Analysis of macular microvasculature and thickness after ICL implantation in patients with myopia using optical coherence tomography

AIM:To investigate changes in macular vessels and thickness in myopic eyes after intraocular collamer lens(ICL)implantation using quantitative optical coherence tomography angiography(OCTA).METHODS:This retrospective included 73 myopic eyes of 73 patients(average age,27.53±6.16 y)who underwent ICL implantation(28 eyes were Toric ICL).Axial length(AL),uncorrected visual acuity(UCVA),refractive dioptre(RD),intraocular pressure(IOP)and OCTA were measured and compared with before and 1 wk,1,and 3 mo after surgery.OCTA was used to image vessel density(VD)and skeleton density(SD)in both the superficial(SCP)and deep capillary plexus(DCP).Central retinal thickness(CRT)and ganglion cellinner plexiform layer thickness(GCT)were also measured.Changes between pre-and postoperative measurements were analysed by repeated measures analysis of variance.RESULTS:Compared with preoperative data,postoperative data on UCVA revealed significant improvements in all patients(P<0.05).However,there was no significant difference in IOP.After the operation,CRT and GCT exhibited significant changes(P<0.05).Among these measures,CRT was significantly higher at one and three months postoperative(all P<0.01).GCT was significantly higher at 1 wk,1,and 3 mo postoperative(all P<0.01).Changes in VD and SD were nonsignificant in both the SCP and DCP.There was no difference in postoperative changes between the ICL and Toric ICL groups.CONCLUSION:ICL and Toric ICL implantation both have good efficacy and safety for myopic eyes,but macular area changes that occur after surgery need attention.

叶片数对轴流风机气动性能影响的数值研究

叶片数量是影响风机气动性能与经济性的重要因素。本文针对空调器室外机用轴流风机的性能要求,设计了二叶片、三叶片和四叶片轴流风机。采用数值计算方法,研究了叶片数量对轴流风机气动性能的影响。研究结果表明:叶片数量越少,湍流度越大,风机进出口气流扰动加剧,气动涡流噪声也随之增大;二叶片风机由于其叶片数最少,其出口风量相比四叶片风机减少了23.5%,三叶片风机相比四叶片风机其出口风量减少了4.7%。随着叶片数量的减少,尽管风机做功能力有所下降,但叶片用材减少,风机的加工制造成本也相应降低。

不同尾缘齿型结构的海鸥翼型气动声学研究

本文提取具有优良气动性能的海鸥翼型对其尾缘进行仿生重构以降低气动噪声。采用大涡模拟(LES)进行三维瞬态流场计算,结合Ffowcs Williams和Hawkings发展的FW-H方法进行远场声学求解。系统研究了雷诺数为9.0×104,攻角为0°条件下,基于仿海鸥翅膀翼型的常规尾缘锯齿翼型、正弦型尾缘锯齿翼型及熨斗型尾缘锯齿翼型的气动噪声特性。研究结果表明:与原型翼型相比,常规尾缘锯齿翼型的升阻比损失最小,熨斗型尾缘锯齿翼型的升阻比损失最大。正弦型尾缘锯齿翼型的远场降噪效果最好,平均降噪幅度为5.72dB。与其他两种齿型结构相比,正弦型尾缘锯齿翼型能更有效地减小湍流宽频噪声和翼型表面的压力脉动,使整体旋涡脱落噪声明显下降。而熨斗型尾缘锯齿翼型在减小涡结构展向相关性的同时加剧了纵向空间涡结构的脱落,使整体声压级降低幅度最小。

白内障超声乳化联合人工晶状体植入术后囊袋收缩综合征发生率及影响因素

目的:探讨白内障超声乳化联合人工晶状体植入术后囊袋收缩综合征(CCS)发生情况及其影响因素。方法:回顾性研究。选取2018-09/2021-12期间于我院行白内障超声乳化联合人工晶状体植入术治疗的白内障患者1987例1987眼为研究对象,记录白内障患者术后CCS发生情况并根据术后是否发生CCS分为CCS组和无CCS组,比较两组患者术前的临床资料,使用多因素Logistic回归分析白内障超声乳化伴人工晶状体植入术后CCS的影响因素并构建预测模型。结果:纳入患者1987例1987眼中术后发生CCS 38眼,术后CCS发生率为1.91%。CCS组中年龄≥65岁、糖尿病、青光眼、视网膜色素变性、葡萄膜炎、亲水性人工晶状体患者构成比显著高于无CCS组(均P<0.05)。经多因素Logistic逐步向前法回归分析显示年龄≥65岁、糖尿病、视网膜色素变性、葡萄膜炎、亲水性人工晶状体是影响白内障超声乳化联合人工晶状体植入术后CCS发生的危险因素(P<0.05),在术后CCS危险因素的回归系数构建的预测模型的拟合优度好(P=0.421)。结论:高龄、糖尿病、视网膜色素变性、葡萄膜炎以及人工晶状体材料性质是影响白内障超声乳化联合人工晶状体植入术后CCS发生的重要因素。

