Pulp health and calcific healing of a complicated crown–root fracture with additional root fracture in a maxillary incisor: A case report

BACKGROUND Complicated crown–root fracture (CRF) involves severe injury to the crown, root,and pulp, and may be accompanied by multiple root fractures. The loss of a toothhas lifelong consequences for children and teenagers, but the maintenance of pulphealth and the calcific healing of multiple root fractures are rarely reported in theliterature.CASE SUMMARY This case reports healing of a permanent tooth with complicated crown–root andadditional root fractures, in which pulp health was maintained. A 10-year-old girlfell and fractured the root of her maxillary left central incisor at the cervical level.After the coronal fragment was repositioned, the tooth was splinted until thetooth was no longer mobile, 2 years later. Eight years after treatment, the toothhas remained asymptomatic with vital pulp and localized gingival overgrowth.Cone-beam computed tomography revealed not only calcified healing of the CRFbut also spontaneous healing in an additional undiagnosed root fracture. Thefracture line on the enamel could not be healed by hard tissue and formed agroove in the cervical crown. It was speculated that the groove was related to thelocalized gingival overgrowth.CONCLUSION This case provides a clinical perspective of the treatment of a tooth with acomplicated CRF and an additional root fracture.

Mandibular left first premolar with three roots and three canals:A case report

BACKGROUND The numbers of mandibular first premolar roots and root canals vary,and the incidence of three roots and three canals is 0.09%.CASE SUMMARY In this article,we review the root and root canal conditions for the mandibular first premolar and report the case of a mandibular left first premolar with three roots and three canals in a male patient,with suggestions for clinical diagnosis and treatment.The patient was referred by an orthodontist for the extraction of the tooth.Preoperative cone-beam computed tomography examination revealed that it had three roots.Under local anesthesia,the extraction socket was carefully expanded,and the tooth was successfully removed intact using forceps.The procedure was uneventful,with no root fractures,postoperative bleeding,or sensory abnormality observed.CONCLUSION The mandibular first premolar is characterized by multiple roots and canal variations that can increase the difficulty of treatment.

Review on physiological and ecological characteristics and agronomic regulatory pathways of intercropping to delay root and canopy senescence of crops

Intercropping has been widely used in arid and semi-arid regions because of its high yield,stable productivity,and efficient utilization of resources.However,in recent years,the high yield of traditional intercropping is mainly attributed to the large amount of purchased resources such as water and fertilizer,plastic film,and mechanical power.These lead to a decline in cultivated land quality and exacerbate intercrops'premature root and canopy senescence.So,the application of traditional intercropping faces major challenges in crop production.This paper analyzes the manifestations,occurrence mechanisms,and agronomic regulatory pathways of crop senescence.The physiological and ecological characteristics of intercropping to delay root and canopy senescence of crops are reviewed in this paper.The main agronomic regulatory pathways of intercropping to delay root and canopy senescence of crops are based on above-and blow-ground interactions,including collocation of crop varieties,spatial arrangement,water and fertilizer management,and tillage and mulch practices.Future research fields of intercropping to delay root and canopy senescence should focus on the aspects of selecting and breeding special varieties,application of molecular biology techniques,and developing or applying models to predict and evaluate the root and canopy senescence process of intercrops.Comprehensive analysis and evaluation of different research results could provide a basis for enhancing intercropping delay root and canopy senescence through adopting innovative technologies for regulating the physio-ecological characteristics of intercrops.This would support developing and adopting high-yield,efficient,and sustainable intercropping systems in arid and semi-arid areas with high population density,limited land,and abundant light and heat resources.

