An emerging issue for orthopedic surgeons is how to manage patients with active or previous COVID-19 disease, avoiding any major risks for the surgeons and the O.R. personnel. This monocentric prospective observational study aims to assess the prevalence of SARS-CoV-2 viral RT-PCR RNA in cancellous bone samples in patients with active or previous COVID-19 disease. We collected data about 30 consecutive patients from our institution from January 2021 to March 2021 with active or previous COVID-19 disease. The presence of SARS-CoV-2 in the samples was determined using two different PCR-based assays. Eighteen of the thirty patients included in the study had a positive nasopharyngeal swab at the time of surgery. Twelve patients had a negative nasopharyngeal swab with a mean days since negativization of 138 ± 104 days, ranging from 23 to 331 days. Mean days of positivity to the nasal swab were 17 ± 17. Twenty-nine out of thirty (96.7%) samples were negative for the presence of SARS-CoV-2 RNA. In one sample, low SARS-CoV-2 load (Cycle threshold (Ct) 36.6.) was detected but not confirmed using an additional confirmatory assay. The conducted study demonstrates the absence of the viral genome within the analyzed cancellous bone. We think that the use of personal protection equipment (PPE) to only protect from aerosol produced during surgery, both in active and recovered patients, is not strictly necessary. We think that the use of PPE should not be employed by surgeons and the O.R. personnel to protect themselves from aerosols produced from the respiratory tract. Moreover, we think that our results could represent a valid basis for further studies related to the possibility of bone donation in patients that suffered and recovered from COVID-19. On 11 March 2020, the World Health Organization (WHO) declared the SARS-CoV-2 disease as a global pandemic. Little is known about how SARS-CoV-2 infection can negatively affect the musculoskeletal system [SARS-CoV-2 belongs to the coronavirus family and represents a new viral strain never identified in humans before. This virus is transmitted by air through the emission of droplets. Infection is favored by close contact among people, particularly in closed environments such as hospitals; therefore, nosocomial infections from SARS-CoV-2 are widely reported in the literature ,4. SARS-However, it is important to emphasize that air transport may not be the only way of transmission. In particular, contagion by direct or indirect contact with mucous membranes of the eyes, mouth, and nose has been described . SARS-CoThe COVID-19 outbreak resulted in a severe reduction in operating capacity all around the world and cessation of routine elective surgery to reduce the pressure on the intensive care unit (ICU) ,5.Due to the COVID-19 pandemic, resources have been allocated to ICUs and COVID-19 wards and many “non-urgent” orthopedic surgeries have been postponed or canceled to preserve medical resources. The “Non urgent orthopaedic surgery” was defined as planned non-trauma-related surgery ,8,9.An emerging issue for orthopedic surgeons is how to manage patients with active COVID-19 disease or patients who have recovered from it and need urgent trauma surgery for fracture management. Another compelling issue is the return towards full trauma operating capacity and elective orthopedic services, avoiding any major risks for the patients and the healthcare worker team, once the peak of COVID-19 pandemic begins to fall .This topic will be a major issue for any orthopedic surgeons and health workers who have to perform surgical procedures on patients with active COVID-19 or recovered patients.Does any long persistence of SARS-CoV-2 occur in cancellous bone? Should all the operative room (O.R.) team treating healed patients wear protection devices as is done for those infected by COVID-19? How long should we wait before treating a healed patient without preventive measures concerning to O.R. organization and personal protective equipment (PPE)?The presence or absence of the virus in cancellous bone could help us answer questions about the management of bone donation in COVID-19-recovered patients.All these questions need to be answered and this paper aims to assess the prevalence of SARS-CoV-2 RNA in cancellous bone samples in patients hospitalized with active or previous COVID-19 disease.This monocentric prospective observational study aims to assess the prevalence of SARS-CoV-2 RNA in cancellous bone samples in patients with active or previous COVID-19 disease, who have been hospitalized in our hospital Policlinico San Matteo di Pavia  and have undergone orthopedic surgery. These findings will improve our knowledge on infection from SARS-CoV-2 and its tropism for human tissues.We intend to assess the presence level of SARS-CoV-2 RNA in cancellous bone and its association with: (i) disease status ; (ii) the time since healing in healed COVID-19 patients; and (iii) the viral load and the time since recovery in recovered COVID-19 patients.This is a cross-sectional observational study with both retrospective and prospective collection of data from stored biological samples and clinical charts.We collected data about 30 consecutive patients from our institution from January 2021 to March 2021. These patients were either affected by acute COVID-19 disease or achieved recovery  and required urgent orthopedic surgery. We enrolled them in this clinical trial after informed consent was acquired.Inclusion criteria were as follows: (i) patients who underwent urgent orthopedic surgery for fractures or other musculoskeletal injury requiring surgery; (ii) patients affected by acute COVID-19 disease or patients who achieved healing ; (iii) informed consent signed.Exclusion criteria were as follows: (i) patients younger than 18 years old; (ii) inability to understand the information about the study and to provide informed consent; (iii) incomplete information/data about the previous COVID-19 disease.Patients’ demographics and surgical data were collected from the databases which included: age, sex, medical history, BMI, date of admission, date of surgery, procedure and injury type, and COVID-19-related symptoms. The American society of anesthesiologists classification (ASA) score for preoperative risk was recorded on the theatre database and used to assign physical status.COVID-19 infection was diagnosed in respiratory samples by using two different PCR-based assays in the preoperative period. Specific, real-time reverse transcriptase-polymerase chain reaction (RT-PCR) targeting RNA-dependent RNA polymerase (RdRp) and E genes were used to detect the presence of SARS-CoV-2, according to WHO guidelines and Corman et al. protocols ,11.® Xpert® SARS-CoV-2 assay  was used to prove positivity obtained previously.Spongy bones from SARS-CoV-2-positive patients were collected in a 3 mL universal transport medium  and stored at −80 °C until analyzed. Extraction of SARS-CoV-2 RNA was performed on inactivated UTM using the Quick-Viral RNA kit  per the manufacturer’s protocol. Viral RNA was eluted with 50 µL of DNase/RNase-free water. The presence of SARS-CoV-2 in the samples was determined using the same assays used for diagnosis ,11. A cop-value < 0.05 will be statistically significant.All analyses will be used using Stata 16 . All tests will be 2-sided. A The sample size calculation is based on the desired precision of the prevalence. We plan to be able to enroll about 40 patients in the next 3 months. With this sample size, we will obtain a precision of the estimate of the prevalence at most of 16%  in the less-favorable scenario from a mathematical point of view, in the absence of any prior information, of a prevalence of 50%).Continuous data will be described with the mean and standard deviation or the median and quartiles, depending on the distribution; categorical variables will be described as counts and percent.The prevalence will be computed as the ratio of the positive patients to the total enrolled patients, together with its 95% binomial exact confidence interval.The prevalence for each type of sample will be computed as described above. The comparison will be performed with Fisher’s exact test; the mean difference and 95% CI will be computed.The SARS-CoV-2 load expressed as cycle threshold will be compared between groups with the Mann–Whitney U test.The association of SARS-CoV-2 load and time since healing will be assessed with the Spearman R and its 95% CI.Our population consists of: 30 patients, 19 females and 11 males; the mean age was 77 ± 15 years old with a range from 30 to 93 years old; the mean BMI was 25 ± 5.We divided the orthopedics diagnosis into four main groups: the first one was femoral fracture, the second one was tibial fracture, the third one was humeral fracture and the last one was all the other. Half of the patients (15) were diagnosed with femoral fracture (group 1), three (3) were diagnosed with tibia fracture (group 2), two (2) were diagnosed with humeral fracture (group 3) and ten (10) with other diagnosis (group 4) .We divided patients into three main groups based on different types of surgical operation. The first group included patients undergoing open reduction and internal fixation (ORIF) or close reduction and internal fixation (CRIF). The second group included patients who underwent hip hemiarthroplasty surgery and the last group involved patients undergoing all the other invasive surgery . SixteenFourteen patients had an ASA score of 3, thirteen had an ASA score of 2, and the remaining three had an ASA score of 1 .Mean days of hospitalization was 6.7 ± 10 ranging from 0 to 39. Eighteen of the thirty patients included in the study had a positive nasopharyngeal swab at the time of surgery. Twelve patients had a negative nasopharyngeal swab at the time of surgery with a mean days since negativization of 138 ± 104 days ranging from 23 to 331 days. Mean days of positivity to the nasal swab were 17 ± 17. As we checked COVID-19-positive patients every 3 days by means of nasal swab, all the patients considered positive in the O.R. had a positive nasal swab after less than 72 h before surgery. Half of the patients (15) had radiological signs of COVID-19 at the chest X-ray, executed right after the positive nasal swab, and nine (9) of them had bilateral signs .2, chest pain, nasal congestion, headache, dizziness, diarrhea, and abdominal pain. All the patients had one or more of these symptoms during their COVID-19 infection. None of them had COVID-19-specific therapy or were vaccinated.We collected a number of COVID-19-related signs and symptoms, including fever, cough, fatigue, sore throat, dyspnea, spOTwenty-nine out of thirty (96.7%) samples were negative for the presence of SARS-CoV-2 RNA. In one sample, low SARS-CoV-2 load (Cycle threshold (Ct) 36.6) was detected but not confirmed using an additional confirmatory assay.The new coronavirus pandemic severely affected health care systems worldwide. All surgical specialties had to adapt to different innovations, and changes have been introduced with regard to surgical and outpatient activities.The necessity of placing more attention and resources on the clinical management of COVID-19 patients has caused these changes. The introduction of some new features was necessary to limit the transmission of the virus and thus the infection in health care personnel . In factIt is known that the virus is present in the blood. The current attitude is to exclude blood donors in cases of COVID-19 positivity. Despite this, transmission of infection has never been reported from donor to recipient either