基于弗洛凯特理论的Halo轨道辐轮构型编队控制设计

面向未来使用平动点航天器编队进行深空探测的需求,研究了特殊的定向辐轮构型航天器编队在日地L2平动点Halo轨道上的动力学和相关控制问题。首先,建立了圆型限制性三体问题(CRTBP)的相对动力学和辐轮构型编队模型的数学表达;其次,基于Floquet理论和傅里叶级数展开推导了Halo轨道的相对运动解析解,该解的推导同样可应用于其他小偏离的周期时变系统;接着,以深空探测任务为导向,基于Floquet模态法和LQR控制法分别给出编队主星和从星的分层控制策略;最后,对控制策略进行仿真,详细分析了辐轮构型维持控制力的规律等,得到了构型参数(半径和频率)与维持代价的关系。

地月周期轨道对地月L1与L2附近Halo轨道的可见性分析

随着去往月球航天器的增多,现有的近地空间光学卫星与地基光学望远镜的探测能力已无法满足要求,急需增强地月空间观测能力,通过使用地月周期轨道来填补地月空间观测能力的不足被认为是一种有效手段。针对地月周期轨道的特性,文章基于微分校正原理对三体轨道建模,并完成了算法的设计,提出了地月周期轨道的选择原则,并优选了3条轨道。在地月周期轨道对地月拉格朗日点L1、L2附近Halo轨道的可见性分析中,为方便评估,采用类球体的物体星等评估模型来定义可见性的评估标准;基于卫星工具包提供模型计算中涉及的自然天体、物体和观测卫星三者的时空关系,给出了可见性分析过程及结果,研究表明地月周期轨道对地月拉格朗日点L1、L2附近Halo轨道均有不错的观测效果,其中轨道1对地月周期轨道的可见性综合最高,均大于95%。

最佳Halo重力牵引治疗Lenke3型脊柱侧凸的生物力学分析

背景:Halo重力牵引是许多学者认可的术前牵引方法,但大部分为临床观察,缺乏有限元的相关分析。目的:运用有限元法探究Halo重力牵引对Lenke3型脊柱侧凸的最佳牵引力,从生物力学角度为临床提供理论依据。方法:对脊柱侧凸患者扫描的CT图像进行逆向建模处理并建立有限元模型,并取正常节段(T1-T4椎体)对模型的有效性进行验证。对腰胸椎侧凸模型设置5组不同的受力条件,模拟患者在不同牵引力作用下的矫正情况。5组皆将L5下表面完全约束,在T1上表面施加沿Z轴正方向(重力的反方向)不同大小的牵引力,分别为50,100,150,200,250 N。对比不同牵引力下侧凸脊柱的位移、主弯曲的Cobb角变化情况、脊柱的伸长量以及Von Mises应力。结果与结论:①当Halo重力牵引力为150-200 N时,主弯曲的Cobb角缩小量为最大缩小量的69.4%-88.9%,Z轴的伸长量是最大伸长量69.4%-85.9%,受到的应力为最大应力的63.6%-82.9%;②牵引力大于200 N,Cobb角的减少量和Z轴的伸长量变化不明显,但应力值急剧增长,且此时的T6、T7、T8椎体质心到L5中垂线的减小距离最为明显;③当Halo重力牵引力为150-200 N时,对此类型患者的矫正效果最佳——Cobb角缩小量与Z轴伸长量效果较佳的同时不会有应力的急剧增长。上述结果可为临床矫正提供一定的理论支持,可在较大程度矫正侧凸时保证患者安全。

