基于开关电感电池均衡器的CCM软开关实现算法

针对开关电感的锂离子电池均衡器在小功率便携式用电设备中仍有很强的实用价值,但传统控制策略控制的均衡器中开关管为硬开关的问题,提出1种基于开关电感锂电池均衡器电流连续运行模式下的软开关实现算法。分析均衡器电感电流电池单体充、放电电流大小的决定因素,由此提出均衡器中开关管的软开关实现算法并分析了该算法的控制精度。通过检测电池单体的电压与充电电流的变化率可实时得到电池单体的等效阻抗与开路电压,进一步保证了算法的精度。实验结果表明,所提软开关控制算法性能良好。

Resection of Intracranial Giant Cavernous Malformation: Case Report and Literature Review

Cerebral cavernous malformations are a rare and congenital vascular malformation that can present as a challenge in neurosurgical management. The term “giant cerebral cavernous malformations” still does not have a clear definition in the literature, with a wide variety of results. It is known, however, that there is an association between the size of the cavernoma and postoperative sequelae, especially in those with a size greater than 3 cm in its largest diameter. We present a case report of resection of a giant brain cavernoma measuring approximately 8 cm in its largest diameter, emphasizing on clinical presentation, diagnoses and postoperative evolution. Additionally, we performed a comprehensive review of the existing literature on the subject, addressing the epidemiology, pathophysiology, diagnostic methods, treatment options, and prognosis associated with this condition.

Median Nerve Somatosensory Evoked Potentials in Patients with Chiari Malformation

Abnormal SEP reflects dysfunction of the medial lemniscus and posterior cervical cord. These structures are likely to be affected in Chiari malformation. Therefore, SEP abnormalities may provide valuable information in patients with CM. However, the consistency of SEP abnormality or normality with the damage is a matter of research. Knowing whether median nerve somatosensory evoked potential (SEP) is useful in revealing subclinical damage in patients with Chiari malformation is important in the treatment and follow-up plan of the disease. The aim of this study was to investigate the relationship between median nerve SEP values and the severity of cerebellar ectopia in patients with Chiari type 1 malformation. Median nerve SEP values were obtained from 30 healthy individuals and 146 individuals with Chiari malformation. The cerebellar ectopia degree and McRae line length were measured. SEP values were not significantly different between groups. The McRae line was found to be significantly shorter in the control group than in the Chiari malformation group (p = 0.031). There was no correlation between the degree of cerebellar ectopia and the length of the McRae line (r = 0.002, p = 0.979). Neither cerebellar ectopy degree nor McRae line length had a relationship with SEP values (r = -0.153, p = 0.066;r = -0.056, p = 0.500, respectively). There was no difference in cerebellar ectopy degree or SEP values between the groups with cerebellar ectopy with and without a syrinx (p = 0.899;p = 0.080, respectively). Likewise, McRae line length was not found to be related to the presence of a syrinx (p = 0.139). Median nerve SEP examination was not beneficial for diagnosing asymptomatic-oligosymptomatic Chiari malformation as a subclinical injury, whether accompanied by syringomyelia or not.

Cardiac Malformations in Congenital Hypothyroidism: A Case Report

Introduction: Congenital hypothyroidism is the most common causes of preventable mental retardation. It is associated with other births defects like cardiac malformations. Descriptions in Sub Saharan Africa are rare, justifying the present report. Case Report: We reported the cases of 3 female patients, diagnosed with hypothyroidism, presenting in addition pulmonary stenosis. The diagnosis was late in all the patients and we noticed clinical improvement under levothyroxine. Conclusion: Association congenital hypothyroidism and cardiac defect is not rare. Our patients are female with no history of consanguinity, presenting congenital hypothyroidism with a gland in situ associated with pulmonary stenosis. Systematic screening of other births defects is thus recommended in affected patients.

Sclerotherapy in a case of multiple glomuvenous malformation

In this study, we present a representative case of multiple glomuvenous malformation in a 12-year-old female patient. Approximately five years ago, the patient developed multiple blue-purple papules and plaques on her hypogastrium and right thigh, which progressively enlarged and presented tenderness. Histopathological examination confirmed the diagnosis of glomuvenous malformation. Following two injections of lauromacrogol, a significant improvement was observed in the lesions, including a resolution of tenderness. These findings suggest that sclerotherapy not only exhibits evident therapeutic efficacy but also effectively alleviates pain while addressing both aesthetic and therapeutic concerns.

