The quality of follow-up has clearly emerged as a key factor for long-term kidney graft survival. Currently, many clinics are facing difficulties in delivering optimal surveillance because of the increased number and complexity of kidney transplant recipients, and because of the COVID-19 pandemic. Additional ways of performing follow-up visits are needed and telemedicine has emerged as a tool to strengthen patient care intensity. Six Italian transplant surgeons and nephrologists convened via teleconference to develop a consensual model of video visits for the follow-up of kidney transplant recipients. Issues discussed were: profile of eligible patients; assessments that can be carried out; video visit organization and medical professionals involved; supporting tools and implementation. The video visit was consensually recognized as the most relevant for the follow-up of kidney transplant recipients. Eligible patients should have basic electronic devices and the skills to correctly use them and be in clinically stable condition. With the exception of physical and instrumental examination, and kidney biopsy, all other assessments are feasible during a video visit and can be implemented by specific training and use of supporting tools. The video visit model is simple and adaptable to most transplant patients. It is not intended to replace face-to-face examinations, but is an additional tool for improving the intensity of follow-up of kidney transplant recipients, which can be integrated into current monitoring protocols. Kidney transplant recipients need life-long follow-up after transplantation to avoid acute graft rejection and opportunistic infections, optimize renal function, ensure compliance to prescribed treatments, and prevent the long-term complications of immunosuppressive therapy . The recThe healthcare crisis generated by the outbreak of Coronavirus disease 2019 (COVID-19) has further complicated the follow-up of kidney transplant recipients, thus increasing the need for alternatives to conventional face-to-face medical visits. Routine follow-up has become more difficult due to the allocation of resources to the COVID-19 emergency. In addition, the discontinuation of in-person routine medical services for safety reasons and elevated risks for transplant recipients attending medical clinics has further complicated this process , 4. FurtOverall, the quality of follow-up has clearly emerged as a key factor for long-term graft survival , 10 by cPrompted by the increasing organizational burden on transplant and nephrology clinics and the strain caused by the COVID-19 pandemic on the national healthcare system, a board of six Italian transplant surgeons and nephrologists convened in a cycle of teleconferences to discuss the potential of telemedicine for follow-up appointments with kidney transplant recipients. The ultimate goal was to design a consensual model suggesting the “best practice” of virtual video visits, to be integrated into the current management of kidney transplant recipients. Considering current telemedicine regulations in Italy, relevant issues concerning the video visit, the profile of kidney transplant recipients, assessments that can safely be performed remotely, and the required infrastructures, here we report the consensus-based model of video visits.https://www.bipconsulting.com/en-uk/) with expertise in data analysis and modeling for developing patient pathway systems including digitalization. After an initial discussion among the panel of experts to define the main points, the (agreed) results were shared with 25 Italian centers during three boards, to meet a general agreement. The main objective of the scientific board was to explore the potential of telemedicine for the remote management of transplanted patients, and to design the best practice for a telemedicine-based follow-up visit in the form of a video visit. To this end, the advisory board first analyzed existing telemedicine services in Italy. Then, based on published literature and the direct experience of the board members, four relevant issues related to the video visit were discussed: (1) profile of patients eligible for the video visit; (2) potential assessments performed during the video visit; (3) video visit organization, nurse and medical professionals’ training and involvement; (4) implementation of supporting tools.During 2020, six transplant surgeons and nephrologists from six different Italian regions convened in a scientific webinar to address post-operative monitoring of kidney transplant recipients in the current situation of work overload and general healthcare crisis generated by the COVID-19 pandemic. The panelists were selected given their expertise, being either transplant surgeons or nephrologists, directors of the main kidney Transplant Centers in Italy, with additional experience in patient management with telemedicine. Furthermore, the project team was supported by members of the consultancy firm BIP  department and considering infrastructure that is already in place. Issues related to data security and privacy also need to be considered. The set-up for the video visit in the physician’s office should consist of a personal computer integrated with, or connected to, a microphone, audio system, and webcam; a stable Internet connection; and firewall settings that allow access to free software for video-communication. The choice of video-communication software should take the following criteria into consideration: known by the users and widely used in everyday life; free; easy to use; patient registration not needed to participate in the video call; no need for the patients to download any additional software; and document sharing should be supported. The televisit model has been designed by the Expert Panel with the aim of avoiding technical limitations, allowing its implementation regardless of the digital platform, and extending its adoption to as many centers as possible. Should no proprietary platform be in place in the Center, the group suggests the most suitable platform (according to GDPR and other requirements) among those freely available on the market.With regard to security and privacy issues, personal information collected during the video visit is considered equivalent to that collected during a conventional in-person visit and will be treated in accordance with current regulations on the protection of sensitive data. The data protection office and the IT department of the clinic should make sure that the selected video-calling platform manages personal data according to current regulations.The proposed model of video visits for the follow-up of kidney transplant recipients was based on the general structure of a conventional in-person visit and translates most of the medical actions provided by clinicians during such check-up visits into virtual mode. Overall, the suggested real-time video visit appears to be a feasible, adaptable, and easy-to-implement option in the setting of transplant recovery in Italy. This option may alleviate the increasing organizational burden on transplant and nephrology clinics and, at the same time, ensure uninterrupted and timely patient follow-up despite the restrictions imposed by the COVID-19 pandemic and other healthcare crises. The video visit, however, does not replace conventional in-person visits, which continue to be indicated in many cases. Rather, it should be regarded as complementary to current follow-up programs. Importantly, according to current national indications for telemedicine , physiciThe healthcare crisis caused by the COVID-19 pandemic has no doubt contributed to the increased interest in telemedicine. We currently do not know what the role of telemedicine services implemented during the pandemic will be once the crisis is over. As the quality and the services that can be offered via video visit are steadily improving, we expect telemedicine to achieva a stable position in the management of patients with chronic conditions. Concerns have been raised that telemedicine may be precluded to patients who cannot afford the devices and Internet connection required for the video visit. In this respect, we estimate that the savings related to the decreased traveling to the clinic may largely offset the costs of devices and connection.With regard to the selection of kidney transplant recipients who can be adequately followed-up via video visits, we propose involving patients in the age range 18–70 years, with an overall stable condition, low risk of comorbidities, and who have been in a post-transplant follow-up program for at least 12 months, in agreement with current national indications that discourage the use of telemedicine in cases of acute disease and fragility . The sugStudies assessing the feasibility and effectiveness of remote monitoring of kidney transplant recipients are still limited. We currently do not know whether and to what extent the benefits of video visits anticipated in Table As with other approaches of telemedicine and self-care at home, our video visit model requires patients to be actively involved in their follow-up, as they are invited to provide clinical parameters that are easily measurable at home and information about compliance to prescribed medication in a diary. Blood pressure can now be easily measured in non-hospital settings.. Furthermore, the possibility of booking an appointment ensures safety conditions even during the COVID-19 pandemic.BP monitoring at home using Ministry of Health approved medical devices is also an option. At the transplant center, both the patient and a caregiver  are actually trained to use the available validated tools, and are provided with all the information on diet and drug dosage/administration. This may contribute to patient empowerment with a potential benefit in terms of compliance to prescribed therapies and recommended lifestyle changes, improvement of visit quality and patient-physician communication. In line with this expectation, a recent survey among kidney transplant recipients and healthcare professionals conducted in Denmark to evaluate an app and workflow for follow-up found increased collaboration and preparation of patients during the visits and improved dialogue between patients and clinicians .Obviously, the main drawback is the impossibility to perform an “in person” classical examination. The televisit model necessarily implies that the patient is stable. Televisits should be considered as complementary to, and not a replacement for, a face-to-face visit. It is also the physician’s responsibility to recall an outpatient visit any time one is needed on the basis of the patient’s clinical status .All patients must be assessed for eligibility in order to undergo a televisit, and fragile patients  are carefully considered for participation, evaluating the availability of a feasible caregiver. The televisit should be an opportunity to improve the follow-up of a kidney transplant recipient without replacing the onsite visit. Whenever the patient or the physician needs a face-to-face examination, this is discussed and arranged.Moreover, we acknowledge that explicit patient input is missing. However, we underline that in “real life” experience, besides onsite visits, an increasing proportion of patients have additional contacts with the physicians and nurses of the transplant team through phone calls, e-mails and phone text/voice messages. In this view, the televisit represents an organized and privacy-law respectful tool to fulfill the patient’s unmet needs, thus responding to an implicit but obvious input. Indeed, the patient’s point of view and needs were always central during the discussion among the panelists, as all of them have extensive experience and are constantly in touch with the patients, and are thus aware of the main needs and the most important practical issues. The aim of the panel was to first define a consensus model to be further shared with the patients. A second phase of this project is expected and will involve extensive testing of the model in the field, with the opportunity to collect feedback and suggestions on areas of possible improvement both from patients/caregivers and physicians.In conclusion, the video visit model for the remote monitoring of kidney transplant recipients suggested herein is simple and adaptable and should be easy to adopt by transplant and nephrology clinics with some telemedicine infrastructure, as well as by most transplant patients. The video visit is not intended to replace face-to-face visits, but is meant as an additional tool for improving the follow-up of kidney transplant recipients, and to be integrated into current monitoring protocols.