微流星体碰撞对日地L_(2)点Halo轨道的影响

空间中存在大量高速运动的微流星体,与在轨运行的航天器发生碰撞后将导致轨道偏离、性能下降、结构破坏甚至航天器失效.由于Halo轨道具有不稳定的特性,本文主要探究微流星体碰撞对日地L_(2)点Halo轨道动力学演化规律的影响.首先,建立日地L_(2)点附近轨道的动力学模型,通过微分修正法构造Halo轨道的初始条件,基于Grün微流星体通量模型计算微流星体与航天器碰撞的数量和碰撞引起的速度改变量.然后,采用Runge-Kutta算法求解Halo轨道的动力学方程,研究碰撞速度改变量引起的轨道偏差随时间的演化规律.此外,采用状态转移矩阵方法分析初始状态偏差的演化规律,并与数值积分方法对比.最后基于状态转移矩阵方法分析了不同碰撞速度改变量的大小和方向引起的动力学响应.研究发现,状态转移矩阵在短时间内得到的结果与数值积分方法基本一致,而且只需一次矩阵乘法即可通过初始状态偏差计算得到末时刻状态偏差,具有非常高的效率.研究结果表明,由于Halo轨道固有的不稳定特性,所以初始时刻微流星体碰撞引起的微小状态偏差会快速增长,导致消耗更多控制燃料,最终将影响航天器的寿命.此外,微流星体碰撞的速度改变量的方向对偏差传递的规律有重要的影响.

Ultraconformable Integrated Wireless Charging Micro-Supercapacitor Skin

Conformable and wire-less charging energy storage devices play important roles in enabling the fast development of wearable,non-contact soft electronics.However,current wire-less charging power sources are still restricted by limited flexural angles and fragile connection of components,resulting in the failure expression of performance and constraining their fur-ther applications in health monitoring wearables and moveable artificial limbs.Herein,we present an ultracompatible skin-like integrated wireless charging micro-supercapacitor,which building blocks(including electrolyte,electrode and substrate)are all evaporated by liquid precursor.Owing to the infiltration and permeation of the liquid,each part of the integrated device attached firmly with each other,forming a compact and all-in-one configuration.In addition,benefitting from the controllable volume of electrode solution precursor,the electrode thickness is easily regulated varying from 11.7 to 112.5μm.This prepared thin IWC-MSC skin can fit well with curving human body,and could be wireless charged to store electricity into high capacitive micro-supercapacitors(11.39 F cm-3)of the integrated device.We believe this work will shed light on the construction of skin-attachable electronics and irregular sensing microrobots.

A Polyvinyl Alcohol/Acrylamide Hydrogel with Enhanced Mechanical Properties Promotes Full-Thickness Skin Defect Healing by Regulating Immunomodulation and Angiogenesis Through Paracrine Secretion

Hydrogel-based tissue-engineered skin has attracted increased attention due to its potential to restore the structural integrity and functionality of skin.However,the mechanical properties of hydrogel scaffolds and natural skin are substantially different.Here,we developed a polyvinyl alcohol(PVA)/acrylamide based interpenetrating network(IPN)hydrogel that was surface modified with polydopamine(PDA)and termed Dopa-gel.The Dopa-gel exhibited mechanical properties similar to native skin tissue and a superior ability to modulate paracrine functions.Furthermore,a tough scaffold with tensile resistance was fabricated using this hydrogel by three-dimensional printing.The results showed that the interpenetration of PVA,alginate,and polyacrylamide networks notably enhanced the mechanical properties of the hydrogel.Surface modification with PDA endowed the hydrogels with increased secretion of immunomodulatory and proangiogenic factors.In an in vivo model,Dopa-gel treatment accelerated wound closure,increased vascularization,and promoted a shift in macrophages from a proinflammatory M1 phenotype to a prohealing and anti-inflammatory M2 phenotype within the wound area.Mechanistically,the focal adhesion kinase(FAK)/extracellular signal-related kinase(ERK)signaling pathway may mediate the promotion of skin defect healing by increasing paracrine secretion via the Dopa-gel.Additionally,proangiogenic factors can be induced through Rho-associated kinase-2(ROCK-2)/vascular endothelial growth factor(VEGF)-mediated paracrine secretion under tensile stress conditions.Taken together,these findings suggest that the multifunctional Dopa-gel,which has good mechanical properties similar to those of native skin tissue and enhanced immunomodulatory and angiogenic properties,is a promising scaffold for skin tissue regeneration.