Giant vascular malformations invading the skull:A case report

BACKGROUND Vascular malformations(VMs)arise as a result of errors in the process of angiogenesis and are usually present at birth,but may not become apparent until after birth.However,giant VMs of the head and face are uncommon,with few reported cases,and the prognosis for their surgical intervention is unclear.CASE SUMMARY A 12-year-old girl was admitted to the hospital with findings of an enlarged right temporal scalp.After admission,computed tomography(CT)angiography of cerebral ateries showed a right occlusal gap and a right temporal artery venous malformation.Furthermore,cerebral angiography showed a right temporal lobe VM with multiple vessels supplying blood.The patient underwent surgery to remove the malformed vessels and the eroded skull.Two hours after the surgery,the patient's right pupil was dilated,and an urgent CT scan of the skull showed a right subdural haematoma under the incision,which was urgently removed by a second operation.After surgery,we gave continuous antibiotic anti-infection treatment,and the patient recovered well and was discharged two weeks later.CONCLUSION Surgical removal of giant haemangiomas is risky and adequate preoperative(including interventional embolisation)and intraoperative preparations should be made.

Appendiceal bleeding caused by vascular malformation: A case report

BACKGROUND Acute lower gastrointestinal bleeding(LGIB)is a common occurrence in clinical practice.However,appendiceal bleeding is an extremely rare condition that can easily be overlooked and misdiagnosed.The preoperative detection of appen-diceal bleeding often poses challenges due to the lack of related guidelines and consensus,resulting in controversial treatment approaches.CASE SUMMARY We presented a case of a 33-year-old female who complained of hematochezia that had lasted for 1 d.Colonoscopy revealed continuous bleeding in the appen-diceal orifice.A laparoscopic appendectomy was performed immediately,and a pulsating blood vessel was observed in the mesangium of the appendix,accor-dingly,active bleeding into the appendicular lumen was considered.Pathological examination revealed numerous hyperplastic vessels in the appendiceal mucosa and dilated capillary vessels.CONCLUSION The preoperative detection of appendiceal bleeding is often challenging,colo-noscopy is extremely important,bowel preparation is not routinely recommend-ed for patients with acute LGIB or only low-dose bowel preparation is recom-mended.Laparoscopic appendectomy is the most appropriate treatment for appendiceal bleeding.

Multimodal imaging for the diagnosis of oligodendroglioma associated with arteriovenous malformation:A case report

BACKGROUND The rare co-occurrence of oligodendroglioma and arteriovenous malformation(AVM)in the same intracranial location.CASE SUMMARY In a 61-year-old man presenting with progressive headaches,is described in this case study.Preoperative multimodal imaging techniques(computed tomography,magnetic resonance imaging,magnetic resonance spectroscopy,digital subtraction angiography,and computed tomography angiography)were employed to detect hemorrhage,cystic and solid lesions,and arteriovenous shunting in the right temporal lobe.The patient underwent right temporal craniotomy for lesion removal,and postoperative pathological analysis confirmed the presence of oligodendroglioma(World Health Organization grade II,not otherwise specified)and AVM.CONCLUSION The preoperative utilization of multimodal imaging examination can help clinicians reduce the likelihood of misdiagnosis or oversight of these conditions,and provides important information for subsequent treatment.This case supports the feasibility of craniotomy for the removal of glioma with AVM.