ARF4 acting upstream of LBD16 promotes adventitious root formation in peach

Although class A auxin response factors(ARFs)are known to regulate adventitious root(AR)development through the canonical SCFTIR1-Aux/IAA-ARF signaling pathway,the regulatory role of class B ARFs in AR development remains largely unclear.Therefore,this research focused on the role of class B ARF transcription factors in peach(Prunus persica‘Shengli')adventitious root formation.Here,we report the role of a class B ARF gene Pp ARF4 in adventitious root formation in peach.Comparative transcriptome and q RT-PCR analyses showed that the transcription of Pp ARF4 was significantly up-regulated in auxin-treated stem explants.Y2H assay showed that Pp ARF4 had no interaction with Pp IAAs(AUXIN/INDOLE ACETIC ACIDs).Pp ARF4 could bind the promoters of lateral root development gene Pp LBD16 and auxin transport gene Pp PIN1 to activate their transcription.Ectopic overexpression of Pp ARF4 and Pp LBD16 in Arabidopsis promoted AR development.Additionally,Pp ARF4 could act as a negative regulator of flavone synthesis and thus prevent the explants from browning.The results not only provide novel insights into the functions of ARFs in regulating plant growth and development,but will also be useful for fulfilling asexual propagation by stem cuttings in peach.

Nerve root magnetic stimulation regulates the synaptic plasticity of injured spinal cord by ascending sensory pathway

Promoting synaptic plasticity and inducing functional reorganization of residual nerve fibers hold clinical significance for restoring motor function following spinal cord injury.Neuromagnetic stimulation targeting the nerve roots has been shown to improve motor function by enhancing nerve conduction in the injured spinal cord and restoring the synaptic ultrastructure of both the sensory and motor cortex.However,our understanding of the neurophysiological mechanisms by which nerve root magnetic stimulation facilitates motor function recovery in the spinal cord is limited,and its role in neuroplasticity remains unclear.In this study,we established a model of spinal cord injury in adult male Sprague–Dawley rats by applying moderate compression at the T10 vertebra.We then performed magnetic stimulation on the L5 nerve root for 3 weeks,beginning on day 3 post-injury.At day 22 post-injury,we observed that nerve root magnetic stimulation downregulated the level of interleukin-6 in the injured spinal cord tissue of rats.Additionally,this treatment reduced neuronal damage and glial scar formation,and increased the number of neurons in the injured spinal cord.Furthermore,nerve root magnetic stimulation decreased the levels of acetylcholine,norepinephrine,and dopamine,and increased the expression of synaptic plasticity-related m RNA and proteins PSD95,GAP43,and Synapsin II.Taken together,these results showed that nerve root magnetic stimulation alleviated neuronal damage in the injured spinal cord,regulated synaptic plasticity,and suppressed inflammatory responses.These findings provide laboratory evidence for the clinical application of nerve root magnetic stimulation in the treatment of spinal cord injury.

双波长激光联合生物陶瓷材料iRoot SP辅助磨牙根管治疗效果分析

目的:探讨双波长激光联合生物陶瓷材料iRoot SP辅助磨牙根管治疗的效果。方法:选择2020年1月—2023年6月收治的104例磨牙根管治疗患者,按照随机数字表法分为对照组与试验组,每组52例。对照组采用iRoot SP糊剂进行根管充填,试验组以双波长激光(Nd:YAG和Er:YAG)联合iRoot SP糊剂进行治疗。比较2组总有效率、疼痛程度及并发症,观察治疗前、治疗后6周及12周的血清白细胞介素6(IL-6)、白细胞介素17(IL-17)、肿瘤坏死因子α(TNF-α)、出血指数(bleeding index,BI)、牙周探诊深度(depth of periodontal probing,PD)和临床附着水平(clinical attachment level,CAL)。采用SPSS 22.0软件包对数据进行统计学分析。结果:试验组总有效率显著高于对照组,根管填充后疼痛程度显著低于对照组(P<0.05);试验组治疗后6、12周的IL-6、IL-17、TNF-α、BI、PD和CAL显著低于对照组(P<0.05)。结论:双波长激光联合生物陶瓷材料iRoot SP辅助磨牙根管治疗效果较为理想,有利于减轻牙周炎症和疼痛程度。

iRoot SP单尖法根管充填对牙体牙髓病患者的疗效及对疼痛、炎症反应的影响

目的 探讨iRoot SP单尖法根管充填对牙体牙髓病患者的疗效及对疼痛、炎症反应的影响。方法 选取106例牙体牙髓病患者,随机均分为常规组和观察组。常规组采用AHplus根充糊剂填充治疗,观察组采用iRoot SP单尖法根管充填治疗,两组均治疗3个月。比较两组患者根管填充时间、恢复时间、临床疗效、疼痛、炎症反应白细胞介素-6(IL-6)、高敏C反应蛋白(hs-CRP)水平、并发症发生率。结果 观察组患者根管填充时间、恢复时间短于常规组(P<0.05)。观察组总有效率高于常规组(P<0.05)。术后,两组患者IL-6与hs-CRP水平较术前均上升,且观察组低于常规组(P<0.05),观察组疼痛感低于常规组(P<0.05)。观察组并发症发生率低于常规组(P<0.05)。结论 iRoot SP单尖法根管充填治疗牙体牙髓病,能够缩短患者填充时间、恢复时间,提高疗效,降低炎症反应,缓解患者的疼痛感,降低并发症发生率,具有一定的推广价值。

