Sufficient Margin Research Articles

Classification of the Volume of Tumor Lesion of the Chest Wall as A Prerequisite for Planning Surgical Treatment

Tumors of the chest wall are a heterogenous group of neoplasms per nosology, clinical progression, and treatment methods. Primary tumors of this location, according to some authors, comprise between 1 and 5 %, and 60 % of them are malignant. Tumors of the chest wall can have not only various nosological forms but also varying volume, location, affect different structures of the chest wall which are determined during physical exam. Despite the progress in drug therapy, radical surgical intervention is a prerequisite for successful treatment of patients with malignant tumors of the chest wall. One of the most important prognostic factors is sufficient margin during chest wall resection. The international tumor classification system Tumor, Nodus and Metastasis (TNM) does not give a complete understanding of the volume of lesions and therefore does not allow to correctly plan resection volume and defect reconstruction based on its data.The article presents a classification of tumor volume of the chest wall proposed by the Sarcoma Research Association which allows to expand indications for surgical treatment and select the optimal type of defect reconstruction.

Performance-based seismic design of sliding gusset plate braced frames incorporating thermodynamic models

A sliding gusset plate braced frame (SGBF) is proposed to enhance the seismic resilience of steel concentrically braced frames (CBFs). The symmetric friction connection (SFC) is used at the brace-to-gusset plate connection to create a sliding gusset plate brace. The sliding gusset plate brace offers high initial stiffness to withstand wind and service level earthquake loads. It also absorbs energy through friction beyond service level earthquakes, which mitigates performance degradation caused by brace buckling. Besides, replaceable links are added to the beam ends where plastic hinges are anticipated to form, creating a dual system that allows for damage control and rapid repair. The paper first presents the design concepts and performance objectives of SGBFs. Subsequently, a thermodynamic model is established to reveal the energy–temperature–coefficient of friction (CoF) (E-T-μ) relationship based on quasi-static tests of SFCs. The model partially tackles and addresses the challenge of temperature-dependent variations in CoF during sliding. By incorporating the model into performance-based seismic design, the overstrength ratio of SFC due to temperature-induced hardening can be quantified, according to the energy absorption demand of a specific SGBF during an earthquake. In this manner, unexpected damage and failure of members adjacent to the SFC and sliding gusset plate braces can be avoided. To demonstrate the application of the thermodynamic model and verify the seismic performance of SGBF, a prototype is designed based on a practical four-story hospital and validated through an excessive array of nonlinear dynamic analyses. The results show that the proposed SGBF can achieve the targeted performance objectives under different seismic shaking intensities. In addition, the SGBF has a sufficient margin of safety against collapse. Hence, the proposed SGBF can be used as an efficient and resilient structural system in high seismic zones.

New limits proposed for the management of non-mutagenic impurities

Multiple international guidelines exist that describe both quality and safety considerations for the control of the broad spectrum of impurities inherent to drug substance and product manufacturing processes. However, regarding non-mutagenic impurities (NMI) the most relevant ICH Q3A/B guidelines are not applicable during early phases of drug development leading to confusion about acceptable limits at this stage. Thus, there is need for more flexible approaches that ensure that patient safety remains paramount, while taking into consideration the limited duration of exposure. An EFPIA survey, which collected quantitative data from different types of studies applied to qualify impurities in accordance with ICH Q3A, shows that no toxicities could be attributed to any of the 467 impurities at any tested level in vivo. This data combined with earlier published toxicological datasets encompassing drug substances and intermediates, food related substances and chemicals provide convincing evidence that for NMIs, the application of a generic 5 mg/day limit for an exposure duration <6 months, and a 1 mg/day generic limit for life-long exposure, provides sufficient margins to ensure patient safety. Hence, application of these absolute limits to trigger qualification studies (instead of the relative limits described in Q3A/B), is considered warranted. This approach will prevent conduct of unnecessary dedicated impurity qualification studies and the resulting use of animals.

