The required distal margin in partial mesorectal excision (PME) is controversial. The aim of this systematic review was to determine incidence and distance of distal mesorectal spread (DMS).A systematic search was performed using PubMed, Embase and Google Scholar databases. Articles eligible for inclusion were studies reporting on the presence of distal mesorectal spread in patients with rectal cancer who underwent radical resection.Out of 2493 articles, 22 studies with a total of 1921 patients were included, of whom 340 underwent long-course neoadjuvant chemoradiotherapy (CRT). DMS was reported in 207 of 1921 (10.8%) specimens (1.2% in CRT group and 12.8% in non-CRT group), with specified distance of DMS relative to the tumor in 84 (40.6%) of the cases. Mean and median DMS were 20.2 and 20.0 mm, respectively. Distal margins of 40 mm and 30 mm would result in 10% and 32% residual tumor, respectively, which translates into 1% and 4% overall residual cancer risk given 11% incidence of DMS. The maximum reported DMS was 50 mm in 1 of 84 cases. In subgroup analysis, for T3, the mean DMS was 18.8 mm (range 8–40 mm) and 27.2 mm (range 10–40 mm) for T4 rectal cancer.DMS occurred in 11% of cases, with a maximum of 50 mm in less than 1% of the DMS cases. For PME, substantial overtreatment is present if a distal margin of 5 cm is routinely utilized. Prospective studies evaluating more limited margins based on high-quality preoperative magnetic resonance imaging and pathological assessment are required.The online version contains supplementary material available at 10.1007/s10151-022-02690-1. Heald et al. popularized the concept of total mesorectal excision (TME) as curative surgical treatment for rectal cancer . In bothPartial mesorectal excision (PME), compared to TME, is a less-extensive surgical procedure associated with less morbidity and better long-term functional outcomes. It has been shown to be associated with significantly lower anastomotic leak rates, increased restorative procedure rate, shorter median hospital stay, less long-term bowel dysfunction and better urinary and sexual function –9. CurreIt is important to have a distal mesorectal margin because of the potential presence of distal mesorectal spread (DMS) of the primary rectal cancer, presenting as mesorectal lymph-node metastases, as vascular or perineural invasion or as tumor deposits. The prevalence and extent of DMS are largely unknown, but these data are prerequisites to define a safe distal resection margin. If oncologically safe, preserving as much as (meso)rectum as possible is preferred for better short-term and long-term functional outcomes –9, 12.The aim of this study was to review the reported pattern  of tumor cells in the mesorectum as a step toward reaching consensus about the distal resection margin for patients with rectal cancer undergoing PME.This systematic review was reported in accordance with the guidance of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist (PRISMA) and A MeaSurement Tool to Assess systematic Reviews (AMSTAR) 2 was used as a critical appraisal tool , 14. Thist 2019) was also used to look for additional references, using the anonymous mode. References of included studies were checked for other eligible studies.Systematic searches were performed from inception in PubMed (up to October 7th 2019) and Embase.com (up to October 16th 2019) with the assistance of a medical information specialist. The full search strategies for both databases are provided in Table Studies eligible for inclusion were studied reporting on the presence of malignant cells in the mesorectum in any form in patients with rectal cancer who underwent radical resection. Studies were excluded if they reported solely the intramural spread of rectal cancer, if they on lateral lymph-node metastases instead of mesorectal spread and if they did not describe the localisation of the mesorectal spread in relation to the primary tumor. Reviews or narrative studies, comment letters or non-human studies were also excluded. In case of studies with suspected overlap of patients, the most recent study was included.www.rayyan.ai) [After removal of duplicates, two reviewers (AG and SvO) independently selected the articles by screening on title and abstract using Rayyan QCRI (yyan.ai) . DiscrepThe Agency for Healthcare Research and Quality (AHRQ) recommends 11 items to assess methodological quality of cross-sectional studies , 17. ThaPrimary outcome was the distance of tumor cells in the mesorectum distal from the rectal tumor. All kinds of malignant spread in the mesorectum, in form of lymph nodes, tumor deposits, direct invasion or lymphatic permeation and extramural vascular invasion (EMVI), were extracted. The participants with DMS were classified in different subgroups depending on characteristics of the primary rectal cancer and whether or not long-course neoadjuvant chemoradiotherapy (CRT) was given. We intended to provide the DMS for every clinical distinct subgroup of rectal cancer based on, for example, TNM stage and tumor height. Low rectal cancer was defined as the lower edge of the tumor < 7 cm from the anal verge and high rectal cancer as a distance of ≥ 7 cm from the anal verge.Data analysis was performed using IBM SPSS Statistics 26. The mean and maximum DMS were calculated and displayed in tables and figures. The mean DMS was calculated only from patients where the distance of the DMS relative to the tumor was reported, so the primary data of the articles were used to calculate the means. In addition, two scatter plots were constructed to illustrate the distribution of DMS per subgroup of rectal cancer.The literature search yielded 2493 records that resulted in 1533 unique articles after removal of duplicates. Thirteen studies were identified by crosschecking references of the included articles. After screening on title and abstract, 94 articles were assessed by full text. A total of 72 articles were excluded by reasons outlined in Fig. The quality assessment is shown in Supplementary Table 1. The AHRQ scores ranged from 0 to 7. Thirteen of the included studies were considered to be of low quality (0–4) , 107–109DMS was found in 207 of the total of 1921 examined specimens (10.8%). In 84 of 207 cases, the distance of the DMS relative to the tumor was reported. The maximum reported DMS was 50 mm, which was found in one of the evaluable 84 specimens .The overall median DMS was 20.0 mm and the overall mean DMS was 20.2 mm. DMS less than 10 mm was reported in 8.3% of the examined specimens, DMS from 10 till 20 mm was reported in 38.1% of the cases, DMS from 20 till 30 mm was reported in 21.4%, DMS from 30 till 40 was reported in 22.6%, and more than 40 mm DMS was reported in 9.5% of the 84 cases . The mean DMS in the low rectal cancer group was 18.5 mm with a range of 8–30 mm.The mean DMS of the high located T3 and T4 rectal tumors was 23.4 mm (range: 10–40 mm). The mean DMS for the T3 and T4 tumors localized low was 18.4 mm with a range of 8–30 mm.Type of DMS was reported in 77 cases. In the vast majority of the cases, DMS comprised a lymph-node metastasis, namely in 65 of the 77 cases (84.4%). The mean DMS in this subgroup was 20.9 mm, with a range of 8–40 mm. In 8 cases, the spread was a tumor deposit (10.3%) with a DMS between 20 and 38 mm, in two cases, there was direct invasion distal to the mesorectum (2.6%) with a DMS of 6 and 10 mm, respectively, in one case, there was lymphatic invasion (1.3%) with a DMS of 8 mm, and in the remaining case, there was both direct invasion and a lymph-node distal in the mesorectum (1.3%) with a DMS of 10 mm.To the best of our knowledge, this is the first report that has systematically reviewed the published data about DMS in rectal cancer. The incidence was 10.8%, whereas the mean reported DMS was 20.2 mm. Using a distal margin of 30 mm would have resulted in residual tumor in 32% of cases with DMS and 10% of the patients with a distal margin of 40 mm would have had residual tumor. The maximum DMS was 50 mm. However, this was only recorded in less than 1% of the specimens with DMS . The available data suggested that DMS increased with higher T-stage. These data imply that a PME can be safely executed if a distal margin of at least 50 mm can be obtained for T3 and T4 tumors, indicating that TME should be performed for tumors located up to 5 cm proximal from the most distal part of the mesorectum as measured on preoperative MRI, see Fig. Tailoring the distal margin based on stage of disease and neoadjuvant treatment has the potential to increase the chance of tumor free distal mesorectal margins, potentially improving functional outcomes. Reducing the distal margin to 1 cm has a risk of residual DMS of 11%, which translates to an absolute risk of 1% given the fact that DMS is only found in 11% of the patients overall in this systematic review. If a distal margin of 2 cm is aimed for, a 32% risk of residual DMS results in an absolute increase of 4% for the whole group. For patients with non-locally advanced disease (T1-3a), these risks may be acceptable, given the balance between oncological safety and functional outcome. It is important to highlight that the data are not robust enough to allow firm conclusions regarding tailoring to specific patients groups, since the DMS is poorly reported.Neoadjuvant CRT has been shown to decrease the number of (positive) lymph nodes available for pathologic assessment , 113. OnSeveral studies have reported distal intramural spread in 5% of TME specimens, and this rarely exceeds 1 cm , 84, 110The current review shows that DMS beyond 2 cm can occur in a proportion of patients. Individual studies showed DMS in 0–30% of patients with rectal cancer , 105, wiOncological safety and morbidity may be inversely related when it comes to the treatment of rectal cancer. On the one hand, morbidity should be kept as low as possible. On the other hand, treatment should be oncologically safe with the lowest chance of LR. Several centers have reported similar LR rates when TME is compared to PME with a 5 cm distal mesorectal resection margin (excluding patients receiving neoadjuvant therapy) , 116–118A good quality of mesorectal excision is not only about the distal mesorectal resection margin. Some studies suggest that the integrity of the surgical plane is more important. Jiménez-Toscano et al. recently found no significant difference in local-recurrence-free survival, DFS and OS between patients with ≤ 10 mm, 11–20 mm, 21–30 mm or ≥ 31 mm distal mesorectal resection margin . In agreThis systematic review has several limitations. First, there are paucity of data in the literature and this combined with the heterogeneity and lack of detail in the existing data in terms of T-stage and neoadjuvant therapy use limits the strength of the conclusions that can be drawn. In particular, DMS is not always included in datasets as an outcome, since routine pathologic examination of the entire mesorectal specimen for individual tumor cells is not standard practice. This could explain why DMS was found in only approximately 11% of the specimens. Second, postoperative MRI data from Bondeven et al. found residual mesorectum in many cases where a formal TME was intended, potentially resulting in underreporting of DMS , 128. A These limitations mean that definite indications about the distal mesorectal resection margin should be in PME, and when a PME is safe or when a TME should be performed, it is not possible. Clearly, there is a need for a properly designed and quality controlled  study to prospectively evaluate the incidence of distal mesorectal tumor spread by precise pathologic assessment, with and without neoadjuvant treatment. This could be combined with a modified Delphi study to determine a core outcome set for pathology and MRI. In the meantime, we recommend a detailed assessment of the preoperative MRI taking into account individual variability in anatomy of the distal mesorectum, combined with a discussion of the balance between oncological safety and functional outcome with the patient, to guide the decision on the level of mesorectal transection in rectal cancer.This systematic review shows that PME is a safe procedure in those patients where a margin of 5 cm can be obtained. The data revealed an incidence of DMS in rectal cancer of 11% overall, which was 1% and 13% with and without long-course neoadjuvant CRT. The maximum reported DMS was 50 mm based on a single case, with a risk of residual DMS of 1% using a 40 mm distal margin and this risk increases to 4% with a 30 mm distal margin. Prospective studies evaluating margins based on high-quality preoperative MRI and pathological assessment are required.Scatter plot with the individual patients with distal mesorectal spread (DMS) per T-stage.Supplementary file1 Scatter plot with the individual patients with distal mesorectal spread (DMS) per T-stage (JPG 40 KB)The mean and maximum distal mesorectal spread (DMS) per level of rectal tumorSupplementary file2 The mean and maximum distal mesorectal spread (DMS) per level of rectal tumor (JPG 61 KB)Scatter plot with the individual patients with distal mesorectal spread (DMS) per level of rectal tumor.Supplementary file3 Scatter plot with the individual patients with distal mesorectal spread (DMS) per level of rectal tumor (JPG 54 KB)Supplementary file4 (DOCX 22 KB)Below is the link to the electronic supplementary material.


Meanwhile, the facile triboelectric sensor made of two annular aluminum electrodes enables the interaction interface to rapidly recognize the multidirectional finger movements. By leveraging the resonant frequency changes of the humidity sensor and output voltage waveforms of the triboelectric sensor, the proposed interaction interface is successfully demonstrated as a game control interface to manipulate a car in virtual reality (VR) space and a password input interface to enter high‐security 3D passwords, indicating its great potential in diversified applications in the future Metaverse.Current noncontact human–machine interfaces (HMIs) either suffer from high power consumption, complex signal processing circuits, and algorithms, or cannot support multidimensional interaction. Here, a minimalist, low‐power, and multimodal noncontact interaction interface is realized by fusing the complementary information obtained from a microelectromechanical system (MEMS) humidity sensor and a triboelectric sensor. The humidity sensor composed of a two‐port aluminum nitride (AlN) bulk wave resonator operating in its length extensional mode and a layer of graphene oxide (GO) film with uniform and controllable thickness, possesses an ultra‐tiny form factor  humidity sensor and a triboelectric sensor, a minimalist noncontact interaction interface with both steady and dynamic responses to finger movements is realized for high‐dimensional interactions. With the capability of detecting multimodal sensory information, the interaction interface is successfully demonstrated as a game control interface and a 3D password input interface. Thereinto, wearable HMIs are the most widely investigated domain technologies due to their unique intuitive, portable, compact, conformal, and low‐cost features .The rise of the Metaverse concept has further increased the demand for various sensory and interactive systems to perform information exchange and mutual interactions between the real world and the virtual world, such as those that can monitor natural environmental factors, human biological and physical signals, and project such information into the virtual environment for a more intuitive, immersive, and real experience.2, 3 These MEMS sensors are able to be integrated into various wearable equipment or with other wearable sensors, exhibiting good integration compatibility, low power consumption, and negligible effect on the flexible and stretchable properties of wearable HMIs. On the other hand, wearable HMIs can be directly fabricated from intrinsically flexible or stretchable materials, e.g., electronic skin, electronic‐textile, wearable patch, etc. To achieve the sensory and interactive functionality, they can be developed based on the sensing mechanisms of piezoresistive, capacitive, piezoelectric, and triboelectric effects. By contrast, the triboelectric and piezoelectric sensors are highly promising for wearable HMIs because of their self‐powered capability, especially when an enormous number of HMIs are required in the Metaverse era. Since the first invention in 2012, triboelectric nanogenerators (TENGs) based on the coupling of contact electrification and electrostatic induction and Maxwell's displacement current, have attracted worldwide interest and been investigated for diverse applications ranging from energy harvesting, self‐powered sensing, to human–machine interactions. Due to the simple configuration, low cost, wide material selection, high scalability, and good compatibility, some studies have combined the triboelectric mechanism with the piezoelectric mechanism to form hybridized HMIs, with enhanced signal multimodality and endowed multifunctionalities.To realize wearable HMIs, two general directions have been widely investigated by researchers to bridge conventional electronics with soft human skins. On the one hand, the traditionally rigid electronics can be miniaturized as tiny islands and integrated on flexible substrates, with stretchable interconnects. In the past few decades, by leveraging the wafer‐level and low‐cost micromachining processes, microelectromechanical system (MEMS) sensors such as inertial and pressure sensors have achieved a huge commercial success.12 The However, these sensors suffer from the drawbacks of high power consumption as well as complex signal processing circuits and detecting algorithms. A potential candidate to address these issues in noncontact HMIs is the triboelectric sensors with the significant advantages of self‐powered capability and facile configuration. The noncontact interaction is achieved through the electrostatic induction between triboelectric sensing elements and charged objects at a remote distance. In this regard, human fingers are ideal for such interactions since they naturally carried with charges after frequent contact with other surfaces during various daily activities. Nevertheless, the fly in the ointment is that the signals from triboelectric sensors are instantaneous and cannot support steady and continuous noncontact response, greatly hindering their applications in certain scenarios. Meanwhile, they normally require a large number of sensing electrodes to achieve multidirectional sensing, which degrades their scalability and integration capability.In addition to wearability, noncontact sensing capability is also another desired feature for the next‐generation HMIs. Recently, we have witnessed a growing interest in wearable HMIs with noncontact attributes, especially during the current pandemic. The noncontact operation of HMIs can effectively reduce the spread of viruses and improve the user experience. Current solutions for realizing noncontact wearable HMIs include optical, radar and ultrasound sensors that can remotely detect human finger motions.48 How especially those nanomaterials‐based humidity sensors. When the water molecules diffused from the surface of an approaching finger are adsorbed by the sensing materials coated on a humidity sensor, the sensor's resistance, capacitance, or resonant frequency will change in response to the approaching of the finger. Meanwhile, the response of the humidity sensor is continuous during the entire process of finger movement, which provides the possibility for noncontact HMIs with steady and continuous responses. Amongst various humidity sensors, MEMS piezoelectric resonant humidity sensors possess the advantages of high sensitivity, high resolution, and wide sensing range with the aid of their surface humidity sensing materials. Moreover, their miniaturized size, low power consumption, digital frequency output, and easy integration make them suitable for use in wearable noncontact HMIs. Whereas, humidity sensor based noncontact HMIs are not ideal for instantaneous finger motion sensing such as finger sliding direction and velocity. Normally a large humidity sensor array is required, which inevitably increases the system complexity and reduces the integration compatibility with other wearable devices. In this regard, multimodality sensor fusion could be a more promising way to achieve simultaneous steady and instantaneous sensing capabilities, compared to the construction of complex and redundant sensor arrays.On the other hand, another promising candidate to overcome these issues is the high‐performance humidity sensors, which have the capability to keenly sense the humidity changes brought by the proximity of human fingers,55 espFigureHerein, by using the complementary sensing capability of the MEMS humidity