Bone morphogenetic protein-6 suppresses TGF-β_(2)-induced epithelial-mesenchymal transition in retinal pigment epithelium

AIM:To evaluate the effect of bone morphogenetic protein-6(BMP-6)on transforming growth factor(TGF)-β_(2)-induced epithelial-mesenchymal transition(EMT)in retinal pigment epithelium(RPE).METHODS:Adult retinal pigment epithelial cell line(ARPE-19)were randomly divided into control,TGF-β_(2)(5μg/L),and BMP-6 small interfering RNA(siRNA)group.The cell morphology was observed by microscopy,and the cell migration ability were detected by Transwell chamber.The EMT-related indexes and BMP-6 protein levels were detected by Western blotting.Furthermore,a BMP-6 overexpression plasmid was constructed and RPE cells were divided into the control group,TGF-β_(2)+empty plasmid group,BMP-6 overexpression group,and TGF-β_(2)+BMP-6 overexpression group.The EMT-related indexes and extracellular regulated protein kinases(ERK)protein levels were detected.RESULTS:Compared with the control group,the migration of RPE cells in the TGF-β_(2) group was significantly enhanced.TGF-β_(2) increased the protein expression levels ofα-smooth muscle actin(α-SMA),fibronectin and vimentin but significantly decreased the protein levels of E-cadherin and BMP-6(P<0.05)in RPE.Similarly,the migration of RPE cells in the BMP-6 siRNA group was also significantly enhanced.BMP-6 siRNA increased the protein expression levels ofα-SMA,fibronectin and vimentin but significantly decreased the protein expression levels of E-cadherin(P<0.05).Overexpression of BMP-6 inhibited the migration of RPE cells induced by TGF-β_(2) and prevented TGF-β_(2) from affecting EMT-related biomarkers(P<0.05).CONCLUSION:BMP-6 prevents the EMT in RPE cells induced by TGF-β_(2),which may provide a theoretical basis for the prevention and treatment of proliferative vitreoretinopathy.

Effect of dopamine on bone morphogenesis protein-2 expression in human retinal pigment epithelium

AIM：To investigate the effect of dopamine on bone morphogenesis protein-2（BMP-2）expression in retinal pigment epithelium（RPE）cells in vitro.METHODS：ARPE-19 cells as a human RPE cell line were cultured with dopamine for different times（2,4,6,8,12,16and 24h）or with different concentrations（0.1,1,2,5,10,20,and 100μg/m L）in vitro.BMP-2 m RNA expression level in ARPE-19 cells was analyzed with real-time polymerase chain reaction（PCR）analysis and BMP-2 protein level was measured with Western blot analysis.The active form of BMP-2 in the culture medium was measured with enzymelinked immunosorbent assay（ELISA）.RESULTS：The expression level of BMP-2 increased significantly cultured with 20μg/m L dopamine,at different time points（P〈0.05）.BMP-2 m RNA level peaked 2h and the protein level peaked at 6 and 8h after treatment.The concentrations of secreted BMP-2 elevated at 12h and peaked at 24h（P〈0.05）in a time-dependent manner.Treated with 100μg/m L dopamine for 6h,the expression levels of BMP-2 m RNA and protein in ARPE-19 cells were enhanced significantly compared to that in the untreated cells（P〈0.05）.And secreted BMP-2 protein in the cell culture supernatant was also increased（P〈0.05）.CONCLUSION：Dopamine up-regulate BMP-2 expression in RPE cells,and this may be associated with its inhibitive effect on myopia development.

