Tissue optical clearing enhances efficacy of vascular targeted photodynamic therapy of mouse dorsal skin

Vascular-targeted photodynamic therapy(V-PDT)is an effective treatment for port wine stains(PWS).However,repeated treatment is usually needed to achieve optimal treatment outcomes,possibly due to the limited treatment light penetration depth in the PWS lesion.The optical clearing technique can increase light penetration in depth by reducing light scattering.This study aimed to investigate the V-PDT in combination with an optical clearing agent(OCA)for the therapeutic enhancement of V-PDT in the rodent skinfold window chamber model.Vascular responses were closely monitored with laser speckle contrast imaging(LSCI),optical coherence tomography angiography,and stereo microscope before,during,and after the treatment.We further quantitatively demonstrated the effects of V-PDT in combination with OCA on the blood flow and blood vessel size of skin microvasculature.The combination of OCA and V-PDT resulted in significant vascular damage,including vasoconstriction and the reduction of blood flow.Our results indicate the promising potential of OCA for enhancing V-PDT for treating vascular-related diseases,including PWS.

A Comparative Study of the Power-law Relationship between the Pulse width and Energy of Precursor and Main Burst

In gamma-ray burst prompt emission,there is still no consistent conclusion if the precursor and main burst share the same origin.In this paper,we try to study this issue based on the relationship between pulse width and energy of the precursor and main burst.We systematically search the light curve data observed by Swift/BAT and Fermi/GBM,and find 13 long bursts with well-structured precursors and main bursts.After fitting the precursor light curve of each different energy channel with the Norris function,we find that there is not only a power-law relationship between precursor width and energy,but also a power-law relationship between the ratio of the rising width to the decaying width and energy.By comparing the relationship between the precursors and the main burst pulses,we find that the distribution of the precursors and the relationship between the power-law indices are roughly the same as those of the main burst.In addition,it is found that the precursor width distribution as well as the upper limit of the pulse width ratio does not exceed 1 and both are asymmetric,which are also consistent with the main burst.These indicate that the precursor and the main burst are indistinguishable,and the precursor and the main burst may have the same physical origin.

Characterization of physicochemical and immunogenic properties of allergenic proteins altered by food processing:a review

Food allergens are mainly naturally-occurring proteins with immunoglobulin E(IgE)-binding epitopes.Understanding the structural and immunogenic characteristics of allergenic proteins is essential in assessing whether and how food processing techniques reduce allergenicity.We here discuss the impacts of food processing technologies on the modification of physicochemical,structural,and immunogenic properties of allergenic proteins.Detection techniques for characterizing changes in these properties of food allergens are summarized.Food processing helps to reduce allergenicity by aggregating or denaturing proteins,which masks,modifies,or destroys antigenic epitopes,whereas,it cannot eliminate allergenicity completely,and sometimes even improves allergenicity by exposing new epitopes.Moreover,most food processing techniques have been tested on purified food allergens rather than food products due to potential interference of other food components.We provide guidance for further development of processing operations that can decrease the allergenicity of allergenic food proteins without negatively impacting the nutritional profile.

MACS-W:A modified optical clearing agent for imaging 3D cell cultures

Three-dimensional(3D)cell cultures have contributed to a variety of biological research fields by filling the gap between monolayers and animal models.The modern optical sectioning microscopic methods make it possible to probe the complexity of 3D cell cultures but are limited by the inherent opaqueness.While tissue optical clearing methods have emerged as powerful tools for investigating whole-mount tissues in 3D,they often have limitations,such as being too harsh for fragile 3D cell cultures,requiring complex handling protocols,or inducing tissue deformation with shrinkage or expansion.To address this issue,we proposed a modified optical clearing method for 3D cell cultures,called MACS-W,which is simple,highly efficient,and morphology-preserving.In our evaluation of MACS-W,we found that it exhibits excellent clearing capability in just 10 min,with minimal deformation,and helps drug evaluation on tumor spheroids.In summary,MACS-W is a fast,minimally-deformative and fluorescence compatible clearing method that has the potential to be widely used in the studies of 3D cell cultures.

Preface–Introduction to the Special Issue for Chinese-Russian Workshop on Biophotonics and Biomedical Optics

The Chinese-Russian Workshop on Biophotonics and Biomedical Optics 2023 was held online twice on 18–21 September and 25–26 September 2023.The bilateral workshop brought together both Russian and Chinese scientists,engineers,and clinical researchers from a variety of disciplines engaged in applying optical science,photonics,and imaging technologies to problems in biology and medicine.During the workshops,two plenary lectures and twenty invited presentations were presented.This special issue selects some papers from both Russian and Chinese sides,consisting of one review and seven original research articles.

