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This paper presents a regulating Hybrid Switched Capacitor Converter (HSCC) topology suitable for high conversion ratio Point-of-Load (PoL) applications, specifically targeting 48 V to 1 V power delivery in space-based high-performance computing systems, where size and weight are important considerations, along with device de-rating for radiation tolerance. The proposed topology merges an initial 2:1 switched capacitor conversion stage with a recently developed symmetric dual inductor hybrid (SDIH) conversion stage, reaping benefits of both. The SDIH stage offers reduced component count and an excellent switch stress figure of merit, while the initial 2:1 voltage reduction stage significantly reduces the volume of flying capacitors, enabling compact size and low weight. A high density gate drive solution is also presented, using a minimal number of driver ICs without compromising on driving capability. A preliminary hardware prototype demonstrates this topology's feasibility while employing de-rated gallium nitride (GaN) switches to safeguard against radiation total ionizing dose (TID) and single event effects (SEE). This prototype achieves a very high measured power density of 2,020 W/inch3 (123.3 kW/liter) while performing 48 V to 1 V conversion and switching at 1 MHz.

Resident training is a necessary path to cultivate excellent clinical doctors. Based on the Consensus on Core Competency Framework for Residency Education Among China Consortium of Elite Teaching Hospitals for Residency Education, Department of Neurology from Peking Union Medical College Hospital has established a training program for neurology residents with a graded evaluation system and a progressive clinical responsibility concept guided by core competency. Overcoming the teaching difficulties of neurology and considering the clinical characteristics of neurology, we have established a series of replicable and promotable neurology residency training curriculum through inheritance and innovation, which provides reference for the continuous improvement of China's neurology residency training program.

By operating resonant switched-capacitor converters at resonance, zero current switching (ZCS) can be achieved to eliminate voltage-current overlap losses. Previous literature has shown that zero voltage switching (ZVS) can also be achieved to further reduce switching losses and attain a higher peak efficiency by recovering the charge stored in the parasitic output capacitance of the switches. Contrary to ZCS operation, ZVS timing is highly dependent on load current even with ideal primary passive components. This paper proposes a novel digital control technique that can dynamically track the optimum ZVS timing across a wide range of load current, through passive component and voltage variations. The proposed concept is validated in a 48-V-to-24-V resonant switched-capacitor (ReSC) converter prototype, demonstrating over 10% power loss reduction compared with the conventional open-loop ZVS, and approximately 30% power loss reduction compared with ZCS.

The series-capacitor buck (SCB) converter is a compact and highly-efficient alternative to the multi-phase buck converter and has recently been demonstrated in data center applications. To achieve high power density, it is desirable to reduce the total flying capacitance in this topology. However, for sufficiently small flying capacitances, a discontinuous capacitor voltage mode (DCVM) manifests, leading to an imbalance in inductor currents. This work provides a detailed derivation of the relationship between the critical capacitance describing the onset of DCVM and converter operating parameters. Moreover, the inductor current imbalance is characterized through the development of a clamped steady-state model. To recover balancing when flying capacitance below the critical value is used, a technique to drive the branches with modified duty cycles in a constant power regime is proposed. Experimental validation of the steady-state model and recovery of inductor current balancing are demonstrated on a 4-branch SCB prototype.