Decreased uncoupling protein 2 expression in aging retinal pigment epithelial cells

AIM: To analyze the expression of uncoupling protein 2(UCP2) in retinal pigment epithelium(RPE) cells at the different human age, further explore the possible new target of RPE cells protection.METHODS: Adult retinal pigment epithelial-19(ARPE-19) cells and the primary RPE cells at the different age(9-20 y,50-55 y, 60-70 y, >70 y) were cultured and harvested. The expression of UCP2 in these cells was detected by reverse transcription-polymerase chain reaction(RT-PCR), Western blot and confocal microscopy.RESULTS: Cells from the donors more than 60 y are larger and more fibroblastic in appearance compared to ARPE-19 cells and those primary cultures obtained from the younger individuals by using phase-contrast micrographs. Results of RT-PCR, Western blot and confocal microscopy all showed that UCP2 was highly expressed in ARPE-19 cells and in the younger primary cultured human RPE cells at the age of 9-20 y and 50-55 y, whereas lower expression of UCP2 was measured in the older primary cultured human RPE cells at the age more than 60 y.CONCLUSION: Expression of UCP2 gene is decreased in aged RPE cells, promoting the lower ability of anti-oxidation in these cells. It is indicated that UCP2 gene might be a new target for protecting the cells from oxidative stress damage.

Engineering an ultrathin amorphous TiO2 layer for boosting the weatherability of TiO2 pigment with high lightening power

TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and therefore reduce the lightening power of TiO2. In the present work, a uniform, amorphous, 2.9-nm-thick TiO2 protective layer was deposited onto the surface of anatase TiO2 pigments according to pulsed chemical vapor deposition at room temperature, with Ti Cl4 as titanium precursor. Amorphous TiO2 coating layers exhibited poor photocatalytic activity, leading to a boosted weatherability. Similarly, this coating method is also effective for TiO2 coating with amorphous SiO2 and SnO2 layers. However, the lightening power of amorphous TiO2 layer is higher than those of amorphous SiO2 and SnO2 layers. According to the measurements of photoluminescence lifetime, surface photocurrent density, charge-transfer resistance, and electron spin resonance spectroscopy, it is revealed that the amorphous layer can prevent the migration of photogenerated electrons and holes onto the surface, decreasing the densities of surface electron and hole, and thereby suppress the photocatalytic activity.

Age-related maculopathy susceptibility 2 participates in the phagocytosis functions of the retinal pigment epithelium

AIM: Age-related macular degeneration (AMD) is a multifactorial disease and a prevalent cause of visual impairment in developed countries. Many studies suggest that age-related maculopathy susceptibility 2 (ARMS2) is a second major susceptibility gene for AMD. At present, there is no functional information on this gene. Therefore, the purpose of the present study was to detect the expression of ARMS2 in retinal pigment epithelium (RPE) cells and to investigate the effect of ARMS2 on the phagocytosis function of RPE cells. METHODS: Immunofluorescence and reverse transcriptase PCR were used to demonstrate the presence and location of ARMS2 in ARPE-19 (human retinal pigment epithelial cell line, ATCC, catalog No.CRL-2302) cells. siRNA was used to knock down ARMS2 mRNA, and the effects of the knockdown on the phagocytosis function of the ARPE-19 cells were evaluated via Fluorescence Activated Cell Sorting (FACS). RESULTS: ARMS2 was present in ARPE-19 cells, localized in the cytosol of the perinuclear region. The expression of ARMS2 mRNA (messenger RNA) in ARPE-19 cells transfected with ARMS2-siRNA (small interfering RNA, 0.73+/- 0.08) was decreased compared with normal cells (1.00+/- 0.00) or with cells transfected with scrambled siRNA (0.95+/- 0.13) (P<0.05). After incubation of RPE cells with a latex beads medium for 12, 18, or 24 hours, the fluorescence intensities were 38.04 +/- 1.02, 68.92 +/- 0.92, and 78.00 +/- 0.12 in the ARMS2-siRNA-transfected groups, respectively, and 77.98 +/- 5.43, 94.87 +/- 0.60, and 98.30 +/- 0.11 in the scrambled siRNA-transfected groups, respectively. The fluorescent intensities of the same time points in the two groups were compared using Student's t-test, and the p values were all less than 0.001 at the three different time points. CONCLUSION: There is endogenous expression of ARMS2 in ARPE-19 cells. ARMS2 plays a role in the phagocytosis function of RPE cells, and this role may be one of the mechanisms that participates in the development of AMD.