Analysis of alkaline phosphatase and γ-glutamyltransferase after radiofrequency ablation of primary liver cancer: A retrospective study

BACKGROUND Changes in alkaline phosphatase(ALP)andγ-glutamyltransferase(GGT)levels in patients with primary liver cancer(PLC)after radiofrequency ablation(RFA).Hepatocellular carcinoma is a malignant tumor with high incidence worldwide.As a common local treatment,RFA has attracted much attention for its efficacy and influence on liver function.AIM To investigate the effect of serum ALP and GGT levels on the prognosis of patients with PLC treated by RFA.METHODS The preoperative clinical data of 165 patients who were pathologically or clinically diagnosed with PLC and who received RFA in our hospital between October 2018 and June 2023 were collected.The chi-square test was used to compare the data between groups.The Kaplan-Meier method and Cox regression were used to analyze the associ-ations between serum ALP and GGT levels and overall survival,progression-free survival(PFS)and clinical characteristics of patients before treatment.RESULTS The 1-year survival rates of patients with normal(≤135 U/L)and abnormal(>135 U/L)serum ALP before treatment were 91%and 79%,respectively;the 2-year survival rates were 90%and 68%,respectively;and the 5-year survival rates were 35%and 18%,respectively.The difference between the two groups was statistically significant(P=0.01).Before treatment,the 1-year survival rates of patients with normal serum GGT levels(≤45 U/L)and abnormal serum GGT levels(>45 U/L)were 95%and 87%,the 2-year survival rates were 85%and 71%,and the 5-year survival rates were 37%and 21%,respectively.The difference between the two groups was statist-ically significant(P<0.001).Serum ALP[hazard ratio(HR)=1.766,95%confidence interval(95%CI):1.068-2.921,P=0.027]and GGT(HR=2.312,95%CI:1.367-3.912,P=0.002)is closely related to the overall survival of PLC patients after RF ablation and is an independent prognostic factor.The 1-year PFS rates were 72%and 50%,the 2-year PFS rates were 52%and 21%,and the 5-year PFS rates were 14%and 3%,respectively.The difference between the two groups was statistically significant(P<0001).The 1-year PFS rates were 81%and 56%in patients with normal and abnormal serum GGT levels before treatment,respectively;the 2-year PFS rates were 62%and 35%,respectively;and the 5-year PFS rates were 18%and 7%,respectively,with statistical significance between the two groups(P<0.001).The serum ALP concentration(HR=1.653,95%CI:1.001-2.729,P=0.049)and GGT(HR=1.949,95%CI:1.296-2.930,P=0.001)was closely associated with PFS after RFA in patients with PLC.The proportion of male patients with abnormal ALP levels is high,the Child-Pugh grade of liver function is poor,and the incidence of ascites is high.Among GGT-abnormal patients,the Child-Pugh grade of liver function was poor,the tumor stage was late,the proportion of patients with tumors≥5 cm was high,and the incidence of hepatic encephalopathy was high.CONCLUSION Serum ALP and GGT levels before treatment can be used to predict the prognosis of patients with PLC after RFA,and they have certain guiding significance for the long-term survival of patients with PLC after radiofrequency therapy.

Prolonged course of Paxlovid administration in a centenarian with COVID-19:A case report

BACKGROUND According to the population statistics in 2023,there were 110000 people aged over 100 years in China,and the experience of using Paxlovid(nirmatrelvir/ritonavir)for centenarians is particularly valuable.This article reports our experience of using Paxlovid in a centenarian with the novel coronavirus disease 2019(COVID-19)infection.CASE SUMMARY A 103-year-old female with mild COVID-19 and renal insufficiency was given sufficient Paxlovid for 2 days and a half dose for 3 days.During treatment,the patient was complicated with lung infection and heart failure,and nucleic acid remained positive.After expert consultation,a full dose of Paxlovid was given again on the 9th day of admission for 2 days and a half dose for 3 days.Meanwhile,anti-heart failure and antibiotics were administered;the heart failure and pulmonary infection were improved.Finally,on the 33^(th) day of admission,nucleic acid turned negative,body temperature returned to normal,cough and sputum,fatigue,poor appetite and other symptoms basically improved.The patient was given Paxlovid via nasal feeding for 2 courses without deterioration of liver and kidney function,diarrhea,nausea and vomiting,myalgia,chest tightness and other side effects,and was discharged from hospital with good recovery.CONCLUSION This case suggests that Paxlovid can be used cautiously in centenarians with renal insufficiency and two courses of treatment can be considered in patients with persistent positive nucleic acid.