in transfusion of blood products or cellular therapies .According to Xia et al., the presence of the virus in tears and conjunctival secretions has only been demonstrated in SARS-CoV-2-infected patients with conjunctivitis, whereas in SARS-CoV-2 patients without conjunctivitis, the presence of the virus was not demonstrated on RT-PCR analysis. Therefore, it has been proved that tears and conjunctival secretions are not a route of virus transmission from patients SARS-CoV-2 who are not suffering from conjunctivitis .Grassi et al. searched for viral RNA within synovial fluid and bone tissue samples taken post-mortem in patients who died of SARS-CoV-2 respiratory complications. Again, the results were negative . To the It is well-known how the virus is transmitted directly. Less known are the capabilities of indirect transmission.During orthopedic surgery, many power instruments, such as bone saws, drills and reamers are used, and they are known to be producers of blood aerosols. The theory has been therefore postulated that virus transmission to health care workers may occur through these aerosols. Consequently, some authors have defined a series of preventive measures to be taken in case of COVID-19-positive patients undergoing orthopedic surgery . For exaPersonal protection equipment (PPE), such as FFP2 masks, face shields and goggles, are commonly used during surgery of COVID-19-active patients to protect the surgeon. The same equipment is used during anesthesiologic procedures and for O.R. cleaning . OrthopeThe objective of our study was to understand whether or not there was viral RNA shedding with aerosol, posing a risk to health care providers during orthopedic surgical procedures on positive or previously infected patients.After informed consent was signed, we obtained cortical spongiosa bone tissue samples from the patients during surgery for standard RT-PCR assay. Almost all samples were negative, and the only positivity was not reconfirmed with an additional assay.Due to its specificity and sensitivity, RT-PCR is a simple, convenient, and efficient technique to search for viral nucleic acid in the samples. Moreover, it is the gold standard for diagnosis. On the other hand, Lin et al. identified in their review several false positives and negatives due to contamination and damage of samples .These results are obtained either among COVID-19-positive patients during surgery or healed COVID-19 patients. We did not find any association between the disease status  and the prevalence of positive RT-PCR. We did not find any association either between the time since healing and the prevalence of SARS-CoV-2 positivity or level of SARS-CoV-2 load. In any case, we did not detect the presence of the virus in the bone samples, indicating that it is not a common way of virus transmission.Considering these findings, we think that the use of PPE to only protect from aerosols produced during surgery is not strictly necessary in both active and healed patients. This does not mean that the use of PPE should not be employed by surgeon and the O.R. personnel to protect themselves from aerosols produced from the respiratory tract.Another challenge created by the COVID-19 pandemic is the management of the tissue bank, primarily due to the possibility of human tissue contamination or the risk of disease transmission following transplantation. Therefore, tissue banks all over the world established strict preventive measures, or in some cases stopped collecting samples. On the other hand, at the moment, no documented reports have proved any COVID-19 infection following tissue transplantation ,21. We tThe main limitation of the study is the small size of the sample due to the availability of resources. In order to improve the study reliability, it should be implemented with further cases in future studies.Our study demonstrates the absence of the viral genome within the analyzed cancellous bone. This leads us to assume that SARS-CoV-2 has no direct bone affinity. We think that the aerosol generated during orthopedic surgery, in patients with active COVID-19 or healed, does not represent a risk of infection for the surgeons and the O.R. personnel. Therefore, PPE should not be necessary for this part of the surgery only.Despite this, normal activities in the operating room with COVID-19-active patients, such as intubation, moving the patient to the operating table, etc., can promote the dispersion of viral particles into the environment. Consequently, this may cause the infection of health care personnel. It is therefore imperative to take preventive measures in the operating room when performing surgery on a COVID-19-active patient, especially through the use of PPE, in order to prevent virus transmission.The small number of patients is the main limitation of the study, and for this reason further studies are needed to better understand the exact natural history of the disease.We think that our results could represent an important basis for further studies related to this topic.


Segmentation of abdominal Computed Tomography (CT) scan is essential for analyzing, diagnosing, and treating visceral organ diseases . This paper proposes a novel neural network (Res-PAC-UNet) that employs a fixed-width residual UNet backbone and Pyramid Atrous Convolutions, providing a low disk utilization method for precise liver CT segmentation. The proposed network is trained on medical segmentation decathlon dataset using a modified surface loss function. Additionally, we evaluate its quantitative and qualitative performance; the Res16-PAC-UNet achieves a Dice coefficient of 0.950 ± 0.019 with less than half a million parameters. Alternatively, the Res32-PAC-UNet obtains a Dice coefficient of 0.958 ± 0.015 with an acceptable parameter count of approximately 1.2 million. Interventional radiologists rely heavily on CT scans for the diagnosis and treatment of cancer and metastasis in the visceral organs ). Moreover, CT imaging is an alternative to MRI for imaging patients with metallic implants and pacemakers. Specifically, CT scans are necessary for localizing tumors, examining tumor shapes, and estimating tumor volume in different liver segments, thus playing a vital role in the diagnosis and treatment planning of HCC.Computed Tomography (CT) scan is a non-invasive medical imaging technique for obtaining 3D high-resolution images of different organs2. Automatic segmentation algorithms with low disk and memory utilization can serve as an effective alternative to the manual delineation by generating the segmentation masks of the liver and its tumors based on the input CT scans. These automatic segmentation algorithms can save both time and effort of interventional radiologists and surgeons, allowing them to focus more on treatment planning and surgeries.Analysis of abdominal scans is for detecting liver cancer and other visceral diseases. Conventionally, the radiologists manually delineate the region of interest (ROI)  to measure the cancer spread and plan appropriate treatment. Outlining the liver and its tumors allows the surgeons to plan treatment that minimizes the damage to healthy liver tissues. The delineated CT scan can further be registered with other imaging modalities , producing enhanced visualization for image-guided surgeries. However, the manual delineation of medical images is tedious, and operator-dependentThe automatic segmentation algorithms face several challenges due to the nature of CT scans . In addition to these challenges, the segmentation algorithms may need to work in a disk and memory-constrained environment in hospitals to maximize their applicability and usability. To elaborate further, several scenarios in a clinical space require lighter segmentation models: (1) Efficient intra-procedural image fusion to improve visualization  requires automated liver tumor segmentation techniques for planning appropriate treatment procedures. Lightweight CT segmentation tools enhance the chances of being deployed on clinical machines (in operation theaters) to help reduce total procedure time, where the patient may be under sedation/anesthesia or being exposed to chemoradiation. (2) Turnaround time (TAT) is an essential quality indicator of radiology services, especially in the emergency setting. Segmentation models that maximize segmentation accuracy could be crucial in improving TAT and clinical workflows if they have lower computational requirements (like disk utilization).5 and deep learning-based8 segmentation algorithms have been proposed to overcome the challenges in CT scans and maximize segmentation accuracy. However, the methods have not emphasized maximizing performance in disk and memory-constrained environments. The conventional segmentation techniques are based on region growing9, thresholding11, watershed12, active contours14, clustering15, graph cut17, etc. These techniques may have application-specific advantages, but their dependence on primitive image features  significantly impacts their robustness and generalization capability. Recently, deep learning-based techniques have gained significant attention for liver CT segmentation because of their improved accuracy, automation, and robustness8.Over the years, many conventional7 is one of the popular architectures for biomedical image segmentation. One of the main advantages of the UNet over the preceding fully convolutional networks (FCNs) is that it has a dedicated decoder for stage-wise construction of the segmentation masks. Additionally, the UNet has skip connections to improve information/gradient flow and alleviate the loss of spatial information caused by repeated pooling operations. Initially, UNet was proposed to segment 2D biomedical images, Çiçek et al.18 extend the UNet architecture for volumetric segmentation of medical images by replacing 2D kernels with 3D kernels in convolution layers. Milletari et al.19 present the VNet architecture that uses convolutions with strides  for down sampling image resolution and de-convolution  to upscale encoded features for generating the segmentation masks. Like UNet, the VNet employs skip connections to improve gradient flow through the network. However, the UNet and VNet architectures may not be suitable for segmenting noisy CT scans with poor contrast because they lack network logic that can capture ambiguous anatomical boundaries  and small ROIs .The neural network-based segmentation overcomes the limitations of the conventional segmentation methods by automatically extracting relevant features using convolutional kernels in a data-driven manner. UNet20 present a deep convolutional neural network that uses short residual skip connections within the backbone and long skip connections between the encoder and decoder to improve feature propagation. The model achieves acceptable segmentation accuracy but has a large parameter count and longer inference times. Sun et al.21 introduce a multi-channel fully convolutional network (MC-FCN) for segmenting liver tumors from multi-phase contrast-enhanced CT scans by utilizing phase information to generate high-level fused features. The critical limitation of MC-FCN is the lack of multi-phase CT data, limiting the method’s applicability in clinical settings. Zhang et al.22 propose a prior propagation module (PPM) to learn the spatial priors of the pancreas on different axes. Then, a scale-transferable feature fusion module (STFFM) is employed to generate rich feature fusion. Resulting DCNN outperforms other architectures for pancreatic segmentation but contains nearly 25 million parameters . Zhang et al.24 have also introduced a