide K59AGVDPLVPLR69 nullified the effect of wild-type NAGK on Q74 clearance. These results all support that NAGK plays a structural role in dynein activation.The present study also shows that aggregate reduction is a non-canonical effect of NAGK. Previously, we reported NAGK is highly expressed in neurons, and that the exogenous expression of NAGK upregulated the formation of dendrites31. The phi- to open-dynein transition is also accompanied a conformation change of the 200-amino-acid N-terminal dimerization domain of the HC tail from a ‘twisted’ to a ‘parallel’ state. When dynein is bound to dynactin, the conformation of this region most resembles the parallel state32. Interestingly, the twisted to parallel transition correlates with small shifts in the relative position of the two ICs (IC A and IC B) and larger changes in the position of the LCs . Specifically, a small shift in the relative position of the IC A and IC B causes DYNLRB1 rotates through 25° and the LC8/Tctex density moves away from the HC neck33. We reason that NAGK binding to DYNLRB1 causes a shift in the relative position of the two ICs. To be specific, DYNLRB1 is composed of a 10-stranded β-sheet core, which provides a positively charged surface area with major protein–protein interaction sites for its partner, IC, through residues 79–82, 88, and 9020. Interestingly, this interaction domain of DYNLRB1 is also the NAGK binding site, as indicated by the present study and our previous report11. As shown by our molecular modeling studies, residues 59–69 in the small domain of NAGK are the major hotspots for DYNLRB1 binding. Thus, there seems to be a binding competition between NAGK and IC for DYNLRB1. If NAGK wins, it will bind DYNLRB1, causing a shift in the relative position of the two ICs and DYNLRB1 rotation, resulting in a phi- to open-dynein structural transition and a ‘push up’ event of the LC tails  trail from the heavy chain (HC) tailIn summary, we report NAGK acted in a non-canonical manner to reduce protein aggregates in neuronal and non-neuronal cellular models of HD and PD, and that these suppressions of protein aggregates also prevented mitochondrial damage and reduced ROS production. At the molecular level, the small domain of NAGK interacted with the C-terminal DYNLRB1, which may have activated dynein motor.34 pEGFP-Q74 was a gift from David Rubinsztein  and pHM6-alphasynuclein-A53T was a gift from David Rubinsztein 35. pMitoTimer was a gift from Zhen Yan 18. pDsRed2 vector was purchased from ClonTech  and pCMV6-Myc-DDK-tagged rat NAGK (pDDK-NAGK) was from OriGene Technologies, Inc. . pDsRed2-tagged wild-type NAGK (pDsRed2-NAGK), pEGFP-tagged point mutant NAGK (pEGFP-NAGKD107A), deletion mutant containing only the small domain of NAGK (pEGFP-NAGK-DS), NAGK short hairpin (pSh-NAGK), and mismatch RNA vectors (pMismatch) were previously described15. His-tagged NAGK (pENTER-CMV-NAGK), DYNC1LI1 (pENTER-CMV-DYNC1LI1), DYNLRB1 (pENTER-CMV-DYNLRB1) were purchased from Vigene Biosciences .The following antibodies were used at the indicated dilutions: rabbit polyclonal antibody against RFP  and against DYNLRB1 ; mouse monoclonal antibodies against GFP , against α-syn , against NAGK  and DYNC1LI1 . Secondary antibodies (Alexa Fluor 488-conjugated goat anti-mouse IgG and Alexa Flour 568-conjugated goat anti-rabbit IgG) were from Invitrogen . pEGFP-Q74 36. Experiments were approved beforehand by the Institutional Animal Care and Use Committee of the College of Medicine, Dongguk University . Cells were initially plated in MACS®Neuro Medium  supplemented with MACS NeuroBrew®-21, 45.95 µM glutamate, 500 µM glutamine, 25 µM 2-mercaptoethanol, and 1% penicillin-streptomycin, and fed every four days with the same medium without glutamate or 2-mercaptoethanol supplementation. HEK293T cells were cultured on polylysine-coated glass coverslips in DMEM (Invitrogen) containing 10% fetal bovine serum and 1% penicillin-streptomycin. Cells were transfected using Lipofectamine® 2000 reagent (Invitrogen), and immunostained after fixing with paraformaldehyde and methanol37.Cortical cells from embryonic day 19 (E19) Sprague-Dawley rat brains  were cultured as previously described2 atmosphere and washed twice with PBS. Fluorescent images were acquired using an Olympus BX53 microscope . Mean fluorescence intensities were measured using Image J software .Transfected HEK293T cells were incubated with 5 µM CellROX Deep Red (Invitrogen) for 30 min at 37° C in a 5% CO38. In brief, postnatal day 1 (P1) ICR mice were anesthetized by hypothermia, and then skin and skull were pierced with a sharp glass microcapillary containing a solution of plasmid  in Tris-EDTA buffer containing 0.5% Fast Green. DNA solution (2 µl) was injected into lateral ventricles (LVs), and injected brains were immediately electroporated with a tweezers-type electrode using an ECM 830 electroporator . Five pulses of 100 V of 50 ms duration were administered with a 950 ms pause between pulses. Electroporated animals were placed on a hot pad at 37 °C for several minutes and then returned to their mother. Pups were anesthetized by hypothermia 2 days later, and brains were isolated, fixed for 2 h at RT in 4% (w/v) PFA, washed in PBS, and incorporated into agarose (5%) blocks, which were then sectioned (30 μm) with a vibratome . Sections were mounted on slides and images were acquired using a Leica DM IRE2 Research Microscope . Experiments were approved beforehand by the Institutional Animal Care and Use Committee of the College of Medicine, Dongguk University.Electroporation was essentially performed as described by Ito et al.® 2000 reagent (Invitrogen). The transfection efficiencies of all plasmids ranged from 70 to 80%. After incubation for 48 h, cells were washed with cold PBS and lysed in lysis buffer  containing protease inhibitor cocktail . The supernatant was allowed to bind with MagListo™ Ni-NTA magnetic silica resin  and pulled down according to the manufacturer’s instructions. After washing four times with binding buffer, His-tagged protein was eluted using elution buffer . The eluted proteins were separated by SDS-PAGE (15% Tricine-SDS-PAGE in the case of DYNLRB1) gel and transferred to PVDF membranes, which were incubated with primary antibodies: anti-NAGK , anti-DYNC1LI1 , or anti-DYNLRB1 . After rinsing with TTBS (0.05% Tween-20 in TBS), membranes were incubated with horse radish peroxidase-conjugated secondary antibodies , and blots were detected using an ECL detection kit . In some experiments, a stripping buffer was used to strip membranes , and hybridization was performed with different primary and secondary antibodies.HEK293T cells were cultured in DMEM (Invitrogen) containing 10% fetal bovine serum and 1% penicillin-streptomycin. Cells were transfected with His-tagged plasmids  using Lipofectaminehttps://bmm.crick.ac.uk/svc-bmm-swarmdock/) server39, which uses the SwarmDock algorithm to predict interactions between two proteins while maintaining flexibility. Before docking, the three-dimensional structures