Purpose
New-generation wide-base tire (NG-WBT) is known for improving fuel economy and at the same time for potentially causing a greater damage to pavement. No study has been conducted to evaluate ...the net environmental saving of the combined system of pavements and NG-WBT. This study adopted a holistic approach (life cycle assessment LCA and life cycle costing LCC) to quantitatively evaluate the environmental and economic impact of using NG-WBT.
Methods
The net effect of different levels of market penetration of NG-WBT on energy consumption, global warming potential (GWP), and cost based on the fatigue cracking and rutting performance of two different asphalt concrete (AC) pavement structures was evaluated. The performance of pavements was determined based on pavement design lives; pavement surface characteristics, and pavement critical strain responses obtained from the artificial neural network (ANN) based on finite element (FE) simulations were used to calculate design lives of pavements. Based on the calculated design lives, life cycle inventory (LCI) and cost databases, and rolling resistance (RR) models previously developed by the University of Illinois at Urbana-Champaign (UIUC) were used to calculate the environmental and economic impact of the combined system.
Results and discussion
The fuel economy improvement using NG-WBT is 1.5% per axle. Scenario-based case studies were conducted. Considering 0% NG-WBT market penetration (or 100% standard dual tire assembly DTA) as a baseline, scenario 1 assumed the same fatigue and rutting potential between NG-WBT and DTA; therefore, the only difference came from fuel economy improvement of using NG-WBT. In scenario 2, pavement fatigue cracking potential determined the pavement design life; both thick and thin AC overlay sections experienced positive net environmental savings, but mixed net economic savings. In scenario 3, pavement rutting potential determined the pavement design life; the thick AC overlay section experienced positive net environmental savings, but mixed net economic savings. The thin section experienced negative net environmental and economic savings.
Conclusions
The outcomes of scenario-based case studies indicated that NG-WBT can result in significant savings in life cycle energy consumption and cost, and GWP; however, these benefits were sensitive to the method used to determine the pavement performance; especially, a small change in pavement strain can result in significant change in pavement life. In addition, the effect of fuel price/economy improvement, discount rate, and International Roughness Index (IRI) threshold values was studied in the sensitivity analyses.
Background
The 2019 European Working Group on Sarcopenia in Older People (EWGSOP2) and the Sarcopenia Definitions and Outcomes Consortium (SDOC) have recently proposed sarcopenia definitions. ...However, comparisons of the performance of these approaches in terms of thresholds employed, concordance in individuals and prediction of important health‐related outcomes such as death are limited. We addressed this in a large multinational assembly of cohort studies that included information on lean mass, muscle strength, physical performance and health outcomes.
Methods
White men from the Health Aging and Body Composition (Health ABC) Study, Osteoporotic Fractures in Men (MrOS) Study cohorts (Sweden, USA), the Hertfordshire Cohort Study (HCS) and the Sarcopenia and Physical impairment with advancing Age (SarcoPhAge) Study were analysed. Appendicular lean mass (ALM) was ascertained using DXA; muscle strength by grip dynamometry; and usual gait speed over courses of 2.4–6 m. Deaths were recorded and verified. Definitions of sarcopenia were as follows: EWGSOP2 (grip strength <27 kg and ALM index <7.0 kg/m2), SDOC (grip strength <35.5 kg and gait speed <0.8 m/s) and Modified SDOC (grip strength <35.5 kg and gait speed <1.0 m/s). Cohen's kappa statistic was used to assess agreement between original definitions (EWGSOP2 and SDOC). Presence versus absence of sarcopenia according to each definition in relation to mortality risk was examined using Cox regression with adjustment for age and weight; estimates were combined across cohorts using random‐effects meta‐analysis.
Results
Mean (SD) age of participants (n = 9170) was 74.3 (4.9) years; 5929 participants died during a mean (SD) follow‐up of 12.1 (5.5) years. The proportion with sarcopenia according to each definition was EWGSOP2 (1.1%), SDOC (1.7%) and Modified SDOC (5.3%). Agreement was weak between EWGSOP2 and SDOC (κ = 0.17). Pooled hazard ratios (95% CI) for mortality for presence versus absence of each definition were EWGSOP2 1.76 (1.42, 2.18), I2: 0.0%; SDOC 2.75 (2.28, 3.31), I2: 0.0%; and Modified SDOC 1.93 (1.54, 2.41), I2: 58.3%.
