In this article, a novel slot-array defected ground structure (DGS) for decoupling microstrip antenna array is proposed. The slot-array DGS is etched surrounding each antenna element on the ground ...plane and parallel to the radiating edges of each antenna element. The decoupling mechanism is elucidated via an equivalent circuit model and the coupled current field analysis, which reveals slot-array DGS has the spatial band-stop characteristic and changes the direction of the partially coupled current, respectively. Both characteristics of the slot-array DGS contribute to mutual coupling reduction. Three practical design examples of applying slot-array DGS to single-linearly polarized (LP), dual-LP, and compact circularly polarized (CP) antenna array are given to illustrate the design process and considerations. The simulated and measured results show that about 50 dB isolation enhancement is obtained by using the slot-array DGS when the edge-to-edge spacing between CP antenna elements is 0.057 wavelength. Additionally, a wheel-shaped absorber based on the electromagnetic loss material is designed and fabricated to reduce the backward radiation caused by slot-array DGS. The absorber has an absorptivity of more than 95% in the frequency range of 1.2-1.35 GHz and suppresses the backward radiation over 12.5 dB in the plane phi = 0° and 16.1 dB in the plane phi = 90° without deteriorating other antenna performances.
Erdheim-Chester disease (ECD) is a rare histiocytosis that was recently recognized as a neoplastic disorder owing to the discovery of recurrent activating MAPK (RAS-RAF-MEK-ERK) pathway mutations. ...Typical findings of ECD include central diabetes insipidus, restrictive pericarditis, perinephric fibrosis, and sclerotic bone lesions. The histopathologic diagnosis of ECD is often challenging due to nonspecific inflammatory and fibrotic findings on histopathologic review of tissue specimens. Additionally, the association of ECD with unusual tissue tropism and an insidious onset often results in diagnostic errors and delays. Most patients with ECD require treatment, except for a minority of patients with minimally symptomatic single-organ disease. The first ECD consensus guidelines were published in 2014 on behalf of the physicians and researchers within the Erdheim-Chester Disease Global Alliance. With the recent molecular discoveries and the approval of the first targeted therapy (vemurafenib) for BRAF-V600-mutant ECD, there is a need for updated clinical practice guidelines to optimize the diagnosis and treatment of this disease. This document presents consensus recommendations that resulted from the International Medical Symposia on ECD in 2017 and 2019. Herein, we include the guidelines for the clinical, laboratory, histologic, and radiographic evaluation of ECD patients along with treatment recommendations based on our clinical experience and review of literature in the molecular era.
Langerhans cell histiocytosis (LCH) can affect children and adults with a wide variety of clinical manifestations, including unifocal, single-system multifocal, single-system pulmonary ...(smoking-associated), or multisystem disease. The existing paradigms in the management of LCH in adults are mostly derived from the pediatric literature. Over the last decade, the discovery of clonality and MAPK-ERK pathway mutations in most cases led to the recognition of LCH as a hematopoietic neoplasm, opening the doors for treatment with targeted therapies. These advances have necessitated an update of the existing recommendations for the diagnosis and treatment of LCH in adults. This document presents consensus recommendations that resulted from the discussions at the annual Histiocyte Society meeting in 2019, encompassing clinical features, classification, diagnostic criteria, treatment algorithm, and response assessment for adults with LCH. The recommendations favor the use of 18F-Fluorodeoxyglucose positron emission tomography-based imaging for staging and response assessment in the majority of cases. Most adults with unifocal disease may be cured by local therapies, while the first-line treatment for single-system pulmonary LCH remains smoking cessation. Among patients not amenable or unresponsive to these treatments and/or have multifocal and multisystem disease, systemic treatments are recommended. Preferred systemic treatments in adults with LCH include cladribine or cytarabine, with the emerging role of targeted (BRAF and MEK inhibitor) therapies. Despite documented responses to treatments, many patients struggle with a high symptom burden from pain, fatigue, and mood disorders that should be acknowledged and managed appropriately.