of NAGK and DYNLRB1 were downloaded from the protein databank and prepared for docking simulation by adding hydrogens, adjusting bond orders and charges, and deleting water molecules using the protein preparation wizard of Schrödinger 2017-1 . All structures were optimized at neutral pH and then some thiol and hydroxyl groups, amide groups of asparagines, glutamines, and the imidazole rings of histidines, protonation states of histidines, aspartic acids and glutamic acids were readjusted. Force field OPLS_2005, minimization was then performed with maximum heavy atom RMSD set at 0.30 Å. Resultant docked complexes were further subjected to binding energy calculations using the FoldX40 program, which uses an empirical force field algorithm to calculate ΔG in kcal/mol and considers energy function terms including van der Waals, solvation, H-bond, electrostatic and entropic terms for the backbones and side chains of proteins and protein complexes.Molecular modeling of DYNLRB1-NAGK complex was performed by protein–protein docking simulation using the SwarmDock  solvation system at a density of 0.997 g/L and determined acid dissociation constant values (pKa). To maintain physiological conditions, the pH of the system was set at 7.4. Protonation states of all amino acids were calculated using a combination of the H-bonding network and the SCWRL algorithm42. Na+ and Cl− ions were added to neutralize the system, and a simulated annealing protocol was used to reduce system conformational stress. The Ewald particle mesh (PME) was applied to detect long-range electrostatic interactions using 8 Å as distance cut-off. Molecular dynamics simulation was conducted for 92 ns and the Berendsen thermostat was then applied at a time-step interval of 2.00 fs, using multiple time-step algorithms43. The pressure was kept constant, and trajectories were saved at 10-ps intervals. All simulation phases were run using a preinstalled macro (md_run.mcr) in YASARA suite, and results were analyzed using YASARA and VMD 44 tools. Finally, the most stable simulation structure was retrieved by free energy landscape (FEL) analysis45. Protein stability was assessed using Gibb’s free energy, calculated as follows:KB is Boltzmann’s constant, T is temperature (300 K), Ni and Nmax are population in bin I and the most inhabited population bin, respectively. A color code model , as previously described in Fig.  depicts 59AGVDPLVPLR69) from its small domain was custom made by GL Biochem Ltd. . The binding interaction between NAGK peptide and DYNLRB1 was analyzed over 50 ns by MDS, and this was followed with a protocol similar to that described above for DYNLRB1-NAGK complex. For inhibition assays, HEK293T cells were seeded in 24-well plates and maintained in high-glucose Dulbecco’s modified Eagle medium  supplemented with 10% fetal bovine serum (Life Technologies) and incubated for 24 h at 37 °C and in a 5% CO2/95% air atmosphere. Cells were then transiently co-transfected with pEGFP-Q7434 and pDsRed2 or pDsRed2-NAGK plasmids using the Lipofectamine 2000 (Invitrogen) transfection kit. After 6 h of transfection, 0.5, 0.75, or 1.0 μg of NAGK peptide was co-transfected with Alexa Fluor 647-conjugated goat anti-mouse IgG using Pierce protein transfection reagent . Briefly, 2.5 µL of Pierce Reagent was mixed with 0.5, 0.75, or 1.0 μg of NAGK peptide and 1.0 μl of antibody in 25 μl of PBS, incubated for 5 min, and then mixed with 250 µl of serum-free medium. Cells were then incubated in this serum-free medium containing complex and incubated for ~48 h with subsequent feeding medium, and observed under an epifluorescence microscope 37.The NAGK peptide , and GraphPad Prism v 8.0 .Numbers of aggregates, shapes of mitochondria, and ROS levels were determined using three independent experiments (and results are presented as means ± SDs). Counting was performed in a blinded way by two experienced independent investigators. Animals were taken from random cages within each cohort. Sample sizes were chosen based on considerations of data variability, but were never <5. The Student’s Supplementary Figure LegendsFigure S1.Figure S2.Figure S3.


We present a graphene-based biosensor selective to recombinant cyanovirin-N (rCV-N), an antiviral protein that has proven to be an effective microbicide to inhibit HIV replication. We modified the graphene monolayer devices with 1-pyrenebutanoic acid succinimidyl ester, which interacts with both graphene and the primary and secondary amines of antibodies. By monitoring the change in the electrical resistance of the device, we were able to detect rCV-N in solutions in the range of 0.01 to 10 ng/mL, and found that the detection limit was 0.45 pg/mL, which is much smaller than that obtained with currently available techniques. This is important for applications of this microbicide against HIV, since it may be produced at a large scale from soya bean seeds processed using the available industrial processing technologies. The sensor showed high sensitivity, selectivity, and reproducibility. The human immunodeficiency virus (HIV) is an infection that attacks the human immune system, and currently is considered by the World Health Organization (WHO) a global epidemic. Data from the WHO indicate that by 2018, there were 37.9 million people worldwide living with HIV, of which 1.7 million were infected only in that year—a 4.5% increase in the number of infected people. To reduce this number, it is important to develop new methods of inhibiting HIV transmission and to improve current methods of prevention. It was shown that cyanovirin-N (CV-N) ), with a correlation coefficient of 0.93 for a detectable range from 0.01 ng/mL to 10 ng/mL. We estimated the detection limit CL = 0.45 pg/mL (40.9 fM) for this device by determining the concentration at which ∆R is equal to the average change in the resistance for PBS solutions (blank) plus 3σ, where σ = 0.3% is the standard deviation. This detection limit is much lower than that obtained for graphene-based immunosensors for other proteins [We repeated these measurements for three different devices and obtained consistent results. The inset in proteins ,31,32,33To verify the reproducibility of the results, we fabricated another four graphene ISFET devices and placed onto each one a droplet of 0.01 ng/mL of rCV-N. The percentage changes in the resistance of these devices, shown in We developed a biosensor based on a graphene ISFET with a high selectivity and sensitivity to rCV-N, a protein that is a very promising microbicide against HIV. We have shown that the antibody-rCV-N conjugation changes the electrical resistance of the graphene ISFET with a limit of detection of 0.45 pg/mL (40.9 fM) and a detection range of 0.01 to 10 ng/mL. Due to the relative simplicity of the fabrication process and the high selectivity and sensitivity of the graphene ISFET for rCV-N, this sensor may be used to quantify this protein during the industrial processing of soya bean seeds, which may potentially be used as an anti-HIV resource.