With the development of computer technology, video description, which combines the key technologies in the field of natural language processing and computer vision, has attracted more and more researchers' attention. Among them, how to objectively and efficiently describe high-speed and detailed sports videos is the key to the development of the video description field. In view of the problems of sentence errors and loss of visual information in the generation of the video description text due to the lack of language learning information in the existing video description methods, a multihead model combining the long-term and short-term memory network and attention mechanism is proposed for the intelligent description of the volleyball video. Through the introduction of the attention mechanism, the model pays much attention to the significant areas in the video when generating sentences. Through the comparative experiment with different models, the results show that the model with the attention mechanism can effectively solve the loss of visual information. Compared with the LSTM and base model, the multihead model proposed in this paper, which combines the long-term and short-term memory network and attention mechanism, has higher scores in all evaluation indexes and significantly improved the quality of the intelligent text description of the volleyball video. With the continuous development of big data, computer computing power, and machine learning model, video description technology has set off a research upsurge again. Video description technology is an interdisciplinary research problem. It is an exploration of the expansion of deep learning technology to the field of multidata after making outstanding achievements in the fields of natural language processing, speech recognition, and computer vision . It can With the rapid development of deep learning, researchers began to apply this technology to video description. Current research studies generally use the convolutional neural network (CNN) structure as the encoder to extract visual information and the long short-term memory (LSTM) network structure as the decoder to predict the description sentence . AlthougAiming at the problems of the lack of visual information, syntax error, and strong subjectivity in video description methods in existing video sensors, this paper proposes a method combining the long-term and short-term memory network and attention mechanism to describe the volleyball video. In the first section, the research background and significance of video description are briefly described. The second section briefly describes the research status of the video description of video sensors, discusses the problems to be solved in the current video description methods, and makes a general introduction to the research work and research methods of this paper. The third section first introduces the long-term and short-term memory network and attention mechanism and then gives the application in volleyball video description combined with the long-term and short-term memory network and attention mechanism model. In the fourth section, the datasets for training and testing are selected, and the evaluation indexes of the model recognition effect are determined. Then, a series of control experiments are set up to test the effectiveness of the attention mechanism model combined with the long-term and short-term memory network in the field of video description. The fifth section briefly summarizes the main conclusions of the article.Thanks to the research and development of sensor technology, embedded technology, machine translation, image description, and the expansion of annotated video datasets in recent years, the video description task in video sensors has also attracted extensive attention of researchers, and the research of video description methods has also made great progress .Early video description methods mainly generated sentences based on predefined templates. The sentences describing the video were first divided into several parts, each part should be aligned with the visual content, and then the words detected from the vision were filled into the predefined templates. Kojima et al. selected the most appropriate verbs and objects by detecting the human posture; then, the content displayed by the action semantics is corresponding to the features extracted from the video image, and finally filled the detected syntactic components into common case templates . RohrbacWith the development of the convolutional neural network in the image classification task, three-dimensional convolutional neural network in the video analysis task, and cyclic neural network in the machine translation task, many researchers apply the deep neural network to the video description task. Donahue et al. proposed the long-term recurrent convolutional network (LRCN) model, which can directly generate word sequences through the cyclic neural network without considering the syntax problem of generating description statements . S. VenuTo sum up, although the research on video description methods has made good achievements, there is still much room for improvement in video feature extraction, video timing features, and video multilingual text description. In view of this, this paper describes the volleyball video by combining the long-term and short-term memory network and attention mechanism. By paying attention to the significant areas in the video, the model can quickly identify the target, effectively solve the lack of visual information, and has a good video description effect when the visual sensor processes the volleyball video.ht of step t by relying on the input xt of the current step t and the hidden state ht−1 of time t − 1 of the previous step. In the LSTM unit, the flow of input information of the current step and historical memory information is controlled by the input gating and forgetting gating unit. The calculation method is as follows:As an improved structure of the ordinary cyclic neural network, long-term and short-term memory network (LSTM) can deal with variable input and output sequences and can effectively avoid the problem of gradient disappearance . The LSTσ is the sigmoid activation function, Φ is the tanh activation function, ⊙ represents the point multiplication operation of the vector, and the weight matrix Wij and offset vector bj are trainable parameters.In the formula, x1, x2,…, xn) of a given input video, the conditional probability of the output word sequence  isAiming at the problem of automatic generation of video description, based on the LSTM cyclic neural network, by predicting the feature sequence  to calculate the intermediate hidden state  [X and the output sequence Y is obtained as follows:The LSTM model is based on the encoder-decoder framework, and its structure is shown in 2,…, hn) . In the In the model training stage, the parameters of the model are updated by maximizing the log likelihood probability, i.e.,θ represents the parameters of the model, and the optimization method adopts the random gradient descent method.The encoder-decoder framework combined with the attention mechanism can learn automatic alignment and translation in the training process of the model. When generating new target short language words, it can find the location of relevant source words, and then the decoder combines the content vector obtained from these locations and the generated target words to predict the target words to be generated . The bigi of the decoding process, the content vector ci is weighted by the hidden state sequence  output by the encoder and the attention weight aij:For step aij for hidden state hj is as follows:The calculation method of attention weight eij here is calculated by a feedforward neural network model for automatic alignment:si−1 is the hidden state at the time of decoder t − 1, and the parameters of the a model and other parameters of the translation model are updated through the training process.In the formula, In the task of volleyball video intelligent description, convolutional neural network is usually used to extract image features, and LSTM is used to extract the content vector. The representation ability of the content vector obtained by this method is limited. The attention mechanism can selectively focus on the subset of the video frame sequence to produce the word description of the object or action in the subset of the corresponding frame sequence. Different from the traditional model, the video intelligent description model combined with the long-term and short-term memory network and attention mechanism can dynamically adjust the context vector output by the encoder and realize the function of automatic soft alignment by replacing the convolutional layer and cyclic neural unit layer with the self-attention layer . Its fraAs can be seen from fdC NN2  to represent the visual feature extraction function; then, the sequential multiframe input of a given video isThe visual feature extraction layer uses h,  w,  and c are the height, width, and number of channels of the image, and T is the sequence length. The visual features are extracted for each frame, respectively:In the formula, The visual feature sequence of consecutive frames can be obtained:dfeat is the characteristic dimension. After the visual feature extraction layer, the linear embedding layer is introduced to map the high-dimensional features to the vector of appropriate dimensions for the calculation of the encoder. The calculation method of the embedded layer isXemb ∈ ℝT×dmodel  is obtained, where dmodel  is the vector dimension of the query, key, and value in the process of calculating self-attention weight. The calculation method of the frame position information coding layer is as follows:In the formula, Here is the encoded sequence position information, which can be obtained by artificially setting rules and fixed conversion functions. The position information constructor in this paper isThe trigonometric functions here have different frequencies for features in the same position and different dimensions; for features in different positions of the same dimension, their phases are different. The reason for using the trigonometric function is that the characteristics of the relative position can be described by linear transformation, so it can express the information of the relative position to a certain extent, and trigonometric functions with different frequencies introduce diversified expression of position information.In the model, the self-attention module adopts the multihead attention mechanism. Compared with the dot-product attention, the feature expression ability of this mechanism is more diverse, and its calculation process is (14)headih is the number of “heads” in multiple heads, and WiQ ∈ ℝdmodel ×dq, WiK ∈ ℝdmodel ×dk,  and WiV ∈ ℝdmodel ×dv are trainable parameters. The self-attention module mainly includes normalization, self-attention layer, and residual connection. The forward calculation process of the self-attention module of layer l can be expressed as follows:WQel): this dataset contains 1970 video clips. Each video clip describes a single activity, with a duration of 10 s to 25 s and an average length of about 9 s . This pa  Microsoft Research Video to Text (MSR-VTT): the dataset contains 10000 video clips and 20 video types . Using tThe experiment selects two commonly used datasets for video description generation to verify the effectiveness of the model; they are MSVD and MSR-VTT datasets.In order to objectively represent the quality of text description generated by the algorithm, this paper selects four different objective evaluation methods to test the performance of the algorithm, which are BLEU@4, ROUGE-L, METEOR, and CIDEr. To measure the proximity between the generated description text and the manual description text, the ROUGE-L index tends to calculate the recall rate, the METEOR index is applicable to the field of machine translation, and CIDEr is used to evaluate the quality of automatic image description –27.α with different parameters is selected to compare the performance of the additive fusion module and the attention fusion module. The test results are shown in In order to verify the effectiveness of the attention fusion module, for the MSR-VTT dataset, α are adjusted to about 0.4, but its METEOR and CIDEr scores are still lower than those of the attention fusion module. Therefore, compared with the fixed weight ratio, the dynamic attention weight introduced by the attention fusion module is more flexible in fusing multimodal features and can generate higher quality text descriptions.In order to verify the performance of the video description model combining the long-term and short-term memory network and attention mechanism, this paper implements a mainstream video description model based on LSTM. Except that the structures of the encoder and decoder are different, the evaluation indexes are compared on MSVD and MSR-VVT datasets when other parameters are set close to the same parameters. In this paper, the model with the attention mechanism is recorded as the multihead model, and the model without the attention mechanism is recorded as BiLSTM. The visual extraction layer is recorded as R using ResNet-152 and N using NASNet. The evaluation results are shown in Figures As can be seen from As can be seen from In addition, in the experiment, NASNet, as a visual feature extraction, has greatly improved on the MSVD dataset compared with ResNet-152 and only slightly decreased on the MSR-VTT dataset, which shows that the NASNet pretraining model has a strong generalization ability.k and length penalty coefficients αt on the text quality generated by the model on the MSVD test set. First, control the length penalty coefficient αt = 1.0 to remain unchanged, and change the beam width k to 1, 3, 5, 10, and 20, respectively. The evaluation results are shown in In order to explore the impact of different parameters on the multihead model, this paper explores the impact of different beam widths The evaluation results in The evaluation results in This section is to verify the effectiveness of the multihead model combined with the long-term and short-term memory network and attention mechanism model and compare it with baseline model BaseModel on MSVD and MSR-VTT datasets, respectively. The test results are shown in Figures As can be seen from As can be seen from In this paper, a video sensor processing method combining the long-term and short-term memory network and attention mechanism is proposed for the intelligent description of the volleyball video. The introduction of the attention mechanism can make the model pay much attention to the important areas in the image/video when generating sentences, quickly identify targets, and effectively solve the problem of visual information loss. Through the comparative experiments of different models, the results show that the dynamic attention weight introduced by the attention fusion module is more flexible than the fixed weight and can generate higher quality text description. Compared with LSTM and base model, the multihead model proposed in this paper combines the long-term and short-term memory network and attention mechanism, scores higher in various evaluation indicators, and significantly improves the quality of the intelligent text description of the volleyball video. The model has a strong generalization ability and good performance in the intelligent description of the volleyball video.