A New Integration Scheme to Prevent Chemical Attack on Floating Polysilicon Gate of Non-Volatile Memory

—Silicon pitting has been observed on floating gate polysilicon layer of embedded non-volatile memory(e-NVM) process due to chemical attack caused by HBr residual interacting with moisture. This paper successfully demonstrates a new integration scheme for a robust floating gate process against silicon attack for embedded stacked/split gate non-volatile memory process. Firstly, CF4 was introduced into floating gate polysilicon etch recipe to replace HBr, which has been CMOS gate polysilicon etch gas in traditional logic process due to the advantage of higher selectivity despite the disadvantage of low vaporability, for better or cleaner process control. Secondly, an additional plasma removal stripping (PRS) clean step was added before chemical removal stripping (CRS) to give better etch by-product cleaning, even though there is no photoresist and lithography involved on the poly blanket etch for the better etch by-product cleaning. This new scheme has been verified using inline optical inspection defect-scan to prove the sufficient process margin for better mass production control that came from improved manufacturing Queue-time margin (longer waiting time) between dry-etch step, CRS step, and subsequent downstream process steps.

Abstract PO2-23-01: Selective cavity margin shaving: effective method to maintain balance between cosmesis and negative margin in breast conserving surgery

Abstract Background: Breast conserving surgery (BCS), which became the mainstay of breast cancer surgery, both cosmesis and margin negativity are significant issues. Firstly, it is well known that negative resection margin is crucial for reducing local recurrence after BCS. Therefore, there has been numerous attempts to secure negative margin, such as specimen mammography, frozen section margin analysis, and cavity margin shaving. Regarding cosmesis, wider excision to secure negative margin could disrupt cosmesis especially in Asian patients with relatively smaller breast, and minimizing excision volume is necessary for optimal cosmetic outcome. Our center adopted the concept of selective cavity margin shaving (SCMS) to achieve negative margin while optimizing cosmetic result. Method: 606 female patients with non-metastatic, unilateral breast cancer were prospectively collected and underwent BCS with SCMS from October, 2012 to December, 2020. The medical record was retrospectively reviewed, and we assessed positive margin rate and local recurrence. During BCS, the surgeon excised gross margin of 1~2cm around the cancer, and assessed the proximity of the margin through gross examination. If sufficient margin was not obtained, cavity shaving was performed in the close margin, while shaving from retrieved specimen was conducted on the sufficient margin side. Additionally, circumferential margin frozen analysis was carried out, and further excision was performed until a negative margin was achieved or when only focal DCIS involvement remained. Result: The mean ± SD age of the patients was 52.47 ± 9.92 years and mean follow-up period was 59.98 ± 26.59 months. 56 patients (9.24%) received neoadjuvant chemotherapy. 123 patients (20.29%) got positive margin for invasive cancer or DCIS in frozen section margin analysis and 97 patients (16.01%) underwent intraoperative re-excision. There was discordance between frozen and permanent section margin analysis in 48 patients (7.92%), and 7 patients (1.16%) underwent post-operative re-excision operation. Local recurrence occurred in 11 patients (1.82%), which is significantly lower compared to previously reported outcomes after BCS. Presence of lympho-vascular invasion, neoadjuvant chemotherapy, and margin involvement of invasive cancer in permanent section analysis were strongly related with local recurrence. Conclusion: In conclusion, SCMS and frozen section margin analysis demonstrated low positive margin rate and reduced re-excision rate. The local recurrence was also lower compared to conventionally reported rate after BCS. Selective cavity margin shaving is an oncologically safer and effective surgical method with minimized cosmetic deformity. Table 1. Baseline patient characteristics Table2. Univariate and multivariate analysis of factors associated with local recurrence Table2. Univariate and multivariate analysis of factors associated with local recurrence by Cox proportional hazard model. Citation Format: Dabin Kim, Zisun Kim, Sung Mo Hur, Cheol wan Lim. Selective cavity margin shaving: effective method to maintain balance between cosmesis and negative margin in breast conserving surgery [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-23-01.

