Corneal collagen cross-linking in patients with keratoconus from the Dresden protocol to customized solutions:theoretical basis

Keratoconus is an ectatic condition characterized by gradual corneal thinning,corneal protrusion,progressive irregular astigmatism,corneal fibrosis,and visual impairment.The therapeutic options regarding improvement of visual function include glasses or soft contact lenses correction for initial stages,gas-permeable rigid contact lenses,scleral lenses,implantation of intrastromal corneal ring or corneal transplants for most advanced stages.In keratoconus cases showing disease progression corneal collagen crosslinking(CXL)has been proven to be an effective,minimally invasive and safe procedure.CXL consists of a photochemical reaction of corneal collagen by riboflavin stimulation with ultraviolet A radiation,resulting in stromal crosslinks formation.The aim of this review is to carry out an examination of CXL methods based on theoretical basis and mathematical models,from the original Dresden protocol to the most recent developments in the technique,reporting the changes proposed in the last 15y and examining the advantages and disadvantages of the various treatment protocols.Finally,the limits of non-standardized methods and the perspectives offered by a customization of the treatment are highlighted.

SHEL:a semantically enhanced hardware-friendly entity linking method

With the help of pre-trained language models,the accuracy of the entity linking task has made great strides in recent years.However,most models with excellent performance require fine-tuning on a large amount of training data using large pre-trained language models,which is a hardware threshold to accomplish this task.Some researchers have achieved competitive results with less training data through ingenious methods,such as utilizing information provided by the named entity recognition model.This paper presents a novel semantic-enhancement-based entity linking approach,named semantically enhanced hardware-friendly entity linking(SHEL),which is designed to be hardware friendly and efficient while maintaining good performance.Specifically,SHEL's semantic enhancement approach consists of three aspects:(1)semantic compression of entity descriptions using a text summarization model;(2)maximizing the capture of mention contexts using asymmetric heuristics;(3)calculating a fixed size mention representation through pooling operations.These series of semantic enhancement methods effectively improve the model's ability to capture semantic information while taking into account the hardware constraints,and significantly improve the model's convergence speed by more than 50%compared with the strong baseline model proposed in this paper.In terms of performance,SHEL is comparable to the previous method,with superior performance on six well-established datasets,even though SHEL is trained using a smaller pre-trained language model as the encoder.

Unit-Linking PCNN中的彩色图像边缘检测

PCNN模型具有相似群神经元同步发放脉冲的特性,适合于图像分割。对彩色图像的亮度分量进行对数变换,使其更符合人眼的视觉特性;在PCNN进行彩色图像R、G、B三分量分割的过程中,利用遗传算法进行神经元关键参数的选择,利用偏态指标进行迭代控制;在Unit-Linking PCNN模型中实现R、G、B三分量分割图的边缘检测,利用加权合并策略得到最终的边缘检测结果。仿真结果表明,该方法得到的结果体现了图像中更多的轮廓细节,具有很好的自适应性。

A Brief Analysis of the Self-correction Model——from the View of Linking Theory

Based on the theory of the post method pedagogy and the teaching practice，this paper proposes a new teaching model，the self-correction model，and explains it from the point of view of linking theory.

Modeling online social networks based on preferential linking

We study the phenomena of preferential linking in a large-scale evolving online social network and find that the linear preference holds for preferential creation, preferential acceptance, and preferential attachment. Based on the linear preference, we propose an analyzable model, which illustrates the mechanism of network growth and reproduces the process of network evolution. Our simulations demonstrate that the degree distribution of the network produced by the model is in good agreement with that of the real network. This work provides a possible bridge between the micro=mechanisms of network growth and the macrostructures of online social networks.

