Purpose
Cone‐beam computed tomography (CBCT) scanning is used daily or weekly (i.e., on‐treatment CBCT) for accurate patient setup in image‐guided radiotherapy. However, inaccuracy of CT numbers ...prevents CBCT from performing advanced tasks such as dose calculation and treatment planning. Motivated by the promising performance of deep learning in medical imaging, we propose a deep U‐net‐based approach that synthesizes CT‐like images with accurate numbers from planning CT, while keeping the same anatomical structure as on‐treatment CBCT.
Methods
We formulated the CT synthesis problem under a deep learning framework, where a deep U‐net architecture was used to take advantage of the anatomical structure of on‐treatment CBCT and image intensity information of planning CT. U‐net was chosen because it exploits both global and local features in the image spatial domain, matching our task to suppress global scattering artifacts and local artifacts such as noise in CBCT. To train the synthetic CT generation U‐net (sCTU‐net), we include on‐treatment CBCT and initial planning CT of 37 patients (30 for training, seven for validation) as the input. Additional replanning CT images acquired on the same day as CBCT after deformable registration are utilized as the corresponding reference. To demonstrate the effectiveness of the proposed sCTU‐net, we use another seven independent patient cases (560 slices) for testing.
Results
We quantitatively compared the resulting synthetic CT (sCT) with the original CBCT image using deformed same‐day pCT images as reference. The averaged accuracy measured by mean absolute error (MAE) between sCT and reference CT (rCT) on testing data is 18.98 HU, while MAE between CBCT and rCT is 44.38 HU.
Conclusions
The proposed sCTU‐net can synthesize CT‐quality images with accurate CT numbers from on‐treatment CBCT and planning CT. This potentially enables advanced CBCT applications for adaptive treatment planning.
Since its discovery in the late 1970s, the ubiquitin proteasome pathway appears to be omnipresent in many research fields. Although originally discovered in animals, the pathway has a very central ...role in plants, which may be correlated to their sessile lifestyle. E3 ligases function as flexible and highly diverse key regulators within the path- way by targeting substrate proteins for ubiquitylation, and often proteolytic degradation via the 26S proteasome. This review provides a concise overview on the most common classes of E3 ligases so far described in plants, and emphasizes recent findings regarding these interesting and flexible enzymes and their diverse functions in plant biology.
Dengue is one of the most common vector-borne diseases globally, however, its burden is poorly quantified. Hence, we aimed to report the dengue burden in 195 countries and territories between 1990 ...and 2017, using data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2017.
Following the methodology framework and analytical strategies used in the Global Burden of Disease Study 2017, we analysed the incidence, mortality, and disability-adjusted life years (DALYs) of dengue in geographically defined populations worldwide between 1990 and 2017. We also determined the association between development levels and dengue burden. All estimates were reported as numbers and rates per 100 000 population, with 95% uncertainty intervals.
Globally, the total number of dengue cases increased from 23 283 274 (95% UI 453 180.7–51 840 670) in 1990 to 104 771 911 (95% UI 63 759 019–158 870 031) in 2017. The age-standardised incidence rate increased from 431.6 (8.4–961.0) per 100 000 population in 1990 to 1371.3 (834.5–2079.3) per 100 000 population in 2017. In addition, the number of deaths due to dengue increased from approximately16 957 (7 613–30 091) in 1990 to 40 467 (17 620–49 778) in 2017. Meanwhile, the global age-standardised death rate increased from 0.31 (0.14–0•56) per 100 000 population in 1990 to 0.53 (0.23–0•65) per 100 000 population in 2017. Overall, there were 2 922 630 DALYs (1 629 424–3 967 492) attributed to dengue in 2017 globally, an increase of 107.6% since 1990 (1 407 571 DALYs 624 016.4–2 510 025), and the age-standardised DALY rate increased from 26.10 (11.57–46.53) per 100 000 population to 38.25 (21.33–51.93) per 100 000 population between 1990 and 2017. The association between socio-demographic index (SDI) and dengue-related DALYs suggested that the lowest age-standardised DALY rates were found in countries in the low and high-SDI quintile in 2017, and from 1990 to 2017, the age-standardized DALY rate tended to increase in regions with the lowest SDI but declined in regions with the highest SDI. There was a nonlinear association between the socio-demographic index and the healthcare access and quality index and age-standardised DALY rates.