Recent advancements with the H− injector performance for the Spallation Neutron Source operation and upgrade

The Spallation Neutron Source (SNS) located at the Oak Ridge National Laboratory is an accelerator-based, pulsed neutron facility utilized for a broad range of scientific research and industrial applications. In the past 5 years, the facility has reliably been operated at its baseline design beam power of 1.4 MW, and it is currently undertaking an upgrade to double its power to 2.8 MW. A 65-keV H− injector, which comprises an rf-driven H− ion source and an electrostatic low energy beam transport, delivers the required high-current, time-structured H− beam to the accelerator. The H− injector can reliably provide 50-60 mA beam current at 6% duty-factor (1 ms, 60 Hz) for a 3-4 month service cycle. To ensure sufficient operational margins for the SNS routine operations and ongoing upgrade requirements, the injector system has been continuously improved on a R&D test stand. This paper presents the operational status and recent advancements with the injector system performance including the enhanced ion source beam output capability up to ∼110 mA, the improved ion source plasma ignition reliability using a 27.12-MHz RF system, and the upgraded LEBT beam chopper system etc.

Suspension parameter optimization for high-speed train with severe tread wear

ABSTRACT The suspension parameters are optimized to improve the dynamic performance of high-speed train with severe tread wear and suppress the formation of severe tread wear. Except for the common indicator of high-conicity stability (A high ) for the vehicle dynamic performance with severe tread wear, a hollow wear index (HWI) is proposed to reduce the development rate of wheel hollow wear. Moreover, the low-conicity ride comfort (W low ) is considered for the dynamics performance with new tread. Yaw stiffness (YS) and the ratio of yaw damping to lateral damping (RYL) are proposed to characterize the suspension parameters matching. Results show that HWI is strongly positively correlated with W low , and is negatively correlated with A high . Increasing the RYL can enhance W low , and the YS should be reduced to improve HWI under the condition of sufficient hunting stability margin. Hunting bifurcation analysis elucidates that the model with better HWI is easy to form supercritical bifurcation.

Grid voltage sensorless control of a single‐phase shunt hybrid active power filter

AbstractHere, a grid voltage sensorless control of an LCL‐filtered LC‐tuned single‐phase shunt hybrid active power filter (HAPF) is proposed, which offers high‐quality harmonic current compensation with low hardware requirements. An estimation algorithm replaces the grid voltage sensor and associated circuitry to reduce the size and cost. This paper presents a straightforward and accurate modelling of the suggested structure and its filtering characteristics, followed by a comprehensive yet simple parameter design procedure. An inherent damping technique that uses digital delay rather than virtual or physical damping resistors eliminates the need for additional sensors or extra power losses. As part of the design, a high‐quality reference current is generated for the filter, which is then effectively tracked using a proportional controller with sufficient bandwidth and stability margin. An experimental prototype is implemented to verify the theoretical results, and several steady‐state and transient waveforms are reported to demonstrate the superior performance of the HAPF.

Magnetization switching and performance of an optimized bicomponent multiferroic nanomagnet

Achieving complete magnetization switching is a significant challenge in the electrical control of magnetic devices. In this paper, we propose a structure called bicomponent multiferroic nanomagnet (BMN) to study strain-mediated magnetization switching behavior. The BMN consists of a complete piezoelectric layer and a magnetostrictive layer made of bicomponent magnetic materials. Our team successfully developed a dynamic model for the magnetization of BMNs. By micromagnetic simulation, the results show that the strict requirements for a precise applied voltage period can be overcome in such a BMN, and a 180° magnetization switching can be achieved with only a square-wave voltage signal and a pulse width (tth) larger than 0.5 ns, given that the amplitude of the voltage is 60 mV. In addition, we also investigated the tolerance window of material composition and geometry, and proved that BMNs have sufficient error margins and the switching rate of BMNs can reach 1.67 GHz within the error margins at room temperature. Our proposed BMN device has a simple structure and low energy consumption as it does not require precise piezoelectric layer design or stringent voltage clocking requirements. The energy consumption per switching is only 7.3 aJ. These findings provide significant guidance for the design of nanomagnetic logic and memory devices and lay a strong foundation for the application of strain-mediated magnetization switching technology.