Ectopic recurrence following treatment of arteriovenous malformations in an adult:A case report and review of literature

BACKGROUND Digital subtraction angiography(DSA),the gold standard for the diagnosis of intracranial arteriovenous malformations(AVMs),can show clean nidus resection,leading to a perceived cure.Most cases of intracranial AVM recurrence have been reported in pediatric patients.The conventional understanding indicates that AVMs arise when abnormal blood vessels develop between the fourth and eighth weeks of embryonic development,which coincides with the typical period of blood vessel formation in the brain.As such,recurrent ectopic AVM are rare in adults.CASE SUMMARY Herein,we present the case of a 31-year-old adult with a history of an intracranial AVM originally diagnosed with a symptomatic de novo cerebellar AVM formation.Recurrence was observed five years following angiographically-confirmed excision of the initial AVM.DSA performed prior to initial AVM resection indicated no cerebellar abnormalities.Moreover,the recurrent arteries exhibited differences in arteries and draining veins.In addition to reporting this case,we analyzed six previously-reported adult patients with similar ectopic recurrent AVMs.These cases are summarized to review and explore the potential causes of ectopic AVM recurrence in adults,which increase the likelihood of acquired AVM.CONCLUSION The clinical course of the reported patients demonstrated the possibility of ectopic AVM recurrence in adults.The median time between the diagnosis of the initial AVM and the occurrence of ectopic recurrent AVM in adults was 11 years(range:5–20 years).Magnetic resonance imaging follow-up for more than 10 years may be required in adult AVM-treated patients.

基于STAR-CCM+的海上风电运维母船水动力性能分析

船舶阻力直接影响船舶的快速性,船舶耐波性直接影响船舶的舒适性,因此需要对二者进行计算分析。本文选取两艘海上风电运维母船作为研究对象,使用STAR-CCM+软件,基于重叠网格和VOF方法建立数值模型,计算船型的静水阻力和在规则波下的运动响应,与物理模型试验结果对比,对船舶的水动力性能做出预报。将两船型的水动力性能进行对比,分析两船型的性能优劣,为运维母船的船型选择提供参考。

基于STAR-CCM+仿真软件的双体船水动力性能分析

以某双体船为研究对象,基于STAR-CCM+仿真软件,按网格无关性验证和时间步长无关性验证的要求,对双船体船静水阻力进行数值方法验证,证明数值计算结果的准确性。对不同片体间距、不同片体形态和不同斜向航行角度等工况进行数值计算,分析双体船水动力性能。计算结果表明:在双体船直航时,在片体间距比为0.2、弗劳德数为0.4的工况条件下,与同一航速的其他工况条件相比静水具有明显的骤升现象,且总阻力系数达最大值14.56×10^(-3);在片体外旋转2°时,与其他旋转角度相比阻力值最小。研究发现,无论是在直航还是斜向航行的情况下,双体船的总阻力系数均呈现先升后降的趋势,说明该船型在处于高速航行状态时具有一定的优越性。

CT and MRI Findings of Intracranial Cavernous Hemangioma Malformation

Objective:To investigate the computed tomography(CT)and magnetic resonance imaging(MRI)features of cavernous hemangioma malformation(CHM)to enhance diagnostic accuracy.Methods:The CT and MRI findings and clinical information of 23 patients with CHM were retrospectively analyzed.Results:CT examinations were conducted in 7 cases,while MRI was utilized in 23 cases.Additionally,SWI was employed in 5 cases and enhanced imaging techniques were applied in 14 cases.Among the observed lesions,20 cases presented with a singular lesion,whereas 3 cases exhibited multiple lesions.The lesions were located in 8 frontal lobes,6 cerebellums,2 brainstems,6 temporal lobes,1 basal ganglia,3 parieto-occipital lobes,and 2 thalamus regions.The nodules appeared as quasi-circular lesions with clear or well-defined boundaries.They presented as isodense lesions on CT scans,with one lesion showing peritumoral edema.On MRI,T1-weighted imaging(T1WI)demonstrated isointense signals,while T2-weighted imaging(T2WI)showed isointense and hyperintense signals.Additionally,10 lesions exhibited a low signal ring on T2WI.Diffusion-weighted imaging(DWI)revealed nodular or isointense low signals,while susceptibility-weighted imaging(SWI)displayed enlarged areas of low signal.Fourteen lesions underwent contrast-enhanced scanning,with 2 lesions showing no obvious enhancement,1 lesion demonstrating mild to moderate enhancement,and 11 lesions exhibiting significant enhancement.Notably,6 of these enhanced lesions were surrounded by small blood vessels.Conclusion:Cavernous hemangioma malformation is more commonly found in individual cases.CT alone lacks specificity,making it prone to misdiagnosis.A more comprehensive evaluation of cavernous hemangioma malformation can be achieved through a combination of MRI,DWI,SWI,and enhanced examination,providing valuable references for clinical assessment.