Dengue is a major public health challenge worldwide. While there is remarkable international variation in its incidence, the dengue burden is increasing globally. The results of this study could be useful for policy makers to implement cost-effective interventions and reduce the dengue burden, particularly in countries with high incidence or increasing burden.
This work was supported by a grant from the National Natural Science Foundation of China (NSFC) (grant numbers 81,800,041 and 82,000,078).
Throughout the course of delivering a radiation therapy treatment, which may take several weeks, a patient's anatomy may change drastically, and adaptive radiation therapy (ART) may be needed. ...Cone-beam computed tomography (CBCT), which is often available during the treatment process, can be used for both patient positioning and ART re-planning. However, due to the prominent amount of noise, artifacts, and inaccurate Hounsfield unit (HU) values, the dose calculation based on CBCT images could be inaccurate for treatment planning. One way to solve this problem is to convert CBCT images to more accurate synthesized CT (sCT) images. In this work, we have developed a cycle-consistent generative adversarial network framework (CycleGAN) to synthesize CT images from CBCT images. This model is capable of image-to-image translation using unpaired CT and CBCT images in an unsupervised learning setting. The sCT images generated from CBCT through this CycleGAN model are visually and quantitatively similar to real CT images with decreased mean absolute error (MAE) from 69.29 HU to 29.85 HU for head-and-neck (H&N) cancer patients. The dose distributions calculated on the sCT by CycleGAN demonstrated a higher accuracy than those on CBCT in a 3D gamma index analysis with increased gamma index pass rate from 86.92% to 96.26% under 1 mm/1% criteria, when using the deformed planning CT image (dpCT) as the reference. We also compared the CycleGAN model with other unsupervised learning methods, including deep convolutional generative adversarial networks (DCGAN) and progressive growing of GANs (PGGAN), and demonstrated that CycleGAN outperformed the other two models. A phantom study has been conducted to compare sCT with dpCT, and the increase of structural similarity index from 0.91 to 0.93 shows that CycleGAN performed better than DIR in terms of preserving anatomical accuracy.
Autophagy has recently emerged as a protective mechanism in response to compressive force and an important process in maintenance of bone homeostasis. It appears to be involved in the degradation of ...osteoclasts, osteoblasts, and osteocytes. The aim of this study was to investigate the role of compressive force-induced autophagy in periodontal ligament (PDL) cells in regulating osteoclastogenesis of orthodontic tooth movement (OTM).
An OTM model and compressive force on PDL cells were employed to investigate the expression of autophagy markers in vivo and in vitro, respectively. Autophagosomes and autolysosomes were observed in PDL cells by transmission electron microscope (TEM) and autophagy LC3 double labelling. 3-Methyladenine (3-MA) and rapamycin were respectively used to inhibit and promote autophagy, and the effect of autophagy on osteoclastogenesis was explored via microcomputed tomography, hematoxylin and eosin (H&E) staining, histochemistry of titrate-resistant acid phosphatase, and real-time polymerase chain reaction (RT-PCR) in vivo. Receptor activator of nuclear factor-kappa B ligand/osteoprotegerin (RANKL/OPG) was investigated by RT-PCR and ELISA in vitro.
Orthodontic force-induced autophagy was prominent on the pressured side of PDL tissues. Administration of 3-MA downregulated bone density and upregulated osteoclasts, while rapamycin had reverse results in OTM. The autophagy activity increased initially then decreased in PDL cells during compressive force application and responded to light force. In PDL cells, administration of 3-MA upregulated while rapamycin downregulated the RANKL/OPG ratio.
Autophagy is activated by compressive force in PDL cells. Besides, it could modulate OTM by negatively regulating osteoclastogenesis and keep bone homeostasis via RANKL/OPG signaling.
COVID-19 vaccines show excellent efficacy in clinical trials and effectiveness in real-world data, but some people still become infected with SARS-CoV-2 after vaccination. This study aimed to ...identify risk factors for post-vaccination SARS-CoV-2 infection and describe the characteristics of post-vaccination illness.
