Er,Cr:YSGG激光切割对牙体与充填物粘结力影响的研究

本文用 1千牛电液疲劳实验机检测充填材料与牙面之间的粘结力 ,发现 :在牙釉质组中 ,酸蚀组、6瓦激光切割组及 6瓦激光切割联合酸蚀组抗剪切粘结强度无显著性差异 (P >0 .0 5) ;在牙本质组中 ,酸蚀组、4瓦激光切割组及 4瓦激光切割联合酸蚀组抗剪切粘结强度也无显著性差异 (P >0 .0 5)。并通过SEM观察激光处理后牙体表面结构的变化 ,发现激光切割后牙釉质表面不平呈层状 ,无玷污层 ,釉柱未见破坏 ;牙本质小管开放 ,表面无玷污层 ,达到酸蚀的效果。因此Er,Cr :YSGG激光切割牙体硬组织具有传统钻切割与酸蚀刻的联合作用 ,可以代替传统的酸蚀方法。     

Er,Cr:YSGG激光处理正常及龋坏牙本质的扫描电镜观察

目的：利用扫描电镜观察Er,Cr：YSGG激光处理龋坏牙本质的形态学改变,并与常规方法进行比较。方法：将24颗新拔除的患龋牙随机分成2组,每组12颗牙。第1组常规处理组：分别用金刚砂石针、碳钢裂钻和挖器处理正常及龋坏牙本质;第2组激光处理组：分别用2WEr,Cr：YSGG激光、4WEr,Cr：YSGG激光处理正常及龋坏牙本质。常规制片,扫描电镜下观察。结果：与常规方法相比,激光处理后的牙本质表面不平,呈鱼鳞状、片状的粗糙外观;表面清洁,无玷污层,牙本质小管口清晰可见;4W激光作用时偶见微裂;激光处理后的牙本质表面具有增加树脂黏结性的形态学改变．结论：Er,Cr：YSGG激光能有效地清除龋坏牙本质及玷污层,并可使牙体组织发生一定的形态学改变。因此,Er,Cr：YSGG激光能够替代常规去龋备洞方法。     

Er,Cr:YSGG激光照射对牙周病牙根面的影响

目的:观察不同能量输出的Er,C r:YSGG激光照射对牙周病牙根面的影响,探讨Er,C r:YSGG激光用于牙周治疗的可行性和有效性。方法:选择因牙周病松动Ⅲo而拔除牙12颗,随机分3组,每组4颗。分别以1.5 W、2.0 W、2.5 W激光照射。扫描电镜(SEM)观察各组牙根表面和纵剖面。结果:低倍镜下各组根面改变无明显差异,表面干净,粗糙程度均匀,未见明显弹坑状痕迹;高倍镜下1.5 W激光照射组显示根面粗糙程度更均匀一致,无弹坑状改变,无熔融、炭化迹象,未见牙本质小管暴露。结论:Er,C r:YSGG激光能有效去除牙周病牙根面玷污层及病变牙骨质,根面无熔融、炭化等改变。1.5 W激光照射组优于2.0 W组和2.5 W组。     

Er,Cr:YSGG激光照射对牙根尖封闭效果影响的实验研究

目的:深入探讨在根尖倒充填术中Er,Cr:YSGG激光照射对牙根尖的封闭效果,为此激光在口腔临床上的应用与推广提供重要的理论与实验依据。方法:将56颗新拔除的单根牙随机分成7组,每组8颗牙。去除牙冠,常规进行根管预备、根管充填。将倒充填的牙根尖进行预备,然后银汞合金倒充填。预备方法:1手机切除根尖后,制备成烧瓶状洞形;2手机处理方法同1,然后Er,Cr:YSGG激光于不同能量(1W、2W)及不同方式(喷水或无水)下对洞内壁进行照射。结合微渗漏检测与扫描电镜观察对Er,Cr:YSGG激光照射后的牙根尖封闭效果进行评估。结果:Er,Cr:YSGG激光可有效去除根切面上的玷污层及碎屑;与手机加银汞倒充填组相比,激光照射后的根尖染料微渗漏深度有所减少;但只有1WEr,Cr:YSGG激光于无水条件下照射时,根尖染料微渗漏深度显著减少(P<0.05)。结论:Er,Cr:YSGG激光应用于根尖倒充填术中可减少微渗漏的发生;促进根尖封闭;在特定的能量参数下可获得优于常规银汞倒充填术的治疗效果。因此我们推荐临床上将Er,Cr:YSGG激光照射与常规银汞倒充填术结合使用,这将有助于提高根尖倒充填术治疗的成功率。     

