Telleman G, Raghoebar GM, Vissink A, den Hartog L, Huddleston Slater JJR, Meijer HJA. A systematic review of the prognosis of short (<10 mm) dental implants placed in the partially edentulous ...patient. J Clin Periodontol 2011; doi: 10.1111/j.1600‐051X.2011.01736.x.
Aim: This study evaluated, through a systematic review of the literature, the estimated implant survival rate of short (<10 mm) dental implants installed in partially edentulous patients.
Materials and methods: A systematic search was conducted in the electronic databases of MEDLINE (1980–October 2009) and EMBASE (1980–October 2009) to identify eligible studies. Two reviewers independently assessed the methodological quality of the articles using specific study design‐related quality assessment forms.
Results: Twenty‐nine methodologically acceptable studies were selected. A total of 2611 short implants (lengths 5–9.5 mm) were analysed. An increase in implant length was associated with an increase in implant survival (from 93.1% to 98.6%). Heterogeneity between studies was explored by subgroup analyses. The cumulative estimated failure rate of studies performed in the maxilla was 0.010 implants/year, compared with 0.003 found in the studies in the mandible. For studies that also included smokers, the failure rate was 0.008 compared with 0.004 found in studies that excluded smokers. Surface topography and augmentation procedure were not sources of heterogeneity.
Conclusion: There is fair evidence that short (<10 mm) implants can be placed successfully in the partially edentulous patient, although with a tendency towards an increasing survival rate per implant length, and the prognosis may be better in the mandible of non smoking patients.
Measurements of OH, HO2, complex RO2 (alkene- and aromatic-related RO2) and total RO2 radicals taken during the integrated Study of AIR Pollution PROcesses in Beijing (AIRPRO) campaign in central ...Beijing in the summer of 2017, alongside observations of OH reactivity, are presented. The concentrations of radicals were elevated, with OH reaching up to 2.8×107moleculecm-3, HO2 peaking at 1×109moleculecm-3 and the total RO2 concentration reaching 5.5×109moleculecm-3. OH reactivity (k(OH)) peaked at 89 s-1 during the night, with a minimum during the afternoon of ≈22s-1 on average. An experimental budget analysis, in which the rates of production and destruction of the radicals are compared, highlighted that although the sources and sinks of OH were balanced under high NO concentrations, the OH sinks exceeded the known sources (by 15 ppbvh-1) under the very low NO conditions (<0.5ppbv) experienced in the afternoons, demonstrating a missing OH source consistent with previous studies under high volatile organic compound (VOC) emissions and low NO loadings. Under the highest NO mixing ratios (104 ppbv), the HO2 production rate exceeded the rate of destruction by ≈50ppbvh-1, whilst the rate of destruction of total RO2 exceeded the production by the same rate, indicating that the net propagation rate of RO2 to HO2 may be substantially slower than assumed. If just 10 % of the RO2 radicals propagate to HO2 upon reaction with NO, the HO2 and RO2 budgets could be closed at high NO, but at low NO this lower RO2 to HO2 propagation rate revealed a missing RO2 sink that was similar in magnitude to the missing OH source. A detailed box model that incorporated the latest Master Chemical Mechanism (MCM3.3.1) reproduced the observed OH concentrations well but over-predicted the observed HO2 under low concentrations of NO (<1ppbv) and under-predicted RO2 (both the complex RO2 fraction and other RO2 types which we classify as simple RO2) most significantly at the highest NO concentrations. The model also under-predicted the observed k(OH) consistently by ≈10s-1 across all NOx levels, highlighting that the good agreement for OH was fortuitous due to a cancellation of missing OH source and sink terms in its budget. Including heterogeneous loss of HO2 to aerosol surfaces did reduce the modelled HO2 concentrations in line with the observations but only at NO mixing ratios <0.3ppbv. The inclusion of Cl atoms, formed from the photolysis of nitryl chloride, enhanced the modelled RO2 concentration on several mornings when the Cl atom concentration was calculated to exceed 1×104atomscm-3 and could reconcile the modelled and measured RO2 concentrations at these times. However, on other mornings, when the Cl atom concentration was lower, large under-predictions in total RO2 remained. Furthermore, the