This prospective, community-based, nested, case-control study used self-reported data (eg, on demographics, geographical location, health risk factors, and COVID-19 test results, symptoms, and vaccinations) from UK-based, adult (≥18 years) users of the COVID Symptom Study mobile phone app. For the risk factor analysis, cases had received a first or second dose of a COVID-19 vaccine between Dec 8, 2020, and July 4, 2021; had either a positive COVID-19 test at least 14 days after their first vaccination (but before their second; cases 1) or a positive test at least 7 days after their second vaccination (cases 2); and had no positive test before vaccination. Two control groups were selected (who also had not tested positive for SARS-CoV-2 before vaccination): users reporting a negative test at least 14 days after their first vaccination but before their second (controls 1) and users reporting a negative test at least 7 days after their second vaccination (controls 2). Controls 1 and controls 2 were matched (1:1) with cases 1 and cases 2, respectively, by the date of the post-vaccination test, health-care worker status, and sex. In the disease profile analysis, we sub-selected participants from cases 1 and cases 2 who had used the app for at least 14 consecutive days after testing positive for SARS-CoV-2 (cases 3 and cases 4, respectively). Controls 3 and controls 4 were unvaccinated participants reporting a positive SARS-CoV-2 test who had used the app for at least 14 consecutive days after the test, and were matched (1:1) with cases 3 and 4, respectively, by the date of the positive test, health-care worker status, sex, body-mass index (BMI), and age. We used univariate logistic regression models (adjusted for age, BMI, and sex) to analyse the associations between risk factors and post-vaccination infection, and the associations of individual symptoms, overall disease duration, and disease severity with vaccination status.
Between Dec 8, 2020, and July 4, 2021, 1 240 009 COVID Symptom Study app users reported a first vaccine dose, of whom 6030 (0·5%) subsequently tested positive for SARS-CoV-2 (cases 1), and 971 504 reported a second dose, of whom 2370 (0·2%) subsequently tested positive for SARS-CoV-2 (cases 2). In the risk factor analysis, frailty was associated with post-vaccination infection in older adults (≥60 years) after their first vaccine dose (odds ratio OR 1·93, 95% CI 1·50–2·48; p<0·0001), and individuals living in highly deprived areas had increased odds of post-vaccination infection following their first vaccine dose (OR 1·11, 95% CI 1·01–1·23; p=0·039). Individuals without obesity (BMI <30 kg/m2) had lower odds of infection following their first vaccine dose (OR 0·84, 95% CI 0·75–0·94; p=0·0030). For the disease profile analysis, 3825 users from cases 1 were included in cases 3 and 906 users from cases 2 were included in cases 4. Vaccination (compared with no vaccination) was associated with reduced odds of hospitalisation or having more than five symptoms in the first week of illness following the first or second dose, and long-duration (≥28 days) symptoms following the second dose. Almost all symptoms were reported less frequently in infected vaccinated individuals than in infected unvaccinated individuals, and vaccinated participants were more likely to be completely asymptomatic, especially if they were 60 years or older.
To minimise SARS-CoV-2 infection, at-risk populations must be targeted in efforts to boost vaccine effectiveness and infection control measures. Our findings might support caution around relaxing physical distancing and other personal protective measures in the post-vaccination era, particularly around frail older adults and individuals living in more deprived areas, even if these individuals are vaccinated, and might have implications for strategies such as booster vaccinations.
ZOE, the UK Government Department of Health and Social Care, the Wellcome Trust, the UK Engineering and Physical Sciences Research Council, UK Research and Innovation London Medical Imaging and Artificial Intelligence Centre for Value Based Healthcare, the UK National Institute for Health Research, the UK Medical Research Council, the British Heart Foundation, and the Alzheimer's Society.
Abstract
Selective paraffin capture from olefin/paraffin mixtures could afford high-purity olefins directly, but suffers from the issues of low separation selectivity and olefin productivity. Herein, ...we report an ultramicroporous material (PCP-IPA) with parallel-aligned linearly extending isophthalic acid units along the one-dimensional channel, realizing the efficient production of ultra-high purity C
2
H
4
and C
3
H
6
(99.99%). The periodically expanded and parallel-aligned aromatic-based units served as a paraffin nano-trap to contact with the exposed hydrogen atoms of both C
2
H
6
and C
3
H
8
, as demonstrated by the simulation studies. PCP-IPA exhibits record separation selectivity of 2.48 and separation potential of 1.20 mol/L for C
3
H
8
/C
3
H
6
(50/50) mixture, meanwhile the excellent C
2
H
6
/C
2
H
4
mixture separation performance. Ultra-high purity C
3
H
6
(99.99%) and C
2
H
4
(99.99%) can be directly obtained through fixed-bed column from C
3
H
8
/C
3
H
6
and C
2
H
6
/C
2
H
4
mixtures, respectively. The record C
3
H
6
productivity is up to 15.23 L/kg from the equimolar of C
3
H
8
/C
3
H
6
, which is 3.85 times of the previous benchmark material, demonstrating its great potential for those important industrial separations.