Lingual thyroglossal duct cysts can be a rare cause of feeding difficulties in infants. Here, we describe a case of an infant with vomiting and feeding difficulty diagnosed with Hirschsprung's disease. However, she developed an unexpected difficult airway during anesthesia induction due to an undiagnosed lingual thyroglossal duct cyst. Lingual thyroglossal duct cysts can cause abdominal symptoms and difficult airway in infants, while they may be overlooked when stridor is not prominent. A detailed medical history and multifaceted examination are important when stridor worsens. The anesthesiologist then requested the support of a senior anesthesiologist and a video laryngoscope . Fortunately, ventilation improved and SpO2 recovered gradually after the senior doctor provided mask ventilation. However, endotracheal intubation was difficult because the glottis was not visible using a Macintosh curved‐blade laryngoscope (size 0). Successful intubation using an uncuffed tube with an inner diameter (ID) of 3.0 mm was achieved only on the sixth attempt by two anesthesiologists after changing a Macintosh curved‐blade laryngoscope (size 0) into a Miller straight‐blade laryngoscope (size 0) to lift the epiglottis before the video laryngoscope arrived. The surgery was performed as planned, and the patient was transferred to the neonatal intensive care unit (NICU). She was then extubated on postoperative day (POD) 2.Here, we describe a 28‐day‐old female infant  who showed symptoms of poor weight gain due to feeding difficulties and post‐feeding vomiting. It was thought that Hirschsprung's disease was the cause of the gastrointestinal symptoms shortly after birth.3Despite the surgery for Hirschsprung's disease, the feeding difficulty continued, and prominent stridor developed. The first laryngeal endoscopy on POD 8 indicated laryngomalacia. Although, when later reviewed, a slight subcutaneous mass lesion on the anterior side of the epiglottis appeared, it was not pointed out at that time Figure . The patLaryngeal cystectomy was scheduled on POD 27. Based on the published reports,4Congenital laryngeal cysts are rare, with an incidence of 1.82 per 100,000 live births.Laryngeal endoscopy is important for diagnosing lingual thyroglossal duct cyst, but it may not always yield an accurate evaluation of the size of the cyst at the tongue base for crying or moving pediatric patients.Airway management is the most problematic aspect of anesthesia in patients with congenital laryngeal cysts because of the risks of an obscured view of the larynx or cyst rupture during the intubation.In conclusion, a lingual thyroglossal duct cyst is an unusual cause of vomiting and feeding difficulties. Therefore, it may be overlooked in Hirschsprung's disease in patients presenting with gastrointestinal symptoms without airway issues. The learning point of the present case is that lingual thyroglossal duct cysts can be a rare cause of feeding difficulties in infants and that congenital laryngeal cysts should be considered as a possible differential diagnosis in patients whose stridor gradually worsens and is accompanied by feeding difficulties. Therefore, a multifaceted examination is needed in patients whose stridor persists or worsens. In the present case, a video laryngoscope was an effective choice to manage the patient's airway, providing a good field of view to secure a difficult airway in an infant with a lingual thyroglossal duct cyst. The use of a video laryngoscope and supraglottic instruments should have been considered earlier in the first surgery.None.Yoshiki Kohashi performed perioperative anesthesia management, wrote the first draft of the manuscript, and prepared the figures and supplementary video. Tomohiro Yamamoto (Corresponding author) wrote the first draft of the manuscript and prepared the figures and supplementary video. Miki Igarashi helped to write the first draft of the manuscript. Hironobu Nishimaki assisted in the perioperative anesthesia management and helped to write the first draft of the manuscript.None.Written informed consent for publication was obtained from the parents of the infant.Supplementary MaterialClick here for additional data file.Video S1Click here for additional data file.Video S2Click here for additional data file.


The 3 GeV electron storage ring of the MAX IV laboratory is the first light source storage ring that has the inner surface of nearly all the vacuum chambers coated with non-evaporable getter (NEG) thin film. The vacuum and the accelerator performance have proven successful. The 3 GeV electron storage ring of the MAX IV laboratory is the first storage-ring-based synchrotron radiation facility with the inner surface of almost all the vacuum chambers along its circumference coated with non-evaporable getter (NEG) thin film. The coating provides a low dynamic outgassing rate and pumping of active gases. As the NEG coating was applied on an unprecedented scale, there were doubts concerning the storage ring performance. Fast conditioning of the vacuum system and over five years of reliable accelerator operation have demonstrated that the chosen design proved to be good and does not impose limits on the operation. The vacuum system performance is comparable with or better than that of other similar facilities around the world, where conventional designs were implemented. Observed pressure levels are low, and the electron beam lifetime is long and not limited by residual gas density. A summary of the vacuum performance is presented. A linear accelerator (Linac) serves as the full energy injector to the two storage rings and as a driver for a short pulse facility. The nominal energy of the Linac is 3 GeV  lattice. The large number of bending magnets was the main factor in obtaining ultralow horizontal emittance and ultimately achieving ultrahigh brightness, which was a requirement from the machine’s users  cavities operating at 100 MHz and three Landau cavities (LC) operating at 300 MHz. The beam from the Linac is injected into the ring at full energy in the injection straight (Inj) of the long straight section of achromat 01.et al., 2014a).Each achromat has a total length of 26.4 m and contains seven magnet blocks of two types: five unit cells  and two matching cells . Each of the unit and matching cells was machined from a single iron block (Johansson 2.b). The cathodes used in the ion pumps are made of 50% tantalum and 50% titanium (noble diode) to pump noble gases more efficiently and stably. The majority of the ion pumps (77 units) have a nominal pumping speed of 75 l s−1; 20 units are of larger pumping speed as they are installed in the RF cavities and in-vacuum insertion devices.In the 3 GeV storage ring, there are 97 sputter ion pumps installed. In one standard achromat four ion pumps are installed: in the long straight section (IP-L), in short straight section 1 (IP-S1), in short straight section 2 (IP-S2) and on the photon beam path going to the front end in unit cell 1 (IP-U1), as presented in Fig. 22.1.The low natural emittance required (328 pm rad – bare lattice) in a relatively small circumference was realized with a compact design for both the magnet apertures and the distance between magnets.et al., 2014et al., 2014The magnets of the 3 GeV storage ring are small and have an aperture of 25 mm in diameter , is presented in Fig. 4Ten beam-positon monitors (BPMs) per achromat are installed and fastened directly onto the magnet blocks. Bellows with internal RF fingers are located on the extremities of the vacuum chambers (on each side of most of the BPMs). Their main purpose is to shield the BPMs from any deformation coming from the vacuum chambers, as well as to reduce the stress on the vacuum chambers due to heating from synchrotron radiation.2.2.et al., 2001−9 mbar (1 bar = 100 000 Pa) to ensure a long vacuum beam lifetime. NEG coatings are well incorporated in accelerators around the world  yield and a capability of pumping active gases – after activation under vacuum at a relatively low temperature of 180°C  and the MAX IV Laboratory was set up and an extensive research and development programme was accomplished  with no possibility of reactivation. Therefore, those substances must be kept away from the coated surfaces of the storage ring. Appropriate measures were taken to avoid halogens entering the vacuum system of the storage ring, such as the use of fluorine-free pumps and strict acceptance criteria of vacuum chambers for the storage ring and beamlines.NEG films can be permanently contaminated when exposed to halogens  and RF cavities] were manufactured by a single company. This allowed good control of the whole production process, which had the following sequence:(i) Surface treatment of extruded OFS copper tubes (performed at CERN).(ii) Manufacturing of parts.(iii) Assembly of vacuum chambers .(iv) Final cleaning of vacuum chambers.(v) Welding of bellows assemblies at the chamber ends.(vi) Dimensional and vacuum tests.(vii) NEG coating.et al., 2013The same company that manufactured the vacuum chambers also did the coating for 70% of the chambers. The remaining 30% were coated in collaboration with the ESRF  and CERN  under vacuum to at least 180°C, as described by Al-Dmour & Grabski 2017.Test assembly and conditioning of one complete vacuum sector (achromat), excluding the long straight section, was performed off-site in the summer of 2014 with the first set of manufactured and NEG-coated vacuum chambers. A full set of vacuum chambers was installed on seven pre-aligned magnet blocks and supports. First the assembly was pumped down and leak tested. Next, the vacuum chambers were attached to a strongback and lifted to be baked in an oven following the procedure to be used during the final installation. This was done in order to validate the interfaces between the vacuum chambers and the magnets, and to establish and practise the installation procedure.The on-site installation of the vacuum system of the 3 GeV storage ring started in November 2014 and finished in May 2015. The installation procedure for one achromat was as follows  Assembly, pump down and testing of a full achromat on assembly tables, directly above the lower magnet blocks. The achromat was sealed with gate valves at the ends.