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Electric-field (EF) microsensors with high resolution are crucial for the realization of real-time dynamic status monitoring of Ubiquitous Power Internet of Things (UPIoT), which is of great significance for the safe operation of power system and early-stage diagnostics of power equipment. Distortion-free and high-resolution measurement of electric fields is also important in applications such as meteorological monitoring and aerospace launch. Existing electric-field measurement methods are always costly, bulky, and low in resolution. We presented a capacitive EF sensor with small size and high resolution. The presented sensor is based on piezoelectric effect, and a micro cantilever structure is realized using microfabrication. Simulation and experimental results indicate that the presented sensor has a resolution of about 45 V/m and a measurable magnitude of over 1.5 MV/m. Owing to the characteristics of small size, low cost and low power consumption, the EF sensor is suitable for applications of large-scale sensing arrays.

Background The aim of the present study was to explore the brain active characteristics of patients with irritable bowel syndrome with diarrhea (IBS-D) using resting-state functional magnetic resonance imaging technology. Methods Thirteen IBS-D patients and fourteen healthy controls (HC) were enrolled. All subjects underwent head MRI examination during resting state. A voxel-based analysis of fractional amplitude of low frequency fluctuation (fALFF) maps between IBS-D and HC was performed using a two-sample t-test. The relationship between the fALFF values in abnormal brain regions and the scores of Symptom Severity Scale (IBS-SSS) were analyzed using Pearson correlation analysis. Results Compared with HC, IBS-D patients had lower fALFF values in the left medial superior frontal gyrus and higher fALFF values in the left hippocampus and right precuneus. There was a positive correlation between the duration scores of IBS-SSS and fALFF values in the right precuneus. Conclusion The altered fALFF values in the medial superior frontal gyri, left hippocampus and right precuneus revealed changes of intrinsic neuronal activity, further revealing the abnormality of gut-brain axis of IBS-D.

Background The coronavirus disease 2019 (COVID-19) has brought a global disaster. Quantitative lesions may provide the radiological evidence of the severity of pneumonia and further to assess the effect of comorbidity on patients with COVID-19. Methods 294 patients with COVID-19 were enrolled from February, 24, 2020 to June, 1, 2020 from six centers. Multi-task Unet network was used to segment the whole lung and lesions from chest CT images. This deep learning method was pre-trained in 650 CT images (550 in primary dataset and 100 in test dataset) with COVID-19 or community-acquired pneumonia and Dice coefficients in test dataset were calculated. 50 CT scans of 50 patients (15 with comorbidity and 35 without comorbidity) were random selected to mark lesions manually. The results will be compared with the automatic segmentation model. Eight quantitative parameters were calculated based on the segmentation results to evaluate the effect of comorbidity on patients with COVID-19. Results Quantitative segmentation model was proved to be effective and accurate with all Dice coefficients more than 0.85 and all accuracies more than 0.95. Of the 294 patients, 52 (17.7%) patients were reported having at least one comorbidity; 14 (4.8%) having more than one comorbidity. Patients with any comorbidity were older (P P P P P Conclusions Multi-task Unet network can make quantitative CT analysis of lesions to assess the effect of comorbidity on patients with COVID-19, further to provide the radiological evidence of the severity of pneumonia. More lesions (including GGO and consolidation) were found in CT images of cases with comorbidity. The more comorbidities patients have, the more lesions CT images show.

BACKGROUND Pulmonary tumorlets are nodular hyperplastic neuroendocrine cells (NECs) that extend beyond the basement membrane. They often coexist with other lung diseases such as fibrosis and bronchiectasis, but rarely accompanied by pulmonary sclerosing pneumocytoma (PSP), which has not been reported in the literature. CASE SUMMARY A 54-year-old woman was admitted to the hospital because she had symptoms of bloody sputum for more than 4 mo and hemoptysis for 1 wk. Computed tomography images showed atrophy accompanied by infections in the middle lobe of her right lung. Moreover, numerous nodules were identified in the middle lobe of the right lung. The patient underwent thoracoscopic pneumonectomy of the middle lobe of the right lung, and the resected mass was pathologically confirmed to have bronchiectasis, multifocal NEC hyperplasia accompanied by tumorlet, and PSP. CONCLUSION Our report presents a rare clinical case of bronchiectasis complicated with multifocal NEC hyperplasia, tumorlet, and PSP.

Electric power sensing devices and networks have become one of the most important infrastructures of smart grids. As a basic component of smart grids, there is an urgent need to develop non-contact, wide-range, wide-band and low-cost miniature electric field sensors. This paper proposes a micro electric field sensor based on luminous flux sensing device deformation. The mathematical theory and finite element simulation software are used to predict and evaluate the sensing performance. The influence of each parameter on the performance of the device is analyzed as well. Experiment results show that the sensor, can achieve a stably electric field measure at a range of 19 kV/m - 10.62 MV/m, and has a frequency bandwidth of 71 Hz with 3 dB attenuation. Besides, it has the advantages of high sensitivity, high measurement accuracy, low cost and very limited interference from stray capacitance. It can realize the measurement of DC and AC power frequency electric fields.

