Stromal lenticule addition keratoplasty with corneal crosslinking for corneal ectasia secondary to FS-LASIK:a case series

●AIM:To explore the clinical efficacy and safety of stromal lenticule addition keratoplasty(SLAK)with corneal crosslinking(CXL)on patients with corneal ectasia secondary to femtosecond laser-assisted in situ keratomileusis(FS-LASIK).●METHODS:A series of 5 patients undertaking SLAK with CXL for the treatment of corneal ectasia secondary to FS-LASIK were followed for 4-9mo.The lenticules were collected from patients undertaking small incision lenticule extraction(SMILE)for the correction of myopia.Adding a stromal lenticule was aimed at improving the corneal thickness for the safe application of crosslinking and compensating for the thin cornea to improve its mechanical strength.●RESULTS:All surgeries were conducted successfully with no significant complications.Their best corrected visual acuity(BCVA)ranged from 0.05 to 0.8-2 before surgery.The pre-operational total corneal thickness ranged from 345-404μm and maximum keratometry(Kmax)ranged from 50.8 to 86.3.After the combination surgery,both the corneal keratometry(range 55.9 to 92.8)and total corneal thickness(range 413-482μm)significantly increased.Four out of 5 patients had improvement of corneal biomechanical parameters(reflected by stiffness parameter A1 in Corvis ST).However,3 patients showed decreased BCVA after surgery due to the development of irregular astigmatism and transient haze.Despite the onset of corneal edema right after SLAK,the corneal topography and thickness generally stabilized after 3mo.●CONCLUSION:SLAK with CXL is a potentially beneficial and safe therapy for advanced corneal ectasia.Future work needs to address the poor predictability of corneal refractometry and compare the outcomes of different surgical modes.

A 3-month comparison study of subjective and objective visual quality of small incision lenticule extraction and transepithelial photorefractive keratectomy in patients with low and moderate myopia

AIM:To compare the subjective and objective visual quality between small incision lenticule extraction(SMILE)and transepithelial photorefractive keratectomy(t PRK)in patients with low and moderate myopia.METHODS:Patients undertaking SMILE or t PRK for the correction of low and moderate myopia were consecutively recruited in this prospective cohort study with a 3-month follow-up period.Objective evaluation[visual acuity test,manifest refraction,wavefront aberrations,the total cut-off value of the total modulation transfer function(MTFcut-off),and Strehl ratio(SR)]and subjective evaluation of visual quality(quality-of-life questionnaire)were conducted before surgery and at days 1,7,30,and 90 after surgery.RESULTS:A total of 47 patients(94 eyes)with SMILE and 22 patients(22 eyes)with t PRK were enrolled.The uncorrected visual acuity(UCVA)was better in SMILE patients on day 7 after surgery(1.13±0.13 vs 0.99±0.17,t=4.85,P<0.001)but was comparable at days 30 and 90.At day 90,the SMILE group had a lower spherical equivalent(SE)than the t PRK group(0.04±0.31 vs 0.19±0.43,t=2.08,P=0.042).Total higher order aberrations(HOAs)were induced in both surgical types,which were more evident in the t PRK group with 3-mm pupil diameter(0.16±0.07 vs0.11±0.05,t=4.27,P<0.001)and 5-mm pupil diameter(0.39±0.17 vs 0.36±0.11,t=2.33,P=0.022).The MTFcut-offand SR showed a trend of improvement in both SMILE and t PRK patients but were statistically better in the SMILE group with both pupil diameters.There was a significant improvement of contrast sensitivity(CS)over baseline levels at the spatial frequency of 18 cycles/degree(c/d)in the SMILE group(F=2.72,P=0.033)and at 3 c/d(F=3.03,P=0.031),12 c/d(F=3.72,P=0.013),and 18 c/d(F=4.62,P=0.004)in the t PRK group.The subjective quality of life questionnaire showed a steady improvement in the SMILE group(F=8.31,P<0.001)but not the t PRK group.CONCLUSION:SMILE and t PRK are both safe and effective ways to correct low and moderate myopia.A generally better and quicker recovery of visual quality favors the application of SMILE in qualified patients.