network that captures and combines information from different modality MRI scans to segment three different regions of brain tumors effectively. The work is limited by minimal discussion on parameter count, disk utilization, inference time, and evaluation with brain CT data.In recent years, custom encoder-decoder architectures with custom modules have been proposed to overcome the shortcomings of vanilla 3D UNet. Han et al.26 have also been proposed for segmenting liver in CT scans. Li et al.8 introduce H-DenseUNet, which uses 2D Dense-UNet for extracting intra-slice information and 3D Dense-UNet for aggregating volumetric details. Seo et al.27 present a modified UNet (m-UNet) architecture with a residual de-convolution module over the skip connections. The resultant network effectively combines the 3D voxel information of the encoder and passes it to the decoder to achieve high liver segmentation accuracy. One significant limitation of H-DenseUNet and m-UNet is the presence of numerous parameters, which results in prolonged training, higher memory footprint, and model size, thus impacting their usability on clinical computers. Jha et al.28 propose the Res-UNet++ architecture using squeeze and excitation principle in the encoder and attention mask in the decoder to propagate relevant features for the liver segmentation task. Furthermore, the network employs an atrous spatial pyramid pooling module at the bottleneck to generate multi-scale high-level features. Jha et al.28 have highlighted in their discussion that the increased performance of the Res-UNet++ is at the cost of increased network parameters. Ibtehaz et al.29 propose the Multi-Res-UNet that combines features extracted with kernels of different sizes using residual connections in the network backbone. Further, the skip-connections contain a sequence of convolutional layers to decrease the semantic gap between the encoder and decoder. Lou et al.30 suggest another network, DC-UNet, by modifying the multi-res block, introduced by Ibtehaz et al.29 with a dual-channel block to enhance the capability of residual connections for extracting multi-scale features. One common limitation of Res-UNet++, Multi-Res-UNet, and DC-UNet is the use of 2D convolutions in their implementation, which does not utilize the axial information of CT scans. Modifying their implementation with 3D convolutions exponentially increases the network parameters, preventing their training due to GPU memory constraints. Throughout our review, we have observed that UNet and its variants double the feature map width at every encoder stage, resulting in large parameter counts, making them infeasible for deployment on machines with disk and memory constraints.Variants of UNet27.We have also identified two fundamental limitations of the UNet. Firstly, UNet employs skip connections between the encoder and the decoder resulting in the duplication of low-resolution feature maps. The low-level extracted features in the early layers of the encoder propagate through the network backbone. Simultaneously, the skip-connections transfer the same feature from the encoder to the decoder, resulting in feature redundancy and causing smoothing of anatomical boundaries. Secondly, the high-level features learned in the deeper layers of the encoder lack the organ boundary information due to repeated pooling operations, thus impacting the segmentation accuracy31, namely, the Res-PAC-UNet, that overcomes the limitation of UNet and its variants for liver CT segmentation. Specifically, our method aims to achieve high liver segmentation accuracy while utilizing less network parameter and disk space. Fundamentally, we make the following contributions: We propose tuned backbones with residual connections and fixed-width that minimize the parameter count of the network, while improving gradient flow and segmentation performance (Methodology: Network Architecture).We introduce a Pyramid Atrous Convolution (PAC) module over the skip connections of the encoder to extract multiscale volumetric features, assisting the network in constructing liver masks from CT scans with poor anatomical boundaries and contrast (Methodology: Pyramid Atrous Convolution Module).32 by incorporating the combo loss, allowing the loss function to quantify the discrepancies between the network prediction and ground truth (Methodology: Loss Functions).We modify the surface loss function proposed by Kervadec et al.30 (Results and Discussion).We empirically evaluate the impact of the loss functions and PAC module on the segmentation accuracy of the Res-PAC-UNet and other architectures in the UNet family. Furthermore, we compare the segmentation performance of the Res-PAC-UNet with the state-of-the-art for liver CT segmentation modelsTo the best of our knowledge, this work presents significant advantages over the existing work in the literature by emphasizing lower parameter count, smaller model size, and usability of the model without compromising the segmentation accuracy.In this paper, we propose a novel neural network architecture inspired by Thin-UNetThe remainder of the paper is structured as follows: “7. We have also trimmed the K to half of the initial width of the UNet  to understand its impact on segmentation accuracy. Unfortunately, We could not train the Res-PAC-UNet with higher values of K due to limited GPU memory. Secondly, we overcome the problem of redundant features and loss of edge information in deeper feature maps by proposing an intuitive solution of generating features of different scales before transferring them to the decoder. To compute multi-scale volumetric features at different encoder levels, we place PAC modules  is the activation function applied to the result of the convolution, jth kernel, respectively. Based on this definition of the convolution operation, the residual block can be expressed as:Additionally, The residual blocks replace the convolutional blocks and perform downscaling of the input feature maps by employing strided convolutions. Figure 28, Multi-Res-UNet29, DC-UNet30, and TMD-UNet33 architectures proposed for liver CT segmentation in our study to establish a thorough comparison with the literature.We evaluate our proposed models’ segmentation performance and disk utilization by conducting an extensive experimental study with the original UNet as the baseline model. Then, we tune the UNet backbone by shrinking the feature width of the first layer, thereby every successive layer of its encoder, to decrease the overall parameter count. We name the resulting model Tuned-UNet. Subsequently, we add the PAC module to the proposed tuned Res-UNet (Res-PAC-UNet) to measure its performance impact. Finally, we modify the Thin UNet architecture by adding PAC modules to compare its performance with the Res-PAC-UNet architecture. For Res-PAC-UNet and Thin-PAC-UNet, we are limited to constant feature widths of 16 and 32 in the backbones due to memory constraints on the GPU. Furthermore, we include Res-UNet++34 propose a Pyramid Scene Parsing (PSP) module to improve semantic segmentation performance by enhancing contextual relationships between the image regions and serving as a global contextual prior. The PSP module extracts multi-scale contextual features by performing max pooling operations at different scales, followed by 135 overcome the limitation of the PSP module in the DeepLabV3 architecture by replacing the max pooling operation with atrous convolution. The resulting Atrous Spatial Pyramid Pooling (ASPP) utilizes convolution with different dilation rates to capture varying fields of view in the feature maps, thereby generating multi-scale volumetric features and controlling the receptive field of the network. It can be observed that the 335 recover the missing edge pixel information by using global average pooling (GAP) followed by upsampling.Zhao et al.dilation rate = 24) because the overall size of the kernel becomes similar to the dimension of feature maps in the deeper layers of the encoder, helping to decrease the parameter count of the PAC module. These convolutions may not be helpful because they may capture features from different corners of the CT scan rather than emphasizing the liver region. The lower dilation 3D convolutions allow PAC to extract organ-specific multi-scale volumetric features. These features allow the network to utilize essential intra- and inter-slice information to differentiate the liver from the background. The PAC module is placed at the deeper skip connections of the tuned Res-UNet backbone to pass multi-scale features from multiple levels of the encoder, thus preventing duplication of low-level features and smoothing of anatomical boundaries. Finally, the decoder utilizes multi-scale information when upsampling the feature maps at different stages to construct liver segmentation masks effectively. Figure r is the dilation rate, jth kernel, respectively. The rest of the parameters have the same meaning as in the regular convolution defined previously. Based on this definition of the dilated convolution operation, the PAC module can be given by:I and O are the input and output of the PAC module, respectively. GAP represents the global average pooling operation. Upsample3D rescales the feature map to the same dimension as the This paper proposes the PAC module based on ASPP to segment abdominal 3D CT scans. Fundamentally, PAC is a 3D extension of ASPP with lower dilation rate convolutions . We drop high dilation rate convolutions  provides up to 8% performance improvement in Dice coefficient. We modify the surface loss function by replacing the generalized Dice loss with combo loss  that emphasizes the ROIs’ class and area distribution, aiming to improve the class accuracy metrics. Furthermore, we propose an alternative weight shifting strategy, shifting the weight from 0.99 to 0.25 on the combo loss and 0.01 to 0.75 on the boundary loss. Initial increased weight on combo loss ensures that the network learns the area and statistical distribution of the liver in the earlier epochs. As the weight shifts towards the boundary loss in later epochs, the network is trained to learn the anatomical boundaries of the liver. To add stability to network training, the suggested weight shifting strategy ensures that the combo loss has a fair portion of the net weight at the end of the training.Kervadec et al.36 to train our models. The liver segmentation challenge contains 201 contrast-enhanced CT scans divided into the training (131 scans) and test (70 CT scans) sets. The spatial dimension of the CT scans is 51237. The ground truths of the CT scans in the test set are undisclosed because of ongoing community challenges. For this reason, we split the original training set of the dataset and performed training with 101 scans and testing with 30 scans. Despite the quality measures taken during the acquisition, the CT scans have poor contrast, overlapping anatomical boundaries, noise, and significant variations in axial resolution, making the image pre-processing, neural network training, and evaluation of liver CT scans challenging.We employ the liver CT scans provided in the medical segmentation decathlonvolumentations38 package to reduce overfitting. The augmentations are randomly applied to the scans and include flips  and transpose operations.Figure To minimize the I/O and computational costs, we pre-process the CT scans and store them in RAM before the training. Additionally, we define the neural networks in Keras and utilize the Tensorflow dataset generator with prefetching to ensure that the neural networks are efficiently fed with augmented