UHV DC line arrester long length, there is a significant electric field distribution uniformity. This paper establishes a simulation analysis model for the electric field distribution of the UHV DC line arrester, and systematically studies the influence of measures such as adjusting the structure and the dielectric constant of the arrester valve disc on the electric field distribution of the arrester. It shows that the combination of different dielectric constants of arrester valves can significantly improve the electric field distribution of the arresters in UHV DC lines.

When the Ultra High Voltage Direct Current (UHV DC) line is struck by lightning, it may cause the protection action of the DC system. In this paper, a simulation analysis model of the lightning transient process of UHV DC line is established, and the influence of the line arrester and its installation position and quantity on the protection action is systematically studied. The research results show that line arresters can reduce the impact of lightning overvoltage on UHV DC system protection and prevent lightning strikes from causing DC system protection under certain conditions. The more line arresters are installed along the line, the more significant the effect.

Background The coronavirus disease 2019 (COVID-19) is a pandemic now, and the severe COVID-19 determines the management and treatment, even prognosis. Thus, we aim to develop and validate a radiomics nomogram for identifying severe patients with COVID-19.Methods There were 156 and 104 patients with COVID-19 enrolled in primary and validation cohorts respectively. Radiomics features were extracted from chest CT images. Least absolute shrinkage and selection operator (LASSO) method was used for feature selection and radiomics signature building. Multivariable logistic regression analysis was used to develop a predictive model, and the radiomics signature, abnormal WBC counts, and comorbidity were incorporated and presented as a radiomics nomogram. The performance of the nomogram was assessed through its calibration, discrimination, and clinical usefulness.Results The radiomics signature consisting of 4 selected features was significantly associated with clinical condition of patients with COVID-19 in the primary and validation cohorts (P Conclusions We present an easy-to-use radiomics nomogram to identify the severe patients with COVID-19 for better guiding a prompt management and treatment.

Background The novel coronavirus pneumonia (coronavirus disease 2019, COVID-19) has spread around the world. We aimed to recapitulate the clinical and CT imaging features of COVID-19 and their differences in three age groups. Methods The clinical and CT data of patients with COVID-19 (n = 307) that had been divided into three groups (Group 1: Results Of all patients, 114 (37.1%) had histories of epidemiological exposure, 48 (15.6%) were severe/critical cases, 31 had hypertension (10.1%), 15 had diabetes mellitus (4.9%), 3 had chronic obstructive pulmonary disease (COPD, 1%). Among the three groups, severe/critical type, hypertension and diabetes occurred more commonly in the elderly group compared with Group 1&2 (P P P P Conclusions COVID-19 presented representative clinical manifestations, laboratory examinations and CT findings, but three age groups possessed their own specific characteristics. Grasping the clinical and CT features stratified by age will be helpful for early definite diagnosis of COVID-19.

Purpose: To explore the value of the apparent diffusion coefficient (ADC) in assessing preoperative T staging of low rectal cancer and the correlation between ADC value and Ki-67 expression. Methods: Data on 77 patients with a proven pathology of low rectal cancer were retrospectively analyzed. All patients underwent a magnetic resonance imaging scan 1 week prior to operation, and the mean ADC value was measured. All tumors were fully removed, and pathologic staging was determined. The Ki-67 expression was determined using immunohistochemical methods in all patients. The correlation between Ki-67 expression and ADC features was studied. Results: A total of 77 patients with low rectal cancer were included in the study. The pathology type was adenocarcinoma. The numbers of patients with pathological stages T1, T2, T3, and T4 were 9, 23, 32, and 13, respectively. The ADC value of all tumors ranged from 0.60 to 1.20 mm2/s. The average Ki-67 proliferation index was 55.3% ± 20.2%. A significant difference was observed between the preoperative ADC value and pathological T staging of low rectal cancer ( P < .01). The more advanced the T stage, the lower the detected ADC values were. A negative correlation was noted between the preoperative ADC value and Ki-67 proliferation index of rectal cancer ( r = −0.71, P < .01). When the Ki-67 proliferation index increased, lower ADC values were detected. Conclusion: The ADC values can provide useful information on preoperative tumor staging and may facilitate evaluation of the biological behavior of low rectal cancer. The ADC values should be considered a sensitive image biomarker of rectal cancer.

