In recent years, graphene has found its use in numerous industrial applications due to its unique properties. While its impermeable and conductive nature can replace currently used anticorrosive toxic pigments in coating systems, due to its large strength to weight ratio, graphene can be an important component as a next-generation additive for automotive, aerospace and construction applications. The current bottlenecks in using graphene and graphene oxide and other two-dimensional materials are the availability of cost-effective, high-quality materials and their effective incorporation  into the product matrices. On overcoming these factors, graphene may attract significant demands in terms of volume consumption. Graphene can be produced on industrial scales and through cost-effective top-down routes such as chemical, electrochemical and/or high-pressure mechanical exfoliation. Graphene, depending on end applications, can be chemically tuned and modified via functionalization so that easy incorporation into product matrices is possible. This paper discusses different production methods and their impact on the quality of graphene produced in terms of energy input. Graphene with an average thickness below five layers was produced by both methods with varied defects. However, a higher yield of graphene with a lower number of layers was produced via the high-pressure exfoliation route.This article is part of a discussion meeting issue ‘A cracking approach to inventing new tough materials: fracture stranger than friction’. Durin lattice  and ther lattice , and dem lattice , coverin lattice ,9, gas a lattice ,11, fiel lattice , transpa lattice , coating lattice ,14 and p lattice ,16. Howe lattice . Thus, i(a)In general, the synthesis methods consist of two main categories : bottom-(b)a). During the sonication process, bubbles generated by the ultrasound grow and then collapse generating cavitation's, which in turn give rise to shear forces (figure 1b). Still, when more bubbles are formed on the lateral side, the shear force controls the separation process [One of the most classic categories of this approach is the physical exfoliation (PE) of graphite, which includes the mechanical ‘scotch-tape’ exfoliation . While tfigure 1 process . By cont process . Both of process ,29 and t process . Figure Earlier studies focused on the chemical exfoliation (CE) of graphite ,2, but ta); the mechanism can be described by a three-step ‘intercalation–expansion–exfoliation’ process; OH− created by water reduction attacks the edge sites, expands the graphite layers and allows sulfate ions to intercalate; then the reduction of sulfate ions releases gas to further separate layers. Figure 3b demonstrates a typical EE process using sulfate salts solution as electrolyte [Due to their considerable merits, electrochemical exfoliation  approachfigure 3ctrolyte .Figure There remain major challenges to the commercialization of graphene, such as the quality and yield of the produced graphene. As a result, exfoliation methods and related process parameters urgently need to be further optimized to achieve a low-cost and scalable production.(c)In a broader sense, cracking in solid materials is seen as a process that imparts a negative impact on material properties. However, understanding how the mechanism and energy transition of relevant cracking processes affect layered materials is paramount to achieving reduced energy usage, optimum product yield and process efficiency for successful commercial two-dimensional materials production. This is because the highest cost contribution of the top-down routes comes from energy usage.(i)the exfoliation energy is equal to the difference between the ground-state energy of the bulk per layer and that of an isolated layer’. Assuming only van der Waals interactions between layers, the team has deduced the exfoliation energy for several materials . The underlying principles were extended to the materials with interactions such as hydrogen bonds.The internal energy of the system in the context of exfoliation is dominated by the interlayer interaction, and it is suggested that theoretically, the exfoliation energy is defined as the energy required to peel off a single layer from the surface of the bulk materials or to separate all the layers of the bulk and divide the number of layers. One research group  has simp(ii)However, knowing the energy required to overcome interlayer interaction is only a part of the story. The energy applied into the system is used for two different types of cracking, interlayer cracking, otherwise known as exfoliation, and fragmentation, which leads to a reduction in lateral particle size. Fragmentation has double-faced tactics. On the one hand, it can reduce the lateral size of graphene. This is not desirable for achieving large-area graphene. On the other hand, it facilitates exfoliation because smaller graphite flakes are easier to exfoliate than larger ones because of smaller collective van der Waals interaction forces between the layers in smaller graphite flakes.The type and extent of the forces exerted during the exfoliation determine which process will be effective and efficient. Various forms of forces and energy transfers can occur in the system, depending on the process of choice. For example, sonication generates cavitation and micro bubble explosions, and as a result, compressive forces and normal tensile forces work against each other to slip layers over each other. On the other hand, in the high shear exfoliation process, it is the shock waves, random collisions and flow channels that lead to shear forces that help the layer exfoliation and fragmentations.(iii)et al. [Once exfoliated, isolated two-dimensional layers should be stabilized against re-aggregation. Stability of the two-dimensional dispersions is typically enforced by introducing dispersing agents, such as surfactant molecules and polymers, to generate new forces such as π–π conjugation, hydrophobic force and Coulomb attraction and match the surface energy of graphene layers to that of the exfoliation media . The orget al. , becauseet al. .(iv)m), the energy required to separate all molecules (solvent/graphene sheet) to infinity (DHα) and the energy to bring them back together in the form of a solvent-graphite dispersion (DHo), but with flakes of different thickness [m), should compensate for the difference between the (DHα) and (DHo).The underlying scientific principle of the energy distribution of graphite/graphene dispersion is similar to the Griffith Theory of Crack propagation. To keep the new reality in check, a reduction in potential energy from the old state should be greater than or equal to an increase in surface energy due to the creation of a new state. Energy terms pertaining to a graphene dispersion can be defined as the enthalpy of mixing for graphite in the solvent (DHhickness . The ene. 2(a)Electrochemical treatment resulting in expanded graphite. An electrochemical cell with two electrodes is used to exfoliate high purity compressed graphite pellets (HQ graphene). The graphite anode and platinum gauge cathode were mounted using copper crocodile clips and immersed completely in the aqueous electrolyte, which was 0.5 M ammonium thiosulphate, pH adjusted with alkaline media to 8–9. A voltage of 8 V was applied, and the graphite was allowed to expand for 1 h (a). Further details on the reaction mechanism can be found in Achee et al. [ for 1 h a. Furthee et al. .Intercalation by soaking in intercalant solution. Intercalant (2% tetrabutylammonium sulfate) was added to the resultant expanded graphite dispersion (5 mg ml−1) for a few days. The mixture was subjected to bath sonication for 30 min to get a homogeneous solution. After soaking for 5 days, the solution was then sprayed (Graco Magnum 262805 X7 HiBoy Cart Airless Paint Sprayer) into a container at a high-pressure of 2000 psi. This cycle was repeated three times. The solution was then subjected to bath sonication (30 min) and centrifugation (10 000 r.p.m. for 30 min). The supernatant (containing the few-layer graphene) was separated for further processing (b). Further details are described in Nemala et al. [ocessing b. Furthea et al. .Synthesis: Exfoliation of graphite into few-layer graphene (FLG) was achieved through a number of consecutive steps.Characterization. Several characterization techniques were used to assess the quality of graphene produced.X-ray diffraction (XRD). X-ray diffractograms were collected on a Bruker D2 phaser. High purity (99.999%) Ceylon vein graphite was micronized and deposited on an XRD sample holder. Measurements were taken at 22°C and 2θ between 10° and 70°.Raman spectroscopy. The Raman spectroscopy of the exfoliated samples was carried out using Lab Raman, Jobin Vyon spectrometer: model HR800 using Argon laser of wavelength 514.5 nm. The sample preparation was done by spreading the exfoliated aqueous solution uniformly over a glass substrate and then positioning it below the infrared (IR) lamp for 10 min. A particular area of the sample was then selected and focused on the laser beam.Scanning electron microscopy (SEM). SEM images were recorded using an LEO Gemini 1525 FEG SEM using a 30 µm aperture and operated at 5 kV. Aliquots of 10 µl of the electrochemically exfoliated and pressure exfoliated inks were drop casted onto an ozone-treated silicon wafer and dried.Transmission electron microscopy (TEM). High-resolution transmission electron microscopy (HR-TEM) images were recorded using an JOEL JEM 2100 F field emission gun-transmission electron microscope operated at 200 kV. The sample preparation was carried out by ultrasonication of the aqueous solution in water for about an hour. The homogeneous dispersion of the sample was then drop casted onto a carbon lacey grid for about 2 h before imaging.X-ray photoelectron spectroscopy (XPS). XPS data were obtained using an AXIS Supra instrument from Kratos Analytical having Al Kα source (hν = 1486.6 eV) in the range of 1–1000 eV to investigate the surface chemical composition of the exfoliated graphene sample. The XPS data fitting and analysis was carried out using the software ESCApe.. 3High purity (99.999%) Ceylon vein graphite was used to produce graphene in this study. An X-ray diffractogram  was useda,b [Figure 6a shows the Raman spectra of the high-pressure exfoliated graphene, which consists of D band, G band and two-dimensional band related to various vibrational modes. The G band comes from in-plane vibrational mode of sp2 carbon atoms associated with the E2 g phonon. The D band is associated with the breathing mode of A1 g symmetry of sp2-hybridized carbon rings. This D band corresponds to the defects present in the graphene sheet. The two-dimensional band arises due to the second-order Raman scattering process, which signals at double the frequency of the D band [The quality of samples was studied using Raman spectroscopy and is compared with graphite shown in figure 6a,b . Figure e D band ,42. In ne D band , are tabThe Raman spectra clearly showed the difference between the two-dimensional peaks obtained from the two exfoliation routes. The two-dimensional band of high-pressure exfoliated graphene is symmetric in shape, whereas multiple peaks are visible in the two-dimensional band of electrochemically exfoliated graphene. The low D/G intensity ratio for the high-pressure exfoliated sample as compared to the electrochemically exfoliated material is an indication of low defect concentrations in graphene produced. The symmetric shape and the position of the two-dimensional peak reveal that fewer layers of graphene are produced by high-pressure exfoliation.a) than electrochemical exfoliation (b). Follow up morphological investigations by the TEM study revealed the presence of graphene sheets, as shown in figures 8b and 9b. Compared to patterns in 8b, the hexagon is more defined in figure 9b, indicating that the high-pressure exfoliation further reduced the number of layers in the flakes. The magnified image in figure 9c confirms that the flakes contain only 1–2 layers of graphene. The TEM images and spot patterns of the selected area diffraction and HR-TEM images of the high-pressure exfoliated graphene shown in Scanning electron micrographs indicate that graphene obtained through the pressure exfoliation route achieved higher concentrations a than eloliation b. FollowThe XPS survey spectra conducted on the high-pressure exfoliated graphene sample is shown in . 4We have investigated the quality of graphene produced by a novel production method combining electrochemical exfoliation and high-pressure shear exfoliation, in aqueous media using characterization techniques; Raman spectroscopy and HR-TEM. Our results show that the proposed method produces a high yield of few layer graphene flakes with less than five atomic layers. The electrochemical exfoliation process does not introduce notable defects or additional oxidation in the graphene sheets, whereas high pressure creates minor defects. The main advantages of this method are its high efficiency and the controlled quality of exfoliated graphene sheets with a high yield of FLG obtained. We explored the impact of type, energy input and mechanisms involved with different exfoliation processes. We describe various factors that can influence the choice of the exfoliation process. This work strengthens the field of liquid phase exfoliation and bridges the gap between electrochemical and mechanical exfoliation proposing a low-cost, highly efficient process for large-scale production of high quality few layers graphene.


Shigella flexneri which poses a serious threat to human health. In the current study, X-ray photoelectron spectrometer (XPS), Fourier transform infrared (FTIR), field-emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HR-TEM) and thermal gravimetric analysis (TGA) were used to characterize the properties of composited Bacitracin-AgNCs. Furthermore, the inhibitory effects of Bacitracin-AgNCs against S. flexneri were explored, and the inhibition mechanism was discussed in terms of its aspects of cell membrane ravage, ATPase activity decline and biofilm inhibition. The results reveal that the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Bacitracin-AgNCs against S. flexneri were 0.03 mg/mL and 4 mg/mL. Bacitracin-AgNCs may cause irreversible impairment to cells and greatly change the cell morphology. The cell membrane integrity of S. flexneri was destroyed with changes in the characteristics of membrane permeability and intracellular substances leakage. Moreover, our study further proved that Bacitracin-AgNCs significantly inhibited the formation of S. flexneri biofilms and reduced the number of viable bacteria in biofilm. These findings provide a potential method for the exploitation of organic composite nanomaterials as a novel antimicrobial agent and its application in the food industry.A novel nanomaterial Bacitracin-Ag Nanoclusters (Bacitracin-AgNCs) was formed to achieve a better antibacterial effect on  Shigella spp. are facultatively anaerobic, nonsporing and atrichous gram-negative short rod-shaped pathogenic bacteria, which can cause different degrees of dysentery [Shigella flexneri, Shigella sonnei, Shigella boydii and Shigella dysenteriae. Shigella flexneri is one of the uppermost pathogens causing foodborne bacterial infections. Related studies have found that S. flexneri has been detected in the food industry, including in meat products, dairy products and some markets and workshops [S. flexneri has a stable biofilm structure, which is