仿鸮翼叶片对轴流风机气动噪声特性的影响研究

基于逆向工程技术提取长耳鸮翅膀沿展向40%位置处的截面型线进行仿生翼型叶片重构,按照型线厚度分布规则应用于轴流风机叶片的改型设计中。由于轴流风机叶片的弯掠变化对风机气动性能有较大的影响,本文以原型风机的中弧线分布为依据,采用鸮翼的厚度分布进行轴流风机叶片的仿生设计。采用大涡模拟方法结合声类比FW-H方程的求解,对轴流风机的气动性能和噪声进行了数值模拟计算,并与原型风机性能进行比较,揭示了仿生叶片对轴流风机气动性能和噪声的影响。研究结果表明:仿生翼型既能保证轴流风机的气动性能,又能在一定程度上降低轴流风机的气动噪声。仿鸮翼叶片特殊的厚度分布有效降低了叶片表面的非定常压力作用和叶片表面的声压脉动强度。从获得的轴流风机的气动噪声频谱图可以看出:采用仿鸮翼叶片能够降低轴流风机中低频区域的宽频段噪声和离散噪声。

采用进气端叶片开槽降低多翼离心风机气动噪声的研究

叶轮是空调用离心风机风道系统的核心部分,对离心风机的气动性能和噪声有重要影响。本文设计了一种顶端开槽的多翼离心风机叶片,采用数值计算方法研究了叶片进气端开槽对空调用多翼离心风机气动性能和噪声的影响,通过实验测试验证了进气端开槽叶片的降噪效果。结果表明:采用叶片进气端开槽结构能够改善叶轮顶端间隙区域内低速流动状态,抑制叶轮通道内旋涡的扩展,有效降低风机宽频噪声。与原型多翼离心风机相比,采用叶片进气端开槽结构,在保持风量基本不变情况下,风机噪声下降了0.8dB。

叶片尾缘凹陷结构对空调用轴流风机性能的影响

根据建立的窗式空调用室外机的数值仿真模型,首先对室外轴流风机的风量-静压特性进行数值研究,通过与实验测量的比较,验证了本文数值计算的有效性。考虑到轴流风机降噪的要求,本文研究了两种叶片尾缘凹陷结构对轴流风机气动性能和噪声的影响。进一步考虑到轴流风机风量的提升要求,考察了叶片高度变化对轴流风机风量和噪声的影响。研究结果表明,轴流叶片尾缘的凹陷可以改善叶片表面压力分布,减小叶轮叶片尾迹,降低室外风机气动噪声。在不同转速下对空调用室外轴流风机的风量和噪声进行测量,发现在小风量条件下采用叶片尾缘凹陷结构可降低风机噪音1.0d B以上;在大风量条件下,采用叶片尾缘凹陷结构,降噪效果有所下降。如果保持叶轮转速和半径不变,在可装配条件下,叶片高度从58mm增加到79mm,空调用室外轴流风机的风量较原型增加了75m^3/h,增幅达15.5%。

采用吸力面仿鱼形叶片的多翼离心风机气动性能研究

为了更好地实现叶片表面的流动控制,提升多翼离心风机的气动性能。本文突破传统仿鱼形叶片型线设计的局限性,基于优化叶片中弧线和鱼体单侧轮廓线发展了一种吸力面仿鱼形叶片。首先采用Box-Behnken响应面实验设计方法对叶片的进口角、出口角、叶片数和轮径比进行参数化设计,通过二次回归拟合得到叶片参数与风量的函数关系及最优参数组合。然后将鱼体单侧轮廓线应用在具有最优设计参数的叶片上,以提升多翼离心风机的气动性能。通过数值模拟方法研究了叶片仿生设计对多翼离心风机气动性能的影响,揭示了吸力面仿鱼形设计叶片的流动控制机理。与原型相比,采用吸力面仿鱼形叶片的多翼离心风机风量增加了8.4%,效率提升了6.73%。研究结果表明:吸力面仿鱼形叶片的叶道内的流场分布明显优于单圆弧等厚叶片和传统仿鱼形叶片,其压力面型线保留了单圆弧等厚叶片的流动控制性能,吸力面型线仿生设计改善了叶片吸力面的流场分布,有效抑制了蜗舌处及其下游通道内的流动分离,提高了多翼离心风机叶轮的做功能力。