Cross-talk between microRNA-let7c and transforming growth factor-β2 during epithelial-to-mesenchymal transition of retinal pigment epithelial cells

AIM: To explore the roles of microRNA-let7 c(miR-let7 c) and transforming growth factor-β2(TGF-β2) and cellular signaling during epithelial-to-mesenchymal transition(EMT) of retinal pigment epithelial cells. METHODS: Retinal pigment epithelial(ARPE-19) cells were cultured with no serum for 12 h, and then with recombinant human TGF-β2 for different lengths of time. ARPE-19 cells were transfected with 1×106 TU/mL miR-let7 c mimcs(miR-let7 cM), miR-let7 c mimcs negative control(miR-let7cMNC) and miR-let7 c inhibitor(miR-let7 cI) using the transfection reagent. The expression of keratin-18, vimentin, N-cadherin, IKB alpha, p65 were detected by Western blot, quantitative polymerase chain reaction and immunofluorescence. RESULTS: The expression of miR-let7c was dramatically reduced and the nuclear factor-kappa B(NF-κB) signaling pathway was activated after induction by TGF-β2(P<0.05). In turn, overexpressed miR-let7 c significantly inhibited TGF-β2-induced EMT(P<0.05). However, miR-let7 c was unable to inhibit TGF-β2-induced EMT when the NF-κB signaling pathway was inhibited by BAY11-7082(P<0.01). CONCLUSION: The miR-let7 c regulates TGF-β2-induced EMT through the NF-κB signaling pathway in ARPE-19 cells.

Down regulation of UCP2 expression in retinal pigment epithelium cells under oxidative stress: an in vitro study

AIM: To evaluate the expression of uncoupling protein 2(UCP2) in a retinal pigment epithelium cell line(ARPE-19), under oxidative stress(OS).METHODS: ARPE-19 cells were divided into groups treated with various concentrations of hydrogen peroxide(H2 O2;0, 150, 300, 500, 700, and 900 μmol/L) for 24 h, to induce oxidative damage and cell viability was assessed by MTT assay. UCP2 mRNA expression in cells treated with H2 O2 was investigated by reverse transcription-polymerase chain reaction(RT-PCR). UCP2 protein expression was assessed by Western blotting and ROS levels analyzed by flow cytometry(FCM). Further, UCP2-siRNA treated cultures were exposed to H2 O2(0, 75, 150, and 300 μmol/L) for 2 h and cell viability determined by MTT assay.RESULTS: Cells treated with higher concentrations of H2 O2 appeared shrunken;their adhesion to adjacent cells was disrupted, and the number of dead cells increased. The results of cell viability assays demonstrated that the numbers of cells were decreased in a dose-dependent manner following treatment with H2 O2. Compared with untreated controls, cell viability was significantly reduced after treatment with >300 μmol/L H2 O2(P<0.05). Cell metabolic activity was decreased with increased concentrations of H2 O2 as detected by MTT assay. Levels of OS were further decreased in cells treated with UCP2-siRNA compared with those treated with H2 O2 alone(P<0.05). The results of RT-PCR and Western blotting demonstrated that UCP2 expression was reduced in H2 O2-treated groups compared with controls(P<0.05). FCM analysis showed that cell reactive oxygen species(ROS) levels were increased in H2 O2-treated groups and further upregulated by UCP2-si RNA treatment(P<0.05).CONCLUSION: Expression levels of UCP2 are decreased in ARPE-19 cells treated with H2 O2. ROS levels are further increased in cells treated with UCP2-siRNA relative to those treated with H2 O2 alone. UCP2 may have a protective role in ARPE-19 cells during oxidative injury.