The Relation between Genetic Difference for Parents of Hybrid Rice and Heterosis

Exploring the indica-japonica differentiation in parents of hybridization can provide theoretical bases for utilizing inter-subspecific heterosis. In this study, 5 sterile lines and 18 self-bred restorer lines were used as female parents and male parents respectively. Then 90 combinations were constructed by incomplete diallel cross followed by relationship analysis between parental Cheng’s index difference value and Euclidean distance and heterosis. The results showed a significant correlation between several phenotype values, super male parent heterosis and control heterosis and Euclidean distance or Cheng’s index difference value. However, it was no significant correlation for yield. Further analysis found a common interval, 3.41 - 3.46 for Euclidean distance and 3 - 4 for cheng’s index difference value of parents, which was significant or high significant positive correlated with phenotype value, super male parent and control heterosis of main yield traits. This illustrates that the larger the genetic difference of parents was, the stronger the heterosis combinations were, when the genetic differences of parents were in an appropriate range.

Aberrant expression of COL4A1 in age-related cataract and its effect on cell proliferation,apoptosis and gene expression changes

AIM:To evaluate the regulation of the aberrant expression of collagen typeⅣalpha 1 chain(COL4A1)in the development of age-related cataract(ARC).METHODS:Quantitative reverse transcription-polymerase chain reaction(qRT-PCR)and Western blot analysis were employed to evaluate the expression of COL4A1 in ARC patients and healthy controls.The proliferation,apoptosis,cell cycle and epithelial-mesenchymal transition(EMT)of human lens epithelial cell(HLE-B3)were further analyzed under the condition of COL4A1 gene silence.Alteration of gene expression at mRNA level after knockdown COL4A1 were also evaluated by qRT-PCR on HLE-B3 cells.RESULTS:The aberrant expression of COL4A1 was identified a clinically associated with the ARC.Silencing of COL4A1 promoted the apoptosis and inhibited the proliferation of HLE-B3 by blocking the cell cycle.Moreover,COL4A1 gene silence didn’t affect the cytoskeleton of HLE-B3 but down-regulated the Collagen typeⅣAlpha 2 Chain(COL4A2),paired box 6(PAX6),procollagen-lysine 2-oxoglutarate 5-dioxygenases 1(PLOD1)and procollagenlysine 2-oxoglutarate 5-dioxygenases 2(PLOD2)expression levels in HLE-B3 cells.Silencing the COL4A1 gene induced EMT of the HLE-B3 cells by promoting the transforming growth factor beta(TGF-β)expression.CONCLUSION:Silencing of COL4A1 induces S-phase arrest,also inhibits the proliferation and enhance HLE-B3 apoptosis and EMT,and down-regulates the expression of COL4A2,PAX6,PLOD1 and PLOD2.Thus,the expression alteration of COL4A1 may play a critical role in the pathogenesis of ARC.

Tissue optical clearing for neural regeneration research

Nerve injury,whether traumatic or degenerative,disrupts the transmission of information in the nervous syste m,leading to dysfunction.It is widely known that neural regeneration is vital to the restoration of function after nerve injury.Still,outcomes are often limited by the misguidance of axonal regeneration and complex pathological changes in neurons and glia,as well as the longterm denervation of target organs.

集束化护理在肝癌TACE术后患者疼痛管理中的应用效果

目的:对集束化护理模式应用于肝癌TACE术后患者疼痛管理中的临床效果进行研究探讨。方法:选取于2019年3月-2019年5月进入我院介入导管室进行TACE治疗的肝癌患者72例作为研究对象,依据疼痛管理中护理干预方法的不同对患者进行分组,分别为常规组(常规护理)和观察组(行集束化护理),各36例,对两组患者的临床效果进行对比。结果:术后6 h与12 h评测时两组患者疼痛评分并无明显差异(P>0.05),而在术后24 h、48 h时评测结果显示观察组患者疼痛评分明显更低(P<0.05);干预前两组患者的生活质量各项评分无显著差异(P>0.05);干预后两组患者的生活质量评分各方面均有上升,且观察组患者的各评分较对照组上升更明显(P<0.05)。结论:集束化护理管理在肝癌TACE术后患者疼痛管理中相对常规护理具有更好的临床效果,对于缓解患者术后疼痛以及提升其生活质量等方面价值显著,值得进行推崇。