基于STAR-CCM+的深远海网箱结构设计与分析研究

为解决网箱传统养殖方式养殖密度高、水产品质量差等问题,设计了深远海网箱养殖平台。采用STAR-CCM+对网箱进行耦合分析,选择合适的松弛因子和库朗数来定义求解器,进行相应网箱物理模型设置。分析数据来源于嵊泗海域设置的临时观测点,利用潮流观测技术统计潮汐特征值。4个潮位观测点从表层到底层划分为6个观测层,分别进行大小潮期间实测最大流速统计,运用潮位潮流和余流分析法对数据进行合理分析,取站位完善数据进行网箱的水动力分析。结果显示在常规工况1.0 m/s、1.2 m/s和风暴工况2.0 m/s的流速下网箱结构均能满足设计要求。研究得出的结论能有效提高养殖海域的面积和水产品的质量,同时对其它类型的养殖装备也具有一定的参考意义。

基于STAR-CCM+的淋胶管淋胶均匀性研究

淋胶管是聚氨酯泡沫合成轨枕生产中的关键部件,其主要作用是将树脂淋胶到纱线上,淋胶管淋胶越均匀,产品成型质量越好。基于流体仿真软件——STAR-CCM+,研究了淋胶管各结构参数对淋胶均匀性的影响。结果表明:中间管内径越大,淋胶小孔处壁厚越厚,淋胶小孔孔径越小、数量越少,淋胶均匀性越好;而淋胶管入口内径对淋胶均匀性影响甚微。基于该研究结果,对淋胶管进行结构优化,优化后的淋胶管淋胶均匀性相比原结构具有明显改善,淋胶均匀性由71.9%提高到96.6%。该研究结果对于聚氨酯泡沫合成轨枕的实际生产及其他类似的淋胶管设计及应用都具有重要的参考价值。

CCM理论视角下青砖茶制作技艺数字化传播研究——以长盛川青砖茶为例

在数字时代,非遗传承呈现出传播主体规模化、传播过程交互化、传播媒体多元化等特点,沉浸式体验成为非遗传播的关键词。为破解长盛川青砖茶数字化传播过程中文化属性不突出、传播受众有限、传播形态单一等问题,本文以CCM理论为切入点,提出青砖茶制作技艺数字化传播的策略:一是抓取消费偏好,塑造沟通元,实现体验+社交的场景构建;二是加强传播接触,触发沟通元,形成非遗品牌的场所依恋;三是挖掘文化价值,延伸传播链,构筑多场景信息生态圈。

基于STAR-CCM+的进气道优化设计

为提高进气道设计效率,缩短开发时间,基于STAR-CCM+的进气道优化设计方法,建立汽油机进气道稳态参数化模型,利用STAR-CCM+Design Manager中的Sherpa优化算法进行目标为y滚流比和进入燃烧室的新鲜空气质量流量最大化的多目标优化。仿真结果表明:y滚流比和进入燃烧室的新鲜空气质量流量之间存在明显的trade-off竞争关系;与基准设计相比,最优设计的y滚流比提升了15.6%,进入缸内的空气质量流量提升了22.3%。该研究方法可以实现快速自动化的汽油机进气道优化设计,减少设计周期,提高设计效率。

基于STAR-CCM+的小型无人双体船水动力性能分析

[目的]旨在系统性研究小型无人双体船的水动力性能。[方法]基于STAR-CCM+数值仿真软件,数值模拟小型无人双体船在不同弗劳德数Fr下静水状态和自航状态时的水动力性能。仿真选用非稳态RANSE模型,使用动态流体相互作用(DFBI)模型和重叠网格功能模拟双体船的纵倾与垂荡,并采用体积力法代替推进器的作用。使用摩擦阻力系数经验公式验证小型无人双体船在静水状态下的仿真结果,同时将自航试验结果与自航状态下的仿真结果进行对比以验证仿真结果的准确性。[结果]结果表明,当推进器转速为3000 r/min时,小型无人双体船在自航状态下的总阻力与静水航状态下的相差21.099%;在不同的推进器转速下,小型无人双体船在自航状态下的推力仿真值与试验值间的相对误差均小于10%。[结论]仿真值与试验值的对比验证了仿真的可靠性,采用体积力法研究的船体在自航状态下的水动力性能与静水状态下的差异较大,所用数值方法可为进一步预报双体船的水动力性能提供参考。

