458 research outputs found
a new Pc-C boundary section
The widespread, terminal Ediacaran Dengying Formation (~ 551–~ 542 Ma) of
South China hosts one of the most prominent negative carbonate carbon isotope
excursions in Earth's history and thus bears on the correlation of the
Precambrian–Cambrian boundary worldwide. The dominantly carbonate strata of
the Dengying Formation are largely studied for their unique preservation of
its terminal Ediacaran fauna but their geochemical context is poorly known.
This study presents the first high-resolution stable isotope record (δ13C,
δ18O) of calcareous siliciclastic shallow-water deposits of the Gaojiashan
section (Shaanxi Province). The section includes (in ascending order) the
Algal Dolomite Member, the Gaojiashan Member and the Beiwan Member of the
Dengying Formation. Our data record a major δ13Ccarb negative excursion to −6
‰ in the uppermost Gaojiashan Member which is comparable in shape and
magnitude to the global Precambrian–Cambrian boundary negative δ13C excursion.
Our data set is consistent with a "shallow-water anoxia" scenario which is
thought to contribute to the "Cambrian explosion". The stratigraphic
occurrence of Cloudina and a large negative δ13C excursion suggest that the
Precambrian–Cambrian boundary is located near the top of the Gaojiashan Member
and, consequently, that overlying carbonates and dolomites of the Beiwan
Member are of earliest Cambrian age. Thus the Gaojiashan section may represent
a new shallow-water section spanning the Precambrian–Cambrian boundary.
Although bio- and chemostratigraphic data support this novel interpretation,
we cannot exclude the possibility that the key excursions may represent a
local perturbation indicating a restricted-basin environment
Drug Delivery Micropump with Built-In Monitoring
AbstractWe report on the fabrication of the first MEMS micropump including an integrated pressure sensor. The signal of this sensor allows direct insight into the pump's operating dynamics and enables real-time self-monitoring. We demonstrate the changes in the sensor signal under different pumping conditions, including the presence of air in the pumping chamber and a downstream occlusions. Deviations from normal operating conditions create clear and characteristic deviations from the normal signal. These deviations will be exploited to detect extraordinary or faulty pumping conditions during use
Anterior implant restorations with a convex emergence profile increase the frequency of recession: 12-month results of a randomized controlled clinical trial
AIM
To test whether the emergence profile (CONVEX or CONCAVE) of implant-supported crowns influences the mucosal margin stability up to 12 months after insertion of the final restoration.
MATERIALS AND METHODS
Forty-seven patients with a single implant in the anterior region were randomly allocated to one of three groups: (1) CONVEX (n = 15), implant provisional and an implant-supported crown both with a convex profile; (2) CONCAVE (n = 16), implant provisional and an implant-supported crown both with a concave profile; (3) CONTROL (n = 16), no provisional (healing abutment only) and an implant-supported crown. All patients were recalled at baseline, 6, and 12 months. The stability of mucosal margin along with clinical, aesthetic, and profilometric outcomes as well as time and costs were evaluated. To predict the presence of recession, multivariable logistic regressions were performed and linear models using generalized estimation equations were conducted for the different outcomes.
RESULTS
Forty-four patients were available at 12 months post-loading. The frequency of mucosal recession amounted to 64.3% in group CONVEX, 14.3% in group CONCAVE, and 31.4% in group CONTROL. Regression models revealed that a CONVEX profile was significantly associated with the presence of recessions (odds ratio: 12.6, 95% confidence interval: 1.82-88.48, p = .01) compared with the CONCAVE profile. Pink aesthetic scores amounted to 5.9 in group CONVEX, 6.2 in group CONCAVE, and 5.4 in group CONTROL, with no significant differences between the groups (p = .735). Groups CONVEX and CONCAVE increased the appointments and costs compared with the CONTROL group.
CONCLUSIONS
The use of implant-supported provisionals with a CONCAVE emergence profile results in a greater stability of the mucosal margin compared with a CONVEX profile up to 12 months of loading. This is accompanied, however, by increased time and costs compared with the absence of a provisional and may not necessarily enhance the aesthetic outcomes.
TRIAL REGISTRATION
German Clinical Trials Register; DRKS00009420
Past and current practice of patient-reported outcome measurement in randomized cancer clinical trials: a systematic review
Objectives
In our systematic review, we assessed past and current practice of patient-reported outcome (PRO) measurement in cancer randomized, controlled trials (RCTs).