Furthermore, the GH shift can be positive or negative depending on the layer number of BlueP/TMDCs and graphene. For sensing performance, the highest sensitivity of 2.767 × 107λ/RIU is realized, which is 5152.7 times higher than the traditional Ag-SPR structure, 2470.5 times of Ag-ITO, 2159.2 times of Ag-ITO-BlueP/WS2, and 688.9 times of Ag-ITO–graphene. Therefore, such configuration with GH shift can be used in various chemical, biomedical and optical sensing fields.Surface plasmon resonance (SPR) with two-dimensional (2D) materials is proposed to enhance the sensitivity of sensors. A novel Goos–Hänchen (GH) shift sensing scheme based on blue phosphorene (BlueP)/transition metal dichalogenides (TMDCs) and graphene structure is proposed. The significantly enhanced GH shift is obtained by optimizing the layers of BlueP/TMDCs and graphene. The maximum GH shift of the hybrid structure of Ag-Indium tin oxide (ITO)-BlueP/WS The Goos-Hänchen (GH) shift refers to the lateral spatial shift of the center of mass of the bounded beam relative to the geometric prediction . The GH The GH shift at the interface of two homogeneous materials with different optical properties is usually very small, almost equal to the incident wavelength . Leverag2–graphene hybrid, You et al. gained the highest GH shift of 235.8λ [2 monolayer and graphene bilayer [2 heterostructure to improve the sensitivity [Compared with other metal oxides, Indium tin oxide (ITO) has the characteristics of anti-corrosion, high transmittance, good conductivity, etc., which are widely used in the field of optical sensing ,22. The f 235.8λ . Through bilayer . Zhu et  bilayer . The Blu bilayer . In addi bilayer . Srivastsitivity . Sharma sitivity .2, BlueP/MoS2, BlueP/MoSe2, BlueP/WSe2) and graphene coated with ITO and Ag thin film is proposed. The maximum GH shift achieved was −2361λ for four layers BlueP/WS2 and monolayer graphene. In addition, the highest sensitivity for index sensing reached 2.767 × 107λ/RIU, which is 5152.7 times higher than the traditional Ag structure. We believe that this scheme with 2D materials has potential in highly sensitive sensors.In this paper, the hybrid structure of BlueP/TMDCs  glass with refractive index matching solution [The hybrid structure of Ag-ITO-BlueP/TMDCs–graphene based on the Kretschmann structure is shown in solution . The incn1) is obtained [In the following description of the refractive index (RI) in each layer, λ is the wavelength of the incident light, and its unit is um. In the first layer, the SF11 prism with RI (obtained :(1)n1=1.n2) is obtained [Then, in the second layer, BK7 glass with RI (obtained :(2)n2=1.n3) is obtained through the Drude model [The third layer is Ag thin film and its RI (de model :(3)n3=1−n4) is [The ITO film as fourth layer with RI (n4) is :(4)n4=3.Subsequently, the 2D material of BlueP/TMDCs and graphene with monolayer and RI is shown as n7) is obtained [A1 = 0.5666959820, A2 =0.1731900098, A3 =0.02095951857, A4 = 0.1125228406, t1= 0.005084151894, t2 = 0.01818488474, t3 = 0.02625439472, t4 = 10.73842352.The sensing medium is used for deionized (DI) water and its RI (obtained :(5)n7=∑in1 = 1.7786, n2 = 1.5151, n3 = 0.1350 + 3.9850i, n4 = 1.858 + 0.058i, n7 = 1.332 + bion. The bion represents the RI change of DI water. The thickness of BK7 glass and sensing medium is both 100 nm. In order to compare the properties of 2D materials, we set the thickness of Ag and ITO to 45 nm and 10 nm, respectively. When the number of graphene layers n ≤ 5, it is reasonable to treat monolayer as a non-interacting [Therefore, the RI is eracting . Hence, kd and kε (kε = kn2) . In order to analyze the reflectivity (pR) and phase (pψ), the transfer matrix method (TMM) and the Fresnel equation based on n-layer model are used [M is the structure of the transmission matrix (TM), and p-polarized light is gained through the following relationship [The thickness and dielectric constant of each layer are set as are used . The SPRtionship :(6)M=∏k=pr) of p-polarized light is related to the matrix as follows:p1 corresponds to the SF11 prism layer and p7 to the water layer. The pR and ψp of the p-polarized light are shown as [The total reflection coefficient (shown as :(10)Rp=|θ1 is the incident angle.We can use the fixed phase method to calculate the GH shift as followed:As shown in Although ITO plays a certain role in the increase of GH shift, the enhancement is still relatively small. Next, we study the influence of the graphene layer, as shown in 2 has the greatest contribution to Ag-ITO structure.Similarly, the BlueP/TMDCs is added to the Ag-ITO structure, as shown in From Subsequently, the BlueP/TMDCs monolayer and different number of graphene layers are added to the Ag-ITO structure of SPR, as shown in 2 and graphene, the highest GH shift is −385.8λ in BlueP/MoS2 bilayer and graphene monolayer. Then, the maximum GH shift with BlueP/WS2 four layers and graphene monolayer is -2361λ. Subsequently, the largest GH shift with BlueP/WSe2 three layers and graphene monolayer of -655.5λ is obtained. Finally, the highest GH shift of 456.9λ is obtained for both BlueP/MoSe2 and graphene monolayer. Therefore, in the Ag-ITO-BlueP/TMDCs–graphene structure, BlueP/WS2 has the greatest contribution to GH shift. The monolayer of graphene has the best performance.In n7) is changed, then and the GH shift is shown a giant red shift. Hence, the proposed new SPR heterostructure is used as a high sensitivity sensor based on shift variation. ∆GH is defined as highest value of the varying GH shift and the sensitivity is defined as pS’ = ∆GH/∆n7. We define the traditional SPR Ag, Ag-ITO, Ag-ITO-BlueP/WS2 (monolayer), Ag-ITO–graphene (monolayer), Ag-ITO-BlueP/WS2 (monolayer)–graphene (monolayer), Ag-ITO-BlueP/WS2 (four layers)–graphene (monolayer) structure as Structure I to Structure VI and show as PS’ with ΔGH and ∆n7 for Structure I to Structure VI are gained. Therefore, Structure VI is 5152.7 times higher than Structure I, 2470.5 times higher than Structure II, 2159.2 times higher than Structure III, and 688.9 times higher than Structure IV.In our study, the RI of the sensing medium (∆2 of 2D material and air was added to the SPR biosensor, the GH shift was improved to 40.5λ. We can find that 2D material and air can improve the GH shift of SPR sensor. In reference [2, the GH shift increased to 61.1λ. Therefore, compared with MoS2, graphene improves the performance of the SPR sensor more significantly. However, when graphene and MoS2 were added to the Au film of SPR sensor, the GH shift increased to 235.8λ for reference [5λ/RIU. In reference [2 replaced MoS2, the GH shift increased to 801.7λ, and the maximum sensitivity was 8.02 × 105λ/RIU. In this work, we use BlueP/TMDCs instead of TMDCs, and change metal into Ag, so as to construct the SPR sensor with Ag-ITO- BlueP/WS2–graphene hybrid structure. The optimal GH displacement is 2361λ and the maximum sensitivity is 2.767 × 107λ/RIU. Based on the analysis, we can see that our novel SPR sensor improves the GH shift and sensitivity significantly.Better compared with previous research results, eference , when theference , and theeference , when th2 four layers and graphene monolayer. The maximum GH shift is 2361 times that of the incident wavelength. Compared with the traditional SPR structure, the shift of the structure is increased by more than 39.21 times. In addition, by changing the number of BlueP/TMDCs layers, we can control the positive and negative shift of GH in the structure of BlueP/TMDCs–graphene. The maximum GH shift corresponding to the highest sensitivity is 2.767 × 107λ/RIU, which is 5152.7 times higher than the traditional SPR of Ag, 2462.8 times of Ag-ITO, 2159.2 times of Ag-ITO-BlueP/WS2, and 688.9 times of Ag-ITO–graphene. The sensing layer we use is deionized water, therefore, it is suitable as a sensing medium with a refractive index close to 1.332, to gain a higher sensitivity. This structure is expected to be a candidate for high-performance sensors.In this paper, the GH shift of the Kretschmann configuration combined with SPR-based 2D nanomaterials is studied. When SPPs were excited, we theoretically proved the influence of the number of graphene and BlueP/TMDCs layers on the GH shift, and obtained a huge GH shift by using the mixed structure of BlueP/WS