(ii) Connecting the vacuum achromat assembly (under vacuum) to a strongback and lifting up the achromat.(iii) Baking oven installation around the achromat assembly.(iv) Baking out (at 160°C) and activation (at 190°C) of the NEG coating inside a baking oven, with the chambers hanging from the strongback allowing the assembly to expand freely.(v) Removal of the baking oven.(vi) Leak testing and residual gas analyser spectra analyses.(vii) Lowering the chambers to the assembly tables and adding components that could not be baked .(viii) Lifting up and removal of assembly tables and placement of the vacuum achromat on the lower magnet blocks.(ix) Placement of the top magnet halves.in situ.(x) Once two adjacent achromats were done, the straight in between was installed, baked and activated in situ.The installation process described above took on average two weeks per achromat. There were two teams working in parallel for the installation of all 20 achromats. The RF cavities, injection straight, diagnostic components and insertion devices were baked 4.Each standard achromat of the 3 GeV storage ring has four ion pumps (three on the electron beam path and one on the photon beam path to the front end), one hot cathode extractor gauge (in S1) and one cold cathode gauge (in S2). The extractor gauges provide more accurate and stable readings, and their readings are not influenced by the photoelectrons that are generated by synchrotron radiation impinging on the vacuum chamber walls or absorbers. In addition, some achromats are equipped with a residual gas analyser (RGA) quadrupole mass spectrometer to evaluate the partial pressures. One of the RGAs is located in achromat 8-S1, where the photon and electron beams split. There the radiation fan between the beams is intercepted by an oxygen-free high conductivity (OFHC) copper crotch absorber which is not NEG coated. Another RGA is in achromat 17-L and is mounted where the electron beam path is fully NEG coated. With this instrumentation, it is possible to measure total and partial pressure around the storage ring, but they provide only localized measurements, as the chambers have low conductance.−10 mbar. The pressure in the remaining IVUs is less than 5 × 10−10 mbar.The pressure measured inside the in-vacuum insertion devices is not part of any data presented in this work as it is not strongly dependent on the beam dose. Each in-vacuum insertion device is equipped with a large pumping capacity . In the first two in-vacuum undulators (IVUs) installed in 2016, the total pressure with standard delivery beam current is currently below 2 × 10The vacuum conditioning of the storage ring has progressed well and is evident from both the average pressure reduction and the increase in the total beam lifetime as the accumulated beam dose has increased.As of October 2020, the storage ring had an accumulated beam dose of 3450 A h and the maximum stored beam current was 500 mA. Standard delivery to beamlines is at 250 mA with top-up every 10 min.4.1.−10 mbar. The ion pumps provided an additional pressure indication of 8 × 10−11 mbar. In August 2015 the commissioning of the storage ring started. The first stored beam was on 15 September 2015, which resulted in a pressure increase to the high 10−9 mbar range.The average base pressure (without beam) measured by the extractor gauges before the start of commissioning with electron beam was 2 × 10Pav , as measured by the extractor gauges installed around the storage ring, versus the beam current I at different accumulated beam doses. The measurements took into account extractor gauges installed in all of the achromats excluding several specific locations: achromat 1 (injection dipole kicker), achromats 9 and 15 (unreliable readings), and achromat 20 . The plot in Fig. 5Fig. 5Pav , as measured by extractor gauges , normalized to the beam current ΔPav/I (in units of mbar mA−1) as a function of the accumulated beam dose x (units of A h). The plotted data points were fitted to the following power function: y = 2 × 10−10 x−0.77. From the fit it can be observed that the absolute value of the slope of the vacuum conditioning curve is 0.77. This value is slightly higher than those reported during the commissioning of other storage-ring-based synchrotron light facilities, meaning that the vacuum system of the MAX IV 3 GeV storage ring is conditioning faster. For example, at Diamond the absolute value of the slope was 0.7  versus accumulated beam dose (A h). The increase in the Iτ product is an indication of the beam scrubbing effect, known as vacuum conditioning. The beam lifetime variations at a given level of accumulated dose are due to differences in beam size, bunch lengths and RF cavity settings rather than vacuum related. Typical total beam lifetime during delivery at 250 mA is 25 h.Fig. 7The two points marked in red in Fig. 7Since the start of machine operation, there have been eight main accelerator shutdowns:(i) At dose 22 A h, February to March 2016. Dedicated to the installation of two IVUs for the BioMax and NanoMax beamlines.(ii) At dose 115 A h, July to August 2016. One in-vacuum wiggler (IVW) for the BALDER beamline and two NEG-coated chambers for elliptically polarized undulators (EPUs) for the HIPPIE and VERITAS beamlines were installed.(iii) At dose 232 A h, July to October 2017. Prior to this shutdown no achromats were vented. This shutdown was dedicated to solving issues related to hot spots in the vacuum chambers and to the installation of a diagnostic beamline in achromat 2  At dose 774 A h, June 2018. The neon venting technique was performed and validated as a way of avoiding re-activating the NEG coating by baking, which is usually required after an intervention that includes venting of an achromat. During this shutdown, two achromats were vented with purified neon.(v) At dose 803 A h, July to August 2018. Devoted to the installation of one IVU for the CoSAXS beamline and one NEG-coated narrow-gap vacuum chamber for another EPU for the SoftiMax beamline (no achromats were vented). In addition, all installed 100 MHz RF cavities were vented with nitrogen (the nitrogen flow was maintained during the intervention) to adjust the cavities’ high power feedthrough coupling coefficient to better match the cavity for higher electron beam current operation. The cavities are equipped with gate valves upstream and downstream that were closed during the intervention. After the adjustment, the RF cavities were pumped down with turbo pumps without baking; the pressure recovered to acceptable vacuum level after 2 days.(vi) At dose 1963 A h, July to August 2019. An upgraded version of the MIK chamber, an IVU for the DanMax beamline, a 100 MHz RF cavity and a current transformer were installed in straight sections. No achromats were vented.(vii) At dose 2400 A h, December 2019 to January 2020. No vacuum interventions were performed in the 3 GeV storage ring.(viii) At dose 3190 A h, July to August 2020. The shutdown included adding two new gate valves along the electron beam path to allow fast installation of a future RF cavity, and for this installation one achromat was vented. This was done utilizing the neon venting technique, similar to the one used during shutdown number (iv).After each shutdown, an increase in the average pressure and a reduction in the total beam lifetime were observed. These changes were short-lived and recovery to previous values was quickly achieved.4.3.Given the fact that the RGA in achromat 17-L is mounted in an area where the electron beam path is fully NEG coated, it is believed that the spectra measured by this analyser reflect the gas composition in the majority of the storage ring circumference. The residual gas spectra listed in Table 12 (mass 44) are also observed but at similar levels as with no stored beam.The RGA measurements indicate mainly hydrogen (mass 2) in the gas spectrum. With 170 mA, there is an increase mostly in the amount of CO (mass 28). Methane (mass 16), water (mass 18) and COThe listed partial pressures were obtained by dividing the values measured with the RGA (with sensitivity for nitrogen) by gas correction factors (ionization probability) corresponding to each gas species.5.Due to the scale of the NEG coating of the storage ring vacuum chambers, there was concern during the early stages of the project over the initial conditioning performance, long-term reliability, behaviour under repeated activations and the risk of saturation, and the resulting effects on machine operation and performance. However, from the early stages of commissioning it has been clear that the NEG coating has no negative influence on machine operation, and the vacuum performance was similar to or even better than that of the conventional vacuum systems used in other storage rings. In particular, a beam loss that could be attributed to the coating peeling off was never observed. During production and installation, extensive internal inspections were undertaken. Any chambers showing peel offs or coating damage were deemed unusable and were excluded from the installation.et al., 2013During the production stage, after the chambers were NEG coated, around 15% of the chambers were activated at the supplier’s and collaborator’s premises. This was done to evaluate the coating activation behaviour and to check the sticking factor for hydrogen gas by performing pressure measurements. Similar sticking factor measurements were done at CERN on a few prototype chambers  with standard operating conditions, as presented in Fig. 8The total beam lifetime after injection was 13 h, resulting in a product of beam current and lifetime equal to 2.2 A h. The measured horizontal and vertical beam sizes were 22.2 µm and 9 µm, respectively.During the test, 63 out of the 97 ion pumps installed in the storage ring were switched off. The ion pumps in the RF cavities (12 units), in-vacuum insertion devices (nine units), and diagnostic beamlines and injection straight (13 units) remained on during the test. The pressure was measured using the extractor gauges in short straight 1 (S-1) and cold cathode gauges in short straight 2 (S-2) in every achromat, along with two RGAs installed in achromats 8-S1 and 17-L. The beam current and lifetime during the 3 h period of the test are presented in Fig. 