滇鸡血藤红色素的提取工艺优化及其抑制COX-2活性研究

目的:研究滇鸡血藤红色素的最佳提取条件,考察其基本性质与环氧化酶-2(COX-2)抑制活性,为滇鸡血藤的临床用药及相关制剂开发提供参考。方法:以吸光度为指标,采用单因素试验和正交试验对滇鸡血藤红色素提取工艺中的液料比、浸提时间、乙醇体积分数进行优化,确定滇鸡血藤红色素的最佳提取工艺,对提取得到的红色素光、热、pH稳定性进行考察,进一步采用COX-2抑制剂筛选试剂盒考察滇鸡血藤红色素对COX-2的抑制作用。结果:在50%乙醇、液料比为110、浸提12 h的条件下提取的滇鸡血藤红色素吸光度最大;其在室温避光、pH 1~9条件下有较好的稳定性;滇鸡血藤红色素对COX-2有较好的抑制作用,半数抑制浓度(IC50)为2.04 ng·mL^(-1)(生药质量浓度)。结论:明确了滇鸡血藤红色素的最佳提取条件和稳定性条件,可为滇鸡血藤资源的综合开发利用与临床用药研究提供参考。

Cytochemical localization of H_2O_2 in pigment glands of cotton(Gossypium hirsutum L.)

Programmed cel death （PCD） plays a critical role in the development of plant pigment glands, while H2O2, which is a kind of reactive oxygen species （ROS） produced by the aerobic metabolism of cels, acts as an important signal in this process. Here, we investigated the temporal and spatial dynamics of accumulated H2O2 in pigment glands ofGossypium hirsutum L. with 3,3-diaminobenzidine （DAB） staining, 2’,7’-dichlorodihydrolfuorescein diacetate （DCFH2）-DA lfuorescent labeling and CeCl3 cytochemical localization techniques. The results showed that thepigment glandsofG. hirsutum could generate H2O2, and the amount and localization of H2O2 variedat different developmental stages. At the early developmental stage, a smal amount of H2O2 accumulated in the vacuole membrane of pigment gland cels. At the intermediate stage, a large number of H2O2 appeared in the vacuole membrane, while cel wals started to accumulate a smal amount of H2O2. When pigment gland cel degraded, H2O2 mainly accumulated on the chloroplast envelope membrane of inner sheath cels. With the degradation of the sheath cels, H2O2was detected in cel wal and the membrane of secretory vesicles which contains the preliminary contents of pigment gland. With the pigment glands completely maturation, H2O2 would disappeared. The accumulation sites of H2O2are consistent with the process of PCD of individual gland cels, which started from the degra-dation of intracelular membrane and ended with the degradation of cel wals. Thus H2O2 probably plays an important role in the development of pigment glands. In addition, the development of pigment glands and the generation of H2O2 are not associated with the light, and no H2O2 was detected in the secretions of pigment glands.

Malarial pigment does not induce MMP-2 and TIMP-2 protein release by human monocytes

Dear editor, In the recent years growing evidence on the involvement of human matrix metalloproteinases(MMPs) and tissue inhibitors of metalloproteinases(TIMPs) in cerebral malaria (CM) has been reported[1]and a role for malarial pigment haemozoin(HZ) has been proposed[2,3].In a recent work my group showed that in human microvascular endothelial