sensors and the triboelectric sensors, we propose a minimalist and multimodal noncontact interaction interface that can detect steady and instantaneous finger motions simultaneously. The noncontact interaction interface is based on the information fusion of a single MEMS piezoelectric resonant humidity sensor and a facile triboelectric sensor Figure1a. With2Q), higher stability, better power handling ability, and lower detection limit, making them more suitable as the sensing platforms. Common piezoelectric bulk wave resonators are mainly composed of a piezoelectric layer, two electrode layers (the piezoelectric layer is sandwiched between the top and bottom electrodes), and a structure layer, as shown in the inset of Figure Figure2. Different from the single top electrode design of the one‐port resonator, the top electrode of the two‐port resonator was divided into two parts, to reduce the influence of the feedthrough capacitance between resonator signal input and output terminals on the sensor signal strength. The specific mechanism can be illustrated by equivalent circuit diagrams and the electric field (Efield) distribution of the resonators shown in Figure Rm), inductance (Lm) and capacitance (Cm) in the equivalent circuit are associated with the damping, inertia and compliance of the resonator in the mechanical system, respectively. In addition, the capacitance (C0) represents the intrinsic capacitance (feedthrough capacitance) between the signal input and output terminals, which largely attenuates the signal strength of the resonator. For the one‐port resonator, the value of C0 is relatively large, because the top and bottom electrodes arranged in parallel act as the signal input and output terminals, as indicated in Figure Piezoelectric resonators are the key components that determine the performance of piezoelectric resonant humidity sensors. Compared with other types of piezoelectric resonators, such as SAW resonators, quartz QCMs, and cantilever resonators, bulk wave resonators operating in extensional vibration modes have a more compact size, higher quality factor latforms.64 Com64 ComQ To achieve a reproducible performance of the humidity sensors, vacuum filtration was adopted to prepare the GO film with uniform and controllable thickness, in which anodic aluminum oxide (AAO) membrane with large porosity was used as the filter membrane  at the resonant frequency of 10.5 MHz was distinctly higher than that of the one‐port resonator (Q = 811.5), which was beneficial to improve the stability of the humidity sensor during the test.Excited by an external signal, both resonators could generate extensional vibrations along their length direction, as indicated by the COMSOL simulation results shown in Figure 68 To –1 when the humidity changed from 10% to 90%RH. Additionally, no significant signal strength attenuation was observed throughout the test, and the high humidity sensing performance of the sensor was highly repeatable  of the flexible mode affected the stability of the test signal and increased the signal noise level, which is verified by the test results in Figure In addition to the length extensional mode, the flexible mode was another type of vibration mode that can be excited in the two‐port resonant humidity sensor as depicted in Figure 71 Nev3FigureThe dynamic response of the two‐port resonant humidity sensor operating in length extensional mode was then investigated by continuously changing the ambient humidity. For noncontact human–machine interaction, the actual response of the humidity sensors to the humidity changes brought about by the proximity of human fingers is crucial. Figure 4Through the GO‐coated MEMS piezoelectric bulk wave resonator, humidity sensing and noncontact finger interaction were achieved for various monitoring and remote‐control applications. Yet due to the demand for high‐dimensional control, while keeping the interaction interface system lean, a complementary noncontact method was desired to be integrated for more practical and real‐time functionality. Herein, we designed a facile triboelectric sensor with minimalist two annular electrodes and the same noncontact characteristics to enable multidirectional finger motion sensing. On one hand, the triboelectric sensor was able to capture the remote finger motions instantly, facilitating the rapid detection of multidirectional and dynamic finger interactions. On the other hand, the humidity sensor with a steady monitoring ability could be used for detecting the continuous operations of the finger, which was difficult to be achieved only with triboelectric sensors. Thus, with an integrated triboelectric sensor, the resultant interface was able to achieve not only steady and dynamic motion sensing, but also higher‐dimensional signals for more complex controls and interactions.FigureThe proposed triboelectric sensor was constructed with a facile configuration, consisting of only a patterned electrode layer and an interactive Ecoflex ring attached to the fingertip (the Ecoflex ring was only needed in high humidity areas like Singapore). The layout of the patterned electrode is shown in Generally speaking, when the finger slid across single‐electrode patterns (direction 1/1' and 2/2“), outputs were only generated on the respective electrode. If the finger slid across the double‐electrode patterns (direction 3/3” and 4/4“), outputs were generated on both electrodes, with the signal sequence depending on the sliding sequence. Therefore, with different sliding directions, distinguishable output waveforms were produced on E1 and E2 instantly, as depicted in Figure 5With the complementary characteristics and functionalities, the MEMS humidity sensor and triboelectric sensor were integrated with data acquisition modules, a microcontroller unit and a laptop, forming a multimodal sensory and control system for various practical applications. Enabled by the technology fusion of MEMS and TENG, the integrated interaction interface was able to contactless capture multimodal sensory information, including both the dynamic finger motion and the steady finger humidity, for rapid and continuous interactions respectively.FigureTo show the actual capability of the integrated system, car control in virtual reality (VR) space was demonstrated using defined finger interactions. As indicated in −1 (resonant frequency > 10.48 MHz), 30 km h−1 (10.47 MHz < resonant frequency ≤ 10.48 MHz), 60 km h−1 (10.46 MHz < resonant frequency ≤ 10.47 MHz), and 90 km h−1 (resonant frequency ≤10.46 MHz). The moving speed variation and car moving screenshots can be observed in Figure −1, respectively, and when the resonant frequency was higher than 10.48 MHz, the speed of the car returned to 0 km h−1. The demonstration of car control can be found in Video The generated output signals from finger interactions are plotted in Figure 6FigureExcept for the gaming control application, the proposed interaction interface can also realize noncontact 3D password input in a login system. 7In summary, we designed and integrated a humidity sensor and a triboelectric sensor to develop a minimalist, multimodal noncontact interaction interface for various multidimensional control applications. The humidity sensor was designed to recognize continuous and steady command signals during noncontact interactions, while the triboelectric sensor was intended for the identification of fast and instantaneous signals. With the advanced two‐port resonant design and uniform GO film coating, the MEMS humidity sensor successfully achieved high sensitivity, low signal noise, excellent repeatability, and rapid response and recovery speed over a wide humidity range. Benefited by these characteristics, the humidity sensor can be applied for monitoring continuous finger interactions based on different finger‐to‐sensor distances and finger dwell time. On this basis, the triboelectric sensor with a facile two‐electrode design was then integrated with the humidity sensor to realize the complementary monitoring of multidirectional and dynamic finger movements. With this unique complementary information fusion, the proposed noncontact interaction interface was able to provide multimodal continuous and dynamic sensory information for various human–machine interactions with lower power consumption and simpler system structure, as compared with other noncontact HMIs (Table 8The fabrication of the piezoelectric resonators started with an n‐type silicon‐on‐insulator (SOI) wafer  was diluted to 0.02 wt% using deionized (DI) water. Then, 1 mL of the diluted GO dispersion was transferred to the Buchner funnel of the vacuum filtration set up with a pipette. The Buchner funnel was pre‐filled with 150 mL of DI water, and an anodic aluminum oxide (AAO) membrane (Whatman 6809‐5002) was placed below as a filter membrane. After the water in the Buchner funnel was vacuumed out, a uniform GO film attached to the AAO film was obtained. Subsequently, the GO film together with the AAO membrane was placed on the surface of DI water. Under the action of the water surface tension, the GO film gradually separated from the AAO membrane and continued to float on the water surface. Finally, the piezoelectric resonator was immersed in the DI water and lifted up from the bottom of the GO film to complete the GO film transfer.2 flow rates. Meanwhile, the outlet of the chamber was connected to a commercial hygrothermograph (AZ8721) to calibrate the humidity and temperature inside the chamber. The humidity response of the sensor was detected and recorded by a network analyzer (R&S ZNB20) and a PC with an installed LabVIEW program.During the humidity response characterization, the humidity sensor was fixed in a metallic chamber  was poured into a 3D printed mold, solidified to form a belt, and then taken out and fixed into a ring shape with glue  to characterize the sensor's noncontact interaction performance. While during the application demonstrations, the output voltage waveforms were recognized by a programmable Arduino UNO and converted into corresponding control commandsThe authors declare no conflict of interest.Supporting InformationClick here for additional data file.Supplemental Video 1Click here for additional data file.Supplemental Video 2Click here for additional data file.Supplemental Video 3Click here for additional data file.Supplemental Video 4Click here for additional data file.Supplemental Video 5Click here for additional data file.


