Artificially-induced defects in the lattice of graphene are a powerful tool for engineering the properties of the crystal, especially if organized in highly-ordered structures such as periodic arrays. A method to deterministically induce defects in graphene is to irradiate the crystal with low-energy (<20 keV) electrons delivered by a scanning electron microscope. However, the nanometric precision granted by the focused beam can be hindered by the pattern irradiation itself due to the small lateral separation among the elements, which can prevent the generation of sharp features. An accurate analysis of the achievable resolution is thus essential for practical applications. To this end, we investigated patterns generated by low-energy electron irradiation combining atomic force microscopy and micro-Raman spectroscopy measurements. We proved that it is possible to create well-defined periodic patterns with precision of a few tens of nanometers. We found that the defected lines are influenced by electrons back-scattered by the substrate, which limit the achievable resolution. We provided a model that takes into account such substrate effects. The findings of our study allow the design and easily accessible fabrication of graphene devices featuring complex defect engineering, with a remarkable impact on technologies exploiting the increased surface reactivity. Defects in the crystal lattice of graphene are usually undesired as they hinder many of the remarkable properties of graphene devices. For instance, the presence of defects causes the broadening of the phonon dispersion and the lowering of the electronic mobility ,2. HowevWhen periodically repeating defected features, additional novel graphene functionalities can be unlocked. For example, a periodic array of defect lines in a graphene sheet can further tailor graphene’s thermal properties by introducing an anisotropy in the thermal conductivity ,14. MultLow-energy <20 keV, ) electro keV,  elp, showing that the resolution of a multiple-line pattern is not only determined by the EBI system characteristics  but is also limited by the pattern parameters themselves.Defect-engineered graphene for plasmonic and electronic applications requires well-defined patterns, where defect-rich and defect-free areas are well distinguished. For this reason, when introducing defective patterns such as line gratings via EBI, the investigation of both the defect density and surface topography is fundamental in order to establish the efficacy of the pattern creation. In this context, we present the study of the periodic arrays of defective lines induced in exfoliated graphene on a silicon oxide/silicon  with a scanning velocity of 500 nm/min. Such settings allowed a resolution of ∼2 The impact of the defects on the crystal lattice was studied by micro-Raman spectroscopy just after the electron irradiation in ambient air. The flakes were analysed by a 532 nm laser with 100× objective (NA = 0.85), giving a lateral resolution AFM and micro-Raman were performed to study the role of the pattern pitch on the surface topography and the defect density of electron-irradiated graphene sheets.In the AFM scans, the patterned arrays always resulted in a regular local increase of the topographic height. An example of an AFM map is shown in p of as low as 50 nm. Contrarily, the extracted line for 35 nm shows an overall height increase of ∼1 p varying from 50 nm to 100 nm exhibit a clear first harmonic peak at p = 35 nm shows a distinct first harmonic peak at 35 nm  of the height oscillations, we observed a pitch dependency of the defective graphene topography also for the patterns having a pitch longer than the beam radius. In particular, as shown in p increased, suggesting an unexpected dependency of the surface chemical reactivity on the pattern pitch and thus a variation of the defect density when changing p. Instead, the width of the patterned lines was constant within the error at a value that is compatible with the e-beam spot dimensions (p dependency of the height may arise from the interaction of electrons back-scattered by the substrate (BSEs) with the adjacent lines previously irradiated. Indeed, BSEs retain most of the energy of the primary electrons and can be spread in an area of radius To analyse the height variations, a single profile line was extracted from the AFM scans by averaging multiple lines for all the patterns. As shown in hene see , albeit mensions b, demonsted spot . Therefoted spot . Indeed,ted spot .D and 3-like and vacancy/boundary-like defects reported for short pitches  ,30 when graphene  and theiches see . The peaorted in :(1)nD[cmn eV see . The ext defects ,34. As sp dependency of the induced