Er,Cr:YSGG激光照射对根管封闭效果影响的实验研究

探讨常规根管预备后使用不同能量参数Er,C r:YSGG激光进行根管内照射对根管封闭效果的影响,为此激光在根管治疗领域的临床应用提供重要的实验依据。选择新拔除的单根管牙80颗,分成4组,每组20颗牙。常规根管预备后,分别使用1 W、2 W、3 W Er,C r:YSGG激光于有水条件下进行根管内照射,另选一组不做任何处理,作为阴性对照。扫描电子显微镜下观察根管内壁形态学改变后,常规根管充填,检测根管微渗漏情况。采用单因素方差分析及q检验进行统计学处理。结果可见:(1)形态学观察:与对照组相比,激光照射均可有效去除根管内壁的玷污层及碎屑;牙本质小管口清晰可见;未见熔融及炭化等热损伤改变;其中3 W激光处理后根管内壁形态最为理想。(2)微渗漏检测:与对照组相比,各激光组根管微渗漏深度均显著减少(P<0.05);但各激光组间比较无显著性差异(P>0.05)。综上,使用Er,C r:YSGG激光进行根管内照射可达到较为理想的根管清洁目的,显著改善根管充填后的封闭效果,因此有望在临床上应用提高根管治疗的成功率。     

Nd：YAP激光的不同功率和时间组合对亚心形扁藻的影响

采用同一剂量不同功率和时间组合的Nd:YAP激光(波长1 341nm)辐照亚心形扁藻,辐照组分为8W 69 s、10 W 55 s和12 W 46 s三个组合,通过藻细胞生长速率和叶绿素含量测定研究激光对扁藻的影响.实验结果表明,即使同一照射剂量,不同的辐照时间与辐照功率的组合,辐照效果仍不相同,本实验中以辐照时间55 s,辐照功率10 W 为最佳组合.     

不同施磷水平对香蕉产量与品质影响初报

在定量施用氮、钾肥条件下,采用单因素田间试验方法研究不同施磷水平对香蕉产量与品质影响。结果表明,在土壤速效磷含量适宜的香蕉园,株施尿素0.87 kg、氯化钾1.335 kg、有机肥2.0 kg、硫酸镁125.0 g、0.2%硼砂溶液喷1次,以施过磷酸钙1.165 kg/株,N∶P2O5∶K2O=1∶0.35∶2,田间蕉株生长较快、假茎较粗,采收时功能叶片数较多、采收期较早且较短,产量较高;同时,果实外观和内质较好,果指较长较粗、淀粉和总糖含量、可食率略高、可滴定酸居中;经济效益最佳,净利润达2 637.6元/667m2,投入产出比为1∶1.83。     

Nd:YAG激光联合Icon渗透树脂治疗氟斑牙患者效果及对美学效果的影响

摘要 目的：探讨Nd:YAG激光联合Icon渗透树脂治疗氟斑牙患者效果及对美学效果的影响。方法：选择2018年6月至2023年6月来我院诊治的氟斑牙患者80例,共有486颗患牙,根据随机数字表法将80例患者分为两组,对照组行Nd:YAG激光治疗,观察组行Nd:YAG激光联合Icon渗透树脂治疗。对比两组不同时间点的色阶变化情况、漂白疗效、病损面积比、患牙牙釉质硬度,对比治疗过程中两组患者的牙齿敏感度及患者满意度。结果：治疗后即刻、治疗后12周,两组的色阶降低,且同时间点观察组与对照组相比较低（P<0.05）。治疗后即刻,观察组有效率84.17%明显较对照组76.42%高（P<0.05）,治疗后12周,观察组有效94.17%明显较对照组82.93%高（P<0.05）。治疗后即刻、12周两组的病损面积比降低,且同时间点观察组与对照组相比较低（P<0.05）。与治疗前及观察组相比,对照组治疗后即刻、12周时的患牙牙釉质硬度较低（P<0.05）。观察组的牙齿敏感度、满意度明显优于对照组（P<0.05）。结论：Nd:YAG激光联合Icon渗透树脂可提高氟斑牙患牙的疗效,缩小病损面积比、患牙敏感度,提高美学效果,且不影响患牙牙釉质硬度,其是氟斑牙具有潜能的治疗方法。     

蛋白聚糖在维持牙本质胶原空间形貌和水合性能方面的作用

目的:评价牙本质蛋白聚糖对脱矿牙本质胶原纤维形貌和水合性能的影响。方法:新鲜拔除无龋坏人磨牙牙本质酸蚀后分别用胰蛋白酶和硫酸软骨素酶ABC孵育去除牙本质蛋白聚糖和糖胺聚糖侧链,对照组与实验组处理方法相同,但孵育液中不添加酶。然后在牙本质表面不同润湿状态下用场发射扫描电镜和激光共聚焦扫描电镜分别观察牙本质的微观形貌并评价脱矿牙本质的水合性能。结果:硫酸软骨素酶ABC和TRY酶处理改变了牙本质的微观形貌,使胶原纤维间距增大。酶处理、牙本质表面润湿性及两者的交互作用均会显著影响脱矿牙本质的厚度(P0.0001)。结论:牙本质蛋白聚糖和糖胺聚糖侧链在维持牙本质胶原纤维网的空间结构和水合作用方面均发挥着重要作用。蛋白聚糖、胶原纤维-蛋白聚糖以及蛋白聚糖-蛋白聚糖间的的亲水性是影响脱矿牙本质围观形貌和厚度的重要因素。     