目的 在神经科住院医师中开展困难谈话技能培训课程，探究困难谈话技能培训的可行性，并初步探索本课程的效果。 方法 在北京协和医院神经科住院医师中开展2次困难谈话技能培训课程，每月1次，每次2 h。课程主题均为与神经科临床实践相关的具体临床情景，包括：①告知坏消息；②与“困难”患者或家属沟通；③讨论不施行心肺复苏等抢救措施；④与家属讨论重症患者的临终关怀。采用情景模拟教学方法，邀请标准化病人和住院医师在教师指导下完成案例情景模拟，并进行医患沟通伦理知识、技能策略的学习。采用匿名在线调查评估住院医师对本课程的满意度，课程前后采用困难谈话技能自我评估问卷分析住院医师11个维度技能的改善情况。课程结束1年后使用医患沟通技能评价量表（set the stage，elicit information，give information，understand the patient’s perspective，and end the encounter；SEGUE）对部分住院医师的沟通能力进行考核。 结果 共有14位住院医师参加了困难谈话技能培训课程，12位（85.7%）完成了相关调查评估问卷。完成问卷的住院医师中9位（75.0%）为女性，10位（83.3%）为低年级住院医师（第一年或第二年住院医师）。总体而言，住院医师对本课程反响积极，所有完成问卷的住院医师均对课程表示满意；参与的住院医师在困难谈话技能自我评估问卷涉及的绝大多数维度上均有不同程度改善；4位住院医师完成SEGUE评估，3位获得A级评分。 结论 在神经科住院医师中使用基于真实病例的特定临床情景模拟来开展困难谈话技能培训课程是可行的，住院医师对课程满意度高且课程对其有积极影响，住院医师的困难谈话技能在培训后得到一定提升。 Abstract: Objective A preliminary training course on difficult conversation skills was developed for neurology residents to explore the feasibility and effects of difficult conversation skills training. Methods Two difficult conversation skills training courses focusing on specific clinical scenarios of particular relevance to neurologic practice were conducted among the neurology residents in Peking Union Medical College Hospital, once a month for 2 hours each time. The topics were: giving bad news, communicating with “difficult” patients or family members, discussing not implementing cardiopulmonary resuscitation and other rescue measures, and discussing the hospice care of patients in severe or critical condition with their families. Standardized patients and residents were invited to complete simulation-based teaching and the learning of doctor-patient communication ethics knowledge, skill, and strategies under the guidance of teachers. An anonymous online survey was used to assess residents’ satisfaction with the course. The self-assessment questionnaire of difficult conversation skills was used to analyze the improvement of residents’ skills in 11 dimensions before and after the course. Set the stage, elicit information, give information, understand the patient’s perspective, and end the encounter (SEGUE) was used to assess the communication ability of partial residents after one year of the course. Results A total of 14 residents participated in the course, and 12 (85.7%) completed the questionnaire, of which 9 (75.0%) were female, and 10 (83.3%) were junior residents, including first- and second-year residents. Overall, the residents reacted positively to the training course and gained improvements in most aspects addressed in the questionnaire to different extents. All residents who completed the questionnaire were satisfied with the course, and 3 of the 4 residents who completed the SEGUE evaluation got a grade of A. Conclusions Difficult conversation skills training using specific clinical scenarios stimulation based on real neurologic cases was well accepted by neurology residents. The residents had a high degree of satisfaction with the course and the course had a positive influence on the participants. Their ability of difficult conversations has been improved to different degrees after the training.

The Ehlers-Danlos syndrome(EDS)is a rare inherent connective tissue disorder. The prevalence of EDS in the population is estimated at one out of ten thousand to one out of a hundred thousand. The vascular EDS(vEDS) are rare among the subtypes but are the worst in prognosis. The article reports a case of vEDS admitted to the hospital. The patient was a young man complaining of a sudden onset of aphasia in right hemiparalysis and severe left abdominal pain for unknown reasons. The diagnosis was made after the genetic testing. The patient suffered from vEDS. Then, the multi-disciplinary team(MDT)made a treatment plan tailored to this young patient. The complexity in classification and delusive presentations of the EDS make the correct diagnosis very challenging. This article hopes to report this case and to share the experiences to the better understanding of this disease.

As a result of their soft-charging and soft-switching capabilities, resonant switched-capacitor (ReSC) converters can achieve higher efficiencies and power densities than pure switched-capacitor (SC) converters. However, the terminal capacitors (i.e, the input and output capacitors) still consume a large volume in ReSC converters and represent the new bottleneck for converter miniaturization. Theoretically, when the terminal capacitances are reduced, an optimum clocking scheme that preserves multi-resonant operation can be calculated. In practice, this optimal operating point may not be precisely obtained due to circuit parasitics, passive component tolerance and derating. This paper demonstrates a closed-loop hysteretic control method that can dynamically track the zero current switching (ZCS) operating point and allow for a reduction in terminal filtering capacitors via multi-resonant operation. A 48-to-24-V ReSC converter prototype is designed and constructed to verify the effectiveness of the proposed control method. The controller is demonstrated to successfully track the ZCS operating point, enabling over 70% reduction in terminal capacitor volume. In the case of reduced terminal capacitances, the controller achieves up to 44% reduction in power loss compared with the conventional open-loop control without ZCS autotuning.