Simulation of damage under cyclic loading for API 5L X70 steel pipelines (fatigue test)

The most efficient way to move large volumes of gas and oil is through pipelines, either from points of production to storage locations or from storage locations to distributed points of end use. One of the main materials of gas transportation pipes is X70 material. Base on the importance of in-service API 5L X70 pipelines, it is important for the safe operation of this system to know the lifespan of pipelines, and predict fatigue crack growth (FCG) of API 5L X70 steel pipeline. The objective of this theme is to study the lifespan of pipelines used for the transport of natural gas, oil and water, manufactured by the company ALFAPIPE in the wilaya of Ghardaïa. The judicious choice for manufacturing metal is a crucial factor to ensure prolonged life duration and improve resistance to fatigue, as materials respond to loading with elastic or plastic deformation. Stresses applied to materials can result in permanent deformation, rupture, cracking or progressive degradation. Understanding the effects of applied stresses is essential for the selection and implementation of materials in industrial applications. Fatigue tests were carried out on API 5L X70 steel using simulations using ANSYS software. The life of different samples was determined for different thicknesses after applying repeated stresses. The obtained results demonstrate the material API 5L X70's sensitivity to fatigue and emphasize the significance of designing pipelines with sufficient safety margins to prevent premature failures caused by fatigue.

Analysis of super‐source‐follower‐based GHz‐bandwidth biquadratic low‐pass filters

SummaryThe design of GHz‐bandwidth super‐source‐follower‐based low‐pass filters (SSF‐LPFs) is investigated. The transfer function is derived by considering transistor parasitics. The behaviors of SSF‐LPFs can be predicted accurately with these formulas. The theoretical values of pole/zero frequencies of the circuit agree well with the corresponding simulation results. Moreover, the relationship between the Q factor and the phase margin of the biquadratic filter is revealed. Two 1.3‐GHz 4th‐order LPFs are designed using 90‐nm CMOS technology, where one contains a high‐Q biquad with a small phase margin and a low‐Q biquad, while the other is built with two biquads with moderate Q factors and sufficient phase margins. For the former, the discrepancy between the theoretical and simulated phase margin is &lt;2°, and the discrepancy between the theoretical and simulated corner frequency is &lt;6%. For the latter, the discrepancy between the theoretical and simulated phase margin is &lt;4°, and the discrepancy between the theoretical and simulated corner frequency is &lt;4%. The filter containing biquads with sufficient phase margins is fabricated and occupies an area of 0.44 mm2. Consuming 14.4 mW, the filter delivers a bandwidth of 1.3 GHz, P1dB of −11.94 dBm, and IIP3 of −4.5 dBm.

Conceptual design and feasibility analysis of a heat pipe cooled cermet fuel space nuclear reactor for mars surface application

The compact, safe, light-weight and highly reliable Space Nuclear Reactor (SNR) with heat pipe cooling is an excellent candidate for the potential needs of Mars surface applications. This work proposed a heat pipe reactor concept design which can provide 1 MWth power for more than 8 years. Reactivity control is accomplished by 6 rotating control drums. Cermet fuel with dispersion granules characteristics adopted in this design is processed into prismatic-type tube-in-duct (TID) and composed of Mo-14 wt%Re matrix and highly enriched uranium nitride (UN) granules. Both heterogeneous and homogeneous models of Cermet fuel are evaluated by OpenMC code, indicating an extreme weak resonance self-shielding effect. Neutronics characteristics such as the effective multiplication factor, burnup depth, fuel temperature coefficient, neutron spectrum, reactivity control, neutron flux and power distribution are obtained. Drum stuck accidents and submersion criticality accidents are also analyzed. The designed reactor achieves a shutdown depth of −1521 pcm in the worst launch or reentry accident scenario considered without relying on the reactivity control device. The arrangement forms and content of Spectral Shift Absorber (SSAs) that affect the safety worth are also analyzed. Furthermore, thermal analysis is performed by Fluent and the maximum temperature is lower than 1570K during normal operation. The maximum temperature reaches 1805K and core has sufficient margin to respond to a single point failure of the heat pipe. Overall, the scheme preliminarily satisfies neutronics, thermal and safety requirements.