The Effect of Calcium Sodium Phosphosilicate on Dentin Hypersensitivity: A Systematic Review and Meta-Analysis

Objective

To investigate the effect of calcium sodium phosphosilicate (CSPS) in treating dentin hypersensitivity (DH) and to compare this effect to that of a negative (placebo) control.

Materials and Methods

Several databases, including Medline, EMBASE, Web of Science, The Cochrane Library, and the Chinese Biomedical Literature Database, were searched to identify relevant articles published through January 2015; grey literature (i.e., academic literature that is not formally published) was also searched. Two authors performed data extraction independently and jointly using data collection forms. The primary outcome was the DH pain response to routine activities or to thermal, tactile, evaporative, or electrical stimuli, and the secondary outcome was the side effects of CSPS use. Each study was evaluated using the Cochrane Collaboration tool for assessing risk bias. Meta-analysis of studies with the same participant demographics, interventions, controls, assessment methods and follow-up periods was performed. The Grading of Recommendations Assessment Development and Evaluation System was used to assess the quality of the evidence and the risk of bias across studies.

Results

Meta-analysis demonstrated that toothpaste containing 5% CSPS was more effective than the negative control at relieving dentin sensitivity, with the level of evidence classified as “moderate”. In addition, prophylaxis paste containing 15% calcium sodium phosphosilicate was favored over the negative control at reducing post-periodontal therapy hypersensitivity, with the level of evidence categorized as “low”. Only two studies reported side effects of CSPS use.

Conclusions

The majority of studies found that calcium sodium phosphosilicate was more effective than the negative control at alleviating DH. Because strong evidence is scarce, high-quality, well-designed clinical trials are required in the future before definitive recommendations can be made.     

Combining Site Occupancy,Breeding Population Sizes and Reproductive Success to Calculate Time-Averaged Reproductive Output of Different Habitat Types: An Application to Tricolored Blackbirds

In metapopulations in which habitat patches vary in quality and occupancy it can be complicated to calculate the net time-averaged contribution to reproduction of particular populations. Surprisingly, few indices have been proposed for this purpose. We combined occupancy, abundance, frequency of occurrence, and reproductive success to determine the net value of different sites through time and applied this method to a bird of conservation concern. The Tricolored Blackbird (Agelaius tricolor) has experienced large population declines, is the most colonial songbird in North America, is largely confined to California, and breeds itinerantly in multiple habitat types. It has had chronically low reproductive success in recent years. Although young produced per nest have previously been compared across habitats, no study has simultaneously considered site occupancy and reproductive success. Combining occupancy, abundance, frequency of occurrence, reproductive success and nest failure rate we found that that large colonies in grain fields fail frequently because of nest destruction due to harvest prior to fledging. Consequently, net time-averaged reproductive output is low compared to colonies in non-native Himalayan blackberry or thistles, and native stinging nettles. Cattail marshes have intermediate reproductive output, but their reproductive output might be improved by active management. Harvest of grain-field colonies necessitates either promoting delay of harvest or creating alternative, more secure nesting habitats. Stinging nettle and marsh colonies offer the main potential sources for restoration or native habitat creation. From 2005–2011 breeding site occupancy declined 3x faster than new breeding colonies were formed, indicating a rapid decline in occupancy. Total abundance showed a similar decline. Causes of variation in the value for reproduction of nesting substrates and factors behind continuing population declines merit urgent investigation. The method we employ should be useful in other metapopulation studies for calculating time-averaged reproductive output for different sites.     