This paper proposes an efficient and compact hybrid switched-capacitor (SC) converter for direct 48-to-1-V power conversion in data centers. The proposed topology can be viewed as a 2-to-1 SC converter merged with two 8-to-1 series-capacitor-buck (SCB) modules through two switching buses. Different from the conventional DC bus architecture, the switching bus architecture removes the bulky DC bus capacitors and reduces the number of switches. Compared with existing 48-to-1-V hybrid SC demonstrations, the proposed converter achieves the highest SC stage conversion ratio with the lowest normalized switch volt-ampere (VA) rating, which promises lightened conversion burden on the following buck stage and reduced switch stress. A hardware prototype is designed, constructed and tested up to 500-A output current, achieving 94.7% peak power stage efficiency, 86.4% full-load efficiency and 464-W/in3 power density.

Cerebral small vessel disease is a leading cause of stroke and a major contributor to cognitive decline and dementia, but our understanding of specific genes underlying the cause of sporadic cerebral small vessel disease is limited. We report a genome-wide association study and a whole-exome association study on a composite extreme phenotype of cerebral small vessel disease derived from its most common MRI features: white matter hyperintensities and lacunes. Seventeen population-based cohorts of older persons with MRI measurements and genome-wide genotyping (n = 41 326), whole-exome sequencing (n = 15 965), or exome chip (n = 5249) data contributed 13 776 and 7079 extreme small vessel disease samples for the genome-wide association study and whole-exome association study, respectively. The genome-wide association study identified significant association of common variants in 11 loci with extreme small vessel disease, of which the chr12q24.11 locus was not previously reported to be associated with any MRI marker of cerebral small vessel disease. The whole-exome association study identified significant associations of extreme small vessel disease with common variants in the 5' UTR region of EFEMP1 (chr2p16.1) and one probably damaging common missense variant in TRIM47 (chr17q25.1). Mendelian randomization supports the causal association of extensive small vessel disease severity with increased risk of stroke and Alzheimer's disease. Combined evidence from summary-based Mendelian randomization studies and profiling of human loss-of-function allele carriers showed an inverse relation between TRIM47 expression in the brain and blood vessels and extensive small vessel disease severity. We observed significant enrichment of Trim47 in isolated brain vessel preparations compared to total brain fraction in mice, in line with the literature showing Trim47 enrichment in brain endothelial cells at single cell level. Functional evaluation of TRIM47 by small interfering RNAs-mediated knockdown in human brain endothelial cells showed increased endothelial permeability, an important hallmark of cerebral small vessel disease pathology. Overall, our comprehensive gene-mapping study and preliminary functional evaluation suggests a putative role of TRIM47 in the pathophysiology of cerebral small vessel disease, making it an important candidate for extensive in vivo explorations and future translational work.

More energy-efficient and power-dense solutions to 48 V to point-of-load (PoL) power conversion are required for modern and future data center power delivery. This paper proposes a Dickson-squared hybrid switched-capacitor (SC) con-verter for direct 48 V-to-PoL conversion with high efficiency and high power density. The proposed topology comprises a 9-to-1 SC stage that can be viewed as two 3-to-1 Dickson SC converters combined together and a nine-phase interleaved buck stage. The proposed topology can achieve complete soft-charging operation with a simple control, ensure naturally balanced interleaved inductor currents, enable reduced conversion burden on the buck stage, and eliminate the need for large bus capacitors with a switching bus architecture. A 48 V-to-PoL hardware prototype is built to verify the performance of the proposed converter, achieving 93.8% peak efficiency and 360 W/in3power density at 1.0 V output voltage.

In resonant switched-capacitor (ReSC) converters with the conventional two-phase control, input and output capacitors (Cin and Cout) need to be sufficiently large to ensure ideal input and output behaviors. However, the bulky terminal capacitors dramatically increase the overall converter volume and significantly limit the potential of ReSC converters for achieving higher power density. This paper proposes a multi-resonant compensation control (MRCC) technique for ReSC converters that can adaptively compensate for the negative effects of finite terminal capacitances by ensuring multi-resonant and full zero current switching (ZCS) operation with adjusted duty ratio and switching frequency. The proposed technique is verified experimentally in a 2-to-1 ReSC converter prototype, demonstrating a more than 5 times terminal capacitance reduction without harming the overall efficiency compared to the conventional control technique.