Conclusions
There was low prevalence and poor agreement among recent sarcopenia definitions in community‐dwelling cohorts of older white men. All indices of sarcopenia were associated with mortality. The strong relationship between sarcopenia and mortality, regardless of the definition, illustrates that identification of appropriate management and lifecourse intervention strategies for this condition is of paramount importance.
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Tissue engineering strategies have emerged in response to the growing prevalence of chronic musculoskeletal conditions, with many of these regenerative methods currently being ...evaluated in translational animal models. Engineered replacements for fibrous tissues such as the meniscus, annulus fibrosus, tendons, and ligaments are subjected to challenging physiologic loads, and are difficult to track in vivo using standard techniques. The diagnosis and treatment of musculoskeletal conditions depends heavily on radiographic assessment, and a number of currently available implants utilize radiopaque markers to facilitate in vivo imaging. In this study, we developed a nanofibrous scaffold in which individual fibers included radiopaque nanoparticles. Inclusion of radiopaque particles increased the tensile modulus of the scaffold and imparted radiation attenuation within the range of cortical bone. When scaffolds were seeded with bovine mesenchymal stem cells in vitro, there was no change in cell proliferation and no evidence of promiscuous conversion to an osteogenic phenotype. Scaffolds were implanted ex vivo in a model of a meniscal tear in a bovine joint and in vivo in a model of total disc replacement in the rat coccygeal spine (tail), and were visualized via fluoroscopy and microcomputed tomography. In the disc replacement model, histological analysis at 4weeks showed that the scaffold was biocompatible and supported the deposition of fibrous tissue in vivo. Nanofibrous scaffolds that include radiopaque nanoparticles provide a biocompatible template with sufficient radiopacity for in vivo visualization in both small and large animal models. This radiopacity may facilitate image-guided implantation and non-invasive long-term evaluation of scaffold location and performance.
The healing capacity of fibrous musculoskeletal tissues is limited, and injury or degeneration of these tissues compromises the standard of living of millions in the US. Tissue engineering repair strategies for the intervertebral disc, meniscus, tendon and ligament have progressed from in vitro to in vivo evaluation using a variety of animal models, and the clinical application of these technologies is imminent. The composition of most scaffold materials however does not allow for visualization by methods available to clinicians (e.g., radiography), and thus it is not possible to assess their performance in situ. In this work, we describe a radiopaque nanofibrous scaffold that can be visualized radiographically in both small and large animal models and serve as a framework for the development of an engineered fibrous tissue.
AbstractFatigue cracking due to repeated truck traffic loads is the leading cause of failure of asphalt concrete pavement in many locations. Rest periods, referring to the time intervals between ...successive trucks, may allow for partial or full recovery from fatigue damage and in turn extend pavement fatigue life. This paper delves into the characteristics of rest periods between highway truck traffic loads using traffic data from 40 weigh-in-motion (WIM) stations installed on California state highways and evaluates their effects on pavement performance using mechanistic-empirical incremental-recursive damage and cracking simulation (CalME software). Toward this purpose, truck traffic data were extracted from these WIM stations at selected periods throughout the year 2015 to calculate rest periods. The probability distribution of rest periods and quantiles of cumulative rest periods were calculated, respectively. Regression and statistical analysis for 0.5 quantiles (median) of cumulative rest periods were also performed for different spectra groups and seasons. It was found that rest periods are strongly correlated with the truck traffic volume regardless of the WIM station location and seasons of the year. The actual rest periods based on the nonuniform truck traffic measured from the WIM data were found to be slightly shorter than the corresponding theoretical average rest periods for uniform traffic (ARP-UT) currently assumed in CalME, likely due to truck-following. This theoretical value assumes an equal time interval between trucks all the time. After comparing pavement performance with and without rest periods, it was found that rest periods have a significant influence (30% in difference) on pavement cracking performance in the modeling. Based on this preliminary analysis, the difference in pavement performance caused by the difference between the actual rest periods and ARP-UT is minimal. It is therefore recommended to continue to use ARP-UT to account for the effect of rest periods in pavement design.
Aim
To assess the prognostic capabilities of various diagnostic modalities for childhood brachial plexus injuries (BPIs) and brachial plexus birth injury (BPBI) and postneonatal BPI.