Overview of peripheral arteriovenous malformations:From diagnosis to treatment methods

Based on the latest classification by the International Society for the Study of Vascular Anomalies in 2018,vascular malformations(VMs)can be categorized into simple,combined,VMs of major named vessels,and VMs associated with other anomalies.Simple VMs include lymphatic,venous,capillary,and arteriovenous malformations(AVMs).AVMs represent disorders of direct arteriovenous shunts caused by the absence of a capillary bed between the involved arteries and veins.This abnormal vascular communication causes arterial blood to accumulate in the venous vessels,thus resulting in venous hypertension and characteristic clinical manifestations,such as pulsation,tremors,and elevated temperature.AVMs can occur sporadically or as manifestations of syndromic lesions and are considered among the most complex and challenging VMs.The diagnosis and treatment of AVMs can vary depending on the lesion location and associated clinical symptoms,thus complicating their management.Herein,we discuss peripheral AVMs in terms of their clinical manifestations,imaging examinations,and staging systems to provide a comprehensive reference for the treatment,evaluation methods,and follow-up procedures for this vascular anomaly.

Embolization of brain arteriovenous malformations with squid co-polymer embolic material:Initial experience

Objective:To analyze the safety and effectiveness of the ethylene-vinyl alcohol copolymer(EVOH)liquid embolic agent Squid(Emboflu,Switzerland)for the treatment of brain arteriovenous malformations.Materials and procedures:Between April 2015 and July 2017,46 embolization treatments for brain arteriovenous malformations(BAVM)were performed in 25 patients using two Squid formulations(18 and 12).Six female and 19 male patients with a mean age of 34 years(range,9–62 years)were included.A total of 46 procedures were performed.The BAVMs were classified as Spetzler-Martin gradeⅡin 4 procedures,Ⅲin 27 procedures,and 1V in 15 procedures.Among the 25 patients,15 presented with hemorrhage,5 with seizures,and 5 with headache and neurology.The BAVMs were located in the temporal lobe in 5 patients,parietal lobe in 7 patients,frontal lobe in 3 patients,posterior fossa in 6 patients,basal ganglia in 3 patients,and parasagittal lobe in 1 patient.Results:The obliteration rate of the BAVMs ranged from 10%to 100%,with a mean of 33%.Most patients underwent their first or second embolization procedure.Four patients(8%)developed intracranial bleeding post procedure,with one death(2%).One patient(2%)experienced a seizure during the procedure;however,no intracranial bleeding was observed.Seven patients(15%)experienced perforations during catheter manipulation.One case(2%)of fractured catheter was recorded,but no significant complications were observed.The average volume of copolymer injected was 0.6 ml per nidus.Thirteen procedures used the Squid-12 formulation,29 procedures used the Squid-18 formulation,and 3 procedures used a combination of Squid-12 and-18 formulations.Conclusion:Squid is a safe and effective embolic agent for treating BAVMs.

The generation and properties of human cortical organoids as a disease model for malformations of cortical development

As three-dimensional“organ-like”aggregates,human cortical organoids have emerged as powerful models for studying human brain evolution and brain disorders with unique advantages of humanspecificity,fidelity and manipulation.Human cortical organoids derived from human pluripotent stem cells can elaborately replicate many of the key properties of human cortical development at the molecular,cellular,structural,and functional levels,including the anatomy,functional neural network,and interaction among different brain regions,thus facilitating the discovery of brain development and evolution.In addition to studying the neuro-electrophysiological features of brain cortex development,human cortical organoids have been widely used to mimic the pathophysiological features of cortical-related disease,especially in mimicking malformations of cortical development,thus revealing pathological mechanism and identifying effective drugs.In this review,we provide an overview of the generation of human cortical organoids and the properties of recapitulated cortical development and further outline their applications in modeling malformations of cortical development including pathological phenotype,underlying mechanisms and rescue strategies.