PERAN LEMBAGA KEUANGAN SYARIAH DAN DAYA TARIK MASYARAKAT TERKHUSUS PADA SEKTOR UMKM

The Islamic Financial Sector (IFS) is a rapidly growing sector in the Islamic economy. IFS operates on Islamic law, so it must always adhere to Islam. IFS plays a crucial role in implementing Islamic principles aimed at helping society achieve prosperity, honesty, and fairness through a profit-sharing system. One of the key players in the Islamic financial sector is Islamic banking, which has a low credit risk, resulting in a sufficient margin for MSMEs. MSMEs, also known as Usaha Mikro Kecil dan Menengah (UMKM), are a type of productive business owned by individuals or corporations and regulated by Law No. 28 of 2008. UMKM has a significant role in Indonesia's economy. This potential is what motivates Islamic banks to facilitate the provision of loans to MSMEs. As time passes, Islamic banks have become capable of supporting MSMEs, which in turn attract MSMEs to conduct transactions at Islamic banks.

Comparison of endoscopic resection therapies for rectal neuroendocrine tumors

Aims This study was to evaluate and compare the efficacy and safety of endoscopic mucosal resection (EMR), clip-and-snare assisted endoscopic mucosal resection (CS-EMR), and endoscopic submucosal dissection (ESD) for the endoscopic resection of rectal NETs. Material and methods A retrospective analysis was performed on 47 patients with rectal NETs who underwent endoscopic treatment in The Second Affiliated Hospital of Soochow University. Manifestations of clinic pathological characteristics, complications, procedure time and hospitalization costs were studied. Results The complete resection rates with CS-EMR and ESD were significantly higher than those with EMR (CS-EMR vs. EMR, p = 0.038; ESD vs. EMR, p = 0.04), but no significant difference was found between the CS-EMR and ESD groups (p = 0.383). The lateral margin was less distant in the CS-EMR group than in the ESD group and there was no difference with regard to vertical margin (lateral margin distance, 1500 ± 3125 vs.3000 ± 3000 μm; vertical margin distance, 400 ± 275 vs.500 ± 500 μm). Compared to ESD, CS-EMR required less operation time (p < 0.01) and money (p < 0.01) and reduced the length of hospital stays (p < 0.01). Conclusions The CS-EMR technique is more effective and efficient than EMR for small rectal NETs. In addition, CS-EMR reduces procedure time, duration of post-procedure hospitalization and decreases patients’ cost compared to ESD while ensuring sufficient vertical margin distances.

Enhanced reactor core design and safety evaluation for the final cycles of Belgian nuclear power plants

The Belgian nuclear power plants, owned and operated by Electrabel, are approaching the end of their operational lifespan, as per their initial design. Tractebel, as the Owner’s Engineer in charge of fuel management for these units, has maximized the energy use of the existing fuel assemblies, either in the core or in the storage pool, to minimize the need for introducing fresh fuel assemblies in the final cycles. Tractebel’s in-house Loading Pattern Optimizer (LPO) helped in determining the optimum core reloads incorporating sufficient safety margins. The safety evaluation of these cores showed some distinctive features compared to prior reloads containing normal batches of fresh assemblies. Therefore, complementary safety evaluations in addition to the standard cycle specific evaluation were performed and approved by the Belgian Safety Authorities. This paper introduces Tractebel’s improved core design tools and processes, outlining the approach to optimize the reactor core design and providing insights into the safety evaluation methodology employed for the final cycles while avoiding the use of fresh fuel assemblies.