A construct of adipose-derived mesenchymal stem cells—laden collagen scaffold for fertility restoration by inhibiting fibrosis in a rat model of endometrial injury

Severe endometrium damage causes pathological conditions such as thin endometrium and intrauterine adhesion,resulting in uterine factor infertility.Mesenchymal stem cell(MSC)therapy is a promising strategy in endometrial repair;yet,exogenous MSCs still raise concerns for safety and ethical issues.Human adipose-derived mesenchymal stem cells(ADMSCs)residing in adipose tissue have high translational potentials due to their autologous origin.To harness the high translation potentials of ADMSC in clinical endometrium regeneration,here we constructed an ADMSCs composited porous scaffold(CS/ADMSC)and evaluated its effectiveness on endometrial regeneration in a rat endometrium-injury model.We found that CS/ADMSC intrauterine implantation(i)promoted endometrial thickness and gland number,(ii)enhanced tissue angiogenesis,(iii)reduced fibrosis and(iv)restored fertility.We ascertained the pro-proliferation,pro-angiogenesis,immunomodulating and anti-fibrotic effects of CS/ADMSC in vitro and revealed that the CS/ADMSC influenced extracellular matrix composition and organization by a transcriptomic analysis.Our results demonstrated the effectiveness of CS/ADMSC for endometrial regeneration and provided solid proof for our future clinical study.

Gene-activated dermal equivalents to accelerate healing of diabetic chronic wounds by regulating inflammation and promoting angiogenesis

Diabetic chronic wound,characterized by prolonged inflammation and impaired angiogenesis,has become one of the most serious challenges in clinic and pose a significant healthcare burden worldwide.Although a great variety of wound dressings have been developed,few of encouraged achievements were obtained so far.In this study,the gene-activated strategy was applied to enhance sustained expression of vascular endothelial growth factor(VEGF)and achieve better healing outcomes by regulating inflammation and promoting angiogenesis.The gene-activated bilayer dermal equivalents(Ga-BDEs),which has good biocompatibility,were fabricated by loading the nano-sized complexes of Lipofectamine 2000/plasmid DNA-encoding VEGF into a collagen-chitosan scaffold/silicone membrane bilayer dermal equivalent.The DNA complexes were released in a sustained manner and showed the effective transfection capacities to up-regulate the expression of VEGF in vitro.To overcome cutaneous contraction of rodents and mimic the wound healing mechanisms of the human,a reformative rat model of full-thickness diabetic chronic wound was adopted.Under the treatment of Ga-BDEs,speeding wound healing was observed,which is accompanied by the accelerated infiltration and phenotype shift of macrophages and enhanced angiogenesis in early and late healing phases,respectively.These proved that Ga-BDEs possess the functions of immunomodulation and pro-angiogenesis simultaneously.Subsequently,the better regeneration outcomes,including deposition of oriented collagen and fast reepithelialization,were achieved.All these results indicated that,being different from traditional pro-angiogenic concept,the up-regulated expression of VEGF by Ga-BDEs in a sustained manner shows versatile potentials for promoting the healing of diabetic chronic wounds.

In situ delivery of apoptotic bodies derived from mesenchymal stem cells via a hyaluronic acid hydrogel:A therapy for intrauterine adhesions

Stem cell-based and stem cell-derived exosome-based therapies have shown promising potential for endometrial regeneration and the clinical treatment of intrauterine adhesions(IUAs).Evidence shows that apoptosis occurs in a majority of grafted stem cells,and apoptotic bodies(ABs)play a critical role in compensatory tissue regeneration.However,the therapeutic potential of AB-based therapy and its mechanism have not been explored in detail.Here,a cell-free therapeutic strategy was developed by incorporating mesenchymal stem cell-derived ABs into a hyaluronic acid(HA)hydrogel to achieve endometrial regeneration and fertility restoration.Specifically,we found that the ABs could induce macrophage immunomodulation,cell proliferation,and angiogenesis in vitro.The HA hydrogel promoted the retention of ABs and facilitated their continuous release.In a murine model of acute endometrial damage and a rat model of IUAs,in situ injection of the AB-laden HA hydrogel could efficiently reduce fibrosis and promote endometrial regeneration,resulting in the fertility restoration.Consequently,ABs show good potential as therapeutic vesicles,and the AB-laden HA hydrogel appears to be a clinically feasible and cell-free alternative for endometrial regeneration and IUA treatment.