scans and the ground truth. The networks are trained for 150 epochs to ensure model convergence Fig. . Adam opThe models are trained on an HP Z8 workstation with an Intel® Xeon(R) Silver 4216 CPU with a 2.10 GHz base clock (64 cores) and 128 GB of system memory. The workstation also contains an Nvidia Quadro RTX 5000 GPU with 16 GB of VRAM. With the above implementation, the training procedure for the Res32-PAC-UNet model has taken approximately 12 hrs.We evaluate the segmentation performance of the networks, mainly by computing area/volume overlap, and class-based accuracy. The metrics can be defined as follows:Dice Coefficient (DC) and Symmetric Volume Difference (SVD): DC is a region-based metric described as Intersection over Union (IoU) and Volume Overlap Error (VOE): IoU measures the extent of area overlap, which can be described as Specificity: Specificity measure the ratio of correctly marked negative pixels to the total number of negative pixels in the predicted mask. Specificity is expressed as Sensitivity: Sensitivity measures the ratio of correctly marked positive pixels to the total number of positively marked pixels in the predicted segmentation map. Sensitivity is calculated as Table The modified surface loss allows the Res32-PAC-UNet to achieve the highest segmentation accuracy among the tested loss functions with accelerated convergence. These results can be explained by the dynamic nature of the loss, which shifts the weights from the combo loss to boundary loss during training. The initial emphasis on the combo loss allows the model to learn the volumetric ROI effectively. In contrast, a definite focus on the boundary loss in the later epochs improves the edge precision of the predicted segmentation masks. In our empirical study, we train the remaining neural networks with the modified surface loss function because of its emphasis on crucial aspects of segmentation masks and superior segmentation accuracy.29 architecture. We modify the Thin-UNet architecture by adding the PAC modules and 3D image compatibility to measure the performance enhancement in the fixed-width backbones. The Thin16-PAC-UNet and Thin32-PAC-UNet outperform the UNet, highlighting the performance gains due to PAC modules in fixed-width lightweight backbones. Next, we add the PAC modules to the tuned Res-UNet backbones. The results show that both Res16-PAC-UNet and Res32-PAC-UNet models significantly boost segmentation performance, with DC increasing from 93.1 to 95% and 95.4 to 95.8%, respectively. Based on this observation, we can deduce that the accuracy gain due to the PAC modules is higher in lighter backbones , thus establishing its importance for lightweight UNet-based backbones. We also note that the Res32-PAC-UNet outperforms the remaining models on all metrics except the specificity.We conduct a comprehensive empirical study to quantify the impact of using the tuned residual UNet backbone and the PAC module. The performance of the UNet model is established as the baseline for segmentation accuracy and parameter count. Table Figure The best-in-class segmentation performance and faster convergence of the Res32-PAC-UNet could be associated with the choice of the tuned residual backbone and the usage of PAC modules. The network’s backbone has a fixed width of 32 to reduce the exponential growth of the parameter, minimizing disk utilization. Additionally, it employs residual blocks to improve information and gradient flow, thus allowing the model to learn quickly. The usage of PAC modules over the skip-connections prevents the duplication of low-level features from the encoder to the decoder, replacing them with informative multi-scale volumetric features. Altogether, the Res32-PAC-UNet model overcomes the pitfalls of the conventional UNet and its variants for liver CT segmentation and delivers a better segmentation performance with lower disk utilization.Res-PAC-UNet architecture provides the desired tradeoff between segmentation accuracy and disk utilization by varying the feature width in the backbone. Table 28 architecture has performance closer to the Res32-PAC-UNet, but contains nearly 10The Res16-UNet backbone has the lowest parameter count and disk utilization (2.18 MB) while outperforming the baseline UNet model. On the other hand, Res16-PAC-UNet outperforms Thin16-PAC-UNet and matches the performance of Thin32-PAC-UNet in terms of segmentation metrics while having less than half the parameters and models storage requirements. The higher performance of the Res16-PAC-UNet is because of better feature/gradient propagation in the residual backbone relative to the Thin-PAC-UNet architecture. The Res32-PAC-UNet model outperforms all the models in the empirical study while limiting the parameters to 1.2 million and the model size to 15.1 MB. The recently proposed Res-UNet++Based on the analysis of segmentation accuracy, parameters count, and model size, we suggest the Res16-PAC-UNet model for machines with disk constraints because it is closer in accuracy to the Tuned-UNet and has a smaller model size  across 3D imaging modalities . We would also like to construct Res-PAC-UNet like architectures using state-of-the-art computer vision findings that can outperform well-known segmentation models while achieving lower disk utilization and inference times. We plan to achieve this by enhancing the segmentation performance using knowledge distillation by pruning the networks using the TensorRT framework or quantization aware training. Additionally, we think that it may also be beneficial to design networks that achieve acceptable segmentation performance on the CPU.In this paper, we propose a novel Res-PAC-UNet architecture that provides a good trade-off between segmentation accuracy and model size. The proposed model employs a tuned fixed-width residual backbone with PAC modules to provide higher segmentation performance with fewer weights and lower disk utilization. The residual backbone restricts the exponential growth rate of the parameters while improving the information and gradient flow, thus assisting the PAC modules present over the skip-connection to extract relevant multi-scale volumetric features. The proposed networks are trained with a modified surface loss function to maximize the segmentation performance. Subsequently, we conduct an empirical study to compare the quantitative and qualitative segmentation performance of the models. We have found that the Res16-PAC-UNet contains fewer weights for liver CT segmentation, while the Res32-PAC-UNet maximizes the segmentation performance. Thus the proposed network provides flexibility to the radiologists to choose models as per their requirements.


The COVID-19 pandemic presented new challenges for the existing respiratory surveillance systems, and adaptations were implemented. Systematic assessment of the syndromic and sentinel surveillance platforms during the pandemic is essential for understanding the value of each platform in the context of an emerging pathogen with rapid global spread.We aimed to evaluate systematically the performance of various respiratory syndromic surveillance platforms and the sentinel surveillance system in Israel from 1 January to 31 December 2020.We compared the 2020 syndromic surveillance trends to those of the previous 3 years, using Poisson regression adjusted for overdispersion. To assess the performance of the sentinel clinic system as compared with the national SARS-CoV-2 repository, a cubic spline with 7 knots and 95% confidence intervals were applied to the sentinel network's weekly percentage of positive SARS-CoV-2 cases.Syndromic surveillance trends changed substantially during 2020, with a statistically significant reduction in the rates of visits to physicians and emergency departments to below previous years' levels. Morbidity patterns of the syndromic surveillance platforms were inconsistent with the progress of the pandemic, while the sentinel surveillance platform was found to reflect the national circulation of SARS-CoV-2 in the population.Our findings reveal the robustness of the sentinel clinics platform for the surveillance of the main respiratory viruses during the pandemic and possibly beyond. The robustness of the sentinel clinics platform during 2020 supports its use in locations with insufficient resources for widespread testing of respiratory viruses. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which emerged in Wuhan, China, at the end of 2019 . In paraA national influenza surveillance system was established in Israel in 1997. It includes several surveillance platforms based on data from outpatient clinics, emergency departments and a sentinel clinic network consisting of primary care clinics. The sentinel clinics are situated in all seven districts of Israel, and are run by internists, family physicians and paediatricians. During the 2019/20 influenza season, 32 sentinel clinics were part of this network.The first case of COVID-19 was identified in Israel on 20 February 2020 (week 8). While during the following 3 weeks, the sole modality for following the outbreak consisted of epidemiological investigations and contact tracing, the rapidly growing number of new patients that followed the carnival holiday of Purim on 10–11 March 2020 (week 12) highlighted the need for population-based information. Therefore, the long-standing influenza surveillance system was adapted in week 13, 2020 into a COVID-19 surveillance system  and fromThe objective of this study was to evaluate the performance and outcome of our surveillance system under the new circumstances of the year 2020.We evaluated the surveillance system from week 1 (ending 4 January) to week 53 (ending 31 December) in 2020.Several platforms were used to monitor morbidity during 2020. Those consisted of both community and emergency department platforms.To monitor morbidity in the community, we followed patient's visits to primary care physicians of the second largest healthcare maintenance organisation (HMO) in Israel, which provides healthcare services to 25% of the Israeli population. Specifically, we followed weekly consultations for upper respiratory infection (URI), influenza-like illness (ILI) and pneumonia. The diagnoses were recorded by physicians at the conclusion of each visit and were not based on specific case definitions. Return visits (visits with the same diagnosis) within 28 days were excluded. Visits were expressed as rates per 10,000 HMO members, and per 10,000 members of specific age groups. We evaluated the age groups < 2, 2–5, 6–11, 12–18, 19–64 and ≥ 65 years. During 2020, visits to a physician for all causes were added to the syndromic surveillance. Both face-to-face and virtual visits in 2020 were included in the surveillance and the analysis.We evaluated emergency department (ED) visits to eight medical centres for pneumonia. These eight medical centres belong to a single HMO, constitute 30% of the general medical centres in Israel and are located in the north, centre and south of the country. During 2020, ED visits for all causes were added to the syndromic surveillance. The ED visits for all causes were expressed as crude numbers. The ED visits for pneumonia were expressed as crude numbers and as percentage of the ED visits for all causes. The diagnoses were recorded by physicians at the conclusion of each visit.Supplementary Table S1 outlines the case definitions used by sentinel clinics, as well as the viruses tested for throughout 2020. Convenience sampling has been implemented in all sentinel clinics during influenza seasons and throughout the year 2020. The samples