改良Halo骨盆牵引对重度脊柱畸形伴呼吸功能障碍患者的干预效果

目的探讨一期改良Halo骨盆牵引(halo-pelvic traction,HPT)联合二期手术对重度脊柱畸形伴呼吸功能障碍患者的应用效果。方法选取2019年1月至2022年1月北京大望路急诊抢救医院收治的120例重度脊柱畸形伴呼吸功能障碍患者作为研究对象。所有患者均行一期HPT牵引治疗和二期脊柱畸形矫形术。牵引前、牵引末次复查、内固定术后、末次随访,比较患者影像学指标和呼吸功能指标的变化情况。结果牵引前,患者主弯侧凸Cobb角、颈7铅垂线至骶骨正中线的距离(C7PL-CSVL)、顶椎偏距(AVT)、T1倾斜角、影像学肩高度、矢状面偏移(SVA)、腰胸椎后凸角(TK)为(119.17±15.39)°、(33.33±7.2)mm、(103.55±16.56)mm、(20.13±5.94)°、(26.78±6.32)mm、(38.29±5.54)mm、(87.66±11.63)°,高于牵引末次复查[(74.62±15.15)°、(13.23±4.27)mm、(57.70±17.56)mm、(9.29±1.73)°、(10.18±2.00)mm、(14.41±3.24)mm、(52.96±12.11)°]、内固定术后[(60.78±14.40)°、(12.42±3.58)mm、(44.31±13.77)mm、(8.89±2.66)°、(9.38±2.39)mm、(17.11±3.24)mm、(51.28±11.20)°]和末次随访[(64.21±14.86)°、(12.69±3.26)mm、(45.17±11.65)mm、(6.51±1.77)°、(9.53±2.36)mm、(17.50±3.07)mm、(51.82±12.20)°],差异有统计学意义(P<0.01)。牵引前,患者FVC、FVC%、FEV1、FEV1%为(1.13±0.19)L、(31.61±4.64)%、(1.08±0.22)L、(29.68±11.56)%,低于牵引末次复查[(1.36±0.28)L、(36.19±4.95)%、(1.17±0.19)L、(33.45±5.97)%]、内固定术后[(1.49±0.28)L、(38.08±7.46)%、(1.26±0.22)L、(35.91±7.81)%]和末次随访[(1.53±0.26)L、(38.61±6.91)%、(1.28±0.24)L、(36.88±7.85)%],差异有统计学意义(P<0.01)。结论改良HPT牵引能有效矫正重度脊柱畸形伴呼吸功能障碍患脊柱畸形,改善呼吸功能,是一种安全、有效地辅助治疗措施。

Bioengineered skin organoids:from development to applications

Signifcant advancements have been made in recent years in the development of highly sophisticated skin organoids.Serving as three-dimensional(3D)models that mimic human skin,these organoids have evolved into complex structures and are increasingly recognized as efective alternatives to traditional culture models and human skin due to their ability to overcome the limitations of two-dimensional(2D)systems and ethical concerns.The inherent plasticity of skin organoids allows for their construction into physiological and pathological models,enabling the study of skin development and dynamic changes.This review provides an overview of the pivotal work in the progression from 3D layered epidermis to cyst-like skin organoids with appendages.Furthermore,it highlights the latest advancements in organoid construction facilitated by state-of-the-art engineering techniques,such as 3D printing and microfuidic devices.The review also summarizes and discusses the diverse applications of skin organoids in developmental biology,disease modelling,regenerative medicine,and personalized medicine,while considering their prospects and limitations.

Halo-骨盆牵引治疗重度脊柱侧弯畸形的效果及其对肺功能的影响

目的探讨Halo-骨盆牵引(HPT)治疗重度脊柱侧弯畸形的效果及其对肺功能的影响。方法回顾性分析2021-01至2023-10北京大望路急诊抢救医院收治的100例脊柱侧弯合并肺功能不全患者的临床资料作为研究对象,所有患者均行一期HPT牵引治疗和二期脊柱侧弯矫形术。牵引前、牵引末次复查、内固定术后,比较患者影像学指标和肺功能指标的变化情况。采用Pearson统计学相关性分析主弯Cobb角对肺功能指标的影响。结果纳入患者肺功能结果显示,牵引前、牵引末次复查、内固定术后比较,限制性通气功能参数均存在不同程度增高(P<0.05)。相关分析表明,随着主弯Cobb角减小,肺限制性通气功能参数呈显著负相关性(P<0.05)。结论HPT牵引能有效矫正重度脊柱侧弯畸形,改善呼吸功能,是一种安全、有效的辅助治疗措施。