a bacterial aggregation of extracellular polymeric substances (EPS) composed of polysaccharides, proteins, DNA and lipids [Shigella is antibiotic therapy. However, the therapeutics of bacterial infections becomes more difficult with the emergence of resistant strains and biofilms. Therefore, it is of great significance to develop new and effective methods to destroy the biofilm integrity and prevent the growth of S. flexneri.ysentery . The genorkshops ,3. S. fld lipids . The bioCurrently, the treatment of bacterial infections based on nanomaterial antimicrobial agents has become a research hotspot. Recently, metal nanoclusters have attracted increasing attention in the field of biomedical science due to their unique physical and chemical properties, such as high surface-to-volume ratio, strong fluorescence and discrete energy levels . At the Generally, metal nanoparticles can be synthesized by various chemical and physical methods. However, the materials used in these chemical methods, such as organic reagents and stabilizers, as well as radiometry in physical methods, have obvious flaws in particle aggregations and environmental harm . It is aBacillus subtilis and Bacillus licheniformis. The bacitracin can self-assemble into larger molecules, thus better binding with metal ions and further forming unique morphology in the process of co-cultivation with metal salt solution [Bacitracin, with the characteristics of water solubility, low-toxicity, and heat stability, is a polypeptide antibiotic extracted from solution . As a kisolution . Silver solution . AdditioS. flexneri are poorly researched. Hereby, we chose bacitracin as an embedding agent to develop a water-soluble nanomaterial via encapsulating silver ions and characterized the properties of the material. The composite nanomaterial showed strong antimicrobial action on S. flexneri. Moreover, we depicted the inhibition effects of Bacitracin-AgNCs on the biofilm formation of S. flexneri, clarifying the inhibitory mechanisms of the nanomaterial on S. flexneri.Nevertheless, little report has been made on the synthesis of composite silver nanomaterials with the combination of the bacitracin template and silver ions, and the antibacterial effects as well as the mechanisms of synthetic nanomaterials against S. flexneri ATCC 12022 was obtained from the Food Safety and Hygiene Laboratory . Before each experiment, the S. flexneri strains were shake-cultured in Luria–Bertani (LB) broth for 18 h at 37 °C.Bacitracin was obtained from BidePharm Technology Co., Ltd. , and levofloxacin (LFX) was purchased from JingBo Biotechnology Co., Ltd. . All other chemicals were of analytical grade. 3 (17 mM) to synthesize Bacitracin-AgNCs. Then, 200 µL NaOH (1 M) and 20 µL NaBH4 (2 mM) were introduced to adjust the alkaline conditions (pH = 12) and enhance stability, respectively, and the mixture was incubated at 37 °C for 3.5 h. The sample was collected by centrifugation  and the supernatant was filtered by the membrane of 0.22 μm. Then, the nanoclusters were obtained by dialysis (cut-off of 300 MWCO) in deionized water for 24 h. Finally, the nanoclusters powder was acquired by lyophilization and stored in a vacuum dryer for subsequent use.The synthesis of Bacitracin-AgNCs was performed according to a method described previously  with cerFor the characterization of Bacitracin-AgNCs, we firstly used UV300 UV-VIS spectrophotometer  to record the absorbance of the nanoclusters, the solution was properly diluted with distilled water before measurement. A fluorescence spectrophotometer  was used to identify the fluorescence properties. Elemental and functional groups of Bacitracin-AgNCs were analyzed by ESCALAB Xi+ X-ray photoelectron spectrometer (XPS)  and Fourier transform infrared spectrometer (FTIR) . The surface structures of Bacitracin-AgNCs and bacitracin were observed using SU-8020 field-emission scanning electron microscopy (FESEM) , the microcrystalline powders of two samples were fixed on the conductive adhesive of the sample table and sprayed with gold for 10 s for observation. High resolution transmission electron microscopy (HR-TEM)  and a dynamic light scattering (DLS) instrument  were used to observe the morphology and measure the particle size of the nanoclusters. Thermal gravimetric analysis (TGA) was performed by Q600 Thermo analyzer Systems  to determine thermal stability of Bacitracin-AgNCs in the condition of heating the samples from 25 to 600 °C at a heating rate of 10 °C/min in a nitrogen atmosphere.S. flexneri, we performed the turbidity experiment in LB liquid medium according to a previous research method [S. flexneri in a logarithmic growth phase was respectively added to LB broth containing Bacitracin-AgNCs, bacitracin and LFX , and the mixed solution was shake-cultured at 37 °C for 16 h. The LB broth without drugs treatment served as blank control. Finally, the optical density of the corresponding bacterial suspension at 600 nm (OD600) was measured at 0 and 16 h.In order to visually observe the antibacterial activity of Bacitracin-AgNCs against h method . S. flexS. flexneri in a logarithmic growth phase (approximately 107 CFU/mL) was inoculated into every tube and cultured at 37 °C for 24 h under shaking conditions (160 rpm). MIC value was the lowest concentration of Bacitracin-AgNCs solution without t visible bacterial growth in LB broth. The cells prepared in the test tubes were dispersed on Salmonella Shigella agar (SS) plates, and the MBC value was regarded as the lowest concentration of Bacitracin-AgNCs solution, where there were no visible bacterial colonies on the surface of SS agar plates.Stock solution of Bacitracin-AgNCs at the concentrations of 16 mg/mL was diluted into 10 tubes containing sterile LB Broth to make the concentrations from 0.016 to 8 mg/mL. Then, S. flexneri in logarithmic growth phase (approximately 107 CFU/mL) was inoculated into each LB broth and the mixture was incubated at 37 °C and 160 rpm for 24 h. The growth of bacteria was recorded by a Thermo Scientific Multiskan Spectrum  at 600 nm at 2 h intervals.The powder of Bacitracin-AgNCs was dissolved in sterile LB broths to acquire the final concentrations of 1/16 MIC, 1/8 MIC, 1/4 MIC, 1/2 MIC, and MIC. LB without Bacitracin-AgNCs was used as a control. LFX and bacitracin solution prepared with the same concentration of MIC were used as positive controls. Then, S. flexneri in a logarithmic growth phase (approximately 107 CFU/mL). The mixtures were incubated at 37 °C for 8 h under 180 rpm. 1 mL suspension was absorbed from the mixtures every hour and centrifuged at 8000 rpm for 5 min, and the absorbance of supernatant was measured at 260 nm by a UV-VIS spectrophotometer .Cell integrity was examined by determining the leakage of cell constituents according to previously published methods ,18, withS. flexneri cells was determined by measuring the release of β-galactosidase activity into the culture medium with ONPG as a substrate [S. flexneri grown to logarithmic phase in LB medium containing 2% lactose was collected by centrifugation at 8000 rpm for 10 min, washed three times and resuspended (to give 107 CFU/mL) in sterile PBS. Then, Bacitracin-AgNCs , 1/4 MIC, 1/2 MIC, MIC, MBC) was added into the S. flexneri suspensions. After 8 h of incubation at 37 °C, the solution was centrifuged at 8000 rpm for 5 min, and o-nitrophenyl-β-D-galactopyranoside  was added to the supernatant. The mixture was incubated at 37 °C for 30 min. The cell membrane permeability was determined at 420 nm by a UV-VIS spectrophotometer  every hour.The cell membrane permeability of ubstrate . S. flexS. flexneri suspension in logarithmic growth phase (about 107 CFU/mL) was centrifuged, the supernatant was removed and the obtained cells were resuspended with sterile PBS. Then, the S. flexneri