defects, we have to consider that the EBI induces a certain density of defects A has the same unit of p. The fitting parameter values are listed in A transposed by the equation, the term To interpret the observed adiation  and A haG (G and G peaks, which means that there was a change in the doping of the crystal, i.e., from ∼3–4 p, which went from ∼4.5 p = 100 nm to ∼6.5 p = 20 nm [G peak before and after the irradiation [G peak is determined by the competitive action of the carrier concentration, which narrows the G peak and defects density, which broadens the peak. However, electron-defect scattering mainly dominated when To investigate how the pattern pitch influenced the doping and strain of the defective graphene flakes, we studied the behaviour of the positions of the  = 20 nm  This behadiation , as repoD/IG ≥ 3  and in bubstrate . Indeed,ubstrate ,37, thusp = 100 nm to p = 20 nm. In Set 2, it varied from p = 100 nm to p = 35 nm [On the other hand, ased see b,d. The rn pitch . Indeed,D/IG ≤ 3 ,39, wherD/IG ≤ 3 ,40. As ap as small as The features of periodic arrays of structural defects in graphene were studied by combining AFM and micro-Raman spectroscopy. Defected lines were generated by low-energy EBI in monolayer graphene. The AFM measurements demonstrated that it was possible to create well-defined periodic patterns with a pitch The analysis of the Raman signal showed that the 2D density of defects induced in the crystal increased when the distance between each line decreased. Both Raman and AFM analyses confirmed that such a change was not a simple In conclusion, we demonstrated that it was possible to generate periodic arrays of defects in a graphene sheet, which could be exploited for designing engineered electronic devices or for inducing optically active features of unprecedented resolutions. Such features, combined with the increased surface reactivity of defected graphene, could have a great impact on both novel solid-state studies and the design of closely-packed chemical and radiation sensors.


Owing to its novel properties, such as high electrical conductivity and large specific surface area, graphene has been found as suitable support material for the electrocatalyst design. This work reports the preparation of platinum-nickel alloy nanoparticles (PtNi NPs) electrocatalyst by electrodeposition of PtNi NPs onto graphene support. The obtained PtNi/graphene electrocatalysts were characterized by high resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray microscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) indicating the controllable morphological and compositional profiles of PtNi NPs on graphene. The electrocatalytic characteristics of PtNi/graphene toward oxygen reduction reaction (ORR) were systematically investigated showing comparable kinetic performance. Moreover, the graphene during electrodeposition process induces carbon vacancies and defects, increasing interaction between nanoparticles and graphene and enhancing electrocatalytic stability by limiting aggregation of the nanoparticles during accelerated stability test. This work opens a promising path for the preparation of graphene-supported alloy electrocatalyst. Electrochemical energy conversion and storage devices are critical enabling technologies for carbon-neutral renewable energy . These sAs an atomically thin sheet of hexagonally arranged carbon atoms which offer fast electron transferring, graphene has attracted a lot of interest for various applications . The univia electrodeposition method as developed by In this study, we used one-pot flash Joule heating (FJH) method to obtain high-quality graphene , and syn2PtCl4, 98%, RHAWN), nickel dichloride , sulfuric acid , perchloric acid . Argon and oxygen gases having high purity (>99.99%) were purchased from Yihong Gas Company, China. Deionized water  was purified by passing through pure compact ultrapure water system .All of the chemicals are of analytical grade and used without further purification. Commercial references of Vulcan carbon-supported Pt electrocatalyst  was purchased from TKK, Japan. Other reagents are as follows: isopropanol , Nafion D521 dispersion , potassium tetrachloroplatinate  glassy carbon (GC) disk  was immersed into 0.1 M HClO4 as the working electrode. The thin film catalyst layer on GC was formed by drop casting from a catalyst ink and drying under a flow of Ar. The catalyst ink was prepared by sonicating solid catalyst powder in a 4:1 H2O:IPA volume ratio solvent solution with concentration of 1 mgcatalyst ml−1. In order to well disperse and stabilized the catalyst particles on the GC surface, 0.5 µL of Nafion 5 wt% solution per mg of catalyst was added to the ink. Cyclic