Sarcoidosis preceding a diagnosis of lymphoma has been a reported phenomenon termed sarcoidosis-lymphoma syndrome. Skeletal metastasis is extremely rare. Here, we detail a case of sarcoidosis-lymphoma syndrome presenting as a lumbar vertebral metastasis with suspected associated intracranial lesions. A 72-year-old man with a history of follicular lymphoma presented with symptomatic central nervous system (CNS) lesions with concurrent lumbar vertebral metastases visualized with CT and MRI. Rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisone (R-CHOP) with dexamethasone treatment resulted in significant radiographic regression of his intracranial lesions with dramatic symptomatic improvement. Out of concern for compression fracture of his lytic lumbar lesions, kyphoplasty with biopsy was performed showing lymphocytes that were positive for cluster-of-differentiation 10 (CD10), CD20, and B-cell lymphoma 2 (Bcl2). The patient was diagnosed with CNS and vertebral sarcoidosis-lymphoma syndrome and began treatment with high-dose methotrexate. Including the present case, only four occurrences of sarcoidosis-lymphoma syndrome with bony involvement have been described. We detail our own experience and summarize all previous literature. While rare, sarcoidosis-lymphoma may present with CNS and lytic bone involvement; in these cases, symptomatic severity, as well as an effective response to steroid treatment, underscore the importance of an accurate and prompt diagnosis. Sarcoidosis-lymphoma syndrome describes the rare phenomena in which a diagnosis of lymphoma is made in the setting of chronic sarcoidosis . IncidenIt is extremely rare for the diagnosis of lymphoma to precede sarcoidosis, as well as to include skeletal involvement. To date, there have only been three reports published in the literature where patients have presented with bony metastasis of sarcoidosis-lymphoma syndrome with only one study showing vertebral involvement. We present a case in which L5 biopsy revealed noncaseating granulomatous cells in the vertebral body following the identification of central nervous system (CNS) and spinal lesions with imaging, with a history of lymphoma.Our patient presented with initial focal bulbar neurologic deficit and headache prior to L5 biopsy which resolved with treatment involving Dexamethasone, Keppra, and Fioricet. Lesion size regressed significantly since initial encounter. One-month post-L5 biopsy and kyphoplasty, the patient returned with worsened neurological condition and for consultation. Scattered non-caseating granulomas with multinucleated giant cells were found from the biopsy and the patient was started on high dose methotrexate.A 72-year-old man with a history of basal cell carcinoma, squamous cell carcinoma, and low-grade follicular lymphoma was referred to our clinic for evaluation of diplopia, headache, tongue paralysis, dysarthria, and CNS lesions. Approximately two months prior to presentation, the patient developed progressively worsening double vision and headache while driving warranting emergency department admission. Head CT revealed cerebral edema and concomitant MRI demonstrated multiple ring-enhancing, intracranial lesions in the third ventricle and thalamus as well as lumbar spinal lesions consistent with metastatic disease. Abdominal and thoracic CT also showed diffuse lymphadenopathy in mediastinal, paraaortic, retroperitoneal, and axillary lymph nodes. Left axillary node biopsy showed low-grade follicular lymphoma that was positive for cluster-of-differentiation 10 (CD10), CD20, and B-cell lymphoma 2 (Bcl2) as well as fluorescence in situ hybridization (FISH) positive for t. Dexamethasone, Keppra, and Fioricet were initiated with symptom improvement and the patient was referred to our clinic for further evaluation. At the time of admission, the patient’s neurologic symptoms had resolved, and steroids were discontinued. Repeat MRI showed significant regression in lesion size rendering them too small to safely biopsy. The patient was discharged without an official diagnosis for his CNS and spinal lesions but began rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisone (R-CHOP) for his lymphoma . Scatter mitoses were present in addition to scattered non-caseating granulomas with multinucleated giant cells Fig. . Given hHere, we present a case of a 72-year-old man with CNS and vertebral sarcoidosis-lymphoma syndrome treated with R-CHOP, steroids, and high-dose methotrexate. Sarcoidosis is a chronic, multi-system disease of unknown origin characterized by the presence of non-caseating granulomas . The cliDespite previously reported cases of sarcoidosis-lymphoma metastases invading soft tissue, boney involvement is rare , 10. OurThe relationship between sarcoidosis and lymphoma is well-established, supported by a finding demonstrating an increased risk of 14.1% of Hodgkin’s lymphoma in patients with sarcoidosis . GranuloHaving a primary manifestation of sarcoidosis-lymphoma syndrome followed by metastasis is exceedingly rare and not well-studied in literature. While sarcoidosis is not a common disease, occurring at a rate between five to 40 cases per 100,000 people per year , the invThe approach of treating sarcoidosis-lymphoma syndrome involves therapies that actively treat both diseases. The most frequently used chemotherapy regimen against lymphoma is R-CHOP  . In the The outcome of patients with lymphoma associated with sarcoidosis compared to patients with lymphoma alone is still under study. Some studies have indicated improved rates of relapse-free survival in patients experiencing sarcoid-like reactions in conjunction with cancer diseases . HoweverWe present a case of sarcoidosis-lymphoma syndrome presenting with CNS and vertebral involvement with concomitant focal neurologic deficits. We supplement our case with a literature review that includes all previously reported cases of boney sarcoidosis-lymphoma metastasis. Multiple radiographic techniques followed by tissue biopsy may be used to reach a definitive diagnosis. Given the dramatic response to chemotherapy and corticosteroid treatment, prompt diagnosis can expedite the management of symptomatic manifestations and achieve remission.