Androgen and meibomian gland dysfunction:from basic molecular biology to clinical applications

Meibomian gland,the largest sebaceous gland of the body,is responsible for the biosynthesis of lipid layer of the tear film to prevent excessive evaporation.The loss of normal functions of meibomian gland,known as meibomian gland dysfunction(MGD),is a chronic disease and is the leading cause of dry eye symptoms in the clinics.Studies have found sex hormones,especially androgen,play vital roles in the regulation of the functions of meibomian gland.Recently,androgen has also been preliminarily applied in clinics for the treatment of MGD and showed promising results,especially in people with endogenous androgen deficiency.This review summarized the mechanisms of the function of androgen on meibomian gland based on molecular,animal,and clinical studies,and proposed evidence-based views about its potential applications for the treatment of MGD.

A 4H-SiC merged P–I–N Schottky with floating back-to-back diode

A novel 4 H-Si C merged P–I–N Schottky(MPS)with floating back-to-back diode(FBD),named FBD-MPS,is proposed and investigated by the Sentaurus technology computer-aided design(TCAD)and analytical model.The FBD features a trench oxide and floating P-shield,which is inserted between the P+/N-(PN)junction and Schottky junction to eliminate the shorted anode effect.The FBD is formed by the N-drift/P-shield/N-drift and it separates the PN and Schottky active region independently.The FBD reduces not only the Vturn to suppress the snapback effect but also the Von at bipolar operation.The results show that the snapback can be completely eliminated,and the maximum electric field(Emax)is shifted from the Schottky junction to the FBD in the breakdown state.

SYNTHESIS AND CHARACTERIZATION OF NOVEL BIPOLAR PPV-BASED COPOLYMER CONTAINING TRIAZOLE AND CARBAZOLE UNITS

Two new blue light-emitting PPV-based conjugated copolymers containing both an electron-withdrawing unit (triazole-TAZ) and electron-rich moieties (carbazole-CAR and bicarbazole-BCAR) were prepared by Wittig condensation polymerization between the triazole diphosphonium salt and the corresponding dialdehyde monomers. Their structures and properties were characterized by FT-IR, TGA, DSC, UV-Vis, PL spectroscopy and electrochemical measurements. The resulting copolymers are soluble in common organic solvents and thermally stable with a T-g of 147degreesC for TAZ-CAR-PPV and of 157degreesC for TAZ-BCAR-PPV. The maximum photoluminescence wavelengths of TAZ-CAR-PPV and TAZ-BCAR-PPV film appear at 460 nm and 480 nm, respectively. Cyclic voltammetry measurement demonstrates that TAZ-BCAR-PPV has good electrochemical reversibility, while TAZ-CAR-PPV exhibits the irreversible redox process. The triazole unit was found to be an effective pi-conjugation interrupter and can play the rigid spacer role in determining the emission colour of the resulting copolymer.

Transgenic dry eye mouse models: powerful tools to study dry eye disease

Dry eye disease(DED) is one of the most common chronic multifactorial ocular surface diseases with high prevalence and complex pathogenesis. DED results in several ocular discomforts, vision fluctuation, and even potential damage of the ocular surface, bringing heavy burdens both on individuals and the society. The pathology of DED consists of tear film hyperosmolarity and immune responses on the ocular surface. Mice are widely used for developing models that simulate human DED features for investigating its pathogenesis and treatment. DED can be classified into aqueous-deficiency dry eye(ADDE) and evaporative dry eye(EDE). ADDE can be further divided into Sj?gren syndrome dry eye(SSDE) and non-Sj?gren syndrome dry eye(NSSDE). SSDE mouse models include natural strains, typified by non-obese diabetic(NOD) mice, and genetically engineered ones, like Aire-/-and Id3 knockout mice. Intrinsic EDE mainly refers to meibomian gland dysfunction(MGD). Eda-/-Tabby, Sod1-/-, Elovl1-/-are the most common transgenic MGD mouse models. Transgenic mouse models provide useful tools for studying the pathogenesis of DED and evaluating its novel therapies. This review compares the major transgenic dry eye mouse models and discusses their applications in DED research.

Zizhu ointment promote shealing of diabetic foot ulcers by inhibiting inflammatory reaction