Methods
We included RCTs with PRO endpoints evaluating conventional medical treatments, conducted in patients with the most prevalent solid tumor types (breast, lung, colorectal, prostate, bladder, and gynecological cancers) and either published in 2004 to 2018 or registered on clinicaltrials.gov and initiated in 2014 to 2019. Frequency of use of individual PRO measures was assessed overall, over time, and by cancer site.
Results
Screening of 42 095 database records and 3425 registered trials identified 480 published and 537 registered trials meeting inclusion criteria. Among published trials, the European Organisation for Research and Treatment of Cancer (EORTC) measures were used most often (54.8% of trials), followed by the Functional Assessment of Chronic Illness Therapy (FACIT) measures (35.8%), the EQ-5D (10.2%), the SF-36 (7.3%), and the MD Anderson Symptom Inventory (MDASI; 2.5%). Among registered trials, the EORTC measures were used in 66.1% of the trials, followed by the FACIT measures (25.9%), the EQ-5D (23.1%), the SF-36 (4.8%), the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE; 2.2%), the Patient-Reported Outcomes Measurement Information System (PROMIS) measures (1.7%), and the MDASI measures (1.1%).
Conclusion
The PRO measures most frequently used in RCTs identified in our review differ substantially in terms of content and domains, reflecting the ongoing debate among the scientific community, healthcare providers, and regulators on the type of PRO to be measured. Current findings may contribute to better informing the development of an internationally agreed core outcome set for future cancer trials
The ALPS project release 1.3: open source software for strongly correlated systems
We present release 1.3 of the ALPS (Algorithms and Libraries for Physics
Simulations) project, an international open source software project to develop
libraries and application programs for the simulation of strongly correlated
quantum lattice models such as quantum magnets, lattice bosons, and strongly
correlated fermion systems. Development is centered on common XML and binary
data formats, on libraries to simplify and speed up code development, and on
full-featured simulation programs. The programs enable non-experts to start
carrying out numerical simulations by providing basic implementations of the
important algorithms for quantum lattice models: classical and quantum Monte
Carlo (QMC) using non-local updates, extended ensemble simulations, exact and
full diagonalization (ED), as well as the density matrix renormalization group
(DMRG). Changes in the new release include a DMRG program for interacting
models, support for translation symmetries in the diagonalization programs, the
ability to define custom measurement operators, and support for inhomogeneous
systems, such as lattice models with traps. The software is available from our
web server at http://alps.comp-phys.org/
Hypertonicity-induced cation channels rescue cells from staurosporine-elicited apoptosis
Cell shrinkage is one of the earliest events during apoptosis. Cell shrinkage also occurs upon hypertonic stress, and previous work has shown that hypertonicity-induced cation channels (HICCs) underlie a highly efficient mechanism of recovery from cell shrinkage, called the regulatory volume increase (RVI), in many cell types. Here, the effects of HICC activation on staurosporine-induced apoptotic volume decrease (AVD) and apoptosis were studied in HeLa cells by means of electronic cell sizing and whole-cell patch-clamp recording. It was found that hypertonic stress reduces staurosporine-induced AVD and cell death (associated with caspase-3/7 activation and DNA fragmentation), and that this effect was actually due to activation of the HICC. On the other hand, staurosporine was found to significantly reduce osmotic HICC activation. It is concluded that AVD and RVI reflect two fundamentally distinct functional modes in terms of the activity and role of the HICC, in a shrunken cell. Our results also demonstrate, for the first time, the ability of the HICC to rescue cells from the process of programmed cell death
Has VZV epidemiology changed in Italy? Results of a seroprevalence study
The aim of the study was to evaluate if and how varicella prevalence has changed in Italy. In particular a seroprevalence study was performed, comparing it to similar surveys conducted in pre-immunization era. During 2013–2014, sera obtained from blood samples taken for diagnostic purposes or routine investigations were collected in collaboration with at least one laboratory/center for each region, following the approval of the Ethics Committee. Data were stratified by sex and age. All samples were processed in a national reference laboratory by an immunoassay with high sensitivity and specificity. Statutory notifications, national hospital discharge database and mortality data related to VZV infection were analyzed as well. A total of 3707 sera were collected and tested. In the studied period both incidence and hospitalization rates decreased and about 5 deaths per year have been registered. The seroprevalence decreased in the first year of life in subjects passively protected by their mother, followed by an increase in the following age classes. The overall antibody prevalence was 84%. The comparison with surveys conducted with the same methodology in 1996–1997 and 2003–2004 showed significant differences in age groups 1–19 y. The study confirms that in Italy VZV infection typically occurs in children. The impact of varicella on Italian population is changing. The comparison between studies performed in different periods shows a significant increase of seropositivity in age class 1–4 years, expression of vaccine interventions already adopted in some regions