The recently proposed concept of graphene photodetectors offers remarkable properties such as unprecedented compactness, ultrabroadband detection, and an ultrafast response speed. However, owing to the low optical absorption of pristine monolayer graphene, the intrinsically low responsivity of graphene photodetectors significantly hinders the development of practical devices. To address this issue, numerous efforts have thus far been made to enhance the light–graphene interaction using plasmonic structures. These approaches, however, can be significantly advanced by leveraging the other critical aspect of graphene photoresponsivity enhancement—electrical junction control. It has been reported that the dominant photocarrier generation mechanism in graphene is the photothermoelectric (PTE) effect. Thus, the two energy conversion mechanisms involved in the graphene photodetection process are light-to-heat and heat-to-electricity conversions. In this work, we propose a meticulously designed device architecture to simultaneously enhance the two conversion efficiencies. Specifically, a gap plasmon structure is used to absorb a major portion of the incident light to induce localized heating, and a pair of split gates is used to produce a p-n junction in graphene to augment the PTE current generation. The gap plasmon structure and the split gates are designed to share common key components so that the proposed device architecture concurrently realizes both optical and electrical enhancements. We experimentally demonstrate the dominance of the PTE effect in graphene photocurrent generation and observe a 25-fold increase in the generated photocurrent compared to the un-enhanced cases. While further photocurrent enhancement can be achieved by applying a DC bias, the proposed device concept shows vast potential for practical applications. American scientists have developed graphene photodetectors with unprecedented compactness, ultra-broadband detection, and ultrafast response speeds. In addition to being inexpensive, lightweight, and compact, graphene has unique optical and electrical properties, including a zero bandgap, ultrahigh carrier mobility, and thermal conductance that make it ideal for use in photodetectors. However, as graphene is just one monolayer, it absorbs light very weakly, thus hindering the development of practical photodetectors. A team of researchers led by Vladimir Shalaev from Purdue University in the United States has developed a plasmonic-enhanced graphene photodetector with a 25-fold increase in photocurrent generation compared with conventional graphene devices. Moreover, further enhancement can be achieved by the application of a direct current bias, opening the door for useful applications that require small devices with broad operational bandwidths and excellent responsivity. In addition to being cheap, lightweight and compact, graphene has a number of optical and electrical signatures that make it a unique photodetection material. Specifically, graphene offers (i) unlimited detectable wavelength range owing to the zero bandgap2, (ii) uniform responsivity over the entire spectrum, resulting from the invariant optical absorption (2.3%)3, and (iii) an ultrafast response speed because of the ultrahigh carrier mobility (for the photovoltaic (PV) effect)5 and thermal conductance (for the photothermoelectric (PTE) effect)9. Despite these remarkable features, the relatively low responsivity  significantly hinders practical applications of graphene photodetectors. This low responsivity is mainly owing to the weak absorption of light by single layer graphene10. Therefore, various systems have been investigated to assist light-graphene interactions and enhance the responsivity. Among them, the quantum-dot-loaded graphene phototransistor exhibits the highest responsivity gain12, but the strong gain comes at the cost of a reduced operation speed  owing to the slow quantum dot discharge process. Photonic waveguides have also been utilized to boost the responsivity; however, such structures usually have large and sophisticated device footprints because long waveguides are required to increase the photon-graphene interaction length14. A third approach to enhance the graphene photoresponsivity is to utilize plasmonic structures, which relies on the highly confined light-induced surface plasmon oscillations in metallic nanostructures to aid light absorption in graphene19. Such systems have a relatively simple device architecture and do not compromise the graphene photodetector operation speed. However, most of the proposed plasmonic-enhanced graphene photodetectors utilize only optical enhancement, whereas electrical junction control (discussed in detail later) is largely neglected. In this article, we propose a system that utilizes both optical and electrical control of a plasmonic-enhanced graphene photodetector and shows superior performance compared to previously suggested designs.Since its first successful isolation from bulk graphite, graphene has been extensively studied as a photodetection material23. In simple words, the majority of charge carriers  are driven from the hot region to the cold region, and the net charge carrier movement leads to a detectable photocurrent. Typical graphene photodetectors rely on optically induced local heating to generate a PTE current. However, intrinsic graphene sheets convert only 2.3% of incident light to heat, leaving much room for improvement. Plasmonic systems—devices that harness the optically induced unbound electron oscillations in metallic scatterers to enable nanoscale light control27—are promising candidates to generate localized heating, thereby a large T, upon optical illumination30. However, equally important in graphene photocurrent generation is the uneven electrical doping level  at the centre of the 31. Otherwise, if the doping level is uniform, then the same type of charge carrier would be driven by the 32, and uneven doping, thereby the maximum photocurrent, occurs at the metal contact edges . The PTE current in graphene is governed byW and L are the width and length of the graphene sheet, respectively, s(x) is the spatial distribution of the Seebeck coefficient (controlled by the doping type and level in graphene), Tel is the electron temperature, and R is the total resistance of graphene. To better illustrate the graphene PTE current generation mechanism, we simplify Eq. x direction) and create a series of schematic illustrations in Fig. 34. Note that both the metal contacts and common fabrication-induced contaminants p-dope graphene; thus, s(x) is positive in both the metal-contacted region and exposed region and exhibits a step owing to the difference in the doping levels. As a result, the integrand has unequal positive and negative contributions, resulting in a nonzero PTE current. Some previous works have studied the graphene PTE effect using vigorous electrical junction control without plasmonic enhancement35, thus belonging to Case 2. Here, a p-n junction is introduced at the centre of the temperature gradient, which ensures a positive contribution to the PTE current on both sides. As mentioned above, plasmonic structures help convert light into local heating (represented by high T(x) and dT/dx profiles in Fig. 18 fall into Case 3. It is evident that Case 4 with both optical heating and electrical junction enhancements results in the strongest PTE current, which forms the backbone of the design presented in this work.As reported in ref. 2O3)-graphene parallel-plate capacitor structure and deposit Al nanodisks on graphene to form a gap plasmon structure with the underlying Al2O3 and Al layers to enhance the optical absorptance. In this way, the optical heating enhancement (gap plasmon structure) and the electrical enhancement (split gates) are seamlessly combined through their shared components of the Al2O3 and Al layers. More importantly, gap plasmon structures have been shown to exhibit high optical absorptance38 and are especially efficient in light-to-heat conversion39. The choice of materials is based on two reasons: (i) it is relatively easy to tune the resonance wavelength of the Al gap plasmon structure in the visible spectrum to make colour-sensitive graphene photodetectors; (ii) the high quality of Al2O3 grown on Al guarantees robust electrical gating of graphene. In this work, we investigate the realistic optimal responsivities obtainable in graphene photodetectors that can be produced on a large scale, thus choosing to work with graphene grown by chemical vapor deposition (CVD) because of its compatibility with industry-level