8During the test, several scraper measurements were performed where the electron beam was scraped by movable copper collimators up to fraction of a millimetre from the beam centre. This was done to evaluate elastic, inelastic and Touschek scattering beam lifetimes. During the 2 h period, the total beam lifetime increased due to decay of the beam current, which is the expected behaviour. At 02:55  the beam was topped up to 170 mA.During the test, with the majority of the ion pumps switched off, no unusual decrease in the beam lifetime was observed which could be attributed to a pressure increase. The beam current and lifetime are summarized in Table 2Pressure measurements from the extractor and cold cathode gauges during the test are summarized in Table 3From Table 35.1.1.During the tests described above with the ion pumps switched off, RGA spectra were recorded at two locations in the ring, achromats 8-S1 and 17-L (long straight). Table 4The RGA positioned in 8-S1 is located in a chamber which is not NEG coated along the electron beam path . This chamber hosts the copper crotch absorber, which is also not NEG coated. The RGA which is installed in 17-L is located in an area which is fully NEG coated. This fact contributes to the difference in the gas species observed in the two RGAs.5.1.2.In another test run, the electron beam was dumped from 168 mA to 0 mA, with ion pumps switched off in achromats 3, 4, 5, 6 and 17. The pressures in achromat 4 were recorded by extractor and cold cathode gauges, located in S-1 and S-2, respectively, as shown in Fig. 9−9 (extractor gauge in S1) and 1.4 × 10−9 (cold cathode gauge in S2) mbar for around 1 min, then started to increase to a level of 3.5 × 10−9 and 1.6 × 10−9 mbar, respectively. This might be an indication of the effect of beam-induced pumping – the total pressure in this location (achromat 4-S1) without the circulating beam is higher than that with the beam (with the ion pumps turned off).As presented in Fig. 95.2.Synrad and Molflow+  at S1 locations in the 3 GeV storage ring at a dose of 100 A h with a beam current of 100 mA was 6.2 × 10−10 mbar . However, the measured partial pressure in the storage ring was hydrogen dominant  Insertion devices. Four in-vacuum undulators and one in-vacuum wiggler were installed. The interface to the machine vacuum system was done through cooled copper tapers and bellows on each side of the device. Moreover, three narrow-gap NEG-coated aluminium vacuum chambers of 8 mm internal vertical aperture and around 4.2 m length were installed together with EPUs.et al., 2021et al., 2019(ii) Multipole injection kicker (MIK). In collaboration with the Soleil synchrotron, an MIK has been produced (Alexandre (iii) Diagnostic beamlines (for emittance measurement). The 3 GeV storage ring has two diagnostic beamlines, E1 (achromat 20-M1) and E5 (achromat 02-U5)  Longitudinal cavity kicker (LK) (Olsson (v) In summer 2020 two new gate valves, with a dummy chamber, were added in place of several vacuum chambers in the short straight section S2 of one of the achromats. This was done to reserve space for fast installation of a future RF cavity without the need to vent the entire achromat.7.The two most challenging design constraints of the vacuum system of the 3 GeV ring were the small inner vacuum chamber apertures, with no place for lumped pumps and absorbers and the requirement for an NEG coating. These two aspects posed limitations on the installation and operation.7.1.An installation protocol was prepared and followed up for each installed achromat. As a result, the installation went smoothly and on schedule, with only minor issues to report.7.1.1.All the coated chambers were visually inspected before installation to check for non-conformities. The two main problems with the NEG coating were:(i) Uncoated areas of the vacuum chambers. When the area of the uncoated part was small (less than a few square centimetres), the chamber was installed ]. These RF finger and copper end-piece assemblies were replaced with newly manufactured RF fingers without an NEG coating. A few chambers had peel offs at the edges, and those chambers were discarded from the installation and replaced with spare units to continue installation [see Fig. 11b)]. From around 650 NEG-coated vacuum chambers installed in the storage ring, only a few chambers were discarded during installation due to coating peel off that could not be remedied. The chambers that could not be installed due to coating issues constitute less than 1% of the total manufactured chambers. This issue could be avoided by thorough visual inspection of the chambers far ahead of installation.(ii) Peel off. The majority of the peel offs occurred in the RF finger assembly welded to the chamber ends. The RF fingers were requested to be shielded from the coating but were unnecessarily NEG coated [see Fig. 117.1.2.One edge-welded bellows was damaged during the manipulation (lifting/lowering) of the achromat. Excessive torsion was applied to the chamber and the convolutions of the bellows at one end were deformed  but are high enough to trip the vacuum interlock and dump the beam.A few limitations were encountered during machine operation. In the 3 GeV storage ring, the vacuum chambers directly intercept the dipole synchrotron radiation, so the temperature of the vacuum chambers is monitored by thermocouples glued on the vacuum chambers in critical areas (around 30 thermocouples per achromat). On several chambers, the recorded temperature level during operation was higher than simulated. A few hot spots were identified and investigated. The causes of such problems are summarized below:(i) Positioning of the vacuum chambers. Some vacuum chambers  were not positioned correctly due to geometric non-conformity or deformation. Consequently, the beam was striking areas that are not designed to intercept the beam. Once alignment of those was performed, the hot spots were eliminated.(ii) Chamber non-conformities. After installation, some crotch absorbers  did not shield the radiation fan in the correct spot. The straightness of the chambers and some tolerances did not meet the technical specifications defined on the drawings. In some cases, the absorbers were exchanged for longer ones, and in other cases, finite element analysis was performed to check if the chambers could tolerate the additional heat load. If the non-conformance was found to be safe, no further action was taken.a). When the magnet in that location was closed, it pressed the chamber through the glued thermocouple and caused deformation of the chamber. As a result, the photon beam was heating up the deformed area which is shown in Fig. 13b). This imposed a limitation on the beam current and the use of one insertion device where the photon beam could cause excessive heating. These problematic chambers were exchanged in three achromats during the third shutdown in 2017. After the chambers had been exchanged, the achromats were baked and the NEG coating was re-activated, and this action resolved the issue.(iii) Deformed chambers during installation. Thermocouples were glued with epoxy in selected locations that were considered critical. On a few vacuum chambers, a thermocouple placed in the vicinity of the photon beam extraction was mis-positioned and glued with an excessive amount of epoxy, as illustrated in Fig. 138.Up until spring 2018, the procedure that was followed for any intervention related to venting of vacuum chambers in the 3 GeV storage ring, that are located within an achromat, was similar to that during installation:(i) Vent the achromat and the two adjacent straight sections and disconnect the two straight sections.(ii) Open all top magnet halves.(iii) Connect the vacuum chambers to the strongback and raise all the vacuum chambers.(iv) Install assembly tables over the lower magnet blocks and lower the achromat onto the assembly tables.(v) Exchange the faulty chamber, pump down and leak test.(vi) Raise the achromat, install the oven, and perform the bakeout and activation of the NEG coating.(vii) Remove the oven and lower the chambers onto the assembly tables, and install non-bakable components to the vacuum chambers.(viii) Raise the achromat again and remove the assembly tables.(ix) Lower the achromat back onto the lower magnet blocks.(x) Close the magnet blocks, reconnect all the water and electrical systems and check alignment.in situ the NEG coating in the long straight sections.(xi) Connect upstream and downstream long straight sections to the achromat, and bake and activate For one achromat, this procedure would take two weeks, and up to four weeks in cases where the insertion devices were installed in the adjacent long straight sections. Such a procedure is lengthy and includes risks during the manipulation of the chambers and the opening of the magnets.MAX IV looked at other alternatives which could reduce the time of intervention, reduce the risk and simplify the procedure. This could be achieved by venting the vacuum system using ultra-pure neon gas, therefore limiting the saturation of the NEG film during the intervention and thus avoiding the need to bake and re-activate the coating.et al., 2011The neon venting procedure was used for activated NEG-coated vacuum chambers at CERN for interventions in the LHC long straight sections and detector chambers. The main idea behind the procedure is to avoid saturating the NEG coating during the intervention. Neon was used as it is an inert (noble) gas, thus is not pumped by the NEG coating, it has relatively low atomic mass (interacts less with the electron beam) and does not affect leak detection (for leak detection helium and argon are used). During such intervention, ultra-pure neon is used for venting and is kept at slightly above atmospheric pressure inside the chamber. When the chamber to be exchanged is removed, the flow of neon is sustained, which prevents atmospheric air from back streaming to the inside and saturating the NEG coating, thus eliminating the need for baking and re-activation of the film . There the reading was two orders of magnitude higher, but recovered to the value before the intervention after around 50 A h of beam conditioning.