牙周组织再生术联合无托槽隐形矫治对牙周炎患者龈沟液炎症因子的影响

目的探讨牙周组织再生术(PTR)联合无托槽隐形矫治对牙周炎患者龈沟液炎症因子的影响,为该类患者的治疗提供参考。方法选取2017年3月至2019年3月我院收治的120例牙周炎患者为研究对象,依据随机数字表分为再隐组和再直组,每组60例。再隐组患者给予PTR联合无托槽隐形矫治,再直组患者给予PTR联合直丝弓矫治。比较两组患者龈沟液炎症因子[白介素6(IL-6)、C反应蛋白(CRP)、肿瘤坏死因子α(TNF-α)]水平、牙周健康状况[牙周探诊深度(PD)、牙龈指数(GI)、龈沟出血指数(SBI)、牙菌斑指数(PLI)、临床附着丧失(CAL)]、治疗疗效和并发症情况。结果再隐组和再直组患者治疗后龈沟液IL-6、CRP、TNF-α水平及PD、GI、SBI、PLI、CAL明显低于治疗前,再隐组患者治疗后龈沟液IL-6、CRP、TNF-α水平及PD、GI、SBI、PLI、CAL明显低于再直组,差异均有统计学意义(均P0.05)。再隐组患者治疗有效率为95.00%,明显高于再直组的80.00%,差异有统计学意义(χ~2=6.171,P=0.013)。再隐组患者并发症发生率为5.00%,明显低于再直组的16.67%,差异有统计学意义(χ~2=4.227,P=0.040)。结论 PTR联合无托槽隐形矫治可有效改善牙周炎患者龈沟液炎症因子水平及牙周健康状况,有利于提高疗效和减少并发症,值得临床推广。     

无托槽隐形矫治器与固定矫治器对牙周病正畸治疗患者龈下菌群、龈沟液炎症因子和氧化应激的影响

摘要 目的：对比固定矫治器与无托槽隐形矫治器对牙周病正畸治疗患者龈沟液炎症因子、龈下菌群和氧化应激的影响。方法：选取2016年1月～2021年10月于河北省眼科医院口腔正畸科接受正畸治疗的112例牙周病患者,根据矫治器的不同分为对照组（固定矫治器,n=54）和实验组（无托槽隐形矫治器,n=58）。对比两组牙周健康指标、龈下菌群、龈沟液炎症因子、氧化应激指标和疼痛评分的变化情况。结果：两组矫治10个月后牙龈指数、菌斑指数、龈沟出血指数、牙周探诊深度下降,且实验组低于对照组（P<0.05）。实验组矫治10个月后牙龈卟啉单胞菌（Pg）、具核梭杆菌（Fn）、福塞斯坦氏菌（Tf）和中间型普里沃菌（Pi）含量低于对照组（P<0.05）。两组矫治10个月后肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）、白细胞介素1β（IL-1β）下降,且实验组低于对照组（P<0.05）。两组矫治10个月后丙二醛（MDA）、活性氧（ROS）水平下降,且实验组低于对照组;超氧化物歧化酶（SOD）升高,且实验组高于对照组（P<0.05）。两组矫治1 d、7 d后疼痛视觉模拟评分（VAS）评分升高后下降,且实验组低于对照组（P<0.05）。结论：无托槽隐形矫治器与固定矫治器对牙周病正畸治疗患者均有较好的疗效,其中无托槽隐形矫治器在改善牙周健康指标、龈下菌群、龈沟液炎症因子和氧化应激等方面的效果较为显著。     

Characterised and Projected Costs of Nonindigenous Species in Canada

Biological invasions by nonindigenous species (NIS) can have adverse effects on economically important goods and services, and sometimes result in an ‘invisible tax’ on natural resources (e.g. reduced yield). The combined economic costs of NIS may be significant, with implications for environmental policy and resource management; yet economic impact assessments are rare at a national scale. Impacts of nuisance NIS may be direct (e.g. loss of hardwood trees) or indirect (e.g. alteration of ecosystem services provided by growing hardwoods). Moreover, costs associated with these effects may be accrued to resources and services with clear ‘market’ values (e.g. crop production) and to those with more ambiguous, ‘non-market’ values (e.g. aesthetic value of intact forest). We characterised and projected economic costs associated with nuisance NIS in Canada, through a combination of case-studies and an empirical model derived from 21 identified effects of 16 NIS. Despite a severe dearth of available data, characterised costs associated with ten NIS in Canadian fisheries, agriculture and forestry totalled $187 million Canadian (CDN) per year. These costs were dwarfed by the ‘invisible tax’ projected for sixteen nuisance NIS found in Canada, which was estimated at between $13.3 and $34.5 billion CDN per year. Canada remains highly vulnerable to new nuisance NIS, but available manpower and financial resources appear insufficient to deal with this problem. An erratum to this article is available at .     

Sexual and lifetime selection on body size in a marine fish: the importance of life-history trade-offs

Many field measurements of viability and sexual selection on body size indicate that large size is favoured. However, life-history theory predicts that body size may be optimized and that patterns of selection may often be stabilizing rather than directional. One reason for this discrepancy may be that field estimates of selection tend to focus on limited components of fitness and may not fully measure life-history trade-offs. We use an 8-year, demographic field study to examine both sexual selection and lifetime selection on body size of a coral reef fish (the bicolour damselfish, Stegastes partitus). Selection via reproductive success of adults was very strong (standardized selection differential=1.04). However, this effect was balanced by trade-offs between large adult size and reduced cumulative survival during the juvenile phase. When we measured lifetime fitness (net reproductive rate), selection was strongly stabilizing and only weakly directional, consistent with predictions from life-history theory.     