were transported to the MOH Central Virology Laboratory in cooling conditions. Starting in week 13, the samples were transported to the laboratory twice a week (as compared with once a week during influenza surveillance seasons). In the early stages of the pandemic, sentinel clinic patients who were quarantined were sampled in their homes by emergency services medical staff [Sentinel surveillance was performed in sentinel clinics spread throughout Israel. During epidemiological weeks 1–11, the clinics followed the long-standing ILI case definition, which has been routinely used for sentinel surveillance in Israel, and for which samples are routinely tested for influenza virus and for respiratory syncytial virus (RSV). This case definition includes the following symptoms: a temperature of ≥ 37.8 °C with at least one of the following symptoms: rhinorrhoea, cough, sore throat and muscle ache. Medical teams were provided the option to include other symptoms and/or signs that appeared important. Starting in week 13 of 2020, the clinics were requested to obtain nasopharyngeal samples from patients who fulfilled the case definition of a suspected COVID-19 case (see below), but did not have a history of exposure to a laboratory-confirmed COVID-19 patient or history of returning from foreign travel in the 14 days before illness onset. Symptomatic patients with a history of contact or foreign travel were eligible for SARS-CoV-2 testing by non-sentinel procedure based on guidelines from the Israel Ministry of Health (MOH). The case definition was based on an MOH directive issued before the detection of the first COVID-19 case in Israel [al staff . Those sStarting in week 13 of 2020, the Israel Center for Disease Control (ICDC) provided the sentinel clinics with personal protective equipment (PPE) for use during sampling. The PPE included surgical masks, visors, gowns and gloves .A national SARS-CoV-2 PCR test repository was established at the beginning of the COVID-19 pandemic in Israel to capture all SARS-CoV-2 PCR test results from all laboratories approved by the MOH to perform the test. The repository included result of each SARS-CoV-2 test, date of testing and the date when the result was available. Non-sentinel PCR testing was based on symptoms (e.g fever > 38 °C and/or acute respiratory symptoms) and/or exposure to SARS-CoV-2-positive contacts and/or foreign travel, as well as belonging to high-risk populations. Thus, PCR testing outside the sentinel clinics was not limited to individuals who presented with symptoms, and the repository included tests results from both symptomatic and non-symptomatic individuals. The number and rate of weekly SARS-CoV-2 cases in Israel were calculated based on the repository data. To calculate the number of cases, only the first positive PCR test of each individual was considered. Additional positive PCR tests for the same individual were excluded from analysis.Viral nucleic acid was extracted from sentinel samples using the MagNA PURE 96 system . Real-time RT-PCR reactions were conducted using primers targeting the SARS-CoV-2 envelope (E) and nucleoprotein (N) genes based on a previously described protocol . All RT-Rates of weekly patient visits per 10,000 HMO members were calculated for all ages and for specific age groups. We calculated percentages of weekly visits to internal medicine and paediatric ED and of weekly positive SARS-CoV-2 samples. Rates of national weekly SARS-CoV-2 cases were calculated based on the national SARS-CoV-2 repository data.Patients visit rates to outpatient clinics for URI, ILI, pneumonia and all diagnoses in 2020 were compared with each of the years 2017 to 2019 by using Poisson regression adjusted for overdispersion.To compare the sentinel network weekly percentage of SARS-CoV-2-positive cases to the weekly percentage of the national SARS-CoV-2-positive cases, a cubic spline with seven knots with 95% confidence intervals (CI) was applied to the sentinel network weekly percentage of positive SARS-CoV-2 cases.Statistical analysis was performed with statistical software programmes R version 3.5.2  and SAS Enterprise Guide 7.1 .Supplementary Figure S1. Specifically, the number of weekly new and cumulative SARS-CoV-2 cases, based on national SARS-CoV-2 PCR testing are shown as well as with key events in the timeline. The weekly number of SARS-CoV-2 patients was based on the national SARS-CoV-2 repository data.The evolution of the SARS-CoV-2 pandemic in Israel during 2020 is demonstrated in Supplementary Figure S2). The URI increases started 1–2 weeks after school openings  were positive for SARS-CoV-2.Supplementary Figures S3 and S4. During the first 11 weeks of 2020, influenza and RSV detections in sentinel clinics were consistent with the seasonal pattern. Influenza and RSV sentinel surveillance for the 2020/21 season, which started in week 40 of 2020, did not detect influenza or RSV in samples obtained at sentinel clinics through week 53 of 2020. The number of weekly influenza- and RSV-positive samples from sentinel clinics during the 2020/21, 2019/20, 2018/19 and 2017/18 seasons are provided in The COVID-19 pandemic presented several challenges for the Israeli surveillance system. The decline in patient visits for respiratory diagnoses to physician's offices and EDs modified our ability to understand the seasonal trends of respiratory illness during 2020. This decline was most probably due to public concern about visiting medical facilities and contracting COVID-19 and to the implementation of non-pharmaceutical intervention and physical distancing measures.A decline in physician's visits for respiratory illness was also observed during 2020 in the United Kingdom (UK) , except It is important to note that the decline in patient visits for respiratory illness started before any substantial increase in COVID-19 cases in Israel. This early decline was probably due to public health warnings regarding the new coronavirus, and the implementation of public health measures before the first COVID-19 cases in Israel, both affecting the population's behaviour. As a result, patient visits to primary clinics and EDs for respiratory illness could not contribute to early warning of COVID-19 cases in Israel.It is also interesting to note that while ED visits for all diagnoses declined to below seasonal levels, community physician visits for all diagnoses did not decline. The latter is probably due to the implementation of virtual physician visits by Israeli HMOs in the early stages of the pandemic.Despite the overall lower rate of URI physicians' visits, school openings were associated with increases in physicians' visits for URI. However, since these did not consistently parallel the rises in national SARS-CoV2 case rates, other pathogens may have been involved. In this regard, previous studies demonstrated that school openings were associated with increase in respiratory infection and school closures were associated with their decline ,16.The availability of the national SARS-CoV-2 testing system provided a unique  opportunity to evaluate the robustness of the sentinel surveillance system during the first year of the pandemic which included three waves of transmission in Israel. A previous publication from Israel  assessedThe rates of SARS-CoV-2-positive children aged 6–11 and 12–18 years registered in the Israel national repository were equivalent to those in older age groups. A recent systematic review and meta-analysis showed that children transmit the virus to other children at lower rates than to adults . AnotherSupplement pages 6–9 and Supplementary Figure S5 include the methodology, the results and a phylogenetic tree) provided additional support for the robustness of our SARS-CoV-2 sentinel surveillance. The largest proportion of samples from sentinel clinics belonged to clade 20C, which is predominantly a North American clade, followed by clades 20B and 20A which originated in Europe [Whole genome next generation sequencing performed on SARS-CoV-2-positive sentinel samples . MOH restrictions on travel from South-East Asia to Israel, implemented in the early stages of the pandemic, may have contributed to their absence in Israel.The lack of viruses belonging to the 19A and 19B clades, which were predominant in Asia during the initial period of the SARS-CoV-2 outbreak, is consistent with their global decrease, as clade 20 became the dominant strain worldwide, around March 2020 . Most sentinel samples were collected before the introduction and spread of VOCs in Israel. The first emerging VOCs, B.1.1.7 and B.1. 351 were first detected in September and October of 2020, respectively . HoweverThe lack of influenza or RSV detections between weeks 40 and 53 in 2020 are consistent with findings in the northern hemisphere during the same weeks ,26, and Our work demonstrates modified patterns of the syndromic surveillance platforms during 2020, presenting a challenge for surveillance. On the other hand, the sentinel surveillance component provided information that was consistent with SARS-CoV-2 morbidity and genomic sequencing patterns in Israel. Our findings highlight the importance of surveillance systems for respiratory pathogens in general and SARS-CoV-2 in particular. They further support the need to create and maintain robust surveillance systems, which can be expanded in the context of public health emergencies in order to monitor the spread of newly emerging pathogens. Robust sentinel surveillance is of particular importance in places and circumstances lacking sufficient capacity for a widespread testing capacity for respiratory pathogens.


To compare self-reported and police-recorded serious violence using data from a longitudinal UK birth cohort linked to local (Avon and Somerset Constabulary) police recordsTo assess the risk of police-recorded serious violence according to study participation status across the lifecourseWe linked data from the Avon Longitudinal Study of Parents and Children (ALSPAC) to local police records on charges, cautions and other out of court disposals. We compared the risk of self-reported serious violence at 8 time points from 15 to 25 years to police-recorded serious violence at these ages. We then compared the risk of police-recorded serious violence among those actively participating in ALSPAC to those not participating at various time points from pregnancy onwards. We used logistic regression to examine whether differences in risk could be explained by socio-demographic and family characteristics associated with ALSPAC participation.The sample included 12,662 participants who had received fair processing materials and had not opted out of linkage to police records. They linked to a total of 6,283 offences, of which 933 were classified as serious violence . Self-reported serious violence in the past year was particularly high at 15 years (23.5%); at other ages it ranged from 3.7% (22 years) to 8.7% (20 years). Police-recorded serious violence was lower at all ages, peaking at 1.0% at 17 and 18 years. The risk of police-recorded serious violence was higher among those not participating in ALSPAC than among active participants, particularly during adolescence and early adulthood. This difference was only partially explained by socio-demographic and other factors.A key advantage of linkage to police records is it enables outcomes to be measured irrespective of study participation status as relying only on active participants leads to bias. Combining self-reported and police-recorded outcomes allows us to derive measures of offending that take account of the biases inherent in each.