−13 mbar mA−1. Following the intervention and after 1 A h of operation, this value increased to 2.4 × 10−11 mbar mA−1. However after 18 A h of beam conditioning it reduced to 1.2 × 10−12 mbar mA−1, as presented in Fig. 14The normalized average pressure rise before the intervention was 9.3 × 108.2.The total beam lifetime before the intervention was between 3 and 5 A h. Just after the intervention (after a dose of 1 A h), this value reduced to 1.2 A h, and during the first 10 A h of beam conditioning the lifetime increased back to the original value from before intervention (3.8 A h), as shown in Fig. 158.3.Two new RGAs were installed without bakeout in the places where the chambers were replaced. After the intervention, and without the electron beam, neon peaks (mass 20 and 22) were evident in the scans at those two locations. With the first stored beam, the partial pressure of neon gas increased by one order of magnitude close to the intervention areas. After 18 A h of beam conditioning, the neon partial pressures dropped by one order of magnitude (with beam) without any limitation on the accelerator operation and beam delivery to the users. No neon peaks were observed in the other RGAs around the machine, with or without stored beam.8.4.During the eighth shutdown in summer 2020, two new gate valves were installed in short straight section S2 of one of the achromats in place of straight vacuum chambers, reserving space for future fast installation of an RF cavity. In order to add the two new gate valves, the achromat needed to be vented and a few chambers replaced. To reduce the intervention time a similar neon venting procedure to the one used in 2018 was developed, although in this intervention longer chambers were replaced than in the previous intervention of 2018. Both of the chambers to be installed had gate valves preinstalled at one end. The chambers were baked and the NEG coating was activated before installation. This approach was chosen to reduce the saturation of the NEG coating of the installed chambers to a minimum. The intervention procedure was rehearsed several times on a mock setup before the shutdown to ensure smooth execution. The final procedure for the intervention was as follows:(i) Two short NEG-coated vacuum chambers were prepared. One gate valve was mounted on each chamber and the all-metal neon venting system was connected with a flexible hose. Both chambers were baked and the NEG coating was activated. These chambers were kept under vacuum, together with the attached neon venting system, until the installation time.(ii) Prior to the intervention two neon stands were pumped down and their NEG filters were conditioned. The NEG filters are part of the neon venting system and used to purify the injected neon gas from unwanted residues that it may contain.(iii) Two days before the intervention, the two neon stands were connected through right-angle valves to short straight section S1 of the achromat to be modified and long straight section L of the next achromat. The two connection places were pumped down and baked with two additional pumping stations.(iv) On intervention day the achromat was vented with neon from both sides: S1 (upstream S2) and L of the next achromat (downstream S2). The neon flow was sustained while the vacuum chambers were removed from short straight section S2.(v) The new upstream chamber with a gate valve was vented with neon from the gate valve side and a flow of neon was established. After the chamber had been installed on the upstream side, the new gate valve was closed and the neon flow from the upstream achromat side was stopped. The upstream part of the achromat was pumped down from short straight section S1.(vi) The new downstream chamber with a gate valve was vented with neon from the gate valve side and a flow of neon was established. After the chamber had been installed on the downstream side, the new gate valve was closed and the neon flow from the downstream achromat side was stopped. The downstream part of the achromat was pumped down from long straight section L of the next achromat.−9 mbar and the ion pumps were switched on.(vii) After approximately 24 h of pumping, the pressure measured by the extractor gauge in the upstream side (S1) was 1 × 10−10 mbar, which was around 10% higher than before the intervention.(viii) After 4 d, the pumping stations were disconnected and the right-angle valves closed, and the pressure at measurement location S1 was 4 × 10in situ following the standard procedure.(ix) In the place between the two newly installed gate valves (S2), a dummy straight vacuum chamber was installed with tapers and an ion pump. It was pumped down and baked and the NEG coating was activated The time from the start of the venting of the achromat until the start of the pumping down with the newly installed chambers and gate valves was approximately 1 h.After the shutdown had finished, the beam lifetime was recovered to a nominal value of 5 A h with a beam dose of several A h. The intervention did not have any negative impact on the operation of the storage ring. This can be observed in Figs. 69.The vacuum system of the 3 GeV storage ring of MAX IV is unique, considering the small aperture of the vacuum chambers, the extent of the applied NEG coating and the low number of ion pumps and crotch absorbers.x−0.77, where x is the accumulated beam dose) and this is slightly better than what has been observed in other synchrotron light facilities, 0.7  of the vacuum conditioning curve presented in Fig. 6There were no operational issues related to the NEG coating, which shows this technology to be reliable and effective in ensuring low dynamic pressure. Initial concerns with the risk of saturation of the NEG in the early stages of commissioning when pressures are high has proven not to be an issue. The same is true regarding the risk of the coating peeling off and affecting the beam lifetime. Finally, after five years of operation and several interventions including reactivations in a number of achromats, the long-term robust performance of a nearly 100% NEG-coated accelerator vacuum system is well established.A few issues with hot spots on the vacuum chambers were the main obstacles encountered during vacuum system conditioning. However, the impact on machine operation was minor.The maximum design current of 500 mA was achieved in November 2018 and the total beam lifetime reached 5 A h after an accumulated dose of approximately 100 A h.The use of neon venting (on two occasions in 2018 and 2020) as the procedure to be followed for vacuum interventions that involve replacing vacuum chambers and components significantly reduced the intervention time and possible risks associated with splitting magnets and reactivating the NEG coating. This procedure has a negligible effect on the machine performance, and proved to be efficient and robust.


Zero separation is a family-centred approach where newborns should be accompanied by their parents, regardless of the type of birth or health status. To our knowledge, few studies have described the way this approach is realized in clinical practice. This study describes situations of separation between mother/partner and newborn after birth on the labour ward, maternity ward and at the neonatal unit.An observation study was conducted during four months at a Swedish hospital. All caregivers at the three units were given the task of collecting the data. A semantic thematic analysis was performed with an inductive approach.Six themes emerged from the analysis. Two themes were common to all three units, one theme was common to two units and three themes emerged at only one unit. The themes describe various causes of separation, such as organizational and economic barriers, clinical routines, parents’ own decisions, shortage of collaboration within and between units, as well as a shortage of interprofessional communication.Our study shows that there is still a gap between the latest evidence-based knowledge of the importance of zero separation and current practice in newborn care. There is a need for continuous collaboration between all units responsible for the care of mother and newborn. The first hour of life is an important and meaningful period and, in the literature, it is often referred to as the “golden hour”, “sacred hour” or “magic hour”.At the moment of birth and during the hours and days that follow, mothers and newborns have a physiological need to be together. Keeping mothers and newborns together is a safe and healthy birth practice Bergman, . Skin-toWhen the newborn is placed skin to skin with the mother, there is a significant increase in oxytocin, which will reduce maternal and newborn stress and help the newborn transition topostnatal life  were given the task of collecting the data, i.e., situations of separation between mother/partner and newborn. Prior to the data collection, a team of members from each unit was set up and several meetings with all caregivers were organized. At these meetings, information, and a deeper understanding of the importance of skin-to-skin contact and the correct definition of zero separation were given, as well as information about the protocol for data collection. Regular meetings were organized between the team members. A team of members from each unit was organized with the aim of supporting other caregivers to observe, even at times when there was a heavy workload.A protocol common to all the units was designed and used for each observation. If a separation between mother/partner and newborn was observed by the caregivers during care after birth and at the hospital stay. These situations were then documented in the protocol in the caregivers’ own words in a narrative way. The whole data material consisted of free-text material. The observations were made on all working shifts (day/evening/night). During the four months, 197 observations were collected, 54 observations from the labour ward, 103 observations from the maternity ward, while 40 observations were collected from the neonatal ward. The caregivers simply observed the situations of separation, without interfering or directing the action in any way.A semantic thematic analysis was performed using an inductive approach  inclusive maternity clinic to create a chain of care that contributes to mother and newborn togetherness.