胰岛素样生长因子1对人RPE细胞分泌TGF-β2、MMP-2的影响及机制研究

目的研究胰岛素样生长因子1(IGF-1)对人视网膜色素上皮细胞(ARPE-19)表达转化生长因子β2(TGF-β2)、基质金属蛋白酶2(MMP-2)的影响,并探索其作用机制。方法ARPE-19细胞分别按不同浓度IGF-1和不同浓度LY294002培养6 h、12 h、24 h、48 h,采用CCK-8法检测细胞活力,确定IGF-1、LY294002的最佳作用浓度与时间。细胞划痕法检测细胞迁移活性。ELISA法检测细胞培养上清液中TGF-β2浓度。将ARPE-19细胞分为对照组、IGF-1组(80μg·L^(-1) IGF-1)、IGF-1+LY294002组(80μg·L^(-1) IGF-1+30 mmol·L^(-1) LY294002)、LY294002组(30 mmol·L^(-1) LY294002),使用无血清DMEM/F12培养基培养,对照组不做任何处理,分别采用RT-PCR、Western blot检测细胞中TGF-β2、MMP-2、磷脂酰肌醇-3-激酶(PI3K)、蛋白激酶B(AKT)的mRNA和蛋白表达量。结果与0μg·L^(-1) IGF-1比较,80μg·L^(-1) IGF-1的细胞活力24 h变化显著(P<0.05),故确定其为IGF-1最佳作用浓度和时间。与0 mmol·L^(-1) LY294002比较,24 h的30 mmol·L^(-1) LY294002接近半数抑制浓度,故确定其为LY294002最佳作用时间和浓度。细胞划痕法检测结果显示,0μg·L^(-1) IGF-1组、40μg·L^(-1) IGF-1组、80μg·L^(-1) IGF-1组细胞迁移率整体比较及两两比较差异均有统计学意义(均为P<0.05)。ELISA检测结果显示,0μg·L^(-1) IGF-1组、40μg·L^(-1) IGF-1组、80μg·L^(-1) IGF-1组细胞上清液中TGF-β2浓度整体比较及两两比较差异均有统计学意义(均为P<0.05)。RT-PCR、Western blot检测结果显示,IGF-1、LY294002培养24 h,与对照组比较,IGF-1组细胞中TGF-β2、MMP-2、PI3K、AKT的mRNA与蛋白表达水平均升高,而LY294002组细胞中TGF-β2、MMP-2、PI3K、AKT的mRNA与蛋白表达水平均下降(均为P<0.05);与IGF-1组比较,IGF-1+LY294002组细胞中TGF-β2、MMP-2、PI3K、AKT的mRNA与蛋白表达水平均下降(均为P<0.05)。结论IGF-1能促进ARPE-19细胞增殖、迁移;IGF-1可能通过PI3K/AKT信号通路上调ARPE-19细胞中TGF-β2、MMP-2的表达,参与近视的发生与发展。

Morroniside ameliorates lipopolysaccharide-induced inflammatory damage in iris pigment epithelial cells through inhibition of TLR4/JAK2/STAT3 pathway

AIM:To investigate the effect of morroniside(Mor)on lipopolysaccharide(LPS)-treated iris pigment epithelial cells(IPE).METHODS:IPE cells were induced by LPS and treated with Mor.Cell proliferation was detected by cell counting kit(CCK)-8,apoptosis was detected by flow cytometry,the levels of tumor necrosis factor-α(TNF-α),interleukin(IL)-6,and IL-8 were measured by enzyme-linked immunosorbent assay(ELISA)kits,and the protein expression of TLR4,JAK2,p-JAK2,STAT3,and p-STAT3 was analyzed by Western blotting.In addition,overexpression of TLR4 and Mor treatment of LPS-stimulated IPE cells were also tested for the above indices.RESULTS:Mor effectively promoted the proliferation and inhibited the apoptosis of LPS-treated IPE cells.In addition,Mor significantly reduced the levels of TNF-α,IL-6,and IL-8 and significantly inhibited the expression of TLR4,p-JAK2,and p-STAT3 in LPS-treated IPE cells.The effect of Mor on LPS-treated IPE cells was markedly attenuated after overexpression of TLR4.CONCLUSION:These findings suggest that Mor may ameliorate LPS-induced inflammatory damage and apoptosis in IPE through inhibition of TLR4/JAK2/STAT3 pathway.

Effect of miR-27b-3p and Nrf2 in human retinal pigment epithelial cell induced by high-glucose