We also used immunohistochemistry assay to assess expression levels of acyl-CoA synthetase long-chain family member 4 (ACSL4), an essential executioner of ferroptosis in the same specimens. Our results showed that ACSL4 expression was significantly increased in the group with positive positive-sense strand staining compared to their negative counterparts (p = 0.00022). Furthermore, we found that there was a positive trend for increased PSS staining along with increased ACSL4 expression. Our study supports that ferroptosis is activated in the response to SARS-CoV-2 infection in the human placenta, highlighting a molecular mechanism potentially linking this coronavirus infection and pathogenesis of adverse pregnancy outcomes.Ferroptosis, a regulated non-apoptotic form of cell death, has been implicated in the response to varied types of infectious agents including virus. In this study, we sought to determine whether SARS-CoV-2 infection can induce activation of ferroptosis in the human placenta. We collected placentas from 23 pregnant females with laboratory-confirmed SARS-CoV-2 following delivery and then used RNA  Pregnancy represents a distinctive immunological condition and the remarkable changes in levels of both hormones and immune cell-released cytokines may enhance pregnant females’ vulnerability to viral infection including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) . Indeed,The majority of adverse obstetrical consequences is embedded with a placental origin, which is associated with placental inflammation because of infectious or non-infectious causes . The humRecent advances in understanding cell death under both physiological and non-physiological conditions have witnessed a significant shift with recognition of the role of ferroptosis in the regulation of cell fate in response to oxidative stress . Ferroptin situ hybridization (RNA-ISH) to detect viral positive-sense strand (PSS) as the top approach defining the placental presence by SARS-CoV-2 virions  slides with the use of the RNAScope 2.5 HD Detection (RED) Kit  according to the protocol provided by the manufacturer as well as described in our recent publication . BrieflyThe RNA-ISH was quantified with the use of QuPath, open-source software for digital pathology image analysis . The perIHC staining was performed as described in our recent studies . BrieflyACSL4 staining in IHC was quantified with use of ImageJ, an image processing program developed at National Institutes of Health . The meaU test. We used the linear regression to analyze correlation between staining degree of PSS and ACSL4.Quantitative comparisons of ACSL4 abundance between two groups were examined with the Mann-Whitney ACSL4 plays a critical role in induction of ferroptotic cell death in a variety of cell types including neurons, fibroblast, and vascular and immune cells . By shapU test determines that there was a significant difference in ACSL4 expression existing between these two groups with a p-value of 0.00022 and z-score of 3.7 , #30609 (PSS score = 2), and #30600 (PSS score = 3), suggesting that this viral infection has crossed the placental barrier. Noticeably, in #30738 (PSS score = 4), fetal blood vessels demonstrated an exceedingly strong PSS staining, and our recent study has confirmed that this is the case of transplacental vertical transmission  of increased scoring of PSS staining along with increased ACSL4 expression levels .The findings of this study are twofold. On the one hand, we used RNAScope-based RNA-ISH assay, a newly developed ISH platform, which has been extensively used for the detection of viral infection in vertebrate tissues , to examOur study has shown that SARS-CoV-2 can function as a potent trigger for activation of ferroptosis in human placenta. A variety of infectious agents including viruses can influence production of reactive oxygen species, iron metabolism and transport, and antioxidative defenses to a substantially great scope . PatientPlacental susceptibility to ferroptosis highlights a key role of a major cascade of molecular events linking initiation of a pathophysiological condition resulting from SARS-CoV-2 crossing of the placental barrier to ultimate manifestations of pregnancy-related sequalae. Indeed, human placenta can produce a wide array of hormones and cytokines, such as human chorionic gonadotropin and progesterone, to sustain pregnancy, and therefore, placental dysfunction largely accounts for pathogenesis of most adverse pregnancy outcomes. A recent systematic review and meta-analysis on the impact of COVID-19 on pregnancy outcomes involving 42 studies and 438,538 patients concluded that SARS-CoV-2 infection is closely associated with risks of hypertension disorders of pregnancy, intrauterine fetal demise, and preterm birth . In addiin vitro including use of primary cytotrophoblast as the model as well as in vivo animal studies makes it difficult to establish a definitive causal relationship. However, these experiments will be included in our future directions.Some limitations are associated with this study. Because of limited sample size, we were not able to reach a conclusion with respect to a significant trend positively correlating the degree of placental SARS-CoV-2 infection and scopes of ferroptosis activation. Furthermore, the lack of In summary, this study has uncovered that SARS-CoV-2 infection may activate ferroptosis in the human placenta. Thus, pregnant females diagnosed with COVID-19 need to be considered at high risks for adverse clinical outcomes and should be included in all preventive strategies. Moreover, our study provides opportunities to ultimately control and manage adverse pregnancy-related outcomes, which can be facilitated by development of potent and selective chemical compounds and biologics based on specifically targeting markers characteristics of ferroptosis in the placenta. As such, ferroptosis inhibition could constitute a viable strategy to prevent placental injury and insufficiency due to viral infection in the clinical care setting.


Postpartum depression (PPD) and postpartum anxiety (PPA) are often comorbid and are associated with significant personal and economic costs. Fewer than half of the mothers experiencing PPD or PPA symptoms receive face-to-face treatment, suggesting a need for alternative delivery formats such as internet-delivered cognitive behavioral therapy (ICBT).This pilot study aimed to examine the impact of a therapist-assisted, transdiagnostic ICBT program on symptoms of PPD and PPA, as there is only one previous study on transdiagnostic ICBT with this population, which did not include therapist assistance.Wellbeing Course for New Moms) or to treatment as usual (TAU). Clients completed measures of depression, anxiety, stress, postnatal bonding, and relationship satisfaction, as well as measures of treatment satisfaction and therapeutic alliance, before treatment, after treatment, and at the 1-month follow-up. Outcome measures were also completed at the 6-month follow-up for clients who completed the ICBT course.Clients endorsing the symptoms of PPD or PPA (N=63) were randomized to an 8-week transdiagnostic ICBT course , PPD , and depression , and on secondary outcome measures of overall distress , anxiety , and stress . Time-by-group interactions for proportional reductions between groups over time were only significant after treatment and at the 1-month follow-up for the primary anxiety measure (P=.006). This study was underpowered for detecting small or medium effects. Overall, clients perceived the treatment as credible, and 95% (21/22) of the clients were satisfied with the treatment content and therapist support.Both the ICBT and TAU groups experienced statistically significant improvements over time. The ICBT group experienced larger improvements after treatment and at the 1-month follow-up on more measures than the TAU group, with medium between-group Cohen Findings from this pilot study provide preliminary support for transdiagnostic ICBT in treating PPD and PPA symptoms to improve access to psychological treatments.ClinicalTrials.gov NCT04012580; https://clinicaltrials.gov/ct2/show/NCT04012580 In the period following childbirth, women are at an increased risk of experiencing depression and anxiety , with upIn ICBT, clients work through structured web-based psychoeducational and therapeutic materials similar to what would be covered in face-to-face CBT . ICBT isMUMentum Postnatal program was adapted from an existing ICBT program for adults with anxiety and depression. Adaptations included shortening the number of lessons and course duration, modifying psychoeducation throughout to be specifically relevant to postpartum concerns, and providing additional postpartum-relevant resources to accompany each lesson. The program comprised 3 core lessons tailored to new mothers. The program was intended to be completed over a span of 4 weeks and was entirely self-guided, with therapists only contacting new mothers if there were significant elevations in symptoms or suicidality. New mothers (N=87) were randomly assigned to receive either the MUMentumPostnatal program or treatment as usual (TAU). After treatment and at follow-up, new mothers assigned to the treatment group experienced larger improvements in the measures of anxiety, depression, and distress than the new mothers who received TAU. Furthermore, there were moderate but significant differences in measures of bonding and quality of life in favor of the MUMentum Postnatal program over TAU. Adherence rates were high, with 75% of the new mothers completing all 3 lessons, and new mothers were satisfied with the treatment overall. This trial provides preliminary evidence for the efficacy and acceptability of self-guided transdiagnostic ICBT for PPD and PPA. Additional research examining the inclusion of therapist assistance in transdiagnostic ICBT for PPD and PPA is warranted, given the finding that programs with therapist assistance often facilitate greater symptom reduction than self-guided programs [The other notable gap in the literature is that the research on PPA and PPD symptoms has historically been disorder specific in nature ; however, the high rates of comorbidity between PPD and PPA symptoms  suggest programs .Wellbeing Course for New Moms) for new mothers experiencing symptoms of PPD or PPA when delivered by a clinic specializing in the provision of ICBT and providing services on a continuous basis funded by the government. Examining the program in a routine care setting allows for greater generalizability of findings outside the initial research setting in which a program is developed [Wellbeing Course for New Moms with TAU in reducing symptoms of anxiety and depression and improving new mothers’ rated stress, bonding with their infants, and relationship satisfaction. We took an approach similar to that of Loughnan et al [MUMentum Postnatal and Wellbeing Course for New Moms programs differ in terms of length (4 weeks vs 8 weeks), number of lessons (3 lessons vs 5 lessons), therapist support (unguided vs therapist guided), and specific outcome measures . Another objective of this study was to examine new mothers’ satisfaction with the course. The results of this study can also serve as a replication of the findings of the MUMentum Postnatal program [Wellbeing Course for New Moms would show greater improvements in anxiety, depression, stress, bonding with their infants, and relationship satisfaction and that, overall, new mothers would rate the intervention as acceptable. Given the dearth of research examining transdiagnostic ICBT tailored to new mothers, this pilot study offers important insights into how web-based interventions can help address the mental health needs of new mothers.The aim of this pilot study, which was planned before the abovementioned study was published, was to examine the efficacy of a therapist-assisted transdiagnostic program , and the trial was registered at ClinicalTrials.gov (NCT04012580). Participants provided consent at various points during the study, including completing a consent form before filling out the web-based screening, providing verbal