A Comprehensive Systematic Review: Advancements in Skin Cancer Classification and Segmentation Using the ISIC Dataset

The International Skin Imaging Collaboration(ISIC)datasets are pivotal resources for researchers in machine learning for medical image analysis,especially in skin cancer detection.These datasets contain tens of thousands of dermoscopic photographs,each accompanied by gold-standard lesion diagnosis metadata.Annual challenges associated with ISIC datasets have spurred significant advancements,with research papers reporting metrics surpassing those of human experts.Skin cancers are categorized into melanoma and non-melanoma types,with melanoma posing a greater threat due to its rapid potential for metastasis if left untreated.This paper aims to address challenges in skin cancer detection via visual inspection and manual examination of skin lesion images,processes historically known for their laboriousness.Despite notable advancements in machine learning and deep learning models,persistent challenges remain,largely due to the intricate nature of skin lesion images.We review research on convolutional neural networks(CNNs)in skin cancer classification and segmentation,identifying issues like data duplication and augmentation problems.We explore the efficacy of Vision Transformers(ViTs)in overcoming these challenges within ISIC dataset processing.ViTs leverage their capabilities to capture both global and local relationships within images,reducing data duplication and enhancing model generalization.Additionally,ViTs alleviate augmentation issues by effectively leveraging original data.Through a thorough examination of ViT-based methodologies,we illustrate their pivotal role in enhancing ISIC image classification and segmentation.This study offers valuable insights for researchers and practitioners looking to utilize ViTs for improved analysis of dermatological images.Furthermore,this paper emphasizes the crucial role of mathematical and computational modeling processes in advancing skin cancer detection methodologies,highlighting their significance in improving algorithmic performance and interpretability.

Regulatory T cells in skin regeneration and wound healing

As the body’s integumentary system,the skin is vulnerable to injuries.The subsequent wound healing processes aim to restore dermal and epidermal integrity and functionality.To this end,multiple tissue-resident cells and recruited immune cells cooperate to efficiently repair the injured tissue.Such temporally-and spatially-coordinated interplay necessitates tight regulation to prevent collateral damage such as overshooting immune responses and excessive inflammation.In this context,regulatory T cells(Tregs)hold a key role in balancing immune homeostasis and mediating cutaneous wound healing.A comprehensive understanding of Tregs’multifaceted field of activity may help decipher wound pathologies and,ultimately,establish new treatment modalities.Herein,we review the role of Tregs in orchestrating the regeneration of skin adnexa and catalyzing healthy wound repair.Further,we discuss how Tregs operate during fibrosis,keloidosis,and scarring.

Atmospheric Particulate Matter 2.5(PM_(2.5))Induces Cell Damage and Pruritus in Human Skin

With the accelerated rate of urbanization in recent years,air pollution has become an environmental problem that requires urgent resolution,almost all of the world’s population exposed to pollution on a daily basis.Among the various air pollutants,the excessive dispersion and suspension of particulate matter(PM)in the air.

Anti-skin aging effects and bioavailability of collagen tripeptide and elastin peptide formulations in young and middle-aged women

Background:Collagen peptides(CP),including tripeptides and elastin peptides(EP),are known for their in vitro and in vivo anti-skin aging effects.Despite positive results in animal models,the combination effects of CP and EP and the bioavailability of CP in human studies,particularly in young and middle-aged women,remain underexplored.Objective:To evaluate the effects of an orally administered collagen drink combining CP and EP on the skin health of young and middle-aged women.Materials and Methods:A single-center,randomized,double-blind,parallel-controlled trial was conducted,utilizing the WONDERLABR fish collagen tripeptide beverage.Participants consumed the drink over an 8-week period.Results:Compared to the placebo group,the collagen drink group showed significant improvements in skin hydration(39.19%increase),transepidermal water loss(33.45%decrease),skin elasticity(25.37%increase),dermal collagen content(21.64%increase),pore size(7.94%decrease),wrinkle length(18.09%decrease),skin smoothness(2.85%improvement),and skin roughness(15.32%decrease).Overall pore volume decreased by 60%,and visual assessments indicated a decrease in skin luminosity by 15.20%and smoothness index by 22.55%.Mass spectrometry demonstrated a significant increase in collagen efficacy components,including blood pH and GPH levels(P<0.05).Conclusion:The study confirmed the combination nourishing and anti-skin aging effects of EP and CP on the skin of young and middle-aged women,demonstrating significant improvements in various skin parameters and good bioavailability of collagen peptides.