fabrication. Figure 2O3 layer between the nanodisks and graphene (not investigated in this work).Figure 2O3 layer are carefully designed to be 100 nm and 20 nm thick, respectively, to achieve high-optical absorptance in the visible spectrum. The split gates are defined by electron-beam lithography (EBL) with a 150 nm wide gap (taking into account the fabrication limitations), Al metallization and lift-off, followed by atomic layer deposition (ALD) growth of Al2O3. A graphene sheet grown by CVD is transferred onto the Al2O3 layer, and 30 nm thick Al nanodisks are then formed on the graphene sheet by EBL, metallization and lift-off. See the Materials and Methods section and Supplementary Information Fig. 2O3 and 100 nm thick Al) and two with nanodisks of radii R = 50 nm and R = 60 nm, and use Fig. 39, on the mesoscopic scale, the optically induced As the plasmonic structure has more stringent requirements on the layer thicknesses than electrical gating, the bottom-most Al layer and the AlR = 60 nm nanodisks, as well as the electrical connections made to the device for graphene electrical resistance (RSD) and photocurrent (IPTE) measurements. We first measure RSD while independently sweeping the voltages VG1 and VG2 on the split gates and show the results in Fig. RSD point indicates the charge neutrality point (CNP), and two orthogonal lines intersecting at the CNP can be drawn to divide the gating condition into four different regimes based on the types of carrier supplied to either side of graphene. The asymmetry in the two gating voltages at the CNP is likely owing to the trapped charges in the Al2O3 layer introduced during the fabrication processes. Next, for the IPTE measurement, a continuous-wave (CW) laser with λ = 638 nm and a power of 32 μW is focused to a spot size of ~10 μm, is modulated by a mechanical chopper at 651 Hz, and illuminates the central area of the photodetector -p+(G1) on the source side and n(G2)-p(Au) on the drain side). We calculate the average IPTE from the gap plasmon-assisted graphene photodetector by taking the average of the measured data points inside the box highlighted in Fig. R = 60 nm, which has an optical absorptance of 71% at the incident laser wavelength of 638 nm.We fabricate electrical contacts for electrical characterization under vacuum and room temperature conditions. Figure R = 60 nm  doping on the left edge and p(G1)-n(G2) doping at the centre) and lower IPTE amplitude at the edges of Fig. To compare the four cases presented in Fig. n Fig. +G doping oR = 50 nm and R = 60 nm). These measurements allow us to investigate the correlation between the optical absorptance and the IPTE responsivity. In Fig. y axis starting from 3 μA/W) indicates that the responsivity scales linearly with the optical absorptance, agreeing with our previous discussion and design principle that the optically induced VSD) can be utilized to enhance the responsivity by creating a static electric field between the two electrodes to facilitate electron harvesting. Figure VSD is swept from −2.3 to 2.3 V, from which it can be concluded that an additional sevenfold responsivity enhancement can be achieved at 2.3 V compared to zero VSD. All measurements except the one shown in Fig. VSD = 0 V.We then repeat the measurement using two additional laser wavelengths (532 and 825 nm) on three devices (no nanodisks and disks with radius 40 and (ii) improve the quality of graphene. In this work, the highest optical absorptance achieved is 71%. The optical absorptance can be improved by refining the fabrication process, for example, by introducing a thin Al2O3 layer between the nanodisks and graphene to increase the adhesion between the nanodisks and graphene. As a proof-of-concept demonstration of the device design, this work has been done with CVD graphene; however, it is well known that exfoliated graphene exhibits a stronger photoresponse, and the responsivity is expected to exhibit a significant increment if exfoliated graphene is used in combination with the proposed device design. By utilizing a similar approach, a recent work9 demonstrated an enhanced graphene photoresponse in the THz range, where a pair of split gates acted simultaneously as a gating control and a plasmonic resonator. In contrast to ref. 9, our study demonstrates enhanced performance in another technologically important wavelength range—the visible spectrum. Our study also reveals critical details of the correlation between the optical absorption (thereby heating) and graphene photoresponse.The responsivity can be further enhanced if the following two methods are implemented together with the proposed device architecture: (i) increase the optical absorptance by optimizing the plasmonic system design or implementing photonic crystals9). It can be concluded that although the absolute responsivity  of our device is not the highest, the obtained enhancement factor outperforms the other demonstrations. In Table To compare our work with the earlier reported enhanced graphene photodetectors, we list the key metrics of our work and other relevant works in Table 13, they are not suited for large-scale manufacturing owing to the limited size and yield of exfoliated graphene. Our work indicates optimal responsivities that are achievable with CVD graphene, which holds promise for mass production and commercialization. The proposed design represents a leap forward in realizing graphene’s potential in constructing ultrathin, lightweight, and ultrafast photodetectors.As the PTE effect has been shown to be the dominant mechanism of photocarrier generation in graphene, we propose a new approach to enhance the graphene photocurrent by spatially overlapping plasmon-induced optical heating and a p-n junction. We design a novel metal/dielectric/nanodisk trilayer device architecture that includes a gap plasmon structure and a pair of split gates to simultaneously realize enhanced plasmon-induced optical heating and enhanced p-n junction control, respectively. Specifically, the bottom metallic layer (with a gap in the centre) serves as the back reflector of the gap plasmon structure, as well as the electrodes of the split gates. The middle dielectric layer constitutes the optical spacer for the gap plasmon structure and the gating dielectric of the split gates to create a p-n junction. Graphene is then placed on the dielectric layer, followed by deposition of the nanodisk array. Although the nanodisks do not play a role in electrical control, they are an essential part of the gap plasmon structure and efficiently convert light into localized heating. With rigorous experiments, we have proved the dominance of the PTE effect in graphene photocurrent generation and showed that with optical heating and electrical p-n junction enhancement, the photocurrent exhibits a 25-fold increase compared to the un-enhanced case. A source-drain bias of 2.3 V can further enhance the photocurrent by sevenfold. The overall thickness of such a photodetector is 150 nm, which is much smaller than that of state-of-the-art semiconductor photodetectors, which are several microns thick. In addition, the relatively narrowband optical absorptance of the nanodisk gap plasmon structure makes it possible to control the colour sensitivity using nanodisks with different radii, eliminating the need for an additional colour filter layer when integrated into cameras. Last, we note that although photodetectors made with exfoliated graphene usually exhibit higher responsivities2) because of its low thermal conductivity to create a relatively high temperature profile on the photodetector surface under laser irradiation, which is conducive to photocurrent enhancement (see the main text). Prior to fabrication, the substrate was sonicated in toluene, acetone, and isopropyl alcohol (IPA) for 5 min each. First, alignment marks were created on the substrate using photolithography, gold (Au) metallization and lift-off. Then, the glass substrate was coated with 20 nm thick chromium (Cr) as a charge dissipation layer for the subsequent EBL step, and 200 nm thick poly(methyl methacrylate) (PMMA) was spin-coated on the Cr layer, followed by 5 min of baking on a hot plate set at 180 °C. EBL and 50 s development in methyl isobutyl ketone:IPA 1:3 was performed on the sample to define the geometry of the aluminium (Al) split gates in PMMA, leaving the underlying Cr exposed in areas that would become Al pads in the final device. Then, the sample was rinsed in Cr etchant CR-16  for 20 s to remove the exposed Cr, followed by a gentle rinse in DI water. In this step, the 150 nm wide and 30 μm long PMMA strip  was very susceptible