An escape route planning model based on wildfire prediction information and travel rate of firefighters

Background When firefighters evacuate from wildfires, escape routes are crucial safety measures, providing pre-defined pathways to a safety zone. Their key evaluation criterion is the time it takes for firefighters to travel along the planned escape routes. Aims While shorter travel times can help firefighters reach safety zones faster, this may expose them to the threat of wildfires. Therefore, the safety of the routes must be considered. Methods We introduced a new evaluation indicator called the safety index by predicting the growth trend of wildfires. We then proposed a comprehensive evaluation cost function as an escape route planning model, which includes two factors: (1) travel time; and (2) safety of the escape route. The relationship between the two factors is dynamically adjusted through real time factor. The safety window within real time factor provides ideal safety margins between firefighters and wildfires, ensuring the overall safety of escape routes. Key results Compared with other models, the escape routes planned by the final improved model not only effectively avoid wildfires, but also provide relatively short travel time and reliable safety. Conclusions This study ensures sufficient safety margins for firefighters escaping in wildfire environments. Implications The escape route model described in this study offers a broader perspective on the study of escape route planning.

The Strategy of Continuous Commutation Failure Suppression by Combining Turn-off Angle Compensation and Dynamic Nonlinear VDCOL

In recent years, with the continuous growth in China’s economy, the continuous advancement of urbanization and industrialization, the contradiction between rapid economic development and the continuous reduction in traditional fossil energy reserves such as coal, oil, and natural gas, the continuous aggravation of environmental pollution has become increasingly prominent. In this era, clean energy power generation technologies such as hydropower, wind power, and solar power generation, which have the advantages of renewability, environmental protection, and economy, have developed rapidly. However, wind and photovoltaic power plants are often located in remote areas, which means significant losses in the transmission process. High-voltage direct current (HVDC) transmission technology becomes the best choice to solve this problem. The HVDC transmission system based on a grid commutator is widely used in China’s AC-DC hybrid power grid. When an AC fault occurs on the inverter side, the line-commutated converter high-voltage direct current (LCC-HVDC) system is more prone to continuous commutation failure, which brings serious harm to system operation. To better suppress the problem of continuous commutation failure on the contravariant side, this paper analyzes the mechanism of continuous commutation failure from multiple angles. The DC current command sensitivity of a voltage-dependent current order limiter (VDCOL) in the LCC-HVDC system is low, which will lead to different degrees of continuous commutation failure. In addition, the rapid rise in DC current and the drop in commutation voltage during the fault will cause the turn-off angle to drop, and the probability of continuous commutation failure of the system will increase significantly. Based on the above theoretical analysis, a new control strategy combining the dynamic compensation of the turn-off angle of a virtual inductor and the suppression of continuous commutation failure by dynamic nonlinear VDCOL is proposed. A dynamic nonlinear VDCOL control strategy is proposed for the low sensitivity of current command adjustment under conventional VDCOL control. Secondly, two concepts of virtual inductance and DC current change rate are introduced, and a control strategy based on virtual inductance is proposed to comprehensively ensure that the switching angle has sufficient commutation margin during fault recovery. Finally, based on the CIGRE standard test model in PSCAD/EMTDC, the accuracy of the correlation mechanism analysis and the effectiveness of the suppression method are verified.

High-mobility wide bandgap amorphous gallium oxide thin-film transistors for NMOS inverters