Nanozyme‑Engineered Hydrogels for Anti‑Inflammation and Skin Regeneration

Inflammatory skin disorders can cause chronic scarring and functional impairments,posing a significant burden on patients and the healthcare system.Conventional therapies,such as corticosteroids and nonsteroidal anti-inflammatory drugs,are limited in efficacy and associated with adverse effects.Recently,nanozyme(NZ)-based hydrogels have shown great promise in addressing these challenges.NZ-based hydrogels possess unique therapeutic abilities by combining the therapeutic benefits of redox nanomaterials with enzymatic activity and the water-retaining capacity of hydrogels.The multifaceted therapeutic effects of these hydrogels include scavenging reactive oxygen species and other inflammatory mediators modulating immune responses toward a pro-regenerative environment and enhancing regenerative potential by triggering cell migration and differentiation.This review highlights the current state of the art in NZ-engineered hydrogels(NZ@hydrogels)for anti-inflammatory and skin regeneration applications.It also discusses the underlying chemo-mechano-biological mechanisms behind their effectiveness.Additionally,the challenges and future directions in this ground,particularly their clinical translation,are addressed.The insights provided in this review can aid in the design and engineering of novel NZ-based hydrogels,offering new possibilities for targeted and personalized skin-care therapies.

The Application Progress of Skin Imaging Technology in Psoriasis

Skin imaging technologies such as dermoscopy, high-frequency ultrasound, reflective confocal microscopy and optical coherence tomography are developing rapidly in clinical application. Skin imaging technology can improve clinical diagnosis rate, and its non-invasiveness and repeatability make it occupy an irreplaceable position in clinical diagnosis. With the “booming development” of medical technology, skin imaging technology can improve clinical diagnosis rate. Researchers have made significant advances in assisting clinical diagnosis, prediction, and treatment of disease. This article reviews the application and progress of skin imaging in the diagnosis of psoriasis.

Alginate oligosaccharide-mediated butyrate-HIF-1α axis improves skin aging in mice

The“gut-skin”axis has been proved and is considered as a novel therapy for the prevention of skin aging.The antioxidant efficacy of oligomannonic acid(MAOS)makes it an intriguing target for use to improve skin aging.The present study further explored whereby MAOS-mediated gut-skin axis balance prevented skin aging in mice.The data indicated the skin aging phenotypes,oxidative stress,skin mitochondrial dysfunction,and intestinal dysbiosis(especially the butyrate and HIF-1a levels decreased)in aging mice.Similarly,fecal microbiota transplantation(FMT)from aging mice rebuild the aging-like phenotypes.Further,we demonstrated MAOS-mediated colonic butyrate-HIF-1a axis homeostasis promoted the entry of butyrate into the skin,upregulated mitophagy level and ultimately improving skin aging via HDAC3/PHD/HIF-1a/mitophagy loop in skin of mice.Overall,our study offered a better insights of the effectiveness of alginate oligosaccharides(AOS),promised to become a personalized targeted therapeutic agents,on gut-skin axis disorder inducing skin aging.

Isotopic dependence of the yield ratios of light fragments from different projectiles and their unified neutron skin thicknesses