牙体牙髓病根管治疗应用iRoot SP冷侧法的效果

目的探讨牙体牙髓病根管治疗应用iRoot SP冷侧法的效果。方法筛选2018-06至2020-06在解放军总医院京南医疗区就诊的牙体牙髓病患者100例,随机分为对照组和试验组,每组50例,均进行根管治疗,其中对照组充填根管采用热牙胶垂直加压法,试验组采用iRoot SP冷侧法。比较两组根管充填效果、临床总有效率、疼痛视觉模拟评分(VAS)及咀嚼功能。结果两组治疗后根管充填效果和临床总有效率比较,差异无统计学意义(P>0.05);试验组治疗后1周[(4.13±0.79)vs.(5.11±0.98)]及1个月[(2.45±0.37)vs.(3.11±0.67)]VAS评分低于对照组,治疗后咬合力[(131.25±11.21)lbs vs.(120.34±14.09)lbs]及咀嚼效率[(90.12±4.13)%vs.(78.98±7.45)%]均优于对照组,差异均有统计学意义(P<0.05)。结论根管治疗牙体牙髓病中应用iRoot SP冷侧法的充填效果和疗效与热牙胶垂直加压法基本相同,但iRoot SP冷侧法在减轻患者疼痛,改善咀嚼功能方面更具优势。

iRoot SP配合单尖法根管充填治疗逆行性牙髓炎的效果分析

目的分析iRoot SP配合单尖法根管充填治疗逆行性牙髓炎的效果。方法前瞻性研究,选取2022年1月至2023年5月在福建省立医院口腔科治疗的逆行性牙髓炎患者120例作为研究对象,按照随机数字表法分为对照组和观察组,各60例。对照组男35例、女25例,年龄(58.65±4.89)岁,病程(4.12±1.36)年,以iRoot SP配合冷侧方加压法根管充填;观察组男32例、女28例,年龄(59.34±5.27)岁,病程(4.51±1.49)年,以iRoot SP配合单尖法根管充填。对比两组疗效、充填效果、牙周指数[牙周探诊深度(PD)、探诊出血指数(BOP)、牙齿松动度(TM)、临床附着水平(CAL)]及龈沟液炎性因子水平[超敏C反应蛋白(hs-CRP)、肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)]。统计学方法采用t检验、χ^(2)检验。结果观察组治疗总有效率为96.67%(58/60),高于对照组的86.67%(52/60),差异有统计学意义(χ^(2)=3.927,P<0.05)。观察组填充良好率为96.67%(58/60),高于对照组的75.00%(45/60),差异有统计学意义(χ^(2)=11.582,P<0.05)。治疗前,两组患者PD、BOP、TM、CAL及hs-CRP、TNF-α、IL-1β水平比较,差异均无统计学意义(均P>0.05);治疗后,观察组PD、BOP、TM、CAL及hs-CRP、TNF-α、IL-1β水平均低于对照组[(1.97±0.23)mm比(2.76±0.26)mm、(0.84±0.19)分比(1.31±0.23)分、(0.12±0.05)mm比(0.27±0.08)mm、(0.94±0.37)mm比(2.10±0.42)mm、(0.78±0.06)mg/L比(1.03±0.09)mg/L、(0.48±0.09)mg/L比(1.01±0.10)mg/L、(56.68±2.34)ng/L比(63.16±2.57)ng/L],差异均有统计学意义(t=17.628、12.203、12.316、16.053、17.903、30.515、14.441,均P<0.05)。结论iRoot SP配合单尖法根管充填治疗逆行性牙髓炎,根管封闭效果较好,可改善患者牙周状态及龈沟液炎性因子水平,整体疗效显著。