Objective:This study aims to explore the mechanism of Chinese medicine Zizhu substance in the ranging of diabetic foot ulcer model from the perspective of inflammatory response.Methods:High-fat feed and streptozotocin(STZ)were 2 to establish diabetes,And an experimental model of diabetic foot ulcer was established with constant temperature and constant pressure.Scald The intervention control of The experimental model that included physiologicalEnzyme-linked immunosorbent assay(ELISA)was used to detect serum nitric oxide NO,C-reactive protein(CRP)and interleukin-6(il-6),Western blot(WB)detection of nuclear factor-bp65(NF-B P65),c-jun n-terminal kinase(JNK),Phosphorylated phosatidylinositol 3-kinase(p-pi3k),Immunohistochemistry(IHC)detection of vascular endothelial growth factor(VEGF)and leukemic cell leuk-34(CD34)of wound tissues,A cold atomic absorption method to detect blood mercury(Hg)content,study purple The effect of Zhu substance on The inflammation of diabetic foot ulcers and The safety of drugs.Results:The expression of inflammatory factors in diabetic foot ulcer rats was who that in ordinary ulcers,Zizhu substance could reduce The expression of inflammatory factors(NO,CRP and IL-6)in diabetic foot ulcer rats.In the diabetic foot ulcer model,the activation of the nf-kappa B,JNK,PI3K pathway,Zizhu substance can significantly inhibit the phosphorylation of JNK and nf-kappa B P65,PI3K,reduce the inflammation of the wound,happens the expression of VEGF,CD34 and promote the wound Angiogenesis and the detection of blood mercury content in rats treated with Zizhu lought indicate that the drug has good safety.Conclusion:Zizhu substance can promote diabetic foot ulcer tissue repair and improve wound ranging by inhibiting inflammation-related pathways,Showing that Zizhu substance is a safe and effective drug for the treatment of diabetic foot ulcers.

The relationship between cellular immune level and diabetic foot in type 2 diabetic patients

Objective:To to investigate the correlation between the level of immune function and diabetic foot in type 2 diabetic patients.Methods:76 diabetic patients in our hospital from January 2017 to November 2019 were collected as the observation group(the observation group was divided into two subgroups:38 cases in DM group and 38 cases in DM+DF group)and 76 healthy people in the same period as the healthy control group.The level of cellular immunity in serum of the observation group and the healthy control group were compared,and the relationship between cellular immunity and diabetic foot was further explored Department.Results:there were significant differences in glycosylated hemoglobin and fasting blood glucose between the two groups(P<0.001);there were significant differences in CD8,CD25 and CD28 between the two groups(P<0.001).There were statistical differences in the course and age of diabetes between the two subgroups in the observation group(P<0.05);there were statistical differences in CD2,CD8,CD25 and CD28 between the two subgroups(P<0.05).Logistic regression analysis showed that CD8[or95%CI 0.920(0.850,0.995)]and CD25[or95%CI 0.764(0.619,0.943)]were independent influencing factors and risk factors of diabetic foot.Conclusion:the increased levels of CD8 and CD25 may increase the risk of diabetic foot.

Special Issue:In Memory of Professor Fosong Wang

Professor Fosong Wang was a leading polymer chemist and made great contributions in polymer science including synthetic rubber,stereospecific polymerization,conjugated polymers and biodegradable polymers.He was also a highly respected educator in the field of polymer.He was not only a professor,a mentor,but also an academic father to many students.

混合拉格朗日-欧拉描述的多孔介质渗流拉格朗日方程

传统数值模型大多使用偏微分方程来描述渗流问题,并使用加权余量和有限差分技术来求解该方程。这类方程建立在空间点的角度之上,在数学上源于无穷小的概念。本文发展了一种求解渗流问题的能量方法,将拉格朗日方程应用于渗流系统的描述,而非直接采用偏微分方程进行描述.通过对代表性体积单元的能量进行积分而建立拉格朗日泛函,并采用合理的广义坐标对该泛函进行变分得到系统控制方程。将所得到的积分方程,由拉格朗日描述转化为欧拉描述,以此提高计算精度.然后,使用中心型有限体积法对控制方程进行数值离散.最后,给出了两种渗流前缘评估方案:一种方案通过网格局部细化实现,另一种方案利用渗流前缘移动实现.本文所提出的模型是一个建立在能量观点上的模型,而非建立在偏微分动量方程基础之上.数值算例表明,该模型可给出物理上合理的计算结果.

A Cyano-Substituted Organoboron Electron-deficient Building Block for D-A Type Conjugated Polymers

The development of donor-acceptor(D-A)type conjugated polymers depends largely on the design of novel A building blocks.Herein,we report a novel A building block based on the cyano-substituted organoboron unit(SBN-3).Compared with the most common fluorine-substituted B←N unit,SBN-3 displays a significantly downshifted LUMO energy level because of the strong electron-withdrawing ability of cyano groups.In addition,due to the greater impact of cyano substitution on LUMO than on HOMO,SBN-3 exhibits a reduced band gap,nearinfrared absorption and fluorescence properties.The D-A type conjugated polymers based on the cyano-substituted B←N unit with thiophene-based units show narrow optical band gaps of ca.1.3 e V as well as distinctive electronic structures,i.e.,delocalized LUMOs and localized HOMOs.This work thus provides not only an effective approach to design strong A units but also a new electron-deficient building block for D-A type conjugated polymers.