inclusion of Cl atom chemistry did not enhance the modelled RO2 beyond the first few hours after sunrise and so was unable to resolve the modelled under-prediction in RO2 observed at other times of the day. Model scenarios, in which missing VOC reactivity was included as an additional reaction that converted OH to RO2, highlighted that the modelled OH, HO2 and RO2 concentrations were sensitive to the choice of RO2 product. The level of modelled to measured agreement for HO2 and RO2 (both complex and simple) could be improved if the missing OH reactivity formed a larger RO2 species that was able to undergo reaction with NO, followed by isomerisation reactions reforming other RO2 species, before eventually generating HO2. In this work an α-pinene-derived RO2 species was used as an example. In this simulation, consistent with the experimental budget analysis, the model underestimated the observed OH, indicating a missing OH source. The model uncertainty, with regards to the types of RO2 species present and the radicals they form upon reaction with NO (HO2 directly or another RO2 species), leads to over an order of magnitude less O3 production calculated from the predicted peroxy radicals than calculated from the observed peroxy radicals at the highest NO concentrations. This demonstrates the rate at which the larger RO2 species propagate to HO2, to another RO2 or indeed to OH needs to be understood to accurately simulate the rate of ozone production in environments such as Beijing, where large multifunctional VOCs are likely present.
Isoprene-derived secondary organic aerosol (iSOA) is a significant
contributor to organic carbon (OC) in some forested regions, such as
tropical rainforests and the Southeastern US. However, its ...contribution to
organic aerosol in urban areas that have high levels of anthropogenic
pollutants is poorly understood. In this study, we examined the formation of
anthropogenically influenced iSOA during summer in Beijing, China. Local
isoprene emissions and high levels of anthropogenic pollutants, in
particular NOx and particulate SO42-, led to the formation of
iSOA under both high- and low-NO oxidation conditions, with significant
heterogeneous transformations of isoprene-derived oxidation products to
particulate organosulfates (OSs) and nitrooxy-organosulfates (NOSs).
Ultra-high-performance liquid chromatography coupled to high-resolution mass
spectrometry was combined with a rapid automated data processing technique
to quantify 31 proposed iSOA tracers in offline PM2.5 filter
extracts. The co-elution of the inorganic ions in the extracts caused matrix
effects that impacted two authentic standards differently. The average
concentration of iSOA OSs and NOSs was 82.5 ng m−3, which was around 3 times
higher than the observed concentrations of their oxygenated precursors
(2-methyltetrols and 2-methylglyceric acid). OS formation was dependant on
both photochemistry and the sulfate available for reactive uptake, as shown by a
strong correlation with the product of ozone (O3) and particulate
sulfate (SO42-). A greater proportion of high-NO OS products were
observed in Beijing compared with previous studies in less polluted
environments. The iSOA-derived OSs and NOSs represented 0.62 %
of the oxidized organic aerosol measured by aerosol mass spectrometry on average, but
this increased to ∼3 % on certain days. These results
indicate for the first time that iSOA formation in urban Beijing is strongly
controlled by anthropogenic emissions and results in extensive conversion to
OS products from heterogenous reactions.
Linear poly(p‐phenylene)s are modestly active UV photocatalysts for hydrogen production in the presence of a sacrificial electron donor. Introduction of planarized fluorene, carbazole, ...dibenzob,dthiophene or dibenzob,dthiophene sulfone units greatly enhances the H2 evolution rate. The most active dibenzob,dthiophene sulfone co‐polymer has a UV photocatalytic activity that rivals TiO2, but is much more active under visible light. The dibenzob,dthiophene sulfone co‐polymer has an apparent quantum yield of 2.3 % at 420 nm, as compared to 0.1 % for platinized commercial pristine carbon nitride.
Boosting H2 production: Introduction of planarized fluorene, carbazole, dibenzob,dthiophene, or dibenzob,dthiophene sulfone units in linear poly(p‐phenylene)s greatly enhances the H2 evolution rate. The most active dibenzob,dthiophene sulfone co‐polymer has a UV photocatalytic activity that rivals TiO2, but is much more active under visible light.