Method
In this ...single‐center retrospective cross‐sectional study, we examined children with BPIs diagnosed or confirmed by electrodiagnostic studies between 2013 and 2020, and compared the prognostic value of various components of the electrophysiologic findings, magnetic resonance imaging (MRI) data, and the Active Movement Scale (AMS). We developed scoring systems for electrodiagnostic studies and MRI findings, including various components of nerve conduction studies and electromyography (EMG) for electrodiagnostic studies.
Results
We identified 21 children (10 females and 11 males) aged 8 days to 21 years (mean 8y 6.95mo) who had a total of 30 electrodiagnostic studies, 14 brachial plexus MRI studies, and 10 surgical procedures. Among the diagnostic modalities assessed, brachial plexus MRI scores, EMG denervation scores, and mean total EMG scores were the most valuable in predicting surgical versus non‐surgical outcomes. Correspondingly, a combined MRI/mean total EMG score provided prognostic value.
Interpretation
Brachial plexus MRI scores and specific electrodiagnostic scores provide the most accurate prognostic information for children with BPI. Our grading scales can assist a multidisciplinary team in quantifying results of these studies and determining prognosis in this setting.
What this paper adds
A new scoring system to quantify results of electrodiagnostic and magnetic resonance imaging (MRI) studies is presented.
Severity of denervation has good prognostic value for childhood brachial plexus injuries (BPIs).
Composite electromyography scores have good prognostic value for childhood BPIs.
Brachial plexus MRI has good prognostic value for childhood BPIs.
What this paper adds
A new scoring system to quantify results of electrodiagnostic and magnetic resonance imaging (MRI) studies is presented.
Severity of denervation has good prognostic value for childhood brachial plexus injuries (BPIs).
Composite electromyography scores have good prognostic value for childhood BPIs.
Brachial plexus MRI has good prognostic value for childhood BPIs.
Childhood brachial plexus injury can have significant consequences and it is important to determine prognosis so that key decisions such as whether and when to consider surgical options can be made in an informed manner. This study examines the comparative utility of clinical, electrophysiologic, and imaging measures for determining prognosis in this setting.
This original article is commented on by Bahm on pages 1186–1187 of this issue.
To determine whether a bandage contact lens (BCL) improves patient comfort in the postoperative period in patients undergoing ptosis repair using the Fasanella-Servat technique, compared with no BCL.
...In this prospective, randomized, double-masked, comparison study, all patients had bilateral Fasanella-Servat surgery. A total of 30 patients were randomized to receive a BCL in one eye and no BCL in the other eye. Patient discomfort was measured as the primary outcome using the Eye Sensation Scale. Blurred vision was measured as a secondary outcome using selected questions from the Ocular Surface Disease Index. The surgeries were performed by 2 surgeons (J.T.H and R.S.A). Outcomes were measured one week following the procedure.
Patients reported significantly less discomfort in the eye receiving a BCL, with only 13.3% ranking discomfort as "moderate" or "severe," compared with the eye not receiving BCL, where 63.3% of patients rated discomfort as "moderate" or "severe" (p < 0.001). There was no significant difference in patient-reported blurred vision between the 2 groups (p = 0.520).
The use of a bandage contact lens after Fasanella-Servat procedure for ptosis repair is recommended as it improves patient comfort. In addition, it has no detrimental effect on patient-reported blurring of vision.
Helicobacter pylori genomes encode over 60 predicted outer membrane proteins (OMPs). Several OMPs in the Hop family act as adhesins, but the functions of most Hop proteins are unknown. To identify
...mutant strains exhibiting differential fitness
compared to
, we used a genetic barcoding method that allowed us to track changes in the proportional abundance of H. pylori strains within a mixed population. We generated a library of
mutant strains, each containing a unique nucleotide barcode, as well as a library of control strains, each containing a nucleotide barcode in an intergenic region predicted to be a neutral locus unrelated to bacterial fitness. We orogastrically inoculated each of the libraries into mice and analyzed compositional changes in the populations over time
compared to changes detected in the populations during library passage
. The control library proliferated as a relatively stable community
, but there was a reduction in the population diversity of this library
and marked variation in the dominant strains recovered from individual animals, consistent with the existence of a nonselective bottleneck
. We did not identify any OMP mutants exhibiting fitness defects exclusively
without corresponding fitness defects
. Conversely, a
mutant exhibited a strong fitness advantage
but not
. These findings, when taken together with results of other studies, suggest that production of BabA may have differential effects on H. pylori fitness depending on the environmental conditions.