Carbazole-based Multiple Resonance Dendrimers with Narrowband Blue Emission for Solution-Processed OLEDs

Three carbazole-based multiple resonance dendrimers namely D1-BNN,D2-BNN and D3-BNN,are developed for solution-processed narrowband blue organic light-emitting diodes(OLEDs)by introducing the first-,second-,and third-generation carbazole dendrons in periphery of boron,nitrogen-doped polycyclic aromatic hydrocarbon skeleton.Different from D1-BNN containing first-generation carbazole dendron showing moderate photoluminescent quantum efficiency(PLQY)of 68%in solid state and broadened emission bands with full-width at half maximum(FWHM)increasing from 26 nm to 34 nm upon doping concentration growing from 10 wt%to 40 wt%,D3-BNN with the third-generation carbazole dendron exhibits high PLQY of 92%and weak dependence of photoluminescent spectra on doping concentration,which can remain narrowband emissions with unchanged FWHM of 24 nm at same doping concentration range.Solution-processed OLEDs employing D3-BNN as emitter reveal blue electroluminescence at 477 nm with FWHM of 24 nm,and maximum external quantum efficiency(EQE)of 17.3%which is kept at 14.4%at doping concentration of 40 wt%,much superior than the D1-BNN devices showing maximum EQE of 13.0%that drops to 3.7%at 40 wt%doping concentration.

Acceptor-acceptor-type Organoboron Conjugated Polymers:Effect of Backbone Configuration on Thermoelectric Performance

The development of n-type polymer thermoelectrics lags far behind that of p-type ones in view of material diversity and performance.New structural insights into the thermoelectric performance are needed for efficient n-type polymer thermoelectric materials.Herein,we developed three acceptor-acceptor type organoboron polymers and investigated the effect of backbone configuration on thermoelectric performance.The three polymers are designed based on double B←N bridged bipyridine(BNBP)unit with monomeric thieno[3,4-c]pyrrole-4,6-dione(TPD),TPD dimer and TPD trimer as the copolymerizing units,respectively.The three polymers show similar low LUMO energy levels but different backbone configuration.Compared with the wavy backbone configuration,the pseudo-straight backbone configuration imparts the polymer with much enhanced crystallinity and electron mobility.As a result,after n-doping,the polymer with pseudo-straight configuration shows much higher electronic conductivity and power factor.We think these findings could serve as important guidelines for molecular design toward efficient n-type polymer thermoelectric materials.

光电高分子材料的研究进展

光电活性共轭高分子是高分子科学的前沿研究方向.共轭高分子光电材料的研究在中国引起了学术界的广泛兴趣,中国的学者们对推动此研究领域的发展做出了重要贡献,并在新的高性能光电共轭高分子的分子设计、新型及可控聚合、性能调控以及光电应用等方面取得了一系列重要的创新成果.本文总结和评述了中国学者在光电高分子领域的研究成果与最新进展,并展望了其未来的发展.

An Alternating Polymer of Two Building Blocks Based on B←N Unit:Non-fullerene Acceptor for Organic Photovoltaics

B-N coordination bond can be used to develop polymer electron acceptors for efficient all-polymer solar cells （all-PSCs）. Here, we report a new alternating conjugated polymer containing two building blocks based on B-N unit. The polymer exhibits strong light absorption in the visible range, low-lying LUMO/HOMO energy levels and moderate electron mobility. The resulting all-PSC devices exhibit power conversion efficiencies of 1.50%-2.47%.