PHENOTYPIC SELECTION IN AN ARTIFICIAL POPULATION OF IMPATIENS PALLIDA: THE IMPORTANCE OF THE INVISIBLE FRACTION

Multiple-regression techniques for measuring phenotypic selection have been used in a large number of recent field studies. One benefit of this technique is its ability to discern the direct action of selection on traits by removing effects of correlated traits. However, covariation among traits expressed at different stages in an organism's life history is often poorly estimated because individuals that die before reaching adulthood cannot be measured as adults. Accurate estimates of trait covariances are necessary for the correct interpretation of the direct action of selection on a trait. If phenotypic characters expressed at different life-history stages are of interest, and mortality occurs between stages, the components of the selection model will be biased by not including those individuals that died (the “invisible fraction”).     

Viability selection prior to trait expression is an essential component of natural selection

Natural selection operates throughout the life cycle of an organism. Correlative studies typically fail to consider the effects of viability selection prior to trait expression. A 3-year field experiment on the wildflower Mimulus guttatus demonstrates that this unmeasured component of selection can be very strong. As in previous studies, we find that fecundity is positively related to flower size. However, survival to flowering is much lower in large-flowered genotypes than in small-flowered genotypes. Aggregating viability and fecundity, lifetime fitness through female function generally favoured smaller flowered genotypes. This result differs from the great majority of field studies, which suggest strong positive selection on flower size. It has important cautionary implications for studies of natural and sexual selection on adult characters generally, in both plants and animals.     

无托槽隐形矫治技术矫治重度牙周炎伴咬合紊乱患者的临床牙周指标及疗效分析

摘要 目的：探讨与分析无托槽隐形矫治技术对重度牙周炎伴咬合紊乱患者临床牙周指标的影响。方法：选择2019年1月到2021年5月在本院诊治的重度牙周炎伴咬合紊乱患者90例作为研究对象,根据简单分配原则把患者分为隐形组与传统组各45例。传统组给予传统直丝弓固定矫治技术治疗,隐形组给予无托槽隐形矫治技术治疗,两组都治疗观察6个月。在矫治前及矫治6个月后观察牙周指标,并检测龈沟液中细胞因子含量。结果：治疗后隐形组的总有效率为97.8 %,与传统组的84.4 %相比显著提高（P<0.05）。治疗后两组的临床牙周指数都明显低于治疗前,隐形组与传统组相比也显著降低（P<0.05）。两组治疗后的血清IL-1β与TNF-α含量明显低于治疗前,隐形组与传统组相比也明显降低（P<0.05）。治疗期间隐形组的牙龈萎缩、牙周粘连、牙根吸收、牙釉脱矿等并发症发生率为6.7 %,明显低于传统组的24.4 %（P<0.05）。结论：无托槽隐形矫治技术早期矫治重度牙周炎伴咬合紊乱能抑制龈沟液炎症因子的表达,能改善牙龈指数与菌斑指数,提高疗效,减少并发症。     

Interpreting local visual features as a global shape requires awareness

How the brain constructs a coherent representation of the environment from noisy visual input remains poorly understood. Here, we explored whether awareness of the stimulus plays a role in the integration of local features into a representation of global shape. Participants were primed with a shape defined either by position or orientation cues, and performed a shape-discrimination task on a subsequently presented probe shape. Crucially, the probe could either be defined by the same or different cues as the prime, which allowed us to distinguish the effect of priming by local features and global shape. We found a robust priming benefit for visible primes, with response times being faster when the probe and prime were the same shape, regardless of the defining cue. However, rendering the prime invisible uncovered a dissociation: position-defined primes produced behavioural benefit only for probes of the same cue type. Surprisingly, orientation-defined primes afforded an enhancement only for probes of the opposite cue. In further experiments, we showed that the effect of priming was confined to retinotopic coordinates and that there was no priming effect by invisible orientation cues in an orientation-discrimination task. This explains the absence of priming by the same cue in our shape-discrimination task. In summary, our findings show that while in the absence of awareness orientation signals can recruit retinotopic circuits (e.g. intrinsic lateral connections), conscious processing is necessary to interpret local features as global shape.     

The Invisible Hand of Natural Selection, and Vice Versa

Building on work by Popper, Schweber, Nozick, Sober, and others in a still-growing literature, I explore here the conceptual kinship (not the hackneyed ideological association) between Adam Smith's 'invisible hand' and Darwinian natural selection. I review the historical ties, and examine Ullman-Margalit's 'constraints' on invisible-hand accounts, which I later re-apply to natural selection, bringing home the close relationship. These theories share a 'parent' principle, itself neither biological no politico-economic, that collective order and well-being can emerge parsimoniously from the dispersed (inter)action of individuals. The invisible hand operates on 'memes' the way natural selection operates on genes. Like Darwin's concept, it brings together traditional opposites, 'nature' and 'selection,' forming a saltation-mitigating transition between biological instinct and full-blown conscious design. Herschel's criterion of confirmation, which Darwin long strove to satisfy, is itself an invisible hand-like meme – a 'Midas effect' revealing and rewarding the fittest theories, Darwin's and Smith's emphatically among them.