to the CR-16 rinse time and a strong nitrogen stream; thus, after the gentle DI water rinse, the sample was left in air to dry instead of being subjected to more aggressive nitrogen gun blowing. The sample was then transferred to an electron beam evaporator for Ti (5 nm) and Al (100 nm) deposition and soaked in heated (80 °C) acetone overnight for lift-off to remove Ti/Al in the unwanted areas and define the split gates. After this, the sample was rinsed in CR-16 again to completely etch away the Cr that remained on the sample. Ti (5 nm)/Au (100 nm) electrodes were formed in contact with the Al split gates using photolithography, metallization, and lift-off. To ensure electrical contact between Au and Al, the sample was dipped in buffered oxide etch 1:6 for 5 s before the metallization step to remove the native oxide on Al. Then, 20 nm thick Al2O3 was grown on the Al split gates using ALD as the dielectric spacer/gating dielectric layer (see the main text for a description of this layer). Because Al2O3 grows preferentially on Al, the Au electrodes were not covered in continuous Al2O3 after this step, which is favourable for wire bonding during the later electrical test. Graphene was grown by CVD on copper foil41, transferred onto the sample using the wet transfer technique, and subsequently defined into smaller (100 μm × 50 μm) rectangles on the split gates using photolithography and O2 plasma etching. EBL, Ti (5 nm)/Al (30 nm) metallization, and lift-off were used again to create nanodisk arrays on the graphene sheet. During the lift-off process, some nanodisks were removed from graphene owing to the poor adhesion between Ti/Al and graphene. Finally, photolithography, Ti (5 nm)/Au (100 nm) metallization, and lift-off were used again to make the source and drain contacts to the graphene sheet. The finished sample was wire bonded to a chip carrier and placed in a vacuum chamber for characterization. See Supplementary Fig. The substrate supporting the graphene photodetectors was chosen to be 0.7 mm thick float glass  and nanodisk arrays with disk radius R = 50 nm or R = 60 nm. We did not include graphene in the optical samples, which resulted in better uniformity of the nanodisks. A variable angle spectroscopic ellipsometer  with linearly polarized incident light was used to measure the reflectance (Ref) spectra on the nanodisk arrays. As transmittance is prohibited by the optically thick Al back reflector and scattering is negligible , we calculated the absorptance spectra as Abs = 1 − Ref and show them in Fig. 2O3 layers and no nanodisks. Evidently, from Fig. During the fabrication of the graphene photodetector, we also fabricated a separate sample solely for optical absorptance characterization because the optical characterization technique (WVASE ellipsometer) requires an area of 500 μm × 500 μm of uniform nanodisks to accommodate the incident spot size. The sample consisted of universally 100 nm thick Al and AlSupplementary Information


Clostridioides (Clostridium) difficile, a pathogen of increasing concern in both health care and community settings. The recent article by J. M. Auchtung, E. C. Preisner, J. Collins, A. I. Lerma, and R. A. Britton  demonstrates an innovative approach to identify microbes that inhibit C. difficile by employing a dilution scheme to test different microbial mixtures in vitro and in vivo.The gut microbiota is an integral part of maintaining resistance against infection by  Clostridioides (Clostridium) difficile, a pathogen of increasing concern in both health care and community settings. The recent article by J. M. Auchtung, E. C. Preisner, J. Collins, A. I. Lerma, and R. A. Britton  demonstrates an innovative approach to identify microbes that inhibit C. difficile by employing a dilution scheme to test different microbial mixtures in vitro and in vivo. This type of approach can advance the identification and validation of specific microbes that elicit functions of interest for many conditions involving the microbiota, of which the complexity and variability can often complicate causality.The gut microbiota is an integral part of maintaining resistance against infection by  Clostridioides (Clostridium) difficile infection (CDI), an important health care-acquired infection. Because the use of undefined concoctions of fecal material may contain harmful bacterial, viral, fungal, and other components that influence health downstream, strategies to identify a targeted microbial population to treat CDI are of interest. However, both inherent variability in successfully used microbial communities and the ability to rapidly screen these diverse microbes have hindered these efforts. A recent study by Auchtung et al. developed an experimental platform to define bacterial components in the human microbiota that may elicit protection against C. difficile, combining in vitro and in vivo approaches to simplify these complex communities , has received particular attention due to its high rate of success in treating munities . Althoug−4 and 10−5 dilutions) were individually seeded into minibioreactor arrays, an approach that has been previously used to study microbiota functions  in the simplified communities resistant to C. difficile from 62 to 42, with each dilution composed of taxonomically diverse microbes that approximated their donor origin. The investigators then chose a subset of microbial mixtures to test their abilities to inhibit C. difficile in a mouse model of disease. Mice with an established “humanized” microbiota  continued to restrict C. difficile expansion. Interestingly, the majority of the organisms in these samples were classified as Clostridiales. However, microbial recovery in animals with CDI that were treated with simplified communities was not restricted to organisms found in the input; in fact, OTU tracking suggested that OTUs present in the mouse prior to antibiotic treatment were also significantly enriched. These included OTUs belonging to multiple phyla, such as Bacteroides, Parabacteroides, Erysipelotrichaceae, Bifidobacterium, and Porphyromonadaceae OTUs.Auchtung et al. first applied a dilution scheme to six fecal samples collected from healthy human participants to generate multiple simplified microbial communities. Multiple diluted communities (at 10unctions . Minibiocrobiota  were preC. difficile and (ii) microbes introduced to the system are only part of the recovery process. Much of the focus of CDI therapeutics has focused on identifying microbes that provide functions known to target C. difficile itself, such as the production of secondary bile acids that inhibit C. difficile growth  a diverse set of microbes is likely able to inhibit e growth . Other gridiales , 6. Yet  in mice . Notably studies , 9. How in vitro and in vivo approaches to screen simplified communities for a particular output is efficient and easily adapted for other uses. In vitro prescreening of defined microbiota mixtures reduces the number of animals necessary for testing multiple combinations of microbes. The approach is also highly applicable for the identification of microbial communities important in other conditions where the microbiota is assumed to be involved. Minibioreactors for identification, screening, and validation of defined microbial populations could easily be modified to look for specific output, such as production of specific metabolites under different conditions or the impact of environmental disruptions on the community function. Indeed, a logical inclusion to this study would have been to use the bioreactor system to identify whether metabolites known to impact C. difficile were produced by the simplified communities. This additional measurement may have identified shared functions of seemingly diverse microbial mixtures that influence C. difficile physiology, as well as provide some context for how well these functions are recapitulated in vivo.Cultivation of microbes of interest remains an obstacle to development of targeted microbial therapeutics, for CDI and otherwise. The methodology employed by the authors provides a potential solution to isolation, screening, and validation of complex microbial communities, which are often laborious. While this study is not the first to use a dilution/extinction strategy to simplify communities  or bioreIn summary, Auchtung et al. demonstrate a novel approach to identify distinct microbes of interest. As interest in the development of microbial therapeutics to treat disease and maintain health continues, efficient systems as described in that study can advance the process of understanding these complex microbial communities.


