Early changes in corneal densitometry after FS-LASIK combined with accelerated corneal cross-linking for correction of high myopia

AIM:To observe the effects of femtosecond laserassisted excimer laser in situ keratomileusis combined with accelerated corneal cross-linking(FS-LASIK Xtra)on corneal densitometry after correcting for high myopia.METHODS:In this prospectively study,130 patients underwent FS-LASIK or FS-LASIK Xtra for high myopia.Their right eyes were selected for inclusion in the study,of which 65 cases of 65 eyes in the FS-LASIK group,65 patients with 65 eyes in the FS-LASIK Xtra group.Patients were evaluated for corneal densitometry at 1,3,and 6mo postoperatively using Pentacam Scheimpflug imaging.RESULTS:Preoperative differences in corneal densitometry between the FS-LASIK and FS-LASIK Xtra groups in different ranges were not statistically significant(P>0.05).Layer-by-layer analysis revealed statistically significant differences in the anterior(120μm),central,and total layer corneal densitometry between the FS-LASIK and FS-LASIK Xtra groups at 1 and 3mo postoperatively(all P<0.05),the FS-LASIK Xtra group is higher than that of the FS-LASIK group.Analysis of different diameter ranges showed statistically significant differences between the FS-LASIK group and the FS-LASIK Xtra group at 1mo postoperatively in the ranges of 0–2,2–6,and 6–10 mm(both P<0.05);At 3mo postoperatively,the FS-LASIK Xtra group is higher than that of the FS-LASIK group in the ranges of 0–2 and 2–6 mm(P<0.05).At 6mo postoperatively,there were no statistically significant differences in corneal densitometry between the FS-LASIK group and the FS-LASIK Xtra group in different diameter ranges(all P>0.05).CONCLUSION:There is an increase in internal corneal densitometry during the early postoperative period after FS-LASIK Xtra for correction of high myopia.However,the densitometry values decreased to the level of conventional FS-LASIK at 6mo after surgery,with the most significant changes observed in the superficial central zone.

基于Photo Sphere Viewer的轻量化可量测街景系统研究

随着新型基础测绘体系发展,测绘技术和装备不断升级,大量街景数据随着车载激光扫描工作一并被采集。针对该数据路线随机性大、密集程度高等特点,以及传统街景地图系统插件受限、扩展性不强、无法量测等局限,本文设计了基于Photo Sphere Viewer的轻量化可量测街景系统,在开源插件的基础上实现了对其组件的扩充、实现了行进方向、地图交互等系统功能的设计优化,进一步实现了基于深度图的街景地图量测功能。生产作业队伍对系统的使用结果表明,该系统可以辅助生产作业队伍进行属性采集、纹理更新、数据检查等多项工作,操作灵活便捷,且具有较强的可扩展性,便于基于生产需求进行改进调整,提高了生产效率,为新型基础测绘成果进一步深化应用提供了良好的借鉴作用。

照片治疗技术的引进与发展——评《照片治疗技术》(《Photo therapy Techniques》)

《照片治疗技术》的作者是加拿大心理学家朱迪·韦泽(Judy Weiser),被公认为照片治疗技术的世界权威。1982年,朱迪·韦泽在加拿大创立照片治疗中心,该中心是世界上相关艺术领域的网络基地和教学数据资源库。目前,《照片治疗技术》已经被翻译为意大利语、韩语和俄语出版发行,著作的部分章节被翻译为日语和德语发行。

Construction of all-organic low dielectric polyimide hybrids via synergistic effect between covalent organic framework and cross-linking structure