电子结肠镜检查在儿童下消化道出血中的应用价值

目的探讨电子结肠镜检查在儿童下消化道出血(LGIB)中的临床应用价值和胃镜替代电子结肠镜检查的可行性。方法回顾性分析2017年1月-2020年3月该院消化内科收治的267例LGIB患儿的病历资料,对病因及电子结肠镜检查结果进行归纳总结。结果学龄前儿童占69.29%。儿童LGIB的常见病因为肠道息肉、结直肠炎、炎症性肠病(IBD)、过敏性结肠炎、过敏性紫癜(HSP)和梅克尔憩室。其中,肠道息肉、IBD、嗜酸细胞性胃肠炎、过敏性结肠炎和白塞病的诊断阳性率达100.00%。通过内镜直视下局部止血治疗29例,镜下高频电凝电切治疗肠道息肉100例,均安全有效。267例患儿行电子结肠镜检查268例次,完成全结肠检查234例,总体盲肠插管率为87.31%。其中,电子结肠镜检查227例(盲肠插镜率为90.31%),胃镜代电子结肠镜检查41例(盲肠插镜率为70.73%)。结论电子结肠镜检查在儿童LGIB诊疗中安全有效,不同病因导致的LGIB在电子结肠镜下表现不同,对于1岁以下或体重小于10 kg的患儿,采用胃镜替代电子结肠镜检查安全可行。

人脐带间充质干细胞源外泌体对高糖环境下RPE细胞自噬和VEGF表达的影响

目的:探讨人脐带间充质干细胞(hUMSC)源外泌体对高糖环境下ARPE-19细胞自噬及VEGF表达情况的影响。方法:原代培养hUMSC,分离纯化hUMSC外泌体,Western blot鉴定hUMSC外泌体标志蛋白CD63表达,透射电镜观察外泌体形态。将体外培养的ARPE-19细胞随机分为对照组、高糖组和外泌体+高糖组(75μg/mL外泌体预处理)。培养48h后,电镜观察三组细胞内自噬体的超微结构,MTT法检测各组细胞增殖情况,Western blot检测各组细胞中自噬标志性蛋白LC3B、Beclin-1及p62的表达,ELISA法检测细胞上清液中VEGF的质量浓度。结果:分离纯化后的外泌体为直径30~100nm的球状膜性囊泡,表达特异性标识蛋白CD63。外泌体+高糖组中自噬体的数量明显少于高糖组。外泌体+高糖组的细胞增殖率较高糖组明显升高(P<0.01)。对照组、高糖组、外泌体+高糖组细胞中LC3B-Ⅱ/Ⅰ、Beclin-1和p62值分别为(0.214±0.019、0.461±0.067和0.332±0.079),(0.186±0.029、0.615±0.044和0.464±0.046)和(0.771±0.051、0.364±0.016和0.547±0.039)。高糖组细胞中LC3B-Ⅱ/Ⅰ值和Beclin-1值均明显高于对照组和外泌体+高糖组(均P<0.05),高糖组细胞中p62值明显低于对照组和外泌体+高糖组(均P<0.01),外泌体+高糖组VEGF的质量浓度较高糖组明显降低(P<0.01)。结论:高糖环境激活ARPE-19细胞自噬,并促进其VEGF的表达。hUMSC外泌体可有效抑制高糖环境下ARPE-19细胞自噬水平,并下调VEGF的表达。

The Top of the Biomimetic Triangle

There is increasing observational evidence indicating that crystalline interfacial water layers play a central role in evolution and biology. For instance in cellular recognition processes, in particular during first contact events, where cells decide upon survival or entering apoptosis. Understanding water layers is thus crucial in biomedical engineering, specifically in the design of biomaterials inspired by biomimetic principles. Whereas there is ample experimental evidence for crystalline interfacial water layers on surfaces in air, their subaquatic presence could not be verified directly, so far. Analysing a polarity dependent asym- metry in the surface conductivity on hydrogenated nanocrystalline diamond, we show that crystalline interfacial water layers persist subaquatically. Nanoscopic interfacial water layers with an order different from that of bulk water have been identified at room temperature on both hydrophilic and hydrophobic model surfaces - in air and subaquatically. Their generalization and systematic inclusion into the catalogue of physical and chemical determinants of biocompatibility complete the biomimetic triangle.