POEMS syndrome is a rare plasma cell dyscrasia. This study compared the responses to and survival of 347 POEMS syndrome patients given three first-line treatment regimens: autologous stem cell ...transplantation (ASCT, N = 165) and melphalan + dexamethasone (MDex, N = 79), or lenalidomide + dexamethasone (LDex, N = 103). After a median 45-month follow-up, overall hematologic complete remission (CR
) was 46.4%, vascular endothelial growth factor complete remission (CR
) was 55.1%, and neurological remission (R
) was 93.8%. CR
was better with ASCT (49.7%) than with MDex (37.7%, p = 0.001). CR
was better with ASCT (66.2%) than with MDex (38.5%, p = 0.001) or LDex (47.7%, p = 0.008). Differences in R
achieved by three regimens (91.5% vs. 100% vs. 93.8%, p = 0.234) were not significant. Overall 3-year progression-free survival (PFS) was 80.5% and overall 3-year overall survival (OS) was 90.8%. PFS was 87.6% with ASCT and 64.9% with LDex (p = 0.003). OS in the three regimens did not differ (p = 0.079). In medium-high risk patients, ASCT had better CR
and CR
than MDex, and better PFS than LDex. Therefore, although all three treatments had reasonable responses and survivals, patients with higher risk may benefit more from ASCT treatment.
The direct torque control (DTC) method was introduced into the switched reluctance motor to reduce its inherent output torque ripple. However, the conventional DTC method produces negative torque ...more or less, which reduces the torque-ampere ratio of motors. This paper proposes a new DTC method by three improvements. First, the hysteresis-loop control of flux is removed. New selection rule of voltage vectors is established to reduce the torque ripple. Second, the sectors divided in electrical space are reorganized by their actual positions according to the inductance profile. The boundaries between certain sectors are calculated and updated according to real-time working conditions. Finally, the alternative voltage vectors for increasing or decreasing torque are distinguished by whether any phase is excited. Therefore, the output torque tracks the reference accurately, which reduces the torque ripple. Moreover, the negative torque is avoided by the real-time regulation of the turn- off angle, and the torque-ampere ratio is increased accordingly. Simulation and experimental results verify the demonstrated performance of the proposed DTC method.
Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome is a rare plasma dyscrasia without standard treatment. This phase II prospective trial evaluates ...the safety and response of 12 cycles of low dose lenalidomide (10 mg) plus dexamethasone (Rdex) in patients with newly diagnosed POEMS syndrome. Forty‐one patients (28 men) were enrolled and the median age at diagnosis was 49 years (range, 21‐70 years). Twenty‐one patients (46%) achieved complete hematologic response and the neurologic response rate was 95%. The median serum vascular endothelial growth factor (VEGF) declined from 5155 pg/mL (range, 534‐14 328 pg/mL) to 832 pg/mL (95‐6254 pg/mL) after therapy. The overall VEGF response rate was 83%, and the median time to response was 2 months, with a mean VEGF reduction of 43% at the first month. In terms of clinical response, Rdex substantially relieved extravascular volume overload, organomegaly, and pulmonary hypertension. No treatment‐related deaths occurred and no patients suffered from lenalidomide‐related grade 3 or above adverse events. After a median follow‐up of 34 months, median overall survival (OS) and progression‐free survival (PFS) were not reached, with an estimated 3‐year OS and PFS of 90% and 75%, respectively. In conclusion, Rdex was active with high hematologic, VEGF and organ response rate and well tolerated for patients with newly diagnosed POEMS syndrome. This trial was registered at www.clinicaltrials.gov as #NCT01816620.