Exogenous melatonin improves cotton yield under drought stress by enhancing root development and reducing root damage

The exogenous application of melatonin by the root drenching method is an effective way to improve crop drought resistance.However,the optimal concentration of melatonin by root drenching and the physiological mechanisms underlying melatonin-induced drought tolerance in cotton(Gossypium hirsutum L.)roots remain elusive.This study determined the optimal concentration of melatonin by root drenching and explored the protective effects of melatonin on cotton roots.The results showed that 50μmol L-1 melatonin was optimal and significantly mitigated the inhibitory effect of drought on cotton seedling growth.Exogenous melatonin promoted root development in drought-stressed cotton plants by remarkably increasing the root length,projected area,surface area,volume,diameter,and biomass.Melatonin also mitigated the drought-weakened photosynthetic capacity of cotton and regulated the endogenous hormone contents by regulating the relative expression levels of hormone-synthesis genes under drought stress.Melatonin-treated cotton seedlings maintained optimal enzymatic and non-enzymatic antioxidant capacities,and produced relatively lower levels of reactive oxygen species and malondialdehyde,thus reducing the drought stress damage to cotton roots(such as mitochondrial damage).Moreover,melatonin alleviated the yield and fiber length declines caused by drought stress.Taken together,these findings show that root drenching with exogenous melatonin increases the cotton yield by enhancing root development and reducing the root damage induced by drought stress.In summary,these results provide a foundation for the application of melatonin in the field by the root drenching method.

Hormonal and epigenetic regulation of root responses to salinity stress

Salinity stress is a major environmental stress affecting crop productivity,and its negative impact on global food security is only going to increase,due to current climate trends.Salinity tolerance was present in wild crop relatives but significantly weakened during domestication.Regaining it back requires a good understanding of molecular mechanisms and traits involved in control of plant ionic and ROS homeostasis.This review summarizes our current knowledge on the role of major plant hormones(auxin,cytokinins,abscisic acid,salicylic acid,and jasmonate)in plants adaptation to soil salinity.We firstly discuss the role of hormones in controlling root tropisms,root growth and architecture(primary root elongation,meristematic activity,lateral root development,and root hairs formation).Hormone-mediated control of uptake and sequestration of key inorganic ions(sodium,potassium,and calcium)is then discussed followed by regulation of cell redox balance and ROS signaling in salt-stressed roots.Finally,the role of epigenetic alterations such as DNA methylation and histone modifications in control of plant ion and ROS homeostasis and signaling is discussed.This data may help develop novel strategies for breeding and cultivating salt-tolerant crops and improving agricultural productivity in saline regions.

A novel pathogen Fusarium cuneirostrum causing common bean(Phaseolus vulgaris)root rot in China

Several fungal pathogens cause root rot of common bean,among which Fusarium spp.are the most common pathogens causing Fusarium root rot(FRR)worldwide.FRR has been becoming an increasingly severe disease of common bean in China,but the species of Fusarium spp.have remained unclear.Thus,this study was performed to identify the pathogen causing common bean root rot in Liangcheng County,Inner Mongolia,China.Nineteen Fusarium-like isolates were obtained after pathogen isolation and purification.The pathogenicity test indicated that eight isolates caused severe disease symptoms on common bean,while 11 other isolates were not pathogenic.The eight pathogenic isolates,FCL1–FCL8,were identified as Fusarium cuneirostrum by morphological characterization and phylogenetic analysis using partial sequences of EF-1α,ITS,28S,and IGS regions.Host range test showed that the representative F.cuneirostrum isolate FCL3 was also pathogenic to mung bean,while not pathogenic to adzuki bean,chickpea,cowpea,faba bean,pea,and soybean.Moreover,50 common bean and 50 mung bean cultivars were screened for resistance to FRR,and seven highly resistant or resistant cultivars of common bean were identified,while no resistant cultivars of mung bean were screened.This study revealed that F.cuneirostrum was one of common bean FRR pathogens in Inner Mongolia and it could induce mung bean root rot as well.To our knowledge,this is the first report of F.cuneirostrum causing FRR of common bean in China.