consent during the telephone screening, and before initiating the Clients were recruited through web-based advertisements, presentations to health care professionals, and printed promotional materials over a span of 6 months (September 2019 to March 2020). Clients began by visiting the Online Therapy Unit website, where they completed a web-based consent form, initial eligibility questions, and a web-based screening questionnaire. To be eligible for this study, potential clients had to (1) be aged ≥18 years, (2) be female, (3) have given birth and have a child aged <1 year, (4) have a score ≥10 on the Edinburgh Postnatal Depression Scale  or scorClients who met the initial eligibility criteria completed a telephone intake interview with a doctoral student in clinical psychology (VS) or a master’s level social worker (KA). Immediately after being accepted into the trial, clients were randomly assigned to ICBT or TAU. Before recruitment for this study, the primary investigator (VS) generated a random allocation sequence using a randomizer website and specified a 1:1 ratio in blocks of 50. The sequence was produced in the form of a Microsoft Excel file, which was then uploaded directly to the website hosting the web-based screening . After this point, the researchers were unable to view the allocation sequence. Randomization was performed after participants were deemed eligible for this study to limit the possibility of bias in conducting the telephone screen in the event that the randomization group was known. At the end of the telephone screen, the screener informed participants of their allocation.Wellbeing Course for New Moms is a transdiagnostic course based on the principles of CBT. It was adapted from the Wellbeing Course [The g Course  to refleAll clients assigned to ICBT received weekly therapist support from a master-level, registered social worker trained in the provision of ICBT. The therapist contacted clients on the same day each week throughout the 8-week course using secure emails on the Online Therapy Unit’s platform. In this way, communication between the client and therapist was asynchronous, meaning that the sender’s message may not be read until several days later by the receiver. Each therapist message was personalized but included several important elements: warmth and concern, feedback on symptom measures, highlighting key skills, answering client questions about the lessons, acknowledging any stated areas of difficulty, providing encouragement reinforcing progress, managing risk, and reminding clients about course instructions  is a psThe 21-item Depression and Anxiety Stress Scale  is a psThe Postnatal Bonding Questionnaire  is a psThe 7-item Dyadic Adjustment Scale  is a psWellbeing Course for New Moms. The TSQ comprises 6 questions to assess satisfaction with the treatment (very dissatisfied to very satisfied), satisfaction with the quality of the lessons and do-it-yourself guides (very dissatisfied to very satisfied), confidence in recommending the treatment to a friend (yes or no), whether the treatment was worth their time (yes or no), how participating in treatment affected their confidence to manage symptoms (greatly reduced to greatly increased), and how participating in treatment affected their motivation to seek future treatment if needed (greatly reduced to greatly increased).The Treatment Satisfaction Questionnaire  was creyes to these questions, they were asked to explain further. Clients were also asked to indicate whether that event negatively affected their participation, engagement, or benefit from the program.After the treatment, clients were asked to indicate whether they experienced any negative effects, new psychological symptoms, or unwanted events  during the course. If clients answered The Credibility and Expectancy Questionnaire  comprisThe Working Alliance Inventory-Short Revised  was admiAll clients were asked whether they used a number of different services during the previous 8-week period at the posttreatment and 1-month follow-up  time points. Clients in the ICBT treatment group also received these questions at the 6-month follow-up.Descriptive statistics were calculated for demographic and clinical characteristics to summarize the sample and check for pretreatment differences between the conditions. Changes in outcome measures over time were modeled using generalized estimating equations . For ald effect sizes. Proportional improvements and within-group Cohen d effect sizes are also reported for the ICBT treatment group at the 6-month follow-up. Hypothesis tests of differences in improvements between groups were performed using Wald tests on the estimated time×group interaction coefficients from the GEE models.To compare improvements from before treatment to after treatment and at the 1-month follow-up, we calculated proportional improvements from the pretreatment time point and within-group and between-group Cohen Questionnaire completion rates were high in both groups at all observation times . HoweverWellbeing Course for New Moms. Of these 83 individuals, 20 (24%) applications were considered unsuccessful for the following reasons: loss of contact , client’s choice , minimal symptoms of anxiety and depression , elevated suicidal ideation , referred to web-based materials or resources , or participating in another ICBT course . The remaining 63 clients were randomized to either transdiagnostic ICBT  or TAU . In the ICBT group, 3% (1/30) of clients did not start the course, and 3% (1/30) of clients formally withdrew. In the TAU group, 3% (1/33) of clients formally withdrew before completing the pretreatment questionnaires. Completion of posttreatment questionnaires , 1-month follow-up questionnaires , and 6-month follow-up questionnaires  was high. Over the 6-month recruitment period, 83 individuals applied to the P=.13-.99).The average age of the clients was 30.83 (SD 4.29) years. Most clients were White , married or in a common law relationship , and on maternity or parental leave . Furthermore, most clients indicated some level of postsecondary education . The average age of the clients’ infants was 4.63 (SD 3.61) months, and 60% (36/60) of the clients reported having other children. The most common type of reported birth was vaginal , followed by unplanned cesarean  or planned cesarean  sections. Additional demographic information is presented in 56=2.98; P=.01), whereby clients in the TAU group reported greater relationship satisfaction.At intake, clients’ average scores on the EPDS fell within the range of probable depression  and within the moderate range for both the GAD-7  and PHQ-9 . The mean scores on the PBQ and DAS-7 were 18.03 (SD 11.67) and 23.88 (SD 4.88), respectively. The only significant group difference that emerged was on the DAS-7 (td=0.98-1.47), GAD-7 , and PHQ-9 . The TAU group experienced medium improvements after treatment and at the 1-month follow-up on the EPDS , GAD-7 , and PHQ-9 . As indicated in d=0.52-0.65), with the ICBT treatment group having better outcomes. Hypothesis tests on time×group interactions showed that the differences in proportional improvements were only statistically significant on the GAD-7 (P=.006), with the ICBT treatment group having larger improvements. Tests were not significant on the EPDS (P=.20) or PHQ-9 (P=.16). Clients in the ICBT treatment group experienced further improvements on the EPDS , GAD-7 , and PHQ-9  at the 6-month follow-up.d effect sizes were medium on the DASS-21, DASS-21 Anxiety subscale, and DASS-21 Stress subscale; medium to small on the DAS-7; and small on the DASS-21 Depression subscale and the PBQ , DASS-21 Stress subscale (P=.03), and the DAS-7 after treatment (P=.04) but not at the 1-month follow-up. Differences in proportional reductions were not significant after treatment or at the 1-month follow-up on the DASS-21 Anxiety subscale, DASS-21 Depression subscale, or the PBQ.Hypothesis tests on the time×group interactions showed that the differences in proportional improvements were statistically significant for the DASS-21 (P=.18-.99). Comparisons were not possible at the 6-month follow-up as only treatment clients answered these questions.Service use after treatment and at the 1-month and 6-month follow-ups is summarized in P=.59 and P=.44 on the credibility and expectancy factors, respectively). Clients in the ICBT treatment group demonstrated a significant increase in treatment credibility scores after treatment .Wellbeing Course for New Moms (ICBT) or TAU . Medium between-group Cohen d effects were observed in favor of the ICBT condition on most measures of anxiety and depression after treatment and at the follow-ups, with the exception of the depression subscale of the DASS-21. However, when examining the time-by-group interaction comparing differences in proportional reductions from before treatment between ICBT and TAU, the differences were only significant for the GAD-7 both after treatment and at the 1-month follow-up. Owing to the small sample size, this study was underpowered to detect significant differences in recovery rates between the treatment and TAU conditions, which may help explain the difference in findings based on effect sizes compared with time-by-group interactions of the proportional reductions. Improvements on all primary  and most secondary measures (DASS-21 and PBQ) were maintained at the 6-month follow-up in the ICBT group. Finally, clients were satisfied with the ICBT course, perceived it as credible, and expressed high levels of alliance with their therapists.In this study, 63 new mothers were randomized to receive either the MUMentum Postnatal program [MUMentum Postnatal program contained more psychoeducation relevant to new mothers throughout the program  and is a briefer, more condensed treatment than the Wellbeing Course for New Moms, which may be more appropriate for this population, given the time constraints of caring for a new infant.The symptom improvement demonstrated in this sample is consistent with the treatment responses found in the face-to-face CBT literature. Meta-analyses have found statistically significant effects of CBT in the treatment of PPD, and improvements were maintained at the 6-month follow-up ,38. Alth program  is the o program ) and the program ), althou program  self-refGiven the scarcity of published trials examining ICBT for PPA and PPD symptoms, this pilot study makes an important contribution to the literature . A strenWellbeing Course for New Moms during the COVID-19 pandemic; of note, research indicates that the COVID-19 pandemic has led to a substantial increase in the rates of PPD and PPA [Wellbeing Course for New Moms should include larger sample sizes to ensure sufficient power for additional analyses. In future trials, it would be interesting to explore the extent to which individuals with PPA or PPD use additional resources. Finally, this study relied on self-report symptom measures as opposed to engaging participants in structured clinical interviews to ascertain information about their symptoms. Although this is not uncommon in the ICBT literature, it resulted in a lack of clarity regarding the participants’ diagnostic status.Despite the contributions of this pilot study to the literature on ICBT for symptoms of PPA and PPD, this study had several limitations that should be considered when interpreting the results. Owing to the timing of the trial, approximately half of the clients were enrolled in the  and PPA . ClientsThis pilot study is the first known study of therapist-assisted, transdiagnostic ICBT designed to target symptoms of PPD and PPA. We found that the treatment resulted in larger improvements in depression, anxiety, and overall distress relative to a TAU condition when examining between-group effect sizes. However, the time-by-group interaction was significant only for the GAD-7 both after treatment and at the 1-month follow-up. Improvements in primary outcomes in the ICBT group were maintained at the 6-month follow-up. This study provides initial evidence for transdiagnostic ICBT as a potentially accessible, effective, and acceptable treatment for symptoms of PPD and PPA.