AIM:To determine whether the microRNA-27b-3p(miR-27b-3p)/NF-E2-related factor 2(Nrf2)pathway plays a role in human retinal pigment epithelial(hRPE)cell response to high glucose,how miR-27b-3p and Nrf2 expression are regulated,and whether this pathway could be specifically targeted.METHODS:hRPE cells were cultured in normal glucose or high glucose for 1,3,or 6d before measuring cellular proliferation rates using cell counting kit-8 and reactive oxygen species(ROS)levels using a dihydroethidium kit.miR-27b-3p,Nrf2,NAD(P)H quinone oxidoreductase 1(NQO1)and heme oxygenase-1(HO-1)mRNA and protein levels were analyzed using reverse transcription quantitative polymerase chain reaction(RT-qPCR)and immunocytofluorescence(ICF),respectively.Western blot analyses were performed to determine nuclear and total Nrf2 protein levels.Nrf2,NQO1,and HO-1 expression levels by RT-qPCR,ICF,or Western blot were further tested after miR-27b-3p overexpression or inhibitor lentiviral transfection.Finally,the expression level of those target genes was analyzed after treating hRPE cells with pyridoxamine.RESULTS:Persistent exposure to high glucose gradually suppressed hRPE Nrf2,NQO1,and HO-1 mRNA and protein levels and increased miR-27b-3p mRNA levels.High glucose also promoted ROS release and inhibited cellular proliferation.Nrf2,NQO1,and HO-1 mRNA levels decreased after miR-27b-3p overexpression and,conversely,both mRNA and protein levels increased after expressing a miR-27b-3p inhibitor.After treating hRPE cells exposed to high glucose with pyridoxamine,ROS levels tended to decreased,proliferation rate increased,Nrf2,NQO1,and HO-1 mRNA and protein levels were upregulated,and miR-27b-3p mRNA levels were suppressed.CONCLUSION:Nrf2 is a downstream target of miR-27b-3p.Furthermore,the miR-27b-3p inhibitor pyridoxamine can alleviate high glucose injury by regulating the miR-27b-3p/Nrf2 axis.

Periorbital Post-Inflammatory Hyperpigmentation after Fractionated CO₂Laser Resurfacing in Asians

Background: Most data on laser resurfacing have come from studies of people with Fitzpatrick skin types 1 - 3;however, the world’s population is comprised mostly of Fitzpatrick skin types 4 - 6, which are more susceptible to post-inflammatory hyperpigmentation (PIH). Objective: For the purpose of expanding the expertise of plastic surgeons treating patients with darker skin types, this study examined the incidence of PIH in Asians who underwent laser resurfacing, including a histologic arm on fractional ablative resurfacing. Methods & Materials: The clinical study included six subjects of Vietnamese origin who underwent single-depth fractionated CO2 laser resurfacing. The histologic study involved a seventh subject. The MiXto SX&reg;laser with a new scanning handpiece was used, along with magnifying loupes to assess ablative depth after each of three laser passes performed. Photographs were taken at various postoperative intervals. Results: All six clinical subjects showed cosmetic improvement in skin texture and tone with no post-inflammatory hyperpigmentation. In the histologic study, H&E stained sections revealed uniform diathermy. Conclusion: It is possible to significantly reduce PIH in darker skinned subjects through use of a new scanning handpiece and a technique using loupes to assess the depth of ablative resurfacing. The histologic study confirms these findings.

硅灰石与金红石型TiO_(2)颗粒复合及其颜料性能

对通过干法研磨方式进行硅灰石和金红石型TiO_(2)(R-TiO_(2))颗粒复合及其颜料性能和颗粒微观结构进行了研究,对所制备复合颜料性能、结构和复合作用性质进行了表征。结果表明,硅灰石/R-TiO_(2)复合颜料具有和钛白粉相当的颜料性能,含TiO_(2)40%复合颜料遮盖力为14.04g/m^(2),达到纯TiO_(2)的90.10%;硅灰石/R-TiO_(2)复合颜料对紫外线吸收强烈,并与R-TiO_(2)一致。硅灰石/R-TiO_(2)复合颜料以TiO_(2)在硅灰石表面均匀、牢固包覆为特征所形成,硅灰石与TiO_(2)通过颗粒表面脱羟基反应实现结合。

Regulatory factors of Nrf2 in age-related macular degeneration pathogenesis

Age-related macular degeneration(AMD)is a complicated disease that causes irreversible visual impairment.Increasing evidences pointed retinal pigment epithelia(RPE)cells as the decisive cell involved in the progress of AMD,and the function of anti-oxidant capacity of PRE plays a fundamental physiological role.Nuclear factor erythroid 2 related factor 2(Nrf2)is a significant transcription factor in the cellular anti-oxidant system as it regulates the expression of multiple anti-oxidative genes.Its functions of protecting RPE cells against oxidative stress(OS)and ensuing physiological changes,including inflammation,mitochondrial damage and autophagy dysregulation,have already been elucidated.Understanding the roles of upstream regulators of Nrf2 could provide further insight to the OS-mediated AMD pathogenesis.For the first time,this review summarized the reported upstream regulators of Nrf2 in AMD pathogenesis,including proteins and miRNAs,and their underlying molecular mechanisms,which may help to find potential targets via regulating the Nrf2 pathway in the future research and further discuss the existing Nrf2 regulators proved to be beneficial in preventing AMD.