Polyimide(PI)is a promising electronic packaging material,but it remains challenging to obtain an all-organic PI hybrid film with decreased dielectric constant and loss without modifying the monomer.Herein,a series of allorganic PI hybrid films were successfully prepared by introducing the covalent organic framework(COF),which could induce the formation of the cross-linking structure in the PI matrix.Due to the synergistic effects of the COF fillers and the cross-linking structure,the PI/COF hybrid film containing 2 wt%COF exhibited the lowest dielectric constant of 2.72 and the lowest dielectric loss(tanδ)of 0.0077 at 1 MHz.It is attributed to the intrinsic low dielectric constant of COF and a large number of mesopores within the PI.Besides,the cross-linking network of PI prevents the molecular chains from stacking and improves the fraction of free volume(FFV).The molecular dynamics simulation results are well consistent with the dielectric properties data.Furthermore,the PI/COF hybrid film with 5 wt%COF showed a significant enhancement in breakdown strength,which increased to 412.8 kV/mm as compared with pure PI.In addition,the PI/COF hybrid film achieve to reduce the dielectric constant and thermal expansion coefficient(CTE).It also exhibited excellent thermal,hydrophobicity,and mechanical performance.The all-organic PI/COF hybrid films have great commercial potential as next-generation electronic packaging materials.

Cross-Linking of Sago Starch with Furan and Bismaleimide via the Diels-Alder Reaction

This research paper describes the synthesis of thermo-reversible cross-linking of sago starch by grafting a furan pendant group(methyl 2-furoate)onto the starch backbone,followed by a Diels-Alder(DA)reaction of the furan functional group with 1,1′-(methylenedi-4,1-phenylene)bismaleimide(BM).The proof of principles was provided by FTIR and 1H-NMR analyses.The relevant FTIR peaks are the carbonyl peak(υC=O sym)at 1721 cm^(−1);the two peaks appeared after DA cross-linking,i.e.,at 1510 cm^(−1)(corresponding toυCH=CH BM aromatic rings,stretching vibrations),and at 1173 cm^(−1)(assigned to cycloadduct(C-O-C,δDA ring))while the^(1)H-NMR result shows evidence for the presence of a furan ring in the starch matrices(in the range ofδ6.3-7.5 ppm).The crosslinked starch product is indeed thermally reversible,as is evident from the appearance of exothermal(DA,temperature range of 50℃-70℃)and endothermal(retro DA,temperature range of 125℃-150℃)transitions in the DSC thermograms.This paper not only proves the thermal reversibility but also demonstrates that the final product properties(chemical,morphology,and thermal stability)can be tuned by varying the annealing temperature,BM intake,and reaction time.

Photo-induced Alignment Behavior of Azobenzene-containing Polymer Films with Different Cross-linking Degree

Three series of amorphous copolymers containing azobenzene groups with various substituents and certain amounts of crosslinkable acrylic groups were prepared. The cross-linked polymer films were obtained by thermal polymerization of the acrylic groups in the copolymers, during which, by controlling the time of cross-linking reaction, the films can be made with different cross-linking degree （from 0 to 32%, which was monitored by FT-IR spectra measurement）. Photo-induced alignment process of the films was performed under irradiation with linearly polarized light at 442 nm, and the effect of cross-linking degree on the photo-induced alignment rate was investigated. The dynamics of the photo-induced alignment was analyzed with biexponential curve fitting. The photo-induced alignment rate and the maximum transmittance of the films decreased because of the cross-linking. Furthermore, for the cross-linked samples, it was found that their saturated value of transmittances keep constant after repeated ＂writing＂ and ＂erasing＂ cycles. The findings reveal that the cross-linking of the film can effectively restrain the phototactic mass transport of azopolymer during irradiation by polarized light. The relationship between the cross-linking degree and the photo-induced alignment behavior of azopolymer is discussed in detail.

Mechanism of high Li-ion conductivity in poly(vinylene carbonate)-poly(ethylene oxide)cross-linked network based electrolyte revealed by solid-state NMR

Solid polymer electrolytes(SPEs)have become increasingly important in advanced lithium-ion batteries(LIBs)due to their improved safety and mechanical properties compared to organic liquid electrolytes.Cross-linked polymers have the potential to further improve the mechanical property without trading off Li-ion conductivity.In this study,focusing on a recently developed cross-linked SPE,i.e.,the one based on poly(vinylene carbonate)-poly(ethylene oxide)cross-linked network(PVCN),we used solid-state nuclear magnetic resonance(NMR)techniques to investigate the fundamental interaction between the chain segments and Li ions,as well as the lithium-ion motion.By utilizing homonuclear/heteronuclear correlation,CP(cross-polarization)kinetics,and spin-lattice relaxation experiments,etc.,we revealed the structural characteristics and their relations to lithium-ion mobilities.It is found that the network formation prevents poly(ethylene oxide)chains from crystallization,which could create sufficient space for segmental tumbling and Li-ion co nductio n.As such,the mechanical property is greatly improved with even higher Li-ion mobilities compared to the poly(vinylene carbonate)or poly(ethylene oxide)based SPE analogues.