suspension was cultured with Bacitracin-AgNCs at MIC and MBC for 6 h at 37 °C, and the inoculum without antimicrobial agents as a control. After treatment, the bacteria cells were washed twice with sterile PBS and suspended again. Subsequently, 100 μL of cell suspension was dropped onto a slide glass, also, 5 μL of acridine orange (AO) and 5 μL of ethidium bromide (EB) were added into the cell suspension. After blowing gently and blending the solution, the slide was covered and the cells were stained at room temperature for 2 min. Samples were observed by a confocal laser scanning microscope (CLSM) .To detect bacterial viability and membrane integrity, the living/dead staining of bacterial cells was performed as described in a previous study with slight modifications . S. flexS. flexneri cells in logarithmic growth phase (approximately 107 CFU/mL) were collected and treated with Bacitracin-AgNCs , MIC, MBC) at 37 °C for 0.5–2 h. Subsequently, the effects of Bacitracin-AgNCs on Na+ K+- and Ca2+ Mg2+-ATPase activity of S. flexneri were determined by an ATPase assay kit .The S. flexneri cells were treated with Bacitracin-AgNCs (0 (control), MIC, MBC) and incubated at 37 °C for 6 h. Part of the culture medium was poured out and centrifuged (5000 rpm) at 4 °C for 10 min to obtain cell aggregates. The harvested cells were rinsed three times with sterile PBS and fixed in 2.5% glutaraldehyde for 6 h at 4 °C to maintain cell aggregation. Then, the samples were dehydrated in gradient ethanol  for 10 min. The dehydrated samples were sprayed with gold and tested under an FESEM .S. flexneri (approximately 107 CFU/mL) were added to a 96-well polystyrene microtiter plate and incubated at 37 °C for 24 h under static conditions. After biofilm formation, the suspension was gently removed and the 100 μL of sterile PBS (0.01 M) was used to remove planktonic bacteria. The samples were fixed with methanol for 15 min and then stained with 200 μL of 1% crystal violet solution at 37 °C for 15 min in a dark environment. Finally, the stained biofilms were dissolved in 200 μL of 95% ethanol. The OD values at 570 nm were obtained by a Thermo Scientific Multiskan Spectrum. The following formula was used to calculate the percentage of biofilm formation inhibition:The formation of biofilm was quantitatively determined in 96-well polystyrene plates  with crystal violet staining method introduced by , with soS. flexneri suspension (approximately 107 CFU/mL) was incubated in 1/8 LB broth with Bacitracin-AgNCs (0 (control), 1/16 MIC, 1/8 MIC, 1/4 MIC, 1/2 MIC, MIC), LFX and bacitracin to form biofilms on glass coverslips (4 mm × 4 mm) in a 24-well polystyrene microtiter plate for 48 h at 37 °C. After biofilm formation, the samples were fixed in fixative  for 6 h at 4 °C, then washed with PBS and dehydrated with a series of ethanol concentrations  for 10 min. Finally, the dehydrated specimens were coated with gold and observed by an ESEM  [OR, USA) .p < 0.05 was considered statistically significant.All experiments were performed in triplicate, and the data were indicated as arithmetic mean ± standard deviation. Statistical analysis was performed using SPSS software . One-way analysis of variance (ANOVA) was used to calculate the significant differences. 4. In this process, bacitracin as an entrapment agent can cover different surfaces and connect inorganic molecules with biological molecules. Therefore, bacitracin embeds silver atoms and couples to form a new nano antibacterial agent under synthetic conditions.Bacitracin is a cyclic peptide, consisting of 12 amino acid residues A, which The UV-VIS spectra and fluorescence spectroscopy of Bacitracin-AgNCs are shown in −1 was the result of characteristic absorption of the O–H stretching vibration, while the peak at 1658 cm−1 was C=O stretching vibration, indicating that carboxylic groups existed in synthesized nanoclusters. Meanwhile, the characteristic absorption of 2964 cm−1 revealed the N–H stretching vibration [2 carbons , sp3 carbons  and carbonyl carbons , respectively [2. The above FTIR and XPS results suggested that Bacitracin-AgNCs involved π-conjugated and oxidation domains, as well as amorphous regions at the same time [We use FTIR and XPS to analyze the functional groups and components of the Bacitracin-AgNCs in detail. Firstly, the surface groups of synthesized Bacitracin-AgNCs were examined by FTIR A. Brieflibration ,26. X-raectively . The N 1ons C=C, 4.8 eV, same time .The surface structures of nanoclusters were observed by field-emission scanning electron microscopy (FESEM). It could be seen that bacitracin had a relatively dense structure A, while Examination of the thermal stability of Bacitracin-AgNCs was carried out by a TGA instrument and the result is shown in onset) of bacitracin (168.61 °C) was higher than that of Bacitracin-AgNCs (155.89 °C). This phenomenon might be due to the fact that the silver clusters began to degrade with increasing temperature, which made the integral Bacitracin-AgNCs degrade before the solitary bacitracin. According to the TG curves, the temperature values at the maximum decomposition rate (Tmax) of bacitracin and Bacitracin-AgNCs were 345.16 and 319.71 °C, respectively, demonstrating that the thermal stability of bacitracin was superior to that of Bacitracin-AgNCs at relatively low temperature; something that could be induced by the looser surface network structures of Bacitracin-AgNCs observed in FESEM images (In the degeneration stage , the iniM images A,B. Mean600 value of control group without antibacterial agents increased significantly after culturing for 16 h, while the OD value of the bacitracin group increased slightly, indicating that bacitracin had a certain inhibitory effect on S. flexneri. By contrast, the OD values of the Bacitracin-AgNCs group and LFX group basically remained unchanged after 16 h culturing. The results reveal that Bacitracin-AgNCs had a similar antibacterial function to antibiotics LFX, and the antibacterial effect of Bacitracin-AgNCs was stronger than that of bacitracin alone.The result in S. flexneri were 0.031 and 4 mg/mL, respectively. The growth curves of S. flexneri treated with Bacitracin-AgNCs are shown in As shown in The membrane was destroyed and the intracellular components were released after bacterial membrane was exposed to antibacterial agents. Therefore, the membrane integrity could be well determined by measuring the OD values at 260 nm of supernatant. In S. flexneri for 8 h, the absorbance values of cells at 420 nm increased significantly (o-nitrophenol production of the control group remained at a low level. From the result, Bacitracin-AgNCs increased the membrane permeability of S. flexneri, resulting in the leakage of key cellular enzymes.After treatments of different concentrations of Bacitracin-AgNCs on ficantly D, while S. flexneri cells are shown in S. flexneri cells exhibited uniform green fluorescence, almost no red fluorescence was observed, indicating that unprocessed cells confined in a complete normal condition. When the cells were exposed to Bacitracin-AgNCs at MIC, the green fluorescence decreased while the red fluorescence increased, demonstrating the membrane permeability of the treated group was reinforced compared with the control. A large amount of red fluorescence was found of S. flexneri cells treated with Bacitracin-AgNCs at MBC, and the green fluorescence became weak, showing the bacterial membrane was severely damaged.The results of living/dead staining of S. flexneri cells are shown in S. flexneri cells.The effects of Bacitracin-AgNCs on two representative ATPase activities of S. flexneri cells of treated and control groups. In FESEM was performed to further observe the surface morphology of S. flexneri and the ESEM observation results are shown in