B is identifiedfor a Jahn–Teller reconstructed V1(5–9) monovacancyin freestanding graphene. For graphene with stable ripples inducedby a compressive strain of 5%, a bond reconstruction produces a V1(55–66) structure for the monovacancy, which is localizedat the saddle points of the ripple. The sizeable local distortioninduced by reconstruction modifies both the geometric and electronicproperties of rippled graphene and quenches the magnetic moment ofthe vacancy due to the sp3 hybridization of the centralatom. The nonmagnetic V1(55–66) structure is foundto be stable on rippled structures, with the formation energy ∼2.3eV lower than that of the metastable distorted V1(5–9)structures localized at sites other than the saddle points. The electronicground state of distorted V1(5–9) corresponds toa wide range of fractional magnetic moments (0.50–1.25 μB). The computed relative stabilities and the electronic andmagnetic properties of the V1(5–9) structures arefound to be closely related to their local distortions. This analysisof the fundamental properties of defective graphene under compressionsuggests a number of strategies for generating regular defect patternswith tuneable magnetic and electronic properties and may, therefore,be used as a novel technique to achieve more precise control of grapheneelectronic structure for various application scenarios such as transistors,strain sensors, and directed chemisorption.The electronic and spintronic properties of the monovacanciesinfreestanding and isotopically compressed graphene are investigatedusing hybrid exchange density functional perturbation theory. Whenthe effects of electronic self-interaction are taken into account,an integer magnetic moment of 2 μ By locally breaking the bipartite symmetryof the graphene lattice, defects may facilitate a precise tuning ofthe electronic and spintronic functionalities of graphene.12Graphene is well knownfor its high carrier mobility,16 and theoretically.20 The monovacancy is generated by removing a carbon atom from thepristine graphene lattice via irradiation of focused electron or protonbeams.16 Following the generation of the monovacancy withthree dangling bonds and C3 symmetry,a symmetry breaking Jahn–Teller reconstruction (JTR) is observed,15 leading to a pentagon-distorted nonagon V1(5–9) structure with C2 symmetry. The monovacancy disrupts the delocalized π bandand may lead to unpaired electron density that potentially resultsin a net magnetization of graphene,19 making ita potential candidate for use in spintronic devices. However, thereare debates over the exact magnetic moment of monovacancy,25 and Rodrigo et al.25 arguedthat it is an artifact that originates from the finite-size effectsin periodic calculations. Although the overall magnetization is usuallyregarded as zero when multiple monovacancies exist in graphene,23 the ferromagnetic hysteresis of proton irradiated graphite is observedat room temperature when an external field is applied.26As the simplest vacancy defect, monovacancy has been widelystudiedboth experimentally29 Strain effectivelytunes the electronic properties of a graphene sheet by changing bothits overall and local geometries. Particularly, large in-plane compressivestrain, which is beyond the Euler-type buckling limit (−0.7to −0.8%),30 can open an electronicband gap by inducing periodic out-of-plane bending, or ripples.29 Strains beyond this limit are experimentallyachieved by confining graphene monolayers in a polymer matrix or adiamond anvil cell.31 However, previous theoreticalstudies have found difficulties that the prediction of ripple wavelengthsis predetermined by the choice of periodic simulation cell.37 The nature of the interplay between monovacancies and strain-inducedripples remains an open question. Some preliminary results have beenobtained by either applying tensile strains25 or under the assumption that the strained graphene sheet is ideallyflat.21 The most noticeable finding isthe strain-induced bond reconstruction of monovacancies, indicatingthe probable existence of novel strain-tuneable properties. The restorationof the pre-JTR structure with three dangling bonds25 and a second-order JTR22 have both beenpredicted to be stable under tensile strains. For compressive strains,Santos et al.36 used density functionaltheory in the generalized gradient approximation [GGA–densityfunctional theory (DFT)] calculations to discover a new bond reconstructionof monovacancies in rippled graphene, which quenches the spin polarizationand suggests that it is possible to switch on/off the magnetizationof graphene by bond reconstruction.Considering its two-dimensional (2D) nature,the lattice mismatchbetween graphene and its substrates, on which it is grown or supported,results in non-negligible strains in practice.40 The distribution of monovacancyformation energies across the rippled sheet is then investigated tolocate the thermodynamically favorable sites of the monovacancy. Themost stable nonmagnetic V1(55–66) structure is identifiedand studied, while the magnetic properties of monovacancies at otherpositions are discussed. This investigation clarifies the origin ofthe inconsistent magnetic moments of a freestanding monovacancy reportedin the previous literature.25 It re-confirms the existence and the essential stabilizing effectof the V1(55–66) bond reconstruction, previouslyreported by Santos et al.,36 now usinga more rigorous a priori approach that determines the ripple configurationsbefore adding the defects. The relationship between the local geometryof monovacancies and the magnetic moment of the system is also exploredin detail. This relationship may offer a practical way to switch on/offthe magnetism of defective graphene by strain engineering. It is alsofound that novel monovacancy patterns can be engineered by applyingcompressive strains, enabling the more precise tailoring of graphenetransistors.In the current work, thetuneable magnetization of monovacanciesin compressed graphene is investigated. Properties of the monovacancyin freestanding graphene are first investigated as a reference. Afterward,the ground state periodic rippled structure of a sheet compressedby 5% in-plane isotropic strain is obtained based on the density functionalperturbation theory (DFPT).243 The HSE06 finite range hybrid exchange functional44 is used to minimize the significant self-interactionerrors inherent in local and gradient corrected functionals in thebroken magnetic symmetry of monovacancy graphene.49 A modified Gaussian basis set for condensed matter calculation 6-21G*,with an optimized exponent (0.26 Bohr–2) of theouter sp-type shell and a d-type shell,50 is adopted. All-electron DFT calculations are performed, so no shapeassumption is made to ionic potential or electron charge density.A 2D periodic boundary condition with an open boundary in the thirddirection (z) is used to model the graphene sheet.The 2D first Brillouin zone of the graphene primitive cell is sampledwith a 24 × 24 k-point mesh generated by theMonkhorst–Pack method.51 This meshexplicitly includes the Dirac point. The sizes of the k-mesh for supercell calculations are scaled to achieve consistent k-point sampling. Mulliken charge analysis is performedto estimate the atomic charge and spin populations. Owing to the semi-metallicnature of graphene, finite temperature Mermin smearing of the Fermisurface is used,52 with a width of 10–4 Hartree. The convergence threshold of the total energyin electronic minimization is 10–8 Hartree per cell.In geometry optimization using the BFGS algorithm, the convergencecriteria are 3 × 10–4 Hartree Bohr–1 for forces and 1.2 × 10–3 Bohr for displacements.The optimized lattice constant is 2.45 Å, which agrees well withthat deduced from X-ray diffraction (2.46 Å).53The calculationsreported here are based on DFT and DFPT as implementedin CRYSTAL17.15 Therefore, the formation energy Ef of a monovacancy is defined as followsThe monovacancy defect studied in this paper is assumedto be chargeneutral, consistent with the experimental observation.Edefect and Epristine are, respectively, thetotal energies of the defectiveand pristine graphene; μC is the chemical potentialper carbon atom in the pristine graphene lattice.z-coordinate in a hexagonallattice, which is summed up to the second nearest neighbors of a givenatomic position 54To quantifythe local curvature of strain-induced ripples, theLaplacian of the atomic ai is the vector pointingfrom the central carbon atom at ith secondnearest neighbor; z coordinates of the central atom and its ith secondnearest neighbor.56 POAV is defined as the specific vector that makes the three angles,θσπ, between the three σ bonds