In this study, a computational procedure for the investigation of the vibration behavior of laminated composite structures, including graphene inclusions in the matrix, is developed. Concerning the size-dependent behavior of graphene, its mechanical properties are derived using nanoscopic empiric equations. Using the appropriate Halpin-Tsai models, the equivalent elastic constants of the graphene reinforced matrix are obtained. Then, the orthotropic mechanical properties of a composite lamina of carbon fibers and hybrid matrix can be evaluated. Considering a specific stacking sequence and various geometric configurations, carbon fiber-graphene-reinforced hybrid composite plates are modeled using conventional finite element techniques. Applying simply support or clamped boundary conditions, the vibrational behavior of the composite structures are finally extracted. Specifically, the modes of vibration for every configuration are derived, as well as the effect of graphene inclusions in the natural frequencies, is calculated. The higher the volume fraction of graphene in the matrix, the higher the natural frequency for every mode. Comparisons with other methods, where it is possible, are performed for the validation of the proposed method. Composites are made up of two or more constituent materials that, when combined, generate a material with physical and chemical characteristics different from the individual components. Composite structures have presented outstanding advances in the last decades. The recent applications of fiber-reinforced composite structures to marine , civil , aerospaGraphene is a carbon allotrope, the thinnest known material, i.e., one carbon atom thick, which additionally is exceptionally strong—almost 200 times stronger than steel ,8,9. FurThe fiber and matrix-dominant behavior of fiber-based polymer composites are crucial in many mechanical, aerospace, or structural applications. Pre-mixing the polymer matrix with nanoparticles could enhance the through-thickness or matrix-dominant properties. Rafiee et al.  employedAlthough some works have already been done on vibrations of composite structures reinforced by nanoparticles, there are only a few works, which focused on vibration behavior of carbon fiber-based laminate composites with pure graphene inclusions. Hulun et al.  have invIn the present paper, a computational approach is proposed for the estimation of vibration characteristics of carbon fiber laminate composite plates with graphene inclusions. The method firstly computes the size-dependent mechanical properties of graphene used in the composite. In the second phase, the orthotopic properties of the hybrid matrix are calculated adopting Halpin-Tsai models for specific volume fractions of graphene in the matrix. Knowing the elastic constants of hybrid matrix, the elastic mechanical properties of the composite lamina can be evaluated. In the next step, finite element models are developed for various configurations of laminated composite plates using conventional shell elements. Applying different boundary conditions and solving the free vibration problem, modes of vibration and corresponding natural frequencies are finally extracted. The effect of graphene volume fraction on vibration characteristics of various composite plates is determined. To the authors’ best knowledge, it is the first time where this holistic and relatively simple approach (four-stage technique), taking into account the size-dependent behavior of graphene inclusions, is proposed for the vibration analysis of graphene-carbon fiber-reinforced composite structures.The elastic mechanical behaviour of different-sized graphene can be numerically examined and predicted using a spring-based finite element approach ,33. AccoThe Young’s modulus in TPa of the graphene can be predicted using the following rational function (1)Egr Halpin-Tsai model for randomly oriented discontinuous rectangular reinforcements is utilized to compute the Young’s modulus of the hybrid graphene/polymer matrix. According to this model, the Young’s modulus of the graphene/polymer matrix can be predicted by the following equation (2)Em−grAssuming that Poisson’s ratio Consequently, the shear modulus of the hybrid matrix exhibiting quasi-isotropic behaviour may be evaluated from the next equationConsidering the inertia effect for the dynamic problem, the equivalent mass density of the hybrid matrix can be determined using rule of mixtures as1, and Poisson’s ratio, υ12 can be computed by employing the standard rule of mixture s, respectively. The model has been tested for its convergence in terms of mesh density and a mesh with a size of 0.5 mm for each element is finally chosen.According to the ASTM D7264 standard, K) and the global mass matrix (M), assembled from the elemental matrices using conventional finite element procedures and considering the undamped free vibrations of the composite plate, the equation of motion can be assembled asd is the assembled displacement vector. By applying the boundary conditions on the composite plate, the eigenvalue problem can be solved using common finite element procedures, which reveal the natural frequencies and corresponding mode shapes of vibration.The hybrid composite plates of these characteristics, as well as different carbon nanostructure inclusion types and volume fractions, have been successfully validated  for bendIn this work, polyester resin, graphene, and carbon fiber were selected as matrix material, nano inclusion and reinforcement, respectively. Physical properties of the components constituting the hybrid composite material are presented in E1, E2, G12, G23, as well as cρ increase as the volume fraction of graphene increases. Specifically, there is an 34.6%, 542%, 533%, and 686% increase in E1, E2, G12, and G23 with the addition of 50 vol.% graphene, respectively. Simultaneously, there is only 13.6% increase in the mass density of the lamina due to the presence of graphene since it is denser than polyester resin.Given the physical properties of the components, the physical properties of graphene-added unidirectional carbon fiber-reinforced lamina are evaluated theoretically, based on the proposed method, and the outcome is provided in a,b), where a and b correspond to the number of ridges or valleys existing in the mode at longitudinal and transverse direction of the plate. Note that a,b) exists in the SSSS case as well. The difference in the shape is mainly on the boundaries, where the rotation of the degrees of freedom are free and fixed in SSSS and CCCC boundary condition, respectively. The structure of the first three (basic) modes of vibration depends on the plate geometric and stiffness characteristics. In general, the presence of graphene into the composite seems not to influence the shape of the vibration modes; however, it affects their sequence.A numerical calculation of the natural frequencies and mode shapes of vibration can be carried out for a composite plate, according to the procedure described in the previous section for different boundary conditions. Here, we assume two types of supports, (a) the longitudinal and transversal edges of the rectangular plate are clamped, CCCC (clamped—clamped—clamped—clamped), and (b) the longitudinal and transversal edges of the plate are simply supported SSSS (simple—simple—simple—simple). f0, of the composite plate without the presence of graphene considering various configurations. Specifically, the width remains constant w = 25 mm, while the length is l = 25, 30, 35, 45, 85, 145, 245 mm. grV = 0, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, and 0.50. In order to study the effects of graphene inclusion on vibration behavior of laminated composite plates under CCCC boundary conditions, various values of volume fraction of graphene are studied. Specifically, eleven different cases are considered, i.e., In order to study the effects of graphene inclusion on vibration behavior of laminated composite plates under SSSS boundary conditions, various values of volume fraction of graphene are considered.grV = 0, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, and 0.50. Once again, 11 different cases are considered, i.e., In the previous cases (SSSS and CCCC), the behavior of the normalized frequency of various vibration mode versus the graphene volume fraction has been depicted concerning different L/w ratio. It is observed that the slope of this curve changes with different L/w ratio, and the trend is also different for the different vibration mode. The effect is more obvious in lower order than higher order modes. This phenomenon may be explained by the variation of the stiffness and mass (density) characteristics of the structure due to the presence of graphene that differs from each other . NeverthgrV greater than zero, a linear function can be used, i.e.,c is the slope, and d is the intercept. In the CCCC case, c = 1.4164 and d = 1.0745 with R2 = 0.9848. In the SSSS case, c = 1.1797 and d = 1.0533 with R2 = 0.9885.In order to estimate the average effect of graphene on the natural frequencies of the composite plate, the mean value of the normalized frequency is calculated for every graphene volume fraction considering all modes shape of vibration. The presence of graphene enhanced considerably the orthotropic mechanical properties of the polymer composite lamina;The presence of graphene into the composite does not influence the shape of the vibration modes, however it affects their sequence;The presence of graphene into the composite increase significantly natural frequencies of the structure;The presence of graphene into the composite increase slightly more the normalized frequency of higher order than basic modes;The presence of graphene into the composite increase more natural frequencies of CCCC than SSSS boundary condition.A multi-scale procedure has been applied in the investigation of the vibration behavior of laminated composite plates reinforced by carbon fibers and graphene. According to analysis results, the following important general conclusions have been drawn:The dispersion of graphene particles in a polymer matrix is a big challenge, and there exists a practical restriction on the addition of graphene above a certain level (maximum of 10 wt.%), owing to the development of agglomerates . Here, wFuture work concerns the attempt of introduction of a correction in the present computational approach considering the non-uniform distribution of nanoparticles in the polymer matrix.