Correlation between corneal demarcation line depth in epithelium-off and trans-epithelium accelerated corneal cross linking and keratoconus progression

AIM:To compare corneal demarcation line(DL)depth in both accelerated epithelium-off and trans-epithelium cross linking(CXL)using anterior segment optical coherence tomography(AS-OCT)and its relation to maximum keratometry(Kmax)progression in both techniques.METHODS:A prospective comparative interventional study where patients with mild to moderate keratoconus(KC)were classified into two groups:accelerated epitheliumoff and trans-epithelium CXL based on corneal pachymetry.Assessment of corneal DL depth was carried out after 3mo by AS-OCT.Kmax readings were evaluated after one year follow up using the Scheimpflug imaging system.RESULTS:Study included 74 eyes of 44 patients.Group A underwent epithelium-off CXL(41 eyes),while Group B underwent trans-epithelium CXL(33 eyes).At 3mo follow up,mean corneal DL depth in Group A was 219.9±58.4μm while in Group B was 127.2±7.8μm(P<0.05).The mean Kmaxchangedfrom51.9±3.9to51.3±4.2dioptersin Group A and from 53.1±4.1 to 53.6±5 diopters in Group B with insignificant difference in Kmax changes in either group(P>0.05).In addition,no significant change in corneal pachymetry was found in both groups(meanchange at 1y:6.4±4.7 and-10.1±2.3μm in Groups A and B respectively).CONCLUSION:Despite a significantly deeper corneal DL depth created by accelerated epithelium-off CXL technique compared to accelerated trans-epithelium CXL,there is no significant impact on keratoconus progression.

Linking China's emissions trading pilot schemes

All seven emissions trading pilots in China operate independently.One challenge facing most of them is the low inclusion thresholds for enterprises and the few total covered emissions,which negatively influences the effects of the emissions trading systems(ETSs).Some pilot sites,such as Guangdong,Hubei,Tianjin and Beijing,have indicated their willingness to link their schemes with others.ETS linking could expand scheme coverages and therefore help to reduce the overall costs of achieving the linked schemes' emissions control targets.Linking could also help to address the issues of carbon leakage and reduce price fluctuations.The potential benefits and feasibility of linking different pilot systems are analyzed in this article.The seven pilot regions are at different stages of social and economic development,with significant differences in total emissions and emissions structures as well as carbon abatement potentials and costs.Through linking,more-developed regions such as Beijing,Shanghai and Shenzhen,which are typically considered to face higher mitigation costs,will have the opportunity to achieve their emissions control targets by purchasing carbon units from less-developed regions,which will earn financial revenues from selling the units.To realize this win-win result,a series of policy and technical barriers at both the central government and pilot government levels needs to be overcome.Establishing a unified national emissions trading market would appear to be the ideal solution to these challenges,but it will take considerable time and will not be the short-term solution.In the absence of a unified national scheme,it is recommended that the central government encourage pilot schemes to link,that it develops corresponding national policies to support the linking efforts and that the pilot schemes that are intended to be linked coordinate on certain design elements.Based on the coordinating need,the major elements of an ETS can be divided into four categories:elements that need mutual recognition(cap setting and allowance allocation methods);elements that should be completely identical(compliance mechanisms,price containment measures,banking and borrowing rules,and offset mechanisms);technical elements that are preferably identical and easy to coordinate(MRV standards,technical registry standards);and elements that require no coordination(coverages and scopes).

Study on the Usage Patterns of Linking Adverbials in Chinese EFL Learn⁃ ers’Writings

This research is a corpus-based study on the usage patterns of linking adverbials(LA)by Chinese EFL learners at different proficiency levels,thus shedding light on problems facing students and analyzing underlying causes based on second language acquisition theories.Results show that Chinese high school students show a lack of richness in using LA,while Chinese undergraduates tend to overuse LA in an attempt to reach a superficial coherence.And in general,Chinese EFL learners have problems of overusing listing LA and underusing contrastive LA compared with their English native counterparts.

Preparation of Nano-porous Materials(Ⅱ) by Cross-linking of Amphiphilic Self-assemblies

Amphiphilic block copolymers can exhibit rich and complex morphologies in aqueous solutions, but these structures are usually delicate, easily disturbed by composition change or temperature change. In this work, the use of different methods to cross link block copolymer self assemblies in the presence of a selective solvent and to stabilize the structures is reviewed. In addition, the cross linking reaction kinetics of block copolymer amphiphilic self assemblies is briefly discussed.