In pre-existing modeling and analysis of resonant switched-capacitor (ReSC) converters, input and output capacitances (Cin and Cout) have long been assumed to be sufficiently large to ensure ideal input and output behaviors. However, this paper reveals that, in practical applications, finite terminal ca-pacitances can have considerable effects on the output impedance and efficiency of ReSC converters. This paper proposes a general modeling and analysis methodology that can characterize the effects of finite terminal capacitances on the output impedance of ReSC converters. The proposed model is verified by circuit simulations and experimental measurements from a 2-to-1 ReSC converter prototype. It is revealed that the insufficiency in terminal capacitances can result in higher critical switching frequency, and Cin has stronger influence on the critical switching frequency than Cout.

The rapid growth in data-center electricity consumption has created an imperative need for more energy-efficient solutions to data center power delivery. This work proposes a multi-phase hybrid switched-capacitor (SC) converter for direct 48 V to point-of-load (PoL) conversion with high performance. The proposed topology can be viewed as a 6to-1 cascaded series-parallel (CaSP) converter merged with a three-phase interleaved buck converter with automatic current balancing. Due to multi-phase operation, the CaSP stage is able to achieve a higher conversion ratio compared to twophase SC converters with the same number of components as well as lower turn-on voltage for switching devices. Moreover, the proposed CaSP-PoL topology benefits from the frequency multiplication effect similar to that in flying capacitor multilevel converters, which allows for lower frequency operation of higher voltage rated switches and doubled frequency operation of buck inductors, contributing to a further reduction in switching loss and inductor size. A 48 V-to-PoL hardware prototype was built in vertical assembly structure for compact packaging and tested up to 90 A output current, achieving 94.1% peak efficiency (93.2% including gate drive loss) and 702 W/in 3 power density (by box volume) at 2.0 V output voltage.

Objective To summarize the clinical characteristics and RNF216 gene mutation of a patient with Gordon Holmes syndrome (GHS), and to improve the understanding of the genetic and clinica characteristics of this disease through literature review. Methods We collected the clinical data of the patient with GHS, extracted the DNA from 2 mL peripheral venous blood of the patient and his parents for whole exome gene detection, and then we analyzed the clinical and genetic characteristics of all previously reported patients with RNF216 gene mutation. Results The young male patient was short in stature at sixyearsold and was diagnosed growth hormone deficiency.He had no secondary sexual characteristics by the age of 15 and was diagnosed hypogonadal hypogonadism.After the age of 22, he gradually developed abnormal gait and had progressive decline in speech, motor, and cognitive functions.Whole exome sequencing revealed a homozygous, nonsense mutation c.1549C>T (p.R517*) in the RNF216 gene.His parents were consanguineous and were heterozygous carriers of the mutations with phenotypic normality.Combined with literature review and this case report results showed that a total of 21 patients of the disease in the world and among them 15 had pathogenic variants of RNF216 gene mutation.7 of the 15 had truncated mutations, 5 had missense mutations, and 1 synonym mutation, 1 splice mutation, and 1 deletion mutation respectively.RNF216 gene mutation can be seen in neurodegenerative diseases with multiple overlapping symptoms of GHS, Huntington-like disease, and 4H syndrome.The main clinical manifestations are hypogonadotropic hypogonadism and early-onset progressive neurological dysfunction in adolescence or early adulthood.The median age of onset of neurological symptoms is 28 years old, featuring cerebellar ataxia, dysarthria, and cognitive impairment, as well as imaging manifestations of extensive white matter lesions and cerebellar atrophy. Conclusions The mutation of RNF216 gene can cause GHS.Genetic testing is helpful to the diagnosis and treatment of rare diseases.

In pre-existing analytical models of switched-capacitor (SC) converters, input and output capacitances (Cin and Cout) have long been neglected based on the assumption of input and output as ideal voltage sources. However, this paper reveals that, in practical applications, the terminal capacitances are usually not sufficiently large to ensure ideal input and output behavior and can have considerable effects on output impedance Rout and overall efficiency. To quantitatively investigate their effects, this paper proposes a general modeling and analysis methodology for SC converters that is capable of considering the effects of finite Cin and Cout. The proposed model is verified by experimental measurements from a 2-to-1 SC converter prototype with less than 8% relative error. It is revealed that the insufficiency of Cin can lead to a considerable increase in Rout and thus harms overall efficiency. On the contrary, smaller Cout can help reduce Rout, although this benefit comes at the cost of larger output voltage ripple. In addition, Cout has stronger effects on Rout in the slow switching region, while Cin is more influential at higher switching frequency, especially around the knee of the Rout curve at which the converter usually operates. Several design guidelines are provided based on these findings.