The inhibitory rates of Bacitracin-AgNCs on biofilm formation of In ESEM images, the biofilm structure was highly dense with many wrapped bacterial cells in the control group. By contrast, the biofilm became loose and scattered, and the wrapped cells decreased after addition of Bacitracin-AgNCs at 1/16 MIC and 1/8 MIC concentrations. The biofilm structure under treatment at 1/4 MIC and 1/2 MIC concentrations was damaged with the disappearance of extracellular polymers. The cell integrity of some bacteria was destroyed, and almost no visible biofilm structure was observed after Bacitracin-AgNCs treatment at the MIC level. Meanwhile, LFX and bacitracin also had a certain inhibitory effect on the formation of biofilm, but the action was inferior to that of Bacitracin-AgNCs at MIC. The results indicate that Bacitracin-AgNCs damaged the biofilm integrity.Bacitracin is a polypeptide antibiotic that has bacteriostasis to not only Gram-positive bacteria, but also negative cocci, diplococcus pneumoniae, staphylococcus and spirochete. As a biological template, it can easily combine with metal ions to produce nanomaterials with stronger antibacterial effect. In this study, the UV-VIS absorption peak of the synthesized Bacitracin-AgNCs at 414 nm indicates that the required nanomaterial was successfully prepared. The optimum excitation and emission wavelengths were 384 nm and 460 nm respectively, which are consistent with the reported study  showing Staphylococcus aureus cell wall by combining with divalent metal ions such as Cu, Ni, Co, Zn and Mn, thereby inhibiting the growth of Staphylococcus aureus. Additionally, the antibacterial effect of the synthetic complex was better than that of pure bacitracin. The novel silver nanoparticles synthesized by a green method have broad-spectrum antibacterial properties against foodborne pathogens, involving Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Vibrio parahaemolyticus and Salmonella typhimurium [S. flexneri. These results indicate that bacitracin can bind to metal ions well, and the synthesized Bacitracin-AgNCs is a new antibacterial agent with efficient antibacterial properties. Growth curve and turbidity assays analyses further showed that the enhancement of the antibacterial effect of Bacitracin-AgNCs was related to the optical density decrease of S. flexneri. Wang et al. [Staphylococcus aureus, where higher concentrations of antibacterial agents led to lower growth rates.Peptides and antibiotics containing peptides can inhibit microbial growth via inhibition of the synthesis of cell wall, DNA and protein, and disrupting the integrity of the microbial membrane . Previouhimurium . In thisg et al.  revealed+ and phosphate from the cells. The released nucleotides have a strong UV absorption ability at 260 nm, so that, consequently, the integrity of the cell membrane can be evaluated in accordance with the UV absorption values of bacterial suspension at 260 nm [β-galactosidase cannot pass through the complete bacterial membrane, but can be detected by leaking to the outside of the bacteria when the cell membrane is damaged [The cell membrane is an important active structure with barrier function, which plays a vital role in maintaining metabolism and energy conversion, and it is between cytoplasm and extracellular medium . Many ant 260 nm . In Figut 260 nm . In addi damaged . Our resS. flexneri cell membrane in a dose-dependent manner (2 coating and silver nanoparticles changed the permeability of Staphylococcus aureus membrane, and caused damage to DNA by penetrating into the cells of bacteria.AO and EB are frequently used for the cell living/dead staining, and they were used to further estimate the effect of Bacitracin-AgNCs on bacterial membrane permeability in this study. AO can penetrate cell membrane and embed in the nuclear DNA to emit green fluorescence, while EB can only pass through the damaged cell membrane and stain dead cells when accompanied by red fluorescence . In our t manner A. ZawadzS. flexneri cells to destroy the membrane and lead to cell death, so does it affect the intracellular ATPase in the cell? In our study, Bacitracin-AgNCs significantly inhibited the activity of Na+ K+- and Ca2+ Mg2+-ATPase in S. flexneri, which may be due to the rapid termination of intracellular biosynthesis resulting from cell membrane depolarization [+ K+-ATPase is an immanent sodium pump in many eukaryotic cell membranes, which plays an important role in establishing and maintaining intracellular high K+ and low Na+ concentrations. Moreover, the establishment of Na+ electrochemical gradient on the plasma membrane is also crucial for some cell functions, such as pH regulation and nutrient absorption [ε-polylysine and nisin on Na+ K+- and Ca2+ Mg2+-ATPase activity of Bacillus subtilis [S. flexneri changed significantly after being treated with Bacitracin-AgNCs, and some small particles were attached to the cells, which may be the synthetic nanomaterials. The result further proves the damage to the cell membrane structure and the leakage of intracellular substances. Juan et al. [Vibrio parahaemolyticus cells, and that this phenomenon could result in changes in the cell’s morphology and membrane properties. Due to the adhesion of AgNPs to bacterial cells, a series of pores and holes were formed on the cells surface, causing the dissolution and death of Staphylococcus aureus [S. flexneri.Bacitracin-AgNCs can act on rization . Intracesorption . A similsubtilis . Furthern et al.  observeds aureus . In geneS. flexneri and a dose-dependent inhibitory effect on biofilm formation through a crystal violet quantitative experiment. ESEM observations further confirmed that Bacitracin-AgNCs destroyed the whole biofilm structure and greatly reduced the living cell counts in biofilms. These results are consistent with the description of a previous study [Escherichia coli and Staphylococcus aureus. Bacitracin-AgNCs hindered the normal growth and reproduction of bacteria by breaking the integrity of the biofilm. Biofilm is a widespread multicellular form in the process of bacterial growth, which can provide protection and the potential for homeostasis . Relevanus study , where iS. flexneri, a food-borne pathogen. It can be seen that Bacitracin-AgNCs unfolded potent antibacterial activity against S. flexneri and could inhibit the growth of bacteria at low concentrations. Bacitracin-AgNCs could destroy the integrity of membrane, resulting in visible morphological changes and the leakage of intracellular nucleotides, before cell proliferation was finally blocked. This study contributes to the interpretation of the antimicrobial mechanisms of Bacitracin-AgNCs as a new antibacterial agent against S. flexneri and lays the foundation for further research of its application in the food industry.In summary, a new type of Bacitracin-AgNCs nanomaterial was synthesized in a novel and eco-friendly manner. We used a variety of instruments to characterize the synthesized nanoclusters, and further studied the antibacterial activities and mechanisms of Bacitracin-AgNCs against