Accelerated versus standard corneal cross linking in the treatment of ectasia post refractive surgery and penetrating keratoplasty: a medium term randomized trial

AIM: To compare the clinical outcomes of the standard corneal cross linking(CXL) and the accelerated CXL in patients with progressive corneal ectasia post refractive surgery and penetrating keratoplasty.METHODS: Totally 120 eyes of 83 patients scheduled to receive either standard CXL(3 m W/cm^2 for a period of 30 min) or accelerated CXL(18 m W/cm2 for a period of 5 min). The main outcomes for comparison were the change in: maximum-K reading(K-max), manifest refractive spherical equivalent(SE), central corneal thickness(CCT), and the best corrected distance visual acuity(CDVA).RESULTS: One hundred and eleven eyes completed the study. The main outcome measurement was the K-max reading. Both group showed significant improvement in the value postoperatively at 6 and 12 mo. The mean change in the standard group was 1.21±0.11 D and in the accelerated group was 0.90±0.05 D at the end of 12 mo postoperatively, with no statistically significant difference between the 2 groups. Similarly, CDVA improved significantly from their preoperative value in the standard group by 2.98±0.11 letters, and in the accelerated group by 2.20±0.06 letters, with no statistically significant difference between the two groups. Both of the SE, and CCT showed no statistically significant difference at the end of follow up period in each group.CONCLUSION: Both standard CXL and accelerated CXL are safe and effective treatment in halting ectasia after corneal refractive surgery. The accelerated CXL results are comparable to the standard CXL with short time exposure of the cornea to ultraviolet irradiation, leading to reduced operation time, reduced operative ocular discomfort, and corneal haze.

Long term efficacy and stability of corneal collagen cross linking for post-LASIK ectasia: an average of 80mo follow-up

This study was designed to evaluate efficacy and stability of corneal collagen crosslinking(CXL) in halting the progression of post-laser in situ keratomileusis(LASIK) ectasia and provide long-term follow-up results with an average of 80 mo. Patients with post-LASIK ectasia were treated with CXL between December 2007 and January 2012. Main outcome measures were uncorrected distance visual acuities(UDVA) and corrected distance visual acuities(CDVA), minimum and maximum keratometry(K) values, spherical and cylindrical refraction, and corneal thickness. The study evaluated 17 eyes for 13 patients(8 men, 5 women) with mean age of 31y(range 23 to 39) and mean follow-up of 80.7±15(range 57 to 102)mo. UDVA and CDVA improved from logMAR 0.53±0.36(20/63) to 0.49±0.4(20/50)(P=0.43) and from 0.18±0.17(20/28) to 0.16±0.16(20/27)(P=0.55) respectively. In 15 eyes UDVA and in 13 eyes CDVA either remained stable or improved ≥1 Snellen lines(88.2%) and(76.5%) respectively. Although statistically insignificant, spherical and cylindrical refraction decreased post-CXL from-1.26±2.87 to-0.38±2.32 diopters(D)(P=0.054) and from-3.80±2.47 to-3.04±2.18 D(P=0.13) respectively. Kmax significantly decreased from 44.23±3.76 to 42.85±3.08 D(P=0.013) and Kmin decreased from 41.07±3.61 to 40.00±2.65 D(P=0.057). Corneal thickness decreased from 470±42 to 460±41 μm, but was statistically non-significant(P=0.063). Therefore, CXL is effective in halting and partially reversing the progression of postLASIK ectasia on the long-term(mean follow-up of more than 80mo), thus highlighting the stability and maintained effect of CXL for such cases.

QUASILINEAR EQUATIONS USING A LINKING STRUCTURE WITH CRITICAL NONLINEARITIES

It is to establish existence of a weak solution for quasilinear elliptic problems assuming that the nonlinear term is critical.The potential V is bounded from below and above by positive constants.Because we are considering a critical term which interacts with higher eigenvalues for the linear problem,we need to apply a linking theorem.Notice that the lack of compactness,which comes from critical problems and the fact that we are working in the whole space,are some obstacles for us to ensure existence of solutions for quasilinear elliptic problems.The main feature in this article is to restore some compact results which are essential in variational methods.Recall that compactness conditions such as the Palais-Smale condition for the associated energy functional is not available in our setting.This difficulty is overcame by taking into account some fine estimates on the critical level for an auxiliary energy functional.