Repressor element 1-silencing transcription factor drives the development of chronic pain states
Chronic pain is an unmet clinical problem with vast individual, societal and economic impact. Pathologic activity of the peripheral somatosensory afferents is one of the major drivers of chronic pain. This overexcitable state of somatosensory neurons is, in part, produced by the dysregulation of genes controlling neuronal excitability. Despite intense research, a unifying theory behind neuropathic remodelling is lacking. Here we show that transcriptional suppressor, repressor element 1-silencing transcription factor (REST, NRSF), is necessary and sufficient for the development of hyperalgesic state following chronic nerve injury or inflammation. Viral overexpression of REST in mouse DRG induced prominent mechanical and thermal hyperalgesia in vivo. Sensory neuron specific, inducible Rest knock-out prevented the development of such hyperalgesic state in three different chronic pain models. Genetic deletion of Rest reverted injury-induced hyperalgesia. Moreover, viral overexpression of REST in the same neurons in which its gene has been genetically deleted restored neuropathic hyperalgesia. Finally, sensory neuron specific Rest knockout prevented injury-induced downregulation of REST target genes in DRG neurons. This work identified REST as a major regulator of peripheral somatosensory neuron remodelling leading to chronic pain. The findings might help to develop a novel therapeutic approaches to combat chronic pain.This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Alteration of Forest Structure Modifies the Distribution of Scale Insect, Stigmacoccus garmilleri, in Mexican Tropical Montane Cloud Forests
Stigmacoccus garmilleri Foldi (Hemiptera: Margarodidae) is an ecologically important honeydew-producing scale insect associated with oak trees (Quercus spp.) in highland forests of Veracruz, Mexico. The honeydew exudates of S. garmilleri serve as a significant nutrient source to many species of birds, insects, and sooty molds. Oak trees found in the forest interior, forest edge, and those scattered in pasture areas support scale insect colonies, though the pattern of insect infestations on trees within these varying landscape types has not been elucidated. This study aims to describe the distribution of scale insect infestation and any distinctions in honeydew production based on tree location. Scale insect density, honeydew volume, and sugar concentration were surveyed throughout a continuous landscape that included both patches of forest and scattered pasture trees. In addition, the anal filament through which the honeydew drop is secreted was also measured and was experimentally removed to test and measure regrowth. Scale insect densities on tree trunks were greatest on pasture trees, while intermediate densities were found on trees at the forest edge, and low densities on interior forest trees, suggesting that trees in disturbed areas are more susceptible to scale insect infestation. Trees with small diameters at breast height had significantly higher insect densities than trees with medium to large diameters. Trunk aspect (North, South, East, and West) was not a significant determinant of scale insect density. In forested areas higher densities of scale insects were found at three meters height in comparison to lower heights. Sugar concentrations and drop volumes of honeydew in forest and pasture areas were not significantly different. However, scale-insect anal tubes/filaments were significantly longer in pasture than they were in forests. Sugar concentrations of honeydew appeared to be positively correlated with temperature and negatively correlated with relative humidity. Experiments indicated that anal filaments could grow approximately 4 mm every 24 hours, and average tube growth was significantly faster in pasture than in forest, suggesting that there may be a physiological effect on the insect due to landscape disturbance. The results obtained in this study describe the increases in scale insect infestation of trees with forest disturbance. The effect of these increased scale insect densities on the host tree physiology is still to be resolved
Publisher Correction: Coupling of ocean redox and animal evolution during the Ediacaran-Cambrian transition
Correction to: Nature Communications https://doi.org/10.1038/s41467-018-04980-5; published online: 03 July 2018
The original version of this Article incorrectly gave the second address in the list of affiliations as “State Key Laboratory of Palaeobiology and Stratigraphy & Center for Excellence in Life and Paleoenvironment, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 210008 Nanjing, China”, instead of the correct ‘State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China”. This has been corrected in both the PDF and HTML versions of the Article
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