In the last decade, pieces of evidence for TDP-43-mediated mitochondrial dysfunction in neurodegenerative diseases have accumulated. In patient samples, in vitro and in vivo models have shown mitochondrial accumulation of TDP-43, concomitantly with hallmarks of mitochondrial destabilization, such as increased production of reactive oxygen species (ROS), reduced level of oxidative phosphorylation (OXPHOS), and mitochondrial membrane permeabilization. Incidences of TDP-43-dependent cell death, which depends on mitochondrial DNA (mtDNA) content, is increased upon ageing. However, the molecular pathways behind mitochondrion-dependent cell death in TDP-43 proteinopathies remained unclear. In this review, we discuss the role of TDP-43 in mitochondria, as well as in mitochondrion-dependent cell death. This review includes the recent discovery of the TDP-43-dependent activation of the innate immunity cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS/STING) pathway. Unravelling cell death mechanisms upon TDP-43 accumulation in mitochondria may open up new opportunities in TDP-43 proteinopathy research. TARDBP) on chromosome 1. It was found in the 1990s as a repressor protein associated with HIV-1 transcription, binding the TAR DNA sequence of the viral genome and regulating the viral gene expression . s. s36]. sTermsarasab and colleagues observed that endogenous TDP-43 is highly phosphorylated in mitochondria of the pontine nuclei, thalamus, Cornu Ammonis 3 (CA3) region of the hippocampus, and orbital cortex of young and normal aged mice without any evidence of neurodegenerative or systemic disorders . Throughmt) in T-Rex293 cells and in Drosophila expressing recombinant wild-type and mutant (A315T) TDP-43 [mt was the Lon protease 1 (LonP1), which degraded TDP-43 in vitro. LonP1 interacted with TDP-43 and reduced the mitochondrial TDP-43 protein levels in T-Rex293 cells and in Drosophila. The authors proposed a model where the mitochondrial damage by TDP-43 triggered the activation of LonP1. Another more physiological scenario could be that cytosolic TDP-43, misfolded or aberrantly post-translationally modified, is imported into mitochondria for degradation by LonP1  TDP-43 . One of by LonP1 A. IntereThus, despite the presence of mitochondrial localization motifs, physiological roles of mitochondrial TDP-43 on mitochondrial function remain speculative. Whether mitochondrial import of TDP-43 is a physiological mechanism to prevent its aberrant accumulation in the cytosol also needs further investigation.b, CYTB), and subunit 6 of ATP synthase (A6) in isolated brain mitochondria of mice overexpressing human wild-type or disease-associated TDP-43. TDP-43 overexpression directly impaired the loading of mitochondrial ribosomes onto mRNAs encoding for ND3 and ND6. These effects were corroborated in HEK293 cells overexpressing wild-type or disease-associated TDP-43 and in tissues from ALS-spinal cords or FTD cortices. Here, the levels of ND3 and ND6 were specifically reduced, whereas other OXPHOS proteins remained unaltered. Consequently, disassembly and dysfunction of complex I was observed, leading to reduced mitochondrial membrane potential, oxygen-consumption rate, and ATP levels  and in transgenic flies (wild-type and A315T variant) . Remarkamt, which has been observed in TDP-43 proteinopathy patients, in both cell line and transgenic flies expressing TDP-43, LonP1 would be incapable of degrading pathological mitochondrial TDP-43 [Reduced ATP synthesis driven by TDP-43 may have an additional deleterious effect: the previously described mitochondrial protease LonP1, which interacts with TDP-43 and eventually degrade it, is ATP-dependent. This could lead to a vicious cycle, where TDP-43 accumulates in the mitochondria, affecting ATP synthesis, thereby interfering with its own degradation via the LonP1 protease B. Despitl TDP-43 . This coc is released in the cytosol and binds Apoptotic protease activating factor-1 (Apaf-1), recruiting caspase-9 to form the apoptosome, which leads to the activation of the executioner caspases-3 and -7 [Mitochondria play a central role in orchestrating many subroutines of regulated cell death (RCD), including non-inflammatory intrinsic apoptosis and inflammatory necrotic cell death. One way by which mitochondria initiate cell death is through mitochondrial outer membrane permeabilization (MOMP). MOMP nearly always leads to cell death and is, therefore, tightly regulated through the Bcl-2 superfamily, comprising pro-apoptotic, anti-apoptotic, and death effector proteins. In intrinsic apoptosis, once activation of the cell death effectors Bax and Bak is triggered, cytochrome 3 and -7 ,56. The 3 and -7 ,58.1F0 ATP synthase, Adenine nucleotide translocator (ANT), and mitochondrial Phosphate Carrier (PiC) [Intrinsic apoptosis and inflammatory cell death can also be mediated by prolonged opening of the mitochondrial permeability transition pore (mPTP) in response to oxidative stress . The strer (PiC) . Some reer (PiC) ,61 and rer (PiC) ,63. Otheer (PiC) ,65,66. Her (PiC) , and VDAer (PiC) . mROS reer (PiC) , whereaser (PiC) .cGAS is a cytosolic DNA sensor, playing a major role in the innate immune response by binding foreign and self-DNA. Binding of DNA triggers the production of cGAMP, which activates STING, which in turn recruits and activates Serine/threonine-protein kinase-1 (TBK1). TBK1 phosphorylates the transcription factor Interferon regulatory factor-3 (IRF3), which dimerizes, translocates in the nucleus, and activates the type I interferon response. The activation of the cGAS/STING pathway has also been brought in relationship with increased necroptosis through a Tumor necrosis factor (TNF)-dependent mechanism  Figure B. The cGc did not rescue TDP-43-triggered clonogenic cytotoxicity in yeast [In yeast expressing human TDP-43, a critical interplay between mitochondria, mtDNA, and TDP-43-mediated regulated cell death was already described in 2011 , which win yeast . TherefoAs mentioned before, Wang and colleagues described the vicious cycle of TDP-43 accumulation in the mitochondria, ATP depletion, and therefore, inability of ATP-dependent LonP1 to clear up the mitochondrion from too much TDP-43 . UltimatIfnb1) and Tumor necrosis factor (Tnf). Downstream of these events, it was shown that in response to TDP-43  overexpression in HEK293T cells, cGAS was bound to mtDNA, leading to activation of STING, which upregulated NF-κB and type I interferon pathways. Similarly as seen in yeast [TDP-43 proteinopathies, such as ALS, are often associated with inflammation with the release of NF-κB-related cytokines and elevated type I interferon response. In mouse models, these inflammatory signals were seen before onset of the symptoms of the disease, suggesting that they play a role in disease pathogenesis. Whether the cGAS/STING pathway is involved in inflammation in TDP-43 proteinopathies has not been elucidated until recently . The actin yeast , mtDNA dIn contrast, other groups reported an involvement of the canonical intrinsic apoptotic pathway ,80 FiguB. SuzukiThus, TDP-43 triggers mitochondrion-dependent cell death in yeast and mammalian cell and animal systems. Both anti-inflammatory apoptosis and pro-inflammatory necrosis can be observed, and the mtDNA plays a central role in regulated cell death.TDP-43 is a disease-associated RNA/DNA-binding protein, which localizes to the nucleus, the cytosol, and the mitochondria. In this review, we focused on potential physiological and pathological roles of mitochondrial TDP-43, how TDP-43 may trigger regulated cell death with a pivotal contribution of mitochondria, and in which way mt-RNA and mtDNA are involved in these processes .Whether TDP-43 does have physiological functions in mitochondria is still unknown. As TDP-43 bears mitochondrial localization motifs  and as ic has been described as effect of mitochondrial outer membrane permeabilization (MOMP)  B. It wouElucidating the physiological and pathological roles of mitochondrial TDP-43 species and their effects on cell survival and cell death will be a challenging task. The cells continuously integrate functional and toxic signals from a variety of TDP-43 species from different compartments, including the nucleus, the cytosol, and potentially other membranous compartments and organelles. However, it will markedly contribute to a better understanding of molecular pathways underlying TDP-43 proteinopathies, and potentially identify novel targets for pharmacological interventions.