voltammograms (CVs) were performed with Ar purging at 294 K, with the potential scanned from 0.0 to 1.1 V vs. RHE at 20 mV s−1, and were used to determine the electrochemically active surface area of the Pt catalyst by integrating hydrogen desorption (∼0–∼0.35 V vs. RHE). ORR activities were measured in O2-saturated 0.1 M HClO4 at 294 K, with the potential scanned between 0.1 and 1.1 V vs. RHE at 20 mV s−1 at a rotation rate of 1600 rpm. All potentials are corrected for iR drop within the electrochemical cell.The electrocatalysts were electrochemically characterized in a three-electrode cell with a rotating disk electrode (RDE) setup (Pine Instruments) controlled by a Donghua potentiostat DH7003). The Pt wire  was used as the counter electrode, and the Ag/AgCl (BASi) was used as the reference electrode. The Pt loaded  at a constant rate of 10°C min−1, using a Netzsch STA 449 F3 system. The catalyst (≈10 mg) was loaded into an alumina crucible and heated from room temperature to 1000°C. X-ray diffraction (XRD) profiles were collected on Bruker D8 spectrometer with Cu Kα radiation (λ = 0.15406 nm). X-ray photoelectron spectra (XPS) were carried out using a Thermo Scientific K-Alpha X-ray photoelectron spectrometer. The binding energy was corrected using the C 1 s peaks (284.5 eV) as reference. Raman measurement was performed on a Renishaw in via Raman spectrometer with an excitation wavelength of 785 nm.High angle annular dark field scanning transmission electron microscopy (HAADF-STEM) images were taken of samples supported on lacey carbon grids in a FEI talos F200x G2 TEM/STEM operated at 200 keV. Energy dispersive spectroscopy (EDS) in the STEM mode was employed for elemental composition and distribution of the catalyst particles. Thermogravimetric analysis (TGA) of the catalysts was carried out under a mixed gas atmosphere  conversion of the surface complexes to PtNi alloy nanoparticles through potential cycling. The electrochemical deposition route of PtNi NPs on graphene is illustrated in via translation or rotation while the interlayer spacing approaches that of crystalline graphite (0.335 nm) (The XRD pattern of bare flash graphite obtained by FJH and as-made PtNi/graphene is shown in .335 nm) . After d.335 nm) . No char.335 nm) . The sli.335 nm) .0, PtⅡ, and PtⅣ. The observed binding energy of Pt0 is 71.49 and 74.93 eV agreeing well with the reported value of Pt0  in an electrochemical system can be used to determine electrochemical active surface area (ECSA), which is essential for understanding the utility of Pt by evaluating the number of available electrochemically active sites , and the value of 0.21 is known as the charge for the monolayer if hydrogen adsorption on the Pt surface. The corresponding ECSA of Pt is determined to be 73.9 m2/g for the PtNi/graphene which is comparable to commercial reference of Pt-based electrocatalyst supported by Vulcan carbon , jd is the diffusion limiting current density under the potential region of 0.2–0.65 V vs. RHE, and jk is the kinetic current density which can be obtained based on K-L equation to adjust for mass transport limitations.  due to excellent electrical conductivity of the graphene. RCT of graphene obtained using FJH method in our previous work,  is commonly used to illustrate the defect nature in the atomic structure of the graphene , suggesting the formation of many structural defects or disorders on the graphene support where PtNi NPs are deposited(ID/IG)  . This deID/IG) . Using dID/IG)  has revetivities . (Lim antivities vs. RHE in 0.1 M HClO4 at 50 mV s−1 under Ar atmosphere as suggested in our previous work (An accelerated stability test (AST) of PtNi/graphene was also performed by cycling potentials between 0.6 and 1.1 V ous work , and theous work  reservesous work , preventIn summary, novel Pt-Ni binary alloy nanoparticles electrocatalysts supported on graphene nanomaterials were successfully prepared by electrodeposition method. The PtNi NPs with sizes of ∼3 nm uniformly dispersed on graphene surface and loading of metals was determined to be 20 wt%. The resultant PtNi/graphene exhibits excellent electrocatalytic activity and stability toward the reduction of oxygen. In addition to the improved surface electronic properties due to characteristic of graphene, the formation of structural defects and disorders on graphene support during electrodeposition process can also attribute to the electrocatalytic performance of PtNi NPs. These results indicate that graphene nanomaterials could be a good candidate as a supporting material of electrocatalysts, and electrodeposition method is promising for the preparation of high-performance graphene-supported alloy electrocatalysts.