around the central atom and the vector itself equal. The averagehybridization n̅ of σ-orbitals, thatis, 56As a result of its nonplanar configuration,the orbital hybridizationof carbon atoms in rippled graphene is nonuniformly changed acrossthe sheet and depends on the local geometry. The π orbital axisvector (POAV) analysis is a straightforward parameter to characterizethe hybridization of nonplanar conjugated carbon atoms.33.124 In 1(5–9) structure with a remainingdangling bond and a stretched C–C bond of 1.85 Å (plottedin gray). The freestanding defective graphene sheet generally maintainsits original flat configuration. The elongated reconstructed bondof the pentagon introduces significant local tensile strain that dissipatesslowly along the zigzag direction, as indicated by the orange andyellow bonds in The structural, electronic,and magnetic properties of a monovacancy defect in a freestanding6 × 6 graphene supercell, which corresponds to a defect concentrationof 1.4%, are investigated in this section to discuss the origin ofits long-debated fractional magnetic moment. The computed formationenergy of this monovacancy in freestanding graphene is 8.32 eV, whichagrees well with the previous DFT studies on both periodic and isolatedsystems (7.3–8.58 eV).B, which comprises one unpaired electron from the dangling sp2 bond and 1/3 of an electron from each 2pz orbital of the 3 neighbors of the monovacancy.23 The computed magnetic moments of a monovacancyin periodic systems have frequently been reported as fractional valuesbetween 1 and 2 μB in previous studies.57 This was considered to originate from the finite size effects inperiodic calculations and Rodrigo et al.25 suggested that the magnetic moment of an isolated monovacancy convergesto 2 μB using large-scale DFT up to 30 × 30supercell. However, the current study suggests that an alternativeexplanation for the inconsistency lies in the well-known electronself-interaction error of DFT, which is significant for the previouslyused (semi-)local functionals based on local spin density approximation(LSDA) and GGA.58 The consequences of this error have been widely documented in stronglycorrelated systems resulting from the electron confinement that occursin dangling bonds or n-doped systems.62 Pisani et al.45 estimated a significantHubbard U parameter of ∼3.25 eV for grapheneribbons with the GGA–PBE functional, indicating the large self-interactionthat exists in the nonbonding localized orbitals when the πband of graphene is disrupted. For the current system, LSDA and GGAfunctionals may provide a spuriously delocalized charge distribution,leading to incorrect electronic and magnetic ground states. With therange-separated HSE06 functional, the description of the strong on-siteCoulomb interactions is improved,63 andthe magnetic moment of the monovacancy converges to 2 μB within a relatively small supercell. Therefore, it can beconcluded that the self-interaction correction of HSE06 reproducesthe same fundamental descriptions, as those provided by global hybrids47 and more recently developed hyper-GGA functionals.58The monovacancy is spin-polarized due to the danglingbond. Thecalculated magnetic moment of the monovacancy is 2 μ25 with the discrepancy due to the correction for electronic self-interactionincluded here. The monovacancy and resultant magnetic ordering breakthe symmetry of graphene, opening a band gap of 0.31 eV for majorityspin states (spin-up) and 0.06 eV for minority spin states (spin-down).From this, it is clear that if the spins of the monovacancies arealigned, the sheet will be a narrow band gap semiconductor with stronglyspin-dependent transport. In the presence of magnetic defect states,the self-doping of the filled valance band upshifts the Dirac pointin the spin-down band structure by 0.41 eV. Electrons move from theinitially occupied spin-down states near the Fermi surface to thespin-up defect π states.The computed band structure and densityof states (DOS) of themonovacancy are plotted in 64 Results suggest that all the spin-up electrons contributeto the bonding states and are beneath the Fermi level, while all thespin-down electrons contribute to the antibonding states and are abovethe Fermi level. Spin-up states, therefore, stabilize the reconstructedbond. It further supports the conclusion that spin-down π statesdo not cross the Fermi level. Otherwise, electrons will occupy theantibonding states near the Fermi level, leading to a fractional magneticmoment and reducing the stability of the reconstructed system.To characterize the interactionstrength of the JTR bond, the spin-polarizedCOHP curves projected on the two atoms connected by it are plottedin 23 have revealed that the ferromagneticcoupling between the spin localized at the vacancies originates fromthe regular arrangement of monovacancies in the same sublattice. Anantiferromagnetic coupling is generated if monovacancies are accommodatedin the opposite sublattices.In 23 Experimentally, monovacancieshave been generated in graphite using proton irradiation and alignedin an external field with some ferromagnetic hysteresis observed atroom temperature.26 This is consistentwith the high Curie temperatures predicted for idealized theoreticalmodels of the ferromagnetic phases.23Typically, monovacancies in graphenewill distribute randomly betweenthe two sublattices and therefore the net macroscopic magnetizationwill be zero.3.240 is used to compute the harmonicvibrations of the sheet and, thus, to predict the wavelengths of thelow energy strain-induced ripples at 5% isotropic compressive strain.In what follows, positive values denote compressive strains, unlessstated otherwise. The wavelength of strain-induced ripples λcan be predicted by the wavevector k corresponding to the minimum frequency of the soft phonon modesfollowing the relationship of λ = 2π/|k|.40 The wavevector k =  is found to be nearthe minimum frequency (Supporting Information) computed and thus the predicted stable ripples are commensuratewith a 6 × 6 supercell of the primitive graphene cell. Withinthis cell, the harmonic ripple can be induced and then the internalcoordinates optimized to find representations of the stable ripples.Larger ripple wavelengths are predicted under smaller strains . To ensure the overall reliabilityof the current study while keeping the simulation cost feasible, thecase of the 6 × 6 supercell compressed by 5% strain is investigatedin detail, since similar geometries and behaviors are predicted underlower strains with longer wavelengths.40In order to understand the interplay betweenripple formation and monovacancies, we first consider the structureof the low energy ripples. DFPT40 Strain-generated ripple patterns show asixfold symmetry, consistent with the graphene lattice; see Theoptimized geometry is illustrated in 16 the formation energies before and after bond reconstructionare computed. In this way, the energy surfaces, respectively, characterizingthe kinetics ,is shown in the inset. The central atom in red is sp3 hybridized,leading to a slightly flattened tetrahedron and the long sp3 bonds with four neighboring atoms. V1(55–66) issignificantly distorted due to the compressive strain, as characterizedby its local curvature. The twisting angle between the opposite pentagonsis 52.23°, while the angle between opposite hexagons is 54.40°.The dihedral angles of the neighboring pentagons and hexagons arearound 139.66∼139.95°.A detailed analysis of the reconstructed monovacancy at the saddlepoint marked by the dotted magenta circle in 1(55–66) monovacancyis generated,hexagons at saddle points bear the largest local strain (1(55–66), which results in the elongation of some bondsalong this direction. Similar strain relief is not observed alongthe pentagon–pentagon direction, which is vertical to the displacement.Therefore, among the original saddle points, only those along thepentagon–pentagon direction continue to be the regions of strainconcentration. The connection between strain distribution and theformation energy of a site indicates the possibility of mediatingthe monovacancy patterns in the sheet via strains.Before the Vl strain 2. By com1 and an unstrained defectivegraphene sheet .16 Meanwhile, influences of the defect are observed.Partially localized defect states are observed, which is not as evidentas in the case of V1(5–9). In contrast to 1(55–66),owing to the bond reconstruction.The changein local geometry is accompanied by a change in theelectronic structure. The band structure and DOS of the ground stateconfiguration shown in ne sheet 1b. The s1(55–66).Its second nearest atoms from pentagons transfer the most charge toits nearest neighbors, where