The response of roots and the rhizosphere environment to integrative cultivation practices in paddy rice

Integrative cultivation practices(ICPs)are essential for enhancing cereal yield and resource use efficiency.However,the effects of ICP on the rhizosphere environment and roots of paddy rice are still poorly understood.In this study,four rice varieties were produced in the field.Each variety was treated with six different cultivation techniques,including zero nitrogen application(0 N),local farmers’practice(LFP),nitrogen reduction(NR),and three progressive ICP techniques comprised of enhanced fertilizer N practice and increased plant density(ICP1),a treatment similar to ICP1 but with alternate wetting and moderate drying instead of continuous flooding(ICP2),and the same practices as ICP2 with the application of organic fertilizer(ICP3).The ICPs had greater grain production and nitrogen use efficiency than the other three methods.Root length,dry weight,root diameter,activity of root oxidation,root bleeding rate,zeatin and zeatin riboside compositions,and total organic acids in root exudates were elevated with the introduction of the successive cultivation practices.ICPs enhanced nitrate nitrogen,the activities of urease and invertase,and the diversity of microbes(bacteria)in rhizosphere and non-rhizosphere soil,while reducing the ammonium nitrogen content.The nutrient contents(ammonium nitrogen,total nitrogen,total potassium,total phosphorus,nitrate,and available phosphorus)and urease activity in rhizosphere soil were reduced in all treatments in comparison with the non-rhizosphere soil,but the invertase activity and bacterial diversity were greater.The main root morphology and physiology,and the ammonium nitrogen contents in rhizosphere soil at the primary stages were closely correlated with grain yield and internal nitrogen use efficiency.These findings suggest that the coordinated enhancement of the root system and the environment of the rhizosphere under integrative cultivation approaches may lead to higher rice production.

The dorsal root ganglion as a target for neurorestoration in neuropathic pain

Neuropathic pain is a severe and chronic condition widely found in the general population.The reason for this is the extensive variety of damage or diseases that can spark this unpleasant constant feeling in patients.During the processing of pain,the dorsal root ganglia constitute an important region where dorsal root ganglion neurons play a crucial role in the transmission and propagation of sensory electrical stimulation.Furthermore,the dorsal root ganglia have recently exhibited a regenerative capacity that should not be neglected in the understanding of the development and resolution of neuropathic pain and in the elucidation of innovative therapies.Here,we will review the complex interplay between cells(satellite glial cells and inflammatory cells)and factors(cytokines,neurotrophic factors and genetic factors)that takes place within the dorsal root ganglia and accounts for the generation of the aberrant excitation of primary sensory neurons occurring in neuropathic pain.More importantly,we will summarize an updated view of the current pharmacologic and nonpharmacologic therapies targeting the dorsal root ganglia for the treatment of neuropathic pain.

Involvement of the ABA-and H_(2)O_(2)-Mediated Ascorbate-Glutathione Cycle in the Drought Stress Responses of Wheat Roots

Abscisic acid(ABA),hydrogen peroxide(H_(2)O_(2)) and ascorbate(AsA)–glutathione(GSH)cycle are widely known for their participation in various stresses.However,the relationship between ABA and H_(2)O_(2) levels and the AsA–GSH cycle under drought stress in wheat has not been studied.In this study,a hydroponic experiment was conducted in wheat seedlings subjected to 15%polyethylene glycol(PEG)6000–induced dehydration.Drought stress caused the rapid accumulation of endogenous ABA and H_(2)O_(2) and significantly decreased the number of root tips compared with the control.The application of ABA significantly increased the number of root tips,whereas the application of H_(2)O_(2) markedly reduced the number of root tips,compared with that under 15%PEG-6000.In addition,drought stress markedly increased the DHA,GSH and GSSG levels,but decreased the AsA levels,AsA/DHA and GSH/GSSG ratios compared with those in the control.The activities of the four enzymes in the AsA–GSH cycle were also markedly increased under drought stress,including glutathione reductase(GR),ascorbate peroxidase(APX),monodehydroascorbate reductase(MDHAR)and dehydroascorbate reductase(DHAR),compared with those in the control.However,the application of an ABA inhibitor significantly inhibited GR,DHAR and APX activities,whereas the application of an H_(2)O_(2) inhibitor significantly inhibited DHAR and MDHAR activities.Furthermore,the application of ABA inhibitor significantly promoted the increases of H_(2)O_(2) and the application of H_(2)O_(2) inhibitor significantly blocked the increases of ABA,compared with those under 15% PEG-6000.Taken together,the results indicated that ABA and H_(2)O_(2) probably interact under drought stress in wheat;and both of them can mediate drought stress by modulating the enzymes in AsA–GSH cycle,where ABA acts as the main regulator of GR,DHAR,and APX activities,and H_(2)O_(2) acts as the main regulator of DHAR and MDHAR activities.

