53 research outputs found
Cervical spine kinematics after anterior cervical discectomy with or without implantation of a mobile cervical disc prosthesis; an RCT
Background: When surgically treating cervical degenerative disc disease, the most commonly performed procedure is anterior cervical discectomy. This procedure is performed with, or without fusion promoting methods. For both options the rate of fusion is high and there is much debate whether fusion of the treated segment is a contributing factor to accelerated degeneration of adjacent motion segments. In an effort to prevent degeneration of adjacent segments (ASDeg) due to loss of mobility at the operated level, cervical disc arthroplasty (CDA) was introduced. To evaluate the effectiveness of CDA in preventing ASDeg long term studies are necessary. However, prevention of ASDeg is based on the premise that mobile disc prostheses preserve cervical spine motion in a physiological way. In this article the authors describe a short term protocol for a study that aims to investigate whether CDA reaches the intended goal: restoration or preservation of physiological cervical spine motion. To this end, a technique is used to establish the sequence of contributions of cervical motion segments to flexion/extension of the spine. Methods: 24 subjects between 18 and 55 years old, with radicular symptoms due to a herniated disc between C5 and C7, refractory to conservative therapy are randomized to simple discectomy, or CDA. These groups are preceded by a pilot group of three subjects receiving CDA. Fluoroscopic flexion-extension recordings are acquired preoperatively, and at three and 12 months postoperative. At these same time points, patient reported outcomes are collected, and a neurological examination is performed by and independent physician. Discussion: Studies investigating arthroplasty determine mobility by measuring segmental range of motion (sROM), which gives no information other than presence, and quantity, of mobility. SROM suffer from high variability. The authors therefore chose to use a method previously used in healthy controls, to describe the dynamic process of cervical spine motion in more detail. Determining cervical spine motion patterns has been reported to be more consistent than sROM. If a physiological motion pattern is absent after surgery in the CDA group, prevention of future ASDeg is less likely. Radiological outcomes will be correlated to clinical outcomes
Surgical Interventions for Cervical Radiculopathy without Myelopathy:A Systematic Review and Meta-Analysis
BACKGROUND: The effectiveness of surgical interventions for cervical degenerative disorders has been investigated in multiple systematic reviews. Differences in study population (e.g., patients with myelopathy and/or radiculopathy) were often neglected. Therefore, the objective of this study was to investigate the effectiveness of surgical interventions for patients with symptoms of cervical radiculopathy without myelopathy by conducting a systematic review and meta-analysis based on randomized controlled trials (RCTs). METHODS: A comprehensive systematic search was conducted in MEDLINE, Embase, and CENTRAL (Cochrane Central Register of Controlled Trials) to identify RCTs that investigated the effectiveness of surgical interventions using an anterior or posterior approach compared with other interventions for patients with pure cervical radiculopathy. Outcomes were success rates (Odom criteria, similar rating scales, or percentage of patients who improved), complication and reoperation rates, work status, disability (Neck Disability Index), and pain (arm and neck). The Cochrane risk-of-bias tool was used to assess the likelihood of the risk of bias. A random-effects model was used. Heterogeneity among study results (I ≥ 50% or p < 0.05) was explored by conducting subgroup analyses. Funnel plots were used to assess the likelihood of publication bias. RESULTS: A total of 21 RCTs were included, comprising 1,567 patients. For all outcomes, among all surgical techniques, only 1 pooled estimate showed a significant effect on success rate, which was in favor of anterior cervical discectomy with fusion compared with anterior cervical discectomy without an intervertebral spacer (p = 0.02; risk ratio [RR] = 0.87; 95% confidence interval [CI] = 0.77 to 0.98). Complication rates were higher when autologous bone graft from the iliac crest was used as an intervertebral spacer (p < 0.01; RR = 3.40; 95% CI = 1.56 to 7.43), related to donor-site morbidity. CONCLUSIONS: This meta-analysis demonstrated consistent results regarding clinical outcome for pure cervical radiculopathy among all studied interventions. Complication and reoperation rates were also similar, with the exception of higher complication rates in patients in whom autologous bone grafts were used. On the basis of clinical outcome and safety, there is no superior surgical intervention for pure cervical radiculopathy. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence
Computed tomography as an adjunct to ultrasound in the diagnosis of acute acalculous cholecystitis
The sonographic and computed tomographic (CT) findings were reviewed in 17 patients with acute acalculous cholecystitis (AAC) over a 6-year period from 1984 to 1989. Of the six patients in whom both ultrasound and CT were performed, CT revealed marked gallbladder (GB) wall abnormalities, including perforation, and pericholecystic fluid collections in five patients not demonstrated by sonography. Of the total group, five patients had GB wall thicknesses of ≤ 3 mm (normal) at pathologic examination, which demonstrated a spectrum of disease ranging from acute hemorrhagic/necrotizing, to gangrenous acalculous cholecystitis with perforation. Sonography was falsely negative or significantly underestimated the severity of AAC in seven of the 13 patients examined by sonography. CT because of its superior ability to assess pericholecystic inflammation may provide additional diagnostic information even after a thorough sonographic study in cases of AAC.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48138/1/261_2005_Article_BF01887331.pd
The EnMAP imaging spectroscopy mission towards operations
EnMAP (Environmental Mapping and Analysis Program) is a high-resolution imaging spectroscopy remote sensing mission that was successfully launched on April 1st, 2022. Equipped with a prism-based dual-spectrometer, EnMAP performs observations in the spectral range between 418.2nm and 2445.5nm with 224 bands and a high radiometric and spectral accuracy and stability. EnMAP products, with a ground instantaneous field-of-view of 30m×30m at a swath width of 30km, allow for the qualitative and quantitative analysis of surface variables from frequently and consistently acquired observations on a global scale. This article presents the EnMAP mission and details the activities and results of the Launch and Early Orbit and Commissioning Phases until November 1st, 2022. The mission capabilities and expected performances for the operational Routine Phase are provided for existing and future EnMAP users
Psychological profiles associated with mental, cognitive and brain health in middle-aged and older adults