狗牯脑2号茶树红茶适制性研究

【目的】探明狗牯脑2号茶树品种的红茶适制性,为狗牯脑茶树资源开发利用和丰富地方茶产品种类提供技术支撑。【方法】以遂川种植的福鼎大白为对照,遂川本地自育的狗牯脑2号、狗牯脑群体种为试验对象,进行红茶适制性研究,对比分析各茶树品种红茶制品的理化成分、茶色素含量和感官品质。【结果】狗牯脑2号和狗牯脑群体种红茶制品的水浸出物含量分别为35.48%与39.78%,游离氨基酸含量分别为3.19%与2.91%,均显著高于福鼎大白;狗牯脑群体种和福鼎大白红茶制品的茶多酚和咖啡碱含量较高,显著高于狗牯脑2号。红茶制品的茶色素(茶黄素、茶红素和茶褐素)含量方面,狗牯脑2号和狗牯脑群体种略优于福鼎大白。红茶制品综合感官品质评分狗牯脑2号为92.30分,狗牯脑群体种为91.05分,均明显高于福鼎大白。【结论】狗牯脑2号和狗牯脑群体种均适制红茶,尤其以狗牯脑2号红茶品质更优,整体呈汤色橙红明亮、滋味浓强醇厚、香气清鲜甜韵的特点。结合遂川红茶加工工艺技术,在加工过程中适度提高干燥温度、延长干燥时间有利于提高红茶关键香气物质含量,提升红茶品质。