Wide bandgap gallium oxide thin-film transistor (TFT) is promising for next-generation sustainable energy-efficient power electronics. In particular, amorphous oxide channel exhibits inherent advantages on mass productions based on a low-temperature processability compatible with cost-effective large-sized glass. Here, we developed hydrogen defect termination to produce amorphous-GaOx (a-GaOx) channel for n-channel oxide-TFT and demonstrated high-mobility a-GaOx-TFT exhibiting a high saturation mobility (μsat) of ∼31 cm2 V−1 s−1, threshold voltage (Vth) of ∼3.3 V, a current on/off ratio of ∼108, and subthreshold swing value (s-value) of ∼1.17 V·dec−1. The study found that oxygen conditions during the channel fabrication process, i.e., oxygen partial pressure during the film deposition and post-thermal annealing atmospheres, were critical for the TFT performances of gallium oxide-TFTs, and subgap defects originated from low-valence Ga+ state and excess oxygen rather than oxygen vacancy had a large responsibility for the device performances. The finding explains why the development of gallium oxide-TFTs is largely behind the other oxide-TFTs. We also fabricated depletion and enhancement-mode a-GaOx-TFTs and developed a full-swing zero-VGS-load inverter with high voltage gain ∼200 and sufficient noise margins. The present study demonstrates a high potential of gallium oxide channel for low-temperature processed n-channel oxide-TFT for next-generation electronic applications.

Parotid Gland Metastases of Cutaneous Squamous Cell Carcinoma of the Head: Occult Metastases Occurrence and Their Late Manifestation.

Cutaneous squamous cell carcinomas (cSCC) are malignant tumours with excellent prognosis unless nodal metastases develop. The aim of our study is to determine the prognostic significance of the clinical stage of parotid gland metastases and the incidence of occult cervical lymph node involvement in cSCC of the head. Our retrospective analysis includes 39 patients with cSCC parotid gland metastases, 15 of whom had concurrent cervical node involvement. In 32 patients, the lymph nodes manifested at stage N3b. A total of 26 patients were treated with parotidectomy, 9 patients received radiotherapy alone, and 4 received symptomatic therapy. The surgical treatment included either total conservative (21 cases) or superficial parotidectomy (5 cases) and neck dissection (therapeutic neck dissections in 11 cases and elective in 14 cases). In all cases, surgery was performed with sufficient tumour-free resection margins. Adjuvant radiotherapy was administered postoperatively in 16 patients. Occult metastases were present in 21% of cases after an elective neck dissection, but not in any case in the deep lobe of the parotid gland. The five-year overall survival and recurrence-free interval were 52% and 55%, respectively. Patients with the cN3b stage and G3 histological grade tend to have a worse prognosis, but not at a statistically significant level. The prognosis was not worse in patients with concurrent parotid and cervical metastases compared to those with metastases limited to the parotid gland only. The addition of adjuvant irradiation, in comparison to a single modality surgical treatment, was the only statistically significant prognostic factor that reduced the risk of death from this diagnosis (p=0.013). The extent of parotidectomy (partial vs. total) had no impact on either the risk of recurrence or patient prognosis. The combination of surgery with irradiation provides the best results and should be applied to all patients who tolerate the treatment. A partial superficial parotidectomy should be sufficient, with a minimum risk of occult metastasis in the deep lobe. Conversely, the relatively high incidence of occult neck metastases indicates that patients could likely benefit from elective neck dissection.

Fast State-of-Charge-Balancing Strategy for Distributed Energy Storage Units Interfacing with DC–DC Boost Converters

State-of-charge balance is vital for allowing multiple energy storage units (ESUs) to make the most of stored energy and ensure safe operation. Concerning scenarios wherein boost converters are used as the interfaces between ESUs and loads, this paper proposes a balancing strategy for realizing consistent state-of-charge (SoC) levels and equal currents among different ESUs. This strategy is valid for both parallel and series applications. Its advantages also include its high precision of SoC equalization without extra sensors and fast convergence. A common outer voltage loop is used to accomplish tight voltage regulation, while multiple inner current loops are utilized to achieve current control and SoC balance simultaneously. Firstly, by introducing SoC-based current distribution ratios (CDRs) to modify current references online, the currents are gradually adjusted to eliminate SoC deviations. Secondly, to expedite the balancing process, current saturations are further adopted. Thirdly, the influences of accelerating factor and current limits in CDR expressions are analyzed, and their selection guidelines are subsequently provided. Fourthly, the controller design, consisting of a dual loop, is illustrated to guarantee sufficient stability margins. Fifthly, an experimental platform consisting of three battery ESUs is developed to verify the proposed strategy.