The identification of faked identities, especially within the Internet environment, still remains a challenging issue both for companies and researchers. Recently, however, latency-based lie detection techniques have been developed to evaluate whether the respondent is the real owner of a certain identity. Among the paradigms applied to this purpose, the technique of asking unexpected questions has proved to be useful to differentiate liars from truth-tellers. The aim of the present study was to assess whether a choice reaction times (RT) paradigm, combined with the unexpected question technique, could efficiently detect identity liars. Results demonstrate that the most informative feature in distinguishing liars from truth-tellers is the Inverse Efficiency Score  to unexpected questions. Moreover, to focus on the predictive power of the technique, machine-learning models were trained and tested, obtaining an out-of-sample classification accuracy of 90%. Overall, these findings indicate that it is possible to detect liars declaring faked identities by asking unexpected questions and measuring RTs and errors, with an accuracy comparable to that of well-established latency-based techniques, such as mouse and keystroke dynamics recording.The online version of this article (10.1007/s00426-020-01410-4) contains supplementary material, which is available to authorized users. Millions of people have their identities stolen every year. There is no fool-proof way to pinpoint fakers, especially when faked identities are used to register online. Traditional methods of lie detection include face-to-face interviews and polygraphs that measure heart rate and skin conductance  would have been sufficiently large to achieve at least a statistical power (1 − β) = 0.90, given a significance level (α) = 0.05 and an effect size (Cohen’s d) = 2.33 (note that the effect size is referred to the variable IES unexpected)  took part in the experiment. Power calculations indicated that a sample size = 50 in a between-subject design (Data collected from 40 participants were used as a training set to build machine learning (ML) models and data from the remaining 10 subjects were used as a test set, to evaluate the model generalization capabilities. The demographic data of training and test samples are reported in Table Participants were randomly assigned either to the liar or to the truth-teller group. Therefore, half of the sample performed the task as liars and the other half performed the task as truth-tellers.The Ethics Committee for Psychological Research at the University of Padua approved the experimental procedure.The experimental procedure was similar to that previously reported . They were required to solve the same mathematical and logic tasks as the liar group, to balance the cognitive load before undertaking the computerized task. They repeated their personal data  only once after the distracting mathematical riddles.® 2.0  into the system. Finally, they were asked to complete the computerized task that required them to respond to questions about their identity. The experiment was programmed in E-PrimeEach participant was required to respond to 78 questions in total, including 18 control questions, 20 expected questions and 40 unexpected questions. All the questions were in the form of affirmative sentences that required a "yes" or "no" response, with a perfect balance, so that half of them required a “yes” response and the other half a “no” response, for both liars and truth-tellers.The expected questions consisted of personal information provided by each subject in their ID, such as first name, family name, date and place of birth, residence address, profession and civil state. Liars expected to be tested on these pieces of information, as the first experimenter had made sure that each liar could perfectly recall the new identity and recommended each of them to cheat the second experimenter.The unexpected questions concerned information that, though not explicitly presented in the IDs, could be extracted from the basic information contained in the IDs. Truth tellers did not need to think about the right answers to the unexpected questions, as extracting derived-from-the-ID-data information was an automatic and easy process for them. For instance, if you were born on April 20th, you should also know that your zodiac is Aries; if you lived in Padua, you should know the area zip code. By contrast, as the liars had learned their fake ID data, they needed a much greater cognitive effort and a longer time to answer unexpected questions. As a result, the liars showed increased response times and higher errors rates.Finally, the control questions included some objective features of the participants that were directly verifiable by the experimenter, such as their gender, hair and eye colour or what they were wearing during the experiment.In summary, each subject responded to 9 control questions requiring a “no” response, 9 control questions requiring a “yes” response, 10 expected questions requiring a “no” response, 10 expected questions requiring a “yes” response, 20 unexpected questions requiring a “no” response and 20 unexpected questions requiring a “yes” response. Examples of questions are reported in Table Stimuli appeared in random order in the center of the computer screen and two response labels were placed, respectively, in the right and in the left upper corners of the screen. To give their response, subjects were instructed to press either the key “A” or the “L” on the computer keyboard that corresponded respectively to the left and the right response label. Moreover, they were instructed to press the response key on the computer keyboard as fast as they could and, at the same time, they had to try to be as much accurate as they could. Each stimulus appeared automatically after the response to the previous one, so no action was required to the subjects to bring up each new question. No temporal response limit was fixed and no feedback was provided for responses.During the task, we recorded RTs and numbers of errors. For errors, we mean the wrong responses provided by subjects according to the information that they reported, independently from the fact that they were liars or truth-tellers. Then, for each participant we computed the average RTs and the average number of errors, separately for control, expected and unexpected questions. Moreover, RTs were calculated separately for wrong and right responses. Then, we calculated the Inverse Efficiency Score (IES), an index that combines speed and accuracy , RT wrong unexpected , IES expected , IES unexpected . Note that responses to control questions were discarded by the feature selection algorithm, as they did not carry any useful information to distinguish the two groups (truth-tellers vs liars).Feature selection consists in the process of automatically selecting the best subset of predictors, to maximize the model accuracy, that is, in our specific case, the accuracy in discriminating between liars and truth-tellers. Feature selection is a widely used procedure in machine learning (ML) Hall, , as it aTable Table F = 7.80, p < 0.01, η2 = 0.06]. In addition, both liars and truth-tellers had longer RT in responding to unexpected questions compared to expected questions . No statistically significant results emerged from the interaction condition (liars vs. truth-tellers) X type of question (expected vs. unexpected).An ANOVA was run to investigate the difference between the two experimental groups (liars vs. truth-tellers), both for RT in wrong responses and IES. RTs to wrong responses of liars were longer than those of truth tellers . Moreover, both liars and truth-tellers had greater IES in responses to unexpected questions compared to expected questions . Finally, the interaction condition (liars vs. truth-tellers) X type of question (expected vs. unexpected) was statistically significant . Indeed, data showed a larger difference between liars and truth-tellers based on unexpected compared to expected questions .In the last years, researchers from