Patients with unilateral cleft lip and palate were associated with different nasomaxillary complex from the normal population. Although the biomechanical effects of conventional rapid palatal expansion (Hyrax expansion) and bone-borne rapid palatal expansion (micro-implant-assisted expansion) in non-cleft patients have been identified by multiple studies, little is known in patients with unilateral cleft lip and palate. The purpose of this study was to investigate and compare the biomechanical effects of the conventional and bone-borne palatal expanders in a late adolescence with unilateral cleft lip and palate.A cone beam CT scan of a late adolescence with unilateral cleft lip and palate was selected to construct the three-dimensional finite element models of teeth and craniofacial structures. The models of conventional and born-borne palatal expanders were established to simulate the clinical maxillary expansion. The geometric nonlinear theory was applied to evaluate the Von Mises stress distribution and displacements in craniofacial structures and teeth.Bone-borne palatal expander achieved more transverse movement than conventional palatal expander in the whole mount of craniofacial regions, and the maximum amount of expansion was occurred anteriorly along the alveolar ridge on cleft-side. The expanding force from born-borne palatal expander resulted in more advancement in nasomaxillary complex than it in conventional palatal expander, especially in the anterior area of the minor segment of maxilla. Stresses from the both expanders distributed in similar patterns, but larger magnitudes and ranges were generated using the bone-borne expander around the maxillary buttresses and pterygoid plates of sphenoid bone. The maximum expanding stresses from born-borne palatal expander were concentrated on palatal slope supporting minscrews, whereas those from conventional palatal expander were concentrated on the anchoring molars. In addition, the buccal tipping effect of teeth generated using the bone-borne expander was less than it using the conventional palatal expander.Bone-borne expander generated enhanced skeletal expansion at the levels of alveolar and palate in transversal direction, where the miniscrews contributed increased expanding forces to maxillary buttresses and decreased forces to buccal alveolar. Bone-borne expanders presented a superiority in correcting the asymmetric maxilla without surgical assistant in late adolescence with unilateral cleft lip and palate. Unilateral cleft lip and palate (UCLP) is the most common craniofacial deformity characterized by the dismissed midpalatal suture and defected alveolar bone, which separates the maxillary structures into the minor and major segments. Postnatal surgical repair is a necessary treatment but causes tremendous soft-tissue tensions from scar contracture. This results with the collapse of the maxillary minor segment with mediolingual rotation, anterior crossbite with or without posterior crossbite, and maxillary growth retardation in transverse and sagittal dimensions at later stages , 2. ThusFor patients with maxillary dysplasia in late adolescence, treatment using the combination of protraction facemask and conventional hyrax expander  generates limited effect on the correction of sagittal and transverse deficiencies in maxilla , 4. The In recent years, micro-implant-assisted rapid palatal expansion  was gradually applied, which was proved to be effective in expanding the heavily interdigitated sutures without surgical assistance, and generating less dentoalveolar side effects for late adolescence or even adults , 8, 9. BThe finite element analysis (FEA) is a well-proven mathematical technique for calculating the displacement, internal stress and strain in the craniofacial structures during orthodontics . The traThe CBCT data saved as DICOM-format was selected from an 18-year-old adolescence with UCLP, presenting narrow arch and complete dental crossbite. The CBCT was taken for the examination of pre-orthodontic , approved by the Ethic Committee of School of Stomatology, Lanzhou University . All experiments were performed in accordance with relevant guidelines and regulations.The CBCT data was imported into MIMICS software , in which the craniofacial structures and teeth were seperated. Subsequently, files in STL format were transformed and processed in Geomagic Studio  to generate the high-quality surface meshes. The sutures and PDL were sectioned into 0.2-mm tetrahedrons; the maxilla, dentition, and alveolar bone in the volumetric meshes were sectioned into 1.5-mm tetrahedrons; the remaining skull bones including surrounding sutures were sectioned into 4-mm tetrahedrons using ANSYS 19.0 . Finally, three dimensional meshes were composed of 1,186,791 tetrahedral elements and 1,806,003 nodes (Fig. The design of the conventional hyrax expander model was made as reported by Lee et al. . The bonIn ANSYS 19.0 software, the mechanical properties of the materials in the model were assigned according to the previous studies, as shown in Table The three dimensional displacements of the palatal reference points along the anterior, middle and posterior edges were respectively shown in Table Transversally on the X axis, compared with C-RPE, B-RPE presented an obviously greater displacement on both the cleft and non-cleft sides. The transversal dispalcements were gradually decreased from the anterior to the posterior, presenting a pyramidal expanding Fig. c–d. SagiThe three dimensional displacements of the cusp tips of pre-molars and molars were shown in Table Transversally on the X axis, the B-RPE presented greater expansion than C-RPE, and the maximum displacement was occurred at the tip of first pre-molar on cleft side. Moreover, at periodontal ligament level of the first premolar and molar, the displacement in B-RPE occurred more uniformly than it in C-RPE, indicating less tooth effect generated by the bone-borne expander Figs. e-f and 4The displacement in craniofacial structures was shown in Table Transversally on the X axis, the nasomaxillary complex presented a pyramidal expansion with the base of pyramid at the floor of the alveolar ridges and the apex nearby the frontonasal suture. This results of B-RPE were especially obvious. The maximum lateral movement was occurred at the anterior alveolar ridge on cleft side in B-RPE, and greater than that it in C-RPE Fig. c–d. For The higher stresses exerted from the expanders were distributed in similar patterns around the buttress and lateral borders of maxilla, the inferior and superior borders of nasal cavity, the lateral border of orbits, and the transition regions of pterygoid plates Tables ; Fig. 6.Patients with UCLP usually undergo surgery repair in the early ages, but the postsurgical complications caused by the scar tissue contractions surrounding the musculature are various and common. The mosPrevious studies reported that the magnitude of force generated by expansion device should be highly up to 120 N to activate the separation of palatal suture in normal population. Since tIn this study, the expander was anchored by mini-screws in palatal slope, which was different from the non-cleft patient with the miniscrews symmetrically inserted 3 mm to the midpalatal suture , 13. In Compared with the C-RPE, B-RPE generated increased skeletal expansion, which agreed with the previous studies in non-cleft patients, 27. TheIn this study, compared with the C-RPE, the palatoalvolar and other craniofacial structures also indicated considerable increase in dispalcement using the B-RPE, especially around the regions of inferior maxilla, dental arch and pterygoid plates of sphenoid bone. The maximum total displacement generated by B-RPE occurred in the first pre-molar on cleft side, greater than it in C-RPE. Nata´lia Costa Veloso conducted a retrospective investigation basing on the analysis of CBCT images from 40 adolescences with UCLP, and the result indicated that maxillary changes in C-RPE were restricted to the dentoalveolar region . This reThe biomechanical mechanism and effects of FEA are highly dependent on the quality of the constructed models to simulate the real structure, which can be influenced by the number of elements. In this study, a three dimensional finite element model was consisted of 1,186,791 tetrahedral elements and 1,806,003 nodes, which was far exceeding other relating studies , 18, 20.In late adolescence with UCLP, compared with the conventional tooth-borne expander, bone-borne maxillary expander transmits more transverse expansion forces to surrounding craniofacial structures, while the stresses in periodontal ligament and buccal alveolar are significantly decreased, which is beneficial to avoid the unexpectable alveolar fenestration.Compared with the conventional tooth-borne expander, bone-borne maxillary expander contains more advantages in correcting the mediolingual retraction of minor segment of maxilla, without over displacement in the major segment. Bone-borne maxillary expander is also helpful to correct the vertical deformation of the palatal fornix in posterior region.Bone-borne maxillary expander can enhance the skeletal expansion at the alveolar level and diminish the dental effect, which may serve as an effective device for the nonsurgical treatment of transverse maxillary deficiency in late adolescence with UCLP.