Forkhead Box Protein C2 (FOXC2) belongs to the Forkhead/Wing-helix family. The regulatory role of this transcription factor in physiological function and carcinogenic activity has been proven in subsequent investigations. However, there is still scarcity of evidence on the relationship between FOXC2 expression and prognosis in human solid tumors. We conducted this meta-analysis to evaluate the role of FOXC2 as a prognosis factor and a possible target marker in human solid tumors.PubMed, Web of Science, Embase, and the Cochrane library database were all searched methodically. Eligible publications on FOXC2 in human solid tumors were gathered and reviewed. The effect sizes were calculated using pooled hazard ratios (HRs) or odds ratios (ORs) with the corresponding 95% confidence interval (CI). Statistical analysis was conducted with Stata SE12.0.This meta-analysis comprised 3,267 patients from 20 studies covering a variety of solid tumors. Increased FOXC2 expression was related to shorter overall survival (OS) . High expression of FOXC2 is associated with lymph node metastases , TNM stage , and age , according to the pooled ORs. However, no significant association was observed between the high expression of FOXC2 and sex, tumor size or tumor differentiation.Increased expression of FOXC2 is associated with unfavored OS, lymph node metastases, TNM stage, and age. FOXC2 is a promising prognostic marker and a novel target marker in human solid tumors. The transcription factor forkhead box (FOX) is a family with a highly conserved winged-helix DNA-binding domain , 2. FOX in vivo and in vitro. FOXC2 has also merged as a potential molecular target in preclinical/clinical studies due to the dysregulated expression level and nuclear localization. Previous studies have associated expression levels of FOXC2 with clinical and pathological characteristics including tumor size, differentiation, metastasis, and stage  AND  AND . Additional research was found by looking through the references of the selected articles. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement was used in this analysis  patients with solid tumors diagnosed pathologically; (2) the expression FOXC2 in tissue were determined by immunohistochemistry (IHC) or quantitative real-time polymerase chain reaction (q-PCR); (3) available data for calculating odds ratio (OR) with 95% CIs were depicted; (4) only the study with the most extensive or recent data was considered, if multiple publications used employed overlapping samples from the same institution; (5) patients were categorized into groups based on high and low FOXC2 expression levels. Exclusion criteria in this meta-analysis were as follows: (1) duplicate publications; (2) research with no data or data from animal or cellular experiments; (3) only serum levels of FOXC2 expression were detected; (4) studies only provided Kaplan-Meier curves but no multivariate data; (5) reviews, letters, case reports, or expert opinions.The two independent investigators screened the all publications, classified and sorted out the titles and abstracts of the literature retrieved from reading, excluded duplicate literatures and literature failed inclusion criteria, contacted the original author for relevant information for the literature with incomplete information report, and determined whether it could be included in the final study after obtaining the full text. The research team shall assist in solving any dispute. The following information was retrieved from eligible articles: name of first author; publication year; sample size; cancer kind; criteria for increased expression of FOXC2; detecting methodology; outcome measuring; patient follow-up; HRs with corresponding 95% CI; and clinical characteristics . We preferred multivariate analysis in research with both univariate and multivariate analyses because it is better at explaining confounding factors. If there was a disagreement, a compromise was sought through debate until everyone agreed. The quality evaluation for eligible studies was undertaken by 2 independent investigators (CW and LZ), and any discrepancies were handled by consensus among all authors. The Newcastle-Ottawa Scale (NOS) tool was used to evaluate the quality of all eligible studies . The NOSI2 statistic , the fixed-effects model was adopted, and the random-effects model was used for others . The sensitivity analysis was conducted to check the stability of results. Begg's and Egger's tests were conducted to investigate potential publication bias . The heterogeneity of the included studies used Chi-square-based Q test and tatistic . P < 0.0ion bias . Differen = 12), Japan (n = 5), Singapore (n = 1), Spain (n = 1), and Norway (n = 1). Mean of patient sample size was 163 (from 61 to 338). In this meta-analysis, 15 varying solid tumor kinds were summarized, including 2 non–small-cell lung cancer, 2 breast cancers, 2 esophageal squamous cell carcinoma, 2 colorectal cancer, 2 cervical cancer, and 1 each of glioma, oral squamous cell carcinoma, pulmonary neuroendocrine tumors, extrahepatic cholangiocarcinoma, hepatocellular carcinoma, gastric cancer, oral tongue squamous cell carcinoma, ovarian cancer, prostate cancer, and phyllodes tumor of the breast. All of the specimens were well preserved, and diagnosis was made based on pathological findings. The main characteristics of enrolled studies are summarized in The procedure of literature retrieval was depicted in I2 = 13.1%, Ph = 0.313). HRs for the increased FOXC2 expression against the low FOXC2 expression were 2.31 (95% CI: 1.73–2.42)  was reported. The pooled hazard ratios (HRs) and corresponding 95% CI were estimated by the fixed-effects model. The results indicated a mild heterogeneity in studies (73–2.42) . PatientP < 0.05) (P < 0.05) (P < 0.05) (The pooled results  showed t < 0.05) , TNM sta < 0.05) , and age < 0.05) . However < 0.05) , sex, orSensitivity analysis was conducted to assess the FOXC2 expression and OS by gradually deleting each individual research from the pooled analysis. The purpose of this approach is to evaluate the impact of the deleted data set on the overall HRs. The fingdings were reliable, and the exclusion of any study had no effect on the results .Begg's Test and Egger's tests were conducted to evaluate the publication bias. Findings revealed that there was no publication bias between FOXC2 expression and OS in the included studies .As a kind of genomic disease, lots of somatic mutations, structural mutations and gene recombination occur during the carcinogenesis process . There wFOXC2 acts as a key mediator of tumor initiation and progression, involving tumor proliferation, migration, invasion, metastasis, and EMT . FOXC2 oThe limitations of this analysis were as follows: first, in this meta-analysis, the majority of the studies were conducted among Asian population. Other ethnic groups, such as Europeans, Africans and Americans, are relatively under-studied, which may limit the global applicability of the results discussed. Further high-quality studies from diverse ethnical origins are necessary to investigate the therapeutic importance of FOXC2. Second, despite the fact that FOXC2 overexpression was associated with patient age, tumor differentiation, lymph node metastasis and TNM stage, we were unable to evaluate the association between FOXC2 overexpression and other clinical and pathological characteristics due to insufficient data. Third, the number of studies included in this analysis could restrict its statistical power. Although no publication bias was found, potential publication bias may still exist due to the insufficient studies available for assessments. Then, inconsistencies in detecting platforms, methodologies, and criteria for IHC or RT-PCR, and distinct tumor kinds with varying prognostic differences may lead to skewed results. Furthermore, the mean of NOS scores is 6.5, implying that the quality of studies in this analysis is acceptable but not supreme, which might be inevitable in meta-analysis. Finally, the combined predictive significance of FOXC2 and other tumor markers was not assessed. As a result, higher quality multicenter studies with larger population, as well as consistent criteria for assessing the expression of FOXC2, are necessary for validation of the findings.In this analysis, increased expression level of FOXC2 is associated with poor prognosis, as well as TNM stage, lymph node metastases, and age. FOXC2 could serve as a novel prognostic marker in solid tumors. For these patients, targeting FOXC2 could be a feasible treatment option. To corroborate the findings, further well-designed pre-clinical/clinical studies with high-quality data are needed.


Dear Editor,Advanced basal cell carcinomas (BCCs), including metastatic BCC (mBCC) and locally advanced BCC (laBCC) have always represented a difficult‐to‐treat form of skin cancer; laBCC are primary, recurrent tumors that often progress to an advanced stage requiring treatments different from surgery or radiation therapy.None.Idea and design: Alessia Villani, Gabriella Fabbrocini and Massimiliano Scalvenzi. Data collection: Alessia Villani. Revision of the article: Alessia Villani, Massimiliano Scalvenzi.Approval of ethical committee was obtained from the University Federico II of Naples, Italy.