Fe_(2)O_(3)@SiO_(2)纳米颗粒掺杂比例对合成火欧泊颜色性质的影响

宝石级欧泊具有彩虹般绚丽的变彩效应,是其微观尺度上尺寸均一的二氧化硅纳米颗粒有序堆积形成的三维周期结构造成^([1])。欧泊的这一性质,使其成为天然光子晶体的经典案例。因此,合成欧泊不仅可以用作宝石材料,而且其在光子学、光电子学和传感器等领域也具有潜在的应用,越来越多的研究者对合成欧泊产生了兴趣^([2])。在种类繁多的欧泊中,带有变彩效应的火欧泊因同时具有绚丽的结构色和黄-橙-红的体色而备受推崇。以往的一些研究认为分散于火欧泊内部的Fe_(2)O_(3)纳米颗粒是引起其体色的主要原因之一,随着Fe_(2)O_(3)纳米颗粒浓度增加,火欧泊体色逐渐加深^([3])。此外,Fe_(2)O_(3)纳米颗粒的存在相当于在蛋白石结构中引入缺陷,其浓度增加会改变火欧泊的周期性介电结构,最终导致颜色变化。想要验证并进一步研究上述现象,合成一系列不同Fe_(2)O_(3)纳米颗粒掺杂比例的火欧泊进行表征是较理想的策略。Fe_(2)O_(3)纳米颗粒是一种着色能力强、应用范围广的红色无机颜料[4]。然而,有关通过掺杂Fe_(2)O_(3)纳米颗粒合成火欧泊的研究报道较少,这可能是由于Fe_(2)O_(3)纳米颗粒的性质不稳定所致。例如,裸露的Fe_(2)O_(3)纳米颗粒在其分散体系中容易团聚、在高温下可以被还原为Fe_(3)O_(4)并使颜色变为暗红色,环境污染或光照还会导致Fe_(2)O_(3)纳米颗粒颜色褪色等[5]。以上这些问题可以通过将Fe_(2)O_(3)纳米颗粒封装在SiO_(2)外壳中来解决。这是由于SiO_(2)外壳可以调节Fe_(2)O_(3)颗粒之间的距离并防止分散颗粒团聚,SiO_(2)外壳良好的化学惰性还可以增强Fe_(2)O_(3)纳米颗粒内核的化学稳定性,进而确保合成火欧泊的颜色稳定性^([6])。综上所述,为加深对变彩火欧泊颜色成因的认识以及为火欧泊合成技术提供新思路,本研究以Fe_(2)O_(3)内核和SiO_(2)外壳构成的核壳结构纳米颗粒(Fe_(2)O_(3)@SiO_(2))为红色颜料,合成了一系列不同掺杂比例的火欧泊薄膜并对其进行表征。首先,采用溶胶-凝胶法制备SiO_(2)、Fe_(2)O_(3)@SiO_(2)纳米颗粒;然后,将不同体积分数的Fe_(2)O_(3)@SiO_(2)纳米颗粒混合在分散良好且尺寸相近的SiO_(2)纳米颗粒悬浮液中;最后,采用垂直沉积自组装法合成火欧泊薄膜。我们研究了相同厚度情况下不同Fe_(2)O_(3)@SiO_(2)纳米粒子掺杂比例合成的火欧泊薄膜的纳米尺度结构和颜色演变,并与现有研究进行比较。结果表明,与掺杂裸Fe_(2)O_(3)颗粒的蛋白石薄膜相比,Fe_(2)O_(3)@SiO_(2)掺杂火欧泊体色的饱和度和亮度都有所提高,这主要归功于Fe_(2)O_(3)@SiO_(2)在欧泊薄膜中的分布更为均匀且引起的结构性缺陷更少。在结构色方面,暂未发现Fe_(2)O_(3)@SiO_(2)的掺杂对结构色色相的影响,但掺杂比例对结构色强度存在影响。在厚度相同的情况下,结构色强度随着掺杂比例的增加而先下降后升高并最终超过纯SiO_(2)欧泊薄膜的结构色强度。目前的实验研究表明,Fe_(2)O_(3)@SiO_(2)纳米颗粒作为合成火欧泊的掺杂颜料可有效提升火欧颜色性质,本研究的下一阶段将结合数值模拟对Fe_(2)O_(3)@SiO_(2)影响火欧泊结构色强度的物理机制进行探究,为Fe_(2)O_(3)@SiO_(2)用作合成火欧泊的掺杂颜料提供理论支撑。

CO_(2)点阵激光联合湿润烧伤膏治疗面部色素沉着的临床观察

目的探讨CO_(2)点阵激光联合湿润烧伤膏治疗面部色素沉着的临床效果及安全性。方法选取河南整形美容医院2021年10月至2023年10月收治65例面部色素沉着患者,依据治疗方式不同分为对照组(n=33)、观察组(n=32)。对照组接受CO_(2)点阵激光治疗,观察组接受CO_(2)点阵激光联合湿润烧伤膏,两组均治疗至创面愈合。比较两组面部色素沉着评分、皮肤性质评分、生活质量评分、氧化应激指标、不良反应等。结果治疗后两组面部色素沉着评分、皮肤性质评分均比治疗前高,且观察组比对照组更高;治疗后两组生活质量评分均比治疗前高,且观察组比对照组更高;治疗后两组血清丙二醛、过氧化脂质水平均比治疗前低,且观察组比对照组更低,血清超氧化物歧化酶均比治疗前高,且观察组比对照组高;观察组治疗期间不良反应总发生率比对照组更低,上述数据差异均有统计学意义(P<0.05)。结论CO_(2)点阵激光联合湿润烧伤膏可改善面部色素沉着患者皮肤性质,促进色素沉着恢复,调节氧化应激指标水平,提高患者生活质量,安全性较高。

超临界CO_2流体技术精制栀子黄色素的研究

以市售栀子黄色素为原料，比较系统地探讨了超临界状态下萃取压力、温度、时间、ＣＯ２ 流量、夹带剂对栀子黄色素ＯＤ值比率的影响。结果表明：高温、高压、添加夹带剂的条件下有利于降低栀子黄色素的ＯＤ值比率，达到精制的目的。