the largest distortion is observed. Thisphenomenon might be caused by the strong σ-orbital couplingoriginating from the short bonds of pentagons. The charge depletionregion is not as obvious, but more extended, along the hexagon–hexagondirection.The atomic charge populationdistribution is illustrated in 1(55–66), are plotted. Thelargest values are reported at the nearest neighbors of the centralatom due to local distortions, indicating a greater contribution ofsp3 hybridization. n̅ of other atomssurrounding V1(55–66) also exhibit a moderate increase.Atoms in rippled regions have much smaller values when compared withthose around V1(55–66), while atoms at inflexionpoints maintain the pure sp2 hybridization.In 1(55–66) is bonded withfour neighbors; in this case, a pure sp3 hybridizationshould be expected; however, there is a degree of sp2 hybridization,considering the asymmetry of the tetrahedron, as shown in pz orbital, which differs from the curves of the other orbitals,especially in the ±1.5 eV region around the Fermi level. Interestingly,compared with those of px and py orbitals, thePDOS curve of s orbital shows more patterns similar to that of pz orbital, including the absence of peaksin energy ranges of −1.5 to −1 eV and 2 to 2.5 eV, andthe peaks at ∼1.2 eV, which indicates the more significantmixing between s and pz orbitals.The centralatom of Vpz orbitals.33 The partialcharge density projected on the VBM of graphene is shown in 1(55–66)due to its σ-bonded pz orbital. However, the inset shows an almost negligible chargedistribution around it, verifying the conclusion that sp2 hybridization also has a slight contribution. Meanwhile, an enhancedπ-orbital coupling region is observed around the central atom,corresponding to the charge accumulation region in In the flat graphene, the states at VBM are occupiedby electronsfrom the delocalized π-bonded 3.31(5–9)structure, which is metastable when the removed atom is not at a saddlepoint, except for 2 asymmetric V1(55–66) cases (1(5–9) structures are found to be metastable with various distortions,they provide ideal cases for discussing the properties of compressivestrain-mediated V1(5–9) defect. Magnetic momentsvary between 0.50 μB and 1.25 μB for distorted V1(5–9) sites across the 6 ×6 supercell. To understand the origin of these fractional magneticmoments and the stability of distorted V1(5–9) onrippled graphene, a statistical analysis of their local geometriesis conducted. θ is defined as the dihedral angle between thepentagon and the plane of atoms b1, b2 and d. l® is the average length between d and b1, b2 (rS) are calculated betweenlocal geometry parameters and magnetic moments of the distorted V1(5–9), as shown in The JTR leads to a pentagon-distorted nonagon V6) cases 2d. Sinced b1, b2 5a inset.2zrm does not strongly correlate to the magnetic moments.Parameters describing the unsaturated atom d showstronger correlations, which is reasonable considering that the atom d contributes to the unpaired electron. The parameters θand l̅ exhibit strong correspondence  on the overall spin distribution is alsorecently observed in 2D covalent organic frameworks, which is provento be robust at a finite temperature.65 Even though the monovacancy formation energy Ef is not monotonically correlated to the local geometry parametersor the magnetic moment of the distorted V1(5–9), 1(5–9) monovacancies with similar structural parameterstend to possess similar magnetic moments and formation energies.1(5–9)in the same color-shaded region are assumed to possess similar electronicand spintronic properties. To better understand the influences ofdifferent local geometries on the electronic structures and stabilitiesof V1(5–9), three cases, respectively, from theblue , green, and red regions areselected.Considering the similarities mentioned above, V1(5–9) with variousdistortions. PDOS curves  structureand reduces the probability of reconstruction, which is counterintuitivesince V1(5–9) with increased distortion has a lowermagnetic moment and seems to be closer to the reconstructed V1(55–66). However, it is noteworthy that the distortionalso disperses the bond strains across the sheet , while the confined geometry and severe straincondition at saddle points probably limit the displacements and keepthe strains concentrating at the saddle point, which leads to theV1(55–66) reconstruction. Similarly, V1(55–66) deviating from saddle points increases due to the stronger sp3 hybridization of theunsaturated atom. The curve of the most distorted V1(55–66)with medium Ef shows a reverse spin distributionfrom the third nearest neighbor, which originates from the reversedspin orientations of the 2 atoms connected by the JTR bond .The damped fluctuation patterns illustrated in 41(5–9) monovacancy is predictedto have a spin asymmetric conductivity and localized strong ferromagneticcoupling, with a magnetic moment of 2 μB when theelectron self-interaction error is corrected. A periodic “eggbox”ripple pattern generated by 5% in-plane isotropic compressive strainis predicted to minimize the finite size effects inherent in ad hocchoices of supercells. This study finds that the reconstructed V1(55–66) at saddle points of the ripples is the moststable configuration, which forms sp3 bonds and quenchesthe local magnetic moment, with respect to the distorted V1(5–9) observed at the other sites across the rippled sheet.Correlations among local distortions, electronic, and spintronic properties,and stabilities of distorted V1(5–9) are discussed.It is found that more distorted V1(5–9) defectstend to be more stable and have smaller magnetic moments. Accordingto the current study, the switching between spin-polarized and non-spin-polarizedstates of graphene is achievable by the V1(55–66)reconstruction. It can be estimated that this reconstruction doesnot strongly depend on defect density, since only the local distortionsaround a monovacancy determine its stability.The strain-tuneablemagnetism of defect graphene is achieved bythe crucial interplay between monovacancies and strain-induced ripples.The unstrained V1(5–9) or a thermodynamically stable V1(55–66)structure can be obtained. Considering that the substrates are commonlyused to generate isotropic strains in graphene, the practical implementationof this mechanism will depend on finding suitable substrates withmoderate coupling with graphene, upon which the graphene can be strainedwhile being free from the graphene–substrate interactions thatmight interfere in the formation of monovacancies or quench magneticstates. As reported by Zhang et al.,66 structural and spintronic properties of V1(5–9)on the rotationally misaligned topmost layer of chemical vapor depositedgraphite is well preserved and might be a potential candidate forexperimental investigations.In general, bycontrolling the local distortion of a monovacancyvia compressive strains, either a kinetically stable V15 and the influences of thermal fluctuation on ripple configurations.However, it is still noteworthy that the significant stabilizing effect(∼2.3 eV lower in formation energy) of the V1(55–66)reconstruction makes it thermodynamically favorable for a V1(5–9) to diffuse toward a saddle point and to get reconstructedat room temperature if the switching mechanism is followed as usuallyassumed in theoretical studies.67 The hopping barrier decreases as the compressive bond strain increases,57 probably making the diffusivity of V1(5–9) commensurate with the rippled geometry of compressedgraphene. This probably leads to a patterned monovacancy distributionwith long-range periodicity tuned by compressive strains, allowingfor even further modifications of graphene-based electronics.Besides, the stability and diffusionof the generated monovacancyat finite temperatures are still unclear due to the complicated monovacancymigration mechanisms observed in experiment1(55–66)exhibit the predominant increase of the frontier  electrondensity (1(55–66) defects. Thismight enable patterned adsorbate self-assembly and functionalizationat the molecular level, which is important for the controlled engineeringof the configuration and properties of graphene.40Meanwhile, it is also probable for multiple monovacancies to coalescearound the saddle points, where the strain concentrates, leading tothe expansion of the vacancy and the failure of the sheet. On theother hand, neighbors around the central atom of Vdensity 4b,whichIn conclusion, via the interplay between ripple andmonovacancy,the electronic and spintronic properties of graphene can be effectivelytuned to achieve more precise control of graphene, making it a potentialoption for application in various scenarios.