Anomalous expression of chloride transporters in the sclerosed hippocampus of mesial temporal lobe epilepsy patients

The Na＋-K＋-CI- cotransporter 1 and K＋-CI- cotransporter 2 regulate the levels of intracellular chloride in hippocampal cells. Impaired chloride transport by these proteins is thought to be involved in the pathophysiological mechanisms of mesial temporal lobe epilepsy. Imbalance in the relative expression of these two proteins can lead to a collapse of CI- homeostasis, resulting in a loss of gamma-aminobutyric acid-ergic inhibition and even epileptiform discharges. In this study, we investigated the expression of Na＋-K＋-CI- cotransporter 1 and K＋-CI- cotransporter 2 in the sclerosed hippocampus of patients with mesial temporal lobe epilepsy, using western blot analysis and immunohistochemistry. Compared with the histologically normal hippocampus, the sclerosed hippocampus showed increased Na＋-K＋-Cl- cotransporter 1 expression and decreased K＋-CI- cotransporter 2 expression, especially in CA2 and the dentate gyrus. The change was more prominent for the Na＋-K＋-CI- cotransporter 1 than for the K＋-CI- cotransporter 2. These experimental findings indicate that the balance between intracellular and extracellular chloride may be disturbed in hippocampal sclerosis, contributing to the hyperexcitability underlying epileptic seizures. Changes in Na＋-K＋-CI-cotransporter 1 expression seems to be the main contributor. Our study may shed new light on possible therapies for patients with mesial temporal lobe epilepsy with hippocampal sclerosis.

Influence of overexpression of SOCS2 on cells of DN rat

Objective: To explore the influence and mechanism of overexpression of SOCS2 on diabetic nephropathy(DN) rats and cells. Methods: STZ was used to induce male SD rats and SOCS2 was injected into left renal vein. Rats were divided into DN group, DN-Ad-null group and DNAd-SOCS2 group. Glucose with high and normal concentration was used to culture HBZY-1 cells and then transfect Ad-SOCS2. HG group, HG-Ad-null group, HG-Ad-SOCS2 group, CG group, CG-Ad-null group, and CG-Ad-SOCS2 group were created. The expression of inflammatory cytokines(MCP-1, TNF-α and IL-6) in kidney tissue of rats, fibrosis related protein(FN, Collagen Ⅳ and TGF-β) in kidney tissue and cells of rats, and JAK/STAT signaling pathway related proteins(p-JAK2 and p-STAT3) were tested by western blot. ELISA was used to test the expression of inflammatory cytokines(TNF-α and IL-6) in cells. Results: The expression of inflammatory cytokines in DN rats(MCP-1, TNF-α and IL-6) and cell(TNF-α and IL-6) were increased(P<0.01) significantly. However, SOCS2 could decrease the overexpression of mediated inflammatory cytokines in DN animal models and cell models(P<0.01). The expression of fibrosis related protein in DN rats and cells increased while SOCS2 decreased the overexpression of mediated fibrosis related protein in DN model rats and cells(P<0.01). The expression of JAK/STAT pathway related protein in both DN rats and cells increased and the JAK/STAT signaling pathway was activated. Yet, SOCS2 obviously suppressed the expression of the JAK/STAT signaling pathway as well as the related proteins(p-JAK2 and p-STAT3) in both DN rats and cells. Conclusions: The overexpression of SOCS2 can decrease the expression of inflammatory cytokines and fibrosis related proteins in DN rats and cells, and meanwhile suppress the activation of JAK/STAT signaling pathway mediated by DN.

Recurrence of sigmoid colon cancer–derived anal metastasis:A case report and review of literature

BACKGROUND Distant metastasis of colorectal cancer to the anus is very rare,with only 30 related cases published in PubMed thus far.Therefore,recurrence of colorectal cancer derived anus metastases is rarely seen and less presented.CASE SUMMARY Here we report an 80-year-old male patient who underwent radical resection for sigmoid colon cancer in January 2010 and another surgery for anal fistula resection in December 2010.Postoperative pathology of the anal fistula revealed a metastatic moderately differentiated adenocarcinoma.The patient subsequently received chemotherapy and radiotherapy.In May 2020,after the patient reported symptoms of anal swelling and pain,computed tomography and magnetic resonance imaging revealed a perianal abscess.Perianal mass biopsy was performed,and the postoperative pathological diagnosis was metastatic moderately differentiated adenocarcinoma.CONCLUSION This case highlights that there is a risk of recurrence of anal metastasis of colorectal cancer even after 10 years of follow-up.We also reviewed the literature and discuss potential mechanisms for anal metastasis of colorectal cancer,thus providing some suggestions for treatment of these cases.