Residual alkali-evoked cross-linked polymer layer for anti-air-sensitivity LiNi_(0.89)Co_(0.06)Mn_(0.05)O_(2)cathode

High-energy density lithium-ion batteries(LIBs)with layered high-nickel oxide cathodes(LiNi_(x)Co_(y)Mn_(1-x-y)O_(2),x≥0.8)show great promise in consumer electronics and vehicular applications.However,LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)faces challenges related to capacity decay caused by residual alkalis owing to high sensitivity to air.To address this issue,we propose a hazardous substances upcycling method that fundamentally mitigates alkali content and concurrently induces the emergence of an anti-air-sensitive layer on the cathode surface.Through the neutralization of polyacrylic acid(PAA)with residual alkalis and then coupling it with 3-aminopropyl triethoxysilane(KH550),a stable and ion-conductive cross-linked polymer layer is in situ integrated into the LiNi_(0.89)Co_(0.06)Mn_(0.05)O_(2)(NCM)cathode.Our characterization and measurements demonstrate its effectiveness.The NCM material exhibits impressive cycling performance,retaining 88.4%of its capacity after 200 cycles at 5 C and achieving an extraordinary specific capacity of 170.0 mA h g^(-1) at 10 C.Importantly,this layer on the NCM efficiently suppresses unfavorable phase transitions,severe electrolyte degradation,and CO_(2)gas evolution,while maintaining commendable resistance to air exposure.This surface modification strategy shows widespread potential for creating air-stable LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)cathodes,thereby advancing high-performance LIBs.

Tuning the cross-linked structure of basic poly(ionic liquid)to develop an efficient catalyst for the conversion of vinyl carbonate to dimethyl carbonate

Dimethyl carbonate(DMC)is a crucial chemical raw material widely used in organic synthesis,lithiumion battery electrolytes,and various other fields.The current primary industrial process employs a conventional sodium methoxide basic catalyst to produce DMC through the transesterification reaction between vinyl carbonate and methanol.However,the utilization of this catalyst presents several challenges during the process,including equipment corrosion,the generation of solid waste,susceptibility to deactivation,and complexities in separation and recovery.To address these limitations,a series of alkaline poly(ionic liquid)s,i.e.[DVBPIL][PHO],[DVCPIL][PHO],and[TBVPIL][PHO],with different crosslinking degrees and structures,were synthesized through the construction of cross-linked polymeric monomers and functionalization.These poly(ionic liquid)s exhibit cross-linked structures and controllable cationic and anionic characteristics.Research was conducted to investigate the effect of the cross-linking degree and structure on the catalytic performance of transesterification in synthesizing DMC.It was discovered that the appropriate cross-linking degree and structure of the[DVCPIL][PHO]catalyst resulted in a DMC yield of up to 80.6%.Furthermore,this catalyst material exhibited good stability,maintaining its catalytic activity after repeated use five times without significant changes.The results of this study demonstrate the potential for using alkaline poly(ionic liquid)s as a highly efficient and sustainable alternative to traditional catalysts for the transesterification synthesis of DMC.

Recent advances in phenazine-linked porous catalysts toward photo/electrocatalytic applications and mechanism

In recent years,porous organic catalysts have been developed and become research hotspots in photo/electrocatalysis due to their inherent pores,high specific surface area,chemical and thermal stability,and diverse functional building blocks.Phenazine-linked organic catalysts,exhibited excellent conjugation,electrical conductivity,chemical,and thermal stability,could bring in N atoms with specific numbers and positions to regulate electron levels,anchor metals,and absorb near-infrared light,which expands solar energy utilization.These advantages of the phenazine-linked catalysts attracted our group and numerous researchers to conduct experimental and computational work on photo/electrocatalytic applications and mechanisms.This review summarizes the recent significant research progress,synthesis methods,photo/electrocatalytic performance,and applications of relative phenazine-linked catalysts.Furthermore,the photo/electrocatalytic mechanism was systematized and summarized by combining experiments and density functional theory calculations simultaneously.