A 16-year-old boy was admitted to our hospital due to sudden pale face and chest pain for half-an-hour. He could not express properly because of hypophrenia. Other examinations revealed congenital cataract in the right eye, as well as nystagmus and generalized hypotonia. He had signs of ataxia, and, though without deformity in any limb, was unable to complete the straight-line walking test. Five years ago, the boy was abandoned to a welfare home. The caretaker of the welfare home complained that the boy had several times of episodic hyperpnea, every 1–2 h, each lasting for about 10–40 s, during the night sleep. Ultrasonography of liver, cholecyst, pancreas, spleen, kidney and heart showed no abnormal findings. Electrocardiogram showed sinus arrhythmia.

Rationale: Malignant melanoma predominantly develops in middle-aged and older adults, most commonly occurring on the skin and rarely on internal organs. Malignant melanoma originating in the liver is extremely rare. Imaging findings of primary hepatic melanoma (PHM) are scarce in relevant literature. Patient concerns: The patient was a 69-year-old woman from Zhejiang, China, who was admitted to the hospital because of upper abdominal pain that persisted for >10 days. Diagnoses: Computed tomography (CT) findings indicated the presence of a circular low-density shadow of approximately 7.5 × 8.0 cm in the hepatic hilar region. Magnetic resonance imaging (MRI) indicated a heterogeneous solid cystic mass in the hepatic hilar region. The mass exhibited heterogeneous low-signal intensity on a T1-weighted image (T1WI) and slightly higher signal intensity on a T2-weighted image (T2WI). The tumor appeared as multiple irregular strips with high-signal intensity on T1WI and low-signal intensity on T2WI. The diffusion-weighted image revealed increased signal intensity. The tumor continued to be enhanced after enhancement. Clinical data suggested that the tumor was a malignant liver tumor. Interventions: The patient underwent a CT guide puncture hepatic biopsy. The tumor was located in the hepatic hilar region adjacent to the large blood vessels and invaded the portal vein. Because a resection was highly risky, conservative treatment was conducted. Outcomes: Postoperative pathology and clinical examination confirmed that the tumor was malignant PHM. The patient has been followed up for 6 months. The patient underwent CT reexamination 2 months after conservative treatment, the results of which revealed that the tumor progressed. Multiple lesions were identified; moreover, the tumor size had increased and the tumor had invaded the portal vein and intrahepatic bile duct. The patient was reexamined by CT in another hospital 6 months after conservative treatment. The results revealed peritoneal, omental metastases and multi bone metastases. Lessons: To our best knowledge, this is the first reported case of a PHM with complete imaging data, including preoperative CT and MRI examinations and a follow-up CT examination. From compiling the CT and MRI findings of this patient and those of relevant studies, this study can serve as a reference for the preoperative diagnosis and differential diagnosis of PHM.

To retrospectively analyze the computed tomography (CT) findings and clinical manifestations of gastric calcifying fibrous tumor (CFTs). The features of 7 cases with pathologically proven gastric CFTs who had undergone CT were assessed, including tumor location, contour, growth, degree of enhancement, calcification and clinical data. In addition, the size and CT value of each lesion were measured. The mean values of these CT findings and clinical data were statistically analyzed only for continuous variables. Four patients were female and three were male (mean age: 33.3 years; range: 22 ∼ 47 years). Nonspecific clinical symptoms: abdominal pain and discomfort were observed in four cases and the CFTs were incidentally detected in the other three cases. Regarding tumor markers, lower ferritin levels were observed in three female patients. All of the gastric CFTs were solitary and mainly located inside the body; they were in round or oval shape and exhibited endophytic growth. Gastric CFTs are usually small sized and could contain confluent and coarse calcifications; cyst, necrosis, ulcer, bleeding and surrounding lymphadenopathy were not found in any of the cases. Unenhanced CT values of gastric CFTs were higher than those of same-transect soft tissue. Mild-to-moderate enhancement in the arterial phase and progressive enhancement in the portal venous phase were mainly noted. A gastric mass with a high unenhanced CT attenuation value, confluent and coarse calcifications and mild-to-moderate enhancement could prompt a diagnosis of gastric CFT. In addition, (1) being young- or middle-aged, (2) having relatively low ferritin levels, and (3) tumor located in the gastric body have critical reference value for diagnosis of gastric CFT.