Due to the chaos and confusion caused by the sudden transition from face-to-face teaching to online and remote teaching in early 2020, numerous language teachers had no choice but to rely on online communities on social networking sites. The current study therefore examined how some language teachers were utilising online communities on Facebook during the COVID-19 pandemic. Employing a mixed-methods approach, data were mainly collected through: (1) an eight-month observation of a technology-focused language teacher community on Facebook to identify different types of posts generated by its members before and during the COVID-19 pandemic (n = 340); (2) a questionnaire to understand the community members’ backgrounds and experiences of being in the community (n = 51); (3) semi-structured interviews with some of the questionnaire participants (n = 13); and (4) a post-interview questionnaire (n = 12) to get a better understanding of their responses. A content analysis of online posts and community members’ responses suggest that language teacher communities on Facebook were supporting teachers during the stressful periods of the pandemic professionally and emotionally. The main findings are discussed in terms of the benefits and drawbacks of using online language teacher communities for professional purposes. The overall goal of the study is to offer much-needed answers on how pre-existing communities can be used to assist language teachers in times of a crisis. Many language teachers around the world, including those who were once reluctant to use technology for teaching purposes, were forced to temporarily teach online because of the COVID-19 pandemic , which include SNSs  and semi-structured interviews with some of its members (n = 14), Yildirim  found thWhilst these studies demonstrate that online teacher communities on SNSs bring about various benefits to teachers’ professional lives, the negative aspects should also be noted. Not the least of these is the difficult aspect of sustaining a successful online community, as indicated in a recent study conducted by Nilimarkka et al.  who examAs illustrated in the preceding section, there have been an increasing number of studies investigating the general use of online teacher communities in non-language teaching contexts. However, since language teachers have specific needs in that they need to continuously enhance their professional knowledge, including subject knowledge about a language  and pedagogical knowledge of how to teach language skill areas to learners with different backgrounds using a wide variety of tools and materials, throughout their careers  were about sharing information or resources and 94 posts (27.6%) were about asking for assistance. A content analysis of the 246 posts about sharing information or resources resulted in 11 main categories, which are summarised in Table As shown in Table In three different time periods before the pandemic , the start of the pandemic , and during the pandemic (June 2020–August 2020), both types of posts about asking for assistance and sharing information or resources were found, though the breakdown of the subcategories differed  indicated that they had been using technology in some way in their classes before the pandemic. Out of the 50 questionnaire respondents who claimed that they were using technology in their classes, 44 respondents (88%) stated that the ways in which they used technology changed due to the pandemic. Most of the respondents reported that they used video conferencing tools , Learning Management Systems (LMSs) , or both to teach online. Two of the respondents claimed that the pandemic did not affect their teaching as they had already been teaching online prior to the pandemic.Following the initial questionnaire, semi-structured interviews were conducted with 13 of the community members. It was found that all the interviewees were in two or more language teacher communities at the time of the interview. From the interviewees’ responses, the perceived positive and negative aspects of being in language teacher communities on Facebook during a pandemic were identified.We, as teachers, want to read, we want to learn, we want to expand our knowledge base, but we don’t often have the time to do that. I think, being part of groups like this helps to streamline information a lot better, so if I only have a five-minute break between my classes, I hop on to Facebook and something pops up about something interesting going on in the tech world then that’s my five-minute knowledge boost for the day.Firstly, a few interviewees commented on the convenient and accessible aspect of the online communities. For instance, the following comment shows how language teachers can easily learn through reading the posts shared in the communities in their spare time:.” Some of the interviewees seemed to find the online communities to be particularly important during the pandemic, as indicated in the following comment made by a language teacher who joined a language teacher community on Facebook at the beginning of the pandemic:In the beginning [of the pandemic], it [the online community] was kind of like counselling because everybody else was freaking out and stressed, because they had the pressure of learning new technology themselves… We all relate to each other, so in the beginning it was more like a counselling kind of thing with helping each other, and that was useful.More than a third of the interviewees also indicated that they viewed the online communities as a virtual space to get professional or emotional support. One interviewee explained how she turned to the observed community if she had a question since she believed that “it’s almost guaranteed that someone can help youDeveloping an online course takes a very long time, but we were asked to do it in a matter of weeks with no training… So, I was looking to get insights from not only people who had done this before but also who were in the same situation that I was in.The majority of the interviewees (n = 12) reported that they were suddenly told that they needed to teach online despite not having any experience in teaching online prior to the pandemic. Several interviewees indicated that they joined language teacher communities on Facebook at the beginning of the pandemic. One interviewee claimed that she joined the observed community in April 2020 to connect with language teachers who had prior experience in teaching online as well as those dealing with similar problems:I don’t like getting drawn into these online discussions and debates because it just doesn’t seem like it’s worth anyone’s time, so that’s probably why I don’t actually post much.Although many interviewees reported on the positive aspects of being in language teacher communities on Facebook, a few did express some concerns. Several interviewees reported that they had occasionally witnessed or personally received harsh comments in the communities. One interviewee claimed that she disliked how a member from the online language teacher communities made rude comments to her when she posted a question in the community. In addition, a different interviewee indicated that he was reluctant to post in the language teacher communities on Facebook as he wanted to avoid arguments:Looking on the bright side, one interviewee even claimed that through her experience of being in language teacher communities on Facebook, it has made her realise the importance of online etiquette and safety and tries to teach her students about the importance of how they present themselves online.I have been able to source more tools, techniques and insights from online communities and implemented it into my lesson.In the post-interview questionnaire, which was distributed after the interviews, the interviewees were asked some questions to clarify the information obtained from the interviews. In response to the question asking whether or not their teaching practice had changed as a result of participating in the online communities, nine out of 12 interviewees indicated “yes.” As indicated in the following comment, the interviewee explained how she was able to incorporate what she had learnt from the online communities into her actual lessons:I’ve learned more about online teaching and made use of some of the recommendations that I found in the groups.In a similar vein, an interviewee who did not have much experience in teaching online before the pandemic claimed that participating in the online communities enabled her to learn more about online teaching and directly benefited on what she had learned from the communities:I ended up mostly troubleshooting things on my own. It’s not that I was disappointed in the community I found online, only that I utilized it less than I thought I would when I joined.On the other hand, it should also be noted that a small number of interviewees (n = 3) indicated that their teaching practice had not changed as a result of participating in the online communities. All three interviewees commonly reported in the questionnaire that they were “very confident” in using technology for teaching purposes, and one of them commented that he did not rely much on the online communities during the pandemic because he was able to fix most of his problems alone:From his response, it is evident that not all online community members were heavily making use of the online communities for professional learning purposes.As the primary objective of the study was to uncover how language teachers were utilising technology-focused online language teacher communities on Facebook during the pandemic, in the current section, the ways in which language teachers in the study were affected by the pandemic situation are first described, and subsequently, the main benefits and challenges of using online language teacher communities during the pandemic are outlined.Echoing the findings from the study conducted by MacIntyre et al.  which shThe study’s findings clearly indicated that technology-focused language teacher communities on Facebook brought about numerous professional benefits to language teachers who were suddenly forced to teach online during the pandemic. In line with relevant literature , semi-structured interviews (n = 13), and post-interview questionnaire (n = 12). As lurkers  are a common feature of online communities (Popover & Fullwood, The current longitudinal study provides some insights into the realities of a language teacher community on Facebook during a pandemic. Language teachers in different regions of Japan were providing each other with professional and emotional support in the observed technology-focused language teacher community on Facebook: In particular, when in-person interactions were limited, they were able to support each other through sharing information, resources, and words of comfort and asking teaching-related questions. Without the help from their peers in the communities on Facebook, teachers with no or little experience in using technology for teaching purposes would have struggled even more. Even those who were experienced in using technology benefited from the social aspects of the communities as they were able to socialise with each other in the online social gatherings and related events, which, in turn, helped them overcome their feeling of loneliness and isolation. Although the past two years have witnessed a proliferation of research in crisis management in education (e.g., Back et al., Although it is unclear how language teachers will use the online communities once the pandemic ends completely, they are likely to continuously play an important role in assisting teachers who use digital tools for teaching purposes even in the post-pandemic era. Of course, technology-focused language teacher communities on Facebook will not be a panacea for combatting all the problems that language teachers encounter when they use technology, but it is undeniable that they provide valuable support for teachers, especially when institutional support is lacking.