Osteoporotic vertebral compression fractures frequently result in significant morbidity and health care resource use. For patients with severe and disabling pain, vertebral augmentation ...(vertebroplasty and kyphoplasty) is often considered. Although vertebroplasty was introduced >30 years ago, there are conflicting opinions regarding the role of these procedures in the treatment of osteoporotic vertebral compression fractures. This review article updates clinicians on the published prospective randomized controlled data, including the most recent positive trials that followed initial negative trials in 2009. Analysis of multiple national claim datasets has also provided further insight into the utility of these procedures. Finally, we considered the recent recommendations of national organizations and medical societies that advise on the use of vertebral augmentation procedures for osteoporotic vertebral compression fractures.
Current materials used for in vitro 3D cell culture are often limited by their poor similarity to human tissue, batch-to-batch variability and complexity of composition and manufacture. Here, we ...present a “blank slate” culture environment based on a self-assembling peptide gel free from matrix motifs. The gel can be customised by incorporating matrix components selected to match the target tissue, with independent control of mechanical properties. Therefore the matrix components are restricted to those specifically added, or those synthesised by encapsulated cells. The flexible 3D culture platform provides full control over biochemical and physical properties, allowing the impact of biochemical composition and tissue mechanics to be separately evaluated in vitro. Here, we demonstrate that the peptide gels support the growth of a range of cells including human induced pluripotent stem cells and human cancer cell lines. Furthermore, we present proof-of-concept that the peptide gels can be used to build disease-relevant models. Controlling the peptide gelator concentration allows peptide gel stiffness to be matched to normal breast (<1 kPa) or breast tumour tissue (>1 kPa), with higher stiffness favouring the viability of breast cancer cells over normal breast cells. In parallel, the peptide gels may be modified with matrix components relevant to human breast, such as collagen I and hyaluronan. The choice and concentration of these additions affect the size, shape and organisation of breast epithelial cell structures formed in co-culture with fibroblasts. This system therefore provides a means of unravelling the individual influences of matrix, mechanical properties and cell-cell interactions in cancer and other diseases.
•We propose an optimised self-assembling peptide gel for defined 3D cell culture.•Peptide gels support growth of multiple cell types, including stromal co-culture.•Gels allow independent control of matrix stiffness and ECM functionalisation.•Stiffness, ECM and stromal cells affect growth of breast cancer progression models.•We show proof-of-concept utilising peptide gels to build disease-relevant models.
The impact of emissions of volatile organic compounds (VOCs) to the
atmosphere on the production of secondary pollutants, such as ozone and
secondary organic aerosol (SOA), is mediated by the ...concentration of nitric
oxide (NO). Polluted urban atmospheres are typically considered to be
“high-NO” environments, while remote regions such as rainforests, with
minimal anthropogenic influences, are considered to be “low NO”. However,
our observations from central Beijing show that this simplistic separation
of regimes is flawed. Despite being in one of the largest megacities in the
world, we observe formation of gas- and aerosol-phase oxidation products
usually associated with low-NO “rainforest-like” atmospheric oxidation
pathways during the afternoon, caused by extreme suppression of NO
concentrations at this time. Box model calculations suggest that during
the morning high-NO chemistry predominates (95 %) but in the afternoon
low-NO chemistry plays a greater role (30 %). Current emissions
inventories are applied in the GEOS-Chem model which shows that such models,
when run at the regional scale, fail to accurately predict such an extreme
diurnal cycle in the NO concentration. With increasing global emphasis on
reducing air pollution, it is crucial for the modelling tools used to
develop urban air quality policy to be able to accurately represent such
extreme diurnal variations in NO to accurately predict the formation of
pollutants such as SOA and ozone.
Introduction
Lymphedema can be a debilitating condition, causing a great decrease in a person’s quality of life (QoL). Treatment with lymphaticovenular anastomosis (LVA), in which an anastomosis is ...created between the lymphatic and venous system, may attenuate lymphedema symptoms and reduce swelling. In this study, we share the results using LVA to treat breast cancer-related lymphedema (BCRL) at our institution.