different scientific fields have emphasized the utility of focus on prediction rather than explanation when data are analysed  were entered in five different ML algorithms: Logistic  was used to train and validate the model, while another part  was set aside to test the model accuracy on new examples that had never been seen by the ML classifier  failed in recognizing two liars in the cross-validation procedure and one truth-teller in the test set.Detecting liars of personal identities is becoming an increasing important goal, as faked identities plague more and more the web and social networks. This is due to the fact that personal identities information can be easily learned and rehearsed to a point that lies are expressed as naturally and automatically as truths. Different researches capitalised on the use of unexpected questions and the use of mouse or keystroke dynamics to overcome automaticity in rehearsed lies .The most relevant predictor that contributed to detecting liars was IES (a measure that is intended to handle speed-accuracy trade-off). Moreover, as concerns IES, the differentiation between liars and truth-tellers is much stronger with unexpected compared to expected questions, confirming that using unexpecting questions is a promising approach.The time taken to wrongly respond to expected and unexpected questions also contributed to the classification model performance. It should be noticed that truth-tellers had very short RTs when they gave wrong responses to expected questions. This indicates that when a truth-teller fails in responding to expected questions, this is probably due to the speeded impulsivity in the response. On the other hand, the errors of the liars likely were due to incapacity to retrieve the correct information.The results are not model-dependent, as a variety of ML models that rely on very different assumptions performed at similar levels of accuracy.The results reported here confirm that the most informative features in distinguishing between liars and truth-tellers are the IES and the RT to wrong responses, both to expected and unexpected questions. More precisely, our analysis indicated that:To conclude, it is possible to spot liars declaring faked identities by asking unexpected questions and measuring RT and errors with an accuracy equivalent to that of mouse and keystroke dynamics recording Below is the link to the electronic supplementary material.


Dementia-Friendly America is a network of communities across the United States who have committed to a process to support people living with dementia and their caregivers. Through technical support from Dementia Friendly Illinois, CATCH-ON, a HRSA Geriatric Workforce Engagement Program, has identified key characteristics for the 17 communities in Illinois achieving national recognition and for communities that have engaged but not yet achieved national recognition. In addition to communities in rural regions, urban communities with a large number of African Americans residents have necessitated more grassroots engagement than other communities. Partnerships are vital for providing information and education about the movement and for supporting multi-sectoral engagement. This presentation highlights barriers and facilitators in diverse communities, particularly urban African American communities, becoming recognized by Dementia Friendly America.


Verrucous sarcoidosis is a rare cutaneous variant of sarcoidosis, an inflammatory disease characterized by non-caseating granulomas that primarily involves the lungs. The current literature on verrucous sarcoidosis is limited, with the majority of lesions presenting on the lower extremities of African American males. Here, we present two cases that highlight the unique manifestations of this uncommon cutaneous entity. The first case involves a middle-aged Hispanic woman with lesions on her arms and face, and the second case involves a middle-aged African American woman with sole facial involvement. A multi-disciplinary approach to diagnosis and treatment is required as verrucous sarcoidosis can present with clinical and histopathological features indistinguishable from infectious etiologies and has an association with pulmonary sarcoidosis. Adalimumab has demonstrated success in the treatment of verrucous sarcoidosis. Sarcoidosis is a chronic, inflammatory disease that manifests across multiple organ systems. This condition is found more commonly in women, particularly those of African descent. Compared to their Caucasian counterparts, African Americans tend to present earlier and with more acute manifestations . AlthougAfter the lungs, the skin is the next most commonly affected organ. Cutaneous involvement is often an early finding and is present in up to 35% of cases , necessiCase 1A 51-year-old Hispanic woman presented with a two-year history of progressive pruritic plaques on her face, upper extremities, and trunk. She was diagnosed with pulmonary sarcoidosis in 2005. Five years later, she developed cutaneous sarcoidosis, confirmed by a skin biopsy showing non-caseating granulomas. Her systemic sarcoidosis had been treated with chronic prednisone up to 40 mg daily. Two months prior to presentation, the patient’s pulmonologist initiated her on methotrexate 7.5 mg daily as adjunctive therapy to the prednisone. Neither treatment had improved her skin eruption.On physical examination, there were hyperkeratotic, annular, erythematous plaques with heaped-up borders on her arms and face Figure , as wellA total of four punch biopsies were performed, two from the verrucous lesion of the face and two from the non-verrucous lesions. Biopsies from the non-verrucous lesions demonstrated nodular sarcoidal granulomas. Two biopsies of the verrucous plaque on the right cheek showed striking verrucous hyperplasia with suppurative granulomatous inflammation in the superficial dermis and nodular sarcoidal granulomas in the deep dermis Figures , 3. PeriAfter carefully excluding an infectious etiology, cutaneous verrucous expression of sarcoidosis was established. The patient was started on adalimumab with marked improvement after nine months of therapy and continued improvement after 21 months of therapy.Case 2A 60-year-old African American woman presented with a 10-month history of plaques on her nose and preauricular area Figure . Her pasA 4-mm punch biopsy of the nose revealed marked pseudoepitheliomatous hyperplasia with underlying nodular sarcoidal granulomas in the dermis, consistent with sarcoidosis. An AFB stain revealed no organisms.The patient was treated with intralesional triamcinolone. No significant improvement was noted after one month, and she was started on 0.05% clobetasol ointment. Four months following clobetasol initiation, the patient had marked improvement. She also continued her weekly methotrexate.Verrucous sarcoidosis is an exceedingly rare manifestation of cutaneous sarcoidosis. Most of these cases involve the lower extremities of African American men . FurtherOur cases represent unique manifestations of this uncommon entity. First, our patients are both females rather than males. Additionally, our first patient is Hispanic instead of African American. There are only four other reported cases of verrucous sarcoidosis in a non-African American patient ,5,10,11.Sarcoidosis has often been referred to as the “great imitator” of other skin diseases . This isInitial treatment of cutaneous sarcoidosis can incorporate topical, intralesional, and systemic steroids . AlternaIn conclusion, verrucous sarcoidosis is a rare cutaneous variant of sarcoidosis that may present with clinical and histopathological findings that are indistinguishable from an infectious etiology, such as a deep fungal infection. As verrucous sarcoidosis has a high clinical association with pulmonary sarcoidosis, this rare expression of sarcoidosis should be managed with an interdisciplinary healthcare team. Treatment modalities include corticosteroid, immunomodulatory, and biologic therapies. Such lesions are often stubborn in response and may require a multi-faceted approach.