Development of data-driven thermal sensation prediction model using quality-controlled databases

Predicting the thermal sensations of building occupants is challenging,but useful for indoor environment conditioning.In this study,a data-driven thermal sensation prediction model was developed using three quality-controlled thermal comfort databases.Different machine-learning algorithms were compared in terms of prediction accuracy and rationality.The model was further improved by adding categorical inputs,and building submodels and general models for different contexts.A comprehensive data-driven thermal sensation prediction model was established.The results indicate that the multilayer perceptron(MLP)algorithm achieves higher prediction accuracy and more rational results than the other four algorithms in this specific case.Labeling AC and NV scenarios,climate zones,and cooling and heating seasons can improve model performance.Establishing submodels for specific scenarios can result in better thermal sensation vote(TSV)predictions than using general models with or without labels.With 11 submodels corresponding to 11 scenarios,and three general models without labels,the final TSV prediction model achieved higher prediction accuracy,with 64.7%–90.7%fewer prediction errors(reducing SSE by 3.2–4.9)than the predicted mean vote(PMV).Possible applications of the new model are discussed.The findings of this study can help in development of simple,accurate,and rational thermal sensation prediction tools.

Light-induced dynamic RGD pattern for sequential modulation of macrophage phenotypes

Due to the critical roles of macrophage in immune response and tissue repair,harnessing macrophage phenotypes dynamically to match the tissue healing process on demand attracted many attentions.Although there have developed many advanced platforms with dynamic features for cell manipulation,few studies have designed a dynamic chemical pattern to sequentially polarize macrophage phenotypes and meet the immune requirements at various tissue repair stages.Here,we propose a novel strategy for spatiotemporal manipulation of macrophage phenotypes by a UV-induced dynamic Arg-Gly-Asp(RGD)pattern.By employing a photo-patterning technique and the specific interaction between cyclodextrin(CD)and azobenzene-RGD(Azo-RGD),we prepared a polyethylene glycol-dithiol/polyethylene glycol-norbornene(PEG-SH/PEG-Nor)hydrogel with dynamic RGD-patterned surface.After irradiation with 365-nm UV light,the homogeneous RGD surface was transformed to the RGD-patterned surface which induced morphological transformation of macrophages from round to elongated and subsequent phenotypic transition from pro-inflammation to anti-inflammation.The mechanism of phenotypic polarization induced by RGD pattern was proved to be related to Rho-associated protein kinase 2(ROCK2).Sequential modulation of macrophage phenotypes by the dynamic RGD-patterned surface provides a remote and non-invasive strategy to manipulate immune reactions and achieve optimized healing outcomes.

Enhanced genome editing to ameliorate a genetic metabolic liver disease through co-delivery of adeno-associated virus receptor

Genome editing through adeno-associated viral(AAV) vectors is a promising gene therapy strategy for various diseases,especially genetic disorders. However, homologous recombination(HR) efficiency is extremely low in adult animal models. We assumed that increasing AAV transduction efficiency could increase genome editing activity, especially HR efficiency, for in vivo gene therapy. Firstly, a mouse phenylketonuria(PKU) model carrying a pathogenic R408W mutation in phenylalanine hydroxylase(Pah) was generated. Through co-delivery of the general AAV receptor(AAVR), we found that AAVR could dramatically increase AAV transduction efficiency in vitro and in vivo. Furthermore, co-delivery of SaCas9/sgRNA/donor templates with AAVR via AAV8 vectors increased indel rate over 2-fold and HR rate over 15-fold for the correction of the single mutation in Pah;mice. Moreover, AAVR co-injection successfully increased the site-specific insertion rate of a 1.4 kb Pah cDNA by 11-fold, bringing the HR rate up to 7.3% without detectable global off-target effects. Insertion of Pah cDNA significantly decreased the Phe level and ameliorated PKU symptoms. This study demonstrates a novel strategy to dramatically increase AAV transduction which substantially enhanced in vivo genome editing efficiency in adult animal models, showing clinical potential for both conventional and genome editing-based gene therapy.