海拔梯度对高原湿地植物形态和生理学效应研究

研究了纳帕海高原湿地4种常见的多年生水生植物经移栽至不同海拔后,在生长过程中的生长状况、叶绿素、可溶性糖、游离脯氨酸（Pro）含量、过氧化物酶（POD）活性的变化及其生理特性。结果表明,水葱（Scirpusvalidus）、荸荠（Heleocharis dulcis）、黑三棱（Sparganium stoloniferum）和茭草（Zizania latifolia）的生长状况随着海拔的降低均有所改善,其中,4种湿地植物的株高随海拔的降低均有所升高,水葱和荸荠的茎粗随海拔的降低均呈现增粗的趋势,黑三棱和茭草的叶片宽度也随海拔的降低有所增加;4种湿地植物的叶绿素（a＋b）含量随着海拔的降低均呈现不断下降的趋势;4种植物的可溶性糖和游离脯氨酸（Pro）含量随海拔的降低均有所下降;荸荠、黑三棱和茭草的过氧化物酶（POD）活性随海拔的降低均呈下降趋势,而水葱的过氧化物酶（POD）活性随着海拔的降低无显著变化,黑三棱和茭草的过氧化物酶（POD）活性显著高于其它两种植物。可见,4种湿地植物的形态、生理特征对不同海拔生境的适应方式可能是通过多种途径实现的,如形态特征、光合作用、抗寒物质代谢、抗氧化酶系统等随海拔梯度的变化而变化。这些不同的适应方式在不同的植物间既有共同规律,又有着各自的特性。     

Effect of Bi3+ addition on the upconversion luminescence properties of NaYbF4:Er

In this study, Bi³⁺ incorporation in NaYbF₄:Er lattice and its influence on upconversion luminescence properties have been investigated in detail using techniques such as temperature‐dependent luminescence, Fourier transform infrared spectroscopy and X‐ray diffraction (XRD). The study was carried out to develop phosphors with improved upconversion luminescence. From photoluminescence and lifetime measurements it is inferred that luminescence intensity from NaYbF₄:Er increases with Bi³⁺ addition. The sample containing 50 at.% Bi³⁺ ions exhibited optimum upconversion luminescence. Increased distance between Yb³⁺–Yb³⁺ and Er³⁺–Er³⁺ due to Bi³⁺ incorporation into the lattice and associated decrease in the extent of dipolar interaction/self‐quenching are responsible for increase in lifetime values and luminescence intensities from Er³⁺ ions. Incorporation of Bi³⁺ into NaYbF₄:Er lattice reduced self‐quenching among Yb³⁺–Yb³⁺ions and this facilitated energy transfer from Yb³⁺ to Er³⁺. This situation also explains decrease in the extent of temperature‐assisted quenching of emission from thermally coupled ²H_11/2 and ⁴S_3/2 levels of Er³⁺. Based on Rietveld refinement of XRD patterns it was confirmed that a maximum of 10 at.% of Bi³⁺added was incorporated into the NaYbF₄:Er lattice and the remaining complex co‐exists as a BiOF phase. These results are of significant interest in the area of development of phosphors based on Yb³⁺–Er³⁺ upconversion luminescence.     

Effect of Gibberellic Acid on Dark and Light Germination at Different Temperatures of Calluna, Ledum andRhododendron Seeds

The aim of the experiments was to study the effects of gibberellic acid (GAs) on the germination of Calluna vulgaris L., Ledum palustre L. and Rhododendron lapponicum (L.) Wahlenb. seeds under different environmental conditions. Under continuous light from white fluorescense tubes (3000 lux), untreated seeds of Calluna were partly dormant at all temperatures studied (9, 15, 21, 27, 27/9, 8/16 hours). Percentage of dormant seeds increased, however, with decreasing temperature, and it varied also from seed lot to seed lot. Untreated seeds of Ledum were dormant in light at 9° and 15°C but not at higher temperatures. Untreated seeds of Rhododendron were completely dormant in light at temperatures from 13° to 24°C. Seeds of all species were completely dormant in darkness both at 15° and 27°C. GA₃ stimulated greatly the germination of all species under all studied environmental conditions. The used concentrations (0.2–3.2 mM) gave nearly 100% germination in most cases. At 9°C the dormancy in some seed lots of Calluna and Ledum was only partly broken by the used concentrations of GA₃.     

不同场强下IRE的肿瘤消融作用及对抗肿瘤免疫的影响

目的:探讨不同电场强度的不可逆电穿孔(IRE)对于肿瘤的消融效果以及其所引起的肿瘤免疫反应。方法:将B16黑色素瘤细胞接种于C57小鼠,制作黑色素瘤小鼠模型,应用不可逆电穿孔仪对肿瘤进行消融,通过测量肿瘤生长大小研究不同场强下的消融效果。通过CD4、CD8a免疫组化染色初步了解不同场强激发的免疫反应的强弱,从而选择最佳消融参数。结果:随着电场强度增加,肿瘤消融效果逐渐趋于理想,然而平板电极夹之间过高电场引发的热效应则不利于后续抗肿瘤免疫反应的激活。选择合适的电场,通过增加电击组数可以达到良好的治疗效果。结论:IRE对肿瘤的消融优势在于它能够很好的激活机体的抗肿瘤免疫反应,因此,选择合适的电场增加电击组数可以起到很好的抗肿瘤作用,具有很好的应用前景。