iRoot SP单尖充填技术用于根管再治疗的临床效果

目的探讨iRoot SP单尖充填技术用于根管再治疗的临床效果。方法选取2021年2月至2022年1月于长沙市口腔医院行根管再治疗的96例患者作为研究对象,根据随机数字表法将其分为研究组(n=48)和参考组(n=48)。研究组行iRoot SP单尖充填,参考组行AH-Plus热牙胶垂直加压法充填。比较两组的根管充填效果、单根管填充时间、疼痛程度、疗效、咀嚼功能。结果两组的根管充填效果比较,差异无统计学意义(P>0.05)。研究组的单根管填充时间为(58.88±5.21)s,短于参考组的(92.35±7.24)s,差异有统计学意义(P<0.05)。研究组术后1、7 d的视觉模拟评分法(VAS)评分为(4.28±0.79)分、(2.97±0.35)分,均低于参考组的(6.54±2.02)分、(3.87±1.21)分,差异有统计学意义(P<0.05);两组的疗效及治疗总有效率比较,差异无统计学意义(P>0.05);术后,两组患者的咀嚼效率、咬合力均高于本组术前,且研究组的咀嚼效率、咬合力均高于参考组,差异有统计学意义(P<0.05)。结论根管再治疗使用iRoot SP单尖充填技术可在确保疗效的同时缩短填充时间,减轻患者疼痛,改善咀嚼功能,值得临床推广使用。

生物陶瓷封闭剂nRoot和生物陶瓷牙胶尖的根尖封闭性研究

目的:体外评价国产新型生物陶瓷根管封闭剂nRoot的根尖封闭性以及应用生物陶瓷根管封闭剂时生物陶瓷牙胶尖的根尖封闭性,为临床材料选择提供理论依据。方法:选取单根管的离体前磨牙,自釉牙骨质界处截去牙冠,随机分为四个实验组和两个对照组。通过逐步深入技术进行根管预备,然后采用Martin TroPe推介的生物陶瓷封闭剂改良热牙胶垂直加压充填技术进行根管充填。A组:nRoot根管封闭剂联合生物陶瓷牙胶尖;B组:nRoot根管封闭剂联合普通牙胶尖;C组:iRoot SP根管封闭剂联合生物陶瓷牙胶尖;D组:iRoot SP根管封闭剂联合普通牙胶尖;E组和F组分别为阳性对照组和阴性对照组。通过染料渗透法和扫描电镜法分别观测各组根尖封闭性情况,染料渗透长度越长,微缝隙越宽,表示根尖封闭性越差。结果:染料渗透实验结果显示,A组(2.455±0.137)mm,B组(2.830±0.148)mm,C组(2.426±0.130)mm,D组(2.774±0.163)mm。经方差分析得出,iRoot SP和nRoot差异无统计学意义(P>0.05);生物陶瓷牙胶尖和普通牙胶尖差异有统计学意义(P<0.05),且生物陶瓷牙胶尖染料渗透平均值低于普通牙胶尖;根管封闭剂与牙胶尖交互效应不显著(P>0.05)。扫描电镜结果显示,各组充填材料与牙体组织结合界面均可见大小不等的微缝隙,其中使用普通牙胶尖的B组和D组中,微缝隙较宽,而使用生物陶瓷牙胶尖的A组和C组中,微缝隙相对较小;B组与D组之间,A组与C组之间,微缝隙宽度均没有明显区别。结论:①国产新型生物陶瓷根管封闭剂nRoot具有与进口生物陶瓷根管封闭剂iRoot SP相似的根尖封闭性;②应用生物陶瓷根管封闭剂时,生物陶瓷牙胶尖的根尖封闭性优于普通牙胶尖;③充填材料中根管封闭剂和牙胶尖对根尖封闭性的影响相互独立,互不干扰。