Lymph node metastasis (LNM) is a significant prognostic factor in patients with head and neck cancer, and the ability to predict it accurately is essential to optimizing treatment. Positron emission ...tomography (PET) and computed tomography (CT) imaging are routinely used to identify LNM. Although large or highly active lymph nodes (LNs) have a high probability of being positive, identifying small or less reactive LNs is challenging. The accuracy of LNM identification strongly depends on the physician's experience, so an automatic prediction model for LNM based on CT and PET images is warranted to assist LMN identification across care providers and facilities. Radiomics and deep learning are the two promising imaging-based strategies for node malignancy prediction. Radiomics models are built based on handcrafted features, while deep learning learns the features automatically. To build a more reliable model, we proposed a hybrid predictive model that takes advantages of both radiomics and deep learning based strategies. We designed a new many-objective radiomics (MaO-radiomics) model and a 3D convolutional neural network (3D-CNN) that fully utilizes spatial contextual information, and we fused their outputs through an evidential reasoning (ER) approach. We evaluated the performance of the hybrid method for classifying normal, suspicious and involved LNs. The hybrid method achieves an accuracy (ACC) of 0.88 while XmasNet and Radiomics methods achieve 0.81 and 0.75, respectively. The hybrid method provides a more accurate way for predicting LNM using PET and CT.
Abstract
Background
The current study was conducted to investigate the individual and combined occurrence of aflatoxin B
1
(AFB
1
), deoxynivalenol (DON) and zearalenone (ZEN) in feeds from various ...Provinces of China during 2018 to 2020. A total of 3,507 feed samples, including 2,090 feed ingredients and 1,417 complete feed samples, were collected from different areas of China for mycotoxins analysis.
Results
The individual contamination of AFB
1
, DON and ZEN were present in more than 81.9%, 96.4% and 96.9% of feed samples, respectively, with average concentration ranges of AFB
1
between 1.2–27.4 μg/kg, DON between 458.0–1,925.4 μg/kg and ZEN between 48.1–326.8 μg/kg. Notably, 0.9%, 0.5% and 0.1% of feed ingredients, and 1.2–12.8%, 0.9–2.9% and 0–8.9% of complete feeds for pigs, poultry and ruminants with AFB
1
, ZEN and DON that exceeded China’s safety standards, respectively. Moreover, more than 81.5% of feed ingredients and 95.7% of complete feeds were co-contaminated with various combinations of these mycotoxins.
Conclusion
This study indicates that the feeds in China were universally contaminated with AFB
1
, DON and ZEN during the past 3 years. These findings highlight the significance of monitoring mycotoxin contaminant levels in the domestic animal feed, and the importance of carrying out feed administration and remediation strategies for mycotoxin control.
Arynes are known to serve as highly reactive benzene-based synthons, which have gained numerous successes in preparing functionalized arenes. Due to the superb electrophilic nature of these fleeting ...species, however, it is challenging to modulate the designated aryne transformation chemoselectively, when substrates possess multiple competing reaction sites. Here, we showcase our effort to manipulate chemoselective control between two major types of aryne transformations using either 3-methoxybenzyne or 3-silylbenzyne, where nucleophilic addition-triggered reactions and non-polar pericyclic reactions could be differentiated. This orthogonal chemoselective protocol is found to be applicable between various nucleophiles, i.e., imidazole, N-tosylated/N-alkyl aniline, phenol, and alcohol, and an array of pericyclic reaction partners, i.e., furan, cyclopentadiene, pyrrole, cycloheptatrienone, and cyclohexene. Beyond arylation reactions, C-N bond insertion, Truce-Smiles rearrangement, and nucleophilic annulation are appropriate reaction modes as well. Moreover, this chemoselective protocol can find potential synthetic application.
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