Rationale Intrauterine devices (IUDs) are one of the most common and effective methods of contraception worldwide. Migration of an IUD to an extrauterine site is a rare complication. The aim of this study was to report an extremely rare case in which an IUD was found in an ovarian tumor. Patient concerns A 63-year-old Chinese woman presented with vaginal bleeding and lower abdominal pain during hospitalization due to pneumonia. Preoperative imaging showed bilateral cystic masses in the adnexal region, and ring hyperdensity was found in the right ovarian mass. Endometrial thickening and multiple uterine leiomyomas were found on ultrasonography. Hysteroscopy showed partial septate uterus and a small endometrial polyp. Diagnosis Bilateral ovarian cystadenomas with perforation of the IUD into the right ovarian tumor were considered based on preoperative imaging and the patient's medical history. Furthermore, early endometrial carcinoma was suspected. Interventions The patient underwent hysterectomy, bilateral salpingo-oophorectomy, and omentectomy. A stainless steel ring IUD was confirmed within the right ovarian tumor during the operation. Outcomes The pathology results demonstrated bilateral ovarian serous cystadenofibromas with focal epithelial proliferation and endometrial atypical hyperplasia with malignant transformation. The patient has been followed up for 7 months, and there has been no recurrence at present. Lessons The presence of an IUD within an ovarian tumor is extremely rare. This is the second reported case in the English literature describing an extrauterine IUD within an ovarian tumor. The correlation between ovarian cancer tumorigenesis and IUD translocation is unclear and requires further investigation.

An analytical model has been developed for analyzing the braking torque in electromagnetic retarder by flux tube and armature reaction method. The magnetic field distribution in air gap, the eddy current induced in the rotor and the braking torque are calculated by the developed model. Two-dimensional and three-dimensional finite element models for retarder have also been developed. Results from the analytical model are compared with those from finite element models. The validity of these three models is checked by the comparison of the theoretical predictions and the measurements from an experimental prototype. The influencing factors of braking torque have been studied.

Objectives This study assessed image quality and radiation dose of multidetector computed tomography (CT) examination using a standard protocol and a low-voltage protocol. Methods Patients requiring contrast-enhanced abdominal CT examination were randomly assigned to two groups with different voltage protocols: (i) 120 kV; (ii) an automated attenuation-based tube potential optimization mode (CARE kV). The volume CT dose index (CTDIvol) and dose length product (DLP) were recorded. Image quality was semiquantitatively assessed by two blinded radiologists using a five-point scale. Results There were 39 patients in the 120 kV group and 50 patients in the CARE kV group. There was no obvious difference in image quality score between the groups. CARE kV resulted in a voltage reduction to 100 kV in 45 patients and to 80 kV in five patients. CTDIvol and DLP were significantly lower with CARE kV than with the 120 kV protocol. Conclusions The use of CARE kV reduces radiation dose with no loss of image quality compared with a standard 120 kV protocol.

Rationale:Primary hyperparathyroidism (PHPTI) with respiratory tract symptom is extremely rare. It is caused by autonomic oversecretion of parathyroid hormone (PTH) owing to parathyroid adenoma, hyperplasia, or tumor. The diagnosis of PHPTI often needs to be made based on medical history, cl

Jade is a apart of traditional culture in our country. With the development of the times, jade culture is gradually weakened, in order to make it inherit, carry forward the Chinese traditional jade carving in this technology age, many colleges and universities in our country carried out jade craving courses in the professional level; however, at present, Chinese jade in the professional teaching situation is not optimistic, many issues remains, is not conducive to jade craving culture This article conduct analysis on the professional education for jade craving, and to explore some effective method for jade craving in the reform of the teaching system, train more professional jade in the talents for our country, and push forward the Chinese jade culture.

The spleen is one of the most commonly involved organs of visceral leishmaniasis (VL). However, there were few reports about imaging findings of splenic leishmaniasis, especially regarding MRI findings. This case report describes a 45 years old male patient from Zhejiang province of southeastern China, who was admitted for persistent fever of unknown origin, with splenomegaly and multiple hypodense/low echo nodules on CT/ultrasonography (USG) studies. MRI showed multiple nodules with concentric rings in the spleen on T2-weighted imaging (T2WI), with no obvious diffusion restriction on diffusion weighted imaging (DWI), and gradual ring-like enhancement after intravenous administration of contrast medium. So MRI suggested necrotic granulomatous lesion. By reviewing the clinical history and following positive serological leishmania antibody test, the patient was finally confirmed a recent infection with VL. The patient received antimony gluconate therapy intravenously. At 4 months follow-up, the contrast-enhanced abdominal MRI showed that the size of the spleen was returned to normal and the splenic lesions were completely resolved except for reduced infarction compared with the previous MRI. This is the first case which was performed MRI examination completely. Meanwhile, it is the second case which MRI findings were reported. As for the characteristics of MRI in this case, there are several features, which are helpful for giving the diagnosis and differential diagnosis of VL.

Scimitar syndrome is a rare, complex congenital anomaly characterized by an anomalous connection of the pulmonary vein with the inferior vena cava (IVC). A persistent left superior vena cava (PLSVC) is another thoracic venous anomaly. We present a rare case with scimitar syndrome associated with the PLSVC. These variations were confirmed by magnetic resonance imaging (MRI) and computed tomography (CT). The typical features and the embryonic development of these variations are described. Radiological evaluations and clinical implications are discussed.