基于Root-MUSIC算法的激光扫频干涉测量方法研究

玻璃的厚度作为工业生产中的一项重要的指标,如何对其快速的测量成为了研究热点。提出采用激光扫频干涉测量方法,将采样的信号进行插值拟合,校正其拍频非线性,再通过频谱估计法获取距离信息。当测量厚度较小的玻璃时,FFT算法因受栅栏效应和频谱干涉的影响,导致难以在频谱图中将玻璃前后表面的频率区分出来。为解决该问题,采用Root-MUSIC算法处理信号,实验结果表明在FFT算法分辨临近目标频率失效的情况下,Root-MUSIC算法可以进行有效区分,运算效率也远高于MUSIC算法,且精度可达50微米左右,为解决玻璃厚度测量问题提供了思路。

iRoot SP单尖法根管充填联合牙周基础治疗糖尿病患者慢性根尖周炎疗效观察

目的:探究iRoot SP单尖法根管充填治疗糖尿病合并慢性根尖周炎患者的疗效及美学效果。方法:选取2020年8月-2022年12月笔者医院收治的120例糖尿病合并慢性根尖周炎患者,采用数字化随机法将其分为观察组和对照组,每组60例。对照组采用AHPlus+热牙胶垂直加压技术充填治疗,观察组采用iRoot SP单尖法根管充填治疗。观察比较两组患者根管充填时间、充填后1 d、3 d、5 d和7 d的疼痛VAS评分,充填前后根尖周指数(Periapical index,PAI)、充填后3个月的临床疗效,充填前后患者红色美学指数评分(Pink esthetic score,PES)和白色美学指数评分(White esthetic score,WES),充填前后患者的菌斑指数(Plaque index,PLI)、牙周袋探诊深度(Probing depth,PD)和龈沟出血指数(Sulcus bleeding index,SBI)。结果:对照组充填单位根管时间较观察组长,充填后1周内观察组患者PAI指数低于对照组,且充填后1 d、3 d、5 d、7 d的VAS评分低于对照组(P<0.05);充填后3个月,观察组的总有效率与对照组相当,差异无统计学意义(P>0.05);充填前,两组患者PES和WES评分比较,差异无统计学意义(P>0.05),充填后3个月,观察组患者PES和WES评分均高于对照组,PLI、PD及SBI均低于对照组(P<0.05)。结论:相较AHPlus+热牙胶垂直加压技术,iRoot SP单尖法充填治疗糖尿病慢性根尖周炎患者的充填效率更高,充填后疼痛感更轻,成功率更高,美学效果更显著,值得临床推广应用。

Evolution history dominantly regulates fine root lifespan in tree species across the world

Understanding the drivers of variations in fine root lifespan is key to informing nutrient cycling and productivity in terrestrial ecosystems.However,the general patterns and determinants of forest fine root lifespan at the global scale are still limited.We compiled a dataset of 421 fine root lifespan observations from 76 tree species globally to assess phylogenetic signals among species,explored relationships between fine root lifespan and biotic and abiotic factors,and quantified the relative importance of phylogeny,root system structure and functions,climatic and edaphic factors in driving global fine root lifespan variations.Overall,fine root lifespan showed a clear phylogenetic signal,with gymnosperms having a longer fine root lifespan than angiosperms.Fine root lifespan was longer for evergreens than deciduous trees.Ectomycorrhizal(ECM)plants had an extended fine root lifespan than arbuscular mycorrhizal(AM)plants.Among different climatic zones,fine root lifespan was the longest in the boreal zone,while it did not vary between the temperate and tropical zone.Fine root lifespan increased with soil depth and root order.Furthermore,the analysis of relative importance indicated that phylogeny was the strongest driver influencing the variation in forest fine root lifespan,followed by soil clay content,root order,mean annual temperature,and soil depth,while other environmental factors and root traits exerted weaker effects.Our results suggest that the global pattern of fine root lifespan in forests is shaped by the interplay of phylogeny,root traits and environmental factors.These findings necessitate accurate representations of tree evolutionary history in earth system models to predict fine root longevity and its responses to global changes.