Summary
Erdheim–Chester disease (ECD) is a rare form of non‐Langerhans cell histiocytosis that typically affects many organs, including the lung and pleura. However, there are few studies concerning ...pulmonary involvement in ECD patients, as well as the difference of pulmonary involvement between ECD and Langerhans cell histiocytosis (LCH). We performed a retrospective study of 54 ECD patients, and compared the pulmonary manifestations with those of adult LCH patients in our centre. The median age of diagnosis of the 54 ECD patients was 48 years (range 9–66 years). Chest computed tomography (CT) scans revealed lung involvement in 49 (91%) patients and pleural involvement in 34 (63%). Thirty‐three (61%) patients had interstitial lung disease (ILD) with varying degrees of interlobular septal thickening, micronodules, and ground‐glass opacities. ECD and LCH patients with pulmonary involvement showed significant differences in smoking status (P < 0·001), respiratory symptoms (P = 0·001) such as cough and pneumothorax (P < 0·001), and radiological findings, including cysts (P < 0·001), opacities (P < 0·001), and pleural thickening (P < 0·001). With a median follow‐up duration of 24 months (range, 1–84 months), the estimated three‐year overall survival (OS) of this entire ECD cohort was 90·2%. Patients with ILD tended to have worse progression‐free survival (PFS) than those with no ILD (P = 0·29).
Adult Langerhans cell histiocytosis (LCH) remains poorly defined. We retrospectively studied 266 newly diagnosed LCH patients to understand the clinical presentation, treatment, and prognosis of ...adult LCH. The median age at diagnosis was 32 years (range, 18–79 years). At the time of diagnosis, 40 patients had single lesions within a single system, 18 patients had single pulmonary LCH, 26 patients had multiple lesions within a single system (SS‐m), and 182 patients had multisystem disease (MS). The most common organ involved in MS patients was the bone (69.8%), followed by the pituitary (61.5%) and lung (61.0%). BRAFV600E, BRAF deletion, and MAP2K1 mutation were detected in 38.8%, 25.4%, and 19.4% patients, respectively. BRAF deletion was found more common in patients with MS LCH compared to single‐system LCH (38.5% vs 7.1%, p = .004), also in patients with liver involvement (69.2% vs 14.3%, p < .001). The estimated 3‐year overall survival (OS) and event‐free survival (EFS) rates were 94.4% and 54.7%, respectively, in SS‐m and MS LCH. Multivariate Cox regression showed that involvement of the liver or spleen at baseline predicted poor EFS and receiving cytarabine‐based therapy as a first‐line treatment and age older than 30 years at diagnosis predicted favorable EFS. The involvement of risk organs and age older than 50 years predicted poor OS, and receiving cytarabine‐based therapy predicted favorable OS. Therefore, BRAF deletion was correlated with MS LCH, particularly those with liver involvement. Liver or spleen involvement at baseline indicates a poor prognosis, and a cytarabine‐based regimen could be considered as first‐line treatment for adult LCH patients.
•Nearly translation-invariant wavelet frames are constructed with centralized multiresolution analyzing ability.•2D vibration images are constructed form 1D spindle vibration measurements via ...multiscale decomposition.•Convolutional neural network (CNN) is utilized to implement deep learning from 2D vibration images.•Tool wear states are effectively identified with combination of derived wavelet frames and CNN.
On-machine monitoring of tool wear in machining processes has found its importance to reduce equipment downtime and reduce tooling costs. As the tool wears out gradually, the contact state of the cutting edge and the workpiece changes, which has a significant influence on the vibration state of the spindle. The performance of traditional intelligent fault diagnosis methods depend on feature extraction of dynamic signals, which requires expert knowledge and human labor. Recently, deep learning algorithms have been applied widely in machine health monitoring. In this paper, we present a novel intelligent technique for tool wear state recognition using machine spindle vibration signals. The proposed technique combines derived wavelet frames (DWFs) and convolutional neural network (CNN). Constructed based on dual tree wavelets, DWF are equipped with merits of centralized multiresolution and nearly translation-invariance. In this method, DWFs are employed to decompose the original signal into frequency bands of different bandwidths and different center frequencies, which are more pronounced as the tool wears. Further, the reconstructed sub-signals are stacked into a 2-D signal matrix to match the structure of 2-D CNN while retaining more dynamic information. The 2-D convolutional neural network is utilized to automatically recognize features from the multiscale 2-D signal matrix. End-milling experiments were performed on a S45C steel workpiece at different machining parameters. The experiment results of the recognition for tool wear state show the feasibility and effectiveness of the proposed method.
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