Active Layer Morphology Engineering of All-polymer Solar Cells by Systematically Tuning Molecular Weights of Polymer Donors/Acceptors

In all-polymer solar cells(APSCs),number-average molecular weights(Mns)of polymer donors and polymer acceptors play an important role in active layer morphology and photovoltaic performance.In this work,based on a series of APSCs with power conversion efficiency of approaching 10%,we study the effect of Mns of both polymer donor and polymer acceptor on active layer morphology and photovoltaic performance of APSCs.We select poly[4-(5-(4,8-bis(5-((2-butyloctyl)thio)thiophen-2-yl)-6-methylbenzo[1,2-b:4,5-b’]dithiophen-2-yl)thiophen-2-yl)-5,6-difluoro-2-(2-hexyldecyl)-7-(5-methylthiophen-2-yl)-2 H-benzo[d][1,2,3]triazole](CD1)as the polymer donor and poly[4-(5-(5,10-bis(2-dodecylhexadecyl)-4,4,9,9-tetrafluuoro-7-methyl-4,5,9,10-tetrahydro3 a,5,8,10-tetraaza-4,9-diborapyren-2-yl)thiophen-2-yl)-7-(5-methylthiophen-2-yl)benzo[c][1,2,5]thiadiazole](PBN-14)as the polymer acceptor.The Mns of polymer donor CD1 are 14.0,35.5 and 56.1 kg/mol,respectively,and the Mns of polymer acceptor PBN-14 are 32.7,72.4 and 103.4 kg/mol,respectively.To get the desired biscontinueous fibrous network morphololgy of the polymer donor/polymer acceptor blends,at least one polymer should have high or medium Mn.Moreover,when the Mn of polymer acceptor is high,the active layer morphology and APSC device performance are insensitive to the Mn of polymer donor.The optimal APSC device performance is obtained when the Mn of both the polymer donor and the polymer acceptor are medium.These results provide a comprehensive and deep understanding on the interplay and the effect of Mn of polymer donors and polymer acceptors in highperformance APSCs.

Liquid crystal character controlled by complementary discotic molecules mixtures： Columnar stacking type and mesophase temperature range

In this work, the mesophase properties were tuned via mixing two discotic molecules with structural complementarity. Compared with the liquid crystalline hexakis（n-hexyloxy）triphenylene（H6TP）materials（columnar hexagonal phase from 53 ℃ to 91 ℃）, mesophase types as well as phase transition temperatures varied with the introduction of crystalline hexaazatriphenylene derivative（PBH）molecules. The introduction of less than 33% amount of PBH disrupted the columnar hexagonal phase formed by H6 TP remarkably, followed by the decreased clearing temperatures of liquid crystals. As the PBH amount was further increased, the destroyed columnar hexagonal phase was turned into the columnar rectangular phase, in which H6 TP and PBH molecules together formed the columnar mesophase. The formation of new mesophase contributed to the enlarged mesophase temperature（from44 ℃ to 144 ℃）. We speculated that the alkyl chains interaction induced by the PBH component competed with the strong p–p stacking between H6 TP molecules, thus altering the liquid crystalline properties including mesophase types and phase transition temperatures.

New applications of poly(arylene ether)s in organic light-emitting diodes

Compared with conventional π-conjugated polymers,poly（arylene ether）s（PAEs） may take advantages of excellent thermal properties,well-defined effective conjugated length and no catalyst contamination.Recently,their applications have been extended from engineering plastics to optoelectronic materials.In this review,various kinds of functional PAEs used as fluorescent polymers,host polymers and phosphorescent polymers in organic light-emitting diodes（OLEDs） are outlined,and their molecular design,synthesis and device performance are overviewed.

15%Efficiency All-Polymer Solar Cells Based on a Polymer Acceptor Containing B←N Unit

The development of new polymer acceptors strongly paves the power conversion efficiency(PCE)improvement of all polymer solar cells(all-PSCs).Herein,we develop a new polymer acceptor PBN26,which is the alternating copolymer of 2,2′-((2Z,2′Z)-((12,13-bis(2-octyldodecyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1 H-indene-2,1-diylidene))dimalononitrile and B←N bridged thienylthiazole(BNTT).The optimized all-PSCs device based on PBN26 exhibits a PCE of 15.09%,which is the highest value of the all-PSCs based on B←N-based polymer acceptors at present.Moreover,we also fabricate an all-PSC module with active area of 10 cm2 by blade coating,which exhibits a PCE of 8.78%.These results prove that polymer acceptors containing B←N units are promising for all-PSC device applications.

Special Issue:Organic Photovoltaic Polymers

Organic photovoltaic devices(OPVs)show promise as the next-generation clean-energy technology with diverse applications,due to their unique merits of low-cost production with solution processability,light-weight,ultra-flexibility,good visible transparency for solar windows,aesthetic with vivid color,etc.Since the discovery of photovoltaic effect by sandwiching the Anthracene with electrodes,the OPVs has drawn more and more attention.In the most recent years,comprehensive research on materials design,interface modification,morphology control,device structure design,etc.,leads to the rapid progress in OPV.