The yield ratios of neutron-proton(R(n/p))and^(3)H-^(3)He(R(^(3)H∕^(3)He))with reduced rapidity from 0 to 0.5 were simulated at 50 MeV/u even-even ^(36−56)Ca+^(40)Ca,even-even ^(48−78)Ni+^(58)Ni,and ^(100−139)Sn(every third isotopes)+112 Sn for full reduced impact parameters using the isospin-dependent quantum molecular dynamics(IQMD)model.The neutron and proton density distributions and root-mean-square radii of the reaction systems were obtained using the Skyrme-Hartree-Fock model,which was used for the phase space initialization of the projectile and target in IQMD.We defined the unified neutron skin thickness asΔRnp=<r^(2)>^(1∕2) n−<r^(2)>^(1∕2)p,which was negative for neutron-deficient nuclei.The unifiedΔRnp values for nuclei with the same relative neutron excess from different isotopic chains were nearly equal,except for extreme neutron-rich isotopes,which is a type of scaling behavior.The yield ratios of the three isotopic chain-induced reactions,which depended on the reduced impact parameter and unified neutron skin thickness,were studied.The results showed that both R(n/p)and R(^(3)H∕^(3)He)decreased with a reduced impact parameter for extreme neutron-deficient isotopes;however,they increased with reduced impact parameters for extreme neutron-rich isotopes,and increased with theΔRnp of the projectiles for all reduced impact parameters.In addition,a scaling phenomenon was observed betweenΔR np and the yield ratios in peripheral colli-sions from different isotopic chain projectiles(except for extreme neutron-rich isotopes).Thus,R(n/p)and R(^(3)H∕^(3)He)from peripheral collisions were suggested as experimental probes for extracting the neutron or proton skin thicknesses of non-extreme neutron-rich nuclei from different isotopic chains.

Investigation of the cell composition and gene expression in the delayed-type hypersensitivity tuberculin skin test

Dear Editor,The tuberculin skin test(TST)reagents have continuously improved,with the ESAT6-CFP10(EC)test having recently been introduced,but are seldom based on the direction of the delayed-type hypersensitivity(DTH)mechanism.Previous studies only partially showed the infiltration and activation of immune cells and the production of cytokines of the skin induration[1,2],and lack the detailed measurements of cell proportions and gene expression in the DTH response.Therefore,in this study,we revealed the comprehensive characteristics of DTH by single-cell RNA sequencing(scRNA-seq)in the guinea pig tuberculosis(TB)model[Experimental Animal Welfare Ethics Committee,Beijing Tuberculosis and Thoracic Tumor Research Institute(2021-064)].

Unique Clinical Features of Curaderm when Treating Skin Cancers

Basal cell carcinoma is the most common form of skin cancer and the most frequently occurring form of all cancers. Conventional treatments to remove or destroy basal cell carcinoma are indiscriminate and also remove or destroy normal skin cells resulting in compromised cosmetic outcomes. Consequences of these treatments include body-image issues, anxiety, post-traumatic stress disorder, depression, and poorer quality of social and family life. A progressive topical cream formulation, Curaderm, containing the natural BEC glycoalkaloids, have shown to have advantages over conventional treatments. However, comprehensive clinical features of the skin cancer lesions during treatment with Curaderm have to date not been reported. This report shows that using unpublished data from a large number of patients with varying sizes, types and locations of basal cell carcinomas when treated with Curaderm in a phase 3 trial, an initial increase in size of the lesions occur, followed by a reverse course, leading to complete removal of the skin cancer. The specificity and mode of action of Curaderm explains the superior cosmetic outcomes when compared with conventional therapies.

The Value of Excipients and the Required Understanding of the Biological System in Product Development: An Impactful Example of Curaderm, a Topical Skin Cancer Treatment

The incidences of nonmelanoma skin cancer are increasing worldwide, and the ongoing war on its treatment necessitates the development of effective and non-invasive methods. Through basic and clinical research, non-invasive treatments like Curaderm have been developed, leading to improved quality of life for patients. Excipients, previously considered inactive ingredients, play a crucial role in enhancing the performance of topical formulations. The development of Curaderm emphasizes the importance of understanding the interactions between active ingredients, excipients, and the biological system to create effective and affordable pharmaceutical formulations. The systematic approach taken in the development of Curaderm, starting from the observation of the anticancer activity of natural solasodine glycosides and progressing through toxicological and efficacy studies in cell culture, animals, and humans, has provided insights into the pharmacokinetics and pharmacodynamics of solasodine glycosides. It is crucial to determine these pharmacological parameters within the skin’s biological system for maximal effectiveness and cost-effectiveness of a skin cancer treatment. Curaderm, as a topical treatment for nonmelanoma skin cancer, offers benefits beyond those obtained from other topical treatments, providing hope for improved quality of life for patients.