Materials and methods
Patients were eligible for inclusion if they suffered from unilateral BCRL, if functional lymphatics were available, if compression therapy was used for at least 6 months, and if the follow-up was 12 months at minimum. Lymph vessel functionality was assessed preoperatively using indocyanine green (ICG). During surgery, 1–3 anastomoses were created and shunt patency was confirmed using ICG. Arm volumes were measured before surgery and at 6- and 12-month follow-up. QoL was measured before surgery and at 6-month follow-up. Arm volume differences between the healthy arm and affected arm were compared between the time points.
Results
Twenty-nine consecutive female patients with unilateral BCRL were included. The preoperative mean difference in arm volumes was 701 ± 435 ml (36.9%). This was reduced to 496 ± 302 ml (24.7%) at 6-month follow-up (
p
=
0.00). At 12-month follow-up, the mean difference in arm volume was 467 ± 303 ml (23.5%) (
p
=
0.02). The overall perceived QoL was increased from 5.8 ± 1.1 to 7.4 ± 0.7 (
p
=
0.00). The functionality score decreased from 2.2 to 1.8 (
p
=
0.00), the appearance score decreased from 2.6 to 1.9 (
p
=
0.00), the symptoms score decreased from 2.8 to 1.8 (
p
=
0.00), and the mood score decreased from 2.7 to 1.5 (
p
=
0.00). Fifteen patients (53.6%) were able to discontinue the use of compression garment.
Conclusion
Treatment with LVAs is effective in reducing arm volume difference in patients suffering from BCRL. Although no complete reduction of the edema was achieved at 12-month follow-up, the procedure significantly increased the patients’ QoL.
There is an emergent literature highlighting the positive role of social support and social identification in buffering against the deleterious effects of psychological stressors. Yet, we have ...limited understanding of how exactly these social factors fit within contemporary stress and coping theory. To advance and gain a greater understanding of these social factors, we explore the associations of social support and social identification on individuals' challenge and threat cognitive appraisals and how this then relates to perceived stress, life satisfaction, turnover intentions, and job performance. A total of 412 workplace employees from private and public sector occupations completed state measures around a recent most stressful experience at work. Results revealed atemporal associations between cognitive resource appraisals with both social support and social identification. Specifically, greater identification with colleagues and lower threat were related to less perceived stress, while having greater social identification (with colleagues and organisation), social support, and lower threat, were related to greater life satisfaction. Greater perceived stress, and lower social identification and life satisfaction, were also related to greater turnover intentions. While greater identification with the organisation and life satisfaction, along with lower perceived stress were related to greater job performance. Taken together, this research provides evidence that social support and social identification play a positive role when trying to promote more adaptive responses to stressful situations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Significance Many of the most diverse lineages of animals and plants are hypothesized to have arisen via the process of adaptive radiation. Most modern definitions of adaptive radiation focus on the ...role of ecological opportunity in regulating rates of morphological diversification. Using the rich fossil record of North American canids (wolves, foxes, and their relatives), I found no relationship between past diversity and rates of body size or tooth shape evolution. Instead, phenotypic evolution is directed toward adaptively optimal morphologies, such as large size or broad molars, without changes in the rate at which diversity accumulates. If these kinds of processes are common, we may need to rethink many of our ideas about the origins of morphological diversity.
A long-standing hypothesis in adaptive radiation theory is that ecological opportunity constrains rates of phenotypic evolution, generating a burst of morphological disparity early in clade history. Empirical support for the early burst model is rare in comparative data, however. One possible reason for this lack of support is that most phylogenetic tests have focused on extant clades, neglecting information from fossil taxa. Here, I test for the expected signature of adaptive radiation using the outstanding 40-My fossil record of North American canids. Models implying time- and diversity-dependent rates of morphological evolution are strongly rejected for two ecologically important traits, body size and grinding area of the molar teeth. Instead, Ornstein–Uhlenbeck processes implying repeated, and sometimes rapid, attraction to distinct dietary adaptive peaks receive substantial support. Diversity-dependent rates of morphological evolution seem uncommon in clades, such as canids, that exhibit a pattern of replicated adaptive radiation. Instead, these clades might best be thought of as deterministic radiations in constrained Simpsonian subzones of a major adaptive zone. Support for adaptive peak models may be diagnostic of subzonal radiations. It remains to be seen whether early burst or ecological opportunity models can explain broader adaptive radiations, such as the evolution of higher taxa.
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