Cognitive dysfunction, particularly attentional impairment, is a core feature of many psychiatric disorders, yet is inadequately addressed by current treatments. Development of targeted therapeutics for the remediation of attentional deficits requires knowledge of underlying neurocircuit, cellular, and molecular mechanisms that cannot be directly assayed in the clinic. This level of detail can only be acquired by testing animals in cross-species translatable attentional paradigms, in combination with preclinical neuroscience techniques. The 5-choice continuous performance test (5C-CPT) and rodent continuous performance test (rCPT) represent the current state of the art of preclinical assessment of the most commonly studied subtype of attention: sustained attention, or vigilance. These tasks present animals with continuous streams of target stimuli to which they must respond (attention), in addition to non-target stimuli from which they must withhold responses . The 5C-CPT and rCPT utilize the same measures as gold-standard clinical continuous performance tests and predict clinical efficacy of known pro-attentional drugs. They also engage common brain regions across species, although efforts to definitively establish neurophysiological construct validity are ongoing. The validity of these tasks as translational vigilance assessments enables their use in characterizing the neuropathology underlying attentional deficits of animal models of psychiatric disease, and in determining therapeutic potential of drugs ahead of clinical testing. Here, we briefly review the development and validation of such tests of attentional functioning, as well as the data they have generated pertaining to inattention, disinhibition, and impulsivity in psychiatric disorders. Psychiatric disorders affect roughly one in every four people worldwide. Cognitive system dysfunction is a critical factor across diseases, either defining a given condition or closely correlating with functional outcome. Impaired attention is common across many such disorders, including attention deficit hyperactivity disorder (ADHD), schizophrenia, and bipolar disorder (BD) ,2. The lNumerous tests have been developed to assess attention in rodents over the last four decades ,6,7. TheThis limitation of the 5CSRT was partly addressed by the Sustained Attention Task  in mice lacking functional neurokinin-1 receptor (NK1R) ,45, a moTACR1 .O-methyltransferase inhibitor tolcapone, the α7 nicotinic acetylcholine receptor (α7-nAChR) agonist encenicline, and a selective dopamine D4 receptor (DRD4) agonist [TACR1 polymorphisms, the 5C-CPT demonstrates considerable utility in the context of preclinical ADHD research.Other research has utilized the inter-individual heterogeneity of rodent attention to assess the effects of frontline and novel ADHD medications on rats of high and low baseline inattention and impulsivity. This strategy generates cohorts of rats that model the three subtypes of adult ADHD  that demonstrate high levels of pharmacological predictive validity when assessed in the 5C-CPT. Specifically, traditional ADHD therapeutics improved accuracy and overall vigilance in ‘low-attentive' rats and normalized motoric impulsivity and/or response disinhibition  in ‘hig agonist ,53. The  agonist ,51, tolc agonist . Meanwhi agonist ,56, and  agonist . Finally agonist . While fN-methyl-D-aspartate receptor (NMDAR) antagonism rat model of schizophrenia [Pharmacological, genetic, and developmental animal models of schizophrenia have also been assessed in the 5C-CPT. Consistent with patient CPT performance ,58, the ophrenia  reliablyophrenia . Namely,ophrenia , as wellophrenia ,61. Thisophrenia ,30, indiophrenia  aligns wophrenia . Other sophrenia   and ophrenia  (a propoophrenia ). While ophrenia ) or putaophrenia ) schizopenhanced in DAT KD mice [The neural substrates of specifically BD-associated inattention were investigated by assessing patients in the 5C-CPT during manic and euthymic states alongside dopamine transporter knock-down (DAT KD) mice . DAT KD  KD mice . Taken w KD mice . Additio KD mice .In summary, the 5C-CPT is a well-validated, clinically sensitive assay that has already proven useful in: (1) delineating neural mechanisms underlying vigilance; (2) characterizing animal models of clinical populations; and (3) identifying potential therapeutics that can be tested in patients.The rCPT  is a recDespite its reduced capacity to assess response inhibition, the rCPT nevertheless demonstrates validity as an assay of vigilance and impulsivity/disinhibition. Lesion studies have illustrated cross-species convergence in neural substrates underlying response inhibition in the rCPT and the clinic ,83; nameAs with the 5C-CPT, the construct and predictive validity of the rCPT enables its use in the context of preclinical psychiatric research. To date, three studies have utilized the rCPT to characterize the attentional profiles of neurodevelopmental models of schizophrenia and ADHD. Rats exposed to the neurotoxin methylazoxymethanol acetate (MAM) during gestation — a model of schizophrenia-relevant neurological abnormalities and behavioral and cognitive deficits ,91 — demHere, we provided a brief history of the use of rodent behavioral tests developed to explicitly assess sustained attention. It is important to note that while all behavioral tasks require attention to a certain degree , we argue that, without outcome measures specifically designed to assay attention or validation for human testing, the translatability of their findings to human-relevant attention must be questioned. Even the well-validated 5C-CPT and rCPT have limitations. For example, the training time required often precludes the testing of juveniles and adolescents, thus limiting the ability to assess animal models relevant to childhood ADHD, juvenile onset disorders, and prodromal and first-break schizophrenia. Some protocols  may expThe 5C-CPT and rCPT can be readily applied to the study of neuropsychiatric conditions beyond those described above. For example, the underlying mechanisms of Alzheimer's disease and delirium, in which inattention is consistently identified by clinical CPTs ,104 and In summary, current cross-species attention assessments owe a great deal to earlier operant tasks, such as the 5CSRT and SAT; however, while these older tasks remain useful, the data generated by the more recent CPT-like paradigms appear to have greater translatability to humans. The 5C-CPT is well-validated as a cross-species vigilance assay, and is also clinically sensitive and compatible with EEG and fMRI. The rCPT, though yet to be validated in this depth, offers a flexibility in testing that will enable assessment of more aspects of attention. The preliminary neurophysiological construct validity of the 5C-CPT and rCPT represents great promise for future rodent vigilance testing, with the potential for incorporating modern neuroscientific techniques to determine underlying circuit networks and neurotransmitter activity. These tasks, in combination with improved psychiatry-relevant manipulations in rodents, will ultimately facilitate discovery of targeted therapeutics for attentional enhancement.Attentional dysfunction is a critical aspect of many psychiatric conditions, yet few pharmacotherapies exist for the specific remediation of such deficits.Cross-species translatable cognitive assays enable study of the neural substrates underlying attention in humans and rodents at a higher level of resolution than is possible with clinical techniques.The 5-choice continuous performance test (5C-CPT) and rodent continuous performance test (rCPT) measure sustained attention in rodents in a manner consistent with benchmark clinical assessments, and engage similar brain regions across species.The 5C-CPT and rCPT are sensitive to similar pharmacological and parametric manipulations as analogous clinical tasks, and animal models of psychiatric disease tested in these paradigms demonstrate attentional deficits consistent with those observed in clinical populations.The 5C-CPT and rCPT enable identification of novel therapeutic targets and pharmacological interventions for the remediation of attentional deficits.