Linking axon transport to regeneration using in vitro laser axotomy

Spinal cord injury has devastating consequences because adult central nervous system （CNS） neurons do not regenerate their axons after injury. Two key reasons for axon regeneration fail- ure are extrinsic inhibitory factors and a low intrinsic capacity for axon regrowth. Research has therefore focused on overcom- ing extrinsic growth inhibition, and enhancing intrinsic regeneration capacity. Both of these issues will need to be addressed to enable optimal repair of the injured sp＋inal cord.

A Study of Human-Land Linking Policy Based on Urbanization Away from Home: A Case Study of Anhui Province

This paper analyzes the features and trends of urbanization away from home in Anhui Province,and believes that the cross-city floating population in the province shows a expanding scale,and dual cores of the province has obvious attractiveness. This paper also analyzes the relations between urban-rural construction land and urban-rural population transformation in the province,and expounds the possibility and necessity of carrying out human-land linking policy northern Anhui-Wanjiang. Based on the factors affecting human-land linking policy,this paper recommends that we should establish cross-regional trading policy system for land development rights in Anhui Province from four key links( urban entry,urban integration,rural exit,common urban-rural development),in order to effectively promote migrant workers' citizenization.

Effects of Cross Linking on the Chromatographic Nitrogen Isotope Separation

The effects of cross linking with porous cation exchange resin were studied for nitrogen isotope separation. The displacement chromatography was conducted by the resin with cross linking rang from 20% to 40%. A sharp adsorbed ammonium band was maintained for each operation. Enriched 15N isotopes with 0.93% were obtained by 20% cross linking resin and two meters chromatographic operation which started from the natural abundance of ammonium molecule. The effect of cross linking percentage on the height equivalent to a theoretical plate (HETP) was evaluated in the present work and the HETP value is proportional to the cross linking percentage. HETP value of 0.036 cm was obtained at the present system by using 20% cross linking resin.

Tufting Carpet Machine Information Model Based on Object Linking and Embedding for Process Control Unified Architecture

In view of the lack of research on the information model of tufting carpet machine in China,an information modeling method based on Object Linking and Embedding for Process Control Unified Architecture(OPC UA)framework was proposed to solve the problem of“information island”caused by the differentiated data interface between heterogeneous equipment and system in tufting carpet machine workshop.This paper established an information model of tufting carpet machine based on analyzing the system architecture,workshop equipment composition and information flow of the workshop,combined with the OPC UA information modeling specification.Subsequently,the OPC UA protocol is used to instantiate and map the information model,and the OPC UA server is developed.Finally,the practicability of tufting carpet machine information model under the OPC UA framework and the feasibility of realizing the information interconnection of heterogeneous devices in the tufting carpet machine digital workshop are verified.On this basis,the cloud and remote access to the underlying device data are realized.The application of this information model and information integration scheme in actual production explores and practices the application of OPC UA technology in the digital workshop of tufting carpet machine.

Linking Conditions for Models with Geometrical Basis

Usually it is demanded that the metric and its 1st derivatives have to match at the boundary of two adjacent regions which are solutions to Einstein’s field equation. We propose a new linking condition concerning gravitational models based on surfaces which could be embedded into a higher dimensional flat space. We probe this condition for the Schwarzschild interior and exterior solution.

The Lower Cretaceous Giant Dyke Swarms in the Arctic and Its Significance for linking of Siberia-Iceland Hot-Spot Track

Siberia-Iceland hot-spot track is the one of hot-spot track preserved on continent.Although this hot-spot track has clear plume"heads"-Siberia large igneous province,owing to thick continental lithosphere,its continuing

CHIC'98──A Rainbow Linking Garment Markets in Five Continents

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