In situ assembly of fibrinogen/hyaluronic acid hydrogel via knob-hole interaction for 3D cellular engineering

Hyaluronic acid(HA)-based hydrogels have applied widely for biomedical applications due to its biocompatibility and biodegradability.However,the use of initiators or crosslinkers during the hydrogel formation may cause cytotoxicity and thereby impair the biocompatibility.Inspired by the crosslinking mechanism of fibrin gel,a novel HA-based hydrogel was developed via the in situ supramolecular assembly based on knob-hole interactions between fibrinogen and knob-grafted HA(knob-g-HA)in this study.The knob-grafted HA was synthesized by coupling knob peptides(GPRPAAC,a mimic peptide of fibrin knob A)to HA via Michael addition.Then the translucent fibrinogen/knob-g-HA hydrogels were prepared by simply mixing the solutions of knob-g-HA and fibrinogen at the knob/hole ratio of 1.2.The rheological behaviors of the fibrinogen/knob-g-HA hydrogels with the fibrinogen concentrations of 50,100 and 200 mg/mL were evaluated,and it was found that the dynamic storage moduli(G0)were higher than the loss moduli(G00)over the whole frequency range for all the groups.The SEM results showed that fibrinogen/knob-g-HA hydrogels presented the heterogeneous mesh-like structures which were different from the honeycomb-like structures of fibrinogen/MA-HA hydrogels.Correspondingly,a higher swelling ratio was obtained in the groups of fibrinogen/knob-g-HA hydrogel.Finally,the cytocompatibility of fibrinogen/knob-g-HA hydrogels was proved by live/dead stainings and MTT assays in the 293T cells encapsulation test.All these results highlight the biological potential of the fibrinogen/knob-g-HA hydrogels for 3D cellular engineering.

An Organic Solvent-free Approach towards PDI/Carbon Cloth Composites as Flexible Lithium Ion Battery Cathodes

An acidic solution based method towards flexible lithium ion battery(LIB)cathodes is developed in this work with perylene diimide(PDI)as the electroactive component and carbon cloth(CC)as the current collector.In this approach,PDI is firstly dispersed in concentrated sulfuric acid(H2S04)and then deposited on CC substrate after the dilution of H2S04,which provides an organic solvent-free strategy to construct integrated LIB cathodes.The acdic solution based fabrication process also allows the facile adjusting of loading amounts of PDI in the cathodes,which can effectively influence the battery performances of the PDI/CC cathodes.As the result,the acidic solution processed PDI/CC cathode can deliver a high specific capacity of-36 mAh·g^-1 at the current density of 50 mA·g^-1 in both half cell with lithium foil as anode and full cell with pre-lithiated CC as anode.In both types of the batteries,the PDI/CC cathodes show good cycling stabilities by retaining^84%of the initial capacities after 300 charge-discharge cycles at 500 mA·g^-1.Additionally,the excellent mechanical stability of the PDI/CC cathode enables the LIBs in pouch cell to maintain the electrochemical performances under various bending states,demonstrating their potentials for flexible LIBs.

m4C DNA methylation regulates biosynthesis of daptomycin in Streptomyces roseosporus L30

Despite numerous studies on transcriptional level regulation by single genes in drug producing Actinomyces,the global regulation based on epigenetic modification is not well explored.N4-methylcytosine(m4C),an abundant epigenetic marker in Actinomycetes’genome,but its regulatory mechanism remains unclear.In this study,we identify a m4C methyltransferase(SroLm3)in Streptomyces roseosporus L30 and multi-omics studies were performed and revealed SroLm3 as a global regulator of secondary metabolism.Notably,three BGCs inΔsroLm3 strain exhibited decreased expression compared to wild type.In-frame deletion of sroLm3 in S.roseosporus L30 further revealed its role in enhancing daptomycin production.In summary,we characterized a m4C methyltransferase,revealed the function of m4C in secondary metabolism regulation and biosynthesis of red pigment,and mapped a series of novel regulators for daptomycin biosynthesis dominated by m4C methylation.Our research further indicated that m4C DNA methylation may contribute to a metabolic switch from primary to secondary metabolism in Actinomyces.