There is mixed evidence regarding whether video games affect executive function. The inconsistent results in this area may have to do with researchers’ conceptualizations of executive function as a unified construct or as a set of independent skills. In the current study, 120 university students were randomly assigned to play a video game or to watch a screen record of the video game. They then completed a series of behavioral tasks to assess the shifting, updating and inhibiting subcomponents of executive function. Scores on these tasks were also used as indicators of a component-general latent variable. Results based on analysis of covariance showed that, as predicted, the inhibition subcomponent, but not the updating or the shifting subcomponent, was significantly enhanced after gaming. The component-general executive function was not enhanced after gaming once the results were controlled for other subcomponents. The results were unrelated to participants’ self-reported positive and negative affect. The findings add key evidence to the literature on executive function and potentially contribute to the therapeutic use of video games to maintain executive function in the aged population. Touchscreen video games are now part of the daily lives of many people, a large number of whom play on smartphones or tablets. The number of video game players worldwide reached 2.60 billion in 2020, with average weekly gameplay hours ranging from 6.69 to 7.98 across countries . StudiesMany studies have shown a positive correlation between video gaming and EF. Long-term training-based studies ,7,8,9 haHowever, other studies have found only partial benefits or negative effects of video-game playing on EF. For long-term video-game training, Ruiz-Marquez et al.  reportedThe conflicting results regarding the effects of video-game playing on EF may be due in part to whether EF is conceptualized as a unitary construct or as a set of independent skills. Wang et al.  defined In early attempts to subdivide EF, Miyake et al.  proposedSuper Mario video game. However, in general these studies assessed the subcomponents of EF without attention to an overall EF construct. One exception was Eggenberger et al.  = 1.015, p = 0.312, Cohen’s d = 0.185) or negative  PANAS scores at the beginning of the experiment. Neither PANAS score was significantly related to any of the EF task indicators, rs ≤ 0.136, ps ≥ 0.140. Within the experimental group, no significant correlations emerged between ratings from the post-game questionnaire and EF task scores, rs ≤ 0.218, ps ≥ 0.094.The experimental and control groups did not differ in positive , inhibition  and updating  reached statistical significance. Descriptive statistics for the scores of inhibition, shifting, updating and the common EF are shown in The correlation matrix underlying the latent variable modeling was presented in p = 0.032, η2 = 0.033) but (2) not the shifting component  or (3) the updating component . (4) The between-group differences of the common EF  did not reach significant levels.In support of our hypothesis, significant between-group differences were observed for the (1) inhibition component  = 4.985, p = 0.027, η2 = 0.041. The common EF in this study was extracted from three measures. It may be controversial whether inhibition should be controlled when analyzing the common EF. The more tightly controlled result was selected for this study, and no significant group differences in common EF were reported.The present study found that inhibition ability could be improved after short-term video games, consistent with previous results ,31. As aA touchscreen game was used instead of a computer game in this study because the mobile phone with a touchscreen interface is currently the primary carrier of video games. In China, there were 640 million video game players in 2019, 620 million of whom were mobile-phone gamers . WorldwiAs video games, especially mobile games, are enjoyable and easy to access, various populations may be motivated to play them . BrieflyThe current study examined component-general and component-specific EF factors simultaneously after young adults played a brief touchscreen video game. The results showed that video game playing significantly improved inhibition ability. The results suggest the potential therapeutic applications of video games.


Cognitive and behavioural outcomes in stroke reflect the interaction between two complex anatomically-distributed patterns: the functional organization of the brain and the structural distribution of ischaemic injury. Conventional outcome models—for individual prediction or population-level inference—commonly ignore this complexity, discarding anatomical variation beyond simple characteristics such as lesion volume. This sets a hard limit on the maximum fidelity such models can achieve. High-dimensional methods can overcome this problem, but only at prohibitively large data scales. Drawing on one of the largest published collections of anatomically-registered imaging of acute stroke—N = 1333—here we use non-linear dimensionality reduction to derive a succinct latent representation of the anatomical patterns of ischaemic injury, agglomerated into 21 distinct intuitive categories. We compare the maximal predictive performance it enables against both simpler low-dimensional and more complex high-dimensional representations, employing multiple empirically-informed ground truth models of distributed structure–outcome relationships. We show our representation sets a substantially higher ceiling on predictive fidelity than conventional low-dimensional approaches, but lower than that achievable within a high-dimensional framework. Where descriptive simplicity is a necessity, such as within clinical care or research trials of modest size, the representation we propose arguably offers a favourable compromise of compactness and fidelity. The first is the functional anatomy of the brain focal ischaemic injury definitionally disrupts, now comprehensively established to be not only highly complex but also remarkably consistent across individuals: meta-analytic imaging databases would otherwise be filled with noise, not generalisable clusters of coherent activation , practicable (easily implemented), and reproducible (replicable across time and context). Second, to enable robust, objective comparisons between related instances—especially in observational and interventional studies—where a paucity of variables improves statistical power and generalisability by reducing the risk of overfitting  with a clinical diagnosis of acute ischaemic stroke confirmed by diffusion weighted imaging (DWI). Since DWI was routinely performed on the majority of attending patients, the sample was representative of the population, constrained mostly by contraindications to and tolerability of MRI. Age ranged from 18 to 97 years, mean 63.89, standard deviation 15.91; the proportion of males was .561; ethnicity was representative of London . The inc2.22.2.12 that is relatively insensitive to acute ischaemia but shows reasonable tissue contrast, and an image with a b value of 1000 sec/mm2 that is sharply sensitive to ischaemia but has poor normal tissue contrast. This complementarity can be exploited to achieve both good lesion segmentation—which depends on the contrast between lesioned and normal tissue—and good brain registration—which depends on the contrast between normal tissue types. Note that the spatial scale and contrast-to-noise ratio of diffusion weighted imaging in the context of lesion modelling is such that instrument variability has plausibly little impact on the analysis. This is reflected in the widespread use of instrumentally heterogeneous imaging in lesion studies.All acquisitions were performed on scanners manufactured by General Electric (Genesis Signa), Philips (Achieva and Ingenia), or Siemens  with field strength of either 1.5 or 3 T. This diversity reflects changes in routine clinical practice over the period of data collection rather than differences in individual indications. All scans were obtained as part of the clinical routine, employing clinical protocols. We extracted from each imaging study the echoplanar DWI for lesion segmentation and inter-subject registration. DWI is widely used to detect and locate acute ischemic lesions . In its 2.2.2http://www.fil.ion.ucl.ac.uk/spm/software/spm12/) were used to co-register each b0 and b1000 pair, derive from the b0 a non-linear deformation field to MNI space and apply it to the b1000  rather than the raw data, with a perplexity setting of 30 (r = .1).To derive a two-dimensional representation we applied ng of 30 ). The rang of 30 —is that ng of 30 , regularFinally, the resultant two-dimensional representation was discretized by Ward hierarchical agglomerative clustering into a categorial representation. The choice of clustering algorithm was motivated by the natural hierarchical structure of the vascular tree, and by the absence of any requirement to specify the desired number of clusters J. . We chos2.3.1To investigate the potential capability of other techniques for reducing dimensionality to the initial, two-dimensional succinct representation, we replicated the preceding processing pipeline with the substitution of Principal Component Analysis (PCA) alone, PCA followed by t-SNE, Uniform Manifold Approximation and Projection (UMAP)  alone, P2.3.2we must fix the first by positing a hypothetical lesion–deficit map. Otherwise performance estimates will be unquantifiably and unpredictably distorted by error and uncertainty in the underlying real-world relation between lesions and their associated deficits.Our objective is to quantify the potential utility of our lesion representation in predicting patient functional outcomes. Predictive performance here depends on two interacting factors: the underlying lesion–deficit relation, and the capacity of the lesion representation to make use of it within discriminative models used to forecast future outcomes. Since our interest here is in the second of these two factors, The posited hypothetical lesion–deficit mapping must nonetheless be biologically plausible. It must also afford coverage of the entire brain, for generalisation from one anatomical region to another cannot be assumed. Finally, more than one map is desirable to reassure us the result is not an accidental artefact of the specific choice of ground truth.http://www.mccauslandcenter.sc.edu/mricro/index.html). These maps included Brodmann areas implicated in visuospatial neglect (BA 39/44), picture naming (BA 37/38), sensorimotor areas  and their underlying white matter as specified in Chris Rorden's widely-used template distributed with MRIcro (opted by ), visualopted by  , faciliopted by , analogoopted by .The second set of maps exploited Schaefer's recent whole brain parcellation based on resting state functional MRI data , combine2.3.3The foregoing lesion–deficit maps enabled us to define a lesion as being associated with a deficit or not, for each of the given functionally informed anatomical networks, yielding a ground truth against which predictions with models employing different lesion representations