Purpose
To assess the within‐treatment efficacy of hot compresses (HC), HC plus tobramycin (Tobrex) and HC plus tobramycin/dexamethasone (Tobradex) for chalazia treatment.
Methods
Design: ...Multicentre, randomized clinical trial (ClinicalTrials.gov identifier, NCT01230593). Setting: Two clinical sites in New York and two clinical sites in Ontario. Study Population: A total of 149 patients with one or more chalazia on separate eyelids randomly assigned to receive HC (n = 50), HC plus tobramycin (n = 50) or HC plus tobramycin/dexamethasone (n = 49). Intervention: 4–6 weeks of assigned treatment. Patients were measured for chalazion horizontal width and surveyed for pain and treatment satisfaction levels. Main outcome measures: Primary outcome was complete resolution (100% size reduction). Secondary outcomes were size change in millimetres and patient reported pre‐ and post‐treatment pain and satisfaction levels.
Results
In the intention‐to‐treat (ITT) population, complete resolution occurred in 36 (18%) lesions total, 13 (21%) treated with HC, 12 (16%) with HC plus tobramycin and 11 (18%) with HC plus tobramycin/dexamethasone, with no significant difference between them (p = .78). Individually by paired t‐test, there were statistically significant post‐treatment mean size differences: HC 1.20 mm (p < 0.001), HC plus tobramycin 1.69 mm (p < .001) and HC plus tobramycin/dexamethasone 1.54 mm (p < 0.001), but no significant difference between them (p = .61). Lesions that completely resolved had a statistically significant lower pretreatment duration (1.5 months) compared to lesions that did not completely resolve (2.2 months) (p = .04).
Conclusion
Hot compresses (HC) alone or in combination with tobramycin or tobramycin/dexamethasone drops and ointment are all effective first‐line treatment options for chalazia. However, physicians may consider moving directly to the use of more invasive therapies, such as incision and curettage or steroid injections, for chalazia that have been present for more than 2 months, as older lesions are less likely to resolve with conservative therapies alone.
The
Cag type IV secretion system (T4SS) translocates the effector protein CagA and nonprotein bacterial constituents into host cells. In this study, we infected Mongolian gerbils with an
strain in ...which expression of the
operon (required for Cag T4SS activity) is controlled by a TetR/
system. Transcript levels of
were significantly higher in gastric tissue from
-infected animals receiving doxycycline-containing chow (to derepress Cag T4SS activity) than in tissue from infected control animals receiving drug-free chow. At 3 months postinfection, infected animals receiving doxycycline had significantly increased gastric inflammation compared to infected control animals. Dysplasia (a premalignant histologic lesion) and/or invasive gastric adenocarcinoma were detected only in infected gerbils receiving doxycycline, not in infected control animals. We then conducted experiments in which Cag T4SS activity was derepressed during defined stages of infection. Continuous Cag T4SS activity throughout a 3-month time period resulted in higher rates of dysplasia and/or gastric cancer than observed when Cag T4SS activity was limited to early or late stages of infection. Cag T4SS activity for the initial 6 weeks of infection was sufficient for the development of gastric inflammation at the 3-month time point, with gastric cancer detected in a small proportion of animals. These experimental results, together with previous studies of
mutant strains, provide strong evidence that Cag T4SS activity contributes to gastric carcinogenesis and help to define the stages of
infection during which Cag T4SS activity causes gastric alterations relevant for cancer pathogenesis.
The "hit-and-run model" of carcinogenesis proposes that an infectious agent triggers carcinogenesis during initial stages of infection and that the ongoing presence of the infectious agent is not required for development of cancer.
infection and actions of CagA (an effector protein designated a bacterial oncoprotein, secreted by the Cag T4SS) are proposed to constitute a paradigm for hit-and-run carcinogenesis. In this study, we report the development of methods for controlling
Cag T4SS activity
and demonstrate that Cag T4SS activity contributes to gastric carcinogenesis. We also show that Cag T4SS activity during an early stage of infection is sufficient to initiate a cascade of cellular alterations leading to gastric inflammation and gastric cancer at later time points.
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