Comparison of ultrasound biomicroscopy and spectraldomain anterior segment optical coherence tomography in evaluation of anterior segment after laser peripheral iridotomy

AIM：To quantitatively assess narrow anterior chamber angle using spectral-domain anterior segment optical coherence tomography（SD-AS-OCT） and ultrasound biomicroscopy（UBM）,and to evaluate the correlations and consistency between SD-AS-OCT and UBM.· METHODS：Fifty-five eyes from 40 patients were examined.Patients were diagnosed with primary angleclosure glaucoma（PACG） remission（11 eyes from 8patients）,primary angle closure（PAC,20 eyes from 20patients） and PAC suspect（24 eyes from 12 patients）.Each eye was examined by SD-AS-OCT and UBM after laser peripheral iridotomy（LPI）.The measurements of SD-AS-OCT were angle open distance（AOD）,anterior chamber angle（ACA）,trabecular iris angle（TIA）,and trabecular iris space area（TISA）.UBM measurements were AOD and TIA.Correlations of AOD500 and TIA500 between UBM and AS-OCT were assessed.All parameters were analysed by SPSS 16.0 and MedCalc.· RESULTS：ACA,TIA and AOD measured by SD-ASOCT reached a maximum at the temporal quadrant and minimum at the nasal quadrant.Group parameters of AOD500 and AOD750 showed a linear positive correlation,and AOD750 had less variability.UBM outcomes of AOD500 and TIA500 were significantly smaller than those of SD-AS-OCT.The results of the two techniques were correlated at the superior,nasal and inferior quadrants.CONCLUSION：Both UBM and SD-AS-OCT are efficient tools for follow-up during the course of PACG.We recommended using parameters at 750 μm anterior to the sclera spur for the screening and follow-up of PACG and PAC.The two methods might be alternatives to each other.

Optical angiography for diabetes-induced pathological changes in microvascular structure and function:An overview

Diabetes mellitus(DM)is a kind of metabolic disorder characterized by chronic hyperglycemia and glucose intolerance due to absolute or relative lack of insulin,leading to chronic damage of vasculature within various organ systems.These detrimental e®ects on the vascular networks will result in the development of various diseases associated with microvascular injury.Modern optical imaging techniques provide essential tools for accurate evaluation of the structural and functional changes of blood vessels down to capillaries level,which can o®er valuable insight on understanding the development of DM-associated complications and design of targeted therapy.This review will brie°y introduce the DM-induced structural and functional alterations of vasculature within di®erent organs such as skin,cerebrum and kidneys,as well as how novel optical imaging techniques facilitate the studies focusing on exploration of these pathological changes of vasculature caused by DM both in-vivo and ex-vivo.

IMPROVE OPTICAL CLEARING OF SKIN IN VITRO WITH PROPYLENE GLYCOL AS A PENETRATION ENHANCER

In order to enhance the optical clearing effect of topically applied optical clearing agents(OCAs),we evaluated the effect of propylene glycol(PG)as a chemical penetration enhancer(PE)on optical clearing of skin in vitro by observation and measurement of optical-transmittance and diffuse-reflectance spectra.Three OCAs,i.e.,glycerol,D-sorbitol and PEG400,and two other penetration enhancers,Azone and Thiazone,were used in this study.The results indicated that the decrease of reduced scattering coefficient caused by OCA/PG was larger than that by pure OCA,and the change by OCA/water was the least after the same treatment time.There were significant differences for the reduced scattering coefficient at 630 nm after 120 min application of agents between OCA and OCA/PG.The efficacy of optical clearing caused by OCA/PG depended on the OCA itself.When PEG400 was mixed with three different PEs,we found the optical clearing were different.The penetration enhancing ability of PG was much better compared to Azone,and suboptimal to Thiazone.Also,this study provides evidence for the use of PG as a PE in order to improve skin optical clearing.