Topography versus non-topography-guided photorefractive keratectomy with corneal cross-linking variations in keratoconus

AIM:To compare the visual results of non-topographyguided and topography-guided photorefractive keratectomy(PRK)applying sequential and simultaneous corneal crosslinking(CXL)treatment for keratoconus.METHODS:Interventional and comparative prospective study.Sixty-nine eyes(36 patients)suffering from keratoconus(stages 1 Amsler-Krumeich classification)were divided into four groups:sequential topography-guided photorefractive keratectomy with CXL,simultaneous topography-guided photorefractive keratectomy with CXL,simultaneous nontopography guided photorefractive keratectomy with CXL,and sequential non-topography guided photorefractive keratectomy with CXL.The main outcome measures were pre-and postoperative uncorrected distance visual acuity(UDVA),best corrected distance visual acuity(CDVA),manifest refraction,contrast sensitivity,and keratometry.RESULTS:All analyzed visual,contrast sensitivity,and refractive parameters showed a significant improvement in the four groups(all P<0.05).A noticeable improvement was seen in keratometry in all the groups,and a remarkable difference was observed between topography-guided groups in comparison to non-topography-guided groups(P<0.05).Interestingly,the improvement in all parameters showed a degree of stability to the end of the follow-up.CONCLUSION:The treatment priorities in all four groups are safety,efficacy,and predictability in the correction of the sphero-cylindrical errors in mild and moderate keratoconus.No significant differences among groups in the recorded objective outcomes were found.

Water Photomolecular Evaporation Due to Light-Mediated Ortho-Para Spin Transitions

Recent discoveries have revealed a groundbreaking phenomenon where light alone, without any thermal input, can induce water evaporation, termed the “photomolecular effect”. This study explores a novel hypothesis that this effect can be explained by ortho-para magnetic spin interactions in water molecules within the water-air interface layer. Water molecules, consisting of hydrogen and oxygen, exhibit different nuclear spin states: ortho-(triplet) and para-(singlet). The interaction of polarized light with these spin states may induce transitions between the rotational levels of ortho- and para-forms due to catalysts like triplet oxygen (O2) in its inhomogeneous magnetic field. Resonance pumping at 532 nm (~18,797 cm−1) due to the transition v1-v2-v3 ~ 0-8-2 (~18,796 cm−1) results in an increase in molecular energy sufficient to overcome intermolecular forces at the water surface, thereby causing evaporation. The proposed ortho-para conversion mechanism involves spin-orbit coupling and specific resonance conditions. This theory provides a quantum mechanical perspective on the photomolecular effect, potentially offering insights into natural processes such as cloud formation and climate modeling, as well as practical applications in solar desalination and industrial drying. Further experimental validation is required to confirm the role of spin interactions in light-induced water evaporation.

Photo-activated microtubule targeting drugs: Advancing therapies for colorectal cancer

Over the years immunotherapy has demonstrably improved the field of cancer treatment.However,achieving long-term survival for colorectal cancer(CRC)patients remains a significant unmet need.Combination immunotherapies incor-porating targeted drugs like MEK or multi-kinase inhibitors have offered some palliative benefit.Nevertheless,substantial gaps remain in the current therapeutic armamentarium for CRC.In recent years,there has been a surge of interest in exploring novel treatment strategies,including the application of light-activated drugs in conjunction with optical devices.This approach holds promise for achie-ving localized and targeted delivery of cytotoxic agents,such as microtubule-targeting drugs,directly to cancerous cells within the colon.

Showcasing BRI’s Benefits Photo exhibition gives visual credence to the Belt and Road Initiative’s positive impact in Africa

Farmer Samuel Kisilu,aged 45,has been a resident of Nairobi for many years and seen Kenya undergo a variety of economic transformations since the 1980s.