Psychological characteristics are associated with varying dementia risk and protective factors. To determine whether these characteristics aggregate into psychological profiles and whether these profiles differentially relate to aging health, we conducted a cross-sectional investigation in two independent middle-aged (51.4 ± 7.0 years (mean ± s.d.); N = 750) and older adult (71.1 ± 5.9 years; N = 282) cohorts, supplemented by longitudinal analyses in the former. Using a person-centered approach, three profiles emerged in both cohorts: those with low protective characteristics (profile 1), high risk characteristics (profile 2) and well-balanced characteristics (profile 3). Profile 1 showed the worst objective cognition in older age and middle age (at follow-up), and most rapid cortical thinning. Profile 2 exhibited the worst mental health symptomology and lowest sleep quality in both older age and middle age. We identified profile-dependent divergent patterns of associations that may suggest two distinct paths for mental, cognitive and brain health, emphasizing the need for comprehensive psychological assessments in dementia prevention research to identify groups for more personalized behavior-change strategies
Dissemination of Cephalosporin Resistance Genes between Escherichia coli Strains from Farm Animals and Humans by Specific Plasmid Lineages
Third-generation cephalosporins are a class of β-lactam antibiotics that are often used for the treatment of human infections caused by Gram-negative bacteria, especially Escherichia coli. Worryingly, the incidence of human infections caused by third-generation cephalosporin-resistant E. coli is increasing worldwide. Recent studies have suggested that these E. coli strains, and their antibiotic resistance genes, can spread from food-producing animals, via the food-chain, to humans. However, these studies used traditional typing methods, which may not have provided sufficient resolution to reliably assess the relatedness of these strains. We therefore used whole-genome sequencing (WGS) to study the relatedness of cephalosporin-resistant E. coli from humans, chicken meat, poultry and pigs. One strain collection included pairs of human and poultry-associated strains that had previously been considered to be identical based on Multi-Locus Sequence Typing, plasmid typing and antibiotic resistance gene sequencing. The second collection included isolates from farmers and their pigs. WGS analysis revealed considerable heterogeneity between human and poultry-associated isolates. The most closely related pairs of strains from both sources carried 1263 Single-Nucleotide Polymorphisms (SNPs) per Mbp core genome. In contrast, epidemiologically linked strains from humans and pigs differed by only 1.8 SNPs per Mbp core genome. WGS-based plasmid reconstructions revealed three distinct plasmid lineages (IncI1- and IncK-type) that carried cephalosporin resistance genes of the Extended-Spectrum Beta-Lactamase (ESBL)- and AmpC-types. The plasmid backbones within each lineage were virtually identical and were shared by genetically unrelated human and animal isolates. Plasmid reconstructions from short-read sequencing data were validated by long-read DNA sequencing for two strains. Our findings failed to demonstrate evidence for recent clonal transmission of cephalosporin-resistant E. coli strains from poultry to humans, as has been suggested based on traditional, low-resolution typing methods. Instead, our data suggest that cephalosporin resistance genes are mainly disseminated in animals and humans via distinct plasmids
The Science Performance of JWST as Characterized in Commissioning
This paper characterizes the actual science performance of the James Webb
Space Telescope (JWST), as determined from the six month commissioning period.
We summarize the performance of the spacecraft, telescope, science instruments,
and ground system, with an emphasis on differences from pre-launch
expectations. Commissioning has made clear that JWST is fully capable of
achieving the discoveries for which it was built. Moreover, almost across the
board, the science performance of JWST is better than expected; in most cases,
JWST will go deeper faster than expected. The telescope and instrument suite
have demonstrated the sensitivity, stability, image quality, and spectral range
that are necessary to transform our understanding of the cosmos through
observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures;
https://iopscience.iop.org/article/10.1088/1538-3873/acb29
Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults
Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We
estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from
1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories.
Methods We used data from 3663 population-based studies with 222 million participants that measured height and
weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate
trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children
and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the
individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference)
and obesity (BMI >2 SD above the median).
Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in
11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed
changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and
140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of
underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and
countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior
probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse
was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of
thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a
posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%)
with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and
obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for
both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such
as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged
children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls
in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and
42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents,
the increases in double burden were driven by increases in obesity, and decreases in double burden by declining
underweight or thinness.
Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an
increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy
nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of
underweight while curbing and reversing the increase in obesit
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
The EnMAP imaging spectroscopy mission towards operations
EnMAP (Environmental Mapping and Analysis Program) is a high-resolution imaging spectroscopy remote sensing mission that was successfully launched on April 1st, 2022. Equipped with a prism-based dual-spectrometer, EnMAP performs observations in the spectral range between 418.2 nm and 2445.5 nm with 224 bands and a high radiometric and spectral accuracy and stability. EnMAP products, with a ground instantaneous field-of-view of 30 m x 30 m at a swath width of 30 km, allow for the qualitative and quantitative analysis of surface variables from frequently and consistently acquired observations on a global scale. This article presents the EnMAP mission and details the activities and results of the Launch and Early Orbit and Commissioning Phases until November 1st, 2022. The mission capabilities and expected performances for the operational Routine Phase are provided for existing and future EnMAP users
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