could then be tested. Four different representations were evaluated. The simplest, “Baseline” representation was constituted of the age of the patient and the volume of the lesion. The next two representations were based on age and lesion volume as well as our low dimensional embeddings: the Ward cluster membership of the lesion , and the two-dimensional t-SNE coordinates (”2D”). The final representation was the 50-dimensional NMF decomposition (”50D”). Note the purpose of the 50-dimensional representation is to provide a high-dimensional contrast far removed from plausible intelligibility rather than to establish the maximum achievable within a model unconstrained in its input dimensionality. Such a maximum would depend not only on the representation but also on the optimality of the predictive modelling architecture and its tuning, and its supportability by the available lesion data, making it hard to draw any conclusions about the marginal contribution of the representation itself: the focus of our study. We therefore did not explore higher-dimensional models, including those operating at voxel level.Though low-dimensional, these representations do not linearise the relation to hypothetical deficits. We therefore chose a flexible, non-linear architecture for predictive modelling: gradient boosting machines (GBM) J. H. . For eac2.4The recommended approach to quantifying the robustness of differences in predictive performance achievable with the four different representations is by cross-validation 95% confidence intervals on the balanced accuracy and AUROC measures: this is standard in the evaluation of complex multivariate models . For tho2.5https://github.com/AnnaBonkhoff/Reclassifying_stroke_lesion_anatomy. Lesion maps of the final 21 archetypal clusters in MNI-space can be downloaded here: https://github.com/AnnaBonkhoff/Reclassifying_stroke_lesion_anatomy. Any new, test lesion can be assigned to its closest archetype by quantifying its comparative similarity on a suitable binary distance metric. The code for structure-aware filtering is openly available here: https://codeocean.com/capsule/1845868/tree/v1.The lesion maps employed in this study are available from the corresponding authors on request by email. Analyses  were pr33.1The succinct lesion representation shows a clear subdivision into 21 stereotyped clusters , centre.3.2Compared with the baseline, the succinct representation achieved substantially greater than baseline cross-validated predictive accuracy across both sets of lesion-deficit maps and all sub-networks . The RorThe observed performance also varied with the target functional anatomy. Across the Rorden-Archer models, vision and picture naming yielded larger benefits (10.8–10.9%) than the rest (4.0–7.4%). The highest scores were generally obtained for speech deficits and neglect with an accuracy of .92(±.01 95%CI) and .91(±.02 95%CI), respectively, for the model incorporating information from t-SNE coordinates (”2D”). Across the Yeo-Schaefer models, motor A, peripheral & central vision, and Control C network were most rewarding (10.1–18.9%), with a maximal improvement in case of peripheral vision. The best accuracies were found for the Default mode B network with .92(±.02 95%CI) and Control A network .90(±.02 95%CI) for “2D” model.Neither succinct representation, however, matched the 50-dimensional representation's test accuracy of .95(±.01 95%CI) for Rorden-Archer and .98(±.002 95%CI) for the Yeo-Schaefer models. This also showed less predictive variability across models and parcellations.Analysis of AUROC measures yielded an essentially identical picture .p << .001, Rorden-Archer; F-Statistic = 558.0, p << .001, Yeo-Schaefer) and “Deficit” . There was an interaction between the two factors: F-Statistic = 6.5, p << .001, Rorden-Archer; F-Statistic = 8.1, p << .001, Yeo-Schaefer, c.f. ANOVAs performed separately for the Rorden-Archer and Yeo Schaefer parcellations revealed significant main effects of “Representation” (Two-way ANOVA: F-Statistic = 352.2, 3.3Though our objective is not to compare different possible succinct representations but to quantify the potential predictive superiority of a well-crafted succinct representation against the simple baseline models in current use, we provide a qualitative illustration of the separation between clusters achievable with other techniques, with our categorial labels provided as a reference .4We have derived a representation of ischaemic lesions—drawn from one of the largest published collection of registered stroke images—that is almost as succinct as conventional lesion metrics while enabling substantively greater predictive power. Our purely data-driven approach integrates the influence of topological, mechanistic, and symptomatic drivers of the stereotypy of acutely presenting lesions, yielding a comprehensive, generalisable reclassification of the anatomy of ischaemic stroke. Membership of 21 archetypal clusters, and the coordinates within a two-dimensional embedded latent space, distil anatomical information in readily interpretable form. Each cluster is readily explicable within the causal triad of stroke lesion patterns—vascular topology, occlusive mechanism, and symptomatic eloquence—facilitating the intuitive assignment of a lesion to its category. Both the two-dimensional and categorial representations are succinct enough to be handled by relatively simple predictive models powered by modest quantities of data, for any predictive task, making their use in downstream modelling readily practicable. The clear disentanglement of spatially distinct categories assures reproducibility, for membership is determined by strongly differentiated anatomical characteristics plausibly stable across instrumental and wider brain structural variations.independently of any predictive task, it is not biased in favour or against any specific clinical context, assuring strong generalisability. An anatomical classification derived from a predictive model—long-term motor recovery, for example—would be inevitably biased by the critical anatomical decision boundary in the brain, limiting its wider utility. Indeed, explicit guidance by an outcome decision boundary always magnifies the risk of overfitting, a problem the field of representation learning (alone to derive the representation, without any supervision, from a large, essentially unselected dataset, ensures equal applicability to any predictive task. We make the 21 archetypal lesion categories available to facilitate use in downstream research and clinical settings.The principal value of this representation is as a simple “drop-in” replacement for the anatomical classifications of stroke in current use, across both observational and interventional studies. Since it is derived learning  has in prelative fidelity of different representations can be made without a hard functional–anatomical ground truth that real patient outcome data could never provide: this is because noise in the underlying dependence would unquantifiably modulate any observed effect. The magnitude of the predictive improvement is bound to vary outside idealised conditions, but key here is consistency across a wide array of plausible ground truth models encompassing the entirety of the brain. Real-world prediction needs to be quantified subsequently, only after the limits under ideal condition are established first.Equally, the ground truth models quantifying the relative predictive power must be synthetic here, even if guided by empirically-derived parcellations of the brain. Real patient outcomes for a dataset of this size would either be too coarse—such as mRS—or limited to a narrow range of functional domains, limiting generalisability. Moreover, no objective quantification of the in general is capable of achieving far better predictive power than simple metrics such as lesion volume allow, without introducing complexity in the predictive model itself. The rapidly evolving field of representation learning will bring new methods, and with larger collections of data, established methods such as deep generative models will become tractable. Methods with comparable expressive power but less stochasticity than t-SNE would be desirable, combined with predictive systems downstream within a semi-supervised framework. It is clear that simple, linear methods such as PCA are incapable of accessing the complex structure of lesions (Our approach employs t-SNE, a well-established non-linear dimensionality technique widely regarded as being capable of achieving maximal separation between the clusters of complex distributions . But our lesions .t-SNE whose stochastic nature suits it to the general identification of high-dimensional patterns rather than the categorisation of individual unseen cases (Though a lesion may be assigned to a cluster visually or automatically via distance metrics, by reference to the native-space anatomical appearances of the archetypal centroids, the most natural implementation of our new classification is by automated processing the image, now feasible even with clinical data of variable quality. The fundamental structure of the representation having been established, automated assignment would be performed by a discriminative algorithm, bypassing en cases . Comparaen cases . RenderiThough clearly superior to a basic description a lesion, the succinct representation cannot match the predictive performance achievable with a 50-dimensional embedding. Where the available data scale permits it without overfitting, high-dimensional modelling, at maximum relying on voxel-wise information, places a higher ceiling on maximal achievable performance, and remains preferable . EquallyOur representation is limited to acute ischaemic stroke: given sufficient data, analogous representations may be derived for chronic lesions, of vascular and other aetiologies whose manifestations are spatially structured. Though here confined to anatomical features, multimodal information can be brought into play if interaction with the anatomy falls within the realm of possibility. Indeed, the integration of other anatomical factors—such as white matter connectivity —and funcAnna K. Bonkhoff: Conceptualization, Methodology, Software, Validation, Formal analysis, Writing – Original, Writing - Review & Editing, Visualization; Tianbo Xu: Software, Validation, Resources, Writing - Review & Editing; Amy Nelson: Software, Validation, Formal analysis, Writing - Review & Editing; Robert Gray: Conceptualization, Methodology, Formal analysis, Writing - Review & Editing; Ashwani Jha: Conceptualization, Formal analysis, Writing - Review & Editing; Jorge Cardoso: Writing - Review & Editing, Funding acquisition; Sebastien Ourselin: Funding acquisition, Geraint Rees: Writing - Review & Editing, Funding acquisition Hans Rolf Jäger: Conceptualization, Methodology, Writing – Original, Writing - Review & Editing; Parashkev Nachev: Conceptualization, Methodology, Formal analysis, Resources, Writing – Original, Writing - Review & Editing, Visualization, Supervision, Funding acquisition.10.13039/100010269Wellcome Trust and the UCLH NIHR Biomedical Research Centre.This work has been funded by the None.