PERVAPORATION PROPERTIES OF PDMS MEMBRANES CURED WITH DIFFERENT CROSS-LINKING REAGENTS FOR ETHANOL CONCENTRATION FROM AQUEOUS SOLUTIONS

Ethanol perm-selective PDMS/PVDF composite membranes were prepared by curing polydimethylsiloxane (PDMS) with various cross-linking reagents,such as tetraethoxylsilane(TEOS),γ-aminopropyltriethoxylsilane(APTEOS), phenyltrimethoxylsilane(PTMOS) and octyltrimethoxylsilane(OTMOS) as well.The cross-linking density and surface properties of the PDMS active layer were adjusted by varying cross-linking reagents.The pervaporation performance of PDMS membranes cured with different cross-linking reagents was investig...

Experimental study on the treatment of rabbit corneal melting after alkali burn with Collagen cross-linking

AIM: To evaluate the effect of Collagen cross-linking on the prevention of melting in rabbit corneas after alkali burn. METHODS: Twenty New Zealand white rabbits were randomly divided into model control group and collagen cross-linking treatment group. The second group of rabbits received collagen cross linked treatment. Both groups were applied with antibiotic eye drops to prevent infection. The corneas were evaluated for melting, opacity, pathological and immunohistochemistry, record the changes when 28 days after the animals were killed. RESULTS: In the control group, 6 out of 8 rabbits showed corneal melting after injury (14 +/- 4) days, while two corneal perforated. In collagen cross-linking treatment group, one rabbit showed corneal melting after injury 23 days, without corneal perforation; corneal dissolution rate between the two groups was significantly different (P <0.05). Pathological examination suggested that in the treatment group, mild corneal edema, mild damage to collagen fibers, inflammatory cell infiltration was significantly less than the control group. Immunohistochemistry showed that corneal collagen fibers arranged in neat rows in the control group. CONCLUSION: Collagen cross-linking treatment not only can prevent and delay the corneal melting after alkali burn, but also can reduce the destruction of corneal collagen fibers and infiltration of inflammatory cells in the corneal tissue.

Radiation-induced cross-linking:a novel avenue to permanent 3D modification of polymeric membranes

Membrane fouling is always the biggest problem in the practice of membrane separation technologies,which strongly impacts their applicability,separation efficiency,cost effectiveness,and service lifespan.Herein,a simple but effective 3D modification approach was designed for permanently functionalizing polymeric membranes by directly cross-linking polyvinyl alcohol(PVA)under gamma-ray irradiation at room temperature without any additives.After the modification,a PVA layer was constructed on the membrane surface and the pore inner surface of polyvinylidene fluoride(PVDF)membranes.This endowed them with good hydrophilicity,low adsorption of protein model foulants,and easy recoverability properties.In addition,the pore size and distribution were customized by controlling the PVA concentration,which enhanced the rejection ability of the resultant membranes and converted them from microfiltration to ultrafiltration.The crosslinked PVA layer was equipped with the resultant membranes with good resistance to chemical cleaning by acidic,alkaline,and oxidative reagents,which could greatly prolong the membrane service lifetime.Furthermore,this approach was demonstrated as a universal method to modify PVDF membranes with other hydrophilic macromolecular modifiers,including polyethylene glycol,sodium alginate,and polyvinyl pyrrolidone.This modification of the membranes effectively endowed them with good hydrophilicity and antifouling properties,as expected.

A short-term study of corneal collagen cross-linking with hypo-osmolar riboflavin solution in keratoconic corneas

AIM: To report the 3mo outcomes of collagen crosslinking(CXL) with a hypo-osmolar riboflavin in thin corneas with the thinnest thickness less than 400 μm without epithelium.METHODS: Eight eyes in 6 patients with age 26.2±4.8y were included in the study. All patients underwent CXL using a hypo-osmolar riboflavin solution after its de-epithelization. Best corrected visual acuity, manifest refraction, the thinnest corneal thickness, and endothelial cell density were evaluated before and 3mo after the procedure.RESULTS: The mean thinnest thickness of the cornea was 408.5 ±29.0 μm before treatment and reduced to369.8 ±24.8 μm after the removal of epithelium. With the application of the hypo-osmolar riboflavin solution, the thickness increased to 445.0 ±26.5 μm before CXL and recover to 412.5 ±22.7 μm at 3mo after treatment, P =0.659). Before surgery, the mean K-value of the apex of the keratoconus corneas was 57.6 ±4.0 diopters, and slightly decreased(54.7±4.9 diopters) after surgery(P =0.085). Mean best-corrected visual acuity was 0.55 ±0.23 logarithm of the minimal angle of resolution, and increased to 0.53±0.26 logarithm after surgery(P =0.879).The endothelial cell density was 2706.4 ±201.6 cells/mm2 before treatment, and slightly decreased( 2641. 2 ±218.2 cells/mm2) at last fellow up(P =0.002).CONCLUSION: Corneal collagen cross-linking with a hypo-osmolar riboflavin in thin corneas seems to be a promising treatment. Further study should be done to evaluate the safety and efficiency of CXL in thin corneas for the long-term.

Systematic review and Meta-analysis comparing modified cross-linking and standard cross-linking for progressive keratoconus

AIM：To compare the effectiveness and safety between modified cross-linking（MC）and standard cross-linking（SC）in mild or moderate progressive keratoconus.METHODS：Eligible studies were retrieved from four electronic databases,including CENTRAL,Clinical Trials gov,Pup Med and OVID MEDLINE.We set post-surgical maximum K value（Kmax）as the primary outcome.In addition,uncorrected and corrected distant visual acuity（UDVA and UDVA）,spherical equivalent（SE）,endothelial cell density（ECD）,central cornea thickness（CCT）and depth of demarcation line（DDL）were Meta-analyzed as secondary outcomes.Mean differences for these outcomes were pooled through either a random-effect model or fixed-effect model according to data heterogeneity.RESULTS：Twenty-four comparative studies either on accelerated cross-linking（AC）compared with SC or on transepithelial cross-linking（TC）compared with SC were included and pooled for analysis.The results indicated that MC was significantly inferior to SC at delaying Kmax deterioration[AC vs SC 0.49（95%CI：0.04-0.94,I2=75%,P=0.03）;TC vs SC 1.15（95%CI：0.54-1.75,I2=50%,P=0.0002）].SE decreased significantly for SC when compared to AC[0.62（95%CI：0.38-0.86,I2=22%,P〈0.00001）].DDL of SC was more significantly deeper than that of TC[-133.49（95%CI：-145.94 to-121.04,I2=33%,P〈0.00001）].Other outcomes demonstrated comparable results between MC and SC.CONCLUSION：SC is more favorable at halting the progression of keratoconus,but visual acuity improvement showed comparable results between MCs and SC.

Corneal collagen cross-linking and liposomal amphotericin B combination therapy for fungal keratitis in rabbits

AIM： To observe the therapeutic effect of corneal collagen cross-linking（CXL） in combination with liposomal amphotericin B in fungal corneal ulcers.METHODS： New Zealand rabbits were induced fungal corneal ulcers by scratching and randomly divided into 3groups, i.e. control, treated with CXL, and combined therapy of CXL with 0.25% liposomal amphotericin B（n =5 each）. The corneal lesions were documented with slit-lamp and confocal microscopy on 3, 7, 14, 21 and 28 d after treatment. The corneas were examined with transmission electron microscopy（TEM） at 4wk.RESULTS： A rabbit corneal ulcer model of Fusarium was successfully established. The corneal epithelium defect areas in the two treatment groups were smaller than that in the control group on 3, 7, 14 and 21d（P 〈0.05）. The corneal epithelium defect areas of the combined group was smaller than that of the CXL group（P 〈0.05） on 7 and 14 d, but there were no statistical differences on 3, 21 and 28 d. The corneal epithelium defects of the two treatment groups have been healed by day 21. The corneal epithelium defects of the control group were healed on 28 d. The diameters of the corneal collagen fiber bundles（42.960 ±7.383 nm in the CXL group and 37.040±4.160 nm in the combined group） were thicker than that of the control group（24.900±1.868 nm）,but there was no difference between the two treatment groups. Some corneal collagen fiber bundles were distorted and with irregular arrangement, a large number of fibroblasts could be seen among them but no inflammatory cells in both treatment groups. CONCLUSION： CXL combined with liposomal amphotericin B have beneficial effects on fungal corneal ulcers. The combined therapy could alleviate corneal inflammattions, accelerate corneal repair, and shorten the course of disease.